JPWO2014065294A1 - Laminated body and manufacturing method thereof, retardation film, polarizing plate, and IPS liquid crystal panel - Google Patents

Abstract

A multilayer film (A) comprising a substrate (A1) and a layer (A2) of a non-liquid crystalline material having positive intrinsic birefringence in contact with the substrate (A1); and a non-liquid crystalline material having a negative intrinsic birefringence And a multilayer film (B) comprising a resin layer (B2) in contact with a layer (B1) of a non-liquid crystalline material having a negative intrinsic birefringence and a non-liquid crystalline property having a positive intrinsic birefringence. A surface of the material layer (A2) opposite to the substrate (A1) and a surface of the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence opposite to the resin layer (B2) A laminated body comprising a single adhesive layer interposed therebetween.

Description

  The present invention relates to a laminate including an optical element, a manufacturing method thereof, a retardation film, a polarizing plate, and an IPS liquid crystal panel.

  A liquid crystal display device has advantages such as high image quality, thinness, light weight, and low power consumption, and is widely used in televisions, personal computers, car navigators, and the like. In a liquid crystal display device, a liquid crystal cell is disposed between two polarizers (that is, an incident side polarizer and an output side polarizer) arranged so that transmission axes are orthogonal to each other, and a voltage is applied to the liquid crystal cell. The orientation of the liquid crystal molecules is changed to display an image on the screen.

  In a liquid crystal display device, a sufficient contrast is usually obtained when viewing a screen from a direction parallel to the transmission axis of a polarizer. However, when the screen is viewed obliquely from a direction that is not parallel to the transmission axis, the transmission axis of the incident-side polarizer and the transmission axis of the output-side polarizer are apparently not orthogonal, so that linearly polarized light is not completely blocked. Light leakage may occur. When light leakage occurs, sufficient black cannot be obtained and the contrast decreases. Therefore, in a liquid crystal display device, an attempt has been made to provide an optical compensation film in order to prevent a reduction in screen contrast.

  A retardation film is usually used as the optical compensation film. As for the retardation film, various techniques have been conventionally developed as shown in Patent Documents 1 to 10, for example.

Japanese Patent No. 3897743 Japanese Patent No. 3962034 Japanese Patent No. 3795512 Japanese Patent No. 4070510 Japanese Patent No. 4107741 Japanese Patent No. 4636622 Japanese Patent No. 4586326 Japanese Patent No. 4433854 Japanese Patent No. 4369222 Japanese Patent No. 2660601

  In recent years, touch panels have been widely used in portable terminals such as mobile phones and tablet personal computers. As the liquid crystal display device used for the touch panel, a display using an IPS (in-plane switching) type liquid crystal cell is preferable because there is no occurrence of display unevenness during use. In addition, as an optical compensation film used in a liquid crystal display device having an IPS type liquid crystal cell, a retardation film in which a plurality of retardation films having different optical characteristics are combined is usually used.

  With the recent thinning of mobile terminals, there is a demand for even thinner optical compensation films. However, since an optical compensation film used in a liquid crystal display device including an IPS type liquid crystal cell is a retardation film in which a plurality of retardation films are combined, it is difficult to reduce the thickness.

  As a specific example, generally, when the thickness of the retardation film is reduced, the retardation film is liable to be damaged. Therefore, it has been difficult to stably produce a thin optical compensation film. In particular, when bonding a plurality of thin retardation films, it was difficult to perform stable bonding while preventing damage to the retardation film. For this reason, it has been difficult to employ a production method preferable for industrial production such as a roll-to-roll method.

  Further, when the thickness of the retardation film is reduced, generally, the influence of the variation in the thickness of the retardation film on the optical performance tends to increase. Therefore, it is difficult to reduce the thickness of the optical compensation film while maintaining the optical compensation performance equivalent to that of the conventional product.

  The present invention was devised in view of the above-described problems, and provides a laminate and a method for producing the same that can achieve a retardation film having desired optical performance, a thin thickness, and capable of stable production. An object of the present invention is to provide a retardation film having a desired optical performance, a thin thickness and capable of stable production, and a polarizing plate and an IPS liquid crystal panel provided with the retardation film.

As a result of intensive studies to solve the above problems, the present inventor has found that the base film (A1) and the multilayer film (A) including the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence and the intrinsic birefringence are A multilayer film (B) comprising a negative non-liquid crystalline material layer (B1) and a resin layer (B2), a surface of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence, and the intrinsic birefringence Is a laminate having a single adhesive layer interposed between the surface of the negative non-liquid crystalline material layer (B1) and having a desired optical performance, a thin thickness, and a stable production. The present inventors have found that a possible retardation film can be realized and completed the present invention.
That is, the present invention is as follows.

[1] A multilayer film (A) comprising a substrate (A1) and a layer (A2) of a non-liquid crystalline material having a positive intrinsic birefringence in contact with the substrate (A1);
A multilayer film (B1) comprising a non-liquid crystalline material layer (B1) having a negative intrinsic birefringence and a resin layer (B2) in contact with the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence )When,
The surface of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence opposite to the base (A1) and the resin in the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence A single adhesive layer interposed between the surface opposite to the layer (B2);
A laminate comprising:
[2] The laminate according to [1], wherein a peeling force between the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence and the resin layer (B2) is 0.5 N / 20 mm or less. .
[3] The peel force between the substrate (A1) and the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence is 0.05 N / 20 mm or less, [1] or [2] The laminated body of description.
[4] The difference between the glass transition temperature of the material of the substrate (A1) and the glass transition temperature of the non-liquid crystalline material having a positive intrinsic birefringence is in the range of + 15 ° C. to −15 ° C. [1] -The laminated body as described in any one of [3].
[5] The relationship between the glass transition temperature Tg (B1) of the non-liquid crystalline material having a negative intrinsic birefringence and the glass transition temperature Tg (B2) of the resin of the resin layer (B2) is Tg (B1)> Tg. (B2) The laminate according to any one of [1] to [4], which satisfies + 20 ° C.
[6] The laminate according to any one of [1] to [5], wherein the layer (B1) of the non-liquid crystalline material having negative intrinsic birefringence has a tensile elongation at break of 20% or less.
[7] Polymer resin, (meth) acrylic resin, polycarbonate resin, (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and polyethersulfone resin in which base material (A1) has an alicyclic structure The laminate according to any one of [1] to [6], which is formed of a resin selected from the group consisting of:
[8] The non-liquid crystalline material having a positive intrinsic birefringence is selected from the group consisting of a polyimide resin, a maleimide resin, a polyamideimide resin, a polycarbonate resin, a polyester resin, and a polyurethane urea resin. [1] to [7] The laminate according to any one of the above.
[9] A heavy polymer obtained by polymerizing one or more monomers selected from the group consisting of styrenes, styrenes-maleic acid, maleimides, and (meth) acrylic acid esters, with the non-liquid crystalline material having a negative intrinsic birefringence. The mixture, and a mixture containing at least one polymer selected from the group consisting of a polycarbonate polymer, a polyester polymer, and a polyarylene ether polymer, according to any one of [1] to [8]. Laminated body.
[10] The resin layer (B2) is a polymer resin having an alicyclic structure, (meth) acrylic resin, polycarbonate resin, (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and polyethersulfone. The laminate according to any one of [1] to [9], which is formed of a resin selected from the group consisting of resins.
[11] A method for producing a laminate according to any one of [1] to [10],
Developing a solution prepared by dissolving a non-liquid crystalline material having a positive intrinsic birefringence in a solvent on the substrate (A1);
Drying the developed solution;
Stretching the substrate (A1) after drying the solution to obtain the multilayer film (A);
Manufacturing method.
[12] A method for producing a laminate according to any one of [1] to [10],
The non-liquid crystalline material having a negative intrinsic birefringence and the resin forming the resin layer (B2) are coextruded to form the resin layer (B2) and the non-liquid crystalline material layer having a negative intrinsic birefringence (B1). And a step of obtaining a multilayer film (b) comprising the resin layer (B2) in this order;
Stretching the multilayer film (b);
Peeling the one resin layer (B2) from the stretched multilayer film (b) to obtain the multilayer film (B);
Manufacturing method.
[13] A method for producing a laminate according to any one of [1] to [10],
The surface of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence opposite to the base (A1) and the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence. A step of forming the adhesive layer on one surface of the surface opposite to the resin layer (B2);
Bonding the adhesive layer and the other surface on which the adhesive layer is not formed;
Manufacturing method.
[14] A retardation film in which the substrate (A1) and the resin layer (B2) are peeled from the laminate according to any one of [1] to [10].
[15] A polarizing plate comprising a polarizer and the retardation film according to [14].
[16] An IPS liquid crystal panel comprising an IPS liquid crystal cell and the polarizing plate according to [15].

  According to the present invention, a laminate having a desired optical performance, a thin thickness, and capable of realizing a retardation film that can be stably produced, and a method for producing the same, have a desired optical performance, It is possible to provide a retardation film having a thin thickness and capable of stable production, and a polarizing plate and an IPS liquid crystal panel including the retardation film.

FIG. 1 is a diagram schematically showing a cross section of a laminated body according to an embodiment of the present invention, taken along a plane perpendicular to the main surface. FIG. 2 is a schematic view schematically showing an example of a production apparatus for producing the multilayer film (A). FIG. 3 is a schematic view schematically showing an example of a production apparatus for producing the multilayer film (b). FIG. 4 is a schematic view schematically showing an example of an apparatus for producing a laminate by laminating a multilayer film (A) and a multilayer film (B). FIG. 5 is a diagram schematically showing a cross section of the polarizing plate according to one embodiment of the present invention, taken along a plane perpendicular to the main surface. FIG. 6 is a diagram schematically showing a cross section of the liquid crystal panel according to one embodiment of the present invention, taken along a plane perpendicular to the main surface.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be arbitrarily modified within the scope of the claims of the present invention and its equivalents.

In the following description, “long” means one having a length of at least 5 times the width, preferably 10 times or more, specifically a roll shape. It has a length enough to be wound up and stored or transported.
The “base material” and the “polarizing plate” include not only rigid members but also flexible members such as resin films.

  Further, the retardation in the in-plane direction of the film is a value represented by (nx−ny) × d unless otherwise specified. The retardation in the thickness direction of the film is a value represented by {| nx + ny | / 2−nz} × d unless otherwise specified. Here, nx represents a refractive index in a direction (in-plane direction) perpendicular to the thickness direction of the film and giving the maximum refractive index. ny represents the refractive index in the in-plane direction and orthogonal to the nx direction. nz represents the refractive index in the thickness direction. d represents the thickness of the film. These retardations can be measured using a commercially available phase difference measuring device (for example, “KOBRA-21ADH” manufactured by Oji Scientific Instruments, “WPA-micro” manufactured by Photonic Lattice) or the Senarmon method.

Further, “(meth) acrylate” means “acrylate” or “methacrylate”, “(meth) acryl” means “acryl” or “methacryl”, and “(meth) acrylonitrile”. The term “acrylonitrile” or “methacrylonitrile” means.
“Ultraviolet light” means light having a wavelength of 1 nm or more and 400 nm or less.

  In addition, the directions of the elements “parallel”, “vertical”, and “orthogonal” may include errors within a range that does not impair the effects of the present invention, for example, ± 5 °, unless otherwise specified. Good. Further, “along” in a certain direction means “in parallel” in a certain direction.

  Further, the MD direction (machine direction) is a film flow direction in the production line, and is usually parallel to the longitudinal direction and the longitudinal direction of the long film. Further, the TD direction (traverse direction) is a direction parallel to the film surface and perpendicular to the MD direction, and is usually parallel to the width direction and the lateral direction of the long film.

  Further, positive intrinsic birefringence means that the refractive index in the stretching direction is larger than the refractive index in the direction orthogonal to the stretching direction, and negative intrinsic birefringence means that the refractive index in the stretching direction is negative. It means that the refractive index is smaller than the refractive index in the direction orthogonal to the stretching direction. The value of intrinsic birefringence can also be calculated from the dielectric constant distribution.

  In the polymer described below, unless otherwise specified, the proportion of the structural unit contained in the polymer is usually the ratio of the monomer corresponding to the structural unit in all monomers of the polymer ( It matches the charging ratio).

[1. Laminate]
FIG. 1 is a diagram schematically showing a cross section of a laminated body according to an embodiment of the present invention, taken along a plane perpendicular to the main surface. As shown in FIG. 1, the laminate 100 includes a multilayer film (A) 10, a multilayer film (B) 20, an adhesive layer that bonds the multilayer film (A) 10 and the multilayer film (B) 20. 30.

[1.1. Multilayer film (A)]
As shown in FIG. 1, the multilayer film (A) 10 includes a base material (A1) 11 and a layer (A2) 12 of a non-liquid crystalline material. Since the non-liquid crystal material layer (A2) 12 is in contact with the base material (A1) 11, other layers are provided between the base material (A1) 11 and the non-liquid crystal material layer (A2) 12. It is not done.

[1.1.1. Substrate (A1)]
As the substrate (A1), a resin film is usually used. Although the kind of resin which forms a base material (A1) is not specifically limited, Transparent resin is preferable. Here, the term “transparent” means that it has a light transmittance suitable for use in an optical member. For example, the total light transmittance measured using a test piece having a thickness of 1 mm is usually 70% or more, preferably 80. % Or more, particularly preferably 90% or more. The upper limit of the total light transmittance is usually 100%. The total light transmittance can be measured using a spectrophotometer (manufactured by JASCO Corporation, ultraviolet-visible near-infrared spectrophotometer “V-570”) in accordance with JIS K0115.

  Examples of the resin that forms the base material (A1) include polyolefin resins such as polyethylene resins and polypropylene resins; polymer resins having an alicyclic structure such as norbornene-based resins; polyimide resins, polyamideimide resins, and polyamides. Resin, polyetherimide resin, polyether ether ketone resin, polyether ketone resin, polyketone sulfide resin, polyether sulfone resin, polysulfone resin, polyphenylene sulfide resin, polyphenylene oxide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate Resin, polyacetal resin, polycarbonate resin, polyarylate resin, (meth) acrylic resin, polyvinyl alcohol resin, polypropylene resin, cellulose System resin, epoxy resin, phenol resin, (meth) acrylic acid ester - vinyl aromatic compound copolymer resins, isobutene / N- methylmaleimide copolymer resins, styrene / acrylonitrile copolymer resins. One of these may be used alone, or two or more of these may be combined in any ratio. For example, isobutene / N-methylmaleimide copolymer resin and styrene / acrylonitrile copolymer resin are preferably used in combination as a mixture.

  Among these, a polymer resin having an alicyclic structure, a (meth) acrylic resin, a polycarbonate resin, a (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and a polyethersulfone resin are selected. Preferred is a resin. These resins are excellent in mechanical strength and can reduce the retardation developed by stretching.

  The polymer resin having an alicyclic structure is a resin containing a polymer having an alicyclic structure. Further, the polymer having an alicyclic structure is a polymer having a structural unit containing an alicyclic structure as a structural unit of the polymer, a polymer having an alicyclic structure in the main chain, and a side chain. Any polymer having an alicyclic structure can be used. Moreover, the polymer which has an alicyclic structure may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Among these, a polymer containing an alicyclic structure in the main chain is preferable from the viewpoint of mechanical strength, heat resistance, and the like.

  Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure. Among these, from the viewpoints of mechanical strength, heat resistance and the like, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is particularly preferable.

  The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, particularly preferably per alicyclic structure. Is a range of 15 or less. Thereby, mechanical strength, heat resistance, and film formability are highly balanced, which is preferable.

  The ratio of the structural unit containing an alicyclic structure in the polymer having an alicyclic structure can be appropriately selected according to the purpose of use. Specifically, this ratio is preferably 55% by weight or more, more preferably 70% by weight or more, particularly preferably 90% by weight or more, and usually 100% by weight or less. It is preferable from a heat resistant viewpoint that the ratio of the structural unit containing the alicyclic structure in the polymer which has an alicyclic structure exists in this range.

  Examples of the polymer having an alicyclic structure include a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer, and hydrides thereof. Can be mentioned. Among these, norbornene-based polymers are preferable because of good moldability.

  Examples of the norbornene-based polymer include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and an arbitrary monomer, or a hydride thereof; An addition polymer of a monomer having a norbornene structure, an addition copolymer of a monomer having a norbornene structure and an arbitrary monomer, or a hydride thereof can be given. Among these, a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of moldability, heat resistance, low hygroscopicity, dimensional stability, lightness, and the like. Here, “(co) polymer” refers to a polymer and a copolymer.

  Examples of the monomer having a norbornene structure include bicyclo [2.2.1] hept-2-ene (common name: norbornene), tricyclo [4.3.0.12,5] deca-3,7- Diene (common name: dicyclopentadiene), 7,8-benzotricyclo [4.3.0.12,5] dec-3-ene (common name: methanotetrahydrofluorene), tetracyclo [4.4.0. 12, 5.17,10] dodec-3-ene (common name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent in the ring). Here, examples of the substituent include an alkyl group, an alkylene group, and a polar group. Moreover, these substituents may be the same or different, and a plurality thereof may be bonded to the ring. Moreover, the monomer which has a norbornene structure may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Examples of an optional monomer capable of ring-opening copolymerization with a monomer having a norbornene structure include, for example, monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof; and cyclic conjugates such as cyclohexadiene and cycloheptadiene. Dienes and derivatives thereof; and the like. As the optional monomer capable of ring-opening copolymerization with a monomer having a norbornene structure, one kind may be used alone, or two or more kinds may be used in combination at any ratio.

  A ring-opening polymer of a monomer having a norbornene structure, and a ring-opening copolymer of any monomer copolymerizable with a monomer having a norbornene structure are, for example, a known ring-opening monomer. It can be produced by polymerization or copolymerization in the presence of a polymerization catalyst.

  Examples of the optional monomer that can be addition copolymerized with a monomer having a norbornene structure include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof; cyclobutene and cyclopentene. And cycloolefins such as cyclohexene and derivatives thereof; non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene; and the like. Among these, α-olefin is preferable and ethylene is more preferable. Moreover, the arbitrary monomer which can carry out addition copolymerization with the monomer which has a norbornene structure may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  An addition copolymer of a monomer having a norbornene structure and an addition copolymer of any monomer that can be copolymerized with a monomer having a norbornene structure include, for example, a monomer of a known addition polymerization catalyst. It can be produced by polymerization or copolymerization in the presence.

  Examples of the monocyclic olefin polymer include addition polymers of a cyclic olefin monomer having a single ring such as cyclohexene, cycloheptene, and cyclooctene.

