NEW CLEANING METHOD, APPARATUS AND USE

Abstract

A method for cleaning a substrate which is or comprises a textile, the method comprising agitating the substrate in the presence of a cleaning composition comprising: i. cleaning particles comprising a thermoplastic polyamide and a particulate inorganic filler having a density of at least 2.5 g/cm.sup.3, said cleaning particles having an average particle size of from 1 to 100 mm, wherein the cleaning particles have an average density of at least 1.65 g/cm.sup.3 and/or the particulate inorganic filler has a D.sub.50 particle size of at least 10 microns and/or a D.sub.90 particle size of at least 40 microns; and ii. a liquid medium.

Claims

1. A method for cleaning a substrate which is or comprises a textile, the method comprising agitating the substrate in the presence of a cleaning composition comprising: i. cleaning particles comprising a thermoplastic polyamide and a particulate inorganic filler having a density of at least 2.5 g/cm.sup.3, said cleaning particles having an average particle size of from 1 to 100 mm, wherein the cleaning particles have an average density of at least 1.65 g/cm.sup.3 and/or the particulate inorganic filler has a D.sub.50 particle size of at least 10 microns and/or a D.sub.90 particle size of at least 40 microns; and ii. a liquid medium.

2. A method according to claim 1 wherein the particulate inorganic filler has a D.sub.50 particle size of at least 10 microns and a D.sub.90 particle size of at least 40 microns.

3. A method according to claim 1 wherein the cleaning particles have an average density of at least 1.65 g/cm.sup.3 and the particulate inorganic filler has a D.sub.50 particle size of at least 10 microns and a D.sub.90 particle size of at least 40 microns.

4. A method according to claim 1 wherein the particulate inorganic filler has a D.sub.50 particle size of from 10 to 50 microns.

5. A method according to claim 4 wherein the particulate inorganic filler has a D.sub.50 particle size of from 10 to 25 microns.

6. A method according to claim 1 wherein the particulate inorganic filler has a D.sub.90 particle size of from 40 to 120 microns.

7. A method according to claim 1 wherein the particulate inorganic filler has a particle size distribution such that the span is at least 2.5.

8. A method according to claim 1 wherein the cleaning particles have an average density of at least 1.9 g/cm.sup.3.

9. A method according to claim 1 wherein cleaning particles have an average density of no more than 5.0 g/cm.sup.3.

10. A method according to claim 9 wherein the cleaning particles have an average density of no more than 2.5 g/cm.sup.3.

11. A method according to claim 1 wherein the particulate inorganic filler has a density of no more than 10 g/cm.sup.3.

12. A method according to claim 1 wherein the particulate inorganic filler has a density of at least 4 g/cm.sup.3.

13. A method according to claim 1 wherein the particulate inorganic filler is or comprises one or more fillers selected from a metal salt, a metal oxide, a metal sulfide, a metal carbide, a metal nitride, a ceramic, a metal, an alloy and combinations thereof.

14. A method according to claim 13 wherein the particulate inorganic filler is or comprises a metal salt, a metal oxide or a metal sulfide.

15. A method according to claim 14 wherein the particulate inorganic filler is or comprises barium sulfate and/or zinc sulfide.

16. A method according to claim 1 wherein the cleaning particles comprise at least 55 wt % of particulate inorganic filler.

17. A method according to claim 1 wherein the cleaning particles comprise no more than 80 wt % of particulate inorganic filler.

18. A method according to claim 1 wherein the thermoplastic polyamide is or comprises an aliphatic polyamide.

19. A method according to claim 18 wherein the aliphatic polyamide is or comprises Nylon 6, Nylon 6,6 or a mixture thereof.

20. A method according to claim 1 wherein the cleaning particles are in the form of a sphere, ellipsoid, cylinder and/or cuboid, and preferably in the form of a sphere and/or ellipsoid.

21. A method according to claim 1 wherein the cleaning particles have an average particle size of from 1 to 10 mm.

22. A method according to claim 1 wherein the liquid medium is or comprises water.

23. A method according to claim 1 wherein the substrate is in the form of towels, clothes, sheets, footwear or bags.

24. A method according to claim 1 wherein the textile is or comprises one or more fibres made of wool, cellulose, silk, nylon, polyester or acrylic.

