JP6166193B2 - Resin sheet having marble pattern and method for producing the same - Google Patents

Description

  The present invention relates to a thermoplastic resin sheet having a marble pattern that has excellent color tone and flows in one direction, and a method for producing the same.

  Conventionally, various attempts have been made to mold a thermoplastic resin sheet having a marble design with high design. Usually, these resin sheets are prepared by secondary processing. For example, there is known a method of giving a high-quality pattern by printing / painting or laminating on the surface of a resin sheet. However, this method has many manufacturing steps and is expensive, and the surface pattern may be damaged or lost due to friction.

  On the other hand, a molding method using calendar processing or roll processing is also known. For example, in Japanese Patent Application Laid-Open No. 2008-87325 (Patent Document 1), a base resin composition is kneaded by roll processing, and a non-uniform thickness resin base material that becomes a marble pattern is put into a bank between rolls. A method for obtaining a marble pattern is disclosed. This document also describes an embossed resin base material and a resin base material in which unevenness is formed by laminating a resin sheet having an arbitrary shape as the resin base material. More specifically, a single-color sheet such as a circle is stuck on a single-color sheet in a zigzag pattern, or a different color resin tape is joined at an arbitrary angle with the roll rotation direction to form a resin base material that contains vinyl chloride and the like. The obtained resin composition is kneaded on the resin base material and a roll to obtain a resin sheet. However, as described above, the preparation of the resin base material requires processing such as bonding, which not only increases the production cost but also restricts the pattern to be formed.

A thermoplastic resin sheet molding method using an injection molding machine is also known. For example, in Japanese Patent Application Laid-Open No. 2009-137192 (Patent Document 2), two or more thermoplastic resins having different glass transition temperatures and color tones are introduced into a screw, and these resins are dispersed unevenly due to a difference in melt viscosity. A method for forming a marble pattern is disclosed. However, in the injection molding, since the molten resin spreads in the circumferential direction around the gate in the cavity, a flow pattern in one direction cannot be formed even if an annular pattern or a flow pattern in which the annular patterns merge can be formed. Moreover, since the resin sheet is not colored, a resin sheet excellent in color tone cannot be obtained. Furthermore, in the injection molding, productivity and mass productivity are inferior compared with the extrusion molding method.
JP 2008-87325 A (Claim 1, Examples, Paragraph [0014]) JP 2009-137192 A (Claim 1)

  Accordingly, an object of the present invention is to provide a thermoplastic resin sheet having a marble pattern that is excellent in color tone and flows in one direction, and a method for producing the same.

  Another object of the present invention is to provide a thermoplastic resin sheet having a high impact resistance and gloss, and having a marble pattern flowing in one direction, and a method for producing the same.

  Still another object of the present invention is to provide a thermoplastic resin sheet having a unique marble pattern and a method for producing the same, wherein the ground pattern and the overlapping pattern each have a flow pattern.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor has determined a predetermined first resin composition for forming a surface layer and a predetermined second resin for forming a base layer on which the surface layer is laminated. In the co-extrusion molding with the composition, a resin composition containing a styrene resin and / or an olefin resin as a base resin is used as the first and second resin compositions, and the first and second resin compositions When a colorant is contained in at least one of the resin compositions and an aliphatic polyester resin is contained in the base resin of the second resin composition, an irregular uneven flow pattern at the interface between the base layer and the surface layer As a result, it was found that a marble pattern flowing in one direction was obtained, and the present invention was completed.

  That is, the thermoplastic resin sheet having a marble pattern of the present invention comprises a surface layer formed of the first resin composition and a base layer formed of the second resin composition, and at least one surface of the base layer The surface layer is laminated, and the first resin composition includes at least one selected from a styrene resin and an olefin resin as a base resin, and the second resin composition includes a styrene resin and an olefin. At least one selected from a resin and an aliphatic polyester resin as a base resin, and at least one of the first resin composition and the second resin composition contains a colorant.

  In the first resin composition and the second resin composition, the styrene resin may contain at least an impact-resistant styrene resin. The styrene-based resin of the first resin composition may contain an impact-resistant styrene-based resin and polystyrene, and the ratio of the impact-resistant styrene-based resin and polystyrene is the former / the latter (weight ratio) = It may be about 100/0 to 20/80 (for example, 90/10 to 20/80).

  The olefin resin of the first resin composition may contain at least one selected from a polyethylene resin and a polypropylene resin. For example, the olefin resin of the first resin composition may contain metallocene polyethylene and / or metallocene polypropylene. Further, the ratio of the olefin resin and the styrene resin may be about the former / the latter = 90/10 to 10/90 (weight ratio). The polyethylene resin, the styrene resin, and / or The ratio with the polypropylene resin may be the former / the latter = 100/0 to 15/85 (weight ratio). Furthermore, the olefin resin of the second resin composition may contain metallocene polypropylene.

The aliphatic polyester resin of the second resin composition may contain a hydroxy C _2-6 alkanecarboxylic acid or a lactone homo- or copolymer thereof. In the second resin composition, the ratio of the aliphatic polyester and at least one selected from the styrene resin and the olefin resin is about the former / the latter = 3/97 to 50/50 (weight ratio). Also good.

  The colorant may be achromatic or chromatic. The proportion of the colorant may be about 0.1 to 20 parts by weight with respect to 100 parts by weight of the base resin constituting the first resin composition or the second resin composition.

  Furthermore, at least one of the first resin composition and the second resin composition may contain a compatibilizing agent, and the compatibilizing agent includes a styrene-based thermoplastic elastomer and a hydrogenated styrene-based thermoplastic. It may be at least one selected from elastomers (such as fully hydrogenated styrenic thermoplastic elastomers). The ratio of the compatibilizer is about 0 to 50 parts by weight (for example, 1 to 50 parts by weight) with respect to 100 parts by weight of the base resin constituting the first resin composition or the second resin composition. Also good.

  The thickness of the surface layer may be about 0.01 to 0.1 mm, and the ratio between the thickness of the single surface layer and the thickness of the base layer is the former / the latter = 1/99 to 50/50. Also good.

  The present invention also includes a method for producing a thermoplastic resin sheet having a marble pattern flowing in the one direction. In this method, the first resin composition and the second resin composition are coextruded, and the first resin composition is formed on at least one surface of a base layer formed of the second resin composition. A thermoplastic resin sheet having the marble pattern is manufactured by laminating surface layers formed of objects.

  In this specification, the term “marble pattern” is used synonymously with a marble pattern. “Marble pattern” and “marble pattern” mean a flowing pattern such as a flow pattern (including ink-sink pattern), a saddle pattern, and a curved pattern. Therefore, the “marble pattern flowing in one direction” usually means a form in which the pattern flows irregularly in one direction.

