JP2013001762A - Removable self-adhesive tape and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removable self-adhesive tape which has excellent heat resistance and little increase in adhesive force during removal, and which leaves no adhesive residue or contamination on the adherend.SOLUTION: The removable self-adhesive tape is formed from a heat-resistant film substrate and a cured adhesive layer on one surface of the heat-resistant film substrate, wherein the cured adhesive layer is formed by photocuring an adhesive layer formed from an adhesive composition containing 0.15-4.0 pts.wt. of a photo-cationic polymerization initiator per 100 pts.wt. of a graft polymer formed by graft polymerization of chains containing cyclic ether group-containing monomers onto a (meth)acrylic polymer.

Description

  The present invention relates to a re-peeling pressure-sensitive adhesive tape and a method for producing the same. More specifically, the present invention relates to a re-peeling pressure-sensitive adhesive tape which is excellent in heat resistance and re-peeling property without causing contamination of an adherend and a method for producing the same.

  Various boards and wiring boards are used in electronic equipment, and masking tape is used to protect electronic parts and circuits when mounting components on the board, creating lead frames, soldering, and heat treatment. Is done. In such use, when masking tape is affixed, there is no lifting in the process, and there is little increase in adhesive force when peeling after heating process, etc. There must be no glue residue or contamination.

  Various proposals have been made for such demands. For example, a heat-resistant re-peeling adhesive tape has been proposed in which a heat-resistant backing film layer is provided with a pressure-sensitive adhesive layer obtained by crosslinking an acrylic polymer obtained by copolymerizing glycidyl (meth) acrylate and (meth) acrylic acid (Patent Document) 1) Furthermore, an adhesive obtained by crosslinking an acrylic polymer obtained by copolymerizing a carboxyl group-containing monomer with an epoxy-based crosslinking agent is disclosed. (Patent Document 2)

JP-A-2005-53975 JP-A-5-163468

The present invention has excellent heat resistance, adhesiveness that does not cause floating in various processes after pasting, little increase in adhesive force in the heating process, and no adherend residue or contamination on the adherend. It aims at providing the adhesive tape for re-peeling.

  As a result of intensive studies to solve the above problems, the present inventors have found the following adhesive tape for re-peeling and have completed the present invention.

That is, the present invention is a pressure-sensitive adhesive tape for re-peeling comprising a heat-resistant film substrate and a cured adhesive layer on one side of the heat-resistant film substrate,
A photocationic polymerization initiator 0.15-4. Is added to 100 parts by weight of a graft polymer obtained by graft-polymerizing a chain containing a cyclic ether group-containing monomer to a (meth) acrylic polymer. The present invention relates to a re-peeling pressure-sensitive adhesive tape which is obtained by photocuring an adhesive layer formed from an adhesive composition containing 0 part by weight.

  It is preferable that the adhesive composition further contains an isocyanate-based crosslinking agent.

  The adhesive composition may further contain 5 to 100 parts by weight of an epoxy resin and / or an oxetane resin with respect to 100 parts by weight of the graft polymer.

  The gel fraction of the cured adhesive layer is preferably 80 to 99%.

  The (meth) acrylic polymer may contain 0.2 to 10% by weight of a hydroxyl group-containing monomer as a monomer unit with respect to the total amount of the (meth) acrylic polymer.

  The graft polymer is composed of 2 to 50 parts by weight of the cyclic ether group-containing monomer and 5 to 50 parts by weight of other monomers to 100 parts by weight of the (meth) acrylic polymer, and 0.02 to 5 parts by weight of peroxide. It can be obtained by graft polymerization in the presence.

  The photocationic polymerization initiator may be a photoacid generator.

  When the photoacid generator is adjusted to a concentration of 10% using ethyl acetate as the solvent, it is preferable that the photoacid generator is dissolved without any precipitate.

The storage elastic modulus at 23 ° C. of the cured adhesive layer may be 9.0 × 10 ^{4 to} 1.0 × 10 ⁶ Pa.

  The heat resistant film substrate may be selected from the group consisting of polyethylene terephthalate, polyimide, aramid, polyethylene naphthalate, and polyphenylene sulfide.

  The adhesive layer may be 0.5-100 μm thick.

The present invention is also a method for producing a releasable pressure-sensitive adhesive tape comprising a cured adhesive layer on one side of a heat-resistant film substrate,
Viscosity comprising 0.15 to 4.0 parts by weight of a photocationic polymerization initiator in 100 parts by weight of a graft polymer obtained by graft polymerization of a chain containing a cyclic ether group-containing monomer to a (meth) acrylic polymer. Applying an adhesive composition to one side of a heat-resistant film substrate to form an adhesive layer; and irradiating the adhesive layer with light and photocuring the adhesive layer;
The manufacturing method including this.

  The re-peeling pressure-sensitive adhesive tape of the present invention can be used for masking pressure-sensitive adhesive tapes for electronic circuit boards and pressure-sensitive adhesive tapes for temporarily fixing electronic components. It has excellent heat resistance, has adhesiveness that does not cause floating in various processes, has no increase in adhesiveness in the heating process, and has an acrylic pressure sensitive adhesive. Excellent low molecular contaminants are not attached.

