TW200417589A - Acrylic pressure sensitive adhesive for the polarizing film - Google Patents

Abstract

The present invention relates to an acrylic PSA composition, and more particularly to an acrylic pressure-sensitive adhesive (PSA) composition that comprises the first PSA layer comprising a compound having a positive stress optical coefficient and an acrylic copolymer, and the second PSA layer comprising an acrylic copolymer. An acrylic PSA composition of the present invention can solve the light leakage problem of a liquid crystal display panel by reducing birefringence due to contraction of a polarizer attached to the liquid crystal display panel while maintaining key properties, such as durability and cuttability.

Description

200417589 发明 Description of the invention (The description of the invention shall state: the technical field to which the invention belongs, the prior art, the content, the method of sinus application, and the drawing. [Technical field to which the invention belongs] The present invention and an acrylic pressure-sensitive adhesive (hereinafter referred to as "PSA") components. In particular, the propionic acid PSA component of the present invention can reduce the birefringence of a polarizing film adhered to a liquid crystal display panel due to shrinkage, so it can be used without sacrificing durability and cutability. The light leakage problem of the liquid crystal display panel is solved in the case of important properties such as properties. [Prior technology] A liquid crystal display generally includes a liquid crystal sheet and a plurality of polarizing films, and then the liquid crystal sheet and the liquid crystal display are made of 10 appropriate pressure-sensitive adhesives (PSA). The polarizing film is combined to make a finished product. In addition, the liquid crystal display can also include a phase retardation film or an optical recycling film to enhance the function of the liquid crystal display. The two main components of the liquid crystal display include a liquid crystal properly aligned between two glass plates. Layer 'wherein a color filter and a transparent 15-electron layer are additionally provided' and 2) a polarizing film, if necessary, also includes the use of When the PSA or adhesive agent layer laminated on the glass phase to postpone the diaphragm and other functional film. Polarizing film includes polarizing elements, such as the molecular chain of stretched polyvinyl alcohol (PVA) -based film, or the structure of flue-cured tobacco prepared by the hydrolysis of PVA film or the deacidification reaction of polyvinyl gas (PVC). Ethyl compound or dichloride polarizing material aligned in the orientation, and at least one side of the polarizing element is made of materials such as triethyl cellulose (TAC), polyacid inversion acid, polyoxylylene, polymethylpropane Protective films such as acid esters, and cycloolefin copolymers. In addition, the polarizing film may include a postponed film with anisotropic molecular calibration and / or for the continuation page (if the description page is insufficient, please note and use the continuation page) 200417589 Invention description And brightening functional films, such as an optically designed liquid crystal film. Since the diaphragms described in "J" are made of materials having different molecular structures and components, each has different physical, chemical, and optical properties. When the liquid crystal display 5 is used for a long time, component materials having different molecular structures and components are aged, so that the molecular structures of these materials change accordingly. For example, 1) the difference in linear expansion coefficient between materials due to temperature changes will cause continuous stress to each combined layer, and 2) the material with existing molecular calibration will deform due to stress relaxation, so that the optical properties of the polarizing film will change accordingly 10 causes severe light leakage in the LCD. If non-birefringent materials are used, although this problem can be solved, it may damage other important properties. In particular, in order to adhere to a polarizing film, it is extremely difficult to maintain the original ability of the adhesive when using a PSA that requires systematic control of birefringence. In order to prevent light leakage from polarizing film, the stress caused by the shrinkage of the polarizing film should be eliminated first. However, from the perspective of shrinkage and expansion behavior under high temperature and high humidity conditions, the polarizing film and PSA on glass plates have different shape stability It is difficult to remove the stress buildup between these materials. As far as the stress between the polarizing film and the PSA layer on the glass plate is concerned, US Patent No. 5,795,650, which attempts to relax it, has disclosed that an adhesive composed of a plasticizer 20 component can effectively relax the shrinkage caused by the polarizing film stress. • However, it cannot completely eliminate the light leakage problem, and because the plasticizer component may detract from the PSA's adhesive properties, it may cause durability problems such as air bubbles and edge warping. In addition, if the polarizing film product is cut with a knife, the plasticizer component can be contaminated due to the increase in the softness of the adhesive component. In addition, 'Japanese Patent No. Heisei 10_279907 has disclosed that a mixture of a high molecular weight propylene-based polymer and a propylene-based polymer having a molecular weight of less than 30,000 can reduce stress to prevent light leakage. However, it has not completely eliminated the problem of light leakage, and the reliability of adhesion is doubted because of the possibility of generating a large number of bubbles and lightly curved edges. Moreover, like US Patent No. 5,795,650, the polarizing film may be contaminated by cutting operations. Generally, PSA includes rubber-based, acrylic-based, and silicon-based materials. Among them, propylene-based PSA is widely used because of its high optical performance and bonding quality. Since the propylene-based adhesive can be designed to make the chain flow of the molecule poor if it is slightly pressurized, the propylene-based adhesive exhibits good adhesion characteristics at room temperature. The adhesion of acrylic PSA is approximately 100 to 3000 gm / in. The molecular characteristics of propylene-based PSA materials, such as molecular weight and distribution's parental bifurcation degree and composition, are the main factors affecting the longevity of PSA. They can be controlled by high adhesive strength and cohesive strength. However, the use of PS A, which can relax stress and reduce the buildup of stress in polarizing films, generally shows insufficient durability in terms of resistance to the formation and growth of bubbles and edge warping under high temperature and high humidity conditions. The performance of the board is very important. In addition, when the 20 polarizing film products including highly fluid adhesive plates are subjected to precision cutting, the adhesive easily extends to the outside of the product ', resulting in contamination of the product. In the main needs of polarizing film products, such as the financial longevity and cutability of almost money, to achieve the goal of receiving good PSA leakage. -6- 200417589 Description of the invention, f sell; 1; [Summary of the invention] The object of the present invention is to provide a light leakage problem that can be significantly improved in the case that the main requirements of the polarizing film, such as durability and cuttability, are hardly changed. Of acrylic acid PSA. The way to do this is to reduce the birefringence caused by the shrinkage of the polarizing film adhered to the liquid crystal display panel.另一 Another object of the present invention is to provide a polarizing film using the component. To achieve these objectives, the present invention provides an acrylic-based pSA component, which includes ... 10 a) a first PSA layer containing the following materials, i) a compound with a positive stress optical coefficient, and ii) an acrylic copolymer And b) a second psA layer comprising an acrylic copolymer. [Embodiment] The present invention will be described in detail below. When the liquid crystal display is used for a long time, the optical properties of the composite film will change due to the shrinkage stress of the polarizing unit, resulting in complex optical variability. This is called the sudden birefringence phenomenon or the problem of light leakage. In order to prevent the birefringence of the film, the inventors of the present case have investigated various components of a liquid crystal display 'such as a polarizing unit, a liquid crystal display panel, and a pressure-sensitive adhesive layer. It was found that if materials with different dimensional stability were bonded together, birefringence would occur due to the accumulation of stress in the composite film, resulting in light leakage. In order to solve the problem of light leakage, the present invention provides a psA component, -7-200417589 Description of the Invention # This component includes an optically active component that can automatically compensate for birefringence occurring in the same stress place in the system. With the increase of liquid crystal displays, the optical characteristics of PSA have become more and more important. Therefore, the inventors of the present case tried to form a multilayer PSA film, one of which contained a component capable of compensating for the offset birefringence of the PSA 5 film, and the other contained a component capable of improving durability and reworkability. . Since the PS A layer requires strong cohesion at high temperatures, a suitably crosslinked viscoelastic material can be used to provide the adhesive layer with excellent durability. The molecular structure of cross-linked PSA is usually partially cross-linked, and when some cross-linked molecules are subjected to a stress of 10, the stress of the cross-linked part cannot be fully eliminated, so the molecular chain of the cross-linked part is oriented in a specific direction Withstand stress. The elastic properties of PSA are similar to rubber or elastomer, while the main chain of PSA is aligned in the direction of the applied stress. Therefore, when the material is stressed, it shows positive and negative birefringence, and the polarizing unit under shrinkage stress is characterized by negative stress birefringence in most of the cross-linked linear molecules of 15 PSA components of acrylic acid. . When the PSA of the present invention is not stressed, because the PSA still maintains isotropy, the molecules of the PSA do not change the optical properties of the liquid crystal display. Only when the PSA is stressed due to the shrinkage of the polarizing film, it exhibits birefringence compensation in order to eliminate light leakage from the display. That is, by understanding the stress field of the system 20 and using optical compensation technology, the present invention can be distinguished from other inventions. In addition, the PSA of the present invention and the polarizing film using the PSA can be prepared by a similar procedure to that of the conventional PSA layer.

