Adhesive composition, adhesive sheet and display including the same

Abstract

The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet manufactured using the same, and a display including the same. The present invention relates to a pressure-sensitive adhesive composition that is environmentally friendly and has excellent durability and reliability even in high-temperature and high-humidity environments, as it contains an acrylic copolymer polymerized by mixing biomass-derived monomers, and to a pressure-sensitive adhesive sheet manufactured using the same and a display including the same.

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet produced using the same, and a display including the same. [Background technology]

[0002] Optically clear pressure sensitive adhesives are widely used in the display industry to mount touch panels or touch screens and to provide high brightness and transparency.

[0003] Adhesives used to attach transparent films or ultra thin glass (UTG) to touch screens or touch panels used in the display industry are required to have adhesion to various substrates as well as durability to prevent curling or bubbles even when exposed to harsh conditions such as high temperature and high humidity.

[0004] The adhesive is manufactured using petrochemical products derived from the petroleum refining process, and such petrochemical products can result in significant environmental costs due to international agreements that strictly regulate greenhouse gas emissions.

[0005] Therefore, efforts are underway to develop environmentally friendly materials that can replace existing petrochemical products.

[0006] In particular, in fields requiring precise dimensional stability such as electronic materials, durability must be satisfied to prevent the occurrence of curling, bubbles, or peeling under harsh conditions such as high temperature and high humidity, as described above. Therefore, there is a need to develop a pressure-sensitive adhesive composition that has such excellent durability while using environmentally friendly materials.

[0007] Korean Patent Registration No. 10-1535564 discloses a starch-based polymer particle emulsion for adhesives that provides an adhesive aqueous emulsion containing a core-shell structured starch-based polymer and water, and is environmentally friendly and has excellent initial adhesive strength, peel adhesion strength to adherends, and removability. However, there are still problems with preventing curling, bubbles, or peeling under harsh conditions such as high temperature and high humidity. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention is intended to solve the above-mentioned problems of the prior art, and aims to provide a pressure-sensitive adhesive composition that uses environmentally friendly materials and has excellent durability.

[0009] Another object of the present invention is to provide a pressure-sensitive adhesive sheet that is environmentally friendly and does not deform even in high-temperature and high-humidity environments.

[0010] Furthermore, the present invention seeks to provide an environmentally friendly yet highly reliable display.

[0011] However, the problems to be solved by the present application are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides a pressure-sensitive adhesive composition comprising an acrylic copolymer polymerized with a compound represented by the following Chemical Formula 1: [Chemical formula 1] [ka] In the above formula 1, R 1 is hydrogen or a methyl group, and R 2 is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms.

[0013] In the present invention, the acrylic copolymer may be one obtained by polymerizing at least one monomer selected from the group consisting of (meth)acrylates, carboxyl group-containing monomers, and hydroxyl group-containing monomers.

[0014] In the present invention, the hydroxy group-containing monomer may include a compound represented by the following Chemical Formula 6. [Chemical formula 6] [ka] In the above formula 6, R 3 is hydrogen or a methyl group, and R 4 is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms.

[0015] In the present invention, the chemical formula 1 may include one or more compounds selected from the group consisting of compounds represented by the following chemical formulas 2 to 5. [Chemical formula 2] [ka] [Chemical formula 3] [ka] [Chemical formula 4] [ka] [Chemical formula 5] [ka]

[0016] In the present invention, the compound represented by Chemical Formula 1 may be contained in an amount of 20 to 60% by weight based on the total weight of the monomers used in the polymerization of the acrylic copolymer.

[0017] In the present invention, the pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition may have a biomass ratio of 20% or more as measured according to ASTM D6866.

[0018] In the present invention, the pressure-sensitive adhesive composition may further comprise one or more selected from the group consisting of a crosslinking agent, a surfactant, an adhesion promoter, and an anti-aggregation agent.

[0019] The present invention also relates to a pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition.

