WO2009104399A1

WO2009104399A1 - Resin sheet for forming and formed object

Info

Publication number: WO2009104399A1
Application number: PCT/JP2009/000695
Authority: WO
Inventors: 三荒直也; 西川良樹
Original assignee: 三菱樹脂株式会社
Priority date: 2008-02-20
Filing date: 2009-02-19
Publication date: 2009-08-27
Also published as: CN103465579A; KR101484875B1; TWI438087B; CN104325766A; KR20130119008A; KR20140104051A; JP4971218B2; KR20140103186A; TW200940334A; KR20100116670A; KR101620645B1; CN101952119A; JP2009196153A

Abstract

A resin sheet for forming is provided which is made of a polycarbonate resin as the main material. Even when thermoformed especially by deep drawing, the resin sheet neither cracks, foams, nor causes whitening. The resin sheet for forming is a layered sheet comprising: a base layer including, as the main component, a polycarbonate resin composition (A) comprising a polymer alloy constituted of an aromatic polycarbonate (A1) and another resin (A2); and a coating layer including an acrylic resin (B) as the main component and superposed on one side of the base layer. The difference in glass transition temperature between the polycarbonate resin composition (A) and the acrylic resin (B) is within 30°C in terms of absolute value.

Description

Resin sheet for molding and molded body

The present invention is a resin sheet using a polycarbonate-based resin as a main material, and is a molding resin sheet suitable for thermoforming such as vacuum molding and pressure forming, and a molded body formed by molding this molding resin sheet About.

Polycarbonate resins are widely used in various fields because they are not only excellent in transparency, but also excellent in processability and impact resistance compared to glass, and are free from the risk of toxic gases compared to other plastic materials. It is also used as a material for thermoforming such as vacuum forming and pressure forming.

However, since the polycarbonate resin generally has a low surface hardness, it has a problem that the surface of a molded product made of the polycarbonate resin is easily damaged. Therefore, conventionally, a proposal has been made to form a protective layer made of an acrylic resin on the surface of the polycarbonate resin layer so that the product surface is not damaged.

For example, Patent Document 1 proposes a laminate having a total thickness of 0.5 to 1.2 mm by co-extrusion of an acrylic resin layer having a thickness of 50 to 120 μm on one surface of a polycarbonate resin layer. Has been.

Moreover, in patent document 2, as a scratch-resistant acrylic film suitable for a display window protection plate of a portable information terminal, a hard coat treatment is applied to an acrylic film including an acrylic resin layer in which rubber particles are dispersed in a methacrylic resin. A scratch-resistant acrylic film is disclosed that is applied to impart scratch resistance.

JP 2006-103169 A Japanese Patent Laid-Open No. 2004-143365

As described above, when a protective layer made of an acrylic resin is formed on the surface of the polycarbonate resin layer, the acrylic resin is generally harder to stretch than the polycarbonate resin, and therefore, when thermoformed, especially deep drawing When this occurs, peeling may occur at the interface between the polycarbonate resin layer and the acrylic resin layer, and the surface may be whitened or cracks may occur. In addition, foaming may occur if it is not sufficiently dried before thermoforming.

Therefore, the present invention provides a molding resin sheet having such a laminated structure, a new molding resin sheet that does not cause whitening, cracking, or foaming even when thermoformed, particularly when deep drawing. And a molded body formed by molding the same.

The present invention provides an acrylic resin (B) on one side of a base material layer mainly composed of a polycarbonate resin composition (A) composed of a polymer alloy of an aromatic polycarbonate (A1) and another resin (A2). A laminated sheet having a coating layer as a main component, wherein the absolute value of the difference in glass transition temperature between the polycarbonate resin composition (A) and the acrylic resin (B) is within 30 ° C. We propose a characteristic molding resin sheet.

