US Patent 7871974 Process for making bleach particles

A process for making bleach granules comprising a bleach selected from the group of diacyl, tetraacyl peroxide and mixtures thereof, selected from diacyl peroxides of the general formula:R1—C(O)—OO—(O)C—R2 in which R1 represents a C6-C18 alkyl group and R2 represents an aliphatic group compatible with a peroxide moiety, such that R1 and R2 together contain a total of 8 to 30 carbon atoms; the tetraacyl peroxide is selected from tetraacyl peroxides of the general formula:R3—C(O)—OO—C(O)—(CH2)n-C(O)—OO—C(O)—R3 in which R3 represents a C1-C9 alkyl group and n represents an integer from 2 to 12, wherein the process comprises the step of dry granulating the diacyl and/or tetraacyl peroxide.