GB453438A - Preservation of oils, fats and waxes and substances containing them - Google Patents

Abstract

To prevent rancidity in light-unstable oils, fats and waxes and substances containing them, the substances are protected from light having a wave-length of 2900--4700A DEG by excluding such light from the substances by means of a pellicle formed of a material normally transparent to visible light and combined with an organic dyestuff which renders it substantially opaque to light of 2900--4700A DEG and substantially non-absorbent of light of wave lengths other than 2900--4700A DEG . The material is regarded as substantially opaque when it transmits not more than 25 per cent of any one wave length in the stated range and not more than 10 per cent in total transmission within that range; and there should be not less than 50 per cent total transmission in the visible region 4900--6900A DEG . The Specification mentions a number of dyestuffs and the concentrations suitable for treating sheets of regenerated cellulose ,001 inch thick in a 90--100 DEG C. bath. The base sheet material may be glass, synthetic plastics, gelatine, casein, cellulose derivatives, composite materials &c., and the protective element may take the form of tubing or of a plate, cap (for a carton, bottle &c.), wrapping blank, band, bag, bottle, carton, box or lining; or a glass jar &c. or a sheet of regenerated cellulose &c. may be coated with a lacquer, e.g. of nitrocellulose, a plasticizer, a gum or resin and a dyestuff, with or without a further protective coating. Specification 383,661, [Group VI], is referred to.ALSO:To prevent rancidity in light-unstable oils, fats and waxes and substances containing them, the substances are protected from light having a wave-length of 2900-4700A DEG by excluding such light from the substances by means of a pellicle formed of a material normally transparent to visible light and combined with an organic dyestuff which renders it substantially opaque to light of 2900-4700A DEG and substantially non-absorbent of light of wave lengths other than 2900-4700A DEG . The material is regarded as substantially opaque when it transmits not more than 25 per cent of any one wave length in the stated range and not more than 10 per cent in total transmission within that range; and there should be not less than 50 per cent total transmission in the visible region 4900-6900A DEG . The Specification mentions a number of dyestuffs and the concentrations suitable for treating sheets of regenerated cellulose 0,001 inch thick in a 90-100 DEG C. bath. The base sheet material may be glass, synthetic plastics, gelatine, casein, cellulose derivatives, composite materials &c., and the protective element may take the form of tubing or of a plate, cap (for a carton, bottle, &c.), wrapping blank, band, bag, bottle, carton, box or lining; or a glass jar &c. or a sheet of regenerated cellulose &c. may be coated with a lacquer, e.g. of nitrocellulose, a plasticizer, a gum or resin and a dyestuff, with or without a further protective coating. Specification 383,661 is referred to.