JP6009387B2 - Retardation film, production method of retardation film, polarizing plate and liquid crystal display device - Google Patents

Description

  The present invention relates to a retardation film. Moreover, it is related with the manufacturing method of retardation film. Furthermore, it is related with the polarizing plate and liquid crystal display device which used the said retardation film.

  Conventionally, a film having a retardation layer in which a liquid crystal compound is aligned and fixed has been widely studied. The retardation layer in which such a liquid crystal compound is aligned and fixed is usually formed by forming an alignment layer on a support and coating the liquid crystal compound on the surface of the alignment layer. For example, Patent Document 1 contains a transparent substrate made of a cycloolefin resin, a polymer of a polymerizable monomer having a predetermined polymerizable group formed so as to be in contact with the transparent substrate, and a liquid crystal material. An adhesive alignment layer having an alignment regulating force for homeotropic alignment, and a refractive index nx in any x direction and y direction formed on the adhesive alignment layer and containing a liquid crystal material and orthogonal to each other in the in-plane direction And ny, and a retardation film having a relationship of nx = ny <nz between the refractive index nz in the thickness direction, and a carbon number N constituting the polymerizable monomer, The value (N / M) divided by the number M of elements other than carbon and hydrogen constituting the polymerizable monomer (hereinafter sometimes simply referred to as “carbon content ratio”) is 3 or more. Phase difference Irumu have been disclosed. And in patent document 1, it has succeeded in the improvement of the adhesiveness of a phase difference layer and a support body by making it such a structure and improving the adhesiveness of an orientation layer and a support body.

JP 2008-009328 A

The retardation film as described above is usually incorporated in a device such as a liquid crystal display device in which a small amount of moisture adversely affects its performance. Accordingly, if moisture permeates into a layer adjacent to the retardation film or a portion adjacent thereto (hereinafter sometimes referred to as “adjacent layer”), the performance of the device itself is damaged. In addition, as shown in Patent Document 1, the adhesion between the support and the retardation layer is an important issue. However, when the present inventor has studied, the moisture oozing from the retardation film is mainly performed. Although it occurs depending on the support, it has been found that when such a support is selected from a material that hardly causes moisture soaking, the adhesion between the support and the layer adjacent to the support tends to be inferior. Furthermore, in the retardation film described in Patent Document 1, the adhesion between the support and the alignment layer adjacent to the support is improved, but the function as the alignment layer is not sufficient, and the alignment property of the liquid crystal compound is poor. I found out that
The present invention is intended to solve such a problem, and is a retardation film that hardly permeates moisture into adjacent layers or adjacent portions, and has excellent adhesion between a support and a retardation layer. And it aims at providing the phase difference film excellent in the orientation of the liquid crystal compound contained in a phase difference layer.

Under such circumstances, the present inventors have examined, and as a support, the product of moisture permeability and film thickness when the substrate is placed at 40 ° C. and relative humidity 90% for 24 hours is 90 to 6500 g · μm / m ² . A composition comprising a support mainly composed of a polymer and containing a (meth) acrylate monomer, wherein Y (carbon number) / M (carbon atoms and carbon atoms) constituting the (meth) acrylate monomer in the composition Using a (meth) acrylic resin layer obtained by curing a composition having a number of elements other than hydrogen atoms of 1.4 or more and less than 3 as an alignment layer, between the support and the (meth) acrylic resin layer, By providing an intermediate layer including the main component of the support and the main component of the (meth) acrylic resin layer, the above-described problems have been solved. That is, by setting Y (carbon number) / M (number of elements other than carbon atoms and hydrogen atoms) of the (meth) acrylic resin layer which is an adjacent layer to be less than 3, relatively, for example, Patent Document 1 described above. Compared to the above, the ratio of the number of atoms other than carbon atoms and hydrogen atoms is larger. Such a (meth) acrylic resin layer can enhance the orientation of the liquid crystal compound. On the other hand, a support mainly composed of a polymer having a product of moisture permeability and film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and 90% relative humidity for 24 hours is applied to an adjacent layer of water. Is effectively suppressed, but the adhesion to the (meth) acrylic layer tends to be inferior. Therefore, in the present invention, by providing an intermediate layer containing the main component of the support and the main component of the (meth) acrylic resin layer, it succeeded in improving the adhesion between the support and the (meth) acrylic resin layer, The present invention has been completed.
Specifically, the above problem has been solved by the following means <1>, preferably <2> to <18>.

<1> Support, intermediate layer, (meta) mainly composed of a polymer having a product of moisture permeability and film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and 90% relative humidity for 24 hours Having an acrylic resin layer and a retardation layer adjacent to each other in this order;
The (meth) acrylic resin layer is a composition containing a (meth) acrylate monomer, and Y (carbon number) / M (elements other than carbon atoms and hydrogen atoms) constituting the (meth) acrylate monomer in the composition Number) is obtained by curing a composition that is 1.4 or more and less than 3.
The intermediate layer includes the main component of the support and the main component of the (meth) acrylic resin layer,
A retardation film, wherein the retardation layer includes a liquid crystal compound and the alignment state of the liquid crystal compound is fixed.
<2> The retardation film according to <1>, wherein the main component of the support is selected from a cycloolefin polymer, a polystyrene polymer, a polycarbonate polymer, a polyester polymer, and a poly (meth) acrylate polymer.
<3> The retardation film according to <1> or <2>, wherein the main component of the support is a cycloolefin polymer.
<4> The retardation film according to any one of <1> to <3>, wherein Y (carbon number) / M (number of elements other than carbon atoms and hydrogen atoms) is 1.8 or more and less than 2.
<5> The retardation film according to any one of <1> to <4>, wherein the (meth) acrylic resin layer has a hydroxyl group.
<6> The retardation film according to any one of <1> to <5>, wherein the intermediate layer has a thickness of 0.1 to 10 μm.
<7> The retardation film according to any one of <1> to <6>, wherein the support satisfies the following formulas (1) and (2).
Formula (1) 80 <= Re (550) <= 150
Formula (2) 80 ≦ Rth (550) ≦ 150
(In the above formula, Re (550) represents the retardation value in the in-plane direction at a wavelength of 550 nm, and Rth (550) represents the retardation value in the film thickness direction at a wavelength of 550 nm.)
<8> The retardation film according to any one of <1> to <7>, wherein the retardation film satisfies the following formula (3), formula (4), and formula (5).
Formula (3) 80 nm ≦ Re (550) ≦ 150 nm
Formula (4) −100 nm ≦ Rth (550) ≦ 10 nm
Formula (5) 0.05 ≦ | Rth / Re | ≦ 0.5
(In the above formula, Re (550) and Rth (550) represent the retardation value in the in-plane direction and the retardation value in the film thickness direction at a wavelength of 550 nm at 25 ° C. and 60% relative humidity, respectively.)
<9> The retardation film according to any one of <1> to <8>, wherein the retardation layer contains boron.
<10> In the retardation layer, in the thickness direction of the retardation layer, the boron concentration in the region of 1 to 10% from the (meth) acrylic resin layer is 90 to 100 from the (meth) acrylic resin layer. % Retardation film according to any one of <1> to <9>, wherein the retardation film has a concentration higher than the boron concentration in the% region.
<11> The retardation film according to <9> or <10>, wherein the retardation layer comprises a compound having a boronic acid structure and an ethylenically unsaturated double bond.
<12> A method for producing a retardation film having a support, an intermediate layer, a (meth) acrylic resin layer, and a retardation layer in this order adjacent to each other,
On a support composed mainly of a polymer having a moisture permeability and a film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and a relative humidity of 90% for 24 hours, the (meth) acrylic resin layer Y (carbon number) / M (other than carbon atoms and hydrogen atoms) comprising a main component and a solvent having a solubility or swelling ability with respect to the main component of the support and a (meth) acrylate monomer, constituting the (meth) acrylate monomer Applying a composition having an element number) of 1.4 or more and less than 3, and curing the (meth) acrylate monomer;
A method for producing a retardation film, comprising: applying a composition containing a polymerizable liquid crystal compound on the (meth) acrylic resin layer and polymerizing the polymerizable liquid crystal compound.
<13> The method for producing a retardation film according to <12>, wherein the solvent having solubility or swelling ability with respect to the support is selected from at least one of cyclohexanone, methyl isobutyl ketone, toluene, and methylcyclohexane.
<14> Before applying the composition containing the polymerizable liquid crystal compound, the (meth) acrylate monomer is cured such that the degree of cure of the (meth) acrylate monomer is 70% or less, <12> or <12>13> A method for producing a retardation film.
<15> The method for producing a retardation film according to any one of <12> to <14>, comprising a step of stretching the support.
<16> A retardation film produced by the method for producing a retardation film according to any one of <12> to <15>.
<17> A polarizing plate comprising the retardation film of any one of <1> to <11> and <16>.
<18> A liquid crystal display device comprising the retardation film according to any one of <1> to <11> and <16>, or the polarizing plate according to <16>.

