Vinyl chloride-based resin composition, vinyl chloride-based resin fabricated body, stabilizer composition for vinyl chloride-based resin, and method for producing vinyl chloride-based resin composition

Abstract

Provided is a vinyl chloride-based resin composition capable of enhancing thermal stability.　A vinyl chloride-based resin composition according to the present invention contains a vinyl chloride-based resin, an organotin-based stabilizer, and a sodium salt of an aliphatic carboxylic acid. The organotin-based stabilizer contains a tin mercapto-based stabilizer and a tin sulfide-based stabilizer. In 100 wt% of the total contained amount of the tin mercapto-based stabilizer and the tin sulfide-based stabilizer, the contained amount of the tin sulfide-based stabilizer is 5 to 30 wt% or less, and the weight ratio of the contained amount of the sodium salt of the aliphatic carboxylic acid to the total contained amount of the tin mercapto-based stabilizer and the tin sulfide-based stabilizer is 0.10 to 4.5.

Description

Vinyl chloride resin composition, vinyl chloride resin molded body, stabilizer composition for vinyl chloride resin, and method for producing vinyl chloride resin composition

[0001] The present invention relates to a vinyl chloride resin composition containing a vinyl chloride resin. The present invention also relates to a vinyl chloride resin molded article using the vinyl chloride resin composition. The present invention also relates to a stabilizer composition for vinyl chloride resin, use of the stabilizer composition in a vinyl chloride resin composition, and a method for producing a vinyl chloride resin composition.

[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, which may result in a decrease in the 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 the halogen-containing polymer. 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, the decomposition of the vinyl chloride resin is suppressed by an organotin compound, and the thermal stability of the vinyl chloride resin composition can be increased to a certain extent. In Patent Document 2, the thermal stability of the vinyl chloride resin composition can be increased to a certain extent by using a specific stabilizing composition.

[0009] However, when an organotin compound is used as in Patent Document 1, hydrogen chloride generated during heat molding cannot be sufficiently captured, resulting in a problem of insufficient thermal stability of the vinyl chloride 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 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 of a vinyl chloride resin composition (up to about 200°C), and the alkali metal salt of a fatty acid may continue to exist as a solid during processing of the vinyl chloride resin composition. If the alkali metal salt of a fatty acid continues to exist as a solid, it will be sparsely present in the resin and will not be able to sufficiently capture hydrogen chloride during processing, making it difficult to sufficiently enhance the thermal stability of the resulting molded article.

[0011] An object of the present invention is to provide a vinyl chloride resin composition capable of improving thermal stability. 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 a stabilizer composition for vinyl chloride resin capable of improving the thermal stability of a vinyl chloride resin composition, use of the stabilizer composition in a vinyl chloride resin composition, and a method for producing a vinyl chloride resin composition.

[0012] This specification discloses the following vinyl chloride resin composition, vinyl chloride resin molded article, stabilizer composition for vinyl chloride resin, use of the stabilizer composition in a vinyl chloride resin composition, and method for producing a vinyl chloride resin composition.

[0013] Item 1. A vinyl chloride resin composition comprising a vinyl chloride resin, an organotin stabilizer, and a sodium salt of an aliphatic carboxylic acid, wherein the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer, and the weight ratio of the content of the sodium salt of the aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less.

[0014] Item 2. The vinyl chloride resin composition according to Item 1, wherein the combined amount of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group is 5% by weight or more and 30% by weight or less, based on 100% by weight of the combined amount of the tin mercapto stabilizer and the tin sulfide stabilizer.

[0015] Item 3. The vinyl chloride resin composition according to Item 1 or 2, wherein the content of the sodium salt of the aliphatic carboxylic acid is 0.1 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 4. The vinyl chloride resin composition according to any one of Items 1 to 3, wherein the sodium salt of an aliphatic carboxylic acid is disodium adipate.

[0017] Item 5. The vinyl chloride resin composition according to any one of Items 1 to 4, wherein the amount of the organotin stabilizer is 0.1 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0018] Item 6. 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 5.

[0019] Item 7. A stabilizer composition for vinyl chloride resins, comprising an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid, wherein the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer, the weight ratio of the content of the sodium salt of the aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less, and the stabilizer composition is used by being added to a vinyl chloride resin.

[0020] Item 8. Use of a stabilizer composition containing an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid in a vinyl chloride resin composition, wherein the organotin stabilizer contains a tin mercapto stabilizer and a tin sulfide stabilizer, the content of the tin sulfide stabilizer in the stabilizer composition is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer, and the weight ratio of the content of the sodium salt of an aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer in the stabilizer composition is 0.10 or more and 4.5 or less.

[0021] Item 9. A method for producing a vinyl chloride resin composition, comprising the step of adding the stabilizer composition for vinyl chloride resins according to Item 7 to a vinyl chloride resin to obtain a vinyl chloride resin composition.

[0022] The vinyl chloride resin composition according to the present invention contains a vinyl chloride resin, an organotin stabilizer, and a sodium salt of an aliphatic carboxylic acid. In the vinyl chloride resin composition according to the present invention, the organotin stabilizer contains a tin mercapto stabilizer and a tin sulfide stabilizer. In the vinyl chloride resin composition according to the present invention, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer. In the vinyl chloride resin composition according to the present invention, the weight ratio of the content of the sodium salt of an aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less. The vinyl chloride resin composition according to the present invention has the above-mentioned configuration, thereby enabling enhanced thermal stability.

