JPH0880508A - Manufacture of modified lumber - Google Patents

Abstract

PURPOSE: To contrive improvements in dimensional stability, durability, an external appearance, by a method wherein a medical fluid produced by mixing an acrylic compound and cyclic ester compound with each other is infiltrated into lumber, which is heated and hardened. CONSTITUTION: A medical fluid is constituted by mixing methyl methacrylate and benzoyl peroxide as an acrylic compound and toluene of cyclic ester with each other and the medical fluid is infiltrated into lumber by a reduced pressure pressurizing method so that a degree of infiltration or nonvolatile content becomes 20%. Then the modified lumber is manufactured by heating and hardening within a hot air dryer at 120 deg.C. Therefore, irrespective of a low degree of infiltration, the modified lumber can be made into a matter wherein it is hard to crack and superior in dimensional stability, strength physical properties and since the degree of infiltration is low, an external appearance can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dimensional stabilization, durability and appearance improvement of wood or wood-based materials.

[0002]

2. Description of the Related Art Methacrylic acid ester has been conventionally used for wood,
A wood-plastic composite obtained by impregnating vinyl-based monomers and prepolymers such as styrene and unsaturated polyesters and polymerizing and curing in wood is called WPC and has dimensional stability, strength, durability and abrasion resistance. Its performance is widely recognized as a material with improved properties.

[0003]

However, these WPCs require a sufficient injection into the wood in order to impart sufficient dimensional stability, which not only adds to the cost of the treating agent but also increases the impregnation rate. With the increase, there was a drawback that the texture of wood tends to be lost.

Further, in order to solve such a problem, attempts have been made to combine a cyclic ester compound and wood with a low impregnation rate and a low cost, and excellent dimensional stability has been obtained. However, the cyclic ester compound alone swells the wood sufficiently, but softens it, lowers the surface hardness, easily causes scratches, and has little effect on improving strength.

[0005]

Means for Solving the Problems The present invention has been studied in order to solve the above-mentioned problems, and a wood or wood-based material is impregnated with a chemical solution in which an acrylic compound and a cyclic ester compound are mixed and cured. This improves the appearance of the wood without impairing the properties of the wood, and provides modified wood having excellent dimensional stability and strength. The present invention will be described below.

As the acrylic compound used in the present invention, one or more kinds are selected from acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, unsaturated polyester, styrene, and styrene derivative, and a polymerization initiator is selected. For example, persulfates, hydrogen peroxide, peroxides, azo-based polymerization initiators, redox-type redox polymerization initiators, etc., and those to which a polymerization accelerator such as amine or metal soap is added if necessary are applied. it can.

As the acrylic ester, an alkyl acrylate, a hydroxyalkyl acrylate, a diethylene glycol acrylate, a polyethylene glycol acrylate, a glycidyl acrylate, an ethylene glycol diacrylate, an ethoxyalkyl acrylate is used. Examples thereof include alkyl methacrylate, hydroxyalkyl methacrylate, glycidyl methacrylate and ethylene glycol.
Lumethacrylate, ethylene glycol dimethacrylate
And polyethylene glycol methacrylate, polyethylene glycol dimethacrylate alkyl: ethyl, methyl, pentyl, etc.). Examples of the styrene derivative include α-methylstyrene and p-methyl-α-methylstyrene. It is preferable to use methyl methacrylate which has good permeability and is easy to polymerize.

The cyclic ester compounds include compounds such as β-propiolactone, δ-valerolactone, ε-caprolactone, coumarin, tetrinic acid, pyrone and phthalide, and one or more of these derivatives. In order to select and proceed the reaction quickly and efficiently, alkali metal, alkali metal hydride, hydroxide,
Those to which a carbonate, an alkyl metal aliphatic amine, an acid, or a metal halide is added can be applied. It is preferable to use ε-caprolactone, which is advantageous in terms of cost and rich in reactivity.

It is desirable that the acrylic compound and the cyclic ester compound are mixed in a weight ratio of 1:99 to 99: 1. When the amount of cyclic ester compound is more than 1:99, the strength tends to be insufficient, and the acrylic compound is used. When the amount of the system compound is more than 99: 1, it becomes difficult to follow the change in the environment, the dimensional change becomes large, and cracks are likely to occur. It is in the range of 1: 5 to 5: 1 that it is excellent in anti-moisture ability, bending strength, and appearance (especially transparency and touch).

