Laminated sheet, method for producing same, printed matter, and molded article

Abstract

Provided is a laminated sheet having good ink adhesion and laser cutting workability and excellent sustainability. This laminate sheet (1) has a base layer (11) and a surface layer (21) laminated on at least one surface of the base layer (11), the base layer (11) contains a methacrylic resin (M) containing 80-100 mass% of methyl methacrylate units, the surface layer (21) contains a styrene copolymer (S), and the ratio of the total thickness of the surface layer (21) to the total thickness of the laminate sheet (1) is 1-20%. The haze value of a single-layer molded sheet having a thickness of 3.0 mm of the crushed product of the laminated sheet (1) is 4% or less.

Description

Technical Field

[0001] The present invention relates to a laminated sheet, a method for manufacturing the same, a printed matter, and a molded article. Background Art

[0002] In inkjet printing in which digital images can be processed by a computer and recorded on a printing medium, the types of media that can be printed are also increasing, and the range of use is expanding. For example, it is widely used in various fields such as printing, advertising, sign displays, events, entertainment, architecture, and interior decoration. As a printing medium other than paper, a resin sheet can be cited. Unlike paper, the resin sheet has excellent water resistance and durability and can also be made transparent.

[0003] After inkjet printing is performed on the resin sheet for inkjet printing, cutting is performed using a laser, a numerically controlled router (NCRouter), etc. as needed, and it can be formed into a desired shape. The molded article thus obtained can be preferably used for miscellaneous goods such as keychains and daily utensils. It should be noted that a method for cutting a resin sheet using a laser has been disclosed, for example, in claim 1 of Patent Document 1.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-055348

[0007] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2018-94843

[0008] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2021-160119 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] In applications such as keychains and daily utensils, as a base resin of the resin sheet for inkjet printing, a methacrylic resin is preferably used from the viewpoints of transparency and ink color development. As the ink for inkjet printing, an ultraviolet (UV) curable ink or the like is preferably used. However, with respect to the methacrylic resin, there is a tendency that the adhesion of an ink for inkjet printing such as a UV curable ink is not very good. As a component having good adhesion of an ink for inkjet printing such as a UV curable ink, a styrene copolymer can be cited.

[0011] Generally, in laser cutting, depending on the material of the workpiece, sometimes unpleasant odors or fumes are generated due to the evaporation gas produced when the workpiece is melted and evaporated by laser irradiation. In addition, there is the following situation: after the laser cutting is completed, when the molten part cools and solidifies again, the evaporation gas adheres to the cutting surface, resulting in poor appearance of the cutting surface. Methacrylic resins are less likely to cause the above problems caused by evaporation gas (unpleasant odors or fumes caused by evaporation gas, and poor appearance of the cutting surface caused by the adhesion of evaporation gas), and tend to have good laser cuttability. In contrast, styrene copolymers having an aromatic ring structure in the molecule are likely to cause the above problems caused by evaporation gas (unpleasant odors or fumes caused by evaporation gas, and poor appearance of the cutting surface caused by the adhesion of evaporation gas), and tend to have poor laser cuttability.

[0012] Patent Documents 2 and 3 disclose a laminated sheet having good ink adhesion and laser cuttability, which has a base material layer containing a methacrylic resin and a surface layer containing a styrene copolymer such as methyl methacrylate-styrene copolymer (MS resin) (Claim 1 of Patent Document 2, Claim 1 of Patent Document 3). This laminated sheet can preferably be manufactured by coextrusion molding.

[0013] Generally, in the manufacture of (co)extruded sheets and molded articles using the (co)extruded sheets, there are defective products generated at the start-up of the extrusion production line, scraps generated by trimming the both ends of the sheet, defective products judged not to meet the product standards in quality inspections such as defects and foreign matters, and scraps generated by cutting the sheet. In recent years, efforts towards a sustainable society have been promoted, and it is preferable to reuse the above defective products and scraps as recycled materials without discarding them for effective utilization.

[0014] In the laminated sheets disclosed in Patent Documents 2 and 3, it is considered to use a previously manufactured laminated sheet containing a methacrylic resin and a styrene copolymer such as MS resin as a recycled material for the base material layer material. However, generally, the compatibility between styrene copolymers such as MS resin and methacrylic resins is poor, and there is a refractive index difference between these resins. Therefore, the laminated sheet using the above recycled material as the base material layer material may have reduced transparency and become cloudy. In fact, Patent Document 3 states that "in order to suppress cloudiness and maintain transparency, the styrene content in the base material layer is preferably 1% by mass or less, more preferably 0.85% by mass or less." (Paragraph 0171). In Patent Document 3, the preferred styrene content in the base material layer is very small. In addition, this document does not disclose an example of using a previously manufactured laminated sheet containing a methacrylic resin and a styrene copolymer such as MS resin as a recycled material. As the base material layer material, it is preferable to be able to use more recycled materials.

[0015] The present invention has been completed in view of the above problems, and an object thereof is to provide a laminated sheet having good ink adhesion, good laser cutting processability, and excellent sustainability.

[0016] Method for solving the problem

[0017] The present invention provides the following laminated sheets [1] to

[15] , a method for manufacturing the same, a printed matter, and a molded article.

[0018] [1] A laminated sheet having a base material layer and a surface layer laminated on at least one surface of the base material layer, wherein

[0019] the above-mentioned base material layer contains a methacrylic resin (M) containing 80 to 100% by mass of methyl methacrylate units,

[0020] the above-mentioned surface layer contains a styrene copolymer (S),

[0021] the ratio of the total thickness of the above-mentioned surface layer to the total thickness of the above-mentioned laminated sheet is 1 to 20%,

[0022] the haze value of a 3.0 mm thick single-layer molded sheet of the pulverized product of the above-mentioned laminated sheet is 4% or less.

[0023] [2] The laminated sheet according to [1], wherein the styrene copolymer (S) is one or more styrene copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS), styrene-maleic anhydride copolymer (SMA), and styrene-maleic anhydride-methyl methacrylate copolymer (SMM).

[0024] [3] The laminated sheet according to [1] or [2], wherein the content of styrene monomer units in the above-mentioned laminated sheet is 0.1 to 25% by mass.

[0025] [4] The laminated sheet according to any one of [1] to [3], wherein

[0026] the styrene copolymer (S) contains a styrene copolymer (SX), and the styrene copolymer (SX) is a binary copolymer of styrene monomer units (S) and other monomer units (X),

[0027] For the styrene copolymer (SX), measured under the condition that the measurement mode is the gated decoupling method 13When determining the ratios of the triad sequences (SSS) of styrenic monomer units (S)-styrenic monomer units (S)-styrenic monomer units (S), the triad sequences (XSS) of other monomer units (X)-styrenic monomer units (S)-styrenic monomer units (S), and the triad sequences (XSX) of other monomer units (X)-styrenic monomer units (S)-other monomer units (X) from the ¹³C-NMR spectra, the ratio of the triad sequence (SSS) is 0 to 40 mol%, and the ratio of the triad sequence (XSX) is 5 to 34 mol% with respect to a total of 100 mol% of the triad sequences (SSS), (XSS), and (XSX).

[0028] [5] The laminated sheet according to any one of [1] to [4], wherein

[0029] The styrenic copolymer (S) contains an acrylonitrile-styrene copolymer (AS-E). When gradient high performance liquid chromatography analysis is performed using two liquids, n-hexane and chloroform, as eluents under the following conditions, the ratio of the copolymer having a composition with an elution time of 9 minutes or less is 0 to 5% by mass, the ratio of the copolymer having a composition with an elution time of 23 minutes or more is 0 to 5% by mass, and the elution time at the peak top of the maximum peak in the chromatogram is 9 to 23 minutes.

[0030] <Conditions for gradient high performance liquid chromatography analysis>

[0031] As the column, a silica gel column with an inner diameter of 4.6 mmφ and a length of 25 cm, packed with spherical fully porous silica gel having a particle size of 5 μm, is used. The column temperature is set at 40°C. Using chloroform as the solvent, a sample solution with a concentration of 0.5 mg / mL is prepared.

[0032] When the time from the start of analysis is set as T (minutes), the gradient curve of the mobile phase is as follows.

[0033] The above mobile phase from T = 0 to T = 5 is a n-hexane / chloroform mixed solution (50 vol% / 50 vol%).

[0034] From T = 5 to T = 20, the chloroform concentration in the above mobile phase is increased from 50 vol% to 100 vol% at a constant rate.

[0035] The above mobile phase from T = 20 to T = 25 is 100 vol% chloroform.

[0036] The flow rate of the above mobile phase is 0.8 mL / minute.

[0037] As the detector, an absorbance detector with a detection wavelength of 260 nm is used.

[0038] [6] The laminated sheet according to any one of [1] to [5], wherein the base material layer contains a methacrylic resin composition (MR) containing a methacrylic resin (M) and a styrene copolymer (S).

[0039] [7] The laminated sheet according to [6], wherein the base material layer has a completely compatible structure of the styrene copolymer (S) and the methacrylic resin (M), or has 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 greater than 0 nm and 50 nm or less.

[0040] [8] The laminated sheet according to [6], wherein the content of the styrene monomer units in the base material layer is 0.5 to 10.0% by mass.

[0041] [9] The laminated sheet according to [6], wherein at least a part of all the raw materials of the base material layer is a recycled resin composition (R) composed of a pulverized product of the above-mentioned laminated sheet manufactured in the past or a processed product of the pulverized product.

[0042]

[10] The laminated sheet according to any one of [1] to [9], wherein the total thickness of the laminated sheet is 1 to 10 mm.

[0043]

[11] The laminated sheet according to any one of [1] to

[10] , which is used for inkjet printing and / or laser cutting processing.

[0044]

[12] The laminated sheet according to any one of [1] to

[11] , which is a co-extrusion molded sheet.

[0045]

[13] A printed matter obtained by inkjet printing the surface layer of the laminated sheet according to any one of [1] to

[12] .

[0046]

[14] A molded article obtained by inkjet printing and laser cutting processing the laminated sheet according to any one of [1] to

[12] .

