JPH05263064A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a composition prevented from suffering the lowering in pressure-sensitive adhesive properties and the staining of an adherend with the additives by adding an oil-absorbing crosslinked polymer prepared by polymerizing a monomer of a solubility parameter of 9 or below in the presence of a crosslinking monomer to a pressure-sensitive adhesive. CONSTITUTION:This composition is one containing 0.1-50wt.%, based on the composition, oil-absorbing crosslinked polymer obtained by polymerizing a monomer component comprising 96-99.999wt.% monomer (A) containing one polymerizable unsaturation in the molecule, mainly consisting of a monomer of a solubility parameter of 9 or below and 0.01-4wt.% crosslinking monomer (B) containing at least two polymerizable unsaturations in the molecule. Examples of monomer A include methyl (meth)acrylate and phenyl (meth) acrylate. Examples of monomer B include ethylene glycol di(meth)acrylate and neopentyl glycol di(meth) acrylate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive composition. More specifically, various additives such as a resin modifier contained in an adherend such as a resin product or a support such as an adhesive tape or various additives such as a plasticizer or a release agent contained in an undercoat layer are adhered or It may be separated from the support or the undercoat layer with time to transfer to the pressure-sensitive adhesive to reduce the adhesive strength of the pressure-sensitive adhesive, or various additives blended in the pressure-sensitive adhesive itself may be separated with time to adhere the pressure-sensitive adhesive. The present invention relates to a pressure-sensitive adhesive composition that does not deteriorate performance such as force and does not cause additives to migrate to the surface of a pressure-sensitive adhesive tape or the like to contaminate an adherend.

[0002]

2. Description of the Related Art Polymer compounds such as plastics and elastomers, which are conventionally used as a support such as an adhesive tape or an adhesive base material, a so-called resin has resin properties (flexibility, elasticity, brittleness, handleability, etc.), resin Performance (adhesiveness, stability,
Durability, heat resistance, etc.) and processability (coatability, kneadability, etc.)
Various additives are blended for the purpose of modifying the. Further, various additives are also mixed in a resin product as an adherend which is adhered by an adhesive.

Examples of such additives include plasticizers, softeners, softening aids, flame retardants, smoke suppressants, antistatic agents, stabilizers, antiaging agents, copper damage inhibitors, and metal deactivators. Agents, antioxidants, antiozonants, ultraviolet absorbers, light stabilizers, mastication accelerators, tackifiers, lubricants, slip agents, internal release agents, colorants, antifouling agents, antiadhesive agents, Antifogging agent, preservative,
Antifungal agent, heat retaining agent, foaming agent, anti-scorch agent, anti-vibration agent,
Impact resistance improver, solvent, termite repellent, repellent, fragrance, surface treatment, wetting agent, surfactant, emulsifier, destabilizing agent, slow coagulant, defoaming agent, defoaming agent, freezing Inhibitors, freeze-thaw stabilizers, creaming agents, dispersants, thickeners, coagulants, heat sensitive agents, foaming agents, bubble stabilizers, film-forming aids and modifiers for sealing gaskets have been used. .. Further, these additives are rarely used singly, and most of them are used in combination.

However, when an additive having a poor compatibility with the resin for the support, the pressure-sensitive adhesive or the adherend is used, or an additive having a good compatibility is used in excess of the amount solubilized in the resin. However, there is a problem that the additive separated from the support or the adherend migrates to the pressure-sensitive adhesive to impair the performance of the pressure-sensitive adhesive.
Further, the additive may be separated from the adhesive over time to reduce the adhesive strength of the adhesive, or the additive separated from the adhesive may migrate to the surface of an adhesive product such as an adhesive tape to contaminate an adherend. There was also a problem due to the bleeding phenomenon. As a method for solving the problems associated with the segregation of the additive with time and the bleeding phenomenon, it is known to reduce the additive amount of the additive or add wax. However, these methods have a drawback that the performance such as the adhesive strength of the pressure-sensitive adhesive is deteriorated. Further, in an adhesive product such as an adhesive tape, a method of providing a special undercoat layer for preventing the additive from the support from migrating to the adhesive layer between the support and the adhesive layer (JP-A-1-121338). ). However, this method requires an undercoating step and is industrially disadvantageous.

[0005]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems associated with the bleeding phenomenon and segregation of various additives which have been conventionally compounded in an adhesive, a support or an adherend with time. ..

That is, the object of the present invention is to provide various additives such as a plasticizer and a release agent, which are blended in the adherend, the support or the pressure sensitive adhesive itself, with time from the adherend, the support or the pressure sensitive adhesive. A pressure-sensitive adhesive composition that does not impair the performance such as pressure-sensitive adhesive strength of the pressure-sensitive adhesive and does not cause the additive separated from the pressure-sensitive adhesive to migrate to the surface of pressure-sensitive adhesive products such as pressure-sensitive adhesive tape and contaminate the adherend. Is to provide.

[0007]

Means for Solving the Problems The present inventors have found that the above object can be easily achieved industrially by incorporating a specific oil-absorbing crosslinked polymer in a pressure-sensitive adhesive composition, and It came to completion.

