Metallic resin composition, and metallic resin molding

Abstract

To provide a metallic resin molding which has brightness and texture like metal, and has good smoothness of the surface, and a metallic resin composition which is used for manufacturing the molding.SOLUTION: There are provided a metallic resin composition which contains, with respect to 100 pts.mass of a transparent thermoplastic resin, 1.0 to 3.0 pts.mass of a brilliant material such as aluminum powder, 0.1 to 1.2 pts.mass of an inorganic pigment such as metal-coated mica, 0.2 to 2.0 pts.mass of a compatibilizing agent such as a silane coupling agent, 0.2 to 2.0 ps.mass of a dispersion agent such as a metallic soap, and 0.2 to 2.0 pts.mass of a lubricant such as a polyolefin wax; and a metallic resin molding obtained by molding the composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a metallic resin molded article having a luster and texture like those of a metal, and a metallic resin composition used for producing the molded article.

Background Art

[0002] Metal members are used in many fields such as automobiles and building materials, but there is a strong demand for switching to resin members from the viewpoints of weight reduction and workability. In particular, in the building materials field, since metal members are poor in heat insulation, there is a strong demand for resin members from the viewpoints of energy saving, further weight reduction, and workability. Conventional metallic resin members have employed a method of painting or plating a resin molded article, or a method of attaching a metal foil or metal sheet to the surface of a molded article (Patent Documents 1 and 2). The former has problems in terms of the environment and economy, and the latter has problems such as difficulty in attachment to a molded article having a complex shape and the need for an adhesive. Therefore, a metallic resin molded article composed only of a resin molded article has been desired. Regarding metallic resin molded articles and metallic resin compositions used for producing the molded articles, several proposals have been made in the past (Patent Documents 3 and 4). Although these are all excellent proposals, since a brightening material such as metal powder, which is an inorganic substance, has poor compatibility with a thermoplastic resin as a base material, which is an organic substance, the dispersibility of the brightening material is poor, and a part of it is likely to be exposed as lumps on the surface of the molded article. As a result, the appearance of the molded article is poor, and the metallic luster is insufficient due to poor smoothness, so it is not always satisfactory, and further improvement is desired.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a result of intensive research on the mixing and dispersibility of a transparent thermoplastic resin, a brightening agent, and an inorganic pigment, which are inherently poorly compatible, the inventors of the present application have found that by using a compatibilizer, a dispersant, and a lubricant in combination, the dispersibility of the transparent thermoplastic resin, the brightening agent, and the inorganic pigment is improved. As a result, the obtained resin molded body is excellent in its metallic luster and surface smoothness, and the present invention has been conceived. An object of the present invention is to provide a metallic resin molded body excellent in metallic luster and a metallic resin composition used for producing the molded body.

Means for Solving the Problems

[0005] That is, the present invention is a metallic resin composition characterized by containing 100 parts by mass of a transparent thermoplastic resin, 1.0 to 3.0 parts by mass of a brightening agent, 0.1 to 1.2 parts by mass of an inorganic pigment, 0.2 to 2.0 parts by mass of a compatibilizer, 0.2 to 2.0 parts by mass of a dispersant, and 0.2 to 2.0 parts by mass of a lubricant.

[0006] In the invention of the above metallic resin composition, (1) the compatibilizer is a silane coupling agent, the dispersant is a metal soap, and the lubricant is a hydrocarbon-based lubricant (2) the total light transmittance of the transparent thermoplastic resin is 80% or more (3) the brightening agent is a metal powder (4) the inorganic pigment is a pearl pigment are preferred. In particular, an invention that satisfies all of the requirements (1) to (4) above is preferred.

[0007] The present invention also relates to a metallic resin molded body characterized by molding the above metallic resin composition.

Effects of the Invention

[0008] The metallic resin composition provided by the present invention has a luster and texture like that of metal, has uniform coloring without color unevenness, and is useful for manufacturing a metallic resin molded body with good surface smoothness. By obtaining the metallic resin molded body, it becomes possible to substitute for metal members, resulting in various industrial values such as weight reduction, suppression of the number of processes for pasting metal sheets, etc., production costs, correspondence to complex irregularly shaped members, and improvement of recyclability by full resinification. As a result, the metallic resin molded body can be widely used in various fields such as building materials such as floor joints and sashes; store equipment such as office equipment and showcases; automotive parts such as various instruments, various switches, and grip parts; electronic and electrical parts such as parts and housings of personal computers and mobile phones; and other sports goods, leisure goods, and toys.

