JP6503410B2 - Resin laminate, display device and polarizing plate - Google Patents

Description

  The present invention relates to, for example, a resin laminate suitably used in a display device, a display device including the resin laminate, and a polarizing plate with a resin laminate in which the resin laminate and the polarizing plate are laminated.

  In recent years, display devices such as smartphones, portable game machines, audio players, tablet terminals and the like are increasingly equipped with touch screens. Although a glass sheet is usually used on the surface of such a display device, development of a plastic sheet which is a substitute for the glass sheet has been carried out from the viewpoint of weight reduction and processability of the display device. For example, Patent Document 1 discloses a transparent sheet containing a methacrylic resin and a vinylidene fluoride resin as a plastic sheet to be a substitute for a glass sheet.

JP, 2013-244604, A

  Display devices are used in various environments because of their high versatility. When a display device including a plastic sheet is used in a severe environment such as high temperature and high humidity, for example, warpage may occur as the resin expands and contracts. In recent years, thinning of a display device has been desired, and warpage has become a larger problem. An object of the present invention is to provide a resin laminate which is less likely to be warped, which is suitably used in a display device.

  MEANS TO SOLVE THE PROBLEM The present inventors repeated examination in detail about the resin laminated body suitably used in a display apparatus, in order to solve the said subject, and came to complete this invention.

［式中、
Ｌ_Ｂ及びＬ_Ｃは、それぞれ、熱可塑性樹脂層（Ｂ）及び（Ｃ）の膜厚の平均値を表し、
Δλ_Ｂは次の式：

で表され、
Δλ_Ｃは次の式：

で表され、
λ’_Ｂ及びλ’_Ｃは、それぞれ、樹脂積層体における熱可塑性樹脂層（Ｂ）及び（Ｃ）について測定した複屈折（Ｉ）を表し、
λ_Ｂ及びλ_Ｃは、それぞれ、熱可塑性樹脂層（Ｂ）及び（Ｃ）のビカット軟化温度より２５℃低い温度で４時間のアニール処理後の樹脂積層体における熱可塑性樹脂層（Ｂ）及び（Ｃ）について測定した複屈折（ＩＩ）を表し、
Ｔ_Ｂ及びＴ_Ｃは、それぞれ、熱可塑性樹脂層（Ｂ）及び（Ｃ）のビカット軟化温度を表す。］
を満たす、樹脂積層体。
［２］中間層（Ａ）は、該中間層（Ａ）に含まれる全樹脂に基づいて、３５〜４５質量％の（メタ）アクリル樹脂及び６５〜５５質量％のフッ化ビニリデン樹脂を含む、前記［１］に記載の樹脂積層体。
［３］中間層（Ａ）におけるアルカリ金属の含有量が、該中間層（Ａ）に含まれる全樹脂に基づいて５０ｐｐｍ以下である、前記［１］又は［２］に記載の樹脂積層体。
［４］（メタ）アクリル樹脂が、
（ａ１）メタクリル酸メチルの単独重合体、及び／又は
（ａ２）重合体を構成する全構造単位に基づいて５０〜９９.９質量％のメタクリル酸メチルに由来する構造単位、及び、０．１〜５０質量％の式（１）：

［式中、Ｒ_１は水素原子又はメチル基を表し、Ｒ_１が水素原子のときＲ_２は炭素数１〜８のアルキル基を表し、Ｒ_１がメチル基のときＲ_２は炭素数２〜８のアルキル基を表す。］
で示される（メタ）アクリル酸エステルに由来する少なくとも１つの構造単位を含む共重合体
である、前記［１］〜［３］のいずれかに記載の樹脂積層体。
［５］フッ化ビニリデン樹脂はポリフッ化ビニリデンである、前記［１］〜［４］のいずれかに記載の樹脂積層体。
［６］フッ化ビニリデン樹脂のメルトマスフローレイトは、３.８ｋｇ荷重、２３０℃で測定して、０.１〜４０ｇ／１０分である、前記［１］〜［５］のいずれかに記載の樹脂積層体。
［７］樹脂積層体の膜厚の平均値が１００〜２０００μｍであり、熱可塑性樹脂層（Ｂ）及び（Ｃ）の膜厚の平均値がそれぞれ１０〜２００μｍである前記［１］〜［６］のいずれかに記載の樹脂積層体。
［８］熱可塑性樹脂層（Ｂ）及び（Ｃ）に含まれる熱可塑性樹脂のビカット軟化温度がそれぞれ１００〜１６０℃である、前記［１］〜［７］のいずれかに記載の樹脂積層体。
［９］熱可塑性樹脂層（Ｂ）及び（Ｃ）は（メタ）アクリル樹脂層又はポリカーボネート樹脂層である、前記［１］〜［８］のいずれかに記載の樹脂積層体。
［１０］熱可塑性樹脂層（Ｂ）及び（Ｃ）はポリカーボネート樹脂層であり、それぞれの熱可塑性樹脂層に含まれる全樹脂に基づいて０．００５〜２．０質量％の紫外線吸収剤を含む、前記［１］〜［９］のいずれかに記載の樹脂積層体。
［１１］熱可塑性樹脂層（Ｂ）及び（Ｃ）は、それぞれの熱可塑性樹脂層に含まれる全樹脂に基づいて５０質量％以上の（メタ）アクリル樹脂を含む、前記［１］〜［９］のいずれかに記載の樹脂積層体。
［１２］熱可塑性樹脂層（Ｂ）及び（Ｃ）に含まれる（メタ）アクリル樹脂の重量平均分子量が５０,０００〜３００,０００である、前記［１１］に記載の樹脂積層体。
［１３］前記［１］〜［１２］のいずれかに記載の樹脂積層体を含む表示装置。
［１４］前記［１］〜［１２］のいずれかに記載の樹脂積層体及び偏光板が積層された樹脂積層体付き偏光板。
［１５］前記［１４］に記載の樹脂積層体付き偏光板を含む表示装置。 That is, the present invention includes the following preferred embodiments.
[1] A resin laminate having at least an intermediate layer (A) and thermoplastic resin layers (B) and (C) respectively present on both sides of the intermediate layer (A),
The intermediate layer (A) contains 10 to 90% by mass of (meth) acrylic resin and 90 to 10% by mass of vinylidene fluoride resin based on the total amount of resin contained in the intermediate layer (A); The weight average molecular weight (Mw) of the (meth) acrylic resin is 100,000 to 300,000,
The thermoplastic resin layers (B) and (C) have the following relationship:

[In the formula,
L _B and L _C respectively represent the average value of the film thickness of the thermoplastic resin layers (B) and (C),
Δλ _B is the following formula:

Represented by
Δλ _C has the following formula:

Represented by
λ ′ _B and λ ′ _C represent birefringence (I) measured for the thermoplastic resin layers (B) and (C) in the resin laminate, respectively
λ _B and λ _C are the thermoplastic resin layers (B) and (B) in the resin laminate after annealing for 4 hours at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) Represents the birefringence (II) measured for C),
T _B and _{T C,} respectively, represent a Vicat softening temperature of the thermoplastic resin layer (B) and (C). ]
Meet the resin laminate.
[2] The intermediate layer (A) contains 35 to 45% by mass of (meth) acrylic resin and 65 to 55% by mass of vinylidene fluoride resin based on the total amount of resin contained in the intermediate layer (A). The resin laminated body as described in said [1].
[3] The resin laminate according to the above [1] or [2], wherein the content of the alkali metal in the intermediate layer (A) is 50 ppm or less based on the total resin contained in the intermediate layer (A).
[4] (Meth) acrylic resin is
Structural units derived from 50 to 99.9% by mass of methyl methacrylate based on all the structural units constituting (a1) methyl methacrylate homopolymer and / or (a2) polymer, and 0.1 Formula (1) of ̃50% by mass:

[Wherein, R ₁ represents a hydrogen atom or a methyl group, and when R ₁ is a hydrogen atom, R ₂ represents an alkyl group having 1 to 8 carbon atoms, and when R ₁ is a methyl group, R ₂ has 2 to 2 carbon atoms] 8 represents an alkyl group. ]
The resin laminated body in any one of said [1]-[3] which is a copolymer containing the at least 1 structural unit derived from the (meth) acrylic acid ester shown by these.
[5] The resin laminate according to any one of the above [1] to [4], wherein the vinylidene fluoride resin is polyvinylidene fluoride.
[6] The melt mass flow rate of the vinylidene fluoride resin according to any one of the above [1] to [5], which is 0.1 to 40 g / 10 min as measured at 230 ° C. under a load of 3.8 kg. Resin laminate.
[7] The above [1] to [6], wherein the average value of the film thickness of the resin laminate is 100 to 2000 μm, and the average value of the film thicknesses of the thermoplastic resin layers (B) and (C) is 10 to 200 μm. ] The resin laminated body in any one of.
[8] The resin laminate according to any one of the above [1] to [7], wherein the Vicat softening temperature of the thermoplastic resin contained in the thermoplastic resin layers (B) and (C) is 100 to 160 ° C., respectively. .
[9] The resin laminate according to any one of the above [1] to [8], wherein the thermoplastic resin layers (B) and (C) are a (meth) acrylic resin layer or a polycarbonate resin layer.
[10] The thermoplastic resin layers (B) and (C) are polycarbonate resin layers and contain 0.005 to 2.0% by mass of an ultraviolet absorber based on the total resin contained in the respective thermoplastic resin layers The resin laminated body in any one of said [1]-[9].
[11] The thermoplastic resin layers (B) and (C) contain 50% by mass or more of (meth) acrylic resin based on the total resin contained in the respective thermoplastic resin layers, [1] to [9] ] The resin laminated body in any one of.
[12] The resin laminate according to the above [11], wherein the weight average molecular weight of the (meth) acrylic resin contained in the thermoplastic resin layers (B) and (C) is 50,000 to 300,000.
[13] A display device including the resin laminate according to any one of the above [1] to [12].
[14] A polarizing plate with a resin laminate, wherein the resin laminate and the polarizing plate according to any one of the above [1] to [12] are laminated.
[15] A display including the polarizing plate with a resin laminate according to [14].

  The resin laminate of the present invention is hardly warped even when used under an environment of high temperature and high humidity, for example, and is suitably used in a display device and the like.

