Vinyl chloride resin composition and vinyl chloride resin molded article

Abstract

To provide a vinyl chloride resin composition that can improve thermal stability during thermal molding, can prevent bubbles from occurring inside the resultant molding, and can improve the heat resistance of the resultant molding.SOLUTION: A vinyl chloride resin composition according to the present invention contains a vinyl chloride resin, an organic tin-based stabilizer, a metal salt of aliphatic carboxylic acid which is at least one selected from the group consisting of a sodium salt of an aliphatic carboxylic acid and a calcium salt of aliphatic carboxylic acid, and an antioxidative component which is at least one selected from the group consisting of a phenol-based antioxidant, an amine-based antioxidant, a phosphorous-based antioxidant and a sulfur-based antioxidant.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a vinyl chloride resin composition containing a vinyl chloride resin, and also to a vinyl chloride resin molded article using the vinyl chloride resin composition. [Background technology]

[0002] PVC 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 hot molding, which may result in a decrease in mechanical strength of the molded article obtained or discoloration of the molded article.

[0004] In order to improve the thermal stability of the vinyl chloride resin, a thermal stabilizer may be used together with the vinyl chloride resin. Known examples of the thermal stabilizer include a tin-based stabilizer, a calcium-zinc-based stabilizer, a barium-zinc-based stabilizer, and a barium-cadmium-based stabilizer.

[0005] Patent Document 1 listed below discloses a vinyl chloride resin composition containing a vinyl chloride copolymer and an organotin compound that is liquid at 23°C. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-165868 A Summary of the Invention [Problem to be solved by the invention]

[0007] In Patent Document 1, an organotin stabilizer having a hydrogen chloride scavenging function is used, which makes it possible to suppress decomposition of the vinyl chloride resin and to increase the thermal stability of the vinyl chloride resin composition to a certain extent.

[0008] However, further improvement in the thermal stability of vinyl chloride resin compositions is required. In addition, when a thick molded body is produced, it takes a long time to cool the inside of the molded body, so that the vinyl chloride resin is easily decomposed and hydrogen chloride is easily generated. Therefore, when a thick molded body is produced, the hydrogen chloride gas may not be sufficiently captured by the organotin stabilizer alone. As a result, the hydrogen chloride that has not been captured becomes the starting point, and the decomposition of the vinyl chloride resin further progresses inside the molded body, and the hydrogen chloride increases, which causes a problem that bubbles are easily generated inside the molded body.

[0009] Furthermore, since organotin stabilizers are often liquid substances, the heat resistance of vinyl chloride resin molded articles may decrease depending on the amount of organotin stabilizer added.

[0010] An object of the present invention is to provide a vinyl chloride resin composition which can enhance thermal stability during hot molding, suppress the generation of bubbles inside a molded article, and enhance the heat resistance of the resulting molded article. Another object of the present invention is to provide a vinyl chloride resin molded article using the vinyl chloride resin composition. [Means for solving the problem]

[0011] The present inventors have found that by using a metal salt of an aliphatic carboxylic acid to supplement the hydrogen chloride trapping function, it is possible to effectively trap hydrogen chloride that cannot be completely trapped by an organotin stabilizer. Specifically, the hydrogen chloride trapping function of at least one metal salt of an aliphatic carboxylic acid selected from the group consisting of sodium salts of aliphatic carboxylic acids and calcium salts of aliphatic carboxylic acids can suppress the generation of bubbles caused by hydrogen chloride.

[0012] The present inventors also found that the use of at least one antioxidant component selected from the group consisting of phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants can improve thermal stability in the early stages of molding, and as a result, it was found that the generation of hydrogen chloride due to decomposition of vinyl chloride resin, which is the starting point for the generation of bubbles inside the molded body, can be reduced, thereby solving the above-mentioned problems, leading to the completion of the present invention.

[0013] According to a broad aspect of the present invention, there is provided a vinyl chloride resin composition comprising a vinyl chloride resin, an organotin stabilizer, at least one metal salt of an aliphatic carboxylic acid selected from the group consisting of sodium salts of aliphatic carboxylic acids and calcium salts of aliphatic carboxylic acids, and at least one antioxidant component selected from the group consisting of phenolic antioxidants, amine antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants.