  Examples of the cyclic conjugated diene polymer include polymers obtained by cyclization reaction of addition polymers of conjugated diene monomers such as 1,3-butadiene, isoprene and chloroprene; cyclic conjugates such as cyclopentadiene and cyclohexadiene. And 1,2- or 1,4-addition polymers of diene monomers; and their hydrides.

  Examples of vinyl alicyclic hydrocarbon polymers include polymers of vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane and their hydrides; vinyl aromatic hydrocarbons such as styrene and α-methylstyrene. Hydrogenated product obtained by hydrogenating an aromatic ring portion contained in a polymer obtained by polymerizing a monomer, a vinyl alicyclic hydrocarbon monomer, or a vinyl aromatic hydrocarbon monomer and these vinyl aromatic hydrocarbon monomers. On the other hand, a hydride of an aromatic ring of a copolymer such as a random copolymer or a block copolymer with an arbitrary copolymerizable monomer can be used. Examples of the block copolymer include a diblock copolymer, a triblock copolymer or a multi-block copolymer having more than that, a gradient block copolymer, and the like.

  The (meth) acrylic resin is a resin containing a (meth) acrylic polymer. The (meth) acrylic polymer means a polymer of (meth) acrylic acid or a (meth) acrylic acid derivative. Examples of the (meth) acrylic polymer include homopolymers and copolymers such as acrylic acid, acrylic acid ester, acrylamide, acrylonitrile, methacrylic acid, and methacrylic acid ester. Moreover, a (meth) acrylic polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Since the (meth) acrylic resin has high strength and is hard, the strength of the laminate can be increased.

  As the (meth) acrylic polymer, a polymer containing a structural unit formed by polymerizing a (meth) acrylic acid ester is preferable. Examples of (meth) acrylic acid esters include alkyl esters of (meth) acrylic acid. Among them, those having a structure derived from (meth) acrylic acid and an alkanol having 1 to 15 carbon atoms or cycloalkanol are preferable, and those having a structure derived from an alkanol having 1 to 8 carbon atoms are more preferable. .

  Specific examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, sec-butyl acrylate, and t-acrylate. -Butyl, n-hexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl acrylate, and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  Specific examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, sec-butyl methacrylate, methacrylic acid. Examples thereof include t-butyl acid, n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, and n-dodecyl methacrylate. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  Furthermore, the (meth) acrylic acid ester may have a substituent such as a hydroxyl group or a halogen atom as long as the effects of the present invention are not significantly impaired. Examples of the (meth) acrylic acid ester having such a substituent include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-methacrylic acid 2- Examples include hydroxypropyl, 4-hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, and glycidyl methacrylate. Moreover, these substituents may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Further, the (meth) acrylic polymer may be a polymer of only (meth) acrylic acid or (meth) acrylic acid derivatives, and can be copolymerized with (meth) acrylic acid or (meth) acrylic acid derivatives. It may be a copolymer with any arbitrary monomer. Examples of the optional monomer include α, β-ethylenically unsaturated carboxylic acid ester monomers other than (meth) acrylic acid esters, α, β-ethylenically unsaturated carboxylic acid monomers, and alkenyls. Aromatic monomers, conjugated diene monomers, non-conjugated diene monomers, carboxylic acid unsaturated alcohol esters, olefin monomers, and the like can be mentioned. Moreover, arbitrary monomers may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  However, the proportion of structural units having a structure formed by polymerizing (meth) acrylic acid or (meth) acrylic acid derivatives in the (meth) acrylic polymer is preferably 55% by weight or more, more preferably 70% by weight. % Or more, particularly preferably 90% by weight or more, and usually 100% by weight or less.

  Of these acrylic polymers, polymethacrylate is preferred, and polymethyl methacrylate is more preferred.

  The polycarbonate resin is a resin containing a polycarbonate polymer. The polycarbonate polymer is a polymer having structural units bonded by a carbonate bond (—O—C (═O) —O—). A polycarbonate polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Among them, the polycarbonate polymer is preferably one containing a structural unit represented by the following formula (I). The structural unit represented by the following formula (I) can be formed by polymerizing bisphenol Z, for example. Examples of such a resin containing a polycarbonate polymer include Lexan manufactured by SABIC.

In formula (I), R ^{1 to} R ⁸ each independently represent a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, or an aryl group. The alkyl group, cycloalkyl group, and aryl group may be substituted or unsubstituted. Furthermore, the number of carbon atoms of the alkyl group, cycloalkyl group, or aryl group is usually 1-10.
In the formula (I), R ⁹ represents a hydrogen atom, an alkyl group or an aryl group. Here, the carbon atom number of an alkyl group and an aryl group is 1-9 normally.
In formula (I), Z is a residue that, together with the carbon atom to which it is attached, forms a saturated or unsaturated carbocycle having 4 to 11 carbon atoms. Among them, Z is preferably a saturated carbocyclic ring having 6 carbon atoms.

Among those described above, R ¹ or R ³ is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group. R ⁶ or R ⁸ is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group.
Among them, the structural unit represented by the formula (I) is particularly preferably a structural unit represented by the chemical formula (II) (bisphenol Z unit).

  As the polycarbonate polymer, those further containing a structural unit represented by the following formula (III) in addition to the structural unit represented by the formula (I) are preferable. The structural unit represented by the following formula (III) can be formed by polymerizing bisphenol A, for example. Among these, the structural unit represented by the formula (III) is more preferably a structural unit represented by the formula (IV) or (V).

In the chemical formula (III), R ^{10 to} R ¹⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, or an aryl group. Here, the alkyl group, cycloalkyl group, and aryl group may be substituted or unsubstituted. Furthermore, the carbon atom number of an alkyl group, a cycloalkyl group, and an aryl group is 1-10 normally.

  In the combination of the structural unit represented by the formula (I) and the structural unit represented by the formula (III), the amount of the structural unit represented by the formula (III) is preferably 0 with respect to 1 mol of the structural unit represented by the formula (I). .6 mol or more, and preferably 1.5 mol or less. Thereby, a film excellent in heat resistance and flexibility can be formed as the substrate (A1).

  Moreover, the polycarbonate polymer may contain arbitrary structural units other than the structural unit shown in Formula (I) or Formula (III). However, in the polycarbonate polymer, the proportion of the structural unit represented by formula (I) or formula (III) is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. Usually, it is 100% by weight or less.

  The (meth) acrylic acid ester-vinyl aromatic compound copolymer resin is a resin containing a copolymer of a (meth) acrylic acid ester and a vinyl aromatic compound. The (meth) acrylic acid ester and the vinyl aromatic compound may be used one by one or may be copolymerized by combining two or more of them at an arbitrary ratio. Moreover, the said copolymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Examples of the (meth) acrylic acid ester include the same examples as those exemplified in the description of the (meth) acrylic resin. Moreover, (meth) acrylic acid ester may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Examples of vinyl aromatic compounds include aromatic monomers having an ethylenically unsaturated bond. Specific examples thereof include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, α-methylstyrene, vinylnaphthalene, and vinylanthracene. Can be mentioned. Moreover, a vinyl aromatic compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The polymerization ratio of (meth) acrylic acid ester to vinyl aromatic compound is 1% to 80% by weight of (meth) acrylic acid ester, vinyl aromatic compound from the viewpoint of heat resistance, transparency and strength of the copolymer. It may be 20% to 99% by weight. By making the amount of (meth) acrylic acid ester 1% by weight or more, the strength, heat resistance and transparency of the copolymer can be sufficiently increased, and by making it 80% by weight or less, (meth) acrylic acid ester -The moldability of the vinyl aromatic compound copolymer resin can be improved.

  The copolymer of (meth) acrylic acid ester and vinyl aromatic compound may be a copolymer obtained by further polymerizing any monomer other than (meth) acrylic acid ester and vinyl aromatic compound. As an arbitrary monomer, a conjugated diene compound can be mentioned, for example. Specific examples of the conjugated diene compound include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3- Examples include hexadiene, and particularly preferred are 1,3-butadiene and isoprene. One of these may be used alone, or two or more thereof may be used in combination at any ratio. However, in this copolymer, the proportion of structural units having a structure formed by polymerizing (meth) acrylic acid ester or vinyl aromatic compound is preferably 55% by weight or more, more preferably 70% by weight or more, Particularly preferred is 90% by weight or more, and usually 100% by weight or less.

  The polyethersulfone resin is a resin containing a polyethersulfone polymer. The polyethersulfone polymer is a polymer in which the main chain is linked by a condensed structure of aromatic bisphenol and dihalogenoarylsulfone. The polyethersulfone polymer can be obtained, for example, by polycondensing aromatic bisphenol and dihalogenoarylsulfone in the presence of a basic catalyst by a polymerization method such as a solution polymerization method or a melt polymerization method. A polyether sulfone polymer may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.

  Examples of the aromatic bisphenol include hydroquinone, 4,4′-dihydroxybiphenyl, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethyl. Cyclohexane, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -1 -Phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2 -Bis (4-hydroxy-3-tert-butylphenyl) propane, 9,9-bis (4-hydro) Ciphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 1,3-bis {2- (4-hydroxyphenyl) propyl} benzene, 1,4-bis {2- (4- Hydroxyphenyl) propyl} benzene, 2,2-bis (4-hydroxyphenyl) -1,1,1-3,3,3-hexafluoropropane and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  Examples of the dihalogenoaryl sulfone include bis (4-chlorophenyl) sulfone, bis (4-fluorophenyl) sulfone, bis (4-bromophenyl) sulfone, and 4-chloro-4 ′-(p-chlorophenyl) diphenyl. Sulfone, 4-fluoro-4 ′-(p-fluorophenyl) diphenylsulfone, 4-bromo-4 ′-(p-bromophenyl) diphenylsulfone, bis (4′-chlorobiphenyl) sulfone, bis (4′-fluoro) Biphenyl) sulfone, bis (4′-bromobiphenyl) sulfone, bis (6-chlorobinaphthyl) sulfone, bis (6-fluorobinaphthyl) sulfone, bis (6-bromobinaphthyl) sulfone, bis (4-chloro-3-methyl) Phenyl) sulfone, bis (4-fluoro-3-methylpheny) ) Sulfone, bis (4-bromo-3-methylphenyl) sulfone, bis (3-phenyl-4-chlorophenyl) sulfone, bis (3-phenyl-4-fluorophenyl) sulfone, bis (3-phenyl-4-bromo) Phenyl) sulfone, bis (4-chloro-3-t-butylphenyl) sulfone, bis (4-fluoro-3-t-butylphenyl) sulfone, bis (4-bromo-3-t-butylphenyl) sulfone, etc. Can be mentioned. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  The polyethersulfone polymer may contain an arbitrary structural unit having a structure formed by polymerizing monomers other than aromatic bisphenol and dihalogenoarylsulfone. However, in this copolymer, the proportion of structural units having a structure formed by polymerizing aromatic bisphenol and dihalogenoaryl sulfone is preferably 55% by weight or more, more preferably 70% by weight or more, particularly preferably. It is 90% by weight or more and usually 100% by weight or less.

  Resin used as a material which forms a base material (A1) can contain arbitrary components other than the polymer mentioned above. However, the ratio of the above-mentioned polymer in the resin that is a material for forming the substrate (A1) is preferably 50% by weight or more, more preferably 80% by weight or more, and particularly preferably 90% by weight or more, and is usually 100%. % By weight or less.

  For example, when the substrate (A1) is a (meth) acrylic resin, the (meth) acrylic resin can include rubber particles. By including the rubber particles, the flexibility of the (meth) acrylic resin can be increased, and the impact resistance of the laminate can be improved. Further, if necessary, the surface roughness of the (meth) acrylic resin layer can be increased with rubber particles, the contact area on the surface can be reduced, and the slipperiness of the surface can be enhanced. In the base material (A1), it is preferable that the surface of the non-liquid crystalline material layer (A2) side has a small surface roughness, and therefore the surface roughness of the surface opposite to the non-liquid crystalline material layer (A2). It is preferable to roughen the thickness.

  Examples of the rubber forming the rubber particles include acrylate polymer rubber, polymer rubber mainly composed of butadiene, and ethylene-vinyl acetate copolymer rubber. Examples of the acrylate polymer rubber include those having butyl acrylate, 2-ethylhexyl acrylate or the like as a main component of a monomer unit. Among these, acrylic acid ester polymer rubber mainly composed of butyl acrylate and polymer rubber mainly composed of butadiene are preferable.

  Further, the rubber particles may contain one type of rubber alone or two or more types of rubber. Further, these rubbers may be mixed uniformly, but may be layered. Examples of rubber particles in which rubber is layered include particles in which a core made of a rubber elastic component and a hard resin layer (shell) form a layer with a core-shell structure. Here, examples of the rubber elastic component include a rubber elastic component obtained by grafting an alkyl acrylate such as butyl acrylate and styrene. Examples of the hard resin layer include a hard resin layer made of a copolymer of one or both of polymethyl methacrylate and methyl methacrylate and an alkyl acrylate.

  The rubber particles preferably have a number average particle diameter of 0.05 μm or more, more preferably 0.1 μm or more, and preferably 0.3 μm or less, and 0.25 μm or less. Is more preferable. By setting the number average particle diameter within the above range, moderate unevenness can be formed on the surface of the (meth) acrylic resin layer, and the slipperiness of the laminate can be improved.

  The amount of the rubber particles is preferably 5 parts by weight or more and preferably 50 parts by weight or less with respect to 100 parts by weight of the (meth) acrylic polymer. By setting the amount of the rubber particles within the above range, the impact resistance of the laminate can be increased and the handling property can be improved.

  Moreover, as an arbitrary component which resin which becomes the material which forms a base material (A1) can contain, a compounding agent is mentioned, for example. Examples of compounding agents are layered crystal compounds; fine particles; antioxidants, heat stabilizers, light stabilizers, weathering stabilizers, UV absorbers, near infrared absorbers and other stabilizers; plasticizers: dyes and pigments, etc. Colorants; antistatic agents; and the like. Moreover, a compounding agent may use one type and may use it combining two or more types by arbitrary ratios. The amount of the compounding agent can be appropriately determined within a range that does not significantly impair the effects of the present invention. For example, the amount is preferably 10 parts by weight or less, more preferably 5 parts by weight or less with respect to 100 parts by weight of the polymer. Preferably, it is more preferably 3 parts by weight or less, and usually 0 part by weight or more.

  It is preferable to set the glass transition temperature of resin used as the material for forming the substrate (A1) according to the glass transition temperature of the non-liquid crystalline material forming the layer (A2). Specifically, the difference between the glass transition temperature of the material of the substrate (A1) and the glass transition temperature of the non-liquid crystalline material forming the layer (A2) is preferably −15 ° C. or more, more preferably −10. ° C or higher, particularly preferably −5 ° C. or higher, preferably + 15 ° C. or lower, more preferably + 10 ° C. or lower, and particularly preferably + 5 ° C. or lower. By making the difference in glass transition temperature of the material forming each layer in the multilayer film (A) within the above range, the followability of the layer (A2) of the non-liquid crystalline material with respect to the base material (A1) during the stretching treatment can be improved. Stretching can be performed without loss. Thereby, uniform stretching treatment can be performed on the layer (A2) of the non-liquid crystalline material in both the MD direction and the TD direction.

The substrate (A1) has an in-plane retardation Re _A1 (550) at a wavelength of 550 nm, preferably 300 nm or less, more preferably 200 nm or less, particularly preferably 100 nm or less, and usually 0 nm or more. By reducing the retardation Re _A1 (550) in the in-plane direction of the substrate (A1), only the layer (A2) of the non-liquid crystalline material is stretched while being stretched when the multilayer film (A) is produced. It becomes possible to measure retardation. In particular, the substrate (A1) is preferably one having optical isotropy.

  As a base material (A1), what gave surface treatments, such as a hydrophilization process, a hydrophobization process, the process which reduces the solubility of a base material (A1), can be used as needed.

  The base material (A1) may have a single layer structure formed of only one layer, or may have a multilayer structure including two or more layers.

  The thickness of the substrate (A1) is preferably 10 μm or more, more preferably 20 μm or more, particularly preferably 30 μm or more, preferably 200 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less. By setting the thickness of the base material (A1) to be equal to or more than the lower limit value of the above range, the occurrence of uneven stretching can be prevented. Moreover, industrial productivity can be improved by setting it as below an upper limit so that the tension | tensile_strength of a base material (A1) may not become excessive.

[1.1.2. Non-liquid crystalline material layer (A2)]
The layer (A2) of non-liquid crystalline material is a layer of non-liquid crystalline material having a positive intrinsic birefringence. Unlike the liquid crystalline material, the non-liquid crystalline material is transparent when applied to the surface of the base material (A1) due to the properties of the non-liquid crystalline material itself, regardless of the orientation of the base material (A1). A non-oriented layer can be formed. Thereafter, by stretching the multilayer film (A), a layer (A2) of a non-liquid crystalline material oriented in the same direction as an arbitrary stretching direction can be formed. For this reason, even if the said base material (A1) is a non-orientation thing, the process of coating the orientation film on the surface, the process of laminating the orientation film, etc. are not required, for example.

  As the non-liquid crystalline material having a positive intrinsic birefringence, a resin having a positive intrinsic birefringence is usually used. Further, as this resin, a transparent resin is usually used. Preferred examples of such resins include polyamide resins, polyimide resins, maleimide resins, polyester resins, polyetherketone resins, polyamideimides because of their excellent heat resistance, chemical resistance, transparency, and rigidity. Resins, polycarbonate resins, polyester imide resins, polyurethane urea resins and the like can be mentioned. One of these may be used alone, or two or more of these may be used in combination at any ratio. When two or more kinds of resins are combined, resins having different functional groups such as a mixture of a polyether ketone resin and a polyamide resin may be used in combination. Among such resins, polyimide resin, maleimide resin, polyamideimide resin, polycarbonate resin and polyester resin, and polyurethane urea resin are preferable. Specific examples include those described in Japanese Patent No. 3962034, Japanese Patent No. 3897743, Japanese Patent No. 3838522, and Japanese Patent No. 3811175.

  As a preferable polyimide resin, for example, a resin containing a polyimide having a high in-plane orientation and soluble in an organic solvent is preferable. Specifically, for example, it includes a condensation polymerization product of 9,9-bis (aminoaryl) fluorene and an aromatic tetracarboxylic dianhydride disclosed in JP 2000-511296 A, and has the following formula ( A resin containing polyimide containing at least one structural unit shown in VI) per molecule is preferred.

In formula (VI), each R ^1a independently represents a hydrogen atom; a halogen atom; a phenyl group; a phenyl group substituted with 1 to 4 halogen atoms or an alkyl group having 1 to 10 carbon atoms; and And a group selected from the group consisting of: an alkyl group having 1 to 10 carbon atoms; Among them, as R ^1a , a halogen atom; a phenyl group; a phenyl group substituted with 1 to 4 halogen atoms or an alkyl group having 1 to 10 carbon atoms; and an alkyl group having 1 to 10 carbon atoms; Are preferably selected from.

