TWI463197B - Polarizing plate, optical component, and liquid crystal display device - Google Patents

Description

Polarizing plate, optical component, and liquid crystal display device

The present invention relates to a polarizing plate having a protective layer on one or both sides of a polarizing film. Meanwhile, the present invention relates to an optical component using the polarizing plate and a liquid crystal display device.

The polarizing plate can be used as an optical component constituting a liquid crystal display device. In the related art, the polarizing plate is a polarizing plate which is formed by laminating a protective layer formed of a transparent resin film on one surface or both surfaces of a polarizing film. As for such a transparent resin film, a triacetyl cellulose film (TAC film) is often used because of its excellent optical transparency and moisture permeability. The polarizing plate can be attached to the liquid crystal display device after being attached to the liquid crystal cell with an adhesive, as needed, via another optical function layer.

In recent years, with the development of portable devices such as notebook personal computers, mobile phones, and car navigation devices for liquid crystal display devices, the polarizing plates constituting the liquid crystal display device are also thin, lightweight, and high in durability (high mechanical strength). Requirements. At the same time, in the case of a liquid crystal display device for portable use, it is also desirable to use it under moist heat, and for the polarizing plate used therein, high heat and humidity resistance is also required, but the conventional polarizing plate is exposed to high humidity for a long time. Especially in the case of high temperature and high humidity, there is a problem that the polarizing performance is lowered or the polarizing film is shrunk. Therefore, in addition to the thinness and weight reduction of the protective layer laminated on the polarizing film, it is also required to increase the hardness thereof to improve the mechanical strength and the ability to suppress the shrinkage of the polarizing film (shrinkage suppressing force).

However, in the polarizing plate of the TAC film which has been bonded to the protective layer, it is difficult to make the thickness of the protective layer 20 μm or less in terms of handleability and durability at the time of work, and there is a limit to thinness and weight reduction.

For example, Japanese Laid-Open Patent Publication No. 2000-199819 (Patent Document 1) discloses that a resin film is applied to one or both sides of a polarizing film formed of a hydrophilic polymer to form a transparent film. Layer technology. In the Japanese Patent Publication No. 2003-185842 (Patent Document 2), an energy ray hardening composition containing an energy ray polymerizable compound having a dicyclopentyl residue or a dicyclopentenyl residue or the like is disclosed. A technique in which a substance is hardened to form a protective film on a polarizing film. Japanese Laid-Open Patent Publication No. 2004-245924 (Patent Document 3) discloses a polarizing plate having a protective film mainly composed of an epoxy resin on at least one side of a polarizing film. In the Japanese Patent Publication No. 2005-92112 (Patent Document 4), it is disclosed that at least one surface of the polarizing film is protected by a cured product of the active energy ray-curable resin composition.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-199819

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-185842

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-245924

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2005-92112

An object of the present invention is to provide a polarizing plate which is capable of maintaining good adhesion between a polarizing film and a protective layer on the one hand, and which is thin and light in weight and whose hardness of the protective layer is improved. Meanwhile, another object of the present invention is to provide an optical component and a liquid crystal display device using such a polarizing plate.

The polarizing plate of the present invention includes a polarizing film that adsorbs a dichroic dye in a polyvinyl alcohol-based resin film, and a protective layer formed on at least one surface of the polarizing film, and the protective layer is composed of an active energy ray-curable compound. A cured product of a curable resin composition, wherein the active energy ray-curable compound contains a compound having at least one epoxy group in the molecule and at least one (meth) acryloxy group in the molecule (methyl group) An acrylic compound, the protective layer having an elastic modulus of 3,300 to 10,000 MPa.

In the polarizing plate of the present invention, the (meth)acrylic compound is preferably contained in an amount of 10 to 70 parts by weight based on 100 parts by weight of the active energy ray-curable compound.

In the polarizing plate of the present invention, the (meth)acrylic compound is preferably a hardened material formed of only the (meth)acrylic compound and a polymerization initiator to provide an elastic modulus of 3,000 MPa or more.

In the polarizing plate of the present invention, the (meth)acrylic compound is preferably at least one compound represented by the following formulas (1) to (4).

(In the above formulas (1) and (2), Q ₁ and Q ₂ each independently represent a (meth) acryloxy group or a (meth) propylene decyloxy group, and the carbon number of the alkyl group is 1 at this time. To the above formula (2), R represents hydrogen or a hydrocarbon group having 1 to 10 carbon atoms; in the above formula (3), T ₁ , T ₂ and T ₃ each independently represent a (meth) acryloxy group; In the above formula (4), T represents a hydroxyl group or a (meth)acryloxy group).

In the polarizing plate of the present invention, the curable resin composition is preferably a compound containing an oxetane compound.

In the polarizing plate of the present invention, the curable resin composition is preferably one containing fine particles. In this case, the curable resin composition is preferably contained in an amount of 5 to 250 parts by weight based on 100 parts by weight of the active energy ray-curable compound.

In the polarizing plate of the present invention, the fine particles are preferably cerium oxide particles having a particle diameter of 100 nm or less. In this case, the cerium oxide microparticles are more preferably one or more functional groups selected from the group consisting of a hydroxyl group, an epoxy group, a (meth) acryloxy group, and a vinyl group.

In the polarizing plate of the present invention, the thickness of the protective layer is preferably from 1 to 35 μm.

The present invention can simultaneously provide an optical component formed of the laminate of the above-described polarizing plate and optical functional layer of the present invention. The optical functional layer in the optical module of the present invention is preferably any one of a retardation layer, a brightness enhancement film, and a surface treatment layer.

The present invention further provides a liquid crystal display device in which the polarizing plate of the present invention or the optical module of the present invention described above is disposed on one surface or both surfaces of a liquid crystal cell.

According to the present invention, since the thickness of the protective layer can be made smaller than that of the conventional TAC film or the like, the polarizing plate can be made thinner and lighter, and the adhesion between the polarizing film and the protective layer is good. Further, since the hardness of the protective layer can be increased, the mechanical strength of the polarizing plate can be improved, and even when the thickness of the protective layer is reduced as compared with the prior art, the shrinkage of the polarizing film can be effectively suppressed under high temperature and high humidity. The polarizing plate of the present invention and the optical component using the polarizing plate are very suitable for, for example, a liquid crystal display device for portable use.

<Polarizing plate>

The polarizing plate of the present invention has a polarizing film in which a dichroic dye is adsorbed on a polyvinyl alcohol resin film, and a protective layer formed on one or both sides of the polarizing film. The protective layer is contained. A cured product of a curable resin composition of an active energy ray-curable compound is formed. In the polarizing plate of the present invention, the active energy ray-curable compound used in the protective layer contains a compound having at least one epoxy group in the molecule and at least one (meth) acryloxy group in the molecule (A) The acrylic compound, and the protective layer has an elastic modulus of 3,300 to 10,000 MPa. Meanwhile, the "elasticity ratio" in the present specification means the tensile modulus at room temperature (about 23 ° C) unless otherwise specified. Hereinafter, the polarizing plate of the present invention will be described in detail.

The polarizing film used in the present invention is formed of a polyvinyl alcohol-based resin, and specifically, a dichroic dye is adsorbed and oriented to a uniaxially stretched polyvinyl alcohol-based resin film.

The polyvinyl alcohol-based resin constituting the polarizing film can be obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate of a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is also available. As the other monomer copolymerizable with vinyl acetate, for example, an unsaturated carboxylic acid, an unsaturated sulfonic acid, an olefin, or a vinyl ether can be mentioned. The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, and preferably 98 to 100 mol%. The polyvinyl alcohol-based resin may also be modified, and for example, an aldehyde-modified polyvinyl formal or polyvinyl acetal may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, and preferably about 1,500 to 10,000.

As the film made of such a polyvinyl alcohol-based resin, an original film as a polarizing film can be used. The method of forming the film of the polyvinyl alcohol-based resin is not particularly limited, and a known method can be used. The thickness of the original sheet film formed of the polyvinyl alcohol-based resin is not particularly limited, and is, for example, about 10 to 150 μm.

The production of the polarizing film is generally a step of uniaxially stretching the original film formed of the above polyvinyl alcohol-based resin, and dyeing the polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye. And a step of treating the polyvinyl alcohol-based resin film having adsorbed the dichroic dye with a boric acid aqueous solution, and a water washing step after the boric acid aqueous solution treatment.

The uniaxial stretching may be carried out before the dyeing with the dichroic dye, or simultaneously with the dyeing, or after the dyeing. When uniaxial stretching is performed after dyeing of the dichroic dye, the uniaxial stretching may be carried out before the boric acid treatment or in the boric acid treatment. Alternatively, uniaxial stretching can be performed at a plurality of stages of such processing. The uniaxial extension can be uniaxially extended between rollers of different peripheral speeds, or it can be extended on a single shaft using a hot roller. Meanwhile, it may be a dry stretching method such as stretching in the atmosphere, or a wet stretching method in which it is extended in a state of being expanded in a solvent. The stretching ratio is usually about 4 to 8 times.

When the polyvinyl alcohol-based resin film is dyed with a dichroic dye, for example, the polyvinyl alcohol-based resin film may be immersed in an aqueous solution containing a dichroic dye. As the dichroic dye, iodine, a dichroic dye or the like can be used. Prior to the dyeing treatment, the polyvinyl alcohol-based resin film is preferably first immersed in water.

When iodine is used as the dichroic dye, a method in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing iodine and potassium iodide is usually used as a method of dyeing. The iodine content in the aqueous solution is usually about 0.01 to 0.5 parts by weight with respect to 100 parts by weight of water; and at the same time, the content of potassium iodide is usually about 0.5 to 10 parts by weight relative to 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C, and the time (dyeing time) of immersion in the solution is usually about 30 to 300 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, the dyeing method is usually a method in which a polyvinyl alcohol-based resin film is immersed in an aqueous dye solution containing a water-soluble dichroic dye. The content of the dichroic dye in the aqueous dye solution is usually from about 1 × 10 ^-3 to 1 × 10 ^-2 parts by weight based on 100 parts by weight of water. An inorganic salt such as sodium sulfate may be contained in the aqueous dye solution as a dyeing assistant. The temperature of the aqueous dyeing solution is usually about 20 to 80 ° C, and the time (dyeing time) of immersion in the aqueous dye solution is usually about 30 to 300 seconds.

The boric acid treatment after dyeing with the dichroic dye is carried out by immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid. The boric acid content in the aqueous solution containing boric acid is usually about 2 to 15 parts by weight, and preferably about 5 to 12 parts by weight, based on 100 parts by weight of water. When iodine is used as the dichroic dye, the aqueous solution containing boric acid is preferably one containing potassium iodide. The potassium iodide content in the aqueous solution containing boric acid is usually about 2 to 20 parts by weight, and preferably about 5 to 15 parts by weight, based on 100 parts by weight of water. The time of immersion in the aqueous solution containing boric acid is usually about 100 to 1,200 seconds, preferably 150 to 600 seconds, and preferably about 200 to 400 seconds. The temperature of the aqueous solution containing boric acid is usually 50 ° C or more, preferably 50 to 85 ° C.

The polyvinyl alcohol-based resin film after the boric acid treatment is usually subjected to a water washing treatment. For example, a boric acid-treated polyvinyl alcohol-based resin film is immersed in water to perform a water washing treatment. The water temperature during the water washing treatment is usually about 5 to 40 ° C, and the immersion time is about 2 to 120 seconds. After washing with water, it is dried to obtain a polarizing film. The drying treatment can be carried out using a hot air dryer or a far infrared heater. The drying temperature is usually about 40 to 100 °C. The drying treatment time is usually about 120 to 600 seconds.

After the above operation, a polarizing film which adsorbs the directional dichroic dye on the uniaxially stretched polyvinyl alcohol resin film can be obtained. The thickness of the polarizing film may be about 5 to 40 μm.

(The protective layer)

In the present invention, a protective layer formed of a cured product of a curable resin composition containing an active energy ray-curable compound is laminated on one surface or both surfaces of the polarizing film to form a polarizing plate. The active energy ray-curable compound in the present invention contains a compound having at least one epoxy group in the molecule (hereinafter, also referred to as "epoxy compound") and at least one (meth) acryloxy group in the molecule ( Methyl)acrylic compound (hereinafter also referred to as "(meth)acrylic compound").

At this time, the elastic modulus of the protective layer is 3,300 to 10,000 MPa, preferably 3,500 to 8,000 MPa. If the elastic modulus of the protective layer is less than 3,300 MPa, the ability to suppress shrinkage of the polarizing film under high temperature and high humidity is lowered, and as a result, the polarizing characteristics are lowered. When the modulus of elasticity of the protective layer exceeds 10,000 MPa, the adhesion between the polarizing film and the protective layer is deteriorated, and thus problems such as peeling of the protective layer may occur.

Further, in the protective layer, in particular, in order to suppress shrinkage of the polarizing film under high temperature conditions, it is preferable that the elastic modulus does not become too low even at a high temperature before and after 80 °C. Specifically, the storage elastic modulus at 80 ° C is preferably in the range of 1,500 to 5,500 MPa. Further, when the tensile modulus at a high temperature of 80 ° C is obtained, especially since it is difficult to accurately measure the length of the sample before and after the test, it can be easily measured at a high temperature here, and approximates the rigidity of the sample. The storage elastic modulus of the concept of tensile modulus.

Since the curable resin composition contains an epoxy compound, it exhibits excellent adhesion to the polarizing film and the retardation film, and is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, and the like. Durable protective layer. Here, the term "compound having one or more epoxy groups in the molecule" as used in the present invention means having one or more epoxy groups in the molecule, and can be activated by an energy ray (for example, ultraviolet rays, visible rays, electron beams, A compound that is hardened by irradiation with X-rays or the like. Meanwhile, the epoxy compound, the (meth)acrylic compound, and the propylene oxide compound described later are collectively referred to as "active energy ray-curable compound".

The epoxy compound is not particularly limited, but is preferably an epoxy compound having no aromatic ring in its molecule in terms of weather resistance, refractive index, cationic polymerizability and the like. The epoxy compound containing no aromatic ring in the molecule may, for example, be a hydrogenated epoxy compound, an aliphatic epoxy compound or an alicyclic epoxy compound.

A hydrogenated epoxy compound can be obtained by selectively hydrogenating an aromatic epoxy compound under pressure in the presence of a catalyst. Examples of the aromatic epoxy compound include bisphenol-type epoxy resins such as bisphenol A bis-dehydroglycerin ether, bisphenol F diglycidyl ether, and bisphenol S diglycidyl ether; and a phenol novolac ring; Phenolic epoxy resin such as oxy resin, cresol novolac epoxy resin, hydroxybenzaldehyde phenol novolac epoxy resin; dehydroglyceryl ether of tetrahydroxyphenylmethane, dehydroglyceryl ether of tetrahydroxybenzophenone, epoxidation A polyfunctional epoxy resin such as polyvinyl phenol. Among them, in the case of hydrogenating the epoxy compound, it is preferred to use the hydrogenated bisphenol A dehydrated ether.

As the aliphatic epoxy compound, for example, a polyglycidyl ether of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof can be mentioned. More specifically, for example, diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerin, or trimethylolpropane Tridehydroglyceryl ether, di-glycidyl ether of polyethylene glycol, di-dehydroglyceryl ether of propylene glycol, and one or more epoxys added to an aliphatic polyol such as ethylene glycol, propylene glycol or glycerin A polyglycidyl ether of a polyether polyol obtained by an alkane (ethylene oxide or propylene oxide) or the like.

The alicyclic epoxy compound means an epoxy compound having at least one epoxy group bonded to an alicyclic ring. The "epoxy group bonded to the alicyclic ring" has a structure in which one or a plurality of hydrogens of (CH ₂ ) _m are removed from the following formula. In the formula, m is an integer of 2 to 5.

Therefore, the alicyclic epoxy compound means a compound having at least one structure represented by the above formula in the molecule. More specifically, the compound represented by the above formula or the compound having a structure in which one or a plurality of hydrogens in (CH ₂ ) _m is removed in the above formula and a group having another chemical structure may be alicyclic. Epoxy compound. One or a plurality of hydrogens of (CH ₂ ) _m may be suitably substituted with a linear alkyl group such as a methyl group or an ethyl group.

Among the epoxy compounds as described above, an alicyclic epoxy compound is preferred, that is, preferably at least one epoxy group is a compound bonded to an alicyclic ring, especially having an oxabicyclohexane (the above formula) The epoxy compound in the case of m=3 or oxabicycloheptane (m=4 in the above formula) is excellent in the elasticity of the cured product and the adhesion to the polarizing film. Layer, and more applicable. Hereinafter, the present invention is not particularly limited to these compounds, although it is a specific example of a structure having an alicyclic epoxy compound in the present invention.

(a) Epoxycyclohexanecarboxylic acid epoxycyclohexylmethyl ester represented by the following formula (I):

(wherein R ¹ and R ² independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms).

(b) an epoxycyclohexane carboxylate of an alkanediol represented by the following formula (II):

(wherein R ³ and R ⁴ independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and n represents an integer of 2 to 20).

(c) Epoxycyclohexylmethyl esters of dicarboxylic acids represented by the following formula (III):

(wherein R ⁵ and R ⁶ independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and p represents an integer of 2 to 20).

(d) Epoxycyclohexyl methyl ether of polyethylene glycol represented by the following formula (IV):

(wherein R ⁷ and R ⁸ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and q represents an integer of 2 to 10).

(e) Epoxycyclohexylmethyl ether of an alkanediol represented by the following formula (V):

(wherein R ⁹ and R ¹⁰ independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and r represents an integer of 2 to 20).

(f) a diepoxy trispirate compound represented by the following formula (VI):

(wherein R ¹¹ and R ¹² independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms).

(g) a diepoxy single spiro compound represented by the following formula (VII):

(wherein R ¹³ and R ¹⁴ independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms).

(h) Ethylene cyclohexene diepoxides represented by the following formula (VIII):

(wherein R ¹⁵ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms).

(i) Epoxycyclopentyl ethers represented by the following formula (IX):

(wherein R ¹⁶ and R ¹⁷ independently of each other represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms).

(j) Dixylene tricyclodecane represented by the following formula (X):

(wherein R ¹⁸ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms).

Among the alicyclic epoxy compounds exemplified above, the following alicyclic epoxy compounds are preferred because they are commercially available or relatively easy to obtain analogs thereof.

(A) Esters of 7-oxabicyclo[4.1.0]heptane-3-carboxylic acid with (7-oxabicyclo[4.1.0]heptan-3-yl)methanol [in formula (I), R ¹ = R ² = H compound], (B) 4-methyl-7-oxabicyclo[4.1.0]heptane-3-carboxylic acid and (4-methyl-7-oxabicyclo[4.1. An esterified product of 0]hept-3-yl)methanol [in the formula (I), a compound of R ¹ =4-CH ₃ , R ² =4-CH ₃ ], (C) 7-oxabicyclo[4.1.0 An esterified product of heptane-3-carboxylic acid and 1,2-ethanediol [in the formula (II), a compound of R ³ = R ⁴ = H, n = 2], (D) (7-oxabicyclo) [4.1.0]Hept-3-yl) esterified product of methanol and adipic acid [in the formula (III), a compound of R ⁵ =R ⁶ =H, p=4], (E)(4-methyl- Esterified product of 7-oxabicyclo[4.1.0]heptan-3-yl)methanol with adipic acid [in the formula (III), R ⁵ =4-CH ₃ , R ⁶ =4-CH ₃ , p=4 Compound], (F) (7-oxabicyclo[4.1.0]heptan-3-yl)methanol and 1,2-ethanediol etherate [in formula (V), R ⁹ =R ¹⁰ =H , compound with r=2].

Each of the epoxy compounds in the present invention may be used singly or in combination of one or more kinds.

In the curable resin composition used in the present invention, in the 100 parts by weight of the active energy ray-curable compound, the proportion of the epoxy compound is preferably 30 to 90 parts by weight, and preferably 35 to 80 parts by weight. The ratio is preferably in the range of 40 to 70 parts by weight. When the content of the epoxy compound is less than 30 parts by weight, the adhesion between the polarizing film and the protective layer tends to decrease, and when it exceeds 90 parts by weight, the optical property is lowered due to yellowing of the protective layer of the cured product. The tendency.

Meanwhile, in addition to the above epoxy compound, the curable resin composition may contain a propylene oxide compound. By the addition of the propylene oxide compound, the viscosity of the curable resin composition can be lowered, and the curing rate can be increased. At the same time, yellowing of the protective layer of the cured product can be prevented, and optical performance is improved.

The propylene oxide compound is a compound having at least one propylene oxide ring (4 membered cyclic ether) in the molecule, and examples thereof include 3-ethyl-3-hydroxymethyl propylene oxide and 1,4-bis[(3- Ethyl-3-epoxypropenyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)epoxypropane, bis[(3-ethyl-3-epoxypropane) ) methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl) propylene oxide, phenol novolac propylene oxide, and the like. Such a propylene oxide compound can be easily obtained from commercially available products, and examples thereof include "ARON OXETANE OXT-101", "ARON OXETANE OXT-121", "ARON OXETANE OXT-211", and "ARON OXETANE OXT". -221", "ARON OXETANE OXT-212" (all of which are East Asian Synthetic Co., Ltd.).

The amount of the propylene oxide compound to be added is not particularly limited, and is usually preferably 30 parts by weight or less, and preferably 10 to 25 parts by weight, based on 100 parts by weight of the active energy ray-curable compound.

When the curable resin composition used in the present invention contains a cationic curable compound such as an epoxy compound or a propylene oxide compound, a photocationic polymerization initiator is preferably added to the curable resin composition. When a photocationic polymerization initiator is used, since a protective layer can be formed at normal temperature, it is considered that the heat resistance of the polarizing film or the necessity of skewing due to expansion is reduced, and a protective layer having good adhesion can be formed on the polarizing film. . At the same time, since the photocationic polymerization initiator is a photocatalytic action, even when it is mixed in the curable resin composition, its storage stability and workability are excellent.

The photocationic polymerization initiator starts the polymerization of an epoxy compound and/or a propylene oxide compound by irradiation with an active energy ray such as visible light, ultraviolet light, X-ray or electron beam to generate a cationic species or a Lewis acid. By. The photocationic polymerization initiator of any type may be used in the invention, and is not particularly limited, and examples thereof include an anthracene salt such as an aromatic diazonium salt, an aromatic iodonium salt, or an aromatic sulfonium salt; Allene is a salt or the like.

Examples of the aromatic diazonium salt include benzodiazepine hexafluoroantimonate, benzodiazepine hexafluorophosphate, and benzodiazepine hexafluoroborate.

Meanwhile, examples of the aromatic iodonium salt include diphenyl iodonium salt of pentium (pentafluorophenyl) borate, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroantimonate, and six A bis(4-mercaptophenyl) iodonium fluorophosphate salt or the like.

As the aromatic sulfonium salt, for example, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium sulfonate (pentafluorophenyl)borate, and bishexafluoride 4,4'-bis[diphenylthioindenyl]diphenyl sulfide salt, 4,4'-bis[bis(β-hydroxyethoxy)phenylthioindenyl]diphenyl bis(hexafluoroantimonate) Thioether salt, 4,4'-bis[bis(β-hydroxyethoxy)phenylsulfanyl]diphenyl sulfide salt of hexafluorophosphate, 7-[di(p-tolyl) hexafluoroantimonate Thiosulfonyl]-2-isopropylthioxanthone salt, ruthenium (pentafluorophenyl)borate 7-[bis(p-tolyl)sulfonium]-2-isopropylthioxanthone salt, hexafluorophosphoric acid 4-phenylcarbonyl-4'-diphenylsulfanyl-diphenyl sulfide salt, 4-(p-t-butylphenylcarbonyl)-4'-diphenylsulfanyl hexafluoroantimonate -diphenyl sulfide salt, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-tolyl)thiol-diphenyl sulfide salt of ruthenium (pentafluorophenyl)borate .

As the iron-propadiene salt, for example, xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, xylene - cyclopentadienyl iron (II) gin (trifluoromethylsulfonyl) methanide or the like.

Such a photo-cationic polymerization initiator can be easily obtained from commercially available products such as "KAYARAD PCI-220" and "KAYARAD PCI-620" (above, Nippon Kayaku Co., Ltd.) and "UVI", respectively. -6990" (made by Union Carbide), "ADEKA OPTOMER SP-150", "ADEKA OPTOMER SP-170" (above, ADEKA), "CI-5102", "CIT-1370", "CIT- 1682", "CIP-1866S", "CIP-2048S", "CIP-2064S" (above, Japan's Soda (share) system), "DPI-101", "DPI-102", "DPI-103", " DPI-105", "MPI-103", "MPI-105", "BBI-101", "BBI-102", "BBI-103", "BBI-105", "TPS-101", "TPS-" 102", "TPS-103", "TPS-105", "MDS-103", "MDS-105", "DTS-102", "DTS-103" (above, Midori Chemical Co., Ltd.), " PI-2074" (manufactured by Rhodia Co., Ltd.), "UVACURE 1590" (manufactured by DAICEL-CYTEC Co., Ltd.).

These photocationic polymerization initiators may be used singly or in combination with one or more other kinds. Among these, in particular, an aromatic sulfonium salt has ultraviolet absorbing properties in a wavelength region of 300 nm or more, and can provide excellent hardenability, good mechanical strength, or good adhesion to a polarizing film. Hardened, so it is more suitable.

The compounding amount of the photocationic polymerization initiator is usually 0.5 to 20 parts by weight, and preferably 1 to 6 parts by weight, based on 100 parts by weight of the total of the cationic hardening compound such as an epoxy compound or a propylene oxide compound. . When the compounding amount of the photocationic polymerization initiator is less than 0.5 part by weight based on 100 parts by weight of the total of the epoxy compound and the propylene oxide compound, the hardening is insufficient, and the mechanical strength or the protective layer and the polarized light are caused. The adhesion between the films tends to decrease. Meanwhile, when 100 parts by weight of the total amount of the cationic hardening compound, such as the photocationic polymerization initiator, is more than 20 parts by weight, the ionic substance in the hardened material may be increased to increase the moisture absorption of the cured product. Sex, which in turn reduces durability.

The curable resin composition used for forming the protective layer contains the above epoxy compound, or the above epoxy compound and propylene oxide compound, and is radically polymerizable and has at least one (meth) propylene oxide in the molecule. a (meth)acrylic compound. Since the (meth)acrylic compound is contained, a protective layer having high hardness, excellent mechanical strength, and high durability can be obtained. Further, since the (meth)acrylic compound is contained, the viscosity and the curing rate of the curable resin composition, the surface hardenability of the obtained protective layer, and the adhesion to the polarizing film can be more easily adjusted.

Further, the (meth)acrylic compound in the present invention can provide a hardened product formed of only a compound having the (meth)acrylonitrile group and a polymerization initiator, and can provide 3,000 MPa or more (3,100 MPa or more). Good) is better than the elastic modulus. When a (meth)acrylic compound having a modulus of elasticity of only 3,000 MPa which is formed of a compound having only the (meth)acrylinyl group and a polymerization initiator is used, the mechanical strength of the protective film is insufficient. It does not inhibit the shrinkage of the polarizing film.

Here, "(meth)acryloxy" means a methacryloxy group or an acryloxy group. "(Meth)acrylic compound having at least one (meth) acryloxy group" means having at least one methacryloxy group or acryloxy group in the molecule, respectively, which can be initiated at the photoradical polymerization. A methacrylate derivative or an acrylate derivative hardened by irradiation with an active energy ray (for example, ultraviolet light, visible light, electron beam, X-ray, etc.) in the presence of a solvent.

As the (meth)acrylic compound having at least one (meth) acryloxy group in the molecule, for example, a (meth) acrylate monomer having at least one (meth) acryloxy group in the molecule (hereinafter, a (meth) acrylate oligomer having at least two (meth) acryloxy groups in the molecule (hereinafter referred to as "(meth) acrylate monomer") A compound containing a (meth)acryloxy group, such as an ester oligomer. These compounds may be used singly or in combination of one or more kinds. The term "(meth)acrylate monomer" means an acrylate monomer or a methacrylate monomer, respectively, and "(meth)acrylate oligomer" means an acrylate oligomer or methacrylic acid. Ester oligomer.

The above (meth) acrylate monomer may, for example, be a (meth) acrylate monomer having one (meth) acryloxy group in the molecule (hereinafter, referred to as "monofunctional (meth) acrylate). a monomer ()), a (meth) acrylate monomer having two (meth) acryloxy groups in the molecule (hereinafter referred to as a difunctional (meth) acrylate monomer), and three or more molecules in the molecule A (meth) acryloxy (meth) acrylate monomer (hereinafter referred to as a polyfunctional (meth) acrylate monomer). The (meth) acrylate monomer may be used alone or in combination of two or more.

Specific examples of the monofunctional (meth) acrylate monomer include tetrahydrofuran methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate. Ester, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, isobutyl (methyl) ) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, benzo (meth) acrylate, isobornyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) acrylate, dimethylamino Ethyl (meth) acrylate, ethyl carbitol (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, phenoxy polyethylene glycol (Meth) acrylate, etc.

As the monofunctional (meth) acrylate monomer, a carboxyl group-containing (meth) acrylate monomer can also be used. As the monofunctional (meth) acrylate monomer having a carboxyl group, for example, 2-(meth) propylene methoxyethyl phthalic acid, 2-(meth) propylene methoxyethyl hexahydrophthalic acid, Carboxyethyl (meth) acrylate, 2-(methyl) propylene methoxyethyl succinic acid, N-(methyl) propylene decyloxy-N', N'-dicarboxy-p-phenylenediamine , 4-(meth)acryloyloxyethyl trimellitic acid, and the like. Further, as the monofunctional (meth) acrylate monomer, a (meth) acrylonitrile-based monomer such as 4-(meth) acrylamido-1-ylmethylmethylpiperidine or the like can be used.

As for the above difunctional (meth) acrylate monomer, although alkanediol di(meth)acrylates, polyoxyalkylene glycol di(meth)acrylates, halogen-substituted alkanediols II can be used ( Methyl) acrylates, di(meth) acrylates of aliphatic polyols, di(meth) acrylates of hydrogenated dicyclopentadiene or tricyclodecane dialkyl alcohol, Alkanediol or dioxane a di(meth) acrylate of an alkyl dialkanol, a di(meth) acrylate of an alkylene oxide adduct of bisphenol A or bisphenol F, an epoxy bisphenol A or an epoxide of bisphenol F Methyl) acrylates and the like are representative monomers, but are not limited thereto and various monomers can be used.

Specific examples of the difunctional (meth) acrylate monomer include ethylene glycol di(meth) acrylate, 1,3-butylene glycol di(meth) acrylate, and 1,4-butanediol II. (Meth) acrylate, 1,6-hexanediol di(meth) acrylate, 1,9-nonanediol di(meth) acrylate, neopentyl glycol di(meth) acrylate, three Hydroxymethylpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, di(trimethylolpropane)di(meth)acrylate, diethylene glycol di(meth)acrylate, three Ethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(methyl) Acrylate, polybutylene glycol di(meth)acrylate, polyoxydi(meth)acrylate, hydroxytrimethylacetate neopentyl glycol di(meth)acrylate, 2,2-double [4-(Methyl)acryloxyethoxyethoxyethoxyphenyl]propane, 2,2-bis[4-(methyl)propenyloxyethoxyethoxycyclohexyl]propane, hydrogenation Dicyclopentadienyl di(meth)acrylate, tricyclodecane dimethanol di(II) Acrylate, 1,3-two Alkane-2,5-diyldi(meth)acrylate [aka: two Alkanediol di(meth)acrylate], acetal compound of hydroxytrimethylacetaldehyde and trimethylolpropane [chemical name: 2-(2-hydroxy-1,1-dimethylethyl)- 5-ethyl-5-hydroxymethyl-1,3-di Di(meth) acrylate of alkane], di(meth) acrylate of 1,3,5- cis (2-hydroxyethyl) isocyanurate, and the like.

Examples of the trifunctional or higher (meth) acrylate monomer include tris(meth)acrylate, trimethylolpropane tri(meth)acrylate, and bis(trimethylolpropane)tris(methyl). Acrylate, bis(trimethylolpropane)tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol A poly(meth)acrylate of a trifunctional or higher aliphatic polyol such as (meth)acrylate or dipentaerythritol hexa(meth)acrylate, which is a monomer represented by a poly(meth)acrylate, and a trifunctional or higher halogen substitution. Poly(meth) acrylate of polyhydric alcohol, tri(meth) acrylate of alkylene oxide adduct of glycerol, tri(meth) acrylate of alkylene oxide adduct of trimethylolpropane, 1 , 1,1-para [(methyl)acryloxyethoxyethoxyethoxy]propane, 1,3,5-gin(2-hydroxyethyl)isocyanurate tri(meth)acrylate Classes, polyoxyhexa(hexa) (meth) acrylate, and the like.

As the above (meth) acrylate oligomer, for example, an amine ester (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, and an epoxy (meth) acrylate oligomer can be mentioned. Things and so on. The (meth) acrylate oligomer may be used alone or in combination of two or more.

The amine ester (meth) acrylate oligomer refers to a compound having an amine ester bond (-NHCOO-) and at least two (meth) acryloxy groups in the molecule. Specifically, it is a product obtained by subjecting a (meth) acrylate monomer having at least one (meth) acryloxy group and at least one hydroxyl group in the molecule to a transesterification reaction with a polyisocyanate, or a polyol and The polyisocyanate is reacted to obtain an amine ester compound containing a terminal isocyanate group, and an amine esterification reaction product with a (meth) acrylate monomer having at least one (meth) acryloxy group and at least one hydroxyl group in the molecule. .

As the hydroxyl group-containing (meth) acrylate monomer used in the amine esterification reaction, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- Hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerol di(meth) acrylate, trimethylolpropane di (meth) acrylate, Pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and the like.

The polyisocyanate used for the amine esterification reaction with such a hydroxyl group-containing (meth) acrylate monomer may, for example, be hexamethylene diisocyanate, diazonic acid diisocyanate, isophorone diisocyanate or bicyclo ring. Diisocyanate obtained by hydrogenating aromatic isocyanate in such diisocyanates (for example, hydrogenated diisocyanate), hexylmethane diisocyanate, toluene diisocyanate, terephthalic acid diisocyanate, hydrogenation of aromatic isocyanates in such diisocyanates, Diisocyanate such as hydrogenated diisocyanate (diphenylene diacetate), triphenylmethane triisocyanate, dimethylene triphenyl triisocyanate, diphenylmethylbenzene triisocyanate, etc., and more diisocyanate Quantitatively obtained polyisocyanate or the like.

Meanwhile, the polyol used in the case of forming an amine ester compound containing a terminal isocyanate group by reacting with a polyisocyanate, in addition to an aromatic, aliphatic and alicyclic polyol, may also be, for example, a polyester polyol. , polyether polyols, and the like. As the aliphatic and alicyclic polyol, for example, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol can be mentioned. , trimethylolethane, trimethylolpropane, bis(trimethylolpropane), pentaerythritol, dipentaerythritol, dimethylol heptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerol , hydrogenated bisphenol A and the like.

The polyester polyol is a product obtained by a condensation reaction of the above polyol with a polyvalent carboxylic acid or an anhydride thereof. Examples of the polyvalent carboxylic acid or an anhydride thereof include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), and pyromellitic acid ( Anhydride), hexahydrophthalic acid (anhydride), citric acid (anhydride), meta-citric acid, p-citric acid, and the like.

As the polyether polyol, in addition to the polyalkylene glycol, for example, the above polyhydric alcohol or a polyoxyalkylene-modified polyhydric alcohol obtained by reacting a dihydroxybenzene with an alkylene oxide can be mentioned.

The polyester (meth) acrylate oligomer refers to a compound having an ester bond and at least two (meth) acryloxy groups in the molecule. Specifically, it can be obtained by a condensation reaction of (meth)acrylic acid, a polyvalent carboxylic acid or an anhydride thereof, and a polyhydric alcohol. Examples of the polyvalent carboxylic acid or its anhydride used in the condensation reaction include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), and trimellitic acid (anhydride). And pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), citric acid (anhydride), meta-citric acid, p-citric acid and the like. Meanwhile, as the polyol used in the condensation reaction, for example, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and neopenta-2 may be mentioned. Alcohol, trimethylolethane, trimethylolpropane, bis(trimethylolpropane), pentaerythritol, dipentaerythritol, dimethylol heptane, dimethylolpropionic acid, dimethylolbutanoic acid, Glycerin, hydrogenated bisphenol A, and the like.

The epoxy (meth) acrylate oligomer can be obtained by an addition reaction of a polydehydrated ether with (meth)acrylic acid having at least two (meth) acryloxy groups in the molecule. As the polydehydrated ether used in the addition reaction, for example, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol di-dehydrated water Glycerol ether, bisphenol A diglycidyl ether, and the like.

Among the (meth)acrylic compounds of the present invention, in particular, in terms of excellent adhesion and modulus of elasticity, (meth)acrylic acid represented by using at least one of the following formulas (1) to (4) is used. Class compounds are preferred.

In the above formulae (1) and (2), Q ₁ and Q ₂ each independently represent a (meth)acryloxy group or a (meth)acryloxyalkyl group. When Q ₁ or Q ₂ is a (meth) acryloxyalkyl group, the alkyl group may be a straight chain or a branch having a carbon number of 1 to 10, usually at a carbon number of about 1 to 6. . Meanwhile, in the formula (2), R is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and the hydrocarbon group may be a straight chain or a branched group, and a typical group is an alkyl group. The alkyl group at this time is also usually at a carbon number of about 1 to 6. Further, in the formula (3), T ₁ , T ₂ and T ₃ each independently represent a (meth)acryloxy group, and in the formula (4), T represents a hydroxyl group or a (meth)acryloxy group.

The compound represented by the formula (1) is a di(meth) acrylate derivative of hydrogenated dicyclopentadiene or tricyclodecane dialkyl alcohol, and specific examples thereof have been exemplified above, including hydrogenated dicyclopentadienyl group II. (meth) acrylate [in the formula (1), Q ₁ = Q ₂ = (meth) propylene oxime compound], tricyclodecane dialkyl alcohol di (meth) acrylate [formula (1) In the formula, Q ₁ = Q ₂ = a compound of (meth) propylene methoxymethyl group].

The compound represented by the formula (2) is two Alkylene glycol or two A di(meth) acrylate derivative of an alkyldialkanol, the specific examples of which have been exemplified before, including 1,3-two Alkane-2,5-diyldi(meth)acrylate [aka: two Alkanediol di(meth)acrylate, in formula (2), Q ₁ =Q ₂ =(methyl)propenyloxy, compound of R=H], hydroxytrimethylacetaldehyde and trimethylol Acetal compound of propane [chemical name: 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-di Di(meth) acrylate of alkane] [in the formula (2), Q ₁ = (meth) propylene methoxymethyl group, Q ₂ = 2-(methyl) propylene decyloxy-1, 1-di a methyl ethyl group, a compound of R = ethyl group, and the like.

The compound represented by the formula (3) has been exemplified previously, and it is a triacrylate or trimethacrylate of 1,3,5-gin(2-hydroxyethyl)-isocyanurate.

Meanwhile, the compound represented by the formula (4) is a tris or tetra(meth)acrylate of pentaerythritol, and specific examples thereof have been exemplified above, including pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate.

In the curable resin composition used in the present invention, the (meth)acrylic compound is preferably 10 to 70 parts by weight, and preferably 20 to 65 parts by weight, based on 100 parts by weight of the active energy ray-curable compound. It is particularly preferred when it is 30 to 60 parts by weight. When the content of the (meth)acrylic compound is less than 10 parts by weight, the shrinkage ratio of the polarizing plate may increase. Meanwhile, when the content of the (meth)acrylic compound exceeds 70 parts by weight, the adhesion between the polarizing plate and the protective layer may be insufficient.

When the curable resin composition contains a radically polymerizable compound such as the above (meth)acrylic compound, it is preferred to use a photoradical polymerization initiator. As for the photoradical polymerization initiator, a radical polymerization compound such as a (meth)acrylic compound can be polymerized by irradiation with an active energy ray, and a conventionally known polymerization initiator can be used. . Specific examples of the photoradical polymerization initiator include, for example, acetophenone, 3-methylacetophenone, benzyldimethylketal, 1-(4-isopropylphenyl)-2-hydroxy- 2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl-2-morpholinylpropan-1-one, 2-hydroxy-2-methyl-1 -Phenylpropan-1-one acetophenone initiator; benzophenone from benzophenone, 4-chlorobenzophenone, 4,4'-diaminobenzophenone Starting agent; benzoin ether starter such as benzoin isopropyl ether, benzoin ethyl ether; thioxanthone starter such as 4-isopropyl thioxanthone; others such as xanthone, fluorenone, camphorquinone ), benzaldehyde, hydrazine, etc.

The compounding amount of the photoradical polymerization initiator is usually from 0.5 to 20 parts by weight, and preferably from 1 to 6 parts by weight, based on 100 parts by weight of the radically polymerizable compound such as a (meth)acrylic compound. When the amount of the photoradical polymerization initiator is less than 0.5 part by weight based on 100 parts by weight of the radical polymerizable compound, the hardening is insufficient, and it is possible to cause mechanical strength or between the protective layer and the polarizing film. The adhesion is reduced. Meanwhile, when the amount of the photoradical polymerization initiator is more than 20 parts by weight based on 100 parts by weight of the (meth)acrylic compound, the durability of the obtained polarizing plate may be lowered.

The curable resin composition used in the present invention may further contain fine particles. The hardenable resin composition will further increase the hardness and mechanical strength of the resulting protective layer by containing fine particles. Therefore, the ability to suppress the shrinkage of the polarizing film under high temperature and high humidity can be further improved. Examples of the fine particles include inorganic fine particles, organic fine particles, and inorganic/organic mixed fine particles. Since the protective layer is preferably optically transparent, the fine particles used are preferably those which do not cause light scattering or the like and which do not impair the optical transparency of the protective layer.

The inorganic fine particles are not particularly limited, and examples thereof include metal oxide fine particles such as cerium oxide fine particles, alumina fine particles, tin oxide fine particles, cerium oxide fine particles, and indium oxide fine particles; tin oxide-cerium composite oxide fine particles and indium oxide-tin composite oxidation. Composite oxide fine particles such as fine particles. Among them, the ruthenium oxide microparticles are suitable because of the low refractive index of the material itself and the high strength. The cerium oxide microparticles may also have a hydroxyl group on their surface. Meanwhile, examples of the organic fine particles include fine particles formed of a polystyrene resin, an acrylic resin, an organic polyoxyn resin, a polycarbonate resin, or the like. Meanwhile, examples of the inorganic/organic hybrid fine particles include cerium oxide fine particles having a functional group such as an epoxy group, a (meth) acryloxy group, or a vinyl group. From the viewpoint of crosslinking by reaction with an active energy ray-curable compound, cerium oxide fine particles having a reactive functional group such as a hydroxyl group, an epoxy group or a (meth) acryloxy group on the surface are preferably used.

The particle diameter of the fine particles measured by the BET method or the dynamic light scattering method (DLS method) is preferably 100 nm or less, and more preferably 70 nm or less. When the particle diameter of the fine particles exceeds 100 nm, there is a tendency that an optically transparent protective layer cannot be obtained. Further, the particle diameter is usually 3 nm or more.

The inorganic fine particles may be added to the curable resin composition as solid fine particles, or may be added after being dispersed in a solvent to form a gel. As for the solvent, since drying is relatively easy, it is preferred to use an organic solvent. As the inorganic fine particles which have been dispersed in the organic solvent to which the present invention is applied, for example, colloidal silica can be mentioned. The concentration of cerium oxide in the cerium oxide colloid is not particularly limited, and for example, about 20 to 40% by weight of a cerium oxide colloid commercially available from a commercially available product can be used. The cerium oxide colloid may be used singly or in combination of two or more.

As for the cerium oxide colloid which is commercially available, for example, "Methanol Silica Sol" (manufactured by Nissan Chemical Industries Co., Ltd., having a cerium oxide particle diameter of 10 to 15 nm and a solid content of 30% by weight), " MA-ST-M" (manufactured by Nissan Chemical Industries Co., Ltd., cerium oxide particle size 20 to 25 nm, solid content 40% by weight), "OSCAL 1132" (catalyzed into chemical industry), cerium oxide particle size 10 to 20 nm, 30 to 31% by weight of solid content; "OSCAL 1232" (manufactured by Catalyst Chemical Co., Ltd., cerium oxide particle size 10 to 20 nm, solid content 30 to 31% by weight); "OSCAL 1332" of n-propanol (manufactured by Catalyst Chemical Co., Ltd., cerium oxide particle size 10 to 20 nm, solid content 30 to 31% by weight); organic solvent is isopropyl alcohol "IPA-ST" (Nissan Chemical Co., Ltd.) Industrial (stock) system, cerium oxide particle size 10 to 15 nm, solid content 30% by weight), "OSCAL 1432" (catalyzed into a chemical industry), cerium oxide particle size 10 to 20 nm, solid content 30 to 31% by weight ); the organic solvent is n-butanol "NBA-ST" (manufactured by Nissan Chemical Industries Co., Ltd., cerium oxide particle size 10 to 15 nm, solid content 20% by weight), "OSCAL 1532" (catalyst formation) (Stock), cerium oxide particle size 10 to 20 nm, solid content 30 to 31% by weight); organic solvent is ethylene glycol "EG-ST" (manufactured by Nissan Chemical Industry Co., Ltd., cerium oxide particle size 10 to 15 nm , the solid content is 20% by weight); the organic solvent is "OSCAL 1632" (manufactured by Catalyst Chemical Co., Ltd., cerium oxide particle size 10 to 20 nm, solid content 30 to 31% by weight); organic solvent "NPC-ST" of ethylene glycol mono-n-propyl ether (manufactured by Nissan Chemical Industries Co., Ltd., cerium oxide particle size 10 to 15 nm, solid content 30% by weight); organic solvent is dimethylacetamide "DMAC" -ST" (manufactured by Nissan Chemical Industries Co., Ltd., cerium oxide particle size 10 to 15 nm, solid content 20% by weight), "DMAC-ST-ZL" (manufactured by Nissan Chemical Industry Co., Ltd., cerium oxide particle size 70 to 100 nm) , solid content 20% by weight); organic solvent is a mixture of xylene and n-butanol "XBA-ST" (manufactured by Nissan Chemical Industry Co., Ltd., cerium oxide particle size 10 to 15 nm, solid content 30% by weight); organic The solvent is methyl isobutyl ketone "MIBK-ST" (manufactured by Nissan Chemical Industries Co., Ltd., cerium oxide particle size 10 to 15 nm, solid content 30% by weight), and the organic solvent is methyl ethyl ketone "MEK- ST" (Nissan Chemical Industry (stock) system, cerium oxide particle size 10 to 15nm, solid content 30% by weight), "SP-1120" (made by Xiaoxi Chemical Industry Co., Ltd., cerium oxide particle size 15 to 20nm, solid content 5 to 10% by weight ), "SP-6120" (manufactured by Xiaoxi Chemical Industry Co., Ltd., cerium oxide particle size 15 to 20 nm, solid content 5 to 10% by weight); "SNOWTEX 20" with dispersant water (Nissan Chemical Industry Co., Ltd.) The cerium oxide colloid may be used alone or in combination of two or more kinds, such as "SNOWTEX C" (manufactured by Nissan Chemical Industries Co., Ltd., having a cerium oxide particle size of 10 to 20 nm).

In the case of the commercially available product of the solid cerium oxide microparticles, for example, "AEROSIL 50", "AEROSIL 130" and other "AEROSIL" series of Japanese AEROSIL (shares), "Nipsil E 150K", "Nipsil" Such products may also be used for the sale of Japanese niobium oxide products (shares) of the "Nipsil" series such as E 200".

The microparticles are preferably added in an amount of 5 to 250 parts by weight, and more preferably 10 to 100 parts by weight, based on 100 parts by weight of the active energy ray-curable compound contained in the curable resin composition. When the amount of the fine particles added is less than 5 parts by weight based on 100 parts by weight of the active energy ray-curable compound, the hardness of the protective layer may not be sufficiently increased by the addition of fine particles. On the other hand, when the amount of fine particles added exceeds 250 parts by weight based on 100 parts by weight of the active energy ray-curable compound, the adhesion between the polarizing film and the protective layer may be lowered. Meanwhile, when the amount of the fine particles added is more than 250 parts by weight, the dispersion stability of the fine particles in the curable resin composition may be lowered or the viscosity of the curable resin composition may be excessively increased.

The curable resin composition may further contain a photosensitizer as needed. By using a photosensitizer, the reactivity of cationic polymerization and/or radical polymerization of the active energy ray-curable compound can be improved, and the mechanical strength of the protective layer and the adhesion between the protective layer and the polarizing film can be improved. The photosensitizer may, for example, be a carbonyl compound, an organic sulfur compound, a persulfide compound, a redox compound, an azo or a diazo compound, a halide or a photoreductive dye. As the specific photosensitizer, for example, benzoin methyl ether, benzoin isopropyl ether, benzoin derivatives such as α,α-dimethoxy-α-phenylacetamidine; benzophenone, 2,4-di Chlorobenzophenone, methyl phthalic acid benzoate, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone a benzophenone derivative such as a benzophenone derivative; 2-chlorothioxanthone or 2-isopropylthioxanthone; an anthracene derivative such as 2-chloroindole or 2-methylindole; Acridinone derivatives such as methyl acridone and N-butylacridone; others such as α,α-diethoxyethyl benzene, benzil, anthrone, xanthone, uranium Uranyl compounds, halides, and the like. These photosensitizers may be used singly or in combination with one or more other kinds. The photosensitizer is preferably contained in an amount of from 0.1 to 20 parts by weight based on 100 parts by weight of the active energy ray-curable compound.

Meanwhile, the curable resin composition may also contain an antistatic agent for imparting antistatic properties to the polarizing plate. The antistatic agent is not particularly limited, and a well-known antistatic agent can be used. For example, acyloyl amide propyl dimethyl hydroxy ethyl ammonium nitrate, decyl guanidinopropyl trimethyl ammonium sulfate, cetyl morpholinium methyl sulfate ( a cationic surfactant such as cetylmorpholiummethosulfate; an anionic surfactant such as a linear alkyl potassium phosphate, a polyoxyalkylethyl potassium phosphate or an alkanesulfonate; N,N-bis(hydroxyethyl)- A nonionic surfactant such as an N-alkylamine, a fatty acid ester derivative or a polyol fatty acid partial ester. The compounding ratio of these antistatic agents is appropriately determined depending on the desired properties, but is usually about 0.1 to 20 parts by weight based on 100 parts by weight of the active energy ray-curable compound.

A known polymer additive which is usually used in a polymer material may be added to the curable resin composition. For example, primary antioxidants such as phenols or amines; secondary antioxidants for sulfur; hindered amine light stabilizers (HALS); ultraviolet absorption of benzophenones, benzotriazoles, benzoates, etc. Agents, etc.

Meanwhile, the curable resin composition may contain a leveling agent as needed. When the curable resin composition is coated on a polarizing film or a substrate, the case where the polarizing film or the substrate lacks wettability or the cured surface of the curable resin composition is not good, These effects can be improved after the dye is applied. Various compounds such as polyfluorene, fluorine, polyether, acrylic copolymer, and titanate can be used as the leveling agent. These leveling agents may be used singly or in combination of two or more.

The leveling agent is preferably added in an amount of 0.01 to 1 part by weight, and preferably 0.1 to 0.7 part by weight, and preferably 0.2 to 0.5 part by weight, based on 100 parts by weight of the active energy ray-curable compound contained in the curable resin composition. Better. When the amount of the leveling agent added is less than 0.01 part by weight based on 100 parts by weight of the active energy ray-curable compound, there is a possibility that the improvement in wettability and surface properties is insufficient. Meanwhile, when the amount of the leveling agent added exceeds 1 part by weight based on 100 parts by weight of the active energy ray-curable compound, the adhesion between the polarizing film and the protective layer may be lowered.

