JP2013181127A - Polymer gel, and polymer gel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer gel and a polymer gel sheet, which have sufficient tackiness (pastability) to an adherend such as glass or metal plates, can easily be peeled off the adherend and reutilized, and have sufficient pastability and reworkability.SOLUTION: A polymer gel contains a polymer of an urethane (meth)acrylate having two or more methacryloyl groups in one molecule, and a polyol compound, and has dynamic viscoelasticity in which the value of a dynamic loss elastic modulus G" at 25°C measured in a temperature dispersion at a frequency of 1 Hz is in the range of 1.0×10to 1.0×10Pa, and the loss tangent tanδ is <0.05.

Description

  The present invention is a polymer gel that has sufficient adhesion (adhesiveness) to an adherend such as glass or a metal plate, and can be easily peeled off from the adherend and reused. And a polymer gel sheet.

  Conventionally, an adhesive substance such as an adhesive and an adhesive gel has been used in applications for attaching and fixing various materials. The performance required for adhesive materials varies depending on the application. Depending on the application of the adhesive substance, the adhesive substance exhibits adhesiveness (sticking property) only during the period when the adhesive is required, but the adhesive substance may be required to be easily peeled off after the period when the adhesive is required.

  For example, in the process of manufacturing or processing electronic parts such as semiconductors, glass chips, etc., temporary fixing of various materials using an adhesive material such as an adhesive sheet made of an adhesive substance (molded adhesive substance) Has been done. Adhesive substances used for such applications have sufficient physical properties to adhere to the adherend when fulfilling the purpose of use (manufacturing or processing), while being easily peelable from the adherend after the end of the purpose of use. Is required.

  In addition, an adhesive substance such as an adhesive or an adhesive gel can be used to transfer the product to a member (for example, a transport container or a transport tray) when transporting the minute product such as the electronic component or the glass chip. It may be used as a temporary fixing material for fixing. While the adhesive substance used as such a temporary fixing material has sufficient adhesiveness that does not peel off or move even if an impact is applied when fulfilling the purpose of use (during transportation), Physical properties that can be easily peeled off from the adherend after the end of the intended use are required.

  In recent years, adhesive substances such as adhesives and adhesive gels are being used for the purpose of enhancing the performance of industrial members. For example, by inserting an adhesive substance or adhesive material into the space part existing between the touch panel and the liquid crystal panel, adhesion and fixing between the touch panel and the liquid crystal panel, protection of the liquid crystal panel, and visibility by reducing reflection Can be improved. In this application, the adhesive substance or the adhesive material is peeled from the adherend and reworked to improve the yield during manufacturing (for example, when the positional deviation between the touch panel and the liquid crystal panel has occurred, the touch panel Or peel off the adhesive material or adhesive material from the adherend during use for repair or repair (for example, peel the touch panel from the liquid crystal panel, When repairing or repairing the LCD panel is necessary, or when recycling various parts after the adhesive substance or adhesive material has been used for a long time, the adhesive substance or adhesive material Peel from the adherend. Therefore, an adhesive material such as an adhesive and an adhesive material such as an adhesive sheet that can be easily peeled off from an adherend are required.

  However, conventional adhesive materials or adhesive materials such as adhesives and adhesive gels have a strong adhesive force, so that they adhere sufficiently to the adherend. It was difficult to remove from the body. Therefore, if the adhesive strength of adhesive substances such as adhesives and adhesive gels is lowered to enable re-peeling, the adherence to the adherend will be insufficient, and the adherend will peel off during work and transport. Therefore, it could not be used as a fixing material.

  For example, in Patent Document 1, as a temporary fixing application member, a radical generator, a thermoplastic resin, and a urethane (meth) acrylate having a radical polymerizable bifunctional or higher functionality and a weight average molecular weight of 3000 or more and 30000 or less. An adhesive composition is disclosed. Although this adhesive composition has sufficient adhesiveness (sticking property), it could not be peeled off from the adherend and reused. Patent Document 2 discloses a pressure-sensitive adhesive material (thermally peelable double-sided pressure-sensitive adhesive sheet) having a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres. This pressure-sensitive adhesive material is such that heat-expandable microspheres are heated and foamed by heating, and the peelability is obtained by reducing the contact area to the adherend. However, once heated, the adhesive is destroyed by foaming and cannot be reused.

  As described above, the conventional adhesive substances and adhesive materials are not sufficiently provided with adhesiveness to an adherend and reworkability that can be peeled off and reused.

JP 2011-168786 A JP 2008-266456 A

  Therefore, the present invention has been made in view of the above situation, and the object thereof is to have sufficient adhesion (adhesiveness) to an adherend such as glass or a metal plate, and the adherence thereof. An object of the present invention is to provide a polymer gel and a polymer gel sheet having sufficient adhesiveness and reworkability that can be easily peeled off from the body and reused.

