Preparation method of ultra-low-viscosity hydroxypropyl methyl cellulose
A technology of hydroxypropyl methylcellulose and viscosity, which is applied in the field of preparation of ultra-low viscosity hydroxypropyl methylcellulose, can solve the problems of no ultra-low viscosity hydroxypropyl methylcellulose preparation method, etc., and achieve reduction The effect of production cost, expansion of production volume, and expansion of application range
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Examples
Embodiment Construction
[0019] The ratio of raw materials by weight for preparing ultra-low viscosity HPMC is: 70 parts of toluene isopropanol, 1 part of water, 8 parts of refined cotton, 7 parts of sodium hydroxide, 9 parts of methyl chloride, 3 parts of propylene oxide, and 1.5 parts of glacial acetic acid ;
[0020] Concrete preparation steps are:
[0021] The first step is to mix the raw materials: in the reaction kettle, after adding solvent, water and sodium hydroxide, the temperature of the alkali is raised to 70°C, and the temperature is kept for 30 minutes;
[0022] The second step, alkalization: lower the temperature of the above alkali to 30°C, add refined cotton, stir for 1 hour, and control the temperature at 25-40°C; carry out alkalization reaction; after the alkalization is completed, the reactor is evacuated to 0.05-0.07mpa , add propylene oxide, methyl chloride, keep for 30 minutes;
[0023] The third step, etherification: the temperature is raised to 55±3°C and kept for 1.5 hours;...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More