[0014] In a specific aspect of the vinyl chloride resin composition according to the present invention, the content of the organotin stabilizer is 0.1 parts by weight or more and 3.0 parts by weight or less, based on 100 parts by weight of the vinyl chloride resin.

[0015] In a specific aspect of the vinyl chloride resin composition according to the present invention, the content of the metal salt of the aliphatic carboxylic acid is 0.1 parts by weight or more and 3.0 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.

[0016] In a specific aspect of the vinyl chloride resin composition according to the present invention, the content of the antioxidant component is 0.1 parts by weight or more and 5.0 parts by weight or less, based on 100 parts by weight of the vinyl chloride resin.

[0017] In a specific aspect of the vinyl chloride resin composition according to the present invention, the organotin stabilizer includes a tin mercapto stabilizer.

[0018] In a specific aspect of the vinyl chloride resin composition according to the present invention, the metal salt of an aliphatic carboxylic acid includes a metal salt of adipic acid.

[0019] According to a broad aspect of the present invention, there is provided a vinyl chloride resin molded article which is a molded article of the vinyl chloride resin composition described above. Effect of the Invention

[0020] The vinyl chloride resin composition according to the present invention includes a vinyl chloride resin, an organotin stabilizer, a metal salt of an aliphatic carboxylic acid, and an antioxidant component. In the vinyl chloride resin composition according to the present invention, the metal salt of an aliphatic carboxylic acid is at least one selected from the group consisting of a sodium salt of an aliphatic carboxylic acid and a calcium salt of an aliphatic carboxylic acid. In the vinyl chloride resin composition according to the present invention, the antioxidant component is at least one selected from the group consisting of a phenol-based antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant. Since the vinyl chloride resin composition according to the present invention has the above-mentioned configuration, it is possible to improve the thermal stability during hot molding, to suppress the generation of bubbles inside the molded body, and to improve the heat resistance of the obtained molded body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention will be described in detail below.

[0022] (Vinyl chloride resin composition) The vinyl chloride resin composition according to the present invention includes a vinyl chloride resin, an organotin stabilizer, a metal salt of an aliphatic carboxylic acid, and an antioxidant component. In the vinyl chloride resin composition according to the present invention, the metal salt of an aliphatic carboxylic acid is at least one selected from the group consisting of a sodium salt of an aliphatic carboxylic acid and a calcium salt of an aliphatic carboxylic acid. In the vinyl chloride resin composition according to the present invention, the antioxidant component is at least one selected from the group consisting of a phenol-based antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant.

[0023] Since the vinyl chloride resin composition according to the present invention has the above-mentioned configuration, it is possible to improve the thermal stability during hot molding. As a result, it is possible to increase the mechanical strength of the molded body obtained and prevent discoloration of the molded body. Furthermore, since the vinyl chloride resin composition according to the present invention has the above-mentioned configuration, it is possible to suppress the generation of bubbles inside the molded body and to improve the heat resistance of the molded body obtained. In particular, even when a thick molded body is produced, it is possible to suppress the generation of bubbles inside the molded body and to improve the heat resistance of the molded body obtained.

[0024] Hereinafter, each component contained in the vinyl chloride resin composition will be described.

[0025] (Vinyl chloride resin) The vinyl chloride resin according to the present invention is a resin having chlorine atoms. The vinyl chloride resin may be a chlorinated vinyl chloride resin or a non-chlorinated vinyl chloride resin. The chlorinated vinyl chloride resin is a resin obtained by chlorinating a vinyl chloride resin. From the viewpoint of further improving heat resistance, the vinyl chloride resin is preferably a chlorinated vinyl chloride resin. The vinyl chloride resin may be used alone or in combination of two or more kinds.

[0026] 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.

[0027] Examples of vinyl monomers copolymerizable with the vinyl chloride monomer include vinyl esters such as vinyl acetate and vinyl propionate; vinyl ether compounds; 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 (meth)acrylate and ethyl (meth)acrylate; and imide compounds such as maleimide. The vinyl monomers may be used alone or in combination of two or more.

