JP2002060272A - Method of manufacturing wood ceramic using plant-base liquefied material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing wood ceramic by using the liquefied materials obtained from plant-base raw materials and natural plant- base raw materials. SOLUTION: This method of manufacturing the wood ceramic consists in using the impregnation of the plant-base materials with the liquefied materials obtained from the plant-base raw materials and the firing of the same in an oxygen-free atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electrode substrate, for example,
The present invention relates to a method for producing wood ceramics using plant-based liquefied materials used for heaters, electromagnetic shielding materials, clutch plates, bearing materials, humidity sensors, temperature sensors, filters, far-infrared radiation aggregates for roads, and the like.

[0002]

2. Description of the Related Art Conventionally, wood ceramic, which is a kind of carbide of wood or woody material, has been used for electrode base materials, humidity sensors, temperature sensors, filters, far-infrared radiation aggregates for roads and the like. It is known that As a production method, wood, woody material, waste paper board and the like are impregnated with a petroleum-based phenolic resin and fired under oxygen-free condition. And
The present inventor previously conducted various studies to enhance the characteristics of wood ceramics and obtain a high yield, and as a result, impregnated and hardened wood chips or crushed pieces with phenol resin and then carbonized at high temperature. Hard carbon products that have the potential to be used in applications such as current-carrying materials, electromagnetic shielding materials in electronic equipment, aerospace materials, nuclear materials, etc. Wood ceramics) can be obtained in high yield (Japanese Patent No. 255257).
7). However, when producing a wood ceramic, impregnating with a petroleum-based phenol resin generates free formalin at the time of firing, which is not environmentally preferable.Moreover, when treating the wood ceramic thus obtained, more plant matter is required. There is a tendency for lack of waste treatment capacity to be able to use system waste.

On the other hand, various studies have been made to add a lignocellulosic substance such as wood to a phenol compound, mix and heat the wood to make it a liquefied product, and to use this as a raw material for plastics, fibers and adhesives. However, sufficient research has not yet been conducted on carbonizing this raw material and developing new uses. Under such circumstances, the wood liquefied product was impregnated into wood and woody material and fired, and it was found that a wood ceramic having excellent dimensional stability and electrical characteristics was obtained, and the present invention was completed. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing wood ceramics having excellent dimensional stability and electrical characteristics using a natural material as a raw material without using a petroleum-based phenol resin.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is a method for producing wood ceramics by impregnating a plant material with a liquefied substance obtained from the plant material and firing it in an oxygen-free atmosphere. The liquefied product obtained from the plant-based material is preferably a material obtained by mixing and heating a plant material and a phenol compound to liquefy wood flour. In the present invention, the material to be impregnated is a plant-based material, and the material to be impregnated is obtained from a plant-based material.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail. As the plant-based material that is the impregnated material used in the present invention, any of the raw materials used for wood ceramics can be used, and examples thereof include wood, woody materials, and used paper boards. The plant-based liquefied material used as the impregnating material is obtained by liquefying a plant-based material in the presence of a phenolic compound. The plant-based raw materials used here include wood, waste paper, pulp raw materials, rice bran, reed, esparto, jute, German linta, bamboo, hemp, straw, kenaf, sasa,
Any plant material such as bagasse, apple, rice, soybean and the like may be used. In the present invention, it is particularly preferable to use a paper material. That is, since the paper raw material is cellulose, it is very easily converted to a liquefied material, and has properties such as permeability when impregnated, so that it is suitable as a plant raw material. Examples of the phenol compound used when producing a liquefied product include phenol, o-cresol, m-cresol, 3,5-xylenol, 2,3-xylenol, catechol, resorcinol and the like. The liquefied product can be obtained by heating the plant-based material and the phenol compound in the presence of an acid catalyst such as sulfuric acid in a temperature range of about 200 ° C to 300 ° C, preferably about 250 ° C. The resulting liquid is in the form of a thermoplastic resin and is cured by cooling. Further, as the phenolic compound used for liquefying the plant-based raw material, wood vinegar oil containing the compound and alkali lignin recovered from pulp waste liquid can be used. Wood vinegar oil is obtained by vacuum distillation of wood tar obtained by carbonizing wood and the like, and mainly contains creosote. Also, if the flue gas or acid is added to the pulp waste liquid to lower the pH to 8.2, lignin will precipitate, so after heating, separate it, re-dissolve it in hot water and re-precipitate with hot dilute sulfuric acid. The resulting mixture is filtered, washed and obtained to obtain alkaline lignin, which contains a phenol compound. These are all phenolic compounds useful for liquefying plant-based materials. As an example,
As a liquefaction of wood using wood vinegar oil, 35 g of wood vinegar oil, 2.34 g of bamboo pulp, and 0.5 g of sulfuric acid are mixed and heated. After about 10 minutes, a wood liquefied product is obtained.

The resulting liquid is a viscous liquid which is thermoplastic and hardens when cooled. Therefore, when this is impregnated into a plant material, it is diluted with a solvent such as ethanol, for example. The dilution ratio of the wood liquefied product to ethanol is 2: 1 to 1: 1 by weight. An increase in the ethanol ratio of 1: 1 or more is not preferable due to cost problems. The impregnating means is not different from the conventional method for producing wood ceramics, and is performed by means such as injecting under reduced pressure using a vacuum pump or the like. The impregnation amount is 30 to 70% by weight based on the plant material. Wood, woody material, waste paper board, etc. impregnated with a liquefied material are pressed and clamped between upper and lower platens as a pressure forming means, and the pressing condition is 0.01 to 0.40 kgf / cm ² . Yes, and
The firing temperature is 400 in a non-oxidizing atmosphere.
２０００2000 ° C.

[0007]

Next, the present invention will be described more specifically with reference to examples.
In the present invention, as an example, a liquefied material obtained from a plant-based material is impregnated into a plant-based material, and a wood ceramic mainly composed of a so-called natural product obtained by carbonizing the plant-based material. , Characteristics. Example 1 A medium fiberboard (thickness: 14.7 mm, density: 0.58) made of hardwood as a plant-based material.
F) was impregnated with a plant liquefaction. The plant liquefaction used was produced by mixing wood flour and phenol at a ratio of 1: 3, adding 98% sulfuric acid to 4%, and heating at 250 ° C.
This is a dilution of wood liquefaction: ethanol = 1: 1. The impregnation was carried out by reducing the pressure in a vacuum desiccator for 10 minutes and then leaving it in a vacuum state for 2 hours. The obtained impregnated material was calcined and carbonized. Tokai Carbon Technology Co., Ltd. for calcined carbonization
Vacuum atmosphere with a compression-type wood ceramics charcoal unit,
400 ° C., 500 ° C., 650 ° C., and 800 ° C. under the conditions of a heating rate of 1 ° C./min and a holding time at the highest temperature of 2 hours.
The above four kinds of firing temperatures were set. This product is called A. For comparison, a petroleum-based phenol resin was impregnated with the above-mentioned plant-based liquefied product, and exactly the same operation was performed. This product is called B. The same operation was performed without impregnating any compound or resin to obtain a product. This is C
That. A: According to the present invention (wood ceramics in which a medium fiberboard is impregnated with a plant-based liquefied substance B: Conventional products (wood ceramics in which a medium fiberboard is impregnated with a petroleum phenolic resin C: carbide (medium fiber Properties obtained by sintering the plate without impregnation) The properties compared are the dimensional shrinkage in the planar direction, the dimensional shrinkage in the thickness direction, the residual weight, the change in density, the compressive strength, the volume resistivity, and the specific surface area.

[0008]

[Table 1]

[Table 2]

[0009]

[Table 3]

[Table 4]

[0010]

[Table 5]

[Table 6]

[0011]

[Table 7] The results of the above five-step evaluation are as follows.

[0012]

[Table 8]

With respect to the obtained products A and C, the dimensions, weight change, compression test, and specific volume resistivity are shown in the figure.

Example 2 A product was produced in the same manner as in Example 1 except that the ratio of the liquefied wood to ethanol (diluent) was 2: 1. Since the obtained product had foaming marks on the surface, the dimensions, compressive strength, and the like were not measured.

[0015]

As described above, in the present invention, a plant-based material is used, and wood ceramics obtained by impregnating and sintering a plant liquefied product obtained from a plant-based material are used. It can be said to be an ecological product, and the obtained product has characteristics comparable to those of conventional wood ceramics.

[Brief description of the drawings]

FIG. 1 shows the relationship between the firing temperature and the shrinkage in the length direction.

FIG. 2 shows the relationship between the firing temperature and the shrinkage ratio in the width direction.

FIG. 3 shows the relationship between firing temperature and shrinkage in the thickness direction.

FIG. 4 shows the relationship between the firing temperature and the residual carbon ratio.

FIG. 5 shows the relationship between firing temperature and density.

FIG. 6 shows the relationship between firing temperature and compressive strength.

FIG. 7 shows the relationship between firing temperature and volume specific resistivity.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Yoshimura 1-6-12 Teraonaka, Ayase-shi, Kanagawa F-term (reference) 2B230 AA30 BA01 CB02 CB06 EA20 EB02 EB05 4G032 AA01 BA02 BA04 BA05 GA12 4G046 CA04 CB01 CB08 CC02

Claims (2)

[Claims] 1. A method for producing wood ceramics, comprising impregnating a liquefied material obtained from a plant material with the plant material and firing the material in an oxygen-free atmosphere. 2. The method for producing wood ceramics according to claim 1, wherein the liquefied product obtained from the plant material is liquefied by mixing and heating a plant material and a phenol compound.