JP2002212322A - Paint-coated formed body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vegetable filler-including formed body by coating a composite material formed body that includes polyolefin resin as a resin component with high adhesion paint on the formed body surfaces, thus has resistance to weather and can be suitably used in the outdoor purpose. SOLUTION: A formed body made of a composite material of a polyolefin resin and a vegetable filler is shaved on the surfaces so that the vegetable filler may be exposed on the shaved surfaces and the surfaces are coated with a paint that can chemically bond to the vegetable filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated molded article containing a plant filler.

[0002]

2. Description of the Related Art It has been known that a composite material containing a filler and a pigment in plastics can prevent discoloration in outdoor use by applying a coating on the surface. However, among composite materials containing a plant-based filler, those using a polyolefin as a resin component have been difficult to form a coating film having good adhesion with a general paint.

[0003] In Japanese Patent Application Laid-Open No. 9-216500, a large number of scratches are formed in one direction on the surface of a wooden synthetic board made of a cellulose-based pulverized material and a thermoplastic resin, a coloring agent is applied, and the surface is further ground. It is described that a woody pattern is formed. However, even in the above-mentioned literature, there is no disclosure about a suitable coating for a composite material containing polyolefin as a resin component.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has good adhesion to the surface of a composite material molded article made of a plant-based filler containing a polyolefin-based resin as a resin component. Has the weather resistance coated with various paints,
An object of the present invention is to provide a painted molded article containing a plant-based filler having weather resistance that can be adapted to outdoor use.

[0005]

Means for Solving the Problems The present invention is characterized in that the surface of a composite material formed of a polyolefin-based resin and a plant-based filler is ground, and the above-mentioned plant-based filler is exposed on the surface of the formed body. A paint which is capable of forming a chemical bond with the plant-based filler is applied to the ground portion.

The polyolefin resins include polyethylene, polypropylene, polybutene, 4-methyl-
Examples thereof include 1-pentene, and these may be used alone or in combination of two or more. Further, it is preferable to use polypropylene in terms of mechanical strength, cost, and recyclability.

The above-mentioned plant-based fillers include timber, pulp, cellulose, paper, plywood, particle board, MDF
(Medium-density fiberboard), LVL (laminate veneer), cuttings such as bamboo, grinding chips, sawdust, crushed materials such as wood flour, grains or fruit husks such as rice husks or crushed materials thereof, jute, kenaf And the like, or a crushed product thereof, and these can be used alone or as a mixture of two or more. Among the above, wood powder is preferred because it can be easily and uniformly dispersed in the polyolefin resin.

A pigment, a light stabilizer,
An antioxidant, a discoloration inhibitor and the like may be added.

As the pigment, for example, titanium oxide,
Bengala, chromium oxide, iron black, titanium yellow, zinc-
Inorganic pigments such as iron brown, cobalt blue, titanium-cobalt green, copper-chromium black, copper-iron black, graphite, molybdate orange, navy blue carbon black, etc., azo pigments, phthalocyanines, condensed polycyclic pigments, etc. General pigments such as organic pigments.

Examples of the light stabilizers include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, ultraviolet absorbers such as cyanoacrylate-based ultraviolet absorbers, and hindered amine radical scavengers. General ones such as a radical scavenger can be used. As antioxidants, phenolic antioxidants, amine antioxidants, sulfur antioxidants,
Commonly used ones such as a phosphorus-based antioxidant are exemplified.

As the discoloration inhibitor for the above-mentioned plant-based filler,
Commonly used compounds such as semicarbazide compounds are exemplified.

The above-mentioned molded composite material may further contain a lubricant, a flame retardant, a reinforcing material, a non-vegetable filler, a foaming agent, a foaming aid, a coloring agent, an antistatic agent, an antioxidant, An antioxidant, a heat stabilizer and the like may be blended.

As a method for producing the above-mentioned composite material molded body, for example, there is a method in which a polyolefin-based resin and a plant-based filler are drive-blended, then the above-mentioned additives are blended, and the mixture is melt-kneaded and extrusion-molded. Can be

The above-mentioned melt-kneading method includes a step using a general heating and mixing device such as a mixer, a kneader, a roll, an extruder or the like equipped with a heating device.

Further, in addition to the extrusion molding, an injection molding method, a compression molding method, a calendar molding method, a stamping molding method, a transfer molding method and the like can be mentioned. By the above-mentioned molding method, for example, a sheet, a film, a pipe, a hetero-formed product,
A molded article such as a mold is obtained.

[0016] The coated molded article of the present invention is obtained by grinding the surface of the composite material molded article obtained above to expose the plant-based filler, and then forming a paint capable of chemically bonding with the plant-based filler by the grinding. It is characterized in that parts are painted. As the above-mentioned cutting treatment, for example, sanding with sandpaper or the like can be mentioned.

