JPWO2019225676A1 - Extruded resin plate, its manufacturing method, and laminated plate - Google Patents

Abstract

The present invention provides an extruded resin plate in which the rate of decrease in the Re value due to heating is small and the occurrence of warpage due to heating is small. A thermoplastic resin laminate in which a methacrylic resin-containing layer is laminated on at least one side of a polycarbonate-containing layer (glass transition temperature: Tg (PC)) is co-extruded from a T-die in a molten state and cooled using a plurality of cooling rolls. Overall temperature of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll: TX, the entire thermoplastic resin laminate at the position where it peels off from the last cooling roll. Temperature: TT, Overall temperature of the thermoplastic resin laminate within 1 m downstream from the position where it is peeled off from the last cooling roll: TM, Peripheral speed of the take-up roll: V4, Peripheral speed of the second cooling roll: V2. TX (° C.) ≥ Tg (PC) +15, Tg (PC) + 5 ≤ TT (° C.) ≤ Tg (PC) +19, TT-TM (° C.) ≤ 20, 0.98 ≤ V4 / V2 <1.0.

Description

The present invention relates to an extruded resin plate, a method for producing the same, and a laminated plate including the extruded resin plate.

Flat panel displays such as liquid crystal displays and touch panel displays that combine such flat panel displays and touch panels (also called touch screens) are ATMs of financial institutions such as banks; vending machines; mobile phones (including smartphones), It is used in personal digital assistants (PDAs) such as tablet-type personal computers, digital audio players, portable game machines, copy machines, fax machines, and digital information devices such as car navigation systems.
In order to prevent scratches on the surface, a transparent protective plate is installed on the surface of a flat panel display such as a liquid crystal display and a touch panel. Conventionally, tempered glass has been mainly used as a protective plate, but a transparent resin plate has been developed from the viewpoint of workability and weight reduction. The protective plate is required to have functions such as gloss, scratch resistance, and impact resistance.

By forming a (half) mirror film on the surface of the protective plate, the protective plate can be used as a (half) mirror plate. In the present specification, "(half) mirror" is a general term for a mirror and a half mirror.
For example, in applications such as rear-view mirrors for vehicles, mirrors with a liquid crystal monitor that combine a liquid crystal monitor and a (half) mirror plate have been developed. Conventionally, a glass plate has been mainly used as a substrate for a (half) mirror plate, but from the viewpoint of workability, weight reduction, and visibility when viewing the screen through a polarizing filter such as polarized sunglasses, a transparent resin substrate is used. Is being developed. In addition to the above-mentioned functions required for a general protective plate, this transparent resin substrate is required to have low warpage performance close to that of glass from the viewpoint of suppressing distortion of the reflected image.

As a protective plate made of a transparent resin, a resin plate containing a polycarbonate layer having excellent impact resistance and a methacrylic resin layer having excellent gloss and scratch resistance has been studied. This resin plate is preferably manufactured by coextrusion molding. In this case, strain stress may remain on the obtained resin plate due to the difference in the characteristics of the two types of resin. The strain stress remaining on the resin plate is called "residual stress", and the resin plate having this residual stress may warp or the like due to a thermal change or the like.

As a method of reducing residual stress in a resin plate and suppressing the occurrence of warpage, Patent Document 1 discloses a method of adjusting the rotation speed of a cooling roll used for extrusion molding (claim 1). In Patent Document 2, as a methacrylic resin to be laminated with polycarbonate, a methacrylic acid ester such as methyl methacrylate (MMA) and an aromatic vinyl monomer such as styrene are copolymerized, and then the aromatic double bond is hydrogenated. A method using the obtained resin is disclosed (claim 2).

Further, in order to solve the above problems, improvement of heat resistance and moisture resistance of methacrylic resin is being studied. For example, Patent Document 3 describes MMA units, methacrylic acid (MA) units, acrylic acid (AA) units, maleic acid anhydride units, N-substituted or unsubstituted mylemid units, and glutar as methacrylic resins to be laminated with polycarbonate. A method of using a resin having an acid anhydride structural unit and a unit selected from a glutarimide structural unit and having a glass transition temperature (Tg) of 110 ° C. or higher is disclosed (claim 1).
In addition, in Patent Document 4, in a decorative sheet in which two resin sheets are laminated with at least one pattern layer sandwiched between them, the difference in the coefficient of linear expansion (also referred to as the coefficient of linear expansion) between the two resin sheets is small. The method of doing so is disclosed (claim 1).

A cured film having scratch resistance (hard coat property) and / or low reflectivity for improving visibility can be formed on at least one surface of the protective plate (claims 1 and 2 of Patent Document 5). , And claim 1 of Patent Document 6).
The protective plate for the liquid crystal display is installed on the front side (viewer side) of the liquid crystal display, and the viewer sees the screen of the liquid crystal display through the protective plate. Here, since the protective plate hardly changes the polarization property of the emitted light from the liquid crystal display, when the screen is viewed through a polarizing filter such as polarized sunglasses, the angle formed by the polarizing axis of the emitted light and the transmission axis of the polarizing filter depends on the angle. , The screen may become dark and the visibility of the image may be reduced. Therefore, a protective plate for a liquid crystal display that can suppress a decrease in visibility of an image when the screen of the liquid crystal display is viewed through a polarizing filter has been studied. For example, Patent Document 7 describes a liquid crystal display protective plate which is made of a scratch-resistant resin plate having a cured film formed on at least one surface of a resin substrate and has an in-plane retardation value (Re) of 85 to 300 nm. It is disclosed (claim 1).

In general, in an extruded resin plate, stress may be generated during molding, which may cause molecules to be oriented and retardation to occur (see paragraph 0034 of Patent Document 8). Further, in an extruded resin plate including a plurality of resin layers, the degree of residual stress of each resin layer may be different. Further, in the molding of the extruded resin plate, when the extruded resin plate is separated from the final cooling roll, a streak-like defect (so-called chatter mark) may occur on the surface of the extruded resin plate, and the surface property may be deteriorated. By adjusting the manufacturing conditions such as the rotation speed of the cooling roll and the take-up roll used for extrusion molding, the stress and chatter mark generated during molding can be reduced.

For example, in order to reduce the stress generated during molding of the extruded resin plate and suppress the decrease in the Re value, Patent Documents 8 and 9 include an extruded resin plate in which a methacrylic resin layer is laminated on at least one surface of the polycarbonate layer. A method for manufacturing an extruded resin plate that optimizes manufacturing conditions such as the relationship between the peripheral speeds of a plurality of cooling rolls and a take-up roll and the temperature of the entire resin at the time of peeling from the final cooling roll during extrusion molding is disclosed. (Patent Document 8 Claim 1, Patent Document 9, Claims 3, 4, etc.).
Further, in order to reduce the stress generated during molding of the extruded resin plate and suppress the decrease in the Re value, Patent Document 10 describes coextrusion molding of an extruded resin plate in which a methacrylic resin layer is laminated on at least one surface of a polycarbonate layer. Disclosed is a method for manufacturing an extruded resin plate in which the relationship between the peripheral speeds of a plurality of cooling rolls and the take-up rolls and the manufacturing conditions such as the temperature of the entire resin at the time of peeling from the last cooling roll are optimized. (Claim 1 of Patent Document 10).

Japanese Unexamined Patent Publication No. 2007-185956 International Publication No. 2011/145630 Japanese Unexamined Patent Publication No. 2009-248416 Japanese Unexamined Patent Publication No. 2007-118597 Japanese Unexamined Patent Publication No. 2004-299199 Japanese Unexamined Patent Publication No. 2006-103169 Japanese Unexamined Patent Publication No. 2010-0857978 International Publication No. 2015/093037 International Publication No. 2016/0388868 International Publication No. 2017/1642776

In the step of forming a cured film having scratch resistance (hard coat property) and / or low reflectivity on the surface of the transparent resin plate, the transparent resin plate may be heated to a temperature of 100 ° C. or higher. For example, a thermosetting coating material requires heating to cure, and a photocurable coating material receives heat during light irradiation. If the coating material contains a solvent, it may be heated to dry the solvent.
Also in the step of forming the (half) mirror film on the surface of the transparent resin plate, the transparent resin plate may be heated to a temperature of 100 ° C. or higher when the coating material is heat-treated.
In addition, a protective plate for a liquid crystal display mounted on an in-vehicle display device such as a car navigation system or a mobile phone (including a smartphone) may be used in a high temperature environment such as summer sunshine.
When the resin plate is exposed to a high temperature in the manufacturing process or the usage environment in this way, the Re value may decrease due to heat and may be out of the desired range. It is preferable that the thermal change of the Re value is small. The resin plate used as the substrate of the (half) mirror plate used for a mirror with a liquid crystal monitor or the like preferably has a small amount of warpage even when exposed to a high temperature from the viewpoint of suppressing distortion of the reflected image.

The present invention has been made in view of the above circumstances, and the in-plane retardation value (Re) is within a range suitable for a flat panel display such as a liquid crystal display and a protective plate such as a touch panel, and the Re value due to heating. It is an object of the present invention to provide an extruded resin plate having a small reduction rate, less warpage due to heating, and good surface properties, and a method for producing the extruded resin plate.
Although the present invention is suitable as a protective plate for a flat panel display such as a liquid crystal display and a touch panel, it can be used for any purpose.

