KR101716958B1 - Adhesive Composition and Polarizing Plate Comprising the same - Google Patents

Abstract

The present invention relates to an adhesive composition comprising 20 parts by weight to 60 parts by weight of a bisphenol F type epoxy compound, 10 parts by weight to 30 parts by weight of a radical monomer containing two or more acrylate groups; 15 to 45 parts by weight of an oxetane-based compound having at least two oxetanyl groups in the molecule; And from 0.5 to 20 parts by weight of a photo cationic polymerization initiator.

Description

(Adhesive Composition and Polarizing Plate Comprising the Same)

This specification claims the benefit of Korean Patent Application No. 10-2014-0080095 filed on June 27, 2014, filed with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

The present invention relates to a polarizer comprising an adhesive composition and an adhesive layer formed using the same.

BACKGROUND ART [0002] A polarizing plate is a device for converting natural light into polarized light having a specific vibration direction, and is recently employed in various display devices such as a liquid crystal display and an organic light emitting device.

Such a polarizing plate is generally used as a structure in which a protective film is laminated on one side or both sides of a polarizer made of polyvinyl alcohol (PVA) resin dyed with a dichroic dye or iodine by using an adhesive, Conventionally, triacetyl cellulose (TAC) films have been mainly used as a polarizer protective film. However, the TAC film has a problem that it is easily deformed in a high temperature and high humidity environment. Recently, protective films of various materials capable of replacing TAC films have been developed. For example, protective films such as polyethylene terephthalate (PET), cycloolefin polymer (COP) Or a mixture thereof.

On the other hand, as an adhesive used for attaching the polarizer and the protective film, an aqueous adhesive mainly composed of an aqueous solution of a polyvinyl alcohol resin is used.

However, in the case of the water-based adhesive, when an acrylic film or a COP film other than TAC is used as a protective film, the adhesive strength is weak, so that the use thereof is limited depending on the film material. In addition, in the case of the water-based adhesive, in addition to the problem of defective adhesive force depending on the material, when the material of the protective film applied to both surfaces of the PVA element is different, a problem of curling of the polarizer due to the drying process of the water- Problems such as lowering of physical properties occur. Therefore, a photo-setting type non-aqueous adhesive has been proposed as an alternative to solve the above problems.

However, in the case of a photocurable non-aqueous adhesive, since the adhesive layer generally has a high viscosity, the thickness of the final adhesive layer tends to be thicker than that of the water-based adhesive. Therefore, when a polarizing plate is produced using a photo- There is a problem that defects such as wrinkles are generated in the direction and the longitudinal direction.

Also, Patent Document 1 has been disclosed in the prior art which includes an epoxy resin which does not contain an aromatic ring as a main component as the above-mentioned photo-curing type non-aqueous adhesive. However, when an epoxy resin containing no aromatic ring is contained as a main component, such as the adhesive composition disclosed in Patent Document 1, the heat resistance is low, so that such adhesive composition is applied to a polarizing plate and has a problem that polarizing properties are significantly deteriorated when the adhesive composition is used for a long period of time. In addition, the adhesive composition of Patent Document 1 has poor mechanical properties and is difficult to form when applied to a polarizing plate. Furthermore, since the epoxy resin not containing an aromatic ring as described above is very expensive, the manufacturing cost is increased, and the productivity is lowered.

Japanese Patent Application Laid-Open No. 2004-245925

Disclosure of the Invention The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an adhesive composition which is excellent in heat resistance and mechanical properties and can improve the ease of production of a polarizing plate, do.

In one embodiment of the present invention, 20 parts by weight to 60 parts by weight of a bisphenol F type epoxy compound is added to 100 parts by weight of the total adhesive composition; 10 parts by weight to 30 parts by weight of a radical monomer containing two or more acrylate groups; 15 to 45 parts by weight of an oxetane-based compound having at least two oxetanyl groups in the molecule; And from 0.5 to 20 parts by weight of a photo cationic polymerization initiator.

According to an embodiment of the present invention, the bisphenol F type epoxy compound may have an epoxy equivalent of 120 g / eq or more and a viscosity of 3000 cPs to 10,000 cPs at 25 ° C.