Since the molding resin sheet of the present invention includes the coating layer mainly composed of the acrylic resin (B), the coating layer surface of the molding resin sheet and the product surface formed by molding the molding resin sheet It has the feature that it is hard to get scratches.
Moreover, the difference (absolute value) in glass transition temperature between the polycarbonate resin composition (A), which is the main component of the base material layer, and the acrylic resin (B), which is the main component of the coating layer, is set within 30 ° C. As a result, it was possible to prevent whitening, cracks, and foaming even when thermoforming, particularly when deep drawing.
Therefore, if it heat-molds using the resin sheet for shaping | molding of this invention, not only the molded object excellent in the designability but the in-mold molded object etc. excellent in the designability etc. can be provided, for example.

In addition, although there may exist various methods as a method of making the difference (absolute value) of the glass transition temperature of polycarbonate-type resin composition (A) and acrylic resin (B) within 30 degreeC, this method From the standpoint of maintaining the transparency of the sheet, the invention lowers the glass transition temperature by polymer-alloying the aromatic polycarbonate (A1) and the other resin (A2), so that the difference between the two glass transition temperatures (absolute The method of setting the value) within 30 ° C. is adopted.

BEST MODE FOR CARRYING OUT THE INVENTION

Next, an example of an embodiment of the present invention will be described, but the present invention is not limited to the following embodiment.

The resin sheet for molding according to the present embodiment (hereinafter referred to as “the resin sheet for molding”) is a polycarbonate resin composition (A) made of a polymer alloy of an aromatic polycarbonate (A1) and another resin (A2). A laminated sheet comprising a coating layer mainly composed of an acrylic resin (B) on one surface of a base material layer comprising a main component, the polycarbonate resin composition (A) and the acrylic resin (B) A resin sheet for molding characterized in that the absolute value of the difference in glass transition temperature (Tg) is within 30 ° C., that is, 0 ° C.-30 ° C., preferably 0-20 ° C., particularly preferably 0-10 ° C. is there.

<Base material layer>
The base material layer of the resin sheet for molding can be formed with a polycarbonate resin composition (A) composed of a polymer alloy of an aromatic polycarbonate (A1) and another resin (A2) as a main component.

[Aromatic polycarbonate (A1)]
The aromatic polycarbonate used for the resin sheet for molding is not particularly limited as long as it is a polycarbonate having an aromatic ring. For example, an aromatic dihydroxy compound, or an aromatic dihydroxy compound and a small amount of a polyhydroxy compound can be obtained by an interfacial polymerization method with phosgene, or heat obtained by a transesterification reaction between the aromatic dihydroxy compound and a carbonic acid diester. Examples thereof include a plastic polycarbonate polymer. More specifically, for example, a carbonate polymer containing bisphenol A as a main raw material can be mentioned.

The molecular weight of the aromatic polycarbonate is not particularly limited as long as a sheet can be produced by ordinary extrusion molding, but the viscosity average molecular weight [Mv] converted from the solution viscosity is 15,000 to 40,000, particularly 20, It is preferably from 2,000 to 35,000, especially from 22,000 to 30,000.
Two or more types of aromatic polycarbonates having different viscosity average molecular weights may be mixed.

Here, the viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer, Schnell's viscosity formula, That is, it means a value calculated from η = 1.23 × 10 −4 M0.83. The intrinsic viscosity [η] is a value calculated by measuring the specific viscosity [ηsp] at each solution concentration [C] (g / dl).

The terminal hydroxyl group concentration of the aromatic polycarbonate is preferably 1000 ppm or less, particularly 800 ppm or less, and particularly preferably 600 ppm or less. The lower limit is preferably 10 ppm or more, particularly 30 ppm or more, and particularly preferably 40 ppm or more.

Here, the terminal hydroxyl group concentration represents the mass of the terminal hydroxyl group with respect to the mass of the aromatic polycarbonate in ppm units. For example, colorimetric determination (Macromol. Chem. 88215 (1965) by the titanium tetrachloride / acetic acid method. )).

