TW201618930A - Method for manufacturing extruded resin plate and extruded resin plate - Google Patents

Abstract

The present invention provides a process for producing a resin sheet which has satisfactory surface properties and is inhibited from suffering warpage due to residual stress. The ratio of the difference between the coefficient of linear expansion (S1) of a polycarbonate-containing layer and the coefficient of linear expansion (S2) of a methacrylic-resin-containing layer to the coefficient of linear expansion (S1) of the polycarbonate-containing layer, (S2-S1)/S1, is regulated to -10% to +5%. The glass transition temperature of the methacrylic-resin-containing layer is regulated to 120-160 DEG C. A thermoplastic resin laminate (resin sheet (16)) comprising the polycarbonate-containing layer and the methacrylic-resin-containing layer laminated thereto is extruded in a molten state through a T die (11), is sandwiched between first and second cooling rolls (12, 13), is wound on the second cooling roll (13), is then wound on a third cooling roll (14) to cool the sheet, and is hauled with hauling rolls (15). At the position where the resin sheet (16) separates from the third cooling roll (14), the temperature of the entire resin is regulated so as to be higher by 0-15 DEG C than the glass transition temperature of the polycarbonate-containing layer.

Description

Method for manufacturing extruded resin sheet and extruded resin sheet

The present invention relates to a resin sheet. More specifically, the present invention relates to a method for producing a resin sheet comprising a layer containing a methacrylic resin and a layer containing a polycarbonate, which has good surface characteristics and can suppress warpage caused by residual stress. The song is suitable for the protective cover of the touch panel.

The touch panel (or touch screen) is an electronic component that combines the display device with the position input device. The electronic device can be operated by touching the touch panel with a finger or a pen. The touch panel can be used for ATMs, vending machines, mobile phones, personal digital assistants (PDAs), digital audio players, portable game consoles, tablet computers, photocopiers, fax machines, car navigation systems for financial institutions such as banks. Digital information equipment, etc.

There is a surface scratch or internal crush due to the input operation of the touch panel. In order to prevent this, a transparent protective cover is provided on the surface of the touch panel. As a protective casing, tempered glass products are mainly used. Moreover, from the viewpoint of workability and weight reduction, development of a transparent resin protective casing has been carried out. For the protective casing, gloss, scratch resistance, impact resistance, and the like are required.

Further, polycarbonate is one of resins suitable for obtaining a molded article excellent in impact resistance. The methacrylic resin is one of resins suitable for obtaining a molded article having high gloss and scratch resistance. Further, by simultaneously performing heat-melt molding (for example, co-extrusion molding) of a polycarbonate and a methacrylic resin, a resin sheet including "a layer containing a polycarbonate" and a "layer containing a methacrylic resin" can be produced. . In the heat-melting molding of such a resin sheet, a large amount of strain stress remains in the obtained molded article due to the difference in characteristics of the two resins. The strain stress remaining in the molded article is referred to as residual stress, and the molded article having the residual stress is warped or shrunk due to heat or the like.

In the plate-shaped molded article such as the above resin sheet, warpage due to residual stress is a problem in particular. As one of the methods for reducing the residual stress in the sheet-like molded article to suppress the occurrence of warpage, a method of adjusting the rotational speed of the cooling drum for extrusion molding is known (for example, refer to Patent Document 1).

Further, in order to solve this problem, it is considered to improve the heat resistance and moisture resistance of the methacrylic resin. For example, it has been proposed to use a unit having a methyl methacrylate unit selected from the group consisting of a methacrylic acid unit, an acrylic acid unit, a maleic anhydride unit, an N-substituted or unsubstituted maleimide unit, a glutaric anhydride structural unit, and a pentanediol. A methacrylic resin having a glass transition temperature of 110° C. or higher, and a first layer, and a double-layer resin sheet including a layer of polycarbonate thereon (for example, refer to Patent Document 2) . However, even in this case, the heat resistance and moisture resistance of the methacrylic resin of the resin sheet are insufficient, and the above problems cannot be sufficiently solved even if it is provided.

Moreover, in order to solve this problem, a method of controlling the occurrence of warpage by reducing the difference in linear expansion coefficients between the two resin sheets has been known (for example, refer to Patent Document 3). However, only defining the coefficient of linear expansion does not solve the above problem.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2007-185956

Patent Document 2 Japanese Patent Laid-Open Publication No. 2009-248416

Patent Document 3 Japanese Patent Laid-Open Publication No. 2007-118597

In the resin sheet, the degree of stress remaining in each resin layer varies. Therefore, it is possible to reduce the residual stress by adjusting the rotational speed of the cooling drum for extrusion molding. However, when the molded article is peeled off from the cooling drum, the surface of the molded article has a stripe-like defect called a chatter mark, and the surface property is lowered. This has become a problem in that the resin sheet is used for a protective case of a touch panel.

An object of the present invention is to provide a method for producing a resin sheet which is excellent in surface characteristics and which can suppress warpage caused by residual stress, and a resin sheet.

In order to achieve the above object, the inventors of the present invention have found that the present invention includes the following aspects.

That is, the present invention encompasses the following aspects.

In one aspect of the method for producing an extruded resin sheet of the present invention (hereinafter, "extruded resin sheet" is referred to as "resin sheet" as appropriate), a layer containing a layer of polycarbonate contains a layer containing methacrylic acid. A method of producing an extruded resin sheet of a resin layer, which performs the following steps.

In the molten state, a step of extruding a thermoplastic resin laminate having a layer containing a methacrylic resin on a single side of a layer containing a polycarbonate from a T-die.

The thermoplastic resin laminate is sandwiched between the first cooling drum and the second cooling drum.

After the thermoplastic resin laminate is wound around the second cooling drum, it is wound around the third cooling drum to perform cooling.

The step of winding the thermoplastic resin laminate by a winding drum.

In addition, the following requirements must be met in each of the above steps.

The difference (S2-S1) between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the layer containing the methacrylic resin, and the line of the polycarbonate-containing layer The ratio of the expansion coefficient (S1) ((S2-S1)/S1) is -10% to +5%. Hereinafter, the ratio ((S2-S1)/S1) is appropriately described as "linear expansion ratio (SR)".

The glass transition temperature of the layer containing the methacrylic resin was 120 to 160 °C.

At the position where the thermoplastic resin laminate is peeled off from the third cooling drum, the overall temperature of the resin is in the range of 0 ° C to + 15 ° C with respect to the glass transition temperature (Tg) of the polycarbonate.

By satisfying these requirements, a resin sheet having good surface characteristics and small warpage due to residual stress can be realized.

Moreover, in one aspect of the resin sheet obtained by the method for producing an extruded resin sheet, the layer containing the methacrylic resin preferably contains 40 to 80% by mass of a structural unit derived from methyl methacrylate. It contains 20 to 60% by mass of a structural unit derived from a methacrylate represented by the following formula (I).

(wherein Cy represents an alicyclic hydrocarbon group).

Further, Cy in the general formula (I) is more preferably a polycyclic aliphatic hydrocarbon group.