Further, according to one embodiment of the present invention, the oxetane-based compound having two or more oxetanyl groups in the molecule is (3-ethyl-3 - [(3-ethyloxetan-3- yl) methoxymethyl] Cetane, 1,4-bis [(3-ethyloxetan-3-yl) methoxymethyl] benzene, 1,4-bis [ -Bis [(3-ethyloxetan-3-yl) methoxy] benzene, 4,4'-bis [(3 3-yl) methoxy] biphenyl, 2,2'-bis [(3-ethyloxetane-3-yl) methoxy] biphenyl, 3,3 ', 5,5'-tetra Bis (3-ethyloxetan-3-yl) methoxy] naphthalene, bis [ Methoxy} phenyl] methane, bis [2 - {(3-ethyloxetane-3-yl) methoxy} phenyl] methane, 2,2- 4 - {(3-ethyloxetan-3-yl) methoxy} phenyl] propane, novolac phenol-formaldehyde resin 3-chloromethyl (3-ethyloxetan-3-yl) methoxymethyl] -tricyclo [5.2.1.0 < 2,6 > ] Decane, 2,3-bis [(3-ethyloxetan-3-yl) methoxymethyl] norborane, 1,1,1-tris [(3-ethyloxetan-3- yl) methoxymethyl Propane, 1-butoxy-2,2-bis [(3-ethyloxetan-3-yl) methoxymethyl] butane, 1,2- ) Methoxy} ethylthio] ethane, bis [{4- (3-ethyloxetan-3-yl) methylthio} phenyl] sulfide and 1,6- Methoxy] -2,2,3,3,4,4,5,5-octafluorohexane can be used.

Meanwhile, the viscosity of the adhesive composition according to one embodiment of the present invention may be 10 cP to 100 cP.

Another embodiment of the present disclosure is a polarizer comprising: a polarizer; An adhesive layer formed on at least one surface of the polarizer; And a transparent base film formed on the adhesive layer, wherein the adhesive layer is formed by the adhesive composition according to the present invention, and the thickness of the adhesive layer is more than 0 탆 and 10 탆.

According to an embodiment of the present invention, the peeling force between the adhesive layer and the transparent base film is 2N to 5N at a peeling angle of 90 °, and the glass transition temperature of the adhesive layer is preferably 70 ° C or more.

Also, according to one embodiment of the present invention, the thickness of the polarizing plate according to the present invention is preferably 50 탆 to 200 탆.

The adhesive composition according to one embodiment of the present invention has excellent heat resistance, and the polarizing plate to which the adhesive composition is applied has excellent polarizing properties even when it is used for a long time. In addition, since the adhesive composition has excellent mechanical properties and is easily applied to a polarizing plate, the productivity of the polarizing plate can be improved.

On the other hand, the adhesive composition according to one embodiment of the present invention has a low viscosity, so that it is excellent in workability and can form a thin adhesive layer, so that the thickness of the polarizer can be made thin as a result. Furthermore, since the production unit cost can be reduced, it is also highly economical.

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are also provided to more fully describe the present invention to those skilled in the art.

The inventors of the present invention have conducted intensive studies to develop an adhesive composition having a low viscosity and excellent heat resistance and mechanical properties. As a result, it has been found that a bisphenol F type epoxy compound is used as a main component and a polyfunctional radical monomer, Or more and an oxetane-based compound having an oxetanyl group and a photo cationic polymerization initiator, the adhesive composition of the present invention has been developed.

More specifically, the adhesive composition of the present invention comprises 20 to 60 parts by weight of a bisphenol F type epoxy compound per 100 parts by weight of the total adhesive composition; 10 parts by weight to 30 parts by weight of a radical monomer containing two or more acrylate groups; 15 to 45 parts by weight of an oxetane-based compound having at least two oxetanyl groups in the molecule; And 0.5 to 20 parts by weight of a photo cationic polymerization initiator.

According to one embodiment of the present invention, the bisphenol F type epoxy compound is capable of controlling the viscosity of the adhesive composition according to the present invention and improving the heat resistance. For example, the bisphenol F type epoxy compound has an epoxy group at both ends, EEW, Epoxy Equivalent Weight) of 120 g / eq or more. More specifically, for example, the epoxy equivalent of the bisphenol F epoxy compound may be from 120 g / eq to 500 g / eq, more preferably from 120 g / eq to 300 g / eq and from 170 g / eq to 180 g / eq Is most preferable. When the epoxy equivalent of the bisphenol F type epoxy compound satisfies the above numerical range, since the epoxy substitution is relatively large at the same molecular weight, the possibility of participating in the crosslinking reaction of the bisphenol F type epoxy compound is relatively high, The reaction rate can be improved.

According to one embodiment of the present invention, the viscosity of the bisphenol F type epoxy compound is preferably 3,000 cPs to 10,000 cPs or 5,000 cPs to 7,000 cPs.

In the present specification, the epoxy equivalent is a value measured in accordance with JIS K-7236, which means the number of gums of resin containing 1 g equivalent of epoxy resin, and the viscosity is the viscosity at 25 캜.

Since the adhesive composition of the present invention includes the bisphenol F type epoxy compound as described above, the production cost is lower than that of the conventional adhesive composition containing an epoxy compound containing no aromatic ring as a main component, So it is very advantageous.

The bisphenol F type epoxy compound may be used in an amount of 20 to 60 parts by weight, 25 to 60 parts by weight or 30 to 58 parts by weight based on 100 parts by weight of the total adhesive composition. When the content of the bisphenol F type epoxy compound is 20 parts by weight or more based on 100 parts by weight of the total adhesive composition, the adhesive strength of the adhesive composition according to the present invention can be further improved, and the durability of the adhesive layer formed using the adhesive composition great. When the content of the bisphenol F type epoxy compound is 60 parts by weight or less, an adhesive composition having a low viscosity can be obtained. Therefore, when the bisphenol F type epoxy compound is applied to an optical film, the coating property is excellent and workability can be improved remarkably.

