Sodium phosphate composition and process

Claim 2

A particulate solid hydrated phosphate composition comprising trisodium phosphate and sodium hydroxide with the atomic ratio of Na:P:OH being 3.1-3.2:1:0.1-0.2, and the overall P:H 2 O ratio of 1:8-11, the solid composition having an outer layer comprising trisodium phosphate hexahydrate and a core containing trisodium phosphate dodecahydrate and sodium hydroxide.

Claim 3

A phosphate composition according to claim 1 of particle size 0.25-1 mm.

Claim 4

A phosphate composition according to claim 1 or 2, wherein the overall P:H 2 O ratio is 1:10-11.

Claim 5

A phosphate composition according to claim 1 or 2 wherein the ratio of Na:P:OH is 3.12-3.18:1:0.12-0.18.

Claim 6

A phosphate composition according to claim 3 wherein the ratio of Na:P:OH is 3.12-3.18:1:0.12-0.18.

Claim 7

A particulate solid hydrated phosphate composition comprising trisodium phosphate and a sodium compound of formula NaX, wherein X is selected from hydroxyl and a monovalent inorganic anion Z, which is derived from a monobasic inorganic acid HZ and mixtures thereof with the atomic ratio of Na:P:X being 3.1-3.2:1:0.1-0.2, and the atomic ratio P:Z:OH being 1: up to 0.2: up to 0.2 and the overall P:H 2 O ratio of 1:8-11, the solid composition having an outer layer comprising trisodium phosphate hexahydrate and a core containing trisodium phosphate dodecahydrate and the sodium compound.

Claim 8

A particulate solid hydrated phosphate composition comprising trisodium phosphate and a sodium compound of formula NaX, wherein X is selected from hydroxyl and a monovalent inorganic anion Z, which is derived from a monobasic inorganic acid HZ and mixtures thereof with the atomic ratio of Na:P:X being 3.1-3.2:1:0.1-0.2, and the atomic ratio P:Z:OH being 1: up to 0.2: up to 0.2 and the overall P:H 2 O ratio of 1:8-11, the solid composition having an outer layer comprising trisodium phosphate hexahydrate and a core containing trisodium phosphate dodecahydrate and the sodium compound.

Claim 9

A phosphate composition according to claim 6 wherein the atomic ratio of P:Z:OH is 1:0.01-0.2:0-0.19.

Claim 10

A phosphate composition according to claim 7 wherein the atomic ratio of P:Z:OH is 1:0.1-0.15:0-0.04.

Claim 11

A phosphate composition according to claim 6 or 8 of average particle size 0.25-1 mm.

Claim 12

A solid cleanser composition comprising a solid particulate sodium phosphate composition according to claim 1 or 6 together with sodium sesquicarbonate.

Claim 13

A composition according to claim 10 also comprising an abrasive.

Claim 14

A process for preparing a particulate solid hydrated phosphate composition wherein an aqueous solution at 90°-120° C. of trisodium phosphate and sodium hydroxide, wherein the atomic ratio of Na:P:OH is 3.1-3.2:1:0.1-0.2 and a P:H 2 O ratio of 1:10-14 is formed into droplets and rapidly chilled substantially out of contact with one another by countercurrent contact with air to produce particles of an intermediate body with a solid outer layer of trisodium phosphate hexahydrate enclosing a core comprising aqueous medium comprising trisodium phosphate and sodium hydroxide and then said particles of the intermediate body are cooled further to give a solid phosphate composition of overall P:H 2 O ratio of 1:8-11 having a solid outer layer comprising trisodium phosphate hexahydrate and a solid core containing trisodium phosphate dodecahydrate and sodium hydroxide.