  The heat-resistant film base material of the present invention and a cured adhesive layer are provided on one side of the heat-resistant film base material. Here, the cured adhesive layer is composed of a (meth) acrylic polymer, a graft polymer obtained by graft polymerization of a chain containing a cyclic ether group-containing monomer, and a photocationic polymerization initiator 0.15 to 4.0. A pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing parts by weight is photocured.

  First, as the monomer unit contained in the (meth) acrylic polymer, any (meth) acrylate can be used and is not particularly limited. Here, preferably, for example, an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms is contained in an amount of 50% by weight or more of the entire (meth) acrylic polymer.

  In the present specification, the term “alkyl (meth) acrylate” simply refers to a (meth) acrylate having a linear or branched alkyl group. The alkyl group has 4 or more carbon atoms, preferably 4 to 9 carbon atoms. (Meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning.

  Specific examples of the alkyl (meth) acrylate include n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, and isopentyl. (Meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl ( (Meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate Rate, n- tetradecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate. Especially, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. can be illustrated and these can be used individually or in combination.

  In this invention, the said alkyl (meth) acrylate is 50 weight% or more with respect to all the monomer components of a (meth) acrylic-type polymer, Preferably it is 80 weight% or more, More preferably, it is 90 weight% or more. Further, all the monomers may be alkyl (meth) acrylates, but are preferably 98% by weight or less, and may be 97% by weight or less.

  In addition to this, it is preferable that the (meth) acrylic polymer of the present invention contains a hydroxyl group-containing monomer containing at least one hydroxyl group in the alkyl group. That is, this monomer is a monomer containing one or more hydroxyalkyl groups. Here, the hydroxyl group is preferably present at the terminal of the alkyl group. Carbon number of an alkyl group becomes like this. Preferably it is 4-12, More preferably, it is 4-8, More preferably, it is 4-6. By including such a hydroxyl group-containing monomer, there is a positive effect on the position at which hydrogen abstraction occurs during graft polymerization and the compatibility between the graft polymer and the homopolymer of the cyclic ether group-containing monomer generated during graft polymerization. It is considered useful for preparing a graft polymer having good heat resistance.

  As such a monomer, those having a polymerizable functional group having an unsaturated double bond of a (meth) acryloyl group and having a hydroxyl group can be used without particular limitation. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxy Hydroxyalkyl (meth) acrylates such as octyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, etc .; 4-hydroxymethylcyclohexyl (meth) acrylate, 4-hydroxybutyl vinyl ether Etc. Of these, hydroxyalkyl (meth) acrylate is preferably used, and 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are particularly preferable.

  The hydroxyl group-containing monomer is preferably 0.02% by weight or more, more preferably 0.05% by weight or more, preferably 10% by weight or less, based on the total amount of monomer components forming the (meth) acrylic polymer. More preferably, it is 3% by weight or less. Most preferably, it is 0.05 to 3% by weight.

  As a monomer component for forming the (meth) acrylic polymer, an unsaturated carboxylic acid-containing monomer can be used in addition to the monomer.

  As the unsaturated carboxylic acid-containing monomer, a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a carboxyl group can be used without any particular limitation. . Examples of the unsaturated carboxylic acid-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. These can be used alone or in combination. Among these, it is preferable to use (meth) acrylic acid, particularly acrylic acid.

  The unsaturated carboxylic acid-containing monomer is preferably used in a proportion of 0.01 to 2% by weight, more preferably 0.05 to 2% by weight, based on the total amount of monomer components forming the (meth) acrylic polymer. %, More preferably 0.05 to 1.5% by weight, particularly preferably 0.1 to 1% by weight.

  As the monomer component for forming the (meth) acrylic polymer, other copolymerization monomers may be used alone or in combination as long as the object of the present invention is not impaired. Other comonomer includes, for example, a polymerizable functional group having an unsaturated double bond such as a (meth) acrylate having a C 4 alkyl group, a (meth) acryloyl group, or a vinyl group. And an aromatic ring-containing monomer having an aromatic ring. Specific examples of the (meth) acrylate having an alkyl group having less than 4 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and the like, and specific examples of the aromatic ring-containing monomer. Are phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, 2-naphthoethyl (meth) acrylate, 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate, phenoxy Examples thereof include propyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, and polystyryl (meth) acrylate.

  In addition, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; styrene sulfonic acid and allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) Sulfonic acid group-containing monomers such as acrylamide propanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; methoxyethyl (meth) acrylate, ( And (meth) acrylic acid alkoxyalkyl monomers such as ethoxyethyl (meth) acrylate.

  In addition, vinyl monomers such as vinyl acetate, vinyl propionate, styrene, α-methylstyrene, N-vinylcaprolactam; glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) Epoxy group-containing monomers such as acrylate; glycol-based acrylic ester monomers such as (meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol, (meth) acrylic acid methoxypolypropylene glycol; Acrylic ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate; Bromide group-containing monomers, amino group-containing monomers, imide group-containing monomer, N- acryloyl morpholine, may be used, such as vinyl ether monomers.

  The weight average molecular weight of the (meth) acrylic polymer of the present invention is preferably 600,000 or more, more preferably 700,000 to 2,000,000. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

  Such a (meth) acrylic polymer can be produced by appropriately selecting a known production method such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. Further, the (meth) acrylic polymer obtained may be either a random copolymer or a block copolymer.

