KR20120030445A - Luminance improving film having adhesive layer, polarizing plate, and liquid crystal display device comprising the luminance improving film and the polarizing plate - Google Patents

Abstract

A brightness enhancement film provided with a transparent film on at least one side of a resin layer having cholesteric regularity through an active energy ray-curable adhesive layer, wherein the active energy ray-curable adhesive layer is made by curing an active energy ray-curable adhesive composition, In the uncured state of the composition, (A) an oligomeric polyfunctional (meth) acrylate having 3 or less functional groups, and (B) a hydroxyl group in a molecule having a viscosity at a temperature of 20 ± 1.0 ° C of not less than 10 mPa · s and less than 500 mPa · s. At least one mono (meth) acrylate having at least one. Thereby, in the brightness | luminance improvement film which has a resin layer which has cholesteric regularity, it becomes difficult to make deformation and a wound of the resin layer which has cholesteric regularity, and when used as a liquid crystal display device, The brightness and display characteristics can be excellent.

Description

LUMINANCE IMPROVING FILM HAVING ADHESIVE LAYER, POLARIZING PLATE, AND LIQUID CRYSTAL DISPLAY DEVICE COMPRISING THE LUMINANCE IMPROVING FILM AND THE POLARIZING PLATE}

This invention relates to a brightness improving film, its manufacturing method, a polarizing plate, and a liquid crystal display device.

In display devices, such as a liquid crystal display device, in order to improve the performance, providing various optical members is known. For example, in a liquid crystal display device, it is known to provide a brightness improving film as one method for effectively utilizing the light from a backlight to improve brightness and to improve luminous efficiency. As a brightness improving film, what laminated | stacked the resin layer which has cholesteric regularity (henceforth "cholesteric resin layer" suitably), and a 1/4 wavelength plate in this order through an adhesive layer etc. is used, for example. (Patent Document 1). In formation of a cholesteric resin layer, the method of peeling a cholesteric resin layer formed on the coating base material which has an oriented film, and transferring it to another translucent board | substrate is proposed (patent document 2). Such a brightness improving film is capable of separating the roles of the alignment substrate and the light transmissive substrate, has a small number of films, and can be directly laminated with the polarizing plate, which is advantageous in terms of thinning and cost.

Japanese Patent Publication No. 1995-36025 Japanese Patent Publication No. 1995-113993

However, since the cholesteric resin layer is exposed when the brightness enhancement film produced by this transfer is directly laminated with other optical elements such as a prism sheet, the surface of the cholesteric resin layer is very easily damaged. However, when the cholesteric resin layer is easily deformed and used as a member of the liquid crystal display device, there is a problem that an optical defect is likely to occur.

In addition, when the cholesteric resin layer formed on the coated substrate having the alignment film is peeled off and transferred onto another light-transmissive substrate, there is a problem that cracks easily occur in the resin layer due to the stress applied to the cholesteric resin layer. there was.

In addition, depending on the pressure-sensitive adhesive used when bonding the base material supporting the cholesteric resin layer and the cholesteric resin layer, the self-supportability is insufficient, and there is a problem that deformation is seen in heat or environmental tests when the backlight is turned on. there was.

This invention is a liquid crystal display excellent in thinness, brightness, and display characteristics, when it is hard to make a deformation | transformation and a wound | wound of a cholesteric resin layer, and is used as a liquid crystal display device in the brightness improvement film which has a cholesteric resin layer. A subject is development of the polarizing member which can form a device.

MEANS TO SOLVE THE PROBLEM As a result of examining in order to solve the said subject, it discovered that the said subject can be solved by providing a transparent film in at least one surface of a cholesteric resin layer through a specific active energy ray hardening-type adhesive layer, and this invention Completed.

That is, according to the present invention, the following [1] to [9] are provided.

[1] A brightness improving film provided with a transparent film on at least one side of a resin layer having cholesteric regularity through an active energy ray-curable adhesive layer,

The active energy ray-curable adhesive layer is made by curing an active energy ray-curable adhesive composition,

With the adhesive composition uncured

(A) an oligomeric polyfunctional (meth) acrylate having 3 or less functional groups, and

(B) Mono (meth) acrylate which has at least one hydroxyl group in the molecule whose viscosity in temperature 20 +/- 1.0 degreeC is 10 mPa * s or more and less than 500 mPa * s.

A brightness enhancement film comprising at least.

[2] The brightness improving film according to [1], wherein the content of (B) is in a range of 35 to 85 parts by weight in 100 parts by weight of the (meth) acrylate contained in the uncured adhesive composition.

[3] [1] or [1], wherein (A) is at least one oligomeric (meth) acrylate selected from the group consisting of urethane (meth) acrylates, epoxy (meth) acrylates, and polyester (meth) acrylates. The brightness improvement film of 2].

[4] The adhesive composition in the uncured state is further

(C) The brightness improvement film as described in [1]-[3] containing the inert polymer whose glass transition temperature is -10 degreeC or more and 80 degrees C or less.

[5] The brightness improving film according to any one of [1] to [4], wherein the transparent film is a λ / 4 plate.

[6] A polarizing plate, wherein a transparent protective film is provided on both surfaces of the polarizer, and the luminance improving film according to any one of [1] to [5] is bonded to one surface thereof.

[7] A polarizing plate, wherein a transparent protective film is provided on one side of the polarizer, and the luminance improving film according to any one of [1] to [5] is bonded to the other side.

[8] A liquid crystal display device comprising the luminance improving film according to any one of [1] to [5].

[9] A liquid crystal display device wherein the polarizing plate according to [6] or [7] is bonded to the illuminating device side of the liquid crystal cell.

The luminance improvement film of this invention has few wounds and deformation | transformation of a cholesteric resin layer, and when integrated with a polarizing plate and used for a liquid crystal display device, thickness reduction, brightness | luminance, and a brightness | luminance uniformity can be improved favorably, and it is lightweight and low cost I can do it with a device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows notionally embodiment of the brightness improving film of this invention.
It is a longitudinal cross-sectional view which manufactures on a coating base material and conceptually shows the state before peeling, when manufacturing the brightness improving film of this invention.
3 is a longitudinal sectional view conceptually showing an embodiment of the polarizing plate of the present invention.
It is a longitudinal cross-sectional view which shows another embodiment of the polarizing plate of this invention conceptually, and has shown that one sheet of the protective film of a polarizing plate can be substituted by the brightness improving film compared with the embodiment of FIG.

1. Brightness improvement film of this invention

The brightness improving film of this invention is equipped with the cholesteric resin layer. Moreover, the brightness improving film of this invention is equipped with the transparent film in at least one surface of a cholesteric resin layer through an active energy ray hardening-type adhesive layer. In addition, the transparent film may be provided in both surfaces of the cholesteric resin layer.

1-1. Transparent film

As a transparent film, a quarter wave plate (it may be called "(lambda) / 4 plate).), A protective film, etc. can be illustrated.

(1/4 wave plate)

As a quarter wave plate, the stretched film formed by extending | stretching a film-form polymer can be used, for example. As a polymer, transparent resin can be used preferably, The said transparent resin can use the thing of 80% or more of the total light transmittance with a 1 mm thick plate, for example. For example, polymethyl methacrylate, polystyrene, polycarbonate, polyether sulfone, amorphous polyethylene, triacetyl cellulose, resin having an alicyclic structure, etc. may be mentioned. As a preferable example, the quarter wave plate formed by extending | stretching the resin film which has an alicyclic structure and the quarter wave plate formed by extending | stretching the resin film containing a styrene resin layer are mentioned. More preferably, the optically anisotropic element mentioned below is mentioned.

The 1/4 wavelength plate can make the retardation Re (it may abbreviate as "Re" hereafter) of the front direction into approximately 1/4 wavelength of transmitted light. Here, the wavelength range of transmitted light can be made into the desired range calculated | required by a composite optical member, specifically, it is 400 nm-700 nm, for example. The retardation Re in the front direction is approximately 1/4 wavelength of the transmitted light, where the Re value is ± 65 nm from the value of 1/4 of the center value, preferably ± 30 nm in the center value of the wavelength range of the transmitted light. More preferably, it is the range of +/- 10 nm. By having such a retardation value, a polarization conversion function, ie, the function which converts circularly polarized light into linearly polarized light, can be expressed.

The quarter wave plate preferably has a retardation Rth (hereinafter sometimes abbreviated as "Rth") in the thickness direction of less than 0 nm. The value of the retardation Rth in the thickness direction is preferably -30 nm to -1000 nm, and more preferably -50 nm to -300 nm in the center value of the wavelength range of the transmitted light. By employing the optically anisotropic element having such a Re value and Rth, the luminance can be improved to reduce the luminance nonuniformity, while reducing the color nonuniformity of the emitted light.

Here, the retardation Re in the front direction is represented by the formula I: Re = (nx-ny) × d (wherein nx represents a refractive index in a direction perpendicular to the thickness direction (in-plane direction) and provides a maximum refractive index. , ny is a direction perpendicular to the thickness direction (in-plane direction) and represents a refractive index in a direction orthogonal to nx, and d represents a film thickness.), and the retardation Rth in the thickness direction is represented by Expression II: Rth. = {(nx + ny) / 2-nz} × d (wherein nx represents the refractive index of the direction perpendicular to the thickness direction (in-plane direction) and provides the maximum refractive index, and ny represents the direction perpendicular to the thickness direction (In-plane direction) and a refractive index in a direction orthogonal to nx, nz represents a refractive index in the thickness direction, and d represents a film thickness.

On the other hand, the retardation Re in the front direction and the retardation Rth in the thickness direction use a commercially available phase difference measuring device, and the 1/4 wave plate is spaced 100 mm apart in the long direction and the width direction (the length in the long direction or the horizontal direction is When it does not occupy 200 mm, it measures in the grid | lattice point shape over the whole surface by three points at equal intervals in the direction), and makes it the average value.

