Pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and display including the same

Abstract

To provide: a pressure-sensitive adhesive composition that is environmentally friendly and has excellent durability and bending properties, and that exhibits excellent reliability even in high-temperature and high-humidity environments; a pressure-sensitive adhesive sheet produced therefrom; and a display including the same.SOLUTION: A pressure-sensitive adhesive composition comprises an acrylic copolymer polymerized containing a compound represented by the Chemical Formula 1 in the figure. (In Chemical Formula 1, R1 is hydrogen or a methyl group, and R2 is a biomass-derived hydrocarbon group having 1 to 9 carbon atoms.)SELECTED DRAWING: None

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] The display industry uses many optically clear pressure sensitive adhesives to mount touch panels or touch screens or to achieve high brightness and high 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 from occurring 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 may result in huge environmental costs due to international agreements that strictly regulate greenhouse gas emissions.

[0005] Therefore, development of environmentally friendly materials that can replace existing petrochemical products is underway.

[0006] In particular, in fields that require precise dimensional stability, such as electronic materials, durability and reliability must be ensured to prevent bending due to curling, bubbles, or peeling under harsh conditions such as high temperature and high humidity, as mentioned above.

[0007] Furthermore, due to European environmental regulations, it is necessary to develop a pressure-sensitive adhesive composition that is excellent in durability and bending properties while also using environmentally friendly materials.

[0008] 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 is still a problem that it is insufficient in preventing bending, bubbles, or peeling under harsh conditions such as high temperature and high humidity. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent No. 10-1535564 Summary of the Invention [Problem to be solved by the invention]

[0010] 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 and bending properties.

[0011] The present invention also provides an adhesive sheet that is environmentally friendly and has excellent reliability and bending properties even in high temperature and high humidity environments, and a display including the same.

[0012] 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]

[0013] 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:

[0014] [Chemical formula 1]

[0015] [ka]

[0016] In the above formula 1, R1 is hydrogen or a methyl group, and R2 is a hydrocarbon group derived from biomass having 1 to 9 carbon atoms.

[0017] The compound represented by Chemical Formula 1 may include one or more compounds selected from the group consisting of compounds represented by Chemical Formulas 2 and 3 below.

[0018] [Chemical formula 2]

[0019] [ka]

[0020] [Chemical formula 3]

[0021] [ka]

[0022] The compound represented by Chemical Formula 1 may include both the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3.

[0023] In this case, the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3 may be contained in a ratio of 1:10 to 10:1.

[0024] The compound represented by Chemical Formula 1 may be contained in an amount of 30 to 80% by weight based on the total weight of the monomers used in the polymerization of the acrylic copolymer.

[0025] The pressure-sensitive adhesive composition of the present invention may further contain a compound represented by the following chemical formula 4.

[0026] [Chemical formula 4]

[0027] [ka]

[0028] In Chemical Formula 4, Ra to Rc are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroarylene group having 6 to 30 carbon atoms, and any two of Ra to Rc are bonded together to form a ring system.

[0029] The compound represented by Chemical Formula 4 may include one or more compounds selected from the group consisting of compounds represented by Chemical Formulas 5 and 6 below.

[0030] [Chemical formula 5]

[0031] [ka]

[0032] [Chemical formula 6]

[0033] [ka]

[0034] The compound represented by Chemical Formula 4 may be contained in an amount of 1.0 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer.

[0035] The pressure-sensitive adhesive composition of the present invention may further contain one or more silane coupling agents selected from the group consisting of compounds represented by the following chemical formulas 7 and 8.

[0036] [Chemical formula 7]

[0037] [ka]

[0038] In Chemical Formula 7, R3 is an alkyl group having 1 to 12 carbon atoms, R4 is each independently a divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, and R5 to R7 are each independently hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

[0039] [Chemical formula 8]

[0040] [ka]

[0041] In the formula 8, R8 is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, R9 is a divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, and R 10 ~R 12 are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

[0042] The silane coupling agent may be contained in an amount of 0.01 to 3 parts by weight based on 100 parts by weight of the acrylic copolymer.

[0043] The PSA sheet formed from the PSA composition may have a biomass ratio of 30% or more, calculated according to the following formula 1 in accordance with ASTM D6866.

[0044] [Formula 1] Biomass ratio (%) = number of carbon atoms derived from biomass / total number of carbon atoms x 100 The pressure-sensitive adhesive composition may further contain one or more selected from the group consisting of a crosslinking agent, an antistatic agent, a surfactant, an adhesion promoter, and an anti-aggregation agent.