[Other resin (A2)]
The other resin (A2) can be polymer-alloyed by melt blending (; mixing and heat-melting) with the aromatic polycarbonate (A1), and the glass transition temperature (Tg) of the polymer alloy Any material can be used as long as it is lower than the glass transition temperature (Tg) of the aromatic polycarbonate (A1).
Generally, the glass transition temperature (Tg) of an aromatic polycarbonate is around 150 ° C., and is nearly 50 ° C. higher than the glass transition temperature (Tg) of an acrylic resin. In order to make the difference (absolute value) of the glass transition temperature (Tg) of the resin (B) within 30 ° C., the aromatic alloy (A1) and the other resin (A2) are polymerized to form the polymer alloy. It is important that the glass transition temperature (Tg) can be lowered.

From this point of view, the other resin (A2) is preferably an aromatic polyester. Next, the aromatic polyester will be described.

(Aromatic polyester)
Examples of the aromatic polyester used as the other resin (A2) include a resin obtained by condensation polymerization of an “aromatic dicarboxylic acid component” and a “diol component”.

Here, representative examples of the “aromatic dicarboxylic acid component” include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the like. A part of terephthalic acid may be substituted with “another dicarboxylic acid component”.
"Other dicarboxylic acid components" include oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, neopentylic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyl ether dicarboxylic acid, p-oxybenzoic acid, etc. It is done. These may be one kind or a mixture of two or more kinds, and the amount of other dicarboxylic acids to be substituted can be appropriately selected.

Typical examples of the “diol component” include ethylene glycol, diethylene glycol, triethylene glycol, cyclohexanedimethanol and the like. A part of ethylene glycol may be substituted with “another diol component”.
“Other diol components” include propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, neopentyl glycol, polyalkylene glycol, 1,4-cyclohexanedimethanol, glycerin, pentaerythritol, trimethylol, A methoxy polyalkylene glycol etc. are mentioned. These may be one kind or a mixture of two or more kinds, and the amount of other diols to be substituted can be appropriately selected.

Specific examples of the “aromatic polyester” include polyethylene terephthalate obtained by condensation polymerization of terephthalic acid and ethylene glycol, polybutylene terephthalate obtained by condensation polymerization of terephthalic acid or dimethyl terephthalate and 1,4-butanediol, and the like. it can. Moreover, “copolyester” containing a dicarboxylic acid component other than terephthalic acid and / or a diol component other than ethylene glycol can also be mentioned as a preferred aromatic polyester.

Among them, as a preferable example, a part of ethylene glycol in polyethylene terephthalate, preferably a copolyester having a structure obtained by substituting 55 to 75 mol% with cyclohexanedimethanol, or a part of terephthalic acid in polybutylene terephthalate, preferably May include a copolyester having a structure in which 10-30 mol% is substituted with isophthalic acid, or a mixture of these copolyesters.

Among the aromatic polyesters described above, a polymer alloy is formed by melt blending with the aromatic polycarbonate (A1), and the glass transition temperature (Tg) of the polymer alloy is sufficiently higher than that of the aromatic polycarbonate (A1). It is preferable to select one that can be reduced.

From this point of view, a copolyester having a structure in which 50 to 75 mol% of ethylene glycol, which is a diol component of polyethylene terephthalate (PET), is substituted with 1,4-cyclohexanedimethanol (1.4-CHDM). (So-called “PCTG”), or a copolyester having a structure obtained by substituting a part of terephthalic acid of polybutylene terephthalate (PBT), preferably 10 to 30 mol% with isophthalic acid, or a mixture thereof. This is the most preferred example. These copolyesters are known to be completely compatible and polymerized by melt blending with an aromatic polycarbonate, and can effectively lower the glass transition temperature.

