Thermoplastic Polyamide Particles

Abstract

Thermoplastic polyamide particles comprise at least one polyamide and at least one particulate inorganic filler having a density of at least 2.5 g/cm.sup.3, the thermoplastic polyamide particles having a density of at least 1.65 g/cm.sup.3, preferably at least 1.9 g/cm3, and an ellipsoidal or approximately ellipsoidal shape with a largest diameter of 1 to 100 mm, preferably 2 to 10 mm, more preferably 3 to 8 mm, or they comprise at least one polyamide and at least one inorganic filler, which is a particulate BaSO.sub.4 filler, having a D.sub.50-value of the particle size distribution of at least 10 μm and/or a D.sub.90-value of at least 15 μm, preferably at least 40 μm.

Claims

1. Thermoplastic polyamide particles comprising at least one polyamide and at least one particulate inorganic filler having a density of at least 2.5 g/cm.sup.3, the thermoplastic polyamide particles having a density of at least 1.65 g/cm.sup.3, and an ellipsoidal or approximately ellipsoidal shape with a largest diameter of 1 to 100 mm, preferably 2 to 10 mm.

2. The thermoplastic polyamide particles according to claim 1, wherein the inorganic filler is selected from metals, metal oxides, metal salts, and mixtures thereof.

3. The thermoplastic polyamide particles according to claim 1, wherein the amount of particulate inorganic fillers, based on the thermoplastic polyamide particles, is 41 to 80 wt %.

4. The thermoplastic polyamide particles according to claim 1, wherein the inorganic filler is a particulate filler, having a D.sub.50-value of the particle size distribution of at least 10 μm.

5. The thermoplastic polyamide particles according to claim 1, wherein the inorganic filler is a particulate filler, having a D.sub.50-value of the particle size distribution of at least 10 μm and a D.sub.90-value of at least 40 μm.

6. The thermoplastic polyamide particles according to claim 4, wherein the D.sub.50-value of particle size distribution of the inorganic filler in the range of from 10 to 25 μm, and/or a D.sub.90 value which is in the range of 40 to 120 μm.

7. Thermoplastic polyamide particles comprising at least one polyamide and at least one inorganic filler, which is a particulate BaSO.sub.4 filler, having a D.sub.50-value of the particle size distribution of at least 10 μm and/or a D.sub.90-value of at least 15 μm.

8. The thermoplastic polyamide particles according to claim 7, wherein the D.sub.50-value of the BaSO.sub.4 is in the range of from 10 to 25 μm and/or the D.sub.90 value is in the range of 40 to 120 μm.

9. The thermoplastic polyamide particles according to claim 1, wherein the aspect ratio of the particles is smaller than 1.2.

10. The thermoplastic polyamide particles according to claim 1, wherein the at least one polyamide is an aliphatic polyamide.

11. The thermoplastic polyamide particles according to claim 10, wherein the at least one polyamide is nylon-6, nylon-6,6, or a blend or copolymer of these polyamides.

12. A method for producing thermoplastic polyamide particles according to claim 1 by extruding the ingredients and subsequently shaping.

13. The method according to claim 12, wherein the shaping is a pelletizing.

14. A laundering process comparing the use of thermoplastic polyamide particles according to claim 1.

15. The method of claim 14 wherein unclean textiles are cleaned by agitating the textiles in the presence of a cleaning composition comprising the polyamide particles of claim 1 and a liquid medium.

16. The method according to claim 14, wherein unclean textiles are cleaned by treatment with thermoplastic polyamide particles according to claim 1 and washing water, the treatment being carried out in an apparatus comprising a drum with perforated side walls and a capacity of 5 to 50 l per kg of textiles to be cleaned, the thermoplastic polyamide particles being used in a weight ratio to the textiles in the range of 0.1:1-10:1, and the drum with the perforated side walls being rotated at a speed which leads to the development of g-forces in the range from 0.05 to 900 g.

Description

EXAMPLES

1 Raw Materials

[0156] Ultramid® B40 is a polyamide (PA6) from BASF SE. It has a viscosity number of 250 ml/g. Ultramid C33 is a polyamide (PA6.66) from BASF SE. It has a viscosity number of 195 ml/g. [0157] Ultramid B27 is a polyamide (PA6) from BASF SE. It has a viscosity number of 150 ml/g. [0158] Blanc Fixe® N is a type of barium sulfate from Sachtleben. In the examples recited, barium sulfate is used to increase the density. The gross density of the Blanc Fixe® N used is 4.5 g/ml; the D.sub.50 value of the particle size is 5.8 μm. [0159] Portaryte® D150 is a type of barium sulfate from Sibelco. In the examples recited, barium sulfate is used to increase the density. The D.sub.50 value of the particle size is 13.3 μm. [0160] Portaryte® B40/10 is a type of barium sulfate from Sibelco. In the examples recited, barium sulfate is used to increase the density. The D.sub.50 value of the particle size is 15.7 μm.

[0161] Viscosity numbers were determined in 96% sulfuric acid according to DIN ISO 307.

[0162] Particle size distributions of the BaSO.sub.4 fillers have been analyzed by laser diffraction method (Fraunhofer diffraction) using a Mastersizer 3000 of Malvern. The samples were dispersed in destilled water treated with an ultrasound source for 30 seconds.

TABLE-US-00002 TABLE 1 D.sub.10 [μm] D.sub.50 [μm] D.sub.90 [μm] D.sub.97 [μm] Span Blanc Fixe N 1.7 5.8 13.2 19.0 1.98 Portaryte B40/10 8.8 15.8 26.5 32.2 1.12 Portaryte D150 2.0 13.3 65.9 149.0 4.80

[0163] Compounding:

[0164] The Polyamide was extruded with the additives listed below in a twin-screw extruder at a melt temperature of 270-340° C. The additives were metered in via a side feed with a gravimetric metering balance. The twin-screw extruder was followed by underwater pelletizing, which was carried out as described in WO 2004/080679 in Example 1. The particle shape and characteristics can be found in table 2.

TABLE-US-00003 TABLE 2 Ref. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ultramid 100 B40 [wt. %] Ultramid 40 35 30 40 35 30 30 B27 [wt. %] Ultramid 50 25 C33 [wt. %] Blanc 50 60 65 70 Fixe N [wt. %] Portaryte 60 65 70 75 D150 [wt. %] Portaryte 70 B40/10 Qualitative Excellent Excellent OK OK OK Excellent Excellent Excellent Excellent OK Shape Minimum 3.427 3.509 3.619 3.111 3.189 4.004 3.957 3.910 4.009 3.12 Diameter [mm] Maximum 4.009 4.008 4.622 4.623 4.333 4.187 4.29 4.300 4.647 3.94 Diameter [mm] Aspect 1.172 1.14 1.280 1.505 1.372 1.048 1.086 1.10 1.162 1.26 ratio Density 1.13 1.78 2.01 2.15 2.31 1.98 2.10 2.15 2.39 2.11 [g/ml]

[0165] Measurements:

[0166] The assessment of the overall polymer particle shape is done visually:

[0167] Excellent: Overall shape is elliptical, aspect ratio<1.2

[0168] OK: Overall shape close to cylindrical, aspect ratio>1.2

[0169] The dimensions of the polymer particles were determined using a vernier caliper. The measurements were repeated on 30 particles in order to get statistical information on the distribution of the sizes and the aspect ratio.

[0170] The density of the particles was evaluated using a pyknometer according to DIN ISO 1183-1:2012.

[0171] The increase in density through incorporation of the heavy filler BaSO.sub.4 is clear from reference 1 and examples 1 to 5.

[0172] According to the data given in table 2 it can be concluded that fine particular fillers with a narrow particle size distribution as they are used regularly in paints like Blanc fixe N, having a D50 of 5.8 μm and a narrow particle size distribution lead to less favorable processing conditions especially when dosed in high loadings (higher than 50 wt %). This is especially noticeable in strong process fluctuations like changes in melt pressure. These formulations are therefore not appropriate to get round/elliptical particles especially at loading levels >50%. As it can be seen from the table with loadings higher than 50 wt % the particle form changes from round to cylindrical being not applicable for washing processes anymore since the separation of the particles and the laundering goods through the perforated drum is hindered. This can be observed especially for aspect ratios of >1.2. These difficulties cannot be overcome through changes in processing parameters.

[0173] Similar processing characteristics can be observed using Portaryte B40/10 at high loading levels.

[0174] In contrast to these results Portaryte D150, leads to completely different processing characteristics even at very high loading levels (>60 wt %), being easily dosable and enabling a processing with limited fluctuations in melt pressure. This enables very high filler loading while retaining a very well defined and constant elliptical granulate shape with a very narrow particle size distribution and a low and constant aspect ratio.

[0175] The application of particles with increased densities leads to an improved separation of the beads after the washing cycles from the clothes.

2 Cleaning

2.1 Cleaning Examples and Methods

[0176] The following cleaning particles as prepared in part 1 above were selected for cleaning experiments: Comparative Example Ref 1 and Example 8.

[0177] 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.

[0178] After each cleaning cycle the wash load was rinsed and the washing apparatus performed a separation cycle for a period of 30 minutes.

[0179] 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

[0180]

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 Ref. 1 Example 8 15.79 17.93 17.05 10.72 19.66 13.03

[0181] As can be seen the cleaning results were superior when the method of the present invention was performed using the cleaning particles of Example 8 as opposed to Comparative Example Ref. 1.

3 Separation

3.1 Separation Examples and Method

[0182] The following cleaning particles as prepared in part 1 above were selected for separation experiments: Comparative Example Ref. 1, Example Ref. 2 and Example 8.

[0183] 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.

[0184] In every case the wash load was rinsed and the separation cycle was run for 30 minutes.

[0185] 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 were calculated for all of the 5 washing experiments using each type of cleaning particle. The results are as described in Table 4.

TABLE-US-00005 TABLE 4 Separation results Average number of particles Cleaning particles unseparated Comparative Example Ref. 1 604.0 Example 2 442.6 Example 8 249.2

[0186] As can be seen the separation results for the cleaning particles in Examples 2 and 8 using the method of the present invention were far superior to those obtained for the cleaning particles in Comparative Example Ref. 1. This is highly desirable as the end user has far fewer unseparated cleaning particles to remove from the final wash.

[0187] 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.

[0188] 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.

[0189] 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.