JPH09239707A - Vinyl choride resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded product rich in wooden feeling and suitable for a building material such as a window frame or a furniture material by using a composition constituted by compounding a vinyl chloride resin with a predetermined average polymerization degree, a methacrylic ester resin, a thermally decomposable foaming agent and charcoal with a predetermined average particle size having small hard particles bonded to the surface thereof. SOLUTION: A vinyl chloride type resin compsn. is formed by compounding a vinyl chloride resin A with an average polymerization degree of 400-1500, a methacrylic ester resin B wherein methyl methacrylate content is above 88wt.%, a thermally decomposable foaming agent C and charcoal D with an average particle size of 50-500μm having small hard particles bonded to the surface thereof and prepared by collectively heating the components A, B, D at first while violently stirring and mixing them to volatilize moisture of charcoal during this mixing process and transferring the resulting mixture to a cooling mixer after the mixture reaches predetermined temp. and adding the component C thereto to lower the temp. of the mixture. The taken-out powdery mixture can be used as a molding compound as it is.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition containing wood flour, and more particularly to a building material and a furniture material having a uniform and fine foamed cell structure and a smooth skin, and being rich in a wooden texture. The present invention relates to a vinyl chloride-based resin composition capable of providing a molded article suitable for a resin.

[0002]

2. Description of the Related Art Wood can be repeatedly produced by photosynthesis, and is therefore 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, we developed a vinyl chloride resin composition that is often used in construction materials by blending wood powder with vinyl chloride resin, which is a general-purpose resin that has high mechanical strength and is easy to mold and process. If possible, a harmonious way to use the earth's resources will be greatly opened up. 2. Description of the Related Art Conventionally, it is often practiced to mix wood powder with a vinyl chloride resin to form a wood-like appearance and tactile sensation. However, since a considerable amount of wood flour must be blended, there is a problem that mechanical strength such as tensile strength is greatly reduced, and a natural wood texture cannot be realized yet. In order to improve the clarity of wood grain and the ease of processing, a vinyl chloride resin composition in which a urea resin is added in addition to wood powder has been proposed (JP-A-60-42007, JP-A-60-2007). -73807, JP-A-60-73808). Further, a vinyl chloride resin composition obtained by adding polyethylene, an ethylene-vinyl acetate copolymer, or an ABS resin to an inorganic filler such as mica in addition to wood powder has a small linear expansion coefficient, impact resistance and moldability. It has been disclosed that it is excellent (JP-A-60-192).
746 and 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. Dispersion and homogenization were significantly improved by blending wood powder to which inorganic powder or plastic powder was adhered during plastic processing (Japanese Patent Laid-Open Nos. 5-177610 and 5-26170).
No. 8), resin moldings rich in wood texture have not yet been obtained.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention provides a window having a uniform and fine foam cell structure and a smooth skin, and having a low mechanical strength, a rich woody feeling, and a window. An object of the present invention is to provide a vinyl chloride resin composition capable of providing a molded product suitable for building materials such as frames and furniture materials.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted a specific treatment on a vinyl chloride resin in the presence of a methacrylic acid ester resin which is a processing aid. It was found that the above object can be achieved by compounding and foam-forming, and based on this finding, the present invention has been completed. That is, the present invention provides (1) (A) a vinyl chloride resin having an average degree of polymerization of 400 to 1500, and (B) a methyl methacrylate content of 88% by weight.
A vinyl chloride resin composition obtained by blending more methacrylic acid ester resin, (C) thermal decomposition type foaming agent, and (D) wood powder having an average particle diameter of 50 to 500 μm with hard small particles attached to the surface thereof, And (2) (A) 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 400 to 1500, and (B) a methacrylic acid ester resin having a methyl methacrylate content of more than 88% by weight.
30 parts by weight, (C) 0.1 to 3.0 parts by weight of a pyrolytic foaming agent, and (D) an average particle size of 5 with hard small particles attached to the surface.
The present invention provides a vinyl chloride resin composition containing 5 to 100 parts by weight of wood powder of 0 to 500 μm.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The vinyl chloride-based resin used as the component (A) in the composition of the present invention includes, in addition to a homopolymer of vinyl chloride, a copolymer containing 50% by weight or more of vinyl chloride as a main component. In the case of a vinyl chloride copolymer, examples of the comonomer include olefins such as ethylene and propylene; halogenated olefins such as allyl chloride, vinylidene chloride, vinyl fluoride and ethylene trifluoride chloride; vinyl acetate, Carboxylic acid vinyl esters such as vinyl propionate; Vinyl ethers such as isobutyl vinyl ether and cetyl vinyl ether; Allyl-3-
Allyl ethers such as chloro-2-oxypropyl ether and allyl glycidyl ether; acrylic acid, maleic acid, itaconic acid, 2-hydroxyethyl acrylate, methyl methacrylate, monomethyl maleate, diethyl maleate, maleic anhydride, etc. Unsaturated carboxylic acids, their esters or their acid anhydrides; unsaturated nitriles such as acrylonitrile and methacrylonitrile; acrylamide, N-methylolacrylamide, acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropyltrimethylammonium Examples thereof include acrylamides such as chlorides; allylamine benzoate, allylamines such as diallyldimethylammonium chloride, and derivatives thereof. The monomers exemplified above are only a part of the copolymerizable monomers, and are exemplified in “Polyvinyl Chloride” edited by Kinki Chemical Association Vinyl Subcommittee, Nikkan Kogyo Shimbun (1988), pp. 75-104. Various monomers can be used. Ethylene-
Resin such as vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, and chlorinated polyethylene is grafted with vinyl chloride or vinyl chloride and the above-mentioned copolymerizable monomer. Also included are resins that have been polymerized. 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 degree of polymerization is 40 according to the measurement method specified in JIS K 6721.
Those in the range of 0 to 1500, preferably 600 to 1100 can be suitably 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, while if it is more than 1,500, a large amount of coarse particles may be mixed in the foam cells.

In the present invention, as the methacrylic acid ester resin having a methyl methacrylate content of more than 88% by weight, which is used as the component (B), a homopolymer of methyl methacrylate and a monomer copolymerizable therewith can be used. , That is,
A copolymer with one or more monomers such as ethyl acrylate, butyl acrylate, ethoxyethyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxypropyl methacrylate, acrylonitrile, and vinyl acetate. Therefore, those containing more than 88% by weight, preferably 90% by weight or more of methyl methacrylate are used. When the methyl methacrylate content is 88% by weight or less, it is difficult to increase the expansion ratio. The particle structure of the methacrylic acid ester-based resin as the component (B) may be a polymer composition in which the inside of the particles is substantially uniform, or the methacrylic acid ester-based polymer disclosed in Japanese Patent Publication No. 5-38014, that is, , Two-stage resin particles such as a resin in which the inside of the particle is a copolymer of methyl methacrylate and an acrylic ester and the outside is covered with a polymer of methyl methacrylate alone or a copolymer mainly containing methyl methacrylate May be The methacrylic acid ester resin used as the component (B) has a specific viscosity of 0.10 to 3.5 at 25 ° C. in 100 ml of a chloroform solution in which 0.2 gr is dissolved.
It is preferably 0, and 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 product tends to be rough, and 1.0
If it exceeds 0, it may take time for uniform melting.

The methacrylic acid ester-based resin as the component (B) has an effect of improving the melt viscosity characteristic of the vinyl chloride-based resin, maintaining the film strength of the foamed cell and making it difficult to break.
The blending amount of the component (B) in the present invention is preferably 0.5 to 30 parts by weight, and more preferably 1 to 20 parts by weight, per 100 parts by weight of the vinyl chloride resin of the component (A).
If the blending amount is less than 0.5 part by weight, the retention of the film strength during foaming becomes weak and the foam cells are easily broken. On the other hand, if the blending amount exceeds 30 parts by weight, the melt viscosity becomes high, the heat generation becomes large, and the heat deterioration of the resin is apt to occur, or the size of the foamed cells tends to become uneven.

As the thermal decomposition type foaming agent which is the component (C) of the composition of the present invention, a thermal decomposition type organic foaming agent and / or a thermal decomposition type inorganic foaming agent is used. Examples of the former are N,
N'-dinitrosopentamethylenetetramine, N, N '
-Nitroso compounds such as -dimethyl-N, N'-dinitrosoterephthalamide; azo compounds such as azodicarbonamide, azobisisobutyronitrile, benzenesulfonylhydrazide, p, p'-oxybis (benzenesulfonylhydrazide), and toluenesulfonylhydrazide And the like. Examples of the latter include sodium bicarbonate, ammonium bicarbonate, ammonium carbonate and the like. 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, it is inappropriate to heat and volatilize low-boiling organic compounds such as trifluoromethane and petroleum ether for use as a blowing agent. 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 (C) is 100 parts of the vinyl chloride resin of the component (A).
It is preferably 0.1 to 3.0 parts by weight, more preferably 0.5 to 1.5 parts by weight per part 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, and if it is more than 3.0 parts by weight, the molded article surface will be poor. Tends to be rough and the surface hardness tends to decrease.