  Acrylic monomers and methacrylic monomers may be collectively referred to as (meth) acrylic monomers. In addition, “metallocene polyethylene” and “metallocene polypropylene” mean a polyethylene or a polyethylene copolymer prepared using a metallocene catalyst and a polypropylene or a polypropylene copolymer prepared using a metallocene catalyst, respectively.

  In the present invention, at least one of the first resin composition and the second resin composition contains a colorant, and the second resin composition contains an aliphatic polyester-based resin for coextrusion molding, It can be formed into a thermoplastic resin sheet having a marble pattern flowing in one direction and excellent color tone. In addition, a resin sheet having high impact resistance and gloss can be formed, and the aesthetic appearance can be further improved. Furthermore, by adding a colorant having a different hue to each of the first resin composition and the second resin composition, the ground pattern of the base layer and the superposed pattern of the surface layer each have a flow pattern, and a unique marble A thermoplastic resin sheet having a pattern can be obtained.

FIG. 1 is a view showing the pattern of the thermoplastic resin sheet obtained in Example 2. FIG. FIG. 2 is a view showing the pattern of the thermoplastic resin sheet obtained in Example 6. FIG.

  The thermoplastic resin sheet of the present invention is formed by coextrusion molding with a base layer formed of the second resin composition and at least one surface (single side or both sides) of the base layer formed of the first resin composition. A surface layer laminated on the base layer and the surface layer, an irregular uneven pattern is formed at the interface between the base layer and the surface layer, or a colored pattern presumed to correspond to this uneven flow pattern is formed Yes.

[Surface layer (first resin composition)]
The first resin composition contains at least one selected from a styrene resin and an olefin resin as a base resin.

(Styrene resin)
As the styrenic resin, a homopolymer or copolymer formed with a styrenic monomer as a main structural unit can be used. Examples of the styrenic monomer include styrene and styrene having an alkyl group substituted on the benzene ring (for example, vinyl toluene, vinyl xylene, p-ethyl styrene, p-isopropyl styrene, p-butyl styrene, pt-butyl). C _1-6 alkyl-substituted styrene such as styrene), styrene having a halogen atom substituted on the benzene ring (eg, chlorostyrene, bromostyrene, etc.), and α-alkyl-substituted styrene having an alkyl group substituted at the α-position (eg, α -Α-C _1-6 alkylstyrene such as methylstyrene). These styrenic monomers can be used alone or in combination of two or more. Of these monomers, styrene, vinyltoluene, α-methylstyrene and the like are usually used, and at least styrene is particularly used.

The styrenic monomer may be used in combination with a copolymerizable monomer. Examples of the copolymerizable monomer include an unsaturated polycarboxylic acid or an acid anhydride thereof (eg, maleic acid, itaconic acid or an acid anhydride thereof), an imide monomer [eg, maleimide, N -N-substituted maleimides such as N- _C1-4 alkylmaleimides, N-cyclohexylmaleimides, N-phenylmaleimides], acrylic monomers [eg (meth) acrylic acid, (meth ) (Meth) acrylic acid C _1-16 alkyl ester such as methyl acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylic acid cyclohexyl, (meth) acrylic acid phenyl, (meth) acrylic acid benzyl, (meth) acrylic acid group Glycidyl, 2-hydroxyethyl (meth) acrylate, (meth) (meth) acrylic acid hydroxyalkyl C _2-4 alkyl esters of acrylic acid 2-hydroxypropyl, and (meth) vinyl cyanide such as acrylonitrile] illustrated it can. These copolymerizable monomers can be used alone or in combination of two or more.

  The proportion of the copolymerizable monomer is, for example, 0 to 70 parts by weight, preferably 5 to 50 parts by weight, and more preferably 10 to 25 parts by weight with respect to 100 parts by weight of the styrene monomer. May be.

The styrenic resin may be an impact-resistant styrenic resin containing a rubber component (rubber-like polymer). Examples of the rubber-like polymer include diene rubber [polybutadiene (low cis type or high cis type polybutadiene), polyisoprene, styrene-butadiene copolymer, styrene-isoprene copolymer, butadiene-acrylonitrile copolymer, isobutylene. -Isoprene copolymer, styrene-isobutylene-butadiene copolymer rubber, etc.], ethylene-vinyl acetate copolymer, acrylic rubber (copolymer elastomer having polyacrylic acid C _2-8 alkyl ester as a main component), ethylene -Α-olefin copolymer [ethylene-propylene rubber (EPR), etc.], ethylene-α-olefin-polyene copolymer [ethylene-propylene-diene rubber (EPDM), etc.], urethane rubber, silicone rubber, butyl rubber, water Diene rubber (hydrogenated steel) Down - butadiene copolymer, and hydrogenated butadiene polymer) and the like. The form of the rubbery polymer may be a graft copolymer, a random copolymer, or a block copolymer. These rubbery polymers can be used alone or in combination of two or more.

  A preferred rubbery polymer is a polymer of conjugated 1,3-diene or a derivative thereof, particularly a diene rubber [polybutadiene (butadiene rubber), isoprene rubber, styrene-butadiene copolymer, etc.].

  In the rubber-containing styrene resin, the content of the rubbery polymer can be selected from the range of about 1 to 50% by weight, for example, 1 to 30% by weight, preferably 3 to 20% by weight, and more preferably 5 to 15% by weight %. If the rubber content is too high, the marble pattern formability is lowered, and if it is too low, the impact resistance is lowered.

  In the impact-resistant styrene resin, the form of the rubbery polymer dispersed in the matrix composed of the styrene resin is not particularly limited, and may be a salami structure, a core / shell structure, an onion structure, or the like. In order to improve impact resistance, the particle size of the rubber-like polymer constituting the dispersed phase may be, for example, a volume average particle size of 0.5 μm or more, for example, 0.5 to 6 μm, preferably 1 to 5 μm. More preferably, it may be about 2 to 4.5 μm. Moreover, the graft ratio with respect to a rubber-like polymer is 5-150%, Preferably it is about 10-150%.

  The weight average molecular weight (polystyrene conversion) of the styrene resin (or styrene resin constituting the matrix) is about 10,000 to 1,000,000, for example, 50, when measured by gel permeation chromatography (GPC). It may be about 000 to 500,000, preferably 100,000 to 400,000, more preferably about 200,000 to 350,000.

