Vinyl chloride-based resin composition, vinyl chloride-based resin molded body, and composite particles

Abstract

Provided is a vinyl chloride-based resin composition with which it is possible to enhance the dispersibility of composite particles that include particles of a sodium salt of an aliphatic carboxylic acid, to enhance the thermal stability during heating and molding of the vinyl chloride-based resin composition, and to enhance the impact resistance of a molded body thereof.　A vinyl chloride-based resin composition according to the present invention contains a vinyl chloride-based resin, an organic tin-based stabilizer, and composite particles. In the volume-based particle size distribution of the composite particles, the particle diameter D50 is 3.0 μm to 30 μm, and the particle diameter D99 is 15 μm to 250 μm. The composite particles each include a particle main body and a surface treatment material that is disposed on the surface of the particle main body. The material of the particle main body is a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material is a fatty acid or a salt thereof.

Description

Vinyl chloride resin composition, vinyl chloride resin molded body and composite particles

[0001] The present invention relates to a vinyl chloride resin composition containing a vinyl chloride resin and particles of a sodium salt of an aliphatic carboxylic acid. The present invention also relates to a vinyl chloride resin molded article using the vinyl chloride resin composition. The present invention also relates to composite particles containing particles of a sodium salt of an aliphatic carboxylic acid.

[0002] Vinyl chloride resins have excellent mechanical strength, weather resistance, heat resistance, and chemical resistance, and are therefore processed into various molded articles such as pipes, plates, and containers, and are used in many fields.

[0003] However, when a molded article is obtained using a vinyl chloride resin, stable molding may be difficult because the vinyl chloride resin has low thermal stability and is prone to thermal decomposition due to the elimination of hydrogen chloride during heat molding of the vinyl chloride resin composition, which may result in a decrease in mechanical strength of the molded article or discoloration of the molded article.

[0004] Furthermore, in order to enhance the thermal stability of vinyl chloride resins, heat stabilizers are sometimes used together with vinyl chloride resins. Known examples of such heat stabilizers include tin-based stabilizers, lead-based stabilizers, calcium-zinc-based stabilizers, barium-zinc-based stabilizers, and barium-cadmium-based stabilizers.

[0005] Patent Document 1 discloses a vinyl chloride resin composition containing a vinyl chloride copolymer and an organotin compound that is liquid at 23° C. The vinyl chloride copolymer contained in the vinyl chloride resin composition is a copolymer of a vinyl chloride monomer and a second monomer that has a polyalkylene glycol group and an alkyl ether skeleton or an allyl ether skeleton at one end. In the vinyl chloride resin composition, the content of the organotin compound is 3 parts by weight or more per 100 parts by weight of the vinyl chloride copolymer.

[0006] Patent Document 2 discloses a halogen-containing polymer stabilizing composition containing an alkali metal salt of adipic acid and an alkali metal salt of a carboxylic acid having 1 to 22 carbon atoms. Patent Document 2 describes polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (C-PVC) as halogen-containing polymers. The stabilizing composition may be used in combination with a conventional heat stabilizer.

[0007] JP 2017-165868 A EP 2363431 A1

[0008] In Patent Document 1, an organotin compound is used to suppress thermal decomposition of a vinyl chloride resin, thereby improving the thermal stability of the vinyl chloride resin composition to some extent. In Patent Document 2, a specific stabilizing composition is used to improve the thermal stability of a vinyl chloride resin composition to some extent.

[0009] However, when an organotin compound is used as in Patent Document 1, hydrogen chloride generated during heat molding of a vinyl chloride-based resin composition cannot be sufficiently captured, resulting in a problem of insufficient thermal stability of the vinyl chloride-based resin composition. Furthermore, the hydrogen chloride may corrode the metal surface of a mold or the like. As a result, there is a problem that long-term production of molded articles using the vinyl chloride-based resin composition is difficult.

[0010] Furthermore, the melting point of the alkali metal salt of a fatty acid as described in Patent Document 2 may be higher than the processing temperature range (up to about 200°C) of a vinyl chloride resin composition, and the alkali metal salt of a fatty acid may remain in a solid state during processing of the vinyl chloride resin composition. Furthermore, particles of the alkali metal salt of a fatty acid tend to form aggregates. Therefore, when obtaining a vinyl chloride resin composition, it is difficult to disperse the alkali metal salt of a fatty acid well in the vinyl chloride resin, and it is difficult to sufficiently enhance the thermal stability of the obtained vinyl chloride resin composition during heat molding.

[0011] Furthermore, in the case of conventional vinyl chloride resin compositions containing alkali metal salts of fatty acids, the impact resistance of molded articles obtained by molding the vinyl chloride resin compositions may be reduced.

[0012] An object of the present invention is to provide a vinyl chloride resin composition that can improve the dispersibility of composite particles comprising particles of a sodium salt of an aliphatic carboxylic acid, can improve the thermal stability of the vinyl chloride resin composition during heat molding, and can improve the impact resistance of molded articles. Another object of the present invention is to provide a vinyl chloride resin molded article using the vinyl chloride resin composition. Another object of the present invention is to provide composite particles that can improve the dispersibility of composite particles comprising particles of a sodium salt of an aliphatic carboxylic acid, can improve the thermal stability of a composition using the composite particles during heat molding, and can improve the impact resistance of molded articles.

[0013] This specification discloses the following vinyl chloride resin composition, vinyl chloride resin molded article, and composite particles.

[0014] Item 1. A vinyl chloride resin composition comprising a vinyl chloride resin, an organotin stabilizer, and composite particles, wherein the composite particles have a particle size distribution on a volume basis in which the particle size D50 is 3.0 μm or more and 30 μm or less and a particle size D99 is 15 μm or more and 250 μm or less, the composite particles comprising a particle body and a surface treatment material disposed on the surface of the particle body, the material of the particle body being a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material being a fatty acid or a salt thereof.

[0015] Item 2. The vinyl chloride resin composition according to Item 1, wherein the content of the composite particles is 0.10 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0016] Item 3. The vinyl chloride resin composition according to Item 1 or 2, wherein the sodium salt of an aliphatic carboxylic acid includes disodium adipate.

[0017] Item 4. The vinyl chloride resin composition according to any one of Items 1 to 3, wherein the content of the surface treatment material derived from the composite particles and contained in the vinyl chloride resin composition is 0.3 parts by weight or more and 6.0 parts by weight or less per 100 parts by weight of the particle bodies derived from the composite particles and contained in the vinyl chloride resin composition.

[0018] Item 5. The vinyl chloride resin composition according to any one of Items 1 to 4, wherein the fatty acid or salt thereof includes stearic acid or a salt thereof.

[0019] Item 6. The vinyl chloride resin composition according to any one of Items 1 to 5, wherein when the composite particles are added to water to obtain an aqueous dispersion containing 5 wt % of the composite particles, the pH of the aqueous dispersion is 6.5 or more and 7.8 or less.

[0020] Item 7. The vinyl chloride resin composition according to any one of Items 1 to 6, wherein the amount of the organotin stabilizer is 0.10 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0021] Item 8. The vinyl chloride resin composition according to any one of Items 1 to 7, wherein the organotin stabilizer includes a tin mercapto stabilizer.

[0022] Item 9. The vinyl chloride resin composition according to any one of Items 1 to 8, wherein the composite particles have an aspect ratio of 1.00 or more and 1.7 or less.

[0023] Item 10. The vinyl chloride resin composition according to any one of Items 1 to 9, wherein the particle diameter D50 of the composite particles is 3.0 μm or more and 20 μm or less, and the particle diameter D99 of the composite particles is 25 μm or more and 250 μm or less.

[0024] Item 11. The vinyl chloride resin composition according to any one of Items 1 to 10, which is a vinyl chloride resin composition for injection molding.

[0025] Item 12. A vinyl chloride resin molded article, which is a molded article of the vinyl chloride resin composition according to any one of Items 1 to 11.

[0026] Item 13. Composite particles having a particle size distribution on a volume basis in which the particle size D50 is 3.0 μm or more and 30 μm or less and the particle size D99 is 15 μm or more and 250 μm or less, the composite particles comprising a particle body and a surface treatment material disposed on the surface of the particle body, the material of the particle body being a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material being a fatty acid or a salt thereof.

[0027] Item 14. The composite particles according to Item 13, wherein the content of the surface treatment material is 0.3 parts by weight or more and 6.0 parts by weight or less relative to 100 parts by weight of the particle body.

[0028] Item 15. The composite particles according to Item 13 or 14, which are used in combination with a vinyl chloride resin.

[0029] Item 16. The composite particles according to Item 13 or 14, which are used in combination with a vinyl chloride resin and an organotin stabilizer.

[0030] Item 17. The composite particles according to any one of Items 13 to 16, wherein the particle diameter D50 of the composite particles is 3.0 μm or more and 20 μm or less, and the particle diameter D99 of the composite particles is 25 μm or more and 250 μm or less.

[0031] The vinyl chloride resin composition according to the present invention comprises a vinyl chloride resin, an organotin stabilizer, and composite particles. In the vinyl chloride resin composition according to the present invention, the composite particles have a particle size distribution on a volume basis in which the particle diameter D50 is 3.0 μm or more and 30 μm or less and the particle diameter D99 is 15 μm or more and 250 μm or less. In the vinyl chloride resin composition according to the present invention, the composite particles comprise a particle body and a surface treatment material disposed on the surface of the particle body. In the vinyl chloride resin composition according to the present invention, the material of the particle body is a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material is a fatty acid or a salt thereof. Because the vinyl chloride resin composition according to the present invention has the above-described configuration, the dispersibility of composite particles comprising particles of a sodium salt of an aliphatic carboxylic acid can be improved, the thermal stability of the vinyl chloride resin composition during heat molding can be improved, and the impact resistance of molded articles can be enhanced.