[0047]

[15] A method for manufacturing the laminated sheet of [6], wherein a recycled resin composition (R) composed of a pulverized product of the above-mentioned laminated sheet manufactured in the past or a processed product of the pulverized product is used as at least a part of all the raw materials of the base material layer, and the laminated sheet is co-extrusion molded.

[0048] Advantages of the Invention

[0049] According to the present invention, it is possible to provide a laminated sheet having good ink adhesion and laser cutting processability and excellent sustainability. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic cross-sectional view of a laminated sheet according to an embodiment of the present invention.

[0051] Figure 2 is an example of a 13 C-NMR spectrum of a styrene copolymer (SX) measured under the condition that the measurement mode is the inverse gated decoupling method.

[0052] Figure 3 is an example of a chromatogram of an acrylonitrile-styrene copolymer (AS) obtained by gradient high performance liquid chromatography (gradient HPLC) analysis.

[0053] Figure 4 is an example of an electron microscope image showing the phase structure (sea-island structure) of the base material layer contained in the laminated sheet obtained in the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0054] [Laminated Sheet]

[0055] The laminated sheet of the present invention has a base material layer and a surface layer laminated on at least one surface of the base material layer. The base material layer contains a methacrylic resin (M) containing 80 to 100% by mass of methyl methacrylate (MMA) units, and the surface layer contains a styrene copolymer (S). The laminated sheet of the present invention is suitable for inkjet printing and / or laser cutting processing, etc.

[0056] As the laminated structure of the laminated sheet of the present invention, a two-layer structure having a surface layer on one surface of the base material layer can be cited.

[0057] As the laminated structure of the laminated sheet of the present invention, Figure 1 a three-layer structure having surface layers on both surfaces of the base material layer as shown in an embodiment can be cited. In the figure, reference numeral 1 is the laminated sheet, reference numeral 11 is the base material layer, reference numeral 21 is the first surface layer, and reference numeral 22 is the second surface layer. The laminated sheet 1 may contain other optional layers in addition to the base material layer and the surface layer as needed. However, the surface 21S on the side opposite to the base material layer of the first surface layer 21 and / or the surface 22S on the side opposite to the base material layer of the second surface layer 22 are exposed surfaces, and no other layers are provided thereon. This exposed surface can be a printing surface for performing printing. In the laminated sheet having a three-layer structure, the thicknesses and compositions of the two surface layers can be the same or different.

[0058] The laminated sheet of the present invention is suitable as a resin sheet for inkjet printing. As the inkjet printing method, the following can be cited: an electrostatic attraction method, a method of imparting mechanical vibration or displacement to the ink using a piezoelectric element such as a piezoelectric element, a method of heating the ink to cause foaming and using its pressure, and a method of using an ultraviolet (UV) curable ink, etc.

[0059] The laminated sheet of the present invention can be subjected to inkjet printing on the surface layer. The laminated sheet of the present invention can also be machined by cutting using a laser and a numerically controlled engraving machine, etc. as needed after the inkjet printing to be formed into a desired shape. The formed article thus obtained can be preferably used for miscellaneous goods such as keychains and daily utensils, etc. In this application, as the ink for inkjet printing, a UV curable ink, etc. is preferably used.

[0060] Regarding the styrene copolymer (S) having an aromatic ring structure in the molecule, generally, the ink for inkjet printing such as a UV curable ink has good permeability and good adhesion of the ink for inkjet printing. However, the laser machinability of the styrene copolymer (S) having an aromatic ring structure in the molecule is not so good, and sometimes an unpleasant odor or smoking caused by evaporation gas is generated when the resin is melted and evaporated by laser irradiation. In addition, there is a case where after the laser machining is completed, when the molten portion cools and is solidified again, the evaporation gas adheres to the machined surface, resulting in poor appearance of the machined surface.

[0061] The methacrylic resin (M) can generally suppress the above problems caused by evaporation gas (unpleasant odor or smoking caused by evaporation gas and poor appearance of the machined surface caused by the adhesion of evaporation gas), and has good laser machinability. However, there is a tendency that the ink for inkjet printing such as a UV curable ink has poor permeability and poor adhesion of the ink for inkjet printing.

[0062] Since the laminated sheet of the present invention has a surface layer containing the styrene copolymer (S) having an aromatic ring structure in the molecule, the ink for inkjet printing such as a UV curable ink has good permeability and good adhesion of the ink for inkjet printing.

[0063] The laminated sheet of the present invention has a laminated structure of a base material layer containing the methacrylic resin (M) and a surface layer containing the styrene copolymer (S), and the proportion of the styrene monomer unit in the whole laminated sheet is reduced. Therefore, the above problems caused by evaporation gas during laser machining (unpleasant odor or smoking caused by evaporation gas and poor appearance of the machined surface caused by the adhesion of evaporation gas) can be suppressed, and the laser machinability is good.

[0064] In the laminate of the present invention, the ratio of the total thickness of the surface layer to the total thickness of the laminate 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 at least the above lower limit, the thickness of the surface layer containing the styrene copolymer (S) can be sufficiently ensured, and good ink adhesion can be ensured. In addition, when the ratio of the total thickness of the surface layer is at most the above upper limit, the content of styrene monomer units in the laminate can be reduced, and the odor or smoke caused by the evaporation gas during laser cutting and the appearance defect of the cutting surface caused by the adhesion of the evaporation gas can be suppressed.

[0065] The content of styrene monomer units in the laminate is the ratio of the total mass of styrene monomer units in the laminate to the total mass of the laminate, and is also referred to as "the average concentration of styrene monomer units in the laminate" or "the average styrene monomer unit concentration in the whole laminate". The average styrene monomer unit concentration is not particularly limited, and is preferably 0.1 to 25% by mass. The lower limit is more preferably 0.5% by mass, further preferably 1.0% by mass, further 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, further preferably 20% by mass, further preferably 17% by mass, particularly preferably 15% by mass, and most preferably 10% by mass. Regarding the average concentration of styrene monomer units in the laminate, when it is at least the above lower limit, good ink adhesion can be ensured, and when it is at most the above upper limit, the odor or smoke caused by the evaporation gas during laser cutting and the appearance defect of the cutting surface caused by the adhesion of the evaporation gas can be suppressed.

[0066] In the laminate of the present invention, the total thickness of the laminate is not particularly limited, and from the viewpoint of good inkjet printability and laser cutting processability, it is preferably 1 to 10 mm, more preferably 1 to 5 mm. For example, when the total thickness of the laminate is 3 mm, the thickness of the base material 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 layer is preferably 30 to 600 μm.

[0067] Regarding the laminated sheet of the present invention, the haze value of a 3.0 mm thick single-layer formed sheet of the pulverized product of the laminated sheet of the present invention is 4% or less, preferably 3% or less, more preferably 2% or less, and particularly preferably 1% or less. As the styrene copolymer (S) contained in the surface layer, by using a styrene copolymer having good compatibility with the methacrylic resin (M), the haze value of the above single-layer formed sheet can be achieved. When the haze value of the above single-layer formed sheet is 4% or less, by using the recycled resin composition (R) composed of the pulverized product of the laminated sheet of the present invention manufactured in the past or a processed product of the pulverized product as at least a part of all the raw materials of the base material layer, a laminated sheet of the present invention with excellent transparency can be manufactured. The laminated sheet of the present invention having the above characteristics can be used as a recycled material or can contain a recycled material, and has excellent sustainability.

[0068] In this specification, unless otherwise specified, "transparent" is defined as having a haze value of 4% or less.

[0069] The 3.0 mm thick single-layer formed sheet of the pulverized product of the laminated sheet of the present invention can be obtained by a known method. For example, it can be obtained as follows.

[0070] Using a known resin pulverizing mill, the laminated sheet of the present invention is pulverized. The obtained pulverized product is melt-kneaded using an extruder and a kneading / extrusion test device (such as "Labo Plastomill (registered trademark)" manufactured by Toyo Seiki Co., Ltd.) to form a uniform resin composition. The obtained melt-kneaded product is formed by a known method such as hot pressing to obtain a 3.0 mm thick single-layer formed sheet.

[0071] The melt-kneading temperature and the forming temperature during the forming of the single-layer formed sheet are preferably within the range of the appropriate melt-kneading temperature of the base material layer material during the forming (preferably co-extrusion forming) of the laminated sheet of the present invention. For example, it can be the highest temperature in the extruder used in the melt-kneading of the base material layer material during the forming (preferably co-extrusion forming) of the laminated sheet of the present invention. The melt-kneading temperature and the forming temperature during the forming of the single-layer formed sheet are preferably 190 to 280 °C, more preferably 210 to 270 °C, particularly preferably 230 to 260 °C, and for example, preferably 250 °C.

[0072] For specific examples of the forming method of the single-layer formed sheet and the measuring method of its haze value, please refer to the [Examples] section described later.

[0073] The laminated sheet of the present invention is preferably a co-extrusion formed sheet.

[0074] The haze value of the laminated sheet of the present invention is not particularly limited, and is preferably 4% or less, more preferably 3% or less, particularly preferably 2% or less, and most preferably 1% or less.

[0075] As the styrenic copolymer (S) contained in the surface layer, by using a specific styrenic copolymer having good compatibility with the methacrylic resin (M), even if a recycled resin composition (R) composed of the pulverized product of the laminated sheet of the present invention manufactured in the past or a processed product of the pulverized product is used as at least a part of all the raw materials of the base material layer, it is possible to manufacture the laminated sheet of the present invention having a low haze value and excellent transparency.

[0076] (Surface layer)

[0077] The surface layer contains one or more styrenic copolymers (S). As the styrenic monomer units contained in the styrenic copolymer (S), styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene or p-methylstyrene, and combinations thereof, etc. can be cited, and styrene etc. are preferred.

[0078] As described above, in the present invention, as the styrenic copolymer (S), a styrenic copolymer having good compatibility with the methacrylic resin (M) is used. From the viewpoint of compatibility with the methacrylic resin (M), as the styrenic copolymer (S), one or more styrenic 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-styrenic copolymer (MS resin) can be cited.

[0079] Among the above, from the aspect of excellent compatibility with the methacrylic resin (M), one or more styrenic copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin) and styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin) are preferred. More preferably, acrylonitrile-styrenic copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin) or a combination thereof.