  Specific examples of the styrene resin include polystyrene (GPPS), styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer, acrylonitrile-styrene-methyl methacrylate copolymer, and styrene-anhydrous. Non-rubber-containing styrene resin such as maleic acid copolymer (SMA resin), impact styrene resin including impact polystyrene (HIPS), styrene-acrylonitrile-butadiene copolymer (ABS resin), α- Methylstyrene-modified ABS resin, imide-modified ABS resin, styrene-methyl methacrylate-butadiene copolymer (MBS resin), rubber component X (acrylic rubber, EPDM, ethylene-vinyl acetate copolymer, etc.) and acrylonitrile A and styrene S Such as AXS resin grafted with Unmodified styrene resin. These styrenic resins can be used alone or in combination of two or more. Among these styrene resins, a resin containing an impact resistant styrene resin including at least impact resistant polystyrene (HIPS) is preferable from the viewpoint of impact resistance.

The melt flow rate (MFR) of the impact-resistant styrene resin or rubber-containing styrene resin is a method according to JIS K 7210 (200 ° C., load 5 kgf), for example, 1 to 10 g / 10 min, preferably 1. It may be about 5 to 8 g / 10 minutes, more preferably about 2 to 5 g / 10 minutes. The melt viscosity (melt viscosity at a temperature of 220 ° C. and a shear rate of 10 sec ⁻¹ ) of the impact-resistant styrene resin or rubber-containing styrene resin is, for example, 2000 to 30000 Pa · s, preferably 3000 to 25000 Pa · s, more preferably It is about 4000 to 20000 Pa · s (particularly 4000 to 15000 Pa · s).

  The impact-resistant styrene resin or rubber-containing styrene resin (for example, impact-resistant polystyrene (HIPS)) is preferably combined with a non-rubber-containing styrene resin (for example, polystyrene (GPPS)). When the resins are combined, both fluidity and impact resistance can be achieved, and mechanical properties such as elastic modulus can be secured. The ratio of impact-resistant styrene resin or rubber-containing styrene resin to non-rubber-containing styrene resin is the former / the latter = 100/0 to 20/80 (weight ratio), preferably 90/10 to 20/80 ( (Weight ratio), more preferably 70/30 to 25/75 (weight ratio), particularly 50/50 to 30/70 (weight ratio).

(Olefin resin)
The olefin resin includes a single or copolymer of an olefin monomer. Examples of the olefin monomer include linear olefins (for example, ethylene, 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1- Α-C _3-20 linear olefins such as tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene), branched olefins (for example, isobutene, 3-methyl-1-butene, 2-methyl-1- Α-C _3- such as pentene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 3-ethyl-1-hexene ₂₀ branched chain olefins). These olefins may be used alone or in combination of two or more. Among these olefin monomers, a linear or branched α-C _2-10 olefin (preferably an α-C _2-8 olefin, more preferably an α-C _2-4 olefin) may be included. Many. In particular, it is preferable to contain ethylene and / or propylene as the main olefin monomer.

The olefin resin may be a copolymer of an olefin monomer and a copolymerizable monomer. Examples of the copolymerizable monomer include (meth) acrylic monomers (for example, (meth) acrylic acid C _1-6 alkyl esters such as methyl (meth) acrylate and ethyl (meth) acrylate, (Meth) acrylic acid hydroxy C _2-6 alkyl esters, (meth) acrylic acid glycidyl esters, (meth) acrylic acid, etc.), unsaturated dicarboxylic acids or derivatives thereof (maleic anhydride, fumaric acid, crotonic acid, etc.) And vinyl esters (eg, vinyl acetate, vinyl propionate, etc.), polymerizable nitrile compounds (eg, (meth) acrylonitrile, etc.), conjugated dienes (butadiene, isoprene, etc.), and the like. These copolymerizable monomers can be used alone or in combination of two or more. The proportion of the copolymerizable monomer is, for example, 0 to 70 parts by weight (for example, 3 to 70 parts by weight), preferably 5 to 50 parts by weight, more preferably 100 parts by weight of the olefin monomer. May be 10 to 25 parts by weight.

  As the olefin resin, for example, a polyethylene resin having ethylene as a main olefin monomer and a polypropylene resin having propylene as a main olefin monomer are preferable from the viewpoint of marble pattern formation.

The polyethylene resin may be a homopolymer or a copolymer. In the polyethylene resin, typical copolymerizable monomers include, for example, olefins such as 1-propylene, 1-butene, 1-hexene, 1-octene and 1-decene, (meth) acrylic acid C _1. Examples include _-6 alkyl esters, (meth) acrylic acid glycidyl esters, (meth) acrylic acid, and vinyl esters. In the polyethylene-based copolymer, at least α-C _3-10 linear olefin (for example, α-C _3-8 olefin) is often used among the copolymerizable monomers.

  The polyethylene copolymer (a copolymer of olefins and a copolymer of ethylene and a copolymerizable monomer) includes a random copolymer, a block copolymer, or a graft copolymer. Examples of the polyethylene resin include, for example, an ethylene-based olefin monomer or a copolymer [low density polyethylene (LDPE), medium density polyethylene, high density polyethylene (HDPE), linear low density polyethylene]. (Metallocene polyethylene, LLDPE), ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-octene-1 copolymer, ethylene-propylene-octene-1 Copolymer, ethylene- (4-methylpentene-1) copolymer, etc.], ethylene- (meth) acrylate copolymer such as ethylene-ethyl acrylate copolymer, ethylene- (meth) acrylic acid copolymer Or the ionomer etc. can be illustrated. These polyethylene resins can be used alone or in combination of two or more. Preferred polyethylene resins include olefin homopolymers or copolymers based on ethylene, such as low density polyethylene (LDPE), in particular, linear low density polyethylene (LLDPE). When a polyethylene resin is used, it is possible to form a marble pattern with clear shading, high design, and excellent gloss.

The polypropylene resin may be a homopolymer or a copolymer. In the polypropylene resin, typical copolymerizable monomers include, for example, olefins such as ethylene, 1-butene, 1-hexene, 1-octene and 1-decene, (meth) acrylic acid, maleic anhydride And vinyl esters. Of these copolymerizable monomers, α-C _2-10 linear olefins other than propylene (for example, α-C _2-8 olefins such as ethylene), maleic anhydride and the like are often used.