[0023] The stabilizer composition for vinyl chloride resins, use of the stabilizer composition in a vinyl chloride resin composition, and method for producing a vinyl chloride resin composition according to the present invention can provide a vinyl chloride resin composition having a specific composition. Therefore, the stabilizer composition for vinyl chloride resins, use of the stabilizer composition in a vinyl chloride resin composition, and method for producing a vinyl chloride resin composition according to the present invention can improve the thermal stability of the vinyl chloride resin composition.

[0024] The present invention will be described in detail below.

[0025] (Vinyl chloride resin composition, stabilizer composition for vinyl chloride resin, use of stabilizer composition in vinyl chloride resin composition, method for producing vinyl chloride resin composition, and vinyl chloride resin set product) The vinyl chloride resin composition according to the present invention comprises a vinyl chloride resin, an organotin stabilizer, and a sodium salt of an aliphatic carboxylic acid. In the vinyl chloride resin composition according to the present invention, the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer. In the vinyl chloride resin composition according to the present invention, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer. In the vinyl chloride resin composition according to the present invention, the weight ratio of the content of the sodium salt of an aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less.

[0026] In the vinyl chloride resin composition according to the present invention, the content of the sodium salt of the aliphatic carboxylic acid is the content (% by weight) of the sodium salt of the aliphatic carboxylic acid in 100% by weight of the vinyl chloride resin composition. In the vinyl chloride resin composition according to the present invention, the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is the total content (% by weight) of the tin mercapto stabilizer and the tin sulfide stabilizer in 100% by weight of the vinyl chloride resin composition.

[0027] Although vinyl chloride resin compositions using conventional organotin stabilizers can improve thermal stability to a certain extent, they have the problem of not being able to sufficiently improve thermal stability, especially during hot molding. Furthermore, hydrogen chloride can corrode metal surfaces such as molds, making long-term production difficult. Furthermore, depending on the amount of organotin stabilizer added, the heat resistance of the resulting molded product can be reduced.

[0028] 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 about 200°C), and the alkali metal salt of the fatty acid may remain solid during processing of the vinyl chloride resin composition. If the alkali metal salt of the fatty acid remains solid, it will be sparsely present in the resin, and will not be able to sufficiently capture hydrogen chloride during processing. As a result, it will be difficult to sufficiently improve the thermal stability of the resulting molded article when obtaining a vinyl chloride resin composition.

[0029] The vinyl chloride resin composition according to the present invention has a specific composition, which allows for enhanced thermal stability (particularly thermal stability during hot molding), thereby enhancing the mechanical strength of the resulting molded article and preventing discoloration of the vinyl chloride resin molded article.

[0030] Furthermore, the vinyl chloride resin composition according to the present invention can inhibit corrosion of metal surfaces. 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 molded article come into contact with metal, corrosion of the metal can be inhibited.

[0031] 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.

[0032] 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 a vinyl chloride resin injection 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.

[0033] The stabilizer composition for vinyl chloride resin according to the present invention (hereinafter sometimes referred to as "stabilizer composition") contains an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid.

[0023] The use of the stabilizer composition according to the present invention in a vinyl chloride resin composition (hereinafter sometimes referred to as "use") is the use of a stabilizer composition comprising an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid in a vinyl chloride resin composition. In the stabilizer composition and use according to the present invention, the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer. In the stabilizer composition and use according to the present invention, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer. In the stabilizer composition and use according to the present invention, the weight ratio of the content of the sodium salt of an aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less. The stabilizer composition according to the present invention is used by being added to a vinyl chloride resin. The vinyl chloride resin composition in the use according to the present invention comprises a vinyl chloride resin.

[0034] In the stabilizer composition and use according to the present invention, the content of the sodium salt of the aliphatic carboxylic acid is the content (% by weight) of the sodium salt of the aliphatic carboxylic acid in 100% by weight of the stabilizer composition. In the stabilizer composition and use according to the present invention, the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is the total content (% by weight) of the tin mercapto stabilizer and the tin sulfide stabilizer in 100% by weight of the stabilizer composition.

[0035] A vinyl chloride resin composition can be obtained by adding the stabilizer composition according to the present invention to a vinyl chloride resin (use of the stabilizer composition in a vinyl chloride resin composition). The vinyl chloride resin to which the stabilizer composition is added may be in the form of a mixture with other components.

[0036] The method for producing a vinyl chloride resin composition according to the present invention comprises the step of adding the stabilizer composition for vinyl chloride resin to a vinyl chloride resin to obtain a vinyl chloride resin composition.

[0037] In the method for producing a vinyl chloride resin composition according to the present invention, the stabilizer composition for vinyl chloride resin is added to the vinyl chloride resin, so that the organotin stabilizer and the sodium salt of the aliphatic carboxylic acid are pre-mixed. The organotin stabilizer and the sodium salt of the aliphatic carboxylic acid are added to the vinyl chloride resin in a mixed state. Furthermore, by subjecting the obtained vinyl chloride resin composition to a molding process, a vinyl chloride resin molded article can be obtained.

[0038] This specification also discloses a vinyl chloride resin set. The vinyl chloride resin set according to the present invention comprises a vinyl chloride resin and a stabilizer composition. The stabilizer composition in the vinyl chloride resin set according to the present invention comprises an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid. In the vinyl chloride resin set according to the present invention, the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer. In the stabilizer composition in the vinyl chloride resin set according to the present invention, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer. In the stabilizer composition in the vinyl chloride resin set according to the present invention, the weight ratio of the content of the sodium salt of an aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less. The vinyl chloride resin set according to the present invention is used to obtain a vinyl chloride resin composition by adding the stabilizer composition to the vinyl chloride resin.

