JP2002338938A - Thermo-sensitive adhesive composition, thermo-sensitive adhesive, thermo-sensitive adhesive laminated body using the adhesive and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermo-sensitive adhesive composition and a thermo- sensitive adhesive with an excellent blocking-resistant property capable of maintaining a high adhesive property for a long period of time when a thermo- sensitive adhesive laminated body is manufactured by coating the thermo- sensitive adhesive on a base material, and to provide the thermo-sensitive adhesive laminated body with a high conductivity of a product, an excellent maintaining property of an adhesive property and a transparency and no generation of blocking even if it is stored for a long period of time and a manufacturing method therefor. SOLUTION: In the thermo-sensitive adhesive composition containing a thermoplastic resin (A) and a solid plasticizer (B), it is characterized that a bis(polyalkylcyclohexyl) phthalate (B1) having a melting point of lower than 100 deg.C and a compound (B2) having a melting point of 100 deg.C or higher are co- used as the solid plasticizer (B). The thermo-sensitive adhesive and the thermo- sensitive adhesive laminated body using the adhesive and the manufacturing method therefor are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive adhesive composition and a heat-sensitive adhesive used for so-called delayed tack labels, a heat-sensitive adhesive laminate using the same, and a method for producing the same. The present invention relates to a heat-sensitive adhesive composition having no tackiness at room temperature and exhibiting tackiness when heated, a heat-sensitive adhesive, a heat-sensitive adhesive laminate using the same, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a label to be applied to a container such as a bottle or a PET bottle, a glue label is applied to a label substrate at the same time as an adhesive is applied, or an adhesive and a release paper are applied to the label substrate. Are sequentially used. However, glue labels require less labor such as management of the viscosity of the pressure-sensitive adhesive and cleaning of a machine for applying the pressure-sensitive adhesive. Also,
Since a large amount of release paper peeled off from the label is generated as garbage, the pressure-sensitive adhesive label on which the release paper is formed is troublesome, and it is not preferable from the viewpoint of resource saving.

As a label for solving such a problem,
A so-called delayed tack label is known. Delayed tack labels are non-adhesive at room temperature, but a layer of a heat-sensitive adhesive that develops adhesiveness upon heating is formed on a label substrate, and no release paper is required.
Moreover, it has an advantage that it can be easily attached to a container only by heating.

A delayed tack label is usually prepared by dispersing solid plasticizer particles and, if necessary, tackifier particles in a binder resin layer having a glass transition temperature of about 0 to 30 ° C. The agent is melted, whereby the binder resin is plasticized to exhibit adhesiveness. As a solid plasticizer, for example, dicyclohexyl phthalate is well known (JP-A-61-9479).
JP, JP-A-7-278521, JP-A-7-17-1
No. 45352, Japanese Patent Application Laid-Open No. 8-333565).

[0005] The delayed tack label as described above is
In recent years, the emulsion-type heat-sensitive adhesive is often applied to the back surface of a substrate and then subjected to a heating step for drying. The heating temperature in that case is required to be a low temperature of 45 ° C. or less so that dicyclohexyl phthalate does not melt and develop adhesiveness at the stage of forming the adhesive layer. However, such low-temperature heating requires a long time for the heating and drying step, and thus has a problem that the productivity of the delayed tack label is reduced. In addition, in the delayed tack label, since no release paper is used, the plastic resin of the binder resin due to dicyclohexyl phthalate gradually occurs when stacked and stored for a long time at a high temperature in summer, for example, and the labels adhere to each other. So-called blocking occurs. For this reason, there is a problem that a cooling device for preventing such blocking is required. Further, the conventional delayed tack label has a problem that the adhesive strength and the transparency are lost in a short period of time.

JP-A-8-325535 discloses that in order to improve blocking resistance, dicyclohexyl phthalate (dicyclohexyl phthalate) having an average particle diameter of 4 μm or less and a melting point of 70 ° C. or more are used as a solid plasticizer. A heat-sensitive adhesive sheet using a solid plasticizer such as N-cyclohexyl-p-toluenesulfonamide having a particle diameter of 4 to 10 μm is disclosed. Japanese Patent Application Laid-Open No. 9-67551 proposes using two or more benzenedicarboxylic acid esters which are solid at 25 ° C. as a solid plasticizer in order to enhance the blocking resistance. Further, in order to improve the blocking resistance and the adhesion, JP-A-11-286667 discloses that 2,2-bis {4- [2] having a melting point of 84 ° C. as a solid plasticizer.
-(M-methylphenoxy) ethoxy] phenyl} propane and the like can be used.
No. 17, the use of 2- [5 ′-(1,1,3,3-tetramethylbutyl) -2′-hydroxyphenyl] benzotriazole having a melting point of 103 ° C. as a solid plasticizer, Proposed. Furthermore, Japanese Patent Application Laid-Open No. 10-17839 discloses a screw-type solid plasticizer having a melting point of 70 to 110 ° C. in order to improve blocking resistance and chalking resistance (loss of adhesive strength). It has been proposed to use hindered phenols.

Japanese Patent Application Laid-Open No. 9-169870 discloses a conventional heat-sensitive delayed-tack type adhesive thermoplastic resin composition which contains a crystal such as tribenzyl trimellitate to improve the balance between blocking resistance and adhesion. A retarder is disclosed. However, even with the use of these solid plasticizers and crystallization retarders, satisfactory results have not always been obtained in terms of blocking resistance, adhesive strength, and durability of transparency.