  The polypropylene copolymer (a copolymer of olefins and a copolymer of an olefin and a copolymerizable monomer) includes a random copolymer, a block copolymer (block polypropylene resin), or a graft copolymer. Including polymers. Examples of the polypropylene-based resin include olefin-based monomers alone or copolymers mainly composed of propylene [for example, polypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene- 1 copolymer, propylene-octene-1 copolymer, propylene-α-olefin copolymer such as propylene-ethylene-octene-1 copolymer, etc.], maleic anhydride grafted polypropylene, and the like. These polypropylene resins can be used alone or in combination of two or more. Preferable polypropylene resin is preferably a homopolymer or copolymer of an olefin monomer mainly composed of propylene, for example, polypropylene, particularly a metallocene propylene resin. When a polypropylene resin is used, a marble pattern with excellent gloss can be formed.

  The weight average molecular weight (polystyrene conversion) of the olefin resin (polyethylene resin, polypropylene resin, etc.) is selected from a range of, for example, about 10,000 to 1,000,000 when measured by GPC (solvent: dichlorobenzene). For example, it may be about 60,000 to 700,000, preferably about 80,000 to 500,000, more preferably about 100,000 to 300,000.

The melting point of the polyethylene resin is, for example, about 80 to 170 ° C, preferably 90 to 140 ° C, and more preferably about 100 to 130 ° C. The melt flow rate (MFR) of the polyethylene-based resin is a method according to JIS K 7210 (temperature 190 ° C., load 2.16 kgf), for example, 0.2 to 10 g / 10 minutes, preferably 0.5 to 5 g / It may be about 10 minutes, more preferably about 1 to 3 g / 10 minutes (particularly 1.2 to 3 g / 10 minutes). The polyethylene resin has a melt viscosity (melt viscosity at a temperature of 220 ° C. and a shear rate of 10 sec ⁻¹ ) of, for example, 1000 to 20000 Pa · s, preferably 1500 to 5000 Pa · s, and more preferably about 2000 to 3000 Pa · s.

The melting point of the polypropylene resin is, for example, about 140 to 190 ° C, preferably about 155 to 175 ° C, and more preferably about 160 to 170 ° C. The melt flow rate (MFR) of the polypropylene resin is a method according to JIS K 7210 (temperature 230 ° C., load 2.16 kgf), for example, 0.2 to 20 g / 10 minutes, preferably 0.5 to 10 g / It may be about 10 minutes, more preferably about 1 to 5 g / 10 minutes (particularly 1.5 to 3 g / 10 minutes). The melt viscosity (melt viscosity at a temperature of 220 ° C. and a shear rate of 10 sec ⁻¹ ) of the polypropylene resin is, for example, about 1000 to 10,000 Pa · s, preferably about 1500 to 5000 Pa · s, and more preferably about 2000 to 3000 Pa · s.

  A polyethylene resin (such as LLDPE) and a polypropylene resin (such as metallocene polypropylene) may be used in combination. When this polyethylene resin and polypropylene resin are combined, a styrene resin may be used in combination, but the styrene resin is not necessarily required. The ratio of the polyethylene resin to the styrene resin and / or the polypropylene resin (in the case where both the styrene resin and the polypropylene resin are included) is, for example, the former / the latter (weight ratio) = 100 / 0-15 / 85 (for example, 85 / 15-15 / 85), preferably 70 / 30-20 / 80, more preferably about 45 / 65-25 / 75. In addition, it seems that when a polyethylene resin and a polypropylene resin are combined, a flow pattern is formed to form a phase separation structure (for example, a sea-island structure, a co-continuous phase structure, particularly at least a co-continuous phase structure).

  Olefin resins (for example, LLDPE, metallocene polypropylene, etc.) and styrene resins (for example, impact-resistant styrene resins, rubber-containing styrene resins and / or non-rubber-containing styrene resins, etc.) may be used alone. Well, they may be used in combination. When used in combination, mechanical properties such as elastic modulus and impact resistance can be improved. In particular, it seems to form a flow pattern for forming a phase separation structure (for example, sea-island structure, co-continuous phase structure, particularly at least a co-continuous phase structure) between the olefin resin and the styrene resin. The ratio of the olefin resin and the styrene resin can be selected from the range of the former / the latter (weight ratio) = 100/0 to 0/100, and 90/10 to 10/90 (for example, 60/40 to 15/85). ), Preferably 80/20 to 20/80 (for example, 50/50 to 20/80), more preferably about 70/30 to 25/75 (for example, 40/60 to 25/75).

  In addition, in the surface layer formed with the 1st resin composition, the base resin comprised with a styrene resin and / or an olefin resin seems to form a phase-separation structure. The phase separation structure may be a sea-island structure, but at least a co-continuous phase structure is formed, and this phase separation structure seems to form an uneven flow pattern at the interface with the base layer.

[Base layer (second resin composition)]
The base resin constituting the second resin composition contains a resin incompatible with the base resin of the surface layer (for example, an aliphatic polyester resin) from the viewpoint of marble pattern formation, and has sheet formability. From this point of view, the base resin constituting the first resin composition and a resin having adhesiveness (for example, a styrene resin, an olefin resin, etc.) are included. That is, the second resin composition contains at least one selected from styrene resins and olefin resins and an aliphatic polyester resin as a base resin.

(Aliphatic polyester resin)
The aliphatic polyester resin includes a polycondensation of an aliphatic dicarboxylic acid component and an aliphatic diol component (first ester forming component), a polycondensation of an aliphatic oxycarboxylic acid and / or a lactone (second ester forming component), A homopolyester or a copolyester obtained by polycondensation of the first ester-forming component and the second ester-forming component may be mentioned.

Examples of the aliphatic dicarboxylic acid component include aliphatic dicarboxylic acids having about 2 to 12 carbon atoms such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, and sebacic acid. These dicarboxylic acid components can be used alone or in combination of two or more. A preferred aliphatic dicarboxylic acid component is a C _2-10 alkane dicarboxylic acid such as oxalic acid or succinic acid (eg, C _2-6 alkane dicarboxylic acid, particularly C _2-4 alkane dicarboxylic acid).

Examples of the aliphatic diol component include linear or branched C ₂ such as ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, and hexanediol. _-10 alkanediol; polyoxy C _2-4 alkylene glycol having a oxyalkylene unit having a repeating number of about 2 to 5 [poly (oxy-C _2-4 alkylene) glycol such as diethylene glycol] and the like. These diol components can be used alone or in combination of two or more. Preferred diol components are linear or branched C _2-6 alkane diols such as ethylene glycol and 1,4-butane diol (for example, linear C _2-4 alkane diols).

