JP2017124506A - Woody resin molding material and method for producing woody resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new improved woody resin molding material which does not adopt means such as printing on a surface part, coating and sheet wrapping, further facilitates adjustment of a color tone compared to a conventional one, and can reduce a cost with a simple production step, and to provide a method for producing a woody resin molding.SOLUTION: A woody resin molding material contains (A) a mixed pellet of a bleached woody fiber or woody flour and a thermoplastic resin, and (B) a mixed pellet of a woody fiber or woody flour that is not bleached and a thermoplastic resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a woody resin molded article and a method for producing the same.

  Conventionally, an attempt has been made to make a resin molded product into a wood-like shape for various building materials. For example, it is also well known to impart a woody grain pattern to a resin molded product. One example is to perform ink jet printing, painting, or sheet wrapping on the surface of the resin molded product in order to obtain a wood grain appearance.

  It is also well known to mix a resin material with a pigment or a colorant to adjust the color tone or pattern, or to knead and mold a plurality of different color tone pellets. On the other hand, in order to modify the color tone and display patterns in resin molded products, it has also been attempted to knead and mold resinous wood materials such as wood fibers and wood powder together with pigments and colorants. Yes.

  For example, in order to make decorative fiberboards with a variety of woody patterns, it has been proposed to mix colored pieces formed from waste powders of decorative fiberboard and fiber materials and bond them with resin binders. (Patent Document 1).

  And about the fiber material mixed with a resin material, the pulp paper material from a used paper raw material is used with a coloring agent (patent document 2), and bleached wood powder and a cellulose powder are mixed and molded with a white pigment ( Patent document 3) has also been attempted.

JP-A-63-55171 Japanese Patent No. 3499555 JP 59-133255 A

  In the conventional technology for providing a wood grain pattern as described above, it takes time in the production process in the case of printing or painting on the surface of a resin molded product, sheet wrapping, etc., producing costs, and stable quality. There was a problem in terms of maintenance. In addition, in the mixing of pigments and colorants into resin materials, it is not always easy to adjust the color tone to make woody, especially wood grain, and the cost increases due to the material costs of pigments and colorants. There was also a problem.

  As for pigments and colorants, attempts have been made as described in Patent Documents 1 to 3 to mix fiber materials whose types and characteristics are specified. However, the above-described problems have not been solved in order to obtain a wood-like, particularly wood-grained resin molded product.

  The present invention has been made in view of the circumstances as described above, and does not employ means such as printing on the surface, painting, and sheet wrapping, and color adjustment is easier than in the past. In addition, it is an object of the present invention to provide an improved new wood resin molding material and a method for producing a wood resin molded product, which can reduce costs by a simple production process.

In order to solve the above problems, the present invention
(A) Kneaded pellets of bleached wood fiber or wood powder and thermoplastic resin, and (B) Kneaded pellets of unbleached wood fiber or wood powder and thermoplastic resin,
A woody resin molding material containing
It is characterized by being.

  According to the present invention, without adopting means such as printing on the surface of the resin molded product, painting, sheet wrapping, etc., and color tone adjustment is easier than before, and in a simple production process, Cost reduction is also possible.

It is the photograph replaced with drawing which showed the Example of the wood resin molded product which has a wood-like grain pattern.

As mentioned above, the woody resin molding material of the present invention is
(A) Kneaded pellets of bleached wood fiber or wood powder and thermoplastic resin, and (B) Kneaded pellets of unbleached wood fiber or wood powder and thermoplastic resin,
It is characterized by containing.

  Here, “woody fiber or wood flour” used in any of bleached wood fiber or wood powder and unbleached wood fiber or wood flour is a fiber or powder derived from “wood material”, It is a granular material. “Wood material” includes various types of plant materials such as wood, bamboo, hemp, vegetation, agricultural products, wastes and residues of these plant materials (eg, skin, leaves, stems, fruits, etc.), A wide range of papers, pulps, recovered and regenerated products obtained by processing these are included.

  Examples of the wood include conifers such as cedar, hinoki and pine, and broad-leaved trees such as beech, oak and hippopotamus. Examples of hemp include jute, kenaf, flax, hemp, ramie, sisal and the like. Plant materials other than these include, for example, rice straw, rice husk, straw, coconut and sugar cane squeezed residue.

  The “woody fiber or wood flour” in the present invention is subjected to various treatments such as cutting, splitting, defibration, shredding, dispersion, pulverization, granulation, etc. on the above wood material itself or wood material. It is considered to have been given.

  The (A) bleached wood fiber or wood powder is characterized by being “bleached”. In addition, (B) unbleached wood fiber or wood flour is characterized by “not bleached”. Here, “bleaching” is considered to be caused by various means of bleaching and decoloring applied to ordinary woody materials, plant materials and the like. For example, representative means include oxygen bleaching using hydrogen peroxide, oxygen, ozone, etc., and bleaching using an enzyme. As a simple one, it is considered that a bleaching reaction with a hydrogen peroxide solution having a concentration of 10 to 40% is performed.

  The meaning of “bleached” is usually based on the ISO whiteness measuring method and standard of JIS P 8148 (2001). In the present invention, in this ISO whiteness, at least 50%, more preferably 70% or more is considered based on the original color of the wood material.

  (A) Kneaded pellets of bleached wood fiber or wood powder and thermoplastic resin, and (B) Thermoplastic resin used for kneaded pellets of unbleached wood fiber or wood powder and thermoplastic resin Examples thereof include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, acrylic resin, PMMA, and ABS resin. These thermoplastic resins are not limited to those of virgin, and may be waste plastic or recycled plastic after use.

