JP2017160451A - Stress distributing film, optical member, and electronic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide is a stress distributing film having excellent stress distributing ability, and also provide an optical member and an electronic member equipped with the stress distributing film.SOLUTION: This stress distributing film comprises a layered body consisting of a plastic film and an adhesive layer. The stress distributing film is such that, when a load is applied from the plastic film side of the layered body in an orthogonal direction to the layered body, the indentation energy is 260 μJ or greater.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stress dispersion film, and an optical member and an electronic member provided with the stress dispersion film.

  An optical film or electronic member such as a touch panel using an LCD, a lens part of a camera, or an electronic device may have an adhesive film attached to the exposed surface side in order to provide rigidity and impact resistance. (For example, patent document 1). Such an adhesive film usually has a base material layer and an adhesive layer.

  The optical member and electronic member as described above may be subjected to a load due to the pushing force in various situations such as assembly, processing, transportation, and use, and the optical member and electronic member may be damaged by the load. Problem arises.

JP 2014-234460 A

  The subject of this invention is providing the stress dispersion film which has the outstanding stress dispersion property. Moreover, it is providing the optical member and electronic member provided with such a stress dispersion film.

The stress dispersion film of the present invention is
A stress dispersion film comprising a laminate of a plastic film and an adhesive layer,
The indentation energy when a load is applied in a direction perpendicular to the laminate from the plastic film side of the laminate is 260 μJ or more.

  In one embodiment, the plastic film has a thickness of 4 μm to 500 μm.

  In one embodiment, the thickness of the said adhesive layer is 1 micrometer-300 micrometers.

  In one embodiment, the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition is derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as an alkyl ester moiety. A polymer (A) having a monomer unit (I) and a monomer unit (II) derived from a (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule.

  In one embodiment, the molar content of NCO groups in the pressure-sensitive adhesive composition is [NCO], the molar content of epoxy groups in the pressure-sensitive adhesive composition is [epoxy], and the pressure-sensitive adhesive composition When the molar content of OH groups in the solvent is [OH] and the molar content of COOH groups in the pressure-sensitive adhesive composition is [COOH], ([NCO] + [epoxy]) / ([OH] + [COOH]) <0.05.

  In one embodiment, the pressure-sensitive adhesive composition contains a bifunctional or higher functional organic polyisocyanate crosslinking agent and / or an epoxy crosslinking agent.

In one embodiment, the pressure-sensitive adhesive composition has a monomer unit derived from an alicyclic structure-containing (meth) acrylic acid ester represented by the general formula (1), and has a weight average molecular weight of 1000 or more and 30000. Less than the polymer (B).
CH ₂ = C (R ¹ ) COOR ² (1)
(In general formula (1), R ¹ is a hydrogen atom or a methyl group, and R ² is a hydrocarbon group having an alicyclic structure.)

  In one embodiment, the loss tangent tan δ in the entire temperature region of −40 ° C. to 150 ° C. of the pressure-sensitive adhesive layer is 0.10 or more.

  The optical member of the present invention includes the stress dispersion film.

  The electronic member of the present invention includes the stress dispersion film.

  According to the present invention, a stress dispersion film having excellent stress dispersibility can be provided. Moreover, the optical member and electronic member provided with such a stress dispersion film can be provided.

It is a schematic sectional drawing of the stress distribution film by one Embodiment of this invention. It is a schematic sectional drawing of the stress distribution film by another one Embodiment of this invention.

  In the present specification, the expression “(meth) acryl” means “acryl and / or methacryl”, and the expression “(meth) acrylate” means “acrylate and / or methacrylate”. "Means. In addition, when there is an expression “weight” in the present specification, it may be read as “mass” which is commonly used as an SI system unit indicating weight.

  In the present specification, when there is an expression “(a) derived monomer unit (A)”, the monomer unit (A) has an unsaturated double bond of the monomer (a). It is a structural unit formed by cleavage by polymerization. Note that a structural unit formed by cleavage of an unsaturated double bond by polymerization means a structure of “RpRqC = CRrRs” (Rp, Rq, Rr, Rs is any suitable bond bonded to a carbon atom through a single bond). Is a structural unit of “—RpRqC—CRrRs—” formed by cleavage of the unsaturated double bond “C═C” of the group) by polymerization.

  In the present specification, the content ratio of the monomer unit in the polymer can be known, for example, by various structural analyzes (for example, NMR) of the polymer. In addition, the content ratio of monomer units derived from the various monomers calculated based on the use amount of the various monomers used in producing the polymer without performing the various structural analyzes as described above. It is good also as a content rate of the monomer unit in a polymer. That is, the content ratio of a certain monomer (m) in the total monomer components used in producing the polymer is the content ratio of the monomer unit derived from the monomer (m) in the polymer. May be treated as

≪ << A. Stress dispersion film >>>>
The stress dispersion film of the present invention includes a laminate of a plastic film and an adhesive layer. The plastic film may be a single layer or two or more layers. The pressure-sensitive adhesive layer may be one layer or two or more layers.

  FIG. 1 is a schematic cross-sectional view of a stress dispersion film according to an embodiment of the present invention. In FIG. 1, the stress dispersion film 100 of the present invention comprises a laminate of a plastic film 10 and an adhesive layer 20. Although not shown in FIG. 1, any appropriate strong adhesive layer may be provided on the surface of the pressure-sensitive adhesive layer 20.

  FIG. 2 is a schematic cross-sectional view of a stress dispersion film according to another embodiment of the present invention. In FIG. 2, the stress dispersion film 100 of the present invention comprises an adhesive layer 20, a plastic film 10, and an adhesive layer 20, and has the adhesive layer 20, the plastic film 10, and the adhesive layer 20 in this order. That is, in FIG. 2, the stress dispersion film 100 of the present invention is composed of a pressure-sensitive adhesive layer 20 and a laminate of the plastic film 10 and the pressure-sensitive adhesive layer 20. Although not shown in FIG. 2, any appropriate strong adhesive layer may be provided on the surface of the pressure-sensitive adhesive layer 20 on one side or both sides.