In the present invention, as the component (D), an average particle size of 50 to 500 μm in which hard small particles are attached to the surface
Wood flour is used. Hard small particles are particles having a hardness larger than that of wood powder and an average particle size smaller than that of wood powder, and specifically include metals, metal oxides and salts, inorganic compounds and plastic particles. Can be mentioned. Preferred component (D) is titanium oxide, nickel, calcium carbonate,
Inorganic or metallic particles such as silica and mica. Wood flour with hard small particles attached to the surface used in the present invention,
JP-A-5-177610 and JP-A-5-2617
No. 08 publication. The mode in which the hard small particles adhere to the wood flour surface is hard, such as an entanglement bond including biting of the hard small particles into the wood flour, a narrowing bond between a plurality of bite-bonded hard small particles, and the like. 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 tree species of wood powder is not particularly limited, and lumber pieces of coniferous trees such as cedar, hemlock, and lauan, hardwood timber pieces, wood chips, sawdust, and the like can be used. To obtain the component (D) of the present invention from these woods,
For example, the wood is processed into a relatively roundish wood powder having an average particle size of 500 μm or less by a crusher, and then charged into a ball mill or the like together with hard small particles, and treated under a nitrogen atmosphere to prevent dust explosion. The amount of hard small particles adhered is 1 to 50% by weight, preferably 5 to 50% by weight of the wood powder after the adhesion treatment.
30% by weight. If the amount of hard small particles is less than 1% by weight, the wood powders tend to be fibrous and aggregate, and conversely, if it is more than 50% by weight, the texture of wood may be deteriorated. The average particle size of the component (D) used in the present invention is 50 to 500 μm, preferably 30 to 100 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. (D) The average particle size of the component is 50μ.
If it is less than m, the bulk specific gravity becomes small and the mixing operability for preparing the composition becomes poor, and if it is more than 500 μm, the molded article surface becomes rough and the foaming ratio decreases. The water content of the component (D) is preferably 10% by weight or less, more preferably 5% by weight or less. In the composition of the present invention,
In addition to the above components, in addition to heat stabilizers and lubricants used during the processing of ordinary vinyl chloride resin, ultraviolet absorbers,
An impact resistance enhancer, a pigment, a plasticizer, an antistatic agent and the like are appropriately added.

To prepare the composition of the present invention, first, (C)
(A), (B) and (D) excluding the thermal decomposition type foaming agent of the component
The ingredients and the like are put together into a mixer such as a Henschel mixer, and the temperature is raised to 120 to 160 ° C. with vigorous stirring and mixing. In this mixing process, the moisture absorbed in the wood flour is volatilized. When the above temperature is reached, the mixture is transferred to a cooling mixer, and the temperature is reduced to 50 to 60 ° C. after adding the pyrolytic foaming agent of the component (C). The removed powdery mixture can be used as a molding compound as it is, but is usually then pelletized. As a preferable method for producing pellets, a twin-screw extruder is used, and 150 to 1
A method of producing pellets at 70 ° C. and discharging the residual water content in the wood flour from the vent hole can be mentioned. In the above method for preparing the composition of the present invention, the bulk components are large and the additives such as pigments are uniformly dispersed by adding and mixing all components except the foaming agent at the time of initial mixing with a Henschel mixer or the like. A mixture 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 an extrusion molding method is usually adopted.

