TWI729089B - Manufacturing method of extruded resin board and extruded resin board - Google Patents

Abstract

The present invention provides a method for manufacturing an extruded resin board and an extruded resin board, wherein the extruded resin board has good surface properties and can suppress the occurrence of warpage, and even if heated to a high temperature, the decrease rate of the in-plane hysteresis value is small.

The present invention is a method for manufacturing an extruded resin sheet, which comprises laminating a methacrylic resin-containing layer with a glass transition temperature of 115°C or higher on at least one surface of a polycarbonate-containing layer in a molten state. In the step of extruding the laminated body from the T-die, at the position where the thermoplastic resin laminated body is peeled from the last cooling roll wound, the temperature of the entire resin is set to -2 relative to the glass transition temperature of the polycarbonate-containing layer. In the range of °C to +15 °C, the peripheral speed ratio (V4/V2) of the peripheral speed (V4) of the drawing roll and the peripheral speed (V2) of the second cooling roll is set to 0.98 or more and 1.01 or less.

Description

Manufacturing method of extruded resin board and extruded resin board

The present invention relates to an extruded resin sheet. More specifically, the present invention relates to an extruded resin sheet having a layer containing methacrylic resin and a layer containing polycarbonate, and a method of manufacturing the same. The extruded resin sheet It has good surface properties and can suppress warpage caused by residual stress. It can also control the in-plane hysteresis value even in a high-temperature environment. It is also suitable for touch panel protective covers, etc.

The touch panel (or touch screen) is an electronic component that combines a display device and a position input device. It can operate electronic equipment by touching the touch panel with a finger or a pen. The touch panel is used in ATMs and vending machines of financial institutions such as banks. Digital information equipment such as computers, mobile phones, mobile information terminals (PDA), digital audio players, mobile game consoles, tablet personal computers, copiers, faxes, car navigation, etc.

In the input operation using the touch panel, the surface may be scratched or the interior may be crushed. In order to prevent this, a transparent protective cover is provided on the surface of the touch panel, mainly using a protective cover made of tempered glass. In addition, from the viewpoint of processability and weight reduction, a protective cover made of transparent resin has been developed. Such a protective cover requires gloss, scratch resistance, impact resistance, and the like.

By the way, polycarbonate is suitable for obtaining excellent impact resistance One of the resins for different molded products, methacrylic resin is one of the resins suitable for obtaining molded products with high gloss and excellent scratch resistance. In addition, by simultaneously heating and melting polycarbonate and methacrylic resin (for example, co-extrusion molding), a resin plate including a polycarbonate-containing layer and a methacrylic resin-containing layer can be produced. In the heat-melt molding of such a resin plate, a large amount of strain stress remains in the molded product obtained due to the difference in the characteristics of the two types of resins. The strain stress remaining in the molded product is called the residual stress, and the molded product with this residual stress may warp or shrink due to heat or the like.

In the plate-shaped molded product of the above-mentioned resin plate, warpage due to residual stress becomes a problem in particular. As one of the methods for reducing the residual stress in the plate-shaped molded product and suppressing the occurrence of warpage, a method for adjusting the rotation speed of a cooling roll used for extrusion molding is known (for example, refer to Patent Document 1).

In addition, in order to solve such problems, research has been conducted on the improvement of heat resistance and moisture resistance of methacrylic resin. For example, a two-layer resin board has been reported, which has methyl methacrylate units and selected from methacrylic acid units, acrylic acid units, maleic anhydride units, N-substituted or unsubstituted maleimides The unit, the glutaric anhydride structural unit, and the glutaric imine structural unit are used to form the first layer of a methacrylic resin with a glass transition temperature of 110°C or higher, and a layer containing polycarbonate is provided on the first layer ( For example, refer to Patent Document 2). However, the heat resistance and moisture resistance of the methacrylic resin of such a resin plate are still insufficient, and the above-mentioned problems cannot be sufficiently solved by this.

Also, in order to solve this problem, a known A method of reducing the difference in the coefficient of linear expansion between two resin sheets to control the occurrence of warpage (for example, refer to Patent Document 3). However, only meeting the requirement of linear expansion coefficient cannot solve the above-mentioned problems.

Regarding the above-mentioned protective cover, it has been studied to use a resin plate, which is a resin plate formed by forming a scratch-resistant (hard coat) and low-reflective hardened film on at least one side in order to improve scratch resistance and visibility. .

For example, Patent Document 4 has disclosed that a hardened film is formed on at least one surface of a methacrylic resin plate for use as a display window protection plate of a portable information terminal of a liquid crystal system.

In addition, Patent Document 5 has disclosed that a hardened film is formed on the methacrylic resin layer of a laminated plate in which a methacrylic resin layer is laminated on one surface of a polycarbonate resin layer, and the cured film is used for a liquid crystal display cover.

In addition, the above-mentioned protective cover is provided on the front side (viewer's side) of the liquid crystal display, and the viewer views the screen of the liquid crystal display through such a protective cover. However, the conventional protective cover hardly changes the emission from the liquid crystal display which is polarized light. Because of the polarization of light, if you wear polarized sunglasses to view the screen, depending on the angle formed by the polarization axis of the emitted light and the transmission axis of the polarized sunglasses, the screen may become dark or it may be difficult to view the image. Therefore, a protective cover for a liquid crystal display capable of suppressing a decrease in the visibility of an image when viewing a screen of a liquid crystal display through a polarizing filter such as polarized sunglasses has been studied.

For example, Patent Document 6 has disclosed that the in-plane hysteresis value is 85 to 300 nm.

In the step of forming a scratch-resistant (hard coat) and low-reflective cured film on the surface of the resin plate as described above, the resin plate may be heated to The temperature is around 100°C. For example, if the coating material is thermosetting, it will be heated in the step of curing the coating. In addition, if the coating material is photocurable, it will be heated with light irradiation. In addition, if the coating material contains a solvent such as an organic solvent, it will be heated for drying.

However, by exposing the resin plate to high temperatures, the hysteresis value will decrease and cannot be controlled within the expected range.

In addition, when the car navigation system or other mobile phone or smartphone is placed in the car under the sun in the summer, the LCD protection plate may be heated to a high temperature, and there will be a resin plate. The hysteresis value may be reduced.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2007-185956 A

[Patent Document 2] JP 2009-248416 A

[Patent Document 3] JP 2007-118597 A

[Patent Document 4] JP 2004-299199 A

[Patent Document 5] JP 2006-103169 A

[Patent Document 6] JP 2010-085978 A

In the extruded resin sheet, the degree of residual stress in each resin layer is different, so an attempt was made to reduce the residual stress by adjusting the rotation speed of the cooling roll used in extrusion molding. However, when the molded product is separated from the cooling roll, there will be called vibration lines on the surface of the molded product. (chatter mark) streak-shaped defects are generated, and the surface properties are degraded. This point is a problem in the use of the extruded resin sheet for a protective cover of a touch panel, and the like.

The object of the present invention is to provide a method for manufacturing an extruded resin board and an extruded resin board that has good surface properties and can suppress the occurrence of warpage, and even if heated to a high temperature, the drop rate of the in-plane hysteresis value is small.

The inventors of the present invention conducted studies to achieve the above object, and as a result, found that the present invention includes the following aspects, that is, the present invention includes the following aspects.

[1] A method of manufacturing an extruded resin sheet, which is a method of manufacturing an extruded resin sheet in which a layer containing a methacrylic resin is laminated on at least one surface of a layer containing polycarbonate, wherein the aforementioned methacrylic resin The glass transition temperature of the resin layer is 115°C or higher. The manufacturing method includes the following steps: in a molten state, laminating a thermoplastic resin containing the methacrylic resin layer on at least one surface of the polycarbonate-containing layer The laminate is extruded from a T-die, the thermoplastic resin laminate is sandwiched between the first cooling roll and the second cooling roll, and the thermoplastic resin laminate is wound to the second cooling roll and then to the third The cooling roll is used for cooling, and the thermoplastic resin laminate is pulled by the pull roll; the thermoplastic resin laminate is peeled from the last wound cooling roll on the thermoplastic resin laminate Set the temperature of the entire resin to the range of -2°C to +15°C relative to the glass transition temperature of the polycarbonate-containing layer, and set the peripheral speed (V4) of the pull roll and the second cooling The peripheral speed ratio (V4/V2) of the peripheral speed (V2) of the roller is set to 0.98 or more and 1.01 or less.

[2] The method for producing an extruded resin sheet as described in [1], wherein the difference between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer (S2-S1), the ratio ((S2-S1)/S1) to the linear expansion coefficient (S1) of the aforementioned polycarbonate-containing layer is -10% to +5%.

[3] The method for producing an extruded resin sheet as described in [1] or [2], wherein the methacrylic resin-containing layer contains 40 to 80% by mass of structural units derived from methyl methacrylate and contains The structural unit of the methacrylate represented by general formula (I) is 20-60% by mass.

(In the formula, Cy represents an alicyclic hydrocarbon group).

[4] The method for producing an extruded resin sheet as described in [3], wherein Cy in the aforementioned general formula (I) is a polycyclic aliphatic hydrocarbon group.

[5] The method for producing an extruded resin sheet according to any one of [1] or [2], wherein the aforementioned methacrylic resin-containing layer contains: methacrylic resin 5 mass% or more and less than 80 mass%, and A copolymer composed of structural units derived from an aromatic vinyl compound represented by the following general formula (II) and structural units derived from an acid anhydride represented by the following general formula (III) 20 mass %the above.

(In the formula: R ¹ and R ² each independently represent a hydrogen atom or an alkyl group).