The chemical liquid can be used by diluting it by adding various compatible solvents to each treatment liquid in order to control the amount of adhesion to the wood. In this case, the solvent is reactive with the chemical liquid. Is preferably as low as possible, and specific examples thereof include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane, ethyl acetate, butyl acetate and the like. Ketones such as esters, acetone and methyl ethyl ketone,
Further, water, alcohols and the like can be mentioned, but the invention is not particularly limited thereto.

It is desirable to use an injection method from the viewpoint of permeating the chemical solution into the tissue of the wood, and for example, a dipping method, reduced pressure injection, pressure injection, or a method combining these injection methods can be applied. The impregnation rate of the chemical solution is preferably 10 to 30% in terms of non-volatile content in order to improve dimensional stability and strength without deteriorating the texture of wood. Here, the impregnation rate is obtained by dividing the adhesion amount of the chemical solution by the weight of the original wood and multiplying by 100, and is represented by the formula 1.

[0012]

[Formula 1] W = [(W ₂ −W ₁ ) / W ₁ ] × 100 (%) W: Impregnation rate W ₂ : Weight of wood after impregnation and drying W ₁ : Weight of original wood

Wood treated with the above chemical solution is heated with hot air,
It can be cured by heat treatment such as infrared heating, far infrared heating, radiation, ultraviolet rays, etc., and acrylic compounds and cyclic ester compounds are sufficiently cured at the heating temperature and heating time, etc., and wood is not damaged The conditions for the heat treatment may be somewhat different depending on the composition of the liquid chemical and the curing agent, but it is generally preferably 80 to 140 ° C. and 0.1 to 8 hours. Furthermore, it is possible to apply pressure simultaneously with heating using a flat plate press or a continuous press, and in this case,
The curing is promoted and the strength becomes excellent. Also as the pressure condition for applying pressure, it is desirable that the curing is promoted and the wood is not damaged, and the condition of 5 to ²⁰ kgf / cm ² is suitable.

Examples of wood and wood-based materials applicable to the present invention include lumber products, sliced veneers, laminated wood, particle boards, and the like. Specific examples include red oak, hippo, beech, lauan, poplar. , Hardwood such as capole, oak, zelkova, enoki, softwood such as cedar, pine, larch, and cypress, rubber laminated wood, LVL (Laminate)
d Veneer Number) and the like, and in terms of shape, a plate shape, a column shape, and the like can be exemplified, but the invention is not limited thereto.

[0015]

[Function] By impregnating wood with a chemical solution containing an acrylic compound and a cyclic ester compound as main components and curing it, the drawbacks of ordinary low-impregnated WPC are compensated, and the size is changed by a cyclic ester compound having a good affinity with wood. Effectively suppresses the shrinkage in the wood due to the polymerization of the acrylic compound and makes it difficult to crack.

Hereinafter, examples and comparative examples will be described in detail.

【Example】

Example 1 250 g of methyl methacrylate (syrupy form) as an acrylic compound, 2.5 g of benzoyl peroxide as a polymerization initiator, 250 g of ε-caprolactone as a cyclic ester compound, and 500 g of toluene as a solvent were mixed to prepare a chemical solution (A). Got Next, thickness 5mm, air-dry specific gravity 0.37
~ 0.42, fiber direction length 300mm, tangential direction 100
mm of cedar was impregnated with the chemical solution (A) by a pressure reduction and pressure method so that the impregnation rate became 20% in terms of nonvolatile content, and heated in a hot air dryer at 120 ° C. for 3 hours to obtain the modified wood of Example 1. It was

Example 2 300 g of polyethylene glycol monomethacrylate and 300 g of 2-hydroxyethyl methacrylate as an acrylic compound, 6.0 g of benzoyl peroxide as a polymerization initiator, and 200 g of ε-caprolactone as a cyclic ester compound. Then, 2.0 g of hydrochloric acid as a catalyst and 200 g of distilled water as a solvent were mixed to obtain a chemical solution (B). Then, the same cedar as in Example 1 was impregnated with the chemical solution (B) by a decompression method so that the impregnation rate was 20% in terms of nonvolatile content, and the mixture was heated in a hot air dryer at 120 ° C. for 3 hours. I got quality wood.

Example 3 Glycidyl methacrylate 30 as an acrylic compound
0 g and 300 g of styrene, 6.0 g of methyl ethyl ketone peroxide as a polymerization initiator, 6.0 g of cobalt octenoate as a catalyst, and 200 g of ε-caprolactone as a cyclic ester compound were mixed to obtain a chemical solution (C). Then, the same cedar as in Example 1 was impregnated with the chemical solution (C) by a pressure reduction method so that the impregnation rate became 20% in terms of nonvolatile content, air-dried, and then hot-pressed at 60 ° C. under a pressure of 5 kgf.
The modified wood of Example 3 was obtained by heating and pressing at / cm ² for 30 minutes.