On the other hand, Japanese Patent Application Laid-Open No. 2000-103969 discloses a thermoplastic resin composition using a specific phosphorus compound as a solid plasticizer in order to obtain a resin having high adhesiveness and excellent blocking resistance. Heat-sensitive adhesive sheets have been proposed. However, this specific phosphorus compound as a solid plasticizer has poor dispersibility in water, that is, poor storage stability, and has problems in handling and quality control. As a result, the thermoplastic resin composition ( There is also a problem that the blocking resistance, adhesive strength, and the like of the heat-sensitive adhesive composition) and the heat-sensitive adhesive are adversely affected.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to perform heat drying at a higher temperature when producing a heat-sensitive adhesive laminate by applying a heat-sensitive adhesive on a substrate. It is another object of the present invention to provide a heat-sensitive adhesive composition and a heat-sensitive adhesive which can maintain high adhesiveness and transparency for a long period of time and have excellent blocking resistance. Another object of the present invention is to
Product productivity is high, adhesiveness and transparency are excellent,
Moreover, it is an object of the present invention to provide a heat-sensitive adhesive laminate which does not cause blocking even when stored for a long period of time, and a method for producing the same.

[0010]

The present inventors have conducted intensive studies to achieve the above object, and as a result, as a solid plasticizer, a bis (polyalkyl phthalate) having an excellent plasticizing effect and a melting point of less than 100 ° C. Cyclohexyl) as a main component,
An experiment was conducted on a mixed solid plasticizer in which various solid plasticizers were blended, and a solid plasticizer having a melting point of 100 ° C. or more was selected from the various solid plasticizers, and was selected from the bis (polyalkylcyclohexyl phthalate). )
Due to the melting point drop phenomenon, the melting point of the mixed solid plasticizer is lower than the melting point of these plasticizers alone, and it has been found that sufficient tackiness is developed during heating.
When these solid plasticizers are used for the heat-sensitive adhesive composition,
The temperature at which plasticization of the thermoplastic resin starts to occur can be increased, that is, the blocking resistance is improved, and further, the recrystallization of the solid plasticizer once melted can be prevented or delayed, and as a result, the label can be obtained. At the temperature at which sticking or the like is performed, that is, at the time of heating, it is found that not only sufficient tackiness is developed, but also after development, high adhesiveness and transparency can be maintained for a long period of time, leading to the completion of the present invention. It is a thing.

That is, according to the first aspect of the present invention,
In a heat-sensitive adhesive composition containing a thermoplastic resin (A) and a solid plasticizer (B), as the solid plasticizer (B),
There is provided a heat-sensitive adhesive composition characterized by using a combination of bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C. and a compound (B2) having a melting point of 100 ° C. or more.

According to the second aspect of the present invention, the first aspect is provided.
Compound (B2) having a melting point of 100 ° C. or higher
Is selected from the group consisting of phosphate compound (a), phthalate compound (b), hindered phenol compound (c), triazole compound (d), and hydroquinone compound (e) A heat-sensitive adhesive composition, characterized in that the composition is at least one compound.

Further, according to the third aspect of the present invention, the first aspect
Alternatively, in the second invention, bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C.
Is a bis (3,3,5-trimethylcyclohexyl) phthalate.

According to the fourth aspect of the present invention, the first aspect is provided.
In any one of the inventions of (1) to (3), the content of the solid plasticizer (B) is 30 per 100 parts by weight of the thermoplastic resin (A).
To 1000 parts by weight.

According to a fifth aspect of the present invention, there is provided a heat-sensitive adhesive composition according to any one of the first to fourth aspects, further comprising a tackifier (C). .

Further, according to the sixth aspect of the present invention, the first aspect is provided.
In any one of the above inventions, the thermoplastic resin (A)
Is a water-based composition dispersed in water.

On the other hand, according to the seventh aspect of the present invention, the first
The present invention provides a heat-sensitive adhesive characterized by using the heat-sensitive adhesive composition according to any one of the first to sixth aspects.

According to an eighth aspect of the present invention, there is provided a heat-sensitive adhesive laminate in which at least one surface of a substrate is coated with the heat-sensitive adhesive according to the seventh invention. You.

Further, according to a ninth aspect of the present invention, there is provided the heat-sensitive adhesive laminate according to the eighth aspect, wherein the shape of the heat-sensitive adhesive laminate is a tape or a sheet. Is done.

Further, according to a tenth aspect of the present invention, at least one surface of the substrate is coated with the heat-sensitive adhesive according to the seventh aspect to form an adhesive layer. A method for producing a heat-sensitive adhesive laminate is provided.

As described above, the present invention has a melting point of 100 ° C.
Bis (polyalkylcyclohexyl) phthalate (B1) and a compound having a melting point of 100 ° C. or more (B2)
The present invention relates to a heat-sensitive adhesive composition, a heat-sensitive adhesive laminate, and the like, which are characterized by using the following in combination. Preferred embodiments thereof include the following. (1) In the first or second invention, the melting point of the mixed solid plasticizer comprising at least two kinds of compounds is 60 to 100.
C. A heat-sensitive adhesive composition, (2) The heat-sensitive adhesive composition according to the above (1), wherein the mixed solid plasticizer has a melting point of 70 to 90 ° C. (3) The heat-sensitive adhesive composition according to the above (1), wherein the thermoplastic resin (A) is an acrylic polymer in the first or second invention.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the heat-sensitive adhesive composition, the heat-sensitive adhesive, the heat-sensitive adhesive laminate using the same and the method for producing the same according to the present invention will be described in detail.

