JPS6225007A - Manufacture of modified wood - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing modified wood that imparts flame retardancy to wood.

[Background technology]

Examples of non-combustible or flame-retardant materials include wood wool cement boards, light cal boards, and cement boards. These materials are made by mixing cement, which is a non-combustible material, with wood fibers, pulp, etc. as fillers, but although they can ensure non-combustibility, their bending strength, which is important for building materials, is significantly inferior to that of wood. ing. For this reason, the wood maintains its bending strength while maintaining flame retardancy (here, flame retardancy means that it decomposes thermally but does not ignite and burn; it is self-extinguishing). As a method of modifying water-soluble inorganic salts such as diammonium phosphate, diammonium phosphate, potassium carbonate, sodium carbonate, calcium chloride, magnesium chloride, zinc chloride, etc., either singly or in combination. There is also a method of impregnating the wood with it. The above-mentioned inorganic salts have been considered to have excellent fire prevention performance.

However, there are some problems with these. For example, diammonium phosphate and monoammonium phosphate decompose at low temperatures. This tendency is particularly strong in aqueous solutions, so they cannot be used at high temperatures during the manufacturing process of fireproof materials. Not only is it unsuitable for treatment, but it also serves as a food source for decaying bacteria, and as the amount of treatment increases, its antiseptic properties deteriorate.In addition, potassium carbonate and sodium carbonate absorb carbon dioxide gas from the air after treatment. , bicarbonate (hydrogen carbonate), which lacks stability over time. Calcium chloride and magnesium chloride have extremely high hygroscopic properties, promote corrosion of metals and the growth of rotting fungi, and deteriorate wood quality. Chloride Zinc is also highly hygroscopic.In addition, in a mixed system of these drugs, some have the effect of compensating for each other's shortcomings, but in all cases, since they are water-soluble drugs, there are problems with water resistance and the exterior packaging Its uses are limited, as it cannot be used as wood.Other than these, organic chemicals such as organic salts are sometimes used, but there are still problems, such as difficulties in collecting them due to the solvent etc. Therefore, by dispersing inorganic compounds that are insoluble in water into liquid,
There is a method of soaking wood in this treatment solution and impregnating this inorganic compound with the liquid up to the cell pores of the wood, but the narrowest passage when impregnating wood, the pores of the bit membrane in the cell wall pores, have a diameter of approximately It is extremely small at 0.1 μm and difficult to impregnate.

[Purpose of the invention]

This invention was made in view of the current situation, and aims to develop a manufacturing method that can obtain modified wood that has excellent water resistance and stable flame retardancy while maintaining the bending strength unique to wood. is intended to provide.

[Disclosure of the invention]

In order to achieve the above object, the present invention provides an aqueous solution of a water-soluble inorganic compound that reacts with carbon dioxide to produce a non-flammable inorganic compound that is insoluble in water. By impregnating the wood with
The gist of this invention is a method for producing modified wood in which the nonflammable inorganic compound is dispersed and fixed within the weave.

The present invention will be explained in detail below.

As mentioned above, in the method for producing modified wood according to the present invention, wood whose internal air has been replaced with carbon dioxide is used. Such wood can be obtained, for example, by placing the wood in a container that can be pressurized under reduced pressure, reducing the pressure in the container, and then filling the container with carbon dioxide, which is repeated a predetermined number of times.

The wood obtained as described above is impregnated with an aqueous solution of a water-soluble inorganic compound that reacts with carbon dioxide to produce a water-insoluble, nonflammable inorganic compound, and the solution penetrates into the intracellular pores in the wood tissue. Impregnation can be performed, for example, by soaking the wood in the aqueous solution and, if necessary, performing pressure impregnation. As a result, water-insoluble and nonflammable inorganic compounds are generated and dispersed in the intracellular pores.

According to this method, it becomes possible to disperse and fix a sufficient amount of nonflammable inorganic compound to impart flame retardancy to the intracellular pores of the wood without causing pit membrane plan to become an obstacle. And is it bad for water? Since the compound is fixed in the intracellular pores, it does not elute even when immersed in water, resulting in stable flame retardancy. The bending strength unique to wood is not impaired.

Examples of the water-insoluble nonflammable inorganic compounds produced include calcium carbonate and aluminum carbonate.

Examples of water-soluble inorganic compounds include calcium bromide, calcium iodide, and calcium chloride.

Examples include salts such as calcium chlorate, calcium nitrate, calcium nitrite, ammonium calcium sulfate, calcium acetate, sodium aluminate, potassium aluminate, and others. One type of these compounds may be used alone, a plurality of types of compounds may be mixed, or they may be used separately.