In order to solve the above problems, the polymer gel of the present invention contains a polymer of urethane (meth) acrylate having two or more (meth) acryloyl groups in one molecule and a polyol compound, and has a frequency of 1 Hz. The value of the dynamic loss modulus G ″ at 25 ° C. measured by temperature dispersion is in the range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa, and the loss tangent tan δ is less than 0.05. In this specification, (meth) acryloyl means acryloyl or methacryloyl, (meth) acrylate means acrylate or methacrylate, and (meth) acryl is acrylic. Or methacryl.

In the polymer gel of the present invention, the value of the dynamic loss elastic modulus G ″ at 25 ° C. measured by temperature dispersion at a frequency of 1 Hz is in the range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa. And, since it has dynamic viscoelasticity with a loss tangent tan δ less than 0.05, it has sufficient adhesiveness (adhesiveness) to an adherend such as glass or a metal plate, and The polymer gel of the present invention can be easily peeled off from the adherend, that is, the polymer gel of the present invention has sufficient adhesiveness to an adherend, particularly, an adherend made of metal or glass. On the other hand, it has excellent reworkability that can be easily peeled off from the adherend and reused.

  Moreover, in order to solve the said subject, the polymer gel sheet of this invention uses the polymer gel of the said invention, It is characterized by the above-mentioned.

  Since the polymer gel sheet of the present invention is formed using the polymer gel of the present invention, the polymer gel sheet has sufficient adhesion (adhesiveness) to the adherend as the polymer gel of the present invention. In addition, it can be easily peeled off from the adherend and reused.

  The polymer gel and polymer gel sheet of the present invention have sufficient adhesiveness (adhesiveness) to an adherend such as glass or a metal plate, and are easily peeled off from the adherend and reused. It has sufficient stickability and reworkability.

FIG. 1 is an explanatory diagram for explaining a method for evaluating the peelability of the polymer gel of the present invention.

  The present invention is described in detail below.

[Polymer gel]
The polymer gel of the present invention includes a polymer of urethane (meth) acrylate (A) having two or more (meth) acryloyl groups in one molecule and a polyol compound (B), and a temperature dispersion at a frequency of 1 Hz. The dynamic loss elastic modulus G ″ measured at 25 ° C. in the range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa and the loss tangent tan δ is less than 0.05. It has viscoelasticity.

  Here, the polymer gel has a form in which a polymer skeleton called a polymer matrix encloses a liquid component, and the polymer gel of the present invention has two or more (meth) acryloyl in one molecule. It is considered that the polymer matrix (polymer) formed by the reaction of the urethane (meth) acrylate (A) having a group contains a polyol as a liquid component.

  That is, the urethane (meth) acrylate (A) having two or more (meth) acryloyl groups in one molecule has a role of forming the skeleton of the polymer gel of the present invention.

  The urethane (meth) acrylate (A) is a compound having a (meth) acryloyl group and a urethane bond (—NHCOO—). Such a urethane (meth) acrylate (A) is obtained by, for example, reacting a polyisocyanate, a (meth) acrylate having a hydroxy group, and, if necessary, a polyol with a catalyst such as tin or amine. Is obtained.

  Examples of polyisocyanates for obtaining the urethane (meth) acrylate (A) include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane. -4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, ω, ω'-diisocyanate dimethylcyclohexane and other alicyclic diisocyanates; 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate , Tolidine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene-1,5-diisocyanate, etc. Such as aromatic-based diisocyanates, and the like.

  The (meth) acrylate having a hydroxy group for obtaining the urethane (meth) acrylate (A) is not particularly limited as long as it is a compound having a hydroxy group and a (meth) acryloyl group in one molecule. Things can be used. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxycyclooctyl (meta ) Acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, hydroxyalkyl acrylate such as pentaerythritol triacrylate, hydroxy group-containing acrylamide such as N-methylol (meth) acrylamide, polyethylene glycol (meth) acrylate, polypropylene glycol Examples include (meth) acrylates and α-hydroxyalkyl acrylates such as α-hydroxymethyl acrylate.

  The polyols for obtaining the urethane (meth) acrylate (A) are not particularly limited as long as they are compounds having two or more hydroxy groups, and known ones can be used. Specifically, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, hexanediol, octanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl- Various known glycols such as 2-butyl-1,3-propanediol, 1,4-cyclohexanedimethanol, ethylene glycol of bisphenol A, or propylene glycol adducts; polyfunctional polyols such as trimethylolpropane and glycerin; n -Butyl glycidyl ether, etc. Alkyl glycidyl ethers; monocarboxylic acid glycidyl esters such as versatic acid diglycidyl ester and the like.

  In the polymer gel of the present invention, the urethane (meth) acrylate (A) is preferably an aliphatic urethane (meth) acrylate obtained using an aliphatic isocyanate. When the aliphatic urethane (meth) acrylate is used as the urethane (meth) acrylate (A), a polymer gel having excellent transparency and excellent temporal stability (not easily yellowed in a high temperature environment) can be obtained. .