The propylene-based PSA component of the present invention includes two layers; a) PSA of the first layer -8-200417589 Description of the invention, the continuation layer includes i) a compound having a positive stress optical coefficient and ^) an acrylic copolymer, and b) The second PSA layer includes an acrylic copolymer. In particular, 'based on weight', the PSA of the first layer of the present invention includes 0.001 5 to 40 parts of a compound having a positive stress optical coefficient, 100 parts of an acrylic copolymer, and the copolymer includes 75 to 99.89 Parts of a (fluorenyl) propionate monomer having ^ to Cu group, 0.01 to 1 part of an α, β unsaturated carboxylic acid monomer, and 0.01 to 5 parts of one having a hydroxyl group Group of functional monomers. 10 Based on weight, the pSA of the first layer may additionally include 0.00 to 10 parts of a multifunctional isocyanate cross-linking agent. The a has a positive stress optical coefficient. ) 0 components can be used in combination with acrylic copolymers by copolymerization or blending. There are many materials that can be used as a component, but a component having an asymmetric molecular structure in the axial direction is preferable. In addition, the amount of 15 points in the group is obviously less, so that the performance of the first PSA layer remains unchanged. To this end, a component having an asymmetric structure in the axial direction is used. The PSA resin of the present invention can be prepared by polymerizing a PSA resin with a component having a positive stress optical coefficient in an appropriate ratio to form a structure having a side chain branched from the main chain, or adopting conventional blending techniques. Ingredients, which have properties similar to those of conventional pSA used in adhesive coatings or laminations. In the present invention, the component having a normal stress optical coefficient may include one compound or a mixture of two or more kinds selected from the group consisting of compounds having an asymmetric molecular structure and a normal stress optical coefficient from the axial direction. The present invention -9-200417589 Description of the invention Those compounds having a positive stress optical coefficient can be easily mixed into various components of propylene-based PSA, and the change in the glass transition temperature of this PSA is minimized.