1. Thermoplastic resin (A) The thermoplastic resin (A) that can be used in the heat-sensitive adhesive composition of the present invention is not particularly limited as long as it can plasticize and exhibit adhesiveness. ,
(Meth) acrylic acid ester homo- or copolymer, styrene- (meth) acrylic acid ester copolymer, vinyl acetate- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid ester copolymer, Ethylene-
(Meth) acrylic acid copolymer, (meth) acrylic acid ester- (meth) acrylic acid copolymer, styrene-acrylonitrile- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid ester- (meth) ) Acrylic acid copolymer, styrene-acrylonitrile- (meth)
Acrylic ester- (meth) acrylic acid copolymer, ethylene-vinyl acetate- (meth) acrylic acid ester copolymer, vinylpyrrolidone- (meth) acrylic acid ester copolymer, styrene-butadiene- (meth) acrylic acid Acrylic polymer containing (meth) acrylic acid or an ester thereof as a monomer, such as a copolymer; vinyl acetate resin containing vinyl acetate as a monomer, such as a vinyl acetate resin or an ethylene-vinyl acetate copolymer Styrene-butadiene copolymer, isobutylene resin, isobutylene-
Synthetic rubber such as isoprene copolymer, butadiene resin, styrene-isoprene copolymer, acrylonitrile-butadiene copolymer; natural rubber;
Examples thereof include a vinyl chloride copolymer, a vinyl chloride-vinylidene chloride copolymer, a vinyl virolidone-styrene copolymer, a chlorinated propylene resin, a urethane resin, and ethyl cellulose. These thermoplastic resins may be used alone or in combination of two or more.

Preferred thermoplastic resins include acrylic polymers (for example, acrylic copolymers containing (meth) acrylic acid ester as a monomer), vinyl acetate polymers,
Synthetic rubber, natural rubber and the like can be mentioned. Among acrylic polymers, particularly, acrylate-methacrylate copolymers (for example, C _2-10 alkyl acrylate-C _1-4 alkyl methacrylate copolymers), acrylate-methacrylic acid Ester- (meth) acrylic acid copolymer (for example, C _2-10 alkyl acrylate-C _1-4 alkyl methacrylate- (meth) acrylic acid copolymer), acrylate-styrene- (meth) Acrylic acid copolymer (for example, acrylic acid C _2-10 alkyl ester-
An acrylic acid ester such as styrene- (meth) acrylic acid copolymer) (for example, _C2-10 alkyl acrylate) and a methacrylic acid ester (for example, _C1-4 alkyl methacrylate) or styrene as a comonomer Acrylic copolymers are preferred.

Glass transition temperature (Tg) of thermoplastic resin
Can be appropriately selected in consideration of the type of the adherend and the like, as long as the adhesiveness and the blocking resistance in the case of a heat-sensitive adhesive tape or a heat-sensitive adhesive sheet are not impaired.
The temperature is about 70C, preferably about 0C to 30C. When the glass transition temperature is lower than −10 ° C., the blocking resistance tends to decrease. On the other hand, if the glass transition temperature is too high, the adhesiveness tends to decrease.

2. Solid Plasticizer (B) The solid plasticizer (B) used in the present invention has a melting point of 100%.
It is a blend of bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of lower than 100 ° C and a compound (B2) having a melting point of 100 ° C or higher.

2.1 Bis (polyalkylcyclohexyl) phthalate (B1) The bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C. used in the present invention is 3,3,5-trimethyl Cyclohexanol, 2,
3,5-trimethylcyclohexanol, 3,5 dimethylcyclohexanol, 2,3,4-trimethylcyclohexanol, 3,3,5,5-tetramethylcyclohexanol, 3,5-di-t-butylcyclohexanol, Bis (3,3,5-trimethylcyclohexyl) phthalate, bis (3,3,5) obtained by the reaction of a polyalkylcyclohexanol such as 3-methyl or 6-isopropylcyclohexanol with phthalic anhydride or the like.
-Trimethylcyclohexyl) phthalate, bis (2,
3,5-trimethylcyclohexyl) phthalate, bis (3,5-dimethylcyclohexyl) phthalate, bis (2,3,4-trimethylcyclohexyl) phthalate, bis (3,3,5,5-tetramethylcyclohexyl) phthalate, bis Compounds such as (3,5-di-t-butylcyclohexyl) phthalate and bis (3-methyl, 6-isopropylcyclohexyl) phthalate are exemplified, and bis (3,3,5-trimethylcyclohexyl) phthalate (melting point: 93 ° C.) Is particularly preferred.

2.2 Compound (B) having a melting point of 100 ° C. or higher
2) The compound (B2) having a melting point of 100 ° C. or more used in the present invention includes a phosphate compound (a), a phthalate compound (b), a hindered phenol compound (c), and a triazole compound (D) and at least one compound selected from the group consisting of hydroquinone-based compounds (e).

(1) Phosphate ester compound (a) In the present invention, as one of the specific solid plasticizers (B2), the following general formula (1) or (2) having a melting point of 100 ° C. or more: The phosphoric ester compound (a) represented by When trivalent phosphite compound is mixed with other compounds and heat-sensitive, it is not only melted but also converted to oxides and becomes an unsuitable substance. Not used in the invention.

[0030]

Embedded image

(Wherein, R ^{1 to} R ⁷ each represent a hydrocarbon group or a heterocyclic group, A represents a divalent hydrocarbon group or a heterocyclic group, and m represents 0 to 3 Indicates an integer, provided that
R ¹ , R ² and A (when m = 1 to 3), R ³ , R ⁴ and A
(When m = 1 to 3), R ¹ , R ³ and R ⁴ (when m = 0), R ⁵ , R ⁶ and R ⁷ each have at least two groups bonded to each other to contain a phosphorus atom (May form a ring)

Specific examples of the above-mentioned phosphate compound (a) include compounds represented by the following structural formula (3) (phenylpentaerythritol phosphate) (melting point: 103 ° C.), 3,5 -Di-t-butyl-4
-Hydroxy-benzylphosphonate-diethyl ester (melting point: 120 ° C.) (corresponding to a hindered phenol compound).

