Preparation method of phenolic resin for fireproof material

Abstract

The invention provides a preparation method of phenolic resin for a fireproof material. The preparation method comprises the following preparation steps: (1) depolymerization and solvation reaction: adding solid paraformaldehyde and phenol into a sealed container; enabling the solid paraformaldehyde to be completely depolymerized and dissolved into a phenol solution to obtain a solvated solution for later use; (2) condensation reaction: slowly injecting the solvated solution in step 1 into a reactor; meanwhile, slowly injecting a catalyst into the reactor, simultaneously adding two types of liquid according to the quantity ratio and stirring at a low speed; after injecting two types of solutions, continually keeping reaction time for 60 to 80 minutes; (3) adjusting the viscosity and canning: cooling the phenolic resin reacted in step 2; adding the diluting agent and adjusting the viscosity and canning. The mol ratio of the phenol to the solid paraformaldehyde is 1 to (0.5 to 0.9). Themethod provided by the invention ensures that the solid paraformaldehyde reacts completely and has no residues; the safety and environment pollution problems of a former technology are solved and thecompressive strength of the fireproof material is improved.

Description

technical field [0001] The invention relates to a preparation method of phenolic resin for refractory materials, belonging to the technical field of refractory materials. Background technique [0002] The applicant ZL 2011100063565.8, in the patent titled a phenolic resin for environmentally friendly thermoplastic refractory materials and its preparation method, provides an environmentally friendly phenolic resin for thermoplastic refractory materials and its preparation method, the material component of which is phenol 100 20-25 parts of solid paraformaldehyde, 0.2-0.4 parts of acid catalyst, 0.2-2.0 parts of alkaline solution, and 20-30 parts of solvent. Add phenol and acidic catalyst to the reactor, raise the temperature to 90°C, then slowly add all the solid paraformaldehyde to the reactor within 2.5 to 3.5 hours, and control the solution temperature between 90 and 108°C; solid paraformaldehyde After adding, control the temperature of the solution between 95-110°C, and ...

AI Technical Summary

Problems solved by technology

[0003] The above-mentioned original process adopts the method of slowly adding solid paraformaldehyde to the solution of phenol and acidic catalyst. Although this method can successfully prepare the phenolic resin for environment-friendly thermoplastic refractory materials, it has the following disadvantages: in the later stage of the reaction, the solid paraformaldehyde will After being added into the container, the solid paraformaldehyde with larger particles will form a layer of film on the surface, resulting in the inability of depolymerization and condensation reaction of the solid paraformaldehyde, which affects the product quality and resin yield

Moreover, when the resin containing unreacted solid paraformaldehyde is used as a refractory material, free formaldehyde is precipitated during the high-temperature drying process, resulting in excessive formaldehyde concentration in the drying tunnel kiln, causing explosion hazards in severe cases, and causing environmental pollution again.