  According to the present invention, a retardation film in which moisture hardly oozes into an adjacent layer or the like, has excellent adhesion between a support and a retardation layer, and excellent retardation of a liquid crystal compound contained in the retardation layer. A film can be provided. Furthermore, it has become possible to provide a method for producing such a retardation film and a liquid crystal display device using such a retardation film.

It is a schematic diagram which shows an example of the embodiment of the retardation film of this invention. It is a schematic diagram for demonstrating the measurement of the average content rate of the support body component of an intermediate | middle layer in the retardation film of this invention.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

  In the present specification, “(meth) acrylate” represents acrylate and methacrylate, “(meth) acryl” represents acryl and methacryl, and “(meth) acryloyl” represents acryloyl and methacryloyl.

The retardation film of the present invention is a support mainly composed of a polymer having a product of moisture permeability and film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and 90% relative humidity for 24 hours. A layer, a (meth) acrylic resin layer, and a retardation layer, which are adjacent to each other in this order, and the (meth) acrylic resin layer contains a (meth) acrylate monomer, A composition in which Y (carbon number) / M (number of elements other than carbon atoms and hydrogen atoms) constituting the (meth) acrylate monomer is cured from 1.4 to less than 3, and the intermediate layer is supported. The phase difference layer includes a liquid crystal compound and the alignment state of the liquid crystal compound is fixed, including the main component of the body and the main component of the (meth) acrylic resin layer.
By adopting such a configuration, the retardation film is less likely to soak moisture into the adjacent layer, etc., and has excellent adhesion between the support and the retardation layer, and the orientation of the liquid crystal compound contained in the retardation layer It is possible to provide an excellent retardation film (hereinafter sometimes referred to as “the film of the present invention”).
FIG. 1 schematically shows the layer structure of the retardation film of the present invention. In the retardation film, 1 is a support, 2 is an intermediate layer, and 3 is a (meth) acrylic resin layer. , And 4 represent retardation layers. The support 1 may be a single layer or may be composed of two or more layers. The intermediate layer 2 is provided adjacent to the support 1 and the (meth) acrylic resin layer 3. The (meth) acrylic resin layer may be a single layer or may be composed of two or more layers. When there are two or more (meth) acrylic resin layers, one of them is adjacent to the intermediate layer, and the other layer is adjacent to the retardation film 4. The retardation layer 4 is adjacent to the (meth) acrylic resin layer.
Hereinafter, each member of the retardation film of the present invention will be described in detail.

<Support>
The support used for the retardation film of the present invention is mainly composed of a polymer having a product of moisture permeability and film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and 90% relative humidity for 24 hours. It is a support body. The retardation film is usually incorporated in a device such as a liquid crystal display device in which a small amount of moisture adversely affects performance. Here, when the product of the moisture permeability and the film thickness of the support is increased, moisture starts to penetrate into the adjacent layer and the like, which adversely affects the adjacent layer and the like. That is, even with a support having high moisture permeability, if the film thickness is large, moisture corresponding to the thickness can be secured, so that it is difficult for moisture to soak into the adjacent layers. In addition, if the moisture permeability is low, it is difficult for moisture to soak into the adjacent layers even if the film thickness is somewhat thin. That is, this point is eliminated by setting the product of the moisture permeability and the film thickness of the support within a predetermined range.
Here, the main component means a component having the largest blending amount that constitutes the support, and usually occupies 60% by mass or more of the support, preferably 80% by mass or more of the support. .

<< Physical properties of the support >>
(Moisture permeability and film thickness)
At 40 ° C., 90% relative humidity, the moisture permeability and the thickness of the product when placed for 24 hours, a 90~6500g · μm / m ^2, preferably a 100~6000g · μm / m ^2, 1000 It is more preferable to be ˜6000 g · μm / m ² .
If the product of the moisture permeability and the thickness is less than 90g · μm / m ^2, may adhesion is insufficient, when it exceeds 6000g · μm / m ^2, a long time high temperature and high display panel In the wet durability test, black deposits may be generated on the cell side.

The film thickness of the support of the film of the present invention is preferably 20 to 100 μm, more preferably 20 to 50 μm, still more preferably 20 to 45 μm.
40 ° C. of the film of the present invention, at a relative humidity of 90% is possible in moisture permeability when placed for 24 hours, it is 90~6000g / m ² / 24h is preferred, 1100~6000g / m ² / 24h More preferably, it is 4000-6000 g / m < ² > / 24h.
The moisture permeability of the support can be measured under conditions of 60 ° C. and 95% RH based on JIS Z-0208.
The moisture permeability decreases as the thickness of the support increases as described above, and increases as the thickness decreases. Therefore, for samples having different film thicknesses, it is necessary to convert the reference to 40 μm. The film thickness can be converted according to the following mathematical formula.
Moisture permeability in terms of 40 μm = measured moisture permeability × measured film thickness (μm) / 40 (μm)

(Haze)
The haze of the support used in the present invention is preferably 1.0% or less. More preferably, each is 0.8% or less, and more preferably 0.5% or less. High transparency of the film as the optical film is preferable because the amount of light from the light source can be used without waste.

(Dimension change rate)
The dimensional stability of the support used in the present invention is as follows: dimensional change rate after standing for 24 hours under the conditions of 60 ° C. and 90% RH (high humidity), and 80 ° C. and 5% RH. It is preferable that the dimensional change rate after standing for 24 hours (low temperature) is 0.5% or less.
More preferably, it is 0.3% or less, More preferably, it is 0.15% or less.

(Retardation)
The support preferably satisfies the following formulas (1) and (2). By setting it as such a range, it exists in the tendency which the display performance when incorporating in a liquid crystal display device improves more.
Formula (1) 80 <= Re (550) <= 150
Formula (2) 80 ≦ Rth (550) ≦ 150
Further, it is more preferable to satisfy the following formula (1 ′) and formula (2 ′),
Formula (1 ′) 85 ≦ Re (550) ≦ 145
Formula (2 ′) 50 ≦ Rth (550) ≦ 145
More preferably, the following formula (1 ″) and formula (2 ″) are satisfied,
Formula (1 ″) 90 ≦ Re (550) ≦ 110
Formula (2 ″) 90 ≦ Rth (550) ≦ 110
(In the above formula, Re (550) and Rth (550) represent the retardation value in the in-plane direction and the retardation value in the film thickness direction at a wavelength of 550 nm at 25 ° C. and 60% relative humidity, respectively.)

<< Support material >>
In the support in the present invention, the main component of the support is selected from a cycloolefin polymer, a polystyrene polymer, a polycarbonate polymer, a polyester polymer, and a poly (meth) acrylic acid ester polymer. Preferably there is.
Here, the “main component” means a component having the largest content among the components constituting the support. For example, in the case of a single polymer, it indicates the polymer, and a plurality of polymers. When it consists of, it shows the polymer with the highest mass fraction among the polymers which comprise a support body.
Moreover, in this invention, it is preferable that 95 mass% or more of a support body is a polymer.

  Cycloolefin-based polymers include (1) norbornene-based polymers, (2) monocyclic cycloolefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic hydrocarbon polymers, and There are hydrides of (1) to (4). The cycloolefin polymer preferably used in the present invention is an addition (co) polymer cyclopolyolefin containing at least one repeating unit represented by the following general formula (2) and, if necessary, a general formula (1). It is an addition (co) polymer cyclopolyolefin further comprising at least one repeating unit. A ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (3) can also be suitably used.

In formula, m represents the integer of 0-4. R ^{1 to} R ⁶ are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ^{1 to} X ³ and Y ^{1 to} Y ³ are a hydrogen atom and a hydrocarbon group having 1 to 10 carbon atoms, respectively. , a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms substituted with a halogen _{atom, - (CH 2) n COOR} 11, - (CH 2) n OCOR 12, - (CH 2) n NCO, - (CH 2 _{) n NO 2, - (CH} 2) n CN, - (CH 2) n CONR 13 R 14, - (CH 2) n NR 13 R 14, - (CH 2) n OZ, - (CH 2) n W Or (—CO) ₂ O and (—CO) ₂ NR ¹⁵ composed of X ¹ and Y ^1, X ² and Y ^2, or X ³ and Y ³ . R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are each a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _3-p (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom, —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), n is 0 to 10 Indicates an integer.

By introducing a polarizable large functional group in a substituent ^{X 1 ~X 3, Y 1 ~Y} 3, by increasing the thickness-direction retardation of the optical film (Rth), in-plane retardation (Re) The expression can be increased. A film having a high Re developability can increase the Re value by stretching in the film forming process.

  As the cycloolefin-based polymer, those disclosed in JP-A No. 10-7732, JP 2002-504184 A, US200029157A1 or International Publication No. 2004 / 070463A1 can be used. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and conjugated dienes such as ethylene, propylene, butene, butadiene and isoprene; non-conjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. As this norbornene type addition (co) polymer, a commercial item can also be used. Specifically, grades such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C), or APL6015T (Tg145 ° C), which are sold under the trade name of Apel from Mitsui Chemicals, Inc. and have different glass transition temperatures (Tg), are used. There is. Pellets such as TOPAS 8007, 6013, and 6015 are sold by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

Norbornene-based polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-1159767, or As disclosed in Japanese Patent Application Laid-Open No. 2004-309979 and the like, it is possible to use those produced by hydrogenation after addition polymerization or metathesis ring-opening polymerization of a polycyclic unsaturated compound. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. The As this norbornene resin, commercially available products can be used. Specifically, JSR Co., Ltd. is marketed under the trade name Arton G or Arton F, and ZEONOR from Nippon Zeon Co., Ltd. ) ZF14, ZF16, Zeonex 250 or ZEONEX 280 are commercially available and can be used.

  The cycloolefin polymer used in the present invention preferably has a mass average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 5,000 to 1,000,000 in terms of polystyrene molecular weight. More preferably, it is 50,000-500,000, and it is further more preferable that it is 50,000-300,000. Moreover, it is preferable that molecular weight distribution (Mw / Mn; Mn is the number average molecular weight measured by GPC) is 10 or less, More preferably, it is 5.0 or less, More preferably, it is 3.0 or less. The glass transition temperature (Tg; measured by DSC) is preferably 50 to 350 ° C, more preferably 80 to 330 ° C, and still more preferably 100 to 300 ° C.

  The cycloolefin-based polymer of the present invention may contain an additive within a range not departing from the gist of the present invention, and the description of paragraph numbers 0025 to 0074 and 0086 to 0091 of JP-A-2009-114303 can be referred to. The contents of which are incorporated herein by reference.

As the polystyrene-based polymer used as the support, the polystyrene-based polymers described in paragraph numbers 0016 to 0019 of JP2012-208261A can be used, and as the polycarbonate-based polymer, JP2012-166503A is disclosed. Can be used. Polyester polymers described in paragraphs 0011 to 0017 of JP-A No. 11-256115 can be used as polyester polymers. As the poly (meth) acrylate polymer, the poly (meth) acrylate polymer described in paragraph No. 0091 of JP2012-166503A can be used, and these are incorporated in the present specification. It is.
As these, commercially available products can be used. As a commercially available product of polystyrene polymer, styrene-maleic anhydride copolymer D332 (manufactured by NOVA Chemicals), and as a commercially available product of polycarbonate polymer, Panlite L1225 (Teijin) ), As the polyester polymer, Tetron K (polyethylene terephthalate resin, manufactured by Teijin DuPont), and as the poly (meth) acrylic acid ester polymer, the dialal BR88 (acrylic resin, manufactured by Mitsubishi Rayon Co., Ltd.) These can be used.

<< Method for Manufacturing Support >>
A well-known method can be employ | adopted for the manufacturing method of the support body in this invention. For example, the dope was cast on a casting support such as a metal support, and the film was formed by evaporating the solvent to form a support film, and then the stretching process of stretching the film, and then obtained. It is preferable to have a drying step for drying the film, and further a heat treatment step after the completion of the drying step. Hereinafter, the manufacturing method of a cycloolefin film is demonstrated as an example.

Although the manufacturing method of a cycloolefin film is not specifically limited, There are a melt film forming method and a solution film forming method, and among these, the solution film forming method is particularly preferable. A cyclopolyolefin film is produced by one of two production methods among the solution casting methods.
1. A process for producing a cyclopolyolefin film, which comprises a step of dissolving or dispersing at least one compound in a solvent, a step of casting, a step of drying, and a step of winding.
2. A method for producing a cyclopolyolefin film comprising a step of dissolving a cyclopolyolefin-based resin in a solvent, a step of casting, a step of drying, and a step of winding, wherein at least one of the films after casting A method for producing a cyclopolyolefin film, comprising a step of applying a coating solution containing at least one compound on a surface.
Moreover, it is preferable to extend | stretch after the said casting process.

  The two production methods 1 and 2 are different in the way of incorporating the compound into the cyclopolyolefin film. In the method 1, the compound is dissolved or dispersed in the same layer with respect to the layer containing the cyclopolyolefin resin as a main component, whereas in the method 2, the compound is dissolved in a layer containing the cyclopolyolefin resin as a main component. It differs in the point which coats the coating liquid containing a compound. Hereinafter, although it explains in full detail for each process from (the process to melt | dissolve, dope preparation)-(the process to wind up after drying), said 1 manufacturing method is melt | dissolved or disperse | distributed in (the process to melt | dissolve, dope preparation). , Except for the addition, is the same as the production method of 2 above.

  Regarding the dissolving step, dope preparation, casting, multi-layer casting, subsequent casting, drying, and peeling step, the description in paragraphs 0094 to 0109 of JP-A-2009-114303 can be referred to, and the contents thereof are described in the present specification. Embedded in the book.

(Extension process)
When the cyclopolyolefin film is stretched, it is preferably carried out in a state where the solvent remains sufficiently in the film immediately after peeling.
The draw ratio is preferably 20 to 100%, more preferably 40 to 90%, and still more preferably 50 to 80%.
As extending | stretching temperature, it is preferable that it is 100-200 degreeC, It is more preferable that it is 115-185 degreeC, It is further more preferable that it is 130-170 degreeC.

  The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. The birefringence of the optical compensation film for a VA liquid crystal cell or OCB liquid crystal cell is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction.

  Regarding the post-drying and winding processes, the description of paragraph number 0112 of JP-A-2009-114303 can be referred to, and the contents thereof are incorporated in the present specification.

<(Meth) acrylic resin layer>
The film of the present invention has a (meth) acrylic resin layer. The (meth) acrylic resin layer functions as an alignment layer and appropriately aligns the liquid crystal compound contained in the retardation layer.

The (meth) acrylic resin layer is a composition containing a (meth) acrylate monomer, and Y (carbon number) / M (elements other than carbon atoms and hydrogen atoms) constituting the (meth) acrylate monomer in the composition Number) is obtained by curing a composition having a number of 1.4 or more and less than 3, and relatively, for example, the ratio of the number of atoms other than carbon atoms and hydrogen atoms is larger than that of Patent Document 1 above. Become.
Y / M is 1.4 or more and less than 3, preferably 1.8 or more and less than 2, and more preferably 1.9 or more and less than 2. By setting it as such a range, the effect of this invention is exhibited more effectively.
In particular, in the present invention, it is preferable that 95% or more of the atoms constituting the (meth) acrylate monomer is any one of a carbon atom, an oxygen atom and a hydrogen atom, and 100% is any one of a carbon atom, an oxygen atom and a hydrogen atom. More preferably.

  The (meth) acrylic resin layer in the present invention preferably has a polar group, and the polar group is preferably a hydroxyl group. By having a hydroxyl group, the adhesion to the support is improved.

As a (meth) acrylate monomer that forms a (meth) acrylic resin layer, a compound containing one (meth) acryloyl group in one molecule and a compound containing two or more (meth) acryloyl groups are used in combination. Preferably, a compound containing one (meth) acryloyl group in one molecule and a compound containing two to four (meth) acryloyl groups are more preferably used in combination.
The (meth) acrylate monomer in the present invention preferably has a molecular weight of 100 to 800, more preferably 150 to 500.

  Specific examples of (meth) acrylate monomers include (meth) acrylic acid diesters of alkylene glycol, (meth) acrylic acid diesters of polyoxyalkylene glycol, (meth) acrylic acid diesters of polyhydric alcohols, ethylene oxide or propylene. (Meth) acrylic acid diesters of oxide adducts, epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, and the like.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. For example, glycerin monomethacrylate, 1,6-hexanediol acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO-modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipenta Erythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, , 2,3-cyclohexane tetramethacrylate, urethane acrylate, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  A commercially available (meth) acrylate monomer can also be used. For example, examples of the polyfunctional acrylate compounds having a (meth) acryloyl group include KAYARAD PET30, KAYARAD DPHA, DPCA-30, and DPCA-120 manufactured by Nippon Kayaku Co., Ltd. Examples of the urethane acrylate include U15HA manufactured by Shin-Nakamura Chemical Co., Ltd., U4HA, A-9300, and EB5129 manufactured by Daicel UCB.

