JPH01171801A - Manufacture of lightweight wooden product - Google Patents

Abstract

PURPOSE:To make it possible to mold a lightweight product without using any expensive foaming agent, by adding a specified quantity of silane coupling agent to preliminarily dried woodmeal and agitating to make them react together, then adding a specified quantity of the mixture of phenolic resin, melamine resin and one or plural kinds of urea resin to the reaction product and mixing them, and thereafter heating and molding it. CONSTITUTION:100kg of 40-mesh woodmeal is heated and agitated at 100 deg.C and dried to a moisture of 5% or less. After further heated and agitated, then a water solution containing 0.1-10kg of silane coupling agent is sprayed thereto, the moisture is vaporized thereafter, and then the silane coupling agent is distributed uniformly on the surface of the woodmeal to be reacted and combined. After the woodmeal is cooled, 2-10kg of initial condensate urea resin is added thereto and agitated to react and combine the initial condensate of urea resin with the silane coupling agent of the woodmeal. After that, the obtained powder material is put into a press mold and heated at 180 deg.C and pressed at 100kg/cm<2> to obtain a lightweight wooden plate of specific weight of 0.7.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing lightweight wood products, and more specifically, a coupling agent is added to pre-dried wood flour and stirred to form a wood powder. After reacting the coupling agent on the surface, a thermosetting resin is further added and stirred to firmly bond the wood powder and the thermosetting resin gold through the coupling agent.
This invention relates to a method for producing lightweight wood products using thermosetting resin as a binder without using a foaming agent by heating and pressing the same.

[Conventional technology]

Conventionally, compositions containing 50% by weight or more of wood flour have been either thermoplastic resin-based or thermosetting resin-based, and a method of foaming them by mixing a foaming agent has been developed (Japanese Patent Laid-Open No. 59-
56411. JP-A-59-78819)! Although it can be quantified, it does not have a woody feel, and the resin-rich surface foams, making it no different from plastic foam.

Among the thermosetting resins, phenolic resin, melamine resin, and Elya resin are all made from wood flour, so attempts have been made to increase the wood flour content to 50% or more to create a woody feel.
All of them are heavy with a specific gravity of 1.36 to 1.85, and the polyester resin is also heavy with a specific gravity of 1.73 to 2.1. There is also a method for manufacturing wood-based molded products by adding a compound containing two or more epoxy groups to a piece of wood and molding it under heat and pressure (Japanese Patent Laid-Open No. 59-9041), but the product has a specific gravity of 1.19 to 1.89. It's heavy and doesn't have a woody feel to it.

There are particle boards made by heating and pressing wood chips using thermosetting resin as a binder, and hardboards made by heating and pressing defibrated wood using thermosetting resin as a binder, but these are just boards and cannot be formed into arbitrary shapes. There are drawbacks.

[Problem that the invention seeks to solve]

The present invention solves the above-mentioned drawbacks, contains 50% by weight or more of wood, uses a thermosetting resin as a binder, and does not require the use of a foaming agent. has
The purpose of this invention is to provide a technology for manufacturing lightweight wood products of arbitrary shapes that have the essence of beans.

[Specific means and actions for solving the problem] The inventor has developed a technology for molding products with a wood content of 50 to 98% by weight using wood flour as the main ingredient and thermoplastic resin as a binder (patented). No. 1299328, No. 1299fl147).

However, it is heavy with a specific gravity of 1.0 to 1.4, so various research was conducted to make it 0.5 to 0.9, which is equivalent to wood, and a foaming agent was mixed in and molded, but it was not used as a binder. Since a foaming agent is added to the synthetic resin used and the product is heated and foamed, not only does the bonding strength become weaker, but the foamed synthetic resin also comes out on the surface, giving the product a far cry from the wood-like feel of foamed plastic.

On the other hand, particle board, which is made by bonding wood pieces with thermosetting resin and forming it into a plate shape, was developed in Switzerland in 1988, and has been widely used in Japan since 1958 under the trade name Homogenholz. This particle board is generally a wood with voids, but since the raw material is wood chips and it is loose and can only be produced in the shape of a bean board, it is mainly used as a core material and is not used as a surface material. do not have.

