JPH0316970B2 - - Google Patents

Description

Detailed Description of the Invention This invention involves mixing relatively fine wood powder as a molding aggregate into a synthetic resin material such as vinyl chloride resin and performing press molding, extrusion, injection molding, etc. The purpose is to provide a synthetic product that has a combination of features.

Therefore, one of the anticipated main objectives of the present invention is to improve molding properties by imparting characteristics to the mixed wood powder aggregate, and to prevent wear and tear of the extrusion or injection cylinder part during molding, and to improve the molding properties. The objective is to eliminate inconveniences such as breakage of molded parts and roughness on the surface of the molded product, and to improve the compatibility between the mixed aggregate and resin material, thereby providing a composite product that does not generate cavities on the surrounding surface of the aggregate. It was placed in

Next, one of the other objects anticipated in the present invention is to provide characteristics to the mixed wood flour aggregate so that a relatively large amount of aggregate can be easily produced, that is, even in the forming operation. In addition, it is possible to mix in the molded resin material on the conforming surface, and with this, cooling shrinkage distortion is small, there is no distortion, warping, cracking, etc., and the elastic modulus is higher than that of ordinary vinyl chloride molded products. The objective is to provide a composite product that is three times stronger and has a sufficiently hard surface.

Furthermore, one of the other main objectives of the present invention is to easily mass-produce and provide a material that has various characteristics unique to wood by molding it into any shape by pressing, extruding, or injection molding. It was placed in such a way that it could be done.

Another main objective of the present invention is that it has superior abrasion resistance compared to the characteristics of the material to be molded, has no shrinkage due to molding shrinkage, and is more durable than wood in actual use. This is because it has the same surface characteristics as , that is, color tone and texture, and allows for painting, adhesive construction, lamination, etc.

The method for molding a composite product according to the present invention is intended to achieve the various purposes described above, and includes the following specific examples and other equivalent examples accompanying these examples. Equal measures are planned.

A typical method for molding a composite article for building materials or fittings according to the present invention will now be explained in detail.

First, the materials to be prepared are vinyl chloride,
Thermoplastic resin materials such as ABS resin and polystyrene,
These include mixed aggregate based on wood flour, calcium carbonate powder stabilizer, coloring agent, etc. that are added as necessary.

The thermoplastic resin material used was determined and used based on the selection criteria that satisfies the various needs required for molded articles, and is used as a building material,
Vinyl chloride resin is particularly used as a material for fittings due to its strength and hardness of molded products.

The aggregate used is then prepared as a wood flour-based aggregate with a fineness of 100 mesh or more, ideally 150 mesh or more, which is molded by the following two methods: It is something.

One method is to impregnate wood chips with a liquid, ideally an emulsion type, urea resin, and then feed the chips impregnated with this resin into a crusher, where they are crushed and dried by heating. In this way, dry aggregate with a desired particle size can be provided.

The crushing process using this crusher is planned to be carried out multiple times or in multiple steps depending on the particle size of the aggregate to be produced. was planned.

In particular, in a heating drying system that uses hot air, wood chips or semi-finished aggregates are supplied into the crushing chamber with heated air at a temperature of 80 to 170°C, and processed crushed aggregates are also supplied with heated air. It was planned to be taken out.

The second method planned is to pre-treat the wood chips, turn the chips into pieces, and add and impregnate the wood chips with a liquid, ideally an emulsion type urea resin solution. The method is designed to provide molding of finely powdered dry aggregate by repeating crushing and re-crushing based on the process described above.

In other words, in this second molding method, the impregnation of the urea resin liquid is more effective, and the resin liquid penetrates deep into the chip material, and in the subsequent molding of the crushed powder, the molded aggregate is The resin liquid is evenly impregnated throughout the aggregate, making it possible to provide aggregate of uniform quality.

The aggregate provided in the presentation shall be at least 80
Aggregate with a fine particle size of 100 mesh or more, ideally 150 mesh or more, is used for resin molding, and is sieved to suit the purpose. be.

The aggregate thus provided can be heat treated during processing to reduce the water content in the aggregate by up to 13%.
Within, ideally within 3-5%, and even 0% as much as possible
This prevents the generation of water vapor during the subsequent resin molding with aggregate mixed in, and prevents the dissociation and volatilization of the wood acid contained, eliminating the possibility of acid gas generation. be.

In addition, the aggregate used is heated and dried in the pulverization process of the aggregate, and before the aggregate is formed.
That is, appropriate drying means to reach the degree of drying that is separately required in the form of wood chips, or pure wood flour, the form of aggregates during the forming process, or the form of formed particle size aggregates. This is what was considered.

In the aggregate thus provided, wood acid, especially acetic acid gas, contained in the wood flour evaporates during impregnation and heat molding with the thermosetting resin material mainly consisting of urea resin. After being neutralized, the possibility of acid gas generation is effectively reduced compared to the aggregate used in the subsequent processing in which the aggregate is mixed into a resin material and molded.

In addition, most of the water contained in the aggregate is evaporated due to the heating and drying process applied during aggregate molding, so there is no generation of water vapor, which is considered to be a problem in resin molding using molded aggregate. , there is no room for foaming, cavities, rough skin, etc. to occur in the molded product. still,
Removal of this water content can also have a significant effect on the volatilization of wood acid contained in wood flour, and wood acid contained in wood flour usually reacts with H ₂ O groups. This is effectively inhibited by dissociation and volatilization.

