| 摘要 |
In making heat-hardenable and pressable resinous condensates fibrous albuminous materials of animal origin are highly swelled by treatment successively with acids and alkalis, and mixed, where necessary after comminution, with aldehydes and substances condensable with aldehydes, e.g. urea, thiourea, melamine and phenols, and condensed, e.g. at 30 DEG C. to 50 DEG C. preferably under alkaline conditions, e.g. at a pH of 7 to 8, the resulting masses being dehydrated in known manner. The aldehydes may be preliminarily condensed with the substances condensable therewith. Albuminous materials specified are skins, hides, leather scraps, waste, parings and scrapings, sinews, waste meat and fish, fish-skins and whale-meat. Aldehydes specified are formaldehyde, paraldehyde, metaldehyde and hexamethylenetramine. Swellable materials, e.g. cellulose, cellulose derivatives, starch, casein, wheat gluten and horn, may be incorporated in the unswollen condition with the highly swollen materials. In examples (1) highly swelled animal skin is mixed with urea, formalin and hexamethylenetramine and the mixture is condensed at 40 DEG C., dried and ground; (2) highly swelled leather parings are mixed with potato starch, urea, formalin and hexamethylenetetramine, and the mixture condensed; (3) highly swelled lean sinews are reacted with a urea-formaldehyde precondensate. The products may be formed into foils or cords or hot pressed into articles.ALSO:In making a heat-hardenable and pressable condensation product, a fibrous albuminous material of animal origin is highly swelled by treatment successively with acids and alkalis, and mixed, where necessary after comminution, with an aldehyde and casein, and condensed at 30 DEG to 50 DEG C., preferably under alkaline conditions, e.g. at a pH of 7 to 8, with subsequent dehydration of the resulting mass. Albuminous materials specified are skins, hides, leather scraps, waste, parings and scrapings, sinews, waste meat and fish, fish skins and whale meat. Aldehydes specified are formaldehyde, paraldehyde, metaldehyde and hexamethylenetetramine.
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