JP2024008420A - Uniaxially oriented sheet and application for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an uniaxially oriented sheet with high retardation and suppressed angular blurring of a slow phase axis, which can be used as transparent substrate materials or protective materials; a front protective panel for a touch panel, a front panel for a car navigation system, a front protective panel for a speedometer, a front panel and a protective panel of a polarizer for OA equipment or portable electronic equipment, including the uniaxially oriented sheet; and a manufacturing method for the uniaxially oriented sheet.

SOLUTION: In an uniaxially oriented sheet having a layer containing polycarbonate resin, a retardation value is 3000 nm or more, and a slow phase axis is -4° or more and 4° or less when a flow direction (MD direction) is 0°.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a uniaxially stretched sheet, a front plate for a touch panel, a front plate for a car navigation system, a front plate for a speedometer, a front plate for office automation equipment or a portable electronic device, and a polarizing plate. Regarding the protection plate.
The present invention also relates to a method for manufacturing a uniaxially stretched sheet.

Polycarbonate resin has excellent impact resistance. Therefore, sheets with a layer containing polycarbonate resin (polycarbonate resin layer) have excellent transparency and impact resistance, and are the most suitable for liquid crystal display devices and image display devices such as automobile parts, electronic devices, and portable information terminals. Used for surface displays.

When a sheet having a polycarbonate resin layer is used as the outermost display of a liquid crystal display device or an image display device, the arrangement angle of the liquid crystal display device or image display device and the slow axis of the sheet is important.
In Patent Document 1, by arranging the absorption axis of the polarizing plate disposed on the output surface of the liquid crystal panel so that the slow axis of the sheet forms an angle of 45±10 degrees, the display can be improved even when using polarized sunglasses. A liquid crystal display device with a visible screen has been reported.
Further, Patent Document 2 reports an image display device that can improve image quality by arranging the image display panel and the sheet so that their slow axes are perpendicular to each other.

Japanese Patent Application Publication No. 2014-016590 JP2014-016588A

In recent years, images displayed on liquid crystal display devices and image display devices have become increasingly high-definition, and the quality required for display images has also become extremely high. Additionally, liquid crystal display devices and image display devices are becoming larger. For this reason, it has become necessary to further suppress the angular deviation of the slow axis of a sheet having a polycarbonate resin layer as an outermost display.

In view of the above-mentioned prior art, the present invention provides a uniaxially stretched sheet with high retardation and suppressed angular deviation of the slow axis, which can be used for transparent substrate materials and protective materials, and a touch panel front protection plate including the uniaxially stretched sheet. , a front plate for a car navigation system, a speedometer front protection plate, a front plate for OA equipment or a portable electronic device, a protection plate for a polarizing plate, and a method for producing a uniaxially stretched sheet. .

Based on the above problem, the above problem was solved by the following means.
<1> Has a layer containing polycarbonate resin,
The retardation value is 3000 nm or more,
A uniaxially stretched sheet whose slow axis is -4° or more and 4° or less when the flow direction (MD direction) is 0°.
<2> The uniaxially stretched sheet according to <1>, which has a layer containing a high hardness resin on at least one surface of the layer containing the polycarbonate resin.
<3> The uniaxially stretched sheet according to <1> or <2>, wherein the retardation value is 3000 nm or more and less than 10000 nm.
<4> The uniaxially stretched sheet according to any one of <1> to <3>, wherein the uniaxially stretched sheet has an overall thickness of 0.3 mm to 3.0 mm.
<5> The uniaxially stretched sheet according to any one of <1> to <3>, wherein the uniaxially stretched sheet has an overall thickness of 0.6 mm to 3.0 mm.
<6> The uniaxially stretched sheet according to any one of <1> to <5>, wherein the uniaxially stretched sheet has a width of 100 mm to 2000 mm.
<7> One or more of anti-fingerprint treatment, anti-reflection treatment, anti-glare treatment, weather resistance treatment, antistatic treatment, and antifouling treatment is applied to one or both sides of the uniaxially stretched sheet, <1 The uniaxially stretched sheet according to any one of > to <6>.
<8> A touch panel front protection plate comprising the uniaxially stretched sheet according to any one of <1> to <7>.
<9> A front plate for a car navigation system, comprising the uniaxially stretched sheet according to any one of <1> to <7>.
<10> A speedometer front protection plate comprising the uniaxially stretched sheet according to any one of <1> to <7>.
<11> A front plate for OA equipment or portable electronic equipment, comprising the uniaxially stretched sheet according to any one of <1> to <7>.
<12> A protective plate for a polarizing plate comprising the uniaxially stretched sheet according to any one of <1> to <7>.
<13> At least extruding a composition containing a polycarbonate resin into a sheet shape, passing it between a rear cooling roll and a pinch roll, and stretching it,
The method for producing a uniaxially stretched sheet according to any one of <1> to <7>, which comprises heating the sheet-like composition immediately after passing through the latter cooling roll.
<14> The method for producing a uniaxially stretched sheet according to <13>, wherein the speed ratio of the latter cooling roll and the pinch roll (pinch roll/later cooling roll) is 1.0 to 2.0.

According to the present invention, a uniaxially stretched sheet with high retardation and suppressed angular deviation of the slow axis that can be used for transparent substrate materials and protective materials, a touch panel front protection plate, a front plate for a car navigation system, including the uniaxially stretched sheet, It is now possible to provide a speedometer front protection plate, a front plate for OA equipment or portable electronic equipment, a polarizing plate protection plate, and a method for producing a uniaxially stretched sheet.

FIG. 1 is a schematic diagram showing an example of a manufacturing apparatus for a uniaxially stretched sheet of the present invention. FIG. 2 is a diagram showing the angles of the slow axes of the sheet (K-1) of Example 1 and the sheet (L-1) of Comparative Example 1. FIG. 3 is a diagram showing the angles of the slow axes of the sheet (K-2) of Example 2 and the sheet (L-2) of Comparative Example 2. FIG. 4 is a diagram showing the retardation values of the sheet (K-1) of Example 1 and the sheet (L-1) of Comparative Example 1. FIG. 5 is a diagram showing the retardation values of the sheet of Example 2 (K-2) and the sheet of Comparative Example 2 (L-2).

EMBODIMENT OF THE INVENTION Hereinafter, the form for carrying out the present invention (hereinafter simply referred to as "the present invention") will be described in detail. In addition, the following invention is an illustration for demonstrating this invention, and this invention is not limited only to this invention.
In addition, in this specification, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.
In this specification, various physical property values and characteristic values are assumed to be at 23° C. unless otherwise stated.
In the description of a group (atomic group) in this specification, the description that does not indicate substituted or unsubstituted includes a group having a substituent (atomic group) as well as a group having no substituent (atomic group). For example, the term "alkyl group" includes not only an alkyl group without a substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In this specification, for expressions that do not indicate substitution or non-substitution, non-substitution is preferred.
In this specification, "(meth)acrylic" represents both or either acrylic and methacryl.
The term "sheet" as used herein refers to a generally flat molded article that is thin relative to its length and width, and also includes films. Moreover, the "film" and "sheet" in this specification may be a single layer or a multilayer. Furthermore, the term "multilayer body" as used herein is meant to include one in the form of a film or sheet.
If the measurement methods, etc. explained in the standards shown in this specification differ from year to year, unless otherwise stated, they shall be based on the standards as of January 1, 2022.

The uniaxially stretched sheet of the present invention has a layer containing a polycarbonate resin, has a retardation value of 3000 nm or more, and has a slow axis of -4° or more and 4° or less when the flow direction (MD direction) is 0°. characterized by something.
The details of the present invention will be explained below.

<Layer containing polycarbonate resin>
The uniaxially stretched sheet of the present invention includes a layer containing a polycarbonate resin (herein sometimes simply referred to as a "polycarbonate resin layer"). The polycarbonate resin layer is usually a polycarbonate resin containing polycarbonate resin as a main component. Here, "containing polycarbonate resin as a main component" means, for example, that the content of polycarbonate resin in the polycarbonate resin layer exceeds 50% by mass. The polycarbonate resin layer preferably contains polycarbonate resin in a proportion of 75% by mass or more, more preferably contains polycarbonate resin in a proportion of 90% by mass or more, and contains polycarbonate resin in a proportion of 95% by mass or more. It is more preferable that the resin contains polycarbonate resin in a proportion of 97% by mass or more, and even more preferably that it consists essentially of polycarbonate resin.

The polycarbonate resin used in the present invention contains carbonate ester bonds in the molecular main chain. That is, -[O-R-OCO]- units (wherein R is an aliphatic group, an aromatic group, or contains both an aliphatic group and an aromatic group, and also has a linear structure or a branched structure) It is particularly preferable to use a polycarbonate resin containing a structural unit represented by formula (1), although it is not particularly limited as long as it contains a structural unit represented by formula (1). It is possible to use a polycarbonate resin containing 80% by mass or more (preferably 85% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, even more preferably 97% by mass or more) of units based on the total structural units. More preferred. By using such a polycarbonate resin, a uniaxially stretched sheet with excellent impact resistance can be obtained.
Formula (1)

As a specific example of the polycarbonate resin, aromatic polycarbonate resins (eg, Iupilon S-2000, Iupilon S-1000, Iupilon E-2000, commercially available from Mitsubishi Engineering Plastics Corporation), etc. can be used.

The glass transition temperature of the polycarbonate resin used in the present invention is preferably 120°C or higher, more preferably 125°C or higher, particularly preferably 130°C or higher, and 160°C or lower. The temperature is preferably 155°C or lower, more preferably 150°C or lower, and particularly preferably 150°C or lower.
The glass transition temperature is measured according to the method described in the Examples below.

（式（２）中、Ｒ_１は、炭素数８～３６のアルキル基、または、炭素数８～３６のアルケニル基を表し、Ｒ_２～Ｒ_５は、それぞれ独立に、水素原子、ハロゲン原子、または、置換基を有してもよい炭素数１～２０のアルキル基、または、炭素数６～１２のアリール基を表し、前記置換基は、ハロゲン原子、炭素数１～２０のアルキル基、または、炭素数６～１２のアリール基である。） Further, in recent years, there has been an increasing demand for bending the front plate, so it is also preferable to synthesize the polycarbonate resin by using it as a terminal stopper represented by formula (2).
Formula (2)

(In formula (2), R ₁ represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms, and R ₂ to R ₅ each independently represent a hydrogen atom, a halogen atom, Alternatively, it represents an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 12 carbon atoms, which may have a substituent, and the substituent is a halogen atom, an alkyl group having 1 to 20 carbon atoms, or , is an aryl group having 6 to 12 carbon atoms.)

（式（３）中、Ｒ_１は、炭素数８～３６のアルキル基、または、炭素数８～３６のアルケニル基を表す。） It is more preferable that formula (2) is expressed by formula (3).
Formula (3)

(In formula (3), R ₁ represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms.)

The number of carbon atoms in R ₁ in formula (2) or formula (3) is preferably 30 or less, more preferably 22 or less, particularly preferably 18 or less, and preferably 10 or more, more preferably 12 or more.

Among the terminal capping agents represented by formula (2) or formula (3), either or both of para-hydroxybenzoic acid hexadecyl ester and para-hydroxybenzoic acid 2-hexyldecyl ester can be used as the terminal capping agent. Particularly preferred.

For example, when a monohydric phenol (terminal stopper) having an alkyl group having 16 carbon atoms is used as R ₁ in formula (2) or formula (3), the glass transition temperature, melt fluidity, moldability, draw resistance It has excellent down properties and solubility of monohydric phenol in solvents during polycarbonate resin production, and is particularly preferred as a terminal capping agent for use in the polycarbonate resin used in the present invention.