The present invention provides the following extruded resin plates [1] to [13], a method for producing the same, and a laminated plate.
[1] A method for producing an extruded resin plate in which a layer containing a methacrylic resin is laminated on at least one surface of a layer containing polycarbonate.
A thermoplastic resin laminate in which the layer containing the methacrylic resin is laminated on at least one surface of the layer containing the polycarbonate is co-extruded from the T-die in a molten state.
Using three or more cooling rolls adjacent to each other, the molten thermoplastic resin laminate is sandwiched between the nth (where n ≧ 1) cooling roll and the n + 1th cooling roll. Cooling is performed by repeating the operation of winding on the n + 1th cooling roll multiple times from n = 1.
The step (X) of picking up the extruded resin plate obtained after cooling by a picking roll is included.
The overall temperature (TX) of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll is set to the glass transition temperature of the layer containing the polycarbonate. On the other hand, the temperature should be + 15 ° C or higher.
The overall temperature (TT) of the thermoplastic resin laminate at the position where it is finally peeled off from the cooling roll is set in the range of + 5 ° C. to + 19 ° C. with respect to the glass transition temperature of the layer containing the polycarbonate.
The overall temperature (TT) of the thermoplastic resin laminate at the position of peeling from the last cooling roll and the overall temperature (TM) of the thermoplastic resin laminate within 1 m downstream from the position of peeling from the last cooling roll. The difference from (TT-TM) is set to 20 ° C or less.
The extruded resin plate having a peripheral speed ratio (V4 / V2) of the peripheral speed (V4) of the take-up roll and the peripheral speed (V2) of the second cooling roll set to 0.98 or more and less than 1.0. Production method.

[2] The glass transition temperature of the layer containing the methacrylic resin is 115 ° C. or higher.
The difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer and the linear expansion coefficient (S1) of the polycarbonate-containing layer. ) To ((S2-S1) / S1) is −10% to + 10%, the method for producing an extruded resin plate according to [1].

[3] The layer containing the methacrylic resin is composed of 5 to 80% by mass of the methacrylic resin and 95 to 20% by mass of a copolymer containing a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride. The method for producing an extruded resin plate according to [1] or [2], which comprises.
[4] The copolymer has a structural unit of 50 to 84% by mass derived from the aromatic vinyl compound, a structural unit of 15 to 49% by mass derived from maleic anhydride, and a structural unit 1 to 1 derived from a methacrylic acid ester. The method for producing an extruded resin plate according to [3], which contains 35% by mass.

[5] After the step (X), the extruded resin plate further includes a step (Y) of heating the extruded resin plate at a temperature of 75 to 125 ° C. for 1 to 30 hours.
Both before and after heating, the extruded resin plate has a warp amount of 0 to ± 0.2 mm measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding. 1] A method for producing an extruded resin plate according to any one of [4].
[6] After the step (X), the step (Y) of heating the extruded resin plate at a temperature of 75 to 125 ° C. for 1 to 30 hours is further included.
Both before and after heating, the extruded resin plate has at least a partial in-plane retardation value in the width direction of 50 to 330 nm, and the rate of decrease of the retardation value of the extruded resin plate after heating with respect to before heating. The method for producing an extruded resin plate according to any one of [1] to [5], wherein the amount is less than 30%.

[7] An extruded resin plate in which a layer containing a methacrylic resin is laminated on at least one side of a layer containing polycarbonate.
The glass transition temperature of the layer containing the methacrylic resin is 115 ° C. or higher.
Warpage measured for rectangular test pieces with a width direction of 200 mm during extrusion and a flow direction of 100 mm during extrusion before and after heating at a constant temperature within the range of 75 to 125 ° C. for 5 hours. The amount is 0 to ± 0.2 mm,
At least some in-plane retardation values in the width direction are 50-330 nm.
The rate of decrease of the retardation value after heating with respect to that before heating is less than 30%.
The difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer and the linear expansion coefficient (S1) of the polycarbonate-containing layer. ) To ((S2-S1) / S1) is -10% to + 10%, an extruded resin plate.

[8] When the extruded resin plate is heated at a temperature of 75 ° C. or 125 ° C. for 5 hours, a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding both before and after heating. The amount of warpage measured for is 0 to ± 0.2 mm.
At least some in-plane retardation values in the width direction are 50-330 nm.
The extruded resin plate of [7], wherein the reduction rate of the retardation value after heating is less than 30% with respect to that before heating.
[9] The amount of warpage measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding is 0 to ± 0.15 mm both before and after heating, [7] or The extruded resin plate of [8].
[10] The extruded resin plate according to any one of [7] to [9], wherein at least a partial in-plane retardation value in the width direction is 80 to 250 nm both before and after heating.
[11] The extruded resin plate according to any one of [7] to [10], wherein the reduction rate of the retardation value after heating is less than 15% with respect to that before heating.

[12] A laminated board including the extruded resin plate according to any one of [7] to [11] and a scratch-resistant layer formed on at least one surface of the extruded resin plate.
[13] A laminated plate comprising the extruded resin plate according to any one of [7] to [11] and a mirror film or a half mirror film formed on at least one surface of the extruded resin plate.

According to the present invention, the in-plane retardation value (Re) is within a range suitable for a flat panel display such as a liquid crystal display and a protective plate for a touch panel, etc. It is possible to provide an extruded resin plate having less warpage and good surface properties and a method for producing the extruded resin plate.

It is a schematic cross-sectional view of the extruded resin plate of 1st Embodiment which concerns on this invention. It is a schematic cross-sectional view of the extruded resin plate of the 2nd Embodiment which concerns on this invention. It is a schematic diagram of the manufacturing apparatus of the extruded resin plate of one Embodiment which concerns on this invention.

[Extruded resin plate]
The present invention relates to a flat panel display such as a liquid crystal display, a protective plate such as a touch panel, and an extruded resin plate suitable as a protective plate and (half) mirror plate included in a mirror with a liquid crystal monitor or the like.
The extruded resin plate of the present invention is a layer containing methacrylic resin (PM) on at least one side of a layer containing polycarbonate (PC) (hereinafter, also simply referred to as a polycarbonate-containing layer) (hereinafter, also simply referred to as a methacrylic resin-containing layer). Are laminated.
Polycarbonate (PC) has excellent impact resistance, and methacrylic resin (PM) has excellent gloss, transparency, and scratch resistance. Therefore, the extruded resin plate of the present invention in which these resins are laminated is excellent in gloss, transparency, impact resistance, and scratch resistance. Further, since the extruded resin plate of the present invention is manufactured by an extrusion molding method, it is excellent in productivity.

(Methyl resin-containing layer)
The methacrylic resin-containing layer contains one or more methacrylic resins (PM). The methacrylic resin (PM) is a homopolymer or copolymer containing a structural unit derived from one or more methacrylic acid hydrocarbon esters (hereinafter, also simply referred to as methacrylic acid esters), preferably containing methyl methacrylate (MMA). Is.
The hydrocarbon group in the methacrylic acid ester may be a non-cyclic aliphatic hydrocarbon group such as a methyl group, an ethyl group and a propyl group, an alicyclic hydrocarbon group, or an aromatic group such as a phenyl group. It may be a hydrocarbon group.
From the viewpoint of transparency, the content of the methacrylic ester monomer unit in the methacrylic resin (PM) is preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. It may be 100% by mass.

The methacrylic resin (PM) may contain structural units derived from one or more other monomers other than the methacrylic ester. Other monomers include methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, acrylic. 2-Ethylhexyl acrylate, Nonyl acrylate, Decyl acrylate, Dodecyl acrylate, Stearyl acrylate, 2-Hydroxyethyl acrylate, 2-Hydroxypropyl acrylate, 4-Hydroxybutyl acrylate, Cyclohexyl acrylate, 2-2-Acrylic acid Methoxyethyl, 3-methoxybutyl acrylate, trifluoromethyl acrylate, trifluoroethyl acrylate, pentafluoroethyl acrylate, glycidyl acrylate, allyl acrylate, phenyl acrylate, toluyl acrylate, benzyl acrylate, acrylate Acrylic acid esters such as isobornyl and 3-dimethylaminoethyl acrylate can be mentioned. Among them, MA, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate and the like are preferable, and MA and ethyl acrylate and the like are preferable from the viewpoint of availability. Is more preferable, and MA is particularly preferable. The content of the structural unit derived from other monomers in the methacrylic resin (PM) is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

The methacrylic resin (PM) is preferably obtained by polymerizing one or more methacrylic acid esters containing MMA and, if necessary, other monomers. When a plurality of types of monomers are used, usually, a plurality of types of monomers are mixed to prepare a monomer mixture, and then polymerization is performed. The polymerization method is not particularly limited, and from the viewpoint of productivity, a radical polymerization method such as a massive polymerization method, a suspension polymerization method, a solution polymerization method, and an emulsion polymerization method is preferable.

The weight average molecular weight (Mw) of the methacrylic resin (PM) is preferably 40,000 to 500,000. When Mw is 40,000 or more, the methacrylic resin-containing layer is excellent in scratch resistance and heat resistance, and when Mw is 500,000 or less, the methacrylic resin-containing layer is excellent in moldability.
In the present specification, unless otherwise specified, "Mw" is a standard polystyrene-equivalent value measured using gel permeation chromatography (GPC).

In the present specification, the glass transition temperature of the methacrylic resin-containing layer is represented by Tg (M). Tg (M) is not particularly limited, and an extruded resin plate having good surface properties and small warpage due to residual stress can be easily obtained. Therefore, the lower limit of Tg (M) is preferably 115 ° C., more preferably 120 ° C. ° C., particularly preferably 125 ° C., most preferably 130 ° C., and the upper limit of Tg (M) is preferably 160 ° C., more preferably 155 ° C., particularly preferably 150 ° C.