A component having a normal stress optical coefficient may include one compound or a mixture of two or more of five, and the components exhibit a normal stress optical coefficient when they are uniformly dispersed in the PSA. In particular, when the stress is applied to align the main chain of the adhesive in a certain direction, the component is also aligned in the direction of the main chain, so that the birefringence of the PSA layer is changed. When the composite structure of the laminated film shows birefringence due to stress, this component can compensate the birefringence generated by each film. 10 To compensate for the birefringence of the laminated film, such as using a small amount of positive stress optics

In the case of a coefficient component, the birefringence of the component should preferably be large. When the component has a rigid molecular structure and axial asymmetry, the component can be effectively aligned according to the applied stress caused by the PSA birefringence change. That is, when the molecules of the component have a rigid structure and axial asymmetry, the molecules tend to align towards the direction of the PSA 15 main chain, thus generating positive birefringence. Considering the individual optical activities of each layer, the complex birefringence generated by the laminated polarizing unit of the protective film and PSA layer under a specific stress field can be effectively controlled. In addition, when a component having a positive optical coefficient belongs to a low molecular weight, the elasticity and elasticity of PSA increase, so the molecular weight of the component should preferably be 2000 or less. Components with positive stress optical coefficients may include aromatic compounds or alicyclic compounds, where the aromatic compounds are based on whether a substituent of an aromatic ring is present or according to the type of aromatic compound. Its classification is divided into aromatic crystallisation-10- 200417589

DESCRIPTION OF THE INVENTION The fluorene I compound and aromatic liquid crystal compounds such as cholesteric and smectic compounds. A representative example of a normal stress optical coefficient is preferably an aromatic compound represented by the following chemical structural formula 1 or chemical structural formula 2: Chemical structural formula 丨

R2 she

Ja ^ Λf Jb In Chemical Formula 1 and Chemical Formula 2: 10 ×, Y, R1, and R2 are respectively or simultaneously selected from hydrogen, cyanide, chlorine, bromine, hydroxyl, dimethylamine, cumyl ( cumyl), and alkyl, alkoxy, and substituents selected from the group consisting of aryl; A is -CH = N-, -N = N-, _N = N (0)-,- COO-, -CH20, -C (R) -C0-, -COO-CHr, -0C, -C C-, -S-, -S02-, WR1), 15 -CH-N-OCR ^ .N ^ CH-, -C = C-0 (R1) .n = C-, -CC-0 (R1) -C = C.? -C = C.〇 (R1) .〇 (R2) .c = c ^ c = N (I) (r1) N = c ^ -ON-d ^ R ^ d ^ RYc ^ c ·, or a bridge bond connecting the cores of naphthalene or anthracene (where R1 and R2 are ^ To C2O alkyl, alkoxy, and selected substituents in the group consisting of aryl); and 20a and b are integers from 0 to 3 (if a = 0, b is 1 to 3) -11- 200417589 Invention Description $ Sell integer; otherwise b is an integer from 0 to 3). Aromatic compounds represented by Chemical Structural Formula 1 or Chemical Structural Formula 2 include biphenyl, trans-stilbene, azobenzene, p-terphenyl, M-terphenyl 5 (m-terphenyl), cumylphenylbenzoate, diphenylacetylene, 4-ethylbiphenyl, 4'-phenyl-4- 4'-pentyl-4-biphenyl carbonitrile, 4-biphenyl carbonitrile, 4'-pentylbiphenyl, 10 4'-benzene 4'-penthoxy-4-biphenyl carbonitrile, 4'-hexyl-4-biphenylcarbonitrile, 4'-octyl 4'-octyl-4-biphenylcarbonitrile, trans-4-octyl-4'-ethoxystilbene, trans-4-octyl-4'-ethoxystilbene, Naphthalene, 15 anthracene, 4'-methoxybenzylideneaminostilbene, 4'-methoxybenzylideneaminostilbene, 4'-methoxybenzylideneaminostilbene (4 ' -methoxybenzylideneamino azobenzene), its derivatives and mixtures thereof ', but aromatic compounds are not limited to the foregoing. In addition, when aromatic compounds have no X or Y substituents, or when their 20 size is small, aromatic compounds having positive stress optical coefficients include, for example, trans stilbene, terphenyl, diphenylacetylene, or biphenyl. Crystalline material. When the X or Y derivative has a properly combined polarized-non-polarized or chiral group, the material with the X derivative or Y derivative is a smectic or cholesteric liquid crystal compound, an aromatic compound or The -12-200417589 example of cycloaliphatic compounds has been described. (Polymer Liquid Crystals, A. C. Cifferri, W.R. Krigbaum, R.B. Meyer, Academic Press, 1982). Since the molecular structure and miscibility of the components are important for optical properties and PSA 5 performance, the compounds should have normal stress optical coefficients like aromatic and alicyclic compounds. That is, any compound having an anisotropic electronic molecular structure can be used without limitation.

