JPH01145103A - Manufacture of fire-retardant woody product - Google Patents

Abstract

PURPOSE:To obtain a fire-retardant woody product which is high in a degree of woodiness, easy in secondary processing and free from generation of harmful gas, by a method wherein substance mainly comprised of a pulverized cellulose is made fire-retardant by impregnating the same with a moistureproofing and flameproofing agent and the same is heated and molded by adding powdery thermosetting resin as a binder. CONSTITUTION:When pulverized wood flour is loaded into a Henschel mixer and agitated while heating at 100 deg.C by superheated steam communicating with a jacket of an outer wall of the mixer, the wood flour is dried down to water content of 5% or less. When a 1-30pts.wt. moistureproofing and flameproofing agent is loaded per 100pts.wt. of the same and heating and agitating of the same is performed, fire-retarded wood flour, which is impregnated and coated evenly with the flameproofing agent, is obtained. When a solution obtained by dissolving a 2-30pts.wt. urea resin precondensate into methanol is loaded into the same for heating and agitating, the methanol turns fugacious and the flour where urea resin has been attached evenly to the fire-retarded wood flour is obtained. When compression molding of the flour is performed at pressure of 100kg/cm<2> while heating at 180 deg.C by loading the flour into a mold, carbon resin is cured and a fire-retardant woody product having urea as binder is obtained.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for manufacturing flame-retardant wood products, and more specifically, after impregnating and coating a material mainly composed of cellulose that has been pulverized in advance with a flame retardant, a thermosetting resin is applied. The present invention relates to a method for producing a flame-retardant wood product, in which the mixture is uniformly mixed, and then heated and press-molded.

[Traditional technique! N1 As a method for making wood flame retardant, a method has been developed in which water-soluble inorganic ions react with each other in the wood to generate water-insoluble and nonflammable inorganic substances in the wood (Japanese Unexamined Patent Application Publication No. 1983-1992). -248602). The disadvantage of this method is that it takes a long time to inject or impregnate water-soluble inorganic ions into the wood, and there is a difference in flame retardancy between the surface and the interior. In fact, when wood that has sufficiently absorbed water is immersed in an aqueous solution of barium ions and then in an aqueous solution of phosphate ions, the barium phosphate salts are generated and penetrate into the interior of the wood, making the wood flame retardant. However, the thickness of the wood is 3 to 5 ml.
- It takes about 8 hours for the r board. Furthermore, since it must be washed with water and dried, the productivity is very poor. Furthermore, it is inevitable that the inorganic substances produced inside the wood will vary depending on the tree species, resin, temperature, humidity, etc. Next, there are cement boards made of wood wool, which is recognized as a quasi-noncombustible material by JIS, but the cement content is 501% by weight compared to 50% by weight of the wood, and although the board shape is highly flame retardant, it has a poor appearance. is close to cement board and far from wood. In addition, it is impossible to process with ordinary wood processing tools, so it cannot be used as a flame retardant wood.The inventor also impregnated wood flour with a flame retardant and made it with vinyl chloride resin added with a flame retardant. Although a flame-retardant wood was made by solidifying the wood, when it was exposed to flames, the surface of the wood charred and produced chlorine gas, which was harmful to humans and animals, so it could not be put to practical use. [Problems] In the conventional method of making wood flame retardant by producing inorganic substances in the wood, the productivity was very low and the flame retardancy inside the wood varied.Also, wood wool cement board However, when using vinyl chloride resin, there was a problem with the generation of chlorine gas. The object of the present invention is to provide a method for manufacturing flame-retardant wood products that are easy to process and do not emit harmful gases with high productivity and at low cost. We have developed a technology for molding micronized materials using thermoplastic resin or thermosetting resin as a binder to form products containing 50 to 98% of cellulose-based substances, and have put this into practical use. When a molded product was made using vinyl chloride resin as a binder in the first step, the flame retardancy was good, but when the flame hit the molded product, the surface of the molded product carbonized and the vinyl chloride resin was removed. It was found that it could not be put to practical use because it decomposed and generated chlorine gas, which is harmful to humans and animals.The second step was to impregnate a substance mainly composed of pulverized cellulose with a moisture and flame retardant as shown in Patent No. 782936. When this was heat-molded using a powdered thermosetting resin as a binder, a wood product that did not