JPH047282B2 - - Google Patents

Description

[Detailed description of the invention] This invention involves mixing bleached wood flour, etc. whose pH value has been adjusted to slightly alkaline, as a molding aggregate into a synthetic resin material such as vinyl chloride resin, and performing press molding, extrusion, injection molding, etc. The purpose of this invention is to provide a synthetic product that has the features of both wood and resin.

Therefore, one of the anticipated main objectives of the present invention is to improve molding properties by imparting characteristics to aggregates such as bleached mixed wood flour, which can be used in extrusion or injection cylinders during molding. A synthetic composite product that eliminates inconveniences such as wear and tear on parts and damage to dies, and roughness on the surface of the molded product, and also improves the compatibility between the aggregate and resin material to be mixed, and does not generate cavities on the surrounding surface of the aggregate. It was designed to provide the following benefits.

Another object of the present invention is to impart characteristics to aggregates such as bleached mixed wood flour, so that relatively large amounts of aggregates can be produced easily, that is, on molding surfaces. It also prevents contamination on the conforming surface of the molded resin material, resulting in less distortion due to cooling shrinkage and less distortion, warping, and
The aim is to provide a composite product that is free from cracks, has a modulus of elasticity more than three times that of ordinary vinyl chloride molded products, and has a sufficiently hard surface. be.

Furthermore, one of the other main objects anticipated by the present invention is to easily mold materials such as wood into any desired shape by pressing, extrusion, or injection molding. This was done in such a way that it could be mass-produced and provided.

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. etc., similar surface properties,
In other words, color tone, texture, paint finish, adhesive construction,
The aim is to provide products that can be laminated.

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,
Mixed aggregate based on cellulose material such as wood flour, calcium carbonate powder, hardening agent such as ammonia chloride, hydrochloric acid, stabilizer, coloring agent, etc. 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 next was bleached, neutralized and slightly alkaline by the following method.

That is, by applying an alkaline bleaching agent, especially caustic soda, to crushed wood chips, pulp, or rice husks, the pigments of the material are removed, the color tone is uniform, and the composition of the material is changed by this caustic soda treatment. The material is destroyed by the following process, especially the impregnation with a thermosetting resin liquid, to facilitate the following treatment. In addition, as a result of this caustic soda treatment, the material pH was 10.4, indicating strong alkalinity. Next, this bleached material is subjected to a drying process, particularly a heat drying process, to reduce the moisture content in the material to 15%.
% or less.

As the moisture content in the material decreases to 15% or less, the drying process rapidly induces destruction of the constituent fiber composition of the material, resulting in the crushed chips becoming rough bundles or lumps of cellulose. In addition, the compositional state of the cellulose in the pulp material and rice husk is certainly destroyed, and the cellulose is separated.

By applying an emulsion-type urea-based resin adhesive to the bleached material that has dried and whose composition has disintegrated, and leaving it for 20 to 30 minutes, this urea-based resin adhesive can be removed. It is sufficiently impregnated into the material.

In addition, separate attempts have been made to adjust the pH value of the material toward neutrality by adding ammonia chloride or hydrochloric acid as a hardening agent to this resin adhesive liquid, as necessary.

In the next step, the material impregnated with the urea-based resin liquid and cured is heated and dried at a temperature of 100 to 150°C, and then crushed and pulverized. within 3-5% and 0% as much as possible
It is made into fine powder with a particle size of about 100 to 150 mesh.

During such heat drying and crushing, the material itself
It has a pH value of around 8, and is adjusted to be slightly alkaline.

The neutralization treatment of the acidic material at such a starting point is
A simple heating and drying treatment of bleached cellulose-based materials that relies heavily on the action of a urea-based resin adhesive that is interposed during processing, and for which no urea-based resin adhesive is planned to be added. In this case, although the starting point bleaching material had a pH of 10.4, showing strong alkalinity, the final point material, which was made into a dry fine powder, had a pH of 2.4, indicating a strongly acidic pH value. be. In contrast, by interposing a urea-based resin adhesive, a bleached material with a pH of 10.4 is neutralized while gradually releasing the acetic acid contained in the material as wood acid gas as it is heated and dried. PH of the material at a point
It is adjusted so that it is within the weak alkaline range of around 8.

The bleached aggregate thus provided is heated during processing to maximize the water content in the aggregate.
Within 13%, ideally within 3 to 5%, and even as much as possible to 0%, to eliminate any room for water vapor to occur during subsequent resin molding with aggregate mixed in.
In addition, the bleached aggregate is made into a weakly alkaline material in order to prevent the dissociation and volatilization of the wood acid contained therein, thereby eliminating the possibility of generation of acidic gases, and to proactively neutralize the aggregate itself.

The bleached aggregate used may be used in the form of wood chips or pure wood powder, which is heated and dried during the molding process of pulverizing the aggregate, and before the molding of the aggregate. Appropriate drying means were studied to reach the degree of drying that is separately required in the form of aggregates or formed granular aggregate.

