WO1997033936A1 - Vinyl chloride resin composition, molded product of the same, and process for producing them - Google Patents

Abstract

A vinyl chloride resin composition which contains (A) a vinyl chloride resin, (B) a methacrylic acid ester resin, (C) a thermally decomposable blowing agent, and (D) wood flour whose particles are coated with hard small particles and have an average particle size of 50-500 νm. Molded products obtained from this composition have a uniform and fine cellular structure, a smooth skin, and a large mechanical strength and is rich in woody texture. They are suited to building materials or furniture materials.

Description

 Description Vinyl chloride resin composition, molded articles thereof, and methods for producing them Technical field

 The present invention relates to a vinyl chloride resin composition containing wood flour, a molded article thereof, and a method for producing the same. More specifically, the present invention has a uniform and fine foamed cell structure and a smooth skin, and is rich in woody texture. The present invention relates to a vinyl chloride resin composition capable of providing a molded article suitable for building materials and furniture materials, a method for producing the same, and such a molded article and a method for producing the same. Background technology

 Since wood can be produced repeatedly by photosynthesis, it is being reviewed as a promising resource that is different from petroleum-based resins. Attempts are being made to grow forests with fast-growing species and reduce the concentration of carbon dioxide in the atmosphere to restore a healthy global environment, while at the same time planning to cut down and use wood as a resource for human life. It is taking place. Under these circumstances, vinyl chloride resin, a general-purpose resin that has high mechanical strength and is easy to process, is mixed with wood flour to form a vinyl chloride resin that is frequently used in building materials. If a product can be developed, a harmonious way to utilize global resources will be greatly pioneered.

 In the past, it has often been practiced to mix wood powder with vinyl chloride resin to form a wood-like appearance and feel similar to wood. However, there is a problem that since a considerable amount of wood flour must be blended, mechanical strength such as tensile strength is greatly reduced, and a natural wood texture cannot be realized.

In order to improve the clarity and ease of processing of wood grain, a vinyl chloride resin composition in which a urea resin is added in addition to wood powder has been proposed (Japanese Patent Application Laid-Open No. 60-42007). Japanese Patent Application Laid-Open No. Sho 60-73087, Japanese Patent Application Laid-Open No. Sho 60-37808). In addition to wood flour, inorganic fillers such as My power, and polyethylene and ethylene-vinyl acetate copolymer Alternatively, a vinyl chloride resin composition to which ABS resin is added has been proposed as having a low coefficient of linear expansion, and having excellent impact resistance and moldability (Japanese Patent Application Laid-Open No. 60-1992746). Gazette, Japanese Patent Laid-Open No. 60-192,477). However, even with these proposed techniques, the homogeneity of wood flour is not improved, and the appearance of the woody texture of the molded product is insufficient.

 A technique has been proposed to improve the uniformity of the dispersion of wood flour by blending wood flour to which inorganic powder or plastic powder is adhered during plastic processing (Japanese Patent Laid-Open Nos. 5-1777610, No. 5—2 617 078) However, resin molded products rich in woody texture have not yet been obtained. Disclosure of the invention

 In view of the above-mentioned circumstances, an object of the present invention is to have a uniform and fine foam cell structure and a smooth skin, and to provide a woody texture without lowering the mechanical strength inherent in a vinyl chloride resin molded article. An object of the present invention is to provide a vinyl chloride resin composition capable of providing a molded article which is rich and suitable for building materials such as window frames and furniture, and a molded article having such characteristics.

 Another object of the present invention is to provide a method for producing the above-mentioned vinyl chloride-based resin composition and the above-mentioned molded article in an industrially advantageous manner.

 The present inventors have found that the above-mentioned object is achieved by blending a wood powder which has been subjected to a specific treatment with a vinyl chloride resin in the presence of a methacrylate ester resin as a processing aid, followed by foam molding. The inventors have found that this has been achieved, and have completed the present invention based on this finding.

 According to the present invention, in one aspect, (A) vinyl chloride resin, (B) methyl acrylate resin, (C) pyrolytic foaming agent, and (D) hard small particles adhere to the surface. The present invention provides a vinyl chloride resin composition containing wood powder having an average particle size of 50 to 500 m.

According to the present invention, in another aspect, (A) a vinyl chloride resin, (B) a methyl acrylate resin, and (D) an average particle diameter of 50 having hard small particles adhered to the surface. The present invention provides a vinyl chloride resin molded article containing wood powder of up to 500 m and having fine cells uniformly distributed.