[0033]

Embedded image

(2) Phthalate Ester Compound (b) In the present invention, a phthalate ester compound (b) having a melting point of 100 ° C. or more is used as one of the specific solid plasticizers (B2). . As the phthalic acid esters, dicyclohexyl phthalate (melting point: 61 ° C.) or the like has been conventionally used as a solid plasticizer for delayed tack, but in the present invention, as described above, one having a melting point of 100 ° C. or more is used. .

Specific examples of such phthalic ester compounds include dimenthol phthalate (melting point 134 ° C.) and dibornyl phthalate (melting point 136).
C), bis (cis-3,3,5-trimethylcyclohexyl) terephthalate (melting point 133 ° C), di-2-phenoxyethyl terephthalate (melting point 114 ° C), and dimethyl terephthalate (melting point 141 ° C).

(3) Hindered phenolic compound (c) Next, in the present invention, the hindered phenolic compound (c) having a melting point of 100 ° C. or more is also a solid plasticizer (B
Used as one of 2). Specific examples of the hindered phenol compound include, for example, N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamide) (melting point: 156 ° C.),
4′-butylidenebis (3-methyl-6-t-butylphenol) (melting point 208 ° C.), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (melting point 185 ° C.) , Tetrakis [methylene-
3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate] methane (melting point 110 ° C.),
1,6-hexanediol-bis [3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate] (melting point: 106 ° C), 3,5-di-t-butyl-4-
Hydroxy-benzylphosphonate-diethyl ester (melting point 120 ° C.), 4,4′-thiobis (2-methyl-6-t-butylphenol) (melting point 127 ° C.),
4,4′-thiobis (3-methyl-6-t-butylphenol) (melting point 128 ° C.), 2,2′-methylenebis (4-methyl-6-t-butylphenol) (melting point 13
0 ° C.), 2,2′-methylenebis (4-ethyl-6-t
-Butylphenol) (melting point 130 ° C.), 2,4,6-
Tri-t-butylphenol (melting point 131 ° C.), and 4
-Hydroxy-methyl-2,6-di-t-butylphenol (melting point 140 ° C).

(4) Triazole Compound (d) In the present invention, a triazole compound (d) having a melting point of 100 ° C. or more can be used as one of the specific solid plasticizers (B2). Specific examples of such a triazole compound (d) include, for example, 2-
(2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole (mp 154 ° C.), 2-
(2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole (mp 156
° C), 2,2'-methylenebis [4- (1,1,3,3
-Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] (melting point 195 ° C), 2-
(2′-hydroxy-5-t-octylphenyl) benzotriazole (melting point 104 ° C.), 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl)
Phenyl] benzotriazole (melting point 139 ° C.) and 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole (melting point 140 ° C.).

(5) Hydroquinone Compound (e) In the present invention, a hydroquinone compound (d) having a melting point of 100 ° C. or more can be used as one of the specific solid plasticizers (B2). Specific examples of such a hydroquinone-based compound (d) include, for example,
Hydroquinone diacetate (melting point 123 ° C.), trimethylhydroquinone diacetate (melting point 109 ° C.), 3,4,5-trimethylcatechol diacetate (melting point 120 ° C.), and the like.

2.3 Combined Use Ratio of Mixed Solid Plasticizer In the present invention, bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C. and compound (B2) having a melting point of 100 ° C. or more are used. The combination ratio is set at a temperature at which the heat-sensitive adhesive composition to be used is at a practical temperature, for example, 12 ° C.
The mixed solid plasticizer has a melting point of, for example, 70 to 1 so that the mixed solid plasticizer can be thermally activated at 0 ° C. or less and exhibit adhesiveness.
00C, preferably 70-90C,
Selected.

2.4 Mixing Ratio of Thermoplastic Resin (A) and Solid Plasticizer (B) In the present invention, the total content of the solid plasticizer (B) (however, as a solid content) is determined by the thermoplastic resin (B). A) For example, 30 to 1000 parts by weight, preferably 10 parts by weight, per 100 parts by weight.
0 to 1000 parts by weight, more preferably 150 to 900 parts by weight
Parts by weight, especially about 200 to 800 parts by weight. If the content of the solid plasticizer is less than 30 parts by weight, sufficient tackiness may not be exhibited at the time of heating, and if the content is more than 1000 parts by weight, cohesive strength may be reduced and sufficient adhesive strength may not be exhibited. There is.

As a result of examining the mechanism of developing delayed tack adhesiveness typified by the delayed tack label of the present inventors, the heat-sensitive adhesive composition of the present invention uses the above-mentioned solid plasticizer (B1 ) And the solid plasticizer (B2) are used in combination, so that the temperature at which adhesiveness is exhibited is high, and at the label sticking temperature, the solid plasticizer not only melts and is easily plasticized, but also recrystallizes the solid plasticizer. Is delayed, and the adhesiveness is maintained for a long time.

3. Tackifier (C) The heat-sensitive adhesive composition of the present invention comprises a thermoplastic resin (A) as a binder resin and a solid plasticizer (B) as main components, and the solid plasticizer (B) Is a combination of the solid plasticizer (B1) and the solid plasticizer (B2), and further contains a tackifier (C) if necessary. As described above, a solid plasticizer and, if necessary, a tackifier are dispersed in a thermoplastic resin as a binder resin, and the solid plasticizer is melted by heating, thereby plasticizing the binder resin and forming an adhesive. Can be expressed.

Examples of tackifiers that can be used include terpene resins, aliphatic petroleum resins, aromatic petroleum resins, cumarone-indene resins, styrene resins, phenol resins, terpene-phenol resins, and rosin derivatives. (Rosin, polymerized rosin, hydrogenated rosin and their esters with glycerin, pentaerythritol, etc.
Resins such as resin acid dimer) and xylene resin. Two or more of these tackifiers may be used in combination.

