Method for producing additive for resin molding

Abstract

To provide a technique related to improvement of functionality of a resin molding.SOLUTION: A method for producing an additive for a resin molding includes decompressing fluid containing supercritical fluid and a raw material additive soluble in the supercritical fluid, and precipitating an additive having a smaller average particle diameter than the raw material additive.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing an additive for a resin molded product. [Background technology]

[0002] Molded articles made of resin are used in a variety of fields. For example, laminated films made of multiple resin layers can exhibit performance and functions that cannot be achieved by single-layer films, and are therefore used in a wide range of fields, including decorative sheets, packaging materials, and electronic components.

[0003] Decorative sheets are used, for example, as building materials for the interior and exterior decoration of buildings, or as surface materials for fixtures or home appliances. Decorative sheets are used as decorative panels by being attached to substrates such as wood boards, inorganic boards, and metal plates.

[0004] Decorative sheets generally use polyvinyl chloride, as described in Patent Document 1. However, such decorative sheets generate toxic gases when burned. For this reason, many decorative sheets have been proposed that use polyolefin resins instead of polyvinyl chloride, as described in Patent Documents 2 to 4.

[0005] Decorative sheets that use polyolefin resins instead of polyvinyl chloride do not emit chlorine-derived toxic gases when burned. However, because these decorative sheets use general polypropylene sheets or soft polypropylene sheets, they have far inferior scratch resistance compared to decorative sheets that use polyvinyl chloride.

[0006] The use of highly crystalline polypropylene, which has a high initial bending modulus, as the polyolefin resin can achieve excellent abrasion resistance. However, decorative sheets using such highly crystalline polypropylene can sometimes break or crack around the periphery when subjected to bending processes such as V-groove bending.

[0007] Furthermore, polypropylene resins are usually milky white because their spherulite size is larger than the wavelength of visible light (400 to 750 nm). In decorative sheets, the transparent resin layer is required to protect the underlying pattern layer and base sheet, while not interfering with the visibility of the patterns and designs printed thereon from the outermost surface of the decorative sheet.

[0008] To address these issues, Patent Document 5 describes the encapsulation of a nucleating agent in an outer membrane made of phospholipids by supercritical reverse-phase evaporation, and the addition of the resulting vesicles to a crystalline polypropylene resin. The vesicles obtained by supercritical reverse-phase evaporation are extremely small in size. Therefore, adding these vesicles to a crystalline polypropylene resin can significantly reduce the size of the spherulites and dramatically improve the crystallinity of the crystalline portion. As a result, high transparency can be achieved, as well as excellent scratch resistance and post-processing resistance.

[0009] The nano-processing of nucleating agents using the supercritical reverse-phase evaporation method described above involves injecting an aqueous phase into a mixture of supercritical carbon dioxide, an organic solvent, a phospholipid, and a nucleating agent, followed by vigorous stirring to generate an emulsion of supercritical carbon dioxide and an aqueous phase. The carbon dioxide then expands and evaporates under reduced pressure, resulting in phase inversion, producing vesicles consisting of nanocapsules in which the phospholipid covers the surface of the nucleating agent with a monolayer membrane. In this nano-processing, there is concern about vesicle size variation depending on the degree of stirring and mixing. Furthermore, from the perspective of production cost, it is desirable to reduce the number of steps and enable production using a simple manufacturing method. Furthermore, a common problem with resin molded products is the bleed-out phenomenon, in which incorporated additives and residual solvents rise to the surface over time. Therefore, it is preferable to reduce the types and amounts of these additives and organic solvents. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2-128843 [Patent Document 2] Japanese Patent Application Publication No. 5-278137 [Patent Document 3] Japanese Patent Application Publication No. 6-198831 [Patent Document 4] Japanese Patent Application Publication No. 9-328562 [Patent Document 5] Japanese Patent Application Laid-Open No. 2016-168830 Summary of the Invention [Problem to be solved by the invention]

[0011] Various additives are used in various resin molded products, such as stabilizers to prevent deterioration due to heat, light, oxidation, etc. during or after molding processing, modifiers to impart strength, transparency, color tone, etc., and nucleating agents. If the functions of the various additives used in these resin molded products can be maximized, the functionality of the resin molded products can be significantly improved.

[0012] An object of the present invention is to provide a technique for improving the functionality of a resin molded product. [Means for solving the problem]

[0013] According to one aspect of the present invention, there is provided a method for producing an additive for a resin molded product, the method comprising reducing the pressure of a fluid containing a supercritical fluid and a raw material additive soluble in the supercritical fluid to precipitate an additive having a smaller average particle size than the raw material additive.

[0014] According to another aspect of the present invention, there is provided a method for producing an additive for a resin molded product according to the above aspect, wherein the pressure reduction of the fluid is carried out in a pressure-resistant container.

[0015] According to yet another aspect of the present invention, there is provided the method for producing an additive for a resin molded product according to the above aspect, wherein the decompression of the fluid includes spraying the fluid from inside the pressure-resistant container to the outside of the pressure-resistant container.

[0016] According to yet another aspect of the present invention, there is provided a method for producing an additive for a resin molded product according to any of the above aspects, in which the raw material additive has an average particle size of 2 μm or more, and the additive having a smaller average particle size than the raw material additive has an average particle size of less than 2000 nm.

[0017] According to yet another aspect of the present invention, there is provided a method for producing an additive for a resin molded product according to any one of the above aspects, wherein the additive is a nucleating agent.

[0018] According to yet another aspect of the present invention, there is provided a method for producing an additive for a resin molded product according to any one of the above aspects, wherein the additive is a plastic decomposition inhibitor.

[0019] According to yet another aspect of the present invention, there is provided the method for producing an additive for a resin molded product according to any one of the above aspects, wherein the supercritical fluid comprises carbon dioxide.

[0020] According to yet another aspect of the present invention, there is provided a method for producing a masterbatch, the method including: producing the additive by the method for producing an additive for a resin molded product according to any one of the above aspects; and kneading a first raw material resin and a raw material containing the additive.

[0021] According to yet another aspect of the present invention, there is provided a method for producing a masterbatch according to the above aspect, which comprises kneading the raw materials in the presence of a supercritical fluid.

[0022] According to yet another aspect of the present invention, there is provided the method for producing a masterbatch according to any one of the above aspects, wherein the first raw material resin is a resin in which the proportion of polyolefin resin is in the range of 90 to 100 mass %.

[0023] According to yet another aspect of the present invention, there is provided a method for producing a resin, the method including: producing the masterbatch by the method for producing a masterbatch according to any of the above aspects; and kneading the masterbatch with a raw material including a second raw material resin.

[0024] According to yet another aspect of the present invention, there is provided a method for producing a resin according to the above aspect, wherein the first raw resin and the second raw resin are each independently a resin having a polyolefin resin content in the range of 90 to 100 mass %.

[0025] According to yet another aspect of the present invention, there is provided a method for manufacturing a resin molded product, the method including: manufacturing the resin by the resin manufacturing method according to any one of the above aspects; and molding the resin to manufacture a resin molded product.

[0026] According to yet another aspect of the present invention, there is provided a method for producing a resin molded article according to the above aspect, wherein the concentration of the additive in the resin molded article is within a range of 0.0005 to 1% by mass.

[0027] According to yet another aspect of the present invention, there is provided a method for producing a resin molded article according to any one of the above aspects, wherein the resin molded article is a resin layer.

[0028] According to yet another aspect of the present invention, there is provided a method for manufacturing a laminate, comprising forming the resin layer by the method for manufacturing a resin molded article according to any of the above aspects, and laminating one or more other layers onto the resin layer.

[0029] According to yet another aspect of the present invention, there is provided a method for producing a laminate according to the above aspect, wherein the laminate is a decorative sheet.

[0030] According to yet another aspect of the present invention, there is provided an additive for resin molding obtained by the method for producing an additive for resin molded products according to any one of the above aspects.

[0031] According to yet another aspect of the present invention, there is provided a masterbatch obtained by the method for producing a masterbatch according to any of the above aspects.

[0032] According to yet another aspect of the present invention, there is provided a resin molded product obtained by the method for producing a resin molded product according to any one of the above aspects.

[0033] According to yet another aspect of the present invention, there is provided a resin layer obtained by the method for producing a resin molded article according to any one of the above aspects.

[0034] According to yet another aspect of the present invention, there is provided a laminate obtained by the method for producing a laminate according to any of the above aspects.

[0035] According to yet another aspect of the present invention, there is provided a laminate according to the above aspect which is a decorative sheet. [Effects of the Invention]

[0036] The present invention provides a technique for improving the functionality of a resin molded product. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] The following describes embodiments of the present invention. The embodiments described below are more specific embodiments of any of the above aspects. The following features can be incorporated into each of the above aspects, either singly or in combination.

[0039] Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited by the materials, shapes, structures, etc. of the components described below. Various modifications can be made to the technical idea of ​​the present invention within the technical scope defined by the claims.

[0040] It should be noted that the drawings referred to below are schematic, and the relationship between dimensions in one direction and dimensions in another direction, and the relationship between the dimensions of one component and the dimensions of another component, etc. may differ from the actual figures.