Further, in one aspect of the resin sheet obtained by the method for producing an extruded resin sheet, the layer containing the methacrylic resin preferably contains less than 80% by mass of a methacrylic resin, and at least 20% by mass or more. A copolymer comprising a structural unit derived from an aromatic vinyl compound represented by the following formula (II) and a structural unit derived from an acid anhydride represented by the following formula (III).

(wherein R ¹ and R ² each independently represent a hydrogen atom or an alkyl group).

(wherein R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group).

Further, the copolymer contains 50 to 84% by mass of a structural unit derived from the aromatic vinyl compound, and contains 15 to 49% by mass of a structural unit derived from the acid anhydride, and contains 1 to 25% by mass of a methacrylate monomer. Preferably, the methacrylate monomer is methyl methacrylate being even more preferred.

Preferably, the resin sheet has a scratch-resistant layer on at least one surface.

The resin sheet of the present invention has excellent surface characteristics and can suppress warpage due to residual stress. Further, the resin sheet of the present invention is intended to have gloss, scratch resistance and impact resistance, and is suitable, for example, for a touch panel protective case.

11‧‧‧T-model

12‧‧‧1st cooling drum

13‧‧‧2nd cooling roller

14‧‧‧3rd cooling roller

15‧‧‧ winding drum

16‧‧‧resin board

Fig. 1 is a view showing a method of producing a resin sheet formed by co-extrusion in an embodiment of the present invention.

Form for 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 description and drawings are omitted and simplified as appropriate. In the drawings, the components and the equivalent components having the same configurations or functions are denoted by the same reference numerals, and the description thereof will be omitted.

Embodiment 1

In the resin sheet according to the present invention, a layer containing a methacrylic resin layer is laminated on one side of a layer containing a polycarbonate (hereinafter also referred to as "polycarbonate-containing layer" as appropriate) (hereinafter also referred to as "A" The acrylic resin contains a layer").

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

By producing a resin sheet by an extrusion molding method, the production efficiency is excellent.

In the resin sheet, the linear expansion ratio (SR) expressed by the relationship between the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient (S2) of the layer containing the methacrylic resin is -10. In the range of %~+5%, the linear expansion ratio (SR) is preferably in the range of -5% to +2% from the viewpoint of obtaining good warpage.

The linear expansion ratio (SR) is the difference between the coefficient of linear expansion (S1) of the layer containing polycarbonate and the coefficient of linear expansion (S2) of the layer containing the methacrylic resin (S2-S1) and the coefficient of linear expansion (S1). Ratio ((S2-S1)/S1). In other words, in the present specification, the linear expansion ratio (SR) is a calculation formula ((S2-S1)/S1) indicating the linear expansion coefficient (S1) of the polycarbonate-containing layer and the linear expansion coefficient of the methacrylic resin-containing layer. The ratio of the relationship of (S2).

Further, the lower limit of the glass transition temperature (Tg) of the resin constituting the layer containing the methacrylic resin is generally 120 ° C, preferably 125 ° C, more preferably 130 ° C, and the upper limit of the glass transition temperature (Tg) is generally 160 ° C, preferably 155 ° C, more preferably 150 ° C. When the linear expansion ratio (SR) and the glass transition temperature (Tg) of the layer containing the methacrylic resin are within this range, the surface characteristics are good, and the warpage due to the residual stress is small, which is preferable.

[methacrylic resin]

In one embodiment of the invention, the methacrylic resin contains structural units derived from methacrylate.

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. It can also be 100% by mass. When the content of the structural unit derived from methacrylate is within the above range, the transparency is good.

The methacrylate is represented by the formula (IV).

In the 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 or a propyl group, or may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group such as a phenyl group. Here, when R is an alicyclic hydrocarbon group, the methacrylate is represented by the formula (I). Hereinafter, the methacrylate represented by the formula (I) is appropriately referred to as "methacrylate (I)".

Examples of the methacrylate (I) include a methacrylic monocyclic aliphatic hydrocarbon ester such as cyclohexyl methacrylate, cyclopentyl methacrylate or cycloheptyl methacrylate; Oxime ester, 2-methyl-2-norbornyl methacrylate, 2-ethyl-2-norbornyl methacrylate, 2-isodecyl methacrylate, 2-methyl-2-methacrylate Isodecyl ester, 2-ethyl-2-isodecyl methacrylate, 8-tricyclo[5.2.1.0 ^2,6 ]decyl methacrylate, 8-methyl-8-tricyclomethacrylate [5.2 .1.0 ^2,6 ]decyl ester, 8-ethyl-8-tricyclo[ ² -methyl]-tricyclo[2-propanoate, 2-adamantyl methacrylate, 2-methyl-2 methacrylate -adamantyl ester, 2-ethyl-2-adamantyl methacrylate, 1-adamantyl methacrylate, 2-decyl methacrylate, 2-methyl-2-decyl methacrylate or A polycyclic aliphatic hydrocarbon methacrylate such as 2-ethyl-2-nonyl acrylate or the like. Among them, a polycyclic aliphatic hydrocarbon methacrylate is preferred, and 8-tricyclo[5.2.1.0 ^2,6 ]nonyl methacrylate is more preferred.

The methacrylic resin to be used in the present invention preferably comprises a structural unit derived from methyl methacrylate (hereinafter referred to as "MMA" as appropriate) and a structural unit derived from methacrylate (I), more preferably A structural unit derived from methyl methacrylate and a structural unit derived from a polycyclic aliphatic hydrocarbon ester of methacrylic acid, and more preferably a structural unit derived from methyl methacrylate and derived from methacrylic acid 8- A structural unit of tricyclo[5.2.1.0 ^2,6 ]decyl ester.

The methacrylic resin to be used in the present invention preferably contains 40 to 80% by mass of a structural unit derived from methyl methacrylate, more preferably 50 to 80% by mass, more preferably from the viewpoint of hardness. It is contained in an amount of 50 to 60% by mass.

The methacrylic resin used in the present invention has a glass transition temperature (Tg) of 120 ° C from the viewpoint of making the linear expansion ratio (SR) small. From the above viewpoints, it is preferred to contain 20 to 60% by mass of the structural unit derived from the methacrylate (I), more preferably 20 to 50% by mass, still more preferably 40 to 50% by mass. When the structural unit derived from the methacrylate (I) exceeds 60% by mass, the impact resistance of the methacrylic resin layer tends to be lowered.

The methacrylic resin used in the present invention can be obtained by polymerizing the above methacrylate and other monomers of any component. In the case of using a plurality of monomers in the polymerization, the plurality of monomers are generally mixed to prepare a monomer mixture, and then supplied to the polymerization. The polymerization method is not particularly limited, and from the viewpoint of productivity, it is preferred to carry out radical polymerization by a method such as a bulk polymerization method, a suspension polymerization method, a solution polymerization method or an emulsion polymerization method.