Whether the polymer blend (mixed resin composition) is a polymer alloy, in other words, whether it is completely compatible or not is determined by, for example, a glass transition temperature measured at a heating rate of 10 ° C./min by differential scanning calorimetry. Can be determined by whether or not is single. Here, the glass transition temperature of the mixed resin composition is single when the glass transition temperature of the mixed resin composition is measured using a differential scanning calorimeter at a heating rate of 10 ° C./min according to JISK7121. This means that only one peak indicating the glass transition temperature appears.
Further, when the mixed resin composition was measured by dynamic viscoelasticity measurement (dynamic viscoelasticity measurement of JISK-7198A method) at a strain of 0.1% and a frequency of 10 Hz, the maximum value of loss tangent (tan δ) was obtained. It can also be determined whether or not one exists.
If the polymer blend (mixed resin composition) is completely compatible (polymer alloying), the blended components are compatible with each other on the nanometer order (molecular level).

In addition, as means for polymer alloying, it is possible to use a compatibilizer, secondary block polymerization or graft polymerization, or dispersion of one polymer in a cluster.

[Mixing ratio]
The mixing ratio of the aromatic polycarbonate (A1) and the aromatic polyester (A2) is the difference in the glass transition temperature (Tg) between the polycarbonate resin composition (A) and the acrylic resin (B) obtained by mixing ( The ratio is not limited as long as the absolute value is within 30 ° C. However, from the viewpoint of maintaining transparency, the mass ratio is preferably A1: A2 = 20: 80 to 75:25, particularly A1: A2 = 30: 70 to 60:40, and particularly preferably A1: A2 = 45: 55 to 55:45.

<Coating layer>
The coating layer of the thermoforming resin sheet can be formed from a resin composition containing an acrylic resin (B) as a main component.

[Acrylic resin (B)]
The acrylic resin used for the thermoforming resin sheet is not particularly limited as long as it is a resin having an acrylic group. For example, a copolymer of methyl methacrylate and methyl acrylate or ethyl acrylate can be given. Among them, a methyl methacrylic resin (PMMA: also referred to as polymethylmeth (a) acrylate) whose main component is polymerized from methyl methacrylic acid is preferable.

The copolymer composition of the acrylic resin is preferably selected as appropriate according to production conditions, for example, coextrusion conditions. For example, in the case of a copolymer of methyl methacrylate and methyl acrylate or ethyl acrylate, a molar ratio of methyl methacrylate: methyl or ethyl acrylate = 80: 20 to 1:99 is preferable.
Moreover, you may contain a crosslinking component in the range in which extrusion molding is possible.

The molecular weight of the acrylic resin is generally 30,000 to 300,000 in terms of weight average molecular weight, but is not limited to this range.

Commercial products can also be used as the acrylic resin. For example, Sumitomo Chemical Co., Ltd .: SUMPEX series, Mitsubishi Rayon Co., Ltd .: Acrypet series, Kuraray Co., Ltd .: Parapet series, Asahi Kasei: Delpet, etc. . However, it is not limited to these.

The acrylic resin (B) may contain an ultraviolet absorber for the purpose of maintaining the weather resistance for a long period of time. The content of the ultraviolet absorber is preferably 0.01 to 3.0% by mass of the acrylic resin.
Moreover, in order to prevent thermal deterioration of the acrylic resin during coextrusion molding, an antioxidant, an anti-coloring agent and the like may be contained. At this time, the content of the antioxidant is preferably 0.01 to 3% by mass of the acrylic resin, and the content of the colorant is preferably 0.01 to 3% by mass.
In any of the above cases, it is assumed that a sufficient effect cannot be obtained when the content is less than 0.01% by mass of the acrylic resin. Conversely, even if the content exceeds 5% by mass, no further effect can be expected. In addition, it is not preferable because it may cause bleed-out and cause whitening, or may cause deterioration in adhesion and impact strength.

Further, in order to further increase the surface hardness, transparency may be maintained by dispersing high Tg acrylic or the like in the acrylic resin. In addition, by adding a methyl methacrylate-styrene copolymer resin (MS resin), it is possible to reduce water absorption and suppress foaming.

<Sheet thickness>
The thickness of each layer of the resin sheet for molding and the entire sheet can be appropriately set within a range in which the surface hardness and formability do not cause a problem. However, in general, the thickness of the entire sheet is preferably 0.2 mm to 2.0 mm, and the thickness of the coating layer is preferably 10 μm to 40 μm, particularly preferably 30 μm to 40 μm.