[0032] The composite particles according to the present invention have a particle size distribution on a volume basis in which the particle diameter D50 is 3.0 μm or more and 30 μm or less, and a particle diameter D99 is 15 μm or more and 250 μm or less. The composite particles according to the present invention comprise a particle body and a surface treatment material disposed on the surface of the particle body. In the composite particles according to the present invention, the material of the particle body is a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material is a fatty acid or a salt thereof. Because the composite particles according to the present invention have the above configuration, the dispersibility of the composite particles comprising particles of a sodium salt of an aliphatic carboxylic acid can be improved, the thermal stability of a composition using the composite particles during heat molding can be improved, and the impact resistance of the molded body can be improved.

[0033] Fig. 1 is a cross-sectional view schematically showing a composite particle according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing a composite particle according to a second embodiment of the present invention. Fig. 3 is a perspective view of cheese used for evaluation.

[0034] The present invention will be described in detail below.

[0035] (Vinyl chloride resin composition and composite particles) The vinyl chloride resin composition according to the present invention comprises a vinyl chloride resin, an organotin stabilizer, and composite particles. In the vinyl chloride resin composition according to the present invention, the composite particles have a particle size distribution on a volume basis in which the particle diameter D50 is 3.0 μm or more and 30 μm or less and the particle diameter D99 is 15 μm or more and 250 μm or less. In the vinyl chloride resin composition according to the present invention, the composite particles comprise a particle body and a surface treatment material disposed on the surface of the particle body. In the vinyl chloride resin composition according to the present invention, the material of the particle body is a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material is a fatty acid or a salt thereof. In the vinyl chloride resin composition according to the present invention, the particle body is a particle of a sodium salt of an aliphatic carboxylic acid.

[0036] Furthermore, the composite particles according to the present invention have a particle size distribution on a volume basis in which the particle diameter D50 is 3.0 μm or more and 30 μm or less, and a particle diameter D99 is 15 μm or more and 250 μm or less. The composite particles according to the present invention comprise a particle body and a surface treatment material disposed on the surface of the particle body. In the composite particles according to the present invention, the material of the particle body is a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material is a fatty acid or a salt thereof. In the composite particles according to the present invention, the particle body is a particle of a sodium salt of an aliphatic carboxylic acid.

[0037] Vinyl chloride resin compositions using conventional organotin stabilizers have the problem of insufficient thermal stability. Furthermore, hydrogen chloride can corrode metal surfaces such as molds, making long-term production of molded articles difficult. Furthermore, depending on the amount of organotin stabilizer added, the heat resistance of the vinyl chloride resin composition can be reduced.

[0038] In order to improve the thermal stability of vinyl chloride resin compositions, it has been considered to use an alkali metal salt of a fatty acid together with an organotin stabilizer. However, the melting point of the alkali metal salt of a fatty acid may be higher than the processing temperature range of the vinyl chloride resin composition (up to approximately 200°C), and the alkali metal salt of a fatty acid may remain solid during processing of the vinyl chloride resin composition. Furthermore, particles of the alkali metal salt of a fatty acid tend to aggregate. Therefore, when obtaining a vinyl chloride resin composition, it is difficult to disperse the alkali metal salt of a fatty acid well in the vinyl chloride resin, and it is difficult to sufficiently improve the thermal stability of the obtained vinyl chloride resin composition during heat molding.

[0039] In order to disperse the particles of the alkali metal salt of a fatty acid well in a vinyl chloride resin, it has been considered to reduce the particle size of the particles of the alkali metal salt of a fatty acid. However, simply reducing the particle size of the particles of the alkali metal salt of a fatty acid results in aggregation of the particles during storage, reducing handleability. This may require work to break up the aggregates. Furthermore, when obtaining a vinyl chloride resin composition, it becomes difficult to weigh out a predetermined amount of particles of the alkali metal salt of a fatty acid, and the dispersibility of the particles of the alkali metal salt of a fatty acid in the vinyl chloride resin composition also decreases. Furthermore, the physical properties of the obtained vinyl chloride resin composition, such as thermal stability during heat molding, may vary, and the content of the alkali metal salt of a fatty acid particles may vary in molded articles obtained by molding the vinyl chloride resin composition.

[0040] Furthermore, when conventional particles of an alkali metal salt of a fatty acid are aggregated, a large force is required to break down the aggregates, which also makes it difficult to disperse the particles of an alkali metal salt of a fatty acid well in a vinyl chloride resin.

[0041] The vinyl chloride resin composition according to the present invention has the above-described configuration, which can improve the dispersibility of composite particles containing sodium salt particles of aliphatic carboxylic acid and can also improve the thermal stability of the vinyl chloride resin composition during heat molding. Therefore, the physical properties of the vinyl chloride resin composition, such as thermal stability, during heat molding are less likely to vary, and molded articles obtained by molding the vinyl chloride resin composition are less likely to have variation in the content of alkali metal salt particles of fatty acid. As a result, the mechanical strength of the resulting molded articles can be improved, and discoloration of the vinyl chloride resin molded articles can be prevented.

[0042] Furthermore, since the composite particles according to the present invention have the above-described configuration, the dispersibility of the composite particles containing the sodium salt of an aliphatic carboxylic acid can be improved, and the thermal stability of a composition using the composite particles during heat molding can be improved. As a result, the physical properties of the composition using the composite particles, such as the thermal stability during heat molding, are less likely to vary, and the content of the alkali metal salt of a fatty acid particles in the molded article obtained by molding the composition is less likely to vary. As a result, the mechanical strength of the obtained molded article can be increased, and discoloration of the molded article can be prevented.

[0043] In the vinyl chloride resin composition according to the present invention, particles of the sodium salt of an aliphatic carboxylic acid are not used alone, but are used in the form of composite particles comprising particles of the sodium salt of an aliphatic carboxylic acid. Furthermore, the composite particles according to the present invention are not simply particles of the sodium salt of an aliphatic carboxylic acid, but are in the form of composite particles comprising particles of the sodium salt of an aliphatic carboxylic acid. These specific composite particles have low agglomeration properties, and even if they aggregate, the aggregates are easily disintegrated by small forces such as mixing. Therefore, in the present invention, the composite particles can be easily dispersed uniformly, significantly improving the production efficiency of compositions containing the composite particles (such as vinyl chloride resin compositions). Furthermore, the production efficiency of compositions such as vinyl chloride resin compositions can be significantly improved by facilitating the weighing of a predetermined amount of composite particles when obtaining the composition. Furthermore, since the composite particles are easily dispersed in the composition in a non-agglomerated state, the quality uniformity of the composition can be improved, and the quality uniformity of molded articles obtained by molding the composition can be improved.

[0044] Furthermore, in the case of conventional vinyl chloride resin compositions containing alkali metal salts of fatty acids, the impact resistance of molded articles obtained by molding the vinyl chloride resin compositions may be reduced.

[0045] The vinyl chloride resin composition according to the present invention and the composite particle according to the present invention have the above-described configuration, and therefore can improve the impact resistance of a molded article. Specifically, when an impact is applied perpendicular to the main surface of the molded article, the impact resistance (impact strength) of the molded article can be improved. Furthermore, even if the molded article has a complex shape, when an impact is applied to the molded article having a complex shape, the impact resistance (fracture suppression ability) can be improved.

[0046] Furthermore, the vinyl chloride resin composition according to the present invention can inhibit corrosion of the surface of metals such as molds. For example, corrosion of the surface of a mold used in molding the vinyl chloride resin composition can be inhibited. As a result, vinyl chloride resin molded articles can be produced over a long period of time. Furthermore, when the vinyl chloride resin composition and the resulting vinyl chloride resin molded article come into contact with metal, corrosion of the metal can be inhibited.

[0047] Furthermore, the vinyl chloride resin composition according to the present invention can improve the heat resistance of the molded article obtained. Because the vinyl chloride resin composition according to the present invention has the above-mentioned features, discoloration of the molded article obtained by molding the vinyl chloride resin composition according to the present invention can be suppressed even when exposed to high temperatures.

[0048] In the vinyl chloride resin composition according to the present invention and the composite particle according to the present invention, the particle size D50 is preferably 3.0 μm or more and 25 μm or less, and more preferably 3.0 μm or more and 20 μm or less. In the vinyl chloride resin composition according to the present invention and the composite particle according to the present invention, the particle size D99 is preferably 20 μm or more and 250 μm or less, and more preferably 25 μm or more and 250 μm or less. In particular, in the vinyl chloride resin composition according to the present invention and the composite particle according to the present invention, the particle size D50 is preferably 3.0 μm or more and 25 μm or less, and the particle size D99 is preferably 20 μm or more and 250 μm or less, and more preferably 3.0 μm or more and 20 μm or less, and the particle size D99 is preferably 25 μm or more and 250 μm or less. In these cases, the above-mentioned effects of the present invention can be exhibited even more effectively. In particular, the dispersibility of composite particles comprising particles of sodium salts of aliphatic carboxylic acids can be further improved, the thermal stability of compositions using the composite particles during heat molding can be further improved, and the impact resistance of molded bodies can be further improved.

[0049] The vinyl chloride resin composition is preferably used to obtain a vinyl chloride resin molded article. The vinyl chloride resin composition is preferably used to obtain an injection-molded vinyl chloride resin molded article. The vinyl chloride resin composition is preferably injection molded. The vinyl chloride resin composition is preferably a vinyl chloride resin composition for injection molding. The vinyl chloride resin molded article is preferably a vinyl chloride resin injection molded article.