Although the material of the optically anisotropic element which comprises a quarter wave plate is not specifically limited, What has a layer which consists of styrene resin can be used preferably. Here, styrene resin is a polymer resin which has a styrene structure as a part or all part of a repeating unit, and can use polystyrene or the copolymer of styrene and maleic anhydride suitably.

Although the molecular weight of the styrene resin used for an optically anisotropic element is suitably selected according to a use purpose, it is normally 10,000 or more and 300,000 or less in the weight average molecular weight (Mw) of polyisoprene measured by gel permeation chromatography using cyclohexane as a solvent. Preferably they are 15,000 or more and 250,000 or less, More preferably, they are 20,000 or more and 200,000 or less.

The optically anisotropic element preferably has a laminated structure of a layer made of the styrene resin and a layer made of another thermoplastic resin. By having the said laminated structure, it can be set as the element which has the optical characteristic by styrene resin, and the mechanical strength by another thermoplastic resin. As another thermoplastic resin, resin and methacryl resin which have alicyclic structure can be used suitably.

As resin which has alicyclic structure, alicyclic olefin polymer is mentioned, for example. The alicyclic olefin polymer is an amorphous olefin polymer having a cycloalkane structure or a cycloalkene structure in the main chain and / or the side chain.

The methacrylic resin is a polymer containing methacrylic acid ester as a main component, and examples thereof include homopolymers of methacrylic acid esters and copolymers of methacrylic acid esters and other monomers. As methacrylic acid ester, alkyl methacrylate is usually used. When making it into a copolymer, as another monomer copolymerized with methacrylic acid ester, an acrylic acid ester, an aromatic vinyl compound, a vinyl cyan compound, etc. are used.

As a preferable specific aspect of a quarter wave plate, the stretched multilayer film formed by extending | stretching the multilayer film formed by laminating | stacking the film (b layer) which consists of another thermoplastic resin on both surfaces of the film (a layer) which consists of polystyrene resins is mentioned. have. Hereinafter, this specific aspect is demonstrated.

As polystyrene resin which comprises the said a layer, the same thing as said "styrene resin" can be used.

Although the method of laminating | stacking the said polystyrene resin which is a material of a layer and the said other thermoplastic resin which is a material of b layer, and shape | molding into a multilayer film is not specifically limited, Coextrusion T die method, a coextrusion inflation method, a coextrusion lamination method, etc. Well-known methods, such as a shaping | molding method by coextrusion, a film lamination shaping | molding method, such as dry lamination, and a coating shaping | molding method, can be used suitably. Especially, the shaping | molding method by coextrusion is preferable from a viewpoint of manufacturing efficiency and not remaining volatile components, such as a solvent, in a film. Extrusion temperature can be suitably selected according to the kind of the said polystyrene resin and the said other thermoplastic resin to be used.

A multilayer film is obtained by laminating the b layer on both surfaces of the a layer. Although an adhesion layer can be provided between a layer and b layer, it is preferable to laminate | stack a layer and b layer directly (namely, it is set as the laminated body of 3-layer structure of b layer / a layer / b layer). Moreover, in a multilayer film, although the thickness of the said a layer and the b layer laminated | stacked on both surfaces is not specifically limited, Preferably it can be 10 micrometers or more and 300 micrometers or less, and 10 micrometers or more and 400 micrometers or less, respectively.

The stretched multilayer film is formed by stretching the multilayer film. Said extending | stretching can be performed preferably by uniaxial stretching or diagonal stretch, More preferably, it can carry out by uniaxial stretching or diagonal stretch by a tenter.

The thickness of the optically anisotropic element is preferably 50 µm or more and 1000 µm or less, and more preferably 50 µm or more and 600 µm or less.

Although the quarter wave plate may itself have a function as an optical compensation layer, in addition to the quarter wave plate, it may have a separate optical compensation layer. As such an optical compensation layer, the same thing as the above-mentioned optically anisotropic element can be used, The homeotropic liquid crystal aligning film (Japanese Patent No. 3992969) which hardened liquid crystal molecules on the board | substrate by hardening, and liquid crystal on the board | substrate A nematic hybrid liquid crystal aligning film (US Pat. No. 6294229) can be used that cures a state in which molecules are nematically hybrid oriented.

(Protective film)

As a protective film which protects a cholesteric resin layer, a transparent resin film can be used. As transparent resin, the same thing as what was used for a quarter wave plate can be used. Especially preferably, the resin film which has the unstretched alicyclic structure with favorable heat resistance and transparency can be used.

Unevenness | corrugation can be provided in a protective film in the surface on the opposite side to the surface which opposes a cholesteric resin layer. By providing unevenness, a wound can be prevented by improving adhesion prevention and slipperiness with other backlight members (namely, members other than the brightness improvement film which comprises a backlight).

As a means for providing the unevenness, a method of transferring a predetermined shape onto the transparent resin film surface by pushing a mold having a predetermined shape onto the transparent resin film surface while heating; A method of swelling the transparent resin film surface with a solvent in which the resin dissolves and pushing a mold having a predetermined shape to transfer the predetermined shape to the transparent resin film surface; Translucent particles of a predetermined particle size are dispersed in a solution in which the resin is dissolved in a solvent, and the solution is coated on the surface of the transparent resin film by a bar coating method, a gravure coating method, a die coating method, a spray coating method, a dip coating method, and a spin coating method. Coating, drying, hardening, a method of providing unevenness, etc. are mentioned.

Among these, the method of coating the transparent resin film surface with the solution which disperse | distributed the translucent particle which was excellent in manufacturing elongation to a resin solution in the resin solution is preferable.

The surface roughness of the protective film which provided the unevenness | corrugation on the surface can be measured based on JIS B0601-1994. The 10-point average roughness and the average length of the contour curve element are measured for 10 points in the plane at a measurement length of 5 µm, and the average value of the 10-point measurement value is calculated from the 10-point average roughness Rz of the measurement target and the average length Sm of the contour curve element. can do.

The preferable 10-point average roughness Rz of the surface on which the unevenness is provided and the ratio Rz / Sm of the average length Sm are in the range of 2 × 10 ^{−4 to} 7 × 10 ⁻³ , and more preferably 3 × 10 ^{−4 to} 5 × 10 ^-3 , More preferably, it is 5 * 10 <^-4> -4.5 * 10 <^-3> .

1-2. Cholesteric resin layer (transfer of coating film)

(Cholesteric resin layer)

A cholesteric resin layer (that is, a resin layer having cholesteric regularity) is a resin layer formed by providing a coating film of a cholesteric liquid crystal composition on a substrate for resin layer formation and curing the coating film.

The cholesteric regularity means that the molecular axis is aligned side by side in a constant direction on one plane, but in the state that the direction of the molecular axis is slightly deviated at an angle in the next plane, and the angle is further deviated in the next plane. As the plane is arranged in the direction, the angle of the molecular axis is shifted. The structure in which the direction of the molecular axis is distorted as described above becomes an optically chiral structure.

It is preferable that the brightness improving film which concerns on this invention is equipped with the cholesteric resin layer which exhibits this circularly polarized light separation function over the full wavelength region of visible light. For example, it is preferable that it is a cholesteric resin layer which has a circularly polarized light separation function with respect to the light of any wavelength range of blue (wavelength 410-470 nm), green (wavelength 520-580 nm), and red (wavelength 600-660 nm).

A cholesteric resin layer can be obtained by superposing | polymerizing the cholesteric liquid crystal composition (X) containing a polymeric liquid crystalline compound, for example in the process of hardening mentioned later. Such a layer becomes a non-liquid crystalline resin layer cured while showing the molecular orientation of the liquid crystal compound. In addition, the material called a liquid crystal composition here for convenience includes not only the mixture of 2 or more substances but the material which consists of a single substance.

The cholesteric liquid crystal composition (X) contains a compound represented by the following formula (1) and a rod-like liquid crystal compound as a polymerizable liquid crystal compound.

In Formula 1, R ^1X and R ^2X are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, a linear or branched alkylene oxide group having 1 to 20 carbon atoms, a hydrogen atom, It is group chosen from the group which consists of a halogen atom, a hydroxyl group, a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, an amino group, and a cyano group. Here, (meth) acryl means the acryl and methacryl.

The alkyl group and alkylene oxide group may be unsubstituted or may be substituted with one or more halogen atoms. The halogen atom, hydroxyl group, carboxyl group, (meth) acryl group, epoxy group, mercapto group, isocyanate group, amino group, and cyano group are bonded to an alkyl group having 1 to 2 carbon atoms, an alkylene oxide group, You may be.

Preferable examples of R ^1X and R ^2X include a halogen atom, a hydroxyl group, a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, an amino group, and a cyano group.

In addition, it is preferable that at least one of R <^1X> and R <^2X> is a reactive group. By having a reactive group as R ^1X and / or R ^2X , the compound represented by the formula (1) can be fixed in the layer of the liquid crystal composition at the time of curing, thereby forming a stronger film. Examples of the reactive group include a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, and an amino group.

In Formula 1, A ^1X and A ^2X are each independently 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, 4,4'-biphenylene group, 4,4 Group selected from the group consisting of a '-bicyclohexylene group and a 2,6-naphthylene group. The 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, 4,4'-biphenylene group, 4,4'-bicyclohexylene group, and 2,6- The naphthylene group may be unsubstituted or may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, cyano groups, amino groups, alkyl groups having 1 to 10 carbon atoms, and halogenated alkyl groups. In each of A ^1X and A ^2X , when two or more substituents are present, they may be the same or different.

Particularly preferred ^examples of A ^1X and A ^2X include a group selected from the group consisting of a 1,4-phenylene group, a 4,4'-biphenylene group, and a 2,6-naphthylene group. These aromatic ring skeletons are relatively rigid as compared with the alicyclic skeleton, have high affinity with mesogen of the rod-like liquid crystalline compound described later, and higher in alignment uniformity.