  The acrylic resin is a layer obtained by crosslinking an acrylic monomer with light or heat, and the polar group is particularly preferably a hydroxyl group. Thereby, the rod-like liquid crystal compound can be effectively homeotropically aligned in a retardation layer (retardation layer) in which the alignment state of the liquid crystal compound described later is fixed.

  As a film thickness of a (meth) acrylic resin layer, 0.1-10 micrometers is preferable, 0.4-3.0 micrometers is more preferable, 1.0-2.0 micrometers is further more preferable.

  The water droplet contact angle of the (meth) acrylic resin layer was determined by adjusting the film for 2 hours or more at 25 ° C. and a relative humidity of 60%, dropping a 3 mm diameter pure water droplet on the surface, Calculate from the angle formed by the water droplets. The water droplet contact angle of the acrylic resin layer is preferably 25 ° to 60 °, more preferably 35 ° to 57 °, and still more preferably 40 ° to 54 °.

  A method for forming the (meth) acrylic resin layer will be described later.

<Intermediate layer>
The film of the present invention has an intermediate layer adjacent to these layers between the support and the (meth) acrylic layer. The intermediate layer in the present invention includes the main component of the support and the main component of the (meth) acrylic resin layer. Here, the main component means a component having the highest content among the components contained in each layer. For example, the main component of the support is usually a polymer. When the support contains two or more types of polymers, the intermediate layer needs to contain a component having the highest content among the two or more types of polymers contained in the support. Of the polymers of more than one type, it is preferable to include both a component having a high content first and a component having a high content second. The main component of the (meth) acrylic resin layer is a (meth) acrylic resin. When the (meth) acrylic resin layer contains two or more types of (meth) acrylic resins, the intermediate layer has the highest content among the two or more types of (meth) acrylic resins contained in the (meth) acrylic resin layer. Of the two or more types of (meth) acrylic resins contained in the (meth) acrylic resin layer, first, both the component with the high content and the second component with the high content It is preferable that it contains.
In the film of this invention, the adhesiveness of a support body and a (meth) acryl layer can be improved by having the intermediate | middle layer containing the main component of a support body, and the main component of a (meth) acrylic resin layer.

The average content of the main component of the support contained in the intermediate layer is preferably 1 to 50% by mass, and more preferably 1 to 25% by mass.
The average content of the main components of the (meth) acrylic resin layer contained in the intermediate layer is preferably 50 to 99% by mass, and more preferably 75 to 99% by mass.
The ratio (mass ratio) of the main component of the support and the main component of the (meth) acrylic resin layer in the intermediate layer is 0.01 <main component of the support / main component of the (meth) acrylic resin layer <0.5. Is preferred.
By making it become such a ratio, it exists in the tendency which is more excellent in adhesiveness.

The average content (% by mass) of the support component in the intermediate layer can be determined as follows. As shown in FIG. 2, the surface secondary ion intensity I1 is measured using TOF-SIMS (Time of Flight-Secondary Ion Mass Spectrometry) with respect to the support film surface.
Next, when the cross section of the film was cut with a microtome, a slice was cut out at an inclination angle of 87 ° when the film thickness direction was 0 ° and the in-plane direction was 90 °.
The secondary ion intensity I2 at the intermediate layer 2 portion is measured with respect to the cutting surface cut out by the above method.

  Next, the average content of the support component can be determined by calculating the average content (% by mass) of the support component from the average content = I2 / I1 × 100.

  The measurement of TOF-SIMS can be observed, for example, by detecting fragments of components present on the film surface using TRIFT II type TOF-SIMS (trade name) manufactured by Phi Evans. The TOF-SIMS method is specifically described in “Surface Analysis Technology Selection Secondary Ion Mass Spectrometry” Maruzen Co., Ltd. (1999), edited by the Surface Science Society of Japan.

The film thickness of the intermediate layer in the present invention is not particularly defined, but can be, for example, 0.01 to 20 μm, preferably 0.1 to 10 μm, and preferably 0.2 to 9 μm. More preferably, 0.5-2 micrometers is further more preferable.
The film thickness of the intermediate layer in the present invention refers to a method measured according to Examples described later.

<< (Method for forming (meth) acrylic resin layer and intermediate layer >>
As the method for forming the intermediate layer in the present invention, a known method can be adopted, but it is preferably formed in the process of forming the (meth) acrylic resin layer on the surface of the support. That is, on the support, the main component of the (meth) acrylic resin layer and a solvent having a solubility or swelling ability with respect to the main component of the support and a (meth) acrylate monomer, and constituting the (meth) acrylate monomer A composition in which (carbon number) / M (number of elements other than carbon atoms and hydrogen atoms) is 1.4 or more and less than 3 is applied on a support and formed by curing a (meth) acrylate monomer. Can do. The solvent dissolves or swells the support and the (meth) acrylic resin layer in the forming process by using a solvent having a solubility or swelling ability with respect to the main component of the (meth) acrylic resin layer and the main component of the support. Thereafter, the solvent is volatilized to form an intermediate layer in which the main component of the support and the main component of the (meth) acrylic resin layer are mixed. Volatilization of the solvent having solubility or swelling ability may be performed by means such as drying, or may be performed by heating in the subsequent formation process of the retardation layer or the like. Moreover, natural drying may be sufficient. The solvent having the solubility or swelling ability of the main component of the (meth) acrylic resin layer and the main component of the support used in the present invention is the solubility and swelling of the main component of the (meth) acrylic resin layer and the major component of the support. It is preferable that the solvent has a function.

The solvent having the ability to dissolve or swell the main component of the (meth) acrylic resin layer and the main component of the support means a solvent highly compatible with the main component of the (meth) acrylic resin layer and the main component of the support. Depending on the solubility and swelling ability with respect to the resin used for the support, it can be used properly.
The solvent having solubility or swelling ability with respect to the main component of the (meth) acrylic resin layer and the main component of the support used in the present invention is preferably selected from at least one of cyclohexanone, methyl isobutyl ketone, toluene and methylcyclohexane. Cyclohexanone is more preferable.
These can be used alone or in combination of two or more.

  From the viewpoint of swelling the support and the (meth) acrylic resin layer and improving adhesion, the solvent preferably contains at least one of methyl acetate and cyclohexanone, and is a mixed solvent containing methyl acetate and cyclohexanone. More preferably.

The solvent having the ability to dissolve the main component of the (meth) acrylic resin layer and the main component of the support is a 15 cm ³ bottle containing a support film having a size of 24 mm × 36 mm (thickness 80 μm). When the soaked solution was analyzed by gel permeation chromatography (GPC) after being immersed for 60 seconds at room temperature (25 ° C.), the peak area of the main component of the support was 400 mV / sec or more. It means a solvent. Alternatively, a support film having a size of 24 mm × 36 mm (thickness: 80 μm) is aged in a 15 cm ³ bottle containing the solvent at room temperature (25 ° C.) for 24 hours, and the bottle is shaken as appropriate. What dissolves and loses its shape also means a solvent capable of dissolving the main component of the support.
The solvent having swelling ability with respect to the main component of the support means that a support film having a size of 24 mm × 36 mm (thickness 80 μm) is vertically placed in a 15 cm ³ bottle containing the solvent and immersed at 25 ° C. for 60 seconds. It means a solvent that can be bent and deformed when observed while shaking the bottle as appropriate (the film is observed as bent or deformed due to the change in the size of the swollen portion. No change).

In addition, in order to control the effect of the solvent, a solvent having neither solubility nor swelling ability with respect to the main component of the (meth) acrylic resin layer and the main component of the support can be used in combination.
Examples of the solvent having neither dissolving ability nor swelling ability include methanol and ethanol.
The addition amount of the solvent having neither dissolving ability nor swelling ability is preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 1% by mass or less with respect to the total solvent used.

<Phase difference layer>
The retardation layer in the present invention is a layer containing a liquid crystal compound and fixing the alignment state of the liquid crystal compound, and the (meth) acrylic layer and the retardation layer are adjacent to each other.
The retardation layer is preferably a layer in which the liquid crystal compound is fixed in a homeotropic alignment state.
Homeotropic alignment is an alignment state in which liquid crystal molecules are aligned in the normal direction of the layer and the slow axis is parallel to the normal direction of the layer. Note that the slow axis of the retardation layer is particularly preferably parallel to the normal direction of the layer, but may have an inclination depending on the alignment state of the liquid crystal molecules. If this inclination is within 3.5 °, the in-plane retardation can be made 10 nm or less, which is preferable.

