RU2034001C1 - Method of foam plastic preparing - Google Patents

Abstract

FIELD: plastic materials. SUBSTANCE: method is realized by mixing of resol phenolformaldehyde resin ФРВ-IА, carbamidoformaldehyde resin, foaming-hardening agent DFU-3, chrome oxide, aluminium oxide, surface-active substance, aluminium powder and epoxy resin taken at the following mass ratio 41.1-48.8:4.8-6.7:28.5-29.6:1.1-2.0:7.3-8.5:2.1-3.5:3.2-4.0:4- .2-4.6, respectively, following by mixture shaping at direct current voltage 24-160 V, at current density 170-180 mcA for 10-15 min. EFFECT: improved method of foam plastic preparing. 1 tbl

Description

 The invention relates to the production of foams based on phenol-formaldehyde resin, intended for use as heat-insulating materials in construction.

A known method of producing foam by obtaining a mixture of rezol phenol-formaldehyde resin, urea-formaldehyde resin, surfactant, aluminum powder, acid catalyst and volcanic ash filler, followed by molding the resulting mixture and introducing through bayonet molding with a mixture of volcanic ash [1]
The known method of producing foam does not allow to increase the strength characteristics of the foam due to the introduction of volcanic ash into the mixture by baying, which leads to a deterioration in the structure formation, i.e., an uneven distribution of ash in the spatial structure of the mixture. In addition, the use of an acid catalyst for phosphoric acid by a known method does not sufficiently effectively affect the binding reaction of low molecular weight products of phenol-formaldehyde resin, which also significantly degrade the strength characteristics of the foam.

The closest in technical essence and the achieved result to the present invention is a method for producing foam, comprising obtaining a mixture of phenol-formaldehyde resole resin FRV-1A, consisting of phenol-formaldehyde resin resole type, aluminum powder and surfactant OP-7, foaming-curing agent VAG -3 and filler, which is taken as waste processing apatite ores, followed by molding the resulting mixture [2]
However, the known method for producing foam does not allow increasing the strength characteristics of the finished material due to the introduction of apatite ores into the mixture, which contain a large amount of metal oxides and salts, causing the destruction of phenol-formaldehyde resin, the formation of low-viscosity compounds and fluid, which leads to a decrease in the multiplicity foaming and subsidence of the foam, as well as to increase the weight of the foam.

 The aim of the invention is to increase the strength of the foam.

 The goal is achieved in that the proposed method for producing foam, including obtaining a mixture of rezol phenol-formaldehyde resin with urea-formaldehyde resin, a foaming-curing agent VAG-3 and a filler, followed by molding the resulting mixture, according to the invention, a surfactant, aluminum powder is additionally introduced into the mixture and epoxy resin, and chromium oxide and aluminum oxide are used as filler, while the components are taken in the following ratio, wt. Resol phenol-formaldehyde resin FRV-1A 41.1-48.8 Urea-formaldehyde resin 4.8-6.7 Surface-active substance OP-7 2.1-3.5 Aluminum powder 3.2-4, 0 Epoxy resin 4.2-4.6 Chromium oxide 1.1-2.0 Alumina 7.3-8.5 Foaming-curing agent VAG-3 28.5-29.6 wherein the mixture is formed under tension DC 24-160 V, at a current density of 170-180 μA, for 10-15 minutes

 The introduction of a surfactant, aluminum powder and epoxy into the mixture leads to the formation of a reactive compound and to the binding of low-binding compounds of phenol-formaldehyde resin. The use of chromium oxide and alumina as catalysts, which are catalysts for the interaction of epoxy resin with phenol formaldehyde, which, when restored to pure metals, preserve the vital activity and foaming ability of resins, increases the strength of the resulting foam.

 In addition, molding the resin under a DC voltage of 24-160 V at a current density of 170-180 μA for 10-15 minutes allows the electrophoretic process to proceed in the mixture, i.e. accelerates the foaming and curing of the mixture, the separation of moisture from the foam composition, improves structure formation.

 The proposed method for producing foam is not known from the prior art, which allows us to conclude that it meets the criterion of "novelty." A method of obtaining a foam is not obvious to a person skilled in the art, which allows us to conclude that this technical solution meets the criterion of "inventive step".

 The present invention can be carried out using available materials and techniques in the national economy, which allows us to conclude that it meets the criterion of "industrial applicability".

To implement the method of producing foam, the following materials manufactured by the domestic industry were used:
phenol-formaldehyde resin of a resol type FRV-1A, which is a mixture of a surfactant, aluminum powder, phenol-formaldehyde resin of a resol type. TU 6-05-1104-78;
urea-formaldehyde resin KF-MT-15, GOST 14231-78;
VAG-3 blowing-curing agent (a condensation product of sulfophenylurea, formaldehyde, orthophosphonic acid and morpholine resin) TU-6-06-1116-74;
surfactant OP-7 is a mixture of polyethylene glycol ethers of mono- and dialkylphenols. GOST 8433-81;
chromium oxide TU 18307-78;
aluminum oxide GOST 8136-85;
epoxy resin ED-20 GOST 10587-84;
aluminum powder GOST 5494-71.

 To obtain comparative data and substantiate the essence of the invention, 3 foam formulations were prepared by the proposed method and the well-known technical solution taken as a prototype (see ed. St. USSR N 1407938, class C 08 L 61/10, publ. 1988).

 PRI me R 1. To 48.8 g (48.8 wt.) Phenol-formaldehyde resole type resin was added with constant stirring 4.8 g (4.8 wt.) Urea-formaldehyde resin, 2.1 g (2.1 wt.) surfactant, 3.2 g (3.2 wt.) aluminum powder, 4.2 g (4.2 wt.) epoxy resin, 1.1 g (1.1 wt.) chromium oxide, 7.3 g (7.3 wt.) Alumina. The mixture was thoroughly mixed for 1-3 minutes to obtain a homogeneous mass and stood for 2 hours. 28.5 g (28.5 wt.) Of a foaming-curing agent were added to the resulting mass with constant stirring. The resulting mixture was poured into a greased form with the connected electrodes of a constant current source installed at a voltage of 24 V at a current density of 170 μA. Current was passed for 10 minutes. Then the tension was removed from the mold, the mold was disassembled, and the foam samples made were removed.

 The prepared foam samples were tested in a known manner according to GOST 17177-87 for density, compressive strength, heat resistance, and moisture absorption.

 Under conditions similar to example 1, foams were obtained in examples 2-3 with varying proportions of the components within the protected limits.

 Experimental studies of foam samples made by the proposed and known methods in comparison are shown in the table.

 As can be seen from the above examples and table data, the foam made by the proposed method has high quality indicators compared with the performance of the foam made by the known method.

Claims (1)

 METHOD FOR PRODUCING FOAM PLASTIC by mixing resol phenol-formaldehyde resin FRV-1A with urea-formaldehyde resin, VAG-3 foaming-curing agent and filler with subsequent formation of the mixture, characterized in that chromium and aluminum oxides and an additional surfactant, aluminum and epoxy resin in a weight ratio of rezol phenol-formaldehyde resin, urea-formaldehyde resin, foaming-curing agent VAG-3, chromium oxide, oxide aluminum, surfactant, aluminum powder and epoxy, respectively 41.1 48.8 4.8 6.7 28.5 29.6 1.1 2.0 7.5 8.5 2.1 3.5 3 , 2 4.0 4.2 4.6, the formation is carried out at a DC voltage of 24 160 V at a current density of 170 180 MkA for 10 15 minutes

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