JPH11189693A - Vinyl chloride resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinyl chloride resin compsn. which can give a highly expanded molded vinyl chloride resin article which has a homogeneous cell structure and a smooth surface, is rich in woody feeling, and is suitable for materials for buildings or furniture. SOLUTION: This compsn. comprises (A) 100 pts.wt. vinyl chloride resin, (B) 20-150 pts.wt. wood flour having an average particle size of 50-500 μm, (C) a thermoplastic resin having epoxy groups and compatible with vinyl chloride resin, (D) a methyl methacrylate copolymer contg. at least 60 wt.% methyl methacrylate units, and (E) a thermally decomposable blowing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin composition containing a large amount of wood flour. More specifically, the present invention relates to a vinyl chloride resin composition capable of providing a highly foamed molded article rich in a woody feel and suitable for building materials and furniture.

[0002]

2. Description of the Related Art In recent years, a molding method has been practiced in which wood powder is blended with a vinyl chloride resin and foamed for the purpose of producing an appearance and feel similar to wood. However, a foamed vinyl chloride resin product containing a considerable amount of wood flour has a problem that its mechanical strength such as tensile strength is not sufficient.

[0003] 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 flour has been proposed (Japanese Patent Application Laid-Open No. Sho 60-42007, JP-A-60-73807, JP-A-60-73
808). In addition, a vinyl chloride resin composition obtained by adding an inorganic filler such as mica in addition to wood flour and polyethylene, ethylene-vinyl acetate copolymer or ABS resin has a low coefficient of linear expansion, impact resistance and moldability. (JP-A-60-192746,
JP-A-60-192747). However, these also lack the uniform mixing property of wood flour and the appearance of the woody texture of the molded product is insufficient. By blending wood powder to which inorganic powder or plastic powder is attached at the time of plastic processing, the uniform dispersibility of wood powder is greatly improved (JP-A-5-177610, JP-A-5-261708).
Simply blending such wood flour into a vinyl chloride resin has made it difficult to extrude a molded product rich in wood texture, especially a foam molded product having satisfactory mechanical strength.
That is, in the case of foam molding in which the amount of wood flour per 100 parts by weight of the vinyl chloride resin is from 20 to 150 parts by weight of wood flour, the wood flour is often released from the resin continuous layer and the stress is reduced. In such a case, a crack surface was easily generated at the wood powder interface. Therefore, the appearance of a vinyl chloride-based resin composition that can provide a foam molded article having a high content of wood flour and improved mechanical strength has been awaited.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a highly foamed molded article which is rich in a woody texture and is suitable for building materials such as window frames and furniture. An object of the present invention is to provide a system resin composition.

[0005]

Means for Solving the Problems The present inventors have solved the above-mentioned problem by using a specific epoxy group-containing polymer and a specific methyl methacrylate-based copolymer together with a vinyl chloride resin together with wood powder. It has been found that the above-mentioned object is achieved by foam molding in advance, and the present invention has been completed based on this finding. That is, the present invention provides (1)
(A) 100 parts by weight of a vinyl chloride resin, (B) 20 to 150 parts by weight of wood powder having an average particle size of 50 to 500 μm, (C) a thermoplastic resin containing an epoxy group and being compatible with the vinyl chloride resin, (D) a vinyl chloride resin composition containing a methyl methacrylate copolymer containing 60% by weight or more of methyl methacrylate units and (E) a pyrolytic foaming agent, (2) (A) a vinyl chloride resin 100 parts by weight,
(B) 20 to 150 parts by weight of wood powder having an average particle size of 50 to 500 μm, (C) containing 0.3 to 10% by weight of an epoxy group,
A thermoplastic resin compatible with a vinyl chloride resin is used in an amount such that the epoxy group content is 0.01 to 0.2% by weight based on the total amount of (A), (B) and (C), (D ) A vinyl chloride resin composition comprising 7 to 30 parts by weight of a methyl methacrylate copolymer containing 60% by weight or more of a methyl methacrylate unit and (E) 0.1 to 3.0 parts by weight of a pyrolytic foaming agent. And (3) a thermoplastic resin compatible with the vinyl chloride resin, having an average degree of polymerization of 200 to 1,000.
Vinyl chloride copolymer or a weight average molecular weight of 20,0
The present invention provides the vinyl chloride resin composition according to the above (1) or (2), which is a methyl methacrylate copolymer or an acrylonitrile-styrene copolymer of from 0 to 3,000,000. Further, as a preferred embodiment, (4) a methyl methacrylate copolymer containing 60% by weight or more of methyl methacrylate units has a glass transition point of 50 to 85 ° C. and a specific viscosity of 1.5 to 4.0. The vinyl chloride resin composition according to any one of the above (1) to (3), and (5) a plasticizer 1 (F).
-20 parts by weight, (G) 0.5-10.0 parts by weight of metal soap, and (H) polyethylene wax 0.1-5.0.
It is intended to provide a vinyl chloride resin composition according to any one of the above (1) to (4), which contains parts by weight.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The vinyl chloride resin used as the component (A) in the composition of the present invention includes, in addition to a vinyl chloride homopolymer,
Copolymers containing 50% by weight or more, preferably 70% by weight or more of vinyl chloride units are included. However, the vinyl chloride copolymer as the component (A) does not contain an epoxy group. Examples of the comonomer in the case of the vinyl chloride copolymer include olefins such as ethylene and propylene; allyl chloride, vinylidene chloride, vinyl fluoride, and the like.
Halogenated olefins such as ethylene trifluoride chloride;
Carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as isobutyl vinyl ether and cetyl vinyl ether; allyl ethers such as allyl-3-chloro-2-oxypropyl ether; acrylic acid, maleic acid, itaconic acid; Unsaturated carboxylic acids such as 2-hydroxyethyl acrylate, methyl methacrylate, monomethyl maleate, diethyl maleate and maleic anhydride; esters or acid anhydrides thereof; unsaturated nitriles such as acrylonitrile and methacrylonitrile; Acrylamides such as acrylamide, N-methylolacrylamide, acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidopropyltrimethylammonium chloride; allylamine benzoate Salts, such as allylamine and its derivatives such as diallyl dimethyl ammonium chloride can be mentioned. The above exemplified monomers are only a part of copolymerizable monomers, and are described in "Polyvinyl Chloride" edited by Kinki Chemical Society Vinyl Subcommittee, Nikkan Kogyo Shimbun (1988).
Various monomers exemplified on pages 75 to 104 can be used. Further, a resin such as ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, chlorinated polyethylene, or vinyl chloride or a copolymerizable monomer described above with vinyl chloride. And resins obtained by graft polymerization of