  In the case where the pressure-sensitive adhesive layer is exposed as the outermost layer, any appropriate separator (release sheet) may be provided on the exposed surface side.

  The stress dispersion film of the present invention has an indentation energy of 260 μJ or more when a load is applied in a direction perpendicular to the laminate from the plastic film side of the laminate of the plastic film and the pressure-sensitive adhesive layer. The method for measuring the indentation energy will be described later. The indentation energy is preferably 260 μJ to 10000 μJ, more preferably 270 μJ to 9000 μJ, still more preferably 280 μJ to 8000 μJ, and particularly preferably 290 μJ to 7000 μJ. When the indentation energy is within the above range, a stress dispersion film having excellent stress dispersibility can be provided.

  The thickness of the plastic film is preferably 4 μm to 500 μm, more preferably 10 μm to 400 μm, still more preferably 15 μm to 350 μm, and particularly preferably 20 μm to 300 μm. When the thickness of the plastic film is within the above range, a stress dispersion film having more excellent stress dispersion can be provided.

  The thickness of the pressure-sensitive adhesive layer is preferably 1 μm to 300 μm, more preferably 2 μm to 250 μm, still more preferably 4 μm to 200 μm, and particularly preferably 5 μm to 150 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, a stress dispersion film having more excellent stress dispersion can be provided.

Any appropriate plastic film can be adopted as the plastic film as long as the effects of the present invention are not impaired. Such plastic films are, for example, compressive strength in the ASTM D695 is preferably ^{100Kg / cm 2 ~3000Kg / cm 2} , more preferably ^{200Kg / cm 2 ~2900Kg / cm 2} , more preferably It was ^{300Kg / cm 2 ~2800Kg / cm 2} , particularly preferably ^{400Kg / cm 2 ~2700Kg / cm 2} . Specific examples of such plastic films include polyester resins, polyolefin resins, polyamide resins, polyimide resins, and the like. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of the polyolefin resin include olefin monomer homopolymers, olefin monomer copolymers, and the like. Specific examples of polyolefin resins include homopolypropylene; block-type, random-type, and graft-type propylene copolymers having an ethylene component as a copolymer component; reactor TPO; low density, high density, linear Low density, ultra-low density, etc. ethylene polymers; ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / acrylic acid And ethylene copolymers such as butyl copolymer, ethylene / methacrylic acid copolymer, and ethylene / methyl methacrylate copolymer.

  The plastic film may contain any appropriate additive as required. Examples of the additive that can be contained in the plastic film include an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a filler, and a pigment. The kind, number, and amount of additives that can be contained in the plastic film can be appropriately set depending on the purpose.

  Any appropriate pressure-sensitive adhesive layer can be adopted as the pressure-sensitive adhesive layer as long as the effects of the present invention are not impaired. Examples of such an adhesive layer include an adhesive layer formed from an acrylic adhesive, an adhesive layer formed from a rubber adhesive, an adhesive layer formed from a silicone adhesive, and a urethane adhesive. And an adhesive layer formed from the agent.

  The pressure-sensitive adhesive layer is preferably formed from a pressure-sensitive adhesive composition.

  For the pressure-sensitive adhesive layer, for example, the pressure-sensitive adhesive composition is applied on any appropriate base material and dried as necessary to form a pressure-sensitive adhesive layer on the base material. Then, if a base material is peeled, an adhesive layer will be obtained. Further, for example, the adhesive composition is applied on any appropriate plastic film, dried as necessary, an adhesive layer is formed on the plastic film, and the plastic film is left as it is. A stress dispersion film including a plastic film is obtained. In addition, for example, a pressure-sensitive adhesive layer obtained by applying a pressure-sensitive adhesive composition on any appropriate base material, drying as necessary, forming a pressure-sensitive adhesive layer on the base material, and peeling the base material By mounting on a plastic film, a stress dispersion film including an adhesive layer and a plastic film is obtained. Further, for example, the pressure-sensitive adhesive composition is applied on any appropriate base material, dried as necessary, a pressure-sensitive adhesive layer is formed on the base material, and the pressure-sensitive adhesive layer formed on the base material is plastic. By transferring to a film, a stress dispersion film including an adhesive layer and a plastic film is obtained.

  Examples of the method for applying the pressure-sensitive adhesive composition include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, extrusion coating using a die coater, and the like.

  Such an adhesive composition is preferably a monomer unit (I) derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as an alkyl ester moiety, and an OH group and / or Or a polymer (A) having a monomer unit (II) derived from a (meth) acrylic acid ester having a COOH group.

  The content ratio of the polymer (A) in the pressure-sensitive adhesive composition is preferably 80% by weight to 100% by weight, more preferably 85% by weight to 100% by weight, and further preferably 90% by weight to 100% by weight. % By weight, particularly preferably 92.5% by weight to 100% by weight, and most preferably 95% by weight to 100% by weight. When the content ratio of the polymer (A) in the pressure-sensitive adhesive composition is within the above range, a stress dispersion film having more excellent stress dispersibility can be provided.

  The polymer (A) has a monomer unit (I) derived from (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as an alkyl ester moiety. In the polymer (A), the monomer unit (I) derived from the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as the alkyl ester moiety may be only one kind, Two or more types may be used.

  The content ratio of the monomer unit (I) derived from the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as the alkyl ester moiety in the polymer (A) is preferably 90% by weight to 99%. 0.5 wt%, more preferably 91 wt% to 99 wt%, further preferably 92 wt% to 98.5 wt%, particularly preferably 93 wt% to 98.2 wt%, Most preferably, it is 94 to 98% by weight. When the content ratio of the monomer unit (I) derived from the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as the alkyl ester moiety in the polymer (A) is within the above range, A stress dispersion film having more excellent stress dispersion can be provided.

  Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as the alkyl ester moiety include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl ( (Meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (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, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate And the like.

