GB1398785A - Bleaching assistants and the preparation thereof - Google Patents

Abstract

1398785 Detergents containing bleach HENKEL & CIE GmbH 1 Aug 1972 [2 Aug 1971 21 Feb 1972] 35808/72 Heading C5D [Also in Divisions B1 and D1] A bleaching assistant suitable for use in pulverulent washing and bleaching compositions, comprises pear-shaped to globular particles having a diameter of 0À01 to 2À5 mm., at least 70% of which have a diameter of 0À1 to 1 mm. and the particles being composed of: (a) 10-70% by weight of at least one activator for per-compounds which is selected from N-acyl and O-acyl compounds and carbonic acid esters of EW not more than 170, the activation value of which for the percompounds amounts to more than 3, and (b) 30-90% by weight of a mixture of saturated fatty acids (12-24 C) and a polyethylene glycol with an average molecular weight of 1000-20,000, in the proportion by weight of from 5 : 1 to 1 : 4, preferably 3 : 1 to 1 : 2À5, the melting point of the activator/acid/polyethylene glycol mixture being above 35‹ C. Preferably at least 90% by weight of the particles have a diameter of from 0À1-1À6 m. The bleaching assistant A may be present in admixture with further pulverulent bleaching components B, such as a per-compound in the weight ratio A : B of from 1 : 5 to 5 : 1 and such that 0À05-2 mol of activator is present per gram atom of active oxygen, and pulverulent washing composition components C, many of which are specified. The proportion by weight of component C to the sum of components A and B may be from 1 : 2 to 10 : 1, preferably from 1 : 1 to 5 : 1. In the examples, bleaching assistants comprise, by weight, (i) 37% tetraacetyl glycoluril, 46% fatty acid mixture (94% stearic acid and 6% palmitic acid) and 17% polyethylene glycol of molecular weight 10,000; (ii) 38À5% tetraacetyl glycoluril, 23% stearic acid and 38À5% polyethylene glycol (MW 10,000); (iii) 40% tetraacetyl glycoluril, 30% polyethylene glycol (MW 4000) and 30% fatty acid mixture (8% palmitic acid, 72% stearic acid, 8% arachidic acid and 12% behenic acid), and (iv) 40% tetraacetyl glycoluril, 30% stearic acid and 30% polyethylene glycol (MW 10,000). In further examples, (v) 27 PBW of the bleaching assistant (i) is mixed with 10 PBW sodium perborate tetrahydrate and 63 PBW of a pulverulent washing composition having the following constituents based on the weight of the total composition: 7% ndodecyl benzene sulphonate (Na salt), 2% oleyl alcohol with 10 ethylene glycol ether groups, 33% pentasodium triphosphate, 6% soda, 3À5% sodium silicate (Na 2 O: SiO 2 = 1: 2), 2À5% magnesium silicate, 0À2% sodium ethylene diaminotetraacetate, 0À3% optical brightener, 1% sodium carboxymethyl cellulose, and 7À5% water; (vi) 30À3 PBW of the bleaching assistant (ii) are mixed with 10 PBW sodium perborate tetrahydrate and 57À7 PBW of the abovementioned pulverulent washing composition; (vii) 28 PBW of the bleaching assistant (iii) are mixed with 10 PBW of sodium perborate tetrahydrate and 62 PBW of the washing composition. The bleaching assistants may be prepared by a spray-drying process.