  In solution polymerization, for example, ethyl acetate, toluene or the like is used as a polymerization solvent. As a specific example of solution polymerization, the reaction is performed under an inert gas stream such as nitrogen, and a polymerization initiator is added, and the reaction is usually performed at about 50 to 70 ° C. under reaction conditions of about 5 to 30 hours.

  The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (5-methyl-2). -Imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), 2,2 '-Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, VA-057) and other azo initiators, and persulfates such as potassium persulfate and ammonium persulfate , Di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butyl -Oxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3 , 3-tetramethylbutylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) ) Peroxides such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, peroxides and sodium bisulfite, peroxides and sodium ascorbate Redox initiators combined with Not intended to be.

  The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 with respect to 100 parts by weight of the total amount of monomer components. The amount is preferably about parts by weight, and more preferably about 0.02 to 0.5 parts by weight.

  In order to produce the (meth) acrylic polymer having the weight average molecular weight using, for example, 2,2′-azobisisobutyronitrile as the polymerization initiator, the amount of the polymerization initiator used is a monomer. The total amount of the components is preferably about 0.06 to 0.3 parts by weight, more preferably about 0.08 to 0.2 parts by weight.

  Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to

  Examples of the emulsifier used in emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer are listed. These emulsifiers may be used alone or in combination of two or more.

  Further, as reactive emulsifiers, as emulsifiers into which radical polymerizable functional groups such as propenyl groups and allyl ether groups are introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05 BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Soap SE10N (manufactured by ADEKA), and the like. Reactive emulsifiers are preferable because they are incorporated into the polymer chain after polymerization and thus have improved water resistance. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability with respect to 100 parts by weight of the total amount of monomer components.

The glass transition temperature (Tg) of the (meth) acrylic polymer is 250K or less, preferably 240K or less. The glass transition temperature is also preferably 200K or higher. When the glass transition temperature is 250 K or less, the adhesive composition has good heat resistance and excellent internal cohesive strength. Such a (meth) acrylic polymer can be adjusted by appropriately changing the monomer component and composition ratio to be used. Such glass transition temperature is, for example, by solution polymerization, using 0.06 to 0.2 part of a polymerization initiator such as azobisisobityronitrile or benzoyl peroxide, and using a polymerization solvent such as ethyl acetate. And it is obtained by making it react at 50 to 70 degreeC under nitrogen stream for 8 to 30 hours. Here, the glass transition temperature (Tg) is calculated from the following Fox equation.
1 / Tg = W1 / Tg1 + W2 / Tg2 + W3 / Tg3 +
The above-mentioned Tg1, Tg2, Tg3 and the like represent the glass transition temperatures of the individual copolymer components 1, 2, 3, etc. in absolute temperature, and W1, W2, W3 and the like represent the respective copolymer components. The weight fraction. In addition, the glass transition temperature (Tg) of the single polymer was obtained from Polymer Handbook (4th edition, John Wiley & Sons. Inc.).

  Next, a solution obtained by diluting the (meth) acrylic polymer thus obtained as it is or by adding a diluent is subjected to graft polymerization.

  Although it does not specifically limit as a diluent, Ethyl acetate or toluene is illustrated.

  Graft polymerization is carried out by reacting a (meth) acrylic polymer with a cyclic ether group-containing monomer and optionally a cyclic ether group-containing monomer and other monomers.

  Here, the cyclic ether group-containing monomer is not particularly limited, but is preferably an epoxy group-containing monomer, an oxetane group-containing monomer, or a combination of both.

  Examples of the epoxy group-containing monomer include glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, or 4-hydroxybutyl acrylate glycidyl ether. These may be used alone or in combination. Can be used.

  Examples of the oxetane group-containing monomer include 3-oxetanylmethyl (meth) acrylate, 3-methyl-3-oxetanylmethyl (meth) acrylate, 3-ethyl-3-oxetanylmethyl (meth) acrylate, and 3-butyl-3-oxetanylmethyl. (Meth) acrylate or 3-hexyl-3-oxetanylmethyl (meth) acrylate is exemplified, and these can be used alone or in combination.

  The amount of the cyclic ether group-containing monomer is preferably 2 parts by weight or more, more preferably 3 parts by weight or more with respect to 100 parts by weight of the (meth) acrylic polymer. The upper limit is not particularly limited, but is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and even more preferably 30 parts by weight or less. When the amount of the cyclic ether group-containing monomer is 2 parts by weight or more, the function of the composition as a pressure-sensitive adhesive is sufficiently exhibited. On the other hand, when the amount is 100 parts by weight or more, tackiness is reduced and initial adhesion is difficult. There is.

  It is also possible to use other monomers that co-graft with the cyclic ether group-containing monomer during the graft polymerization. Such a monomer is not particularly limited as long as it does not contain a cyclic ether group, and examples thereof include alkyl (meth) acrylates having 1 to 9 carbon atoms. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl acrylate and the like. Moreover, alicyclic (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate can also be used. These can be used alone or in combination.

  The use of other monomers that are co-grafted at the time of grafting can facilitate the curing of the adhesive. For example, in the case of photocuring, the amount of light irradiation can be reduced. The amount of curing catalyst can be reduced. This is presumably because the mobility of the graft chain is increased, or because the compatibility between the graft chain and the by-product ungrafted chain and the backbone polymer is improved.

  Such other monomers are also preferably selected from the same monomers as the main chain (trunk), that is, the components of the (meth) acrylic polymer.

