JPH022401B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a method for coloring wood using an organic solvent. To explain in more detail,
The present invention uses a solution of a non-volatile dye and a polymer dissolved in a volatile organic solvent to uniformly impregnate wood with these dyes and polymers, and to recover the organic solvent with a high yield. The present invention relates to a method for coloring wood with an organic solvent, which is highly safe and economical. Background of the technology Wood has many properties that cannot be obtained from artificial wood.
For example, it has excellent workability, beautiful appearance, pleasant texture, and toughness, and is an extremely important material for human life. However, in recent years, the depletion of wood resources such as forests has become a worldwide concern, and for this reason, it is even considered that it is the duty of modern humans to use such wood with care. There is. A commonly used method for coloring wood is to mix a coloring agent (dye, pigment) of a desired color with a paint, such as paint or varnish, and apply the mixture. When coloring wood using such a coating method, the desired gloss cannot be obtained on the resulting colored surface, and the dimensional stability is unsatisfactory because the hygroscopic expansion property of the wood cannot be reduced.
Also, there are disadvantages such as insufficient strength of the paint film and easy peeling. In addition, with conventional painting methods, (1) only the surface of the material is colored and the interior cannot be colored, (2) the use of pigments makes it impossible to take advantage of the grain of the wood, and (3) the solvent used cannot be recovered. , (4) heating and fixing of the paint film may be necessary; and (5) there are problems of environmental pollution and high processing costs. Therefore, there has been a strong demand for the development of a new wood coloring method that eliminates the drawbacks of conventional paint coloring methods. OBJECT OF THE INVENTION The object of the present invention is to eliminate the drawbacks of the conventional paint coloring methods described above, to produce wood that has good gloss and desired color, does not peel off, is colored to the inside of the wood, and makes use of the wood grain. An object of the present invention is to provide an organic solvent coloring method. Another object of the present invention is to be able to reduce the processing expansion of wood and improve its dimensional stability;
Another object of the present invention is to provide a method for coloring wood with an organic solvent, which can improve the bending strength, compressive strength, and surface hardness of wood. Still another object of the present invention is to use organic solvents capable of dissolving the desired dyes and polymers.
Coloring wood safely and efficiently, and
The object of the present invention is to provide a method for coloring wood with an organic solvent, which can recover this organic solvent in high yield and does not pollute the environment. Structure of the Invention The method for coloring wood with an organic solvent according to the present invention includes the steps of: A) charging the wood into a closed impregnating can, and B sealing the impregnating can so as to impregnate the wood with a dye and a polymer. reducing the pressure and feeding a solution of a non-volatile dye and polymer dissolved in a volatile organic solvent into the impregnating can;
This solution is impregnated into the wood, D. The remaining solution is discharged from the impregnation can, E. The impregnation can is sealed again, and the pressure inside the can is reduced to vaporize and suction the organic solvent in the wood. pressurizing and compressing the aspirated organic solvent vapor to increase its temperature; liquefying the wood by cooling it to a temperature; H recovering the liquefied organic solvent; and I removing the treated wood from the impregnation can. In addition, in another method of organic solvent coloring of wood according to the present invention, in order to impregnate wood with a wood preservation agent, A) the wood is charged into a closed impregnating can, and B) the impregnating can is sealed and the can is heated. C A non-volatile dye dissolved in a volatile organic solvent,
introducing a solution with a polymer into the impregnating can to impregnate the wood; D draining the remaining solution from the impregnating can; E sealing the impregnating can again; F) The vacuumed organic solvent vapor is pressurized and compressed to increase its temperature; G-1 The compressed organic solvent vapor whose temperature has been increased is
liquefy it by cooling it to a temperature lower than its boiling point under the pressure, G-2 cooling the temperature of the liquefied organic solvent to a temperature lower than its boiling point under atmospheric pressure, H the liquefied organic solvent is recovered under atmospheric pressure,
and, I. taking out the treated wood from the impregnation can. DETAILED DESCRIPTION OF THE INVENTION The method of the present invention includes the steps of impregnating the interior of wood with a colored dye and polymer, fixing this, and efficiently recovering the organic solvent used for this impregnation. The dye used in the method of the present invention is not particularly limited as long as it can achieve the object of the present invention, but it is particularly preferable that the dye satisfies the following requirements. (a) Good light resistance and water resistance. (b) Able to penetrate into the interior of the wood and color it uniformly. (c) It must not lose its wood feel. (d) No special process or conditions are required for the fixation of the dye and polymer. (e) There shall be no adverse effects on the drying properties, paintability, adhesion, etc. of the wood. (f) Do not reduce the strength of the wood. It is preferable to select and use a dye that satisfies the above requirements, such as an oil-soluble dye. The polymer used together with the dye in the method of the present invention is not particularly limited as long as the object of the present invention can be achieved, but examples include polystyrene, polyvinyl ether, polyvinyl toluene, polyvinyl chloride, polymethacrylic acid and its esters, At least one selected from acrylic acid and its esters, polyvinyl acetate, polybutadiene, and copolymers of two or more of the corresponding monomers of the above polymers can be used. The organic solvent used in the method of the present invention is not particularly limited as long as it can dissolve the above-mentioned dye and polymer and is easily volatile. Such an organic solvent preferably has a boiling point of 110°C or less under atmospheric pressure, and more preferably a boiling point of 20 to 70°C. Organic solvents that can be used in the present invention include aliphatic hydrocarbons such as n-pentane, n-hexane, and n-heptane, such as methylene chloride,
halogenated hydrocarbons such as chloroform, trichloroethane, trichloroethylene, fluorinated hydrocarbons such as trifluorotrichloroethane, nitrites such as acetonitrile, ketones such as acetone, methyl ethyl ketone, etc.
Examples include ethers such as dioxane, and esters such as methyl formate and ethyl formate. The coloring treatment liquid used in the method of the present invention contains a dye in a volatile organic solvent at a desired concentration, preferably
The polymer may be added at a concentration of 0.1% to 5% (by weight), more preferably 0.5% to 2% (by weight), and the polymer may be added to a desired concentration, preferably 1% to 50% (by weight). concentration, more preferably 5%
Prepared by dissolving in concentrations ranging from to 40% (by weight). The method of the present invention will be explained in detail below with reference to the accompanying drawings. In FIG. 1, a closed impregnating can 1 has a lid 3 for charging and discharging wood 2 to be treated. The impregnation container 1 is made of stainless steel or the part that comes in contact with the liquid is made of stainless steel, and its size is set appropriately depending on the dimensions of the wood to be treated, and a plurality of pieces of wood 2 or a large number of pieces of wood 2 are charged inside. It may also be possible to process the This closed type impregnation can 1 is connected via a valve 4 to a solution tank 10 containing an organic solvent solution of wood coloring dye and polymer, and has a solution inlet 1a. It has a solution outlet 1b connected to the solution pump 11 via. The impregnating can 1 further has a steam outlet 1 c that communicates with a vacuum pump 9 for reducing pressure via a valve 7 . The solution pump 11 is connected to the processing solution tank 10 by a conduit.
is connected to. The vacuum pump 9 is connected to a vapor compressor 13 via a valve 12 and communicates with the atmosphere via a valve 8. Vapor compressor 13 is connected to vapor condensing device 14 . This steam condensing device 14 includes a cooler 14a
It is a compressed vapor that can be cooled to a temperature lower than its boiling point at atmospheric pressure and liquefied. The liquid outlet 14b of the vapor condensing device 14 is connected to the valve 1.
6, it communicates with a liquefied organic solvent recovery tank 15. As shown in FIG. 1, the recovery tank 15 is connected to the processing liquid tank 10 via an organic solvent pump 17.
may be connected to. Using the apparatus shown in FIG. 1, the method of the present invention is carried out as follows. First, open the lid 3, charge the wood 2 into the impregnation can 1, close the lid 3, and close the valves 4, 5, and 1.
2 is closed, valves 7 and 8 are opened, and the vacuum pump 9 is driven to reduce the pressure inside the impregnating can 1. The degree of vacuum inside the can at this time varies depending on the type, size, shape, etc. of the wood, but generally 60 mmHg (degree of vacuum) or less is sufficient. When the inside of the can is maintained at a certain degree of vacuum for a certain period of time, for example 10 to 30 minutes, the air inside the wood,
and volatile substances are removed. Next, valve 7 is closed, vacuum pump 9 is stopped, and valve 4 is closed.
is opened and the solution is introduced into the can from the processing liquid tank 10. After feeding a sufficient amount of treatment liquid into the can to fully immerse the wood, close the valve 4 and immerse the wood in the treatment liquid for a predetermined period of time, for example, 10 to 30 minutes. Immerse it inside. When the above impregnation operation is completed, open the valve 5,
The processing pump 11 is operated to return the remaining processing liquid in the can to the processing liquid tank 10. When this operation is completed, the pump 11 is stopped and the valve 5 is closed. Next, with valve 8 closed, valves 7 and 12 are opened to drive vacuum pump 9 and vapor compressor 13.
