Laminate sheet and method for manufacturing the same, printed matter, and molded article

Abstract

To provide a laminate sheet which has good ink adhesion and laser machinability, and is excellent in sustainability.SOLUTION: A laminate sheet (1) has a base material layer (11), and a surface layer (21) laminated on at least one surface of the base material layer (11), wherein the surface layer contains a styrenic copolymer (S), the base material layer is composed of a methacrylic resin composition (MR) containing a methacrylic resin (M) containing 80 to 100 mass% of a methyl methacrylate unit and a styrenic copolymer (S), the base material layer has a complete compatible structure of the styrenic copolymer (S) and the methacrylic resin (M), or a sea-island structure such that a plurality of particulate island phases containing the styrenic copolymer (S) are dispersed in a sea phase containing the methacrylic resin (M), and the maximum diameter of the plurality of particulate island phases is more than 0 nm and 50 nm or less, and a ratio of the total thickness of the surface layer to the total thickness of the laminate sheet is 1 to 20%.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a laminated sheet, a manufacturing method thereof, a printed matter, and a molded article. [Background technology]

[0002] Inkjet printing, which can process digital images on a print medium using a computer, is becoming more and more popular as more types of printable media are being used. For example, it is now widely used in a variety of fields, including printing, advertising, sign displays, events, amusement, architecture, and interior design. Resin sheets are an example of a printing medium other than paper. Unlike paper, resin sheets are highly water-resistant and durable, and can also be made transparent.

[0003] After inkjet printing, the resin sheet for inkjet printing can be cut using a laser and an NC router, etc., as necessary, to form it into a desired shape. The molded product thus obtained can be preferably used for miscellaneous goods and fixtures such as key holders. A method for cutting a resin sheet using a laser is disclosed in claim 1 of Patent Document 1, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-055348 A [Patent Document 2] JP 2018-94843 A [Patent Document 3] JP 2021-160119 A Summary of the Invention [Problem to be solved by the invention]

[0005] In applications such as miscellaneous goods and fixtures such as key holders, methacrylic resins are preferably used as the base resin of the resin sheet for inkjet printing from the viewpoints of transparency and ink color development. As the ink for inkjet printing, ultraviolet (UV) curable inks and the like are preferably used. However, methacrylic resins tend not to have good adhesion to inkjet printing inks such as UV curable inks. Examples of components that have good adhesion to inkjet printing inks such as UV curable inks include styrene copolymers.

[0006] In general, in laser cutting, depending on the material of the workpiece, when the workpiece is melted and evaporated by the irradiation of laser light, the evaporated gas may cause an unpleasant odor or smoke. In addition, after the laser cutting is completed, when the melted part cools and solidifies again, the evaporated gas may adhere to the cut surface, resulting in poor appearance of the cut surface. Methacrylic resins are less likely to cause the above problems due to evaporated gas (unpleasant odor or smoke due to evaporated gas, and poor appearance of the cut surface due to the adhesion of evaporated gas), and tend to have good laser cutting processability. In contrast, styrene copolymers having an aromatic ring structure in the molecule are more likely to cause the above problems due to evaporated gas (unpleasant odor or smoke due to evaporated gas, and poor appearance of the cut surface due to the adhesion of evaporated gas), and tend to have poor laser cutting processability.

[0007] Patent Documents 2 and 3 disclose a laminate sheet having a base layer containing a methacrylic resin and a surface layer containing a styrene copolymer such as a methyl methacrylate-styrene copolymer (MS resin), and having good ink adhesion and laser cutting processability (Claim 1 in Patent Document 2, Claim 1 in Patent Document 3). This laminate sheet can be preferably produced by coextrusion molding.

[0008] In general, in the production of (co)extrusion molded sheets and molded products using the same, there are defective products that arise when the extrusion molding production line is started up, scraps generated by trimming both ends of the sheet, defective products that are determined not to meet product standards in quality inspections for defects and foreign bodies, and scraps generated by cutting the sheet. In recent years, efforts toward a sustainable society have been progressing, and it is preferable to effectively reuse the above-mentioned defective products and scraps as rework materials rather than disposing of them.

[0009] In the laminated sheets disclosed in Patent Documents 2 and 3, it is considered that a laminated sheet manufactured in the past containing a methacrylic resin and a styrene copolymer such as MS resin is used as a base layer material as a rework material. However, in general, a styrene copolymer such as MS resin is not compatible with a methacrylic resin, and there is a refractive index difference between these resins, so that a laminated sheet using the above-mentioned rework material as a base layer material may have a low transparency and become cloudy. In fact, Patent Document 3 describes that "in order to suppress the occurrence of cloudiness and maintain transparency, the styrene content in the base layer is preferably 1 mass% or less, more preferably 0.85 mass% or less" (paragraph 0171). In Patent Document 3, the preferred styrene content in the base layer is very low. In addition, this document does not disclose an example in which a laminated sheet manufactured in the past containing a methacrylic resin and a styrene copolymer such as MS resin is used as a rework material. It is preferable to be able to use more rework material as a base layer material.

[0010] The present disclosure has been made in consideration of the above problems, and aims to provide a laminate sheet that has good ink adhesion and laser cutting processability and is highly sustainable. [Means for solving the problem]

[0011] The present disclosure provides the following laminate sheets [1] to

[12] , a manufacturing method thereof, a printed matter, and a molded article. [1] A laminated sheet having a base layer and a surface layer laminated on at least one side of the base layer, The surface layer contains a styrene-based copolymer (S), the base layer is made of a methacrylic resin composition (MR) containing a methacrylic resin (M) containing 80 to 100 mass% of methyl methacrylate units and a styrene copolymer (S); the base layer has a completely miscible structure of the styrene copolymer (S) and the methacrylic resin (M), or a sea-island structure in which a plurality of particulate island phases containing the styrene copolymer (S) are dispersed in a sea phase containing the methacrylic resin (M), and the maximum diameter of the plurality of particulate island phases is more than 0 nm and not more than 50 nm; A laminate sheet, wherein the ratio of the total thickness of the surface layer to the total thickness of the laminate sheet is 1 to 20%.

[0012] [2] The laminate sheet of [1], wherein the styrene-based copolymer (S) is one or more styrene-based copolymers selected from the group consisting of acrylonitrile-styrene copolymers (AS), styrene-maleic anhydride copolymers (SMA), and styrene-maleic anhydride-methyl methacrylate copolymers (SMM).

[0013] [3] The laminate sheet according to [2], wherein the styrene-based copolymer (S) is one or more styrene-based copolymers selected from the group consisting of acrylonitrile-styrene copolymers (AS) containing 75 to 95 mass% of styrene units and styrene-maleic anhydride copolymers (SMA) containing 60 to 95 mass% of styrene units.