[0028] The polymerization method of the vinyl chloride monomer and the polymerization method of the vinyl chloride monomer and the vinyl monomer are not particularly limited.The polymerization method includes suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization, and precipitation polymerization.From the viewpoint of efficiently obtaining the vinyl chloride resin, the polymerization method is preferably suspension polymerization, emulsion polymerization, solution polymerization, or precipitation polymerization.

[0029] The chlorinated vinyl chloride resin is preferably obtained by polymerizing the vinyl chloride monomer or the chlorinated vinyl monomer and the vinyl monomer to obtain a vinyl chloride resin, and then chlorinating the obtained vinyl chloride resin.

[0030] The method of chlorinating the vinyl chloride resin is not particularly limited. The method of chlorinating the vinyl chloride resin includes a method of putting the vinyl chloride resin into an aqueous solvent to obtain a suspension, and then adding chlorine to react the vinyl chloride resin with chlorine. This chlorination reaction proceeds under heating conditions or light irradiation conditions.

[0031] From the viewpoint of further enhancing the thermal stability of the chlorinated vinyl chloride resin, the chlorination reaction is preferably carried out under heating conditions.

[0032] From the viewpoint of further increasing the efficiency of the chlorination reaction, the temperature during the heating is preferably 80°C or higher and preferably 140°C or lower.

[0033] 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 further improved, and the impact resistance and surface smoothness of the obtained molded article can be further improved.

[0034] 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, based on 100% by weight of the chlorinated vinyl chloride resin. When the chlorine content of the chlorinated 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 chlorinated vinyl chloride resin is equal to or less than the upper limit, the moldability can be further improved, and the impact resistance and surface smoothness of the obtained molded article can be further improved.

[0035] 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.

[0036] 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, and even more preferably 900 or less. When the degree of polymerization is equal to or more than the lower limit, the mechanical strength of the molded article can be further 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 moldability can be further improved.

[0037] The vinyl chloride resin contained in the vinyl chloride resin composition is preferably in the form of particles. The volume average particle diameter of the vinyl chloride resin particles is preferably 0.1 μm or more and preferably 500 μm or less. When the volume average particle diameter is equal to or more than the lower limit, the handling property can be further improved. When the volume average particle diameter is equal to or less than the upper limit, the moldability can be further improved.

[0038] The volume average particle diameter of the vinyl chloride resin is an average diameter measured on a volume basis, and is the value of the median diameter at 50% (D50). The volume average particle diameter can be measured by a laser diffraction / scattering method or the like.

[0039] (Organotin stabilizer) The vinyl chloride resin composition contains an organotin stabilizer. In the vinyl chloride resin composition according to the present invention, the organotin stabilizer is a compound that inhibits decomposition of the vinyl chloride resin and captures hydrogen chloride generated during decomposition of the vinyl chloride resin.

[0040] Examples of the organotin stabilizer include tin mercapto stabilizers, tin malate stabilizers, tin carboxylate stabilizers, and tin sulfide stabilizers. The organotin stabilizers may be used alone or in combination of two or more.

[0041] Examples of the tin mercapto stabilizer include monoalkyltin mercapto, dialkyltin mercapto, monoalkyltin mercapto polymer, dialkyltin mercapto polymer, monoalkyltin mercapto sulfide, and dialkyltin mercapto sulfide.

[0042] Examples of the tin maleate stabilizer include monoalkyltin maleates, dialkyltin maleates, monoalkyltin maleate polymers, and dialkyltin maleate polymers.

[0043] Examples of the tin carboxylate stabilizer include monoalkyltin carboxylates and dialkyltin carboxylates.

[0044] Examples of the tin sulfide stabilizer include monoalkyltin sulfides and dialkyltin sulfides.

[0045] The organotin stabilizer is preferably an organotin heat stabilizer, such as dioctyltin diuralate, dioctyltin malate, or dioctyltin mercaptide.

[0046] From the viewpoint of more effectively preventing initial coloration during heat molding and improving the thermal stability during heat molding, the above-mentioned organotin stabilizer preferably contains a tin mercapto stabilizer, more preferably contains a dialkyltin mercapto, and even more preferably contains dioctyltin mercapto.