25. A method according to claim 1 wherein the cleaning particles are re-used in further cleaning procedures according to the method.

26. A method according to claim 1 wherein the cleaning particle have an aspect ratio, in order of less than or equal to 1.20.

27. An apparatus suitable for performing the method according to claim 1 comprising a rotatable cleaning chamber and a particle storage tank containing the cleaning particles.

28. An apparatus according to claim 27 which comprises one or more of the following components: i. a controller; ii. a display; iii. a solenoid valve; iv. a pneumatic valve.

29. An apparatus according to claim 27 wherein the rotatable cleaning chamber is a drum provided with perforations which allow the cleaning particles to pass through the drum.

30. An apparatus according to claim 27 which additionally comprises a pump for transferring the cleaning particles into the cleaning chamber.

31. (canceled)

Description

EXAMPLES

1. Preparation of Cleaning Particles

1.1 Materials

[0098] The following materials were used to prepare the cleaning particles:

[0099] Ultramid® B40 which is a thermoplastic polyamide (Nylon-6) obtained from BASF SE having a viscosity number of 250 ml/g.

[0100] Ultramid® C33 which is a thermoplastic polyamide (a copolyamide of Nylon-6; Nylon-6,6) obtained from BASF SE having a viscosity number of 195 ml/g.

[0101] Ultramid® B27 is a thermoplastic polyamide (Nylon-6) obtained from BASF SE having a viscosity number of 150 ml/g.

[0102] The viscosity numbers were measured according to DIN ISO307 in all cases. The solvent is preferably 96% sulphuric acid.

[0103] Blanc Fixe® N is barium sulfate obtained from Sachtleben. This is used in the examples as the particulate inorganic filler. The density of this material is approximately 4.5 g/cm.sup.3.

[0104] Portaryte® D.sub.150 is barium sulfate obtained from Sibelco. The density of this material is approximately 4.5 g/cm.sup.3.

[0105] Portaryte® B40/10 is barium sulfate obtained from Sibelco. The density of this material is approximately 4.5 g/cm.sup.3.

[0106] The particle size distribution of the barium sulfate fillers have been measured by laser diffraction (Fraunhofer diffraction) using a Mastersizer 3000 from Malvern. The barium sulfate samples were dispersed in distilled water and dispersed by ultrasonication for 30 seconds. The particle size characteristics of the different barium sulfate fillers were as indicated in Table A. The particle sizes are volume-based.

TABLE-US-00001 TABLE A Particle size characteristics of different barium sulfate materials D.sub.(V, 10) (μm) D.sub.(V, 50) (μm) D.sub.(V, 90)(μm) Span Blanc Fixe ® N 1.7 5.8 13.2 1.98 Portaryte ® B40/10 8.8 15.8 26.5 1.12 Portaryte ® D150 2.0 13.3 65.9 4.80

1.2 Extrusion

[0107] The thermoplastic and particulate inorganic filler were mixed and extruded using a twin-screw extruder at a melt temperature of from 270 to 340° C. The particulate inorganic filler was metered in using a side feed with a gravimetric metering balance. The twin-screw extruder was used to extrude the melt into a cutting chamber containing water as the liquid coolant. The cutting speeds and extrusion pressures were adjusted to obtain the desired average cleaning particle size of around 4 mm (measured as described herein). The extrusion method was as described in WO2004/080679 in Example 1.

[0108] A range of cleaning particles was prepared using different thermoplastics and different particulate inorganic fillers in different amounts as specified in Tables 1 and 2. In Tables 1 and 2 all amounts were in wt %.

[0109] In Tables 1 and 2 the average particle size and the average density refer to the cleaning particles resulting from the extrusion and were measured by the methods as previously described. The shape of the cleaning particles prepared by extrusion was visually assessed for undesirable characteristics such as snake skinning, tails, cutting edges and particle to particle non-uniformity.