The weight average molecular weight (hereinafter referred to as "Mw" as appropriate) used in the methacrylic resin of the present invention is preferably 40,000 to 500,000. When the Mw is 40,000 or more, the resin sheet of the present invention is excellent in scratch resistance and heat resistance, and when it is 500,000 or less, the moldability is excellent, and the productivity of the resin sheet of the present invention can be improved.

Further, in the present specification, Mw means a standard polystyrene equivalent value measured by gel permeation chromatography (GPC).

In one embodiment of the present invention, the resin constituting the layer containing the methacrylic resin contains less than 80% by mass of the methacrylic resin and 20% by mass or more of at least the formula (II) derived from the following formula (II). A structural unit of an aromatic vinyl compound (hereinafter referred to as "aromatic vinyl compound (II)") and a structural unit derived from an acid anhydride represented by the following formula (III) (hereinafter referred to as "anhydride (III)")) Copolymer A resin composition (hereinafter referred to as "resin composition (1)") is appropriately described as "SMA resin".

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

(wherein 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 methacrylate.

Examples of the methacrylate include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and isobutyl methacrylate. Tert-butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, decyl methacrylate, methyl An alkyl methacrylate such as dodecyl acrylate; an aryl methacrylate represented by the above-mentioned methacrylate (I); an aryl methacrylate such as phenyl methacrylate; Acrylate methacrylate such as benzyl acrylate, etc. From the viewpoints, preferred are MMA, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and t-butyl methacrylate. The best is 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, and may be only derived from methacrylic acid. The structural unit of the ester.

In addition, the methacrylic resin contained in the resin composition (1) preferably contains 90% by mass or more of a structural unit derived from MMA, more preferably 95% by mass or more, and furthermore. It is preferably 98% by mass or more, and may be only a structural unit derived from MMA.

Further, the methacrylic resin contained in the resin composition (1) may contain a structural unit derived from a monomer other than methacrylate. Examples of the other monomer include methyl acrylate (hereinafter referred to as "MA" as appropriate), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and third butyl acrylate. Ester, hexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxy acrylate Butyl ester, cyclohexyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, trifluoromethyl acrylate, trifluoroethyl acrylate, pentafluoroethyl acrylate, glycidyl acrylate, acrylonitrile An acrylate such as propyl ester, phenyl acrylate, toluene acrylate, benzyl acrylate, isodecyl acrylate or 3-dimethylaminoethyl acrylate is preferably MA or ethyl acrylate from the viewpoint of availability. , n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, The acrylate such as isobutyl acrylate or tributyl acrylate is more preferably MA or ethyl acrylate, and most preferably MA. The total content of the structural unit derived from the other monomer in the methacrylic resin is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less.

The methacrylic resin contained in the resin composition (1) can be obtained by polymerizing the above methacrylate and other monomers of any component. In the case of using a plurality of monomers in the polymerization, the plurality of monomers are generally mixed to prepare a monomer mixture, and then supplied to the polymerization. The polymerization method is not particularly limited, and from the viewpoint of productivity, it is preferred to carry out radical polymerization by a method such as a bulk polymerization method, a suspension polymerization method, a solution polymerization method or an emulsion polymerization method.

The weight average molecular weight (hereinafter referred to as "Mw" as appropriate) of the methacrylic resin contained in the resin composition (1) is preferably 40,000 to 500,000. When the Mw is 40,000 or more, the resin sheet of the present invention is excellent in scratch resistance and heat resistance, and when it is 500,000 or less, the resin composition (1) is excellent in moldability, and the resin of the present invention can be further improved. The productivity of the board.

The content of the SMA resin used in the resin composition (1) of the present invention is preferably from the viewpoint of reducing the linear expansion ratio (SR) and the glass transition temperature (Tg) of 120 ° C or higher. 20% by mass or more, more preferably 45% by mass or more and less than 95% by mass, still more preferably 50% by mass or more and less than 90% by mass.

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

The alkyl group independently represented by R ¹ and R ² in the formula (II) and R ³ and R ⁴ in the formula (III) is preferably a methyl group, an ethyl group, a n-propyl group or an isopropyl group. N-butyl, t-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, decyl, An alkyl group having a carbon number of 12 or less, such as a mercapto group or a dodecyl group, more preferably a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, an isobutyl group or a t-butyl group. An alkyl group having 4 or less carbon atoms.

R ^{1 is} preferably a hydrogen atom, a methyl group, an ethyl group and a third butyl group. R ² , R ³ and R ^{4 are} preferably a hydrogen atom, a methyl group or 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, still more preferably 60 to 80% by mass. . When the content is in the range of 50 to 85% by mass, the resin composition (1) is excellent in moisture resistance and transparency.

Examples of the aromatic vinyl compound (II) include styrene; 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, and 4-tert-butylbenzene. Alkyl-substituted styrene such as ethylene; α-alkyl-substituted styrene such as α-methylstyrene or 4-methyl-α-methylstyrene; from the viewpoint of availability, benzene is preferred. Ethylene. These aromatic vinyl compounds (II) may be used alone or in combination of two or more.

The content of the structural unit derived from the acid anhydride (III) in the SMA resin is preferably in the range of 15 to 50% by mass, more preferably in the range of 18 to 45% by mass, still more preferably in the range of 20 to 40% by mass. When the content is in the range of 15 to 50% by mass, the resin composition (1) is excellent in heat resistance and transparency.

Examples of the acid anhydride (III) include maleic anhydride, citraconic anhydride, and dimethyl maleic anhydride. From the viewpoint of availability, maleic anhydride is preferred. These acid anhydrides (III) may be used alone or in combination of two or more.

The SMA resin preferably contains a structural unit derived from a methacrylate monomer in addition to the aromatic vinyl compound (II) and the acid anhydride (III). 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, still more preferably 5 to 26% by mass. range. When the content is in the range of 1 to 35% by mass, the bending workability and the transparency are excellent.

Examples of the methacrylate include MMA, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, propyl methacrylate, and isopropyl methacrylate. N-butyl methacrylate, isobutyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 1-phenylethyl methacrylate and the like. Among these methacrylates, an alkyl methacrylate having an alkyl group having 1 to 7 carbon atoms is preferred, and from the viewpoint of excellent heat resistance and transparency of the obtained SMA resin, MMA is particularly preferred. . Further, the methacrylate may be used singly or in combination of two or more.

The SMA resin may have a structural unit derived from a monomer other than the aromatic vinyl compound (II), the acid anhydride (III), and the methacrylic ester. Examples of the other monomer include MA, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, and 2-ethyl acrylate. Hexyl ester, decyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, cyclohexyl acrylate, acrylic acid 2- Methoxyethyl ester, 3-methoxybutyl acrylate, trifluoromethyl acrylate, trifluoroethyl acrylate, pentafluoroethyl acrylate, glycidyl acrylate, allyl acrylate, phenyl acrylate, toluene acrylate, An acrylate such as benzyl acrylate, isodecyl acrylate or 3-dimethylaminoethyl acrylate. These other monomers may be used alone or in combination of two or more. In the SMA resin, the content of the structural unit derived from the other monomer is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less.