(In the formula: R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group).

[6] The method for producing an extruded resin sheet as described in [5], wherein the copolymer contains 50 to 84% by mass of the structural unit derived from the aromatic vinyl compound, and 15 to 49% by mass of the structural unit derived from the acid anhydride And it contains 1-25% by mass of methacrylate monomer.

[7] The method for producing an extruded resin sheet as described in [6], wherein the methacrylate monomer is methyl methacrylate.

[8] An extruded resin sheet, which is an extruded resin sheet obtained by the manufacturing method of any one of [1] to [7], wherein the extruded resin sheet is heated at 75°C for 5 hours At this time, in at least a part of the width direction before and after heating, the in-plane hysteresis value is 50 to 600 nm, and the decrease rate of the hysteresis value before and after heating is less than 15%.

[9] An extruded resin sheet, which is an extruded resin sheet obtained by the manufacturing method of any one of [1] to [7], wherein the extruded resin sheet is heated at 100°C for 5 hours时，于 Heat In at least a part of the width direction before and after, the in-plane hysteresis value is 50 to 600 nm, and the decrease rate of the hysteresis value before and after the heating is less than 15%.

[10] An extruded resin sheet, which is an extruded resin sheet obtained by the manufacturing method of any one of [1] to [7], wherein the extruded resin sheet is heated at 75°C to 100°C When heating for 5 hours, in at least a part of the width direction before and after heating, the in-plane hysteresis value is 50 to 600 nm, and the reduction rate of the hysteresis value before and after heating is less than 15%.

[11] The extruded resin sheet according to any one of [8] to [10], wherein the in-plane hysteresis value is 80 to 350 nm in at least a part of the width direction before and after the heating.

[12] The extruded resin sheet according to any one of [8] to [11], wherein the reduction rate of the hysteresis value before and after the heating is less than 10%.

[13] The extruded resin board as in any one of [8] to [12], which is further provided with a scratch-resistant layer on at least one surface.

[14] A method for manufacturing an extruded resin board, which is obtained by the manufacturing method as described in any one of [1] to [7], and further comprises heating the extruded resin board at 65°C~ In the step of heating at a temperature of 110°C for 1-30 hours, the in-plane hysteresis value is 50-600nm in at least a part of the width direction before and after heating, and the decrease rate of the hysteresis value before and after heating is less than 15%.

[15] An extruded resin sheet in which a layer containing methacrylic resin is laminated on at least one surface of a layer containing polycarbonate A resin plate, in which the glass transition temperature of the aforementioned methacrylic resin-containing layer is 115°C or higher, and when heated at 75°C for 5 hours, the in-plane hysteresis value is 50~600nm in at least a part of the width direction before and after heating , The reduction rate of the hysteresis value before and after the heating is less than 15%, the difference between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer (S2) -S1), the ratio ((S2-S1)/S1) to the linear expansion coefficient (S1) of the aforementioned polycarbonate-containing layer is -10% to +5%.

The extruded resin sheet obtained by the manufacturing method of the extruded resin sheet of the present invention has good surface properties and can suppress the occurrence of warpage, and has an in-plane hysteresis value suitable as a protective sheet for liquid crystal displays when viewed through polarized sunglasses .

In addition, since the ratio of the in-plane hysteresis value decreased by heating is small, it can withstand heating steps and high-temperature environments, and its productivity and durability are excellent.

In addition, the extruded resin sheet of the present invention is suitable for applications such as touch panel protective covers seeking gloss, scratch resistance, and impact resistance, for example.

11‧‧‧T font

12‧‧‧The first cooling roll

13‧‧‧Second cooling roll

14‧‧‧The third cooling roll

15‧‧‧Pull roll

16‧‧‧Extruded resin sheet (thermoplastic resin laminate)

Fig. 1 is a diagram showing a method of manufacturing an extruded resin sheet using co-extrusion according to an embodiment of the present invention.

[The form of implementing the invention]

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In order to clarify the description, the following descriptions and drawings are appropriately omitted and simplified. The constituent elements having the same configuration or function and the corresponding parts in the various drawings are marked with the same symbols, and their descriptions are omitted.

The extruded resin sheet of the present invention is a polycarbonate-containing layer (hereinafter also appropriately referred to as "polycarbonate-containing layer") on at least one side of which a methacrylic resin-containing layer is laminated (hereinafter also appropriately Described as "methacrylic resin-containing layer").

By laminating a methacrylic resin-containing layer on a polycarbonate-containing layer, it has excellent transparency, impact resistance, and scratch resistance.

The extruded resin board is manufactured by using an extrusion molding method, and has excellent production efficiency.

In the extruded resin sheet, the lower limit of the glass transition temperature (Tg) of the methacrylic resin-containing layer is 115°C, preferably 120°C, more preferably 125°C, and still more preferably 130°C. Its glass transition temperature The upper limit of (Tg) is preferably 160°C, more preferably 155°C, and still more preferably 150°C. If the linear expansion ratio (SR) and the glass transition temperature (Tg) of the methacrylic resin-containing layer are within this range, the surface properties are good and the warpage due to residual stress is small, which is preferable.

[Methacrylic resin]

In the present invention, the methacrylic resin contains a structural unit derived from methacrylate. In the methacrylic resin, the content of the structural unit derived from methacrylate is preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and may also be 100 quality%. If the content of the structural unit derived from methacrylate is within the above range, it has good transparency.

This methacrylate is represented by general formula (IV).

In the general formula (IV), R represents a hydrocarbon group. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

The hydrocarbon group represented by R may be an acyclic aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group such as a phenyl group. Here, when R is an alicyclic hydrocarbon group, the methacrylate system is represented by the general formula (I). The methacrylate represented by the general formula (I) will also be appropriately described as "methacrylate (I)" thereafter.

(In the formula, Cy represents an alicyclic hydrocarbon group).

Methacrylate (I) includes monocyclic aliphatic hydrocarbon esters of methacrylic acid such as cyclohexyl methacrylate, cyclopentyl methacrylate, and cycloheptyl methacrylate; methacrylic acid-2 -Norbornyl, 2-methyl-2-norbornyl methacrylate, 2-ethyl-2-norbornyl methacrylate, 2-isobornyl methacrylate, methacrylic acid-2 -Methyl-2-isocampanate, methacrylic acid-2-ethyl-2-isocampanate, methacrylic acid-8-tricyclo[5.2.1.0 ^2,6 ]decyl ester, methacrylic acid-8- Methyl-8-tricyclo[5.2.1.0 ^2,6 ]decyl ester, methacrylic acid-8-ethyl-8-tricyclo[5.2.1.0 ^2,6 ]decyl ester, methacrylic acid-2-adamantane Ester, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 1-adamantyl methacrylate, 2-fenchyl methacrylate (2-fenchyl methacrylate), methacrylic acid polycyclic aliphatic hydrocarbon esters such as 2-methyl-2-fenchyl methacrylate or 2-ethyl-2-fenchyl methacrylate, etc. Among them, polycyclic aliphatic hydrocarbon methacrylate is preferred, and 8-tricyclo[5.2.1.0 ^2,6 ]decyl methacrylate is more preferred.

In one embodiment, the methacrylic resin used in the present invention preferably contains a structural unit derived from methyl methacrylate (hereinafter also appropriately referred to as "MMA") and a structure derived from methacrylate (I) The unit more preferably contains a structural unit derived from MMA and a structural unit derived from a polycyclic aliphatic hydrocarbon ester of methacrylic acid, and still more preferably contains a structural unit derived from MMA and a structural unit derived from methacrylic acid-8-tricyclic [5.2.1.0 The structural unit of ^{2,6 ]decyl ester.} The methacrylic resin may also contain structural units derived from monomers other than methacrylate (I) and MMA, but the content thereof is preferably 10% by mass or less.

From the viewpoint of hardness, the methacrylic resin used in the present invention preferably contains 40 to 80% by mass of structural units derived from MMA, more preferably 50 to 80% by mass, and even more preferably 50 to 80% by mass. 60% by mass.

From the viewpoint of reducing the linear expansion ratio (SR) described later and the viewpoint of making the glass transition temperature (Tg) 115°C or higher, the methacrylic resin used in the present invention contains 20-60% by mass of methyl The structural unit of the acrylate (I) is preferably, more preferably 20-50% by mass, and still more preferably 40-50% by mass. Structure from methacrylate (I) If the unit exceeds 60% by mass, the impact resistance of the methacrylic resin layer tends to decrease.

The methacrylic resin used in the present invention is obtained by polymerizing the above-mentioned methacrylate and other monomers as optional components. In such polymerization, when multiple types of monomers are used, the polymerization is usually carried out after mixing these plural types of monomers to prepare a monomer mixture. The polymerization method is not particularly limited, but from the viewpoint of productivity, it is preferable to perform radical polymerization using a method such as a bulk polymerization method, a suspension polymerization method, a solution polymerization method, and an emulsion polymerization method.

The weight average molecular weight of the methacrylic resin used in the present invention (hereinafter also appropriately described as "Mw") is preferably 40,000 to 500,000. By making the Mw above 40,000, the extruded resin sheet of the present invention will have excellent scratch resistance and heat resistance; by making the Mw below 500,000, it will have excellent molding processability and improve the extruded resin sheet of the present invention The productivity.

In addition, in this specification, Mw means a standard polystyrene conversion value measured using gel permeation chromatography (GPC).