<Methyl resin composition (MR)>
The methacrylic resin-containing layer can contain methacrylic resin (PM) and, if necessary, one or more other polymers.
For example, the methacrylic resin-containing layer can be made of a methacrylic resin composition (MR) containing a methacrylic resin (PM) and an SMA resin (S) (hereinafter, also simply referred to as a resin composition (MR)).
As used herein, the term "SMA resin" includes structural units derived from one or more aromatic vinyl compounds and structural units derived from one or more acid anhydrides containing maleic anhydride (MAH). More preferably, it is a copolymer containing a structural unit derived from a methacrylic acid ester.
The methacrylic resin composition (MR) can preferably contain 5 to 80% by mass of the methacrylic resin (PM) and 95 to 20% by mass of the SMA resin (S).

From the viewpoint of setting Tg (M) to 115 ° C. or higher, the content of the methacrylic resin (PM) in the resin composition (MR) is preferably 5 to 80% by mass, more preferably 5 to 55% by mass. Particularly preferably, it is 10 to 50% by mass.

The SMA resin (S) is a copolymer containing a structural unit derived from one or more aromatic vinyl compounds and one or more acid anhydrides containing MAH.
Aromatic vinyl compounds include styrene (St); nuclear alkyl-substituted styrenes such as 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, and 4-tert-butylstyrene; α-methylstyrene. And α-alkyl substituted styrenes such as 4-methyl-α-methylstyrene; Of these, styrene (St) is preferable from the viewpoint of availability. From the viewpoint of transparency and moisture resistance of the resin composition (MR), the content of the aromatic vinyl compound monomer unit in the SMA resin (S) is preferably 50 to 84% by mass, more preferably 55 to 82. It is by mass, particularly preferably 60 to 80% by mass.
As the acid anhydride, at least maleic anhydride (MAH) is used from the viewpoint of availability, and if necessary, other acid anhydrides such as citraconic anhydride and dimethyl maleic anhydride can be used. From the viewpoint of transparency and heat resistance of the resin composition (MR), the content of the acid anhydride monomer unit in the SMA resin (S) is preferably 15 to 49% by mass, more preferably 18 to 45% by mass. %, Especially preferably 20 to 40% by mass.

The SMA resin (S) can contain structural units derived from one or more methacrylic acid ester monomers in addition to aromatic vinyl compounds and acid anhydrides. Examples of the methacrylic acid ester include MMA, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate. Examples thereof include 2-ethylhexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 1-phenylethyl methacrylate and the like. Of these, an alkyl methacrylate ester having an alkyl group having 1 to 7 carbon atoms is preferable. MMA is particularly preferable from the viewpoint of heat resistance and transparency of the SMA resin (S). From the viewpoint of bendability and transparency of the extruded resin plate, the content of the methacrylic ester monomer unit in the SMA resin (S) is preferably 1 to 35% by mass, more preferably 3 to 30% by mass. Particularly preferably, it is 5 to 26% by mass. In this case, the content of the aromatic vinyl compound monomer unit is preferably 50 to 84% by mass, and the content of the acid anhydride monomer unit is preferably 15 to 49% by mass.

The SMA resin (S) has a structural unit of 50 to 84% by mass derived from an aromatic vinyl compound, a structural unit of 15 to 49% by mass derived from maleic anhydride, and a structural unit of 1 to 35% by mass derived from a methacrylic acid ester. Is preferably contained.

The SMA resin (S) may have structural units derived from other monomers other than aromatic vinyl compounds, acid anhydrides, and methacrylic acid esters. As the other monomer, those described above can be used in the description of the methacrylic resin (PM). The content of the other monomer unit in the SMA resin (S) is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

The SMA resin (S) is obtained by polymerizing an aromatic vinyl compound, an acid anhydride, a methacrylic acid ester if necessary, and another monomer if necessary. In this polymerization, usually, a plurality of kinds of monomers are mixed to prepare a monomer mixture, and then the polymerization is carried out. The polymerization method is not particularly limited, and a radical polymerization method such as a massive polymerization method and a solution polymerization method is preferable from the viewpoint of productivity.

The Mw of the SMA resin (S) is preferably 40,000 to 300,000. When Mw is 40,000 or more, the methacrylic resin-containing layer is excellent in scratch resistance and impact resistance, and when Mw is 300,000 or less, the methacrylic resin-containing layer is excellent in moldability.

From the viewpoint of setting Tg (M) to 115 ° C. or higher, the content of the SMA resin (S) in the resin composition (MR) is preferably 20 to 95% by mass, more preferably 45 to 95% by mass. Particularly preferably, it is 50 to 90% by mass.

The resin composition (MR) is obtained, for example, by mixing a methacrylic resin (PM) and a SMA resin (S). Examples of the mixing method include a melt mixing method and a solution mixing method. In the melt mixing method, a single-screw or multi-screw kneader, an open roll, a Banbury mixer, a melt kneader such as a kneader, or the like is used, and if necessary, an inert gas such as nitrogen gas, argon gas, or helium gas is used. Melt kneading can be performed in an atmosphere. In the solution mixing method, the methacrylic resin (PM) and the SMA resin (S) can be dissolved in an organic solvent such as toluene, tetrahydrofuran, and methyl ethyl ketone and mixed.

In one embodiment, the methacrylic resin-containing layer can contain a methacrylic resin (PM) and, optionally, one or more other polymers.
In another embodiment, the methacrylic resin-containing layer comprises a methacrylic resin composition (MR), and the methacrylic resin composition (MR) is a methacrylic resin (PM), an SMA resin (S), and if necessary, one or more kinds. Other polymers can be included.
The other polymer is not particularly limited, and other thermoplastic resins such as polyolefins such as polyethylene and polypropylene, polyamide, polyphenylene sulfide, polyetheretherketone, polyester, polysulfone, polyphenylene oxide, polyimide, polyetherimide, and polyacetal. ; Examples include thermosetting resins such as phenol resin, melamine resin, silicone resin, and epoxy resin. The content of the other polymer in the methacrylic resin-containing layer is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

The methacrylic resin-containing layer can contain various additives, if necessary. Additives include antioxidants, heat deterioration inhibitors, UV absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes / pigments, light diffusers, and luster. Examples thereof include impact resistant modifiers such as erasers, core-shell particles and block copolymers, and phosphors. The content of the additive can be appropriately set as long as the effect of the present invention is not impaired. For example, the content of the antioxidant is 0.01 to 1 part by mass, the content of the ultraviolet absorber is 0.01 to 3 parts by mass, and the light stabilizer is 100 parts by mass with respect to 100 parts by mass of the resin constituting the methacrylic resin-containing layer. The content of the resin is preferably 0.01 to 3 parts by mass, the content of the lubricant is preferably 0.01 to 3 parts by mass, and the content of the dye / pigment is preferably 0.01 to 3 parts by mass.

When the methacrylic resin (PM) contains another polymer and / or an additive, the timing of addition may be during or after the polymerization of the methacrylic resin (PM).
When the methacrylic resin composition (MR) contains other polymers and / or additives, the timing of addition may be at the time of polymerization of the methacrylic resin (PM) and / or the SMA resin (S), or a mixture of these resins. It may be time or after mixing.

From the viewpoint of stability of heat melt molding, the melt flow rate (MFR) of the constituent resin of the methacrylic resin-containing layer is preferably 1 to 10 g / 10 minutes, more preferably 1.5 to 7 g / 10 minutes, and particularly preferably. 2-4 g / 10 minutes. Unless otherwise specified in the present specification, the MFR of the constituent resin of the methacrylic resin-containing layer is a value measured using a melt indexer at a temperature of 230 ° C. under a load of 3.8 kg.

(Polycarbonate-containing layer)
The polycarbonate-containing layer contains one or more types of polycarbonate (PC). Polycarbonate (PC) is preferably obtained by copolymerizing one or more divalent phenols with one or more carbonate precursors. The production method includes an interfacial polymerization method in which an aqueous solution of dihydric phenol and an organic solvent solution of a carbonate precursor are reacted at an interface, and a reaction between the dihydric phenol and the carbonate precursor under high temperature, reduced pressure, and solvent-free conditions. The ester exchange method and the like can be mentioned.

Examples of the divalent phenol include 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), 1,1-bis (4-hydroxyphenyl) ethane, and 1,1-bis (4-hydroxyphenyl) cyclohexane. 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfide, and bis (4-hydroxyphenyl) Hydroxyphenyl) sulfone and the like can be mentioned, with bisphenol A being preferred. Examples of the carbonate precursor include carbonyl halides such as phosgene; carbonate esters such as diphenyl carbonate; haloformates such as dihaloformates of divalent phenols; and the like.

The Mw of polycarbonate (PC) is preferably 10,000 to 100,000, more preferably 20,000 to 70,000. When Mw is 10,000 or more, the polycarbonate-containing layer is excellent in impact resistance and heat resistance, and when Mw is 100,000 or less, the polycarbonate-containing layer is excellent in moldability.

A commercially available product may be used as the polycarbonate (PC). Sumika Stylon Polycarbonate Co., Ltd. "Calibre (registered trademark)" and "SD Polyca (registered trademark)", Mitsubishi Engineering Plastics Co., Ltd. "Upiron / Novarex (registered trademark)", Idemitsu Kosan Co., Ltd. "Taflon (registered trademark)" "Trademark)" and "Panlite (registered trademark)" manufactured by Teijin Kasei Co., Ltd.

