JP5636673B2 - Vinyl chloride resin composition for foam molding and foam molded article - Google Patents

Description

The present invention relates to a foam molding processing aid, a vinyl chloride resin composition for foam molding containing the processing aid, and a foam molded article obtained by molding the resin composition.
This application claims priority based on Japanese Patent Application No. 2008-305157 for which it applied to Japan on November 28, 2008, and uses the content here.

Vinyl chloride-based resins are widely used as general-purpose resin materials with high utility value because they have excellent properties such as chemical resistance, impact resistance, and weather resistance, and are inexpensive. Foam molding is one of the preferred applications, and for example, attempts are being made to produce foam molded articles as building materials oriented toward synthetic wood and the like.
However, in the case of producing a foamed molded product as it is from a vinyl chloride resin, under the normal molding temperature of the vinyl chloride resin, the elongation characteristics and the melt strength are insufficient, resulting in a heterogeneous foam cell structure, Arbitrary high expansion ratios cannot be achieved, and it is difficult to obtain satisfactory foamed molded articles. Further, since the allowable molding condition width of the vinyl chloride resin is narrow, it is difficult to obtain a satisfactory foamed molded article only by changing the molding processing conditions.
In addition, in conjunction with the popularization and expansion of vinyl chloride resin foam molding, in recent years, a more excellent molded appearance has been demanded for foam molded articles.
As a method for improving the foaming moldability of the vinyl chloride resin and the molding appearance of the foamed molded article, for example, Patent Document 1 discloses that 20 to 50% by mass of an alkyl methacrylate having 3 to 5 carbon atoms is included. There is disclosed a processing aid for foam molding comprising a copolymer obtained by copolymerizing a monomer component to be contained. Patent Document 2 discloses a vinyl chloride resin composition for foam molding containing polyisobutyl methacrylate having a number average molecular weight of 100,000 or less.

International Publication No. 1999/043741 Pamphlet JP-A-9-67498

  However, with the methods proposed in Patent Document 1 and Patent Document 2, the effect of improving the foaming moldability of the vinyl chloride resin and the molding appearance of the foamed molded product is not always sufficient.

  An object of the present invention is to provide a foam molding processing aid for obtaining a foam molded article having fine and uniform foam cells and having an excellent molded appearance.

That is, the present invention is a processing aid for foam molding comprising a polymer (A) obtained by polymerizing a monomer component (a) containing 65% by mass or more of isobutyl methacrylate, wherein the polymer (A ) Is a processing aid for foam molding in which 0.1 g is dissolved in 100 ml of chloroform and the reduced viscosity (η _sp / c) measured at 25 ° C. is 4 or more.
Moreover, this invention is a vinyl chloride-type resin composition for foam molding containing 1-25 mass parts of said processing aids for foam molding with respect to 100 mass parts of vinyl chloride-type resin.
Furthermore, the present invention is a foam molded product obtained by molding the vinyl chloride resin composition for foam molding.

    By blending the processing aid for foam molding of the present invention, the vinyl chloride resin composition can be efficiently melted and kneaded and the melt strength can be increased. Thereby, in the foam molding using the vinyl chloride resin composition, it is possible to obtain a foam molded article having fine and uniform foam cells and having an excellent molded appearance.

The processing aid for foam molding of the present invention contains a polymer (A) obtained by polymerizing a monomer component (a) containing isobutyl methacrylate.
The content of isobutyl methacrylate in the monomer component (a) (100% by mass) is 65% by mass or more, preferably 70% by mass or more, and more preferably 76% by mass or more. On the other hand, the content of isobutyl methacrylate in the monomer component (a) (100% by mass) is 100% by mass or less, preferably 99% by mass or less, more preferably 98% by mass or less. If the content of isobutyl methacrylate in the monomer component (a) is 65% by mass or more, the vinyl chloride resin composition for foam molding can be efficiently melted and kneaded, resulting in fine and uniform foaming. The cell structure and high foaming ratio can be easily achieved.
The monomer component (a) may contain other monomers as necessary.
Other monomers include, for example, methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl methacrylate, 2-ethylhexyl methacrylate; acrylic Acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, phenyl acrylate; styrene, α-methyl styrene, vinyl Examples thereof include aromatic vinyl monomers such as toluene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate; and acid anhydrides such as maleic anhydride. Other monomers may be used alone or in combination of two or more depending on the purpose.
The content of other monomers in the monomer component (a) (100% by mass) is 35% by mass or less, preferably 30% by mass or less, more preferably 24% by mass or less. On the other hand, the content of other monomers in the monomer component (a) (100% by mass) is 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more. These can be arbitrarily set as long as the vinyl chloride resin composition for foam molding is melted and kneaded, and further the molded appearance of the resulting foam molded article is not impaired. In addition, the volume ratio of the compound at the time of blending with the vinyl chloride resin is not reduced, the recoverability in the process of recovering the foaming processing aid as a powder is not impaired, and the powder blocking is not impaired. Can be set arbitrarily.
Moreover, you may contain polyfunctional monomers, such as divinylbenzene, allyl methacrylate, 1, 3- butanediol dimethacrylate, and triallyl cyanurate other than each above-mentioned monomer. The content of the polyfunctional monomer in the monomer component (a) (100% by mass) is preferably 0.01 to 2.0% by mass, more preferably 0.1 to 2.0% by mass. is there. By using 0.01% by mass or more of the polyfunctional monomer, the apparent molecular weight can be increased and the foam moldability can be improved. On the other hand, when the content is 2.0% by mass or less, the foaming ratio is not reduced and the molded appearance is not deteriorated.

In the present invention, the reduced viscosity (η _sp / c) of the polymer (A) constituting the processing aid for foam molding is 4 or more, preferably 5 or more. On the other hand, the reduced viscosity (η _sp / c) of the polymer (A) constituting the processing aid for foam molding is preferably 20 or less, more preferably 15 or less. By setting the reduced viscosity (η _sp / c) to 4 or more, the effect of imparting melt strength is enhanced, and it becomes easy to obtain a molded article having a sufficient expansion ratio. On the other hand, when the reduced viscosity (η _sp / c) is 20 or less, a foamed molded article having a good molded appearance can be easily obtained without imparting excessive melt strength.
This reduced viscosity (η _sp / c) is a value measured at 25 ° C. by dissolving 0.1 g of the polymer (A) in 100 ml of chloroform.
Examples of the method for adjusting the reduced viscosity (η _sp / c) of the polymer (A) within this range include methods such as adjustment of the amount of chain transfer agent and initiator used during polymerization and adjustment of the polymerization temperature. It is done. In order to obtain a foamed molded article having a good surface appearance, a method of adjusting using a chain transfer agent is preferred.

Various known methods can be used as the polymerization method for obtaining the polymer (A), and examples thereof include an emulsion polymerization method, a suspension polymerization method, and a solution polymerization method. The addition method of the monomer at the time of superposition | polymerization may be any of lump addition, dripping, and divided addition. The copolymer may be either a random copolymer or a block copolymer, but a random copolymer obtained by batch addition of monomers is preferred.
Examples of the emulsifier used in the emulsion polymerization method include anionic surfactants such as fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, alkyl phosphate esters, dialkyl sulfosuccinates; polyoxyethylene alkyl ethers, polyoxy Nonionic surfactants such as ethylene fatty acid esters, sorbitan acid fatty esters, and glycerin fatty acid esters; and cationic surfactants such as alkylamine salts. These emulsifiers may be used individually by 1 type, and may use 2 or more types together.
When the pH of the polymerization system is on the alkali side depending on the type of emulsifier, an appropriate pH adjusting agent can be used to prevent hydrolysis of the alkyl methacrylate. Examples of the pH regulator include boric acid-potassium chloride-potassium hydroxide, potassium dihydrogen phosphate-disodium hydrogen phosphate, boric acid-potassium chloride-potassium carbonate, citric acid-potassium hydrogen citrate, diphosphate phosphate. Examples thereof include potassium hydrogen-borax and disodium hydrogen phosphate-citric acid.

  In the polymerization, a polymerization initiator is usually used. Examples of the polymerization initiator include persulfates such as potassium persulfate; organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide; azobisisobutyronitrile, etc. A redox initiator comprising a combination of the persulfate and a reducing agent such as sodium formaldehyde sulfoxylate; a redox initiator comprising a combination of the organic peroxide and a reducing agent.