In the formula (VI), A ^a represents a tetrasubstituted aromatic group having 6 to 20 carbon atoms. Among these Examples ^{A a,} preferably any of the groups of the following (1) to (3).
(1) A tetravalent group having a structure in which a hydrogen atom is removed from each of four carboxyl groups of pyromellitic acid.
(2) A tetravalent group having a structure in which four hydrogen atoms are removed from a polycyclic aromatic compound such as naphthylene, fluorenylene, benzofluorenylene, anthracenylene, or the like, and a substituted derivative thereof. Here, the substituent is an alkyl group having 1 to 10 carbon atoms and a fluorinated derivative thereof, and a halogen atom such as fluorine or chlorine.
(3) A group represented by the formula (VII).

In the formula (VII), ^Ba is a covalent bond, C (R ^2a ) ₂ group, CO group, O atom, S atom, SO ₂ group, Si (C ₂ H ₅ ) ₂ group, N (R ^3a ) ₂ Groups and combinations thereof are shown. R ^2a independently represents a hydrogen atom or a C (R ^4a ) ₃ group. R ^3a independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R ^4a independently represents a hydrogen atom, a fluorine atom or a chlorine atom. In formula (VII), m represents an integer of 1 to 10.

  Preferred maleimide resins include, for example, resins containing a polymer represented by formula (VIII).

In the formula (VIII), R ^b and Q ^b each independently represent a substituted or unsubstituted aliphatic group, aromatic group, heterocyclic group, siloxane group or unsaturated hydrocarbon group.
In the formula (VIII), ^Xb represents a maleimide group capable of active energy ray curing or heat curing.
In the formula (VIII), n represents an integer of 1 or more and 10 or less.

  Among the polymers represented by the formula (VIII), a polymer having a structure represented by the following formula (IX) or formula (X) is preferable. In the formula (IX) and the formula (X), n independently represents an integer of 1 or more and 10 or less.

Furthermore, examples of the maleimide resin include compounds described in US Patent Application Publication No. 2008/0075961.
These maleimide resins can be obtained from, for example, Air Brown.

  Examples of the polyamideimide resin and the polyester resin include polyamide resins and polyester resins described in JP-T-10-508048. The structural unit contained in the polyamideimide or polyester contained in these polyamideimide resin or polyester resin is represented, for example, by the following chemical formula (XI).

In the formula (XI), Y ^c represents —O— or —NH—.
In the formula (XI), each E ^c is independently a covalent bond, an alkylene group having 2 carbon atoms, a halogenated alkylene group having 2 carbon atoms, a CH ₂ group, a C (CX ^c ₃ ) ₂ group, It represents at least one group selected from the group consisting of a CO group, an O atom, an S atom, a SO ₂ group, a Si (R ^c ) ₂ group, and an N (R ^c ) group. Further, E ^c may be the same or different. In E ^c , R ^c is at least one of an alkyl group having 1 to 3 carbon atoms and a halogenated alkyl group having 1 to 3 carbon atoms, and is in a meta position or a para group with respect to the carbonyl group or the Y ^c group. Is in place. ^Xc is a halogen atom or a hydrogen atom.

In formula (XI), ^Ac represents a substituent. The ^Ac is, for example, a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a halogenated alkyl group having 1 to 3 carbon atoms, OR ^c (where R ^c is as defined above). An alkoxy group, an aryl group, a substituted aryl group by halogenation, etc., an alkoxycarbonyl group having 1 to 9 carbon atoms, an alkylcarbonyloxy group having 1 to 9 carbon atoms, or 1 to 12 carbon atoms. Aryloxycarbonyl group, arylcarbonyloxy group having 1 to 12 carbon atoms and substituted derivatives thereof, arylcarbamoyl group having 1 to 12 carbon atoms, and arylcarbonylamino group having 1 to 12 carbon atoms and substituted derivatives thereof Is mentioned. Further, if the A ^c there are multiple, A ^c may be respectively identical or different.

In formula (XI), A ^c ′ represents a substituent. Examples of the A ^c ′ include a halogen atom, an alkyl group having 1 to 3 carbon atoms, a halogenated alkyl group having 1 to 3 carbon atoms, a phenyl group, and a substituted phenyl group. Also, ^'if there are a plurality, A ^c' A c respectively may be the same or may be different. Examples of the substituent on the phenyl ring of the substituted phenyl group include a halogen atom, an alkyl group having 1 to 3 carbon atoms, a halogenated alkyl group having 1 to 3 carbon atoms, and combinations thereof.

In formula (XI), t and z represent the number of substitutions for A ^c and A ^c ′, respectively. Said t is an integer of 0-4. Said z is an integer of 0-3.
In Formula (XI), p is an integer of 0 to 3, q is an integer of 1 to 3, and r is an integer of 0 to 3.

  Further, the polyester may include a structural unit represented by the following formula (XII) or formula (XIII).

In the formula (XII) and the formula (XIII), X ^d and Y ^d represent a substituent. X ^d each independently represents a group selected from the group consisting of a hydrogen atom, a chlorine atom and a bromine atom. Y ^d represents a group represented by the following formula (XIV) or formula (XV). N represents an integer of 1 or more.

  As specific examples of polyester, “Byron” manufactured by Toyobo Co., Ltd. and “Polyester” manufactured by Nippon Synthetic Chemical Co., Ltd. can be suitably used.

  Examples of polyurethane urea resins include aliphatic cyclic structure-containing polyols, aliphatic cyclic structure-containing polyisocyanates, aliphatic cyclic structure-containing polyamines, and heavy compounds obtained by reacting acrylic compounds having active hydrogen atom-containing groups. Examples of the resin include coalescence. Specific examples thereof include a resin containing a material synthesized by a material described in JP 2011-132548 A and a production method. As a specific example of the polyurethane urea resin, “Tie Force” manufactured by DIC can be suitably used.

  Examples of the polycarbonate resin include the same examples as given in the description of the material forming the base material (A1). Specific examples thereof include Iupizeta PCZ series manufactured by Mitsubishi Gas Chemical Company, “FPC2136” manufactured by Mitsubishi Gas Chemical Company, and “Toughzet” manufactured by Idemitsu Kosan Co., Ltd.

  The resin that can be used as the non-liquid crystalline material having a positive intrinsic birefringence can contain an optional component in addition to the above-described polymer. However, the proportion of the above-mentioned polymer in the resin that can be used as a non-liquid crystalline material having a positive intrinsic birefringence is preferably 55% by weight or more, more preferably 80% by weight or more, and particularly preferably 90% by weight or more. In addition, it is usually 100% by weight or less.

  The glass transition temperature of the non-liquid crystalline material having a positive intrinsic birefringence forming the layer (A2) of the non-liquid crystalline material is preferably 70 ° C. or higher, more preferably 90 ° C. or higher, particularly preferably 110 ° C. or higher. Preferably it is 180 degrees C or less, More preferably, it is 160 degrees C or less, Most preferably, it is 140 degrees C or less. By forming the layer (A2) with a non-liquid crystalline material having a glass transition temperature in such a range, a desired retardation can be stably expressed in the non-liquid crystalline material layer (A2) by the stretching treatment. And a layer having excellent stability under high temperature and high temperature and high humidity.

  The layer (A2) of the non-liquid crystalline material is preferably a negative biaxial layer whose refractive indexes nx, ny and nz satisfy nx> ny and nx> nz. Accordingly, the contrast of the IPS liquid crystal panel is effectively improved by using a retardation film in which the layer (A2) of the non-liquid crystal material and the layer (B1) of the non-liquid crystal material are combined as an optical compensation film. Is possible.

The layer (A2) of the non-liquid crystalline material has an in-plane retardation Re _A2 (550) at a wavelength of 550 nm, preferably 50 nm or more, more preferably 70 nm or more, preferably 150 nm or less, more preferably 120 nm or less. It is. When the retardation Re _A2 (550) in the in-plane direction of the layer (A2) of the non-liquid crystalline material is within this range, the multilayer film (A) can be easily produced by stretching.

The layer (A2) of the non-liquid crystalline material has a retardation Rth _A2 (550) in the thickness direction at a wavelength of 550 nm, preferably 40 nm or more, more preferably 60 nm or more, preferably 150 nm or less, more preferably 120 nm or less. When the retardation Rth _A2 (550) in the thickness direction of the layer (A2) of the non-liquid crystalline material is within this range, the multilayer film (A) can be easily produced by stretching.

Here, a quotient obtained by dividing “retardation Re _A1 (550) of substrate (A1) at wavelength 550 nm” by “thickness of substrate (A1)” is “I”. Further, a quotient obtained by dividing “retardation Re _A2 (550) of the non-liquid crystalline material layer (A2) at a wavelength of 550 nm” by “the thickness of the non-liquid crystalline material layer (A2)” is “J”. In this case, I <J is preferable, 3I <J is more preferable, 5I <J is further preferable, and 10I <J is particularly preferable. By selecting a material that satisfies the relationship between the value I and the value J, the retardation of only the layer (A2) of the non-liquid crystalline material is accurately performed while performing a stretching process when the multilayer film (A) is produced. It becomes possible to measure.

  The thickness of the layer (A2) of the non-liquid crystalline material is preferably 0.1 μm or more, more preferably 1 μm or more, and preferably 40 μm or less, more preferably from the viewpoint of improving scratch resistance, handling properties and thin film properties. 30 μm or less. By setting the thickness of the layer (A2) of the non-liquid crystalline material in this range, the laminate can be thinned and the laminate can be excellent in high temperature durability.

  The variation in the thickness of the layer (A2) of the non-liquid crystal material is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less of the average thickness of the layer (A2). Specifically, it is 0%. Here, the thickness variation means a difference between the maximum value and the minimum value of the thickness. By realizing such an excellent thickness accuracy, it is possible to obtain a laminate and a retardation film that exhibit uniform optical characteristics in the MD direction and the TD direction. Moreover, such thickness precision is realizable by manufacturing a multilayer film (A) with the manufacturing method which combined the coating and extending | stretching mentioned later, for example.

  The peeling force between the substrate (A1) and the non-liquid crystalline material layer (A2) is preferably 0.05 N / 20 mm or less, more preferably 0.03 N / 20 mm or less, particularly preferably 0.01 N / 20 mm. It is as follows. The peeling force can be measured according to JIS K6855-2. By reducing the peeling force in this manner, the substrate (A1) can be peeled from the laminate, and the retardation film can be easily produced. The lower limit of the peeling force is preferably 0.001 N / 20 mm or more, more preferably 0.003 N / 20 mm or more, and particularly preferably 0.005 N / 20 mm or more. Such a small peeling force can be realized, for example, by appropriately selecting a combination of materials of the base material (A1) and the non-liquid crystalline material layer (A2) using materials that are not compatible with each other.

[1.1.3. Any layer]
The multilayer film (A) may include an arbitrary layer on the side of the base material (A1) opposite to the non-liquid crystalline material layer (A2).

[1.2. Multilayer film (B)]
As shown in FIG. 1, the multilayer film (B) 20 includes a layer (B1) 21 and a resin layer (B2) 22 of a non-liquid crystalline material. Since the resin layer (B2) 22 is in contact with the layer (B1) 21 of the non-liquid crystal material, another layer is provided between the layer (B1) 21 of the non-liquid crystal material and the resin layer (B2) 22. It is not done.

[1.2.1. Non-liquid crystalline material layer (B1)]
The layer (B1) of non-liquid crystalline material is a layer of non-liquid crystalline material having a negative intrinsic birefringence. As the non-liquid crystalline material having a negative intrinsic birefringence, a resin having a negative intrinsic birefringence is usually used. Further, as this resin, a transparent resin is usually used. As such a resin, a resin including a polymer obtained by polymerizing one or more monomers selected from the group consisting of styrenes, styrenes-maleic acid, maleimides, and (meth) acrylic acid esters is preferable. In this case, the polymer may be a homopolymer or a copolymer. Since such a polymer usually has a negative intrinsic birefringence, the intrinsic birefringence of the resin containing it can also be made negative.

  Here, styrenes mean styrene and styrene derivatives. Examples of the styrene derivative include those in which a substituent is substituted at the benzene ring or α-position of styrene. Specific examples of styrene derivatives include alkyl styrene such as methyl styrene and 2,4-dimethyl styrene; halogenated styrene such as chlorostyrene; halogen-substituted alkyl styrene such as chloromethyl styrene; alkoxy styrene such as methoxy styrene; Can be mentioned. Here, one kind of styrene may be used alone, or two or more kinds may be used in combination at any ratio.

  In addition, polymerization using styrenes-maleic acid as a monomer means copolymerizing styrenes and maleic acid. Furthermore, maleic acid may be polymerized in the form of maleic anhydride.

  Moreover, as maleimide, the compound represented by the following formula (XVI) is mentioned, for example.

In formula (XVI), R ^1e and R ^2e each independently represent a hydrogen atom or an alkyl group.
In formula (XVI), X ^e represents a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a phenyl group, a cyano group or a hydroxyl group.

  Examples of maleimides include maleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N-tertiarybutylmaleimide, N-cyclohexylmaleimide, N-phenyl Maleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-naphthylmaleimide, N-laurylmaleimide, N-hydroxylethylmaleimide, N-hydroxylphenylmaleimide, N-methoxyphenylmaleimide, N-carboxyphenylmaleimide, N-nitro Examples thereof include phenylmaleimide and N-tribromophenylmaleimide. Here, maleimides may be used alone or in combinations of two or more in any ratio. Among these, N-cyclohexylmaleimide, N-isopropylmaleimide, and N-phenylmaleimide are preferable.

  Examples of the (meth) acrylic acid ester include the same examples as mentioned in the description of the material forming the base material (A1). Here, (meth) acrylic acid ester may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Furthermore, the polymer obtained by polymerizing the above monomer is copolymerized with any monomer other than styrenes, styrenes-maleic acid, maleimides and (meth) acrylic acid esters, as long as the effects of the present invention are not significantly impaired. It may be made. However, in this polymer, the proportion of structural units having a structure formed by polymerizing a monomer selected from the group consisting of styrenes, styrenes-maleic acid, maleimides and (meth) acrylic acid esters is preferably It is 55% by weight or more, more preferably 70% by weight or more, particularly preferably 90% by weight or more, and usually 100% by weight or less.

Among the polymers described above, a polymer using styrene as a monomer and a copolymer of maleimides and styrene are preferable. That is, a resin containing a polymer obtained by polymerizing styrenes or styrenes-maleic acid and a resin containing a copolymer of maleimides and styrene are preferable as resins having a negative intrinsic birefringence. A polymer using styrene as a monomer is a polystyrene polymer, and by using a resin containing a polystyrene polymer, a desired retardation can be stably expressed in the layer (B1) of the non-liquid crystalline material. it can.
As the copolymer of maleimides and styrene, polymers described in JP-A Nos. 2001-31710 and 2000-204126 can be preferably used. “Polyimilex” and “Denka IP” manufactured by Denka are preferably used.

  In particular, the polystyrene polymer is preferably a polystyrene polymer having a syndiotactic structure. The polystyrene-based polymer having a syndiotactic structure has high heat resistance, can suppress heat shrinkability, and can stably develop desired retardation by stretching.

  Here, the polystyrene polymer has a syndiotactic structure means that the stereochemical structure of the polystyrene polymer has a syndiotactic structure. The syndiotactic structure is a three-dimensional structure in which phenyl groups as side chains are regularly and alternately arranged in opposite directions in the Fischer projection formula with respect to the main chain formed by carbon-carbon bonds. Say. A polystyrene polymer having a syndiotactic structure has a low specific gravity and excellent properties such as hydrolysis resistance, heat resistance and chemical resistance as compared with a conventional atactic polystyrene polymer.

The tacticity (stericity) of the polystyrene-based polymer can be quantified by an isotope carbon nuclear magnetic resonance method ( ¹³ C-NMR method). ^The tacticity measured by the ¹³ C-NMR method can be indicated by the existence ratio of a plurality of consecutive structural units. Generally, for example, when there are two consecutive structural units, it is a dyad, when it is three, it is a triad, and when it is five, it is a pentad. In this case, the polystyrene polymer having the syndiotactic structure refers to a polymer that satisfies the following (x) or (y).
(X) The racemic dyad usually has a syndiotacticity of 75% or more, preferably 85% or more and 100% or less.
(Y) The racemic pentad generally has a syndiotacticity of 30% or more, preferably 50% or more and 100% or less.

  For example, a polystyrene polymer having a syndiotactic structure can polymerize styrenes using a titanium compound and a condensation product of water and trialkylaluminum as a catalyst in an inert hydrocarbon solvent or in the absence of a solvent. (See Japanese Patent Application Laid-Open No. 62-187708). Poly (halogenated alkylstyrene) may be produced, for example, by the method described in JP-A-1-46912.

  The weight average molecular weight of a polymer obtained by polymerizing one or more monomers selected from the group consisting of styrenes, styrenes-maleic acid, maleimides and (meth) acrylic acid esters is preferably 130,000 or more, more preferably It is 140,000 or more, particularly preferably 150,000 or more, preferably 300,000 or less, more preferably 270,000 or less, and particularly preferably 250,000 or less. With such a weight average molecular weight, the glass transition temperature of the polymer can be increased, and the heat resistance of the laminate can be stably improved.

  The glass transition temperature of a polymer obtained by polymerizing one or more monomers selected from the group consisting of styrenes, styrenes-maleic acid, maleimides, and (meth) acrylic acid esters is preferably 85 ° C. or more, more preferably 90 ° C or higher, particularly preferably 95 ° C or higher. By increasing the glass transition temperature in this way, the glass transition temperature of the non-liquid crystalline material having a negative intrinsic birefringence forming the layer (B1) is effectively increased, and thus the heat resistance of the retardation film is stably improved. can do. Further, from the viewpoint of stably and easily producing the laminate, the glass transition temperature is preferably 160 ° C. or lower, more preferably 155 ° C. or lower, and particularly preferably 150 ° C. or lower.

  Further, the non-liquid crystalline material having a negative intrinsic birefringence and forming the layer (B1) of the non-liquid crystalline material is selected from the group consisting of the above styrene, styrene-maleic acid, maleimides and (meth) acrylic acid ester. It is preferably a mixture containing one or more polymers selected from the group consisting of a polycarbonate polymer, a polyester polymer and a polyarylene ether polymer in combination with a polymer obtained by polymerizing one or more monomers. By combining a polycarbonate polymer, a polyester polymer or a polyarylene ether polymer, the strength of the layer (B1) of the non-liquid crystalline material can be increased, the glass transition temperature can be controlled, and the optical properties can be controlled. It becomes possible.