Example 4 250 g of methyl methacrylate (syrupy) as an acrylic compound, 2.5 g of benzoyl peroxide as a polymerization initiator, 250 g of δ-valerolactone as a cyclic ester compound, and 500 g of toluene as a solvent were mixed. A chemical solution (D) was obtained. Then, the same cedar as in Example 1 was impregnated with the chemical solution (D) by a depressurization method so that the impregnation rate was 20% in terms of nonvolatile content, and heated in a hot-air dryer at 120 ° C. for 3 hours to obtain the product of Example 4. Modified wood was obtained.

Comparative Example 1 500 g of methyl methacrylate (syrupy form) as an acrylic compound without using a cyclic ester compound.
Was mixed with 500 g of styrene and 2.0 g of benzoyl peroxide as a polymerization initiator to obtain a treating agent (a). Then, the same cedar as in Example 1 was impregnated with the treatment agent (a) by a depressurization / pressurization method so that the impregnation rate was 20% in terms of nonvolatile content, and 120
The treated wood of Comparative Example 1 was obtained by heating in a hot air dryer at ℃ for 3 hours.

Comparative Example 2 300 g of methyl methacrylate (syrupy form) as an acrylic compound without using a cyclic ester compound.
An unsaturated polyester (500 g), styrene (200 g), benzoyl peroxide (6.0 g) as a polymerization initiator, and cobalt octylate (6.0 g) as a catalyst were mixed to obtain a treatment agent (b). Then, the same cedar as in Example 1 was impregnated with the treatment agent (b) by a depressurizing method so that the impregnation rate was 20% in terms of nonvolatile content, air-dried, and then hot-pressed at 60 ° C. and a pressure of 5 kg.
Heat-pressed at f / cm ² for 30 minutes to obtain treated wood of Comparative Example 2.

Comparative Example 3 Polyethylene glycol monomethacrylate 4 was used as an acrylic compound without using a cyclic ester compound.
00g and 2-hydroxyethyl methacrylate 600
g and 10 g of methyl ethyl ketone peroxide as a polymerization initiator were mixed to obtain a treating agent (c). Next, the same cedar as in Example 1 was impregnated with the treatment agent (c) by a pressure reduction and pressure method so that the impregnation rate was 20% in terms of nonvolatile content, and heated in a hot air dryer at 120 ° C. for 3 hours, and Comparative Example 3 Obtained treated wood.

Comparative Example 4 300 g of ε-caprolactone as a cyclic ester compound, 6 g of hydrochloric acid as a catalyst, and 700 g of water as a solvent were mixed without using an acrylic compound to prepare a treating agent (d).
Then, the same cedar as in Example 1 was impregnated with the treatment agent (d) by a depressurizing method so that the impregnation rate was 20% in terms of nonvolatile content. Then, the treated wood of Comparative Example 4 was obtained by heating in a hot air dryer at 120 ° C. for 3 hours.

The modified woods of Examples 1 to 4 and the treated woods of Comparative Examples 1 to 4 were evaluated for dimensional stability, hygroscopicity, bending strength and cracking. For dimensional stability and hygroscopicity, test specimens were tested at 40 ° C-30% RH, 40 ° C-
The mixture was allowed to stand in a thermo-hygrostat of 90% RH until equilibrium was performed, and anti-swelling ability (ASE) and anti-hygroscopicity (MEE) were measured. The bending strength was tested according to JIS Z2113.
About cracking, 80 based on JAS cold heat cycle A test
After leaving it in the incubator at ℃ for 2 hours, leave it in the incubator at -20 ℃ for 2 hours, repeat 5 cycles, and let it stand until it reaches room temperature, and check its appearance. And The evaluation results are shown in Table 1.

[0025]

[Table 1]

[0026]

EFFECT OF THE INVENTION Modified wood obtained by injecting a chemical solution containing an acrylic compound and a cyclic ester compound as a main component into wood and curing the wood is less likely to crack even though the impregnation rate is lower than that of conventional WPC. It has excellent dimensional stability and strength.

Further, since the impregnation rate of the chemical liquid is as low as 10 to 30%, the feel and appearance of wood are improved.

Claims (1)

[Claims] 1. A wood or wood material is impregnated with a chemical solution in which an acrylic compound and a cyclic ester compound are mixed,
A method for producing modified wood characterized by curing.