[Resin composition containing methacrylic resin (1)]

In one embodiment of the present invention, the resin constituting the methacrylic resin-containing layer contains 5 mass% or more and less than 80 mass% methacrylic resin, and 20 mass% or more containing at least from the following general formula (II ) Represented by the aromatic vinyl compound (hereinafter also appropriately described as "aromatic vinyl compound (II)") and derived from the acid anhydride represented by the following general formula (III) (hereinafter also appropriately described as "acid anhydride (III) )'') of the copolymer of the structural unit (hereinafter appropriately referred to as "SMA resin") tree Grease composition (hereinafter referred to as "resin composition (1)" as appropriate). If the methacrylic resin-containing layer is composed of the resin composition (1), the adhesion with the polycarbonate-containing layer or the cured film described later will be improved.

(In the formula: R ¹ and R ² each independently represent a hydrogen atom or an alkyl group).

(In the formula: R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group).

The methacrylic resin contained in the resin composition (1) is a resin containing a structural unit derived from a methacrylate represented by the general formula (IV).

There are no particular restrictions on such methacrylates, but from the viewpoint of availability, MMA, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, N-butyl methacrylate, isobutyl methacrylate, and tertiary butyl methacrylate are most preferably MMA. The content of the structural unit derived from methacrylate in the methacrylic resin is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more, or only derived from methacrylic acid The structural unit of an ester.

Also, from the viewpoint of heat resistance, the methacrylic resin contained in the resin composition (1) preferably contains 90% by mass or more of structural units derived from MMA, more preferably 95% by mass or more, and still more It is preferable to contain 98% by mass or more, and it may only be a structural unit derived from MMA.

In addition, the methacrylic resin contained in the resin composition (1) may contain a structural unit derived from other monomers other than methacrylate. Such other monomers include: methyl acrylate (hereinafter also referred to as "MA" as appropriate), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate , Tertiary butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, octadecyl acrylate, 2-hydroxyethyl acrylate, acrylic acid- 2-hydroxypropyl ester, 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, 3-dimethylaminoethyl acrylate From the viewpoint of availability, acrylates such as MA, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and tertiary butyl acrylate are preferred. More preferred are MA and ethyl acrylate, and most preferred is MA. The content of these structural units derived from other monomers in the methacrylic resin is preferably 10% by mass or less in total, more preferably 5% by mass or less, and still more preferably 2% by mass or less.

The methacrylic resin contained in the resin composition (1) is made by polymerizing the above-mentioned methacrylate and other monomers as optional components. Get together. In such polymerization, when multiple types of monomers are used, the polymerization is usually carried out after mixing these plural types of monomers to prepare a monomer mixture. The polymerization method is not particularly limited, but from the viewpoint of productivity, it is preferable to perform radical polymerization using a method such as a bulk polymerization method, a suspension polymerization method, a solution polymerization method, and an emulsion polymerization method.

The weight average molecular weight (hereinafter appropriately described as "Mw") of the methacrylic resin contained in the resin composition (1) is preferably 40,000 to 500,000. By making the Mw above 40,000, the extruded resin sheet of the present invention has excellent scratch resistance and heat resistance; by making the Mw below 500,000, the resin composition (1) has excellent moldability, and improves the performance of the present invention. Productivity of extruded resin board.

From the viewpoint of reducing the linear expansion ratio (SR) described later and the viewpoint of making the glass transition temperature (Tg) 115°C or higher, the content of the SMA resin in the resin composition (1) used in the present invention is preferably 20 Mass% or more, more preferably 45% by mass or more and less than 95% by mass, and still more preferably 50% by mass or more and less than 90% by mass.

The content of the methacrylic resin in the resin composition (1) used in the present invention is preferably less than 80%, more preferably 5 mass% or more and less than 55% by mass, still more preferably 10 mass% or more and less than 50%. The range of mass %.

The above-mentioned SMA resin is a copolymer containing at least a structural unit derived from an aromatic vinyl compound (II) and a structural unit derived from an acid anhydride (III).

For the alkyl groups represented by R ¹ and R ² in the general formula (II) and R ³ and R ⁴ in the general formula (III) each independently, methyl, ethyl, n-propyl, iso Propyl, n-butyl, secondary butyl, isobutyl, tertiary butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, Nonyl, decyl, dodecyl and other alkyl groups with 12 or less carbon atoms, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary butyl, isobutyl, tertiary An alkyl group with 4 or less carbon atoms such as butyl group.

Respect to R ^1, preferably a hydrogen atom, methyl, ethyl and tertiary butyl. R ² , R ³ , and R ⁴ are preferably a hydrogen atom, a methyl group, and an ethyl group.

The content of the structural unit derived from the aromatic vinyl compound (II) in the SMA resin is preferably in the range of 50 to 85% by mass, more preferably 55 to 82% by mass, and still more preferably in the range of 60 to 80% by mass. If such a content is in the range of 50 to 85% by mass, the resin composition (1) will have excellent moisture resistance and transparency.

As for the aromatic vinyl compound (II), for example, styrene; 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, 4-tertiary Styrene substituted with nucleoalkyl groups such as butylstyrene; α-alkyl substituted styrenes such as α-methylstyrene and 4-methyl-α-methylstyrene, from the viewpoint of availability , Preferably styrene. These aromatic vinyl compounds (II) may be used singly, or a plurality of them may be used in combination.

The content of the structural unit derived from the acid anhydride (III) in the above-mentioned SMA resin is preferably in the range of 15-50% by mass, more preferably in the range of 18-45% by mass, and still more preferably in the range of 20-40% by mass. With such a content in the range of 15-50% by mass, the resin composition (1) will have heat resistance and transparency.

The acid anhydride (III) includes, for example, maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, etc., from the viewpoint of availability, maleic anhydride is preferred Diacid anhydride. These acid anhydrides (III) may be used individually by 1 type, and may use multiple types together.

In addition to the aromatic vinyl compound (II) and the acid anhydride (III), the above-mentioned SMA resin preferably contains a structural unit derived from a methacrylate monomer. The content of the structural unit derived from the methacrylate monomer in the SMA resin is preferably in the range of 1 to 35% by mass, more preferably in the range of 3 to 30% by mass, and still more preferably in the range of 5 to 26% by mass . With such a content in the range of 1 to 35% by mass, it has excellent bending workability and transparency.

Such methacrylates include, for example, MMA, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, propyl methacrylate, and methacrylic acid. Isopropyl ester, n-butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, Benzyl methacrylate, 1-phenylethyl methacrylate, etc. Among these methacrylates, alkyl methacrylates having an alkyl group of 1 to 7 carbon atoms are preferred, and MMA is particularly preferred from the viewpoint of excellent heat resistance or transparency of the resulting SMA resin . Moreover, a methacrylate type may be used individually by 1 type, and may use a plurality of types together.

The above-mentioned SMA resin may have a structural unit derived from a monomer other than the aromatic vinyl compound (II), acid anhydride (III), and methacrylate. In terms of such other monomers, examples include MA, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, propylene Isobutyl acrylate, tertiary butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, 2-hydroxy acrylate Ethyl, 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, 3-dimethyl acrylate Acrylic esters such as ethyl amino ethyl ester. These other single systems may be used alone or in combination of plural types. The content of the structural unit derived from the other monomer in the SMA resin is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 2% by mass or less.

The above-mentioned SMA resin is obtained by polymerizing the above-mentioned aromatic vinyl compound (II), acid anhydride (III), methacrylate, and other monomers as optional components. In such polymerization, the monomers to be used are usually mixed to prepare a monomer mixture, and then the polymerization is carried out. The polymerization method is not particularly limited, but from the viewpoint of productivity, it is preferable to perform radical polymerization using a method such as a bulk polymerization method and a solution polymerization method.

The Mw of the above-mentioned SMA resin is preferably in the range of 40,000 to 300,000. By making the Mw above 40,000, the extruded resin sheet of the present invention will have excellent scratch resistance and impact resistance; by making the Mw below 300,000, it will have excellent moldability and improve the extruded resin of the present invention The productivity of the board.

The above-mentioned resin composition (1) is obtained by mixing the above-mentioned methacrylic resin and the above-mentioned SMA resin. Examples of the hybrid system that can be used Such as melt mixing method, solution mixing method and so on. In the melt-mixing method, for example, a single-shaft or multi-shaft mixer, an open roll, a Banbury closed-type mixer, a kneader, and other melt-kneaders are used, and if necessary, nitrogen and argon are used. Melting and kneading in an inert gas environment such as gas and helium. In the solution mixing method, the methacrylic resin and the SMA resin are dissolved and mixed in an organic solvent such as toluene, tetrahydrofuran, and methyl ethyl ketone.

[Layer containing methacrylic resin]

The resin constituting the methacrylic resin-containing layer used in one embodiment of the present invention may contain other polymers other than the methacrylic resin and the SMA resin within a range that does not impair the effects of the present invention. Such other polymers include polyolefins such as polyethylene and polypropylene, polyamide, polyphenylene sulfide, polyether ether ketone, polyester, polysulfide, polyphenylene ether, polyimide, Thermoplastic resins such as polyetherimide and polyacetal; thermosetting resins such as phenol resin, melamine resin, silicone resin, epoxy resin, etc. These other polymer systems may be used individually by 1 type, and may use multiple types together.

The content of these other polymers in the resin constituting the methacrylic resin-containing layer used in one embodiment of the present invention is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 2% by mass %the following.

When the methacrylic resin contains other polymers and/or additives, it may be added during polymerization of the methacrylic resin, or may be added after the polymerization.

When the resin composition (1) contains other polymers and/or additives, it can be added when polymerizing methacrylic resin and/or SMA resin, or when methacrylic resin and SMA resin are mixed, or when mixing methyl Add after acrylic resin and SMA resin.