The SMA resin can be obtained by polymerizing the aromatic vinyl compound (II), the acid anhydride (III), a methacrylate, and another monomer having an optional component. In the polymerization, the monomers used are generally mixed to prepare a monomer mixture, and then supplied to the polymerization. The polymerization method is not particularly limited, and from the viewpoint of productivity, it is preferred to carry out radical polymerization by a method such as a bulk polymerization method or a solution polymerization method.

The Mw of the above SMA resin is preferably in the range of 40,000 to 300,000. When the Mw is 40,000 or more, the resin sheet of the present invention is excellent in scratch resistance and impact resistance, and when it is 300,000 or less, the moldability is excellent, and the productivity of the resin sheet of the present invention can be improved.

The resin composition (1) is obtained by mixing the above methacrylic resin and SMA resin. For the mixing, for example, a melt mixing method, a solution mixing method, or the like can be used. The melt mixing method uses, for example, a uniaxial or multiaxial kneader, an open roll, a Banbury closed mixer, and a kneading machine. The melt kneading machine is melt-kneaded in an inert gas atmosphere such as nitrogen, argon or helium in response to demand. In the solution mixing method, a methacrylic resin and an SMA resin are dissolved in an organic solvent such as toluene, tetrahydrofuran or methyl ethyl ketone and mixed.

The resin constituting the layer containing the methacrylic resin according to an embodiment of the present invention may contain a polymer other than the methacrylic resin and the SMA resin, within a range not impairing the effects of the present invention. Examples of the other polymer include polyolefins such as polyethylene and polypropylene, polyamine, polyphenylene sulfide, polyetheretherketone, polyester, polyfluorene, polyoxyxylene, polyimine, and poly. A thermoplastic resin such as an ether quinone or a polyacetal; a thermosetting resin such as a phenol resin, a melamine resin, a fluorene resin or an epoxy resin; an acrylic rubber such as a multilayer structure particle or a block copolymer. These other polymers may be used alone or in combination of two or more.

In the resin constituting the layer containing the methacrylic resin according to the embodiment of the present invention, the content of the other polymer is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass. %the following.

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

When the resin composition (1) contains other polymers and/or additives, it may be added during the polymerization of the methacrylic resin and/or the SMA resin, or may be added when the methacrylic resin and the SMA resin are mixed, or may be mixed. Add methacrylic resin and SMA resin.

The resin constituting the layer containing the methacrylic resin used in one embodiment of the present invention may contain various additives as needed. Examples of the additive include an antioxidant, a thermal degradation inhibitor, an ultraviolet absorber, a light stabilizer, a lubricant, a mold release agent, a polymer processing aid, an antistatic agent, a flame retardant, and a dye. Pigments, light diffusers, matting agents, impact modifiers, phosphors, etc. The content of the additives can be appropriately set within a range that does not impair the effects of the present invention, and the content of the antioxidant is, for example, 0.01 to 1 part by mass based on 100 parts by mass of the resin constituting the layer containing the methacrylic resin. The content of the ultraviolet absorber is 0.01 to 3 parts by mass, the content of the light stabilizer is 0.01 to 3 parts by mass, the content of the lubricant is 0.01 to 3 parts by mass, and the dye. The content of the pigment is preferably from 0.01 to 3 parts by mass.

The resin constituting the layer containing the methacrylic resin according to the embodiment of the present invention preferably has a melt flow rate (hereinafter referred to as "MFR" as appropriate) in the range of 1 to 10 g/10 min, more preferably 1.5~. The range of 7 g/10 minutes, more preferably 2 to 4 g/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.

Further, the MFR of the resin constituting the layer containing the methacrylic resin in the present specification is a value measured by a melt indexer at a temperature of 230 ° C and a load of 3.8 kg.

[polycarbonate]

The polycarbonate used in the laminate of the present invention is preferably obtained by copolymerizing a dihydric phenol with a carbonate precursor.

Examples of the above dihydric phenol include 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 1,1-bis(4-hydroxyphenyl)ethane, and 1,1-double ( 4- Hydroxyphenyl)cyclohexane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, double (4-Hydroxyphenyl) sulfide, bis(4-hydroxyphenyl)fluorene, etc., of which bisphenol A is preferred. These dihydric phenols may be used alone or in combination of two or more.

Examples of the carbonate precursor include a carbonyl halide such as dicarbonyl chloride, a carbonate such as diphenyl carbonate, and a haloformate such as a dihaloformate of a dihydric phenol. These carbonate precursors may be used alone or in combination of two or more.

The method for producing the above polycarbonate is not particularly limited, and examples thereof include an interfacial polymerization method in which an aqueous solution of a dihydric phenol and an organic solvent solution of a carbonate precursor are reacted at an interface, or a dihydric phenol and a carbonate precursor are placed. The transesterification method in which the reaction is carried out under high temperature, reduced pressure, and no solvent conditions.

The Mw of the above polycarbonate is preferably in the range of 10,000 to 100,000, more preferably in the range of 20,000 to 70,000. When the Mw is 10,000 or more, the laminate of the present invention is excellent in impact resistance and heat resistance, and when it is 100,000 or less, the molding processability of polycarbonate is excellent, and the production of the laminate of the present invention can be further improved. Sex.

The above polycarbonate may contain other polymers insofar as the effects of the present invention are not impaired. As the other polymer, the same as the other polymer which can be contained in the methacrylic resin, the resin composition (1), and the above resin composition (1) can be used. These other polymers may be used alone or in combination of two or more. The content of the other polymers in the polycarbonate is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less.

The above polycarbonate may also contain various additives as needed. As the additive, the same ones as those which can be contained in the resin constituting the layer containing the methacrylic resin can be used. The content of the additives can be appropriately set within a range that does not impair the effects of the present invention, and the content of the antioxidant is 0.01 to 1 part by mass, and the content of the ultraviolet absorber is 0.01 to 3 with respect to 100 parts by mass of the polycarbonate. The mass fraction, the content of the light stabilizer is 0.01 to 3 parts by mass, and the content of the lubricant is 0.01 to 3 parts by mass, the dye. The content of the pigment is preferably from 0.01 to 3 parts by mass.

When the polycarbonate contains another polymer and/or an additive, it may be added during the copolymerization of the dihydric phenol and the carbonate precursor, or may be added after the completion of the copolymerization and melt-kneaded.

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

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

Further, the MFR of the polycarbonate in the present specification was measured using a melt indexer under the conditions of a temperature of 300 ° C and a load of 1.2 kg.

A commercially available product can be used as the above-mentioned polycarbonate. For example, "CALIBRE (registered trademark)" and "SD POLYCA (registered trademark)" by Sumika Styron Polycarbonate Co., Ltd., and "IUPILON" by Mitsubishi Engineering Plastics Co., Ltd. are preferably used. /NOVAREX (registered trademark), Idemitsu Trading Co., Ltd. "TARFLON (registered trademark)", "Panlite (registered trademark)" manufactured by Teijin Chemicals Co., Ltd., etc.