  The polymer (A) has a monomer unit (II) derived from a (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule. In the polymer (A), the monomer unit (II) derived from the (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule may be only one type, or two or more types. It may be. The polymer (A) has a more excellent stress dispersibility by having a monomer unit (II) derived from a (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule. Can be provided.

  The content ratio of the monomer unit (II) derived from the (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule in the polymer (A) is preferably 0.5% by weight to 10% by weight. %, More preferably 1% by weight to 9% by weight, still more preferably 1.5% by weight to 8% by weight, particularly preferably 1.8% by weight to 7% by weight, most preferably 2% to 6% by weight. In the polymer (A), the content ratio of the monomer unit (II) derived from the (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule is in the above range, so that it is more excellent. A stress dispersion film having stress dispersibility can be provided.

  Examples of (meth) acrylic acid ester having an OH group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl ( (Meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, vinyl Examples include alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether.

  Examples of (meth) acrylic acid ester having a COOH group in the molecule include, for example, meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotone. An acid etc. are mentioned.

  The polymer (A) may have a monomer unit (III) derived from another monomer. The monomer unit (III) derived from other monomers in the polymer (A) may be only one type or two or more types.

  Examples of other monomers include cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, amide group-containing monomers, imide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, vinyl ether monomers, and N-acryloyl. Examples include morpholine, sulfo group-containing monomers, phosphate group-containing monomers, and acid anhydride group-containing monomers.

  In the pressure-sensitive adhesive composition, the molar content of NCO groups in the pressure-sensitive adhesive composition is [NCO], and the molar content of epoxy groups in the pressure-sensitive adhesive composition is [epoxy]. When the molar content of OH groups of [OH] is [OH] and the molar content of COOH groups in the pressure-sensitive adhesive composition is [COOH], ([NCO] + [epoxy]) / ([OH] + [COOH]) <0.05. When ([NCO] + [epoxy]) / ([OH] + [COOH]) is in the above range, a stress dispersion film having more excellent stress dispersion can be provided. In addition, when an NCO group does not exist in an adhesive composition, it is [NCO] = 0, and when an epoxy group does not exist in an adhesive composition, it is [epoxy] = 0. That is, the lower limit of ([NCO] + [epoxy]) / ([OH] + [COOH]) is zero.

  The pressure-sensitive adhesive composition preferably contains a bifunctional or higher functional organic polyisocyanate crosslinking agent and / or an epoxy crosslinking agent. The bifunctional or higher functional polyisocyanate-based cross-linking agent and / or epoxy-based cross-linking agent that may be included in the pressure-sensitive adhesive composition of the present invention may be one type or two or more types.

  The total content of the above-mentioned bifunctional or higher functional polyisocyanate crosslinking agent and epoxy crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.001 part by weight to 100 parts by weight of the polymer (A). 0.4 part by weight, more preferably 0.0025 part by weight to 0.3 part by weight, still more preferably 0.005 part by weight to 0.2 part by weight, and particularly preferably 0.0075 part by weight. It is -0.15 weight part, Most preferably, it is 0.01 weight part -0.1 weight part. When the total content of the above-mentioned bifunctional or higher organic polyisocyanate crosslinking agent and epoxy crosslinking agent in the pressure-sensitive adhesive composition of the present invention is within the above range with respect to 100 parts by weight of the polymer (A), A stress dispersion film having more excellent stress dispersion can be provided.

  Examples of the bifunctional or higher functional polyisocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; Aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane / tolylene diisocyanate trimer adduct (for example, trade name " Coronate L "), trimethylolpropane / hexamethylene diisocyanate trimer adduct (for example, trade name" Coronate HL "manufactured by Nippon Polyurethane Industry Co., Ltd.), Isocyanurate of support methylene diisocyanate (for example, Nippon Polyurethane Industry Co., Ltd. under the trade name "Coronate HX") isocyanate adducts and the like; and the like.

  Examples of the epoxy crosslinking agent include bisphenol A, epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl ether, trimethylol. Propanetriglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N, N, N ′, N′-tetraglycidyl-m-xylenediamine (for example, trade name “TETRAD-X” manufactured by Mitsubishi Gas Chemical Co., Inc.), 1, Examples include 3-bis (N, N-diglycidylaminomethyl) cyclohexane (for example, trade name “TETRAD-C” manufactured by Mitsubishi Gas Chemical Company, Inc.).

The pressure-sensitive adhesive composition comprises a polymer (B) having a monomer unit derived from an alicyclic structure-containing (meth) acrylic acid ester represented by the general formula (1) and having a weight average molecular weight of 1,000 or more and less than 30,000. May be included.
CH ₂ = C (R ¹ ) COOR ² (1)
(In general formula (1), R ¹ is a hydrogen atom or a methyl group, and R ² is a hydrocarbon group having an alicyclic structure.)

  Only 1 type may be sufficient as a polymer (B), and 2 or more types may be sufficient as it.

  The weight average molecular weight of the polymer (B) is preferably 1000 to 30000, more preferably 1250 to 25000, still more preferably 1500 to 20000, particularly preferably 1750 to 15000, and most preferably 2000. -10000. When the weight average molecular weight of the polymer (B) is within the above range, a stress dispersion film having more excellent stress dispersibility can be provided even if the amount of the crosslinking agent is increased.

  The content of the polymer (B) in the pressure-sensitive adhesive composition is preferably 0.5 to 50 parts by weight, more preferably 1 to 45 parts by weight with respect to 100 parts by weight of the polymer (A). Parts by weight, more preferably 2 parts by weight to 40 parts by weight, particularly preferably 3 parts by weight to 35 parts by weight, and most preferably 4 parts by weight to 30 parts by weight. When the content of the polymer (B) in the pressure-sensitive adhesive composition is within the above range with respect to 100 parts by weight of the polymer (A), even if the amount of the crosslinking agent is increased, more excellent stress dispersibility is obtained. It is possible to provide a stress dispersion film having the same.