[0047] In order to more effectively exert the effects of the present invention, the vinyl chloride resin composition preferably contains a tin sulfide stabilizer.

[0048] The content of the organotin stabilizer is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.5 parts by weight or more, particularly preferably 0.8 parts by weight or more, and most preferably 1.0 parts by weight or more, relative to 100 parts by weight of the vinyl chloride resin. The content of the organotin stabilizer is preferably 5.0 parts by weight or less, more preferably 3.0 parts by weight or less, even more preferably 2.5 parts by weight or less, particularly preferably 2.2 parts by weight or less, and most preferably 2.0 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. When the content of the organotin stabilizer is equal to or more than the lower limit, the thermal stability during hot molding can be more effectively improved, and the generation of bubbles in the molded body can be more effectively suppressed. When the content of the organotin stabilizer is equal to or less than the upper limit, the heat resistance of the obtained molded body can be more effectively improved.

[0049] (Metal salts of aliphatic carboxylic acids) The vinyl chloride resin composition contains at least one metal salt of an aliphatic carboxylic acid selected from the group consisting of sodium salts of an aliphatic carboxylic acid and calcium salts of an aliphatic carboxylic acid. The metal salts of the aliphatic carboxylic acid may be used alone or in combination of two or more. The carboxylic acid in the aliphatic carboxylic acid may be a monocarboxylic acid or a polycarboxylic acid. The polycarboxylic acid may be a dicarboxylic acid. The sodium salt of the aliphatic carboxylic acid may be disodium aliphatic carboxylic acid.

[0050] The metal salt of the aliphatic carboxylic acid captures hydrogen chloride generated during decomposition of the vinyl chloride resin, thereby making it possible to suppress the generation of bubbles caused by hydrogen chloride and to improve the thermal stability during hot molding.

[0051] Examples of the metal salt of the aliphatic carboxylic acid include a metal salt of adipic acid, a metal salt of sebacic acid, a metal salt of azelaic acid, a metal salt of suberic acid, and a metal salt of pimelic acid. Examples of the aliphatic carboxylic acid constituting the metal salt of the aliphatic carboxylic acid include adipic acid, sebacic acid, azelaic acid, suberic acid, and pimelic acid.

[0052] From the viewpoint of improving the thermal stability during heat molding, the number of carbon atoms in the metal salt of an aliphatic carboxylic acid is preferably 4 or more, more preferably 5 or more, even more preferably 6 or more, and preferably 16 or less, more preferably 12 or less, even more preferably 8 or less. From the viewpoint of improving the thermal stability during heat molding, the metal salt of an aliphatic carboxylic acid preferably has a chain hydrocarbon skeleton having a carbon number of 2 or more and 14 or less.

[0053] From the viewpoint of improving the dispersion of the metal salt of an aliphatic carboxylic acid and more effectively exerting the effects of the present invention, it is preferable that the number of COOX groups in the metal salt of an aliphatic carboxylic acid is 2 (X is a metal, and X may be shared between the two COOX groups) and the number of carbon atoms in the metal salt of an aliphatic carboxylic acid is 6 or more and 16 or less. The number of carbon atoms in the metal salt of an aliphatic carboxylic acid includes the number of carbon atoms in the COOX groups.

[0054] Examples of the metal salt of an aliphatic carboxylic acid having the above-mentioned preferred embodiment include a metal salt of adipic acid, a metal salt of sebacic acid, a metal salt of azelaic acid, a metal salt of suberic acid, and a metal salt of pimelic acid. The metal salt of the aliphatic carboxylic acid preferably contains at least one metal salt of an aliphatic carboxylic acid selected from the group consisting of a metal salt of adipic acid, a metal salt of sebacic acid, a metal salt of azelaic acid, a metal salt of suberic acid, and a metal salt of pimelic acid. By using these preferred metal salts of aliphatic carboxylic acids, it is possible to more effectively suppress the generation of bubbles inside the molded body due to the capture of hydrogen chloride, and to further improve the thermal stability during heat molding. From the viewpoint of more effectively suppressing the generation of bubbles inside the molded body due to the capture of hydrogen chloride and further improving the thermal stability during heat molding, it is particularly preferable that the metal salt of the aliphatic carboxylic acid contains a metal salt of adipic acid.

