Vinyl chloride-based resin composition and molded article

Abstract

To provide a vinyl chloride-based resin composition capable of preventing bleed-out of a plasticizer under high temperature and ultraviolet irradiation, and having superior long-term light resistance and weather resistance, and also to provide a molded article obtained using the resin composition.SOLUTION: A vinyl chloride-based resin composition comprising a vinyl chloride polymer (A), an aliphatic epoxy compound (B), and a maleic anhydride copolymer (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a vinyl chloride resin composition and a molded article. [Background technology]

[0002] Vinyl chloride polymers have long been used as general-purpose resins due to their excellent mechanical properties and economical efficiency. In particular, so-called flexible vinyl chloride resin compositions containing plasticizers are used in a wide range of applications requiring flexibility, such as electrical wire coating materials, food packaging films, automotive interior and exterior components, construction materials such as tubing and packing, and industrial materials.

[0003] The plasticizers used in vinyl chloride resin compositions are compounds that are highly compatible with vinyl chloride polymers, but they can bleed out due to migration, weight, twisting, exposure to ultraviolet light, and other external environmental factors. This bleed-out can occur in two ways: when the plasticizer itself bleeds out, or when the plasticizer undergoes a chemical change and bleeds out.

[0004] Many commonly used plasticizers have ester bonds in their molecular structure, which increase their compatibility with vinyl chloride polymers. Ester bonds are known to hydrolyze in both acidic and basic environments, and the decomposed plasticizer becomes less compatible with polyvinyl chloride and is therefore discharged from the composition. This phenomenon of the plasticizer being discharged in liquid form is called "bleeding."

[0005] Plasticizer bleeding often occurs when a resin composition containing a vinyl chloride polymer is exposed to a humid environment for several days to several years after molding. When bleeding occurs, the amount of plasticizer in the resin composition decreases, resulting in a decrease in flexibility and the molded product's performance, which may not be as expected when designed. Furthermore, contamination of the surface of the molded product can also be a problem. Various methods have been studied to suppress bleeding in resin compositions containing a vinyl chloride polymer and a plasticizer, such as using plasticizers with specific structures.

[0006] Patent Document 1 describes a vinyl chloride resin composition in which an active hydrogen-containing compound such as succinic acid or oleic acid is added when the vinyl chloride resin and plasticizer are melt-kneaded. In this composition, the plasticizer is reacted with the active hydrogen-containing compound to suppress bleeding of the plasticizer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2013 / 084707 Summary of the Invention [Problem to be solved by the invention]

[0008] The technology described in Patent Document 1 is effective in suppressing plasticizer bleeding at room temperature, but its effectiveness in suppressing plasticizer bleeding at high temperatures and in ultraviolet light environments, which are anticipated for use in automobile interior and exterior components, has not been confirmed.

[0009] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a vinyl chloride resin composition that does not cause bleeding of a plasticizer even at high temperatures and in an ultraviolet environment and that has excellent long-term light resistance and weather resistance, and a molded article using the resin composition. [Means for solving the problem]

[0010] The present inventors have conducted extensive research in view of the above-mentioned problems and have found that by forming a resin composition containing a vinyl chloride polymer, an aliphatic epoxy compound, and a maleic anhydride copolymer, it is possible to obtain a resin composition that does not suffer from bleeding of the plasticizer even in an ultraviolet environment and that has excellent long-term light resistance and weather resistance.

[0011] That is, the gist of the present invention is as follows. A first aspect of the present invention is a vinyl chloride resin composition containing a vinyl chloride polymer (A), an aliphatic epoxy compound (B), and a maleic anhydride copolymer (C).

[0012] A second aspect of the present invention is the vinyl chloride resin composition of the first aspect, wherein the aliphatic epoxy compound (B) is an epoxidized vegetable oil.

[0013] A third aspect of the present invention is the vinyl chloride resin composition of the first or second aspect, wherein the aliphatic epoxy compound (B) has an oxirane oxygen concentration of 2% by mass or more and 13% by mass or less.

[0014] A fourth aspect of the present invention is the vinyl chloride resin composition according to any one of the first to third aspects, wherein the content of the aliphatic epoxy compound (B) is 10 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the vinyl chloride polymer (A).

[0015] A fifth aspect of the present invention is the vinyl chloride resin composition according to any one of the first to fourth aspects, wherein the acid value of the maleic anhydride copolymer (C) is 100 mgKOH / g or more and 700 mgKOH / g or less.

