WO2007029783A1

WO2007029783A1 - Acrylic adhesive composition and adhesive product

Info

Publication number: WO2007029783A1
Application number: PCT/JP2006/317767
Authority: WO
Inventors: Yoshihiro Morishita; Tetsuya Kunimune; Kenichi Hamada
Original assignee: Kuraray Co., Ltd.
Priority date: 2005-09-07
Filing date: 2006-09-07
Publication date: 2007-03-15
Also published as: JPWO2007029783A1

Abstract

Disclosed are an adhesive composition having excellent weather resistance, heat resistance and water resistance, and an adhesive product. Specifically disclosed is an adhesive composition containing an acrylic block copolymer and an adhesiveness-imparting resin having a solubility parameter value of 8-11. The acrylic block copolymer contains 23-98% by mass of at least one polymer block (A) composed of an alkyl methacrylate unit such as methyl methacrylate and 77-2% by mass of at least one polymer block (B) composed of an alkyl acrylate unit such as octyl acrylate wherein an alkyl group has 6-18 carbon atoms, while having a weight average molecular weight of 5,000-1,000,000 and a molecular weight distribution of 1.0-1.5. Also specifically disclosed is an adhesive product having an adhesive layer composed of such an adhesive composition.

Description

Acrylic adhesive composition and adhesive product

Technical field

[0001] The present invention relates to a pressure-sensitive adhesive composition comprising a specific (meth) acrylic block copolymer and excellent in weather resistance, heat resistance, and water resistance.

Background art

[0002] Acrylic adhesives are widely used in adhesive tapes, adhesive sheets, and the like because they have superior weather resistance and heat resistance compared to rubber adhesives. The acrylic copolymer used as the base polymer of the acrylic adhesive is usually a random copolymer produced by a radical polymerization method. The molecular weight distribution [weight average molecular weight (Mw) Z number average molecular weight (Mn) ] Is generally as wide as about 2.0 to 5.0. Therefore, a low molecular weight component is mixed, and the pressure-sensitive adhesive containing the acrylic copolymer has a problem that the cohesive force is insufficient under a high temperature condition or adhesive residue is generated on the adherend due to cohesive failure. It was. To solve these problems, there is a method to increase the degree of polymerization of the polymer as a means of improving the cohesive strength under high temperature conditions. However, in the industrial industry, the limiting power of polymerization technology and coating technology is increased. There is a limit, and it has not yet been solved. As another means for improving the cohesive force, there is a method of crosslinking the polymer. However, when a random copolymer produced by a conventional radical polymerization method is used, the cross-linking site cannot be controlled, and the coagulation site cannot be controlled. Even if the force was improved, there was a problem that the adhesive strength was lowered.

[0003] On the other hand, an attempt has been made to use an acrylic block copolymer that can be synthesized by a living polymerization method as a base polymer. For example, there are the following reports.

[0004] In Patent Document 1, an iniferter such as xylylene-bis (N, N-jetyldithiocarbamate), xylylenebis (N-carbazolyldithiocarbamate) is used. A block copolymer having a polymer block having an alkyl ester power and a polymer block having an alkyl ester power is synthesized by a fy-fater polymerization method, and the block copolymer is used as a base for an adhesive. Proposed for use as a polymer [0005] In Patent Document 2 and Patent Document 3, a polymer block having mainly a methacrylic acid alkyl ester power, a glass transition temperature of + 110 ° C or higher, and a syndiotacticity of 70% or higher is mainly used. A block copolymer having a polymer block having a glass transition temperature of + 30 ° C. or lower and a polymer block having a glass transition temperature of + 30 ° C. or less has been proposed as a base polymer for pressure-sensitive adhesives. The

[0006] In Patent Document 4, an acrylic block copolymer is synthesized by performing an ester exchange reaction in the presence of an acid on a polymer synthesized by a char-on polymerization method, and the block copolymer is tackified. A pressure-sensitive adhesive composition made of a resin has been proposed.

Patent Document 1: Japanese Patent Application Laid-Open No. 2-103277

Patent Document 2: JP-A-11-302617

Patent Document 3: Japanese Patent Laid-Open No. 11-323072

Patent Document 4: U.S. Patent No. 6734256

[0008] When an acrylic block copolymer is used as a base polymer, the formation of a phase separation structure of polymer blocks having different glass transition temperatures makes it possible to physically form a polymer block having a high glass transition temperature. It becomes a crosslinking point and develops cohesive force. However, the pressure-sensitive adhesive contained in these acrylic block polymers melts at the crosslinking point under high temperature conditions, and a sufficient cohesive force is obtained.

Disclosure of the invention

Problems to be solved by the invention

[0009] Accordingly, an object of the present invention is to provide a pressure-sensitive adhesive composition and a pressure-sensitive adhesive product having excellent weather resistance and heat resistance.

Means for solving the problem

[0010] The present inventors have intensively studied to solve the above problems. As a result, it was found that by using a specific acrylic block copolymer, an adhesive composition and an adhesive product excellent in weather resistance and heat resistance could be provided, and the present invention was completed.

[0011] That is, the present invention provides:

At least one polymer block (A) composed of methacrylic acid alkyl ester units (A) 23 to 98% by mass, and alkyl acrylate ester having 6 to 18 carbon atoms At least one polymer block (B) having a potential of 77 to 2% by mass, a weight average molecular weight force of 5,000 to 1,000,000, and a molecular weight force of S1.0 to 1.5 100 parts by weight of an alkynele block copolymer; and

A tackifier resin having a solubility parameter value of from 8.0 to 11.0;

Is a pressure-sensitive adhesive composition containing

[0012] Further, the present invention is an adhesive product having an adhesive layer comprising the above-mentioned adhesive composition.

The invention's effect

[0013] The pressure-sensitive adhesive composition of the present invention contains a specific acrylic block copolymer and a specific tackifier resin, and has excellent weather resistance, heat resistance, water resistance, and transparency. Furthermore, the pressure-sensitive adhesive composition of the present invention can use a tackified resin that has been conventionally restricted in use due to different compatibility, and is intended for use such as the type of adherend and required transparency. Many types of tackifiers can be selected depending on. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a pressure-sensitive adhesive and a pressure-sensitive adhesive product that can have excellent adhesive performance over a long period of time even under an environment exposed to ultraviolet rays or under high temperature and high humidity usage conditions.

