JPH1025459A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition having an excellent cohesive force and being capable of exhibiting an excellent release from an adherend irrespectively of the kind of the adherend. SOLUTION: This composition comprises a block copolymer (I) having polymer A comprising methyl methacrylate and a tackifying resin. The tackifying resin should have poor compatibility with polymer A, and block copolymer I should be a copolymer comprising polymer A and an alkyl (meth)acrylate B with a 1-12 C alkyl. The haze of a mixture prepared by mixing 100 pts.wt. polymer A with 10 pts.wt. above tackifying resin should be 15% or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive composition which has excellent cohesion and can exhibit excellent peel resistance regardless of the type of adherend.

[0002]

2. Description of the Related Art Acrylic pressure-sensitive adhesive compositions have excellent weather resistance and are therefore used in many applications such as pressure-sensitive adhesive layers of pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets. Above all, the pressure-sensitive adhesive composition using an acrylic block copolymer is excellent in tackiness in a wide temperature range from low to high temperatures and exhibits high cohesive strength, and thus provides a pressure-sensitive adhesive excellent in pressure-sensitive adhesive property balance. be able to.

[0003] However, the pressure-sensitive adhesive composition comprising only an acrylic block copolymer has insufficient peeling resistance depending on the type of adherend. For this reason, in order to exhibit excellent peeling resistance regardless of the type of the adherend, a tackifier resin is blended. For example, JP-A-2-103277 discloses a pressure-sensitive adhesive composition containing various tackifier resins.

However, when a tackifier resin is added to the pressure-sensitive adhesive composition, the peeling resistance is remarkably improved, but the cohesive strength is reduced. For this reason, the feature of the pressure-sensitive adhesive composition comprising an acrylic block copolymer, which is excellent in the balance of pressure-sensitive adhesive properties, is lost.

[0005]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a pressure-sensitive adhesive composition which has excellent cohesion and can exhibit excellent peel resistance regardless of the type of adherend. Aim.

[0006]

The present invention relates to a block copolymer (I) having a polymer comprising methyl methacrylate and a pressure-sensitive adhesive composition comprising a tackifier resin. I) is a block copolymer represented by the general formula (AB) a-A, a block copolymer represented by the general formula (BA) b-B, and a block copolymer represented by the general formula (AB) ) A group (1) of block copolymers having a linear structure constituted by the block copolymers represented by c, and a block copolymer represented by the general formula (AB) dX And a group (2) of block copolymers having a comb-like structure or a star-like structure composed of a block copolymer represented by the general formula Ae-T-Bf. The two groups of group (1) and group (2) of the above block copolymer are combined. At least one block copolymer selected from the group consisting of the above, and the tackifier resin is a pressure-sensitive adhesive composition having poor compatibility with the polymer comprising methyl methacrylate.

In the formula, A represents a polymer composed of methyl methacrylate. B has 1 to 12 carbon atoms in the alkyl group.
Or a copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group. a, b, and c are the same or different and represent an integer of 1 to 10. d represents an integer of 3 to 7. e and f are the same or different and represent an integer of 1 or more, and satisfy the relationship of e + f = 3 to 7. X represents a polyfunctional compound capable of binding d polymers ((AB) d). T represents a polyfunctional compound capable of binding the polymer represented by A and the polymer represented by B. Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive composition of the present invention comprises a block copolymer (I) having a polymer composed of methyl methacrylate, and a tackifier resin. The block copolymer (I) is a block copolymer represented by a general formula (AB) aA, a block copolymer represented by a general formula (BA) bB, A group (1) of a block copolymer having a linear structure constituted by the block copolymer represented by the general formula (AB) c, and a group represented by the general formula (A-B):
B) A block copolymer represented by dX and a block copolymer having a comb-shaped structure or a star-shaped structure composed of a block copolymer represented by a general formula Ae-T-Bf At least one block copolymer selected from the group consisting of the group (2), the group (1) of the block copolymer and the group (2) of the block copolymer. is there.

The block copolymer represented by the general formula (AB) aA, the block copolymer represented by the general formula (BA) b-B, and the block copolymer represented by the general formula (A) -B) The block copolymer represented by c has a linear structure, and the block represented by A has a polymer composed of methyl methacrylate. The polymer composed of methyl methacrylate contains methyl methacrylate as a main component, but may contain an acrylate or the like as long as the adhesive performance such as cohesive strength is not impaired.