 According to the present invention, in another aspect, (A) a vinyl chloride resin, (B) a methacrylic acid ester resin, and (D) an average particle diameter of 50 to 5 having hard small particles adhered to the surface. The temperature was raised to 120 to 160 while mixing the wood powder of 100 m, then the resulting mixture was transferred to a cooling mixer, and (C) a pyrolytic foaming agent was added and mixed. Provided is a method for producing a vinyl chloride-based resin composition, wherein the composition is cooled while cooling. ―

 According to the present invention, in still another aspect, (A) a vinyl chloride resin, (B) a methacrylic acid ester resin, and (D) an average particle diameter of 50 to which hard small particles are adhered to the surface. The temperature was raised to 120 to 160 while mixing wood flour of up to 500 m, the resulting mixture was transferred to a cooling mixer, and (C) a pyrolytic foaming agent was added and mixed. The present invention provides a method for producing a vinyl chloride resin extrudate, which comprises extruding the obtained vinyl chloride resin composition at 50 to 60. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described in detail.

The vinyl chloride resin used as the component (A) in the composition of the present invention contains not only a homopolymer of vinyl chloride but also a copolymer in which vinyl chloride accounts for 50% by weight or more. Examples of the comonomer used in the production of the vinyl chloride copolymer include: olefins such as ethylene and propylene; halogenated olefins such as aryl chloride, vinylidene chloride, vinyl fluoride, and ethylene trifluoride: vinyl acetate. Carboxylic acid vinyl esters, such as vinyl propionate; vinyl ethers, such as isobutyl vinyl ether and cetyl vinyl ether; aryl ethers, such as allyl 3-chloro-2-oxypropyl ether and aryl glycidyl ether; acrylic acid; Unsaturated carboxylic acids, such as maleic acid, itaconic acid, 2-hydroxyethyl acrylate, methyl methacrylate, monomethyl maleate, getyl maleate, and maleic anhydride; esters or anhydrides thereof; two Unsaturated nitriles such as tolyl and methacrylonitrile; acrylamide, N-methylolacrylamide, acrylamide-2-methylpropanesulfonic acid, (meth) acrylamide propyltrimethylammonium chloride And acrylamides such as arylamine benzoate and diaryldimethylammonium chloride, and derivatives thereof. The monomers exemplified above are only a part of the copolymerizable monomers. “Polyvinyl Chloride” edited by Kinki Chemical Association Vinyl Subcommittee Nikkan Kogyo Shimbun (1989) 755-1 Various monomers exemplified on page 04 can be used. In addition, vinyl chloride or vinyl chloride can be copolymerized with a resin such as ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, or chlorinated polyethylene. A resin obtained by graft polymerization with a monomer is also included.

 These vinyl chloride resins may be produced by any conventionally known production method such as suspension polymerization, emulsion polymerization, solution polymerization, or bulk polymerization. The average polymerization degree is preferably in the range of 400 to 1,500 according to the measurement method specified in JISK6721, more preferably in the range of 600 to 1,100. Some are used. If the average degree of polymerization of the vinyl chloride resin is less than 400, the expansion ratio tends to be difficult to increase, and if it is more than 1,500, a large number of coarse cells may be present in the foam cells. .

The methacrylic acid ester-based resin used as the component (II) in the present invention is a homopolymer of methacrylic acid ester and a copolymer in which the methacrylic acid ester unit accounts for 50% by weight or more. Preferred methacrylic acid ester-based resins include, in addition to a homopolymer of methyl methacrylate, a monomer copolymerizable with methyl methacrylate, ie, ethyl acrylate, butyl acrylate, and acrylic acid. It is a copolymer with one or more monoethylenically unsaturated monomers such as ethoxyxetil, 2-ethylhexyl methacrylate, 2-hydroxypropyl methacrylate, acrylonitrile, and vinyl acetate. Those containing more than 88% by weight, more preferably 90% by weight or more, of methyl methacrylate units are used. When the content of methyl methacrylate is less than 88% by weight, the expansion ratio tends to decrease. is there.