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] The present invention is described in detail below. In this specification, methacryl and acryl may be collectively referred to as “(meth) acryl”. In the present invention, “adhesive” means “pressure-sensitive adhesive”.

[0015] The acrylic block copolymer used in the present invention is an at least one polymer block (A) composed of alkyl ester methacrylate units, and an alkyl group having 6 to 18 carbon atoms. It has at least one polymer block (B) having an acrylic acid alkyl ester unit strength. The acrylic block copolymer has a polymer block (A) composed of alkyl methacrylate units of “A”; a polymer block (B) composed of alkyl acrylate units of “B”; General formula;

(A-B)

(A-B) A

B- (AB) (n is an integer of 1 10).

[0016] Examples of the alkyl ester that is a structural unit of the polymer block (A) in the above general formula include, for example, methyl methacrylate, ethyl acetate, n-propyl methacrylate, isopropyl methacrylate, and n-methacrylate. Butyl, isobutyl methacrylate, sbutyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, tridecyl methacrylate, Examples thereof include alkyl methacrylates such as stearyl methacrylate, isoborn methacrylate, benzyl methacrylate, and methacrylate. Among them, when selected from methyl methacrylate and isobornyl methacrylate, the glass transition temperature of the polymer block (A) increases, and when it is used as a pressure-sensitive adhesive composition, it exhibits high cohesive strength at high temperatures. preferable. Further, in the case of methyl methacrylate, the phase separation between the polymer block (A) and the polymer block (B) becomes clear. preferable. These can be used alone or in combination.

[0017] Examples of the acrylic acid alkyl ester having an alkyl group having 618 carbon atoms, which is a structural unit of the polymer block (B) in the above general formula, include, for example, n-xyl acrylate, cyclohexyl acrylate, acrylic Examples include 2-ethylhexyl acid, n-octyl acrylate, lauryl acrylate, tridecyl acrylate, and stearyl acrylate. Among them, when selected from 2-ethylhexyl acrylate, n-octyl acrylate, and tridecyl acrylate, the adhesive block having a low glass transition temperature of the polymer block (B) is highly adhesive. It is preferable at the point which expresses force. Furthermore, in the case of 2-ethylhexyl acrylate, since the phase separation between the polymer block A and the polymer block (B) becomes clearer, it is more preferable in terms of expressing a high cohesive force. These may be used alone or in combination of two or more. These may be used alone or in combination of two or more. In particular, when 2-ethylhexyl acrylate and n-octyl acrylate are selected, the glass transition temperature of the polymer block (B) is 50 ° C or lower, and adhesion at low temperatures (10 ° C 40 ° C) is achieved. It is preferable in terms of excellent properties (tack, adhesive strength, etc.). Even when peeling at a high speed (for example, lmZ min to 100 mZ min), a slip stick phenomenon (maintaining a certain distance during peeling) A phenomenon that suddenly peels off or stops. It is also called zibbing phenomenon. This may cause problems such as equipment troubles due to fluctuations in peeling stress and adhesive residue on the adherend. )

広 Wide! で This is preferable because it exhibits stable adhesive strength under peeling speed conditions.

[0018] Examples of the block copolymer represented by the above general formula include, for example, polymethyl methacrylate b poly n-hexyl acrylate, polymethyl methacrylate b 2-ethylhexyl acrylate, polymethacrylic acid Methyl b-polyacrylate lauryl, polymethyl methacrylate b Polyacrylate 2-ethylhexyl b Polymethyl methacrylate, polyethyl acrylate 2-ethylhexyl b Polymethyl methacrylate b Polyethyl acrylate 2-ethylhexyl Etc.

[0019] The polymer block (A) and the polymer block (B) represented by the general formula described above have a small proportion (20% by mass or less in the polymer block) without impairing the effects of the present invention. ), Other monomer units may be included. Examples of the monomer unit that may be contained include methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, jetylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth ) Acrylic acid 2-aminoethyl, (meth) acrylic acid glycidyl, (meth) acrylic acid tetrahydrofurfuryl, etc. (meth) acrylic acid ester; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride Bull monomers having a carboxyl group such as acid, fumaric acid and (meth) acrylamide; Aromatic bullet monomers such as styrene, α-methylstyrene and ρ-methylstyrene; Conjugated monomers such as butadiene and isoprene; Ethylene, Olefin monomers such as propylene; ε-force prolatate , Rataton-based monomers such as Barerorataton and the like.

[0020] The method for producing the block copolymer used in the present invention employs a method according to a known method without particular limitation as long as a polymer satisfying the conditions of the present invention concerning the chemical structure is obtained. can do. Generally, as a method for obtaining a block copolymer having a narrow molecular weight distribution, a method in which a monomer as a constituent unit is subjected to living polymerization is employed. Examples of such living polymerization techniques include a method of polymerizing using an organic rare earth metal complex as a polymerization initiator, and a mineral salt such as an alkali metal or alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator. Method of polymerizing in the presence of an organic alkali metal Examples thereof include a method in which a compound is used as a polymerization initiator and anion polymerization in the presence of an organoaluminum compound, an atom transfer radical polymerization (ATRP) method, and the like.

[0021] Among the above production methods, in the case of the anion polymerization method in the presence of an organoaluminum compound, a polymer having a narrower molecular weight distribution can be produced. The molecular structure of this is highly syndiotactic, and when it is used as an adhesive composition, it has the effect of increasing the cohesive strength at high temperatures. In addition, because living polymerization is possible under relatively mild temperature conditions, there is little environmental impact (mainly power used by the refrigerator to control the polymerization temperature) for industrial production. There is an advantage that can be done. From the above points, it is preferable that the block copolymer used in the present invention is produced by a method for polymerizing in the presence of an organoaluminum compound.

[0022] Further, as a method for producing the block copolymer used in the present invention, a method in which a monomer which is a constituent unit of the block copolymer is directly polymerized is preferable. After polymerizing an alkyl (meth) acrylate having an alkyl group capable of transesterification after a polymerization reaction of t-butyl (meth) acrylate, etc., p With any alcohol in the presence of an acid such as toluenesulfonic acid Although it can be synthesized by a transesterification reaction, a hydrolysis reaction that occurs as a side reaction of the transesterification reaction may generate a carboxylic acid group in the polymer, resulting in a decrease in water resistance.

