JP2000119619A - Acrylic hot-melt adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition which has a high adhesiveness and heat resistance and allows little reduction or change in the adhesive strength with time, and a high solid solvent type adhesive which has a high adhesiveness and heat resistance and copes with environmental issues, energy conservation and line speed-up. SOLUTION: This adhesive composition contains a polyvalent mercaptan part and a thermoplastic addition polymer having a first polymer part and a second polymer part which radiate from the polyvalent mercaptan part. The first polymer part comprises a high-glass transition point type polymer having a glass transition point of 273 K or higher, and the second polymer part comprises a low-glass transition point type polymer having a glass transition point of lower than 273 K. The adhesive composition may be a high solid solvent type adhesive which further contains an organic solvent wherein a thermoplastic addition polymer is dissolved and/or dispersed, has a non-volatile component concentration of from 60 to 80 wt.% and has a viscosity at 25 deg.C of 20,000 cps or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure-sensitive adhesive composition.

[0002]

2. Description of the Related Art There are various types of pressure-sensitive adhesives, such as hot-melt pressure-sensitive adhesives, solvent-type pressure-sensitive adhesives, and emulsion-type pressure-sensitive adhesives. Since the hot melt adhesive contains no or almost no organic solvent or aqueous medium, it is excellent in working environment, air pollution, danger of fire, no drying step, energy saving and the like. Solvent-based pressure-sensitive adhesives have better heat resistance and application workability than hot-melt pressure-sensitive adhesives, and have better water resistance than emulsion-type pressure-sensitive adhesives, so there is no substitute for water-resistant adhesives . However, a so-called high solid solvent-type pressure-sensitive adhesive, which reduces the amount of solvent used for environmental problems, energy saving, and speeding up the line, is required.

[0003] The pressure-sensitive adhesive basically exhibits tackiness by an acrylic polymer having a low glass transition point, and exhibits heat resistance by crosslinking, but requires hot-melt coating property. Hot-melt pressure-sensitive adhesives are inferior in heat resistance because of difficulty in introducing a crosslinked structure. Conventionally, many proposals have been made to improve the heat resistance of hot melt pressure-sensitive adhesives.

JP-A-56-161484 discloses a hot melt resin composition containing a graft polymer or a block polymer obtained by polymerizing a monomer that gives another polymer in the presence of a polymer. ing. JP-A-56-59882 describes a hot melt resin composition containing a graft polymer obtained by mutually reacting the functional groups of two types of polymers having functional groups and having different compositions. .

JP-A-58-53969 describes a hot melt resin composition containing a polymer having a branched structure, which is obtained by polymerizing a monomer which gives another polymer in the presence of a polymer. . JP-A-58-61160
Japanese Patent Application Laid-Open Publication No. H11-146,1992 discloses a hot melt resin composition containing a mixture obtained by heat-polymerizing two kinds of polymers having different compositions in the presence of a peroxide.

JP-A-2-103277 and JP-A-5-31595 describe hot-melt resin compositions containing a star-shaped polymer having the same block polymer portion extending from the same center. I have. JP-A-2-167
No. 380 describes a hot melt resin composition containing a graft polymer obtained by copolymerizing a macromonomer and a low molecular weight monomer.

[0007] The above-mentioned improved example has relatively good hot melt workability, but still has poor heat resistance. In addition, all of these polymers are generally expensive polymers. In particular, among block polymers, SIS (styrene-isoprene-styrene copolymer) has been used more widely than any of these polymers because of its relatively excellent heat resistance and low price, In addition, there is a problem that the thermal stability during melt coating is low.

Next, the following examples can be given as examples of improvements made on a hot melt resin composition containing a metal crosslinked product. JP-A-50-139135 and JP-A-51-19035 describe hot-melt resin compositions in which an acrylic polymer having a carboxyl group is crosslinked with metal ions.

JP-A-56-14573 discloses a hot melt resin composition containing a crosslinked polymer obtained by adding maleic anhydride to low molecular weight polyisoprene and crosslinking with metal ions, and a tackifier. ing. JP-A-58-1
Japanese Patent No. 25774 describes a hot melt resin composition containing an acrylic polymer having a carboxyl group, a metal salt, and o-methoxyaryl acid.

JP-A-5-202345 describes a hot melt resin composition comprising an acrylic polymer having a carboxyl group neutralized by a polyvalent metal. The hot melt resin composition containing such a metal crosslinked product has better heat resistance than those containing a block copolymer and a graft copolymer, but has a problem that thermal stability at the time of melt coating is low.

On the other hand, a hot-melt resin composition in which a moisture-curable functional group such as an isocyanate group is introduced has been proposed in order to perform a crosslinking reaction after the hot-melt operation and to improve heat resistance. This hot melt resin composition requires a long time to exhibit heat resistance, and there is a concern that the performance may change over time.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive adhesive composition which is excellent in tackiness and heat resistance, and which hardly causes a decrease or a change in tackiness over time. Another object of the present invention is to provide a high-solid solvent-type pressure-sensitive adhesive which has excellent tackiness and heat resistance, and can cope with environmental problems, energy saving, and speed-up of a line.

Still another object of the present invention is to maintain hot melt pressure-sensitive adhesive features such as low capital investment and low energy consumption while maintaining hot melt workability, heat resistance, weather resistance, and the like.
An object of the present invention is to provide a pressure-sensitive adhesive composition that satisfies all of thermal stability and adhesiveness during melt coating.

[0014]

According to a first aspect of the present invention, there is provided a pressure-sensitive adhesive composition comprising a polyvalent mercaptan portion, a first polymer portion and a second polymer portion extending radially from the polyvalent mercaptan portion. And a thermoplastic addition polymer having a united portion. The first polymer portion is composed of a high glass transition point type polymer having a glass transition point of 273K or more. The second polymer portion comprises a low glass transition type polymer having a glass transition point of less than 273K.

According to a second aspect, the pressure-sensitive adhesive composition of the present invention comprises a thermoplastic addition polymer produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. Including. The preparing step is a step of preparing a first mixture containing a polyvalent mercaptan and a first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having a glass transition point of 273 K or more. is there. In the first polymerization step, the first α, β- is formed starting from the mercapto group of the polyvalent mercaptan.
This is a step of obtaining a reaction mixture by performing radical polymerization of an unsaturated monomer. The adding step is a step of adding a second α, β-unsaturated monomer to the reaction mixture to obtain a second mixture capable of producing a low glass transition point polymer having a glass transition point of less than 273K. The second polymerization step is a step of performing radical polymerization of a monomer contained in the second mixture.

According to a third aspect, the pressure-sensitive adhesive composition of the present invention comprises, in the pressure-sensitive adhesive composition of the first or second aspect, an organic solvent obtained by dissolving and / or dispersing a thermoplastic addition polymer. Further included. In the pressure-sensitive adhesive composition of the third embodiment, the nonvolatile content is 60 to 80% by weight, and the viscosity at 25 ° C. is 20,000 cps or less. According to a fourth aspect, the pressure-sensitive adhesive composition of the present invention comprises a first polymer portion composed of a high glass transition point type polymer having a glass transition point of 273K or more and a low glass having a glass transition point of less than 273K. A thermoplastic addition polymer having a second polymer portion composed of a transition point type polymer and an organic solvent in which the thermoplastic addition polymer is dissolved and / or dispersed. In the pressure-sensitive adhesive composition according to the fourth aspect, the nonvolatile content is 60 to 80% by weight, and the viscosity at 25 ° C. is 20,000 cps or less.

According to a fifth aspect of the pressure-sensitive adhesive composition of the present invention, the first polymer portion comprises a high glass transition point type acrylic polymer portion having a glass transition point of 80 ° C. or higher, The 2 polymer portion is made of a low glass transition type acrylic polymer having a glass transition point of -50 to -25 ° C, and the weight ratio of the first polymer portion to the second polymer portion is 2
0:80 to 35:65, and the thermoplastic addition polymer is 3
It is the same as the pressure-sensitive adhesive composition of the first embodiment except that it is an acrylic hot-melt pressure-sensitive adhesive having a number average molecular weight of 0000 to 60,000.

According to the sixth aspect of the pressure-sensitive adhesive composition of the present invention, the first polymer portion has a methyl methacrylate unit of 90 to 90%.
100% by weight and 0 to 10% by weight of other polymerizable monomer units, and the second polymer portion is 0 to 10% by weight of methyl methacrylate unit, 80 to 100% by weight of butyl acrylate unit and other polymerizable units. It is the same as the pressure-sensitive adhesive composition of the fifth embodiment except that it comprises 0 to 10% by weight of a monomer unit.

According to the seventh aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that the polyvalent mercaptan moiety is a residue of a 4- to 6-valent mercaptan according to the fifth or sixth aspect. Same as the pressure-sensitive adhesive composition. According to the eighth aspect, in the pressure-sensitive adhesive composition of the present invention, the first polymer portion has 2,000.
No. 5 except that it has a number average molecular weight of ~ 6,000.
This is the same as the pressure-sensitive adhesive composition according to any one of the embodiments to the seventh embodiment.

According to a ninth aspect, the pressure-sensitive adhesive composition of the present invention comprises a thermoplastic addition polymer produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. Acrylic hot melt adhesive. The preparatory step comprises a first α, β capable of producing a polyvalent mercaptan and a high glass transition point type polymer having a glass transition point of 80 ° C. or higher.
-Preparing a first mixture containing an unsaturated monomer. The first polymerization step is a step of obtaining a reaction mixture by performing radical polymerization of the first mixture while leaving the unreacted mercapto group at 15 to 85 mol% with the mercapto group of the polyvalent mercaptan as a starting point. The adding step includes the second α,
β-unsaturated monomer is added to the reaction mixture to give -50 to -25
This is a step of obtaining a second mixture capable of producing a low glass transition point type polymer having a glass transition point of ° C. The second polymerization step is a step of radically polymerizing the second mixture such that the unreacted mercapto group is reduced to 2 mol% or less starting from the unreacted mercapto group.

According to the tenth aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that the first α, β-unsaturated monomer contains 90 to 100% by weight of methyl methacrylate and 0% of another polymerizable monomer. ~ 1
0 to 10% by weight of the α, β-unsaturated monomer in the second mixture is 0 to 10% by weight of methyl methacrylate, 80 to 100% by weight of butyl acrylate and 0 to 100% by weight of another polymerizable monomer.
It is the same as the pressure-sensitive adhesive composition of the ninth embodiment except that it comprises 10 to 10% by weight.

According to the eleventh aspect, the pressure-sensitive adhesive composition of the present invention is the same as the pressure-sensitive adhesive composition of the ninth or tenth aspect except that the polyvalent mercaptan is a 4- to hexavalent mercaptan. It is. The pressure-sensitive adhesive composition of the present invention, according to the twelfth aspect, except that the high glass transition point type acrylic polymer obtained in the first polymerization step has a number average molecular weight of 2,000 to 6,000. And the ninth to eleventh embodiments.

[0023]

According to the first aspect of the present invention, there is provided a pressure-sensitive adhesive composition comprising a polyvalent mercaptan portion and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion. A low glass transition type comprising a plastic addition polymer, wherein the first polymer portion comprises a high glass transition point type polymer having a glass transition point of 273K or more, and the second polymer portion comprises a glass transition point of less than 273K. Consists of a polymer.

According to the second aspect, the pressure-sensitive adhesive composition of the present invention comprises a thermoplastic addition polymer produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. Including. The preparing step is a step of preparing a first mixture containing a polyvalent mercaptan and a first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having a glass transition point of 273 K or more. is there. In the first polymerization step, the first α, β- is formed starting from the mercapto group of the polyvalent mercaptan.
This is a step of obtaining a reaction mixture by performing radical polymerization of an unsaturated monomer. By this radical polymerization, a polymer in which the first polymer portion composed of the high glass transition point type polymer radially extends from the polyvalent mercaptan portion is generated. The addition process is
A second α, β-unsaturated monomer is added to the reaction
This is a step of obtaining a second mixture capable of producing a low glass transition point type polymer having a glass transition point of less than 3K. The second polymerization step is a step of performing radical polymerization of a monomer contained in the second mixture. By this radical polymerization, a thermoplastic addition polymer in which a second polymer portion composed of a low glass transition point type polymer radially extends from the polyvalent mercaptan portion of the polymer generated in the first polymerization step is generated.

For this reason, the thermoplastic addition polymer has a branched structure (star-shaped block structure) in which a plurality of polymer portions radially extend from the polyvalent mercaptan portion, and effectively separates phases. Since the first polymer portion composed of the high glass transition point type polymer forms a discontinuous phase and has a pseudo-crosslinked structure, it has higher cohesive strength and superior heat resistance as compared with conventional general adhesives. The higher the glass transition point of the first polymer portion, the more the heat-resistant adhesive composition becomes. In addition, the second polymer portion composed of the low glass transition point type polymer forms a continuous phase and exhibits adhesiveness. The lower the glass transition point of the second polymer portion, the greater the effect of increasing the tackiness. The development of adhesiveness is based on the same mechanism as that of a conventional general adhesive. However, in order to obtain heat resistance, a general adhesive needs to be crosslinked, whereas the adhesive composition of the present invention does not require crosslinking. Crosslinking causes a decrease in adhesive strength or a change with time depending on the crosslinking conditions, and thus may impair the reliability of the adhesive or the adhesive product. The pressure-sensitive adhesive composition of the present invention is superior in reliability to those conventional general pressure-sensitive adhesives. Further, those using isocyanate cross-linking require curing for about one week and thus have low production efficiency, but the pressure-sensitive adhesive composition of the present invention does not need to do so. However, it is possible to crosslink and use the pressure-sensitive adhesive composition of the present invention.

According to a third aspect, the pressure-sensitive adhesive composition of the present invention comprises, in the pressure-sensitive adhesive composition of the first or second aspect, an organic solvent obtained by dissolving and / or dispersing a thermoplastic addition polymer. Further included. In the pressure-sensitive adhesive composition of the third embodiment, the nonvolatile content is 60 to 80% by weight, and the viscosity at 25 ° C. is 20,000 cps or less. For this reason, the pressure-sensitive adhesive composition of the third embodiment is a high-solid solvent-type pressure-sensitive adhesive and has excellent mechanical coatability. When the conventional solvent-based pressure-sensitive adhesive is made into a high solid, the viscosity becomes extremely high, so it is necessary to reduce the molecular weight, and it is necessary to include a large amount of a curing agent in order to have heat resistance. This results in reduced tack or reduced appearance. Since the pressure-sensitive adhesive composition of the present invention has a high cohesive force by utilizing the phase separation structure as described above, the pressure-sensitive adhesive composition contains the same amount or almost the same amount of a curing agent as usual, and thus has heat resistance (for example, 80 ° C. holding power). ) Is expressed.
Therefore, high solidification can be achieved without deteriorating the adhesive properties.

According to a fourth aspect, the pressure-sensitive adhesive composition of the present invention comprises a first polymer portion comprising a high glass transition point type polymer having a glass transition point of 273K or more and a glass transition point of less than 273K. And a second polymer portion comprising a low glass transition point type polymer.
This thermoplastic addition polymer has a structure (graft structure) in which a first polymer portion and a second polymer portion are branched, and undergoes phase separation. For this reason, the same operation and effect as those of the pressure-sensitive adhesive composition of the first and second aspects are exhibited. The pressure-sensitive adhesive composition according to the fourth aspect further includes an organic solvent in which a thermoplastic addition polymer is dissolved and / or dispersed, and has a nonvolatile content of 60%.
~ 80 wt% and viscosity at 25 ° C of 20,000 cps
It is as follows. For this reason, the same operation and effect as those of the pressure-sensitive adhesive composition according to the third aspect are exhibited.

According to the fifth aspect, the pressure-sensitive adhesive composition of the present invention is an acrylic hot-melt pressure-sensitive adhesive. In this case, since the thermoplastic addition polymer has a branched structure (star-shaped block structure) in which the first polymer portion and the second polymer portion extend radially from the polyvalent mercaptan portion, they have the same molecular weight. Compared to linear polymers, block polymers, and graft polymers, they have low viscosity at the time of hot melt and have good workability. It has a larger cohesive force than a conventional adhesive containing a polymer for a hot melt resin, and thus has excellent heat resistance. The first polymer part is composed of a high glass transition point type acrylic polymer part having a glass transition point of 80 ° C. or higher, and the second polymer part is low glass having a glass transition point of −50 to −25 ° C. A transition point type acrylic polymer, wherein the weight ratio of the first polymer portion to the second polymer portion is from 20:80 to 35:65.
By improving the cohesion, heat resistance (particularly heat resistance physical properties) is excellent, and heat resistance and adhesiveness are balanced. Further, since the components constituting the polymer portion do not contain metal ions, they have excellent thermal stability during melt coating. Moreover, the thermoplastic addition polymer is 30,000-
By having a number average molecular weight of 60,000, the balance of physical properties such as hot melt workability and heat resistance is excellent.

According to the sixth aspect of the pressure-sensitive adhesive composition of the present invention, the first polymer part has a methyl methacrylate unit of 90 to 90%.
100% by weight and 0 to 10% by weight of other polymerizable monomer units, and the second polymer portion is 0 to 10% by weight of methyl methacrylate unit, 80 to 100% by weight of butyl acrylate unit and other polymerizable units. It is the same as the acrylic hot melt pressure-sensitive adhesive of the fifth embodiment except that it is composed of 0 to 10% by weight of a monomer unit. In this case, since the component constituting the polymer portion is composed of a (meth) acrylic acid derivative, S
Compared with IS and the like, it has excellent weather resistance as a hot melt adhesive, and also has good thermal stability during melt coating.

According to the seventh aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that the polyvalent mercaptan moiety is a residue of a 4- to hexavalent mercaptan, and the acrylic system according to the fifth or sixth aspect is Same as hot melt adhesive. In this case, since a highly branched structure is formed and the structure radially extends from the same center, the entanglement between the molecules is further increased, and the cohesion is larger than that of a conventionally known adhesive containing a polymer for a hot melt resin. It has power and therefore better heat resistance.

According to the eighth aspect, the pressure-sensitive adhesive composition of the present invention has the same structure as the fifth to seventh, except that the first polymer portion has a number average molecular weight of 2,000 to 6,000. It is the same as the acrylic hot melt pressure-sensitive adhesive of any of the embodiments. In this case, the number average molecular weight of the thermoplastic addition polymer is 3
It is possible to produce a hot-melt pressure-sensitive adhesive having excellent pressure-sensitive adhesive properties because the temperature can be suppressed to 000 to 60,000 and the properties based on the first polymer portion can be introduced into the thermoplastic addition polymer. Viscosity is not high and productivity is excellent.

According to the ninth aspect, the pressure-sensitive adhesive composition of the present invention comprises a thermoplastic addition polymer produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. Acrylic hot melt adhesive. The preparatory step comprises a first α, β capable of producing a polyvalent mercaptan and a high glass transition point type polymer having a glass transition point of 80 ° C. or higher.
-Preparing a first mixture containing an unsaturated monomer. The first polymerization step is a step of obtaining a reaction mixture by performing radical polymerization of the first mixture while leaving the unreacted mercapto group at 15 to 85 mol% with the mercapto group of the polyvalent mercaptan as a starting point. By this radical polymerization, a polymer in which the first polymer portion composed of the high glass transition point type polymer radially extends from the polyvalent mercaptan portion is generated. The adding step comprises adding a second α, β-unsaturated monomer to the reaction mixture to form a second mixture capable of forming a low glass transition point type polymer having a glass transition point of −50 to −25 ° C. This is the step of obtaining. The second polymerization step is a step of radically polymerizing the second mixture such that the unreacted mercapto group is reduced to 2 mol% or less starting from the unreacted mercapto group. By this radical polymerization, a thermoplastic addition polymer in which a second polymer portion composed of a low glass transition point type polymer radially extends from the polyvalent mercaptan portion of the polymer generated in the first polymerization step is generated. This thermoplastic addition polymer is
It has the same function and effect as the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the fifth aspect.

According to the tenth aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that the first α, β-unsaturated monomer comprises 90 to 100% by weight of methyl methacrylate and 0% of another polymerizable monomer. ~ 1
0% by weight, and the α, β-unsaturated monomer in the second mixture contains 0 to 10% by weight of methyl methacrylate, 80 to 100% by weight of butyl acrylate and 0 to 1% of another polymerizable monomer.
Except that it comprises 0% by weight, it is the same as the pressure-sensitive adhesive composition of the ninth embodiment. Therefore, the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the tenth aspect is the same as the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the sixth aspect,
It has the same effect.

According to the eleventh aspect, the pressure-sensitive adhesive composition of the present invention is the same as the pressure-sensitive adhesive composition of the ninth or tenth aspect except that the polyvalent mercaptan is a 4- to hexavalent mercaptan. is there. Therefore, the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the eleventh aspect is the same as the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the seventh aspect, and has the same effect.

According to the twelfth aspect of the pressure-sensitive adhesive composition of the present invention, the high glass transition point type acrylic polymer obtained in the first polymerization step has a number average molecular weight of 2,000 to 6,000. Except for this, it is the same as the pressure-sensitive adhesive composition of any of the ninth to eleventh embodiments. Therefore, the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the twelfth aspect is the same as the thermoplastic addition polymer contained in the pressure-sensitive adhesive composition of the eighth aspect, and has the same function and effect.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Adhesive Composition According to First Aspect] According to the first aspect, the adhesive composition of the present invention comprises a polyvalent mercaptan portion and a polyvalent mercaptan portion extending radially from the polyvalent mercaptan portion. A thermoplastic addition polymer having a first polymer portion and a second polymer portion.

The polyvalent mercaptan moiety refers to a remaining portion (residue) in which protons of a plurality of mercapto groups are dissociated from a polyvalent mercaptan described later (a mercaptan having two or more mercapto groups). The polyvalent mercaptan moiety is preferably a trivalent to hexavalent mercaptan described below, and more preferably a remaining part in which protons of a plurality of mercapto groups have been dissociated from a tetravalent to hexavalent mercaptan described below. The reason for this is that the thermoplastic addition polymer has a star-shaped block structure extending radially from the same center, so that the effect of entanglement (for example, high cohesion) between the polymer parts and the morphological change of the phase separation structure are reduced. This is because there is an advantage that can be expected. When the polyvalent mercaptan portion is the remaining portion where the proton of the mercapto group is dissociated from divalent mercaptan, the heat resistance of the pressure-sensitive adhesive composition may not be sufficient. Further, when the polyvalent mercaptan portion is the remaining portion in which the proton of the mercapto group is dissociated from the mercaptan having a valence of 7 or more, the thermoplastic addition polymer is difficult to take a structure in which the polymer portion radially extends from the same center, The desired physical properties may not be exhibited.

A polyvalent mercaptan is a compound having two or more mercapto groups per molecule. Mercaptans in which the number of mercapto groups per molecule is 2, 3,... Valuable mercaptans ... As polyvalent mercaptan, for example,
Diesters of diols such as ethylene glycol and 1,4-butanediol and carboxyl-containing mercaptans; compounds having three or more hydroxyl groups such as trimethylolpropane, pentaerythritol, dipentaerythritol and polyester compounds of carboxyl-containing mercaptans; Compounds having three or more mercapto groups such as trithioglycerin; 2-di-n-butylamino-
4,6-dimercapto-S-triazine, 2,4,6-
Triazine polyvalent thiols such as trimercapto-S-triazine; compounds obtained by adding hydrogen sulfide to a plurality of epoxy groups of a polyepoxy compound to introduce a plurality of mercapto groups; a plurality of carboxyl groups of a polyvalent carboxylic acid And an ester compound obtained by esterification of mercaptoethanol with any one of them. Any one of them can be used alone or in combination of two or more.
Here, the carboxyl group-containing mercaptans are compounds having one mercapto group and one carboxyl group, such as thioglycolic acid, mercaptopropionic acid, and thiosalicylic acid. It should be noted that a mercaptan having only one mercapto group cannot be used as a mercaptan portion of a thermoplastic addition polymer because it does not give a structure in which the polymer portion extends radially.

From the viewpoint of forming a polymer having a star block structure, the polyvalent mercaptan is preferably a compound having 3 to 6 mercapto groups (that is, a 3 to 6 functional mercaptan), more preferably 4 to 6 Compounds having six mercapto groups (i.e., 4-6 functional mercaptans). Mercaptans having only one mercapto group do not provide a radially extended structure of the polymer portion. A mercaptan having more than six mercapto groups does not have a structure extending radially from the same center, and thus may not exhibit desired physical properties.

Examples of the polyvalent mercaptan include trifunctional mercaptans such as trithioglycerin, trimethylolpropane trithioglycolate, and trimethylolpropane trithiopropionate; pentaerythritol tetrakisthioglycolate and pentaerythritol tetrakisthioprolate. 4-functional mercaptans such as pionates; hexafunctional mercaptans such as dipentaerythritol hexakisthioglycolate and dipentaerythritol hexakisthiopropionate; compounds obtained by adding hydrogen sulfide to trivalent to hexavalent epoxy compounds; Examples thereof include mercaptoethanol adducts of trivalent to hexavalent carboxylic acids, and at least one of them is used.

The first and second polymer portions extend radially from the polyvalent mercaptan portion. The polymer portion extends radially from the polyvalent mercaptan portion,
When two polymer portions per polymer extend in two directions from the polyvalent mercaptan portion (including the case where the polymer portion extends linearly), three or more polymer portions per polymer are multivalent. This refers to the case where it extends in three or more directions from the mercaptan portion. A carbon atom at one end of the polymer moiety is bonded to a sulfur atom derived from the mercapto group of the polyvalent mercaptan moiety.

The first polymer part and the second polymer part are:
Each of them usually has a number average molecular weight of 1,000 to 15,
000, preferably 3,000 to 100,000. If the number average molecular weight of the polymer portion falls below the above range, it may not be possible to introduce properties based on the polymer portion into the thermoplastic addition polymer, and if it exceeds, the viscosity of the hot melt viscosity or high solid solvent type pressure-sensitive adhesive may be increased. Not only does the viscosity increase, but also the viscosity during the production increases, which may be undesirable in terms of productivity.

The thermoplastic addition polymer has one or more first polymer portions and one or more second polymer portions per polymer. The polymer portion is a portion having a homopolymer or copolymer structure obtained by radical polymerization of a polymerizable unsaturated monomer. The polymer portion obtained by radical polymerization is more diverse in the type of composition than the polymer portion generated by ionic polymerization such as anionic polymerization, except that the type of monomer used is also capable of radical polymerization. It is not particularly limited, and it may be a copolymer.

The first polymer portion comprises a high glass transition point polymer having a glass transition point of 273K or more, preferably 333K or more, more preferably 353K or more. The first polymer portion comprising the high glass transition point type polymer is
The pressure-sensitive adhesive composition has excellent heat resistance because it forms a discontinuous phase by phase separation from the polymer portion and has a pseudo-crosslinked structure. The higher the glass transition point of the first polymer portion, the greater the effect of improving the heat resistance.

The second polymer portion comprises a low glass transition point polymer having a glass transition point of less than 273K, preferably less than 263K, more preferably less than 250K. The second polymer portion made of the low glass transition point polymer is the first polymer portion.
It separates from the polymer portion to form a continuous phase, and exhibits adhesiveness. The lower the glass transition point of the second polymer portion, the greater the effect of increasing the adhesive strength.

The difference in the glass transition point between the first polymer portion and the second polymer portion is that when the polymer portion is composed of a homopolymer, the difference between the monomer units constituting the polymer and the polymer When the portion is composed of a copolymer, it can be obtained by a difference in monomer units and / or a difference in the ratio of monomer units. The first polymer portion is composed of a high glass transition point type polymer produced by radical polymerization of a first α, β-unsaturated monomer described later. In addition, the second polymer portion includes a second α,
It consists of a low glass transition point type polymer produced by radical polymerization of a β-unsaturated monomer.

The first α, β-unsaturated monomer is obtained by radical polymerization at a temperature of 273 K or more, preferably 333 K or more.
As described above, any monomer can be used as long as it produces a high glass transition point type polymer (homopolymer or copolymer) having a glass transition point of preferably 353 K or more. For example, (meth) acrylic acid; alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms, phenyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentadienyl (meth) ) Acrylate, adamantyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate,
(Meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and ethoxyethoxyethyl (meth) acrylate; styrene-based polymerizable polymers such as α-methylstyrene, vinyltoluene, and styrene Monomers; vinyl ethers represented by methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, vinyl acetate, etc .; fumaric acid, monoalkyl esters of fumaric acid, dialkyl esters of fumaric acid; maleic acid, monoalkyl esters of maleic acid, maleic acid Dialkyl esters of acids; itaconic acid, monoalkyl esters of itaconic acid,
Dialkyl esters of itaconic acid; half esters of succinic or phthalic anhydride with hydroxyethyl (meth) acrylate; (meth) acrylonitrile, butadiene, isoprene, vinyl chloride, vinylidene chloride,
Examples thereof include vinyl ketone, vinyl pyridine, and vinyl carbazole.
These can be used together.

As the second α, β-unsaturated monomer, the first α, β-unsaturated monomer remaining without reacting with the second α, β-unsaturated monomer in the first polymerization step is used. A mixture with a saturated monomer or the second α, β-unsaturated monomer itself may have a glass transition point of less than 273K, preferably less than 263K, more preferably less than 250K by radical polymerization. Any monomer can be used as long as it produces a glass transition point polymer (homopolymer or copolymer). For example, alkyl acrylates having an alkyl group having 2 to 18 carbon atoms, such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and dodecyl acrylate; hydroxyethyl acrylate, hydroxypropyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, ethoxyethoxyethyl acrylate And so on.
Any of them can be used alone or in combination of two or more. Further, the first α, β-unsaturated monomer may be contained within a range satisfying a glass transition temperature of less than 273K.

By selecting a combination of the first polymer portion and the second polymer portion, it becomes possible to achieve both conflicting performances such as heat resistance and tackiness, and adhesion and toughness. For example, when a thermoplastic addition polymer is used as a pressure-sensitive adhesive (pressure-sensitive adhesive), the second polymer portion composed of a low glass transition point type polymer has a first polymer portion composed of a high glass transition point type polymer. The thermoplastic addition polymer is designed to occupy more, more than more, coalescing parts.

The number average molecular weight of the thermoplastic addition polymer is 1
It is between 000 and 200,000. When the number average molecular weight is below the above range, heat resistance is insufficient and cohesive strength (holding power) during use is reduced. When the number average molecular weight exceeds the above range, the viscosity of the pressure-sensitive adhesive solution and the hot melt viscosity are high, and the handleability is deteriorated. Considering the balance of sufficiently high heat resistance and sufficiently low viscosity of the pressure-sensitive adhesive solution and hot melt viscosity, the number average molecular weight of the thermoplastic addition polymer is preferably 10,000 to 100,000.

The thermoplastic addition polymer has a molecular weight distribution (Mw
/ Mn) is preferably 6 or less. In a hot melt pressure-sensitive adhesive, the molecular weight distribution is preferably 4 or less, and when the molecular weight distribution is larger than 4, the hot melt viscosity may be high and the workability may be deteriorated when the high molecular weight component is large, and when the low molecular weight component is large. Heat resistance may be reduced.