<Manufacturing method>
Although the manufacturing method of the resin sheet for this shaping | molding is not restrict | limited in particular, It is preferable to laminate | stack a base material layer and a coating layer by coextrusion from a viewpoint of productivity.
For example, the polycarbonate resin composition (A) and the acrylic resin (B) are heated and melted in separate extruders, extruded from the slit-shaped discharge ports of the T-die and laminated, and then adhered to the cooling roll. Examples of the production method include solidification.

The aromatic polycarbonate (A1) and the other resin (A2) may be mixed when the polycarbonate resin composition (A) is heated and melted with an extruder, but is mixed and melted (melt blended) in advance. It is preferable to prepare a polymer alloy by adding a compatibilizer or the like as necessary.

Also, it is preferable that the temperature at which the resin is heated and melted by the extruder is 80 to 150 ° C. higher than the glass transition temperature (Tg) of each resin. In general, the temperature condition of the main extruder for extruding the polycarbonate resin composition (A) is usually 230 to 290 ° C., preferably 240 to 280 ° C., and the acrylic resin (B) is pressed. The temperature condition of the sub-extruder to be discharged is usually 220 to 270 ° C., preferably 230 to 260 ° C.

In addition, as a method of co-extrusion of two types of molten resins, a known method such as a feed block method or a multi-manifold method can be employed.
For example, in the case of the feed block method, the molten resin laminated in the feed block is guided to a sheet forming die such as a T die, formed into a sheet shape, and then flowed into a forming roll (polishing roll) whose surface is mirror-finished. A bank is formed, and mirror finishing and cooling may be performed while passing through the forming roll.
In the case of the multi-manifold system, the molten resin laminated in the multi-manifold die may be formed into a sheet shape inside the die, and then surface finishing and cooling may be performed with a forming roll.
In any case, the die temperature is usually set to 230 to 290 ° C., particularly 250 to 280 ° C., and the forming roll temperature is preferably set to 100 to 190 ° C., particularly 110 to 190 ° C.

<Features and applications>
Since the molding resin sheet has a coating layer mainly composed of the acrylic resin (B), the coating layer surface of the molding resin sheet and the product surface formed by molding the molding resin sheet are damaged. It has the feature that is difficult to enter. And the absolute value of the difference of the glass transition temperature of the polycarbonate-type resin composition (A) which is a main component of a base material layer, and the acrylic resin (B) which is a main component of a coating layer was set within 30 degreeC. Thus, even when thermoformed so that the coating layer side becomes the surface of the product, it is possible to prevent whitening, cracks, and even foaming, especially when deep drawing.
Therefore, if thermoforming is performed using the resin sheet for molding, a thermoformed article having excellent design properties, particularly a thermoformed article having excellent design properties obtained by deep drawing can be obtained.
In the present invention, the deep drawing height when molding is 3 mm or more, particularly 5 mm or more is called deep drawing. In the case of the resin sheet for molding, the deep drawing height is 7 mm or more. However, whitening, cracks, and foaming can be prevented.
In addition, since the resin sheet for molding has the above-described features, for example, a printing layer is formed on the substrate layer side of the molding resin sheet and thermoformed, and a molten resin is injected on the printing layer side. By forming the backing layer by molding, an in-mold molded body having excellent design properties can be produced.

<Explanation of terms>
In the present invention, the “main component” includes the meaning of allowing other components to be contained within a range that does not interfere with the function of the main component, unless otherwise specified. At this time, although the content ratio of the main component is not specified, the main component (when two or more components are main component resins, the total amount thereof) is 50% by mass or more, particularly 70% in the composition. It is preferable to occupy at least 90% by mass, especially 90% by mass (including 100%).
In general, “sheet” is a thin product as defined by JIS and generally has a thickness that is small and flat instead of length and width. In general, “film” refers to length and width. A thin flat product having an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (Japanese Industrial Standard JISK6900). However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.
Further, in the present invention, when expressed as “X to Y” (X and Y are arbitrary numbers), “X is preferably greater than X” and “ Is less than Y.