That is, according to the present invention, the monomer (A) 96 to 9 having one polymerizable unsaturated group in the molecule whose main component is a monomer having a solubility parameter (SP value) of 9 or less.
9.999% by weight and 0.001 to 4 crosslinkable monomers (B) having at least two polymerizable unsaturated groups in the molecule
% By weight (however, the sum of monomers (A) and (B) is 10
The oil-absorptive crosslinked polymer (I) obtained by polymerizing a monomer component consisting of
The present invention relates to a pressure-sensitive adhesive composition which is contained in a weight percentage.

[0009]

The solubility parameter (SP value) is generally used as a measure of the polarity of a compound, and in the present invention, the value derived by substituting the Hoy cohesive energy constant into the Small calculation formula is applied, The unit is (cal /
represented by cm ^{3) 1/2.}

The monomer constituting the main component of the monomer (A) used in the present invention is a monomer having a solubility parameter (SP value) of 9 or less and having one polymerizable unsaturated group in the molecule. It is the body. When a monomer having a solubility parameter (SP value) of more than 9 is used as the main component of the monomer (A), a cross-linked polymer having a high bleed preventing effect cannot be obtained, and the additive may be added to the adhesive composition over time. It is not preferable because it is impossible to prevent the adhesive strength from being lowered and the adherend from being contaminated by bleeding.

Examples of the monomer having a solubility parameter (SP value) of 9 or less and having one polymerizable unsaturated group in the molecule include, for example, methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth). Acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate,
Dodecyl (meth) acrylate, isobornyl (meth)
Acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, octylphenyl (meth)
Acrylate, nonylphenyl (meth) acrylate,
Unsaturated carboxylic acid esters such as dinonylphenyl (meth) acrylate, cyclohexyl (meth) acrylate, menthyl (meth) acrylate, dibutyl maleate, didodecyl maleate, dodecyl crotonate and didodecyl itaconate; (di) butyl ( (Meth) acrylamide, (di) dodecyl (meth) acrylamide,
(Meth) acrylamide having a hydrocarbon group such as (di) stearyl (meth) acrylamide, (di) butylphenyl (meth) acrylamide, (di) octylphenyl (meth) acrylamide; 1-hexene, 1-octene, isooctene, Α-Olefins such as 1-nonene, 1-decene, 1-dodecene; alicyclic vinyl compounds such as vinylcyclohexane; allyl ethers having a hydrocarbon group such as dodecyl allyl ether; vinyl caproate, vinyl laurate, palmitic acid Vinyl ester having a hydrocarbon group such as vinyl and vinyl stearate;
Vinyl ether having a hydrocarbon group such as butyl vinyl ether and dodecyl vinyl ether; aromatic vinyl compounds such as styrene, t-butyl styrene and octyl styrene, and the like, and one or more of these monomers can be used. You can

Among these, as the monomer (A) which gives the pressure-sensitive adhesive composition having further excellent performance, there is at least one aliphatic hydrocarbon group having 3 to 30 carbon atoms and alkyl ( At least one unsaturated compound (a) selected from the group consisting of (meth) acrylate, alkylaryl (meth) acrylate, alkyl (meth) acrylamide, alkylaryl (meth) acrylamide, fatty acid vinyl ester, alkylstyrene and α-olefin Those containing as a main component are preferable.

Such solubility parameter (SP value)
Is 9 or less, the amount used in the monomer (A) is
The proportion is 50% by weight or more, more preferably 70% by weight or more, based on the total amount of the monomer (A). When the amount of the monomer having a solubility parameter (SP value) of 9 or less in the monomer (A) is less than 50% by weight, a crosslinked polymer having a high bleeding-preventing effect cannot be obtained, and the additive is a pressure-sensitive adhesive composition. It is not preferable because it bleeds with time from the object and causes a decrease in adhesive strength and contamination of the adherend.

Therefore, in the present invention, 50 monomers having a solubility parameter (SP value) of 9 or less are contained in the monomer (A).
It is necessary to contain at least 50% by weight, but the solubility parameter (SP value) is 50% by weight or less in the monomer (A).
May contain more than 9 monomers. Examples of such a monomer include (meth) acrylic acid, acrylonitrile, maleic anhydride, fumaric acid, hydroxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and methoxypolyethylene glycol (meth) acrylate. be able to.

Examples of the crosslinkable monomer (B) used in the present invention include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate, polyethylene glycol-polypropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, N, N'-methylenebis (meth) acrylamide, N, N'-propylenebis (meth) acrylamide, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate, tetramethylolmethane tetra (meth) acrylate, polyfunctional (meth) obtained by esterification of (meth) acrylic acid with an alkylene oxide adduct of polyhydric alcohol (eg glycerin, trimethylolpropane or tetramethylolmethane) Examples thereof include acrylate and divinylbenzene, and one or more of these crosslinkable monomers can be used.

The proportions of the monomer (A) and the crosslinkable monomer (B) in the monomer component used for producing the oil-absorbent crosslinked polymer (I) are as follows. The amount of the monomer (A) is 96 to 99.9 based on the total amount of the crosslinkable monomer (B).
99% by weight, the crosslinkable monomer (B) is 0.001-
It is in the range of 4% by weight.