[0050] The composite particles are preferably used in a mixture with a vinyl chloride resin (use of the composite particles in a vinyl chloride resin composition containing a vinyl chloride resin). The composite particles are preferably used in a mixture with a vinyl chloride resin and an organotin stabilizer (use of the composite particles in a vinyl chloride resin composition containing a vinyl chloride resin and an organotin stabilizer). The composite particles are preferably used to obtain a molded product (such as a vinyl chloride resin molded product) (use of the composite particles in a molded product (such as a vinyl chloride resin molded product)). The molded product is preferably an injection molded product (such as an injection vinyl chloride resin molded product) (use of the composite particles in an injection molded product (such as an injection vinyl chloride resin molded product)).

[0051] Hereinafter, each component contained in the vinyl chloride resin composition and the composite particles will be described in detail.

[0052] <Vinyl chloride resin> The vinyl chloride resin has chlorine atoms. The vinyl chloride resin may be a chlorinated vinyl chloride resin or a non-chlorinated vinyl chloride resin. From the viewpoint of improving heat resistance, the vinyl chloride resin is preferably a chlorinated vinyl chloride resin. The chlorinated vinyl chloride resin is a resin obtained by chlorinating a vinyl chloride resin. Only one type of the vinyl chloride resin may be used, or two or more types may be used in combination.

[0053] Examples of the vinyl chloride resin include a homopolymer of a vinyl chloride monomer, and a copolymer of a vinyl chloride monomer and a vinyl monomer copolymerizable with the vinyl chloride monomer.

[0054] Examples of vinyl monomers copolymerizable with the vinyl chloride monomer include vinyl esters such as vinyl acetate, vinyl propionate, and vinyl ether; cyano group-containing compounds such as acrylonitrile; halogen compounds such as vinylidene chloride and vinyl fluoride; olefins such as ethylene and propylene; carboxyl group-containing compounds such as itaconic acid, maleic acid, and fumaric acid; non-aromatic carboxylic acid anhydrides such as maleic anhydride; acrylic acid esters such as methyl methacrylate and ethyl methacrylate; and imide compounds such as maleimide. Only one type of the vinyl monomer may be used, or two or more types may be used in combination.

[0055] The polymerization method of the vinyl chloride monomer or the polymerization method of the vinyl chloride monomer and the vinyl monomer is not particularly limited. Examples of the polymerization method include suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization, and precipitation polymerization. From the viewpoint of efficiently obtaining a vinyl chloride resin, the polymerization method is preferably suspension polymerization, emulsion polymerization, solution polymerization, or precipitation polymerization.

[0056] The chlorinated vinyl chloride resin is preferably obtained by polymerizing the vinyl chloride monomer or the vinyl chloride monomer and the vinyl monomer to obtain a vinyl chloride resin, and then chlorinating the vinyl chloride resin.

[0057] The method for chlorinating the vinyl chloride resin is not particularly limited. Examples of the method for chlorinating the vinyl chloride resin include a method in which the vinyl chloride resin is placed in an aqueous solvent to obtain a suspension, and then chlorine is added to react the vinyl chloride resin with chlorine. This chlorination reaction proceeds under heating conditions or light irradiation conditions.

[0058] From the viewpoint of enhancing the thermal stability of the resulting chlorinated vinyl chloride resin, the chlorination reaction is preferably carried out under heating conditions.

[0059] From the viewpoint of increasing the efficiency of the chlorination reaction, the temperature during the heating is preferably 80°C or higher and preferably 140°C or lower.

[0060] The chlorine content of the vinyl chloride resin is preferably 56.8% by weight or more and preferably 72% by weight or less. The chlorine content of the vinyl chloride resin is the content of chlorine atoms in 100% by weight of the vinyl chloride resin. When the chlorine content of the vinyl chloride resin is equal to or more than the lower limit, the heat resistance of the obtained molded article can be further improved. When the chlorine content of the vinyl chloride resin is equal to or less than the upper limit, the moldability of the composition can be improved, and the impact resistance and surface smoothness of the obtained molded article can be improved.

[0061] When the vinyl chloride resin is a chlorinated vinyl chloride resin, the chlorine content of the chlorinated vinyl chloride resin is preferably 56.8% by weight or more, more preferably 60% by weight or more, even more preferably 61.5% by weight or more, and preferably 72% by weight or less, more preferably 67.5% by weight or less. When the chlorine content of the chlorinated vinyl chloride resin is equal to or greater than the lower limit, the heat resistance of the obtained molded article can be further improved. When the chlorine content of the chlorinated vinyl chloride resin is equal to or less than the upper limit, the moldability of the composition can be improved, and the impact resistance and surface smoothness of the obtained molded article can be improved.

[0062] The chlorine content of the vinyl chloride resin (when the vinyl chloride resin is a chlorinated vinyl chloride resin, the chlorine content of the chlorinated vinyl chloride resin) can be determined by potentiometric titration in accordance with JIS K7229.

[0063] The average degree of polymerization of the vinyl chloride resin is preferably 500 or more, more preferably 600 or more, and preferably 2000 or less, more preferably 1400 or less. When the average degree of polymerization is equal to or greater than the lower limit, the mechanical strength of the molded article can be increased. When the average degree of polymerization is equal to or less than the upper limit, it is not necessary to raise the temperature during molding of the composition, and the moldability of the composition can be improved.

[0064] The average degree of polymerization of the vinyl chloride resin can be measured as follows: The vinyl chloride resin is dissolved in tetrahydrofuran (THF), filtered to remove unnecessary components, and the THF in the filtrate is dried to remove the resulting resin. The average degree of polymerization of the vinyl chloride resin is measured using the resin as a sample in accordance with JIS K6721 "Testing Methods for Vinyl Chloride Resins."

[0065] The content of the vinyl chloride resin in 100% by weight of the vinyl chloride resin composition is preferably 70% by weight or more, more preferably 80% by weight or more, even more preferably 85% by weight or more, particularly preferably 90% by weight or more, and most preferably 92% by weight or more, and is preferably 99.8% by weight or less, more preferably 99% by weight or less, even more preferably 98.5% by weight or less, particularly preferably 98% by weight or less, and most preferably 97% by weight or less. When the content of the vinyl chloride resin is at least the above lower limit, the adhesive strength and mechanical strength of the obtained molded article can be increased. When the content of the vinyl chloride resin is at most the above upper limit, it is not necessary to raise the temperature during molding of the composition, and the moldability of the composition can be improved.

[0066] The vinyl chloride resin contained in the vinyl chloride resin composition is preferably in the form of particles. In the particle size distribution of the particulate vinyl chloride resin particles on a volume basis, the particle size D50 is preferably 0.1 μm or more and preferably 500 μm or less. When the particle size D50 of the vinyl chloride resin particles is equal to or greater than the lower limit, the handleability can be improved. When the particle size D50 of the vinyl chloride resin particles is equal to or less than the upper limit, the moldability of the composition can be improved.

[0067] The particle size D50 of the vinyl chloride resin particles is the average diameter measured on a volume basis, and is the median diameter (D50) value at 50%. The particle size D50 of the vinyl chloride resin particles can be measured by laser diffraction / scattering or the like. The particle size D50 of the vinyl chloride resin particles is the diameter value corresponding to 50% of the particle size distribution on a volume basis, calculated from the smaller particle size side, and is the particle size (D50) value at which the cumulative distribution value is 50%. A laser diffraction particle size distribution analyzer is preferably used as the measuring device. Commercially available laser diffraction particle size distribution analyzers include the "Microtrac MT3300EXII" manufactured by Microtrac Bell. When using the "Microtrac MT3300EXII" manufactured by Microtrac Bell, isopropanol (IPA) can be used as the dispersion medium.

[0068] <Organotin-Based Stabilizer> The vinyl chloride resin composition contains an organotin-based stabilizer. The organotin-based stabilizer suppresses thermal decomposition of the vinyl chloride resin and also captures hydrogen chloride generated during thermal decomposition of the vinyl chloride resin.

[0069] The organotin stabilizer is preferably an organotin heat stabilizer.

[0070] Examples of the organotin stabilizer include tin mercapto stabilizers, tin malate stabilizers, and tin carboxylate stabilizers. Examples of the tin mercapto stabilizers include monoalkyltin mercapto, dialkyltin mercapto, monoalkyltin mercapto polymers, dialkyltin mercapto polymers, monoalkyltin mercapto sulfides, and dialkyltin mercapto sulfides. Examples of the tin malate stabilizers include monoalkyltin maleates, dialkyltin maleates, monoalkyltin maleate polymers, and dialkyltin maleate polymers. Examples of the tin carboxylate stabilizers include monoalkyltin carboxylates and dialkyltin carboxylates. The organotin stabilizers may be used alone or in combination of two or more.

[0071] From the viewpoints of further improving the thermal stability of the composition during heat molding, preventing initial discoloration of the resulting molded body, and further increasing the heat resistance of the molded body, the above-mentioned organotin-based stabilizer preferably contains a tin mercapto-based stabilizer, more preferably contains a dialkyltin mercapto, and even more preferably contains dioctyltin mercapto.

[0072]

[0033] The content of the organotin stabilizer in 100% by weight of the vinyl chloride resin composition is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, even more preferably 0.3% by weight or more, particularly preferably 0.5% by weight or more, and most preferably 0.7% by weight or more, and is preferably 5.0% by weight or less, more preferably 4.5% by weight or less, even more preferably 4.0% by weight or less, even more preferably 3.5% by weight or less, particularly preferably 2.8% by weight or less, and most preferably 1.8% by weight or less. When the content of the organotin stabilizer is at least the above lower limit and is at most the above upper limit, the thermal stability of the composition during hot molding can be more effectively improved, and the heat resistance of the obtained molded article can be further improved.