  As the urethane (meth) acrylate (A), for example, the following commercially available products can be used. A commercial item may be used independently and may be used in combination of 2 or more types. Examples of commercially available products include “EBECRYL (registered trademark)” series EB230, EB270, EB4858, EB5129, EB8210, EB8301, EB8402, EB8804, EB8807, EB9260, EB9270, EB8301, and EB8701 manufactured by Daicel Cytec Corporation. Aliphatic urethane (meth) acrylates and aromatic urethane (meth) acrylates such as EB210 and EB220; “purple light (registered trademark)” series manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UV1700B, UV6300B, UV7650B, UV6630B, UV2000B, UV3000B, UV3300B, etc .; UN1255, UN6060PTM, UN6060P, UN9000PEP, UN, manufactured by Negami Kogyo Co., Ltd. 200A, UN3320HA, UN3320HC, UN3320HS, UN901T, etc .; CN929, CN962, CN963, CN964, CN965 and other aliphatic urethane (meth) acrylates made by Sartomer, CN971, CN972, CN975, CN978, etc. Urethane (meth) acrylate; “Aronix (registered trademark)” series M-1100, M-1200, etc. manufactured by Toa Gosei Co., Ltd .; U-4HA, U-6HA, U-6LPA, etc., manufactured by Shin-Nakamura Chemical Co., Ltd. Is mentioned.

  The polymer of urethane (meth) acrylate (A) contained in the polymer gel of the present invention is not particularly limited as long as it has a structural unit derived from urethane (meth) acrylate (A). ) A polymer having a structural unit other than the structural unit derived from the acrylate (A) may be used. For example, the polymer of urethane (meth) acrylate (A) contained in the polymer gel of the present invention is adjusted to the urethane (meth) acrylate (A), the adhesive force, strength and hardness, and a polyol compound (described later) For the purpose of improving compatibility with B), a polymer of a monomer mixture obtained by appropriately mixing other vinyl monomers other than urethane (meth) acrylate (A) may be used.

  As said other vinyl-type monomer, what has one or more carbon-carbon double bonds which have polymerizability in a molecule | numerator should just be mentioned, for example, (meth) acrylic acid, styrene, p-methylstyrene, Examples thereof include those having a polymerizable alkenyl group (broadly defined vinyl group) such as α-methylstyrene and vinyl acetate. Each of these other vinyl monomers may be used alone or in combination of two or more.

  The polymer gel of the present invention contains a polyol compound (B). The polyol compound (B) has a role of imparting flexibility to the polymer gel of the present invention.

  Examples of the polyol compound (B) include polyether diols such as polycarbonate diol, polycaptolactone diol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, 1,4-butanediol, 1, A hydroxyl group is formed in one molecule such as polyester diol which is a copolymer of an aliphatic diol compound such as 6-hexanediol and 1,9-nonanediol and an aliphatic dicarboxylic acid compound such as succinic acid, glutaric acid and adipic acid. Diols having two; polyols having three or more hydroxyl groups in one molecule such as trimethylolpropane, (poly) glycerin, pentaerythritol, sorbitol; ethylene oxide (EO), propylene with respect to these polyols EO-modified trimethylolpropane, PO-modified trimethylolpropane, EO-modified (poly) glycerin, PO-modified (poly) glycerin, EO-modified pentaerythritol obtained by addition polymerization of cyclic ether compounds such as xoxide (PO) and butylene oxide And polyether polyols such as PO-modified pentaerythritol, EO-modified sorbitol, and PO-modified sorbitol.

  The polyol compound (B) in the polymer gel of the present invention is more preferably a liquid oligomer having a weight average molecular weight (Mw) of 100 to 5000, or a liquid which is liquid at normal temperature (25 ° C.). When the polyol compound (B) is in a solid state, the polyol compound (B) is solidified during the production of a polymer gel, making it difficult to prepare a liquid, and sufficient adhesion and flexibility in the resulting polymer gel. Sexuality may not be provided.

  The weight average molecular weight of the above-described polyol compound (B) means a weight average molecular weight in terms of polystyrene (PS). The weight average molecular weight of the polyol compound (B) can be measured using gel permeation chromatography (GPC).

  The polyol compound (B) in the polymer gel of the present invention is preferably the above-mentioned polyether polyol, and is preferably a polyether-added (poly) glycerin such as EO-modified (poly) glycerin or PO-modified (poly) glycerin. Further preferred. Polyether-added (poly) glycerin has a high steric hindrance and poor crystallinity because the hydroxyl group of (poly) glycerin is modified with a polyol and has a branched structure. For this reason, the polyether-added (poly) glycerin is liquid at room temperature even if it has a high molecular weight as compared with a polyol compound having a linear structure, and is more preferably used as a solvent component or a plasticizer of a polymer gel. Is possible. In addition, polyether-added (poly) glycerin hardly causes bleed-out of liquid components when a polymer gel is formed. Specific examples of the polyether-added (poly) glycerin include, for example, polyoxyethylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxyethylene polyoxypropylene glyceryl ether, polyoxyethylene polyoxypropylene diglyceryl ether, polyoxypropylene Examples thereof include glyceryl ether and polyoxypropylene diglyceryl ether. Examples of commercially available polyether-added (poly) glycerin include SC-E450, SC-E750, SC-E1000, SC-P400, SC-P1000, SC-P1200, and SC-P1600 manufactured by Sakamoto Pharmaceutical Co., Ltd. Etc. In the present specification, (poly) glycerin means glycerin or (poly) glycerin.