The choice of compounds with positive stress optical coefficients depends on characteristics such as birefringence and adhesive properties. In order to maintain the adhesive properties, the weight of this ingredient is preferably 0.001 to 40 parts, but preferably 0.01 to 30 parts, and most preferably 0.05 to 25 parts. This ingredient can be blended with a PSA in the usual manner. In addition, this component can be incorporated into PSA to form a multilayer PSA structure.

The viscoelastic properties of PSA are mainly determined by the molecular weight of the polymer, its distribution, and its molecular structure. In particular, these properties are better determined by their molecular weight. Therefore, the molecular weight of the propylene-based copolymer of the item a) i) is 200,000 to 2,000,000, but preferably 600,000 to 1,500,000, and based on the weight, for 100 parts of the acrylic copolymer, it includes i ) 75 to 99.89 parts of a (Ci-C12) alkyl ester containing Ci to C12 alkyl esters, preferably (2 to C8 alkyl esters), and ii) a reactive with a cross-linking agent Functional monomer. The content of the (meth) acrylate monomer is preferably 75 to 99.89 parts based on weight, but more preferably 80 to 98 parts. When the alkyl (fluorenyl) acrylate has a long-chain alkyl group, the cohesive force of the adhesive is low. Therefore, a C2 to C8 alkyl group should be used. The invention of 200417589 explains to prevent the cohesive force from decreasing. When the alkyl (fluorenyl) acrylate is excessive, its cohesive force decreases. Based on the weight, when the content of the alkyl (meth) acrylate is less than 75 parts, the adhesive force of the adhesive decreases, and its cost may increase. (Meth) acrylic monomers include butyl (meth) acrylate 5 (butyl (meth) acrylate), 2-ethylhexyl (meth) acrylate, ( Ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acetate ) acrylate), isopropyl (meth) acrylate 10 (isopropyl (meth) acrylate), t-butyl (meth) acrylate, (meth) acrylate Pentyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (meth) acrylate, and Mixtures, but not limited to the aforementioned 15 limit. These monomers may additionally include various propylene-based monomers not mentioned herein and vinyl monomers for specific purposes. The functional monomer in the acrylic copolymer according to item ii) may include 0.1 to 20 parts of an α, β unsaturated carboxylic acid monomer, or 0.01 to 5 for 100 parts of an acrylic copolymer by weight. Parts of a 20 functional monomer with a hydroxyl group, and mixtures thereof. The concentration of the unsaturated α, β carboxylic acid monomer is preferably 0.5 to 15 parts. The functional monomer according to item ii) gives the PSA of the present invention adhesive strength or cohesion. If the content of unsaturated α and β carboxylic acid monomers is less than 0.1 parts, the improvement effect of the adhesive strength is reduced; if it is more than 20 parts, the fluidity is reduced due to the increase of cohesive force, so that the adhesion is reduced -14- 200417589 Description of the invention Unsaturated alpha and beta carboxylic acid monomers include acrylic acid, methacrylic acid, acrylic acid dimmer, itaconic acid, maleic acid, Maleic anhydride, and mixtures thereof, but they are not limited to the foregoing five. The functional monomer having a hydroxyl group and reacting with a cross-linking agent has cohesive force of the PSA because its chemical bond is sufficient to withstand the cohesive destruction of the PSA at high temperatures. Based on the weight, for 100 parts of the acrylic copolymer, the number of such functional monomers having a base group is preferably from 0.001 to 5 parts. If the amount of the functional monomer having a hydroxyl group is less than 0.001 part, cohesive failure occurs at two temperatures of the PSA; if it is more than 5 parts, the softness at high temperature is degraded. These functional monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ( 2-hydroxyethylene glycol (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate, 2-hydroxypropylene glycol (meth) acrylate, and mixtures thereof They are not limited to the foregoing. As long as the acetamyl monomer having a base group is applicable to the present invention, it can also be used in the present invention. Each of the foregoing monomers and mixtures thereof can be used. 20 As long as the objective of the present invention is met, other functional monomers may be used with r or substituted unsaturated α, β carboxylic acid monomers and functional monomers having a hydroxyl group. For example, a multifunctional epoxy compound can react with a functional group of a carboxylic acid, or a multifunctional aziridine can react with a functional group of an acid, or a UV curing agent can be used. Crosslink PSA. In addition, in order to make the PSA of the present invention have an adhesive force, a polarizing material may be used instead of the unsaturated α, β carboxylic acid monomer. The multifunctional compound can be used to generate a crosslinked structure, and the adhesion reliability of PSA is also increased. The propylene-based copolymer according to a) ii) can be prepared by solution polymerization, photopolymerization, polymer