Next, examples of the present invention will be described, but the present invention is not limited to these examples.

<Measuring method of glass transition temperature>
Using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer, measured at a heating rate of 10 ° C./min after holding at −40 ° C. for 1 minute in a nitrogen atmosphere, and the differential of the obtained DSC curve The temperature at which the maximum value was reached was determined as the glass transition temperature.

Example 1
Polycarbonate resin composition (A) and acrylic resin (B) are heated and melted in separate extruders, and two types of resins are melt-extruded simultaneously from the slit-shaped discharge port of the T-die and laminated in two layers of two layers. did.
The main extruder for extruding the polycarbonate resin composition (A) was set to a barrel diameter of 65 mm, a screw L / D = 35, and a cylinder temperature of 270 ° C. The sub-extruder for extruding the acrylic resin (B) was set to a barrel diameter of 32 mm, a screw L / D = 32, and a cylinder temperature of 250 ° C.

The polycarbonate resin composition (A) is composed of an aromatic polycarbonate (bisphenol A type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.), and polycyclohexanedimethylene terephthalate resin. (Low-crystalline copolyester having a structure in which 65 mol% of ethylene glycol in PET is substituted with 1.4-CHDM. Tg 86 ° C.) in a mass ratio of 50:50 and heating. A polycarbonate resin composition prepared by melt kneading and polymerizing was prepared. When the glass transition temperature of this polycarbonate resin composition was measured, the maximum value of the differential of the DSC curve was single (Tg 110 ° C.), and it was confirmed that it was a polymer alloy.
As the acrylic resin (B), an acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd., trade name Acrypet MD, composition: polymethyl methacrylate, Tg 110 ° C.) was used.

A feed block was used to laminate two layers of two types. The temperature inside the die head was 250 ° C., and the resin laminated in the die was guided to three cast rolls having a mirror-finished horizontal arrangement. At this time, the first roll temperature was 110 ° C, the second roll temperature was 140 ° C, and the third roll temperature was 185 ° C.
The rotation speed of the main extruder and the sub-extruder is set so that the discharge amount ratio is main / sub = 470/30, and is co-extruded so that the thickness becomes 0.5 mm. A thickness of 0.5 mm and a coating layer thickness of 30 μm) were obtained.
The evaluation results of the obtained molding resin sheet are shown in Table 1.

(Example 2)
Except having changed the kind of polycarbonate-type resin composition (A), the resin sheet for shaping | molding (The whole sheet | seat thickness 0.5mm, coating layer thickness 40micrometer) was obtained on the same manufacturing conditions as Example 1. FIG.

The polycarbonate-based resin composition (A) used in this example is an aromatic polycarbonate (bisphenol A-type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.) Polycyclohexanedimethylene terephthalate resin (low crystalline copolymer polyester having a structure in which 65 mol% of ethylene glycol of PET is substituted with 1.4-CHDM. Tg 86 ° C.) at a mass ratio of 80:20 A polycarbonate-based resin composition obtained by mixing, melting and kneading while heating to form a polymer alloy was used. When the glass transition temperature of this polycarbonate-based resin composition was measured, the maximum value of the differential of the DSC curve was single (Tg 135 ° C.), and it was confirmed that it was a polymer alloy.
The evaluation results of the obtained molding resin sheet are shown in Table 1.

(Example 3)
Except having changed the kind of polycarbonate-type resin composition (A), the resin sheet for shaping | molding (The whole sheet | seat thickness 0.5mm, coating layer thickness 40micrometer) was obtained on the same manufacturing conditions as Example 1. FIG.

