| 摘要 |
PURPOSE:To inexpensively form a water-insoluble gel which has excellent mechanical characteristics and is stable over a wide water content range, by blending polyvinyl alcohol with polyvinylpyrrolidone and water in a specified ratio and adjusting the pH of the system to a specified value. CONSTITUTION:This gel compsn. contains three components of polyvinyl alcohol (A) (hereinafter referred to as PVA), polyvinylpyrrolidone (B) (hereinafter referred to as PVP) and water (C). The quantities of the components A, B and C to be blended satisfy all of the following conditions (1) to (3) and the pH of the system is adjusted to 4.5 or below. (1): the quantity of PVA to be blended is 0.5-50wt% based on the entire quantity of the compsn., (2): the quantity of PVP to be blended is 3-90wt% based on the entire quantity of the compsn., and (3): the ratio of PVP to PVA is 0.2 or above in terms of the molar ratio of repeating units.
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