The block copolymer represented by the general formula (AB) aA, the block copolymer represented by the general formula (BA) b-B, and the block copolymer represented by the general formula (A) -B) The block copolymer represented by c is an alkyl (meth) having 1 to 12 carbon atoms in the alkyl group as a block represented by B.
It has a polymer composed of an acrylate or a copolymer composed of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms.

An alkyl group constituting a polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group and a copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group The alkyl (meth) acrylate having 1 to 12 carbon atoms is not particularly limited. For example, ethyl (meth) acrylate, n
-Butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, i
-Nonyl (meth) acrylate and the like. By using these alone, a polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group can be obtained, and by using two or more kinds,
A copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group can be used.

The Tg of the polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group and the copolymer comprising the alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group is 0. C. or less is preferred.

In the polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms of the alkyl group or the copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms of the alkyl group, In order to further improve the balance between tackiness and adhesion, a polar monomer can be copolymerized with an alkyl (meth) acrylate having 1 to 12 carbon atoms in the group, if necessary. The polar monomer is not particularly limited, and includes, for example, (meth) acrylic acid, maleic anhydride, itaconic acid, acrylamide, β-hydroxyethyl (meth) acrylate, and the like. These can be used alone or in combination of two or more.

The block copolymer represented by the general formula (AB) aA, the block copolymer represented by the general formula (BA) b-B, and the block copolymer represented by the general formula (A) -B) In any of the block copolymers represented by c, the content of the polymer comprising methyl methacrylate is 3 to 5;
0% by weight is preferred. When the amount is less than 3% by weight, the cohesive force is remarkably reduced, so that the adhesive properties required as an adhesive cannot be exhibited. When the amount exceeds 50% by weight, it becomes difficult to exhibit the adhesiveness. More preferably, it is 5 to 40% by weight.

In the present invention, the above-mentioned general formula (AB)
a-A, a block copolymer represented by the general formula (B-
A) Both the block copolymer represented by b-B and the block copolymer represented by the general formula (AB) c are represented by the block represented by A and the B Blocks are substantially different from each other.

The block copolymer represented by the general formula (AB) aA, the block copolymer represented by the general formula (BA) bB, and the block copolymer represented by the general formula (A) -B) In the block copolymer represented by c, a, b, and c are the same or different and are integers of 1 to 10. If it exceeds 10, the viscosity increases and the coatability to the substrate deteriorates, so that it is limited to the above range. Preferably, it is 1-8.

In the present invention, the above-mentioned general formula (AB)
The block copolymer represented by dX and the block copolymer represented by the general formula Ae-T-Bf have a comb-shaped structure or a star-shaped structure.

In the formula, d represents an integer of 3 to 7. X is
Represents a polyfunctional compound capable of binding d polymers ((AB) d). e and f represent one or more integers satisfying a relationship of e + f = 3 to 7. T is a polymer (A,
Represents a polyfunctional compound capable of binding B).

The polyfunctional compound represented by X or T is not particularly restricted but includes, for example, trimethylolpropane trithioglycolate, trimethylolpropane trithiopropionate, pentaerythritol tetrakisthioglycolate, pentaerythritol Polyvalent mercaptans such as tetrakisthiopropionate, dipentaerythritol hexakisthioglycolate, and dipentaerythritol hexakisthiopropionate; and polyfunctional coupling agents such as tin tetrachloride and silicon tetrachloride.

In the present invention, the weight average molecular weight of the block copolymer (I) is preferably 10,000 to 2,000,000. If it is less than 10,000, it is difficult to balance the cohesive force and the tackiness, and if it exceeds 2,000,000, the viscosity becomes high, and the productivity in the coating process deteriorates. More preferably, it is 30,000 to 1.5 million, and still more preferably, 50,000 to 1
200,000.

The method for synthesizing the block copolymer (I) is not particularly limited, and examples thereof include a living polymerization method, a method using an initiator having a starting point having a different reactivity, and an ultraviolet polymerization method. it can.

According to the above living polymerization method, first, for example, the methyl methacrylate or the alkyl group has 1 to 12 carbon atoms using a living polymerizable initiator.
When the polymerization of either one of the alkyl (meth) acrylates is completed and the polymerization of the block represented by A or the block represented by B is completed, the monomer constituting another polymer or copolymer Is added, and a polymerization reaction is further carried out continuously on the terminal of the growing chain, so that the block represented by B or the block represented by A can be polymerized.

