JP2011021179A - Method for producing pressure-sensitive adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a composition (syrup) including polymers and monomers which is safe, is excellent in productivity, and a method for producing a pressure-sensitive adhesive sheet having superior pressure-sensitive adhesive performance, after UV-ray irradiation. <P>SOLUTION: The method for producing the pressure-sensitive adhesive sheet includes: a first process of, under agitation, heating or irradiating with active energy rays a composition comprising a compound (A) having one ethylenically unsaturated group, an oxetane compound (B) or the oxetane compound and a cation polymerizable compound (B) other than the oxetane and a radical polymerization initiator (C) to polymerize the component (A); a second process of adding a photocation polymerization initiator (D) to a reacted liquid obtained in the first process and mixing the reaction liquid and the photocation polymerization initiator; a third process of applying the mixture obtained in the second process onto a base material; and a fourth process of photo-irradiating the applied surface of the base material obtained in the third process to polymerize the component (B). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a pressure-sensitive adhesive sheet, and belongs to the technical field of pressure-sensitive adhesives and pressure-sensitive adhesive sheets.

  Conventionally, a composition containing a monomer and a polymer obtained by partial polymerization of the monomer is referred to as a syrup, and the pressure-sensitive adhesive sheet formed by ultraviolet irradiation or the like using this is excellent in heat resistance and water resistance. Since it is excellent in productivity, it is frequently used in various directions as various adhesive sheets. In addition, it is solvent-free and is preferably used from the viewpoints of global environmental conservation and working / working environment for handling it.

For example, a syrup is produced by partial polymerization of an acrylate monomer by heat or ultraviolet irradiation, and the resulting composition is applied to a support, then irradiated again with ultraviolet light, and further heated to 60 ° C. or higher. A manufacturing method has been proposed (Patent Document 1).
However, in this method, it is difficult to control partial polymerization, and in order to obtain a predetermined reaction rate, it takes time to sample and quantify the residual monomer amount by gas chromatography, or to obtain the nonvolatile content from the heated residue. . Moreover, although it is possible to estimate from the torque value of the stirring shaft attached to the polymerization reaction apparatus, there is a possibility that the torque value may change for each charged amount and each reaction kettle. Also, the reaction may run away and be dangerous.

As a similar technique, a pressure-sensitive adhesive sheet using a composition comprising an acrylic polymer, an epoxy compound and a photocationic polymerization initiator is known (Patent Document 2).
In Patent Document 2, more specifically, (a) alkyl (meth) acrylate, (b) other vinyl monomer, (c) epoxy compound, (d) photoradical polymerization initiator, and (e) photocationic polymerization initiation After preparing a composition containing an agent (step A), the composition is applied to a substrate and irradiated with ultraviolet rays that activate the component (d), and the components (a) and (b) are polymerized to be cured. A method for producing a pressure-sensitive adhesive sheet by preparing a pressure-sensitive adhesive sheet (Step B) and then irradiating ultraviolet rays that activate the component (e) and polymerizing the component (c) (Step C). Is disclosed.
However, in this production method, in order to obtain the viscosity required for the coating step in Step B, the viscosity of the composition becomes insufficient, and therefore a solid or high molecular weight epoxy compound must be used as the component (c). It may not be obtained or the amount of the epoxy compound used needs to be increased, and the adhesive performance may be inferior.

  On the other hand, as a technique similar to syrup, there is a method in which an ethylenically unsaturated monomer is polymerized in solution and then mixed with a cationic photopolymerizable monomer such as an epoxy compound. In this case, before ultraviolet irradiation, It is necessary to remove the solvent.

JP 2000-34453 A JP-A-9-279103

  The present inventor is able to produce a composition (syrup) containing a polymer and a monomer that is safe and excellent in productivity, and provides a method for producing a pressure-sensitive adhesive sheet having excellent adhesive performance after ultraviolet irradiation. As a result, we conducted an intensive study.

As a result of various studies to solve the above problems, the present inventor has found that a method for producing a syrup using a cationically polymerizable compound that essentially contains an ethylenically unsaturated group-containing compound and an oxetane compound is effective. As a result, the present invention was completed.
That is, this invention relates to the manufacturing method of the adhesive sheet including the following process.
First step: Compound (A) having one ethylenically unsaturated group (hereinafter referred to as component (A)), oxetane compound or oxetane compound and other cationic polymerization compound (B) [hereinafter referred to as (B) The composition containing the component] and the radical polymerization initiator (C) [hereinafter referred to as the component (C)] is heated with stirring or irradiated with active energy rays to polymerize the component (A).
-2nd process: Photocationic polymerization initiator (D) [henceforth (D) component] is added and mixed with the reaction liquid obtained at the 1st process.
-3rd process: The mixture obtained at the 2nd process is apply | coated to a base material.
-4th process: Light-irradiate the application surface of the base material obtained at the 3rd process, and polymerize the said (B) component.
Hereinafter, the present invention will be described in detail.
In the present specification, an acryloyl group or a methacryloyl group is represented as a (meth) acryloyl group, acrylamide or methacrylamide is represented as (meth) acrylamide, and acrylate or methacrylate is represented as (meth) acrylate.

According to the present invention, by using the component (A) as the initial polymer and the component (B) as a solvent in the initial polymerization, a syrup containing the partial polymer and the component (B) can be easily obtained. And it can be controlled accurately.
Moreover, the cured product obtained by irradiating the syrup with light is colorless and transparent, excellent in water resistance and heat resistance, and can be preferably used particularly as an adhesive.
Moreover, a pressure-sensitive adhesive sheet that is colorless and transparent, flexible, flexible, and tough can be produced by applying it to a substrate using syrup and irradiating it with light.

The present invention relates to a method for producing a pressure-sensitive adhesive sheet including the following steps.
First step: The composition containing the component (A), the component (B) and the component (C) is heated with stirring or irradiated with active energy rays to polymerize the component (A).
-2nd process: (D) component is added and mixed with the reaction liquid obtained at the 1st process.
-3rd process: The mixture obtained at the 2nd process is apply | coated to a base material.
-4th process: Light-irradiate the application surface of the base material obtained at the 3rd process, and polymerize the said (B) component.
Below, each process and the component to be used are demonstrated.

1. First Step The first step is a step of polymerizing the component (A) by heating the composition containing the components (A) to (C) with stirring or irradiating active energy rays.
First, the components (A) to (C) will be described.

1-1. Component (A) The component (A) is a compound having one ethylenically unsaturated group, and various compounds can be used as long as the compound has one ethylenically unsaturated group.
Examples of the ethylenically unsaturated group in component (A) include a (meth) acryloyl group and a vinyl group.

