JPS63210182A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To form a pressure-sensitive adhesive composition having a feature of changing from being tacky to being non-tacky through curing in a short time by actinic radiation, by mixing an acrylic copolymer solution, a photo- setting monomer, a photopolymerization initiator, and an organic polyisocyanate. CONSTITUTION:This photo-setting pressure-sensitive adhesive composition is prepared by mixing an acrylic copolymer solution (A), a photo-setting monomer (B), a photopolymerization initiator (C), and an organic polyisocyanate (D). On a solids basis, the amount of A is about 30-90wt.% based on A + B, the amount of C is about 1-10wt.% based on B + C, and the amount of D is about 0.5-10wt.% based on A + D. An example of a photo-setting monomer B is a compound having photopolymerizable double bonds, such as acryloyl groups or methacryloyl groups, introduced into the side chain or at the end.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to pressure sensitive adhesive compositions. [Prior Art] Conventionally, in the electronic industry, for example, in the cutting process of IC silicone wafers, adhesives mainly consisting of acrylic polymers having adhesive properties have been used to fix the wafers. [Problems to be Solved by the Invention] However, this method has a problem in that it is difficult to remove the wafer from the adhesive because of its adhesive properties. [Means for Solving the Problems] The present inventors have intensively studied a pressure-sensitive adhesive composition that has the property of being able to change from adhesive to non-adhesive on a case-by-case basis, and
=Result 1 The present invention is reached, =. That is, the present invention provides a photocurable pressure-sensitive adhesive characterized by comprising an acrylic copolymer solution, a photocurable 7-mer <B), a photopolymerization initiator (C), and an organic polyisocyanate (D). It is a composition. In the acrylic copolymer solution (3), the acrylic copolymer is an alcohol having a carbon number of 1 to 14.
Examples include copolymers of [mu] [metacoacrylic acid ester IV (a) as a main component and a copolymerizable functional group-containing vinyl monomer (b). The galanu transition temperature of this copolymer (
Tg) is preferably in the range of -5 to -50°C. (meth)acrylic acid ester of alcohol having carbon number 1 to 14/L' (a) is (meth)acrylate (meth)acrylate from aliphatic alcohol having carbon number 1 to 14 (acrylate and/or methacrylate) The same description will be used hereafter.)
Acrylate, Ethyl/I/(meth)acrylate, Propyl(meth)acrylate, n-buty, IL/(meth)acrylate, i-buty/L/(meth)acrylate, t-buty A/(notafacrylate) , bench lv (methacrylate, octyl (meth)acrylate, 2
-Ethylhexy/L/(meth)acrylate, deci/L
/(meth)acrylate. Wouri/L/(meth)acrylate, Tridesi A/(meth)acrylate, Millimechi 7'L/(meth)acrylate V
-t-, from oxo or Ziegler process alcohols [from linear or branched natural or synthetic alcohols such as methacrylates (methacrylates;
(methacrylates from cycloalcohols, such as cyclohexy/L/(meth)acrylates; (methacrylates from aromatic alcohols, such as benzy/I/(meth)acrylates, etc.; and mixtures of two or more thereof. Among these, preferred are (meth) from aliphatic alcohols having 2 to 1 G carbon atoms.
