Sodium tripolyphosphate composition and method of producing it

In the process of preparing detergent formulations containing:

• a) sodium tripolyphosphate in amounts of about 10% to about 50% by weight,
• b) alkalinity-imparting ingredients in amounts of about 10% to about 60% by weight,
• c) surface-active ingredients in amounts of about 0% to about 20% by weight,
• d) oxidizing, soil and stain removing ingredients in amounts of about 0% to about 12% by weight,
• the improvement that consists essentially of employing as the ingredient in a) above, a sodium tripolyphosphate (STPP) comprising moisturized granules of essentially phase II STPP containing no more than about 5% by weight of phase I sodium tripolyphosphate which yields a non-caking, free flowing detergent formulation when added to water in the absence of agitation, said STPP produced by:
• e) forming granules of anhydrous, essentially phase II STPP by heating of sodium orthophosphate salts,
• f) contacting the STPP granules with a quantity of water, the upper limit being below the point at which the wetted granules commence to coalesce and are no longer free flowing, the lower limit of water being that quantity which is sufficient to maintain the free flowing granular character of the STPP granules in aqueous media,
• g) drying the wetted STPP granules from f) at a sufficient temperature to expel unbound water but not the bound water, so that no more than 0.5% of unbound water is present, and
• h) recovering the moisturized and dried, essentially phase II granules from g) containing no more than about 5% by weight of phase I sodium tripolyphosphate.

In the process of preparing detergent formulations containing:

• a) sodium tripolyphosphate in amounts of about 10% to about 50% by weight,
• b) alkalinity-imparting ingredients in amounts of about 10% to about 60% by weight,
• c) surface-active ingredients in amounts of about 0% to about 20% by weight,
• d) oxidizing, soil and stain removing ingredients in amounts of about 0% to about 12% by weight,
• the improvement that consists essentially of employing as the ingredient in a) above, a sodium tripolyphosphate (STPP) comprising moisturized granules of essentially phase II STPP containing no more than about 5% by weight of phase I sodium tripolyphosphate which yields a non-caking, free flowing detergent formulation when added to water in the absence of agitation, said STPP produced by:
• e) forming granules of anhydrous, essentially phase II STPP by heating of sodium orthophosphate salts,
• f) contacting the STPP granules with water so that the STPP granules contain bound water in amounts of from about 3% to about 10% by weight,
• g) drying the wetted STPP granules from f) at a temperature of about 60.degree. C. to about 80.degree. C. to expel unbound water but not the bound water, so that no more than 0.5% of unbound water is present, and
• h) recovering the moisturized and dried, essentially phase II granules from g) containing no more than about 5% by weight of phase I sodium tripolyphosphate.