The content of the tackifier (C) is not particularly limited, but can be appropriately selected according to the combination of the thermoplastic resin (A) and the solid plasticizer (B). It is about 10-600 parts by weight, preferably about 20-500 parts by weight, based on 100 parts by weight of the resin (A).

4. Other Additives The heat-sensitive adhesive composition of the present invention may further contain, in addition to the tackifier (C), conventional additives as long as the properties are not impaired.
For example, antifoaming agents, coating improvers, thickeners, lubricants, stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), antistatic agents, antiblocking agents (inorganic particles, organic particles, etc.), etc. May be added.

5. Heat-Sensitive Adhesive (Heat-Sensitive Pressure-Sensitive Adhesive Layer) The heat-sensitive adhesive composition of the present invention is obtained by forming (coating and laminating) a heat-sensitive adhesive layer on at least one surface of a substrate. A heat-sensitive adhesive tape or an adhesive sheet, which is an adhesive laminate, is obtained. That is, the heat-sensitive adhesive layer contains the thermoplastic resin (A), the solid plasticizer (B), and, if desired, the tackifier (C) and other additives. An object can be formed by coating (coating) on a substrate. For example, an aqueous composition in which a thermoplastic resin is dispersed in water is applied, or a heat-sensitive adhesive composition is dissolved in an organic solvent and applied, or a heat-sensitive adhesive composition is heated and melted. The heat-sensitive pressure-sensitive adhesive layer can be formed by performing the coating. Among these, a method of applying an aqueous composition in which a thermoplastic resin is dispersed in water is preferred.

The dispersant that can be used for dispersing the heat-sensitive adhesive composition is not particularly limited,
Any of conventionally known anionic (anionic) and nonionic (nonionic) dispersants can be used.
Examples of the anionic dispersant include a carboxylate, a sulfate, a sulfonate, and a phosphate, and among them, ammonium carboxylate is preferable. Examples of the nonionic dispersant include polyethylene glycol-type dispersants and polyhydric alcohol-type dispersants.

As the method for preparing the aqueous composition, various conventionally known methods can be employed. For example, as a preparation method, a method in which the components constituting the heat-sensitive adhesive composition of the present invention are previously mixed and then dispersed in water, a thermoplastic resin emulsion or a tackifier emulsion, a solid plasticizer aqueous dispersion or a combination thereof A method of mixing these emulsions after dispersing a solid plasticizer to be dispersed, a solid plasticizer aqueous dispersion or a solid plasticizer to be used in combination is dispersed in water, and a thermoplastic resin emulsion and a tackifier emulsion are added to the dispersion. And the like. As a method of dispersing a solid plasticizer in an emulsion or water, a method using an aqueous dispersion of a solid plasticizer, a method of dispersing a molten solid plasticizer, a method of dispersing a solid plasticizer into fine powder,
And a method of dispersing a solid plasticizer in the form of fine powder.

The thermoplastic resin emulsion may be prepared by emulsion polymerization. Alternatively, a polymer may be prepared by a method other than emulsion polymerization and then emulsified by using additives as necessary. You may. For example,
An additive (eg, emulsifier, pH adjuster, acid, etc.) is added to an organic solution containing a polymer polymerized in the presence of a water-soluble organic solvent (eg, alcohol such as isopropyl alcohol), and then water is added. Then, by emulsifying, and then removing the organic solvent, a thermoplastic resin emulsion can be prepared.

The average particle size of the solid plasticizer in the aqueous composition is preferably about 0.5 to 20 μm, more preferably about 1 to 15 μm. Average particle size 0.5
If the particle size is smaller than μm, the blocking resistance may decrease, or the pulverization may require time to lower the productivity. If the average particle size exceeds 20 μm, the coated surface may be rough and the quality of the label may be reduced.

As a method of applying (coating) the heat-sensitive adhesive composition, for example, a method using a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater, a comma coater, a gravure coater, a silk screen coater, or the like. Can be mentioned. The heat-sensitive adhesive layer can also be formed by printing using a gravure printing machine or the like. The thickness of the heat-sensitive adhesive layer is, for example, 4 to 20 μm, and preferably 5 to 15 μm.

6. Substrate The substrate in the present invention is not particularly limited, paper, coated paper,
A plastic sheet or film, glass, etc. can be mentioned, and a transparent plastic sheet or film is preferable. Examples of the polymer constituting the plastic sheet or film include polyolefin such as polyethylene and polypropylene, ethylene-vinyl acetate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, poly (meth) acrylate, and polystyrene. , Polyvinyl alcohol, ethylene-vinyl alcohol copolymer, cellulose derivatives such as cellulose acetate, polyesters (polyalkylene terephthalate such as polyethylene terephthalate and polybutylene terephthalate,
Polyalkylene naphthalate such as polyethylene naphthalate, polybutylene naphthalate, etc.), polycarbonate, polyamide (polyamide 6, polyamide 6/6, polyamide 6/10, polyamide 6/12, etc.), polyester amide, polyether, polyimide, polyamide Examples thereof include imides and polyether esters, and copolymers, blends and cross-linked products thereof may also be used. The substrate may be a single layer or multiple layers.

7. Heat-sensitive adhesive laminate In the present invention, a heat-sensitive adhesive laminate in which a heat-sensitive adhesive layer is formed (coated, laminated) on at least one surface of a substrate is a heat-sensitive adhesive tape or a heat-sensitive adhesive sheet. Used as such. The heat-sensitive adhesive laminate of the present invention comprises the solid plasticizer (B1) and the solid plasticizer (B) as solid plasticizers.
The combined use of 2) causes a decrease in the melting point of the mixed solid plasticizer, and the heat-sensitive adhesive composition can be heat-activated at a practical temperature, for example, 120 ° C. or lower, and can exhibit adhesiveness. After the property is developed, the solid plasticizer does not recrystallize or the recrystallization is delayed, and as a result, there is an effect that the tackiness is maintained as when the tackiness is developed. Therefore, the heat-sensitive adhesive laminate is not limited to only the above-described heat-sensitive adhesive tape or heat-sensitive adhesive sheet, and even after being attached to an adherend,
Since the adhesiveness can be maintained for a long time, it can be used for applications such as adhesive tapes, labels, protective films, and fans.