[0007] These vinyl chloride resins are prepared by suspension polymerization,
It may be produced by any conventionally known production method such as emulsion polymerization, solution polymerization and bulk polymerization. The average degree of polymerization of the vinyl chloride resin is preferably from 400 to 1,500, more preferably from 600 to 1,100, as determined by the measurement method specified in JIS K 6721. Average degree of polymerization of vinyl chloride resin is 400
If it is smaller, the foaming ratio tends to be hardly increased. Conversely, if it is larger than 1,500, many coarse cells may be mixed in the foam cells.

In the present invention, as the component (B), wood powder having an average particle size of 50 to 500 μm is contained in an amount of 30 to 150 parts by weight, preferably 35 to 120 parts by weight, per 100 parts by weight of the vinyl chloride resin (A). Preferably 40 to 100
Used by weight. If the amount of the wood flour is less than 30 parts by weight, it is difficult for the molded article to exhibit a woody feeling, and if it exceeds 150 parts by weight, the molded article becomes brittle. The tree species of the wood flour used in the present invention is not particularly limited, and coniferous or hardwood wood pieces such as cedar, hemlock and lauan, and wood such as planing and sawdust can be used. In order to obtain the component (B) of the present invention from these woods, for example, the woods are milled to have an average particle diameter of 50.
It is preferable to use a relatively rounded wood flour of 0 μm or less. The wood flour used in the present invention is disclosed in JP-A-5-17761.
Wood powder having hard small particles adhered to the surface as disclosed in Japanese Patent Application Laid-Open No. H05-261708 and Japanese Patent Application Laid-Open No. 5-261708 may be used. As the hard small particles, particles having a hardness higher than that of wood flour and an average particle size smaller than the average particle size of wood flour are used. Specific examples include metals, metal oxides and metal salts, inorganic compounds, and plastic particles. Preferred small particles are inorganic or metallic particles such as titanium oxide, nickel, calcium carbonate, silica, and mica. The mode in which hard small particles adhere to the wood flour surface is
Adhesion due to external pressing force on the wood flour surface, such as an entanglement bond including biting of hard small particles into wood flour, a pinch connection between a plurality of bite-bonded hard small particles, etc. Alternatively, hard small particles may be attached to wood flour by an adhesive. In this case, the wood flour is charged into a ball mill or the like together with 1 to 50% by weight of hard small particles, and treated under a condition in which dust explosion is prevented such as in a nitrogen atmosphere. The average particle size of the component (B) used in the present invention is 50 to 500 μm, preferably 30 to 100 μm.
μm. Here, the average particle diameter means 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 with respect to the mesh. If the average particle size of the component (B) is less than 50 μm, the bulk specific gravity becomes small, and the mixing operability for preparing the composition becomes poor. If it is more than 500 μm, the molded product surface becomes rough and the expansion ratio decreases.
The water content of the component (B) is preferably at most 10% by weight, more preferably at most 5% by weight.

In the present invention, as the component (C), an epoxy group-containing thermoplastic resin serving as a compatibilizer for blending the wood powder of the component (B) with the vinyl chloride resin (A) in the continuous layer is used. The content of the epoxy group is preferably 0.3 to 10% by weight of the thermoplastic resin. If the epoxy group content exceeds 10% by weight, and if it is less than 0.3% by weight, there is a risk that the compatibility with the vinyl chloride resin is reduced, and therefore, the mechanical strength of the molded article is reduced. is there. The thermoplastic resin serving as the base to which the epoxy group is attached must be compatible with the vinyl chloride resin as the component (A). Examples of such a thermoplastic resin include a copolymer containing vinyl chloride as a main component (hereinafter, simply referred to as a vinyl chloride copolymer; the same applies hereinafter), a methyl methacrylate copolymer, an ethyl acrylate copolymer, and ethyl methacrylate. Copolymer, acrylonitrile-styrene copolymer, vinylidene chloride copolymer, vinyl acetate copolymer, vinyl propionate copolymer, chlorinated polyethylene, thermoplastic polyurethane, ethylene-vinyl acetate rubber (EV
A) Graft vinyl chloride copolymer, acrylic rubber graft vinyl chloride copolymer, NBR, MBS, MAS and the like. Among these thermoplastic resins, a vinyl chloride copolymer, a methyl methacrylate copolymer and an acrylonitrile-styrene copolymer are particularly preferred. The compounding amount of the component (C) is such that the amount of the epoxy group contained in the component (C) is 0.1 to the total amount of the components (A), (B) and (C).
The amount is preferably from 0.01 to 0.2% by weight, more preferably from 0.02 to 0.18% by weight. (C)
If the amount of the component exceeds 0.2% by weight of the epoxy group, the proportion of the vinyl chloride resin (A) is relatively reduced, and there is a risk that the mechanical strength of the foam molded article is reduced. . If the content is less than 0.01% by weight, the distribution of wood powder may be uneven, the expansion ratio may not be improved, or the strength of the molded product may not be improved. By adding the component (C), the wood flour (B) is uniformly dispersed in the vinyl chloride resin (A), the fluidity during molding is improved, and the mechanical strength of the molded product is improved. .

The average polymerization degree of the epoxy group-containing vinyl chloride resin as the component (C) is preferably from 200 to 1,000, more preferably from 300 to 800.
If the average degree of polymerization is larger than 1,000, it may be difficult to homogenize the composition during mixing, and if it is smaller than 200, the mechanical strength of the wood flour may not be improved. It is also possible to use an epoxy group-containing vinyl chloride resin having a gel component insoluble in a solvent such as methyl ethyl ketone or tetrahydrofuran, but in this case, the weight average molecular weight excluding the gel component is preferably in the above range. In the epoxy group-containing methyl methacrylate copolymer and the epoxy group-containing acrylonitrile-styrene copolymer, the weight average molecular weight is preferably from 20,000 to 3,000,000, more preferably from 100,000 to 1,000,000. , 0
00,000. Weight average molecular weight of 3,000,0
When it is larger than 00 or smaller than 20,000, the same inconvenience may occur as when the average degree of polymerization of the epoxy group-containing vinyl chloride copolymer is larger than 1,000 or smaller than 200, respectively. .

The vinyl chloride copolymer as component (C) preferably contains at least 70% by weight, preferably at least 80% by weight of vinyl chloride monomer units. If it is less than 70% by weight, the tensile strength of the obtained molded article may be reduced. Examples of the epoxy group-containing monomer copolymerized with vinyl chloride include glycidyl ethers of unsaturated alcohols such as allyl glycidyl ether and methallyl glycidyl ether; glycidyl methacrylate, glycidyl acrylate, glycidyl-p-vinylbenzoate, and methyl glycidyl. Glycidyl esters of unsaturated acids such as itaconate, glycidyl ethyl malate, glycidyl vinyl sulfonate, glycidyl allyl sulfonate, glycidyl methallyl sulfonate; butadiene monooxide, vinylcyclohexene monooxide,
Epoxide olefins such as 2-methyl-5,6-epoxyhexene; and the like.

The epoxy group-containing vinyl chloride copolymer as the component (C) is a copolymer of vinyl chloride and an epoxy group-containing monomer. May be contained in the component.
This second comonomer has the properties of the vinyl chloride copolymer,
For example, vinyl chloride resin (A) such as wood flour (B) and other pigments
It can be selected and used to adjust the compatibility with water and the processability and fluidity of the entire composition. Examples of the second comonomer include vinyl esters such as vinyl acetate and vinyl propionate; olefins such as ethylene and propylene; vinyl ethers such as cetyl vinyl ether and stearyl vinyl ether; methyl methacrylate, ethyl acrylate, and maleic. Unsaturated carboxylic acid esters such as monomethyl acid; vinylidenes such as vinylidene chloride and vinylidene bromide; vinyl cyanides such as acrylonitrile and methacrylonitrile; and aromatic vinyls such as styrene and α-methylstyrene. .

The epoxy group-containing methyl methacrylate copolymer as the component (C) is a copolymer of methyl methacrylate, an epoxy group-containing monomer and, if necessary, a second comonomer copolymerizable therewith. In some cases, the content of methyl methacrylate unit is preferably 60% by weight or more, and more preferably 70% by weight or more. When methyl methacrylate is less than 60% by weight,
Usually, there is a risk that the compatibility with the vinyl chloride resin is reduced and the mechanical strength of the molded product is reduced. Examples of the epoxy group-containing monomer copolymerized with methyl methacrylate include the same monomers as described in the description of the epoxy group-containing vinyl chloride copolymer. The second comonomer also includes the same monomers as described in the description of the epoxy group-containing vinyl chloride copolymer, except that vinyl chloride is used instead of methyl methacrylate.