  In the present invention, as such a monomer species, for example, a compound having one (meth) acryloyl group [hereinafter referred to as monofunctional (meth) acrylate], (meth) acrylamide, styrene, vinyl carboxylate, (meth) Examples thereof include acrylic acid annealed esters, (meth) acrylic acid alkoxy, epoxy group-containing vinyl monomers, unsaturated carboxylic acids or partial ester compounds thereof and anhydrides thereof, and organic silicon group-containing vinyl compound monomers.

  Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and pentyl (meth) ) Alkyls such as acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate and dodecyl (meth) acrylate (Meth) acrylate; halogenated alkyl (meth) acrylate such as 2-chloroethyl (meth) acrylate; aromatic group-containing (meth) acrylate such as benzyl (meth) acrylate; methoxyethyl Alkoxyalkyl (meth) acrylates such as meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate; alicyclic such as cyclohexyl (meth) acrylate Examples include alkyl (meth) acrylates; dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate; and epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate.

  Examples of (meth) acrylamide include (meth) acrylamide, N-methylol (meth) acrylamide, and diacetone acrylamide.

  Examples of styrene include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; alkyl styrene; fluorostyrene, chlorostyrene Halogenated styrenes such as bromostyrene, dibromostyrene and chloromethylstyrene; nitrostyrene, acetylstyrene and methoxystyrene.

  Examples of vinyl carboxylate include vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl persate, vinyl laurate, vinyl stearate, vinyl benzoate, p -T-butyl vinyl benzoate, vinyl salicylate, etc. are mentioned. Mention may also be made of halides such as vinyl chlorohexanecarboxylate.

  As (A) component, since it is excellent in adhesive performance, it is preferable to use alkyl (meth) acrylate as monofunctional (meth) acrylate. Butyl acrylate, pentyl acrylate, hexyl acrylate, 2-ethylhexyl (meth) acrylate, octyl (Meth) acrylate and nonyl (meth) acrylate are more preferred.

As the component (A), the reaction of the oxetane compound or the oxetane compound as the component (B) with other cationic polymerization compounds, the introduction of a polar component for the purpose of improving adhesiveness, and when used in combination with a crosslinking agent described later A compound containing a functional group having reactivity with a crosslinking agent (hereinafter referred to as a functional group-containing unsaturated compound) can be used.
Examples of the functional group-containing unsaturated compound include a hydroxyl group-containing ethylenically unsaturated compound, a carboxyl group-containing ethylenically unsaturated compound, and an amino group-containing ethylenically unsaturated compound.

A hydroxyalkyl (meth) acrylate can be mentioned as a hydroxyl-containing ethylenically unsaturated compound.
Specific examples of the hydroxyalkyl (meth) acrylate include hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropityl (meth) acrylate, and the like.

Examples of the carboxyl group-containing ethylenically unsaturated compound include unsaturated carboxylic acids.
Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, bicyclo [2,2,1] hept-2-ene- Examples thereof include unsaturated carboxylic acids such as 5,6-dicarboxylic acid, and derivatives thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] hept- 2-ene-5,6-dicarboxylic acid anhydride and the like

  Examples of amino group-containing ethylenically unsaturated compounds include aminoethyl (meth) acrylate, propylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, aminopropyl (meth) acrylate, and (meth) acrylic acid. Alkyl ester derivatives of (meth) acrylic acid such as phenylaminoethyl, cyclohexylaminoethyl (meth) acrylate, vinylamine derivatives such as N-vinyldiethylamine and N-acetylvinylamine, allylamine, methacrylamine, N- Allylamine derivatives such as methylacrylamine, N, N-dimethylacrylamide, N, N-dimethylaminopropylacrylamide, acrylamide, acrylamide derivatives such as N-methylacrylamide, and aminostyrene such as p-aminostyrene S, 6-aminohexyl succinimide monomer having an amino group-containing ethylenic unsaturated bond such as 2-aminoethyl succinimide can be suitably used as appropriate.

  Among functional group-containing unsaturated compounds, a hydroxyl group-containing ethylenically unsaturated compound is preferable because it has not only a crosslinking component but also a reaction promoting effect when the component (B) is cured in the fourth step of the present invention.

In the polymerization of the component (A), it is not always necessary to form a crosslinked structure, but it can be formed by introducing a crosslinked structure as necessary.
In order to form such a crosslinked structure, a compound having two or more ethylenically unsaturated groups (hereinafter referred to as a polyfunctional monomer) can be suitably used.
Examples of the multifunctional monomer include ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, Neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethanetri Examples thereof include acrylate, 1,1,1-trishydroxymethylpropane triacrylate, N-methylol acrylate, and the like.
0.1-10 weight part is preferable with respect to 100 weight part of (A) component, and, as for a polyfunctional monomer, More preferably, it can use suitably suitably at 5 weight part or less.

Among these, the alkyl (meth) acrylate alone or the alkyl (meth) acrylate is relatively inexpensive as a raw material, has many monomer types, and is easy to control properties such as strength to a desired value. It is preferable to use a suitable combination of at least one of (meth) acrylates (hereinafter referred to as other (meth) acrylates) as appropriate.
Or when using combining alkyl (meth) acrylate and other (meth) acrylate, it uses suitably other (meth) acrylate in the range of 10-100 weight part with respect to 100 weight part of alkyl (meth) acrylate. It is preferable.
Examples of suitable component (A) other than (meth) acrylate include styrene, α-methylstyrene, chlorostyrene, methylstyrene, vinyltoluene, divinylbenzene, vinyltoluene, vinyl acetate, and diacrylic phthalate. It is done. These may be used alone or in combination of two or more.

  The most preferred combination is a combination of an alkyl (meth) acrylate and a hydroxyl group-containing (meth) acrylate. As a preferable ratio in this case, the hydroxyl group-containing (meth) acrylate is preferably 1 to 20 parts by weight, and more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the alkyl (meth) acrylate.

  Since the finally obtained cured film has excellent adhesive performance, the glass transition temperature (hereinafter referred to as Tg) of the polymer after polymerizing the component (A) in the first step is -10 ° C or lower. It is preferable to adjust the usage ratio.