[0045] The present invention also relates to a pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition. The present invention also relates to a display including the pressure-sensitive adhesive sheet. [Effects of the Invention]

[0046] The present invention provides an environmentally friendly pressure-sensitive adhesive composition having excellent durability and bending properties by including an acrylic copolymer polymerized by mixing a biomass-derived monomer.

[0047] Furthermore, the present invention can provide an adhesive sheet and a display including the same that use environmentally friendly materials and have excellent reliability and bending properties even in high temperature and high humidity environments. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet, and a display, which contain an acrylic copolymer polymerized by mixing a biomass-derived monomer, have a biomass content of 30% or more as measured by ASTM D6866, and do not curl or bubble under high temperature and high humidity conditions, and therefore have excellent durability, reliability, and bending properties.

[0049] Biomass is a collective term for plants that synthesize organic matter using solar energy, and the animals and microorganisms that feed on them, as well as the secondary products and waste products 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

[0050] Therefore, the biomass degree of the PSA sheet formed from the PSA composition is determined by the radioactive carbon isotope ( 14 C), specifically, it can be measured in accordance with ASTM D6866.

[0051] The biomass degree of the PSA composition of the present invention and the PSA sheet comprising the same can be calculated by the following formula 1, which can distinguish between biomass-derived carbon and fossil fuel-derived carbon according to ASTM D6866, and the biomass degree thus calculated may be 30% or more.

[0052] [Formula 1] Biomass ratio (%) = number of carbon atoms derived from biomass / total number of carbon atoms x 100 According to the present invention, by calculating the biomass degree using the above formula 1, the biomass degree can be determined more accurately and easily.

[0053] 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.

[0054] <Adhesive composition> The pressure-sensitive adhesive composition of the present invention includes an acrylic copolymer polymerized with a biomass-derived monomer, the compound represented by Chemical Formula 1. To impart adhesiveness, the pressure-sensitive adhesive composition may further include a compound represented by Chemical Formula 4 and / or a silane coupling agent having triethoxysilane. If necessary, the pressure-sensitive adhesive composition may further include one or more selected from the group consisting of a crosslinker, a surfactant, an adhesion promoter, and an anti-agglomeration agent.

[0055] Acrylic Copolymer The acrylic copolymer contained in the pressure-sensitive adhesive composition of the present invention is polymerized using a biomass-derived monomer, and is characterized by including an acrylic copolymer polymerized using a compound represented by the following Chemical Formula 1:

[0056] [Chemical formula 1]

[0057] [ka]

[0058] In the above formula 1, R1 is hydrogen or a methyl group, and R2 is a hydrocarbon group derived from biomass having 1 to 9 carbon atoms.

[0059] The biomass-derived hydrocarbon group is not particularly limited as long as it is derived from biomass, that is, from plants that synthesize organic substances by receiving solar energy, and from living organisms such as animals and microorganisms that feed on these plants. It can be obtained inexpensively and easily by alcoholizing or esterifying saturated fatty acids or unsaturated fatty acids extracted from living organisms such as plants and animals.

[0060] The biomass-derived hydrocarbon groups of the present invention can include saturated or unsaturated hydrocarbon groups, and can include open-chain or alicyclic hydrocarbon groups.

[0061] The saturated or unsaturated chain hydrocarbon group may be a straight or branched chain, and examples thereof include alkyl groups and alkenyl groups.

[0062] 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.

[0063] The hydrocarbon group may also include a group that combines saturated or unsaturated chain or alicyclic hydrocarbon groups, such as a combination of an alkyl group and an alkenyl group, an alkyl group and a cycloalkyl group, an alkyl group and a cycloalkenyl group, or a cycloalkyl group and a cycloalkenyl group.

[0064] More specifically, the compound represented by Chemical Formula 1 may include one or more compounds selected from the group consisting of compounds represented by Chemical Formulas 2 and 3 below.

[0065] [Chemical formula 2]

[0066] [ka]

[0067] [Chemical formula 3]

[0068] [ka]

[0069] Furthermore, the compound represented by Chemical Formula 1 may include both the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3. In this case, flexibility is increased, which is more advantageous for bending properties.

[0070] In this case, the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3 may be included in a ratio of 1:10 to 10:1, more preferably 1:5 to 5:1, which is preferable in terms of improving bending properties.