[0055] The content of the metal salt of the aliphatic carboxylic acid is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.3 parts by weight or more, particularly preferably 0.7 parts by weight or more, and most preferably 1.0 parts by weight or more, relative to 100 parts by weight of the vinyl chloride resin. The content of the metal salt of the aliphatic carboxylic acid is preferably 5.0 parts by weight or less, more preferably 3.0 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 1.5 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. When the content of the metal salt of the aliphatic carboxylic acid is the lower limit or more, the thermal stability during hot molding can be more effectively improved, and the generation of bubbles in the molded body can be more effectively suppressed. When the content of the metal salt of the aliphatic carboxylic acid is the upper limit or less, the thermal stability during hot molding can be more effectively improved.

[0056] (Antioxidant ingredient) The vinyl chloride resin composition contains at least one antioxidant component selected from the group consisting of phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. The antioxidant components may be used alone or in combination of two or more.

[0057] The antioxidant component improves the thermal stability of the vinyl chloride resin composition at an early stage of molding, thereby reducing the amount of hydrogen chloride generated by decomposition of the vinyl chloride resin and suppressing the generation of bubbles in the molded product.

[0058] The phenol-based antioxidant is an antioxidant having a phenol skeleton. The amine-based antioxidant is an antioxidant having an amino group. The phosphorus-based antioxidant is an antioxidant containing a phosphorus atom. The sulfur-based antioxidant is an antioxidant containing a sulfur atom.

[0059] The phenol-based antioxidants include 2,6-di-t-butyl-p-cresol (BHT), butyl hydroxyanisole (BHA), 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-butylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), 4,4'-butylidene-bis-(3-methyl-6-t-butylphenol), 1,1,3-trimethyl-2,2-diphenyl-2,3-diphenyl-2,4 ... tetrakis[methylene-3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate]methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-t-butylphenol)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and bis(3-t-butyl-4-hydroxy-5-methylbenzenepropanoic acid)ethylene bis(oxyethylene).

[0060] Examples of the amine-based antioxidant include octylated diphenylamine, phenyl-β-naphthylamine, N,N'-diphenyl-p-phenylenediamine, and phenothiazine.

[0061] Examples of the phosphorus-based antioxidants include tridecyl phosphite, tris(tridecyl)phosphite, triphenyl phosphite, trinonylphenyl phosphite, bis(tridecyl)pentaerythritol diphosphite, bis(decyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butyl-6-methylphenyl)ethyl ester phosphorous acid, tris(2,4-di-t-butylphenyl)phosphite, and 2,2'-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus.

[0062] Examples of the sulfur-based antioxidants include dioctadecyl 3,3'-thiodipropionate, bis[2-methyl-4-(3-n-laurylthiopropionyloxy)-5-t-butylphenyl]sulfide, dilaurylthiodipropionate, diisostearylthiodipropionate, and mercaptobenzthiazole.

[0063] The content of the antioxidant component is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.3 parts by weight or more, particularly preferably 0.7 parts by weight or more, and most preferably 1.0 parts by weight or more, relative to 100 parts by weight of the vinyl chloride resin. The content of the antioxidant component is preferably 5.0 parts by weight or less, more preferably 3.0 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 1.5 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. When the content of the antioxidant component is equal to or more than the lower limit and equal to or less than the upper limit, the generation of bubbles in the molded body can be more effectively suppressed. In particular, when the content of the antioxidant component is equal to or more than the lower limit, the generation of bubbles in the molded body can be significantly effectively suppressed.

[0064] (Other ingredients) The vinyl chloride resin composition may contain various additives as necessary. Examples of the additives include heat stabilizing aids, lubricants, processing aids, impact modifiers, heat resistance improvers, UV absorbers, antistatic agents, light stabilizers, fillers, pigments, and plasticizers. The additives may be used alone or in combination of two or more.

[0065] The heat stabilization assistant is not particularly limited, and examples thereof include epoxidized soybean oil, phosphoric acid ester, polyol, hydrotalcite, zeolite, etc. The heat stabilization assistant may be used alone or in combination of two or more kinds.