Examples of the aliphatic oxycarboxylic acid include glycolic acid, lactic acid, oxypropionic acid, oxybutyric acid (such as 3-hydroxybutanoic acid), hydroxyvaleric acid (such as 3-hydroxyvaleric acid), hydroxycaproic acid, and hydroxyhexanoic acid. Examples thereof include oxy C _2-6 alkanecarboxylic acid such as (3-hydroxyhexanoic acid and the like). These oxycarboxylic acids can also be used alone or in combination of two or more. Preferred oxycarboxylic acids are oxy C _2-6 alkane carboxylic acids such as glycolic acid and lactic acid (eg, oxy C _2-4 alkane carboxylic acids). Examples of lactones include C _4-12 lactones such as butyrolactone, valerolactone, and caprolactone.

Specifically, as the aliphatic polyester-based resin, for example, a polyester-based resin obtained by polycondensation of the first ester-forming component (for example, polyethylene oxalate, polybutylene oxalate, polyneopentylene ogiza) Poly C _2-6 alkylene succinates such as polyethylene succinate, polybutylene succinate, poly C _2-6 alkylene succinates such as poly neopentylene succinate; polyethylene adipate, polybutylene adipate, poly neopentylene A poly C _2-6 alkylene adipate such as adipate), a polyoxycarboxylic acid resin obtained by polycondensation of the second ester-forming component (for example, polyglycolic acid, polylactic acid, lactic acid-glycolic acid copolymer, etc.) , Polylactone resins (for example, And poly _{C 4-12} lactone resins such as polycaprolactone), and the like. Specific examples of the copolyester include, for example, a copolyester using two kinds of dicarboxylic acid components (for example, poly C _2-4 alkylene such as polyethylene succinate-adipate copolymer resin and polybutylene succinate-adipate copolymer resin). Succinate-adipate copolymer resin), copolyesters obtained from a dicarboxylic acid component, a diol component, and a lactone (for example, polycaprolactone-polybutylene succinate copolymer resin). These aliphatic polyester resins can be used alone or in combination of two or more.

The aliphatic polyester resin is preferably a biodegradable polyester resin from the viewpoint of reducing environmental burden. The aliphatic polyester resin is preferably a crystalline polyester resin. Examples of such polyester resins include the polyester resins exemplified above, for example, poly (oxy C _2-6 alkane carboxylic acid) resins such as polyglycolic acid resins, polylactic acid resins, lactic acid-glycolic acid copolymers, and the like. Examples include (alkylene succinate) resins.

  The crystalline aliphatic polyester-based resin can form a marble pattern more effectively because an irregular uneven pattern is generated at the interface between the surface layer and the base layer due to the pressure acting on the surface layer in melt lamination molding.

  In the polylactic acid-based resin, lactic acid includes L-lactic acid, D-lactic acid, and DL-lactic acid (racemic), and these lactic acids can be used alone or in combination of two or more. The crystallinity can be adjusted by the content of L-lactic acid, and the higher the crystallinity, the better. For example, the ratio of L-lactic acid in the entire lactic acid may be 70% by weight or more (preferably 80% by weight or more, more preferably 90 to 100% by weight). Moreover, as long as it contains lactic acid as a main component, it may contain a monomer copolymerizable with lactic acid.

Examples of the monomer copolymerizable with oxy C _2-6 alkanecarboxylic acid such as lactic acid include, for example, polyols (for example, the dicarboxylic acid component, the diol component, the aliphatic oxycarboxylic acid and the lactone). C _3-10 alkane polyols such as glycerin and pentaerythritol).

The ratio of oxy C _2-6 alkane carboxylic acid (such as lactic acid) in the poly (oxy C _2-6 alkane carboxylic acid) based resin such as polylactic acid based resin is, for example, 50 mol% or more, preferably 80% in all the structural units. ˜100 mol%, more preferably about 90 to 100 mol%.

  The weight average molecular weight (polystyrene conversion) of the aliphatic polyester resin (polylactic acid resin, etc.) can be selected from the range of about 10,000 to 1,000,000 when measured by gel permeation chromatography (GPC). For example, it is about 60,000 to 700,000, preferably about 80,000 to 500,000, more preferably about 100,000 to 300,000.

The melting point of the aliphatic polyester resin (polylactic acid resin or the like) is, for example, 100 to 220 ° C, preferably 120 to 200 ° C, more preferably about 150 to 175 ° C. The melt flow rate (MFR) of the aliphatic polyester-based resin (polylactic acid-based resin or the like) is a method according to JIS K 7210 (190 ° C., load 2.16 kgf), for example, 0.5 to 15 g / 10 min. Preferably, it may be about 1 to 10 g / 10 minutes, more preferably about 2 to 6 g / 10 minutes. The melt viscosity (melt viscosity at a temperature of 220 ° C. and a shear rate of 10 sec ⁻¹ ) of the aliphatic polyester resin (polylactic acid resin or the like) is, for example, 150 to 4000 Pa · s, preferably 300 to 3000 Pa · s, more preferably It is about 400 to 1000 Pa · s.

  The aliphatic polyester resin may be incompatible with both the base resin of the first resin composition and the styrene resin and olefin resin of the second resin composition. By including such an aliphatic polyester-based resin, an uneven marble pattern can be formed at the interface between the base layer and the surface layer, or a high-quality marble pattern can be formed.

(Styrene resin)
As the styrenic resin, the same styrenic resin as in the first resin composition can be used. The styrenic resin of the second resin composition preferably contains at least an impact-resistant styrenic resin (such as HIPS) from the viewpoint of impact resistance.

(Olefin resin)
As the olefin resin, the same olefin resin as the first resin composition can be used. The olefin resin of the second resin composition may be a polyethylene resin, but is preferably a polypropylene resin (particularly a metallocene polypropylene).

  In the second resin composition, an impact-resistant styrenic resin (such as HIPS) and polystyrene may be used in combination, and the ratio thereof may be the same as that of the first resin composition. In the second resin composition, an impact-resistant styrene resin (such as HIPS) is often used as the styrene resin. Further, the compatibilizer and the ratio thereof may be the same as those of the first resin composition. Furthermore, a styrene resin and an olefin resin may be combined, a polyethylene resin and a polypropylene resin may be combined, and the ratio of these components may be the same as that of the first resin composition. .

  The ratio (weight ratio) of the aliphatic polyester resin and at least one selected from styrene resin and olefin resin can be selected from the range of the former / the latter = 3/97 to 50/50, for example, 5 / 95-40 / 60 (for example, 7 / 93-30 / 70), preferably 8 / 92-25 / 75 (for example, 10 / 90-25 / 75), more preferably about 15 / 85-20 / 80 It may be.