[0041] <1> Additives for resin moldings The method for producing an additive for a resin molded product according to an embodiment of the present invention is a technology for nano-processing an additive for a resin molded product using a supercritical fluid. That is, the method for producing an additive for a resin molded product according to the present embodiment includes reducing the pressure of a fluid containing a supercritical fluid and a raw material additive soluble in the supercritical fluid to precipitate an additive having a smaller average particle size than the raw material additive.

[0042] In this method, as described above, a substance soluble in a supercritical fluid is selected as the raw additive to be nano-processed, so that a high-pressure fluid in which the raw additive is dissolved in the supercritical fluid can be easily obtained, and then additive fine particles with small particle size variation can be easily obtained simply by depressurizing this high-pressure fluid. There is no need to use special organic solvents or dispersants.

[0043] Additives nano-sized by this method have small particle size variations and can be distributed with high dispersity in the resin. Therefore, even a small amount added to the resin can achieve the significant effects required of the additive. Hereinafter, additives for resin molded products nano-sized by the method according to this embodiment may be simply referred to as "additive microparticles."

[0044] Bleeding out due to additives in resin molded products is a phenomenon in which the additives aggregate and coarsen over time, eventually precipitating on the surface of the resin molded product. Therefore, this method refines coarse particles to obtain additive fine particles with small particle size variation, and by using these as additives for resin molded products, it is possible to suppress bleed-out.

[0045] Furthermore, as described above, the additive obtained by this method exerts a significant effect even in a small amount, so that the amount used can be reduced, and therefore bleeding out due to a high concentration of the additive can be prevented.

[0046] Furthermore, since this method does not use a dispersant such as phospholipid or an organic solvent, bleeding out due to these remaining in the resin molded product does not occur.

[0047] There are a wide variety of additives for resin moldings, i.e., additives used in resin moldings, including those that improve the physical properties of resins and those that impart properties that resins do not inherently possess. The method according to this embodiment can be applied to nano-processing of various additives added to resins. Examples of additives for resin moldings include nucleating agents, plastic decomposition inhibitors, plasticizers, flame retardants, antistatic agents, colorants, lubricants, reinforcing agents, antifogging agents, antibacterial agents, and surfactants. However, additives for resin moldings must be soluble in supercritical fluids.

[0048] Nucleating agents either promote the formation of crystal nuclei during resin crystallization or act as crystal nuclei themselves. Examples of nucleating agents include metal salts of phosphate esters, metal salts of aromatic carboxylic acids, metal salts of pieric acid, metal salts of rosin, amide compounds, benzylidene sorbitol, quinacridone, cyanine blue, etc. For example, by adding nano-sized nucleating agent particles to a transparent resin layer using the method according to this embodiment, it is possible to achieve high levels of both post-processing resistance and scratch resistance in a transparent resin layer having excellent transparency.

[0049] A plastic decomposition inhibitor is a stabilizer that prevents deterioration of a resin molded product due to heat, light, oxidation, etc. during or after molding processing. Examples of plastic decomposition inhibitors include antioxidants, light stabilizers, and heat stabilizers.

[0050] Examples of antioxidants include phosphorus-based, phenol-based, and thioether-based ones. Examples of light stabilizers include hindered amine-based, benzotriazole-based, and triazine-based ones. Examples of heat stabilizers include oxalic acid compounds, amide compounds such as salicylic acid, and hydrazide compounds.

[0051] Using the method for producing additives for resin molded products according to this embodiment, nano-processing two or more additives and using the resulting multiple additive microparticles in resin molded products is preferable because it makes it possible to improve multiple performance properties of the resin molded product. The method for nano-processing two or more additives may involve simultaneously nano-processing two or more additives as a mixture, or nano-processing two or more additives individually. The former can be achieved by reducing the pressure of a fluid containing a supercritical fluid and two or more additives.

[0052] As a method for nano-processing two or more additives, nano-processing two or more additives simultaneously as a mixture is preferable because it is possible to precipitate additive fine particles with a smaller average particle size compared to nano-processing them individually. This is presumably because when the additive fine particles are precipitated from the supercritical fluid, they mutually inhibit the aggregation of each additive fine particle.

[0053] Furthermore, among additives, surfactants are excellent at reducing the average particle size of the resulting additive particles when mixed with other additives and simultaneously nano-processed. This is presumably due to the surfactant's ability to cover the other additive particles. Therefore, in the manufacturing method for additives for resin molded products according to this embodiment, a method in which two or more raw material additives, including a surfactant, are mixed and simultaneously nano-processed can be cited as one preferred embodiment.

[0054] Whether a raw material additive is soluble in a supercritical fluid can be determined as follows. That is, 50 mg of the raw material additive is placed in a 5 mL pressure-resistant container. A supercritical fluid is injected into the container to bring the temperature to 40°C and the pressure to 20 MPa, and the container is maintained under these conditions for 10 minutes. The pressure-resistant container is then opened, and the mass of the remaining raw material additive is measured. If the mass of the remaining raw material additive is 40 mg or less, the raw material additive can be determined to be a "raw material additive soluble in a supercritical fluid."

[0055] The supercritical fluid may be, for example, carbon dioxide or nitrogen. Carbon dioxide becomes a supercritical fluid under conditions of 31.1°C or higher and 7.38 MPa or higher. Carbon dioxide is preferably used as the supercritical fluid because of its high safety, low critical temperature of 31.1°C, and ability to vaporize quickly after being ejected into a collector.

[0056] The method for producing an additive for a resin molded product according to this embodiment can utilize either a rapid expansion method or a slow expansion method. These two methods differ in the decompression means used to precipitate additive fine particles from a high-pressure fluid in which the additive is dissolved in a supercritical fluid. The former rapid expansion method decompresses the high-pressure fluid by spraying the fluid from inside the pressure-resistant vessel to the outside of the pressure-resistant vessel, while the latter slow expansion method decompresses the high-pressure fluid inside the pressure-resistant vessel to obtain additive fine particles inside the pressure-resistant vessel. These methods are described below.

[0057] <Rapid expansion method> The rapid expansion method, also known as the RESS method (Rapid Expansion of Supercritical Solutions), involves dissolving a substance in a supercritical fluid in a pressure-resistant container, spraying it into a collector, and rapidly reducing the pressure to rapidly precipitate particles and obtain fine particles. A nozzle is typically used to spray the material into the collector. In the method according to this embodiment, an additive soluble in a supercritical fluid is selected as the substance, and after dissolving it in the supercritical fluid, additive fine particles with small particle size variations can be easily obtained simply by opening the valve connecting the pressure-resistant container and the nozzle. There is no need to use a special organic solvent or dispersant.

[0058] In the treatment using a supercritical fluid in a pressure vessel, the mixing ratio of the raw material additive and the supercritical fluid introduced into the pressure vessel can be appropriately set, for example, in the range of 100 to 1,000,000 parts by mass of the supercritical fluid per 100 parts by mass of the raw material additive, or in the range of 200 to 100,000 parts by mass of the supercritical fluid.

[0059] In the treatment using a supercritical fluid in a pressure-resistant vessel, the pressure and temperature can be appropriately set. For example, the treatment can be performed at a pressure in the range of 7.2 to 100 MPa, or at a pressure in the range of 10 to 80 MPa. The treatment can also be performed at a temperature in the range of 32 to 250°C, or at a temperature in the range of 35 to 200°C.

[0060] Under the above-mentioned conditions, the raw material additives must be dissolved in the supercritical fluid, but the entire amount of the raw material additives does not have to be dissolved. Furthermore, a co-solvent such as methanol, ethanol, or toluene may be added to the supercritical fluid that serves as the solvent. However, in this case, after the fluid is ejected from the nozzle, it is preferable to quickly heat the ejection portion of the nozzle or the like to vaporize the solvent and prevent residual solvent from remaining.

[0061] The treatment using the supercritical fluid in the pressure vessel may be carried out under stirring as necessary. The stirring speed and stirring time can be appropriately set.

[0062] This rapid expansion method allows for continuous injection of the supercritical fluid by maintaining pressure with a back pressure valve, a needle valve, or other pressure control device or nozzle. In this case, even if the solubility of the additive is low (2 mg / volume 1 mL), the injection of fine particles can be continued by continuing to inject new supercritical fluid.

[0063] <Slow expansion method> The slow expansion method, also known as SESS (Slow Expansion of Supercritical Solutions), involves dissolving a substance in a supercritical fluid in a pressure vessel, then reducing the pressure inside the vessel to precipitate particles within the vessel, thereby obtaining fine particles.

[0064] In this method, additives that are soluble in supercritical fluids are selected as the above-mentioned substances, and after dissolving them in the supercritical fluid, additive fine particles with small particle size variations can be easily obtained simply by reducing the pressure inside the pressure-resistant container. There is no need to use special organic solvents or dispersants.

[0065] In the treatment using a supercritical fluid in a pressure vessel, the mixing ratio of the raw material additive and the supercritical fluid introduced into the pressure vessel can be appropriately set, for example, in the range of 100 to 1,000,000 parts by mass of the supercritical fluid per 100 parts by mass of the raw material additive, or in the range of 200 to 100,000 parts by mass of the supercritical fluid.