1-2. Component (B) The component (B) is an oxetane compound or an oxetane compound and a cationic polymerization compound other than this.
The component (B) is a curable component in the fourth step, and also functions as a solvent for the component (A) in the first step.
Therefore, the following method has an advantage that the polymerization reaction can be allowed to proceed substantially in the absence of a solvent without adding a separate solvent, and a solvent removal step is unnecessary.
That is, there is a method in which the component (B) is mixed with the component (A) after solution polymerization. In this case, it is necessary to remove the solvent before light irradiation.
There is also a method of polymerizing the component (A) without using a solvent and then mixing the component (B), but the polymerization method is difficult to control the polymerization, and it is difficult to obtain the target polymer.

The component (B) essentially contains an oxetane compound.
Thereby, it is excellent in compatibility with the polymer of the said (A) component, and the polymer finally obtained does not have turbidity etc., and can make it excellent in transparency.
As the component (B), there are an embodiment in which an oxetane compound is used alone and an embodiment in which an oxetane compound and a cationically polymerizable compound other than this are used in combination.
(B) As a component, any of a monomer, an oligomer, and a prepolymer may be sufficient.

Specific examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 3-allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) methylbenzene, 4-fluoro- [1- ( 3-ethyl-3-oxetanylmethoxy) methyl] benzene, 4-methoxy- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, isobutoxymethyl ( 3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl-3 -Oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylethyl (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tetrabromophenoxyethyl (3 -Ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxyethyl (3- ethyl 3-Oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether , Pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, bornyl (3-ethyl-3-oxetanylmethyl) ether, bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, 3,7-bis (3-oxetanyl) -5-oxa-nonane, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, butanediol bis (3-ethyl-3-oxetanyl Methyl) ether, hexanediol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyl bis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether Tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO Modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxy) Tanylmethyl) ether, EO-modified bisphenol F bis (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) Ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether Dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether Ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether, carbonate bisoxetane, adipate bisoxetane, terephthalate bisoxetane, cyclohexanedicarboxylic acid bisoxetane, 3- (3-methyl-3-oxetanemethoxy) propyltriethoxysilane , 3- (3-ethyl-3-oxetanemethoxy) propyltrimethoxysilane and the like.
Besides these, oxetane silicones described in JP-A-6-16804 and the like can be mentioned.

  Oxetane compounds are commercially available, and 3-ethyl-3- (phenoxymethyl) oxetane (POX), di [1-ethyl (3-oxetanyl)] methyl ether (DOX), 3-ethyl-3-, manufactured by Toagosei Co., Ltd. (2-ethylhexyloxymethyl) oxetane (EHOX), 3-ethyl-3-{[3- (triethoxysilyl) propoxy] methyl} oxetane (TESOX), oxetanylsilsesquioxane (OX-SQ), phenol novolak And oxetane (PNOX-1009).

The component (B) essentially contains an oxetane compound, but an oxetane compound and other cationically polymerizable compounds (hereinafter referred to as other cationically polymerizable compounds) can also be used in combination.
Other cationic polymerizable compounds include epoxy compounds, vinyl ethers, carbonate compounds, and the like.

As an epoxy compound, if it is a compound which has an epoxy group, it will not specifically limit, A liquid or solid can be used.
Examples of the epoxy compound include aromatic epoxy compounds and alicyclic epoxy compounds and aliphatic epoxy compounds.

  Examples of aromatic epoxy compounds include bisphenol-type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, and brominated bisphenol A diglycidyl ether; Novolak type epoxy resins such as cresol novolac type epoxy resins; biphenyl type epoxy resins having a biphenyl skeleton, naphthalene ring-containing epoxy resins, dicyclopentadiene type epoxy resins having a dicyclopentadiene skeleton, triphenylmethane type epoxy resins, triphenylmethane Type epoxy resin, triglycidyl isocyanurate and the like.

  As the alicyclic epoxy compound, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene monoepoxide, ε-caprolactone modified 3, Examples include 4-epoxycyclohexylmethyl 3 ′, 4′-epoxycyclohexanecarboxylate, 1-methyl-4- (2-methyloxiranyl) -7-oxabicyclo [4,1,0] heptane.

  Examples of aliphatic epoxy compounds include n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, 1,6-hexanediol glycidyl ether, 1,4-butanediol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, trimethylolpropane diglycidyl. Examples include ether, diethylene glycol diglycidyl ether, and 1,2-epoxydodecane.

  The vinyl ether is not particularly limited as long as it is a cationically polymerizable compound having a vinyl ether group, and known ones can be used. Examples of such vinyl ether compounds include alkyl vinyl ethers, aromatic vinyl ethers, α-substituted vinyl ethers, β-substituted vinyl ethers, and polyfunctional compounds having two or more functional groups in the molecule (divinyl ethers, trivinyl ethers, Vinyl ethers) and the like.

  Examples of the alkyl vinyl ethers include monofunctional or polyfunctional vinyl ether compounds and allyl ether compounds containing a hydrocarbon group. Specific examples of the monofunctional vinyl ether compound include, for example, ethyl vinyl ether, n-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-propyl vinyl ether, t-butyl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether. Alkyl vinyl ethers such as: aromatic vinyl ethers having an aromatic hydrocarbon group such as phenyl or benzyl in the molecule.

  Examples of the polyfunctional compound include divinyl ethers such as triethylene glycol divinyl ether, 1,4-cyclohexane diallyl ether, and trimethylolpropane divinyl ether; bifunctional compounds such as aromatic divinyl ethers such as bisphenol-A divinyl ether; Trifunctional compounds such as trimethylolpropane trivinyl ether; and tetrafunctional compounds such as pentaerythritol tetravinyl ether.

  The α-substituted vinyl ethers are vinyl ether compounds having a substituent such as an alkyl group or an allyl group at the α-position, such as α-methyl vinyl ethyl ether, α-ethyl vinyl ethyl ether, α-phenyl vinyl ethyl, Examples include ether. The β-substituted vinyl ethers are vinyl ether compounds having a substituent such as an alkyl group or an allyl group at the β-position, for example, β-methyl vinyl ethyl ether, β-methyl vinyl isopropyl ether, β-methyl vinyl n -Butyl ether, (beta) -methyl vinyl isobutyl ether, (beta) -methyl vinyl t-butyl ether, etc. are mentioned.

Examples of the carbonate compound include a cyclic carbonate compound and a dithiocarbonate compound. Especially, the carbonate type compound which has hardening expansibility is suitable at the point which can control hardening shrinkage and can provide the outstanding pattern formation property.
Examples of the cyclic carbonate compound include 2-dimethylpropyl carbonate and the like, and other compounds include those described in JP-A-2006-266608.