The living polymerization method is not particularly restricted but includes, for example, N, N, N ', N'-tetraethyllithium disulfide, benzyl-N, N-diethyldithiocarbamate, p-xylenebis (N, N-diethyl A method using an iniferter such as dithiocarbamate) as an initiator; a method using an organic lanthanoid compound as an initiator; an anionic polymerization method using an alkyl lithium or the like as an initiator; a group transfer method using a silyl ketene acetal or the like as an initiator; Known methods such as a living anion method and a living radical method can be employed.

The method using an initiator having the above-mentioned starting point having different reactivity is not particularly limited. For example, a method using an initiator having at least two peroxide groups having different radical generation temperatures, a method using a different radical generation mechanism, or the like. A method using an initiator having at least two peroxide groups can be employed.

The method using an initiator having at least two peroxide groups having different radical generation temperatures is as follows.
From the low temperature starting point, the methyl methacrylate, or
Alkyl (meth) having 1 to 12 carbon atoms in the alkyl group
Initiate the polymerization of either one of the acrylates,
By starting the polymerization of the block represented by or the block represented by B, by starting the polymerization of the monomer constituting another polymer or copolymer from the starting point on the high temperature side, The polymerization of the block represented by the above or the block represented by the above A can be carried out.

According to the above-mentioned method using an initiator having at least two peroxide groups having different radical generation mechanisms, for example, a radical is generated using a reducing agent at one starting point, and the above methyl methacrylate or After initiating the polymerization of any one of the alkyl (meth) acrylates having 1 to 12 carbon atoms in the alkyl group and initiating the polymerization of the block represented by A or the block represented by B, From the other starting point to initiate the polymerization of the monomers constituting the other polymer or copolymer, thereby allowing the block represented by B or the block represented by A to be polymerized. .

Specifically, for example, first, an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group and a radical polymerization initiator having two or more peroxide groups in one molecule are set. A polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group or a copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group. The polymer is polymerized, and then the above-mentioned methyl methacrylate is added, and the mixture is heated and reacted at a temperature level 2 which is higher than the above-mentioned temperature level 1, whereby the block copolymer represented by the general formula (AB) c is obtained. Coalescence can be synthesized.

According to the ultraviolet polymerization method, for example, first, an alkyl (meth) acrylate having 1 to 12 carbon atoms of the alkyl group and N, N-diethyldithiocarbamate are mixed, and the inside of the reaction vessel is purged with nitrogen. Then, UV irradiation with an ultraviolet (UV) lamp is performed to irradiate a polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group or an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group. ) A copolymer comprising acrylate is polymerized, and then the above methyl methacrylate is added.
The block copolymer represented by the general formula (AB) aA can be synthesized by polymerizing the polymer composed of methyl methacrylate by irradiation with V.

The block represented by the general formula (AB) dX
The lock copolymer is, for example, AB ^-Naru Living Bro
Cup copolymer with polyfunctional coupling agent
It can be synthesized by ringing.

The block copolymer represented by the above general formula Ae-T-Bf includes, for example, the above methyl methacrylate,
Alternatively, in the presence of a polyvalent mercaptan, any one of the alkyl (meth) acrylates having 1 to 12 carbon atoms in the alkyl group is used to initiate radical polymerization starting from a mercapto group, and the block represented by A or After the polymerization of the block represented by B is started, in the presence of a product by radical polymerization, radical polymerization of a monomer constituting another polymer or copolymer is started, and represented by the above B. Or the block represented by the above A can be synthesized.

As another method, for example, the methyl methacrylate or the alkyl group has 1 carbon atom.
A method of synthesizing a macromer of any one of the alkyl (meth) acrylates No. to No. 12 and graft-polymerizing the macromer with a monomer constituting another polymer or copolymer; Or a polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group and having an azo group or an alkyl (meth) having 1 to 12 carbon atoms in the alkyl group. A) a copolymer of acrylates having an azo group is polymerized,
A method of polymerizing a monomer constituting another polymer or copolymer with the azo group as a starting point can be employed.

Further, a polymer composed of the above-mentioned methyl methacrylate, a polymer composed of an alkyl (meth) acrylate having 1 to 12 carbon atoms of the alkyl group or a carbon number of the above alkyl group previously obtained by ordinary radical polymerization or the like. 1 to 1
After polymerizing a copolymer comprising an alkyl (meth) acrylate of No. 2, the mixture is mixed and irradiated with ultraviolet light, an electron beam, radiation, or the like, whereby the polymer comprising methyl methacrylate and the carbon number of the alkyl group Or a method comprising block-polymerizing a polymer consisting of an alkyl (meth) acrylate having 1 to 12 or a copolymer consisting of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms.