[0023] Examples of the polymerization method in the presence of the above organoaluminum compound include an organolithium compound and the following general formula:

AIR'R ^ ³

(Wherein R ¹ R ² and R ³ are each independently an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an aryl group which may have a substituent. , An aralkyl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent or an N, N disubstituted amino group, or R ¹ is As described above, it represents any group, and R ² and R ³ together have a substituent and may represent a arylene dioxy group.

In the presence of the organoaluminum compound represented by the formula, an ether such as dimethyl ether, dimethoxyethane, diethoxyethane, 12 crown 4; Ethynoleamine, N, N, Ν ', Ν, monotetramethyleneethylenediamine, Ν, Ν, Ν', Ν ", Ν,, -pentamethyljetylenetriamine, 1, 1, 4, 7, 10 , 10 A method of polymerizing a (meth) acrylic acid ester by further using a nitrogen-containing compound such as hexamethyltriethylenetetramine, pyridine, 2,2′-dipyridyl, etc. can be employed.

[0024] Examples of the organic lithium compound include methyllithium, ethyllithium, η-propyl lithium, isopropyllithium, η-butynolethium, sec butynolelithium, isobutyllithium, tert-butyllithium, and n pentyllithium. , N-hexyllithium, tetramethylenedilithium, pentamethylenedilithium, hexamethylenedilithium, etc., alkyllithium and alkyldilithium; phenol lithium, mtrilyllithium, ptrilyllithium, xylyllithium, lithium naphthalene, etc. Aryl lithium and aryl dilithium; benzyl lithium, diphenylmethyl lithium, trityl lithium, 1,1-diphenyl 3-methylpentyl lithium, α-methylstyryl lithium, diisopropene benzene and Aralkyllithium and aralkyldilithium such as dilithium produced by the reaction of tillithium; lithium amides such as lithium dimethylamide, lithium jetylamide and lithium diisopropylamide; methoxylithium, ethoxylithium, η-poxoxy Lithium, isopropoxylithium, η butoxylithium, sec butoxylithium, tert butoxylithium, pentyllithium, hexyloxylithium, heptyllithium, octyloxylithium, phenoxylithium, 4 methylphenoxylithium, Examples thereof include lithium alkoxides such as benzyloxylithium and 4-methylbenzyloxylithium. These may be used alone or in combination of two or more.

[0025] The organoaluminum compounds represented by the above general formula include, for example, trimethyl aluminum, triethyl aluminum, tri-n-butyl aluminum, tri-s-butyl aluminum, tri-t-butyl aluminum, triisobutyl. Aluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-2-ethylhexylaluminum, trialkylaluminum such as triphenylaluminum, dimethyl (2,6 di-tert-butyl-4-methylphenoxy) aluminum , Dimethyl (2, 6 di-tert-butylphenoxy) aluminum, jetyl (2, 6 di-tert-butyl-4-methylphenoxy) aluminum, jetyl (2, 6 di-tert-butylphenoxy) aluminum, diisobutyl (2 , 6— Di-tert-butyl-4-methylphenoxy) aluminum, diisobutyl (2,6 di-te rt-butylphenoxy) aluminum, di-n-octyl (2,6 di-tert-butyl-4-methylphenoxy) Aluminum, dialkylphenoxyaluminum such as di-n-octyl (2,6ditert-butylphenoxy) aluminum, methylbis (2,6di-tert-butyl 4-methylphenoxy) aluminum, methylbis (2,6ditert- Butylphenoxy) aluminum, ethyl [2,2, monomethylenebis (4-methyl 6-tert-butylphenoxy)] aluminum, ethylbis (2,6 di-tert-butyl-4-methylphenoxy) aluminum, ethylbis (2,6 dione tert-Butylphenoxy) aluminum, ethyl [2, 2'-methylenebis (4-methyl 6-tert-butylphenoxy) )] Aluminum, isobutyl bis (2,6 di-tert-butyl-4-methylphenoxy) aluminum, isobutyl bis (2,6 di-tert-butylphenoxy) aluminum, isobutyl [2,2, -methylenebis (4- Methyl 6-tert-butylphenoxy)] aluminum, n-octylbis (2,6 di-tert-butyl 4-methylphenoxy) aluminum, n-octylbis (2,6 ditert-butylphenoxy) aluminum, n-octyl [2, 2 ' —Methylenebis (4-methyl-6-tert-butylphenoxy)] Alkyldiphenoxyaluminum such as aluminum, methoxybis (2,6-ditert-butyl-4-methylphenoxy) aluminum, methoxybis (2,6 di-tert —Butylphenoxy) aluminum, methoxy [2,2'-methylenebis (4-methyl-6-tert-butyl) Ruphenoxy)] aluminum, ethoxybis (2,6 di-tert-butyl-4-methylphenoxy) aluminum, ethoxybis (2,6 di-tert-butylphenoxy) aluminum, ethoxy [2,2'-methylenebis (4-methyl-6-) tert butylphenoxy)] aluminum, isopropoxybis (2,6 di-tert-butyl-4-methylphenoxy) aluminum, isopropoxybis (2,6 di-tert-butylphenoxy) aluminum, isopropoxy [2,2'-methylenebis ( 4-methyl-6-tert-butylphenoxy)] aluminum, tert-butoxybis (2,6 di-tert-butyl-4-methylphenoxy) aluminum, tert-butoxybis (2,6 di-te rt-butylphenoxy) aluminum, tert-Butoxy [2, 2, 1-methylenebis (4-methyl-6-tert-butyl Tilphenoxy)] alkoxydiphenoxyaluminum such as aluminum, tris (2,6-di-tert-butyl 4-methylphenoxy) aluminum, tris (2,6 -Triphenoxyaluminum such as (diphenyl-phenoxy) aluminum. Among these organoaluminum compounds, isobutylbis (2,6 di-tert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6 di-tert-butylphenoxy) aluminum, isobutyl [2,2'-methylenebis (4-methyl-) 6-tert butylphenoxy)] aluminum isotonic This is particularly preferred because it is easy to handle and allows the polymerization of the acrylate ester to proceed without deactivation under relatively mild temperature conditions. These may be used alone or in combination of two or more.

[0026] The overall weight average molecular weight (Mw) of the acrylic block copolymer used in the present invention is 5,000 to 1,000,000. When producing the pressure-sensitive adhesive composition, it is easy to mix with the tackifying resin S, point, force, power of 10,000 to 500,000 S, preferably 10,000 to 100,000 I like it!