(B) As a component, even if it uses the above-mentioned compound independently, it can also be used in combination of multiple types.
Among these, it is preferable to use an oxetane compound alone or a combination of an oxetane compound and an epoxy compound or / and a vinyl ether compound, and to use an oxetane compound alone or to use an oxetane compound and an epoxy compound in combination. Is more preferable.
As the component (B), a compound having one oxetanyl group (hereinafter referred to as monofunctional oxetane) in the oxetane compound, and a compound having one cationic polymerizable group (hereinafter referred to as monofunctional cationic polymerization) as the cationic polymerizable compound. A cured film finally obtained from the main component (referred to as a functional compound) is preferred because of its excellent flexibility. Specifically, what contains 50-100 weight% of monofunctional oxetane or / and a monofunctional cation polymeric compound in (B) component is preferable.
Since the finally obtained cured film has excellent adhesive performance, it is preferable to adjust the usage ratio so that the Tg transition temperature of the cured film after polymerizing the component (B) is −10 ° C. or lower. .

1-3. Component (C) The component (C) is a radical polymerization initiator and is used for the purpose of polymerizing the component (A).
As the component (C), a thermal radical polymerization initiator is used when the component (A) is thermally polymerized in the first step, and a photoradical is used when the component (A) is photopolymerized in the first step. A polymerization initiator is used.

Various thermal radical polymerization initiators can be used as long as the component (A) can undergo thermal radical polymerization, and examples thereof include organic peroxides, organic hydroperoxides, organic peroxyketals, and azo compounds.
Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, diacetyl peroxide, didecanoyl peroxide, diisono Nile peroxide and 2-methylpentanoyl peroxide are mentioned.
Examples of the organic hydroperoxide include tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane, p-methane hydroperoxide, and diisopropylbenzene hydroperoxide. -Oxide etc. are mentioned.
Examples of organic peroxyketals include 1,1-bis (tert-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-hexylperoxy) cyclohexane and 1,1. -Bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane and the like.
Examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobiscyclohexylnitrile, and 1,1′-azobis. (Cyclohexane-1-carbonitrile), 2-phenylazo-4-methoxy-2, 4-dimethylvaleronitrile, dimethyl-2, 2′-azobisisobutyrate and the like.

As the radical photopolymerization initiator, various compounds can be used as long as they can radically polymerize the component (A), and examples thereof include acetophenone, ketone, and benzoin ether.
Examples of acetophenone include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone and 2-hydroxy-2-cyclohexylacetophenone.
Examples of the ketone include benzophenone, 2-chlorobenzophenone, p, p′-dichlorobenzophenone, p, p′-bisdiethylaminobenzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler's ketone) and 4 -(2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like.
Examples of the benzoin ether include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl methyl ketal, and benzoyl benzoate.
In addition to these, α-acyloxime ester and thioxanthone can be mentioned,
The photopolymerization initiator can be used in combination with a sensitizer as necessary. Examples of the sensitizer include n-butylamine, triethylamine, and tri-n-butylphosphine.

Although the component (C) is used alone, it can usually be used in combination of two or more kinds because it improves various properties of the molded product.
As the component (C), a thermal radical polymerization initiator and a photo radical polymerization initiator can be used in combination as necessary.
Component (C) may be added all at once in the first step, or may be added in portions.

  The proportion of the component (C) in the composition in the first step is preferably 0.01 to 2.0 parts by weight, more preferably 0.05 to 0.10 parts by weight in 100 parts by weight of the composition. is there.

In the present invention, the method in which the component (A) is thermally polymerized in the first step is preferable in terms of easy control of the polymerization. Therefore, the component (C) is preferably a thermal polymerization initiator.
Furthermore, as the thermal polymerization initiator, an azo compound is preferable because it is difficult to cause gelation in the polymerization of the component (A) and the reaction control is easy.

1-4. Method of performing the first step The first step is a step of polymerizing the component (A) by heating the composition containing the components (A) to (C) with stirring or irradiating active energy rays. .

In the first step, first, a composition containing the above-described components (A) to (C) is prepared.
As the said method, what is necessary is just to stir and mix said (A)-(C) component according to a conventional method. In this case, defoaming can be performed as necessary.

In the first step, the component (A) is polymerized using the composition obtained above.
The degree of polymerization of the component (A) in this case may be appropriately set according to the purpose, and the weight average molecular weight after polymerization (hereinafter referred to as Mw) is preferably 10,000 to 2,000,000, more preferably Mw Is 100,000 to 1,000,000.
By making Mw of the polymer after the first step 10,000 or more, the polymer finally obtained can be tough, and it is excellent when applied to pressure-sensitive adhesive sheet production, When Mw is 2 million or less, the viscosity becomes low, so that castability is excellent, and when applied to the production of an adhesive sheet, it is excellent in handling.

As the composition in the first step, it is preferable to adjust the type of the component (A) and the blending ratio in the composition so that the polymer as described above can be obtained.
As a ratio of the component (A) and the component (B) in the composition in the first step, the component (A) is 60 to 95% by weight based on the total amount of the component (A) and the component (B) (B The component is preferably 5 to 40% by weight.
By setting the proportion of the component (A) to 60% by weight or more, the physical properties of the finally obtained polymer can be easily prepared. Especially when the polymer is used as an adhesive, Adjustment can be facilitated. On the other hand, when the content is 95% by weight or less, the castability and handling properties can be improved.
In addition, when mix | blending (B) component at a 2nd process, it is preferable to satisfy | fill the said ratio as a total amount of the (A) component and (B) component which were finally used.

When the component (A) is thermally polymerized in the first step, a thermal radical polymerization initiator is used as the component (C).
What is necessary is just to set suitably as conditions of thermal polymerization according to the kind and quantity of (A) and (C) component to be used, and the molecular weight of the polymer obtained.
The heating temperature is preferably less than the boiling point of the contents because it can be used for normal pressure equipment with an inexpensive device, and more preferably 100 ° C. or less is water used as a refrigerant for temperature control of the reactor It is preferable from the point which can be performed.
The polymerization time for heating control is preferably 20 hours or less because the production cost can be reduced.

When the component (A) is photopolymerized in the first step, a photo radical polymerization initiator is used as the component (C).
Examples of light include visible light and ultraviolet light, and ultraviolet light is preferred because of excellent curability.
Specific examples of preferred light sources include high pressure mercury lamps, medium pressure mercury lamps, metal halide lamps, microwave-excited electrodeless mercury lamps, xenon lamps, and ultraviolet LEDs.
What is necessary is just to set suitably as conditions of light irradiation according to the kind and quantity of (A) and (C) component to be used, and the molecular weight of the polymer obtained.
In this case, a reactor equipped with a light irradiation device on a stirring blade can be used.