It is the schematic of the manufacturing apparatus of the resin laminated body of this invention used for the Example. It is a cross-sectional schematic diagram which shows one preferable form of the liquid crystal display containing the resin laminated body of this invention.

  The resin laminate of the present invention has at least an intermediate layer (A) and thermoplastic resin layers (B) and (C) respectively present on both sides of the intermediate layer (A). In other words, the resin laminate of the present invention at least has a configuration in which the thermoplastic resin layer (B) / the intermediate layer (A) / the thermoplastic resin layer (C) is laminated in this order.

  The intermediate layer (A) contains 10 to 90% by mass of (meth) acrylic resin and 90 to 10% by mass of vinylidene fluoride resin based on the total resin contained in the intermediate layer (A). When the amount of (meth) acrylic resin is lower than the above lower limit, sufficient transparency can not be obtained, and when the amount of (meth) acrylic resin is higher than the above upper limit, a sufficient dielectric constant can not be obtained. When the amount of vinylidene fluoride resin is lower than the above lower limit, a sufficient dielectric constant can not be obtained, and when the amount of vinylidene fluoride resin is higher than the above upper limit, durability and sufficient transparency can not be obtained.

  The intermediate layer (A) is a 30 to 60% by mass (meth) acrylic resin based on the total resin contained in the intermediate layer (A) from the viewpoint of easily increasing the dielectric constant and enhancing the transparency of the resin laminate. And 70 to 40% by mass of a vinylidene fluoride resin, and more preferably 35 to 45% by mass of a (meth) acrylic resin and 65 to 55% by mass of a vinylidene fluoride resin, It is even more preferable to include 60% (meth) acrylic resin and 63 to 55% by mass vinylidene fluoride resin, and includes 38 to 45% by mass (meth) acrylic resin and 62 to 55% by mass vinylidene fluoride resin Particularly preferred is 38 to 43% by weight of (meth) acrylic resin and 62 to 57% by weight of vinylidene fluoride resin.

  As a (meth) acrylic resin contained in the intermediate layer (A) of the resin laminate of the present invention, for example, homopolymers of (meth) acrylic monomers such as (meth) acrylic acid ester and (meth) acrylonitrile, 2 types The copolymer of the above (meth) acryl monomer, the copolymer of the (meth) acryl monomer and monomers other than the (meth) acryl monomer, etc. are mentioned. In addition, in this specification, the term "(meth) acryl" means "acryl" or "methacryl."

  The (meth) acrylic resin is preferably a methacrylic resin from the viewpoint of easily enhancing the hardness, the weather resistance and the transparency of the resin laminate. The methacrylic resin is a polymer of monomers mainly composed of methacrylic acid ester (alkyl methacrylate), and, for example, a homopolymer of methacrylic acid ester (polyalkyl methacrylate) and a co-weight of two or more kinds of methacrylic acid ester Examples thereof include copolymers and copolymers of 50% by mass or more of methacrylic acid ester and 50% by mass or less of monomers other than methacrylic acid ester. As a copolymer of methacrylic acid ester and a monomer other than methacrylic acid ester, 70% by mass or more of methacrylic acid ester and 30% by mass with respect to the total amount of monomers from the viewpoint of easily improving optical characteristics and weatherability. Copolymers with other monomers by mass or less are preferable, and copolymers with 90% by mass or more of methacrylic acid esters and 10% by mass or less of other monomers are more preferable.

  Examples of monomers other than methacrylic acid esters include acrylic acid esters and monofunctional monomers having one polymerizable carbon-carbon double bond in the molecule.

  Examples of monofunctional monomers include styrene monomers such as styrene, α-methylstyrene and vinyl toluene; alkenyl cyanides such as acrylonitrile and methacrylonitrile; acrylic acid; methacrylic acid; maleic anhydride; N-substituted Maleimide; and the like.

  From the viewpoint of heat resistance, the (meth) acrylic resin may be copolymerized with N-substituted maleimide such as phenyl maleimide, cyclohexyl maleimide and methyl maleimide, or in the molecular chain (in the main skeleton of the polymer or A lactone ring structure, a glutaric anhydride structure, a glutarimide structure or the like may be introduced into the main chain).

［式中、Ｒ_１は水素原子又はメチル基を表し、Ｒ_１が水素原子のときＲ_２は炭素数１〜８のアルキル基を表し、Ｒ_１がメチル基のときＲ_２は炭素数２〜８のアルキル基を表す。］
で示される（メタ）アクリル酸エステルに由来する少なくとも１つの構造単位を含む共重合体
であることが好ましい。ここで、各構造単位の含有量は、得られた重合体を熱分解ガスクロマトグラフィーにより分析し、各単量体に対応するピーク面積を測定することにより算出できる。 Specifically, from the viewpoint of easily increasing the hardness, weather resistance, and transparency of a resin laminate (meth) acrylic resin,
50 to 99.9% by mass, preferably 70.0 to 99.8% by mass, based on all structural units constituting (a1) methyl methacrylate homopolymer and / or (a2) copolymer Preferably, structural units derived from 80.0 to 99.7% by mass of methyl methacrylate, and 0.1 to 50% by mass, preferably 0.2 to 30% by mass, more preferably 0.3 to 20% by mass % Equation (1):

[Wherein, R ₁ represents a hydrogen atom or a methyl group, and when R ₁ is a hydrogen atom, R ₂ represents an alkyl group having 1 to 8 carbon atoms, and when R ₁ is a methyl group, R ₂ has 2 to 2 carbon atoms] 8 represents an alkyl group. ]
It is preferable that it is a copolymer including at least one structural unit derived from the (meth) acrylic acid ester represented by Here, the content of each structural unit can be calculated by analyzing the obtained polymer by pyrolysis gas chromatography and measuring the peak area corresponding to each monomer.

In formula (1), R ₁ represents a hydrogen atom or a methyl group, and when R ₁ is a hydrogen atom, R ₂ represents an alkyl group having 1 to 8 carbon atoms, and when R ₁ is a methyl group, R ₂ represents a carbon number 2-8 alkyl groups are represented. Examples of the alkyl group having 2 to 8 carbon atoms include ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group and octyl group. From the viewpoint of heat resistance, R ₂ is preferably an alkyl group having 2 to 4 carbon atoms, and more preferably an ethyl group.

  The weight average molecular weight (hereinafter sometimes referred to as Mw) of the (meth) acrylic resin contained in the intermediate layer (A) is 100,000 to 300,000. If Mw is lower than the above lower limit, the transparency when exposed to a high temperature and high humidity environment is not sufficient, and if Mw is higher than the above upper limit, film formability can not be obtained when producing a resin laminate. . The Mw of the (meth) acrylic resin is preferably 120,000 or more, more preferably 150,000 or more, from the viewpoint of easily enhancing the transparency when exposed to a high temperature and high humidity environment. The Mw of the (meth) acrylic resin is preferably 250,000 or less, and more preferably 200,000 or less, from the viewpoint of film formability when producing a resin laminate. The weight average molecular weight is measured by gel permeation chromatography (GPC) measurement.

  The (meth) acrylic resin is usually 0.1 to 20 g / 10 min, preferably 0.2 to 5 g / 10 min, more preferably 0.5 to 3 g / 10, as measured at a load of 3.8 kg and 230 ° C. It has the melt mass flow rate (it may be described as MFR hereafter) of a minute. The MFR is preferably equal to or less than the above upper limit because the strength of the resulting film can be easily increased, and the MFR is preferably equal to or more than the above lower limit from the viewpoint of the film formability of the resin laminate. MFR can be measured in accordance with the method defined in JIS K 7210: 1999 “Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastics”. With regard to poly (methyl methacrylate) -based materials, it is defined in this JIS that the measurement is performed at a temperature of 230 ° C. and a load of 3.80 kg (37.3 N).

  From the viewpoint of heat resistance, the (meth) acrylic resin preferably has a Vicat softening temperature (hereinafter sometimes referred to as VST) of 90 ° C. or more, more preferably 100 ° C. or more, and still more preferably 102 ° C. or more. . The upper limit of VST is not particularly limited, but is usually 150 ° C. or less. VST conforms to JIS K 7206: 1999 and can be measured by the B50 method described therein. VST can be adjusted to the above-mentioned range by adjusting the kind of monomer and its ratio.

  The (meth) acrylic resin can be prepared by polymerizing the above-mentioned monomers by known methods such as suspension polymerization and bulk polymerization. At that time, MFR, Mw, VST and the like can be adjusted to a preferable range by adding an appropriate chain transfer agent. A chain transfer agent can use an appropriate commercial item. The addition amount of the chain transfer agent may be appropriately determined in accordance with the kind of the monomer, the ratio thereof, the characteristics to be obtained, and the like.

  As a vinylidene fluoride resin contained in the intermediate | middle layer (A) of the resin laminated body of this invention, the homopolymer of vinylidene fluoride and the copolymer of vinylidene fluoride and another monomer are mentioned. The vinylidene fluoride resin is selected from the group consisting of trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, perfluoroalkylvinylether and ethylene from the viewpoint of easily increasing the transparency of the resin laminate obtained. It is preferably a copolymer of at least one monomer and vinylidene fluoride and / or a homopolymer of vinylidene fluoride (polyvinylidene fluoride), and more preferably polyvinylidene fluoride.

  The weight average molecular weight (Mw) of the vinylidene fluoride resin contained in the intermediate layer (A) is preferably 100,000 to 500,000, more preferably 150,000 to 450,000, and still more preferably 200,000 to 450,000, particularly preferably 350,000 to 450,000. When the resin laminate of the present invention is exposed to the high temperature and high humidity environment (for example, 60 ° C., relative humidity 90%) that Mw is not less than the above lower limit, the transparency of the resin laminate can be easily improved. preferable. Moreover, it is preferable that Mw is below the said upper limit in order to be easy to improve the film-formability of a resin laminated body. The weight average molecular weight is measured by gel permeation chromatography (GPC) measurement.

