Multilayer sheet and multilayer film, and decorated molded article using the same

Abstract

According to the present application, there is provided a multilayer sheet or film composed of a laminate having a polycarbonate-based resin layer as a base material, and a thermoplastic acrylic resin layer containing silica particles having an average particle diameter of 0.1 to 2 μm on the outermost layer of one side or both sides of the base material, the content of the silica particles being more than 1 mass% and 10 mass% or less relative to the total amount of the thermoplastic acrylic resin layer.

Description

Technical Field

[0001] The present invention relates to multilayer sheets and multilayer films obtained by laminating a thermoplastic acrylic resin layer containing silica particles of a specified average particle size in a specified proportion on at least one surface of a polycarbonate resin layer. Background Technology

[0002] Polycarbonate resin-based sheets and films are widely used as structural materials to replace glass due to their excellent lightweight, transparency, heat resistance, and impact resistance. Furthermore, their ease of printing and heat-forming has recently led to their use as decorative films. Applications include automotive (such as heat controller covers, car navigation touchscreens, instrument panel covers, car windows, and headlight lenses), OA / Electronic / Electronic / Electronic applications (such as housings and display panels for mobile phones and mobile terminals, and anti-splash films for glass components), building materials (such as greenhouse coverings, arcades, and skylight roofing materials), road construction materials (such as sidewalk guardrails and highway fencing), and industrial materials (such as signage). However, their applications are limited by insufficient scratch resistance.

[0003] On the other hand, in order to improve the scratch resistance of polycarbonate, Patent Document 1 discloses a decorative film in which a thermoplastic acrylic resin layer is laminated on a polycarbonate resin layer. However, since the thermoplastic acrylic resin is laminated in this method, a pencil hardness comparable to that of thermoplastic acrylic resin can be obtained, but the scratch resistance (steel wool hardness) when wiping away dust or sand accumulated on the molded article is not sufficiently improved.

[0004] Furthermore, Patent Document 2 discloses a laminated body formed by means of placing a sheet with a thermoplastic acrylic resin layer laminated on a polycarbonate resin layer into an injection molding machine mold, injecting polycarbonate resin into the mold, coating the surface of the resulting molded article with a coating composition containing silicone with a particle size of 10-20 nm, and then thermosetting it to form the laminate. However, although this method can improve scratch resistance, because the coating composition is applied to the molded article with curved surfaces, appearance defects such as dust adhesion or uneven coating are prone to occur, resulting in poor productivity.

[0005] Furthermore, there is a problem of increased haze due to the application of the coating composition. Assuming that the coating composition is applied to the laminate before injection molding, although the productivity is increased, the coating composition lacks thermoplasticity and is brittle, so cracks are easily generated on the coated surface during the molding process, resulting in the disadvantage that the shapes that can be molded are limited to those with large curvatures.

[0006] In Patent Document 2, the silica in the preferred silicone has an average particle size of 4 to 20 nm, and the silica content is preferably 50 to 200 parts by weight relative to the organic alkoxysilane component of the coating. In its examples, a laminate with a haze of 0.7% or more is shown, but the haze value does not reach a satisfactory level.

[0007] On the other hand, Patent Document 3 discloses a sheet with a thermoplastic acrylic resin layer containing silica particles laminated on a polycarbonate resin layer, but further improvements in scratch resistance and impact resistance are desired.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 7-156197

[0011] Patent Document 2: Japanese Patent Application Publication No. 2006-35519

[0012] Patent Document 3: Japanese Patent No. 6495173 Summary of the Invention

[0013] The technical problem that the invention aims to solve

[0014] To address the problems of the prior art, the present invention provides a multilayer sheet and multilayer film that combine high transparency and scratch resistance, and are easy to print and heat-form.

[0015] Technical means for solving technical problems

[0016] In order to solve the above problems, the inventors of this invention conducted in-depth research and found that by stacking a thermoplastic acrylic resin layer containing silica particles of a specified average particle size in a specified proportion on a polycarbonate resin layer, it is possible to provide multilayer sheets and multilayer films that have both high transparency and scratch resistance, and are easy to print and heat-form.

[0017] That is, the present invention is as follows.

[0018] <1> A multilayer sheet or multilayer film, which is composed of a laminate, wherein the laminate is based on a polycarbonate resin layer, and the outermost layer on one side or the outermost layer on both sides of the substrate has a thermoplastic acrylic resin layer containing silica particles, wherein the average particle size of the silica particles is 0.1 to 2 μm, and the content of the silica particles is more than 1% by mass and less than 10% by mass relative to the total amount of the thermoplastic acrylic resin layer.

[0019] <2> As described in <1> above, the multilayer sheet or multilayer film has 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%.

