| 摘要 |
PURPOSE:To obtain an open-cellular foam with high moisture-permeability and without coloring, by adding azodicarbonamide and 4,4'-oxybis(bernzenesulfonyl hydrazide) to a PVC paste and heating to gelation in the presence of an alkali. CONSTITUTION:An aq. alkaline soln. such as aq. sodium hydroxide soln. is added to a PVC paste to which a stabilizer, a plasticizer, a small amt. of surfactant, azodicarbonamide (AC), and 4,4'-oxybis(benzenesulfonyl hydrazide) (OBSH) are added to form a homogeneous mixed paste. Then the paste is applied onto a backing material such as paper or woven textile or onto releasing paper, or filled into a mold, and then heated to gelation. Although the amt. of both AC and OBSH, and the ratio of AC to OBSH are also important factors, the dominant material for open-cell formation is AC. 2-6pts.wt. AC based on 100pts.wt. PVC resin is necessary for assurance of moisture, gas, and water permeabilities. The addn. ratio of AC to OBSH in the range of 1 to 0.5-20 is desirable.
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