In Formula 1, Z is a single bond, -O-, -S-, -SS-, -CO-, -CS-, -OCO-, -CH _2- , -OCH _2- , -CH = NN = CH -, -NHCO-, -OCOO-, -CH ₂ COO-, and -CH ₂ OCO-.

Particularly preferred examples of Z include single bonds, -OCO-, and -CH = N-N = CH-.

It is preferable that at least 1 sort (s) of the compound of General formula (1) has liquid crystallinity, and it is preferable to have chirality. In addition, the cholesteric liquid crystal composition (X) preferably contains a mixture of a plurality of optical isomers as a compound of the general formula (1). For example, it may contain a mixture of plural kinds of enantiomers and / or diastereomers.

It is preferable that the melting | fusing point of at least 1 sort (s) of the compound of General formula (1) exists in the range of 50 degreeC-150 degreeC.

When the compound of Formula 1 has liquid crystallinity, it is preferable that the refractive index anisotropy Δn is high. By selecting a material with a high Δn, it can be prevented from inhibiting the effect of Δn that the liquid crystal compound has. At least one Δn of the compound of the formula (1) is preferably 0.20 or more, more preferably 0.22 or more. However, when Δn increases, the film thickness of the required cholesteric resin layer tends to be remarkably small. Therefore, when Δn exceeds 0.4, the film thickness may be less than 1 µm. If it is less than 1 micrometer, since optical characteristics will be sensitively influenced by the gap of film thickness, it will become difficult to manufacture. Therefore, in such a case, it is preferable that the upper limit of (DELTA) n shall be 0.4.

Particularly preferred examples of the compound of the formula (1) include the following compounds (A1) to (A9):

In the said compound (A3), "*" represents a chiral center.

The cholesteric liquid crystal composition (X) preferably contains a rod-like liquid crystal compound having at least two or more reactive groups in one molecule. As said rod-like liquid crystalline compound, the compound represented by General formula (2) is mentioned.

In formula (2), R ^3X and R ^4X are reactive groups, and each independently a (meth) acryl group, a (thio) epoxy group, an oxetane group, a thioethanyl group, an aziridinyl group, a pyrrole group, a vinyl group, an allyl group And a group selected from the group consisting of a fumarate group, cinnamoyl group, oxazoline group, mercapto group, iso (thio) cyanate group, amino group, hydroxyl group, carboxyl group, and alkoxysilyl group.

In formula (2), D ^3X and D ^4X are a single bond, a divalent saturated hydrocarbon group such as a linear or branched methylene group and an alkylene group having 1 to 20 carbon atoms, and a straight chain having 1 to 20 carbon atoms Or a group selected from the group consisting of branched alkylene oxide groups.

In Chemical Formula 2, C ^3X -C ^6X is a single bond, -O-, -S-, -SS-, -CO-, -CS-, -OCO-, -CH _2- , -OCH _2- , -CH = NN = CH-, denotes a group selected from -NHCO-, -OCOO-, a group consisting of -CH ₂ COO-, and -CH ₂ OCO-.

In Formula (2), M represents a mesogenic group, specifically, azomethines, azoxy groups, phenyls, biphenyls, terphenyls, naphthalenes, anthracenes, and benzoic acid, which may have an unsubstituted or substituent. Group of esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexane, cyano substituted phenylpyrimidines, alkoxy substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenyl cyclohexylbenzonitriles 2-4 skeletons selected from -O-, -S-, -SS-, -CO-, -CS-, -OCO-, -CH _2- , -OCH _2- , -CH = NN = CH- And groups formed by bonding with a bonding group such as -NHCO-, -OCOO-, -CH ₂ COO-, and -CH ₂ OCO-.

It is preferable that the said rod-shaped liquid crystalline compound has an asymmetric structure. Herein, the asymmetric structure means that in the formula (2), R ^3X -C ^3X -D ^3X -C ^5X -and -C ^6X -D ^4X -C ^4X -R ^4X are different structures around the mesogenic group M. As said rod-like liquid crystalline compound, orientation uniformity can be improved more by using the thing of an asymmetric structure.

The rod-like liquid crystal compound may be one having at least two or more reactive groups in one molecule. Specifically as said reactive group, an epoxy group, a thioepoxy group, an oxetane group, a thiethanyl group, an aziridinyl group, a pyrrole group, a fumarate group, a cinnamoyl group, an isocyanate group, an isothiocyanate group , Amino group, hydroxyl group, carboxyl group, alkoxysilyl group, oxazoline group, mercapto group, vinyl group, allyl group, methacryl group, and acryl group.

In the cholesteric liquid crystal composition (X), the weight ratio of (total weight of the compound of Formula 1) / (total weight of rod-like liquid crystalline compound) is preferably 0.05 to 1, more preferably 0.1 to 0.65. It is more preferable that it is 0.15-0.45. When the said weight ratio is less than 0.05, orientation uniformity may become inadequate. Moreover, when more than 1, orientation uniformity may fall, stability of a liquid crystal phase may fall, (DELTA) n as a liquid crystal composition may fall, and a desired optical performance (for example, circularly polarized light separation characteristic) may not be obtained. In addition, a total weight shows the weight of the total when using 1 type, and when using 2 or more types.

The cholesteric liquid crystal composition may optionally contain a chiral agent. As an example of a specific chiral agent, the compound represented by following (C1) and (C2) which has an isosorbide skeleton whose chiral group is bivalent can be used. In addition, commercially available chiral agents include, for example, LC756 of BASF's Paliocolor.

The chiral agent may be included in a range that does not lower the desired optical performance. The content rate of the said chiral agent is 1-60 weight% normally in the said cholesteric liquid crystal composition.

The cholesteric liquid crystal composition may further contain other arbitrary components as needed. Examples of the other optional components include solvents, photopolymerization initiators, surfactants, crosslinking agents, polymerization inhibitors for enhancing port life, antioxidants for improving durability, ultraviolet absorbers, light stabilizers, and the like. These arbitrary components can be included in the range which does not reduce desired optical performance.

The manufacturing method of a cholesteric liquid crystal composition is not specifically limited, It can manufacture by mixing each said component.

As a manufacturing method of a cholesteric resin layer, the said cholesteric liquid crystal composition is apply | coated on a base material layer directly or through an orientation film, and a coating film is obtained, and then one or more times of light irradiation and / or heat processing are performed, A cholesteric resin layer can be obtained by hardening a coating film. More specifically, the cholesteric resin layer can be manufactured by the method of following (M1) and (M2).

(M1) As said base material layer, a cholesteric resin layer can be provided directly on it using a transparent film, such as a quarter wave plate. For example, the laminated structure of a quarter wave plate and a cholesteric resin layer can be obtained by using a quarter wave plate as a base material layer, and forming a cholesteric resin layer thereon.

(M2) Using an arbitrary base material layer, a cholesteric resin layer is formed thereon, a cholesteric resin layer is transferred to a transparent film through an adhesive composition, etc., a base material layer is peeled off, and a cholesteric material is transparent to a transparent film. You may provide a resin layer. By doing in this way, the laminated structure without a base material of a quarter wave plate and a cholesteric resin layer can be obtained through an adhesive layer, for example.

As the base material layer, a transparent resin base material can be preferably used. The thing similar to what was used for the quarter wave plate can be used for the said transparent resin base material. Especially, an alicyclic olefin polymer or a linear olefin polymer is preferable, and an alicyclic olefin polymer is especially preferable from a viewpoint of transparency, low hygroscopicity, dimensional stability, light weight, etc.

An alignment film can be provided on the said base material layer as needed. By providing the alignment film, the cholesteric liquid crystal composition applied thereon can be oriented in a desired direction. The alignment film is subjected to corona discharge treatment or the like on the surface of the substrate layer, if necessary, and then a solution obtained by dissolving the material of the alignment film in water or a solvent, such as reverse gravure coating, direct gravure coating, die coating, bar coating, or the like. It can form by apply | coating using a well-known method, making it dry, and performing a rubbing process to a dry coating film after that. As a material of the said oriented film, modified polyamide is preferable from a viewpoint of durability. On the other hand, polyvinyl alcohol is particularly preferable from the viewpoint of the ease of transfer in the method (M2).

As said modified polyamide, what modified | denatured to aromatic polyamide or aliphatic polyamide is mentioned, What modified | denatured to aliphatic polyamide is preferable.

Before hardening the coating film obtained by the said application, you may perform an orientation process as needed. An orientation process is performed by heating a coating film at 50-150 degreeC for 0.5 to 10 minutes, for example. By performing the said orientation process, the substance which can show the cholesteric liquid crystal phase in a coating film can be oriented favorably.

The hardening process is performed by one or more times of light irradiation, heat processing, or a combination thereof. Heating conditions are 40-200 degreeC, for example, Preferably it is 50-200 degreeC, More preferably, it is 50-140 degreeC, Time is 1 second-3 minutes, Preferably it is 5 to 120 second. On the other hand, light used for light irradiation includes not only visible light but also ultraviolet rays and other electromagnetic waves. Light irradiation can be performed by irradiating 0.01 second-3 minutes of light of a wavelength of 200-500 nm, for example.

Further, as a treatment for widening, for example, a weak ultraviolet irradiation and heating of 0.01 to 50 mJ / cm ² may be repeated alternately a plurality of times, and a circular polarization splitting element having a broad reflection band may be used. After expansion of the reflection band by the above-mentioned weak ultraviolet irradiation etc., comparatively strong ultraviolet-rays of 50-10,000mJ / cm <^2> are irradiated, and a liquid crystalline compound is fully polymerized and it can be set as a cholesteric resin layer. The expansion of the reflection band and the irradiation of strong ultraviolet rays may be performed under air, or part or all of the steps may be performed in an atmosphere in which oxygen concentration is controlled (for example, under a nitrogen atmosphere).