[0020] <3> As described in <1> or <2> above, the multilayer sheet or multilayer film, wherein,

[0021] #0000 steel wool was installed on a 33mm×33mm square pad. The pad was subjected to a 1000g load and was moved back and forth 15 times on the surface of the thermoplastic acrylic resin layer of the above-mentioned laminate. The haze of the surface after abrasion was 0.01% or more and less than 1.5%.

[0022] <4> The multilayer sheet or multilayer film as described in any one of <1> to <3> above, wherein the average thickness of the entire stack is 0.03 to 2 mm, and the average thickness of the thermoplastic acrylic resin layer is more than 1 μm and less than 10 μm.

[0023] <5> A decorative molded article whose outermost layer uses any one of the above <1> to <4> multilayer sheets or multilayer films.

[0024] <6> A method for manufacturing a multilayer film or multilayer sheet according to any one of <1> to <4> above, wherein when forming the stacked body, a flow splitting method is used in which the ratio of the stack width of the feed block to the effective die lip length of the mold (the stack width of the feed block (mm) / the effective die lip length (mm)) is set to the range of 0.03 to 0.7.

[0025] Invention Effects

[0026] The multilayer sheets and films of the present invention utilize a thermoplastic acrylic resin layer containing silica of a specified particle size in a specified proportion, thus achieving both high transparency and scratch resistance. Furthermore, compared to sheets with a hard coating lacking thermoplasticity, they exhibit better heat-forming properties, are less prone to cracking during forming, and have higher productivity. Moreover, by laminating thin layers of the aforementioned thermoplastic acrylic resin, in addition to the above-mentioned characteristics, good film strength is also achieved. Detailed Implementation

[0027] The present invention will now be described in detail.

[0028] As the polycarbonate resin constituting the polycarbonate resin layer of the present invention, a polycarbonate resin obtained by interfacial polymerization of an aromatic dihydroxy compound or a small amount of a polyhydroxy compound with a carbonyl chloride can be used, or a branched thermoplastic polycarbonate polymer obtained by transesterification reaction of an aromatic dihydroxy compound with a diester can be used.

[0029] In particular, carbonate polymers with bisphenol A as the main raw material obtained by interfacial polymerization are the most preferred from the viewpoints of thermal stability and excipient properties.

[0030] The molecular weight of the polycarbonate resin used, measured in terms of viscosity-average molecular weight, is preferably 20,000 to 28,000, more preferably 21,000 to 28,000. When the viscosity-average molecular weight is below 20,000, a decrease in impact resistance is sometimes observed. When the viscosity-average molecular weight exceeds 28,000, a decrease in shapeability may sometimes occur. Within a range that maintains its transparency and shapeability, other resins or various additives can be added to the polycarbonate resin. Examples of additives include, for instance, UV absorbers, antioxidants, anti-coloring agents, flame retardants, mold release agents, antistatic agents, dyes, and pigments.

[0031] Specifically, regarding the thickness of the multilayer sheets and multilayer films of the present invention, considering the shapeability, it is typically 0.03 mm to 2.0 mm, preferably 0.1 mm to 1.0 mm. If the multilayer sheets and multilayer films are too thin, they are prone to cracking; if they are too thick, the shapeability decreases.

[0032] The thermoplastic acrylic resin layer of the present invention uses thermoplastic acrylic resin as the main body, which contains silica particles.

[0033] (1) Thermoplastic acrylic resins

[0034] The thermoplastic acrylic resin constituting the thermoplastic acrylic resin layer of the present invention is a copolymer of methyl methacrylate and acrylates such as methyl acrylate, ethyl acrylate, or butyl acrylate. The copolymer composition and molecular weight can be appropriately selected according to the co-extrusion conditions. Preferably, the copolymer composition ratio is 80-99% methyl methacrylate and 1-20% acrylates such as methyl acrylate, ethyl acrylate, or butyl acrylate, but not limited thereto. The molecular weight, in weight-average molecular weight, is 30,000-300,000, but not limited thereto. The higher the load flexural temperature of the thermoplastic acrylic resin, the higher its glass transition temperature, and the closer its roll transfer temperature is to that of polycarbonate resin, resulting in excellent roll transferability and the ability to obtain a laminate with excellent appearance. Therefore, the load flexural temperature 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.

[0035] In thermoplastic acrylic resins, rubbery polymers and / or rubber particles can be added to impart impact resistance without significantly reducing transparency and surface hardness. In this case, the Rockwell hardness (M scale) of the resulting thermoplastic acrylic resin composition is preferably 30 or higher. When the Rockwell hardness is below 30, transparency decreases, and when used as a housing, the appearance of printing on the back side deteriorates due to haze, and sometimes the necessary surface hardness cannot be obtained.