Next, the radical monomer containing two or more acrylate groups is for improving the adhesive strength, and is not particularly limited as long as it contains two or less reactive functional groups per molecule.

More specifically, for example, the radical monomer may be selected from 1,9-nonanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (1000) diacrylate, di Ethylene glycol diacrylate, triethylene glycol diacrylate, 1,6-hexanediol ethoxylate diacrylate, and the like, but is not limited thereto.

According to one embodiment of the present invention, the content of the radical monomer having two or more acrylate groups is 10 parts by weight to 30 parts by weight, 15 parts by weight to 27 parts by weight or 17 parts by weight, Parts by weight to 25 parts by weight. When bisphenol F type epoxy resin alone is used, since the reactivity is low, there is a problem that full curing is not performed in the course of curing after forming the adhesive layer. However, when a radical monomer having a content in the above-mentioned numerical range is used together with a bisphenol F type epoxy resin, the reaction rate can be improved, so that complete curing is achieved. As a result, in the step of curing the adhesive composition in the production of a polarizing plate, Can also be cured.

Specifically, according to one embodiment of the present invention, the content of the radical monomer having two or more acrylate groups may be 10 parts by weight or more and 30 parts by weight or less based on 100 parts by weight of the total adhesive composition.

According to one embodiment of the present invention, when the content of the radical monomer containing two or more acrylate groups is 10 parts by weight or less based on 100 parts by weight of the total adhesive composition, the curing rate is lowered, and after full aging, However, when the amount is more than 30 parts by weight, there is a problem that the adhesive strength to the substrate is lowered.

Meanwhile, in the adhesive composition of the present invention, the oxetane-based compound is intended to lower the viscosity of the adhesive composition, and is not particularly limited as long as it has at least two oxetanyl groups in the molecule. Various oxetane compounds Can be used.

More specifically, the oxetane compound having two or more oxetanyl groups in the molecule is, for example, (3-ethyl-3 - [(3-ethyloxetan-3-yl) methoxymethyl] oxetane, Benzene, 1,4-bis [(3-ethyloxetan-3-yl) methoxy] benzene, 1,3-bis Methoxy] benzene, 4,4'-bis [(3-ethyloxetane-3-yl) methoxy] 3-yl) methoxy] biphenyl, 2,2'-bis [(3-ethyloxetan-3- yl) methoxy] biphenyl, 3,3 ', 5,5'- Bis [(3-ethyloxetan-3-yl) methoxy] naphthalene, bis [4- Methoxy} phenyl] methane, bis [2- (3-ethyloxetane-3-yl) methoxy} phenyl] methane, 2,2- (3-ethyloxetan-3-yl) methoxy} phenyl] propane, 3-chloromethyl-3-ethyloxetane of novolak type phenol-formaldehyde resin (3-ethyloxetan-3-yl) methoxymethyl] -tricyclo [5.2.1.0 2,6] decane, 2,3- Methoxyethyl] norbornane, 1,1,1-tris [(3-ethyloxetan-3-yl) methoxymethyl] propane, 1-butoxy Methoxymethyl] butane, 1,2-bis [{2- (3-ethyloxetan-3-yl) methoxy} ethylthio] Ethane, bis [{4- (3-ethyloxetan-3-yl) methylthio} phenyl] sulfide, 1,6-bis [ , 3,3,4,4,5,5-octafluorohexane, but is not limited thereto.

The content of the oxetane compound having two or more oxetanyl groups in the molecule is 15 to 45 parts by weight, 20 to 40 parts by weight, or 25 to 38 parts by weight based on 100 parts by weight of the total adhesive composition Can be. When the content of the oxetane compound having two or more oxetanyl groups in the molecule satisfies the above-described numerical range, the adhesive composition according to the present invention having the oxetane compound has a viscosity ranging from 10 cP to 100 cP, Since the coating property is excellent, workability can be further improved.

Next, the photo cationic polymerization initiator is a compound which produces a cationic species or a Lewis acid by irradiation of an active energy ray such as visible light, ultraviolet ray, X-ray or electron beam. The photocationic polymerization initiator may be a compound represented by the above-mentioned bisphenol F type epoxy compound Thereby initiating the polymerization reaction. Examples of the polymerization initiator include, but are not limited to, aromatic diazonium salts, onium salts such as aromatic iodo aluminum salts and aromatic sulfonium salts, and iron-arene complexing agents.