On the other hand, by setting the number of carbon atoms in R ₁ in formula (2) or formula (3) below the above upper limit, the solubility of monohydric phenol (terminal capping agent) in organic solvents tends to improve, and the Productivity during manufacturing tends to improve.
For example, if the number of carbon atoms in R ₁ is 36 or less, productivity is high and economical efficiency is also good in producing polycarbonate resin. When the number of carbon atoms in R ₁ is 22 or less, the monohydric phenol has particularly excellent solubility in organic solvents, and the productivity can be extremely high in producing polycarbonate resin, and the economic efficiency can also be improved.
When the number of carbon atoms in R ₁ in formula (2) or formula (3) is equal to or higher than the lower limit, the glass transition temperature of the polycarbonate resin can be set to a desired low temperature, and thermoformability tends to be further improved. .

Other resins that may be included in the polycarbonate resin layer include polyester resins. The polyester resin only needs to contain terephthalic acid as a main component as a dicarboxylic acid component, and may contain dicarboxylic acid components other than terephthalic acid. For example, it is formed by polycondensation of a glycol component containing 20 to 40 (mole ratio, total 100) of 1,4-cyclohexanedimethanol to 80 to 60 (mole ratio) of ethylene glycol as the main component and a dicarboxylic acid component. Polyester resin, so-called "PETG" is preferred. Further, the polycarbonate resin may include a polyester carbonate resin having an ester bond and a carbonate bond in the polymer skeleton.

In the present invention, the weight average molecular weight of the polycarbonate resin affects the impact resistance and molding conditions of the uniaxially stretched sheet. The weight average molecular weight of the polycarbonate resin is preferably 15,000 or more, more preferably 20,000 or more, even more preferably 25,000 or more, and preferably 75,000 or less, more preferably 70,000 or less, 65, 000 or less is more preferable.
By setting it above the lower limit, the impact resistance of the uniaxially stretched sheet tends to improve. Further, by setting the temperature to the above upper limit or less, an excessive heat source is not required when laminating the polycarbonate resin layer with other layers, which is more preferable. In addition, some molding methods require high temperatures, which exposes polycarbonate resin to high temperatures, which can have a negative effect on its thermal stability. can be effectively avoided.

The weight average molecular weight of the polycarbonate resin can be measured based on the description in paragraphs 0061 to 0064 of JP-A No. 2007-179018. Details of the measurement method are shown below.

After performing measurements using polystyrene (PS) as a standard polymer, the relationship between the elution time and the molecular weight of polycarbonate (PC) is determined by a universal calibration method and used as a calibration curve. Then, the PC elution curve (chromatogram) is measured under the same conditions as the calibration curve, and each average molecular weight is determined from the elution time (molecular weight) and the peak area (number of molecules) at that elution time. When the number of molecules of molecular weight Mi is set to Ni, the weight average molecular weight is expressed as follows. The following conversion formula was used.
(Weight average molecular weight)
Mw=Σ(NiMi ² )/Σ(NiMi)
(conversion formula)
MPC=0.47822MPS ^1.01470
Note that MPC indicates the molecular weight of PC, and MPS indicates the molecular weight of PS.

The method for producing the polycarbonate resin used in the present invention can be appropriately selected depending on the monomers used, such as the known phosgene method (interfacial polymerization method) or transesterification method (melt method).

The thickness of the polycarbonate resin layer in the present invention is preferably 200 μm or more, more preferably 300 μm or more, even more preferably 600 μm or more, even more preferably 800 m or more, and even more preferably 900 μm or more. It is even more preferable. By setting the retardation value to the above lower limit or more, the load on the apparatus can be reduced when producing a uniaxially stretched sheet having a retardation value of 3000 nm or more. Further, the thickness of the polycarbonate resin layer in the present invention is preferably 2980 μm or less, more preferably 2600 μm or less, even more preferably 2100 μm or less, even more preferably 1600 μm or less, and 1000 μm or less. It is even more preferable that By setting it below the upper limit value, the load during cutting and processing can be reduced.
In the uniaxially stretched sheet of the present invention, the polycarbonate resin layer may be one layer or two or more layers (for example, 2 to 4 layers), but preferably one layer. When the uniaxially stretched sheet of the present invention has two or more polycarbonate resin layers, the thickness of each layer may be the same or different.

<Retardation value>
The retardation value of the uniaxially stretched film of the present invention is 3000 nm or more.
In the present invention, by uniaxially stretching the polycarbonate resin layer, the polymer can be oriented and the retardation value can be increased. Further, the stretching direction is the direction of the slow axis of the uniaxially stretched sheet. By increasing the retardation value, appearance defects such as rainbow unevenness can be effectively suppressed when the uniaxially stretched sheet of the present invention is used as a transparent substrate material or transparent protective material. The lower limit of the retardation value is preferably 4000 nm or more, more preferably 5000 nm or more, and even more preferably 5500 nm or more. Further, the lower limit of the retardation value is preferably less than 10,000 nm, more preferably less than 9,000 nm, and even more preferably less than 8,000 nm. By setting it below the above upper limit, the load on the molding machine during thick sheet molding can be reduced, and adverse effects on the molding machine can be effectively suppressed. Such high retardation values are achieved, for example, by stretching the sheet.
The retardation value is measured according to the description in the Examples below.

As described later, the uniaxially stretched film of the present invention may have a single polycarbonate resin layer, or may have a layer containing another resin. Layers containing resins other than the polycarbonate resin layer (for example, a high-hardness resin layer to be described later) are less likely to affect retardation. Therefore, if the retardation value of the polycarbonate resin layer is adjusted to a desired value, the retardation value of the uniaxially stretched film of the present invention is also adjusted to a desired value.

<Angle of slow axis with respect to flow direction>
The uniaxially stretched film of the present invention has a slow axis of −4° or more and 4° or less when the machine direction (MD direction) is 0°.
If the angular deviation of the slow axis is large, when used as a transparent substrate material or transparent protective material, there may be a problem of coloration when viewed through sunglasses. The angle deviation of the slow axis is preferably -3.5° or more, and 3.5° or less when the flow direction (MD direction) during uniaxial stretching is 0°. It is preferable that
The angle of the slow axis with respect to the flow direction is measured according to the description in the Examples below.

As described later, the uniaxially stretched film of the present invention may have a single polycarbonate resin layer, or may have a layer containing another resin. As described above, layers containing resins other than the polycarbonate resin layer (for example, the high-hardness resin layer described later) do not easily affect the optical axis. Therefore, if the optical axis of the polycarbonate resin layer is adjusted, the optical axis of the uniaxially stretched film of the present invention can also be adjusted as desired.
In the present invention, as a method for setting the slow axis to -4° or more and 4° or less when the flow direction (MD direction) is 0°, for example, the sheet-like composition is This is accomplished by heating things. More specifically, the sheet-like composition does not easily solidify when the film is heated immediately after it leaves the roll for stretching, and as a result, the optical axis is straight or close to it. After this point, solidification can begin.
In particular, the present invention is advantageous in that even if the film is thick with an overall thickness of 0.6 mm or more, the slow axis can be set to -4° or more and 4° or less when the flow direction (MD direction) is 0°. It is.

<Other layers>
The uniaxially stretched sheet of the present invention may be composed only of a polycarbonate resin layer, or may include a layer containing a resin other than the polycarbonate resin layer (herein sometimes referred to as "other layer"). You may do so.
The uniaxially stretched sheet of the present invention preferably has a layer containing a thermoplastic resin (B) other than the polycarbonate resin on at least one surface of the polycarbonate resin layer.
The uniaxially stretched sheet of the present invention has a layer containing a high hardness resin as a thermoplastic resin (B) on at least one surface of the polycarbonate resin layer (herein sometimes referred to as a "high hardness resin layer"). It is more preferable to have the following.
The uniaxially stretched sheet of the present invention preferably has a polycarbonate resin layer and a high hardness resin layer provided on the surface thereof.

That is, the thermoplastic resin (B) used in the present invention mainly contains a high hardness resin. In this specification, the term "high hardness resin" refers to a resin having a higher hardness than a polycarbonate resin serving as a base material, and means, for example, a resin having a pencil hardness of HB or higher. The pencil hardness of the high hardness resin is preferably HB to 5H, more preferably H to 5H.
The high hardness resins used in the present invention may be one type or two or more types. The high hardness resin is preferably at least one selected from resins (B1) to (B7) shown below.

<<Resin (B1)>>
The resin (B1) includes a vinyl copolymer (C) and a styrene copolymer (D), which will be described later. Each component will be explained below.

<<<Vinyl copolymer (C)>>>
The vinyl copolymer (C) contained in the resin (B1) contains a (meth)acrylic acid ester monomer unit (c1) represented by the formula (4) and an aliphatic vinyl represented by the formula (5). The vinyl copolymer (C) contains a monomer unit (c2), and the total proportion of the (meth)acrylic acid ester monomer unit (c1) and the aliphatic vinyl monomer unit (c2) is The ratio of the (meth)acrylic acid ester monomer unit (c1) is 90 to 100 mol% relative to the total of all monomer units in the vinyl copolymer (C). The proportion of the aliphatic vinyl monomer unit (c2) is 60 to 80 mol% based on the total of the vinyl copolymer (C), and the proportion of the aliphatic vinyl monomer unit (c2) is 40 to 80 mol% based on the total of all monomeric units in the vinyl copolymer (C). It is characterized by a content of ~20 mol%.

（式（４）中、Ｒ_１は水素原子またはメチル基であり、Ｒ_２は炭素数１～１８のアルキル基である。） Formula (4)

(In formula (4), R ₁ is a hydrogen atom or a methyl group, and R ₂ is an alkyl group having 1 to 18 carbon atoms.)

（式（５）中、Ｒ_３は水素原子またはメチル基を表し、Ｒ_４は炭素数１～４の炭化水素基を置換基を有していてもよいシクロヘキシル基を表す。） Formula (5)

(In formula (5), R ₃ represents a hydrogen atom or a methyl group, and R ₄ represents a cyclohexyl group optionally having a substituent with a hydrocarbon group having 1 to 4 carbon atoms.)

In the (meth)acrylic acid ester monomer unit (c1) represented by formula (4), R ₂ is an alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 1 to 12 carbon atoms, Specific examples include methyl group, ethyl group, butyl group, lauryl group, stearyl group, cyclohexyl group, and isobornyl group. Among the (meth)acrylic ester monomer units (c1), preferred are (meth)acrylic ester monomer units in which R ₂ is a methyl group and/or ethyl group, and more preferred is a R ₁ is a methyl group, and R ₂ is a methyl methacrylate monomer unit.

In the aliphatic vinyl monomer unit (c2) represented by formula (5), R ₃ is a hydrogen atom or a methyl group, and R ₄ has a cyclohexyl group or a hydrocarbon substituent having 1 to 4 carbon atoms. Examples include those that are cyclohexyl groups. Among the aliphatic vinyl monomer units (c2), preferred are aliphatic vinyl monomer units in which R ₃ is a hydrogen atom and R ₄ is a cyclohexyl group.