Various additives may be optionally added to the resin constituting the methacrylic resin-containing layer used in one embodiment of the present invention. The additives include, for example, antioxidants, thermal degradation inhibitors, ultraviolet absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes/pigments , Light diffusers, matting agents, impact modifiers such as core-shell particles or block copolymers, phosphors, etc. The content of these additives can be appropriately set within a range that does not impair the effects of the present invention. For example, the content of the antioxidant is preferably 0.01 to 1 relative to 100 parts by mass of the resin constituting the methacrylic resin-containing layer. The content of the ultraviolet absorber is preferably 0.01~3 parts by mass, the content of the light stabilizer is preferably 0.01~3 parts by mass, the content of the lubricant is preferably 0.01~3 parts by mass, and the content of the dye/pigment is more Preferably, it is 0.01 to 3 parts by mass.

The melt flow rate of the resin constituting the methacrylic resin-containing layer used in one embodiment of the present invention (hereinafter appropriately referred to as "MFR") is preferably in the range of 1 to 10 g/10 min, more preferably 1.5 to The range of 7g/10 minutes is more preferably 2~4g/10 minutes. When the MFR is in the range of 1 to 10 g/10 minutes, the stability of the heat-melt molding is good.

In addition, the MFR of the resin constituting the methacrylic resin-containing layer in this specification refers to a value measured using a melt indexer at a temperature of 230°C and a load of 3.8 kg.

[Polycarbonate]

It is suitable to obtain the polycarbonate used in the extruded resin sheet of the present invention by copolymerizing a dihydric phenol and a carbonate precursor.

For the above-mentioned dihydric phenols, there can be mentioned: 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 1,1-bis(4-hydroxyphenyl)ethane, 1,1 -Bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxybenzene) Yl)propane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfide, etc., among which bisphenol A is preferred. These dihydric phenols can be used alone or in combination Plural.

The aforementioned carbonate precursors include halogenated carbonyl groups such as phosgene, carbonates such as diphenyl carbonate, and haloformates such as dihaloformates of dihydric phenols. These carbonate precursor systems can be used individually by 1 type, and can also use multiple types together.

The production method of the above polycarbonate is not particularly limited. For example, it can be enumerated: an interfacial polymerization method in which an aqueous solution of a dihydric phenol and an organic solvent solution of a carbonate precursor react at the interface, or a dihydric phenol and a carbonate precursor Transesterification method that reacts under high temperature, reduced pressure, and solvent-free conditions, etc.

The Mw of the polycarbonate is preferably in the range of 10,000 to 100,000, more preferably in the range of 20,000 to 70,000. If the Mw is above 10,000, the extruded resin sheet of the present invention will have excellent impact resistance and heat resistance. When the Mw is below 100,000, the polycarbonate will have excellent molding processability and improve the production of the extruded resin sheet of the present invention. Sex.

The above-mentioned polycarbonate may contain other polymers within a range that does not impair the effects of the present invention. With regard to this other polymer, the same polymers as other polymers that may be contained in the methacrylic resin, the resin composition (1), and the above-mentioned resin composition (1) can be used. These other polymer systems may be used individually by 1 type, and may use multiple types together. Among other things in polycarbonate The content of the polymer is preferably 15% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less.

Various additives may be added to the polycarbonate as necessary, and as the additives, the same additives as those that can be contained in the resin constituting the methacrylic resin-containing layer described above can be used. The content of these additives can be appropriately set within a range that does not impair the effects of the present invention. Relative to 100 parts by mass of polycarbonate, the content of antioxidant is preferably 0.01 to 1 part by mass, and the content of ultraviolet absorber It is preferably 0.01 to 3 parts by mass, the content of light stabilizer is preferably 0.01 to 3 parts by mass, the content of lubricant is preferably 0.01 to 3 parts by mass, and the content of dye/pigment is preferably 0.01 to 3 parts by mass.

When other polymers and/or additives are added to the above polycarbonate, they may be added when the dihydric phenol and the carbonate precursor are copolymerized, or they may be added after the copolymerization is completed for melt-kneading.

The glass transition temperature (Tg) of the polycarbonate is preferably in the range of 120 to 160°C, more preferably in the range of 135 to 155°C, and still more preferably in the range of 140 to 150°C.

The MFR of the polycarbonate is preferably in the range of 1 to 30 g/10 minutes, more preferably in the range of 3 to 20 g/10 minutes, and still more preferably in the range of 5 to 10 g/10 minutes. If the MFR is in the range of 1 to 30 g/10 minutes, the stability of the heat-melt molding is good.

In addition, the MFR of polycarbonate in this specification refers to the one measured with a melt index meter under the conditions of a temperature of 300°C and a load of 1.2 kg.

Commercial products can be used for the above-mentioned polycarbonate series. For example, it can be suitably used: manufactured by Sumika Styron Polycarbonate Co., Ltd. CALIBRE (registered trademark)" and "SD POLYCA (registered trademark)", "Iupilon/NOVAREX (registered trademark)" manufactured by Mitsubishi Engineering-Plastics Co., Ltd., "TARFLON (registered trademark)" manufactured by Idemitsu Kosan Co., Ltd., Teijin "Panlite (registered trademark)" manufactured by Kasei Co., Ltd., etc.

[Extruded resin board]

In the extruded resin sheet, the linear expansion ratio (SR) expressed by the relational expression of the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer is defined as As the ratio of the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer (S2-S1) to the linear expansion coefficient (S1), the formula ( (S2-S1)/S1) represents the value.

The linear expansion ratio (SR) is preferably in the range of -10% to +5%, and from the viewpoint of achieving good warpage reduction, the linear expansion ratio (SR) is more preferably in the range of -5% to +2%. When the linear expansion ratio (SR) is within this range, it is easy to obtain an extruded resin sheet with good surface properties and small warpage due to residual stress.

The thickness of the extruded resin sheet of the present invention is preferably 0.1 to 3.0 mm, more preferably 0.5 to 2.0 mm. If it is too thin, the rigidity tends to be insufficient; if it is too thick, it tends to hinder the weight reduction of liquid crystal display devices and the like.

The thickness of the methacrylic resin-containing layer of the extruded resin sheet of the present invention is preferably 20 to 200 μm. Within this range, the balance between scratch resistance and impact resistance is excellent. It is more preferably 25 to 150 μm, and still more preferably 30 to 100 μm.

The thickness of the polycarbonate-containing layer of the extruded resin sheet of the present invention is better It is 0.1~3.0mm, more preferably 0.5~2.0mm. If it is too thin, the impact resistance tends to be insufficient; if it is too thick, it tends to hinder the weight reduction of liquid crystal display devices and the like.

The extruded resin sheet of the present invention may have another resin layer if a methacrylic resin-containing layer is laminated on at least one surface of the polycarbonate-containing layer. For example, it can include: two layers of polycarbonate-containing layer-methacrylic resin-containing layer; three layers of methacrylic resin-containing layer-polycarbonate-containing layer-methacrylic resin-containing layer; Acrylic resin-based layer-polycarbonate-containing layer-3 layers of other resin layers; other resin layer-methacrylic resin-containing layer-3 layers of polycarbonate-containing layer; etc.

The extruded resin sheet of the present invention may also be provided with a hardened film on at least one surface. By providing a hardened film, it is possible to provide functions such as scratch resistance and low reflectivity.

For example, the thickness of the scratch-resistant (hard coating) cured film is preferably 2 to 30 μm, more preferably 5 to 20 μm. If it is too thin, the surface hardness is insufficient; if it is too thick, there is a possibility of cracks due to bending in the manufacturing step.

Also, for example, the thickness of the low-reflection cured film is preferably 80 to 200 nm, and more preferably 100 to 150 nm. This is because whether it is too thin or too thick, the low reflection performance will become insufficient.

[Manufacturing steps]

The extruded resin sheet according to one embodiment of the present invention is produced by coextrusion. The resins constituting the polycarbonate-containing layer and the methacrylic resin-containing layer are heated and melted, and the polycarbonate-containing layer is laminated on at least one surface In the state of a thermoplastic resin laminate with a methacrylic resin-containing layer, it is extruded in a molten state from a wide-shaped discharge port called a T-die, and a first cooling roll and a second cooling roll are used. The rolls are nipped and formed into a sheet shape. After that, the thermoplastic resin laminate is further wound on the second cooling roll, and then is wound on at least the third cooling roll for cooling. In addition, the thermoplastic resin laminate (extruded resin sheet 16) may be further cooled by more cooling rolls after that.

In addition, the heat-melted state is mainly expressed as a thermoplastic resin laminate, and the cured state is expressed as an extruded resin sheet, but there is no clear boundary between the two.

FIG. 1 shows an outline of a manufacturing method of an extruded resin sheet using a co-extrusion device composed of a T-die 11, first to third cooling rolls 12 to 14 and a drawing roll 15 as an embodiment. The thermoplastic resin laminate system extruded from the T-die 11 is formed into a sheet-like extruded resin sheet 16 sandwiched by a pair of rolls composed of the first cooling roll 12 and the second cooling roll 13. After that, the extruded resin sheet 16 is further cooled by the third cooling roll 14, and it is pulled through the pulling roll 15 composed of a pair of rolls. In this case, the third cooling roll 14 is the cooling roll wound last.

Another roll may be provided between the third cooling roll and the take-up roll as a form other than FIG. 1. In this case, the roll to be wound last among the third cooling roll or the rolls provided between the third cooling roll and the take-up roll is the last roll to wind the thermoplastic resin laminate.

In the following, for simplification, the form of FIG. 1 in which the cooling roll wound last is the third cooling roll will be described as an example. In addition, the present invention is not limited to this form.