[0027] The ratio (MwZMn) of the total weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic block copolymer used in the present invention is 1.0 to 1.5. In the case of a pressure-sensitive adhesive composition, it is preferably 1.0 to 1.4, more preferably 1.0 to 1.3, from the viewpoint of high cohesive strength at high temperatures.

[0028] The mass ratio of all the polymer blocks (A) and all the polymer blocks (B) in the acrylic block copolymer used in the present invention is excellent when a pressure-sensitive adhesive composition is used. From the point that it is possible to supply a block copolymer and a pressure-sensitive adhesive using the block copolymer in a form that has adhesiveness and is easy to handle, B) It is more preferable that the polymer block (A) is 30 to 70% by mass and the polymer block (B) 70 to 30% by mass is preferably 77 to 2% by mass! /. When the mass ratio of the polymer block (B) is less than 2%, it is preferable that the pressure-sensitive adhesive composition has low adhesiveness! / ヽ. In addition, when the mass ratio of the polymer block (B) is more than 77%, the block copolymer becomes a bale-like product, which is handled in the production of the block copolymer and an adhesive using the block copolymer. It becomes difficult.

[0029] The block copolymer used in the present invention can be processed into a form that is easy to handle. For example, by using a device in which an underwater cutter or a center hot cutter device is connected to a twin-screw extruder. Process and provide polymer in pellet form Is possible. Moreover, after cooling the strand which also produces the twin-screw extruder power, it can be cut with a strand cutter to obtain pellets. Polymers that are in the form of these pellets can be quantitatively fed by a pellet feeder and can increase the production efficiency of adhesives and adhesive products.

[0030] When the pressure-sensitive adhesive composition of the present invention is mixed with a tackifier resin, it is easy to adjust the tack, the adhesive force, and the holding force. Examples of the tackifier resin include natural resin such as rosin resin and terpene resin; petroleum resin, hydrogenated (hereinafter sometimes referred to as “hydrogenated”) petroleum resin, styrene resin Examples thereof include synthetic resins such as fat, coumarone indene resin, phenol resin, and xylene resin.

[0031] Examples of the rosin-based rosin include rosins such as gum rosin, tall oil rosin and wood rosin; modified rosins such as hydrogenated rosin, disproportionated rosin and polymerized rosin; glycerin esters of these rosins and modified rosins, Examples thereof include rosin esters such as pentaerythritol ester.

[0032] Examples of the terpene resin include terpene resin mainly composed of a-vinene, j8-vinene, dipentene, aromatic modified terpene resin, hydrogenated terpene resin, terpene phenol resin, etc. Can be given.

Examples of the above (hydrogenated) petroleum resin include, for example, (hydrogenated) aliphatic (C) petroleum resin, (hydrogenated)

Five

) Aromatic (C) Petroleum resin, (Hydrogenated) Copolymerized (C / C) Petroleum resin, (Hydrogenated)

9 5 9

Examples include pentagen-based petroleum resin and alicyclic saturated hydrocarbon resin.

Examples of the styrene resin include poly α-methyl styrene, α-methyl styrene styrene copolymer, styrene monomer モノマー aliphatic monomer copolymer, styrene monomer Ζ α-methyl styrene Ζ aliphatic monomer Copolymers, styrene monomer copolymers, styrene monomers, and aromatic monomer copolymers.

[0033] Among the above tackifying resins, terpene resin, rosin resin, (hydrogenated) petroleum resin, and styrene resin are particularly preferable because they exhibit high adhesive strength. From the viewpoint of excellent transparency, (hydrogenated) petroleum resin and styrene-based resin are more preferable. These may be used alone or in combination of two or more. The softening point of the tackifying resin is preferably 50 ° C. to 150 ° C. from the viewpoint of developing high adhesive strength. [0034] The solubility parameter value of the tackifying resin that can be used in the present invention is a viewpoint power that achieves both adhesive properties and high water resistance as an adhesive composition 8.0 to: L 1.0, and 8.0. -10. 4 is preferred 8.5 to 9.4 is more preferred.

[0035] As a method for determining the solubility parameter value of the tackifying resin, for example, a method of calculating from physical characteristics such as heat of evaporation, refractive index, Kauri-butanol number, surface tension, dipole efficiency, Fedors' formula, Examples include the method of calculating chemical yarns using the Small equation, the Hoy equation, etc., the method of measuring by a solubility test in a solvent whose solubility parameter value is known, and the cloud point titration method. In particular, a method of actual measurement by a point solubility test that is applicable even when the chemical structure is not single or unknown is preferable.

[0036] Specifically, when the tackifier resin is soluble in a solvent having a solubility parameter value of X, insoluble in a solvent having a solubility parameter value of power, and Y is a value greater than X. The solubility parameter value of the tackifier resin can be determined by rounding off the second decimal place, where X is Y. As the solubility parameter value of the solvent to be used, a known literature value can be adopted. For example, the value described in Journal of Paint Technology, 42 (541), pages 76-118 (1970) is adopted. be able to.

[0037] When the solubility parameter value is actually measured by a solubility test, the solvent to be used is preferably selected from hydrocarbon compounds, aromatic compounds, ester compounds, ketone compounds, nitrile compounds, alcohols, amines, etc. A solvent containing a functional group having an active proton is not preferable because the solubility is changed by hydrogen bonding.

[0038] The compounding amount of the tackifying resin can be appropriately selected according to the use of the pressure-sensitive adhesive, the type of adherend, and the like. From the viewpoint of improving the adhesive force and improving the coatability. In the agent composition, it is 1 part by mass or more and 400 parts by mass or less, and preferably 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the acryl-based block copolymer.

[0039] The pressure-sensitive adhesive composition of the present invention may contain various plasticizers as required! Examples of such plasticizers include, for example, phthalates such as dibutino phthalate, di n-octino phthalate, bis 2-ethylhexyl phthalate, di n-decyl phthalate, diisodecyl phthalate, bis 2 —Adipate esters such as ethylhexyl adipate and di n-octyl adipate, bis 2-ethylhexyl sebacate, di n-butyl sebacate Sebacic acid esters such as bis-2-ethylhexylazelate, etc. Fatty acid esters such as azelineic acid esters such as bis-2-ethylhexylase; Norafins such as chlorinated paraffin; Glycols such as polypropylene glycol; Epoxidized soybean oil, Epoxy Epoxy polymer plasticizers such as modified amide oil; Phosphate esters such as trioctyl phosphate and triphenyl phosphate; Phosphites such as triphenyl phosphite; Adipic acid and 1,3-butylene glyco —Ester oligomers such as esters with poly (ethylene); acrylic oligomers such as poly (meth) acrylic acid _n -butyl and poly (meth) acrylic acid 2-ethylhexyl; polybutene; polyisobutylene; polyisoprene; process Oils, such as naphthenic oils, which can be used alone or in a mixture I can. The amount of plasticizer used is generally 80% by mass or less of the plasticizer in the pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition of the present invention may contain various additives as necessary. Examples of such additives include antioxidants and ultraviolet absorbers for further improving weather resistance, heat resistance, and acid resistance; inorganic powders such as calcium carbonate, titanium oxide, my strength, and talc. Examples of fillers include fibrous fillers such as glass fibers and organic reinforcing fibers.