The polycarbonate-based resin composition (A) used in this example is an aromatic polycarbonate (bisphenol A-type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.) Polycyclohexanedimethylene terephthalate resin (low crystalline copolyester having a structure in which 65 mol% of ethylene glycol of PET is substituted with 1.4-CHDM. Tg 86 ° C.) and copolyester (terephthalic acid in polybutylene terephthalate) Polycarbonate polyester having a structure in which 30 mol% of the above is substituted with isophthalic acid (Tg 30 ° C.) in a mass ratio of 70:20:10 and melt-kneaded while heating to make a polymer alloy. A resin composition was used. When the glass transition temperature of this polycarbonate resin composition was measured, the maximum value of the differential of the DSC curve was single (Tg 140 ° C.), and it was confirmed to be a polymer alloy.
The evaluation results of the obtained molding resin sheet are shown in Table 1.

Example 4
Except having changed the kind of polycarbonate-type resin composition (A), the resin sheet for shaping | molding (The sheet | seat whole thickness 0.5mm, coating layer thickness 30micrometer) was obtained on the same manufacturing conditions as Example 1. FIG.

The polycarbonate-based resin composition (A) used in this example is an aromatic polycarbonate (bisphenol A-type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.) Polycyclohexanedimethylene terephthalate resin (low crystalline copolymer polyester having a structure in which 65 mol% of ethylene glycol of PET is substituted with 1.4-CHDM. Tg 86 ° C.) at a mass ratio of 35:65 A polycarbonate-based resin composition that was mixed, melt-kneaded while heating and polymerized was used. When the glass transition temperature of this polycarbonate resin composition was measured, the maximum value of the differential of the DSC curve was single (Tg 105 ° C.), and it was confirmed to be a polymer alloy.
The evaluation results of the obtained molding resin sheet are shown in Table 1.

(Example 5)
A molding resin sheet (total sheet thickness 0.5 mm, coating layer thickness 35 μm) was obtained under the same production conditions as in Example 1, except that the type of the polycarbonate resin composition (A) was changed.

The polycarbonate-based resin composition (A) used in this example is an aromatic polycarbonate (bisphenol A-type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.) Polycyclohexanedimethylene terephthalate resin (low crystalline copolymer polyester having a structure in which 65 mol% of ethylene glycol of PET is substituted with 1.4-CHDM. Tg 86 ° C.) at a mass ratio of 25:75 A polycarbonate-based resin composition that was mixed, melt-kneaded while heating and polymerized was used. When the glass transition temperature of this polycarbonate resin composition was measured, the maximum value of the differential of the DSC curve was single (Tg 90 ° C.), and it was confirmed that it was a polymer alloy.
The evaluation results of the obtained molding resin sheet are shown in Table 1.

(Comparative Example 1)
Under the same molding conditions as in Example 1, the acrylic resin (B) was not coextruded to obtain a single layer sheet (total sheet thickness 0.5 mm) of the polycarbonate resin composition (A).
The extruder for extruding the polycarbonate resin composition (A) was set to a barrel diameter of 65 mm, a screw L / D = 35, and a cylinder temperature of 270 ° C.

As the polycarbonate resin composition (A), an aromatic polycarbonate (bisphenol A type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.) was used.
The evaluation results of the obtained molding resin sheet are shown in Table 2.

(Comparative Example 2)
A molding resin sheet (total sheet thickness 0.5 mm, coating layer thickness 35 μm) was obtained under the same production conditions as in Example 1, except that the type of the polycarbonate resin composition (A) was changed.

The polycarbonate-based resin composition (A) used in this comparative example contains an aromatic polycarbonate (bisphenol A type aromatic polycarbonate produced by an interfacial polymerization method, viscosity average molecular weight 28000, terminal hydroxyl group concentration = 150 ppm, Tg 145 ° C.). Using.
The evaluation results of the obtained molding resin sheet are shown in Table 2.

(Comparative Example 3)
A molding resin sheet (overall sheet thickness 0.5 mm, coating layer thickness 35 μm) was obtained under the same production conditions as in Comparative Example 2 except that the molding temperature was changed to 110 ° C.
The evaluation results of the obtained molding resin sheet are shown in Table 2.