[0073] The content of the organotin stabilizer relative to 100 parts by weight of the vinyl chloride resin in the vinyl chloride resin composition is preferably 0.10 parts by weight or more, more preferably 0.3 parts by weight or more, even more preferably 0.5 parts by weight or more, particularly preferably 0.7 parts by weight or more, and is preferably 4.0 parts by weight or less, more preferably 3.5 parts by weight or less, even more preferably 3.0 parts by weight or less, particularly preferably 2.5 parts by weight or less, and most preferably 1.5 parts by weight or less. When the content of the organotin stabilizer is at least the above-mentioned lower limit and is at most the above-mentioned upper limit, the thermal stability of the composition during hot molding can be more effectively improved, and the heat resistance of the obtained molded article can be further improved.

[0074] The vinyl chloride resin composition may contain a stabilizer other than the organotin stabilizer. Examples of stabilizers other than the organotin stabilizer include lead-based stabilizers, calcium-zinc-based stabilizers, barium-zinc-based stabilizers, and barium-cadmium-based stabilizers. Examples of the lead-based stabilizers include tribasic lead sulfate, tetrabasic lead sulfate, basic lead sulfite, dibasic lead phosphite, dibasic lead phthalate, tribasic lead maleate, dibasic lead stearate, and basic sulfite-phosphite.

[0075] <Composite Particles> The vinyl chloride resin composition includes composite particles. The composite particles include a particle body and a surface treatment material disposed on the surface of the particle body. The material of the particle body is a sodium salt of an aliphatic carboxylic acid. The material of the surface treatment material is a fatty acid or a salt thereof. The material of the surface treatment material may be a fatty acid or a salt of a fatty acid. From the viewpoint of further improving the thermal stability of the vinyl chloride resin composition during heat molding and the heat resistance and impact resistance of the resulting molded body, it is preferable that the material of the surface treatment material is a fatty acid. The particle body is a particle of a sodium salt of an aliphatic carboxylic acid. The composite particles are composite particles in which the surface of the particle body is surface-treated with the surface treatment material. The surface treatment material is used to surface-treat the particle body.

[0076] The present invention will be specifically described below with reference to the drawings.

[0077] FIG. 1 is a cross-sectional view schematically showing a composite particle according to a first embodiment of the present invention.

[0078] 1 is a first composite particle comprising particles (coated particles). Composite particle 1 comprises a particle body 2 and a surface treatment material 3A disposed on the surface of particle body 2. In composite particle 1, surface treatment material 3A is a plurality of particles (coated particles).

[0079] In the composite particle 1, the surface treatment material 3A covers at least a part of the surface of the particle body 2. The composite particle 1 is a composite particle in which the surface of the particle body 2 is covered with the surface treatment material 3A (plural particles).

[0080] FIG. 2 is a cross-sectional view schematically showing a composite particle according to a second embodiment of the present invention.

[0081] 2 is a second composite particle having a layer (coating layer). The composite particle 10 has a particle body 2 and a surface treatment material 3B disposed on the surface of the particle body 2. In the composite particle 10, the surface treatment material 3B is a layer (coating layer).

[0082] In the composite particle 10, the surface treatment material 3B covers the surface of the particle body 2. The composite particle 10 is a composite particle in which the surface of the particle body 2 is covered with the surface treatment material 3B (layer).

[0083] The material of the particle body (particles of sodium salt of aliphatic carboxylic acid) is a sodium salt of aliphatic carboxylic acid. The sodium salt of aliphatic carboxylic acid contains sodium. Specifically, the sodium salt of aliphatic carboxylic acid contains at least one sodium. The aliphatic carboxylic acid in the sodium salt of aliphatic carboxylic acid may be a monocarboxylic acid or a polycarboxylic acid. The polycarboxylic acid may be a dicarboxylic acid.

[0084] The sodium salt of the aliphatic carboxylic acid neutralizes the hydrogen chloride generated during the decomposition of vinyl chloride resin with sodium, thereby inhibiting corrosion of metal surfaces such as molds caused by hydrogen chloride, thereby enabling the long-term production of vinyl chloride resin molded articles.

[0085] Examples of the sodium salts of aliphatic carboxylic acids include disodium adipate, disodium sebacate, disodium azelaate, disodium suberate, and disodium pimelate. The sodium salts of aliphatic carboxylic acids may be used alone or in combination of two or more.

[0086] From the viewpoint of more effectively suppressing corrosion of the surface of a metal such as a mold, the number of sodium atoms in the sodium salt of the aliphatic carboxylic acid is preferably two or more, and more preferably 2. The number of sodium atoms in the sodium salt of the aliphatic carboxylic acid may be 5 or less, 4 or less, or 3 or less.

[0087] From the viewpoint of further increasing the thermal stability of the composition during heat molding and further increasing the heat resistance and impact resistance of the obtained molded article, the number of carbon atoms in the sodium salt of the aliphatic carboxylic acid is preferably 4 or more, more preferably 5 or more, even more preferably 6 or more, and is preferably 16 or less, more preferably 12 or less, even more preferably 8 or less.

[0088] From the viewpoints of further improving the dispersibility of the composite particles, further improving the thermal stability of the composition during heat molding, and further improving the heat resistance and impact resistance of the resulting molded body, it is preferred that the number of COONa groups in the sodium salt of the aliphatic carboxylic acid is 2 and that the number of carbon atoms in the sodium salt of the aliphatic carboxylic acid is from 6 to 16. From the viewpoints of further improving the dispersibility of the composite particles, further improving the thermal stability of the composition during heat molding, and further improving the heat resistance and impact resistance of the resulting molded body, it is preferred that the sodium salt of the aliphatic carboxylic acid has a chain hydrocarbon skeleton having from 2 to 14 carbon atoms.

[0089] Examples of the sodium salt of an aliphatic carboxylic acid having the above-mentioned preferred embodiment include disodium adipate, disodium sebacate, disodium azelaate, disodium suberate, and disodium pimelate. The sodium salt of an aliphatic carboxylic acid particularly preferably contains disodium adipate, and the particles of the sodium salt of an aliphatic carboxylic acid particularly preferably are particles of disodium adipate. In this case, corrosion of the metal surface of a mold or the like can be more effectively suppressed, the thermal stability of the composition during heat molding can be further improved, and the heat resistance and impact resistance of the resulting molded body can be further improved.

[0090] The surface treatment material is a fatty acid or a salt thereof. Examples of the fatty acid or a salt thereof include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and behenic acid or salts thereof. The fatty acid or a salt thereof may be used alone or in combination of two or more.

[0091] The number of carbon atoms in the fatty acid or salt thereof is preferably 12 or more, more preferably 14 or more, even more preferably 18 or more, and preferably 24 or less, more preferably 22 or less, even more preferably 20 or less. When the number of carbon atoms in the fatty acid or salt thereof is equal to or more than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the obtained molded body are further improved.

[0092] From the viewpoint of further improving the dispersibility of the composite particles, further improving the thermal stability of the composition during heat molding, and further improving the heat resistance and impact resistance of the resulting molded body, it is preferable that the fatty acid or salt thereof contains stearic acid or a salt thereof, and it is more preferable that it contains stearic acid.

[0093] In order to satisfactorily treat the particle bodies with the surface treatment agent, the particle diameter of the composite particles is relatively small. In the particle size distribution of the composite particles on a volume basis, the particle diameter D50 is 3.0 μm or more and 30 μm or less. Since the particle diameter D50 of the composite particles is equal to or more than the lower limit and equal to or less than the upper limit, the dispersibility of the composite particles is improved, the thermal stability of the composition during heat molding is improved, and the heat resistance and impact resistance of the resulting molded body can be further improved.

[0094] The particle diameter D50 of the composite particles is preferably 3.2 μm or more, more preferably 3.5 μm or more, even more preferably 4.0 μm or more, and preferably 28 μm or less, more preferably 26 μm or less, even more preferably 24 μm or less, even more preferably 22 μm or less, even more preferably 20 μm or less, even more preferably 18 μm or less, particularly preferably 16 μm or less, and most preferably 15 μm or less. When the particle diameter D50 of the composite particles is above the lower limit and below the upper limit, the particle bodies are more easily coated with the surface treatment material, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the resulting molded body are further improved. In particular, when the particle diameter D50 of the composite particles is above the lower limit and below the upper limit, the impact resistance of the resulting molded body can be significantly improved. From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is particularly preferable that the particle diameter D50 of the composite particles is 26 μm or less.

[0095] The composite particles have a particle size D99 of 15 μm or more and 250 μm or less in the particle size distribution on a volume basis. Since the particle size D99 of the composite particles is equal to or more than the lower limit and equal to or less than the upper limit, the dispersibility of the composite particles is improved, the thermal stability of the composition during heat molding is improved, and the heat resistance and impact resistance of the obtained molded article can be further improved.

[0096] The particle diameter D99 of the composite particles is preferably 17 μm or more, more preferably 19 μm or more, even more preferably 21 μm or more, even more preferably 23 μm or more, even more preferably 25 μm or more, even more preferably 27 μm or more, particularly preferably 28 μm or more, and most preferably 30 μm or more, and is preferably 220 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, even more preferably 100 μm or less, even more preferably 80 μm or less, particularly preferably 70 μm or less, and most preferably 60 μm or less. When the particle diameter D99 of the composite particles is above the lower limit and below the upper limit, the particle bodies are easily coated with the surface treatment material, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the resulting molded body are further improved. In particular, when the particle diameter D99 of the composite particles is above the lower limit and below the upper limit, the dispersibility of the composite particles can be significantly improved. From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is particularly preferable that the particle diameter D99 of the composite particles is 150 μm or less.