When the amount of the monomer (A) is less than 96% by weight or the amount of the crosslinkable monomer (B) exceeds 4% by weight, the crosslink density of the obtained crosslinked polymer becomes too high and the crosslinked polymer is As a result of lowering the bleed prevention effect, the additive bleeds with time from the pressure-sensitive adhesive composition, causing a decrease in the adhesive strength and contamination of the adherend, which is not preferable. Further, the monomer (A) is 9
If it exceeds 9.999% by weight, the compatibility of the resulting cross-linked polymer with the base resin for pressure-sensitive adhesives and additives will increase, but the cohesive strength and pressure-sensitive adhesive balance of the pressure-sensitive adhesive will be impaired and the bleeding of the additive will be impaired. It is not preferable because the prevention effect becomes insufficient.

To produce the oil-absorbing crosslinked polymer (I),
The monomer component may be copolymerized using a polymerization initiator. The copolymerization can be carried out by a known method such as suspension polymerization, bulk polymerization or emulsion polymerization.

In the suspension polymerization, for example, an emulsifier having a high HLB value and a protective colloid agent such as polyvinyl alcohol, hydroxyethyl cellulose and gelatin are used to suspend the monomer component in water to prepare an oil-soluble polymerization initiator. The polymerization may be carried out in the presence of Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, 2,2′-azobisisobutyronitrile, and 2,2′-azobisdimethylvaleronitrile. The azo compound can be used, and the polymerization temperature is preferably in the range of 0 to 150 ° C. The obtained cross-linked resin suspension having a particle size of about 10 to 1000 μm is filtered and dried to obtain the desired crosslinked polymer (I).

In the bulk polymerization, for example, the monomer component is poured into a mold in the presence of the above-mentioned polymerization initiator, and the polymerization is carried out under the condition of 0 to 150 ° C. to obtain the desired crosslinked polymer (I). Be done.

In emulsion polymerization, for example, a monomer component is suspended in water using an anionic or nonionic emulsifier or a composite emulsifier thereof, and a persulfate such as ammonium persulfate or potassium persulfate or a water-soluble azo compound is suspended. It is possible to use it as a polymerization initiator, and use a reducing agent, a pH adjuster, an antioxidant, an antistatic agent, etc. together, if necessary, and carry out the polymerization under the condition of 0 to 150 ° C. The desired crosslinked polymer (I) is obtained.

The pressure-sensitive adhesive composition of the present invention contains the above oil-absorbing crosslinked polymer (I) in the composition in an amount of 0.1 to 50% by weight, preferably 0.5 to 25% by weight. Is. When the content of the cross-linked polymer (I) is less than 0.1% by weight, it is not preferable because it is impossible to prevent segregation and bleeding phenomenon of the additive compounded in the pressure-sensitive adhesive composition with time. Further, the content of the crosslinked polymer (I) is 50% by weight.
If the amount exceeds the above range, the balance between the cohesive force and the adhesive force of the pressure-sensitive adhesive composition will be impaired and uniform mixing will be difficult during preparation of the pressure-sensitive adhesive, which is not preferable.

As long as the above-mentioned oil-absorptive crosslinked polymer (I) is contained in the pressure-sensitive adhesive composition of the present invention, conventionally known pressure-sensitive adhesive formulations can be adopted. Generally, a pressure-sensitive adhesive composition is composed by adding a tackifier, a plasticizer or a softening agent, a cross-linking agent, and various other additives to a base resin as necessary, and the formulation is a pressure-sensitive adhesive. It can be appropriately selected depending on the types of the adherend and the support and the application conditions of the pressure-sensitive adhesive.

Examples of the base resin for adhesives include natural rubber, polychloroprene, styrene-butadiene block copolymers, styrene-isoprene block copolymers, styrene-olefin block copolymers, vinyl acetate-ethylene copolymers. , Polyisobutylene, acrylic acid ester-based copolymers, polyvinyl ether, and the like. The base resin is generally 10 to 90% by weight in the adhesive composition.
Used in proportion.

As the tackifier, for example, coumarone / indene resin, coumarone resin / coumarone resin / naphthenic oil / phenol resin / rosin mixture, etc .; p-third
-Phenol / terpene resin system such as butylphenol / acetylene resin, phenol / formaldehyde resin, tempenphenol resin, polyterpene resin, xylene / formaldehyde resin; Quinton A100, Quinton B170, Quinton D100, Quinton M1
00, Quinton U185, Wingtack95, W
ingtackExtra, Wingtak86, W
Synthetic polyterpene resin system such as intack10; Nisseki Neopolymer 80, Nisseki Neopolymer 120, Nisseki Neopolymer 140, Nisseki Neopolymer 160, Nisseki Neopolymer E-100, Nisseki Neopolymer T, Nisseki Neopolymer Aromatic hydrocarbon resin system such as S; Escorez
1102, Escorez 1202U, Escorez
1205, Escorez 1271, Tucky Roll 10
00, Takkiroll 5000, Piccopale, and other aliphatic hydrocarbon resin systems; Alcon P-90, Alcon P-100, Alcon P-115, Highlets G-10
Aliphatic cyclic hydrocarbon resin system such as 0X and Hiletz T-100X; Aliphatic / alicyclic petroleum resin system such as Escorez1401; Escorez2101, Escore
Aliphatic aromatic petroleum resin systems such as z2203; Escor
unsaturated hydrocarbon polymer systems such as ez8030; Esco
hydrogenated hydrocarbon resin system such as rez5380, Escorez5300; YS resin 75, Piccotac
Hydrocarbon-based tackifying resin system such as resins A; Petroleum-based hydrocarbon resin system such as polybutene, atactic polypropylene, liquid polybutadiene, cis-1,4-polyisoprene rubber, hydrogenated polyisoprene rubber, Claprene LIR-290; rosin Pentaerythritol ester, rosin glycerol ester, hydrogenated rosin, advanced rosin methyl ester, hydrogenated rosin methyl ester, hydrogenated rosin triethylene glycol ester, hydrogenated rosin pentaerythritol ester, hydrogenated rosin ester, Examples include rosin derivative resins such as high melting point ester resins, polymerized rosins, zinc resinates, and cured rosins; turpentine tackifiers, co-condensates of synthetic resins and phthalates, and nonionic activators. Can be used among the compound (s). The tackifier is generally used in the adhesive composition in an amount of 70% by weight or less.

