JP2633334B2 - Modified wood - Google Patents

Description

The present invention relates to an acetylated modified wood.

(Prior art and problems to be solved by the invention) Conventionally, in order to improve the dimensional stability and preservative and insect repellency of wood,
BACKGROUND ART Modified wood obtained by subjecting wood to acetylation treatment and substituting hydroxyl groups in wood components with acetyl groups is widely known.

However, since the above-mentioned modified wood is heated and washed in a treatment solution when the wood is acetylated, a part of the wood-extracting component such as resin is eluted from the wood cell wall, so that the teak, zelkova, rosewood, etc. Some of the so-called precious trees, such as cypress, cypress, and nara, have rough skin, poor tactile sensation, and lack of depth in the hand.

In addition, when acetylated wood is used around water, such as outdoors or in a bathroom, to achieve the dimensional stability and insect and corrosion resistance characteristics of acetylated wood, the acetylated wood is similar to untreated wood. Since the surface has irregularities peculiar to wood, there is a problem in that dust and the like easily adhere and become dirty, and germs easily propagate.

For this reason, it has been proposed to form a protective film on the surface of the acetylated wood, but there was a problem that the film was easily peeled off under the severe use conditions and the durability was poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a modified wood which has a good tactile sensation, a deep feeling, is hard to adhere to various germs, and has excellent stain resistance and durability.

(Means for Solving the Problems) In order to achieve the above object, the modified wood according to the present invention is obtained by subjecting wood to an acetylation-treated wood having an acetylation-treated layer at least on a surface layer. At least the surface layer of the acetylated wood is impregnated with an organopolysiloxane and cured.

The wood may have a shape such as a columnar body, a block-like body, or the like in addition to a veneer, a sawn board, or a plywood, an LVL, or the like obtained by laminating the wood as a material. .

The acetylation treatment can be carried out by reacting a hydroxyl group in a wood component with acetic anhydride, acetyl chloride, or the like with or without a catalyst.

When the acetylation treatment is performed in the presence of a catalyst, in order not to impair the cosmetic properties of the wood, for example, potassium acetate, sodium acetate, or the like is used as a catalyst, and the wood is impregnated with the catalyst and dried. And heated for a predetermined time, and chemically modified by contacting the hydroxyl group in the wood component with the acetyl group of the reaction solution, and then removing, washing, and drying the excess processing solution. Good. This way,
Depending on the reaction conditions, acetylated wood with a weight increase rate (hereinafter referred to as "acetylation rate") of 5 to 30% can be obtained.

The conditions for the acetylation treatment vary depending on the material, shape, size, etc. of the wood. However, in the case of a single veneer having a thickness of 1 to 10 mm, the reaction time is usually 100 to 150 ° C. and the reaction time is in the presence of a catalyst. Is preferably several minutes to several tens of minutes, and several minutes to several hours in the absence of a catalyst.

Further, the acetylated wood as it is, or
After cutting, polishing, and assembling as appropriate for the intended use, the surface is impregnated with an organopolysiloxane dissolved and diluted with a petroleum organic solvent such as triene or industrial gasoline at an appropriate concentration, and cured. The acetylated wood is preferably penetrated as dry as possible, and preferably has a water content of 5% or less. This is because the water in the wood does not hinder the penetration of a petroleum organic solvent described later.

The organopolysiloxane to be impregnated and cured has the general formula
Those represented by _{R 3 Si O (R 2 Si} O) Si R 3, represents wherein, R is an alkyl group, a least one of the aryl group, n is n
Represents an integer of ≧ 5. Representative examples of the alkyl group include a methyl group, an ethyl group, and a propyl group, and examples of the aryl group include a phenyl group.

And as typical organopolysiloxane,
A so-called silicone resin varnish obtained by dissolving a silicone resin having a three-dimensional network structure which is resinified by heating, particularly a silicone resin in an initial polymerization state, in a solvent is used. In addition, you may use what mixed the pigment as needed.

As described above, organopolysiloxane is used because it has a methyl group, a phenyl group and the like, and toluene,
Because it is soluble in petroleum organic solvents such as industrial gasoline,
This is because the organic solvent penetrates from the surface of the acetylated wood to which the organic solvent has easily penetrated by the acetylation treatment to the cell wall and hardens.

As a result, it is possible to supplement the extracted components in the wood cell wall that have disappeared by the acetylation treatment, smooth the skin, and improve the feel and texture.

As a method of infiltrating the organopolysiloxane into the acetylated wood, coating, dipping, or the like can be adopted. Application methods include spraying and brushing.
The immersion method includes known methods such as normal pressure immersion, reduced pressure immersion, and pressure immersion.

Although permeation amount depending on the depth to penetrate, without it preferably disappear wood texture and thick coating, 100 g / m ² or less, and more preferably is suitable 30~70g / m ^2. When a large amount is applied, it is preferable to remove excess organopolysiloxane from the surface by wiping.