  In the present invention, the method in which the component (A) is thermally polymerized in the first step is preferable in that the polymerization can be easily controlled.

It is preferable that the glass transition temperature (hereinafter referred to as Tg) of the polymer after the fourth step is −10 ° C. or less because of excellent adhesion performance.
Therefore, the Tg of the polymer after the first step is also preferably −10 ° C. or less, and preferably −10 to −100 ° C.
In order to satisfy the Tg, it is preferable to use a combination of the components (A) described above.

In the polymerization, a chain transfer agent may be added as necessary for the purpose of preventing gelation and adjusting the molecular weight as desired.
Examples of chain transfer agents include thiol chain transfer agents and halogenated hydrocarbon chain transfer agents, and thiol chain transfer agents are preferred.
The ratio of the chain transfer agent is preferably 0.1 parts by weight or less with respect to 100 parts by weight of the composition because the weight average molecular weight suitable as a pressure-sensitive adhesive is easily adjusted to 200,000 or more.

The thiol chain transfer agent has a —SH group, and those represented by the following general formula are particularly preferable.
HS-R-Eg
(In the formula, R represents a group derived from a hydrocarbon having 1 to 4 carbon atoms, E represents an —OH, —COOM, —COOR ′ or —SO ₃ M group, and M represents a hydrogen atom, a monovalent metal) Represents a divalent metal, an ammonium group or an organic amine group, R ′ represents an alkyl group having 1 to 10 carbon atoms, and g represents an integer of 1 to 2).
Specific examples of the compound include, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, and octyl 3-mercaptopropionate. From the viewpoint of excellent chain transfer effect, mercaptopropionic acid and mercaptoethanol are preferable, and mercaptopropionic acid is more preferable.
Examples of the halogenated hydrocarbon chain transfer agent include carbon tetrachloride and carbon tetrabromide.
Examples of other chain transfer agents include α-methylstyrene die or pinolene, α-terpinene, γ-terpinene, dipentene, 2-aminopropan-1-ol and the like. A chain transfer agent can use 1 type (s) or 2 or more types.
These chain transfer agents can be used alone or in combination of two or more.

2. Second Step The second step is a step of adding the component (D) to the reaction liquid containing the polymer obtained in the first step.

The photocationic polymerization initiator as the component (D) is blended for the purpose of polymerizing the component (B) by light irradiation.
As the component (D), various compounds can be used as long as they can polymerize the component (B), and examples thereof include a sulfonium salt, an iodonium salt, a phosphonium salt, and a pyridinium salt.

Examples of the sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, bis (4- (diphenylsulfonio) -phenyl) sulfide-bis (hexafluorophosphate), bis (4- (diphenylsulfo). Nio) -phenyl) sulfide-bis (hexafluoroantimonate), 4-di (p-toluyl) sulfonio-4'-tert-butylphenylcarbonyl-diphenylsulfide hexafluoroantimonate, 7-di (p-toluyl) sulfonio And 2-isopropylthioxanthone hexafluorophosphate and 7-di (p-toluyl) sulfonio-2-isopropylthioxanthone hexafluoroantimonate.
In addition to these, aromatic sulfonium salts described in JP-A-6-184170, JP-A-7-61964, JP-A-8-165290, U.S. Pat. No. 4,231,951, U.S. Pat. Can be mentioned.

Examples of the iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, and the like.
In addition to these, aromatic iodonium salts described in JP-A-6-184170, US Pat. No. 4,256,828 and the like can be mentioned.

Examples of the phosphonium salt include tetrafluorophosphonium hexafluorophosphate and tetrafluorophosphonium hexafluoroantimonate.
In addition to these, aromatic phosphonium salts described in JP-A-6-157624 can be exemplified.
Examples of the pyridinium salt include pyridinium salts described in Japanese Patent No. 2519480, JP-A-5-222112, and the like.

The anion as the component (D) is preferably SbF ⁶⁻ or borate in that the reactivity is improved.
As the borate, tetrakis (pentafluorophenyl) borate is preferable.

  The sulfonium salt and iodonium salt can be easily obtained from the market. Examples of commercially available products include sulfonium salts such as Union Carbide UVI-6990 and UVI-6974, Asahi Denka Kogyo Co., Ltd. Adekaoptomer SP-170 and Adekaoptomer SP-172, and Rhodia Corporation. No. PI 2074, Ciba Irgacure 250, Wako Pure Chemical Industries, Ltd. WPI-016, WPI-116, and other iodonium salts.

In addition, since the effect of the component (D) as a photosensitizer can be exhibited and the curability of the component (C) can be improved, it is preferable to use it together with a radical photopolymerization initiator.
Examples of the photo radical polymerization initiator include the same ones as described above, and preferred specific examples include thioxanthone such as benzophenone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 2,4-dichlorothioxanthone. Benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl- Α-hydroxyalkylphenones such as 1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone and camphorquinone α -A dicarbonyl compound etc. are mentioned.
The combined proportion of the radical photopolymerization initiator is preferably 0.1 to 5.0% by weight with respect to the component (D).

Further, a sensitizer can be used in combination to increase the activity of the component (D). As a sensitizer that can be used in the present invention, it is possible to use a compound disclosed by Crivello in Advanced in Polymer Science (Adv. In Polymer Sci., 62, 1 (1984)).
Specific examples include pyrene, perylene acridine orange, thioxanthone, 2-chlorothioxanthone, and benzoflavine.
The combined use ratio of the sensitizer is preferably 0.1 to 5.0% by weight with respect to the component (D).

As a method of adding and mixing the component (D) to the reaction solution containing the polymer obtained in the first step, a conventional method may be followed. In this case, defoaming can be performed as necessary.
The proportion of the component (D) may be set according to the type and purpose of the component (B), but is preferably 0.01 to 5.0% by weight, more preferably 0.5 to 2 in the mixture. 0.0% by weight.

  In the second step, component (B) can be further added as necessary.

In the second step, it is preferable to adjust to a viscosity suitable for coating in the third step.
The desired viscosity is measured using a BM viscometer using a rotor: No. As a viscosity set on the conditions of 4 rotor, rotation speed 12rpm, measurement temperature: 30 degreeC, 100-100,000 mPa * s is preferable, More preferably, it is 1000-30,000 mPa.s. s.
This viscosity is 100 mPa.s. By setting it as s or more, the liquid flow at the time of apply | coating to a base material can be prevented, and application | coating becomes easy by moderate viscosity by setting it as 100,000 mPa * s or less.