Embodiments for Carrying Out the Invention

[0009] <Transparent thermoplastic resin> The transparent thermoplastic resin is a component that serves as the base material of the metallic resin molded body and needs to have transparency in order to develop a metallic tone with the later-described light-emitting material and inorganic pigment. The transparency preferably has a total light transmittance of 80% or more, particularly preferably 85% or more. Examples of the transparent thermoplastic resin include acrylic resins such as polymethyl methacrylate, polycarbonate resins, polystyrene resins, polyethylene terephthalate resins, PVC (polyvinyl chloride) resins, ABS (acrylonitrile-butadiene-styrene) resins, ASA (acrylonitrile-styrene-acrylate) resins, and the like. From the viewpoints of adhesion during multi-color (multi-layer) molding, chemical resistance, weather resistance, etc., acrylic resins and ASA resins are suitable.

[0010] <Light-emitting material> The light-emitting material is a component that, in cooperation with the inorganic pigment, causes the resin molded body to develop a metallic tone. Specifically, examples include metal powders such as aluminum, iron, nickel, chromium, tin, zinc, indium, titanium, or copper; alloy powders composed of two or more of the above metals; vapor deposition products of the above metals or pulverized products thereof. Each particle constituting the light-emitting material may be coated with a colorant or a resin. In particular, a pulverized product of a metal vapor deposition product coated with a resin containing a colorant has good compatibility with a compatibilizer described later and is preferred. The light-emitting material is usually a plate-like or granular powder having an average particle diameter of 10 to 300 μm. From the viewpoints of uniform dispersibility, metallic color development property, and surface smoothness, the average particle diameter is preferably 50 to 200 μm, and particularly preferably 75 to 120 μm. In the present invention, the average particle diameter of the powder used means the particle diameter (D50) at the integrated value of 50% in the particle size distribution determined by the laser diffraction / scattering method. It is necessary to blend 1.0 to 3.0 parts by mass of the light-emitting material with respect to 100 parts by mass of the transparent thermoplastic resin. If it is less than 1.0 part by mass, sufficient metallic color development does not occur. If it exceeds 3.0 parts by mass, the light-emitting material is exposed on the surface of the molded body. In addition, the surface smoothness deteriorates, which is not preferable. From the viewpoint of suppressing these defects, it is preferably 1.0 to 2.0 parts by mass. Two or more kinds of light-emitting materials may be used in combination, but the total amount thereof needs to be within the above range.

[0011] <Inorganic Pigment> The inorganic pigment is a component that functions to develop a metallic color in cooperation with the light-emitting material. There is no particular limitation as long as it is an inorganic pigment, and natural mineral pigments such as red clay, yellow clay, green clay, malachite, lead white, and graphite, and synthetic inorganic pigments such as ultramarine, zinc white, cobalt blue, emerald green, viridian, and titanium white are adopted. The inorganic pigment is classified, from the viewpoint of its function, into extender pigments used for adjusting the feel of use, coloring pigments used for adjusting the color tone, white pigments used for adjusting the color and absorbing ultraviolet rays, pearl pigments that exhibit a luster, and the like. In the present invention, pearl pigments are preferably adopted because they can adjust the color while exhibiting a luminance sense and are excellent in the metallic luster when used in combination with the light-emitting material. Pearl pigments are pigments that exhibit a deep luster like that of pearls by utilizing multiple reflections and interference phenomena of light. Chemically, they include metal-coated mica in which fine crystals of metal oxides such as titanium oxide and iron oxide are coated on the surface of natural mica such as muscovite, biotite, and phlogopite, or synthetic mica synthesized by melting and fusing raw materials such as aluminum oxide, magnesium oxide, silicon dioxide, and fluorine compounds at a high temperature of about 1500°C; and metal-coated inorganic oxide pigments in which fine crystals of metal oxides are coated on the surface of plate-like particles such as silica, alumina, or borosilicate glass. In particular, from the viewpoint of better expressing metallic and glittering feelings, metal-coated mica is preferably adopted. Metal-coated mica is natural or synthetic mica coated on the surface with about 20 to 50% by mass of metal oxides such as titanium oxide, iron oxide, tin oxide, and zinc oxide. Its manufacturing method is known and is described, for example, in JP-A-10-279828. It is also commercially available from Nippon Kogaku Kogyo Co., Ltd. and others. Inorganic pigments are usually plate-like or granular powders with an average particle diameter of 5 to 200 μm. From the viewpoints of uniform dispersibility, metallic color development, and surface smoothness, the average particle diameter is preferably 5 to 100 μm, and particularly preferably 5 to 50 μm. It is necessary to blend 0.1 to 1.2 parts by mass of the inorganic pigment with respect to 100 parts by mass of the transparent thermoplastic resin. If it is less than 0.1 part by mass, good metallic color development does not occur. If it exceeds 1.2 parts by mass, aggregates are likely to be formed, and the surface state deteriorates due to lumps and streaks. From the viewpoint of suppressing these, it is preferably 0.1 to 1.0 part by mass.

