Multilayer sheet and film, and decorative molded products using the same

Abstract

According to the present invention, it is possible to provide a multilayer sheet or multilayer film composed of a laminate that has a polycarbonate-based resin layer as a substrate and that moreover has a silicon-dioxide-particle-containing thermoplastic acrylic-based resin layer on one or both outermost surfaces of the substrate, wherein the average particle diameter of the silicon dioxide particles is 0.1-2 μm, and the silicon dioxide particle content is greater than 1 mass% and no greater than 10 mass% relative to the entirety of the thermoplastic acrylic-based resin layer.

Description

[Technical Field]

[0001] The present invention relates to a multilayer sheet and a multilayer film comprising a polycarbonate resin layer and a thermoplastic acrylic resin layer containing silicon dioxide particles having a specific average particle size in a specific proportion laminated on at least one surface of the polycarbonate resin layer. [Background technology]

[0002] Polycarbonate resin-based sheets and films are widely used as structural materials, replacing glass, due to their light weight, transparency, heat resistance, and impact resistance. Recently, they have also been used as decorative films due to their ease of printing and heat transfer. They are widely used in a variety of applications, including automotive applications such as heat controller panels, car navigation touch panels, instrument covers, glazing, and lamp lenses; office equipment and electrical and electronic applications such as housings and display panel fronts for mobile phones and mobile terminals, and shatterproof films for glass components; building materials such as greenhouse coverings, arcades, and lighting roofing; road materials such as sidewalk wainscoting and highway fences; and industrial materials such as nameplates. However, their applications have been limited due to their insufficient scratch resistance.

[0003] Meanwhile, in order to improve the scratch resistance of polycarbonate, a decorative film in which a thermoplastic acrylic resin layer is laminated onto a polycarbonate resin layer is disclosed in Patent Document 1. However, although this method achieves pencil hardness comparable to that of thermoplastic acrylic resin because a thermoplastic acrylic resin is laminated, it is not possible to sufficiently improve scratch resistance (steel wool hardness) when dust or sand accumulates on the molded product and is wiped off.

[0004] Patent Document 2 discloses a laminate in which a sheet in which a thermoplastic acrylic resin layer is laminated onto a polycarbonate resin layer is placed in the mold of an injection molding machine, and polycarbonate resin is injected into the mold to form a molded article, and then a coating composition containing colloidal silica with a particle size of 10 to 20 nm is applied to the surface of the molded article, followed by thermal curing. However, although this method improves scratch resistance, applying the coating composition to a molded article with a curved surface after molding tends to result in poor appearance such as dust adhesion and uneven coating, and therefore poor productivity. Furthermore, there was a problem that the application of the coating composition increased the haze. Although productivity would be improved if the coating composition were applied to the laminated sheet before injection molding, there was a drawback in that the coating composition had poor thermoplasticity and was brittle, so cracks were likely to occur on the coating surface during the molding process, and the shapes that could be molded were limited to those with large curvatures. Patent Document 2 states that the average particle size of silica (silicon dioxide) in colloidal silica is preferably 4 to 20 nm, and that the silica content is preferably 50 to 200 parts by weight relative to the organoalkoxysilane that is a component of the coating. As an example, it gives an example of a laminate with a haze of 0.7% or more, but the haze value was not at a satisfactory level.

[0005] On the other hand, Patent Document 3 discloses a sheet in which a thermoplastic acrylic resin layer containing silicon dioxide particles is laminated to a polycarbonate resin layer, but further improvements in scratch resistance and impact resistance are desired. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-156197 [Patent Document 2] JP 2006-35519 A [Patent Document 3] Patent No. 6495173 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a multilayer sheet and a multilayer film that have both high transparency and scratch resistance and that are easy to print and heat-form. [Means for solving the problem]

[0008] As a result of extensive research into solving the above problems, the inventors have found that by laminating a thermoplastic acrylic resin layer containing a specific proportion of silicon dioxide particles having a specific average particle size onto a polycarbonate resin layer, it is possible to provide a multilayer sheet and a multilayer film that have high transparency and scratch resistance and are easy to print and heat-form.

