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为了改善锆砂和铝矾土这两种水溶性涂料的悬浮性,覆盖性,并能在高温下也能与铸型和芯子表面粘牢,以及其它一些性质,可以试用最有效果的悬浮剂——聚乙烯醇〔CH_2CHOH〕_n,羧甲基纤维素〔C_6H_7O_2(OH)_(3-x)(CH_2COOH_x〕_n,藻脘酸钠〔C_6H_5O_2(OH_2O)ON_a〕_n以及聚合物K-4。在制备涂料的时候,首先把它们加到水中以得到均匀的溶液,而后再加入粘结剂和填充料。由于降低高分子化合物溶液的PH值,涂
In order to improve the suspensibility and coverage of the two water-soluble coatings of zircon sand and bauxite and to adhere to the surface of the mold and the core at high temperatures, as well as other properties, one can try the most effective suspension Agents - polyvinyl alcohol [CH_2CHOH] _n, carboxymethylcellulose [C_6H_7O_2 (OH) _ (3-x) (CH_2COOH_x) _n, sodium alginate [C_6H_5O_2 (OH_2O) ON_a] _n and polymer K-4 In the preparation of coatings, they are first added to water to obtain a uniform solution, and then added to the binder and filler due to lower the pH of the polymer compound solution, the coating