  The content ratio of the monomer unit derived from the alicyclic structure-containing (meth) acrylic acid ester represented by the general formula (1) in the polymer (B) is preferably 40% by weight to 99.5% by weight. More preferably, it is 42.5% by weight to 99% by weight, further preferably 45% by weight to 98.5% by weight, particularly preferably 47.5% by weight to 98% by weight, and most preferably Is 50% to 97.5% by weight. The content of the monomer unit derived from the alicyclic structure-containing (meth) acrylic acid ester represented by the general formula (1) in the polymer (B) is within the above range, whereby the amount of the crosslinking agent. Even if it increases, the stress dispersion film which has the outstanding stress dispersion property can be provided.

  Examples of the alicyclic structure-containing (meth) acrylic acid ester represented by the general formula (1) include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl methacrylate, Cyclopentanyloxyethyl acrylate, tricyclopentanyl methacrylate, tricyclopentanyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl Examples include 2-adamantyl methacrylate and 2-ethyl-2-adamantyl acrylate.

  The polymer (B) may have a monomer unit (IV) derived from another monomer. The monomer unit (IV) derived from the other monomer in the polymer (B) may be only one kind or two or more kinds.

  Examples of other monomers that can be included in the polymer (B) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, and t-butyl. (Meth) acrylate, isobutyl (meth) acrylate, hexyl (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, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, acrylic acid, methacrylic acid, carboxyethyl Accel Relay , Carboxy pentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

  The polymer (A) and the polymer (B) can be produced by any appropriate method as long as the effects of the present invention are not impaired. Examples of such production methods include solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, photopolymerization (active energy ray polymerization), and the like. Among these production methods, solution polymerization is preferable from the viewpoint of cost and productivity. The polymer (A) obtained may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, and the like. The polymer (B) obtained may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer and the like.

  Examples of the solution polymerization method include a method in which a monomer component and a polymerization initiator are dissolved in a solvent and polymerized by heating to obtain a polymer solution.

  Examples of the heating temperature at the time of polymerization by heating in solution polymerization include 50 ° C to 90 ° C. Examples of the heating time in the solution polymerization include 1 hour to 24 hours.

  Any appropriate solvent can be used as the solvent used in the solution polymerization as long as the effects of the present invention are not impaired. Examples of such solvents include aromatic hydrocarbons such as toluene, benzene and xylene; esters such as ethyl acetate and n-butyl acetate; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane And organic solvents such as alicyclic hydrocarbons such as methylcyclohexane; ketones such as methyl ethyl ketone and methyl isobutyl ketone; One type of solvent may be sufficient and 2 or more types may be sufficient as it.

  In the production of the polymer (A) and the polymer (B), a polymerization initiator can be used. Only one kind of such polymerization initiator may be used, or two or more kinds thereof may be used. Examples of such a 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), Azo-based initiators such as 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057); potassium persulfate, ammonium persulfate, etc. Persulfate; di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-se -Butyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, 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-hexyl) Peroxy) peroxide initiators such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide; peroxides such as a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate; A redox initiator combined with a reducing agent; and the like.

  Arbitrary appropriate usage-amounts can be employ | adopted for the usage-amount of a polymerization initiator in the range which does not impair the effect of this invention. For example, the amount used is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the monomer component.

  In the production of the polymer (A) and the polymer (B), a chain transfer agent can be used. Such a chain transfer agent may be only 1 type, and 2 or more types may be sufficient as it. Examples of such chain transfer agents include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, methyl thioglycolate, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. Is mentioned.

  Arbitrary appropriate usage-amounts can be employ | adopted for the usage-amount of a chain transfer agent in the range which does not impair the effect of this invention. For example, the amount used is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the monomer component.

  In the production of the polymer (A) and the polymer (B), any other appropriate additive that can be generally used for the polymerization reaction can be used.

  The pressure-sensitive adhesive composition of the present invention may contain a crosslinking catalyst. Any appropriate crosslinking catalyst can be adopted as the crosslinking catalyst as long as the effects of the present invention are not impaired. Examples of such a crosslinking catalyst include metal-based crosslinking catalysts (particularly tin-based crosslinking catalysts) such as tetra-n-butyl titanate, tetraisopropyl titanate, nursem ferric acid, butyltin oxide, and dioctyltin dilaurate. Only one type of crosslinking catalyst may be used, or two or more types may be used.

  Arbitrary appropriate usage-amounts can be employ | adopted for the usage-amount of a crosslinking catalyst in the range which does not impair the effect of this invention. The amount used is, for example, preferably 0.001 to 0.05 parts by weight with respect to 100 parts by weight of the monomer component.

  The pressure-sensitive adhesive composition may contain any appropriate other additive as long as the effects of the present invention are not impaired. Examples of such other additives include silane coupling agents, crosslinking retarders, emulsifiers, colorants, pigments and the like powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, Examples include leveling agents, softeners, antioxidants, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic fillers, organic fillers, metal powders, particles, and foils. Such other additives may be only one kind or two or more kinds.

  The pressure-sensitive adhesive layer preferably has a loss tangent tan δ in the entire temperature range of −40 ° C. to 150 ° C. of 0.10 or more. When the loss tangent tan δ in the entire temperature range of −40 ° C. to 150 ° C. of the pressure-sensitive adhesive layer is 0.10 or more, a stress dispersion film having more excellent stress dispersibility can be provided. A method for measuring the loss tangent tan δ will be described later.

  The upper limit of the loss tangent tan δ in the entire temperature range of −40 ° C. to 150 ° C. of the pressure-sensitive adhesive layer is preferably 2.40 or less, more preferably 2.20 or less, and further preferably 2.00 or less. Yes, particularly preferably 1.80 or less. When the upper limit of the loss tangent tan δ is within the above range, a stress dispersion film having more excellent stress dispersibility can be provided.

