TWI257944B - 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

1257944 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明"PSA") related ingredients. In particular, the acrylic PSA component of the present invention can reduce the birefringence caused by shrinkage of the polarizing film adhered to the liquid crystal display panel, so that it can be solved without sacrificing important properties such as durability and cuttability. The liquid crystal display does not have a light leakage problem. [Prior Art] A liquid crystal display generally includes a liquid crystal film and a plurality of polarizing films, and a liquid crystal film and a polarizing film are combined by using a suitable pressure-sensitive adhesive (P s A) to form a finished product. In addition, the liquid crystal display may also include a phase retardation film or an optical circulation film to enhance the function of the liquid crystal display. The two main components of the liquid crystal display are: 1) a liquid crystal layer properly aligned between two glass plates, wherein a color filter and a transparent 15 electron layer are additionally provided inside, and 2) a polarizing film, if necessary Also included are phase retardation diaphragms and other functional membranes laminated to a glass sheet using a suitable binder or PSA layer. The polarizing film comprises a polarizing element, such as a molecular chain of a stretched polyvinyl alcohol (PVA) based membrane, or an olefin structure prepared by hydrolysis of a PVA membrane or dehydrochlorination of polyvinyl chloride (PVC). Oriented aligned iodine-based compound or dichloro-polarizing material, and at least one side of the polarizing element is composed of, for example, triethyl fluorenyl cellulose (TAC), polycarbonate, polyoxyn benzene, polymethyl methacrylate, and A protective film such as a cycloolefin copolymer or the like is protected. In addition, the polarizing film may include a retardation film with anisotropic molecular calibration and/or for a continuation page (please note and use the continuation page when the invention page is not available) ^257944 Wide viewing angle compensation and brightening A functional membrane, such as an optically designed liquid crystal membrane. ^The aforementioned film has different physical, chemical and optical properties because it is made of a material having a different molecular structure and composition. When the liquid crystal display is used for a long period of time, the constituent materials different in molecular structure and composition from each other are aged, so that the molecular structure of the materials changes. For example, 1) the difference in linear expansion coefficient between materials due to temperature changes, ^ causes continuous stress in each combined layer, and 2) the material with the existing molecular calibration is deformed by stress relaxation, so that the optical properties of the polarizing film change accordingly. , 1〇 causes serious leakage of the liquid crystal display. If non-birefringent materials are used, this problem can be solved, but it may damage other important properties. In particular, in order to adhere to the 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 of the polarizing film, the 15 force caused by the shrinkage of the polarizing film should be eliminated first, but the shrinkage film and PSA on the glass plate have different shape stability characteristics from the shrinkage and expansion behavior under high temperature and high humidity conditions. Therefore, it is difficult to remove the stress accumulation between the materials. In the case of the stress between the polarizing film and the PSA layer on the glass plate, U.S. Patent No. 5,795,650, which is incorporated herein by reference, discloses that the adhesive consisting of the plasticizer 20 component can effectively relax due to shrinkage of the rice film. Stress. However, it does not completely eliminate the light leakage problem, and the plasticizer component may detract from the adhesion properties of the PSA, which may cause durability problems such as bubbles and edge warpage. Further, when the polarizing film product is cut with a knife, since the softness of the binder component is increased, the plasticizer component can be contaminated with a polarizing film. In addition, the Japanese Patent Application Laid-Open No. Hei. No. Hei. No. Hei. However, it has not completely eliminated the light leakage problem, and the reliability of the adhesion is suspected because of the possibility of generating a large number of bubbles and edge distortion. Furthermore, as in U.S. Patent No. 5,795,650, the polarizing film may also be contaminated by the cutting operation. 10 15 In general, PSAs include rubber-based, acryl-based, and fluorene-based materials, of which propylene-based PSAs are widely used due to their high optical properties and bonding qualities. Since the propylene-based adhesive can be designed to be slightly pressurized to deteriorate the molecular chain mobility, the propylene-based adhesive exhibits good adhesion characteristics under slight pressure at room temperature. The adhesion of acrylic PSA is approximately 1 到 to 3000 gm/m. The molecular properties of propylene-based PSA materials, such as molecular weight and distribution, crosslink density and composition, are the main factors affecting the pSA enthalpy. They can be controlled by high adhesion strength and cohesive strength. However, in the case of 20, the stress relaxation is relaxed to reduce the stress accumulation of the polarizing film, but the durability W?% in the formation and growth resistance of the bubble and the edge warp under high temperature and high humidity conditions is exhibited; eight & The court is very important for the I. In addition, the ^ ^^ ^ guar agent, which has a flexible sheet of the method of ^ ^ ^ ^, is easily extended to the outside of the product, resulting in contamination of the product.

