Thermoplastic polyamide particles

Abstract

Thermoplastic polyamide particles comprising at least one polyamide and at least one polymeric ionic compound comprising imidazolium groups (imidazolium compound), the thermoplastic polyamide particles having an ellipsoidal or approximately ellipsoidal shape with the largest diameter of 1 to 100 mm, preferably 2 to 10 mm, more preferably 3 to 8 mm.

Claims

1. Thermoplastic polyamide particles comprising a mixture of at least one polyamide and at least one polymeric ionic compound comprising imidazolium groups (imidazolium compound), the thermoplastic polyamide particles having an ellipsoidal shape with the largest diameter of 1 to 100 mm, further comprising 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 wherein the amount of particulate inorganic fillers, based on the thermoplastic polyamide particles, is 50 to 80 wt %, wherein an ellipsoidal shape is characterized by the diameter of the ellipsoid at any, arbitrarily selected position of the ellipsoid deviating by not more than 20% from the corresponding diameter of an ideal ellipsoid, wherein the polymeric ionic compound contains at least one end group capable of forming a covalent bond with the polyamide and wherein from mixing and heating of polymeric imidazolium compound and polyamide, a covalent bond or linkage between polymeric imidazolium compound and polyamide main chain is formed.

2. The thermoplastic polyamide particles according to claim 1, wherein the polymeric ionic compound comprising imidazolium groups (imidazolium compound) is obtained by reacting a) at least one α-dicarbonyl compound, b) at least one aldehyde, c) at least one amino compound having at least two primary amino groups, d) optionally an amino compound having only one primary amino group and e) at least one protic acid, and optionally subjecting the reaction product to an anion exchange, wherein the components a) and b) the aldehyde carbonyl groups may also be present as hemiacetal or acetal and the ketone carbonyl groups may also be present as hemiketal or ketal.

3. The thermoplastic polyamide particles according to claim 2, wherein the main chain of the at least one imidazolium compound apart from the nitrogen atoms of the imidazolium groups does not contain any quaternary nitrogen atoms that bear 4 residues that are different from hydrogen.

4. The thermoplastic polyamide particles according to claim 2, wherein component c) is selected from
amines of the formula 1 H.sub.2N-A-NH.sub.2  (1) wherein A is a divalent aliphatic, alicyclic, aliphatic-alicyclic, aromatic or araliphatic radical, where the aliphatic moieties in the aforementioned aliphatic, aliphatic-alicyclic or araliphatic radicals may be interrupted by one or more nonadjacent groups which are selected from —O—, —S— and —N(R.sup.b)—, where R.sup.b is selected from hydrogen, C.sub.1-C.sub.20-alkyl and a group CH.sub.2CH.sub.2—O.sub.y—R.sup.c, wherein y is 1, 2, 3, 4, 5 or 6 and R.sup.c is hydrogen or C.sub.1-C.sub.4-alkyl; where alicyclic or aromatic moieties in the aforementioned alicyclic, aliphatic-alicyclic, aromatic or araliphatic radicals may be substituted by 1, 2, 3 or 4 radicals selected from C.sub.1-C.sub.20-alkyl, C.sub.1-C.sub.20-alkoxy, a radical of the formula —O—CH.sub.2CH.sub.2O].sub.z—R.sup.d, where R.sup.d is hydrogen or C.sub.1-C.sub.4-alkyl and z is 1, 2, 3, 4, 5 or 6; carboxyl and carboxylate, and where the aliphatic moieties in the aforementioned aliphatic, aliphatic-alicyclic or araliphatic radicals may be substituted by 1, 2, 3 or 4 radicals selected from C.sub.1-C.sub.20-alkoxy, a radical of the formula —O—CH.sub.2CH.sub.2O].sub.z—R.sup.d, where R.sup.d is hydrogen or C.sub.1-C.sub.4-alkyl and z is 1, 2, 3, 4, 5 or 6, carboxyl and carboxylate; with the proviso that the aromatic or araliphatic radicals preferably do not contain 1,4-bound phenylene rings; amines of the formula 2 ##STR00017## in which Y is CR.sup.C, N, C.sub.2-C.sub.6-alkyl or C.sub.3-C.sub.6-cycloalkyl; E.sub.1, E.sub.2 and E.sub.3, independently of each other, are a single bond, C.sub.1-C.sub.10-alkylene, —NR.sup.D—C.sub.2-C.sub.10-alkylene or —O—C.sub.1-C.sub.10-alkylene, with the proviso that E.sub.1, E.sub.2 and E.sub.3 are not a single bond and are not —NR.sup.D—C.sub.2-C.sub.10-alkylene when Y is N; R.sup.C is H, C.sub.1-C.sub.4-alkyl, C.sub.2-C.sub.4-hydroxyalkyl or C.sub.1-C.sub.4-alkoxy; and R.sup.B and R.sup.D, independently of each other, are H, C.sub.1-C.sub.4-alkyl, C.sub.2-C.sub.4-hydroxyalkyl or C.sub.1-C.sub.4-alkoxy; and mixtures thereof and/or wherein component c) is selected from nitrogen-comprising polymers.

