JPS6255481B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing plywood having antiseptic properties. More specifically, one of the metal iodides in the adhesive
The present invention relates to a method for producing plywood having antiseptic properties by mixing at least one type of tributyltin compound selected from tributyltin laurate, tributyltin stearate, and tributyltin phthalate to produce plywood by a conventional method. In recent years, as the demand for wood in Japan has increased rapidly, domestic wood resources have not been able to keep up with the demand, and with the decline in resources, there are concerns that they will be depleted. and African materials are now being imported and used. Recently, in order to solve the housing shortage, streamlined construction methods aiming at lower costs, such as prefabricated construction methods that increase factory production rates, and two-by-four construction methods with high work efficiency, have been introduced and are being used frequently. With the advent of these new construction methods, the demand for plywood is increasing. These plywoods are mainly made of South Sea wood, which has not been used much in the past.
Compared to conventionally used wood, South Sea wood has many disadvantages such as being easily rotted, susceptible to mold growth, and susceptible to wood-eating insects. This drawback is a very troubling problem for plywood in general, and for structural plywood in particular, and must be solved urgently. In fact, recently there has been damage such as rotting plywood and being eaten by wood beetles. Therefore, in order to improve the durability of houses, it is essential to treat plywood to prevent rot and insects. In order to impart antiseptic and insect repellent properties to plywood, it is necessary to perform these chemical treatments, and methods include: (1) impregnating the veneer with chemicals and then gluing them together to create plywood; 2) A method in which a chemical is infiltrated into the finished plywood, or (3) a method in which a chemical is mixed into an adhesive to create plywood.
However, method (1) requires processing and drying equipment, workers, and time in addition to the existing plywood manufacturing equipment;
Manufacturing costs increase. Method (2) is undesirable because the chemical must be injected under pressure, which requires drying equipment, workers, and time, increasing costs and leaving negative effects such as deformation of the plywood and reduction in strength. . Method (3) can be carried out as is without changing the plywood manufacturing process, and the manufacturing cost is only the cost of chemicals, so it is the most desirable method.
Compared to methods (1) and (2), this method has drawbacks such as it is difficult for the chemical to penetrate the wood sufficiently, and therefore, the antiseptic and insect repellent effects cannot be fully exerted, and the adhesive strength is adversely affected. The present inventors have found that with method (3), that is, a method in which a preservative is mixed into the adhesive, the drug sufficiently penetrates into the wood and exerts its preservative effect without substantially reducing the adhesive strength. As a result of various studies on pharmaceutical compositions, we have found that adhesives contain one or more metal iodides and one or more tributyltin compounds selected from tributyltin laurate, tributyltin stearate, and tributyltin phthalate as active ingredients. The present inventors have come to the new finding that when plywood is produced by a conventional method with the addition of the compound, plywood with excellent antiseptic properties can be obtained, and the present invention has been completed. Metal iodides used in the present invention include sodium iodide, potassium iodide, lithium iodide, zinc iodide, calcium iodide, magnesium iodide, barium iodide, manganese iodide, iron iodide, and iodide. Examples include, but are not limited to, copper, tin iodide, and aluminum iodide. The mixing ratio of the drugs used in the present invention can be any ratio and can be varied. As a method for adding the agent of the present invention to an adhesive,
These drugs may be dissolved in a solvent beforehand and then added, or they may be added directly to the adhesive in its original form and mixed. As adhesives, adhesives that condense with formaldehyde are used, such as phenol/formalin resin, melamine/formalin resin, urea/formalin resin, urea/melamine/formalin resin, and resorcinol/formalin resin. 1 to 100 parts, preferably 2 to 50 parts, of the composition of the present invention is added and mixed per part, and plywood is prepared by applying an adhesive, laminating, cold pressing, standing, and hot pressing according to a conventional method. The chemical penetrates into the wood thoroughly without reducing adhesive strength, resulting in plywood with excellent antiseptic properties. Furthermore, there is no problem in mixing other preservatives, fungicides, insect repellents, penetrants, etc., and it is not only a preservative but also an anti-mold,
It enhances the insect repellent effect. Next, the effects of the present invention will be explained with reference to Examples. In addition, all numbers indicating proportions in the examples are parts by weight. Example 1 The chemicals listed in Table 1 were added to and mixed with 100 parts of phenol-formalin resin and 5 parts of wheat flour, and applied to a lauan veneer at a rate of 35 g per square meter (both sides).
5-ply plywood with a thickness of 1.5-3-3-3-1.5m/m was cold-pressed at 10Kg/ ^cm2 for 10 minutes and hot-pressed at a temperature of 140.
It was produced at a temperature of 10 Kg/cm ² at a pressure of 3 minutes under hot pressure. This plywood was cut in the center, and a coloring reagent (0.05% tricrine solution of diphenylthiocarbazone) was sprayed to determine the degree of penetration of the organotin compound in the drug at the cut surface. It was colored orange and its area ratio was measured. Also, the middle 2nd, 3rd,
The adhesive strength and wood breakage rate of the four layers were also measured. The results are shown in Table 1. Further, this plywood was cut into pieces of 3 x 3 cm and used as test pieces for a preservative test. In other words, JIS-
The test was conducted in accordance with the "Testing Method for Preservative Efficacy of Wood Preservatives" stipulated in A-9302. As the test bacteria, two types of wood-decaying fungi, P. japonica and C. versicolor, were cultured in a sea sand culture medium and used. The test piece was placed on the test bacteria and left to rot for 60 days at a temperature of 26±2°C and a relative humidity of 70% or higher. After decay, the test specimen was taken out, mycelia and other deposits on the surface were removed, dried, and weighed to determine the weight loss rate, and the efficacy value was determined by comparison with the untreated test specimen. The results are shown in Table 1.

[Table] Example 2 The drugs listed in Table 2 were added and mixed to 100 parts of urea/melamine/formalin resin, 12 parts of wheat flour, 10 parts of water, and 0.6 parts of ammonium chloride, and 35 g per square meter was mixed.
Apply to lauan veneer (both sides) at a rate of 1.5
-3-3-3-1.5m/m configuration, 5 ply plywood with cold pressure 10Kg/ ^cm2 for 10 minutes, hot pressure temperature 120℃, pressure 10
Kg/cm ² , and the heat-pressing time was 5 minutes. Using this plywood, the degree of penetration of the organotin compound, the adhesive strength and wood breakage rate in the three intermediate layers were measured in the same manner as in Example 1, and a preservative efficacy test was also conducted. These results are shown in Table 2.

【table】

[Table] As shown in the examples above, one or more metal iodides, which are the pharmaceutical composition of the present invention, and one or more specific tributyltin compounds are added to the adhesive,
It can be seen that by producing plywood using a conventional method, the chemical agent can sufficiently penetrate into the wood without reducing adhesive strength, and plywood with excellent antiseptic properties can be produced.

Claims (1)

[Claims] 1. Bonding the veneer with an adhesive that condenses with formaldehyde mixed with one or more metal iodides and one or more tributyltin compounds selected from tributyltin laurate, tributyltin stearate, and tributyltin phthalate. A method for producing preservative-treated plywood characterized by: