JPS6245052B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides a plain white wood flour aggregate that has particularly good conformability and molding properties to mixed resin materials, thereby improving wear resistance, bending strength properties, and processing properties. The object of the present invention is to provide a reinforced resin molded product having excellent and low thermal expansion characteristics.

(Prior art) Previously, the reinforcement of this type of synthetic resin molded product was usually planned by adding or mixing inorganic materials such as glass fiber or rock wool. In order to maintain low molding costs, wood powder or similar cellulose substances have recently been mixed into resin materials such as polyvinyl chloride, polyethylene, and acrylonitrile-butadiene-styrene. This was an attempt to strengthen resin molded products.

Mixing the required amount of wood powder into such molding resin increases the strength of the resin molded product, especially the bending strength, approximately twice that of the non-mixed resin molded product, and also reduces distortion during resin molding and after molding. It has a significantly low wear resistance and particularly improved wear resistance, and is particularly meaningful in providing ideal and inexpensive reinforced resin molded products.

However, in such conventional methods, the material characteristics of the mixed wood powder itself are directly reflected on the surface of the molded product, and it is not always satisfactory in terms of mass, color tone, gloss, etc. In addition, voids or nests are formed on the surrounding surface of the mixed wood powder, which causes various problems not only in terms of appearance but also in terms of strength.

In addition, it is not always possible to take sufficient measures to prevent the wood acid contained in the wood powder that is mixed into the wood powder, and equipment, especially cylinders, etc. that are affected by acetic acid gas generated during molding.
This is caused by problems such as corrosion and wear on the die or mold surface.

(Objects and Structure of the Invention) In the resin molding method according to the present invention, in order to eliminate such inconveniences in handling the mixed wood, the process of producing the powder aggregate is devised and the resin material used is It has good familiarity characteristics,
In addition, it has good sliding properties, so it has good molding properties in extrusion molding, etc., and is designed to suppress fatigue and wear and tear of equipment during molding as much as possible.

Therefore, the method of molding a wood-like reinforced resin molded product according to the present invention was devised to achieve such an objective, and the gist of its structure is that it is produced by crushing or cutting wood. After bleaching and decolorizing the wood chips, a liquid thermosetting resin material is added and heated to harden, and the heat-hardened chip mass is cut to obtain dry aggregate in the form of fine powder of 300 μm or less. Based on the process and the process of mixing this dry aggregate into the molding resin material in a proportion that corresponds to the molding purpose and forming the mold, the following specific examples and examples will be described. We plan to make considerable design changes in conjunction with this, and we promise to provide the molded product with a pure and uniform white plain wood grain-like appearance, color tone, and sense of mass.In addition, the molded product surface will be particularly dense and smooth, and the molded product will have a particularly dense and smooth surface, with no nests, etc. This makes it possible to provide reliable molded products free from molding with relatively good molding efficiency.

(Example) An example of a typical molding method for a wood-like reinforced resin molded product according to the present invention will be described below. 1 is a wood chip that has been crushed or cut using an appropriate device such as a chopper, It has a color and texture unique to the wood used, and also contains acetic acid, commonly called wood acid. Such a chip 1 is decolored by an appropriate method such as immersing it in a bleach solution 2, and the pigment content is usually decolored by the sodium hypochlorite method, hydrogen peroxide method, An appropriate bleaching method such as the sodium chlorite method was used. In addition, in order to return the PH group to neutrality as much as possible during bleaching and water washing, etc., the material is immersed in dilute sulfuric acid solution and subjected to acid treatment, and is also thoroughly washed with water to ensure that no acid or chlorine remains. .

In this way, the unique pigments are decomposed and the chip 1 is made into a uniform white color. Two liquids or powder of a thermosetting resin such as polyurethane resin, urea resin, or urea resin are added to the chip 1, and the chip is heated using a hot press method or the like. The chip mass 3 was obtained by hardening.

In such hot press treatment, the temperature is approximately 130℃.
Due to the press processing before and after, the water content in the chips 1 is reduced to about 3 to 8%, and during the above treatment, the remaining wood acid, chlorine, or acid is dissociated and volatilized. After this dissociation and volatilization, there is no room for the weak to strong acid or strong alkaline gas contained in the chips 1 to dissipate.

