| 摘要 |
A glue base comprises an unconverted starch in substantially dry powdered form containing a substantially stable solid peroxide and urea or a derivative thereof adapted to render the glue prepared from the base more fluid and more stable and retard evaporation of water from the glue after application, the ingredients being in proportion so that upon bursting of the starch of the base by aqueous caustic alkali solution or in the case of cassava starch by either caustic alkali solution or water at the bursting temperature of the starch, there can be formed a liquid glue containing as low as about 1,3-2,5 parts of water to one part of glue base and suitable for gluing plywood, bentwood and similar objects. The invention also comprises a glue containing the products of reaction of a starch, a peroxide and urea or a derivative thereof, dissolved in water. In examples: (1) and (2) cassava starch is mixed with barium peroxide, soda ash, whiting and urea; the resulting glue base may be converted by heating to 160 DEG F. with sodium hydroxide solution; (3) and (4) sago starch is similarly employed; (5) potato starch is similarly employed; (6) corn starch is similarly employed. Part of the caustic alkali employed in converting the glue base may be replaced by carbon disulphide. The barium peroxide may be replaced by other peroxides which are fairly stable crystalline substances, whilst an equivalent amount of hydrogen peroxide or sodium peroxide may be added to the kettle during conversion. The Specification as open to inspection under Sect. 91 comprises the use of any oxidizing agent capable of converting the starch, and is not restricted in respect of the proportions of the ingredients. This subject-matter does not appear in the Specification as accepted. |