Preferred examples of the pressure-sensitive adhesive composition according to the first embodiment of the present invention are described below. (1) A thermoplastic addition polymer having a polyvalent mercaptan portion, and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion, wherein the first polymer portion is 273K or more. The pressure-sensitive adhesive composition according to the first aspect, comprising a high glass transition point polymer having a glass transition point of, and the second polymer portion comprising a low glass transition point polymer having a glass transition point of less than 250K. . (2) a thermoplastic addition polymer having a polyvalent mercaptan portion and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion, wherein the first polymer portion is 333K or more. The pressure-sensitive adhesive composition according to the first embodiment, wherein the pressure-sensitive adhesive composition comprises a high glass transition point polymer having a glass transition point of 2, and the second polymer portion comprises a low glass transition point polymer having a glass transition point of less than 273K. . (3) a thermoplastic addition polymer having a polyvalent mercaptan portion and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion, wherein the first polymer portion is 333K or more. The pressure-sensitive adhesive composition according to the first aspect, comprising a high glass transition point polymer having a glass transition point of, and the second polymer portion comprising a low glass transition point polymer having a glass transition point of less than 250K. . (4) A thermoplastic addition polymer having a polyvalent mercaptan portion and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion, wherein the first polymer portion is 353K or more. The pressure-sensitive adhesive composition according to the first embodiment, wherein the pressure-sensitive adhesive composition comprises a high glass transition point polymer having a glass transition point of 2, and the second polymer portion comprises a low glass transition point polymer having a glass transition point of less than 273K. . (5) a thermoplastic addition polymer having a polyvalent mercaptan portion and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion, wherein the first polymer portion is 353K or more. The pressure-sensitive adhesive composition according to the first aspect, comprising a high glass transition point polymer having a glass transition point of, and the second polymer portion comprising a low glass transition point polymer having a glass transition point of less than 250K. . (6) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer portion is 1,000 to 150,000
0, the number average molecular weight of the second polymer portion is 1,000 to 15
The pressure-sensitive adhesive composition according to the first aspect, wherein the pressure-sensitive adhesive composition is 0.000. (7) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer portion is from 3,000 to 100,00
0, the number average molecular weight of the second polymer portion is 3,000-10
The pressure-sensitive adhesive composition according to the first aspect, wherein the pressure-sensitive adhesive composition is 0.000. (8) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer portion is 1,000 to 150,000
0, the number average molecular weight of the second polymer portion is 1,000 to 15
000, the number average molecular weight of the thermoplastic addition polymer is 1
The pressure-sensitive adhesive composition according to the first aspect, wherein the pressure-sensitive adhesive composition is from 000 to 200,000. (9) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer portion is from 3,000 to 100,00
0, the number average molecular weight of the second polymer portion is 3,000-10
000, the number average molecular weight of the thermoplastic addition polymer is 1
The pressure-sensitive adhesive composition according to the first aspect, wherein the pressure-sensitive adhesive composition is from 000 to 100,000. (10) The pressure-sensitive adhesive composition according to the first aspect, wherein in any one of the above (1) to (9), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 6 or less. (11) The pressure-sensitive adhesive composition according to the first aspect, wherein the polyvalent mercaptan moiety is a residue of a 3 to 6-functional mercaptan. (12) The pressure-sensitive adhesive composition according to the first aspect, wherein in any one of the above (1) to (10), the polyvalent mercaptan moiety is a residue of a 3 to 6-functional mercaptan. (13) The pressure-sensitive adhesive composition according to any one of the above (11) to (12), wherein the polyvalent mercaptan moiety is a residue of a 4- to 6-functional mercaptan.

The thermoplastic addition polymer according to the first embodiment is produced, for example, by the method for producing a thermoplastic addition polymer according to the second embodiment. [Pressure-sensitive adhesive composition according to second embodiment] The pressure-sensitive adhesive composition of the present invention, according to the second embodiment, is prepared by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. It contains the obtained thermoplastic addition polymer.

The preparatory step was carried out using a polyvalent mercaptan and 273K.
This is a step of preparing a first mixture containing a first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having the above glass transition point. Since the first α, β-unsaturated monomer and the polyvalent mercaptan have already been described in the first embodiment, the description is omitted here.

When the polymerization is carried out in the presence of a polyvalent mercaptan, the polymerization proceeds from the mercapto group of the polyvalent mercaptan as a starting point, so that the molecular weight distribution is narrow (for example, the molecular weight distribution (Mw / Mn) is 6 or less) and the polymer is highly branched. A thermoplastic addition polymer having a modified star block structure is formed. The first mixture contains a polyvalent mercaptan, for example, from 0.01 to 1 based on 100 parts by weight of the first α, β-unsaturated monomer.
Contains 0 parts by weight. When the amount of the polyvalent mercaptan is out of the above range, the number average molecular weight of the first polymer portion is 1,000 to 15
It may be out of the range of 10,000 or the number average molecular weight of the thermoplastic addition polymer may be out of the range of 10,000 to 200,000. In consideration of this point, the amount of the polyvalent mercaptan is more preferably 0.05 to 5 parts by weight.

The first mixture may further contain a medium in which the first α, β-unsaturated monomer and the polyvalent mercaptan are dissolved and / or dispersed. The medium may be any medium in which the monomer and the obtained polymer are soluble.
The amount of the medium is the amount of the first α, β-unsaturated monomer and the second α, β
For example, 0 to 2 with respect to the total amount with the β-unsaturated monomer.
00% by weight, preferably 0 to 100% by weight. If the ratio exceeds the above range, the polymerization rate is lowered and the cost in terms of solid content is increased, which is not industrially preferable. Examples of the medium include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and pentane; Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone are exemplified. The organic solvent may be a single solvent or a mixed solvent.

The first polymerization step is a step of obtaining a reaction mixture by performing radical polymerization of the first α, β-unsaturated monomer starting from the mercapto group of the polyvalent mercaptan. The radical polymerization can be carried out by a general radical polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. In order to obtain an inexpensive polymer, a bulk polymerization method containing no extra volatile components is preferred.

The polymerization temperature is preferably from 30 to 200 ° C.
More preferably, the temperature is 100 to 150 ° C., which enables stable bulk polymerization without using a polymerization initiator. In the first polymerization step,
Conventional radical polymerization initiators (eg, azo-based polymerization initiators such as 2,2'-azobisisobutyronitrile and 2,2'-azobiscyclohexanecarbonitrile; peroxide-based polymerization initiators such as benzoyl peroxide) And the like, but usually not more than 1/3, preferably not more than 1/10, more preferably not used, of polyvalent mercaptan in weight ratio. When the polymerization initiator is used in a larger amount than the above ratio, in addition to the polymer portion extended from the polyvalent mercaptan, a large amount of the polymer extended from the polymerization initiator is generated, and a thermoplastic addition polymer having a star block structure Generation efficiency is reduced.

By the radical polymerization in the first polymerization step, a high glass transition point type polymer having a glass transition point of 273K or more at one or more sulfur residues of the mercapto group in each molecule of the polyvalent mercaptan is obtained. A product having the carbon atom at one end of the carbon chain bonded is obtained. The product contains a first polymer portion radially extending from the polyvalent mercaptan portion and has unreacted mercapto groups. The first polymer portion comprises a high glass transition point polymer. In order to efficiently bind one end of the first polymer portion to the sulfur residue, it is preferable not to add an unnecessary polymerization initiator to the polymerization system. The radical polymerization in the first polymerization step is performed, for example, at a conversion of 30 to 95%, preferably at a conversion of 50 to 90%.
%, More preferably until the conversion reaches 70 to 85%. If the polymerization rate is lower than the above range, sufficient heat resistance may not be obtained, or a large amount of the first α, β-unsaturated monomer remains, so that the second polymer portion obtained in the second polymerization step May be insufficient in tackiness. If the degree of polymerization is higher than the above range, the remaining mercapto groups decrease, the production efficiency of the block polymer becomes poor, and sufficient heat resistance may not be obtained. After the first polymerization step, the remaining first α, β-unsaturated monomer may be volatilized and removed after the first polymerization step in order to easily generate different polymer portions in the first polymerization step and the second polymerization step. It is possible.

The addition step comprises adding a second α, β-unsaturated monomer to the reaction mixture obtained in the first polymerization step,
This is a step of obtaining a second mixture capable of producing a low glass transition point type polymer having a glass transition point of less than. The second α, β
-Unsaturated monomers have already been described in the first embodiment, and thus description thereof is omitted here.

When the thermoplastic addition polymer is used as a pressure-sensitive adhesive (pressure-sensitive adhesive), the second polymer portion composed of a low glass transition type polymer is replaced with the first glass portion composed of a high glass transition point polymer. The thermoplastic addition polymer is designed to occupy more, most, more than the polymer portion. The combination of the first α, β-unsaturated monomer and the second α, β-unsaturated monomer is obtained by introducing a block structure having a polymer portion having a different Tg. Is set from the viewpoint of increasing the cohesive force of the polymer. First, a first α, β-unsaturated monomer capable of producing a high glass transition point polymer having a glass transition point of 273K or more, and a low glass transition point polymer having a glass transition point of less than 273K In combination with a second α, β-unsaturated monomer capable of producing From the viewpoint of further improving the cohesive strength of the thermoplastic addition polymer, preferably, the first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having a glass transition point of 333 K or more. And a second material capable of producing a low glass transition type polymer having a glass transition point of less than 250K.
In combination with an α, β-unsaturated monomer, more preferably a first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having a glass transition point of 353 K or more. , A second α, β-unsaturated monomer capable of producing a low glass transition point type polymer having a glass transition point of less than 250K.

The amount of the second α, β-unsaturated monomer is
The amount is, for example, in the range of 50 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the α, β-unsaturated monomer. Outside of this range, the thermoplastic addition polymer may not have the performance derived from the star block structure. Considering this point, the amount of the second α, β-unsaturated monomer is 1
00 to 1000 parts by weight is preferred.

In the addition step, a method of adding the second α, β-unsaturated monomer at a time or a method of adding it dropwise may be employed. The second mixture may further include a medium in which the polymer produced in the first polymerization step and the second α, β-unsaturated monomer are dissolved and / or dispersed. The medium may be any medium in which the monomer and the obtained polymer are soluble. The amount of the medium is, for example, 0 to 200% by weight, preferably 0 to 100% by weight, based on the total amount of the first α, β-unsaturated monomer and the second α, β-unsaturated monomer.
% By weight. If the ratio exceeds the above range, the polymerization rate is lowered and the cost in terms of solid content is increased, which is not industrially preferable. Examples of the medium include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and pentane; Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone are exemplified. The organic solvent may be a single solvent or a mixed solvent.

The second polymerization step is a step of performing radical polymerization of the monomers contained in the second mixture. This radical polymerization is carried out starting from all or a part of the remaining mercapto groups in the polyvalent mercaptan to produce a low glass transition point type polymer. A product is obtained in which one end of the second polymer portion is bonded to the sulfur residue of the mercapto group serving as the starting point. The second polymer portion comprises a low glass transition point polymer. This product may have unreacted mercapto groups. In this case, by repeating the second polymerization step twice, a polymer portion having a third different composition is introduced, and by repeating the second polymerization step three times, the third and fourth different compositions are obtained. The polymer portion having a different composition can be introduced each time the number of repetitions of the second polymerization step is increased by introducing the polymer portion having the same.

The radical polymerization can be carried out by a conventional radical polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. In order to obtain an inexpensive polymer, a bulk polymerization method containing no extra volatile components is preferred. The polymerization temperature is preferably from 30 to 200 ° C., more preferably from 100 to 1 to allow stable bulk polymerization without using a polymerization initiator.
50 ° C.

In the second polymerization step, a conventional radical polymerization initiator (for example, an azo polymerization initiator such as 2,2'-azobisisobutyronitrile and 2,2'-azobiscyclohexanecarbonitrile; Peroxide initiators such as benzoyl oxide) can be used, but are usually 1/3 or less, preferably 1/1, by weight of the polyvalent mercaptan.
0 or less, more preferably not used. When the polymerization initiator is used in a larger amount than the above ratio, in addition to the polymer portion extended from the polyvalent mercaptan, a large amount of the polymer extended from the polymerization initiator is generated, and a thermoplastic addition polymer having a star block structure Generation efficiency is reduced.

After completion of the addition in the second polymerization step, it is possible to carry out radical polymerization for aging, if necessary. When the reaction mixture obtained in the second polymerization step does not contain a volatile component such as a solvent or a residual monomer, a thermoplastic addition polymer can be obtained as it is. When the reaction mixture contains a volatile component, a thermoplastic addition polymer is obtained by removing the volatile component using a device such as a twin screw extruder or a thin film evaporator.

In the second embodiment, the polymerization rate in the first polymerization step is set to 50% or more, and if necessary, the remaining polymerizable unsaturated monomer is volatilized and removed. When added together, the first polymer portion composed of a high glass transition point type polymer and the second polymer portion composed of a low glass transition point type polymer are used.
A thermoplastic addition polymer having a polymer portion (or a thermoplastic addition polymer of the pressure-sensitive adhesive composition according to the first embodiment)
Is obtained.

Preferred examples of the pressure-sensitive adhesive composition according to the second embodiment are described below. (1) As the first α, β-unsaturated monomer, 273K
The second α, β-unsaturated monomer having a low glass transition point having a glass transition point of less than 250 K is used as a second α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the second aspect, which uses a substance capable of forming coalescence. (2) 333K as the first α, β-unsaturated monomer
The second α, β-unsaturated monomer having a low glass transition point of less than 273K is used as the second α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the second aspect, which uses a substance capable of forming coalescence. (3) 333K as the first α, β-unsaturated monomer
The second α, β-unsaturated monomer having a low glass transition point having a glass transition point of less than 250 K is used as a second α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the second aspect, which uses a substance capable of forming coalescence. (4) 353 K as the first α, β-unsaturated monomer
The second α, β-unsaturated monomer having a low glass transition point of less than 273K is used as the second α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the second aspect, which uses a substance capable of forming coalescence. (5) 353K as the first α, β-unsaturated monomer
The second α, β-unsaturated monomer having a low glass transition point having a glass transition point of less than 250 K is used as a second α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the second aspect, which uses a substance capable of forming coalescence. (6) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer produced in the polymerization step is 1,000
The pressure-sensitive adhesive composition according to the second embodiment, which is from 150,000 to 150,000. (7) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer produced in the polymerization step is 3,000
The pressure-sensitive adhesive composition according to the second embodiment, wherein the pressure-sensitive adhesive composition is from 100 to 100,000. (8) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer produced in the polymerization step is 1,000
The pressure-sensitive adhesive composition according to the second embodiment, wherein the number average molecular weight of the thermoplastic addition polymer is 10,000 to 200,000. (9) In any one of the above (1) to (5), the first
The number average molecular weight of the polymer produced in the polymerization step is 3,000
The pressure-sensitive adhesive composition according to the second embodiment, wherein the number average molecular weight of the thermoplastic addition polymer is from 50,000 to 150,000. (10) The pressure-sensitive adhesive composition according to the second aspect, wherein in any one of the above (1) to (9), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 6 or less. (11) The pressure-sensitive adhesive composition according to the second embodiment, wherein the polyvalent mercaptan is a 3- to 6-functional mercaptan. (12) The method according to any of (1) to (10) above, wherein the polyvalent mercaptan is a 3 to 6-functional mercaptan.
The pressure-sensitive adhesive composition according to the embodiment. (13) The method according to any of (11) to (12) above, wherein the polyvalent mercaptan is a 4- to 6-functional mercaptan.
The pressure-sensitive adhesive composition according to the embodiment. [Adhesive composition according to third aspect] According to the third aspect, the adhesive composition according to the third aspect is characterized in that the adhesive composition according to the first aspect or the second aspect has a thermoplastic additive weight. It further contains an organic solvent in which the coalesced is dissolved and / or dispersed, has a nonvolatile content of 60 to 80% by weight, and a viscosity at 25 ° C. of 20,000 cps or less. This pressure-sensitive adhesive composition is a high solid solvent type pressure-sensitive adhesive.

As the organic solvent, the first embodiment or the second embodiment
Any type may be used as long as the thermoplastic addition polymer according to the embodiment can be dissolved and / or dispersed, for example, toluene,
Aromatic hydrocarbons such as xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and pentane;
Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; and organic solvents such as alcohols such as methanol, ethanol, propanol and butanol. The organic solvent may be a single solvent or a mixed solvent.

The pressure-sensitive adhesive composition according to the third embodiment has a nonvolatile content of 60 to 80% by weight. The non-volatile content is a thermoplastic addition polymer. If the non-volatile content exceeds 80% by weight, there is a problem that the adhesive properties cannot be satisfied while maintaining the viscosity of 20,000 cps or less. There is a problem that the improvement effect (low VOC: reduction of volatile organic compounds), the energy saving effect, and the line speed-up effect are reduced. Satisfies the adhesive properties while maintaining the viscosity of the adhesive composition at 20,000 cps or less, and improves the environmental problems and energy saving effects, which are advantages of high solidification.
The non-volatile content is preferably 65 to 75% by weight from the viewpoint of reducing the decrease in the line speed-up effect.

The pressure-sensitive adhesive composition of the third embodiment has a viscosity at 25 ° C. of 20,000 cps or less even at a nonvolatile concentration of the above range because the thermoplastic addition polymer has a low molecular weight. When the viscosity is larger than 20,000 cps, the coating workability or the coating property is poor. The viscosity is preferably 10,000 cps or less from the viewpoint that there is an advantage that the coatability is good and the line speed is increased. The viscosity is measured using a B-type viscometer (BM
(Type), # 4, values measured at 25 ° C. under 30 rpm.

If the thermoplastic addition polymer is, for example, 10,0
00 to 30,000, preferably 13,000 to 20,
When it has a number average molecular weight of 000, it has the further advantage of being excellent in the balance between heat resistance and adhesive properties, while being high solid and low in viscosity. As a method of dissolving and / or dispersing a thermoplastic addition polymer in an organic solvent, for example, it is a common method to coexist during the polymerization step. In some cases, the thermoplastic addition polymer and the organic solvent are mixed. It may be dissolved by heating.

Preferred examples of the pressure-sensitive adhesive composition according to the third embodiment are described below. (1) a nonvolatile content of 65 to 75% by weight,
The pressure-sensitive adhesive composition according to the third aspect, which has a viscosity at ℃ of 20,000 cps or less. (2) a nonvolatile component concentration of 60 to 80% by weight;
The pressure-sensitive adhesive composition according to the third aspect, which has a viscosity at 10,000 ° C. of 10,000 cps or less. (3) a nonvolatile content of 65 to 75% by weight;
The pressure-sensitive adhesive composition according to the third aspect, which has a viscosity at 10,000 ° C. of 10,000 cps or less. (4) In any one of the above (1) to (3), the first
The polymer portion is composed of a high glass transition point type polymer having a glass transition point of 333 K or more, and the second polymer portion is 250
The pressure-sensitive adhesive composition according to the third aspect, comprising a low glass transition point type polymer having a glass transition point of less than K. (5) In any one of the above (1) to (3), the first
The polymer portion is composed of a high glass transition type polymer having a glass transition point of 353 K or more, and the second polymer portion is 250
The pressure-sensitive adhesive composition according to the third aspect, comprising a low glass transition point type polymer having a glass transition point of less than K. (6) In any one of the above (1) to (3), the first
The polymer portion is composed of a high glass transition point type polymer having a glass transition point of 353 K or more, and the second polymer portion is 230
The pressure-sensitive adhesive composition according to the third aspect, comprising a low glass transition point type polymer having a glass transition point of less than K. (7) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer part is 1,000 to 10,000.
0, the number average molecular weight of the second polymer portion is 1,000-2.
The pressure-sensitive adhesive composition according to the third aspect, which is 000. (8) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer portion is 1,500 to 5,000,
The number average molecular weight of the second polymer portion is from 3,000 to 15.0
00. The pressure-sensitive adhesive composition according to the third aspect, wherein the pressure-sensitive adhesive composition is 00. (9) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer part is 1,000 to 10,000.
0, the number average molecular weight of the second polymer portion is 1,000-2.
000, the number average molecular weight of the thermoplastic addition polymer is 1
The pressure-sensitive adhesive composition according to the third embodiment, wherein the pressure-sensitive adhesive composition has a molecular weight of 3,000 to 30,000. (10) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer portion is 1,500 to 5,000,
The number average molecular weight of the second polymer portion is from 3,000 to 15.0
00, the number average molecular weight of the thermoplastic addition polymer is 13,00
The pressure-sensitive adhesive composition according to the third aspect, which is 0 to 20,000. (11) The pressure-sensitive adhesive composition according to the third aspect, wherein in any one of the above (4) to (10), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 6 or less. (12) The pressure-sensitive adhesive composition according to the third aspect, wherein in any one of the above (4) to (11), the polyvalent mercaptan moiety is a residue of a 3 to 6-functional mercaptan. (13) The pressure-sensitive adhesive composition according to the third aspect, wherein in any one of the above (4) to (11), the polyvalent mercaptan moiety is a residue of a 4- to 6-functional mercaptan. (14) In any one of the above (1) to (3), the first
As the α, β-unsaturated monomer, one capable of producing a high glass transition point type polymer having a glass transition point of 333 K or more is used, and as the second α, β-unsaturated monomer, 250
The pressure-sensitive adhesive composition according to the third embodiment, which uses a material capable of producing a low glass transition point type polymer having a glass transition point of less than K. (15) In any one of the above (1) to (3), the first
As the α, β-unsaturated monomer, one capable of producing a high glass transition point type polymer having a glass transition point of 353 K or more is used, and as the second α, β-unsaturated monomer, 250
The pressure-sensitive adhesive composition according to the third embodiment, which uses a material capable of producing a low glass transition point type polymer having a glass transition point of less than K. (16) In any one of the above (1) to (3), the first
As the α, β-unsaturated monomer, one capable of producing a high glass transition point type polymer having a glass transition point of 353 K or more is used, and as the second α, β-unsaturated monomer, 230
The pressure-sensitive adhesive composition according to the third embodiment, which uses a material capable of producing a low glass transition point type polymer having a glass transition point of less than K. (17) In any one of the above (14) to (16), the first
The number average molecular weight of the polymer produced in the polymerization step is 1,000
The pressure-sensitive adhesive composition according to the third aspect, which is from 10,000 to 10,000. (18) In any one of the above (14) to (16), the first
The number average molecular weight of the polymer produced in the polymerization step is 3,000
The pressure-sensitive adhesive composition according to the third aspect, which is from 6,000 to 6,000. (19) In any one of the above (14) to (16), the first
The number average molecular weight of the polymer produced in the polymerization step is 1,000
The pressure-sensitive adhesive composition according to the third embodiment, wherein the number average molecular weight of the thermoplastic addition polymer is 10,000 to 30,000. (20) In any one of the above (14) to (16), the first
The number average molecular weight of the polymer produced in the polymerization step is 3,000
~ 6,000, the number average molecular weight of the thermoplastic addition polymer is 1
The pressure-sensitive adhesive composition according to the third embodiment, which has a molecular weight of 3,000 to 20,000. (21) The pressure-sensitive adhesive composition according to the third aspect, wherein in any one of the above (14) to (20), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 6 or less. (22) The polyhydric mercaptan according to any one of the above (14) to (21), wherein the polyvalent mercaptan is a 3 to 6-functional mercaptan.
The pressure-sensitive adhesive composition according to the embodiment. (23) The polyhydric mercaptan according to any of (14) to (21), wherein the polyvalent mercaptan is a 4- to 6-functional mercaptan.
The pressure-sensitive adhesive composition according to the embodiment. [Pressure-sensitive adhesive composition according to the fourth aspect] The pressure-sensitive adhesive composition of the present invention, according to the fourth aspect, comprises a thermoplastic addition polymer,
It contains an organic solvent in which a thermoplastic addition polymer is dissolved and / or dispersed, has a nonvolatile content of 60 to 80% by weight, and has a viscosity at 25 ° C of 20,000 cps or less. This pressure-sensitive adhesive composition is a high solid solvent type pressure-sensitive adhesive.

The thermoplastic addition polymer is a graft polymer having a first polymer portion composed of a high glass transition point type polymer and a second polymer portion composed of a low glass transition point type polymer. The first polymer portion is composed of a high glass transition point type polymer produced by radical polymerization of the first α, β-unsaturated monomer described in the first embodiment. The second polymer portion is a low glass transition point polymer formed by radical polymerization of the α, β-unsaturated monomer in the second mixture described in the first embodiment.

The thermoplastic addition polymer has, for example, a graft structure in which a second polymer portion is branched from a first polymer portion, and a graft structure in which a first polymer portion is branched from a second polymer portion. A thermoplastic addition polymer having a graft structure in which a second polymer portion is branched from a first polymer portion, a first α, β-unsaturated monomer capable of forming a high glass transition point polymer; It can be obtained by radical polymerization of a low glass transition point type polymer having a polymerizable unsaturated bond group at one end with a polymerization initiator.

Examples of the low glass transition point polymer include alkyl acrylates having an alkyl group having 2 to 18 carbon atoms, such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and dodecyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and the like. It is produced by polymerizing an α, β-unsaturated monomer containing at least one selected from the group consisting of methoxyethyl acrylate, ethoxyethyl acrylate, and ethoxyethoxyethyl acrylate.

As the low glass transition point type polymer, a so-called macromonomer having a polymerizable double bond at one end of a polymer obtained from the above α, β-unsaturated monomer can be used. As the first α, β-unsaturated monomer capable of producing a high glass transition point type polymer, the same one as used in the pressure-sensitive adhesive composition of the second embodiment is used.

The thermoplastic addition polymer having a graft structure in which the first polymer portion is branched from the second polymer portion is as follows:
A second α, β-unsaturated monomer capable of forming a low glass transition point polymer and a high glass transition point polymer having a polymerizable unsaturated bond group at one end are radically reacted with a polymerization initiator. Obtained by polymerization. The high glass transition point polymer is obtained, for example, by polymerizing an α, β-unsaturated monomer containing at least one selected from the group consisting of styrene, vinyl acetate, acrylonitrile, methacrylonitrile and methyl methacrylate. Made.

Examples of the high glass transition point polymer include an organic solvent used for polymerization of a usual (meth) acrylic polymer,
For example, a commercially available macromonomer that dissolves in an organic solvent such as ethyl acetate or toluene can be used. As commercially available macromonomers, for example, polystyrene, poly (acrylonitrile-styrene), polymethyl methacrylate, polyvinyl acetate and the like having a polymerizable double bond group at one end can be used.

A second compound capable of producing a low glass transition point type polymer
As the α, β-unsaturated monomer, the same one as used in the pressure-sensitive adhesive composition of the second embodiment is used. The radical polymerization can be carried out by bulk polymerization or solution polymerization, which are ordinary radical polymerization methods. The polymerization temperature varies depending on the polymerization initiator, for example, 30 to 200 ° C,
Preferably it is 60-150 degreeC. For the polymerization, a usual radical polymerization initiator (for example, an azo-based polymerization initiator such as 2,2'-azobisisobutyronitrile and 2,2'-azobiscyclohexanecarbonitrile); and a peroxide such as benzoyl peroxide Compound polymerization initiator) can be used in an amount usually used.

The combination of the high glass transition point polymer and the low glass transition point type polymer is determined from the viewpoint of increasing the cohesive strength of the thermoplastic addition polymer by having polymer portions having different Tg. First, a high glass transition point type polymer portion having a glass transition point of 273K or more;
Combination with a low glass transition point polymer moiety having a glass transition point of less than. From the viewpoint of further improving the cohesive strength of the thermoplastic addition polymer, preferably,
Combination of a high glass transition point polymer portion having a glass transition point of 333 K or more and a low glass transition point polymer portion having a glass transition point of less than 250 K, more preferably having a glass transition point of 353 K or more A combination of a high glass transition point polymer portion and a low glass transition point polymer portion having a glass transition point of less than 250K, more preferably a high glass transition point polymer portion having a glass transition point of 353K or more. , A low glass transition point polymer portion having a glass transition point of less than 230K.

The amount of the second polymer part is, for example, in the range of 50 to 2,000 parts by weight based on 100 parts by weight of the first polymer part. Outside of this range, the thermoplastic addition polymer may not have the performance derived from the graft structure. Considering this point, the amount of the second polymer portion is 100
~ 1000 parts by weight are preferred. The organic solvent may be any one in which the thermoplastic addition polymer can be dissolved and / or dispersed, and examples thereof include an organic solvent used in the pressure-sensitive adhesive composition of the third embodiment. The organic solvent may be a single solvent or a mixed solvent.

In the pressure-sensitive adhesive composition of the fourth embodiment, the non-volatile content is 60 to 80% by weight. The non-volatile content is a thermoplastic addition polymer. If the non-volatile content exceeds 80% by weight, there is a problem that the adhesive properties cannot be satisfied while maintaining the viscosity of 20,000 cps or less. There is a problem that the improvement effect (low VOC: reduction of volatile organic compounds), the energy saving effect, and the line speed-up effect are reduced. Satisfies the adhesive properties while maintaining the viscosity of the adhesive composition at 10,000 cps or less, and improves the environmental problems and energy saving effects, which are the merits of high solidification.
The non-volatile content is preferably 65 to 75% by weight from the viewpoint of reducing the decrease in the line speed-up effect.

The pressure-sensitive adhesive composition of the fourth embodiment has a viscosity at 25 ° C. of 20,000 cps or less even at a non-volatile content within the above range because the thermoplastic addition polymer has a low molecular weight. When the viscosity is larger than 20,000 cps, the coating workability or the coating property is poor. The viscosity is preferably 10,000 cps or less from the viewpoint that there is an advantage that the coatability is good and the line speed is increased. The viscosity is measured using a B-type viscometer (BM
(Type), # 4, values measured at 25 ° C. under 30 rpm.

If the thermoplastic addition polymer is, for example, 10,0
00 to 30,000, preferably 13,000 to 20,
When it has a number average molecular weight of 000, it has the further advantage of being excellent in the balance between heat resistance and adhesive properties, while being high solid and low in viscosity. The first polymer portion of the thermoplastic addition polymer or the high glass transition point polymer portion formed by the first α, β-unsaturated monomer is, for example, 1,000 to 10,000, preferably 1, 500 ~
When it has a number average molecular weight of 5,000, it has an additional advantage that the solution viscosity and the tackiness can be easily balanced.

When the second polymer portion of the thermoplastic addition polymer or the low glass transition point type polymer portion formed by the second α, β-unsaturated monomer is, for example, 1,000 to 20,000,
When it has a number average molecular weight of 00, preferably 3,000 to 15,000, it has an additional advantage that it is easy to balance solution viscosity and adhesive properties. As a method of dissolving and / or dispersing a thermoplastic addition polymer in an organic solvent, for example, it is a common method to coexist during the polymerization step. In some cases, the thermoplastic addition polymer and the organic solvent are mixed. It may be dissolved by heating.

Preferred examples of the pressure-sensitive adhesive composition according to the fourth embodiment are described below. (1) a nonvolatile content of 65 to 75% by weight,
The pressure-sensitive adhesive composition according to the fourth aspect, which has a viscosity at ℃ of 20,000 cps or less. (2) a nonvolatile component concentration of 60 to 80% by weight;
The pressure-sensitive adhesive composition according to the fourth aspect, having a viscosity at 10,000 ° C. of 10,000 cps or less. (3) a nonvolatile content of 65 to 75% by weight;
The pressure-sensitive adhesive composition according to the fourth aspect, having a viscosity at 10,000 ° C. of 10,000 cps or less. (4) In any one of the above (1) to (3), the first
The polymer portion is composed of a high glass transition point type polymer having a glass transition point of 333 K or more, and the second polymer portion is 250
The pressure-sensitive adhesive composition according to the fourth aspect, comprising a low glass transition point type polymer having a glass transition point of less than K. (5) In any one of the above (1) to (3), the first
The polymer portion is composed of a high glass transition type polymer having a glass transition point of 353 K or more, and the second polymer portion is 250
The pressure-sensitive adhesive composition according to the fourth aspect, comprising a low glass transition point type polymer having a glass transition point of less than K. (6) In any one of the above (1) to (3), the first
The polymer portion is composed of a high glass transition point type polymer having a glass transition point of 353 K or more, and the second polymer portion is 230
The pressure-sensitive adhesive composition according to the fourth aspect, comprising a low glass transition point type polymer having a glass transition point of less than K. (7) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer part is 1,000 to 10,000.
0, the number average molecular weight of the second polymer portion is 1,000-2.
The pressure-sensitive adhesive composition according to the fourth aspect, wherein the pressure-sensitive adhesive composition is 0.000. (8) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer portion is 1,500 to 5,000,
The number average molecular weight of the second polymer portion is from 3,000 to 15.0
The pressure-sensitive adhesive composition according to the fourth aspect, wherein the pressure-sensitive adhesive composition is 00. (9) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer part is 1,000 to 10,000.
0, the number average molecular weight of the second polymer portion is 1,000-2.
000, the number average molecular weight of the thermoplastic addition polymer is 1
The pressure-sensitive adhesive composition according to the fourth aspect, wherein the pressure-sensitive adhesive composition is from 000 to 30,000. (10) In any one of the above (4) to (6), the first
The number average molecular weight of the polymer portion is 1,500 to 5,000,
The number average molecular weight of the second polymer portion is from 3,000 to 15.0
00, the number average molecular weight of the thermoplastic addition polymer is 13,00
The pressure-sensitive adhesive composition according to the fourth aspect, which is 0 to 20,000. [Adhesive Composition from Fifth Aspect to Eighth Aspect] According to the fifth aspect, the pressure-sensitive adhesive composition of the present invention comprises a polyvalent mercaptan portion, and a A thermoplastic polymer having a first polymer portion and a second polymer portion, wherein the first polymer portion comprises a high glass transition point type acrylic polymer portion having a glass transition point of 80 ° C. or more; The second polymer portion is made of a low glass transition type acrylic polymer having a glass transition point of -50 to -25 ° C, and the weight ratio of the first polymer portion to the second polymer portion is 20:80 to 35. : 65, wherein the thermoplastic addition polymer is an acrylic hot melt pressure-sensitive adhesive having a number average molecular weight of 30,000 to 60,000.

According to the sixth aspect of the pressure-sensitive adhesive composition of the present invention, the first polymer part has a methyl methacrylate unit of 90 to 90%.
100% by weight and 0 to 10% by weight of other polymerizable monomer units, and the second polymer portion is 0 to 10% by weight of methyl methacrylate unit, 80 to 100% by weight of butyl acrylate unit and other polymerizable units. It is the same as the pressure-sensitive adhesive composition of the fifth embodiment except that it comprises 0 to 10% by weight of a monomer unit.