[0014] [4] The laminate sheet according to any one of [1] to [3], wherein the content of the styrene-based monomer unit in the laminate sheet is 0.1 to 25 mass %.

[0015] [5] The laminate sheet according to any one of [1] to [4], wherein the content of styrene-based monomer units in the base layer is 0.5 to 10.0 mass %.

[0016] [6] A laminate sheet according to any one of [1] to [5], wherein at least a portion of the raw materials of the base material layer is a recycled resin composition (R) consisting of pulverized material of the laminate sheet previously produced or a processed product of the pulverized material.

[0017] [7] The laminate sheet according to any one of [1] to [6], wherein the laminate sheet has a total thickness of 1 to 10 mm.

[0018] [8] A laminate sheet according to any one of [1] to [7], which is for inkjet printing and / or laser cutting.

[0019] [9] A laminate sheet of any of [1] to [8] which is a coextrusion molding sheet.

[0020]

[10] A printed matter, obtained by subjecting the surface layer of the laminate sheet according to any one of [1] to [9] to inkjet printing.

[0021]

[11] A molded product obtained by applying inkjet printing and laser cutting to any of the laminated sheets [1] to [9].

[0022]

[12] A method for producing a laminate sheet according to any one of [1] to [9], comprising co-extrusion molding the laminate sheet using a recycled resin composition (R) consisting of pulverized material of the laminate sheet previously produced or a processed product of the pulverized material, as at least a part of the total raw material of the base material layer. Effect of the Invention

[0023] According to the present disclosure, it is possible to provide a laminate sheet that has good ink adhesion and laser cutting processability and is highly sustainable. [Brief description of the drawings]

[0024] [Figure 1] 1 is a schematic cross-sectional view of a laminate sheet according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic cross-sectional view of a laminate sheet according to a second embodiment of the present invention. [Diagram 3] 1 is an electron microscope image showing the phase structure (completely compatible structure) of a base material layer contained in the laminate sheet obtained in Example (E2-3). [Figure 4]1 is an electron microscope image showing the phase structure (sea-island structure) of a base material layer contained in a laminate sheet obtained in Comparative Example (EC11-3). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] [Laminated sheet] The laminate sheet of the present disclosure has a base layer and a surface layer laminated on at least one side of the base layer. The base layer is made of a methacrylic resin composition (MR) containing a methacrylic resin (M) containing 80 to 100 mass% of methyl methacrylate (MMA) units and a styrene copolymer (S). The surface layer contains the styrene copolymer (S). The laminate sheet of the present disclosure is suitable for inkjet printing and / or laser cutting.

[0026] The laminate structure of the laminate sheet of the present disclosure may be a two-layer structure having a surface layer on one side of the base layer of the first embodiment shown in FIG. 1. In the figure, reference numeral 1 denotes the laminate sheet, reference numeral 11 denotes the base layer, and reference numeral 21 denotes the surface layer. The laminate sheet of the present disclosure may include any layer other than the base layer and the surface layer as necessary. However, the surface 21S of the surface layer 21 opposite the base layer does not have any other layer thereon and is an exposed surface. This exposed surface may be a printing surface on which printing is performed.

[0027] The laminated structure of the laminated sheet of the present disclosure may be a three-layer structure having surface layers on both sides of the base layer of the second embodiment shown in FIG. 2. In the figure, reference numeral 2 denotes a laminated sheet, reference numeral 11 denotes a base layer, reference numeral 22 denotes a first surface layer, and reference numeral 23 denotes a second surface layer. The second laminated sheet of the present disclosure may include any layer other than the base layer and the surface layer, as necessary. However, the surface 22S of the first surface layer 22 opposite the base layer and / or the surface 23S of the second surface layer 23 opposite the base layer have no other layer thereon and are exposed surfaces. This exposed surface may be a printing surface on which printing is applied. In a three-layer laminated sheet, the thickness and composition of the two surface layers may be the same or different.

[0028] The laminated sheet of the present disclosure is suitable as a resin sheet for inkjet printing. Examples of inkjet printing methods include an electrostatic suction method, a method in which a piezoelectric element such as a piezo element is used to apply mechanical vibration or displacement to ink, a method in which ink is heated to foam and the resulting pressure is utilized, and a method in which ultraviolet (UV) curable ink is used. The laminate sheet of the present disclosure can be inkjet printed on the surface layer. The laminate sheet of the present disclosure can also be cut using a laser, an NC router, or the like, as necessary, after inkjet printing, to form into a desired shape. The molded product thus obtained can be preferably used for miscellaneous goods and fixtures such as key holders. In such applications, a UV-curable ink or the like is preferably used as the inkjet printing ink.

[0029] Styrene-based copolymers (S) having an aromatic ring structure in the molecule generally have good permeability and good adhesion to inkjet printing inks such as UV-curable inks. However, styrene-based copolymers (S) having an aromatic ring structure do not have good laser cutting processability, and when the resin melts and evaporates due to laser light irradiation, the evaporated gas may give off an unpleasant odor or smoke. In addition, when the melted part cools and solidifies again after the laser cutting process is completed, the evaporated gas may adhere to the cut surface, causing a poor appearance of the cut surface. Methacrylic resins (M) generally suppress the above problems caused by evaporated gas (unpleasant odor or smoke caused by evaporated gas, and poor appearance of the cut surface caused by adhesion of evaporated gas) and have good laser cutting processability. However, they tend to have poor permeability for inkjet printing inks such as UV-curable inks, and poor adhesion for inkjet printing inks.

[0030] The laminate sheet of the present disclosure has a surface layer containing a styrene-based copolymer (S) having an aromatic ring structure in the molecule, and therefore has good permeability of inkjet printing inks such as UV-curable inks and good adhesion of inkjet printing inks. The laminate sheet of the present disclosure has a laminated structure of a base layer containing a methacrylic resin (M) and a surface layer containing a styrene copolymer (S), and the proportion of styrene monomer units in the entire laminate sheet is reduced, thereby suppressing the above-mentioned problems caused by evaporated gas during laser cutting (unpleasant odor or smoke caused by evaporated gas, and poor appearance of the cut surface caused by adhesion of evaporated gas) and improving laser cutting processability.

[0031] In the laminate sheet of the present disclosure, the ratio of the total thickness of the surface layer to the total thickness of the laminate sheet is 1 to 20%. The lower limit is preferably 2%, more preferably 3%. The upper limit is preferably 15%, more preferably 10%. When the ratio of the total thickness of the surface layer is equal to or greater than the above lower limit, the thickness of the surface layer containing the styrene copolymer (S) is sufficiently ensured, and good ink adhesion can be ensured. When the ratio of the total thickness of the surface layer is equal to or less than the above upper limit, the content of the styrene monomer unit in the laminate sheet can be reduced, and unpleasant odors or smoke due to evaporated gas during laser cutting and poor appearance of the cut surface due to adhesion of evaporated gas can be suppressed.