Among the acrylates, particularly preferred are acrylates having 4 carbon atoms, acrylates having 8 carbon atoms, and mixtures thereof. Examples of the functional group-containing vinyl monomer (b) include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, crotonic acid, maleic acid, and itaconic acid. fumaric acid, etc.]; Vinyl monomers having a hydroxy μ group [hydroxyethy/1/(meth)acrylate, hydroxypropy/l/(methacrylate, etc.); Vinyl monomers having an amide group [(meth)acrylamide, etc.]; Epoxy group Examples include monoethylenically unsaturated monomers such as vinyl monomers having le (glycidi/I/(ivy) acrylate, etc.); vinyl monomers having a notyrol group (N-methyloμ acrylamide, etc.), and mixtures of two or more of these. Among these, preferred are vinyl monomers having a carboxyl group, vinyl monomers having a hydroxy μ group, and vinyl monomers having an amide group, and particularly preferred are acrylic acid, hydroxyethyl acrylate, and acrylamide. If necessary, some vinyl monomers without functional groups can also be used in combination. Examples of monomers include aromatic monomers [styrene, vinyl toluene, etc.]; monomers having an allyl group [aluminum acetate, etc.] ]: Nitrile group-containing polymers [(meth)acrylonitrile, etc.]; Halogen-containing vinyl or vinylidene yarn materials [vinyl chloride, vinylidene chloride, etc.]; Vinyl ester monomers
[Vinyl acetate, vinyl propionate, vinyl butyrate. Vinyl persate, etc.]; Vinyl ether monomers [vinyl μ ethyl ether μ, vinyl propy μ ether,
Mention may be made of non-reactive monoethylenically unsaturated monomers such as vinylisobutymu ether and mixtures of two or more thereof. Among these, vinyl ester monomers are preferred, and vinyl acetate and vinyl propionate are particularly preferred. In the acrylic copolymer, the content of (methacrylate ester Iv (a) is usually 20% or more, preferably 50% or more, particularly preferably 70% or more, based on the weight of the copolymer. ) If the content of acrylic acid ester μ is less than 20%, sufficient tackiness cannot be obtained and it is not sufficient as a pressure-sensitive adhesive. ), usually 30-99.5% (a), (b) based on the total weight of
) is 20-0.5%, preferably (a) is 90-99%
, (b) is 1 (1 to ls). If (b) is less than 0.5%, the pressure-sensitive adhesive with insufficient crosslinking will exhibit cohesive failure (adhesive residue) and will not be usable. If (b) exceeds 20%, the adhesive force will decrease.Solvents used in the acrylic copolymer solution include ester solvents (ethyl acetate, acetate butt), ether solvents ( dioxane, tetrahydrofuran, etc.), ketone solvents (cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, etc.), aromatic hydrocarbon solvents (toluene, xylene, etc.), aliphatic hydrocarbon solvents (cyclohexane, n-hexane, etc.), and these Examples include mixed solvents of two or more types. Among these, preferred are ethyl acetate IVl toluene,
These are cyclohexane and a mixed solvent of two or more thereof. The concentration of the acrylic copolymer solution is usually 20-90% by weight, preferably 30-60% by weight. The acrylic copolymer solution can be produced by known polymerization methods (solution polymerization, bulk polymerization). In the case of solution polymerization, the obtained product may be used as it is or may be diluted with a solvent. In the case of bulk polymerization, the solution is diluted and dissolved with a solvent. Preferred is a solution polymerization method. A radical initiator is usually used as a polymerization initiator during polymerization. Examples of such radical initiators include 1. Examples of oil-soluble initiators include peroxide initiators such as benzoyl peroxide and lauroyl peroxide, or azobinisobutyronitrile/I/l azobisdimethylvaleronitrile. and azo-based initiators such as azobiscyanovaleric acid. Examples of water-soluble initiators include sodium persulfate, potassium persulfate,
Examples of redox initiators include persulfates such as ammonium persulfate, hydrogen peroxide, or a combination of hydrogen peroxide and ferric chloride. The amount of polymerization initiator used is usually 0.1 to 1.0% of the total weight of the polymerization initiator.
Old to 5% by weight. The polymerization temperature must be selected depending on the decomposition temperature of the polymerization initiator, but is usually in the range of 0 to 200°C. The polymerization time is usually 1 to 24 hours. In order to adjust the degree of polymerization of the monocopolymer, a known chain transfer agent may be used, if necessary. Examples of such chain transfer agents include mercaptans such as dodecymu-norcaptan and n-butylno-mu-captan, and halogen compounds such as carbon tetrachloride. The molecular weight of the obtained copolymer is usually 5,000 to 1
,000,000. Considering that it is used as a component of Matko pressure-sensitive adhesive, the preferred molecular weight is 50,000.