According to the seventh aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that the polyvalent mercaptan moiety is a residue of a 4- to 6-valent mercaptan according to the fifth or sixth aspect. Same as the pressure-sensitive adhesive composition. According to the eighth aspect, in the pressure-sensitive adhesive composition of the present invention, the first polymer portion has 2,000.
No. 5 except that it has a number average molecular weight of ~ 6,000.
This is the same as the pressure-sensitive adhesive composition according to any one of the embodiments to the seventh embodiment.

Since the polyvalent mercaptan portion has already been described in the first embodiment, the description is omitted here. The number average molecular weight of the thermoplastic addition polymer is 30,0.
00 to 60,000. When the number average molecular weight is below the above range, heat resistance is insufficient and cohesive strength (holding power) during use is reduced. When the number average molecular weight exceeds the above range,
Hot melt viscosity is high and handling properties are poor. In consideration of the balance between sufficiently high heat resistance and sufficiently low hot melt viscosity, the number average molecular weight of the thermoplastic addition polymer is preferably 40,000 to 50,000.

The thermoplastic addition polymer has a molecular weight distribution (Mw
/ Mn) 4 or less. 4 molecular weight distribution
If it is larger than the above, the hot melt viscosity may be high and the workability may be deteriorated when there are many high molecular weight components, and the heat resistance may be low when there are many low molecular weight components. The first polymer portion is made of a high glass transition point type acrylic polymer having a glass transition temperature of 80 ° C. or higher. When the first polymer portion is made of an acrylic polymer having a glass transition temperature of less than 80 ° C., the cohesive strength is reduced and the heat resistance may be reduced.

The first polymer portion has a glass transition temperature of 80.
There is no particular limitation so long as it is composed of a high glass transition point type acrylic polymer having a temperature of at least ℃. Part. The methacrylic acid ester unit is a unit derived from methacrylic acid ester obtained by radical polymerization of methacrylic acid ester, and the other polymerizable monomer units are similarly derived from other polymerizable monomers. It is a unit to do.

The methacrylate unit includes:
For example, monomer units derived from methyl methacrylate, phenyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, dicyclopentadienyl methacrylate, adamantyl methacrylate and the like can be mentioned, and any of them alone, Alternatively, two or more types of the monomer units may be used in combination. Among them, the methacrylate unit has a glass transition temperature of -50 to
A methyl methacrylate unit is preferred in that it has good compatibility with the second polymer portion composed of an acrylic polymer having a low glass transition point at -25 ° C.

Examples of the other polymerizable monomer units include (meth) acrylonitrile, (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and phenylmaleimide. , Butyl maleimide, isopropyl maleimide,
Monomer units derived from cyclohexylmaleimide and the like can be mentioned, either of them alone, or
Two or more monomer units may be used in combination.

The second polymer portion comprises a low glass transition point type acrylic polymer having a glass transition temperature of -50 to -25 ° C. The second polymer part has a glass transition temperature of −50 ° C.
If the acrylic polymer has a glass transition temperature of less than -25 ° C., the adhesiveness becomes insufficient. The second polymer portion is not particularly limited as long as it is composed of a low glass transition point type acrylic polymer having a glass transition temperature of −50 to −25 ° C., for example, an acrylate unit and, if necessary, methacrylic acid. Examples of the polymer portion include one or more acid ester units and / or other polymerizable monomer units. In addition, similarly to the above, the acrylate unit is a monomer unit derived from the acrylate ester.

Examples of the acrylate unit include monomer units derived from ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. Two or more monomer units may be used in combination. Among them, as the acrylate unit, a butyl acrylate unit is preferable because of excellent balance between heat resistance and adhesiveness.

The methacrylic ester unit and / or other polymerizable monomer unit contained in the second polymer portion are all the same as those described for the high glass transition point type acrylic polymer. Is exemplified. As an example of the structure of the first polymer portion, for example, a structure represented by the following formula (1), which is an example containing a methyl methacrylate unit and a (meth) acrylic acid unit, can be given.

[0099]

Embedded image

(In the formula, R is a hydrogen atom or a methyl group. L is a positive number and m is 0 or a positive number.) As an example of the structure of the second polymer portion, for example, ,
Examples include a compound represented by the following formula (2), which is an example containing a methyl methacrylate unit, a (meth) acrylic acid unit, and a butyl acrylate unit.

[0101]

Embedded image

Wherein R is a hydrogen atom or a methyl group; n is a positive number;
Or it is a positive number. The above-mentioned 1st polymer part is a methyl methacrylate unit 90-1.
00% by weight and 0 to 10% by weight of other polymerizable monomer units
Wherein the second polymer portion comprises 0 to 10% by weight of methyl methacrylate units and 80 to 100% of butyl acrylate units.
It is preferred that the acrylic hot-melt pressure-sensitive adhesive has good heat resistance, tackiness and weather resistance when the content is from 0 to 10% by weight and other polymerizable monomer units from 0 to 10% by weight. In addition, it is preferable because both hot melt workability and heat resistance, which are originally incompatible with each other, are excellent. When the other polymerizable monomer unit is a (meth) acrylic acid unit and / or a 2-hydroxyethyl (meth) acrylate unit, a carboxyl group and / or a hydroxyl group can be introduced into the thermoplastic addition polymer. This is preferable because the hot melt workability of the acrylic hot melt pressure-sensitive adhesive is maintained and the heat resistance is improved. In particular, a 2-hydroxyethyl (meth) acrylate unit is preferable because the balance between tackiness and heat resistance is excellent.

When the pressure-sensitive adhesive composition of the present invention is an acrylic hot-melt pressure-sensitive adhesive, the thermoplastic addition polymer having a methyl methacrylate unit has higher transparency and physical properties of the pressure-sensitive adhesive substance than those containing a styrene unit. It will be excellent. Furthermore, when it has a (meth) acrylic acid unit and / or a 2-hydroxyethyl (meth) acrylate unit, the adhesiveness is balanced. In addition, when it has a butyl acrylate unit, the heat resistance is higher than that containing a 2-ethylhexyl acrylate unit, and the adhesiveness is much higher than that containing an ethyl acrylate unit.

The first polymer part and the second polymer part are
Usually, the number average molecular weight is from 2,000 to 45,000, preferably from 3,000 to 40,000. If the number average molecular weight of the polymer portion is below the above range, it may not be possible to introduce properties based on the polymer portion into the thermoplastic addition polymer, and if it exceeds, not only the hot melt viscosity becomes high but also the viscosity during production. And it may be unfavorable in terms of productivity.

When the number average molecular weight of the first polymer portion is 2,000 to 6,000, the acrylic hot melt pressure-sensitive adhesive exhibits sufficient heat resistance and has a low hot melt viscosity. This is preferable because it can be kept low. Further, the handleability is improved. First
The weight ratio [(1) :( 2)] of the polymer portion (1) and the second polymer portion (2) is from 20:80 to 35:65.
If the weight of the first polymer portion is less than the above range, heat resistance is not sufficient. On the other hand, if the weight of the first polymer portion is larger than the above range, the tackiness is reduced, the viscosity becomes high during hot melt, and the workability may be reduced.

When the pressure-sensitive adhesive composition of the present invention is an acrylic hot-melt pressure-sensitive adhesive, the pressure-sensitive adhesive may further contain a tackifier, a wax, and other additives as necessary. Good. Examples of the tackifier include rosin resin, terpene resin, aliphatic petroleum resin, aromatic petroleum resin, cumarone-indene resin, alkylphenol resin, xylene resin and the like. The above resin is used. The tackifier is
It has the function of reducing viscosity during hot melt work and improving cohesive strength during use. The amount of the tackifier used is, for example, 1 to 200 parts by weight, and preferably 10 to 100 parts by weight, based on 100 parts by weight of the thermoplastic addition polymer. If the ratio is below the above range, the viscosity may not be reduced or the cohesive strength may not be improved. If the range is higher than the above range, the tack of the acrylic hot melt pressure-sensitive adhesive may decrease or the cohesive force may become insufficient.

The tackifier is included in the acrylic hot melt pressure-sensitive adhesive by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by the production method described below. Before or after removing the volatile components from the reaction mixture, a tackifier may be mixed to obtain an acrylic hot melt pressure-sensitive adhesive. Examples of the wax include a natural wax, a paraffin wax, a polypropylene wax, a polyethylene wax, and a polymer of a (meth) acrylate having a saturated alkyl group having 18 or more carbon atoms. Use wax. Wax has a viscosity lowering effect during hot melt operation. The amount of the wax used is, for example, 5 to 50 parts by weight, and preferably 10 to 30 parts by weight, based on 100 parts by weight of the thermoplastic addition polymer. If the ratio is below the above range, the viscosity may not be reduced or the cohesive strength may not be improved. If the range is higher than the above range, the tack of the acrylic hot melt pressure-sensitive adhesive may decrease or the cohesive force may become insufficient.

The wax is included in the acrylic hot-melt pressure-sensitive adhesive by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by a production method described below, for example. Before or after removing volatile components from the reaction mixture, a wax may be mixed to obtain an acrylic hot melt pressure-sensitive adhesive. As other additives, for example, a compound which becomes a plasticizer of a (meth) acrylate polymer such as phthalic acid ester and adipic acid ester; a filler such as silica powder and titanium oxide; a dithiocarbamate;
It is at least one compound selected from the group consisting of antioxidants such as phenol compounds. The amounts of these additives include, for example, the amounts employed in conventional acrylic hot melt pressure-sensitive adhesives.

The other additives are contained in the acrylic hot-melt pressure-sensitive adhesive, for example, by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by the production method described below. Before or after removing volatile components from the reaction mixture, other additives may be mixed to obtain an acrylic hot melt pressure-sensitive adhesive. Preferred examples of the pressure-sensitive adhesive composition according to the fifth aspect of the present invention are described below. (1) The number average molecular weight of the first polymer portion is from 2,000 to
45,000, the number average molecular weight of the second polymer portion is 2,000.
The pressure-sensitive adhesive composition according to the fifth embodiment, wherein the pressure-sensitive adhesive composition is from 00 to 45,000. (2) The number average molecular weight of the first polymer portion is from 3,000 to
40,000, the number average molecular weight of the second polymer part is 3.0
The pressure-sensitive adhesive composition according to the fifth aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 40,000. (3) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the fifth aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 50,000. (4) In any one of the above (1) and (2), the number average molecular weight of the thermoplastic addition polymer is 40,000 to 50,
000, the pressure-sensitive adhesive composition according to the fifth aspect. (5) The pressure-sensitive adhesive composition according to the fifth aspect, in any one of the above (1) to (4), wherein the polyvalent mercaptan portion is a residue of a trivalent to hexavalent mercaptan. (6) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the fifth aspect, which is 4 or less. (7) The pressure-sensitive adhesive composition according to the fifth aspect, wherein in any one of the above (1) to (5), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

The thermoplastic addition polymer according to the fifth embodiment is produced, for example, by the method for producing a thermoplastic addition polymer according to the ninth embodiment. Preferred examples of the pressure-sensitive adhesive composition according to the sixth aspect of the present invention are described below. (1) The number average molecular weight of the first polymer portion is from 2,000 to
45,000, the number average molecular weight of the second polymer portion is 2,000.
The pressure-sensitive adhesive composition according to the sixth aspect, wherein the pressure-sensitive adhesive composition is from 00 to 45,000. (2) The number average molecular weight of the first polymer portion is from 3,000 to
40,000, the number average molecular weight of the second polymer part is 3.0
The pressure-sensitive adhesive composition according to the sixth aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 40,000. (3) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the sixth aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 50,000. (4) In any one of the above (1) and (2), the number average molecular weight of the thermoplastic addition polymer is 40,000 to 50,
000, the pressure-sensitive adhesive composition according to the sixth aspect. (5) The pressure-sensitive adhesive composition according to the sixth aspect, wherein in any one of the above (1) to (4), the polyvalent mercaptan portion is a residue of a trivalent to hexavalent mercaptan. (6) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the sixth aspect, which is 4 or less. (7) The pressure-sensitive adhesive composition according to the sixth aspect, wherein in any one of the above (1) to (5), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

The thermoplastic addition polymer according to the sixth embodiment is produced, for example, by the method for producing a thermoplastic addition polymer according to the tenth embodiment. Preferred examples of the pressure-sensitive adhesive composition according to the seventh aspect of the present invention are described below. (1) The number average molecular weight of the first polymer portion is from 2,000 to
45,000, the number average molecular weight of the second polymer portion is 2,000.
The pressure-sensitive adhesive composition according to the seventh aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 45,000. (2) The number average molecular weight of the first polymer portion is from 3,000 to
40,000, the number average molecular weight of the second polymer part is 3.0
The pressure-sensitive adhesive composition according to the seventh aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 40,000. (3) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the seventh aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 50,000. (4) In any one of the above (1) and (2), the number average molecular weight of the thermoplastic addition polymer is 40,000 to 50,
000. The pressure-sensitive adhesive composition according to the seventh aspect, wherein (5) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the seventh aspect, which is 4 or less. (6) The pressure-sensitive adhesive composition according to the seventh aspect, wherein in any one of the above (1) to (4), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

The thermoplastic addition polymer according to the seventh aspect is produced, for example, by the method for producing a thermoplastic addition polymer according to the eleventh aspect. Preferred examples of the pressure-sensitive adhesive composition according to the eighth aspect of the present invention are described below. (1) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the eighth aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 50,000. (2) The pressure-sensitive adhesive composition according to the eighth aspect, wherein the polyvalent mercaptan moiety is a residue of a trivalent to hexavalent mercaptan. (3) The pressure-sensitive adhesive composition according to the eighth aspect, wherein in (1), the polyvalent mercaptan portion is a residue of a trivalent to hexavalent mercaptan. (4) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the eighth aspect, which is 4 or less. (5) The pressure-sensitive adhesive composition according to the eighth aspect, wherein in any one of the above (1) to (3), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

The thermoplastic addition polymer according to the eighth embodiment is produced, for example, by the method for producing a thermoplastic addition polymer according to the twelfth embodiment. [Adhesive composition from ninth aspect to twelfth aspect] According to the ninth aspect, the pressure-sensitive adhesive composition according to the ninth aspect includes a preparation step, a first polymerization step, an addition step, a second polymerization step, An acrylic hot-melt pressure-sensitive adhesive containing a thermoplastic addition polymer produced by a production method containing: The preparation step, the first polymerization step, the addition step, and the second polymerization step will be described later.

According to the tenth aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that the first α, β-unsaturated monomer is 90 to 100% by weight of methyl methacrylate and the other polymerizable monomer 0 ~ 1
0% by weight, and the α, β-unsaturated monomer in the second mixture contains 0 to 10% by weight of methyl methacrylate, 80 to 100% by weight of butyl acrylate and 0 to 1% of another polymerizable monomer.
The pressure-sensitive adhesive composition of the ninth embodiment is the same except that the pressure-sensitive adhesive composition comprises 0% by weight.

According to the eleventh aspect, the pressure-sensitive adhesive composition according to the ninth or tenth aspect is the same as the pressure-sensitive adhesive composition according to the eleventh aspect, except that the polyvalent mercaptan is a 4- to hexavalent mercaptan. Is the same as The pressure-sensitive adhesive composition of the present invention comprises:
According to the second aspect, except that the high glass transition point type acrylic polymer obtained in the first polymerization step has a number average molecular weight of 2,000 to 6,000, the ninth aspect to the eleventh aspect
This is the same as any of the pressure-sensitive adhesive compositions up to the embodiment.

In the preparation step, a first mixture containing a polyvalent mercaptan and a first α, β-unsaturated monomer capable of forming a high glass transition point type polymer having a glass transition point of 80 ° C. or higher is prepared. This is the step of preparing. As polyvalent mercaptan,
The polyvalent mercaptan described in the pressure-sensitive adhesive compositions of the fifth to eighth aspects can be used as it is, and the same applies to preferred ones. Examples of the first α, β-unsaturated monomer serving as the first polymer portion include, for example, methacrylic acid ester described in the pressure-sensitive adhesive composition of the fifth to eighth embodiments, Accordingly, other polymerizable monomers can be used, and the same applies to preferable ones.

The first mixture is the first polymer which is the first polymer part.
Contains 0.5 to 5.0 parts by weight of a polyvalent mercaptan with respect to 100 parts by weight of the α, β-unsaturated monomer. When the amount of the polyvalent mercaptan is out of the range, the number average molecular weight of the first polymer portion and the second polymer portion is from 2,000 to
The number may fall outside the range of 45,000, or the number average molecular weight of the thermoplastic addition polymer may fall outside the range of 30,000 to 60,000. In consideration of this point, the amount of the polyvalent mercaptan is more preferably from 1.0 to 3.0 parts by weight.

The first mixture may further contain a medium in which the polyvalent mercaptan and the first α, β-unsaturated monomer are dissolved and / or dispersed. The medium may be any medium in which the raw material and the obtained polymer are soluble. The amount of medium depends on the amount of the first α, β-unsaturated monomer and the second α, β
-For example, 0 to 20 with respect to the total amount with the unsaturated monomer
0% by weight, preferably 0 to 100% by weight. If the ratio exceeds the above range, the polymerization rate is lowered and the cost in terms of solid content is increased, which is not industrially preferable. Examples of the medium include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and pentane; Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone are exemplified. The organic solvent may be a single solvent or a mixed solvent.

In the first polymerization step, starting from the mercapto group of the polyvalent mercaptan, 15 unreacted mercapto groups are added.
This is a step of obtaining a reaction mixture by performing radical polymerization of the first mixture so as to leave about 85 mol%. The radical polymerization can be carried out by a general radical polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. In order to obtain an inexpensive polymer, a bulk polymerization method containing no extra volatile components is preferred.

The polymerization temperature in the first polymerization step is from 30 to
The temperature is preferably 200 ° C, more preferably 100 to 150 ° C, at which stable bulk polymerization can be performed without using a polymerization initiator. In the first polymerization step, a conventional radical polymerization initiator (for example, 2,2′-azobisisobutyronitrile,
2'-azobiscyclohexanecarbonitrile, 2,
An azo-based polymerization initiator such as 2'-azobis (2-methylbutyronitrile); a peroxide-based polymerization initiator such as benzoyl peroxide; etc. can be used. / 3 or less, preferably 1/10 or less,
More preferably not used. If the polymerization initiator is used in a larger amount than the above ratio, the first polymer extended from the polyvalent mercaptan may be used.
In addition to the polymer portion, a large amount of polymer extending from the polymerization initiator is generated, and the efficiency of forming a thermoplastic addition polymer having a star block structure is reduced.

In the first polymerization step, it is necessary to carry out the radical polymerization so as to leave the unreacted mercapto group at 15 to 85 mol% starting from the mercapto group of the polyvalent mercaptan. In each molecule of the polyvalent mercaptan, a product is obtained in which a carbon atom at one end of the carbon chain of the first polymer moiety is bonded to one or more sulfur residues of the mercapto group. This product has unreacted mercapto groups. In order to efficiently bind one end of the polymer portion to the sulfur residue, it is preferable not to add an unnecessary polymerization initiator to the polymerization system.

In the first polymerization step, it is necessary to carry out the polymerization so as to leave 15 to 85 mol% of unreacted mercapto groups. Therefore, it is preferable to appropriately add a polyvalent mercaptan during the first polymerization step. When less than 15 mol% of unreacted mercapto groups remain, in the second polymerization step, the second α, β-unsaturated monomer added in the addition step becomes unreacted in the first polymerization step. May not react efficiently with the mercapto group of the above, and the yield of the thermoplastic addition polymer may decrease. Further, even if more than 85 mol% of unreacted mercapto groups remain, the yield of the thermoplastic addition polymer may be reduced.

In the first polymerization step, radical polymerization of the first α, β-unsaturated monomer is carried out in the presence of a polyvalent mercaptan. -Enter the step of adding the unsaturated monomer. After the first polymerization step, the remaining monomer can be volatilized and removed. If the degree of polymerization in the first polymerization step is less than 70%, the glass transition point (Tg) of the second polymer portion becomes higher than -25 ° C, and the tackiness (ball tack) of the obtained thermoplastic addition polymer ) May not be enough. However, when the remaining monomer is volatilized and removed after the first polymerization step, the polymerization rate may be less than 70%, but a step of volatilizing and removing the polymer is required, so that the production efficiency is reduced. The conversion in the first polymerization step is 9
If it exceeds 0%, unreacted mercapto groups may be less than 15 mol% in the first polymerization step.

In the addition step, a second glass-transition type polymer having a glass transition point of -50 to -25 ° C can be produced.
Is a step of obtaining a second mixture by adding the α, β-unsaturated monomer to the reaction mixture. The second mixture contains a monomer that forms a second polymer moiety upon radical polymerization. As the second α, β-unsaturated monomer, for example,
Acrylic esters and, if necessary, methacrylic esters and / or other polymerizable monomers described in the pressure-sensitive adhesive compositions of the fifth to eighth aspects can be mentioned. The same applies to

In the addition step, a method of adding another monomer at a time or a method of gradually adding another monomer can be adopted. The second polymerization step is a step of radically polymerizing the second mixture such that the unreacted mercapto group is reduced to 2 mol% or less starting from the unreacted mercapto group. The conditions (temperature, time, raw material ratio, etc.) and method of polymerization in the second polymerization step can be the same as those described in the first polymerization step.

In the second polymerization step, radical polymerization is carried out with a monomer having a composition different from the monomer used in the previous radical polymerization in the presence of the product of the previously performed radical polymerization. If necessary, unreacted monomer components may be removed from the reaction mixture containing the product of the previously performed radical polymerization, or the unreacted monomer components may be left without being removed. It may be used for the radical polymerization performed next. Subsequent radical polymerization is performed starting from all or a part of the remaining mercapto groups in the polyvalent mercaptan. A product is obtained in which one end of the second polymer portion is bonded to the sulfur residue of the mercapto group serving as the starting point. This product may have an unreacted mercapto group, but it is necessary to polymerize so that the unreacted mercapto group after the second polymerization step is 2% or less.

When the unreacted mercapto group after the second polymerization step exceeds 2%, the yield of the thermoplastic addition polymer decreases,
The odor peculiar to mercaptan remains. Further, since the mercapto group may become a crosslinking point and cause gelation, the thermal stability when the obtained thermoplastic addition polymer is used as an acrylic hot melt pressure-sensitive adhesive decreases. When the thermoplastic addition polymer obtained in the second polymerization step does not contain a volatile component such as a solvent or a residual monomer, it can be used as it is as an acrylic hot melt adhesive. When the reaction mixture contains a volatile component, an acrylic hot melt pressure-sensitive adhesive is obtained by removing the volatile component using a device such as a twin screw extruder or a thin film evaporator.

When the pressure-sensitive adhesive composition of the present invention is an acrylic hot melt pressure-sensitive adhesive, the pressure-sensitive adhesive may further contain a tackifier, a wax, other additives, and the like, if necessary. Good. The types, amounts, addition methods, and the like of the tackifier, wax, and other additives have been described in the pressure-sensitive adhesive compositions from the fifth embodiment to the eighth embodiment, and a description thereof will not be repeated.

Preferred examples of the pressure-sensitive adhesive composition according to the ninth embodiment of the present invention are described below. (1) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the ninth aspect, comprising 00 parts by weight and 0.5 to 5.0 parts by weight of a polyvalent mercaptan. (2) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the ninth aspect, comprising 00 parts by weight and 1.0 to 3.0 parts by weight of a polyvalent mercaptan. (3) The pressure-sensitive adhesive composition according to the ninth aspect, wherein the first mixture further contains an organic solvent. (4) In any one of the above (1) and (2), the first
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the mixture further contains an organic solvent. (5) The pressure-sensitive adhesive composition according to the ninth aspect, wherein the polyvalent mercaptan is a trivalent to hexavalent mercaptan. (6) The pressure-sensitive adhesive composition according to the ninth aspect, wherein in any one of the above (1) to (4), the polyvalent mercaptan is a trivalent to hexavalent mercaptan. (7) The radical polymerization in the first polymerization step is carried out at a polymerization rate of 70 to
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the pressure-sensitive adhesive composition is adjusted to 90%. (8) In any one of the above (1) to (6), the first
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the radical polymerization in the polymerization step is performed so as to have a polymerization rate of 70 to 90%. (9) The pressure-sensitive adhesive composition according to the ninth aspect, wherein the polymer formed by the radical polymerization in the first polymerization step has a number average molecular weight of 2,000 to 45,000. (10) In any one of the above (1) to (8), the first
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the polymer formed by radical polymerization in the polymerization step has a number average molecular weight of 2,000 to 45,000. (11) The amount of the second α, β-unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the ninth aspect. (12) In the above (1) to (10), the second α, β-
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the amount of the unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. . (13) The pressure-sensitive adhesive composition according to the ninth aspect, wherein the second mixture further contains an organic solvent. (14) In any one of the above (1) to (12), the second
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the mixture further contains an organic solvent. (15) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the ninth aspect, wherein the pressure-sensitive adhesive composition has a thickness of from 00 to 50,000. (16) In any one of the above (1) to (14), the thermoplastic addition polymer has a number average molecular weight of 40,000 to 50,
000, the pressure-sensitive adhesive composition according to the ninth aspect. (17) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the ninth aspect, which is 4 or less. (18) The pressure-sensitive adhesive composition according to the ninth aspect, wherein in any one of the above (1) to (16), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

Preferred examples of the pressure-sensitive adhesive composition according to the tenth aspect of the present invention are described below. (1) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the tenth aspect, comprising 00 parts by weight and 0.5 to 5.0 parts by weight of a polyvalent mercaptan. (2) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the tenth aspect, comprising 00 parts by weight and 1.0 to 3.0 parts by weight of a polyvalent mercaptan. (3) The pressure-sensitive adhesive composition according to the tenth aspect, wherein the first mixture further contains an organic solvent. (4) In any one of the above (1) and (2), the first
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the mixture further contains an organic solvent. (5) The pressure-sensitive adhesive composition according to the tenth aspect, wherein the polyvalent mercaptan is a trivalent to hexavalent mercaptan. (6) In any one of the above (1) to (4), the polyvalent mercaptan may be a trivalent to hexavalent mercaptan,
The pressure-sensitive adhesive composition according to the embodiment. (7) The radical polymerization in the first polymerization step is carried out at a polymerization rate of 70 to
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the pressure-sensitive adhesive composition is adjusted to 90%. (8) In any one of the above (1) to (6), the first
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the radical polymerization in the polymerization step is performed so that the degree of polymerization is 70 to 90%. (9) The pressure-sensitive adhesive composition according to the tenth aspect, wherein the polymer formed by the radical polymerization in the first polymerization step has a number average molecular weight of 2,000 to 45,000. (10) In any one of the above (1) to (8), the first
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the polymer formed by radical polymerization in the polymerization step has a number average molecular weight of 2,000 to 45,000. (11) The amount of the second α, β-unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the tenth aspect. (12) In the above (1) to (10), the second α, β-
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the amount of the unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. . (13) The pressure-sensitive adhesive composition according to the tenth aspect, wherein the second mixture further contains an organic solvent. (14) In any one of the above (1) to (12), the second
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the mixture further contains an organic solvent. (15) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the tenth aspect, wherein the pressure-sensitive adhesive composition has a value of from 00 to 50,000. (16) In any one of the above (1) to (14), the thermoplastic addition polymer has a number average molecular weight of 40,000 to 50,
000, the pressure-sensitive adhesive composition according to the tenth aspect. (17) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the tenth aspect, which is 4 or less. (18) The pressure-sensitive adhesive composition according to the tenth aspect, wherein in any one of the above (1) to (16), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

Preferred examples of the pressure-sensitive adhesive composition according to the eleventh aspect of the present invention are described below. (1) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the eleventh aspect, comprising 00 parts by weight and 0.5 to 5.0 parts by weight of a polyvalent mercaptan. (2) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the eleventh aspect, comprising 00 parts by weight and 1.0 to 3.0 parts by weight of a polyvalent mercaptan. (3) The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the first mixture further contains an organic solvent. (4) In any one of the above (1) and (2), the first
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the mixture further contains an organic solvent. (5) The radical polymerization in the first polymerization step is carried out at a polymerization rate of 70 to
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the pressure-sensitive adhesive composition is adjusted to 90%. (6) In any one of the above (1) to (4), the first
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the radical polymerization in the polymerization step is performed so as to have a polymerization rate of 70 to 90%. (7) The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the polymer formed by the radical polymerization in the first polymerization step has a number average molecular weight of 2,000 to 45,000. (8) In any one of the above (1) to (6), the first
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the polymer formed by the radical polymerization in the polymerization step has a number average molecular weight of 2,000 to 45,000. (9) The amount of the second α, β-unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the eleventh aspect. (10) In the above (1) to (8), the second α, β-
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the amount of the unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. . (11) The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the second mixture further contains an organic solvent. (12) In any one of the above (1) to (10), the second
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the mixture further contains an organic solvent. (13) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the eleventh aspect, wherein the pressure-sensitive adhesive composition has a value of 00 to 50,000. (14) In any one of the above (1) to (12), the number average molecular weight of the thermoplastic addition polymer is from 40,000 to 50,
000, the pressure-sensitive adhesive composition according to the eleventh aspect. (15) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the eleventh aspect, which is 4 or less. (16) The pressure-sensitive adhesive composition according to the eleventh aspect, wherein in any one of the above (1) to (14), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less.

Preferred examples of the pressure-sensitive adhesive composition according to the twelfth aspect of the present invention are described below. (1) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the twelfth aspect, comprising 00 parts by weight and 0.5 to 5.0 parts by weight of a polyvalent mercaptan. (2) The first mixture comprises the first α, β-unsaturated monomer 1
The pressure-sensitive adhesive composition according to the twelfth aspect, comprising 00 parts by weight and 1.0 to 3.0 parts by weight of a polyvalent mercaptan. (3) The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the first mixture further contains an organic solvent. (4) In any one of the above (1) and (2), the first
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the mixture further contains an organic solvent. (5) The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the polyvalent mercaptan is a trivalent to hexavalent mercaptan. (6) In any one of the above (1) to (4), the polyvalent mercaptan may be a trivalent to hexavalent mercaptan,
The pressure-sensitive adhesive composition according to the embodiment. (7) The radical polymerization in the first polymerization step is carried out at a polymerization rate of 70 to
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the pressure-sensitive adhesive composition is adjusted to 90%. (8) In any one of the above (1) to (6), the first
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the radical polymerization in the polymerization step is performed so as to have a polymerization rate of 70 to 90%. (9) The amount of the second α, β-unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. The pressure-sensitive adhesive composition according to the twelfth aspect. (10) In the above (1) to (8), the second α, β-
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the amount of the unsaturated monomer is 5 to 2,000 parts by weight based on 100 parts by weight of the polymer formed from the first α, β-unsaturated monomer. . (11) The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the second mixture further contains an organic solvent. (12) In any one of the above (1) to (10), the second
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the mixture further contains an organic solvent. (13) The number average molecular weight of the thermoplastic addition polymer is 40,0
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the pressure-sensitive adhesive composition has a value of 00 to 50,000. (14) In any one of the above (1) to (12), the number average molecular weight of the thermoplastic addition polymer is from 40,000 to 50,
The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the composition is 000. (15) Molecular weight distribution of thermoplastic addition polymer (Mw / M
n) The pressure-sensitive adhesive composition according to the twelfth aspect, wherein the composition is 4 or less. (16) The pressure-sensitive adhesive composition according to the twelfth aspect, wherein in any one of the above (1) to (14), the molecular weight distribution (Mw / Mn) of the thermoplastic addition polymer is 4 or less. [Other embodiments of the pressure-sensitive adhesive composition] Other embodiments of the pressure-sensitive adhesive composition of the present invention will be described below.

The pressure-sensitive adhesive composition of the present invention has another embodiment A
Has a polyvalent mercaptan portion and a plurality of polymer portions having two or more different compositions radially extending from the polyvalent mercaptan portion, and having a molecular weight of 10,000 to 200,0.
It is a hot melt resin composition containing a thermoplastic addition polymer having a number average molecular weight of 00. The pressure-sensitive adhesive composition of the present invention is characterized in that, according to the other aspect B, the polymer composition according to the aspect A except that the plurality of polymer portions have a composition that is continuously changed in the entire aggregate of the thermoplastic addition polymer. Is the same as that of the hot melt resin composition.

The pressure-sensitive adhesive composition of the present invention is characterized in that the other embodiment C
The thermoplastic addition polymer has a number average molecular weight of 10,000 to 200,000, has only one glass transition temperature peak having a width of 50 ° C. or more, and has a parallel light transmittance of 85% or more. It is a hot melt resin composition containing. According to another aspect D, the pressure-sensitive adhesive composition of the present invention is characterized in that the thermoplastic addition polymer has a carboxyl group-containing α, β-
Except that it is composed of an unsaturated monomer unit and a (meth) acrylate monomer unit, it is the same as the hot melt resin composition of any one of Embodiments A to C.