[0080] From the viewpoint of compatibility with the methacrylic resin (M), the content of the styrene unit in the acrylonitrile-styrenic copolymer (AS resin) is preferably 75 to 95% by mass. The lower limit value is more preferably 76% by mass, particularly preferably 77% by mass. The upper limit value is more preferably 90% by mass, further preferably 88% by mass, particularly preferably 85% by mass, and most preferably 83% by mass.

[0081] Examples of commercially available AS resins include "LITAC-A 100PCF" and "120PCF" manufactured by Japan A&L Corporation; "SANREX SAN-C", "SAN-R", and "SAN-H" manufactured by Techno UMG Corporation; "Denka AS AS-C-800" and "AS-C-820" manufactured by Denka Company; "Toyolac" manufactured by Toray Industries, Inc.; "Cevian N" manufactured by Daicel Miraizu Corporation, etc. Among them, "LITAC-A 100PCF" manufactured by Japan A&L Corporation; "SANREX SAN-C" manufactured by Techno UMG Corporation; "Denka AS AS-C-820" manufactured by Denka Company, etc. are preferred.

[0082] From the viewpoint of compatibility with the methacrylic resin (M), the content of the styrene unit in the styrene-maleic anhydride copolymer (SMA resin) is preferably 60 to 95% by mass. The lower limit is more preferably 70% by mass, particularly preferably 75% by mass. The upper limit is more preferably 90% by mass, particularly preferably 80% by mass.

[0083] Examples of commercially available SMA resins include "XIRAN" and "XIBOND" manufactured by Polyscope Company; "SMA-700" manufactured by Jiaxing Huawen Chemical Company; "SAM-020" manufactured by Fine-blend Polymer Company, etc.

[0084] From the viewpoint of compatibility with the methacrylic resin (M), the content of the styrene unit 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, particularly preferably 75% by mass. The upper limit is more preferably 90% by mass, particularly preferably 80% by mass.

[0085] Examples of commercially available SMM resins include "RESISFY R-200" manufactured by Denka Company, etc.

[0086] In the surface layer, the total amount of one or more styrenic copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), and styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin) 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.

[0087] When the amount of methyl methacrylate-styrene copolymer (MS resin) is small, it can be compatible with methacrylic resin (M) and can be used. When using methyl methacrylate-styrene copolymer (MS resin), it is preferably used in combination with styrene copolymers such as acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), and styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin) that have excellent compatibility with methacrylic resin (M).

[0088] 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 methacrylic resin (M), the content of styrene units in methyl methacrylate-styrene copolymer (MS resin) is preferably 35 to 50% by mass. The upper limit is more preferably 45% by mass.

[0089] Examples of commercially available products of MS resin include: "TOYO MS MS600" manufactured by Toyo Styrene Co., Ltd.; "DENKA TX POLYMER TX-100S" manufactured by Denka Co., Ltd.; "Cevian NAS" manufactured by Daicel Miraizu Co., Ltd., etc.

[0090] The styrene copolymer (S) may include one or more styrene copolymers (SX) that are binary copolymers of styrene monomer units (S) and other monomer units (X).

[0091] In the styrene copolymer (SX), there are included a triad sequence (SSS) of styrene monomer unit (S)-styrene monomer unit (S)-styrene monomer unit (S), a triad sequence (XSS) of other monomer unit (X)-styrene monomer unit (S)-styrene monomer unit (S), and a triad sequence (XSX) of other monomer unit (X)-styrene monomer unit (S)-other monomer unit (X). The ratio of each triad sequence can be determined from the 13 C-NMR spectrum measured under the condition that the measurement mode is the gated decoupling method.

[0092] From the viewpoint of compatibility with methacrylic resin (M), the styrene copolymer (SX) is preferably such that, relative to a total of 100 mol% of the triad sequence (SSS), the triad sequence (XSS), and the triad sequence (XSX), the ratio of the triad sequence (SSS) is 0 to 40 mol%, and the ratio of the triad sequence (XSX) is 5 to 34 mol%.

[0093] The lower limit value of the ratio of the triad sequence (SSS) is preferably 10 mol%, more preferably 15 mol%. The upper limit value of the ratio of the triad sequence (SSS) is preferably 37 mol%, more preferably 35 mol%.

[0094] The lower limit value of the ratio of the triad sequence (XSX) is preferably 10 mol%, more preferably 15 mol%, particularly preferably 20 mol%. The upper limit value of the ratio of the triad sequence (XSX) is preferably 32 mol%, more preferably 30 mol%.

[0095] The ratio of the triad sequence (XSS) is not particularly limited and is preferably 40 to 80 mol%. The lower limit value of the ratio of the triad sequence (XSS) is more preferably 50 mol%, particularly preferably 55 mol%. The upper limit value of the ratio of the triad sequence (XSS) is more preferably 75 mol%, particularly preferably 70 mol%.

[0096] There is no particular limitation on the other monomer unit (X) contained in the styrenic copolymer (SX). Examples of the styrenic copolymer (SX) include one or more styrenic copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), and methyl methacrylate-styrenic copolymer (MS resin). Among them, from the aspect of excellent compatibility with the methacrylic resin (M), one or more styrenic copolymers selected from the group consisting of acrylonitrile-styrene copolymer (AS resin) and styrene-maleic anhydride copolymer (SMA resin) are preferred.

[0097] When the styrenic copolymer (SX) is an acrylonitrile-styrene copolymer (AS resin), the styrenic monomer unit (S) is a styrene unit, and the other monomer unit (X) is an acrylonitrile unit. As the styrenic copolymer (SX), an AS resin with a ratio of the triad sequence (SSS) of 0 to 40 mol% and a ratio of the triad sequence (XSX) of 5 to 34 mol% can be preferably used.

[0098] When the styrenic copolymer (SX) is a styrene-maleic anhydride copolymer (SMA resin), the styrenic monomer unit (S) is a styrene unit, and the other monomer unit (X) is a maleic anhydride unit. In the present invention, as the styrenic copolymer (SX), an SMA resin with a ratio of the triad sequence (SSS) of 0 to 40 mol% and a ratio of the triad sequence (XSX) of 5 to 34 mol% can be preferably used.

[0099] When the styrenic copolymer (SX) is a methyl methacrylate-styrenic copolymer (MS resin), the styrenic monomer unit (S) is a styrene unit and the other monomer unit (X) is a methyl methacrylate unit. In the present invention, as the styrenic copolymer (SX), an MS resin having a ratio of the triad sequence (SSS) of 0 to 40 mol% and a ratio of the triad sequence (XSX) of 5 to 34 mol% can be used.

[0100] From the aspect of good compatibility with the methacrylic resin (M), the styrenic copolymer (S) preferably contains one or more acrylonitrile-styrenic copolymers (AS), and more preferably contains one or more of the following acrylonitrile-styrenic copolymers (AS-E) having specific properties.

[0101] When the acrylonitrile-styrenic copolymer (AS-E) is subjected to gradient high performance liquid chromatography (gradient HPLC) analysis using two liquids, n-hexane and chloroform, as eluents under the following conditions, the ratio of the copolymer having a composition with an elution time of 9 minutes or less is 0 to 5% by mass, the ratio of the copolymer having a composition with an elution time of 23 minutes or more is 0 to 5% by mass, and the elution time at the peak top of the maximum peak in the chromatogram is 9 to 23 minutes.

[0102] <Conditions for gradient high performance liquid chromatography (gradient HPLC) analysis>

[0103] As the column, a silica gel column having an inner diameter of 4.6 mmφ and a length of 25 cm, filled with spherical totally porous silica gel having a particle diameter of 5 μm, is used. The column temperature is set at 40°C. Using chloroform as the solvent, a sample solution with a concentration of 0.5 mg / mL is prepared.

[0104] When the time from the start of analysis is set as T (minutes), the gradient curve of the mobile phase is as follows.

[0105] From T = 0 to T = 5, the mobile phase is a n-hexane / chloroform mixed solution (50 vol% / 50 vol%).

[0106] From T = 5 to T = 20, the chloroform concentration in the mobile phase is increased from 50 vol% to 100 vol% at a constant rate.

[0107] From T = 20 to T = 25, the mobile phase is 100 vol% chloroform.

[0108] The flow rate of the mobile phase is 0.8 mL / min.

[0109] As the detector, an absorbance detector with a detection wavelength of 260 nm is used.

[0110] According to the research of the present inventors, in the above-mentioned gradient HPLC analysis, the ratio of the copolymer eluted very quickly with an elution time of less than 9 minutes is below the above upper limit value, the ratio of the copolymer eluted very slowly with an elution time of 23 minutes or more is below the above upper limit value, and the acrylonitrile-styrene copolymer (AS-E) with an elution time of the peak top of the chromatogram being 9 to 23 minutes and the methacrylic resin (M) have excellent compatibility and are preferred.

[0111] From the viewpoint of compatibility with the methacrylic resin (M), in the above-mentioned gradient HPLC analysis, the upper limit value of the ratio of the copolymer with a composition having an elution time of less than 9 minutes is preferably 4% by mass, more preferably 3% by mass, particularly preferably 2% by mass, and most preferably 1% by mass.

[0112] From the viewpoint of compatibility with the methacrylic resin (M), in the above-mentioned gradient HPLC analysis, the upper limit value of the ratio of the copolymer with a composition having an elution time of 23 minutes or more is preferably 4% by mass, more preferably 3% by mass.

[0113] From the viewpoint of compatibility with the methacrylic resin (M), the lower limit value of the elution time of the peak top of the chromatogram obtained in the above-mentioned gradient HPLC analysis is more preferably 10 minutes, particularly preferably 12 minutes, and most preferably 15 minutes.

[0114] From the viewpoint of compatibility with the methacrylic resin (M), the upper limit value of the elution time of the peak top of the chromatogram obtained in the above-mentioned gradient HPLC analysis is more preferably 22 minutes, particularly preferably 21 minutes, and most preferably 20 minutes.

[0115] From the viewpoints of compatibility with the methacrylic resin (M) and transparency of the substrate layer, the maximum peak of the chromatogram obtained in the above-mentioned gradient HPLC analysis is preferably: the peak width (W 0.05h ) at the 5% height position measured according to JIS K0124 is 1 to 5 minutes, and the symmetry factor (S) measured according to JIS K0124 is 1.2 to 3.4.