PSA seeks, for example, the durability and the light leakage of good PSA. Therefore, it must be changed under the condition that the main cutting property of the polarizing film product is hardly changed. 0 -6-1257944 Description of the Invention, Continued [Invention Content It is an object of the present invention to provide a propylene glycol PSA component which can significantly improve the light leakage problem of pSA in the case where the main requirements of the polarizing film, such as durability and cuttability, are hardly changed. The way to achieve this is to reduce the birefringence caused by shrinkage of the polarizing film adhered to the liquid crystal display panel. Another object of the present invention is to provide a polarizing film using the composition. To achieve these objects, the present invention provides an acrylic based pSA composition comprising: 10 a) a first layer of PSA comprising the following materials, i) a compound having a positive stress optical coefficient, and ii) an acrylic copolymer And b) a second layer of pSA comprising an acrylic copolymer. [Embodiment] The present invention will now be described in detail. When the liquid crystal display is used for a long time, the optical properties of the composite film are changed due to the contraction stress of the polarizing unit, so that a complicated optical sag occurs, which is called a sudden birefringence phenomenon or a light leakage problem. In order to prevent the film from emitting a birefringence problem, the inventors of the present invention have investigated various kinds of liquid crystal displays, such as a polarizing unit, a liquid crystal display panel, and a pressure sensitive adhesive (pSA) layer. As a result, it has been found that if the materials of the respective dimensional stability are bonded together, birefringence occurs due to stress accumulation in the composite film, resulting in light leakage. In order to solve the problem of light leakage, the present invention provides a PSA component, 1257944 - Description of the Invention® This component comprises an optically active component that automatically compensates for the birefringence occurring at the same stress site in the system. As liquid crystal displays increase, the optical properties of PSAs become more and more important. Accordingly, the inventors of the present invention have attempted to form a multilayer PSA film in which one layer contains a component which compensates for the offset birefringence of the PSA 5 film, and the other layer contains a component which enhances durability and reworkability. . Since the PSA layer requires strong cohesion at high temperatures, a suitably crosslinked viscoelastic material can be used to provide excellent adhesion to the adhesive layer. The molecular structure of cross-linked PSA is usually partially cross-linked. When the partially cross-linked molecule is subjected to 10 stress, the cross-linking part of the molecular chain is in a specific direction because the stress of the cross-linked part cannot be completely eliminated. 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, while the polarizing element under contraction stress is characterized by negative stress birefringence in the crosslinked linear molecules of most acrylic 15 PSA components. . When the PSA of the present invention is not stressed, since the PSA remains 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 shrinkage of the polarizing film does it exhibit birefringence compensation to eliminate light leakage from the display. That is to say, by utilizing the optical compensation technique by understanding the stress field of the system 20, the difference between the present invention and other inventions can be distinguished. Further, the PSA of the present invention and the polarizing film using the same can be prepared by a similar procedure as the conventional PSA layer.

The propylene-based PSA component of the present invention comprises two layers; a) the first layer of PSA -8-1257944 _

BRIEF DESCRIPTION OF THE INVENTION The $E layer comprises i) a compound having a positive stress optical coefficient and ii) an acrylic copolymer, and b) the second layer of the PSA layer comprises an acrylic copolymer.

In particular, the PSA of the first layer of the present invention comprises, by weight, from 0.001 to 40 parts of a compound having a positive stress optical coefficient, 100 parts of an acrylic copolymer, and the copolymer comprises from 75 to 99.89 parts. a (meth) acrylate monomer of Q to a C12 alkyl group, 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. 10 The first layer of PSA may further comprise from 0.01 to 10 parts of a multifunctional isocyanate crosslinking agent, based on the weight.

The a) i) component having a positive stress optical coefficient can be used in combination with an acrylic copolymer by copolymerization or blending. There are many kinds of materials which can be used as components, but it is preferred to have a component having an asymmetric molecular structure in the axial direction. In addition, the amount of the 15 points is obviously less, so that the performance of the first layer of the PSA layer remains unchanged. For this purpose, the user is a component having an asymmetric structure in the axial direction. The PSA resin can be prepared by polymerizing a PSA resin with a component having a positive stress optical coefficient in an appropriate ratio for forming a structure having a side chain branched from a main chain, or adopting a conventional blending technique. Ingredients, the ingredients prepared in 20 have similar properties to conventional PSAs used in adhesive coatings or lamination. In the present invention, the component having a positive stress optical coefficient may include a compound selected from the group consisting of a compound having an asymmetric molecular structure and a positive stress optical coefficient or a mixture of two or more. The present invention is in the form of a compound having a positive stress optical coefficient, which is easy to mix into a propylene-based PSA of various components and reduces the change in the glass transition temperature of the PSA to lowest.

