JP2553047B2 - Flameproof plywood - Google Patents

Description

The present invention relates to a flameproof plywood and a method for manufacturing the same. More specifically, the present invention relates to a flameproof plywood having the flameproofing performance specified by the Japanese Agricultural and Forestry Standards, and a manufacturing method thereof.

[Conventional technology]

Conventionally, the flameproof plywood is soaked in a flameproofing agent solution such as a mixed solution of monobasic ammonium phosphate and dibasic ammonium phosphate, impregnated with the flameproofing agent, and dried to obtain wood such as urea resin. What has been used is one which is adhered with an adhesive for use, or one which is obtained by impregnating the resulting ordinary plywood with the above flameproofing agent solution and drying.

[Problems to be solved by the invention]

However, in the production of these flameproof plywood, in addition to the veneer bonding step, a flameproofing agent impregnation step and a drying step are required, and the manufacturing process is complicated, and the equipment cost is high, resulting in a large product cost. Is affected. In addition, it takes a long time to produce the product, and the productivity is lowered accordingly, and the resulting product is inferior in appearance and water quality to ordinary plywood.

For such problems, a method for producing a flame-retardant plywood by adding a flame-retardant substance to an adhesive used for bonding single plates has been proposed (Japanese Patent Publication No. 17313/1985). However, the flame-retardant substance shown therein is not suitable for a product such as a flameproof plywood which requires low cost. Therefore, the present inventor conducted a study to add low-cost ammonium monobasic phosphate used in the conventional dipping method as a flameproofing agent to the wood adhesive. However, in order to add the first ammonium phosphate to the adhesive to form a flameproof plywood, the addition amount must be 10% by weight or more with respect to the adhesive, while the first ammonium phosphate is bonded to the other. The agent acts as a curing agent, and when it is added in an amount of 2% by weight or more with respect to the adhesive, curing and gelation of the adhesive rapidly proceed.
This is a very inconvenient problem in the production of plywood because the viscosity of the adhesive increases and the penetration into the veneer is insufficient.

[Means for solving problems]

The present inventor has completed the present invention as a result of intensive research to solve the above problems.

That is, the present invention is based on 100 parts by weight of the urea resin or the urea melamine copolymer resin, and the first ammonium phosphate of 5 to 1
5 to 60 parts by weight of melamine and / or melamine isomer
A flameproof plywood, characterized in that a flameproof adhesive containing 5 to 20 parts by weight of a mixture of fine alumina particles is contained between the veneers for plywood.

In the present invention, the monobasic ammonium phosphate has a performance as a flameproofing agent and also acts as a curing agent for an adhesive, but flameproofing can be achieved by adding a fine alumina particle mixture containing melamine and melamine isomers (melem, melam). The adhesiveness of the plywood can be improved by adding a relatively low amount of ammonium primary monobasic phosphate to the adhesive, preventing the adhesive from prematurely hardening and gelling, and applying the optimum viscosity necessary for applying to the veneer for plywood. It can be held for more than the required time in the manufacturing process.

The amount of the first ammonium phosphate is 5 to 15 parts by weight based on 100 parts by weight of the urea resin or the urea melamine copolymer resin. If it is less than 5 parts by weight, the flameproof property is lowered, and if it exceeds 15 parts by weight, the adhesiveness is lowered.

The amount of the alumina fine particle mixture is 5 to 20 parts by weight based on 100 parts by weight of the urea resin or the urea melamine resin. If it is less than 5 parts by weight, the flameproof property is lowered, and if it exceeds 20 parts by weight, the viscosity is increased and the workability is deteriorated. The alumina fine particle mixture contains 10 to 60% by weight of melamine and / or melamine isomer,
If it is less than 10% by weight, the flameproofness is insufficient, and if it exceeds 60% by weight, the viscosity increases and the workability is poor.

As the alumina fine particle mixture, for example, recovered catalyst fine particles by-produced from the urea-processed melamine-producing platon can also be preferably used. This is obtained by sieving the alumina catalyst recovered in the production of urea melamine, and the content of melamine and melamine isomers contained is 2% to 15% by weight of melamine, 5% to 40% of melam and melem. 1% to 10
%, But the degree of this component does not need to be so strict.

 The particle size of the fine particles is preferably 50 μm or less.

The mixture of primary ammonium phosphate and alumina fine particles is sufficiently dispersed and mixed in urea resin or urea melamine copolymer resin to form a flameproof plywood adhesive. In the manufacture of plywood, a flameproof adhesive is attached to the plywood veneer and laminated, and then 5
After applying a cold press of ~12Kg / cm ^2, sufficient with further 80 to 120 flameproof adhesive over hot pressing of 6~13Kg / cm ² under ℃ allowed to moderately immersion shaken during veneer bonding By doing so, a flameproof plywood is obtained.

〔The invention's effect〕

The flameproof plywood of the present invention does not require any impregnation and drying steps of the flameproofing agent as in the dipping method, and is of good quality only by adding a flameproofing adhesive adjusting operation to the ordinary plywood manufacturing process. And it is extremely advantageous in terms of cost. Further, a fine powdery recovery catalyst of urea-based melamine production punt can be used as a mixture of alumina fine particles, and further improvement in production cost can be expected.

〔Example〕

 Hereinafter, the present invention will be described specifically with reference to Examples.

Example 1 A 0.6 mm-thick lauan material was used as a front plate and a 1.3-mm-thick lauan material was used as a middle plate, and each flameproof adhesive composed of the component amounts shown in Table 1 below was used as a middle plate. 300 g per 1 square meter was applied on both sides, and the above-mentioned front plate was overlaid on and below it to produce a flameproof plywood under the adhesion conditions shown in Table 1 below. Table 1 shows the performance test results of the 2.5 mm flameproof plywood thus manufactured.

Example-2 Using a 0.6 mm-thick lauan material as a front plate and a 1.3-mm-thick lauan material as a middle plate, each flameproof adhesive composed of the components shown in Table 2 below was used as a middle plate. 300 g per 1 square meter was applied on both sides of the plate, and the above-mentioned front plate was overlaid on and below it to produce a flameproof plywood under the adhesion conditions shown in Table 2 below. The performance test results of the 2.5 mm flameproof plywood thus manufactured are shown in Table 2.

Claims (1)

(57) [Claims] 1. A urea resin or a urea melamine copolymer resin 10
5 to 15 parts by weight of primary ammonium phosphate and 10 to 60% by weight of melamine and / or melamine isomers per 0 parts by weight
A flameproof plywood, characterized in that a flameproof adhesive containing 5 to 20 parts by weight of the alumina fine particle mixture is contained between the veneer for plywood.