Therefore, the above-mentioned impregnation of the thermosetting resin material eliminates the wood acid produced in the process of heating crushing and hardening, and the generation of wood acid gas from the aggregate is more effectively suppressed. .

Avoiding the generation of wood acid gas in such aggregates has an extremely important meaning in subsequent resin molding. That is, when wood acid gas is generated during resin molding, the cylinder screw of the press, extruder, or injection machine used for resin molding, or the inner wall surface of the molding die or mold, is oxidized and corroded.
This drastically reduces its service life and also reduces its molding efficiency, particularly causing the problem of molding defects due to uneven extrusion and injection pressure.

In addition, unlike the usual pure wood flour, the surface resistance value of the aggregate is extremely reduced due to the hardening resin being impregnated or attached to the aggregate. The extrusion and injection pressure when mixed and molded into the material is almost similar to that of common resins. On the other hand, in the past, the mixing of wood powder caused the wood powder to slide against the inner circumferential surface of cylinders, dies, etc., causing frictional resistance, and when extrusion and injection were performed, cylinders, dies, etc. This causes scratches, abrasion, or damage on the inner circumferential surface of the

Furthermore, the use of such aggregates ensures good compatibility with the mixed resin material, ensuring uniform mixing of the aggregates,
In addition, it is possible to eliminate as much as possible the voids that occur on the peripheral surface of the aggregate in the molded product, thereby making it possible to provide a molded product with the desired quality.

The calcium carbonate powder prepared next is used as needed to prevent molded products from deforming during extrusion processing, etc., and to keep the unit price of molded products low since calcium carbonate itself is particularly cheap. It is something that

In addition to these materials, a separate stabilizer such as lead was prepared in an attempt to prevent deterioration in the molded product and to reduce as much as possible the frictional resistance that occurs during extrusion processing.

Furthermore, when the molded product is to be colored, a corresponding coloring agent is prepared. For example, when the molded product is made white, titanium oxide is mixed in.

The materials described in detail above include those that are provided in the form of pellets by being pre-mixed with a resin material such as vinyl chloride resin, and those that are mixed into powdered resin such as vinyl chloride resin. In some cases, it is supplied as a resin molding machine, and it is selectively supplied and used depending on the type of resin molding machine, etc. used.

Therefore, when making pellets, first, mix the above-mentioned aggregate within 50wt% with the powdered resin, add calcium carbonate within 10wt% as necessary, Further, necessary stabilizers, lubricants and colorants are mixed and kneaded and heated to obtain pellets for molding. Using the pellets for molding thus obtained, the desired synthetic product was obtained by the same method as in ordinary resin molding.

Another method that will be planned next is to use a method similar to that used for pellet production, in which various materials are put into a molding machine to directly obtain a molded product, kneaded, and molded by heating.

In addition, since the above-mentioned aggregate is planned to be mixed, the main molding methods for such resin molded products are generally press molding, extrusion molding, or injection molding, and extrusion foam molding is partially planned. It is what was done.

The amount of aggregate to be mixed is determined according to the resin molding method and the characteristics of the molded product, and is approximately within the range of 20% to 50% by weight.

Furthermore, depending on the resin material used, the amount of aggregate, the molding method, etc., the processing temperature can be set within the range of about 110°C to 140°C, and the above-mentioned characteristics can be expected to be achieved specifically. This makes it possible to provide a synthetic product that has the advantages of plastics.

In particular, it is now possible to easily mold various molded products that were previously considered almost impossible to mold due to the fact that the wood powder mixed in with the wood powder produces wood acid gas, or that the wood powder has particularly high slip resistance. It could have been done. In addition, the molded product is compatible with the resin material used due to the characteristics of the mixed aggregate, and has good quality characteristics.
This could be provided with normal molding efficiency.

In addition, due to the characteristics of the aggregate, it does not induce excessive frictional resistance or cylinder pressure in the molding machine itself, and also prevents the inner peripheral surfaces of the cylinder and die from becoming rough. The depletion rate is particularly low.

As mentioned above, the molded product thus provided has excellent water resistance, abrasion resistance, and impact resistance characteristics with a woody feel, and has a hard surface, and is free from molding distortion due to sink marks etc. , distortion, warping, cracking, etc. after molding are reliably prevented, and the elastic modulus is also particularly good.

In addition, the thermal deformation rate is low, and at the same time, machinability, paintability,
It has adhesive properties, nailing properties, etc., and is said to have particularly good construction properties.

Note that the wood used can be either softwood or broadleaf, since the wood is made into fine short fibers, that is, fine powder, without being crushed and used as cellulose fibers.

The method for molding a wood-like synthetic product according to the present invention includes the above-mentioned method, and actual molded products are used as architectural members, such as door frame materials, window frame materials, surrounding edging materials, baseboards, and curtains. Boxes, parting edges, angles, tesri, flooring materials, wall materials, thresholds, lintels, doorstops, etc., as well as fittings such as shoji frames, doors, kamachi doors, louvers, etc., for furniture, automobiles, ships, etc. A wide range of uses are planned, including home appliances, various cabinets, sinks, and more.

Claims (1)

[Claims] 1. Adding and impregnating wood chips with a thermosetting resin liquid,
A method for molding a wood-like synthetic material, which comprises crushing and drying this material to obtain a finely powdered dry aggregate, and mixing the aggregate into a thermoplastic resin material to perform heat molding. 2. A method for molding a wood-like synthetic product according to claim 1, characterized in that the wood chips are chips in the form of crushed pieces.