[Melt flow rate (MFR) of resin of first and second resin compositions]
Both the MFRs of the resins of the first and second resin compositions use a melt indexer (type; L207) manufactured by Takara Kogyo Co., Ltd., and conform to JIS K7210, and adjust the temperature and pressure according to the type of resin. Can be set and measured. The polylactic acid resin and the polyethylene resin can be measured at 190 ° C. and a load of 2.16 kgf, the polystyrene resin can be measured at 200 ° C. and the load of 5 kgf, and the polypropylene resin can be measured at 230 ° C. and a load of 2.16 kgf. When measured under such conditions, the melt flow rate (MFR) is 0.5 to 25 (g / 10 min), preferably 1 to 20 (g / 10 min), more preferably 1.2 to 16 (G / 10 minutes).

[Compatibilizer]
At least one of the first resin composition and the second resin composition may contain a compatibilizer. Various types of compatibilizers can be selected, and they may be non-reactive or reactive compatibilizers. Examples of the non-reactive compatibilizer include (A) a copolymer of a styrene monomer constituting a styrene resin and a conjugated diene compound (such as a random copolymer or a graft copolymer), and (B). Examples thereof include a block copolymer containing a block mainly composed of a styrene-based monomer (such as a polystyrene block) and a block mainly composed of a conjugated diene compound (such as a polybutadiene block) or a hydrogenated product thereof. Examples of reactive compatibilizers include (C) epoxy group-containing compounds (such as (meth) acrylic acid glycidyl ester), carboxyl group-containing compounds (such as (meth) acrylic acid), and acid anhydride-containing compounds (maleic anhydride). And the like, and a copolymer of at least one selected from styrenic monomers. These compatibilizers can be used alone or in combination of two or more.

  Examples of the copolymer (A) include a styrene-butadiene copolymer. The block copolymer (B) includes a styrene thermoplastic elastomer (styrene-butylene-styrene (SBS) copolymer) and / or a hydrogenated styrene thermoplastic elastomer (styrene-ethylene-butylene-styrene (SEBS). ) Copolymer) and the like. As the compatibilizing agent for the first resin composition and / or the second resin composition, the block copolymer (B) is preferable, and in particular, the SBS block copolymer and / or the SEBS block copolymer are preferable.

  The proportion of the compatibilizer is from 0 to 100 parts by weight (for example, 0 to 50 parts by weight) with respect to 100 parts by weight of the base resin in the first resin composition and / or the second resin composition. For example, even if it is about 1 to 50 parts by weight (for example, 2 to 30 parts by weight), preferably 3 to 25 parts by weight, more preferably 5 to 20 parts by weight (particularly 10 to 15 parts by weight). Good. When a compatibilizing agent is added, it is possible to suppress partial variations in the marble pattern and improve impact resistance, mechanical properties, gloss, and the like.

[Colorant]
The first resin composition and / or the second resin composition contains a colorant. The colorant may be added to one of the first resin composition and the second resin composition, and may be added to both, but when added to at least the first resin composition that forms the surface layer, A marble pattern with better color tone can be formed. Moreover, when a colorant having a different hue is added to each resin composition, it is added to the first resin composition against the background of the flow pattern (ground pattern) of the base layer due to the colorant added to the second resin composition. The flow pattern (overlapping pattern) on the surface layer by the colorant overlaps, and a unique marble pattern can be formed. Moreover, in the form in which the first surface layer and the second surface layer are laminated via the base layer, the resin composition forming the first surface layer and the resin composition forming the second surface layer have different hues. When a colorant is contained, different flow patterns can be formed on the front and back surfaces of the resin sheet. Therefore, a marble pattern having various hues can be formed by selecting the colorant-containing layer, the type of the colorant, and the like.

  The colorant may be a dye (oil-soluble dye, reactive dye, etc.), or an organic or inorganic pigment. The colorant may be an achromatic colorant [white colorant (such as titanium oxide) or black colorant (such as carbon black)], and chromatic colorant (red, orange, yellow, green, Blue, indigo, and purple colorants) may be used. These colorants can be used alone or in combination of two or more. Furthermore, you may use a masterbatch with much content for adjustment of content of a coloring agent. Of these colorants, chromatic colorants (for example, organic or inorganic pigments) are preferred.

  The ratio of the colorant is, for example, 0.1 to 20 parts by weight (for example, 0.2 to 15 parts by weight with respect to 100 parts by weight of the base resin of the first resin composition and / or the second resin composition). ), Preferably 0.3 to 10 parts by weight (eg 0.5 to 7 parts by weight), more preferably about 1 to 5 parts by weight (eg 1.5 to 3 parts by weight).

  The first resin composition and / or the second resin composition may contain various additives such as stabilizers (antioxidants, ultraviolet absorbers, light resistance stabilizers, heat stabilizers, etc.), electrification Inhibitors, flame retardants (phosphorous flame retardants, halogen flame retardants, inorganic flame retardants, etc.), flame retardant aids, impact resistance improvers, fluidity improvers, reinforcing materials (fillers etc.), nucleating agents, lubricants Alternatively, it may contain a sliding agent (particulate sliding agent such as spherical resin particles), a wax, a plasticizer, a release agent, a hue improver, a dispersant, an antibacterial agent, an antiseptic, and the like. These additives can be used alone or in combination of two or more.

[Thermoplastic resin sheet]
The thermoplastic resin sheet of the present invention includes a surface layer formed of the first resin composition and a base layer formed of the second resin composition, and the surface layer is laminated on at least one surface of the base layer. It only has to be. That is, a two-type two-layer structure in which the surface layer is laminated on one surface of the base layer, or a two-type three-layer structure in which the surface layer is laminated on both surfaces of the base layer may be used. In this two-kind three-layer structure, a marble pattern can be formed on both surfaces of the resin sheet.

  The thickness of the base layer is not particularly limited and can be appropriately selected depending on the application. The thickness of the surface layer can be selected from the range of 0.01 to 0.1 mm, for example, 0.02 to 0.08 mm, preferably 0.03 mm to 0.07 mm, more preferably about 0.04 mm to 0.06 mm. May be. In addition, when the thickness of the surface layer is too large, the uneven pattern formed at the interface between the base layer and the surface layer is not reflected, or the marble pattern is hardly formed. Therefore, a strong marble pattern can be obtained by adjusting the thickness of the surface layer.

  The thickness ratio between the surface layer (single surface layer) and the base layer is only required to be able to form each layer and sheet having a uniform thickness. For example, the former / the latter = 1/99 to 50/50, preferably 5/95 to 30 / 70, more preferably about 7/93 to 10/90.

  The resin sheet of the present invention is excellent in mechanical properties such as impact resistance and elastic modulus, in addition to a highly designable marble pattern.

