JPH0692542B2 - Synthetic wood manufacturing method - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method for producing synthetic wood, which is used in place of natural wood. In particular, the present invention relates to a method for producing synthetic wood, which can effectively reuse a huge amount of rice husks that are not being effectively used at present.

[Prior art and its problems]

Synthetic wood has unique properties not found in natural wood. Synthetic wood is a synthetic resin molded product that has no wood grain, so it has the advantage of reducing warpage and distortion. Synthetic wood,
What is important to distinguish it from synthetic resin molded products is to mix a large amount of 50% or more of wood-based powder to finish the surface beautifully. Synthetic wood with a low mixing ratio of wood-based powder,
Only evaluated as equivalent to "cheap" synthetic resin molded products. The higher the mixing ratio of the wood-based powder, the higher the feeling of natural wood. Synthetic wood using wood powder as the wood-based powder has been developed. This synthetic wood is manufactured by mixing wood powder with a pellet-shaped synthetic resin raw material. However, the synthetic wood produced by this method has a drawback that it is extremely difficult to have uniform physical properties. The reason is that the material of wood flour varies significantly depending on the type of wood. In order to solve this drawback, a technique has been developed in which finely powdered hulls of the seeds of plants of the family Gramineae are mixed with a synthetic resin and molded (Japanese Patent Publication No. 60-11949). This publication discloses a technique of mixing fine powder of seeds of a plant of the family Gramineae with polypropylene or polyvinyl chloride resin and molding the mixture. However, when the synthetic wood is produced by this method, when the mixing ratio of the fine powder of the cereal plant is increased, the surface condition is deteriorated, and there is a drawback that a large amount of seed powder cannot be mixed to produce a high-grade synthetic wood. . By the way, when seed powder is mixed with synthetic resin raw material by this method, the mixing ratio of seed powder is 40%.
The surface condition can be finished neatly within the weight%. However, if the mixing amount is more than this, the surface cannot be molded neatly. The reason is that when a large amount of seed powder is mixed, the synthetic resin raw material and the seed powder cannot be mixed sufficiently and the fluidity in the mold is lowered. A synthetic resin having poor fluidity needs to be injection-molded at an extremely high injection pressure. This is because the frictional resistance with the mold surface is large. The synthetic resin molded in this state has the drawback that not only the surface cannot be cleanly molded, but also the seed powder on the surface is burnt by heat and deteriorates. This adverse effect becomes extremely serious when the mixing ratio of the seed powder is increased. Molded products that cannot be molded on a clean surface significantly impede the surface finish by painting. If it is painted on a surface that is not smooth, the whole surface cannot be colored uniformly and spots occur. Therefore, there is a drawback that the surface cannot be painted beautifully. The present inventor has developed a method for producing a synthetic resin molded article by treating and adding chaff in a unique method, in order to increase the amount of chaff, which is a seed of a grass family plant, (Japanese Patent Application Laid-Open No. Hei 3).
-20324). In this method, a granular or powdery synthetic resin composition is produced by the following method. The rice husk is heated under pressure to destroy the tissue and raise the temperature. It is heat-treated at a temperature of about 185 ° C to remove water from the chaff, and is kept at a high temperature for a certain period of time to cool. It is mixed with a thermoplastic or thermosetting resin and ground. When the temperature of the mixture is increased by frictional heat for crushing and the mixture of chaff and synthetic resin is about to turn into a lump from a semi-molten state, water is added. Further, it is crushed to remove water by evaporating water by heat, and the crushed chaff is impregnated with a synthetic resin to obtain a granular or powdery synthetic resin composition. According to this method, a large amount of chaff can be added to the synthetic resin composition. However, this method has the drawback of being extremely laborious to manufacture. Furthermore, since the water added in the process of crushing is vaporized by frictional heat and evaporated,
There is a drawback that a large amount of energy is required to vaporize water and the running cost becomes high. Furthermore, this method
Although a synthetic resin composition containing a large amount of chaff can be produced, it is necessary to remold the synthetic resin composition because the produced synthetic resin composition is in the form of granules or powder. further,
A synthetic resin composition having a large amount of chaff added has low fluidity in a mold, and it is difficult to easily and easily form a molded product with a clean and efficient surface. The present invention has been developed for the purpose of solving this drawback, and an important object of the present invention is to increase the mixing ratio of wood-based powders and to finish the surface neatly. In order to provide the manufacturing method of.