[0040] The method for producing the pressure-sensitive adhesive composition of the present invention is not particularly limited. For example, each component is usually used by using a known mixing or kneading apparatus such as a kneader-louder, an extruder, a mixing roll, a Banbury mixer, or the like. It can be produced by mixing at a temperature in the range of 100 ° C to 250 ° C. Alternatively, the components may be prepared by dissolving and mixing each component in an organic solvent and then distilling off the organic solvent.

[0041] An adhesive product obtained by forming an adhesive layer comprising the adhesive composition of the present invention on a substrate includes an adhesive sheet (including an adhesive film), an adhesive tape, a pressure sensitive tape, and masking. Examples include tapes, electrical insulating tapes, laminating films, medical poultices, decorative adhesive sheets, and adhesive optical films.

[0042] When the pressure-sensitive adhesive composition of the present invention is in a molten state, it has a film shape, a sheet shape, a tape shape or other desired shape, paper, paper board, cellophane, organic polymer film 'sheet, cloth, wood, The adhesive product can be produced by coating on a substrate such as metal and then cooling. In addition, the pressure-sensitive adhesive composition of the present invention can be dissolved in a solvent such as toluene to form a solution and used as a solvent-type pressure-sensitive adhesive. You may manufacture said adhesive product by making it emit.

Example

[0043] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the following examples.

[0044] The block copolymers used in Examples and Comparative Examples were synthesized according to the following Synthetic Examples and Comparative Synthetic Examples using chemicals dried and purified by a conventional method. At that time, the measurement of the polymerization conversion and the analysis of the synthesized block copolymer were carried out by the following methods.

[0045] (1) Measurement of number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) by gel permeation chromatography (GPC)

Equipment: Gel permeation chromatograph (HLC-8020) manufactured by Tosoh Corporation

Column: Tosohichi TSKgel GMHXL, G4000HXL and G5000HXL connected in series

Eluent: Tetrahydrofuran

Eluent flow rate: 1. OmlZ min

Column temperature: 40 ° C

Detector: Differential refractive index (RI) meter

Calibration curve: Calibration using standard polystyrene

[0046] (2) Measurement of the content of each copolymer component in the copolymer by proton nuclear magnetic resonance (NMR) spectroscopy

Equipment: JEOL Nuclear Magnetic Resonance Equipment CFNM-LA400)

Solvent: heavy black mouth form

[0047] (3) Measurement of monomer conversion rate by gas chromatography (GC)

Equipment: Gas chromatograph GC-14A, manufactured by Shimadzu Corporation

Column: INERT CAP 1 (df = 0.4 m, 0.25 mml. D. X 60 m) manufactured by GL Sciences Inc.

Analysis conditions: injection300 ° C, detecter300 ° C, 60 ° C (0 min hold) → 5 ° CZ min → 100 ° C (0 min hold) → 15 ° C, min → 300 ° C (2 min hold) [Synthesis Example 1] Synthesis of block copolymer 1

Attach 868 g of toluene, N, N, Ν ', Ν ", Ν" -pentamethylgerylenetriamine 3.80 g, isobutyl bis (2, 6 Di-tert-butyl 4-methylphenoxy) aluminum solution containing 40.2 mmol of toluene 60. Add Og, and then add cyclohexyl lithium and 7.03 mmol of cyclohexane and _n- hexane mixed solution 4. 13 g Was added. This was followed by methyl metatalate (1) 39. Og. The reaction solution was initially colored yellow and became colorless after stirring for 60 minutes at room temperature. At this point, the reaction solution lg was collected in a sampling container containing a small amount of methanol for analysis. As a result of GC measurement of the reaction solution, the conversion rate of methyl methacrylate was 100%. Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., and 234 g of 2-ethylhexyl acrylate was added dropwise over 2 hours. After completion of dropping, 1 g of the reaction solution was collected in a sampling container containing a small amount of methanol. As a result of GC measurement of the reaction solution, the conversion rate of 2-ethylhexyl acrylate was 100%. Subsequently, 39. Og of methyl methacrylate (2) was added thereto, and after stirring at room temperature, 3.5 g of methanol was added to terminate the polymerization reaction. As a result of GC measurement of the reaction solution, the conversion rate of methyl methacrylate was 100%. The obtained reaction solution was poured into a beaker containing 10 L of methanol to obtain a precipitate. This was vacuum-dried overnight at 60 ° C. to obtain 309 g of a white powdery polymer. This is referred to as Polymer 1.

[0049] As a result of ¹ H-NMR measurement and GPC measurement of the reaction solution and polymer 1 collected during the reaction, the finally obtained polymer 1 was polymethyl methacrylate-b polyacrylic acid 2- Tylhexyl b Polymethylmethacrylate triblock copolymer, Mn of polymethyl methacrylate block taken during the reaction is 6,300, Mw is 7,030, MwZMn is 1 Mn of polymethyl methacrylate-b polyhexyl acrylate collected during the reaction is 42,300, Mw is 43,800, and Mw ZMn is 1.04. The Mn of the finally obtained triblock body was 48,000, Mw was 50, 200, and MwZMn was 1.05. The proportion of each block polymethyl methacrylate (12.5 weight ^{_{0/0)-b-polyacrylic}} acid 2 hexyl Echiru (75.0 mass ^_0/0) b-polymethyl methacrylate (12.5 wt%) It turned out to be. [Synthesis Example 2] Synthesis of block copolymer 2