The vinyl copolymer (C) used in the present invention mainly consists of a (meth)acrylic acid ester monomer unit (c1) represented by formula (4) and an aliphatic vinyl monomer unit represented by formula (5). It consists of a body unit (c2). The vinyl copolymer (C) may contain one or more of the (meth)acrylate monomer units (c1), and may contain one or more of the aliphatic vinyl monomer units (c2). It may contain one species or two or more species. The total proportion of the (meth)acrylic acid ester monomer unit (c1) and the aliphatic vinyl monomer unit (c2) is based on the total of all monomer units in the vinyl copolymer (C). The amount is 90 to 100 mol%, preferably 95 to 100 mol%, and more preferably 98 to 100 mol%. That is, the vinyl copolymer (C) contains the (meth)acrylic acid ester monomer unit (c1) and the aliphatic vinyl monomer unit in an amount of 10 mol% or less based on the total of all monomer units. It may contain monomer units other than the mer unit (c2).
Examples of monomer units other than the (meth)acrylic ester monomer unit (c1) and the aliphatic vinyl monomer unit (c2) include (meth)acrylic ester monomers and aromatic vinyl monomers. In the vinyl copolymer (C) obtained by hydrogenating the aromatic double bonds derived from the aromatic vinyl monomer after polymerizing the Examples include quantitative units. Further, the ratio of the (meth)acrylic acid ester monomer unit (c1) represented by formula (4) is 60 to 80% relative to the total of all monomer units in the vinyl copolymer (C). The proportion of the aliphatic vinyl monomer unit (c2) represented by the formula (5) is mol%, preferably 70 to 80 mol%, based on the total monomer unit (c2) in the vinyl copolymer (C). The amount is 40 to 20 mol%, preferably 30 to 20 mol%, based on the total amount of mer units. By setting the ratio of the (meth)acrylic acid ester monomer unit (c1) to the total of all monomer units in the vinyl copolymer (C) to 60 mol% or more, the adhesion with the polycarbonate resin layer can be improved. Surface hardness tends to improve. Further, by setting the content to 80 mol% or less, it tends to be possible to effectively suppress warping of the uniaxially stretched sheet due to water absorption. Furthermore, by setting the proportion of aliphatic vinyl monomer units (c2) to the total of all monomer units in the vinyl copolymer (C) to 20 mol% or more, the glass transition temperature tends to increase. , the heat-resistant dimensional stability tends to improve. On the other hand, when the content is 40 mol% or less, solvent resistance tends to improve.

The method for producing the vinyl copolymer (C) is not particularly limited, but after polymerizing at least one type of (meth)acrylic acid ester monomer and at least one type of aromatic vinyl monomer, Those obtained by hydrogenating group double bonds are preferred. Note that (meth)acrylic acid refers to methacrylic acid and/or acrylic acid. Specific examples of the aromatic vinyl monomer used in this case include styrene, α-methylstyrene, p-hydroxystyrene, alkoxystyrene, chlorostyrene, and derivatives thereof. Among these, styrene is preferred.

For polymerization of the (meth)acrylic acid ester monomer and the aromatic vinyl monomer, a known method can be used, and for example, it can be produced by a bulk polymerization method, a solution polymerization method, or the like. The bulk polymerization method is carried out by continuously supplying a monomer composition containing the above-mentioned monomers and a polymerization initiator to a complete mixing tank, and carrying out continuous polymerization at 100 to 180°C. The monomer composition may contain a chain transfer agent if necessary.

The polymerization initiator is not particularly limited, but includes t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, 1,1-di(t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-hexylpropoxyisopropyl monocarbonate, t-amylperoxynormal Organic peroxides such as octoate, t-butylperoxyisopropyl monocarbonate, di-t-butyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile) ), 2,2'-azobis(2,4-dimethylvaleronitrile), and other azo compounds. These can be used alone or in combination of two or more.

A chain transfer agent is used as necessary, and examples thereof include α-methylstyrene dimer.

Examples of solvents used in the solution polymerization method include hydrocarbon solvents such as toluene, xylene, cyclohexane, and methylcyclohexane, ester solvents such as ethyl acetate and methyl isobutyrate, ketone solvents such as acetone and methyl ethyl ketone, tetrahydrofuran, Examples include ether solvents such as dioxane, and alcohol solvents such as methanol and isopropanol.

The solvent used in the hydrogenation reaction after polymerizing the (meth)acrylic acid ester monomer and the aromatic vinyl monomer may be the same as or different from the polymerization solvent described above. For example, hydrocarbon solvents such as cyclohexane and methylcyclohexane, ester solvents such as ethyl acetate and methyl isobutyrate, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as tetrahydrofuran and dioxane, and alcohol solvents such as methanol and isopropanol. Examples include solvents.

After polymerizing the (meth)acrylic acid ester monomer and the aromatic vinyl monomer as described above, the vinyl copolymer used in the present invention is produced by hydrogenating the aromatic double bonds derived from the aromatic vinyl monomer. (C) is obtained. The hydrogenation method is not particularly limited, and any known method can be used. For example, it can be carried out in a batch system or a continuous flow system at a hydrogen pressure of 3 to 30 MPa and a reaction temperature of 60 to 250°C. By setting the temperature to 60°C or higher, the reaction time is not too long, and by setting the temperature to 250°C or lower, molecular chain scission and hydrogenation of ester sites are less likely to occur.

Examples of catalysts used in the hydrogenation reaction include metals such as nickel, palladium, platinum, cobalt, ruthenium, and rhodium, or oxides, salts, or complex compounds of these metals, carbon, alumina, silica, silica/alumina, and diatomaceous earth. Examples include solid catalysts supported on porous carriers such as .

The vinyl copolymer (C) is preferably one in which 70% or more of the aromatic double bonds derived from the aromatic vinyl monomer are hydrogenated. That is, the proportion of unhydrogenated aromatic double bonds in the monomer unit derived from the aromatic vinyl monomer is preferably 30% or less. When the content is 30% or less, the transparency of the vinyl copolymer (C) tends to improve. The proportion of unhydrogenated aromatic double bonds in the monomer units derived from the aromatic vinyl monomer is more preferably less than 10%, and even more preferably less than 5%.

The weight average molecular weight of the vinyl copolymer (C) is not particularly limited, but from the viewpoint of strength and moldability, it is preferably 50,000 or more, more preferably 70,000 or more, and , 400,000 or less, and more preferably 300,000 or less.
The above weight average molecular weight is a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

Other resins can be blended with the vinyl copolymer (C) within a range that does not impair transparency. Examples include methyl methacrylate-styrene copolymer resin, polymethyl methacrylate, polystyrene, polycarbonate, cycloolefin (co)polymer resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, and various elastomers. .

The glass transition temperature of the vinyl copolymer (C) is preferably in the range of 110 to 190°C, more preferably in the range of 110 to 160°C. Since the glass transition temperature is 110°C or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a heat environment or a moist heat environment, and because the glass transition temperature is 190°C or lower, it can be used as a mirror roll or a shaping roll. It has excellent processability, such as continuous heat forming using a mold, or batch heat forming using a mirror mold or shaping mold. Note that the glass transition temperature in the present invention is a temperature measured using a differential scanning calorimeter at a heating rate of 10° C./min and calculated at the intersection of the baseline and the tangent at the inflection point.

<<<Styrene copolymer (D)>>>
The styrene copolymer (D) contained in the resin (B1) is composed of a vinyl aromatic monomer unit (d1), a cyclic acid anhydride monomer unit (d2), and a methacrylic acid ester monomer unit (d3). ), and the total proportion of the vinyl aromatic monomer unit (d1), the cyclic acid anhydride monomer unit (d2), and the methacrylic acid ester monomer unit (d3) is the styrene copolymer (D ), and the proportion of the vinyl aromatic monomer unit (d1) is 90 to 100 mol% relative to the total of all monomer units in the styrene copolymer (D). The ratio of the cyclic acid anhydride monomer unit (d2) is 60 to 90 mol% based on the total of all monomer units in the styrene copolymer (D). 20 mol%, and the proportion of the methacrylic acid ester monomer unit (d3) is 0 to 20 mol% with respect to the total of all monomer units in the styrene copolymer (D). That is.

The vinyl aromatic monomer unit (d1) of the styrene copolymer (D) is not particularly limited, and any known aromatic vinyl monomer can be used; From this point of view, examples include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, and the like. Among these, styrene is particularly preferred from the viewpoint of compatibility. Two or more kinds of these aromatic vinyl monomers may be mixed.

Examples of the cyclic acid anhydride monomer unit (d2) of the styrene copolymer (D) include acid anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid, which are compatible with the acrylic resin. From this viewpoint, maleic anhydride is preferred. Two or more types of these unsaturated dicarboxylic anhydride monomers may be mixed.

Examples of the methacrylic acid ester monomer unit (d3) of the styrene copolymer (D) include acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, and (meth)acrylic ester. Examples of (meth)acrylic esters include methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate. It will be done. Among these, methyl methacrylate (MMA) is preferred from the viewpoint of compatibility with the acrylic resin. Two or more types of these acrylic compound monomers may be mixed.

In the styrene copolymer (D) used in the present invention, the vinyl aromatic monomer unit (d1), the cyclic acid anhydride monomer unit (d2), and the methacrylic acid ester monomer unit (d3) The total proportion of the monomer units in the styrene copolymer (D) is 90 to 100 mol%, preferably 95 to 100 mol%, more preferably 98 to 100 mol%. It is mole%.
That is, the styrene copolymer (D) contains the vinyl aromatic monomer unit (d1) and the cyclic acid anhydride monomer in an amount of 10 mol% or less based on the total of all monomer units. It may contain monomer units other than the unit (d2) and the methacrylic acid ester monomer unit (d3). Examples of monomer units other than the vinyl aromatic monomer unit (d1), the cyclic acid anhydride monomer unit (d2), and the methacrylic acid ester monomer unit (d3) include N-substituted Examples include maleimide monomers. Examples of the N-substituted maleimide monomer include N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-naphthylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-carboxyphenylmaleimide, Examples include N-arylmaleimides such as N-nitrophenylmaleimide and N-tribromophenylmaleimide, and N-phenylmaleimide is preferred from the viewpoint of compatibility with the acrylic resin. Two or more types of these N-substituted maleimide monomers may be mixed.

The proportion of the vinyl aromatic monomer unit (d1) is preferably 60 mol% or more, more preferably 65 mol%, based on the total of all monomer units in the styrene copolymer (D). % or more, more preferably 70 mol% or more, even more preferably 72 mol% or more, even more preferably 74 mol% or more, and preferably 90 mol% or less, more preferably It is 88 mol% or less, more preferably 86 mol% or less.
The proportion of the cyclic acid anhydride monomer unit (d2) is preferably 10 mol% or more, more preferably 12 mol% or more, based on the total of all monomer units in the styrene copolymer (D). It is mol% or more, more preferably 14 mol% or more, preferably 20 mol% or less, more preferably 18 mol% or less, and still more preferably 16 mol% or less.
The proportion of the methacrylic acid ester monomer unit (d3) is 0 to 20 mol%, preferably 0 to 15 mol%, based on the total of all monomer units in the styrene copolymer (D). and more preferably 0 to 10 mol%.
By setting the proportion of the vinyl aromatic monomer unit (d1) to the total of all monomer units in the styrene copolymer (D) to be 60 mol% or more, the combination with the vinyl copolymer (C) is achieved. Compatibility tends to improve. Furthermore, by setting the content to 90 mol% or less, heat resistance tends to improve. When the ratio of the cyclic acid anhydride monomer unit (d2) to the total of all monomer units in the styrene copolymer (D) is 10 mol% or more, heat resistance tends to improve. Further, by setting the content to 20 mol% or less, the compatibility with the vinyl copolymer (C) is improved.

The method for producing the styrene copolymer (D) is not particularly limited, but can be appropriately selected from known solution polymerization methods, bulk polymerization methods, and the like.

The weight average molecular weight of the styrene copolymer (D) is not particularly limited, but from the viewpoint of compatibility with the vinyl copolymer (C), it is preferably 50,000 or more, and preferably 70,000 or more. More preferably, it is 400,000, and more preferably 300,000 or less.
The above weight average molecular weight is a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The glass transition temperature of the styrene copolymer (D) is preferably 100°C or higher, more preferably 115°C or higher, even more preferably 125°C or higher, and even more preferably 190°C or lower. The temperature is preferably 185°C or lower, and more preferably 185°C or lower.
When the glass transition temperature is 100° C. or higher, the uniaxially stretched sheet provided by the present invention tends to be less likely to deform or crack in a heat environment or a moist heat environment. Furthermore, since the temperature is 190° C. or lower, it is excellent in processability such as continuous heat forming using a mirror-finished roll or shaping roll, or batch-type heat forming using a mirror-finished mold or a shaping mold. The glass transition temperature of the styrene copolymer (D) in the present invention is the temperature measured using a differential scanning calorimeter at a heating rate of 10° C./min and calculated by the midpoint method.