[0066] In the treatment using a supercritical fluid in a pressure-resistant vessel, the pressure and temperature can be appropriately set. For example, the treatment can be performed at a pressure in the range of 7.2 to 100 MPa, or at a pressure in the range of 10 to 80 MPa. The treatment can also be performed at a temperature in the range of 32 to 250°C, or at a temperature in the range of 35 to 200°C.

[0067] Under the above-mentioned conditions, the raw material additives must be dissolved in the supercritical fluid, but the entire amount of the raw material additives does not have to be dissolved. Furthermore, the treatment using the supercritical fluid in the pressure vessel may be carried out under stirring as necessary. The stirring speed and stirring time can be appropriately set.

[0068] In this method using the slow expansion method, the decompression rate can be set appropriately. For example, the decompression rate can be set at a rate within the range of 0.005 to 15 MPa / s, or 0.01 to 10 MPa / s. Furthermore, by changing the decompression rate, this method can control the particle size of the resulting microparticles, and in the case of a nucleating agent, it can also control the crystallinity. The method according to this embodiment using the slow expansion method tends to produce microparticles with a larger average particle size than those obtained using the rapid expansion method.

[0069] The raw material additive used in the method for producing an additive for a resin molded product according to this embodiment has an average particle size of, for example, 0.5 μm or more. This method produces additive fine particles that are smaller than the average particle size of the raw material additive and have an average particle size of, for example, 5000 nm (5 μm) or less.

[0070] In another example, the raw material additive used in the method for producing an additive for a resin molded product according to this embodiment has an average particle size of 2 μm or more. This method produces additive fine particles with an average particle size of, for example, less than 2000 nm (2 μm).

[0071] In yet another example, the average particle size of the raw material additive used in the method for producing an additive for a resin molded product according to this embodiment is preferably in the range of 0.5 μm to 20,000 μm, more preferably in the range of 1 μm to 10,000 μm, and even more preferably in the range of 2 μm to 10,000 μm. This method produces additive fine particles that are smaller than the average particle size of the raw material additive and have an average particle size of preferably less than 2,000 nm, more preferably 1,500 nm or less.

[0072] In this specification, the average particle size refers to the average particle size of multiple particles (measured number: 30 or more) when the particles in a particle image observed by an electron microscope are regarded as rectangles, and the particle size is the longest diameter of the particles in the image. Here, when the particles are regarded as rectangles, the longest diameter refers to the length of the long side of the smallest rectangle circumscribing the particles in the image. The specific method for measuring the average particle size will be described later.

[0073] Furthermore, this method makes it possible to obtain additive fine particles whose average particle size is, for example, within the range of 1 to 99%, preferably 1 to 80%, and more preferably 1 to 50% of the average particle size of the raw additive.

[0074] <2> Masterbatch The masterbatch according to this embodiment is a masterbatch for use in resin molded products, and resin molded products such as resin layers are manufactured from a resin obtained by kneading this masterbatch with a second raw material resin described below.

[0075] The method for producing a masterbatch according to this embodiment includes obtaining additive particles by the method for producing an additive for a resin molded product described above, and kneading a raw material containing the additive particles and a first raw material resin. The masterbatch obtained by this method contains the additive particles and the first raw material resin.

[0076] Various resins can be used as the first raw material resin. Specific examples of the first raw material resin include polyolefin, polycarbonate, polystyrene, acrylic resins such as polymethyl methacrylate (PMMA), acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polyamides such as nylon 6 and nylon 66, polyacetal, polyphenylene ether, polyesters such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, liquid crystal polymers, polyphenylene sulfide, polyimide, polyamideimide, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyarylate, polyetherimide, fluororesin, polybutylene succinate, and polylactic acid. These resins may be used alone, or blends or alloys of two or more of these may be used.

[0077] Among these resins, for example, polyolefin, polycarbonate and acrylic resin are preferred from the viewpoints of transparency and durability, and polyolefin is preferred from the viewpoints of chemical resistance, durability and moldability.

[0078] In one embodiment, the first raw material resin is a resin (transparent resin) in which the proportion of polyolefin resin is in the range of 90 to 100 mass %.

[0079] Examples of polyolefin resins include polypropylene; polyethylene; polybutene; α-olefins (e.g., propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 4-ethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hex ... and copolymers of ethylene or alpha-olefins with other monomers, such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butyl acrylate copolymer.

[0080] The polyolefin resin is preferably a crystalline resin. The polyolefin resin is, for example, a polypropylene resin. The polyolefin resin is preferably a crystalline polypropylene resin.

[0081] The crystalline polypropylene resin may be a homopolymer, a copolymer such as a random copolymer or a block copolymer, or a mixture thereof. The polypropylene contained in the crystalline polypropylene resin may be isotactic polypropylene, syndiotactic polypropylene, or a combination thereof. Furthermore, in the crystalline polypropylene resin, the polypropylenes may have the same pentad fraction or may be a combination of polypropylenes with different pentad fractions. The crystalline polypropylene resin is preferably a propylene homopolymer having an isotactic pentad fraction (mmmm fraction) of 95% or more, more preferably an isotactic pentad fraction (mmmm fraction) of 96% or more, i.e., a highly crystalline homopolypropylene resin that is a homopolymer.

[0082] Here, the isotactic pentad fraction (mmmm fraction) is calculated from the electromagnetic wave absorption rate (EMR) value obtained by resonating a crystalline polypropylene resin at a predetermined resonance frequency using 13C-NMR (nuclear magnetic resonance) measurements using carbon (C) with a mass number of 13. The pentad fraction is related to the atomic arrangement, electronic structure, and molecular microstructure of the resin. The isotactic pentad fraction of a polypropylene resin is the proportion of a specific arrangement consisting of five propylene units, i.e., an arrangement in which all propylene units have the same configuration, as determined by 13C-NMR measurements. It is used as a measure of crystallinity or stereoregularity. The isotactic pentad fraction is one of the important factors that primarily determine the scratch resistance of the surface. Basically, the higher the isotactic pentad fraction, the higher the crystallinity of the sheet, resulting in improved scratch resistance.

[0083] The first raw resin may contain other resins in addition to the polyolefin resin. The other resins may be any resins that are highly compatible with the polyolefin resin. However, the proportion of the polyolefin resin in the resins contained in the masterbatch is preferably in the range of 90 to 100% by mass, as described above, and more preferably in the range of 95 to 100% by mass.

[0084] The masterbatch may contain one or more types of additive particles. In one embodiment, the amount (total amount) of the additives is preferably in the range of 0.005 to 5 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the first raw resin. The masterbatch may contain additives other than the additive particles nano-processed by the above-described method. In another embodiment, the amount (total amount) of the additive particles contained in the masterbatch is preferably in the range of 0.005 to 19% by mass, more preferably 0.05 to 19% by mass, and even more preferably 0.05 to 9% by mass, per 100 parts by mass of the first raw resin and all additives.

[0085] The total proportion of the first raw material resin and the additive fine particles in the masterbatch is preferably in the range of 90 to 100% by mass, and more preferably in the range of 95 to 100% by mass.

[0086] In the production of the masterbatch, the raw material additive is nano-sized to obtain additive fine particles by the above-mentioned method for producing an additive for resin molded products, and these additive fine particles are kneaded with a raw material containing the above-mentioned first raw material resin. This method makes it possible to obtain a masterbatch in which additive fine particles with small particle size variation are highly dispersed in the first raw material resin.

[0087] The raw material containing the additive fine particles and the first raw material resin is preferably kneaded in the presence of a supercritical fluid, in which the amount of the supercritical fluid per 100 parts by mass of the raw material is preferably in the range of 5 to 20 parts by mass.

[0088] The supercritical fluid may be, for example, carbon dioxide or nitrogen. The supercritical fluid is preferably carbon dioxide. Carbon dioxide becomes a supercritical fluid under conditions of 31.1°C or higher and 7.38 MPa or higher.

[0089] A supercritical fluid has a density close to that of a liquid and a diffusion coefficient close to that of a gas. The supercritical fluid easily impregnates the first raw resin in a molten state. Therefore, the supercritical fluid increases the fluidity of the first raw resin in a molten state.

[0090] If the fluidity of the raw material is low, attempting to sufficiently heat the raw material in an area away from the heater may result in the raw material being heated to an excessively high temperature in an area near the heater. Also, if the fluidity of the raw material is low, a large amount of frictional heat may be generated during kneading. As a result, discoloration of the resin, such as yellowing, may occur.

[0091] As described above, kneading in the presence of a supercritical fluid can increase the fluidity of the raw materials. This allows the raw materials to be heated uniformly and reduces the frictional heat generated during kneading. This prevents discoloration of the resin due to exposure to excessively high temperatures.

[0092] Furthermore, the supercritical fluid increases the fluidity of the first raw material resin in a molten state, and therefore the additive particles can be distributed in the first raw material resin with an even higher degree of dispersion.

[0093] The kneading may be carried out in a batch system or a continuous system, and for continuous kneading, for example, a kneading extruder can be used.

[0094] When a kneading extruder is used, for example, the raw materials are fed into the kneading extruder, and a supercritical fluid is supplied to the kneading extruder. Alternatively, the raw materials are fed into the kneading extruder, and a fluid is supplied to the kneading extruder, and a supercritical fluid is generated from the fluid within the kneading extruder. The pressure inside the kneading extruder is higher on the downstream side than on the upstream side. Therefore, a fluid such as a gas can be supplied to the kneading extruder, and the fluid can be converted into a supercritical fluid within the kneading extruder.