The dry film thickness of the cholesteric resin layer is preferably 10 µm or less, more preferably 2 µm or more and 7 µm or less, still more preferably 3 µm or more and 6 µm or less. By setting the film thickness to 10 µm or less, the change in color when observed in the inclined direction can be reduced, while the sufficient reflectance can be obtained by setting it to 2 µm or more. In addition, the said dry film thickness refers to the sum total of the film thickness of each layer, when a cholesteric resin layer is two or more layers, and the film thickness when a cholesteric resin layer is one layer.

Transfer in the said method (M2) can be performed by transferring the cholesteric resin layer formed on the base material or orientation film for resin layer formation onto the layer used as a transfer object. Such transfer can be performed such that the layer to be transferred and the cholesteric resin layer are attached through the adhesive layer. The layer to be transferred can be a transparent film, for example, a quarter wave plate.

Prior to the transfer, the adhesive layer may be provided in advance on any one or both of the surfaces on which both sides of the transfer target layer and the cholesteric resin layer face each other.

When the cholesteric resin layer is formed on the alignment film, only the cholesteric resin layer may be transferred, but the cholesteric resin layer and the alignment film may also be transferred together. It is preferable to transfer together a cholesteric resin layer and an orientation film from a viewpoint of the ease of peeling and the prevention of the orientation defect generation of a cholesteric resin layer.

1-3. Adhesive layer

The adhesive layer (active energy ray-curable adhesive layer) used in the present invention is an adhesive layer formed by curing an active energy ray-curable adhesive composition (also called an adhesive layer composition). The said adhesive composition is an oligomer type polyfunctional (meth) acrylate which has (A) functional group number 3 or less in uncured state, and (B) hydroxyl group whose viscosity in temperature 20 +/- 1.0 degreeC is 10 mPa * s or more and less than 500 mPa * s. It includes a mono (meth) acrylate having at least one. Here, (meth) acrylate means the acrylate and / or methacrylate.

An active energy ray hardening-type adhesive composition means the adhesive composition which hardens when irradiating an active energy ray, such as an ultraviolet-ray, an X-ray, an electron beam, etc.,. Since an inexpensive device can be used, an adhesive composition which is cured by ultraviolet rays is preferable. The light source used for irradiating an ultraviolet-ray is not specifically limited, For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excited mercury lamp, a metal halide lamp, etc. are mentioned. Although irradiation intensity | strength is not specifically limited, It is preferable that the irradiation intensity | strength of the wavelength range effective for activation of a polymerization initiator is 50-5000mW / cm <^2> . More preferably, it is 100-3000 mW / cm <^2> , More preferably, it is 300-2000 mW / cm <^2> . When light irradiation intensity is less than 50 mW / cm <^2> , reaction time becomes long and hardening becomes insufficient. When it exceeds 5000 mW / cm ² , the adhesive composition may be yellowed due to radiant heat from the lamp, heat of polymerization reaction, or the like, and curing shrinkage of the adhesive layer may increase, resulting in a decrease in adhesive strength. Light irradiation time is suitably selected according to a hardening situation, Although it does not specifically limit, It is preferable to set so that the accumulated light amount displayed as a product of irradiation intensity and irradiation time may be set to 10-5,000 mJ / cm <^2> . More preferably, it is 100-3000mJ / cm <^2> , More preferably, it is 500-2000mJ / cm <^2> .

Each component is demonstrated below.

(A) Oligomeric polyfunctional (meth) acrylates having 3 or less functional groups

The oligomer-type polyfunctional (meth) acrylate having 3 or less functional groups used in the present invention is preferably 2 or 3 functional groups. Examples of the oligomeric polyfunctional (meth) acrylates include polyester (meth) acrylates, epoxy (meth) acrylates, urethane (meth) acrylates, polyether (meth) acrylates and silicone (meth) acrylates. Single or a mixture of these can be exemplified by acrylic oligomers having various functional groups having 3 or less radical polymerizability.

In addition, a functional group refers to the group which has an unsaturated bond here. As a functional group, following (r-1)-(r-8) is mentioned, for example, Especially, the (meth) acryloyl group containing (r-1)-(r-5) etc. is preferable. In addition, only one type of functional group may be used and you may use it combining two or more types by arbitrary ratios. In addition, Et represents an ethyl group and n-Pr represents an n-propyl group.

The molecular weight of an oligomer type polyfunctional (meth) acrylate is 500 or more and 10000 or less in the weight average molecular weight (Mw) of polyisoprene conversion measured by the gel permeation chromatography.

Polyester (meth) acrylate is obtained by making terminal hydroxyl group of the polyester obtained from a polybasic acid and a polyhydric alcohol react with (meth) acrylic acid.

Examples of the polybasic acid include phthalic acid, adipic acid, maleic acid, itaconic acid, succinic acid and terephthalic acid.

Examples of the polyhydric alcohol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and the like.

For example, EBECRYL 851, 852, 853, 884, 885 (made by Daicel-Cytec Company Ltd.), Olester (made by Mitsui Chemicals Inc.), Aronix M-6100, 6200, 6250, 6500 (made by TOAGOSEI Co., Ltd.), etc. are mentioned.

Epoxy (meth) acrylate is a reactant which ring-opened-reacted (meth) acrylic acid to epoxy resin.

Examples of the epoxy resin include bisphenol A type composed of bisphenol A and epichlorohydrin, novolac type composed of phenol novolac and epichlorohydrin, aliphatic type and alicyclic type. Examples of the aliphatic epoxy resins include ethylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and 1,6- Hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, polyethylene glycol diglycidyl ether, etc. can be used, and also unsaturated such as butadiene epoxy resin and isoprene epoxy resin Fatty acid epoxy resins may also be used. The alicyclic epoxy resin is vinylcyclohexene monooxide, 1,2-epoxy-4-vinylcyclohexane, 1,2: 8,9-diepoxyrimonene, 3,4-epoxycyclohexenylmethyl-3 ' , 4'-epoxycyclohexene carboxylate and the like can be used.

For example, EBECRYL 600, 860, 3105, 3420, 3700, 3701, 3702, 3703, 3708, 6040 (manufactured by Daicel Cytech Co., Ltd.), Neopol 8101, 8250, 8260, 8270, 8355, 8351, 8335, 8414 , 8190, 8195, 8316, 8317, 8318, 8319, 8371 (made by Nippon Upica Co., Ltd.), Denacol acrylate DA212, 250, 314, 721, 722, DM201 (Nagase Chemtex Co., Ltd.) (Made by Nagase Chemtex Corporation), night beam (made by Harima Chemicals Inc.), Miramer PE210, PE230, EA2280 (made by Toyo Chemicals Co., Ltd.), etc. are mentioned.

A urethane (meth) acrylate is a reactant which has a urethane skeleton in the center by which the (meth) acryl monomer, polyfunctional isocyanate, and polyhydric alcohol which have a hydroxyl group react. As a (meth) acryl monomer which has a hydroxyl group, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, etc. are mentioned. As polyfunctional isocyanates, tolylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, trimethylolpropane tolylene diisocyanate, diphenylmethane tri Isocyanate etc. are mentioned, Especially, the hexamethylene diisocyanate which is favorable in weather resistance is used suitably. As a polyhydric alcohol, what can be used for polyester (meth) acrylate can be used.

For example, EBECRYL 204, 210, 220, 230, 270, 4858, 8200, 8201, 8402, 8804, 8807, 9260, 9270, KRM8098, 7735, 8296 (manufactured by Daicel Cytech Co., Ltd.), UX2201, 2301, 3204, 3301, 4101, 6101, 7101, 8101, 0937 (made by Nippon Kayaku Co., Ltd.), UV6640B, 6100B, 3700B, 3500BA, 3520TL, 3200B, 3000B, 3310B, 3210EA, 7000B, 6630B, 7461TE (Nippon Synthetic Chemical Company (manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.), Eupica 8921, 8932, 8940, 8936, 8937, 8980, 8975, 8976 (manufactured by Nippon Yuka Corporation), Miramer PU240, PU340 (manufactured by Toyo Chemicals, Inc.) ), And the like.

Polyether (meth) acrylate is a reactant of polyether polyol and (meth) acrylic acid. Examples thereof include ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, and EBECRYL 81 (manufactured by Daicel Cytech Co., Ltd.).

Among these acrylic oligomers, the use of polyester (meth) acrylate, epoxy (meth) acrylate and urethane (meth) acrylate is preferable. When the number of functional groups is 3 or less, the curing shrinkage of the cured product when the adhesive composition is cured with an active energy ray can be reduced, and the glass transition temperature of the cured product can be reduced, and the cholesteric resin layer and the transparent film Good adhesion can be maintained.

(B) Mono (meth) acrylate which has at least 1 hydroxyl group whose viscosity in temperature 20 +/- 1.0 degreeC is 10 mPa * s or more and less than 500 mPa * s.

The viscosity in temperature 20 +/- 1.0 degreeC is 10 mPa * s or more and less than 500 mPa * s means that the measured value of a viscosity satisfy | fills 10 mPa * s or more and less than 500 mPa * s at least 1 point in the range of temperature conditions. Specific examples of the mono (meth) acrylate having at least one hydroxyl group having a viscosity of at least 10 mPa · s and less than 500 mPa · s at a temperature of 20 ± 1.0 ° C used in the present invention include 2-hydroxypropyl acrylate (10.9 mPa? s), 4-hydroxybutyl acrylate (17 mPa? s), 2-hydroxy-3-phenoxypropyl acrylate (373 mPa? s), glycerin monomethacrylate: Blemmer GLM (150 mPa? s , Nichiyu Corporation (NOF Corporation), polyethylene glycol monomethacrylate: Blemmer PE-90 (15mPa? S, Nichiyu Corporation), PE-200 (30mPa? S, Nichiyu Corporation), PE-350 (45mPa s, product made by Nichi Oil Corp., polypropylene glycol monomethacrylate: Blemmer PP-1000 (product made by Nichi Oil Corp.), PP-500 (75 mPa Oil, Nichi Oil Corp.), poly (ethylene propylene glycol) Monomethacrylate: Blemmer 50 PEP-300 (55mPa? S, Nichiyu Corporation), polyethylene glycol polypropylene glycol monomethacrylate: blem 70 PEP-350B (79mPa? S, Nichiyu Corp.), Propylene Glycol Polybutylene Glycol Monomethacrylate: Blemmer 10 PPB-500B (48 mPa? S, Nichiyu Corp.), Polyethylene Glycol Monoacrylate: Blemmer AE-200 (15 mPa? S, manufactured by Nichi Oil Corp.), polypropylene glycol monoacrylate: Blemmer AP-400 (48 mPa? S, manufactured by Nichi Oil Corp.), aliphatic epoxy acrylate: EBECRYL 112 (55 mPa? S, Daicel Co., Ltd.) Tech), PA500 (71.8 mPa * s, Toho Chemical Industry Co., Ltd. product), etc. are mentioned.

