Manufacture of free-flowing particulate heavy duty synthetic detergent composition containing nonionic detergent and anti-redeposition agent

Claim 3

A method according to claim 1 wherein the detergent builder salt is a sodium salt, the particulate intermediate composition contains less than 0.3 percent by weight of an anti-redeposition agent selected from the group consisting of sodium carboxymethyl cellulose, polyvinyl alcohol, methyl cellulose, hydroxypropyl methyl cellulose, polyvinyl pyrrolidone and polymeric acrylamide, said intermediate detergent composition is produced by spray drying of an aqueous composition containing such detergent builder salt or mixture thereof, from 0.5 to 5 percent by weight of the synthetic organic gum anti-redeposition agent, in finely divided powder form, is mixed with the intermediate detergent composition, and from 2 to 6 percent by weight of the nonionic detergent, which is normally solid or semi-solid, is sprayed onto the intermediate detergent composition and is cooled thereon to form a free-flowing particulate synthetic detergent composition having soil anti-redeposition agent held thereto.

Claim 4

A method according to claim 2 wherein the mixing of the intermediate detergent composition particles and the finely divided synthetic organic gum anti-redeposition agent powder and the spraying onto the mixture of the nonionic detergent is continuous, the detergent particles and anti-redeposition agent are at about room temperature, the nonionic detergent is at an elevated temperature in the range of 40* to 90* C. and the temperature difference and the quantities of detergent composition constituents are such as to cool the nonionic detergent to solid or semi-solid form due to heat being extracted therefrom by the intermediate detErgent composition particles and the anti-redeposition agent powder.

Claim 5

A method according to claim 2 wherein the free-flowing particulate synthetic detergent composition comprises by weight from 15 to 50 percent of the detergent builder salt, 5 to 65 percent of sodium sulfate, 2 to 8 percent of the nonionic detergent, 0.5 to 5 percent of the synthetic organic anti-redeposition agent and 3 to 15 percent of moisture, spray drying of the intermediate detergent composition is from a crutcher mix containing from 25 to 65 percent by weight of water, none of the anti-redeposition agent and no more than a proportion of the nonionic detergent which results in a final composition content of 2 percent by weight of said crutcher-mix derived nonionic detergent, the nonionic detergent sprayed onto the intermediate detergent composition is a higher alkoxy poly-lower alkoxy alkanol in which the higher alkoxy is of 12 to 18 carbon atoms and the poly-lower alkoxy alkanol contains three to 15 ethoxy groups, the temperature of the nonionic detergent when it is sprayed onto the surfaces of the particles of intermediate detergent composition and anti-redeposition agent is from 40* to 90* C. at which temperature the nonionic detergent is liquid, and said spraying is conducted while tumbling the spray dried particles to present new surfaces thereof to the liquid being sprayed onto them.

Claim 6

A method according to claim 4 wherein the detergent builder salt is selected from the group consisting of sodium silicate of Na2O:SiO2 ratio in the range of 1:1.6 to 1:3 and mixtures of at least 5 percent by weight thereof, on a final product basis, with the other detergent builder salt or salts of claim 4, the sprayed intermediate detergent composition particles and the final detergent composition particles are substantially all within the 6 to 140 mesh, U.S. Standard Sieve Series range, the particles of anti-redeposition agent are of a size in the 100 to 200 mesh range, the spray of the nonionic detergent is at a temperature of 50* to 70* C. and the particles thereof in atomized form are in the 5 micron to 2 millimeters diameter range, and the powdered anti-redeposition agent is mixed with the spray dried intermediate detergent composition beads before spraying the nonionic detergent onto the surfaces of the particles of such mixture.