On the other hand, the content of the photo-cationic polymerization initiator may be 0.5 to 20 parts by weight, 0.5 to 15 parts by weight, or 0.5 to 10 parts by weight based on 100 parts by weight of the total adhesive composition. When the content of the cationic photopolymerization initiator is more than 20 parts by weight based on 100 parts by weight of the total adhesive composition, polymers having a low molecular weight are produced. Therefore, compared with the case where a polymer having a high molecular weight is produced, Abrasion resistance and the like.

The adhesive composition of the present invention may further contain a photosensitizer, an antioxidant, an oligomer and an adhesion promoter, and may further include urethane acrylate in an amount of more than 0 and not more than 4 parts by weight, . When the urethane acrylate is added as described above, the viscosity tends to increase, but the increased viscosity of the adhesive can be lowered by applying a temperature. On the other hand, when urethane acrylate is added as described above, a more appropriate adhesive force can be imparted to the acrylic film.

On the other hand, the viscosity of the adhesive composition according to the present invention including the above-described composition may be 10 cP to 100 cP, 15 cP to 80 cP, or 20 cP to 60 cP. When the viscosity of the adhesive composition satisfies the above-described numerical value range, it is advantageous in that the workability can be improved since the coating property is excellent.

Next, a polarizing plate including an adhesive layer formed using the above adhesive composition will be described.

A polarizing plate according to the present invention includes: a polarizer; An adhesive layer formed on at least one surface of the polarizer; And a transparent base film formed on the adhesive layer, wherein the adhesive layer is formed by the adhesive composition according to the present invention, and the thickness of the adhesive layer is more than 0 占 퐉 and 10 占 퐉.

At this time, as the polarizer, a polyvinyl alcohol (PVA) based resin film in which molecular chains containing an iodine compound or a dichroic dye are oriented in a certain direction may be used. When the polarizer is a polyvinyl alcohol-based film, the polyvinyl alcohol-based film may be used without any particular limitation as far as it contains a polyvinyl alcohol resin or a derivative thereof. At this time, derivatives of the polyvinyl alcohol resin include, but are not limited to, polyvinyl formal resins and polyvinyl acetal resins.

More specifically, the polarizer can be produced by dying iodine or dichroic dye into a polyvinyl alcohol-based resin film, stretching it in a certain direction, and crosslinking it, but the production method thereof is not particularly limited. The degree of polymerization of the polyvinyl alcohol is not particularly limited, but is preferably 1,000 to 10,000, more preferably 1,500 to 5,000. When the degree of polymerization satisfies the above range, molecular motion is free and can be mixed with iodine or dichroic dyes and the like in a flexible manner.

Meanwhile, in the present specification, the polarizer means a state not including a protective film (or a protective layer), and the polarizer means a state including a polarizer and a protective film (or a protective layer).

Next, an adhesive layer formed by using the above-mentioned adhesive composition is formed on at least one surface of the polarizer. At this time, the thickness of the adhesive layer may be more than 0 μm to 10 μm, more than 0.1 μm to 7 μm or 0.1 μm to 5 μm. When the thickness of the adhesive layer satisfies the above numerical range, a thin adhesive layer can be formed with sufficient adhesion, which is advantageous for thinning the polarizing plate.

In addition, the glass transition temperature (Tg) of the adhesive layer is preferably 70 ° C or more. More specifically, the glass transition temperature of the adhesive layer may be from 75 캜 to 500 캜, from 80 캜 to 300 캜, or from 90 캜 to 150 캜. In the present specification, the glass transition temperature is a value measured by a method of raising the temperature from -30 ° C to 150 ° C by 1 ° C / mint by using the DMA measurement method.

According to the study by the present inventors, it was found that when the glass transition temperature of the adhesive layer is 70 ° C or higher, as compared with the case where the glass transition temperature is lower than 70 ° C, the evaluation of durability The appearance, the adhesive force, the occurrence of cracks, and the optical characteristics of the polarizing plate were confirmed.

On the other hand, the method of forming the adhesive layer may be performed by a method well known in the art, and is not particularly limited as long as the required amount of the adhesive composition can be uniformly applied. More specifically, the adhesive layer may be formed by applying the above-described adhesive composition on at least one surface of a polarizer using a roll coater, a gravure coater, a bar coater, a knife coater, a capillary coater or the like, , A method of laminating them by heating with a plywood roll or by pressing at room temperature, or a method of curing the adhesive composition by irradiating an active energy ray after laminating. At this time, the adhesive composition may be coated on at least one side of the transparent base film and then laminated with a polarizer.

Here, the active energy rays that can be used include, for example, ultraviolet rays, electron beams, microwaves, infrared rays (IR), X-rays and gamma rays as well as alpha-particle beams, a proton beam, and a neutron beam, and ultraviolet rays or electron beams may be used.

On the other hand, the transparent base film may be a compensation film for compensating the optical characteristics of a polarizer protective film or a polarizer, and a polymer film known in the art may be used. More specifically, protective films of various materials generally known in the art, for example, triacetylcellulose (TAC), polyethylene terephthalate (PET) film, cycloolefin polymer (COP , cycloolefin polymer film, acrylic film, and the like can be used without limitation.

At this time, the triacetyl cellulose film may be a resin in which components other than acetic acid are used in combination with cellulose, such as cellulose acetate propionate and cellulose acetate butyrate, to form esters with cellulose, in addition to pure triacetylcellulose. In addition, the transparent base film may contain cellulose lower fatty acid ester resin other than triacetyl cellulose, such as diacetyl cellulose, if necessary.

On the other hand, an acrylic film usable in the present invention can be obtained by molding a molding material containing an acrylic resin as a main component by extrusion molding. Here, the acrylic resin refers to a film containing a resin containing an acrylate-based unit and / or a methacrylate-based unit as a main component, and is not limited to a homopolymer resin composed of an acrylate-based unit or a methacrylate- A film containing a copolymer resin in which other monomer units other than acrylate-based units and / or methacrylate-based units are copolymerized as a main component and a film formed by a blend resin blended with another resin in the acrylic resin as described above to be.

The acrylic film may be a copolymer including, for example, an alkyl (meth) acrylate unit and a styrene unit; And a film comprising an aromatic resin having a carbonate moiety in the main chain, a film comprising an alkyl (meth) acrylate-based unit and a 3- to 6-membered heterocyclic unit substituted with at least one carbonyl group, or a film comprising an alkyl (meth) , A styrene-based unit, a 3- to 6-membered heterocyclic unit substituted with at least one carbonyl group, and a vinyl cyanide unit. Further, it may be an acrylic film having a lactone structure.

Examples of the monomer unit copolymerizable with the acrylic resin may include an aromatic vinyl unit, a 3- to 6-membered heterocyclic unit substituted with a carbonyl group, an acrylic acid unit, a glycidyl unit, and the like. The aromatic vinyl-based unit is, for example, a unit derived from styrene,? -Methylstyrene, etc., and the 3- to 6-membered heterocyclic unit substituted with the carbonyl group is, for example, a lactone ring, glutaric acid Anhydride, glutarimide, maleimide, maleic anhydride, and the like.

For example, the acrylic film may be a film comprising a copolymer comprising an alkyl (meth) acrylate-based unit and a 3- to 10-membered heterocyclic unit substituted with at least one carbonyl group. The 3 to 10 membered heterocyclic unit substituted with the carbonyl group may be a lactone ring, glutaric anhydride, glutarimide, maleic anhydride, maleimide, or the like.

Another example of the acrylic film is a film comprising a blending resin blended with an aromatic resin having a carbonate moiety in the main chain of the acrylic resin. At this time, the aromatic resin having a carbonate moiety in the main chain may be, for example, polycarbonate resin, phenoxy resin, or the like.

The acrylic film is not particularly limited and may be prepared by, for example, thoroughly mixing an acrylic resin, other polymers, additives, and the like by any appropriate mixing method to prepare a thermoplastic resin composition, Acrylic resin, other polymer, additive, or the like may be prepared as a separate solution and then mixed to form a homogeneous mixture solution, which may then be film-formed. As the film forming method, any suitable film forming method such as a solution casting method (solution casting method), a melt extrusion method, a calendering method, a compression molding method and the like can be used.

On the other hand, if necessary, the transparent base film may be subjected to a surface treatment for improving the adhesion strength. For example, at least one surface of the transparent base film may have at least one surface selected from the group consisting of alkali treatment, corona treatment and plasma treatment Processing can be performed.

On the other hand, the peeling force between the adhesive layer and the transparent base film formed as described above can be 2N or more at a peeling angle of 90 °. More specifically, the peeling force may be 2N to 5N or 2N to 4N. In this specification, the peeling force between the adhesive layer and the transparent base film refers to a value measured by a method of peeling at 90 deg. At a speed of 300 m / min using a polarizing plate on which an adhesive layer having a width of 20 mm and a length of 100 mm is formed. At this time, the surface to be peeled may be the interface between the adhesive layer and the transparent base film or the interface between the polarizer and the adhesive layer.

Further, the thickness of the polarizing plate according to the present invention may be 50 탆 to 200 탆, 60 탆 to 150 탆 or 70 탆 to 120 탆. When the thickness of the polarizing plate satisfies the above-described numerical range, it can be applied to various display devices since it conforms to the recent trend of thinning of the polarizing plate.

As described above, since the adhesive composition according to the present invention has excellent heat resistance, it has excellent durability because it has excellent polarization degree even when it is used for a long time under a high temperature atmosphere. In addition, since the polarizer can be easily applied to a polarizer and has a low viscosity due to its excellent mechanical properties, an adhesive layer can be easily formed on a polarizer or a transparent substrate film, and a thin adhesive layer can be formed.