[0032] The content of the styrene monomer unit in the laminate sheet (also referred to as the average concentration of the styrene monomer unit in the laminate sheet) is not particularly limited, and is preferably 0.1 to 25% by mass. The lower limit is more preferably 0.5% by mass, even more preferably 1.0% by mass, even more preferably 2.0% by mass, particularly preferably 3.0% by mass, and most preferably 5.0% by mass. The upper limit is more preferably 22% by mass, even more preferably 20% by mass, even more preferably 17% by mass, particularly preferably 15% by mass, and most preferably 10% by mass. When the average concentration of the styrene monomer unit in the laminate sheet is equal to or higher than the lower limit, good ink adhesion can be ensured, and when it is equal to or lower than the upper limit, unpleasant odor or smoke due to evaporated gas during laser cutting and poor appearance of the cut surface due to adhesion of evaporated gas can be suppressed.

[0033] In the laminate sheet of the present disclosure, the total thickness of the laminate sheet is not particularly limited, and is preferably 1 to 10 mm, more preferably 1 to 5 mm, in order to improve inkjet printability and laser cutting processability. For example, when the total thickness of the laminate sheet is 3 mm, the thickness of the base layer is preferably 2.4 to 2.9 mm, the thickness of one surface layer is preferably 30 to 300 μm, and the total thickness of the surface layers is preferably 30 to 600 μm.

[0034] The laminated sheets of the present disclosure are preferably coextruded sheets. The haze value of the laminate sheet of the present disclosure is not particularly limited, and is preferably 5% or less, more preferably 4% or less, even more preferably 3% or less, particularly preferably 2% or less, and most preferably 1% or less. By using a specific styrene-based copolymer having good compatibility with the methacrylic resin (M) as the styrene-based copolymer (S) contained in the surface layer, it is possible to produce a laminate sheet of the present disclosure having a low haze value and excellent transparency, even if a recycled resin composition (R) consisting of ground material of a laminate sheet of the present disclosure produced in the past or a processed product of the ground material is used as at least a part of the total raw material of the base layer. In this specification, unless otherwise specified, "transparent" is defined as a haze value of 5% or less. The haze value can be measured by the method described in the "Examples" section below.

[0035] (Surface layer) The surface layer contains one or more styrene copolymers (S). Examples of the styrene monomer units contained in the styrene copolymers (S) include styrene, α-methylstyrene, o-, m- or p-methylstyrene, and combinations thereof, with styrene being preferred. As described above, in the present disclosure, the styrene copolymer (S) used has good compatibility with the methacrylic resin (M). From the viewpoint of compatibility with the methacrylic resin (M), the styrene copolymer (S) may be one or more styrene copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin), and methyl methacrylate-styrene copolymer (MS resin). Among the above, one or more styrene copolymers selected from the group consisting of acrylonitrile-styrene copolymers (AS resins), styrene-maleic anhydride copolymers (SMA resins), and styrene-maleic anhydride-methyl methacrylate copolymers (SMM resins) are preferred because of their excellent compatibility with the methacrylic resin (M).Acrylonitrile-styrene copolymers (AS resins), styrene-maleic anhydride copolymers (SMA resins), or combinations thereof are more preferred.

[0036] From the viewpoint of compatibility with the methacrylic resin (M), the content of styrene units in the acrylonitrile-styrene copolymer (AS resin) is preferably 75 to 95% by mass. The lower limit is more preferably 76% by mass, and particularly preferably 77% by mass. The upper limit is more preferably 90% by mass, even more preferably 88% by mass, particularly preferably 85% by mass, and most preferably 83% by mass. Commercially available AS resins include "Lithac-A 100PCF" and "120PCF" manufactured by Nippon A&L Co., Ltd., "Sunrex SAN-C", "SAN-R", and "SAN-H" manufactured by Techno UMG Co., Ltd., "Denka AS AS-C-800" and "AS-C-820" manufactured by Denka Co., Ltd., "Toyolac" manufactured by Toray Industries, Inc., and "Cevian N" manufactured by Daicel Miraize Co., Ltd. Among them, "Lithac-A 100PCF" manufactured by Nippon A&L Co., Ltd., "Sunrex SAN-C" manufactured by Techno UMG Co., Ltd., and "Denka AS AS-C-820" manufactured by Denka Co., Ltd. are preferred.

[0037] From the viewpoint of compatibility with the methacrylic resin (M), the content of styrene units in the styrene-maleic anhydride copolymer (SMA resin) is preferably 60 to 95% by mass. The lower limit is more preferably 70% by mass, and particularly preferably 75% by mass. The upper limit is more preferably 90% by mass, particularly preferably 85% by mass, and most preferably 80% by mass. Commercially available SMA resins include "XIRAN" and "XIBOND" manufactured by Polyscope; "SMA-700" manufactured by Jiaxing Huawen Chemical; and "SAM-020" manufactured by Fine-blend Polymer.

[0038] From the viewpoint of compatibility with the methacrylic resin (M), the content of styrene units in the styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin) is preferably 60 to 95% by mass. The lower limit is more preferably 70% by mass, and particularly preferably 75% by mass. The upper limit is more preferably 90% by mass, particularly preferably 85% by mass, and most preferably 80% by mass. Commercially available SMM resins include "Resify R-200" manufactured by Denka.

[0039] In the surface layer, the total amount of one or more styrene-based copolymers selected from the group consisting of acrylonitrile-styrene copolymers (AS resins), styrene-maleic anhydride copolymers (SMA resins), and styrene-maleic anhydride-methyl methacrylate copolymers (SMM resins) is preferably 51 to 100% by mass. The lower limit is more preferably 65% ​​by mass, particularly preferably 70% by mass, and most preferably 80% by mass.

[0040] Methyl methacrylate-styrene copolymer (MS resin) can be used in small amounts because it is compatible with the methacrylic resin (M). When using a methyl methacrylate-styrene copolymer (MS resin), it is preferable to use it in combination with a styrene copolymer that has excellent compatibility with the methacrylic resin (M), such as an acrylonitrile-styrene copolymer (AS resin), a styrene-maleic anhydride copolymer (SMA resin), or a styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin).

[0041] The amount of methyl methacrylate-styrene copolymer (MS resin) in the surface layer is preferably 0 to 1.5% by mass. The upper limit is more preferably 1.2% by mass, particularly preferably 1.0% by mass, and most preferably 0.85% by mass. From the viewpoint of compatibility with the methacrylic resin (M), the content of styrene units in the methyl methacrylate-styrene copolymer (MS resin) is preferably 35 to 50% by mass. The upper limit is more preferably 45% by mass. Commercially available MS resins include "TOYO MS MS600" manufactured by Toyo Styrene Co., Ltd.; "DENKA TX Polymer TX-100S" manufactured by Denka Co., Ltd.; and "Cevian NAS" manufactured by Daicel Miraize Co., Ltd.