[0012] <Compatibilizer> The compatibilizer is a component that enables uniform mixing and dispersion of the above-mentioned glitter material and inorganic pigment with the transparent thermoplastic resin. Usually, a silane coupling agent is used. The silane coupling agent is a compound having a function of bonding an organic material and an inorganic material, which has a reactive hydrolyzable group and an organic functional group that chemically bonds to the organic material, and known compounds are adopted without any limitation. Specifically, examples include γ-(meth)acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ-(N-styrylmethyl-β-aminoethylamino)propyltrimethoxysilane hydrochloride, γ-mercaptopropyltrimethoxysilane, etc. In particular, long-chain spacer-type silane coupling agents such as 7-octenyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, and 8-methacryloxyoctyltrimethoxysilane, in which the hydrocarbon group connecting the organic functional group and the silyl group has 6 to 8 carbon atoms, are suitable in terms of excellent uniform mixing of the brightening material and the inorganic pigment with the transparent thermoplastic resin. The compatibilizer needs to be blended in an amount of 0.2 to 2.0 parts by mass based on 100 parts by mass of the transparent thermoplastic resin. If it is less than 0.2 parts by mass, the uniform dispersion effect will not be exhibited. Even if it exceeds 2.0 parts by mass, the effect will saturate and lead to an increase in cost. From the viewpoint of the uniform mixing and dispersion effect, 0.2 to 0.6 parts by mass is preferable.

[0013] <Dispersant> The dispersant, in combination with the lubricant, exhibits a synergistic effect of further improving the uniform dispersion effect of the compatibilizer. As the dispersant, long-chain fatty acid metal salts in which a metal and a long-chain fatty acid are bonded, generally called metal soaps, are used. There is no particular limitation as long as it is a metal soap. Specifically, metal stearates such as lithium stearate, magnesium stearate, calcium stearate, barium stearate, and zinc stearate; metal laurates such as calcium laurate, barium laurate, and zinc laurate; metal ricinoleates such as calcium ricinoleate, barium ricinoleate, and zinc ricinoleate; metal octylates such as zinc octylate, etc. are mentioned. Metal stearates are preferably used in terms of making the surface smooth and improving the brightness. The dispersant needs to be blended in an amount of 0.2 to 2.0 parts by mass based on 100 parts by mass of the transparent thermoplastic resin. If it is less than 0.2 parts by mass, the function of the compatibilizer cannot be improved. Even if it exceeds 2.0 parts by mass, the synergistic effect is saturated, leading to an increase in cost. From the viewpoint of a uniform dispersion effect, 0.2 to 0.6 parts by mass is preferable.

[0014] <Lubricant> The lubricant, in combination with the dispersant, exhibits a synergistic effect of further improving the uniform dispersion effect of the compatibilizer. Examples of the lubricant include fatty acid-based lubricants such as stearic acid and behenic acid; higher alcohol-based lubricants such as stearyl alcohol; fatty acid amide-based lubricants such as stearic acid amide and oleic acid amide; fatty acid ester-based lubricants such as glycerin monostearate and glycerin monooleate; and hydrocarbon-based lubricants for resins, which can be used without limitation. Particularly, hydrocarbon-based lubricants are preferable. Specifically, there are polyolefin waxes such as liquid paraffin, paraffin wax, and low molecular weight polyolefins obtained by thermal decomposition of polyolefins such as polyethylene and polypropylene. Polyolefin wax is particularly suitable in terms of excellent surface smoothness. The lubricant needs to be blended in an amount of 0.2 to 2.0 parts by mass based on 100 parts by mass of the transparent thermoplastic resin. If it is less than 0.2 parts by mass, the function of the compatibilizer cannot be improved. Even if it exceeds 2.0 parts by mass, the synergistic effect is saturated, leading to an increase in cost. From the viewpoint of a uniform dispersion effect, 0.2 to 0.6 parts by mass is preferable.