[0066] The lubricant includes an internal lubricant and an external lubricant. The internal lubricant is used to reduce the flow viscosity of the molten resin during molding and to 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 increase 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.

[0067] 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. 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.

[0068] 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 kinds.

[0069] 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 kinds.

[0070] The ultraviolet absorbing agent is not particularly limited, and examples thereof include salicylic acid ester ultraviolet absorbing agents, benzophenone ultraviolet absorbing agents, benzotriazole ultraviolet absorbing agents, and cyanoacrylate ultraviolet absorbing agents, etc. The ultraviolet absorbing agents may be used alone or in combination of two or more kinds.

[0071] 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 kinds.

[0072] The filler is not particularly limited, and examples thereof include calcium carbonate, talc, etc. The filler may be used alone or in combination of two or more kinds.

[0073] 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 increasing transparency, it is preferable that the vinyl chloride resin composition does not contain the above pigments.

[0074] The plasticizer may be added to improve the processability during molding. The addition of a plasticizer may reduce the heat resistance of the molded product, so it is preferable to add a small amount of plasticizer. The plasticizer is not particularly limited, and examples thereof 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.

[0075] The vinyl chloride resin composition may contain a stabilizer other than the organotin stabilizer. Examples of the stabilizer other than the organotin stabilizer include lead stabilizers, calcium-zinc stabilizers, barium-zinc stabilizers, and barium-cadmium stabilizers. Examples of the lead 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 and phosphite.

[0076] (Vinyl chloride resin molding) The vinyl chloride resin molded article is formed using the vinyl chloride resin composition. The vinyl chloride resin composition can be used alone 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.

[0077] The shape of 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 form includes a sheet form and a film form.

[0078] The method for molding the vinyl chloride resin composition is not particularly limited, and examples thereof include extrusion molding, injection molding, calendar molding, and press molding.

[0079] 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, and a twin screw co-rotating extruder, etc. When molding is performed using the above molding machine, the mold for molding and the resin temperature, etc. are not particularly limited.

[0080] In the vinyl chloride resin composition according to the present invention, the thermal stability during hot molding can be enhanced and the generation of bubbles inside the molded article can be suppressed. Therefore, it is preferable that the vinyl chloride resin molded article is a vinyl chloride injection molded article.

[0081] The present invention will be specifically described below by way of examples and comparative examples, but the present invention is not limited to the following examples.

[0082] The following materials were prepared:

[0083] (Vinyl chloride resin) Polyvinyl chloride resin (Tokuyama Sekisui Kogyo Co., Ltd. "TS-800E", chlorine content 56.8% by weight, polymerization degree 800)

[0084] (Organotin stabilizer) Dioctyltin mercapto stabilizer (Dioctyltin mercapto, Nitto Kasei Kogyo Co., Ltd. "TVS#8940")

[0085] (Metal salts of aliphatic carboxylic acids) Sodium salt of aliphatic carboxylic acid (disodium adipate, TCI) Calcium salts of aliphatic carboxylic acids (calcium adipate, Alfa Chemistry)

[0086] (Antioxidant ingredient) Phenolic antioxidant (BASF "IRGANOX1010") Amine antioxidant (BASF "IRGANOX5057") Phosphorus-based antioxidant (BASF "IRGAFOS168") Sulfur-based antioxidant (BASF "IRGANOX PS 802 FL")

[0087] (lubricant) Polyethylene wax ("Hiwax 220RKT" manufactured by Mitsui Petrochemical Industries, Ltd.)

[0088] (Examples 1 to 20 and Comparative Examples 1 to 10) The types and amounts of the ingredients were as shown in Tables 1 to 5 below, and each ingredient was added to a Henschel mixer (Kawada Kogyo Co., Ltd.) and mixed for 5 minutes to obtain a vinyl chloride resin composition. The obtained vinyl chloride resin composition was kneaded under the following conditions to obtain a sheet having a thickness of 1.0 mm.

