JPS61246003A - Manufacture of improved 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] This invention relates to a method for producing modified wood that imparts flame retardancy to wood.

[Background technology]

As non-combustible or flame-retardant materials, wood wool cement board,
There are light cal boards, cement boards, etc. These materials are made by mixing cement, which is a noncombustible material, with wood fibers and pulp as fillers, but although they are noncombustible, their bending strength, which is important for building materials, is significantly inferior to that of wood. There is. 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.

However, these methods have some problems. For example, diammonium phosphate and monoammonium phosphate decompose at low temperatures. Aqueous solutions in particular have this tendency, so they do not pass through high-temperature treatment during the manufacturing process of fireproofing materials, and they also serve as a food source for decaying bacteria, and as the amount of treatment increases, the antiseptic properties actually decrease. Also, potassium carbonate,
After treatment, sodium carbonate absorbs carbon dioxide gas in the air and becomes bicarbonate, which lacks stability over time. Calcium chloride and magnesium chloride have extremely high hygroscopic properties, encourage corrosion of metals and the growth of rotting fungi, and deteriorate wood quality. Zinc chloride is also highly hygroscopic. Also,
Some mixed systems of these drugs have the effect of compensating for each other's shortcomings, but in all cases, because they are water-soluble drugs, they have problems with water resistance and cannot be used as exterior materials, so their uses are limited. ing. Apart from these, organic chemicals such as organic salts are sometimes used, but there are still problems such as difficulty in handling due to the solvent etc. Therefore, there is a method in which a water-insoluble inorganic compound is dispersed in a solvent, the wood is soaked in this treatment solution, and the inorganic compound is impregnated with the solvent to the inner pores of the wood cells. The narrowest passage in the bit membrane in the cell wall pores is very small with a diameter of approximately 0.1 μm, making impregnation difficult.

[Purpose of the invention]

In view of the current situation, the present invention provides a modified wood that maintains the bending strength characteristic of wood and has flame retardancy.

[Disclosure of the invention]

In order to achieve this purpose, the inventors conducted extensive research and discovered that the solubility of water in the wood structure is 1, θ.
The following non-flammable inorganic compounds are 40% based on the absolute dry weight of wood.
It was discovered that water resistance and flame retardancy could not be maintained without these conditions, and after further research into a method for producing modified wood that satisfies these conditions, the present invention was completed.

Therefore, the present invention provides wood by impregnating wood with one aqueous solution of two water-soluble inorganic compound aqueous solutions that produce a desired insoluble nonflammable inorganic compound by mixing, and impregnating this wood with the other aqueous solution. The gist of this paper is a method for producing modified wood that allows insoluble, nonflammable inorganic compounds to be dispersed and fixed within the structure of wood. The present invention will be explained in detail below.

In the method for producing modified wood according to the present invention, of two water-soluble inorganic compound aqueous solutions A and H, which precipitate a water-insoluble, nonflammable inorganic compound when mixed, solution A is first prepared by a vacuum impregnation method. impregnate the inner pores of the wood tissue using methods such as Next, the wood impregnated with this liquid A is immersed in liquid B. The immersion time and treatment temperature can be changed as appropriate depending on the thickness and size of the wood and the amount of inorganic compound to be precipitated. Usually, the immersion time is 3 hours to several days, and the treatment temperature is 40 to 80°C. In this way, water-insoluble, nonflammable inorganic compounds are precipitated into the intracellular pores of the wood. Note that the order of impregnation with liquids A and B may be reversed, and both liquids A and B are not aqueous solutions of only one type of compound, but are aqueous solutions of a mixture of multiple types, or a plurality of aqueous solutions. It may be used in combination as a liquid or B liquid. The water-soluble inorganic compounds used in these solutions must each have a solubility of 5.0 or more in water so that the amount of precipitation of the insoluble inorganic compound is satisfied. Because the reaction occurs in the inner pores, Bitmenplan does not become an obstacle, and water-insoluble inorganic compounds can be dispersed and fixed in the inner pores of wood cells, resulting in modified wood with good flame retardancy. . The water-insoluble nonflammable inorganic compounds that precipitate include calcium carbonate, calcium phosphate, calcium hydroxide, calcium sulfate, calcium silicate, magnesium carbonate, magnesium phosphate, ammonium magnesium phosphate, magnesium silicate, aluminum hydroxide, and phosphorus. Examples include aluminum acid, aluminum silicate, barium carbonate, barium sulfate, and barium phosphate.

For example, when the insoluble nonflammable inorganic compound is calcium carbonate, the A solution is calcium bromide.

Calcium chloride, calcium chlorate, calcium nitrate,
Calcium nitrite, calcium chromate.

B liquids such as calcium acetate include ammonium carbonate, potassium carbonate, potassium hydrogen carbonate, sodium carbonate,
At least one of each of sodium hydrogen carbonate, potassium sodium carbonate, etc. is used.

In the case of calcium phosphate, the A liquid is the same as the calcium carbonate A liquid, and the B liquid is at least one of each of phosphoric acid, sodium phosphate, potassium phosphate, ammonium phosphate, etc.

In the case of calcium hydroxide, the A liquid is the same as the A liquid in the case of calcium carbonate, and the B liquid is at least one of each of sodium hydroxide, potassium hydroxide, ammonia, etc. In the case of calcium sulfate, As liquid A, the same as liquid A in the case of calcium carbonate,
B liquid includes aluminum sulfate, sodium sulfate, sodium hydrogen sulfate, potassium sulfate, potassium hydrogen sulfate,
At least one of each of magnesium sulfate, ammonium sulfate, sodium aluminum sulfate, potassium aluminum sulfate, ammonium aluminum sulfate, potassium magnesium sulfate, etc. is used.

