Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1808—C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/08—Processes
  • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/62—Polymers of compounds having carbon-to-carbon double bonds
  • C08G18/6204—Polymers of olefins
  • C08G18/6208—Hydrogenated polymers of conjugated dienes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/75—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic
  • C08G18/751—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring
  • C08G18/752—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group
  • C08G18/753—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group
  • C08G18/755—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D151/00—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
  • C09D151/08—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers grafted on to macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
  • C09J133/04—Homopolymers or copolymers of esters
  • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
  • C09J133/08—Homopolymers or copolymers of acrylic acid esters
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
  • C09J175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
  • C09J175/16—Polyurethanes having carbon-to-carbon unsaturated bonds having terminal carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
  • C09J4/06—Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/20—Esters of polyhydric alcohols or phenols, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
  • C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
  • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
  • C09J2301/124—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape

Definitions

• the present invention relates to a method for producing a transparent double-sided pressure-sensitive adhesive sheet obtained by curing a photocurable resin composition, a transparent double-sided pressure-sensitive adhesive sheet, a touch panel using the transparent double-sided pressure-sensitive adhesive sheet, and an image display device using the transparent double-sided pressure-sensitive adhesive sheet.
• an image display device such as a liquid crystal display and an input device used in combination with the image display device such as a touch panel have been widely used in the fields of mobile phones and game machines.
• transparent double-sided pressure-sensitive adhesive sheets are used for the purpose of bonding optical members.
• ⁇ Double-sided pressure-sensitive adhesive sheets used for image display devices and touch panels are required not only to exhibit transparency and adhesiveness but also to fully exhibit the characteristics of pressure-sensitive adhesive sheets in various environments.
• a double-sided pressure-sensitive adhesive sheet having properties that do not adversely affect the visibility and appearance retention of attached optical members and optical products at high temperatures, and a double-sided pressure-sensitive adhesive sheet with little change in storage elastic modulus due to temperature change are required. It has been.
• a thick film of 100 ⁇ m or more is often used as a transparent double-sided pressure-sensitive adhesive sheet used for the purpose of bonding an optical member.
• a transparent double-sided pressure-sensitive adhesive sheet having a thickness of 100 ⁇ m or more can be obtained by a method in which a polymer solution is applied onto a support such as a film, and then the solvent is heated to distill off. Has the problem of requiring a lot of energy and time.
• a sheet having a film thickness of 100 ⁇ m or more can be easily obtained by applying a photocurable composition that does not use a solvent on a support and then producing a pressure-sensitive adhesive sheet by polymerization by light irradiation. I can do it.
• polymerization by light irradiation has a problem in that it is difficult to set the amount of photopolymerization initiator and light irradiation conditions, and the productivity is not sufficiently increased. That is, if the amount of the photopolymerization initiator is increased in order to increase the productivity, the molecular weight decreases, so there is a problem that the storage elastic modulus at a high temperature decreases, and on the other hand, if the light irradiation time is shortened, the polymerization rate does not increase. There was a problem that the residual monomer increased.
• a photopolymerizable acrylic pressure-sensitive adhesive composition layer is provided on one side of the film-like base material, and is not in contact with the film-like base material of the photopolymerizable acrylic pressure-sensitive adhesive composition layer.
• a method of manufacturing a photopolymerizable acrylic pressure-sensitive adhesive sheet in which a cover film is bonded to one surface and polymerized by irradiation with ultraviolet rays is disclosed (for example, see Patent Document 1).
• this method has a problem that the temperature control in the curing process for reducing the residual monomer is complicated.
• the problem to be solved by the present invention is to provide a method for producing a transparent double-sided PSA sheet that obtains a thick film sheet with little change in storage modulus due to temperature change and low residual monomer, and further provides a transparent double-sided PSA sheet. It is.
• the present inventors have made extensive studies and as a result, the resin layer of the photocurable resin composition on the light transmissive film (Y). Further, a light-transmitting film (Z) is laminated on the surface of the resin layer opposite to the surface in contact with the light-transmitting film (Y), and the laminated body obtained by the lamination has a low illuminance black
• the manufacturing method of irradiating light and then irradiating active energy rays with high illuminance has found that there is little change in elastic modulus with temperature change, and that there are also few residual monomers, and the present invention has been completed based on this finding did.
• the present invention is indicated by (I) to (VI) below.
