CS274336B1 - Plates from hardened paper with decorative surface with reduced inflammability - Google Patents

Abstract

The solution concerns a board composed by a surface treatment component, impregnated with melaminoformaldehyde resin, and an inner layer component, impregnated by modified phenol formaldehyde resin. Both layers are pressed together. The phenol formaldehyde resin is modified by a mixture of N-hydroxymethyl-3-dimethoxyphosphorylpropionamide and hexamethylenetetramine in the ratio of 1:0.2 to 0.4:0.02 to 0.04, while the applied amount of modified resin ranges from 35 to 70 percent by weight, related to the paper weight.<IMAGE>

Description

The invention relates to hardened paper sheets having a decorative surface with reduced flammability by means of a modified phenol-formaldehyde resin.

Toughened paper sheets with a decorative surface are produced by joining special papers impregnated with thermosetting resins by pressing at higher temperatures and pressures, the inner layer of the boards being made of phenolic resin impregnated paper and the surface layer is then treated with impregnated paper impregnated with melamine-formaldehyde resins. Decorative surfaces are hard, resistant to abrasion, scratches, heat, chemicals and mechanical stress. Their disadvantage, however, is the partial flammability. When a flame retardant or flame retardant composition is used in the manufacture thereof, the laminates exhibit increased flame resistance with flame retardant properties. Boards are used wherever the emphasis is placed on the functional and aesthetic value of the whole, which are parts of eg furniture in the treatment of interiors of residential, public and industrial buildings, vehicles, etc. There is a growing tendency in the world. At present, the non-flammability of laminates is achieved by adding a flame retardant to the impregnating resins by combining halogenated organic compounds, inorganic phosphorus or nitrogen compounds, as well as metal oxides. However, it has been found that the addition of these non-combustible additives will increase the fire resistance, while at the same time reducing the mechanical and electrical properties. For these reasons, there is a need for laminates with reduced flammability, but with all functional properties retained, or with reduced deterioration to a minimum.

This disadvantage is overcome by the cured paper with a decorative surface with a reduced flammability consisting of a surface layer impregnated with a melamine-formaldehyde resin and an inner layer which is saturated with the modified phenolformadehyd resin according to the invention. The principle is that the inner layer is impregnated with a phenol-formaldehyde resin, modified by the addition of a mixture of N-hydroxymethyl-3-dimethoxyphosphorylpropionamide and hexamethylenetetramine in a ratio of 1: 0.2 to 0.4: 0.02 to 0.05, with the amount of modified resin applied. It is 35 to 70% by weight based on the weight of the paper.

The advantage of the boards according to the invention is a significant increase in fire resistance. The addition of an organic phosphorus and nitrogen compound does not have a negative effect on the electrical and mechanical properties of conventional laminates.

In order to further elucidate the invention, an example of embodiment 1 is given below

Example

A. Preparation of phenol-formaldehyde resin modified with N-hydroxymethyl-3-dimethoxyphosphoryl propionamide and hexamethylenetetramine. 30 parts of N-hydroxymethyl-3-dimethoxyphosphorylpropionamide and 4 parts of hexamethylenetetramine are added to 100 parts by weight of the phenoformal CS 274 336 B1 of the dehyd resin having a molar ratio of 1: 1.1. After the addition of the modifying agents, vacuum distillation is carried out at a pressure of 0.03 to 0.005 MPa and a temperature of 50 to 60 ° C. After distillation, the modified resin dissolved. in an amount of methanol such that the dry matter content is 60 to 67% with a maximum free phenol content of up to 10%. (solution A)

B. Opaque, pattern, barrier, white, and leveling surface impregnation papers are prepared by saturating the paper with an aqueous solution of melamine-formaldehyde resin and then drying at 150-180 ° C. The resin deposit is in the range of 35 to 245% by weight, based on the weight of the paper. Internal impregnated papers - barrier, internal and leveling - are prepared by saturating the paper with a methanol solution of the modified resin (solution A) and drying. The resin deposit is in the range of 35 to 70% by weight, based on the weight of the paper. The prepared components of the surface and interior impregnating papers are pressed at a specific pressure of 10 MPa and a temperature of 136-160 ° C for 50-80 min.

Claims (1)

Toughened paper with a flame retardant decorative surface consisting of a melamine-formaldehyde resin impregnated surface layer component and a modified phenol-formaldehyde resin impregnated inner layer component, the two layers being pressed together, characterized in that the inner layer is impregnated with a N-modified phenolformaldehyde resin-modified N 3 _T dimetoxyfosforylpropionamidu and hexamethylenetetramine in a ratio of 1: 0.2 to 0.4: 0.02 to 0.04, wherein the applied amount of the modified resin is 35 to 70% by weight based on the weight of the paper.