The component having a positive stress optical coefficient may include one compound or a mixture of two or more, and exhibits a positive stress optical coefficient when the components are uniformly dispersed in the PSA. In particular, when the applied stress causes the main chain of the adhesive to be aligned in a certain direction, the composition 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 exhibits birefringence due to stress, the composition compensates for the birefringence produced by each of the films. 10 to compensate for the birefringence of the laminated film, such as using a small amount of positive stress optics

When the composition of the coefficient is used, the birefringence of the component is preferably large. When the component has a rigid molecular structure and axial asymmetry, the component is effectively aligned in accordance with the applied stress generated 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 toward the main chain of the PSA 15 and thus produce positive birefringence. Considering the individual optical activity of the layers, the complex birefringence produced by the laminated polarizing elements of the protective film and the PSA layer under specific stress fields can be effectively controlled. Further, when the component having a positive optical coefficient belongs to a low molecular weight, the elasticity and elasticity of the PSA are increased, and thus the molecular weight of the component is preferably 2,000 or 20. • The component having a positive stress optical coefficient may include an aromatic compound or an alicyclic compound, wherein the aromatic compound is based on whether or not a substituent of the aromatic ring is present or according to the kind of the aromatic compound. Dividing its classification into aromatic crystals-10-1257944 Description of the invention, an organic liquid crystal compound such as a cholesteric and smectic compound. A representative example having a positive stress optical coefficient is preferably an aromatic compound represented by the following chemical structural formula 1 or chemical structural formula 2: Chemical structural formula 1

10 X ' Y ' Rl, and R 2 are respectively alkyl, alkoxy, and aromatic from hydrogen, cyanide, gas, bromine, hydroxyl, dimethylamine, cumyl, and q to Cm. Substituents selected from the group consisting of bases; in Chemical Formula 1 and Chemical Formula 2:

A is -CH=N-, -Ν=Ν·,·Ν=Ν(0)-, _C00, _CH20_, -c^rYco-, -COO-CH2-,-〇C-,-C C-,- S-,-S02-,AR1)-, 15 -ch^n-ocr^-n^ch-, C = C.〇(R1)-〇(r2).c = C-5-C=N-0 (R1)-®(R2).N = C-5 -ON-dKRb-c^Rb-C^C-, or a bridging bond connecting the cores of naphthalene or onion (where R1 and R2 are respectively or simultaneously a substituent selected from the group consisting of Ci to C2 alkyl, alkoxy, and aryl; and 20 a and b are integers from 0 to 3 (if a = 〇, b is 1 to 3 - 11- 1257944 _ Description of the invention, continuation page integer; otherwise b is an integer from 0 to 3. The aromatic compound represented by Chemical Formula 1 or Chemical Formula 2 includes biphenyl, trans-stilbene, azobenzene, p-terphenyl. , m-terphenyl, cumylphenylbenzoate, diphenylacetylene, 4-ethylbiphenyl, 4'-phenyl- 4-, 4-pentyl-4-biphenyl carbonitrile, 4-biphenylcarbonitrile, 4'-pentylbiphenyl, 10 4'-benzene 4'-penthoxy_4-biphenylcarbonitrile, 4'-hexyl-4-biphenylcarbonitrile, 4'-octyl-4 -4'-octyl-4-biphenylcarbonitrile, trans-4-octyl-4'-ethoxystilbene, naphthalene (trans-4-octyl-4'-ethoxystilbene) Naphthalene), 15th anthracene, 4'-methoxybenzylideneaminostilbene, 4'-methoxybenzylideneamino phenylene (4'-methoxybenzylideneamino) Azobenzene)' is a derivative and a mixture thereof, but the aromatic compound is not limited to the foregoing. Further, when the aromatic compound has no substituent of X or Y, or their 20 size is small, the aromatic compound having a positive stress optical coefficient includes, for example, trans stilbene, terphenyl, diphenylacetylene, or biphenyl. Crystal material. When the X or Y derivative has a properly combined polarized-non-polarized or chiral group, the material having the X derivative or the Y derivative is a smectic or cholesteric liquid crystal compound, an aromatic compound or Cycloaliphatic compounds -12- 1257944 !- Description of the invention _ Stomach examples have 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 component are important for optical properties and PSA 5 performance, the compound should have a positive stress optical coefficient such as an aromatic compound and an alicyclic compound. That is, any compound having an anisotropic electron molecular structure can be employed without limitation.