The epoxy group-containing acrylonitrile-styrene copolymer as the component (C) includes acrylonitrile,
It is a copolymer of styrene, an epoxy group-containing monomer and a third monomer copolymerizable therewith. The total content of the acrylonitrile monomer unit and the styrene monomer unit is preferably at least 60% by weight, more preferably at least 75% by weight. When the total amount of the acrylonitrile monomer unit and the styrene monomer unit is 60
When the amount is less than% by weight, the mechanical strength of the molded article tends to decrease. Examples of the epoxy group-containing monomer copolymerized with acrylonitrile and styrene include the same monomers as described in the description of the epoxy group-containing vinyl chloride copolymer. Also, the second comonomer is the same monomer as described in the description of the epoxy group-containing vinyl chloride copolymer,
However, monomers obtained by replacing acrylonitrile and styrene with vinyl chloride can be used.

In the present invention, a methyl methacrylate copolymer containing 60% by weight or more of a methyl methacrylate unit is used as the component (D). The glass transition point of the copolymer is preferably from 50 to 85 ° C. The specific viscosity as an index of the molecular weight of the copolymer is 1.5 to 4.0.
It is preferred that Here, the methyl methacrylate-based copolymer as the component (D) does not contain an epoxy group. Since the glass transition point of the methyl methacrylate homopolymer is 105 ° C., in order to obtain a copolymer of the component (B) having a preferable glass transition point, the glass transition point of the methyl methacrylate comonomer should be as follows. It is preferable to select a monomer that gives a sufficiently low homopolymer. Examples of such monomers include methyl acrylate (glass transition point of homopolymer: 8 ° C.), ethyl acrylate (-22 ° C.), n-propyl acrylate (−52 ° C.), and n-butyl acrylate (− 54
° C), isobutyl acrylate (-24 ° C), n-octyl acrylate (-65 ° C), 2-ethylhexyl acrylate (-85 ° C), n-lauryl acrylate (15 ° C), n-tetradecyl acrylate ( 20 ° C), methoxyethyl acrylate (-85
Acrylates such as ethoxyethyl acrylate (-50 ° C), cyclohexyl acrylate (15 ° C) and benzyl acrylate (6 ° C); n-amyl methacrylate (10 ° C), n-octyl methacrylate (- 20 ° C), n-decyl methacrylate (-
65 ° C), n-lauryl methacrylate (-65
) And n-cetyl methacrylate (15 ° C); and diene such as butadiene and isoprene. These (meth) acrylates may be used alone or in a combination of two or more. Particularly, n-butyl acrylate is preferred.

Further, the copolymer of the component (D) may contain, as a third monomer unit, methyl methacrylate and a monomer copolymerizable with the above-mentioned monomer. Examples of such copolymerizable monomers include aromatic vinyl compounds such as styrene, vinyltoluene, and α-methylstyrene;
Unsaturated nitriles such as (meth) acrylonitrile and vinylidene cyanide; 2-hydroxyethyl fumarate,
Examples thereof include hydroxybutyl vinyl ether, monobutyl maleate, and butoxyethyl methacrylate.
The particle structure of the methyl methacrylate copolymer as the component (D) may have a substantially uniform polymer composition in the particles obtained by a one-step polymerization reaction, or may have a particle-like structure such as a so-called core-shell structure. The polymer composition may be different. When the particle structure of the methyl methacrylate copolymer (D) is a core-shell particle, the weight ratio of the core to the shell is preferably 1/1 to 15/1, The difference is preferably 50 ° C. or less. The glass transition point of the methyl methacrylate copolymer of the component (D) is preferably 50 to 85 ° C,
More preferably, the temperature is 60 to 83 ° C. When the glass transition point of the component (D) is lower than 50 ° C., the powders tend to stick to each other (blocking) during storage in a warehouse or the like in summer,
If the glass transition point of the component (D) is higher than 85 ° C., solidification after the polymerization reaction becomes difficult, and the molded product is liable to cause poor foaming. In the present invention, the measurement of the glass transition point is preferably performed by a differential thermal analyzer.

The methyl methacrylate copolymer used as the component (D) is used as an indicator of the average molecular weight of 100 ml of a chloroform solution in which 0.2 gr is dissolved.
The specific viscosity at 5 ° C. is preferably from 1.5 to 4.0, more preferably from 1.8 to 3.7. If the value of the specific viscosity is less than 1.5, the surface of the molded article tends to be rough and the expansion ratio tends not to increase. On the other hand, when the value of the specific viscosity exceeds 4.0, time is required for uniform melting. For adjusting the specific viscosity, a general method such as selection of a polymerization reaction temperature and use of a chain transfer agent such as t-dodecyl mercaptan and carbon tetrachloride can be adopted. The methyl methacrylate-based copolymer of the component (D) has an effect of uniformly dispersing wood flour in a vinyl chloride-based resin, maintaining the film strength of the foamed cell, and making it difficult to break. The amount of the component (D) in the present invention is preferably 7 to 30 parts by weight, more preferably 10 to 20 parts by weight, per 100 parts by weight of the vinyl chloride resin of the component (A). (D)
If the compounding amount of the component is less than 7 parts by weight, the holding strength of the film strength at the time of foaming becomes weak, and the foam cells are easily broken. Also,
If the amount is more than 30 parts by weight, the melt viscosity increases, the heat generation increases, and the resin tends to be thermally degraded, and the size of the foam cells tends to be uneven.