[Thickness of Resin Plate]

The resin sheet according to an embodiment of the present invention preferably has a thickness of 0.1 to 2 mm, more preferably 0.5 to 1.5 mm. If it is too thin, it tends to be insufficient in rigidity. If it is too thick, it tends to hinder the weight reduction of a liquid crystal display device or the like.

The thickness of the methacrylic resin-containing layer of the resin sheet in one embodiment of the present invention is preferably 20 to 200 μm. When it is this range, the balance of scratch resistance and impact resistance is excellent. More preferably, it is 25 to 150 μm, and even more preferably 30 to 100 μm.

The thickness of the layer containing polycarbonate is preferably 0.1 to 2 mm, more preferably 0.5 to 1.5 mm. If it is too thin, there is a tendency that the impact resistance is insufficient. If it is too thick, it tends to hinder the weight reduction of a liquid crystal display device or the like.

A resin sheet obtained by an embodiment of the present invention may be provided with a cured film on at least one surface thereof. By providing a hardened film, it is possible to impart functions such as scratch resistance and low reflectivity.

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

Further, for example, the thickness of the low-reflective cured film is preferably from 80 to 200 nm, more preferably from 100 to 150 nm. Because it is too thin or too thick, the low reflection performance becomes insufficient.

[manufacturing steps]

A resin sheet according to an embodiment of the present invention is produced by co-extrusion. The resin constituting the layer containing the polycarbonate and the methacrylic resin is heated and melted, and the thermoplastic resin laminate having a layer containing the methacrylic resin laminated on at least one side of the layer containing the polycarbonate is melted. In the state, it is extruded from a wide discharge port called a T-shaped mold, and is sandwiched by a pair of rolls including a first cooling roll and a second cooling roll to form a sheet shape. After that, the thermoplastic resin laminate is wound around the second cooling drum, and then wound around the third cooling drum to be cooled. Further, the thermoplastic resin laminate (resin plate 16) is cooled by a cooling drum.

Fig. 1 shows an outline of a method for producing a resin sheet according to an embodiment, which is formed by a co-extrusion apparatus including a T-die 11 and first and third cooling rolls 12 to 14 and a winding drum 15. The pair of rolls including the first cooling roll 12 and the second cooling roll 13 sandwich the resin extruded from the T-die 11 to form a sheet-like resin plate 16. Thereafter, the resin sheet 16 is cooled by the third cooling drum 14, and then wound by a winding drum 15 including a pair of rolls. A drum may be additionally provided between the third cooling drum and the winding drum. Further, the present invention is not limited to this form.

As a method of the T-type mold in this case, a feed block type of methacrylic resin and polycarbonate which are laminated and heated in a molten state before flowing into the T-shaped mold can be used; a methacrylic resin is laminated in the T-shaped mold and A multi-manifold type of polycarbonate or the like. From the viewpoint of improving the smoothness of the interface between the layers constituting the resin sheet, a multi-split type is preferable.

In addition, as the polishing roll in this case, a metal roll or an elastic roll (hereinafter sometimes referred to as a metal elastic roll) having a metal film on the outer peripheral portion may be used. The metal drum is not particularly limited as long as it has high rigidity, and examples thereof include a drill roll and a spiral roll. The surface state of the metal roller is not particularly limited, and may be, for example, a mirror surface, or may have a pattern, a concavity, or the like. The metal elastic roller includes, for example, a substantially cylindrical shaft roller that is rotatably provided, a cylindrical metal film that is disposed to cover the peripheral edge of the shaft roller and that is in contact with the sheet-like thermoplastic resin, and is sealed to the same. The fluid between the shaft roller and the metal film, and the metal elastic roller exhibits elasticity by the fluid. The shaft roller is not particularly limited, and includes, for example, stainless steel or the like. The metal film contains, for example, stainless steel or the like, and its thickness is preferably about 2 to 5 mm. The metal film preferably has flexibility or flexibility, and is preferably a seamless structure without a welded joint portion. The metal elastic roller having such a metal film is excellent in durability, and if the metal film is mirror-finished, the same treatment as that of a general mirror roll can be performed, and when a metal film pattern or unevenness is imparted, it can be transferred. The shape of the roller, so the usability is good.

The resin and the polycarbonate constituting the layer containing the methacrylic resin are preferably melt-filtered by a filter before and after multilayer molding. By performing multilayer molding using each of the melt-filtered resin compositions, a resin sheet having less defects due to foreign matter or gel can be obtained. The filter medium of the filter to be used is not particularly limited, and can be appropriately selected by using temperature, viscosity, and filtration precision, and for example, a nonwoven fabric composed of polypropylene, cotton, polyester, enamel, glass woven fabric, or the like can be used; The resin is impregnated with a sheet of cellulose; the metal fiber is not woven a sintered sheet of cloth; a sintered sheet of metal powder; a wire mesh; or used in combination with the components. Among them, from the viewpoint of heat resistance and durability, it is preferred to use a plurality of sheets of metal fiber nonwoven fabric sintered sheets to be used.

The filtration accuracy of the filter is not particularly limited, but is preferably 30 μm or less, more preferably 10 μm or less, still more preferably 5 μm or less.

In the resin sheet according to the embodiment of the present invention, the overall temperature of the resin peeled off from the third cooling drum 14 is preferably in the range of 0 ° C to +15 ° C with respect to the glass transition temperature (Tg) of the polycarbonate. The reason for this is that when the overall temperature of the resin peeled off from the third cooling drum 14 is lower than the glass transition temperature (Tg) of the polycarbonate, the shape of the third cooling drum is transferred by the resin sheet, and the warpage is increased. On the other hand, if the overall temperature of the resin peeled off from the third cooling drum 14 is excessively higher than the glass transition temperature (Tg) of the resin layer in contact with the third cooling drum, the resin sheet cannot obtain preferable surface characteristics. Further, the overall temperature of the resin was measured regardless of the surface of the resin sheet, and the overall temperature of the resin sheet in which the polycarbonate resin and the methacrylic resin were laminated was measured.

In the resin sheet according to the embodiment of the present invention, the linear expansion ratio (SR) is in the range of -10% to +5%, and the glass transition temperature (Tg) of the resin layer containing the methacrylic resin is 120 to 160 °C. Preferably. The reason is as follows.

The resin sheet peeled off from the third cooling drum 14 is sandwiched by the third cooling drum 14 and the winding drum 15 while being sandwiched between the winding drums 15, so that the resin sheet is almost flat. The temperature of the resin sheet after peeling from the third cooling drum 14 is in the range of 0 ° C to +15 ° C with respect to the glass transition temperature (Tg) of the polycarbonate, but the temperature of the resin sheet in the vicinity of the winding drum 15 is cooled to the chamber. It is warm, so it is almost normal temperature.

Further, for example, the temperature of the resin sheet peeled off from the third cooling drum 14 is 150 ° C, and the temperature of the resin sheet in the vicinity of the winding drum is 25 °C. The difference between the coefficient of linear expansion (S1) of the layer containing polycarbonate and the coefficient of linear expansion (S2) of the layer containing the methacrylic resin, specifically, the case where (S1-S2)/S1 is other than zero The one with a larger coefficient of linear expansion shrinks and warps.