polymerization, suspension polymerization, or emulsion polymerization. In particular, the propylene-based copolymer is preferably prepared by solution polymerization at a temperature of 50 to 140 ° C, and an initiator is preferably added when the monomers are uniformly mixed. The multifunctional cross-linking compound used in the present invention can determine the orientation of the polymer main chain and side chains. When it is used for a viscoelastic PSA, it helps to determine the orientation of the polymer main and side bonds. The multifunctional parent cross-linking compound includes an isocyanate cross-linking agent, an epoxy-based cross-linking agent, an aziridine-based cross-linking agent, and a metal chelate. chelate-based) Crosslinking agent. Isocyanate crosslinkers include tolylene 15 diisocyanate '' diphenylmethanediisocyanate, hexamethylenediisocyanate, and its addition to trimethylolpropane Things, but not limited to the foregoing. The aforementioned compounds can effectively provide the cross-linked structure required by the present invention, and 20 can be selected from various combinations of itself and functional groups having a hydroxyl group. During the mixing step, the crosslinking reaction between the compound and the functional group having a hydroxyl group does not occur violently, so it can be uniformly coated. After the PSA layer is coated, dried, and matured, a PSA layer with elasticity and strong cohesive strength can be formed due to the crosslinked structure. PSA's strong cohesion improves -16- 200417589 Description of the invention, continued pages Improve durability and cuttability. Alternatively, PSA can be crosslinked using published ultraviolet or electron beam techniques. To control the properties of PSA, additional tackifiers can be added. Based on the weight, the amount of tackifier is 1 to 100 parts. When too much tackifier is used, the cohesion of PSA 5 may decrease. Tackifiers include (hydrogenated) hydrocarbon-based resin, (hydrogenated) rosin-based resin, (hydrogenated) rosin ester- based resin), (nitrogenated) terpene resin, (hydrogenated) terpene phenolic resin, polymerized rosin resin, and polymerized rosin Esterified rosin ester resin. Tackifiers may also include mixtures of the foregoing. In addition, the PSA component of the present invention may include a mixture of an epoxy resin and a cross-linking agent, a silane coupling agent, a plasticizer, an antioxidant, a UV stabilizer, a reinforcing agent, a filler, 15 and a coloring agent. It depends on the end use of the invention. As for the acrylic acid copolymer of the second layer PS A layer of the item b), the same acrylic acid copolymer as the first PS A layer of the item a) can be used. The second PSA layer should preferably contain an acrylic adhesive with excellent durability and reworkability. 20 The thickness of the first and second PSA layers can be determined by their respective functions. In general, the thickness is preferably 10 to 50 μm. Because the first psa layer is optically active, its thickness can be controlled, depending on the optical properties of the second PSA layer. Based on the characteristics of durability and reworkability, the thickness of the second PSA layer should preferably be 10 to 20 μm. As for the molecular structure of PSA, it is also suitable. -17- 200417589 Description of the invention # 卖 Μ is designed to fully bond the first and second layers of PSA μ + A layer to prevent interfacial stress from causing peeling. The acrylic PSA component 5 X々 of the present invention has a paternal density of 1 to 95%, but preferably 30 to 90%, and more preferably 40 to 80%. PSA knife-making can be prepared by various methods, such as random copolymerization (random CD), graft copolymerization, and block copolymerization. In addition, PSA components can also be prepared by photopolymerization, where appropriate and customary photoinitiators are used. The PSA component of the present invention is not limited to the uses described in 10 ^ ^ ^ U, and the concept of the present invention is also applicable to silicon-based, rubber-based, s ^ ^ carbamoate-based, polyester-based, and soil-based Oxygen PSA and adhesives, 敎 live 彳 ... PsA, and hot-melt adhesives, not the material type. In other words, the aforementioned ingredients are suitable for all kinds of lamination of adhesives that are used as progenitors, so as to provide birefringence compensation for light problems. 15 The acrylic PSA of the present invention can be used to effectively compensate for stress Under complex birefringence, while keeping PSA in its nature, as well as difficult to cut. ~ & High humidity «Impurities & Pairs The present invention also provides a & 20. Then, the polarizing film ::: of the acrylic PSA component includes a psA layer formed on either side of the polarizing film. 1 used components can be expected to make this hair, ㈣ polarizing and polarizing elements. For example, the conventional polarizing film is prepared by adding filled or dichroic wood to materials such as polyvinyl alcohol (polyvinyl alcohol), polyvinyl alcohol (polyvmylformal), and 1 vinyl alcohol. Polyethenol-based membranes such as vinyl acetate, ethylene (hylene), and a vinyl acetate copolymer (vinyi acetate -18-200417589 copolymer) are stretched and the film is stretched. The sheet is laminated with a protective film such as triacetyl cellulose, polycarbonate film, and polyethersulfone film. 5 The way to form a PSA layer on a polarizing film is to apply a PSA solution to the surface of the polarizing film and dry it using a bar-coater; or apply the PSA solution to a peelable material Then, it is dried to form a PSA layer, and then the PSA layer is transferred to the surface of a polarizing film and is matured. 