  When the amount of the monomer other than the cyclic ether group-containing monomer is blended, the weight ratio of the cyclic ether group-containing monomer to the cyclic ether group-containing monomer: other monomer, preferably 90:10 to 10:90. More preferably, it is 80:20 to 20:80. If the content of other monomers is small, the effect of reducing the amount of photocuring for curing may not be sufficient, and if it is large, the peel resistance after photocuring may increase.

Graft polymerization conditions are not particularly limited, and can be carried out by methods known to those skilled in the art. In the polymerization, it is preferable to use a peroxide as a polymerization initiator.
The amount of such a polymerization initiator is 0.02 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer. When the amount of this polymerization initiator is small, it takes too much time for the graft polymerization reaction, and when it is large, many homopolymers of cyclic ether group-containing monomers are formed, which is not preferable.

  In graft polymerization, for example, in solution polymerization, a cyclic ether group-containing monomer and a viscosity-adjustable solvent are added to a solution of a (meth) acrylic polymer, followed by nitrogen substitution, and then a polymer such as dibenzoyl peroxide. Although it can carry out by adding 0.02-5 weight part of oxide type polymerization initiators and heating at 50 to 80 degreeC for 4 to 15 hours, it is not limited to this.

  The state of the obtained graft polymer (molecular weight, branch polymer branch size, etc.) can be appropriately selected depending on the reaction conditions.

  The adhesive composition for forming the pressure-sensitive adhesive tape for re-peeling of the present invention contains the graft polymer thus obtained and a photocationic polymerization initiator.

  As the photocationic polymerization initiator, any photocationic polymerization initiator known to those skilled in the art can be preferably used. More specifically, at least one selected from the group consisting of arylsulfonium hexafluorophosphate salts, triarylsulfonium salts, sulfonium hexafluorophosphate salts, and bis (alkylphenyl) iodonium hexafluorophosphates. Can be used.

  Such a cationic photopolymerization initiator may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the graft polymer. 0.15 to 4.0 parts by weight, preferably 0.2 to 3.9 parts by weight.

  Photocationic initiators become turbid when prepared in a 10% ethyl acetate solution and do not dissolve completely when mixed with a polymer. there is a possibility. Therefore, in order to make hardening more favorable, what has a good solubility in a polymer solution is preferable. A photocationic initiator that is soluble in a 10% ethyl acetate solution is particularly preferred. Examples of such a photocationic initiator include the CPI series of San Apro Co., Ltd. and the TAS series of Sumitomo Seika Co., Ltd. In addition, it is also possible to use ESACURE1064 manufactured by LAMBERTI.

  A cross-linking agent is added to the adhesive composition for forming the re-peeling pressure-sensitive adhesive tape of the present invention, if necessary. Although it does not specifically limit as a crosslinking agent, Isocyanate which is a compound which has two or more isocyanate groups (including the isocyanate reproduction | regeneration functional group which protected the isocyanate group temporarily by the blocking agent or quantification etc.) in 1 molecule. A system crosslinking agent is illustrated.

  Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

  More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2,4-tolylene diisocyanate, Aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (product name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diiso Isocyanurate of anate (product name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.), polyether polyisocyanate, polyester polyisocyanate, and adducts of these with various polyols, isocyanurate bond, burette bond And polyisocyanates polyfunctionalized with allophanate bonds. Of these, it is preferable to use an aliphatic isocyanate because of its high reaction rate.

  The above isocyanate-based crosslinking agents may be used alone or as a mixture of two or more, but the total content is based on 100 parts by weight of the graft polymer. It is preferable to contain 0.05 to 5 parts by weight of the compound crosslinking agent, more preferably 0.1 to 4 parts by weight, and even more preferably 0.2 to 3 parts by weight. . It can be appropriately contained in consideration of cohesive force and prevention of peeling in a durability test.

  Such an isocyanate-based crosslinking agent is preferably used because it can contribute to the curing reaction of the cyclic ether group in the graft chain together with the crosslinking of the main chain of the adhesive polymer.

  Moreover, you may use together an organic type crosslinking agent and a polyfunctional metal chelate as a crosslinking agent. Examples of the organic crosslinking agent include epoxy crosslinking agents (referring to compounds having two or more epoxy groups in one molecule). Examples of the epoxy-based crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, spiroglycol diglycidyl ether, and the like. These may be used alone or in combination of two or more.

  A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. can give. Examples of the atom in the organic compound that is covalently or coordinately bonded include an oxygen atom, and the organic compound includes an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, a ketone compound, and the like.

  In the present invention, it is also possible to add an oxazoline-based crosslinking agent or peroxide as a crosslinking agent.

  As the oxazoline-based crosslinking agent, those having an oxazoline group in the molecule can be used without particular limitation. The oxazoline group may be any of a 2-oxazoline group, a 3-oxazoline group, and a 4-oxazoline group. As the oxazoline-based cross-linking agent, a polymer obtained by copolymerizing an unsaturated monomer with an addition-polymerizable oxazoline is preferable, and a compound using 2-isopropenyl-2-oxazoline as the addition-polymerizable oxazoline is particularly preferable. As an example, trade name “Epocross WS-500” manufactured by Nippon Shokubai Co., Ltd. can be cited.