Further, for example, the glass transition temperature (Tg) of the layer containing the methacrylic resin is 120 ° C, and the glass transition temperature (Tg) of the layer containing the polycarbonate is 150 °C. In this case, since the temperature of the resin sheet peeled off from the third cooling drum 14 is 150 ° C, the layer containing polycarbonate is cooled from the glass transition temperature (Tg) at 150 ° C to normal temperature. Therefore, the layer containing polycarbonate shrinks almost along the coefficient of linear expansion.

On the other hand, the layer containing the methacrylic resin was cooled from a region (150 ° C) higher than the glass transition temperature to a temperature of about 120 ° C of the glass transition temperature (Tg). Therefore, even if there is no difference between the coefficient of linear expansion (S1) of the layer containing polycarbonate and the coefficient of linear expansion (S2) of the resin constituting the layer containing the methacrylic resin, the layer containing the methacrylic resin, A large shrinkage exceeding the coefficient of linear expansion also occurs.

Here, a general resin is an elastomer at a glass transition temperature or lower, but a viscoelastic body having a function of viscosity and elasticity at a glass transition temperature or higher.

When the stress is applied to the elastic body, strain is generated. However, if it is unloaded, the strain is canceled. On the other hand, if the glass is transferred to the glass transition temperature while stress is applied to the viscoelastic body, the residual strain is obtained. The temperature of the resin sheet peeled off from the third cooling drum 14 is, for example, 150 ° C. When the layer containing the methacrylic resin and the layer containing the polycarbonate are the glass transition temperature, the polycarbonate sheet is an elastomer after the resin sheet is peeled off from the third cooling drum 14, and the methyl group is contained. The layer of acrylic resin is a viscoelastic body. That is, after the resin sheet is peeled off from the third cooling drum 14, only the layer containing the methacrylic resin of the viscoelastic body undergoes shrinkage strain. In other words, the polycarbonate layer of the elastomer is reversible for stress, so even if there is a stress load. Unloading will not happen. In contrast, the layer of viscous elastomer containing methacrylic resin is loaded by stress. Unloading produces residual strain.

From the above, it can be seen that there is a difference between the coefficient of linear expansion (S1) of the layer containing polycarbonate and the coefficient of linear expansion (S2) of the layer containing the methacrylic resin, in other words, the absolute value of the linear expansion ratio (SR) is In the case of a large amount, warpage occurs due to a difference in shrinkage in the elastic body, so warpage occurs at the time when the resin sheet is released from the winding drum 15. Further, in the following, in order to simplify the description, there is a case where the expression "the difference in linear expansion" is expressed. In the case of describing the simple size, "poor" can be fully expressed, but in the case of expressing a quantitative amount of warpage, it is necessary to discuss the linear expansion ratio (SR).

Further, the glass transition temperature (Tg) of the layer containing the methacrylic resin is lower than the glass transition temperature (Tg) of the layer containing the polycarbonate, and the temperature of the resin sheet peeled off from the third cooling drum 14 contains methacrylic acid. In the case where the glass transition temperature (Tg) of the layer of the resin is between the transition temperature (Tg) of the layer containing the polycarbonate, the layer containing the methacrylic resin due to the difference in shrinkage between the elastomer and the viscoelastic body Residual strain. The residual strain is released due to exposure to high temperature and high temperature and high humidity conditions. The tendency to warp when strained. Here, the temperature of the resin sheet after peeling from the third cooling drum 14 is from 0 ° C to + 15 ° C with respect to the glass transition temperature (Tg) of the polycarbonate. Therefore, the polycarbonate is also in a state of a viscoelastic body. Here, the temperature of the resin sheet is cooled to normal temperature before the winding of the drum 15, but the layer containing the methacrylic resin and the layer containing the polycarbonate are simultaneously cooled to room temperature. Therefore, the temperature of the resin sheet after peeling from the third cooling drum 14 to the winding drum 15 includes the glass transition temperature (Tg) of the polycarbonate and the glass transition temperature (Tg) of the layer containing the methacrylic resin. That is, the strain remains in the layer containing the methacrylic resin during the temperature at which the temperature of the resin sheet is cooled from the glass transition temperature (Tg) of the polycarbonate to the glass transition temperature (Tg) of the layer containing the methacrylic resin.

On the other hand, in principle, if the temperature of the resin sheet peeled off from the third cooling drum 14 is less than 150 ° C, the warpage and residual stress due to the linear expansion ratio (SR) tend to decrease, so warpage is caused. Become smaller. However, as described above, the resin sheet is warped due to the shape of the third cooling drum 14 being transferred, which is not preferable.

From this, it is understood that, in order to achieve the object of the present application, the temperature of the resin peeled off from the third cooling drum 14 is in the range of 0 ° C to +15 ° C with respect to the glass transition temperature (Tg) of the polycarbonate, and the linear expansion ratio ( SR) is in the range of -10% to +5%, and the glass transition temperature (Tg) of the layer containing the methacrylic resin is 120 to 160 ° C, whereby a good resin sheet having a small warpage can be obtained.

Example

The invention is illustrated in more detail below by way of examples. However, the invention is not limited to the embodiments.

The physical properties of the resin sheet were measured by the following methods.

[Glass transfer temperature (Tg)]

The obtained resin plate was dried at 80 ° C for 24 hours under reduced pressure (1 kPa), and then 10 mg of the test piece was cut out and sealed with an aluminum pan using a differential scanning calorimeter ("DSC-50") , Rigaku Co., Ltd.), nitrogen substitution for 30 minutes or more. Thereafter, the temperature was raised from 25 ° C to 200 ° C at a rate of 20 ° C / min in a nitrogen stream of 10 ml / minute, held for 10 minutes, and further cooled to 25 ° C (first scan). Subsequently, the temperature was raised to 200 ° C at a rate of 10 ° C /min (second scan), and the glass transition temperature (Tg) was calculated by the midpoint method.

[Linear expansion coefficient]

The coefficient of linear expansion is defined as the rate of change in length per unit temperature change. The coefficient of linear expansion was measured in accordance with JIS K7197 using a thermomechanical analyzer ("TMA4000" manufactured by Bruker AXS Co., Ltd.). In other words, in order to form a smooth end surface of the sheet-like resin sheet which is press-molded with each measurement resin, it is processed into a prism shape having a length of 5 mm × 5 mm and a height of 10 mm using a diamond saw, and each of the processed portions is processed. The sample was placed on a quartz plate in such a manner that a face of 5 mm × 5 mm was in contact with the quartz plate, and a cylindrical rod was placed thereon, and a compression load of 5 g was applied for fixing. Then, in an atmosphere, the temperature was raised from 25 ° C (room temperature) at a temperature increase rate of 3 ° C / min to -10 ° C of the glass transition temperature (Tg) of each sample, and then cooled to 25 ° C (room temperature) (first time) scanning). Subsequently, the temperature was raised from 25 ° C (room temperature) at a temperature increase rate of 3 ° C /min to +20 ° C (second scan) of the glass transition temperature (Tg) of each sample. The expansion ratio of each temperature at the time of the second scanning was measured, and the average linear expansion coefficient in the range of 30 ° C to 80 ° C was obtained.