The pressure-sensitive adhesive composition according to the present invention is characterized in that it has another embodiment E
According to the method, a preparing step of preparing a mixture containing a first α, β-unsaturated monomer and a polyvalent mercaptan, and the mixture is different from the first α, β-unsaturated monomer An adding step of adding a second α, β-unsaturated monomer having a composition; and a first α, β starting from a mercapto group of a polyvalent mercaptan.
a polymerization step of performing radical polymerization of the β-unsaturated monomer and the second α, β-unsaturated monomer, and a hot melt resin composition containing the thermoplastic addition polymer obtained by the production method. is there.

The pressure-sensitive adhesive composition according to the present invention is characterized in that the other embodiment F
According to the method, the production method comprises the steps of: providing a first step starting from a mercapto group of a polyvalent mercaptan between a preparation step and an addition step;
This is the same as the hot melt resin composition of Embodiment E, except that the method further comprises a prepolymerization step of performing radical polymerization of the α, β-unsaturated monomer. According to another embodiment G, the pressure-sensitive adhesive composition of the present invention comprises an α, β-unsaturated monomer comprising a carboxyl group-containing α, β-unsaturated monomer and a (meth) acrylate monomer. And a polyvalent mercaptan, and a polymerization step of radical polymerization of an α, β-unsaturated monomer starting from a mercapto group of the polyvalent mercaptan. It is a hot melt resin composition containing a thermoplastic addition polymer having a structure.

The pressure-sensitive adhesive composition of the present invention is characterized in that the other embodiment H
According to this, the composition is the same as the hot melt resin composition of any one of the embodiments A to G, except that the composition further includes a metal ion source. According to the other aspect I, the pressure-sensitive adhesive composition of the present invention is the same as the hot melt resin composition of the aspect H except that the composition further includes a phosphate ester.

The pressure-sensitive adhesive composition according to the present invention is characterized in that the other embodiment J
According to the above, a (meth) acrylic thermoplastic addition polymer containing a carboxyl group-containing α, β-unsaturated monomer unit and a (meth) acrylate monomer unit, a metal ion source, and a phosphate ester And a hot melt resin composition comprising: According to the other aspect K, the pressure-sensitive adhesive composition of the present invention is the same as the hot melt resin composition of any of the aspects A to J except that the composition further includes a tackifier resin.

The pressure-sensitive adhesive composition according to the present invention is characterized in that the pressure-sensitive adhesive composition according to another embodiment L
According to the above, the composition is the same as the hot melt resin composition of any one of Embodiments A to K except that the composition further contains a wax. The actions of the hot melt resin compositions of the embodiments A to L are as follows. The hot melt resin composition of Embodiment A has a polyvalent mercaptan portion, and a plurality of polymer portions having two or more different compositions radially extending from the polyvalent mercaptan portion, and having a molecular weight of 10,000 to 200,000.
Including a thermoplastic addition polymer having a number average molecular weight of, the polymer portion has a branched structure (star-shaped block structure) that extends radially from the polyvalent mercaptan portion, so that the same molecular weight Compared to linear polymers, block polymers, and graft polymers, they have low viscosity at the time of hot melt and have good workability. It has a larger cohesive force than a conventionally known polymer for a hot melt resin, and is therefore excellent in heat resistance.

The hot melt resin composition of Embodiment B is characterized in that, in Embodiment A, the plurality of polymer parts further have a composition which is continuously changed in the whole aggregate of the thermoplastic addition polymer. Since the addition polymer has a star-shaped block structure with a gradient composition, the entanglement between molecules is larger at the use temperature and has a larger cohesive force than a conventionally known polymer for a hot melt resin, and is transparent. It has the further advantage of being.

The hot melt resin composition of Embodiment C is
Having a number average molecular weight of 0000 to 200,000,
By containing a thermoplastic addition polymer having only one glass transition temperature peak having a width of 0 ° C. or more and a parallel light transmittance of 85% or more, a linear polymer, a block polymer, and a graft having the same molecular weight can be obtained. Compared to polymers, it has low viscosity during hot melt and has good workability, and has a large cohesion force than conventional polymers for hot melt resins with large inter-molecular entanglement at operating temperature, and thus has excellent heat resistance And
It is transparent.

The hot melt resin composition of Embodiment D is characterized in that, in any one of Embodiments A to C, the thermoplastic addition polymer comprises a carboxyl group-containing α, β-unsaturated monomer unit and a (meth) acrylate ester. Since it is a (meth) acrylic resin having a carboxyl group by being composed of monomer units, it can be used in any one of the hot melt resin compositions according to aspects A to C at an operating temperature. It has the further advantage of being more entangled and more excellent in heat resistance and excellent in weather resistance.

The hot melt resin composition of the embodiment E comprises the first
A preparing step of preparing a mixture containing an α, β-unsaturated monomer and a polyvalent mercaptan;
An addition step of adding a second α, β-unsaturated monomer having a composition different from that of the α, β-unsaturated monomer, and a first α, β-unsaturated monomer starting from the mercapto group of the polyvalent mercaptan. A polymerization step of performing radical polymerization of a mixture of an unsaturated monomer and an added second α, β-unsaturated monomer; and a thermoplastic addition polymer obtained by a production method,
Since the thermoplastic addition polymer has a star-shaped block structure, it has lower viscosity at hot melt compared to linear polymers, block polymers, and graft polymers of the same molecular weight, and has good workability. It has large intermolecular entanglement and has a larger cohesive force than a conventionally known polymer for a hot melt resin, and thus has excellent heat resistance. In particular, the second α, β-
When performing radical polymerization while gradually adding unsaturated monomers, since the thermoplastic addition polymer has a gradient composition,
It also has the advantage of being more heat-resistant and transparent.

The hot melt resin composition of Embodiment F is characterized in that, in Embodiment E, the production method comprises the steps of:
By further including a prepolymerization step of performing radical polymerization of α, β-unsaturated monomers, there is an additional advantage that heat resistance and hot melt workability can be easily achieved. The hot melt resin composition of Embodiment G contains an α, β-unsaturated monomer comprising a carboxyl group-containing α, β-unsaturated monomer and a (meth) acrylate monomer and a polyvalent mercaptan. A thermoplastic addition polymer having a branched structure obtained by a production method including a preparation step of preparing a mixture, and a polymerization step of performing radical polymerization of an α, β-unsaturated monomer starting from a mercapto group of a polyvalent mercaptan By containing, since the thermoplastic addition polymer has a star-shaped structure, compared with a linear polymer of the same molecular weight, it has a low viscosity at the time of hot melt and has good workability, and the entanglement between molecules at the use temperature is large. It has greater cohesion than a linear polymer and has excellent heat resistance. Since it is a (meth) acrylate resin, it has excellent weather resistance and is transparent.

In any one of Embodiments A to G, when the hot melt resin composition of Embodiment H further contains a metal ion source, the thermoplastic addition polymer is cross-linked with metal ions, so that the agglomeration at the operating temperature is not possible. The power is greater,
There is an additional advantage that the balance between the cohesive force and the hot melt viscosity is improved. In the hot melt resin composition of Embodiment I, in Embodiment H, when a phosphate ester is further contained, the phosphate ester coordinates to the metal ion, so that the bonding force between the carboxyl group and the metal ion is reduced,
There is an additional advantage that the workability is improved by reducing the hot melt viscosity.

The hot melt resin composition of Embodiment J comprises a (meth) acrylic thermoplastic addition polymer containing a carboxyl group-containing α, β-unsaturated monomer unit and a (meth) acrylate monomer unit. Including a metal ion source and a phosphate, the thermoplastic addition polymer is cross-linked by the metal ion, so that the cohesive force is increased. The bond strength between the metal and the metal ions is reduced, the viscosity of the hot melt is reduced, and the workability is improved.

The hot melt resin composition of Embodiment K according to any one of Embodiments A to J, further comprises a tackifier resin, thereby lowering the hot melt viscosity, increasing the cohesive force, and improving the adhesive strength. This has the advantage that the performance can be further improved. The hot melt resin composition of Aspect L further has an advantage that the hot melt viscosity becomes lower by further containing a wax in any of Aspects A to K. [Hot Melt Resin Composition of Embodiment A] The hot melt resin composition of Embodiment A contains a thermoplastic addition polymer having a polyvalent mercaptan portion and a plurality of polymer portions.

The number average molecular weight of the thermoplastic addition polymer is 1
It is between 000 and 200,000. When the number average molecular weight is below the above range, heat resistance is insufficient and cohesive strength (holding power) during use is reduced. If the number average molecular weight exceeds the above range, the hot melt viscosity is high and the handling property is poor. In consideration of the balance that the heat resistance is sufficiently high and the hot melt viscosity is sufficiently low, the number average molecular weight of the thermoplastic addition polymer is preferably from 50,000 to 150,000.
It is.

The thermoplastic addition polymer has a molecular weight distribution (Mw
/ Mn) 4 or less. 4 molecular weight distribution
If it is larger than the above, the hot melt viscosity may be high and the workability may be deteriorated when there are many high molecular weight components, and the heat resistance may be low when there are many low molecular weight components. Since the polyvalent mercaptan portion has already been described in the first embodiment, the description is omitted here.

The polymer portion usually has a number average molecular weight of
1,000 to 150,000, preferably 3,000 to
100,000. If the number average molecular weight of the polymer portion is below the above range, it may not be possible to introduce properties based on the polymer portion into the thermoplastic addition polymer, and if it exceeds, not only the hot melt viscosity becomes high but also the viscosity during production. And it may be unfavorable in terms of productivity.

The thermoplastic addition polymer has a plurality of polymer portions per polymer. The polymer portion is a portion having a homopolymer or copolymer structure formed by radical polymerization of an α, β-unsaturated monomer. The polymer portion obtained by radical polymerization is more diverse in the type of composition than the polymer portion generated by ionic polymerization such as anionic polymerization, except that the type of monomer used is also capable of radical polymerization. It is not particularly limited, and it may be a copolymer.

The plurality of polymer moieties have two or more different compositions. The difference in the composition is, when derived from a homopolymer, the difference between the monomer units constituting the polymer, and when derived from the copolymer, the difference between the monomer units and / or It is obtained by the difference of the unit ratio. The monomer unit is a monomer unit derived from the α, β-unsaturated monomer described in the description of the hot melt resin composition of Embodiment E.

The combination of polymer portions having different compositions will depend on the performance (or use) required of the thermoplastic addition polymer. Basically, the combination of the polymer portions includes a combination of polymer portions derived from polymers having different glass transition temperatures (Tg). As a combination of polymers having different Tg, for example, a combination of a polymer portion having a Tg of 0 ° C. or less and a polymer portion having a Tg of 20 ° C. or more, preferably a polymer having a Tg of −20 ° C. or less Combination with the polymer portion having a Tg of 50 ° C. or more, more preferably −40 ° C.
Combinations of a polymer portion having the following Tg and a polymer portion having a Tg of 70 ° C. or higher can be given. By selecting these combinations, it is possible to achieve conflicting performances such as heat resistance and tackiness, and adhesive strength and toughness. For example, a hot melt resin composition is used as a pressure-sensitive adhesive (pressure-sensitive adhesive).
When used as a polymer, the polymer portion having a low Tg
The thermoplastic addition polymer is designed to occupy more, more than more, of the high polymer fraction.

When the hot-melt resin composition is used as a hot-melt adhesive, the thermoplastic addition polymer is used so that the polymer portion having a high Tg occupies a larger portion or a larger portion than the polymer portion having a lower Tg. Is designed. Aspect A
The thermoplastic addition polymer of the hot melt resin composition according to (1) is produced, for example, by the method for producing a thermoplastic addition polymer of the hot melt resin composition according to embodiment (E) or (F). [Hot Melt Resin Composition of Embodiment B] The hot melt resin composition of Embodiment B contains a thermoplastic addition polymer having a polyvalent mercaptan portion and a plurality of polymer portions. The thermoplastic addition polymer has a number average molecular weight of 10,000 to 200,000. The plurality of polymer moieties have two or more different compositions, extend radially from the polyvalent mercaptan moiety, and have a composition that varies continuously throughout the aggregate of the thermoplastic addition polymer.

The hot melt resin composition of the embodiment B has a composition in which a plurality of polymer portions in the hot melt resin composition of the embodiment A are continuously changed in the whole aggregate of the thermoplastic addition polymer. Except for this, it is the same as the hot melt resin composition of the embodiment A. The polymer portion is composed of two or more different α, β-unsaturated monomer units. The α, β-unsaturated monomer unit may be selected from α, β mentioned in the description of the hot melt resin composition of Embodiment E described later.
-A monomer unit derived from an unsaturated monomer. The two or more different α, β-unsaturated monomer units are units derived from the first α, β-unsaturated monomer capable of forming the first polymer portion (the first monomer unit). Unit) and a unit (second monomer unit) derived from a second α, β-unsaturated monomer capable of forming a second polymer portion having physical properties different from those of the first polymer portion. ).

Further, the polymer portion has a composition which is continuously changed in the entire polymer aggregate constituting the thermoplastic addition polymer. This is because the polymer portion does not consist of only the first polymer portion and the second polymer portion in the entire assembly, but the composition of the first polymer portion and the second polymer portion. That is, the composition of the united portion has a continuous composition mixed in an arbitrary ratio. The composition of the α, β-unsaturated monomer units is shown in an averaged form for the entire assembly.

The thermoplastic addition polymer of the embodiment B may be a polymer having only a polymer portion having a monomer unit composition in the above-mentioned averaged form, or a polymer having a first polymer portion and a second polymer portion. Exhibiting different physical properties from a mixture of copolymers having a continuous composition in which the composition of the parts is mixed at an arbitrary ratio but having no block structure, and furthermore, a first polymer part and a second polymer part And has physical properties different from those of a so-called block polymer or graft polymer having

The thermoplastic addition polymer of the embodiment B can have various functions by having a polymer portion having a large number of compositions, in view of the entire polymer aggregate constituting the thermoplastic addition polymer. Since many compositions are slightly different as a whole, they take a form in which phase separation hardly occurs. Such a form effectively acts on the expression of a new function.

A large number of compositions means that the polymer portion has a composition composed of continuously changing constituent monomer units as a whole. For example, in a polymer having a wide glass transition point, The upper limit of the glass transition temperature peak is determined from the composition of the monomer unit constituting the polymer portion having the lower limit of the glass transition temperature by a differential scanning calorimeter (DSC) so as to have a typical glass transition point. Has a composition up to the composition of the monomer units constituting the polymer portion having the glass transition point.

A large number of slightly different compositions means that the ratio of a part or all of the constituent monomer units of the polymer portion is continuously changed, and that the α, β-unsaturated monomer in the polymerization system is changed. Obtained by gradually changing the body composition. The reason for gradually changing the monomer composition in the polymerization system is that, for example, the polymerization system containing the first α, β-unsaturated monomer is polymerized before or during polymerization of the polymerization system. 2 can be carried out by gradually adding the α, β-unsaturated monomer.

[0161] In the thermoplastic addition polymer of the embodiment B, it is possible to impart more various performances by combining polymer parts having three or more different compositions. The thermoplastic addition polymer of the hot melt resin composition of the embodiment B can be produced, for example, by a method for producing a thermoplastic addition polymer of the hot melt resin composition of the embodiment E or F, in particular, the first α, β-unsaturation. It is made when a second α, β-unsaturated monomer is gradually added to a mixture containing a monomer and a polyvalent mercaptan while polymerizing. The thermoplastic addition polymer of the hot melt resin composition according to Embodiment B produced by this method contains sulfur atoms in the range of 0.005 to 4% by weight.
If the amount of the sulfur atom is less than the above range, the number average molecular weight may be too large or a thermoplastic addition polymer having a target structure may not be obtained. There is a possibility that physical properties derived from the composition of the above may not be easily exhibited. The amount of the sulfur atom is such that the number average molecular weight of the target thermoplastic addition polymer is 10,000.
0.01 to 2% by weight
Is preferable, and a preferable number average molecular weight is 30,000.
Since it is 0 to 150,000, the range of 0.02 to 1% by weight is more preferable. [Hot melt resin composition of embodiment C] The hot melt resin composition of embodiment C contains a thermoplastic addition polymer. The thermoplastic addition polymer has a number average molecular weight of 10,000 to 200,000, has only one glass transition temperature peak having a width of 50 ° C. or more, and has a parallel light transmittance of 85% or more.

The thermoplastic addition polymer of the embodiment C is one in which the thermoplastic addition polymer of the above embodiment B is specified by physical properties. In embodiment C, the thermoplastic addition polymer preferably has a glass transition temperature peak having a width of 80 ° C or more. In aspect C, the thermoplastic addition polymer preferably comprises
Having a number average molecular weight of 30,000 to 150,000,
It has only one glass transition temperature peak having a width of 80 ° C. or more, and has a parallel light transmittance of 90% or more. As an example of such a thermoplastic addition polymer, the thermoplastic addition polymer according to the above-mentioned embodiment B can be mentioned.

The thermoplastic addition polymer according to the embodiment C contains, for example, two or more different α, β-unsaturated monomer units. Examples of the two or more different α, β-unsaturated monomer units include the first monomer unit and the second monomer unit described in the description of Embodiment B. When the number average molecular weight of the thermoplastic addition polymer falls below the above range, physical properties derived from the composition of the monomer units constituting the polymer become difficult to develop, and when the number average molecular weight exceeds the above range, the viscosity becomes high and handling becomes difficult.

The thermoplastic addition polymer has only one glass transition temperature peak having a width of 50 ° C. or more, preferably 80 ° C. or more. When the width of the glass transition temperature peak falls below the above range, the balance between the heat resistance and the toughness of the polymer becomes poor. The width of the glass transition temperature peak is 8
A temperature of 0 ° C. or higher is preferred in terms of a balance between heat resistance and toughness. In addition, the width of the glass transition temperature peak refers to the peak width by a differential scanning calorimeter (DSC).

The thermoplastic addition polymer has a parallel light transmittance of 85% or more. When the parallel light transmittance is lower than the above range, it indicates that the phase separation state of the polymer is large. A parallel light transmittance of 90% or more is more preferable than 85% for use in applications requiring transparency. The parallel light transmittance is a visible light transmittance measured by a turbidimeter in the thickness direction of a 3 mm-thick flat plate obtained by injection-molding a thermoplastic addition polymer.

The thermoplastic addition polymer of the hot melt resin composition according to the embodiment C can be prepared by, for example, a method for producing a thermoplastic addition polymer of the hot melt resin composition according to the embodiment E or F, particularly, the first α. It is produced when a second α, β-unsaturated monomer is gradually added to a mixture containing .alpha.,. Beta.-unsaturated monomer and polyvalent mercaptan while polymerizing.
The thermoplastic addition polymer of the hot melt resin composition according to Embodiment C produced by this method has a sulfur atom of 0.0
It is contained in the range of 0.5 to 4% by weight. If the amount of the sulfur atom is less than the above range, the number average molecular weight may be too large or a thermoplastic addition polymer having a target structure may not be obtained. There is a possibility that physical properties derived from the composition of the above may not be easily exhibited. The number of sulfur atoms is determined so that the number average molecular weight of the target thermoplastic addition polymer is from 10,000 to 200,000.
Therefore, the number average molecular weight is preferably in the range of from 30,000 to 150,0%.
Since it is 00, the range of 0.02 to 1% by weight is more preferable. [Hot Melt Resin Composition of Embodiment D] The hot melt resin composition of Embodiment D is characterized in that the thermoplastic addition polymer has a carboxyl group-containing α, β-unsaturated monomer unit and a (meth) acrylate monomer unit. The composition is the same as the hot melt resin composition according to any one of the aspects A to C, except that the composition is composed of

The carboxyl group-containing α, β-unsaturated monomer unit is, for example, a monomer unit derived from the carboxyl group-containing α, β-unsaturated monomer described in the later-described embodiment E. The (meth) acrylic acid ester monomer unit is, for example, described in (E) below.
It is a monomer unit derived from an acrylate monomer.

In the hot melt resin composition according to the embodiment D, the thermoplastic addition polymer is, for example, 0.5 to 25% by weight of a carboxyl group-containing α, β-unsaturated monomer unit and (meth) acrylate ester Monomer unit 75 to 99.5
% Of other α, β-unsaturated monomer units copolymerizable with
, And preferably 1 to 10% by weight of a carboxyl group-containing α, β-unsaturated monomer unit and (meth)
90-99% by weight of acrylate monomer units.

The amount of the carboxyl group-containing α, β-unsaturated monomer unit is set within the above range in order to introduce a carboxyl group into the thermoplastic addition polymer. Of the hot melt resin composition may have an adverse effect on the performance such as water resistance. When the amount of the (meth) acrylic acid ester monomer unit is within the above range, the hot melt resin composition has good heat resistance and weather resistance.

The other copolymerizable α, β-unsaturated monomer unit may be, for example, a monomer unit derived from a copolymerizable α, β-unsaturated monomer described in Embodiment E described later. It is. If the amount of the copolymerizable α, β-unsaturated monomer unit exceeds the above range, sufficient weather resistance may not be obtained. The thermoplastic addition polymer of the hot melt resin composition according to the embodiment D is, for example, a method for producing a thermoplastic addition polymer of the hot melt resin composition according to the embodiment E or F, wherein the carboxyl group-containing α, β-non- Α, β- containing saturated monomer and (meth) acrylate monomer
Made when using unsaturated monomers. [Hot Melt Resin Composition of Aspect E] The hot melt resin composition of Aspect E contains a thermoplastic addition polymer obtained by a production method including a preparation step, an addition step, and a polymerization step.

The preparing step is a step of preparing a mixture containing the first α, β-unsaturated monomer and a polyvalent mercaptan. As the first α, β-unsaturated monomer, any monomer can be used as long as it produces a homopolymer or a copolymer by radical polymerization. For example,
(Meth) acrylic acid; an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate,
(Meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and ethoxyethoxyethyl (meth) acrylate; styrene-based polymerizable polymers such as α-methylstyrene, vinyltoluene, and styrene Monomers; vinyl ethers represented by methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, vinyl acetate, etc .; fumaric acid, monoalkyl esters of fumaric acid, dialkyl esters of fumaric acid; maleic acid, monoalkyl esters of maleic acid, maleic acid Dialkyl esters of acids; itaconic acid, monoalkyl esters of itaconic acid,
Dialkyl esters of itaconic acid; half esters of succinic or phthalic anhydride with hydroxyethyl (meth) acrylate; (meth) acrylonitrile, butadiene, isoprene, vinyl chloride, vinylidene chloride,
Examples thereof include vinyl ketone, vinyl pyridine, and vinyl carbazole.
These can be used together.

Since the polyvalent mercaptan has already been described in the first embodiment, the description is omitted here. The mixture prepared in the preparation step contains, for example, 0.01 to 10 parts by weight of a polyvalent mercaptan based on 100 parts by weight of the first α, β-unsaturated monomer. When the amount of the polyvalent mercaptan is out of the above range, the number average molecular weight of the polymer portion is out of the range of 1,000 to 150,000, or the number average molecular weight of the thermoplastic addition polymer is 10,000 to 20.
It may be out of the range of 000. Considering this point, the amount of the polyvalent mercaptan is 0.05 to 5
Parts by weight are more preferred.

The mixture prepared in the preparation step may further contain a medium in which the first α, β-unsaturated monomer and the polyvalent mercaptan are dissolved and / or dispersed. The medium may be any medium in which the monomer and the obtained polymer are soluble. The amount of the medium is, for example, 0 to 200% by weight, preferably 0 to 100% by weight, based on the total amount of the first α, β-unsaturated monomer and the second α, β-unsaturated monomer.
% By weight. If the ratio exceeds the above range, the polymerization rate is lowered and the cost in terms of solid content is increased, which is not industrially preferable. Examples of the medium include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and pentane; Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone are exemplified. The organic solvent may be a single solvent or a mixed solvent.

In the adding step, the mixture containing the first α, β-unsaturated monomer and the polyvalent mercaptan is added to the first α, β-unsaturated monomer.
This is a step of adding a second α, β-unsaturated monomer having a composition different from that of the unsaturated monomer. The second α, β-unsaturated monomer is one which produces a homopolymer or a copolymer by radical polymerization and has a composition different from that of the first α, β-unsaturated monomer. Any monomer can be used. For example, the first α, β-
Examples of the unsaturated monomer can be given,
Any of them can be used alone or in combination of two or more.

When the hot-melt resin composition is used as a pressure-sensitive adhesive (pressure-sensitive adhesive), the hot-melt resin composition is heated so that the polymer portion having a lower Tg occupies a larger portion or a larger portion than the polymer portion having a higher Tg. A plastic addition polymer is designed. When using the hot melt resin composition as a hot melt adhesive, the design of the thermoplastic addition polymer is designed so that the polymer portion having a high Tg occupies a larger portion than the polymer portion having a lower Tg. Done.

The first α, β-unsaturated monomer and the second α, β-unsaturated monomer
The combination with the β-unsaturated monomer is set from the viewpoint of increasing the cohesive force of the thermoplastic addition polymer by introducing a block structure having a polymer portion having a different Tg,
For example, an α, β-unsaturated monomer capable of forming a thermoplastic polymer having a glass transition point of 0 ° C. or lower, and an α, β capable of forming a thermoplastic polymer having a glass transition point of 20 ° C. or higher. -Combinations with unsaturated monomers. From the viewpoint of further improving the cohesive strength of the thermoplastic addition polymer, preferably, an α, β-unsaturated monomer capable of forming a thermoplastic polymer having a glass transition point of −20 ° C. or lower, and 50% A combination with an α, β-unsaturated monomer capable of forming a thermoplastic polymer having a glass transition point of not lower than ℃, more preferably a thermoplastic polymer having a glass transition point of not higher than -40 ℃ Α, β-unsaturated monomer and 7
It is a combination with an α, β-unsaturated monomer capable of producing a thermoplastic polymer having a glass transition point of 0 ° C. or higher.

In this case, one of the first α, β-unsaturated monomer and the second α, β-unsaturated monomer can form a thermoplastic polymer having a low glass transition point. The monomer is not particularly limited as long as the other monomer is capable of producing a thermoplastic polymer having a high glass transition point. As the first α, β-unsaturated monomer and the second α, β-unsaturated monomer, 0.5 to 25% by weight of a carboxyl group-containing α, β-unsaturated monomer and (meth) When the acrylate monomer is used in an amount of 75 to 99.5% by weight, the heat resistance is improved by the carboxyl group introduced into the thermoplastic addition polymer, and the thermoplastic addition polymer is used as a (meth) acrylic resin. The improvement in weather resistance due to the formation of the particles is recognized, which is more preferable.

The carboxyl group-containing α, β-unsaturated monomers include, for example, unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, unsaturated dicarboxylic acids such as itaconic acid, maleic acid and fumaric acid; At least one monomer selected from the group consisting of monoalkyl esters of unsaturated dicarboxylic acids such as acid, maleic acid and fumaric acid, and half esters of succinic anhydride or phthalic anhydride and hydroxyethyl (meth) acrylate It is. If the amount of the carboxyl group-containing α, β-unsaturated monomer is less than the above range, the heat resistance of the hot melt resin composition may be insufficient. There is a risk of adverse effects.

The (meth) acrylic acid ester monomer is, for example, an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms, hydroxyethyl (meth)
From the group consisting of (meth) acrylates represented by acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and ethoxyethoxyethyl (meth) acrylate At least one monomer selected. When the amount of the (meth) acrylic acid ester monomer is within the above range, the heat resistance and weather resistance of the hot melt resin composition are good.

Copolymerizable α, β-unsaturated monomers include carboxyl group-containing α, β-unsaturated monomers and (meth)
It is a monomer copolymerizable with an acrylate monomer. For example, among the α, β-unsaturated monomers exemplified above, a carboxyl group-containing α, β-unsaturated monomer and ( It is a monomer other than the (meth) acrylate monomer. If the amount of the copolymerizable α, β-unsaturated monomer exceeds the above range, sufficient weather resistance may not be obtained.

The amount of the second α, β-unsaturated monomer is
Is in the range of, for example, 5 to 2000 parts by weight based on 100 parts by weight of the polymer formed from the α, β-unsaturated monomer. Outside of this range, the thermoplastic addition polymer may not have the performance derived from the star block structure. Considering this point, the amount of the second α, β-unsaturated monomer is 1
0 to 1000 parts by weight is preferred.

In the addition step, a method of adding the second α, β-unsaturated monomer at a time or a method of gradually adding the second α, β-unsaturated monomer can be adopted. The polymerization step is a step of performing radical polymerization of the first α, β-unsaturated monomer and the second α, β-unsaturated monomer starting from the mercapto group of the polyvalent mercaptan.

The polymerization step can be performed during the addition step or after the addition step. When the polymerization step is performed during the addition step, radical polymerization is performed while gradually adding the second α, β-unsaturated monomer. When the polymerization step is performed after the addition step, between the preparation step and the addition step, a pre-polymerization step in which the first α, β-unsaturated monomer is radically polymerized starting from the mercapto group of the polyvalent mercaptan May be further included.

The radical polymerization can be carried out by a usual radical polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. In order to obtain an inexpensive polymer, a bulk polymerization method containing no extra volatile components is preferred. The polymerization temperature is preferably from 30 to 200 ° C., more preferably from 100 to 1 to allow stable bulk polymerization without using a polymerization initiator.
50 ° C.

In the polymerization step, a conventional radical polymerization initiator (for example, 2,2'-azobisisobutyronitrile,
Azo-based polymerization initiators such as 2,2'-azobiscyclohexanecarbonitrile; peroxide-based polymerization initiators such as benzoyl peroxide) can be used.
It is not more than 1/3, preferably not more than 1/10, more preferably not used, of the polyvalent mercaptan. When the polymerization initiator is used in a larger amount than the above ratio, in addition to the polymer portion extended from the polyvalent mercaptan, a large amount of the polymer extended from the polymerization initiator is generated, and a thermoplastic addition polymer having a star block structure Generation efficiency is reduced.

By the radical polymerization, a product is obtained in which, in each molecule of the polyvalent mercaptan, one or more sulfur residues of a mercapto group are bonded to a carbon atom at one end of the carbon chain of the polymer portion. This product has unreacted mercapto groups. In order to efficiently bind one end of the polymer portion to the sulfur residue, it is preferable not to add an unnecessary polymerization initiator to the polymerization system. The plurality of polymer moieties formed by performing the radical polymerization of the first α, β-unsaturated monomer and the second α, β-unsaturated monomer include:
It has two or more different compositions.

In embodiment E, the second α, β
-When the unsaturated monomer is gradually added, and the polymerization step is performed during the addition step, the thermoplastic part having a polymer part having a so-called gradient composition in which the polymer part continuously changes in composition as a whole. An addition polymer (or a thermoplastic addition polymer of the hot melt resin composition according to the embodiment B or C) is obtained. In this case, as the first α, β-unsaturated monomer and the second α, β-unsaturated monomer, as described above, the first α, β-unsaturated monomer and The second α, β
When the carboxyl group-containing α, β-unsaturated monomer 0.5 to 25% by weight and the (meth) acrylate monomer 75 to 99.5% by weight are used as the unsaturated monomers, A thermoplastic addition polymer of the hot melt resin composition according to Embodiment D is obtained.

When the reaction mixture obtained in the polymerization step contains no volatile components such as a solvent and residual monomers, it can be used as it is as a hot melt resin composition. When the reaction mixture contains a volatile component, a hot melt resin composition is obtained by removing the volatile component using a device such as a twin screw extruder or a thin film evaporator. [Hot Melt Resin Composition of Aspect F] The hot melt resin composition of Aspect F contains a thermoplastic addition polymer obtained by a production method including a preparation step, a prepolymerization step, an addition step, and a polymerization step.

The preparation step is a step of preparing a mixture containing the first α, β-unsaturated monomer and a polyvalent mercaptan, and is as described in Embodiment E. In the prepolymerization step, the first step starts from the mercapto group of the polyvalent mercaptan.
Is a first polymerization step of performing radical polymerization of α, β-unsaturated monomers. As for the polymerization conditions (temperature, time, raw material ratio, etc.) and method, those described in Embodiment E can be employed.

In the prepolymerization step, radical polymerization of the first polymerizable monomer component is carried out in the presence of a polyvalent mercaptan. The process starts with the addition of the monomer. When the addition step is performed after the conversion reaches 50% or more, preferably 80% or more, the polymerization step is performed without removing the remaining first α, β-unsaturated monomer. Even if such is the case, different polymer portions are likely to be generated in the pre-polymerization step and the polymerization step. It is also possible to volatilize off the remaining first α, β-unsaturated monomer after the prepolymerization step to produce different polymer moieties.