[0009] That is, the present invention is as follows: <1> A multilayer sheet or a multilayer film comprising a laminate having a polycarbonate-based resin layer as a substrate and a thermoplastic acrylic-based resin layer containing silicon dioxide particles as an outermost layer on one side or on both sides of the substrate, In the multilayer sheet or multilayer film, the silicon dioxide particles have an average particle size of 0.1 to 2 μm, and the content of the silicon dioxide particles is more than 1 mass % and 10 mass % or less relative to the total amount of the thermoplastic acrylic resin layer. <2> The total light transmittance is 85% or more and less than 93%, and the haze is 0.01% or more and less than 0.7%. <1> The multilayer sheet or multilayer film is as described above. <3> The haze of the laminate is 0.01% or more and less than 1.5% after the surface of the thermoplastic acrylic resin layer of the laminate is scratched by attaching #0000 steel wool to a 33 mm x 33 mm square pad and moving it back and forth 15 times under a load of 1000 g. <1> or <2> The multilayer sheet or multilayer film is as described above. <4> The average thickness of the entire laminate is 0.03 to 2 mm, and the average thickness of the thermoplastic acrylic resin layer is 1 μm or more and less than 10 μm. <1> from <3> The multilayer sheet or multilayer film according to any one of the preceding items. <5> the above <1> from <4> 1. A decorated molded article using the multilayer film or multilayer sheet according to any one of the preceding items as the outermost layer. <6> the above <1> from <4> A method for producing the multilayer film or multilayer sheet according to any one of the above, This manufacturing method is characterized in that when forming the laminate, a feed block method is used in which the ratio of the feed block stacking width to the die effective lip length (feed block stacking width (mm) / die effective lip length (mm)) is in the range of 0.03 to 0.7. [Effects of the Invention]

[0010] The multilayer sheet and multilayer film of the present invention can achieve both high transparency and scratch resistance by using a thermoplastic acrylic resin layer containing a specific proportion of silicon dioxide having a specific average particle size. Furthermore, compared to sheets having a hard coat layer with poor thermoplasticity on the surface, the multilayer sheet and multilayer film have good heat-shapeability, are less likely to crack during shaping, and are also highly productive. Furthermore, by laminating the above-mentioned thermoplastic acrylic resin layer thinly, good film strength can be imparted in addition to the above properties. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. The polycarbonate resin constituting the polycarbonate resin layer in the present invention may be one obtained by interfacial polymerization using an aromatic dihydroxy compound or a small amount of a polyhydroxy compound and phosgene, or an optionally branched thermoplastic polycarbonate polymer obtained by transesterification of an aromatic dihydroxy compound with a diester of carbonic acid. In particular, carbonate polymers made mainly from bisphenol A obtained by interfacial polymerization are most preferable in terms of thermal stability and moldability. The molecular weight of the polycarbonate resin used is preferably 20,000 to 28,000, more preferably 21,000 to 28,000, in terms of viscosity average molecular weight. If the viscosity average molecular weight is less than 20,000, a decrease in impact resistance may be observed. If the viscosity average molecular weight exceeds 28,000, a decrease in moldability may occur. Other resins and various additives may be added to the polycarbonate resin within a range that maintains its transparency and moldability. Examples of additives include ultraviolet absorbers, antioxidants, color inhibitors, flame retardants, mold release agents, antistatic agents, and dyes and pigments. In particular, the thickness of the multilayer sheet and multilayer film of the present invention is usually 0.03 mm to 2.0 mm, preferably 0.1 mm to 1.0 mm, taking into consideration the shapeability. If it is too thin, it will be prone to cracking, and if it is too thick, the shapeability will decrease.

[0012] The thermoplastic acrylic resin layer in the present invention is mainly made of a thermoplastic acrylic resin and contains silicon dioxide particles. (1) Thermoplastic acrylic resin The thermoplastic acrylic resin constituting the thermoplastic acrylic resin layer in the present invention is a copolymer of methyl methacrylate and an acrylic acid ester such as methyl acrylate, ethyl acrylate, or butyl acrylate. The copolymer composition and molecular weight can be appropriately selected depending on the coextrusion conditions. The copolymer composition ratio is preferably 80 to 99% methyl methacrylate and 1 to 20% acrylic acid ester such as methyl, ethyl, or butyl acrylate, but is not limited to these. The molecular weight is preferably 30,000 to 300,000 in weight average molecular weight, but is not limited to these. A higher deflection temperature under load of the thermoplastic acrylic resin also increases the glass transition temperature, and the roll transfer temperature approaches that of the polycarbonate resin, resulting in a laminate with excellent roll transferability and appearance. Therefore, the deflection temperature under load of the thermoplastic acrylic resin is preferably 90°C or higher, more preferably 95°C or higher, and even more preferably 100°C or higher.

[0013] To impart impact resistance, a rubber-like polymer and / or rubber particles may be added to the thermoplastic acrylic resin, provided that the added polymer and / or rubber particles do not significantly reduce transparency or surface hardness. In this case, the Rockwell hardness (M scale) of the thermoplastic acrylic resin composition to which the polymer and / or rubber particles are added is preferably 30 or greater. If the Rockwell hardness is less than 30, transparency will decrease, and when used as a housing, haze will cause poor appearance of printing on the back surface, and the required surface hardness may not be achieved.