As for the method of the T-shaped mold at this time, it is possible to adopt a feed block method in which the resin constituting the polycarbonate-containing layer and the methacrylic resin-containing layer in a heated and molten state are laminated before flowing into the T-shaped mold, The method of multiple branch pipes layered inside the T-shaped pattern, etc. From the viewpoint of improving the smoothness of the interface between the layers constituting the extruded resin sheet, the multiple branch pipe method is preferred.

In addition, as the buffing roller at this time, a metal roller or an elastic roller provided with a metal film on the outer peripheral portion (hereinafter may be referred to as a metal elastic roller), and the like can be mentioned. The metal roll is not particularly limited as long as it has high rigidity, and examples include drill rolls, spiral rolls, and the like. The surface state of the metal roller is not particularly limited. For example, it may be a mirror surface, or may be a pattern or unevenness. The metal elastic roller is composed of, for example, a substantially cylindrical roller that is set to be rotatable, a cylindrical metal film arranged so as to cover the outer peripheral surface of the roller and in contact with a sheet-like thermoplastic resin, and sealed therein. The fluid between the shaft roller and the metal film is formed, and the metal elastic roller system exhibits elasticity through the fluid. The shaft roller is not particularly limited, and is made of stainless steel, for example. The metal thin film is made of, for example, stainless steel, and its thickness is preferably about 2 to 5 mm. The metal film preferably has flexibility or flexibility, etc., and preferably has a seamless structure without welded joints. The metal elastic roller provided with such a metal film has excellent durability, and if the metal film is mirror-finished, it can perform the same operation as a general mirror roller, and if the metal film can be provided with patterns or irregularities, It becomes a roller that can transfer its shape, so it has good practicability.

Constitute a polycarbonate-containing layer and a methacrylic resin-containing layer The resin of the layer is preferably melt-filtered with a filter before and/or during the multilayer molding. Multi-layer molding is performed using each resin that has been melted and filtered, and an extruded resin sheet with few defects due to foreign matter or gel can be obtained. There are no special restrictions on the filter material of the filter used, and it can be appropriately selected according to the temperature, viscosity, and filtration accuracy. For example, it can be used: non-woven fabrics composed of polypropylene, cotton, polyester, rayon, glass fiber, etc.; Phenolic resin impregnated cellulose flakes; metal fiber non-woven fabric sintered flakes; metal powder sintered flakes; metal wire mesh; or a combination of these. Among them, from the standpoint of heat resistance and durability, it is preferable to laminate a plurality of metal fiber nonwoven fabric sintered sheets to use.

The filtration accuracy of the aforementioned filter is not particularly limited, but it is preferably 30 μm or less, more preferably 15 μm or less, and still more preferably 5 μm or less.

The extruded resin sheet of one embodiment of the present invention is based on the temperature of the entire resin peeled from the third cooling roll 14 relative to the glass transition temperature (Tg) of the polycarbonate in the range of -2°C to +15°C. good. This is because if the temperature of the entire resin peeled off from the third cooling roll 14 is lower than the glass transition temperature (Tg) of polycarbonate, the extruded resin sheet will transfer the shape of the third cooling roll and warp will change Big. On the other hand, if the temperature of the entire resin peeled from the third cooling roll 14 is higher than the glass transition temperature (Tg) of the resin layer in contact with the third cooling roll, the extruded resin sheet cannot obtain beautiful surface properties. In addition, the temperature of the entire resin is used by measuring the temperature of the entire resin in which the polycarbonate resin and the methacrylic resin are laminated regardless of either side of the extruded resin sheet. Only use infrared radiation for temperature measurement Just shoot the thermometer.

The extruded resin sheet of one embodiment of the present invention preferably has a linear expansion ratio (SR) in the range of -10% to +5%, and the glass transition temperature of the layer containing methacrylic resin ( Tg) is preferably set at 115°C or higher. The reason is described below.

The extruded resin sheet peeled from the third cooling roll 14 is sandwiched between the pull roll 15 and is sandwiched between the third cooling roll 14 and the pull roll 15, and thus has a flat shape. The temperature of the extruded resin sheet after peeling off the third cooling roll 14 is in the range of -2°C to +15°C relative to the glass transition temperature (Tg) of the polycarbonate. However, the temperature of the extruded resin sheet near the pull roll 15 is The temperature is cooled to room temperature, so it is approximately room temperature.

In addition, for example, it is assumed that the temperature of the extruded resin sheet peeled from the third cooling roll 14 is 150°C, and the temperature of the extruded resin sheet near the drawing roll is 25°C. In the case where there is a difference between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer, specifically, the linear expansion ratio (SR) of (S1) When -S2)/S1 is other than zero, the side with the larger linear expansion coefficient will shrink and warp will occur.

In addition, for example, it is assumed that the glass transition temperature (Tg) of the methacrylic resin-containing layer is 100°C, and the glass transition temperature (Tg) of the polycarbonate-containing layer is 150°C. In this case, since the temperature of the extruded resin sheet peeled from the third cooling roll 14 is 150°C, the polycarbonate-containing layer is cooled from 150°C of the glass transition temperature (Tg) to room temperature. Therefore, in the polycarbonate-containing layer, there will be a shrinkage approximately along the linear expansion coefficient.

On the other hand, the layer containing methacrylic resin will be cooled from a region higher than the glass transition temperature (150°C) to the glass transition temperature (Tg). Around 100°C, even if there is no difference between the coefficient of linear expansion (S1) of the polycarbonate-containing layer and the coefficient of linear expansion (S2) of the resin of the methacrylic resin-containing layer, the The methacrylic resin layer still has large shrinkage that exceeds the linear expansion coefficient.

Here, a general resin is an elastomer below the glass transition temperature, but once it is above the glass transition temperature, it becomes a viscoelastic body that has both viscous and elastic functions.

If stress is applied to the above-mentioned elastomer, strain will be generated, but if it is unloaded, the strain will be eliminated. Conversely, if the viscoelastic body is directly cooled to the glass transition temperature under stress, strain will remain. When the temperature of the extruded resin sheet peeled off from the third cooling roll 14 is, for example, 150°C and the methacrylic resin-containing layer and the polycarbonate-containing layer are at the above-mentioned glass transition temperature, the extruded resin sheet is cooled from the third After the roller 14 is peeled off, the polycarbonate-containing layer is an elastomer, and on the contrary, the methacrylic resin-containing layer is a viscoelastic body. That is, after peeling off the extruded resin sheet from the third cooling roll 14, only the methacrylic resin-containing layer which is a viscoelastic body undergoes shrinkage strain. In other words, the polycarbonate layer, which is an elastomer, is reversible with respect to stress, and therefore does not deform even if there is a stress load/unload. Conversely, the methacrylic resin-containing layer, which is a viscoelastic body, generates residual strain due to stress loading/unloading.

From the above point of view, when there is a difference between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer, in other words, the linear expansion ratio (SR) When the absolute value of is large, warpage due to the difference in shrinkage of the elastomer will occur, and therefore warpage will occur when the extruded resin sheet is released from the drawing roll 15.

In addition, the glass transition temperature (Tg) of the methacrylic resin-containing layer is lower than the glass transition temperature (Tg) of the polycarbonate-containing layer, and the temperature of the extruded resin sheet peeled from the third cooling roll 14 is lower than When the glass transition temperature (Tg) of the methacrylic resin-containing layer is between the glass transition temperature (Tg) of the polycarbonate-containing layer, the difference in shrinkage between the elastomer and the viscoelastic body will cause the Strain remains in the acrylic resin layer. This residual strain tends to release strain and warp due to exposure to high temperature, high temperature and high humidity conditions. Here, since the temperature of the extruded resin sheet after peeling from the third cooling roll 14 relative to the glass transition temperature (Tg) of the polycarbonate is -2°C to +15°C, there is also a viscoelastic body in the polycarbonate status. Here, the temperature of the extruded resin sheet will be cooled to normal temperature before reaching the drawing roll 15, but both the methacrylic resin-containing layer and the polycarbonate-containing layer will be cooled to normal temperature at the same time. Therefore, the temperature of the extruded resin sheet after peeling from the third cooling roll 14 to the drawing roll 15 will include the glass transition temperature (Tg) of the polycarbonate and the glass transition temperature (Tg) of the layer containing the methacrylic resin. . In other words, when the temperature of the extruded resin sheet is cooled from the glass transition temperature (Tg) of the polycarbonate to the glass transition temperature (Tg) of the methacrylic resin-containing layer, the temperature of the methacrylic resin-containing layer In the residual strain.

On the other hand, in principle, if the temperature of the extruded resin sheet peeled from the third cooling roll 14 is lower than 150°C, the warpage and residual stress due to the linear expansion ratio (SR) will tend to decrease, so The warpage will become smaller. However, as described above, the warpage of the extruded resin sheet due to the transfer of the shape of the third cooling roll 14 becomes large, which is not preferable.

From this point of view, in order to achieve the purpose of this case, the third The temperature of the resin peeled off by the cooling roller 14 relative to the glass transition temperature (Tg) of the polycarbonate is set in the range of -2°C to +15°C, and the linear expansion ratio (SR) is set in the range of -10% to +5% It is preferable to set the glass transition temperature (Tg) of the layer containing the methacrylic resin to 115° C. or higher to obtain a good extruded resin sheet with less warpage.

Hysteresis refers to the phase difference between light in the direction of the molecular main chain and light in the direction perpendicular to it. Polymers can generally be formed into any shape by heating, but it is known that fixed stress occurs during the heating and cooling processes, and the molecules are aligned to cause hysteresis. Therefore, in order to control the hysteresis, it is necessary to control the alignment of the molecules. The alignment of molecules occurs, for example, through stress during molding near the glass transition temperature of the polymer.