[0020] Furthermore, the present invention relates to a display comprising the pressure-sensitive adhesive sheet. [Effects of the Invention]

[0021] The present invention can provide a pressure-sensitive adhesive composition that is environmentally friendly and has excellent durability by including an acrylic copolymer polymerized by mixing a biomass-derived monomer.

[0022] Furthermore, the present invention can provide a pressure-sensitive adhesive sheet that uses environmentally friendly materials and does not deform even in high-temperature and high-humidity environments.

[0023] Furthermore, the present invention can provide an environmentally friendly yet highly reliable display. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet, and a display that contain an acrylic copolymer polymerized by mixing a biomass-derived monomer, and thereby satisfy a biomass content of 20% or more as measured by ASTM D6866, and that are free from curling or bubble formation under high temperature and high humidity environmental conditions and have excellent durability.

[0025] Biomass is a general term for plants that synthesize organic matter using solar energy, and animals and microorganisms that feed on them, as well as secondary products and wastes derived from these organisms. Compounds derived from biomass contain radioactive carbon isotopes ( 14 C), and radioactive carbon isotopes ( 14 C) and petroleum-derived compounds that do not contain

[0026] The present invention will be described in more detail below. However, the terms used in this specification are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the term "adhesive sheet" may include an adhesive layer and an adhesive film.

[0027] <Adhesive composition> The pressure-sensitive adhesive composition of the present invention comprises an acrylic copolymer polymerized with a compound of Chemical Formula 1 as a biomass-derived monomer, and may further comprise one or more selected from the group consisting of a crosslinker, a surfactant, an adhesion promoter, and an anti-agglomeration agent, as needed.

[0028] Acrylic Copolymer The acrylic copolymer contained in the pressure-sensitive adhesive composition of the present invention is polymerized containing a biomass-derived monomer, and is characterized by including an acrylic copolymer polymerized containing a compound represented by the following Chemical Formula 1: [Chemical formula 1] [ka] In the above formula 1, R 1 is hydrogen or a methyl group, and R 2 is a hydrocarbon group derived from biomass with 10 to 100 carbon atoms.

[0029] The biomass-derived hydrocarbon group is not particularly limited as long as it is derived from biomass, and may include saturated or unsaturated hydrocarbon groups, and may include linear or alicyclic hydrocarbon groups.

[0030] Examples of the saturated or unsaturated chain hydrocarbon group include alkyl groups such as a decyl group, an undecyl group, and a dodecyl group; branched alkyl groups such as an isodecyl group, a sec-decyl group, a tert-decyl group, an isoundecyl group, a sec-undecyl group, a tert-undecyl group, an isododecyl group, a sec-dodecyl group, and a tert-dodecyl group; and alkenyl groups containing a double bond such as a vinyl group, an allyl group, and a butadienyl group.

[0031] The saturated or unsaturated alicyclic hydrocarbon group includes monocyclic and polycyclic alicyclic hydrocarbon groups, such as a cycloalkyl group, a cycloalkenyl group containing a double bond, and an adamantyl group.

[0032] In the above formula 1, R 2 is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms, and can include a group that is a combination of the saturated or unsaturated chain or alicyclic hydrocarbon groups. Examples of such combinations include a combination of an alkyl group and an alkenyl group, a combination of an alkyl group and a cycloalkyl group, a combination of an alkyl group and a cycloalkenyl group, and a combination of a cycloalkyl group and a cycloalkenyl group.

[0033] The substituent R 2 is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms, and may preferably be a hydrocarbon group derived from a fatty acid produced from an animal or plant, or may be a hydrocarbon group derived from an unsaturated fatty acid derived from pine resin of a pine tree.

[0034] That is, the compound represented by Chemical Formula 1 may be a compound obtained by (meth)acrylating a compound derived from a rosin-based compound, or preferably a compound obtained by (meth)acrylating a compound derived from rosin.

[0035] In one embodiment, the compound represented by Formula 1 may include a substituent R 2 The precursor compound of the above, that is, a compound having a functional group such as a hydroxy group at the end of a hydrocarbon group derived from biomass having 10 to 100 carbon atoms, may be produced by (meth)acrylating.

[0036] . More specifically, the chemical formula 1 may include one or more compounds selected from the group consisting of compounds represented by the following chemical formulas 2 to 5. [Chemical formula 2] [ka] [Chemical formula 3] [ka] [Chemical formula 4] [ka] [Chemical formula 5] [ka]

[0037] The compound represented by the following Chemical Formula 1 may be contained in an amount of 20 to 60 wt % based on the total weight of the monomers used in the polymerization of the acrylic copolymer. When this content range is satisfied, the target biomass content can be achieved, and there is an advantage in that durability under high temperature and high humidity conditions is not reduced and reliability is excellent.

[0038] The acrylic copolymer of the present invention may be polymerized by further including at least one selected from the group consisting of alkyl (meth)acrylate, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer in addition to the compound represented by Chemical Formula 1.

[0039] The alkyl (meth)acrylate is not particularly limited, and the term "(meth)acrylate" refers to both acrylate and methacrylate.

[0040] Specific examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (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 phenoxyethyl (meth)acrylate.

[0041] The alkyl (meth)acrylate may be contained in an amount of 10 to 70 wt % based on the total weight of the monomers used in the polymerization of the acrylic copolymer, and if the content range is satisfied, it is preferable in terms of improving adhesive strength and durability.

[0042] Examples of the carboxy group-containing monomer include monovalent acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate; divalent acids such as maleic acid, itaconic acid, and fumaric acid, and monoalkyl esters thereof; ring-opening adducts of succinic anhydride with 2-hydroxyalkyl (meth)acrylates having an alkyl group with 2 to 3 carbon atoms; ring-opening adducts of succinic anhydride with hydroxyalkylene glycol (meth)acrylates having an alkylene group with 2 to 4 carbon atoms; and compounds obtained by ring-opening addition of succinic anhydride to caprolactone adducts of 2-hydroxyalkyl (meth)acrylates having an alkyl group with 2 to 3 carbon atoms. Of these, (meth)acrylic acid is preferred.

[0043] The carboxyl group-containing monomer may be contained in an amount of 0.01 to 10 wt % based on the total weight of the monomers used in the polymerization of the acrylic copolymer, and when the content range is satisfied, it is preferable in terms of cohesion and durability.

[0044] Examples of the hydroxy group-containing monomer 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 alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, and 2-acryloyloxyethyl-2-hydroxyethyl phthalate.

[0045] More specifically, the hydroxyl group-containing monomer may include a compound represented by the following chemical formula 6: [Chemical formula 6] [ka] In the above formula 6, R 3 is hydrogen or a methyl group, and R 4 is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms.

[0046] The biomass-derived hydrocarbon group is not particularly limited as long as it is derived from biomass, as described in Chemical Formula 1 above, and may include saturated or unsaturated hydrocarbon groups and may include linear or alicyclic hydrocarbon groups.

[0047] In the above formula 6, R 4is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms, and may be a compound obtained by (meth)acrylating a compound derived from rosin containing a hydroxy group.

[0048] In one embodiment, the compound represented by Formula 6 is a compound represented by the substituent R 4 The precursor compound of the above, that is, a compound having a functional group such as a hydroxy group at the end of a hydrocarbon group derived from biomass having 10 to 100 carbon atoms, may be produced by (meth)acrylating.

[0049] The compound of Chemical Formula 6 may be, for example, a compound represented by Chemical Formula 7 below. [Chemical formula 7] [ka]

[0050] The hydroxy group-containing monomer may be contained in an amount of 0.01 to 20% by weight based on the total weight of the monomers used in the polymerization of the acrylic copolymer, and if the content range is satisfied, it is preferable in terms of improving the degree of crosslinking of the polymer.

[0051] In addition, the acrylic monomer of the present invention may be polymerized by further including a conventional acrylic monomer in addition to the compound represented by Chemical Formula 1, alkyl (meth)acrylate, carboxyl group-containing monomer, and hydroxyl group-containing monomer.