Further, the curable resin composition may contain a solvent as needed. The solvent is appropriately selected depending on the solubility of the components constituting the curable resin composition. The solvent to be generally used may, for example, be an aliphatic hydrocarbon such as n-hexane or cyclohexane; an aromatic hydrocarbon such as toluene or xylene; or an alcohol such as methanol, ethanol, propanol, isopropanol or n-butanol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ceramides such as methyl acetate, ethyl acetate, and acetic acid; halogenated hydrocarbons such as vinyl chloride or chloroform. The ratio of the solvent is appropriately determined in view of the processability such as film formability and the viscosity of the active energy ray-curable resin composition required.

As a method of forming the above protective layer on one side or both sides of the polarizing film, the following method can be mentioned. First, the curable resin composition is applied onto a substrate such as a polyethylene terephthalate film (PET film). Then, if necessary, drying is performed to remove the solvent, and the substrate having the coating film formed of the curable resin composition is bonded to the polarizing film so that the coating film side is the bonding surface. At this time, if the protective layer is to be laminated on both surfaces of the polarizing film, two substrates having a coating film are formed, and then the two substrates are bonded to both surfaces of the polarizing film. Next, after irradiation or heating of an active energy ray such as visible light, ultraviolet light, X-ray, or electron beam, the coating film formed of the curable resin composition is cured, and a protective layer is formed on the laminated body. Finally, after the substrate is peeled off, a polarizing plate having a protective layer on one or both sides of the polarizing film can be obtained. When considering the thinness and lightness, the thickness of the protective layer is as thin as possible, but if it is too thin, the polarizing film cannot be sufficiently protected, and at the same time, work handling property is also lacking. Therefore, the thickness of the protective layer is preferably about 1 to 35 μm.

Although the protective layer may be formed by hardening after directly applying the curable resin composition to the polarizing film, if the curable resin composition contains a solvent and is subjected to a drying step to harden it, the polarizing film is prevented from being solvent-treated. The viewpoint of erosion or shrinkage at a drying temperature is preferably the above method. Meanwhile, when a protective layer is to be formed on both surfaces of the polarizing film, the components contained in the curable resin composition for forming the two protective layers may be the same or different.

When hardening by irradiation with an active energy ray, although the light source used is not particularly limited, a light source having a light-emitting distribution at a wavelength of 400 nm or less, such as a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, can be used. , black light, microwave excited mercury lamp, metal halide lamp, etc. The illuminating intensity of the curable resin composition may vary depending on the composition, but the irradiation intensity in the wavelength range effective for activation of the photoradical polymerization initiator and/or photocationic polymerization initiator is 10 It is preferably at 2,500 mW/cm ² . When the illuminating intensity of the curable resin composition is less than 10 mW/cm ² , the reaction time is too long, and if it exceeds 2,500 mW/cm ² , the radiant heat from the lamp and the heat generation during the polymerization of the curable resin composition are caused. It may cause yellowing of the curable resin composition or deterioration of the polarizing film. The illuminating time of the curable resin composition is controlled according to the composition, and is not particularly limited, and is set so that the cumulative light represented by the product of the irradiation intensity and the irradiation time is 10 to 2,500 mJ/cm ^{2 .} Time is better. If the cumulative brightness of the curable resin composition is less than 10 mJ/cm ² , the production of the active species derived from the polymerization initiator will be insufficient, and the hardening of the resulting protective layer may be insufficient. At the same time, if the cumulative brightness exceeds 2,500 mJ/cm ² , the irradiation time will become very long, which is unfavorable for improving the yield. Further, it is preferable that the irradiation of the active energy ray is performed within a range that does not lower various properties such as the degree of polarization of the polarizing film and the transmittance.

<Optical components and liquid crystal display devices>

The optical module of the present invention is composed of a laminate of the above polarizing plate and an optical functional layer, and specifically has a structure in which an optical functional layer is provided on a protective layer of the polarizing plate. The optical functional layer is not particularly limited, and a well-known optical functional layer can be used. Specific examples of the optical function layer include a reflective layer, a semi-transmissive reflective layer, a light diffusion layer, a phase difference plate, a concentrating plate, a brightness enhancement film, and the like.

The reflective layer can be formed, for example, by providing a metal foil or a vapor deposited film made of a metal such as aluminum on a protective layer of a polarizing plate. The semi-transmissive reflective layer is formed by applying a reflective layer as a half mirror and providing a reflective plate containing a light-transmitting property such as pearl pigment on the protective layer. The light-diffusing layer is formed on the protective layer by a method of performing a mat treatment, a method of applying a resin containing fine particles, a method of subsequently providing a film containing fine particles, and the like.

The purpose of using the phase difference plate is to compensate for the phase difference from the liquid crystal cell, and for example, a birefringent film formed of a stretch film of various plastics or the like, a discotic liquid crystal or a nematic type (directionally fixed) Nematic) a film of a liquid crystal, or a liquid crystal layer formed on the film substrate. At this time, a cellulose-based film such as triacetyl cellulose is preferably used as the film substrate supporting the alignment liquid crystal layer.

The purpose of using the concentrating sheet is to control an optical path or the like, which can be formed as a prism array sheet or a lens array sheet, or a dot-attached sheet.

The purpose of use of the brightness enhancement film is to increase the brightness of a liquid crystal display device or the like, and examples thereof include a film formed by laminating a plurality of films having different anisotropy in refractive index, and a reflection type having an anisotropy in reflectance. A polarizing separation plate, a circularly polarizing separator obtained by supporting an oriented film of a cholesteric liquid crystal polymer or an oriented liquid crystal layer thereof on a film substrate.

The above optical functional layers may be used singly or in combination of two or more. When the optical functional layer is bonded to the protective layer, if the protective layer has an adhesive force to the optical functional layer, the two may be directly bonded together or may be bonded using an adhesive or an adhesive. When the optical functional layers are bonded to each other, an adhesive or an adhesive may also be used.

As a method of directly bonding the protective layer to the optical functional layer, the active energy ray-curable resin composition is applied to one side of the optical functional layer, and after the coating film is formed on the phase difference plate, the coating film is applied as a sticker. A method of bonding a phase difference plate to a polarizing film and then hardening the coating film by irradiation with an active energy ray. According to such a production method, a polarizing film in which a polarizing film, a protective layer, and a phase difference plate are directly bonded without interposing another layer (for example, an adhesive layer or an adhesive layer) can be obtained.

Meanwhile, the optical functional layer can be directly used in the production of the optical component related to the present invention, or the corona discharge treatment or the plasma treatment can be performed on the bonding surface with the coating film forming the protective layer.

The polarizing plate or optical component of the present invention can be applied to a liquid crystal display device. At this time, the polarizing plate or the optical component of the present invention is disposed on one side or both sides of the liquid crystal cell. The polarizing plates or optical components disposed on both sides of the liquid crystal cell may be the same or different.

(Example)

Hereinafter, the invention will be more specifically described by way of examples, but the invention is not limited to the examples. In the examples, "parts" and "%" indicating the amount or content of use are based on weight unless otherwise specified.

(Manufacturing Example 1: Production of polarizing film)

A polyvinyl alcohol film having an average polymerization degree of about 2,400, a degree of saponification of 99.9 mol% or more and a thickness of 75 μm was immersed in pure water at 30 ° C, and then immersed in an iodine/potassium iodide/water weight ratio of 0.02 / at 30 ° C. 2/100 in an aqueous solution. Then, it was further immersed in an aqueous solution of potassium iodide/boric acid/water in a weight ratio of 12/5/100 at 56.5 °C. Subsequently, after washing with pure water of 8 ° C, it was dried at 65 ° C to obtain a polarizing film (thickness: 30 μm) in which iodine had been adsorbed and oriented in polyvinyl alcohol. The extension is mainly carried out in the steps of iodine dyeing and boric acid treatment, and the full stretching ratio is 5.3 times.

(Production Example 2: Preparation of Curable Resin Composition I)

The following components were mixed to obtain a curable resin composition I.

‧3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Co., Ltd., CELLOXIDE 2021P): 35 parts

‧Bis(3-ethyl-3-epoxypropylmethyl)ether (AYO OXETANE OXT-221): 15 parts

‧ Tricyclodecane dimethanol diacrylate (Xinzhongcun Chemical Industry Co., Ltd., A-DCP): 50 parts

‧2-Hydroxy-2-methyl-1-phenylpropan-1-one (Ciba Specialty Chemicals, manufactured by Ciba Specialty Chemicals, DAROCUR 1173: Photoradical Polymerization Initiator): 2.5 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide hexafluorophosphate-based photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMERSP-150): 2.5 parts

‧Polyoxygen leveling agent (Toray Dow Corning), SH710): 0.2 parts

Further, the above A-DOG (diacrylate of acetal trimethylacetaldehyde and trimethylolpropane acetal compound) is a compound having the following formula.

(Production Example 3: Preparation of Curable Resin Composition II)

The following components were mixed to obtain a curable resin composition II.

‧3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Co., Ltd., CELLOXIDE 2021P): 35 parts

‧Bis(3-ethyl-3-epoxypropylmethyl)ether (AYO OXETANE OXT-221): 15 parts

‧ Diacrylate of acetal compound of hydroxytrimethylacetaldehyde and trimethylolpropane (manufactured by Shin-Nakamura Chemical Co., Ltd., A-DOG): 50 parts

‧2-Hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Ciba Specialty Chemicals, DAROCUR 1173: Photoradical polymerization initiator): 2.5 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 2.5 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

(Production Example 4: Preparation of Curable Resin Composition III)

The following components were mixed to obtain a curable resin composition III.

‧3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Co., Ltd., CELLOXIDE 2021P): 35 parts

‧Bis(3-ethyl-3-epoxypropylmethyl)ether (AYO OXETANE OXT-221): 15 parts

‧1,3,5-tris(2-hydroxyethyl)isocyanurate triacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-9300): 50 parts

‧2-Hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Ciba Specialty Chemicals, DAROCUR 1173: Photoradical polymerization initiator): 2.5 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 2.5 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

(Production Example 5: Preparation of Curable Resin Composition IV)

The following components were mixed to obtain a curable resin composition IV.

‧3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Co., Ltd., CELLOXIDE 2021P): 35 parts

‧Bis(3-ethyl-3-epoxypropylmethyl)ether (AYO OXETANE OXT-221): 15 parts

‧ Pentaerythritol tetraacrylate (Xinzhongcun Chemical Industry Co., Ltd., A-TMMT): 50 parts

‧2-Hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Ciba Specialty Chemicals, DAROCUR 1173: Photoradical polymerization initiator): 2.5 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 2.5 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

(Production Example 6: Preparation of Curable Resin Composition V)

73 parts of the curable resin composition I and 30 parts (in terms of solid content) cerium oxide colloid (manufactured by Nissan Chemical Co., Ltd., MEK-ST, cerium oxide particle diameter: 10 to 15 nm) were mixed to obtain a curable resin composition. V.

(Production Example 7: Preparation of Curable Resin Composition VI)

73 parts of the curable resin composition II and 30 parts (in terms of solid content) of cerium oxide colloid (manufactured by Nissan Chemical Co., Ltd., MEK-ST, cerium oxide particle diameter: 10 to 15 nm) were mixed to obtain a curable resin composition. VI.

(Production Example 8: Preparation of Curable Resin Composition VII)

The following components were mixed to obtain a curable resin composition VII.

‧3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Co., Ltd., CELLOXIDE 2021P): 15 parts

‧3-ethyl-3-hydroxymethyl propylene oxide (AYO OXETANE OXT-101): 15 parts

‧ Ethylene oxide modified diacrylate of bisphenol A (Aronix M-210, manufactured by East Asia Synthetic Co., Ltd.): 49 parts

‧ Trimethylolpropane triacrylate (Xinzhongcun Chemical Industry Co., Ltd., TMPTA): 21 copies

‧2-Hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Ciba Specialty Chemicals, DAROCUR 1173: Photoradical polymerization initiator): 3 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 2 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

(Production Example 9: Preparation of Curable Resin Composition VIII)

The following components were mixed to obtain a curable resin composition VIII.

‧D-dehydroglyceryl ether of nuclear hydrogenated bisphenol A (made by Japan Epoxy Resin Co., Ltd., EPICOAT YX8000): 100 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 40 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

(Production Example 10: Preparation of Curable Resin Composition IX)

The following components were mixed to obtain a curable resin composition IX.

‧D-dehydroglyceryl ether of nuclear hydrogenated bisphenol A (made by Nippon Epoxy Resin Co., Ltd., EPICOAT YX8000): 70 parts

‧ 1,4-bis[{(3-ethyl-3-epoxypropyl)methoxy}methyl]benzene (AYO OXETANE OXT-121): 30 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 40 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

(Production Example 11: Preparation of Curable Resin Composition X)

The following components were mixed to obtain a curable resin composition X.

‧3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Co., Ltd., CELLOXIDE 2021P): 35 parts

‧Bis(3-ethyl-3-epoxypropylmethyl)ether (AYO OXETANE OXT-221): 15 parts

‧2-Hydroxy-3-phenoxypropyl acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 702A): 50 parts

‧2-Hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Ciba Specialty Chemicals, DAROCUR 1173: Photoradical polymerization initiator): 2.5 parts

‧4,4'-bis[diphenylthioindenyl]diphenyl sulfide Di-hexafluorophosphate photocationic polymerization initiator (made by ADEKA, ADEKA OPTOMER SP-150): 2.5 parts

‧ Polyoxane leveling agent (made by Toray Dow Corning, SH710): 0.2 parts

<Example 1>

The curable resin composition I obtained in Production Example 2 was applied onto a polyethylene terephthalate (PET) film (ESTER FILM E7002, manufactured by Toyobo Co., Ltd.) using a bar coater. Next, a PET film in which two coating films formed of a curable resin composition were formed by using a bonding apparatus (manufactured by FUJIPLA Co., Ltd., LPA3301) was attached to the coating film side as a bonding surface. Both surfaces of the polarizing film obtained in Example 1 were produced. Then, the laminated body was irradiated with ultraviolet light at a cumulative light amount of 1,500 mJ/cm ² by D Valve manufactured by Fusion UV Systems, and the coating films on both sides were cured. Finally, the PET film on both sides was peeled off, and a polarizing plate having a protective layer on both surfaces of the polarizing film was obtained.

<Examples 2 to 6, Comparative Examples 1 to 4>

A polarizing plate was produced in the same manner as in Example 1 except that the curable resin composition shown in Table 1 to be described later was used instead of the curable resin composition I.

<Example 7>

The curable resin composition V obtained in Production Example 6 was applied onto a polyethylene terephthalate (PET) film (ESTERFILM E7002, manufactured by Toyobo Co., Ltd.) using a bar coater. Next, it was dried at 80 ° C for 3 minutes to remove the solvent. Next, a PET film in which two coating films formed of a curable resin composition were formed by using a bonding apparatus (manufactured by FUJIPLA Co., Ltd., LPA3301) was attached to the coating film side as a bonding surface. Both sides of the polarizing film obtained in Example 1 were produced. Then, the laminate was irradiated with ultraviolet light at a cumulative light amount of 1,500 mJ/cm ² by D Valve manufactured by Fusion UV Systems, and the coating films on both surfaces were cured. Finally, the PET film on both sides was peeled off, and a polarizing plate having a protective layer on both surfaces of the polarizing film was obtained.

<Example 8>

The curable resin composition VI obtained in Production Example 7 was applied onto a polyethylene terephthalate (PET) film (ESTER FILM E7002, manufactured by Toyobo Co., Ltd.) using a bar coater. Next, it was dried at 80 ° C for 3 minutes to remove the solvent. Next, a PET film in which two coating films formed of a curable resin composition were formed by using a bonding apparatus (manufactured by FUJIPLA Co., Ltd., LPA3301) was attached to the coating film side as a bonding surface. Both sides of the polarizing film obtained in Example 1 were produced. Then, the laminate was irradiated with ultraviolet light at a cumulative light amount of 1,500 mJ/cm ² by D Valve manufactured by Fusion UV Systems, and the coating films on both surfaces were cured. Finally, the PET film on both sides was peeled off, and a polarizing plate having a protective layer on both surfaces of the polarizing film was obtained.

<Comparative Example 5>

A polarizing plate (TRW842A, manufactured by Sumitomo Chemical Co., Ltd.) having a protective film having a thickness of 80 μm formed of triacetyl cellulose was attached to both surfaces of a polarizing film of a polyvinyl alcohol film having a directional iodine adsorbed thereon as Comparative Example 5 .

As shown in Table 1, the compositions of the compositions used in Examples 1 to 8 and Comparative Examples 1 to 5, respectively, the modulus of elasticity when the compositions were hardened, and the (meth)acrylic acid compounded therein only The elastic modulus of the cured product formed by the compound and the radical polymerization initiator (abbreviated as "acrylic acid" in the column of "elasticity" in the table) and the storage modulus of the cured product of each composition at 80 °C. The elastic modulus and storage elastic modulus can be obtained as follows, respectively.

[Method for measuring elastic modulus]

The curable resin composition for forming a protective layer was coated on a polyethylene terephthalate (PET) film (ESTER FILM E7002, Toyobo Co., Ltd.) using a coater (manufactured by Physicochemical Co., Ltd., Bar Coater). The single surface of the system was irradiated with ultraviolet light at a cumulative light amount of 1,500 mJ/cm ² by D Valve manufactured by Fusion UV Systems Co., Ltd. to cure the curable resin composition. Next, the cured product was cut into a 1 cm wide by 8 cm length together with a PET film, and a sample was obtained after peeling off the PET film. Then, the upper and lower jaws of the AUTOGRAPH AG-1S tester manufactured by Shimadzu Corporation were clamped at a temperature of 23 ° C and 55% RH, and the long side portion of the sample was sandwiched at a clamping gap of 5 cm. In a temperature of 23 ° C and a relative humidity of 55%, the tensile strength is 10 mm/min (the longitudinal direction of the sample is the stretching direction), and the data processing software (TRAPEZIUM 2, manufactured by Shimadzu Corporation) is used. The elastic modulus was calculated from the initial straight line of the obtained stress-strain curve. At the same time, the cured product composed of only the (meth)acrylic compound and the radical polymerization initiator used in each of the curable resin compositions was measured in the same manner.

[Method for Measuring Elasticity at 80 ° C]

Similarly to the above, each of the curable resin compositions was applied onto a PET film, and then cured by irradiation with ultraviolet rays. Subsequently, the film was cut into 5 mm × 30 mm, and the PET film was peeled off to obtain a single cured film of each curable resin composition. The DVA-220 manufactured by IT Measurement Control Co., Ltd. was used, and the obtained single film was sandwiched so that the long side was the stretching direction, and the jaw interval was set to 2 cm, the frequency was 1 Hz, and the temperature rising rate was 3 ° C/min. Storage modulus of °C.

In Table 1, an epoxy-based cationically polymerizable compound, a propylene oxide-based cationically polymerizable compound, a radically polymerizable compound, a cationic polymerization initiator, and a radical polymerization initiator are used as described above. The product name and abbreviation are indicated in each item by the symbol shown on the left side of the colon. The same applies to the product name and the abbreviation, and all the symbols in Table 1 are described below.

[Epoxy-based cationically polymerizable compound]

‧CEL 2021P: CELLOXIDE 2021P manufactured by Daicel Chemical Co., Ltd., chemical name 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate.

‧YX8000: EPICOAT YX8000 made by Japan Epoxy Resin Co., Ltd., chemically called dihydroglycidyl ether of nuclear hydrogenated bisphenol A.

[Phenylene oxide-based cationically polymerizable compound]

‧ OXT-221: ARON OXETANE OXT-221, manufactured by East Asia Synthetic Co., Ltd., chemically named bis(3-ethyl-3-epoxypropylmethyl)ether.

‧ OXT-101: ARON OXETANE OXT-101, manufactured by East Asia Synthetic Co., Ltd., chemically named 3-ethyl-3-hydroxymethyl propylene oxide.

‧ OXT-121: ARON OXETANE OXT-121, manufactured by East Asia Synthetic Co., Ltd., chemical name 1,4-bis[{(3-ethyl-3-epoxypropyl)methoxy}methyl]benzene.

[Radical Polymerizable Compound]

‧A-DCP: A-DCP manufactured by Shin-Nakamura Chemical Industry Co., Ltd., chemically named tricyclodecane dimethanol diacrylate.

‧A-DOG: A-DOG manufactured by Shin-Nakamura Chemical Industry Co., Ltd., chemically known as diacetate of acetal trimethylacetaldehyde and trimethylolpropane acetal compound

[In the above formula (2), Q ₁ = acryloxymethyl group, Q ₂ = 2-propenyloxy-1,1-dimethylethyl group, R = ethyl compound].

‧A-9300: A-9300, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., a triacrylate with a chemical name of 1,3,5-gin(2-hydroxyethyl)isocyanurate.

‧A-TMMT: A-TMMT manufactured by Shin-Nakamura Chemical Industry Co., Ltd., chemically named pentaerythritol tetraacrylate.

‧M-210: Aronix M-210, manufactured by East Asia Synthetic Co., Ltd., an ethylene oxide modified diacrylate of the chemical name bisphenol A.

‧ TMPTA: Chemical name is trimethylolpropane triacrylate.

‧ 702A: 702A, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., chemical name 2-hydroxy-3-phenoxypropyl acrylate

<evaluation test>

The following evaluation tests were carried out for the polarizing plates produced in Examples 1 to 8 and Comparative Examples 1 to 5. The results are shown in Table 2.

[1] adhesion test (cross hatch test)

Through the pressure-sensitive adhesive, the protective layer side of the polarizing plate is bonded to the glass, and the surface of the protective layer opposite to the glass surface is engraved into 100 1 mm square checkerboards by a cutter knife. A cellophane tape was attached thereto, and a peeling test was performed to evaluate the adhesion by the number of checkers left in the 100 checkerboards without being peeled off. The number of checkerboards left is evaluated as A at 95 to 100/100, B is evaluated at 50 to 95/100, and C is evaluated at 0 to 49/100.

[2] Temperature resistance test

The following temperature resistance test (warm water immersion test) was carried out to evaluate the water resistance of each polarizing plate. First, the absorption axis (stretching direction) of the polarizing plate was used as the long side, and the polarizing plate was cut into a strip-shaped sample of 5 cm × 2 cm, and then the dimension in the longitudinal direction was accurately measured. Due to the iodine adsorbed in the polyvinyl alcohol film, the sample at this time uniformly and uniformly exhibited a unique color. Fig. 1 is a schematic view showing a water resistance evaluation test method. Fig. 1(A) shows sample 1 before immersion in warm water, and Fig. 1(B) shows sample 1 after immersion in warm water. As shown in Fig. 1(A), after the short side of the sample was held by the nip portion 5, about 80% of the longitudinal direction was immersed in a water bath of 60 ° C for 4 hours. After that, the sample 1 was taken out from the water tank, and the water was wiped off.

The polarizing film 4 constituting the polarizing plate is shrunk by the impregnation of warm water. That is, as shown in Fig. 1(B), the polarizing film 4 positioned in the middle of the polarizing plate is shrunk by the immersion of warm water, so that the region 2 where the polarizing film 4 is absent is formed between the protective films. Then, the distance from the end side 1a of the sample 1 in the center of the short side (the end side of the protective film) to the end side of the contracted polarizing film 4 is taken as the contraction length. At the same time, iodine is eluted from the peripheral portion of the polarizing film 4 which is in contact with the warm water by the immersion of warm water, and the fading portion 3 is formed on the peripheral portion of the sample 1. The length of this fading portion is taken as the detached length of iodine. The total of these shrinkage lengths and the iodine peeling length is taken as the total erosion length X. In other words, the total erosion length X is the distance from the end side 1a of the sample 1 (the end side of the protective film) to the area where the polarizing plate has a characteristic color in the center of the short side of the sample 1. It can be judged that the smaller the total erosion length X, that is, the higher the adhesion (water resistance) in the presence of water. It is evaluated as A when the etching distance is less than 1,000 μm, B when it is 1,000 μm to 3,000 μm, and C when it is 3,000 μm or more.

[3] dimensional stability test

After each polarizing plate was placed in a dry environment at 85 ° C for 120 hours, the dimensional change was measured. First, the polarizing plate was cut into a size of 8 cm × 8 cm, and bonded to the glass through a pressure-sensitive adhesive as a measurement sample. The sample was autoclaved at a temperature of 50 ° C and a pressure of 5 kg/cm ² (490.3 kPa) for 1 hour, and then left to stand in an environment of a temperature of 23 ° C and a relative humidity of 55% for 24 hours. The size of this state was taken as the initial size, and after standing still in a dry environment of 85 ° C for 120 hours, the machine direction (MD) and the transverse direction were measured using a binary size measuring device (manufactured by Nikon, NEXIV VMR-12072). After the size of TD), the dimensional change rate is calculated by the following formula.

Dimensional change rate (%) = {(size after test - initial size) / initial size} × 100

In Table 2, the dimensional change rate in the MD direction (because the signs are all negative, it is the meaning of shrinkage). When the absolute value of the dimensional change rate is less than 0.7%, it is evaluated as A, 0.7% or more, and when it is less than 1.0%, it is B, 1.0% or more, and when it is less than 1.3%, it is C, and when it is 1.3% or more, it is D.

[4] Optical durability test

Each of the polarizing plates was left to stand in an environment of drying at 85 ° C or 60 ° C and a relative humidity of 90% to determine the optical properties as a function of time. In other words, first, the polarizing plate was cut into a size of 3 cm × 3 cm, and bonded to the glass through a pressure-sensitive adhesive as a measurement sample. The sample was autoclaved for 1 hour at a temperature of 50 ° C and a pressure of 5 kg/cm ² (490.3 kPa), and then placed in an environment of a temperature of 23 ° C and a relative humidity of 55% for 24 hours. After attaching the accessory "film holder with a polarizing film" to an ultraviolet-visible spectrophotometer (UV2450, manufactured by Shimadzu Corporation), the sample was measured for the wear of the polarizing plate in the wavelength range of 380 to 700 nm. The transmission spectrum of the direction of the through-axis and the direction of the absorption axis, and the polarization degree Py (unit: %) and the monomer transmittance Ty (unit: %) are obtained, and the monomer b of the single-color phase is obtained in accordance with JIS Z 8729. * (no unit). The optical properties of this state were taken as initial optical properties, and the optical properties after drying at 85 ° C or at 60 ° C and a relative humidity of 90% were measured for 120 hours, and the change in polarization degree ΔPy and monomer were calculated from the following formula. The transmittance change ΔTy and the hue change Δb*.

ΔPy = Py-initial Py after the test

ΔTy=Ty-initial Ty after test

Δb*=after test b*-initial b*

Further, for ΔPy, when the amount of change in the degree of polarization expressed by % is less than 1 point, it is evaluated as A, 1 point or more, and when it is less than 5 points, it is B, and when it is 5 points or more, it is C. For ΔTy, the amount of change in the transmittance indicated by % is estimated to be A when it is less than 3 points, B when it is less than 3 points, and not when it is 5 points, and C when it is 5 points or more. For Δb*, it is evaluated as A when the amount of change is less than 3, B when it is less than 5, and B when it is less than 5, and C when it is 5 or more. Table 2 shows the evaluation results of ΔPy and Δb* after standing at 85 ° C for drying, and the results of evaluation of ΔPy and ΔTy after standing at 60 ° C and a relative humidity of 90%.

[4] Film thickness measurement

The thickness of the entire polarizing plate (the laminated body of the upper and lower protective film and the polarizing film) was measured by a film thickness measuring instrument (ZC-101, manufactured by Nikon Co., Ltd.).

As is clear from Table 2, in the examples, a polarizing plate having a film having excellent adhesion to a polarizing film and having excellent water resistance, dimensional stability, and optical durability was obtained.

The embodiments and examples disclosed in the present disclosure are merely illustrative and not limiting. The scope of the present invention is to be construed as being limited by the scope of the claims and the scope of the claims.

1. . . Sample

1a. . . End edge

2. . . Area where there is no polarizing film between the protective films

3. . . The faded part of the periphery of the polarizer

4. . . Shrinking polarizing film

5. . . Grip

Fig. 1 is a schematic view showing a water resistance evaluation test method in the examples. Fig. 1(A) shows sample 1 before warm water immersion, and Fig. 1(B) shows sample 1 after warm water immersion.

1. . . Sample

1a. . . End edge

2. . . Area where there is no polarizing film between the protective films

3. . . The faded part of the periphery of the polarizer

4. . . Shrinking polarizing film

5. . . Grip

Claims (13)

A polarizing plate comprising: a polarizing film that adsorbs a dichroic dye in a polyvinyl alcohol-based resin film; and a protective layer formed on at least one surface of the polarizing film, wherein the protective layer is composed of an active energy ray-curable compound The hardened resin composition is formed of a cured product having at least one epoxy group in the molecule; and at least one (meth)acryloxy group in the molecule (of the active energy ray-curable compound) A methyl)acrylic compound having a modulus of elasticity of from 3,300 to 10,000 MPa. The polarizing plate of the first aspect of the invention, wherein the (meth)acrylic compound is contained in an amount of 10 to 70 parts by weight based on 100 parts by weight of the active energy ray-curable compound. The polarizing plate of claim 1, wherein the (meth)acrylic compound provides an elastic modulus of 3,000 MPa or more for a cured product formed only of the (meth)acrylic compound and a polymerization initiator. By. The polarizing plate of claim 1, wherein the (meth)acrylic compound is at least one compound represented by the following formulas (1) to (4): (In the above formulas (1) and (2), Q ₁ and Q ₂ each independently represent a (meth) acryloxy group or a (meth) propylene decyloxy group, and the carbon number of the alkyl group is 1 at this time. To the above formula (2), R represents hydrogen or a hydrocarbon group having 1 to 10 carbon atoms; in the above formula (3), T ₁ , T ₂ and T ₃ each independently represent a (meth) acryloxy group; In the above formula (4), T represents a hydroxyl group or a (meth)acryloxy group). The polarizing plate of claim 1, wherein the curable resin composition further contains an oxetane compound. The polarizing plate of claim 1, wherein the curable resin composition contains fine particles. The polarizing plate of the sixth aspect of the invention, wherein the curable resin composition contains 5 to 250 parts by weight of fine particles with respect to 100 parts by weight of the active energy ray-curable compound. The polarizing plate of claim 6, wherein the fine particles are cerium oxide particles having a particle diameter of 100 nm or less. The polarizing plate of claim 8, wherein the cerium oxide microparticles have one or more selected from the group consisting of a hydroxyl group, an epoxy group, a (meth) acryloxy group, and a vinyl group. Functional group. The polarizing plate of claim 1, wherein the protective layer has a thickness of 1 to 35 μm. An optical component formed by a laminate of a polarizing plate and an optical functional layer according to any one of claims 1 to 10. The optical component according to claim 11, wherein the optical functional layer is any one of a retardation layer, a brightness enhancement film, and a surface treatment layer. A liquid crystal display device in which a polarizing plate according to any one of claims 1 to 10, or an optical component of claim 11 or 12 is disposed on one or both sides of a liquid crystal cell Former.