The polycarbonate-containing layer may contain one or more other polymers and / or various additives, if desired. As the other polymer and various additives, those similar to those described above in the description of the methacrylic resin-containing layer can be used. The content of the other polymer in the polycarbonate-containing layer is preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. The content of the additive can be appropriately set as long as the effect of the present invention is not impaired. With respect to 100 parts by mass of polycarbonate (PC), the content of the antioxidant is 0.01 to 1 part by mass, the content of the ultraviolet absorber is 0.01 to 3 parts by mass, and the content of the light stabilizer is 0. It is preferable that the content is 01 to 3 parts by mass, the content of the lubricant is 0.01 to 3 parts by mass, and the content of the dye / pigment is 0.01 to 3 parts by mass.
When other polymers and / or additives are added to the polycarbonate (PC), the timing of addition may be at the time of polymerization of the polycarbonate (PC) or after the polymerization.

In the present specification, the glass transition temperature of the polycarbonate-containing layer is expressed as Tg (PC). Tg (PC) is preferably 120 to 160 ° C, more preferably 135 to 155 ° C, and particularly preferably 140 to 150 ° C.
From the viewpoint of stability of heat melt molding, the MFR of the constituent resin of the polycarbonate-containing layer is preferably 1 to 30 g / 10 minutes, more preferably 3 to 20 g / 10 minutes, and particularly preferably 5 to 10 g / 10 minutes. .. In the present specification, the MFR of the constituent resin of the polycarbonate-containing layer is a value measured using a melt indexer under the conditions of a temperature of 300 ° C. and a load of 1.2 kg, unless otherwise specified.

(Linear expansion ratio (SR))
In the extruded resin plate of the present invention, the difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer and the linear expansion coefficient (S1) of the polycarbonate-containing layer. The ratio with ((S2-S1) / S1) is defined as the coefficient of linear expansion ratio (SR).
From the viewpoint of reducing warpage due to thermal change or the like, the coefficient of linear expansion ratio (SR) is −10% to + 10%, preferably −10% to + 5%, and more preferably −5% to + 2%. The coefficient of linear expansion ratio (SR) is -10% to -0.1%, -5% to -0.1%, + 0.1% to + 10%, + 0.1% to + 5%, or + 0.1%. Can be ~ + 2%. When the coefficient of linear expansion ratio (SR) is within such a range, it is easy to obtain an extruded resin plate having good surface properties and small warpage due to residual stress.

(Thickness of each layer and extruded resin plate)
The total thickness (t) of the extruded resin plate of the present invention is the same as that of a flat panel display such as a liquid crystal display, a protective plate such as a touch panel, and a protective plate and (half) mirror plate included in a mirror with a liquid crystal monitor. In applications, it is preferably 0.5 to 5.0 mm, more preferably 0.8 to 3.0 mm. If it is too thin, the rigidity may be insufficient, and if it is too thick, it may hinder the weight reduction of various electronic devices including this.
The thickness of the methacrylic resin-containing layer is not particularly limited, and is preferably 40 to 200 μm, more preferably 50 to 150 μm, and particularly preferably 60 to 100 μm. If it is too thin, the scratch resistance may be poor, and if it is too thick, the impact resistance may be poor. The thickness of the polycarbonate-containing layer is preferably 0.3 to 4.9 mm, more preferably 0.6 to 2.9 mm.

(Laminate structure)
The extruded resin plate of the present invention may have another resin layer as long as the methacrylic resin-containing layer is laminated on at least one side of the polycarbonate-containing layer. The laminated structure of the extruded resin plate contained in the extruded resin plate of the present invention includes a two-layer structure of a polycarbonate-containing layer-methacrylic resin-containing layer; a three-layer structure of a methacrylic resin-containing layer-polycarbonate-containing layer-methacrylic resin-containing layer; A three-layer structure of a resin-containing layer-a polycarbonate-containing layer-another resin layer; a three-layer structure of another resin layer-a methacrylic resin-containing layer-a polycarbonate-containing layer; and the like can be mentioned.

1 and 2 are schematic cross-sectional views of the extruded resin plates of the first and second embodiments according to the present invention. In the figure, reference numerals 16X and 16Y indicate an extruded resin plate, reference numeral 21 indicates a polycarbonate-containing layer, and reference numerals 22, 22A and 22B indicate a methacrylic resin-containing layer. The extruded resin plate 16X of the first embodiment has a two-layer structure of a polycarbonate-containing layer 21-methacryl resin-containing layer 22. The extruded resin plate 16Y of the second embodiment has a three-layer structure of a first methacrylic resin-containing layer 22A-polycarbonate-containing layer 21-2nd methacrylic resin-containing layer 22B. The structure of the extruded resin plate can be changed as appropriate.

[Laminated board]
The laminated board of the present invention can have a laminated structure in which an arbitrary film is formed on at least one surface of the extruded resin board of the present invention described above.
In one embodiment, the laminated board of the present invention can have a cured film on at least one surface of the extruded resin board of the present invention described above. The cured coating can function as a scratch resistant layer or a low reflective layer for the effect of improving visibility. The cured film can be formed by a known method (see Patent Documents 4, 5, etc. mentioned in the section of "Background Technology").
The thickness of the scratch resistant (hard coat property) cured film (scratch resistant layer) is preferably 2 to 30 μm, more preferably 5 to 20 μm. If it is too thin, the surface hardness will be insufficient, and if it is too thick, cracks may occur due to bending during the manufacturing process.
The thickness of the low-reflection cured film (low-reflection layer) is preferably 80 to 200 nm, more preferably 100 to 150 nm. If it is too thin or too thick, the low reflection performance may be insufficient.

In another embodiment, the laminated board of the present invention may have a (half) mirror film on at least one surface of the extruded resin board of the present invention described above. The laminated board having such a structure can be used as a (half) mirror board. By combining various electronic devices such as a liquid crystal monitor with a (half) mirror plate, it is possible to provide an electronic device with a mirror.
The (half) mirror film can be formed by a known method described in JP-A-9-96702. If the (half) mirror film is too thin, a sufficient mirror function may not be exhibited, and if it is too thick, it becomes difficult to manufacture. The thickness of the (half) mirror film can be designed in consideration of the mirror function and manufacturability.

[Manufacturing method of extruded resin plate]
Hereinafter, a method for producing the extruded resin plate of the present invention having the above configuration will be described. The extruded resin plate of the present invention is manufactured by a manufacturing method including coextrusion molding.
(Step (X))
The constituent resins of the polycarbonate-containing layer and the methacrylic resin-containing layer are each heated and melted, and in the state of a thermoplastic resin laminate in which the methacrylic resin-containing layer is laminated on at least one side of the polycarbonate-containing layer, from a T-die having a wide discharge port. Co-extruded in a molten state.

The molten resin for the polycarbonate-containing layer and the methacrylic resin-containing layer is preferably melt-filtered with a filter before laminating. By multi-layer molding using each molten resin that has been melt-filtered, an extruded resin plate having few defects caused by foreign matter and gel can be obtained. The filter medium of the filter is appropriately selected depending on the operating temperature, viscosity, filtration accuracy and the like. For example, non-woven fabric made of polypropylene, polyester, rayon, cotton, glass fiber, etc .; sheet-like material made of phenol resin-impregnated cellulose; metal fiber non-woven fabric sintered sheet-like material; metal powder sintered sheet-like material; wire mesh; and these. Combinations and the like can be mentioned. Above all, from the viewpoint of heat resistance and durability, a filter in which a plurality of metal fiber non-woven fabric sintered sheets are laminated is preferable. The filtration accuracy of the filter is not particularly limited, and is preferably 30 μm or less, more preferably 15 μm or less, and particularly preferably 5 μm or less.

Examples of the laminating method include a feed block method of laminating before the inflow of the T-die, a multi-manifold method of laminating inside the T-die, and the like. The multi-manifold method is preferable from the viewpoint of improving the interfacial smoothness between the layers of the extruded resin plate.

The molten thermoplastic resin laminate co-extruded from the T-die is cooled using a plurality of cooling rolls. In the present invention, three or more cooling rolls adjacent to each other are used, and a molten thermoplastic resin laminate is placed between the nth (where n ≧ 1) cooling roll and the n + 1th cooling roll. Cooling is performed by repeating the operation of sandwiching and winding around the n + 1th cooling roll a plurality of times from n = 1. For example, when three cooling rolls are used, the number of repetitions is two.

Examples of the cooling roll include a metal roll and an elastic roll having a metal outer cylinder on the outer peripheral portion (hereinafter, also referred to as a metal elastic roll). Examples of the metal roll include a drilled roll and a spiral roll, and the surface thereof may be a mirror surface or may have a pattern or unevenness. The metal elastic roll includes, for example, a shaft roll made of stainless steel or the like, a metal outer cylinder made of stainless steel or the like covering the outer peripheral surface of the shaft roll, and a fluid sealed between the shaft roll and the metal outer cylinder. It is composed of, and can exhibit elasticity due to the presence of a fluid. The thickness of the metal outer cylinder is preferably about 2 to 5 mm. The metal outer cylinder preferably has flexibility, flexibility, and the like, and preferably has a seamless structure without welded joints. A metal elastic roll provided with such a metal outer cylinder has excellent durability, and if the metal outer cylinder is mirror-finished, it can be handled in the same manner as a normal mirror-finished roll. It is easy to use because it becomes a roll that can transfer the shape if it is given.

The extruded resin plate obtained after cooling is picked up by a pick-up roll. The above coextrusion, cooling, and take-back steps are carried out continuously. In this specification, the one in a heat-melted state is mainly expressed as "thermoplastic resin laminate", and the one in a solidified state is expressed as "extruded resin plate", but there is a clear boundary between the two. Absent.