In the case of calcium silicate, the A liquid is the same as the A liquid in the case of calcium carbonate, and the B liquid is at least 1 part each of sodium silicate, potassium silicate, etc.
Use seeds one by one.

In the case of magnesium carbonate, as the A liquid, at least one of magnesium chloride, magnesium sulfate, etc., and the same as the B liquid in the case of calcium carbonate, are used as the B liquid.

In the case of magnesium phosphate, at least one of the same liquid A as in the case of magnesium carbonate is used as the liquid A, and at least one liquid similar to the liquid B in the case of calcium phosphate is used as the liquid B.

In the case of magnesium hydroxide, at least one of the same liquid A is used as the liquid A for magnesium carbonate, and at least one liquid similar to the liquid B for calcium hydroxide is used as the liquid B.

In the case of ammonium magnesium phosphate, the A solution is the same as the A solution in the case of calcium phosphate, and the B solution is a silicone solution using at least one of each of a magnesium mixed solution (a mixed solution of magnesium chloride, ammonium chloride, and ammonia). In the case of magnesium acid, liquid A is the same as liquid A in the case of magnesium carbonate,
As the B liquid, at least one of the same liquids as the B liquid in the case of calcium silicate is used.

In the case of ammonium hydroxide, the A liquid includes aluminum chloride, aluminum bromide, aluminum iodide, aluminum nitrate, aluminum sulfate, etc., and the B liquid includes:
At least one of the same liquids as B in the case of calcium hydroxide is used.

In the case of aluminum phosphate, at least one of the same liquid A is used as the liquid A in the case of aluminum hydroxide, and at least one liquid similar to the liquid B in the case of calcium phosphate is used as the liquid B.

In the case of aluminum silicate, at least one of the same liquid A is used as the liquid A in the case of aluminum hydroxide, and at least one liquid similar to the liquid B in the case of calcium silicate is used as the liquid B.

In the case of barium carbonate, the A liquid includes barium chloride, barium bromide, barium iodide, barium nitrate, barium hydroxide, etc., and the B liquid includes B in the case of calcium carbonate.
Use at least one of the same materials as the liquid.

In the case of barium sulfate, the A liquid is the same as the A liquid in the case of barium carbonate, and the B liquid is the same as the B liquid in the case of calcium sulfate.

In the case of barium phosphate, the A liquid is the same as the A liquid in the case of barium carbonate, and the B liquid is the same as the B liquid in the case of calcium phosphate.
Use seeds one by one.

In this way, each desired insoluble, nonflammable inorganic compound is deposited in the intracellular pores of the wood.

Next, embodiments of the invention will be described in detail.

(Example 1) A saturated aqueous solution of sodium carbonate was prepared as liquid A, and a day-thick cedar veneer was immersed in liquid A to impregnate liquid A under reduced pressure. This veneer was immersed in a saturated aqueous solution of calcium chloride as liquid B heated to 50° C. and left as it was for 5 hours. Thereafter, this veneer was taken out and dried, and the weight increase rate was measured. JISA13 flame retardant test of this veneer
This was carried out using the method No. 21.

(Example 2) A flame retardancy test was conducted in the same manner as in Example 1, except that a saturated aqueous solution of potassium sodium carbonate was used as the A solution and the treatment time for the B solution was 7 hours.

(Example 3) A flame retardancy test was conducted in the same manner as in Example 1, except that a saturated aqueous solution of potassium carbonate was used as the A solution and the treatment time for the B solution was changed to 9 hours.

(Example 4) A flame retardancy test was conducted in the same manner as in Example 1, except that a saturated aqueous solution of ammonium carbonate was used as the A solution and a saturated calcium bromide aqueous solution was used as the B solution, and the treatment time was changed to 11 hours.

(Example 5) A flame retardancy test was conducted in the same manner as in Example 1 except that a 11111 cypress veneer was used and magnesium chloride was used as the B liquid.

The results of the examples are shown in Table 1.

As is clear from Table 1, all of the modified woods of the Examples had 40% by weight or more of nonflammable inorganic compounds dispersed and fixed therein, and exhibited good flame retardancy.

In addition, this modified wood has water-insoluble compounds fixed in its intracellular pores, so even if it is immersed in water again, these compounds will not be eluted (and its flame retardancy can be maintained stably). It can be used as an exterior wall material.The species of wood used is not limited to those in the examples, and any type of wood may be used.Also, the bending strength of general inorganic boards is approximately 100
kg/cm2, whereas the modified wood of the present invention exhibited a strength of about 1000 kg/cm2, which is 10 times stronger.

〔Effect of the invention〕

Since the method for producing modified wood of the present invention has such a structure, it is possible to obtain modified wood with excellent flame retardancy while maintaining the bending strength characteristic of wood.

Claims (3)

[Claims] (1) By impregnating wood with one aqueous solution of two water-soluble inorganic compound aqueous solutions that produce the desired insoluble nonflammable inorganic compound by mixing, and by impregnating this wood with the other aqueous solution, A method for producing modified wood in which insoluble, nonflammable inorganic compounds are dispersed and fixed. (2) The method for producing modified wood according to claim 1, wherein the insoluble, nonflammable inorganic compound has a solubility in water of 1.0 or less. (3) The method for producing modified wood according to claim 1 or 2, wherein the two water-soluble inorganic compounds each have a solubility in water of 5.0 or more.