The inventor focused on this and attempted heating and pressure molding by adding a thermosetting resin to wood flour, but found that sufficient strength can be obtained with a small amount of resin. If it exceeds the weight part, it becomes too hard and not only does it not have a woody feel, but also has a specific gravity exceeding 0.9. This is because the resin penetrates into the voids of the wood powder, and the condition is similar to that using thermoplastic resin.

In other words, in order to adjust the specific gravity of the molded product to 0.9 to 0.5,
It must be molded with considerable porosity. Now, when the true specific gravity of cellulose is 1.4 and the specific gravity of the thermosetting resin as a binder is 1.4, the specific gravity of the molded product is 0.9 to 0.5.
The porosity necessary to prepare the material must be 86 to 64%. Since the true specific gravity of wood flour is lighter than 1.4, the porosity is lower, but it still requires large pores. To do this, the surface of the wood powder must be treated to ensure strong adhesion with a small contact area.

A method for modifying the surface of wood flour is disclosed in Japanese Patent Application Laid-Open No. 50-51.
580. Japanese Patent Publication No. 51-95108. Japanese Patent Publication No. 59-156
Methods such as No. 712 have been developed, but all of them involve modification using a thermosetting resin and bonding with a thermoplastic resin. If the binder is a thermosetting resin and the modifier is a thermosetting resin, the modifier will actually hinder the bonding.

Therefore, by using a coupling agent as a modifier for the surface of wood flour and using a thermosetting resin as a binder to bond and solidify with a small contact area while leaving large gaps between the wood grains, it is possible to eliminate the use of a foaming agent. The specific gravity is 0.5 to 0.9 and the bean essence content is 50.
The present invention was completed by being able to mold a wood product with an adhesive weight of more than % by weight.

The present invention will be explained in more detail below.

The grain size of the powder used is 4 to 100 mesh. 4
Metsushi is about the same as sawdust, 100 mesh is about the same as flour, but if it is less than 4 mesh, the surface of the molded product will not be rough! +,
If the number of meshes exceeds 100, the cost of fine powder processing becomes high.

Examples of the cellulose surface modifier for wood flour include silane coupling agents, titanate coupling agents, aluminum coupling agents, and zircoaluminate coupling agents, but silane coupling agents are particularly preferred.

Among silane coupling agents, γ-aminopropyltriethoxysilane Ef2N is particularly effective in modifying the cellulose surface of wood flour and improving compatibility with thermosetting resins.
(CH2)88i (OEt)a. Silane coupling agents generally have two types of organic functional groups, one of which is highly reactive with the hydroxyl group of cellulose, and the other organic functional group is highly reactive with the thermosetting resin.

The amount of the silane coupling agent added is 0.1 to 10 parts by weight per 100 parts by weight of wood flour. If the amount added is less than 0.1 part, it will be insufficient to modify the cellulose surface, and if it is more than 4.9.10 parts, the modification effect will not only be reduced, but the cost will be high.

As a method for treating wood flour by silane coupling, the amount of coupling agent added to 100 parts by weight of wood flour is 0.
Use 1 to 10 parts by weight and increase the amount with water for uniform dispersion. That is, when wood flour is applied, the coupling agent reacts uniformly with the wood flour and water evaporates.

The thermosetting resin is not necessarily in the form of powder, but it is easier to use wood powder as it is easier to mix with wood flour, and more preferably a mixture of one or more of phenol resin, Elijah resin, and melamine resin. is good.

After cooling the wood flour whose surface has been treated with a 7-run coupling agent, 2 to 20 parts by weight of a flame curable resin are added and stirred to form a powder containing a thermosetting resin blended with the wood flour. Raw materials are made.

By putting the required amount of this powdered raw material into a compression mold and performing heating and pressure molding, a lightweight wood molded product of a desired shape can be obtained.

In order to impart some flexibility to the molded article, it is best to add a plasticizer to the thermosetting resin in advance to plasticize it.

The amount added can be from 1 to 80 parts by weight per 100 parts by weight of the thermosetting resin, if necessary.

When powdered raw materials are put into a mold and molded under heat and pressure, the powdered raw materials may not reach every corner of the mold due to the complex shape of the mold. Put the balloon in. The glass balloon used is a minute hollow silica sphere whose surface has been previously treated with a silane coupling agent. Glass balloons not only improve the flow of powdered raw materials, but also have a light specific gravity of 0.18 to 0.21, so they also work to reduce weight.