[0116] The lower limit value of the peak width (W 0.05h ) at the 5% height position is more preferably 2 minutes, particularly preferably 3 minutes, and most preferably 4 minutes.

[0117] The lower limit value of the symmetry factor (S) is more preferably 1.3, particularly preferably 1.4, and most preferably 1.5. The upper limit value of the symmetry factor (S) is more preferably 3.2, further preferably 3.0, further preferably 2.8, particularly preferably 2.5, and most preferably 2.0.

[0118] For specific examples of gradient HPLC analysis and determination of various parameters, refer to the [Examples] section described below.

[0119] Impact-resistant polystyrene (HIPS resin) obtained by graft copolymerization of acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), and butadiene has poor compatibility with methacrylic resin (M), and therefore is preferably not used as styrene copolymer (S).

[0120] Within the range that satisfies the property that the haze value of a 3.0 mm thick single-layer formed sheet of the pulverized product of the laminated sheet of the present invention is 4% or less, the surface layer may optionally contain one or more methacrylic resins (M) and / or one or more other acrylic resins (A) other than methacrylic resin (M). Examples of the optional other acrylic resin (A) are the same as those of the base material layer. It should be noted that the methacrylic resin (M) in the surface layer may be the same as or different from the methacrylic resin (M) in the base material layer. The same applies to the optional other acrylic resin (A). The content of methacrylic resin (M) and / or other acrylic resin (A) in the surface layer (in the case of two or more, the total amount) is preferably 0 to 10% by mass. The upper limit value is more preferably 5% by mass, and particularly preferably 2% by mass.

[0121] Within the range that satisfies the property that the haze value of a 3.0 mm thick single-layer formed sheet of the pulverized product of the laminated sheet of the present invention is 4% or less, the surface layer may optionally contain one or more other polymers other than styrene polymer (S), methacrylic resin (M), and other acrylic resin (A). There is no particular limitation on the other polymer, and examples include: other thermoplastic resins such as polyolefins such as polyethylene and polypropylene, polyamides, polyphenylene sulfides, polyether ether ketones, polyesters, polysulfones, polyphenylene ethers, polyimides, polyether imides, and polyacetals; thermosetting resins such as phenolic resins, melamine resins, silicone resins, and epoxy resins, etc. The content of the other polymer in the surface layer is preferably 0 to 10% by mass. The upper limit value is more preferably 5% by mass, and particularly preferably 2% by mass. The surface layer may not contain other polymers other than styrene polymer (S), methacrylic resin (M), and other acrylic resin (A).

[0122] Within the range where the haze value of the 3.0 mm thick single-layer formed sheet of the pulverized product of the laminated sheet of the present invention is 4% or less, the surface layer may contain various additives as needed. Examples of the additives include: colorants, antioxidants, thermal degradation inhibitors, ultraviolet absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, light diffusing agents, matting agents, rubber components such as core-shell particles and block copolymers (impact resistance modifiers), and phosphors. The content of the additives may be appropriately set within the range that does not impair the effects of the present invention. Preferably: with respect to 100 parts by mass of the constituent resin of the surface layer (the total in the case of two or more kinds is 100 parts by mass), for example, the content of the antioxidant is 0.01 to 1 part by mass, the content of the ultraviolet absorber is 0.01 to 3 parts by mass, the content of the light stabilizer is 0.01 to 3 parts by mass, and the content of the lubricant is 0.01 to 3 parts by mass.

[0123] When adding other polymers and / or additives to the surface layer, the addition timing may be during the polymerization of the styrenic copolymer (S) or after the polymerization.

[0124] The glass transition temperature (Tg) of the constituent resin of the surface layer (the mixed resin composition in the case of two or more kinds) is not particularly limited, and is preferably 80 to 160 °C, more preferably 100 to 110 °C.

[0125] (Base material layer)

[0126] The base material 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 value is preferably 90% by mass, more preferably 95% by mass.

[0127] The methacrylic resin (M) may contain one or more (meth)acrylate units other than MMA units. Examples of the (meth)acrylate other than MMA include methyl acrylate (MA), ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-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, 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, tolyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, 3-dimethylaminoethyl (meth)acrylate, and the like. Among them, from the viewpoint of transparency, MA is preferred. For example, a copolymer of MMA and MA has excellent transparency and is preferred.

[0128] In this specification, "(meth)acryl..." is a general term for acryl... and methacryl..., and the same applies to (meth)acrylic acid, (meth)acrylonitrile, and the like.

[0129] The base material layer may contain, as needed, one or more other acrylic resins (A) in addition to the methacrylic resin (M). The "other acrylic resin (A)" described in this specification refers to a methacrylic resin having a MMA unit content of less than 80% by mass, and a (meth)acrylic resin that does not contain MMA units but contains one or more (meth)acrylate units other than MMA units.

[0130] The methacrylic resin (M) and the other acrylic resin (A) may contain structural units derived from one or more other monomers in addition to (meth)acrylate. 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; maleimide such as phenylmaleimide and cyclohexylmaleimide; styrene monomers such as styrene, α-methylstyrene, and vinyltoluene.

[0131] The content (total amount in the case of two or more) of structural units derived from monomers other than (meth)acrylate in the methacrylic resin (M) and other acrylic resins (A) is preferably 0 to 10% by mass. The upper limit is more preferably 5% by mass, particularly preferably 2% by mass.

[0132] The styrenic monomer units in the methacrylic resin (M) and other acrylic resins (A) (total amount in the case of two or more) are 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. The methacrylic resin (M) and other acrylic resins (A) may not contain styrenic monomer units.

[0133] The methacrylic resin (M) and other acrylic resins (A) are obtained by polymerizing one or more (meth)acrylates and, if necessary, other monomers. When using two or more monomers, usually, a monomer mixture is prepared by mixing the two or more monomers and then polymerized. As the polymerization method, there is no particular limitation, and from the viewpoint of productivity, radical polymerization methods such as bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization are preferred.

[0134] Within the range satisfying the property that the haze value of a 3.0-mm-thick single-layer formed sheet of the pulverized product of the laminated sheet of the present invention is 4% or less, the base material layer may contain one or more styrenic copolymers (S) as needed. That is, the base material layer may contain a methacrylic resin composition (MR) containing a methacrylic resin (M) and a styrenic copolymer (S). It should be noted that the styrenic copolymer (S) in the base material layer may be the same as or different from the styrenic copolymer (S) in the surface layer.

[0135] When the base material layer contains styrenic monomer units, there is a tendency to effectively suppress the amount of warpage change of the laminated sheet after standing in a high-humidity environment.

[0136] Generally, in the manufacture of (co)extruded formed sheets and formed articles using such (co)extruded formed sheets, there are defective products generated at the start of the extrusion forming production line, scrap materials generated by trimming the end portions of the sheet, defective products that are judged not to meet the product standards due to defects and foreign matters in quality inspection, and scrap materials generated by cutting the sheet. In recent years, efforts towards a sustainable society have been promoted, and it is preferable to reuse the above-mentioned defective products and scrap materials as recycled materials without discarding them for effective utilization.

[0137] In this specification, "virgin material" refers to a molding material that has never been used for molding processing in the past, and "recycled material" refers to a molding material that has been subjected to molding processing one or more times as a molded product in the past.

[0138] At least a part of all the raw materials of the base material layer may be a recycled resin composition (R) (also referred to as recycled material) composed of the pulverized product of the laminated sheet of the present invention manufactured in the past or the processed product of the pulverized product. Examples of the form of the processed product include wire materials and pellet materials.

[0139] As described above, the haze value of the 3.0 mm thick single-layer molded sheet of the pulverized product of the laminated sheet of the present invention is 4% or less. Therefore, by using a recycled resin composition (R) composed of the pulverized product of the laminated sheet of the present invention manufactured in the past or the processed product of the pulverized product as at least a part of all the raw materials of the base material layer, a laminated sheet of the present invention with excellent transparency can be manufactured.

[0140] The content of the styrenic monomer unit in the base material layer is not particularly limited, and is preferably 0 to 10.0% by mass. The lower limit value is more preferably 0.5% by mass, further preferably 0.7% by mass, particularly preferably 0.8% by mass, and most preferably 1.0% by mass.

[0141] Patent Document 3 listed in the [Background Art] section describes that "in order to suppress the generation of cloudiness and maintain transparency, the styrene content in the base material layer is preferably 1% by mass or less, and more preferably 0.85% by mass or less." (Paragraph 0171).

[0142] In the technology of the present invention, the content of the styrenic monomer unit in the base material layer can be more than the range described in Patent Document 3, and can be set to 1.2% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, or 4.0% by mass or more. The upper limit value is more preferably 9.0% by mass, particularly preferably 8.5% by mass, and most preferably 8.0% by mass.

[0143] The styrenic copolymer (S) contained in the base material layer has excellent compatibility with the methacrylic resin (M). Therefore, the base material layer can have the following phase structure and excellent transparency.

[0144] The base material layer may have a completely compatible structure composed of a homogeneous phase in which the styrenic copolymer (S) and the methacrylic resin (M) are completely compatible in an electron microscope image (preferably a transmission electron microscope image (TEM image)).

[0145] The base material layer may alternatively have, in an electron microscope image (preferably a transmission electron microscope image (TEM image)), a microphase separation structure (island structure) in which a plurality of particulate island phases containing a styrenic copolymer (S) are dispersed in a sea phase containing a methacrylic resin (M), and the maximum diameter of the plurality of particulate island phases is greater than 0 nm and 50 nm or less. The island phase is also referred to as a discontinuous phase or a domain. The sea phase is also referred to as a continuous phase or a matrix. The island phase may contain a styrenic copolymer (S) and a methacrylic resin (M).

[0146] The maximum diameter of the plurality of particulate island phases in the phase structure and the microphase separation structure (island structure) of the base material layer can be determined by electron microscope observation. The specific determination method is described in the [Examples] section below.

[0147] It should be noted that, in this specification, unless otherwise specified, the diameter of any non-circular island phase refers to the maximum diameter (also referred to as the longest diameter) of the island phase. The maximum diameter of the plurality of particulate island phases refers to the diameter of the largest island phase among 100 randomly selected particulate island phases with the largest diameter.