The amount of water-insoluble, nonflammable inorganic compounds in the wood is preferably 40% by weight or more based on the absolute dry weight of the wood. In addition, the solubility of nonflammable inorganic compounds in water is 1
．． It is better if it is 0 or less.

Next, this invention will be explained in detail.

(Example 1) First, an 11-thick cedar veneer was placed in a container that can be depressurized and pressurized, and after reducing the pressure inside the container, the process of filling the container with carbon dioxide was repeated 3 to 4 times. of air was replaced with carbon dioxide. Next, a saturated aqueous calcium chloride solution was introduced into the container and reacted for 24 hours. Through this treatment, modified wood with a weight increase rate (bone dry method) of 70 to 80% was obtained.

This modified wood had excellent flame retardancy.

In addition, the bending strength was approximately 1000 kg/cm'', which was approximately 10 times the strength of general inorganic boards.

(Example 2) Wood obtained in the same manner as in Example 1 was immersed in a saturated calcium chloride aqueous solution in a container as in Example 1. Then, pressure treatment was performed. Then, in one hour, Example 1
A similar effect was obtained.

That is, a modified wood with a weight increase rate of 70 to 80%, excellent flame retardancy, and a bending strength of about 1000 kg/cm2 was obtained.

(Example 3) Modified wood was produced in the same manner as in Example 1, except that a saturated calcium bromide aqueous solution was used instead of a saturated calcium chloride aqueous solution.

The obtained modified wood had a weight increase rate of 60 to 75%, and had excellent flame retardancy and bending strength unique to wood.

〔Effect of the invention〕

The method for producing modified wood according to the present invention involves impregnating wood whose internal air has been replaced with carbon dioxide with an aqueous solution of a water-soluble inorganic compound that reacts with carbon dioxide to produce a nonflammable inorganic compound that is insoluble in water. By doing so, the non-flammable inorganic compound is dispersed and fixed within the structure of the wood, thereby maintaining the bending strength peculiar to wood, and obtaining modified wood that has excellent water resistance and stable flame retardancy. Can be done.

Agent Patent Attorney Takehiko Matsumoto Procedural Amendment (Spontaneous October 9, 1985 1st Temple 1st Office Commissioner)
,,゜51,.

1. I■ Beef 4 Shiga Patent Application No. 164418 of 1985 2. Name of the invention Process for manufacturing modified wood 3. Relationship with the case of the person making the amendment Patent applicant Location Name of 1048 Kadoma, Kadoma City, Osaka Prefecture Name (583) Matsushita Electric Works Co., Ltd. Representative Iwantan Tei 4゜ Sadao Iwai No agent 6. Specification subject to amendment 7. Contents of amendment (1) Full text of the scope of claims column of the specification Correct as shown in the attached sheet.

(2) The words ``Pi-nodomenplan'' on page 4, line 6 to line 7 of page 4 and on page 5, line 19 of the specification are corrected to read ``pintomenplan.''

[Claims after amendment]

2. Claims (1) By impregnating wood whose internal air has been replaced with carbon dioxide with an aqueous solution of a water-soluble inorganic compound that reacts with carbon dioxide to produce a nonflammable inorganic compound that is insoluble in water. . A method for producing modified wood in which the nonflammable inorganic compound is dispersed and fixed within the structure of the wood.

(2) The amount of non-flammable inorganic compounds is 4% based on the absolute dry weight of the wood.
A method for producing modified wood according to claim 1, which is characterized in that the modified wood is dispersed and fixed in an amount of 0% by weight or more.

(3) The water-soluble inorganic compound was selected from the group consisting of calcium bromide, calcium iodide, calcium chloride, calcium chlorate, calcium nitrate, calcium nitrite, ammonium calcium sulfate, calcium acetate, sodium aluminate, and potassium aluminate. A method for producing at least one type of modified wood according to claim 1 or 2.

Claims (3)

[Claims] (1) By impregnating wood whose internal air has been replaced with carbon dioxide with an aqueous solution of a water-soluble inorganic compound that reacts with carbon dioxide to produce a nonflammable inorganic compound that is insoluble in water, the structure of the wood is A method for producing modified wood in which the nonflammable inorganic compound is dispersed and fixed. (2) The amount of non-flammable inorganic compounds is 4% based on the absolute dry weight of the wood.
Claim 1: Dispersion and fixation of 0% by weight or more
Method for producing modified wood as described in Section 1. (3) The water-soluble inorganic compound was selected from the group consisting of calcium bromide, calcium iodide, calcium chloride, calcium chlorate, calcium nitrate, calcium nitrite, ammonium calcium sulfate, calcium acetate, sodium aluminate, and potassium aluminate. A method for producing at least one type of modified wood according to claim 1 or 2.