There are many choices for compounds with positive stress optical coefficients, depending on characteristics such as birefringence and adhesion properties. In order to maintain the adhesive property, the amount of the component is preferably from 0.001 to 40 parts, preferably from 0.01 to 30 parts, preferably from 0.05 to 25 parts, based on 10 parts by weight. This ingredient can be blended with a PSA in a conventional manner. In addition, this component can be incorporated into the PSA to form a multilayer PSA structure.

The viscoelastic properties of PSA depend mainly on the molecular weight of the polymer, which is determined by its molecular structure. In particular, these properties are preferably determined by their molecular weight. Therefore, the propylene-based copolymer of the item a) i) has a molecular weight of 200,000 to 2,000,000, but preferably 600,000 to 1,500,000, and further preferably the weight, based on 100 parts of the acrylic copolymer, includes i 75 to 99.89 parts of a (fluorenyl) acrylate monomer comprising C! to c12 alkyl ester but having a c2 to c8 alkyl ester of preferably 20, and ii) reacting with a crosslinking agent Functional monomer. The (meth) acrylate monomer is preferably contained in an amount of from 75 to 99.89 parts by weight, preferably from 80 to 98 parts by weight. When the alkyl (meth) acrylate has a long chain group, the cohesive force of the binder is low, so it is preferred to use a C2 to C8 alkyl group, -13-1257944 !- In order to prevent cohesion from decreasing. When the alkyl (mercapto) acrylate is excessive, its cohesive force is reduced. On the basis of weight, when the content of the alkyl (mercapto) acrylate is less than 75 parts, the adhesive force of the adhesive is lowered, and the cost thereof may be increased. The (meth)acrylic monomer includes butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( Ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acrylate ), (isopropyl) isopropyl (meth) acrylate, (methyl) methacrylate (t-butyl (meth) acrylate), (methyl) pentyl acrylate ( Pentyl(meth)acrylate), n-octyl(meth)acrylate, (ison) (isononyl(meth)acrylate) and mixtures thereof, but Not limited to the foregoing. These monomers may additionally include various propylene-based monomers not mentioned herein and vinyl monomers used for specific purposes. The functional monomer in the acrylic copolymer of the item ii) may comprise from 0.1 to 20 parts of the α,β unsaturated carboxylic acid monomer, or from 0.01 to 5, based on the weight of the acrylic copolymer. A 20 functional monomer having a hydroxyl group, and mixtures thereof. The concentration of the unsaturated α, β carboxylic acid monomer is preferably from 0.5 to 15 parts. The functional monomer of item ii) imparts adhesive strength or cohesion to the PSA of the present invention. If the content of unsaturated α and β carboxylic acid monomers is less than 0.1 part, the effect of improving the adhesion 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 weakened by the strong -14 - 1257944 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. A functional monomer having a hydroxyl group and reacting with a crosslinking agent imparts cohesive force to the PSA because its chemical bond is sufficient to withstand the cohesive failure of the PSA at high temperatures. The amount of such a functional monomer having a hydroxyl group is preferably from 0.01 to 5 parts by weight based on 100 parts of the acrylic copolymer. For example, when the amount of the functional monomer having a hydroxyl group is less than 1 part of 〇·〇, the PSA undergoes cohesive failure at a high temperature; and if it is more than 5 parts, the softness at a high temperature is degraded. The functional monomers include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, ( 2-hydroxyethyleneglycol (meth)acrylate, (meth)acrylic acid-2, hydroxypropyleneglycol (meth)acrylate, and mixtures thereof, but They are not limited to the foregoing. The ethylenic monomer having a hydroxyl group can also be used in the present invention as long as it is suitable for use in the present invention. Each of the foregoing monomers and mixtures thereof can be used. 20 Other functional monomers may also be used, or substituted for unsaturated alpha, beta carboxylic acid monomers, and functional monomers having hydroxyl groups, as long as they meet the objectives of the present invention. For example, multifunctional epoxides are The functional group of the monocarboxylic acid reacts, or the multifunctional aziridine reacts with the carboxylic acid, or an ultraviolet curing agent is used to crosslink the PSA. This -15- 1257944 ~~ —~~— Describing the Invention </ RTI> In order to make the PSA of the present invention have adhesive force, a polarizing material may be substituted for the unsaturated α, β carboxylic acid monomer. The multifunctional compound may be used to produce a crosslinked structure. The adhesion reliability is also increased. The propylene-based copolymer of the item a) ii) can be prepared by solution polymerization, photopolymerization, 5-mer polymerization, suspension polymerization, or emulsion polymerization, etc. In particular, the propylene-based copolymer is preferably 50. It is prepared by solution polymerization at a temperature of 140 ° C, and an initiator is preferably added when the monomers are uniformly mixed.

