A POLYETHYLENE PIPE

Abstract

A polyethylene pipe comprising components A) and B), wherein component A) is a hindered amine light stabilizer containing a triazine residue, component B) is a natural or synthetic hydrotalcite and the weight ratio of component A) to component B) is 1:10 to 10:1.

Claims

1. A polyethylene pipe comprising components A) and B), wherein component A) is a hindered amine light stabilizer comprising a triazine residue, component B) is a natural or synthetic hydrotalcite, and a weight ratio of component A) to component B) is 1:10 to 10:1.

2. The polyethylene pipe according to claim 1 wherein component A) is at least one compound of the formula (A-I), (A-II) or (A-III): ##STR00028## wherein A.sub.11 is C.sub.2-C.sub.18alkylene, C.sub.5-C.sub.7cycloalkylene or C.sub.1-C.sub.4alkylenedi(C.sub.5-C.sub.7cycloalkylene), the radicals A.sub.12 independently of one another are hydrogen, C.sub.1-C.sub.12alkyl, C.sub.5-C.sub.12cycloalkyl, A.sub.13 and A.sub.14 independently of one another are hydrogen, C.sub.1-C.sub.12alkyl, C.sub.5-C.sub.12cycloalkyl or a group of the formula (a-1), ##STR00029## or the radicals A.sub.13 and A.sub.14, together with the nitrogen atom to which they are bonded, form a 5- to 10-membered heterocyclic ring and a.sub.1 is a number from 1 to 20, and the repeating units are identical or different; ##STR00030## wherein A.sub.21 and A.sub.25 independently of one another are hydrogen, C.sub.1-C.sub.12alkyl, C.sub.5-C.sub.12cycloalkyl or a group of the formula (a-1), A.sub.22, A.sub.23 and A.sub.24 independently of one another are alkylene, and X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5, X.sub.6, X.sub.7 and X.sub.8 independently of one another are a group of the fornlula (a-2), ##STR00031## in which A.sub.26 is hydrogen, C.sub.1-C.sub.12alkyl, C.sub.5-C.sub.12cycloalkyl or a group of the formula (a-1) as defined above, and A.sub.27 has one of the meanings of A.sub.12; ##STR00032## wherein R.sub.1 and R.sub.2 independently of one another are hydrogen, C.sub.1-C.sub.22alkyl, O., OH, CH.sub.2CN, C.sub.1-C.sub.18alkoxy, C.sub.2-C.sub.18alkoxy substituted by OH; C.sub.5-C.sub.12cycloalkoxy, C.sub.3-C.sub.6alkenyl, C.sub.3-C.sub.6akenyloxy, C.sub.7-C.sub.9phenyialkyl unsubstituted or substituted on the phenyl by 1, 2 or 3 C.sub.1-C.sub.4alkyl; or C.sub.1-C.sub.8acyl; and R.sub.3 and R.sub.4 independently of one another are C.sub.1-C.sub.22alkyl or a group of the formula (a-3) ##STR00033## wherein R.sub.0 has one of the meanings of R.sub.1 and R.sub.2.

3. The polyethylene pipe according to claim 2, wherein A.sub.11 is C.sub.2-C.sub.10alkylene, the radicals A.sub.12 independently of one another are hydrogen, C.sub.1-C.sub.4alkyl or cyclohexyl, A.sub.13 and A.sub.14 independently of one another are hydrogen, C.sub.1-C.sub.4alkyl, cyclohexyl or a group of the formula (a-1), ##STR00034## or the radicals A.sub.13 and A.sub.14, together with the nitrogen atom to thich they are bonded, form a motpholino group and a.sub.1 is a number from 1 to 10, and the repeating units are identical or different; A.sub.21 and A.sub.25 independently of one another are hydrogen, C.sub.1-C.sub.4alkyl or cyclohexyl, A.sub.22, A.sub.23 and A.sub.24 independently of one another are C.sub.2-C.sub.l0alkylene, and X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5, X.sub.6, X.sub.7 and X.sub.8 independently of one another are a group of the formula (a-2), ##STR00035## in which A.sub.26 is hydrogen, C.sub.1-C.sub.4alkyl, cyclohexyl or a group of the formula (a-1) as defined above, and A.sub.27 has one of the meanings of A.sub.l2; R.sub.1 and R.sub.2 independently of one another are hydrogen, C.sub.1-C.sub.4alkyl or cyclohexyl; and R.sub.3 and R.sub.4 independently of one another are C.sub.1-C.sub.4alkyl or a group of the formula (a-3) ##STR00036## wherein R.sub.0 has one of the meanings of R.sub.1 and R.sub.2.