  The vinylidene fluoride resin is preferably 0.1 to 40 g / 10 min, more preferably 0.1 to 30 g / 10 min, still more preferably 0.1 to 25 g, as measured at a load of 3.8 kg and 230 ° C. It has a melt mass flow rate (MFR) of 10 minutes. The MFR is more preferably 0.2 g / 10 min or more, still more preferably 0.5 g / 10 min or more. Further, the MFR is more preferably 20 g / 10 min or less, still more preferably 5 g / 10 min or less, and particularly preferably 2 g / 10 min or less. It is preferable that the MFR be equal to or less than the above-described upper limit because it is easy to suppress the decrease in transparency when the resin laminate is used for a long time. It is preferable that the MFR is equal to or more than the above lower limit because the film formability of the resin laminate can be easily enhanced. MFR can be measured in accordance with the method defined in JIS K 7210: 1999 “Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastics”.

  The vinylidene fluoride resin is industrially produced by a suspension polymerization method or an emulsion polymerization method. The suspension polymerization method is carried out by using water as a medium, dispersing the monomer as droplets in the medium with a dispersant, and polymerizing an organic peroxide dissolved in the monomer as a polymerization initiator. A granular polymer of 100 to 300 μm is obtained. Suspension polymerization is preferable because it has a simple manufacturing process as compared with emulsion polymerization, is excellent in powder handling properties, and does not contain an emulsifier or a salting agent containing an alkali metal as in emulsion polymerization.

  Commercially available vinylidene fluoride resins may be used. As an example of a preferable commercial item, "KF polymer (registered trademark) T # 1300, T # 1100, T # 1000, T # 850, W # 850, W # 1000, W # 1100 and W # 1300" of Kureha Co., Ltd. , "SOLEF (R) 6012, 6010 and 6008" manufactured by Solvay.

  The mid layer (A) may further contain other resins different from (meth) acrylic resin and vinylidene fluoride resin. When other resins are contained, the type is not particularly limited as long as the transparency of the resin laminate is not significantly impaired. From the viewpoint of the hardness and weather resistance of the resin laminate, the amount of the other resin is preferably 15% by mass or less, and 10% by mass or less based on the total resin contained in the intermediate layer (A). Is more preferable, and 5% by mass or less is even more preferable. Other resins include, for example, polycarbonate resins, polyamide resins, acrylonitrile-styrene copolymers, methyl methacrylate-styrene copolymers, polyethylene terephthalate and the like. The intermediate layer (A) may further contain another resin, but from the viewpoint of transparency, the amount of the other resin is preferably 1% by mass or less, and the resin contained in the intermediate layer (A) It is more preferable that it is only a (meth) acrylic resin and vinylidene fluoride resin.

  The content of the alkali metal in the intermediate layer (A) is preferably 50 ppm or less, more preferably 30 ppm or less, still more preferably 10 ppm or less, particularly preferably 1 ppm or less, based on the total resin contained in the intermediate layer (A) It is. It is preferable that the content of the alkali metal in the intermediate layer (A) is not more than the above-described upper limit, because it is easy to suppress the decrease in transparency when the resin laminate is used in a high temperature and high humidity environment for a long time. The lower limit value of the content of the alkali metal in the intermediate layer (A) is 0, and from the viewpoint of easily suppressing the decrease in transparency of the resin laminate, it is extremely preferable that the resin be substantially not contained. Here, in the (meth) acrylic resin and / or the vinylidene fluoride resin contained in the intermediate layer (A), a small amount of an emulsifier or the like used in the manufacturing process remains. Therefore, the intermediate layer (A) contains, for example, 0.05 ppm or more of an alkali metal such as sodium or potassium derived from the remaining emulsifier. In particular, when the (meth) acrylic resin and / or the vinylidene fluoride resin contained in the intermediate layer (A) is obtained by emulsion polymerization, the amount of the emulsifier remaining in the resin increases, and in the intermediate layer (A) The alkali metal content also increases. From the viewpoint of easily suppressing the decrease in transparency of the resin laminate, it is preferable to use a resin having a small content of alkali metal as the (meth) acrylic resin and the vinylidene fluoride resin contained in the intermediate layer (A) .

  In order to make the content of the alkali metal in the resin fall within the above range, the amount of the compound containing the alkali metal in the polymerization of the resin is reduced or the number of washing steps after the polymerization is increased to make the compound containing the alkali metal It should be removed. The content of the alkali metal can be determined, for example, by inductively coupled plasma mass spectrometry (ICP / MS). As inductively coupled plasma mass spectrometry, for example, high temperature ashing melting method, high temperature ashing acid dissolution method, Ca addition ashing acid dissolution method, combustion absorption method, low temperature ashing acid dissolution method etc. The sample may be incinerated by an appropriate method, dissolved in an acid, and the volume of this solution may be adjusted to measure the content of the alkali metal by inductively coupled plasma mass spectrometry.

  The resin laminate of the present invention has at least thermoplastic resin layers (B) and (C) present on both sides of the intermediate layer (A). The thermoplastic resin layer (B) and the thermoplastic resin layer (C) may be the same layer or may be layers different from each other.

  The thermoplastic resin layers (B) and (C) contain at least one thermoplastic resin. The thermoplastic resin layers (B) and (C) are preferably 60% by mass or more, more preferably 70% by mass, based on the total resin contained in each thermoplastic resin layer, from the viewpoint of easily enhancing the molding processability. The above, more preferably 80% by mass or more of the thermoplastic resin is contained. The upper limit of the amount of thermoplastic resin is 100% by mass. As a thermoplastic resin, (meth) acrylic resin, polycarbonate resin, cycloolefin resin etc. are mentioned. The thermoplastic resin is preferably a (meth) acrylic resin or a polycarbonate resin from the viewpoint of easily enhancing the adhesion between the thermoplastic resin layers (B) and (C) and the intermediate layer (A). The thermoplastic resin layers (B) and (C) may contain the same thermoplastic resin or may contain different thermoplastic resins. It is preferable that the thermoplastic resin layers (B) and (C) contain the same thermoplastic resin from the viewpoint of easily suppressing the warpage of the resin laminate.

  The thermoplastic resin contained in the thermoplastic resin layers (B) and (C) is preferably measured at 100 to 160 ° C., as measured in accordance with JIS K 7206: 1999, from the viewpoint of the heat resistance of the resin laminate. It has a Vicat softening temperature which is preferably 102-155.degree. C., even more preferably 102-152.degree. Here, when the thermoplastic resin layer contains one type of thermoplastic resin, the above Vicat softening temperature is the Vicat softening temperature of the resin, and when the thermoplastic resin layer contains two or more types of thermoplastic resin. Is the Vicat softening temperature of a mixture of thermoplastic resins.

  The thermoplastic resin layers (B) and (C) are for the purpose of enhancing the strength, elasticity and the like of the thermoplastic resin layer, and further resins other than the thermoplastic resin (for example, thermosetting resins such as filler and resin particles) May be included. In this case, the amount of the other resin is preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, based on the total resin contained in each thermoplastic resin layer. . The lower limit of the amount of other resins is 0% by mass.

［式中、Ｌ_Ｂ及びＬ_Ｃは、それぞれ、熱可塑性樹脂層（Ｂ）及び（Ｃ）の膜厚の平均値を表す。］
を満たす。 In the resin laminate of the present invention, the thermoplastic resin layers (B) and (C) have the following relationship:

[Wherein, L _B and L _C represent the average value of the film thickness of the thermoplastic resin layers (B) and (C), respectively. ]
Meet.

  From the viewpoint of easily suppressing the warpage of the resin laminate of the present invention, ΔL is preferably 17 μm or less, and more preferably 15 μm or less. ΔL means the difference between the average values of the film thicknesses of the thermoplastic resin layers (B) and (C), and by adjusting the film thicknesses of the thermoplastic resin layers (B) and (C), the ΔL can be expressed as It can be in the range. Here, the film thickness of the thermoplastic resin layer is measured using a microscope (for example, a microscope manufactured by Microsquare Co., Ltd.). The average value of the values obtained by performing the above measurement at any 10 points of the thermoplastic resin layer is taken as the average value of the film thickness. Since ΔL is an absolute value, its lower limit is 0 μm.

［式中、
Δλ_Ｂは次の式：

で表され、
Δλ_Ｃは次の式：

で表され、
λ’_Ｂ及びλ’_Ｃは、それぞれ、樹脂積層体における熱可塑性樹脂層（Ｂ）及び（Ｃ）について測定した複屈折（Ｉ）を表し、
λ_Ｂ及びλ_Ｃは、それぞれ、熱可塑性樹脂層（Ｂ）及び（Ｃ）のビカット軟化温度より２５℃低い温度で４時間のアニール処理後の樹脂積層体における熱可塑性樹脂層（Ｂ）及び（Ｃ）について測定した複屈折（ＩＩ）を表す。］
を満たす。 In the resin laminate of the present invention, the thermoplastic resin layers (B) and (C) further have the following relationship:

[In the formula,
Δλ _B is the following formula:

Represented by
Δλ _C has the following formula:

Represented by
λ ′ _B and λ ′ _C represent birefringence (I) measured for the thermoplastic resin layers (B) and (C) in the resin laminate, respectively
λ _B and λ _C are the thermoplastic resin layers (B) and (B) in the resin laminate after annealing for 4 hours at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) The birefringence (II) measured for C) is expressed. ]
Meet.

［式中、λは複屈折を表し、Ｒは波長５９０ｎｍにおける位相差を表し、Ｌは位相差測定用試料の短辺の長さ（ｎｍ）を表す。］
により算出される複屈折（λ）である。 With respect to λ ′ _B and λ ′ _C in the present specification, the birefringence (I) measured for the thermoplastic resin layers (B) and (C) in the resin laminate is the thermoplastic resin layer (B) in the resin laminate or The phase difference (R) at a wavelength of 590 nm of (C) is measured using an automatic birefringence meter (for example, “KOBRA-CCD” manufactured by Oji Scientific Co., Ltd.), and from the obtained phase difference, the following formula:

[Wherein, λ represents birefringence, R represents a retardation at a wavelength of 590 nm, and L represents the length (nm) of the short side of the retardation measurement sample. ]
Is the birefringence (λ) calculated by

［式中、λは複屈折を表し、Ｒは波長５９０ｎｍにおける位相差を表し、Ｌは位相差測定用試料の短辺の長さ（ｎｍ）を表す。］
により算出される複屈折（λ）である。なお、上記アニール処理は、樹脂積層体を、熱可塑性樹脂層（Ｂ）及び（Ｃ）のビカット軟化温度より２５℃低い温度で４時間放置する処理であり、熱可塑性樹脂層（Ｂ）及び（Ｃ）のビカット軟化温度が互いに異なる場合には、高い方のビカット軟化温度より２５℃低い温度でアニール処理を行う。 The thermoplastic resin layer (B) in the resin laminate after annealing for 4 hours at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) with respect to λ _B and λ _C in the present specification The birefringence (II) measured for (C) and (C) is an automatic birefringence meter for the retardation (R) of the thermoplastic resin layer (B) or (C) at a wavelength of 590 nm using the resin laminate after annealing treatment (For example, "KOBRA-CCD" manufactured by Oji Scientific Co., Ltd.) The following equation is obtained from the obtained phase difference:

[Wherein, λ represents birefringence, R represents a retardation at a wavelength of 590 nm, and L represents the length (nm) of the short side of the retardation measurement sample. ]
Is the birefringence (λ) calculated by The above-mentioned annealing treatment is a treatment in which the resin laminate is left to stand at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) for 4 hours. When the Vicat softening temperatures of C) are different from each other, the annealing treatment is performed at a temperature 25 ° C. lower than the higher Vicat softening temperature.

In one aspect of the present invention in which the thermoplastic resin layers (B) and (C) are (meth) acrylic resin layers, Δλ _B and Δλ _C are each from the viewpoint of easily suppressing the warpage of the resin laminate of the present invention is preferably 0.16 × ^{10 -4} or less, more preferably 0.15 × ^{10 -4} or less. In another aspect of the present invention in which the thermoplastic resin layers (B) and (C) are polycarbonate resin layers, Δλ _B and Δλ _C are each 0.61 × 10 ⁻⁴ or less from the same viewpoint. Is preferable, and 0.60 × 10 ⁻⁴ or less is more preferable. Δλ _B and Δλ _C are the thermoplastic resin layer (B) by subjecting the birefringence (I) of the thermoplastic resin layers (B) and (C) in the resin laminate and the resin laminate to the above-mentioned annealing treatment, respectively (C) and (C) mean the difference between the birefringence (II) of the thermoplastic resin layers (B) and (C) measured after removing the intrinsic intrinsic birefringence generated during molding. The fact that this difference is large indicates that the distortion of the polymer arrangement of the resin that occurs when molding each layer is large. Δλ _B and Δλ _C can be brought into the above ranges by adjusting the cooling rate at the time of production of the resin laminate. In addition, since Δλ _B and Δλ _C are absolute values, the lower limit value is 0.

It is preferable that (DELTA) (lambda) _BC is 0.18 * 10 <^-4> or less from a viewpoint which is easy to suppress curvature of the resin laminated body of this invention. Δλ _BC is calculated by subtracting the difference between birefringence (II) and birefringence (I) in thermoplastic resin layer (C) from the difference between birefringence (II) and birefringence (I) in thermoplastic resin layer (B) The fact that the absolute value is large and this value is large indicates that the difference in the degree of strain generated during molding is large between the thermoplastic resin layer (B) and the thermoplastic resin layer (C). Δλ _BC can be in the above range by adjusting the type and amount of the resin contained in the thermoplastic resin layers (B) and (C), and the cooling rate. Since Δλ _BC is an absolute value, its lower limit is zero.

  Using the resin laminate of the present invention under conditions such as high temperature and high humidity that the resin laminate has the thermoplastic resin layers (B) and (C) in which the strain of the polymer arrangement is within a specific range Is also considered to be a factor that hardly causes warpage.

［式中、Ｔ_Ｂ及びＴ_Ｃは、それぞれ、熱可塑性樹脂層（Ｂ）及び（Ｃ）のビカット軟化温度を表す。］
を満たす。 In the resin laminate of the present invention, the thermoplastic resin layers (B) and (C) further have the following relationship:

Wherein, _{T B} and _{T C,} respectively, represent a Vicat softening temperature of the thermoplastic resin layer (B) and (C). ]
Meet.

  ΔT is preferably 3 ° C. or less, more preferably 2 ° C. or less, still more preferably 1 ° C. or less, from the viewpoint of easily suppressing the warpage of the resin laminate of the present invention, 0 ° C. It is highly preferred that ΔT means the difference between the Vicat softening temperatures of the thermoplastic resin layers (B) and (C), and a large difference indicates that the difference in strain relaxation rate is large. ΔT can be made within the above range by adjusting the type and composition of the resin contained in the thermoplastic resin layers (B) and (C). Here, the Vicat softening temperature of the thermoplastic resin layer is measured according to JIS K 7206: 1999 "plastic-thermoplastic-Vicat softening temperature (VST) test method" according to the B50 method defined. The Vicat softening temperature can be measured using a heat distortion tester (for example, “148-6 continuous mold” manufactured by Yasuda Seiki Co., Ltd.). The measurement may be performed using a test piece obtained by pressing each raw material to a thickness of 3 mm. Here, since ΔT is an absolute value, the lower limit value thereof is zero.

  The thermoplastic resin layers (B) and (C) are preferably a (meth) acrylic resin layer or a polycarbonate resin layer, from the viewpoint of good moldability and easy adhesion to the intermediate layer (A). .

  One embodiment of the present invention in which the thermoplastic resin layers (B) and (C) are (meth) acrylic resin layers will be described below. In this aspect, the thermoplastic resin layers (B) and (C) contain one or more (meth) acrylic resins. The thermoplastic resin layers (B) and (C) are preferably 50% by mass or more, more preferably 60% by mass or more, further preferably from the viewpoint of surface hardness, based on the total resin contained in each thermoplastic resin layer. Preferably, 70% by mass or more of (meth) acrylic resin is contained.

  As a (meth) acrylic resin, the resin described about the (meth) acrylic resin contained in an intermediate | middle layer (A) is mentioned. The preferred (meth) acrylic resin described for the intermediate layer (A) is likewise preferred as the (meth) acrylic resin contained in the thermoplastic resin layers (B) and (C) unless otherwise specified. The (meth) acrylic resin contained in the thermoplastic resin layers (B) and (C) and the (meth) acrylic resin contained in the intermediate layer (A) may be the same or different.

  The weight average molecular weight (Mw) of the (meth) acrylic resin is preferably 50,000 to 300,000, more preferably 70,000 to 250, from the viewpoint of good molding processability and easy enhancement of mechanical strength. , 000. The weight average molecular weight is measured by gel permeation chromatography (GPC) measurement.

  In this aspect, the thermoplastic resin layers (B) and (C) may further contain a thermoplastic resin other than one or more (meth) acrylic resins. As a thermoplastic resin other than (meth) acrylic resin, a thermoplastic resin compatible with (meth) acrylic resin is preferable. Specifically, methyl methacrylate-styrene-maleic anhydride copolymer (for example, "Rescify" manufactured by Denki Kagaku Kogyo Co., Ltd.), methyl methacrylate-methacrylic acid copolymer (for example, "Altograss HT121" manufactured by Arkema), polycarbonate resin Can be mentioned. From the viewpoint of heat resistance, the thermoplastic resin other than the (meth) acrylic resin is preferably measured at 115 ° C. or higher, more preferably 117 ° C. or higher, still more preferably 120 ° C. or higher, as measured according to JIS K 7206: 1999. It is preferable to have a Vicat softening temperature of From the viewpoint of heat resistance and surface hardness, the thermoplastic resin layers (B) and (C) preferably do not substantially contain a vinylidene fluoride resin.

  In this aspect, the pencil hardness of the thermoplastic resin layers (B) and (C) is preferably HB or more, more preferably F or more, and H or more from the viewpoint of enhancing scratch resistance. Is even more preferred.

  Next, another embodiment of the present invention in which the thermoplastic resin layers (B) and (C) are polycarbonate resin layers will be described below. In this aspect, the thermoplastic resin layers (B) and (C) comprise one or more polycarbonate resins. The thermoplastic resin layers (B) and (C) are preferably 60% by mass or more, more preferably 70% by mass or more, further preferably from the viewpoint of impact resistance, based on the total resin contained in each thermoplastic resin layer. More preferably, 80 mass% or more polycarbonate resin is included.

  Examples of polycarbonate resins include polymers obtained by the phosgene method in which various dihydroxy diaryl compounds and phosgene are reacted, or the transesterification method in which dihydroxy diaryl compounds and carbonic esters such as diphenyl carbonate are reacted, In particular, polycarbonate resins produced from 2,2-bis (4-hydroxyphenyl) propane (generally called bisphenol A) can be mentioned.

  As the above dihydroxy diaryl compounds, in addition to bisphenol A, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- Bis (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxydiaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyl diphenyl sulfoxide, dihydroxy diaryl such as 4,4'-dihydroxy diphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfone Sulfone, and the like.

  These may be used alone or in combination of two or more, but in addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl and the like may be mixed and used.

  Furthermore, the above-mentioned dihydroxy aryl compounds and trivalent or higher phenol compounds as shown below may be used in combination. Examples of phenol having 3 or more valence include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4,6 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  As polycarbonate resins other than the said polycarbonate resin, the polycarbonate synthesize | combined from isosorbite and aromatic diol is mentioned. As an example of the polycarbonate, "DURABIO (registered trademark)" manufactured by Mitsubishi Chemical Corporation can be mentioned.

  A commercially available product may be used as the polycarbonate resin. For example, “Karibar (registered trademark) 301-4, 301-10, 301-15, 301-22, 301-30, 301-40 manufactured by Sumika Styron Polycarbonate Co., Ltd. , SD 2221 W, SD 2201 W, TR 2201 "and the like.

  In this embodiment, the weight average molecular weight (Mw) of the polycarbonate resin is preferably 20,000 to 70,000, and more preferably 25,000 to 60,000, from the viewpoint of easily enhancing the impact resistance and the molding processability. It is. The weight average molecular weight is measured by gel permeation chromatography (GPC) measurement.

In this embodiment, the polycarbonate resin contained in the thermoplastic resin layers (B) and (C) is preferably ³ to 120 cm 3/10 minutes, more preferably, as measured under conditions of a temperature of 300 ° C. and a load of 1.2 kg. 3~80cm ^3/10 min, even more preferably 4~40cm ^3/10 min, particularly preferably 10 to 40 cm ^3/10 min melt volume rate (hereinafter, also referred to as MVR.) having a. When the MVR is higher than the above lower limit, it is preferable because the fluidity is sufficiently high, it is easy to form and process in melt coextrusion molding and the like, and appearance defects are unlikely to occur. When MVR is lower than the above upper limit, mechanical properties such as strength of the polycarbonate resin layer can be easily enhanced, which is preferable. MVR can be measured at 300 ° C. under a load of 1.2 kg in accordance with JIS K 7210.

