How to test the acid and alkaline resistance of the paint film?

For coating products used to prevent acid and alkali corrosion, or used in environments where acid and alkali corrosion often occur, acid and alkali corrosion resistance tests must be carried out. The method is to make a paint film model first, after edge sealing and drying, immerse in the acid or alkali solution of the specified variety and concentration according to the regulations, at the specified temperature, after a certain period of time, take it out of the solution, rinse with water, and then Check the integrity and damage of the paint film. For example, architectural coating products are required to have a certain degree of alkali resistance. The test method is to immerse the sample in a saturated lime solution for a period of 48 hours. The coating film is qualified if it does not bubble, change color, or fall off.