On the other hand, the polarizing plate of the present invention including the adhesive layer formed using the adhesive composition as described above can be applied to an image display device such as a liquid crystal display device and the like. The image display device may be, for example, a liquid crystal display device including a liquid crystal panel and polarizing plates provided on both sides of the liquid crystal panel, and at least one of the polarizing plates may be a polarizing plate according to the present invention. At this time, the type of the liquid crystal panel included in the liquid crystal display device is not particularly limited. A passive matrix type panel such as a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferroelectic (F) type or a polymer dispersed (PD) type; An active matrix type panel such as a two terminal or a three terminal; A known panel such as an in-plane switching (IPS) panel and a vertical alignment (VA) panel may be used. The types of the other constituent elements constituting the liquid crystal display device, for example, the types of the upper and lower substrates (e.g., color filter substrate or array substrate) are not particularly limited, and configurations known in this field are not limited .

Production Example 1

30% by weight (DOA Kosei OXT-221), 3% by weight of bisphenol F type epoxy (DER DER), 3-ethyl-3- [ , And 30 wt% of 9-nonanediol diacrylate (NK ESTER Corporation A-NOD-N) were added to 100 parts by weight of the resin composition, and 5 wt% of a cationic initiator, CPI 100P (Sanapro) .

Production Example 2

20 wt% (DOA Kosei Co., Ltd. OXT-221), 1 wt% of bisphenol F type epoxy (DOW DER), 3-ethyl-3- [ And 20 wt% of 9-nonanediol diacrylate (NK ESTER Corporation A-NOD-N) were added to 100 parts by weight of the resin composition, and 5 wt% of a cationic initiator CPI 100P (Sanapro) .

Production Example 3

An adhesive composition C was prepared in the same manner as in Example 1, except that 40 wt% of bisphenol A type epoxy (DOW Corp. D.E.R) was used instead of bisphenol F type epoxy.

Production Example 4

Except that 40 wt% of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (Celloxide 2021P, manufactured by Daicel) was used in place of bisphenol F type epoxy, and the adhesive composition D .

Production Example 5

30% by weight of a bisphenol A epoxy (DOW Corporation DER), 3-ethyl-3 - [(3-ethyloxetane-3-yl) methoxymethyl] oxetane , 30 weight% of 9-nonanediol diacrylate (NK ESTER A-NOD-N) and 4 weight% of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (Celloxide 2021P ) Was added to 100 parts by weight of the resin composition, and 5% by weight of CPI 100P (Sanapro) as a cation initiator was added to prepare an adhesive composition E.

Production Example 6

30% by weight (DOA Kosei OXT-221), 3% by weight of bisphenol F type epoxy (DER DER), 3-ethyl-3- [ , And 30 wt% of 9-nonanediol diacrylate (NK ESTER Corporation A-NOD-N) were added to 100 parts by weight of the resin composition, and 5 wt% of a cationic initiator CPI 100P (Sanapro) .

Production Example 7

30% by weight (DOA Kosei OXT-221), 3% by weight of bisphenol F type epoxy (DER DER), 3-ethyl-3- [ , 10 wt% of 9-nonanediol diacrylate (NK ESTER Corporation A-NOD-N), and 5 wt% of CPI 100P (Sanapro) as a cation initiator was added to 100 parts of the resin composition, .

Production Example 8

30% by weight (DOA Kosei OXT-221), 3% by weight of bisphenol F type epoxy (DER DER), 3-ethyl-3- [ , 5 wt% of a cationic initiator CPI 100P (Sanapro) was added to 100 weight parts of the resin composition prepared by adding 45 wt% of 9-nonanediol diacrylate (NK ESTER Company A-NOD-N) .

Example 1

(1) Production of acrylic film

A resin composition obtained by uniformly mixing poly (N-cyclohexylmaleimide-co-methylmethacrylate), styrene-maleic anhydride copolymer resin and phenoxystyrene resin at a weight ratio of 100: 2.5: To an extruder was fed to an extruder of 24φ substituted with nitrogen and melted at 250 ° C to prepare a raw material pellet.

The styrene-maleic anhydride copolymer resin contained 85% by weight of styrene, 15% by weight of maleic anhydride hydrate, and the weight average molecular weight (Mw) , And poly (N-cyclohexylmaleimide-co-methylmethacrylate) resin had a content of N-cyclohexylmaleimide of 6.5% by weight by NMR analysis.

The obtained raw material pellets were dried in vacuo, melted in an extruder at 260 占 폚, passed through a coat hanger type T-die, and a film having a thickness of 150 占 퐉 was produced through a chrome casting roll and a drying roll. The film was stretched at a rate of 170% using a pylot stretching machine at 125 DEG C in the MD direction using the speed difference of rolls to produce an acrylic film.