[0052] The common acrylic monomer may include at least one selected from the group consisting of a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, a cyano group-containing monomer, a vinyl ester monomer, an aromatic vinyl monomer, an acid anhydride group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, an imide group-containing monomer, an epoxy group-containing monomer, and an ether group-containing monomer.

[0053] Examples of the sulfonic acid group-containing monomer include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid, and sodium vinylsulfonate.

[0054] The phosphate group-containing monomer may, for example, be 2-hydroxyethyl acryloyl phosphate.

[0055] Examples of the cyano group-containing monomer include (meth)acrylonitrile.

[0056] Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, and vinyl laurate.

[0057] Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

[0058] Examples of the acid anhydride-containing monomer include maleic anhydride, itaconic anhydride, and anhydrides thereof.

[0059] Examples of the amide group-containing monomer include (meth)acrylamide, N-isopropylacrylamide, N-tertiary butylacrylamide, 3-hydroxypropyl(meth)acrylamide, 4-hydroxybutyl(meth)acrylamide, 6-hydroxyhexyl(meth)acrylamide, 8-hydroxyoctyl(meth)acrylamide, and 2-hydroxyethylhexyl(meth)acrylamide.

[0060] Examples of the amino group-containing monomer include N,N-(dimethylamino)ethyl (meth)acrylate, N,N-(diethylamino)ethyl (meth)acrylate, and N,N-(dimethylamino)propyl (meth)acrylate. Examples of the imide group-containing monomer include cyclohexylmaleimide and isopropylmaleimide.

[0061] Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate.

[0062] Examples of the ether group-containing monomer include 3-methoxybutyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, methoxypolyethylene glycol acrylate having an added mole number of oxyethylene in the range of 1 to 15, ethoxy-diethylene glycol (meth)acrylate, and ethyl carbitol (meth)acrylate.

[0063] The acrylic copolymer of the present invention may contain a common acrylic monomer in an amount of 40 to 80 wt % based on the total weight of the monomers used in the polymerization of the acrylic copolymer, in addition to the compound represented by Chemical Formula 1, alkyl (meth)acrylate, carboxyl group-containing monomer, and hydroxyl group-containing monomer. When the content range is satisfied, it may be advantageous in terms of adhesive strength and durability.

[0064] The acrylic copolymer may further contain other monomers commonly used in the technical field to which the present invention pertains, in addition to the above-mentioned monomers, within the range that does not reduce adhesive strength, for example, in an amount of 10 wt % or less based on the total weight of the acrylic copolymer.

[0065] The acrylic copolymer may have a weight-average molecular weight (polystyrene equivalent; Mw) of 500,000 to 2,000,000, more preferably 700,000 to 1,700,000, as measured by gel permeation chromatography (GPC). If the weight-average molecular weight of the acrylic copolymer is less than 500,000, the chain structure of the adhesive film after UV polymerization and curing is simple and short, resulting in reduced reliability, such as the generation of bubbles, and reduced durability due to discoloration. If the weight-average molecular weight of the acrylic copolymer exceeds 2,000,000, the viscosity of the adhesive resin composition during production of the adhesive film is excessively high, necessitating the dilution of a large amount of monomer to achieve the appropriate viscosity required for production. This may result in high energy requirements during UV polymerization and curing, or residual unreacted monomer.

[0066] The method for producing the acrylic copolymer is not particularly limited, and may be any method commonly used in the technical field to which the present invention pertains, such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, or UV polymerization, and preferably solution polymerization or UV polymerization.

[0067] additives The additives can be selectively added as needed, and can include, for example, one or more selected from the group consisting of a crosslinking agent, a surfactant, an adhesion promoter, and an anti-aggregation agent.

[0068] The pressure-sensitive adhesive composition of the present invention may further contain a crosslinking agent to enhance the cohesive strength of the pressure-sensitive adhesive.