  The peroxide can be used as appropriate as long as it generates radical active species by heating and proceeds with crosslinking of the base polymer of the adhesive composition, but in consideration of workability and stability, It is preferable to use a peroxide having a one-minute half-life temperature of 80 ° C. to 160 ° C., and more preferable to use a peroxide having a 90 ° C. to 140 ° C.

  Examples of peroxides that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), di (4-t-butylcyclohexyl) peroxydicarbonate (1 Minute half-life temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103 0.5 ° C), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C), dilauroyl peroxide ( 1 minute half-life temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutyl Oxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (half-minute for 1 minute) Period temperature: 130.0 ° C.), t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.). Especially, since the crosslinking reaction efficiency is excellent, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4 ° C), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) and the like are preferably used.

  The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic peroxide catalog 9th edition by Nippon Oil & Fats Co., Ltd.” (May 2003) ".

  The peroxide may be used alone or as a mixture of two or more thereof, but the total content of the peroxide is 100 parts by weight of the graft polymer. 0.01 to 2 parts by weight, preferably 0.04 to 1.5 parts by weight, more preferably 0.05 to 1 part by weight. In order to adjust processability, reworkability, cross-linking stability, peelability, and the like, it is appropriately selected within this range.

  In addition, as a measuring method of the peroxide decomposition amount which remained after the reaction process, it can measure by HPLC (high performance liquid chromatography), for example.

  More specifically, for example, after about 0.2 g of the adhesive composition after reaction treatment is taken out, immersed in 10 ml of ethyl acetate, and extracted by shaking at 25 ° C. and 120 rpm for 3 hours with a shaker. Let stand at room temperature for 3 days. Next, 10 ml of acetonitrile was added, shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtration through a membrane filter (0.45 μm) was injected into the HPLC for analysis. The amount of peroxide can be set.

  Although the adhesive layer is formed by the crosslinking agent, in the formation of the adhesive layer, the addition amount of the entire crosslinking agent is adjusted, and the influence of the crosslinking treatment temperature and the crosslinking treatment time is sufficiently considered. There is a need.

  The adhesive composition for forming the re-peeling pressure-sensitive adhesive tape of the present invention may further contain an epoxy resin or an oxetane resin in order to further improve the adhesive strength and heat resistance.

  Examples of the epoxy resin include bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, cresol novolac type. Examples thereof include bifunctional epoxy resins such as trishydroxyphenylmethane type and tetraphenylolethane type and polyfunctional epoxy resins, and glycidylamine types such as hydantoin type and trisglycidyl isocyanurate type. These epoxy resins can be used alone or in combination of two or more.

  These epoxy resins are not limited, but commercially available epoxy resins can be used. Examples of such commercially available epoxy resins include, but are not limited to, for example, bisphenol type epoxy resins such as Japan Epoxy Resin Co., Ltd. jER828, jER806, etc .; alicyclic epoxy resins such as Japan Epoxy Resin Co., Ltd. YX8000, YX8034, etc. ADEKA Co., Ltd. EP4000, EP4005, etc .; polyglycidyl ethers of polyalcohols include known epoxy resins such as Nagase ChemteX Corporation Denacol EX-313, EX-512, EX-614B, EX-810, etc. .

  Examples of the oxetane resin include xylylene oxetane such as 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, 3-ethyl-3-{[3-ethyloxetane-3-yl] methoxy. } Methyl} oxetane, 3-ethylhexyloxetane, 3-ethyl-3-hydroxyoxetane, 3-ethyl-3-hydroxymethyloxetane, and other known oxetane resins can be used. These oxetane resins can be used singly or in combination of two or more.

  The oxetane resin is not limited, but a commercially available resin can be used. Examples of such commercially available oxetane resins include Aron Oxetane OXT-121, OXT221, OXT101, and OXT212 manufactured by Toa Gosei Co., Ltd., but are not limited thereto.

  Such an epoxy resin and an oxetane resin can be used for the adhesive composition which forms the adhesive tape for re-peeling of this invention combining either one or both.

  In the present invention, when the epoxy resin and / or oxetane resin is contained with respect to 100 parts by weight of the graft polymer, the total amount thereof is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably Is 100 parts by weight or less, more preferably 70 parts by weight or less. When the total amount is 5 parts by weight or more, a remarkable effect is recognized in improving the adhesive strength and heat resistance. When the total amount exceeds 100 parts by weight, it may not be sufficiently cured.

  In the present invention, when an epoxy resin is added to a graft polymer obtained by grafting a cyclic ether group-containing monomer to an acrylic polymer, a composition capable of producing a good adhesive layer in which no glue sticking out occurs before curing. Can be prepared. This is presumably because the grafted cyclic ether group is compatible with the low molecular weight epoxy resin to form a strong adhesive layer structure.

  In addition, a tackifier and a softener can be blended in the adhesive composition for forming the adhesive tape for re-peeling of the present invention. A total of 10-100 weight part of tackifiers may be used with respect to 100 weight part of graft polymers, Preferably, 20-80 weight part may be used.

Furthermore, the adhesive composition for forming the pressure-sensitive adhesive tape for re-peeling of the present invention has a silane coupling agent of 0.01 to 100 parts by weight based on 100 parts by weight of the graft polymer in order to increase the water resistance at the interface. You may mix | blend 2 weight part. Preferably, 0.02 to 1 part by weight is blended. If the amount is too large, the adhesive force to the liquid crystal cell is increased and the removability is poor. If the amount is too small, the water resistance is not improved.