[warpage amount]

The resin sheets of the examples and the comparative examples were cut into a rectangular shape so that the short side in the direction parallel to the extrusion flow direction and the long side in the direction perpendicular to the extrusion flow direction were cut into rectangles, and the short side was 65 mm. A test piece with a long side of 110 mm. The prepared test piece was placed on the platform so that the layer containing the methacrylic resin was upward, and allowed to stand in an environment of a temperature of 23 ° C and a relative humidity of 50% for 24 hours. Thereafter, the maximum value of the gap between the test piece and the stage was measured using a feeler gauge, and this value was used as the initial warpage amount. Next, in an environmental tester set to a temperature of 85 ° C and a relative humidity of 85%, the test piece was placed on a glass platform so that the layer containing the methacrylic resin was upward, and after being left in this state for 72 hours, Leave at 25 ° C for 4 hours. Thereafter, the measurement was carried out in the same manner as described above, and this value was taken as the amount of warpage after high temperature and high humidity. The test piece was placed on the platform so that the layer containing the methacrylic resin was upward, the sign of the warp that protruded downward was positive, and the sign of the warp that protruded upward was negative. The amount of warpage is ±0.5 mm or less.

[Surface properties]

The both surfaces of the resin sheet were visually observed in a room equipped with a fluorescent lamp, and the surface characteristics were evaluated by the following criteria.

○: No chattering was observed on the surface of the resin sheet.

△: Trembling was observed on the surface of the resin plate, but it was not obvious.

×: The chattering on the surface of the resin plate was remarkable.

[Resin temperature]

The entire temperature of the resin sheet 16 was measured by an infrared radiation thermometer at a position separated from the third cooling drum 14. The temperature measured in this manner is referred to as the resin temperature (TT).

[methacrylic resin A]

"Parapet (registered trademark) HR" (temperature: 230 ° C, MFR = 2.4 g/10 min under a load of 3.8 kg) manufactured by KURARAY Co., Ltd. was prepared as methacrylic resin A.

[methacrylic resin B]

A copolymer obtained by radical polymerization of methyl methacrylate with 8-tricyclo[5.2.1.0 ^2,6 ]decyl methacrylate was prepared as methacrylic resin B.

Further, 8-octyl [5.2.1.0 ^2,6 ] decyl methacrylate accounts for "the total amount of methyl methacrylate and 8-tricyclo [5.2.1.0 ^2,6 ] decyl methacrylate]. The placement ratio (mass percentage) is called the TC ratio.

[methacrylic resin C]

Acrylic three-layer structure rubber particles having an average particle diameter of 0.23 μm were prepared, and contained a hard layer of 35 mass% from the center side (first layer: 94 parts by mass of the MMA unit, 6 parts by mass of the methyl acrylate unit, and methacrylic acid) 0.2 parts by mass of allyl ester unit), 45% by mass of soft layer (second layer, rubber layer: 82.2 parts by mass of butyl acrylate unit, 17.8 parts by mass of styrene unit, 2 parts by mass of allyl methacrylate unit) and 20 Mass% hard layer (third layer: 94 parts by mass of MMA unit, 6 parts by mass of methyl acrylate unit, 0.2 parts by mass of n-octyl thiol unit).

A resin composition in which "91.5 mass% of methacrylic resin B having a TC ratio of 35 mass%" and "8.5 mass% of acrylic three-layered rubber particles having an average particle diameter of 0.23 μm" were prepared as a Based acrylic resin C.

[Resin composition (1)]

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

<methacrylic resin>

As the methacrylic resin, "Parapet (registered trademark) HR" (same as methacrylic resin) manufactured by KURARAY Co., Ltd. was prepared as a methacrylic resin.

<SMA resin>

The SMA resin can be obtained by the following method.

For example, an SMA resin of a styrene-maleic anhydride-MMA copolymer can be obtained by the method described in WO2010/013557.

The mass composition ratio and weight average molecular weight (Mw) of the SMA resin used are shown in Table 1.

<mass composition ratio>

The copolymerization composition of the SMA resin was determined by the 13C-NMR method in the following order.

The 13 C-NMR spectrum system was a nuclear magnetic resonance apparatus (GX-270, manufactured by JEOL Ltd.). 1.5 g of the SMA resin was dissolved in 1.5 ml of deuterated chloroform to adjust the sample solution, and the measurement was carried out under the conditions of 4000 to 5000 times in a room temperature environment. The following values were obtained from the measurement results.

‧ [Integral intensity of carbon peak (near 127, 134, 143 ppm) of benzene ring (carbon number 6) in styrene unit]/6

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

‧[Integral intensity of carbon peak (near 175ppm) of carbonyl moiety (carbon number 1) in MMA unit]/1

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

<weight average molecular weight (Mw)>

The Mw of the SMA resin was determined by the GPC method in the following order.

Two TSKgel SuperMultipore HZM-M manufactured by Tosoh Co., Ltd. and SuperHZ4000 were connected in series as a column using tetrahydrofuran as an eluent. As the GPC device, HLC-8320 (product name) manufactured by Tosoh Co., Ltd. equipped with a differential refractive index detector (RI detector) was used. 4 mg of the SMA resin was dissolved in 5 ml of tetrahydrofuran to adjust the sample solution. The temperature of the column oven was set to 40 ° C, the eluent flow rate was 0.35 ml/min, 20 μl of the sample solution was injected, and the chromatogram was measured. A standard polystyrene having a molecular weight of 400 to 5,000,000 was measured by GPC at 10 points to prepare a calibration curve showing the relationship between the retention time and the molecular weight. The Mw is determined based on the calibration curve.

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

[polycarbonate]

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

[Example 1] (Manufacturing method of resin board)

A 150 mmφ uniaxial extruder (manufactured by Toshiba Machine Co., Ltd.) was used to melt methacrylic resin B (glass transition temperature: 120 degrees, linear expansion coefficient: 7.30 × 10 ^-5 /K) having a TC ratio of 20% by mass. A 150 mmφ single-axis extruder (manufactured by Toshiba Machine Co., Ltd.) melts polycarbonate and passes through a multi-split mold to laminate both layers. The resin (the resin sheet 16 and the thermoplastic resin laminate in a molten state) is sandwiched between the first cooling drum 12 and the second cooling drum 13 as shown in Fig. 1 and wound around the second cooling drum 13, The third cooling drum 14 is wound around the cooling drum 14 to be cooled, and the resin sheet 16 is wound by the winding drum 15 . The resin temperature (TT) was adjusted to 150 ° C by controlling the temperatures of the second cooling drum 13 and the third cooling drum 14 . The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Embodiment 2]

The methacrylic resin B and the polycarbonate having a TC ratio of 35 mass% were melted in the same manner as described above to produce a resin sheet. The resin temperature (TT) was adjusted to 150 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Example 3]

