GRANULATE FOR DETERGENT COMPOSITION COMPRISING NITROGEN-CONTAINING BUILDERS

Abstract

A granulate for a detergent composition, the granulate comprising a nitrogen-containing builder, wherein the granulate is at least partially coated with a coating material comprising an alkoxy polyalkylene glycol.

Claims

1. A granulate for a detergent composition, the granulate comprising a nitrogen-containing builder, wherein the granulate is at least partially coated with a coating material comprising an alkoxy polyalkylene glycol.

2. The granulate according to claim 1, wherein the alkoxy group of the alkoxy polyalkylene glycol is represented by the formula RO wherein R is a C.sub.1 to C.sub.20 alkyl group.

3. The granulate according to claim 1, wherein the polyalkylene glycol of the alkoxy polyalkylene glycol is selected from the group consisting of a polyethylene glycol, a polypropylene glycol, a polybutylene glycol, and combinations of two or more thereof.

4. The granulate according to claim 1, wherein the alkoxy polyalkylene glycol is a methoxy polyethylene glycol.

5. The granulate according to claim 1, wherein the alkoxy polyalkylene glycol has a weight average molecular weight of from 200 to 500 g/mol.

6. The granulate according to claim 1, wherein the alkoxy polyalkylene glycol is a liquid at 25° C.

7. The granulate according to claim 1, wherein the nitrogen-containing builder comprises an aminocarboxylate.

8. The granulate according to claim 1, wherein the granulate and the coating material are present in a weight ratio of from 20:1 to 200:1

9. A method of preparing a granulate for a detergent composition, the method comprising: (i) providing particles comprising a nitrogen-containing builder; and (ii) at least partially coating the particles with a coating material comprising an alkoxy polyalkylene glycol.

10. The method according to claim 9, wherein the step of at least partially coating the particles with a coating material comprising an alkoxy polyalkylene glycol comprises spray-coating the particles with an alkoxy polyalkylene glycol in liquid form.

11. A detergent composition comprising the granulate according to claim 1.

12. The detergent composition according to claim 11, wherein the detergent composition is an automatic dishwashing composition or a laundry detergent composition.

13. The detergent composition according to claim 11, wherein the composition further comprises a bleaching agent.

14. The detergent composition according to claim 1, wherein the detergent composition is in the form of a solid.

15. The detergent composition according to claim 1, wherein the nitrogen-containing builder is present in an amount of from 5 to 50 wt % by weight of the detergent composition, and/or the detergent composition comprises a bleaching agent in an amount of from 1 to 50 wt % by weight of the detergent composition.

16. The detergent composition according to claim 1, wherein the composition is storage stable for at least 12 weeks at 40° C. and 75% relative humidity.

17. A detergent product comprising the detergent composition according to claim 11.

18. The detergent product according to claim 17, wherein the product is: in a unit dose form; and/or housed within a water soluble or water dispersible film or container, preferably a polyvinyl alcohol film or container.

19. A method of using a detergent composition according to claim 11 in an automatic dishwashing process or a laundry process.

20. A method of using a coating material comprising an alkoxy polyalkylene glycol to reduce the yellowing of a nitrogen-containing builder in a detergent composition.

Description

EXAMPLE 1

[0080] A three-compartment PVOH pouch was filled with a powder automatic dishwashing (ADW) composition, a liquid ADW composition and a gel ADW composition. The resulting product (Product A, not in accordance with the invention) contained an uncoated granulate of MGDA and disilicate containing at least 70 wt % of the aminocarboxylate, from 2 to 10 wt % of the disilicate and less than 20 wt % of water. The granulate was supplied by PQ Corporation, and was blended into the base powder composition. A second product was also made (Product B, in accordance with the invention), in which the uncoated granulate of Product A was replaced with the same granulate coated with a liquid methoxy polyethylene glycol (MPEG 350 NG, supplied by Ineos).

TABLE-US-00001 The powder composition of Product A was as follows: Component Amount (wt %) MGDA/disilicate granulate 32.5 Sodium percarbonate coated 22.0 Sodium carbonate 18.7 Phosphonate cobuilder 9.5 Enzymes 8.6 Polymers/surfactants 8.2 Fragrance 0.5 Total 100.0 wt %

[0081] The liquid phase of Product A contained a surfactant and a dye.

[0082] The gel phase of Product A contained a co-builder, a bleach activator, a corrosion inhibitor, and further surfactants/polymers.

[0083] Product B was identical to Product A, except the 32.5 wt % uncoated MGDA/disilicate granulate in the powder was replaced with 32.5 wt % coated MGDA/disilicate granulate in accordance with the invention.

Preparation of Coated Granulate

[0084] To apply the methoxy polyethylene glycol, the uncoated granulate was placed in a kitchen mixing machine and 1 wt % of a liquid MPEG (MPEG 350 NG) was sprayed on using a pumping atomizer bottle while mixing. This mixture was then placed in an oven and dried at 50° C. for approximately 1 hour. The dried, coated granulate was then blended into the base powder formulation in the same manner as for Product A.

Product Storage

[0085] After the PVOH pouches were filled and sealed, Product A and Product B were placed into doy packs and stored in a controlled climate chamber at 40° C. and 75% relative humidity (r.h.). Visual comparisons of Product A and Product B were conducted at regular time intervals.

Product Analysis

[0086] In order to evaluate the yellowing of samples, a panel of evaluators was selected and a triangle test was conducted.

[0087] Set-up: For the triangle test a panel of 24 independent assessors was selected and each assessor was presented with one of the six sample sequences ABB, AAB, ABA, BAA, BBA, BAB simultaneously. Next the assessors were informed that two of the samples are the same and that one is different. Each panellist should then indicate which of the three samples is different from the other two. Additionally, each panellist was then asked to indicate whether the selected sample was looking better or worse than the other two identical samples.

[0088] Results after 6 weeks' storage at 40° C./75% r.h.: Of the 24 assessors, 17 correctly identified the unique sample within each triad. This is sufficient to establish at a <0.05 risk level that the two sample types are perceptibly different. Moreover, all 17 correct answers were able to indicate if the selected odd sample was looking better or worse than the two other identical samples. Accordingly, it was found that the powder component of Product A was perceptibly more yellow than the powder component of Product B.

[0089] Results after 12 weeks' storage at 40° C./75% r.h.: Of the 24 assessors, 15 correctly identified the unique sample within each triad. This is sufficient to establish at a <0.05 risk level that the two sample types are perceptibly different. Moreover, all 15 correct answers were able to indicate if the selected odd sample was looking better or worse than the two other identical samples. Accordingly, it was found that the powder component of Product A was perceptibly more yellow than the powder component of Product B.

[0090] Taking these results together provides strong evidence that a difference between the benchmark (base powder+uncoated MGDA/disilicate granulate) and the inventive composition (base powder+MGDA/disilicate granulate coated with 1 wt % MPEG 350NG) was apparent after storage for 6 weeks and 12 weeks at 40° C. and 75% r.h.

[0091] In conclusion, coating a granulate comprising an nitrogen-containing builder with an alkoxy polyalkylene glycol was found to significantly reduce the yellowing of the nitrogen-containing builder in the presence of a bleaching agent (sodium percarbonate) at elevated temperatures and moisture levels over prolonged storage periods.

[0092] The foregoing detailed description has been provided by way of explanation and illustration, and is not intended to limit the scope of the appended claims. Many variations in the presently preferred embodiments illustrated herein will be apparent to one of ordinary skill in the art, and remain within the scope of the appended claims and their equivalents.