The acrylic film prepared through the above process was corona-treated, and then a primer composition having a solid content of 10 wt% prepared by diluting CK-PUD-F (dim light urethane dispersion) with pure water on one side of the acrylic film, 10 parts by weight of a crosslinking agent (Nippon Synthetic Chemical Co., Ltd., Cabodilite SV-02) was coated with # 7 bar and stretched in the TD direction at 130 캜 using a tenter to obtain a primer layer thickness Lt; RTI ID = 0.0 > 400nm. ≪ / RTI >

(2) Production of Polarizer

Using the microgravure coater, the adhesive composition A prepared in Preparation Example 1 was coated on the primer layer of two sheets of the acrylic film prepared in the above (1) so that the thickness of the final adhesive layer was 1 占 퐉. Then, two acrylic films coated with the adhesive composition were laminated on both sides of the PVA element, and ultraviolet rays of 500 mJ / cm < 2 > were radiated from one side of the PVA element by using a metal halide lamp, .

Example 2

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition B prepared in Preparation Example 2 was used.

Example 3

Treated with NRT (Konica Corp.) by heating the substrate to 40 ° C to 60 ° C at a concentration of 10% KOH to saponify the substrate.

Next, using the microgravure coater, the adhesive composition A prepared in Preparation Example 1 was coated on the two pretreated NRT substrates so that the thickness of the final adhesive layer was 1 占 퐉. Then, two NRT substrates coated with the adhesive composition were laminated on both sides of the PVA device, and ultraviolet rays of 500 mJ / cm < ² > were irradiated from the side of one side of the PVA device using a metal halide lamp, .

Example 4

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition B prepared in Preparation Example 2 was used.

Example 5

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition F prepared in Preparation Example 6 was used.

Example 6

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition F prepared in Preparation Example 6 was used.

Comparative Example 1

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition C prepared in Preparation Example 3 was used.

Comparative Example 2

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition D prepared in Preparation Example 4 was used.

Comparative Example 3

A polarizing plate was prepared in the same manner as in Example 1, except that the adhesive composition E prepared in Preparation Example 5 was used.

Comparative Example 4

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition C prepared in Preparation Example 3 was used.

Comparative Example 5

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition D prepared in Preparation Example 4 was used.

Comparative Example 6

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition E prepared in Preparation Example 5 was used.

Comparative Example 7

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition G prepared in Preparation Example 7 was used.

Comparative Example 8

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition G prepared in Preparation Example 7 was used.

Comparative Example 9

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition H prepared in Preparation Example 8 was used.

Comparative Example 10

A polarizing plate was produced in the same manner as in Example 3, except that the adhesive composition H prepared in Preparation Example 8 was used.

Experimental Example 1

1. Evaluation of peel strength

The peeling force between the adhesive layer and the film was measured in the polarizing plate produced in Examples 1 to 4 and Comparative Examples 1 to 6. The peeling force is measured when the polarizing plate having a width of 20 mm and a length of 15 mm is used and the opposite film is peeled off at a speed of 300 mm / min and 90 °. As a result, the case where the peeling force is 2N / 20 mm or more is indicated as NG and the case where it is less than 2N / 20 mm is indicated as NG.

2. Evaluation of Coating Property

In the polarizing plate manufacturing processes of Examples 1 to 4 and Comparative Examples 1 to 6, the adhesive composition was coated on the NRT substrate pretreated with acrylic primer layer or KOH with # 3 bar and then wetted Respectively. NG when the dewetting portion exceeds 5 mm, and OK when the dewetting portion is 5 mm or less.

division glue materials Peel force Coating property Viscosity (cP) Example 1 A acryl OK OK 33 Example 2 B acryl OK OK 70 Example 3 A NRT OK OK - Example 4 B NRT OK OK - Comparative Example 1 C acryl OK NG 47 Comparative Example 2 D acryl NG OK 24 Comparative Example 3 E acryl OK NG - Comparative Example 4 C NRT OK NG - Comparative Example 5 D NRT NG OK - Comparative Example 6 E NRT NG OK 50

As shown in Table 1, in the case of the polarizing plate using the adhesive composition of the present invention according to Examples 1 to 4 containing an epoxy resin containing an aromatic ring as a main component, it was found that the peeling force and the coating property were all excellent there was. However, in the case of the polarizing plate according to Comparative Examples 1 to 6 using an epoxy resin containing an aromatic ring as a main component or an adhesive composition using a bisphenol A type epoxy resin as a main component, there is a problem in either peeling force or coating property .

Experimental Example 2

1. Evaluation of peel strength

The peeling force between the adhesive layer and the film was measured in the polarizing plate produced in Examples 5 and 6 and Comparative Examples 7 to 10. The peeling force is measured when the polarizing plate having a width of 20 mm and a length of 15 mm is used and the opposite film is peeled off at a speed of 300 mm / min and 90 °. As a result, the case where the peeling force is 2N / 20 mm or more is indicated as NG and the case where it is less than 2N / 20 mm is indicated as NG.