[0016] A sixth aspect of the present invention is the vinyl chloride resin composition according to any one of the first to fifth aspects, wherein the maleic anhydride copolymer (C) has a glass transition temperature of 40°C or higher and 200°C or lower.

[0017] A seventh aspect of the present invention is the vinyl chloride resin composition according to any one of the first to sixth aspects, wherein the maleic anhydride copolymer (C) contains at least a repeating unit derived from maleic anhydride and a repeating unit derived from styrene.

[0018] An eighth aspect of the present invention is the vinyl chloride resin composition according to any one of the first to seventh aspects, wherein the biomass ratio is 10% or more.

[0019] A ninth aspect of the present invention is a molded article obtained by molding the vinyl chloride resin composition according to any one of the first to eighth aspects.

[0020] A tenth aspect of the present invention is an automobile interior / exterior member comprising the molded article according to the ninth aspect.

[0021] An eleventh aspect of the present invention is a building material comprising the molded article according to the ninth aspect.

[0022] A twelfth aspect of the present invention is an industrial material including the molded article according to the ninth aspect.

[0023] A thirteenth aspect of the present invention is a method for producing a vinyl chloride resin composition, comprising a step of heating and kneading a vinyl chloride polymer (A), an aliphatic epoxy compound (B), and a maleic anhydride copolymer (C). [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a vinyl chloride resin composition that does not cause bleeding of a plasticizer even at high temperatures and has excellent long-term thermal stability, and a molded article made from the resin composition. Due to its excellent thermal stability and bleeding resistance, the resin composition of the present invention can be suitably used for automotive interior and exterior components, building materials, industrial materials, etc. DETAILED DESCRIPTION OF THE INVENTION

[0025] A resin composition (referred to as "the resin composition") as an example of an embodiment of the present invention will be described below, but the present invention is not limited to the following description and can be practiced with any modifications within the scope of the gist of the present invention. In this specification, when a numerical value or a physical property value is enclosed before and after "~", the values ​​before and after the "~" are used to include the values ​​before and after the "~"

[0026] The resin composition is a vinyl chloride-based resin composition containing a vinyl chloride polymer (A), an aliphatic epoxy compound (B), and a maleic anhydride copolymer (C). In this resin composition, the vinyl chloride polymer (A) is the base resin component, and the aliphatic epoxy compound (B) is a plasticizer. The inclusion of the aliphatic epoxy compound (B) is expected to improve the flexibility and thermal stability of the vinyl chloride polymer (A). Unlike conventional ester-based plasticizers, the aliphatic epoxy compound (B) has an epoxy structure that facilitates plasticization of the vinyl chloride polymer. However, there are concerns about bleeding of some of the aliphatic epoxy compound (B). Therefore, by including the maleic anhydride copolymer (C), some of the aliphatic epoxy compound (B) and the maleic anhydride copolymer (C) open their epoxy groups, which are prone to bleeding, and plasticize the vinyl chloride polymer. As a result, bleeding of some of the aliphatic epoxy compound (B), which is prone to bleeding, is suppressed. Therefore, this resin composition provides a vinyl chloride resin composition with excellent bleeding resistance.

[0027] <Vinyl chloride polymer (A)> In the present resin composition, the vinyl chloride polymer (A) is the base resin component. The vinyl chloride polymer (A) used in the present invention is not limited to any particular type, so long as it is a homopolymer of a vinyl chloride monomer or a copolymer of a vinyl chloride monomer and a monomer copolymerizable with the vinyl chloride monomer.

[0028] Examples of monomers copolymerizable with vinyl chloride monomer include vinyl esters such as vinyl acetate, vinyl propionate, and vinyl laurate; acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylic esters such as methyl methacrylate and ethyl methacrylate; maleic esters such as dibutyl maleate and diethyl maleate; fumaric esters such as dibutyl fumarate and diethyl fumarate; vinyl ethers such as vinyl methyl ether, vinyl butyl ether, and vinyl octyl ether; vinyl cyanides such as acrylonitrile and methacrylonitrile; α-olefins such as ethylene and propylene; vinylidene or vinyl halides other than vinyl chloride, such as vinylidene chloride and vinyl bromide; polyfunctional monomers such as diallyl phthalate and ethylene glycol dimethacrylate; and styrene. However, the monomers used are not limited to those mentioned above. These monomers may be used alone or in combination of two or more.

[0029] The method for producing the vinyl chloride polymer (A) is not particularly limited, and for example, a conventional method such as suspension polymerization, bulk polymerization, fine suspension polymerization, emulsion polymerization, or solution polymerization can be used.