[0014] Furthermore, other resins and various additives may be added to the thermoplastic acrylic resin within the range that maintains its transparency and shaping ability, and examples of the additives include ultraviolet absorbers, antioxidants, coloring inhibitors, flame retardants, mold release agents, antistatic agents, dyes and pigments, etc. In order to prevent ultraviolet degradation of the polycarbonate resin layer and the thermoplastic acrylic resin layer in the present invention, it is particularly preferable to add ultraviolet absorbers.

[0015] Examples of usable ultraviolet absorbers include benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, benzoxazine-based, malonic acid ester-based, triazine-based, and polymer-type ultraviolet absorbers to which these are added as pendants. Benzotriazole-based UV absorbers include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2,2-methylenebis[4-(1,1,3,3-tetramethylenebutyl)-6-(2H-benzotriazol-2-yl)phenol], and 2-(2H-benzotriazole-2 Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, and 2,2-dihydroxy-4,4'-dimethoxybenzophenone. Examples of salicylic acid phenyl ester-based ultraviolet absorbers include pt-butylphenyl salicylic acid ester, etc. Examples of benzoxazine-based ultraviolet absorbers include 2,2'-(1,4-phenylene)bis[4H-3,1-benzoxazin-4-one], etc.

[0016] Examples of malonic acid ester-based ultraviolet absorbers include dimethyl [(4-methoxyphenyl)-methylene]malonate. Examples of triazine-based ultraviolet absorbers include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine. triazine, 2,6-di(4-biphenyl)-4-(2-hydroxy-4-(2-ethylhexyl)oxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxy)-1,3,5-triazine, and the like can be mentioned, but are not limited to these, and commonly available ultraviolet absorbers can be included.

[0017] Polymer-type UV absorbers have a hydroxybenzophenone or hydroxybenzotriazole structure in the molecule, and some of these have alkyl groups substituted for the hydrogen atoms. One example of a polymer-type UV absorber is UVA-633L (2-hydroxy-4-(methacryloyloxyethoxy)benzophenone) methyl methacrylate copolymer, which is commercially available from BASF.

[0018] Commercially available thermoplastic acrylic resins suitable for the present invention include Parapet H R-1000L manufactured by Kuraray Co., Ltd., ALTUGLAS V020 manufactured by Arkema, and IRG304 manufactured by Mitsubishi Rayon Co., Ltd.

[0019] The average thickness of the thermoplastic acrylic resin layer in the present invention is preferably 1 μm or more and 55 μm or less, more preferably 1 μm or more and 40 μm or less, even more preferably 1 μm or more and less than 10 μm, and particularly preferably 1 μm or more and 9 μm or less. By reducing the average thickness of the thermoplastic acrylic resin layer, the transparency and strength of the laminate can be significantly improved. On the other hand, the pencil hardness may decrease. However, this decrease in pencil hardness can be compensated for by providing, for example, a thermoplastic acrylic resin layer that does not contain silicon dioxide between the thermoplastic acrylic resin layer in the present invention and the polycarbonate resin layer.

[0020] (2) Silicon dioxide particles The silicon dioxide particles constituting the thermoplastic acrylic resin layer in the present invention preferably have an average particle size of 0.1 to 2 μm, and more preferably 0.2 to 0.6 μm. If the average particle size is small, the scratch resistance effect is insufficient, and if it is large, point defects in the multilayer sheet and multilayer film increase. The content of the silicon dioxide particles is more than 1% by mass and not more than 10% by mass, preferably more than 1% by mass and not more than 5% by mass, and most preferably 1.5 to 3.0% by mass, based on the entire thermoplastic acrylic resin layer. If the content of the silicon dioxide particles is low, sufficient scratch resistance cannot be obtained, and if it is high, the haze of the multilayer sheet and multilayer film increases. There are no particular limitations on the method for producing silicon dioxide particles, and they can be produced by known methods such as the VMC method, wet synthesis method, and melting method. In particular, the VMC method is preferred when considering the uniformity of the silicon dioxide particle size. The VMC method is a method in which silicon dioxide powder is introduced into an oxygen stream to oxidize it, and the resulting reaction heat is used to obtain fine spherical silicon dioxide particles. Commercially available silicon dioxide particles include ADMAFINE SO-C1, ADMAFINE SO-C2, ADMAFINE SO-C4, ADMAFINE SO-C5, and ADMAFINE SC110G-SQ manufactured by Admatechs Co., Ltd., which can be selected and used alone or in combination as appropriate. In particular, ADMAFINE SC110G-SQ, which has large particles of 10 μm or more contained in the product reduced to 100 ppm or less, produces very few point defects when laminates are formed by extrusion molding, which is excellent.