[0095] The kneading extruder used has, for example, an inlet for introducing the raw materials, an outlet for discharging a mixture obtained by kneading the raw materials, and a supply port provided between the inlet and the outlet. The supercritical fluid or gas is supplied to the kneading extruder from the supply port. As described above, the pressure inside the kneading extruder is higher on the downstream side than on the upstream side. When the supercritical fluid or gas is supplied to the kneading extruder from the supply port provided between the inlet and the outlet, a sufficient amount of supercritical fluid or gas can be supplied to the kneading extruder without interfering with the introduction of raw materials into the kneading extruder.

[0096] The kneading is carried out by setting the heater temperature preferably within the range of 180 to 240°C, more preferably within the range of 190 to 230°C. If the heater temperature is set too low, an extremely high pressure may be required to generate or maintain a supercritical state within the device, or, in the case of continuous kneading, the fluidity of the raw materials upstream may be insufficient. If the heater temperature is set too high, discoloration of the resin may occur.

[0097] <3> Resin and resin molded products The resin according to the embodiment of the present invention contains the masterbatch and a second raw material resin. This resin can be obtained by kneading the masterbatch obtained by the above-described method for producing a masterbatch with a raw material containing the second raw material resin. A resin molded product such as a resin layer, which will be described later, is manufactured from the resin obtained by this method.

[0098] Various resins can be used as the second raw material resin, and those described above for the first raw material resin used in the masterbatch can be used. The second raw material resin preferably has the same composition as the first raw material resin. For example, the first and second raw material resins may each be transparent resins in which the proportion of polyolefin resin is in the range of 90 to 100% by mass, and preferably are transparent resins of the same composition in which the proportion of polyolefin resin is in the range of 90 to 100% by mass.

[0099] The proportion of the masterbatch in the resin according to this embodiment is preferably in the range of 0.01 to 50% by mass, and more preferably in the range of 0.1 to 20% by mass.

[0100] The resin according to this embodiment can be used to manufacture a resin molded product. The resin molded product may have any shape. According to one example, the resin molded product is a resin layer, and the resin layer may be a transparent resin layer.

[0101] The resin layer preferably has a tensile modulus of elasticity in the range of 700 to 2000 MPa, more preferably in the range of 800 to 2000 MPa. The resin layer also preferably has a tensile elongation at break of 200% or more. The tensile elongation at break is, for example, 550% or less.

[0102] Here, the tensile elongation at break is a value that represents the elongation when a sample is pulled at a predetermined speed and breaks, and is the length of the sample at break (L) minus the length of the sample before the test (L0), divided by the length of the sample before the test (L0), expressed as a percentage. A sheet or film with an excessively small value is difficult to elongate and is therefore prone to cracking and whitening during post-processing such as V-groove bending.

[0103] The tensile modulus is a value calculated from the slope of the elastic region in which stress and strain are proportional to each other in the stress-strain curve obtained by the above-mentioned test for tensile elongation at break. A sheet or film with an excessively small modulus is too soft and is likely to cause poor appearance due to wrinkles, for example, when attached to a support. A sheet or film with an excessively large modulus is insufficient in flexibility and is likely to cause poor appearance due to wrinkles, for example, due to reduced adhesion to the support.

[0104] According to one example, the resin layer has a thickness in the range of 20 to 250 μm, and according to another example, the resin layer has a thickness in the range of 30 to 150 μm.

[0105] The resin layer may be one that can be handled by itself, or may be one of the layers contained in a laminate described below. The resin layer or laminate can be used for various products such as packaging materials, electronic components, and decorative sheets.

[0106] In one example, the concentration of the additive microparticles in the resin or resin molded product according to this embodiment is in the range of 0.005 to 1% by mass. As described above, the additive microparticles can be distributed with high dispersion in the resin or resin molded product, and even a small amount can achieve the significant effects required of the additive. Therefore, the additive concentration in the resin or resin molded product can be kept low. In this case, it is also possible to prevent bleed-out due to a high additive concentration in the resin or resin molded product.

[0107] <4> Laminate The laminate includes the resin layer and one or more other layers. The laminate may include the resin layer in any position. For example, a laminate including three or more layers may include the resin layer as one of the outermost layers or as an intermediate layer. The laminate may include only one of the resin layers, or may include multiple resin layers. Below, a decorative sheet will be described as an example of a laminate.

[0108] FIG. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention.

[0109] The decorative material 11 shown in FIG. 1 includes a substrate B and a decorative sheet 1 attached thereto. Here, the decorative material 11 is a decorative board. The decorative board may be a flat plate, or may be curved or folded. The decorative material 11 may have a shape other than a plate.

[0110] Here, the substrate B is a plate material. The plate material is, for example, a wood board, an inorganic board, a metal plate, or a composite board made of multiple materials. The substrate B may have a shape other than a plate.

[0111] Decorative sheet 1 is an example of a laminate containing a transparent resin layer as the resin layer. Decorative sheet 1 contains base fabric layer 2, design layer 3, transparent resin layer 4, surface protective layer 5, adhesive layer 7, primer layer 6, and concealing layer 8. The design layer 3, adhesive layer 7, transparent resin layer 4, and surface protective layer 5 are provided in this order from the base fabric layer 2 side on the surface of base fabric layer 2 opposite the surface facing substrate B. The concealing layer 8 and primer layer 6 are provided in this order from the base fabric layer 2 side on the surface of base fabric layer 2 facing substrate B. One or more of the design layer 3, surface protective layer 5, primer layer 6, adhesive layer 7, and concealing layer 8 may be omitted. The elements contained in decorative sheet 1 will be described below in order.

[0112] <4.1> Raw fabric layer The raw fabric layer 2 or its material can be selected arbitrarily from, for example, paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, metal foil, and the like.

[0113] Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane. Examples of nonwoven fabrics include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver.

[0114] When the raw fabric layer 2 contains a synthetic resin, it may further contain inorganic particles. Examples of inorganic particles include particles made of calcium carbonate, talc, or titanium oxide. When the raw fabric layer 2 contains inorganic particles, the non-flammability or flame retardancy of the decorative sheet 1 is improved.

[0115] <4.2> Primer layer When an olefin-based resin is used as the material of the raw fabric layer 2, the surface of the raw fabric layer 2 is often in an inactive state. Therefore, in this case, it is preferable to provide a primer layer 6 between the raw fabric layer 2 and the substrate B. When the raw fabric layer 2 is made of an olefin-based material, the primer layer 6 may be omitted, and the raw fabric layer 2 may be subjected to a surface modification treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, or dichromate treatment in order to improve the adhesion between the raw fabric layer 2 and the substrate B.

[0116] Materials that can be used for the primer layer 6 include, for example, the materials described below for the design layer 3. Since the primer layer 6 is applied to the back surface of the decorative sheet 1, and considering that the decorative sheet 1 will be wound up in web form, an inorganic filler may be added to the primer layer 6 to avoid blocking and increase adhesion to the adhesive. Examples of inorganic fillers include silica, alumina, magnesia, titanium oxide, and barium sulfate.

[0117] <4.3> Hidden layer To impart the decorative sheet 1 with the ability to conceal the substrate B, for example, a colored sheet can be used as the base layer 2, or an opaque concealing layer 8 can be provided. The concealing layer 8 can be made of, for example, the same material as that used for the design layer 3, which will be described later. However, since the purpose of the concealing layer 8 is to provide concealment, it is preferable to use, for example, an opaque pigment, titanium oxide, iron oxide, or the like, as the pigment. Furthermore, to enhance the concealing ability, metals such as gold, silver, copper, and aluminum can also be added to the material of the concealing layer 8. Generally, flake-shaped aluminum pieces are often added.

[0118] <4.4> Picture layer The design layer 3 is a layer formed by printing a design onto the base layer 2 using ink. Examples of ink binders include soluble nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyesters, and modified products thereof, either alone or in combination. The binder may be aqueous, solvent-based, or emulsion-based, and may be either a one-component type or a two-component type that includes a curing agent. The design layer 3 may be formed by curing a layer formed with a curable ink by exposure to ultraviolet light, electron beams, or the like. The most common method is to use a urethane-based ink that is cured with an isocyanate. The ink used to form the design layer 3 may further contain, in addition to the binder, pigments, colorants such as dyes, extender pigments, solvents, and various additives, which are commonly found in inks. Examples of versatile pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and pearl pigments such as mica.

[0119] In addition to applying ink, it is also possible to apply a design to the pattern layer 3 by vapor deposition or sputtering of various metals. In particular, it is preferable that a light stabilizer be added to the ink. This can suppress deterioration of the decorative sheet 1 itself caused by light degradation of the ink, and extend the life of the decorative sheet 1.

[0120] <4.5>Adhesive layer The adhesive layer 7 is also called a heat-sensitive adhesive layer, an anchor coat layer, or a dry lamination adhesive layer.