The multifunctional cross-linking compound used in the present invention is capable of determining the orientation of the polymer backbone and side chains, and when used in a viscoelastic PSA, contributes to the orientation of the polymer backbone and side chains.

The multifunctional crosslinking compound includes an isocyanate crosslinking agent, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, and a metal chelate (metai). Chelate-based) Crosslinker. The isocyanate crosslinking agent includes t〇lylene 15 diisocyanate 'diphenylmethanediisocyanate, hexamethylenediisocyanate and its trimethyl propylene hydride ( An adduct of trimethylolpropane), but not limited to the foregoing. The foregoing compounds are effective for providing the crosslinked structure required for the present invention, and the 20 thereof can be selected from various combinations of itself and a functional group having a hydroxyl group. • During the mixing step, the crosslinking reaction of the compound with the functional group having a hydroxyl group does not occur fiercely, so it can be uniformly coated. After completion of the coating of the pSA layer, drying, and the ripening step, a PSA layer having elasticity and strong cohesive strength can be formed due to the crosslinked structure. The powerful cohesion of PSA -16-1257944 !__ Description of invention _ stomach durability and cuttability. In addition, PSA can be crosslinked using open UV or electron beam technology. To control the properties of the PSA, an additional tackifier can be added. The tackifier is used in an amount of from 1 to 100 parts by weight. When the amount of tackifier is too much, the cohesion of PSA 5 may be reduced. The tackifier includes (hydrogenated hydrocarbon-based resin), (hydrogenated) rosin-based resin, (hydrogenated rosin ester-based resin) , (hydrogenated terpene resin), (hydrogenated terpene phenolic resin), polymerized rosin resin, and polymerized rosin (polymerized rosin) Ester resin). The tackifier may also include the aforementioned mixtures. In addition, the PSA component of the present invention may comprise a mixture of an epoxy resin and a crosslinking agent, a decyl coupling agent, a plasticizer, an antioxidant, a UV stabilizer, a reinforcing agent 'filler' 15 and a coloring agent. Depending on the end use of the invention. For the acrylic copolymer of the second PSA layer of the item b), the same acrylic copolymer as the first layer of the PSA layer of the item a) can be used. The second layer of the PSA layer preferably contains an acrylic adhesive having excellent durability and reworkability. The thickness of the first and second layers of the PSA layer can be determined by their respective functions. In general, the thickness is preferably 10 to 50 μηι. Since the first layer of PSA layer is optically active, its thickness can be controlled, depending on the optical properties of the second layer of PSA layer. The thickness of the second layer of the PSA layer is preferably 10 to 20 μm based on the characteristics of durability and reworkability. As for the molecular structure of PSA, it is also desirable to design the H-layer PSA layer to be sufficiently bonded to prevent the interface stress from being peeled off. The cross-linking density of the PSA component of the present invention is from i to 95%, but from 30 to 90. /. It is better if it is 4〇 to 8〇%. The PSA component can be prepared by various methods such as random copoiymedzation 'graft copolymerization, and block copolymerization. Alternatively, the PSA component can be prepared by photopolymerization using suitable and conventional photoinitiators. The PSA component of the present invention is not limited to the aforementioned route, and the concept of the present invention is also applicable to the 11-base, rubber-based, carbamate-based group, "base, epoxy group PSA and binder, heat activated, And the secret adhesive, the material type is not clear. That is to say, the aforementioned ingredients are applicable to all kinds of adhesive laminations as photonic materials to provide birefringence compensation for light leakage problems. The acrylic PSA component of the present invention is effective in compensating for complex birefringence under stress while maintaining the properties and durability of PSA at high temperatures and high humidity, as well as cuttability. The present invention also provides a polarized light comprising the aforementioned acrylic acid psA component. The trim of the present invention includes a PSA layer formed on either side of the polarizing film. The white component can be used for the polarizing film and the polarizing element used in the present invention. For example, the conventional polarizer includes a film prepared by adding an angstrom or a dichroic dye to, for example, polyvinyl alcohol (P〇lyvinylalcohol), polyvinylf〇rmai (polyvinylf〇rmai), polyvinyl alcohol. a polyvinyl alcohol-based membrane such as acetic acid (p〇iyVinyiacetai), ethylene, and a copolymer of acetic acid (Vinyi acetate 1257944 _ invention _ stomach copolymer), which is then stretched and This film is laminated with a film such as a triacetyl cellulose, a polycarbonate film, and a polyethersulfone film. 5 The PSA layer is formed on the polarizing film by applying a PSA solution onto the surface of the polarizing film using a bar-coater and drying it; or applying the PSA solution to the peelable material. Then, it is dried to form a PSA layer, and then the psa layer is transferred onto the surface of the polarizing film and preliminarily formed. 10 The PSA layer of the present invention may be formed on one or both sides of the polarizing film. Further, the polarizing film of the present invention may be coated with a protective layer, a reflective layer, an anti-glare layer, a retardation plate, a wide viewing angle film, or Several layers of brightening film. The PSA component of the present invention is not limited to the aforementioned use, and the 15 of the present invention is also applicable to sulfhydryl, rubber-based, amino phthalate-based, polyester-based, decyloxy PSA and binder, heat activated. PSA, as well as hot melt adhesives, do not conform to the material type. That is, the foregoing ingredients are suitable for all kinds of adhesive laminations as light-preventing materials to provide birefringence compensation for light leakage problems. 20 The present invention provides a polarizing film comprising the aforementioned multilayer PSA component. The polarizing film of the present invention comprises a polarizing film formed on the film