[0097] The particle diameters D50 and D99 of the composite particles are average diameters measured on a volume basis, and are the 50% median diameter (D50) and 99% median diameter (D99) values. The particle diameters D50 and D99 of the composite particles can be measured by a laser diffraction / scattering method or the like. That is, the particle diameters D50 and D99 of the composite particles are the diameter values ​​corresponding to 50% and 99% of the particle size distribution, calculated from the smaller particle size side, in a volume-based particle size distribution, and are the particle diameters (D50 and D99) at which the cumulative distribution values ​​are 50% and 99%. A laser diffraction particle size distribution analyzer is preferably used as the measuring device. Commercially available laser diffraction particle size distribution analyzers include the "Microtrac MT3300EXII" manufactured by Microtrac-Bell. When using "Microtrac MT3300EXII" manufactured by Microtrac Bell, isopropanol (IPA) can be used as the dispersion medium.

[0098] The particles (particle bodies) of the sodium salt of the aliphatic carboxylic acid can be obtained, for example, by subjecting an aqueous solution containing the sodium salt of the aliphatic carboxylic acid to hot air drying or fluidized bed drying. The method for obtaining the particles of the sodium salt of the aliphatic carboxylic acid is not limited to the above-mentioned methods.

[0099] The composite particles can be obtained, for example, by mixing the sodium salt particles (particle bodies) of the aliphatic carboxylic acid with a surface treatment material. Specific examples include a heating and stirring method using a Henschel mixer. The method for obtaining the composite particles is not limited to the above-mentioned method.

[0100] The particle diameters D50 and D99 of the composite particles can be controlled, for example, by sorting the composite particles using a sieve. The particle diameters D50 and D99 of the composite particles can be controlled, for example, by sorting the particles (particle bodies) of the sodium salt of aliphatic carboxylic acid used in the composite particles using a sieve, and producing composite particles using the sorted particles of the sodium salt of aliphatic carboxylic acid. The particle diameters D50 and D99 of the particles of the sodium salt of aliphatic carboxylic acid can also be controlled by the following methods, etc.: A method of controlling the temperature of hot air when hot-air drying an aqueous solution containing the sodium salt of aliphatic carboxylic acid to obtain the particles (particle bodies) of the sodium salt of aliphatic carboxylic acid. A method of controlling the volume of hot air when hot-air drying an aqueous solution containing the sodium salt of aliphatic carboxylic acid to obtain the particles (particle bodies) of the sodium salt of aliphatic carboxylic acid.

[0101] The porosity of the particles (particle bodies) of the sodium salt of the aliphatic carboxylic acid is preferably at least 65, more preferably at least 67, even more preferably at least 70, and particularly preferably at least 72, and is preferably at most 90, more preferably at most 88, even more preferably at most 86, and particularly preferably at most 85. When the porosity of the particles of the sodium salt of the aliphatic carboxylic acid is at least the above lower limit and at most the above upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the obtained molded body are further improved.

[0102] The porosity of the particles of the sodium salt of the aliphatic carboxylic acid can be measured as follows.

[0103] ・Method: Mercury intrusion method ・Apparatus: Micromeritics Autopore V 9620 pore size distribution analyzer ・Procedure: After placing 0.10 g of sample in a 5 cc powder cell, the cell is evacuated and filled with mercury. The cell is then pressurized within a pressure range of 4 kPa to 1,200,000 kPa, and the amount of mercury intrusion into the pores of the sample is measured.

[0104] The porosity of the particles of the sodium salt of an aliphatic carboxylic acid can be controlled by the following methods, etc.: A method of controlling the temperature of hot air when drying an aqueous solution containing the sodium salt of an aliphatic carboxylic acid with hot air to obtain the particles of the sodium salt of an aliphatic carboxylic acid; A method of controlling the volume of hot air when drying an aqueous solution containing the sodium salt of an aliphatic carboxylic acid with hot air to obtain the particles of the sodium salt of an aliphatic carboxylic acid.

[0105] The aspect ratio of the composite particles is preferably 1.00 or more, more preferably 1.02 or more, even more preferably 1.04 or more, particularly preferably 1.06 or more, and is preferably 1.8 or less, more preferably 1.7 or less, even more preferably 1.6 or less, particularly preferably 1.5 or less. When the aspect ratio of the composite particles is equal to or more than the above lower limit and equal to or less than the above upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the obtained molded body are further improved.

[0106] The aspect ratio is the ratio of major axis to minor axis, and is determined by averaging the major axis / minor axis values ​​of a plurality of composite particles.

[0107] The aspect ratio of the composite particles can be controlled, for example, by selecting particles of the sodium salt of aliphatic carboxylic acid used in the composite particles and producing composite particles using the selected particles of the sodium salt of aliphatic carboxylic acid. The aspect ratio of the particles of the sodium salt of aliphatic carboxylic acid can be controlled by the following methods, etc.: A method of controlling the temperature of hot air when drying an aqueous solution containing the sodium salt of aliphatic carboxylic acid with hot air; A method of controlling the volume of hot air when drying an aqueous solution containing the sodium salt of aliphatic carboxylic acid with hot air to obtain the particles of the sodium salt of aliphatic carboxylic acid. The aspect ratio of the composite particles can also be controlled by the surface treatment state using a surface treatment material.

[0108] When the composite particles are added to water to obtain an aqueous dispersion containing 5% by weight of the composite particles, the pH of the aqueous dispersion is preferably 6.5 or higher, more preferably 6.6 or higher, even more preferably 6.7 or higher, even more preferably 6.8 or higher, particularly preferably 6.95 or higher, and most preferably 7.0 or higher, and is preferably 7.8 or lower, more preferably 7.7 or lower, even more preferably 7.6 or lower, and particularly preferably 7.4 or lower. When the pH of the aqueous dispersion is equal to or higher than the above lower limit and equal to or lower than the above upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the obtained molded body are further improved.

[0109] From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is preferable that the particle diameter D50 of the composite particles is 26 μm or less and the pH of the aqueous dispersion is 6.8 or more. From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is preferable that the particle diameter D99 of the composite particles is 150 μm or less and the pH of the aqueous dispersion is 6.8 or more.

[0110] From the viewpoint of further improving the heat resistance and impact resistance of the obtained molded body, particularly the impact resistance when a molded body having a complex shape is impacted, it is preferable that the particle diameter D50 of the composite particles is 22 μm or less and the pH of the aqueous dispersion is 6.95 or more. From the viewpoint of further improving the heat resistance and impact resistance of the obtained molded body, particularly the impact resistance when a molded body having a complex shape is impacted, it is preferable that the particle diameter D99 of the composite particles is 80 μm or less and the pH of the aqueous dispersion is 6.95 or more.

[0111] In the composite particles, the surface treatment material may be a particle or a layer. In addition, in the composite particles, the surface treatment material may be disposed on the entire surface of the particle body, or may be disposed on a portion of the surface of the particle body. In the composite particles, the surface treatment material may be disposed randomly on the surface of the particle body. In the composite particles, the thickness of the surface treatment material may be uniform or non-uniform.

[0112] The proportion of the surface area where the surface treatment material is disposed (coverage by the surface treatment material) relative to 100% of the surface area of ​​the particle body is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. When the proportion of the surface area where the surface treatment material is disposed (coverage by the surface treatment material) is equal to or greater than the lower limit, the dispersibility of the composite particles can be further improved, the thermal stability of the composition during heat molding can be further improved, and the heat resistance and impact resistance of the resulting molded body can be further improved. The proportion of the surface area where the surface treatment material is disposed relative to 100% of the surface area of ​​the particle body (coverage by the surface treatment material) can be 100% or less. The range of the proportion of the surface area where the surface treatment material is disposed relative to 100% of the surface area of ​​the particle body (coverage by the surface treatment material) can be set by appropriately selecting the lower limit and the upper limit.

[0113] In the vinyl chloride resin composition, the content of the surface treatment material derived from the composite particle and contained in the vinyl chloride resin composition (hereinafter, sometimes referred to as the content (1) of the surface treatment material) relative to 100 parts by weight of the particle bodies derived from the composite particle and contained in the vinyl chloride resin composition is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.3 parts by weight or more, even more preferably 0.4 parts by weight or more, still more preferably 0.6 parts by weight or more, particularly preferably 1.0 parts by weight or more, and most preferably 1.2 parts by weight or more, and is preferably 50 parts by weight or less, more preferably 10 parts by weight or less, even more preferably 6.0 parts by weight or less, even more preferably 5.0 parts by weight or less, still more preferably 4.0 parts by weight or less, still more preferably 3.0 parts by weight or less, still more preferably 2.8 parts by weight or less, particularly preferably 2.0 parts by weight or less, and most preferably 1.8 parts by weight or less. When the content (1) of the surface treatment material is equal to or greater than the lower limit and equal to or less than the upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the obtained molded body are further improved.

[0114] From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is preferable that the particle diameter D50 of the composite particles is 26 μm or less and the content (1) of the surface treatment material is 4.0 parts by weight or less. From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is preferable that the particle diameter D99 of the composite particles is 150 μm or less and the content (1) of the surface treatment material is 4.0 parts by weight or less.

[0115] From the viewpoint of further improving the heat resistance and impact resistance of the obtained molded body, particularly from the viewpoint of further improving the impact resistance when an impact is applied to a molded body having a complex shape, it is preferable that the particle diameter D50 of the composite particles is 22 μm or less and the content (1) of the surface treatment material is 2.8 parts by weight or less. From the viewpoint of further improving the heat resistance and impact resistance of the obtained molded body, particularly from the viewpoint of further improving the impact resistance when an impact is applied to a molded body having a complex shape, it is preferable that the particle diameter D99 of the composite particles is 80 μm or less and the content (1) of the surface treatment material is 2.8 parts by weight or less.