FIG. 3 shows a schematic view of a manufacturing apparatus including a T-die 11, first to third cooling rolls 12 to 14, and a pair of take-back rolls 15 as an embodiment. The thermoplastic resin laminate co-extruded from the T-die 11 is cooled by using the first to third cooling rolls 12 to 14, and is taken up by a pair of take-up rolls 15. In the illustrated example, the third cooling roll 14 is a "cooling roll on which the thermoplastic resin laminate is finally wound (hereinafter, also simply referred to as a final cooling roll)".
The fourth and subsequent cooling rolls may be installed adjacent to the subsequent stage of the third cooling roll 14. In this case, the cooling roll on which the thermoplastic resin laminate is wound last is the "last cooling roll". A transport roll can be installed between the plurality of cooling rolls adjacent to each other and the take-up roll as needed, but the transport roll is not included in the "cooling roll".
The configuration of the manufacturing apparatus can be appropriately redesigned as long as it does not deviate from the gist of the present invention.

In the production method of the present invention, the overall temperature (TX) of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll is set to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer. )) At + 15 ° C or higher. If the overall temperature (TX) of the thermoplastic resin laminate is too low with respect to Tg (PC), the shape of the second cooling roll may be transferred to the thermoplastic resin laminate, and the warpage may increase. Even if TX is Tg (PC) or more, if it is less than Tg (PC) + 15 ° C, it is cooled by the third cooling roll and then peeled off from the last cooling roll (third cooling roll in FIG. 3). The temperature of the overall temperature (TT) of the thermoplastic resin laminate at the position where it is cooled becomes lower than Tg (PC), and there is a possibility that the warp becomes large as described above.
The temperature (TX) shall be measured by the method described in the section [Example] below.

In the production method of the present invention, the overall temperature (TT) of the thermoplastic resin laminate at the position of peeling from the last cooling roll (third cooling roll in FIG. 3) is the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer. The temperature is in the range of + 5 ° C to + 19 ° C. The temperature (TT) is preferably + 7 ° C to + 17 ° C, more preferably + 9 ° C to + 15 ° C, and particularly preferably + 10 ° C to + 15 ° C with respect to (Tg (PC)).
If the temperature TT is too low with respect to Tg (PC), the shape of the final cooling roll (third cooling roll in FIG. 3) is transferred to the extruded resin plate, and the warp may increase. On the other hand, if the temperature TT is too high with respect to the glass transition temperature (Tg) of the resin layer in contact with the last cooling roll (third cooling roll in FIG. 3), the surface property of the extruded resin plate may deteriorate. The temperature (TT) shall be measured by the method described in the section [Example] below.

In the manufacturing method of the present invention, the overall temperature (TT) of the thermoplastic resin laminate at the position where it is peeled off from the last cooling roll (third cooling roll in FIG. 3) and the last cooling roll (third cooling roll in FIG. 3). The difference (TT-TM) from the overall temperature (TM) of the thermoplastic resin laminate within 1 m on the downstream side from the position where it is peeled from is set to 20 ° C. or less.
If the TT-TM is large and the extruded resin plate is rapidly cooled after peeling from the final cooling roll, the inside of the extruded resin plate may be distorted and warped. For example, when the lower surface side in extrusion molding is rapidly cooled and the lower surface side is lower than the glass transition temperature of the polycarbonate-containing layer before the upper surface side, the temperature of the resin on the upper surface side gradually decreases and gradually shrinks, so that the resin is convex downward. There is a risk of warping. When the TT-TM is 20 ° C. or lower, rapid cooling of the extruded resin plate after peeling from the last cooling roll (third cooling roll in FIG. 3) is suppressed, and the occurrence of warpage can be suppressed. The temperature (TM) shall be measured by the method described in the section [Example] below.

In the present invention, in order to obtain an extruded resin plate having a small warp, the coefficient of linear expansion ratio (SR) is set to -10% to + 10%, and the glass transition temperature (Tg (M)) of the methacrylic resin-containing layer is set to 115 ° C. or higher. It is preferable to do so.

"Letteration" is the phase difference between light in the direction of the molecular backbone and light in the direction perpendicular to it. Generally, a polymer can be obtained by heating and melting to obtain an arbitrary shape, but it is known that the molecules are oriented by the stress generated in the process of heating and cooling to generate retardation. Therefore, in order to control the retardation, it is necessary to control the orientation of the molecule. The orientation of the molecules is generated, for example, by the stress during molding near the glass transition temperature (Tg) of the polymer. In addition, in this specification, "letteration" means in-plane lettering unless otherwise specified.

The present inventors control the orientation of the molecules by optimizing the manufacturing conditions in the process of extrusion molding, whereby the Re value after molding of the extruded resin plate can be optimized, and further, the thermal change of the Re value can be achieved. It was found that it can suppress.
Although details will be described later, the extruded resin plate has a Re value of at least a part in the width direction of 50 to 330 nm both before and after heating, and the Re value of the extruded resin plate after heating is lower than that before heating. The rate is preferably less than 30%.

<Relationship between peripheral speed ratio and Re value>
In the present specification, unless otherwise specified, the "peripheral speed ratio" is the ratio of the peripheral speed of any other cooling roll or take-up roll to the second cooling roll. The peripheral speed of the second cooling roll is expressed as V2, the peripheral speed of the third cooling roll is expressed as V3, and the peripheral speed of the take-up roll is expressed as V4.
As a result of various evaluations by the present inventors regarding the relationship between the peripheral speed ratio (V3 / V2) of the third cooling roll to the second cooling roll and the Re value, the Re value is increased even if the peripheral speed ratio (V3 / V2) is increased. Was found not to increase significantly. The reason is presumed as follows.
In the production method of the present invention, the overall temperature (TT) of the thermoplastic resin laminate at the position where it is peeled off from the last cooling roll (third cooling roll in FIG. 3) is the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer. ), Adjust to the range of + 5 ° C to + 19 ° C. Here, attention is paid to the cooling process by the final cooling roll of the thermoplastic resin laminate. Since the thermoplastic resin laminate is cooled while in contact with the last cooling roll, the overall temperature of the thermoplastic resin laminate at the position where it first contacts the last cooling roll is the heat at the position where it peels off from the last cooling roll. It is higher than the overall temperature (TT) of the thermoplastic resin laminate. Therefore, the overall temperature of the thermoplastic resin laminate at the time of first contact with the final cooling roll is higher than the range of + 5 ° C to + 19 ° C with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer. For example, the temperature is about + 20 ° C. or higher with respect to the glass transition temperature (Tg (PC)). Even if the peripheral velocity ratio (V3 / V2) is increased under these conditions and a large tensile stress is applied to the extruded resin plate, it is estimated that the Re value does not increase significantly because the resin molecules are in a high temperature region where it is difficult to orient. Will be done.

As a result of various evaluations by the present inventors regarding the relationship between the peripheral speed ratio (V4 / V2) of the take-up roll to the second cooling roll and the Re value, the larger the peripheral speed ratio (V4 / V2), the higher the Re value. I understood. The reason is presumed as follows.
Under the condition that the temperature (TT) is adjusted to the range of + 5 to + 19 ° C. with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, the peripheral speed ratio of the take-up roll is increased and a large tension is applied to the extruded resin plate. When stress is applied, it is presumed that the Re value increases because the resin molecules are in the temperature range where they are likely to be oriented.

<Relationship between peripheral speed ratio and rate of decrease in Re value after heating>
It was found that when the temperature (TT) is lower than the range of + 5 to + 19 ° C. with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, the rate of decrease in the Re value after heating tends to be large. It was.

On the other hand, the peripheral speed ratio (V4 / V2) is adjusted under the condition that the temperature (TT) is in the range of + 5 ° C to + 19 ° C with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, and the Re value is adjusted. It was found that the rate of decrease in the Re value after heating did not change significantly when the temperature was adjusted to an inappropriate range.
The reason is presumed as follows. When the temperature (TT) is adjusted to the range of + 5 ° C to + 19 ° C with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, the peripheral speed ratio of the take-up roll is increased and a large tension is applied to the extruded resin plate. By applying stress, the molecules are oriented and the Re value increases, but since the heating temperature is lower than the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, it is difficult to relax the orientation of the molecules, and the Re value It is presumed that the rate of decline does not change significantly.

By controlling the temperature (TT) in the range of + 5 ° C to + 19 ° C with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, and adjusting the peripheral velocity ratio (V4 / V2) within a suitable range. , Re value and the rate of decrease of Re value after heating were found to be controllable.
Specifically, in the production method of the present invention, the peripheral speed ratio (V4 / V2) is 0.98 or more and less than 1.0. When the peripheral speed ratio (V4 / V2) is 1.0 or more, the Re value may exceed 330 nm. If the peripheral speed ratio (V4 / V2) is less than 0.98, Re may be less than 50 nm. From the viewpoint of optimizing the Re value, the peripheral speed ratio (V4 / V2) is more preferably 0.985 to 0.995.