In the addition step, a second α, β-unsaturated monomer having a composition different from that of the first α, β-unsaturated monomer is added to the reaction mixture obtained in the prepolymerization step. This is a step of obtaining a second mixture by heating. At that time, a method of adding the second α, β-unsaturated monomer at a time, a method of gradually adding the second α, β-unsaturated monomer, and the like can be adopted. When the polymerization rate in the prepolymerization step is set to 50% or more, and the remaining α, β-unsaturated monomer is volatilized and removed as required, and then the second α, β-unsaturated monomer is added at once, A thermoplastic addition polymer having polymer portions of different compositions is obtained. When the second α, β-unsaturated monomer is gradually added after the polymerization rate in the prepolymerization step is set to 0 to 50%, a so-called gradient in which the composition of the polymer portion continuously changes as a whole is obtained. A thermoplastic addition polymer having a polymer portion having the composition is obtained.

The polymerization step is a second polymerization step in which the α, β-unsaturated monomer contained in the second mixture is subjected to radical polymerization, starting from the mercapto group of the polyvalent mercaptan. As for the polymerization conditions (temperature, time, raw material ratio, etc.) and method, those described in Embodiment E can be employed. In the polymerization step, an α, β-unsaturated monomer having a composition different from that of the α, β-unsaturated monomer used in the previously performed radical polymerization in the presence of the product of the previously performed radical polymerization. Perform radical polymerization of the monomer. If necessary, unreacted monomer components may be removed from the reaction mixture containing the product of the previous radical polymerization, or the unreacted monomer components may be left without being removed. Alternatively, it can be used for the subsequent radical polymerization. Subsequent radical polymerization is performed starting from all or a part of the remaining mercapto groups in the polyvalent mercaptan. A product in which one end of a polymer portion having another composition is bonded to the sulfur residue of the mercapto group serving as the starting point is obtained. This product may have unreacted mercapto groups. In this case, by repeating the second polymerization step twice,
By introducing a polymer portion having a third different composition and repeating the second polymerization step three times, polymer portions having third and fourth different compositions are introduced, and the number of repetitions of the second polymerization step is reduced. With each addition it is possible to introduce polymer parts having a further different composition.

After the completion of the addition of the second α, β-unsaturated monomer, radical polymerization for aging can be performed, if necessary. When the reaction mixture obtained in the polymerization step does not contain a volatile component such as a solvent or a residual monomer, it can be used as it is as a hot melt resin composition. When the reaction mixture contains a volatile component, a hot melt resin composition is obtained by removing the volatile component using a device such as a twin screw extruder or a thin film evaporator.

In Embodiment F, the conversion in the prepolymerization step was 5
When the second α, β-unsaturated monomer is added at a time after the remaining α, β-unsaturated monomer is volatilized and removed as necessary, the weight of two different compositions is reduced. A thermoplastic addition polymer having a united portion (or a thermoplastic addition polymer of the hot melt resin composition according to Embodiment A) is obtained. In this case, the first α, β-unsaturated monomer and the second α, β-unsaturated monomer are the same as the first α, β-unsaturated monomer as described in Embodiment E. And as the second α, β-unsaturated monomer, a carboxyl group-containing α, β-
When 0.5 to 25% by weight of the β-unsaturated monomer and 75 to 99.5% by weight of the (meth) acrylate monomer are used, the thermoplastic resin of the hot melt resin composition according to the embodiment D is used. A polymer is obtained.

In the embodiment F, the conversion in the prepolymerization step was set to 0.
When the second α, β-unsaturated monomer is gradually added after the remaining α, β-unsaturated monomer is volatilized and removed if necessary, the monomer composition in the polymerization system Gradually changes. As a result, the composition of the obtained copolymer portion gradually changes, and a thermoplastic addition polymer having a large number of slightly different compositions (gradient compositions) can be obtained.
Moreover, since radical polymerization is performed starting from the mercapto group of the polyvalent mercaptan, a thermoplastic addition polymer in which a polymer portion having an arbitrary composition is bonded from the polyvalent mercaptan portion by the valency of the mercapto group, that is, the polymer portion, A thermoplastic addition polymer having a polymer portion having a so-called gradient composition in which the composition continuously changes as a whole (or,
A thermoplastic addition polymer of the hot melt resin composition according to the embodiment B) is obtained. In this case, even if the polymer capable of forming the first α, β-unsaturated monomer and the polymer capable of forming the second α, β-unsaturated monomer are incompatible with each other. ,
For example, a thermoplastic addition polymer having a parallel light transmittance of 85% or more, preferably 90% or more (or a thermoplastic addition polymer of the hot melt resin composition according to Embodiment C) can be obtained. Here, the incompatibility of the polymer means that
This means that the polymer mixture has undergone phase separation, for example, in the form of a sea-island structure. The first α,
As the β-unsaturated monomer and the second α, β-unsaturated monomer, the first α, β-unsaturated monomer as described in embodiment E
As the unsaturated monomer and the second α, β-unsaturated monomer, a carboxyl group-containing α, β-unsaturated monomer of 0.5 to 0.5
25% by weight and (meth) acrylate monomer 75 to
When 99.5% by weight is used, a thermoplastic addition polymer of the hot melt resin composition according to the embodiment D is obtained. [Hot Melt Resin Composition of Aspect G] The hot melt resin composition of Aspect G contains a star-shaped thermoplastic addition polymer obtained by a production method including a preparation step and a polymerization step. The preparing step is a step of preparing a mixture containing an α, β-unsaturated monomer comprising a carboxyl group-containing α, β-unsaturated monomer and a (meth) acrylate monomer and a polyvalent mercaptan. is there. The polymerization step is a step of performing radical polymerization of an α, β-unsaturated monomer starting from a mercapto group of a polyvalent mercaptan.

The hot melt resin composition according to Embodiment G is characterized in that the α, β-unsaturated monomer contains a carboxyl group-containing α, β
-Consisting of unsaturated monomers and (meth) acrylic acid ester monomers, not performing the addition step, and the α, β-unsaturated monomer contained in the mixture obtained in the preparation step in the polymerization step. Except for performing radical polymerization, it is as described in Embodiment E.

In the polymerization step, the mixture obtained in the preparation step is charged into the polymerization system all at once or gradually added to carry out radical polymerization. The polymerization is preferably bulk polymerization or solution polymerization. The polymerization temperature is, for example, 20 to 180 ° C, preferably 100 to 150 ° C. Most preferably, no polymerization initiator is used, and even if used, it is used in an amount of 1/3 or less, preferably 1/10 or less, based on the weight of the polyvalent mercaptan. If the amount of the polymerization initiator is more than the above range, a large amount of linear polymer may be formed as a by-product and a thermoplastic addition polymer having a star structure may not be obtained.

The carboxyl group-containing α, β-unsaturated monomer / (meth) acrylate monomer is as described in Embodiment E. [Hot Melt Resin Composition of Embodiment H] The hot melt resin composition of Embodiment H is the hot melt resin composition according to any one of Embodiments A to G, and further includes a metal ion source.

The metal ion source is included in the hot melt resin composition, for example, by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by polymerization. Mixing can be performed by a direct heating mixing device such as a twin screw extruder, a kneader, and a heating roller. Before or after removing volatile components from the reaction mixture, a metal ion source may be mixed to obtain a hot melt resin composition.

Examples of the metal ion source include oxides, hydroxides, alcoholates, and organic carboxylate salts of metals such as sodium, potassium, lithium, magnesium, calcium, and zinc. One compound is used. In order to suppress the viscosity at the time of the hot melt operation, it is preferable to add 0.1 to 0.9 equivalent of metal ion to the carboxyl group of the thermoplastic addition polymer, more preferably 0.2 to 0.9.
~ 0.6 equivalents. If the metal ion is less than the above range, the heat resistance during use will be insufficient, and if it is more than the above range, it will be difficult to balance the performance of the hot melt resin composition, for example, the viscosity during hot melt operation will increase. [Hot Melt Resin Composition of Aspect I] The hot melt resin composition of Aspect I is the hot melt resin composition according to Aspect H and further contains a phosphate ester.

When the hot melt resin composition contains a phosphate, the hot melt workability of the hot melt resin composition is improved. Phosphate esters are, for example,
It is contained in the hot melt resin composition by being mixed with a reaction mixture containing a thermoplastic addition polymer obtained by polymerization. Before or after removing volatile components from the reaction mixture, a phosphate ester may be mixed to obtain a hot melt resin composition.

The phosphoric acid ester is, for example, at least one compound selected from the group consisting of monoesters, diesters and triesters of an alkyl group having 1 to 18 carbon atoms, and preferably has at least one carbon atom. 4 ~
It is at least one compound selected from the group consisting of monoester, diester and triester of eight alkyl groups. The amount of the phosphate ester is, for example, 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight based on 100 parts by weight of the thermoplastic addition polymer. If it is below the range, the hot melt workability may not be improved, and if it is above the range, the heat resistance may be insufficient. [Hot Melt Resin Composition of Embodiment J] The hot melt resin composition of Embodiment J contains a (meth) acrylic thermoplastic addition polymer, a metal ion source, and a phosphate. The (meth) acrylic thermoplastic addition polymer contains carboxyl group-containing α, β-unsaturated monomer units and (meth) acrylic acid ester monomer units as essential components, and may be copolymerized as necessary. Contains possible α, β-unsaturated monomer units.

The number average molecular weight of the (meth) acrylic thermoplastic addition polymer is the same as that of the thermoplastic addition polymer described in the embodiment A. The carboxyl group-containing α, β-unsaturated monomer unit / (meth) acrylate monomer unit is as described in Embodiment D. The copolymerizable α, β-unsaturated monomer unit includes the α, β-unsaturated monomer having a carboxyl group and the (meth) acryl among the α, β-unsaturated monomers described in the embodiment E. It is a unit derived from a monomer other than the carboxyl group-containing α, β-unsaturated monomer and the (meth) acrylate monomer, which can be copolymerized with the acid ester monomer.

The (meth) acrylic thermoplastic addition polymer may be, for example, the first α, β-
It is prepared by a method of radically polymerizing an unsaturated monomer or a second α, β-unsaturated monomer in the presence of a polymerization initiator without using a polyvalent mercaptan. The type of polymerization initiator is
For example, as described in the aspect E. The amount of the polymerization initiator is not particularly limited. The polymerization temperature is, for example, as described in Embodiment E. Examples of the polymerization method include solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization.

The metal ion source is as described in Embodiment H. The phosphate ester is as described in Embodiment I. [Hot Melt Resin Composition of Embodiment K] The hot melt resin composition of Embodiment K is the hot melt resin composition according to any one of Embodiments A to J, and further contains a tackifier.

Examples of the tackifier include rosin resins, terpene resins, aliphatic petroleum resins, aromatic petroleum resins, cumarone-indene resins, alkylphenol resins, xylene resins and the like. Use one or more of these resins. The tackifier has a function of reducing the viscosity at the time of hot melt work and improving the cohesive force at the time of use. The amount of the tackifier used is, for example, 1 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the hot melt resin composition according to any one of the embodiments A to J. If it is less than the above range, the viscosity may not be reduced or the cohesive strength may not be improved, and if it exceeds, the tack may be reduced or the cohesive strength may be insufficient when the hot melt resin composition is used as an adhesive. May be.

The tackifier is contained in the hot melt resin composition, for example, by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by polymerization. Before or after removing volatile components from the reaction mixture, a tackifier may be mixed to obtain a hot melt resin composition. [Hot Melt Resin Composition of Aspect L] The hot melt resin composition of Aspect L is the hot melt resin composition according to any one of Aspects A to K, and further contains a wax.

Examples of the wax include natural wax, paraffin wax, polypropylene wax, polyethylene wax, (meth) acrylate polymers having a saturated alkyl group having 18 or more carbon atoms, and the like. Use one or more waxes. Wax has a viscosity lowering effect during hot melt operation. The amount of the wax used is, for example, 1 to 100 parts by weight, preferably 10 to 5 parts by weight, per 100 parts by weight of the hot melt resin composition according to any one of the aspects A to K.
0 parts by weight. If it is lower than the above range, the effect of lowering the viscosity may not be exhibited, and if it is higher, the adhesive strength or the adhesive strength tends to decrease.

The wax is contained in the hot melt resin composition, for example, by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by polymerization. Before or after removing volatile components from the reaction mixture, wax may be mixed to obtain a hot melt resin composition. [Each Hot Melt Resin Composition from Aspects A to L] Each hot melt resin composition from Aspects A to L may further contain other additives as necessary. Examples of the additives include compounds that act as plasticizers for (meth) acrylic acid ester polymers such as phthalic acid esters and adipic acid esters; fillers such as silica powder and titanium oxide; dithiocarbamates and phenol compounds. It is at least one compound selected from the group consisting of antioxidants and the like. Examples of the amounts of these additives include the amounts employed in conventional hot melt resin compositions.

The additives are contained in the hot melt resin composition, for example, by mixing with a reaction mixture containing a thermoplastic addition polymer obtained by polymerization. Before or after removing volatile components from the reaction mixture, additives may be mixed to obtain a hot melt resin composition. (Effect) The hot melt resin composition of the embodiment A has a polyvalent mercaptan portion and a plurality of polymer portions having two or more different compositions radially extending from the polyvalent mercaptan portion and having a molecular weight of 10,000 to 10,000. Since it contains a thermoplastic addition polymer having a number average molecular weight of 200,000, it has excellent heat resistance and hot-melt workability, and is superior to a conventionally known moisture-curable and energy ray-irradiable cross-linkable hot-melt resin composition. The same or almost the same heat resistance can be exhibited with less time, equipment and energy, and there is little change in performance over time such as weather resistance.

The hot melt resin composition of Embodiment B is a thermoplastic addition polymer having a polyvalent mercaptan portion and a plurality of polymer portions having two or more different compositions radially extending from the polyvalent mercaptan portion. Since the polymer portion contains a thermoplastic addition polymer having a composition that is continuously changed in the entire aggregate of the thermoplastic addition polymer, it has excellent heat resistance and hot melt workability, and is conventionally known. It can exhibit the same or almost the same heat resistance with less time, equipment, and energy than the moisture-curable and energy-beam-irradiated cross-linkable hot melt resin composition, and can exhibit performance changes over time such as weather resistance. It is hard to wake up and is transparent.

[0212] The hot melt resin composition of the embodiment C comprises 1
Having a number average molecular weight of 0000 to 200,000,
It has only one glass transition temperature peak having a width of 0 ° C. or more and contains a thermoplastic addition polymer having a parallel light transmittance of 85% or more, so that it has excellent heat resistance and hot melt workability, and is conventionally known. Less time than moisture-curable and energy-irradiated crosslinkable hot melt resin compositions
It can exhibit the same or almost the same heat resistance with equipment and energy, is unlikely to cause a change in performance over time such as weather resistance, and is transparent.

In the hot melt resin composition of Embodiment D, the thermoplastic addition polymer according to any one of Embodiments A to C, wherein the thermoplastic addition polymer has a carboxyl group-containing α, β-unsaturated monomer unit and a (meth) acrylate ester monomer Since it is composed of monomer units, it is more excellent in heat resistance and weather resistance. Aspect E
A hot melt resin composition is prepared by preparing a mixture containing a first α, β-unsaturated monomer and a polyvalent mercaptan, and adding a first α, β-unsaturated monomer to the mixture. An additional step of adding a second α, β-unsaturated monomer having a composition different from that of the body, and starting with the first α, β-unsaturated monomer and the second α-β-unsaturated monomer starting from the mercapto group of the polyvalent mercaptan. α,
Since it contains a thermoplastic addition polymer obtained by a production method including a polymerization step of performing radical polymerization of β-unsaturated monomers, it has excellent heat resistance and hot melt workability, and is a conventionally known moisture-curable type. It can exhibit the same or almost the same heat resistance with less time, equipment, and energy than the energy ray irradiation type crosslinkable hot melt resin composition, and hardly causes a temporal change in performance such as weather resistance.

The hot-melt resin composition of Embodiment F is characterized in that, in Embodiment E, the production method is characterized in that the first step starts from the mercapto group of the polyvalent mercaptan between the preparation step and the addition step
Since the method further includes a pre-polymerization step of performing radical polymerization of the α, β-unsaturated monomer, there is an additional advantage that both heat resistance and hot melt workability can be easily achieved. The hot melt resin composition of Embodiment G contains an α, β-unsaturated monomer comprising a carboxyl group-containing α, β-unsaturated monomer and a (meth) acrylate monomer and a polyvalent mercaptan. Of a branched structure (star-shaped structure) obtained by a production method including a preparation step of preparing a mixture, and a polymerization step of performing radical polymerization of an α, β-unsaturated monomer starting from a mercapto group of a polyvalent mercaptan. Because it contains a thermoplastic addition polymer, it has excellent heat resistance and hot melt workability, and is equivalent to the conventionally known moisture-curable and energy beam-irradiable cross-linkable hot melt resin compositions in less time, equipment and energy. Alternatively, almost the same heat resistance can be exhibited, and a change in performance over time such as weather resistance hardly occurs.

The hot melt resin composition of Embodiment H in any one of Embodiments A to G further comprises a metal ion source, so that the thermoplastic addition polymer is cross-linked by metal ions, so that the cohesive force becomes larger. There is an additional advantage. Since the hot melt resin composition of Embodiment I further contains a phosphate ester in Embodiment H, the phosphate ester coordinates to the metal ion, so that the bonding force between the carboxyl group and the metal ion is reduced, and the hot melt operation is performed. It also has the advantage that the performance is improved.

The hot melt resin composition of Embodiment J comprises a (meth) acrylic thermoplastic addition polymer containing a carboxyl group-containing α, β-unsaturated monomer unit and a (meth) acrylate monomer unit. Since it contains a metal ion source and a phosphoric acid ester, it has excellent heat resistance and hot melt workability, and requires less time than conventionally known moisture-curable and energy ray-irradiable crosslinkable hot melt resin compositions. Equivalent or almost equivalent heat resistance can be exhibited with equipment and energy, and it is hard to cause a change in performance over time such as weather resistance.

Since the hot melt resin composition of Embodiment K further contains a tackifier resin in any of Embodiments A to J, the advantage of lower viscosity or higher cohesive force is further obtained. Have. The hot melt resin composition of the embodiment L has an advantage that the viscosity is lower since any one of the embodiments A to L further contains a wax. [Pressure-sensitive adhesive composition of still another embodiment] Another pressure-sensitive adhesive composition of the present invention will be described below.

The pressure-sensitive adhesive composition according to the present invention is characterized in that it has another embodiment α
According to the present invention, there is provided a pressure-sensitive adhesive composition for producing a pressure-sensitive adhesive for flexible PVC applied to a flexible polyvinyl chloride molded article, wherein the acrylic block polymer and the acrylic block polymer are dissolved and / or dispersed. And an organic solvent. The acrylic block polymer is produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. The preparing step is a step of preparing a first mixture containing a polyvalent mercaptan and a first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having a glass transition point of 273 K or more. is there. The first polymerization step is a step of obtaining a reaction mixture by performing radical polymerization of the first α, β-unsaturated monomer starting from the mercapto group of the polyvalent mercaptan. The addition step can form a polymer that is incompatible with the high glass transition point type polymer, and
In this step, a monomer mixture containing a (meth) acrylic acid alkyl ester monomer is added to the reaction mixture to obtain a second mixture. The second polymerization step is a step of performing radical polymerization of a monomer contained in the second mixture.

The pressure-sensitive adhesive composition according to the present invention has another aspect
According to this, the composition is the same as the pressure-sensitive adhesive composition of Embodiment α except that the monomer mixture further contains a reactive functional group-containing α, β-unsaturated monomer. The pressure-sensitive adhesive composition of the present invention, according to another embodiment γ, except that the pressure-sensitive adhesive composition further includes a crosslinking agent having at least two functional groups capable of reacting with the reactive functional group.
The same as the pressure-sensitive adhesive composition of the embodiment α or β.

According to another embodiment δ, the pressure-sensitive adhesive product of the present invention comprises a pressure-sensitive adhesive layer for soft PVC formed using any one of the pressure-sensitive adhesive compositions of modes α to γ. Applied to polyvinyl chloride molded products. The pressure-sensitive adhesive product of the present invention, according to other aspects ε, a soft PVC pressure-sensitive adhesive layer formed using any of the pressure-sensitive adhesive compositions of aspects α to γ, and a soft PVC pressure-sensitive adhesive layer And a soft polyvinyl chloride base material adhered to one or both surfaces.

The actions of the pressure-sensitive adhesive composition of the embodiments α to γ and the pressure-sensitive adhesive products of the embodiments δ to ε are as follows. (Function) In the acrylic block polymer of the pressure-sensitive adhesive composition according to the modes α to γ, the high glass transition point type polymer part is a monomer mixture containing a (meth) acrylic acid alkyl ester monomer. It is dispersed in the polymer portion, and the high glass transition point polymer portion and the polymer portion of the monomer mixture are chemically bonded. This suggests that a simple blend of a polymer of a monomer mixture containing an alkyl (meth) acrylate monomer and a polymer having a high glass transition point tends to separate in a solution state. In the system of the present invention, this tendency can be demonstrated by not showing such a tendency. The high glass transition point polymer part has a microdomain structure with respect to the polymer part of the monomer mixture containing the alkyl (meth) acrylate monomer, and the physical part of the sticky polymer part Since it acts as a crosslinking agent, the pressure-sensitive adhesive composition of the present invention forms a pressure-sensitive adhesive exhibiting high cohesive strength without impairing its adhesiveness even when applied to a flexible polyvinyl chloride molded article.

(Effects) Since the pressure-sensitive adhesive compositions of modes α to γ contain an acrylic block polymer and an organic solvent, they have an excellent balance between cohesive strength and adhesive strength, and have an excellent balance of cohesive strength due to migration of plasticizer. It can be used for producing a pressure-sensitive adhesive layer for flexible PVC which is hardly deteriorated and which has a practically important shelf life of the pressure-sensitive adhesive product for flexible PVC.

In the pressure-sensitive adhesive composition of Embodiment β, since the monomer mixture further contains a reactive functional group-containing α, β-unsaturated monomer, it has a functional group that reacts with these reactive functional groups. There is an additional advantage that the cohesion can be arbitrarily controlled by using a crosslinking agent. The pressure-sensitive adhesive composition of Embodiment γ has at least two functional groups that can react with the reactive functional group when the monomer mixture further contains a reactive functional group-containing α, β-unsaturated monomer. Since it further contains a crosslinking agent,
There is an additional advantage that a sufficient cohesive force can be obtained with a small amount of the crosslinking agent.

Since the pressure-sensitive adhesive product of the embodiment δ or ε has the pressure-sensitive adhesive layer for soft PVC formed using the pressure-sensitive adhesive composition of the embodiments α to γ, it can be applied to a flexible polyvinyl chloride molded article. Then, the balance between cohesive force and adhesive force is excellent, the decrease in cohesive force due to migration of the plasticizer does not easily occur, and the shelf life of a practically important soft PVC adhesive product is excellent. (Composition for pressure-sensitive adhesive from aspect α to γ) The composition for pressure-sensitive adhesive of aspect α is a composition for pressure-sensitive adhesive for making a pressure-sensitive adhesive for flexible PVC applied to a flexible polyvinyl chloride molded article, Contains an acrylic polymer and an organic solvent. The organic solvent contains the acrylic block polymer in a dissolved and / or dispersed state.

The acrylic block polymer is produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. The preparation process consists of multivalent mercaptan and 2
This is a step of preparing a first mixture containing a first α, β-unsaturated monomer capable of producing a high glass transition point type polymer having a glass transition point of 73 K or more. In the first polymerization step, the first polymerization starts with the mercapto group of the polyvalent mercaptan as a starting point.
Is a step of obtaining a reaction mixture by performing radical polymerization of α, β-unsaturated monomers. The addition step is a reaction in which a monomer mixture containing a (meth) acrylic acid alkyl ester monomer, which can form a polymer incompatible with the high glass transition point type polymer, is obtained in the first polymerization step. Second in addition to the mixture
This is a step of obtaining a mixture. The second polymerization step is a step of performing radical polymerization of a monomer contained in the second mixture.

Since the polyvalent mercaptan has already been described in the first embodiment, the description is omitted here. Polyvalent mercaptan used in the pressure-sensitive adhesive composition of the embodiments α to γ is, from the viewpoint of efficiently producing a block polymer, and by introducing a structure in which the obtained polymer radially extends from the same center. From the viewpoint of higher performance, a compound having 2 to 10 mercapto groups (that is, a mercaptan having 2 to 10 valences) is preferable, and a compound having 3 to 6 mercapto groups is more preferable (that is, 3 to 6 mercapto groups). Mercaptan). Mercaptans having only one mercapto group do not provide a radially extended structure of the polymer portion. Since mercaptans having more than 10 mercapto groups do not have a structure extending radially from the same center, there is a possibility that desired physical properties may not be exhibited.

In the acrylic block polymer according to the present invention, the plurality of radially extending polymer portions have two or more different compositions. This difference in composition is, when derived from a homopolymer, the difference in the monomer units constituting the polymer, the number average molecular weight of the polymer, or, when derived from the copolymer, It can be obtained by differences in units, number average molecular weight of the polymer, differences in the ratio of monomer units, and the like. The polymer portion usually has a number average molecular weight of 1,000 to 500,0.
00, preferably 5,000 to 200,000, more preferably 10,000 to 100,000. If the number average molecular weight of the polymer portion is below the above range, it may not be possible to introduce properties based on the polymer portion into this block polymer, and if it exceeds, the viscosity at the time of production increases,
This may be undesirable in terms of productivity.

In the acrylic block polymer, the combination of polymer portions having different compositions differs depending on the performance (or use) required for the block polymer. Basically, the combination of polymer portions is a combination of polymer portions derived from polymers having different glass transition points (Tg). By combining the polymer portions derived from the polymers having different Tg, the polymer portions derived from the polymer having a low Tg form a continuous phase. As an example of such a block polymer, a combination of polymethyl methacrylate (PMMA) as a polymer having a high Tg and polybutyl acrylate (PBA) as a polymer having a low Tg can be given. For this combination, PM
The number average molecular weight of MA is preferably 5,000 to 200,000, and the number average molecular weight of PBA is 10,000 to 15
000 is preferable, and the weight ratio of PMMA / PBA is 1
The range of 0/90 to 90/10 is preferred. Outside these ranges, sufficient performance may not be obtained. In order for the polymer portion derived from the polymer having a low Tg to form a continuous phase, the proportion of the polymer having a low Tg should be increased or
Alternatively, it is necessary to lower the melt viscosity of the polymer having a low Tg.

In the acrylic block polymer of the present invention,
The polyvalent methacrylate moiety is a residue of a trivalent to hexavalent mercaptan, and the plurality of polymer moieties have two different compositions and have the following general formula (3):

[0230]

Embedded image

A polymer represented by the following formula is possible. In the above formula (3), a polymer portion having a different composition from PA and PB, for example, the following combinations are possible. PA: PB PMMA: PBA PSt: P (BA / AA) PMMA: P (BA / AA) In the above formula (3), the following formula:

[0232]

Embedded image

The moiety represented by is a residue of a trivalent to hexavalent mercaptan. In the above formula (3), n + m is a number equal to or greater than 3 and equal to or less than the valency of the residue of the mercaptan, and n is 0.1 or less.
1 or more, preferably 0.5 or more, m is 0.1 or more,
Preferably, the number is 0.5 or more. If n or m is less than the above-mentioned value, there is a possibility that desired sufficient performance may not be obtained.

The first α, β-unsaturated monomer is 273K
As described above, at least one monomer having a glass transition point of preferably 300 K or more and capable of producing at least one high glass transition point type polymer selected from the group consisting of homopolymers and copolymers. When the glass transition point of the high glass transition point type polymer falls below the above range, the pressure-sensitive adhesive does not have sufficient cohesive force, and the cohesive force is greatly reduced due to the transfer of the plasticizer. As the first α, β-unsaturated monomer, for example, at least one selected from the group consisting of styrene, vinyl acetate, acrylonitrile, methacrylonitrile and methyl methacrylate is 5 to 40% by weight, preferably 10 to 40% by weight. 30% by weight, with the balance being the above-mentioned alkyl (meth) acrylate monomer and the reactive functional group-containing α, β-
It is at least one selected from the group consisting of unsaturated monomers and copolymerizable α, β-unsaturated monomers.

A first mixture containing a polyvalent mercaptan and a first α, β-unsaturated monomer is prepared. The first mixture is
If necessary, for example, aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and pentane; It may contain an organic solvent. The organic solvent may be a single solvent or a mixed solvent.

The number average molecular weight of the acrylic block polymer is from 2,000 to 1,000,000, preferably 1
0000 to 400,000, more preferably 20,000
00 to 200,000. If the number average molecular weight is lower than the above range, properties as a block polymer may not be exhibited, and if it is higher, the viscosity may be high and handleability may be deteriorated.

The acrylic block polymer has a plurality of polymer parts having two or more different compositions when formed through a first polymerization step and a second polymerization step described below.
By repeating the second polymerization step two or more times, it is possible to have a plurality of polymer parts having three or more different compositions. In the first polymerization step, the first α, β is obtained starting from the mercapto group of the polyvalent mercaptan.
Performing radical polymerization of unsaturated monomers. By this radical polymerization, a product in which one end of a polymer portion having one composition is bonded to one or a plurality of sulfur residues of a mercapto group in each molecule of the polyvalent mercaptan is obtained.
This product has unreacted mercapto groups. In order to efficiently bind one end of the polymer portion to the sulfur residue, it is preferable not to add an unnecessary polymerization initiator to the polymerization system.

In the adding step, the second mixture is obtained by adding the monomer mixture to the reaction mixture obtained by the radical polymerization performed earlier. This monomer mixture is capable of forming a polymer that is incompatible with the high glass transition point type polymer,
Contains acrylic acid alkyl ester monomers. here,
“Incompatible” means that the tangent loss (tan δ, storage modulus G ′ and loss modulus G ”are measured in the dynamic viscoelasticity measurement of the polymer.
Ratio: tan δ = G ″ / G ′) means that the number of peaks is 2. That is, it is caused by the polymer of the monomer mixture containing the alkyl (meth) acrylate monomer. The peak appears on the low temperature side, and the peak originating from the high glass transition type polymer having a glass transition point of 273 K or more appears on the high temperature side. Means one peak without separation.

The second mixture may be, for example,
Aromatic solvents such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; and organic solvents such as aliphatic hydrocarbons such as hexane and pentane. Good. The organic solvent may be a single solvent or a mixed solvent. The second α, β-unsaturated monomer used in the addition step contains a (meth) acrylic acid alkyl ester monomer as an essential component and, if necessary, contains a reactive functional group-containing α, β- It may further include an unsaturated monomer. The second α, β-unsaturated monomer may or may not further comprise a reactive functional group-containing α, β-unsaturated monomer, and may be an α-β-unsaturated monomer copolymerizable with these monomers. , Β-unsaturated monomers.

The alkyl (meth) acrylate monomer is not particularly limited as long as it is a (meth) acrylic acid alkyl ester which is usually used for an adhesive, but the alkyl group has 4 to 18 carbon atoms. Things are given, for example,
Butyl (meth) acrylate, isobutyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n- (meth) acrylate
Octyl, isooctyl (meth) acrylate, (meth)
At least one selected from the group consisting of lauryl acrylate and stearyl (meth) acrylate is exemplified.

The amount of the alkyl (meth) acrylate monomer used to obtain the acrylic block polymer is based on the total amount of the second α, β-unsaturated monomer used. , 68 to 99.89% by weight. If the amount of the (meth) acrylic acid alkyl ester monomer is out of the above range, the flexibility and tackiness of the pressure-sensitive adhesive may not be obtained.

The second α, β-unsaturated monomer used for obtaining the acrylic block polymer may further comprise, if necessary, a reactive functional group-containing α, β-unsaturated monomer. Can be included. The reactive functional group-containing α, β-unsaturated monomer is at least one selected from the group consisting of a carboxyl group-containing α, β-unsaturated monomer and a hydroxyl group-containing α, β-unsaturated monomer. is there.

The carboxyl group-containing α, β-unsaturated monomer is not particularly limited as long as it is an α, β-unsaturated monomer having a carboxyl group. For example, acrylic acid, methacrylic acid, itaconic acid, croton At least one selected from the group consisting of unsaturated carboxylic acids such as acid, maleic anhydride, and maleic acid. When a carboxyl group-containing α, β-unsaturated monomer is used to obtain an acrylic block polymer, the amount of the carboxyl group-containing α, β-unsaturated monomer depends on the amount of the second α, β used. It is, for example, 0.1 to 10% by weight, preferably 2 to 8% by weight, based on the total amount of the β-unsaturated monomer. Carboxyl group-containing α, β-
If the amount of the unsaturated monomer is less than 0.1% by weight, the cohesive force of the pressure-sensitive adhesive may be insufficient, and if it exceeds 10% by weight, the cohesive force becomes too high, and the adhesive force decreases. May be.