3. Third Step The third step is a step of applying the mixture obtained in the second step to the substrate.

The base material may be appropriately selected according to the purpose, and may be a material for adhesion (hereinafter referred to as an adherend), or a releasable material independent of the adherend (hereinafter referred to as an adherend). It may be a release material).
Examples of the substrate include plastic, glass, ceramics, and metal.
Examples of plastics include polyolefins such as polyethylene, polypropylene, and cyclic polyolefins (resins obtained from cyclic olefins such as norbornene and tetracyclododecene and their derivatives); polyvinyl chloride resins, polyvinylidene chloride, chlorinated polypropylene, and the like Chlorinated plastics; polystyrene; cellulosic resins; acrylonitrile-butadiene-styrene resins (ABS resins); polymethyl methacrylate; polyamides; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; polycarbonates; polyurethanes; And ethylene-vinyl acetate copolymer. Depending on the intended use, it is also possible to use a material whose surface is subjected to treatment such as metal vapor deposition.
Examples of ceramics include oxides, composite oxides, and nitrides of various metals such as silicon, aluminum, zinc, indium, tin, titanium, barium, zirconium, cerium, and yttrium.
Examples of the metal include iron, aluminum, copper, zinc, and stainless steel.
The plastic is preferably a sheet or film.
Examples of the release material include non-surface-treated OPP film (polypropylene), silicone-treated polyethylene terephthalate (PET) film, and paper whose surface is silicone-treated.
When the polymer is adhered, an activation treatment can be performed on one or both surfaces in order to increase the interlayer adhesion. Examples of the surface activation treatment include plasma treatment, corona discharge treatment, chemical treatment, surface roughening treatment, etching treatment, and flame treatment, and these may be used in combination.

As a coating method for the base material, a conventionally known method may be used. Lip coater, slot die, microgravure (registered trademark of Yasui Seiki) screen printing, natural coater, knife belt coater, floating knife, knife Examples of the method include over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, reverse roll, air blade, curtain flow coater, and gravure coater.
The coating thickness in this case may be appropriately set according to the substrate to be used, application, purpose, etc., but is preferably 0.1 μm to 1 mm, more preferably 1 to 500 μm.

4). Fourth Step The fourth step is a step of polymerizing the component (B) by irradiating the coated surface of the base material obtained in the third step with light. In this case, another substrate can be bonded to the coated surface and irradiated with light. In this case, the light irradiation may be from either the original base material side or the other base material side. However, either the original substrate or the other substrate needs to be transparent.
Examples of light include visible light and ultraviolet light, and ultraviolet light is preferred because of excellent curability.
Specific examples of preferable light sources include chemical lamps, high-pressure mercury lamps, medium-pressure mercury lamps, metal halide lamps, microwave-excited electrodeless mercury lamps, xenon lamps, and ultraviolet LEDs.
What is necessary is just to set suitably as light irradiation conditions according to the kind, quantity, purpose, etc. of the (B) and (D) component to be used.

  The reason why the glass transition temperature (hereinafter referred to as Tg) of the polymer after the fourth step is −10 ° C. or lower is preferable because the adhesive performance is excellent.

In this case, after the mixture obtained in the second step is applied to the base material in the third step, and this is bonded to another base material, a method of irradiating light can also be performed.
In this case, the light irradiation includes a method of irradiating from the surface of any one of the substrates. In this case, at least one of the first base material and the second base material is transparent.

  What is necessary is just to set suitably the thickness of the adhesion layer in the adhesive sheet finally obtained according to light irradiation conditions, a base material, a use, an objective, etc., Preferably it is 0.1 micrometer-1 mm, More preferably, it is 1-. 500 μm.

In the case of using a flexible base material (hereinafter referred to as “flexible base material”) such as a plastic film as the base material, the third step and the fourth step are not limited to a flat state but in a curved state. It can also be done.
That is, there is a method in which a flexible base material is bent into a concave state or a convex state, and after applying the composition in this state, the other flexible base material is bonded and irradiated with light.
As another method, the composition of the present invention is applied in a flat state on a flexible base material, and the other flexible base material is bonded together, bent into a concave state or a convex state, and irradiated with light for adhesion. The method of doing is mentioned.
In this case, in the third stage, the above-described method may be followed as a method of applying the composition in a planar state. Examples of the method for coating the composition in a curved surface include a method using a spray, a dip, a curtain flow coater, screen printing, a slot die coater and the like.

5. Other components In the present invention, the components (A) to (D) are used as essential components, but various known additives (collectively combining them) are within the range not detracting from the object of the present invention. Other components) can be added. As other components, the polymer obtained in the present invention can be preferably used as a pressure-sensitive adhesive, particularly preferably used as a pressure-sensitive adhesive sheet material, and is preferably selected as appropriate from the viewpoint of improving sheet properties in actual use. .

  The other components may be added according to the purpose, and may be selected at the time of preparing the composition in the first step or at the time of adding or mixing the component (D) in the second step.

When a functional group-containing unsaturated compound is used as the component (A), a polymer having a crosslinked structure can be obtained in combination with a crosslinking agent.
Examples of the crosslinking agent include polyisocyanate crosslinking agents, silicone crosslinking agents, epoxy crosslinking agents, alkyl etherified melamine crosslinking agents, and the like.
The cross-linking agent is preferably added in the second step.

As a method other than the above method for forming a crosslinked structure in a polymer, there is a method using a polyfunctional monomer in combination.
Examples of the polyfunctional monomer are the same as those mentioned above.
When the polyfunctional monomer is added in the first step, the polymer of the component (A) may be gelled. Therefore, the polyfunctional monomer is preferably added in the second step.
In the case of using a polyfunctional monomer, when the component (A) is polymerized by thermal radical polymerization in the first step, it is preferable to add a photo radical polymerization initiator in the second step.

Other components other than the above include, for example, fillers, silane coupling agents, fiber reinforcing materials, polymerization inhibitors, curing accelerators, low shrinkage agents, thickeners, internal mold release agents, dispersants, plasticizers, lubricants. , Film formation aids, release agents, antifoaming agents, heat resistance imparting agents, flame retardant imparting agent agents, antistatic agents, surfactants, conductivity imparting agents, ultraviolet sensitizers, antifogging agents, antibacterial / antipreventive Examples include mold agents, photocatalysts, fillers, dyes and pigments.
Other components may be blended individually, or may be blended as appropriate by combining two or more kinds from the handling properties to be blended.