The aspects of the present invention will be described below. (1) (A) Vinyl chloride resin having an average degree of polymerization of 400 to 1500, (B) Methyl methacrylate content of 88% by weight
A vinyl chloride resin composition comprising a larger amount of a methacrylic acid ester resin, (C) a thermal decomposition type foaming agent, and (D) wood powder having an average particle diameter of 50 to 500 μm in which hard small particles are attached to the surface. (2) The average degree of polymerization of the vinyl chloride resin is 600 to 110.
The vinyl chloride resin composition according to the above (1), wherein 0 is 0. (3) Methacrylic acid ester resin having a methyl methacrylate content of more than 88% by weight has a specific viscosity of 0.10 to 3.50 at 25 ° C. in 100 ml of a chloroform solution in which 0.2 gr is dissolved. ) Or (2) the vinyl chloride resin composition. (4) The specific viscosity of the methacrylate ester resin having a methyl methacrylate content of more than 88% by weight is 0.30 to 3.00 at 25 ° C. in 100 ml of a chloroform solution in which 0.2 gr is dissolved. ) Or (2) the vinyl chloride resin composition. (5) The vinyl chloride resin composition according to any one of (1) to (4), wherein the hard small particles are at least one selected from the group consisting of metals, metal oxides and salts, inorganic compounds, and plastic particles. Stuff. (6) The vinyl chloride resin composition according to any one of (1) to (5) above, wherein the amount of hard small particles attached to wood powder is 1 to 50% by weight. (7) The vinyl chloride resin composition according to any one of the above (1) to (6), wherein the average particle diameter of the wood powder having hard small particles attached to the surface is 30 to 100 μm.

(8) (A) Average degree of polymerization 400 to 1500
100 parts by weight of vinyl chloride resin, (B) 5 to 30 parts by weight of methacrylic acid ester resin having a methyl methacrylate content of more than 88% by weight, and (C) thermal decomposition type foaming agent 0.1.
˜3.0 parts by weight and (D) 5 to 100 parts by weight of wood powder having an average particle size of 50 to 500 μm with hard small particles attached to the surface thereof are blended. (9) The average degree of polymerization of the vinyl chloride resin is 600 to 110.
The vinyl chloride resin composition according to the above (8), which is 0. (10) The methacrylic acid ester-based resin having a methyl methacrylate content of more than 88% by weight has a specific viscosity at 25 ° C. of 100 ml of a chloroform solution in which 0.2 gr is dissolved is 0.10 to 3.50. ) Or (9)
Vinyl chloride resin composition. (11) The methacrylic acid ester-based resin having a methyl methacrylate content of more than 88% by weight has a specific viscosity at 25 ° C. of 100 ml of a chloroform solution in which 0.2 gr is dissolved is 0.30 to 3.00. ) Or (9)
Vinyl chloride resin composition. (12) The vinyl chloride resin composition according to any one of (8) to (11), wherein the hard small particles are at least one selected from the group consisting of metals, metal oxides and salts, inorganic compounds, and plastic particles. Stuff. (13) The amount of hard small particles attached to wood powder is 1 to 50% by weight.
The vinyl chloride resin composition according to any one of (8) to (12) above. (14) The vinyl chloride resin composition according to any one of the above (8) to (13), wherein the average particle size of the wood powder having hard small particles attached to the surface is 30 to 100 μm.

[0013]

EXAMPLES 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 foamed molded product 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 rank. A: The cell diameter is 100 μm or less and is in a fine and uniform state. B: Some cells are broken and coarse. C: Many cells are broken and coarse. D: Most of the cells are broken and coarse. 2) Surface property of molded product The surface of the molded product is visually and touched and evaluated by the following ranks. A: Smooth B: Some shark skin C: Shark skin D: Many granular protrusions. 3) True specific gravity and molded product specific gravity Measured by the 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 of 10 mm with JIS K 7113 No. 1 test piece
/ Min.

A wood flour sample having hard particles attached to its surface was obtained as follows. 1) Titanium oxide-coated wood powder A commercially available E60-T5-3 manufactured by Misawa Techno Co., Ltd. was used. Titanium oxide content 5% by weight, average particle size 60 μm,
Water content 5% (referred to as surface-treated wood flour 1). 2) Calcium carbonate coated wood powder 100 parts by weight of wood powder (trade name Selyunt) with an average particle size of 80 μm sold by Shimada Shokai Co., Ltd. and calcium carbonate with an average particle size of 3.6 μm manufactured by Shiraishi Industry Co., Ltd. (trade name) 20 parts by weight of Whiten B) was charged into a ball mill (Attritor A200, manufactured by Mitsui Miike Kakoki Co., Ltd.) using ceramic balls and operated for 3 hours. The adhesion amount of calcium carbonate of the obtained sample was measured by a combustion method and found to be 6.2% by weight. The average particle size was 55 μm and the water content was 5% (referred to as surface-treated wood flour 2). Further, using a wood powder having an average particle size of 700 μm obtained from a synthetic wood board maker, a calcium carbonate-coated wood powder was obtained in the same manner as above. The amount of calcium carbonate deposited was 8.0% by weight, the average particle size was 600 μm, and the water content was 5% (referred to as surface-treated wood flour 3).