[0039] In the vinyl chloride resin set product according to the present invention, the vinyl chloride resin may be contained in a first container, and the stabilizer composition may be contained in a second container. The vinyl chloride resin and the stabilizer composition are preferably contained in separate containers. In the vinyl chloride resin set product according to the present invention, the vinyl chloride resin and the stabilizer composition are preferably not in contact with each other. The vinyl chloride resin in the vinyl chloride resin set product according to the present invention may be in the form of a mixture mixed with other components. The vinyl chloride resin to which the stabilizer composition is added may be in the form of a mixture mixed with other components.

[0040] The stabilizer composition for vinyl chloride resins, the method for producing a vinyl chloride resin composition, and the vinyl chloride resin set according to the present invention can produce a vinyl chloride resin composition having a specific composition. Therefore, the stabilizer composition for vinyl chloride resins, the method for producing a vinyl chloride resin composition, and the vinyl chloride resin set according to the present invention can improve the thermal stability of the vinyl chloride resin composition. Furthermore, the stabilizer composition for vinyl chloride resins, the method for producing a vinyl chloride resin composition, and the vinyl chloride resin set according to the present invention can achieve the effects described above as the effects obtained by the vinyl chloride resin composition according to the present invention.

[0041] Hereinafter, the vinyl chloride resin composition, the stabilizer composition for vinyl chloride resins, use of the stabilizer composition in a vinyl chloride resin composition, a method for producing the vinyl chloride resin composition, and each component contained in or used in the vinyl chloride resin set will be described.

[0042] <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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] The chlorine content of the vinyl chloride resin is preferably 56.8% by weight or more, 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 can be improved, and the impact resistance and surface smoothness of the obtained molded article can be improved.

[0051] 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 resulting 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 can be improved, and the impact resistance and surface smoothness of the resulting molded article can be improved.

[0052] 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.

[0053] The 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 1200 or less. When the degree of polymerization is equal to or greater than the lower limit, the mechanical strength of the molded article can be increased. When the degree of polymerization is equal to or less than the upper limit, it is not necessary to raise the temperature during molding, and good moldability can be achieved.

[0054]

[0033] 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 lower limit, the adhesive strength and mechanical strength of the resulting molded article can be increased. When the content of the vinyl chloride resin is at most the upper limit, there is no need to raise the molding temperature, and moldability can be improved.

[0055] The vinyl chloride resin is preferably in the form of particles. 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 the lower limit or more, handleability can be improved. When the particle size D50 of the vinyl chloride resin particles is the upper limit or less, moldability can be improved.

[0056] The particle size D50 of the vinyl chloride resin particles is the average diameter measured on a volume basis, and is the value of the median diameter (D50) at 50%. The particle size D50 of the vinyl chloride resin particles can be measured by a laser diffraction / scattering method 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 smallest particle size. A laser diffraction particle size distribution analyzer is preferably used as the measuring device. Commercially available laser diffraction particle size distribution analyzers include the "HELOS-KR" manufactured by Nippon Laser Corporation. When using the "HELOS-KR" manufactured by Nippon Laser Corporation, measurements can be performed at a dispersion pressure of 3.0 bar.

[0057] <Organotin-Based Stabilizer> The vinyl chloride resin composition and the stabilizer composition contain an organotin-based stabilizer that inhibits decomposition of the vinyl chloride resin and captures hydrogen chloride generated during decomposition of the vinyl chloride resin.

[0058] Examples of the organotin stabilizer include a tin mercapto stabilizer, a tin malate stabilizer, a tin carboxylate stabilizer, and a tin sulfide stabilizer. The organotin stabilizer may be used alone or in combination of two or more.

[0059] Examples of the tin mercapto stabilizer include monoalkyltin mercapto, dialkyltin mercapto, monoalkyltin mercapto sulfide, dialkyltin mercapto sulfide, monoalkyltin mercapto polymer, and dialkyltin mercapto polymer.

[0060] Examples of the tin maleate stabilizer include monoalkyltin maleates, dialkyltin maleates, monoalkyltin maleate polymers, and dialkyltin maleate polymers.

[0061] Examples of the tin carboxylate stabilizer include monoalkyltin carboxylates and dialkyltin carboxylates.

[0062] Examples of the tin sulfide stabilizer include monoalkyltin sulfides and dialkyltin sulfides.

[0063] In the vinyl chloride resin composition and the stabilizer composition, the organotin stabilizer includes a tin mercapto stabilizer and a tin sulfide stabilizer.

[0064] The organotin stabilizer is preferably an organotin heat stabilizer, such as dioctyltin diuralate, dioctyltin malate, or dioctyltin mercaptide.

[0065] From the viewpoint of more effectively exerting the effects of the present invention, it is preferable that the tin mercapto stabilizer has an alkyl group. From the viewpoint of more effectively exerting the effects of the present invention, it is preferable that the tin mercapto stabilizer has one or two alkyl groups. The tin mercapto stabilizer may have one or two alkyl groups. The tin mercapto stabilizer may have one or two alkyl groups. The tin mercapto stabilizer optionally contains a tin mercapto stabilizer having one alkyl group. The tin mercapto stabilizer may or may not contain a tin mercapto stabilizer having one alkyl group. The tin mercapto stabilizer optionally contains a tin mercapto stabilizer having two alkyl groups. The tin mercapto stabilizer may or may not contain a tin mercapto stabilizer having two alkyl groups. The tin mercapto stabilizer may contain a tin mercapto stabilizer having one alkyl group and a tin mercapto stabilizer having two alkyl groups.