5. The thermoplastic polyamide particles according to claim 4, wherein the divalent aliphatic radicals A are selected from linear and branched C.sub.1-C.sub.30-alkylene which may be interrupted by one or more nonadjacent groups which are selected from —O—, —S— and —N(R.sup.b)—, where R.sup.b is selected from hydrogen, C.sub.1-C.sub.20-alkyl and a group CH.sub.2CH.sub.2—O.sub.y—R.sup.c, wherein y is 1, 2, 3, 4, 5 or 6 and R.sup.c is hydrogen or C.sub.1-C.sub.4-alkyl; and/or may be substituted by 1, 2, 3 or 4 radicals selected from C.sub.1-C.sub.20-alkoxy, a radical of the formula —O—CH.sub.2CH.sub.2O].sub.z—R.sup.d, where R.sup.d is hydrogen or C.sub.1-C.sub.4-alkyl and z is 1, 2, 3, 4, 5 or 6, carboxyl and carboxylate; the divalent alicyclic radicals A are selected from C.sub.5-C.sub.8-cycloalkylene which may carry 1, 2, 3 or 4 C.sub.1-C.sub.4-alkyl radicals; the divalent aliphatic-alicyclic radicals A are selected from C.sub.1-C.sub.4-alkylene-C.sub.5-C.sub.8-cycloalkylene, C.sub.5-C.sub.8-cycloalkylene-C.sub.1-C.sub.4-alkylene-C.sub.5-C.sub.8-cycloalkylene and C.sub.1-C.sub.4-alkylene-C.sub.5-C.sub.8-cycloalkylene-C.sub.1-C.sub.4-alkylene, with the cycloalkylene radicals possibly carrying 1, 2, 3 or 4 C.sub.1-C.sub.4-alkyl radicals; the divalent aromatic radicals A are selected from 1,2-phenylene, 1,3-phenylene, naphthylene and biphenylene, with the phenylene radicals possibly carrying 1, 2, 3 or 4 radicals selected from C.sub.1-C.sub.20-alkyl, C.sub.1-C.sub.20-alkoxy and a radical of the formula —O—CH.sub.2CH.sub.2O].sub.z—R.sup.d, where R.sup.d is hydrogen or C.sub.1-C.sub.4-alkyl and z is 1, 2, 3, 4, 5 or 6; and the divalent araliphatic radicals A are selected from phenylene-C.sub.1-C.sub.4-alkylene, phenylene-C.sub.1-C.sub.4-alkylene-phenylene and C.sub.1-C.sub.4-alkylene-phenylene-C.sub.1-C.sub.4-alkylene, with the phenylene radicals possibly carrying 1, 2, 3 or 4 radicals selected from C.sub.1-C.sub.20-alkyl, C.sub.1-C.sub.20-alkoxy and a radical of the formula —O—CH.sub.2CH.sub.2O].sub.z—R.sup.d, where R.sup.d is hydrogen or C.sub.1-C.sub.4-alkyl and z is 1, 2, 3, 4, 5 or 6.