<< Liquid Crystal Compound >>
The liquid crystal compound is preferably a layer formed by fixing the homeotropic alignment of a composition containing a rod-like liquid crystal compound or a discotic liquid crystal compound as a main component from the viewpoint of the optical properties of the retardation film.
The layer in which the homeotropic alignment of the rod-like liquid crystal compound is fixed can function as a positive C-plate. Further, the layer in which the homeotropic alignment of the discotic liquid crystal compound is fixed can function as a positive or negative C-plate.

  Usable rod-like liquid crystal compounds are described in, for example, [0045] to [0066] of JP-A-2009-217256, and the contents thereof are incorporated herein.

  Examples of the discotic liquid crystal compound include [0025] to [0153] in JP-A-2006-301614, [0020] to [0122] in JP-A-2007-108732, and [ [0012] to [0108], the contents of which are incorporated herein.

  The additive that can be used in the retardation layer in the present invention and the method for forming the homeotropic liquid crystal layer are described in, for example, JP-A-2009-237421, [0076] to [0079]. Is incorporated herein.

<< Compound containing boron >>
The retardation layer in the present invention preferably contains boron, and more preferably, boron is unevenly distributed on the side closer to the (meth) acrylic resin layer. By setting it as such a structure, the adhesiveness of a (meth) acrylic resin layer and a phase difference layer can be improved more.
In the present invention, the compound containing boron contained in the retardation layer preferably contains a compound having a boronic acid structure and an ethylenically unsaturated double bond.
In the present invention, boron (usually a compound containing boron) is unevenly distributed on the side close to the (meth) acrylic resin layer, and in the film thickness direction of the retardation layer, the (meth) acrylic resin layer It is preferable that the boron concentration in the region of 1 to 10% is higher than the boron concentration in the region of 90 to 100% from the (meth) acrylic resin layer. By unevenly distributing in this way, the adhesion between the (meth) acrylic resin layer and the retardation layer can be further improved. Usually, when a compound containing boron is blended in the retardation layer, the compound containing boron is naturally unevenly distributed closer to the (meth) acrylic resin layer.

Examples of the compound containing boron include boron fluoride and boronic acid, and the boronic acid is preferably represented by the following general formula (I).
Formula (I)
(Z) _n -L ^100- (Q) _m
(In the formula, Z represents a substituent having a polymerizable group, n represents an integer of 0 to 4, and when n is 2 or more, two or more Zs may be the same or different, and Q is at least one. Represents a substituent containing a boron atom, m represents 1 or 2, and when m is 2, two Qs may be the same or different, L ¹⁰⁰ represents an n + m-valent linking group, and n is 0 And when m is 1, L ¹⁰⁰ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted group Represents a heteroaryl group.)

  In the general formula (I), examples of the substituent having a polymerizable group represented by Z include an acrylate group, a methacrylate group, a styryl group, a vinyl ketone group, a butadiene group, a vinyl ether group, an oxiranyl group, an aziridinyl group, and an oxetane group. The substituent to include is mentioned. Among these, a substituent containing a (meth) acrylate group, a styryl group, an oxiranyl group or an oxetane group is preferable, and a substituent containing a (meth) acrylate group or a styryl group is more preferable.

  In particular, the substituent containing a (meth) acrylate group is preferably a group having an ethylenically unsaturated double bond represented by the following general formula (III).

In general formula (III), R < ³ > is a hydrogen atom or a methyl group, and a hydrogen atom is preferable. L ¹ is a single bond or —O—, —CO—, —NH—, —CO—NH—, —COO—, —O—COO—, an alkylene group, an arylene group, a heterocyclic group, and combinations thereof. A divalent linking group selected from the group consisting of a single bond, —CO—NH—, or —COO—, and a single bond or —CO—NH— is particularly preferred.

In general formula (I), L ¹⁰⁰ represents an n + m-valent linking group. When n is 0 and m is 1, L ¹⁰⁰ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted group. An alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group is represented.
n represents an integer of 0 to 4, more preferably represents 0 or 1, and more preferably represents 1. m represents 1 or 2, and more preferably represents 1.
As L ¹⁰⁰ , for example, as a divalent linking group, a single bond, —O—, —CO—, —NH—, —CO—NH—, —COO—, —O—COO—, an alkylene group, arylene And a divalent linking group selected from a group, a heteroaryl group, and a combination thereof. Of these, a substituted or unsubstituted arylene group is more preferable. Further, the alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group represented by L ¹⁰⁰ have the same meanings as those represented by R ¹ and R ² in the following general formula (II), and the preferred ranges are also the same. is there. Moreover, the example of the substituent which these groups have is at least 1 sort (s) chosen from the following substituent group Y.

  In general formula (I), Q is a substituent containing at least one boron atom, and is preferably a group that can be adsorbed and bonded to the alignment film. For example, when the alignment film has a hydroxyl group such as polyvinyl alcohol, a group capable of binding to the hydroxyl group of the alignment film is preferable. The “group that can be adsorbed and bonded to the alignment film” means a group that can be chemically adsorbed to the alignment film by interacting with a group of the material (mainly polymer) constituting the alignment film. Means. When the compound represented by the general formula (A) is contained in the alignment film, whether or not it is a group that can be adsorbed to the alignment film depends on the material (mainly a polymer) constituting the alignment film. It is judged by whether or not it is possible to interact with the group possessed by.

  Examples of the substituent containing at least one boron atom include a substituent represented by the following general formula (II).

In general formula (II), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. Alternatively, R ¹ and R ² may be linked to form a linking group consisting of an alkylene group, an aryl group, or a combination thereof.

In general formula (II), the substituted or unsubstituted aliphatic hydrocarbon group represented by R ¹ and R ² includes a substituted or unsubstituted alkyl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group. , Octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1 Examples thereof include linear, branched or cyclic alkyl groups such as -adamantyl group and 2-norbornyl group. Specific examples of the alkenyl group include linear, branched, such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, and 1-cyclohexenyl group. And cyclic or alkenyl groups.
Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group. Specific examples of the aryl group include those in which 1 to 4 benzene rings form a condensed ring, and those in which a benzene ring and an unsaturated five-membered ring form a condensed ring. Specific examples include Examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, a fluorenyl group, and a pyrenyl group.

Specific examples of the substituted or unsubstituted aryl group represented by R ¹ and R ² include a phenyl group and a naphthyl group. Examples of the substituted or unsubstituted heteroaryl group represented by each of R ¹ and R ² include hydrogen on a heteroaromatic ring containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. Including those in which one atom is removed to form a heteroaryl group. Specific examples of the heteroaromatic ring containing one or more heteroatoms selected from the group consisting of nitrogen atom, oxygen atom and sulfur atom include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole and oxadiazole. , Thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazolebenzimidazole, anthranyl, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, acridine, Examples thereof include isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, and pteridine.

R ¹ , R ² and L ¹⁰⁰ may be further substituted with one or more substituents when possible. One or more of these hydrocarbon groups may be substituted with an arbitrary substituent. Examples of the substituent include monovalent nonmetallic atomic groups excluding hydrogen.

R ¹ and R ² in the general formula (II) are preferably hydrogen atoms.

  Specific examples of the compound represented by the general formula (1) include the following compounds in addition to the compounds exemplified in paragraphs 0035 to 0040 of JP-A-2007-219193. Is incorporated herein by reference. Of course, the present invention is not limited to these specific examples.

<< Other additives >>
In the retardation layer in the present invention, other additives may be blended without departing from the spirit of the present invention.
In the present invention, for example, a vertical alignment agent can be blended. As the vertical alignment agent, it is preferable to use a pyridinium compound or an onium compound. By containing these compounds, the vertical alignment agent acts as a vertical alignment agent that promotes homeotropic alignment at the alignment film interface of the liquid crystal compound. This also contributes to improving the adhesion at the interface between the retardation layer (retardation layer) and the acrylic resin layer in which the alignment state is fixed. The retardation layer (retardation layer) in which the alignment state of the liquid crystal compound is fixed includes an air interface side alignment control agent (for example, a repeating unit having a fluoroaliphatic group) that controls the alignment on the air interface side as necessary. A copolymer). The pyridinium compound is described in, for example, [0030] to [0052] of JP-A-2007-093864, and the onium compound is described in, for example, [0027] to [0058] of JP-A-2012-208397, These contents are incorporated herein.
Moreover, in this invention, a polymerization initiator can be mix | blended, for example. As the polymerization initiator, the description of paragraphs 0099 to 0100 of JP 2010-84032 A and paragraphs 0065 to 0067 of JP 2007-219193 A can be referred to, and the contents thereof are incorporated in the present specification.