[0148] From the viewpoint of transparency, it is more preferable that the maximum diameter of the plurality of particulate island phases is smaller, and the upper limit value is preferably 40 nm, more preferably 30 nm, further preferably 20 nm, further preferably 10 nm, and particularly preferably 5 nm.

[0149] The base material layer most preferably has a completely compatible structure composed of a homogeneous phase in which a styrenic copolymer (S) and a methacrylic resin (M) are completely compatible in an electron microscope image (preferably a transmission electron microscope image (TEM image)).

[0150] Within the range of satisfying the property that the haze value of a 3.0 mm thick single-layer formed sheet of the pulverized product of the laminate sheet of the present invention is 4% or less, the base material layer may contain, as needed, one or more other polymers in addition to the methacrylic resin (M), other acrylic resins (A), and styrenic polymers (S). The base material layer may contain various additives as needed. Examples of the types of other polymers and additives and the preferred addition amounts are the same as those of the surface layer.

[0151] The glass transition temperature (Tg) of the constituent resin (in the case of two or more, a mixed resin composition) of the base material layer is not particularly limited, and is preferably 100 to 140 °C, more preferably 105 to 135 °C, and particularly preferably 105 to 125 °C.

[0152] [Method for manufacturing a laminate sheet]

[0153] The laminated sheet of the present invention can be manufactured by a known sheet forming method. From the viewpoints of production efficiency and interlayer adhesiveness, an extrusion forming method or the like is preferred. In the case of the extrusion forming method, co-extrusion forming is preferably performed in which a base material layer material containing a methacrylic resin (M) or a methacrylic resin composition (MR) and a surface layer material containing a styrene copolymer (S) after melt kneading are co-extruded from a common extrusion die (such as a T-die) using different extruders.

[0154] As the mode of the co-extrusion die, a multi-manifold die mode and a feed block mode can be cited. In the feed block mode, a molten base material layer material containing a methacrylic resin (M) or a methacrylic resin composition (MR) and a molten surface layer material containing a styrene copolymer (S) are laminated in the feed block and then introduced into a T-die or the like to be formed into a sheet and co-extruded. In the multi-manifold die mode, a molten base material layer material containing a methacrylic resin (M) or a methacrylic resin composition (MR) and a molten surface layer material containing a styrene copolymer (S) are introduced into a T-die or the like to be formed into a sheet, and then laminated and co-extruded. For the laminated sheet of the present invention, the surface layer is designed to be thin. In this case, the multi-manifold die mode is preferred.

[0155] In any mode, the thermoplastic resin laminate extruded from a T-die or the like is cooled through the gap between at least a pair of cooling and pressing rolls and then pulled by a pulling roll. The above-mentioned co-extrusion, cooling, and pulling processes are continuously carried out. It should be noted that in this specification, the material in a heated and molten state is mainly referred to as a "thermoplastic resin laminate", and the solidified material is referred to as a "laminated sheet", but there is no clear boundary between the two.

[0156] In the co-extrusion forming of the laminated sheet of the present invention, the temperature (Td) of the T-die is preferably 190 to 280 °C. When Td is lower than 190 °C, the melt viscosities of the methacrylic resin (M) or the methacrylic resin composition (MR) and the styrene copolymer (S) become too high, and it may not be possible to extrude and form these resins well. When Td exceeds 280 °C, the styrene copolymer (S) may decompose due to high temperature. Td is more preferably 210 to 270 °C, and particularly preferably 230 to 260 °C.

[0157] The die lip thickness of the T-die can be designed according to the total thickness of the desired laminated sheet (preferably 1 to 10 mm).

[0158] The pulling speed (V) of the laminated sheet by a pair of pulling rolls is not particularly limited, and is preferably 0.5 to 2.0 m / minute.

[0159] In the method for manufacturing the laminated sheet of the present invention, a recycled resin composition (R) composed of the pulverized product of the laminated sheet of the present invention manufactured in the past or a processed product of the pulverized product is used as at least a part of all the raw materials of the base material layer, and the laminated sheet of the present invention can be coextrusion molded.

[0160] The proportion of the recycled resin composition (R) in all the raw materials of the base material layer is not particularly limited, and can be, for example, 1 to 100% by mass. In the technology of the present invention, the proportion of the recycled resin composition (R) in all the raw materials of the base material layer can be increased, and can be set to 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.

[0161] Generally, if the recycling of the same material is repeated, the quality of the recycled material sometimes deteriorates, and the haze value of the laminated sheet using the recycled material becomes high. It is preferable to consider the number of recycling times or the quality of the recycled material, and adjust the use ratio of the recycled material within the range that satisfies the characteristic that the haze value of the 3.0 mm thick single-layer molded sheet of the pulverized product of the laminated sheet of the present invention is 4% or less.

[0162] Even when at least a part of all the raw materials of the base material layer is a recycled resin composition (R) composed of the pulverized product of the laminated sheet of the present invention manufactured in the past or a processed product of the pulverized product, the transparency of the laminated sheet of the present invention is excellent, and the haze value at 3.0 mm thickness can also be 4% or less, 3% or less, 2% or less, or 1% or less.

[0163] [Printed matter, molded article]

[0164] The laminated sheet of the present invention can be preferably used as a resin sheet for inkjet printing. By performing inkjet printing on the surface layer containing the styrenic copolymer (S) contained in the laminated sheet of the present invention, a printed matter can be provided. The laminated sheet of the present invention can also be cut and processed into a desired shape using a laser, a CNC engraving machine, etc. as needed after inkjet printing.

[0165] The laser cutting processability of the laminated sheet of the present invention is good, so fine cutting process can be performed. For example, a molded article having a curved cutting portion with a radius of 0.5 to 2 mm can be manufactured with good shape accuracy. The laser cutting processability of the laminated sheet of the present invention is good, so using a high-output laser processing machine, cutting process can be performed at high speed and with good productivity. For example, the laminated sheet of the present invention can be cut and processed into a molded article at a speed of 350 cm / minute or more using a laser processing machine with an output power of 100 W or more.

[0166] As described above, according to the present invention, a laminated sheet with good ink adhesion, good laser cutting processability, and excellent sustainability can be provided.

[0167] [Use]

[0168] The laminated sheet, printed matter, and molded article of the present invention can be used in various fields such as printing, advertising, sign display, events, entertainment, architecture, and interior decoration.

[0169] The laminated sheet, printed matter, and molded article of the present invention can preferably be used for sundries such as keychains and daily utensils.

[0170] Examples

[0171] Hereinafter, examples and comparative examples of the present invention will be described.

[0172] [Evaluation Items and Evaluation Methods]

[0173] (Content of styrenic monomer units in styrenic copolymer (S))

[0174] The content of styrenic monomer units (specifically, styrene units) in styrenic copolymer (S) is determined by 1 the 1H-NMR method. Using a nuclear magnetic resonance apparatus (“ULTRA SHIELD 400 PLUS” manufactured by Bruker Corporation), the 1H-NMR spectrum of styrenic copolymer (S) is measured. The styrene unit concentration is determined from the integral value of the peak derived from the hydrogen atoms bonded to the carbon atoms at the 2nd to 6th positions of the aromatic ring contained in styrene. 1

[0175] (Ratio of each triad sequence in styrenic copolymer (SX))

[0176] Dissolve styrenic copolymer (SX) in deuterated chloroform, add 0.5% by mass of chromium(III) acetylacetonate as a relaxation promoter, and prepare a sample solution. For the obtained sample solution, using a nuclear magnetic resonance apparatus (“ULTRA SHIELD 400 PLUS” manufactured by Bruker Corporation), measure the 13C-NMR spectrum under the conditions of temperature: 50 °C and measurement mode: inverse gated decoupling method. 13 13C-NMR spectrum.

[0177] The ratios of the triad sequences (SSS) of styrenic monomer units (S)-styrenic monomer units (S)-styrenic monomer units (S), the triad sequence (XSS) of other monomer units (X)-styrenic monomer units (S)-styrenic monomer units (S), and the triad sequence (XSX) of other monomer units (X)-styrenic monomer units (S)-other monomer units (X) are determined respectively from the integral values of the peaks (136 to 148 ppm) of the carbon atoms at the 1-position of the aromatic rings contained in the styrenic monomer units. It should be noted that the total amount of the triad sequence (SSS), the triad sequence (XSS), and the triad sequence (XSX) is set to 100 mol%.

[0178] When the styrenic copolymer (SX) is acrylonitrile-styrene copolymer (AS resin), the styrenic monomer unit (S) is a styrene unit, and the other monomer unit (X) is an acrylonitrile unit. When the styrenic copolymer (SX) is styrene-maleic anhydride copolymer (SMA resin), the styrenic monomer unit (S) is a styrene unit, and the other monomer unit (X) is a maleic anhydride unit. When the styrenic copolymer (SX) is methyl methacrylate-styrenic copolymer (MS resin), the styrenic monomer unit (S) is a styrene unit, and the other monomer unit (X) is a methyl methacrylate unit.

[0179] (Gradient high performance liquid chromatography (gradient HPLC) analysis)

[0180] Gradient high performance liquid chromatography (gradient HPLC) analysis of acrylonitrile-styrene copolymer (AS) is carried out.

[0181] As the analysis device, a high performance liquid chromatograph (HPLC system "Prominence LC-20AD") manufactured by Shimadzu Corporation is used. As the column, a silica gel column (inner diameter 4.6 mmφ, length 25 cm) filled with spherical fully porous silica gel with a particle size of 5 μm is used. The column temperature is set to 40 °C.

[0182] Chloroform is used as the solvent to prepare a sample solution with a concentration of 0.5 mg / mL. The injection volume of the sample solution into the device is 2 μL.

[0183] The components in the sample solution are separated by gradient elution using two liquids, n-hexane and chloroform, as the eluent. As the mixing method of the two liquids, a high-pressure mixing method in which the two liquids are mixed under pressure is adopted.

[0184] When the time from the start of analysis (the time when the sample solution is injected into the device) is set to T (minutes), the gradient curve of the mobile phase is as follows.

[0185] The mobile phase between T = 0 and T = 5 is a mixed solution of n - hexane / chloroform (50 vol% / 50 vol%, volume ratio 1 / 1).