A 2-L three-necked flask was fitted with a three-way cock and the inside was replaced with nitrogen. At room temperature, toluene 868 g 1, 1, 4, 7, 10, 10 Hexamethyltriethylenetetramine 1.88 g, isobutyl bis (2, 6 (Butyl 4-methylphenoxy) aluminum 34.8 g of toluene solution containing 23.3 mmol was added, and 4.56 g of a mixed solution of cyclohexane and _n -xane containing 7.76 mmol sec butyllithium was added. This was followed by 67.2 g of methyl metatalate (1). The reaction solution was initially colored yellow and became colorless after stirring for 60 minutes at room temperature. At this point, the reaction solution lg was collected in a sampling container containing a small amount of methanol for analysis. As a result of GC measurement of the reaction solution, the conversion rate of methyl methacrylate was 100%. Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., and 312.8 g of 2-ethylhexyl acrylate was added dropwise over 2 hours. After completion of dropping, the reaction solution lg was collected in a sampling container containing a small amount of methanol. As a result of GC measurement of the reaction solution, the conversion rate of 2-ethylhexyl acrylate was 100%. Subsequently, 67.2 g of methyl methacrylate (2) was added thereto, and after stirring for 2 hours at room temperature, 3.5 g of methanol was added to terminate the polymerization reaction. As a result of GC measurement of the reaction solution, the conversion rate of methyl methacrylate was 100%. The obtained reaction solution was poured into a beaker containing 10 L of methanol to obtain a precipitate. This was vacuum-dried overnight at 60 ° C. to obtain 440 g of a white powdery polymer. This is designated as Polymer 2.

[0051] As a result of ¹ H-NMR measurement and GPC measurement of the reaction solution and polymer 2 collected during the reaction, the finally obtained polymer 1 was polymethyl methacrylate-b polyacrylic acid 2- Tylhexyl b Polymethyl methacrylate triblock copolymer, Mn of polymethyl methacrylate block taken during the reaction is 9,850, Mw is 11,000, and MwZMn is 1. Mn of polymethyl methacrylate-b-polyethylhexyl acrylate collected during the reaction was 51,000, Mw was 51,900, MwZMn was 1.02, and the final The Mn of the triblock obtained as a result was 59,000, Mw was 60,600, and MwZMn was 1.03. The proportion of each block Porimetatari Le methyl (15.5 mass ^{_{0/0)-b-polyacrylic}} acid 2 hexyl Echiru (69.0 mass ^_0/0) -b polymethyl methacrylate (15.5 wt%) It turned out to be. [Synthesis Example 3] Synthesis of block copolymer 3

A 3 L three-necked flask was fitted with a three-way cock, and the inside was replaced with nitrogen. At room temperature, 1040 g of toluene, 1, 1, 4, 7, 10, 10 2.45 g of hexamethylpolyethyleneteramine, isobutyl bis (2, 6 Di-t-butyl-4-methylphenoxy) aluminum solution containing 35.5 mmol of toluene 52.9 g was added, and then, butyllithium 7. 8. 87 mmol of cyclohexane and n-hexane mixed solution 5. 20g was added. Subsequently, 71.8 g of methyl methacrylate (1) was added thereto. The reaction solution was initially colored yellow and became colorless after stirring for 60 minutes at room temperature. At this point, the reaction solution lg was collected in a sampling container containing a small amount of methanol for analysis. As a result of GC measurement of the reaction solution, the conversion rate of methyl metatalate was 100%. Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., and 468 g of 2-ethylhexyl acrylate was added dropwise over 3 hours. After completion of dropping, the reaction solution lg was collected in a sampling container containing a small amount of methanol. As a result of GC measurement of the reaction solution, the conversion rate of 2-ethylhexyl acrylate was 100%. Subsequently, 71.8 g of methyl methacrylate (2) was added thereto, and after stirring for 2 hours at room temperature, 3.5 g of methanol was added to terminate the polymerization reaction. As a result of GC measurement of the reaction solution, the conversion rate of methyl methacrylate was 100%. The obtained reaction solution was poured into a beaker containing 15 L of methanol to obtain a precipitate. This was vacuum-dried overnight at 60 ° C. to obtain 610 g of a white powdery polymer. This is designated as Polymer 3.

[0053] As a result of ¹ H-NMR measurement and GPC measurement of the reaction solution and polymer 3 collected during the reaction, the finally obtained polymer 3 was polymethyl methacrylate-b polyacrylic acid 2 Ruhexyl b Polymethyl methacrylate triblock copolymer, Mn of polymethyl methacrylate block taken during the reaction is 8,200, Mw is 9,400, and MwZMn is 1. Mn of polymethyl methacrylate-b polyhexyl acrylate collected during the reaction is 51, 000, Mw is 54,000, Mw ZMn is 1.06, and the final The Mn of the triblock obtained as a result was 60,000, Mw was 64,000, and MwZMn was 1.08. The proportion of each block polymethyl methacrylate (11.5 weight ^{_{0/0)-b-polyacrylic}} acid 2 hexyl Echiru (76.5 mass ^_0/0) b-polymethyl methacrylate (12.0 wt%) It turned out to be. [Comparative Synthesis Example 1] Synthesis of block copolymer 4

305 g of a polymer was obtained in the same manner as in Synthesis Example 1 except that 2-ethylhexyl acrylate was changed to n-butyl acrylate. This is designated as Polymer 4.

[0055] As a result of ¹ H-NMR measurement and GPC measurement of the reaction solution and the polymer 4 collected during the reaction, the finally obtained polymer 4 was polymethyl methacrylate-b-polyacrylic acid n- Petroleum b—polymethyl methacrylate triblock copolymer. Mn of polymethyl methacrylate block collected during the reaction is 6,700, Mw is 7,300, Mw / M n The Mn of polymethyl methacrylate-b-polyacrylate n-butyl collected during the reaction is 58,000, Mw is 61,000, and Mw / Mn¾l.05. The resulting triblock Mn was 64,900, Mw was 68,100, and Mw ZMn was 1.03. The proportion of each block polymethyl methacrylate (12.5 weight ^_0/0) - b-polyacrylic acid n- butyl (75.0 weight ^{_{0/0)-b-polymethyl}} methacrylate (12.5 wt%) It turned out to be.

[0056] [Comparative Synthesis Example 2] Synthesis of block copolymer 5

435 g of a polymer was obtained in the same manner as in Synthesis Example 2 except that 2-ethylhexyl acrylate was changed to n-butyl acrylate. This is designated as Polymer 5.