[0071] The compound represented by Chemical Formula 1 may be included in an amount of 30 to 80 wt % based on the total weight of the monomers used in the polymerization of the acrylic copolymer. When the content range is satisfied, a desired biomass content can be achieved, and durability and bending properties under high temperature and humidity conditions are not reduced, resulting in excellent reliability.

[0072] 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 hydroxy group-containing monomer, in addition to the compound represented by Chemical Formula 1.

[0073] The alkyl (meth)acrylate is not particularly limited, and the term "(meth)acrylate" refers to both acrylate and methacrylate.

[0074] 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.

[0075] 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, which is preferable in terms of improving adhesive strength and durability.

[0076] Examples of the carboxyl group-containing monomer include monobasic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate; dibasic acids such as maleic acid, itaconic acid, and fumaric acid, and their monoalkyl esters; ring-opening adducts of 2-hydroxyalkyl (meth)acrylates having an alkyl group with 2 to 3 carbon atoms with numerous succinic acids; ring-opening adducts of hydroxyalkylene glycol (meth)acrylates having an alkylene group with 2 to 4 carbon atoms with numerous succinic acids; and compounds obtained by ring-opening addition of caprolactone adducts of 2-hydroxyalkyl (meth)acrylates having an alkyl group with 2 to 3 carbon atoms with numerous succinic acids. Of these, (meth)acrylic acid is preferred.

[0077] 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, which is preferable in terms of cohesive strength and durability when the content is within this range.

[0078] 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.

[0079] Furthermore, the acrylic monomer of the present invention may be polymerized by further containing a common acrylic monomer in addition to the compound represented by Chemical Formula 1, alkyl (meth)acrylate, carboxyl group-containing monomer, and hydroxy group-containing monomer, and 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.

[0080] 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.

[0081] Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate, and examples of the cyano group-containing monomer include (meth)acrylonitrile.

[0082] Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, and vinyl laurate, and examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

[0083] Examples of the acid myristic compound-containing monomer include myristic maleic acid and myristic itaconic acid.

[0084] 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.

[0085] 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.

[0086] Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate, and 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.

[0087] 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 monomers used in the acrylic copolymer polymerization.

[0088] 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 within 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 the production of the adhesive film is so high that a large amount of monomer dilution is required to achieve the appropriate viscosity required for production. This may result in high energy consumption during UV polymerization and curing, or residual unreacted monomer.

[0089] The method for producing the acrylic copolymer is not particularly limited, and may be, for example, a 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.

[0090] Compound represented by chemical formula 4 The pressure-sensitive adhesive composition of the present invention may further include a compound represented by the following Chemical Formula 4.

[0091] [Chemical formula 4]

[0092] [ka]

[0093] R a to R c are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroarylene group having 6 to 30 carbon atoms, and any two of R a to R c are bonded together to form a ring system.

[0094] The term "substituted" means that at least one hydrogen atom in the chemical structure is replaced with another terminal substituent. Exemplary substituents that may be present at the "substituted" position include nitro (-NO2), cyano (-CN), hydroxyl (-OH), oxo (=O), amino (-NH2), alkylamino having 1 to 6 carbon atoms, formyl (-C(=O)H), alkyl ester having 2 to 6 carbon atoms (-C(=O)O-alkyl or -OC(=O)-alkyl), aryl ester having 7 to 13 carbon atoms (-C(=O)O-aryl or -OC(=O)-aryl), and the like. Examples include, but are not limited to, cycloalkyl of 3 to 12 carbon atoms, cycloalkenyl of 5 to 18 carbon atoms, heterocycloalkenyl of 2 to 18 carbon atoms, aryl of 6 to 12 carbon atoms having at least one aromatic ring, arylalkyl of 7 to 19 carbon atoms having 1 to 3 separate or fused rings and 6 to 18 ring carbon atoms, arylalkoxy of 1 to 3 separate or fused rings and 6 to 18 ring carbon atoms, alkylaryl of 7 to 12 carbon atoms, heterocycloalkyl of 3 to 12 carbon atoms, or heteroaryl of 3 to 12 carbon atoms.

[0095] Any two of the R a to R c may be selectively linked together to form a substituted or unsubstituted ring system, and may be linked via a single bond or a divalent linking group.

[0096] The ring system may include aliphatic or aromatic rings and may be in the form of multiple linked rings.

[0097] The compound represented by Chemical Formula 4 may include, for example, one or more compounds selected from the group consisting of compounds represented by Chemical Formulas 5 and 6 below.

[0098] [Chemical formula 5]

[0099] [ka]

[0100] [Chemical formula 6]

[0101] [ka]

[0102] The adhesive composition of the present invention can improve adhesive strength by further containing the compound represented by Chemical Formula 4.

[0103] The compound represented by Formula 4 can be mixed with the acrylic copolymer to provide a chain extension effect, thereby improving elasticity and adhesive strength, and thus improving bending properties.

[0104] In particular, when a crosslinking agent is mixed to increase the durability of the acrylic copolymer, adhesive strength may be somewhat reduced. However, when the compound represented by Chemical Formula 4 is mixed with the acrylic copolymer and the crosslinking agent, the chain is extended, maintaining elasticity and the degree of crosslinking, thereby improving adhesive strength and bending properties.

[0105] The compound represented by Chemical Formula 4 may be included in an amount of 1.0 to 10 parts by weight, preferably 1.0 to 8.0 parts by weight, based on 100 parts by weight of the acrylic copolymer.

[0106] If the content of the compound represented by Formula 4 is less than 1.0 part by weight per 100 parts by weight of the acrylic copolymer, the effect of addition is minimal and there is no effect in improving adhesive strength and bending properties.If the content exceeds 10 parts by weight per 100 parts by weight of the acrylic copolymer, excessive chain elongation may cause a decrease in cohesive strength within the adhesive, which may lead to breakdown of adhesive cohesion and decrease in adhesive strength.

[0107] silane coupling agent The pressure-sensitive adhesive composition of the present invention may further contain one or more silane coupling agents selected from the group consisting of compounds represented by the following chemical formulas 7 and 8.

[0108] One or more silane coupling agents selected from the group consisting of compounds represented by Chemical Formulas 7 and 8 can increase the compatibility of the pressure-sensitive adhesive composition, improve adhesive strength, and suppress bubble generation, lifting, and breakage of the pressure-sensitive adhesive layer.

[0109] The silane coupling agent may contain a nitrogen atom or a sulfur atom, and in this case, it may provide adhesive durability and reliability even when left for a long period of time under heat-resistant and moist heat-resistant conditions.

[0110] [Chemical formula 7]

[0111] [ka]

[0112] In Chemical Formula 7, R3 is an alkyl group having 1 to 12 carbon atoms, R4 is each independently a divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, and R5 to R7 are each independently hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

[0113] [Chemical formula 8]

[0114] [ka]

[0115] In the formula 8, R8 is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, R9 is a divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, and R 10 ~R 12 are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

[0116] Specifically, it is preferable that the silane coupling agent has a trimethoxysilane group in order to achieve the object and effect of the present invention.

[0117] The compound represented by Chemical Formula 7 may be, for example, a compound represented by Chemical Formula 7-1 below, and the compound represented by Chemical Formula 8 may be, for example, a compound represented by Chemical Formula 8-1 below.

[0118] [Chemical formula 7-1]

[0119] [ka]

[0120] [Chemical formula 8-1]

[0121] [ka]

[0122] The silane coupling agent may be included in an amount of 0.01 to 3 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the acrylic copolymer, in order to improve the durability and adhesion of the adhesive layer formed from the adhesive composition within this range.

[0123] additives The pressure-sensitive adhesive composition may further contain conventional additives known in the art as needed to adjust adhesive strength, cohesive strength, viscosity, elastic modulus, glass transition temperature, etc., depending on the application. For example, the pressure-sensitive adhesive composition may contain at least one additive selected from the group consisting of a crosslinking agent, an antistatic agent, a surfactant, an adhesion promoter, and an anti-agglomeration agent.

[0124] 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.

[0125] 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.

[0126] Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, metal chelate compounds, etc. These may be used alone or in combination of two or more.

[0127] 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, and 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.

[0128] Examples of the epoxy crosslinking agent include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N,N,N',N'-tetraglycidylethylenediamine, glycerin diglycidyl ether, etc. These may be used alone or in combination of two or more.

[0129] 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-isopropyl-2-oxazoline, 2-isopropyl-4-methyl-2-oxazoline, and 2-isopropyl-5-ethyl-2-oxazoline. These may be used alone or in combination of two or more.