  The content of the polyol compound (B) in the polymer gel of the present invention is preferably in the range of 5 to 70% by weight, and more preferably in the range of 20 to 60% by weight. When the content rate of the said polyol compound (B) is less than 5 weight%, the softness | flexibility of a polymer gel cannot be obtained and the sticking property to a to-be-adhered body may not fully be obtained. On the other hand, when the content of the polyol compound (B) is more than 70% by weight, the polyol may bleed out from the surface of the polymer gel, and the adhesiveness becomes too high to obtain reworkability. There is a fear.

  Moreover, the polymer gel of this invention may contain various additives as needed. As said additive, antioxidant, a stabilizer, a pH adjuster, a fragrance | flavor, a coloring agent, dye, etc. are mentioned, for example. Moreover, the polymer gel of the present invention may contain a polymerization initiator described later used in the production of the polymer gel.

The polymer gel of the present invention has a dynamic loss elastic modulus G ″ at 25 ° C. measured by temperature dispersion at a frequency of 1 Hz within a range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa, and It has dynamic viscoelasticity with a loss tangent tan δ less than 0.05. When the dynamic loss elastic modulus G ″ and the loss tangent tan δ are out of the above ranges, both sufficient pastability and reworkability should be ensured. I can't. For example, a polymer gel having a dynamic loss elastic modulus G ″ of less than 1.0 × 10 ³ Pa has stickability but cannot be easily peeled off from an adherend (poor peelability), On the other hand, a polymer gel having a dynamic loss elastic modulus G ″ exceeding 1.0 × 10 ⁴ Pa does not have sufficient stickability. In addition, the polymer gel having a dynamic loss elastic modulus G ″ in the range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa but having a loss tangent tan δ of 0.05 or more has stickability. However, it does not have sufficient elasticity, has poor peelability, and does not have reworkability.

The polymer gel of the present invention has a value of dynamic storage elastic modulus G ′ at 25 ° C. measured by temperature dispersion at a frequency of 1 Hz within the range of 5.0 × 10 ^{4 to} 5.0 × 10 ⁵ Pa. It is preferable that Among the polymer gels of the present invention, the polymer gel having the dynamic storage elastic modulus G ′ in the range of 5.0 × 10 ⁴ to 5.0 × 10 ⁵ Pa has both stickability and reworkability. Especially excellent.

  A method for measuring the dynamic viscoelasticity (dynamic storage elastic modulus G ′, dynamic loss elastic modulus G ″, loss tangent tan δ) will be described in the section of Examples described later.

[Method for producing polymer gel]
The method for producing the polymer gel of the present invention is not particularly limited, and the polymer gel sheet can be produced by a known method. For example, using a composition for a polymer gel containing the urethane (meth) acrylate (A), the polyol compound (B), and a polymerization initiator, general radical polymerization (for example, radical polymerization by redox reaction, activity) The polymer gel of the present invention can be produced by a production method in which the urethane (meth) acrylate (A) in the polymer gel composition is polymerized by performing radical polymerization by energy ray irradiation or the like.

  The polymerization initiator is not particularly limited, and examples thereof include a thermal polymerization initiator and a photopolymerization initiator.

  The thermal polymerization initiator is not particularly limited as long as it is cleaved by heat and generates radicals. For example, organic peroxides such as benzoyl peroxide; azobiscyanovaleric acid, azobisisobutyronitrile, etc. Azo polymerization initiators; persulfates such as potassium persulfate and ammonium persulfate; and azo compounds such as 2,2-azobisamidinopropane dihydrochloride. If necessary, a redox initiator comprising a reducing agent such as ferrous sulfate or pyrosulfite and a peroxide such as hydrogen peroxide or sodium thiosulfate may be used in combination with the thermal polymerization initiator.

  The photopolymerization initiator is not particularly limited as long as it is cleaved with ultraviolet rays or visible rays to generate radicals. For example, α-hydroxyketone, α-aminoketone, benzylmethyl ketal, bisacylphosphine oxide More specifically, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (product name: Darocur (registered trademark) 1173, BASF Japan Ltd. (former: Ciba 1-hydroxy-cyclohexyl-phenyl-ketone (product name: IRUGACURE (registered trademark) 184, manufactured by BASF Japan Ltd.), 1- [4- (2-hydroxyethoxy) -phenyl] -2-Hydroxy-2-methyl-propan-1-one (Product name: IR UGACURE (registered trademark) 2959, manufactured by BASF Japan Ltd.), 2-methyl-1-[(methylthio) phenyl] -2-morpholinopropan-1-one (product name: IRUGACURE (registered trademark) 907, BASF Japan Ltd.) Company-made), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (product name: IRUGACURE (registered trademark) 369, manufactured by BASF Japan Ltd.), and the like. These photoinitiators may be used independently and 2 or more types may be used together.

  The content of the polymerization initiator in the polymer gel composition is preferably 0.01% by weight to 1.0% by weight. When the content of the polymerization initiator in the polymer gel composition is 0.01% by weight or more, the polymerization reaction proceeds sufficiently, and the polymerizable monomer remaining in the polymer gel obtained by the polymerization reaction The amount of the body (for example, urethane (meth) acrylate (A)) can be reduced. Further, when the content of the polymerization initiator in the polymer gel composition is less than 1.0% by weight, discoloration (yellowing) due to the polymerization initiator remaining in the polymer gel obtained by the polymerization reaction And odor can be prevented.

  Since the polymer gel of the present invention is a gel obtained by polymerizing a liquid polymer gel composition (compound solution), it can be appropriately molded according to the intended use. For example, the polymer gel composition (mixed solution) is poured into a mold having an arbitrary shape, and then the urethane (meth) acrylate (A) in the polymer gel composition is polymerized. A gel product can be produced. When the polymer gel is molded into a sheet or film, the urethane (meth) acrylate (A) in the polymer gel composition is preferably polymerized by irradiation with active energy rays. In addition, the said active energy ray means what has energy quantum in electromagnetic waves or a charged particle beam, ie, active light, such as an ultraviolet-ray and visible light; Radiation, such as an electron beam and a gamma ray. The active energy ray used for producing the polymer gel of the present invention is preferably ultraviolet rays, and examples thereof include a radiation source such as a high-pressure mercury lamp, a halogen lamp, a xenon lamp, and a metal halide lamp. It is preferable to use a photopolymerization initiator in the polymerization system using ultraviolet rays.

It if by ultraviolet irradiation to polymerize the urethane (meth) acrylate (A) of the polymer gel composition for the integrated irradiation dose of ultraviolet light is in the range of 1000mJ / cm ² ~10000mJ / cm ² preferably, and more preferably in a range of ^{2000mJ / cm 2 ~7000mJ / cm 2} .

[Use of polymer gel]
The polymer gel of the present invention can be used in various applications that require sticking to an adherend and reworkability.

  For example, the polymer gel of the present invention can be used as a temporary fixing material for temporarily fixing (temporarily fixing) a metal or glass member to another metal or glass member. As a specific example, it can be used as a temporary fixing material for temporarily fixing various members in a process of manufacturing or processing an electronic component such as a semiconductor or a glass chip. In addition, the polymer gel of the present invention temporarily transfers the product to a transport member (for example, a transport container or a transport tray) when transporting a minute product (for example, the electronic component or glass chip). It can also be used as a temporary fixing material for fixing. Furthermore, the polymer gel of the present invention is an optical device composed of a plurality of panels such as a touch panel integrated liquid crystal display device composed of a touch panel and a liquid crystal panel. It can also be used as an adhesive for bonding a touch panel and a liquid crystal panel.

[Polymer gel sheet]
The polymer gel sheet of the present invention is formed using the polymer gel of the present invention. The polymer gel sheet of the present invention can be obtained by molding the polymer gel of the present invention into a sheet shape. For example, the polymer gel sheet of the present invention is preferably obtained by molding a polymer gel into a sheet shape having a thickness of 0.01 mm to 2.0 mm. In such a polymer gel sheet, it is preferable that a protective film for protecting the surface of the polymer gel is provided on at least one surface of the polymer gel.

  In the polymer gel sheet, when a protective film provided on one surface of the polymer gel is used as a separator, it is preferable that a release treatment is performed on both surfaces of the protective film. In this case, you may make a difference in the peeling strength of the front and back. Further, when the protective film is used as a support, by performing a release treatment on the surface of the protective film opposite to the surface in contact with the polymer gel, the surface of the protective film opposite to the surface in contact with the polymer gel is used. A function as a separator can be imparted to the surface.

  In the polymer gel sheet, protective films may be provided on both sides of the polymer gel. The protective film on both sides of the polymer gel may be peeled off in the middle of the process as a separator and replaced with another film, etc., attached to the final product as a support or mount, and used as it is for end users. It may be peeled off immediately before use by the end user.

  The protective film used as a support is not particularly limited as long as it is a resin film, a nonwoven fabric, or a woven fabric that can reinforce the polymer gel and retain the sheet-like form. Examples of the resin film that can be used as the support include polyester, polyolefin, polystyrene, and polyurethane.

  The protective film when used as a separator is not particularly limited as long as it is a resin or paper that can be molded into a film. For example, a resin film made of polyester, polyolefin, polystyrene, or the like; paper; paper laminated with a resin film, or the like Can be mentioned. In addition, the protective film used as a separator is preferably subjected to a release treatment on at least the surface in contact with the polymer gel, and if necessary, a release treatment is applied to both sides of the protective film. May be. When releasing treatment on both sides, a difference may be made in the peel strength between the front and back sides. The method for the release treatment is not particularly limited, and examples thereof include a coating method with a release agent such as a fluorine-based resin, a silicone-based resin, and a long-chain alkyl group-containing carbamate. A baking type silicone coating method for curing reaction is preferable.

