Thixotropic Composition

Abstract

The invention concerns a thixotropic composition comprising a microcrystalline cellulose, a swelling or water binding agent, a starch glycolate, a solvent and carboxymethyl cellulose or its alkaline salt or its alkaline earth metal salt, wherein the swelling or water binding agent is a phyllosilicate, wherein the solvent comprises water.

Claims

1-18. (canceled)

19. A thixotropic composition comprising a microcrystalline cellulose, a swelling or water binding agent, a starch glycolate, a solvent, and carboxymethyl cellulose or its alkaline salt or its alkaline earth metal salt, wherein the swelling or water binding agent is mica, wherein the solvent comprises or consists of water, wherein a water content of the composition is at least 70% w/w, wherein the weight ratio of microcrystalline cellulose to carboxymethyl cellulose or its alkaline salt or its alkaline earth metal salt is in the range of 3:1 to 11:1 and/or the weight ratio of microcrystalline cellulose and carboxymethyl cellulose or its alkaline salt or its alkaline earth metal salt together to the swelling or water binding agent is in the range of 3:1 to 4:1.

20. The thixotropic composition according to claim 19, wherein water content of the composition is at least 80% w/w.

21. The thixotropic composition according to claim 19, wherein the mica is an aluminum fluoro magnesium sodium silicate, in particular aluminum fluoro magnesium sodium silicate having CAS Registry Number 12001-26-2.

22. The thixotropic composition according to claim 19, wherein the weight ratio of microcrystalline cellulose to carboxymethyl cellulose or its alkaline salt or its alkaline earth metal salt is in the range of 4:1 to 9:1 and/or the weight ratio of microcrystalline cellulose and carboxymethyl cellulose or its alkaline salt or its alkaline earth metal salt together to the swelling or water binding agent is in the range of 3.3:1 to 3.5:1.

23. The thixotropic composition according to claim 19, wherein the thixotropic composition further comprises a cellulose or an alkylcellulose, in particular methylcellulose, ethylcellulose, or ethyl methyl cellulose.

24. The thixotropic composition according to claim 19, wherein a dye and/or a chemical substance, in particular a pesticide, a drug or an insect repellent, is dissolved in the thixotropic composition and/or pigments, any particles having a diameter in the range of 1 to 100 μm, metal particles, nanocapsules and/or microcapsules are suspended in the thixotropic composition.

25. The thixotropic composition according to claim 24, wherein the metal particles are particles of a heavy metal, in particular copper, silver or zinc.

26. The thixotropic composition according to claim 25, wherein the metal particles are particles of silver having a diameter in the range of 1 to 100 μm and an arithmetic mean inner porosity of at least 65%, in particular between 65% and 90% or 95%.

27. The thixotropic composition according to claim 24, wherein the metal particles are present in the thixotropic composition in a concentration range of 0.005% w/w to 0.5% w/w, in particular in a concentration range of 0.05% w/w to 0.2% w/w.

28. The thixotropic composition according to claim 19, wherein the metal particles are encapsulated metal particles or metal particles having an optical effect by having a ratio of surface area to volume of at least 5.

29. The thixotropic composition according to claim 19, wherein the solvent comprises or consists of water and a diol, in particular a butanediol or a propanediol, a triol, in particular glycerol, or a polyol.

30. The thixotropic composition according to claim 29, wherein the content of water in the composition is in a range of 80% w/w to 90% w/w or at least 85% w/w, in particular at least 95% w/w, in particular 95% w/w to 98% w/w.

31. The thixotropic composition according claim 19, wherein the crystalline cellulose is partly depolymerized microcrystalline cellulose having CAS Registry Number 9004-34-6 and/or the starch glycolate is an alkaline starch glycolate, in particular sodium starch glycolate.

32. The thixotropic composition according to claim 19, wherein the alkali salt of the carboxymethyl cellulose is sodium carboxymethyl cellulose, in particular sodium carboxymethyl cellulose having CAS Registry Number 9004-32-4, and wherein the alkaline earth metal salt of the carboxymethyl cellulose is calcium carboxymethyl cellulose or magnesium carboxymethyl cellulose.

33. The thixotropic composition according to claim 19, wherein the thixotropic composition is formulated as a body care product, a sunscreen, a medicament, a spray for plants, a paint, a lacquer, an impregnant or another coating to be applied on a surface for coating that surface.

34. A spraying device containing the thixotropic composition according to claim 19, wherein content of water of the thixotropic composition in the spraying device is at least 85% w/w.

35. A method, comprising using the thixotropic composition according to claim 19 as a medical cream, a wound treatment product, a body care product, a sunscreen or a cosmetic or for the preparation thereof.

Description

[0044] In the following the invention is illustrated by means of examples for demonstrating which thixotropic compositions are able to stably suspend porous particles of silver, to be diluted with water to an appropriate silver concentration, and to produce an acceptable spray pattern under controlled conditions.

[0045] FIG. 1 shows a spray pattern of thixotropic composition 216-1D according to the invention.

[0046] FIG. 2 shows a spray pattern of thixotropic composition 216-2D not covered by the invention.

[0047] FIG. 3 shows a spray pattern of thixotropic composition 216-3D not covered by the invention.

[0048] FIG. 4 shows a spray pattern of thixotropic composition 216-4D not covered by the invention.

[0049] FIG. 5 shows a spray pattern of thixotropic composition 248-2D not covered by the invention.

[0050] FIG. 6 shows a spray pattern of thixotropic composition 248-3D not covered by the invention.

[0051] FIG. 7 shows a spray pattern of thixotropic composition 248-4D not covered by the invention.

[0052] FIG. 8 shows a spray pattern of thixotropic composition 248-5D according to the invention.

[0053] FIG. 9 shows a spray pattern of water as a control.

[0054] Concentrated thixotropic compositions comprising porous silver particles having a diameter in the range of 1 to 100 μm and an arithmetic mean inner porosity of at least 65% (MicroSilver BG, Bio-Gate AG, Neumeyerstraße 28-34, 90411 Nuremberg, Germany) were prepared as base formulations and then diluted with water to achieve a concentration of silver of 0.1% w/w in each case.

[0055] For determining stability the resulting suspensions were left to stand for 48 hours and the degree of visible settling was determined and measured.

[0056] For determining spray patterns a bottle with dip tube and spray actuator was filled with one of the diluted suspensions in each case or with water as control.

[0057] In each case this bottle was placed before a vertical panel which was prepared to reveal the spray pattern of one pump of the actuator only from a distance of 160 mm. The non-reflective black surface of the panel was coated with a hygroscopic white powder evenly with a metal straight edge. The resultant spray droplets were allowed to stand for 2 minutes and then the loose hygroscopic powder was carefully brushed away revealing the coagulated droplet pattern which was then measured and photographed form a distance of 290 mm.

[0058] The following thixotropic compositions were prepared:

[0059] Concentrated Composition:

TABLE-US-00001 216-1C Ingredients: Water 85.85% Natpure Cellgum Plus ® (Microcrystalline Cellulose, 8.50% Cellulose Gum) Submica ® E (Mica) 2.50% Zemea ® (Propanediol) 2.50% Silver (MicroSilver BG ™) 0.50% Sodium Starch Glycolate 0.15% Total: 100.00%

[0060] Diluted Composition:

TABLE-US-00002 216-1D Ingredients: Water 97.17% Natpure Cellgum Plus ® 1.70% Submica ® E 0.50% Zemea ® 0.50% MicroSilver BG ™ 0.10% Sodium Starch Glycolate 0.03% Total: 100.00% [0061] Level (mm) of water separation: from top/total height: none [0062] Product consistency: uniform [0063] Spray pattern (mm): [0064] Width: 150 mm [0065] Height: 140 mm [0066] The spray pattern obtained with composition 216-1D is shown in FIG. 1. In this and all other figures the brush that can be seen below the spray pattern is used as reference having a length of 170 mm.

[0067] Concentrated Composition:

TABLE-US-00003 216-2C Ingredients: Water 86.00% Natpure Cellgum Plus ® (Microcrystalline Cellulose, 8.50% Cellulose Gum) Submica ® E (Mica) 2.50% Zemea ® (Propanediol) 2.50% Silver (MicroSilver BG ™) 0.50% Total: 100.00%

[0068] Diluted Composition:

TABLE-US-00004 216-2D Ingredients: Water 97.20% Natpure Cellgum Plus ® 1.70% Submica ® E 0.50% Zemea ® 0.50% MicroSilver BG ™ 0.10% Total: 100.00% [0069] Level (mm) of water separation: from top/total height: 8 mm/55 mm [0070] Product consistency: thin [0071] Spray pattern (mm): [0072] Width: 60 mm [0073] Height: 50 mm

[0074] The spray pattern obtained with composition 216-2D is shown in FIG. 2.

[0075] Concentrated Composition:

TABLE-US-00005 216-3C Ingredients: Water 88.35% Natpure Cellgum Plus ® (Microcrystalline Cellulose, 8.50% Cellulose Gum) Zemea ® (Propanediol) 2.50% Silver (MicroSilver BG ™) 0.50% Sodium Starch Glycolate 0.15% Total: 100.00%

[0076] Diluted Composition:

TABLE-US-00006 216-3D Ingredients: Water 97.67% Natpure Cellgum Plus ® 1.70% Zemea ® 0.50% MicroSilver BG ™ 0.10% Sodium Starch Glycolate 0.03% Total: 100.00% [0077] Level (mm) of water separation: from top/total height: 10 mm/55 mm [0078] Product consistency: thin [0079] Spray pattern (mm): [0080] Width: 140 mm [0081] Height: 190 mm

[0082] The spray pattern obtained with composition 216-3D is shown in FIG. 3.

[0083] Concentrated Composition:

TABLE-US-00007 216-4C Ingredients: Water 88.50% Natpure Cellgum Plus ® (Microcrystalline Cellulose, 8.50% Cellulose Gum) Zemea ® (Propanediol) 2.50% Silver (MicroSilver BG ™) 0.50% Total: 100.00%

[0084] Diluted Composition:

TABLE-US-00008 216-4D Ingredients: Water 97.70% Natpure Cellgum Plus ® 1.70% Zemea ® 0.50% MicroSilver BG ™ 0.10% Total: 100.00% [0085] Level (mm) of water separation: from top/total height: 10 mm/55 mm [0086] Product consistency: thin [0087] Spray pattern (mm): [0088] Width: 130 mm [0089] Height: 150 mm

[0090] The spray pattern obtained with composition 216-4D is shown in FIG. 4.

[0091] Further Diluted Compositions:

TABLE-US-00009 248-2D Ingredients: Water 97.17% JRS Vivapur ® CS 032 XV (Microcrystalline Cellulose, 1.70% Xanthan Gum) Submica ® E 0.50% Zemea ® 0.50% MicroSilver BG ™ 0.10% Sodium Starch Glycolate 0.03% Total: 100.00% [0092] Level (mm) of water separation: from top/total height: none [0093] Product consistency: viscous [0094] Spray pattern (mm): [0095] Width: 85 mm [0096] Height: 80 mm

[0097] The spray pattern obtained with composition 248-2D is shown in FIG. 5.

TABLE-US-00010 248-3D Ingredients: Water 97.17% JRS Vitacel ® CS 200 FC (Cellulose) 1.70% Submica ® E 0.50% Zemea ® 0.50% MicroSilver BG ™ 0.10% Sodium Starch Glycolate 0.03% Total: 100.00% [0098] Level (mm) of water separation: from top/total height: 60 mm/70 mm [0099] Product consistency: thin [0100] Spray pattern (mm): [0101] Width: 235 mm [0102] Height: 190 mm [0103] The spray pattern obtained with composition 248-3D is shown in FIG. 6.

TABLE-US-00011 248-4D Ingredients: Water 97.17% Seppic ™ Solugum ™ TARA (Caesalpinia Spinosa Gum) 1.70% Submica ® E 0.50% Zemea ® 0.50% MicroSilver BG ™ 0.10% Sodium Starch Glycolate 0.03% Total: 100.00% [0104] Level (mm) of water separation: from top/total height: none [0105] Product consistency: viscous gel [0106] Spray pattern (mm): [0107] Width: 12 mm [0108] Height: 30 mm [0109] The spray pattern obtained with composition 248-4D is shown in FIG. 7.

TABLE-US-00012 248-5D Ingredients: Water 97.17% JRS Vivapur ® COS 8 (Microcrystalline Cellulose, 1.70% Cellulose gum) Submica ® E 0.50% Zemea ® 0.50% MicroSilver BG ™ 0.10% Sodium Starch Glycolate 0.03% Total: 100.00% [0110] Level (mm) of water separation: from top/total height: none [0111] Product consistency: viscous gel [0112] Spray pattern (mm): [0113] Width: 180 mm [0114] Height: 160 mm [0115] The spray pattern obtained with composition 248-5D is shown in FIG. 8.

TABLE-US-00013 Water Control Spray pattern (mm): Width: 200 mm Height: 145 mm [0116] The spray pattern obtained with the water control is shown in FIG. 9.

[0117] The spray pattern of the water control and samples 216-1D and 248-5D produced a desirable distribution of droplets from one actuation of the spray pump. It can be concluded that the stability indicated by no visible separation of water goes along with a desired relatively wide and relatively uniform distribution of the spray pattern droplets such as in samples 216-1D and 248-5D. Sample 216-2D only differs from sample 216-1D by the absence of sodium starch glycolate which absence is compensated by a slightly higher amount of water. It shows water separation and a narrow spray pattern and therewith the importance of the starch glycolate. The results also show that concentrated thixotropic compositions according to the invention comprising heavy metal particles can be diluted such that the silver particles are suspended uniformly and present in low concentrations in compositions of low viscosity that can be effectively sprayed with a wide and uniform pattern resulting in a consistent distribution of the silver particles to a surface. The results further show that omitting one of the ingredients starch glycolate, carboxymethyl cellulose and phyllosilicate results in an undesired spray pattern and/or in water separation.