 The particle structure of the methacrylate ester resin as the component (B) may be a polymer composition having a substantially uniform inside of the particles, or a methacrylate ester polymer disclosed in Japanese Patent Publication No. 5-38014. That is, a resin such as a resin in which the inside of a particle is a copolymer of methyl methacrylate and acrylate and the outside is coated with a polymer of methyl methacrylate alone or a copolymer mainly composed of methyl methacrylate. The resin particles may have a stepped structure.

 The methacrylic acid ester-based resin used as the component (B) has a specific viscosity of 0.10 to 3.50 at 25 in a 10-milliliter form solution of Om1 in which 0.2 gr is dissolved. More preferably, it is more preferably in the range of 0.30 to 3.00. If the value of the specific viscosity is less than 0.10, the surface of the molded article tends to be rough, and if it exceeds 1.00, time may be required for uniform melting.

 The methacrylic acid ester resin as the component (B) has an effect of improving the melt viscosity characteristics of the vinyl chloride resin, maintaining the film strength of the foamed cell, and making it harder to break. The compounding amount of the component (B) in the composition of the present invention is preferably 5 to 30 parts by weight, more preferably 5 to 25 parts by weight, per 100 parts by weight of the vinyl chloride resin of the component (A). . When the amount of the compounding S is less than 5 parts by weight, the holding strength of the film strength during foaming is weakened, and the foamed cells are easily broken. On the other hand, if the amount exceeds 30 parts by weight, the melt viscosity becomes high, and the heat generation becomes large, so that the resin tends to be thermally degraded, and the size of the foam cell tends to be uneven.

As the thermal decomposition type foaming agent which is the component (C) of the composition of the present invention, at least one selected from a thermal decomposition type organic foaming agent and a thermal decomposition type inorganic foaming agent is used. Examples of the former are nitroso compounds such as N, N'-dinitrosopentamethylenetetramine and N, N'-dimethyl-N, Ν'dinitrosoterephthalamide; azodicarbonamide, azobisisobutyronitrile, etc. And sulphonyl hydrazides such as benzenesulfonyl hydrazide, ρ, ρ'-oxybis (benzenesulfonyl hydrazide) and toluenesulfonyl hydrazide. Examples of the latter include sodium bicarbonate, ammonium bicarbonate, and ammonium carbonate. Monium and the like. The organic and inorganic pyrolytic foaming agents described above can be used alone or in combination of two or more.

 In the present invention, it is not possible to use a low-boiling organic compound such as trifluoromethane, trichloroethane, petroleum ether or the like as a cell forming agent by heating and volatilizing the compound instead of the above-mentioned pyrolytic foaming agent. Appropriate. This is because the foam cells become coarse, making it difficult for the molded product to be nailed or screwed, making it unsuitable for building materials. In the composition of the present invention, the blending amount of the pyrolytic foaming agent of the component (C) is preferably 0.1 to 3.0 parts by weight per 100 parts by weight of the vinyl chloride resin of the component (A). Preferably it is 0.5 to 1.5 parts by weight. If the amount of the component (C) is less than 0.1 part by weight, the resulting molded article tends to lack a woody feeling due to a low expansion ratio. The surface of the product tends to be rough and the surface hardness tends to decrease.

 In the composition of the present invention, wood flour having an average particle diameter of 50 to 500 / zm having hard small particles adhered to the surface is used as the component (D).

Hard small particles are particles having a hardness greater than that of wood flour and an average particle size smaller than the average particle size of wood flour, such as metals, metal oxides and metal salts, inorganic compounds, and plastic particles. And the like. Preferred components (D) are inorganic or metal-based particles such as titanium oxide, nickel, calcium carbonate, silica, and myriki. Wood flour having small hard particles adhered to the surface used in the present invention is disclosed in JP-A-5-177610 and JP-A-5-216708. The mode in which the hard small particles adhere to the wood flour surface is a hard bond, such as a hugging bond including biting of the hard small particles into the wood flour, a narrowing bond between a plurality of hard small particles that are bite bonded to each other. Small particles may be adhered to the surface of wood flour by an external force, or hard small particles may be adhered to wood flour using an adhesive. The type of wood flour is not particularly limited, and wood such as coniferous and hardwood timber chips, such as cedar, rugga, and lauan, planing shavings, and sawdust can be used. In order to obtain the component (D) of the present invention from these woods, for example, the woods are converted into relatively rounded wood flour having an average particle size of 500 / zm or less by a pulverizer, and then together with hard small particles Dust explosion, such as in a nitrogen atmosphere, charged in a ball mill Ball milling under the conditions in which is prevented.