[0121] The resin material for the adhesive layer 7 is not particularly limited, and may be appropriately selected from acrylic, polyester, polyurethane, epoxy, and other resin materials. Alternatively, an ethylene-vinyl acetate copolymer resin adhesive may be used as the resin material for the adhesive layer 7. The coating method may be appropriately selected depending on the viscosity of the adhesive. Generally, gravure coating is used, and the adhesive layer 7 is formed on the upper surface of the design layer 3 by gravure coating, followed by lamination of the transparent resin layer 4. The adhesive layer 7 may be omitted if sufficient adhesive strength is obtained between the transparent resin layer 4 and the design layer 3.

[0122] <4.6>Transparent resin layer The transparent resin layer 4 is the transparent resin layer described in detail above. Here, the transparent resin layer 4 has a flat upper surface. The upper surface of the transparent resin layer 4 may be provided with an uneven structure. Methods for providing an uneven structure on the upper surface of the transparent resin layer 4 include, for example, a method of applying heat and pressure while pressing an embossing plate against the upper surface of the transparent resin layer 4 that has been laminated to another layer by various methods, and a method of using a cooling roll having an uneven structure on its surface when forming the transparent resin layer 4 using an extruder. When an uneven structure is provided on the upper surface of the transparent resin layer 4, it is also possible to further improve the design by filling the recesses with ink.

[0123] <4.7>Surface protective layer The surface protective layer 5 is a colorless and transparent resin layer. Here, an uneven structure is provided on the upper surface of the surface protective layer 5. The upper surface of the surface protective layer 5 may also be flat.

[0124] The surface protection layer 5 contains a cured resin. This resin is, for example, a thermosetting resin, an ionizing radiation curable resin, or a combination thereof. The resin may be, for example, aqueous, emulsion, solvent-based, or solventless. Here, "ionizing radiation" refers to charged particle beams such as electron beams. Ionizing radiation curable resins are cured by irradiation with ionizing radiation. Ionizing radiation curable resins can also be cured by irradiation with ultraviolet light.

[0125] As the thermosetting resin, a two-component curing urethane-based thermosetting resin is preferably used. Urethane-based thermosetting resins are suitable from the viewpoints of workability, cost, and the cohesive strength of the resin itself. As the urethane-based resin, a resin obtained by reacting an acrylic polyol with an isocyanate may be used. The isocyanate may be appropriately selected from, for example, tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), bis(isocyanatomethyl)cyclohexane (HXDI), and trimethylhexamethylene diisocyanate (TMDI); their derivatives such as adducts, biuret compounds, and isocyanurates; and prepolymers thereof. In consideration of weather resistance, it is preferable to use a material based on hexamethylene diisocyanate (HMDI) or isophorone diisocyanate (IPDI), which have a linear molecular structure.

[0126] As the ionizing radiation curable resin, known materials such as various monomers and commercially available oligomers can be used, for example, acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins can be used. The ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin. The acrylic resin can be appropriately selected from, for example, polyester acrylate resins, epoxy acrylate resins, urethane acrylate resins, and acrylic acrylate resins. In particular, it is preferable to use urethane acrylate resins or acrylic acrylate resins, which have good weather (light) resistance. From the viewpoint of workability, it is preferable to cure the ionizing radiation curable resin with active energy rays such as ultraviolet rays or electron beams.

[0127] As the mixture of thermosetting resin and ionizing radiation curable resin, it is preferable to use a mixture of a urethane resin as a thermosetting resin obtained by reacting an acrylic polyol with an isocyanate, and a urethane acrylate resin as a photocurable resin, which is particularly advantageous in terms of improving surface hardness, suppressing cure shrinkage, and adhesion to inorganic fine particles.

[0128] The surface protective layer 5 may further include inorganic particles. Examples of the inorganic particles include particles made of alumina, silica, boehmite, iron oxide, magnesium oxide, or diamond. The average particle size of the inorganic particles is, for example, in the range of 1 to 100 μm, and in another example, in the range of 1 to 30 μm.

[0129] The inorganic particle content of the surface protective layer 5 is, for example, in the range of 0.1 to 30 parts by mass, and in another example, in the range of 1 to 20 parts by mass, per 100 parts by mass of the resin component. Inclusion of inorganic particles in the surface protective layer 5 improves its scratch resistance. However, excessively high inorganic particle content may reduce transparency due to the light scattering effect of the inorganic particles, or may result in increased costs.

[0130] The surface protective layer 5 can be formed by known methods. A surface protective layer 5 having a concave-convex structure on its upper surface can be formed by forming a coating film made of an ionizing radiation-curable resin, followed by a first irradiation step in which the coating film is irradiated with light having a wavelength of 200 nm or less (first radiation), and a second irradiation step in which the coating film is irradiated with ionizing radiation such as electron beams or ultraviolet light having a longer wavelength than the first radiation as the second radiation, in that order. Alternatively, the surface protective layer 5 having a concave-convex structure on its upper surface can be formed by forming a coating film made of an ionizing radiation-curable resin or a thermosetting resin, pressing a plate against the coating film, curing the coating film in this state, and then removing the plate from the cured film. A leaf surface protective layer having a flat upper surface can be formed by forming a coating film made of an ionizing radiation-curable resin or a thermosetting resin and curing the coating film. The coating film can be formed by various printing methods such as gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and ink jet printing, and various coating methods such as roll coating, knife coating, microgravure coating, and die coating. [Example]

[0131] The following describes examples of the present invention. [1] Test Example 1 <Example 101> (Production of additive fine particles) Additive microparticles were prepared using a rapid expansion method as follows. A powdered phosphate metal salt nucleating agent (ADK STAB (registered trademark) NA-11, average particle size 2.67 μm, manufactured by ADEKA Corporation) was prepared as a raw material additive. It was confirmed in advance that NA-11 was soluble in carbon dioxide according to the procedure described above.

[0132] This raw material additive was placed in a high-pressure stainless steel vessel (volume: 500 mL) in an amount of 1% (w / v) of the vessel's volume and sealed, and carbon dioxide was injected to bring the pressure to 30 MPa to create a supercritical state. The temperature inside the vessel was 40°C. The vessel was kept at a temperature of 40°C and a pressure of 30 MPa for 10 minutes or more, and the fluid was sprayed through a nozzle under atmospheric pressure to obtain additive microparticles with an average particle size of 940 nm.

[0133] (Masterbatch manufacturing) Next, a masterbatch containing the above-mentioned additive fine particles and a polyolefin resin was produced by the following method. The polyolefin resin used was a highly crystalline homopolypropylene resin with an isotactic pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g / 10 min (230 °C), and a molecular weight distribution (MWD; Mw / Mn) of 2.3. To this polyolefin resin, 10,000 ppm of the additive microparticles obtained above, 500 ppm of a hindered phenol-based antioxidant (Irganox® 1010, manufactured by BASF), 20,000 ppm of a benzotriazole-based UV absorber (Tinuvin® 328, manufactured by BASF), and 20,000 ppm of a hindered amine-based light stabilizer (Chimasorb® 944, manufactured by BASF) were added. The amounts expressed in ppm are the mass proportions of each additive based on the total weight of the polyolefin resin and all additives.

[0134] The raw material obtained by adding the above additives to the polyolefin resin was kneaded using a kneading extruder equipped with a strand die at the discharge port. Here, the heater temperature was set at 230°C. After kneading, the strands discharged through the strand die were cooled and then cut to obtain a masterbatch.

[0135] (Manufacturing transparent resin sheets) A transparent resin sheet was produced using the masterbatch and polyolefin resin. The polyolefin resin used was the same highly crystalline homopolypropylene resin as that used in the production of the masterbatch. 10 parts by mass of the masterbatch was added to 100 parts by mass of this polyolefin resin, and 500 ppm of a hindered phenol-based antioxidant (Irganox (registered trademark) 1010: manufactured by BASF) was further added. The mixture was then extruded using a melt extruder to form a transparent resin sheet with a thickness of 80 μm as a transparent resin layer. Next, both sides of the transparent resin sheet were subjected to a corona treatment to set the surface wetting tension to 40 dyn / cm or more.

[0136] (Decorative sheet manufacturing) A decorative sheet was manufactured using the above transparent resin sheet. Specifically, first, a base fabric layer having a thickness of 70 μm and having hiding properties was prepared. Next, a pattern was printed on one side of the base fabric layer using a two-component curing urethane ink (V180: manufactured by Toyo Ink Co., Ltd.) to form a design layer. A primer coat was applied to the other side of the base fabric layer to form a primer layer. Next, the base fabric layer and the above transparent resin sheet were bonded together by dry lamination so that the design layer faced the transparent resin layer. In this dry lamination, a dry lamination adhesive (Takelac (registered trademark) A540: manufactured by Mitsui Chemicals, Inc.) was applied at 2 g / m 2 Next, the upper surface of the transparent resin sheet was pressed using an embossing die roll to create a concave-convex structure. After that, a two-component curing urethane top coat (W184: manufactured by DIC Graphics Corporation) was applied to the transparent resin sheet at a coating amount of 3 g / m. 2 The coating was then cured to form a surface protective layer. In this way, a decorative sheet having a thickness of 154 μm was obtained.

[0137] <Example 102> In this example, additive fine particles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that in the production of the masterbatch, raw materials containing polyolefin resin and additive fine particles were kneaded in the presence of supercritical carbon dioxide as shown below. The average particle size of the additive fine particles produced in this example was 940 nm.