[0186] Between T = 5 and T = 20, the concentration of chloroform in the mobile phase is increased from 50 vol% to 100 vol% at a constant rate (50 vol% / 15 minutes) (= the concentration of n - hexane in the mobile phase is decreased from 50 vol% to 0 vol% at a constant rate (50 vol% / 15 minutes)).

[0187] The mobile phase between T = 20 and T = 25 is 100 vol% chloroform (also called pure chloroform).

[0188] Between T = 25 and T = 30, the concentration of n - hexane in the mobile phase is increased from 0 vol% to 100 vol% at a constant rate (100 vol% / 5 minutes) (= the concentration of chloroform in the mobile phase is decreased from 100 vol% to 0 vol% at a constant rate (100 vol% / 5 minutes)).

[0189] The mobile phase between T = 30 and T = 60 is a mixed solution of n - hexane / chloroform (50 vol% / 50 vol%, volume ratio 1 / 1).

[0190] The flow rate of the mobile phase is 0.8 mL / minute.

[0191] As the detector, an absorbance detector with a detection wavelength of 260 nm (also called a UV detector) or an evaporative light - scattering (ELS) detector (“ELSD - LTII” manufactured by System Instruments) is used.

[0192] 100 vol% chloroform is used as a blank sample, and gradient high - performance liquid chromatography (gradient HPLC) analysis is performed under the same conditions as when using the sample solution. Based on the baseline slope of the measurement data of this blank sample, baseline correction processing is performed on the measurement data of the sample solution to obtain the chromatogram of the sample solution.

[0193] The elution time of a certain component is the time from the start of analysis (the time when the sample solution is injected into the device) to the detection of the certain component (the time to the peak top of the peak derived from the certain component), which is also called the retention time.

[0194] In the obtained chromatogram, the integral value of the peaks with an elution time of 9 minutes or less, the integral value of the peaks with an elution time of 23 minutes or more, and the integral value of the peaks with an elution time of 9 - 23 minutes are obtained, and from these data, the ratio of the copolymer of the composition with an elution time of 9 minutes or less and the ratio of the copolymer of the composition with an elution time of 23 minutes or more are obtained.

[0195] Determine the elution time at the peak top of the largest peak (also simply referred to as the elution time at the peak top) and the height (h) of the peak top of the largest peak from the baseline (also referred to as the peak height (h)). Additionally, determine the symmetry factor (S) of the largest peak according to JIS K0124.

[0196] The symmetry factor (S) is a parameter represented by the following formula.

[0197] S = (W 0.05h ) / (2f)

[0198] In the above formula, W 0.05h is the peak width at the height position of 5% (1 / 20) of the peak height (h) from the baseline (also referred to as the peak width at 5% height). f is the width of the ascending side of the peak in the peak width obtained by bisecting this peak width (W 0.05h ) with a perpendicular line passing through the peak top and perpendicular to the horizontal axis of the chromatogram. The symmetry factor (S) is an index of the symmetry of the peak.

[0199] It should be noted that for the relationship between the peak height (h), the peak width at 5% height (W 0.05h ) and the parameter (f), refer to, for example, Japanese Patent Laid-Open No. 2016-020435. Figure 1 etc.

[0200] (Haze value of a 3.0-mm thick single-layer formed sheet of the chip pulverizate)

[0201] Weigh 60 g of the laminated or single-layer sheet (L) or (LC) obtained from the examples or comparative examples and pulverize it using a pulverizer. Then, using the "Labo Plastomill (registered trademark)" manufactured by Toyo Seiki Co., Ltd., melt-knead the pulverizate under the conditions of a screw rotation speed of 70 rpm, a kneading time of 3 minutes, and a kneading temperature of 250°C. Next, using a 50 mm × 150 mm mirror mold, hot-press the obtained melt-kneaded material at a forming temperature of 250°C to obtain a 3.0-mm thick single-layer formed sheet. It should be noted that the above melt-kneading temperature and forming temperature (both 250°C) are the maximum temperatures of the extruder for the base material layer material used in the [Examples] section. Measure the haze value of the obtained single-layer formed sheet using the "HM-150" manufactured by Murakami Color Research Institute Co., Ltd.

[0202] (Haze value of the laminated or single-layer sheet (L) or (LC))

[0203] Cut out a 50 mm × 50 mm test piece from the central part in the width direction of the laminated or single-layer sheet (L) or (LC) obtained from the examples or comparative examples, and measure the haze value using the "HM-150" manufactured by Murakami Color Research Institute Co., Ltd.

[0204] (Phase structure of the base material layer)

[0205] A test piece with a thickness of 70 nm was cut out from the base material layer of the laminated sheet made from recycled materials, and stained using phosphotungstic acid (PTA) as a stain. A transmission electron microscope image (TEM image) of the phase structure of the base material layer was observed using a field emission scanning electron microscope (FE-SEM) ("JSM-7600F" manufactured by JEOL Ltd.) and its optional transmission electron detector, and evaluated according to the following criteria.

[0206] When the styrenic copolymer (S) and the methacrylic resin (M) are completely compatible and form a homogeneous phase, it is judged that the compatibility is good (A).

[0207] In the case where a microphase separation structure (island structure) in which a plurality of particulate island phases containing the styrenic copolymer (S) are dispersed in the sea phase containing the methacrylic resin (M) is confirmed, the largest island phase among 100 randomly selected particulate island phases is determined, and the diameter of this largest island phase is obtained as the "maximum diameter of the plurality of particulate island phases". When the maximum diameter of the plurality of particulate island phases is greater than 0 nm and 50 nm or less, it is judged that the compatibility is qualified (B), and when the maximum diameter of the plurality of particulate island phases exceeds 50 nm, it is judged that the compatibility is poor (C).

[0208] (Ink adhesion)

[0209] The ink adhesion of the laminated or single-layer sheet subjected to inkjet printing was evaluated. In the printed layer composed of the cured products of white and black UV-curable inks, a 10 mm square evaluation area was cross-cut into 100 grids (10 grids in length × 10 grids in width) at 1 mm intervals in both the vertical and horizontal directions. A transparent tape was integrally pasted on this evaluation area, and after rubbing it with a rubber so that the transparent tape was sufficiently adhered to the printing surface, the transparent tape was peeled off along the 90° direction. Observation was carried out using a magnifying glass with a magnification of 10 times, and the number of grids in which the ink was peeled off from the resin sheet among the 100 grids to be evaluated was obtained. The evaluation criteria are as follows.

[0210] A (excellent): No ink peeling was observed in all grids.

[0211] B (good): Ink peeling was observed in more than 1 and less than 10 grids.

[0212] C (qualified): Ink peeling was observed in more than 10 and less than 50 grids.

[0213] D (unqualified): Ink peeling was observed in more than 50 grids.

[0214] (Laser cutting processability)

[0215] Evaluate the laser cutting processability of laminated or single-layer sheets that have undergone inkjet printing.

[0216] <Appearance of the cut surface>

[0217] For 10 formed products obtained after laser cutting, evaluate the presence or absence of defects on the cut surface of the 30 cm straight cutting part through optical microscope observation and touch inspection. The main defects are as follows.

[0218] Rough: The entire cut surface is uneven and has a rough feeling when touched.

[0219] Corner roughness: There is local roughness at the corners of the cut surface, and it has a rough feeling when touched.

[0220] Resin accumulation: Molten resin accumulation is observed in a part of the cut surface.

[0221] Foreign matter: Colored foreign matter is observed on the cut surface.

[0222] The evaluation criteria are as follows.

[0223] A (excellent): The number of formed products with observed defects is 0 - 1.

[0224] B (good): The number of formed products with observed defects is 2 - 4.

[0225] C (unqualified): The number of formed products with observed defects is 5 - 10.

[0226] <Presence or absence of smoking or abnormal odor>

[0227] Conduct a sensory evaluation on the presence or absence of smoking or abnormal odor during laser cutting. The evaluation criteria are as follows.

[0228] A (good): There is a small amount of smoking or abnormal odor, but it is at an acceptable level.

[0229] B (qualified): Between A and C.

[0230] C (poor): Smoking or abnormal odor is obvious.

[0231] [Materials]

[0232] The materials used are as follows.

[0233] (Methacrylic resin (M))

[0234] <PMMA1>Methyl methacrylate - methyl acrylate copolymer, "PARAPET" manufactured by Kuraray Co., Ltd., content of methyl methacrylate unit: 94% by mass, content of methyl acrylate unit: 6% by mass, content of styrene unit: 0% by mass.

[0235] (Acrylonitrile-styrene copolymer (AS resin))

[0236] <AS1> “LITAC-A 100PCF” manufactured by A&L Japan Co., Ltd., content of styrene unit: 77% by mass,

[0237] <AS2> “SANREX AN-C” manufactured by Techno UMG Co., Ltd., content of styrene unit: 76% by mass,

[0238] <AS3> “Denka AS S-C-820” manufactured by Denka Co., Ltd., content of styrene unit: 82% by mass,

[0239] <AS4> “Denka AS GR-AT-6S” manufactured by Denka Co., Ltd., content of styrene unit: 67% by mass,

[0240] <AS5> “Cevian-N 020SF” manufactured by Daicel Miraizu Co., Ltd., content of styrene unit: 74% by mass.

[0241] (SMA resin (composition))

[0242] <SMA1>

[0243] As the styrene-maleic anhydride copolymer (SMA resin), “XIRAN23110” manufactured by Polyscope Co., Ltd. (content of styrene unit: 77% by mass) was prepared.

[0244] <SMA / PMMA1>

[0245] The SMA resin (SMA1) and the methacrylic resin (PMMA1) were melt-kneaded at a mass ratio of 1:1 to obtain an SMA resin composition (SMA / PMMA1) (content of styrene unit: 38.5% by mass).

[0246] (Methyl methacrylate-styrene copolymer (MS resin))

[0247] <MS200> “TOYO MS MS200” manufactured by Toyo Styrene Co., Ltd., content of styrene unit: 80% by mass,

[0248] <MS600> “TOYO MS MS600” manufactured by Toyo Styrene Co., Ltd., content of styrene unit: 40% by mass.