emit harmful gases was obtained.The degree of flame retardancy was determined by flame retardant tests on building interior materials and construction methods. Although it passed grade 1 flame retardancy in the method (J 15-A 1321), in order to further increase the degree of flame retardancy, a flame retardant was added to the thermosetting resin and the wood was molded under heat and pressure. By applying a flame-retardant paint to the surface of the product, we obtained a flame-retardant wood product that passed JIS semi-nonflammability, completing the present invention.In addition, the product of the present invention is a semi-non-flammable material and a flame-retardant material according to Notification 1231 of 1972. It passed the fourth gas toxicity test and was certified to be non-toxic to humans and animals.The present invention will be described in more detail below. degree, but
The finer the finer the better, but use 4 to 100 pieces. 4 mesh is about the same as sawdust, and 100 mesh is about the same as powder. If it is less than 4 meshes, there will be variations in flame retardancy, and if it is more than 100 meshes, the cost of pulverization will be high (
Therefore, a problem arises in terms of profitability. There are various flame retardants based on cellulose, including phosphorus-based, bromine-based, antimony-based, and others, but as a result of experiments, the flame retardant that is most compatible with cellulose is the phosphorus-based flame retardant. A flame retardant prepared by adding a dilute solution of alumina sol and a dilute solution of colloidal silica to an aqueous solution of an organic phosphorus compound while stirring at high speed was the easiest to use (and most effective).A liquid flame retardant is effective; If the impregnating ratio of a substance mainly composed of cellulose (hereinafter referred to as cellulose powder) is less than 100 parts by weight of cellulose powder, it will be completely impregnated (no flame retardant effect).
If the amount exceeds 30!1i parts, it is not suitable because the cost is high (not only does it take away the wood texture).The flame retardant does not necessarily have to be in liquid form, but it has a better dispersion effect.Liquid flame retardants include cellulose. Since the speed of impregnation into the powder is fast, it is necessary to add the flame retardant while stirring the powder at high speed.This is because variations in the degree of impregnation of the flame retardant will cause variations in the flame retardancy of the product. Since the liquid flame retardant is impregnated and coated on the cellulose powder, the processing speed is very fast.Compared to the flame retardant treatment time for cellulose powder of 100 mm, which is only 30 minutes, It takes 10 hours to infiltrate water-soluble inorganic ions into the inside of beech wood to make it flame retardant, and the productivity is not comparable to that of the present invention.Furthermore, the flame retardant wood product of the present invention has It is homogeneous and has the same effect no matter where it is cut.Next, regarding the binder, thermoplastic resin has a low heat resistance due to its characteristics (and is difficult to make flame retardant, so it has the highest flame retardancy). Vinyl chloride resins with high heat resistance cannot be used because they generate chlorine gas when heated.Thermosetting resins have high heat resistance and flame retardancy, so 2 to 30 parts by weight of thermosetting resins are A flame-retardant wood product is produced by uniformly dispersing and mixing with the combusted cellulose powder and then heating and press-molding it.The addition rate of the thermosetting resin is 10 parts of cellulose powder (minimum Zffiffi parts per lffi parts is required). If it is less than this, it will not be possible to obtain the strength of the product.Additionally, if it is added in excess of 30 ffi parts, the product hardness will be too high (it is not suitable because it will not only lose its woody feel but also make secondary processing difficult).Thermosetting resin is preferably in powder form, but is not necessarily limited to powdered ice.However, since the substance mainly composed of cellulose is in powder form, the thermosetting resin is also preferably in powder form, and more preferably one type of phenolic resin, melamine resin, or urea resin. Alternatively, it is easy to use a mixture of two or more types.Using a flame-retardant thermosetting resin as a binder will further improve the flame retardancy of wood products.Bromine-based flame retardants are suitable for thermosetting resins. Good types of flame retardants include TBA (tetrabromobisphenol A), HBB (hexabromobenzene), and TBP (brominated phenol), all of which mix well with thermosetting resins and provide good flame retardancy.For example, When 10 parts by weight of TBA was added to 100 parts by weight of phenolic resin, the flame retardant rating according to UL-94 was 5E-0.As described above, flame retardant cellulose powder and flame retardant powder A semi-non-flammable wood product was obtained by thoroughly mixing a thermosetting resin and molding the mixture under heat and pressure, and then coating the surface with a flame-retardant paint. There are various flame retardant paints, but Roof Blue (trade name of Dainippon Ink & Chemicals Co., Ltd.) was the most effective. Roofbruch is a room-temperature-curing flame-retardant paint that is applied by mixing an organic phosphorus-containing compound flame retardant (Roofbruf P) and a melamine resin fixing agent (Rufubruf FIX), and further mixing a curing accelerator (Catalyst X). As a result of coating the flame-retardant wood product of the present invention, it passed the first grade of the U L-723 fire protection test, which corresponds to the non-combustibility grade of general building materials in the United States. Also UL (UNDERWRITER3-LABORA