  Examples of the polycarbonate polymer include the same examples as mentioned in the description of the material forming the base material (A1). Here, a polycarbonate polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Further, the polyester polymer is a polymer having structural units bonded by an ester bond. A polyester polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Examples of the polyester polymer are obtained by dehydration condensation or polymerization of a polyol having a plurality of hydroxyl groups such as glycol and diol, and a polyvalent carboxylic acid having a plurality of carboxyl groups such as dicarboxylic acid or its anhydride. Can be mentioned.

  Examples of the polyol include 1,2-propanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,4-pentanediol, 3-methyl-1,5- Pentanediol, 2,5-hexanediol, 2-methyl-1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2 -Methyl-1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,6-hexanediol and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  Examples of the polyvalent carboxylic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, and sebacic acid. And dicarboxylic acids such as trimellitic acid and pyromellitic acid, polyvalent carboxylic acids having a trivalent or higher valent carboxyl group, and anhydrides thereof. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  The polyester polymer may be a polymer obtained by copolymerizing any monomer other than polyol, polyvalent carboxylic acid or anhydride thereof. However, in the polyester polymer, the proportion of structural units having a structure formed by polymerizing polyol, polyvalent carboxylic acid or anhydride thereof is preferably 55% by weight or more, more preferably 70% by weight or more, particularly preferably. Is 90% by weight or more.

  As specific examples of the polyester polymer, “Byron” manufactured by Toyobo Co., Ltd. and “Polyester” manufactured by Nippon Synthetic Chemical Co., Ltd. can be suitably used.

  The polyarylene ether polymer is a polymer having a structural unit having an arylene ether skeleton in the main chain. A polyarylene ether polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Especially, as a polyarylene ether polymer, the polymer containing the structural unit represented by a following formula (XVII) is preferable.

In formula (XVII), each Q ¹ independently represents a halogen atom, a lower alkyl group (for example, an alkyl group having 7 or less carbon atoms), a phenyl group, a haloalkyl group, an aminoalkyl group, a hydrocarbon oxy group, or A halohydrocarbonoxy group (wherein the halogen atom and the oxygen atom are separated by at least two carbon atoms); Among these, Q ¹ is preferably an alkyl group or a phenyl group, and more preferably an alkyl group having 1 to 4 carbon atoms.

In formula (XVII), each Q ² independently represents a hydrogen atom, a halogen atom, a lower alkyl group (for example, an alkyl group having 7 or less carbon atoms), a phenyl group, a haloalkyl group, a hydrocarbon oxy group, or a halo. A hydrocarbon oxy group (wherein the halogen atom and the oxygen atom are separated by at least two carbon atoms). Among them, preferably a hydrogen atom ^{Q 2.}

The polyarylene ether polymer may be a homopolymer having one type of structural unit (homopolymer) or a copolymer having two or more types of structural units (copolymer).
When the polyarylene ether polymer containing the structural unit represented by the formula (XVII) is a homopolymer, preferred examples of the homopolymer include 2,6-dimethyl-1,4-phenylene ether units ( That is, a homopolymer having “-(C ₆ H ₂ (CH ₃ ) ₂ —O) —”) is exemplified.
Moreover, when the polyarylene ether polymer containing the structural unit represented by the formula (XVII) is a copolymer, a preferred example of the copolymer is 2,6-dimethyl-1,4-phenylene ether. A random copolymer having a unit and a 2,3,6-trimethyl-1,4-phenylene ether unit (that is, a structural unit represented by “— (C ₆ H (CH ₃ ) ₃ —O —) —”). A polymer is mentioned.

  The polyarylene ether polymer may contain a structural unit other than the arylene ether unit. In this case, the polyarylene ether polymer is a copolymer having an arylene ether unit and other structural units. However, the ratio of the arylene ether unit in the polyarylene ether polymer is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 80% by weight or more.

  As described above, a polymer obtained by polymerizing at least one monomer selected from the group consisting of styrenes, styrenes-maleic acid, maleimides, and (meth) acrylic acid esters, polycarbonate polymers, polyester polymers, and Among the combinations with one or more polymers selected from the group consisting of polyarylene ether polymers, it is particularly preferable to combine a polystyrene polymer and a polyarylene ether polymer.

  Furthermore, when combining a polystyrene polymer and a polyarylene ether polymer, because of the high expression of retardation and good compatibility with the polyarylene ether polymer, A homopolymer of styrenes is more preferable, and a polystyrene polymer having a syndiotactic structure is more preferable. Furthermore, even when the polystyrene polymer is a copolymer obtained by copolymerizing monomers other than styrenes, the proportion of monomers other than styrenes is less than 5% by weight from the viewpoint of compatibility with the polyarylene ether polymer. It is desirable.

  Polymers obtained by polymerizing one or more monomers selected from the group consisting of styrenes, styrenes-maleic acid, maleimides and (meth) acrylic acid esters, polycarbonate polymers, polyester polymers, and polyarylene ether polymers The weight ratio with one or more polymers selected from the group consisting of is preferably 90:10 to 55:45, more preferably 85:15 to 60:40, and particularly preferably 80:20. ~ 65: 35. When the weight ratio is in this range, desired retardation and desired optical properties can be easily expressed in the layer (B1) of the non-liquid crystal material by stretching.

  The non-liquid crystalline material having a negative intrinsic birefringence and forming the layer (B1) of the non-liquid crystalline material is selected from the group consisting of styrenes, styrenes-maleic acid, maleimides, and (meth) acrylic acid esters. In addition to a polymer obtained by polymerizing two or more types of monomers, and one or more types of polymers selected from the group consisting of a polycarbonate polymer, a polyester polymer, and a polyarylene ether polymer, an optional component may be included. Examples of the optional component include an antioxidant, an ultraviolet absorber, a light stabilizer, and a crosslinking agent. However, in the non-liquid crystalline material having a negative intrinsic birefringence forming the layer (B1), at least one kind selected from the group consisting of styrenes, styrenes-maleic acid, maleimides and (meth) acrylic acid esters The ratio of one or more polymers selected from the group consisting of a polymer obtained by polymerizing monomers and a polycarbonate polymer, a polyester polymer and a polyarylene ether polymer is preferably 50% by weight or more, more preferably 80%. % By weight or more, particularly preferably 90% by weight or more, and usually 100% by weight or less.

  The glass transition temperature of the non-liquid crystalline material having a negative intrinsic birefringence forming the layer (B1) of the non-liquid crystalline material is preferably 115 ° C. or higher, more preferably 120 ° C. or higher, and particularly preferably 125 ° C. or higher. The higher the glass transition temperature of the non-liquid crystalline material having a negative intrinsic birefringence, the better the heat resistance of the retardation film. However, if the glass transition temperature is excessively high, it may not be easy to produce a laminate. Therefore, the glass transition temperature of a non-liquid crystalline material having a negative intrinsic birefringence is usually 200 ° C. or lower.

  The tensile elongation at break of the non-liquid crystalline material layer (B1) is preferably 20% or less, more preferably 15% or less, and particularly preferably 10% or less. The tensile breaking elongation can be measured according to JIS K7162. In general, a non-liquid crystalline material having negative intrinsic birefringence has low mechanical strength. On the other hand, since the multilayer film (B) includes the resin layer (B2), even the non-liquid crystalline material layer (B1) having a low mechanical strength can be hardly damaged. Furthermore, the laminate of the present invention has a laminate structure including a base material (A1), a non-liquid crystal material layer (A2), an adhesive layer, a non-liquid crystal material layer (B1), and a resin layer (B2) in this order. Therefore, even this laminated structure can effectively prevent the non-liquid crystalline material layer (B1) from being damaged. Therefore, the low tensile rupture elongation of the layer (B1) as described above prevents damage to the layer (B1), and makes the effects of improving handling and impact resistance more prominent. There is technical significance.

  The layer (B1) of the non-liquid crystalline material is preferably a positive biaxial layer in which the relationship between the refractive indexes nx, ny and nz satisfies nz> nx> ny. Accordingly, the contrast of the IPS liquid crystal panel is effectively improved by using a retardation film in which the layer (A2) of the non-liquid crystal material and the layer (B1) of the non-liquid crystal material are combined as an optical compensation film. Is possible.

The layer (B1) of the non-liquid crystalline material has an in-plane retardation Re _B1 (550) at a wavelength of 550 nm, preferably 40 nm or more, more preferably 50 nm or more, preferably 150 nm or less, more preferably 100 nm or less. It is. When the retardation Re _B1 (550) in the in-plane direction of the layer (B1) of the non-liquid crystalline material is within this range, the multilayer film (B) can be easily manufactured by stretching.

The layer of non-liquid material (B1) is retardation in the in-plane direction at a wavelength of 450nm _Re B1 (450) and the in-plane direction at a wavelength of 550nm retardation _Re B1 is _{(550), Re B1 (450} ) / It is preferable to satisfy Re _B1 (550)> 1.00. When Re _B1 (450) and Re _B1 (550) satisfy this relationship, a retardation film capable of exhibiting a compensation effect for the IPS liquid crystal cell in a wide wavelength range can be obtained.

The layer (B1) of the non-liquid crystalline material has a retardation Rth _B1 (550) in the thickness direction at a wavelength of 550 nm, preferably −150 nm or more, more preferably −130 nm or more, preferably −50 nm or less. Preferably, it is −60 nm or less. When the retardation Rth _B1 (550) in the thickness direction of the layer (B1) of the non-liquid crystalline material is within this range, the multilayer film (B) can be easily produced by stretching.

  The in-plane slow axis of the layer (B1) of the non-liquid crystalline material is usually parallel to the in-plane slow axis of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence of the multilayer film (A). To do. Thereby, optical compensation can be effectively performed in the IPS liquid crystal panel, and the contrast of the liquid crystal display device can be improved.

  The thickness of the non-liquid crystalline material layer (B1) is preferably 5 μm or more, more preferably 7 μm or more, preferably 30 μm or less, more preferably 15 μm or less. By making the thickness of the layer (B1) of the non-liquid crystalline material in this range, the laminate can be thinned and the laminate can be excellent in high temperature durability.

  The variation in the thickness of the layer (B1) of the non-liquid crystalline material is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less of the average thickness of the layer (B1). 0%. By realizing such thickness accuracy, it is possible to obtain a laminate and a retardation film that exhibit uniform optical characteristics in the MD direction and the TD direction. Such thickness accuracy can be realized, for example, by manufacturing the multilayer film (B) by a manufacturing method in which melt extrusion and stretching described later are combined.

[1.2.2. Resin layer (B2)]
The resin layer (B2) is a layer formed of a resin. As this resin, a thermoplastic resin is usually used. Further, as this resin, a transparent resin is usually used. Examples of such resins include polymer resins having an alicyclic structure, (meth) acrylic resins, polycarbonate resins, (meth) acrylic acid ester-vinyl aromatic compound copolymer resins, and polyethersulfone resins. A resin selected from is preferred. These resins are excellent in mechanical strength, can have a desired peel strength with respect to the non-liquid crystalline material layer (B1), and can reduce the retardation developed by stretching.

  As a polymer resin having an alicyclic structure capable of forming the resin layer (B2), a (meth) acrylic resin, a polycarbonate resin, a (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and a polyethersulfone resin For example, the same resins as those described as the material for forming the base material (A1) can be used. Therefore, a polymer resin having an alicyclic structure capable of forming the resin layer (B2), a (meth) acrylic resin, a polycarbonate resin, a (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and a polyethersulfone In each of the resins, the types and amounts of the polymer and optional components that can be contained in the resin can be the same as those of the resins described as materials for forming the base material (A1).

  Among these resins, as the resin forming the resin layer (B2), a polymer resin and a (meth) acrylic resin having an alicyclic structure are preferable, and a (meth) acrylic resin is particularly preferable.

  The glass transition temperature of the resin forming the resin layer (B2) is preferably set according to the glass transition temperature of the non-liquid crystalline material having a negative intrinsic birefringence forming the layer (B1). Specifically, the glass transition temperature Tg (B1) of the non-liquid crystalline material having a negative intrinsic birefringence forming the layer (B1), and the glass transition temperature Tg (B2) of the resin forming the resin layer (B2) However, it is preferable to satisfy | fill Tg (B1)> Tg (B2) +20 degreeC, and it is more preferable to satisfy | fill Tg (B1)> Tg (B2) +25 degreeC. Thus, when the stretching treatment is performed at a stretching temperature higher than the glass transition temperature Tg (B1) of the non-liquid crystalline material having a negative intrinsic birefringence, the polymer is hardly oriented in the resin layer (B2), Become. Therefore, since a large retardation does not appear in the resin layer (B2) even by the stretching treatment, it is possible to accurately measure the retardation of only the non-liquid crystalline material layer (B1) while performing the stretching treatment.

  Furthermore, the glass transition temperature of the polymer resin having an alicyclic structure capable of forming the resin layer (B2) is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, preferably 150 ° C. or lower, more preferably Is 120 ° C. or lower, more preferably 110 ° C. or lower. By setting the glass transition temperature to be equal to or higher than the lower limit value of the above range, durability at high temperatures can be improved, and by setting the glass transition temperature to be equal to or lower than the upper limit value, stretching can be facilitated.

  In particular, the glass transition temperature of the (meth) acrylic resin capable of forming the resin layer (B2) is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, preferably 120 ° C. or lower, more preferably 110 ° C. or lower. It is. By setting the glass transition temperature to be equal to or higher than the lower limit of the above range, blocking when the resin pellets are dried at a high temperature can be suppressed, so that mixing of moisture can be prevented. Moreover, since the orientation of the (meth) acrylic polymer at the time of stretching can be reduced by setting it to the upper limit value or less, the resin layer (B2) inhibits the optical function of the layer (B1) of the non-liquid crystalline material. Can be suppressed.

  In particular, the glass transition temperature of the polycarbonate resin capable of forming the resin layer (B2) is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, still more preferably 100 ° C. or higher, particularly preferably 120 ° C. or higher. Is 160 ° C. or lower, more preferably 150 ° C. or lower. By setting the glass transition temperature to be equal to or higher than the lower limit value of the above range, durability at high temperatures can be improved, and by setting the glass transition temperature to be equal to or lower than the upper limit value, stretching can be facilitated.

The resin layer (B2) has an in-plane retardation Re _B2 (550) at a wavelength of 550 nm, preferably 30 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and usually 0 nm or more. By reducing the in-plane retardation Re _B2 (550) of the resin layer (B2), only the layer (B1) of the non-liquid crystalline material while stretching is performed when the multilayer film (B) is produced. It becomes possible to measure retardation.

  The thickness of the resin layer (B2) is preferably 1 μm or more, more preferably 3 μm or more, particularly preferably 5 μm or more, preferably 50 μm or less, more preferably 30 μm or less, and particularly preferably 15 μm or less. By setting the thickness of the resin layer (B2) to be equal to or higher than the lower limit of the above range, the mechanical strength of the resin layer (B2) can be sufficiently increased. Moreover, the softness | flexibility and handling property of a resin layer (B2) can be made favorable by setting it as below an upper limit.

  The peeling force between the layer (B1) of non-liquid crystalline material having a negative intrinsic birefringence and the resin layer (B2) is preferably 0.5 N / 20 mm or less, more preferably 0.3 N / 20 mm or less, particularly preferably. Is 0.15 N / 20 mm or less. The peeling force can be measured according to JIS K6855-2. By reducing the peeling force in this way, the resin layer (B2) can be peeled from the laminate, and the retardation film can be easily produced. The lower limit of the peeling force is preferably 0.01 N / 20 mm or more, more preferably 0.03 N / 20 mm or more, and particularly preferably 0.05 N / 20 mm or more. Such a small peeling force can be realized, for example, by appropriately selecting a combination of materials of the non-liquid crystal material layer (B1) and the resin layer (B2) with materials that are not compatible with each other.

[1.2.3. Any layer]
The multilayer film (B) may include an arbitrary layer on the side of the resin layer (B2) opposite to the non-liquid crystalline material layer (B1).

[1.3. Adhesive layer]
As shown in FIG. 1, a non-liquid crystalline material layer (A2) 12 having a positive intrinsic birefringence and a surface 12U opposite to the substrate (A1) 11 and a non-liquid crystalline material having a negative intrinsic birefringence. A single adhesive layer 30 is provided between the layer (B1) 21 and the surface 21D opposite to the resin layer (B2) 22. Here, the fact that the adhesive layer 30 is interposed between the surface 12U and the surface 21D alone means that there is only the adhesive layer 30 between the surface 12U and the surface 21D, and there is no layer other than the adhesive layer 30. To do.

  The adhesive layer is a layer formed by a cured product of an adhesive. Here, the adhesive includes a narrowly defined adhesive having a shear storage elastic modulus of 1 MPa to 500 MPa at 23 ° C. after curing, and a pressure-sensitive adhesive having a shear storage elastic modulus at 23 ° C. of less than 1 MPa. However, when the multi-layer film (A) and the multi-layer film (B) are bonded to each other, if the bonding is performed using the pressure-sensitive adhesive, it is possible to suppress the entrapment of bubbles and the inclusion of foreign substances. In addition, the thickness of the pressure-sensitive adhesive layer tends to increase in order to ensure strong adhesive strength. On the other hand, in the bonding using a narrowly defined adhesive, the thickness of the adhesive layer can be reduced. Therefore, it is preferable to use a narrowly defined adhesive having a shear storage modulus of 1 MPa to 500 MPa at 23 ° C. after curing as the adhesive.

  As the adhesive, an active energy ray curable adhesive is usually used. The active energy ray-curable adhesive refers to an adhesive that can be cured when irradiated with active energy rays such as ultraviolet rays, X-rays, and electron beams. Among them, an adhesive that can be cured by ultraviolet rays is preferable because an inexpensive device can be used. Here, the irradiated active energy rays may include arbitrary energy rays such as visible light, ultraviolet rays, infrared rays, and electron beams.

  As an example of a suitable adhesive, one containing (meth) acrylate in an uncured state can be used. Among them, as the (meth) acrylate, (I) an oligomer-type polyfunctional (meth) acrylate and (II) a mono (meta) having at least one hydroxyl group having a viscosity of 10 mPa · s or more and less than 500 mPa · s at a temperature of 20 ± 1.0 ° C. ) A combination of acrylates is preferred.

  (I) The number of functional groups per molecule of the oligomer-type polyfunctional (meth) acrylate is preferably 3 or less, more preferably 2 or 3. Here, the number of functional groups refers to the number of functional groups that can exhibit radical polymerizability. When the number of functional groups is 3 or less, the curing shrinkage of the cured product when the adhesive is cured can be reduced, and the glass transition temperature of the cured product can be lowered. A layer film (B) can be favorably bonded.