The inventors of the present invention found a way to control the alignment of molecules by adjusting various manufacturing conditions during the extrusion molding process, and prevent at least a part of the in-plane hysteresis in the width direction caused by heating after the extrusion of the resin sheet ( The following is sometimes only described as the method of reducing the "in-plane hysteresis value"). The influence of the peripheral speed ratio and the heating conditions are described below.

<About the influence of peripheral speed ratio>

The peripheral speed ratio refers to the ratio of the peripheral speeds of any cooling rolls and take-up rolls other than the second cooling roll 13 to the peripheral speeds of the second cooling roll 13, and then the peripheral speed of the second cooling roll is expressed as V2, and the third cooling roll The peripheral speed system of is denoted as V3, and the peripheral speed of the pulling roll is denoted as V4.

The relationship between the peripheral speed ratio (V3/V2) of the third cooling roll 14 to the second cooling roll 13 and the in-plane hysteresis value was evaluated based on predetermined conditions as described below.

The temperature of the resin peeled from the third cooling roll 14 is adjusted to a range of -2°C to +15°C with respect to the glass transition temperature (Tg) of the polycarbonate.

The temperature of the resin at which the resin contacts the third cooling roll 14 is higher than the temperature of the resin peeled from the third cooling roll 14 because the resin is cooled by the third cooling roll. In other words, the temperature of the resin in contact with the third cooling roller 14 will be higher than the glass transition temperature (Tg) of polycarbonate from -2°C to +15°C, for example, it will be higher than the glass transition temperature (Tg) relative to the glass transition temperature ( Tg) is around +20°C. In this case, it is assumed that even if the peripheral speed ratio (V3/V2) of the third cooling roll 14 is increased and a large tensile stress is applied to the extruded resin sheet, it is because it is a resin in a high temperature region where the molecules of the resin are not easily aligned. Therefore, the in-plane hysteresis value will not be significantly increased (refer to Example 14 described later).

After evaluating the relationship between the peripheral speed ratio (V4/V2) of the drawing roll 15 to the second cooling roll 13 and the in-plane hysteresis value, it was found that the greater the peripheral speed ratio (V4/V2), the greater the in-plane hysteresis value. The more it increases.

The reason is thought to be that the resin temperature when the resin is peeled from the third cooling roll 14 is adjusted to a temperature slightly higher than the glass transition temperature (Tg) of the polycarbonate. Specifically, the resin is peeled from the third cooling roll 14 The resin temperature is adjusted to the range of -2°C~+15°C relative to the glass transition temperature (Tg), and the peripheral speed ratio of the drawing roll 15 is increased to apply greater tensile stress to the extruded resin sheet. Reach the temperature region where the molecules of the resin are easy to align.

Next, the extent to which the in-plane hysteresis value decreases when the resin sheet is heated and extruded is discussed.

When the resin temperature when the resin is peeled from the third cooling roll 14 is lower than the glass transition temperature (Tg) of the polycarbonate, the peripheral speed ratio (V4/V2) of the second cooling roll 13 and the drawing roll 15 is gradually increased. When increasing, it can be seen that the in-plane hysteresis value gradually increases, but the rate of decrease in the in-plane hysteresis value after heating increases (refer to Comparative Examples 1 and 2 described later).

When the resin temperature when the resin is peeled from the third cooling roll 14 relative to the glass transition temperature (Tg) of the polycarbonate is in the range of -2°C to 15°C, the circumference of the second cooling roll 13 and the drawing roll 15 When the speed ratio (V4/V2) gradually increases, the in-plane hysteresis value gradually increases, but the amount of decrease in the in-plane hysteresis value during heating does not change significantly (see Examples 10, 11, and 12 described later).

The reason is considered to be that by adjusting the resin temperature when the resin is peeled from the third cooling roll 14 to the glass transition temperature (Tg) of polycarbonate in the range of -2°C to 15°C, the drawing roll 15 is increased. The peripheral speed ratio of the extruded resin sheet is greater, the molecules of the resin will be aligned, or because the heating temperature is lower than the glass transition temperature (Tg) of polycarbonate, the resin’s The alignment is difficult to ease.

From this point of view, in order to achieve the purpose of the present invention, it can be seen that the temperature of the resin when peeling from the third cooling roll 14 is controlled within the range of -2°C to 15°C relative to the glass transition temperature (Tg) of the polycarbonate. It is only necessary to adjust the peripheral speed ratio of the cooling roller 13 and the take-up roller 15 to control the in-plane hysteresis value.

Specifically, for example, the peripheral speed ratio (V4/V2) of the drawing roll and the second cooling roll is set to 0.98 or more and 1.01 or less.

Also, the peripheral speed ratio of the second cooling roll 13 to the take-up roll 15 is greater than At 1.01, the in-plane hysteresis value tends to be greater than 600 nm (see Comparative Example 5 described later); when it is less than 0.98, the in-plane hysteresis value tends to be less than 50 nm (see Comparative Example 6 described later). From the viewpoint of setting the in-plane hysteresis value in a preferable range, the circumferential speed ratio of the second cooling roll 13 to the drawing roll 15 is more preferably 0.985 to 0.995 (refer to Example 10 described later).

Also, when the in-plane hysteresis value of the liquid crystal display protection plate is greater than 600 nm, when viewed through a polarizing filter such as polarized sunglasses, the difference in transmittance of each wavelength in the visible light range increases, making it difficult to recognize various colors. On the other hand, when it is less than 50 nm, the transmittance at all wavelengths in the visible light range is greatly reduced, and it becomes a completely black image that is difficult to recognize. In the range of 50nm~600nm, the larger the value, the brighter the image, and the smaller the value, the lighter the color. In particular, when the in-plane hysteresis value is set to 80 nm to 350 nm, the balance of brightness and color is good, and visibility is excellent, so it is preferable.

<heating conditions>

Regarding the heating conditions of the present invention, the range of 75°C to 100°C is set, but when the measurement is performed, one of 75°C, 5 hours and 100°C, 5 hours is used. The above-mentioned heating environment refers to the heating temperature and time in the process of forming a general cured film, and it is preferable to withstand the heating environment while maintaining the hysteresis.

Specifically, the measurement is performed by placing the test piece in an oven controlled at 100°C±3°C or 75°C±3°C for 5 hours.

As described above, in the above-mentioned method of manufacturing an extruded resin sheet, it is preferable to control so that the manufactured extruded resin sheet has the following characteristics.

The extruded resin sheet is used to heat the extruded resin sheet at a temperature of 75°C to 100°C for 5 hours, so that the in-plane hysteresis value is 50 to 600 nm in at least a part of the width direction before and after heating, and before and after heating The decrease rate of the in-plane hysteresis value is less than 15% to control the manufacturing steps.

In addition, the extruded resin plate is preferably used to control the manufacturing process such that the in-plane hysteresis value is 80 to 350 nm in at least a part of the width direction before and after heating.

In addition, the extruded resin sheet is preferably used to control the manufacturing process so that the decrease rate of the in-plane hysteresis value before and after heating is less than 10%.

Since the extruded resin sheet of the present invention has the above-mentioned characteristics, it is possible to manufacture an extruded resin sheet suitable for liquid crystal display protection plates and the like through a step of heating at a temperature of 65°C to 110°C for 1 to 30 hours.

<Use>

The extruded resin sheet of the present invention has good surface properties and can suppress the occurrence of warpage. Even if heated to high temperature and high temperature, the reduction rate of the in-plane hysteresis value is small and has an appropriate in-plane hysteresis value. Therefore, the extruded resin sheet and The resin sheet that heats the extruded resin sheet can be used for various purposes, especially suitable for ATMs, vending machines, mobile phones, mobile information terminals (PDAs), digital audio players, and mobile game consoles in financial institutions such as banks. , Tablet PCs, copiers, faxes, car navigation and other digital information equipment touch panel protection board; LCD display protection board.

[Example]

Examples are shown below to illustrate the present invention in more detail. However, the present invention is not limited in any way by such embodiments.

The physical properties of the extruded resin plate were measured by the following method.

[Glass transition temperature (Tg)]

After drying the obtained extruded resin sheet at 80°C for 24 hours under reduced pressure (1kPa), a 10 mg test piece was cut out, sealed with an aluminum pan, and a differential scanning calorimeter ("DSC-50", Rigaku Co., Ltd.) was used. Made by the company), nitrogen replacement is performed for more than 30 minutes. After that, in a nitrogen gas flow of 10 ml/min, the temperature was temporarily increased from 25°C to 200°C at a rate of 20°C/min, held for 10 minutes, and cooled to 25°C (1 scan). Next, the temperature was raised to 200°C at a rate of 10°C/min (2 scans), and the glass transition temperature (Tg) was calculated by the midpoint method from the results of the 2 scans. In addition, when a plurality of glass transition temperatures are obtained by containing two or more kinds of resins, the value of the resin derived from the main component is adopted as the glass transition temperature.