As described above, it was possible to mold a lightweight wooden product without using a foaming agent, but the wooden product according to the present invention has secondary processability similar to that of wood, and also has excellent moldability. It has various characteristics.

The first point is that products can be molded directly from wood flour.

By changing the composition of the materials, the specific gravity can be freely adjusted from 0.5 to 0.9, and the physical strength can also be adjusted accordingly.

Therefore, once a mold is made into a desired shape, it can be molded into any shape, and the more complex the shape, the greater the added value.

The second point is that the cost is extremely low because no expensive foaming agents are used and the raw material for the wood flour can be made from waste materials such as sander powder, sawdust, and thinned wood from plywood factories.

The eighth point is that by extrusion pultrusion molding and continuous heating and pressure molding using multiple rows of rolls, long wood pipes, thin plates, and other long, lightweight wooden molded products with irregular cross sections that cannot be obtained with natural wood can be manufactured at low cost and in large quantities. It is something that can be done. Practical examples include shoji and sliding door frames, handrails, thresholds, lintels, turning edges,
These include floor boards and ceiling boards. Wood pipes also have good insulation and weather resistance, making them ideal for hot water pipes in hot spring areas.

The fourth point is that in order to increase the strength, it is sufficient to add 1 to 20 parts by weight of chopped fibers to the powdered material and mold it under heat and pressure.If you want even more strength, you can insert net-like or cloth-like fibers. It can also be molded.

If stronger strength than wood is desired, insert molding of wire mesh, metal angles, metal pipes, etc. is also possible, and this method is highly reliable for structural materials used in construction.

The fifth point is that the inner surface of the compression molding mold can be engraved to form grains such as wood grain, leather grain, and cloth grain on the surface of the molded product.
By applying a sealing coating to this, it is possible to obtain a product that is extremely close to natural products.

The sixth point is that the natural wood veneer can be fixed in the mold and insert molded. That is, it is lined with a natural wood veneer, dipped in a softener to soften it, and then press-molded to solidify into the desired uneven shape. In this way, the natural wood veneer, which has been preformed in a shape that follows the uneven shape of the mold, is placed on the mold surface so that the veneer is in close contact with the mold surface, and then fixed to the mold surface by vacuum, and then the powder raw material is introduced. When heated and pressure molded, a wood product with a natural wood veneer on the surface is created. This is a very useful method that can be used as a substitute for wood products with a wide range of uses, and can be made at low cost and with good taste.

[Examples and effects]

An example of the implementation will be described below, but the present invention is not limited only to these examples.

Example 1 100 By of wood flour finely ground to 40 mesh was put into a high-speed mixer, heated to 100°C by the superheated steam passing through the jacket on the outer wall of the mixer, and stirred.
In minutes, the wood flour was dried to a moisture content of less than 5%. While heating and stirring this wood flour, add r-aminopropyltriethoxysilane (hereinafter referred to as coupling agent) o, t, Qy to 5 ml of water.
When an aqueous solution diluted to 1.5 g is sprayed, the water evaporates in about 10 minutes, and the coupling agent is uniformly dispersed and reactively bonded to the surface of the wood flour. After cooling this wood powder to room temperature, 1 osy of Eriya resin initial condensate is added and stirred for about 5 minutes.The ERIYA resin initial condensate reacts with the coupling agent on the surface of the wood flour, and the ERIYA resin initial condensate reacts with the wood powder. A powder raw material was obtained that was uniformly bonded to the powder surface.

This powder raw material was charged at 580 fr into a 10 t x 250 x 800% compression mold, heated to 180°C and compressed for 5 minutes at a pressure of 100xp/d to obtain a light wood board with a weight of 525 gr and a specific gravity of 0.7. .

By forming the mold into a desired shape such as a tray, bowl, or plate in this manner, a wood molded product of 90% wood and specific gravity of 0.7 can be obtained, which is inexpensive and has sufficient strength, making it useful as a base material for lacquerware. If the shape of the mold is complex and the flow of the powder raw material is poor, it is recommended to add a glass balloon.