  Examples of (I) oligomer-type polyfunctional (meth) acrylates include radicals such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, and silicone (meth) acrylate. An acrylic oligomer having 3 or less functional groups capable of exhibiting polymerizability is exemplified. Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

Polyester (meth) acrylate is obtained, for example, as a reaction product obtained by reacting a terminal hydroxyl group of a polyester obtained from a polybasic acid and a polyhydric alcohol with acrylic acid or methacrylic acid.
Examples of the polybasic acid include phthalic acid, adipic acid, maleic acid, itaconic acid, succinic acid, terephthalic acid and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.
Examples of the polyhydric alcohol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol. One of these may be used alone, or two or more of these may be used in combination at any ratio.
Examples of polyester (meth) acrylate are EBECRYL 851,852,853,884,885 (manufactured by Daicel Cytec); Olester (manufactured by Mitsui Chemicals); Aronix M-6100,6200,6250,6500 ( Toagosei Co., Ltd.).

Epoxy (meth) acrylate is obtained, for example, as a reaction product obtained by ring-opening addition reaction of acrylic acid or methacrylic acid to an epoxy polymer.
Examples of the epoxy polymer 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 polymer 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, and the like. Further, for example, unsaturated fatty acid epoxy polymers such as butadiene-based epoxy polymers and isoprene-based epoxy polymers can also be used. Examples of the alicyclic epoxy polymer include vinylcyclohexene monooxide, 1,2-epoxy-4-vinylcyclohexane, 1,2: 8,9-diepoxysilimonene, and 3,4-epoxycyclohexenylmethyl-3 ′. 4,4′-epoxycyclohexenecarboxylate and the like can be used. One of these may be used alone, or two or more of these may be used in combination at any ratio.
Examples of epoxy (meth) acrylates include EBECRYL 600, 860, 3105, 3420, 3700, 3701, 3702, 3703, 3708, 6040 (manufactured by Daicel Cytec); Neopole 8101, 8250, 8260, 8270, 8355, 8351, 8335, 8414, 8190, 8195, 8316, 8317, 8318, 8319, 8371 (manufactured by Iupika Japan); Denacol acrylate DA212, 250, 314, 721, 722, DM201 (manufactured by Nagase ChemteX); Van Beam ( Harima Chemicals, Inc.); Miramer PE210, PE230, EA2280 (manufactured by Toyo Chemicals), and the like.

Urethane (meth) acrylate is obtained as a reactant having a urethane skeleton at the center, for example, by reacting a (meth) acrylic monomer having a hydroxyl group, a polyfunctional isocyanate and a polyhydric alcohol.
Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, trimethylolpropane tolylene diisocyanate, and diphenylmethane triisocyanate. Among them, hexamethylene diisocyanate having good weather resistance is preferably used. One of these may be used alone, or two or more of these may be used in combination at any ratio.
As a polyhydric alcohol, what can be used for polyester (meth) acrylate, for example can be used.
Examples of urethane (meth) acrylate are EBECRYL 204, 210, 220, 230, 270, 4858, 8200, 8201, 8402, 8804, 8807, 9260, 9270, KRM 8098, 7735, 8296 (manufactured by Daicel Cytec) UX2201, 2301, 3204, 3301, 4101, 6101, 7101, 8101, 0937 (manufactured by Nippon Kayaku); UV6640B, 6100B, 3700B, 3500BA, 3520TL, 3200B, 3000B, 3310B, 3210EA, 7000B, 6630B, 7461TE ( Nippon Synthetic Chemical Co., Ltd.); Iupica 8921, 8932, 8940, 8936, 8937, 8980, 8975, 8976 (manufactured by Nippon Iupika); Miramer PU240, PU 340 (manufactured by Toyo Chemicals Co., Ltd.).

Polyether (meth) acrylate is obtained, for example, as a reaction product of polyether polyol and acrylic acid or methacrylic acid.
Examples of the polyether (meth) acrylate include ethoxylated trimethylolpropane triacrylate and propoxylated trimethylolpropane triacrylate. Moreover, when an example is given as a product, EBECRYL81 (manufactured by Daicel Cytec Co., Ltd.) may be mentioned.

Silicone (meth) acrylate is obtained, for example, as a reaction product obtained by further reacting an addition reaction product of an organopolysiloxane and an alkenyl group-containing epoxy polymer with acrylic acid or methacrylic acid.
Examples of the organopolysiloxane include, for example, a trimethylsiloxy group-capped methylhydrogen polysiloxane having both molecular chains, a trimethylsiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer having both molecular chains, and a trimethylsiloxy group-capped dimethyl with both molecular chains. Siloxane / Methylhydrogensiloxane / Methylphenylsiloxane copolymer, dimethylhydrogensiloxy group-blocked dimethylpolysiloxane with both molecular chains, dimethylhydrogensiloxy group-blocked dimethylpolysiloxane / methylhydrogensiloxane copolymer with both ends of molecular chain, Molecular chain both ends dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylphenylsiloxane copolymer, molecular chain both ends dimethylhydrogensiloxy group-blocked In addition to ruthenyl polysiloxane, dimethylpolysiloxane whose molecular chain end is blocked with a dimethylhydrogensiloxy group and other molecular chain end is blocked with a trimethylsiloxy group, it is basically not only of linear structure but also partially Also included are those containing a branched siloxane structure. These may be used alone or in combination of two or more at any ratio.
As the alkenyl group-containing epoxy polymer, for example, one having an epoxy group such as a glycidyloxy group and having an alkenyl group can be used. Here, the number of epoxy groups contained in the alkenyl group-containing epoxy polymer is usually 2 or more, preferably 2 to 7, more preferably 2 to 3 per molecule. The number of alkenyl groups contained in the alkenyl group-containing epoxy polymer is usually 1 or more, preferably 1 to 5, more preferably 1 to 2, particularly preferably 1 per molecule. Furthermore, the number of carbon atoms of the alkenyl group is preferably 2 to 6, more preferably 2 to 4. Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, and a hexenyl group. Among these, an allyl group is particularly preferable.
Silicone (meth) acrylate can be obtained by reacting the epoxy group in the addition reaction product of the organopolysiloxane and the alkenyl group-containing epoxy polymer with (meth) acrylic acid.
Examples of silicone (meth) acrylates include compounds exemplified in JP-A No. 2004-189942; “TEGO” manufactured by Evonik Degussa Japan; SQ series manufactured by Tokushiki;

Of these oligomer-type polyfunctional (meth) acrylates, polyester (meth) acrylate, epoxy (meth) acrylate, and urethane (meth) acrylate are preferable.
Moreover, oligomer type polyfunctional (meth) acrylate may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The molecular weight of the oligomer-type polyfunctional (meth) acrylate is a weight average molecular weight (Mw) in terms of polyisoprene measured by gel permeation chromatography, and is usually 500 or more and 10,000 or less.

  (I) It is preferable that the quantity of oligomer type polyfunctional (meth) acrylate is 15 to 65 parts by weight with respect to 100 parts by weight of (meth) acrylate contained in the uncured adhesive. By being within this range, a stronger adhesive force can be obtained.

(II) Examples of mono (meth) acrylate having at least one hydroxyl group having a viscosity of 10 mPa · s or more and less than 500 mPa · s at a temperature of 20 ± 1.0 ° C. include the following. Moreover, in the following illustration, the viscosity in parenthesis represents the viscosity in 20 +/- 1.0 degreeC of the example thing.
Examples of mono (meth) acrylate having at least one hydroxyl group having a viscosity of 10 mPa · s or more and less than 500 mPa · s at a temperature of 20 ± 1.0 ° C. include 2-hydroxypropyl acrylate (10.9 mPa · s), 4-hydroxy Butyl acrylate (17 mPa · s), 2-hydroxy-3-phenoxypropyl acrylate (373 mPa · s), glycerin monomethacrylate (eg “Blenmer GLM” 150 mPa · s manufactured by NOF Corporation), polyethylene glycol monomethacrylate (eg NOF Corporation) “Blemmer PE-90” 15 mPa · s; NOF “Blemmer PE-200” 30 mPa · s; NOF “Blemmer PE-350” 45 mPa · s), polypropylene glycol monomethacrylate (for example, NOF Corporation) " NOMER PP-1000 "50 mPa.s; NOF" Blenmer "PP-500" 75 mPa.s ", poly (ethylene propylene glycol) monomethacrylate (for example, NOF" Blenmer 50 PEP-300 "55 mPa.s) Polyethylene glycol / polypropylene glycol monomethacrylate (for example, “Blenmer 70PEP-350B” 79 mPa · s manufactured by NOF Corporation), propylene glycol / polybutylene glycol monomethacrylate (for example, “Blenmer 10PPB-500B” 48 mPa · s manufactured by NOF Corporation), Polyethylene glycol monoacrylate (for example, “Blemmer AE-200” 15 mPa · s made by NOF Corporation), polypropylene glycol monoacrylate (for example “Blemmer AP-400” 48 mP made by NOF Corporation) a), aliphatic epoxy acrylate (for example, “EBECRYL112” 55 mPa · s manufactured by Daicel Cytec Co., Ltd .; “PA500” 71.8 mPa · s manufactured by Toho Chemical Co., Ltd.) and the like.

  (II) By using a mono (meth) acrylate having at least one hydroxyl group having a viscosity of 10 mPa · s or more and less than 500 mPa · s at a temperature of 20 ± 1.0 ° C., the adhesive coating suitability is improved and adhesion is achieved. This is preferred because the layer exhibits stronger adhesion. The viscosity range at the temperature of 20 ± 1.0 ° C. is more preferably 50 mPa · s or more, particularly preferably 70 mPa · s or more, more preferably 400 mPa · s or less, and particularly preferably 350 mPa · s or less. .

  (II) The amount of mono (meth) acrylate having at least one hydroxyl group having a viscosity of 10 mPa · s or more and less than 500 mPa · s at a temperature of 20 ± 1.0 ° C. is (meth) acrylate 100 contained in the uncured adhesive. It is preferably 35 to 85 parts by weight with respect to parts by weight. By being within this range, a stronger adhesive force can be obtained.

  Further, in the cured state or the uncured state, the adhesive may contain an optional component other than (meth) acrylate as long as the effects of the present invention are not significantly impaired. Optional components include, for example, a polymerization initiator, a crosslinking agent, an inorganic filler, a polymerization inhibitor, a color pigment, a dye, an antifoaming agent, a leveling agent, a dispersing agent, a light diffusing agent, a plasticizer, an antistatic agent, and a surface activity. Agents, non-reactive polymers (inert polymers), viscosity modifiers, near-infrared absorbers, and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.

The type of the polymerization initiator can be selected according to the mode of curing of the adhesive. For example, when the adhesive can be cured by irradiation with active energy rays, a photopolymerization initiator can be used. In this case, a photosensitizer may be used in combination with the photopolymerization initiator.
Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 1- (4-isopropylphenyl) -2-hydroxy-2-methyl. Propan-1-one, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, methylbenzoyl formate, 2,2-diethoxyacetophenone, β-ionone, β-bromostyrene, diazoaminobenzene , Α-amylcinnackaldehyde, 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-trimethylbenzoyl diphenyl -Phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl- 2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, anthracenebenzophenone, α-chloroanthraquinone, diphenyl disulfide, hexachlorobutadiene, pentachlorobutadiene, octachlorobutene, 1 -Chlormethylnaphthalene, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (o-benzoyl)] oxime, 1- [9-ethyl-6- (2-methylbenzoyl) -9H- Carbazol-3-yl] ethanone 1- (o-acetyloxime), (4-methylphenyl) [4- (2-methylpropyl) phenyl] iodonium hexafluorophosphate, 3-methyl-2-butynyltetramethylsulfonium Examples thereof include hexafluoroantimonate and diphenyl- (p-phenylthiophenyl) sulfonium hexafluoroantimonate. One of these may be used alone, or two or more of these may be used in combination at any ratio.
The amount of the polymerization initiator is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, preferably 10 parts by weight with respect to 100 parts by weight of (meth) acrylate contained in the uncured adhesive. Part or less, more preferably 5 parts by weight or less.
Examples of the photosensitizer include n-butylamine, triethylamine, and poly-n-butylphosphine.

Examples of the antifoaming agent include BYK051,052,055,057,1790,065,070,088,354,392 manufactured by Big Chemie Japan; LR-20R, OP-80R, OP-83RAT, OP manufactured by Nippon Oil & Fats Co., Ltd. -85R, PP-40R, SO-80R, SP-60R, BP-70R, CP-08R, DS-60HN, and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.
The antifoaming agent can be used in an amount within a range in which the adhesive force of the adhesive layer does not decrease. Specifically, the antifoaming agent is preferably 0.1 parts by weight with respect to 100 parts by weight of the solid content of the uncured adhesive. It is above, Preferably it is 1.0 weight part or less, More preferably, it is 0.5 weight part or less.

As the crosslinking agent, for example, a bifunctional or higher functional (meth) acrylate monomer having a molecular weight of less than 500 can be used. Specific examples of the crosslinking agent include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloxypropyl methacrylate, tetraethylene diacrylate, Polyethylene glycol # 400 diacrylate, tricyclodecane dimethanol di (meth) acrylate, dipentaerythritol hexaacrylate, 1,6-hexanediol di (meth) acrylate, hydroxypentane phosphate neopentyl glycol diacrylate, 1,9 -Nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol triacryl , Pentaerythritol tetraacrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetraacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol Mention may be made of dimethacrylate, ethoxylated bisphenol A dimethacrylate. One of these may be used alone, or two or more of these may be used in combination at any ratio.
The amount of the crosslinking agent is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, preferably 10 parts by weight with respect to 100 parts by weight of (meth) acrylate contained in the uncured adhesive. Below, more preferably 5 parts by weight or less. By setting the amount of the crosslinking agent to be equal to or more than the lower limit of the above range, the mechanical strength of the adhesive layer can be effectively increased. Moreover, the adhesive force of a multilayer film (A) and a multilayer film (B) can be made high by setting it as below an upper limit.

As the viscosity modifier, for example, a slurry in which metal oxide particles having a particle diameter of several nm to several hundred nm are dispersed in a solvent can be used. Examples of the metal oxide include silica, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, and a mixture thereof. Specific examples of the viscosity modifier include organosilica sol, methanol silica sol, IPA-ST, IPA-ST-UP, IPA-ST-ZL, EG-ST, NPC-ST-30, DMAC-ST, MEK- ST, MIBK-ST, XBA-ST, PMA-ST, PGM-ST; PL-1-IPA, PL-1-TOL, PL-2L-PGME, PL-2L-MEK manufactured by Fuso Chemical Co., Ltd. it can. One of these may be used alone, or two or more of these may be used in combination at any ratio.
The amount of the viscosity modifier is an amount of the metal oxide with respect to 100 parts by weight of (meth) acrylate contained in the uncured adhesive, preferably 1 part by weight or more, more preferably 5 parts by weight or more, preferably 15 parts by weight or less, more preferably 10 parts by weight or less. By setting the amount of the viscosity adjusting agent to be equal to or more than the lower limit of the above range, the viscosity of the adhesive in an uncured state can be adjusted appropriately. Moreover, the adhesive force of a multilayer film (A) and a multilayer film (B) can be made high by setting it as below an upper limit.

  Specific examples of the adhesive include those described in JP-A-7-82544.

  The thickness of the adhesive layer is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 3 μm or more, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less. By setting the thickness of the adhesive layer to be equal to or more than the lower limit of the above range, the adhesive force between the multilayer film (A) and the multilayer film (B) can be increased. Moreover, by making it into the upper limit value or less, it becomes possible to increase the curing rate of the adhesive and to easily cure the adhesive, and to reduce the thickness.

[1.4. Other matters related to laminates]
In the above-described laminate, the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence and the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence have desired optical properties (particularly, retardation). Have. Therefore, the phase difference which combined the layer (A2) of non-liquid crystalline material with a positive intrinsic birefringence and the layer (B1) of non-liquid crystalline material with a negative intrinsic birefringence by peeling an unnecessary layer from this laminated body. A film can be obtained easily.

  In the above-described laminate, the thickness of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence and the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence can be reduced. In particular, the non-liquid crystalline material layer (B1) is generally easily damaged because the mechanical strength of the non-liquid crystalline material having a negative intrinsic birefringence is weak. However, in the above-described laminate, the non-liquid crystalline material layer ( The damage of B1) can be stably prevented. Further, even if the thickness of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence and the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence is usually reduced, the variation in thickness is reduced. Is possible. Therefore, a thin retardation film can be easily obtained by peeling off unnecessary layers from the laminate.

[1.5. Manufacturing method of laminate]
The laminate 100 shown in FIG. 1 includes, for example, a step of manufacturing a multilayer film (A) 10, a step of manufacturing a multilayer film (B) 20, and a multilayer film (A) 10 and a multilayer film (B ) 20 can be manufactured by a manufacturing method including a step of bonding through the adhesive layer 30. Hereinafter, this manufacturing method will be described.

[1.5.1. Example of production process of multilayer film (A)]
FIG. 2 is a schematic view schematically showing an example of a production apparatus 200 for producing the multilayer film (A) 10. As shown in FIG. 2, when manufacturing the multilayer film (A) 10, the manufacturing apparatus 200 provided with the expansion | deployment part 210, the drying part 220, and the extending | stretching part 230 can be used.

The developing unit 210 is a device that can develop (cast) a solution 240 obtained by dissolving a non-liquid crystalline material having a positive intrinsic birefringence in a solvent onto the base material (A1) 11.
As a solvent for dissolving the non-liquid crystalline material having a positive intrinsic birefringence, a solvent capable of dissolving the non-liquid crystalline material having a positive intrinsic birefringence and not extremely eroding the substrate (A1) can be used. As this solvent, an appropriate solvent can be selected according to the non-liquid crystalline material having a positive intrinsic birefringence and the base material (A1). Specific examples of the solvent include: halogenated hydrocarbons such as chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, o-dichlorobenzene; phenols such as phenol and parachlorophenol; benzene, Aromatic hydrocarbons such as toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene; acetone, ethyl acetate, t-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, propylene glycol , Dipropylene glycol, 2-methyl-2,4-pentanediol, ethyl cellosolve, butyl cellosolve, 2-pyrrolidone, N- Chill-2-pyrrolidone, pyridine, triethylamine, dimethylformamide, dimethylacetamide, acetonitrile, butyronitrile, methyl isobutyl ketone, methyl ether ketone, cyclopentanone, carbon disulfide, and the like. Further, depending on the type of non-liquid crystalline material having a positive intrinsic birefringence, sulfuric acid may be used as a solvent. A solvent may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  In the solution 240, the concentration of the non-liquid crystalline material having a positive intrinsic birefringence takes into consideration the coating property (for example, the degree of foreign matter contamination, unevenness or streaks during coating) on the base material (A1) 11. , Preferably 0.5% by weight or more, more preferably 1% by weight or more, particularly preferably 2% by weight or more, preferably 50% by weight or less, more preferably 40% by weight or less, particularly preferably 30% by weight or less. It is. By setting the concentration to be equal to or higher than the lower limit of the above range, the viscosity of the solution 240 can be increased and the solution 240 can be developed with a desired thickness. Moreover, by making it into the upper limit value or less, the viscosity of the solution 240 can be lowered, and deterioration of the surface state of the layer of the solution 240 can be prevented.