[0066] Examples of the tin mercapto stabilizer (mono-form) having one alkyl group include monoalkyltin mercapto and monoalkyltin mercapto polymer.

[0067] Examples of the tin mercapto stabilizer having two alkyl groups (di-form) include dialkyltin mercapto and dialkyltin mercapto polymer.

[0068] From the viewpoints of further increasing the thermal stability during hot molding, preventing initial discoloration of the resulting molded body, and increasing the heat resistance of the molded body, the tin mercapto stabilizer preferably contains a tin mercapto stabilizer having one of the alkyl groups described above, more preferably contains a monoalkyltin mercapto, and even more preferably contains a monomethyltin mercapto.

[0069] From the viewpoint of more effectively exerting the effects of the present invention, it is preferable that the tin sulfide-based stabilizer has an alkyl group. From the viewpoint of more effectively exerting the effects of the present invention, it is preferable that the tin sulfide-based stabilizer has one or two alkyl groups. The tin sulfide-based stabilizer may have one or two alkyl groups. The tin sulfide-based stabilizer may have one or two alkyl groups. The tin sulfide-based stabilizer optionally contains a tin sulfide-based stabilizer having one alkyl group. The tin sulfide-based stabilizer may or may not contain a tin sulfide-based stabilizer having one alkyl group. The tin sulfide-based stabilizer optionally contains a tin sulfide-based stabilizer having two alkyl groups. The tin sulfide-based stabilizer may or may not contain a tin sulfide-based stabilizer having two alkyl groups. The tin sulfide-based stabilizer may contain a tin sulfide-based stabilizer having one alkyl group and a tin sulfide-based stabilizer having two alkyl groups.

[0070] Examples of the tin sulfide stabilizer (mono-form) having one alkyl group include monoalkyltin sulfides.

[0071] Examples of the tin sulfide stabilizer having two alkyl groups (di-form) include dialkyltin sulfide.

[0072] From the viewpoints of further enhancing the thermal stability during hot molding, preventing discoloration of the resulting molded body in the later stages, and enhancing the heat resistance of the molded body, the tin sulfide-based stabilizer preferably contains a monoalkyltin sulfide, and more preferably contains monobutyltin sulfide.

[0073] The content of the tin mercapto stabilizer having one alkyl group in 100% by weight of the total content of the tin mercapto stabilizer contained in the vinyl chloride resin composition and the stabilizer composition is defined as the mono-form content of the tin mercapto stabilizer. The mono-form content of the tin mercapto stabilizer is preferably 0% by weight or more, more preferably greater than 0% by weight, even more preferably 5% by weight or more, particularly preferably 10% by weight or more, and preferably 50% by weight or less, more preferably 45% by weight or less, and even more preferably 40% by weight or less. When the mono-form content of the tin mercapto stabilizer is equal to or greater than the above lower limit (exceeding the above lower limit) and equal to or less than the above upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded article can be further improved.

[0074] The content of the tin sulfide stabilizer having one alkyl group in 100% by weight of the tin sulfide stabilizer contained in the vinyl chloride resin composition and the stabilizer composition is defined as the mono-form content of the tin sulfide stabilizer. The mono-form content of the tin sulfide stabilizer is preferably 0% by weight or more, more preferably greater than 0% by weight, even more preferably 5% by weight or more, particularly preferably 10% by weight or more, and is preferably 100% by weight or less, more preferably 90% by weight or less, and even more preferably 80% by weight or less. When the mono-form content of the tin sulfide stabilizer is equal to or greater than the above lower limit (exceeding the above lower limit) and equal to or less than the above upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded article can be further improved.

[0075]

[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 0.05% by weight or more, even more preferably 0.1% by weight or more, particularly preferably 0.2% by weight or more, and most preferably 0.3% 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, still more preferably 3.0% by weight or less, particularly preferably 2.5% by weight or less, and most preferably 2.0% by weight or less. When the content of the organotin stabilizer is at least the lower limit and is at most the upper limit, thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded article can be further improved.

[0076]

[0033] The total content of the tin mercapto stabilizer and the tin sulfide stabilizer 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 0.1% by weight or more, particularly preferably 0.2% by weight or more, and most preferably 0.3% 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, still more preferably 3.0% by weight or less, particularly preferably 2.5% by weight or less, and most preferably 2.0% by weight or less. When the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is at least the above lower limit and is at most the above upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded article can be further improved.

[0077] In the vinyl chloride resin composition and the stabilizer composition, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer. In the vinyl chloride resin composition and the stabilizer composition, the content of the tin sulfide stabilizer is preferably 6% by weight or more, more preferably 8% by weight or more, even more preferably 10% by weight or more, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer, and is preferably 27% by weight or less, more preferably 25% by weight or less, even more preferably 22% by weight or less. When the content of the tin sulfide stabilizer is equal to or more than the above lower limit and equal to or less than the above upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the obtained molded body can be further improved.

