JPS6042008B2 - Manufacturing method for synthetic resin treated wood - Google Patents

Description

[Detailed description of the invention]
/ Re: 4 Toyo No. 4 Concerning the method of manufacturing Toyo P target lumber.

Wood is easy to obtain.

It is easy to work with, has low specific gravity, high strength, low thermal conductivity, high specific heat, and has good absorption performance for sound and mechanical vibration, etc., which cannot be obtained with other materials. It has unique properties. On the other hand, it has drawbacks such as warpage and distortion due to expansion and contraction due to moisture absorption and drying, and poor abrasion resistance.
Radicals such as styrene, methyl methacrylate, and unsaturated polyester have traditionally been used as a means of improving the expansion and contraction caused by the hygroscopicity of wood, giving it dimensional stability, and improving its abrasion resistance and strength. A method for producing synthetic resin-treated wood is known, in which wood is impregnated or coated with a polymerizable compound and then polymerized to improve the properties of the wood. Impregnation or coating with synthetic resins improves the properties of wood, such as strength, dimensional stability, abrasion resistance, and rot resistance, and also imparts secondary characteristics such as weight and aesthetics. However, a major drawback of synthetic resin-treated wood having these characteristics is that cracks occur due to aging, and the occurrence of cracks is further aggravated under conditions with large temperature differences. The occurrence of cracks is thought to be caused by an increase in internal stress in the wood due to impregnation or application of synthetic resin, and has traditionally been considered to be a fateful property of synthetic resin-treated wood. Until now, no method has been found to prevent this from occurring.

However, some attempts have been made to prevent the occurrence of cracks by reducing the amount of synthetic resin impregnated or applied to a small amount of about 10 to 2% by weight increase rate.
Although this method can prevent cracks to some extent,
Because the amount of synthetic resin impregnated or applied is small, the strength, dimensional stability, and abrasion resistance originally required of synthetic resin-treated wood are insufficient. The present inventors have conducted intensive research on a method for producing synthetic resin-treated wood that improves the above-mentioned drawbacks, and as a result, we have found that vinyl having polyoxyalkylene glycol chains in styrene derivatives, monoacrylic esters, or monomethacrylic esters has been developed. It was found that by impregnating wood with a treatment solution containing a series monomer and then curing it, the occurrence of cracks can be prevented without impairing the inherent properties of synthetic resin-treated wood. It was it.

That is, the present invention is based on the following general formula (where R is a hydrogen atom or a methyl group, m is an integer of 2 to 4, and n is an integer of 2 to 20.

) One or more selected from polyoxyalkylene glycol monoacrylate and polyoxyalkylene 5-glycol monomethacrylate shown in 30
40 to 7% by volume of one or more selected from styrene derivatives, monoacrylic esters other than formula [1], and monomethacrylic esters.
This is a method for producing synthetic resin-treated wood, which is characterized by impregnating wood with the three treatment solutions contained therein and then curing it. [1
] Compounds of the formula include acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypterobyl acrylate, 2-
Ethylene oxide, propylene oxide, butylene oxide,
It can be obtained by addition polymerizing one or more alkylene oxides such as tetrahydrofuran, or by esterifying acrylic acid or methacrylic acid with a polyalkylene glycol such as polyethylene glycol, polypropylene glycol, or polybutylene glycol. [1
] The reason why the number of moles of alkylene oxide added in the formula compound is limited to 2 to 20 moles is that if it exceeds 20 moles, [1]
Due to the high molecular weight of the formula compound), the impregnation rate into wood decreases and the effect cannot be expected when hardened, and furthermore, the strength and abrasion resistance decrease due to the plasticizer effect of the polyoxyalkylene glycol chain. By doing.

Further, if the number of moles of alkylene oxide added is less than 2 moles, it is insufficient and the ability to prevent rack generation cannot be achieved. Examples of styrene derivatives, monoacrylic esters and monomethacrylic esters other than formula [1] include:
Styrene, α-methylstyrene, p-methyl-α-methylstyrene, glycidyl acrylate, glycidyl methacrylate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2 -Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl meccrylate, trimethylolpropane monoacrylate, trimethylolpropane monomethacrylate, pentaerythritol monoacrylate, pentaerythritol monomethacrylate, and the like.

The content of the compound of formula [1] in the treatment solution to be impregnated into wood is 30 to 6% by weight, and if it is less than 3% by weight, the ability to prevent cracking is small, and if it exceeds 6% by weight, the ability to prevent cracking is poor. Despite our high expectations, we cannot expect the abrasion resistance and hardness required of synthetic resin treated wood.