  Furthermore, a coupling agent such as a silane coupling agent can be added to the composition of the present invention for the purpose of improving the adhesion of the cured product to the inorganic material. Suitable silane coupling agents include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-303), γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-403). ), Γ-glycidoxypropyltriethoxysilane (manufactured by Shin-Etsu Chemical, KBE-403), γ-glycidoxypropylmethyldiethoxysilane (manufactured by Shin-Etsu Chemical, KBM-402), 3-ethyl-3-{[3 -(Triethoxysilyl) propoxy] methyl} oxetane (manufactured by Toagosei Co., Ltd., OXT-610).

As filler, aluminum, magnesium hydroxide, alumina powder, silica, synthetic smectite, synthetic zeolite, magnesium titanate, synthetic basic lithium carbonate / aluminum salt, synthetic basic lithium carbonate / magnesium salt, synthetic calcium silicate, synthetic silicic acid Examples include magnesium, orlastonite, nepheline site, talc, diatomaceous earth, miker, glass powder, and various organic polymer fine particles.
When used as a pressure-sensitive adhesive sheet, it is preferable to appropriately select and use the particle size and refractive index in consideration of the transparency not decreasing.
Examples of the fiber reinforcing material include glass fiber, carbon fiber, organic fiber, potassium titanate fiber and the like, and those having a fiber length of 1 to 20 mm, preferably 3 to 10 mm are used.
In addition, these fine powders and fibrous fillers may be surface-treated with a silane or titanate coupling agent in advance from the viewpoint of compatibility with the syrup composition of the present invention and dispersibility, Moreover, a suitable dispersing agent can be used in combination as appropriate.
These may be used alone or in combination of two or more.

6). Applications The obtained pressure-sensitive adhesive sheet can be used for applications such as protective films, double-sided tapes, and labels.
More specifically, various adhesives such as packaging adhesive tape, office adhesive tape, medical adhesive product, agricultural adhesive product, electrical insulating tape, masking tape or sheet, adhesive label, double-sided adhesive tape and special adhesive tape. Can be used for processed agents.
In addition, in applications that require particularly high adhesive performance, in addition to bonding metals and glass used in automobiles, etc., adhesive tapes, adhesive labels, special adhesive tapes, polarizing plates used for electrical and electronic parts. It can be used for adhesive tapes or sheets for optical parts such as, adhesive labels and the like.
Furthermore, it can be used for the production of automobile parts, the production of electricity and electronic parts, and the production of optical parts such as polarizing plates.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the following description, unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”.
Mw was measured according to the following method.
<Mw measurement>
It was determined by GPC (gel permeation chromatography). TSKgel GMHXL and TSKgel G2500HHR manufactured by Tosoh Corporation were used for the column, TSKguardcolumn HXL-H and TSKguardcolumn HHR-L were used for the card column, and THF (tetrahydrofuran) was used for the solvent.

Example 1
<First step>
Set a 1-liter round bottom flask in about 2.8 liters of silicone oil in a 5-liter oil bath equipped with a condenser, nitrogen gas inlet tube, thermometer, and stirrer. -108 g of ethylhexyl (hereinafter referred to as EHA) and 12 g of 4,4-hydroxybutyl acrylate (hereinafter referred to as 4HBA), and 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (hereinafter referred to as (B) component) 200 g of EHOX) and 0.2 g of chain transfer agent n-dodecyl mercaptan (hereinafter referred to as nDM) are added, and after purging with nitrogen, the temperature in the oil bath and flask is heated to 70 ° C. under external temperature control. did.
Next, 0.05 g of 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile (hereinafter referred to as V-70) manufactured by Wako Pure Chemical Industries, Ltd. was added as component (C) with stirring. As the polymerization reaction progressed, the temperature in the flask rose to about 94 ° C. Since the temperature of the oil bath at that time was about 71 ° C., the temperature difference (hereinafter referred to as Δt) was 23 ° C. It was.
About 40 minutes after the previous V-70 was added, the temperature in the flask returned to 70 ° C. As the first follow-up, 0.025 g of V-70 was added. At that time, Δt was less than 1 ° C.
When 10 minutes after the first follow-up, 80 g of EHA and 0.08 g of nDM were added, the temperature in the flask rose again and Δt became 9 ° C. Stirring was continued as it was.
Therefore, 0.025 g of V-70 was added with stirring, but Δt was less than 1 ° C.
The oil bath temperature was maintained at 70 ° C. for 3 hours.
The obtained reaction liquid containing the polymer (hereinafter referred to as syrup) was a colorless and transparent viscous liquid. As a result of analyzing the unreacted components by gas chromatography, the unreacted EHA concentration was 1.9%. Further, since the polymer concentration of the obtained syrup was about 50% by weight, it was confirmed that EHOX remained unreacted. The viscosity of the syrup was 2800 mPa · S in an atmosphere at 25 ° C. The polymer contained in the syrup had an Mw of 180,000 and an Mw of 42,000.

<Second step>
For 100 parts of the syrup obtained, 4.0 parts of diallyliodonium hexafluoroantimonate (trade name: WPI-016: manufactured by Wako Pure Chemical Industries) as component (C), pentaerythrityl 0.05 parts tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name Irganox 1010: manufactured by Ciba Japan), 1-hydroxy-cyclohexyl- as a sensitizer 1.0 part of phenyl-ketone (trade name Irgacure 184: manufactured by Ciba Japan) and 0.5 part of 2,4-diethylthioxanthone were added, mixed and defoamed, and the composition (hereinafter photocurable). Syrup) was prepared.

<3rd process and 4th process>
The obtained photocurable syrup was applied to a 50 μm-thick PET separator having a double-sided release treatment to a thickness of 50 μm.
Next, the adhesive sheet was passed 8 times at an irradiation distance of 10 cm and a line speed of 8 m / min with a high-pressure mercury lamp at an output of 3 KW using an eye graphics ultraviolet ray irradiator ECS-401GX. Manufactured.
The obtained pressure-sensitive adhesive sheet is a sheet having a transparent appearance. When the pressure-sensitive adhesive strength is measured according to JIS Z 0237, a strength of 70 g / 25 mm width is obtained, and the holding power is maintained at 40 ° C. for 3 hours. It was an adhesive sheet with excellent heat resistance.

(Example 2)
For 100 parts of the syrup obtained in the second step of Example 1, diallyl iodonium hexafluoroantimonate is added as a component (C) to tricumyl iodonium tetrakis (pentafluorophenyl) borate (trade name: PHOTOINITIATOR 2074: Rhodia The photocurable syrup was prepared in the same manner as in Example 1 except that the amount was 4.0 parts.
The third step and the fourth step were performed in the same manner as in Example 1 to produce an adhesive sheet.
The obtained pressure-sensitive adhesive sheet was transparent even after UV curing. When the pressure-sensitive adhesive force was measured, the pressure-sensitive adhesive sheet was 60 g / 25 mm wide, and the holding power was excellent at 40 ° C. for 3 hours.