TORIES) I, A F D -S t
It also passed a fire test after 1,000 hours of accelerated weathering (equivalent to 3-5 years of actual outdoor exposure) using the D52, and received a provisional license from the Los Angeles Fire Department. The present invention has been completed by being able to obtain a non-combustible wood product as described above, but the wood product according to the present invention has secondary processability similar to that of wood, and further has various characteristics in terms of moldability. . The first point is that flame-retardant wood products can be molded directly from cellulose powder. Conventional flame-retardant wood products require the use of raw wood and expensive processing costs. However, the present invention can be applied to any material that is mainly composed of cellulose, such as hardboard punching m, sanding powder from plywood factories, sawdust from sawmills, or thinned wood from forests throughout the country that are in trouble because there is no effective way to use them. All of these can be used if they are pulverized, so the cost of materials is low, and the desired flame-retardant wood product can be obtained directly from the powder by molding a mold into the desired shape, so highly processed wood products can be used. Which price can be lowered. For example, expensive carved entrance doors, transoms, coffered ceilings, louvered doors, etc. can be produced at a fraction of the price of wooden products. The second point is that if a foaming agent is mixed in during molding and extrusion pultrusion molding or compression molding is performed, it is possible to produce wood products that are as light and flame-retardant as wood. The third point is that by extrusion pultrusion molding and continuous heating and pressure molding using multi-row rolls, long wood pipes, thin plates, and other flame-retardant long wood products with irregular cross sections that cannot be obtained with natural wood can be manufactured at low cost. That's a thing. Practical examples include shoji, fusuma,
Handrails, thresholds, lintels, wraparound edges, gables,
These include mounting brackets, wet edges, floor boards, ceiling boards, exterior wall materials, etc. The fourth point is that in order to make the surface natural wood, either a natural wood veneer pre-impregnated with flame retardant is attached to the product surface after molding, or the flame retardant veneer is fixed inside the mold. By insert molding, it is possible to easily and inexpensively produce a flame-retardant wood product with a natural wood veneer surface. Practical examples include entrance doors, partition boards, kitchen doors, and other furniture doors. The fifth point is that if the strength of the molded product is insufficient, a flame-retardant wood product with increased strength can be obtained by mixing and dispersing short pieces of non-combustible fiber such as glass fiber and carbon fiber when mixing the raw materials. . The sixth point is that when high strength is required, by inserting a metal pipe, metal plate, wire mesh, etc. into the mold as a reinforcing material and molding, it is possible to use a high-strength, flame-retardant wood material that is more reliable than wood. It is about getting the product. As a practical example, inserting wire mesh into the entrance door, metal angles into the window frames and windows, and square pipes into the pillars can provide sufficient strength as construction materials. The seventh point is the embossing method using a compression mold. In other words, if you carve wood grain, leather grain, cloth grain, etc. into a mold and perform compression molding, the desired uneven pattern will be created on the surface of the product. Flame-retardant wood products with wood grain patterns, leather stain patterns, etc. can be obtained at low prices.

[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 100b of wood flour finely ground to 40 mesh was put into a Henschel mixer, heated to 100°C by superheated steam connected to 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%. A moisture-proof flame retardant 10b according to Japanese Patent No. 782936 was added thereto, and the mixture was further heated and stirred for 10 minutes to obtain flame retardant wood powder uniformly impregnated with the flame retardant. In addition, a solution of 10 kg of urea resin initial condensate dissolved in 10-methanol was added.
When heated and stirred for 0 minutes, methanol was volatilized, and a powder in which urea resin was uniformly attached to flame-retardant wood flour was obtained. This powder (required amount) was put into a mold and heated to 180°C.