 The adhesion amount of the hard small particles is 1 to 50% by weight, preferably 5 to 30% by weight, based on the total weight of the wood flour and the small particles after the adhesion treatment. If the amount of the hard small particles is less than 1% by weight, the wood flour tends to be fibrous and agglomerate, while if it is more than 50% by weight, the wood texture may be reduced.

 The average particle size of the component (D) used in the present invention is from 50 to 500 / m, preferably from 50 to 100 m. Here, the average particle size refers to a reading of the value of the mesh corresponding to 50% by weight of a curve obtained by analyzing the powder by sieve analysis to obtain a cumulative weight% curve relative to the mesh. If the average particle size of the component (D) is smaller than 50 im, the bulk specific gravity is reduced, and the mixing operability for preparing the composition is deteriorated. If it is larger than 500 m, the surface of the molded article becomes rough. And the expansion ratio decreases.

 The water content of the component (D) is preferably at most 10% by weight, more preferably at most 5% by weight.

 In addition to the above components, the composition of the present invention includes, in addition to the heat stabilizers and lubricants used in the processing of ordinary vinyl chloride resins, ultraviolet absorbers, impact-resistant reinforcing agents, pigments, plasticizers, An antistatic agent or the like is appropriately added.

 To prepare the composition of the present invention, first, components (A), (B) and (D) excluding the thermally decomposable foaming agent of component (C) are put together in a mixer such as a Henschel mixer. The temperature is raised to 120 to 160 while mixing. Mixing is preferably performed with vigorous stirring. In this mixing process, the moisture absorbed in the wood flour is volatilized. When the above temperature is reached, transfer the mixture to a cooling mixer, add the pyrolytic foaming agent of component (C), and lower the temperature to 50-60. The extracted powdery mixture can be used as a molding compound as it is, but is usually pelletized. As a preferable method for preparing a bellet, a method of producing a pellet at 150 to 170 using a twin-screw extruder while discharging residual moisture in wood flour from a vent hole is mentioned.

In the above method for preparing the composition of the present invention, all components except the blowing agent are added and mixed together at the time of initial mixing with a Henschel mixer or the like, so that the specific gravity is large. In addition, a mixture in which additives such as pigments are uniformly dispersed can be obtained.

 The molding method for obtaining a vinyl chloride resin molded product similar to natural wood using the composition of the present invention is not particularly limited, but an extrusion molding method is preferably employed. The conditions for extrusion molding are the same as those for extrusion molding of general vinyl chloride resin.

 Thus, the obtained extruded foam molded article has fine cells uniformly distributed. Usually, the average cell diameter is less than 100. In addition, the expansion ratio of the extruded foamed molded product is preferably 1.5 to 2.0. If the expansion ratio is too low, the essential feeling will be poor, and if the expansion ratio is too high, the mechanical strength will decrease. The shape of the extruded product may be in accordance with the use of building materials and furniture materials, and generally includes plate, sheet, prism, column, and irregular shapes.

 Next, the resin composition of the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these examples. The number of copies is based on weight.

 The properties of the foam molded article were examined by the following methods.

 1) Foam cell condition

 Observe the cut surface of the molded product with an optical microscope and evaluate based on the following 4 grades

A: The cell is fine and uniform with a diameter of 100 or less.

 B: Coarse cells are broken and coarse.

 C: Many cells are destroyed and coarse.

 D: Most of the cells are broken and coarse.

 2) Surface properties of molded products

 The surface of the molded product is visually observed and touched, and evaluated based on the following 4 grades.

A smooth

 B slightly shark skin

 C 鲛 skin

D Many granular protrusions. 3) True specific gravity and molded product specific gravity

 Measured by the underwater displacement method according to JISK 711.

 4) Molded product expansion ratio

 Using the value of the specific gravity obtained by the above measurement, it is obtained by the following equation.

 Expansion ratio-true specific gravity

 5) Tensile strength

 It is measured at a tensile speed of 1 Omm mm i η using the No. 1 test piece of JIS K 7 11 13. A wood flour sample having hard particles adhered to the surface was obtained as follows.

 1) Wood powder coated with titanium oxide

 A commercially available product manufactured by Misa Techno Co., Ltd., No. 60-No. 5-3 was used. Titanium oxide content 5% by weight, average particle size 60 ixm, water content 5% (referred to as surface-treated wood flour 1).