[0021] The silicon dioxide particles contained in the thermoplastic acrylic resin layer of the present invention can be identified by the following method. The presence of silicon dioxide particles can be confirmed by observing the surface or cross-section of the molded body using surface observation equipment such as TEM and FE-SEM. These measurements make it possible to confirm the dispersion state of the particles and the state of bleeding out to the surface. Furthermore, the silicon dioxide particles can also be identified by simultaneously using surface elemental analysis equipment such as EDX, XPS, and EPMA.

[0022] The average particle size and content of the silicon dioxide particles contained in the thermoplastic acrylic resin layer in the present invention can be measured by the following method. As pretreatment, test pieces and sample solutions can be prepared by the following methods: The sample solution can be prepared by embedding the molded product in epoxy resin, cutting out only the acrylic resin layer from the embedded molded product using a surface cutting device such as an ultramicrotome, and dissolving it in a good solvent (dichloromethane, THF, etc.), or by punching out a certain area of ​​the molded product and dissolving the punched piece in a good solvent (dichloromethane, THF, etc.).

[0023] The content of silicon dioxide particles can be measured using the following method. First, a solution in which Si particles of known concentration have been dispersed is impregnated into filter paper and then dried. X-ray fluorescence measurement is carried out at three levels of concentration to be used as a calibration curve. Next, the above-mentioned sample solution, which has been pretreated and dissolved, is dropped onto filter paper, which is then dried. The dried filter paper is then similarly measured using an X-ray fluorescence measurement device, allowing the Si element to be quantified. The particle size can be measured by using a particle size measuring device manufactured using the principles of laser diffraction or dynamic light scattering to measure the prepared solution.

[0024] Methods for forming the thermoplastic acrylic resin layer on at least one side of the polycarbonate resin layer include co-extruding the thermoplastic acrylic resin layer and the polycarbonate resin layer, heat-laminating a thermoplastic acrylic resin film on the surface of the extruded polycarbonate, and applying a solution of silicon dioxide particles dispersed in a thermoplastic acrylic resin solution to a polycarbonate substrate and drying it. Co-extrusion is particularly preferred because it allows a multilayer film to be obtained in a single step, allows flexibility in the thickness ratio of each layer, and can achieve both sufficient scratch resistance and high transparency. When using heat lamination, it is preferable to use an extrusion-molded thermoplastic acrylic resin film. For example, heat laminating a film obtained by injection molding may result in insufficient scratch resistance. Furthermore, in order to obtain sufficient scratch resistance from multilayer sheets and films obtained by applying a solution in which silicon dioxide particles are dispersed in a thermoplastic acrylic resin solution onto a polycarbonate substrate and drying it, it is necessary to contain a large amount of silicon dioxide particles, which may result in a loss of transparency.

[0025] A specific example of the coextrusion method most suitable for producing the multilayer sheet and multilayer film of the present invention as described above will be described below. The extrusion device used in the production generally comprises a main extruder that extrudes the polycarbonate resin that constitutes the substrate layer and a sub-extruder that extrudes the thermoplastic acrylic resin that constitutes the coating layer, and the sub-extruder is usually smaller than the main extruder. The temperature condition of the extruder that extrudes the polycarbonate resin is usually 230 to 300°C, preferably 240 to 290°C, and the temperature condition of the extruder that extrudes the thermoplastic acrylic resin is usually 200 to 270°C, preferably 220 to 260°C.

[0026] Common coextrusion lamination methods include the feedblock method, in which the laminate joined in a feedblock is stretched and molded inside a T-die, and the multi-manifold method, in which each layer is spread in each manifold inside the die and joined near the lip outlet.However, the feedblock method is preferred in the present invention. In the feedblock method, the ratio of the feedblock lamination width to the die effective lip length is particularly important, and a range of 0.03 to 0.7 is preferred for the feedblock lamination width (mm) / die effective lip length (mm). Furthermore, a range of 0.05 to 0.2 is most preferred for the feedblock lamination width (mm) / die effective lip length (mm). If the feedblock lamination width (mm) / die effective lip length (mm) ratio is too large or too small, streak-like defects tend to occur in the laminate. The multi-manifold method, in which the lamination width and effective lip length are equal, is a lamination method that is disadvantageous for forming the laminate of the present invention with a high appearance, as it tends to cause streak-like defects in the film.

[0027] The die temperature is typically 230 to 340°C, preferably 260 to 320°C. If the die temperature is too high or too low, the desired scratch resistance may not be achieved. The laminated resin is then poured into a molding roll with a mirror-finished or molded surface to form a laminate. The laminate is cooled while passing through the molding roll, forming a laminate. Cooling methods include a film method in which the laminate is clamped between No. 1 and No. 2 rolls at low pressure and then passed around No. 3 roll to form a laminate. Alternatively, a sheet method (bank method) is used in which the laminate is clamped between No. 1 and No. 2 rolls at high pressure to form a bank (a resin pool), then further clamped between No. 2 and No. 3 rolls at high pressure, and then peeled from No. 3 roll with a take-up roll. Since the transparency and scratch resistance of the laminate are not affected by either cooling method, the cooling method can be appropriately selected depending on the desired thickness and physical properties.

