JPH05154808A - Dimension-stabilized lumber or wooden material and its manufacture - Google Patents

Abstract

PURPOSE:To improve the dimensional stability of lumber or wooden material by impregnating the lumber or wooden material with the solution of N-methylol resins of two kinds having different numbers of hydroxyl group. CONSTITUTION:As N-methylol resin, at least one kind of dimethylol ethylene urea or dimethylol propylene urea and dimethylol dihydroxy ethylene urea are preferably used. These materials are used as aqueous solution, but alcohol, etc., may be added thereto. The emulsion such as zirconium salt or polyethylene- silicon as water-resistant agent, or polyethylene glycol or glycerin as humectant may be also added thereto. Lumber or wooden material is impregnated under reduced pressure with the aqueous solution in which e.g. magnesium chloride is added to the mixture as catalyst. When the materials are heated and are reacted with cellulostic OH group after drying, the dimensional stability of the lumber may be further improved than when each resin is used singly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimensional stabilization treatment method for wood and wood materials used for building interior materials and exterior materials.

[0002]

2. Description of the Related Art It is a well known fact that a method for obtaining dimensionally stabilized wood and wood materials by subjecting wood or wood materials (hereinafter simply referred to as wood) to etherification, acetylation, formalization, isocyanation, etc. It is known that a dimensional stabilization effect can be obtained. However, these conventional methods have high initial and running costs associated with equipment and their management and maintenance, are flammable depending on the solvent, and are safe for workers such as dermal or inhalation toxicity. A number of problems have been pointed out, such as the danger of the problem and the difficulty of recovering the solvent.

For this reason, it is common to use a water-soluble synthetic resin as the dimensional stabilizing agent. To do this, low molecular weight synthetic resins such as urea resin, melamine resin, and phenol resin are impregnated into wood by the dipping method or injection method,
A method of obtaining a dimensional stability effect by curing a resin is often used. However, the resin itself in the resin liquid is likely to polymerize, which shortens the pot life of the resin liquid in use, which makes it unsuitable for recycling.

[0004]

The performance required as the ideal resin property is that the OH group and the water molecule after the treatment absorb water and moisture by binding with the cellulose OH group in the wood cell wall. It is desired that the binding of the resin is inhibited to obtain a dimensional stability effect, that the resin itself hardly causes polymerization, the pot life is long, and the risk of flammability and safety is small.

[0005]

In order to solve the above problems, the present inventor has studied N-methylol resins used as shrink-proof agents and wrinkle-proof agents for cellulosic fibers such as cotton and vinylon. However, the N-methylol resin has a binding property with the cellulose OH group, the resin itself does not easily polymerize, the pot life is long, and there is little risk of flammability and safety because it is an aqueous solvent. It was found that it satisfies the processing requirements such as having the characteristics such as.

However, the use of N-methylol resin as a resin for wood injection has already been studied,
The results of injecting dimethylol ethylene urea, dimethylol propylene urea, and dimethylol dihydroxyethylene urea into wood have been reported (Nara Prefectural Wood Processing Material No. 18 (1989) P27-33). The conversion rates of methylol ethylene urea and dimethylol propylene urea into water-insoluble resin are 10% or less in the former and 0% in the latter, and it is reported that they cannot be used as a resin for wood injection.

[0007] The present inventor has studied the N-methylol resin mainly for dimensional stabilization of wood, and in spite of the above report, among the resins, dimethylol ethylene urea, dimethylol propylene urea,
By binding dimethyloldihydroxyethylene urea with OH groups in the amorphous regions of cellulose in the wood cell wall,
It has been found that a high dimensional stabilization of wood can be obtained. However, as a result of further examining each characteristic,
In the case of dimethylol ethylene urea and dimethylol propylene urea, in the dry water repeated test, high dimensional stability was shown at the initial stage, but the effect gradually decreased. At the stage, no significant dimensional stabilization was observed for wood, but we gradually grasped the characteristics of its effect.

It is recognized that these are based on the following reasons. That is, the cellulose molecule is represented by the following formula,

[Chemical 1] Dimethylol ethylene urea and dimethylol propylene urea have a high reactivity to C-6 of the cellulose OH groups and a low ratio of being involved in C-2, while dimethylol dihydroxyethylene urea is contrary to cellulose OH. This is because of the high reactivity of C-2 with respect to the group and the low ratio of participation with C-6. Therefore, by treating with at least one agent of dimethylol ethylene urea or dimethylol propylene urea and two agents of dimethylol dihydroxy ethylene urea, C-
6, it was found that the reactivity of C-2 with the cellulose OH group becomes high and a high dimensional stability effect due to synergism can be obtained. Further, from these facts, as the N-methylol-based resin, it is preferable to use a 5-membered or 6-membered cyclic compound having two hydroxyl groups (OH groups) and four compounds among the cyclic urea methylol compounds. I understood it.

The present invention has found that an effect which cannot be obtained by a single drug as a dimensional stabilization agent is obtained by combining two kinds of agents and a highly stable effect can be obtained by a synergistic effect. Accordingly, the method for stabilizing the dimension of wood according to the present invention is performed by using two different types of N-methylol-based resin liquids, particularly a 5- or 6-membered cyclic urea methylol compound having two hydroxyl groups (OH groups). The present invention is characterized in that wood is treated with a compounded resin liquid composed of four compounds.

As the method for impregnating the dimension stabilizing agent, there can be used a method conventionally used in the field of this type such as a dipping method, a pressure injection method and a coating method. For example, as an injection treatment method, a dipping treatment with a chemical is sufficient for a single plate such as a ground plate of 3 mm or less, slices, or rotary lace, but for a material of 3 mm or more, a known reduced pressure or reduced pressure application method is used. Combination is desirable. The treatment chemical is
Usually, a mixed drug of two kinds of drugs is used in advance, but it is also possible to impregnate one of the drugs and then to impregnate the other drug. In this case, the catalyst compounded in the treatment agent may be added to both, or may be added to either one. The catalyst may be a conventional N-methylol compound used in fiber treatment. For example, magnesium chloride and the like can be mentioned.

With respect to the compounding ratio of the treatment chemicals, the ratio of either dimethylolethylene urea or dimethylolpropyleneurea and the ratio of dimethyloldihydroxyethyleneurea in the solid content ratio is preferably 1: 1 to 1:10. The chemicals are used as an aqueous solution, but an organic solvent such as alcohol may be added if necessary for the purpose of facilitating impregnation. Basically, the higher the drug concentration is, the more stable the size can be obtained, but as the viscosity of the drug is increased, the permeability is deteriorated and it becomes difficult to uniformly inject the drug. Further, since the drying property becomes poor and the weight increases remarkably, productivity and product performance may be affected. Therefore, the main agent concentration is 10 to 50% aqueous solution in terms of solid content, and the optimum concentration is 20 to 35%.
Aqueous solution is good.

If necessary, additives to be used in this kind of field, auxiliary agents, colorants, preservatives, pesticides, etc. may be used in combination with the treatment agent as long as the performance of the main agent is not adversely affected. You can For example, by adding 0.2 to 5 parts of zirconium salt emulsion, polyethylene emulsion, or silicone emulsion as a water resistance / strength deterioration preventing agent in a solid content ratio to 100 parts of the compounded resin liquid, the weather resistance can be improved. it can. In addition, strength deterioration resistance can be imparted by adding 2 to 5 parts of polyethylene glycol and glycerin as a moisturizer / material strength deterioration preventing agent to 100 parts of the same mixed resin liquid.

[0013]

[Function] By mixing either or both of dimethylol ethylene urea or dimethylol propylene urea and dimethylol dihydroxyethylene urea,
Increases the ratio of binding with cellulose OH groups by a synergistic effect,
Excellent dimensional stabilization of wood is obtained by inhibiting binding with water molecules.