The hydroxyl group-containing α, β-unsaturated monomer is not particularly limited as long as it is an α, β-unsaturated monomer having a hydroxyl group. For example, 2-hydroxyethyl (meth) acrylate, From hydroxy group-containing polymerizable monomers such as 2-hydroxypropyl (meth) acrylate and polycaprolactone-modified 2-hydroxyethyl (meth) acrylate (trade name: Praxel F series (manufactured by Daicel Chemical Industries, Ltd.)) At least one selected from the group consisting of: Hydroxyl-containing α, β-
When an unsaturated monomer is used, the amount of the hydroxyl group-containing α, β-unsaturated monomer is, for example, 0.1% based on the total amount of the second α, β-unsaturated monomer used. It is from 0.1 to 2% by weight, preferably from 0.1 to 1% by weight. Hydroxyl group-containing α, β-
When the amount of the unsaturated monomer is less than 0.01% by weight, the crosslinking point becomes insufficient, so that the crosslinking density is insufficient and the cohesive strength may be insufficient. Or the cohesive strength becomes too high, and the adhesive strength may decrease.

The second α, β-unsaturated monomer used to obtain the acrylic block polymer contains a (meth) acrylic acid alkyl ester monomer as an essential component,
Regardless of whether it further contains a reactive functional group-containing α, β-unsaturated monomer, α, β copolymerizable with these monomers
It may further include a β-unsaturated monomer. The copolymerizable α, β-unsaturated monomer is not particularly restricted but includes, for example, aromatic α, β-unsaturated monomers such as styrene and α-methylstyrene; vinyl acetate, vinyl propionate Vinyl esters such as N-vinylpyrrolidone,
N-group-containing α, β-unsaturated monomers such as acryloylmorpholine; α, β-unsaturated nitriles such as (meth) acrylonitrile; and unsaturated amides such as (meth) acrylamide and N-methylolacrylamide. At least one selected from Copolymerizable α, β used to obtain acrylic block polymer
The amount of the unsaturated monomer is, for example, 0 to 20% by weight based on the total amount of the second α, β-unsaturated monomer used in consideration of the balance between tackiness and cohesion and cohesion. %. When the amount of the copolymerizable α, β-unsaturated monomer exceeds 20% by weight, the acrylic block polymer becomes hard,
Adhesive strength may decrease.

The composition of the second α, β-unsaturated monomer used to obtain the acrylic block polymer has a Tg of 2 from the balance of tack and adhesion.
It is preferable to use them in combination so as to be 00K to 240K. The amount of the second α, β-unsaturated monomer used to obtain the acrylic block polymer is a total of 100% by weight of the monomer and the first α, β-unsaturated monomer. Parts by weight, for example, 60 to 95 parts by weight, preferably 70 to 95 parts by weight.
90 parts by weight. If the amount of the second α, β-unsaturated monomer exceeds 95 parts by weight, that is, if the amount of the first α, β-unsaturated monomer is less than 5 parts by weight, the migration of the plasticizer will occur. In some cases, the cohesive strength is significantly reduced. Also, the second α,
If the amount of the β-unsaturated monomer is less than 60 parts by weight, that is, if the amount of the first α, β-unsaturated monomer exceeds 40 parts by weight, the physical properties of the pressure-sensitive adhesive may be greatly reduced. is there.

In the second polymerization step, radical polymerization of the monomers contained in the second mixture is performed. If necessary, unreacted monomer components can be removed from the reaction mixture containing the product of the previous radical polymerization, or
The unreacted monomer components may be left without being removed and used for the subsequent radical polymerization. Subsequent radical polymerization is performed starting from all or a part of the remaining mercapto groups in the polyvalent mercaptan. A product in which one end of a polymer portion having another composition is bonded to the sulfur residue of the mercapto group serving as the starting point is obtained. This product may have unreacted mercapto groups.
In this case, by repeating the second polymerization step twice, a polymer portion having a third different composition is introduced, and by repeating the second polymerization step three times, the third and fourth polymerization steps are performed.
, A polymer portion having a different composition can be introduced as the number of repetitions of the second polymerization step is increased.

The first and second polymerization steps for producing the acrylic block polymer can be carried out by a conventional radical polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. In order to obtain an inexpensive polymer, a bulk polymerization method containing no extra volatile components is preferred. The polymerization temperature is preferably from 30 to 200 ° C., more preferably from 100 to 15 ° C., which enables stable bulk polymerization without using a polymerization initiator.
0 ° C.

In the polymerization for producing the acrylic block polymer, a conventional radical polymerization initiator (for example, 2,2′-
Azo-based polymerization initiators such as azobisisobutyronitrile and 2,2'-azobiscyclohexanecarbonitrile; and peroxide-based polymerization initiators such as benzoyl peroxide) can be used. 1 / of polyvalent mercaptan
3 or less, preferably 1/10 or less, more preferably not used. When the polymerization initiator is used in a larger amount than the above ratio, a large amount of the polymer extended from the polymerization initiator is generated in addition to the polymer portion extended from the polyvalent mercaptan that gives the block polymer, and the efficiency of the block polymer production is increased. In addition, polymerization stability of bulk polymerization, which is an industrially inexpensive production method, deteriorates, a runaway reaction occurs, and in the worst case, there is a risk of explosion.

As a procedure for producing the acrylic block polymer, radical polymerization of the first α, β-unsaturated monomer was carried out starting from the mercapto group of the polyvalent mercaptan, and the polymerization rate was 50% or more. Preferably, when the content becomes 80% or more, an acrylic block polymer can be obtained by adding and polymerizing a monomer mixture containing an alkyl (meth) acrylate monomer. The reason why the polymerization rate of the previously performed radical polymerization is set to 50% or more is that the properties of the polymer forming the block are obtained even if the next polymerization is performed without removing the unsaturated monomer remaining after the polymerization. Is to be as different as possible. Therefore, after the first polymerization step, the remaining unsaturated monomer can be volatilized and removed. If each radical polymerization is terminated by the addition of a polymerization inhibitor, it is possible to prevent a polymer portion having a different composition from being connected to the tip of the generated polymer portion by a subsequent radical polymerization.

If the polymerization is carried out in more stages as described above, an acrylic block polymer comprising a combination of three or more polymers can be obtained. The organic solvent used in the pressure-sensitive adhesive composition of the present invention is not particularly limited as long as it is a liquid substance in which the acrylic block polymer can be dissolved and / or dispersed. For example, aromatic hydrocarbons such as toluene and xylene And esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; ketones such as acetone and methyl ethyl ketone; and aliphatic hydrocarbons such as hexane and pentane. Or a mixed solvent of two or more. The amount of the organic solvent is, for example, 100 to 400 parts by weight, preferably 150 to 35 parts by weight based on 100 parts by weight of the acrylic polymer.
0 parts by weight. If the ratio is less than the above range, the viscosity may be too high to cause difficulty in the coating operation.

The pressure-sensitive adhesive composition of the present invention is characterized in that, when the acrylic block polymer is prepared using a monomer mixture containing a reactive functional group-containing α, β-unsaturated monomer, A crosslinking agent may be further included. The crosslinking agent has at least two functional groups per molecule that can react with the reactive functional groups of the acrylic polymer. Examples of the crosslinking agent used in the present invention include a polyfunctional epoxy compound, a polyfunctional melamine compound, a polyfunctional isocyanate compound, a metal-based crosslinking agent, and an aziridine compound. In particular, a polyfunctional isocyanate compound is preferable in the reaction between a hydroxyl group and a carboxyl group.

The polyfunctional epoxy compound is not particularly limited as long as it has two or more epoxy groups per molecule. Examples thereof include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether,
1,6-hexanediol diglycidyl ether, bisphenol A / epichlorohydrin type epoxy resin,
N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyltoluidine And the like,
Each may be used alone, or two or more may be used in combination.

A polyfunctional melamine compound is
There is no particular limitation as long as the compound has at least two of a methylol group, an alkoxymethyl group, and an imino group.
For example, hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexabutoxymethyl melamine, hexapentyloxymethyl melamine, etc., are used alone or in combination of two or more.

As the polyfunctional isocyanate compound, 1
There is no particular limitation as long as the compound has two or more isocyanate groups per molecule. For example, tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate, xylylene diisocyanate, meta-xylylene diisocyanate Isocyanate, 1,5-naphthalenediisocyanate,
Isocyanate compounds such as hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate; Sumidur N (Sumitomo Bayer Urethane Co., Ltd.)
A polyisocyanate compound having an isocyanurate ring such as Desmodur IL, HL (manufactured by Bayer AG) and Coronate EH (manufactured by Nippon Polyurethane Industry Co., Ltd.); Sumidule L (Sumitomo Bayer) Adduct polyisocyanate compounds such as Urethane Co., Ltd.) and adduct polyisocyanate compounds such as Coronate L (manufactured by Nippon Polyurethane Co., Ltd.). These can be used alone or in combination of two or more. Also, blocked isocyanates in which the isocyanate groups of those polyvalent isocyanate compounds have been reacted with a masking agent having active hydrogen to be inactivated can be used.

Examples of the metal crosslinking agent include acetylacetone, methyl acetoacetate, acetoacetate, and the like such as aluminum, zinc, cadmium, nickel, cobalt, copper, calcium, barium, titanium, manganese, iron, lead, zirconium, chromium, and tin. Metal chelate compounds coordinated with ethyl acetate, ethyl lactate, methyl salicylate and the like can be mentioned. These can be used alone or in combination of two or more.

Examples of the aziridine compound include N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, bisisophthaloyl-1 −
(2-methylaziridine), tri-1-aziridinyl phosphoxide, N, N'-diphenylethane-
4,4'-bis (1-aziridinecarboxamide) and the like. These can be used alone or in combination of two or more.

The amount of the crosslinking agent used is, for example, 0.1 to 1 with respect to 100 parts by weight of the acrylic block polymer.
0 parts by weight, preferably 0.5 to 5 parts by weight. When the amount of the crosslinking agent is less than 0.1 part by weight, the crosslinking point becomes insufficient, so that the crosslinking density is insufficient and the cohesive force may be insufficient, and if it exceeds 10 parts by weight, the crosslinking density becomes high. Too long, and the adhesive strength may decrease.

The pressure-sensitive adhesive composition of the present invention can contain a tackifier usually used for a pressure-sensitive adhesive, if necessary. Examples of the tackifier include (polymerized) rosin type, (polymerized) rosin ester type, terpene type, terpene phenol type, coumarone type, coumarone indene type, styrene resin type, xylene resin type, phenol resin type, petroleum resin type, etc. Tackifier. These can be used alone or in combination of two or more. The amount of the tackifier is, for example, 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the acrylic block polymer. If the ratio is below the above range, the adhesion to the adherend may not be improved. If the ratio is above the range, the tack may decrease and the adhesion may decrease.

The pressure-sensitive adhesive composition of the present invention may contain, if necessary, a filler, a pigment, a diluent, an antioxidant, and the like which are usually used in pressure-sensitive adhesives, regardless of whether they contain a tackifier. It may contain at least one additive selected from the group consisting of an ultraviolet absorber, an ultraviolet stabilizer and the like. The composition for a pressure-sensitive adhesive of the present invention is used, for example, for producing a pressure-sensitive adhesive product by a method described below. [Adhesive product from aspect δ to ε] The adhesive product of the present invention is:
It is provided with a pressure-sensitive adhesive layer for soft PVC formed using the pressure-sensitive adhesive composition of the embodiments δ to ε, and is applied to a soft polyvinyl chloride molded product.

The pressure-sensitive adhesive layer for soft PVC is formed, for example, as follows. (A) a cross-linking step of applying the pressure-sensitive adhesive composition of the present invention containing an acrylic block polymer and an organic solvent in which the acrylic block polymer is dissolved and / or dispersed to a substrate to be dried and cross-linked; To form a pressure-sensitive adhesive layer for soft PVC.

Each monomer mixture used in the polymerization step for producing the acrylic block polymer may further contain a reactive functional group-containing α, β-unsaturated monomer. When the monomer mixture contains a reactive functional group-containing α, β-unsaturated monomer, the pressure-sensitive adhesive composition further comprises a crosslinking agent having at least two functional groups capable of reacting with the reactive functional group. May be included.

In the crosslinking step, the organic solvent is removed from the pressure-sensitive adhesive composition by applying the pressure-sensitive adhesive composition to an object to be coated and dried to crosslink the acrylic block polymer. As the object to be coated, for example, a separator, a support, a substrate, and the like described below are appropriately used. Crosslinking of the acrylic block polymer is performed by, for example, room temperature crosslinking that is allowed to stand at room temperature for one week or more, or high temperature accelerated crosslinking that promotes the reaction in a constant temperature room at 40 to 50 ° C.

When the acrylic block polymer is prepared using a monomer mixture containing a reactive functional group-containing α, β-unsaturated monomer, it reacts with the reactive functional group of the acrylic polymer. It is cross-linked by reaction with a cross-linking agent having at least two functional groups. The cross-linking agent used here is the same as the cross-linking agent used in the pressure-sensitive adhesive composition. The conditions for crosslinking may be appropriately set according to the crosslinking agent used.

The pressure-sensitive adhesive product of the present invention may further include a separator attached to one or both surfaces of the pressure-sensitive adhesive layer for soft PVC. The pressure-sensitive adhesive product of the present invention includes two soft PVC pressure-sensitive adhesive layers, a support sandwiched between the soft PVC pressure-sensitive adhesive layers, and one surface of the soft PVC pressure-sensitive adhesive layer opposite to the support. And a separator attached to the substrate.

The pressure-sensitive adhesive product of the present invention may further include a separator adhered to one surface of the pressure-sensitive adhesive layer for flexible PVC, and a substrate adhered to the other surface of the pressure-sensitive adhesive layer for flexible PVC. The substrate is, for example, a flexible polyvinyl chloride substrate. Examples of the separator used in the present invention include, for example, a paper substrate having a surface directly subjected to release treatment with a release agent such as silicone, a laminated film in which a polyethylene film is laminated on the back surface of the release-treated paper substrate, polyester -A plastic film such as polyethylene or polypropylene is used.

The pressure-sensitive adhesive product of the present invention is, for example, a pressure-sensitive adhesive sheet, a pressure-sensitive adhesive tape, a pressure-sensitive adhesive label, a double-sided tape for soft PVC, or a soft pressure-sensitive adhesive sheet, a soft pressure-sensitive adhesive tape, a soft pressure-sensitive adhesive label, or the like. The adhesive product of the present invention is produced by the following method, but the production method is not limited. On one side of the separator, the pressure-sensitive adhesive composition of the present invention, which is coated with a composition containing at least an acrylic block polymer, a cross-linking agent and an organic solvent, dried, and then formed on the surface of the separator. The layer is overlaid on one side of another separator, a base material described below or a support described below, and transferred under pressure (for example, at a pressure of 1 to 5 kg / cm ² ). The pressure-sensitive adhesive layers formed on the surfaces of the two separators can be superposed on both surfaces of a support described later, and similarly transferred under pressure. On one or both surfaces of the support, a pressure-sensitive adhesive composition of the present invention, which is coated with at least an acrylic block polymer, a cross-linking agent and an organic solvent, is dried, and the obtained pressure-sensitive adhesive layer is dried. Attach a separator so as to cover.

The dry thickness of the pressure-sensitive adhesive layer is, for example, 10 to 1
00 μm. Drying is performed, for example, by leaving it in a hot air dryer at 70 to 100 ° C. for 2 to 10 minutes. The pressure-sensitive adhesive composition and the pressure-sensitive adhesive product of the present invention are applied to a flexible polyvinyl chloride molded product. The soft polyvinyl chloride molded article is an adherend to which an adhesive layer is adhered, and may be, for example, a sheet, tape, wallpaper, foam (foam), and the like.

In the pressure-sensitive adhesive product of the present invention, the support may be a soft polyvinyl chloride molded product.

[0270]

EXAMPLES Examples of the present invention and comparative examples outside the scope of the present invention will be shown below, but the present invention is not limited to the following examples. In the following, “%” means “% by weight” and “parts” means “parts by weight”. The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) were determined by gel permeation chromatography (GPC) in terms of polystyrene.

The glass transition temperature (Tg) was measured using a differential scanning calorimeter “DSC- manufactured by Perkin Elmer”.
7 ". The amount of mercapto groups consumed was determined by the Elleman method (colorimetric method) using a dimethylformamide solvent. First, Examples and Comparative Examples in which the pressure-sensitive adhesive composition of the present invention is the acrylic hot-melt pressure-sensitive adhesive of the fifth to twelfth aspects will be described.

Example 1 A model equipped with a Max Blend blade (manufactured by Heavy Industries, Ltd.) equipped with a nitrogen inlet tube, a dropping funnel, a thermometer, and a cooling tube was used.
Methyl methacrylate (M
297 parts of MA), 3 parts of acrylic acid (AA) and 275 parts of ethyl acetate were added, and the mixture was heated to 83 ° C. under a nitrogen atmosphere. After the internal temperature reaches 83 ° C., 4 parts of pentaerythritol tetrakisthioglycolate, a tetravalent mercaptan, and 2,2′-azobis (2-methyl) manufactured by Nippon Hydrazine Industry Co., Ltd. whose trade name is ABN-E Butyronitrile)
[Similarly, ABN-E was used as 2,2'-azobis (2-methylbutyronitrile). 0.8 parts,
The polymerization was initiated by adding 25 parts of ethyl acetate. Start polymerization 8
After 0 minute and 110 minutes, 2 parts of pentaerythritol tetrakisthioglycolate, 0.4 part of ABN-E and 12 parts of ethyl acetate were added. After two and a half hours, the conversion of methyl methacrylate reached 85%, the number average molecular weight Mn of the produced polymer was 1.1 × 10 ⁴ , and the molecular weight distribution (Mw / M
n) was 1.9, and the glass transition temperature Tg was 90 ° C.
From the determination of the mercapto group, 72 mol% of the mercapto group in the added pentaerythritol tetrakisthioglycolate was consumed. Therefore, the polymer portion (MMA /
The number of branches of AA) was 2.88 on average (4 × 0.72 =), and the number average molecular weight was (1.1 × 10 ⁴ /2.88).
≒) It was found to be 3,800. Subsequently, butyl acrylate (BA) 693 was added to the reaction solution from a dropping funnel.
, 7 parts of acrylic acid and 650 parts of ethyl acetate were added dropwise over 2 hours. During this time, the internal temperature was 85 ° C. End of dripping 1
After 0 minute and 40 minutes, 0.2 parts of ABN-E and 12 parts of ethyl acetate were added, respectively. After reacting at an internal temperature of 85 ° C. for 1 hour, the reaction was terminated by cooling to room temperature. 100% polymerization rate
Met. Volatile components such as ethyl acetate and residual monomers were volatilized and removed from the thus obtained reaction solution using a twin-screw extruder to obtain a fluorescent white polymer.

The polymer has tackiness, and Mn =
3.20 × 10 ⁴ , Mw / Mn = 3.8, Tg = −45
° C and 90 ° C. Polymer part (MMA / AA)
Weight ratio of the polymer part (MMA / BA / AA) [P
(MMA / AA): P (MMA / BA / AA)]
(300 × 0.85): (300 × 0.15 + 700)
= 255: 745 = 25.5: 74.5. This polymer was used as a hot-melt pressure-sensitive adhesive (1), and its properties were measured by the following methods. The results are shown in Table 1.

Viscosity at 180 ° C .: 18 hot melt adhesives
It was melted by heating to 0 ° C. and measured by a flow tester (manufactured by Shimadzu Corporation). 180 ° peel: Hot melt adhesive was applied with a GPD coater (Yuri Roll Machine Co., Ltd.) to a coating thickness of 25 μm.
Is melt-coated on a PET film so as to have a width of 25 mm, and is adhered to stainless steel (SUS) as an adherend.
The PET film was peeled at 180 ° from the stainless steel at a tensile speed of mm / min, and the strength was measured.

Ball tack: J.I. The measured values obtained by the Dow method under the conditions of an inclination angle of 30 ° and a run length of 10 cm are shown. Holding force: A PET film coated with a hot-melt pressure-sensitive adhesive is applied to a stainless steel plate with an adhesive area of 25 mm x 25 mm, and reciprocally pressed with a 2 kg roller for one hour at predetermined temperatures (40 ° C, 80 ° C). After heating, the time until falling with a load of 1 kg or 2
The displacement (unit: mm) after 4 hours was measured.

Example 2 The same apparatus as in Example 1 was used except that methyl methacrylate 380 was used.
And 330 parts of ethyl acetate. Inner temperature is 83 ° C
Reached, 4 parts of dipentaerythritol hexakisthioglycolate, 0.8 parts of ABN-E, 25 parts of ethyl acetate
And the polymerization was started. 80 minutes and 110 minutes after the initiation of polymerization, 2 parts of pentaerythritol tetrakisthioglycolate, 0.4 part of ABN-E, and 12 parts of ethyl acetate were added. Two and a half hours later, when the conversion reached 85%, 620 parts of butyl acrylate and 595 parts of ethyl acetate were added dropwise over 2 hours. Ten minutes and 40 minutes after the completion of the dropping, 0.2 parts of ABN-E and 12 parts of ethyl acetate were added. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. The polymerization rate was 100%. Volatile components are removed from the obtained reaction solution using a twin screw extruder,
A fluorescent white polymer was obtained. The polymer has tackiness and M
n = 4.1 × 10 ⁴ , Mw / Mn = 3.6, Tg = −4
5 ° C and 90 ° C.

The obtained polymer was used as a hot melt pressure-sensitive adhesive (2), and the pressure-sensitive adhesive properties and physical properties of the acrylic polymer are shown in Table 1. -Example 3 By the same operation as in Examples 1 and 2, polymerization was performed with the composition shown in Table 1 to obtain a polymer. The obtained polymer was used as a hot-melt pressure-sensitive adhesive (3), and the pressure-sensitive adhesive properties and acrylic polymer property values are shown in Table 1.

Comparative Example 1 300 parts of styrene and 275 parts of ethyl acetate were added to the same apparatus as in Example 1, and the temperature was raised. After the internal temperature reaches 83 ° C,
Pentaerythritol tetrakisthioglycolate 4
, 0.8 part of ABN-E and 25 parts of ethyl acetate were added to initiate polymerization. 80 minutes and 110 minutes after the initiation of polymerization, respectively, pentaerythritol tetrakisthioglycolate 2
Parts, ABN-E 0.4 parts and ethyl acetate 12 parts.
Two and a half hours later, when the polymerization rate reached 85%, 693 parts of butyl acrylate, 7 parts of acrylic acid, and 68 parts of ethyl acetate were used.
0 parts were added dropwise over 2 hours. Ten minutes and 40 minutes after the completion of the dropping, 0.2 parts of ABN-E and 12 parts of ethyl acetate were added. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. The polymerization rate was 100%. Volatile components were removed from the obtained reaction solution using a twin-screw extruder to obtain a milky white polymer. The polymer has tackiness,
Mn = 3.2 × 10 ⁴ , Mw / Mn = 4.7, Tg = −
45 ° C and 90 ° C.

The obtained polymer was used as a comparative hot melt pressure-sensitive adhesive (1). Table 2 shows the pressure-sensitive adhesive properties and physical properties of the acrylic polymer. Since Comparative Example 1 contains a polystyrene component, the holding power at 40 ° C. is 24 hours or less, and the heat resistance is inferior to Examples 1 to 3. Comparative Example 2 Methyl methacrylate 196 was added to the same apparatus as in Example 1.
Part, acrylic acid 4 parts, azobiscyclohexanecarbonitrile 0.2 part, methyl isobutyl ketone 200 parts, pentaerythritol tetrakisthioglycolate 5.6
The polymerization was performed at 100 ° C. under a nitrogen atmosphere. Two and a half hours later, when the polymerization rate reached 85%, 300 parts of butyl acrylate and 175 parts of 2-ethylhexyl acrylate were used.
And 25 parts of acrylic acid. After a while,
When the internal temperature rose, it was found that the reaction solution became cloudy and the second-stage polymerization was started. After reacting at the reflux temperature for 5 hours, 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization. Volatile components were removed from the obtained polymer using a twin-screw extruder to obtain a fluorescent white polymer. The polymer has tackiness and Mn = 5.6 ×
10 ⁴ , Mw / Mn = 2.4, Tg = −51 ° C. and 9
It was 0 ° C.

The obtained polymer was used as a comparative hot melt pressure-sensitive adhesive (2), and its tackiness and physical properties of the acrylic polymer are shown in Table 2. Comparative Example 2 contained a large amount of 2-ethylhexyl acrylate and had a glass transition temperature of the polymer portion (2) lower than -50 ° C., and thus was inferior in holding power (heat resistance) as compared with Examples 1 to 3. ing.

Comparative Example 3 297 parts of methyl methacrylate were added to a device similar to that of Example 1.
Acrylic acid (3 parts) and ethyl acetate (275 parts) were added, and the mixture was heated to 83 ° C under a nitrogen atmosphere. There 8 parts of pentaerythritol tetrakisthioglycolate, ABN-E0.8
And 25 parts of ethyl acetate were added to initiate polymerization. 80 minutes after the start of polymerization, 0.4 part of ABN-E after 110 minutes,
12 parts of ethyl acetate were added. After two and a half hours, the conversion of methyl methacrylate reached 85%, and the resulting polymer was Mn.
= 0.76 × 10 ⁴ , Mw / Mn = 1.9, Tg = 90
° C. Subsequently, ethyl acrylate 69 was added to the reaction solution.
3 parts, acrylic acid 7 parts and ethyl acetate 650 parts were added dropwise over 2 hours. During this time, the internal temperature was 85 ° C. Ten minutes and 40 minutes after the completion of the dropping, 0.2 parts of ABN-E and 12 parts of ethyl acetate were added. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. Polymerization rate is 10
It was 0%. Volatile components were removed from the reaction solution thus obtained using a twin screw extruder to obtain a fluorescent white polymer. The polymer has no tackiness and Mn = 3.8 ×
10 ⁴ , Mw / Mn = 3.7, Tg = −20 ° C. and 9
It was 0 ° C.

This polymer was used as a comparative hot melt pressure-sensitive adhesive (3), and its adhesive properties and acrylic polymer physical properties are shown in Table 2. In Comparative Example 3, since the glass transition temperature of the polymer portion (2) was higher than -25 ° C, the ball tack was small and the adhesive properties were insufficient.
In addition, the amount of mercapto consumed during the initial polymerization is large, and the production efficiency of the acrylic polymer is reduced, so that the holding power (heat resistance) is inferior to Examples 1 to 3.

-Comparative Example 4-Mn consisting of 100% methyl methacrylate = 10,000
0, Mw / Mn = 1.9, 300 parts of a macromonomer having a methacryloyl group at one end, butyl acrylate 69
3 parts, 7 parts of acrylic acid, 500 parts of ethyl acetate and 5 parts of azobisisobutyronitrile were placed in the same flask as in Example 1, and heated to 70 ° C. under a nitrogen atmosphere. When stirring was continued for 4 hours, the temperature was raised to 80 ° C., and the mixture was aged for 1 hour. Then, 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization.

The thus obtained product was used as a comparative hot melt pressure-sensitive adhesive (4), and its tackiness and physical properties of the graft polymer are shown in Table 2. Comparative Example 4 is Examples 1 to
3 is inferior in holding power (heat resistance). -Comparative Example 5-297 parts of methyl methacrylate was added to the same apparatus as in Example 1,
Acrylic acid (3 parts) and ethyl acetate (275 parts) were added, and the mixture was heated to 83 ° C under a nitrogen atmosphere. There, 6 parts of pentaerythritol tetrakisthioglycolate, ABN-E0.8
And 25 parts of ethyl acetate were added to initiate polymerization. 80 minutes and 110 minutes after the start of polymerization, 3 parts of pentaerythritol tetrakisthioglycolate and ABN-E0.4
And 12 parts of ethyl acetate. After two and a half hours, the conversion of methyl methacrylate reached 85%, the resulting polymer had Mn = 0.76 × 10 ⁴ , Mw / Mn = 1.9, Tg =
90 ° C. Subsequently, 693 parts of butyl acrylate, 7 parts of acrylic acid, and 650 parts of ethyl acetate were added dropwise to the reaction solution over 2 hours. During this time, the internal temperature was 85 ° C. 10 minutes after the completion of dropping, 0.2 part of ABN-E each 40 minutes after the addition,
12 parts of ethyl acetate were added. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. The polymerization rate was 100%. Volatile components were removed from the reaction solution thus obtained using a twin screw extruder to obtain a fluorescent white polymer. The polymer has tackiness and Mn = 2.4 ×
10 ⁴ , Mw / Mn = 3.6, Tg = −45 ° C. and 9
It was 0 ° C.

The polymer was used as a comparative hot melt pressure-sensitive adhesive (5), and the pressure-sensitive adhesive properties and acrylic polymer physical property values are shown in Table 3. Comparative Example 5 is inferior in holding power (heat resistance) because it has a smaller number average molecular weight of 2.4 × 10 ^{4 as} compared with Examples 1 to 3. -Comparative Example 6- 297 parts of methyl methacrylate were added to the same apparatus as in Example 1,
Acrylic acid (3 parts) and ethyl acetate (275 parts) were added, and the mixture was heated to 83 ° C under a nitrogen atmosphere. There, 1.6 parts of pentaerythritol tetrakisthioglycolate, ABN-E0.
Eight parts and 25 parts of ethyl acetate were added to initiate polymerization. 80 minutes and 110 minutes after the start of polymerization, 0.8 parts of pentaerythritol tetrakisthioglycolate and ABN-E
0.4 parts and 12 parts of ethyl acetate were added. After two and a half hours, the conversion of methyl methacrylate reached 85%, and the resulting polymer had Mn = 1.7 × 10 ⁴ , Mw / Mn = 1.7, T
g = 90 ° C. Subsequently, 693 parts of butyl acrylate, 7 parts of acrylic acid, and 650 parts of ethyl acetate were added dropwise to the reaction solution over 2 hours. During this time, the internal temperature was 85 ° C.
10 minutes and 40 minutes after the completion of dropping, respectively, ABN-E0.2
And 12 parts of ethyl acetate. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. The polymerization rate was 100%. Volatile components were removed from the reaction solution thus obtained using a twin screw extruder to obtain a fluorescent white polymer. The polymer has tackiness and Mn = 6.1.
× 10 ⁴ , Mw / Mn = 3.9, Tg = −45 ° C. and 90 ° C.

This polymer was used as a comparative hot-melt pressure-sensitive adhesive (6), and the pressure-sensitive adhesive properties and acrylic polymer physical properties are shown in Table 3. In Comparative Example 6, although the holding power was satisfactory, the viscosity at 180 ° C. was 900 poise, which was at least three times higher than those in Examples 1 to 3, and was inferior in hot melt workability. -Comparative Example 7- In a device similar to that of Example 1, methyl methacrylate was used.
5 parts, 1.5 parts of acrylic acid, 0.6 parts of ABN-E, 100 parts of ethyl acetate and 4 parts of pentaerythritol tetrakisthioglycolate were added, and polymerization was carried out at 100 ° C. under a nitrogen atmosphere. Two and a half hours later, when the conversion reached 85%, 841.5 parts of butyl acrylate and 8.5 parts of acrylic acid were used.
And 825 parts of ethyl acetate. After a while, when the internal temperature increased, it was found that the reaction system became cloudy and the second-stage polymerization was started. After reacting at reflux temperature for 5 hours, methoxyphenol 0.1 as a polymerization inhibitor was added.
Four parts were charged to terminate the polymerization. Volatile components were removed from the obtained polymer using a twin-screw extruder to obtain a fluorescent white polymer. The polymer has tackiness and Mn = 2.
9 × 10 ⁴ , Mw / Mn = 3.6, Tg = −45 ° C. and 90 ° C.

The obtained polymer was used as a comparative hot melt pressure-sensitive adhesive (7), and the pressure-sensitive adhesive properties and acrylic polymer physical property values are shown in Table 4. In Comparative Example 7, since the ratio of polymer (1): polymer (2) = 12.8: 87.2 and the ratio of polymer (1) was small, the holding power (heat resistance) was lower than that of Examples 1 to 3. )
Inferior in terms of.

Comparative Example 8 A device similar to that in Example 1 was used, and methyl methacrylate 445.5 was used.
Parts, 4.5 parts of acrylic acid, and 400 parts of ethyl acetate.
The temperature was raised to 83 ° C. in a nitrogen atmosphere. There, 4 parts of pentaerythritol tetrakisthioglycolate, ABN-E
0.8 parts and 25 parts of ethyl acetate were added to initiate polymerization.
80 minutes and 110 minutes after the start of polymerization, 2 parts of pentaerythritol tetrakisthioglycolate and ABN-E
0.4 parts and 12 parts of ethyl acetate were added. Two and a half hours later, when the conversion reached 85%, 544.5 parts of butyl acrylate, 5.5 parts of acrylic acid, and 5 parts of ethyl acetate were added to the reaction solution.
25 parts were added dropwise over 2 hours. During this time, the internal temperature was 85 ° C. 10 minutes and 40 minutes after the end of dropping, respectively, ABN-
E 0.2 parts and ethyl acetate 12 parts were added. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. The polymerization rate was 100%. Volatile components were removed from the reaction solution thus obtained using a twin screw extruder to obtain a fluorescent white polymer. The polymer has tackiness and M
n = 3.8 × 10 ⁴ , Mw / Mn = 3.9, Tg = −4
5 ° C and 90 ° C.