The pressure-sensitive adhesive composition of the present invention is obtained by further mixing a tackifier resin with the block copolymer (I). The tackifying resin has poor compatibility with the polymer comprising methyl methacrylate. Specifically, the haze value of a mixture obtained by mixing 10 parts by weight of the tackifying resin with 100 parts by weight of the polymer composed of methyl methacrylate is preferably 15% or more. If it is less than 15%, the cohesive strength of the pressure-sensitive adhesive composition decreases. More preferably, it is at least 20%.

The haze value refers to the percentage of the amount of light scattered while passing through the sample when the sample formed into a film is irradiated with visible light. When the compatibility of the tackifier resin with the polymer comprising methyl methacrylate is excellent, the haze value is small, and when the compatibility is inferior, the haze value is large. For the above reasons, in the present invention, the haze value is preferably at least 15% or more, and the upper limit may be 100%.

The haze value is determined by coating a mixture of a polymer corresponding to the polymer composed of methyl methacrylate and the tackifying resin with a thickness of 50 μm on a transparent base film and drying the mixture. A three-layer composite film was prepared by laminating the films. The haze values of the composite film and the two base films used to produce the composite film were measured by a haze meter, and the haze of the composite film was measured. It is a value obtained by subtracting the haze value of the two base films from the value. The haze meter is not particularly limited, and examples thereof include TC-HIIIDP (manufactured by Tokyo Denshoku Co., Ltd.).

[0036] is not particularly restricted but includes specific examples of the tackifying resin, for example, C ₅ system (hydrogenated) petroleum resin, C ₉ type (hydrogenated) petroleum resin, (hydrogenated) rosin resin, (hydrogenated) Rosin ester resin, (hydrogenated) terpene resin, (hydrogenated) terpene phenolic resin, (hydrogenated) coumarone indene resin,
Disproportionated rosin resin, disproportionated rosin ester resin, polymerized rosin resin, polymerized rosin ester resin, and the like. These can be used alone or in combination of two or more.
Further, a tackifier resin compatible with the above-mentioned polymer composed of methyl methacrylate may be blended to such an extent that the cohesive force is not significantly reduced.

The amount of the tackifying resin is the total amount of the tackifying resin to be blended, and is the total amount of the block copolymer (I).
5 to 40 parts by weight per 100 parts by weight is preferred. If the amount is less than 5 parts by weight, no improvement in peeling resistance is observed, and if it exceeds 40 parts by weight, the performance of tackiness such as initial adhesiveness is reduced.

If necessary, a crosslinking agent, a filler, an antioxidant, an ultraviolet inhibitor, a metal carboxylate, etc. are added to the pressure-sensitive adhesive composition of the present invention as long as the pressure-sensitive adhesive performance is not impaired. be able to.

The crosslinking agent is not particularly limited. For example, N, N'-hexamethylene-1,6-bis (1-aziridinecarbamide), N, N'-diphenylmethane-1,6-bis (1 Aziridine compounds having two or more functions, such as trimethylol-tri-β-aziridinylpropionate; isocyanate compounds such as hexamethylene diisocyanate and tolylene diisocyanate adduct of trimethylolpropane;
Epoxy resins such as N, N ', N',-tetraglycidyl-m-xylenediamine; alkyl etherified melamine resins; polyvalent metal salts; metal chelates; 1,6-hexanediol di (meth) acrylate, trimethylolpropane Bifunctional or higher functional (meth) acrylates such as ethylene oxide-modified triacrylate are exemplified.

The filler is not particularly restricted but includes, for example, calcium carbonate, titanium oxide, mica, talc and the like. The antioxidant is not particularly limited,
For example, a phenol type, an amine type and the like can be mentioned.

The ultraviolet ray inhibitor is not particularly limited, and examples thereof include benzotriazole-based ones. The metal carboxylate is not particularly limited, and includes, for example, sodium stearate, magnesium stearate, calcium stearate, zinc stearate, barium stearate, sodium palmitate and the like.

The pressure-sensitive adhesive composition of the present invention can be suitably used, for example, as a pressure-sensitive adhesive layer of a pressure-sensitive adhesive tape or a pressure-sensitive adhesive sheet. The pressure-sensitive adhesive tape or the pressure-sensitive adhesive sheet can be obtained, for example, by applying the pressure-sensitive adhesive composition of the present invention to one or both surfaces of a substrate to form a pressure-sensitive adhesive layer.