The use of mono (meth) acrylate having at least one hydroxyl group having a viscosity of at least 10 mPa · s and less than 500 mPa · s is preferable since the coating titration of the adhesive composition is good and the adhesive layer exhibits stronger adhesive force. The viscosity range is more preferably 50 mPa · s or more and 400 mPa · s or less, and still more preferably 70 mPa · s or more and 350 mPa · s or less.

It is preferable that mono (meth) acrylate of (B) is 35 weight part or more and 85 weight part or less in 100 weight part of (meth) acrylates contained in the adhesive composition of an uncured state. By being in this range, firmer adhesive force is obtained.

(Other ingredients)

The adhesive composition may contain a polymerization initiator, a crosslinking agent, an inorganic filler, a polymerization inhibitor, a coloring pigment, a dye, an antifoaming agent, a leveling agent, a dispersing agent, a light diffusing agent, a plasticizer, and an antistatic agent in a range that does not impair the effects of the present invention as necessary. It is also possible to include surfactants, non-reactive polymers (inert polymers), viscosity modifiers, near-infrared absorbers, adhesion promoters and the like.

As a polymerization initiator, it can select suitably according to the kind of active energy ray.

When photocuring, one or more types of photoinitiators can be used. Moreover, a photosensitizer can be used arbitrarily.

As a photoinitiator, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methyl Propane-1-one, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethyl thioxanthone, methylbenzoylformate, 2,2-diethoxyacetophenone, β -Ionone, β-bromosstyrene, diazoaminobenzene, α-amylcinnacaldehyde, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, p, p ′ -Dichlorobenzophenone, p, p'-bisdiethylaminobenzophenone, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin n-butyl ether, diphenyl sulfide, bis (2 , 6-methoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, bis (2,4,6-trimethylbene Crude) -phenylphosphine oxide, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butan-1-one, anthracenebenzophenone, α-chloroanthraquinone, diphenyldisulfide, hexachlorobutadiene, pentachlorobutadiene, octachlorobutene, 1-chloromethylnaphthalene, 1 , 2-Octane ion, 1- [4- (phenylthio)-, 2- (o-benzoyl)] oxime, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole -3-yl] ethanone 1- (o-acetyloxime), (4-methylphenyl) [4- (2-methylpropyl) phenyl] iodonium hexafluorophosphate, 3-methyl-2-butynyltetramethyl Sulfonium hexafluoroantimonate, diphenyl- (p-phenylthiophenyl) sulfonium hexafluoroantimonate, and the like.

As for the quantity (addition part) of a photoinitiator, 0.5 weight part or more and 10 weight part or less are preferable with respect to 100 weight part of (meth) acrylates contained in the adhesive composition of an uncured state, More preferably, it is 1 weight part or more It is the range of 5 weight part or less.

As the photosensitizer, for example, n-butylamine, triethylamine, poly-n-butylphosphine or the like may be added to control the curability.

As antifoaming agent, BYK051, 052, 055, 057, 1790, 065, 070, 088, 354, 392 made by BIK-Chemie Japan KK, LR-20R made by Nippon Oil Corporation (NOF Corporation), OP-80R , OP-83RAT, OP-85R, PP-40R, SO-80R, SP-60R, BP-70R, CP-08R, DS-60HN and the like.

The antifoamer can be added to such an extent that the adhesive force of an adhesive layer does not fall, and 0.1 weight part or more and 1.0 weight part or less are preferable with respect to the adhesive composition solid content of an uncured state, More preferably, it is 0.1 weight part or more and 0.5 weight part It is as follows.

As a crosslinking agent, the bifunctional or more (meth) acrylate monomer of less than 500 molecular weight can be mixed.

Specifically, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloxy Propyl methacrylate, tetraethylene diacrylate, polyethylene glycol # 400 diacrylate, tricyclodecane dimethanol di (meth) acrylate, dipentaerythritol hexaacrylate, 1,6-hexanediol di ( Meth) acrylate, hydroxypivanerine neopentyl glycol diacrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol triacrylate, penta Erythritol tetraacrylate, trimethylolpropane tri (meth) acrylate , Ditrimethylolpropane tetraacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol dimethacryl Elate, ethoxylated bisphenol A dimethacrylate, etc. are mentioned.

The amount (addition portion) of the crosslinking agent is preferably 0.5 parts by weight or more and 10 parts by weight or less, more preferably 1 part by weight or more, based on 100 parts by weight of the (meth) acrylate contained in the uncured adhesive composition. It is 5 parts weight or less. If it mixes more than 10 weight part, hardening of an adhesive layer will advance too much and the adhesive force with a cholesteric resin layer and a transparent film will fall. If it is less than 0.5 weight part, the effect of a crosslinking agent will not express.

As a viscosity modifier, the slurry which disperse | distributed the metal oxide nanoparticle of several nm-several hundred nm in the solvent can be used.

Examples of the metal oxides include silica, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, and mixtures thereof. For example, organosilica sol methanol silica sol, IPA-ST, IPA-ST-UP, IPA-ST-ZL, EG-ST, NPC-ST-30, DMAC-ST manufactured by Nissan Chemicals Industries, Ltd. , MEK-ST, MIBK-ST, XBA-ST, PMA-ST, PGM-ST, PL-1-IPA, PL-1-TOL, PL-2L-, manufactured by Fuso Chemical Co., Ltd. PGME, PL-2L-MEK, etc. are mentioned.

The range of preferable amount (addition part) is 1-15 weight part with metal oxide solid content with respect to 100 weight part of (meth) acrylates contained in the uncured adhesive composition, More preferably, it is 5-10 weight part to be. When less than 1 weight part, an effect is not seen, and when more than 15 weight part, the fall of adhesive force is seen.

The light diffusing agent is a particle having a property of diffusing light, and can be roughly classified into an inorganic filler and an organic filler. Examples of the inorganic fillers include glass, silica, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, and mixtures thereof. Examples of the organic fillers include acrylic resins, polyurethane resins, polyvinyl chloride resins, polystyrene resins, polyacrylonitrile resins, polyamide resins, polysiloxane resins, melamine resins, benzoguanamine resins, fluorine resins, polycarbonate resins, Silicone resins, polyethylene resins, ethylene-vinyl acetate copolymers, acrylonitrile, and crosslinked products thereof. Among these, as an organic filler, microparticles | fine-particles which consist of an acrylic resin, a polystyrene resin, a polysiloxane resin, and these crosslinked material are preferable at the point which has high dispersibility, high heat resistance, and coloring (yellowing) at the time of shaping | molding. Among these, the fine particle which consists of a crosslinked material of acrylic resin is more preferable at the point which is more excellent in transparency. Moreover, what consists of two or more types of raw materials may be used as a light diffusing agent, and you may mix and use two or more types of light diffusing agents.

The amount (addition portion) of the light diffusing agent is preferably 0.5 to 20 parts by weight based on 100 parts by weight of the solid content contained in the uncured adhesive composition. The amount (addition portion) of the light diffusing agent is a value determined by a desired haze value and the film thickness of the adhesive layer.

Inert polymer means inert to polymerization hardening by active energy ray, and when the film thickness is designed to 5 micrometers or more in order to add a light-diffusion agent and achieve a desired haze value, and the total thickness of a brightness improving film When designing the film thickness of an adhesive layer to 5 micrometers or more in order to make desired thickness, it can add in order to maintain the film thickness of an adhesive layer stably in the state of unpolymerization. As glass transition temperature of an inert polymer, -10 degreeC or more and 80 degrees C or less are preferable, and -5 degreeC or more and 50 degrees C or less are more preferable. By setting it as this glass transition temperature, the adhesive force after polymerization hardening can be maintained.

Specific examples of the inert polymer include urethane resin, methyl methacrylate polymer, styrene polymer, polyacrylonitrile, polyvinyl chloride, polyvinyl acetate, polyester, polycarbonate resin, triacetylcellulose resin, butyral resin, The random copolymer which copolymerized 2 or more types of these, the block copolymer, the graft copolymer which grafted the molecule | numerator which has carboxylic acid, sulfonic acid, those ester, hydroxyl group, and mercapto group in the side chain, etc. are mentioned. The amount (addition part) of the inert polymer is preferably 20 parts by weight or more and 70 parts by weight or less, more preferably 30 parts by weight or more and 60 parts by weight or less in 100 parts by weight of the solid content contained in the uncured adhesive composition. to be. When the thickness is less than 20 parts by weight, when the thickness of the adhesive layer is designed to be 5 µm or more, since the viscosity of the adhesive layer is low in the uncured state, the film thickness is not stabilized, and the fluctuation of the film thickness becomes large, and the diffusion agent is mixed. The haze value is not stable. When more than 60 weight part, the adhesive layer film hardness in an uncured state will become high, and mixing of air bubbles will become frequent at the time of joining.

As an adhesion agent, the monomer of a dual cure type can be used suitably. For example, Laromer (made by BASF Japan), Karenz MOI, AOI, BEI (made by Showa Denko K.K.), etc. can be used.