• (I) A method for producing a transparent double-sided pressure-sensitive adhesive sheet obtained by curing a photocurable resin composition, (1) applying a photocurable resin composition on the light transmissive film (Y) to form a resin layer having a thickness of 0.01 to 3 mm; (2) Laminating a light transmissive film (Z) on the formed resin layer; (3) irradiating the laminate obtained by lamination with black light at an irradiation dose of 10 to 300 mJ / cm 2 ; (4) a step of irradiating an active energy ray at a dose of 500 to 5000 mJ / cm 2 to the laminate irradiated with black light; About the transparent double-sided pressure-sensitive adhesive sheet in a state where both light-transmitting films are peeled off, (a) storage elastic modulus when dynamic viscoelasticity is measured under conditions of 40 ° C. and 1 Hz, and (b) conditions of 100 ° C. and 1 Hz The storage elastic modulus when dynamic viscoelasticity is measured with the formula (
• the photocurable resin composition comprises (A) (meth) acrylic group-containing polyolefin compound 20 to 50% by mass, (B) (meth) acrylic monomer 49.8 to 79.8% by mass, and ( C) The method for producing a transparent double-sided pressure-sensitive adhesive sheet according to (I), comprising 0.2 to 5% by mass of a photopolymerization initiator.
• (IV) (A) The (meth) acryl group-containing polyolefin compound has a hydrogenated polybutadiene skeleton or a hydrogenated polyisoprene skeleton, and (B) (meth) acrylic monomer is an alkyl (meth) acrylate and / or a cyclic alkyl (The method for producing a transparent double-sided pressure-sensitive adhesive sheet according to (II) or (III), comprising (meth) acrylate, wherein (C) the photopolymerization initiator comprises a carbonyl-based photopolymerization initiator.
• the method for producing a transparent double-sided pressure-sensitive adhesive sheet of the present invention it is possible to obtain a transparent double-sided pressure-sensitive adhesive sheet with little change in elastic modulus due to temperature change and little residual monomer.
• the transparent double-sided adhesive sheet obtained by the manufacturing method of this invention can be used for bonding of an optical member, and can be used suitably especially for bonding of a touch panel and an image display apparatus. Therefore, since this invention can obtain such a transparent double-sided adhesive sheet efficiently, its industrial use value is very high.
• a method for producing a transparent double-sided PSA sheet obtained by curing the photocurable resin composition of the present invention (1) applying a photocurable resin composition on the light transmissive film (Y) to form a resin layer having a thickness of 0.01 to 3 mm; (2) Laminating a light transmissive film (Z) on the formed resin layer; (3) irradiating the laminate obtained by lamination with black light at an irradiation dose of 10 to 300 mJ / cm 2 ; (4) a step of irradiating an active energy ray at a dose of 500 to 5000 mJ / cm 2 to the laminate irradiated with black light;
• About the transparent double-sided pressure-sensitive adhesive sheet in a state where both light-transmitting films are peeled off (a) storage elastic modulus when dynamic viscoelasticity is measured under conditions of 40 ° C. and 1 Hz, and (b) conditions of 100 ° C. and 1 Hz
• the storage elastic modulus when dynamic viscoelasticity is measured with the formula (
• step (1) A step of applying a photocurable resin composition on the light transmissive film (Y) of the present invention to form a resin layer having a thickness of 0.01 to 3 mm (hereinafter referred to as “step (1)”).
• step (2) the light transmissive film used in the step of laminating the light transmissive film (Z) on the formed resin layer (hereinafter referred to as “step (2)”) is generally an adhesive tape.
• the peeling film currently used for the adhesive sheet, a peeling sheet, or a separator can be used. Different light transmissive films may be used in the steps (1) and (2) of the present invention.
• a polyester film such as polyethylene terephthalate (PET) or a polyolefin film such as a polypropylene film or a polyethylene film can be used.
• PET polyethylene terephthalate
• a polyolefin film such as a polypropylene film or a polyethylene film
• the surface of the light transmissive film is preferably treated with a release agent such as a silicone release agent or a fluorine release agent.
• the surface of the photocurable resin composition formed in the step (1) is light transmissive on the surface opposite to the surface on which the light transmissive film (Y) is laminated. Laminate the film (Z).
• the thickness of the light-transmitting film can be appropriately selected according to the desired strength, flexibility, purpose of use, etc., and is not particularly limited, but is generally 10 to 300 ⁇ m, preferably 20 to 200 ⁇ m, more The thickness is preferably 30 to 150 ⁇ m.