[0042] Acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), and high impact polystyrene graft-copolymerized with butadiene (HIPS resin) are not preferably used as the styrene copolymer (S) because they are poorly compatible with the methacrylic resin (M).

[0043] Within the range where the laminate sheet of the present disclosure satisfies the characteristic that the haze value is 5% or less, the surface layer may contain one or more methacrylic resins (M) and / or one or more other acrylic resins (A) other than the methacrylic resin (M) as necessary. Examples of the optional other acrylic resins (A) are the same as those of the base layer. The methacrylic resin (M) in the surface layer may be the same or different from the methacrylic resin (M) in the base layer. The same applies to the optional other acrylic resins (A).

[0044] Within the range where the laminate sheet of the present disclosure has a haze value of 5% or less, the surface layer may contain one or more other polymers other than the styrene polymer (S), the methacrylic resin (M), and the other acrylic resin (A) as necessary. The other polymers are not particularly limited, and include other thermoplastic resins such as polyolefins such as polyethylene and polypropylene, polyamides, polyphenylene sulfide, polyether ether ketone, polyesters, polysulfones, polyphenylene oxides, polyimides, polyetherimides, and polyacetals; and thermosetting resins such as phenolic resins, melamine resins, silicone resins, and epoxy resins. The content of the other polymers in the surface layer is preferably 0 to 10% by mass. The upper limit is more preferably 5% by mass, and particularly preferably 2% by mass. The surface layer may not contain other polymers other than the styrene polymer (S), the methacrylic resin (M), and the other acrylic resin (A).

[0045] The surface layer may contain various additives as necessary within a range that satisfies the characteristic that the haze value of the laminated sheet of the present disclosure is 5% or less. Examples of additives include colorants, antioxidants, heat deterioration inhibitors, ultraviolet absorbers, light stabilizers, lubricants, release agents, polymer processing aids, antistatic agents, flame retardants, light diffusing agents, matting agents, rubber components (impact resistance modifiers) such as core-shell particles and block copolymers, and fluorescent materials. The content of the additives can be appropriately set within a range that does not impair the effects of the present invention. For example, the content of the antioxidant is preferably 0.01 to 1 part by mass, the content of the ultraviolet absorber is preferably 0.01 to 3 parts by mass, the content of the light stabilizer is preferably 0.01 to 3 parts by mass, and the content of the lubricant is preferably 0.01 to 3 parts by mass, relative to 100 parts by mass of the constituent resin of the surface layer (100 parts by mass in total in the case of multiple types). When other polymers and / or additives are added to the surface layer, the timing of addition may be during or after polymerization of the styrene-based copolymer (S).

[0046] The glass transition temperature (Tg) of the constituent resin of the surface layer (a mixed resin composition when multiple types are used) is not particularly limited, and is preferably 80 to 160°C, more preferably 100 to 110°C.

[0047] (base material layer) The substrate layer contains one or more methacrylic resins (M). The methacrylic resin (M) is a homopolymer or copolymer containing methyl methacrylate (MMA) units. From the viewpoint of transparency, the content of MMA units in the methacrylic resin (M) is 80 to 100% by mass. The lower limit is preferably 90% by mass, more preferably 95% by mass.

[0048] The methacrylic resin (M) may contain one or more (meth)acrylic acid ester units other than MMA units. Examples of (meth)acrylic acid esters other than MMA include methyl acrylate (MA), ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and the like. Examples of the acrylates include acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, trifluoromethyl (meth)acrylate, trifluoroethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, glycidyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, and 3-dimethylaminoethyl (meth)acrylate. Among these, MA is preferred from the viewpoint of transparency. For example, a copolymer of MMA and MA is preferred because it has excellent transparency. In this specification, (meth)acrylic is a general term for acrylic and methacrylic, and the same applies to (meth)acrylic acid, (meth)acrylonitrile, and the like.

[0049] The substrate layer may contain one or more other acrylic resins (A) other than the methacrylic resin (M) as necessary. In this specification, the "other acrylic resins (A)" refer to methacrylic resins having an MMA unit content of less than 80 mass% and (meth)acrylic resins that do not contain MMA units and contain one or more (meth)acrylic acid ester units other than MMA units.

[0050] The methacrylic resin (M) and the other acrylic resin (A) may contain structural units derived from one or more other monomers other than (meth)acrylic acid esters. Examples of the other monomers include (meth)acrylic acid, (meth)acrylic acid metal salts, (meth)acrylonitrile, (meth)acrylamide, vinyl monomers such as vinyl chloride and vinyl acetate, acid anhydrides such as maleic anhydride, maleimides such as phenylmaleimide and cyclohexylmaleimide, and styrene monomers such as styrene, α-methylstyrene, and vinyltoluene. The content (total amount when multiple types are present) of structural units derived from monomers other than (meth)acrylic acid esters in the methacrylic resin (M) and the other acrylic resin (A) is preferably 0 to 10 mass%, more preferably 5 mass%, particularly preferably 2 mass%. The content of styrene monomer units in the methacrylic resin (M) and the other acrylic resin (A) (when multiple types are present, the total amount) is preferably 0 to 1.5 mass%, and the upper limit is more preferably 1.2 mass%, particularly preferably 1.0 mass%, and most preferably 0.85 mass%. The methacrylic resin (M) and the other acrylic resin (A) may not contain a styrene monomer unit.

[0051] The methacrylic resin (M) and the other acrylic resin (A) are obtained by polymerizing one or more (meth)acrylic acid esters and, if necessary, other monomers. When using multiple types of monomers, the multiple types of monomers are usually mixed to prepare a monomer mixture, and then polymerization is performed. There are no particular limitations on the polymerization method, and from the viewpoint of productivity, radical polymerization methods such as bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization are preferred.

[0052] In the laminate sheet of the present disclosure, the substrate layer is made of a methacrylic resin composition (MR) containing a methacrylic resin (M) and a styrene copolymer (S). The styrene copolymer (S) in the substrate layer may be the same or different from the styrene copolymer (S) in the surface layer. When the base layer contains a styrene-based monomer unit, there is a tendency that the amount of change in warpage of the laminate sheet after being left standing in a high-humidity environment can be effectively reduced.