  The lower limit of the loss tangent tan δ in the entire temperature range of −40 ° C. to 150 ° C. of the pressure-sensitive adhesive layer is preferably 0.12 or more, more preferably 0.14 or more, and further preferably 0.16 or more. Yes, particularly preferably 0.18 or more. When the lower limit of the loss tangent tan δ is within the above range, a stress dispersion film having more excellent stress dispersibility can be provided.

≪ << C. Optical member, electronic member >>>>
The stress dispersion film of the present invention has excellent stress dispersion. For this reason, it can use suitably as a protective material aiming at protecting an optical member or an electronic member from the impact from the outside. That is, the optical member of the present invention includes the stress dispersion film of the present invention. The electronic member of the present invention includes the stress dispersion film of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. In addition, the test and evaluation method in an Example etc. are as follows. Note that “parts” means “parts by weight” unless otherwise noted, and “%” means “% by weight” unless otherwise noted.

<Measurement of weight average molecular weight>
The weight average molecular weight (Mw) of the polymer was measured using a GPC apparatus (HLC-8220GPC) manufactured by Tosoh Corporation. In addition, the weight average molecular weight (Mw) was calculated | required in the polystyrene conversion value.
The measurement conditions are as follows.
Sample concentration: 0.2% by weight (THF solution)
Sample injection volume: 10 μl eluent THF flow rate: 0.6 ml / min
Measurement temperature: 40 ° C
Sample column: TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column: TSKgel SuperH-RC (1)
Detector: Differential refractometer (RI)

<Preparation of adhesive sheet (A)>
(Examples 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 26, Comparative Examples 1, 3, 5, 7)
The obtained pressure-sensitive adhesive composition was applied to a base material “Lumirror S10” (thickness 50 μm, manufactured by Toray Industries, Inc.) made of a polyester resin so that the thickness after drying with a fountain roll was 10 μm, a drying temperature of 130 ° C., and a drying time. It was cured and dried for 30 seconds. Thus, the adhesive layer was produced on the base material. Subsequently, the surface of the pressure-sensitive adhesive layer was pasted with a silicone-treated surface of a base material made of a polyester resin having a thickness of 25 μm and subjected to silicone treatment on one surface to obtain a pressure-sensitive adhesive sheet (A).
(Examples 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, Comparative Examples 2, 4, 6, 8)
The obtained pressure-sensitive adhesive composition was applied to a base material “Lumirror S10” (thickness 38 μm, manufactured by Toray Industries, Inc.) made of a polyester resin so that the thickness after drying with a fountain roll was 22 μm, a drying temperature of 130 ° C., and a drying time. It was cured and dried for 30 seconds. Thus, the adhesive layer was produced on the base material. Subsequently, the surface of the pressure-sensitive adhesive layer was pasted with a silicone-treated surface of a base material made of a polyester resin having a thickness of 25 μm and subjected to silicone treatment on one surface to obtain a pressure-sensitive adhesive sheet (A).

<Measurement of indentation energy>
Indentation energy was calculated according to the following procedure using a “SAICAS DN-20 type” manufactured by Daipura Wintes Co., Ltd. at a measurement temperature of 25 ° C. and an indentation speed of 5 μm / sec.
(Procedure 1)
The pressure-sensitive adhesive layer side of the obtained pressure-sensitive adhesive sheet (A) was attached to a flat indenter (load detection side), and the base material side of the pressure-sensitive adhesive sheet (A) attached to the flat indenter was pushed into a spherical indenter. The indentation depth (μm) when the load was detected was calculated.
(Procedure 2)
Attach the pressure-sensitive adhesive layer side of the obtained pressure-sensitive adhesive sheet (A) to the slide glass and push it in with the spherical indenter from the base material side (load detection side) of the pressure-sensitive adhesive sheet (A) attached to the slide glass. The indentation was pushed to the required indentation depth.
When the vertical load applied to the spherical indenter is y = f (x) (x: indentation depth), the indentation energy W (μJ) until 20 N is applied to the adhesive layer side of the adhesive sheet (A) is calculated by the following formula. (R is the indentation depth when a load of 20 N is applied to the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet (A)).

<Preparation of adhesive sheet (B)>
The obtained pressure-sensitive adhesive composition has a thickness of 50 μm after drying with a fountain roll on a release surface of a 38 μm-thick polyester film (trade name: MRF, manufactured by Mitsubishi Chemical Polyester Co., Ltd.) having one side peeled with silicone. Then, the coating was cured at a drying temperature of 130 ° C. and a drying time of 3 minutes, and dried. Thus, the adhesive layer was produced on the base material. Next, on the surface of the pressure-sensitive adhesive layer, a 38 μm thick polyester film (trade name: MRF, manufactured by Mitsubishi Chemical Polyester Co., Ltd.) having one surface peeled with silicone is placed so that the peel-treated surface of the film is on the pressure-sensitive adhesive layer side. And coated. In this way, an adhesive sheet (B) was produced.

<Measurement of glass transition temperature (Tg), storage elastic modulus, loss elastic modulus, tan δ (loss tangent)>
It calculated | required by the following method using the dynamic-viscoelasticity measuring apparatus (The Rheometrics company make, ARES).
Only the pressure-sensitive adhesive layer was taken out from the obtained pressure-sensitive adhesive sheet (B), laminated to have a thickness of about 2 mm, punched out to φ7.9 mm, and a cylindrical pellet was prepared as a measurement sample. The measurement sample is fixed to a jig having a φ7.9 mm parallel plate, and the temperature dependence of the storage elastic modulus G ′ and the loss elastic modulus G ″ is measured by the dynamic viscoelasticity measuring device, and tan δ = G ″. Tna δ was calculated as / G ′. The temperature at which the obtained tan δ curve was maximized was defined as the glass transition temperature (Tg) (° C.).
The measurement conditions are as follows.
Measurement: shear mode,
Temperature range: -70 ° C to 150 ° C
Temperature increase rate: 5 ° C / min
Frequency: 1Hz

[Production Example 1]: (Meth) acrylic polymer (1)
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.): 100 parts by weight, 2-hydroxyethyl acrylate (manufactured by Toa Gosei Co., Ltd.): 4 Part by weight, 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.): 0.2 part by weight, ethyl acetate: 156 parts by weight as a polymerization initiator, and nitrogen gas was added while gently stirring. Then, a polymerization reaction was carried out for 6 hours while maintaining the liquid temperature in the flask at around 65 ° C. to prepare a solution (40% by weight) of (meth) acrylic polymer (1) having a weight average molecular weight of 550,000.