  In this aspect, the thermoplastic resin layers (B) and (C) may further contain a thermoplastic resin other than one or more polycarbonate resins. As thermoplastic resins other than polycarbonate resin, thermoplastic resin compatible with polycarbonate resin is preferable, (meth) acrylic resin is more preferable, and methacrylic resin which has an aromatic ring or a cycloolefin in a structure is still more preferable. When the thermoplastic resin layers (B) and (C) contain the polycarbonate resin and the above (meth) acrylic resin, the surface hardness of the thermoplastic resin layers (B) and (C) is only the polycarbonate resin It is preferable because it can be made higher as compared with.

  In the resin laminate of the present invention, at least one of the intermediate layer (A) and the thermoplastic resin layers (B) and (C), various additives generally used within a range not inhibiting the effects of the present invention May be further included. As the additive, for example, a stabilizer, an antioxidant, an ultraviolet light absorber, a light stabilizer, a foaming agent, a lubricant, a release agent, an antistatic agent, a flame retardant, a release agent, a polymerization inhibitor, a flame retardant auxiliary And colorants such as reinforcing agents, nucleating agents and bluing agents.

  As a coloring agent, the compound which has an anthraquinone frame | skeleton, the compound which has phthalocyanine frame | skeleton, etc. can be mentioned. Among these, a compound having an anthraquinone skeleton is preferable from the viewpoint of heat resistance.

  When at least one layer of the intermediate layer (A), the thermoplastic resin layers (B) and (C) further contains a colorant, the content of the colorant in each layer is appropriately determined according to the purpose, the type of the colorant, etc. It can be selected. When a bluing agent is used as the colorant, the content thereof can be about 0.01 to 10 ppm based on the total resin contained in each layer containing the bluing agent. This content is preferably 0.01 ppm or more, more preferably 0.05 ppm or more, still more preferably 0.1 ppm or more, and preferably 7 ppm or less, more preferably 5 ppm or less, still more preferably 4 ppm or less, Particularly preferably, it is 3 ppm or less. As the bluing agent, known ones can be appropriately used. For example, Macrorex (registered trademark) Blue RR (manufactured by Bayer) and Macrolex (registered trademark) Blue 3R (manufactured by Bayer) under the trade names, respectively Examples include Sumiplast (registered trademark) Viloet B (manufactured by Sumika Chemtex Co., Ltd.), polycisren (registered trademark) blue RLS (manufactured by Clariant), Diaresin Violet D, Diaresin blue G, and Diaresin Blue N (all manufactured by Mitsubishi Chemical Corporation). Be

  The ultraviolet absorber is not particularly limited, and various conventionally known ultraviolet absorbers may be used. For example, the ultraviolet absorber which has an absorption maximum in 200-320 nm or 320-400 nm is mentioned. Specific examples thereof include triazine-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, and cyanoacrylate-based UV absorbers. As the ultraviolet absorber, one of these ultraviolet absorbers may be used alone, or two or more thereof may be used in combination. Using at least one UV absorber having an absorption maximum at 200 to 320 nm and at least one UV absorber having an absorption maximum at 320 to 400 nm can also more effectively prevent damage by UV light It is preferable from A commercially available product may be used as the ultraviolet light absorber, for example, “Kemisorb 102” (2,4-bis (2,4-dimethylphenyl) -6- (2-hydroxy-4-N-octyl) manufactured by Chemi-Pro Chemical Co., Ltd. Oxyphenyl) -1,3,5-triazine) (absorbance 0.1), "ADEKASTAB LA-F70" (2,4,6-tris (2-hydroxy-4-hexyloxy-3-methyl) manufactured by ADEKA CORPORATION Phenyl) -1,3,5-triazine) (absorbance: 0.6), “Adekastab LA-31, LA-31 RG, LA-31 G” (2,2′-methylenebis (4- (1,1,3,3) -Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol) (absorbance 0.2), "ADEKA STAB LA-46" (2- (4, 6 Diphenyl-1,3,5-triazin-2-yl) -5- (2- (2-ethylhexaneuroxy) ethoxy) phenol) (absorbance 0.05) or “tinuvin 1577” manufactured by BASF Japan Ltd. 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine) (absorbance 0.1), etc. The absorbance of the exemplified UV absorber is as measured at 380 nm. The absorbance can be measured by dissolving the ultraviolet absorber in chloroform at a concentration of 10 mg / L and using a spectrophotometer (e.g. a spectrophotometer U-4100 manufactured by HITACHI).

  When at least one layer of the intermediate layer (A), the thermoplastic resin layer (B) and (C) further contains an ultraviolet light absorber, the content of the ultraviolet light absorber in each layer depends on the purpose, type of ultraviolet light absorber, etc. It may be selected accordingly. For example, the content of the ultraviolet light absorber can be about 0.005 to 2.0% by mass based on the entire resin contained in each layer containing the ultraviolet light absorber. The content of the ultraviolet absorber is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and still more preferably 0.03% by mass or more. Further, the content of the ultraviolet absorber is preferably 1.5% by mass or less, more preferably 1.0% by mass or less. It is preferable that the content of the ultraviolet absorber is not less than the above lower limit from the viewpoint of easily enhancing the ultraviolet absorption effect, and being not more than the above upper limit prevents the change of the tint (for example, the yellowness YI) of the resin laminate. It is preferable because it is easy to do. For example, it is preferable to use the above-mentioned commercially available product "ADEKA Stub LA-31, LA-31 RG, LA-31 G" in the above amount.

  In another embodiment of the present invention, the thermoplastic resin layers (B) and (C) are polycarbonate resin layers, and 0.005 to 2.0% by mass based on the total resin contained in each thermoplastic resin layer It is preferable to contain the ultraviolet absorber of the above, because it is easy to obtain a resin laminate excellent in light resistance.

  In the resin laminate of the present invention, the average value of the film thickness of the resin laminate is 100 to 2000 μm, and the average value of the film thicknesses of the thermoplastic resin layers (B) and (C) is 10 to 200 μm. It is preferable from the viewpoint of easily suppressing the warpage of the resin laminate of the present invention.

  The average value of the film thickness of the resin laminate of the present invention is preferably 100 μm or more, more preferably 200 μm or more, and still more preferably 300 μm or more from the viewpoint of the rigidity of the resin laminate. Further, from the viewpoint of transparency, it is preferably 2000 μm or less, more preferably 1500 μm or less, and still more preferably 1000 μm or less. The film thickness of the resin laminate is measured by a digital micrometer. Let the average value which measured the said measurement in ten points of the resin laminated body be the average value of film thickness.

  In the resin laminate of the present invention, the average value of the film thicknesses of the thermoplastic resin layers (B) and (C) is preferably 10 μm or more, more preferably 30 μm or more, and still more preferably from the viewpoint of easily increasing the surface hardness. Preferably it is 50 micrometers or more. Also, from the viewpoint of the dielectric constant, it is preferably 200 μm or less, more preferably 175 μm or less, and still more preferably 150 μm or less. The method of measuring the average value of the film thickness of the thermoplastic resin layer is as described above.

  In the resin laminate of the present invention, the average film thickness of the intermediate layer (A) is preferably 100 μm or more, more preferably 200 μm or more, and still more preferably 300 μm or more from the viewpoint of dielectric constant. Also, from the viewpoint of transparency, it is preferably 1500 μm or less, more preferably 1200 μm or less, and still more preferably 1000 μm or less. The average value of the film thickness of the intermediate layer (A) can be measured by the same method as the measurement of the average value of the film thickness of the thermoplastic resin layer.

  The resin laminate of the present invention preferably has a dielectric constant of 3.5 or more, more preferably 4.0 or more, still more preferably 4.1 or more, from the viewpoint of obtaining a function sufficient for use in a display device such as a touch panel. Have a rate. The upper limit of the dielectric constant is not particularly limited, but is usually 20. The dielectric constant is adjusted by adjusting the type and amount of the vinylidene fluoride resin contained in the intermediate layer (A) of the resin laminate of the present invention, or adding a high dielectric constant compound such as ethylene carbonate or propylene carbonate. It can be adjusted to the range of According to JIS K 6911: 1995, the dielectric constant of the resin laminate of the present invention is allowed to stand for 24 hours in an environment of 50% relative humidity at 23 ° C., and under this environment, 3 V is obtained by the automatic equilibrium bridge method. , 100 kHz measured values. A commercially available instrument may be used for the measurement, for example, "precision LCR meter HP4284A" manufactured by Agilent Technologies, Inc. may be used.

  The resin laminate of the present invention is preferably transparent when observed by visual observation. Specifically, the resin laminate of the present invention preferably has a total light transmittance of 85% or more, more preferably 88% or more, and still more preferably 90% or more, as measured in accordance with JIS K 7361-1: 1997. Have a rate (Tt). The upper limit of the total light transmittance is 100%. It is preferred that the resin laminate after exposure for 120 hours in an environment of 60 ° C. and 90% relative humidity still have a total light transmittance in the above range.

  The resin laminate of the present invention is preferably 2.0% or less as measured according to JIS K 7136: 2000 using the resin laminate after exposure for 120 hours in an environment of 60 ° C. and 90% relative humidity. More preferably, it has a haze of 1.8% or less, still more preferably 1.5% or less. In addition, the resin laminate of the present invention is preferably 1.5 or less, as measured according to JIS Z 8722: 2009, using a resin laminate after exposure for 120 hours in an environment of 60 ° C. and 90% relative humidity. More preferably, it has a yellowness (Yellow Index: YI value) of 1.4 or less, still more preferably 1.3 or less. The resin laminate of the present invention having the above haze and yellowness is capable of maintaining transparency and suppressing yellowing, in addition to the fact that warping does not easily occur even when used under environments such as high temperature and high humidity. It is preferable from

  The resin laminate of the present invention may further have at least one functional layer in addition to the intermediate layer (A) and the thermoplastic resin layers (B) and (C). The functional layer is preferably present on the surface of the thermoplastic resin layer (B) and / or (C) opposite to the intermediate layer (A). Examples of the functional layer include a hard coat layer, an antireflective layer, an antiglare layer, an antistatic layer, and an anti-fingerprint layer. These functional layers may be laminated to the resin laminate of the present invention via an adhesive layer, or may be a coating layer laminated by coating. As a functional layer, you may use a cured film which is described, for example in Unexamined-Japanese-Patent No. 2013-86273. The functional layer is formed, for example, by a coating method, a sputtering method, a vacuum evaporation method or the like on at least one functional layer selected from the group consisting of a hard coat layer, an antiglare layer, an antistatic layer and an anti-fingerprint layer. The layer in which the anti-reflective layer is further coated may be sufficient, and the layer by which the anti-reflective sheet was bonded by one side or both surfaces of the said at least 1 functional layer may be sufficient.

  The thickness of the functional layer may be appropriately selected according to the purpose of each functional layer, but is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more from the viewpoint of easily expressing the function From the viewpoint of preventing cracking easily, it is preferably 100 μm or less, more preferably 80 μm or less, and still more preferably 70 μm or less.

  The resin laminate of the present invention is produced from a resin composition (A) giving an intermediate layer (A), and resin compositions (B) and (C) giving thermoplastic resin layers (B) and (C), respectively. Can. In the present specification, the resin compositions (B) and (C) only need to contain at least a resin giving the thermoplastic resin layers (B) and (C), and the resin and any optional additives etc. 2 It may be a composition containing more than one component, or it may be just one resin.

  The resin composition (A) is generally obtained by kneading a (meth) acrylic resin and a vinylidene fluoride resin. Kneading can be performed, for example, by a method including a step of melt-kneading at a temperature of 150 to 350 ° C. and a shear rate of 10 to 1000 / sec.

  The temperature at which the melt-kneading is performed is preferably 150 ° C. or higher because the resin can be sufficiently melted, and 350 ° C. or lower is preferable because thermal decomposition of the resin is easily suppressed. Furthermore, it is preferable that the shear rate at the time of performing the melt-kneading be 10 / second or more because the resin is easily kneaded sufficiently, and it is preferable that the shear rate be 1000 / second or less because the decomposition of the resin is easily suppressed.

  Melt-kneading is preferably performed at a temperature of 180 to 300 ° C., more preferably 200 to 300 ° C., preferably 20 to 700 / sec, in order to obtain a resin composition in which the respective components are more uniformly mixed. Preferably, the shear rate is 30 to 500 / sec.

  As an apparatus used for melt-kneading, a usual mixer or a kneader can be used. Specifically, a single-screw kneader, a twin-screw kneader, a multi-screw extruder, a Henschel mixer, a Banbury mixer, a kneader, a roll mill and the like can be mentioned. When the shear rate is increased within the above range, a high shear processing device or the like may be used.

  The resin compositions (B) and (C) can also be produced, for example, by melt-kneading under the above-mentioned temperature and shear rate in the same manner as the resin composition (A). In addition, for example, when the thermoplastic resin layers (B) and (C) contain one kind of thermoplastic resin, the resin laminate may be manufactured by performing melt extrusion described later without melt-kneading in advance.

  When the intermediate layer (A), the thermoplastic resin layers (B) and (C) contain an additive, the additive may be contained in advance in the resin contained in each layer, and the additive is added at the time of melt kneading of the resin The resin may be added after melt-kneading, or may be added when preparing a resin laminate using the resin composition.

  The resin laminate of the present invention having at least the intermediate layer (A) and the thermoplastic resin layers (B) and (C) respectively present on both sides of the intermediate layer (A) is produced, for example, by melt extrusion, solution casting Each layer (A) to (C) is separately prepared from the resin compositions (A) to (C) by a film forming method, a heat press method, an injection molding method or the like, and these are attached via, for example, an adhesive or adhesive. It may be manufactured by combining, or may be manufactured by laminating and integrating the resin compositions (A) to (C) by melt coextrusion. When manufacturing a resin laminated body by bonding, it is preferable to use the injection molding method and the melt extrusion molding method for preparation of each layer, and it is more preferable to use the melt extrusion molding method. The resin laminate of the present invention is produced by melt co-extrusion molding of the resin compositions (A) to (C), and is generally secondary molding compared to the resin laminate produced by bonding. It is preferable because a resin laminate that is easy to form can be obtained.

  In melt coextrusion molding, for example, the resin composition (A) and the resin compositions (B) and (C) are separately charged into two or three uniaxial or twin extruders and respectively melted After kneading, the intermediate layer (A) formed from the resin composition (A) and the thermoplastic resin layers (B) and (C) are integrally laminated through a feed block die, a multi-manifold die, etc. Molding method. When the resin compositions (B) and (C) are the same composition, one composition melt-kneaded in one extruder is divided into two via a feed block die etc. to obtain a thermoplastic resin layer (B) and (C) may be formed. The obtained resin laminate is preferably cooled and solidified by, for example, a roll unit or the like.

  The resin laminate of the present invention is distributed in the form of a resin laminate having a size of, for example, 500 to 3000 mm in width and 500 to 3000 mm in length obtained by cutting out from the laminate manufactured as described above.

  The resin laminate of the present invention can be used in various display devices. The display device is a device having a display element, and includes a light emitting element or a light emitting device as a light emitting source. As a display device, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (for example, field emission display device (FED), surface field emission display device (SED)), electronic paper (display using electronic ink or electrophoretic element), plasma display, projection display (for example, grating light valve (GLV) display, display having digital micro mirror device (DMD) Devices and piezoelectric ceramic displays. The liquid crystal display device includes any of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, a projection liquid crystal display device and the like. These display devices may be display devices that display two-dimensional images, or may be stereoscopic display devices that display three-dimensional images. The resin laminate of the present invention is suitably used, for example, as a front plate or a transparent electrode in these display devices.

  When the resin laminate of the present invention is used as a transparent electrode in a touch panel or the like, a transparent conductive film is formed on at least one surface of the resin laminate of the present invention to produce a transparent conductive sheet. Can be manufactured.

  As a method of forming a transparent conductive film on at least one surface of the resin laminate of the present invention, the transparent conductive film may be formed directly on the surface of the resin laminate of the present invention, or a transparent conductive film is formed in advance. The plastic film may be laminated on the surface of the resin laminate of the present invention.

  The film substrate of the plastic film on which the transparent conductive film is formed in advance is not particularly limited as long as it is a transparent film and on which the transparent conductive film can be formed. For example, polyethylene terephthalate, polyethylene naphthalate Polycarbonate, acrylic resin, polyamide, a mixture or laminate of these, and the like. In addition, before forming a transparent conductive film, the above-mentioned film may be coated for the purpose of improving surface hardness, preventing Newton rings, imparting antistatic properties, and the like.

  As a method of laminating a film on which a transparent conductive film is formed in advance on the surface of the resin laminate of the present invention, any method may be used as long as a uniform, transparent sheet can be obtained without air bubbles and the like. A method of laminating using an adhesive that cures at normal temperature, heating, ultraviolet light or visible light may be used, or lamination may be performed using a transparent adhesive tape.

  Vacuum deposition, sputtering, CVD, ion plating, spraying and the like are known as methods for forming a transparent conductive film, and these methods should be appropriately used according to the required film thickness. Can.

  In the case of the sputtering method, for example, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, ion assist may be used in combination. Further, if necessary, a bias such as direct current, alternating current or high frequency may be applied to the substrate. As a transparent conductive metal oxide used for the transparent conductive film, indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite An oxide etc. are mentioned. Among these, indium-tin complex oxide (ITO) is preferable from the viewpoint of environmental stability and circuit processability.

  In addition, as a method of forming a transparent conductive film, a coating agent containing various conductive polymers capable of forming a transparent conductive film is applied to the surface of the resin laminate of the present invention, and ionization such as heat or ultraviolet light is performed. A method of curing the coating by irradiating radiation may also be applied. As the conductive polymer, polythiophene, polyaniline, polypyrrole and the like are known, and these conductive polymers can be used.

  The thickness of the transparent conductive film is not particularly limited, but in the case of using a transparent conductive metal oxide, it is usually 50 to 2000 Å, preferably 70 to 000 Å. Within this range, both conductivity and transparency are excellent.

  The thickness of the transparent conductive sheet is not particularly limited, and an optimum thickness can be selected in accordance with the determination of the product specification of the display.

  A touch sensor panel can be manufactured using the resin laminate of the present invention as a display panel face plate and using a transparent conductive sheet produced from the resin laminate of the present invention as a transparent electrode such as a touch screen. Specifically, the resin laminate of the present invention can be used as a window sheet for a touch screen, and a transparent conductive sheet can be used as an electrode substrate of a resistive film type or capacitive type touch screen. By arranging the touch screen on the front surface of a liquid crystal display device, an organic EL display device, or the like, an external touch sensor panel having a touch screen function can be obtained.

  The present invention also provides a display device comprising the resin laminate of the present invention. The display device of the present invention may be, for example, the display device described above.

  The present invention also provides a resin laminate-attached polarizing plate in which the resin laminate of the present invention and the polarizing plate are laminated, and a display device including the resin laminate-attached polarizing plate. In the resin laminate-attached polarizing plate of the present invention, the resin laminate of the present invention is laminated on the polarizing plate via an optical adhesive such as an adhesive and a pressure-sensitive adhesive. Any known adhesive or pressure-sensitive adhesive may be used as appropriate.

  In FIG. 2, one preferable form of the liquid crystal display device containing the resin laminated body of this invention is shown with a cross-sectional schematic diagram. The resin laminate 10 of the present invention may be laminated on the polarizing plate 11 via the optical adhesive layer 12, and this laminate may be disposed on the viewing side of the liquid crystal cell 13. The polarizing plate 11 is usually disposed on the back side of the liquid crystal cell 13. The liquid crystal display device 14 is composed of such members. Note that FIG. 2 is an example of a liquid crystal display device, and the display device of the present invention is not limited to this configuration.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to these examples.

[Vicat softening temperature]
It measured based on B50 method of prescription | regulation to JISK7206: 1999 "plastics-thermoplastics-Vicat softening temperature (VST) test method". The Vicat softening temperature was measured with a heat distortion tester ("148-6 continuous mold" manufactured by Yasuda Seiki Co., Ltd.). The test piece in that case press-formed each raw material to 3 mm thickness, and measured it.

[Content of alkali metal]
It was measured by inductively coupled plasma mass spectrometry.

[MFR]
It measured based on the method prescribed | regulated to JISK 7210: 1999 "The test method of the melt mass flow rate (MFR) and melt volume flow rate (MVR) of a plastics-thermoplastics." With regard to poly (methyl methacrylate) -based materials, it is defined in this JIS that the measurement is performed at a temperature of 230 ° C. and a load of 3.80 kg (37.3 N).

[MVR]
The material of the polycarbonate-based resin was measured at 300 ° C. under a load of 1.2 kg under “Semi-auto Melt Indexer 2A” manufactured by Toyo Seiki Seisaku-sho, Ltd. in accordance with JIS K 7210.

[Total light transmittance and haze]
Haze transmissometer based on JIS K 7361-1: 1997 "Test method of total light transmittance of plastic-transparent material-Part 1: Single beam method"("HR-100" manufactured by Murakami Color Research Laboratory Co., Ltd.) It measured by).

[YI value]
It measured with "Spectrophotometer SQ2000" made from Nippon Denshoku Industries Co., Ltd.

[Average value of film thickness]
The film thickness of the resin laminate was measured by a digital micrometer. The average value obtained by performing the above measurement at 10 points was taken as the average value of the film thickness of the resin laminate.
The film thickness of each of the intermediate layer (A), the thermoplastic resin layer (B) and (C) is measured by cutting the resin laminate perpendicularly to the surface direction and polishing the cross section with sand paper It was measured by observing with a Microsquare microscope. The average value obtained by performing the above measurement at 10 points was taken as the average value of the film thickness of each layer.

［式中、λは複屈折を表し、Ｒは位相差を表し、Ｌは位相差測定用試料の短辺の長さ（ｎｍ）を表す。］
から複屈折（λ）を算出した。このようにして算出した複屈折を複屈折（Ｉ）とする。 [Birefringence of thermoplastic resin layers (B) and (C) in resin laminate (birefringence I)]
The resin laminate was cut in the direction perpendicular to the laminate surface to obtain a rectangular solid having a size of 600 μm short side and 8 mm long side on the surface of the thermoplastic resin layer and having a thickness which is the film thickness of the resin laminate. This was fixed on glass so that the cross section turned upward, to obtain a phase difference measurement sample. Fixing was performed using an epoxy adhesive. The obtained sample is set in an automatic birefringence meter ("KOBRA-CCD" manufactured by Oji Scientific Co., Ltd.) so that the layer to be measured faces the incident side of the measurement light, and the temperature is 23 ± 2 ° C and the humidity is 50 ± 5%. The phase difference (R) at a wavelength of 590 nm was measured. Using the obtained phase difference, the following equation:

[Wherein, λ represents birefringence, R represents a retardation, and L represents the length (nm) of the short side of the retardation measurement sample. ]
The birefringence (λ) was calculated from The birefringence calculated in this manner is referred to as birefringence (I).

[The birefringence (birefringence of the thermoplastic resin layers (B) and (C) in the resin laminate after annealing for 4 hours at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) II)]
In order to remove the influence of distortion during molding, the resin laminate is left in an oven set at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) for 4 hours to perform annealing treatment Thus, a resin laminate for measuring birefringence (II) from which distortion during molding was removed was obtained. The phase difference was measured by the method similar to the measurement of the said birefringence (I) using the obtained resin laminated body, and the birefringence was calculated by substituting it in said formula. The birefringence calculated in this manner is referred to as birefringence (II). When the Vicat softening temperatures of the thermoplastic resin layers (B) and (C) were different, the annealing treatment was performed at a temperature 25 ° C. lower than the higher Vicat softening temperature.

[Evaluation of warpage]
The prepared sheet-like resin laminate was cut into a size of 100 × 56 mm to prepare a sample for warpage evaluation. The sample was allowed to stand in a constant temperature and humidity chamber with a temperature of 60 ° C. and a relative humidity of 90% for 120 hours, and the change in warpage was evaluated before and after that. The evaluation was performed by observing the four end portions of the sample with a high accuracy CCD micrometer manufactured by Keyence Corporation, measuring the height of the generated warpage, and calculating the average value of the warpage heights of the four end portions.

Production Example 1
97.7 parts by mass of methyl methacrylate and 2.3 parts by mass of methyl acrylate are mixed, and 0.05 parts by mass of a chain transfer agent (octyl mercaptan) and 0.1 parts by mass of a releasing agent (stearyl alcohol) are added to obtain a single unit. A mixture of dimers was obtained. In addition, 0.036 parts by mass of a polymerization initiator [1,1-di (tert-butylperoxy) 3,3,5-trimethylcyclohexane] was added to 100 parts by mass of methyl methacrylate to obtain an initiator mixed liquid. The mixture is continuously supplied to the complete mixing type polymerization reactor so that the flow ratio of the monomer mixture and the initiator mixture is 8.8: 1, and the average residence time is 20 minutes, and the average polymerization rate is 54% at a temperature of 175 ° C. It was polymerized to obtain a partial polymer. The resulting partially polymerized product is heated to 200 ° C. and led to a vented devolatilizing extruder, and at 240 ° C., the unreacted monomer is devolatized from the vent, and the polymer after devolatilization is extruded in the molten state After water cooling, it was cut to obtain a pellet-like methacrylic resin (i).

  The obtained pellet-like methacrylic resin composition was analyzed by pyrolysis gas chromatography under the conditions shown below, and each peak area corresponding to methyl methacrylate and acrylic ester was measured. As a result, the methacrylic resin (i) had a structural unit derived from methyl methacrylate of 97.0% by mass and a structural unit derived from methyl acrylate of 3.0% by mass.

[Content of structural unit by pyrolysis gas chromatography]
(Thermal decomposition conditions)
Sample preparation: The methacrylic resin composition was precisely weighed (approximately 2 to 3 mg), placed in the center of the bowl-shaped metal cell, the metal cell was folded, and both ends were lightly pressed with a pliers for encapsulation.
Thermal decomposition system: CURIE POINT PYROLYZER JHP-22 (manufactured by Japan Analytical Industry Co., Ltd.)
Metal cell: Pyrofoil F 590 (manufactured by Japan Analytical Industry Co., Ltd.)
Set temperature of constant temperature bath: 200 ° C
Set temperature of heat insulation pipe: 250 ° C
Thermal decomposition temperature: 590 ° C
Thermal decomposition time: 5 seconds

(Gas chromatography analysis conditions)
Gas chromatography analyzer: GC-14B (made by Shimadzu Corporation)
Detection method: FID
Column: 7G 3.2m x 3.1mmφ (made by Shimadzu Corporation)
Filler: FAL-M (manufactured by Shimadzu Corporation)
Carrier gas: Air / N2 / H2 = 50/100/50 (kPa), 80 ml / min. Temperature rising condition of column: After holding for 15 minutes at 100 ° C., temperature is raised to 150 ° C. at 10 ° C./min, 150 ° C. Hold for 14 minutes INJ temperature: 200 ° C
DET temperature: 200 ° C

A peak area (a1) corresponding to methyl methacrylate detected when the methacrylic resin composition is thermally decomposed under the above thermal decomposition conditions and the generated decomposition product is measured under the above gas chromatography analysis conditions and an acrylic ester The peak area (b1) corresponding to was measured. And peak area ratio A (= b1 / a1) was calculated from these peak areas. On the other hand, a standard product of a methacrylic resin having a weight ratio of acrylic acid ester units to methyl methacrylate units of W ₀ (known) is thermally decomposed under the above thermal decomposition conditions, and generated decomposition products are subjected to the above gas chromatography analysis conditions The peak area (a ₀ ) corresponding to methyl methacrylate detected when the measurement was performed and the peak area (b ₀ ) corresponding to the acrylic ester were measured. From these peak areas, the peak area ratio A ₀ (= b ₀₎ / A ₀ ) was obtained. Then, a factor f (= W ₀ / A ₀ ) was determined from the peak area ratio A ₀ and the weight ratio W ₀ .
The weight ratio W of acrylic ester units to methyl methacrylate units in the copolymer contained in the methacrylic resin composition is determined by multiplying the peak area ratio A by the factor f, and from the weight ratio W, methacrylic acid is determined The ratio (% by mass) of methyl methacrylate units to the total of methyl units and acrylic ester units and the ratio (% by mass) of acrylate units to the total were calculated.

Production Example 2
A pellet-like methacrylic resin (ii) was prepared in the same manner as in Production Example 1 except that 98.9 parts by mass of methyl methacrylate, 1.1 parts by mass of methyl acrylate and 0.16 parts by mass of the chain transfer agent were changed. The content of structural units was measured. The methacrylic resin (ii) had a structural unit derived from methyl methacrylate of 97.5% by mass and a structural unit derived from methyl acrylate of 2.5% by mass.

Production Example 3
Acrylic rubber particles having a spherical three-layer structure and having an average particle diameter of 0.22 μm were produced according to Example 3 of JP-B-55-27576 and used as acrylic rubber particles (i). Acrylic rubber particles (i) is an innermost layer which is a hard polymer polymerized using methyl methacrylate and a small amount of allyl methacrylate, further using butyl acrylate as a main component and further using styrene and a small amount of allyl methacrylate It has an intermediate layer which is a polymerized elastic polymer, and an outermost layer which is a hard polymer polymerized using methyl methacrylate and a small amount of methyl acrylate. The average particle diameter of the acrylic rubber particles (i) is made by mixing the acrylic rubber particles with the methacrylic resin to form a film, and using ruthenium oxide in the film cross section to dye the elastic polymer (intermediate layer), and electron microscope And the diameter of the stained part was measured and determined.
65 parts of pellets of methacrylic resin (i) and 35 parts of the above-mentioned acrylic rubber particles (i) were mixed by a super mixer and melt-kneaded by a twin screw extruder to obtain pellets.

Physical properties of the methacrylic resins (i) to (iii) obtained in Production Examples 1 to 3 are shown in Table 1.

Production Example 4
In order to make a bluing agent into a master batch (MB), 99.99 parts by weight of the methacrylic resin (i) obtained in Production Example 1 and 0.01 parts by weight of a coloring agent were dry-blended with a 40 mm φ single screw extruder ( The mixture was melt mixed at a set temperature of 250 to 260 ° C. by Tanabe Plastic Machinery Co., Ltd.) to obtain a colored master batch pellet (MB (i)). As a coloring agent, a bluing agent ("Sumiplast (registered trademark) Violet B" manufactured by Sumika Chemtex Co., Ltd.) was used.