  When a protective film on both sides of a polymer gel is used as a separator, biaxially stretched PET film, OPP film, or paper laminated with polyolefin should be used for one protective film (hereinafter referred to as base film). Is preferred. Moreover, when the protective film of both surfaces of a polymer gel is used as a separator, you may use an optical filter for a base film. In addition, when protective films on both sides of the polymer gel are used as separators, the protective film disposed on the opposite side of the base film (hereinafter referred to as the top film) is optimal for the product form of the polymer gel sheet. The material is selected. For example, when the polymer gel sheet is formed into a strip shape, the top film is not particularly limited as long as it is a resin or paper that can be molded into a film shape, but the top film and the base film may be subjected to a release treatment. preferable.

[Method for producing polymer gel sheet]
The method for producing the polymer gel sheet of the present invention is not particularly limited, and the polymer gel sheet can be produced by the following method.

  For example, in the state in which the polymer gel composition (formulation liquid) is poured between two protective films made of a resin film and kept at a constant thickness, the urethane ( A polymer gel sheet having a thickness of about 0.5 to 2.0 mm can be produced by polymerizing the (meth) acrylate (A).

  Further, a polymer gel composition (formulation liquid) is thinly coated on one protective film, and the urethane (meth) acrylate (A) in the polymer gel composition is polymerized by the above polymerization method. Thus, a polymer gel sheet having a thickness of about 0.01 to 0.5 mm can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

[Example 1]
EB270 as urethane (meth) acrylate (A) (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) and 30 parts by weight of polyoxypropylene (poly) as a polyol compound (B) ) 69.5 parts by weight of glyceryl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd., trade name: SC-P1600, Mw = 1600) and 2-hydroxy-2-methyl-1-phenyl-propane-1 as a photopolymerization initiator -ON (BASF Japan Co., Ltd., trade name: Darocur (registered trademark) 1173, (abbreviation: DR1173)) 0.5 parts by weight are mixed and stirred to give a slightly yellow transparent liquid mixture (for polymer gel) Composition) was obtained.

Next, the obtained compounded liquid was dripped on the silicone-coated PET film as a protective film. On top of that, a PET film coated with silicone as a protective film was also covered, and the blended solution was spread evenly and fixed to a thickness of 0.3 mm. A metal halide lamp was used to irradiate ultraviolet rays having an energy amount of 7000 mJ / cm ² to obtain a sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm.

[Example 2]
The blending amount of EB270 (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) is 40 parts by weight, and polyoxypropylene (poly) glyceryl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd., trade name) : SC-P1600, Mw = 1600), except that the amount was 59.5 parts by weight, in the same manner as in Example 1, a sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained. .

Example 3
The blending amount of EB270 (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) is 60 parts by weight, and polyoxypropylene (poly) glyceryl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd., trade name) : SC-P1600, Mw = 1600), except that the amount was 39.5 parts by weight, a sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained in the same manner as in Example 1. .

Example 4
The blending amount of EB270 (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) is 75 parts by weight, and polyoxypropylene (poly) glyceryl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd., trade name) : SC-P1600, Mw = 1600) except that the blending amount was 24.5 parts by weight, in the same manner as in Example 1, a sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained. .

Example 5
The blending amount of EB270 (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) is 94.5 parts by weight, and polyoxypropylene (poly) glyceryl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd., A sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained in the same manner as in Example 1 except that the blending amount of product name: SC-P1600, Mw = 1600) was changed to 5 parts by weight. .

Example 6
As urethane (meth) acrylate (A), EB270 (manufactured by Daicel-Cytec Corporation, trade name: EBECRYL (registered trademark) 270, Mw = 1500) instead of 30 parts by weight EB230 (manufactured by Daicel-Cytec Corporation, trade name: Using 60 parts by weight of EBECRYL (registered trademark) 230, Mw = 5000), the amount of polyoxypropylene (poly) glyceryl ether (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., trade name: SC-P1600, Mw = 1600) is 39. A sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained in the same manner as in Example 1 except that the amount was changed to 0.5 parts by weight.

Example 7
The blending amount of EB270 (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) is 60 parts by weight, and the polyoxypropylene (poly) glyceryl ether (Sakamoto Pharmaceutical Co., Ltd.) is used as the polyol compound (B). Co., Ltd., trade name: SCP-1600, Mw = 1600) In place of 69.5 parts by weight, polyoxyethylene polyglyceryl ether (Sakamoto Pharmaceutical Co., Ltd., trade name: SC-E750, Mw = 750) 39.5 A sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained in the same manner as in Example 1 except that parts by weight were used.

[Comparative Example 1]
Without using polyoxypropylene (poly) glyceryl ether (Sakamoto Yakuhin Kogyo Co., Ltd., trade name: SC-P1600, Mw = 1600), EB270 (Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270) , Mw = 1500) A sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm was obtained in the same manner as in Example 1 except that the blending amount was 99.5 parts by weight.