Examples of the plasticizers and softeners include dimethyl phthalate, dibutyl phthalate, diethyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di n-octyl phthalate, dicapryl phthalate, dinonyl phthalate, diisononyl. Phthalate, diisodecyl phthalate, diundecyl phthalate, dilauryl phthalate,
Ditridecyl phthalate, diisobutyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate,
Dimethoxyethyl phthalate, dibutoxyethyl phthalate, dimethyl cyclohexyl phthalate, octyl decyl phthalate, octyl benzyl phthalate, n-hexyl.n-decyl phthalate, n-octyl.n-
Phthalic acid ester derivatives such as decyl phthalate; phthalic acid isomers such as dimethyl isophthalate, dioctyl isophthalate, di-2-ethylhexyl terephthalate; di2-ethylhexyl tetrahydrophthalate,
Tetrahydrophthalic acid derivatives such as di-n-octyl tetrahydrophthalate; tricresyl phosphate, trioctyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, trichloroethyl phosphate, bisphenol A diphenyl phosphate, bisphenol A dixylenyl phosphate. Phosphoric acid ester derivatives such as;
Dimethyl adipate, dibutyl adipate, diisodecyl adipate, diisobutyl adipate, diisononyl adipate, di2-ethylhexyl adipate, di n-
Adipic acid derivatives such as octyl adipate, didecyl adipate, n-octyl n-decyl adipate, n-heptyl n-nonyl adipate, benzyl octyl adipate, dibutyl diglycol adipate; di n-butyl sebacate, di n-octyl sebacate, Diisooctyl sebacate, di2-ethylhexyl sebacate,
Sebacic acid derivatives such as butylbenzyl sebacate; Azelaic acid derivatives such as di-2-ethylhexyl azelate, di-n-hexyl azelate, dimethyl azelate, dibenzyl azelate, dibutoxyethyl azelate, diisooctyl azelate; Triethyl citrate, acetyl triethyl citrate, tributyl citrate,
Citric acid type such as acetyl tributyl citrate, acetyl trioctyl citrate; epoxy type such as epoxidized soybean oil, butyl epoxy stearate, octyl epoxy stearate, dioctyl epoxy hexahydrophthalate; polypropylene adipate, polypropylene sebacate, etc. Polyester type; chlorinated paraffin,
Chlorinated system such as chlorinated fatty acid ester; glycolic acid system such as methylphthalylethyl glycolate, ethylphthalylethyl glycolate, butylphthalylbutyl glycolate; tri-2-ethylhexyl trimellitate, tri n-octyl n- Trimellitic acid type such as decyl trimellitate; Ricinoleic acid type such as methyl acetylricinoleate and butylacetylricinoleate; Butyl oleate; Paraffin type process oil, aromatic process oil, special process oil, ethylene and α-olefin Oligomer, paraffin wax, liquid paraffin,
Mineral oils such as white oil, petroleum dam, petroleum sulfonate, giussonite, petroleum asphalt, petroleum resin; castor oil, cottonseed oil, rapeseed oil, soybean oil, balm oil, coconut oil, peanut oil, wax, rosin, pine oil, Vegetable oil system such as dipentene, pine tar-containing softening agent, tall oil, refined tall oil; sub system such as black sub, white sub, candy sub; ricinoleic acid, palmitic acid, mistyric acid, barium stearate, calcium stearate, stearic acid Examples thereof include fatty acids such as magnesium and zinc stearate and fatty acid salt-based compounds, and one or more of these compounds can be used. These plasticizers and softeners are generally used in the adhesive composition in an amount of 40% by weight or less.

The cross-linking agent is for increasing the cohesive force of the pressure-sensitive adhesive composition, and is a compound having two or more functional groups capable of reacting with the functional groups contained in the base resin, such as tolylene diisocyanate or isophorone diisocyanate. And other polyisocyanate compounds, epoxy resins, melanin resins and the like.

The pressure-sensitive adhesive composition of the present invention includes, for example, fillers such as carbon black and silica, internal release agents such as perfluoroalkyl betaine and ether phosphates,
Flame retardant, smoke suppressor, antistatic agent, stabilizer, antiaging agent, antioxidant, antiozonant, ultraviolet absorber, light stabilizer, lubricant, colorant, preservative, antifungal agent, Thickener,
Various additives such as a wetting agent, a dispersant, a surfactant, a solvent, and a film-forming aid can be added.