Example 2 100 pieces of wood flour finely ground into 100 pieces was put into a high-speed mixer and stirred while being heated to 100°C by superheated steam passing through the jacket on the outer wall of the mixer.The wood flour had a water content of 5 in about 10 minutes. % or less. While heating and stirring this wood flour, γ-aminopropyltriethoxysilane (hereinafter referred to as coupling agent) 1.5. Q to water 5μf
When a diluted aqueous solution is sprayed, the water evaporates in about 10 minutes, and the coupling agent is uniformly dispersed on the surface of the wood powder and undergoes a crosslinking reaction and bonds. After cooling this wood powder to room temperature, add 10'lF7 of phenolic resin (resol) to 44% of methanol.
When the solution dissolved in o1p was added and thoroughly mixed and diffused, a slurry in which phenol resin (resol) was reactively bonded to the surface of the wood flour was obtained. This raw material is coated on a glass fiber tape and impregnated, heated and dried to form the phenolic resin in the β-stage.
A prepreg tape was made using JP-A-51-58.
As shown in No. 467, it is wrapped around a core metal, passed through a preheater, and then passed through a hot die for hardening and molding together with the core metal and pulled out to form a woodwind. In this way, a long, light woodwind was obtained. This wood pipe has good insulation properties, so it retains heat well, and has good weather resistance, so it is useful as a hot water pipe in hot spring areas.

Example 3 When 80 tons of wood flour i o o xy is put into a high-speed mixer and stirred while being heated to 100°C by the superheated steam passing through the jacket on the outer wall of the mixer, the wood flour becomes water-containing in about 10 minutes. It was dried to less than 5%. While heating and stirring this wood flour, γ-aminopropyltriethoxysilane (hereinafter referred to as coupling agent) o, s17 was added to water s1.
When an aqueous solution diluted to 100 g is sprayed, it evaporates into water in about 10 minutes, and the coupling agent is uniformly dispersed and reacted on the surface of the wood flour to form a strong bond. After cooling this wood powder to room temperature, add 10 μf of phenolic resin (resol) to 10 μf of methanol.
When the solution dissolved in f is added and stirred, the phenolic resin (resol) reacts with the coupling agent on the surface of the wood flour, creating a methanol slurry in which the phenolic resin (resol) is bound to the wood flour. This is coated on a nonwoven fabric to impregnate it, and then heated and dried to produce a prepreg sheet in which the phenol resin is in a β-shell state.

This sheet is passed through a preheating chamber, sandwiched between stainless steel plates, and fed out while being heated and pressurized through horizontal rows of rolls as shown in Figure 8, page 8 of JP-A-62-225881-4, to form a thin wooden plate. Obtained.

While the thin wood board was still preheated, it was put into a mold for an automobile door pack and press-molded, resulting in a curved door bag at a low cost. In order to impart flexibility to sheet products, it is effective to plasticize the thermosetting resin by adding a plasticizer in advance.

Example 4 Sander powder generated at a plywood factory contains some adhesive and paper stone powder, but more than 95% is wood powder. However, because it contains impurities, it cannot be used as normal wood flour and is only used as fuel. However, we will explain how to use this sander flour.

Pour 100 μf of sander powder into a high-speed mixer, and mix 100 μf with superheated steam leading to the jacket on the outer wall of mixer 7.
After heating and stirring at ℃ for 5 minutes to remove water, 5 ttg of r-acinoglobiltriethoxysilane (hereinafter referred to as coupling agent) was mixed with 51 g of water.
When heated and stirred while spraying an aqueous solution diluted with Af, approximately 1
In 0 minutes, the water evaporates and the coupling agent is uniformly dispersed on the surface of the sander powder and reacts to form a strong bond.

After cooling this to room temperature, a solution of 10 g of melamine resin (initial condensate) L dissolved in 1 osy of methanol was added, and when the mixture was heated and stirred for another 10 minutes, the methanol evaporated and the melamine resin reacted with the coupling agent on the surface of the sander powder. A strongly bonded powdered raw material was obtained.

On the other hand, a wood grain engraving is applied to the upper mold surface of the looper door, and a bar material made by cutting a 20% thick plywood board into a width of 8 oz is fixed to the periphery of the lower mold as a reinforcing material and a mounting member. Weigh out the powder raw material in an amount that will give a specific gravity of 0.7, put it in, and after clamping the mold, heat it to 180℃ and 100xp.
Compression molding was performed at a pressure of /d for 5 minutes to obtain a louvered door with woodgrain pattern unevenness on the front surface and plywood bar material on the periphery of the back surface. There are hinges and handles around the periphery of this door.