2) Calcium carbonate coated wood flour

 100 parts by weight of wood powder with an average particle size of 80 / zm sold by Shimada Shokai Co., Ltd. (trade name: Celluunt) and calcium carbonate with an average particle size of 3.6 / zm manufactured by Shiraishi Industry Co., Ltd. (trade name: Why Tons B) and 20 parts by weight were charged into a ball mill (Atraita A200, manufactured by Mitsui Miike Kakoki Co., Ltd.) using a ceramic pole and operated for 3 hours under a nitrogen atmosphere. The amount of calcium carbonate deposited on the obtained sample was measured by the combustion method.6.

It was 2% by weight. The average particle size was 55 m and the moisture content was 5% (referred to as surface-treated wood flour 2).

 In addition, wood powder coated with calcium carbonate was obtained in the same manner as described above, using wood powder having an average particle size of 700 m obtained from a synthetic wood board manufacturer. The amount of calcium carbonate attached was 8.0% by weight, the average particle size was 600 / m, and the water content was 5% (referred to as surface-treated wood flour 3). Examples 1-2, Comparative Examples 1-5

The components of the types and amounts shown in Table 1 were blended using a Henschel mixer in the following manner. Water vapor was volatilized while vinyl chloride resin, methacrylate ester resin (except for Comparative Example 1), wood flour, heat stabilizer, lubricant, filler, and pigment were charged and mixed. When the temperature rose to 140, the mixture was transferred to a cooling mixer and mixed, and after the temperature had dropped to 60, the blowing agent was added. The obtained powdery mixture was formed into pellets using a single-screw extruder having a cylinder diameter of 65 mm under the following conditions. Water remaining in the wood flour was volatilized from the vent hole.

Screw: LZD = 24, compression ratio 2.5, the rotation number 3 O r pm set temperature: in _{Ci = 1 30, c 2 =} 1 4 or, in C ₃ = 1 50

C ₄ = 16 With a head of 160, a die of 160 ”dice: 3111111 (|) ぺ let 12 holes

 Land length: 10 mm

 The pellets thus obtained were extruded and foamed by a single screw extruder having a cylinder diameter of 4 Omm under the following conditions. Table 1 shows the properties of the obtained plate-like foam molded article.

Screw: LZD = 22, compression ratio 2.5, rotation speed 2 5 r pm set temperature: Ci = 1 40:, C 2 = 1 6 0 ", C 3 = 1 7 Ot:

C ₄ = 1 80: with head 160, Di = 160 t:

D ₂ = 16 O:

 Dice: thickness 4mm width X 50mm belt

Land length: 5 mm

* 1 ZEST 700 L, manufactured by Shin-Daiichi PVC Co., Ltd., vinyl chloride resin Average polymerization degree 680

 * 2 Hyprene B403, manufactured by Nippon Zeon Co., Ltd., a copolymer having a methyl methacrylate unit content of about 91% by weight, specific viscosity Sampled at 25T :) 2.00

 * 3 CellJunt, manufactured by Shimada Shokai Co., Ltd., wood flour, average particle size 80 zm, moisture 5% by weight

* 4 Tribasic lead sulfate / lead stearate composite heat stabilizer * 5 polyethylene wax

 * 6 Calcium carbonate CCR, manufactured by Shiraishi Calcium Co., Ltd., average particle size 0.02 II m

 * 7 Ribon Bon Black (TPH 00 12; manufactured by Toyo Ink Mfg. Co., Ltd.) / Condensed Azo Red (TXH4360; manufactured by the company) Z Bisazoyello (TXH 2110, manufactured by the company) Compound pigment

 The extruded product (Examples 1 and 2) molded using the composition having the requirements of the present invention has a good expansion cell state and surface properties, has a sufficient expansion ratio, and satisfies the tensile strength. Was something.

 In Comparative Example 1 in which the methacrylic acid ester-based resin was not blended, the foam cell state, surface properties, and foaming ratio were all poor. In Comparative Example 2 in which a non-pyrolytic foaming agent (trichloroethane) was used as the foaming agent, a molded product having a large foaming ratio but insufficient cell state and surface properties was obtained. Naturally, if the foaming agent is not added, the molded article does not have cells and thus has no woody feel (Comparative Example 3).