The methacrylic resin B having a TC ratio of 45 mass% and a polycarbonate were melted in the same manner as described above. The resin temperature (TT) was adjusted to 155 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Example 4]

The methacrylic resin B having a TC ratio of 60% by mass and a polycarbonate were melted in the same manner as described above. The resin temperature (TT) was adjusted to 155 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Example 5]

The resin composition (1) having a SMA ratio of 20% by mass was melted and produced in the same manner as described above. The resin temperature (TT) was adjusted to 150 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Embodiment 6]

The resin composition (1) having a SMA ratio of 50% by mass was melted and produced in the same manner as described above. The resin temperature (TT) was adjusted to 150 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Embodiment 7]

The resin composition (1) having a SMA ratio of 70% by mass was melted and produced in the same manner as described above. Same as above The resin temperature (TT) was adjusted to 155 °C. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Embodiment 8]

The resin composition (1) having a SMA ratio of 100% by mass was melted and produced in the same manner as described above. The resin temperature (TT) was adjusted to 155 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Embodiment 9]

The resin composition (1) having a SMA ratio of 70% by mass was melted and produced in the same manner as described above. The resin temperature (TT) was adjusted to 165 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Comparative Example 1]

The methacrylic resin A and the polycarbonate were melted in the same manner as described above. The resin temperature (TT) was adjusted to 150 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Comparative Example 2]

The resin composition (1) having a SMA ratio of 70% by mass was melted and produced in the same manner as described above. The resin temperature (TT) was adjusted to 145 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Comparative Example 3]

The resin composition (1) having a SMA ratio of 70% by mass was melted and produced in the same manner as described above. Same as above The resin temperature (TT) was adjusted to 170 °C. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

[Comparative Example 4]

A resin plate was produced in the same manner as in Example 2 except that the methacrylic resin B having a TC ratio of 35 mass% was changed to the methacrylic resin C. The resin temperature (TT) was adjusted to 150 ° C in the same manner as above. The manufacturing conditions and the evaluation results of the obtained resin sheets are shown in Table 2.

In Table 2, the resin temperature (TT), the glass transition temperature (Tg), the linear expansion coefficient of the resin sheet, the linear expansion ratio (SR), and the amount of warpage after the initial and high-temperature and high-humidity are shown in the examples and the comparative examples, respectively. And the measurement results of surface characteristics.

In Examples 1 to 4, a layer containing a methacrylic resin B containing a TC ratio of 20 to 60% by mass and a polycarbonate-containing layer were produced. The resin sheet of the ester layer was tested. As shown in Table 2, in the case where the layer containing the methacrylic resin B having a TC ratio of 45% was used in Example 3, the glass transition temperature (Tg), the coefficient of linear expansion coefficient (SR), and the amount of warpage were considered. For the best results.

In Examples 5 to 9, a resin sheet in which a layer containing a resin composition (1) having a SMA ratio of 20 to 100% by mass and a layer containing a polycarbonate were laminated was tested. As shown in Table 2, in the examples 7 and 9, when the layer containing the resin composition (1) having a SMA ratio of 70% by mass was used, the absolute value of the amount of warpage was small, which was the best result.

On the other hand, in Comparative Example 1, the glass transition temperature (Tg) was low, and the warpage after high temperature and high humidity was large. In Comparative Example 2, when the resin temperature (TT) was lowered, the resin sheet having a large warpage amount was obtained. In Comparative Example 3, when the resin temperature (TT) was increased, the resin sheet having poor surface properties was obtained. In Comparative Example 4, the requirements of the coefficient of linear expansion did not satisfy the present application, so the warpage after initial warpage and high temperature and high humidity was large.

Industrial availability

The resin sheet of the present invention can be used for a protective casing such as a liquid crystal display protection panel or a touch panel, and is suitable for use in a vehicle display device, a mobile phone, a smart phone, a notebook computer, a television, and the like.

The present invention is not limited to the embodiments described above, and may be modified as appropriate without departing from the scope of the invention.

The present application claims priority on the basis of Japanese Patent Application No. 2014-190029, filed on Sep. 18, 2014, the entire content of which is incorporated herein.

11‧‧‧T-model

12‧‧‧1st cooling drum

13‧‧‧2nd cooling roller

14‧‧‧3rd cooling roller

15‧‧‧ winding drum

16‧‧‧resin board

Claims (7)

A method for producing an extruded resin sheet, which is a method for producing an extruded resin sheet in which a layer containing a methacrylic resin is laminated on at least one side of a layer containing a polycarbonate, comprising the steps of: The difference between the coefficient of linear expansion (S1) of the layer of polycarbonate and the coefficient of linear expansion (S2) of the layer containing the methacrylic resin (S2-S1), and the coefficient of linear expansion of the layer containing the polycarbonate ( The ratio of S1) ((S2-S1)/S1) is -10% to +5%; the glass transition temperature of the layer containing the methacrylic resin is 120 to 160 ° C; in the molten state, it will be contained therein a thermoplastic resin laminate in which at least one layer of the polycarbonate layer is laminated with the layer containing the methacrylic resin is extruded from a T-die; the thermoplastic resin laminate is sandwiched between the first cooling drum and the second cooling drum After the thermoplastic resin laminate is wound around the second cooling drum, it is wound around the third cooling drum to be cooled, and the thermoplastic resin laminate is wound by the winding drum; The position of the thermoplastic resin laminate is peeled off so that the overall temperature of the resin is relative to The glass transition temperature of the polycarbonate-containing layer is in the range of 0 ° C to + 15 ° C. An extruded resin sheet comprising the extruded resin sheet obtained by the production method of claim 1, wherein the layer containing the methacrylic resin contains 40 to 80% by mass of a structure derived from methyl methacrylate a unit containing 20 to 60% by mass of a structural unit derived from a methacrylate represented by the following formula (I); (wherein Cy represents an alicyclic hydrocarbon group). The extruded resin sheet of claim 2, wherein Cy in the formula (I) is a polycyclic aliphatic hydrocarbon group. An extruded resin sheet comprising the extruded resin sheet obtained by the production method of claim 1, wherein the layer containing the methacrylic resin contains less than 80% by mass of methacrylic resin, and 20% by mass The above comprises at least a structural unit derived from an aromatic vinyl compound represented by the following formula (II) and a copolymer derived from a structural unit of an acid anhydride represented by the following formula (III); (wherein R ¹ and R ² each independently represent a hydrogen atom or an alkyl group); (wherein R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group). The extruded resin sheet according to claim 4, wherein the copolymer contains 50 to 84% by mass of a structural unit derived from the aromatic vinyl compound, and contains 15 to 49% by mass of a structural unit derived from the acid anhydride, and contains 1 to 25 Mass % methacrylate monomer. The extruded resin sheet of claim 5, wherein the methacrylate monomer is methyl methacrylate. The extruded resin sheet according to any one of claims 2 to 6, wherein at least one of the surfaces is further provided with a scratch-resistant layer.