The pressure-sensitive adhesive composition of the present invention contains the above oil-absorptive crosslinked polymer (I) in the above-mentioned mixing ratio, but it is preferable that the components constituting the composition are uniformly mixed. There are no particular restrictions on the method for incorporating the oil-absorbing crosslinked polymer (I) into the pressure-sensitive adhesive composition, and for example, a base resin for pressure-sensitive adhesive or various additives for pressure-sensitive adhesive may be used in various types such as ribbon blenders, Banbury mixers, and Haysyl mixers. The oil-absorptive crosslinked polymer (I) may be added and mixed at the time of mixing using a blender or a mixer. It is also possible to mix the additive with the oil-absorbing crosslinked polymer (I) in advance, swell the oil-absorbing crosslinked polymer (I) with the additive, and then mix with the base resin for use. Furthermore, the rate of absorption of the additive into the oil-absorbing crosslinked polymer (I) can be increased by heating the mixture of the additive and the oil-absorbing crosslinked polymer (I) within a range where the additive does not volatilize or deteriorate. ..

The pressure-sensitive adhesive composition of the present invention can be applied to a support such as paper, cloth, metal foil, plastic film such as polyvinyl chloride or polyester, and dried if necessary to produce a pressure-sensitive adhesive tape or label. It is possible to manufacture adhesive products such as.

The pressure-sensitive adhesive product obtained from the pressure-sensitive adhesive composition of the present invention may be applied by being attached to an adherend of various materials such as metal, glass, paper, cloth, wood, stone, rubber and plastic. In particular, the adhesive force can be stably maintained for a long period of time with respect to the adherend made of rubber or plastic. Examples of rubber or plastic applied as an adherend include polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polystyrene, (meth) acrylic resin, polyvinyl alcohol, polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polycarbonate, Homopolymers or copolymers of polyamide, acetyl cellulose, fluororesin, phenol resin, urea resin, melanin resin, polyester resin, allyl resin, silicone resin, epoxy resin, AS resin, ABS resin, synthetic rubber, natural rubber or the like. Mention may be made of mixtures of these resins.

[0032]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, parts and% are based on weight unless otherwise specified.

[0033]

[Reference Example 1] 3 parts of gelatin and 3 parts of water were placed in a 500 ml flask equipped with a thermometer, a stirrer, a gas inlet tube and a reflux condenser.
It was dissolved in 00 parts and charged, and the inside of the flask was replaced with nitrogen while stirring, and the mixture was heated to 40 ° C. under a nitrogen stream. Then, nonylphenyl acrylate (SP value:
8.3) 99.794 parts, 0.206 parts of 1,6-hexanediol diacrylate as a crosslinkable monomer (B), and benzoyl peroxide 0.5 as a polymerization initiator.
Part solution at once at 400 rpm
The mixture was vigorously stirred under the conditions of.

Then, the temperature inside the flask was raised to 80 ° C. and maintained at the same temperature for 2 hours to carry out the polymerization reaction. Then, the temperature inside the flask was further raised to 90 ° C. and maintained for 2 hours to complete the polymerization. Let After completion of the polymerization, the granular product was filtered off, washed with water and dried at 60 ° C. to give a particle size of 10
A crosslinked polymer (1) having a size of 0 to 1000 μm was obtained.

[0035]

Reference Example 2 In Reference Example 1, 57.772 parts of dodecyl acrylate (SP value: 7.9) and N, N-dioctyl acrylamide (SP value: 8.) as the monomer (A).
2) 38.515 parts, polypropylene glycol dimethacrylate (molecular weight 400 as crosslinkable monomer (B)
0) A crosslinked polymer (2) having a particle size of 100 to 1000 μm was obtained by the same method as in Reference Example 1, except that 3.713 parts were used instead.

[0036]

Reference Example 3 Stearyl acrylate (SP value: 7.8) 99.855 as the monomer (A) in Reference Example 1
And a particle size of 100 to 1000 μm by the same method as in Reference Example 1 except that 0.145 parts of 1,4 butanediol diacrylate was used as the crosslinkable monomer (B).
A cross-linked polymer (3) was obtained.

[0037]

Reference Example 4 Isobornyl acrylate (SP value: 8.4) 99.796 as the monomer (A) in Reference Example 1
Part, a crosslinked polymer (4) having a particle size of 100 to 1000 μm was obtained by the same method as in Reference Example 1, except that 0.204 part of ethylene glycol diacrylate was used as the crosslinkable monomer (B) instead. It was

[0038]

[Reference Example 5] A glass casting polymerization mold (a tray shape having a size of 5 x 5 x 1 cm) equipped with a thermometer and a gas introduction tube,
Dodecyl acrylate as monomer (A) (SP value:
7.9) A mixed solution consisting of 99.823 parts, 0.177 parts of ethylene glycol diacrylate as a crosslinkable monomer (B), and 0.1 parts of 2,2′-azobisdimethylvaleronitrile as a polymerization initiator. Inject and under a nitrogen stream 60
Polymerization reaction was carried out by heating at 0 ° C for 2 hours, then heated to 80 ° C and maintained for 2 hours to complete the polymerization. After cooling, the gel-like material was peeled from the mold to obtain a crosslinked polymer (5).