Re (550) when the retardation layer is placed at 25 ° C. and 60% relative humidity for 24 hours is preferably 0 to 10 nm, more preferably 0 to 3 nm, and still more preferably 0 to 1 nm.
The Rth (550) when the retardation layer is placed at 25 ° C. and 60% relative humidity for 24 hours is preferably −100 to −250 nm, more preferably −120 to −230 nm, and further preferably −140 to −210 nm.
The thickness of the retardation layer is preferably 0.5 to 2.0 μm, and more preferably 1.0 to 2.0 μm.

The retardation layer is prepared by preparing a composition, coating the retardation layer coating solution on the (meth) acrylic resin layer, and reacting and curing the polymerizable group in the liquid crystal compound to form the retardation layer. .
In the formation of the (meth) acrylic resin layer and the retardation layer, the polymerization of the (meth) acrylic resin layer is not completed, leaving an unreacted polymerizable group in the acrylic resin layer, and the polymerization of the retardation layer. A technique for improving the adhesion of the interface by causing a polymerization reaction at the interface between the (meth) acrylic resin layer and the retardation layer by combining and reacting the unreacted polymerizable groups of the (meth) acrylic resin layer during curing. Can also be used.

  Specifically, before applying the composition containing the polymerizable liquid crystal compound, it is preferable to cure the (meth) acrylate monomer so that the degree of cure of the (meth) acrylate monomer is 70% or less.

<Retardation of retardation film>
The film of the present invention satisfies the following formulas (3) and (4). By setting it as such a range, it exists in the tendency which the display performance when incorporating in a liquid crystal display device improves more.
Formula (3) 80 nm ≦ Re (550) ≦ 150 nm
Formula (4) −100 nm ≦ Rth (550) ≦ 10 nm
Further, it is more preferable to satisfy the following formula (3 ′) and formula (42 ′),
Formula (3 ′) 85 ≦ Re (550) ≦ 145
Formula (4 ′) − 100 ≦ Rth (550) ≦ 50
More preferably, the following formula (3 ″) and formula (4 ″) are satisfied,
Formula (3 ″) 90 ≦ Re (550) ≦ 110
Formula (4 ″) −50 ≦ Rth (550) ≦ −20
(In the above formula, Re (550) represents the retardation value in the in-plane direction at a wavelength of 550 nm, and Rth (550) represents the retardation value in the film thickness direction at a wavelength of 550 nm.)

<Haze of retardation film>
The haze of the retardation film of the present invention is preferably 1.0% or less. More preferably, it is 0.8% or less, and further preferably 0.5% or less.

<Polarizing plate>
The polarizing plate of the present invention is a polarizing plate having a polarizing film and two protective films protecting both surfaces of the polarizing film, and at least one of the protective films is the retardation film of the present invention.
Of the two protective films, one is the retardation film of the present invention, and the other is preferably a film made of an acrylic resin from the viewpoint of curling of the polarizing plate after polarizing plate processing. Examples of the film made of acrylic resin include acrylene (manufactured by Mitsubishi Rayon Co., Ltd.), technoloy (manufactured by Sumitomo Chemical Co., Ltd.), and kenduren (manufactured by Kaneka Corporation).
Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine-based polarizing film and the dye-based polarizing film can be generally produced using a polyvinyl alcohol film.

  The total film thickness of the polarizing plate (total film thickness of retardation film, polarizing film and protective film) is preferably 80 to 120 μm.

  When the retardation film of the present invention is used as a surface protective film (polarizing plate protective film) for a polarizing film (polarizer), the surface of the support, that is, the surface to be bonded to the polarizing film is hydrophilized. By performing this, it is possible to improve the adhesiveness with a polarizing film containing polyvinyl alcohol as a main component.

<Liquid crystal display device>
The liquid crystal display device of the present invention has the retardation film or polarizing plate of the present invention.
The retardation film of the present invention can be advantageously used in a transverse electric field mode liquid crystal display device.

A liquid crystal cell having two cell substrates and a liquid crystal layer sandwiched between them and aligned in parallel with the substrate in the vicinity of the cell substrate when no voltage is applied; A pair of disposed polarizing plates, a first retardation film disposed between one polarizing plate and the cell substrate, and a second retardation film disposed between the other polarizing plate and the cell substrate The slow retardation axis of the first retardation film is arranged so as to be orthogonal to the major axis of the liquid crystal molecules in the vicinity of the inner side of the cell substrate adjacent to the first retardation film when no voltage is applied. In the liquid crystal display device operating in the transverse electric field mode, it is preferable that either the first retardation film or the second retardation film is the retardation film of the present invention.
Further, another preferred embodiment of the liquid crystal display device of the present invention is as follows:
A first substrate on which unit pixels are arranged; a second substrate facing the first substrate; a liquid crystal layer formed between the first substrate and the second substrate and arranged in a first direction; A first polarizing plate formed outside the first substrate and having a polarization transmission axis parallel to the first direction, and a first polarizing plate formed outside the second substrate and having a polarization transmission axis perpendicular to the first direction. The first polarizing plate includes a polyvinyl alcohol film having a polarizing function, and a triacetyl cellulose film or an acrylic film on the inner and outer surfaces of the polyvinyl alcohol film, and the second polarizing plate. The polarizing plate is a polyvinyl alcohol film having a polarizing function, and a triacetyl cellulose film or an acrylic film on one surface of the polyvinyl alcohol film. , A phase difference film which is formed on the other surface of the polyvinyl alcohol film, the retardation film is a liquid crystal display device is a retardation film of the present invention.

In the present specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Re is measured by making light with a wavelength of λ nm incident in the normal direction of the film in KOBRA21ADH (manufactured by Oji Scientific Instruments). Rth was measured by making light having a wavelength λ nm incident from a direction inclined + 40 ° with respect to the normal direction of the film with the slow axis in the plane (determined by KOBRA 21ADH) as the tilt axis (rotation axis). A retardation value and a retardation value measured by making light of wavelength λ nm incident from a direction inclined by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). KOBRA 21ADH is calculated based on the retardation value measured in the direction. Here, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting the assumed value of the average refractive index and the film thickness, KOBRA 21ADH calculates nx, ny, and nz. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.
Note that Re = (nx−ny) × d and Rth = {(nx + ny) / 2−nz} × d. nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the fast axis direction in the film plane, nz is the refractive index in the thickness direction of the film, and d is the thickness of the film. (Nm).
The measurement wavelength of the refractive index is a value at λ = 550 nm in the visible light region unless otherwise specified, and the measurement wavelength of Re and Rth is 550 nm unless otherwise specified.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Example 1]
<Production of retardation film>
<< Support >>
A cycloolefin polymer film (Zeonor, ZF14 manufactured by Nippon Zeon Co., Ltd.) was used as the support.

<< Formation of intermediate layer and (meth) acrylic layer >>
A (meth) acrylic resin layer forming composition was prepared by mixing the (meth) acrylate monomer described below and a solvent. More specifically, a (meth) acrylic resin layer forming composition was prepared as follows.
100 parts by weight of (meth) acrylic compound (a total of two when two kinds are used), 4 parts by weight of a photopolymerization initiator (Irgacure 127, manufactured by Ciba Specialty Chemicals), and a solvent are mixed, A (meth) acrylic resin layer forming composition was prepared.
In addition, the composition ratio of the (meth) acrylate compound and the solvent is described in the table as a mass ratio. Moreover, the solid content concentration (unit mass%) of the composition for forming an acrylic resin layer is described in the column of “Concentration” in the table.
The composition for forming a (meth) acrylic resin layer thus prepared was applied onto the above support with a composition for forming a (meth) acrylic resin layer using a wire bar coater # 1.6, and the composition was applied at 60 ° C., 0.5 After partial drying, the acrylic resin layer was crosslinked by irradiating with ultraviolet rays at 30 ° C. for 30 seconds using a 120 W / cm high-pressure mercury lamp. The film thickness of the obtained acrylic resin layer was described in the table.
Moreover, the solvent contained in the composition for forming a (meth) acrylic resin layer dissolves the support, whereby the main component of the support and the (meth) acrylic resin layer are interposed between the support and the (meth) acrylic resin layer. An intermediate layer containing the main component of was formed. The thickness of the intermediate layer was obtained by cutting a cross section of the film with a microtome to prepare a sample, dyed with osmic acid vapor for one day, and then observing the film thickness profile of the cured layer with a scanning electron microscope.