  When the resin sheet of the present invention is measured using a DuPont impact measuring instrument (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the DuPont impact strength (impact resistance) is 0.5 J or more (for example, 0.5 to 1.5J), preferably 0.7 to 1.4 J, more preferably about 0.9 to 1.3 J.

  The resin sheet of the present invention was measured with Tensilon (trade name “RTA500”, manufactured by Orientec Co., Ltd.) using a sample sheet obtained by punching a No. 2 dumbbell according to JIS K 7113 to obtain a sample sheet. The tensile elastic modulus in the flow direction (MD direction) of the sheet is 500 to 3000 MPa (for example, 700 to 2700 MPa), preferably 1000 to 2500 MPa, and more preferably about 1500 to 2000 MPa.

[Method for producing thermoplastic resin sheet]
The thermoplastic resin sheet of the present invention can be prepared by kneading or mixing each component to prepare a first resin composition and a second resin composition, and coextruding each resin composition. For kneading each resin composition, for example, conventional melt mixing such as a mixer such as a Henschel mixer or a ribbon mixer capable of dry mixing each component, a single or twin screw extruder, a Banbury mixer, a kneader, a mixing roll, etc. The machine can be used. Each resin composition may be in the form of pellets.

  For coextrusion molding, a multi-hold die can be used. For example, a thermoplastic resin sheet can be produced by an extrusion method [flat die, T die, circular die, etc.] method, inflation method, etc.

  Specifically, each of the first resin composition and the second resin composition is put into an extruder and melt-mixed (melt kneading at a temperature of about 210 to 230 ° C.), and each resin composition is placed in a die. A thermoplastic resin sheet having a marble pattern that flows in one direction can be obtained by merging and stacking and extruding from a die. Such a coextrusion method can form a thin surface layer and is suitable for forming a marble pattern. The coextrusion molding method is excellent in mass productivity. Among these co-extrusion methods, the T-die method and the inflation method, particularly the co-extrusion T-die method is preferable.

  In such a co-extrusion method, stress is applied to the interface between the base layer and the surface layer along with extrusion from the die lip, the compatibility between the base layer and the surface layer at the interface, and the compatibility of the resin components of each resin composition It seems that a concavo-convex pattern is formed on the interface due to such factors. A flow pattern (especially an irregular flow pattern) in which the pattern flows in one direction (extrusion direction) may be formed because such a concavo-convex pattern is manifested by the colorant.

  Since the thermoplastic resin sheet having a marble pattern of the present invention is excellent in design, it can be used for flooring materials, interior materials, exterior materials and the like. Moreover, since it is excellent in moldability, it can be secondarily formed by a conventional method such as vacuum forming or pressure forming, and can be used for containers (food containers such as trays, cosmetic containers, etc.), daily necessities, miscellaneous goods and the like. In particular, it is useful for preparing molded products that require design properties, such as cosmetic containers and interiors.

  In addition, when disposing of such a mass-produced container, a large amount of carbon dioxide is generated. However, in the present invention, an aliphatic polyester resin (polylactic acid or the like) of biomass material is used, so that carbon dioxide is generated. The amount can be suppressed, and it is also useful from the viewpoint of reducing the environmental load.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the content of the symbol of each component used in the Example and the evaluation method of each evaluation item are as follows.

[Contents of abbreviations for each component]
HIPS: impact-resistant styrene resin (manufactured by Toyo Styrene Co., Ltd., trade name “Toyostyrene E640”, MFR (temperature 200 ° C., load 5 kgf): 2.4 g / 10 min)
GPPS: Polystyrene (made by Toyo Styrene Co., Ltd., trade name “Toyostyrene HRM12”, MFR (temperature 200 ° C., load 5 kgf): 5.5 g / 10 min)
LLDPE: linear low density polyethylene (manufactured by Prime Polymer Co., Ltd., trade name “Neozex 0144N”, MFR (temperature 190 ° C., load 2.16 kgf): 1.2 g / 10 min)
Block PP-1: Polypropylene (manufactured by Nippon Polypro Co., Ltd., trade name “Novatech PP BC2E”, MFR (temperature 230 ° C., load 2.16 kgf): 16 g / 10 min)
Block PP-2: Polypropylene (manufactured by Nippon Polypro Co., Ltd., trade name “Novatech PP EC7”, MFR (temperature 230 ° C., load 2.16 kgf): 1.5 g / 10 min)
Metallocene PP: Metallocene polypropylene (manufactured by Nippon Polypro Co., Ltd., trade name “Wintech WFX6”, MFR (temperature 230 ° C., load 2.16 kgf): 2.1 g / 10 min)
SBS: Styrene-butadiene block copolymer (manufactured by Asahi Kasei Chemicals Corporation, trade name “Tufprene 126S”)
SEBS: Styrene-ethylene-butadiene block copolymer (manufactured by Asahi Kasei Chemicals Corporation, trade name “Tuftec H1043”)
MB-1 for PS: Master batch for polystyrene (manufactured by Sankyo Chemical Industry Co., Ltd., trade name “SCPSM66154 Violet (Z)”, pigment content 9.9% by weight)
MB-2 for PS: Masterbatch for polystyrene (manufactured by Sankyo Chemical Industry Co., Ltd., trade name “SCPSM64848 Brown (Z)”, pigment content 11.3 wt%)
MB-3 for PS: Masterbatch for polystyrene (manufactured by Sankyo Chemical Industry Co., Ltd., trade name “SCPSM64264 Red (Z)”, pigment content 10.0% by weight)
MB for PP: Master batch for polypropylene (manufactured by Sankyo Chemical Industry Co., Ltd., trade name “SCPPM64261 Red (Z)”, pigment content 11.6% by weight)
PLA: Polylactic acid (manufactured by Nature Works, trade name “4032D”, MFR (temperature 190 ° C., load 2.16 kgf): 4.6 g / 10 min)
[Evaluation of marble pattern]
○: The shading of the marble pattern is clear and the design is excellent. △: The shading has a slight shading and the design is high. ×: The shading of the marble pattern is not seen and the design is poor. Evaluation]
○: The gloss is clear Δ: Some gloss is present ×: There is no gloss and it is matte [Gloss value]
Each sheet obtained in Examples and Comparative Examples was measured for 60 ° specular glossiness using TC-108DP / A manufactured by Tokyo Denshoku.

[Shock resistance]
Using a DuPont impact measuring instrument (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the impact resistance (DuPont test) of each sheet obtained in Examples and Comparative Examples was measured.

[Tensile properties]
Using each sheet obtained in the examples and comparative examples, No. 2 dumbbells according to JIS K 7113 were punched out to obtain sample sheets. Using this sample sheet, the tensile elastic modulus was measured at a test speed of 50 mm / min with Tensilon (trade name “RTA500” manufactured by Orientec Co., Ltd.).