[0039]

Reference Example 6 Hexadecyl methacrylate (SP value: 7.8) 49.93 as the monomer (A) in Example 5.
0 part and N-octyl methacrylamide (SP value:
8.6) except that 49.930 parts and 0.140 parts of divinylbenzene as the crosslinkable monomer (B) are used instead.
A crosslinked polymer (6) was obtained in the same manner as in Reference Example 5.

[0040]

Reference Example 7 Cyclohexyl methacrylate (SP value: 8.3) 99.7 as the monomer (A) in Reference Example 5
A crosslinked polymer (7) was obtained in the same manner as in Reference Example 5 except that 71 parts and 0.229 parts of N, N ′ methylenebisacrylamide as the crosslinkable monomer (B) were used instead.

[0041]

Reference Example 8 Isobornyl acrylate (SP value: 8.4) 99.796 as the monomer (A) in Reference Example 5
A crosslinked polymer (8) was obtained in the same manner as in Reference Example 5, except that 0.204 part of ethylene glycol diacrylate was used as the crosslinkable monomer (B).

[0042]

[Reference Example 9] In a 500 ml flask equipped with a thermometer, a stirrer, a gas introduction tube, two dropping funnels and a reflux condenser,
Charge 3 parts of polyoxyethylene glycol (degree of polymerization 17) monononylphenyl ether and 100 parts of water, and
The inside of the flask was replaced with nitrogen while stirring under the condition of 00 rpm, and the flask was heated to 70 ° C. under a nitrogen stream.

On the other hand, t-butylstyrene (SP value: 7.9) 54.881 parts and 1-decene (SP value: 7.0) 44.903 parts as the monomer (A), a crosslinkable monomer As the monomer (B), a monomer composed of 0.216 parts of divinylbenzene was added to polyoxyethylene glycol (degree of polymerization 17).
In an aqueous solution in which 150 parts of water was dissolved 3 parts of monononyl phenyl ether, a homogenizer was used for mixing for 10 minutes at 5000 rpm to prepare 253 parts of an aqueous dispersion of the monomer. Further, 1 part of sodium persulfate as a polymerization initiator was dissolved in 50 parts of water to prepare 51 parts of an aqueous solution of the polymerization initiator.

Each of the aqueous dispersion of the monomer and the aqueous solution of the polymerization initiator was placed in a separate dropping funnel, and 50 parts of the aqueous dispersion of the monomer and 5 parts of the aqueous solution of the polymerization initiator were placed in a flask. Polymerization was initiated. Then, while maintaining the inside of the flask under a nitrogen stream at 70 ° C., the remaining aqueous dispersion of the monomer was dropped over 120 minutes, and at the same time, the remaining aqueous sodium persulfate solution was dropped over 240 minutes. After completion of the dropping, the polymerization was further completed by maintaining at 70 ° C. for 120 minutes to obtain an aqueous dispersion of the crosslinked polymer (9). The average particle size of this crosslinked polymer (9) was 0.2 μm, and the content of the crosslinked polymer (9) in the obtained aqueous dispersion was 25.5%.

[0045]

Reference Example 10 Nonylphenyl acrylate (SP value: 8.3) 74.7 as the monomer (A) in Reference Example 9
93 parts and hydroxyethyl acrylate (SP value:
10.3) 24.931 parts and a crosslinked polymer (using the same method as in Reference Example 9 except that 0.276 parts of 1,6-hexanediol diacrylate was used as the crosslinkable monomer (B) instead. An aqueous dispersion of 10) was obtained. The average particle size of the crosslinked polymer (10) was 0.15 μm, and the content of the crosslinked polymer (10) in the obtained aqueous dispersion was 25.0%.
Met.

[0046]

Reference Example 11 In Reference Example 9, 99.811 parts of vinyl laurate (SP value: 7.9) as the monomer (A) and 0.187 parts of trimethylolpropane triacrylate as the crosslinkable monomer (B). An aqueous dispersion of the crosslinked polymer (11) was obtained by the same method as in Reference Example 9 except that was used instead. The average particle size of this crosslinked polymer (11) was 0.1.
5 μm, and the crosslinked polymer (1
The content of 1) was 25.0%.

[0047]

Reference Example 12 In Reference Example 9, t as the monomer (A)
-Butyl acrylate (SP value: 8.7) 98.991
Parts, except that 0.204 parts of polyethylene glycol diacrylate (molecular weight 500) was used instead as the crosslinkable monomer (B), an aqueous dispersion of the crosslinked polymer (12) was prepared in the same manner as in Reference Example 9. Obtained. This crosslinked polymer (12)
Had an average particle diameter of 0.2 μm, and the content of the crosslinked polymer (12) in the obtained aqueous dispersion was 25.0%.

[0048]

Comparative Reference Example 1 A method similar to Reference Example 1 except that the amount of nonylphenyl acrylate was changed to 94.541 parts and the amount of 1,6 hexanediol diacrylate was changed to 5.459 parts. Thus, a comparative crosslinked polymer (1) was obtained.