  The solution 240 may contain a compounding agent such as a surfactant in addition to the non-liquid crystalline material having positive intrinsic birefringence and the solvent.

  As a developing method in the developing unit 210, a coating method is usually used. Specific examples of the coating method include spin coating, roll coating, die coating, and blade coating.

  The drying unit 220 is a device that can dry the solution 240 developed on the base material (A1) 11. By drying the solution 240, the pre-stretching film 250 including the base material (A1) 11 and the layer (A2) of the non-liquid crystalline material having positive intrinsic birefringence in this order is obtained. The drying unit is preferably a device capable of adjusting the temperature in the range of 30 ° C. to 200 ° C., and preferably has a mechanism for positively sending temperature-controlled hot air on the film surface.

  The stretching unit 230 is a device that can stretch the base material (A1) 11 after drying the solution 240. When the base material (A1) 11 is stretched, the layer (A2) of the positive non-liquid crystalline material formed thereon is also stretched. Since this stretching causes retardation, a layer (A2) of a non-liquid crystalline material having a desired retardation can be obtained. As such a stretching unit 230, for example, a tenter stretching machine can be used. The tenter stretching machine generally includes a pair of rails and a gripper that can move along the rails. The rail has a rail widening portion in which the rail width is increased in a taper shape in the TD direction toward the downstream side in the MD direction of the belt-like film. In such a tenter stretching machine, the belt-shaped film can be stretched in the TD direction by gripping both ends of the film in the TD direction with a gripper and running the gripper along the rail.

  When manufacturing a multilayer film (A) using such a manufacturing apparatus 200, manufacture by a roll toe roll method is possible using the elongate film-form base material (A1) 11. For example, the base material (A1) 11 is pulled out from the roll of the base material (A1) 11, and the pulled out base material (A1) 11 is continuously sent to the developing unit 210.

  The thickness of the base material (A1) 11 before stretching is preferably 40 μm or more, more preferably 60 μm or more from the viewpoint of improving handling properties and mechanical strength, and preferably 500 μm or less from the viewpoint of improving handling properties. More preferably, it is 150 μm or less.

  The developing unit 210 performs a process of developing (casting) the solution 240 on the base material (A1) 11. At this time, the amount of the solution 240 to be developed is such that the thickness of the solution 240 formed by the development is such that the non-liquid crystalline material layer (A2) 12 having a desired thickness can be obtained in the multilayer film (A) 10. It can be set as follows.

  In the surface 11U of the base material (A1) 11, the region where the solution 240 is developed is preferably not the entire base material (A1) 11, but the region excluding the gripped portion during stretching. For example, when the base material (A1) 11 is strip-shaped and the strip-shaped base material (A1) 11 is stretched in the TD direction, both end portions in the width direction of the base material (A1) 11 that are gripped portions at the time of stretching It is preferable to spread the solution 240 on the central portion of the substrate (A1) 11 except for the above.

The base material (A1) 11 on which the solution 240 is developed on the surface 11U is sent to the drying unit 220. In the drying unit 220, a process of drying the solution 240 developed on the surface of the base material (A1) 11 is performed.
The drying temperature may be set according to the type of solvent of the solution 240, preferably 40 ° C. or higher, more preferably 50 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower. Drying may be performed at a constant temperature, or may be performed by increasing the temperature stepwise or continuously.
The drying time is preferably 10 seconds or more, more preferably 30 seconds or more, preferably 60 minutes or less, more preferably 30 minutes or less. By setting the drying time to be equal to or greater than the lower limit of the above range, the solvent can be sufficiently removed from the layer of the solution 240, and the reliability of the product can be improved. Moreover, productivity can be improved by making it into an upper limit or less.

  By drying, a layer (A2) of a non-liquid crystalline material having a positive intrinsic birefringence is formed on the surface of the substrate (A1) 11. The thickness of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence before stretching thus obtained is preferably smaller than the thickness of the substrate (A1) 11 before stretching, and the substrate (A1). More preferably, it is smaller than half of the thickness of 11. By uniformly reducing the thickness of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence before stretching relative to the thickness of the substrate (A1) 11, uniform stretching is performed during the stretching process. be able to.

  The specific thickness of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence before stretching can be set according to the thickness of the non-liquid crystalline material layer (A2) obtained after stretching. Yes, preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 50 μm or less, more preferably 30 μm or less. By setting the thickness to be equal to or more than the lower limit of the above range, sufficient retardation and mechanical strength can be obtained in the layer (A2) 12 of the non-liquid crystalline material of the multilayer film (A) 10. Moreover, by setting it as the upper limit value or less, the scratch resistance and handling properties of the non-liquid crystalline material layer (A2) 12 of the multilayer film (A) 10 can be improved, the thickness can be reduced, and further the thickness Variations can be suppressed.

The base material (A1) 11 on which the layer (A2) of the non-liquid crystalline material having positive intrinsic birefringence is formed by drying is sent to the stretching unit 230. In the extending | stretching part 230, the process of extending | stretching the base material (A1) 11 is performed.
At this time, it is preferable to stretch the substrate (A1) 11 by gripping portions at both ends in the TD direction where the non-liquid crystalline material having a positive intrinsic birefringence is not developed. That is, it is preferable that the base material (A1) 11 is the only gripping part for stretching. When the base material (A1) 11 is stretched in such a state that the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence is formed on the base material (A1) 11, tension is applied to the base material (A1) 11. Is imposed, and the base material (A1) 11 is uniformly stretched. At this time, the uniform stretching of the base material (A1) 11 acts on the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence, and the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence is formed. Since the film is indirectly stretched, uniform stretching can be performed as compared with the case where the layer (A2) of the non-liquid crystalline material having positive intrinsic birefringence is directly stretched. That is, since the base material (A1) 11 plays a role like a relaxation layer, the stretching stress from the gripping portion of the base material (A1) 11 to the layer (A2) of the non-liquid crystalline material having positive intrinsic birefringence The way of transmission becomes gentle, and as a result, uniform stretching in the width direction becomes possible. In particular, when the thickness of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence with respect to the thickness of the base material (A1) 11 is relatively reduced and stretched, the base material (A1) 11 mainly This is particularly preferable because tension can be imposed and the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence can be stretched more uniformly.

  The stretching temperature is preferably in the range of the glass transition temperature ± 20 ° C. of the material forming the substrate (A1) 11, and is preferably not more than the glass transition temperature of the non-liquid crystalline material having a positive intrinsic birefringence. The specific stretching temperature is preferably 40 ° C. or higher, more preferably 80 ° C. or higher, particularly preferably 100 ° C. or higher, preferably 250 ° C. or lower, more preferably 220 ° C. or lower, particularly preferably 200 ° C. or lower. . By stretching at a glass transition temperature of the base material (A1) 11 of −20 ° C. or higher, stretching can be performed with a small tension. Further, in the base material (A1) 11, the concentration of stress at the boundary between the region where the layer (A2) of the non-liquid crystalline material having positive intrinsic birefringence is positive and the region where the layer is not formed can be suppressed. Damage to the material (A1) can be prevented. Furthermore, the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence can be reliably stretched by stretching at a glass transition temperature of the substrate (A1) 11 of 20 ° C. or lower. In addition, by stretching below the glass transition temperature of a non-liquid crystalline material having a positive intrinsic birefringence, the stretching can be controlled stably, and a desired retardation can be obtained without adding a load to the manufacturing process. Can do.

  The draw ratio is preferably 1.01 times or more, more preferably 1.03 times or more, particularly preferably 1.05 times or more, preferably 2 times or less, more preferably 1.7 times or less, particularly preferably. 1.5 times or less. By setting the draw ratio to be not less than the lower limit of the above range, the desired retardation can be stably expressed in the layer (A2) 12 of the non-liquid crystalline material. Moreover, by setting it as the upper limit value or less, it is possible to prevent stretching unevenness and make the retardation in the layer (A2) 12 of the non-liquid crystalline material uniform. Here, the number of stretching may be one time or two or more times.

  By the above stretching, retardation is developed in the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence, and the multilayer film (A) 10 having desired optical characteristics is obtained. In the multilayer film (A) 10, the in-plane slow axis of the layer (A 2) 12 of the non-liquid crystalline material having a positive intrinsic birefringence is usually parallel to the direction stretched by the stretching portion 230. .

Further, in this manufacturing method, steps other than those described above may be performed.
For example, after stretching, a relaxation step may be performed as necessary. In the relaxation step, the stretched base material (A1) 11 is held at a predetermined temperature for a predetermined time, and the base material (A1) 11 is contracted. In this case, the relaxation rate is preferably within 20%, the holding temperature is preferably in the range of the glass transition temperature ± 30 ° C. of the material forming the substrate (A1) 11, and the holding time is 1 second to 60 seconds. Is preferred.

  For example, after stretching, the obtained multilayer film (A) 10 is cooled to room temperature as necessary. The cooling rate and the cooling means are not particularly limited. However, if the tension at the time of stretching is suddenly released before cooling, the resulting multilayer film (A) 10 is likely to wrinkle. Therefore, before releasing the tension, some or all of the cooling process should be performed. Is preferred.

  The obtained multilayer film (A) 10 is usually wound into a roll and stored. In the multilayer film (A) 10 obtained by such a manufacturing method, the thickness variation of the layer (A2) 12 of the non-liquid crystal material is small, and the letter of the layer (A2) 12 of the non-liquid crystal material is small. The foundation is uniform.

[1.5.2. Example of production process of multilayer film (b)]
The multilayer film (B) usually has a step of obtaining a multilayer film comprising a resin layer (B2) and a layer (B1) of a non-liquid crystalline material having a negative intrinsic birefringence in this order, and the multilayer film is stretched. It can manufacture by the manufacturing method including a process. Among them, a multilayer film (b) comprising a resin layer (B2), a non-liquid crystalline material layer (B1) having a negative intrinsic birefringence and a resin layer (B2) in this order is produced, and the multilayer film (b) After stretching the film, it is preferable to peel off one resin layer (B2) from the stretched multilayer film (b) to obtain a multilayer film (B). The layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence generally has a low mechanical strength. However, the both sides of the layer (B1) of the non-liquid crystalline material are covered with the resin layer (B2), so that Breakage of the liquid crystal material layer (B1) can be reliably prevented. Further, since the non-liquid crystalline material layer (B1) can be protected by being sandwiched from both sides by the high-strength resin layer (B2), bleeding out from the non-liquid crystalline material layer (B1) can be effectively prevented. Here, the bleed out from the non-liquid crystalline material layer (B1) means that a part of the components (for example, a compounding agent) contained in the non-liquid crystalline material layer (B1) is the non-liquid crystalline material layer (B1). A phenomenon that exudes to the surface.

  FIG. 3 is a schematic view schematically showing an example of a production apparatus 300 for producing the multilayer film (b) 310. As shown in FIG. 3, when the multilayer film (b) 310 is manufactured, a manufacturing apparatus 300 including a film molding unit 320 and a stretching unit 330 can be used.

  The film molding unit 320 is an apparatus for manufacturing a multilayer film (b) including a resin layer (B2), a layer (B1) of a non-liquid crystalline material having a negative intrinsic birefringence, and a resin layer (B2) in this order. Production methods include, for example, coextrusion molding methods such as coextrusion T-die method, coextrusion inflation method and coextrusion lamination method; film lamination molding methods such as dry lamination; co-casting method; and resin solution on the resin film surface And the like, such as coating molding method such as coating. Among these methods, the coextrusion molding method is preferable from the viewpoint of manufacturing efficiency and preventing a volatile component such as a solvent from remaining in the film.

When employing the coextrusion molding method, the multilayer film (b) is obtained, for example, by coextruding a non-liquid crystalline material having a negative intrinsic birefringence and a resin that forms the resin layer (B2). Examples of the co-extrusion molding method include a co-extrusion T-die method, a co-extrusion inflation method, and a co-extrusion lamination method, and among them, the co-extrusion T-die method is preferable. Further, the coextrusion T-die method includes a feed block method and a multi-manifold method, but the multi-manifold method is particularly preferable in that variation in thickness can be reduced.
In FIG. 3, description will be made assuming that the multilayer film (b) 340 before stretching is manufactured by co-extruding the material from the die 321 onto the cooling roll 322.

  The stretching unit 330 is a device that can stretch the multilayer film (b) 340 before stretching. When the multilayer film (b) 340 before stretching is stretched, retardation is developed in the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence, and a desired multilayer film (b) is obtained. It is like that. Examples of the stretching performed in the stretching unit 330 include a method of uniaxial stretching in the MD direction using a difference in peripheral speed between rolls (longitudinal uniaxial stretching); uniaxial stretching in the TD direction using a tenter stretching machine. Method (lateral uniaxial stretching); method of performing longitudinal uniaxial stretching and transverse uniaxial stretching in order (sequential biaxial stretching); method of performing longitudinal uniaxial stretching and transverse uniaxial stretching simultaneously (simultaneous biaxial stretching); oblique to the MD direction A method of stretching in the direction (oblique stretching) can be employed. Here, “oblique direction” means a direction that is neither parallel nor orthogonal.

  When manufacturing a multilayer film (b) using such a manufacturing apparatus 300, the film forming part 320 coextrudes a non-liquid crystalline material having a negative intrinsic birefringence and a resin forming the resin layer (B2). Perform the process.

  In the case of coextrusion, in the extruder having a die, the melting temperature of the non-liquid crystalline material having a negative intrinsic birefringence and the resin forming the resin layer (B2) is the glass transition temperature of these non-liquid crystalline material and resin. It is preferable that the temperature is higher than 80 ° C, more preferably higher than 100 ° C, more preferably lower than 180 ° C, more preferably lower than 150 ° C. . By setting the melting temperature in the extruder to be equal to or higher than the lower limit of the above range, the fluidity of the resin can be sufficiently increased, and by setting the melting temperature to be equal to or lower than the upper limit, deterioration of the resin can be prevented.

  By coextrusion, a multilayer film (b) 340 before stretching provided with a resin layer (B2), a layer (B1) of a non-liquid crystalline material having a negative intrinsic birefringence and a resin layer (B2) in this order is obtained. It is done. In the obtained multilayer film (b) 340 before stretching, the thickness of the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence is the non-liquid crystalline material layer (B1) in the finally obtained laminate. ) And the thickness ratio of the resin layer (B2). The specific thickness of the layer (B1) of the non-liquid crystalline material is preferably 10 μm or more, more preferably 50 μm or more from the viewpoint of obtaining sufficient retardation and mechanical strength. From a viewpoint of making it favorable, Preferably it is 800 micrometers or less, More preferably, it is 600 micrometers or less.

  Further, in the multilayer film (b) 340 before stretching, the thickness per layer of the resin layer (B2) is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of obtaining sufficient mechanical strength. Moreover, from a viewpoint which makes a softness | flexibility and handling property favorable, Preferably it is 100 micrometers or less, More preferably, it is 50 micrometers or less.

  Furthermore, the total thickness of the multilayer film (b) 340 before stretching is preferably 20 μm or more, more preferably 70 μm or more, preferably 1000 μm or less, more preferably 700 μm or less. By setting it to the lower limit value or more of the above range, sufficient retardation and mechanical strength can be obtained, and by setting it to the upper limit value or less, flexibility and handling properties can be improved.

The obtained multilayer film (b) 340 before stretching is sent to the stretching section 330. In the extending | stretching part 330, the process of extending | stretching the multilayer film (b) 340 before extending | stretching is performed.
The stretching temperature is preferably Tg (B1) -20 ° C. or higher when expressed using the glass transition temperature Tg (B1) of the non-liquid crystalline material having a negative intrinsic birefringence forming the layer (B1). (B1) −15 ° C. or higher is more preferable, and Tg (B1) −13 ° C. or higher is further preferable. Further, it is preferably Tg (B1) + 20 ° C. or less, more preferably Tg (B1) + 2 ° C. or less, further preferably Tg (B1) −2 ° C. or less, and Tg (B1) -11. It is particularly preferable that the temperature is not higher than ° C.

  The draw ratio is preferably 1.2 times or more, more preferably 2.5 times or more, preferably 6 times or less, more preferably 5.0 times or less. When the draw ratio is within this range, a non-liquid crystalline material layer (B1) having a small thickness and a desired retardation can be obtained. Here, the number of stretching may be one time or two or more times.

  By the stretching, retardation is developed in the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence, and a multilayer film (b) 310 having desired optical characteristics is obtained. In this multilayer film (b) 310, the in-plane slow axis of the layer (B 1) of the non-liquid crystalline material having a negative intrinsic birefringence is usually perpendicular to the direction stretched by the stretching portion 330.

  Further, in this manufacturing method, steps other than those described above may be performed. For example, a preheat treatment may be performed on the multilayer film (b) 340 before stretching.

  The obtained multilayer film (b) 310 is usually wound into a roll and stored. In the multilayer film (b) 310 obtained by such a manufacturing method, the mechanical strength of the non-liquid crystalline material layer (B1) is low, but it is protected by the resin layer (B2), and is not easily damaged. It has become.

[1.5.3. Example of bonding process]
FIG. 4 is a schematic view schematically showing an example of an apparatus 400 for manufacturing the laminate 100 by laminating the multilayer film (A) 10 and the multilayer film (B) 20. As shown in FIG. 4, when manufacturing the laminated body 100, the manufacturing apparatus 400 provided with the peeling part 410, the coating part 420, the bonding part 430, and the hardening process part 440 can be used.

  The peeling part 410 is an apparatus for peeling one resin layer (B2) 450 from the multilayer film (b) 310 stretched as shown in FIG. When one resin layer (B2) 450 is peeled, one surface of the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence is exposed, and the non-liquid crystalline material layer (B1) and the resin layer are exposed. A multilayer film (B) 20 provided with (B2) is obtained.

  The coating unit 420 is a device that can apply an adhesive layer to the exposed surface of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence of the multilayer film (B) 20. That is, the coating part 420 applies the adhesive 460 to the surface 21D opposite to the resin layer (B2) of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence of the multilayer film (B). Can be crafted. Examples of the method for applying the adhesive layer include, but are not particularly limited to, a die coating method such as a roll coating method, a curtain coating method, and a slot coating method, a spray coating method, and the like.