Claim 15

A process for preparing a particulate solid hydrated phosphate composition wherein an aqueous solution at 90°-120° C. of trisodium phosphate and sodium hydroxide, wherein the atomic ratio of Na:P:OH is 3.1-3.2:1:0.1-0.2 and a P:H 2 O ratio of 1:10-14 is formed into droplets and rapidly chilled substantially out of contact with one another by countercurrent contact with air to produce particles of an intermediate body with a solid outer layer of trisodium phosphate hexahydrate enclosing a core comprising aqueous medium comprising trisodium phosphate and sodium hydroxide and then said particles of the intermediate body are cooled further to give a solid phosphate composition of overall P:H 2 O ratio of 1:8-11 having a solid outer layer comprising trisodium phosphate hexahydrate and a solid core containing trisodium phosphate dodecahydrate and sodium hydroxide.

Claim 16

A process according to claim 12 wherein particles of the intermediate body with a solid outer layer and a core comprising partly solidified aqueous medium are separated from said counter current air before being cooled further.

Claim 17

A process according to claim 12 or 13 wherein droplets of 0.1-2 mm size initially contact the countercurrent air, which has a temperature of les than 60° C., the particles of intermediate body have an average measured temperature of 70°-30° C. and are cooled to give the solid phosphate compositions at less than 30° C.

Claim 18

A process according to claim 13 or 14 wherein the particles of intermediate body are cooled further substantially out of contact with one another.

Claim 19

A process according to claim 15 wherein the particles of intermediate body are cooled further in an upward cocurrent stream of air.

Claim 20

A process according to claim 13 wherein droplets of 0.25-1 mm of said aqueous solution pass down a tower countercurrent to an upwardly moving air stream to give particles of intermediate body having an average temperature of 35°-50° C., said particles are then separated from said air stream and passed into an upwardly moving air stream in which they move cocurrently and are cooled to 15°-30° C. to produce said solid particulate phosphate composition.

Claim 21

A process according to claim 12 wherein said aqueous solution is prilled to give said particulate solid composition.

Claim 22

A process according to claim 14 wherein the particles of intermediate body aare cooled further substantially out of contact with one another.

Claim 23

A process for preparing a particulate solid hydrated phosphate composition wherein an aqueous solution at 90°-120° C. of trisodium phosphate and a sodium compound of formula NaX, where X is selected from hydroxyl and a monovalent inorganic anion Z, which is derived from a monobasic inorganic acid HZ and mixtures thereof with the atomic ratio of Na:P:X being 3.1-3.2:1:0.1-0.2 and the atomic ratio of P:Z:OH being 1: up to 0.2: up to 0.2 and the overall P:H 2 O ratio of 1:10-14 is formed into droplets and rapidly chilled substantially out of contact with one another by countercurrent contact with air to produce particles of an intermediate body with a solid outer layer of trisodium phosphate hexahydrate enclosing a core comprising aqueous medium comprising trisodium phosphate and sodium compound and then said particles of intermediate body are cooled further to give a solid phosphate composition of P:H 2 O ratio of 1:9-11 having an outer layer comprising trisodium phosphate hexahydrate and a core containing trisodium dodecahydrate and sodium hydroxide.

Claim 24

A process for preparing a particulate solid hydrated phosphate composition wherein an aqueous solution at 90°-120° C. of trisodium phosphate and a sodium compound of formula NaX, where X is selected from hydroxyl and a monovalent inorganic anion Z, which is derived from a monobasic inorganic acid HZ and mixtures thereof with the atomic ratio of Na:P:X being 3.1-3.2:1:0.1-0.2 and the atomic ratio of P:Z:OH being 1: up to 0.2: up to 0.2 and the overall P:H 2 O ratio of 1:10-14 is formed into droplets and rapidly chilled substantially out of contact with one another by countercurrent contact with air to produce particles of an intermediate body with a solid outer layer of trisodium phosphate hexahydrate enclosing a core comprising aqueous medium comprising trisodium phosphate and sodium compound and then said particles of intermediate body are cooled further to give a solid phosphate composition of P:H 2 O ratio of 1:9-11 having an outer layer comprising trisodium phosphate hexahydrate and a core containing trisodium dodecahydrate and sodium hydroxide.

Claim 25

A process according to claim 20 wherein said particles of the intermediate body with a solid outer layer and a core comprising partly solidified aqueous medium are separated from said counter current air before being cooled further.