TABLE-US-00002 TABLE 1 Comparative Example A Example A Example B Example C Example D Sample GM0951/12/12 GM0951-12-11 GMO951/16/03 GM0951/16/04A GM0951/16/04 Ref No Ultramid ® 100 — — — — B40 Ultramid ® — — 40 35 30 B27 Ultramid ® — 50 — — — C33 Blanc — 50 60 65 70 Fixe ® N Portaryte ® — — — — — D150 Portaryte — — — — — B40/10 Shape Excellent Excellent OK OK OK Aspect 1.172 1.14 1.280 1.505 1.372 ratio MFR 16.22 34.28 31.28 20.41 Average 4.009 4.008 4.622 4.623 4.333 particle size (mm) Average 1.13 1.78 2.01 2.15 2.31 particle density (g/cm.sup.3)

TABLE-US-00003 TABLE 2 Example E Example F Example G Example H Example I Sample GM0951/16/05 GM0951/16/09 GMO951/16/06B GM0951/16/08A GM0951/16/28 Ref No Ultramid ® — — — — — B40 Ultramid ® 40 35 30 — 30 B27 Ultramid ® — — — 25 — C33 Blanc — — — — — Fixe ® N Portaryte ® 60 65 70 75 — D150 Portaryte ® — — — — 70 B40/10 Shape Excellent Excellent Excellent Excellent OK Aspect 1.048 1.086 1.10 1.162 1.26 ratio MFR 80.29 83.55 100.31 54.08 Average 4.19 4.29 4.300 4.647 3.94 particle size (mm) Average 1.98 2.10 2.15 2.39 2.11 particle density (g/cm.sup.3)

[0110] The assessment of the shape was done visually; the rating of “Excellent” corresponds to an ellipsoidal shape with an aspect ratio of <1.2, whilst the rating of “OK” corresponds to a more cylindrical shape with an aspect ratio of >1.2.

[0111] The density of the particles was measured using a pycnometer according to DIN ISO 1183-1:2012.

[0112] MFR is the Melt Flow Rate which is measured according to ISO 1133 at 260° C./5 Kg.

[0113] The aspect ratio was calculated using the preferred method mentioned above.

[0114] As can be seen in Tables 1 and 2 above the incorporation of a particulate inorganic filler having a density of at least 2.5 g/cm.sup.3 has provided cleaning particles with improved density characteristics.

[0115] Examples A to D in Table 1 all incorporate a particulate inorganic filler having a D.sub.50 particle size of less than 10 microns and a D.sub.90 particle size of less than 40 microns. It was shown that as the wt % of this smaller particle size filler approached and extended above 60 wt % the particle shape/size characteristics of the resulting cleaning particles became less optimal for laundry applications. In particular, these cleaning particles exhibited some degree of defects including: snake skinning, tails, cutting edges and particle to particle non-uniformity in shape and size and showed shapes which were far from the desired smooth ellipsoidal shape. As the weight incorporation of the filler increased the aspect ratio soon became undesirably higher than 1.2, indicating that the particles were becoming more cylindrical and less ellipsoidal. It was noted that the cleaning particles with undesirable shape characteristics using Blanc® Fixe N also demonstrated significant variations in melt pressure and melt flow. No attempts to produce better shapes by varying the extrusion and cutting parameters were successful.

[0116] Examples E to H in Table 2 all incorporate a particulate inorganic filler having a D.sub.50 particle size of at least 10 microns and having a D.sub.90 particle size of at least 40 microns. In addition to the desirable density results in Table 1 it was surprisingly possible to obtain cleaning particles with wt % incorporation of the particulate inorganic filler which approached or exceeded 60 wt % and which had excellent shape characteristics. That is to say Examples E to H had smooth ellipsoidal shapes which were substantially free from snake skinning, tails, cutting edges and were uniform in shape and size. The improved ellipsoidal shape is evident from the improved aspect ratios of the cleaning particles which are all <=1.2. Thus, particles having the more desired shape and density characteristics for laundry applications were even better achieved.

[0117] Example I in Table 2 incorporates a particulate inorganic filler having a D.sub.50 particle size of at least 10 micron and having a D.sub.90 particle size of less than 40 microns. As can be seen the particle shape characteristics are intermediate between those of Examples A to D in Table 1 and those of Examples E to H in Table 2.