As the thermal decomposition type foaming agent which is the component (E) of the composition of the present invention, a thermal decomposition type organic foaming agent and / or a thermal decomposition type inorganic foaming agent are used. As an example of the former,
N, N'-dinitrosopentamethylenetetramine, N,
Nitroso compounds such as N'-dimethyl-N, N'-dinitrosoterephthalamide; azo compounds such as azodicarbonamide, azobisisobutyronitrile; benzenesulfonylhydrazide, p, p'-oxybis (benzenesulfonylhydrazide), And sulfonyl hydrazides such as toluenesulfonyl hydrazide. Examples of the latter include sodium bicarbonate, ammonium bicarbonate, and ammonium carbonate. In the present invention, one or more kinds selected from the group of the organic or / and inorganic pyrolytic foaming agents described above can be used.

In the present invention, butane, methyl chloride,
It is unsuitable to heat and volatilize low-boiling organic compounds such as trichlorofluoromethane, trifluoromethane and petroleum ether and use them as blowing agents. This is because the foam cells become coarse, and it becomes difficult for the molded product to be nailed or screwed, and may not be suitable for building materials. In the present invention, the compounding amount of the thermal decomposition type foaming agent of the component (E) is preferably 0.1 to 3.0 parts by weight, more preferably 0.5 to 3.0 parts by weight, per 100 parts by weight of the vinyl chloride resin of the component (A). 1.5 parts by weight. If the blending amount of the component (E) is less than 0.1 part by weight, the inside of the molded article obtained with a low expansion ratio tends to lack a woody feeling, and if it is more than 3.0 parts by weight, the molded article surface May be roughened or the surface hardness may be reduced.

The composition of the present invention contains, in addition to the above-mentioned components, heat stabilizers and plasticizers used in the processing of ordinary vinyl chloride resins, as well as lubricants, ultraviolet absorbers, impact modifiers and pigments. , A filler, an antistatic agent and the like are appropriately added.
It is preferable to add a plasticizer as a component (F) to one component of the composition of the present invention. The plasticizer is combined with the epoxy group-containing thermoplastic resin of the component (C) and the methyl methacrylate copolymer of the component (D), whereby the wood powder is uniformly dispersed even when a large amount of wood powder is blended. This is effective in further improving the fluidity of the molten resin. In the present invention, the plasticizer may be any of those conventionally used as plasticizers for processing vinyl chloride resins, and examples thereof include phthalic acid derivatives such as di- (2-ethylhexyl) phthalate, diisononyl phthalate, and dicyclohexyl phthalate; Di-n
Adipic acid derivatives such as -butyl adipate, di (2-ethylhexyl) adipate and diisononyl adipate; di- (2-ethylhexyl) azelate, di-n-
Azelaic acid derivatives such as hexyl azelate; di-n
-Sebacic acid derivatives such as -butyl sebacate and di- (2-ethylhexyl) sebacate; fumaric acid derivatives such as di-n-butyl fumarate and di- (2-ethylhexyl) fumarate; tri- (2-ethylhexyl) trimellitate and tri- Trimellitic acid derivatives such as n-octyl trimellitate, triisodecyl trimellitate and triisooctyl trimellitate; citric acid derivatives such as acetyl triethyl citrate and acetyl tri- (2-ethylhexyl) citrate; trixylenyl Phosphate derivatives such as phosphate and tris (chloroethyl) phosphate; glycol derivatives such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, and triethylene glycol dibenzoate; glycerol monoacetate Door, glycerol triacetate,
Glycerin derivatives such as glycerol tributyrate;
Epoxy derivatives such as epoxidized soybean oil, diisodecyl epoxy hexahydrohydrophthalate, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate; polyester plastics such as adipic polyester, sebacic polyester, and phthalic polyester And the like. One plasticizer may be used, or two or more plasticizers may be used in combination. The amount of the plasticizer to be added is 1 to 20 parts by weight, preferably 3 to 10 parts by weight, per 100 parts by weight of the vinyl chloride resin as the component (A).

Specific examples of the lubricant include lithium stearate, magnesium stearate, aluminum stearate, calcium stearate, strontium stearate, barium stearate, calcium laurate, barium laurate, barium 2-ethylhexoate, barium ricinoleate, Zinc stearate, zinc naphthenate, cadmium laurate, lead stearate,
Metal soaps such as dibasic lead phthalate; fatty acid esters such as n-butyl stearate, methylhydroxystearate, polyhydric alcohol fatty acid esters and ester waxes; fatty acids such as stearic acid and hydroxystearic acid; stearamide Oxystearamide, oleylamide, behenamide, methylenebisstearamide, ethylenebisstearamide, N, N '
Amide compounds such as distearyl succinamide; inorganic acid salts such as tribasic sulfate, basic lead sulfite, and dibasic lead phosphite; and polyethylene wax. In particular, the metal soap as the component (G) is added to the composition of the present invention in an amount of 0.5 to 0.5 parts by weight per 100 parts by weight of the vinyl chloride resin.
Addition of 10 parts by weight is preferable because processability is improved.
It is more preferable to add 1.5 to 7 parts by weight. In addition, addition of 0.1 to 5 parts by weight of polyethylene wax as the component (H) further improves workability,
Also, it is preferable because the mechanical strength of the molded product is increased.
More preferably, it is added in an amount of 2 to 2 parts by weight.