6. The thermoplastic polyamide particles according to claim 4, wherein component c) is selected from compounds of the formula H.sub.2N—(CH.sub.2).sub.m—NH.sub.2, wherein m is an integer of 3 to 20, where a CH.sub.2 group may be substituted by a carboxyl or carboxylate group; compounds of the formula NH.sub.2[B—X].sub.k—B—NH.sub.2; in which X is O, each B independently is C.sub.2-C.sub.6-alkylene; and k is an integer from 1 to 100; bis(4-aminocyclohexyl)methane, bis(3-aminocyclohexyl)methane, isophoronediamine, 1,1-bis(aminomethyl)cyclohexane, 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 2-aminopropylcyclohexylamine, 3(4)-aminomethyl-1-methylcyclohexylamine; 3-aminomethyl-benzylamine; amines of the formula 2, wherein Y is CR.sup.C, where R.sup.C is H or C.sub.1-C.sub.4-alkyl, and E.sub.1, E.sub.2 and E.sub.3, independently of each other, are —O—C.sub.1-C.sub.6-alkylene; and mixtures thereof, or wherein component c) is a mixture of amino compounds, comprising at least one amine with two primary amino groups and at least one amine with more than two, in particular three, primary amino groups.

7. The thermoplastic polyamide particles according to claim 1, wherein the anions of the at least one protic acid e) and/or the anions of the imidazolium compound are selected from: the group of chloride, bromide and iodide, the group of carboxylates and polybasic carboxylic acids, the group of sulfates, sulfites and sulfonates, and the group of phosphates.

8. The thermoplastic polyamide particles according to claim 1, wherein the end group of the polymeric ionic compound is an amino group.

9. The thermoplastic polyamide particles according to claim 1, wherein the thermoplastic polyamide particles have a density of at least 1.9 g/cm.sup.3.

10. The thermoplastic polyamide particles according to claim 9, wherein the particulate inorganic filler is selected from metals, metal oxides, metal salts, and mixtures thereof.

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

12. The method according to claim 11, wherein the shaping is a pelletizing.

13. The method according to claim 11, wherein the mixing is extruding.

14. The method according to claim 11, wherein the mixing is at a temperature in the range of 240 to 350° C.

15. The method according to claim 12, wherein the pelletizing is a water pelletizing.

Description

EXAMPLES

1 Raw Materials

(1) Ultramid B27 is a polyamide (PA6) from BASF SE. It has a viscosity number of 150 ml/g. Polyimidazolium salts are: Polybutyl imidazolium TFSI Polybutyl imidazolium hydrogensulfate Polybutyl imidazolium acetate Polybutyl imidazolium tosylate Polyhexyl imidazolium TFSI Polyhexyl imidazolium hydrogensulfate Polyhexyl imidazolium acetate Polyhexyl imidazolium tosylate Polydodecyl imidazolium tosylate Polydodecyl imidazolium TFSI Polydodecyl imidazolium hydrogensulfate Polydodecyl imidazolium acetate Polyxylylene imidazolium tosylate Polyxylylene imidazolium TFSI Polyxylylene imidazolium hydrogensulfate Polyxylylene imidazolium acetate TFSI is bis(trifluormethanesulfonyl)imide Preferred are Polybutyl imidazolium TFSI Polybutyl imidazolium hydrogensulfate Polydodecyl imidazolium tosylate Polydodecyl imidazolium TFSI Polydodecyl imidazolium hydrogensulfate Polyxylylene imidazolium TFSI Imid. is polybutyl imidazolium TFSI TFSI is bis(trifluormethanesulfonyl)imide

(2) Viscosity numbers were determined in 96% sulfuric acid according to DIN ISO 307.

(3) The polyimidazolium salts were prepared in an analogous manner to example 1 of WO 2010/072571 or the table on pages 162-164 of WO 2012/127009 employing the appropriate (alkylene)diamine and counter ion. They contain on average more than 10 imidazolium groups per molecule.

2 Antimicrobial Activity

2.1 Samples

(4) Ultramid B27 was extruded in a DSM Xplore 15 Micro Compounder at a melt temperature of 260° C., and 1 wt. % or 3 wt. % of antimicrobial additive were admixed in the extruder. It is assumed that covalent bonding of the imidazolium compound to the polyamide main chain took place at these conditions. Subsequently, plaques of size 3×3 cm were injection molded using a DSM Research 10 cm.sup.3 laboratory injection molding machine.

(5) Sample Appearance:

(6) light-beige-beige, sample size: 3×3 cm

2.2 Test Method

(7) ISO 22196-2011-08-01 second edition

2.3 Test Microorganism

(8) Escherichia coli DSM 1576˜ATCC 8739 Staphylococcus aureus DSM 346˜ATCC 6538P Aspergillus niger DSM 1957

2.4 Test Procedure

(9) In accordance with ISO 22196:2011 microorganisms were inoculated on the sample surface, covered with a regular film, and incubated at 37° C. for 24 hours for bacteria. Aspergillus niger (since it is a mold not part of the test method) was incubated at 30° C. for 48 hours. Due to deviant sample size test conditions have been adjusted with regard to cover film size and inoculum volume. Since number of samples was limited, test was done as duplicates instead of triplicates. Afterwards, the number of viable cells of microorganisms was counted. Value of antimicrobial activity of each sample was calculated according to the following formula:
R=Log(B/C) R: Value of antimicrobial activity expressed as log-reduction B: Average of the number of microorganisms on the control samples, i.e. samples without antimicrobial additive after incubation for 24 hours. C: Number of microorganisms on the antimicrobial treated samples after incubation for 24 hours.

(10) Criteria for Antimicrobial Efficacy:

(11) According to test method JIS Z 2801 (a method very much comparable to ISO 22196) the value of antimicrobial activity R shall not be under 2.0 to judge a product as antimicrobially active. ISO 22196 does not include any minimum requirements for antimicrobial activity.

2.5 Results

(12) TABLE-US-00001 TABLE 1 testing against bacteria (1% active concentration) E. coli S. aureus E. coli S. aureus Active DSM 1576 DSM 346 DSM 1576 DSM 346 Test Formulation substance Concentration Aspect [cfu/cm.sup.2] [cfu/cm.sup.2] [average] [average] 1 Blank Ultramid light beige 9.0E+04 2.1E+04 B27 0 h AE 9.3E+04 1.8E+04 2 Blank Ultramid 9.3E+05 9.0E+03 1.2E+06 4.8E+03 B27 24 h 1.4E+06 6.5E+02 [log- [log- reduction] reduction] 3 Polybutyl Polyimidazolium 1% light beige, <1 <1 >6.1 >3.7 imidazolium salt AE <1 <1 >6.1 >3.7 TFSI 4 Polybutyl Polyimidazolium 1% beige <1 <1 >6.1 >3.7 imidazolium salt <1 <1 >6.1 >3.7 hydrogensulfate 5 Polydodecyl Polyimidazolium 1% light beige <1 <1 >6.1 >3.7 imidazolium salt <1 <1 >6.1 >3.7 tosylate 6 Polydodecyl Polyimidazolium 1% beige 1.3E+04 <1 2.0 >3.7 imidazolium salt 3.5E+04 <1 1.6 >3.7 TFSI 7 Polydodecyl Polyimidazolium 1% light beige <1 <1 >6.1 >3.7 imidazolium salt <1 2.5E+02 >6.1 1.3 hydrogensulfate 8 Polyxylylene Polyimidazolium 1% beige 23 <1 4.7 >3.7 imidazolium salt <1 <1 >6.1 >3.7 TFSI