Next, the hot-pressed chip mass 3 is processed using an appropriate method, such as a polishing device, a crushing device, or a fine-grain cutting device, to form aggregate 4 in the form of fine powder of about 50 to 150 meshes (300 μm to 100 μm).
That is. In order to further remove the moisture contained in the chips 1 during this polishing or crushing process, a drying process using hot air at a temperature of 130 DEG to 150 DEG C. was separately scheduled.

The aggregate 4 thus produced and provided does not have the various disadvantages of common wood powder aggregates even when incorporated into the resin material 5.
This material could be used as an excellent resin aggregate.

That is, since the particle size of the aggregate 4 is particularly fine, it is said to have good compatibility with the resin material 5,
It is evenly kneaded in a uniform proportion with the resin raw material powder, etc., and when it is heated and molded, the peripheral surface of the aggregate 4 is completely surrounded by the resin material 5, and the frictional resistance during molding is almost negligible. It is close to that of the resin material 5 used, and any inconveniences during injection or extrusion molding can be reliably prevented.

In particular, the problem of frictional resistance in the aggregate 4 is due to the fact that the aggregate 4 is cured sufficiently hard with the thermosetting resin 2, and the rough surface like that in ordinary flour has been wiped away. Therefore, the extrusion pressure or injection pressure is almost the same as that for the resin material 5 used.

In addition, in the molding of the chip mass 3 described above, when using a resin 2 which is unique, that is, which induces alkaline gas, as the material for the jumpsuit, neutralization of the wood acid in the chip 1, especially the effectiveness of a weak acid type resin, is required. A chip mass 3 that has been subjected to a neutralization treatment beforehand and has the desired properties only by treatment with "strong alkali-strong acid" during subsequent bleaching.
is what was obtained.

Incidentally, the problem of frictional resistance in such mixed aggregates is not only a problem of surface roughness of extruded or injected molded products, but also causes of wear and tear on the cylinder surface, breakage of the die, breakage of the mold, etc. It is.

Next, by setting the moisture content to an extremely dry state, various problems arise due to the generation of water vapor during heating for forming and the acidic gas of this generated water vapor, especially the problem of cavities or isolated voids occurring on the surrounding surface of the mixed aggregate. This solves the problem of corrosion of cylinders, dies, or mold surfaces, and allows the mixed aggregate 4 to be incorporated into the resin material 5 without any voids, allowing it to function as an original aggregate. In addition to this, it also reliably prevents the generation of wood acid gas.

In addition, with this method, even when the total amount of mixed aggregate is increased compared to the conventional method, sufficient extrusion or injection is possible, and it is possible to perform arbitrary molding of plain white wood-like resin material. This made it possible.

In order to more reliably suppress the increase in the water content of the aggregate 4 mentioned above, the dried aggregate 4 can be kneaded in advance with a resin material intended for molding and prepared as appropriate pellets 6. This method was planned separately, and it was said that the management of the aggregate 4 would be particularly easy, and it was promised that reinforced resin molded products could be produced on-site using only conventional extrusion or injection operations. be.

In addition, the resin material 5 mentioned above is not only heat-softening resin materials such as vinyl chloride, polypropylene, polyethylene, and polycarbonate, but also other thermosetting resins such as ABS resin are separately planned due to their molding characteristics. It is something that

Next, in these resin moldings, especially when foaming is included, the following properties have been found to be effective.To explain this in detail, aggregate 4 in the above is made of polyurethane resin, urea resin, etc. It is resistant to resin and mixed at a ratio of 60 to 80%, and a foaming material with a relatively low boiling point such as freon, propane, butane, or pentane and a polymerization catalyst are mixed in and poured into a mold and heated at room temperature. Alternatively, a foamed wood-like reinforced resin molded product can be obtained by heating and foaming.