  Examples of the silane coupling agent include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane. Amino group-containing silane cups such as 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine Ring agents, (meth) acryl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and isocyanate group-containing silane couplings such as 3-isocyanatopropyltriethoxysilane , And the like.

  In addition, aging or antioxidants can be added. As such aging or antioxidant, for example, antioxidants such as the hindered phenolic antioxidant Irganox series from BASF, the K-NOX series from Sort Chemical Co., Ltd., and Adeka Stub from ADEKA Corporation are used. These may be added singly or in combination.

  The adhesive composition forming the pressure-sensitive adhesive tape for re-peeling of the present invention may contain other known additives, such as powders such as colorants and pigments, dyes, and surfactants. , Plasticizer, tackifier, surface lubricant, leveling agent, softener, antioxidant, antioxidant, light stabilizer, UV absorber, polymerization inhibitor, inorganic or organic filler, metal powder, particles It can be added as appropriate depending on the application in which the shape, foil or the like is used. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

  The adhesive layer contained in the pressure-sensitive adhesive tape for re-peeling of the present invention, after applying the adhesive composition on one side of the heat-resistant film substrate, drying and removing the polymerization solvent and the like, It can be formed by photocuring. Or the adhesive tape for re-peeling excellent in heat resistance can be formed also by the system etc. which transfer the adhesive layer formed on the separator (peeling film) to a heat resistant film base material.

  As the heat resistant film substrate of the present invention, a polyethylene terephthalate film is sufficient as long as the temperature in the heating step is up to about 160 ° C., but above that, a film such as polyimide, aramid, polyethylene naphthalate, polyphenylene sulfide, etc. Is preferably used. The thickness of such a film is preferably 5 to 100 μm. The re-peeling pressure-sensitive adhesive tape of the present invention includes all forms such as a sheet form and a vertically long tape form.

  More specifically, for example, the adhesive layer is formed by applying the adhesive composition to a release-treated separator or the like, drying and removing the polymerization solvent, etc., and then crosslinking the adhesive composition. A method of transferring to a heat-resistant film substrate after forming the layer, or applying the adhesive composition on the heat-resistant film substrate from the beginning, drying and removing the polymerization solvent, etc. This can be achieved by the forming method.

  In applying the adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

  As the release-treated separator, a silicone release liner is preferably used. Examples of the constituent material of the release liner include polyethylene, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, ethylene / vinyl acetate copolymer film, polybutylene terephthalate film, polyurethane film, Examples thereof include plastic films such as polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and suitable thin leaves such as laminates thereof. A plastic film is preferably used from the viewpoint of excellent surface smoothness. Or suitable thin leaf bodies, such as a sheet | seat, a net | network, a foam, metal foil, and these laminated bodies, etc. are mention | raise | lifted.

  On such a liner or on a heat resistant film substrate, in the step of applying the adhesive composition for forming the re-peeling pressure-sensitive adhesive tape of the present invention and drying to form an adhesive layer, As a method of drying the adhesive, an appropriate method can be appropriately employed depending on the purpose. Preferably, a method of heating and drying the coating film is used. The heat drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature within the above range, an adhesive having excellent adhesive properties can be obtained.

  As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

  Moreover, an adhesive layer can be formed after forming an anchor layer on the surface of a heat resistant film base material, or performing various easy-adhesion treatments, such as a corona treatment and a plasma treatment. Moreover, you may perform an easily bonding process on the surface of an adhesive agent layer.

  Various methods are used as a method for forming the adhesive layer. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

  The thickness of the adhesive layer is not particularly limited and is, for example, about 0.5 to 100 μm. Preferably, it is 2-50 micrometers, More preferably, it is 3-25 micrometers, More preferably, it is 3-15 micrometers.

  When the adhesive layer is exposed, the adhesive layer may be protected with a sheet (separator) that has been subjected to a release treatment until practical use.

  As a constituent material of such a protective separator, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, polyester film, porous materials such as paper, cloth, nonwoven fabric, nets, foamed sheets, metal foils, and these Although an appropriate thin leaf body such as a laminate can be mentioned, a plastic film is preferably used from the viewpoint of excellent surface smoothness.

  The plastic film is not particularly limited as long as it can protect the adhesive layer, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, chloride film. Examples thereof include a vinyl copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

  The thickness of the release liner for coating or protection and the separator is usually 5 to 200 μm, preferably about 5 to 100 μm. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, when the surface of the separator is appropriately subjected to a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, the peelability from the adhesive layer can be further enhanced.

  The adhesive composition constituting the re-peeling pressure-sensitive adhesive tape of the present invention is cured by irradiation with specific light. The re-peeling pressure-sensitive adhesive tape of the present invention has a photocured adhesive layer, which ensures adhesion to an adherend or adhesion between the adherend and a member.

Although the light for irradiation is not specifically limited, Preferably, it is active energy rays, such as an ultraviolet-ray, visible light, and an electron beam. The crosslinking treatment by ultraviolet irradiation can be performed using an appropriate ultraviolet source such as a high-pressure mercury lamp, a low-pressure mercury lamp, an excimer laser, or a metal halide lamp. In this case, the irradiation amount of the ultraviolet ray can be appropriately selected according to the required degree of crosslinking, but it is usually preferable to select the ultraviolet ray within the range of 0.2 to 10 J / cm ^2. . Although the temperature at the time of irradiation is not specifically limited, Considering the heat resistance of a support body, about 140 degreeC is preferable.