[0036] Furthermore, while maintaining its transparency and shapeability, other resins or various additives can be added to the thermoplastic acrylic resin. Examples of additives include, for instance, UV absorbers, antioxidants, anti-coloring agents, flame retardants, mold release agents, antistatic agents, and dyes / pigments. UV absorbers are particularly suitable for preventing UV aging of the polycarbonate resin layer and the thermoplastic acrylic resin layer of this invention.

[0037] Examples of usable ultraviolet absorbers include benzotriazole series, benzophenone series, phenyl salicylate series, benzoxazine series, malonate series, triazine series, and polymeric ultraviolet absorbers obtained by adding them as side groups.

[0038] Examples of benzotriazole-based ultraviolet absorbers include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2-methylenebis[4-(1,1,3,3-tetramethylenebutyl)-6-(2H-benzotriazole-2-yl)phenol], and 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol. Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-octyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, and 2,2-dihydroxy-4,4'-dimethoxybenzophenone.

[0039] In addition, examples of phenyl salicylate-based ultraviolet absorbers include p-tert-butylphenyl salicylate. Examples of benzoxazine-based ultraviolet absorbers include 2,2'-(1,4-phenylene)bis[4H-3,1-benzoxazine-4-one].

[0040] Examples of malonate-based ultraviolet absorbers include dimethyl [(4-methoxyphenyl)-methylene]malonate.

[0041] 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, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, and 2,6-di(4-biphenyl)-4-(2-hydroxy-4-(2-ethylhexyl) Examples of triazine include (-(2-hydroxy-4-hexyloxyphenyl)-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, and 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxy)-1,3,5-triazine, but not limited to these, and also including commonly available ultraviolet absorbers.

[0042] As a polymeric ultraviolet absorber, it is a substance with a hydroxybenzophenone or hydroxybenzotriazole structure in its molecule, or a substance in which the hydrogen atom is replaced by an alkyl group. An example of a polymeric ultraviolet absorber is UVA-633L (2-hydroxy-4-(methacryloyloxyethoxy)benzophenone) methyl methacrylate copolymer produced by BASF.

[0043] Commercially available thermoplastic acrylic resins most suitable for this invention include Parapet HR-1000L manufactured by Kuraray, ALTUGLASV020 manufactured by ARKEMA, and IRG304 manufactured by Mitsubishi Rayon.

[0044] The average thickness of the thermoplastic acrylic resin layer of 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, further preferably 1 μm or more and less than 10 μm, and particularly preferably 1 μm or more and 9 μm or less. By making the average thickness of the thermoplastic acrylic resin layer thinner, the transparency and strength of the laminate can be significantly improved. On the other hand, although the pencil hardness may sometimes decrease, the decrease in pencil hardness can be compensated for by providing, for example, a silica-free thermoplastic acrylic resin layer between the thermoplastic acrylic resin layer and the polycarbonate resin layer in the present invention.

[0045] (2) Silica particles

[0046] The silica particles constituting the thermoplastic acrylic resin layer of the present invention preferably have an average particle size of 0.1 to 2 μm, more preferably 0.2 to 0.6 μm. A small average particle size results in insufficient scratch resistance; a large average particle size leads to an increase in point defects in multilayer sheets and films. The silica particle content relative to the overall thermoplastic acrylic resin layer is more than 1% by mass and less than 10% by mass, preferably more than 1% by mass and less than 5% by mass, more preferably 1.5 to 3.0% by mass. A low silica particle content results in insufficient scratch resistance; a high content leads to increased haze in multilayer sheets and films.

[0047] There are no particular restrictions on the manufacturing method of silica particles; they can be produced using known methods such as the VMC method, wet synthesis method, and melt method. The VMC method is preferred, especially when considering the uniformity of silica particle size. The VMC method involves oxidizing silica powder in an oxygen stream, utilizing the heat of reaction to produce fine, spherical silica particles.

[0048] Commercially available silica 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 used alone or in combination. ADMAFINE SC110G-SQ, in particular, with large particles larger than 10μm controlled to below 100ppm, exhibits minimal point defects when forming laminates using extrusion molding, making it a preferred choice.

[0049] The silica particles contained in the thermoplastic acrylic resin layer of the present invention can be identified by the following methods. The presence of silica particles can be confirmed by observing the surface or cross-section of the molded article using surface observation instruments such as TEM and FE-SEM. These measurements can confirm the dispersion state and surface exudation state of the particles. Furthermore, silica particles can also be identified by simultaneously using surface elemental analysis instruments such as EDX, XPS, and EPMA.

[0050] Furthermore, the average particle size and content of silica particles contained in the thermoplastic acrylic resin layer of the present invention can be determined by the following method.

