JPH0686041B2 - Modified wood - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention has excellent dimensional stability, durability and appearance suitable for use as building exterior materials, bathroom wall materials, and other building materials. It relates to modified wood.

(Prior Art) Conventionally, a modified wood obtained by injecting and curing a synthetic resin liquid into a wood material has been widely known. Particularly, in order to improve dimensional stability and durability, a phenol resin is injected and cured. The modified wood thus obtained is used for building materials, furniture materials, etc., and effectively exhibits its characteristics.

(Problems to be Solved by the Invention) However, natural wood materials have dispersions of voids in cell walls and the like, and impurities that hinder the permeation of the treatment liquid, and the aqueous solution of the phenol resin. Despite having a suitable permeability to wood, its permeability is reduced due to the liquid quality and storage conditions of the phenolic resin, and uniform penetration into wood cannot be achieved. It was not possible to obtain a modified wood having uniform physical properties such as durability and dimensional stability as a whole.

Further, this resin-injected wood material has a problem that the surface thereof is darkened by the phenol resin, the appearance is remarkably impaired, and the cosmetic properties are poor.

Such deterioration is mainly due to the fact that the phenol resin is changed into a colored structure by ultraviolet rays or oxygen during the injection of the phenol resin aqueous solution into the wood material, the heat curing step, or during the use of this resin-injected wood material. It seems that there is.

The present invention has been made in view of such conventional problems,
It is an object of the present invention to provide a modified wood having a uniform appearance and a uniform appearance and a beautiful appearance.

(Means for Solving the Problems) In order to achieve the above object, the modified wood of the present invention is characterized in that a wood material is impregnated with an aqueous solution containing phenol resin and amine acetate as essential components and cured. It is what

(Function) Aqueous phenol resin solution to which amine acetate is added prevents coagulation and precipitation of the phenol resin by the amine acetate and promotes swelling of the wood material, thus increasing the swelling of the wood material. Whether it is wood or wood with uneven internal void density, it penetrates evenly and satisfactorily into the material during injection, resulting in uniform dimensional stability, durability, etc. It is possible to obtain a modified wood exhibiting the performance of.

In addition, phenolic resins in aqueous solution can be treated with amine acetates.
The pH changes toward neutral, and the darkening due to the phenolic resin itself does not progress easily, and it does not darken.In addition, the coloring component does not deteriorate even when exposed to the outdoors, and it becomes darker (colored). )
Is reduced, and a beautiful appearance is maintained for a long period of time.

(Examples) Next, the examples of the present invention will be described in detail. The modified wood is formed by impregnating the material with an aqueous solution containing phenol resin and amine acetate as essential components and curing the wood. .

As the wood material into which the mixed resin liquid as described above is injected,
Thick lumber products such as square lumber, plate lumber, hollow lumber, etc., and laminated lumber are used. However, even thin sheets such as veneer can be injected.

Further, as the synthetic resin to be injected, a phenolic resin that permeates the wood cell wall and is insoluble in the cell wall structure and forms an infusible substance is used, and this resin is used alone or mixed with a formalin resin, or It may be a co-condensation resin liquid.

Then, when the modified resin is produced, if the phenol resin is mixed with amine acetates and the mixed resin liquid is injected into the wood material, it is almost influenced by the difference in the wood species and the density variation. This is preferable because the mixed resin liquid penetrates deeply and uniformly into the cell walls of the wood material, and is not easily washed away outside the material in the solvent volatilization step described below, so that the fat content is improved.

It is considered that this is because the amine acetates increase the swelling of the wood material and facilitate the infiltration of the mixed resin liquid into the wood material.

In addition, amine acetates directly act on the phenol resin solution to prevent its discoloration (darkening) and aggregation, and in combination with the good permeability of the mixed resin solution into the above wood material, the appearance It is possible to easily obtain beautiful modified wood.

As the amine acetate mixed with the phenol resin, trans-1,2-cyclohexanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, 3,6-dioxa-1,8-octanediaminetetraacetic acid, N There are-(2-hydroxyethyl) ethylenediaminetriacetic acid, N- (2-hydroxyethyl) iminodiacetic acid, triethylenetetraminehexaacetic acid and the like.