In order to prepare the composition of the present invention, first, (A), (B), and (E) excluding the pyrolytic foaming agent as the component (E),
The components (C) and (D) are put together in a mixer such as a Henschel mixer, and the temperature is raised to 120 to 160 ° C. while mixing, preferably by vigorous stirring. In this mixing process, water and low-boiling compounds absorbed by the wood flour are volatilized. When the above temperature is reached, the mixture is transferred to a cooling mixer and the temperature is 110-80 ° C.
When the temperature has dropped to below, the thermal decomposition type foaming agent of the component (E) is added, and the mixture is cooled while being mixed. Usually, the temperature is lowered to about 50 to 60 ° C. The removed powdery mixture can be directly used as a molding compound, but usually,
Pelletize. As a preferable method of producing pellets, a method of producing pellets using a twin-screw extruder at 150 to 170 ° C. and discharging residual moisture in wood flour from vent holes is mentioned.

In the above method for preparing the composition of the present invention,
At the time of initial mixing with a Henschel mixer or the like, all the components except for the foaming agent are added and mixed at once, whereby a mixture having a large bulk specific gravity and uniformly dispersed additives such as pigments can be obtained. The molding method for obtaining a vinyl chloride resin molded article similar to natural wood using the composition of the present invention is not particularly limited, but the above-mentioned powdery compound or pellet is usually molded by an extruder. As the conditions for the extrusion molding, the same conditions as those for the extrusion molding of a general vinyl chloride resin are employed.

Thus, the obtained extruded foamed molded article has fine cells uniformly distributed, and has a sufficiently large mechanical strength since the continuous layer of the vinyl chloride resin is adapted to wood flour. Usually, the average diameter of the cells is less than 100 μm. The expansion ratio of the extruded foamed molded product is 2.0 to
It is preferably 3.5. If the expansion ratio is too low, the woody appearance is poor. Conversely, if the expansion ratio is too high, the foam cells tend to be coarse and the mechanical strength tends to decrease. The form of the extruded product may be in accordance with the use such as a building material or a furniture material, and generally includes a plate shape, a sheet shape, a prism shape, a column shape, and a deformed shape.

Next, various embodiments of the invention of the vinyl chloride resin composition of the present invention will be described. (1) (A) 100 parts by weight of a vinyl chloride resin, (B) 20 to 150 parts by weight of wood powder having an average particle size of 50 to 500 μm,
(C) a thermoplastic resin containing an epoxy group and compatible with a vinyl chloride resin, (D) a methyl methacrylate copolymer containing 60% by weight or more of a methyl methacrylate unit, and (E) a pyrolytic foaming agent. A vinyl chloride resin composition. (2) (A) 100 parts by weight of a vinyl chloride resin, (B) 20 to 150 parts by weight of wood powder having an average particle size of 50 to 500 μm,
(C) A thermoplastic resin containing 0.3 to 10% by weight of an epoxy group and having compatibility with a vinyl chloride resin, wherein the amount of the epoxy group is based on the total amount of (A), (B) and (C). 0.
0.1 to 0.2% by weight, (D) 7 to 30 parts by weight of a methyl methacrylate copolymer containing 60% by weight or more of a methyl methacrylate unit, and (E) 0.1 to 3. A vinyl chloride resin composition containing 0 parts by weight. (3) Thermoplastic resin compatible with vinyl chloride resin
Vinyl chloride copolymer having an average degree of polymerization of 200 to 1,000 or a weight average molecular weight of 20,000 to 3,000,000
0. The vinyl chloride resin composition according to the above (1) or (2), which is a methyl methacrylate copolymer or an acrylonitrile-styrene copolymer.

(4) A methyl methacrylate-based copolymer containing 60% by weight or more of a methyl methacrylate unit is
Glass transition point of 50 to 85 ° C and specific viscosity of 1.5 to
The vinyl chloride resin composition according to any one of the above (1) to (3), which is 4.0. (5) The average degree of polymerization of the vinyl chloride resin (A) is 400 to
The vinyl chloride resin composition according to any one of the above (1) to (4), which is 1,500. (6) The vinyl chloride resin composition according to any one of (1) to (5), wherein the content of the wood powder (D) having an average particle size of 50 to 500 μm is 25 to 120 parts by weight. (7) The amount of the epoxy group is 0.02 with respect to the total amount of the components (A), (B) and (C).
The vinyl chloride resin composition according to any one of the above (1) to (6), which is an amount of up to 0.18% by weight. (8) The vinyl chloride resin composition according to any one of the above (1) to (7), wherein the methyl methacrylate copolymer (D) has a specific viscosity of 1.8 to 3.7. (9) The vinyl chloride resin composition according to any of (1) to (8) above, wherein the methyl methacrylate copolymer (D) has a glass transition point of 60 to 75 ° C. (10) In addition to the components (A), (B), (C), (D) and (E), a vinyl chloride resin (A) 1
(F) 1 to 20 parts by weight of plasticizer per 100 parts by weight, (G)
The vinyl chloride resin composition according to any one of the above (1) to (9), containing 0.5 to 10.0 parts by weight of metal soap and 0.1 to 5.0 parts by weight of (H) polyethylene wax.