[0116] In the composite particles, the content of the surface treatment material (hereinafter sometimes referred to as the surface treatment material content (2)) relative to 100 parts by weight of the particle body is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.3 parts by weight or more, even more preferably 0.4 parts by weight or more, even more preferably 0.6 parts by weight or more, particularly preferably 1.0 parts by weight or more, and most preferably 1.2 parts by weight or more, and is preferably 50 parts by weight or less, more preferably 10 parts by weight or less, even more preferably 6.0 parts by weight or less, even more preferably 5.0 parts by weight or less, even more preferably 4.0 parts by weight or less, even more preferably 3.0 parts by weight or less, even more preferably 2.8 parts by weight or less, particularly preferably 2.0 parts by weight or less, and most preferably 1.8 parts by weight or less. When the content (2) of the surface treatment material is equal to or greater than the lower limit and equal to or less than the upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition using the composite particles during heat molding is further improved, and the heat resistance and impact resistance of the obtained molded body are further improved.

[0117] From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is preferable that the particle diameter D50 of the composite particles is 26 μm or less and the content (2) of the surface treatment material is 4.0 parts by weight or less. From the viewpoint of further improving the heat resistance and impact resistance of the resulting molded article, it is preferable that the particle diameter D99 of the composite particles is 150 μm or less and the content (2) of the surface treatment material is 4.0 parts by weight or less.

[0118] From the viewpoint of further improving the heat resistance and impact resistance of the obtained molded body, particularly from the viewpoint of further improving the impact resistance when an impact is applied to a molded body having a complex shape, it is preferable that the particle diameter D50 of the composite particles is 22 μm or less and the content (2) of the surface treatment material is 2.8 parts by weight or less. From the viewpoint of further improving the heat resistance and impact resistance of the obtained molded body, particularly from the viewpoint of further improving the impact resistance when an impact is applied to a molded body having a complex shape, it is preferable that the particle diameter D99 of the composite particles is 80 μm or less and the content (2) of the surface treatment material is 2.8 parts by weight or less.

[0119] The content of the composite particles in 100% by weight of the vinyl chloride resin composition is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, even more preferably 0.10% by weight or more, particularly preferably 0.12% by weight or more, and most preferably 0.15% by weight or more, and is preferably 3.0% by weight or less, more preferably 2.7% by weight or less, even more preferably 2.5% by weight or less, particularly preferably 2.0% by weight or less, and most preferably 1.8% by weight or less. When the content of the composite particles is above the above lower limit and below the above upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the resulting molded body are further improved. Furthermore, corrosion of metal surfaces such as molds is more effectively suppressed.

[0120] The content of the composite particles relative to 100 parts by weight of the vinyl chloride resin in the vinyl chloride resin composition is preferably 0.05 parts by weight or more, more preferably 0.10 parts by weight or more, even more preferably 0.12 parts by weight or more, particularly preferably 0.15 parts by weight or more, and is preferably 3.0 parts by weight or less, more preferably 2.7 parts by weight or less, even more preferably 2.5 parts by weight or less, particularly preferably 2.0 parts by weight or less, and most preferably 1.8 parts by weight or less. When the content of the composite particles is above the above lower limit and below the above upper limit, the dispersibility of the composite particles is further improved, the thermal stability of the composition during heat molding is further improved, and the heat resistance and impact resistance of the resulting molded body are further improved. Furthermore, corrosion of metal surfaces such as molds is more effectively suppressed.

[0121] The sodium content of the vinyl chloride resin composition (100% by weight) is preferably 0.08% by weight or more, more preferably 0.10% by weight or more, even more preferably 0.15% by weight or more, particularly preferably 0.20% by weight or more, and is preferably 0.50% by weight or less, more preferably 0.45% by weight or less, even more preferably 0.42% by weight or less, particularly preferably 0.40% by weight or less. When the sodium content is equal to or greater than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, corrosion of metal surfaces such as molds can be more effectively suppressed. The sodium content in the vinyl chloride resin composition can be measured using ICP emission spectrometry, ICP mass spectrometry, X-ray fluorescence spectrometry, or the like.

[0122] The vinyl chloride resin composition may contain a sodium-containing compound (hereinafter sometimes referred to as compound (A)) other than the particles of the sodium salt of the aliphatic carboxylic acid, or particles of the compound (A). In the vinyl chloride resin composition, the compound (A) or particles of the compound (A) may contain sodium.

[0123] Case (1) refers to the case where the sodium contained in the vinyl chloride resin composition is solely derived from the sodium salt of the aliphatic carboxylic acid. In case (1), the sodium content in 100% by weight of the vinyl chloride resin composition refers to the content of sodium derived from the sodium salt of the aliphatic carboxylic acid. Case (2) refers to the case where the sodium contained in the vinyl chloride resin composition is both derived from the sodium salt of the aliphatic carboxylic acid and derived from compound (A). In case (2), the sodium content in 100% by weight of the vinyl chloride resin composition refers to the sum of the content of sodium derived from the sodium salt of the aliphatic carboxylic acid and the content of sodium derived from compound (A).

[0124] <Inorganic Filler> The vinyl chloride resin composition does not contain an inorganic filler or contains an inorganic filler. The vinyl chloride resin composition may not contain an inorganic filler, or may contain an inorganic filler. The composite particles may be used in combination with an inorganic filler.

[0125] Examples of the inorganic filler include calcium carbonate, silica, talc, titanium oxide, zinc oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, clay, mica, wollastonite, zeolite, carbon black, graphite, glass beads, glass fibers, hydrocarbons, and metal fibers. From the viewpoints of improving the appearance of the vinyl chloride resin composition and the resulting molded article and increasing the mechanical strength of the resulting molded article, the inorganic filler is preferably calcium carbonate. Only one type of the inorganic filler may be used, or two or more types may be used in combination.

[0126] The inorganic filler is preferably inorganic particles, and the aspect ratio of the inorganic filler is preferably 1.0 or more and preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less.

[0127] The aspect ratio is the ratio of major axis to minor axis, and is determined by averaging the major axis / minor axis values ​​of a plurality of inorganic fillers.

[0128] When the vinyl chloride resin composition contains the inorganic filler, the content of the inorganic filler is preferably 2 wt% or more, more preferably 4 wt% or more, and preferably 30 wt% or less, more preferably 20 wt% or less, and even more preferably 15 wt% or less, based on 100 wt% of the vinyl chloride resin composition. When the content of the inorganic filler is equal to or greater than the lower limit, the mechanical strength of the resulting molded article can be increased. When the content of the inorganic filler is equal to or less than the upper limit, the appearance of the vinyl chloride resin composition and the resulting molded article can be improved. The content of the inorganic filler may be 0 wt% (unused). It is particularly preferred that the vinyl chloride resin composition does not contain an inorganic filler, or that the content of the inorganic filler is 15 wt% or less, based on 100 wt% of the vinyl chloride resin composition.

[0129] The content of the inorganic filler relative to 100 parts by weight of the vinyl chloride resin in the vinyl chloride resin composition is preferably 2 parts by weight or more, more preferably 4 parts by weight or more, and preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and even more preferably 15 parts by weight or less. When the content of the inorganic filler is equal to or greater than the lower limit, the mechanical strength of the resulting molded article can be increased. When the content of the inorganic filler is equal to or less than the upper limit, the appearance of the vinyl chloride resin composition and the resulting molded article can be improved. The content of the inorganic filler may be 0 parts by weight (unused).

[0130] In the particle size distribution of the inorganic filler on a volume basis, the particle size D50 is preferably 10 nm or more and preferably 3.0 μm or less. When the particle size D50 of the inorganic filler is equal to or greater than the lower limit, the handling property can be improved. When the particle size D50 of the inorganic filler is equal to or less than the upper limit, the moldability of the composition can be improved.

[0131] The particle size D50 of the inorganic filler is the average diameter measured on a volume basis, and is the median diameter (D50) value at 50%. The particle size D50 of the inorganic filler can be measured by laser diffraction / scattering or the like. The particle size D50 of the inorganic filler is the diameter value corresponding to 50% of the particle size distribution on a volume basis, calculated from the smaller particle size side, and is the particle size (D50) value at which the cumulative distribution value is 50%. A laser diffraction particle size distribution analyzer is preferably used as the measuring device. Commercially available laser diffraction particle size distribution analyzers include the "Microtrac MT3300EXII" manufactured by Microtrac-Bell. When using the "Microtrac MT3300EXII" manufactured by Microtrac-Bell, isopropanol (IPA) can be used as the dispersion medium.

[0132] <Other Components> The vinyl chloride resin composition may contain various additives as needed. Examples of the additives include thermal stabilization aids, lubricants, processing aids, impact modifiers, heat resistance improvers, antioxidants, UV absorbers, antistatic agents, light stabilizers, fillers other than inorganic fillers, pigments, flame retardants, and plasticizers. The composite particles may be used in combination with the additives. The additives may be used alone or in combination of two or more.

[0133] The heat stabilization aid is not particularly limited, and examples thereof include epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, zeolite, etc. The heat stabilization aid may be used alone or in combination of two or more.

[0134] Examples of the lubricant include internal lubricants and external lubricants. The internal lubricant is used to reduce the flow viscosity of the molten resin during molding and prevent frictional heat generation. The internal lubricant is not particularly limited, and examples thereof include butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. The external lubricant is used to improve the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and examples thereof include paraffin wax, polyolefin wax, ester wax, and montanic acid wax. The lubricant may be used alone or in combination of two or more.