  In addition, these thermoplastic resins may be used as a single type, or may be a plurality of different types in consideration of the use, characteristics, color pattern, etc. of the wood resin molded product of the present invention. Also good.

  The wood fiber or wood powder in the above (A) and (B) is mixed by selection of the type, and the appropriate adjustment of the content weight and specific gravity in the resin molded product, and physical properties such as strength and thermal expansion coefficient, Setting is possible. In addition, depending on the presence or absence of “bleaching” in (A) and (B) above, (A) and (B) adjusting the pattern form and color tone as a wood-like wood grain pattern by selecting various types and mixing ratios of both. Setting is easy. The type and mixing ratio in the (B) unbleached wood fiber or wood flour are one of the factors that determine the color pattern. This (B) unbleached wood fiber or wood powder, unlike the case of conventional pigments and colorants, has a simple production process and is unlikely to increase the cost of a resin molded product. Moreover, because of the commonality as derived from the wood material, it has an affinity for (A) bleached wood fiber or wood powder, and in mixing of the kneaded pellets of (A) and the kneaded pellets of (B) It facilitates the formation of a grain pattern by dispersion. By mixing the two pellets, a random grain pattern is formed, which is essentially different from conventional printing, painting, and sheet wrapping, and a molded article having a high real feeling can be obtained. In addition, mixing of the kneaded pellets of (A) and the kneaded pellets of (B) is not performed so as to be completely uniform, but mixed so as to have a certain degree of density unevenness. As a result, color unevenness is generated in the molten resin, and the material stretched by the flow of the resin is stretched into a wood pattern to form a woody wood grain pattern.

  In the wood fiber or wood powder that has been bleached (A), it may be appropriately set according to the color tone and pattern, but in general, the wood fiber has a fiber length of 5 mm or less and a fiber diameter of 1 mm or less. For wood flour, those of 50 mesh or less are preferably considered. In addition, as (A) bleached wood fiber or wood powder, paper and pulp as well as waste paper as waste materials thereof can be used. Moreover, the unbleached wood fiber or wood powder containing these may be previously colored by the predetermined color.

  Regarding the blending ratio of (A) bleached wood fiber or wood powder and thermoplastic resin kneaded pellets and (B) unbleached wood fiber or wood powder and thermoplastic resin kneaded pellets, the former That is, it is desirable that the proportion of the kneaded pellets of (A) bleached wood fiber or wood powder and thermoplastic resin occupy half or more by mass ratio. More specifically, it is preferably considered that the mass ratio is in the range of 51 to 95.

  Moreover, as a ratio of the wood fiber or the wood flour in the total amount of these (A) and (B), it is generally considered that it is in the range of 40 to 90% by mass, preferably 60 to 80% by mass.

  As for the woody resin molded product of the present invention as described above, (A) kneaded pellets of bleached wood fiber or wood powder and thermoplastic resin, (B) unbleached wood fiber or wood powder and heat. It can be produced by mixing, kneading and molding kneaded pellets with a plastic resin. Various means such as extrusion molding, injection molding, and press molding can be applied as means and methods for molding.

  By mixing, kneading and forming the pellets as described above, the dispersion of the unbleached wood fiber or wood powder for forming the color tone and pattern becomes appropriate, and the wood resin of the present invention It becomes easier to adjust the color tone of the molded product and to form a pattern.

  For molding with such mixing and kneading of pellets, the blending ratio, means and method of extrusion molding are considered as suitable. For extrusion molding, for example, the conditions of extrusion pressure such as operating temperature and screw rotation speed are appropriate from the viewpoint of the type and blending ratio of wood fiber or wood flour, the type and blending of thermoplastic resin, and the required color tone and pattern. It is set as appropriate.

  Hereinafter, examples will be shown and described in more detail. Of course, the present invention is not limited to this example.

  70 parts by weight of wood powder and 30 parts by weight of polypropylene (MFR30) obtained by pulverizing waste materials of 60 mesh or less were kneaded at a temperature of 190 ° C. and a screw rotation speed of 200 rpm to obtain dark pellets 1.

  Meanwhile, 70 parts of paper powder having a whiteness of 96% or less of 60 mesh and 30 parts of polypropylene (MFR30) were similarly kneaded at a temperature of 190 ° C. and a screw rotation speed of 200 rpm to obtain a light-colored pellet 2.

  Pellet 1 and pellet 2 were pre-blended at a ratio of 1: 9, put into a single-screw extruder, and extruded at a temperature of 190 ° C. and a screw speed of 20 rpm. As the dark pellets 1 were appropriately dispersed in the extruder, a molded product having a woody wood grain pattern as shown in FIG. 1 was obtained. It was confirmed that the dark flow pattern seen in the figure was formed by pellets containing wood flour.

Claims (4)

(A) Kneaded pellets of bleached wood fiber or wood powder and thermoplastic resin, and (B) Kneaded pellets of unbleached wood fiber or wood powder and thermoplastic resin,
A woody resin molding material characterized by containing.   2. The woody resin molding material according to claim 1, wherein the bleached wood fiber (A) is a pulverized fiber of pulp or paper.   Wood resin characterized by mixing and molding kneaded pellets of bleached wood fibers or wood powder and thermoplastic resin and kneaded pellets of unbleached wood fibers or wood powder and thermoplastic resin Manufacturing method of molded products.   4. The method for producing a woody resin molded article according to claim 3, wherein the bleached wood fibers are pulp or paper pulverized fibers.