[0030] In view of processability, moldability, and physical properties, the average degree of polymerization of the vinyl chloride polymer (A) is preferably in the range of 400 to 6,500, and more preferably in the range of 500 to 3,500, based on JIS K6721. If the average degree of polymerization is equal to or greater than the above lower limit, the physical properties of the resulting resin composition tend to be better, while if it is equal to or less than the above upper limit, the processability and moldability tend to be better.

[0031] Commercially available vinyl chloride polymers (A) can be used, including S1008 and S1007 (manufactured by Kaneka Corporation), TH1000 (manufactured by Taiyo Vinyl Chloride Co., Ltd.), TK-1700E, TK1300 (manufactured by Shin-Etsu Chemical Co., Ltd.), TK800 (manufactured by Shin-Etsu Chemical Co., Ltd.), and ZEST 800Y (manufactured by Shin-Dai-ichi Vinyl Chloride Co., Ltd.).

[0032] In the present invention, the vinyl chloride polymer (A) may be used alone or in the form of a mixture of two or more polyvinyl chlorides differing in copolymerization composition, type of copolymerizable monomer, average degree of polymerization, etc.

[0033] <Aliphatic epoxy compound (B)> In the present resin composition, the aliphatic epoxy compound (B) functions as a plasticizer for the vinyl chloride polymer (A). The aliphatic epoxy compound (B) used in the present invention refers to a non-aromatic hydrocarbon compound having an epoxy group. The carbon chain may be linear or branched, cyclic or acyclic, and the bond may be saturated or unsaturated. The number of functional groups may be monofunctional or multifunctional (two or more). Specific examples of aliphatic epoxy compounds include monoepoxy compounds such as monoglycidyl ether compounds of aliphatic alcohols and glycidyl esters of alkylcarboxylic acids, as well as multifunctional epoxy compounds such as polyglycidyl ether compounds of aliphatic polyhydric alcohols or their alkylene oxide adducts, and polyglycidyl esters of aliphatic long-chain polybasic acids. The carbon compounds contained in the aliphatic epoxy compound may be petroleum-derived or non-petroleum-derived, or may contain both.

[0034] Representative compounds of the aliphatic epoxy compound (B) include allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, C11-13 mixed alkyl glycidyl ether (a mixture of alkyl glycidyl ethers with 11 to 13 carbon atoms in the alkyl group), 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, sorbitol tetraglycidyl ether, and the like. Examples of suitable glycidyl ethers include glycidyl ethers of polyhydric alcohols such as diglycidyl ether, dipentaerythritol hexaglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and polyglycerin polyglycidyl ether; polyglycidyl ether compounds of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as propylene glycol, trimethylolpropane, and glycerin; and diglycidyl esters of aliphatic long-chain dibasic acids. Further examples include monoglycidyl ethers of aliphatic higher alcohols, glycidyl ester compounds of higher fatty acids, octyl epoxy stearate, butyl epoxy stearate, epoxidized polybutadiene, and epoxidized natural oils such as epoxidized vegetable oil.

[0035] Among these, it is preferable to use epoxidized vegetable oils, since they can impart flexibility and improved thermal stability to the vinyl chloride polymer (A) and a high biomass content without causing excessive bleeding.

[0036] Specific examples of epoxidized vegetable oils include epoxidized soybean oil, epoxidized linseed oil, epoxidized cottonseed oil, epoxidized peanut oil, epoxidized safflower oil, epoxidized grapeseed oil, epoxidized olive oil, etc., which can be used alone or in a mixture of two or more. Among these, epoxidized soybean oil and epoxidized linseed oil are preferred, with epoxidized soybean oil being particularly preferred, from the viewpoint of compatibility with the vinyl chloride polymer (A).

[0037] Epoxidized vegetable oils are essentially composed of monomers. However, commercially available epoxidized vegetable oils may contain trace amounts of dimers or higher due to various factors. Therefore, in the present invention, the epoxidized vegetable oil is essentially composed of monomers, but may contain trace amounts of polymers. However, the term "trace amount" as used herein means that the amount is typically 4% by mass or less, and preferably 2% by mass or less, of the total mass of the epoxidized vegetable oil.