[0130] Examples of the aziridine crosslinking agent include N,N'-toluene-2,4-bis(1-aziridinecarboxamide), N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), triethylenemelamine, bisisoprothaloyl-1-(2-methylaziridine), and tri-1-aziridinylphosphine oxide, which may be used alone or in combination of two or more.

[0131] 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.

[0132] The crosslinking agent may be included in an amount of preferably 0.1 to 1 part by weight, more preferably 0.1 to 0.6 parts by weight, based on 100 parts by weight of the acrylic copolymer. If the content of the crosslinking agent is less than 0.1 part by weight, the adhesive strength or cohesive strength of the pressure-sensitive adhesive composition may be slightly reduced, while if the content exceeds 1 part by weight, the compatibility may be slightly reduced, causing surface migration, and the crosslinking reaction may proceed excessively, resulting in a slightly reduced adhesive strength.

[0133] The pressure-sensitive adhesive composition of the present invention may further include an antistatic agent. The antistatic agent may be an ionic antistatic agent, which includes an ionic salt composed of an anion and a cation, and can impart ionic conductivity to an adhesive layer formed from the pressure-sensitive adhesive composition.

[0134] The ionic antistatic agent may include an alkali metal salt, an ionic liquid, or an ionic solid, and preferably includes an ionic solid.

[0135] The inclusion of an ionic solid as the ionic antistatic agent can improve the stability of the PSA composition against changes over time and the durability of the PSA layer. In addition, the ionic solid has high compatibility with the other components described above, and can maintain high transparency of the PSA composition.

[0136] The cations of the ionic solids can include imidazolium, pyridinium, alkylammonium, alkylpyrrolidium, and / or alkylphosphonium, and the like.

[0137] In some embodiments, the content of the ionic antistatic agent may be 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic copolymer, within this range, the antistatic properties of the adhesive layer may be improved, and the durability of the adhesive layer may be maintained excellent.

[0138] The pressure-sensitive adhesive composition of the present invention can contain a surfactant to further improve film formation, and silicone-based, fluorine-based, ester-based, cationic, anionic, nonionic, amphoteric surfactants and the like are preferably used.

[0139] 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.

[0140] Examples of commercially available fluorine-based surfactants include Megapeace F-470, F-471, F-475, F-482, F-489, and F-554 manufactured by Dainippon Ink and Chemicals, Inc.

[0141] 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 from Asahi Glass Co., Ltd.), SOLSPERSE (Lubrisol), EFKA (EFKA Chemicals), PB821 (Ajinomoto Co., Ltd.), and the Disperbyk series (BYK-chemi).

[0142] The surfactants exemplified above can be used alone or in combination of two or more, and may be contained in an amount of usually 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight, per 100 parts by weight of the adhesive composition.

[0143] The adhesive composition of the present invention may contain an adhesion promoter to enhance adhesion, and may contain an adhesion promoter in an amount of usually 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight, per 100 parts by weight of the adhesive composition.

[0144] The type of the 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.

[0145] The type of the anti-aggregation agent is not particularly limited, but specific examples that can be used include sodium polyacrylate, which may be contained in an amount of usually 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight, per 100 parts by weight of the pressure-sensitive adhesive composition.

[0146] <Adhesive sheets and displays> The present invention provides a pressure-sensitive adhesive sheet manufactured using the above-mentioned pressure-sensitive adhesive composition. To provide the pressure-sensitive adhesive sheet of the present invention, in addition to including the above-mentioned pressure-sensitive adhesive composition, the structures and manufacturing methods generally used for manufacturing pressure-sensitive adhesive layers, pressure-sensitive adhesive films, and pressure-sensitive adhesive sheets in the field can be used.

[0147] The present invention also provides a display comprising the above-mentioned pressure-sensitive adhesive sheet. The display of the present invention may have any configuration commonly known in the art, as long as it comprises the pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet of the present invention.

[0148] The pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition of the present invention may have a biomass ratio of 30% or more, calculated according to the following formula 1 in accordance with ASTM D6866:

[0149] [Formula 1] Biomass ratio (%) = number of carbon atoms derived from biomass / total number of carbon atoms x 100 According to the present invention, by calculating the biomass degree using the above formula 1, the biomass degree can be determined more accurately and easily.

[0150] When the biomass content is satisfied, the adhesive can have an increased content of carbon derived from biomass, and does not increase carbon dioxide in the atmosphere, making it environmentally friendly.