<In-plane retardation value (Re) and warpage amount>
The Re value of the extruded resin plate is not particularly limited. For applications such as flat panel displays such as liquid crystal displays, protective plates such as touch panels, and protective plates and (half) mirror plates included in mirrors with liquid crystal monitors, when the Re value exceeds 330 nm, polarizing filters such as polarized sunglasses are used. When viewed through, the difference in transmittance of each wavelength in the visible light range becomes large, and there is a risk that various colors will be visible and visibility will deteriorate.If the Re value is less than 50 nm, all wavelengths in the visible light range will be displayed. There is a risk that the transmittance will decrease and the visibility will decrease. From the viewpoint of visibility, Re is preferably 50 to 330 nm. Within this range, the larger the value, the brighter the brightness, and the smaller the value, the clearer the color tends to be. From the viewpoint of brightness and color balance, the Re value is more preferably 80 to 250 nm. At least a part of Re in the width direction may be preferably 50 to 330 nm, more preferably 80 to 250 nm.
In a general extruded resin plate, when it is exposed to a high temperature in a manufacturing process or a usage environment, the Re value may decrease due to heat and may be out of the desired range. It is preferable that the thermal change of the Re value is small.

When used as a protective plate for flat panel displays such as liquid crystal displays and touch panels, and as a protective plate and (half) mirror plate included in mirrors with liquid crystal monitors, there is little distortion of the displayed image or reflected image. Since the extruded resin plate is excellent in visibility, it is preferable that the extruded resin plate has a small amount of warpage. Specifically, in the extruded resin plate, the amount of warpage measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding is preferably 0 to ± 0.2 mm, more preferably 0 to ± 0.2 mm. Is 0 to ± 0.15 mm.
When a general extruded resin plate is exposed to a high temperature in a manufacturing process or a usage environment, the warp becomes large due to heat, which may be out of the desired range. It is preferable that the thermal change in the amount of warpage is small.

The heating conditions for evaluating the rate of decrease in the Re value of the extruded resin plate and the amount of warpage can be a constant temperature within the range of 75 to 125 ° C. and a constant time within the range of 1 to 30 hours. For example, the evaluation can be carried out under the conditions of 75 ° C. for 5 hours or 125 ° C. for 5 hours. For example, the evaluation can be carried out by heating the test piece in an oven controlled at 125 ° C. ± 3 ° C. or 75 ° C. ± 3 ° C. for 5 hours. The above heating conditions are general heating temperatures in the process of forming a hardened film capable of functioning as a scratch resistant layer or a low-reflection layer for improving visibility, a (half) mirror film, and the like. And time is taken into consideration. Therefore, it is preferable that the Re value and the amount of warpage can be maintained in a suitable range when the heating under the above conditions is carried out and evaluated.

Specifically, when the extruded resin plate is heated at a temperature of 75 to 125 ° C. for 1 to 30 hours, the extruded resin plate preferably has at least a partial in-plane Re value in the width direction both before and after heating. It is 50 to 330 nm, more preferably 80 to 250 nm, and the rate of decrease in the Re value of the extruded resin plate after heating with respect to before heating is preferably less than 30%, more preferably less than 20%, and particularly preferably less than 15%. ..
When the extruded resin plate is heated at a temperature of 75 to 125 ° C. for 1 to 30 hours, the extruded resin plate has a rectangular shape with a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding both before and after heating. The amount of warpage measured for the test piece is preferably 0 to ± 0.2 mm, more preferably 0 to ± 0.15 mm.
The Re value and the amount of warpage shall be measured by the method described in the section [Example] below.

(Step (Y))
After the step (X), the step (Y) of heating the extruded resin plate at a temperature of 75 to 125 ° C. for 1 to 30 hours may be carried out. In this case, the Re value, the amount of warpage, and these thermal changes are effectively controlled, and the protective plate and the protective plate (half) included in a flat panel display such as a liquid crystal display, a protective plate such as a touch panel, and a mirror with a liquid crystal monitor. ) An extruded resin plate suitable as a mirror plate or the like can be obtained more stably.
In both before and after the step (Y), at least a part of the Re value in the width direction of the extruded resin plate is preferably 50 to 330 nm, more preferably 80 to 250 nm, and the step (Y) before the step (Y). ) The rate of decrease in the Re value of the extruded resin plate after that is preferably less than 30%, more preferably less than 15%. Further, in both before and after the step (Y), the amount of warpage of the extruded resin plate is preferably 0 to ± 0 measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding. It is .2 mm, more preferably 0 to ± 0.15 mm.

The extruded resin plate of the present invention is suitable as a flat panel display such as a liquid crystal display, a protective plate such as a touch panel, and a protective plate and (half) mirror plate included in a mirror with a liquid crystal monitor or the like.
Since the extruded resin plate of the present invention has a methacrylic resin-containing layer laminated on at least one side of the polycarbonate-containing layer, it is excellent in gloss, scratch resistance, and impact resistance.
According to the present invention, the in-plane retardation value (Re) is within a range suitable for a flat panel display such as a liquid crystal display and a protective plate for a touch panel, etc. It is possible to provide an extruded resin plate having less warpage and good surface properties and a method for producing the extruded resin plate.
Since the extruded resin plate of the present invention causes less warpage due to heating and has a small thermal change in Re value, it can function as a scratch-resistant layer or a low-reflection layer for improving visibility. (Half) It withstands heating and high temperature use environment in the process of forming a mirror film, etc., and is excellent in productivity and durability.
Since the extruded resin plate of the present invention causes less warpage due to heating and has a small thermal change in the Re value, it is included in a flat panel display such as a liquid crystal display, a protective plate such as a touch panel, and a mirror with a liquid crystal monitor. When used as a plate / half mirror plate or the like, there is little distortion of the displayed image or the reflected image, and the visibility is excellent.

[Use]
The extruded resin plate of the present invention can be used for ATMs of financial institutions such as banks, vending machines, mobile phones (including smartphones), personal digital assistants (PDAs) such as tablet personal computers, digital audio players, portable game machines, and copies. It is suitable as a protective plate for flat panel displays such as liquid crystal displays and touch panels used for machines, fax machines, car navigation systems, heat control panels, panels for various in-vehicle operation monitors, and E-cockpits.
The laminated plate including the extruded resin plate and the (half) mirror film of the present invention is an in-vehicle electronic mirror with various liquid crystal monitors such as a room mirror with a liquid crystal monitor, a rearview mirror with a liquid crystal monitor, and a side mirror with a liquid crystal monitor; A protective plate used for displays, liquid crystal holograms, single-lens reflex digital cameras, smartphones, game consoles, and electronic devices with smart mirrors that combine various electronic devices such as head-mounted displays (HMDs) with (half) mirror plates. Suitable as a (half) mirror plate.

Examples and comparative examples according to the present invention will be described.
[Evaluation items and evaluation methods]
The evaluation items and evaluation methods are as follows.
(Copolymerization composition of SMA resin)
^{The copolymer composition of the SMA resin was determined by the 13} C-NMR method by the following procedure using a nuclear magnetic resonance apparatus (“GX-270” manufactured by JEOL Ltd.).
A sample solution was prepared by dissolving 1.5 g of SMA resin in 1.5 ml of deuterated chloroform, and ¹³ C-NMR spectrum was measured under the condition of integration number of 4000 to 5000 times in a room temperature environment, and the following values were obtained. I asked.
-[Integrated strength of carbon peaks (around 127, 134, 143 ppm) of the benzene ring (6 carbon atoms) in the styrene unit] / 6
-[Integral strength of carbon peak (around 170 ppm) of carbonyl moiety (carbon number 2) in maleic anhydride unit] / 2
-[Integrated strength of carbon peak (around 175 ppm) of carbonyl site (carbon number 1) in MMA unit] / 1
From the area ratio of the above values, the molar ratio of styrene unit, maleic anhydride unit, and MMA unit in the sample was determined. From the obtained molar ratio and the mass ratio of each monomer unit (styrene unit: maleic anhydride unit: MMA unit = 104: 98: 100), the mass composition of each monomer unit in the SMA resin was determined. ..

(Weight average molecular weight (Mw))
The Mw of the resin was determined by the GPC method according to the following procedure. Tetrahydrofuran was used as the eluent, and two "TSKgel SuperMultipore HZM-M" manufactured by Tosoh Corporation and "SuperHZ4000" were connected in series as the column. As the GPC apparatus, HLC-8320 (product number) manufactured by Tosoh Corporation equipped with a differential refractive index detector (RI detector) was used. A sample solution was prepared by dissolving 4 mg of the resin in 5 ml of tetrahydrofuran. The temperature of the column oven was set to 40 ° C., 20 μl of the sample solution was injected at an eluent flow rate of 0.35 ml / min, and the chromatogram was measured. Ten standard polystyrenes having a molecular weight in the range of 400 to 5,000,000 were measured by GPC, and a calibration curve showing the relationship between the retention time and the molecular weight was prepared. Mw was determined based on this calibration curve.

(Glass transition temperature (Tg) of each layer)
The glass transition temperature (Tg) of each layer was measured by putting 10 mg of the constituent resin (composition) in an aluminum pan and using a differential scanning calorimeter (“DSC-50”, manufactured by Rigaku Co., Ltd.). After performing nitrogen substitution for 30 minutes or more, the temperature was once raised from 25 ° C. to 200 ° C. at a rate of 20 ° C./min in a nitrogen stream of 10 ml / min, held for 10 minutes, and cooled to 25 ° C. (primary scanning). ). Next, the temperature was raised to 200 ° C. at a rate of 10 ° C./min (secondary scanning), and the glass transition temperature (Tg) was calculated by the midpoint method from the results obtained by the secondary scanning. When a plurality of Tg data can be obtained in a resin composition containing two or more kinds of resins, the value derived from the resin as the main component was adopted as the Tg data.