  The bonding portion 430 includes an adhesive layer formed on the multilayer film (B) and a base material (A1) of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence of the multilayer film (A). This is an apparatus capable of bonding the opposite surface 12U. The laminating method by the laminating unit 430 can be performed by any laminating means. However, it is preferable to eliminate the air bubbles mixed during the bonding. For example, in the continuous laminating process such as the roll-to-roll method shown in FIG. 3, for example, (i) increasing the clamping pressure between the lami roll 431 and the counter roll 432, (ii) decreasing the laminating process speed, (iii) ) When the lami roll 431 is made of rubber and the counter roll 432 is made of metal, the multilayer film (A) is so thick that the total thickness of the multilayer film (B) 20 is larger than the total thickness of the multilayer film (A) 10. The mixing of bubbles can be suppressed by a method such as selecting 10 base materials (A1). Further, in the batch laminating process, for example, by adopting a technique such as (iv) increasing the surface pressure or (v) applying a vacuum, it is possible to suppress the mixing of bubbles.

  The curing processing unit 440 is a device that can perform a process of curing the adhesive included in the adhesive layer. The specific curing process can be performed appropriately according to the adhesive used. For example, when an active energy ray-curable adhesive such as ultraviolet rays is used, an apparatus that can uniformly irradiate the active energy rays in the TD direction can be used. Specific examples of the ultraviolet light source include 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 excitation mercury lamp, and a metal halide lamp.

  When manufacturing the laminated body 100 using such a manufacturing apparatus 400, manufacture by a roll toe roll method is possible using the elongate multilayer film (A) 10 and multilayer film (b) 310. For example, the multilayer film (b) 310 is pulled out from the roll of the multilayer film (b) 310, and the pulled multilayer film (b) 310 is sent to the peeling unit 410.

  In the peeling part 410, the process which peels one said resin layer (B2) 450 from the multilayer film (b) 310, and obtains the multilayer film (B) 20 is performed. The obtained multilayer film (B) 20 is sent to the coating unit 420. Moreover, the resin layer (B2) 450 peeled from the multilayer film (b) 310 is usually wound up and collected in a roll shape.

  In the coating part 420, an adhesive layer is applied to the surface 21D opposite to the resin layer (B2) of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence of the multilayer film (B) 20. . That is, the adhesive 460 is applied to the surface 21D of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence exposed by peeling off the resin layer (B2) 450, and the uncured adhesive 460 is removed. An adhesive layer is formed as a layer.

  The multilayer film (B) 20 coated with the adhesive layer is sent to the bonding portion 430. Further, the multilayer film (A) 10 drawn from the roll of the multilayer film (A) 10 has also been sent to the bonding portion 430. In the laminating portion 430, the multilayer film (B) 20 is sandwiched between the multilayer film (A) 10 and the multilayer film (B) 20 between the lami roll 431 and the counter roll 432, so that the intrinsic birefringence of the multilayer film (B) 20 is negative. The base layer (A1) of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence of the multilayer film (A) 10 and the adhesive layer formed on the surface 21D of the non-liquid crystalline material layer (B1) The opposite surface 12U is bonded. The layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence of the multilayer film (B) 20 has a low mechanical strength, but is reinforced by the resin layer (B2), and thus is damaged during bonding. There is nothing.

  At this time, the arithmetic average roughness Ra of the surface 12U on the side opposite to the base material (A1) of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence serving as a bonding surface in the multilayer film (A) 10. Is preferably 0.001 μm or more, more preferably 0.005 μm or more, preferably 0.1 μm or less, more preferably 0.05 μm or less. By setting the arithmetic average roughness Ra of the surface 12U of the layer (A2) of the non-liquid crystalline material to be equal to or higher than the lower limit of the above range, the slipping property between the multilayer film (A) and the roll during transportation can be improved. Moreover, haze can be made small by setting it as below an upper limit.

  In addition, the surface 21D opposite to the resin layer (B2) of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence of the multilayer film (B) 20 serving as a bonding surface in the multilayer film (B). The arithmetic average roughness Ra is preferably 0.0005 μm or more, more preferably 0.001 μm or more, preferably 0.1 μm or less, more preferably 0.05 μm or less. By setting the arithmetic average roughness Ra of the surface 21D of the layer (B1) of the non-liquid crystalline material to be equal to or higher than the lower limit of the above range, the slipping property between the multilayer film (B) and the roll during transportation can be improved. Moreover, haze can be made small by setting it as below an upper limit.

Thereafter, the multilayer film (A) 10 and the multilayer film (B) 20 bonded together by the adhesive layer are sent to the curing processing unit 440. In the example illustrated in FIG. 4, the curing processing unit 440 irradiates the adhesive layer with ultraviolet rays, and the adhesive layer is cured. At this time, the irradiation intensity of ultraviolet rays is preferably 50 mW / cm ² or more, more preferably 100 mW / cm ² or more, particularly preferably 300 mW / cm ² or more in a wavelength region effective for activating the polymerization initiator. preferably 5000 mW / cm ² or less, more preferably 3000 mW / cm ² or less, particularly preferably 2000 mW / cm ² or less. By making irradiation intensity more than the lower limit of the said range, processing time can be shortened and hardening reaction can fully advance. Moreover, by setting it as the upper limit value or less, for example, yellowing of the adhesive layer due to heat such as radiant heat from a light source or heat of polymerization reaction and a decrease in adhesive force due to curing shrinkage can be prevented. Further, the irradiation time can be set according to the curing state. Further, the integrated light amount expressed as the product of irradiation intensity and irradiation time is preferably 10 mJ / cm ² or more, more preferably 100 mJ / cm ² or more, particularly preferably 500 mJ / cm ² or more, preferably 5000 mJ / cm ² or less, more preferably 3000 mJ / cm ² or less, particularly preferably 2000 mJ / cm ² or less.

The adhesive layer is cured by the curing process. Therefore, the substrate (A1), the non-liquid crystalline material layer (A2) with positive intrinsic birefringence, the adhesive layer, the non-liquid crystalline material layer (B1) with negative intrinsic birefringence and the resin layer (B2) The laminated body 100 provided in order is obtained.
The obtained laminate 100 is usually wound into a roll and stored. Thus, in the manufacturing method mentioned above, it is possible to perform a manufacturing process continuously in MD direction by the production line by a long film using the roll toe roll method. For this reason, when manufacturing a laminated body, it is possible to perform a part or all of each process in-line simply and efficiently. Therefore, a laminated body can be manufactured stably and easily.

  The manufacturing method described above may further include an optional step. For example, a non-liquid crystalline material layer 12A opposite to the base (A1) of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence as a bonding surface and a non-liquid crystalline material layer having a negative intrinsic birefringence. A step of performing a surface treatment such as a corona treatment on the surface 21D opposite to the resin layer (B2) of (B1) may be included. Thereby, the adhesive force of a multilayer film (A) and a multilayer film (B) can be improved.

  Moreover, you may implement the manufacturing method mentioned above further changing. For example, an adhesive layer is first applied to the surface 12U opposite to the base material (A1) of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence, and the adhesive layer is formed into a multilayer film. (B) The surface 21D opposite to the resin layer (B2) of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence of 20 may be bonded. That is, the surface 12U opposite to the base material (A1) of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence of the multilayer film (A) and the intrinsic complex of the multilayer film (B). A step of applying an adhesive layer to one surface of the surface 21D opposite to the resin layer (B2) of the non-liquid crystalline material layer (B1) having a negative refraction, an adhesive layer, and an adhesive layer are applied. When performing the manufacturing method including the step of bonding the other surface that has not been worked, the adhesive layer may be applied to either the surface 12U or the surface 21D.

  Furthermore, for example, the laminate described above directly produces a multilayer film (B) having a non-liquid crystalline material layer (B1) and a resin layer (B2) one by one by coextrusion, and the multilayer film ( You may manufacture by bonding B) and a multilayer film (A) through an adhesive layer.

[2. Retardation film]
The retardation film of the present invention is obtained by peeling the substrate (A1) and the resin layer (B2) from the above-described laminate. Therefore, the retardation film includes a non-liquid crystalline material layer (A2) having a positive intrinsic birefringence, an adhesive layer, and a non-liquid crystalline material layer (B1) having a negative intrinsic birefringence in this order. In the above-described laminate, the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence and the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence are thin and have a desired retardation. Uniformly in the plane. Therefore, the retardation film obtained from this laminate has desired optical performance, is thin, and can be stably manufactured.

  From the viewpoint of use as an optical film, the retardation film preferably has a total light transmittance of 85% or more, more preferably 92% or more, and usually 100% or less. Here, the total light transmittance of the retardation film was measured at five locations using “turbidimeter NDH-300A” manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS K7361-1997, and the average value obtained therefrom. It is.

  The haze of the retardation film is preferably 1% or less, more preferably 0.8% or less, particularly preferably 0.5% or less, and usually 0% or more. By setting the haze to a low value, the sharpness of the display image of the display device incorporating the retardation film can be improved. Here, the haze is an average value obtained by measuring five points using a “turbidimeter NDH-300A” manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS K7361-1997.

  In the retardation film, ΔYI is preferably 5 or less, more preferably 3 or less, and usually 0 or more. When this ΔYI is in the above range, there is no coloring and visibility can be improved. Here, ΔYI is obtained as an arithmetic average value by performing the same measurement five times using “Spectral Color Difference Meter SE2000” manufactured by Nippon Denshoku Industries Co., Ltd. according to ASTM E313.

  The thickness of the retardation film is usually 5 μm or more, preferably 8 μm or more, more preferably 10 μm or more, and usually 500 μm or less, preferably 80 μm or less, more preferably 50 μm or less, and particularly preferably 20 μm or less.

[3. Polarizer]
FIG. 5 is a diagram schematically showing a cross section of the polarizing plate according to one embodiment of the present invention, taken along a plane perpendicular to the main surface. As shown in FIG. 5, the polarizing plate 500 includes a polarizer 510 and the retardation film 520. The basic structure of the polarizing plate 500 is obtained by bonding the retardation film 520 of the present invention serving as a protective layer to one or both sides of the polarizer 510 through an adhesive layer or an adhesive layer 530 as necessary. is there. At this time, the direction of the retardation film 520 is arbitrary, and as shown in FIG. 5, the retardation film 520 is bonded to the polarizer 510 on the non-liquid crystalline material layer (A2) 12 side having a positive intrinsic birefringence. Alternatively, it may be bonded to the polarizer 510 on the side of the layer (B1) 21 of the non-liquid crystalline material which is opposite and has a negative intrinsic birefringence.

  Examples of the polarizer include, for example, an appropriate vinyl alcohol polymer film such as polyvinyl alcohol and partially formalized polyvinyl alcohol, a dyeing treatment with a dichroic substance such as iodine or a dichroic dye, a stretching treatment, a crosslinking treatment, and the like. Are applied in an appropriate order and manner. Such a polarizer is capable of transmitting linearly polarized light when natural light is incident thereon, and in particular, a polarizer excellent in light transmittance and degree of polarization is preferable. The thickness of the polarizer is generally 5 μm to 80 μm, but is not limited thereto.

  The retardation film of the present invention is adhered to at least one side of the polarizer, but an optional protective layer may be provided on the other side. Any transparent film can be used as the protective layer. Among these, a resin film excellent in transparency, mechanical strength, thermal stability, moisture shielding properties and the like is preferable. Examples of such resins include acetate resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and polymers having an alicyclic structure. Examples thereof include resins and acrylic resins. Among them, an acetate resin, a polymer resin having an alicyclic structure, and an acrylic resin are preferable in terms of low birefringence. From the viewpoint of transparency, low hygroscopicity, dimensional stability, lightness, and the like, an alicyclic structure is preferable. Particularly preferred are polymer resins having The thickness of the protective layer is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 150 μm or less, and usually 5 μm or more, from the viewpoint of thinning the polarizing plate.

  Any adhesive or pressure-sensitive adhesive layer can be used as the adhesive layer or the pressure-sensitive adhesive layer. Examples of the adhesive or pressure-sensitive adhesive include acrylic, silicone, polyester, polyurethane, polyether, rubber, and the like. Among these, an acrylic type is preferable from the viewpoint of heat resistance and transparency.

  In the polarizing plate, the slow axis in the plane of the retardation film and the transmission axis of the polarizer are usually parallel or orthogonal.

  The thickness of the polarizing plate (the protective layer, the polarizer, the adhesive layer, the non-liquid crystalline material layer (A2) having positive intrinsic birefringence, the adhesive layer, the non-liquid crystalline material layer (B1) having negative intrinsic birefringence) The thickness of the polarizing plate provided in order is preferably 70 μm or more, more preferably 80 μm or more, particularly preferably 90 μm or more, preferably 150 μm or less, more preferably 140 μm or less, and particularly preferably 120 μm or less. By using the retardation film of the present invention, such a thin polarizing plate can be realized.

  Such a polarizing plate, for example, peels off the base material (A1) or the resin layer (B2) from the laminate of the present invention, and thereby the surface of the layer (A2) of the non-liquid crystalline material having positive intrinsic birefringence exposed Or it can manufacture easily by sticking a polarizer on the surface of the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence, and further peeling off unnecessary layers as necessary. Bonding may be performed by batch-bonding films cut to a desired size, or by a roll-to-roll method using a long film.

[4. LCD panel]
FIG. 6 is a diagram schematically showing a cross section of the liquid crystal panel according to one embodiment of the present invention, taken along a plane perpendicular to the main surface. As shown in FIG. 6, the liquid crystal panel 600 includes a liquid crystal cell 610 and the polarizing plate 500. At this time, the orientation of the polarizing plate 500 is arbitrary, and a retardation film 520 may be provided between the polarizer 510 and the liquid crystal cell 610 as shown in FIG.

  Liquid crystal cells include in-plane switching (IPS) type, vertical alignment (VA) type, multi-domain vertical alignment (MVA) type, continuous spin wheel alignment (CPA) type, twisted nematic (TN) type, super twisted nematic ( STN) type, hybrid alignment nematic (HAN) type, optical compensated bend (OCB) type, and the like. Among these, it can be particularly preferably applied to an IPS type liquid crystal cell.

  In general, an ISP liquid crystal cell includes a liquid crystal layer including liquid crystal molecules that are homogeneously aligned in the horizontal direction. In addition, an IPS liquid crystal panel including such an IPS liquid crystal cell generally includes two polarizers whose transmission axes point vertically and horizontally with respect to the front of the screen. . Therefore, when the screen of the IPS liquid crystal panel is viewed obliquely from the top, bottom, left, and right directions, the two transmission axes of the polarizer are in a positional relationship that they appear to be orthogonal, so a liquid crystal layer having a homogeneous orientation is, for example, a twisted Birefringence generated in the liquid crystal cell is reduced, and sufficient contrast can be obtained. On the other hand, when the screen is viewed obliquely from a direction having an azimuth angle of 45 ° with respect to the transmission axis of the polarizer, the angle formed by the transmission axes of the two polarizers is apparently shifted from 90 °. Therefore, conventionally, linearly polarized light is not completely blocked, light leakage occurs, and sufficient black cannot be obtained, resulting in a decrease in contrast.

  In contrast, in the IPS liquid crystal panel, by providing the retardation film of the present invention as an optical compensation film, compensation of retardation caused by the liquid crystal in the liquid crystal cell and orthogonal arrangement of the transmission axes of the two polarizers are achieved. Compensation can be performed. Therefore, it is possible to effectively compensate for the birefringence generated in the transmitted light to prevent light leakage and to obtain high contrast at all azimuth angles. This effect is considered to be obtained in other types of liquid crystal panels as well, but the effect is particularly remarkable in the IPS type.

  The retardation film of the present invention can be applied to a liquid crystal panel having an arbitrary structure such as a transmission type, a reflection type, or a transmission / reflection type in which a polarizer is disposed on one side or both sides of a liquid crystal cell. In addition, a liquid crystal display device can be configured by combining the liquid crystal panel with components such as a prism array sheet, a lens array sheet, a light diffusion plate, a backlight, and a brightness enhancement film.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples described below, and is within the scope of the claims of the present invention and the equivalents thereof. You may carry out by changing arbitrarily.
In the following description, “%” and “part” representing amounts are based on weight unless otherwise specified. In addition, the operations described below were performed under normal temperature and normal pressure conditions unless otherwise specified. Furthermore, co-extrusion molding of two types and three layers refers to producing a multilayer film having three layers by co-extrusion of two types of resins. The surface roughness Ra represents the arithmetic average roughness specified in JIS B0601-1994.

[Measuring method]
[Measurement method of retardation]
The retardation in the in-plane direction and the thickness direction of each layer of the film were measured at a wavelength of 550 nm using an automatic birefringence meter (Oji Scientific Instruments “KOBRA-21ADH”). The measurement was performed at five points near the center in the width direction of the film, and the average value was taken as the measurement value.
The layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence was measured by the following method. The resin layer (B2) was peeled from the multilayer film (B) to obtain a non-liquid crystalline material layer (B1) having a negative intrinsic birefringence. The value obtained by measuring the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence obtained in this manner was taken as the measured value.
Further, the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence was measured by the following method. The layer (A2) side of the non-liquid crystalline material having a positive intrinsic birefringence of the multilayer film (A) was attached to the glass substrate via an adhesive layer, and the base material (A1) was peeled off. Thus, a composite of glass substrate / adhesive layer / non-liquid crystalline material layer (A2) having a positive intrinsic birefringence was prepared as a sample. The value measured with this sample was taken as the measured value.

[Method of measuring peel force]
The peeling force was measured at a peeling speed of 100 mm / min and a sample width of 20 mm in accordance with JIS K6855-2.

(Tensile elongation at break)
The tensile breaking elongation was based on JIS K7162, and the test piece was prepared based on JIS K7127-1B. The tensile speed was measured as 5 mm / min.

[Example 1]
[1.1. Production of multilayer film comprising layer (B1) and layer (B2)]
(Preparation of resin)
70 parts of amorphous polystyrene (“HH102” manufactured by PS Japan Co., Ltd.) and 30 parts of poly (2,6-dimethyl-1,4-phenylene oxide) (manufactured by Aldrich) were kneaded with a twin screw extruder. Then, a transparent thermoplastic resin (X) pellet was produced. This resin (X) is a non-liquid crystalline material having a negative intrinsic birefringence. The glass transition temperature of resin (X) was 134 ° C.