[0138] The raw materials were mixed in the presence of supercritical carbon dioxide as follows. That is, the raw materials containing the polyolefin resin and the additive fine particles were mixed using a kneading extruder equipped with a strand die at the discharge port and a fluid supply device at the intermediate position of the kneading section, while carbon dioxide was supplied from the fluid supply device to the kneading extruder. Here, the heater temperature was set to 230°C, the pressure at the intermediate position of the kneading section was 8 MPa, and the amount of carbon dioxide per 100 parts by mass of raw materials was 6 parts by mass. The strands discharged through the strand die were cooled and then cut to obtain a masterbatch.

[0139] <Example 103> In this example, additive fine particles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that the slow expansion method was used instead of the rapid expansion method in the production of additive fine particles. The average particle size of the additive fine particles produced in this example was 1180 nm.

[0140] The additive fine particles were produced using the slow expansion method as follows. The raw material additive NA-11 was placed in a 500 mL high-pressure stainless steel vessel equipped with a stirring blade, in an amount of 1% (w / v) of the vessel's volume, and sealed. Carbon dioxide was then injected to a pressure of 30 MPa to create a supercritical state. The mixture was stirred at 300 rpm at 60°C and maintained at 30 MPa for 30 minutes. The carbon dioxide was then removed at a rate of 1 MPa / s, and the pressure was reduced to atmospheric pressure, yielding additive microparticles with an average particle size of 1180 nm in the vessel.

[0141] <Example 104> In this example, an additive, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that the concentration of the additive fine particles in the production of the masterbatch was changed from 10,000 ppm to 100,000 ppm.

[0142] <Example 105> In this example, an additive, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that the concentration of the additive fine particles in the production of the masterbatch was changed from 10,000 ppm to 30,000 ppm.

[0143] <Example 106> In this example, an additive, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that the concentration of the additive fine particles in the production of the masterbatch was changed from 10,000 ppm to 1,000 ppm.

[0144] <Example 107> In this example, an additive, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that the concentration of the additive fine particles in the production of the masterbatch was changed from 10,000 ppm to 100 ppm.

[0145] <Example 108> In this example, additive fine particles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that a phosphorus-based antioxidant (Irgafos (registered trademark) 168, average particle size 2.49 μm, manufactured by BASF) was used instead of the nucleating agent NA-11. The average particle size of the additive fine particles produced in this example was 580 nm.

[0146] <Example 109> In this example, additive fine particles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 103, except that a phosphorus-based antioxidant (Irgafos (registered trademark) 168, average particle size 2.49 μm, manufactured by BASF) was used instead of the nucleating agent NA-11. The average particle size of the additive fine particles produced in this example was 1820 nm.

[0147] <Comparative Example 101> In this example, a master batch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 101, except that the nano-processing of the nucleating agent raw material NA-11 was omitted.

[0148] <Comparative Example 102> In this example, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 108, except that the nano-processing of the antioxidant Irgafos 168 was omitted.

[0149] <Comparative Example 103> In this example, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 108, except that the antioxidant Irgafos 168 was not used.

[0150] [2] Test Example 2 <Example 201> (Manufacturing of additive fine particles) Additive microparticles were prepared using a rapid expansion method as follows. As raw material additives, NA-11, a phosphate ester metal salt-based nucleating agent used in Test Example 1, and Irgafos 168, a phosphorus-based antioxidant, were prepared. These raw material additives were placed in a high-pressure stainless steel container (volume: 500 mL) in an amount of 0.5% (w / v) of each based on the volume of the container and sealed, and carbon dioxide was injected to create a supercritical state at a pressure of 30 MPa. The temperature inside the container was 40°C at this time. The temperature inside the container was kept at 40°C and the pressure was 30 MPa for 10 minutes or more, and a fluid was sprayed through a nozzle under atmospheric pressure to obtain additive microparticles with an average particle size of 620 nm.

[0151] (Masterbatch manufacturing) Next, a masterbatch containing the above-mentioned additive fine particles and a polyolefin resin was produced by the following method. The polyolefin resin used was a highly crystalline homopolypropylene resin with an isotactic pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g / 10 min (230 °C), and a molecular weight distribution (MWD; Mw / Mn) of 2.3. To this polyolefin resin, 20,000 ppm of the additive microparticles obtained above, 500 ppm of a hindered phenol-based antioxidant (Irganox® 1010, manufactured by BASF), 20,000 ppm of a benzotriazole-based UV absorber (Tinuvin® 328, manufactured by BASF), and 20,000 ppm of a hindered amine-based light stabilizer (Chimasorb® 944, manufactured by BASF) were added. The amount expressed in ppm is the mass ratio of each additive based on the total amount of the polyolefin resin and all additives.

[0152] The raw material obtained by adding the above additives to the polyolefin resin was kneaded using a kneading extruder equipped with a strand die at the discharge port. Here, the heater temperature was set at 230°C. After kneading, the strands discharged through the strand die were cooled and then cut to obtain a masterbatch.

[0153] (Manufacturing transparent resin sheets) A transparent resin sheet was produced using the masterbatch and polyolefin resin. The polyolefin resin used was the same highly crystalline homopolypropylene resin as that used in the production of the masterbatch. 10 parts by mass of the masterbatch was added to 100 parts by mass of this polyolefin resin, and 500 ppm of a hindered phenol-based antioxidant (Irganox (registered trademark) 1010: manufactured by BASF) was further added. The mixture was then extruded using a melt extruder to form a transparent resin sheet with a thickness of 80 μm as a transparent resin layer. Next, both sides of the transparent resin sheet were subjected to a corona treatment to set the surface wetting tension to 40 dyn / cm or more.

[0154] (Decorative sheet manufacturing) A decorative sheet was manufactured using the above transparent resin sheet. Specifically, first, a base fabric layer having a thickness of 70 μm and having hiding properties was prepared. Next, a pattern was printed on one side of the base fabric layer using a two-component curing urethane ink (V180: manufactured by Toyo Ink Co., Ltd.) to form a design layer. A primer coat was applied to the other side of the base fabric layer to form a primer layer. Next, the base fabric layer and the above transparent resin sheet were bonded together by dry lamination so that the design layer faced the transparent resin layer. In this dry lamination, a dry lamination adhesive (Takelac (registered trademark) A540: manufactured by Mitsui Chemicals, Inc.) was applied at 2 g / m 2 Next, the upper surface of the transparent resin sheet was pressed using an embossing die roll to create a concave-convex structure. After that, a two-component curing urethane top coat (W184: manufactured by DIC Graphics Corporation) was applied to the transparent resin sheet at a coating amount of 3 g / m. 2 The coating was then cured to form a surface protective layer. In this way, a decorative sheet having a thickness of 154 μm was obtained.

[0155] <Example 202> In this example, additive fine particles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 201, except that the slow expansion method was used instead of the rapid expansion method in the production of additive fine particles. The average particle size of the additive fine particles produced in this example was 1200 nm.

[0156] The additive fine particles were produced using the slow expansion method as follows. The raw material additives NA-11 and Irgafos 168 were placed in a 500 mL high-pressure stainless steel vessel equipped with a stirring blade, each in an amount of 0.5% (w / v) of the vessel's volume, and sealed. Carbon dioxide was then injected to a pressure of 30 MPa to create a supercritical state. The mixture was stirred at 300 rpm at 60°C and maintained at 30 MPa for 30 minutes. The carbon dioxide was then removed at a rate of 1 MPa / s, and the pressure was reduced to atmospheric pressure, yielding additive microparticles with an average particle size of 1200 nm in the vessel.

[0157] <Example 203> In this example, additive microparticles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 202, except that in the production of additive microparticles, the surfactant N-lauroyl sarcosine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used instead of the phosphorus-based antioxidant Irgafos 168. The average particle size of the additive microparticles produced in this example was 700 nm.

[0158] <Example 204> In this example, additive fine particles, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 202, except that the surfactant N-lauroyl sarcosine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used instead of the phosphate ester metal salt nucleating agent NA-11 in the production of additive fine particles. The average particle size of the additive fine particles produced in this example was 900 nm.

[0159] <Example 205> In this example, a master batch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 202, except that in producing additive fine particles, three types of raw material additives were used as shown below.

[0160] (Production of additive fine particles) Three raw additives were prepared: NA-11, a phosphate metal salt-based nucleating agent; Irgafos 168, a phosphorus-based antioxidant; and N-lauroyl sarcosine, a surfactant. These raw additives were placed in a 500 mL high-pressure stainless steel vessel equipped with a stirring blade, each at 0.5% (w / v) of the vessel's volume. The vessel was sealed, and carbon dioxide was injected to a pressure of 30 MPa to create a supercritical state. The mixture was stirred at 60°C and 300 rpm, and maintained at 30 MPa for 30 minutes. The carbon dioxide was then removed at a rate of 1 MPa / s, and the vessel was depressurized to atmospheric pressure, yielding additive microparticles with an average particle size of 520 nm.

[0161] <Example 206> In this example, in the production of additive microparticles, the phosphate ester metal salt nucleating agent NA-11 and the phosphorus-based antioxidant Irgafos 168 were separately subjected to supercritical treatment and then mixed, and this mixture was used to produce the master batch. A master batch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 201, except that, as shown below, in the production of additive microparticles, the phosphate ester metal salt nucleating agent NA-11 and the phosphorus-based antioxidant Irgafos 168 were separately subjected to supercritical treatment and then mixed, and this mixture was used to produce the master batch.