[Linear expansion coefficient]

The coefficient of linear expansion is defined as the rate of change in length per unit temperature change, and the coefficient of linear expansion is measured in accordance with JIS K7197 using a thermomechanical analyzer ("TMA4000" manufactured by Bruker AXS Co., Ltd.). That is, a diamond saw was used to form a smooth end surface on a sheet-like extruded resin plate formed by pressing each measured resin, and processed into a square column with a length of 5mm×5mm and a height of 10mm. The processed samples Place a 5mm×5mm surface on the quartz plate in such a way that the surface is in contact with the quartz plate, place a cylindrical rod on it, and apply a compression load of 5g to fix it. Next, in an air environment, the temperature was raised from 25°C (room temperature) to -10°C of the glass transition temperature (Tg) of each sample at a heating rate of 3°C/min, and then cooled to 25°C (room temperature) (scanning once) ). In addition, the temperature was increased from 25°C (room temperature) to +20°C (2 scans) of the glass transition temperature (Tg) of each sample at a temperature increase rate of 3°C/min. Measure the expansion rate at each temperature in 2 scans, and find the range of 30℃~80℃ Average linear expansion coefficient.

[Warpage amount]

The extruded resin sheets of the Examples and Comparative Examples were cut into rectangles with the short side as the short side in the direction parallel to the extrusion flow direction and the long side as the direction perpendicular to the extrusion flow direction, to produce a short side of 65mm and a long side of 110mm. Audition. Place the produced test piece on the platform with the layer containing the methacrylic resin facing up, and place it in an environment with a temperature of 23° C. and a relative humidity of 50% for 24 hours. After that, use a feeler gauge to measure the maximum value of the gap between the test piece and the platform, and set this value as the initial warpage. Next, in an environmental testing machine set to a temperature of 85°C and a relative humidity of 85%, the aforementioned test piece was placed on a glass platform with the methacrylic resin-containing layer facing up. After leaving it in this state for 72 hours, Place it at a relative humidity of 50% and 23°C for 4 hours. After that, the measurement was performed in the same manner as described above, and this value was defined as the amount of warpage after high temperature and high humidity. The test piece was placed on the platform with the methacrylic resin-containing layer facing upward, and the sign of the downward convex warpage was set as +, and the sign of the upward convex warpage was set as -. The amount of warpage is within ±0.5mm as qualified.

[Heating conditions]

The test piece was cut using a running saw to produce a 100mm square test piece. In the heating system, the test piece is placed in an oven controlled at 100°C±3°C for 5 hours.

[Determination of Hysteresis Value]

The test piece is cut with a self-propelled saw to make a 100mm square test piece. Place the test piece at 23°C±3°C for more than 10 minutes, and measure the hysteresis using WPA-100(-L) manufactured by Photonic Lattice Co., Ltd. Value, the measurement position is near the center of the measurement test piece.

In addition, the same measurement was performed on the test piece subjected to the above-mentioned heating conditions.

The rate of change of the hysteresis is obtained by the following equation.

Change rate (%)=([Hysteresis value before heating]-[Hysteresis value after heating])/[Hysteresis value before heating]×100

[Visual evaluation method when equipped with polarized sunglasses]

The test piece is cut with a self-propelled saw to make a 100mm square test piece.

Then set up the liquid crystal display device at a distance of 35 cm from the eyes and display the image, and then set the pre-heated test strips of the examples and comparative examples to be parallel to the screen of the display device at a distance of 30 cm between the liquid crystal display device and the eyes. , Orient the methacrylic resin-containing layer side of the test piece toward the eye.

First, the polarized sunglasses were not equipped and the image was visually observed through the thickness direction of the test piece.

Next, the polarized sunglasses were equipped and the head was tilted left and right with the face facing the image, and the image was visually observed as described above.

After that, except for changing the test piece before heating to the test piece after heating, the same procedure was performed as described above, and the image was visually observed for the case of not equipped with polarized sunglasses and the case of equipped with polarized sunglasses.

○: The appearance of the image does not change significantly with or without polarized sunglasses, and the image can be recognized without problems.

×: Compared with the case of not equipped with polarized sunglasses, the appearance of the image becomes a dark image when the head is tilted to a certain angle with polarized sunglasses, or a deep coloration is observed and it is difficult to see the image.

[Surface]

In a room where a fluorescent lamp was installed, both sides of the extruded resin plate were visually observed, and the surface properties were evaluated based on the following criteria.

○: No vibration marks are observed on the surface of the extruded resin plate.

△: Vibration marks are observed on the surface of the extruded resin plate, but are not noticeable.

×: Vibration marks are conspicuous on the surface of the extruded resin plate.

[Resin temperature]

At the position peeled from the third cooling roll 14, the temperature of the entire extruded resin sheet 16 is measured with an infrared radiation thermometer, and the temperature measured in this way is referred to as the resin temperature (TT).

[Methacrylic resin A]

As methacrylic resin A, "PARAPET (registered trademark) HR" manufactured by KURARAY Co., Ltd. (MFR at a temperature of 230°C and a load of 3.8 kg = 2.0 cm ³ /10 minutes) was prepared.

[Methacrylic resin B]

The copolymer obtained by radical polymerization of methyl methacrylate and methacrylic acid-8-tricyclo[5.2.1.0 ^2,6 ]decyl ester is prepared as methacrylic resin B.

Also, the total dose of methacrylic acid-8-tricyclo[5.2.1.0 ^2,6 ]decyl ester in methyl methacrylate and methacrylic acid-8-tricyclo[5.2.1.0 ^{2,6]decyl ester} The incorporation ratio (mass percentage) accounted for in is called the TC ratio.

[Resin composition (1)]

In the production example, the following methacrylic resin and SMA resin were used.

<Methacrylic resin>

Methacrylic resin system "PARAPET (registered trademark) HR" (same as methacrylic resin A) manufactured by Kuraray Co., Ltd. was prepared as a methacrylic resin.

<SMA resin>

The SMA resin can be obtained by the following method.

By the method described in WO2010/013557, SMA resin as a styrene-maleic anhydride-MMA copolymer can be obtained.

Table 1 shows the mass composition ratio and weight average molecular weight (Mw) of the SMA resin used.

<mass composition ratio>

According to the following procedure, the copolymerization composition of the SMA resin was obtained ^{using the 13 C-NMR method.}

¹³ C-NMR spectroscopy system uses a nuclear magnetic resonance device (GX-270 manufactured by JEOL Ltd.) to prepare a sample solution by dissolving 1.5 g of SMA resin in 1.5 ml of deuterated chloroform. The accumulative number is 4000~ The measurement was performed under the condition of 5000 times, and the following values were obtained from the measurement results.

‧[Integrated intensity of the carbon peaks (around 127, 134, and 143 ppm) of the benzene ring (carbon number 6) in the styrene unit]/6

‧[Integrated intensity of the carbon peak (near 170ppm) of the carbonyl part (carbon number 2) in the maleic anhydride unit]/2

‧[Integrated intensity of the carbon peak (near 175ppm) of the carbonyl part (carbon number 1) in the MMA unit]/1

From the area ratio of the above value, the molar ratio of the styrene unit, the maleic anhydride unit, and the MMA unit in the sample was determined. From the obtained molar ratio and the mass ratio of each monomer unit (styrene unit: maleic anhydride unit: MMA=104:98:100), the mass composition of each monomer in the SMA resin was obtained.

<Weight average molecular weight (Mw)>

According to the following procedure, the Mw of the SMA resin is obtained by the GPC method.

Tetrahydrofuran was used as the eluent, and two of TSKgel SuperMultipore HZM-M manufactured by TOSOH Co., Ltd. and SuperHZ4000 were used as the column. The HLC-8320 (model) manufactured by TOSOH Co., Ltd. equipped with a differential refractive index detector (RI detector) was used as the GPC device. 4 mg of SMA resin was dissolved in 5 ml of tetrahydrofuran to prepare a sample solution. The temperature of the column oven was set at 40°C, 20 μl of the sample solution was injected at a flow rate of 0.35 ml/min of the eluent, and the chromatography was measured. 10 points of standard polystyrene with a molecular weight in the range of 400 to 5,000,000 were measured by GPC, and a calibration curve showing the relationship between residence time and molecular weight was prepared. Determine Mw according to this calibration curve.

The incorporation ratio (mass percentage) of the SMA resin in the resin composition (1) in the total amount of the methacrylic resin A and the SMA resin is called the SMA ratio.

[Polycarbonate]

Prepare "SD POLYCA (registered trademark) PCX" manufactured by Sumika Styron Polycarbonate Co., Ltd. (MFR at a temperature of 300°C and a load of 1.2 kg = 6.7g/10 minutes, glass transition temperature (Tg) = 150°C, coefficient of linear expansion = 6.93×10 ^-5 /K) as polycarbonate.

[Example 1]

(Method of manufacturing extruded resin board)

Methacrylic resin B (glass transition temperature: 120°C, linear expansion coefficient: 7.30×10 ^-5 /K) with a TC ratio of 20% by mass was melted in a 65mmφ single-screw extruder [manufactured by Toshiba Machine Co., Ltd.], and The polycarbonate is melted by a 150mmφ single-screw extruder [manufactured by Toshiba Machine Co., Ltd.], and the two are laminated through a multi-branch tube die. The laminated resin (extruded resin sheet 16, molten thermoplastic resin laminate) is sandwiched between the first cooling roll 12 and the second cooling roll 13 as shown in FIG. 1 and wound to the second cooling roll 13 , It is cooled by winding to the third cooling roll 14, and the extruded resin sheet 16 is produced by pulling it with the pulling roll 15. The resin temperature (TT) was adjusted to 150°C by controlling the temperature of the second cooling roll 13 and the third cooling roll 14. In addition, the circumferential speed ratio (V4/V2) of the second cooling roll 13 and the drawing roll 15 is adjusted to 0.995, and the circumferential speed ratio (V3/V2) of the second cooling roll 13 to the third cooling roll 14 is adjusted to 1.005 , The polycarbonate-containing layer side is brought into contact with the third cooling roll 14 side. The thickness of the methacrylic resin-containing layer was set to 0.075 mm, and the thickness of the polycarbonate-containing layer was set to 0.925 mm. Table 2 shows the evaluation results of the production conditions and the evaluation results of the obtained extruded resin sheet.