In the method for recovering the polymer (A) of the present invention, for example, when it is produced by an emulsion polymerization method, the obtained polymer (A) latex is cooled, and then an acid such as sulfuric acid, hydrochloric acid, phosphoric acid, Alternatively, the polymer (A) is precipitated by acid coagulation or salting out with an electrolyte such as a salt of aluminum chloride, calcium chloride, magnesium sulfate, aluminum sulfate, calcium acetate or the like, followed by further filtration, washing and drying. be able to. It can also be recovered by various methods such as spray drying and freeze drying.
In order to promote the formation of fine and uniform foam cells in the vinyl chloride resin composition for foam molding and to obtain a good molded appearance, it is preferable to use spray drying. Although there is no particular limitation on the spray drying conditions, it is preferable that the generated particles satisfy the following conditions, and spray drying can be performed under any conditions for generating such particles.
That is, among the powders formed by spray drying, it is preferable that the content of the powder in which the inside of the particles are fused and become homogeneous is less than 50% by mass, more preferably less than 25% by mass. It is. By making it less than 50% by mass, the homogeneous foamed cell structure and high foaming ratio, which are the object of the present invention, tend to be expanded, and the bulk ratio of the compound when blended with a vinyl chloride resin is further increased. Can be suppressed.

  The processing aid for foam molding of the present invention may contain additives as necessary in addition to the polymer (A) of the present invention. For example, powder flow properties such as aerosil and inorganic salts may be modified. And a quality agent.

  The vinyl chloride resin composition for foam molding of the present invention is formed by blending 1 to 25 parts by mass, preferably 5 to 15 parts by mass of a processing aid for foam molding with respect to 100 parts by mass of the vinyl chloride resin. is there. By making the blending ratio of the processing aid for foam molding to be 1 part by mass or more, the effect of imparting melt strength is enhanced, the foam has a high foaming ratio with fine and uniform foam cells, and has a good molding appearance. A molded body is easily obtained. Moreover, the fall of the shaping | molding external appearance of a foaming molding can be prevented by setting it as 25 mass parts or less.

The vinyl chloride resin of the present invention is not particularly limited. For example, a vinyl chloride homopolymer, a post-chlorinated vinyl chloride polymer, a partially crosslinked vinyl chloride polymer, a copolymer of vinyl chloride and another vinyl monomer. And a vinyl chloride copolymer. These vinyl chloride resins may be used alone or in combination of two or more.
Among these, with respect to the vinyl chloride copolymer, the proportion of other vinyl monomers used is preferably 30% by mass or less from the viewpoint of maintaining the original characteristics of the vinyl chloride resin. Examples of other vinyl monomers copolymerized with vinyl chloride include fatty acid vinyl esters such as vinyl acetate and vinyl propionate; alkyl methacrylates such as methyl methacrylate and ethyl methacrylate; olefins such as ethylene and propylene; Examples thereof include aromatic vinyl monomers such as styrene; alkyl vinyl ethers such as vinyl methyl ether and vinyl butyl ether; unsaturated carboxylic acids such as acrylic acid, methacrylic acid and maleic anhydride, or acid anhydrides thereof. These may be used alone or in combination of two or more.
The average degree of polymerization of the vinyl chloride resin is preferably in the range of 300 to 5000, and more preferably in the range of 500 to 3000. If the average degree of polymerization of the vinyl chloride resin is 300 or more, it tends to suppress the reduction of the foaming ratio and the mechanical properties of the foam molded article, and if it is 5000 or less, it tends to be able to suppress the deterioration of workability.
The production method of the vinyl chloride resin is not particularly limited, and examples thereof include an emulsion polymerization method, a suspension polymerization method, and a bulk polymerization method.

  The method for obtaining the vinyl chloride resin composition for foam molding of the present invention is not particularly limited, and a known melt-kneading method can be used. For example, a predetermined amount of vinyl chloride resin and processing aid for foam molding can be used. A vinyl chloride resin composition for foam molding can be obtained by kneading extruders such as single-screw extruders and twin-screw extruders that are mixed with Henschel mixers, Banbury mixers, V-type mixers, ribbon blenders, etc. These are manufactured by being molded into various desired shapes. Moreover, the vinyl chloride resin composition for foam molding of the present invention can be applied to any foam molding method such as free foam molding and Selka foam molding.