[0028] When the multilayer sheet and multilayer film of the present invention are used for transparent applications, the total light transmittance is preferably 85% or more and less than 93%, more preferably 90% or more and less than 93%, and the haze of the multilayer sheet and multilayer film of the present invention is preferably 0.01% or more and less than 0.7%, more preferably 0.01% or more and less than 0.5%. The scratch resistance of the multilayer sheet and multilayer film of the present invention can be evaluated by the steel wool hardness test described below. A 33mm x 33mm square pad of #0000 steel wool manufactured by Nippon Steel Wool Co., Ltd. was attached to the surface of the thermoplastic acrylic resin layer of the laminate held on a table, and the pad was then rubbed 15 times back and forth under a load of 1000g. The rubbed surface was then washed with ethanol and the haze was measured. The haze after this rub resistance test (steel wool hardness test) is preferably 0.01% or more and less than 15%, more preferably 0.01% or more and less than 10%, and most preferably 0.01% or more and less than 1.5%. When a laminate having a large haze after the steel wool hardness test is used as a decorative film or decorative sheet as described below, scratches are generated in daily use, which undesirably deteriorates the appearance of the molded product.

[0029] The laminate of the present invention is preferably used as a decorative film or decorative sheet. In consideration of transparency and scratch resistance after commercialization, a laminate in which a silicon dioxide-containing thermoplastic acrylic resin layer is formed on one side of a polycarbonate-based resin layer is preferably used. Examples of decoration methods include a method of directly printing various designs on the polycarbonate-based resin layer surface by continuous gravure printing, silk printing, screen printing, etc., a method of transferring a transfer foil, a method of applying a metal plating-like decoration by vapor deposition or sputtering, or a method of laminating another resin film that has been decorated by printing or vapor deposition, etc.

[0030] The decorative film and decorative sheet can also be used by laminating a thermoplastic resin sheet to protect the decorative surface. Examples of resins that make up the thermoplastic resin sheet include polycarbonate resins, thermoplastic acrylic resins, ABS resins, polyvinyl chloride resins, polyurethane resins, polyester resins, polyolefin resins, and resin compositions obtained by kneading at least two or more of these resins.

[0031] The resulting decorative film or decorative sheet can be laminated onto a thermoplastic resin molded article so that the silicon dioxide-containing thermoplastic acrylic resin layer is positioned on the side requiring scratch resistance (usually the outer side), thereby obtaining a decorated molded article. Examples of resins that can be used to form the thermoplastic resin molded article include polycarbonate resin, thermoplastic acrylic resin, ABS resin, polyvinyl chloride resin, polyurethane resin, polyester resin, polyolefin resin, and resin compositions obtained by kneading at least two or more of these resins.

[0032] As a method for obtaining a decorated molded article, known molding methods such as in-mold molding, insert molding, injection molding and lamination can be used. Considering the appearance of the decorated molded article, in-mold molding and insert molding are particularly suitable as processing methods for the laminate of the present invention. In-mold molding is a method in which a decorative film or decorative sheet is preformed in an injection molding mold using vacuum forming, pressure forming, or the like, and then molten resin is injected into it to form an injection-molded product, and at the same time, the decorative film or decorative sheet is laminated to the molded product. The insert molding method is a method in which a decorative film or decorative sheet is preformed by vacuum forming, compressed air forming, or the like, then inserted into an injection molding mold, and molten resin is injected into it to form an injection-molded product, while at the same time laminating the decorative film or decorative sheet to the molded product.

[0033] The decorated molded article of the present invention uses, as its outermost layer, a multilayer film or sheet made of a laminate having excellent scratch resistance as described above, and therefore the decorated molded article of the present invention also has excellent scratch resistance. [Example]