The PSA layer on either side. A conventional component can be used for the polarizing film and the polarizing element j used in the present invention. For example, the conventional polarizing film includes a film prepared by adding iodine or a chromatic dye to, for example, polyvinyl alcohol or polyvinyl ketamine. Aldehyde, -19- 1257944 Description of the Invention A polyvinyl alcohol-based film such as polyvinyl acetal, ethylene, and a vinyl acetate vinegar copolymer, which is stretched and allowed to be bonded to a film such as Laminates such as ethyl cellulose, polycarbonate coatings, and filming films are laminated. In the polarizing (four) upper PSA layer, the material of the PSA layer is applied to the surface of the polarizing film by the rotary coater 5, and then dried; or the PSA cold liquid is applied to the peelable material, and then dried. In order to form a PSA layer, the PSA layer is then transferred to the surface of the polarizing film and preliminarily formed. 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 may be coated with a protective layer, a reflective layer, 10 anti-glare layers, a retardation plate, a wide viewing angle film, or a plurality of 0-layer brightness enhancing films. θ cite several examples and comparative examples, and the present invention will be described in detail later. However, the following examples are merely for understanding the invention and are not intended to limit the invention. 15 [Examples] Example 1 (Preparation of a propionate copolymer) 94.5 parts of n-butyl acrylate (ΒΑ), 5 parts of acrylic acid (ΑΑ), and 〇·5 parts (mercapto) acrylic acid-2, based on the weight. A mixture of -hydroxyethyl vinegar (2-oxime) was placed in a 1000 cc reactor equipped with a temperature controller and a nitrogen reflux condenser. 100 parts of ethyl acetate (EAc) was added. 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 allowed to pass at 65 °. Temperature of C-20-1257944 Description of the Invention The stomach was reacted together for 10 hours to obtain an acrylic polymer (PA-1). The acrylic polymer has a molecular weight of 600,000 to 1,000,000 using a standard sample of polypropylene. (Preparation of acrylic PSA) 5 Preparation of the first layer of PSA layer Based on the weight, the acrylic polymer-based solution (PA-1, 50% solid content) is made with respect to 100 parts of the acrylic-based polymer solution. 7 parts of diphenylacetylene were mixed. Then, 1.2 parts of toluylene diisocyanate adduct (TDI-1) diluted with ethyl acetate to 10% was added thereto in a high-speed mixing manner, and then diluted to a release film. A specific concentration of good coating quality was followed by drying to prepare a first layer of uniform PSA layer having a thickness of 20 μm. The second layer of PSA layer is prepared on a weight basis, and for 100 parts of the acrylic-based polymer solution, 15 is made of the acrylic-based polymer solution (ΡΑ-1, 50% solid content) and 1.5 parts of diisocyanate. The terpene benzene adduct (TDI-1) is mixed. It was diluted to 10% with ethyl acetate, added in a high-speed mixing manner, and then diluted to a specific concentration which can have a good coating quality on a release film, followed by drying to prepare a second layer having a thickness of 10 μm. A uniform PSA layer. 20 Preparation of polarizing film A binder was laminated on an iodine-based polarizing film having a thickness of 185 μm by a laminator to prepare a polarizing film having first and second PSA layers. Example 2 Except that 4 parts of -21-5797944 were used in the preparation of the first layer of PSA layer, except for the weight, and the toluene adduct (TDI-1) of 1.8 parts of diisocyanate was used. The rest were carried out in the same manner as in Example 1. Example 3