In the case where the vinyl chloride resin and the foaming molding processing aid are blended to obtain the vinyl chloride resin composition for foam molding of the present invention, depending on the purpose, the effects of the present invention are not impaired. In addition to foaming agents, various additives such as conventional stabilizers, lubricants, fillers, impact modifiers, and pigments can be added as necessary.
Examples of the foaming agent include azo foaming agents such as azobisisobutyronitrile and azodicarbonamide; N, N′-dinitrosopentamethylenetetramine, N, N′-dimethyl-N, N′-dinitrosotephthale Nitroso-based foaming agents such as amides; inorganic foaming agents such as sodium bicarbonate can be used, and these may be used alone or in combination of two or more.
Examples of stabilizers include lead stabilizers such as tribasic lead sulfate, dibasic lead phosphite, basic lead sulfite, and lead silicate, and metals such as potassium, magnesium, barium, zinc, cadmium, and lead. And metal soap stabilizers derived from fatty acids such as 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, hydroxystearic acid, oleic acid, ricinoleic acid, linoleic acid, behenic acid; Organotin-based stabilizers having an alkyl group, an ester group, a fatty acid group, a maleic acid group, a sulfide-containing group, etc .; Ba—Zn series, Ca—Zn series, Ba—Ca—Sn series, Ca—Mg— Composite metal soap-based stabilizers such as Sn-based, Ca-Zn-Sn-based, Pb-Sn-based, Pb-Ba-Ca-based; metal groups such as barium and zinc; 2-ethylhexanoic acid, isode Acids, branched fatty acids such as trialkylacetic acid, unsaturated fatty acids such as oleic acid, ricinoleic acid, linoleic acid, alicyclic acids such as naphthenic acid, aromatic acids such as carboxylic acid, benzoic acid, salicylic acid, and substituted derivatives thereof Metal salt stabilizers usually derived from two or more organic acids such as: These stabilizers are dissolved in organic solvents such as petroleum hydrocarbons, alcohols, glycerin derivatives, etc., and phosphites, epoxy compounds, coloring prevention In addition to metal stabilizers such as metal salt liquid stabilizers that contain stabilizers, transparency improvers, light stabilizers, antioxidants, bleed-out inhibitors, and lubricants, epoxy resin, epoxy Non-metallic stabilizers such as epoxy compounds such as epoxidized soybean oil, epoxidized vegetable oil, and epoxidized fatty acid alkyl esters, and organic phosphites. These may be used alone or in combination of two or more.
Examples of the lubricant include liquid hydrocarbons, natural paraffins, micro waxes, synthetic paraffins, pure hydrocarbon lubricants such as low molecular weight polyethylene, halogenated hydrocarbon lubricants, fatty acid lubricants such as higher fatty acids and oxy fatty acids, fatty acids In addition to fatty acid amide lubricants such as amides and bisfatty acid amides, lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids such as glycerides, polyglycol esters of fatty acids, fatty alcohol esters of fatty acids (ester waxes) and the like Metal soap, fatty alcohol, polyhydric alcohol, polyglycol, polyglycerol, fatty acid and polyhydric alcohol partial ester, fatty acid and polyglycol, polyglycerol partial ester. These may be used alone or in combination of two or more.
Examples of the filler include carbonates such as heavy calcium carbonate, precipitated calcium carbonate, and colloidal calcium carbonate, aluminum hydroxide, magnesium hydroxide, titanium oxide, clay, mica, talc, wollastonite, zeolite, silica, In addition to inorganic systems such as zinc oxide, magnesium oxide, carbon black, graphite, glass beads, glass fibers, carbon fibers, and metal fibers, organic fibers such as polyamide can be used. These may be used alone or in combination of two or more.
Examples of impact modifiers include polybutadiene, polyisoprene, polychloroprene, fluororubber, styrene-butadiene copolymer rubber, acrylonitrile-styrene-butadiene copolymer rubber, and styrene-butadiene-styrene block copolymer rubber. Styrene-isoprene-styrene block copolymer rubber, styrene-ethylene-butylene-styrene block copolymer rubber, ethylene-propylene copolymer rubber, and ethylene-propylene-diene copolymer rubber (EPDM). As the diene of EPDM, 1,4-hexadiene, dicyclopentadiene, methylene norbornene, ethylidene norbornene, propenyl norbornene and the like can be used. These impact modifiers may be used alone or in combination of two or more.
Furthermore, as the pigment, known organic pigments and inorganic pigments can be used, for example, organic pigments such as azo, nitroso, nitro, perinone, phthalocyanine, quinacridone, titanium oxide, and zinc oxide. Inorganic pigments such as iron oxide, sulfide, carbon black, carbonate, metal powder, chromate, ferrocyanide, sulfate, silicate, and phosphate It is done. These pigments may be used alone or in combination of two or more.
In addition, flame retardants such as chlorinated paraffin, aluminum hydroxide, antimony trioxide, halogen compounds, mold release agents, fluidity improvers, colorants, antistatic agents, surfactants, antifogging agents, antibacterial agents, etc. As long as the effect of the present invention is not impaired, it can be arbitrarily blended depending on the purpose.