10 The PSA layer of the present invention may be formed on one or both sides of a polarizing film. In addition, the polarizing film of the present invention can be coated with a protective layer, a reflective layer, an anti-glare layer, a retardation plate, a wide-viewing film, or several brightening films. The PSA component of the present invention is not limited to the aforementioned uses, and the 15 concepts of the present invention are also applicable to silicon-based, rubber-based, urethane-based, polyester-based, and epoxy-based PSAs and adhesives to thermally activate PSA , And hot-melt adhesives, regardless of material type. That is, the foregoing components are suitable for all kinds of adhesive laminations used as optical materials to provide birefringence compensation for light leakage problems. 20 The present invention provides a polarizing film including the aforementioned multilayer PSA component. • The polarizing film of the present invention includes a PSA layer formed on either side of the polarizing film. Conventional modules can be used for the polarizing film and polarizing element used in the present invention. For example, the conventional polarizing film is made by adding iodine or dichroic dye to materials such as polyvinyl alcohol, polyvinyl formal, -19-200417589, polyvinyl acetal, ethylene, and A polyvinyl alcohol-based film, such as a vinyl acetate copolymer, which is stretched and combined with a film such as triethyl cellulose, a polycarbonate film, and a polyether film. Laminating film. The way to form a PSA layer on a polarizing film is to apply the PSA solution to the surface of the polarizing film using a rod coater 5 and then dry it; or apply the PSA solution to a peelable material and then dry it In order to form a PSA layer, the PSA layer is then transferred to the surface of a polarizing film and pre-cured. The PSA layer of the present invention may be formed on one or both sides of the polarizing film. In addition, the polarizing film of the present invention can be coated with a protective layer, a reflective layer, a 10-channel anti-glare layer, a retardation plate, a wide-viewing film, or several brightening films. Several examples and comparative examples are given to explain the present invention in detail. However, the following examples are only for understanding the present invention and are not intended to limit the present invention. 15 [Example] Example 1 (Preparation of acrylic copolymer) Based on weight, 94.5 parts of n-butyl acrylate (BA), 5 parts of acrylic acid (AA), and 0.5 parts of 2-hydroxyethyl (fluorenyl) acrylate (2-HEMA) was mixed into a 1000 cc reactor equipped with a temperature controller and a nitrogen reflux condenser. Add 100 parts of ethyl acetate (EAc). The reactor was purged with nitrogen for 20 minutes to remove oxygen from the reactor, and 0.03 parts of 50% azobisisobutyronitrile (AIBN) diluted with ethyl acetate was added and kept at 65 ° The temperature of C is -20-200417589. Description of the invention It is reacted together for 10 hours, according to which acrylic polymer (PA-1) is obtained. Using a polypropylene standard sample, the molecular weight of this acrylic polymer is 600,000 to 1,000,000. (Preparation of acrylic PSA) 5 The preparation of the first PSA layer is based on weight. For 100 parts of the acrylic polymer solution, the acrylic polymer solution (PA-1, 50% solids content) and 7 parts of diphenylacetylene are mixed. Then, add 1.2 parts of toluylene diisocyanate adduct (TDI-1) diluted to 10% with ethyl acetate in a high-speed mixing method, and then dilute to a release film A specific concentration with good coating quality is followed by drying to prepare a first uniform PSA layer with a thickness of 20 μm. The second PSA layer was prepared by weight. For 100 parts of acrylic polymer solution, 15 the acrylic polymer solution (PA-1, 50% solids content) and 1.5 parts of diisocyanate Toluene adduct (TDI-1) was mixed. Dilute it to 10% with ethyl acetate, add it at high speed, then dilute it to a specific concentration with good coating quality on a release film, then dry to prepare a second layer with a thickness of 10 μm Uniform PSA layer. 20 Preparation of Polarizing Film-Laminate the adhesive on an iodine-based polarizing film with a thickness of 185 μm using a laminator to prepare a polarizing film with first and second PSA layers. Example 2 Except that 4 parts of -21-200417589 are used in preparing the first PSA layer based on weight. Inventive Note: Selling diphenylacetylene and 1.8 parts of diisocyanate toluene adduct (TDI-1) The rest are carried out by the same procedure as in Example 1. Example 3