  The amount of light was expressed as an integrated amount of UVA (320-390 nm), UVB (280-320 nm), UVC (250-260 nm), and UVV (395-445 nm) of UV Power Puck manufactured by Electronic Instrumentation and Technology Inc.

  By irradiating with active energy rays, the photocationic initiator is decomposed, an acid is generated, and a curing reaction with a cyclic ether group proceeds.

The gel fraction of the cured adhesive layer of the present invention is preferably 80 to 98%, and is preferably an adhesive layer having a very high cohesive force. The storage elastic modulus at 23 ° C. is preferably 9.0 × 10 ^{4 to} 1.0 × 10 ⁶ Pa, and still has tackiness, so that the adhesive composition and the pressure-sensitive adhesive sheet are excellent in heat resistance. It becomes.

Here, “after photocuring reaction” refers to a state achieved by performing light irradiation of 0.2 J / cm ² or more.

  The adhesive tape for re-peeling of the present invention is obtained in this way and used for various masking and fixing applications.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight. Unless otherwise specified, the room temperature standing conditions are all 23 ° C. and 65% RH (1 hour or 1 week).

<Measurement of weight average molecular weight>
The weight average molecular weight of the obtained (meth) acrylic polymer was measured by GPC (gel permeation chromatography). The sample was prepared by dissolving the sample in dimethylformamide to give a 0.1% by weight solution, which was allowed to stand overnight and then filtered through a 0.45 μm membrane filter.
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation, G7000H _XL + GMH _XL + GMH _XL
・ Column size: 7.8mmφ × 30cm each 90cm in total
・ Eluent: Tetrahydrofuran (concentration 0.1% by weight)
・ Flow rate: 0.8ml / min
・ Detector: Differential refractometer (RI)
-Column temperature: 40 ° C
・ Injection volume: 100 μl
・ Standard sample: Polystyrene

<Measurement of gel fraction>
The dried and crosslinked adhesive (initial weight W1) was immersed in an ethyl acetate solution and allowed to stand at room temperature for 1 week, then the insoluble matter was taken out and the dried weight (W2) was measured. I asked for it.
Gel fraction = (W2 / W1) × 100

<Measurement method of adhesive strength>
The adhesive tape for re-peeling obtained in Examples and Comparative Examples was cut to a width of 20 mm and a length of 100 mm to prepare a sample, which was pasted on a non-alkali glass plate by one reciprocating roll of 2 kg, and the condition was 23 ° C. * 50% RH After leaving for 30 minutes, the value obtained by measuring the peel adhesive strength (N / 20 mm) at a peel angle of 90 degrees and a peel speed of 300 mm / min was defined as the initial adhesive strength.
The affixed sample is heated in an oven at 260 ° C for 5 minutes and left at 23 ° C * 50% RH for 30 minutes, and then peeled off at 90 ° peel angle and peel speed 300mm / min (N / 20mm) The value measured was taken as the adhesive strength after heating. As the contamination state of the adherend, × was given if there was adhesive residue or contamination on the peeled surface, and ○ was shown if it could not be observed at all.

<Measuring method of dynamic viscoelasticity>
Apparatus: ARES manufactured by TA Instruments
Deformation mode: Torsion measurement frequency: 1Hz constant frequency
Temperature increase rate: 5 ° C / min Measurement temperature: Measured from near the glass transition temperature of the adhesive to 160 ° C Shape: Parallel plate 8.0mmφ
Sample thickness: 0.5-2mm (initial stage)
Reading storage elastic modulus (G ') at 23 ° C

Example 1
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 100 parts by weight of n-butyl acrylate, 3 parts by weight of 4-hydroxybutyl acrylate, and 2,2′-azobis as a polymerization initiator After charging 0.1 parts by weight of isobutyronitrile with 200 parts by weight of ethyl acetate, introducing nitrogen gas with gentle stirring and replacing with nitrogen for 1 hour, the liquid temperature in the flask was kept at around 60 ° C. for 10 hours. A polymerization reaction was performed to prepare an acrylic polymer solution having a weight average molecular weight of 920,000. The glass transition temperature of the obtained acrylic polymer was 231K.

The obtained acrylic polymer solution was diluted with ethyl acetate so that the solid content was 25% to prepare a diluted solution (I). In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 20 parts of 4-hydroxybutyl acrylate glycidyl ether and 20 parts of isobornyl acrylate with respect to 400 parts by weight of the diluted solution (I), Add 0.2 part of benzoyl peroxide, introduce nitrogen gas with gentle stirring and purge with nitrogen for 1 hour, then keep the liquid temperature in the flask at around 65 ° C for 4 hours, then polymerize at 70 ° C for 4 hours Reaction was performed to obtain a graft polymer solution.