In order to cure the treatment liquid containing 30 to 60% by weight of the compound of formula [1] impregnated into wood, the impregnated wood is heated to 50'C or higher to thermally polymerize the treatment liquid, or ionizing radiation, Although it is possible to polymerize and cure with electron beams, ultraviolet rays, etc., it is usually preferable to polymerize using a polymerization initiator.

Examples of the polymerization initiator used in this reaction include peroxides having the ability to polymerize vinyl groups and redox polymerization initiators that are a combination of peroxides and reducing agents. Furthermore, if necessary, it is also possible to add a known polymerization accelerator such as amine, metal soap, etc. for curing. The compound of the formula [I] used in the present invention is mixed with 6% of a 30-N compound and one or more monomers selected from styrene derivatives, acrylic esters and methacrylic esters other than those of the formula [I]. A treatment liquid containing 40 to 7% by weight can be applied to all kinds of wood, regardless of the type of wood or the form of the wood (timber, veneer, plywood, etc.).

The synthetic resin-treated wood obtained by the method of the present invention can be used as high-grade architectural wood, wood for exterior walls, flooring materials, materials for sports equipment, etc., which particularly require strength and no cracking.

The present invention will be explained below with reference to Examples.

Example [I] Wood was treated using a treatment solution containing the compound of formula [I] and a conventional treatment solution.

Table 1 shows the composition of the treatment liquid used.

Table 1: Preparation of synthetic resin treated wood specimens: The base wood is made of Yonematsu with a thickness of 0.6 mm, a specific gravity of 0.44 to 0.47, a length in the fiber direction of 30C7N1 and a length in the right angle direction of WO. A veneer was used.

This veneer was immersed in a treatment solution containing 1% organic peroxide (t-butylperoxy-2-ethylhexanoate) and the result was approximately 10k9/C. After impregnation treatment was carried out for 10 minutes under a pressure of 1 liter, the pressure was returned to normal pressure and the veneer was lifted out of the impregnating solution. After the impregnation liquid on the surface of the veneer stops dripping, wrap the veneer with aluminum foil and heat it at 100 °C for 3
A dust hardening treatment was performed. This synthetic resin-treated veneer was adhered to Lauan's Cuply plywood to which an area resin adhesive was evenly applied, and hot-pressed for 2 minutes at 120° C. and 10k9/Cli to prepare a test piece. Weight increase rate of synthetic resin treated veneer: Calculated using the following formula.

W1: Weight of untreated veneer W2: Weight of synthetic resin-treated veneer The prepared test pieces were subjected to a crack generation test, an abrasion test, and a hardness test.

Crack generation test: The length of the prepared test piece in the fiber direction is 5
The sample was cut into cm pieces and subjected to 3 cold/heat cycle tests.

That is, 2 bridges at -20℃, then 2 at 80 lines C0C.
The number of cycles until cracking was determined was determined by allowing one cycle to stand between the paper towels. Abrasion test: The prepared test piece was
0C77! ×10C77! The test was carried out using a Thebe abrasion tester using a piece cut to the size of .

The test results are expressed as the total abrasion loss of the test piece. Test conditions 1 Abrasion test paper: - S-33 Sand Vapor - 2 Load: 500 g on each side 1 Total load 1000 g 3 Number of wear: 500 times Hardness test: Using the prepared test piece cut into lengths in the fiber direction, JIS- The test was carried out according to Z-2117-63 wood hardness test method.

The test results show the average of three measurements. The test results are shown in Table 2.

Examination vagina. 8 to 10 (invention examples) are tests? ．． Compared to No. 1 to No. 7, each number of cycles until cracking is larger, indicating that cracks are less likely to occur. There is.

Total abrasion loss and hardness decrease are small, making it suitable for synthetic resin treated wood. Test Nos. 2 to 13, in which a large amount of the compound of the formula [1] was used, were less likely to cause cracks, but the total abrasion loss was large, making them unsuitable for use as synthetic resin-treated wood.

Claims (1)

[Claims] 1. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・〔I
] (wherein R is a hydrogen atom or a methyl group, m is an integer of 2 to 4, and n is an integer of 2 to 20.) selected from polyoxyalkylene glycol monoacrylate and polyoxyalkylene glycol monomethacrylate represented by 30 to 60% by weight of one or more monomers selected from styrene derivatives, monoacrylic esters and monomethacrylic esters other than formula [I], and 40 to 70% by weight of one or more monomers selected from 1. A method for producing synthetic resin-treated wood, which comprises impregnating wood with a treatment solution containing and then curing the wood. 2
The method for producing synthetic resin-treated wood according to claim 1, wherein the monomer selected from styrene derivatives, monoacrylic acids and monomethacrylic esters other than formula [I] is methyl acrylate, methyl methacrylate, or styrene. .