The amount (addition) of the adhesion agent is preferably 1 part by weight or more and 30 parts by weight or less, more preferably 5 parts by weight or more and 20 parts by weight, in 100 parts by weight of the solid content contained in the uncured adhesive composition. It is as follows.

As a coating method on the cholesteric resin layer or the transparent film of the adhesive composition used for this invention, dies, such as a roll coating method, a curtain coating method, a slot coating method, which are coating means to the continuous film currently performed, are generally performed A coating method, a spray coating method, etc. can be used and it is not specifically limited. The thickness of the adhesive composition to be applied is usually 0.5 µm or more and 100 µm or less, preferably 1 µm or more and 50 µm or less. If the thickness is too thick, curing speed of the adhesive composition decreases, and curing may be insufficient. It is not preferable because the adhesive force is insufficient.

In bonding of a cholesteric resin layer and a transparent film after apply | coating an adhesive composition, although it can carry out by the laminating means generally performed, air bubbles mixed at the time of bonding are thoroughly removed. In the continuous lamination treatment, the narrowing pressure between the lamination roll and the mating roll is increased, the lamination processing speed is decreased, and in the batch lamination treatment, the surface pressure is increased, by employing a method such as vacuum pressurization. And mixing of bubbles at the time of bonding can be suppressed. Hardening of the contact bonding layer after application | coating and bonding can be performed by irradiating an ultraviolet-ray or an electron beam uniformly to the width direction of a long bonding film by suitable conditions according to the adhesive composition to be used.

2. Polarizing plate and liquid crystal display device of the present invention

The polarizing plate and liquid crystal display device of this invention are equipped with the brightness improving film of the said this invention. As a preferable aspect, the liquid crystal display device of this invention has the polarizing plate of the said invention containing the brightness improving film of the said invention. The polarizing plate in this case can provide a transparent protective film further. As the transparent protective film, a resin such as a protective film for protecting the cholesteric resin layer can be used, and among these, polymethyl methacrylate and triacetyl cellulose are preferable, and the durability and display performance of the display device are improved. From the viewpoint which can be made, it is especially preferable that it is polymethylmethacrylate. Moreover, as a transparent material which is a material of a transparent protective film, it is preferable that it is a thermoplastic resin.

As polymethyl methacrylate, Homopolymers of alkyl methacrylate esters, such as methyl methacrylate and ethyl methacrylate; Or a copolymer of an alkyl methacrylate with a vinyl monomer having an unsaturated bond such as styrene, vinyl acetate, α, β-monoethylenically unsaturated carboxylic acid, vinyltoluene, or α-methylstyrene. Only 1 type may be used among these and 2 or more types may be combined. It is preferable that the said polymethyl methacrylate is the range whose glass transition temperature is 80-120 degreeC. In addition, polymethyl methacrylate has a high surface hardness when molded into a film, specifically, pencil hardness (according to JIS K 5600-5-4, except that the test load is 500 g). It is preferable to exceed.

The resin constituting the transparent protective film is a total light transmittance of 80% or more in a 1 mm thick plate, for example, like the resin constituting the protective film for protecting the cholesteric resin layer, preferably 85% or more, more preferably It can use 90% or more.

The water vapor transmission rate in 100 micrometers of said transparent protective film is 20-500g / m <^2> -24h normally, Preferably it is 50-200g / m <^2> -24h, More preferably, it is 120-170g / m <^2> -24h.

Thickness of the said transparent protective film becomes like this. Preferably it is 100 micrometers or less, More preferably, they are 1 micrometer or more and 60 micrometers or less, More preferably, they are 5 micrometers or more and 40 micrometers or less. By making thickness into the said range, thickness reduction of a polarizing plate and a display apparatus can be aimed at.

Although the method of integrating the said polarizing plate and the said transparent protective film is not specifically limited, For example, the method of plasma-processing on these surfaces, and then crimping | bonding them, the method of laminating | stacking through an adhesive layer or an adhesive layer, etc. are mentioned. In this case, although an adhesive and an adhesive agent can also be directly apply | coated at the time of lamination | stacking, after apply | coating an adhesive agent or an adhesive agent on a separator, it can also laminate | stack and peel an separator, and an adhesive layer or an adhesive layer can also be formed.

In the polarizing plate of the present invention, a transparent protective film may be provided on both sides of the polarizer, and the brightness enhancing film of the present invention may be bonded to one side thereof (see the embodiment of FIG. 3), and a transparent protective film is provided on one side of the polarizer, The brightness improving film of this invention can also be bonded by the other surface (refer to embodiment of FIG. 4). In an embodiment in which the transparent protective film is provided only on one side of the polarizer and the brightness enhancement film is provided on one side, the polarizer can be protected by a small number of films, and the display device can be thinned.

In a preferable aspect of the liquid crystal display device of the present invention, the polarizing plate included in the composite laminate (also called a composite) is combined with a liquid crystal cell and another polarizing plate to form a laminate called a polarizing plate-liquid crystal cell-polarizing plate. By constructing the structure, the display of the image is controlled thereby.

Specifically, for example, the polarizing plate included in the composite is a first polarizing plate, and the liquid crystal cell is sandwiched between the first polarizing plate and the second polarizing plate of another layer. Thus, it can be assembled to a display apparatus by making a 1st polarizing plate oppose a liquid crystal cell as a light source side (namely, lighting apparatus side), and a 2nd polarizing plate as a display surface side.

The material of the polarizer (2nd polarizer) with which this 2nd polarizing plate is equipped is not specifically limited, The same thing as the polarizer (1st polarizer) with which a 1st polarizing plate is equipped can be used. A liquid crystal cell is not specifically limited, What can be used in a known liquid crystal display device can be selected suitably. Specifically, the liquid crystal cell of various systems in which the polarized light transmitted through the first polarizer is controlled by the liquid crystal cell so as to pass through the second polarizer and exit from the display surface or not exit, and as a result, an image is displayed on the display surface; Polarizer can be used. As a driving method of the liquid crystal cell, for example, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, HAN (Hybrid Alignment Nematic) type, IPS (In Plane Switching) type, VA (Vertical Alignment) type, MVA (Multiple) Vertical alignment type, OCB (Optical Compensated Bend) type, etc. are mentioned.

The liquid crystal display device of the present invention may further include a backlight as a lighting device, and may have a configuration in which a brightness enhancement film is disposed between the backlight and the liquid crystal cell. More specifically, the brightness improvement film of this invention can be arrange | positioned so that a cholesteric resin layer may be a backlight side rather than (lambda) / 4 board, between a backlight of a liquid crystal display device, and a liquid crystal cell, and brightness improvement can be achieved.

The use of the liquid crystal display device of the present invention is not particularly limited, and can be used as a television, a display device for a computer, and a display device for other electronic devices. In particular, it can use suitably for the application which requires high display quality in a wide viewing angle.

Example

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated further more concretely based on an Example. In addition, this invention is not limited to a following example. In the following, "part" and "%" regarding the amount ratio of components represent parts by weight and% by weight unless otherwise specified. In addition, the evaluation method of the produced brightness improvement film and the measuring method of the viscosity of an adhesive agent followed the following method.

(Evaluation method of brightness improvement film)

(i.The coatability of the adhesive)

Five steps of evaluation were made by visually observing the method of wet spreading immediately after application to the coating substrate, the occurrence of coating frying after drying, and the disorder of the membrane surface due to lack of viscosity.

Evaluation 5: excellent coatability

Evaluation 4: slightly superior coatability

Evaluation 3: coating property is normal

Evaluation 2: slightly inferior coatability

Evaluation 1: Poor Coating

(ii.Measurement of Surface Hardness of Brightness Enhancement Film)

It carried out based on the JIS K 5600-5-4 scratch-hardness test method except having made the load 500g, the scanning distance 30mm, and the host speed 20mm / min. The hardness of the cholesteric resin layer surface of the brightness improving film was measured.

(iii. Adhesion between cholesteric resin layer and λ / 4 plate)

Notch was evaluated on the cholesteric resin layer surface of a brightness improving film based on JISK5600-5-6 crosscut method.

Evaluation 5: Small peeling of the coating film at the intersection of cuts.

Evaluation 4: The coating film is peeling off along the edge of a cut and / or at an intersection point.

Evaluation 3: Depending on the edge of a cut, a coating film is causing the big peeling partially or fully, and / or the various parts of an eye are peeling partially or fully.

Evaluation 2: Depending on the edge of a cut, a coating film has produced large peeling partially or fully, and / or several eye peels partially or fully.

Evaluation 1: When degree of peeling exceeds evaluation 2.

(Measurement of viscosity)

It measured with the vibration type viscometer (a tuning fork type vibration type viscometer SV-10 by A & D Company Limited).

&Lt; Example 1 >

(i. Production of Substrate-Cholesteric Resin Layered Layer)

Corona discharge treatment was performed on one surface of the sheet-like base material (trade name "Zeonor ZF14-100", manufactured by Nippon Zeon Corporation) so that the wetness index would be 56 mN / m. Polyvinyl alcohol (brand name "Poval PVA203", Kuraray Co., Ltd. product) was apply | coated to this corona discharge treated surface with the # 2 bar coater, it dried at 120 degreeC for 5 minutes, A dry film having a thickness of 0.2 µm was produced. The base material which has an oriented film was obtained by rubbing this dry film in 1 direction.

29.1 parts of rod-shaped liquid crystalline compounds (compound represented by the following formula (C3)), 7.28 parts of compound represented by the following formula (C4), a photoinitiator (Ciba Specialty Chemical Corporation, product name, "IRG907" ) 1.20 parts, 2.22 parts of a chiral agent (trade name "LC756" by BASF Corporation), 0.04 parts of surfactant KH40 (manufactured by Seimi Chemical Co., Ltd.), and 60.00 parts of 2-butanone (solvent) It mixed and prepared the cholesteric liquid crystal composition.