It also drives. Then, the pressure inside the impregnation can 1 is reduced, the boiling point of the volatile organic solvent in the wood is lowered, and the volatile organic solvent in the wood is easily evaporated. However, non-volatile dyes and polymers are retained within the wood without vaporizing. At this time, the initial temperature of the wood and solution is higher than the reduced boiling point of the organic solvent under reduced pressure, so that the latent heat of evaporation of the organic solvent is supplied from the heat possessed by the wood and the processing solution itself. do. For this purpose, the degree of vacuum inside the can should be adjusted to 100 mm depending on the type of organic solvent.
Hg or more, preferably 50 to 5 mmHg. The organic solvent vapor is sent from the pump 9 via the valve 12 to the vapor compressor 13, where it is compressed.
There is no limit to the pressure at this time, but it is generally 0.2 to 0.5
It is compressed until it exhibits a pressure of about Kg/cm ² G. As a result, the temperature of the compressed steam naturally increases. The temperature at this time is generally 30 to 50°C. Under such pressure, the boiling point of the organic solvent (the liquefaction temperature of vapor)
increases, so this compressed vapor can be liquefied by cooling it below its liquefaction temperature. Therefore, the pressure of the compressed steam is set so that the temperature of the compressed steam increased by this compression operation is higher than the temperature of the refrigerant (chilled water, etc.) used in the condensing device. Next, the compressed vapor is sent to the condensing device 14, where the compressed vapor is cooled to a temperature lower than the boiling point of the organic solvent (the liquefaction point of the vapor) under atmospheric pressure by the cooler 14a, and is liquefied. . By setting this cooling temperature lower than the boiling point of the organic solvent under atmospheric pressure, the liquefied organic solvent can be handled as it is under atmospheric pressure. The liquefied organic solvent is sent to the organic solvent recovery tank 15 from the discharge port 14b through the opened valve 16. The recovered organic solvent is pumped into pump 1 as necessary.
7 to the solution tank 10 and reused. Also, the treated wood is taken out from the impregnation can 1. In the condensing device, if the temperature of the liquefied organic solvent obtained by cooling and condensing the vapor is higher than the boiling point of the organic solvent under atmospheric pressure, as shown in FIG. , its outlet 1
4b and the liquefied organic solvent via the valve 16 to the cooling device 18, where the temperature of the organic solvent is adjusted to
Cool to a temperature below its boiling point at atmospheric pressure. In this way, the recovered organic solvent can be handled under atmospheric pressure. With the method of the invention, dyes and polymers penetrate into the interior of the wood, at least into the surface layer thereof, and are fixed within the wood by removal of the volatile organic solvent. Wood treated in this way is uniformly colored and develops a beautiful luster by simply buffing its surface. The present invention will be explained below by way of examples. Example 1 Five pieces of beech wood, each 5 cm square and 100 cm long, each having a moisture content of 18%, were placed in the impregnating can 1 of the apparatus shown in FIG. 1, and the lid 3 was closed and sealed. Close valves 4, 5, and 12, open valves 7, 8, and operate vacuum pump 9.
The pressure inside the can was reduced to 60 mm-Hg, and the air inside the can and the wood was exhausted for 30 minutes. Next, valve 7 was closed, valve 4 was opened, and the following composition had been prepared in advance in the treatment liquid tank 10: Methylene chloride 79% (weight) Polymethacrylate resin 20% (weight) (Dianal Resin BR-83, Mitsubishi) Rayon Co., Ltd.) paint (Varifu First Brown 3402, Orient Kogyo Co., Ltd.) 1% (by weight) of the treatment solution was introduced into the impregnation can, and after the can was filled with the solution, it was left to stand for about 30 minutes to coat the wood. The treatment liquid was infiltrated inside. The amount of treatment liquid injected at this time is 200 kg/
It was ^m3 . Next, valve 5 was opened and pump 11 was driven to return the excess treatment liquid to treatment liquid tank 10, and valves 4, 5 and 6 were closed. Next, valves 7 and 12 are opened, vacuum pump 9 and compressor 13 are driven, and the inside of the can is heated to 30 mmHg.
(degree of vacuum) to suck out the evaporated solvent, and
Pressurize to 0.5Kg/cm ² G with a compressor and raise the temperature to 43℃
This was cooled to 25° C. in the condenser 14 to liquefy it, and was recovered in the recovery tank 15. The working time up to this point was approximately 2 hours, and the recovery rate of methylene chloride at this time was 92.4%, and the moisture content of the wood after treatment was 15%. The treated wood was colored a medium-dark brown, and when the surface was buffed, it developed a beautiful luster. Example 2 A method similar to that described in Example 1 was carried out.