[0249] [Evaluation results of the ratio of each triad sequence in the styrene copolymer (SX)]

[0250] Typically, the 13 C-NMR spectrum of acrylonitrile-styrene copolymer (AS1) measured under the condition that the measurement mode is the inverse gated decoupling method is shown in Figure 2 . Figure 2 In , for the triad sequence (SSS), the triad sequence (ASS), and the triad sequence (ASA), the peaks (136 to 148 ppm) of the carbon atoms at the 1-position of the aromatic ring contained in the styrene unit are shown respectively. Here, the symbol A represents an acrylonitrile unit as the other monomer unit (X).

[0251] The evaluation results of the ratios of the respective triad sequences in the main styrenic copolymers (SX) used in the examples and comparative examples are shown in Table 1.

[0252]

[0253] [Gradient HPLC analysis results]

[0254] The chromatograms of acrylonitrile-styrene copolymers (AS1) to (AS3), (AS5) after baseline correction processing when a UV detector with a detection wavelength of 260 nm is used as the detector in gradient high performance liquid chromatography (gradient HPLC) analysis are shown in Figure 3 . The gradient HPLC analysis results of these acrylonitrile-styrene copolymers are shown in Table 2.

[0255]

[0256] [Manufacture of laminated or single-layer sheet]

[0257] (Examples (E1-V) to (E9-V), Comparative Examples (EC10-V) to (EC12-V), (EC15-V) to (EC17-V))

[0258] As the base material layer material, the virgin methacrylic resin (M) is melted using a 150 mmφ single-screw extruder manufactured by Toshiba Machine Co., Ltd. (the maximum temperature of the barrel part is 250°C). As the surface layer material, the virgin styrene copolymer (S) is melted using a 65 mmφ single-screw extruder manufactured by Toshiba Machine Co., Ltd. (the maximum temperature of the barrel part is 240°C). Using a multi-manifold die, the molten styrene copolymer (S), the molten methacrylic resin (M), and the molten styrene copolymer (S) are laminated in sequence, extruded from a T-die head, cooled using four adjacent cooling rolls, and pulled by a take-up roll. Through the above co-extrusion molding, two three-layer laminated sheets (L1-V) to (L9-V), (LC10-V) to (LC12-V), (LC15-V) to (LC17-V) of styrene copolymer (S) (first surface layer) / methacrylic resin (M) (base material layer) / styrene copolymer (S) (second surface layer) are manufactured.

[0259] The main manufacturing conditions and various parameter values are shown in Tables 3 and 6. In these tables, the conditions not recorded in the tables are common conditions. It should be noted that for the first surface layer and the second surface layer, the composition and thickness are set to the same conditions. The thickness of each surface layer is half of the value of the "total thickness of the surface layer" recorded in Tables 3 and 6.

[0260] (Comparative Examples (EC13-V), (EC14-V))

[0261] The virgin styrene copolymer (S) or the virgin methacrylic resin (M) is melted using a 150 mmφ single-screw extruder manufactured by Toshiba Machine Co., Ltd. (the maximum temperature of the barrel part is 250°C). The molten resin is extruded from a T-die head, cooled using four adjacent cooling rolls, and pulled by a take-up roll. Through the above extrusion molding, single-layer sheets (LC13-V), (LC14-V) are manufactured. The main manufacturing conditions and various parameter values are shown in Table 6.

[0262] (Examples (E1-1) to (E1-3))

[0263] At least a part (30 mass%, 50 mass%, or 100 mass%) of the base material layer material is replaced with the pulverized product of the laminated sheet obtained in Example (E1-V) as the recycled material, and the same operations as in Example (E1-V) are performed except for this, to obtain laminated sheets (L1-1) to (L1-3). The main manufacturing conditions and various parameter values are shown in Table 4.

[0264] It should be noted that the mixing of the virgin methacrylic resin (M) and the recycled material is carried out by dry mixing. The same applies to other examples.

[0265] (Examples (E2-1) to (E2-3))

[0266] Replace at least a part (30 mass%, 50 mass%, or 100 mass%) of the base material layer material with the pulverized product of the laminated sheet obtained in Example (E2-V) as a recycled material, and perform the same operations as in Example (E2-V) except for this, to obtain laminated sheets (L2-1) to (L2-3). The main manufacturing conditions and various parameter values are shown in Table 4.

[0267] (Examples (E3-1) to (E3-2))

[0268] Replace a part (30 mass% or 40 mass%) of the base material layer material with the pulverized product of the laminated sheet obtained in Example (E3-V) as a recycled material, and perform the same operations as in Example (E3-V) except for this, to obtain laminated sheets (L3-1) to (L3-2). The main manufacturing conditions and various parameter values are shown in Table 4.

[0269] (Examples (E4-1) to (E4-3))

[0270] Replace at least a part (30 mass%, 50 mass%, or 100 mass%) of the base material layer material with the pulverized product of the laminated sheet obtained in Example (E4-V) as a recycled material, and perform the same operations as in Example (E4-V) except for this, to obtain laminated sheets (L4-1) to (L4-3). The main manufacturing conditions and various parameter values are shown in Table 4.

[0271] (Example (E5-1))

[0272] Replace a part (50 mass%) of the base material layer material with the pulverized product of the laminated sheet obtained in Example (E5-V) as a recycled material, and perform the same operations as in Example (E5-V) except for this, to obtain a laminated sheet (L5-1). The main manufacturing conditions and various parameter values are shown in Table 5.

[0273] (Examples (E6-1) to (E6-3))

[0274] Replace at least a part (30 mass%, 50 mass%, or 100 mass%) of the base material layer material with the pulverized product of the laminated sheet obtained in Example (E6-V) as a recycled material, and perform the same operations as in Example (E6-V) except for this, to obtain laminated sheets. The main manufacturing conditions and various parameter values are shown in Table 5.

[0275] (Example (E7-1))

[0276] Replace a part (50% by mass) of the base material layer material with the crushed product of the laminated sheet obtained in Example (E7-V) as the recycled material, and perform the same operations as in Example (E7-V) to obtain a laminated sheet (L7-1). The main manufacturing conditions and various parameter values are shown in Table 5.

[0277] (Examples (E8-1) to (E8-3))

[0278] Replace at least a part (30% by mass, 50% by mass, or 100% by mass) of the base material layer material with the crushed product of the laminated sheet obtained in Example (E8-V) as the recycled material, and perform the same operations as in Example (E8-V) to obtain a laminated sheet. The main manufacturing conditions and various parameter values are shown in Table 5.

[0279] (Example (E9-1))

[0280] Replace a part (50% by mass) of the base material layer material with the crushed product of the laminated sheet obtained in Example (E9-V) as the recycled material, and perform the same operations as in Example (E9-V) to obtain a laminated sheet (L9-1). The main manufacturing conditions and various parameter values are shown in Table 5.

[0281] (Comparative Examples (EC10-1), (EC11-1), (EC12-1), (EC15-1))

[0282] Replace a part (30% by mass) of the base material layer material with the crushed product of the laminated sheet obtained in Comparative Examples (EC10-V), (EC11-V), (EC12-V), or (EC15-V) as the recycled material, and perform the same operations as in Comparative Examples (EC10-V), (EC11-V), (EC12-V), or (EC15-V) to obtain laminated sheets (LC10-1), (LC11-1), (LC12-1), (LC15-1). The main manufacturing conditions and various parameter values are shown in Table 7.

[0283] (Comparative Examples (EC16-1) to (EC16-3))

[0284] Replace at least a part (30% by mass, 50% by mass, or 100% by mass) of the base material layer material with the crushed product of the laminated sheet obtained in Comparative Example (EC16-V) as the recycled material, and perform the same operations as in Comparative Example (EC16-V) to obtain laminated sheets (LC16-1) to (LC16-3). The main manufacturing conditions and various parameter values are shown in Table 7.

[0285] (Comparative Examples (EC17-1) to (EC17-3))

[0286] At least a part (30% by mass, 50% by mass, or 100% by mass) of the base material layer material was replaced with the crushed material of the laminated sheet obtained in Comparative Example (EC17-V) which is recycled material, and the operation was carried out in the same manner as in Comparative Example (EC17-V) except for this, to obtain a laminated sheet. The main manufacturing conditions and various parameter values are shown in Table 7.

[0287] [Inkjet printing]

[0288] Under the following conditions, inkjet printing was carried out on one surface of the laminated or single-layer sheet obtained in each example, and the above-mentioned ink adhesion evaluation was carried out. The printing pattern was an approximately elliptical solid printing with a minor axis of 1.8 cm and a major axis of 2.8 cm.

[0289] Apparatus: "LEF-300" manufactured by Roland DG Corporation,

[0290] Temperature: Room temperature (20 - 25 °C),

[0291] UV curable ink (white): EUV-BK manufactured by Roland DG Corporation,

[0292] UV curable ink (black): EUV-WH manufactured by Roland DG Corporation.

[0293] [Laser cutting]

[0294] Under the following conditions, laser cutting was carried out on the laminated or single-layer sheet after the above-mentioned inkjet printing, to obtain a formed product in the shape of a TV animation character with a minor axis of 20 mm, a major axis of 30 mm, and a curved cutting part with a radius of 1 mm.

[0295] Apparatus: "MERCURY609" manufactured by SEI Corporation,

[0296] Temperature: Room temperature (20 - 30 °C),

[0297] Laser type: Carbon dioxide laser,

[0298] Laser output power: 200 W,

[0299] Cutting speed: 350 - 400 cm / minute.

[0300] [Evaluation results]

[0301] The evaluation results are shown in Tables 3 - 7.

[0302]

[0303]

[0304]

[0305]

[0306]

[0307] In Examples (E1-V) to (E9-V), only virgin materials were used as the materials for the base layer and the surface layer. In these examples, as the styrenic copolymer (S), 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.

[0308] In these examples, a laminated sheet was produced in which a base layer containing a methacrylic resin (M) and surface layers containing a styrenic copolymer (S) located on both sides thereof were laminated, and the ratio of the total thickness of the surface layers to the total thickness of the laminated sheet was 1 to 20%.

[0309] The laminated sheets obtained in these examples had good ink adhesion and laser cutting processability, a haze value of 1% or less, and good transparency.