When compression molded at a pressure of b/cd, the carbon resin hardened in 5 minutes, yielding a wood product with 87% flame retardant wood powder using urea resin as a binder. J! conducted a flame retardant test on this flame retardant wood product. SΔ
-1321, it passed JIS flame retardant class 1. Flame-retardant wood products of any shape can be manufactured easily and at low cost by making a compression molding mold into a desired shape as needed. Example 2: 10 pieces of wood flour finely ground into 100 meshes were put into a Henschel 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 was dried to a moisture content of 5% or less in about 10 minutes. Moisture-proof flame retardant 15- according to Patent No. 782,936 was added thereto, and the mixture was further heated and stirred for 10 minutes to obtain flame retardant wood flour uniformly impregnated with the flame retardant. Phenol resin (resol), 10 kg methanol 4
After pouring the solution dissolved in 0b into the flame retardant wood powder mentioned above and mixing and diffusing it well, apply 2 to a glass fiber tape to impregnate it and heat and dry it to make a tape prepregged with phenol resin at the B-stage. As shown in Japanese Patent Application Laid-Open No. 51-58467, a hollow pipe is produced by wrapping it around a core metal, passing through a preheater, and then pulling it out through a hardening molding hot die together with the core metal. In this way, a long flame-retardant wood pipe was obtained. This woodwind was subjected to a flame retardant test according to JIS A-1321, and as a result, it passed JIS fi flame retardant grade 1. As described above, by making the shape of the prepreg and the shape of the drawing die into the desired cross-sectional shape, long flame-retardant wood products of the desired shape can be produced in large quantities at low cost. Example 3゜10 kg of phenolic resin (resol) was mixed with 10 kg of methanol.
-, then add TBA (tetrabromo bisphenol A) 1- as a flame retardant, mix well, add this to flame retardant wood powder JO5kf obtained in the same manner as in Example 2, and heat for 10 minutes. When stirred, the methanol was volatilized and a flame-retardant wood powder to which the flame-retardant phenol resin was uniformly adhered was obtained. This wood powder (required amount) is put into a compression mold in the shape of a door and fixed with a natural wood veneer whose surface has been pre-impregnated with flame retardant, and a wire mesh is inserted to tighten the mold. 18
By heating to 0° C. and compression molding at a pressure of 100 kg/c+J for 5 minutes, a door-shaped top panel with a high-strength flame-retardant layer on which a natural wood veneer was adhered and reinforced with wire mesh was obtained. The back plate was compression molded in the same way, the top plate and back plate were fitted and adhered, and the entire outer surface was brushed with Roof Bruf and cured at room temperature. This door is equivalent to the nonflammable grade of general building materials in the United States, and is UL-7.
It passes grade 1 of the 23 Fire Prevention Test and is ideal for entrance doors and interior doors in luxury condominiums. Example 4 100 pieces of hardboard punching waste pulverized into 80 mesh
- was put into a Henschel mixer and heated to 100°C by superheated steam passing through the jacket on the outer wall of the mixer and stirred for 3 minutes to remove water.
When 12 kt of a moisture-proof flame retardant No. 6 was added and the mixture was further heated and stirred for 10 minutes, a koji-combusted hardboard powder uniformly impregnated with the flame retardant was obtained. Separately, 10 kg of phenolic resin (Resol') and 1 kg of flame-retardant plasticizer cresyl diphenol phosphate.
Prepare a solution by dissolving the above in 20 kg of methanol, and then add the above! After adding the combustible hardboard powder and stirring and mixing it uniformly, 2 was coated on a glass fiber cloth to impregnate it, and heated and dried to make a sheet in which the phenol resin was bristle-rugged in the B-stage state. This sheet is passed through a preheating chamber and is sandwiched between stainless steel plates.
As shown in Section 4, Figure 3, a flame-retardant hardboard was obtained by feeding out the material while heating and pressurizing it with horizontal multiple rows of rolls. Furthermore, we coated the entire surface with roof proof and cured it at room temperature to obtain a non-combustible hardboard. This hardboard is UL-
It has passed the 1st grade of the 793 fire protection test and has been proven to be equivalent to the non-combustible grade of general building materials in the United States, so it is assumed that it will have many uses such as car interior cutting tools. It is the material. Example 5 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 describe a method for manufacturing flame-retardant shutters using this sander powder. 100% of sander powder was put into a Henschel mixer and heated to 100°C by superheated steam passing through the jacket on the outer wall of the mixer.
After heating and stirring for 5 minutes to remove moisture, the patent No. 78
Added 13 kg of moisture-proof flame retardant according to No. 2936 and added 1.
When the mixture was heated and stirred for 0 minutes, the flame retardant was uniformly impregnated into the sander powder to obtain flame-retardant sander powder. A solution of 10 kg of melamine resin (initial condensate) dissolved in 10 b of methanol was added to the above flame-retardant sander powder, and when the mixture was heated and stirred for an additional 10 minutes, the methanol was evaporated and flame-retardant sander powder to which the melamine resin was evenly adhered was obtained. . This powder (required amount) is put into a shutter mold, heated to 180° C., and heated and compressed at a pressure of 100 b/cd for 5 minutes. The mold for the shutter is etched with the wood grain transferred from natural wood on the front surface, and surrounding reinforcing bars and horizontal bars are provided on the back surface. The wood grain-like irregularities on the surface of the press-formed product are painted with a flame-retardant paint to seal the surface, and the color and texture of the irregularities are finished to resemble natural wood.After that, Roof Proof is applied to the entire surface and cured at room temperature. . The shutters made in this way have passed the UL-723 fire protection test grade 1, and are equivalent to the noncombustible grade of general building materials in the United States.
Traditionally, despite being a wooden building, metal sashes were unavoidably used for the shutters for fire prevention reasons, which did not blend in with the surrounding wooden structures and felt strange.However, with the present invention, it has been possible to finish the building in a color that blends in with the surroundings. It is fireproof, can be mass-produced, and is cheaper than metal sashes. Effects of the Invention According to the present invention, by making the powder of a substance mainly composed of cellulose flame retardant and molding it under heat and pressure using a thermosetting resin as a binder, a product with a high wood content and homogeneous flame retardancy can be obtained. It has become possible to supply flame-retardant wood products with high productivity at low prices, and waste materials mainly consisting of cellulose, which could not be effectively used in the past, can be made available to the world as useful flame-retardant wood products. The social significance of this is great.

Claims (13)

[Claims] (1) Substance 10 mainly composed of pre-pulverized cellulose
After uniformly coating and impregnating 1 to 30 parts by weight of a flame retardant to 0 parts by weight, 2 to 30 parts by weight of a thermosetting resin is added, and the mixture is uniformly mixed and then heated and pressure molded. A method for producing characteristically flame-retardant wood products. (2) The method for producing a flame-retardant wood product according to claim (1), wherein a flame retardant is blended in advance with the thermosetting resin. (3) A flame-retardant wood product molded under heat and pressure by the method described in claims (1) and (2). (4) Thermosetting resin is phenol resin, melamine resin,
The method for producing a flame-retardant wood product according to claim (1) or (2), which is one or a mixture of two or more urea resins. (5) Claim No. 1 (
A method for producing a flame-retardant foamed wood product according to item 1) or item 2. (6) A method for manufacturing a flame-retardant wood product according to claim (1), item 2 or claim (5), which comprises inserting metal parts during molding. (7) Manufacture of a flame-retardant wood product according to claim (1), item (2) or (5), which is formed by adding 1 to 20 parts by weight of chopped flame-retardant fibers and molding under heat and pressure. Method. (8) Claims (1), (2) or (5) in which flame retardant fibers in the form of a net or cloth are inserted during molding.
) The method for manufacturing the flame-retardant wood product described in section 2. (9) Claims (1) and (2) in which a natural wood veneer that has been pre-impregnated with a flame retardant and reinforced with a backing is attached after molding.
Section (3), Section (6), Section (7) or Section (8)
) The method for manufacturing the flame-retardant wood product described in section 2. (10) Claims (1), (2), and (5) in which a natural wood veneer that has been pre-impregnated with a flame retardant and reinforced with a backing is fixed in a mold and then heated and compression molded. ), Section (6)
A method for producing a flame-retardant wood product as described in paragraph (7) or paragraph (8). (11) Claims (1), (2), (
Section 5), Section (6), Section (7), Section (8), Section (9)
) or (10). (12) Claim No. 1 (1) in which the compression molding mold is engraved to form grains such as wood grain, leather grain, cloth grain, etc. on the surface of the molded product.
Paragraph 1), Paragraph (2), Paragraph (5), Paragraph (6), Paragraph (7)
), (8) or (11). (13) Claims (1) to (12) in which a flame-retardant paint is further applied to a flame-retardant wood product made by heating and pressurizing.
Flame-retardant wood products and their manufacturing method as described in Section 1.