JPH02263603A - Manufacture of lumber treated with resin-impregnation - Google Patents

Abstract

PURPOSE:To obtain lumber treated with resin-impregnation which holds ligneous feeling, has plain wood tone in a needle-leaved tree by making light and shade of a summer-grained part and winter-grained part clear and has improved various such as water resistance, dimensional stability and hardness, by a method wherein unsaturated polyester and/or vinyl polymer and thermoplastic resin are used together at a specific ratio. CONSTITUTION:A resin solution comprised by adding 5-50 pts. vinyl acetate polymer degree of polymerization 20-1000 to a 100 pts. compounded solution comprised, for example, of an unsaturated polymer/styrene monomer is infiltrated into a Western hemlock veneer 0X1 under depressurization. Then an obtained resin-impregnated veneer is laminated onto a matter obtained by applying uniformly an adhesive agent to the surface of a lauan veneer board and clamped thermally.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a method for manufacturing plain wood-like resin-impregnated wood.
The present invention relates to a WPC improvement technique that can bring out the bare wood of the wood as much as possible, that is, maintain the white wood appearance, when R-combining to obtain a wood-plastic composite (WPC).

[Prior Art] and [Problem to be Solved] Wood grows by forming bark outward and xylem inward through the growth and division of parenchyma cells in the cambium layer (directly below the bark). The cells formed from spring to summer are large and soft, and the cells formed from late summer to autumn are small and hard.The former is called spring wood, and the latter is called autumn wood, and the annual rings are formed by the repetition of these processes.Coniferous wood. From the above, the spring wood is light in color and the autumn wood is dark in color to form the wood grain.

Decorative materials used for scale furniture, obi materials, etc. that make use of the grain of white wood are respected.

On the other hand, in order to give wood the properties of plastic and take advantage of the characteristics of wood while improving the shortcomings of wood such as shortcomings in dimensional stability, resin liquid was injected into the wood, and it was polymerized and cured at Murayama. WPC technology is also becoming more and more important.

W Conventionally, vinyl monomers such as unsaturated polyester, styrene, methyl methacrylate, vinyl acetate, acrylonitrile, etc. are generally used as the resin liquid in the ZePC, but resin impregnation is obtained by impregnating and curing the resin liquid. The treated wood has a wet color with increased transparency due to the resin (liquid), and it looks like it has been impregnated with plastic, so it is a raw wood that has been shaved white and has not been painted. It had the disadvantage of not being able to achieve the condition of a certain plain wood, and damaging the wood's texture.

Japanese Patent Application Laid-open No. 49-32924 describes the appearance of cypress pine, which is valued as a precious wood by taking advantage of the beautiful straight-grained wood grain pattern of the straight-grained coniferous boards. By press-fitting and curing a synthetic resin liquid with a light refractive index similar to that of the natural resin inside, the straight-grained thin boards of coniferous trees darken the normally light-colored spring wood, allowing the spring wood and fall wood to darken. It is described that the shading of the wood veneer is reversed to create a pine pattern appearance, and Japanese Patent Application Laid-Open No. 55-1:30715 describes a method to improve this by pressing a wooden veneer. A manufacturing method is described in which the synthetic resin is impregnated after tightening and then hardened. However, these techniques utilize the inversion phenomenon of wood [1] to improve the contrast of the wood grain. On the other hand, by using a resin composition containing a unique unsaturated polyester resin obtained by adding glycidyl acrylate etc. to the terminal carboxylic acid group of an unsaturated polyvarnish resin, and taking advantage of the fact that the unsaturated polyester resin whitens during curing, A method for manufacturing a decorative material with a different mechanism from the above technique has also been proposed (Japanese Patent Application Laid-open No. 107304/1983), which makes the boundary between the vernal and summer portions clear.

However, this publication cites general unsaturated polyester resins and epoxy resins to which acrylic acid or the like is added as being used in combination with the unsaturated polyester resins to form resin compositions.

That is, the resin composition contains a thermosetting synthetic resin.

In view of such prior art, the present invention uses a resin that can be made opaque or white after curing and is impregnated into wood and cured, thereby maintaining the wood texture and, in the case of coniferous wood, the summer grain (# grain) part. The shading of the folded eyes (winter 1) area has been made clearer. The purpose of the present invention is to provide a technique capable of obtaining resin-impregnated wood that has a plain wood look and has improved properties such as water resistance, crack resistance, dimensional stability, and hardness.

[Means for Solving the Problems] The present invention is characterized in that an unsaturated polyester and/or vinyl monomer is used in combination with a thermoplastic resin in a specific ratio. It is characterized by the combination of vinyl acetate-based polymers in a specific proportion.

Examples of the unsaturated polyester used in the present invention include unsaturated polyesters that can be prepared by, for example, 11N polymerization of an unsaturated dibasic acid and a polyhydric alcohol.

It may also be an ester octacondensate containing -1 part of a saturated dibasic acid or a copolymer with a vinyl group-containing compound (crosslinking agent).

Examples of unsaturated dibasic acids include maleic anhydride and fumaric acid. Examples of polyhydric alcohols include ethylene glycol and diethylene glycol. Examples of saturated dibasic acids include succinic acid and adipic acid. Examples of crosslinking agents include P-methylstyrene and diallyl phthalate.

Examples of the vinyl monomer used in the present invention include styrene, methyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, vinyl acetate, and acrylonitrile.

In item 1-, two or more types may be mixed, for example, a combination of unsaturated polyester, styrene/styrene and acrylonitrile: methyl methacrylate and 2-hydroxyethyl methacrylate.

As the thermoplastic resin used in combination with the unsaturated polyester and/or vinyl monomer, various types can be used as long as they can provide treated wood that becomes white or opaque after curing, but acetic acid It is preferable to use vinyl polymers, polystyrene, and acrylic polymers, and it is particularly preferable to use vinyl acetate polymers.

When used in combination, vinyl acetate polymers are effective when added to both these unsaturated polyesters and vinyl monomers, but polystyrene may not whiten compared to unsaturated polyesters, and its addition effect is more effective when added to vinyl monomers. Therefore, the combined use of vinyl monomers and polystyrene is recommended, and addition of acrylic polymers to unsaturated polyesters may only partially whiten.

In the present invention, by adding a thermoplastic resin, it is possible to create a plain wood look due to whitening.

In the present invention, it is also possible to improve the subsequent cracking property.

The ratio of the unsaturated polynisder and/or vinyl monomer to the thermoplastic resin is 100 parts by weight Qt of the former to 5 to 50 parts by weight of the latter, preferably 5 to 30 parts by weight, and less than SwL parts. 2. Transparency appears, which is insufficient to create a plain wood look.

When it exceeds 50vL, it becomes too white, and
This is undesirable as it causes the resin to become brittle.

As mentioned above, it is preferable to use a vinyl acetate polymer as the thermoplastic resin.

Examples of the vinyl acetate-based polymer include homopolymers of vinyl acetate having the following repeating tB position.

[However, n indicates the degree of polymerization] The degree of polymerization (average degree of polymerization) is 20 to 1000.

When the degree of polymerization is less than 20, the composition tends to remain transparent even when it is added, and is particularly transparent and difficult to whiten when acetic acid and nil monomer are used together.

The degree of polymerization! If it exceeds 00 ( ), the injectability into wood will be low.6 The vinyl acetate-based polymer may be a vinyl acetate copolymer such as a copolymer of vinyl acetate and ethylene.

The proportion of the vinyl acetate polymer used in combination with the unsaturated polyester and/or the vinyl monomer is 100% of the latter.
It is 5 to 50 wL parts, preferably 5 to 30 wt parts.If it is less than 5 wL parts, it will be too transparent and it will be difficult to achieve the desired purpose (effect) of the present invention, and if it exceeds 50 vt parts, it will be too white or , which tends to cause resin brittleness.

Polymerization initiators such as benzoyl peroxide, cyclohexanone peroxide, and L-butyl perbenzoate may be added to the resin liquid composition of the present invention, and other surfactants, pigments, and curing accelerators may be added as necessary. , plasticizers, thickeners, etc. can be added.

Furthermore, it can be appropriately diluted with an organic solvent.

In the present invention, wood includes various types of wood such as R11 temporary wood, hikisaka wood, veneer plywood, and particle boat.

It also includes a mode in which a surface material such as 11'L is pasted on a base plate such as plywood.

A known method can be used to impregnate wood with the resin liquid composition of the present invention and cure it. Impregnation can be carried out by, for example, normal pressure, reduced pressure, pressurization, or a combination thereof, and curing can be carried out by a chemical method such as thermal polymerization or by radiation polymerization.

The impregnated veneer is pasted onto the white base of plywood etc. using adhesive,
It is also possible to use means such as heat pressing and heat curing.

[Example] Next, the present invention will be explained based on examples.

Example 1 Vinyl acetate polymer 2 with a degree of polymerization of 300 was added to a liquid mixture consisting of unsaturated polyester/styrene monomer/benzoyl peroxide = 80/20/1 part (wL, same hereinafter).
Add 0 parts of the resin solution to the hemlock veneer (I x 30
0xl 800+wm) under a vacuum of 20 torr.

In addition, the unsaturated polyester is made of diethylene glycol of 2.2 mo R, maleic anhydride of 1 II lOQ, and 111
oQ is an unsaturated polyester resin with phthalic anhydride.

Next, apply water-based vinyl urethane adhesive evenly on the surface of the lauan plywood (12 g/90
0cm”) and was pasted on top of the material after 5 minutes of open deposition, heat and pressure conditions 120°C, 8 kg/
c111", and was hot pressed for 10 minutes.

1 Resin impregnation on smooth surface! The U board had a surface with a clear white wood tone in the summer and winter areas.

Comparative Example 1 A resin-impregnated veneer was obtained in the same manner as in Example 1, except that vinyl acetate polymer was not used, and heat-pressed.

1"Jim, it had an opaque surface condition in the winter part.

Example 2 Same as Example 1 except that 30 parts of polystyrene was added to 100 parts of methyl methacrylate,
A resin-impregnated veneer was obtained and hot pressed.

The resulting resin-impregnated veneer had a surface with a clear white wood tone in the summer and winter areas.

Example 3 A resin-impregnated veneer was obtained in the same manner as in Example 1, except that 30 parts of acrylic polymer was added to 100 parts by weight of unsaturated polyester, and hot pressed.

The resulting resin-impregnated veneer had a slightly weak degree of whitening, and the boundary between the second summer part and the winter part, and the sharpness of the shading were somewhat insufficient.

[Effects of the Invention] As described above, according to the present invention, the wood texture is maintained and the shading of the summer and winter parts of coniferous wood is clear, and the water resistance and dimensional stability as advantages of resin impregnation are achieved. The resin-impregnated veneer obtained by WPC technology, which has various properties such as hardness and hardness, has a transparent wet blue color and can be used in summer.

Claims (1)

[Claims] 1. A resin liquid composition prepared by adding 5 to 50 parts by weight of a thermoplastic resin to 100 parts by weight of an unsaturated polyester and/or vinyl monomer is impregnated into wood and hardened. A method for manufacturing plain wood-like resin-impregnated wood. 2. 5 to 5 parts of vinyl acetate homopolymer or vinyl acetate copolymer with a degree of polymerization of 20 to 1000 to 100 parts by weight of unsaturated polyester and/or vinyl monomer.
A method for producing plain wood-like resin-impregnated wood, which comprises impregnating and curing wood with a resin liquid composition containing 50 parts by weight.