The polymer was used as a comparative hot melt pressure-sensitive adhesive (8), and the pressure-sensitive adhesive properties are shown in Table 4. Comparative Example 8
Means polymer (1): polymer (2) = 38.3: 61.7
Since the ratio of the polymer (1) is large, both the 180-degree peel strength and the ball tack are small, and the physical properties as a general adhesive are inferior.

Comparative Example 9 The same apparatus as in Example 1 was used, and 297 parts of methyl methacrylate were added.
Acrylic acid (3 parts) and ethyl acetate (275 parts) were added, and the mixture was heated to 83 ° C under a nitrogen atmosphere. There 4 parts of trimethylolpropane tris (thioglycolate), ABN-E0.8
And 25 parts of ethyl acetate were added to initiate polymerization. 80 minutes and 110 minutes after the start of polymerization, 2 parts of trimethylolpropane tris (thioglycolate), ABN-E0.4
And 12 parts of ethyl acetate. Two and a half hours later, when the conversion reached 85%, butyl acrylate 6 was added to the reaction solution.
93 parts, acrylic acid 7 parts and ethyl acetate 650 parts were added dropwise over 2 hours. During this time, the internal temperature was 85 ° C. Ten minutes and 40 minutes after the completion of the dropping, 0.2 parts of ABN-E and 12 parts of ethyl acetate were added. Thereafter, the polymerization was continued for 1 hour, and then cooled to room temperature to terminate the reaction. The conversion is 1
00%. Volatile components were removed from the reaction solution thus obtained using a twin screw extruder to obtain a fluorescent white polymer. The polymer has tackiness, and Mn = 2.8 × 1
0 ⁴ , Mw / Mn = 3.5, Tg = -45 ° C and 90
° C.

The polymer was used as a comparative hot melt pressure-sensitive adhesive (9), and its pressure-sensitive adhesive properties are shown in Table 4. Comparative Example 9
Have a small number average molecular weight of 2.8 × 10 ⁴ and the polyvalent mercaptan is trivalent, and
, The holding power (heat resistance) is inferior.

[0292]

[Table 1]

[0293]

[Table 2]

[0294]

[Table 3]

[0295]

[Table 4]

Example 4 Each of the hot melt pressure-sensitive adhesives (1) to (3) obtained in Examples 1 to 3 was allowed to stand in a hot-air circulating oven at 180 ° C. for 5 hours. The 180 ° C. viscosity was measured. The hot melt pressure-sensitive adhesives (1) to (3) have a 180 ° C viscosity ratio before and after heating (viscosity after heating / before heating) of 1.0 to 1.1, respectively, and have particularly good thermal stability. It was confirmed that there was. Table 5 shows the results of the viscosity measurement before and after heating.

Comparative Example 10 As a comparative hot melt pressure-sensitive adhesive (10), butyl acrylate / acrylic acid = 95/5, Mn = 28.0
Viscosity was measured under the same conditions as in Example 3 using a polymer obtained by further metal-crosslinking a linear polymer having Mw / Mn = 2.1 with zinc. This metal crosslinked polymer is
The viscosity after heating was 3.6 times the viscosity before heating, confirming poor thermal stability of the generally-known metal crosslinked polymer. Table 5 shows the results of the viscosity measurement before and after heating.

Comparative Example 11 As a comparative hot melt pressure-sensitive adhesive (11), SIS (Mw of styrene portion is 9.8 × 10 ³ , M of isoprene portion is M
w is 120 × 10 ³ ) 100 parts and YS Polystar S-145 (manufactured by Yashara Chemical), which is a tackifying resin, is 10
0 parts and butylhydroxytoluene 2 which is an antioxidant
The viscosity was measured under the same conditions as in Example 3 using a rubber-based hot melt pressure-sensitive adhesive consisting of This rubber-based hot melt adhesive has a viscosity after heating that is about 1/100 of the viscosity before heating.
It was confirmed that the thermal stability was poor. Table 5 shows the results of the viscosity measurement before and after heating.

[0299]

[Table 5]

Next, Examples and Comparative Examples in which the pressure-sensitive adhesive composition of the present invention is the pressure-sensitive adhesive composition of the first and second embodiments will be described. Example 2-1 Methyl methacrylate was placed in a 1.5-liter four-necked flask equipped with a Max Blend blade (manufactured by Sumitomo Heavy Industries, Ltd.) equipped with a nitrogen inlet tube, a dropping funnel, a thermometer, and a cooling tube. (MMA) 247 parts, hydroxyethyl acrylate (HEA) 3 parts and ethyl acetate 230 parts were added, and the temperature was raised to 83 ° C. under a nitrogen atmosphere. Inner temperature is 83 ° C
And 2.5 parts of dipentaerythritol hexakisthioglycolate, a hexavalent mercaptan, 2,
2'-azobis (2-methylbutyronitrile) (ABN
-E, manufactured by Nippon Hydrazine Industry Co., Ltd.) (0.8 parts) and ethyl acetate (10 parts) were added to initiate polymerization.

70 minutes and 100 minutes after the start of polymerization, dipentaerythritol hexakisthioglycolate was added.
5 parts, 0.4 part of ABN-E and 5 parts of ethyl acetate were added. 140 minutes after the start of the polymerization, the conversion of methyl methacrylate reached 83%, the number average molecular weight Mn of the produced polymer was 1.3 × 10 ⁴ , the molecular weight distribution (Mw / Mn) was 1.9,
Glass transition temperature was 90 ° C. From the determination of the mercapto group, 70 mol% of the mercapto group in the added dipentaerythritol hexakisthioglycolate was consumed. Accordingly, the number of branches of the polymer portion (MMA / HEA) is 4.2 on average (6 × 0.7 =), and the number average molecular weight is (1.3 × 10 ⁴ /4.2≒)3, It turned out to be 100.

Subsequently, 738 parts of butyl acrylate, 12 parts of HEA, and 74 parts of ethyl acetate were dropped from the dropping funnel into the reaction solution.
0 parts were added dropwise over 2 hours. During this time, the internal temperature was 85 ° C. Ten minutes, 40 minutes, and 70 minutes after the completion of dropping, 0.2 parts of ABN-E and 5 parts of ethyl acetate were added, respectively. Inner temperature 8
After reacting at 5 ° C. for 90 minutes, the reaction was cooled to room temperature to complete the reaction. The polymerization rate was 100%.

The obtained pressure-sensitive adhesive solution had a nonvolatile content of 5%.
It was a 0.1% fluorescent white viscous liquid having a viscosity of 3,500 cps at 25 ° C. For packaging tape, apply on PET film so that the dry coating thickness is 25 μm,
Dry at 100 ° C. for 2 minutes. 180 ° peel, ball tack, holding power (stainless steel, cardboard),
Table 6 shows the evaluation results of the cardboard sealability.

The pressure-sensitive adhesive of Example 2-1 was found to be excellent in holding power even without using a crosslinking agent, and was also excellent as a pressure-sensitive adhesive for packaging tapes. 180 °
Peel and ball tack were measured by the methods described above. Holding force is 2 on stainless steel plate or cardboard plate.
Affix the tape with an adhesive area of 5 mm × 25 mm, press and reciprocate with a 2 kg roller once, adjust the temperature at a predetermined temperature (40 ° C, 80 ° C) for 1 hour, and apply a load of 1 kg to drop or The displacement (unit: mm) after 60 minutes was measured and evaluated.

[0305] Corrugated cardboard sealability is 1kg oil can (for 2 pieces)
Set the packing cardboard box and adhesive tape at a predetermined temperature (5 ° C, 40
C)), left overnight in a constant temperature and humidity room set at 50 ° C, sealed with a width of 50 mm, pressed one side of the side with a 1 kg roller, and cut with a cutter knife while leaving the side part at a length of 30 mm.
After 24 hours, tape peeling was observed.ハ indicates that no peeling occurred, and x indicates that peeling occurred. (Comparative Example 2-1) Using the same device as in Example 2-1
The same operation was performed except that dipentaerythritol hexakisthioglycolate was not used to obtain a pressure-sensitive adhesive solution for comparison. The obtained pressure-sensitive adhesive solution had a nonvolatile content of 49.5.
%, A white viscous liquid having a viscosity of 11,000 cps at 25 ° C.

For a packaging tape, the composition was applied on a PET film so as to have a dry applied thickness of 25 μm, and dried at 100 ° C. for 2 minutes. Table 6 shows the evaluation results of 180 ° peel, ball tack, holding power (stainless steel, cardboard), and cardboard sealability. (Comparative Example 2-2) Using the same device as in Example 2-1
289.5 parts of butyl acrylate, 9 parts of acrylic acid, HE
A 1.5 parts and ethyl acetate 300 parts were added, and the temperature was raised to 83 ° C. under a nitrogen atmosphere. ABN-E 2 parts, ethyl acetate 10
And the polymerization was started.

Ten minutes after the start of the polymerization, 675.5 parts of butyl acrylate, 21 parts of acrylic acid, HEA
3.5 parts, 200 parts of ethyl acetate and 500 parts of toluene
It was dropped over time. Ten minutes, 40 minutes, and 70 minutes after the completion of dropping, 0.5 parts of ABN-E and 5 parts of ethyl acetate were added. After reacting at an internal temperature of 85 ° C. for 90 minutes, the reaction was terminated by cooling to room temperature. The polymerization rate was 100%.

The comparative pressure-sensitive adhesive obtained had a nonvolatile content of 4
It was a transparent viscous liquid having a viscosity of 13,000 cps at 9.8% and 25 ° C. Number average molecular weight 3.2 × 10 ⁴ , Mw
/Mn=8.9. The same evaluation as in Example 2-1 was performed, and the results are shown in Table 6.

[0309]

[Table 6]

The pressure-sensitive adhesive of Example 2-1 was excellent in all of holding power, ball tack, and cardboard sealing property.
The comparative pressure-sensitive adhesives of Comparative Examples 2-1 and 2-2 were inferior to those of Example 2-1 in all physical properties except ball tack, and could not be used as packaging tapes. Moreover, in the test of the holding power, the comparative pressure-sensitive adhesive had undergone cohesive failure and remained on the SUS plate. (Example 2-2) In the same apparatus as in Example 2-1, 147.5 parts of methyl methacrylate (MMA) and acrylic acid (A) were used.
A) 1.5 parts, 2-hydroxyethyl acrylate (HE
A) 1.0 part and 140 parts of ethyl acetate were added, and the temperature was raised to 83 ° C. in a nitrogen atmosphere. After the internal temperature reaches 83 ° C, 2 parts of tetravalent mercaptan pentaerythritol tetrakisthioglycolate (PETG), ABN-E0.6
And 10 parts of ethyl acetate were added to initiate polymerization.

90 minutes and 120 minutes after the start of polymerization, P
1 part of ETG, 0.3 part of ABN-E and 5 parts of ethyl acetate were added. 160 minutes after the start of the polymerization, the conversion of MMA reached 85%, and the number average molecular weight of the produced polymer was 1.8 × 1
O ⁴ , molecular weight distribution (Mw / Mn) was 2.0, and glass transition temperature was 91 ° C. From the determination of the mercapto group, 74 mol% of the mercapto group in the added PETG was consumed. Accordingly, the number of branches of the polymer portion (MMA / AA / HEA) is 2.96 on average (4 × 0.74 =), and the number average molecular weight is (1.8 × 10 ⁴ /2.96≒)6. , 100
It turned out to be.

Subsequently, 666 parts of butyl acrylate (BA), 170 parts of 2-ethylhexyl acrylate (2EHA), 8.5 parts of AA, HEA
5.5 parts and 500 parts of ethyl acetate were added dropwise over 2.5 hours. During this time, the internal temperature was 85 ° C. After completion of the dropwise addition, 500 parts of toluene were added over 20 minutes, and ABN-
0.6 part of E and 5 parts of ethyl acetate were added. After reacting at 85 ° C. for 3 hours, the mixture was cooled and Pencel C (polymerized rosin ester manufactured by Arakawa Chemical Co., Ltd., softening point 117 to 12) was used as a tackifier.
7 ° C.) and 100 parts of stiberite ester 10 (hydrogenated rosin ester manufactured by Rika Hercules, softening point 71-78)
(C) 100 parts together with 300 parts of toluene to obtain an adhesive solution having a solid content of 45.2% and a viscosity of 5,600 cps.

One part of Coronate L (an isocyanate compound manufactured by Nippon Polyurethane Co., 75% solids) was mixed with 100 parts of the solid content of the pressure-sensitive adhesive solution, and the thickness after drying on a release paper was 75 μm. And apply 10 sheets
After drying at 0 ° C for 3 minutes, transfer to both sides of
A 0 μm double-sided tape was produced. After curing at 23 ° C. for 7 days, physical properties were measured. The 180 ° peel and the holding power were measured by a conventional method with a 50 μm thick PET stuck on one side. Table 7 shows the results.

The rebound resistance was determined by attaching an aluminum plate having a thickness of 0.4 mm and a width of 20 mm and a length of 180 mm to one side of a double-sided tape and then applying a 2 kg roller to a polystyrene plate having a thickness of 3 mm and a width of 25 mm and a length of 200 mm. 1 reciprocating and bonding, 3
After 0 minutes, bend the polystyrene to 190 mm
The floating (mm) from both ends when left at 0 ° C. for 24 hours was measured. The smaller the value, the better the resilience resistance.
Excellent rebound resistance is useful in applications where flexibility is required.

The pressure-sensitive adhesive of Example 2-2 was excellent in 180 ° peel, holding power, and rebound resistance, and was found to be excellent as a double-sided pressure-sensitive adhesive tape. (Comparative Example 2-3) BA7 was added to the same device as in Example 2-1.
87 parts, 26.5 parts EHA, 10 parts AA, HEA
A mixture 1460 consisting of 6.5 parts and 460 parts of ethyl acetate
300 parts and 200 parts of ethyl acetate were charged. ABN-E1.2
And 10 parts of ethyl acetate were added to initiate polymerization.

Fifteen minutes after the start of the polymerization, the remaining 1,160 parts of the mixture was added dropwise over 2.5 hours. 85 ° C during this time
And the polymerization was continued. After completion of the dropwise addition, 500 parts of toluene
The mixture was added over minutes, and further 1.2 parts of ABN-E and 5 parts of ethyl acetate were added. After reacting at 85 ° C. for 3 hours, the mixture was cooled, and 100 parts of Pencel C and 100 parts of stevelite ester 10 were added as a tackifier together with 450 parts of toluene, and the solid content was 42.5% and the viscosity was 5,800 cps (25
C) was obtained.

A double-sided tape was prepared in the same manner as in Example 2-2 by mixing 1 part of Coronate L with 100 parts of the solid content of this adhesive solution. Example 2-2 had sufficient holding power, but in Comparative Example 2-3, it fell after 60 minutes, and it was considered that coronate L was insufficient. Thus, 2 parts of Coronate L was added and re-evaluated. Table 7 shows the results.

The balance between 180 ° peel, holding power and rebound resistance is generally difficult to achieve, but Coronate L
One part was insufficient in holding power and rebound resistance, and the Coronate L2 part was inadequate in repulsion resistance.

[0319]

[Table 7]

Next, Examples and Comparative Examples in which the pressure-sensitive adhesive composition of the present invention is the pressure-sensitive adhesive compositions of the third and fourth embodiments (high-solid solvent type pressure-sensitive adhesives) will be described. (Example 2-3) In the same apparatus as in Example 2-1, 195 parts of phenyl methacrylate (PhMA) and acrylic acid (A) were added.
A) 2 parts, 3 parts of HEA and 190 parts of ethyl acetate were added, and the mixture was heated to 83 ° C. under a nitrogen atmosphere. After the internal temperature reaches 83 ° C., 9 parts of pentaerythritol tetrakisthioglycolate, which is a tetravalent mercaptan, 0.8 parts of 2,2′-azobisvaleronitrile (AIBN), and 10 parts of ethyl acetate are added to polymerize. Started.

70 minutes and 100 minutes after the start of polymerization, pentaerythritol tetrakisthioglycolate 4.5 was used.
, 0.4 parts of AIBN and 5 parts of ethyl acetate. 140 minutes after the start of the polymerization, the conversion of phenyl methacrylate is 80
% And the number average molecular weight of the produced polymer is 0.5 × 10
^{4. The} molecular weight distribution (Mw / Mn) was 1.8 and the glass transition temperature was 83 ° C.

From the determination of the mercapto group, 70 mol% of the mercapto group in the added pentaerythritol tetrakisthioglycolate was consumed. Therefore, the number of branches of the polymer portion (PhMA / AA / HEA) is average (4
× 0.7 =) 2.8, and the number average molecular weight is (0.5)
× 10 ⁴ /2.8°) 1800.
Subsequently, 780 parts of BA, A
A8 part, HEA12 part, and ethyl acetate 150 part were dripped over 2 hours. During this time, the internal temperature was 85 ° C.

Ten minutes, 40 minutes, and 70 minutes after the completion of the dropwise addition, 0.2 parts of AIBN and 5 parts of ethyl acetate were added, respectively.
After reacting at an internal temperature of 85 ° C. for 90 minutes, toluene 175
The reaction was terminated by adding parts and cooling. Polymerization rate is 10
It was 0%. The obtained pressure-sensitive adhesive solution had a nonvolatile content of 6
It was a 5.0% fluorescent white viscous liquid having a viscosity of 8,800 cps at 25 ° C. Number average molecular weight 1.9 × 10 ⁴ ,
Mw / Mn = 4.5.

[0324] Coronate L5 was added to this adhesive solution.
1.68 parts (an amount based on 100 parts of the solid content of the adhesive solution) of 5E (polyisocyanate compound manufactured by Nippon Polyurethane Co., Ltd .: 55% of solid content) was mixed so that the dry coating thickness was 25 μm on the PET film. Coated and dried at 100 ° C. for 2 minutes. Then, it was cured at 23 ° C. for 7 days.

The evaluation results of 180 ° peel, ball tack, and holding power (stainless steel) of the obtained pressure-sensitive adhesive tape are shown in Table 8. The pressure-sensitive adhesive of Example 2-3 has a high nonvolatile content of 65% and a viscosity at 25 ° C. of 8,800 cps.
It was excellent in machine coatability and excellent in balance of adhesive properties. (Example 2-4) Example 2-3 except that the polymerizable monomer component, the polyvalent mercaptan, and the solvent were changed to those shown in Table 8.
The same operation was repeated to obtain an adhesive solution.

Table 8 shows the evaluation results. (Comparative Example 2-4) A curing agent was added to the comparative pressure-sensitive adhesive obtained in Comparative Example 2-2, and the adhesive properties were evaluated. Table 8 shows the results. Excellent adhesive properties, but with a non-volatile content of 4
Despite its low 9.8% viscosity is 13,000 cp
s. (Comparative Example 2-5) Using a device similar to that of Example 2-1,
229.5 parts of BA, 2-ethylhexyl acrylate (2
EHA) 60 parts, AA 3 parts, HEA 4.5 parts, octyl thioglycolate 7 parts and ethyl acetate 190 parts were added, and the mixture was heated to 83 ° C. under a nitrogen atmosphere. 2 parts of AIBN and 10 parts of ethyl acetate were added to initiate polymerization.

10 minutes after the start of polymerization, BA5 was dropped from the dropping funnel.
30 parts, 2EHA 140 parts, AA7 parts, HEA10.5
And 150 parts of ethyl acetate were added dropwise over 3 hours. 10 minutes, 40 minutes, and 70 minutes after the end of the dropping, AIBN 0.
Two parts and 5 parts of ethyl acetate were added. After reacting at an internal temperature of 85 ° C. for 90 minutes, 175 parts of toluene was added and cooled, and the reaction was terminated. The polymerization rate was 100%.

The obtained pressure-sensitive adhesive solution had a nonvolatile content of 6
It was a clear viscous liquid having a viscosity of 9,900 cps at 4.5% at 25 ° C. Number average molecular weight 2.1 × 10 ⁴ , Mw /
Mn = 3.5. The adhesive obtained in Comparative Example 2-5 was crosslinked with Coronate L55E in the same manner as in Example 2-3, and the adhesive properties were compared. As the comparative pressure-sensitive adhesive, the same amount of Coronate L55E as in Example 2-3 was insufficient in holding power, so about 4 times the amount was used. As a result, the 180 ° peel was extremely small, and the adhesive was inflexible and brittle. (Comparative Example 2-6) Example 2-3 was repeated except that 7 parts of octyl thioglycolate (TGO) was used in place of 18 parts of pentaerythritol tetrakisthioglycolate, which is a tetravalent mercaptan, in Example 2-3. The same operation as described above was repeated to obtain a pressure-sensitive adhesive solution for comparison. Table 8 shows the physical property values. Since the thermoplastic addition polymer of this pressure-sensitive adhesive does not have a block structure, poly (PhMA / AA / H)
EA) and poly (PhMA / BA / AA / HEA) were too separated, resulting in insufficient adhesion and cohesion. (Example 2-5) In the same apparatus as in Example 2-1, a macromonomer of polymethyl methacrylate (number average molecular weight 2,
000) 250 parts, BA728 parts, AA8 parts, HEA1
4 parts, octyl thioglycolate (TGO) 7 parts, AB
0.8 parts of NE and 600 parts of toluene were charged and heated to 83 ° C. After 3 hours from the start of the polymerization, ABN-E
0.2 parts and 5 parts of toluene were added 3 times every 30 minutes to give 9 parts.
Aging was performed for 0 minutes. The polymerization rate was 100%.

The obtained pressure-sensitive adhesive solution had a nonvolatile content of 6
It was a 2.0% fluorescent white viscous liquid having a viscosity of 7,800 cps at 25 ° C. Number average molecular weight 1.9 × 10 ⁴ ,
Mw / Mn = 3.8. Table 8 shows the results of evaluating the physical properties of the pressure-sensitive adhesive in the same manner as in Example 2-3. Example 2
The pressure-sensitive adhesive of No. 5 has a high non-volatile content, a viscosity of 7,800 cps at 25 ° C., and is excellent in mechanical coating properties.
The adhesive properties were also excellent in balance.

[0330]

[Table 8]

1) PMMA macromonomer Mn = 2,0
002) The viscosity was measured at 25 rpm at 30 rpm with a B-type viscometer # 4. 3) Coronate L55E based on 100 parts of adhesive solids
Is added. 4) The probe tack has a load of 100 g, a contact time of 1 second,
It was measured under the conditions of 5 mmφ and 23 ° C.

Hereinafter, Examples and Comparative Examples in which the pressure-sensitive adhesive composition of the present invention is the hot melt resin composition of Embodiments A to L are shown, but the present invention is not limited to the following Examples. In the following, “%” means “% by weight” and “parts” means “parts by weight”. The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) were determined by gel permeation chromatography (GPC) in terms of polystyrene.

The glass transition temperature (Tg) was measured using a differential scanning calorimeter “DSC- manufactured by Perkin Elmer”.
7 ". The parallel light transmittance was measured using a turbidimeter (ND-1001DP, Nippon Denshoku Industries Co., Ltd.) in the thickness direction of a flat plate having a thickness of 3 mm obtained by injection molding the polymer. (Example 3-1) Methacrylic acid was placed in a 1.5-liter four-necked flask equipped with a Max Blend blade (manufactured by Sumitomo Heavy Industries, Ltd.) equipped with a nitrogen inlet tube, a dropping funnel, a thermometer, and a cooling tube. Methyl 196 parts, acrylic acid 4 parts, azobiscyclohexanecarbonitrile 0.2 parts, methyl isobutyl ketone 200 parts, pentaerythritol tetrakisthioglycolate 5.6 parts were added, and the mixture was added under a nitrogen atmosphere.
Polymerization was carried out at 0 ° C. After 2 hours, the conversion of methyl methacrylate reaches 90%, the number average molecular weight Mn of the produced polymer is 1.4 × 10 ⁴ , and the molecular weight distribution (Mw / Mn) is 1.
8. The glass transition temperature Tg was 89 ° C. Subsequently, 300 parts of butyl acrylate was added to the reaction solution from a dropping funnel,
2-ethylhexyl acrylate 175 parts, acrylic acid 2
5 parts were charged at once. After a while, when the internal temperature increased, it was found that the reaction system became cloudy and the second-stage polymerization was started. After reacting at the reflux temperature for 5 hours, 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization. Volatile components such as methyl isobutyl ketone and residual monomers were volatilized and removed from the reaction solution thus obtained using a twin screw extruder to obtain a milky white polymer. The polymer has adhesive strength, Mn = 5.6 × 10 ⁴ ,
Mw / Mn = 2.4, Tg = −51 ° C. and 90 ° C. This polymer is referred to as hot melt resin composition (1).

In Example 3-1, since the polymerization proceeds starting from the mercapto group, the obtained polymer is poly (methacrylic acid) which is a polymer from the first α, β-unsaturated monomer. Methyl / acrylic acid) and the first α, β-
Poly (butyl acrylate / 2-ethylhexyl acrylate / acrylic acid / methyl methacrylate) which is a polymer from a monomer mixture of the remainder of the unsaturated monomer and the second α, β-unsaturated monomer ) Was thought to have a block structure in which the above polymer portion extended up to the number of mercapto groups around the polyvalent mercaptan.

The characteristics of the hot melt resin composition (1) were measured by the following methods, and the results are shown in Table 9. 180 ° C viscosity: The hot melt resin composition was heated to 180 ° C and melted, and measured by a flow tester (manufactured by Shimadzu Corporation). In addition, about 100 poise or less, the result measured with the B-type rotational viscometer is shown.

180 ° peel strength: coating thickness of 25 to 3
The hot-melt resin composition is melt-coated on a commercially available copy paper (basis weight: 60 g) so as to have a thickness of 0 μm, and is stuck to stainless steel (SUS) as an adherend with a width of 25 mm.
After pressing back and forth with a 2 kg roller once, it is 300 mm after 20 minutes.
The copy paper was peeled from the stainless steel at 180 ° at a pulling rate of / min, and the strength was measured.

Ball tack: J.I. The measured values obtained by the Dow method under the conditions of an inclination angle of 30 degrees and a run length of 10 cm are shown. Holding force: 25mm × on stainless steel (SUS) plate
A commercial copy paper (basis weight 60 g) melt-coated with the hot melt resin composition with an adhesive area of 25 mm was attached and
Press and reciprocate once with a kg roller at a predetermined temperature (40 ° C, 80
C.) for 20 minutes, and a time (unit: mm) until a load of 1 kg was dropped on the copy paper or dropped after 1 hour was measured.

Example 3-2 1.3 parts of zinc acetate was added to 100 parts of the polymer obtained in Example 3-1 and kneaded at 180 ° C. under reduced pressure for 1 hour. Table 9 shows the adhesive properties of the obtained hot melt resin composition (2). (Example 3-3) Polymer 100 obtained in Example 3-1
Styrene petroleum resin (tackifier) FTR6100
30 parts (manufactured by Mitsui Petrochemical Co., Ltd.) were added and kneaded at 180 ° C. for 1 hour. Table 9 shows the adhesive properties of the obtained hot melt resin composition (3).

(Example 3-4) To 100 parts of the polymer obtained in Example 3-1 were added 2.0 parts of zinc acetate and 1.0 part of tributyl phosphate as a phosphoric acid ester.
For 1 hour under reduced pressure. Table 9 shows the adhesive properties of the obtained hot melt resin composition (4). (Example 3-5) 200 parts of styrene and 3 parts of trimethylolpropane trithioglycolate were charged into a nitrogen-purged autoclave and heated to 140 ° C. The polymerization rate after 2 hours reached 91%, and Mn = 1.5 of the produced polymer.
× 10 ⁴ , Mw / Mn = 8.6, Tg = 90 ° C. Subsequently, butadiene 450 was added to the reaction solution under pressure.
, 25 parts of acrylic acid and 25 parts of acrylonitrile were added to proceed with polymerization. After reacting at 140 ° C. for 5 hours, 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization. Volatile components were removed from the obtained reaction solution using a twin screw extruder to obtain a milky white polymer. The polymer shows slight stickiness, Mn = 4.2 × 1
^{0 4, Mw / Mn = 6.8} , Tg = -55 ℃, was 90 ° C..

In Example 3-5, as in Example 3-1, the polymerization proceeds with the mercapto group as a starting point. Therefore, the polymer obtained in Example 3-5 contains the first α, β-
Polystyrene, which is a polymer of unsaturated monomers, and the remainder of the first α, β-unsaturated monomer and the second α, β
-It is easy to imagine that poly (butadiene, acrylic acid, acrylonitrile, styrene), which is a polymer from a monomer mixture with an unsaturated monomer, has a block structure extending radially from a polyvalent mercaptan portion. Was done.

To 100 parts of the polymer, 50 parts of a tackifier (FTR6100 described above) was added and kneaded at 180 ° C. for 1 hour. Table 10 shows the adhesive properties of the obtained hot melt resin composition (5). (Example 3-6) 0.5 part of magnesium acetate was added to 100 parts of the hot melt resin composition (5) obtained in Example 3-5 and kneaded at 180 ° C for 2 hours. Table 10 shows the adhesive properties of the obtained hot melt resin composition (6).

(Example 3-7) To 100 parts of the hot melt resin composition (5) obtained in Example 3-5, 1.0 part of magnesium acetate and 1.0 part of 2-ethylhexyl acid phosphate were added. At 180 ° C. for 2 hours under reduced pressure. Table 10 shows the adhesive properties of the obtained hot melt resin composition (7).

(Example 3-8) In the same apparatus as in Example 3-1, 196 parts of methyl methacrylate, 4 parts of acrylic acid,
200 parts of methyl isobutyl ketone and 5.5 parts of dipentaerythritol hexakisthiopropionate were added, and heated to 100 ° C. under a nitrogen atmosphere. After 30 minutes, the conversion is 3
At 0%, a mixture of 300 parts of butyl acrylate, 175 parts of ethyl acrylate, and 25 parts of methacrylic acid was dropped from the dropping funnel over 3 hours. Thereafter, polymerization was continued for 1 hour, and then 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization. Volatile components were removed from the obtained reaction solution using a twin screw extruder to obtain a transparent polymer. The polymer shows tackiness and M
n = 6.8 × 10 ⁴ , Mw / Mn = 2.4, Tg is −4
A wide value was shown between 0 ° C and 80 ° C. From the polymerization method, the second polymer was obtained from poly (methyl methacrylate / acrylic acid) (methyl methacrylate / acrylic acid = 98/2, weight ratio), which was a polymer from the first α, β-unsaturated monomer. Of poly (butyl acrylate / ethyl acrylate / methacrylic acid) (butyl acrylate / ethyl acrylate / methacrylic acid = 60)
/ 35/5, weight ratio), while the polymerization started from the polyvalent mercaptan while gradually changing the composition, whereby a multivalent mercaptan central star block polymer having a continuous composition change was obtained.

The adhesive properties of the obtained polymer as a hot melt resin composition (8) are shown in Table 11. (Example 3-9) Polymer 100 obtained in Example 3-8
2.0 parts of sodium methoxide, hydrogenated rosin-based tackifier Foral 105 (Rika Hercules Co., Ltd.)
Was added and kneaded under reduced pressure at 180 ° C. for 1 hour.
Table 11 shows the tackiness of the resulting hot melt resin composition (9).

Example 3-10 To 100 parts of the polymer obtained in Example 3-8, 3.0 parts of zinc acetate and 2.0 parts of 2-ethylhexyl acid phosphate were added, and the mixture was heated at 180 ° C. for 1 hour. The mixture was kneaded under reduced pressure for hours. Hot melt resin composition (1
Table 11 shows the adhesive properties of 0). (Example 3-11) 200 parts of vinyl acetate, 150 parts of butyl acrylate, 300 parts of butyl acetate, and 4.0 parts of pentaerythritol tetrakisthioglycolate were added to the same apparatus as in Example 3-1. Heated to 100 ° C. At a polymerization rate of 10%, 335 parts of styrene,
A mixture consisting of 15 parts of acrylonitrile was dropped from the dropping funnel over 3 hours. Thereafter, polymerization was continued for 1 hour, and then 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization. After adding and mixing 3 parts of an antioxidant (Sumilizer BP101, manufactured by Sumitomo Chemical Industries, Ltd.) to the reaction solution thus obtained, volatile components were removed with a twin-screw extruder. The obtained polymer was transparent in fluorescent color, Mn = 5.1 × 10 ⁴ , Mw / Mn = 5.8, Tg.
= A wide value was shown between -10 ° C and 90 ° C.