[Examples 2~4]

Except for using methacrylic resin B with a TC ratio described in the column of "Methacrylic resin containing layer" in Table 2 instead of methacrylic resin B with a TC ratio of 20% by mass, and the resin temperature (TT) as Except for adjusting as described in Table 2, an extruded resin sheet was produced in the same manner as in Example 1. Table 2 shows the production conditions and the evaluation results of the obtained extruded resin sheet.

[Example 5]

The resin composition (1) with an SMA ratio of 20% by mass was used instead of the methacrylic resin B with a TC ratio of 20% by mass, and as described in Table 2, an extruded resin sheet was produced in the same manner as in Example 1.

[Examples 6-15, Comparative Examples 2-6]

Except that the resin composition (1) having the SMA ratio described in the "methacrylic resin-containing layer" of Table 2 was used instead of the resin composition (1) with the SMA ratio of 20% by mass, and each was changed as described in Table 2. Except for the conditions, an extruded resin sheet was produced in the same manner as in Example 5. Table 2 shows the production conditions and the evaluation results of the obtained extruded resin sheet.

[Comparative Example 1]

Except that methacrylic resin A was used instead of methacrylic resin B with a TC ratio of 20% by mass, as described in Table 2, an extruded resin plate was produced in the same manner as in Example 1. Table 2 shows the production conditions and the evaluation results of the obtained extruded resin sheet.

Table 2 shows the type of resin or resin composition used as the layer containing methacrylic resin, resin temperature (TT), peripheral speed ratio (V3/V2), peripheral speed for each example and comparative example. Ratio (V4/V2), glass transition temperature (Tg), linear expansion coefficient of methacrylic resin-containing layer, linear expansion ratio (SR) of extruded resin sheet, initial warpage and after high temperature and high humidity, heating The measurement results of the hysteresis before and after, the rate of change of the hysteresis before and after heating, and the surface properties.

In Examples 1 to 4, a layer containing a methacrylic resin B with a TC ratio of 20 to 60% by mass and a layer containing polycarbonate were produced. The resin board was extruded for testing. As shown in Table 2, in the case of using the layer of methacrylic resin B with a TC ratio of 45% in Example 3, considering the glass transition temperature (Tg), linear expansion coefficient ratio (SR), and the amount of warpage As well as the hysteresis value and rate of change, this is the best result.

In Examples 5 to 14, an extruded resin sheet in which a layer containing a resin composition (1) having an SMA ratio of 20 to 100% by mass and a polycarbonate-containing layer were laminated was produced and tested. As shown in Table 2, when the layer of the resin composition (1) containing 70% by mass of SMA of Examples 7 and 9 was used, the hysteresis value and the rate of change were good, and the absolute value of the warpage was also small. This is the best result.

In addition, in Examples 1 to 9, the peripheral velocity ratio (V4/V2) was constant at 0.995.

In Examples 10-14, a layer containing a resin composition (1) with an SMA ratio of 70% by mass was used, the resin temperature (TT) was fixed at 155°C, and the peripheral speed ratio (V4/V2) was set at 0.98 to 1.01 .

On the other hand, in Comparative Example 1, the glass transition temperature (Tg) was low, but the warpage after high temperature and high humidity was large. In Comparative Examples 2 and 3, after lowering the resin temperature (TT), an extruded resin sheet with a large amount of warpage was obtained, and the rate of decrease in the in-plane hysteresis value before and after heating was large.

In Comparative Example 4, after raising the resin temperature (TT), it became an extruded resin sheet with poor surface properties. In Comparative Example 5, after increasing the peripheral speed ratio (V4/V2), it became an extruded resin sheet with a high hysteresis value. In Comparative Example 6, after lowering the peripheral speed ratio (V4/V2), it became an extruded resin sheet with a low hysteresis value.

[Industrial availability]

Examples of extruded resin sheets obtained by the manufacturing method of the present invention For example, it can be used as a protective cover for LCD protection panels or touch panels, and is suitable for automotive display devices, mobile phones, smart phones, computers, TVs, etc.

In addition, the present invention is not limited to the embodiment described above, and can be appropriately modified within a range that does not deviate from the gist.

Claims (15)

A method for manufacturing an extruded resin sheet, which is a method for manufacturing an extruded resin sheet in which a layer containing methacrylic resin is laminated on at least one surface of a layer containing polycarbonate, wherein the layer containing methacrylic resin The glass transition temperature is 115°C or higher. The manufacturing method includes the following steps: in a molten state, the thermoplastic resin laminate in which the methacrylic resin-containing layer is laminated on at least one surface of the polycarbonate-containing layer is obtained from T-die extrusion, sandwich the thermoplastic resin laminate between the first cooling roll and the second cooling roll, and wind the thermoplastic resin laminate to the second cooling roll and then to the third cooling roll. After cooling, the thermoplastic resin laminate is pulled by a pull roll; at the position where the thermoplastic resin laminate is peeled from the last cooling roll wound, the temperature of the entire resin is set relative to the glass of the polycarbonate-containing layer The transition temperature is in the range of -2°C to +15°C, and the peripheral speed ratio (V4/V2) of the peripheral speed (V4) of the pulling roll and the peripheral speed (V2) of the second cooling roll (V4/V2) is set to 0.98 or more and 1.01 the following. The method for manufacturing an extruded resin sheet according to claim 1, wherein the difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer ), the ratio ((S2-S1)/S1) to the linear expansion coefficient (S1) of the polycarbonate-containing layer is -10%~+5%. The method for manufacturing an extruded resin sheet according to claim 1 or 2, wherein the methacrylic resin-containing layer contains 40 to 80% by mass of structural units derived from methyl methacrylate and is represented by the following general formula (I) The structural unit of methacrylate is 20-60% by mass;

(In the formula, Cy represents an alicyclic hydrocarbon group). The method for manufacturing an extruded resin sheet according to claim 3, wherein Cy in the general formula (I) is a polycyclic aliphatic hydrocarbon group. The method for producing an extruded resin sheet according to claim 1 or 2, wherein the layer containing methacrylic resin contains: methacrylic resin 5 mass% or more and less than 80 mass%, and containing from the following general formula (II) 20% by mass or more of a copolymer composed of structural units of the aromatic vinyl compound and structural units derived from the acid anhydride represented by the following general formula (III);

(In the formula: R ¹ and R ² each independently represent a hydrogen atom or an alkyl group);

(In the formula: R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group). The method for manufacturing an extruded resin sheet of claim 5, wherein the copolymer contains There are 50 to 84% by mass of the structural unit derived from the aromatic vinyl compound, 15 to 49% by mass of the structural unit derived from the acid anhydride, and 1 to 25% by mass of the methacrylate monomer. The method for manufacturing an extruded resin sheet according to claim 6, wherein the methacrylate monomer is methyl methacrylate. An extruded resin sheet, which is an extruded resin sheet obtained by the manufacturing method of any one of claims 1 to 7, wherein the extruded resin sheet is heated at 75°C for 5 hours. In at least a part of the width direction before and after, the in-plane hysteresis value is 50 to 600 nm, and the rate of decrease of the hysteresis value before and after the heating is less than 15%. An extruded resin sheet, which is an extruded resin sheet obtained by the manufacturing method of any one of claims 1 to 7, wherein the extruded resin sheet is heated at 100°C for 5 hours. In at least a part of the width direction before and after, the in-plane hysteresis value is 50 to 600 nm, and the rate of decrease of the hysteresis value before and after the heating is less than 15%. An extruded resin sheet, which is an extruded resin sheet obtained by the manufacturing method according to any one of claims 1 to 7, wherein the extruded resin sheet is heated at 75°C to 100°C for 5 hours In at least a part of the width direction before and after heating, the in-plane hysteresis value is 50 to 600 nm, and the rate of decrease of the hysteresis value before and after heating is less than 15%. The extruded resin sheet according to any one of claims 8 to 10, wherein in at least a part of the width direction before and after the heating, the in-plane hysteresis value is 80 ~350nm. The extruded resin sheet according to any one of claims 8 to 10, wherein the reduction rate of the hysteresis value before and after the heating is less than 10%. The extruded resin sheet according to any one of claims 8 to 10, which is further provided with a scratch-resistant layer on at least one surface. A method for manufacturing an extruded resin board, which is obtained by the manufacturing method as claimed in any one of claims 1 to 7, and further comprises heating the extruded resin board at a temperature of 65°C to 110°C In the step of heating for 1 to 30 hours, in at least a part of the width direction before and after the heating, the in-plane hysteresis value is 50 to 600 nm, and the rate of decrease of the hysteresis value before and after the heating is less than 15%. An extruded resin sheet, which is an extruded resin sheet in which a layer containing methacrylic resin is laminated on at least one side of a layer containing polycarbonate, wherein the glass transition temperature of the layer containing methacrylic resin is 115 ℃ or higher, when heating at 75℃ for 5 hours, in at least a part of the width direction before and after heating, the in-plane hysteresis value is 50~600nm, and the rate of decrease of the hysteresis value before and after heating is less than 15% The difference (S2-S1) between the linear expansion coefficient (S1) of the carbonate layer and the linear expansion coefficient (S2) of the methacrylic resin-containing layer, and the linear expansion coefficient (S1) of the polycarbonate-containing layer The ratio ((S2-S1)/S1) is -10%~+5%.

Images