The obtained vinyl chloride resin composition for foam molding can be applied to ordinary known molding methods such as injection molding, hollow molding, extrusion molding and the like in addition to foam extrusion molding to obtain various molded products. it can.
In addition, by various molding methods, a plate-like foam molded body, a cylindrical foam molded body, and an irregular-shaped foam molded body are obtained, and members for a wide range of building materials, synthetic wood, etc .; for display members, storage cases, etc. It can be used for foamed boards, industrial members that require heat insulation and heat retention.

  According to the processing aid for foam molding of the present invention, the vinyl chloride resin composition for foam molding can be efficiently kneaded and the melt strength can be increased, resulting in the formation of fine and uniform foam cells. In addition, it is possible to obtain a foamed molded article having a high foaming ratio and an excellent molded appearance.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to this Example. In each example and comparative example, “part” means “part by mass”.
The reduced viscosity (η _sp / c) was measured by dissolving 0.1 g of the polymer in 100 ml of chloroform and using an Ubbelohde viscometer at 25 ° C.

[Example 1]
In a reaction vessel equipped with a stirrer and a reflux condenser, 230 parts of deionized water was charged, 1.5 parts of sodium dioctylsulfosuccinate was further added, and the inside of the vessel was replaced with nitrogen gas. Thereafter, 0.15 part of potassium persulfate and 100 parts of isobutyl methacrylate were charged, the external temperature of the reaction vessel was raised to 65 ° C. while stirring, and the mixture was heated and stirred for 2 hours to complete the polymerization, thereby obtaining a latex.
The latex was cooled and spray-dried under the conditions of a drying gas inlet temperature of 160 ° C. and a drying gas outlet temperature of 70 ° C. to obtain a polymer powder. The reduced viscosity (η _sp / c) of the polymer was 9.7. The obtained polymer (A) powder was used as a foaming processing aid (B-1).
15 parts of the resulting foam molding processing aid (B-1) was mixed in the following composition, blending was terminated at an internal temperature of 90 ° C., and a vinyl chloride resin composition for foam molding was obtained.
Processing aid for foam molding 15 parts Vinyl chloride resin Average degree of polymerization: 700 (TK700: manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts Methyl tin mercaptide (TM-701: manufactured by Katsuta Chemical Co., Ltd.) 2 parts Calcium stearate (SAK- CS-G: manufactured by Shinagawa Chemical Co., Ltd.) 1 part fatty acid alcohol dibasic acid ester (LOXIOL G60: manufactured by Cognis Co., Ltd.) 0.8 part oxidized polyethylene wax (HI-WAX4202E: manufactured by Mitsui Chemicals, Inc.) 0. 7 parts Polyethylene wax (PE520: manufactured by Mitsui Chemicals) 0.1 part Composite wax (L-420: manufactured by Katsuta Chemical Co., Ltd.) 2 parts Lubricant (Metabrene L1000: manufactured by Mitsubishi Rayon Co., Ltd.) 0.5 part Talc (MS: Nihon Talc Co., Ltd.) 10 parts Foaming agent (Azodicarbonamide: Eiwa Kasei Co., Ltd.) 1 part Foaming agent (Baking soda: SC -P Eiwa Kasei Co., Ltd.) 0.7 parts Pigment (DA EP4820 Brown: manufactured by Dainichi Seika Co., Ltd.) 0.05 parts The obtained vinyl chloride resin composition for foam molding is a 30 mm single screw extruder. Extruded from a die shape having a diameter of 5 mm under a temperature condition of C1: 150 ° C., C2: 170 ° C., C3: 180 ° C., AD: 190 ° C., D: 190 ° C. Manufactured.
About the obtained foaming molding, the following (1)-(3) evaluation was performed.
(1) Specific gravity The obtained foamed molded article was cut and measured with an automatic specific gravity meter (AND-DMA-220: manufactured by Ando Keiki Seisakusho Co., Ltd.).
(2) Foam moldability The obtained foam molded article was cut at 10 locations, and the cut surface was observed. Foamed cells with a major axis exceeding 1 mm on each cut surface were counted and evaluated according to the following criteria.
A: Foamed cells exceeding 1 mm in major axis were not confirmed B: Foamed cells exceeding 1 mm in major axis were confirmed at 1 to 2 cut surfaces C: Foamed cells exceeding 1 mm in major axis were cut at 3 or more locations (3) Pigment dispersibility confirmed on the surface The surface of the obtained foamed molded article was observed, and the dispersibility of the pigment was evaluated according to the following criteria.
A: The pigment is uniformly dispersed. B: The pigment is partially dispersed unevenly. C: The pigment is dispersed unevenly. D: The pigment streaks are clearly confirmed. Ru