[0051] As a pretreatment, test pieces and sample solutions can be prepared by the following methods. One method involves embedding a molded body in epoxy resin and then using a surface-cutting device such as an ultramicrotome to cut only the acrylic resin layer from the embedded molded body, dissolving it in a good solvent (dichloromethane, THF, etc.); or another method involves punching out a certain area of ​​the molded article, dissolving the punched section in a good solvent (dichloromethane, THF, etc.).

[0052] The content of silica particles can be determined by the following method. First, filter paper is soaked with a solution containing Si particles of a known concentration and then dried. For use as a calibration curve, fluorescence X-ray determination is performed at three concentration levels. Then, the pretreated and dissolved sample solution is dropped onto filter paper, dried, and the dried filter paper is also measured using a fluorescence X-ray determination device. This allows for the quantification of Si.

[0053] Regarding particle size, particle size measuring devices that utilize principles such as laser diffraction or dynamic light scattering can be used to measure the prepared solution.

[0054] Examples of methods for forming the thermoplastic acrylic resin layer on at least one surface of the polycarbonate resin layer include: co-extrusion of the thermoplastic acrylic resin layer and the polycarbonate resin layer; hot lamination of a thermoplastic acrylic resin film onto the surface of the extruded polycarbonate; and coating a solution containing silica particles dispersed in a thermoplastic acrylic resin solution onto a polycarbonate substrate and drying it. In particular, co-extrusion is most preferred because it allows for the production of multilayer films in a single process, provides flexibility in the thickness ratio of each layer, and offers both sufficient scratch resistance and high transparency. When using hot lamination, the thermoplastic acrylic resin film is preferably an extruded film. For example, when hot laminating a film obtained by injection molding, sufficient scratch resistance may not always be achieved. In addition, in order to achieve sufficient scratch resistance in multilayer sheets and films obtained by coating a solution containing silica particles dispersed in a thermoplastic acrylic resin onto a polycarbonate substrate and then drying it, a large amount of silica particles is required, which may result in impaired transparency.

[0055] The following describes a specific example of a co-extrusion method most suitable for manufacturing the multilayer sheets and multilayer films of the present invention.

[0056] The extrusion apparatus used in manufacturing typically consists of a main extruder for extruding the polycarbonate resin constituting the substrate layer and a secondary extruder for extruding the thermoplastic acrylic resin constituting the coating layer. The secondary extruder is usually smaller than the main extruder. The temperature conditions of the extruder for extruding the polycarbonate resin are typically 230–300°C, preferably 240–290°C; the temperature conditions of the extruder for extruding the thermoplastic acrylic resin are typically 200–270°C, preferably 220–260°C.

[0057] As a general co-extrusion stacking method, there are feed block method, which extends the stacked material that merges in the feed block into the T-die, and multi-manifold method, which expands each layer in each manifold inside the die and merges near the die lip outlet. In this invention, feed block method is preferred.

[0058] In the feed block method, the ratio of the feed block stack width to the effective die lip length is particularly important, preferably ranging from 0.03 to 0.7. Furthermore, the optimal range is 0.05 to 0.2. If the feed block stack width (mm) / effective die lip length (mm) is too large or too small, strip-like defects are likely to appear in the stack. When using the manifold method with equal stack width and effective die lip length, strip-like defects are prone to occur in the film, which is a disadvantageous stacking method for forming the stack of the present invention with a high appearance.

[0059] The mold temperature is typically 230–340°C, preferably 260–320°C. If the mold temperature is too high or too low, the scratch resistance may not be adequately achieved. A laminated and sheet-shaped resin is poured onto forming rollers whose surfaces have been mirror-finished or molded to form a laminate. Cooling occurs during the passage through the forming rollers, further solidifying the laminate. Cooling methods include: a film method where the laminate is clamped under low pressure between rollers 1 and 2, then hung on roller 3 for forming; and a sheet method where the laminate is clamped under high pressure between rollers 1 and 2, forming a dam (resin retention), then clamped under high pressure between rollers 2 and 3, and finally pulled off roller 3 using a receiving roller (dam method). Regardless of the cooling method used, the transparency and scratch resistance of the laminate are the same; therefore, the appropriate method should be selected based on the required thickness and physical properties.

[0060] When the multilayer sheets and multilayer films 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%. Furthermore, the haze of the multilayer sheets and multilayer films 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%.

[0061] The scratch resistance of the multilayer sheets and multilayer films of the present invention can be evaluated by the steel wool hardness test shown below.

[0062] Nippon Steel Wool Co., Ltd. #0000 steel wool was installed on a 33mm x 33mm square pad. This pad was placed on a thermoplastic acrylic resin layer of a laminate held on a table, and abrasion was performed 15 times under a load of 1000g. After cleaning the abraded surface with ethanol, the haze was measured. The haze after this abrasion 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%.