[0162] (Manufacturing of additive fine particles) A phosphate metal salt nucleating agent, NA-11, was placed in a high-pressure stainless steel vessel (volume: 500 mL) in an amount of 1% (w / v) of the vessel's volume and sealed. Carbon dioxide was then injected to create a supercritical state at a pressure of 30 MPa. The temperature inside the vessel was 40°C. The vessel was maintained at a temperature of 40°C and a pressure of 30 MPa for 10 minutes or more, and the fluid was sprayed through a nozzle at atmospheric pressure to obtain additive microparticles with an average particle size of 940 nm.

[0163] Next, the phosphorus-based antioxidant Irgafos 168 was placed in a high-pressure stainless steel vessel (volume: 500 mL) in an amount of 1% (w / v) of the vessel's volume and sealed, and carbon dioxide was injected to create a supercritical state at a pressure of 30 MPa. The temperature inside the vessel was 40°C at this time. The vessel was kept at a temperature of 40°C and a pressure of 30 MPa for 10 minutes or more, and the fluid was sprayed through a nozzle at atmospheric pressure to obtain additive microparticles with an average particle size of 580 nm.

[0164] The additive microparticles obtained from NA-11 and the additive microparticles obtained from Irgafos 168 were mixed in the same mass ratio and stirred to obtain additive microparticles with an average particle size of 760 nm.

[0165] <Example 207> In this example, the additive, masterbatch, transparent resin sheet and decorative sheet were produced in the same manner as in Example 203, except that in the production of additive microparticles, the amount of N-lauroyl sarcosine added to the high-pressure stainless steel vessel was changed from 0.5% (w / v) to 0.15% (w / v), and in the production of the masterbatch, the concentration of additive microparticles was changed from 20,000 ppm to 130,000 ppm.

[0166] <Example 208> In this example, the additive, masterbatch, transparent resin sheet and decorative sheet were produced in the same manner as in Example 203, except that the concentration of additive fine particles in the production of the masterbatch was changed from 20,000 ppm to 60,000 ppm.

[0167] <Example 209> In this example, the additive, masterbatch, transparent resin sheet and decorative sheet were produced in the same manner as in Example 203, except that the concentration of additive fine particles in the production of the masterbatch was changed from 20,000 ppm to 2,000 ppm.

[0168] <Example 210> In this example, an additive, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 203, except that the concentration of the additive fine particles in the production of the masterbatch was changed from 20,000 ppm to 200 ppm.

[0169] <Comparative Example 201> In this example, the master batch, transparent resin sheet, and decorative sheet were produced in the same manner as in Example 201, except that the nano-processing of the phosphate ester metal salt nucleating agent NA-11 and the phosphorus-based antioxidant Irgafos 168 was omitted, and a mixture obtained by mixing and stirring NA-11 and Irgafos 168 in the same mass ratio was used to produce the master batch.

[0170] <Comparative Example 202> In this example, a masterbatch, a transparent resin sheet, and a decorative sheet were produced in the same manner as in Example 203, except that the nano-processing of the phosphate ester metal salt nucleating agent NA-11 and the surfactant N-lauroyl sarcosine was omitted, and a mixture obtained by mixing and stirring NA-11 and N-lauroyl sarcosine in the same mass ratio was used to produce the masterbatch.

[0171] <Comparative Example 203> In this example, the master batch, transparent resin sheet, and decorative sheet were produced in the same manner as in Example 204, except that the nano-processing of the phosphorus-based antioxidant Irgafos 168 and the surfactant N-lauroyl sarcosine was omitted, and a mixture obtained by mixing and stirring Irgafos 168 and N-lauroyl sarcosine in the same mass ratio was used to produce the master batch.

[0172] <Evaluation of additives> (Measurement of average particle size) The raw material additives used in Examples 101 to 109, Examples 201 to 210, Comparative Examples 101 to 103, and Comparative Examples 201 to 203, and the additive microparticles obtained in Examples 101 to 109 and Examples 201 to 210, were observed using a scanning electron microscope SU8020 (manufactured by Hitachi High-Technologies Corporation), and the average particle diameters were measured as follows.

[0173] First, the additive particles or raw material additives were placed on a carbon support tape. Then, the additive particles or raw material additives were platinum coated. This prepared the sample for electron microscope observation. The prepared sample was placed in the observation chamber. Observation was carried out at a magnification of 5000 times, and the part of the observation screen where the additive particles or raw material additives accounted for 75% or more was saved as an image. Then, a 100 μm 2 All particle sizes within this range were measured and the average value was calculated. 2 If there are fewer than 30 particles in the image, increase the observation range by 100 μm until the number of particles reaches 30 or more. 2 The image was expanded in increments of 1 / 2, and the particle diameters of 30 or more particles were measured. Here, the particle diameter refers to the longest diameter when the particles present in the image are considered as rectangles, in other words, the length of the long side of the smallest rectangle circumscribing the particles present in the image. Note that for Examples 201 to 210 and Comparative Example 201, in which two or three raw material additives were used, the particle diameters of the particles observed in the image were measured without distinguishing between the types. Furthermore, for Comparative Examples 202 and 203, the average particle diameters of NA-11 or Irgafos 168 before mixing the two raw material additives were measured.

[0174] <Evaluation of transparent resin sheets> (Evaluation of bleed-out properties) The transparent resin sheet was left at room temperature for one week after production. Two 5 cm x 5 cm pieces were then cut from the transparent resin sheet, and one of the pieces was placed in an oven at 80°C ± 3°C and heated for one hour. These sheets were then immersed in 10 mL of methanol for 15 minutes, and the additives that had bled out onto the surface of the sheet were extracted or dispersed in the methanol. This methanol solution was quantitatively analyzed using high-performance liquid chromatography (HPLC). The amount of additive or its decomposition product detected in the HPLC analysis was evaluated as "bleed out" if the amount of bleed out of the heated sheet was 1.5 times or more the amount of bleed out of the unheated sheet, and evaluated as "no bleed out" if the amount was less than 1.5 times.

[0175] (Tensile test) Test pieces for tensile tests were cut from the transparent resin sheet using a Super Dumbbell Cutter (manufactured by Dumbbell Co., Ltd.) conforming to JIS K-7127 Type 4 test pieces. The obtained test pieces were set in a tensile testing machine (manufactured by Tensilon Co., Ltd.) and pulled at a pulling rate of 50 mm / min. The ratio of the length of the test piece just before it broke to the length before the test was calculated as the tensile breaking elongation. Furthermore, the tensile modulus was calculated from the slope of the stress-strain curve obtained in the test in the elastic region where stress and strain are proportional.

[0176] (Haze value measurement test) The haze value referred to here is a value obtained by subtracting the ratio of the amount of parallel transmitted light, which is the sum of the amount of linear components of the light rays emitted from one side of an object, to the amount of total incident light (parallel transmittance), from the ratio of the total transmitted light, which is the sum of the amount of all light rays emitted from the other side of the object, to the amount of total incident light (total transmittance), when light emitted from an incandescent light source is incident on one side of the object, and dividing the result (diffuse transmittance) by the total light transmittance, expressed as a percentage. The smaller the haze value of an object, the higher the transparency of the object.

[0177] The haze value of an object made of a transparent resin is determined by internal haze, which depends on the internal state of the object, such as the degree of crystallinity in the crystalline portion and the size of the spherulite, and external haze, which depends on the surface state of the object, such as the presence or absence of irregularities on the entrance and exit surfaces. In this specification, when simply referring to the haze value, it means a value determined by the internal haze and external haze.

[0178] Here, the haze value measurement test was performed on each transparent resin sheet using a haze value measurement tester (NDH2000: manufactured by Nippon Denshoku Industries Co., Ltd.). Specifically, first, a blank measurement was performed with nothing attached to the sample holder. Next, a sample transmittance measurement was performed with the transparent resin sheet attached to the sample holder as a sample. Then, the ratio of the value obtained by the sample transmittance measurement to the value obtained by the blank measurement was calculated as a percentage, and the haze value was calculated from these transmittances.

[0179] <Evaluation of decorative sheets> (Pencil hardness test) Pencils with lead hardnesses of 2B, B, HB, F, H, 2H, and 3H were prepared. The tip of the pencil lead was placed against the upper surface of the surface protection layer of the decorative sheet, and the angle formed by the pencil's longitudinal direction was fixed at 45±1°. A load of 1 kg was applied to the pencil, and it was then slid to determine whether scratches were formed on the decorative sheet (in accordance with the old JIS standard JISK5400). The test was performed in ascending order of hardness with the pencil, and the hardness at which a scratch was first formed was taken as the surface hardness of the decorative sheet.

[0180] (V-groove bending process suitability test) A medium-density fiberboard (MDF) was prepared as the substrate. Next, a decorative sheet was attached to one side of the substrate using a urethane adhesive to produce a decorative material. Next, a groove with a V-shaped cross section (V-groove) was formed on the other side of the substrate attached to the substrate. This V-groove was formed so that its bottom reached the boundary between the substrate and the decorative sheet and so as not to scratch the decorative sheet. Next, the decorative material was folded at a 90° angle along the V-groove so that the decorative sheet side formed a mountain fold. The mountain fold of the decorative sheet was then observed with an optical microscope to check for defects such as whitening or cracks at the mountain fold, and post-processability was evaluated according to the following criteria. A: No defects such as whitening or cracks were observed. B: Defects such as whitening and cracks were observed.