The coating method is not particularly limited.
For example, a solution coating method in which the composition is dissolved in a solvent and then applied using a roll coating machine or the like; a hot melt coating method in which the composition is applied using an extruder or the like in a non-solvent state can be adopted, but environmental pollution can be adopted. From the viewpoints of prevention, energy saving, resource saving, and the like, application by a hot melt coating method is preferable.

The substrate is not particularly limited, and examples thereof include paper; nonwoven fabric; synthetic resin films such as polyester resin and polyolefin resin; and synthetic resin foams such as polyurethane resin, polychloroprene resin, and acrylic resin. .

Further, by forming only the pressure-sensitive adhesive composition of the present invention into a sheet, a non-support type double-sided pressure-sensitive adhesive tape having no base material layer can be obtained.

The pressure-sensitive adhesive composition of the present invention contains, as a tackifying resin, a resin having poor compatibility with the above-mentioned methyl methacrylate polymer, so that the domain structure of the above-mentioned methyl methacrylate polymer is as follows.
It is not plasticized by the compounded tackifying resin. Therefore, the peeling resistance to all kinds of adherends can be increased without reducing the cohesive force of the pressure-sensitive adhesive composition.

[0047]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 (1) Synthesis of polymer Synthesis of ABA type block copolymer 70 parts by weight of n-butyl acrylate, 0.2 part by weight of N, N-diethyldithiocarbamate as an initiator, 30 parts by weight of ethyl acetate as a solvent was charged into a three-necked flask, and after purging with nitrogen for 20 minutes, a 10-watt UV lamp was irradiated for 48 hours while rotating a stirring blade using a three-one motor, to form a B block. Polymerization was performed. After completion of the reaction, the absence of vinyl groups in the reaction product was confirmed by NMR.

To the obtained reaction product, 30 parts by weight of methyl methacrylate and 20 parts by weight of ethyl acetate as a solvent were added and irradiated with a 10 watt UV lamp for 48 hours.
A block in which the A block is block-copolymerized into the B block, wherein the A block is a methyl methacrylate polymer and the B block is an n-butyl acrylate polymer
Block copolymers were synthesized. After completion of the reaction, the absence of vinyl groups in the reaction product was confirmed by NMR. The weight average molecular weight of the obtained block copolymer is represented by G
It was measured with a PC (LC-9A, manufactured by Shimadzu Corporation).
The results are shown in Table 1.

Synthesis of polymer for measuring haze value 70 parts by weight of methyl methacrylate were mixed with N,
0.4 parts by weight of N-diethyldithiocarbamate and 30 parts by weight of ethyl acetate as a solvent were charged into a three-necked flask, purged with nitrogen for 20 minutes, and then rotated by a stirring blade using a three-one motor to obtain a UV light of 10 watts.
A lamp was irradiated for 48 hours to polymerize a polymer composed of methyl methacrylate, thereby synthesizing a polymer for measuring a haze value. After completion of the reaction, the absence of vinyl groups in the reaction product was confirmed by NMR. The weight average molecular weight of the obtained polymer for measuring a haze value was measured by GPC (LC-9A, manufactured by Shimadzu Corporation). The results are shown in Table 1.

(2) Preparation of Sample for Measurement Preparation of Tape for Measurement of Physical Properties To 100 parts by weight of the obtained block copolymer, 20 parts by weight of a tackifier resin (Pencel D125, manufactured by Arakawa Chemical Industry Co., Ltd.) were added and stirred. The mixture was uniformly applied to a polyester film (thickness: 38 μm, manufactured by Teijin Limited) having a corona-treated surface, and applied at 110 ° C. ×
After drying for 5 minutes, an adhesive tape having an adhesive layer thickness of 50 μm was prepared.

Preparation of sample for measuring haze value To 100 parts by weight of the obtained polymer for measuring haze value, 10 parts by weight of a tackifier resin (Pencel D125, manufactured by Arakawa Chemical Industry Co., Ltd.) was added, and the mixture was stirred and uniformly mixed. The product was applied on a release-treated polyester film (# 3811, thickness 38 μm, manufactured by Lintec Co., Ltd.) as a base film using an applicator, and dried at 110 ° C. for 5 minutes.
A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer thickness of 50 μm was obtained, and a base film was further laminated thereon to obtain a composite film.

Using the obtained pressure-sensitive adhesive tape and composite film, SP pressure-sensitive adhesive strength, holding power, and haze value
It was evaluated by the following method. The results are shown in Table 1.