The organopolysiloxane is, for example, from room temperature to
Dehydration reaction can be accelerated and cured at 150 ° C. Thereby, the polymer of the organopolysiloxane is firmly fixed inside the surface layer of the acetylated wood.

Example 2 mm thick, 300 mm wide, 300 mm long, dried cypress straight-grain veneer was poured with acetic anhydride by a vacuum method.
After immersion in an acetic anhydride bath at 125 ° C. for 60 minutes for acetylation treatment, washing and drying were performed to obtain an acetylation-treated veneer having an acetylation rate of 19%. Then, the acetylated veneer was made to have a water content of 3%, and a room temperature-curable organopolysiloxane (KC
−88 (trade name) 50% solid content manufactured by Shin-Etsu Silicone Co., Ltd.
A sample was obtained by brush coating at a rate of 70 g / m ² and curing for 1 day in a dryer at 40 ° C.

Comparative Example 1 An untreated, unpainted hinoki straight grain single veneer having the same outer dimensions as the example was used as a sample.

Comparative Example 2 An acetylated veneer obtained by subjecting a cypress straight grain single veneer having the same external dimensions as the example to acetylation under the same conditions as the example was used as a sample.

Comparative Example 3 A sample was prepared by infiltrating and curing the cold-curable organopolysiloxane under the same conditions as in the example into an untreated straight cedar veneer having the same external dimensions as the example.

The following tests were performed on each sample of the above-mentioned Example and Comparative Examples 1, 2, and 3.

Test Example 1 Blue ink was dropped on the surface of each sample, left to stand for 3 days, and then washed with water while rubbing the ink-adhered portion with a sponge, and the condition of ink drop was observed.

In Example 1, almost no dirt could be confirmed. In Comparative Examples 1 and 2, it was confirmed that the ink was partially spread, and in Comparative Example 3, it was confirmed that a round trace of the ink remained. Was.

Test Example 2 A brush of a washability machine specified in JIS-K5663 (synthetic resin emulsion paint) was rubbed back and forth 10,000 times on the surface of each sample. Observed.

In the examples, it was confirmed that traces of the ink remained slightly, whereas in the comparative examples 1, 2, and 3, it was confirmed that the ink was spread over the entire surface of the sample.

Test Example 3 Each sample was immersed in warm water at 40 ° C. for 3 months, and the surface change was observed.

In the example, there was little difference between the surface before the immersion and the extent that the mycelia slightly adhered to the surface. In contrast, Comparative Examples 1, 2,
In Fig. 3, it was confirmed that aqueous bacteria were attached to the entire surface of the sample located below the water surface, and in Comparative Example 3, it was confirmed that mycelia were partially impregnated.

As is clear from the above experimental results, the examples are comparative examples.
Stain resistance is better than 1,2,3.Especially, even after rubbing with a washability machine, the stain resistance is comparative example 1,2,3
, It was found that a beautiful appearance could be maintained for a long period of time.

It is considered that the durability of the modified wood was improved by the fact that the organopolysiloxane that had penetrated deeply from the surface of the acetylated wood and hardened firmly adhered to the acetylated wood and became difficult to peel off. .

Therefore, coupled with the fact that aqueous bacteria are difficult to adhere,
If the modified wood according to the present invention is used in a place such as a bathtub, a bathroom interior, or a sink where the water is easily contaminated, there is an advantage that an initial beautiful appearance can be maintained for a long time.

(Effects of the Invention) As is clear from the above description, according to the present invention, the polymer of organopolysiloxane that has penetrated from the surface layer of acetylated wood and has been cured in the wood cell wall during the acetylation treatment By supplementing the extracted components in the wood cell wall that has disappeared, the texture becomes smoother, the touch feeling is improved, and the texture of the surface is deeper.

Moreover, since many irregularities exposed on the surface are filled with the polymer of the organopolysiloxane, it is difficult for water to enter the interior of the acetylated wood, dust and the like do not adhere, and it is hard to be stained, Bacteria are difficult to propagate.

Since organopolysiloxanes are soluble in petroleum organic solvents that have a good affinity for acetylated wood, they penetrate deeply into the cell walls from the surface of the acetylated wood and firmly adhere to them. Under such conditions, peeling is more difficult than when a protective film is formed on the surface of acetylated wood as in the conventional example, and the durability is improved.

Claims (1)

(57) [Claims] 1. An acetylated wood having at least a surface layer having a general formula: R ₃ SiO ₂ (R ₂ SiO ₃ ) n Si R _{3 wherein} R represents at least one of an alkyl group and an aryl group; Is an integer of n ≧ 5. ] Modified wood characterized by being impregnated and cured with an organopolysiloxane represented by the following formula: