JP2000239432A - Woodgrain finished less expandable resin composition and woodgrain patterned construction material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woodgrain finished less expandable resin composn. having smooth appearance, and a woodgrain pattern, such as irregular or parallel woodgrain, and excellent in impact resistance, and a construction material therewith. SOLUTION: This woodgrain finished less expandable resin composn. is prepared by mixing a coloring pellet comprising a thermoplastic resin contg. a coloring agent to a compsn. prepared by adding not less than 5 pts.wt. but not more than 100 pts.wt. wood powder and a thermal decompsn. type blowing agent to 100 pts.wt. styrene resin contg. not less than 10 wt.% but not more than 50 wt.% rubber component, and this construction material is prepared by coating a transparent weathering resistant resin on its surface when the compsn. is molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood-grain low-foaming resin composition and a wood-grain-forming building material, and more particularly, it has an arbitrary wood-grain pattern such as a board-grain pattern or a straight-grain pattern and has excellent impact resistance. The present invention relates to a woodgrain-like low-foaming resin composition from which a woodgrain-like molded article can be obtained, a building material having a woodgrain pattern obtained by molding the woodgrain-like low-foaming resin composition into a predetermined shape, and a woodgrain-like molded building material having excellent weather resistance.

[0002]

2. Description of the Related Art Conventionally, typical low foaming resin compositions include PVC (polyvinyl chloride) resin, polystyrene resin, and ABS (acrylonitrile-butadiene rubber-styrene copolymer). It is known to add a pyrolyzable foaming agent to a resin, a PVC / ABS blend resin, or the like, and foam it in a molding process and solidify by cooling to obtain a foam molded article.

[0003] However, foamed molded products obtained by the conventional technique have extremely poor impact resistance as compared with non-foamed molded products, and therefore, their applications are limited. Also, when trying to mold a foamed molded product having a foaming ratio of 1.5 to 2.0 times and a cross-sectional area larger than the resin flow path at the tip of the extruder, a trace of a tear is formed on the surface of the foamed molded product. And the surface appearance is poor.

[0004] Wood flour is supplied abundantly as by-products and wastes from sawmills, woodworking factories, and the like, and can generally be obtained at lower cost than other fillers. Like other fillers, by blending this wood powder with a thermoplastic resin, the effect of improving the rigidity of the molded product and reducing the specific gravity can be obtained. Various technical studies have been conducted into molded articles by extrusion molding, injection molding, calendar molding, vacuum molding, and compression molding. However, the obtained molded product is limited in the color tone and pattern of the grain pattern, does not have a smooth surface appearance, and cannot have impact resistance. In addition, there is a problem that weather resistance is extremely reduced by wood powder filling.

Accordingly, the present invention provides a woodgrain-like low-foaming resin composition having a smooth appearance, a woodgrain pattern such as a grain pattern, a straight grain pattern, and a molded article having excellent impact resistance. It is another object of the present invention to provide a building material having a wood grain pattern using the wood grain low foaming resin composition.

[0006]

In order to achieve the above object, the woodgrain-like low-foaming resin composition of the present invention is thermally decomposed with 5 to 100 parts by weight of wood flour based on 100 parts by weight of a styrene resin. And a colored pellet comprising a thermoplastic resin containing a colorant, mixed with a composition obtained by adding a mold foaming agent, and in particular, the styrene-based resin contains 10% by weight of a rubber component. % To 50% by weight, and the styrene resin is an ABS (acrylonitrile-butadiene rubber-styrene copolymer) resin, an AAS (acrylonitrile-acryl rubber-styrene copolymer) resin, AES ( Acrylonitrile-ethylene propylene rubber-styrene copolymer) It is characterized in that the scan 1 is obtained by blending 30 parts by weight or more parts.

The woodgrain pattern-forming building material of the present invention is characterized in that the woodgrain-like low-foaming resin composition is molded by profile extrusion molding. 20 microns or more made of resin 30
It is characterized in that a coating layer of 0 μm or less is provided.

[0008] The type of the styrene resin used in the present invention is not particularly limited, and can be selected according to the performance such as heat resistance. ABS resin, AES resin, AAS
It is preferable to use any of the resins or a mixture thereof.

The styrene resin preferably contains rubber components such as butadiene rubber, acrylic rubber, and ethylene-propylene rubber in the range of 10% by weight to 50% by weight, and more preferably 20% by weight to 30% by weight. % Is preferable. By including the rubber component in such a range, the surface appearance, impact resistance, and heat resistance can be improved. If the content of the rubber component is less than 10% by weight, sufficient impact resistance cannot be obtained in the foamed molded article, and if it exceeds 50% by weight, it may be too soft to be used as a building material.

The styrene resin may be a general-purpose resin, but by using a resin modified with α-methylstyrene or phenylmaleimide, the heat resistance can be improved.

[0011] The wood flour used in the present invention is not particularly limited to the type of tree, and may be pine, toga, cherry, cedar, oak, cypress,
Wood flour such as beech, lauan and fir can be used. Alternatively, a material obtained by fixing titanium oxide, talc, calcium carbonate, or the like to the surface of wood powder may be used. As the shape of the wood flour, a pulverized product is preferable, and a powder having a size of 100 mesh or less is preferable in terms of fineness of the woody texture.

The amount of the wood powder added to the styrene resin is as follows:
5 parts by weight or more per 100 parts by weight of styrene resin
The amount is suitably not more than 00 parts by weight, and preferably not less than 10 parts by weight and not more than 50 parts by weight in consideration of a feeling of woodiness and moldability. If the amount of the wood powder is less than 5 parts by weight, a good woody feeling cannot be obtained, and if it exceeds 100 parts by weight, the impact resistance is poor and a molded article having a good appearance cannot be obtained.

The type of the pyrolytic foaming agent is not particularly limited, and can be selected as necessary according to the required expansion ratio, molding method, and the like. Specifically, an organic thermal decomposition type foaming agent such as azodicarbonamide (ADCA), an inorganic thermal decomposition type foaming agent such as sodium hydrogen carbonate, and a mixture thereof can be used. It can be arbitrarily selected according to a desired expansion ratio.

Further, in order to improve the moldability of the base material, a styrene-modified polyethylene wax compatible with the styrene resin is added in an amount of 1 to 30 parts by weight based on 100 parts by weight of the styrene resin. It is preferable to mix them. If the amount is less than 1 part by weight, the surface of the foamed molded article has traces of broken bubbles, and a molded article having a smooth appearance cannot be obtained. If it exceeds 30 parts by weight, styrene-modified polyethylene wax bleeds out. And molding may not be possible. It is preferable to use a styrene-modified polyethylene wax having a molecular weight of 1,000 to 5,000.

In addition to the above, if necessary, fillers such as calcium carbonate, talc, mica, and glass beads; coloring agents such as dyes and pigments; weathering agents such as ultraviolet absorbers and light stabilizers; A reinforcing agent such as carbon fiber or glass fiber can be arbitrarily added within a range that does not impair the appearance of the molded product, the moldability, and the physical properties of the molded product.

The composition of the thermoplastic resin used in the colored pellets of the present invention is not particularly limited.
It is preferable to use any of a styrene resin, a polycarbonate resin, and an acrylic resin. In addition, each resin can be mixed at an arbitrary ratio, and in addition to the resin, if necessary, a lubricant, a filler, a weathering agent, a flame retardant, a reinforcing agent, and the like may be added to the molded product appearance, molding processability, molded product. It can be added arbitrarily as long as the properties are not impaired.

As the styrene resin used for the colored pellets, for example, commercially available resins such as SAN (styrene-acrylonitrile copolymer) resin, ABS resin, AAS resin, and AES resin can be used. And a SAN resin modified with phenylmaleimide or the like.

Further, as the polycarbonate resin,
Those using bisphenol A are preferred because of their excellent mechanical properties and transparency, and acrylic resins such as PM
MA (polymethyl methacrylate) resin and the like are preferable in terms of moldability.

The thermoplastic resin has a glass transition temperature (Tg) higher than the glass transition temperature of a styrene resin as a base material of the composition by 20 ° C. or more, and
The melt viscosity ratio at a temperature of 190 ° C. and a shear rate of 1 × 10 ² sec ⁻¹ is 1 to the styrene resin as the base material.
It is preferable to use those having a ratio of not less than / 2 and not more than 50/1.
If the temperature difference of the glass transition temperature is smaller than 20 ° C., the styrenic resin of the base material and the thermoplastic resin of the colored pellets may be mixed to make it impossible to form a pattern. If the melt viscosity ratio is less than 1/2, the colored pellets are uniformly dispersed and no pattern is formed. If the melt viscosity ratio is more than 50/1, the dispersion of the colored pellets is poor and does not clearly appear as a grain pattern. Sometimes.

If the amount of the coloring material is less than 0.5 parts by weight, the coloring material is in a state of being incorporated into the color of the styrene resin as the base material, and the grain pattern is not clear. If the amount exceeds the weight part, the color of the colored pellets may appear too much and the grain pattern may become unclear. In addition, the coloring agent mixed with the coloring pellets is not particularly limited, and various pigments and dyes can be used arbitrarily.

On the other hand, the transparent weather-resistant resin which is the main component of the coating layer may be any resin that can be thermally fused with the styrene resin as the base material. Examples thereof include acrylic resin, ABS resin, and AE resin.
S resin, AAS resin, PVC resin, PC resin, polyester resin, polyamide resin, PPE resin (including styrene-modified PPE resin), and the like, and a mixture of two or more of these can be suitably used.

The thickness of the transparent weather-resistant resin varies depending on the ultraviolet absorbing ability, but is suitably in the range of 20 to 300 microns, particularly 50 to 12 microns.
A range of 0 microns or less is preferred. If the thickness is less than 20 microns, the ultraviolet absorbing ability is insufficient. For example, in a weather resistance test using a sunshine weather meter at a black panel temperature of 63 ° C, discoloration and fading of the base material occur in 500 hours. Conversely, even if the thickness exceeds 300 microns, the effect of improving the weather resistance is hardly observed, and the contrast of the base material is weakened, so that a molded article having a good grain pattern cannot be obtained.

If necessary, the transparent weather-resistant resin may be coated with an ultraviolet absorber, a light stabilizer, a matting agent, a pigment, a dye, etc., to improve the wood grain pattern visibility, the woody feel, and the heat-fusibility with the substrate. It can be added within a range that does not impair.

The ultraviolet absorber can be appropriately selected according to the type of the resin as the main component. For example, salicylates, benzophenones, benzotriazoles, cyanoacrylates, nickel chelates and the like can be used, and hindered amines (HALS) can be used in combination. In particular, when the transparent weatherable resin is an acrylic resin filled with a matting agent, it is preferable to use a benzotriazole-based ultraviolet absorber. There is no particular limitation on the filling amount, but in the above-mentioned weather resistance test with a sunshine weather meter, in order to prevent discoloration and fading of the substrate in 500 hours, 0.5% by weight is used.
The above is preferred.

The matting agent is added as needed in order to make the surface gloss appropriate. The type and amount of the matting agent are not particularly limited. However, usually, the matting agent is compatible with the material of the transparent weather-resistant resin. May be determined according to Generally, silica particles having a particle diameter of 0.05 to 5 microns are used, and a coupling treatment can be performed depending on compatibility with the resin.

The method of coating a transparent weather-resistant resin on a molded article formed into a predetermined shape as a building material is basically performed by heat fusion. Therefore, as a coating method, a method of simultaneously performing molding of a molded article and coating of a transparent weatherable resin, such as co-extrusion molding, or a method of forming a coating layer on the surface of a molded article in advance by thermal lamination molding And so on. It is possible to obtain sufficient weather resistance even if the portion of the molded article coated with the transparent weather-resistant resin is only exposed to light or rain, but it can be appropriately selected according to the coating method (molding method). There is no problem even if the entire surface of the molded article is covered. Furthermore, at the time of molding by extrusion molding or thermal lamination molding, by transferring the embossed pattern using an embossing roll before cooling with a sizing or cooling roll, etc., to obtain a wood grain pattern molded article having an uneven pattern on the surface. Is also possible.

For example, by molding using a common co-extrusion molding machine 1 as shown in the sectional view of FIG. 1, formation of a grain pattern and coating with a weather-resistant resin can be performed simultaneously. In other words, the woodgrain-like low-foaming resin composition A is supplied to the inner supply portion 3 of the die 2 and the transparent weatherable resin B is supplied from the outer supply portion 4 and co-extruded. As shown in (1), a molded article (building material) having a two-layer structure in which a coating layer 6 made of a transparent weather-resistant resin is formed on the surface of a base material 5 made of a thermoplastic resin composition having a wood grain pattern.
Can be obtained.

The extruded molded product is cooled using a sizing 7 or a cooling roll. Before being cooled by the sizing 7, an embossed pattern is transferred using an embossing roll 8 so that an uneven pattern is formed on the surface. It is also possible to obtain a molded article having the same.

By appropriately setting the properties and mixing ratio of each resin, the properties and blending amounts of the coloring material, the extrusion speed, and the like, molded articles having various grain patterns can be obtained.

[0030]

EXAMPLES Examples of the present invention will be described below, but the scope of the present invention is not limited by the following examples.

Example 1 ABS resin 100 containing 30% by weight of butadiene rubber
25 parts by weight of wood flour (trade name: Cellulosin # 100), styrene-modified polyethylene wax (trade name: High Wax 116, manufactured by Mitsui Chemicals, Inc.)
0H) 10 parts by weight, 0.4 parts by weight of ADCA (azodicarboxylic acid amide), a pyrolytic foaming agent (manufactured by Eiwa Kasei Co., Ltd., trade name: Vinylol AC # 1), and an antioxidant (manufactured by Ciba Geigy Corporation) (Trade name: Tinuvin 329FL) was mixed with 3 parts by weight of a colored pellet with 100 parts by weight of the composition.

Using this mixture, φ using a die for forming an irregular shape having a cross-sectional area of the resin flow path at the tip of the extruder of 510 mm ² was obtained.
A low-foam molded product having a wood pattern with a cross-sectional area of 2000 mm ² is molded by a 65 mm single screw extruder, and an acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd.) by a co-extrusion molding machine.
Hypet HBS-001 (trade name) was co-extruded to obtain a low-foam molded article having a wood grain pattern having an acrylic resin coating layer having a thickness of 100 μm on the surface.

Example 2 A low-foam molded article was formed in the same manner as in Example 1 except that the butadiene rubber content of the ABS resin was changed to 10% by weight.

Example 3 A low-foam molded article was formed in the same manner as in Example 1 except that the butadiene rubber content of the ABS resin was changed to 50% by weight.

Example 4 A low-foam molded article was molded in the same manner as in Example 1 except that the amount of wood powder was changed to 10 parts by weight.

Example 5 A low-foam molded article was formed in the same manner as in Example 1 except that the amount of wood powder was changed to 100 parts by weight.

Example 6 A low-foam molded article was molded in the same manner as in Example 1 except that 1 part by weight of the styrene-modified polyethylene wax was used.

Example 7 A low-foam molded article was molded in the same manner as in Example 1 except that the styrene-modified polyethylene wax was used in an amount of 30 parts by weight.

Example 8 A low-foam molded article was formed in the same manner as in Example 1 except that the thickness of the acrylic resin coating layer on the surface was changed to 20 μm.

Example 9 A low-foam molded article was formed in the same manner as in Example 1 except that the thickness of the acrylic resin coating layer on the surface was changed to 300 μm.

Comparative Example 1 A low-foam molded article was molded in the same manner as in Example 1 except that the butadiene rubber content of the ABS resin was changed to 0% by weight.

Comparative Example 2 A low-foam molded article was formed in the same manner as in Example 1 except that the butadiene rubber content of the ABS resin was changed to 60% by weight.

Comparative Example 3 A low-foam molded article was molded in the same manner as in Example 1 except that the wood powder was used in an amount of 0 parts by weight.

Comparative Example 4 A low-foam molded article was formed in the same manner as in Example 1, except that the wood powder was used in an amount of 125 parts by weight.

Comparative Example 5 A low-foam molded article was molded in the same manner as in Example 1 except that the styrene-modified polyethylene wax was 0 parts by weight.

Comparative Example 6 A low-foam molded article was molded in the same manner as in Example 1 except that the styrene-modified polyethylene wax was used in an amount of 40 parts by weight.

Comparative Example 7 A low-foam molded article was formed in the same manner as in Example 1 except that the thickness of the acrylic resin coating layer on the surface was changed to 10 μm.

Comparative Example 8 A low-foam molded article was formed in the same manner as in Example 1 except that the thickness of the acrylic resin coating layer on the surface was changed to 500 μm.

With respect to the low-foam molded products molded in each of the examples and comparative examples, the wood grain pattern, the texture of the wood and the appearance immediately after production, and the weather resistance test using a sunshine weather meter at a black panel temperature of 63 ° C. were performed for 500 hours. The appearance (weather resistance discoloration) after the test was visually determined. In addition, according to JIS K 7111, the Charpy impact value at 23 ° C. (kg · cm / cm
² ) was measured to evaluate the impact resistance. Table 1 shows the evaluation results.

The evaluation criteria in the table are as follows.

Woody feeling ：: Similar to natural wood △: Different from natural wood ×: Similar to resin processed surface appearance ○: Smooth △: Slightly rough surface ×: Surface rough surface Impact resistance (Charpy impact value: kg · cm / cm ² ) ○: 8 or more Δ: 3 to 8 ×: 3 or less Weather resistance ○: No discoloration / discoloration Δ: Some discoloration / discoloration is observed ×: Discoloration / discoloration present

[0052]

[Table 1]

[0053]

As described above, according to the present invention,
A molded article having a wood grain pattern such as a board grain pattern and a straight grain pattern, having a good appearance and excellent impact resistance can be obtained. Further, by coating the transparent weather-resistant resin, the weather resistance can be greatly improved while maintaining the grain pattern, and a molded article suitable as a building material for interior and exterior can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a state in which a wood grain pattern molded product of the present invention is molded using a co-extrusion molding machine.

FIG. 2 is a cross-sectional view of a wood grain pattern molded product.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Co-extrusion molding machine, 2 ... Die, 3 ... Inside supply part, 4 ...
Outside supply part, 5: substrate composed of a wood-grain pattern-forming thermoplastic resin composition, 6: coating layer made of a transparent weather-resistant resin, 7: sizing, 8: embossing roll, A: wood-grain pattern-forming thermoplastic resin composition, B: Transparent weather resistant resin

Continued on front page F-term (reference) 4F074 AA02 AA12 AA13 AA17 AA24 AA32 AA49 BA03 BA13 CC22X CC23Y CE01 CE98 DA02 DA37 DA50 4F207 AA01 AA13 AA21 AA45 AA49 AA50 AB02 AB12 AC01 AF08 AG03 AG20 AH46 KA17 KA01 KA17 KB

Claims (5)

[Claims] 1. A composition obtained by adding 5 to 100 parts by weight of wood flour to 100 parts by weight of a styrene resin and a pyrolytic foaming agent, and comprising a thermoplastic resin containing a colorant. A woodgrain-like low-foaming resin composition characterized by mixing colored pellets. 2. The styrenic resin has a rubber component of 10%.
The woodgrain-like low-foaming resin composition according to claim 1, which is contained in an amount of from 50% by weight to 50% by weight. 3. The styrene-based resin is 100% by weight of at least one of acrylonitrile-butadiene rubber-styrene copolymer resin, acrylonitrile-acryl rubber-styrene copolymer resin, and acrylonitrile-ethylene propylene rubber-styrene copolymer resin. The woodgrain-like low-foam resin composition according to claim 1 or 2, wherein 1 part by weight or more and 30 parts by weight or less of styrene-modified polyethylene wax are blended with respect to 1 part by weight. 4. A woodgrain-forming building material obtained by molding the woodgrain-like low-foaming resin composition according to claim 1, 2 or 3 by profile extrusion. 5. When the woodgrain-like low-foaming resin composition according to claim 1, 2 or 3, is subjected to profile extrusion molding, a coating layer of 20 μm or more and 300 μm or less made of a transparent weatherable resin is provided on the surface thereof. A wood grain pattern molded product characterized by that.