Medical material of polyvinyl alcohol and process of making
AssigneeNippon Oil Co., Ltd.
InventorsTatsuzo Tanabe, Masao Nambu
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Abstract
Provided is a medical material comprising a molded hydrogel obtained by pouring an aqueous solution containing not less than 6 wt. % of a polyvinyl alcohol which has a degree of hydrolysis not less than 97 mole % and average polymerization degree not less than 1,100, into a desired shape of a vessel or mold, freeze-molding the aqueous solution at a temperature lower than -5.degree. C., then partially dehydrating the resulting molded product without thawing it up to a percentage dehydration not less 5 wt. %, and if required, immersing the partially dehydrated, molded product in water to attain a water content thereof in the range of 45 to 95 wt. %.
Claims11
The process of preparing a product suitable for medical use composed of a water-insoluble hydrogel having a high water content which comprises preparing an aqueous solution containing not less than 6 weight percent of a polyvinyl alcohol having a degree of hydrolysis of not less than 97 mole percent and an average polymerization degree of not less than 1100, pouring said aqueous polyvinyl alcohol solution into a desired shape of a vessel or mold, freeze-molding said poured aqueous polyvinyl alcohol solution at a temperature below -5.degree. C., and thereafter partially dehydrating the resultant molded product without appreciable thawing thereof to a dehydration percentage of not less than 5 weight percent.
Dependencies are inferred from the claim text.