(Linear expansion coefficient and linear expansion rate ratio of each layer)
The coefficient of linear expansion is defined as the rate of change in length per unit temperature change. The coefficient of linear expansion of each layer was measured according to JIS K7197 using a thermomechanical analyzer (“TMA4000”, manufactured by Bruker AXS Co., Ltd.). That is, for each layer, a press-molded resin plate having the same composition was obtained, and a square columnar sample having a size of 5 mm × 5 mm and a height of 10 mm was cut out using a diamond saw to form a smooth end face. The obtained sample was placed on a quartz plate so that a surface of 5 mm × 5 mm was in contact with the quartz plate, and a cylindrical rod was placed on the quartz plate, and a compression load of 5 g was applied to fix the sample. Then, in an air atmosphere, the temperature was raised from 25 ° C. (room temperature) to -10 ° C. of the glass transition temperature (Tg) of the sample at a heating rate of 3 ° C./min, and cooled to 25 ° C. (room temperature) (primary scanning). .. Then, the temperature was raised from 25 ° C. (room temperature) to plus 20 ° C. of the glass transition temperature (Tg) of the sample at a heating rate of 3 ° C./min (secondary scan). The coefficient of linear expansion at each temperature during this secondary scanning was measured, and the average coefficient of linear expansion in the range of 30 to 80 ° C. was determined. The coefficient of linear expansion ratio (SR) was determined from the coefficient of linear expansion of each layer.

(Amount of warpage of extruded resin plate)
From the extruded resin plate, a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding was cut out using a running saw. The obtained test piece was placed on a glass surface plate so that the upper surface in extrusion molding was the uppermost surface, and left for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%. Then, the maximum value of the gap between the test piece and the surface plate was measured using a feeler gauge, and this value was used as the initial amount of warpage. The test piece was then heated in an oven controlled at 125 ° C ± 3 ° C for 5 hours. After that, the amount of warpage was measured in the same manner as in the initial stage, and this value was taken as the amount of warpage after heating. In the test piece placed on the surface plate so that the upper surface in extrusion molding is the uppermost surface, the sign of the amount of warpage when an upwardly convex warp occurs is "plus", and a downwardly convex warp occurs. The sign of the amount of warpage in the case was defined as "minus".

(In-plane retardation value (Re) of extruded resin plate and its reduction rate)
A 100 mm square test piece was cut out from the extruded resin plate using a running saw. The test piece was heated in an oven controlled at 125 ° C. ± 3 ° C. for 5 hours. The Re value was measured before and after heating as follows. After the test piece was left in an environment of 23 ° C. ± 3 ° C. for 10 minutes or more, the Re value was measured using "WPA-100 (-L)" manufactured by Photonic Lattice Co., Ltd. The measurement point was the central part of the test piece. The rate of decrease in Re value before and after heating was calculated from the following formula.
[Re value reduction rate (%)]
= 100 × ([Re value before heating]-[Re value after heating]) / [Re value before heating]

(Surface of extruded resin plate)
Both sides of the extruded resin plate were visually observed in a room where a fluorescent lamp was installed, and the surface properties were evaluated according to the following criteria.
○ (Good): No peeling mark (so-called chatter mark) from the cooling roll is seen on the surface of the extruded resin plate.
Δ (Yes): Chatter marks can be seen on the surface of the extruded resin plate, but they are not noticeable.
× (impossible): Chatter marks are conspicuously seen on the surface of the extruded resin plate.

(Overall temperature (TT) of thermoplastic resin laminate)
The overall temperature (TT) of the thermoplastic resin laminate at the position where it was peeled off from the last cooling roll (specifically, the third cooling roll) was measured using an infrared radiation thermometer. The measurement position was the central portion in the width direction of the extruded resin plate.

(Overall temperature of thermoplastic resin laminate (TX))
The overall temperature (TX) of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll is blocked by a pair of rolls and can be directly measured using an infrared radiation thermometer. Have difficulty. Therefore, an infrared radiation thermometer is used to measure the temperature of the entire thermoplastic resin laminate immediately before passing from the second cooling roll to the third cooling roll and the temperature of the entire thermoplastic resin laminate immediately after passing through the third cooling roll. Was measured. The measurement point was the central part in the width direction of the extruded resin plate. The average value of the temperature immediately before passing through the third cooling roll and the temperature immediately after passing through was determined as TX.

(Overall temperature (TM) of thermoplastic resin laminate)
The overall temperature (TM) of the thermoplastic resin laminate at a position 1 m downstream from the position where it was peeled off from the last cooling roll (specifically, the third cooling roll) was measured using an infrared radiation thermometer. The measurement position was the central portion in the width direction of the extruded resin plate.

[material]
The materials used are as follows.
<Methyl resin (PM)>
(PM1) polymethyl methacrylate (PMMA), manufactured by Kuraray Co., Ltd., "Parapet (TM) HR" (temperature ^{230 ℃, MFR = 2.0cm 3/} 10 min under 3.8kg load).

<SMA resin>
(SMA1) According to the method described in International Publication No. 2010/013557, SMA resin (styrene-maleic anhydride-MMA copolymer, styrene unit / maleic anhydride unit / MMA unit (mass ratio) = 56 / 18/26, Mw = 150,000, Tg = 138 ° C., linear expansion rate = 6.25 × ^10-5 / K) was obtained.

<Resin composition (MR)>
The methacrylic resin (PM1) and the SMA resin (SMA1) were mixed to obtain the following four kinds of resin compositions. The SMA ratio indicates the charging ratio (mass percentage) of the SMA resin (S1) to the total amount of the methacrylic resin (PM1) and the SMA resin (S1).
(MR1) (PM1) / (S1) resin composition (SMA ratio 20% by mass, Tg = 120 ° C., coefficient of linear expansion = 7.28 × ^10-5 / K),
(MR2) (PM1) / (S1) resin composition (SMA ratio 50% by mass, Tg = 127 ° C., coefficient of linear expansion = 6.38 × ^10-5 / K),
(MR3) (PM1) / (S1) resin composition (SMA ratio 70% by mass, Tg = 132 ° C., coefficient of linear expansion = 6.15 × ^10-5 / K),
(MR4) (PM1) / (S1) resin composition (SMA ratio 80% by mass, Tg = 135 ° C., coefficient of linear expansion = 6.48 × ^10-5 / K).

<Polycarbonate (PC)>
(PC1) "SD Polyca (registered trademark) PCX" manufactured by Sumika Stylon Polycarbonate Co., Ltd. (MFR = 6.7 g / 10 minutes under a temperature of 300 ° C. and a load of 1.2 kg, Tg = 150 ° C., linear expansion coefficient = 6 .93 x ^10-5 / K).

[Example 1] (Manufacturing of extruded resin plate)
The extruded resin plate was molded using the manufacturing apparatus as shown in FIG.
Multi-manifold of methacrylic resin (PM1) melted using a 65 mmφ single-screw extruder (manufactured by Toshiba Machine Co., Ltd.) and polycarbonate (PC1) melted using a 150 mmφ single-screw extruder (manufactured by Toshiba Machine Co., Ltd.). Laminated through a mold die, and a molten thermoplastic resin laminate was co-extruded from the T-die.
Next, the molten thermoplastic resin laminate is sandwiched between the first cooling roll and the second cooling roll adjacent to each other, wound around the second cooling roll, and between the second cooling roll and the third cooling roll. It was cooled by sandwiching it in a third cooling roll and wrapping it around a third cooling roll. The extruded resin plate obtained after cooling was taken up by a pair of taking-up rolls. The polycarbonate-containing layer was brought into contact with the third cooling roll.
The overall temperature (TX) of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll is 180 ° C. by controlling the temperatures of the second cooling roll and the third cooling roll. Adjusted to. The overall temperature (TT) of the thermoplastic resin laminate at the position where the thermoplastic resin laminate is peeled off from the third cooling roll was adjusted to 162 ° C. by controlling the temperatures of the second cooling roll and the third cooling roll. .. The overall temperature (TM) of the thermoplastic resin laminate located 1 m from the position where the thermoplastic resin laminate is peeled off from the third cooling roll is 148 ° C. by controlling the cooling temperature of the transport roll located on the lower surface. Adjusted to.
The peripheral speed ratio (V4 / V2) between the take-up roll and the second cooling roll was adjusted to 0.99, and the peripheral speed ratio (V3 / V2) between the third cooling roll and the second cooling roll was adjusted to 1.00. ..
As described above, an extruded resin plate having a two-layer structure having a laminated structure of a methacrylic resin-containing layer (surface layer 1) and a polycarbonate-containing layer (surface layer 2) was obtained. The thickness of the methacrylic resin-containing layer was 0.075 mm, the thickness of the polycarbonate-containing layer was 1.925 mm, and the total thickness (t) of the extruded resin plate was 2 mm. The main production conditions and the evaluation results of the obtained extruded resin plate are shown in Table 1-1 and Table 1-2. In the following Examples and Comparative Examples, the manufacturing conditions not shown in the table were set as common conditions.

[Examples 2 to 5]
The laminated structure of the methacrylic resin-containing layer (surface layer 1) and the polycarbonate-containing layer (surface layer 2) is formed in the same manner as in Example 1 except that the composition and production conditions of the methacrylic resin-containing layer are changed as shown in Table 1-1. An extruded resin plate having a two-layer structure was obtained. The evaluation results of the extruded resin plates obtained in each example are shown in Table 1-2.