[0038] Furthermore, the aliphatic epoxy compound (B) used in the present invention preferably has an oxirane oxygen concentration of 2% by mass or more, more preferably 6% by mass or more, and preferably 13% by mass or less, more preferably 10% by mass. If the oxirane oxygen concentration is equal to or higher than the lower limit, it is preferable because the thermal stability is good. On the other hand, if the oxirane oxygen concentration is equal to or lower than the upper limit, it is preferable because the colorability is good.

[0039] The oxirane oxygen concentration can be determined by reacting hydrogen bromide with an aliphatic epoxy compound and converting it into the amount of hydrogen bromide required to open the oxirane oxygen in the epoxy group. A specific measurement method is shown below. (1) Prepare a solution of toluene (500 g) and acetic acid (500 mL). (2) To the aliphatic epoxy compound (0.5 to 0.7 g), add the toluene-acetic acid mixed solution (10 mL) from (1) and stir. (3) Add 5 drops of crystal violet indicator and titrate with 0.10 mol / l hydrogen bromide-acetic acid standard solution while stirring with a magnetic stirrer. (4) The endpoint is when the indicator color remains blue-green for 30 seconds. However, near the endpoint, the drip rate should not exceed 1 drop per second. (5) Similarly, determine the titer of the 0.10 mol / l hydrogen bromide-acetic acid standard solution by carrying out steps (2) to (4) using a weighed amount of sodium carbonate. (6) Calculate the oxirane oxygen content using the following formula: Oxirane oxygen content (%) = (0.16 x A x F) / S A = Titration volume (mL) of 0.10 mol / L hydrogen bromide-acetic acid standard solution F = Factor of 0.10 mol / l hydrogen bromide-acetic acid standard solution S = sample amount (g) The factor (F) of the hydrogen bromide-acetic acid standard solution is calculated using the following formula: F=(188.7×W) / T W = weight of sodium carbonate (g) T = Titration volume (mL) of 0.10 mol / L hydrogen bromide-acetic acid standard solution

[0040] In the present resin composition, the content of the aliphatic epoxy compound (B) is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 50 parts by mass or more, per 100 parts by mass of the vinyl chloride polymer (A). On the other hand, it is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less. A content of the aliphatic epoxy compound (B) equal to or less than the above-mentioned upper limit is preferable because bleeding of the aliphatic epoxy compound (B) can be suppressed and the moldability and mechanical properties of the resulting resin composition can be maintained. Furthermore, a content equal to or greater than the above-mentioned lower limit can fully exhibit the effect of suppressing discoloration after a heat resistance test due to the improved thermal stability provided by the inclusion of the aliphatic epoxy compound (B), and can fully achieve the biomass content, which is important from the perspective of carbon neutrality.

[0041] <Maleic anhydride copolymer (C)> The maleic anhydride copolymer (C) used in the present invention is characterized by containing a repeating unit derived from maleic anhydride as a functional group reactive with the aliphatic epoxy compound (B). The maleic anhydride copolymer may be obtained by copolymerizing maleic anhydride with a vinyl compound. The maleic anhydride copolymer may contain a repeating unit derived from a source other than maleic anhydride, and the vinyl compound may be used alone or in combination of two or more types.

[0042] The glass transition temperature of the maleic anhydride copolymer (C) can be measured according to JIS K7121 (1987) and is preferably 200° C. or lower, more preferably 190° C. or lower, and even more preferably 180° C. or lower. It is also preferably 40° C. or higher, more preferably 50° C. or higher. If the temperature is equal to or higher than the lower limit, the physical properties of the resulting resin composition tend to be better, while if the temperature is equal to or lower than the upper limit, the processability and moldability tend to be better.

[0043] The repeating units derived from vinyl compounds contained in the maleic anhydride copolymer (C) are not particularly limited, but include repeating units derived from ethylene, propylene, vinyl acetate, acrylic aldehyde, acrylic acid, methyl acrylate, acrylonitrile, acrylamide, styrene, etc., and two or more of these may be used in combination. Among these, it is preferable to contain a repeating unit derived from styrene from the viewpoint of processability and moldability.