[0015] <Additive> In the metallic resin composition, conventionally known additives such as antioxidants, ultraviolet absorbers, light-resistant agents, heat-resistant agents, and impact-resistant agents can be blended within a range that does not impair the effects of the present invention, as necessary. The additive may be added when preparing the metallic resin composition, but it is preferably mixed with the transparent thermoplastic resin in advance.

[0016] <Preparation of Metallic Resin Composition> There are no particular restrictions on the method for preparing the metallic resin composition of the present invention. For example, a transparent thermoplastic resin, a light-emitting material, an inorganic pigment, a compatibilizer, a dispersant, a lubricant, and various additives used as desired are dry-blended at predetermined ratios using a blender, a Henschel mixer, or the like to obtain the composition. In particular, it is desirable to use a melt-kneading machine such as a single-screw or twin-screw extruder, a plast mill, a Brabender, a Banbury mixer, a pressure kneader, a conical kneader, etc. to uniformly knead and disperse them into a pellet-shaped metallic resin composition.

[0017] <Manufacture of Metallic Resin Molded Body> The metallic resin molded body of the present invention can be produced by kneading the above thermoplastic resin composition with various additives added as necessary by known molding methods such as injection molding, extrusion molding, vacuum molding, and blow molding. The molding machine and molding conditions, etc. may be appropriately selected and determined according to the type of the transparent thermoplastic resin contained, the shape and structure of the metallic resin molded body, etc. For example, from the viewpoints of mass productivity and continuous and stable manufacturability, the extrusion molding method is preferably adopted to obtain a molded body corresponding to the target cross-sectional shape. For the metallic resin molded body by the extrusion molding method, methods such as extruding from a T-die after melting by an extruder, or biaxially stretching by a tenter method or an inflation method after extruding into a sheet shape from an extruder are adopted. The stretching may be uniaxial stretching, sequential biaxial stretching, simultaneous biaxial stretching, or biaxial stretching by the inflation method. Furthermore, it can also be molded by the ordinary injection molding method. The injection molding temperature, injection molding pressure, etc. are appropriately selected according to the mold used, the shape and structure of the target metallic resin molded body, and the components of the metallic resin composition typified by the transparent thermoplastic resin contained. The metallic resin composition of the present invention may be used for multi-color (multi-layer) molding by the extrusion molding method or the injection molding method. When used for the surface layer, it is usually laminated with a thickness of 0.1 to 0.5 mm.

Examples

[0018] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Also, not all combinations of features described in the examples are essential for the solution means of the present invention. The various components, abbreviations, and evaluation methods used in the following examples and comparative examples are as follows.

[0019] 〔Transparent thermoplastic resin〕 PMMA: Polymethyl methacrylate resin Total light transmittance: 92% ASA: Acrylonitrile-styrene-acrylate resin Total light transmittance: 89% 〔Light-emitting material〕 Aluminum powder: The pulverized product of an aluminum vapor-deposited resin film coated with a resin containing a colorant Flaky particles, average particle diameter 90 - 100 μm 〔Inorganic pigment〕 TI mica: Titanium oxide-coated synthetic mica particles Average particle diameter: 13 μm 〔Compatibilizer〕 8-MOS: 8-Methacryloxyoctyltrimethoxysilane 〔Dispersant〕 STMG: Magnesium stearate 〔Lubricant〕 OLWA: Polyethylene wax, off-white granules, melting point 100 - 120 °C

[0020] 〔Surface characteristics〕 The surface state of the flat extruded product was visually compared using a miscellaneous object measurement chart and judged by the number of bumps corresponding to 100 μm or more generated on the surface. ◎: 0 pieces 〇: 1 piece ×: 2 pieces or more 〔Gloss characteristics〕 The appearance of the surface of the flat extruded product was visually observed and evaluated according to the following criteria. ◎: The light-emitting property is very excellent, and the appearance is comparable to that of metal. 〇: The light-emitting property is excellent, and the appearance is similar to that of metal. △: It has light volatility but a lackluster metallic appearance. ×: It has poor light volatility and a non-metallic appearance.