[Examples 2-3, Comparative Examples 1-8]
Except that the composition of the monomer component was changed to the ratio shown in Table 1, polymerization and spray drying were performed in the same manner as in Example 1 to obtain a polymer powder, a vinyl chloride resin composition for foam molding, A foamed molded product was obtained.

  Table 1 shows the evaluation results of the foamed molded articles obtained in Examples 1 to 3 and Comparative Examples 1 to 8.

Abbreviations in the table are as follows.
i-BMA: Isobutyl methacrylate n-BMA: n-butyl methacrylate t-BMA: t-butyl methacrylate MMA: methyl methacrylate n-BA: butyl acrylate n-OM: n-octyl mercaptan

As is clear from the results of Table 1, a foaming processing aid containing a polymer (A) obtained by polymerizing a monomer component (a) containing 65% by mass or more of isobutyl methacrylate was used. By performing foam molding, a molded article having excellent pigment dispersibility and foamability could be obtained. In particular, by using i-BMA, a remarkable effect is exhibited as compared with n-BMA and t-BMA, and the reduced viscosity (η _sp / c) of the polymer (A) is 4 or more. It should be noted that a remarkable effect is exhibited.

According to the processing aid for foam molding of the present invention, it is possible to obtain a foam molded article that forms fine and uniform foamed cells, has a high foaming ratio, and further exhibits an excellent molded appearance.
These foam moldings can be obtained by various molding methods to obtain plate-like foam moldings, cylindrical foam moldings, and irregular-shaped foam moldings, and members for a wide range of building materials, synthetic wood, etc .; display members, storage It can be used for foam boards oriented to cases and the like, and industrial members that require heat insulation and heat retention.

Claims (5)

Contains vinyl chloride resin, foaming processing aid and pigment,
The foam-forming processing aids, Ri polymer (A) Tona obtained by polymerizing a monomer component (a) containing isobutyl methacrylate 65 mass% or more,
A vinyl chloride resin composition for foam molding , in which 0.1 g is dissolved in 100 ml of chloroform and the reduced viscosity (ηsp / c) of the polymer (A) measured at 25 ° C. is 4 or more. The vinyl chloride resin composition for foam molding according to claim 1, wherein the monomer component (a) contains 76% by mass or more of isobutyl methacrylate. The vinyl chloride resin composition for foam molding according to claim 1 or 2, wherein the reduced viscosity (ηsp / c) of the polymer (A) measured at 25 ° C by dissolving 0.1 g in 100 ml of chloroform is 20 or less. Thing . The vinyl chloride resin composition for foam molding according to any one of claims 1, 2, and 3 containing 1 to 25 parts by mass of a processing aid for foam molding with respect to 100 parts by mass of the vinyl chloride resin. The foaming molding obtained by shape | molding the vinyl chloride-type resin composition for foam molding as described in any one of Claims 1-4 .