[0044] Unless otherwise specified, the acid value of the maleic anhydride copolymer (C) is a value calculated by neutralization titration, and is preferably from 100 mgKOH / g to 700 mgKOH / g, more preferably from 100 mgKOH / g to 550 mgKOH / g, even more preferably from 160 mgKOH / g to 500 mgKOH / g, and particularly preferably from 160 mgKOH / g to 450 mgKOH / g. These lower and upper limits of the acid value of the maleic anhydride copolymer can be combined arbitrarily. The acid value of the maleic anhydride copolymer (C) is preferably 700 mgKOH / g or less, more preferably 550 mgKOH / g or less, even more preferably 500 mgKOH / g or less, and particularly preferably 450 mgKOH / g or less, because the maleic anhydride copolymer (C) has excellent compatibility with the aliphatic epoxy compound (B). This also eliminates the need to use a vinyl compound with an extremely low molecular weight. On the other hand, a maleic anhydride copolymer having an acid value of preferably 100 mgKOH / g or more, more preferably 160 mgKOH / g or more, tends to have a sufficient proportion of acid anhydride groups per molecule and not an excessively high molecular weight. Therefore, a maleic anhydride copolymer having an acid value of 100 mgKOH / g or more is preferred because it reduces the resin viscosity of the resin composition of the present invention and provides excellent moldability.

[0045] The mass average molecular weight of the maleic anhydride copolymer is preferably in the range of from 1,000 to 100,000, more preferably from 5,000 to 50,000. If the mass average molecular weight of the maleic anhydride copolymer is equal to or greater than the lower limit, the physical properties of the resulting resin composition tend to be better, while if it is equal to or less than the upper limit, the processability and moldability tend to be better.

[0046] The mass average molecular weight of the maleic anhydride copolymer can be determined from the converted value measured by gel permeation chromatography (GPC) using standard polystyrene as a standard sample. If the product is commercially available, the catalog value can be used.

[0047] The maleic anhydride copolymer (C) in the resin composition can be a commercially available product, such as SMA Base Resin (styrene-maleic anhydride copolymer) SMA1000, SMA2000, SMA3000, and F30 manufactured by Sartomer, SMA Resin XIRAN (registered trademark) 9000, 6000, 4000, 2000P, 1440F, 1000, and EF80 manufactured by Polyscope, and Resify (styrene-methyl (meth)acrylate-maleic anhydride copolymer) R-100, R-200, and R-300 manufactured by Denki Kagaku Kogyo Co., Ltd.

[0048] The present resin composition may contain only one type of the maleic anhydride copolymer (C) or may contain two or more types that differ in monomer composition, weight average molecular weight, etc.

[0049] In the present resin composition, the content of the maleic anhydride copolymer (C) is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the vinyl chloride polymer, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less. A content of the maleic anhydride copolymer of not more than the above upper limit is preferred because the moldability and mechanical properties of the resulting resin composition can be maintained. A content of not less than the above lower limit is preferred because the inclusion of the maleic anhydride copolymer (C) can exhibit the effect of suppressing bleeding of the aliphatic epoxy compound (B).

[0050] <Other ingredients (D)> In addition to the vinyl chloride polymer (A), the aliphatic epoxy compound (B), and the maleic anhydride copolymer (C), the resin composition may contain other components such as various additives and thermoplastic resins, provided that the object of the present invention is not impaired.

[0051] For example, the vinyl chloride resin composition of the present invention may contain various well-known additives such as commonly known stabilizers, lubricants, processing aids, fillers, impact resistance modifiers, ultraviolet absorbers, colorants such as pigments or dyes, plasticizers, heat resistance improvers, foaming agents, antioxidants, antistatic agents, mildew inhibitors, antibacterial agents, flame retardants, flame retardant assistants, etc. These additives are used so as to obtain the effects of each additive within a range that does not impair the mechanical properties and moldability of the resulting molded article.

[0052] Specific examples of stabilizers include, but are not limited to, one or more of inorganic salts such as tribasic lead sulfate, lead silicate, and basic lead carbonate; metal soaps mainly composed of organic acid salts of metals such as lead, cadmium, barium, calcium, and zinc; those containing at least two of the aforementioned metals, such as fatty acid complexes or fatty acid (phosphites) of Ba-Zn, Ca-Zn, and Cd-Ba; carboxylate (phosphite)-based composite metal soaps or composite liquid metal soaps; and organotin compounds. When a stabilizer is incorporated into the vinyl chloride resin composition of the present invention, the amount of stabilizer incorporated is preferably 0.1 parts by mass or more, and particularly 1 part by mass or more, per 100 parts by mass of the vinyl chloride polymer (A), and is preferably 30 parts by mass or less, and particularly 15 parts by mass or less.

[0053] The flame retardant may be one or more of antimony trioxide, barium borate, zinc borate, zinc oxide, chlorinated polyethylene, other halogen-based flame retardants, etc. When a flame retardant is blended into the vinyl chloride resin composition of the present invention, the blending amount of the flame retardant is preferably 1 part by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of the vinyl chloride polymer, while being preferably 30 parts by mass or less, and more preferably 15 parts by mass or less.