[0049]

Comparative Reference Example 2 Instead of 99.794 parts of nonylphenyl acrylate in Reference Example 1, 39.713 parts of nonylphenyl acrylate and acrylonitrile (SP
Value 9.2) 59.570 parts were used, and the comparative crosslinked polymer (2) was prepared in the same manner as in Reference Example 1 except that the amount of 1,6 hexanediol diacrylate was changed to 0.717 parts.
Got

[0050]

Comparative Reference Example 3 A comparative polymer (3) was obtained in the same manner as in Reference Example 1 except that 1,6 hexanediol diacrylate was not used in Reference Example 1.

[0051]

Comparative Reference Example 4 Comparative cross-linking weight was the same as in Reference Example 5, except that the amount of dodecyl acrylate was changed to 94.637 parts and the amount of ethylene glycol diacrylate was changed to 5.363 parts. United (4)
Got

[0052]

Comparative Reference Example 5 In Reference Example 5, dodecyl acrylate 3 was used instead of 99.823 parts of dodecyl acrylate.
9.854 parts and methacrylic acid (SP value: 10.1)
A comparative crosslinked polymer (5) was obtained in the same manner as in Reference Example 5 except that 59.780 parts were used and the amount of ethylene glycol diacrylate was changed to 0.366 part.

[0053]

Comparative Reference Example 6 A comparative polymer (6) was obtained in the same manner as in Reference Example 5, except that 1,6 hexanediol diacrylate was not used in Reference Example 5.

[0054]

Comparative Reference Example 7 Reference Example 11 except that the amount of vinyl laurate was changed to 94.619 parts and divinylbenzene 5.381 parts was used instead of 0.216 parts of trimethylolpropane triacrylate. An aqueous dispersion of the comparative crosslinked polymer (7) was obtained by the same method as described above.

[0055]

Comparative Reference Example 8 Instead of 99.811 parts of vinyl laurate in Reference Example 11, vinyl laurate 39.91 was used.
1 part and hydroxyethyl acrylate (SP value: 1
0.3) 59.867 parts were used, and divinylbenzene 0.2 was used instead of trimethylolpropane triacrylate.
An aqueous dispersion of comparative crosslinked polymer (8) was obtained in the same manner as in Reference Example 11 except that the amount was changed to 22 parts.

[0056]

Comparative Reference Example 9 An aqueous dispersion of Comparative Polymer (9) was obtained in the same manner as in Reference Example 11 except that trimethylolpropane triacrylate was not used in Reference Example 11.

[0057]

Example 1 Polyvinyl chloride 100 having a polymerization degree of 1000
Parts, 50 parts of di-2-ethylhexyl phthalate, 2 parts of epoxidized soybean oil, 2 parts of barium zinc stabilizer and 2 parts of polyethylene glycol monolaurate are mixed with a mixer, and a mixture of 0.05 mm with a biaxial kneading roll at 150 ° C. A support made of a soft polyvinyl chloride sheet having a thickness was formed.

On the other hand, each of the crosslinked polymers (1) to (8) obtained in Reference Examples 1 to 8 and the comparative polymers (1) to (6) obtained in Comparative Reference Examples 1 to 6 were pulverized. , 2 parts of the polymer powder, 50 parts of natural rubber powder, 50 parts of styrene-butadiene-styrene copolymer, di (2-ethylhexyl)
Phthalate 45 parts, coumarone indene resin 5 parts, carbon black 5 parts and 2.6 di-tertiary butyl-
2 parts of 4-methylphenol was added and kneaded in a mixer to obtain pressure-sensitive adhesive compositions (1) to (8) and comparative pressure-sensitive adhesive compositions (1) to (6) of the present invention.

Each of the obtained pressure-sensitive adhesive compositions (1) to (8) and comparative pressure-sensitive adhesive compositions (1) to (6) was dissolved in toluene, and then the support made of the soft polyvinyl chloride sheet was used. It was applied to one side of the body. Then, it was dried at 80 ° C. for 90 seconds to prepare pressure-sensitive adhesive tapes (1) to (8) and comparative pressure-sensitive adhesive tapes (1) to (6) having a pressure-sensitive adhesive layer having a thickness of 30 μm. For comparison, a blank pressure-sensitive adhesive tape was prepared using a pressure-sensitive adhesive composition containing no cross-linked polymer or comparative polymer.

Each of the adhesive tapes was placed on a filter paper, kept at 40 ° C., and after one week, the bleeding state of the plasticizer from the adhesive tape was observed from the back surface of the filter paper. The results are shown in Table 1.

[0061]

[Table 1]

[0062]

[Example 2] Aqueous dispersions of crosslinked polymers (9) to (12) obtained in Reference Examples 9 to 12 and Comparative Examples Reference Examples 7 to 9
12 parts of each of the aqueous dispersions of the comparative polymers (7) to (9) obtained in (1) was added to 60% of the acrylic emulsion adhesive.
Aqueous dispersion (PS-4517, manufactured by Nippon Shokubai Co., Ltd.) 20
When mixed with 0 part, the pressure-sensitive adhesive composition (9) to (12) of the present invention
And comparative pressure-sensitive adhesive compositions (7) to (9) were obtained.

Each of the obtained pressure-sensitive adhesive compositions (9) to (12) and comparative pressure-sensitive adhesive compositions (7) to (9) was applied to a polyester film support having a thickness of 25 μm and then 80 ° C.
The adhesive tapes (9) to (12) and the comparative adhesive tapes (7) to (9) each having an adhesive layer with a thickness of 30 μm were prepared by drying for 5 minutes. For comparison, a blank pressure-sensitive adhesive tape was prepared using a pressure-sensitive adhesive composition containing no cross-linked polymer or comparative polymer.