[Production Example 2]: (Meth) acrylic polymer (2)
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.): 100 parts by weight, 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) : 10 parts by weight, acrylic acid (manufactured by Toa Gosei Co., Ltd.): 0.02 parts by weight, 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator: 0.2 parts by weight, Ethyl acetate: 156 parts by weight, nitrogen gas was introduced while gently stirring, and the polymerization temperature was kept at around 65 ° C. for 6 hours to conduct a polymerization reaction. A (meth) acrylic polymer having a weight average molecular weight of 540,000 A solution (40% by weight) of polymer (2) was prepared.

[Production Example 3]: (Meth) acrylic polymer (3)
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.): 99 parts by weight, 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.): 1 2 parts by weight, 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator: 1 part by weight, ethyl acetate: 156 parts by weight, nitrogen gas was introduced while gently stirring The liquid temperature in the flask was kept at around 60 ° C. for 7 hours to prepare a solution (39% by weight) of (meth) acrylic polymer (3) having a weight average molecular weight of 1.6 million.

[Production Example 4]: (Meth) acrylic polymer (4)
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.): 92 parts by weight, N-acryloylmorpholine (manufactured by Kojin Co., Ltd.): 5 parts by weight , Acrylic acid (manufactured by Toagosei Co., Ltd.): 2.9 parts by weight, 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.): 0.1 part by weight as the polymerization initiator, ethyl acetate: 200 Charge a part by weight, introduce nitrogen gas with gentle stirring, perform a polymerization reaction for 8 hours while keeping the liquid temperature in the flask at around 55 ° C., and a (meth) acrylic polymer (4) having a weight average molecular weight of 1,800,000. ) Solution (33 wt%).

[Production Example 5]: (Meth) acrylic polymer (5)
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and cooler, 95 parts by weight of butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 5 parts by weight of acrylic acid (manufactured by Toagosei Co., Ltd.), polymerization start 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.): 0.2 part by weight, ethyl acetate: 156 parts by weight, nitrogen gas was introduced while gently stirring, The liquid temperature was kept at around 63 ° C. for 10 hours to prepare a solution (40% by weight) of a (meth) acrylic polymer (5) having a weight average molecular weight of 700,000.

[Production Example 6]: (Meth) acrylic polymer containing alicyclic structure (6)
Cyclohexyl methacrylate as monomer component [Glass transition temperature of homopolymer (polycyclohexyl methacrylate): 66 ° C.]: 95 parts by weight, acrylic acid: 5 parts by weight, 2-mercaptoethanol: 3 parts by weight as chain transfer agent, polymerization started 2,2′-Azobisisobutyronitrile: 0.2 part by weight as an agent and 103.2 parts by weight of toluene as a polymerization solvent were put into a separable flask and stirred for 1 hour while introducing nitrogen gas. did. After removing oxygen in the polymerization system in this way, the temperature was raised to 70 ° C., reacted for 3 hours, and further reacted at 75 ° C. for 2 hours to give a (meth) acrylic polymer having a weight average molecular weight of 4000. A solution (50% by weight) of (6) was obtained.

[Production Example 6]: Alicyclic structure-containing (meth) acrylic polymer (7)
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, condenser, and dropping funnel, toluene: 100 parts by weight, dicyclopentanyl methacrylate (DCPMA) (trade name: FA-513M, Hitachi Chemical) 60 parts by weight, 40 parts by weight of methyl methacrylate (MMA), and 3.5 parts by weight of methyl thioglycolate as a chain transfer agent were added. Then, after stirring for 1 hour at 70 ° C. under a nitrogen atmosphere, 0.2 part by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator was added and reacted at 70 ° C. for 2 hours. Then, the mixture was reacted at 80 ° C. for 4 hours and then at 90 ° C. for 1 hour to obtain a solution (51% by weight) of a (meth) acrylic polymer (7) having a weight average molecular weight of 4000.

Examples 1 and 2
Ethyl acetate in the solution of (meth) acrylic polymer (1) so that the total solid content is 25% by weight with respect to 100 parts by weight of the solid content of the solution of (meth) acrylic polymer (1). The mixture was stirred with a disper to obtain an adhesive composition (1) containing an acrylic resin. The results are shown in Table 1.

[Examples 3 and 4]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). Acetic acid is added so that the total solid content becomes 25% by weight by adding 0.01 part by weight and adding Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst to 0.005 part by weight in terms of solids. Dilution with ethyl and stirring with a disper gave pressure-sensitive adhesive composition (2) containing an acrylic resin. The results are shown in Table 1.

[Examples 5 and 6]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). Acetic acid is added so that the total solid content becomes 25% by weight by adding 0.1 part by weight in terms of content and adding 0.005 part by weight in terms of solid content of Nersem Ferric (Nippon Chemical Industry Co., Ltd.) as a crosslinking catalyst. It was diluted with ethyl and stirred with a disper to obtain an adhesive composition (3) containing an acrylic resin. The results are shown in Table 1.

[Examples 7 and 8]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). 0.05 parts by weight in terms of parts, Nassem Ferric Acid (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst, 0.005 parts by weight in terms of solids, and a solution of (meth) acrylic polymer (6) in terms of solids 5 parts by weight were added, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (4) containing an acrylic resin. The results are shown in Table 1.