Examples of the paint capable of forming a chemical bond with the above-mentioned plant-based filler include those containing a resin component having an isocyanate group, an epoxy group, an amino group, a carboxyl group, a carboxylic anhydride group and the like. In particular, a reactive urethane resin having an isocyanate group is preferable in that it has high reactivity with a plant-based filler, has excellent adhesion to a composite material molded article, and has excellent weather resistance.

Further, a paint may be further applied on the coating film formed by the above paint. Examples of the overcoat paint include an acrylic paint, a fluorine paint, a silicone paint, an alkyd paint, and the like.

The greater the proportion of the plant-based filler in the above-mentioned composite material molded article, the better the adhesion of the paint film. this is,
As the ratio of the plant-based filler is larger, the ratio of the plant-based filler in the surface area of the composite material formed body is higher, and as a result,
This is because a coating film having a chemical bond selectively to the plant-based filler has a stronger and more stable adhesion.

In the above-mentioned composite material molded product, the ratio of the plant-based filler is preferably from 40 to 75% by weight. If the proportion of the plant-based filler is less than 40% by weight, the woody feeling is impaired, and if it exceeds 75% by weight, problems such as insufficient mechanical properties as a molded body occur.

[0021]

(Example 1) 100 parts by weight of polyethylene ("Novatec PE" manufactured by Nippon Polychem), 45 parts by weight
100 parts by weight of mesh wood flour and zinc stearate 5
Weight parts of the mixed material are kneaded and formed with an extruder, and 6 mm x
A plate-shaped molded body having a cross section of 60 mm was obtained. The surface of this compact was sanded with a No. 80 sandpaper to obtain a surface from which the plant-based filler was exposed. A reactive urethane paint (Dai Nippon Paint Co., Ltd., trade name “V
Top Gold ") painted.

(Comparative Example 1) A reactive urethane paint (trade name "V Top Gold" manufactured by Dainippon Paint Co., Ltd.) was applied to the surface of the molded body in the same manner as in Example 1 except that the surface of the molded body was not subjected to sanding treatment. ) Was painted.

(Comparative Example 2) A paint was applied in the same manner as in Example 1 except that an acrylic paint (manufactured by Capital Paint Co., Ltd., trade name “Wonder Water-based one-pack type”) was used instead of the reactive urethane paint.

(Comparative Example 3) 100 parts by weight of polyethylene (manufactured by Nippon Polychem Co., Ltd., trade name: Novatec PE), 45 parts by weight
100 parts by weight of mesh wood flour and zinc stearate 5
The mixture with the addition of parts by weight was melted and kneaded with an extruder to form a 6 m
A plate-shaped formed body having a cross section of mx 60 mm was obtained. The surface of the molded product was sanded with a No. 80 sandpaper. After a baking primer for polyethylene (China Paint Co., Ltd., trade name "Thermo Tac E300") is applied to the sanding surface and baked, an acrylic silicon paint (China Paint Co., Ltd., trade name "Silica Rack No. 100") is applied. ") Painted.

<Evaluation of Initial Adhesion> The coatings obtained in Example 1, Comparative Example 1 and Comparative Example 2 were subjected to a cross-cut test (based on JIS K 5400) for coating film adhesion. A coating film peeling rate of less than 10% was regarded as acceptable.

<Evaluation of Weather Resistance> The coated articles obtained in Example 1, Comparative Example 1 and Comparative Example 2 were subjected to a weather resistance acceleration test for 100 hours using a metal halide weather meter. The adhesion of the coating film after the test was observed. Table 1 shows the obtained results.

[0027]

[Table 1]

[0028]

According to the conventional plant-based composite molded product, although it has a woody feeling, the weather resistance is poor and the discoloration is remarkable. Further, even if this material is coated to improve the weather resistance, there is a problem in adhesion, and long-term weather resistance cannot be obtained. The present invention relates to a method for cutting a whole or part of a surface of a composite material formed of a polyolefin-based resin and a plant-based filler, exposing the plant-based filler to the surface of the formed body, and then exposing the plant-based filler exposed to the surface. By applying a coating which can be selectively chemically bonded to the cut portion, a composite material molded article containing a plant-based filler having excellent coating film adhesion and excellent weather resistance can be obtained.

Continued on the front page F term (reference) 4F006 AA02 AA12 AA56 AB37 BA01 BA03 4J002 AB012 AH002 BB021 BB111 BB171 FD040 FD070 FD090 4J038 DB001 DG261 GA06 GA09 KA08 NA01 NA03 PC08

Claims (4)

[Claims] 1. A surface of a composite material formed of a polyolefin resin and a plant-based filler is ground to expose the plant-based filler to the surface of the formed body, and then chemically bonded to the plant-based filler. A coated molded article, characterized in that a paint capable of performing the following is applied to the ground portion. 2. The coated molded article according to claim 1, wherein the ratio of the plant-based filler in the composite material molded article is 40 to 75% by weight. 3. The coated molded article according to claim 1, wherein the coating capable of chemically adhering to the plant-based filler is a reactive urethane resin. 4. The method according to claim 1, wherein the plant-based filler is wood flour.
4. The coated molded article according to 2 or 3.