<Test and evaluation>
1) Pencil Hardness Based on JIS K5400, the pencil hardness on the surface of the molding resin sheet obtained in Examples and Comparative Examples (the surface of the coating layer when a coating layer is formed) was measured with a 1 kg load.
Then, “H”, which is a level that has no problem in practical use, is used, and “H”, “2H”, etc. higher than this are evaluated as pass (“◯”), and “B” below this is rejected (“×”). ).

2) Formability (deep drawability)
The molding resin sheets obtained in the examples and comparative examples were cut into 100 mm × 200 mm × (thickness) 0.5 mm, and the obtained sample sheets were preheated to 120 to 150 ° C., and the temperature (Table 1 and In Table 2), pressure forming was performed to the deep drawing heights shown in Tables 1 and 2 with high-pressure air of 5 MPa. In addition, the deep drawing height was set using a mold in which the deep drawing height was changed in increments of 1 mm, such as 1 mm, 2 mm... 5 mm.
The surface state (crack, whitening, foaming, unevenness) of the obtained molded body was observed, and when no cracks, whitening, foaming and unevenness were observed, it was evaluated as “no appearance abnormality”, and further 5 mm or more deep What was able to shape | mold the shaping | molding body of drawing height in the state without appearance abnormality was evaluated comprehensively as a pass ("(circle)").

(Discussion)
As a result, it was confirmed that the hardness of the molding resin sheet surface (coating layer surface) can be sufficiently increased by forming the coating layer mainly composed of the acrylic resin (B). Therefore, not only the molding resin sheet but also the product surface obtained by molding the sheet can be made difficult to be damaged.
The absolute value of the difference in glass transition temperature between the polycarbonate resin composition (A), which is the main component of the base material layer, and the acrylic resin (B), which is the main component of the coating layer, is set within 30 ° C. Thus, it has been found that a molded product can be obtained without causing appearance defects such as cracks, whitening, foaming and unevenness even when deep drawing is performed to a depth of 7 mm or more.
Thus, by using the molding resin sheet of the present invention, it is possible not only to obtain a molded product having a surface that is hardly damaged but also excellent in moldability, and to produce an in-mold molded product that does not have the color of printing ink or burnt. It is expected that

In consideration of the above results, as a method of setting the absolute value of the difference in glass transition temperature between the polycarbonate resin composition (A) and the acrylic resin (B) within 30 ° C., the aromatic polycarbonate (A1) And the other resin (A2) and a polymer alloy are preferably prepared to lower the glass transition temperature of the polycarbonate resin composition (A), and the other resin (A2) is aromatic. Polyester, especially copolymer polyester obtained by replacing part of ethylene glycol in polyethylene terephthalate with cyclohexanedimethanol, or copolymer polyester obtained by replacing part of terephthalic acid in polybutylene terephthalate with isophthalic acid, or A mixture of these may be preferred.

Claims

The acrylic resin (B) is a main component on one side of a base material layer having a polycarbonate resin composition (A) composed of a polymer alloy of an aromatic polycarbonate (A1) and another resin (A2) as a main component. A laminated sheet comprising a coating layer,
A molding resin sheet, wherein an absolute value of a difference in glass transition temperature between the polycarbonate resin composition (A) and the acrylic resin (B) is within 30 ° C.
2. The resin sheet for molding according to claim 1, wherein the other resin (A2) is an aromatic polyester.
The aromatic polyester is a copolymer polyester obtained by replacing a part of ethylene glycol in polyethylene terephthalate with cyclohexanedimethanol, or a copolymer polyester obtained by replacing a part of terephthalic acid in polybutylene terephthalate with isophthalic acid, Or it is a mixture of these, The resin sheet for shaping | molding of Claim 2 characterized by the above-mentioned.
A thermoformed article obtained by thermoforming the molding resin sheet according to any one of claims 1 to 3, wherein the thermoformed article is deeply drawn to a height of 5 mm or more.
A printing layer is formed on the substrate layer side of the molding resin sheet according to any one of claims 1 to 3 and thermoformed, while a molten resin is injection molded on the printing layer side to form a backing layer. An in-mold molded product.