| 摘要 |
PURPOSE:To improve the quality of a welding rod and to reduce the cost thereof by incorporating a polysaccharide which is constituted of a specific molar ratio of glucose, mannose and mannuronic acid, is acetylated and has a prescribed mol.wt. into a coating material. CONSTITUTION:The polysaccharide is constituted of the glucose, mannnose and mannuronic acid at the respective molar ratios of 1:0.4-0.7:4-17 and is acetylated at about 0-1.0 deg. of acetylation. The mol.wt. with a 3,5-dinitrosalicylic acid method is made 10<3>-10<5>mol.wt. Such polysaccaride is incorporated into the coating material at 0.05-5% by the total amt. thereof in place of the conven tional sodium alginate. The dislodging amt. of the coating is decreased by using the welding rod coated with such material. The quality of the welding rod is improved and the cost thereof is reduced by using the inexpensive polysac charide.
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