In addition to the weight, 94.3 5 parts of n-butyl acrylate (BA), 5 parts of acrylic acid (AA), and 0.7 parts of 2-hydroxyethyl (meth) acrylate (2-HEMA) were used in the preparation of the acrylic copolymer. ), and using 6 parts of diphenylacetylene in the preparation of the first layer of PSA layer, the rest were carried out in the same manner as in Example 1. Example 4 10 86.5 parts of n-butyl acrylate (BA), 10 parts of methyl acrylate (MA), 3 parts of acrylic acid (AA), and 0.5 parts of (indenyl) acrylic acid were used in the preparation of the acrylic copolymer, except by weight. 2-Hydroxyethyl ester (2-HEMA), and 7 parts of diphenylacetylene were used in the preparation of the first PSA layer, and the rest were carried out in the same manner as in Example 1. 15 Example 5

The procedure as in Example 1 was carried out except that 6 parts of terphenyl was used instead of 7 parts of diphenylacetylene in the preparation of the first PSA layer, based on the weight. Comparative Example 1 20 Except that a compound having a positive stress optical coefficient was not employed, the procedure was carried out as in Example 1. Comparative Example 2 95 parts of n-butyl acrylate (BA) were used in the preparation of the acrylic copolymer, and no -22-1257944 was used in the preparation of the first PSA layer, except for the weight. Except for the compound of the coefficient and the multifunctional crosslinking agent, the rest were carried out in the same manner as in Example 1. Experimental For the polarizing films prepared using the acrylic acid 5 PSA compositions prepared in Examples 1 to 5 and Comparative Examples 1 and 2, durability, transparency, cuttability, and reworkability were evaluated in the following manners, respectively. The result shown in Table 1 below is the result.

a) durability

A 90 mm X 170 10 mm polarizing film was adhered to both sides of a 110 mm X 190 mm x 0.7 mm glass using a laminator at a pressure of approximately 5 kg/cm2. The optical axes of the respective polarizing films cross each other to obtain a dark state. This lamination step is carried out in a clean room to prevent bubbles or contamination of the panel. Place the test sample in a humid chamber at a temperature of 60 ° C and a relative humidity (RH) of 90% for 1 hour, in order to check whether the shape is 15 bubbles or not. Lifting). In addition, the samples were subjected to a heat resistance test for 1,000 hours in the same manner as the damp heat test in an oven at a temperature of 80 °C. In addition, the test samples were conditioned for 24 hours at room temperature prior to performing the evaluation. The durability of the evaluation was as follows. 〇: No bubble or edge buckling was observed. 20 △: A small amount of small bubbles and slight edge warpage were observed. • X: A large number of bubbles and edges are observed. b) Light leakage Light is observed in a dark room using a backlight system to evaluate the light leakage of the sample (cross-polarized state) prepared as before. The measurement of the uniformity of light transmission is as follows: -23- 1257944 - Description of the invention Page H 〇: No light leakage was observed by the naked eye. △: A slight uneven light transmission was observed. X: A serious light leakage was observed at the edge of the polarizing film. c) Cuttable 5 A Thomson cutter is used to cut the polarizing film including the PSA. The cross section of the cut polarizing 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 peeling after cutting is 0.2 to 0.5 mm. X: The degree of adhesion 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 Each side of the glass substrate of mm X 0.7 mm. After the polarizing film was allowed to stand at room temperature for 1 hour, it was heated at a temperature of 15 ° C for 5 hours, and then allowed to stand at room temperature for 1 hour. Further, the polarizing film was peeled off from the glass substrate. The evaluation of reworkability is as follows:

〇: Easy to peel off. △: It is a little difficult to peel off. X: Difficult to peel off, for example, glass breakage or substrate cracking. -24- 1257944 - Invention description $卖Μ Table 1

Category Example 1 Example 2 Example 3 Example 4 Example 5 Comparison Example 1 Comparison Example 2 Durability〇〇〇〇〇〇X Transmittance uniformity 〇△~〇〇〇〇X 〇Cutability 〇〇〇〇〇〇X Processability 〇〇〇〇〇〇X As shown in Table 1, the PSA prepared according to the present invention (Examples 1 to 5) comprises a first layer of 5 PSA layer composed of a compound having a positive stress optical coefficient and A second layer of PSA layer composed of an adhesive film having excellent durability and reworkability, which is superior to the resins of Comparative Examples 1 and 2 in durability, light transmittance uniformity, cuttability, And reworkability is better. As described above, the acrylic PSA component of the present invention can reduce the birefringence caused by shrinkage of the polarizing film adhered to the liquid crystal display panel, so that the properties such as PSA, durability, and cuttability can be sacrificed without sacrificing. In the case of important properties, the problem of light leakage of the liquid crystal display panel is solved. -25-

Claims (1)