[0053] In general, in the production of (co)extrusion molded sheets and molded products using the same, there are defective products that arise when the extrusion molding production line is started up, scraps generated by trimming both ends of the sheet, defective products that are determined not to meet product standards in quality inspections for defects and foreign bodies, and scraps generated by cutting the sheet. In recent years, efforts toward a sustainable society have been progressing, and it is preferable to effectively reuse the above-mentioned defective products and scraps as rework materials rather than disposing of them. In this specification, a "virgin material" is a molding material that has never been subjected to molding processing in the past, and a "rework material" is a molding material that has been molded into a molded product at least once in the past. At least a part of the total raw material of the base material layer can be a recycled resin composition (R) (also called a rework material) made of crushed material of the laminated sheet of the present disclosure that was previously manufactured or a processed product of the crushed material. The form of the processed product can be strands, pellets, etc. As described above, the haze value of the laminate sheet of the present disclosure can be 5% or less, so a laminate sheet of the present disclosure having excellent transparency can be manufactured by using a recycled resin composition (R) consisting of pulverized material of a laminate sheet of the present disclosure previously manufactured or a processed product of the pulverized material as at least a part of the total raw material of the base layer.

[0054] The content of the styrene monomer unit in the base layer is not particularly limited, and is preferably 0.5 to 10.0% by mass. The lower limit is more preferably 0.7% by mass, particularly preferably 0.8% by mass, and most preferably 1.0% by mass. Patent Document 3, listed in the [Background Art] section, states that "in order to suppress the occurrence of cloudiness and maintain transparency, the styrene content in the base layer is preferably 1 mass % or less, and more preferably 0.85 mass % or less" (paragraph 0171). In the technology of the present disclosure, the content of the styrene-based monomer unit in the base layer can be made larger than the range described in Patent Document 3, and can be made 1.2 mass% or more, 1.5 mass% or more, 2.0 mass% or more, 2.5 mass% or more, 3.0 mass% or more, 3.5 mass% or more, or 4.0 mass% or more. The upper limit is more preferably 9.0 mass%, particularly preferably 8.5 mass%, and most preferably 8.0 mass%.

[0055] The styrene copolymer (S) contained in the base layer can have excellent compatibility with the methacrylic resin (M), so that the base layer has the following phase structure and can have excellent transparency. The base layer can have a completely compatible structure consisting of a homogeneous phase in which the styrene-based copolymer (S) and the methacrylic resin (M) are completely compatible with each other in an electron microscope image (preferably a transmission electron microscope image (TEM image)). Alternatively, the base layer may have a microphase separation structure (sea-island structure) in which a plurality of particulate island phases containing a styrene-based copolymer (S) are dispersed in a sea phase containing a methacrylic resin (M) in an electron microscope image (preferably a transmission electron microscope image (TEM image)), and the maximum diameter of the plurality of particulate island phases is more than 0 nm and not more than 50 nm. The island phase is also called a discontinuous phase or domain. The sea phase is also called a continuous phase or matrix. The island phase may contain a styrene-based copolymer (S) and a methacrylic resin (M). The maximum diameter of the plurality of particulate island phases in the phase structure of the base layer and the microphase-separated structure (sea-island structure) can be determined by observation with an electron microscope. A specific method for determining the maximum diameter will be described in the section [Examples] below. In this specification, unless otherwise specified, the diameter of any one non-circular island phase is the maximum diameter (also referred to as the longest diameter) of that island phase. The maximum diameter of multiple particulate island phases is the diameter of the largest island phase among 100 particulate island phases randomly selected. From the viewpoint of transparency, the maximum diameter of the plurality of particulate island phases is preferably small, and the upper limit is preferably 40 nm, more preferably 30 nm, further preferably 20 nm, further preferably 10 nm, and particularly preferably 5 nm. It is most preferable that the base layer has a completely compatible structure consisting of a homogeneous phase in which the styrene-based copolymer (S) and the methacrylic resin (M) are completely compatible with each other in an electron microscope image (preferably a transmission electron microscope image (TEM image)).

[0056] Within the range of the above phase structure, the base layer may contain one or more other polymers other than the methacrylic resin (M), the other acrylic resin (A), and the styrene polymer (S) as required. The base layer may contain various additives as required. Examples of the types of other polymers and additives and the preferred amounts of addition are the same as those of the surface layer.

[0057] The glass transition temperature (Tg) of the constituent resin of the substrate layer (a mixed resin composition when multiple resins are used) is not particularly limited and is preferably 100 to 140°C, more preferably 105 to 135°C, and particularly preferably 105 to 125°C.

[0058] [Manufacturing method of laminated sheet] The laminated sheet of the present disclosure can be manufactured by a known sheet molding method, and from the viewpoints of production efficiency and interlayer adhesion, an extrusion molding method, etc. is preferred. In the case of the extrusion molding method, a co-extrusion molding is preferred in which a base layer material containing a methacrylic resin composition (MR) and a surface layer material containing a styrene copolymer (S) melt-kneaded using different extruders are co-extruded from a common extrusion die (such as a T-die).

[0059] Co-extrusion die systems include a multi-manifold die system and a field block system. In the feed block system, a molten base layer material containing a methacrylic resin composition (MR) and a molten surface layer material containing a styrene copolymer (S) are laminated in a feed block, then guided to a T-die or the like to be formed into a sheet and co-extruded. In the multi-manifold die system, a molten base layer material containing a methacrylic resin composition (MR) and a molten surface layer material containing a styrene copolymer (S) are guided to a T-die or the like to be formed into a sheet, then guided to a T-die or the like to be formed into a sheet, then laminated and co-extruded. In the laminate sheet of the present disclosure, the surface layer is designed to be thin. In this case, the multi-manifold die system is preferred. In either method, the thermoplastic resin laminate extruded from a T-die or the like is cooled by passing through a gap between at least a pair of cooling pressure rolls, and then taken up by a take-up roll. The above co-extrusion, cooling, and take-up steps are carried out continuously. In this specification, the heated and molten state is mainly referred to as a "thermoplastic resin laminate" and the solidified state is referred to as a "laminate sheet", but there is no clear boundary between the two.

[0060] In the co-extrusion molding of the laminated sheet of the present disclosure, the T die temperature (Td) is preferably 190 to 280°C. If Td is less than 190°C, the melt viscosity of the methacrylic resin composition (MR) and the styrene copolymer (S) may become too high, and these resins may not be extruded satisfactorily. If Td is more than 280°C, the styrene copolymer (S) may decompose due to high temperature. Td is more preferably 210 to 270°C, particularly preferably 230 to 260°C. The lip thickness of the T-die is designed according to the desired total thickness of the laminate sheet (preferably 1 to 10 mm). The take-up speed (V) of the laminated sheet by the pair of take-up rolls is not particularly limited, and is preferably 0.5 to 2.0 m / min.