Using each of the obtained adhesive tapes,
The adhesive strength was measured by the following test method. The results are shown in Table 2.
It was shown to.

<Adhesive Strength Evaluation Method> JIS-Z-0237
Evaluation was made by measuring the 180-degree peel strength after 1 hour and 7 days from the application to a soft polyvinyl chloride plate according to the above. The tensile speed was 300 mm / min and the measurement temperature was 23 ° C.

[0066]

[Table 2]

[0067]

Example 3 A reaction vessel equipped with a thermometer, a stirrer, a nitrogen gas inlet tube and a reflux condenser tube was charged with 2 parts of hydroxylethyl acrylate, 3 parts of acrylic acid, 65 parts of 2-ethylhexyl acrylate, 30 parts of vinyl acetate and acetic acid. Ethyl 12
0 parts and 0.4 parts of benzoyl peroxide were added, and the mixture was kept at 80 ° C. for 4 hours to complete the polymerization. The ethyl acetate solution of the obtained polymer was cooled to give a nonvolatile content of 34.
An acrylic resin solution having 0% and a viscosity of 2000 cps was obtained.

Powder 40 obtained by pulverizing each of the crosslinked polymers (5) to (8) obtained in Reference Examples 5 to 8 into this solution
Parts and 0.5 part of Colonnade L (manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent were mixed to obtain pressure-sensitive adhesive compositions (13) to (16) of the present invention. Each of the obtained pressure-sensitive adhesive compositions (13) to (16) was applied to a polyester film having a thickness of 25 μm and dried at 80 ° C. for 2 minutes to obtain a pressure-sensitive adhesive tape (13) having a pressure-sensitive adhesive layer having a thickness of 30 μm. (1
6) was created. For comparison, a blank pressure-sensitive adhesive tape was prepared using a pressure-sensitive adhesive composition containing no cross-linked polymer.

Using each of the obtained adhesive tapes,
The adhesive strength was measured by the same adhesive strength evaluation method as that used in Example 2. The results are shown in Table 3.

[0070]

[Table 3]

[0071]

Example 4 20 parts of styrene-butadiene block copolymer (Califlex XX-65 manufactured by Shell Chemical Co., Ltd.),
Aliphatic petroleum resin as a tackifier (manufactured by Exxon Chemical,
50 parts of Escoletz 4401 and naphthenic oil as a softening agent (Shell Chemical, Shelf Rex 37
1 JY) 20 parts of powder obtained by pulverizing each of the crosslinked polymers (1) to (4) obtained in Reference Examples 1 to 4 was kneaded with a heating roll to obtain a film having a thickness of 2 mm of the present invention. Tape-shaped pressure-sensitive adhesive composition (hereinafter referred to as pressure-sensitive adhesive tapes (17) to (20)
I got). For comparison, a blank pressure-sensitive adhesive tape was prepared using a pressure-sensitive adhesive composition containing no cross-linked polymer.

Each of the obtained adhesive tapes was put on a filter paper and allowed to stand at 80 ° C. for 24 hours, and the bleeding state of the softening agent from the adhesive tape was observed from the back surface of the filter paper. The results are shown in Table 4.

[0073]

[Table 4]

[0074]

EFFECT OF THE INVENTION The pressure-sensitive adhesive composition of the present invention comprises a plasticizer or the like which is compounded in the pressure-sensitive adhesive composition itself or the support of a pressure-sensitive adhesive product such as a pressure-sensitive adhesive tape or the adherend to which the pressure-sensitive adhesive composition is applied. Since the segregation of various additives with time and the bleeding phenomenon are suppressed, the performance such as the adhesive strength is not deteriorated with time, and the adherend is not contaminated by the bleeding phenomenon.

Therefore, the pressure-sensitive adhesive composition of the present invention can maintain the initial pressure-sensitive adhesive force for a long period of time, and has a problem with soft polyvinyl chloride as a support, which has been a problem due to remarkable bleeding of conventional plasticizers. It is particularly effective when the tape or adherend is a plastic product.

Claims (2)

[Claims] 1. A monomer (A) having one polymerizable unsaturated group in a molecule containing a monomer having a solubility parameter (SP value) of 9 or less as a main component in an amount of 96 to 99.999% by weight, and 0.001 to 4% by weight of a crosslinkable monomer (B) having at least two polymerizable unsaturated groups in the molecule (however, the total amount of the monomers (A) and (B) is 100% by weight). A pressure-sensitive adhesive composition comprising an oil-absorptive crosslinked polymer (I) obtained by polymerizing the monomer component consisting of 0.1 to 50% by weight in the composition. 2. The monomer (A) has at least one aliphatic hydrocarbon group having 3 to 30 carbon atoms and is alkyl (meth) acrylate, alkylaryl (meth) acrylate, alkyl (meth) acrylamide. , Alkylaryl (meth) acrylamide, fatty acid vinyl ester,
The pressure-sensitive adhesive composition according to claim 1, which comprises at least one unsaturated compound (a) selected from the group consisting of alkylstyrene and α-olefin as a main component.