[0135] The processing aid is not particularly limited, and examples thereof include acrylic processing aids. Examples of the acrylic processing aids include alkyl acrylate-alkyl methacrylate copolymers having a weight-average molecular weight of 100,000 to 2,000,000, and specific examples include n-butyl acrylate-methyl methacrylate copolymers and 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymers. The processing aids may be used alone or in combination of two or more.

[0136] The impact modifier is not particularly limited, and examples thereof include methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, acrylic rubber, etc. The impact modifier may be used alone or in combination of two or more.

[0137] The heat resistance improver is not particularly limited, and examples thereof include α-methylstyrene-based and N-phenylmaleimide-based resins, etc. The heat resistance improver may be used alone or in combination of two or more types.

[0138] The antioxidant is not particularly limited, and examples thereof include phenol-based antioxidants, etc. The antioxidants may be used alone or in combination of two or more.

[0139] The ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. The ultraviolet absorbers may be used alone or in combination of two or more.

[0140] The light stabilizer is not particularly limited, and examples thereof include hindered amine light stabilizers, etc. The light stabilizers may be used alone or in combination of two or more.

[0141] The pigment is not particularly limited, and examples thereof include organic pigments and inorganic pigments. Examples of the organic pigments include azo-based organic pigments, phthalocyanine-based organic pigments, threne-based organic pigments, and dye lake-based organic pigments. Examples of the inorganic pigments include oxide-based inorganic pigments, molybdenum chromate-based inorganic pigments, sulfide / selenide-based inorganic pigments, and ferrocyanide-based inorganic pigments. From the viewpoint of further improving transparency, it is preferable that the vinyl chloride resin composition does not contain any of the above pigments.

[0142] The plasticizer may be added to improve the processability of the composition during molding. Since the addition of a plasticizer may reduce the heat resistance of the molded product, it is preferable to add a small amount of plasticizer. The plasticizer is not particularly limited, and examples include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate. The plasticizer may be used alone or in combination of two or more.

[0143] (Vinyl chloride resin molded article) The vinyl chloride resin molded article is formed using the vinyl chloride resin composition. The vinyl chloride resin composition can be used to obtain the vinyl chloride resin molded article. The vinyl chloride resin molded article is obtained by molding the vinyl chloride resin composition. The vinyl chloride resin molded article is a molded article of the vinyl chloride resin composition.

[0144] The vinyl chloride resin molded article is not particularly limited, and examples thereof include pipes, plates, containers, etc. The vinyl chloride resin molded article is preferably in the form of a plate, and more preferably in the form of a flat plate. The plate-like shape includes a sheet shape and a film shape.

[0145] The molding method for the vinyl chloride resin composition is not particularly limited, and examples thereof include extrusion molding, injection molding, calendar molding, press molding, etc. From the viewpoint of more effectively suppressing corrosion of the metal surface of a mold or the like, the molding method for the vinyl chloride resin composition is preferably injection molding, which has a long residence time.

[0146] The vinyl chloride resin molded article is preferably an injection molded article.

[0147] The molding machine used for molding is not particularly limited, and examples thereof include a single-screw extruder, a twin-screw counter-rotating parallel extruder, a twin-screw counter-rotating conical extruder, a twin-screw co-rotating extruder, a plunger injection molding machine, a pre-plunger injection molding machine, and a screw injection molding machine, etc. When molding is performed using the above molding machines, the mold for molding, the resin temperature, etc. are not particularly limited.

[0148] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0149] The following materials were prepared: The pH of the aqueous dispersion below is the pH of an aqueous dispersion containing 5 wt % of particles or composite particles obtained by adding particles or composite particles to water.

[0150] (Vinyl chloride resin) Vinyl chloride resin ("HA-58K" manufactured by Tokuyama Sekisui Kogyo Co., Ltd., chlorine content 67.3% by weight, average degree of polymerization 1000)

[0151] (Organotin-based stabilizer) Dibutyltin mercapto-based stabilizer ("RT-403" manufactured by Reagens)

[0152] (Particles: only particles (particle bodies) of sodium salt of aliphatic carboxylic acid, types A and H to J) <Type A> only particles (particle bodies) of sodium salt of aliphatic carboxylic acid: disodium adipate, particle size D50: 9.9 μm, particle size D99: 481.7 μm, aspect ratio: 1.2, pH of aqueous dispersion: 8.0, no surface treatment material used

[0153] <Type H> Particles (particle bodies) of sodium salt of aliphatic carboxylic acid only: disodium adipate, particle size D50: 5.7 μm, particle size D99: 351.1 μm, aspect ratio: 2.0, pH of aqueous dispersion: 6.5, no surface treatment material used

[0154] <Type I> Particles of sodium salt of aliphatic carboxylic acid (particle body) only: disodium adipate, particle size D50: 7.8 μm, particle size D99: 153.0 μm, aspect ratio: 2.1, pH of aqueous dispersion: 6.2, no surface treatment material used

[0155] <Type J> Particles (particle bodies) of sodium salt of aliphatic carboxylic acid only: disodium adipate, particle size D50: 34.9 μm, particle size D99: 138.5 μm, aspect ratio: 1.2, pH of aqueous dispersion: 8.1, no surface treatment material used

[0156] (Composite particles: types B to G and K) <Type B> Particle body: disodium adipate Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 0.5 parts by weight, particle size D50: 26.5 μm, particle size D99: 161.3 μm, aspect ratio: 1.3, pH of aqueous dispersion: 7.3

[0157] <Type C> Particle body: disodium adipate, Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 1.0 part by weight, Particle size D50: 23.5 μm, Particle size D99: 87.6 μm, Aspect ratio: 1.2, pH of aqueous dispersion: 7.3

[0158] <Type D> Particle body: disodium adipate Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 1.5 parts by weight, particle size D50: 5.3 μm, particle size D99: 23.0 μm, aspect ratio: 1.3, pH of aqueous dispersion: 7.2

[0159] <Type E> Particle body: disodium adipate Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 2.0 parts by weight, particle size D50: 9.2 μm, particle size D99: 40.5 μm, aspect ratio: 1.3, pH of aqueous dispersion: 7.0

[0160] <Type F> Particle body: disodium adipate Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 3.0 parts by weight, particle size D50: 16.2 μm, particle size D99: 56.7 μm, aspect ratio: 1.2, pH of aqueous dispersion: 6.9

[0161] <Type G> Particle body: disodium adipate Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 5.0 parts by weight, particle size D50: 9.7 μm, particle size D99: 43.4 μm, aspect ratio: 1.3, pH of aqueous dispersion: 6.7

[0162] <Type K> Particle body: disodium adipate Surface treatment material: stearic acid Composite particles: Content of surface treatment material per 100 parts by weight of particle body: 3.0 parts by weight, particle size D50: 1.4 μm, particle size D99: 13.4 μm, aspect ratio: 1.4, pH of aqueous dispersion: 6.6

[0163] (Lubricant) Polymer composite ester wax ("LOXIOL VPN301" manufactured by Emery Oleochemicals)

[0164] (Impact modifier) ​​MBS (Kaneka Corporation "Kane Ace M-511")

[0165] The composite particles of types B to G and K were prepared as follows.

[0166] The particles (particle bodies) and the surface treatment material were added to a Henschel mixer (manufactured by Kawada Kogyo Co., Ltd.) and mixed for 10 minutes to obtain composite particles.

[0167] (Examples 1 to 6 and Comparative Examples 1 to 5) The types and amounts of ingredients were added to a Henschel mixer (manufactured by Kawada Kogyo Co., Ltd.) as shown in Tables 1 and 3 below, and mixed for 10 minutes to obtain vinyl chloride resin compositions.

[0168] (Evaluation) (1) Disintegrability (Dispersibility) of Particles or Composite Particles (collectively referred to as Particles X) A weight equivalent to 200 mL of Particles X was placed in a 300 mL beaker, and a 6.1 kg weight was placed directly on Particles X to prepare a test specimen. This test specimen was placed in an oven ("DRK632DC" manufactured by ADVANTEC) and allowed to stand at 50°C for one day. After one day had passed, the test specimen was removed and allowed to cool to room temperature (23°C), and then an aggregate of Particles X (hereinafter sometimes referred to as "aggregate") was removed. Weights were placed on the aggregate, and the weight of the weight required to disintegrate the aggregate was measured. The disintegrability of the aggregate of Particles X was evaluated according to the following criteria. The weight of the weight required to disintegrate the aggregate is also shown in the table.

[0169] If the weight of the weight required to break down the aggregates is 1.0 kg or more, the aggregates are likely to remain when the particles X are used, resulting in poor dispersibility of the particles X in the vinyl chloride resin composition.

[0170] <Criteria for evaluation of disintegrability of particle or composite particle agglomerates> ◯: Weight of the weight required to disintegrate the agglomerates is less than 1.0 kg. ×: Weight of the weight required to disintegrate the agglomerates is 1.0 kg or more.

[0171] (2) Thermal Stability of Vinyl Chloride Resin Composition The obtained vinyl chloride resin composition was kneaded under the following kneading conditions to obtain a sheet having a thickness of 1 mm.

[0172] [Mixing conditions] Roll: Mixing roll manufactured by Yasuda Seiki Seisakusho Co., Ltd. Roll temperature: 203°C Roll time: 3 minutes (after wrapping)

[0173] The obtained sheet was cut into 1.5 cm square pieces to obtain test specimens. The test specimens were placed in an oven ("DRK632DC" manufactured by ADVANTEC) and heated to 200°C. The test specimens were visually inspected at 10-minute intervals to determine whether they had turned brown, and the browning time (the time it took for the molded body to turn brown) was determined. For example, if the molded body had not turned brown after 40 minutes but had turned brown after 50 minutes, the browning time was 50 minutes. The thermal stability of the vinyl chloride resin composition was evaluated according to the following criteria. The browning time is also shown in the table.