This cholesteric liquid crystal composition was apply | coated to the surface which has the orientation film of the base material which has the orientation film prepared above by die coating. After the coating film is subjected to the orientation treatment at 100 ° C. for 5 minutes, and repeating the process consisting of the irradiation treatment of the weak ultraviolet rays of 0.1 to 45 mJ / cm ² with respect to the coating film and the subsequent heat treatment at 100 ° C. for 1 minute, The ultraviolet-ray of 800mJ / cm <^2> was irradiated under nitrogen atmosphere, the cholesteric resin layer with a dry film thickness of 5.3 micrometers was formed, and the base material-cholesteric resin layer laminated body was obtained.

(ii. Preparation of 1/4 Wavelength Plate)

The monomer composition which consists of 97.8 weight% of methyl methacrylate and 2.2 weight% of methyl acrylate was polymerized by the bulk polymerization method, and the resin pellet was obtained.

Rubber particles were prepared according to Example 3 of Japanese Patent Application Laid-Open No. 1980-27576. This rubber particle has a spherical three-layer structure, and the inner layer is a crosslinked polymer of methyl methacrylate and a small amount of allyl methacrylate, and the inner layer contains butyl acrylate, styrene and a small amount of allyl acrylate as main components. It is a soft elastic copolymer crosslinked and the outer layer is a hard polymer of methyl methacrylate and a small amount of ethyl acrylate. Moreover, the average particle diameter of the inner layer was 0.19 micrometer, and the particle diameter which included the outer layer was 0.22 micrometer.

70 parts of the resin pellets and 30 parts of the rubber particles were mixed and melt kneaded with a twin screw extruder to obtain methacrylic acid ester polymer composition A (glass transition temperature 105 ° C.).

The methacrylic acid ester polymer composition A (b layer) and the styrene maleic anhydride copolymer (glass transition temperature 130 ° C.) (a layer) were coextruded at a temperature of 280 ° C. A multilayer film was obtained having a three-layer structure, each layer having an average thickness of 45-70-45 (µm). This multilayer film was tenter uniaxially stretched by extending | stretching temperature 128 degreeC, draw ratio 1.4 time, and drawing speed 10m / min, and the quarter wave plate which is a stretched multilayer film was obtained. Furthermore, one side of this quarter wave plate was subjected to corona discharge treatment so that the wetness index was 56 dyne / cm.

As for the retardation value in wavelength 550nm of the obtained quarter wave plate, the retardation Rth of the thickness direction was -118 nm, and the retardation Re of the in-plane direction was 140 nm.

(iii. Production of Substrate-Cholesteric Resin Layer-Adhesive Layer Laminate)

As an oligomer-type polyfunctional (meth) acrylate, urethane acrylate (brand name "UV-7000B", the Nippon Synthetic Chemical Co., Ltd. product, 2-3 functional groups) 54.5 parts, 2-hydroxy-3 as (meth) acrylate -36.4 parts of phenoxypropyl acrylate (trade name "DA141", manufactured by Nagase Chemical Co., Ltd., viscosity 373 mPa? S), 9.1 parts of 4-hydroxybutyl acrylate, 17.8 parts of methyl ethyl ketone, and 0.9 part of a photoinitiator as other acrylates. The cholesteric resin layer surface which produced the adhesive liquid which mixed (dissolved brand name "IRGACURE 651", the product made by Chiba-Speciality Chemicals Co., Ltd.) by said (i. The base material-cholesteric resin layer which apply | coated using # 6 bar to the corona discharge treated surface which processed (processing conditions: 150 W * min / m <^2> ), dried at 65 degreeC for 1 minute, and has an adhesive layer of 3.4 micrometers in film thickness. -The laminated body of the adhesive layer was manufactured.

(iv. Production of Brightness Enhancement Film)

The adhesive layer of the corona discharge process surface of the quarter wave plate obtained by said (ii. Manufacture of a quarter wave plate), and the laminated body obtained by said (iii. Base material-cholesteric resin layer-adhesive layer laminated body) The side surface was piled up and it bonded by the laminator at the speed of 0.5 m / min, and the pinching pressure of 0.3-0.4 MPa. UV irradiation (Large UV irradiation apparatus, metal halide lamp, irradiation time 12s, laminated light quantity 1200J / cm <^{2> made} by Nippon Battery Co., Ltd.) is performed from the 1/4 wavelength plate side of this laminated body, and an adhesive layer Was cured.

Subsequently, the base material was peeled from the laminated body, and the brightness improving film 1 which has a laminated constitution of a quarter wave plate-adhesive layer-cholesteric resin layer was obtained. Table 1 shows the results of the evaluation of the brightness enhancement film 1.

<Example 2>

18.2 parts of urethane acrylates (brand name "UV-7000B", the Nippon Synthetic Chemicals company make) as an oligomer type polyfunctional (meth) acrylate, and 2-hydroxy-3- phenoxypropyl acrylate as (meth) acrylates (Brand name "DA141", product made by Nagase Chemical Co., Ltd., viscosity 373 mPa * s) Except having changed the ratio to 72.7 parts, it carried out similarly to Example 1, and obtained the brightness improving film 2. Table 1 shows the results of the evaluation of the brightness enhancement film 2.

<Example 3>

The brightness improvement film 3 was obtained like Example 2 except having changed the (meth) acrylate into 72.7 parts of monohydroxyalkyl acrylate (brand name "PA500", the Toho Chemical company make, viscosity 71.8 mPa * s). . Table 1 shows the results of the evaluation of the brightness enhancement film 3.

<Example 4>

Except for changing the oligomer-type polyfunctional (meth) acrylate to 54.5 parts of an epoxy acrylate (trade name "Ebecryl EB3708", manufactured by Daicel Cytech Co., Ltd., functional groups 2), it was carried out similarly to Example 1, and the brightness improving film 4 was obtained. Table 1 shows the results of the evaluation of the brightness enhancement film 4.

Example 5

72.7 parts of 2-hydroxy-3-phenoxypropyl acrylates as urethane acrylate (brand name "UV-7000B", the Nippon Synthetic Chemical Co., Ltd. product, functional groups 2-3) and (meth) acrylate As a brand name "DA141", the Nagase Chemical Co., Ltd., viscosity 373 mPa? S) and other acrylates, 9.1 parts of 4-hydroxybutyl acrylate, 71.9 parts of methyl ethyl ketone, a photoinitiator (brand name "DAROCURE TPO", Chiba? Specialty chemicals) 2.7 parts, 332.2 parts of urethane resins (trade name "UREARNO 242", Arakawa Chemical Industries, Ltd.) as an inert polymer, and crosslinked polystyrene particles (brand name "SX130H", Soken Chemical Co., Ltd.) Soken Chemical Engineering Co., Ltd.) 13.8 parts of the adhesive liquid which mixed, melt | dissolved, and disperse | distributed the cholesteric resin layer surface manufactured by said (i. Manufacture of base material-cholesteric resin layer laminated body) the corona discharge Treatment (treatment condition: 150 W? Min / m ^It applied to the corona discharge process surface which performed ² ) using a blade, and dried at 65 degreeC for 2 minutes, and produced the laminated body of the base material-cholesteric resin layer-adhesive layer which has an adhesive layer of film thickness of 10.5 micrometers. The subsequent steps were performed in the same manner as in Example 1 to obtain a brightness improving film 5. Table 1 shows the evaluation results of the brightness enhancement film 5.

<Example 6>

(v. Preparation of Diffusion Agent Mixed Adhesive Layer)

To polyethylene terephthalate separator (brand name "PET50AL", product made by Lintec Corporation), base resin (brand name "SK dyne 2094", Soken Chemical Co., Ltd. product, acrylic acid ester copolymer, solid content fraction 25%, solvent : 400 parts of ethyl acetate / 2-butanone = 93/7), 1.1 parts of a polyfunctional epoxy crosslinking agent (trade name "E-AX", manufactured by Soken Chemical Co., Ltd.) and fine powder (trade name "Kemisuno MX300", Soken Chemical Co., Ltd.) 1) The adhesive composition which has a composition which consists of 4.3 parts is apply | coated using die coating, it is made to dry at 100 degreeC for 2 minutes, the adhesion layer of 20 micrometers in thickness is formed, and the laminated body which has a laminated constitution of a separator diffusion adhesion layer is obtained. Obtained.

(vi. Production of liquid crystal display device)

The diffusion adhesion layer of the separator diffusion adhesion layer laminate manufactured in the above (v) was bonded to the quarter-wave plate side of the brightness enhancement film 1 prepared in Example 1, the separator was peeled off, and the zeonor film was further removed. (Brand name "ZF14-100", the product made by Nippon Xeon Co., Ltd.) was bonded together, and the diffusion adhesion layer of the separator diffusion adhesion layer laminate manufactured in the above (v) was bonded to the surface of the cholesteric resin layer side, and the separator was The zeolite film (brand name "ZF14-100", the Nippon Xeon Co., Ltd. product) was bonded each other, and the brightness improvement film 6 was manufactured.

The brightness enhancement film 6 was installed on the prism sheet of the liquid crystal monitor LCD-DTV191X (sheet structure: diffusion sheet / prism sheet) by IO DATA DEVICE (IO DATA DEVICE, INC.), And it observed by the back display. The glare of the prism sheet origin was not seen, neither the floating of the cholesteric resin layer was seen, and the brightness was a uniform display state.

<Example 7>

(vii.Method for Producing Transparent Adhesive Layer)

In the same separator used in the above (v), a die-coating mixture of 400 parts of a base resin (brand name "SK Dyne 2094") and 1.1 parts of a crosslinking agent (brand name "E-AX", Soken Chemical Co., Ltd., multifunctional epoxy crosslinking agent) It applied, it dried at 100 degreeC for 2 minutes, the adhesion layer of 20 micrometers in thickness was formed, and the laminated body which has a laminated constitution of a separator adhesion layer was obtained.