[Examples 6 to 10]
The extruded resin plate was molded using the manufacturing apparatus as shown in FIG. A multi-layered methacrylic resin (composition) melted using a 65 mmφ single-screw extruder, polycarbonate melted using a 150 mmφ single-screw extruder, and methacrylic resin (composition) melted using a 65 mmφ single-screw extruder. Laminated via a manifold type die, a molten thermoplastic resin laminate is co-extruded from the T-die, cooled using the first to third cooling rolls, and the extruded resin plate obtained after cooling is obtained. It was picked up by a pair of pick-up rolls.
As described above, an extruded resin plate having a three-layer structure having a laminated structure of a methacrylic resin-containing layer (surface layer 1) -polycarbonate-containing layer (inner layer) -methacrylic resin-containing layer (surface layer 2) was obtained. The compositions of the two methacrylic resin-containing layers were the same. The thickness of each of the two methacrylic resin-containing layers was 0.075 mm, the thickness of the polycarbonate-containing layer was 1.850 mm, and the total thickness (t) of the extruded resin plate was 2 mm. The main production conditions in each example and the evaluation results of the obtained extruded resin plate are shown in Table 1-1 and Table 1-2.

[Comparative Examples 1 to 4]
In each of Comparative Examples 1 and 2, the methacrylic resin-containing layer (surface layer 1) was obtained in the same manner as in Examples 1 to 5 except that the composition and production conditions of the methacrylic resin-containing layer were changed as shown in Table 2-1. ) -A two-layer structure extruded resin plate having a laminated structure of a polycarbonate-containing layer (surface layer 2) was obtained.
In each of Comparative Examples 3 and 4, the methacrylic resin-containing layer (surface layer 1) was obtained in the same manner as in Examples 6 to 10 except that the composition and production conditions of the methacrylic resin-containing layer were changed as shown in Table 2-1. ) -Polycarbonate-containing layer (inner layer) -A three-layer structure extruded resin plate having a laminated structure of a methacrylic resin-containing layer (surface layer 2) was obtained.
The evaluation results of the extruded resin plates obtained in each example are shown in Table 2-2.

[Summary of results]
In each of Examples 1 to 10, the total temperature (TX) of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll is set to the glass of the polycarbonate-containing layer. The overall temperature (TT) of the thermoplastic resin laminate at the position where the thermoplastic resin laminate is peeled off from the final cooling roll is set to + 15 ° C. or higher with respect to the transition temperature (Tg (PC)), and is the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer. The temperature is in the range of + 5 ° C to + 19 ° C, and the overall temperature (TT) of the thermoplastic resin laminate at the position where it is peeled off from the last cooling roll and the thermoplastic resin laminate within 1 m downstream from the position where it is peeled off from the last cooling roll. The difference (TT-TM) from the overall body temperature (TM) is 20 ° C or less, and the peripheral speed ratio (V4 / V2) between the take-up roll and the second cooling roll is 0.98 or more and less than 1.0. And said. In all of these examples, it is possible to produce an extruded resin plate having an initial Re value and a reduction rate of Re after heating within a preferable range, a small amount of warpage between the initial stage and after heating, and good surface properties. did it.

In all of Comparative Examples 1 to 4, since the TT-TM was more than 20 ° C., an extruded resin plate having a large amount of warpage after heating or a large amount of warpage at the initial stage and after heating was produced. In Comparative Example 1, since TX was less than + 15 ° C. with respect to the glass transition temperature (Tg (PC)) of the polycarbonate-containing layer, the warp was remarkably large and the rate of decrease in Re after heating was also large.

[Example 11] (Example of manufacturing a half mirror plate)
A half mirror plate was manufactured in accordance with the method described in Example 6 of JP-A-9-96702, except that the extruded resin plate obtained in Example 9 was used instead of the polycarbonate substrate. The coating compositions (A) and (B-1) described in the above document were sequentially applied onto the methacrylic resin-containing layer of the extruded resin plate, and heat-treated at 100 ° C. for 4 hours. Since the half mirror plate obtained after the heat treatment has little warpage, there is no distortion of the reflected image, and it can be suitably used for a mirror with a liquid crystal monitor or the like.

The present invention is not limited to the above-described embodiments and examples, and the design can be appropriately changed as long as the gist of the present invention is not deviated.

This application claims priority on the basis of Japanese application Japanese Patent Application No. 2018-098845 filed on May 23, 2018, the entire disclosure of which is incorporated herein by reference.

11 T-die 12 1st cooling roll (1st cooling roll)
13 Second cooling roll (second cooling roll)
14 Third cooling roll (third cooling roll)
15 Take-up roll 16, 16X, 16Y Extruded resin plate 21 Polycarbonate-containing layer 22, 22A, 22B Methacrylic resin-containing layer

Claims (13)

A method for producing an extruded resin plate in which a layer containing a methacrylic resin is laminated on at least one surface of a layer containing polycarbonate.
A thermoplastic resin laminate in which the layer containing the methacrylic resin is laminated on at least one surface of the layer containing the polycarbonate is co-extruded from the T-die in a molten state.
Using three or more cooling rolls adjacent to each other, the molten thermoplastic resin laminate is sandwiched between the nth (where n ≧ 1) cooling roll and the n + 1th cooling roll. Cooling is performed by repeating the operation of winding on the n + 1th cooling roll multiple times from n = 1.
The step (X) of picking up the extruded resin plate obtained after cooling by a picking roll is included.
The overall temperature (TX) of the thermoplastic resin laminate when sandwiched between the second cooling roll and the third cooling roll is set to the glass transition temperature of the layer containing the polycarbonate. On the other hand, the temperature should be + 15 ° C or higher.
The overall temperature (TT) of the thermoplastic resin laminate at the position where it is finally peeled off from the cooling roll is set in the range of + 5 ° C. to + 19 ° C. with respect to the glass transition temperature of the layer containing the polycarbonate.
The overall temperature (TT) of the thermoplastic resin laminate at the position of peeling from the last cooling roll and the overall temperature (TM) of the thermoplastic resin laminate within 1 m downstream from the position of peeling from the last cooling roll. The difference from (TT-TM) is set to 20 ° C or less.
The extruded resin plate having a peripheral speed ratio (V4 / V2) of the peripheral speed (V4) of the take-up roll and the peripheral speed (V2) of the second cooling roll set to 0.98 or more and less than 1.0. Production method. The glass transition temperature of the layer containing the methacrylic resin is 115 ° C. or higher.
The difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer and the linear expansion coefficient (S1) of the polycarbonate-containing layer. The method for producing an extruded resin plate according to claim 1, wherein the ratio ((S2-S1) / S1) to () is −10% to + 10%. The layer containing the methacrylic resin contains 5 to 80% by mass of the methacrylic resin and 95 to 20% by mass of a copolymer containing a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride. , The method for producing an extruded resin plate according to claim 1 or 2. The copolymer contains 50 to 84% by mass of a structural unit derived from the aromatic vinyl compound, 15 to 49% by mass of a structural unit derived from maleic anhydride, and 1 to 35% by mass of a structural unit derived from a methacrylic acid ester. The method for producing an extruded resin plate according to claim 3, which comprises. After the step (X), the extruded resin plate further includes a step (Y) of heating the extruded resin plate at a temperature of 75 to 125 ° C. for 1 to 30 hours.
Both before and after heating, the extruded resin plate has a warp amount of 0 to ± 0.2 mm measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding. Item 8. The method for producing an extruded resin plate according to any one of Items 1 to 4. After the step (X), the extruded resin plate further includes a step (Y) of heating the extruded resin plate at a temperature of 75 to 125 ° C. for 1 to 30 hours.
Both before and after heating, the extruded resin plate has at least a partial in-plane retardation value in the width direction of 50 to 330 nm, and the rate of decrease of the retardation value of the extruded resin plate after heating with respect to before heating. The method for producing an extruded resin plate according to any one of claims 1 to 5, wherein the amount is less than 30%. An extruded resin plate in which a layer containing a methacrylic resin is laminated on at least one side of a layer containing polycarbonate.
The glass transition temperature of the layer containing the methacrylic resin is 115 ° C. or higher.
Warpage measured for rectangular test pieces with a width direction of 200 mm during extrusion and a flow direction of 100 mm during extrusion before and after heating at a constant temperature within the range of 75 to 125 ° C. for 5 hours. The amount is 0 to ± 0.2 mm,
At least some in-plane retardation values in the width direction are 50-330 nm.
The rate of decrease of the retardation value after heating with respect to that before heating is less than 30%.
The difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer and the linear expansion coefficient (S1) of the polycarbonate-containing layer. ) To ((S2-S1) / S1) is -10% to + 10%, an extruded resin plate. When the extruded resin plate was heated at a temperature of 75 ° C. or 125 ° C. for 5 hours, it was measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding both before and after heating. The amount of warpage is 0 to ± 0.2 mm.
At least some in-plane retardation values in the width direction are 50-330 nm.
The extruded resin plate according to claim 7, wherein the reduction rate of the retardation value after heating is less than 30% with respect to that before heating. The amount of warpage measured for a rectangular test piece having a width direction of 200 mm during extrusion molding and a flow direction of 100 mm during extrusion molding before and after heating is 0 to ± 0.15 mm, according to claim 7 or 8. Extruded resin plate. The extruded resin plate according to any one of claims 7 to 9, wherein at least a partial in-plane retardation value in the width direction is 80 to 250 nm both before and after heating. The extruded resin plate according to any one of claims 7 to 10, wherein the reduction rate of the retardation value after heating is less than 15% with respect to that before heating. A laminated board comprising the extruded resin plate according to any one of claims 7 to 11 and a scratch-resistant layer formed on at least one surface of the extruded resin plate. A laminated board comprising the extruded resin plate according to any one of claims 7 to 11 and a mirror film or a half mirror film formed on at least one surface of the extruded resin plate.

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