• light-transparent films having different thicknesses may be used. If the thickness of the light transmissive film is less than 10 ⁇ m, the film may be deformed by reaction heat generated in the process of curing the photocurable resin composition, which is not preferable. If the thickness of the light transmissive film is larger than 300 ⁇ m, the transmittance of black light and active energy rays may be deteriorated, which is not preferable.
• the photocurable resin composition used in the present invention if it has an appropriate adhesive force when used as a transparent double-sided pressure-sensitive adhesive sheet, and has no problem in optical properties such as transparency and yellowing, particularly although not limited, it is preferable to use a photocurable resin composition containing (A) (meth) acrylic group-containing polyolefin compound, (B) (meth) acrylic monomer and (C) photopolymerization initiator.
• any polyolefin compound having a polyolefin skeleton and having a (meth) acryl group introduced therein can be used.
• Polyolefin skeletons that can be used for (meth) acrylic group-containing polyolefin compounds include skeletons derived from polyethylene, polypropylene, ethylene / propylene copolymers, butadiene, isoprene, hydrogenated polybutadiene, hydrogenated polyisoprene, cycloolefin, etc. Is mentioned.
• the (A) (meth) acryl group-containing polyolefin compound preferably has a hydrogenated polybutadiene skeleton or a hydrogenated polyisoprene skeleton in terms of light resistance, transparency (non-crystalline), and workability (liquid).
• the (meth) acryl group means CH 2 ⁇ CH—CO— or CH 2 ⁇ C (CH 3 ) —CO—.
• (A) As a (meth) acryl group-containing polyolefin compound a compound having a polyolefin skeleton and an isocyanate group or a hydroxyl group is subjected to a urethanization reaction of a (meth) acrylate having a hydroxyl group or an isocyanate group, thereby producing a molecule in the molecule.
• (A) (Meth) acrylic group-containing polyolefin compound obtained by introducing a (meth) acrylic group into is preferable from the viewpoint of adhesiveness and toughness.
• (A) As a synthesis method of the (meth) acryl group-containing polyolefin compound the following two-step reaction can be exemplified.
• the two-step reaction as the first example is as follows. First, a polyfunctional isocyanate compound having two or more isocyanate groups in one molecule (hereinafter sometimes referred to as “polyfunctional isocyanate compound”) with respect to the polyolefin polyol is used in a proportion in which the amount of isocyanate groups is larger than the amount of hydroxyl groups. By reacting, a urethane prepolymer having an isocyanate group is synthesized. At this time, the molecular weight can be adjusted by adjusting the ratio of the hydroxyl group equivalent of the polyolefin polyol and the isocyanate group equivalent of the polyfunctional isocyanate compound.
• a (meth) acrylate having a hydroxyl group in the obtained urethane prepolymer a hydroxyalkyl (meth) acrylate or a (meth) acrylate monool derived from various polyols (with one hydroxyl group remaining, various polyols ( A (meth) acrylate group-containing polyolefin compound is obtained by reacting (meth) acrylate) and converting the remaining isocyanate group to a (meth) acryl group.
• hydroxyalkyl (meth) acrylate examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,3-butanediol (meth) acrylate, Examples thereof include 1,4-butanediol (meth) acrylate, 1,6-hexanediol (meth) acrylate, 3-methylpentanediol (meth) acrylate and the like, and these can be used alone or in combination of two or more. Of these, 2-hydroxyethyl acrylate is preferred in terms of reactivity with isocyanate groups and photocurability.
• the (meth) acryl group content can be adjusted by reacting the alkyl alcohol with an isocyanate group.
• the saturated alcohol that can be used is not particularly limited, and one or more linear, branched, or alicyclic alkyl alcohols can be used.
• the two-step reaction as the second example is as follows. First, a polyfunctional isocyanate compound is reacted with a polyolefin polyol at a ratio in which the hydroxyl group equivalent is larger than the isocyanate group equivalent to synthesize a polyurethane compound having a hydroxyl group with an extended chain length. At this time, the molecular weight can be adjusted by adjusting the ratio of the hydroxyl group equivalent of the polyolefin polyol and the isocyanate group equivalent of the polyfunctional isocyanate compound. At this time, the content of the (meth) acrylic group can be adjusted by adjusting the amount of the isocyanate group-containing (meth) acrylate to be reacted with the remaining hydroxyl group.