2 Cleaning

2.1 Cleaning Examples and Methods

[0118] The following cleaning particles as prepared in part 1 above were selected for cleaning experiments: Comparative Example A and Example G.

[0119] The cleaning experiments were triplicated for each cleaning particle using a Xeros washing apparatus as described in PCT patent publication WO 2011/098815 with a recommended dry laundry loading of 25 kg. The washing cycle was carried out using 20 kgs of a cotton flatware ballast. The washing cycle was run for 60 minutes at a temperature of 20° C. or 70 minutes at a temperature of 40° C. and using an 250 gms of Pack 1 cleaning formulation supplied by Xeros Ltd. 69 m.sup.2 of surface area of cleaning particles were used in all cases. The liquid medium was water. The cleaning particles were recycled through the cleaning apparatus during the washing cycle for 10 minutes of the washing cycle for the 20° C. temperature and for 15 minutes of the washing cycle for the 40° C. temperature.

[0120] After each cleaning cycle the wash load was rinsed and the washing apparatus performed a separation cycle for a period of 30 minutes (both rinse and separation cycles).

[0121] To test the cleaning performance 5×WFK (Ref No PCMS-55 05-05x05) stain test sheets obtained from WFK Testgewebe GmbH were used for each type of cleaning particles in each of the triplicated cleaning experiments. The L*, a*, b* values of each stain were measured before and after cleaning using a spectrophotometer. For each type of cleaning particle the average delta E value was calculated according to CIE76.

2.2 Cleaning Results

[0122]

TABLE-US-00004 TABLE 3 Cleaning results Average Average Average Average Average Average delta E delta E delta E delta E delta E delta E Cleaning (all stains) (all stains) (sebum) (oil/soot) (sebum) (oil/soot) Particles 20° C. 40° C. 20° C. 20° C. 40° C. 40° C. Comparative 15.73 17.46 16.38 10.59 19.18 12.43 Example A Example G 15.79 17.93 17.05 10.72 19.66 13.03

[0123] As can be seen the cleaning results were superior when the method of the present invention was performed using the cleaning particles of Example G as opposed to Comparative Example A.

3 Separation

3.1 Separation Examples and Method

[0124] The following cleaning particles as prepared in part 1 above were selected for separation experiments: Comparative Example A, Example A and Example G.

[0125] The separations experiments were repeated 5 times for each cleaning particle using a Xeros washing apparatus as described in PCT patent publication WO 2011/098815 with a recommended dry laundry loading of 25 kg. The washing cycle was carried out using 20 kgs of a ballast comprising long sleeved shirts each having a single pocket on the front. The washing cycle was run for 60 minutes at a temperature of 20° C. and using an 100 gms of Pack 1 cleaning formulation obtained from Xeros Ltd. 69 m.sup.2 of surface area of cleaning particles were used in all cases. The liquid medium was water. The cleaning particles were recycled through the cleaning apparatus during the washing cycle for a total of 10 minutes.

[0126] In every case the wash load was rinsed and the separation cycle was run for 30 minutes (for both rinse and separation cycles).

[0127] After the end of the separation cycle each item of the ballast was taken out and any remaining (unseparated) cleaning particles were shaken into a large container. Once all the ballast had been shaken to remove all the cleaning particles the cleaning particles were dried and then counted. An average number of unseparated particles was calculated for all of the 5 washing experiments using each type of cleaning particle. The results are described in Table 4.

TABLE-US-00005 TABLE 4 Separation results Cleaning particles Average number of particles unseparated Comparative Example A 604.0 Example A 442.6 Example G 249.2

[0128] As can be seen the separation results for the cleaning particles in Examples A and G using the method of the present invention were far superior to those obtained for the cleaning particles in Comparative Example A. This is highly desirable as the end user has far fewer unseparated cleaning particles to remove from the final wash.

[0129] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. Thus for example, a substrate means one or more substrates, similarly a cleaning composition means one or more cleaning compositions and a particulate inorganic filler means one or more particulate inorganic fillers.

[0130] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0131] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.