[Examples 1 to 12 and Comparative Example 1]
Multi-layer extruder with feed block method (2 types and 3 layers extruder) (Pura Giken Co., Ltd., “General-purpose horizontal extruder (PG-65-32 type), moving horizontal extruder (PEX50-28-H type)”) ), The mixture of the second resin composition shown in Table 1 forming the base layer is supplied at a cylinder temperature of 210 ° C. to the first single-screw extruder (screw diameter 65 mm, L / D = 32, screw rotation speed 80 rpm). Then, the mixture of the first resin composition shown in Table 1 for forming the surface layer is supplied to the second single-screw extruder (screw diameter 50 mm, L / D = 28, screw rotation speed 40 rpm) at a cylinder temperature of 210 ° C. Then, in the feed block, the surface layers were merged and laminated on both surfaces of the base layer, and extruded into a sheet by the T-die casting method. It cooled to 40 degreeC with the touch roll method, the taking-up speed was adjusted so that the thickness of a layer might be 0.5-0.6 mm, and the resin sheet which laminated | stacked the surface layer on both surfaces of the base layer was prepared. In addition, the thickness of a base layer is 350-450 micrometers, and the thickness of each surface layer is 20-60 micrometers. The results are shown in Table 1.

  As shown in Comparative Example 1, a marble pattern cannot be formed unless an aliphatic polyester resin is contained in the second resin composition (base layer).

  As shown in Examples 1 to 12, the base resin constituting the first resin composition (surface layer) is at least one selected from styrene resins and olefin resins, and the second resin composition When at least one selected from styrene-based resins and olefin-based resins is used as the base resin constituting the product (base layer), a marble pattern having excellent design properties can be obtained. Further, the resin sheets obtained in the examples are excellent in impact resistance and tensile properties.

  In addition, as shown in Examples 1 and 8, the colorant may be added to one of the first resin composition (surface layer) and the second resin composition (base layer). When colorants having different hues are added to both resin compositions, a unique marble pattern in which a purple flow pattern overlaps with a red flow pattern as a background is obtained.

  As shown in Examples 1 to 12, the resin composition containing LLDPE and metallocene PP improves the gloss of the resin sheet.

In addition, the pattern of the thermoplastic resin sheet obtained in Example 2 is shown in FIG. 1, and the pattern of the thermoplastic resin sheet obtained in Example 6 is shown in FIG.

Claims (16)

  A thermoplastic resin comprising a surface layer formed of a first resin composition and a base layer formed of a second resin composition, the surface layer being laminated on at least one surface of the base layer, and having a marble pattern It is a sheet, and the first resin composition includes at least one selected from a styrene resin and an olefin resin as a base resin, and the second resin composition is selected from a styrene resin and an olefin resin. A marble pattern that flows in one direction, including at least one selected from the group consisting of an aliphatic polyester-based resin as a base resin, and at least one of the first resin composition and the second resin composition includes a colorant. A thermoplastic resin sheet.   The thermoplastic resin sheet having a marble pattern according to claim 1, wherein the styrenic resins of the first resin composition and the second resin composition contain at least an impact-resistant styrenic resin.   The styrene resin of the first resin composition includes an impact-resistant styrene resin and polystyrene, and the olefin resin of the first resin composition is at least one selected from a polyethylene resin and a polypropylene resin. A thermoplastic resin sheet having a marble pattern according to claim 1 or 2.   The marble pattern according to any one of claims 1 to 3, wherein the olefin resin of the first resin composition contains metallocene polyethylene and / or metallocene polypropylene, and the olefin resin of the second resin composition contains metallocene polypropylene. A thermoplastic resin sheet.   The marble pattern according to any one of claims 1 to 4, wherein in the first resin composition, the ratio of the olefin resin and the styrene resin is the former / the latter = 90/10 to 10/90 (weight ratio). A thermoplastic resin sheet.   The ratio of the polyethylene resin and the styrene resin and / or polypropylene resin in the first resin composition is the former / the latter = 100/0 to 15/85 (weight ratio). A thermoplastic resin sheet having the marble pattern according to claim 1.   The marble pattern according to any one of claims 3 to 6, wherein in the first resin composition, the ratio of the impact-resistant styrenic resin and polystyrene is the former / the latter = 90 / 10-20 / 80 (weight ratio). A thermoplastic resin sheet. The thermoplastic resin having a marble pattern according to any one of claims 1 to 7, wherein the aliphatic polyester-based resin of the second resin composition contains a hydroxy C _2-6 alkanecarboxylic acid or a lactone homopolymer or copolymer thereof. Resin sheet.   In the second resin composition, the ratio of the aliphatic polyester resin and at least one selected from styrene resin and olefin resin is the former / the latter = 3/97 to 50/50 (weight ratio). Item 9. A thermoplastic resin sheet having a marble pattern according to any one of Items 1 to 8.   The thermoplastic resin sheet having a marble pattern according to any one of claims 1 to 9, wherein the colorant is a colorant having a chromatic color.   The ratio of the coloring agent is 0.1 to 20 parts by weight with respect to 100 parts by weight of the base resin constituting the first resin composition or the second resin composition. A thermoplastic resin sheet having a marble pattern.   The thermoplastic resin sheet having a marble pattern according to any one of claims 1 to 11, wherein at least one of the first resin composition and the second resin composition contains a compatibilizing agent.   The thermoplastic resin sheet having a marble pattern according to claim 12, wherein the compatibilizing agent is at least one selected from a styrene-based thermoplastic elastomer and a hydrogenated styrene-based thermoplastic elastomer.   The proportion of the compatibilizer is 1 to 50 parts by weight with respect to 100 parts by weight of the base resin constituting the first resin composition or the second resin composition. A thermoplastic resin sheet having a marble pattern.   The thickness of the surface layer is 0.01 to 0.1 mm, and the ratio of the thickness of the single surface layer and the thickness of the base layer is the former / the latter = 1/99 to 50/50. A thermoplastic resin sheet having a marble pattern. A surface layer formed of the first resin composition on at least one surface of a base layer formed of the second resin composition by co-extrusion molding of the first resin composition and the second resin composition In which the first resin composition includes at least one selected from a styrene-based resin and an olefin-based resin as a base resin. The resin composition of 2 includes at least one selected from a styrene resin and an olefin resin and an aliphatic polyester resin as a base resin, and the first resin composition and the second resin composition. A method for producing a thermoplastic resin sheet having a marble pattern flowing in one direction, containing a colorant in at least one of them.