[0054]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, the average particle size of the solid plasticizer was measured by a laser diffraction type particle size distribution analyzer (LA-500, manufactured by Horiba, Ltd.).
The median diameter is described.

[Preparation Example 1] (Preparation of aqueous dispersion of solid plasticizer 1) Bis (3,3,5-trimethylcyclohexyl) phthalate (melting point 93 ° C) was used as a solid plasticizer (B) in a container equipped with a disperser stirrer. 100 parts by weight, 3.5 parts by weight of a sulfonate-type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill, and the average particle diameter is 2 parts. .2 μm (measured by HORIBA, LA-500 / the same applies hereinafter) to obtain an aqueous dispersion of bis (3,3,5-trimethylcyclohexyl) phthalate 1 (solid plasticizer aqueous dispersion 1). ) Got. This aqueous dispersion 1 was subjected to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 15 rotations).
Min) was 0.04% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 2] (Preparation of aqueous dispersion of solid plasticizer 2) Di-2-phenoxyethyl phthalate (melting point: 114 ° C) as a solid plasticizer (B) was placed in a container equipped with a disperser stirrer.
100 parts by weight, 3.5 parts by weight of a sulfonate-type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill, and the average particle diameter is 2 parts. By pulverizing and dispersing to a thickness of 0.5 μm, an aqueous dispersion of di-2-phenoxyethyl phthalate (solid plasticizer aqueous dispersion 2) was obtained. This aqueous dispersion 2 was subjected to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations,
15 minutes) was 0.02% (based on the aqueous dispersion). Also, without sinking for three months,
The storage stability was also good (evaluation of storage stability ◎).

[Preparation Example 3] (Preparation of aqueous dispersion of solid plasticizer 3) In a vessel equipped with a disper stirrer, 100 parts by weight of dimenthol phthalate (melting point 134 ° C) as a solid plasticizer (B) and sulfonic acid as a dispersant 3.5 parts by weight of the salt-type anionic surfactant and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill, and pulverized and dispersed until the average particle diameter becomes 2.6 μm. Thus, an aqueous dispersion of dimenthol phthalate (aqueous dispersion of solid plasticizer 3) was obtained. This aqueous dispersion 3 had an agglomerate generation rate of 0.1% (based on the aqueous dispersion) in a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 15 minutes).
In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 4] (Preparation of solid plasticizer aqueous dispersion 4) In a container equipped with a disper stirrer, bis (3,3,5-trimethylcyclohexyl) terephthalate (melting point 133 ° C) was used as the solid plasticizer (B). 100 parts by weight, 3.5 parts by weight of a sulfonate-type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill, and the average particle diameter is 2 parts. The aqueous dispersion 4 of bis (3,3,5-trimethylcyclohexyl) terephthalate was obtained by pulverizing and dispersing to a thickness of 0.8 μm.
(Solid plasticizer aqueous dispersion 4) was obtained. This aqueous dispersion 4 is
According to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 15 minutes), the rate of occurrence of aggregates was 0.06% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 5] (Preparation of aqueous dispersion of solid plasticizer 5) In a container equipped with a disper stirrer, 3,5-di-t-butyl-4-hydroxy-benzylphosphate was used as a solid plasticizer (B). -Diethyl ester (melting point 120 ° C) 1
00 parts by weight, 4.5 parts by weight of a polyoxyethylene sulfate ester type anionic surfactant as a dispersant, and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill, and the average particles are dispersed. By pulverizing and dispersing until the diameter becomes 2.1 μm, 3,5-di-t-butyl-4
An aqueous dispersion 5 of -hydroxy-benzyl phosphate-diethyl ester (solid plasticizer aqueous dispersion 5) was obtained. This aqueous dispersion 5 was subjected to a Marlon mechanical stability test (conditions: 25
(kg, 1000 rotations, 15 minutes), the occurrence of aggregates was 0.3% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 6] (Preparation of solid plasticizer aqueous dispersion 6) 1,1,3-Tris (2-methyl-4-hydroxy-) was added as a solid plasticizer (B) to a container equipped with a disperser stirrer.
5-tert-butylphenyl) butane (melting point 185 ° C) 10
0 parts by weight, 4.5 parts by weight of a polycarboxylic acid type anionic surfactant as a dispersant, and 90 parts by weight of ion-exchanged water are mixed and stirred, and then the liquid is sent to a bead mill to have an average particle diameter of 2 parts. The aqueous dispersion 6 of 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (solid plasticizer aqueous dispersion 6) was obtained by pulverizing and dispersing until the thickness became 0.9 μm. I got This aqueous dispersion 6 was subjected to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 1 rotation).
5 minutes) was 0.7% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 7] (Preparation of aqueous dispersion of solid plasticizer 7) As a solid plasticizer (B), tetrakis [methylene-3- (3 ', 5'-di-t-) was placed in a container equipped with a disperser stirrer.
[Butyl-4-hydroxyphenyl) propionate] 100 parts by weight of methane (melting point: 110 ° C.), 4.5 parts by weight of a polycarboxylic acid type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water were mixed and stirred, Next, the liquid is sent to a bead mill until the average particle diameter becomes 2.9 μm.
By pulverizing and dispersing, tetrakis [methylene-3
-(3 ', 5'-Di-t-butyl-4-hydroxyphenyl) propionate] methane aqueous dispersion 7 (solid plasticizer aqueous dispersion 7) was obtained. This aqueous dispersion 7 was subjected to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations, 15 rotations).
Min) was 0.6% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 8] (Preparation of aqueous dispersion of solid plasticizer 8) Resorcinol bis [di (2,6-dimethylphenyl) phosphate] (melting point: 95) as a solid plasticizer (B) in a container equipped with a disperser stirrer. C) 100 parts by weight, 4.5 parts by weight of a polyoxyethylene sulfate ester type anionic surfactant as a dispersant and 90 parts by weight of ion-exchanged water were mixed and stirred, and then the liquid was sent to a bead mill. By pulverizing and dispersing until the average particle diameter became 2.2 μm, an aqueous dispersion 8 of resorcinol bis [di (2,6-dimethylphenyl) phosphate] (solid plasticizer aqueous dispersion 8) was obtained. This aqueous dispersion 8 had an aggregate generation rate of 0.4% (based on the aqueous dispersion) in a Marlon mechanical stability test (condition: 25 kg, 1000 rotations, 15 minutes). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 9] (Preparation of solid plasticizer aqueous dispersion 9) 2- (2'-hydroxy-3'-t-butyl-5 ') as a solid plasticizer (B2) was placed in a container equipped with a disper stirrer.
3.-Methylphenyl) -5-chlorobenzotriazole (melting point 140 ° C.) 100 parts by weight, polyoxyethylene sulfate ester type anionic surfactant as dispersant
5 parts by weight and 90 parts by weight of ion-exchanged water are mixed and stirred,
Next, the liquid was sent to a bead mill, and the average particle diameter was 2.2.
By pulverizing and dispersing to a thickness of 2 μm, 2- (2 ′
-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole aqueous dispersion 9 (solid plasticizer aqueous dispersion 9) was obtained. This aqueous dispersion 9 was subjected to a Marlon mechanical stability test (conditions: 25 kg, 1000 rotations,
15%) was 0.8% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