Except that 94.3 parts by weight of n-butyl acrylate (ΒΑ), 5 parts of acrylic acid (AA), and 0.7 parts of 2-hydroxyethyl (meth) acrylate (2-ΗΕΜΑ) were used in the preparation of the acrylic copolymer by weight. ), And 6 parts of diphenylacetylene were used in the preparation of the first PSA layer, and the rest were performed according to the procedure of Example 1. Example 4 10 Except for weight, 86.5 parts of n-butyl acrylate (ΒΑ), 10 parts of methyl acrylate (ΜΑ), 3 parts of acrylic acid (AA), and 0.5 parts of (fluorenyl) acrylic acid were used in the preparation of the acrylic copolymer. Except for 2-hydroxyethyl ester (2-ΗΕΜΑ) and the use of 7 parts of diphenylacetylene in the preparation of the first PSA layer, the rest were performed in the same manner as in Example 1. 15 Example 5

The procedure was the same as in Example 1 except that 6 parts of terphenyl was used instead of 7 parts of diphenylacetylene in preparing the first PSA layer based on weight. Comparative Example 1 20 The procedure was the same as that of Example 1 except that a compound having a normal stress optical coefficient was not used. Comparative Example 2 In addition to using 95 parts of n-butyl acrylate (BA) when preparing an acrylic copolymer based on weight, and not using a compound having a positive optical coefficient of 22-22200417589 when preparing the first PSA layer, and many Except for the functional cross-linking agent, the rest were performed in the same manner as in Example 1. Experiments For polarizing films prepared using the acrylic 5 PSA components prepared in Examples 1 to 5 and Comparative Examples 1 and 2, the durability, light transmission uniformity, cuttability, and reworkability were evaluated in the following manners, respectively. The results are shown in Table 1 below.

a) Ten years of life Using a laminator, a 90 mm X 170 10 mm polarizing film was adhered to both sides of a glass of 110 mm X 190 mm x 0.7 mm with a pressure of about 5 kg / cm2. The optical axes of the polarizing films cross each other to obtain a dark state. This lamination step is performed in a clean room to prevent bubbles or contamination of the panel. Put the test sample in a humidity chamber with a temperature of 60 ° C and a relative humidity (RH) of 90% and leave it for 1,000 hours, in order to use the hot and humid conditions to check whether 15 bubbles are formed and the edges are warped ( edge lifting). In addition, the temperature is 80

The samples were subjected to a heat resistance test in an oven at a temperature of 1,000 ° C in the same manner as the moist heat test for 1,000 hours. In addition, test samples were adjusted for 24 hours at room temperature before performing the evaluation. The durability evaluated was as follows: ：: No bubble or edge warping was observed. 20 △: A small amount of small bubbles and slight edge surface curvature were observed. X: A lot of bubbles and edge warping were observed. b) Light leakage. Observe in a dark room using a backlight system to evaluate the light leakage of the previously prepared samples (cross-polarized state). The measurement of the light transmission uniformity is as follows: -23- 200417589 Description of the invention f Selling stomach 〇: No light leakage was observed with the naked eye. △: Slight uneven light transmission was observed. X: Severe light leakage was observed at the edge of the polarizing film. c) It can be cut 5 The polarizing film including the PSA is cut with a Thomson cutter. The section of the cut polarized film was observed and evaluated as follows: 〇: The degree of adhesion and detachment after cutting was less than 0.2 mm.

△: The degree of adhesion and detachment after cutting was 0.2 to 0.5 mm. X: The degree of adhesion and detachment after cutting is greater than 0.5 mm. 10 d) Reworkability A 90 mm X 170 mm polarizing film coated with a certain amount of PSA is aged at room temperature (23 ° C, 60% relative humidity) for 7 days, and then adhered to a piece of 110 mm X 190 mm X 0.7mm on each side of the glass substrate. After the polarizing film was allowed to stand at room temperature for 1 hour, it was heated at 15 ° C at 50 ° C for 4 hours, and then left at room temperature for 1 hour. In addition, the polarizing film was peeled from the glass substrate. The evaluation of reworkability is as follows:

〇: Easy to peel off. △: A little difficult to peel off. X: Difficult to peel off, for example, glass break or substrate break. -24- 200417589 Description of invention $ Selling stomach Table 1

Category Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Durability 00 × 00 × Transmission uniformity △△ ～ 〇〇〇〇 × 〇 Cutability 〇〇〇〇〇〇〇 Processability: As shown in Table 1, the PSA prepared according to the present invention (Examples 1 to 5) includes a first 5 PSA layer composed of a compound having a positive stress optical coefficient and The second PSA layer composed of an adhesive film with excellent durability and reworkability. If these PSAs are compared with the resins of Comparative Examples 1 and 2, the durability, light transmission uniformity, cuttability, And reworkability is excellent. As mentioned above, the acrylic PSA component of the present invention can reduce the birefringence of the polarizing film adhered to the liquid crystal 10 display panel due to shrinkage, so it can be used without sacrificing properties such as PSA properties, durability and cuttability In the case of important properties, the light leakage problem of the liquid crystal display panel is solved. -25-

Claims (2)