[Means for solving conventional problems]

In order to achieve the above-mentioned object, the present inventor repeated enormous experiments, and further microscopically observed a wood-based powder inserted into a synthetic resin with a microscope. As a result, it was found that there is a close relationship between the bonding state of the wood-based powder and the synthetic resin and the surface state of the molded product. That is, when the mixing ratio of the wood-based powder is increased, the entire surface of the wood-based powder is not completely covered with the synthetic resin, and in this state, it is found that the surface of the molded product becomes uneven and becomes dirty. . In other words, they found that when the miscibility between the wood-based powder and the synthetic resin deteriorates and the compatibility deteriorates, the surface condition deteriorates. Various additives were tested in order to improve the compatibility of the wood-based powder and the synthetic resin. However, no matter what additive material was mixed, the mixing ratio of the wood-based powder could not be increased and the surface could not be molded neatly. Then, as a result of repeating experiments further, the present inventor succeeded in significantly improving the miscibility of the wood-based powder and the synthetic resin by an extremely simple method. The synthetic wood production method of the present invention uses 5 to 80% by weight of fine powder of husks as wood-based powder. The fine powder of chaff is a fine powder of chaff. Furthermore, the method of the present invention is used to improve the miscibility between fine powder of chaff and the synthetic resin.
A two-part synthetic resin raw material that mixes liquids and undergoes a curing reaction is used. The fine powder of chaff is a two-component synthetic resin raw material, which is mixed with a synthetic resin raw material which is in an uncured state and is in a liquid or paste state, and is sufficiently stirred. Liquid or pasty uncured synthetic resin raw material in which fine powder of chaff is dispersed, and synthetic resin raw material in which two liquids are mixed is injection-molded or press-molded into a mold and molded into a predetermined shape with the mold. It is characterized by that. By the way, in this specification, the term "liquid" is used in a broad sense including not only a state of low viscosity like water but also a paste state.

[Action]

In the method for producing synthetic wood of the present invention, chaff is used as the wood-based powder added to the synthetic resin. Rice husk is not used as it is, but is processed into a fine powder and added to the synthetic resin. Further, the synthetic resin raw material to which the fine powder of chaff is added is a two-liquid synthetic resin raw material. In the uncured state, the two-component synthetic resin raw material is in liquid or paste form without heating. Fine powder of chaff is added to the two-part uncured synthetic resin raw material in this state. The fine powder of rice husk added to the liquid or pasty synthetic resin raw material is sufficiently stirred and uniformly dispersed. The two-part uncured synthetic resin raw material does not need to be heated because it melts like a thermoplastic synthetic resin. This is because it is liquid or paste at room temperature. When fine powdered chaff is added to the two-part uncured synthetic resin raw material that is liquid or paste at room temperature and stirred, the compatibility of both is extremely good and chaff fine powder is dispersed very uniformly and mixed well. To be done. Furthermore, since the two-component synthetic resin raw material is in a liquid or paste form without being heated, the fine powder of chaff will not be deteriorated by heat. A two-liquid uncured synthetic resin raw material in which chaff is processed into a fine powder and uniformly dispersed has good fluidity, and can be formed into a beautiful surface by injection molding or press molding. For example, when it is injected into a mirror-finished molding chamber, it becomes a very beautiful molded product having a mirror-finished surface. As described above, in the method for producing synthetic wood of the present invention, wood powder to be added to the synthetic resin is used as a fine powder of chaff, which is further added to the two-part uncured synthetic resin raw material. And mix well, and again
This is an extremely simple method of curing by injection molding or press molding, and it has achieved exactly the ideal feature that synthetic wood with a beautifully finished surface can be manufactured.