[0034] Examples of the present invention will be described below, but the present invention is not limited to these. The evaluation and measurement methods used in the present examples are shown below. (1) Average particle size of silicon dioxide particles contained in the thermoplastic acrylic resin layer of the laminate Measurements were carried out using a particle size distribution analyzer, Nanotrac Wave Series EX250, manufactured by Nikkiso Co., Ltd. As a pretreatment, the molded product was punched out to a certain area (a circle with a diameter of 10 mm), and the punched piece was dissolved in THF (tetrahydrofuran). The solution was placed in the cell of the measuring device, and the average particle size of the silicon dioxide particles was measured. (2) The content of silicon dioxide particles contained in the thermoplastic acrylic resin layer of the laminate The Si content was determined using an X-ray fluorescence spectrometer. (3) Measurement of laminate thickness The thickness of the central portion of the laminate was measured 10 times with a micrometer, and the average value was taken as the thickness. (4) Measurement of layer thickness of laminate The central portion of the laminate was cut out, and the cross section was cut with a microtome. The thicknesses of the polycarbonate resin layer and the thermoplastic acrylic resin layer were measured using optical microscopes ME600 and DIGITALSIGHT manufactured by Nikon Corporation. (5) Steel wool hardness test A 33mm x 33mm square pad of #0000 steel wool manufactured by Nippon Steel Wool Co., Ltd. was attached to the surface of a sample held on a table, and the pad was placed on the surface and scratched by moving it back and forth 15 times under a load of 1000g. After washing the sample with ethanol, the total light transmittance and haze were measured. (6) Total light transmittance measurement The total light transmittance of the laminate was measured in accordance with JIS K7361-1 using a reflectance / transmittance meter HR-100 manufactured by Murakami Color Research Laboratory Co., Ltd. (7) Haze measurement The haze of the laminate was measured in accordance with JIS K7136 using a reflectance / transmittance meter HR-100 manufactured by Murakami Color Research Laboratory Co., Ltd. (8) Tensile test (yield stress / nominal breaking strain) The yield stress and nominal fracture strain were measured in accordance with JIS K7161 using a Strograph VE20 manufactured by Toyo Seiki Seisakusho Co., Ltd. (9) Drop test (breaking energy) The film was firmly fixed with a 5K-50 SUS F304 flange, and a bullet-shaped weight with a hemispherical tip with a curvature of 3 mmR was dropped onto the center of the film. The breaking energy was calculated using the following formula from the weight and height at which the film broke. Breaking energy (J) = weight of broken weight (kgf) x breaking height (m) x 9.8 (N / kgf) (10) Appearance The resulting laminate was visually inspected and compared with a laminate containing no silicon dioxide particles and having a good appearance.

[0035] Example 1 Polycarbonate resin layer material As the polycarbonate resin layer material, Iupilon S-3000R N114 manufactured by Mitsubishi Engineering Plastics Corporation was used. Preparation of thermoplastic acrylic resin layer material 95.55% by mass of ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema, 3.7% by mass of ADMAFINE SO-C1 (silicon dioxide having an average particle size of 0.20 μm) manufactured by Admatechs Co., Ltd., 0.14% by mass of RIKEMAL H-100 (lubricant) manufactured by Riken Vitamin Co., Ltd., 0.04% by mass of Adekastab PEP-36 (heat stabilizer) manufactured by ADEKA Corporation, 0.07% by mass of K-NOXBHT (heat stabilizer) manufactured by Kyodo Pharmaceutical Co., Ltd., and 0.5% by mass of Tinuvin 1600 (ultraviolet absorber) manufactured by BASF were quantitatively fed using a gravimetric quantitative feeder, and the mixture was kneaded and pelletized at 240°C using a twin-screw extruder TEM-26SS manufactured by Toshiba Machine Co., Ltd. Laminate molding The extruder for the polycarbonate resin layer (A) was a vented single-screw extruder with a screw diameter of 100 mm and an L / D ratio of 32. The cylinder temperature was set to 280 °C, and the screw rotation speed was adjusted to supply 236 kg / hr to the feedblock. The extruder for the thermoplastic acrylic resin layer (B) containing silicon dioxide particles, which forms the coating layer, was a vented single-screw extruder with a screw diameter of 50 mm and an L / D ratio of 32. The cylinder temperature was set to 240 °C, and the gear pump rotation speed was adjusted to supply 10 kg / hr to the feedblock. The screw rotation speed was automatically controlled so that the resin pressure at the gear pump inlet was 7.0 MPa. Two types of resins were simultaneously fed into the feedblock, which was set at 260 °C, and laminated to a width of 200 mm. The laminate was then spread into a film and extruded into a die with an effective lip length of 1650 mm, which was set at 280 °C. The film laminate extruded from the die was clamped between a No. 1 roll (300 mm diameter, 2000 mm width) and a No. 2 roll (450 mm diameter, 2000 mm width) at 0.25 MPa, and then passed around a No. 3 roll to form a film. The roll temperatures were set to 60°C for No. 1 roll, 120°C for No. 2 roll, and 140°C for No. 3 roll, and the roll speed was 10.9 m / s. The No. 1 roll was an SF roll manufactured by Chiba Kikai Kogyo Co., Ltd., consisting of a rubber roll with a rubber thickness of 5 mm and a rubber hardness of 80° covered with a mirror-polished metal sleeve. The No. 2 and No. 3 rolls were conventional rigid metal rolls with mirror-polished surfaces.