[0151] Furthermore, the pressure-sensitive adhesive sheet manufactured using the pressure-sensitive adhesive composition of the present invention 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 / or high humidity of 70% or more.

[0152] When such a highly durable adhesive sheet is applied to a display, the durability and bending properties are not reduced, making it possible to provide a highly reliable display, and it is preferable in that it does not incur environmental costs.

[0153] Specific examples for carrying out the present invention will be described below, but the present invention is not limited to the following content and may be appropriately modified to the extent required in the ordinary field. [Example]

[0154] <Synthesis Example 1: Compound of Chemical Formula 3> Bio-Butanol (product code W217816, Sigma-Aldrich) and acrylic acid were stirred under an acid catalyst at 80°C for 3 hours and purified. The biomass ratio of the synthesized compound of formula 3, calculated using formula 1 in accordance with ASTM D6866, was 57%.

[0155] <Production Example: Production of Acrylic Copolymer> Manufacturing Example 1 A 1L reactor equipped with a nitrogen gas reflux and a cooling device for easy temperature control was charged with 100 parts by weight of a monomer mixture consisting of 68.8 wt% n-butyl acrylate (BA), 30 wt% methacrylate (MA), 0.2 wt% acrylic acid (AA), and 1.0 wt% 2-hydroxyethyl methacrylate (2-HEMA), followed by 100 parts by weight of ethyl acetate (EA) as a solvent. Nitrogen gas was then introduced for 1 hour to purge the mixture and the temperature was maintained at 62°C. After uniformly mixing the mixture, 0.07 parts by weight of azobisisobutyronitrile (AIBN) was added as a reaction initiator and the mixture was allowed to react for 8 hours to produce an acrylic copolymer with a molecular weight of approximately 1.24 million.

[0156] Production examples 2 to 8 The same production procedure as in Production Example 1 was followed, but an acrylic copolymer was produced according to the composition shown in Table 1 below.

[0157] [Table 1]

[0158] <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, applied to a release film coated with a silicone release agent, and dried at 100°C for 2 minutes to form an adhesive layer with a thickness of 20 μm. A corona-discharge-treated triacetyl cellulose (TAC) film was laminated onto the adhesive layer to prepare an adhesive sheet.

[0159] [Table 2]

[0160] <Experimental Example> The physical properties of the pressure-sensitive adhesive compositions and pressure-sensitive adhesive sheets prepared in the examples and comparative examples were measured by the following methods, and the results are shown in Table 3 below.

[0161] (1) Calculation of biomass content The biomass content of the adhesive layer of the adhesive sheet was calculated according to the following formula 1, distinguishing between biomass-derived carbon and fossil fuel-derived carbon in accordance with ASTM D6866.

[0162] [Formula 1] Biomass ratio (%) = number of carbon atoms derived from biomass / total number of carbon atoms x 100 (2) Evaluation of adhesive strength The prepared adhesive sheet was cut into a length of 25 mm x width of 100 mm, and the release film was peeled off. The exposed adhesive layer was then attached to a glass substrate (#1737, Corning) at a pressure of 0.25 MPa and autoclaved for 20 minutes at a temperature of 50°C and a pressure of 5 atmospheres to prepare a test specimen. To measure room temperature adhesive strength, the prepared test specimen was left at a temperature of 23°C and a relative humidity of 50% 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 testing machine (UTM, Instron) to measure room temperature adhesive strength.

[0163] To measure the warm adhesive strength, the prepared specimen was left at 50°C and 50% RH for 48 hours. Thereafter, the pressure sensitive 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 testing machine (UTM, manufactured by Instron) at 23°C and 50% RH to measure the warm adhesive strength.

[0164] (3) Evaluation of bending characteristics The prepared adhesive composition was applied onto a release film coated with a silicone release agent, and dried. Then, a dyed and stretched PVA polarizer was laminated on one side of a polarizing plate with TAC (Triacetyl cellulose) films attached to the top and bottom of the polarizing plate with an adhesive. The PVA polarizer was cut into a length of 200 mm and a width of 120 mm, and the release film was peeled off. The exposed adhesive layer was then attached to a glass substrate (210 mm x 130 mm x 0.5 mm) to prepare a test specimen.