Examples 1 and 2, Comparative Examples 1 to 5 Components of the types and amounts shown in Table 1 were blended in the following manner using a Henschel mixer. Water vapor was volatilized while charging and mixing a vinyl chloride resin, a methacrylate resin (except for Comparative Example 1), wood flour, a heat stabilizer, a lubricant, a filler, and a pigment. When the temperature rose to 140 ° C., the mixture was transferred to a cooling mixer and mixed, and after the temperature dropped to 60 ° C., the blowing agent was added. The obtained powdery mixture was formed into pellets under the following conditions using a single screw extruder having a cylinder diameter of 65 mm. 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 Setting temperature: C ₁ = 130 ° C., C ₂ = 140 ° C., C ₃ = 150 ° C. C ₄ = 160 ° C., head 160 ° C., die 160 ° C. Die: 3 mmφ pellet × 12 holes Land length: 10 mm The pellet thus obtained was extrusion foamed under the following conditions by a uniaxial extruder having a cylinder diameter of 40 mm. Table 1 shows the characteristics of the molded product. Screw: L / D = 22, compression ratio 2.5, rotation speed 25 rpm Set temperature: C ₁ = 140 ° C., C ₂ = 160 ° C., C ₃ = 170 ° C. C ₄ = 180 ° C., head 160 ° C., D ₁ = 160 ° C D ₂ = 160 ° C Die: Thickness 4 mm Width x 50 mm Belt land length: 5 mm

[0016]

[Table 1]

Note * 1 Zest 103 EP7, manufactured by Shin-Daiichi Polyvinyl chloride Co., Ltd., vinyl chloride resin, average degree of polymerization 680 * 2 Hybrene B403, manufactured by Nippon Zeon Co., Ltd., a copolymer having a methyl methacrylate content of about 91% by weight. Specific viscosity (measured at 25 ° C. by taking a sample from 100 ml of a chloroform solution having 0.2 g dissolved therein) 2.00 * 3 Selyunt, manufactured by Shimada Shokai Co., Ltd., wood powder, average particle size 80 μm, water content 5% by weight * 4 Tribasic lead sulfate / lead stearate composite heat stabilizer * 5 Polyethylene wax * 6 Calcium carbonate CCR, Shiraishi Calcium Co., Ltd.
Made, average particle size 0.02 μm * 7 carbon black (TPH0012, manufactured by Toyo Ink Mfg. Co., Ltd.) / Condensed azo red (TXH4360,
Company pigment) / Bisazo Yellow (TXH2110, Company) composite pigment

In Examples 1 and 2 molded using the composition satisfying the requirements of the present invention, a molded product having a good foam cell state and surface properties, having a sufficient expansion ratio, and satisfying the tensile strength. was gotten. In Comparative Example 1 in which the methacrylic acid ester-based resin was not blended, the foam cell state, the surface properties, and the expansion ratio were all poor. Comparative Example 2 using a non-pyrolysis type foaming agent gave a molded product having a large expansion ratio but insufficient cell state and surface properties. Further, as a matter of course, when the foaming agent is not blended, the molded product has no cells and therefore has no wood texture (Comparative Example 3). When the wood powder does not have hard small particles, a molded product having insufficient foam cell state, surface properties and expansion ratio is obtained (Comparative Example 4). Wood powder having a coarse diameter results in a molded product in which the state of foam cells and the surface properties are remarkably rough (Comparative Example 5).

[0019]

EFFECTS OF THE INVENTION By using the composition of the present invention, a molded product having a uniform and fine foam cell structure and a smooth skin and having a rich wooden texture and suitable for building materials and furniture materials can be obtained.

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Claims (2)

[Claims] 1. A vinyl chloride resin having an average degree of polymerization of 400 to 1500 and (B) having a methyl methacrylate content of 8.
More than 8% by weight of methacrylic acid ester resin, (C)
A vinyl chloride resin composition comprising a pyrolyzable foaming agent and (D) wood powder having an average particle size of 50 to 500 μm in which hard small particles are attached to the surface. 2. (A) 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 400 to 1500, (B) 5 to 30 parts by weight of a methacrylic acid ester resin having a methyl methacrylate content of more than 88% by weight, (C). ) Pyrolysis type foaming agent 0.1
A vinyl chloride resin composition comprising 3.0 parts by weight and (D) 5 to 100 parts by weight of wood powder having an average particle size of 50 to 500 μm, in which hard small particles are attached to the surface. [0001]