The resin product thus molded and provided consists of aggregates 4 to 4.
Foamed voids 7 are formed between them, and the aggregates 4 to 4 are each encapsulated with a resin film 8 to form a connected and integrated structure, as if the aggregates 4 and voids 7
and are connected and configured in a honeycomb manner with a membrane 8.

In particular, in such a structure, while the aggregates are in contact with each other, complete foamed voids 7 are formed between the adjacent aggregates, and moreover, they are covered with a honeycomb-like coating 8. By linking them together, specific effects on the above-mentioned properties can be expected.

That is, since the aggregates 4 to 4 are configured to abut each other, weakness in the load-bearing strength is avoided, and the honeycomb-like structure characteristic of the coating 8 increases bending strength and impact resistance. , the shape retention strength, etc. has been dramatically improved, and the amount of resin material used has been reduced, resulting in inconveniences as a resin board, including the occurrence of molding distortion, the generation of harmful gases during combustion, and the occurrence of cracks during nailing. The aim is to eliminate the possibility of this occurring, and to improve the heat insulation properties over that of wood materials.

In addition, since all of the aggregate 4 is encapsulated with a film 8, it has water resistance despite being a wood-like material.
It is said to have particularly good chemical resistance, and is expected to have properties not normally found in wood materials.At the same time, unlike resin boards, it is possible to perform processing such as cutting and nailing in the same way as regular wood materials. It is something that

In addition, although the main raw material of the material is wood flour as an aggregate, the presence of the resin film 8 makes it possible not only to mold it, but also to mold it or process it in the same way as other resin plates. It is.

(Effects of the Invention) The wood-like resin molded product according to the present invention is provided as having the characteristic structure, action, and effect described above, and also has the above characteristics by using the same molding method as in ordinary resin molding. This makes it possible to provide a molded product, and in particular, it has made it possible to provide a good molded product that has a low coefficient of thermal expansion and has little distortion due to changes in composition during and after molding.

In addition, the bending strength as a mechanical property is strong, and of course the hardness is also sufficient, and the surface abrasion resistance is significantly improved.

Furthermore, in terms of materials, wood is used as the main raw material and resin is used as the molding means, making it possible to process with ordinary woodworking machines and tools, and also perfect surface treatment with lacquer, paint, etc. ,
At the same time, the mixed wood flour ensures that the molded product has the unique color tone and feel of wood.

Furthermore, since the pigment contained in the mixed aggregate 4 has been removed and the color is uniformly white, variations in color or mass feel on the surface of the molded product may occur due to changes in the type and properties of the mixed aggregate. This technology promises to provide a molded product with a uniform color tone and mass, and effectively eliminates restrictions on the quality of the wood used.

In particular, as a woodworking material, the entire cut surface exhibits the characteristics of plain white wood, and unlike the wood-like materials that have been sprayed, molded, or pasted with decorative sheets in the past, it should be made clear that it is a synthetic resin material. It has no effect.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the chips used in the molding method of the present invention, Fig. 2 is a sectional view showing the bleached state, Fig. 3 is a side view showing the hot pressing process, and Fig. 4 is the final molded aggregate. FIG. 5 is a partially enlarged sectional view of a resin molded product, FIG. 6 is an enlarged sectional view of a pellet, and FIG. 7 is a partially enlarged sectional view of a foamed resin molded product. In the figure, 1...wood chips, 2...thermosetting resin,
3... Chip mass, 4... Aggregate, 5... Resin material, 6... Pellet, 7... Foaming void, 8... Film.

Claims (1)

[Scope of Claims] 1 A step of bleaching and decolorizing wood chips produced by crushing or cutting wood, adding a liquid thermosetting resin material and heating and hardening the heat-hardened chip mass; It consists of a process of cutting to obtain dry aggregate in the form of a fine powder of 300 μm or less, and a process of mixing this dry aggregate into a molding resin material in a proportion that corresponds to the purpose of molding and forming it. A method for molding a wood-like hardened resin molded product. 2. The wood-like reinforced resin molded product according to claim 1, wherein the water content in the aggregate is set within a range in which acidic gas or alkaline gas is not dissociated from the aggregate during resin molding. Molding method.