JPH03129213A - Kotatsu - Google Patents

Abstract

PURPOSE:To enable a kotatsu having a superior safety characteristic to be attained by a method wherein hydroxyl group in fiber is changed into acetyl while being kept at its aqueous fiber state, non-burned non-organic compound is fixed to or adhered to a fiber surface, in a cell hole and in an inner wall surface so as to form an improved wooden fibrous board integrally molded with adhering substance and then the board is applied as at least a part of a plate member. CONSTITUTION:Non-burned non-organic compound is fixed to adhered in a fiber cell and/or in an inner wall surface, an improved wooden fibrous board having non-burned non-organic compound fixed or adhered to an outer circumfer ence of wooden fiber is applied as an improved wooden fibrous board integrally molded with adhering substance. A frame wood, legs and at least a part of a plate member to which a kotatsu is fixed are formed. Accordingly, water and moisture are hardly absorbed, an expansion/shrinkage accompanying a variation of a moisture rate is scarcely generated and firing at the fixing part hardly occurs. With such an arrangement, it is possible to get a kotatsu having a superior safety characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to an electric kotatsu, and more particularly. Regarding highly safe electric kotatsu. [Prior art and highlights] Conventionally, most of the frame and one leg of an electric kotatsu were made of wood, and the heater unit and the board on which the hot air generator and heating element were attached were made of wood. something is being used. This is because wooden components have excellent heat resistance, so they do not soften due to the heat from the heating element, and they also have low thermal conductivity, making it difficult to warm up and cool down, so the temperature of the component does not rise, and the This is because it does not reach a temperature that makes the skin feel hot even when it comes in direct contact with the skin, and it also has properties such as being comfortable to the touch. However, since it is made of wood, it expands and contracts as its moisture content changes, causing problems such as gaps in the connections and warping.Furthermore, if you forget to turn off the switch, it may heat up for a long time. Case 1 The installation of the heating element was not completely satisfactory as there was a risk of fire starting from the parts. [Means to solve the problem] In view of the current situation, safety can be improved by using a wood material with excellent stability against changes in moisture content and non-combustibility, without sacrificing the advantages of conventional wood materials. As a result of extensive research in order to provide a kotatsu with high quality, we have finally completed the present invention. That is, the present invention provides a method in which a nonflammable inorganic compound is fixed or attached to the cell pores and/or the inner wall surface of the fiber, and the nonflammable inorganic compound is also fixed or attached to the outer periphery of the wood fiber. This kotatsu comprises at least a part of the board to which the frame, crosspieces, legs and heater unit of the kotatsu are attached, using an improved wood fiber board made by integrally molding improved wood fiber with an adhesive substance. In the improved wood fiber board, a nonflammable inorganic compound is fixed or attached to the cell pores and/or the inner wall surface of wood fibers in which hydroxyl groups present in the fibers have been acetylated. In addition, the kotatsu uses an improved wood fiber board in which improved wood fibers having the nonflammable inorganic compound fixed or attached to the outer periphery of the wood fibers are integrally molded with an adhesive substance. The wood fibers used in the present invention are, for example, fibers made of softwood such as pine, cedar, and cypress, or hardwood such as lauan, capor, chestnut, and poplar, which are made into chips and then defibrated according to a conventional method, and have a length of 1 -30m+a, thickness and diameter of 2-300μ account for the majority. This fiber has cell pores consisting of wood cells and conduit pores. It looks like a bundle of several to ten fibers, and the cell walls around the outer periphery of the fibers are often torn or have one crack. The improved wood fiber used in the present invention is first applied to voids such as cell pores and conduit pores of such wood fiber. Improved wood fibers having fire-retardant properties are obtained by fixing or adhering the non-combustible inorganic compound in a layered or packed form covering the pore walls. At this time, the weight ratio of the nonflammable inorganic compound to the weight ratio of the wood fiber is 3.
3% by weight or more is required. If the weight is less than 33%, the fire protection performance is insufficient and undesirable. Examples of nonflammable inorganic compounds used in the present invention include 1, for example, calcium compounds, magnesium compounds, aluminum compounds, barium compounds,
Examples include lead compounds, zinc compounds, and silicate compounds. Further, before the above-mentioned fireproofing treatment, the stability against water and moisture can be improved by acetylating the hydroxyl groups in the wood fibers according to a conventional method. It is possible to obtain wood fibers that have excellent fireproofing performance and dimensional stability. In order to produce the improved wood fibers that have been subjected to the acetylation treatment and fire protection treatment of the present invention, for example, in order to acetylate the hydroxyl groups in the wood fibers described above, the wood fibers may be treated without a catalyst or with a catalyst, for example. After impregnating with an aqueous solution of metal acetate such as sodium acetate or potassium acetate and drying,
The hydroxyl groups in the organic fibers are replaced with acetyl groups by immersing them in an acetic anhydride reaction solution such as anhydride@acid or chloroacetic anhydride and heating at 100-150 degrees Celsius for several minutes to several hours. After draining the reaction solution, wash and