[Preparation Example 10] (Aqueous dispersion of solid plasticizer 10
Preparation of trimethylhydroquinone diacetate (melting point: 10) as a solid plasticizer (B2) in a container equipped with a disper stirrer.
9 ° C.) 100 parts by weight, 4.5 parts by weight of a polycarboxylic acid type anionic surfactant as a dispersant and 90 parts of ion-exchanged water
Parts by weight, stirred and then sent to a bead mill, and pulverized and dispersed until the average particle size became 2.2 μm, thereby obtaining an aqueous dispersion 10 of trimethylhydroquinone diacetate (solid plasticizer water). A dispersion 10) was obtained. This aqueous dispersion 10 was subjected to a Marlon mechanical stability test (conditions: 25
(kg, 1000 rotations, 15 minutes), the occurrence of aggregates was 0.3% (based on the aqueous dispersion). In addition, storage stability was good without sedimentation for 3 months (evaluation of storage stability ◎).

The solid plasticizer aqueous solutions 1 to 10 prepared above
Table 1 shows the results of the evaluation of the composition of Marlon, the mechanical stability (incidence of aggregates), and the storage stability.

[0066]

[Table 1]

Example 1 (Preparation of Thermosensitive Adhesive Composition 1) The solid plasticizer aqueous dispersions 1 and 2 prepared above were mixed with bis (3,3,5-trimethyl As a thermoplastic resin (A), a styrene-acrylic acid ester copolymer (glass transition temperature Tg) was used as a thermoplastic resin (A) in an aqueous dispersion of a solid plasticizer blended so that cyclohexyl) phthalate: di-2-phenoxyethyl terephthalate = 50: 50. : 20 ° C)
As a tackifier (C), an aqueous dispersion of a polymerized rosin ester resin and water were added, and the mixture was stirred until uniform, to obtain a heat-sensitive adhesive composition 1 having a solid content of 50% by weight. . The mixing ratio at this time was 28 parts by weight of the thermoplastic resin (A) and 14 parts by weight of the tackifier (C) with respect to 100 parts by weight of the solid plasticizer (B).

(Preparation of heat-sensitive adhesive sheet 1)
The heat-sensitive adhesive composition 1 thus prepared is applied to the side of the base paper
Surface) and polyethylene teref with corona discharge treated surface
Tarate film (hereinafter simply referred to as “PET film”)
), The coating amount after drying using a bar coater is 10
g / m ²And dried at 40 ° C for 2 minutes and 30 seconds.
After drying, a heat-sensitive adhesive sheet 1 was obtained.

[Examples 2 to 8, Comparative Examples 1 and 2] The same operation as in Example 1 was carried out using the solid plasticizer aqueous dispersions 1 to 10 prepared as described above in the mixing ratio shown in Table 2. As a result, a heat-sensitive adhesive composition and a heat-sensitive adhesive sheet were obtained.

(1) Performance Evaluation Test (Melting Point of Mixed Plasticizer) A predetermined amount of the aqueous dispersion of the solid plasticizer was blended in a predetermined amount, and the mixture was dried using a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Inc.). , The temperature range is -100 ~
The melting point of the mixed plasticizer was measured under the conditions of 200 ° C. and a heating rate of 20 ° C./min. Table 2 shows the measurement results.

