RU1790585C - Pressed composition for plates of wood and shavings - Google Patents

Abstract

SUMMARY OF THE INVENTION: the press composition comprises a urea-formaldehyde resin of 5.8-10.5%; urea metallophosphate is the product of the interaction of aluminochromophosphate 50% binder (AHFS) or aluminoborophosphate 50% concentrate (ABFC) and urea in a weight ratio of 1: 5-7 1.0-1.5; fatty acid selected from the group comprising tricosanic, lignoceric, pentacosanoic, cerotinic, 0.8-1.0; chopped wood - the rest. Characterization of the resulting chipboards; density 815-820 kg / m3; ultimate bending strength 26.1-28.2 MPa; thickness swelling 6.1-6.2%; formaldehyde emissions from slabs: freshly prepared 0.010-0.012 mg / m, six months after production of 0.01 mg / m3. 2 tab. ate with

Description

The invention relates to building materials, and can be used for the production of chipboards used as structural and decorative-facing materials.

A known press material for the manufacture of chipboards, including, wt.%: Chopped wood 75-80; urea resin of 59% concentration 15.0-20.0; a zinc aluminophosphate binder of 10% concentration of 0.1-10.0; hydrophobic additive of 0.5 to 1.0.

The closest to the invention in technical essence and the achieved result is a press composition for

particle boards, including, wt.%: urea-formaldehyde resin 8.5-14.0; metallophosphate binder 11-20; hydrophobic additive 0.5 to 1.0; chopped wood 65 - 80.

The disadvantages of particle boards made from this press pulp are their low strength characteristics and high formaldehyde content.

The purpose of the invention is to increase the strength characteristics and reduce the emission of formaldehyde from the plates,

For this, a chipboard press composition comprising

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wt.%: urea-formaldehyde resin (dry solids) 5.8 - 10.5; metallophosphate binder 1.0-1.5; a hydrophobic additive of 0.8 - 1.0 and chopped wood - the rest, contains urea metallophosphate as a metal phosphate binder - the product of the interaction of aluminochromophosphate 50% binder or aluminoborophosphate 50% concentrate and urea in a weight ratio of 1 : 5–7, respectively, as a hydrophobic additive, a fatty acid selected from the group consisting of tricosan, lignoceric, pentacosan and cerotinic.

As components of the press composition use: urea-formaldehyde resin brand KF-MT-15 66% concentration; a metallophosphate binder which is the product of the interaction of an aluminochromophosphate binder of a 50% concentration or an aluminoborophosphate binder of a 50% concentration and urea in a weight ratio of 1: 5-7, respectively; wood shavings (hardwood and coniferous species) from the DS-8 machine are conditioned, dried to a moisture content of 3-4%; a fatty acid selected from the group comprising tricosanic, lignoceric, pentacosanic and cerotinic.

The introduction of urea into an aluminochromophosphate or aluminoborophosphate binder increases the complexing ability of urea due to the occurrence of urea metallophosphate, which

determines the improvement of the properties of the finished material.

Urea metallophosphate, which has acidic properties, reduces urea resin consumption without compromising

physical and mechanical characteristics of the plates, contributes to a deeper polymerisation of the resin. Urea metallophosphate, an carbamide, is an acceptor and forms stable bonds with formaldehyde. All this leads to a decrease in the emission of free formaldehyde from the plates, reduces their toxicity;

The manufacture of chipboards is carried out on standard equipment using traditional technology.

The composition of the press composition is given in table. 1, properties are in table. 2

Claims (1)

The claims A press composition for chipboards, including a urea-formaldehyde resin, a metal phosphate binder, a hydrophobic additive and chopped wood, characterized in that, in order to increase the strength characteristics and reduce the emission of formaldehyde from the boards, it contains as a metal phosphate binder urea metallophosphate is the product of the interaction of aluminochromophosphate 50% binder or aluminoborophosphate 50% concentrate and urea in mass a ratio of 1: 5-7, respectively, and as a hydrophobic additive, a fatty acid selected from the group comprising tricosanic, lignoceric, pentacosanic and cerotinic, in the following ratio of components, wt.%: Urea-formaldehyde resin (on a dry residue) 5, 8-10.5 Urea metallophosphate 1.0-1.5 Specified hydrophobic additive 0.8-1.0 Chopped wood Else Table 1 Continuation of the table. 1 Table 2