Laundry detergent compositions
The present invention is to a laundry detergent powder comprising: (i) from 20 to 80 wt % of a first particle comprising less than 55 wt % sulphate, anionic detersive surfactant, and having a bulk density of from 300 g/l to 1100 g/l: and (ii) from 20 to 80 wt % of a second particle comprising at least 55 wt % sulphate and, having a bulk density of from 350 g/l to 600 g/l, and a process to making the laundry detergent powder.
1. A laundry detergent powder comprising:
(i) from about 20 to about 80 wt % of a first particle comprising less than about 55 wt % sulphate, at least about 30 wt % anionic detersive surfactant, between 15 wt % and about 20 wt % silicate, between about 10 wt % and about 40 wt % carbonate, between about 1.5 wt % and 3 wt % of a first polymer, and wherein the first particle is an agglomerate particle having a bulk density of from about 700 g/l to about 1100 g/l: and
(ii) from about 20 to about 80 wt % of a second particle comprising at least about 55 wt % sulphate, between about 1 wt % and about 12 wt % anionic detersive surfactant, between about 1 wt % and about 5 wt % silicate, between about 1 wt % and 8 wt % of a second polymer, and having a bulk density of from about 350 g/l to about 600 g/l;
wherein the first particle and the second particle are both essentially free of zeolite builder and essentially free of phosphate builder, wherein the first and second polymer are selected from the group consisting of a polyacrylate homopolymer and an acrylic acid/maleic acid copolymer.
2. The laundry detergent powder according to claim 1 , wherein the second particle is a spray-dried particle or flash-dried particle.
3. The laundry detergent powder according to claim 1 , wherein the first particle has a mean particle size of between about 350 and about 650 μm, and the second particle has a mean particle size of between about 350 and about 650 μm.
4. The laundry detergent powder according claim 1 , comprising from about 50% to about 80% by weight of the laundry detergent powder of the first particle and from about 20% to about 50% by weight of the laundry detergent powder of the second particle.
5. The laundry detergent powder according to claim 1 wherein the first particle, the second particle or both particles further comprise a co-polymer comprising:
(i) from about 50 to less than about 98 wt % structural units derived from one or more monomers comprising carboxyl groups;
(ii) from about 1 to less than about 49 wt % structural units derived from one or more monomers comprising sulfonate moieties; and
(iii) from about 1 to about 49 wt % structural units derived from one or more types of monomers selected from ether bond-containing monomers represented by formulas (I) and (II):
wherein in formula (I), R 0 represents a hydrogen atom or CH 3 group, R represents a CH 2 group, CH 2 CH 2 group or single bond, X represents a number 0-5 provided X represents a number 1-5 when R is a single bond, and R 1 is a hydrogen atom or C 1 to C 20 organic group;
in formula (II), R 0 represents a hydrogen atom or CH 3 group, R represents a CH 2 group, CH 2 CH 2 group or single bond, X represents a number 0-5, and R 1 is a hydrogen atom or C 1 to C 20 organic group.
6. The laundry detergent powder according to claim 1 , wherein the anionic detersive surfactant in the first particle is linear alkylbenzene sulfonic acid or a salt thereof, alkyl ethoxylated sulphate or a mixture thereof.
7. The laundry detergent powder according to claim 1 , wherein the first particle further comprises a cellulosic polymer.
8. The laundry detergent powder according to claim 7 , wherein the cellulosic polymer is selected from the group consisting of alkyl cellulose, alkyl alkoxyalkyl cellulose, carboxylalkyl cellulose, alkyl carboxyalkyl cellulose and a mixture thereof.
9. The laundry detergent powder according to claim 1 , wherein the first particle further comprises a brightener.
10. A method for making the laundry detergent powder according to claim 1 , comprising the steps of:
a) agglomerating the components of part (i) to make the first particle;
b) preparing an aqueous slurry comprising the components of part (ii) and water, and drying the aqueous slurry by spray-drying or flash-drying to make the second particle;
c) combining the first and second particles to produce the laundry detergent powder.
11. The method according to claim 10 , wherein the sulphate added to the aqueous slurry in step (b) has a volume average particle size of from about 10 micrometers to about 50 micrometers.
12. The method according to claim 11 wherein the sulphate added to the aqueous slurry in step (b) has a volume average particle size of from about 20 micrometers to about 45 micrometers.
13. The method according to claim 12 wherein the sulphate added to the aqueous slurry in step (b) has a volume average particle size of from about 30 micrometers to about 42 micrometers.
14. The method according to claim 10 , wherein the sulphate added in step (a) has a volume average particle size of from about 10 micrometers to about 50 micrometers.
15. The method according to claim 14 , wherein the sulphate added in step (a) has a volume average particle size of from about 20 micrometers to about 45 micrometers.
16. The method according to claim 15 , wherein the sulphate added in step (a) has a volume average particle size of from about 30 micrometers to about 42 micrometers.