[0089] [conditions] Roll: Yasuda Seiki Seisakusho mixing roll Roll temperature: 190℃ Roll time: 3 minutes (after wrapping)

[0090] (evaluation) (1) Thermal stability The obtained sheet was cut into a length of 30 mm and a width of 30 mm to obtain a test sample A. The test sample A was placed in a gear oven (manufactured by Espec Corporation) and heated so that the temperature inside the oven reached 200° C. After the start of heating, the test sample A was visually inspected at 10-minute intervals, and the time at which it was possible to confirm that the sample had started to turn black was recorded, and the thermal stability was evaluated according to the following criteria.

[0091] [Criteria for thermal stability] ○○: The time when blackening started was confirmed to have started 70 minutes or more after the start of heating. ○: The time when the blackening started was confirmed to have started was 50 or 60 minutes after the start of heating. ×: The time when blackening could be confirmed was 40 minutes or less after the start of heating.

[0092] (2) Air bubble suppression performance The obtained sheets were overlapped and pressed under the following conditions to obtain a pressed sample.

[0093] [conditions] Press: Kodaira Manufacturing Co., Ltd. heat press molding machine (press surface material: SUS304) Press temperature: 200℃ Pressing time: Preheating 3 minutes + Pressurizing 10 minutes Press pressure: 150kgf / cm 2 Press sample size: Thickness 10.0mm x Length 200mm x Width 200mm

[0094] The obtained press sample was cut into a length of 30 mm x width of 30 mm to obtain a test sample B (molded body). The test sample B (molded body) was placed in a gear oven (manufactured by Espec Corporation) and heated so that the temperature inside the oven reached 200°C. After 60 minutes, the test sample B (molded body) was cut vertically, and the bubbles in the test sample B (molded body) were confirmed, and the bubble suppression performance was evaluated according to the following criteria.

[0095] [Criteria for determining bubble suppression performance] ○○: No bubbles (no visible bubbles) ○: There are less than 10 tiny bubbles (less than 1 mm) and no bubbles larger than 1 mm. △: There are 10 to 15 tiny bubbles (less than 1 mm) and no bubbles larger than 1 mm. ×: 15 or more tiny bubbles (less than 1 mm) are present, or bubbles larger than 1 mm are present

[0096] (3) Heat resistance of molded products The obtained sheets were overlapped and pressed under the following conditions to obtain a pressed sample.

[0097] [conditions] Press: Toho Machinery Co., Ltd. heat press molding machine Press temperature: 200℃ Pressing time: Preheating 3 minutes + Pressurizing 2 minutes Press pressure: 150kgf / cm 2 Press sample size: Thickness 3.0mm x Length 200mm x Width 200mm

[0098] The obtained press sample was cut into a size of 30 mm in length x 30 mm in width to obtain a test sample C (molded body). The Vicat softening temperature of the test sample C (molded body) was measured in accordance with JIS K7206. The heat resistance of the test sample C (molded body) was evaluated according to the following criteria.

[0099] [Criteria for determining heat resistance of molded products] ○○: Vicat softening temperature is 76℃ or higher ○: Vicat softening temperature is 74℃ or higher and less than 76℃ ×: Vicat softening temperature is less than 74℃

[0100] The results are shown in Tables 1 to 5.

[0101] [Table 1]

[0102] [Table 2]

[0103] [Table 3]

[0104] [Table 4]

[0105] [Table 5]

Claims

1. A polyvinyl chloride resin, An organotin stabilizer; At least one metal salt of an aliphatic carboxylic acid selected from the group consisting of sodium salts of an aliphatic carboxylic acid and calcium salts of an aliphatic carboxylic acid; and at least one antioxidant component selected from the group consisting of a phenol-based antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant; The vinyl chloride resin composition, wherein the metal salt of an aliphatic carboxylic acid includes a metal salt of adipic acid.

2. 2. The vinyl chloride resin composition according to claim 1, wherein the content of the organotin stabilizer is 0.1 parts by weight or more and 3.0 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.

3. 3. The vinyl chloride resin composition according to claim 1, wherein the content of the metal salt of an aliphatic carboxylic acid is 0.1 parts by weight or more and 3.0 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.

4. 4. The vinyl chloride resin composition according to claim 1, wherein the content of the antioxidant component is 0.1 parts by weight or more and 5.0 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.

5. The vinyl chloride resin composition according to any one of claims 1 to 4, wherein the organotin stabilizer comprises a tin mercapto stabilizer.

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.

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