[0021] Example 1 100 parts by mass of PMMA, 1.0 part by mass of aluminum powder, 0.1 part by mass of TI mica, 0.2 part by mass of 8-MOS, 0.2 part by mass of STMG, and 0.2 part by mass of OLWA were mixed at 100 °C using a Henschel mixer, and then pelletized using a co-rotating twin-screw extruder to produce a pellet-like metallic resin composition. The above metallic resin composition was extrusion molded under the condition of a melting temperature of 210 °C using a "Laboplast Mill 4C150" manufactured by Toyo Seiki Co., Ltd. to obtain a flat molded body (1000 cm × 3 cm × 2 mm). The surface characteristics and gloss characteristics of this flat molded body were evaluated according to the above method. The results are shown in Table 1.

[0022] Examples 2 to 11 A metallic resin composition was produced in the same manner as in Example 1 except that the components were mixed at the blending ratios shown in Table 1, and then extrusion molding was further performed. Various evaluations were carried out using the obtained flat molded body, and the results are shown in Table 1.

[0023] Example 12 A metallic resin composition was produced in the same manner as in Example 1 except that the acrylic resin (PMMA) was changed to an ASA resin, and then extrusion molding was performed under the condition of a melting temperature of 190 °C to obtain a flat molded body of the same shape. Various evaluations were carried out on the obtained flat molded body, and the results are shown in Table 1.

[0024] Example 13 The metallic resin composition used in Example 1 was co-extruded onto the surface layer of a PVC resin (thickness 1.7 mm) with a thickness of 0.3 mm for integral molding to obtain a flat two-color (two-layer) molded body of the same shape as in Example 1. Various evaluations were carried out on the obtained flat molded body, and the results are shown in Table 1.

[0025]

Table 1

[0026] Comparative Examples 1 to 7 A metal-tone resin composition was produced in the same manner as in Example 1 except that each component was mixed at the blending ratios shown in Table 2, and further extrusion molding was performed. The surface characteristics and the brilliance characteristics of the obtained flat molded body were evaluated according to the above method. The results are shown in Table 2.

[0027]

Table 2

[0028] Comparative Example 1 is an example in which the content of the brilliance agent is small, and the brilliance characteristics are insufficient. Comparative Example 2 is an example in which the content of the brilliance agent is large. The brilliance characteristics are excellent, but the surface characteristics are extremely poor. Comparative Example 3 is an example that does not contain an inorganic pigment. The surface characteristics are good, but the brilliance characteristics are insufficient. Comparative Example 4 is an example in which the content of the inorganic pigment is large. The brilliance characteristics are sufficient, but the surface characteristics are extremely poor. Comparative Example 5 is an example in which the content of the compatibilizer is small. The brilliance characteristics are sufficient, but the surface characteristics are extremely poor. Comparative Example 6 is an example in which the content of the dispersant is small. The brilliance characteristics are sufficient, but the surface characteristics are extremely poor. Comparative Example 7 is an example in which the content of the lubricant is small. The brilliance characteristics are sufficient, but the surface characteristics are extremely poor.

Claims

1. A metallic resin composition comprising 100 parts by mass of a transparent thermoplastic resin, 1.0 to 3.0 parts by mass of a brightening agent, 0.1 to 1.2 parts by mass of an inorganic pigment, 0.2 to 2.0 parts by mass of a compatibilizer, 0.2 to 2.0 parts by mass of a dispersant, and 0.2 to 2.0 parts by mass of a lubricant.

2. The metallic resin composition according to Claim 1, wherein the compatibilizer is a silane coupling agent, the dispersant is a metal soap, and the lubricant is a hydrocarbon-based lubricant.

3. The metallic resin composition according to Claim 1, wherein the total light transmittance of the transparent thermoplastic resin is 80% or more.

4. The metallic resin composition according to Claim 1, wherein the brightening agent is a metal powder.

5. The metallic resin composition according to Claim 1, wherein the inorganic pigment is a pearl pigment.

6. A metallic resin molded article obtained by molding the metallic resin composition according to any one of Claims 1 to 5.

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