[0063] When using laminates with high haze after the hardness test of steel wool as decorative films and decorative sheets (described later), scratches will occur during daily use, resulting in a poor appearance of the molded products, and therefore it is not preferred.

[0064] The laminate of the present invention is preferably used as a decorative film and decorative sheet. Considering transparency and scratch resistance after manufacturing, a material in which a silica-containing thermoplastic acrylic resin layer is formed on one side of a polycarbonate resin layer is preferred. Examples of decoration methods include: directly printing various designs onto the surface of the polycarbonate resin layer using continuous gravure printing, screen printing, or other similar methods; transferring transfer foil; implementing a metallic plating style using vapor deposition or sputtering; and laminating other resin films decorated by printing or vapor deposition.

[0065] Furthermore, the decorative film and decorative sheet can also be used after being laminated with thermoplastic resin sheets for the purpose of protecting their decorative surfaces. Examples of resins constituting the thermoplastic resin sheets include, for example, polycarbonate resins, thermoplastic acrylic resins, ABS resins, polyvinyl chloride resins, polyurethane resins, polyester resins, polyolefin resins, or resin compositions obtained by mixing at least two of these.

[0066] The obtained decorative film or sheet is laminated onto a thermoplastic resin molded article, with a layer of silica-containing thermoplastic acrylic resin disposed on the side requiring scratch resistance (usually the outer side), thereby obtaining a decorative molded article. Examples of resins constituting the thermoplastic resin molded article include polycarbonate resin, thermoplastic acrylic resin, ABS resin, polyvinyl chloride resin, polyurethane resin, polyester resin, polyolefin resin, or resin compositions obtained by blending at least two of these.

[0067] As a method for obtaining decorative molded articles, known molding methods such as in-mold molding, insert molding, and injection molding with simultaneous bonding can be used. Considering the appearance of the decorative molded articles, in-mold molding and insert molding are particularly suitable as processing methods for the laminates of this invention.

[0068] In-mold molding refers to a method in which decorative film or decorative sheet is pre-formed in an injection mold through vacuum forming or air-pressing, and then molten resin is injected into the mold to form an injection molded product. At the same time, decorative film or decorative sheet is attached to the molded product.

[0069] In addition, insertion molding refers to the method of pre-forming decorative film or decorative sheet through vacuum forming or air-forming, inserting it into an injection molding mold, injecting molten resin into it to form an injection molded product, and at the same time, attaching the decorative film or decorative sheet to the molded product.

[0070] The decorative molded article of the present invention uses a multilayer film or multilayer sheet composed of laminates with excellent scratch resistance as described above as the outermost layer. Therefore, the decorative molded article of the present invention also has excellent scratch resistance.

[0071] Example

[0072] The following are embodiments of the present invention, but the present invention is not limited to these embodiments.

[0073] The evaluation and measurement methods used in this embodiment are shown below.

[0074] (1) Average particle size of silica particles contained in the thermoplastic acrylic resin layer of the laminate

[0075] The particle size distribution was measured using a Nanotrac Wave series EX250 particle size analyzer from Nikkiso Corporation. As a pretreatment, the molded part was punched into circles of a specific area (10 mm in diameter), and the punched pieces were dissolved in THF (tetrahydrofuran). The solution was then placed into the measuring cell of the analyzer, and the average particle size of the silica particles was measured.

[0076] (2) The content of silica particles in the thermoplastic acrylic resin layer of the laminate

[0077] The Si content was quantified using a fluorescence X-ray device.

[0078] (3) Thickness measurement of laminates

[0079] The thickness of the laminate was measured 10 times at its center using a micrometer, and the average value was taken as the thickness.

[0080] (4) Determination of the thickness of the laminate

[0081] The central portion of the laminate was cut, and the cross-section was cut using an ultrathin slicer. The thickness of the polycarbonate resin layer and the thermoplastic acrylic resin layer was measured using a Nikon ME600 optical microscope and a DIGITALSIGHT microscope.

[0082] (5) Hardness test of steel wool

[0083] Nippon Steel Wool Co., Ltd. #0000 steel wool was installed on a 33mm × 33mm square pad, which was then placed on the sample surface held on the stage. The sample was abraded 15 times under a 1000g load. After washing the sample with ethanol, the total transmittance and haze were measured.

[0084] (6) Measurement of total transmittance

[0085] The total transmittance of the laminate was measured using a reflectance and transmittance meter HR-100 manufactured by Murakami Color Technology Research Institute Co., Ltd., in accordance with JISK7361-1.

[0086] (7) Haze Measurement

[0087] The haze of the laminate was measured using a reflectance transmissivity meter HR-100 manufactured by Murakami Color Technology Research Institute Co., Ltd., in accordance with JIS K7136.