According to the polymerization technique, poly (vinyl acetate / butyl acrylate) (vinyl acetate / butyl acrylate = 57/43, a polymer derived from the first α, β-unsaturated monomer)
Weight ratio) to poly (styrene / acrylonitrile) (styrene / acrylonitrile = 96/4, weight ratio) which is a polymer from the second α, β-unsaturated monomer while gradually changing the composition. The polymerization started from the mercaptan, and a polyvalent mercaptan central star block polymer having a continuous composition change was obtained.

The resulting polymer was designated as hot melt resin composition (11). Its viscosity at 180 ° C. and peel strength are shown in Table 12. The 180 ° C viscosity was measured by the method described above, and the peel strength was measured by the following method. Peel strength: SPCC steel plate (0.5 mm x 25 mm x 15
(0 mm), the hot melt resin composition was heated and melted so as to have a film thickness of 20 to 30 μm, and the same steel sheet was quickly placed thereon, and pressed back and forth with a 2 kg roller once. After adjusting the temperature at a predetermined temperature (0 ° C., 25 ° C., 50 ° C.) for 20 minutes, the shear peel strength was measured at a tensile speed of 50 mm / min.

(Example 3-12) In the same apparatus as in Example 3-1, 200 parts of vinyl acetate and 136 butyl acrylate were used.
Parts, 2-methacryloyloxyethyl acid acid phosphate (manufactured by Kyoeisha Resin Co., Ltd.), 14 parts, butyl acetate 200
And 5.6 parts of pentaerythritol tetrakisthioglycolate, and heated to 100 ° C. under a nitrogen atmosphere. When the polymerization rate was 20%, a mixture consisting of 335 parts of styrene and 15 parts of acrylonitrile was dropped from the dropping funnel over 3 hours.

The thus obtained reaction solution was added to an antioxidant (S
After adding and mixing 3 parts of Umilizer BP101) and 7 parts of zinc acetate, volatile components were removed with a twin-screw extruder. The obtained hot melt resin composition (12) was transparent in fluorescent color, and the polymer before adding zinc acetate had Mn = 4.0 ×.
10 ⁴ , Mw / Mn = 4.8, and Tg = −8 ° C. to 89 ° C., showing a wide range of values.

The adhesive properties of the hot melt resin composition (12) are shown in Table 12. (Example 3-13) 1.5 parts of 1-ethylhexyl acid phosphate was added to 100 parts of the resin composition (12) obtained in Example 3-12, and kneaded at 180 ° C for 1 hour. Table 12 shows the adhesive properties of the obtained hot melt resin composition (13).

Example 3-14 Mn composed of butyl acrylate / acrylic acid = 95/5, Mn = 10,000, Mw
/ Mn = 1.9 500 parts of a macromonomer having a methacryloyl group at one end, 500 parts of ethyl acetate, and 5 parts of azobisisobutyronitrile were placed in a flask similar to that in Example 3-1 and heated to 70 ° C under a nitrogen atmosphere. Heated. When stirring was continued for 4 hours, the temperature was raised to 80 ° C., and the mixture was aged for 1 hour. Then, 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization.

The volatile component was removed from the reaction solution thus obtained using a twin screw extruder to obtain a transparent polymer. The polymer has adhesive strength, Mn = 6.9 × 10 ⁴ , M
w / Mn = 3.5 and Tg = −50 ° C. Since the polymerization was performed only with the macromonomer, it was understood that the polymer had a highly branched structure.

To 100 parts of this polymer, zinc acetate was added.
0 parts and 2.0 parts of 2-ethylhexyl acid phosphate were added and kneaded under reduced pressure at 180 ° C. for 2 hours. Table 13 shows the adhesive properties of the hot melt resin composition (14) thus obtained. (Example 3-15) To a device similar to that in Example 3-1 was added 425 parts of butyl acrylate, 50 parts of ethyl acrylate, and 30% of a mixed solution of 25 parts of acrylic acid, and 250 parts of ethyl acetate and toluene were added. 250 parts and azobisisobutyronitrile 2.5 parts were added, and polymerization was carried out at 70 ° C. under a nitrogen atmosphere.

Twenty minutes after the start of the polymerization, the dropping of the monomer mixture was started, and was completed in three hours. After completion of the dropwise addition, 1 part of azobisisobutyronitrile was charged, and polymerization was carried out for 1 hour. Then, 0.14 part of methoxyphenol was charged to terminate the polymerization. Volatile components were removed from the reaction solution thus obtained using a twin screw extruder to obtain a transparent polymer. The polymer has adhesive strength, Mn = 3.9 × 10 ⁴ , Mw / Mn = 7.
9, Tg = −45 ° C.

To 100 parts of this polymer was added 1 part of zinc acetate.
3 parts and 1.3 parts of 2-ethylhexyl acid phosphate were added and kneaded under reduced pressure at 180 ° C. for 2 hours. Table 13 shows the adhesive properties of the hot melt resin composition (16) thus obtained. (Comparative Example 3-1) To a device similar to that in Example 3-1 was added 425 parts of butyl acrylate, 50 parts of ethyl acrylate, and 50% of a mixed solution composed of 25 parts of acrylic acid.
00 parts and 1.5 parts of azobisisobutyronitrile were added, and polymerization was carried out at 70 ° C. in a nitrogen atmosphere. Start of polymerization 20
After a minute, the dropping of the monomer mixture was started and completed in 2 hours.
After completion of the dropwise addition, 1 part of azobisisobutyronitrile was added, and polymerization was carried out for 1 hour. Then, 0.14 part of methoxyphenol was added to terminate the polymerization.

The volatile components were removed from the thus obtained reaction solution using a twin screw extruder to obtain a transparent polymer. The polymer has an adhesive force, Mn = 7.8 × 10 ⁴ ,
Mw / Mn = 3.5 and Tg = −46 ° C. This polymer was used as a comparative hot melt resin composition (1), and its adhesive properties are shown in Table 13.

(Comparative Example 3-2) A transparent polymer was obtained by repeating the procedure of Comparative Example 3-1 except that the polymerization temperature was changed to 60 ° C. The polymer has adhesive strength, and Mn = 9.5 ×
10 ⁴ , Mw / Mn = 3.3, Tg = −46 ° C. This polymer was used as a comparative hot melt resin composition (2).
The adhesive properties are shown in Table 13.

(Comparative Example 3-3) To 100 parts of the carboxyl group-containing polymer obtained in Example 3-15, 1.0 part of zinc acetate was added and kneaded under reduced pressure at 180 ° C. for 2 hours. A melt resin composition (3) was obtained. Table 13 shows the adhesive properties. (Comparative Example 3-4) To 100 parts of the polymer having a branched structure (without zinc acetate) obtained in Example 3-14, 30 parts of a tackifier (FTR6100 described above) was added, and the mixture was heated at 180 ° C.
For 1 hour. Table 13 shows the adhesive properties of the comparative hot melt resin composition (4) thus obtained.

(Comparative Example 3-5) In the same apparatus as in Example 3-1, 196 parts of methyl methacrylate, 4 parts of acrylic acid, 200 parts of methyl isobutyl ketone, and 2.0 parts of octyl thioglycolate were added, and a nitrogen atmosphere was added. Heat to below 100 ° C. Thirty minutes later, when the conversion reached 3%, a mixture of 300 parts of butyl acrylate, 175 parts of ethyl acrylate, and 25 parts of methacrylic acid was dropped from the dropping funnel over 3 hours. Thereafter, polymerization was continued for 1 hour, and then 0.14 parts of methoxyphenol as a polymerization inhibitor was added to terminate the polymerization.

The volatile component was removed from the reaction solution using a twin screw extruder to obtain a milky white polymer. The polymer shows tackiness, Mn = 6.5 × 10 ⁴ , Mw / Mn = 2.6, T
g showed a wide value between -40 ° C and 80 ° C. The composition of the polymer thus obtained changed continuously, and its performance is shown in Table 11 as a comparative hot melt resin composition (5).

(Comparative Example 3-6) 2.0 parts of sodium methoxide and a hydrogenated rosin-based tackifier (described above) were added to 100 parts of the polymer having a continuously changing composition obtained in Comparative Example 3-4. Foral 105) (20 parts) was added and kneaded under reduced pressure at 180 ° C. for 1 hour. Table 11 shows the physical properties of the obtained comparative hot melt resin composition (6).

Comparative Example 3-7 300 parts of butyl acetate was charged into the same apparatus as in Example 3-1.
Part, butyl acrylate 136 parts, 2-methacryloyloxyethyl acid phosphate 14 parts, styrene 335
, A mixture consisting of 15 parts of acrylonitrile and 2.0 parts of octyl thioglycolate was placed in a dropping funnel. 200 parts were added from the dropping funnel and heated to 100 ° C. under a nitrogen atmosphere. Twenty minutes after the start of polymerization, the mixture was added from a dropping funnel to 3
It was dropped over time. After completion of the dropwise addition, polymerization was continued for 1 hour, and then 0.14 parts of methoxyphenol as a polymerization inhibitor was added to stop the polymerization.

To the reaction solution thus obtained, 3 parts of an antioxidant (Sumilizer BP101 described above) and 7 parts of zinc acetate were added and mixed, and volatile components were removed by a twin screw extruder. The obtained polymer was fluorescent color transparent and Mn = 4.
5 × 10 ⁴ , Mw / Mn = 6.5, Tg = 42 ° C. The obtained polymer was used as a comparative hot melt resin composition (7), and the adhesive strength was shown in Table 12.

(Comparative Example 3-8) A monomer mixture comprising 300 parts of butyl acrylate, 175 parts of 2-ethylhexyl acrylate, 29 parts of acrylic acid, and 196 parts of methyl methacrylate was prepared in the same apparatus as in Example 3-1. 50% of the amount
740 parts of ethyl acetate, azobisisobutyronitrile
Five parts were added and polymerization was started at 70 ° C. under a nitrogen atmosphere. Twenty minutes after the start of the polymerization, dropping of the remaining monomer mixture was started and was completed in two hours. After completion of the dropwise addition, 1 part of azobisisobutyronitrile was charged, and polymerization was carried out for 1 hour. Then, 0.14 part of methoxyphenol was charged to terminate the polymerization.

[0365] A volatile polymer was removed from the thus obtained reaction solution by using a twin screw extruder to obtain a transparent polymer. The polymer has a weak adhesive strength, Mn = 6.2 × 10
⁴ , Mw / Mn = 4.5, Tg = -11 ° C. This polymer was used as a comparative hot melt resin composition (8),
The adhesive properties are shown in Table 9.

Comparative Example 3-9 200 parts of styrene, 450 parts of butadiene, 25 parts of acrylic acid, 25 parts of acrylonitrile and 1 part of octyl thioglycolate were added to the same apparatus as in Example 3-5. Until heated. After a polymerization reaction under these conditions for 7 hours, volatile components were removed in the same manner as in Example 3-5 to obtain a polymer.

The polymer showed slight tackiness and Mn =
3.9 × 10 ⁴ , Mw / Mn = 3.9, Tg = −24 ° C.
Met. A tackifier (FTR6
100) and kneaded at 180 ° C. for 1 hour.
Table 10 shows the adhesive properties of the obtained comparative hot melt resin composition (9).

[0368]

[Table 9]

[0369]

[Table 10]

[0370]

[Table 11]

[0371]

[Table 12]

[0372]

[Table 13]

Hereinafter, the pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive composition according to embodiments α to γ, and examples of pressure-sensitive adhesive products according to embodiments δ to ε using these pressure-sensitive adhesive compositions are described. Will be described with reference to the drawings. FIG. 1 shows one of the adhesive products of the present invention.
It is sectional drawing of an Example. This pressure-sensitive adhesive product is a double-sided pressure-sensitive adhesive tape 5 and includes a support 1, a pressure-sensitive adhesive layer 2 for soft PVC, and a separator 3.

The pressure-sensitive adhesive layer for flexible PVC is formed of an acrylic cross-linked copolymer (crosslinked from an acrylic block polymer) produced by a production method including a step of drying and cross-linking the pressure-sensitive adhesive composition of the present invention. ) Are formed on both surfaces of the support 1. The separator 3 is, for example, release paper, and is attached to one surface of the soft PVC adhesive layer 2 so as to cover one surface thereof. One surface of the pressure-sensitive adhesive layer 2 is a surface opposite to the one surface attached to the support 1.

The support is, for example, a conventionally known paper, plastic film, foam sheet, nonwoven fabric or the like. In the adhesive product of the present invention, the support can be a flexible polyvinyl chloride molded article (for example, a film, a sheet, a tape, or a wallpaper). FIG. 2 shows another example of the adhesive product of the present invention.
It is sectional drawing of an Example. This adhesive product is a coreless double-sided pressure-sensitive adhesive tape (double-sided pressure-sensitive adhesive tape without a support) 6, which has a pressure-sensitive adhesive layer 2 for soft PVC and a separator 3.

The pressure-sensitive adhesive layer 2 for flexible PVC is formed of an acrylic cross-linked copolymer (crosslinked from an acrylic block polymer) prepared by a production method including a step of drying and cross-linking the pressure-sensitive adhesive composition of the present invention. ) As the main agent. The separator 3 is, for example, release paper, and is attached to both sides of the soft PVC adhesive layer 2 so as to cover both sides. FIG.
FIG. 2 is a sectional view of another embodiment of the pressure-sensitive adhesive product of the present invention.
This adhesive product has an adhesive layer 2 for soft PVC, a separator 3 and a substrate 4.

The pressure-sensitive adhesive layer 2 for flexible PVC is formed of an acrylic cross-linked copolymer (crosslinked from an acrylic block polymer) prepared by a production method including a step of drying and cross-linking the pressure-sensitive adhesive composition of the present invention. ) As the main agent. The separator 3 is, for example, release paper, and is attached to one surface of the soft PVC adhesive layer 2 so as to cover one surface thereof.
The base material 4 is a soft polyvinyl chloride base material (eg, film, sheet, tape, wallpaper).

FIG. 4 is a sectional view of another embodiment of the adhesive product of the present invention. This pressure-sensitive adhesive product has a pressure-sensitive adhesive layer 2 for soft PVC, a separator 3 and a substrate 7. The pressure-sensitive adhesive layer for soft PVC is an acrylic cross-linked copolymer (cross-linked acrylic block polymer) produced by a production method including a step of drying and cross-linking the pressure-sensitive adhesive composition of the present invention.
As a main ingredient. The separator 3 is, for example, release paper, and is attached to one surface of the soft PVC adhesive layer 2 so as to cover one surface thereof. The base material 7 is, for example, a sheet of amimifoil; a polyolefin sheet such as polyethylene or polypropylene.

Hereinafter, specific examples of the present invention will be described together with comparative examples, but the present invention is not limited to the following examples. In the following Examples and Comparative Examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively. [Production of pressure-sensitive adhesive composition]-Example A11-200 parts of styrene and 1.0 part of pentaerythritol tetrakisthioglycolate (PETG) were measured with a thermometer, a stirrer, and a Max blend blade (manufactured by Sumitomo Heavy Industries, Ltd.). ,
The mixture was charged into a 2 liter four-necked flask equipped with an inert gas inlet tube, a reflux condenser and a dropping funnel, and polymerized at 140 ° C. under a nitrogen atmosphere. Three hours later, 760 parts of butyl acrylate and 40 parts of acrylic acid were added all at once. After a while, when the internal temperature rose, it was found that the reaction mixture became cloudy and the second-stage polymerization was started. The polymerization rate after reacting at the reflux temperature of the monomer for 5 hours was 99.4%. The residual monomer was removed under reduced pressure, and 1300 parts of toluene was added to the reaction mixture to dissolve it, and the solid content was 36.4.
%, And a solution of an acrylic copolymer having a viscosity of 17,200 cps was obtained.

Examples A12 to A14 and Comparative Example A1
1- Solution of acrylic copolymer having solid content, viscosity, and weight average molecular weight shown in Table 14 by repeating the procedure of Example A11 except that reaction raw materials and / or reaction conditions were changed as shown in Table 14. I got

[0381]

[Table 14]

-Example B11- Coronate L55E (a polyisocyanate compound manufactured by Nippon Polyurethane Co., Ltd .: solid content 55) was added to the acrylic copolymer solution (solid content 100 parts) obtained in Example A11.
%) Was mixed to prepare a pressure-sensitive adhesive composition. -Examples B12 to B18 and Comparative Examples B11 to B12-Table 15-
Except for having changed as shown in No. 16, the operation of Example B11 was repeated to prepare a pressure-sensitive adhesive composition.

Example C11 The pressure-sensitive adhesive composition obtained in Example B11 was applied to one side of release paper (manufactured by Fujimori Industries Co., Ltd .: 70K-818T / EF) so that the thickness after drying was 50 μm. And then 100 ° C
And cured at 23 ° C. for 7 days. afterwards,
A 50 μm thick flexible polyvinyl chloride sheet (manufactured by Okamoto Co., Ltd.) is overlaid on one side and pressurized, and the pressure-sensitive adhesive composition is transferred to one side of the flexible polyvinyl chloride sheet to form a flexible polyvinyl chloride adhesive sheet (with release paper). Obtained.

Examples C12 to C18 and Comparative Example C1
1-C12- The procedure of Example C11 was repeated except that the pressure-sensitive adhesive composition was changed as shown in Tables 15 and 16, to produce a soft PVC pressure-sensitive adhesive sheet. -Comparative Example D11-A commercially available double-sided tape for soft PVC (a double tack tape # 577 manufactured by Sekisui Chemical Co., Ltd.) was prepared for comparison.

Comparative Example D12 A commercially available double-sided tape for flexible PVC (double-sided adhesive tape No. 501M manufactured by Nitto Electric Industrial Co., Ltd.) was prepared for comparison. -Comparative Example D13-A commercially available double-sided tape for flexible PVC (trade name: Double-sided adhesive tape No. 5000CX, manufactured by Nitto Electric Industrial Co., Ltd.) was prepared for comparison.

In the table, TETRAD-C is 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane manufactured by Mitsubishi Gas Chemical Company. For the flexible PVC adhesive sheet and double-sided tape obtained in the examples and comparative examples, the holding power and the adhesive power were measured according to JIS-Z0237 (1991), and the results are shown in Tables 15 and 16.

The holding force was a stainless steel plate (SUS30
4) A 20 mm × 20 mm pressure-sensitive adhesive sheet is stuck thereon, and the temperature is kept at 80 ° C. 20 minutes after the sticking, and a time of falling after applying a load of 1 kg after 20 minutes, or
It was indicated by the magnitude of the deviation measured 24 hours after the application of the load. The adhesive strength of the pressure-sensitive adhesive sheet was shown by an initial value and a value after heating promotion. The initial value is a 25 mm wide adhesive sheet placed on an aluminum plate (JI) in an atmosphere of 23 ° C. and 65% RH.
SA1050P: 1 mm in thickness), a 2 kg rubber roller was reciprocated once and bonded together, and after 25 minutes, the strength when peeled at a speed of 300 mm / min in a 180-degree direction was measured. After heating, the adhesive sheet was left in an atmosphere of 80 ° C. for 3 days, further left in an atmosphere of 23 ° C. and 65% RH for 2 hours, cut into a 20 mm width, and cut on an aluminum plate.
A rubber roller having a weight of 3 kg was reciprocated three times to be bonded, and after 24 hours, the strength at the time of peeling at a speed of 300 mm / min in the direction of 180 ° was measured.

The adhesive strength of the double-sided tape was indicated by an initial value and a value after heating was promoted. The initial value is that a PET film subjected to corona discharge treatment is lined from one side of a double-sided tape in an atmosphere of 23 ° C. and 65% RH, and the double-sided tape is cut to a width of 20 mm. Bisheet (Okamoto Co., Ltd., # 480, plasticizer 50 phr, aluminum plate fixed on the back with commercially available double-sided adhesive tape)
2kg rubber roller is reciprocated 3 times and bonded.
After 5 minutes, the strength at the time of peeling in the direction of 180 degrees at a speed of 300 mm / min was measured. The value after the heating was promoted was a double-sided tape backed with a corona-treated PET film and cut to a width of 20 mm, and a soft PVC sheet having a thickness of 2 mm (manufactured by Okamoto Co., Ltd., # 480, 50 phr plasticizer, commercially available back side) Aluminum plate fixed with double-sided adhesive tape)
2kg rubber roller is reciprocated 3 times and stuck together.
Leave in 0 ° C atmosphere for 3 days, then 23 ° C, 65% R
After leaving for 2 hours in an atmosphere of H, the strength at the time of peeling in the direction of 180 degrees at a speed of 300 mm / min was measured.

[0389]

[Table 15]

[0390]

[Table 16]

As can be seen from Tables 14 to 16, the examples of the present invention are suitable for a single-sided adhesive sheet or a double-sided adhesive sheet depending on the molecular weight of the obtained polymer (acrylic graft polymer or acrylic block polymer). Although there is something suitable for adhesive tape, it has excellent initial adhesive strength and suppresses the decrease in cohesive force even for the migration of plasticizer from soft PVC due to accelerated heating,
It can be seen that the adhesive strength is maintained at a considerably higher level than the comparative example.

The glass transition temperature (Tg: K) of the produced acrylic copolymer was determined according to the following equation using the following data. Acrylic acid: 379 (K) Methyl acrylate: 281 (K) Ethyl acrylate: 251 (K) Butyl acrylate: 219 (K) 2-ethylhexyl acrylate: 203 (K) 2-hydroxyethyl acrylate: 258 (K) K) Methyl methacrylate: 378 (K) Vinyl acetate: 305 (K) Acrylonitrile: 398 (K) Styrene: 373 (K)

[0393]

(Equation 1)

[0394]

According to the first aspect, the pressure-sensitive adhesive composition of the present invention comprises a polyvalent mercaptan portion, and a first polymer portion and a second polymer portion radially extending from the polyvalent mercaptan portion. Wherein the first polymer portion comprises a high glass transition type polymer having a glass transition point of 273K or more, and the second polymer portion comprises a low glass transition point having a glass transition point of less than 273K. Since it is made of a point-type polymer, it has excellent adhesiveness and heat resistance. In particular, when a cross-linking agent is not used, the adhesive force does not easily decrease or change over time.

The pressure-sensitive adhesive composition of the present invention comprises a pressure-sensitive adhesive tape (kraft paper, uniaxially oriented polypropylene (OPP), cellophane, soft vinyl chloride resin, polyethylene, cloth, PET,
Substrates such as foam and non-woven fabric are used. Adhesive labels (paper, synthetic paper, soft vinyl chloride resin, OPP, cellophane, polyethylene, PET, etc.) for cardboard sealing, light packaging seal, protection, train, paint masking, double-sided adhesive etc. It is useful for applications such as adhesives for medical use (such as plasters, patches, and transdermal patches).

According to the second embodiment, the pressure-sensitive adhesive composition of the present invention is capable of producing a polyvalent mercaptan and a first α, β-polymer having a high glass transition point having a glass transition point of 273 K or more. A preparing step of preparing a first mixture containing an unsaturated monomer, and radical polymerization of the first α, β-unsaturated monomer starting from a mercapto group of a polyvalent mercaptan to obtain a reaction mixture A first polymerization step and a second α, β
-Adding an unsaturated monomer to the reaction mixture to obtain a second mixture capable of producing a low glass transition point type polymer having a glass transition point of less than 273 K; and adding an unsaturated monomer to the reaction mixture. Since it contains a thermoplastic addition polymer produced by a production method including a second polymerization step of performing radical polymerization, the adhesiveness and heat resistance are excellent, and especially when a crosslinking agent is not used, the adhesive force decreases over time or Hard to change.

According to the third aspect, the pressure-sensitive adhesive composition of the present invention further comprises an organic solvent in which a thermoplastic addition polymer is dissolved and / or dispersed, and has a nonvolatile content of 60 to 80% by weight, Except that the viscosity at 25 ° C. is not more than 20,000 cps, it is the same as the pressure-sensitive adhesive composition of the first or second embodiment, so that it has excellent adhesiveness and heat resistance, and is suitable for environmental problems, energy saving and line speed-up. It is useful as a compatible high solid solvent type adhesive.

According to the fourth aspect, the pressure-sensitive adhesive composition of the present invention has a first polymer portion comprising a high glass transition point type polymer having a glass transition point of 273K or more and a glass transition point of less than 273K. A thermoplastic addition polymer having a second polymer portion comprising a low glass transition point type polymer and an organic solvent in which the thermoplastic addition polymer is dissolved and / or dispersed, and has a nonvolatile content of 60 to 80. % By weight and 2
Since the viscosity at 5 ° C. is 20,000 cps or less, it is excellent in tackiness and heat resistance, and is useful as a high-solid solvent-type pressure-sensitive adhesive that can cope with environmental problems, energy saving, and speeding up of lines.

According to the fifth aspect, the pressure-sensitive adhesive composition of the present invention is the pressure-sensitive adhesive composition according to the first aspect, wherein the first polymer portion has a high glass transition point having a glass transition point of 80 ° C. or higher. The second polymer portion is composed of a low glass transition point type acrylic polymer having a glass transition point of −50 to −25 ° C., and the first polymer portion and the second polymer portion are composed of a point type acrylic polymer portion. The weight ratio with the polymer portion is 20:80 to 35: 6.
5, the thermoplastic addition polymer is 30,000 to 60,
Since it is an acrylic hot-melt adhesive with a number average molecular weight of 000, while maintaining the features of the hot-melt adhesive with low capital investment and energy consumption, hot-melt workability, heat resistance, weather resistance, and melt application Can satisfy all of the thermal stability and tackiness.

According to the sixth aspect, the pressure-sensitive adhesive composition of the present invention is the pressure-sensitive adhesive composition of the fifth aspect, wherein the first polymer portion comprises 90 to 100% by weight of methyl methacrylate units and other polymer A monomer unit comprising 0 to 10% by weight
Polymer portion is methyl methacrylate unit 0-10% by weight,
Since it is composed of 80 to 100% by weight of butyl acrylate unit and 0 to 10% by weight of other polymerizable monomer units, the acrylic hot-melt pressure-sensitive adhesive has good heat resistance, tackiness and weather resistance, and is originally compatible. Excellent in both hot melt workability and heat resistance, which are difficult to perform.

According to a seventh aspect, the pressure-sensitive adhesive composition of the present invention is the pressure-sensitive adhesive composition according to the fifth or sixth aspect,
Since the polyvalent mercaptan moiety is a residue of a 4- to 6-valent mercaptan, the thermoplastic addition polymer has a star-shaped block structure extending radially from the same center, and the effect of entangling between the polymer parts is obtained. And the form change of the phase separation structure can be expected.

According to the eighth aspect, the pressure-sensitive adhesive composition of the present invention is the pressure-sensitive adhesive composition according to any one of the fifth to seventh aspects, wherein the first polymer portion is 2,000 to 6, 000
Has a number-average molecular weight of 3. Thus, sufficient heat resistance can be exhibited, the hot melt viscosity can be kept low while maintaining cohesive force (holding force) during use, and handling becomes excellent. .

According to the ninth aspect, the pressure-sensitive adhesive composition of the present invention comprises a polyhydric mercaptan and a first α ,, which can form a high glass transition point type polymer having a glass transition point of 80 ° C. or higher.
a preparing step of preparing a first mixture containing a β-unsaturated monomer, and radical polymerization of the first mixture by leaving unreacted mercapto groups at 15 to 85 mol% starting from a mercapto group of a polyvalent mercaptan. A first polymerization step of obtaining a reaction mixture by performing the following, and adding a second α, β-unsaturated monomer to the reaction mixture to obtain a low glass transition point type polymer having a glass transition point of −50 to −25 ° C. And a second polymerization step of radically polymerizing the second mixture such that the unreacted mercapto groups are reduced to 2 mol% or less starting from the unreacted mercapto groups. Acrylic hot-melt pressure-sensitive adhesive containing a thermoplastic addition polymer made by the company. , It can be satisfied heat resistance, weather resistance, thermal stability during melt coating, all tacky.

According to the tenth aspect, the pressure-sensitive adhesive composition of the present invention is characterized in that, in the ninth aspect, the first α, β-unsaturated monomer is 90 to 100% by weight of methyl methacrylate and other Consisting of 0 to 10% by weight of a polymerizable monomer;
-0 to 10% by weight of unsaturated monomer is methyl methacrylate,
Since it is composed of 80 to 100% by weight of butyl acrylate and 0 to 10% by weight of other polymerizable monomers, the acrylic hot-melt adhesive has good heat resistance, adhesiveness and weather resistance, and is inherently incompatible. Excellent in both hot melt workability and heat resistance.

According to the eleventh aspect, in the ninth or tenth aspect, the pressure-sensitive adhesive composition of the present invention has the same thermoplastic addition polymer as the polyvalent mercaptan being a 4- to hexavalent mercaptan. It has a star-shaped block structure extending radially from the center, and can be expected to have the effect of entanglement between polymer portions and change in the form of the phase separation structure. According to the twelfth aspect, the pressure-sensitive adhesive composition of the present invention according to the ninth to eleventh aspects, wherein the high glass transition point type acrylic polymer obtained in the first polymerization step is 2,000 to 6, Since it has a number average molecular weight of 000, sufficient heat resistance can be exhibited, the hot melt viscosity can be kept low while maintaining the cohesive force (holding force) during use, and the handleability is excellent. Become.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of the adhesive product of the present invention.

FIG. 2 is a sectional view of one embodiment of the adhesive product of the present invention.

FIG. 3 is a cross-sectional view of one embodiment of the adhesive product of the present invention.

FIG. 4 is a sectional view of one embodiment of the adhesive product of the present invention.

[Description of Signs] 1 support 2 adhesive layer 3 separator 4 substrate 5 double-sided adhesive tape 6 coreless double-sided adhesive tape

Claims (8)

[Claims] 1. A thermoplastic addition polymer having a polyvalent mercaptan portion and a first polymer portion and a second polymer portion extending radially from the polyvalent mercaptan portion, wherein the first polymer portion is A high glass transition point type acrylic polymer having a glass transition point of 80 ° C. or more, wherein the second polymer portion has a glass transition point of −50 to −25 ° C. Consisting of a polymer,
Acrylic resin wherein the weight ratio of the first polymer portion to the second polymer portion is 20:80 to 35:65, and the thermoplastic addition polymer has a number average molecular weight of 30,000 to 60,000. Hot melt adhesive composition. 2. The method according to claim 1, wherein the first polymer portion comprises 90 to 100% by weight of methyl methacrylate units and 0 to 100% of other polymerizable monomer units.
10 to 10% by weight, wherein the second polymer part has a methyl methacrylate unit of 0 to 10% by weight, a butyl acrylate unit of 80 to 100% by weight and another polymerizable monomer unit of 0 to 1%.
The acrylic hot melt pressure-sensitive adhesive composition according to claim 1, comprising 0% by weight. 3. The acrylic hot melt pressure-sensitive adhesive composition according to claim 1, wherein the polyvalent mercaptan moiety is a residue of a tetravalent to hexavalent mercaptan. 4. The method according to claim 1, wherein the first polymer portion is 2,000 to 6.0,
The acrylic hot melt pressure-sensitive adhesive composition according to any one of claims 1 to 3, having a number average molecular weight of 00. 5. A polyhydric mercaptan and a first polymer capable of producing a high glass transition point type polymer having a glass transition point of 80 ° C. or higher.
Preparing a first mixture containing the α, β-unsaturated monomer of the formula (I), and starting from the mercapto group of the polyvalent mercaptan to form an unreacted mercapto group in an amount of 15 to 85 mol%.
A first polymerization step of performing a radical polymerization of the first mixture so as to leave a reaction mixture to obtain a reaction mixture; and adding a second α, β-unsaturated monomer to the reaction mixture, and adding a second α, β-unsaturated monomer at −50 to −25 ° C. An adding step of obtaining a second mixture capable of producing a low glass transition point polymer having a glass transition point; and the second step of reducing the unreacted mercapto group to 2 mol% or less starting from the unreacted mercapto group. Second radical polymerization of the mixture
An acrylic hot-melt pressure-sensitive adhesive composition, which is an acrylic hot-melt pressure-sensitive adhesive containing a thermoplastic addition polymer produced by a production method including a polymerization step. 6. The method according to claim 1, wherein the first α, β-unsaturated monomer comprises 90 to 100% by weight of methyl methacrylate and 0 to 10% by weight of another polymerizable monomer. , Β
-0 to 10% by weight of unsaturated monomer is methyl methacrylate,
The acrylic hot melt pressure-sensitive adhesive composition according to claim 5, comprising 80 to 100% by weight of butyl acrylate and 0 to 10% by weight of another polymerizable monomer. 7. The acrylic hot melt pressure-sensitive adhesive composition according to claim 5, wherein the polyvalent mercaptan is a 4- to 6-valent mercaptan. 8. The acrylic according to claim 5, wherein the high glass transition point type acrylic polymer obtained in the first polymerization step has a number average molecular weight of 2,000 to 6,000. Hot melt adhesive composition.