[Examples 9 and 10]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). 0.1 parts by weight, 0.15 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a cross-linking catalyst, and 0.005 parts by weight of solid solution, and a solution of (meth) acrylic polymer (6) 5 parts by weight were added, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (5) containing an acrylic resin. The results are shown in Table 1.

[Examples 11 and 12]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). 0.3 parts by weight in terms of part, Nassem Ferric Acid (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst, 0.005 parts by weight in terms of solids, and a solution of (meth) acrylic polymer (6) in terms of solids Was added with 5 parts by weight, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain a pressure-sensitive adhesive composition (6) containing an acrylic resin. The results are shown in Table 1.

[Examples 13 and 14]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). 0.1 parts by weight in terms of content, Nashem Ferric Acid (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst, 0.005 parts by weight in terms of solids, and a solution of (meth) acrylic polymer (7) in terms of solids Was added with 5 parts by weight, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (7) containing an acrylic resin. The results are shown in Table 1.

[Examples 15 and 16]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). 0.3 parts by weight in terms of parts, Nashem Ferric Iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst, 0.005 parts by weight in terms of solids, and a solution of (meth) acrylic polymer (7) in terms of solids 5 parts by weight were added, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (8) containing an acrylic resin. The results are shown in Table 1.

[Examples 17 and 18]
Ethyl acetate in the solution of (meth) acrylic polymer (2) so that the total solid content is 25% by weight with respect to 100 parts by weight of the solid content of the solution of (meth) acrylic polymer (2). And the mixture was stirred with a disper to obtain an adhesive composition (9) containing an acrylic resin. The results are shown in Table 2.

[Examples 19 and 20]
In the solution of the (meth) acrylic polymer (2), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (2). 0.1 parts by weight in terms of minutes, 0.05 parts by weight in terms of solids in terms of TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 0% in terms of solids in terms of Nersem Ferric Acid (manufactured by Nippon Chemical Industry Co., Ltd.) as a crosslinking catalyst 0.005 part by weight was added, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (10) containing an acrylic resin. The results are shown in Table 2.

[Examples 21 and 22]
In the solution of the (meth) acrylic polymer (3), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (3). Acetic acid is added so that the total solid content becomes 25% by weight by adding 0.02 part by weight in terms of content and adding 0.005 part by weight in terms of solid content of Nersem Ferric Acid (manufactured by Nippon Chemical Industry Co., Ltd.) as a crosslinking catalyst. It was diluted with ethyl and stirred with a disper to obtain a pressure-sensitive adhesive composition (11) containing an acrylic resin. The results are shown in Table 2.

[Examples 23 and 24]
TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent is added to the solution of the (meth) acrylic polymer (5) with respect to 100 parts by weight of the solid content of the solution of the (meth) acrylic polymer (5). Add 0.075 parts by weight in terms of solids, and add Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst in an amount of 0.005 parts by weight in terms of solids so that the total solids is 25% by weight. Dilution with ethyl acetate and stirring with a disper gave pressure-sensitive adhesive composition (12) containing an acrylic resin. The results are shown in Table 2.

Example 25
With respect to 100 parts by weight of Hibler 5125 (manufactured by Kuraray), the mixture was diluted with toluene so that the total solid content was 25% by weight to obtain a pressure-sensitive adhesive composition (13) containing a rubber-based resin. The results are shown in Table 2.

Example 26
With respect to 100 parts by weight of Hibler 5127 (manufactured by Kuraray), it was diluted with toluene so that the total solid content was 25% by weight to obtain a pressure-sensitive adhesive composition (14) containing a rubber-based resin. The results are shown in Table 2.

[Comparative Examples 1 and 2]
In the solution of the (meth) acrylic polymer (1), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (1). Acetic acid is added so that the total solid content becomes 25% by weight by adding 0.5 part by weight and adding 0.005 part by weight of Nasem ferric (Nihon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst. Dilution with ethyl and stirring with a disper gave an adhesive composition (C1) containing an acrylic resin. The results are shown in Table 2.

[Comparative Examples 3 and 4]
In the solution of the (meth) acrylic polymer (2), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (2). 0.45 parts by weight in terms of minutes, 0.3 parts by weight in terms of solids in terms of TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 0% in terms of solids in terms of Nersem Ferric Acid (manufactured by Nippon Chemical Industry Co., Ltd.) as a crosslinking catalyst 0.005 part by weight was added, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (C2) containing an acrylic resin. The results are shown in Table 2.

[Comparative Examples 5 and 6]
In the solution of the (meth) acrylic polymer (4), coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) is solidified as a crosslinking agent with respect to the solid content of 100 parts by weight of the solution of the (meth) acrylic polymer (4). Acetic acid is added so that the total solid content becomes 25% by weight by adding 0.35 part by weight and adding Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst to 0.005 part by weight in terms of solids. Dilution with ethyl and stirring with a disper gave an adhesive composition (C3) containing an acrylic resin. The results are shown in Table 2.

[Comparative Examples 7 and 8]
TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent is added to the solution of the (meth) acrylic polymer (5) with respect to 100 parts by weight of the solid content of the solution of the (meth) acrylic polymer (5). 0.075 parts by weight in terms of solid content, Nashem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a crosslinking catalyst, 0.005 parts by weight in terms of solid content, and a solution of (meth) acrylic polymer (6) as solid content 20 parts by weight in terms of conversion was added, diluted with ethyl acetate so that the total solid content was 25% by weight, and stirred with a disper to obtain an adhesive composition (C4) containing an acrylic resin. The results are shown in Table 2.

Example 27
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (1) obtained in Examples 1 and 2, the polyester film is peeled off from one side, and the polarized light which is an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 28
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (2) obtained in Examples 3 and 4, the polyester film is peeled off from one side, and the polarization is an optical member. An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 29
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (4) obtained in Examples 7 and 8, the polyester film is peeled from one side, and the polarized light which is an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 30
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (7) obtained in Examples 13 and 14, the polyester film was peeled from one side, and the polarized light as an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 31
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (9) obtained in Examples 17 and 18, the polyester film was peeled off from one side, and the polarized light as an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

[Example 32]
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (10) obtained in Examples 19 and 20, the polyester film was peeled off from one surface, and polarized light which was an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 33
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (11) obtained in Examples 21 and 22, the polyester film was peeled off from one side, and the polarized light as an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 34
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (12) obtained in Examples 23 and 24, the polyester film was peeled from one side, and the polarized light as an optical member An optical member was obtained by sticking to a plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) and having an adhesive sheet attached thereto.

Example 35
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (13) obtained in Example 25, the polyester film was peeled off from one side, and a polarizing plate (optical member) A product name “TEG1465DUHC” manufactured by Nitto Denko Corporation) was attached to obtain an optical member having an adhesive sheet attached thereto.

Example 36
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (14) obtained in Example 26, the polyester film was peeled off from one side, and a polarizing plate (optical member) A product name “TEG1465DUHC” manufactured by Nitto Denko Corporation) was attached to obtain an optical member having an adhesive sheet attached thereto.

Example 37
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (1) obtained in Examples 1 and 2, the polyester film is peeled off from one side, and the conductive material is an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 38
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (2) obtained in Examples 3 and 4, the polyester film was peeled off from one surface, and the conductive material as an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 39
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (4) obtained in Examples 7 and 8, the polyester film is peeled off from one surface, and the conductive material is an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 40
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (7) obtained in Examples 13 and 14, the polyester film is peeled off from one side, and the conductive material is an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 41
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (9) obtained in Examples 17 and 18, the polyester film was peeled off from one surface, and the conductive material as an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 42
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (10) obtained in Examples 19 and 20, the polyester film was peeled off from one surface, and the conductive material as an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 43
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (11) obtained in Examples 21 and 22, the polyester film was peeled off from one surface, and the conductive material as an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 44
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (12) obtained in Examples 23 and 24, the polyester film was peeled off from one surface, and the conductive material as an electronic member. An adhesive film (manufactured by Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) was attached to obtain an electronic member having an adhesive sheet attached thereto.

Example 45
For each of the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (13) obtained in Example 25, the polyester film is peeled from one surface, and the conductive film is an electronic member. (Nitto Denko Co., Ltd., trade name "Electrista V270L-TFMP") was attached to obtain an electronic member to which an adhesive sheet was attached.

Example 46
For each of the pressure-sensitive adhesive sheet (A) and pressure-sensitive adhesive sheet (B) obtained from the pressure-sensitive adhesive composition (14) obtained in Example 26, the polyester film is peeled off from one surface, and the conductive film is an electronic member. (Nitto Denko Co., Ltd., trade name "Electrista V270L-TFMP") was attached to obtain an electronic member to which an adhesive sheet was attached.

  The stress dispersion film of the present invention can be suitably used as a protective material for the purpose of protecting optical members and electronic members from external impacts, for example.

10 Plastic film 20 Adhesive layer 100 Stress dispersion film

Claims (8)

A stress dispersion film comprising a laminate of a plastic film and an adhesive layer,
The plastic film has a thickness of 15 μm to 300 μm,
The pressure-sensitive adhesive layer has a thickness of 1 μm to 300 μm,
The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition has a monomer unit (I) derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as an alkyl ester moiety. And a polymer (A) having a monomer unit (II) derived from a (meth) acrylic acid ester having an OH group and / or a COOH group in the molecule, or a rubber-based resin ,
The polymer (A) is only one kind,
The indentation energy when a load is applied in a direction perpendicular to the laminate from the plastic film side of the laminate is 280 μJ or more and 7000 μJ or less .
Stress dispersion film.
However, the indentation energy is measured as follows.
Using “SAICAS DN-20 type” manufactured by Daipura Wintes Co., Ltd., the indentation energy is calculated according to the following procedure at a measurement temperature of 25 ° C. and an indentation speed of 5 μm / sec.
(Procedure 1)
The pressure-sensitive adhesive layer side of the laminate is affixed to a flat indenter (load detection side), the plastic film side of the laminate affixed to the flat indenter is pushed into a spherical indenter, and a push when a load of 20 N is detected Depth (μm) is calculated.
(Procedure 2)
The pressure-sensitive adhesive layer side of the laminate is affixed to a slide glass, and is pushed in with a spherical indenter from the plastic film side (load detection side) of the laminate affixed to the slide glass, and is pushed in to the indentation depth determined in Procedure 1.
When the vertical load applied to the spherical indenter is y = f (x) (x: indentation depth), the indentation energy W (μJ) until 20 N is applied to the pressure-sensitive adhesive layer side of the laminate is calculated by the following formula ( r is the indentation depth when a load of 20 N is applied to the pressure-sensitive adhesive layer side of the laminate.

  The stress dispersion film according to claim 1, wherein the plastic film has a thickness of 20 μm to 300 μm. The stress dispersion film according to claim 1 or 2, wherein the pressure-sensitive adhesive layer has a thickness of 1 µm to 150 µm.   The molar content of NCO groups in the pressure-sensitive adhesive composition is [NCO], the molar content of epoxy groups in the pressure-sensitive adhesive composition is [epoxy], and the molar content of OH groups in the pressure-sensitive adhesive composition is When the ratio is [OH] and the molar content of COOH groups in the pressure-sensitive adhesive composition is [COOH], ([NCO] + [epoxy]) / ([OH] + [COOH]) <0 The stress dispersion film according to claim 1, which is 0.05.   The stress dispersion film according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive composition contains a bifunctional or higher functional organic polyisocyanate crosslinking agent and / or an epoxy crosslinking agent.   The stress dispersion film according to any one of claims 1 to 5, wherein a loss tangent tan δ of the pressure-sensitive adhesive layer in a whole temperature range of -40 ° C to 150 ° C is 0.10 or more.   An optical member provided with the stress dispersion film according to claim 1. An electronic member provided with the stress dispersion film according to claim 1.

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