[0088] (8) Tensile test (yield stress, nominal deformation at break)

[0089] The yield stress and nominal fracture deformation were measured using Strograph VE20 manufactured by Toyo Seiki Co., Ltd., in accordance with JIS K7161.

[0090] (9) Drop hammer test (fracture energy)

[0091] The membrane is securely fixed using a 5K-50SUSF304 flange. A hemispherical, projectile-shaped hammer with a curvature of 3mmR is placed at the center of the membrane. The rupture energy is calculated based on the weight and height of the membrane rupture using the following formula.

[0092] Fracture energy (J) = Hammer weight at fracture (Kgf) × Fracture height (m) × 9.8 (N / Kgf)

[0093] (10) Appearance

[0094] The obtained laminates by visual inspection are compared with the good-looking laminates that do not contain silica particles.

[0095] (Example 1)

[0096] Polycarbonate-based resin layer materials

[0097] As the polycarbonate resin layer material, Iupilon S-3000RN114 manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used.

[0098] Preparation of thermoplastic acrylic resin layer materials

[0099] The following ingredients were quantitatively supplied using a gravimetric metering feeder: 95.55% by weight of ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin), 3.7% by weight of ADMAFINE SO-C1 (silica with an average particle size of 0.20 μm) produced by ADMATECHS, 0.14% by weight of RIKENVITAMIN, 0.04% by weight of ADKSTABPEP-36 (heat stabilizer) produced by ADEKA, 0.07% by weight of K-NOXBHT (heat stabilizer) produced by Kyodo Pharmaceuticals, and 0.5% by weight of BASF's Tinuvin 1600 (UV absorber). Simultaneously, the mixture was compounded and granulated at 240°C using a Toshiba Machines TEM-26SS twin-screw extruder.

[0100] • Forming of laminated bodies

[0101] For the extruder used for the polycarbonate resin layer (A), a single-screw extruder with a screw diameter of 100 mm and an L / D ratio of 32 and a vent was used. The barrel temperature was set to 280°C, and the screw speed was adjusted to supply feed to the feed block at 236 kg / hr. For the extruder used for the thermoplastic acrylic resin layer (B) containing silica particles as the coating layer, a single-screw extruder with a screw diameter of 50 mm and an L / D ratio of 32 and a vent was used. The barrel temperature was set to 240°C, and the gear pump speed was adjusted to supply feed to the feed block at 10 kg / hr. The screw speed was automatically controlled based on the resin pressure at the gear pump inlet of 7.0 MPa. The two resins, simultaneously supplied to the feed block set to 260°C, were layered with a width of 200 mm, expanded into a film within a mold with an effective die lip length of 1650 mm set to 280°C, and then discharged. The film-like laminate discharged from the mold is sandwiched at 0.25 MPa between a first roller (300 mm diameter, 2000 mm width) and a second roller (450 mm diameter, 2000 mm width), and then hung on a third roller to form a film. The temperatures of each roller are set as follows: first roller: 60°C, second roller: 120°C, third roller: 140°C, and the roller speed is set to 10.9 m / s. For roller number 1, an SF roller manufactured by Chiba Machinery Industry Co., Ltd., with a rubber roller of 5 mm thickness and 80° hardness coated with a mirror-polished metal sleeve, is used. For rollers 2 and 3, general-purpose rigid metal rollers with mirror polishing are used.

[0102] Analysis of the obtained laminate showed that the average particle size and content of silica in the thermoplastic acrylic resin layer were equal to those values ​​used in the preparation of the aforementioned thermoplastic acrylic resin layer material.

[0103] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0104] (Example 2)

[0105] In preparing the thermoplastic acrylic resin layer material, except that the content of ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 96.85% by mass and the content of ADMAFINE SO-Cl (average particle size 0.20 μm) produced by ADMATECHS Co., Ltd. was changed from 3.7% by mass to 2.4% by mass of ADMAFINE SO-Cl (average particle size 0.31 μm), the laminate was obtained according to the same method as in Example 1. Analysis of the obtained laminate showed that the average particle size and content of silica contained in the thermoplastic acrylic resin layer were equal to the values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0106] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0107] (Example 3)

[0108] In preparing the thermoplastic acrylic resin layer material, except that the content of ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 98.15% by mass and the content of ADMAFINE SO-C1 (average particle size 0.20 μm) produced by ADMATECHS Co., Ltd. was changed from 3.7% by mass to 1.1% by mass of ADMAFINE SO-C5 (average particle size 1.50 μm), the laminate was obtained according to the same method as in Example 1. Analysis of the obtained laminate showed that the average particle size and content of silica contained in the thermoplastic acrylic resin layer were equal to the values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0109] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0110] (Example 4)