In the bleached aggregate thus provided, the wood acid contained in the wood flour, especially acetic acid gas, evaporates during impregnation and thermoforming with the thermosetting resin material mainly composed 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 moisture contained in the aggregate is evaporated due to the heating and drying process applied during molding of bleached aggregate, which prevents the generation of water vapor, which is considered to be a problem in resin molding using molded aggregate. No foaming in the molded product,
This eliminates the possibility of cavities, rough skin, etc. Furthermore, the removal of this water content can also have a significant effect on the volatilization of wood acid contained in wood flour, and the wood acid contained in wood flour usually reacts with H20 groups. This effectively prevents dissociation and volatilization from occurring for the first time. Therefore, the impregnation of the thermosetting resin material eliminates the wood acid produced during the heating crushing-hardening process, adjusts the pH to 6 to 7 by neutralization, and suppresses the generation of residual wood acid gas from the aggregate. This makes it even more effective.

The effective elimination and prevention of wood acid gas generation in bleached aggregates had an extremely important meaning in subsequent resin molding. In other words, when wood acid gas is generated during resin molding, the cylinder screws of presses, extruders, and injection machines used for resin molding, or the inner wall surfaces of molds or molds, are oxidized and corroded, reducing their service life. This drastically reduces the frequency and also reduces the molding efficiency, causing the problem of molding defects due to uneven extrusion and injection pressures.

Also, unlike ordinary pure wood flour, bleached aggregate has a hardening resin impregnated or attached to it, which dramatically reduces the resistance value of the surface, making the aggregate As a result, the extrusion and injection pressure when mixed and molded into a resin material is almost similar to that of general resins. On the other hand, in the past, the mixing of wood flour caused the wood flour to come into sliding contact with the inner peripheral surfaces of cylinders, dies, etc., causing frictional resistance.
In the case of extrusion or injection, scratches, wear, or damage may be induced on the inner peripheral surfaces of cylinders, dies, etc. Furthermore, the use of such bleached aggregate improves compatibility with the mixed resin material, ensures uniform mixing of aggregate, and eliminates as much as possible the voids that occur around the aggregate surface in molded products. This makes it possible to provide molded products 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, if the molded product is to be colored, a corresponding coloring agent is prepared.For example, if the molded product is to be colored white, titanium oxide is planned to be mixed in.

The materials described in detail above are provided in the form of pellets by being premixed 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 bleached aggregate within 50wt% with the resin powder, 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 preparation, 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 mixing of the bleached aggregate is planned, the main molding methods for such resin molded products are generally press molding, extrusion molding, or injection molding, with extrusion foam molding being used in some cases. It was planned.

The amount of bleached 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 50wt%. .

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℃ to 170℃, and the above-mentioned properties can be expected to be achieved specifically. This makes it possible to provide a composite product that combines 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 bleached 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 roughening of the inner peripheral surfaces of the cylinder and die, making it easy to use the equipment used. The depletion rate in the process is particularly low.

As mentioned above, the molded product thus provided has a white or uniform color tone, has a woody feel, and has excellent water resistance, abrasion resistance, and impact resistance.
It has a hard surface, reliably prevents molding distortion due to sink marks during molding, distortion, warping, cracking, etc. after molding, and has a particularly good elastic modulus.

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.

When the material used is wood, both softwood and broadleaf trees can be used as cellulose fibers by making fine short fibers, that is, fine powder, without crushing the wood.

The method of molding the wood-like composite material according to the present invention consists of the above-mentioned method, and in actual molded products, it can be used as architectural members that are particularly guaranteed to have a uniform color tone, such as door frame materials, window frame materials, and surrounding materials. Edge materials, skirting boards, curtain boxes, edge edges, angles, tesli, flooring materials, wall materials,
Sills, lintels, doorstops, etc., as well as fittings such as shoji frames, doors, stile doors, louvers, etc., as well as furniture, automobiles, ships, home appliances, various cabinets, sinks, and a wide range of other uses. It was planned.

Claims (1)

[Claims] 1. Bleaching crushed chips, pulp, rice husks, and other appropriate cellulosic materials with an alkaline bleaching agent, and then impregnating the bleached material obtained by drying this with a urea resin solution, A process of impregnating, drying and crushing in a temperature range of 100℃ to 150℃ to form fine aggregate with a pH of around 8, and mixing this bleached fine aggregate with vinyl chloride and other thermoplastic resins. A method for molding a wood-like synthetic object, comprising the steps of resin molding using an appropriate molding method. 2. The method for molding a wood-like synthetic material according to claim 1, characterized in that the alkaline bleaching agent is sodium hydroxide. 3. A method for molding a wood-like synthetic material according to claim 1, characterized in that the bleaching agent is dried so that the moisture content of the material is within 15%. 4. The method for molding a wood-like synthetic material according to claim 1, characterized in that the particle size of the aggregate is 100 mesh or more and the water content is 5% or less.