[0057] As a result of ¹ H-NMR measurement and GPC measurement of the reaction solution and the polymer 5 collected during the reaction, the finally obtained polymer 5 was polymethyl methacrylate-b-polyacrylic acid n- Petroleum b—polymethyl methacrylate triblock copolymer. Mn of the polymethyl methacrylate block collected during the reaction is 9,720, Mw is 10,400, MwZ Mn is 1 Mn of poly (methyl methacrylate) -b-polytalylate n-butyl collected during the reaction was 61, 100, Mw was 67, 200, and Mw / Mn was 1.10. The Mn of the finally obtained triblock body was 69,600, Mw was 76,900, and MwZMn was 1.11. The proportion of each block is polymethyl methacrylate (14.9 mass. / ₀ ) —b—poly (n-butyl acrylate) (70.2 mass%) — b—polymethyl methacrylate (14.9 mass%) It turned out to be.

[0058] [Comparative Synthesis Example 3] Synthesis of block copolymer 6

Same as Synthesis Example 3 except that 2-ethylhexyl acrylate was changed to n-butyl acrylate. In this way, 600 g of a polymer was obtained. This is designated as Polymer 6.

[0059] As a result of ¹ H-NMR measurement and GPC measurement of the reaction solution and the polymer 6 collected during the reaction, the finally obtained polymer 6 was polymethyl methacrylate-b-polyacrylic acid n- Petroleum b—polymethyl methacrylate triblock copolymer. Mn of polymethyl methacrylate block collected during the reaction is 7,600, Mw is 8,800, and MwZMn is 1 15 and poly (methyl methacrylate) b-polyacrylic acid n-butynole collected in the middle of reaction 61, 400, Mwi 69, 100, Mw / Mni 1. 13. The resulting triblock Mn was 64,000, Mw was 76,100, and Mw ZMn was 1.19. The proportion of each block polymethyl methacrylate (11.9 weight ^_0/0) - b-polyacrylic acid n- butyl (76.2 weight ^{_{0/0)-b-polymethyl}} methacrylate (11.9 wt%) It turned out to be.

[0060] The tackifier resin used in Examples and Comparative Examples is described below.

Product name “Rikatak F105” manufactured by Riyaku Finetech: Hydrogenated rosin ester-based resin Product name “Likatak F85” Riyaku Finetech manufactured by hydrogenated rosin ester-based resin: Alcon P100 Arakawa Chemical Manufactured by Kogyo Co., Ltd .: Alicyclic saturated hydrocarbon resin Product name `` Arcon M100 '' Arakawa Chemical Industries: Alicyclic saturated hydrocarbon resin product name `` KE311 '' Arakawa Chemical Industries: Special rosin ester resin

Product name "Super Ester Al 15" Arara 11 Chemical Industry Co., Ltd .: Special rosin ester resin product Product name "Maru Power Let's H505" Maruzen Petrochemical Co., Ltd .: Hydrogenated oil resin

Product name `` Ligalite R100 '' manufactured by Eastman Chemical: Hydrogenated alicyclic saturated hydrocarbon resin

Product name "Clearon M105" Yasuhara Chemical Co., Ltd .: hydrogenated terpene-based resin

[0061] Further, for the examples and comparative examples, the production of the adhesive tape and the evaluation of various physical properties were carried out by the following methods.

[0062] (1) Method of making adhesive tape:

Dissolve the block copolymer and tackifier resin in the blending mass ratios listed in Tables 1 and 3 in toluene to make a 40% strength by weight adhesive toluene solution, and coat it on the polyethylene terephthalate film with a coater. After coating, the film is placed at 160 ° C, 30 Dry and heat-treat in minutes to create a tape for evaluating adhesive properties. When it was necessary to apply the tape to the adherend in the evaluation of the tape prepared, the 2 kg roller was applied by reciprocating twice at a speed of 10 mm / min, and the evaluation was performed after storing at room temperature for 24 hours.

[0063] (2) Holding power test:

Measured according to JIS Z0237. In other words, the prepared adhesive tape was affixed to a stainless steel (SU S304) plate at 25mm x 25mm, and then the sample was stored for 24 hours at room temperature, then the load lkg was suspended at 120 ° C and the drop time was determined. It was.

[0064] (3) Holding power test under high humidity:

The prepared adhesive tape is affixed to a stainless steel (SUS304) plate at 25 mm x 25 mm, and then the sample is stored at room temperature for 24 hours, then a load of 500 g is suspended at a temperature of 80 ° C and a humidity of 90% for 94 hours. The length of the later shift was measured.

[0065] (4) 180 ° peel adhesion test:

Measured according to JIS Z0237. In other words, the prepared adhesive tape with a width of 25 mm and a length of 100 mm was affixed to a stainless steel (SUS304) plate and a polyethylene sheet of about 1 mm thickness, and then the sample was stored at room temperature for 24 hours. Measurement was performed by peeling in the direction of 180 ° at a speed of 300 mm Z at ° C.

[0066] (5) Measurement of shear bond failure temperature (SAFT):

Measured according to ASTM D4498. That is, cut the produced adhesive tape to a width of 25 mm, attach it to a stainless steel (SUS304) plate at 25 mm X 25 mm, leaving a portion where the weight is clamped, and then store the sample at room temperature for 24 hours. Placed in C oven and clamped 500g weight. The oven temperature is then increased from 40 ° C to 220 ° C at a rate of 30 ° CZ time. The sample force was also recorded as the temperature when the weight dropped.

[0067] (6) Compatibility test with tackifying resin:

The block copolymer and tackifier resin having the blending mass ratio shown in Table 2 were dissolved in toluene to prepare a 40% by weight concentration adhesive toluene solution, and a cast sheet having a thickness of about 1 mm was prepared. From the transparency of the obtained cast sheet and the presence or absence of the phenomenon of tensile whitening, ◎: transparent and without tensile whitening;

◯: Slightly transparent and with tensile whitening; Δ: Opaque and tensile whitening;

X: Separate into macros;

Compatibility was evaluated on the basis of cocoon.

[0068] (7) Water resistance evaluation (in-water immersion test and haze measurement):

Dissolve the block copolymer and tackifier resin in the blending mass ratio shown in Table 3 in toluene to prepare a 40% strength by weight adhesive toluene solution, and distill off the solvent under reduced pressure to obtain the adhesive composition. This was hot-pressed at 200 ° C. to produce a 20 cm × 20 cm × 1 mm press sheet. First, the haze of the press sheet was measured. Next, the press sheet was immersed in distilled water at room temperature for 90 minutes or 17 hours, and the haze of the press sheet after immersion was measured. The haze was measured according to JIS K7136.