[Comparative Example 2]
The blending amount of EB270 (manufactured by Daicel Cytec Co., Ltd., trade name: EBECRYL (registered trademark) 270, Mw = 1500) is 25 parts by weight, and the polyoxypropylene (poly) glyceryl ether (Sakamoto Pharmaceutical Co., Ltd.) is used as the polyol compound (B). Co., Ltd., trade name: SC-P1600, Mw = 1600) In place of 69.5 parts by weight, polyoxyethylene polyglyceryl ether (Sakamoto Pharmaceutical Co., Ltd., trade name: SC-E750, Mw = 750) 74.5 An attempt was made to obtain a sheet-like polymer gel having a thickness of 0.3 mm (polymer gel sheet) in the same manner as in Example 1 except that parts by weight were used. The polymer gel could not be obtained.

[Comparative Example 3]
60 parts by weight of isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: IBXA) and liquid polymer (manufactured by Toa Gosei Co., Ltd., trade name: ARUFUON (registered trademark) UP1010, Mw = 1700, Tg = −31) ° C) 39.3 parts by weight, 1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light acrylate 1,9-NDA) and 2 parts by weight as a photopolymerization initiator Hydroxy-2-methyl-1-phenyl-propan-1-one (BASF Japan Ltd., trade name: Darocur (registered trademark) 1173, (abbreviation: DR1173)) 0.5 part by weight is mixed and stirred. Thus, a mixed solution was obtained.

Next, the obtained compounded solution was dropped on a silicone-coated PET film. On top of that, a PET film coated with silicone was also covered, and the blended solution was spread evenly and fixed to a thickness of 0.3 mm. A metal halide lamp was used to irradiate ultraviolet rays having an energy amount of 7000 mJ / cm ² to obtain a sheet-like polymer gel (polymer gel sheet) having a thickness of 0.3 mm.

[Method for measuring dynamic viscoelastic properties]
A polymer gel (polymer gel sheet) is punched into a circular shape having a diameter of 8 mm, and a test piece is obtained by laminating a plurality of circular polymer gel sheets obtained so as to have a thickness of 1 mm.

Using a dynamic viscoelastic device (manufactured by Anton Paar, PHYSICA MCR301)
The dynamic viscoelastic property (dynamic storage elasticity) of the test piece at each temperature under the conditions that the frequency of vibration applied to the test piece is 1 Hz, the heating rate is 5 ° C./min, and the measurement temperature range is −70 ° C. to 200 ° C. Measurement of modulus G ′, dynamic loss elastic modulus G ″, loss tangent tan δ) (that is, temperature dispersion measurement) was performed.

  The values of the dynamic storage elastic modulus G ′, the dynamic loss elastic modulus G ″, and the loss tangent tan δ at 25 ° C. obtained by measuring the dynamic viscoelastic properties of Examples 1 to 7 and Comparative Examples 1 and 3 are as follows. It is shown in Table 1 below.

[Attachment evaluation method]
In the evaluation of sticking property, the PET film on one surface of the polymer gel sheet is peeled off and the polymer gel sheet is attached to a stainless steel plate (100 mm × 100 mm, thickness 1.5 mm), and then the other side of the polymer gel sheet is used. The PET film on the surface was peeled off, and a test piece was prepared by placing a 5 mm square glass chip on the peeled surface. In this test piece, the surface on which the glass chip is placed is referred to as the front surface, and the surface opposite to the front surface is referred to as the back surface.

  Using the test piece, the following two items (dropability and dropability (impact application)) were evaluated.

(1) Fallability When the test piece is turned upside down so that the surface on which the glass chip is placed faces down, it is observed whether the glass chip is dropped, and the case where it does not fall is The case of falling was evaluated as “×”.

(2) Dropability (impact application)
The test piece is turned upside down so that the surface on which the glass chip is placed faces down, and a steel ball of 500 g to 150 mm in height (chrome ball (SUJ-2), diameter 50 mm) toward the back surface of the test piece When the ball was dropped and a ball impact was applied to the back surface of the test piece, it was observed whether or not the glass chip dropped. The case where it did not drop was evaluated as “◯”, and the case where it dropped was evaluated as “x”.

  The evaluation results of the sticking properties for Examples 1 to 7 and Comparative Examples 1 and 3 are shown in Table 1 below.

[Evaluation method of peelability]
As shown in FIG. 1A, after peeling the PET film on one surface of the polymer gel sheet 1 and attaching the polymer gel sheet 1 to a stainless steel plate 2 (100 mm × 100 mm, thickness 1.5 mm), The PET film on the other surface of the polymer gel sheet 1 was peeled off, and a 5 mm square glass chip 3 was placed on the peeled surface. Thereafter, when the glass chip 3 is lifted in the vertical direction using tweezers 4 (industrial tweezers manufactured by Kowa Tweezers Co., Ltd., grade: K-3GG 125 m / m), the glass chips 3 are damaged. No, when the glass chip 3 was peeled from the polymer gel sheet 1 (see FIG. 1B), the glass chip 3 was peeled off from the polymer gel sheet 1 but the glass chip 3 was peeled off. Or the case where the stainless steel plate 2 was lifted without peeling off the glass chip 3 from the polymer gel sheet 1 (see FIG. 1C) was evaluated as “x”.

