SU622273A1 - Method of producing phenolformaldehide resin - Google Patents

Abstract

A METHOD FOR PREPARING PHENOLFOREDMEDDEHODE RESIN of the resole type, including condensation of phenol and formaldehyde in the presence of ammonia as a catalyst and then adding a modifying agent to the reaction mixture, characterized in that, in order to reduce the heat resistance of the resin and simplify its technology obtaining, as a modifying agent take extraction rosin, modified, 2-; 5 wt.% formaldehyde and 2-5 wt.% \ fumaric acid, in the amount of •• 25-30 wt.h. on 100 ma.ch. phenol. The invention relates to the production of phenolic resins used as a binder in the manufacture of asbestos friction materials. A method for producing modified phenol formaldehyde resin is known. The resin is obtained by condensation of phenol with formaldehyde, followed by modification of gum rosin using ammonia and is used as a binder in the manufacture of friction products and friction press-powder powders. The resin obtained by the known Electro method has the lowest (carbonated residue). the synthesis of gum rosin is very limited for its synthesis.; In addition, during the boiling of the reaction mixture, which lasts 80-90 minutes, the rosin is sublimated and condenses on the walls of the refrigerator, clog the pipe This fact significantly degrades the resin production technology. The purpose of the present invention is to increase the heat-resistance of the modified phenol formaldehyde resin and to simplify its production., • The goal is achieved by the fact that for the condensation of phenol with formaldehyde ^ in the presence of ammonia, modifying agent take extraction rosin, modified with formaldehyde from 2 to 5 wt.% and fumaric acid from 2 to 5. wt.%, in the amount of 25-30 wt.h., per 100 wt.h. phenol. The composition of gum and extraction rosin is given in Table I. Example 1. 100 mach. phenol; 53 ma.ch. formaldehyde (in the form of 37% -: 6 formalin nog) and 1.5 wt.h. ammonia (in the form of 25% ammonia water) is loaded into the reactor equipped with a stirrer, a thermometer and a refrigerator. The reaction mixture is heated to 80 ± 2 ** C and held until the refractive index is reached 1,442-1,456. The reaction mixture is then cooled to; 65-70 ** C and 25 wt.h. ektratsionnoy rosin modified with formaldehyde and fumaric cellulose are introduced (L ^: toIsd I > & Dm00

Description

in the amount of 2-5 mas% of each. The mixture is heated to boiling and held at a boiling point of 55 mission. Drying of the resin is carried out under vacuum 400600 mm Hg. until gelation time is reached at 5tf С 60-150 s. The resin is obtained in the form of a solid product of a dark brown color that is soluble in alcohol and acetone. PRI mme R 2. 100 ma.ch. phenol, 55 May, h formaldehyde (in the form of 37% formalin) and 20 wt.h. ammonia (in the form of ammonia water) is loaded into the reactor, equipped with a stirrer, a thermometer and a refrigerator. The reaction mixture is heated to and held until the refractive index is reached 1,442-1,456. Next, the reaction mixture is cooled to 65-70 and 30 parts by weight are introduced. extraction rosin modified with formaldehyde and fumaric acid. Further condensation and drying of the resin is carried out according to example 1. The properties of the resins obtained by the proposed and known methods are given in table 2. The heat resistance of the resins obtained by npejEViaraeMbiM and by known methods was determined by thermogravimetric analysis. The results are presented in Table 3. The data table, 2 and 3 show that the heat resistance of the resins obtained by the proposed method, higher than the same characteristics of the resin obtained in a known manner. Resins obtained by the proposed and known methods were tested as Table 2 as a binder in asbestos technical products. The test results are given in table.4. The test results show that the samples based on resins manufactured by the proposed method comply with the standards of GOST 10851-73 for FK-24 material and are more wear-resistant than the resin-based material manufactured by a known method. The introduction of the proposed method makes it possible to carry out the quality of asbestos friction materials, eliminate the shortage of gum rosin, and the economic effect will be more than 70 thousand rubles per 1000 tons of resin. Table 1

Content of free phenol,% Content of free formaldehyde,% Content of meth-field groups,%

The rate of gelation at 150 ° C, s

10.2 Footprints 16.2 140

Drop point, s

Carbonation

Continuation of table 2

80

81

Claims (1)

METHOD FOR PRODUCING Phenolformaldehyde Resin of the resole type, including condensation of phenol and formaldehyde in the presence of ammonia · as a catalyst, followed by the addition of a modifying agent to the reaction mixture, characterized in that, in order to increase the heat resistance of the resin, as well as simplify the technology for its preparation , as a modifying agent take extraction rosin, modified, 2.5 wt.% formaldehyde and 2-5 wt.% fumaric acid, in an amount> 25-30 May. hours per 100 ma.ch. phenol.