200417589 Patent application scope 1. An acrylic PSA (pressure-sensitive adhesive) component, comprising: a first PSA layer 'comprising a compound having a positive stress optical coefficient and an acrylic copolymer; and a first Two PSA layers containing an acrylic copolymer. 5 2. The acrylic PSA component as described in item 1 of the scope of patent application, wherein the first PSA layer comprises: 0.001 to 40 parts of the compound having a normal stress optical coefficient; and 100 parts based on weight; The acrylic copolymer. 3. According to the acrylic PSA component described in item 2 of the scope of patent application, 10 of which is based on weight. If the first PSA layer is based on 100 parts of the acrylic copolymer, it also contains 0.01 to 10 parts. A versatile cross-linking agent. 4. The acrylic PSA component according to item 1 of the scope of the patent application, wherein the compound having a normal stress optical coefficient is an aromatic or alicyclic compound. 15 5. The acrylic PSA component as described in item 4 of the scope of patent application, wherein the aromatic compound is represented by the following chemical structural formula 1 or chemical structural formula 2: Chemical structural formula 1 Ri R2 Continuation page (please note and use the continuation page when the patent application page is not enough) 200417589 Chemical structural formula 2 5 X, y, 1 ′ and I are, respectively or simultaneously, hydrogen, cyanide, chlorine, molybdenum, diamine, cumyl, and Ci to c20 alkyl, alkoxy, Selected substituents in the group consisting of aryl groups; A is -CH = N-, -N = N (0)-, -COO _, _ CH2〇, -CCR ^ -CO-, -CO〇-CH2- 5 -C = C-? -C C-5 -SO2-, ^ (R1) ^ 10 -CH = N-® (R1) -N = CH-5 -C ^ C-OCR ^ -C ^ C-, -C = C-0 (R1) -0 (R2) -C = C-?- C = N-0 (R1) -0 (R2) -N = C-5, or a bridging bond connecting the cores of naphthalene or anthracene (where R1 and R2 are, respectively or simultaneously, alkyl groups from 〇1 to C2〇 , Alkoxy, and substituents selected from the group consisting of aryl); and 15 & and b is an integer from 0 to 3 (if a = 〇, b is an integer from 1 to 3, otherwise b is 〇 An integer to 3.) 6. The acrylic pSA component according to item 5 in the scope of the patent application, wherein the aromatic compound represented by Chemical Formula 1 or Chemical Formula 2 is selected from biphenyl, trans stilbene, azobenzene, p-terphenyl, M-terphenyl, isopropylbenzyl benzoate, diphenylacetylene, 4-ethyldibenzene, 4, _phenyl_4_diphenylstone nitrile, 4-dibenzylcarbonitrile, 4, benzene Diphenyl, 4, _phenoxydiphenylcarbonitrile, 4'-hexyl-4-diphenylcarbonitrile, 4, -octyl'diphenylcarbonitrile, trans_4_ -27- Application Scope of patents continued octyl-4, ethoxystilbene, naphthalene, anthracene, 4, _methoxybenzylideneaminostilbene, 4, -methoxybenzylideneaminoazobenzene, and The user selected in the group of its mixture. 7. The acrylic PSA component according to item 1 of the scope of patent application, wherein the acrylic copolymer of the first PSA layer contains 75 to 99.89 parts of a Q to C12 alkyl group (based on weight) (Meth) acrylic acid monomer, 0.1 to 20 parts of an α, β unsaturated carboxylic acid monomer, and 0.01 to 5 parts of a functional monomer having a hydroxyl group. 8. The acrylic PSA component as described in item 3 of the scope of the patent application, wherein the multifunctional crosslinking agent is selected from the group consisting of an isocyanate crosslinking agent, an epoxy parent crosslinking agent, an aziridinyl crosslinking agent, and a metal One or more compounds selected from the group consisting of chelating crosslinking agents; wherein the isocyanate crosslinking agent is selected from diphenyl isocyanate, diphenylmethane diisocyanate, hexamethylene monoisocyanate, and The selected group consisting of trimethylolpropane. 9. The component PGJA as described in item 1 of Shenyan's patent scope, "based on weight 1, the first PSA layer further contains 1 to 100 parts of (hydrogenated) hydrocarbon resin, ( (Hydrogenated) rosin resin, (hydrogenated) rosin ester resin, (hydrogenated) tenenyl resin, (hydrogenated) tenenol resin, polymerized rosin resin, and polymerized rosin ester resin selected from the group consisting of more than one or more thickening agents The acrylic acid PSA component as described in item 1 of Shenyan's patent scope, ^ contains a group consisting of epoxy resin, hardener, ultraviolet stabilizer, antioxidant, coloring and strengthening agent, and filler. One or more additives used in the selection. -28- 200417589 Application special surface _ 1 The acrylic acid PSA component described in item 1 of the scope of patent application, wherein the weight of the second PSA layer includes : 100 parts acrylic copolymer, this copolymer contains 75 to 99 89 parts of (meth) acrylic acid monomer with cj Cl channel group, 0 to 20 parts 5-species of α, β residues and carboxylic acid monomers, and _ to 5 parts-species have the function of μ group And monomers; and ω parts—a kind of multifunctional ^ acid-vinegar cross-linking agent. 12 · Acrylic PSA component as described in the first patent claim, " The thickness of the first αA PSA layer The thickness of the second PSA layer is 10 to 50 mm, and the thickness of the second PSA layer is 10 to 20 μm. 13. The acrylic psA component according to item 丨 of the patent application scope, wherein the acrylic adhesive component is a crosslinking agent Density is i to 95%. 14. A polarizing film containing a pSA film as described in item 1 of the patent application range. -29-