[0069] (8) Calculation method of solubility parameter value of tackifier resin:

It was determined by a dissolution test in which 10 parts by mass of a tackified resin was mixed with 90 parts by mass of a solvent at room temperature for 24 hours. When the tackifier resin is soluble in a solvent having a solubility parameter value of X, the solubility parameter value is insoluble in a solvent of Y, and Y is a value greater than X, the tackifier resin Solubility parameter values were defined as XY. The values described in Non-Patent Document 2 were used as the solubility parameter values for each solvent. Table 1 shows the results of the dissolution test and the solubility parameter values.

[0070] [Table 1]

In Table 26, the composition of Example 13, Example 49, and Example 10 correspond to the composition of Comparative Example 13, Comparative Example 49, and Comparative Example 10, respectively. [Examples 1 to 3], [Reference Examples 1 and 2]

Including block copolymer 1 or block copolymer 2, low solubility parameter value in the examples! The pressure-sensitive adhesive composition containing the tackified rosin was evaluated. Table 2 shows the composition and evaluation results.

[0073] [Table 2]

[0074] [Comparative Examples 1 to 3], [Comparative Reference Examples 1 and 2]

Evaluation was made on a pressure-sensitive adhesive composition containing block copolymer 4 or block copolymer 5 and blended with a tackifier resin having a low solubility parameter value in a comparative example. Table 3 shows the composition and evaluation results.

[0075] [Table 3]

[Examples 4 to 9], [Reference Examples 3 and 4]

The compatibility of the pressure-sensitive adhesive composition containing block copolymer 1 and tackifier resin was evaluated. Table 4 shows the composition and evaluation results.

[0077] [Table 4]

[0078] [Comparative Examples 4 to 9], [Comparative Reference Examples 3 and 4]

The compatibility of the pressure-sensitive adhesive composition containing the block copolymer 4 and the tackifier resin was evaluated. Table 5 shows the composition and evaluation results.

[0079] [Table 5]

[Example 10], [Reference Examples 5 and 6]

The pressure-sensitive adhesive composition containing block copolymer 3 and blended with tackifier resin having a low solubility parameter value in the examples was evaluated. Table 6 shows the composition and evaluation results.

[0081] [Comparative Example 10], [Comparative Reference Examples 5 and 6]

An evaluation was made of an adhesive composition containing a block copolymer 6 and blended with a tackifier resin having a low solubility parameter value in a comparative example. Table 6 shows the composition and evaluation results.

[0082] [Table 6] Reference Example 5 Reference Example 6 Example 1 0 Comparative Reference Example 5 Comparative Reference Example 6 Comparative Example 10 Block Copolymer 3 100 100 100

Block copolymer 6 100 100 100 Adhesive composition

Superester A1 1 5 60 60 Archon M100 60 60 Adhesive thickness | // m 35 36 35 40 36 39 Appearance of adhesive tape Transparent Transparent Transparent Transparent Transparent White

180. Stripping vs. stainless steel N / 25mm 0.88 8.6 9.5 5.5 11 0.44 Adhesive strength vs. polyethylene N / 25mm 0.24 1.1 1.2 0.83 0.33 0.54 Shear bond breaking temperature (SAFT). C 196 157 178 156 136 134 Holding force under high humidity (80¾, 90%) Deviation, mm 0 0 0 0 1.3 4.7 Before water immersion 8 5 6 11 6 94 Haze value (1 mm thickness) After water immersion ( 90 minutes) 17 5 7 23 19 94 After flooding (17 hours) 30 16 22 86 55 94

[0083] As can be seen from the results in Table 2, it can be seen that the pressure-sensitive adhesive of the present invention is particularly excellent in cohesive force and transparency at high temperatures. In addition, when the tackifier resin defined in the present invention is blended, a pressure-sensitive adhesive having a good balance between adhesive strength and adhesive strength can be obtained. Example 2 and Example 3 are more adhesive than Comparative Example 2 and Comparative Example 3 of the corresponding composition shown in Table 3, and are transparent and have high holding power at high temperatures. You can see that it has.

[0084] As can be seen from the results in Table 4, the block copolymer used in the pressure-sensitive adhesive of the present invention is compatible with many types of tackifying resins. In the case of the present invention, it is also possible to blend a petroleum rosin-based tackifier resin that has been difficult to formulate due to its low compatibility with the base polymer of an acrylic adhesive. This means that it is possible to design a pressure-sensitive adhesive formulation by selecting a suitable one from many types of tackifying resins. In addition to adhesive properties such as adhesive strength and cohesive strength, Facilitates response to various plant requirements ranging from odor and raw material costs.

[0085] Further, as can be seen from the results in Table 6, the pressure-sensitive adhesive composition of the present invention has high cohesive strength even under high humidity, and the transparency is impaired even under conditions immersed in water. This indicates that the water resistance is excellent.

Industrial applicability

[0086] As described above, the pressure-sensitive adhesive composition of the present invention contains a specific acrylic block copolymer and has excellent weather resistance, heat resistance, water resistance, and transparency. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a pressure-sensitive adhesive and a pressure-sensitive adhesive product that can have excellent pressure-sensitive adhesive performance over a long period of time even under an environment exposed to ultraviolet rays or under high temperature and high humidity usage conditions. In addition, the specific acrylic block copolymer used in the present invention has a form excellent in handling properties such as pellets. It is possible provided in state, _c which can increase the production efficiency of the adhesive

Claims

The scope of the claims

[1] At least one polymer block (A) composed of methacrylic acid alkyl ester units (A) 23 to 98% by mass and at least one acrylic acid alkyl ester unit force having 6 to 18 carbon atoms in the alkyl group Polymer block (B) having 77 to 2% by mass, weight average molecular weight force 5,000 to 1,000,000, molecular weight force S1.0 to 1.5 100 parts by weight of copolymer; and

A tackifier resin having a solubility parameter value of 8.0 or more and 11.0 or less 1 part by mass or more and 400 parts by mass or less;

A pressure-sensitive adhesive composition containing

[2] The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition is produced by ion polymerization in the presence of an organoaluminum compound.

[3] The pressure-sensitive adhesive composition according to claim 1, wherein the solubility parameter value of the tackifying resin is 8.0 or more and 10.4 or less.

[4] The pressure-sensitive adhesive composition according to claim 1, wherein the tackifying resin is petroleum resin.

[5] An adhesive product having an adhesive layer comprising the adhesive composition according to claim 1.