As a thermoplastic resin (Y), pellets of methacrylic resin (glass transition temperature 105 ° C.) containing polymethyl methacrylate and rubber particles were put into one uniaxial extruder of a film molding apparatus and melted.
The resin (X) pellets were charged into the other uniaxial extruder of the film molding apparatus and melted.

(Co-extrusion process)
A film forming apparatus for coextrusion molding of two types and three layers was prepared.
The molten thermoplastic resin (Y) was supplied to one manifold of a multi-manifold die (die slip surface roughness Ra = 0.1 μm) of a film forming apparatus through a leaf disk-shaped polymer filter having an opening of 10 μm. .
In addition, the melted resin (X) was supplied to the other manifold of the film forming apparatus through a leaf disk-shaped polymer filter having an opening of 10 μm.

  The thermoplastic resin (Y) and the resin (X) are simultaneously extruded from the multi-manifold die at 260 ° C. while adjusting the extrusion conditions so that a resin layer having a desired thickness is obtained. The film was formed into a film having a three-layer structure of layer (B2) / layer (B1) of resin (X) / layer (B2) of thermoplastic resin (Y). The molten resin coextruded in the form of a film in this way was cast on a cooling roll adjusted to a surface temperature of 115 ° C., and then passed between two cooling rolls adjusted to a surface temperature of 120 ° C. Thereby, the layer (B2) of the thermoplastic resin (Y), the layer (B1) of the resin (X) as a non-liquid crystalline material having a negative intrinsic birefringence, and the layer (B2) of the thermoplastic resin (Y) A multilayer film (b) having a three-layer structure provided in this order was obtained.

(Stretching process)
Next, the multi-layer film (b) is pulled up by 1.8 times in the longitudinal direction using a tenter stretching machine while adjusting the tension and the tenter chain tension so that an in-plane slow axis parallel to the TD direction can be obtained by stretching. The film was biaxially stretched 1.1 times in the transverse direction. The temperature during stretching was 131 ° C., which is 3 ° C. lower than the glass transition temperature of the resin (X) as a non-liquid crystalline material having a negative intrinsic birefringence.

  The thickness of each layer of the thus stretched multilayer film (b), the in-plane direction retardation Re and the thickness direction retardation Rth were measured. The results are shown in Table 1.

[1.2. Production of multilayer film (A)]
100 parts of a polycarbonate resin (“Iupizeta PCZ200” manufactured by Mitsubishi Gas Chemical Co., Ltd .; glass transition temperature of 137 ° C.) as a non-liquid crystalline material having a positive intrinsic birefringence was mixed with 400 parts of toluene to obtain a resin solution.

  On the base film (A1) (“Zeonor film” manufactured by Nippon Zeon Co., Ltd., thickness 80 μm, glass transition temperature 138 ° C.) formed of a norbornene-based resin as a polymer resin having an alicyclic structure Was applied so that the dry film thickness was 6 μm to form a resin solution film. The membrane of this resin solution was dried at 80 ° C. for 2 minutes to obtain a multilayer film (a) comprising a base film (A1) and a polycarbonate resin layer (A2).

  The multilayer film (a) was stretched by a tenter stretching machine at a stretching temperature of 145 ° C. and a stretching ratio of 2.7 times in the TD direction. This obtained the multilayer film (A) of the 2 layer structure of base film (A1) / polycarbonate resin layer (A2). At this time, the thickness of the polycarbonate resin layer (A2) layer was 5 μm.

[1.3. Lamination]
One layer (B2) is peeled from the multilayer film having a three-layer structure of layer (B2) / layer (B1) / layer (B2), and a multilayer having layers (B1) and (B2) is provided. A film (B) was obtained. The surface of the layer (B1) exposed by peeling off one of the layers (B2) was subjected to corona treatment (paint index 56 dyne / cm). An active energy ray-curable adhesive (“Aronix M-6100” manufactured by Toagosei Co., Ltd.) was applied to the surface of the layer (B1) subjected to the corona treatment with a thickness of 5 μm to form an adhesive layer.

  On the other hand, the surface of the polycarbonate resin layer (A2) of the multilayer film (A) was subjected to corona treatment (painting index 56 dyne / cm). The surface of the polycarbonate resin layer (A2) subjected to this corona treatment was bonded to the adhesive layer. In this bonding, the in-plane slow axis of the polycarbonate resin layer (A2) and the in-plane slow axis of the resin (X) layer (B1) were made parallel. By making them parallel, it is inevitably possible to perform roll-to-roll bonding.

After the bonding, the layer (B2) and the layer are irradiated by irradiating the surface on the layer (B2) side with an ultraviolet irradiation device (Conveyor UV, manufactured by Fusion UV Systems Japan Co., Ltd., integrated light quantity 350 mJ / cm ² ). The adhesive layer was irradiated with ultraviolet rays via (B1). Thereby, the adhesive layer is cured, and the base film (A1), the polycarbonate resin layer (A2), the adhesive layer, the resin (X) layer (B1), and the thermoplastic resin (Y) layer (B2) are arranged in this order. The laminated body provided was obtained.

[1.4. Production of polarizing plate]
The base film (A1) was peeled from the produced laminate. The surface of the polycarbonate resin layer (A2) exposed by peeling off the base film (A1) was subjected to corona treatment (paint index 56 dyne / cm). A water-based adhesive was applied to the edge of the surface of the polycarbonate resin layer (A2) subjected to the corona treatment so as to have a dry film thickness of 0.1 μm. This water-based adhesive is an aqueous solution in which 100 parts of “Gosefimer Z-200” manufactured by Nihon Gosei Co., Ltd. and 1 part of glyoxal GX are dissolved in 4949 parts of pure water. A film comprising a triacetylcellulose layer with a hard coat (thickness 50 μm) and a polarizer (thickness 25 μm) is prepared, and the surface of the polarizer of this film and the surface of the polycarbonate resin layer (A2) are arranged to face each other. And laminated with a laminator. When laminating, the in-plane slow axis of the laminate comprising the polycarbonate resin layer (A2), the adhesive layer, the resin (X) layer (B1) and the thermoplastic resin (Y) layer (B2) in this order is: It was made to be parallel to the transmission axis of the polarizer. Thereafter, the thermoplastic resin (Y) layer (B2) is peeled off, and the triacetylcellulose layer, the polarizer, the adhesive layer, the polycarbonate resin layer (A2), the adhesive layer, and the resin (X) layer (B1) are peeled off. A polarizing plate provided in this order was obtained. The obtained polarizing plate had a thickness of 96 μm.

[1.5. Manufacture of IPS liquid crystal panel]
The exit side polarizing plate was peeled from the IPS liquid crystal panel of a commercially available IPS mode liquid crystal display device. The polarizing plate from which the layer (B2) was peeled was bonded to the surface of the IPS liquid crystal panel from which the outgoing-side polarizing plate was peeled. At the time of bonding, the surface of the resin (X) layer (B1) of the polarizing plate faced the liquid crystal cell. In addition, the transmission axis of the polarizing plate to be bonded and the transmission axis of the incident side polarizing plate of the IPS liquid crystal panel were set to be crossed Nicols. Furthermore, the bonding was performed using an adhesive layer (“MO-T006C” manufactured by Lintec Corporation, thickness 25 μm). Thereby, the incident side polarizing plate, the IPS type liquid crystal cell, the adhesive layer, the layer (B1) of the resin (X), the adhesive layer, the polycarbonate resin layer (A2), the adhesive layer, the polarizer, and the triacetyl cellulose layer in this order. A liquid crystal display device having an IPS liquid crystal panel was obtained.

When the display characteristics of the obtained liquid crystal display device were visually confirmed, the display was good and uniform both when viewed from the front and when viewed from an oblique angle in the range of polar angles of 0 ° to 80 ° in all directions. Met.
In order to evaluate the light leakage of this liquid crystal display device, the screen during black display was measured at an azimuth angle of 45 ° and a polar angle of −60 ° to 60 ° with respect to the transmission axis of the output side polarizing plate of the liquid crystal panel. As a result, the maximum value Ymax of the measured luminance was 0.55 (candela / m ² ).

[Example 2]
As the non-liquid crystalline material having a negative intrinsic birefringence, a styrene-maleic anhydride copolymer (“Deraque D332” manufactured by Nova Chemical Japan, glass transition temperature 130 ° C.) was used instead of the resin (X). Further, the stretching temperature of the multilayer film (b) was changed to 127 ° C.
A liquid crystal display device was manufactured and evaluated in the same manner as in Example 1 except for the above items.

[Example 3]
100 parts of bismaleimide resin (UV-cured product of “BMI 1500” manufactured by Air Brown; glass transition temperature 90 ° C.), 1 part of photopolymerization initiator (“Irg907” manufactured by BASF Japan), 202 parts of toluene, acetic acid The resin solution was obtained by mixing 202 parts of ethyl. In the production of the multilayer film (A), this resin solution was used in place of the resin solution containing the polycarbonate resin as the resin solution containing the non-liquid crystalline material having a positive intrinsic birefringence. The film thickness of the bismaleimide resin layer after stretching was 4 μm.
Further, in the production of the multilayer film (A), a norbornene-based resin film (A1) (“Zeonor Film” manufactured by Nippon Zeon Co., Ltd., thickness 80 μm, glass transition temperature 105 ° C.) was used as the base film.
A liquid crystal display device was manufactured and evaluated in the same manner as in Example 1 except for the above items. The thickness of the polarizing plate was 95 μm.

[Example 4]
Instead of the thermoplastic resin (Y), a norbornene resin (“Zeonor” manufactured by Nippon Zeon Co., Ltd .; glass transition temperature 105 ° C.) was used.
A liquid crystal display device was manufactured and evaluated in the same manner as in Example 1 except for the above items.

[Comparative Example 1]
In the same manner as in Step [1.1] of Example 1, the layer (B2) of thermoplastic resin (Y) / amorphous polystyrene (“HH102” manufactured by PS Japan) and poly (2,6-dimethyl- A multilayer film having a three-layer structure of resin (X) layer (B1) / thermoplastic resin (Y) layer (B2) containing 1,4-phenylene oxide was obtained.

Corona treatment (paint index 56 dyne / cm) was applied to the surface of one layer (B2) of the multilayer film having a three-layer structure of layer (B2) / layer (B1) / layer (B2). An active energy ray-curable adhesive (“Aronix M-6100” manufactured by Toagosei Co., Ltd.) was applied to the surface of the corona-treated layer (B2) to form an adhesive layer. On the other hand, the surface of the polycarbonate resin layer (A2) of the multilayer film (A) similar to that in Example 1 was subjected to corona treatment (wetting index 56 dyne / cm). The surface of the polycarbonate resin layer (A2) subjected to this corona treatment was bonded to the adhesive layer. After bonding, the adhesive layer was irradiated with ultraviolet rays by an ultraviolet irradiation device under the same conditions as in Example 1. Thereby, the adhesive layer is cured, and the base film (A1), the polycarbonate resin layer (A2), the adhesive layer, the layer (B2) of the thermoplastic resin (Y), the layer (B1) of the resin (X), and the thermoplastic resin. The laminated body provided with the layer (B2) of resin (Y) in this order was obtained.
A polarizing plate was produced in the same manner as in Step [1.4] of Example 1 except that the laminate thus obtained was used. The thickness of this polarizing plate was 102 μm.
A liquid crystal display device was produced and evaluated in the same manner as in Step [1.5] of Example 1 except that the polarizing plate thus obtained was used.

When the display characteristics of the obtained liquid crystal display device were visually confirmed, the display was good and uniform both when viewed from the front and when viewed from an oblique angle in the range of polar angles of 0 ° to 80 ° in all directions. Met.
In order to evaluate the light leakage of this liquid crystal display device, the screen during black display was measured at an azimuth angle of 45 ° and a polar angle of −60 ° to 60 ° with respect to the transmission axis of the output side polarizing plate of the liquid crystal panel. As a result, the maximum value Ymax of the measured luminance was 0.60 (candela / m ² ).

[result]
The results of Examples and Comparative Examples are shown in Table 2. Here, in Table 2, the meanings of the abbreviations are as follows.
Tg difference of film (B): difference in glass transition temperature calculated by “glass transition temperature of layer (B1) of non-liquid crystalline material having negative intrinsic birefringence−glass transition temperature of resin layer (B2)”.
Tg difference of film (A): difference in glass transition temperature calculated by “glass transition temperature of layer (A2) of non-liquid crystalline material having positive intrinsic birefringence−glass transition temperature of substrate (A1)”.
Re (550 nm): In-plane retardation measured at a wavelength of 550 nm.
Rth (550 nm): retardation in the thickness direction measured at a wavelength of 550 nm.
MAA resin: Methacrylic resin NBR resin: Norbornene resin PC resin: Polycarbonate resin BMI resin: Bismaleimide resin

[Consideration]
As can be seen from Table 2, in Examples 1 to 4, the contrast of the IPS liquid crystal panel can be improved. Therefore, it was confirmed that the retardation films according to Examples 1 to 4 have optical characteristics that enable optical compensation of the IPS liquid crystal panel. The retardation films according to Examples 1 to 4 each have a base material (A1), a non-liquid crystal material layer (A2), an adhesive layer, a non-liquid crystal material layer (B1), and a resin layer (B2). It was confirmed that the laminate can be easily manufactured from the provided laminate and that the thickness can be reduced.

10 Multi-layer film (A)
11 Substrate (A1)
11U Surface of base material (A1) 12 Layer of non-liquid crystalline material with positive intrinsic birefringence (A2)
12U Surface of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence on the side opposite to the base material (A1) 20 Multilayer film (B)
21 Layer of non-liquid crystalline material with negative intrinsic birefringence (B1)
21D Surface of the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence opposite to the resin layer (B2) 22 Resin layer (B2)
DESCRIPTION OF SYMBOLS 30 Adhesive layer 100 Laminated body 200 Manufacturing apparatus of multilayer film (A) 210 Expanding section 220 Drying section 230 Stretching section 240 Solution 250 Film before stretching 300 Manufacturing apparatus of multilayer film (b) 310 Multilayer film after stretching (b )
320 Film forming part 321 Die 322 Cooling roll 330 Stretching part 340 Multilayer film (b) before stretching
DESCRIPTION OF SYMBOLS 400 Manufacturing apparatus of laminated body 410 Peeling part 420 Coating part 430 Bonding part 431 Lami roll 432 Pair roll 440 Curing process part 450 Resin layer (B2)
460 Adhesive 500 Polarizing plate 510 Polarizer 520 Retardation film 530 Adhesive layer or adhesive layer 600 Liquid crystal panel 610 Liquid crystal cell

Claims (16)

A multilayer film (A) comprising a base material (A1) and a layer (A2) of a non-liquid crystalline material having a positive intrinsic birefringence in contact with the base material (A1);
A multilayer film (B1) comprising a non-liquid crystalline material layer (B1) having a negative intrinsic birefringence and a resin layer (B2) in contact with the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence )When,
The surface of the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence opposite to the base (A1) and the resin in the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence A single adhesive layer interposed between the surface opposite to the layer (B2);
A laminate comprising:   The laminate according to claim 1, wherein a peeling force between the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence and the resin layer (B2) is 0.5 N / 20 mm or less.   The laminate according to claim 1 or 2, wherein a peeling force between the base material (A1) and the layer (A2) of the non-liquid crystalline material having a positive intrinsic birefringence is 0.05 N / 20 mm or less.   The difference between the glass transition temperature of the material of the substrate (A1) and the glass transition temperature of the non-liquid crystalline material having a positive intrinsic birefringence is in the range of + 15 ° C to -15 ° C. The laminated body as described in any one.   The relationship between the glass transition temperature Tg (B1) of the non-liquid crystalline material having a negative intrinsic birefringence and the glass transition temperature Tg (B2) of the resin of the resin layer (B2) is Tg (B1)> Tg (B2). The laminated body as described in any one of Claims 1-4 satisfy | filled +20 degreeC.   The laminate according to any one of claims 1 to 5, wherein the non-liquid crystalline material layer (B1) having a negative intrinsic birefringence has a tensile elongation at break of 20% or less.   The base material (A1) is composed of a polymer resin having an alicyclic structure, a (meth) acrylic resin, a polycarbonate resin, a (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and a polyethersulfone resin. The laminated body as described in any one of Claims 1-6 currently formed with resin selected more.   The non-liquid crystalline material having a positive intrinsic birefringence is selected from the group consisting of a polyimide resin, a maleimide resin, a polyamideimide resin, a polycarbonate resin, a polyester resin, and a polyurethane urea resin. The laminated body as described in.   A polymer obtained by polymerizing one or more monomers selected from the group consisting of styrenes, styrenes-maleic acid, maleimides and (meth) acrylic acid esters, wherein the non-liquid crystalline material having a negative intrinsic birefringence, and The laminate according to any one of claims 1 to 8, which is a mixture comprising at least one polymer selected from the group consisting of a polycarbonate polymer, a polyester polymer, and a polyarylene ether polymer.   The resin layer (B2) is composed of a polymer resin having an alicyclic structure, a (meth) acrylic resin, a polycarbonate resin, a (meth) acrylic acid ester-vinyl aromatic compound copolymer resin, and a polyethersulfone resin. The laminate according to any one of claims 1 to 9, which is formed of a resin selected from the group. It is a manufacturing method of the layered product according to any one of claims 1 to 10,
Developing a solution prepared by dissolving a non-liquid crystalline material having a positive intrinsic birefringence in a solvent on the substrate (A1);
Drying the developed solution;
Stretching the substrate (A1) after drying the solution to obtain the multilayer film (A);
Manufacturing method. It is a manufacturing method of the layered product according to any one of claims 1 to 10,
The non-liquid crystalline material having a negative intrinsic birefringence and the resin forming the resin layer (B2) are coextruded to form the resin layer (B2) and the non-liquid crystalline material layer having a negative intrinsic birefringence (B1). And a step of obtaining a multilayer film (b) comprising the resin layer (B2) in this order;
Stretching the multilayer film (b);
Peeling the one resin layer (B2) from the stretched multilayer film (b) to obtain the multilayer film (B);
Manufacturing method. It is a manufacturing method of the layered product according to any one of claims 1 to 10,
The surface of the non-liquid crystalline material layer (A2) having a positive intrinsic birefringence opposite to the base (A1) and the layer (B1) of the non-liquid crystalline material having a negative intrinsic birefringence. A step of forming the adhesive layer on one surface of the surface opposite to the resin layer (B2);
Bonding the adhesive layer and the other surface on which the adhesive layer is not formed;
Manufacturing method.   The retardation film from which the said base material (A1) and the said resin layer (B2) were peeled from the laminated body as described in any one of Claims 1-10.   A polarizing plate comprising a polarizer and the retardation film according to claim 14.   An IPS liquid crystal panel comprising: an IPS liquid crystal cell; and the polarizing plate according to claim 15.

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