[0310] The styrenic copolymer (S) used in these examples had good compatibility with the methacrylic resin (M), and the haze values of the 3.0-mm thick single-layer molded sheets of the pulverized products of the obtained laminated sheets were all 1% or less, and the transparency was good. In these examples, laminated sheets that can be used as recycled materials and have excellent sustainability can be obtained.

[0311] In Examples (E1-1) to (E1-3), 30 to 100% by mass of all the raw materials of the base layer were replaced with recycled materials composed of the pulverized products of the laminated sheets obtained in Example (E1-V), and the same operations as in Example (E1-V) were performed to obtain laminated sheets. The obtained laminated sheets had good ink adhesion and laser cutting processability, a haze value of 1% or less, and good transparency. Even when a large amount of recycled materials were used, high-quality laminated sheets could be obtained in the same manner as in the examples using only virgin materials. In these examples, laminated sheets containing recycled materials and having excellent sustainability can be obtained.

[0312] In the other examples shown in Tables 4 and 5, the same results were also obtained.

[0313] The styrenic copolymers (S) used in the examples shown in Tables 3 to 5 were all styrenic copolymers (SX) in which the ratio of the triad sequence (SSS) was 0 to 40 mol% and the ratio of the triad sequence (XSX) was 5 to 34 mol%.

[0314] In the examples shown in Tables 3 to 5, the acrylonitrile-styrene copolymer (AS) used is an acrylonitrile-styrene copolymer (AS-E) in which the ratio of the copolymer having a composition with an elution time of 9 minutes or less is 0 to 5% by mass, the ratio of the copolymer having a composition with an elution time of 23 minutes or more is 0 to 5% by mass, and the elution time at the peak top of the maximum peak in the chromatogram is 9 to 23 minutes when gradient high performance liquid chromatography (gradient HPLC) analysis is carried out using two liquids, n-hexane and chloroform, as the eluent.

[0315] The compatibility of the styrene copolymer (S) and the methacrylic resin (M) used in the examples shown in Tables 4 and 5 is good. Therefore, it was confirmed that the base material layer of the laminated sheet obtained in these examples has a completely compatible structure of the styrene copolymer (S) and the methacrylic resin (M) in the transmission electron microscope image (TEM image).

[0316] In Comparative Examples (EC10-V) to (EC12-V), (EC16-V), and (EC17-V), only virgin materials were used as the materials for the base material layer and the surface layer. In these examples, the compatibility of the styrene copolymer (S) and the methacrylic resin (M) is poor, and the haze values of the 3.0 mm thick single-layer molded sheets of the crushed products of the obtained laminated sheets are all significantly as high as 17 to 100%, and the transparency is significantly poor. In these examples, laminated sheets that can be used as recycled materials and have excellent sustainability were not obtained.

[0317] In Comparative Example (EC10-1), 30% by mass of all the raw materials of the base material layer was replaced with recycled material composed of the crushed product of the laminated sheet obtained in Comparative Example (EC10-V), and the operation was carried out in the same manner as in Comparative Example (EC10-V) to obtain a laminated sheet. The haze value of the obtained laminated sheet is significantly high and the transparency is significantly poor. In this comparative example, a laminated sheet that has excellent transparency even when containing recycled material and has excellent sustainability was not obtained.

[0318] The same results were also obtained in Comparative Examples (EC11-1), (EC12-1), (EC16-1) to (EC16-3), and (EC17-1) to (EC17-3).

[0319] The compatibility of the styrene copolymer (S) and the methacrylic resin (M) used in Comparative Examples (EC10-1), (EC11-1), (EC12-1), (EC16-1) to (EC16-3), and (EC17-1) to (EC17-3) was all poor. Therefore, the base material layer of the laminated sheet obtained in these comparative examples 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.

[0320] An example of an electron microscope image of a sea-island structure in which the maximum diameter of a plurality of particulate island phases exceeds 50 nm is shown in Figure 4 . Figure 4 It is a transmission electron microscope image (TEM image) showing the phase structure (sea-island structure) of the base material layer contained in the laminated sheet obtained in Comparative Example (EC16-3). In each island phase in this TEM image, it contains an acrylonitrile-styrene copolymer (AS5) and a methacrylic resin (PMMA1) that is slightly compatible with it.

[0321] The ink adhesion of the single-layer sheet made of the styrene copolymer (S) in Comparative Example (EC13-V) was good, but due to the high content of styrene monomer units in the laminated sheet, the laser cutting processability was poor.

[0322] The laser cutting processability of the single-layer sheet made of the methacrylic resin (M) that does not have an aromatic ring structure in the molecule in Comparative Example (EC14-V) was good, but due to the absence of a surface layer containing the styrene copolymer (S), the ink adhesion was poor.

[0323] In Comparative Examples (EC15-V) and (EC15-1), the laminated sheets obtained with the ratio of the total thickness of the surface layer to the total thickness of the laminated sheet exceeding 20% had good ink adhesion, but due to the high content of styrene monomer units in the laminated sheet, the laser cutting processability was poor.

[0324] The present invention is not limited to the above-described embodiments and examples, and appropriate design changes can be made as long as the gist of the present invention is not deviated from.

[0325] This application claims priority based on Japanese Patent Application No. 2022-205089 filed on December 22, 2022, Japanese Patent Application No. 2023-084294 filed on May 23, 2023, Japanese Patent Application No. 2023-129664 filed on August 9, 2023, and Japanese Patent Application No. 2023-191424 filed on November 9, 2023, and incorporates the entire contents disclosed therein into this specification.

[0326] Symbol Explanation

[0327] 1 Laminated Sheet

[0328] 11 Base Material Layer

[0329] 21, 22 Surface Layers

Claims

1. A laminated sheet which is a laminated sheet having a base material layer and a surface layer laminated on at least one surface of the base material layer, wherein, the base material layer contains a methacrylic resin (M) containing 80 to 100% by mass of methyl methacrylate units, the surface layer contains a styrenic copolymer (S), the ratio of the total thickness of the surface layer to the total thickness of the laminated sheet is 1 to 20%, the haze value of a 3.0 mm thick single-layer formed sheet of the pulverized product of the laminated sheet is 4% or less.

2. The laminated sheet according to claim 1, wherein, The styrenic copolymer (S) is one or more styrenic 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 laminated sheet according to claim 1, wherein, The content of styrenic monomer units in the laminated sheet is 0.1 to 25% by mass.

4. The laminated sheet according to claim 1, wherein, the styrenic copolymer (S) contains a styrenic copolymer (SX) which is a binary copolymer of styrenic monomer units (S) and other monomer units (X), For a styrene copolymer (SX), when the ratios of the triad sequences of styrenic monomer unit (S)-styrenic monomer unit (S)-styrenic monomer unit (S) (SSS), the triad sequence of other monomer unit (X)-styrenic monomer unit (S)-styrenic monomer unit (S) (XSS), and the triad sequence of other monomer unit (X)-styrenic monomer unit (S)-other monomer unit (X) (XSX) are determined from the 13 C-NMR spectrum measured under the condition of the inverse gated decoupling method, the ratio of the triad sequence (SSS) is 0 to 40 mol%, and the ratio of the triad sequence (XSX) is 5 to 34 mol% with respect to a total of 100 mol% of the triad sequences (SSS), (XSS), and (XSX).​​ 5. The laminated sheet according to claim 1, wherein, the styrenic copolymer (S) contains an acrylonitrile-styrene copolymer (AS-E), and when gradient high performance liquid chromatography analysis is carried out under the following conditions using two liquids, n-hexane and chloroform, as eluents, the ratio of the copolymer having a composition with an elution time of 9 minutes or less is 0 to 5% by mass, the ratio of the copolymer having a composition with an elution time of 23 minutes or more is 0 to 5% by mass, and the elution time at the peak top of the maximum peak in the chromatogram is 9 to 23 minutes, <Conditions for gradient high performance liquid chromatography analysis> As the column, a silica gel column having an inner diameter of 4.6 mmφ and a length of 25 cm filled with spherical all-porous silica gel having a particle size of 5 μm is used, the column temperature is set to 40°C, chloroform is used as the solvent, and a sample solution with a concentration of 0.5 mg / mL is prepared, When the time from the start of analysis is set as T (minutes), the gradient curve of the mobile phase is as follows, the mobile phase from T = 0 to T = 5 is a n-hexane / chloroform mixed solution (50 vol% / 50 vol%), the chloroform concentration in the mobile phase is increased at a constant rate from 50 vol% to 100 vol% from T = 5 to T = 20, the mobile phase from T = 20 to T = 25 is 100 vol% chloroform, the flow rate of the mobile phase is 0.8 mL / minute, as the detector, an absorbance detector with a detection wavelength of 260 nm is used.

6. The laminated sheet according to claim 1, wherein, The base material layer contains a methacrylic resin composition (MR) containing a methacrylic resin (M) and a styrenic copolymer (S).

7. The laminated sheet according to claim 6, wherein, The base material layer has a completely compatible structure of a styrene copolymer (S) and a methacrylic resin (M), or has an island structure in which a plurality of particulate island phases containing a styrene copolymer (S) are dispersed in a sea phase containing a methacrylic resin (M), and the maximum diameter of the plurality of particulate island phases is greater than 0 nm and 50 nm or less.

8. The laminated sheet according to claim 6, wherein, The content of the styrene monomer units in the base material layer is 0.5 to 10.0% by mass.

9. The laminated sheet according to claim 6, wherein, At least a part of all the raw materials of the base material layer is a recycled resin composition (R) composed of pulverized materials of the previously manufactured laminated sheet or processed products of the pulverized materials.

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

11. The laminated sheet according to claim 1, which is used for inkjet printing and / or laser cutting.

12. The laminated sheet according to claim 1, which is a co-extrusion molded sheet.

13. A printed matter, which is a printed matter obtained by inkjet printing the surface layer of the laminated sheet according to any one of claims 1 to 12.

14. A molded article, which is a molded article obtained by inkjet printing and laser cutting the laminated sheet according to any one of claims 1 to 12.

15. The method for manufacturing the laminated sheet according to claim 6, wherein, The laminated sheet is co-extrusion molded using, as at least a part of all the raw materials of the base material layer, a recycled resin composition (R) composed of pulverized materials of the previously manufactured laminated sheet or processed products of the pulverized materials.

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