[0054] Furthermore, a filler can be added to the vinyl chloride resin composition of the present invention. The addition of a filler not only ensures the rigidity of the resin component, but also contributes to capturing volatile components generated from the material and reducing the cost of the material itself. Examples of fillers include, but are not limited to, carbon black, calcium carbonate, titanium oxide, talc, aluminum hydroxide, magnesium hydroxide, hydrotalcite, clay, silica, and white carbon. These fillers may be used alone or in combination of two or more. Carbon black also functions as a black pigment. When a filler is added to the vinyl chloride resin composition of the present invention, the amount of filler added is preferably 1 part by mass or more, and more preferably 5 parts by mass or more, per 100 parts by mass of vinyl chloride polymer. On the other hand, it is preferably 100 parts by mass or less, and more preferably 50 parts by mass or less. If the amount of filler added is too small, the above-mentioned effects of addition tend to be insufficient, while if the amount is too large, mechanical properties and moldability tend to be impaired.

[0055] As the impact resistance reinforcement agent, one or more of known rubber polymers such as butadiene-based rubber polymers, silicone-based rubber polymers, and acrylic-based rubber polymers can be used.

[0056] As the plasticizer, any of the known plasticizers generally used in flexible vinyl chloride resin compositions can be used, for example, phthalate ester plasticizers such as di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate, diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), or phthalate esters of higher alcohols or mixed alcohols having about 10 to 13 carbon atoms; di-2-ethylhexyl adipate aliphatic dibasic acid ester plasticizers such as di-n-octyl adipate, di-n-decyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, and di-2-ethylhexyl sebacate; trimellitate ester plasticizers such as tri-2-ethylhexyl trimellitate (TOTM), tri-n-octyl trimellitate, tridecyl trimellitate, triisodecyl trimellitate, and di-n-octyl-n-decyl trimellitate; tributyl hydroxybenzoate; Examples of suitable plasticizers include phosphate ester-based plasticizers such as phosphate, tricresyl phosphate (TCP), triphenyl phosphate, trixylyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, tributoxyethyl phosphate, trichloroethyl phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(bromochloropropyl)phosphate, bis(2,3-dibromopropyl)-2,3-dichloropropyl phosphate, and bis(chloropropyl)monoctyl phosphate; biphenyl tetracarboxylic acid tetraalkyl ester-based plasticizers such as 2,3,3',4'-biphenyl tetracarboxylic acid tetraheptyl ester; polyester-based polymer plasticizers; epoxy-based plasticizers such as liquid epoxy resins; chlorinated paraffin; and chlorinated fatty acid esters such as pentachlorostearic acid alkyl ester. These plasticizers may be used alone or in combination of two or more. When the vinyl chloride resin composition of the present invention contains a plasticizer, it is preferably contained in an amount of 1 part by mass or more, and more preferably 200 parts by mass or less, per 100 parts by mass of the vinyl chloride polymer.When the content of the plasticizer is equal to or greater than the above lower limit, the softening effect due to the incorporation of the plasticizer can be sufficiently obtained, and when the content is equal to or less than the above lower limit, problems such as bleeding of the plasticizer can be prevented.

[0057] <Bulking ratio of resin composition> The content of vinyl chloride polymer (A) in the resin composition is preferably 20% by mass or more, more preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, the content of aliphatic epoxy compound (B) is preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 70% by mass or less, more preferably 50% by mass or less, the content of maleic anhydride copolymer (C) is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and the total content of vinyl chloride polymer (A), aliphatic epoxy compound (B), and maleic anhydride copolymer (C) in the resin composition of the present invention is preferably 30% by mass or more, more preferably 60% by mass or more, and even more preferably 90% by mass or more.

[0058] <Biomass content of resin composition> The biomass degree of the resin composition may be calculated from the biomass degrees of the components contained in the resin composition and the ratio of each component used during blending. Alternatively, the resulting resin composition may be directly analyzed using a 14C measurement method. When using the 14C measurement method, the biomass degree can be calculated from the 14C content obtained by a radiocarbon (14C) measurement method in accordance with ASTM-D6866. Because atmospheric carbon dioxide contains a certain amount of 14C, it is known that plants that grow by absorbing atmospheric carbon dioxide also contain a certain amount of 14C. On the other hand, it is also known that fossil fuels contain almost no 14C. Therefore, the biomass degree can be calculated by measuring the proportion of 14C contained in the total carbon atoms of the resin composition. The biomass degree of the resin composition of the present invention is preferably 10% or more, more preferably 20% or more, even more preferably 30% or more, and particularly preferably 40% or more. The upper limit is 100%. A low biomass degree tends to result in insufficient reduction of environmental impact.