• the isocyanate group-containing (meth) acrylate a commercially available compound may be used, or a hydroxyalkyl (meth) acrylate or (meth) acrylate monool derived from various polyols and a diisocyanate compound are reacted to form an isocyanate group at one end, What synthesized the isocyanate group containing (meth) acrylate which has a (meth) acryl group in the other terminal may be used.
• the isocyanate group-containing (meth) acrylate include 2-isocyanatoethyl (meth) acrylate and 1,1-bis (acryloyloxymethyl) ethyl isocyanate. Of these, 2-isocyanatoethyl acrylate is preferred from the viewpoints of reactivity with hydroxyl groups and photocurability.
• the two-step reaction in the above two examples is a reaction between a hydroxyl group and an isocyanate group, and a general urethane such as dibutyltin dilaurate or dibutyltin diethylhexoate in the presence of an organic solvent inert to the isocyanate group.
• the reaction is usually carried out continuously at 30 to 100 ° C. for about 1 to 5 hours using the catalyst.
• the amount of the urethanization catalyst used is usually 50 to 500 ppm based on the total mass of the raw materials used for the reaction.
• the above polyolefin polyol preferably has a number average molecular weight of 500 to 5,000, more preferably 1,000 to 4,000.
• the number average molecular weight is smaller than 500, the number of urethane bonds in the (A) (meth) acryl group-containing polyolefin compound is excessive, which may cause yellowing during curing, which is not preferable.
• the number average molecular weight is greater than 5,000, the compatibility between the (meth) acrylic group-containing polyolefin compound and the (meth) acrylic acid ester is unfavorable.
• the polyolefin polyol used in the present invention is preferably hydrogenated 1,2-polybutadiene diol or hydrogenated polyisoprene diol from the viewpoint of light resistance, transparency (non-crystalline) and workability (liquid).
• Specific examples of commercially available hydrogenated 1,2-polybutadiene polyols that can be used include products manufactured by Nippon Soda Co., Ltd., product names: GI-1000, GI-2000, GI-3000 (number average molecular weights of about 1500 each). , About 2100, about 3000).
• Specific examples of commercially available hydrogenated polyisoprene polyols include Idemitsu Kosan Co., Ltd. product name Epol (number average molecular weight of about 2500).
• polyfunctional isocyanate compound examples include diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, and hydrogenated products thereof, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, And diisocyanate compounds such as tetramethylxylylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexyl diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and norbornane diisocyanate.
• diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, and hydrogenated products thereof, hexamethylene diisocyanate, trimethylhe
• isophorone diisocyanate or hydrogenated diphenylmethane diisocyanate is preferred from the viewpoint of light resistance and ease of reactivity control.
• These compounds having two or more isocyanate groups in one molecule can be used alone or in combination of two or more.
• the above (A) (meth) acryl group-containing polyolefin compound is made to have a high molecular weight by reacting a polyolefin polyol and a polyfunctional isocyanate compound, and then 50 to 100 mol% (meth ) It is preferable to introduce an acrylic group, and it is more preferable to introduce 70 to 100 mol% of a (meth) acrylic group.
• the ratio of introducing the (meth) acrylic group is less than 50 mol%, there is a large change in storage elastic modulus depending on the temperature of the transparent double-sided PSA sheet that can be obtained by the presence of polyolefin polyol that cannot introduce the (meth) acrylic group. This is not preferable.
• the content of the (A) (meth) acrylic group-containing polyolefin compound is preferably 20 to 50% by mass, more preferably 22 to 45% by mass in the photocurable resin composition, and more preferably 25 to More preferably, it is 40 mass%.
• the content of the (A) (meth) acrylic group-containing polyolefin compound is less than 20% by mass, there is a possibility that a change in storage elastic modulus due to a temperature change of the obtained transparent double-sided PSA sheet is increased, which is not preferable.
• the amount is more than 50% by mass, the compatibility with the (B) (meth) acrylic monomer may be deteriorated, which is not preferable.
• the above (B) (meth) acrylic monomer means an acrylic monomer or methacrylic monomer having one or more (meth) acrylic groups in the molecule.
• the (B) (meth) acrylic monomer that can be used is not particularly limited, and a monofunctional or polyfunctional photopolymerizable monomer having a (meth) acryl group may be used alone or in combination of two or more. Can be used.