In Examples and Comparative Examples, commercially available vinylidene fluoride resins having the physical properties shown in Table 2 were used.
Vinylidene fluoride resin (i): Polyvinylidene fluoride resin produced by suspension polymerization (ii): Polyvinylidene fluoride manufactured by emulsion polymerization

  The weight average molecular weight (Mw) of the vinylidene fluoride resin was measured by gel permeation chromatography (GPC). Using polystyrene as a standard reagent, a calibration curve was prepared from elution time and molecular weight, and the weight average molecular weight of each resin was measured. Specifically, 40 mg of resin was dissolved in 20 ml of N-methyl pyrrolidone (NMP) solvent to prepare a measurement sample. As a measurement apparatus, two “TSKgel SuperHM-H” columns manufactured by Tosoh Corp. and one “SuperH2500” were arranged in series and used, and a detector employing an RI detector was used.

In the examples and comparative examples, the following commercially available products were used as polycarbonate resins. Physical properties of the resin are shown in Table 3.
Polycarbonate resin (i): "Karibar (registered trademark) 301-30" manufactured by Sumika Styron Polycarbonate Co., Ltd.

  The weight average molecular weight of the polycarbonate resin was measured by GPC. A methacrylic resin manufactured by Showa Denko K. K., which has a narrow molecular weight distribution and a known molecular weight, is used as a standard reagent, and a calibration curve is prepared from the elution time and the molecular weight to measure the weight average molecular weight. Specifically, 40 mg of resin was dissolved in 20 ml of tetrahydrofuran (THF) solvent to prepare a measurement sample. As a measurement apparatus, two “TSKgel SuperHM-H” columns manufactured by Tosoh Corp. and one “SuperH2500” were arranged in series and used, and a detector employing an RI detector was used.

[Production of Resin Laminates of Examples 1 to 3 and Comparative Examples 1 to 6]
For mixing the methacrylic resin and vinylidene fluoride resin shown in Tables 1 and 2 and the master batch pellet MB (i) obtained in Production Example 4 in the proportions shown in Table 4 to form an intermediate layer (A) A resin composition (A) was obtained. As resin compositions (B) and (C) for forming the thermoplastic resin layers (B) and (C), the methacrylic resin shown in Table 1, the mixture obtained in Production Example 3 or the polycarbonate resin shown in Table 3 It was used. A resin laminate was produced from these resin compositions using the apparatus shown in FIG. Specifically, the resin composition (A) is a 65 mm single-screw extruder 2 (manufactured by Toshiba Machine Co., Ltd.), and the resin compositions (B) and (C) are 45 mm single-screw extruders 1 and 3 (Hitachi Shipbuilding Co., Ltd.) ], Respectively. Subsequently, these are supplied to a three-kind three-layer distribution type feed block 4 having a set temperature of 230 to 270 ° C. and distributed so as to form a three-layer configuration, and then a multi-manifold type die 5 [manufactured by Hitachi Zosen Co., Ltd .; Distribution] The resultant was extruded to be laminated so as to have a configuration represented by B layer / A layer / C layer, and a film-like molten resin 6 was obtained. The obtained film-like molten resin 6 is sandwiched between a first cooling roll 7 (diameter 350 mm) and a second cooling roll 8 (diameter 450 mm) opposite to each other, and then wound around the second roll 8 while the second After being sandwiched between the roll 8 and the third roll 9 (diameter 350 mm), it is wound around the third cooling roll 9, molded and cooled, and each layer has a three-layer constitution having an average value of film thickness shown in Table 4 The resin laminate 10 was obtained. The obtained resin laminates 10 all had a total film thickness of about 800 μm and were colorless and transparent when visually observed.

Table 5 shows the temperature of each cooling roll at the time of production of the resin laminate, the take-up speed, and the temperature of the discharged resin obtained by measuring the resin discharged from the die with a non-contact thermometer.

The results of measurement of ΔL, Δλ _B , Δλ _C , Δλ _BC and ΔT of the thermoplastic resin layers (B) and (C) of the resin laminates of Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 6 below. Shown in.

  In the resin laminates of Examples 1 to 3 and Comparative Examples 1 to 5, the alkali metal (Na and K) content in the intermediate layer (A) is 0.3 ppm in Examples 1 and 2 and Comparative Examples 1 to 5. In Example 3, it was 100 ppm.

  The dielectric constants of the resin laminates of Examples 1 to 3 and Comparative Examples 1 to 5 are 5.2 for Example 1 and Comparative Examples 2, 3 and 5, 5.3 for Example 2, and Comparative Examples 1 and 4. In Example 5, it was 4.9. It was confirmed that any resin laminate had a dielectric constant sufficient for use in a display device such as a touch panel.

The resin laminates of Examples 1 to 3 and Comparative Examples 1 to 5 were used to evaluate the total light transmittance (Tt), the haze, and the warpage. The obtained results are shown in Table 7. Furthermore, the resin laminates of Examples 1 to 3 and Comparative Examples 1 to 5 are exposed to an environment of 90% relative humidity at 60 ° C. for 120 hours, and the evaluation of warpage is similarly performed on the resin laminates after the endurance test. went. The results after the endurance test are also shown in Table 7.

  It was found that the resin laminates of the present invention shown in Examples 1 to 3 have high transparency and are not easily warped. Furthermore, the resin laminates of the present invention shown in Examples 1 to 3 were hardly warped even after the endurance test under high temperature and high humidity conditions.

1 Single screw extruder (extruding the melt of resin composition B)
2 Single screw extruder (extruding the melt of resin composition A)
3 Single screw extruder (extruding the melt of resin composition C)
4 feed block 5 multi-manifold type die 6 film-like molten resin 7 first cooling roll 8 second cooling roll 9 third cooling roll 10 resin laminate 10A middle layer (A)
10B Thermoplastic resin layer (B)
10C Thermoplastic resin layer (C)
11 polarizing plate 12 optical adhesive layer 13 liquid crystal cell 14 liquid crystal display device

Claims (15)

A resin laminate obtained by melt coextrusion, comprising at least an intermediate layer (A) and thermoplastic resin layers (B) and (C) respectively present on both sides of the intermediate layer (A),
The intermediate layer (A) contains 10 to 90% by mass of (meth) acrylic resin and 90 to 10% by mass of vinylidene fluoride resin based on the total amount of resin contained in the intermediate layer (A); The weight average molecular weight (Mw) of the (meth) acrylic resin is 100,000 to 300,000,
The thermoplastic resin layers (B) and (C) have the following relationship:

[In the formula,
L _B and L _C respectively represent the average value of the film thickness of the thermoplastic resin layers (B) and (C),
Δλ _B is the following formula:

Represented by
Δλ _C has the following formula:

Represented by
λ ′ _B and λ ′ _C represent birefringence (I) measured for the thermoplastic resin layers (B) and (C) in the resin laminate, respectively
λ _B and λ _C are the thermoplastic resin layers (B) and (B) in the resin laminate after annealing for 4 hours at a temperature 25 ° C. lower than the Vicat softening temperature of the thermoplastic resin layers (B) and (C) Represents the birefringence (II) measured for C),
T _B and _{T C,} respectively, represent a Vicat softening temperature of the thermoplastic resin layer (B) and (C). ]
Meet the resin laminate.   The interlayer (A) contains 35 to 45% by mass of (meth) acrylic resin and 65 to 55% by mass of vinylidene fluoride resin, based on the total amount of resin contained in the interlayer (A). The resin laminated body as described in.   The resin laminated body of Claim 1 or 2 whose content of the alkali metal in an intermediate | middle layer (A) is 50 ppm or less based on all the resin contained in this intermediate | middle layer (A). (Meth) acrylic resin,
Structural units derived from 50 to 99.9% by mass of methyl methacrylate based on all the structural units constituting (a1) methyl methacrylate homopolymer and / or (a2) polymer, and 0.1 Formula (1) of ̃50% by mass:

[Wherein, R ₁ represents a hydrogen atom or a methyl group, and when R ₁ is a hydrogen atom, R ₂ represents an alkyl group having 1 to 8 carbon atoms, and when R ₁ is a methyl group, R ₂ has 2 to 2 carbon atoms] 8 represents an alkyl group. ]
The resin laminated body in any one of Claims 1-3 which is a copolymer containing the at least 1 structural unit derived from the (meth) acrylic acid ester shown by these.   The resin laminate according to any one of claims 1 to 4, wherein the vinylidene fluoride resin is polyvinylidene fluoride.   The resin laminate according to any one of claims 1 to 5, wherein the melt mass flow rate of the vinylidene fluoride resin is 0.1 to 40 g / 10 min as measured at 230 ° C under a load of 3.8 kg.   The average value of the film thickness of the resin laminate is 100 to 2000 μm, and the average value of the film thicknesses of the thermoplastic resin layers (B) and (C) is 10 to 200 μm, respectively. Resin laminate.   The resin laminated body in any one of Claims 1-7 whose Vicat softening temperature of the thermoplastic resin contained in a thermoplastic resin layer (B) and (C) is 100-160 degreeC, respectively.   The resin laminate according to any one of claims 1 to 8, wherein the thermoplastic resin layers (B) and (C) are a (meth) acrylic resin layer or a polycarbonate resin layer.   The thermoplastic resin layers (B) and (C) are polycarbonate resin layers, and contain 0.005 to 2.0% by mass of an ultraviolet absorber based on the total resin contained in each of the thermoplastic resin layers. The resin laminated body in any one of 1-9.   The thermoplastic resin layers (B) and (C) contain 50% by mass or more of (meth) acrylic resin based on the total resin contained in the respective thermoplastic resin layers. Resin laminate.   The resin laminated body of Claim 11 whose weight average molecular weight of the (meth) acrylic resin contained in a thermoplastic resin layer (B) and (C) is 50,000-300,000.   The display apparatus containing the resin laminated body in any one of Claims 1-12.   A polarizing plate with a resin laminate, wherein the resin laminate according to any one of claims 1 to 12 and the polarizing plate are laminated.   A display device comprising the resin laminate-attached polarizing plate according to claim 14.

Images