[0069] The crosslinking agent is not particularly limited as long as it is a component that can strengthen the cohesive strength of the pressure-sensitive adhesive by appropriately crosslinking the acrylic copolymer.

[0070] Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, etc. These may be used alone or in combination of two or more.

[0071] Examples of the isocyanate crosslinking agent include polyfunctional isocyanate compounds such as toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate, and naphthalene diisocyanate, as well as compounds obtained by reacting the polyfunctional isocyanate compounds with polyol compounds such as trimethylolpropane, etc. These may be used alone or in combination of two or more.

[0072] Examples of the epoxy crosslinking agent include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N,N,N',N'-tetraglycidylethylenediamine, and glycerin diglycidyl ether, which can be used alone or in combination of two or more.

[0073] Examples of the oxazoline-based crosslinking agent include copolymers polymerized containing at least one monomer containing an oxazoline group, such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. These may be used alone or in combination of two or more.

[0074] Examples of the aziridine crosslinking agent include N,N'-toluene-2,4-bis(1-aziridinecarboxamide), N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), triethylenemelamine, bisisophthaloyl-1-(2-methylaziridine), and tri-1-aziridinylphosphine oxide, which can be used alone or in combination of two or more.

[0075] Examples of the metal chelate crosslinking agent include compounds in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium, and / or vanadium is coordinated with acetylacetone or ethyl acetoacetate, etc. These may be used alone or in combination of two or more.

[0076] The crosslinking agent is preferably contained in an amount of 0.1 to 1 wt %, more preferably 0.1 to 0.5 wt %, based on the total weight of the acrylic copolymer. If the content of the crosslinking agent is less than 0.1 wt %, the adhesive strength or cohesive strength of the pressure-sensitive adhesive composition may be slightly reduced. If the content of the crosslinking agent is more than 1 wt %, the compatibility may be slightly reduced, causing surface migration, and the crosslinking reaction may proceed excessively, resulting in a slightly reduced adhesive strength.

[0077] The surfactant can be used to further improve the film formation of the colored curable resin composition, and silicone-based, fluorine-based, ester-based, cationic, anionic, nonionic, amphoteric surfactants, etc. can be preferably used.

[0078] Examples of commercially available silicone surfactants include DC3PA, DC7PA, SH-11PA, SH-21PA, and SH-8400 manufactured by Dow Corning Toray Silicones, and TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, and TSF-4452 manufactured by GE Toshiba Silicones.

[0079] Examples of the fluorine-based surfactant include commercially available products such as Megapis F-470, F-471, F-475, F-482, F-489 and F-554 manufactured by Dainippon Ink and Chemicals, Inc.

[0080] Other commercially available products that can be used include KP (Shin-Etsu Chemical Co., Ltd.), POLYFLOW (Kyoeisha Chemical Co., Ltd.), EFTOP (Tochem Products), MEGAFAC (Dainippon Ink and Chemicals, Inc.), Flourad (Sumitomo 3M Limited), Asahi Guard, and Surflon (all Asahi Glass Co., Ltd.), SOLSPERSE (Lubrisol), EFKA (EFKA Chemicals), PB821 (Ajinomoto Co., Inc.), and the Disperbyk series (BYK-chemi).

[0081] The surfactants exemplified above can be used alone or in combination of two or more.

[0082] The type of adhesion promoter is not particularly limited, and specific examples of usable adhesion promoters include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane.

[0083] The type of the anti-aggregation agent is not particularly limited, but specific examples that can be used include sodium polyacrylate.

[0084] The additives exemplified above can be used alone or in combination of two or more. The additives may be contained in an amount of usually 0.01 to 5 wt %, preferably 0.05 to 2 wt %, based on the total weight of the pressure-sensitive adhesive composition.

[0085] <Adhesive sheets and displays> The present invention provides a pressure-sensitive adhesive sheet manufactured from the above-mentioned pressure-sensitive adhesive composition. To provide the pressure-sensitive adhesive sheet of the present invention, the structures and manufacturing methods generally used for manufacturing pressure-sensitive adhesive layers, pressure-sensitive adhesive films, and pressure-sensitive adhesive sheets in the same field can be used, except that the pressure-sensitive adhesive sheet contains the above-mentioned pressure-sensitive adhesive composition.