  The evaluation results of peelability for Examples 1 to 7 and Comparative Examples 1 and 3 are shown in Table 1 below.

[Evaluation method for reworkability]
The evaluation of the sticking property (dropability, dropability (impact) imparting) and peelability evaluation were repeated 5 cycles using the same test piece (dropability → fallability (impact imparting) → peelability test 1) In the evaluation of all sticking properties and peelability, the case of “◯” was evaluated as “◯”, and the case of “x” in any evaluation was evaluated as “x”.

  In Table 1, the compounding quantity (weight part) of the various components contained in the compounding liquid used for manufacture of the polymer gel of Examples 1-7 and Comparative Examples 1-3, Examples 1-7, and Comparative Example 1 And 3 show the evaluation results of the polymer gels (dynamic viscoelasticity measurement results, stickiness evaluation results, peelability evaluation results, and reworkability evaluation results). In the polymer gels of Examples 1 to 7 and Comparative Example 1, the content of the polyol compound (B) in the polymer gel is the same as the compounded liquid (composition for polymer gel) used in the production of the polymer gel. ) In accordance with the content of the polyol compound (B).

  From the results shown in Table 1, it was confirmed that the polymer gels (polymer gel sheets) of Examples 1 to 7 have both sufficient adhesiveness to the adherend and reworkability.

Specifically, Examples 1 to 7 including a polymer of urethane (meth) acrylate (A) and a polyol compound (B), and the content of the polyol compound (B) is in the range of 5 to 70 parts by weight. In the polymer gel, the dynamic loss elastic modulus G ″ is in the range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa (more specifically, 2.3 × 10 ^{3 to} 9.8 × 10 ³ Pa), and the loss tangent tan δ is less than 0.05 (more specifically, in the range of 0.02 to 0.04), and has dynamic viscoelasticity. It was confirmed that the film was sufficiently adhered to the body (stainless steel plate and glass chip) and could be easily peeled off from the adherend and was reusable. dynamic storage modulus G 'is a polymer ^{gel, 5.0 × 10 4 ~5.0 × 10} 5 in the range of Pa (more specifically, 6 It was observed in ⁴ × 10 4 ~5.0 × range of 10 ⁵ Pa).

  On the other hand, although the polymer gel of the comparative example 1 which contains the polymer of urethane (meth) acrylate (A) but does not contain a polyol compound (B) is compared with the polymer gel of Examples 1-7, it is a dynamic loss. Since the elastic modulus G ″ is high and hard, it was confirmed that it was difficult to stick to the adherend and poor in stickability. Further, a polymer of urethane (meth) acrylate (A) and a polyol compound The polymer gel of Comparative Example 3 which does not contain (B) and contains other components has a dynamic storage elastic modulus G ′ and a dynamic loss elastic modulus G ″ equivalent to those of Examples 1 to 7, Although it has sufficient adhesiveness to the adherend, it was confirmed that the loss tangent tan δ was high and it did not have sufficient elasticity, so it was difficult to peel off from the adherend and there was no reworkability.

  The polymer gel and polymer gel sheet of the present invention are a temporary fixing material for temporarily fixing (temporarily fixing) various members in a process of manufacturing or processing an electronic component such as a semiconductor or a glass chip: a touch panel and a liquid crystal. In an optical device composed of a plurality of panels, such as a touch panel integrated liquid crystal display device composed of a panel and the like, an adhesive material for bonding a plurality of panels together (in this application, generally at the time of manufacture or manufacture It can be used as a temporary fixing material for fixing the product when a minute product (for example, a minute electronic component or a glass chip) is conveyed.

Claims (9)

A urethane (meth) acrylate polymer having two or more (meth) acryloyl groups in one molecule;
A polyol compound,
The value of the dynamic loss elastic modulus G ″ measured at 25 ° C. with a frequency dispersion of 1 Hz is in the range of 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa, and the loss tangent tan δ is 0.00. A polymer gel characterized by being less than 05. The polymer gel according to claim 1,
The polymer gel, wherein the content of the polyol compound in the polymer gel is 5 to 70% by weight. The polymer gel according to claim 1 or 2,
A polymer gel, wherein the polyol compound is a polyether polyol. The polymer gel according to any one of claims 1 to 3,
A polymer gel, wherein the polyol compound is polyether-added (poly) glycerin. The polymer gel according to any one of claims 1 to 4,
A polymer gel, wherein a value of a dynamic storage elastic modulus G ′ at 25 ° C. measured by temperature dispersion at a frequency of 1 Hz is in a range of 5.0 × 10 ^{4 to} 5.0 × 10 ⁵ Pa. The polymer gel according to any one of claims 1 to 5,
The polymer gel, wherein the urethane (meth) acrylate is an aliphatic urethane (meth) acrylate. The polymer gel according to any one of claims 1 to 6,
A polymer gel used as a temporary fixing material for temporarily fixing a metal or glass member to another metal or glass member. The polymer gel according to any one of claims 1 to 6,
A polymer gel used as an adhesive material for bonding a plurality of panels in an optical device.   A polymer gel sheet comprising the polymer gel according to any one of claims 1 to 8.

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