500,000. A molecular weight of less than 5,000 US has insufficient adhesion and holding power, while a molecular weight of 1,0
If it exceeds 00,000, coating becomes difficult. Examples of the photocurable hexamer include compounds in which a photopolymerizable double bond is introduced into the side chain or terminal. Examples of the double bond include an acryloyl μ group and a methacryloyl group. Photocurable seven polymers can be classified into low molecular weight types and prepolymer types depending on their molecular weights. Low molecular weight types include polyhydric alcohol-μ (meth)acrylate, dihydric alcohol di(methacrylate (1,6-hexanethiol di(ivy)acrylate, neobenzi p-glyco7+, 'di(meth)acrylate, ) acrylate, ethylene glyco-μ di(meth)acrylate, etc.), octavalent μ alcohol tri-

〔Example〕

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. In the examples, parts mean parts by weight. Example 1 100 parts of acrylic acid butymuacrylic acid-acrylic acid hydroxyethyl copolymer (M ratio 94:4:l) (
Solid content 40%, solvent 1:1f of toene and ethyl acetate
fi amount ratio], triacrylate of trimethylo-μ propane propylene oxide addition polyol (average molecular weight =
'460) 20 parts, l-hydroxycyclohexyμpheniμketone 1 part, human-rich chlorofuropane (1 mol) and tolylene diisocyanate (8 mol/L/) reactant solution (solid content 75%, solvent A pressure-sensitive adhesive composition was obtained by mixing 2 parts of ethyl acetate/I/). This composition was applied to a 30 μm thick polyester film (P
ET) to a thickness of 25 μm (wet), cured at 30°C for 8 minutes, and then cured at room temperature for 7 days. After curing, ultraviolet rays were irradiated from the polyester film side for 20 seconds using a 30W high-pressure mercury lamp to form a photocurable adhesive layer. Example 2 100 parts of 2-ethylhexyl acrylate μm acrylic acid-hydroxyethyl acrylate μ copolymer (weight ratio 95:4:1) solution (solid content 40%, solvent: toene, ethyl acetate) :1 weight ratio)) A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, and a photocurable adhesive layer was formed. Example 8 Polypropylene glyco-μ diacrylate (average molecule 1
=810) A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except for 30 parts, and a photocurable adhesive layer was formed. Example 4 Example 11 In place of the trinothousandolpropane tolylene diisocyanate reactant in Example 1, 2 parts of a reactant (solid content loo type) of hexamethylene diisocyanate (8 mol) and water (1 mo A/) were used. Except for the above, a pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, and a photocurable adhesive layer was formed. Comparative Example 1 A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that polyisocyanate was not used and T was used. A photocurable adhesive layer was formed. Comparative Example 2 A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that the curable nitrate was not used, and a photocurable adhesive layer was formed.Comparative Example 8 Using an acrylic polymer solution Except that it was not. A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, and a photocurable adhesive layer was formed. Adhesives obtained in Examples 1 to 4 and Comparative Examples 1 to 8 The agent layer was laminated to a stainless steel plate (5υS 304), and a 130' peeling test was conducted according to JIS C-2107.The results are shown in Table 1.Table 1130' peeling test results (unit: g) /2.5cm)
[Effects of the Invention] The composition of the present invention, which is sticky, can be cured in a short time by irradiation with light and can be imparted with non-stick properties. Furthermore, since no heating or other operations are required to impart non-adhesive properties, there is also the advantage of less contamination and distortion of wafers, etc. Because it exhibits the above-mentioned effects, the composition of the present invention is particularly useful as a pressure-sensitive adhesive for a relticing film used in the cutting process of silicone wafers.

Claims (1)

[Claims] 1. A photocurable sensitive material comprising an acrylic copolymer solution (A), a photocurable monomer (B), a photopolymerization initiator (C), and an organic polyisocyanate (D). Pressure adhesive composition. 2. The composition according to claim 1, wherein the amount of (D) is 0.5 to 10% based on the total weight (solid content) of (A) and (D). 3. The composition according to claim 1 or 2, wherein the amount of (A) is 30 to 90% based on the total weight (solid content) of (A) and (B). 4. Claim 1 in which the amount of (C) is 1 to 10% based on the total weight (solid content equivalent) of (B) and (C)
The composition according to any one of Items 1 to 3.