[0027]

EXAMPLES The vinyl chloride resin composition of the present invention will be specifically described below with reference to Examples and Comparative Examples.
The present invention is not limited to these examples. In addition, the number of parts and% are based on weight. A methyl methacrylate copolymer was prepared by the method described in the following Production Examples. The properties of the copolymer were evaluated by the following methods.

[0028]Glass transition point Differential thermal analyzer (SEIKO SSC / 520 DSC2
20). Specific viscosity Chloroform solution 100 in which 0.2 gr of copolymer is dissolved
The specific viscosity of each ml at 25 ° C. was determined.

Solidification is performed by adding 0.05 g of carbon to 50 g of the powder obtained by coagulation, conducting a sieve analysis with a low tap for 30 minutes, and evaluating the following three grades. A: 50% by weight passing diameter is 150 to 500 μm and 1
50 mesh passing amount <1 wt% B: 50 wt% The passing diameter is 150 to 500 μm and 1
50 mesh passing amount 1 to 5% by weight C: 50% by weight Passing diameter is 150 to 500 μm and 1
50 mesh passing amount> 5% by weight

The sticking tendency inner diameter diameter 77mm coagulation powder fills the solidification powder in a cylindrical length 75mm in free fall, removed over 1 minute a load thereon, one minute to defeat containers laterally Observe whether the unity of the powder is broken within. If the powder collapses, the load is sequentially increased, and the load at which the powder is fixed without collapsing is checked, and evaluated by the following three grades. A: Does not stick even with a load of 1000 g. B: Fix with a load of 500 to 1000 g. C: Fix with a load smaller than 500 g.

Production example 1 of methyl methacrylate copolymer 150 parts of water were put into a stainless steel reactor, and after degassing, 85 parts of methyl methacrylate and 15 parts of n-butyl acrylate
Parts, 1 part of sodium alkyl sulfate having an alkyl group having 12 to 18 carbon atoms and 0.1 part of potassium persulfate were added thereto, and emulsion polymerization was carried out at a polymerization temperature of 55 ° C. with stirring. After confirming the polymerization rate of 91% by the solid content concentration, the reaction was terminated to obtain a latex. The obtained latex was added to a 1% by weight aqueous solution of aluminum sulfate at 50 ° C. with stirring, and further heated to 90 ° C. to carry out salting out, coagulation, dehydration, washing, and drying to obtain a copolymer a. . The composition of the copolymer a was 85% of methyl methacrylate units and 15% of n-butyl acrylate units, and the glass transition point was 83 ° C., the specific viscosity was 3.6, the coagulation property was A, and the fixing property was A.

The properties of the foam molded article were examined by the following methods. 1) Foam Cell State The cut surface of the molded product is observed with an optical microscope, and evaluated according to the following four grades. A: The cell is fine and uniform with a cell diameter of 100 μm or less. B: Some cells are broken and coarse. C: Many cells are broken and coarse. D: Most of the cells are broken and coarse. 2) Molded product surface properties The surface of the molded product is visually observed and touched, and evaluated according to the following four grades. A: Smooth B: Slightly shark skin C: Shark skin D: Many granular projections.

3) True specific gravity and molded product specific gravity Measured by an underwater substitution method according to JIS K 7112. 4) Molding product expansion ratio Using the specific gravity value obtained by the above measurement, the expansion ratio is determined by the following equation. Expansion ratio = true specific gravity / specific gravity of molded product 5) Tensile strength Tensile speed 10 mm with JIS K 7113 No. 1 test piece
/ Min.

Examples 1 to 5, Comparative Examples 1 and 2, Reference Examples 1 and 2
2 The components of the types and amounts shown in Table 1 were blended in a Henschel mixer in the following manner. Vinyl chloride resin, wood flour, epoxy group-containing thermoplastic resin (however, no epoxy group-containing thermoplastic resin is added in Comparative Example 2), methyl methacrylate copolymer, plasticizer, heat stabilizer, lubricant, filler and The steam was volatilized while the pigment was charged and mixed. When the temperature rose to 140 ° C., the mixture was transferred to a cooling mixer and mixed. When the temperature dropped to 100 ° C., a blowing agent was added, and the temperature was lowered to 60 ° C. The obtained powdery mixture was formed into pellets under the following conditions using a single screw extruder having a cylinder diameter of 65 mm. In addition, the water remaining in the wood powder was volatilized from the vent hole. Screw: L / D = 24, compression ratio 2.5, rotation speed 30 rpm Set temperature: C ₁ = 130 ° C., C ₂ = 140 ° C., C ₃ = 150 ° C. C ₄ = 160 ° C., head 160 ° C., die 160 ° C. Die: 3mmφ pellet × 12 holes Land length: 10mm

The pellets thus obtained were extruded and foamed by a single screw extruder having a cylinder diameter of 40 mm under the following conditions. Table 1 shows the characteristics of the molded product. Screw: L / D = 24, compression ratio 2.5, rotation speed 30 rpm Set temperature: C ₁ = 150 ° C., C ₂ = 160 ° C., C ₃ = 165 ° C. C ₄ = 170 ° C., head 160 ° C., D ₁ = 160 ° C. D ₂ = 160 ° C. Dice: thickness 3 mm width × 40 mm belt Land length: 5 mm