Evaluation method SP adhesive strength According to JIS Z 0237, the obtained adhesive tape was applied to each of a SUS304 plate and a polypropylene plate with a width of 20 mm and a 2 kg rubber roller.
After affixed by a reciprocating load and allowed to stand at 23 ° C. for 20 minutes, a tensile speed of 10 m
The peel strength was measured under the conditions of m / min and 300 mm / min.

2. Retention force According to JIS Z 0237, width 20 mm, length 1
The adhesive tape cut to 00 mm was adhered to a SUS304 plate having a thickness of 1.5 mm, a width of 25 mm and a length of 100 mm with an adhesive length of 20 mm and a reciprocating load of 2 kg with a 2 kg rubber roller. 20 in the atmosphere
After leaving it for 60 minutes, leave it in a 60 ° C atmosphere for 20 minutes, suspend the adhesive tape vertically, hang it vertically in a constant temperature dryer at 60 ° C, and apply a load of 1 kg to the lower end of the adhesive tape. The sample was allowed to stand, and a shift distance (mm) after 1 hour was measured.

3. Haze value Each of the obtained composite film and base film was cut into 30 × 30 mm, and their haze values were measured using a haze meter (TC-HIIIDP, manufactured by Tokyo Denshoku Co., Ltd.). From the haze value of the base film.

Example 2 An adhesive tape and a composite film were obtained and evaluated in the same manner as in Example 1 except that Superester A125 (manufactured by Arakawa Chemical Industry Co., Ltd.) was used as a tackifier resin. The results are shown in Table 1.

Example 3 An adhesive tape and a composite film were obtained and evaluated in the same manner as in Example 1 except that Nicanol HP120 (manufactured by Mitsubishi Gas Chemical Company) was used as the tackifying resin. Table 1 shows the results
It was shown to.

Comparative Example 1 A pressure-sensitive adhesive tape and a composite film were obtained and evaluated in the same manner as in Example 1 except that no tackifier resin was blended. The results are shown in Table 1.

Comparative Example 2 An adhesive tape and a composite film were obtained and evaluated in the same manner as in Example 1 except that Superester A100 (manufactured by Arakawa Chemical Industries) was used as the tackifying resin. The results are shown in Table 1.

Comparative Example 3 An adhesive tape and a composite film were obtained and evaluated in the same manner as in Example 1 except that FTR6125 (manufactured by Mitsui Toatsu Chemicals) was used as the tackifying resin. The results are shown in Table 1.

[0062]

[Table 1]

[0063]

Since the pressure-sensitive adhesive composition of the present invention has the above-mentioned constitution, it exhibits excellent cohesion while maintaining the balance of pressure-sensitive adhesive properties, and exhibits excellent peel resistance regardless of the type of adherend. be able to. In addition, since the pressure-sensitive adhesive composition of the present invention contains a block copolymer as a main component, solventless coating is possible, and simplification of a manufacturing process such as omitting a drying process can be achieved. .

Claims (2)

[Claims] 1. A pressure-sensitive adhesive composition comprising a block copolymer (I) having a polymer comprising methyl methacrylate and a tackifier resin, wherein said block copolymer (I) has a general formula (A) -B) a block copolymer represented by aA, a block copolymer represented by general formula (BA) bB, and a block copolymer represented by general formula (AB) c Group (1) of a block copolymer having a linear structure constituted by a polymer, a block copolymer represented by the general formula (AB) dX, and a general formula Ae-T A group (2) of block copolymers having a comb-shaped structure or a star-shaped structure composed of a block copolymer represented by -Bf 2, and the block copolymer group (1) and the block copolymer Selected from the group consisting of the two groups of the polymer group (2) At least one block copolymer, the tackifying resin, the adhesive composition characterized in that it is inferior in compatibility with the polymer consisting of the methyl methacrylate. In the formula, A represents a polymer composed of methyl methacrylate. B represents a polymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms or a copolymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms. a, b, c
Represents the same or different and represents an integer of 1 to 10. d is
Represents an integer of 3 to 7. e and f are the same or different and 1
It represents the above integer and satisfies the relationship of e + f = 3-7. X
Represents a polyfunctional compound capable of binding d polymers ((AB) d). T represents a polyfunctional compound capable of bonding the polymer represented by A and the polymer represented by B. 2. A polymer 1 comprising methyl methacrylate
The pressure-sensitive adhesive composition according to claim 1, wherein a haze value of a mixture obtained by mixing 10 parts by weight of a tackifier resin with respect to 00 parts by weight is 15% or more.