[0111] In preparing the thermoplastic acrylic resin layer material, the laminate was obtained using the same method as in Example 1, except that the content of ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 89.25% by mass, the content of ADMAFINE SO-C1 (average particle size 0.20 μm) produced by ADMATECHS Co., Ltd. was changed from 3.7% by mass to 10% by mass of ADMAFINE SO-C1 (average particle size 0.20 μm), the discharge rate of the polycarbonate resin layer (A) of the laminate was set to 241 kg / h, and the discharge rate of the thermoplastic acrylic resin layer (B) was set to 3.3 kg / h. Analysis of the obtained laminate showed that the average particle size and content of silica contained in the thermoplastic acrylic resin layer were equal to the values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0112] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0113] (Example 5)

[0114] Except that the discharge amount of the polycarbonate resin layer (A) was set to 114 kg, the laminate was obtained in the same manner as in Example 2. Analysis of the obtained laminate showed that the average particle size and content of silica in the thermoplastic acrylic resin layer were equal to the values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0115] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0116] (Example 6)

[0117] In preparing the thermoplastic acrylic resin layer material, except that ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 96.847% by mass and 0.003% by mass of Shin-Etsu Chemical Industry Co., Ltd.'s silicone oil KF-96 was added, the laminate was obtained using the same method as in Example 2. Analysis of the obtained laminate showed that the average particle size and content of silica in the thermoplastic acrylic resin layer were equal to those values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0118] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0119] (Example 7)

[0120] The preparation of polycarbonate-based resin layer materials and thermoplastic acrylic-based resin layer materials was carried out in the same manner as in Example 2.

[0121] • Forming of laminated bodies

[0122] For the extruder used for the polycarbonate resin layer (A), a single-screw extruder with a screw diameter of 120 mm and an L / D ratio of 32 and a vent was used. The barrel temperature was set to 280°C, and the screw speed was adjusted to supply feed at 305 kg / hr to the feed block. For the extruder used for the thermoplastic acrylic resin layer (B) containing silica particles as the coating layer, a single-screw extruder with a screw diameter of 50 mm and an L / D ratio of 32 and a vent was used. The barrel temperature was set to 240°C, and the gear pump speed was adjusted to supply feed at 1.5 kg / hr to the feed block. The screw speed was automatically controlled based on the resin pressure at the gear pump inlet being 4.0 MPa. The two resins, simultaneously supplied to the feed block set to 260°C, were layered with a width of 200 mm, expanded into a film within a die with an effective die lip length of 1180 mm set to 260°C, and then discharged. Roller 1 (360mm diameter, 1500mm long) and Roller 2 (360mm diameter, 1500mm long) clamp the sheet-like laminate ejected from the mold at 10MPa. After forming a dam (resin retention), Roller 2 and Roller 3 (360mm diameter, 1500mm long) clamp the laminate again at 10MPa. A receiving roller peels the sheet-like laminate from Roller 3 for further molding. The roller temperatures are set as follows: Roller 1: 130℃, Roller 2: 140℃, Roller 3: 180℃; Roller speeds are set as follows: Roller 1: 2.93m / min, Roller 2: 2.93m / min, Roller 3: 2.95m / min, Receiving roller: 3.26m / min. Rollers 1, 2, and 3 are all mirror-polished, standard metal rigid rollers. The receiving roller is a rubber roller with a hardness of 60°.

[0123] Analysis of the obtained laminate showed that the average particle size and content of silica in the thermoplastic acrylic resin layer were equal to those values ​​used in the preparation of the aforementioned thermoplastic acrylic resin layer material. Furthermore, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0124] (Comparative Example 1)

[0125] In preparing the thermoplastic acrylic resin layer material, except that the content of ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 98.75% by mass and the content of ADMAFINE SO-C5 (average particle size 1.50 μm) produced by ADMATECHS Co., Ltd. was changed from 1.1% by mass to 0.5% by mass of ADMAFINE SO-C5 (average particle size 1.50 μm), the laminate was obtained according to the same method as in Example 3. Analysis of the obtained laminate showed that the average particle size and content of silica contained in the thermoplastic acrylic resin layer were equal to the values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0126] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0127] (Comparative Example 2)

[0128] In preparing the thermoplastic acrylic resin layer material, except that the content of ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 87.25% by mass and the content of ADMAFINE SO-Cl (average particle size 0.20 μm) produced by ADMATECHS Co., Ltd. was changed from 10.0% by mass to 12.0% by mass of ADMAFINE SO-Cl (average particle size 0.20 μm), the laminate was obtained according to the same method as in Example 4. Analysis of the obtained laminate showed that the average particle size and content of silica contained in the thermoplastic acrylic resin layer were the same as those values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0129] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0130] (Comparative Example 3)