[0036]

[Table 1]

Note * 1 ZEST 700L, manufactured by Shin Daiichi Vinyl Co., Ltd., vinyl chloride resin, average degree of polymerization 680. * 2 Wood powder with titanium oxide particles attached, manufactured by Misawa Techno Co., Ltd.
E60-T5-3, titanium oxide content 5% by weight, average particle size 60 μm, water content 5%. * 3 Celluunt, manufactured by Shimada Shokai Co., Ltd., wood flour, average particle size 80 μm, moisture 5% by weight. * 4 Vinyl chloride-glycidyl methacrylate copolymer (copolymer weight ratio 95: 5), average degree of polymerization 750, epoxy group content 1.51% by weight. * 5 Methyl methacrylate-glycidyl methacrylate copolymer (copolymerization weight ratio 95: 5), weight average molecular weight 300,000, epoxy group content 1.51% by weight. * 6 Acrylonitrile-styrene-allyl glycidyl ether copolymer (copolymerization weight ratio 50: 45: 5), weight average molecular weight 100,000, epoxy group content 1.8.
9% by weight. * 7 Vinyl chloride-vinyl acetate-maleic anhydride copolymer (copolymerization weight ratio: 88.6: 8.5: 2.5), average polymerization degree 410, epoxy group content 0% by weight. * 8 ACPE6A, manufactured by Allied Chemical Company. * 9 Tribasic lead sulfate / lead stearate composite heat stabilizer. * 10 Calcium carbonate CCR, Shiraishi calcium
Manufactured, average particle size 0.08 μm. * 11 Carbon black (TPH0012, manufactured by Toyo Ink Mfg. Co., Ltd.) / Condensed azo red (TXH436)
0, Bisazo Yellow (TXH2110, manufactured by the company) composite pigment. * 12 The ratio (% by weight) of the epoxy group in the component (C) to the total weight of the components (A), (B) and (C).

A flat plate having a thickness of 3 mm was extrusion-molded, and compositions of various compositions were comparatively evaluated. In Examples 1 to 5 molded using the composition satisfying the requirements of the present invention, a foam molded article having a good foam cell state and surface properties, a large expansion ratio, and a high tensile strength was obtained. Further, when di-2-ethylhexyl phthalate, barium stearate and polyethylene wax were added, a molded article having more excellent expansion ratio and tensile strength was obtained (Example 5). However, in each of Comparative Examples molded using a composition that did not satisfy the requirements of the present invention, only a foam having low tensile strength was obtained. Comparative Example 1 in which a vinyl chloride-vinyl acetate-maleic anhydride copolymer having no epoxy group was blended in place of the epoxy group-containing thermoplastic resin as the component (C), and (C)
Comparative Example 2 in which no component or its substitute was blended
In Comparative Example 1, the expansion ratio of the molded product was not improved, and the tensile strength was not improved.

In Reference Example 1 in which the number of parts of the epoxy group-containing thermoplastic resin is small and the ratio of the epoxy group to the total weight of the components (A), (B) and (C) is 0.005% by weight, The expansion ratio of the molded product did not improve sufficiently. Conversely, in Reference Example 2 in which a large amount of an epoxy group-containing thermoplastic resin was blended, the tensile strength of the molded product was slightly reduced.

[0040]

EFFECT OF THE INVENTION By using the composition of the present invention, it is possible to produce a highly foamed vinyl chloride resin molded article having a uniform cell structure and a smooth surface, rich in woodiness, and suitable for building materials and furniture. can do.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 33/20 C08L 33/20

Claims (3)

[Claims] (A) 100 parts by weight of a vinyl chloride resin,
(B) 20 to 150 parts by weight of wood powder having an average particle size of 50 to 500 μm, (C) a thermoplastic resin containing an epoxy group and having compatibility with a vinyl chloride resin, and (D) 60% by weight or more of a methyl methacrylate unit. A vinyl chloride resin composition comprising a methyl methacrylate copolymer and (E) a pyrolytic foaming agent. (A) 100 parts by weight of a vinyl chloride resin,
(B) 20 to 150 parts by weight of wood powder having an average particle size of 50 to 500 μm, (C) a thermoplastic resin containing an epoxy group and having compatibility with a vinyl chloride resin, wherein the amount of the epoxy group is (A)
0.01 to 0.2 based on the total amount of (B) and (C)
(D) methyl methacrylate unit is 6
7 to 30 parts by weight of a methyl methacrylate copolymer containing 0% by weight or more and (E) a pyrolytic foaming agent of 0.1 to
A vinyl chloride resin composition containing 3.0 parts by weight. 3. A thermoplastic resin compatible with a vinyl chloride resin is a vinyl chloride copolymer having an average degree of polymerization of 200 to 1,000 or a weight average molecular weight of 20,000 to 3,000.
The vinyl chloride resin composition according to claim 1 or 2, wherein the composition is a methyl methacrylate copolymer or an acrylonitrile-styrene copolymer.