The styrene copolymer (D) is a binary copolymer containing a vinyl aromatic monomer unit (d1) and a cyclic acid anhydride monomer unit (d2), or a vinyl aromatic monomer unit It is a terpolymer containing (d1), a cyclic acid anhydride monomer unit (d2), and a methacrylic acid ester monomer unit (d3), but it may be used in combination with a vinyl copolymer (C). The uniaxially stretched sheet has higher hardness than when using only the styrene copolymer (D) and has more shape stability under high temperature and high humidity than when using only the vinyl copolymer (C). can get.

In the present invention, the mass ratio of the vinyl copolymer (C) and the styrene copolymer (D) is 100 parts by mass of the total content of the vinyl copolymer (C) and the styrene copolymer (D). Based on , the vinyl copolymer (C) is preferably 5 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 25 parts by mass or more, and 40 parts by mass or more. More preferably, the amount is 95 parts by mass or less, more preferably 85 parts by mass or less, even more preferably 75 parts by mass or less, and even more preferably 60 parts by mass or less. . By keeping the mass ratio within this range, an excellent resin (B1) that maintains transparency, has excellent warpage resistance and heat resistance even when exposed to high temperature and high humidity, has a high refractive index, and has a good appearance. becomes.

The temperature at which the vinyl copolymer (C) and the styrene copolymer (D) are alloyed is preferably in the range of 230 to 320°C, more preferably in the range of 240 to 300°C. When the alloy temperature is less than 230°C, compatibility tends to deteriorate and haze tends to increase. Further, when the temperature exceeds 320°C, the vinyl copolymer (C) and/or the styrene copolymer (D) will thermally decompose.

In the present invention, there is no particular restriction on the method for producing the resin (B1), and the necessary components are mixed in advance using a mixer such as a tumbler, Henschel mixer, or Super mixer, and then a Banbury mixer or a roll , Brabender, single-screw extruder, twin-screw extruder, pressure kneader, or other known methods such as melt-kneading can be applied.
One of the characteristics of the glass transition temperature of the resin (B1) is that it is relatively high, and it is preferably 110°C or higher, more preferably 115°C or higher, and particularly preferably 120°C or higher. Further, the temperature is preferably 185°C or lower, more preferably 160°C or lower, and particularly preferably 140°C or lower.
The glass transition temperature of the resin (B1) is relatively high and there is little difference from the glass transition temperature of the polycarbonate resin, so even if it approaches the glass transition temperature of the polycarbonate resin during hot press molding or hot bending, the resin (B1) This has the advantage that there is less problem of appearance defects in layers containing . The difference between the glass transition temperature of the polycarbonate resin and the glass transition temperature of the resin (B1) is preferably in the range of 0 to 35°C, more preferably in the range of 0 to 25°C, and is more preferably in the range of 0 to 20°C. It is particularly preferable that the range is within the range.

<Resin (B2)>
The resin (B2) contains the vinyl copolymer (C), and may be blended with other resins as long as transparency is not impaired. The mass ratio of the vinyl copolymer (C) is preferably 30 to 100 parts by mass based on a total of 100 parts by mass of the resin (B2). More preferably, the vinyl copolymer (C) is 40 to 100 parts by mass, even more preferably 90 to 100 parts by mass, and particularly preferably the vinyl copolymer (C) is 90 to 100 parts by mass. The combined amount (C) is 98 to 100 parts by mass. By keeping the mass ratio within this range, the resin (B2) becomes an excellent resin (B2) that maintains transparency, has excellent warpage resistance and heat resistance even when exposed to high temperature and high humidity, and has a good appearance.

<<Resin (B3)>>
The resin (B3) contains a methacrylic resin (E) and a styrene copolymer (F). Each component will be explained below.

<<<Methacrylic resin (E)>>>
The methacrylic resin (E) contained in the resin (B3) includes a structural unit derived from a methacrylic acid ester monomer.

The methacrylic acid ester monomer of the methacrylic resin (E) includes methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, Alkyl methacrylates such as pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate; 1-methylcyclopentyl methacrylate, cyclohexyl methacrylate, cyclomethacrylate Methacrylic acid cycloalkyl esters such as heptyl, cyclooctyl methacrylate, tricyclo[5.2.1.02,6]dec-8-yl methacrylate; methacrylic acid aryl esters such as phenyl methacrylate; methacrylic acid esters such as benzyl methacrylate Examples include acid aralkyl esters, and from the viewpoint of availability, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and tert-butyl methacrylate are preferred. , methyl methacrylate is most preferred.

In addition, from the viewpoint of heat resistance, the methacrylic resin (E) preferably contains 80 mol% or more, more preferably 90 mol% or more, and 95 mol% of the structural unit derived from the methacrylic acid ester monomer. % or more is more preferable. It is preferable that the methacrylic resin (E) contains 80 mol % or more of structural units derived from the methacrylic acid ester monomer because it has good compatibility with the styrene copolymer (F).

Moreover, the methacrylic resin (E) may contain a structural unit derived from a monomer other than methacrylic acid ester. Such other monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, diacrylate - Ethylhexyl, nonyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate , 3-methoxybutyl acrylate, trifluoromethyl acrylate, trifluoroethyl acrylate, pentafluoroethyl acrylate, glycidyl acrylate, allyl acrylate, phenyl acrylate, toluyl acrylate, benzyl acrylate, isobornyl acrylate, Examples include acrylic esters such as 3-dimethylaminoethyl acrylate, and from the viewpoint of availability, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, Acrylic esters such as tert-butyl acrylate are preferred, methyl acrylate and ethyl acrylate are more preferred, and methyl acrylate is most preferred. The total content of structural units derived from these other monomers in the methacrylic resin (E) is preferably 20 mol% or less, more preferably 10 mol% or less, and even more preferably 5 mol% or less.

The lower limit of the syndiotacticity (rr) of the methacrylic resin (E) is preferably 50% by mole or more, more preferably 51% by mole or more, and 52% by mole or more. It is even more preferable. When the lower limit of the content of such a structure is 50 mol% or more, excellent heat resistance can be obtained.

Here, syndiotacticity (rr) expressed as a triad (hereinafter sometimes simply referred to as "syndiotacticity (rr)") is a chain of three consecutive constituent units (triad, triad). ) has two chains (diad) that are both racemo (denoted as rr). In addition, in a chain (diad) of structural units in a polymer molecule, those having the same configuration are called meso, and those having the opposite configuration are called racemo, and are expressed as m and r, respectively.
The syndiotacticity (rr) (%) of methacrylic resin (E) was determined by measuring the ¹ H-NMR spectrum in deuterated chloroform at 30°C, and based on the spectrum, tetramethylsilane (TMS) was set to 0 ppm. Measure the area (X) of the 0.6 to 0.95 ppm region and the area (Y) of the 0.6 to 1.35 ppm region, and calculate using the formula: (X/Y) x 100. be able to.

The weight average molecular weight of the methacrylic resin (E) is determined by the ease of mixing (dispersing) with the styrene copolymer (F) and the ease of manufacturing the resin (B3). In other words, if the weight average molecular weight of the methacrylic resin (E) is too large, the difference in melt viscosity between the methacrylic resin (E) and the styrene copolymer (F) will become too large, resulting in poor mixing (dispersion) of the resin (B3). Problems such as deterioration of transparency or inability to continue stable melt-kneading may occur. On the other hand, if the weight average molecular weight of the methacrylic resin (E) is too small, the strength of the resin (B3) will decrease, which may cause problems such as a decrease in the impact resistance of the uniaxially stretched sheet. The weight average molecular weight of the methacrylic resin (E) is preferably 50,000 or more, more preferably 60,000 or more, and preferably 700,000 or less, and 500,000 or less. It is more preferable. The above weight average molecular weight is a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The glass transition temperature of the methacrylic resin (E) is preferably 100°C or higher, more preferably 105°C or higher, and even more preferably 108°C or higher. Since the glass transition temperature is 100° C. or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a thermal environment. In addition, the glass transition temperature of the methacrylic resin (E) in this specification is measured using a differential scanning calorimeter at a heating rate of 10 ° C./min, and calculated from the intersection of the baseline and the tangent at the inflection point. This is the temperature at that time.

The melt flow rate of the methacrylic resin (E) is preferably in the range of 1 to 10 g/10 minutes. The lower limit of the melt flow rate is more preferably 1.2 g/10 minutes or more, and even more preferably 1.5 g/10 minutes or more. Further, the upper limit value of the melt flow rate is more preferably 7.0 g/10 minutes or less, and even more preferably 4.0 g/10 minutes or less. When the melt flow rate is in the range of 1 to 10 g/10 minutes, the stability of hot melt molding is good. Note that the melt flow rate of the methacrylic resin (E) in this specification is a value measured using a melt indexer at a temperature of 230° C. and a load of 3.8 kg.

<<<Styrene copolymer (F)>>>
The styrene copolymer (F) contained in the resin (B3) contains a vinyl aromatic monomer unit (f1) and a cyclic acid anhydride monomer unit (f2), and the vinyl aromatic monomer unit The total proportion of (f1) and cyclic acid anhydride monomer units (f2) is 92 to 100% by mass based on the total of all monomer units in the styrene copolymer (F). That is.

The vinyl aromatic monomer unit (f1) of the styrene copolymer (F) is not particularly limited, and any known aromatic vinyl monomer can be used; From this point of view, examples include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, and the like. Among these, styrene is particularly preferred from the viewpoint of compatibility. Two or more kinds of these aromatic vinyl monomers may be mixed.

Examples of the cyclic acid anhydride monomer unit (f2) of the styrene copolymer (F) include acid anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid, which are compatible with methacrylic resin. From this viewpoint, maleic anhydride is preferred. Two or more types of these unsaturated dicarboxylic anhydride monomers may be mixed.

In the styrene copolymer (F) used in the present invention, the total proportion of the vinyl aromatic monomer unit (f1) and the cyclic acid anhydride monomer unit (f2) is the same as that of the styrene copolymer (F). The amount is 92 to 100% by weight, preferably 95 to 100% by weight, and more preferably 98 to 100% by weight based on the total of all monomer units in F).
That is, the styrene copolymer (F) contains the vinyl aromatic monomer unit (f1) and the cyclic acid anhydride monomer in an amount of 8% by mass or less based on the total of all monomer units. It may contain monomer units other than the unit (f2). Examples of monomer units other than the vinyl aromatic monomer unit (f1) and the cyclic acid anhydride monomer unit (f2) include methacrylic acid ester monomer units and N-substituted maleimide monomers. Examples include the body.
The methacrylate monomer units in the styrene copolymer (F) include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and tert methacrylate. - Methacrylic acid alkyl esters such as butyl, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate; 1-methylcyclopentyl methacrylate, cyclohexyl methacrylate, Cycloalkyl methacrylates such as cycloheptyl methacrylate, cyclooctyl methacrylate, tricyclo[5.2.1.02,6]dec-8-yl methacrylate; aryl methacrylates such as phenyl methacrylate; benzyl methacrylate Examples include methacrylic acid aralkyl esters such as methacrylic acid aralkyl esters, and methyl methacrylate is preferred from the viewpoint of compatibility with methacrylic resin. Two or more types of these methacrylic acid ester monomers may be mixed.
Examples of the N-substituted maleimide monomer in the styrene copolymer (F) include N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-naphthylmaleimide, N-hydroxyphenylmaleimide, N-methoxy Examples include N-arylmaleimides such as phenylmaleimide, N-carboxyphenylmaleimide, N-nitrophenylmaleimide, and N-tribromophenylmaleimide, and N-phenylmaleimide is preferred from the viewpoint of compatibility with methacrylic resin. Two or more types of these N-substituted maleimide monomers may be mixed.