[0078] In the vinyl chloride resin composition and the stabilizer composition, the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group (the mono-compound content in the total of the tin mercapto stabilizer and the tin sulfide stabilizer) is preferably 1% by weight or more, more preferably 3% by weight or more, even more preferably 5% by weight or more, and is preferably 40% by weight or less, more preferably 35% by weight or less, even more preferably 30% by weight or less, even more preferably 29% by weight or less, particularly preferably 27% by weight or less, and most preferably 25% by weight or less. When the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group is at least the above-mentioned lower limit and is at most the above-mentioned upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded product can be further improved.

[0079] In addition, when the above-mentioned organotin stabilizer contains a tin mercapto stabilizer having one alkyl group and does not contain a tin sulfide stabilizer having one alkyl group, the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group indicates the content of the tin mercapto stabilizer having one alkyl group. In addition, when the above-mentioned organotin stabilizer contains a tin sulfide stabilizer having one alkyl group and does not contain a tin mercapto stabilizer having one alkyl group, the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group indicates the content of the tin sulfide stabilizer having one alkyl group. Furthermore, when the above-mentioned organotin stabilizer contains both a tin mercapto stabilizer having one alkyl group and a tin sulfide stabilizer having one alkyl group, the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group refers to the total content of both stabilizers.

[0080] 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 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.2 parts by weight or more, and particularly preferably 0.3 parts by weight or more, and is preferably 5.0 parts by weight or less, more preferably 4.5 parts by weight or less, even more preferably 4.0 parts by weight or less, even more preferably 3.5 parts by weight or less, still more preferably 3.0 parts by weight or less, particularly preferably 2.4 parts by weight or less, and most preferably 1.8 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 during hot molding can be further improved, and the heat resistance of the obtained molded product can be further improved.

[0081] The total content of the tin mercapto stabilizer and the tin sulfide stabilizer relative to 100 parts by weight of the vinyl chloride resin in the vinyl chloride resin composition is preferably at least 0.05 parts by weight, more preferably at least 0.1 parts by weight, even more preferably at least 0.2 parts by weight, and particularly preferably at least 0.3 parts by weight, and is preferably at most 5.0 parts by weight, more preferably at most 4.5 parts by weight, even more preferably at most 4.0 parts by weight, even more preferably at most 3.5 parts by weight, even more preferably at most 3.0 parts by weight, particularly preferably at most 2.4 parts by weight, and most preferably at most 1.8 parts by weight. When the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is at least the above-mentioned lower limit and is at most the above-mentioned upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded product can be further improved.

[0082] The total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group, relative to 100 parts by weight of the vinyl chloride resin in the vinyl chloride resin composition, is preferably at least 0.05 parts by weight, more preferably at least 0.07 parts by weight, even more preferably at least 0.1 parts by weight, and particularly preferably at least 0.15 parts by weight, and is preferably at most 1.5 parts by weight, more preferably at most 1.3 parts by weight, even more preferably at most 1.2 parts by weight, particularly preferably at most 1.1 parts by weight, and most preferably at most 1.0 part by weight. When the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group is at least the above-mentioned lower limit and is at most the above-mentioned upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded product can be further improved.

[0083] The vinyl chloride resin composition and the stabilizer composition may contain an organotin stabilizer other than the tin mercapto stabilizer and the tin sulfide stabilizer. The vinyl chloride resin composition and the stabilizer composition may also contain a stabilizer other than the organotin stabilizer. Examples of stabilizers other than the organotin stabilizers include lead-based stabilizers, calcium-zinc-based stabilizers, barium-zinc-based stabilizers, and barium-cadmium-based stabilizers. Examples of 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.

[0084] <Sodium Salt of Aliphatic Carboxylic Acid> The vinyl chloride resin composition and the stabilizer composition contain a sodium salt of an aliphatic carboxylic acid. The sodium salt of an aliphatic carboxylic acid contains sodium. Specifically, the sodium salt of an aliphatic carboxylic acid contains at least one sodium atom. The aliphatic carboxylic acid in the sodium salt of an aliphatic carboxylic acid may be a monocarboxylic acid or a polycarboxylic acid. The polycarboxylic acid may be a dicarboxylic acid.

[0085] 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.

[0086] The vinyl chloride resin composition and the stabilizer composition contain a tin mercapto stabilizer, a tin sulfide stabilizer, and a sodium salt of an aliphatic carboxylic acid in combination, which allows for improved thermal stability (particularly thermal stability during thermoforming). Specifically, the vinyl chloride resin composition and the stabilizer composition containing these three components can effectively suppress discoloration during thermoforming (prolong the time until discoloration occurs) compared to compositions that do not contain at least one of a tin mercapto stabilizer, a tin sulfide stabilizer, and a sodium salt of an aliphatic carboxylic acid.

[0087] 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.

[0088] From the viewpoint of more effectively suppressing corrosion of the metal surface, 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.

[0089] From the viewpoint of further increasing the thermal stability during heat molding and further increasing the heat resistance of the resulting molded body, 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.

[0090] From the viewpoints of improving the dispersibility of the sodium salt of the aliphatic carboxylic acid, further increasing the thermal stability during heat molding, and further increasing the heat resistance of the resulting molded article, 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 6 or more and 16 or less. From the viewpoints of improving the dispersibility of the sodium salt of the aliphatic carboxylic acid, further increasing the thermal stability during heat molding, and further increasing the heat resistance of the resulting molded article, it is preferred that the sodium salt of the aliphatic carboxylic acid has a chain hydrocarbon skeleton having a carbon number of 2 or more and 14 or less.

[0091] 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, disodium pimelate, etc. From the viewpoints of more effectively suppressing corrosion of the metal surface, more effectively improving thermal stability during hot molding, and more effectively improving the heat resistance of the obtained molded body, it is particularly preferable that the sodium salt of an aliphatic carboxylic acid be disodium adipate.

[0092] The shape of the sodium salt of the aliphatic carboxylic acid is not particularly limited. The sodium salt of the aliphatic carboxylic acid may be spherical, may have a shape other than spherical, or may be flat. The sodium salt of the aliphatic carboxylic acid may be particulate.

[0093] The content of the sodium salt of the aliphatic carboxylic acid, based on 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 0.7% by weight or more, and most preferably 1.0% by weight or more, and is preferably 3.0% by weight or less, more preferably 2.0% by weight or less, even more preferably 1.8% by weight or less, particularly preferably 1.6% by weight or less, and most preferably 1.5% by weight or less. When the content of the sodium salt of the aliphatic carboxylic acid is equal to or greater than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the dispersibility of the sodium salt of the aliphatic carboxylic acid is improved, the thermal stability during hot molding is further improved, and the heat resistance of the resulting molded article is further improved. Furthermore, corrosion of the metal surface is more effectively suppressed.

[0094] In the vinyl chloride resin composition and the stabilizer composition, the weight ratio of the content of the sodium salt of the aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer (content of the sodium salt of the aliphatic carboxylic acid / total content of the tin mercapto stabilizer and the tin sulfide stabilizer) is 0.10 or more and 4.5 or less. This ratio (content of the sodium salt of the aliphatic carboxylic acid / total content of the tin mercapto stabilizer and the tin sulfide stabilizer) is preferably 0.20 or more, more preferably 0.30 or more, even more preferably 0.40 or more, and is preferably 4.3 or less, more preferably 4.0 or less, even more preferably 3.5 or less, and particularly preferably 3.0 or less. When this ratio (content of the sodium salt of the aliphatic carboxylic acid / total content of the tin mercapto stabilizer and the tin sulfide stabilizer) is above the lower limit and below the upper limit, the thermal stability during hot molding can be further improved, and the heat resistance of the resulting molded article can be further improved.

[0095] The content of the sodium salt of the aliphatic carboxylic acid relative to 100 parts by weight of the vinyl chloride resin in the vinyl chloride resin composition is preferably 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, even more preferably 0.7 parts by weight or more, particularly preferably 1.0 parts by weight or more, and is preferably 3.0 parts by weight or less, more preferably 2.8 parts by weight or less, even more preferably 2.5 parts by weight or less, particularly preferably 2.3 parts by weight or less, and most preferably 2.0 parts by weight or less. When the content of the sodium salt of the aliphatic carboxylic acid is equal to or greater than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the dispersibility of the sodium salt of the aliphatic carboxylic acid is improved, the thermal stability during hot molding is further improved, and the heat resistance of the resulting molded article is further improved. Furthermore, corrosion of the metal surface is more effectively suppressed.

[0096] 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 0.40% by weight or less, particularly preferably 0.35% by weight or less. When the sodium content is equal to or greater than the above lower limit and equal to or less than the above upper limit, corrosion of the metal surface 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.

[0097] The vinyl chloride resin composition may contain a sodium-containing compound other than the sodium salt of the aliphatic carboxylic acid (hereinafter, this may be referred to as "compound (A)"). The vinyl chloride resin composition contains sodium derived from the sodium salt of the aliphatic carboxylic acid. The vinyl chloride resin composition may contain sodium derived from the compound (A).

[0098] 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).

[0099] <Inorganic Filler> The vinyl chloride resin composition and the stabilizer composition do not contain an inorganic filler or contain an inorganic filler. The vinyl chloride resin composition and the stabilizer composition optionally contain an inorganic filler. The vinyl chloride resin composition and the stabilizer composition may not contain an inorganic filler, or may contain an inorganic filler.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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).

[0105] 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 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 can be improved.

[0106] The particle size D50 of the inorganic filler is the average diameter measured on a volume basis, and is the value of the median diameter (D50) at 50%. The particle size D50 of the inorganic filler can be measured by a laser diffraction / scattering method 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 smallest particle size. A laser diffraction particle size distribution analyzer is preferably used as the measuring device. Commercially available laser diffraction particle size distribution analyzers include the "HELOS-KR" manufactured by Nippon Laser Corporation. When using the "HELOS-KR" manufactured by Nippon Laser Corporation, measurements can be performed at a dispersion pressure of 3.0 bar.

[0107] <Other Components> The vinyl chloride resin composition and the stabilizer composition may contain various additives as needed. Examples of the additives include heat 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 additives may be used alone or in combination of two or more.

[0108] Examples of the heat stabilization aid 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.

[0109] 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. Examples of the internal lubricant 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. Examples of the external lubricant include paraffin wax, polyolefin wax, ester wax, and montanic acid wax. Only one type of the lubricant may be used, or two or more types may be used in combination.

[0110] Examples of the processing aid include acrylic processing aids. Examples of the acrylic processing aid 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. Only one type of the processing aid may be used, or two or more types may be used in combination.

[0111] Examples of the impact modifier 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.

[0112] Examples of the heat resistance improver 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.

[0113] The antioxidant may be a phenol-based antioxidant, etc. The antioxidant may be used alone or in combination of two or more kinds.

[0114] Examples of the ultraviolet absorber 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.