2. Evaluation of hardening rate

For the measurement of the curing rate, the polarizer is cured after applying the prescription in the NRT / PVA / NRT structure. Cations are not cured immediately after exposure because they have a slower curing rate than radicals. 2nd layer The degree of stickiness of the prescription between NRT and PVA is rubbed with a latex wearing hand to confirm the fluidity of the prescription. We confirmed the curing rate based on the point at which the fluidity disappears.

division glue materials Peel force Hardening speed Example 5 F acryl OK 100% Example 6 F NRT OK 100% Comparative Example 7 G acryl NG 200% Comparative Example 8 G NRT OK 200% Comparative Example 9 H acryl NG 70% Comparative Example 10 H NRT NG 70%

As shown in Table 2, in the case of Examples 5 and 6 in which the radical monomer having two or more acrylate groups was contained in an amount of 10 parts by weight or more and 30 parts by weight or less based on 100 parts by weight of the total adhesive composition, And the curing rate was also suitable. However, in the case of Comparative Examples 7 and 8 in which the radical monomer containing two or more acrylate groups was contained in an amount of 10 parts by weight or less based on 100 parts by weight of the total adhesive composition, it was confirmed that the curing rate was too slow. It was found that there was also a problem in peeling force. In addition, in the case of Comparative Examples 9 and 10 in which the radical monomer containing two or more acrylate groups exceeded 30 parts by weight based on 100 parts by weight of the total adhesive composition, it was found that there was a problem in peel strength.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments, but various modifications and changes may be made without departing from the scope of the invention. To those of ordinary skill in the art.

Claims (12)

With respect to 100 parts by weight of the total adhesive composition,
20 to 60 parts by weight of a bisphenol F type epoxy compound;
10 parts by weight to 30 parts by weight of a radical monomer containing two or more acrylate groups;
15 to 45 parts by weight of an oxetane-based compound having at least two oxetanyl groups in the molecule; And
Wherein the bisphenol F type epoxy compound has an epoxy equivalent of 120 g / eq or more and a viscosity at 25 DEG C of 3,000 cPs to 10,000 cPs. delete delete The method according to claim 1,
Wherein the radical monomer having two or more acrylate groups is contained in an amount of 10 parts by weight or more and 30 parts by weight or less based on 100 parts by weight of the total adhesive composition. The method according to claim 1,
The radical monomer may be selected from the group consisting of 1,9-nonanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (1000) diacrylate, diethylene glycol diacrylate, Ethylene glycol diacrylate, and 1,6-hexanediol ethoxylate diacrylate. The method according to claim 1,
The oxetane-based compound having at least two oxetanyl groups in the molecule may be at least one selected from the group consisting of (3-ethyl-3 - [(3-ethyloxetan-3- yl) methoxymethyl] oxetane, Ethyloxetane-3-yl) methoxymethyl] benzene, 1,4-bis [ Methoxy] benzene, 1,2,4-bis [(3-ethyloxetan-3-yl) methoxy] Biphenyl, 3,3 ', 5,5'-tetramethyl-4,4'-bis [(3-ethyloxetan- 3-yl) methoxy] biphenyl, 2,7-bis [(3-ethyloxetan-3- yl) methoxy] naphthalene, bis [4- { Methoxy) phenyl] methane, bis [2 - {(3-ethyloxetane-3-yl) methoxy} phenyl] methane, 2,2- Methoxy} phenyl] propane, an etherified product of 3-chloromethyl-3-ethyloxetane of a novolac phenol-formaldehyde resin, 3 (4) 8 (9) -bis [(3-ethyloxetan-3-yl) methoxymethyl] -tricyclo [5.2.1.0 2,6] decane, 2,3- Methoxymethyl] norbornane, 1,1,1-tris [(3-ethyloxetan-3-yl) methoxymethyl] propane, 1-butoxy-2,2- Ethyl} oxethyl} ethylthio] ethane, bis [{4- (3-ethyl Oxetan-3-yl) methylthio} phenyl] sulfide and 1,6-bis [(3-ethyloxetan-3- yl) methoxy] -2,2,3,3,4,4,5- Hexafluorohexane, and 5-octafluorohexane. The method according to claim 1,
Wherein the photo-cationic polymerization initiator is a compound which produces a cationic species or a Lewis acid by irradiation with an active energy ray. The method according to claim 1,
Wherein the viscosity of the adhesive composition is 10 cP to 100 cP. A polarizer;
An adhesive layer formed on at least one surface of the polarizer; And
And a transparent base film formed on the adhesive layer, wherein the adhesive layer is formed by the adhesive composition according to any one of claims 1 to 4,
Wherein the thickness of the adhesive layer is more than 0 占 퐉 and 10 占 퐉. 10. The method of claim 9,
Wherein the peeling force between the adhesive layer and the transparent base film is 2N to 5N at a peeling angle of 90 DEG. 10. The method of claim 9,
Wherein the adhesive layer has a glass transition temperature of 70 DEG C or higher. 10. The method of claim 9,
Wherein a thickness of the polarizing plate is 50 占 퐉 to 200 占 퐉.