The proportion of the vinyl aromatic monomer unit (f1) is preferably 68 parts by mass or more, more preferably 70 parts by mass or more, more preferably 74 parts by mass or more, even more preferably 76 parts by mass or more, and preferably 84 parts by mass or less, more preferably 82 parts by mass or less, and more Preferably it is 80 parts by mass or less, more preferably 79 parts by mass or less.
Since the ratio of the vinyl aromatic monomer unit (f1) to the total of all monomer units in the styrene copolymer (F) is within the above range, compatibility with the methacrylic resin (E) is improved. There is a tendency to

The weight average molecular weight of the styrene copolymer (F) is not particularly limited, but from the viewpoint of compatibility with the methacrylic resin (E), it is preferably 30,000 or more, and 40,000 or more. is more preferable, particularly preferably 50,000 or more, preferably 400,000 or less, more preferably 300,000 or less, and even more preferably 200,000 or less. The above weight average molecular weight is a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The glass transition temperature of the styrene copolymer (F) is preferably 120°C or higher, more preferably 130°C or higher, preferably 190°C or lower, and even more preferably 170°C or lower. preferable. Since the glass transition temperature is 120° C. or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a thermal environment. Moreover, since the temperature is 190° C. or lower, it is excellent in workability such as continuous heat forming using a mirror-finished roll or shaping roll, or batch-type heat forming using a mirror-finished mold or a shaping mold. In addition, the glass transition temperature of the styrene copolymer (F) in this specification is measured using a differential scanning calorimeter at a heating rate of 10°C/min, and is measured at the intersection of the baseline and the tangent at the inflection point. This is the temperature when calculated.

The melt flow rate of the styrene copolymer (F) is preferably in the range of 1 to 10 g/10 minutes, more preferably 4 g/10 minutes or more, and even more preferably 6 g/10 minutes or more. , more preferably 9 g/10 minutes or less, and even more preferably 8 g/10 minutes or less. When the melt flow rate is in the range of 1 to 10 g/10 minutes, the stability of hot melt molding is good. Note that the melt flow rate of the styrene copolymer (F) in this specification is a value measured using a melt indexer at a temperature of 230° C. and a load of 3.8 kg.

The method for producing the styrene copolymer (F) is not particularly limited, but can be appropriately selected from known solution polymerization methods, bulk polymerization methods, suspension polymerization methods, and the like.

The styrene copolymer (F) is a binary copolymer or a multicomponent copolymer containing a vinyl aromatic monomer unit (f1) and a cyclic acid anhydride monomer unit (f2). By using methacrylic resin (E) in combination, the uniaxial resin has higher hardness than when using only styrene copolymer (F) and has better thermoformability than when using only methacrylic resin (E). A stretched sheet is obtained.

In the present invention, the mass ratio of the methacrylic resin (E) and the styrene copolymer (F) is based on the total content of the methacrylic resin (E) and the styrene copolymer (F), which is 100 parts by mass. The amount of the methacrylic resin (E) is preferably 5 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, and preferably 65 parts by mass or less. , more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, and even more preferably 45 parts by mass or less. By keeping the mass ratio within this range, an excellent resin (B3) can be obtained which maintains transparency, has excellent heat resistance, has a high refractive index, and has a good appearance.

The glass transition temperature of the resin (B3) is preferably in the range of 120 to 165°C, more preferably in the range of 120 to 155°C.
Since the glass transition temperature is 120° C. or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a thermal environment. Further, since the temperature is 165° C. or lower, processability such as continuous heat forming using a mirror-finished roll or shaping roll, or batch-type heat forming using a mirror-finished mold or shaping mold is excellent. In addition, the glass transition temperature of the resin (B3) in this specification is measured using a differential scanning calorimeter at a heating rate of 10° C./min, and calculated at the intersection of the baseline and the tangent at the inflection point. temperature.

The melt flow rate of the resin (B3) is preferably 1 g/10 minutes or more, more preferably 1.5 g/10 minutes or more, even more preferably 2 g/10 minutes or more, and 10 g/10 minutes. It is preferably at most 7 g/10 minutes, more preferably at most 5 g/10 minutes, even more preferably at most 5 g/10 minutes. When the melt flow rate is in the range of 1 to 10 g/10 minutes, the stability of hot melt molding is good. Note that the melt flow rate of resin (B3) in this specification is a value measured using a melt indexer at a temperature of 230° C. and a load of 3.8 kg.

In the present invention, there is no particular restriction on the method for producing the resin (B3), and the necessary ingredients are mixed in advance using a mixer such as a tumbler, Henschel mixer, or Super mixer, and then , Brabender, single-screw extruder, twin-screw extruder, pressure kneader, or other known methods such as melt-kneading can be applied.

The glass transition temperature of the resin (B3) is relatively high and there is little difference from the glass transition temperature of the polycarbonate resin, so even if the glass transition temperature of the resin (B3) approaches the glass transition temperature of the polycarbonate resin during hot press molding or hot bending This has the advantage that there is less problem of appearance defects in layers containing . The difference between the glass transition temperature of the polycarbonate resin and the glass transition temperature of the resin (B3) is preferably in the range of 0 to 30°C, more preferably in the range of 0 to 20°C.

<<Resin (B4)>>
Resin (B4) contains methacrylic resin (E), and other resins may be blended within the range that does not impair transparency. The mass ratio of the methacrylic resin (E) is preferably 30 to 100 parts by mass based on a total of 100 parts by mass of the resin (B4). More preferably, the methacrylic resin (E) is 40 to 100 parts by mass, even more preferably 90 to 100 parts by mass, and particularly preferably, the methacrylic resin (E) is 98 to 100 parts by mass. ~100 parts by mass. By keeping the mass ratio within this range, an excellent resin (B4) that maintains transparency, has excellent hardness, and has a good appearance can be obtained.

式（７）

<<Resin (B5)>>
The resin (B5) is a copolymer containing a structural unit (G) represented by the following formula (6) and optionally a structural unit (I) represented by the formula (7). The resin (B5) may or may not contain the structural unit (I), but preferably contains it.
Formula (6)

Formula (7)

The proportion of the structural unit (G) in all the structural units of the resin (B5) is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, and preferably 70 to 100 mol%. Particularly preferred. The proportion of the structural unit (I) in all the structural units of the resin (B5) is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, and preferably 0 to 30 mol%. Particularly preferred.

The total content of the structural unit (G) and the structural unit (H) is preferably 90 to 100 mol%, more preferably 95 to 100 mol%, and particularly Preferably it is 98 to 100 mol%.

The resin (B5) may contain structural units other than the structural unit (G) and the structural unit (H). When other structural units are included, the amount thereof is preferably 10 mol% or less, more preferably 5 mol% or less, and 2 mol% or less based on the total structural units of resin (B5). It is particularly preferable.

The method for producing the resin (B5) is not particularly limited, but it can be produced by the same method as the method for producing the polycarbonate resin described above, except for using bisphenol C as a monomer.

Specific examples of the resin (B5) include Iupilon KH3410UR, KH3520UR, and KS3410UR (manufactured by Mitsubishi Engineering Plastics).

The weight average molecular weight of the resin (B5) is preferably 15,000 or more, more preferably 20,000 or more, even more preferably 25,000 or more, preferably 75,000 or less, more preferably 70,000 or less, 65, 000 or less is more preferable. The weight average molecular weight of the resin (B5) can be measured in the same manner as the method for measuring the weight average molecular weight of the polycarbonate resin described above.

The glass transition temperature of the resin (B5) is preferably 105°C or higher, more preferably 110°C or higher, and preferably 150°C or lower, more preferably 140°C or lower, It is particularly preferred that the temperature is 135°C or lower. Since the glass transition temperature is 105° C. or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a thermal environment. Moreover, since the temperature is 150° C. or lower, it is excellent in processability such as continuous heat forming using a mirror-finished roll or a forming roll, or batch-type heat forming using a mirror-finished mold or a forming mold. In addition, the glass transition temperature of the resin (B5) in this specification is measured using a differential scanning calorimeter at a heating rate of 10° C./min, and calculated at the intersection of the baseline and the tangent at the inflection point. temperature.

<<Resin (B6)>>
The resin (B6) contains 6 to 77% by mass of (meth)acrylic acid ester structural units (i1), 15 to 71% by mass of styrene structural units (i2), and 8% of unsaturated dicarboxylic acid structural units (i3). Copolymer (I) containing ~23% by mass or an alloy of copolymers (I), furthermore, a resin that is an alloy of copolymer (I) and a resin other than copolymer (I) It is. Examples of resins other than copolymer (I) include methyl methacrylate-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, polymethyl methacrylate, and copolymers of methyl methacrylate and methyl acrylate or ethyl acrylate. Examples include merging. It is also possible to use commercially available products, and specific examples include Acrypet from Mitsubishi Chemical Co., Ltd., Sumipex from Sumitomo Chemical Co., Ltd., Parapet from Kuraray Co., Ltd., and Altoglass from Arkema. When forming an alloy, it is preferable to use an alloy of resins with higher Tg in order to avoid a decrease in the Tg of the high hardness resin.

Examples of the (meth)acrylic ester monomer constituting the (meth) acrylic ester structural unit (i1) include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and methacrylate. acid, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, etc., with methyl methacrylate being particularly preferred. Two or more of these (meth)acrylic acid ester monomers may be used in combination.
The content of the (meth)acrylic acid ester structural unit (i1) is 6 to 77% by mass, preferably 20 to 70% by mass, based on the total mass of the resin (B6).

The styrene structural unit (i2) is not particularly limited, and any known styrene monomer can be used. From the viewpoint of easy availability, styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, and the like are preferred. Among these, styrene is particularly preferred from the viewpoint of compatibility. These styrene monomers may be used in combination of two or more.
The content of the styrene structural unit (i2) is preferably 15% by mass or more, more preferably 20% by mass or more, and 71% by mass or less based on the total mass of the resin (B6). The content is preferably 66% by mass or less, and more preferably 66% by mass or less.

Examples of the unsaturated dicarboxylic anhydride monomer constituting the unsaturated dicarboxylic acid structural unit (i3) include acid anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid; Maleic anhydride is preferred from the viewpoint of compatibility with. Two or more of these unsaturated dicarboxylic anhydride monomers may be used in combination.
The content of the unsaturated dicarboxylic acid structural unit (i3) is 8 to 23% by mass, preferably 10 to 23% by mass, based on the total mass of the resin (B6).

The total content of the (meth)acrylic acid ester structural unit (i1), styrene structural unit (i2), and unsaturated dicarboxylic acid structural unit (i3) is preferably 90 to 90% based on all the structural units of the resin (B6). The content is 100 mol%, more preferably 95 to 100 mol%, particularly preferably 98 to 100 mol%.
That is, the resin (B6) may contain structural units other than the above-mentioned (meth)acrylic acid ester structural unit (i1), styrene structural unit (i2), and unsaturated dicarboxylic acid structural unit (i3). The amount thereof is preferably at most 10 mol%, more preferably at most 5 mol%, particularly preferably at most 2 mol%, based on the total structural units of the resin (B6).

Other structural units include, for example, N-phenylmaleimide.
The method for producing the resin (B6) is not particularly limited, and examples include bulk polymerization and solution polymerization.

Specific examples of the resin (B6) include Regisphy R100, R200, R310 (manufactured by Denka Corporation), Delpet 980N (manufactured by Asahi Kasei Corporation), and hw55 (manufactured by Daicel Evonik).

The weight average molecular weight of the resin (B6) is not particularly limited, but is preferably 50,000 or more, more preferably 80,000 or more, and preferably 300,000 or less, 200,000 or more. ,000 or less is more preferable. The above weight average molecular weight is a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The glass transition temperature of the resin (B6) is preferably 90 to 150°C, more preferably 100 to 150°C, particularly preferably 115 to 150°C. Since the glass transition temperature is 90° C. or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a thermal environment. Moreover, since the temperature is 150° C. or lower, it is excellent in processability such as continuous heat forming using a mirror-finished roll or a forming roll, or batch-type heat forming using a mirror-finished mold or a forming mold. In addition, the glass transition temperature of the resin (B6) in this specification is measured using a differential scanning calorimeter at a heating rate of 10 ° C./min, and calculated at the intersection of the baseline and the tangent at the inflection point. temperature.