However, the composition of the treatment liquid was as follows. Trifluorotrichloroethane 91.5% (weight) Polybutyl methacrylate 7.5% (〃) (Vanaresin DR-1001, manufactured by Shin Nakamura Chemical Co., Ltd.) Dye (Varifu First Black 3820, manufactured by Orient Kogyo Co., Ltd.) 1% (〃) When the vacuumed organic solvent is pressurized by a compressor, the temperature rises to 35℃, and its cooling liquefaction temperature is 12℃.
It was warm at ℃. The resulting treated wood is colored black;
Good gloss was exhibited by buffing. Example 3 The same operation as in Example 1 was performed. However, the composition of the treatment liquid was as follows. Toluene 89% (by weight) Polystyrene 10% (〃) Dye (Varifu First Orange 3209, manufactured by Orient Industries) 1% (by weight) The obtained treated wood shows a beautiful orange color,
It showed good gloss due to buffing. Example 4 The physical property test results of the colored wood obtained in Examples 1 to 3 were as follows.

[Table] Effects of the Invention According to the present invention, wood can be uniformly and quickly colored to a desired color without using water. The coloration is robust and produces a good gloss due to surface buffing. What's more, the wood does not absorb water and swell during processing, and the dye and polymer penetrate into the wood and are fixed, improving the dimensional stability of the wood and improving mechanical properties such as surface hardness, bending strength, and compressive strength. can be significantly improved. Furthermore, in the method of the present invention, the organic solvent is recovered and recycled with high yield and efficiency, so it does not pollute the environment and the cost of coloring processing can be reduced. Furthermore, the method of the present invention does not require special heating for fixing the dye and polymer, and in this respect as well, the cost of coloring is low.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of the device of the present invention,
FIG. 2 is an explanatory diagram of another example of the apparatus of the present invention. 1... Impregnation can, 2... Wood, 9... Vacuum pump, 10
...Treatment liquid tank, 11...Solution pump, 13...Compressor, 14...Vapor condensing device, 15...Recovery organic solvent tank, 17...Recovery organic solvent pump, 18...Cooling device.

Claims (1)

[Claims] 1. In order to impregnate wood with a dye and a polymer, A. charging the wood into a closed impregnation can, B. sealing the impregnation can and reducing the pressure inside the can, and C. a volatile organic solvent. a non-volatile dye dissolved in
introducing a solution with a polymer into the impregnating can to impregnate the wood; D draining the remaining solution from the impregnating can; E sealing the impregnating can again; F) compressing the vacuumed organic solvent vapor under pressure to increase its temperature; liquefying the wood by cooling it to a temperature below its boiling point; H recovering the liquefied organic solvent under atmospheric pressure; and I removing the treated wood from the impregnation can. Organic solvent coloring method. 2. The method of claim 1, wherein the dye is selected from oil-soluble dyes. 3. The method of claim 1, wherein the concentration of the dye is in the range from 0.1% to 5% (by weight). 4. The method of claim 3, wherein the dye concentration is in the range from 0.5% to 2% (by weight). 5. The polymer contains two or more of polystyrene, polyvinyl ether, polyvinyltoluene, polyvinyl chloride, polymethacrylic acid and its esters, polyacrylic acid and its esters, polyvinyl acetate, polybutadiene, and corresponding monomers of the above polymers. The method according to claim 1, comprising at least one type selected from copolymers. 6. The method of claim 1, wherein the concentration of the polymer is in the range from 1% to 50% (by weight). 7. The method of claim 6, wherein the polymer concentration is in the range from 5% to 40% (by weight). 8. The method according to claim 1, wherein the organic solvent has a boiling point of 110°C or less at atmospheric pressure. 9 The boiling point of the organic solvent is 20 at atmospheric pressure.
9. A method according to claim 8, wherein the temperature is within the range of 70°C to 70°C. 10. In order to impregnate the wood with dyes and polymers, A) the wood is placed in a closed impregnation can, B) the impregnation can is sealed and the pressure inside the can is reduced, and C the non-volatile dye is dissolved in the volatile organic solution. and a polymer solution into the impregnating can,
This solution is impregnated into the wood, D. The remaining solution is discharged from the impregnation can, E. The impregnation can is sealed again, and the pressure inside the can is reduced to vaporize and suction the organic solvent in the wood. G-1 The compressed organic solvent vapor whose temperature has been increased is compressed under pressure to increase its temperature.
liquefy it by cooling it to a temperature lower than its boiling point under the pressure, G-2 cooling the temperature of the liquefied organic solvent to a temperature lower than its boiling point under atmospheric pressure, H the liquefied organic solvent is recovered under atmospheric pressure,
and (I) taking out the treated wood from the impregnating can. A method for coloring wood with an organic solvent.