Further, dimensional stabilization can be further enhanced by adding a zirconium salt aqueous solution, a polyethylene aqueous solution, a silicone emulsion, polyethylene glycol and glycerin. Further, not only the dimension-stabilized wood and the dimension-stabilized wood material can be used as an exterior, but also insect repellent, antiseptic, and termiticide can be added by adding an insect repellent, antiseptic, or termiticide. Furthermore, it is possible to provide fireproofing performance by adding a fireproofing agent.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Example 1 Test material: Radiata pine grinding material Size: 500 (length 1) x 100 (width w) x 20 (thickness t)
mm Test agent Main agent: Dimethylol ethylene urea (solid content 50
%) 75 parts, dimethylol dihydroxyethylene urea (solid content 50%) 25 parts Catalyst: magnesium chloride aqueous solution (solid content 20%) The mixing ratio of the main agent and the catalyst is 20 parts of the catalyst to 100 parts of the main agent, 65 parts of water was added to 120 parts of the total amount of the main agent and the catalyst to prepare a 65% aqueous solution based on the apparent amount of the main agent + catalyst.
Zirconium salt emulsion as additive (solid content 20
%) Was added to 2 parts with respect to 100 parts of the above-mentioned mixed resin solution to give a mixed resin solution. After loading the test material in a pressure vessel, the mixed resin solution previously mixed was injected under a reduced pressure of 5 mmHg, and after 2 hours, the pressure was returned to normal pressure and left for 6 hours. Then, air-dry for 24 hours, and after drying at 40 ° C for 72 hours, cellulose OH
6 ° C at 80 ° C for 24 hours, then 100 ° C to react with groups
Heated for hours.

The dimensional-stabilized wood thus obtained was subjected to a repeated drying test. Test condition is 60 ℃,
After drying for 72 hours, it was immersed in normal temperature water for 72 hours, the shrinkage ratio at this time was obtained, and this test was repeated 10 times. In addition, in order to compare the shrinkage rates of untreated and treated materials, ASE (Antisw
elling efficiency) was used as an index. The formula of ASE is as follows. ASE (anti-swelling ability) = [(AB) / A] × 100 where A: volumetric shrinkage of untreated material B: volumetric shrinkage of treated material Table 1 shows the results.

Comparative Example 1 Test material: same as in Example 1 Test agent Main ingredient: Dimethylol ethylene urea (solid content 50
%) Catalyst: magnesium chloride aqueous solution (solid content 20%) The mixing ratio of the main agent and the catalyst was such that 20 parts of the catalyst was mixed with 100 parts of the main agent and water was added to make an aqueous solution of 65% with respect to the apparent amount. This compounded resin solution was injected into the test material and then heated to react with the cellulose OH group. Repeated dry water tests were carried out on the dimensionally stabilized treated wood thus obtained. The results are shown in Table 1.

Comparative Example 2 Test Material: Same as in Example 1 Test Agent Main ingredient: Dimethyloldihydroxyethyleneurea (solid content 50%) Catalyst: Magnesium chloride aqueous solution (solid content 20%) The mixing ratio of the main ingredient and the catalyst is 20 parts of the catalyst was mixed with 100 parts of the main agent, and water was added to make a 65% aqueous solution based on the apparent amount. This compounded resin solution was injected into the test material and then heated to react with the cellulose OH group. Repeated dry water tests were carried out on the dimensionally stabilized treated wood thus obtained. The results are shown in Table 1.

Example 2 Test material: same as in Example 1 Test agent Main ingredient: Dimethylol ethylene urea (solid content 50
%) 75 parts, dimethylol dihydroxyethylene urea (solid content 50%) 25 parts Catalyst: magnesium chloride aqueous solution (solid content 20%) The mixing ratio of the main agent and the catalyst is 20 parts of the catalyst to 100 parts of the main agent, Water was added to make a 65% aqueous solution based on the apparent amount. This compounded resin solution was injected into the test material and then heated to react with the cellulose OH group. Repeated dry water tests were carried out on the dimensionally stabilized treated wood thus obtained. The results are shown in Table 1.

[Table 1]

Example 3 Test material: Yonematsu rotary lace veneer Size: 300 (l) x 150 (w) x 2.0 (t) mm Test agent Main ingredient: Dimethylol propylene urea (solid content 50
%) 80 parts, dimethylol dihydroxyethylene urea (solid content 50%) 20 parts Catalyst: ammonium chloride (solid content 20%) The mixing ratio of the main agent and the catalyst is such that 25 parts of the catalyst is mixed with 100 parts of the main agent and water is added. Was added to make an aqueous solution of 60% relative to the apparent amount. The above test material was immersed in the mixed resin solution for 48 hours. Drying and curing were carried out by heating at 120 ° C. for 10 minutes in a dryer to react with cellulose OH groups. Ten sheets were laminated in the same direction by using a phenol resin adhesive for laminating the single plates by a conventional method. The dimension-stabilized wood material thus obtained was coated with an exterior alkyd paint. Table 2 shows the weather resistance test results of the obtained treated wood-based material exposed to the outdoors. Also,
Table 3 shows the results of the weather resistance acceleration test using a sunshine weather meter.

Comparative Example 3 Specimen: Same as Example 5 Size: 300 (l) × 150 (w) × 2.0 (t) mm Specimen: None As in Example 3, single plate lamination was performed by a conventional method. The wood material thus obtained was painted with an exterior alkyd paint. Table 2 shows the results of the weather resistance test of this test material by outdoor exposure. In addition, Table 3 shows the results of the weather resistance accelerating test using a sunshine weather meter.

[Table 2]

[Table 3]

[0022]

EFFECTS OF THE INVENTION The dimension-stabilized treated wood using two kinds of N-methylol resin as in Example 2 shown in Table 1 is
It can be seen that the dimensional stability effect is higher than that of the untreated material or the material treated with the N-methylol resin alone. This enhances the bondability between the cellulose OH group and the two types of N-methylol resins, and by the synergistic effect, the binding between the cellulose OH group and water molecules due to water absorption and moisture absorption after treatment is inhibited, and a dimensional stability effect is obtained. It is recognized that this is due to Further, as shown in Example 1 of Table 1, the dimension-stabilized treated wood impregnated with the mixed resin liquid obtained by adding the zirconium salt emulsion having the function as a water resistant agent to the two N-methylol resin blend liquids is It was found that there is a more dimensional stabilizing effect than the compounded resin liquid of two types of N-methylol resins shown in Example 4.

Further, as shown in Example 3 in Tables 2 and 3, in the weather resistance test and the weather resistance accelerated test, the dimension-stabilized wood material has higher weather resistance than the untreated material of Comparative Example 3. The following results were obtained. It is presumed that these results are based on the reasons given above and the simultaneous reasons. From these results, the dimensionally-stabilized wood and wood materials obtained by the present invention can be used not only as an exterior material, but also by adding an insect repellent, a preservative, or an anti-termite agent. , Ant-proof performance can also be added. on the other hand,
It is also possible to provide fireproofing performance by adding a fireproofing agent.

Claims (6)

[Claims] 1. A dimensional stabilization treatment method for wood and wood materials, which comprises impregnating wood or wood materials with a resin liquid of two kinds of N-methylol resins having different numbers of hydroxyl groups. 2. A wood or wood material is impregnated with a resin mixture containing at least one of dimethylol ethylene urea or dimethylol propylene urea and dimethylol dihydroxyethylene urea as two different N-methylol resins. The dimensional stabilization method according to claim 1, characterized in that 3. A mixed resin liquid obtained by adding a water resistant agent or a moisturizing agent to a mixed resin liquid of two different N-methylol resins is injected into wood or a wood material. The dimensional stabilization method according to item 2. 4. The dimensional stabilization treatment method according to claim 3, wherein a zirconium salt emulsion, polyethylene emulsion or silicone emulsion is added as a water resistant agent, or polyethylene glycol or glycerin is added as a moisturizing agent. 5. A dimension-stabilized wood material and a wood material, characterized in that a wood or wood material is impregnated with a resin solution containing two kinds of N-methylol resins having different numbers of hydroxyl groups. 6. Any one of claims 2 to 4
6. The method according to claim 5, wherein the processing is performed by the method according to claim 5.
Dimensionally stabilized wood and wood materials according to paragraph.