<<Resin (B7)>>
The resin (B7) contains 5 to 20% by mass of a styrene structural unit (j1), 60 to 90% by mass of a (meth)acrylic acid ester structural unit (j2), and 5% of an N-substituted maleimide structural unit (j3). It is a copolymer (J) containing ~20% by mass, or an alloy of a copolymer (J) and a resin other than the copolymer (J).

The styrene structural unit (j1) is not particularly limited and any known styrene monomer can be used, but from the viewpoint of easy availability, styrene, α-methylstyrene, o-methylstyrene, Preferred are m-methylstyrene, p-methylstyrene, t-butylstyrene, and the like. Among these, styrene is particularly preferred from the viewpoint of compatibility. The copolymer (J) may contain two or more of these styrene structural units. The content of the styrene structural unit is 5 to 20% by mass, preferably 5 to 15% by mass, and more preferably 5 to 10% by mass, based on the total mass of the resin (B7).

Examples of the (meth)acrylic acid ester structural unit (j2) include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include structural units derived from n-butyl, 2-ethylhexyl methacrylate, etc., and particularly preferred are structural units derived from methyl methacrylate. Moreover, the copolymer (J) may contain two or more types of these (meth)acrylic acid ester structural units. The content of the (meth)acrylic acid ester structural unit is 60 to 90% by mass, preferably 70 to 90% by mass, and 80 to 90% by mass based on the total mass of the resin (B7). is more preferable.

The N-substituted maleimide structural unit (j3) in the resin (B7) includes N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-naphthylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide. , N-carboxyphenylmaleimide, N-nitrophenylmaleimide, N-tribromophenylmaleimide, and other structural units derived from N-arylmaleimide. A structural unit is preferable. The copolymer (J) may contain two or more types of these N-substituted maleimide structural units. The content of the N-substituted maleimide structural unit is 5 to 20% by mass, preferably 5 to 15% by mass, and preferably 5 to 10% by mass based on the total mass of the resin (B7). More preferred.

The total content of the styrene structural unit (j1), (meth)acrylic acid ester structural unit (j2), and N-substituted maleimide structural unit (j3) is preferably 90 to 100 mol% based on the resin (B7). It is more preferably 95 to 100 mol%, particularly preferably 98 to 100 mol%.
The resin (B7) may contain structural units other than the above-mentioned structural units. When other structural units are included, the amount thereof is preferably 10 mol% or less, more preferably 5 mol% or less, and 2 mol% or less based on the total structural units of resin (B7). It is particularly preferable.

（式中、Ｒ_１は水素原子またはメチル基であり、Ｒ_２は炭素数１～１８のアルキル基である。）
式（９）

（式中、Ｒ_３は水素原子またはメチル基であり、Ｒ_４は炭素数１～４の炭化水素基で置換されていてもよいシクロヘキシル基である。） Examples of other structural units include a structural unit derived from formula (8), a structural unit derived from formula (9), and the like.
Formula (8)

(In the formula, R ₁ is a hydrogen atom or a methyl group, and R ₂ is an alkyl group having 1 to 18 carbon atoms.)
Formula (9)

(In the formula, R ₃ is a hydrogen atom or a methyl group, and R ₄ is a cyclohexyl group which may be substituted with a hydrocarbon group having 1 to 4 carbon atoms.)

The method for producing resin (B7) is not particularly limited, but it can be produced by solution polymerization, bulk polymerization, or the like.

A specific example of the resin (B7) is Delpet PM120N (manufactured by Asahi Kasei Chemical Co., Ltd.).

The weight average molecular weight of the resin (B7) is preferably 50,000 or more, more preferably 100,000 or more, preferably 250,000 or less, and more preferably 200,000 or less. preferable. The above weight average molecular weight is a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The glass transition temperature of the resin (B7) is preferably 110°C or higher, more preferably 115°C or higher, and preferably 150°C or lower, more preferably 140°C or lower, More preferably, the temperature is 135°C or lower. Since the glass transition temperature is 110° C. or higher, the uniaxially stretched sheet provided by the present invention is less likely to be deformed or cracked in a thermal environment. Moreover, since the temperature is 150° C. or lower, it is excellent in processability such as continuous heat forming using a mirror-finished roll or a forming roll, or batch-type heat forming using a mirror-finished mold or a forming mold. In addition, the glass transition temperature of the resin (B7) in this specification is measured using a differential scanning calorimeter at a heating rate of 10 ° C./min, and calculated at the intersection of the baseline and the tangent at the inflection point. temperature.

The thickness of the other layer in the present invention (preferably the thickness of the high hardness resin layer) is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and even more preferably 40 μm or more. It is more preferable that it is, and it is even more preferable that it is 50 μm or more. By setting it to the above lower limit or more, the surface hardness of the obtained uniaxially stretched sheet tends to be further improved. Further, the thickness of the other layer in the present invention (preferably the thickness of the high hardness resin layer) is preferably 250 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less, It is more preferably 120 μm or less, even more preferably 90 μm or less, and even more preferably 70 μm or less. By setting it below the above-mentioned upper limit, the impact resistance of the obtained uniaxially stretched sheet tends to be further improved.
In the uniaxially stretched sheet of the present invention, the other layer (preferably the high hardness resin layer) may be one layer, or may be two or more layers (for example, 2 to 4 layers), but preferably It is one layer. When the uniaxially stretched sheet of the present invention has two or more other layers (preferably high hardness resin layers), the thickness of each layer may be the same or different.

<Optional additives>
In the present invention, a layer containing a polycarbonate resin and/or a layer other than the layer containing a polycarbonate resin (preferably a high hardness resin layer) may contain components other than the above-mentioned main components.

For example, a layer containing a polycarbonate resin and/or other layers may be mixed with an ultraviolet absorber. If the content of the ultraviolet absorber is too large, depending on the molding method, the excess ultraviolet absorber may scatter due to high temperatures and contaminate the molding environment, causing problems. From this, the content of the ultraviolet absorber is preferably 0 to 5% by mass, more preferably 0 to 3% by mass, and even more preferably 0 to 1% by mass. Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, and 2-hydroxybenzophenone. -4-octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, etc. Benzophenone UV absorber, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-t-butylphenyl)benzotriazole, 2-(2-hydroxy-3 Benzotriazole UV absorbers such as -t-butyl-5-methylphenyl)benzotriazole, (2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, salicylic acid Benzoate UV absorbers such as phenyl, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, bis(2,2,6,6-tetramethylpiperidine-4 Hindered amine UV absorbers such as -yl) sebacate, 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2- Hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2- hydroxy-4-butoxyphenyl)1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2, 4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3, Triazine UV absorbers such as 5-triazine, 2-[2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl]ethyl methacrylate, 2-[2- (6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl]ethyl acrylate, 3-[2-(6-hydroxybenzo[1,3]dioxol-5-yl) -2H-benzotriazol-5-yl]propyl methacrylate, 3-[2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl]propyl acrylate, 4-[ 2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl]butyl methacrylate, 4-[2-(6-hydroxybenzo[1,3]dioxol-5-yl) yl)-2H-benzotriazol-5-yl]butyl acrylate, 2-[2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2 -[2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[3-{2-(6-hydroxybenzo[1,3] ]Dioxol-5-yl)-2H-benzotriazol-5-yl}propanoyloxy]ethyl methacrylate, 2-[3-{2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H -benzotriazol-5-yl}propanoyloxy]ethyl acrylate, 4-[3-{2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl}propa Noyloxy]butyl methacrylate, 4-[3-{2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl}propanoyloxy]butyl acrylate, 2-[ 3-{2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl}propanoyloxy]ethyl methacrylate, 2-[3-{2-(6-hydroxy Benzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl}propanoyloxy]ethyl acrylate, 2-(methacryloyloxy)ethyl 2-(6-hydroxybenzo[1,3]dioxole- 5-yl)-2H-benzotriazole-5-carboxylate, 2-(acryloyloxy)ethyl 2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazole-5-carboxylate, 4-(methacryloyloxy)butyl 2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazole-5-carboxylate, 4-(acryloyloxy)butyl 2-(6-hydroxybenzo Examples include sesamol type benzotriazole ultraviolet absorbers such as [1,3]dioxol-5-yl)-2H-benzotriazole-5-carboxylate. The method of mixing is not particularly limited, and methods such as a method of total compounding, a method of dry blending a masterbatch, a method of total dry blending, etc. can be used.

In the present invention, various additives may be mixed and used in the layer containing the polycarbonate resin and/or other layers in addition to the ultraviolet absorber described above. Examples of such additives include antioxidants, anti-coloring agents, antistatic agents, mold release agents, lubricants, dyes, pigments, plasticizers, flame retardants, resin modifiers, compatibilizers, organic fillers, and Examples include reinforcing materials such as inorganic fillers. The method of mixing is not particularly limited, and methods such as a method of total compounding, a method of dry blending a masterbatch, a method of total dry blending, etc. can be used.

The materials contained in the layer containing polycarbonate resin and/or other layers in the present invention, such as polycarbonate resin and thermoplastic resin (B), are preferably filtered and purified by filter treatment. By refining or laminating through a filter, a uniaxially stretched sheet with less appearance defects such as foreign matter and defects can be obtained. There are no particular restrictions on the filtration method, and melt filtration, solution filtration, or a combination thereof can be used.

There is no particular restriction on the filter to be used, and any known filter can be used, and is appropriately selected depending on the usage temperature, viscosity, filtration accuracy, etc. of each material. Filter media include, but are not limited to, polypropylene, cotton, polyester, viscose rayon, glass fiber non-woven fabrics or roving yarn rolls, phenolic resin-impregnated cellulose, metal fiber non-woven sintered bodies, metal powder sintered bodies, and breaker plates. , or a combination of these can be used. In particular, in consideration of heat resistance, durability, and pressure resistance, a type made of sintered metal fiber nonwoven fabric is preferable.

The filtration accuracy (pore diameter during filtration) is 50 μm or less, preferably 30 μm or less, and more preferably 10 μm or less for the polycarbonate resin and thermoplastic resin (B).

Regarding the filtration of polycarbonate resin and thermoplastic resin (B), it is preferable to use, for example, a polymer filter used for thermoplastic resin melt filtration. Polymer filters are classified into leaf disc filters, candle filters, pack disc filters, cylindrical filters, etc. depending on their structure, and leaf disc filters with a large effective filtration area are particularly suitable.

In the present invention, the total thickness of the polycarbonate resin layer and the high hardness resin layer is preferably 0.3 mm or more, more preferably 0.5 mm or more, even more preferably 0.7 mm or more, It is even more preferably 0.8 mm or more, more preferably 3.0 mm or less, more preferably 2.5 mm, and may be 2.0 mm or less.
Furthermore, the uniaxially stretched sheet of the present invention generally has an overall thickness of 0.04 to 3.5 mm, preferably 0.3 mm or more, more preferably 0.5 mm or more, and 0.7 mm or more. It is more preferable that it is above, it is even more preferable that it is 0.8 mm or more, it is also preferable that it is 3.0 mm or less, it is more preferable that it is 2.5 mm, and even if it is 2.0 mm or less, good.
In the uniaxially stretched sheet of the present invention, the width (TD direction) of the uniaxially stretched sheet is preferably 100 mm or more, and may be 500 mm or more, and is preferably 2000 mm or less, and may be 1500 mm or less. good.
With such thickness and/or sheet width, it becomes easier to adjust the retardation value of the uniaxially stretched sheet and the slow axis when the flow direction (MD direction) is 0° within the range of the present invention.

<Method for manufacturing uniaxially stretched sheet>
The method for producing the uniaxially stretched sheet of the present invention is not particularly limited. For example, as a method for manufacturing a sheet in which a layer containing a thermoplastic resin (B) is laminated on at least one side of a layer containing a polycarbonate resin whose main component is a polycarbonate resin, A method of laminating a layer containing thermoplastic resin (B) and a layer containing polycarbonate resin and bonding them together under heat; laminating a layer containing thermoplastic resin (B) and a layer containing polycarbonate resin that were formed separately; A method of bonding both with an adhesive, a method of co-extrusion molding a layer containing a thermoplastic resin (B) and a layer containing a polycarbonate resin, a method of co-extrusion molding a layer containing a thermoplastic resin (B) that has been formed in advance There are various methods, such as in-mold molding of a layer containing a polycarbonate resin to integrate them, but in order to achieve a retardation value of 3000 nm or more, it is necessary to stretch during or after molding. From the viewpoint of manufacturing cost and productivity, it is preferable to carry out uniaxial stretching during coextrusion molding.

As a method for co-extrusion molding, for example, a layer containing a polycarbonate resin and a layer containing a thermoplastic resin (B) are heated and melted in separate extruders, and each is extruded from a slit-shaped discharge port of a T-die to laminate them. A manufacturing method may be mentioned in which the material is then solidified in close contact with a cooling roll.
Furthermore, in the present invention, as a method for obtaining a uniaxially stretched sheet having a slow axis of −4° or more and 4° or less when the flow direction (MD direction) is 0°, a composition containing at least a polycarbonate resin is used. uniaxial stretching, comprising extruding the composition into a sheet, passing it between a rear cooling roll and a pinch roll, and stretching the composition, and heating the sheet-like composition immediately after passing through the latter cooling roll. Examples include a method for manufacturing a sheet. This method is useful in that even if the film is thick with an overall thickness of 0.6 mm or more, the slow axis can be set to -4° or more and 4° or less when the flow direction (MD direction) is 0°. . Here, immediately after means, for example, within 120 seconds, and also means that the sheet is conveyed within 3000 mm. The composition containing polycarbonate resin becomes a constituent material of the polycarbonate resin layer.

FIG. 1 is a schematic diagram showing an example of a manufacturing apparatus for a uniaxially stretched sheet of the present invention. In FIG. 1, a molten polycarbonate resin and a thermoplastic resin (B) coextruded from a die 1 are sandwiched between a first cooling roll 2 and a second cooling roll 3, and wound around the second cooling roll 3. After that, it is wound around at least one rear stage cooling roll 4. Thereafter, the sheet is reheated by the heater 5 and sent to the pinch rolls 6 to obtain a uniaxially stretched sheet with high retardation and a small slow axis when the machine direction (MD direction) is 0°.
In the embodiment shown in FIG. 1, first, a polycarbonate resin and a thermoplastic resin (B) are heated and melted using separate extruders (not shown), and then coextruded from a coextrusion die 1 to be laminated.

The temperature at which the resin is heated and melted in an extruder is preferably 80 to 150° C. higher than the glass transition temperature (Tg) of the polycarbonate resin and the thermoplastic resin (B). Generally, the temperature conditions of the main extruder for extruding polycarbonate resin are preferably 200°C or higher, more preferably 220°C or higher, and preferably 320°C or lower, and 310°C or lower. It is more preferable that it is below. Further, the temperature conditions of the sub-extruder for extruding the thermoplastic resin (B) are preferably 180°C or higher, more preferably 190°C or higher, preferably 280°C or lower, and 270°C or lower. It is more preferable that

As a method for co-extruding two types of molten resins, known methods such as a feed block method and a multi-manifold method can be employed.
For example, in the case of a feed block method, the molten resin laminated in the feed block is guided to a sheet forming die such as a T-die, and after being formed into a sheet, it flows into a forming roll (polishing roll) whose surface is mirror-treated. It is sufficient to form a bank by applying a mirror finish and cooling while passing through the forming roll.
In the case of the multi-manifold method, the molten resin laminated within the multi-manifold die may be formed into a sheet shape inside the die, and then surface-finished and cooled using forming rolls.
In any case, the temperature of the die 1 is usually set at 230 to 290°C, preferably 250 to 280°C.

Next, the sheet-like coextruded body coextruded from the die 1 is cooled and solidified by being wound around at least three cooling rolls. Specifically, the sheet-like coextrusion in a molten state is sandwiched between a first cooling roll 2 and a second cooling roll 3, wound around the second cooling roll, and then passed through at least one subsequent cooling roll 4. Wrap it around. Thereafter, the uniaxially stretched sheet (multilayer body) of the present invention can be obtained by reheating it with a heater 5 and feeding it into a pair of pinch rolls 6 arranged above and below.

As the forming (cooling) roll, there are rigid rolls and elastic rolls, and either of them may be used. In one embodiment, the cooling rolls (2, 3, 4) are rigid rolls. In order to mirror-finish the surface of the sheet-like coextruded body, the rigid roll is preferably mirror-finished.

In order to mirror-finish the surface, the polycarbonate resin is sandwiched between the first cooling roll 2 and the second cooling roll 3, and after being wound around the second cooling roll 3, the polycarbonate resin surface is treated with at least one subsequent cooling roll 4. It is preferable to wrap around it. The temperatures of the first cooling roll 2 and the second cooling roll 3 are preferably 70°C or higher, more preferably 80°C or higher, and preferably 160°C or lower, and 150°C or lower, respectively. It is preferable that
Further, the temperature of the second stage cooling roll 4 is preferably 70°C or higher, more preferably 90°C or higher, and preferably 210°C or lower, more preferably 200°C or lower.
Regarding the roll temperatures of the first cooling roll 2, the second cooling roll 3, and the second cooling roll 4, it is preferable that the temperature difference between the first cooling roll 2 and the second cooling roll 3 is within 20°C. The temperature difference between the second cooling roll 3 and the second cooling roll 4 is preferably 50 to 100°C.
The roll speed of the first cooling roll 2, the second cooling roll 3, and the second stage cooling roll 4 is preferably 0.5 m/min or more, more preferably 0.8 m/min or more, and It is preferably 30.0 m/min or less, more preferably 6.0 m/min or less.

Examples of the heater 5 include far-infrared heaters, carbon heaters, graphite heaters, sheathed heaters, and the like, and any of them may be used. In one embodiment, the heater 5 is a far-infrared heater. The heating temperature of the heater 5 is preferably 250°C or higher, more preferably 300°C or higher, further preferably 500°C or lower, and more preferably 450°C or lower. The distance between the heater 5 and the sheet is preferably 10 mm or more, more preferably 20 mm or more, and preferably 100 mm or less, more preferably 80 mm or less. By heating again under such conditions, it is possible to suppress the angular deviation of the slow axis that occurs when the latter stage cooling roll 4 is peeled off.
The speed ratio between the post-cooling roll 4 and the pinch roll 6 (pinch roll/post-cooling roll) is preferably 1.0 or more, more preferably 1.05 or more, and preferably 1.1 or more. More preferably, it is particularly preferably 1.2 or more. Further, it is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.6 or less, and even more preferably 1.4 or less.

One or more of anti-fingerprint treatment, anti-reflection treatment, anti-glare treatment, weather resistance treatment, antistatic treatment and antifouling treatment may be applied to one or both sides of the uniaxially stretched sheet of the present invention. Methods for antireflection treatment, antifouling treatment, antistatic treatment, weather resistance treatment, and antiglare treatment are not particularly limited, and known methods can be used. Examples include a method of applying a reflection-reducing paint, a method of depositing a dielectric thin film, a method of applying an antistatic paint, and the like.

The uniaxially stretched sheet of the present invention has high retardation and suppresses angular fluctuation of the slow axis. Therefore, it is suitably used as a transparent substrate material, a transparent protective material, etc. Specifically, transparent substrate materials and transparent protective materials (for example, It is suitably used as a front plate).
More specifically, touch panel front protection plates for car navigation systems, speedometer front protection plates, front plates for office automation equipment or portable electronic devices, and protection plates for polarizing plates, including the uniaxially stretched sheet of the present invention. It is preferably used as

The present invention will be explained in more detail with reference to Examples below. The materials, usage amounts, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.
If the measuring equipment used in the examples is difficult to obtain due to discontinuation or the like, measurements can be made using other equipment with equivalent performance.

<Composition ratio of monomer units of thermoplastic resin>
It was calculated from the measured values of ¹ H-NMR and ¹³ C-NMR (400 MHz, solvent was CDCl ³ ) using JNM-AL400 manufactured by JEOL Ltd.

<Glass transition temperature>
A differential scanning calorimeter DSC6200 manufactured by Seiko Instruments Co., Ltd. was used. Under nitrogen flow of 30ml/min., 10°C/min. The temperature was raised from 30°C to 200°C at 50°C/min. The temperature was lowered from 200°C to 30°C, and then again at 10°C/min. The temperature was raised from 30°C to 200°C. The intersection of the baseline and the tangent at the inflection point in the second temperature increase was used as the glass transition temperature (unit: °C).

<Retardation value and slow axis angle>
Test specimens were cut at a pitch of 40 mm perpendicular to the flow direction (MD direction) of a 920 mm wide sheet obtained by cutting both ends of the sheet to the same width (the position of the central axis is the same before and after cutting both ends). It was cut out (test piece size: 40 mm x 50 mm). The side cut out perpendicularly to the MD direction of this test piece was set with the reference bar of RETS-100 manufactured by Otsuka Electronics Co., Ltd., and the sample was set so that the reference axis did not deviate, and the retardation value at a wavelength of 590 nm was measured. , the angle of the slow axis was measured. The angle of the slow axis is the angle of the slow axis when the MD direction is 0°.
Data on the retardation value and slow axis angle were obtained at a pitch of 40 mm in the range of -440 mm to 440 mm, with the center portion of the sheet set at 0 mm.

For Examples and Comparative Examples, the materials shown below were used as polycarbonate resins (A-1) to (A-2), methacrylic resin (E-1), and styrene copolymer (F-1). However, the invention is not limited to these materials.

<Polycarbonate resin (A-1) to (A-2), methacrylic resin (E-1), styrene copolymer (F-1)>
Polycarbonate resin (A-1): Iupilon S-1000 manufactured by Mitsubishi Engineering Plastics Co., Ltd. (weight average molecular weight: 33,000, glass transition temperature: 147°C)
Polycarbonate resin (A-2): Iupilon E-2000 manufactured by Mitsubishi Engineering Plastics Co., Ltd. (weight average molecular weight: 53,000, glass transition temperature: 151°C)
Methacrylic resin (E-1): ALTUGLAS (registered trademark) V020 manufactured by Arkema Corporation (weight average molecular weight: 127,000, glass transition temperature: 109°C, melt flow rate at 230°C and 3.8 kg load: 1. 8 g/10 min, methyl methacrylate/methyl acrylate = 96.1% by mass/3.9% by mass, refractive index 1.49, mm/mr/rr = 7.4 mol%/37.4 mol%/55 .2 mol%)
Styrene copolymer (F-1): SAM-020 manufactured by Fine-blend Polymer ((f1)/(f2) = styrene/maleic anhydride = 83% by mass/17% by mass, weight average molecular weight: 107,200, Glass transition temperature: 129℃)

Synthesis Example 1 [Production of vinyl copolymer (C-1)]
As monomer components, purified methyl methacrylate (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 75.000 mol%, purified styrene (manufactured by Wako Pure Chemical Industries, Ltd.) 24.998 mol%, and as a polymerization initiator t-amylper A monomer composition consisting of 0.002 mol% of oxy-2-ethylhexanoate (manufactured by Arkema Yoshitomi, trade name: Luperox 575) was continuously supplied at 1 kg/h to a 10 L complete mixing tank equipped with helical ribbon blades. Continuous polymerization was carried out at an average residence time of 2.5 hours and a polymerization temperature of 150°C. The liquid was continuously drawn out from the bottom of the polymerization tank so that the liquid level remained constant, and introduced into a solvent removing device to obtain a pellet-like copolymer. The proportion of (meth)acrylic acid ester monomer units (c1) derived from methyl methacrylate in the obtained copolymer was 73 mol%. Further, the weight average molecular weight (in terms of standard polystyrene) measured by gel permeation chromatography was 124,000. This copolymer was dissolved in methyl isobutyrate (manufactured by Kanto Kagaku Co., Ltd.) to prepare a 10% by mass methyl isobutyrate solution. A 1000 mL autoclave was charged with 500 parts by mass of a 10% by mass solution of this copolymer in methyl isobutyrate and 1 part by mass of 10% by mass Pd/C (manufactured by NE Chemcat) as a hydrogenation catalyst, and heated at a hydrogen pressure of 9 MPa and 200°C. The copolymer was held for 15 hours to hydrogenate the aromatic double bonds in the styrene moieties of the copolymer. The hydrogenation reaction rate of the styrene site was 99%. Furthermore, in the obtained vinyl copolymer (C-1), the proportion of structural units derived from methyl methacrylate was 73 mol%, and the vinyl copolymer (C-1) had a glass transition temperature of 115°C. .