(viii. Manufacture of liquid crystal display device)

The corona treatment was performed to the wetness index 56 dyne / cm of the 1/4 wavelength plate side of the brightness improving film 1 manufactured in Example 1, the adhesion layer of the separator adhesion layer laminated body manufactured in (vii) was bonded, and a separator Was peeled off, it bonded to one side of the polarizing plate with which the protective film was stuck on both surfaces of the polarizer, and the laminated body (polarizing plate laminated body 1) was manufactured.

The light source side polarizing plate of the liquid crystal panel of the liquid crystal monitor LCD-DTV191X made by IO DATA Corporation was peeled off, it bonded together so that the brightness improving film side of the manufactured polarizing plate laminated body 1 may face to the light source side, and it installed again, and observed with the white display.

There was no point defect in the surface and the cholesteric resin layer was lifted, and the brightness was a uniform display state.

<Example 8>

(ix. Manufacture of Liquid Crystal Display)

The corona treatment was performed so that the surface of the 1/4 wavelength plate side of the brightness improvement film 1 manufactured in Example 1 may be set to a wetness index of 56 dyne / cm, and PVA (brand name "Gohsefimer Z200", the Nippon Synthetic Chemical company make) PVA adhesive liquid consisting of 3.0 parts, 0.05 parts of glyoxal (trade name "Glyoxal", manufactured by Nippon Synthetic Chemicals Co., Ltd.) and 97.0 parts of pure water is applied immediately to # 8, and another polarizer with a protective film adhered to one side of the polarizer. It bonded to the surface and dried at 100 degreeC for 2 minutes, and obtained the laminated body.

The light source side polarizing plate of the liquid crystal panel of the liquid crystal monitor LCD-DTV191X by IO DATA Corporation was peeled off, it bonded together so that the brightness improving film side of the laminated body manufactured above could be directed to the light source side, and it observed again by the white display.

There was no point defect in the surface and the cholesteric resin layer was lifted, and the brightness was a uniform display state.

Example 9

(x. Production of Brightness Enhancement Film)

The corona treatment was performed so that the one-side wetness index of the quarter wave plate manufactured in (ii) was 56 dyne / cm, the diffusion adhesive layer prepared in (v) was bonded and the separator was peeled off, and the prepared in (i) The cholesteric resin layer of the laminated body was corona-treated (processing conditions: 150 Wmin / m <^2> ), it bonded with the diffusion adhesion layer, and the base material was peeled off.

Corona treatment (treatment condition: 150W? Min / m ² ) on the surface on the side opposite to the surface in contact with the diffusion adhesive layer of the cholesteric resin layer, and the adhesive liquid used in Example 1 in the same manner as in Example 1 Coating and drying yielded an adhesive layer-cholesteric resin layer-diffusion adhesive layer-1 / 4 wave plate laminate.

As a transparent film, a corona treatment was performed on the zeolite film (trade name "ZF14-100", manufactured by Nippon Xeon Co., Ltd.) so that the wetness index was 56 dyne / cm, and the adhesive layer of the laminate obtained in (x) was used as Example 1 and It bonded together and UV irradiation and hardened the contact bonding layer.

Moreover, the diffusion adhesion layer of the separator diffusion adhesion layer laminated body manufactured by said (v) was bonded to the 1/4 wavelength plate side, the separator is peeled off, and further, a zeolite film (brand name "ZF14-100", Nippon Xeon ( Co., Ltd.) was bonded together, and the brightness improvement film 7 of the zeolite film-diffusion adhesion layer-1 / 4 wavelength plate-diffusion adhesion layer-cholesteric resin layer-adhesive layer-genono film was manufactured.

(xi.Manufacture of Liquid Crystal Display Device)

The brightness enhancement film 7 was installed on the prism sheet of the liquid crystal monitor LCD-DTV191X (sheet structure: diffusion sheet / prism sheet) made from IO DATA, and it observed with the back display.

No glare attributable to the prism sheet was seen, and no wave of the brightness enhancement film 2 due to heat at the time of backlight lighting was seen, and the brightness was a uniform display state.

(xii. Preparation of Brightness Enhancing Film for Comparison)

Comparative Example 1

(Meth) acrylate is 2-ethylhexyl acrylate (brand name "NK oligo EA5120", the product made by Shin-Nakamura Chemical Co., Ltd.), viscosity 50.4 mPa * s, and a hydroxyl group in a molecule | numerator Except for changing to 72.7 parts, it carried out similarly to Example 2, and obtained the brightness improving film 8. Table 1 shows the evaluation results of the brightness enhancement film 8. When mono (meth) acrylate which does not have a hydroxyl group in a molecule | numerator was used, not only the adhesive force fell but also the wound | wound was seen in the cholesteric resin layer, and it turned out that the surface hardness of the cholesteric resin layer also falls.

Comparative Example 2

In the same manner as in Example 2, except that the oligomeric polyfunctional (meth) acrylate was changed to 18.2 parts of urethane acrylate (trade name "UV-7640B", manufactured by Nippon Synthetic Chemical Co., Ltd., 6 or more functional groups). Enhancement film 9 was obtained. Table 1 shows the results of the evaluation of the brightness enhancement film 9. When the number of functional groups of an oligomer type polyfunctional (meth) acrylate was 6 or more, it turned out that adhesive force is falling.

Comparative Example 3

The brightness improving film 10 was obtained like Example 2 except having changed the (meth) acrylate into 72.7 parts of HEA (2-hydroxyethyl acrylate, the Toho Chemical Co., Ltd., viscosity 9.0 mPa * s). When the viscosity of (meth) acrylate falls, coating titration deteriorates and it turned out that there exists a malfunction in manufacture of a brightness improving film.

<Comparative Example 4>

Example 2 except having replaced (meth) acrylate with 72.7 parts of acrylic acid modified | denatured product (brand name "DA212", Nagase ChemteX make, viscosity 1400 mPa * s) of 1, 6- hexanediol diglycidyl ether In this way, the brightness improving film 11 was obtained. Table 1 shows the results of the evaluation of the brightness enhancement film 11. When the viscosity of the mono (meth) acrylate which has a hydroxyl group in a molecule | numerator is more than an upper limit, it turned out that coating titration deteriorates and adhesiveness also deteriorates.

(xiii. Fabrication of Liquid Crystal Display for Comparison)

Comparative Example 5

Except having changed the brightness improving film into what was produced by the comparative example 1, the liquid crystal television was prepared like Example 6, and it observed by the white display.

Although no glare attributable to the prism sheet was seen, the cholesteric resin layer was lifted up.

Comparative Example 6

A liquid crystal monitor was prepared in the same manner as in Example 7 except that the brightness enhancement film was changed to that produced in Comparative Example 1, and the white display was observed.

Point defects, a wound, and the cholesteric resin layer were lifted in surface inside.

&Lt; Comparative Example 7 &

A liquid crystal monitor was prepared in the same manner as in Example 8 except that the brightness enhancement film was changed to that produced in Comparative Example 1, and the white display was observed.

Point defects, a wound, and the cholesteric resin layer were lifted in surface inside.

&Lt; Comparative Example 8 >

(xiv. Preparation of Brightness Enhancing Film for Comparison)

In the manufacturing method of (x), instead of coating and drying the adhesive liquid used in Example 1 on the cholesteric resin layer by the method similar to Example 1, the transparent adhesion layer of (vii) is bonded together, A laminate was prepared in the same manner as in Example 9 except that the separator was peeled off, and the zeolite film diffusion pressure-sensitive adhesive layer-1 / 4 wavelength plate-diffusion pressure-sensitive adhesive layer-cholesteric resin layer-transparent pressure-sensitive adhesive layer-zeonor film was prepared. The brightness enhancement film 12 was produced.

(xv. Fabrication of Optical Display for Comparison)

The brightness enhancement film 12 was installed on the prism sheet of the liquid crystal monitor LCD-DTV191X (sheet structure: diffusion sheet / prism sheet) made from IO DATA, and it observed with the back display.

Although the glare from the prism sheet origin was not seen, the wave of the brightness | luminance improvement film 3 by the heat at the time of backlight lighting was seen, and the in-plane distribution of color was seen.

1: transparent film
2: adhesive layer
3: cholesteric resin layer
4: coating equipment
5: polarizer protective film
6: polarizer
7: adhesion layer

Claims (10)

As a brightness improving film provided with the transparent film in the at least one surface of the resin layer which has cholesteric regularity through an active energy ray hardening-type adhesive layer,
The active energy ray-curable adhesive layer is made by curing an active energy ray-curable adhesive composition,
With the adhesive composition uncured
(A) an oligomeric polyfunctional (meth) acrylate having 3 or less functional groups, and
(B) Mono (meth) acrylate which has at least one hydroxyl group in the molecule whose viscosity in temperature 20 +/- 1.0 degreeC is 10 mPa * s or more and less than 500 mPa * s.
A brightness enhancement film comprising at least. The method of claim 1,
The brightness improving film whose content rate of (B) is in the range of 35-85 weight part with respect to 100 weight part of (meth) acrylates contained in the uncured adhesive composition. The method of claim 1,
The brightness improving film whose (A) is 1 or more types of oligomeric (meth) acrylates chosen from the group which consists of urethane (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate. The method of claim 1,
The uncured adhesive composition further
(C) Inert polymer whose glass transition temperature is -10 degreeC or more and 80 degrees C or less.
A brightness enhancement film comprising a. The method of claim 1,
The brightness improving film whose transparent film is (lambda) / 4 plate. A transparent protective film is provided on both surfaces of a polarizer, and the brightness improving film of Claim 1 was bonded to one surface, The polarizing plate characterized by the above-mentioned. A transparent protective film is provided on one surface of a polarizer, and the brightness improving film of Claim 1 was bonded to the other surface, The polarizing plate characterized by the above-mentioned. The liquid crystal display device provided with the brightness improving film of Claim 1. The liquid crystal display device which bonded the polarizing plate of Claim 6 to the illuminating device side of a liquid crystal cell. The liquid crystal display device which bonded the polarizing plate of Claim 7 to the illuminating device side of a liquid crystal cell.

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