(2) Performance Evaluation Test (Adhesive Strength and Transparency) A heat-sensitive adhesive sheet obtained by coating a PET film was cut into a size of 25 mm in width and 125 mm in length to obtain a test piece. The test piece was heated at 140 ° C. for 30 seconds to develop adhesiveness, and a glass plate [Micr, manufactured by Iwaki Glass Co., Ltd.,
o S1ideG1ass white-green polishing), and affixed by reciprocating once with a rubber roll under a load of 2 kg. This is left in an atmosphere of 23 ° C. and 50% RH,
One day, one month, and three months later, an adhesive strength test was performed.
The adhesive strength test was performed using a tensile tester (Orientec,
Using Tensilon UCT-5T), a pulling speed of 30
The adhesive strength was measured at 0 mm / min and a peel angle of 180 °. Further, the transparency was visually observed. Table 2 shows the results.

(3) Performance Evaluation Test (Blocking Resistance) Four heat-sensitive adhesive sheets obtained by coating on one side art paper were coated with the glossy surface (surface) of the art paper and the heat-sensitive adhesive composition. 5000gf /
After a load of 9 cm ² was left in an atmosphere of 50 ° C. for 24 hours, blocking resistance was evaluated according to the following criteria. Table 2 shows the results. 5: Peeled without resistance during peeling. 4: Peeling was performed with a slight sound when peeling. 3: Peeling was performed while making continuous sound during peeling. 2: Some paper fibers remained in the adhesive layer at the time of peeling. 1: The paper was torn by blocking.

[0073]

[Table 2]

From the results shown in Table 2, in the heat-sensitive adhesive composition containing the thermoplastic resin (A) and the solid plasticizer (B), in Comparative Example 1, the solid plasticizer (B) had a melting point of 1
Bis (3,3,5-trimethylcyclohexyl) phthalate (melting point 93 ° C.) (B1) having a melting point of less than 00 ° C. and a compound (bis (3,3,5-trimethylcyclohexyl) terephthalate having a melting point of 100 ° C. or more (melting point 133 ° C.) ))
(B2) and a solid plasticizer having a melting point of less than 100 ° C. (resorcinol bis [di (2,6-dimethylphenyl) phosphate] (melting point: 95 ° C.)) are also mixed. The melting point was as low as 69 ° C., the adhesive strength was good at first but became zero after 3 months, the transparency was good at first but became opaque after 2 months, and the blocking resistance was very poor. In Comparative Example 2, as the solid plasticizer (B), the solid plasticizer (B
Since only dimenthol phthalate (melting point 134 ° C.) was used as 2), no tackiness was exhibited from the beginning. In contrast, in a heat-sensitive adhesive composition containing a thermoplastic resin (A) and a solid plasticizer (B), bis (polyalkylcyclohexyl) phthalate having a melting point of less than 100 ° C. as the solid plasticizer (B) Examples 1 to 3 in which (B1) and a compound (B2) having a melting point of 100 ° C. or higher were used in combination.
The melting point of the mixed plasticizer of No. 8 is 72 to 85 ° C., which is the melting point of the solid plasticizer exhibiting adhesiveness. As a result, the heat-sensitive adhesive sheets of Examples 1 to 8 using the mixed plasticizer are It was found that the adhesive strength was high and the blocking resistance was excellent.

[0075]

The heat-sensitive adhesive composition of the present invention has, as a solid plasticizer, bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C. and a melting point higher than that of a conventionally used one. Since the compound (B2) having a high temperature (100 ° C. or higher) is used in combination, the temperature at which plasticization of the thermoplastic resin starts to occur can be increased, that is, the blocking resistance can be improved and the solid once melted can be obtained. The recrystallization of the plasticizer can be prevented or delayed, and as a result, the heat-sensitive adhesive sheet or the like obtained using the heat-sensitive adhesive composition can be heated and dried at a higher temperature and stored for a long time. Even when blocking does not occur, high adhesive strength and high transparency can be maintained over a long period of time.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4J004 AA04 AA05 AA07 AA09 AA10 AA14 AB03 CA02 CA04 CA05 CA06 CA07 CB02 DB01 FA01 4J040 CA011 CA031 DA061 DB061 DC031 DE021 DF031 EF001 HB21 HB34 HB35 HC25 LA01 JA03 JA03 JA03 PA23

Claims (10)

[Claims] 1. A thermoplastic resin (A) and a solid plasticizer (B)
A bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C. as the solid plasticizer (B);
A heat-sensitive adhesive composition, which is used in combination with a compound (B2) having a temperature of 00 ° C. or higher. 2. Compound (B2) having a melting point of 100 ° C. or higher
Is selected from the group consisting of phosphate compound (a), phthalate compound (b), hindered phenol compound (c), triazole compound (d), and hydroquinone compound (e) The heat-sensitive adhesive composition according to claim 1, which is at least one compound. 3. A bis (polyalkylcyclohexyl) phthalate (B1) having a melting point of less than 100 ° C.
The heat-sensitive adhesive composition according to claim 1, wherein the composition is 3,5-trimethylcyclohexyl) phthalate. 4. The method according to claim 1, wherein the total content of the solid plasticizer (B) is 30 to 1000 parts by weight based on 100 parts by weight of the thermoplastic resin (A). Item 6. The heat-sensitive adhesive composition according to item 1. 5. The heat-sensitive adhesive composition according to claim 1, further comprising a tackifier (C). 6. The heat-sensitive adhesive composition according to claim 1, wherein the thermoplastic resin (A) is an aqueous composition dispersed in water. 7. A heat-sensitive adhesive, comprising using the heat-sensitive adhesive composition according to claim 1. 8. The method according to claim 7, wherein at least one surface of the substrate is provided.
A heat-sensitive adhesive laminate obtained by coating the heat-sensitive adhesive described in the above. 9. The heat-sensitive adhesive laminate according to claim 8, wherein the shape of the heat-sensitive adhesive laminate is a tape or a sheet. 10. A method for producing a heat-sensitive adhesive laminate, comprising forming a pressure-sensitive adhesive layer by coating the heat-sensitive adhesive according to claim 7 on at least one surface of a substrate.