Production example 1 [Preparation of pellets of thermoplastic resin (B-1)]
To 100 parts by mass of vinyl copolymer (C-1), 500 ppm of phosphorus additive PEP-36 (manufactured by ADEKA Co., Ltd.) and stearic acid monoglyceride (product name: H-100, manufactured by Riken Vitamin Co., Ltd.) After adding 0.2% by mass and mixing with a blender for 20 minutes, a twin-screw extruder with a screw diameter of 26 mm (manufactured by Shibaura Kikai Co., Ltd., TEM-26SS, L/D≒40) equipped with a polymer filter with an opening of 10 μm was used. The mixture was melt-kneaded at a cylinder temperature of 240° C., extruded into strands, and pelletized using a pelletizer. Pellets could be produced stably.
The thermoplastic resin (B-1) pellets had a transparent appearance, a glass transition temperature of 115° C., and a refractive index of 1.49.

Production example 2 [Preparation of pellets of thermoplastic resin (B-2)]
To a total of 100 parts by mass of 50 parts by mass of methacrylic resin (E-1) and 50 parts by mass of styrene copolymer (F-1), 500 ppm of phosphorus additive PEP-36 and 0.00 parts of stearic acid monoglyceride were added. 2% by mass was added and mixed and pelletized in the same manner as in Production Example 1. Pellets of thermoplastic resin (B-2) could be stably produced.
The thermoplastic resin (B-2) pellets had a transparent appearance, a glass transition temperature of 122° C., and a refractive index of 1.54.

Example 1 [Manufacture of sheet (K-1)]
Using a multilayer extrusion device having a single screw extruder with a shaft diameter of 50 mm, a single screw extruder with a shaft diameter of 120 mm, a feed block connected to all the extruders, and a T-die with a width of 1180 mm connected to the feed block. Then, a sheet was formed. The thermoplastic resin (B-1) obtained in Production Example 1 was continuously introduced into a single-screw extruder with a shaft diameter of 50 mm, and extruded at a cylinder temperature of 240° C. and a discharge rate of 17 kg/h. Further, polycarbonate resin (A-1) was continuously introduced into a single-screw extruder with a shaft diameter of 120 mm, and extruded at a cylinder temperature of 290° C. and a discharge rate of 291 kg/h. A feed block connected to the entire extruder was equipped with two types and two layers of distribution pins, and the thermoplastic resin (B-1) and polycarbonate resin (A-1) were introduced at a temperature of 280° C. and formed into sheets.
It is extruded into a sheet using a T-die connected to the tip of the die at a temperature of 270°C, and as shown in Figure 1, the roll temperature of the three mirror-finished rolls (2, 3, and 4 in Figure 1) is adjusted to 115°C from the upstream side. , 120°C, 185°C, and the roll speed was set to 3.08 m/min, 3.08 m/min, and 3.10 m/min from the upstream side, and cooled while transferring the mirror surface, and after peeling from the third roll, in the MD direction. A ceramic far-infrared heater [dimensions: 250 x 65 mm, heater capacity: 400 W] arranged perpendicularly to the sheet was heated to 400°C, the distance from the sheet was 60 mm, and reheated at a pinch roll speed of 4.10 m/min. It was uniaxially stretched to obtain a sheet (K-1). The obtained sheet (K-1) had a total thickness of 1000 μm at the center, a thickness of the surface layer (layer containing thermoplastic resin (B)) of 60 μm, a sheet width of 1050 mm, a retardation value of 5808 to 6807 nm, and a slow phase. The axis angle was −3.46° to 2.53°.

Example 2 [Manufacture of resin multilayer body (K-2)]
With the same equipment configuration as in Example 1, polycarbonate resin (A-2) was used instead of polycarbonate resin (A-1), and thermoplastic resin (B-2) was used instead of thermoplastic resin (B-1). The thermoplastic resin (B-2) obtained in Production Example 1 was continuously introduced into a single-screw extruder with a shaft diameter of 50 mm, and extruded at a cylinder temperature of 240° C. and a discharge rate of 10 kg/h. Further, polycarbonate resin (A-2) was continuously introduced into a single-screw extruder with a shaft diameter of 120 mm, and extruded at a cylinder temperature of 290° C. and a discharge rate of 324 kg/h. A feed block connected to the entire extruder was equipped with distribution pins of two types and two layers, and the temperature was raised to 280° C., and thermoplastic resin (B-2) and polycarbonate resin (A-2) were introduced and sheet-formed.
It is extruded into a sheet using a T-die connected to the tip of the roll with a temperature of 270°C, and the roll temperature of the three mirror-finished rolls is set to 115°C, 120°C, and 185°C from the upstream side, and the roll speed is set to 1.77 m/min from the upstream side. min, 1.77 m/min, 1.79 m/min while transferring the mirror surface, and after peeling off from the third roll, ceramic far-infrared heaters arranged perpendicular to the MD direction [dimensions: 250 x 65 mm] , heater capacity: 400 W] at 400° C., the distance from the sheet was 60 mm, and uniaxial stretching was performed at a pinch roll speed of 2.20 m/min to obtain a sheet (K-2). The obtained sheet (K-2) had a total thickness of 2000 μm at the center, a thickness of the surface layer (layer containing thermoplastic resin (B)) of 60 μm, a sheet width of 1100 mm, a retardation value of 7339 to 7939 nm, and a slow phase. The angle of the axis was -2.90 to 3.28°.

Comparative Example 1 [Manufacture of sheet (L-1)]
A sheet (L-1) of thermoplastic resin (B-1) and polycarbonate resin (A-1) was obtained in the same manner as sheet (K-1) in Example 1 except that the ceramic far-infrared heater was turned off. Ta. The overall thickness of the central part of the obtained sheet (L-1) was 1000 μm, the thickness of the surface layer (layer containing thermoplastic resin (B)) was 60 μm, the sheet width was 1050 mm, the retardation value was 5774 to 6502 nm, and the slow phase The angle of the axis was −5.11° to 4.33°.

Comparative Example 2 [Manufacture of sheet (L-2)]
A sheet (L-1) of thermoplastic resin (B-2) and polycarbonate resin (A-2) was obtained in the same manner as sheet (K-2) of Example 2, except that the ceramic far-infrared heater was turned off. Ta. The overall thickness of the central part of the obtained sheet (L-2) was 2000 μm, the thickness of the surface layer (layer containing thermoplastic resin (B)) was 60 μm, the sheet width was 1100 mm, the retardation value was 7403 to 8353 nm, and the slow phase The angle of the axis was −6.09° to 5.89°.

As described above, a sheet with high retardation and suppressed angular deviation of the slow axis can be obtained.

FIG. 2 shows the angles of the slow axes of the sheet of Example 1 (K-1) and the sheet of Comparative Example 1 (L-1). The triangular mark is the sheet of Example 1 (K-1), and the circle mark is the sheet of Comparative Example 1 (L-1).
FIG. 3 shows the angles of the slow axes of the sheet of Example 2 (K-2) and the sheet of Comparative Example 2 (L-2). The circle mark is the sheet of Example 2 (K-1), and the triangle mark is the sheet of Comparative Example 2 (L-2).

FIG. 4 shows the retardation values of the sheet of Example 1 (K-1) and the sheet of Comparative Example 1 (L-1). The triangular mark is the sheet of Example 1 (K-1), and the circle mark is the sheet of Comparative Example 1 (L-1).
FIG. 5 shows the retardation values of the sheet of Example 2 (K-2) and the sheet of Comparative Example 2 (L-2). The circle mark is the sheet of Example 2 (K-1), and the triangle mark is the sheet of Comparative Example 2 (L-2).

As shown in FIG. 2, when Example 1 and Comparative Example 1 are compared, Example 1 suppresses the angular deviation of the slow axis better. Moreover, as shown in FIG. 3, when Example 2 and Comparative Example 2 were compared, Example 2 was found to be more suppressed in angular deviation of the slow axis.
As a result of the above, a uniaxially stretched sheet with a retardation value of 3000 nm or more and a slow axis angle of -4.0° or more and 4.0° or less when the MD direction is 0° was realized.

The uniaxially stretched sheet of the present invention has high retardation and suppresses angular fluctuation of the slow axis, and the uniaxially stretched sheet can be used as a transparent substrate material or a transparent protective material. Specifically, it can be used as a front panel to protect portable display devices such as mobile phone terminals, portable electronic play equipment, personal digital assistants, mobile PCs, and installed display devices such as car navigation systems and speedometers. , can be suitably used.

1. Die 2. First cooling roll3. Second cooling roll4. Post cooling roll 5. Heater 6. pinch roll

Claims (14)

Has a layer containing polycarbonate resin,
The retardation value is 3000 nm or more,
A uniaxially stretched sheet whose slow axis is -4° or more and 4° or less when the flow direction (MD direction) is 0°. The uniaxially stretched sheet according to claim 1, further comprising a layer containing a high hardness resin on at least one surface of the layer containing the polycarbonate resin. The uniaxially stretched sheet according to claim 1, wherein the retardation value is 3000 nm or more and less than 10000 nm. The uniaxially stretched sheet according to claim 1, wherein the total thickness of the uniaxially stretched sheet is 0.3 mm to 3.0 mm. The uniaxially stretched sheet according to claim 1, wherein the total thickness of the uniaxially stretched sheet is 0.6 mm to 3.0 mm. The uniaxially stretched sheet according to claim 1, wherein the width of the uniaxially stretched sheet is 100 mm to 2000 mm. 2. The uniaxially stretched sheet is subjected to one or more of anti-fingerprint treatment, anti-reflection treatment, anti-glare treatment, weather resistance treatment, antistatic treatment, and antifouling treatment on one or both sides of the uniaxially stretched sheet. uniaxially stretched sheet. A touch panel front protection plate comprising the uniaxially stretched sheet according to any one of claims 1 to 7. A front plate for a car navigation system comprising the uniaxially stretched sheet according to any one of claims 1 to 7. A speedometer front protection plate comprising the uniaxially stretched sheet according to any one of claims 1 to 7. A front plate comprising the uniaxially stretched sheet according to any one of claims 1 to 7 and used for office automation equipment or portable electronic equipment. A protective plate for a polarizing plate comprising the uniaxially stretched sheet according to any one of claims 1 to 7. At least extruding a composition containing a polycarbonate resin into a sheet shape, passing it between a post-stage cooling roll and a pinch roll, and stretching it,
The method for producing a uniaxially stretched sheet according to any one of claims 1 to 7, comprising heating the sheet-like composition immediately after passing through the latter cooling roll. 14. The method for producing a uniaxially stretched sheet according to claim 13, wherein the speed ratio of the second cooling roll and the pinch roll (pinch roll/second cooling roll) is 1.0 to 2.0.