[0086] The present invention also provides a display comprising the above-mentioned PSA sheet. The display of the present invention may have any configuration commonly known in the technical field, as long as it comprises the PSA composition and PSA sheet of the present invention.

[0087] The pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition of the present invention may have a biomass ratio of 20% or more as measured by ASTM D6866.

[0088] Furthermore, the pressure-sensitive adhesive sheet is excellent in durability, preventing the occurrence of bubbles or peeling even in harsh environments such as high temperatures of 50 to 100°C and high humidity of 70% or more.

[0089] When a pressure-sensitive adhesive sheet satisfying the biomass content is applied to a display, it is possible to provide a display with excellent reliability without reducing durability, and it is preferable in that no environmental costs are incurred. [Example]

[0090] Specific examples for carrying out the present invention will be described below, but the present invention is not limited to the following contents and can be appropriately modified to the extent required in the ordinary field.

[0091] <Production Example: Production of Acrylic Copolymer> Manufacturing Example 1 A 1L reactor was charged with 17.8 parts by weight of butyl acrylate (BA), 40 parts by weight of the compound of Formula 2, 30 parts by weight of methyl acrylate (MA), 8 parts by weight of phenoxyethyl acrylate (PEA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA), and 0.2 parts by weight of acrylic acid (AA), followed by 100 parts by weight of ethyl acetate (EAc) as a solvent. Nitrogen gas was purged for 1 hour to remove oxygen, and the temperature was maintained at 80°C. After uniformly mixing the monomer mixture, 0.07 parts by weight of azobisisobutyronitrile (AIBN) was added as a reaction initiator. The reaction was continued for 8 hours to produce an acrylic copolymer (weight average molecular weight: 1.41 million, PDI: 4.2).

[0092] Manufacturing Examples 2 to 8 An acrylic copolymer was produced in the same manner as in Production Example 1, with the composition shown in Table 1 below.

[0093] [Table 1]

[0094] Compound of Chemical Formula 2: Octadecenyl acrylate (HANIN FINE CHEM) Compound of Chemical Formula 3: Abietinyl acrylate (HANIN FINE CHEM) Compound of Chemical Formula 4: Abietinyl acrylate (HANIN FINE CHEM) Compound of Chemical Formula 5: Rosinyl acrylate (HANIN FINE CHEM) Compound of Chemical Formula 7: Hydroxyrosinylpropyl methacrylate (HANIN FINE CHEM) BA: butyl acrylate, Sigma-Aldrich MA: methyl acrylate, Sigma-Aldrich PEA: Phenoxyethyl acrylate, Sigma-Aldrich 2-HEA: 2-hydroxyethyl acrylate, Sigma-Aldrich AA: acrylic acid, Sigma-Aldrich

[0095] <Examples and Comparative Examples: Production of Pressure-Sensitive Adhesive Compositions and Pressure-Sensitive Adhesive Sheets> An adhesive composition was prepared according to the formulation in Table 2 below, and applied to a thickness of 50 μm on a 50 μm release film coated with a silicone release agent. The composition was then dried at 110°C for 5 minutes, and then laminated on a release film to prepare an adhesive sheet.

[0096] [Table 2]

[0097] A: D-103, Mitsui Chemical B:KBM403, Shin-Etsu Chemical

[0098] Experimental example The physical properties of the pressure-sensitive adhesive sheets produced in Examples 1 to 7 and Comparative Example 1 were measured by the following methods, and the results are shown in Table 3 below.

