| 摘要 |
A composition suitable for the core of a games ball such as a golf ball, which is initially solid at ordinary temperatures and is capable of being brought to a normally mobile condition comprises an aqueous proteinaceous colloid gel, a weighting material and a non-labile colloid in a proportion insufficient to form a gel. The proteinaceous colloids may be those such as glue or gelatine which are readily hydrolysed by acids, proteolytic enzymes, saline solutions and organic substances such as resorcinal. They may be preserved by the addition of phenol or chloroisothymol and may be modified by the addition of glycerol. The non-labile colloids are those which are not readily degraded by heat or by acids alone and include the carbohydrate colloids such as cellulose esters and ethers, starches and starch esters, and water dispersible gums such as gum arabic and gum tragacanth. The weighting material may be barytes, lithopone, lead or a lead compound. The composition is preferably put into a rubber sac and the gel converted to a mobile condition either by heating or by bacteria which produce proteolytic enzymes or by the addition to the composition of maleic anhydride, potassium persuphate, resorcinol or sodium bisulphite. Specification 387,084, [Group XV], is referred to.
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