When installing the stopper fittings, etc., the plywood bar inserts are useful for holding the nails. In other words, the only drawback of this material, which is that it does not have the ability to hold nails, can be covered by inserting wood. Finally, by applying sealing paint to the wood grain-like unevenness, a louver door that is as close to natural wood as possible will be completed.

Natural wooden louver doors have the disadvantage of warping over time, and aluminum fittings are cold and unsuitable for indoor use. The louver door according to the present invention has an appearance similar to that of natural wood, has a woody feel, is light, shows no deterioration over time, and is much cheaper than those with wood backing or aluminum.

If the upper mold of this louver door is not engraved with wood grain, a thin plate backed and reinforced with a natural wood veneer is tightly fixed to the mold surface by vacuum force, and the natural wood veneer is molded using the method described above. A louvered door with a board on the surface is created, making it a luxury item.

After backing and reinforcing the natural wood veneer, it is soaked in a softener to soften it, placed in a mold that matches the uneven shape of the looper door, and preformed. When the veneer is tightly fixed to the upper mold, it will follow the uneven shape. The natural wood veneer is molded at the same time, saving you the trouble of gluing the veneers and creating an ideal state of perfect adhesion.Finally, both sides are painted and finished at the same time. In order to increase the physical strength of the louver door, wire mesh can also be inserted and molded. Alternatively, the hinge can be fixed in advance in the mold and molded at the same time.

〔Effect of the invention〕

According to the present invention, all the waste material mainly composed of cellulose can be effectively used by pulverizing it, and it is also possible to mold light wood products without using a blowing agent, which was previously impossible. There is no need to use expensive foaming agents, and the final product is directly molded from powder in the molding process, so there is very little loss and the product cost is extremely low.

In this way, it is not only possible to effectively use waste wood, which is mainly made of cellulose, but also to turn forest thinning wood, which cannot even be cut down, into powder, and to make effective use of it. Today, the social contribution of this invention is huge.

Claims (12)

[Claims] (1) Add 0.1 to 10 parts by weight of a coupling agent to 100 parts by weight of pre-dried wood flour and stir to react with the coupling agent on part or all of the surface of the wood flour. A lightweight product characterized by adding 2 to 20 parts by weight of a curable resin and stirring to create a powdered raw material in which the wood flour and thermosetting resin are attached or reactively bonded by a coupling agent, and then heated and pressure molded. A method of manufacturing wood products. (2) Thermosetting resin is phenol resin, melamine resin,
The method for producing a lightweight wood product according to claim (1), wherein the method is one or a mixture of two or more types of Elijah resin. (3) A method for producing a lightweight wood product according to claim (1) or (2), wherein the thermosetting resin is plasticized by adding a plasticizer in advance. (4) The method for producing a lightweight wood product according to any one of claims (1) to (3), wherein 1 to 10 parts by weight of glass balloons are further added to the powdered raw material. (5) The method for producing a lightweight wood product according to any one of claims (1) to (4), wherein the coupling agent is one type of silane coupling agent. (6) A method for producing a lightweight wood product according to any one of claims (1) to (5), which comprises adding 1 to 20 parts by weight of chopped fibers and molding them under heat and pressure. (7) A method for manufacturing a lightweight wood product according to any one of claims (1) to (6), wherein net-like or cloth-like fibers are inserted during hot-pressure molding. (8) A method for manufacturing a lightweight wooden product according to any one of claims (1) to (7), wherein metal parts are inserted during hot-pressure molding. (9) Claims (1) to (8) in which a piece of wood processed into a desired shape is fixed in a mold and molded under heat and pressure.
A method for producing a lightweight wooden product according to any of the above. (10) Any one of claims (1) to (9), in which a compression molding die is engraved during hot-pressure molding to form grains such as wood grain, leather grain, cloth grain, etc. on the surface of the molded product. A method for manufacturing a lightweight wood product as described in Crab. (11) Claims (1) to (10) in which a thin plate of natural wood such as a natural wood veneer, a piece of bamboo, or a piece of wood is fixed in a mold and insert molded during heat and pressure molding. A method for producing a lightweight wooden product according to any of the above. (12) The method for manufacturing a lightweight wood product according to any one of claims (1) to (11), wherein the weight of the molded product is 0.5 to 0.9.