[0061] In the manufacturing method of the laminate sheet of the present disclosure, the laminate sheet of the present disclosure can be co-extrusion molded using a recycled resin composition (R) (rework material) consisting of pulverized material of a laminate sheet of the present disclosure previously manufactured or a processed product of the pulverized material, as at least a portion of the total raw material of the base layer. The proportion of the recycled resin composition (R) in the total raw materials of the base layer is not particularly limited and can be, for example, 1 to 100% by mass. In the technology of the present disclosure, the proportion of the recycled resin composition (R) in the total raw materials of the base layer can be increased, and can be 10 to 100% by mass, 20 to 100% by mass, 30 to 100% by mass, 40 to 100% by mass, or 50 to 100% by mass.

[0062] Generally, when the same material is repeatedly reworked, the quality of the rework material may deteriorate, and the haze value of the laminated sheet using the rework material may increase. Taking into consideration the number of reworks or the quality of the rework material, it is preferable to adjust the usage ratio of the rework material within a range that satisfies the characteristic that the haze value of the laminated sheet of the present disclosure is 5% or less. Even when at least a portion of the total raw materials of the base layer is a recycled resin composition (R) consisting of pulverized material of a laminate sheet of the present disclosure that was previously manufactured or a processed product of the pulverized material, the laminate sheet of the present disclosure has excellent transparency and a haze value of 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less.

[0063] [Printed materials, molded products] The laminate sheet of the present disclosure can be preferably used as a resin sheet for inkjet printing. A printed matter can be provided by performing inkjet printing on the surface layer containing the styrene copolymer (S) contained in the laminate sheet of the present disclosure. The laminate sheet of the present disclosure can also be cut using a laser and an NC router, etc., as necessary, after the inkjet printing, to form it into a desired shape. The laminated sheet of the present disclosure has good laser cutting processability, so that fine cutting can be performed. For example, a molded product having a curved cut portion with a radius of 0.5 to 2 mm can be manufactured with good shape accuracy. The laminated sheet of the present disclosure has good laser cutting processability, so that a high-power laser processing machine can be used to perform cutting at high speed with good productivity. For example, the laminated sheet of the present disclosure can be cut at a speed of 350 cm / min or more with a laser processing machine with an output of 100 W or more to manufacture a molded product.

[0064] As described above, according to the present disclosure, it is possible to provide a laminate sheet that has good ink adhesion and laser cutting processability, and is highly sustainable.

[0065] [Application] The laminated sheets, printed matter, and molded articles of the present disclosure can be used in a variety of fields, such as printing, advertising, sign and display, events, amusement, architecture, and interior design. The laminated sheet, printed matter, and molded article of the present disclosure can be preferably used for miscellaneous goods such as key holders, fixtures, and the like. EXAMPLES

[0066] Examples and comparative examples according to the present invention will be described below. [Evaluation items and evaluation methods] (Content of styrene units in styrene copolymer (S)) Using a nuclear magnetic resonance spectrometer (Bruker's "ULTRA SHIELD 400 PLUS"), the styrene copolymer (S) 1 H-NMR spectrum was measured. The styrene unit concentration was calculated from the integral value of the peaks derived from the hydrogen atoms bonded to the carbon atoms at positions 2 to 6 of the aromatic ring contained in styrene.

[0067] (Haze value of laminated sheet) A test piece of 50 mm x 50 mm was cut out from the center in the width direction of the laminated sheet obtained using the rework material, and the haze value was measured using "HM-150" manufactured by Murakami Color Research Laboratory.

[0068] (Phase structure of base layer) A test piece with a thickness of 70 nm was cut out from the base layer of the laminated sheet obtained using the rework material, and stained with phosphotungstic acid (PTA) as a staining agent. A field emission scanning electron microscope (FE-SEM) (JEOL "JSM-7600F") and its optional transmission electron detector were used to observe the transmission electron microscope image (TEM image) of the phase structure of the base layer, and evaluated according to the following criteria. When the styrene copolymer (S) and the methacrylic resin (M) were completely compatible with each other to form a homogeneous phase, the compatibility was judged to be good (A). When a microphase separation structure (sea-island structure) in which multiple particulate island phases containing a styrene copolymer (S) are dispersed in a sea phase containing a methacrylic resin (M) was confirmed, the largest island phase with the largest diameter was identified among 100 randomly selected particulate island phases, and the diameter of the largest island phase was determined as the "maximum diameter of multiple particulate island phases." When the maximum diameter of the multiple particulate island phases was greater than 0 nm and less than 50 nm, the compatibility was determined to be good (B), and when the maximum diameter of the multiple particulate island phases was greater than 50 nm, the compatibility was determined to be poor (C).

[0069] (Ink adhesion) The ink adhesion was evaluated for the inkjet-printed laminated sheet. In the printed layer consisting of the cured product of white and black UV-curable ink, a 10 mm square evaluation area was cross-cut into 100 squares (10 squares vertically x 10 squares horizontally) at 1 mm intervals vertically and horizontally. Cellophane tape was applied to the entire evaluation area, and the tape was rubbed with an eraser to ensure that the tape was sufficiently adhered to the printed surface, after which the tape was peeled off at a 90° angle. Observation was performed with a 10x magnifying glass, and the number of squares where the ink had peeled off from the laminated sheet was counted out of the 100 squares to be evaluated. The evaluation criteria are as follows: A (Excellent): No ink peeling was observed in any of the squares. B (Good): Ink peeling was observed in squares with 1 or more and less than 10. C (Acceptable): Ink peeling was observed in 10 or more but less than 50 squares. D (Fail): Ink peeling was observed in 50 or more squares.

[0070] (Laser cutting processability) The inkjet-printed laminated sheet was evaluated for laser cutting processability. <Appearance of cut surface> The ten molded products obtained after the laser cutting process were evaluated for defects on the cutting surface of the 30 cm straight cut section by optical microscope observation and finger touch inspection. The main defects are as follows: Roughness: The cutting surface was not uniform overall and felt rough to the touch. Rough corners: The corners of the cut surface were partially rough and felt rough to the touch. Resin pool: Molten resin pool was observed on some parts of the cutting surface. Foreign matter: Colored foreign matter was found on the cutting surface. The evaluation criteria are as follows: A (Excellent): The number of molded products with defects is 0 to 1. B (Good): The number of molded products with defects is 2 to 4. C (Fail): The number of molded products with defects is 5 to 10.

[0071] <Whether or not smoke or odor is generated> The presence or absence of smoke or odor generation during laser cutting was evaluated sensorily. The evaluation criteria are as follows: A (Good): There was some smoke or odor, but it was not noticeable. B(Acceptable): Between A and C. C (bad): There was noticeable smoke or odor.

[0072] [material] The materials used are as follows: (Methacrylic resin (M)) <pmma1>Methyl methacrylate-methyl acrylate copolymer, "Parepet" manufactured by Kuraray, methyl methacrylate unit content: 94 mass%, methyl acrylate unit content: 6 mass%, styrene unit content: 0 mass%.