[0059] <Method of manufacturing resin composition> The resin composition can be easily produced, for example, by blending a vinyl chloride polymer (A) as a base resin, an aliphatic epoxy compound (B), a maleic anhydride copolymer (C), and various additional components added as needed, and uniformly mixing or kneading the mixture while heating it to a temperature range in which the vinyl chloride polymer does not deteriorate, for example, a temperature of preferably 100°C or higher, more preferably 130°C or higher, and preferably 230°C or lower, more preferably 200°C or lower. While some of the components may be mixed in advance and then mixed with the other components, or all of the components may be mixed at once, mixing the materials containing the vinyl chloride polymer (A), the aliphatic epoxy compound (B), and the maleic anhydride copolymer (C) at once is preferred because it can better suppress bleeding of the plasticizer. That is, the method for producing the resin composition preferably includes a step of heating and kneading the vinyl chloride polymer (A), the aliphatic epoxy compound (B), and the maleic anhydride copolymer (C). By mixing the materials (A) to (C) at once, the oxirane oxygen in the aliphatic epoxy compound reacts with the maleic anhydride group in the maleic anhydride copolymer. This reaction modifies the aliphatic epoxy compound, increasing its molecular weight. This is thought to suppress molecular diffusion in the plasticizer resin (vinyl chloride resin), thereby suppressing bleeding. The mixer or kneader used for mixing or kneading the above-mentioned blending components is not particularly limited as long as it is a device that can mix and knead the blended components substantially uniformly.

[0060] As the kneader, for example, a device capable of kneading under shear force while heating, such as a single-screw extruder, twin-screw extruder, open roll, Banbury mixer, kneader, pressure kneader, or intensive mixer, is used. The composition can be produced by heat-kneading. Before heat-kneading, dry blending may be performed in advance using a mixer such as a tumbler, Henschel mixer, ribbon blender, planetary mixer, or universal mixer. After heat-kneading, the composition is removed from the kneader to obtain a composition. At this time, the composition may be formed into pellets using a pelletizer or the like.

[0061] <Molded body and method for molding resin composition> The molded article according to the present invention obtained by molding the present resin composition has excellent thermal stability and bleeding resistance, similar to the present resin composition. Examples of methods for molding the present resin composition include known methods such as press molding, injection molding, extrusion molding, blow molding, calendar molding, powder slush molding, and laminate molding using a 3D printer.

[0062] <Application> Because the resin composition has excellent thermal stability and bleed resistance, the resin composition and its molded articles can be suitably used in various industrial fields. For example, the resin composition can be used for automotive exterior materials such as window moldings, under-door moldings, and side moldings; automotive interior materials such as knobs and grips; building materials such as sealants, gaskets, and packings; industrial materials; electric wire coating materials; food packaging films; miscellaneous goods; and tubes. The resin composition can be particularly suitably used as automotive interior and exterior components, building materials, and industrial materials. [Example]

[0063] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. The values ​​of various production conditions and evaluation results in the following examples have the meaning of preferred upper or lower limit values ​​in the embodiments of the present invention, and preferred ranges may be ranges defined by the above-mentioned upper or lower limit values ​​and the values ​​in the following examples or by combining the values ​​of the examples.

[0064] <Raw materials used> The raw materials used in the examples and comparative examples are as follows.

[0065] [Table 1]

[0066] [Examples 1 to 3, Comparative Examples 1 to 5] The components were placed in a metal beaker in the proportions shown in Table 2 and hand-blended at room temperature, then kneaded for 10 minutes at a set temperature of 160°C and a rotation speed of 40 rpm using a Labo Plastomill Planetary Mixer manufactured by Toyo Seiki Seisakusho, Ltd. to obtain a resin composition. The mixture was then formed into a sheet approximately 1 mm or 2 mm thick and cooled to room temperature to obtain a soft vinyl chloride sheet.

[0067] <Evaluation method> (1) Compatibility The surface and cross section of the obtained soft vinyl chloride sheet having a thickness of 1.00±0.15 mm were visually observed and evaluated according to the following criteria. The results are shown in Table 2. A: Both the surface and cross section are uniform B: The surface is rough, or there are undissolved materials (also called fish eyes or lumps) on the cross section that originate from the raw materials. C: Uneven color is observed on the surface or cross section of the sheet.