[0115] Examples of the light stabilizer include hindered amine light stabilizers, etc. The light stabilizers may be used alone or in combination of two or more.

[0116] Examples of the pigment include organic pigments and inorganic pigments. Examples of the organic pigment include azo-based organic pigments, phthalocyanine-based organic pigments, threne-based organic pigments, and dye lake-based organic pigments. Examples of the inorganic pigment 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.

[0117] The plasticizer may be added to improve processability during molding. Since the addition of a plasticizer may reduce the heat resistance of the molded body, it is preferable to add a small amount of plasticizer. Examples of the plasticizer include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate. Only one type of the plasticizer may be used, or two or more types may be used in combination.

[0118] (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.

[0119] Examples of the vinyl chloride resin molded article include pipes, plates, containers, etc. The vinyl chloride resin molded article is preferably in the form of a plate, and more preferably a flat plate. The plate form includes a sheet form and a film form.

[0120] Examples of methods for molding the vinyl chloride resin composition include extrusion molding, injection molding, calendar molding, press molding, etc. From the viewpoint of more effectively suppressing corrosion of the metal surface, the method for molding the vinyl chloride resin composition is preferably injection molding, which has a long residence time.

[0121] The vinyl chloride resin molded article is preferably an injection molded article.

[0122] Examples of molding machines used for molding include single-screw extruders, twin-screw counter-rotating parallel extruders, twin-screw counter-rotating conical extruders, twin-screw co-rotating extruders, plunger-type injection molding machines, pre-plunger-type injection molding machines, and screw-type injection molding machines. When molding is performed using the above molding machines, the mold used for molding, the resin temperature, etc. are not particularly limited.

[0123] 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.

[0124] The following materials were prepared:

[0125] (Vinyl chloride resin) Vinyl chloride resin ("TS-800E" manufactured by Tokuyama Sekisui Kogyo Co., Ltd., chlorine content 56.8% by weight, average degree of polymerization 800)

[0126] (Organotin-based stabilizers) Types of combinations of tin mercapto-based stabilizers and tin sulfide-based stabilizers: The following organotin-based stabilizers (organotin-based stabilizer compositions) of types 1 to 6, which are combinations of tin mercapto-based stabilizers and tin sulfide-based stabilizers, were prepared.

[0127] Type 1 (prepared product containing 80% by weight of the di-mercapto tin mercapto stabilizer (dioctyltin mercapto) and 20% by weight of the mono-mercapto tin sulfide stabilizer (monobutyltin sulfide) out of a total of 100% by weight of tin mercapto stabilizers and tin sulfide stabilizers)

[0128] Type 2 (prepared product containing 10% by weight of the total content of tin mercapto stabilizers and tin sulfide stabilizers (monooctyltin mercapto), 70% by weight of the di-mercapto stabilizer (dioctyltin mercapto), and 20% by weight of the mono-mercapto stabilizer (monobutyltin sulfide))

[0129] Type 3 (prepared product containing 80% by weight of the di-isomer of the tin mercapto stabilizer (dimethyltin mercapto) and 20% by weight of the di-isomer of the tin sulfide stabilizer (dimethyltin sulfide) out of a total of 100% by weight of tin mercapto stabilizers and tin sulfide stabilizers)

[0130] Type 4 (100% by weight of the total content of tin mercapto stabilizers and tin sulfide stabilizers, with the content of the dimer (dioctyltin mercapto) of the tin mercapto stabilizer being 100% by weight, manufactured by Nitto Kasei Kogyo Co., Ltd., "STANN ONZ-7F")

[0131] Type 5 (prepared product containing 20% ​​by weight of the mono-mercapto tin stabilizer (monomethyltin mercapto), 70% by weight of the di-mercapto tin stabilizer (dimethyltin mercapto), and 10% by weight of the mono-mercapto tin sulfide stabilizer (monobutyltin sulfide), out of a total of 100% by weight of tin mercapto stabilizers and tin sulfide stabilizers)

[0132] Type 6 (a preparation containing 50% by weight of the di-isomer of the tin mercapto stabilizer (dioctyltin mercapto), 25% by weight of the mono-isomer of the tin sulfide stabilizer (monobutyltin sulfide), and 25% by weight of the di-isomer of the tin sulfide stabilizer (dimethyltin sulfide), out of a total of 100% by weight of tin mercapto stabilizers and tin sulfide stabilizers)

[0133] (Sodium salt of aliphatic carboxylic acid) Disodium adipate ("BNT-7222" manufactured by Reagens)

[0134] (Lubricant) Polymer composite ester wax ("LOXIOL VPN301" manufactured by Emery Oleochemicals)

[0135] (Examples 1 to 8 and Comparative Examples 1 to 6) Of the ingredients shown in Tables 1 to 4 below, the ingredients other than the vinyl chloride resin and lubricant (i.e., the tin mercapto stabilizer, the tin sulfide stabilizer, and the sodium salt of an aliphatic carboxylic acid) were mixed for 5 minutes to obtain a stabilizer composition. This stabilizer composition, a vinyl chloride resin, and a lubricant were prepared. The vinyl chloride resin and the lubricant were added to a Henschel mixer (manufactured by Kawada Kogyo Co., Ltd.), and the obtained stabilizer composition was further added and mixed for 5 minutes to obtain a vinyl chloride resin composition containing the ingredients shown in Tables 1 to 4 below in the amounts shown in Tables 1 to 4 below.

