Process for making soil release polymer granules

Abstract

The subject invention involves processes for making granular compositions comprising soil release polymers, the polymers comprising at least about 10% of substantially linear esters having a backbone; the esters being uncapped or end-capped on one or both ends of the backbone; the esters comprising in their backbones oxyalkyleneoxy units and hydrophobic aryldicarbonyl units; the esters having a molecular weight of from about 500 to about 20,000; the polymers if in solid state having the tendency when exposed to moisture to spontaneously rearrange from an amorphous form which is readily soluble in water to a crystalline form which is relatively insoluble in water; the process comprising the following steps: a) taking the soil release polymers, in which are dispersed from 0% to about 25% alkylaryl or alkyl sulfonate crystallization-reducing stabilizers, in molten state at a temperature of at least about 180.degree. C., and rapidly dissolving the molten polymers in water, forming an aqueous polymer solution having a polymer concentration of up to about 50%, the average temperature of the solution being maintained below about 50.degree. C.; b) dispersing a nonionic surfactant in the molten polymers or in the water prior to step a), the surfactant being an alkylethoxy alcohol nonionic surfactant which is a condensation product of alkylalcohol and ethylene oxide, the alkyl portion being linear or branched, saturated or unsaturated, having from about 8 to about 22 carbon atoms, there being on average of from about 10 to about 100 moles ethoxy per mole surfactant, the nonionic surfactant being from about 2% to about 20% of the aqueous polymer solution, on a dry weight basis; and c) drying the aqueous polymer solution of b), thereby producing a granular composition having a water content of less than about 3%. The subject invention also involves soil release polymer granules comprising such polymers and nonionic surfactant and, optionally, stabilizers.

Dependencies are inferred from the claim text.