[0068] (2) Bleeding resistance The resulting soft vinyl chloride sheet, 2.00±0.15 mm thick, was cut to an appropriate size and placed in a thermostatic chamber adjusted to 83±3°C using an ultraviolet fade meter manufactured by Suga Test Instruments Co., Ltd. The appearance was observed after 200 hours and 400 hours and evaluated according to the following criteria. The results are shown in Table 2. A: No bleeding or slight bleeding is observed. B: Bleeding is observed C: Significant bleeding and oil droplets present

[0069] (3) Thermal stability: Congo red test The resulting soft vinyl chloride sheet, 1.00 ± 0.15 mm thick, was cut with scissors to pieces no larger than 3 mm, and 2 ± 0.05 g of each was placed in a hard glass test tube measuring 15 mm in outer diameter and 150 mm in length (JIS R-3503 standard for glassware for chemical analysis). After dipping the Congo Red test paper in glycerin, the excess was wiped off between pieces of filter paper. The upper end of the test paper was held within 10 mm of the cotton pad, and the lower end was positioned 100 mm from the bottom of the test tube, as confirmed by a scale. The test tube was then inserted into an oil bath or tube-type aging tester maintained at 180 ± 3°C, and the time required for the tip of the test paper to change from a clear red to a clear blue was measured. The results are shown in Table 2.

[0070] (4) Biomass ratio The dry weight proportion of biomass contained in the resulting resin composition was calculated, and the results are shown in Table 2.

[0071] [Table 2]

[0072] <Evaluation results> As can be seen from Table 2, the resin compositions of Examples 1 to 3, which correspond to the vinyl chloride resin compositions of the present invention, contain component (A) vinyl chloride polymer, component (B) aliphatic epoxy compound, and component (C) maleic anhydride copolymer, and therefore have excellent bleeding resistance and thermal stability. The resin compositions of Comparative Examples 1 to 5 did not contain the maleic anhydride copolymer of component (C), and therefore were inferior in bleeding resistance and thermal stability. In Comparative Example 2, the acid value of the other acid component of component (X) was low, resulting in poor compatibility with the press sheet. Furthermore, the bleeding resistance was poor in Comparative Examples 3 and 4. The acid values ​​of the acid components were also evaluated, and it is presumed that this is because the molecular weight of the other acid components in component (X) was lower than that of the maleic anhydride copolymer in component (C), and the molecular weight of the modified component with the aliphatic epoxy compound in component (B) produced by kneading was not sufficiently large.

Claims

1. A vinyl chloride resin composition comprising a vinyl chloride polymer (A), an aliphatic epoxy compound (B), and a maleic anhydride copolymer (C).

2. 2. The vinyl chloride resin composition according to claim 1, wherein the aliphatic epoxy compound (B) comprises an epoxidized vegetable oil.

3. 2. The vinyl chloride resin composition according to claim 1, wherein the aliphatic epoxy compound (B) has an oxirane oxygen concentration of 2% by mass or more and 13% by mass or less.

4. 2. The vinyl chloride resin composition according to claim 1, wherein the content of the aliphatic epoxy compound (B) is 10 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the vinyl chloride polymer (A).

5. 2. The vinyl chloride resin composition according to claim 1, wherein the maleic anhydride copolymer (C) has an acid value of 100 mg KOH / g or more and 700 mg KOH / g or less.

6. 2. The vinyl chloride resin composition according to claim 1, wherein the maleic anhydride copolymer (C) has a glass transition temperature of 40°C or higher and 200°C or lower.

7. 2. The vinyl chloride resin composition according to claim 1, wherein the maleic anhydride copolymer (C) contains at least a repeating unit derived from maleic anhydride and a repeating unit derived from styrene.

8. 2. The vinyl chloride resin composition according to claim 1, having a biomass content of 10% or more.

9. A molded article obtained by molding the vinyl chloride resin composition according to any one of claims 1 to 8.

10. An interior or exterior automotive component comprising the molded article according to claim 9.

11. A building material comprising the molded article according to claim 9.

12. An industrial material comprising the molded article according to claim 9.

13. A method for producing a vinyl chloride resin composition, comprising the step of heat-kneading a vinyl chloride polymer (A), an aliphatic epoxy compound (B), and a maleic anhydride copolymer (C).

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