Claim 7

A method according to claim 5 wherein the sodium silicate is of Na2O:SiO2 ratio in the range of 1:2 to 1:2.7, the spray dried intermediate detergent composition particles contain 5 to 35 percent by weight of a water soluble anionic sulf(on)ate synthetic organic detergent salt having a higher linear alkyl chain therein, the anti-redeposition agent is sodium carboxymethyl cellulose, the nonionic detergent sprayed onto the surfaces of the mixture of anti-redeposition and spray dried intermediate detergent composition particles is substantially anhydrous and is semi-solid at room temperature, and after the mixing of the intermediate detergent composition and anti-redeposition agent particles and spraying thereon of the nonionic detergent, there is blended with the resulting product from 1/4 to 4 percent by weight of a material selected from the group consisting of finely divided clay and pyrogenic silica to improve the flow properties of the detergent composition.

Claim 8

A method according to claim 6 wherein the sodium silicate is of Na2O:SiO2 ratio of about 1:2.35, the anionic detergent is sodium linear higher alkyl benzene sulfonate in which the higher alkyl group is of 12 to 14 carbon atoms, the spray dried intermediate detergent composition particles and the final product particles contain from 1 to 6 percent of sodium higher fatty acid soap, sprAy dried from the same slurry as the other constituents of the intermediate detergent composition particles, the nonionic detergent is one in which the higher alkoxy is of 12 to 15 carbon atoms and which contains from 7 to 15 ethoxy groups, and the flow-improving agent is calcined aluminum silicate and from 1/2 to 2 percent thereof is present in the final composition.

Claim 9

A method according to claim 7 wherein the mixing of the intermediate detergent composition particles and the finely divided synthetic organic gum anti-redeposition agent powder and the spraying onto the mixture of the nonionic detergent is continuous, the detergent and anti-redeposition agent are at about room temperature, the nonionic detergent temperature and the temperature difference and quantities of detergent composition constituents are such as to cool the nonionic detergent to solid or semi-solid form due to heat being extracted therefrom by the intermediate detergent composition particles and the anti-redeposition agent powder on them, the continuous mixing and spraying are effected in a tumbling drum and flow-improving agent is added near the end of passage of materials through the drum.

Claim 12

A method according to claim 9 wherein the particulate intermediate composition is made by spray drying a crutcher mix of, by weight, about 1,915 parts of sodium linear dodecyl benzene sulfonate, about 3,067 parts of an about 43.5 percent solids aqueous sodium silicate solution wherein the Na2O:SiO2 ratio equals about 1:2.35, about 1,896 parts of anhydrous sodium sulfate, about 107 parts of RO(CH2CH2O)nCH2CH2OH, wherein R is primary alkyl of about 14 to 15 carbon atoms and n equals about 10, about 469 parts of an about 70 percent solids sodium coconut-tallow kettle soap wherein the coconut-tallow ratio is about 20: 80 and about 491 parts of water to produce spray dried detergent beads of a density of about 0.3 gram/milliliter, a moisture content of about 9 percent and a particle size of about 8 to 100 mesh, U.S. Standard Sieve Series, with less than about 5 percent of the product passing through a 100 mesh sieve, and tumbling such product in a tumbling cylinder inclined at an anGle of about 8* from the horizontal at a speed of about 15 revolutions per minute, admixing with the spray dried detergent powder while it is being tumbled about 3/94.85 of the weight thereof of sodium carboxymethyl cellulose of about 65 percent activity, in finely divided form, with particles in the 100 to 200 mesh range and, after mixing thereof, spraying onto the surfaces of the tumbling particles about 2/94.85 of the weight of the spray dried detergent powder of RO(CH2CH2O)n-CH2CH2OH in liquid state at a temperature of about 50* C., in atomized form with particles thereof in the 5 microns to 2 millimeters diameters range, with substantially all of the particles being in the 10 microns to 1 millimeter diameter range, while maintaining the drum about 1/10 full of tumbling particles during operation thereof, to produce a product which contains, by weight, about 18 percent of the sodium linear dodecyl benzene sulfonate, about 37 percent of sodium sulfate, about 25 percent of sodium silicate, about 4 percent of ethoxylated higher alkanol, about 6 percent of soap, about 2 percent of sodium carboxymethyl cellulose, as active ingredient, and about 8 percent of moisture, which is free-flowing, non-tacky and of a bulk density of about 0.3 g./ml.