[0073] (Acrylonitrile-styrene copolymer (AS resin)) <as1>Nippon A&L "Lytac-A 00PCF", styrene unit content: 77% by mass, <as2>Denka AS SC-820 manufactured by Denka Co., Ltd., styrene unit content: 82% by mass, <as3>Techno UMG's "Sunrex AN-C", styrene unit content: 76% by mass, <asc4>"Cevian-N 020SF" manufactured by Daicel Miraize Co., Ltd., styrene unit content: 74% by mass.

[0074] (SMA resin composition) <sma1> As a styrene-maleic anhydride copolymer (SMA resin), "XIRAN23110" (styrene unit content: 77% by mass) manufactured by Polyscope was prepared. This copolymer and a methacrylic resin (PMMA1) were melt-kneaded in a mass ratio of 1:1 to obtain an SMA resin composition (SMA1).

[0075] (Methyl methacrylate-styrene copolymer (MS resin)) <ms200>"Toyo MS MS200" manufactured by Toyo Styrene Co., Ltd., styrene unit content: 80 mass%.

[0076] [Laminated sheet manufacturing] (Reference Examples (E1-V) to (E3-V), (E5-V), Reference Comparative Examples (EC11-V), (EC13-V)) As the base layer material, virgin methacrylic resin (M) was melted using a 150 mmφ single screw extruder (maximum temperature of the cylinder part: 250°C) manufactured by Toshiba Machine Co., Ltd. As the surface layer material, virgin styrene copolymer (S) was melted using a 65 mmφ single screw extruder (maximum temperature of the cylinder part: 240°C) manufactured by Toshiba Machine Co., Ltd. Using a multi-manifold die, the molten styrene copolymer (S), the molten methacrylic resin (M), and the molten styrene copolymer (S) were laminated in this order, extruded from a T-die, cooled using four adjacent cooling rolls, and taken up by a take-up roll. By the above co-extrusion molding, two-kind three-layer laminate sheets (L1-V) to (L3-V), (L5-V), (LC11-V), and (LC13-V) of styrene copolymer (S) (first surface layer, 0.15 mm thick) / methacrylic resin (M) (base layer, 2.7 mm thick) / styrene copolymer (S) (second surface layer, 0.15 mm thick) were manufactured. The first surface layer and the second surface layer had the same composition and thickness. The main manufacturing conditions and various parameter values ​​are shown in Tables 1 and 2. In these tables, conditions not listed in the tables were common conditions.

[0077] (Reference Examples (E4-V), (E6-V)) Laminated sheets (L4-V) and (L6-V) were obtained in the same manner as in Reference Example (E1-V), except that the thickness of each surface layer was changed to 0.05 mm (Reference Example (E4-V)) or 0.3 mm (Reference Example (E6-V)). The main manufacturing conditions and various parameter values ​​are shown in Table 1.

[0078] (Reference comparative example (EC12-V)) A laminated sheet (LC12-V) was obtained in the same manner as in the reference comparative example (EC11-V), except that the thickness of each surface layer was changed to 0.05 mm and the total thickness was changed to 2.8 mm. The main manufacturing conditions and various parameter values ​​are shown in Table 2.

[0079] (Examples (E1-1) to (E1-3)) Laminated sheets (L1-1) to (L1-3) were obtained in the same manner as in Reference Example (E1-V), except that at least a part (30 mass%, 50 mass%, or 100 mass%) of the base layer material was replaced with the pulverized laminated sheet obtained in Reference Example (E1-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 3. The virgin methacrylic resin (M) and the rework material were mixed by dry blending. The same applies to the other examples.

[0080] (Examples (E2-1) to (E2-3)) Laminated sheets (L2-1) to (L2-3) were obtained in the same manner as in Reference Example (E2-V), except that at least a part (30 mass%, 50 mass%, or 100 mass%) of the base layer material was replaced with the pulverized laminated sheet obtained in Reference Example (E2-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 3.

[0081] (Examples (E3-1) to (E3-3)) Laminated sheets (L3-1) to (L3-3) were obtained in the same manner as in Reference Example (E3-V), except that at least a part (30 mass%, 50 mass%, or 100 mass%) of the base layer material was replaced with the pulverized laminated sheet obtained in Reference Example (E3-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 3.

[0082] (Examples (E4-1) to (E4-3)) Laminated sheets (L4-1) to (L4-3) were obtained in the same manner as in Reference Example (E4-V), except that at least a portion (30 mass%, 50 mass%, or 100 mass%) of the base layer material was replaced with the pulverized laminated sheet obtained in Reference Example (E4-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 4.

[0083] (Examples (E5-1) to (E5-3)) Laminated sheets (L5-1) to (L5-3) were obtained in the same manner as in Reference Example (E5-V), except that at least a portion (30 mass%, 50 mass%, or 100 mass%) of the base layer material was replaced with the pulverized laminated sheet obtained in Reference Example (E5-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 4.

[0084] (Examples (E6-1) and (E6-2)) A laminate sheet was obtained in the same manner as in Example (E6-V), except that a part of the base layer material (30% by mass or 40% by mass) was replaced with the pulverized laminate sheet obtained in Example (E6-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 4.

[0085] (Comparative examples (EC11-1)~(EC11-3), (EC12-1), (EC13-1)) Laminated sheets (LC11-1) to (LC11-3), (LC12-1), and (LC13-1) were obtained in the same manner as in the reference comparative examples (EC11-V), (EC12-V), and (EC13-V), except that at least a portion (30 mass%, 50 mass%, or 100 mass%) of the base layer material was replaced with the pulverized laminated sheet obtained in the reference comparative examples (EC11-V), (EC12-V), and (EC13-V) as a rework material. The main manufacturing conditions and various parameter values ​​are shown in Table 5.

[0086] [Inkjet printing] Inkjet printing was carried out on one surface of the laminate sheet obtained in each example under the following conditions, and the above-mentioned ink adhesion was evaluated. The printing pattern was a solid print of an approximately ellipse with a minor axis of 1.8 cm and a major axis of 2.8 cm. Equipment: Roland DG "LEF-300" Temperature: room temperature (20~25℃), UV-curable ink (white): Roland DG EUV-BK, UV curable ink (black): Roland DG EUV-WH.

[0087] [Laser cutting] The laminated sheet after the inkjet printing was subjected to laser cutting under the following conditions to obtain a molded product in the shape of a TV anime character with dimensions of 20 mm in minor axis x 30 mm in major axis and a curved cut portion with a radius of 1 mm. Equipment: SEI "MERCURY609" Temperature: room temperature (20~30℃), Laser type: Carbon dioxide laser, Laser power: 200W, Cutting speed: 350~400cm / min.

[0088] [Evaluation Results] The evaluation results are shown in Tables 1 to 5.