The average content (% by mass) of the support component in the intermediate layer was determined as follows.
(Quantification of support components)
As shown in FIG. 2, the secondary ionic strength I1 of the surface was measured on the film surface using TOF-SIMS (Time of Flight—Secondary Ion Mass Spectrometry).
Next, when the cross section of the film was cut with a microtome, a slice was cut out at an inclination angle of 87 ° when the film thickness direction was 0 ° and the in-plane direction was 90 °.
The secondary ion intensity I2 at the intermediate layer portion was measured with respect to the cut surface cut out by the above method.
Next, the average content (mass%) of the support component was determined from the average content = I2 / I1 × 100.

The measurement of TOF-SIMS was observed by detecting fragments of components present on the film surface using TRIFT II type TOF-SIMS (trade name) manufactured by Phi Evans. Specifically, it detected from the intensity | strength of the following secondary ions.
Cycloolefin polymer: C ₅ H ₇ ⁺
(Meth) acrylic resin layer: C ₅ H ₉ ⁺

ブレンマーＧＬＭ：日油（株）製、下記構造の化合物。

アリルα−Ｄ−ガラクトピラノシド：アルドリッチ社製、下記構造の化合物。

The compounds used are shown below.
KAYARAD PET30: Nippon Kayaku Co., Ltd., a mixture of compounds having the following structure. The weight average molecular weight is 298, and the number of functional groups in one molecule is 3.4 (average).

BLEMMER GLM: NOF Corporation, a compound having the following structure.

Allyl α-D-galactopyranoside: a compound having the following structure, manufactured by Aldrich.

<< Formation of retardation layer >>
On the acrylic resin layer, 1.44 g of liquid crystal compound 1 described in the following table, 0.36 g of liquid crystal compound 2, 0.06 g of photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy), sensitizer (Kayacure DETX) , Manufactured by Nippon Kayaku Co., Ltd.) 0.02 g, vertical alignment agent 0.0012 g, boron compound 0.0006 g in the table mixed in a ratio of MEK / cyclohexanone = 86/14, solid content concentration 33% The solution so dissolved was applied with a wire bar # 3.2. This was affixed to a metal frame and heated in a constant temperature bath at 100 ° C. for 2 minutes to align the rod-like liquid crystal compound. Next, after cooling to 50 ° C., using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an oxygen concentration of about 0.1% under a nitrogen purge, an illuminance of 190 mW / cm 2 and an irradiation amount of 300 mJ / The coating layer was cured by irradiating with cm ² ultraviolet rays. Then, it stood to cool to room temperature.
In this manner, laminated retardation films each having a retardation layer composed of a homeotropic liquid crystal layer on an acrylic resin layer were produced.

液晶化合物２

垂直配向剤

The compounds used are shown below.
Liquid crystal compound 1

Liquid crystal compound 2

Vertical alignment agent

[Examples 2 to 41, Comparative Examples 1 to 7]
In Example 1, a retardation film was produced in the same manner as in Example 1 except that the materials for the support, the (meth) acrylic resin layer, and the retardation layer were changed as shown in the following table.

ホウ素化合物２ Ｐｈｅｎｙｌｂｏｒｏｎｉｃ ａｃｉｄ アルドリッチ社

ホウ素化合物３Ｐｏｔａｓｓｉｕｍ （４−ｖｉｎｙｌｐｈｅｎｙｌ）ｔｒｉｆｌｕｏｒｏｂｏｒａｔｅ アルドリッチ社

また、中間層の測定にあたり、その平均含有率は支持体由来とアクリル樹脂層由来の二次イオンを比較して算出した。 The compound names described in the following table represent the following compounds.
Arton: Norbornene resin made by JSR Corporation,
Nylon 12: (Nylon-12, manufactured by Aldrich)
Polycarbonate: (Panlite L1225, manufactured by Teijin Limited)
Polyethylene terephthalate (PET): (Teleflex FT7, manufactured by Teijin Limited)
Polymethyl methacrylate (PMMA): (Dianar BR88, manufactured by Mitsubishi Rayon Co., Ltd.)
Polyimide: produced by referring to JP2012-233301 Ethylcellulose: (Etocel 100 cp, manufactured by Dow Chemical Japan)
Polystyrene-maleic anhydride: (D332, manufactured by NOVA Chemicals)
Polysulfone: (Product name Sumilite FS-1300, manufactured by Sumitomo Bakelite Co., Ltd.)
Pentaerythritol triacrylate: (KAYARAD PET30, manufactured by Nippon Kayaku Co., Ltd.)
1-O-allyl-α-p-galactopyranoside: (allyl α-D-galactopyranoside, manufactured by Aldrich)
Glycerol monomethacrylate: (Product name (Blemmer GLM), Company name (Nippon Oil Co., Ltd.))
Boron compound 1

Boron compound 2 Phenylboronic acid Aldrich

Boron compound 3 Potassium (4-vinylphenyl) trifluoroborate Aldrich

In measuring the intermediate layer, the average content was calculated by comparing secondary ions derived from the support and the acrylic resin layer.

[Evaluation of retardation film]
About each obtained retardation film, thickness, 25 degreeC, Re (550) of 60% relative humidity, 25 degreeC, 60% relative humidity Rth (550), black foreign material, suitability for bonding with a polarizer, haze, orientation The display performance and adhesion were evaluated.

(Measurement of black foreign matter)
A polarizing plate was produced from the obtained film as follows, and the retardation film side of the polarizing plate was bonded to glass to produce a sample. After the sample was placed under conditions of 60 ° C. and 90% RH for 40 days, the polarizing plate of the sample was peeled off from the glass, and the amount of black foreign matter adhering to the glass side was visually determined based on the following criteria.
A: Black foreign matter is not visible at all B: Black foreign matter is slightly visible C: Black foreign matter appears partly dark but there are more parts that are not visible D: Black foreign matter appears partly dark but visible Many E: Black foreign objects appear dark on the entire surface

Production of polarizing plate:
The produced retardation film samples of the respective examples were bonded using a polyvinyl alcohol polarizer and an adhesive, and on the opposite surface of the polarizer in the same manner, manufactured by Fuji Film Co., Ltd., Fujitac TD60UL. (Thickness 60 μm) was bonded to prepare polarizing plates. When bonding the retardation film and the polarizer, the surface of the support and the surface of the polarizer were bonded.

(Evaluation of bonding suitability with polarizer)
A cross cut test was performed by a method based on the peel test of JIS K 5600 (1999), and the results were evaluated according to the following evaluation items.
A: 0-5 cells were peeled off.
B: 6-15 squares peeled off.
C: 16-30 squares were peeled off.
D: 31-50 mass was peeled off.
E: 51 to 100 cells were peeled off.

(Measure haze)
The haze of the obtained film was measured according to JIS K-6714 using a haze meter “HGM-2DP” {manufactured by Suga Test Instruments Co., Ltd.}.

(Evaluation of orientation)
Each retardation film was sandwiched between polarizing plates in a crossed Nicol state, and a backlight was applied to determine whether or not the surface was uniform and visually judged according to the following criteria.
A: Unevenness is not seen and it looks very homogeneous.
B: Slight unevenness is seen.
C: Unevenness appears thin on the entire surface.
D: There is a portion where the unevenness appears thin on the entire surface, and a portion appears strong.
E: It looks strong and clear on the entire surface.

(Evaluation of display performance)
Production of liquid crystal display device:
An optical film taken out of a new-iPad [trade name; manufactured by Apple Inc.] equipped with an IPS mode liquid crystal cell and placed on the front side (display surface side) and rear side (backlight side) of the liquid crystal cell Was removed only on the front side (display surface side), and the surface glass surface of the liquid crystal cell was washed.
A polarizing plate with a retardation film was bonded to the display surface side surface of the IPS mode liquid crystal cell.
In this way, an IPS mode liquid crystal display device LCD was produced.

((Front contrast evaluation))
For each of the produced IPS mode liquid crystal display devices, the luminance at the time of black display and white display was measured using a measuring device (EZ-Contrast XL88, manufactured by ELDIM), and the front contrast ratio (CR) was calculated. However, the front contrast of any polarizing plate was stable between 950 and 1000.