[0181] (weather resistance) Each transparent resin sheet was subjected to a carbon arc weather resistance test in accordance with JIS B 7753 using a weather resistance tester (Sunshine Weather Meter, manufactured by Suga Test Instruments Co., Ltd.). The test was conducted under the condition of a weather resistance time of 4000 hours. The change in appearance of each transparent resin sheet before and after the weather resistance test was evaluated based on the following criteria. Evaluation B indicates that the sheet satisfies the weather resistance required for applications such as decorative sheets. A: No change at all. B: No whitening or cracks, but some loss of gloss and fading. C: Whitening, cracks, or partial destruction or breakage.

[0182] <Evaluation results> The results of the above evaluations are summarized in Tables 1 to 3. [Table 1] [Table 2] [Table 3]

[0183] [Discussion: Test Example 1] As shown in Table 1, it can be seen that, compared to Comparative Example 101, which did not undergo nano-processing of the nucleating agent, Examples 101 to 107, which underwent nano-processing using the rapid expansion method or the slow expansion method, had smaller average particle sizes and better nucleating agent particles. It can be seen that the transparent resin layers of Examples 101 to 107, which used these nucleating agent particles, suppressed bleed-out compared to Comparative Example 101, which experienced bleed-out. Furthermore, the transparent resin layers of Examples 101 to 107, which used these nucleating agent particles, had lower haze and better transparency than the transparent resin layer of Comparative Example 101. Furthermore, the transparent resin layers of Examples 101 to 107, which used these nucleating agent particles, had significantly higher tensile elongation at break than the transparent resin layer of Comparative Example 101, exceeding 200%, thereby improving post-processability. This is presumably because the absence of coarse particles in the transparent resin layers of Examples 101 to 107 reduces stress concentration, improving tensile elongation at break and thereby improving post-processability.

[0184] Furthermore, compared to Example 101, in which no supercritical fluid was injected during the production of the masterbatch, Example 102, in which a supercritical fluid was injected, had a lower haze and better transparency in the transparent resin layer. This shows that producing the masterbatch in the presence of a supercritical fluid enables the nucleating agent particles to be distributed in the resin with a higher degree of dispersion without agglomeration, thereby reducing the haze in the transparent resin layer and improving transparency.

[0185] As shown in Table 2, it can be seen that, compared to Comparative Example 102, which did not undergo nano-processing of the antioxidant, Examples 108 and 109, which underwent nano-processing using the rapid expansion method or the slow expansion method, had smaller average particle sizes and better antioxidant microparticles were obtained. It can be seen that the transparent resin layers of Examples 108 and 109, which used these antioxidant microparticles, showed less bleed-out than Comparative Example 102, which showed bleed-out. Furthermore, the decorative sheets of Examples 108 and 109, which used these antioxidant microparticles, showed improved weather resistance compared to the decorative sheet of Comparative Example 102.

[0186] [Discussion: Test Example 2] Table 3 shows that Test Example 2, in which two or more additives were nano-processed, also yielded results similar to those of Test Example 1, in which only one additive was nano-processed. That is, compared to Comparative Examples 201 to 203, in which multiple additives were not nano-processed, Examples 201 to 210, in which multiple additives were nano-processed using the rapid expansion method or the slow expansion method, yielded fine additive particles with smaller average particle diameters. The transparent resin layers of Examples 201 to 210, which used these fine additive particles, showed reduced bleed-out compared to Comparative Examples 201 to 203, in which bleed-out occurred. Furthermore, the transparent resin layers of Examples 201 to 203 and 205 to 210, which contained nucleating agent fine particles, had tensile elongation at break significantly higher than 200% compared to the transparent resin layers of Comparative Examples 201 and 202, demonstrating improved post-processability. It is also apparent that the decorative sheets of Examples 201, 202, 205 and 206, which contain antioxidant fine particles, have improved weather resistance compared to the decorative sheets of Comparative Examples 201 and 203.

[0187] Furthermore, it can be seen that additive microparticles with a smaller average particle size were obtained in Example 201, where the same two raw material additives were nano-processed simultaneously, i.e., where the two raw material additives were nano-processed as a mixture, compared to Example 206, where two raw material additives were nano-processed separately. The transparent resin layer of Example 201, which used these additive microparticles, had a higher tensile elongation at break than the transparent resin layer of Example 206. This is presumably because, when multiple raw material additives are nano-processed simultaneously as a mixture, the microparticles inhibit each other from aggregating when precipitated from the supercritical fluid. As a result of the suppression of aggregation of the precipitated additive microparticles, additive microparticles with a smaller average particle size are obtained than when the additives are nano-processed individually without such aggregation suppression, and the tensile elongation at break of the transparent resin layer using these microparticles is also even higher.

[0188] Furthermore, compared to Example 202, in which the phosphate ester metal salt nucleating agent NA-11 and the phosphorus-based antioxidant Irgafos 168 were simultaneously nano-processed, Example 203, in which Irgafos 168 was replaced with the surfactant N-lauroyl sarcosine, and Example 205, in which the surfactant N-lauroyl sarcosine was further added, showed that good additive microparticles with a smaller average particle size were obtained. This shows that mixing a surfactant with other raw additives and simultaneously nano-processing them is particularly effective in reducing the average particle size of the resulting additive microparticles.

[0189] Furthermore, it can be seen that Example 205, in which three types of raw material additives were simultaneously subjected to nano-processing, produced additive fine particles with the smallest average particle size compared to Examples 201 to 204 and 206, in which any two types of raw material additives selected from the three types were simultaneously subjected to nano-processing. It is presumed that the effect of suppressing aggregation of each additive when the raw material fine particles are precipitated from the supercritical fluid is greater when three types of raw material additives are used than when two types are used. [Explanation of symbols]

[0190] 1...decorative sheet, 2...base layer, 3...pattern layer, 4...transparent resin layer, 5...surface protection layer, 6...primer layer, 7...adhesive layer, 8...hiding layer, 11...decorative material, B...base material.

Claims

1. A method for producing an additive for a resin molded product, comprising reducing the pressure of a fluid containing a supercritical fluid and a raw material additive soluble in the supercritical fluid to precipitate an additive having a smaller average particle size than the raw material additive.

2. 2. The method for producing an additive for a resin molded product according to claim 1, wherein the fluid is decompressed in a pressure-resistant container.

3. 2. The method for producing an additive for a resin molded product according to claim 1, wherein the step of decompressing the fluid includes spraying the fluid from inside the pressure-resistant container to the outside of the pressure-resistant container.

4. 2. The method for producing an additive for a resin molded product according to claim 1, wherein the raw material additive has an average particle size of 2 μm or more, and the additive having a smaller average particle size than the raw material additive has an average particle size of less than 2000 nm.

5. The method for producing an additive for a resin molded product according to claim 1, wherein the additive is a nucleating agent.

6. 2. The method for producing an additive for a resin molded product according to claim 1, wherein the additive is a plastic decomposition inhibitor.

7. 2. The method for producing an additive for a resin molded product according to claim 1, wherein the supercritical fluid comprises carbon dioxide.

8. Producing the additive by the method for producing an additive for a resin molded product according to any one of claims 1 to 7; kneading a first raw material resin and a raw material containing the additive; A method for producing a masterbatch comprising:

9. The method for producing a masterbatch according to claim 8, wherein the raw materials are kneaded in the presence of a supercritical fluid.

10. The method for producing a masterbatch according to claim 8, wherein the first raw material resin is a resin in which the proportion of polyolefin resin is in the range of 90 to 100 mass %.

11. Producing the masterbatch by the method for producing the masterbatch according to claim 8; kneading the master batch and a raw material containing a second raw material resin; A method for producing a resin comprising the steps of:

12. The method for producing a resin according to claim 11, wherein the first raw resin and the second raw resin are each independently a resin having a polyolefin resin content in the range of 90 to 100% by mass.

13. Producing the resin by the resin producing method according to claim 11; molding the resin to produce a resin molded product; A method for manufacturing a resin molded product comprising the steps of:

14. The method for producing a resin molded product according to claim 13, wherein the concentration of the additive in the resin molded product is set to be within a range of 0.005 to 1% by mass.

15. The method for producing a resin molded product according to claim 13, wherein the resin molded product is a resin layer.

16. forming the resin layer by the method for producing a resin molded product according to claim 15; laminating one or more other layers on the resin layer; A method for producing a laminate comprising the steps of:

17. The method for producing a laminate according to claim 16, wherein the laminate is a decorative sheet.

18. A resin molding additive obtained by the method for producing an additive for resin molding according to any one of claims 1 to 7.

19. A masterbatch obtained by the method for producing a masterbatch according to claim 8.

20. A resin molded product obtained by the method for producing a resin molded product according to claim 13.

21. A resin layer obtained by the method for producing a resin molded article according to claim 15.

22. A laminate obtained by the method for producing a laminate according to claim 16.

23. 23. The laminate according to claim 22, which is a decorative sheet.

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