[0136] In the table, "*1" indicates the content of the tin mercapto stabilizer and the tin sulfide stabilizer in a total content of 100% by weight. Also, in the table, "total content of the mono-form of the tin mercapto stabilizer and the mono-form of the tin sulfide stabilizer" indicates the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group in a total content of the tin mercapto stabilizer and the tin sulfide stabilizer, which is 100% by weight.

[0137] (Evaluation) (1) Thermal Stability (Discoloration Resistance) 300 g of the obtained vinyl chloride resin composition was kneaded under the following kneading conditions to obtain a sheet having a thickness of 1 mm.

[0138] [Mixing conditions] Roll: Mixing roll (manufactured by Yasuda Seiki Seisakusho) Roll temperature: 190°C Roll time: 3 minutes (after wrapping)

[0139] The obtained sheet was cut into a size of 1.5 cm × 1.5 cm to obtain test specimen A. Test specimen B was obtained in the same manner as test specimen A, except that in the preparation of the vinyl chloride resin composition, a resin composition for evaluation was used in which the sodium salt of an aliphatic carboxylic acid was replaced with the same amount of an organotin stabilizer (the content ratio of the tin mercapto stabilizer and the tin sulfide stabilizer conformed to the ratio in each example and comparative example).

[0140] The obtained specimens A and B were placed in an oven ("DRK632DC" manufactured by ADVANTEC) and heated at 200°C. Every 10 minutes, specimens A and B were removed, and the time (discoloration time) until each specimen turned brown was determined. For example, if the specimen had not turned brown after 40 minutes but had turned brown after 50 minutes, the discoloration time was 50 minutes. The difference in discoloration time was determined by subtracting the time until specimen B turned from the time until specimen A turned brown. Thermal stability (discoloration suppression ability) was evaluated according to the following criteria. The longer the difference in discoloration time, the more effectively specimen A can suppress discoloration during heat molding compared to specimen B. In Comparative Example 3, the time until specimen A turned brown was 10 minutes shorter than the time until specimen B turned brown, and in Comparative Example 4, the discoloration time during heat molding could not be effectively suppressed.

[0141] [Criteria for thermal stability (discoloration prevention)] ◯: Difference in discoloration time is 20 minutes or more △: Difference in discoloration time is 10 minutes or more but less than 20 minutes ×: Difference in discoloration time is less than 10 minutes (also applies when the difference in discoloration time is negative)

[0142] The compositions of the vinyl chloride resin compositions and the evaluation results are shown in Tables 1 to 4 below.

[0143]

[0144]

[0145]

[0146]

[0147] In the table, with regard to "*2", the difference in discoloration time between Example 7 and Comparative Example 2 was the same "10 minutes", but discoloration itself was suppressed more in Example 7 than in Comparative Example 2. Therefore, the vinyl chloride resin composition of Example 7 was superior in thermal stability to the vinyl chloride resin composition of Comparative Example 2.

Claims

1. A vinyl chloride resin composition comprising a vinyl chloride resin, an organotin stabilizer, and a sodium salt of an aliphatic carboxylic acid, wherein the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less out of a total content of the tin mercapto stabilizer and the tin sulfide stabilizer (100% by weight), and the weight ratio of the content of the sodium salt of the aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less.

2. The vinyl chloride resin composition according to claim 1, wherein the total content of the tin mercapto stabilizer having one alkyl group and the tin sulfide stabilizer having one alkyl group is 5% by weight or more and 30% by weight or less, based on 100% by weight of the total content of the tin mercapto stabilizer and the tin sulfide stabilizer.

3. A vinyl chloride resin composition according to claim 1 or 2, wherein the content of the sodium salt of the aliphatic carboxylic acid is 0.1 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

4. The vinyl chloride resin composition according to any one of claims 1 to 3, wherein the sodium salt of an aliphatic carboxylic acid is disodium adipate.

5. The vinyl chloride resin composition according to any one of claims 1 to 4, wherein the content of the organotin stabilizer is 0.1 parts by weight or more and 3.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

6. 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 5.

7. A stabilizer composition for vinyl chloride resins, comprising an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid, wherein the organotin stabilizer comprises a tin mercapto stabilizer and a tin sulfide stabilizer, the content of the tin sulfide stabilizer is 5% by weight or more and 30% by weight or less, based on a total content of the tin mercapto stabilizer and the tin sulfide stabilizer being 100% by weight, the weight ratio of the content of the sodium salt of the aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer is 0.10 or more and 4.5 or less, and the stabilizer composition is used by being added to vinyl chloride resins.

8. Use of a stabilizer composition containing an organotin stabilizer and a sodium salt of an aliphatic carboxylic acid in a vinyl chloride resin composition, wherein the organotin stabilizer contains a tin mercapto stabilizer and a tin sulfide stabilizer, and the content of the tin sulfide stabilizer in the stabilizer composition is 5% by weight or more and 30% by weight or less, based on a total content of the tin mercapto stabilizer and the tin sulfide stabilizer, of which 100% by weight is the total content of the tin mercapto stabilizer and the tin sulfide stabilizer, and the weight ratio of the content of the sodium salt of an aliphatic carboxylic acid to the total content of the tin mercapto stabilizer and the tin sulfide stabilizer in the stabilizer composition is 0.10 or more and 4.5 or less.

9. A method for producing a vinyl chloride resin composition, comprising the step of adding the stabilizer composition for vinyl chloride resins according to claim 7 to a vinyl chloride resin to obtain a vinyl chloride resin composition.

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