dry. The acetylated wood fiber thus obtained is impregnated with the first liquid by mixing an aqueous solution of a water-soluble inorganic salt (hereinafter referred to as the first liquid), and then the wood fiber is dried and the surface of the wood fiber is In a dry state or in an absolutely dry state,
If necessary, after removing component crystals of the first liquid that have precipitated on the surface, add a compound liquid that reacts with the first liquid to produce a water-insoluble, nonflammable inorganic compound (hereinafter abbreviated as the second liquid). ) is added and mixed using a blender, spray, etc., to impregnate the second liquid, and the first liquid and second liquid react in the wood fiber, producing a nonflammable inorganic compound. Since it is water-insoluble, it is fixed or attached to the inside of the cell pore and/or the outer periphery of the fiber. Further, the efficiency of this reaction is improved if the second liquid is heated during addition and mixing, and is carried out under an atmosphere of 40° C. or more, preferably 50° C. or more. The improved wood fiber thus obtained is coated with a thermosetting adhesive such as a urea resin, a melamine resin, or a phenolic resin, a silent plastic adhesive such as a vinyl acetate resin, a rubber resin, or a two-component reactive resin. An improved wood fiber board is produced by adding a single adhesive or a combination of adhesives such as moisture-curing resin, adjusting the moisture content to tA, forming the mat, and compressing or thermally compressing it depending on the curing conditions of the adhesive. can do. This waste adhesive preferably has good permeability, and care must be taken to ensure that the adhesive strength is not reduced by the nonflammable inorganic compound that sticks or adheres to the surface of the improved wood nag. Further, it is preferable to add a flame retardant to the adhesive or to use an adhesive that has been made flame retardant in advance. The improved wood fiber board manufactured in this manner can constitute a board material to which the heater unit of the kotatsu is attached. In addition, when using the improved wood fiberboard as a component that requires strength, such as the frame, crosspieces, and legs of a kotatsu, after laminating several layers of the improved wood fiberboard using a urea-based or water-based vinyl urethane adhesive, hot A high-strength laminate is obtained by compression bonding by pressing or cold pressing, which is then cut to an appropriate radius and length, chamfered, and used. The surface of the improved wood fiber board is a smooth material that is stable against water and moisture, so 1) it has good surface cosmetic properties, and 2) it can be used for surface pasting of sheet-like decorative materials such as PVC sheets, veneers, and decorative paper; 2) surface painting and pressing. It is possible to use a material with arbitrary decoration such as overlay processing by molding or the like. [Effect] The kotatsu of the present invention acetylates the hydroxyl groups in the fibers in the state of wood fibers, and further acetylates the hydroxyl groups in the fibers as at least a part of the board material to which the frame, crosspieces, legs, and heater unit parts are attached. . By using an improved wood fiber board in which a non-combustible inorganic compound is fixed or adhered to the inside of the cell pores and the inner wall surface and is integrally molded with an adhesive substance, it is possible to prevent moisture and moisture without losing the advantages of conventional wood materials. There is little expansion/contraction caused by changes in moisture content, and there are no gaps or warping at the connections between parts. Even if the heating element in the heater unit heats up due to forgetting to turn it off, it is difficult to ignite from the installation, making this a highly safe kotatsu. (Example 1 Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 Radiata pine chips were heated at 160°C and weighed 7 kg/c+
++” for 3 minutes and defibrated using a defibrator refiner, the dried wood fibers were immersed in acetic anhydride and heated at 120°C for 1 hour. After the reaction was completed, they were immediately washed with water. Acetylated wood fibers were obtained by drying.At this time, the weight increase rate due to acetylation was 17%.Next, this acetylated wood fiber was immersed for 10 minutes in an aqueous solution containing barium chloride as the main component. After the diffusion treatment, the liquid was squeezed and dried with hot air to a moisture content of 7%, and then an aqueous solution containing ammonium phosphate as the main component was added and mixed in a blender to dissolve the inside of the cell pores and other areas of the wood fibers. / Or a nonflammable inorganic compound consisting of water-insoluble barium phosphate and barium hydrogen phosphate is produced on the outer periphery.Next, it is dried in a hot air drying room at 115°C to a moisture content of 7%.The weight increase rate due to this product is Using the improved wood fiber, 4% of a melamine resin adhesive containing ammonium phosphate was added. By hot pressing at 140°C for 6 minutes, l Omm/'X
got the board. Tomiyasu Honda used this board as a board material to install the heating unit of a kotatsu with 6 patents.

Claims (1)

[Scope of Claims] 1) A nonflammable inorganic compound is fixed or attached to the cell pores and/or the inner wall surface of the fiber, and the nonflammable inorganic compound is also fixed or attached to the outer periphery of the wood fiber. This kotatsu comprises at least a part of the board to which the kotatsu frame, crosspieces, legs, and heater unit are attached, using an improved wood fiber board in which the attached improved wood fibers are molded and integrated with an adhesive substance. 2) As an improved wood fiber board, a nonflammable inorganic compound is fixed or attached to the cell pores and/or the inner wall surface of wood fibers that have been treated to acetylate the hydroxyl groups present in the wood fibers, and 2. The kotatsu according to claim 1, wherein an improved wood fiber board in which improved wood fibers to which the noncombustible inorganic compound is fixed or adhered is integrally molded with an adhesive substance is used also on the outer peripheral part.