[0036] Analysis of the resulting laminate revealed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparation of the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0037] Example 2 A laminate was obtained in the same manner as in Example 1, except that in preparing the thermoplastic acrylic resin layer material, ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema was used at 96.85 mass %, and ADMAFINE SO-C1 (average particle size 0.20 μm) manufactured by Admatechs Co., Ltd. was used at 3.7 mass % instead of ADMAFINE SO-C1 (average particle size 0.31 μm) at 2.4 mass %. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparing the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0038] Example 3 A laminate was obtained in the same manner as in Example 1, except that in preparing the thermoplastic acrylic resin layer material, ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema was used at 98.15 mass %, and ADMAFINE SO-C1 (average particle size 0.20 μm) and ADMAFINE SO-C5 (average particle size 1.50 μm) manufactured by Admatechs Co., Ltd. were used at 3.7 mass %. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparing the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0039] Example 4 A laminate was obtained in the same manner as in Example 1, except that in preparing the thermoplastic acrylic resin layer material, 89.25 mass% of ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema, 3.7 mass% of ADMAFINE SO-C1 (average particle size 0.20 μm) manufactured by Admatechs Co., Ltd., and 10 mass% of ADMAFINE SO-C1 (average particle size 0.20 μm) were used, and the output rate of the polycarbonate resin layer (A) for molding the laminate was 241 kg / h and the output rate of the thermoplastic acrylic resin layer (B) was 3.3 kg / h. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those when the thermoplastic acrylic resin layer material was prepared. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0040] Example 5 A laminate was obtained in the same manner as in Example 2, except that the discharge amount of the polycarbonate-based resin layer (A) was 114 kg. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparation of the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0041] Example 6 A laminate was obtained in the same manner as in Example 2, except that in preparing the thermoplastic acrylic resin layer material, ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema was used at 96.847 mass % and 0.003 mass % of silicone oil KF-96 manufactured by Shin-Etsu Chemical Co., Ltd. was added. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparation of the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0042] Example 7 The polycarbonate-based resin layer material and the thermoplastic acrylic-based resin layer material were prepared in the same manner as in Example 2. Laminate molding The extruder for the polycarbonate resin layer (A) was a vented single-screw extruder with a screw diameter of 120 mm and an L / D ratio of 32. The cylinder temperature was set to 280 °C, and the screw rotation speed was adjusted to supply 305 kg / hr to the feed block. The extruder for the thermoplastic acrylic resin layer (B) containing silicon dioxide particles, which forms the coating layer, was a vented single-screw extruder with a screw diameter of 50 mm and an L / D ratio of 32. The cylinder temperature was set to 240 °C, and the gear pump rotation speed was adjusted to supply 1.5 kg / hr to the feed block. The screw rotation speed was automatically controlled so that the resin pressure at the gear pump inlet was 4.0 MPa. Two types of resins were simultaneously fed into the feed block, which was set at 260 °C, and laminated to a width of 200 mm. The laminate was then spread into a sheet and extruded into a die with an effective lip length of 1180 mm, which was set at 260 °C. The sheet laminate extruded from the die was pressed between the No. 1 roll (360 mm diameter, 1500 mm face length) and the No. 2 roll (360 mm diameter, 1500 mm face length) at 10 MPa to form a bank (resin puddle). The No. 2 roll and the No. 3 roll (360 mm diameter, 1500 mm face length) were then pressed between them at 10 MPa, and the sheet laminate was peeled off from the No. 3 roll by a take-up roll to form a resin. The roll temperatures were set to 130°C for the No. 1 roll, 140°C for the No. 2 roll, and 180°C for the No. 3 roll, and the roll speeds were 2.93 m / min for the No. 1 roll, 2.93 m / min for the No. 2 roll, 2.95 m / min for the No. 3 roll, and 3.26 m / min for the take-up roll. The No. 1, No. 2, and No. 3 rolls were all mirror-polished, conventional rigid metal rolls. The take-up roll was a rubber roll with a hardness of 60°.