[0174] <Criteria for determining thermal stability of vinyl chloride resin compositions> ◯: Time required for browning to occur is 60 minutes or more ×: Time required for browning to occur is 50 minutes or less

[0175] (3) Impact Resistance 1 of Polyvinyl Chloride Resin Molded Articles Evaluation of impact resistance 1 of polyvinyl chloride resin molded articles is an evaluation of the impact resistance (impact strength) of the molded article when an impact is applied in a direction perpendicular to the main surface of the molded article.

[0176] The obtained vinyl chloride resin composition was kneaded under the following kneading conditions to obtain a sheet having a thickness of 1 mm.

[0177] [Mixing conditions] Roll: Mixing roll manufactured by Yasuda Seiki Seisakusho Co., Ltd. Roll temperature: 203°C Roll time: 3 minutes (after wrapping)

[0178] A plurality of the obtained 1 mm thick sheets were stacked and pressed under the following pressing conditions to obtain a 3 mm thick pressed sheet.

[0179] [Pressing conditions] Pressing machine: Hydraulic press machine manufactured by Kodaira Manufacturing Co., Ltd. Temperature: 205°C Pressing time: 4 minutes Cooling time: 2 minutes

[0180] The obtained press sheet was cut to obtain a JIS K7110 No. 2 test piece (length 64 mm × thickness 12.7 mm) (vinyl chloride resin molded article). The Izod impact strength of this test piece was measured using an Izod impact tester ("IM-501" manufactured by Tester Sangyo Co., Ltd.). The impact resistance 1 of the vinyl chloride resin molded article was evaluated according to the following criteria. The measured values ​​of Izod impact strength are also shown in the table.

[0181] <Criteria for Impact Resistance 1 of Polyvinyl Chloride Resin Molded Article> 〇〇: Izod impact strength exceeds 140 J / m. 〇: Izod impact strength is greater than 130 J / m and 140 J / m or less. ×: Izod impact strength is 130 J / m or less.

[0182] Tables 2 and 4 also show the results of subdividing the criteria for "〇: Izod impact strength is greater than 130 J / m and not greater than 140 J / m" into "〇+: Izod impact strength is greater than 135 J / m and not greater than 140 J / m" and "〇-: Izod impact strength is greater than 130 J / m and not greater than 135 J / m."

[0183] (4) Impact Resistance 2 of Polyvinyl Chloride Resin Molded Articles Evaluation of impact resistance 2 of polyvinyl chloride resin molded articles is an evaluation of impact resistance (fracture suppression ability) when an impact is applied to a molded article having a complex shape.

[0184] The vinyl chloride resin composition thus obtained was used to injection-mold a cheese (see FIG. 3, vinyl chloride resin molded article) having a diameter of 25A by a conventional molding method.

[0185] The resulting cheese was allowed to stand at 0°C ± 3°C for 60 minutes, and then subjected to an impact resistance test based on JIS K 6743. The test device used was a "U-F IMPACT TESTER SEPT1972" manufactured by Ueshima Seisakusho Co., Ltd.

[0186] A drop test was performed in which one cheese was placed on a support and a cylindrical, flat-bottomed weight (1 kg) was dropped from a height of 100 cm. If the cheese broke in the 100 cm drop test, the weight was dropped on a new cheese from a height 10 cm lower. If the cheese did not break, the drop test was performed again from a height 10 cm higher. This series of tests was performed on 19 cheeses, and the 50% breaking height was measured. The impact resistance 2 of the molded vinyl chloride resin composition was evaluated according to the following criteria. The measured values ​​of the 50% breaking height of the cheeses are also shown in the table.

[0187] <Criteria for Impact Resistance 2 of Polyvinyl Chloride Resin Molded Articles> 〇〇: 50% breaking height of cheese exceeds 120 cm. 〇: 50% breaking height of cheese exceeds 100 cm and is 120 cm or less. ×: 50% breaking height of cheese is 100 cm or less.

[0188] Tables 2 and 4 also show the results of subdividing the criteria for "Good: The 50% breaking height of the cheese is more than 100 cm and not more than 120 cm" into "Good+: The 50% breaking height of the cheese is more than 110 cm and not more than 120 cm" and "Good-: The 50% breaking height of the cheese is more than 100 cm and not more than 110 cm."

[0189] Details of the particles or composite particles, the types and amounts of the components of the vinyl chloride resin composition, and the evaluation results are shown in Tables 1 to 4 below.

[0190]

[0191]

[0192]

[0193]

[0194] The results of "(3) Impact resistance 1 of vinyl chloride resin molded body" for Examples 2 to 5 were all "〇〇". The results of "(3) Impact resistance 1 of vinyl chloride resin molded body" for Examples 1 and 6 were all "◯", but the Izod impact strength of Example 6 was greater than the Izod impact strength of Example 1. The results of "(4) Impact resistance 2 of vinyl chloride resin molded body" for Examples 3 and 4 were all "○○". The results of "(4) Impact resistance 2 of vinyl chloride resin molded body" for Examples 1, 2, 5, and 6 were all "◯", but the 50% breaking height of the cheeses of Examples 5 and 6 was greater than the 50% breaking height of the cheeses of Examples 1 and 2. The 50% breaking height of the cheese of Example 2 was greater than the 50% breaking height of the cheese of Example 1. Therefore, the impact resistance of the vinyl chloride resin molded articles of Examples 2 to 6 was superior to that of the vinyl chloride resin molded article of Example 1, and the impact resistance of the vinyl chloride resin molded article of Example 2 was superior to that of the vinyl chloride resin molded article of Example 1.

[0195] The results of "(1) Disintegrability (dispersibility) of particles or composite particles" for Examples 1 to 6 were all "Good", but the weight of the weight required to disintegrate the aggregates of Examples 1, 2, and 4 to 6 was smaller than the weight of the weight required to disintegrate the aggregates of Example 3. Therefore, the dispersibility of the particles of Examples 1, 2, and 4 to 6 was superior to the dispersibility of the particles of Example 3.

[0196] 1, 10... Composite particle 2... Particle body 3A... Surface treatment material (particle) 3B... Surface treatment material (layer)

Claims

1. A vinyl chloride resin composition comprising a vinyl chloride resin, an organotin stabilizer, and composite particles, wherein the composite particles have a particle size distribution on a volume basis in which the particle size D50 is 3.0 μm or more and 30 μm or less and the particle size D99 is 15 μm or more and 250 μm or less, the composite particles comprising a particle body and a surface treatment material disposed on the surface of the particle body, the material of the particle body being a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material being a fatty acid or a salt thereof.

2. The vinyl chloride resin composition according to claim 1, wherein the content of said composite particles is 0.10 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of said vinyl chloride resin.

3. The vinyl chloride resin composition according to claim 1 or 2, wherein the sodium salt of an aliphatic carboxylic acid comprises disodium adipate.

4. The vinyl chloride resin composition according to any one of claims 1 to 3, wherein the content of the surface treatment material derived from the composite particles and contained in the vinyl chloride resin composition is 0.3 parts by weight or more and 6.0 parts by weight or less per 100 parts by weight of the particle bodies derived from the composite particles and contained in the vinyl chloride resin composition.

5. The vinyl chloride resin composition according to any one of claims 1 to 4, wherein the fatty acid or its salt comprises stearic acid or its salt.

6. The vinyl chloride resin composition according to any one of claims 1 to 5, wherein when the composite particles are added to water to obtain an aqueous dispersion containing 5% by weight of the composite particles, the pH of the aqueous dispersion is 6.5 or more and 7.8 or less.

7. The vinyl chloride resin composition according to any one of claims 1 to 6, wherein the content of the organotin stabilizer is 0.10 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

8. The vinyl chloride resin composition according to any one of claims 1 to 7, wherein the organotin stabilizer comprises a tin mercapto stabilizer.

9. The vinyl chloride resin composition according to any one of claims 1 to 8, wherein the aspect ratio of the composite particles is 1.00 or more and 1.7 or less.

10. A vinyl chloride resin composition according to any one of claims 1 to 9, wherein the particle diameter D50 of the composite particles is 3.0 μm or more and 20 μm or less, and the particle diameter D99 of the composite particles is 25 μm or more and 250 μm or less.

11. The vinyl chloride resin composition according to any one of claims 1 to 10, which is a vinyl chloride resin composition for injection molding.

12. A vinyl chloride resin molded article, which is a molded article of the vinyl chloride resin composition according to any one of claims 1 to 11.

13. Composite particles, wherein the particle size distribution on a volume basis of the composite particles has a particle size D50 of 3.0 μm or more and 30 μm or less, and a particle size D99 of 15 μm or more and 250 μm or less, the composite particles comprising a particle body and a surface treatment material disposed on the surface of the particle body, the material of the particle body being a sodium salt of an aliphatic carboxylic acid, and the material of the surface treatment material being a fatty acid or a salt thereof.

14. The composite particle according to claim 13, wherein the content of the surface treatment material in the composite particle is 0.3 parts by weight or more and 6.0 parts by weight or less per 100 parts by weight of the particle body.

15. The composite particles according to claim 13 or 14, which are used in combination with a vinyl chloride resin.

16. The composite particles according to any one of claims 13 to 15, which are used in combination with a vinyl chloride resin and an organotin stabilizer.

17. Composite particles according to any one of claims 13 to 16, wherein the particle diameter D50 of the composite particles is 3.0 μm or more and 20 μm or less, and the particle diameter D99 of the composite particles is 25 μm or more and 250 μm or less.

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