(13) TABLE-US-00002 TABLE 2 testing against bacteria (3% active concentration) E. coli S. aureus E. coli S. aureus Active DSM 1576 DSM 346 DSM 1576 DSM 346 Test Formulation substance Concentration Aspect [cfu/cm.sup.2] [cfu/cm.sup.2] [average] [average] 1 Blank Ultramid light beige 2.8E+04 1.8E+04 B27 0 h AE 2 Blank Ultramid 3.1E+05 1.9E+04 3.1E+05 1.9E+04 B27 24 h [log- [log- reduction] reduction] 3 Polydodecyl Polyimidazolium 3% beige <1 not tested >5.5 not tested imidazolium salt <1 >5.5 TFSI 4 Polydodecyl Polyimidazolium 3% light beige not tested <1 >4.3 imidazolium salt <1 >4.3 hydrogensulfate

(14) TABLE-US-00003 TABLE 3 testing against fungus (1% active concentration) A. niger A. niger Active DSM 1957 DSM 1957 Test Formulation substance Concentration Aspect [cfu/cm.sup.2] [average] 1 Blank Ultramid light beige 1.1E+04 1.2E+04 B27 0 h AE 1.3E+04 2 Blank Ultramid 1.0E+04 7.5E+03 B27 24 h 5.0E+03 [log- reduction] 3 Polybutyl Polyimidazolium 1% light beige, 1.3E025 1.8 imidazolium TFSI salt AE 3.2 4 Polybutyl Polyimidazolium 1% beige 2.8E+03 <1 imidazolium salt 5.8E+03 <1 hydrogensulfate 5 Polydodecyl Polyimidazolium 1% light beige 1.0E+04 <1 imidazolium salt 8.8E+03 <1 tosylate 6 Polydodecyl Polyimidazolium 1% beige 7.3E+03 <1 imidazolium salt 8.0E+03 <1 TFSI 7 Polydodecyl Polyimidazolium 1% light beige 6.0E+03 <1 imidazolium salt 8.0E+03 <1 hydrogensulfate 8 Polyxylylene Polyimidazolium 1% beige 4.8E+03 <1 imidazolium salt 8.8E+03 <1 TFSI

(15) TABLE-US-00004 TABLE 4 testing against fungus (3% active concentration) A. niger A. niger Active DSM 1957 DSM 1957 Test Formulation substance Concentration Aspect [cfu/cm.sup.2] [average] 1 Blank Ultramid light beige 9.9E+03 1.5E+04 B27 0 h AE 2.0E+04 2 Blank Ultramid 1.8E+04 1.2E+04 B27 24 h 6.0E+03 [log- reduction] 3 Polybutyl Polyimidazolium 3% light beige, <1 >4.1 imidazolium TFSI salt AE <1 >4.1 4 Polybutyl Polyimidazolium 3% beige 3.8E+03 <1 imidazolium salt 7.0E+03 <1 hydrogensulfate 5 Polydodecyl Polyimidazolium 3% light beige 1.3E+04 <1 imidazolium salt 5.5E+03 <1 tosylate 6 Polydodecyl Polyimidazolium 3% beige 3.0E+03 <1 imidazolium salt 9.0E+03 <1 TFSI 7 Polydodecyl Polyimidazolium 3% light beige 6.5E+03 <1 imidazolium salt 9.0E+03 <1 hydrogensulfate 8 Polyxylylene Polyimidazolium 3% beige 4.8E+03 <1 imidazolium salt 2.0E+03 <1 TFSI

2.6 Conclusion

(16) Most of the actives incorporated into the polyamide exhibited already at 1% an excellent antibacterial performance against both test bacteria. Those who didn't showed excellent performance at 3% loading.

(17) Antifungal activity was observed for the polyamide samples containing polybutyl imidazolium TFSI or polyhexyl imidazolium acetate.

(18) The same effects are to be expected when the polyamide additionally contains a particulate inorganic filler as described above.

(19) 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.

(20) 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.

(21) 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.