[0165] For the heat resistance evaluation and the humidity and heat resistance evaluation, the specimens were left at 80°C and 60°C, 90% RH for 500 hours, respectively, and then removed from the oven, and the lift height of the four corners was measured and the average was calculated. Before measuring the height of the specimen, the specimens were removed from the oven and left for 30 minutes, then placed on a surface plate and measured.

[0166] (4) Reliability evaluation The adhesive sheet was cut into a length of 200mm x width of 300mm, and the release film was peeled off. The exposed adhesive layer was attached to a glass substrate (210mm x 350mm x 0.7mm) and autoclaved (50°C x 30 minutes, 0.5MPa) to prepare a test specimen. The applied pressure was 5kg / cm. 2 The test was carried out in a clean room to prevent the formation of bubbles or foreign matter. For the heat resistance evaluation and the moist heat resistance evaluation, the specimens were left at 80°C and 60°C, 90% RH for 500 hours, respectively, and then removed from the oven to observe the occurrence of bubbles or peeling. The specimens were then removed from the oven and left at room temperature for 24 hours before being observed.

[0167] <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

[0168] [Table 3]

[0169] Referring to Table 3, it can be seen that the pressure-sensitive adhesive sheets prepared using the pressure-sensitive adhesive compositions according to the examples of the present invention have an excellent biomass ratio of 30% or more, maintain adhesive strength, and do not lose heat resistance at high temperatures, thereby maintaining reliability. In addition, it can be seen that the inclusion of the compound represented by Chemical Formula 4 improves bending properties.

[0170] In addition, it can be confirmed that when the compound represented by Chemical Formula 1 of the present invention contains both the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3, the bending properties are more improved than when only one of these compounds is contained.

[0171] On the other hand, Example 3, which contains the compound represented by Chemical Formula 1 of the present invention but has an increased content of crosslinker, showed a slight decrease in adhesive strength, while Examples 4, 14, and 15, which contain the compound represented by Chemical Formula 4 but have the same content of crosslinker as Example 3, showed improved adhesive strength.

[0172] On the other hand, 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 bending properties at high temperature and high humidity are deteriorated.

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 1 to 9 carbon atoms.

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

3. The pressure-sensitive adhesive composition according to claim 1 , wherein the compound represented by Chemical Formula 1 includes a compound represented by Chemical Formula 2 and a compound represented by Chemical Formula 3: [Chemical formula 2] 【Chemistry 4】 [Chemical formula 3] 【Transformation 5】

4. The pressure-sensitive adhesive composition according to claim 3 , wherein the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3 are contained in a ratio of 1:10 to 10:

1.

5. The pressure-sensitive adhesive composition according to claim 1 , wherein the compound represented by Chemical Formula 1 is contained in an amount of 30 to 80 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, further comprising a compound represented by the following chemical formula 4: [Chemical formula 4] 【Transformation 6】 (In the above Chemical Formula 4, Ra to Rc are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroarylene group having 6 to 30 carbon atoms; Any two of Ra to Rc are bonded together to form a ring system.

7. The pressure-sensitive adhesive composition according to claim 6, wherein the compound represented by Chemical Formula 4 includes at least one selected from the group consisting of compounds represented by Chemical Formulas 5 and 6: [Chemical formula 5] 【Transformation 7】 [Chemical formula 6] 【Transformation 8】

8. The pressure-sensitive adhesive composition according to claim 6 , wherein the compound represented by Chemical Formula 4 is contained in an amount of 1.0 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer.

9. The pressure-sensitive adhesive composition according to claim 1, further comprising one or more silane coupling agents selected from the group consisting of compounds represented by the following chemical formulas 7 and 8: [Chemical formula 7] 【Chemistry 9】 (In the above Chemical Formula 7, R ３ is an alkyl group having 1 to 12 carbon atoms, R ４ are each independently a divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, R ５ ~R ７ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. [Chemical formula 8] 【Chemistry 10】 (In the above Chemical Formula 8, R ８ is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, R ９ is a divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, R １０ ~R １２ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

10. The pressure-sensitive adhesive composition according to claim 9, wherein the silane coupling agent is contained in an amount of 0.01 to 3 parts by weight based on 100 parts by weight of the acrylic copolymer.

11. 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 ratio of 30% or more, calculated according to the following formula 1 in accordance with ASTM D6866: [Formula 1] Biomass ratio (%) = number of carbon atoms derived from biomass / total number of carbon atoms × 100

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

13. A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition according to claim 1 .

14. A display comprising the pressure-sensitive adhesive sheet according to claim 13.

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