[0089] [Table 1]

[0090] [Table 2]

[0091] [Table 3]

[0092] [Table 4]

[0093] [Table 5]

[0094] In the reference examples (E1-V) to (E6-V), only virgin materials were used as the materials for the base layer and the surface layer. In these examples, an acrylonitrile-styrene copolymer (AS resin) containing 75 to 95% by mass of styrene units, or a styrene-maleic anhydride copolymer (SMA resin) containing 60 to 95% by mass of styrene units was used as the styrene copolymer (S). In these examples, a base layer containing a methacrylic resin (M) and a surface layer containing a styrene copolymer (S) were laminated on both sides of the base layer, and a laminate sheet was produced in which the ratio of the total thickness of the surface layer to the total thickness of the laminate sheet was 1 to 20%. All of the obtained laminate sheets had good ink adhesion and laser cutting processability. The styrene copolymer (S) used in these examples had good compatibility with the methacrylic resin (M), and the haze value of the 3.0 mm-thick single-layer molded sheet that was the pulverized product of the obtained laminate sheet was 1% or less, and the transparency was good. In these examples, a laminate sheet with excellent sustainability that can be used as a rework material was obtained.

[0095] In Examples (E1-1) to (E1-3), laminate sheets were obtained in the same manner as in Reference Example (E1-V), except that 30 to 100% by mass of the total raw material of the base layer was replaced with a rework material made of the pulverized laminate sheet obtained in Reference Example (E1-V). All of the obtained laminate sheets had good ink adhesion and laser cutting processability. The laminated sheets obtained in these examples all had a haze value of 1% or less and good transparency. Even when a large amount of rework material was used, a high-quality laminated sheet was obtained, similar to the reference example using only virgin material. In these examples, a laminated sheet with excellent sustainability, including rework material, was obtained. Similar results were obtained in Examples (E2-1) to (E2-3), (E3-1) to (E3-3), (E4-1) to (E4-3), (E5-1) to (E5-3), (E6-1), and (E6-2).

[0096] All of the styrene copolymers (S) used in the examples shown in Tables 3 and 4 had good compatibility with the methacrylic resin (M). Therefore, the base layer of each of the laminated sheets obtained in these examples was completely compatible with the styrene copolymer (S) and the methacrylic resin (M). An example of an electron microscope image of complete compatibility is shown in Figure 3. Figure 3 is a transmission electron microscope image (TEM image) showing the phase structure (completely compatible structure) of the base layer contained in the laminated sheet obtained in Example (E2-3).

[0097] In Comparative Examples (EC11-1) to (EC11-3), (EC12-1), and (EC13-1), laminate sheets were obtained in the same manner as in Reference Comparative Example (EC11-V), (EC12-V), or (EC13-V), except that 30 to 100 mass% of the total raw materials of the base layer were replaced with a rework material consisting of a pulverized product of the laminate sheet obtained in Reference Comparative Example (EC11-V), (EC12-V), or (EC13-V). The laminate sheets obtained in these comparative examples all had a haze value significantly exceeding 5%, and the transparency was extremely poor. In these examples, even if the rework material was included, a laminate sheet having excellent transparency and excellent sustainability was not obtained.

[0098] The styrene copolymers (S) used in these comparative examples all had poor compatibility with the methacrylic resin (M). Therefore, the base layers of the laminated sheets obtained in these comparative examples all had a sea-island structure in which a plurality of particulate island phases containing the styrene copolymer (S) and the methacrylic resin (M) were dispersed in a sea phase containing the methacrylic resin (M), and the maximum diameter of the plurality of particulate island phases exceeded 50 nm, resulting in a poor phase structure. An example of an electron microscope image of an island-in-sea structure in which the maximum diameter of multiple particulate island phases exceeds 50 nm is shown in Figure 4. Figure 4 is a transmission electron microscope image (TEM image) showing the phase structure (island-in-sea structure) of the base material layer contained in the laminate sheet obtained in Comparative Example (EC11-3). Each island phase in this TEM image contained acrylonitrile-styrene copolymer (ASC4) and a small amount of methacrylic resin (PMMA1) that was dissolved therein.

[0099] The present invention is not limited to the above-described embodiment and examples, and appropriate design changes are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0100] 1, 2 Laminated sheet 11 Base material layer 21, 22, 23 surface layer

Claims

1. A laminated sheet having a base layer and a surface layer laminated on at least one surface of the base layer, The surface layer contains a styrene-based copolymer (S), the base layer is made of a methacrylic resin composition (MR) containing a methacrylic resin (M) containing 80 to 100% by mass of methyl methacrylate units and a styrene copolymer (S); the base layer has a completely compatible structure of the styrene-based copolymer (S) and the methacrylic resin (M), or a sea-island structure in which a plurality of particulate island phases containing the styrene-based copolymer (S) are dispersed in a sea phase containing the methacrylic resin (M), and the maximum diameter of the plurality of particulate island phases is more than 0 nm and not more than 50 nm; A laminate sheet, wherein the ratio of the total thickness of the surface layer to the total thickness of the laminate sheet is 1 to 20%.

2. The laminate sheet according to claim 1, wherein the styrene-based copolymer (S) is one or more styrene-based copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS), styrene-maleic anhydride copolymer (SMA), and styrene-maleic anhydride-methyl methacrylate copolymer (SMM).

3. The styrene copolymer (S) is one or more styrene copolymers selected from the group consisting of acrylonitrile-styrene copolymers (AS) containing 75 to 95% by mass of styrene units and styrene-maleic anhydride copolymers (SMA) containing 60 to 95% by mass of styrene units. The laminate sheet according to claim 2.

4. 2. The laminate sheet according to claim 1, wherein the content of the styrene-based monomer unit in the laminate sheet is 0.1 to 25% by mass.

5. 2. The laminate sheet according to claim 1, wherein the content of the styrene-based monomer unit in the base layer is 0.5 to 10.0% by mass.

6. The laminate sheet according to claim 1, wherein at least a portion of the total raw materials of the base layer is a recycled resin composition (R) consisting of crushed material of the laminate sheet produced in the past or a processed product of the crushed material.

7. The laminate sheet according to claim 1, wherein the total thickness of the laminate sheet is 1 to 10 mm.

8. 2. The laminate sheet according to claim 1, which is adapted for inkjet printing and / or laser cutting.

9. The laminate sheet of claim 1 which is a coextruded sheet.

10. A printed matter, obtained by inkjet printing on the surface layer of the laminate sheet according to claim 1.

11. A molded article obtained by subjecting the laminate sheet according to claim 1 to inkjet printing and laser cutting.

12. 2. The method for producing a laminate sheet according to claim 1, wherein the laminate sheet is co-extruded using a recycled resin composition (R) consisting of crushed material of the laminate sheet produced in the past or a processed product of the crushed material as at least a part of the total raw material of the base layer.

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