((Viewing angle brightness evaluation))
For each of the IPS mode liquid crystal display devices produced above, a backlight was installed, and for each, using a measuring machine (EZ-Contrast XL88, manufactured by ELDIM),
The brightness at the time of black display was measured in a dark room, and the polar brightness of 0 to 80 ° and the azimuth angle of 0 to 360 ° were each 5 °, and the black brightness value of each point was evaluated according to the following criteria.
A: Maximum black luminance is 0.10 cd / m ² or less B: Maximum black luminance is 0.11 to 0.50 / m ²
C: Maximum black luminance is 0.51 to 1.00 cd / m ²
D: Maximum black luminance is 1.01 to 2.00 cd / m ²
E: Maximum black luminance exceeds 2.00 cd / m ²

(Evaluation of adhesion)
Each film is cut into 1 mm square cuts in a grid pattern, and adhesive tape (product name: cello tape (registered trademark) manufactured by Nichiban Co., Ltd.) is attached to the surface of the retardation layer, and then the adhesive tape is peeled off and visually observed. Was observed. At this time, the evaluation was performed based on the number of cells in the portion where the adhesion was not peeled / the number of cells in the region where the tape was attached.
A: 0-5 cells were peeled off.
B: Peeled 5 to 15 squares.
C: 15-30 mass was peeled off.
D: 30-50 cells were peeled off.
E: 50 to 100 cells were peeled off.

  From the table, the retardation film of the present invention is a film that regrets that the moisture has soaked into the adjacent layer as compared with the comparative example, and has excellent adhesion between the support and the retardation layer, and is included in the retardation layer. It can be seen that the orientation of the liquid crystal compound is excellent.

[Evaluation of liquid crystal display devices]
(Preparation of polarizing plate)
The retardation film sample of each Example produced above was bonded using a polyvinyl alcohol polarizer and an adhesive, and on the opposite surface of the polarizer in the same manner, manufactured by Fuji Film Co., Ltd. Fujitac TD60UL (thickness 60 μm) was bonded to prepare polarizing plates. When bonding the retardation film and the polarizer, the surface of the support and the surface of the polarizer were bonded.
In all cases, the retardation film was disposed between the liquid crystal cell and the polarizer when mounted on the liquid crystal display device.

  In addition, each produced said polarizing plate was used as a display surface side polarizing plate so that it might mention later. As a backlight side polarizing plate used in combination with this, Z-TAC (manufactured by Fuji Film Co., Ltd.) is formed on one surface of the polarizer, and Fujitac TD60UL (thickness 60 μm) is produced on the other surface by Fuji Film Co., Ltd. A polarizing plate produced by laminating each of was used. When mounted on a liquid crystal display device, a Z-TAC film was disposed between the liquid crystal cell and the polarizer.

(Preparation of liquid crystal cell)
An optical film taken out of a new-iPad [trade name; manufactured by Apple Inc.] equipped with an IPS mode liquid crystal cell and placed on the front side (display surface side) and rear side (backlight side) of the liquid crystal cell Was removed only on the front side (display surface side), and the surface glass surface of the liquid crystal cell was washed.

(Production of liquid crystal display device)
A polarizing plate with a retardation film was bonded to the display surface side surface of the IPS mode liquid crystal cell.
In this way, an IPS mode liquid crystal display device LCD was produced.
The produced LCD was returned to the new-iPad taken out, and the following evaluation was performed.

(Front contrast evaluation)
For each of the produced IPS mode liquid crystal display devices, the luminance at the time of black display and white display was measured using a measuring device (EZ-Contrast XL88, manufactured by ELDIM), and the front contrast ratio (CR) was calculated. However, the front contrast of any polarizing plate was stable between 950 and 1000.

(Viewing angle brightness evaluation)
For each of the IPS mode liquid crystal display devices produced above, a backlight was installed, and for each, using a measuring device (EZ-Contrast XL88, manufactured by ELDIM), the luminance during black display was measured in a dark room, and the polar angle When the black luminance value of each point was evaluated by 0 ° to 80 ° and an azimuth angle of 0 ° to 360 ° by 5 °, almost no light leaked at a black luminance of 0.1 cd / m ² or less in any part.

DESCRIPTION OF SYMBOLS 1 Support body 2 Intermediate | middle layer 3 (Meth) acrylic resin layer 4 Phase difference layer I1 Secondary ion intensity | strength I2 Secondary ion intensity | strength in an intermediate | middle layer

Claims (17)

Support, intermediate layer, (meth) acrylic resin layer mainly composed of a polymer having a product of moisture permeability and film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and 90% relative humidity for 24 hours And retardation layers adjacent to each other in the order,
The (meth) acrylic resin layer is a composition containing a (meth) acrylate monomer, and Y (carbon number) / M (elements other than carbon atoms and hydrogen atoms) constituting the (meth) acrylate monomer in the composition Number) is obtained by curing a composition that is 1.4 or more and less than 3.
The intermediate layer includes the main component of the support and the main component of the (meth) acrylic resin layer,
A retardation film, wherein the retardation layer includes a liquid crystal compound and the alignment state of the liquid crystal compound is fixed. The retardation film according to claim 1, wherein the main component of the support is selected from a cycloolefin polymer, a polystyrene polymer, a polycarbonate polymer, a polyester polymer, and a poly (meth) acrylate polymer. The retardation film according to claim 1, wherein the main component of the support is a cycloolefin-based polymer. The retardation film according to claim 1, wherein Y (carbon number) / M (number of elements other than carbon atoms and hydrogen atoms) is 1.8 or more and less than 2. 5. The retardation film according to claim 1, wherein the (meth) acrylic resin layer has a hydroxyl group. The retardation film according to claim 1, wherein the intermediate layer has a thickness of 0.1 to 10 μm. The retardation film according to claim 1, wherein the support satisfies the following formulas (1) and (2).
Formula (1) 80 <= Re (550) <= 150
Formula (2) 80 ≦ Rth (550) ≦ 150
(In the above formula, Re (550)及 beauty Rth (550), respectively, 25 ° C., shows the retardation value in the in-plane direction and the thickness direction retardation at a wavelength of 550nm at 60% relative humidity.) The retardation film according to claim 1, wherein the retardation film satisfies the following formula (3), formula (4), and formula (5).
Formula (3) 80 nm ≦ Re (550) ≦ 150 nm
Formula (4) −100 nm ≦ Rth (550) ≦ 10 nm
Formula (5) 0.05 ≦ | Rth / Re | ≦ 0.5
(In the above formula, Re (550)及 beauty Rth (550), respectively, 25 ° C., shows the retardation value in the in-plane direction and the thickness direction retardation at a wavelength of 550nm at 60% relative humidity.) The retardation film according to claim 1, wherein the retardation layer contains boron. In the thickness direction of the retardation layer, the retardation layer has a boron concentration in a region of 1 to 10% from the (meth) acrylic resin layer, and is in a region of 90 to 100% from the (meth) acrylic resin layer. The retardation film according to claim 1, wherein the retardation film has a concentration higher than that of boron. The retardation film according to claim 9 or 10, wherein the retardation layer comprises a compound having a boronic acid structure and an ethylenically unsaturated double bond. A method for producing a retardation film having a support, an intermediate layer, a (meth) acrylic resin layer, and a retardation layer adjacent to each other in this order,
On a support composed mainly of a polymer having a moisture permeability and a film thickness of 90 to 6500 g · μm / m ² when placed at 40 ° C. and a relative humidity of 90% for 24 hours, the (meth) acrylic resin layer Y (carbon number) / M (other than carbon atoms and hydrogen atoms) comprising a main component and a solvent having a solubility or swelling ability with respect to the main component of the support and a (meth) acrylate monomer, constituting the (meth) acrylate monomer Applying a composition having an element number) of 1.4 or more and less than 3, and curing the (meth) acrylate monomer;
A method for producing a retardation film, comprising: applying a composition containing a polymerizable liquid crystal compound on the (meth) acrylic resin layer and polymerizing the polymerizable liquid crystal compound. The solvent having a dissolving ability or a swelling ability with respect to the main component of the (meth) acrylic resin layer and the main component of the support is selected from at least one of cyclohexanone, methyl isobutyl ketone, toluene, and methylcyclohexane. A method for producing a retardation film. The (meth) acrylate monomer is cured so that the degree of cure of the (meth) acrylate monomer is 70% or less before applying the composition containing the polymerizable liquid crystal compound. A method for producing a retardation film. The manufacturing method of the retardation film of any one of Claims 12-14 including the process of extending | stretching the said support body. A polarizing plate comprising a retardation film according to any one of claims 1 to 1 1. The retardation film according to any one of claims 1 to 1 1, or comprising a polarizing plate according to claim 16, the liquid crystal display device.

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