Continuation of the scope of the patent application, or a bridging bond connecting the cores of naphthalene or anthracene (wherein R and R2 are selected from the group consisting of Ci to C2, a methoxy group, and an aryl group, respectively) Substituents); and a and b are integers up to 3 (if a = 〇, b is an integer from 1 to 3; otherwise b is an integer from 〇 to 3). 2. The acrylic PSA component according to claim 1, wherein the aromatic compound represented by Chemical Formula 1 or Chemical Formula 2 is from the group of stupid, trans-di-vinyl, azobenzene, p-terphenyl, M-terphenyl, cumene benzoate, diphenylacetylene, 4-ethyldiphenyl, 4,-phenyl-4-diphenylcarbonitrile, 4-diphenylcarbonitrile, 4,_ Phenyldiphenyl, 4,-phenoxydiphenylcarbonitrile, 4'-hexyl-4-diphenylcarbonitrile, 4,-octyl-4-diphenylcarbonitrile, trans-4-xin Composition of 4'-ethoxystilbene, naphthalene, anthracene, 4,-methoxybenzylideneaminodiphenylene, 4,-decyloxybenzylideneaminoazobenzene, and mixtures thereof The selected user in the group. 3. The acrylic PSA component according to claim 1, wherein the acrylic copolymer of the first PSA layer comprises 75 to 99.89 parts of a group having a C12 alkyl group. A propylene oxime monomer, 1. 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. 4. The acrylic PS component according to claim 1, wherein the multifunctional crosslinking agent is a monoisocyanate crosslinking agent, an epoxy group, a azoridyl crosslinking agent and a metal. One or more compounds selected from the group consisting of chelating crosslinkers; wherein the isocyanate crosslinker is derived from toluene diisocyanate, diphenylmethane diisocyanate, and hexa 1257944 〆~&quot; — , The scope of the patent application continues to be selected from the group consisting of sulfhydryl monoisocyanate and trimethylolpropane. 5. The psA component of acrylic acid according to item i of the patent application, wherein the weight of the S layer further comprises i ^ 丨 (9) parts from 5 (hydrogenated) hydrocarbon resin, (hydrogenated) rosin resin (Hydrogenated) rosin ester resin, (hydrogenated) a one or more tackifier selected from the group consisting of a (hydrogenated) olefin resin, a polymerized rosin resin, and a polymerized rosin vinegar resin. 6. The acrylic PSA component according to claim 1 further comprises a group consisting of an epoxy resin, a hardener, a UV stabilizer, an antioxidant, a 10 colorant, a strengthening agent, and a filler. One or more additives selected for use. 7. The acrylic PSA component according to claim 1, wherein the second PSA layer comprises: 1 part of an acrylic copolymer, and the copolymer comprises 75 to 99.89. a (meth) acrylate monomer having 15 Ci to Cu alkyl groups, 1 to 2 parts by weight of an α, β unsaturated carboxylic acid monomer, and 1 to 5 parts of hydrazine A functional monomer of a hydroxyl group; and a multifunctional isocyanate crosslinking agent having from 1 to 1 part by weight. 8. The acrylic PSA component according to claim 1, wherein the first layer of the PSA layer has a thickness of from 1 Å to 50 μm, and the second layer of the PSA layer has a thickness of from 10 to 20 μm. 9. The prostaglandin psa component according to claim 1, wherein the acrylic acid binder component has a crosslinker density of from 1 to 95%. A -28-1257944 polarizing film comprising a PSA film as described in claim 1 of the patent application. Patent application continuation page -29- 1257944 • ν^η§.:Φ^-; ϊ:;^ : Pick up, apply for patent range...1—· * '” h — an acrylic PSA (pressure-sensitive adhesive) component, which contains: a first PSA layer comprising: 1 to 4 parts by weight of a compound having a positive stress optical coefficient, 0.01 to 10 parts by weight of a multifunctional crosslinking agent, and 1 part by weight of one妓···5 and a second PSA layer comprising an acrylic copolymer; Wherein the compound having a positive stress optical coefficient is an aromatic compound represented by the following chemical structural formula or chemical structural formula 2: Chemical structural formula 1 X, Y, heart, and R2 are respectively alkyl or alkoxy groups from hydrogen, cyanide, chlorine, bromine, hydroxy 15 group, dimethylamine, cumyl, and C to Cm. Substituents selected for the group consisting of aryl groups; A is -CH=N-, -N=N, -n=N(0)-, -COO-, _CH2〇,, -cd^-co, - c〇〇-Ch2-,«.each,_s〇2_, -CH^N^CR^-N^CH-, -C=C-〇(r1).n=c.5 -C=C-®( R1)-CC^ 20 'C = C'&lt;I)(Rl)-i)(R2)-c = C^.c = N-0(Rl)-®(R2)-N = C^ Ld continued The second page (please note and use 顚 when applying for a patent 顚 顚 顚), -26-