Bleach activator compositions, preparation thereof and use in granular detergent compositions

Claim 2

A granular bleach activator composition in the form of an agglomerate comprising by weight thereof: (a) at least 55% of finely-divided organic peroxy acid bleach precursor, (b) from 1% to 25% of water-soluble or water-dispersible organic binding agent for the bleach precursor, the binding agent having a melting point of no more than 40°C, (c) from 1% to 25% of finely-divided water-insoluble natural or synthetic silica or silicate as a surface-coating agent for the agglomerate, the weight ratio of the bleach precursor binding agent to surface-coating agent lying in the range from 10:1 to 1:6.

Claim 3

A composition according to Claim 1 characterized in that the water-insoluble silicate in selected from: (a) aluminosilicates having the general formula I: wherein z and y are integers of at least 6, the molar ratio of z to y is in the range from 1.0 to 0.5 and x is a number such that the moisture content of the aluminosilicate is from 10% to 28% by weight thereof, (b) magnesium silicates of formula II: wherein n is in the range from 0.25 to 4.0, (c) smectite-type clays selected from alkali and alkaline earth metal montmorillonites, saponites and hectorites, (d) kaolinite-type clays selected from kaolin, calcined kaolin, and metakaolin, and (e) mixtures thereof.

Claim 4

A composition according to Claim 1 or 2 characterized in that the binding agent is an alkoxylated nonionic surfactant, preferably an ethoxylated primary or secondary alcohol having an average degree of ethoxylation from 3-12 inclusive and an average HLB in the range from 9.5 to 13.5.

Claim 5

A composition according to any of Claims 1 to 3 characterized in that the agglomerate comprises at least 60% of the bleach precursor, from 5% to 25% of binding agent and from 3% to 25% of surface-coating agent, the weight ratio of binding agent to surface-coating agent lying in the range from 5:1 to 1:2.

Claim 6

A composition according to any of Claims 1 to 3 characterized in that the agglomerate comprises at least 70% of the bleach precursor, from 5% to 20% of binding agent and from 1% to 3% of surface coating agent.

Claim 7

A granular detergent composition characterized in that it comprises from 0.5% to 100% thereof of the granular bleach activator composition of any of Claims 1 to 5.

Claim 8

A composition according to Claim 6 characterized by: (a) from 0.5% to 60% of the granular bleach activator composition, and (b) from 40% to 99.5% of auxiliary detergent components in powder form comprising: (i) from 5% to 35% of inorganic per-compound yielding hydrogen peroxide in water, (ii) from 1% to 30% of anionic surfactant, optionally in combination with nonionic, cationic, zwitterionic or ampholytic surfactant or mixture thereof, and (iii) from 2% to 93.5% of detergency builder.

Claim 9

A composition according to any preceding Claim characterized in that it additionally comprises a polyphosphonic acid or salt thereof having the general formula III: in which n is an integral member from 1 to 14 and each R is individually hydrogen or CH 2 P0 3 H 2 or a water-soluble salt thereof, provided that at least half of the radicals represented by R are CH 2 PO 3 H 2 radicals or water-soluble salts thereof, wherein the weight ratio of water-insoluble silica or silicate to the polyphosphonic acid is the ratio of 100:1 to 1:5.

Claim 10

A process of making a composition according to any of Claims 1 to 8 characterized by forming particles of a mixture of the bleach precursor and binding agent, the particles preferably having an average particle size of less than 3000 microns, and thereafter coating the particles with the finely-divided water-insoluble natural or synthetic silica or silicate, thereby forming the agglomerate.

Claim 11

A process according to Claim 9 characterized by dispersing the binder in liquid form onto a moving bed of the bleach precursor and subsequently dispersing the water-insoluble silica or silicate onto a moving bed of the mixture of bleach precursor and binder.