The blending ratio of the amine acetates is preferably 0.1 to 20% with respect to the phenol resin (solid content), and the concentration of the mixed resin aqueous solution is selected to be 5 to 30%.

Next, the specific method for producing the modified wood will be described. First, the resin solution containing phenol resin and amine acetate as essential components is injected and impregnated into the wood material, and then the resin solution impregnation treatment is performed. A wood material is used alone or in the case of a thin plate, a plurality of wood materials are stacked and sandwiched between heating plates whose temperature can be adjusted up and down. At this time, in order to improve the productivity, it is preferable to stack and process a large number of wood materials sandwiched by heating plates.

In addition, it is desirable to provide a step of removing the solvent before heating and curing with a heating plate in order to carry out a homogeneous curing reaction. As such solvent removing means, reduced pressure drying, high frequency drying, and hot air drying are appropriately used in combination.

If such a solvent removal step is provided before heat-curing the wood material, the initial condensation reaction of the injected mixed resin liquid proceeds as the dehydration from the wood material progresses, and the resin component is contained in the fine voids of the wood material. Remains and is hard to flow out.

Next, we move to the heat curing process of resin-injected wood,
In this step, the temperature of the heating plate sandwiching the wood material is raised to 100 to 160 ° C. and the injected resin is reacted.
At this time, since the amine acetate is contained, thermal discoloration of the phenol resin can be suppressed.

In this heat-curing step, high-temperature heat treatment is performed while forced evacuation, and by the forced evacuation, volatile components and residual moisture such as formalin remaining in the wood material,
Also, the water generated by the condensation reaction of the resin is evaporated and reduced, and the injected mixed resin is cured by heating at high temperature.

The curing temperature of the injected resin is set within the above temperature range according to the type of the injected resin.

As described above, the reaction of the resin is completed by the step of evaporating the water in the wood material to remove the volatile components and the step of heating and heating the wood material.

In addition, in the final heat curing temperature (100 ° C. or higher), the drying step and the curing step, hot air or hot pressing may be subsequently used after releasing the reduced pressure.

Next, specific examples and comparative examples of the present invention will be shown.

(Example) Three types of veneer consisting of cedar, hippo, and maple with a thickness of 1.0 mm, a width of 100 mm, and a length of 200 mm were applied to a phenol resin (solid content 50%).
%) 10% and 0.1% ethylenediaminetetraacetic acid mixed resin aqueous solution is injected by a normal reduced pressure and pressure injection method, dried under reduced pressure, and then heat-cured at 160 ° C for 30 minutes. I got a plate.

All of the modified wood veneers thus obtained had no darkening, dullness, etc. on the surface layer and had a high yield without the need for sanding treatment for removing contamination.

(Comparative Example) 3 consisting of cedar, hippo and maple with the same dimensions as above
Only 10% of a phenolic resin (solid content 50%) was injected into the same type of veneer under the same conditions as in the above-mentioned example, and heat-cured.

The surface layers of all the modified wood veneers thus obtained were dark, and significant contamination was observed.

Next, the physical properties of the modified wood veneer obtained in the above Examples and Comparative Examples are shown.

In the above table, the dimensional stability is shown by the anti-shrinkage ratio (ASE) by the reduced pressure and pressure water absorption test.

As is clear from this table, the modified wood veneer in the examples of the present invention is excellent in dimensional stability and has a beautiful appearance without darkening.

(Effect) As described above, the modified wood according to the present invention is obtained by impregnating a wood material with an aqueous solution containing phenol resin and amine acetate as essential components and curing the wood material. When injecting a mixed resin solution with amines into a wood material, amine acetate can prevent coagulation and precipitation of the phenol resin, and the swelling of the wood material is increased to prevent impurities from penetrating the treatment solution. Even with a large amount of wood, or even wood with uneven internal void density, the resin liquid can be uniformly and satisfactorily penetrated into the wood, resulting in uniform dimensional stability. It is possible to provide modified wood having properties such as durability and durability.

In addition, the amine acetate prevents darkening of the modified wood due to the phenolic resin itself, and the modified wood does not deteriorate even when exposed outdoors, and the darkening is reduced. , It is possible to maintain a beautiful appearance for a long period of time.

Claims (1)

[Claims] 1. A modified wood material obtained by impregnating a wood material with an aqueous solution containing phenol resin and amine acetate as essential components and curing the wood material.