• (B) (meth) acrylic monomer examples include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and tert-butyl (meth).
• Alkyl such as acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-hexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate (Meth) acrylate, cyclohexyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, norbornanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, disi Cycloalkyl (meth) acrylates such as lopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, tricyclodecane dimethylo
• alkyl (meth) acrylates and cyclic alkyl (meth) acrylates are preferably used from the viewpoints of tackiness, reactivity, and transparency, and cyclohexyl acrylate and 2-ethylhexyl acrylate are particularly preferably used.
• the content of the (B) (meth) acrylic monomer is preferably 49.8 to 79.8% by mass and more preferably 55 to 78% by mass in the photocurable resin composition. 60 to 75% by mass is more preferable.
• the content of the (B) (meth) acrylic monomer is less than 49.8% by mass, the compatibility with the (A) (meth) acrylic group-containing polyolefin compound may be unfavorable.
• the content of the (B) (meth) acrylic monomer is more than 79.8% by mass, the change in the storage elastic modulus depending on the temperature of the obtained transparent double-sided PSA sheet is unfavorable.
• Examples of the (C) photopolymerization initiator include carbonyl photopolymerization initiator, sulfide photopolymerization initiator, quinone photopolymerization initiator, azo photopolymerization initiator, sulfochloride photopolymerization initiator, and thioxanthone. System photopolymerization initiator or peroxide photopolymerization initiator.
• carbonyl photopolymerization initiator examples include benzophenone, benzyl, benzoin, ⁇ -bromoacetophenone, chloroacetone, acetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, p-dimethylamino.
• Examples of the sulfide photopolymerization initiator include diphenyl disulfide, dibenzyl disulfide, tetraethylthiuram disulfide, tetramethylammonium monosulfide and the like.
• Examples of the quinone photopolymerization initiator include benzoquinone and anthraquinone.
• Examples of the azo photopolymerization initiator include azobisisobutyronitrile, 2,2'-azobispropane, hydrazine and the like.
• Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, and the like.
• the peroxide photopolymerization initiator examples include benzoyl peroxide and di-t-butyl peroxide.
• the photopolymerization initiator it is preferable to use a carbonyl-based photopolymerization initiator, and it is particularly preferable to use 1-hydroxycyclohexyl phenyl ketone from the viewpoint of solubility in the resulting photocurable resin composition. .
• These (C) photoinitiators are used individually or in combination of 2 or more types.
• the content of the photopolymerization initiator is 0.2 to 5% by mass in the photocurable resin composition in terms of the balance between photocurability and the strength and adhesiveness of the obtained transparent double-sided PSA sheet. It is preferably 0.5 to 3% by mass, more preferably 0.8 to 2% by mass.
• content of a photoinitiator is less than 0.2 mass%, photocuring tends to become inadequate, and when it exceeds 5 mass%, the adhesiveness of the transparent double-sided adhesive sheet obtained will fall. It tends to be unfavorable.
• a tackifier resin may be added as long as the transparency is not lowered in order to improve the adhesive strength of the obtained pressure-sensitive adhesive sheet.
• tackifier resins include rosin resins such as rosin and rosin esterified products, terpene resins such as diterpene polymers and ⁇ -pinene-phenol copolymers, aliphatic (C5) and aromatic ( C9-based) and other petroleum resins, as well as styrene-based resins, phenol-based resins, xylene resins, and the like.
• alicyclic tackifying resins with few unsaturated double bonds are preferred from the viewpoint of light resistance.
• Specific alicyclic tackifier resins include rosin and rosin derivative hydrogenated resins, polyterpene resin hydrogenated resins, aromatic modified terpene resin hydrogenated resins, terpene phenol resin hydrogenated resins, coumarone and indene resins. Hydrogenated resin, alicyclic petroleum resin hydrogenated resin, aromatic petroleum resin hydrogenated resin, aliphatic aromatic copolymer petroleum resin hydrogenated resin, dicyclopentadiene petroleum resin hydrogenated resin And a hydrogenated resin of a dicyclopentadiene aromatic copolymer system and a hydrogenated resin of a low molecular weight polymer of styrene or substituted styrene.
• the alicyclic tackifying resin can be used alone or in combination of two or more.
• the addition amount of the tackifying resin is preferably 0 to 20 parts by mass, more preferably 0 to 15 parts by mass, and 0 to 10 parts by mass with respect to 100 parts by mass of the photocurable resin composition. More preferably. If the addition amount of the tackifying resin exceeds 20 parts by mass with respect to 100 parts by mass of the photocurable resin composition, the transparency of the obtained adhesive sheet tends to be too bad, which is not preferable.
• the photocurable resin composition of the present invention may contain various known additives as long as the transparency is not impaired.
• Additives include plasticizers, surface lubricants, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, light stabilizers such as benzotriazoles, phosphate esters, and others Flame retardants, and antistatic agents such as surfactants.
• the thickness when the photocurable resin composition of the present invention is applied is in the range of 0.01 to 3 mm, more preferably 0.015 to 1 mm, and still more preferably 0.02 to 0.5 mm. It is. If the coating thickness is less than 0.01 mm, it is difficult to uniformly apply the film thickness, which may cause unevenness in the film thickness. When the thickness is larger than 3 mm, it is not preferable because it is difficult to transmit ultraviolet rays and the curability may be deteriorated.
• the method of applying the photocurable resin composition on the light transmissive film (Y) is a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, comma coater or direct coater. It does not restrict
• step (3) there is (3) a step of irradiating the laminate obtained by laminating with black light at an irradiation dose of 10 to 300 mJ / cm 2 (hereinafter referred to as “step (3)”).
• Black light is a lamp that emits only near-ultraviolet light having a wavelength of 300 to 400 nm.
• the black light that can be used is not particularly limited as long as the light intensity at a wavelength of 365 nm is in the range of 0.20 to 10 mW / cm 2 , and a commercially available one can be used.
• the light intensity at a wavelength of 365 nm is preferably 0.20 to 10 mW / cm 2 , and more preferably 0.5 to 5 mW / cm 2 .
• the irradiation amount of black light is 10 to 300 mJ / cm 2 , the more preferable irradiation amount is 15 to 200 mJ / cm 2 , and the further preferable irradiation amount is 20 to 100 mJ / cm 2 .
• the black light is irradiated at an angle substantially perpendicular to the plane on which the photocurable resin composition of the laminate obtained by lamination is applied.
• the black light may be irradiated from one side or both sides of the laminate.
• step (4) a step of irradiating the laminate irradiated with black light with active energy rays at an irradiation dose of 500 to 5000 mJ / cm 2 (hereinafter referred to as “step (4)”. ").
• the active energy ray is a general term for an electron beam, an X-ray, an ultraviolet ray, a high-energy electron beam such as visible light in a low wavelength region, or an electromagnetic wave.
• the active energy ray that can be used, those having a light intensity in the range of 20 to 500 mW / cm 2 at a wavelength of 365 nm are preferable, and a high pressure mercury lamp, a metal halide lamp and the like are exemplified as a light source.
• the irradiation dose of the active energy ray in the range of 500 ⁇ 5000mJ / cm 2, more preferably in the range of 600 ⁇ 3000mJ / cm 2, more preferably in the range of 700 ⁇ 2000mJ / cm 2.
• the irradiation amount of active energy rays is less than 500 mJ / cm 2 , the residual monomer of the obtained transparent double-sided PSA sheet increases.
• an active energy ray is irradiated at an angle substantially perpendicular to the plane on which the photocurable resin composition is applied. Further, the active energy ray may be irradiated from one side or both sides of the laminate.
• the transparent double-sided pressure-sensitive adhesive sheet obtained from the method for producing a transparent double-sided pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet layer obtained by curing a photocurable resin composition (that is, transparent in a state where both light-transmitting films are peeled off).
• a photocurable resin composition that is, transparent in a state where both light-transmitting films are peeled off.
• (Double-sided PSA sheet) (a) Storage elastic modulus when dynamic viscoelasticity is measured under conditions of 40 ° C. and 1 Hz and (b) Storage elastic modulus when dynamic viscoelasticity is measured under conditions of 100 ° C. and 1 Hz The rate is the formula (I): It satisfies.
• the transparent double-sided PSA sheet preferably satisfies the condition 1 ⁇ (a) / (b) ⁇ 1.45, and more preferably satisfies the condition 1 ⁇ (a) / (b) ⁇ 1.4.
• the transparent double-sided pressure-sensitive adhesive sheet is (a) / (b) ⁇ 1.5, the change in storage elastic modulus due to temperature change of the obtained transparent double-sided pressure-sensitive adhesive sheet is large.
• the transparent double-sided PSA sheet may be altered, which is not preferable.
• the light-transmitting film ( Y) forming a resin layer of the photocurable resin composition on the laminate, and laminating the light transmissive film (Z) on the surface of the resin layer opposite to the surface in contact with the light transmissive film (Y). It is necessary to harden the photocurable resin composition through the steps (3) and (4) with respect to the laminate obtained in (1).
• the high-pressure mercury lamp and metal halide lamp which are the light sources of the active energy rays described above have high illuminance and include light having a wavelength of 400 nm or more, and thus heat the laminate.
• the black light has a low illuminance and contains almost no light of 400 nm or more, so the laminate is not heated.
• the photocurable resin composition is cured at low illuminance and low temperature by the step (3), a polymer having a high molecular weight and a high gel fraction can be obtained.
• a transparent double-sided pressure-sensitive adhesive sheet with little decrease in storage modulus at high temperatures can be obtained. Furthermore, residual monomer can be reduced by performing the process (4) after the process (3).
• the mass of the pressure-sensitive adhesive sheet layer obtained by curing the photocurable resin composition (that is, the transparent double-sided pressure-sensitive adhesive sheet in a state where both light-transmitting films are peeled off).
• the amount of the remaining monomer is preferably 1 to 500 wtppm, more preferably 1 to 400 wtppm, and still more preferably 1 to 300 wtppm.
• the amount of the remaining monomer is more than 500 wtppm with respect to the mass of the pressure-sensitive adhesive sheet layer obtained by curing the photocurable resin composition, there is an odor problem, which is not preferable.
• the transparent double-sided PSA sheet obtained by the method for producing a transparent double-sided PSA sheet of the present invention is an optical transparent double-sided PSA sheet used for optical applications. More specifically, it is used for applications for bonding optical members (for optical member bonding), optical product manufacturing applications, and the like. Although it will not specifically limit if it is a member which has an optical characteristic as an optical member, For example, the member used for an image display apparatus, a touchscreen, or these apparatuses is mentioned, For example, a polarizing plate, phase difference, etc. Plate, optical compensation film, brightness enhancement film, light guide plate, reflection film, antireflection film, transparent conductive film, design film, decorative film, surface protection film, prism, lens, color filter, transparent substrate, and these are laminated The member which has been mentioned.
• the transparent double-sided pressure-sensitive adhesive sheet of the present invention is particularly preferably used for bonding members constituting a touch panel and an image display device.
• the image display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), and electronic paper.
• Examples 1 and 2 and Comparative Examples 1 to 4 Under the conditions shown in Table 1, the prepared photocurable resin composition was applied onto a 50 ⁇ m-thick release PET film (PET-O2-50-BU, manufactured by Mitsui Chemical Tosero Co., Ltd.) using an applicator.
• PET-O2-50-BU manufactured by Mitsui Chemical Tosero Co., Ltd.
• the storage elastic modulus was measured in a shear mode (1 Hz) using a dynamic viscoelasticity measuring device ARES manufactured by TI Instruments. A laminate of five transparent double-sided PSA sheets from which the peeled PET film had been removed was punched with a 7.9 mm ⁇ punching blade to obtain a test piece. Measured at a rate of temperature increase of 5 ° C./min in the measurement range of ⁇ 30 to 150 ° C., among these (a) storage elastic modulus at 40 ° C. and 1 Hz and (b) storage elastic modulus at 100 ° C. and 1 Hz (a) / (B) was calculated and shown in Table 1.
• the measurement conditions are Column; ZB-5 Column temperature: 50 ° C. (maintained for 1 minute) ⁇ increased at 20 ° C./minute ⁇ 250 ° C. (maintained for 5 minutes when reaching 250 ° C.) Detector; FID
• the transparent double-sided pressure-sensitive adhesive sheet production method of the example is superior to the comparative example in that the change in storage elastic modulus is small due to temperature change and the residual monomer is small. Recognize.
• the method for producing a transparent double-sided pressure-sensitive adhesive sheet obtained by curing the photocurable resin composition of the present invention can provide a thick film sheet with little change in storage elastic modulus due to temperature change and little residual monomer.
• the transparent double-sided PSA sheet that is useful as a method for producing a PSA sheet is suitably used for touch panels and image display devices.

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• 2012
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