(Example 3)
Except for adding 10 parts of γ-glycidoxypropyltrimethoxysilane (trade name: KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent to 100 parts of the syrup obtained in the second step of Example 1. Prepared a photocurable syrup in the same manner as in Example 1.
The third step and the fourth step were performed in the same manner as in Example 1 to produce an adhesive sheet.
The obtained pressure-sensitive adhesive sheet was transparent even after UV curing. When the adhesive strength was measured by the same method as in Example 1, the strength was 20 g / 25 mm width, and the holding power was excellent at 3 hours at 40 ° C. It was an adhesive sheet.

Example 4
For 100 parts of the syrup obtained in the second step of Example 1, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate (trade name: Celoxide) was used as another cationic polymerization compound. 2021P (manufactured by Daicel Chemical Industries) was used to prepare a photocurable syrup in the same manner as in Example 1.
The third step and the fourth step were performed in the same manner as in Example 1 to produce an adhesive sheet.
The obtained pressure-sensitive adhesive sheet was transparent even after UV curing, and the adhesive strength was measured by the same method as in Example 1. As a result, the strength was 12 g / 25 mm width and the holding power was excellent at 3 hours at 40 ° C. It was an adhesive sheet.

(Example 5)
Photocurability in the same manner as in Example 1 except that 20 parts of n-butyl vinyl ether was added as another cationic polymerization compound to 100 parts of the syrup obtained in the second step of Example 1. Adjusted the syrup.
The third step and the fourth step were performed in the same manner as in Example 1 to produce an adhesive sheet.
The obtained pressure-sensitive adhesive sheet was transparent even after UV curing, and the pressure-sensitive adhesive strength was 63 g / 25 mm width. The pressure-sensitive adhesive sheet was an excellent pressure-sensitive adhesive sheet having a holding power of 3 hours at 40 ° C.

(Comparative Example 1)
In the first step of Example 1, 200 g of EHOX as component (B) was not used, but 200 parts of EHA was used instead (total EHA 388 g), and polymerization was carried out as the polymerization reaction progressed. The temperature rose to about 175 ° C. or higher, that is, Δt 100 ° C. or higher, and the contents were ejected, and no further polymerization reaction could be performed.

(Comparative Example 2)
In the first step of Example 1, 200 g of toluene as a solvent was used instead of 200 g of component (B) EHOX, and the temperature in the flask increased to about 94 ° C. as the polymerization reaction progressed. did. Since the temperature of the oil bath at that time was about 71 ° C., its Δt was 23 ° C., and the subsequent initial polymerization was similar to that of Example 1.
The obtained composition was removed under reduced pressure to remove toluene, and instead, EHA as component (A) was added to adjust the polymer concentration in the syrup to about 50%. The viscosity of the syrup was 3400 mPa · S at 25 ° C. atmosphere. The polymer Mw in the syrup was 250,000.
Using the obtained syrup, according to the same method as in Example 1, the second to fourth steps were carried out to produce a pressure-sensitive adhesive sheet. As a result, the ultraviolet curing reaction did not proceed and the liquid sheet remained in a liquid state. This is thought to be because the radical reaction does not proceed under the oxygen content.

(Comparative Example 3)
In the first step of Example 1, component (B) EHOX is converted to 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate (trade name Celoxide 2021: manufactured by Daicel Chemical), which is an epoxy compound. When superposition | polymerization was implemented by replacing, the obtained syrup was a viscous liquid which became cloudy.
Using the obtained syrup, according to the same method as in Example 1, the second to fourth steps were carried out to produce a pressure-sensitive adhesive sheet. After UV curing, the turbidity further progressed and the total line transmittance was 50. % Or less. This seems to have caused phase separation because the compatibility between the epoxy compound used and the EHA polymer was not good. Further, when the adhesive strength was measured in the same manner as in Example 1, the strength was 10 g / 25 mm width, and the holding strength dropped within 5 minutes at 40 ° C., making it unsuitable as an adhesive sheet.

From the above results, in the production method of the present invention, since polymerization is performed using the composition containing the components (A) to (C) in the first step, only the component (A) advances the polymerization reaction, and the unreacted ( Since the component (B) serves as a solvent, the reaction heat rises slowly, and a syrup having an appropriate viscosity can be easily obtained.
Further, after blending component (D) in the second step, the reaction proceeds mainly with component (C) by irradiating ultraviolet rays with the syrup in a smooth sheet state in the third step. The reaction proceeds promptly without the deoxygenation step. Moreover, the obtained adhesive sheet became excellent in transparency and heat resistance.

According to the present invention, a pressure-sensitive adhesive sheet can be produced from a syrup that is safe and excellent in productivity. The obtained pressure-sensitive adhesive sheet can also be used for applications such as protective films, double-sided tapes, labels, etc., automobile parts, electrical and electronic parts, and optical parts.

Claims (9)

The manufacturing method of the adhesive sheet containing the following process.
First step: Stirring a composition containing a compound (A) having one ethylenically unsaturated group, an oxetane compound or an oxetane compound, a cationic polymerization compound (B) other than this, and a radical polymerization initiator (C) The component (A) is polymerized by heating downward or irradiating with active energy rays.
-2nd process: A photocationic polymerization initiator (D) is added and mixed with the reaction liquid obtained at the 1st process.
-3rd process: The mixture obtained at the 2nd process is apply | coated to a base material.
-4th process: Light-irradiate the application surface of the base material obtained at the 3rd process, and polymerize the said (B) component.   The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein the component (A) is a compound having one (meth) acryloyl group.   The manufacturing method of the adhesive sheet of Claim 2 in which the said (A) component contains a hydroxyl-containing (meth) acrylate.   The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the component (B) is only an oxetane compound.   The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the component (B) is a mixture of an oxetane compound and an epoxy compound.   The pressure-sensitive adhesive according to any one of claims 1 to 5, wherein in the first step, the composition comprises the component (A) at 60 to 95% by weight and the component (B) at 5 to 40% by weight. Sheet manufacturing method.   The viscosity of the reaction liquid obtained at the 1st process is 200mPa * S-100,000mPa * s, The manufacturing method of the adhesive sheet in any one of Claims 1-6.   The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the polymer glass transition temperature after light irradiation in the third step is -10 ° C or lower.   The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 8, wherein in the first step, a thermal polymerization initiator is used as the component (C) and the polymerization is performed by heating with stirring.