[0131] In preparing the thermoplastic acrylic resin layer material, except that ARKEMA's ALTUGLASV020 (thermoplastic acrylic resin) was 87.25% by mass and ADMATECHS's ADMAFINE SO-C1 (average particle size 0.20 μm) was replaced with ADMATECHS's ADMANANO YC100C (average particle size 0.09 μm) at 12.0% by mass, the laminate was obtained using the same method as in Example 1. Analysis of the obtained laminate showed that the average particle size and content of silica in the thermoplastic acrylic resin layer were equal to those values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0132] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0133] (Comparative Example 4)

[0134] In preparing the thermoplastic acrylic resin layer material, except that the content of ARKEMA-produced ALTUGLASV020 (thermoplastic acrylic resin) was 99.15% by mass and the content of ADMAFINE SO-C1 (average particle size 0.20 μm) was changed from 3.7% by mass to ADMAFINE SO-C6 (average particle size 2.10 μm) from 0.1% by mass, the laminate was obtained using the same method as in Example 1. Analysis of the obtained laminate showed that the average particle size and content of silica in the thermoplastic acrylic resin layer were equal to those values ​​used in preparing the aforementioned thermoplastic acrylic resin layer material.

[0135] In addition, the thickness and layer thickness of the central portion of the laminate were measured. The thickness measured by a micrometer was equal to the sum of the thicknesses of each layer measured by an optical microscope. A steel wool test was performed on the surface of layer (B) of the laminate, and the total light transmittance and haze were measured before and after the test. The evaluation results are shown in Table 1.

[0136] [Table 1]

[0137]

[0138] Based on the results of the examples and comparative examples summarized in Table 1, the following points are clarified. First, in each of Comparative Examples 1 to 4, the content of silica particles was less than 1% by mass or more than 10% by mass, or the average particle size of the silica particles was less than 0.1 μm or more than 2 μm. Based on these comparative examples, it can be confirmed that the haze value increased significantly or the appearance deteriorated after the scratch resistance test.

[0139] More specifically, in Comparative Example 1 (0.5% by mass), which had a low silica particle content, even using large-sized silica particles, it was confirmed that the haze increased and the abrasion resistance was poor after the steel wool test. In Comparative Example 2 (12% by mass), which had a high silica particle content, even using small-sized silica particles and making the acrylic resin layer as thin as possible, it was confirmed that the steel wool had high haze and poor transparency before the test, resulting in dot-like defects. Furthermore, in Comparative Example 3 (0.09 μm), which had small silica particle size, it was confirmed that the haze was significantly high after the steel wool test, and it did not exhibit any abrasion resistance effect at all. In Comparative Example 4 (2.1 μm), which had large silica particle size, it was confirmed that the steel wool had high haze and poor transparency after the test, resulting in dot-like defects.

[0140] In contrast, in Examples 1-7 of the present invention, unlike the comparative examples described above, an appropriate amount of silica particles with an average particle size within an appropriate range were included in the thermoplastic acrylic resin layer. As a result, it was confirmed that the increase in haze value after the abrasion resistance test was also suppressed, the abrasion resistance of the sheet (laminated body) was excellent, and the appearance of the sheet and the decorative molded article was good. Furthermore, by using silica particles and an appropriate amount of silicone oil together, the abrasion resistance was further improved.

Claims

1. A multilayer sheet or multilayer film, characterized in that, It is composed of a laminate, which uses a polycarbonate resin layer as a substrate, and has a thermoplastic acrylic resin layer containing silica particles on the outermost layer of one or both sides of the substrate. The average thickness of the thermoplastic acrylic resin layer is greater than 2 μm and less than 10 μm. The average particle size of the silica particles is 0.1 to 1.5 μm, and the content of the silica particles is more than 1% by mass and less than 10% by mass relative to the total amount of the thermoplastic acrylic resin layer.

2. The multilayer sheet or multilayer film as described in claim 1, characterized in that, The total light transmittance is above 85% and below 93%, and the haze is above 0.01% and below 0.7%.

3. The multilayer sheet or multilayer film as described in claim 1 or 2, characterized in that, #0000 steel wool was installed on a 33mm×33mm square pad. The pad was subjected to a 1000g load and moved back and forth 15 times on the surface of the thermoplastic acrylic resin layer of the laminate. The haze of the surface after abrasion was greater than 0.01% and less than 1.5%.

4. The multilayer sheet or multilayer film as described in claim 1 or 2, characterized in that, The overall average thickness of the laminate is 0.03 to 2 mm, and the average thickness of the thermoplastic acrylic resin layer is more than 2 μm and less than 9 μm.

5. A decorative molded article, characterized in that, The outermost layer uses a multilayer sheet or multilayer film as described in any one of claims 1 to 4.

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