[0043] Analysis of the resulting laminate revealed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparation of the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the layer thickness were measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0044] (Comparative Example 1) A laminate was obtained in the same manner as in Example 3, except that in preparing the thermoplastic acrylic resin layer material, ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema was used at 98.75 mass%, and ADMAFINE SO-C5 (average particle size 1.50 μm) manufactured by Admatechs Co., Ltd. was used at 1.1 mass% and 0.5 mass%. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparing the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0045] (Comparative Example 2) A laminate was obtained in the same manner as in Example 4, except that in preparing the thermoplastic acrylic resin layer material, 87.25 mass% of ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema and 10.0 mass% of ADMAFINE SO-C1 (average particle size 0.20 μm) manufactured by Admatechs Co., Ltd. were used, and 12.0 mass% of ADMAFINE SO-C1 (average particle size 0.20 μm) was used. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those in preparing the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0046] (Comparative Example 3) A laminate was obtained in the same manner as in Example 1, except that in preparing the thermoplastic acrylic resin layer material, ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema was used at 87.25 mass%, ADMAFINE SO-C1 (average particle size 0.20 μm) manufactured by Admatechs Co., Ltd. was used at 3.7 mass%, and ADMAFANANO YC100C (average particle size 0.09 μm) manufactured by Admatechs Co., Ltd. was used at 12.0 mass%. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparing the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0047] Comparative Example 4 A laminate was obtained in the same manner as in Example 1, except that in preparing the thermoplastic acrylic resin layer material, ALTUGLAS V020 (thermoplastic acrylic resin) manufactured by Arkema was used at 99.15 mass%, 3.7 mass% of ADMAFINE SO-C1 (average particle size 0.20 μm) was used, and 0.1 mass% of ADMAFINE SO-C6 (average particle size 2.10 μm) was used. Analysis of the obtained laminate showed that the average particle size and content of silicon dioxide contained in the thermoplastic acrylic resin layer were the same as those at the time of preparing the thermoplastic acrylic resin layer material. The thickness of the central part of the laminate and the thickness of each layer were also measured. The thickness measured with a micrometer and the sum of the thicknesses of each layer measured with an optical microscope were the same value. A steel wool test was performed on the surface of Layer (B) of this laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0048] [Table 1] The results of the Examples and Comparative Examples summarized in Table 1 reveal the following. First, in each of Comparative Examples 1 to 4, the content of silicon dioxide particles is 1 mass % or less or exceeds 10 mass %, or the average particle size of the silicon dioxide particles is less than 0.1 μm or exceeds 2 μm. In these Comparative Examples, it was confirmed that the haze value increased significantly after the scratch resistance test, and the appearance was poor. More specifically, in Comparative Example 1 (0.5% by mass), which had a low content of silicon dioxide particles, even when large-sized silicon dioxide particles were used, the haze after the steel wool test increased, confirming poor scratch resistance. In Comparative Example 2 (12% by mass), which had a high content of silicon dioxide particles, even when small-sized silicon dioxide particles were used and the acrylic resin layer thickness was made as thin as possible, the haze before the steel wool test was high, transparency was poor, and point defects were observed. Furthermore, in Comparative Example 3 (0.09 μm), which had a small particle size of silicon dioxide particles, the haze after the steel wool test was extremely high, confirming that no scratch resistance effect was exhibited. In Comparative Example 4 (2.1 μm), which had a large particle size of silicon dioxide particles, the haze after the steel wool test was high, transparency was poor, and point defects were observed.

[0049] In contrast, in Examples 1 to 7 of the present invention, unlike the above-mentioned comparative examples, an appropriate amount of silicon dioxide particles having an average particle size within an appropriate range is contained in the thermoplastic acrylic resin layer. As a result, it was confirmed that the increase in haze value was suppressed even after the scratch resistance test, the sheet (laminate) had excellent scratch resistance, and the appearance of the sheet and the decorated molded product was good. It was also confirmed that the scratch resistance was further improved by using silicon dioxide particles in combination with an appropriate amount of silicone oil.

Claims

1. A multilayer sheet or a multilayer film comprising a laminate having a polycarbonate-based resin layer as a substrate and a thermoplastic acrylic-based resin layer containing silicon dioxide particles as an outermost layer on one side or on both sides of the substrate, the silicon dioxide particles have an average particle size of 0.1 to 1.5 μm, and the content of the silicon dioxide particles is more than 1 mass % and 10 mass % or less with respect to the total amount of the thermoplastic acrylic resin layer; The above multilayer sheet or multilayer film, wherein the average thickness of the thermoplastic acrylic resin layer is 2 μm or more and less than 10 μm.

2. 2. The multilayer sheet or film according to claim 1, having a total light transmittance of 85% or more and less than 93%, and a haze of 0.01% or more and less than 0.7%.

3. 3. The multilayer sheet or multilayer film according to claim 1, wherein the surface of the thermoplastic acrylic resin layer of the laminate is scratched by 15 reciprocating strokes of #0000 steel wool attached to a 33 mm x 33 mm square pad under a load of 1000 g, and the haze after scratching is 0.01% or more and less than 1.5%.

4. 4. The multilayer sheet or film according to claim 1, wherein the average thickness of the entire laminate is 0.03 to 2 mm.

5. A decorated molded article using the multilayer film or multilayer sheet according to any one of claims 1 to 4 as an outermost layer.

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