[0099] (1) Measurement of biomass content The biomass content of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet was measured in accordance with ASTM D6866. <Evaluation criteria> ◎: Biomass content 30% or more ○: Biomass ratio 25% or more and less than 30% △: Biomass content is between 20% and 25% ×: Biomass content less than 20%

[0100] (2) Durability evaluation The adhesive sheets prepared in Examples 1 to 7 and Comparative Example 1 were placed between a polarizing plate and glass, and then stored at 80°C and 60°C with a relative humidity of 90% for 500 hours. After that, the adhesive sheets were visually inspected to see if any bubbles or peeling occurred. <Evaluation criteria> ◎: No bubbles or peeling ○: Less than 5 bubbles or peeling △: 5 or more bubbles or peeling, but less than 10 ×: 10 or more bubbles or peeling

[0101] (3) Adhesion evaluation The prepared adhesive sheet was cut into a length of 25 mm and a width of 100 mm. After removing the release film, the exposed adhesive layer was attached to a glass substrate (#1737, Corning) at a pressure of 0.25 MPa. The sheet was then autoclaved at 50°C and 5 atmospheres for 20 minutes to prepare a test specimen. To measure room temperature adhesive strength, the prepared test specimen was left at 23°C and 50% RH for 24 hours. The adhesive sheet was peeled from the glass substrate at a peeling speed of 300 mm / min and a peeling angle of 180° using a universal tensile tester (UTM, Instron) to measure room temperature adhesive strength.

[0102] [Table 3]

[0103] Referring to Table 3, the pressure sensitive adhesive sheets prepared using the pressure sensitive adhesive compositions according to Examples 1 to 5 of the present invention have excellent biomass content, maintain excellent adhesive strength, and are also very durable.

[0104] In addition, in the case of Example 7, in which an acrylic monomer copolymerized with the compound represented by Formula 6 of the present invention was used as a hydroxy-containing monomer, excellent results were obtained in terms of both biomass content and durability.

[0105] On the other hand, in the case of Example 6, which contains the compound represented by Chemical Formula 1 of the present invention but the content exceeds the range of the present invention, it can be seen that the biomass degree is insufficient.

[0106] In contrast, in the case of Comparative Example 1, which does not contain the compound represented by Chemical Formula 1 of the present invention, the biomass degree is 0, and it can be confirmed that the durability at high temperature and high humidity is also insufficient.

Claims

1. A pressure-sensitive adhesive composition comprising an acrylic copolymer polymerized with a compound represented by the following Chemical Formula 1: [Chemical formula 1] 【Chemistry 1】 (In the above Chemical Formula 1, R １ is hydrogen or a methyl group, R ２ is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms.

2. The pressure-sensitive adhesive composition according to claim 1, wherein the acrylic copolymer is polymerized by further comprising at least one selected from the group consisting of alkyl (meth)acrylate, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer.

3. The pressure-sensitive adhesive composition according to claim 2, wherein the hydroxy group-containing monomer comprises a compound represented by the following chemical formula 6: [Chemical formula 6] 【Chemistry 2】 (In the above Chemical Formula 6, R ３ is hydrogen or a methyl group, R ４ is a hydrocarbon group derived from biomass having 10 to 100 carbon atoms.

4. The pressure-sensitive adhesive composition according to claim 1, wherein the compound represented by Chemical Formula 1 includes one or more compounds selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 5: [Chemical formula 2] 【Transformation 3】 [Chemical formula 3] 【Chemistry 4】 [Chemical formula 4] 【Transformation 5】 [Chemical formula 5] 【Transformation 6】

5. The pressure-sensitive adhesive composition according to claim 1, wherein the compound represented by Chemical Formula 1 is contained in an amount of 20 to 60 wt % based on the total weight of the monomers used in polymerization of the acrylic copolymer.

6. The pressure-sensitive adhesive composition according to claim 1 , wherein a pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition has a biomass content of 20% or more as measured by ASTM D6866.

7. The pressure-sensitive adhesive composition according to claim 1 , further comprising at least one selected from the group consisting of a crosslinking agent, a surfactant, an adhesion promoter, and an anti-aggregation agent.

8. A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 7.

9. A display comprising the pressure-sensitive adhesive sheet according to claim 8.

Images