Preparation method of phenol-formaldehyde resin for magnesia carbon bricks

Abstract

The invention discloses a preparation method of phenolic resin for magnesia-carbon bricks. The specific implementation steps are as follows: first, phenol and formaldehyde are put into a reaction vessel according to a certain feeding ratio, and a certain amount of TEOS is added under stirring conditions, and a certain amount of NaOH is added. The solution is heated and reacted, and the reaction temperature is controlled below 95°C. Then add a certain amount of acetic acid to the reaction solution to adjust the pH value of the reaction solution between 6 and 7, and finally adopt vacuum dehydration to obtain the phenolic resin. The raw materials used in the present invention are phenol and formaldehyde, wherein the molar ratio of phenol, formaldehyde and NaOH is 1:1.2~1.4:0.05~0.1, the added TEOS modifier accounts for 1.5%~2.5% of the raw material mass, and the reaction temperature is 85 ℃~95℃, the reaction time is between 2h~3h, the temperature is controlled at 60~75℃ during the vacuum dehydration process, and the pressure is 0.08~0.09Mpa. The phenolic resin binder obtained by the invention has a low residual carbon rate and a greatly increased viscosity, can effectively suppress cracking and bubbling of the carbonized layer, and is greatly beneficial to the improvement of the performance of refractory products.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a preparation method of phenolic resin for magnesia-carbon bricks. Background technique [0002] Magnesia carbon brick is a refractory product made of magnesia and graphite as the main raw materials, plus an appropriate amount of binder, which is formed by high pressure and heat treated at low temperature. Magnesia-carbon bricks originated in Japan and are a new type of refractory product developed in the early 1970s. It is mainly used for working linings of converters for steelmaking, electric furnaces, and refining ladles outside furnaces. [0003] Phenolic resin is a synthetic resin that was first discovered and widely used, and has been widely used in many fields due to its many properties, and was used as a binder for refractory unfired products in 1975. At present, carbon-containing refractory products still widely use phenolic resin as a binder. Compared with t...

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Problems solved by technology

[0004] In order to solve the problems of low thermal decomposition temperature and poor oxidation resistance of phenolic resin as a binder, so that carbon-containing refractory magnesium products still have greater high-temperature strength and good safety performance when used at high temperatures, a simple method is obtained. , A method for preparing a phenolic resin binder with excellent performance, the present invention provides a method for preparing a phenolic resin for magnesia carbon bricks