JPH0623366B2 - Adhesive composition for flameproof plywood - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an adhesive composition for flameproof plywood. More specifically, the present invention relates to an adhesive composition that is useful in the production of flameproof plywood that complies with Japanese Agricultural Standards and has flameproofing performance specified by the Fire Service Construction Ordinance.

[Conventional technology]

Conventionally, 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 bond urea resin to wood. What is used is one which is adhered by an agent, or one which is obtained by impregnating the obtained 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, a flameproofing agent impregnation process and a drying process are required in addition to the veneer bonding process, which complicates the manufacturing process and increases the equipment cost and 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 a problem, a method of 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. 45-17313). However, the flame-retardant substance shown therein is not suitable for a product such as a flameproof plywood which requires low cost. Therefore, the inventor of the present invention has proposed the low-cost first method used in the conventional dipping method.
A study was conducted to add ammonium phosphate as a flameproofing agent to an adhesive for wood. 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 a urea resin or a urea melamine copolymer resin, and a primary ammonium phosphate of 5 to 15 is added.
An adhesive composition for flameproof plywood, which comprises 5 to 20 parts by weight of a fine alumina particle mixture containing 10 to 60% by weight of melamine and / or melamine isomer.

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 mixture of alumina fine particles 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 primary 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. Further, the fine alumina particle mixture contains 10 to 60% by weight of melamine and / or melamine isomer, but 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 produced as a by-product from the urea-based melamine production plant can also be used preferably. 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%,
To some extent, this component ratio does not require so much rigor.

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

The primary ammonium phosphate and alumina fine particle mixture is sufficiently dispersed and mixed in the urea resin or the urea melamine copolymer resin to form the flame-retardant plywood adhesive composition of the present invention. In the manufacture of plywood, a flameproof adhesive is applied to the plywood veneer and laminated, and then a cold pressure of 5 to 12 kg / cm ² is applied first, and then 80 to 1
A flameproof plywood can be obtained by applying a heat pressure of 6 to 13 Kg / cm ² at 20 ° C. to dip the flameproof adhesive in a veneer moderately and sufficiently bonding it.

〔The invention's effect〕

In the case of producing a flameproof plywood using the flameproof plywood adhesive composition of the present invention, the impregnation and drying steps of the flameproof agent as in the dipping method are not required at all, and a normal plywood production process is performed. The quality can be improved by simply adding the operation of adjusting the flameproof adhesive, which 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〕

 The present invention will be specifically described below 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 components shown in Table 1 below was used as a middle plate. 300 g per 1 square meter of rice 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. The performance test results of the 2.5 mm flameproof plywood thus manufactured are shown in Table 1.

Example 2 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 2 below was used. 300 g per 1 square meter of rice 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 produced are shown in Table 2.

Claims (2)

[Claims] 1. A urea resin or a urea melamine copolymer resin 1
Adhesive for flameproof plywood containing 5 to 15 parts by weight of an alumina fine particle mixture containing 5 to 15 parts by weight of monobasic ammonium phosphate and 10 to 60% by weight of melamine and / or melamine isomers, relative to 00 parts by weight. Composition. 2. The composition according to claim 1, wherein the alumina fine particle mixture is a fine powdery recovery catalyst produced as a by-product in the urea melamine production process.