[Preferred embodiment]

Hereinafter, embodiments of the present invention will be described in detail. However, the examples shown below exemplify a method for embodying the technical idea of the present invention, and the method for producing synthetic wood according to the present invention includes a production process, molding conditions and the like under the following conditions. Not specific. The method of the present invention is subject to various modifications within the scope of the claims. [Example 1] Synthetic wood is manufactured by the following steps. Raw material stirring step The following raw materials are mixed and stirred. Fine powder of chaff: 70% by weight, liquid epoxy resin: 30% by weight. Use fine powder of chaff, 50-70 mesh. A two-component epoxy resin is used as the liquid epoxy resin. Fine powder of chaff is added to a liquid epoxy resin that does not contain a curing agent, and the mixture is thoroughly stirred. After the fine powder of chaff has been uniformly dispersed, a curing agent is added and the mixture is further stirred. The uncured synthetic resin raw material obtained by mixing the fine powder of chaff powder obtained in the molding step is poured into the plate-shaped molding chamber of the mold. afterwards,
The mold is clamped and the mold is cold pressed at room temperature or hot pressed. The synthetic resin in the molding chamber reacts and cures. After curing, the mold is opened and the molded synthetic wood is demolded. The synthetic wood obtained by this process had an extremely clean smooth surface even though it contained 70% by weight of fine powder of chaff. Similar to natural wood, this synthetic wood can be nailed and cut freely. In addition, this synthetic wood is used in an environment with a humidity of 90% and a temperature of 30 ° C.
The amount of deformation was observed by placing it in a room with a humidity of 30% and a temperature of 20 ° C for 10 days. As a result, almost no warpage or distortion occurred. Therefore, this synthetic wood can be effectively used as a board material for construction in place of natural wood. Example 2 Synthetic wood is manufactured by the following steps. Raw material stirring step The following raw materials are mixed and stirred. Fine powder of husks: 80% by weight, unsaturated polyester resin: 20% by weight, and fine powder of husks of 50 to 70 mesh is used. Liquid unsaturated polyester resin that does not contain a curing agent,
Add fine powder of chaff, and stir thoroughly. After the fine powder of chaff has been uniformly dispersed, a curing agent is added and the mixture is further stirred. The unsaturated polyester resin mixed with fine powder of chaffing powder obtained in the molding step is injected into the plate-shaped molding chamber of the mold by pressure. Then, the mold is clamped to cure the unsaturated polyester resin. After curing, the mold is opened and the molded synthetic wood is demolded. The synthetic wood obtained in this step had an extremely clean smooth surface, even though it contained 80% by weight of fine powder of chaff. This synthetic wood can be nailed or cut like natural wood. In addition, this synthetic wood is used in an environment with a humidity of 90% and a temperature of 30 ° C.
The amount of deformation was observed by placing it in a room with a humidity of 30% and a temperature of 20 ° C for 10 days. As a result, almost no warpage or distortion occurred. Therefore, this synthetic wood can be effectively used as a board material for construction in place of natural wood. [Example 3] Synthetic wood is manufactured by the following steps. Raw material stirring step The following raw materials are mixed and stirred. Fine powder of chaff: …… 60% by weight, liquid urethane resin: 40% by weight. Use fine powder of chaff for 50 to 70 mesh. Polyether and isocyanate are used as the urethane resin. Also, the urethane resin contains a small amount of catalyst,
Add foam material. Polyether and isocyanate are weighed and fine powder of chaff is added to this and stirred sufficiently to uniformly disperse the chaff fine powder. The polyether and isocyanate mixed with fine powder of chaff powder obtained in the molding step are poured into the molding chamber of the mold. After that, the mold is clamped and the urethane resin is foam-molded. The urethane resin mixed with foamed fine powder of chaffing powder is demolded by opening the mold. The synthetic wood obtained in this step had a smooth surface with a very beautiful surface, even though it contained 60% by weight of fine powder of chaff. Since this synthetic wood uses a urethane resin foam as a binder for fine powder of chaff, it is particularly easy to nail and cut. In addition, this synthetic wood is used in an environment with a humidity of 90% and a temperature of 30 ° C.
The amount of deformation was observed by placing it in a room with a humidity of 30% and a temperature of 20 ° C for 10 days. As a result, extremely high dimensional accuracy was maintained. Further, by using a urethane resin group having various properties with various characteristics, a non-foaming hard solid type or a water-reactive foaming type can be freely used depending on the processing application. Therefore, this synthetic wood, instead of natural wood, is NC
It can be used for the Narai master model of machines and MC machines, and is also most suitable for vacuum molding and pressure molding. [Example 4] Synthetic wood is manufactured by the following steps. Raw material stirring step The following raw materials are mixed and stirred. 50% by weight of fine powder of chaff, 50% by weight of liquid acrylic resin. Use 50 to 70 mesh for fine powder of chaff. As the acrylic resin, a liquid one in an uncured state is used. Fine powder of chaffing powder is added to acrylic resin and stirred sufficiently to disperse the fine powder of chaffing powder evenly. The acrylic resin mixed with fine powder of chaff powder obtained in the molding step is poured into the molding chamber of the mold. Then, the mold is clamped to cure the acrylic resin. The acrylic resin mixed with the hardened chaff powder is removed by opening the mold. The synthetic wood obtained in this step contained 50% by weight of fine powder of chaff, and had a very smooth and smooth surface.
This synthetic wood has the feature that it can be easily nailed. In addition, this synthetic wood is used in an environment with a humidity of 90% and a temperature of 30 ° C.
The amount of deformation was observed by placing it in a room with a humidity of 30% and a temperature of 20 ° C for 10 days. As a result, extremely high dimensional accuracy was maintained. Therefore, this synthetic wood is used as a master model of Narai instead of natural wood, and is most suitable as a mold material for vacuum forming and pressure forming. In the above examples, the mixing ratio of the fine powder of rice husk is set to 50 to 80% by weight. With this mixing ratio, the surface of the synthetic wood can be finished into a beautiful smooth surface. Therefore, it goes without saying that it is possible to set the mixing ratio of the fine powder of rice husk in the range of 5 to 80% by weight. In addition, by using the fourth example of these, for example, furniture members,
It can be used in a range of plate materials, floor materials, musical instruments, audio equipment, low-power members, electrical equipment, figurines, and the like.

【The invention's effect】

In the method for producing synthetic wood according to the present invention, fine powder of chaff is added to a liquid uncured synthetic resin raw material and sufficiently stirred. The fine powder of chaff added to the synthetic resin raw material in this state can be extremely uniformly dispersed in the synthetic resin. This is because the liquid synthetic resin raw material can be sufficiently stirred to disperse the fine powder of chaff in the pre-molding step. The fine powder of chaff and the liquid synthetic resin mixed in this step have very good miscibility, and the fine powder of chaff can be uniformly dispersed in the synthetic resin. The synthetic resin raw material in this state has the feature that if it is poured into a mold or press-molded, 80% by weight of fine powder of chaff can be mixed to form a beautiful surface state. Further, in the method for producing synthetic wood of the present invention, since fine powder of chaff can be used as the wood-based powder and the mixing ratio can be increased, a feature that homogeneous synthetic wood can be produced can be realized. Compared with wood flour, the fine powder of chaff is extremely stable in quality. The quality of fine powder of rice husk produced around the world is almost unchanged. In addition, the amount of rice husks is extremely large and is not effectively used. More conveniently,
The main component of rice husk is cellulose, which is similar to wood.
Therefore, the synthetic wood that can be produced by adding a large amount of fine powder of rice husk has a feature that the raw material cost can be significantly reduced and a large amount can be produced inexpensively. Furthermore, the synthetic wood produced by the method of the invention is
Since the surface can be made smooth, it is possible to evenly and evenly coat the surface for a beautiful finish. Furthermore, the synthetic wood produced by the method of the invention is
Since it is possible to increase the mixing ratio of fine powder of chaff, it has an advantage that it can be applied with high efficiency because it is close to natural wood, the coating finish is very smooth, it is easy to paint, and there is almost no suction of paint. Also, unlike natural wood, there is no risk of damage from pests or mold due to moisture or decay.

Claims (1)

[Claims] 1. In a method for producing synthetic wood, which comprises mixing a wood-based powder with a synthetic resin and molding it into a predetermined shape, the wood-based powder is a fine powder of chaff, which is a fine powder of chaff. Mixing ratio of fine powder of rice husk is 5-80% of total weight
In addition, the fine powder of rice husk is mixed with a liquid or paste-like synthetic resin raw material which is a liquefied synthetic resin raw material that undergoes a curing reaction when two liquids are mixed, and is mixed and stirred. A method for producing synthetic wood, characterized in that an uncured synthetic resin raw material in which fine powder of chaff has been mixed, and a synthetic resin raw material in which two liquids are mixed is injected or pressed into a mold to be cured.