Subsequently, 1 part of a triarylsulfonium salt (manufactured by Sun Apro, “CPI-200K”), an isocyanate-based crosslinking agent (NCO crosslinking agent, Mitsui) with respect to 100 parts by weight of the solid content of the graft polymer solution thus obtained. Chemicals "Takenate D110N") 0.4 parts, anti-aging agent (hindered phenol-based anti-aging agent, Ciba Japan Co., Ltd. "Irganox 1010") 1.0 part is prepared to prepare an adhesive solution did.
The above adhesive solution was applied to a 25 μm polyimide film so that the thickness of the adhesive layer after drying was 6 μm, dried at 120 ° C. for 3 minutes, and then the adhesive surface was subjected to silicone release treatment. A 38 μm polyethylene terephthalate film (MRF38, manufactured by Mitsubishi Plastics) was attached.

Subsequently, 1.2 J / cm ² light irradiation was performed on the pressure-sensitive adhesive layer surface from the PET film side with a Metahara UV lamp and aged at 50 ° C. for 2 days to obtain a re-peeling pressure-sensitive adhesive tape of the present invention.

  Except having changed the quantity and light quantity of an isocyanate type crosslinking agent and a photocationic polymerization initiator, operation similar to Example 1 was performed and re-peeling of Examples 2-10, and Comparative Examples 1-4, respectively. An adhesive tape was prepared. However, for Example 11, an acrylic polymer solution having a weight average molecular weight of 930,000 was prepared with 5 parts by weight of 4-hydroxybutyl acrylate (glass transition temperature was 235K). Furthermore, in Example 11, 50 parts of 4-hydroxybutyl acrylate glycidyl ether and isobornyl acrylate were used for preparation of the graft portion.

  Here, as a photocationic polymerization initiator, Examples 1 to 11 and Comparative Examples 1 to 4 were carried out using triarylsulfonium salts (manufactured by San Apro, “CPI-200K”) as in the Examples. For example 12, ESACURE 1064 from LAMBERTI was used.

  Table 1 shows the gel fraction, storage elastic modulus, initial adhesive force, heating adhesive force, and contamination evaluation results of the pressure-sensitive adhesive layer obtained for the samples obtained in the above Examples and Comparative Examples. In Table 1, each blending amount represents parts by weight with respect to 100 parts by weight of the graft polymer.

  In Table 1, in Comparative Example 3 marked with *, adhesive residue is observed.

Claims (12)

A heat-resistant film base material, and a pressure-sensitive adhesive tape for re-peeling comprising a cured adhesive layer on one side of the heat-resistant film base material,
A photocationic polymerization initiator 0.15-4. Is added to 100 parts by weight of a graft polymer obtained by graft-polymerizing a chain containing a cyclic ether group-containing monomer to a (meth) acrylic polymer. A pressure-sensitive adhesive tape for re-peeling, which is obtained by photo-curing an adhesive layer formed from an adhesive composition containing 0 part by weight.   The pressure-sensitive adhesive tape according to claim 1, wherein the adhesive composition further contains an isocyanate-based crosslinking agent.   The adhesive for re-peeling according to claim 1 or 2, wherein the adhesive composition further contains 5 to 100 parts by weight of an epoxy resin and / or an oxetane resin with respect to 100 parts by weight of the graft polymer. tape.   The pressure-sensitive adhesive tape for re-peeling according to any one of claims 1 to 3, wherein the gel fraction of the cured adhesive layer is 80 to 99%.   The said (meth) acrylic-type polymer contains 0.2-10 weight% of hydroxyl-containing monomers as a monomer unit with respect to this (meth) acrylic-type polymer whole quantity, Any one of Claim 1 to 4 characterized by the above-mentioned. The adhesive tape for re-peeling according to 1. The graft polymer is composed of 2 to 50 parts by weight of the cyclic ether group-containing monomer and 5 to 50 parts by weight of the other monomer to 100 parts by weight of the (meth) acrylic polymer, and 0.02 to 5 parts by weight of peroxide. The pressure-sensitive adhesive tape for re-peeling according to any one of claims 1 to 5, which is obtained by graft polymerization in the presence.   The adhesive tape for re-peeling according to any one of claims 1 to 6, wherein the photocationic polymerization initiator is a photoacid generator.   The pressure-sensitive adhesive tape for re-peeling according to claim 7, wherein the photoacid generator is dissolved without precipitation when the solvent is adjusted to a concentration of 10% using ethyl acetate. 9. The storage elastic modulus at 23 ° C. of the cured adhesive layer is 9.0 × 10 ^{4 to} 1.0 × 10 ⁶ Pa. 9. Re-peeling adhesive tape.   The refractory film substrate according to any one of claims 1 to 9, wherein the heat-resistant film substrate is selected from the group consisting of polyethylene terephthalate, polyimide, aramid, polyethylene naphthalate, and polyphenylene sulfide. Adhesive tape.   The pressure-sensitive adhesive tape for re-peeling according to any one of claims 1 to 10, wherein the adhesive layer is provided with a thickness of 0.5 to 100 µm. A method for producing a pressure-sensitive adhesive tape for re-peeling comprising a cured adhesive layer on one side of a heat-resistant film substrate,
Viscosity comprising 0.15 to 4.0 parts by weight of a photocationic polymerization initiator in 100 parts by weight of a graft polymer obtained by graft polymerization of a chain containing a cyclic ether group-containing monomer to a (meth) acrylic polymer. Applying an adhesive composition to one side of a heat-resistant film substrate to form an adhesive layer; and irradiating the adhesive layer with light and photocuring the adhesive layer;
Manufacturing method.