 When the wood flour does not have hard small particles, a molded article having insufficient foam cell state, surface properties and foaming ratio is obtained (Comparative Example 4). Wood flour having a large particle size results in a molded article having significantly expanded cell state and surface properties (Comparative Example 5). Industrial applicability

 The molded article of the vinyl chloride resin composition of the present invention has a uniform and fine foamed cell structure and a smooth skin, has high mechanical strength, and is rich in woody feel.

 Therefore, this molded product is suitable as a building material or a furniture material.

Claims

The scope of the claims 1. (A) Vinyl chloride resin, (B) Methacrylic acid ester resin, (C) Pyrolytic foaming agent, and (D) Average particle size of 50-500 / m with hard small particles attached to the surface A vinyl chloride resin composition containing wood flour.  2. 100 to 100 parts by weight of vinyl chloride resin (A), 5 to 30 parts by weight of methacrylate resin (B) and 0.1 to 100 parts by weight of pyrolytic foaming agent (C) 3. The vinyl chloride resin composition according to claim 1, wherein the amount of the wood powder (D) is 3.0 parts by weight and the amount of the small particle-attached wood powder (D) is 5 to 100 parts by weight.  3. The claim 1 or 2 wherein the methacrylate ester resin is a methyl methacrylate homopolymer or a copolymer containing more than 88% by weight of methyl methacrylate monomer units. The vinyl chloride resin composition as described in the above.  4. The methacrylic acid ester-based resin according to claim 1, having a specific viscosity of 0.1 to 3.50 in 25 of 100 ml of a mouth-form solution in which 0.2 gr is dissolved. Item 4. The vinyl chloride resin composition according to any one of Items 3 to 3.  5. The hard small particles are at least one selected from the group consisting of metals, metal oxides and metal salts, other inorganic compounds, and plastic particles, according to any one of claims 1 to 4. Vinyl chloride resin composition.  6. The method according to any one of claims 1 to 5, wherein the amount of the hard small particles attached to the wood powder is 1 to 50% by weight based on the total weight of the wood powder to which the small particles are attached. Vinyl chloride resin composition.  7. Do not contain (A) vinyl chloride resin, (B) methyl acrylate resin, and (D) wood powder with an average particle size of 50 to 500 m with hard small particles attached to the surface. A vinyl chloride resin molded product with fine cells distributed uniformly.  8. With respect to 100 parts by weight of vinyl chloride resin (A), the amount of methacrylic acid ester resin (B) is 5 to 30 parts by weight, and the amount of small particle-attached wood flour (D) is 5 to 1 parts. 8. The vinyl chloride resin molded article according to claim 7, wherein the amount is 00 parts by weight. 9. The method according to claim 7, wherein the average cell diameter is 100 m or less. Biel chloride resin molded product.  10. The vinyl chloride resin molded article according to claim 9, wherein the foaming ratio is 1.5 to 2.0.  1 1. (A) Vinyl chloride resin, (B) Methacrylic acid ester resin and ( C) and (D) The temperature is increased to 120-160 while mixing wood powder having an average particle size of 50-500 m with hard small particles adhered to the surface, and then the resulting mixture is cleaned. (C) a method for producing a vinyl chloride resin composition, which comprises adding a pyrolytic foaming agent, cooling while mixing.  1 2. 100 to 100 parts by weight of vinyl chloride resin (A), 5 to 30 parts by weight of methyl acrylate resin (B) and 0.1 to 3 parts of pyrolytic foaming agent (C) 21. The method for producing a vinyl chloride resin composition according to claim 11, wherein 0 parts by weight and 5 to 100 parts by weight of the small particle-attached wood powder are used.  1 3. (A) vinyl chloride resin, (B) methacrylate ester resin and ( D) Mix the wood powder with an average particle size of 50-500 m with hard small particles attached to the surface, raise the temperature to 120-160, and transfer the resulting mixture to a cooling mixer (C A method for producing an extruded product of a vinyl chloride resin, characterized by adding a pyrolytic foaming agent, cooling while mixing, and then extruding the obtained 50 to 60 biel chloride resin composition. .  1 4. 100 to 100 parts by weight of vinyl chloride resin (A), 5 to 30 parts by weight of methacrylate resin (B) and 0.1 to 3.0 parts by weight of pyrolytic foaming agent (C) The method for producing an extruded product according to claim 13, wherein 5 to 100 parts by weight of the wood flour with small particles and small particles are used.