4. The polyethylene pipe according to claim 1, wherein component A) is a compound of the formula (A-I-1), (A-I-2), (A-II-1) or (A-III-1), ##STR00037## with a.sub.1 being 2 to 10, ##STR00038## with a.sub.1 being 2 to 10, ##STR00039## wherein X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5, X.sub.6, X.sub.7 and X.sub.8 are the group ##STR00040##

5. The polyethylene pipe according to claim 1, wherein component B) is at least one selected from the group consisting of magnesium aluminum hydroxide carbonate hydrate and zinc aluminum hydroxide carbonate hydrate.

6. The polyethylene pipe according claim 5, further comprising a component C) which is a phenolic antioxidant.

7. The polyethylene pipe according to claim 1, further comprising a components)) which is at least one compound selected from the group consisting of phosphites, phosphonites, hydroxylamines, tocopherols and tocopherol acetates.

8. The polyethylene pipe according to claim 6, wherein the phenolic antioxidant is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene; ethylene bis[3,3-his(3-tert-butyl4-hydroxyphenyl)butyrate] or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate.

9. The polyethylene pipe according to claim 7, wherein component D) is a phosphite.

10. The polyethylene pipe according to claim 1, further comprising a pigment.

11. The polyethylenepipe according to claim 1, wherein the polyethylene is selected from the group consisting of high densit' polyethylene (HD-PE), medium density polyethylene (MD-PE), low density polyethylene (LD-PE), linear low density polyethylene (LLD-PE), metallocene polyethylene, crosslinked polyethylene (PE-X), recycled polyethylene, bi-modal polyethylene and mixtures of polyethylenes.

12. The polyethylene pipe according to claim 1, further comprising components C) and D), wherein component (A) is ##STR00041## with a.sub.1 being 2 to 10, component (B) is a natural or synthetic hydrotalcite, component (C) is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, and component (D) is tris[2,4-di-tert-butylphenyl]phosphite.

13. The polyethylene pipe according to claim 1, which is in contact with chlorinated or non-chlorinated water.

14. (canceled)

15. A method for stabilizing a polyethylene pipe, the method comprising incorporating polyethylene components A) and B) in a weight ratio of 1:10 to 10:1 into the pipe, wherein component A) is a hindered amine light stabilizer comprising a triazine residue, and component B) is a natural or synthetic hydrotalcite.

Description

EXAMPLES

[0151] Preparation of the test specimens: A mixture of a non-stabilised high density polyethylene (HD-PE; Hostalen CRP-100; natural classified under PE 100 of LyondellBasell; Melt Flow Rate: 190 C./5.0 Kg: 0.23 g/10 min (ISO 1133); Density: 0.95g/cm3 (ISO 1183)) and the additives listed in Table 1 is mixed with a Mixaco Lab CM12 high speed mixer device.

[0152] The obtained full formulation is then compounded on a Collin 25X42D extruder at 240 C. and then injection molded on an Engel HL65 injection molding machine at 230 C.

[0153] The injection molded plaques 40 mm60 mm2 mm are exposed to chlorinated water under the following parameters: 40 C., pH 7, 2 mg/L NaClO and 50 L/hours. The parameters measured are OIT Values using a DSC Q2000 von TA Instrument (Waters) at 200 C. under O.sub.2 after 0, 3 and 5 months exposition. The depletion results are listed in Table 2.

TABLE-US-00001 TABLE 1 Additive Formulation No. 0.3% of Irganox1330 + 0.1% of Irgafos168 + 0 0.2% of Hycite713 0.3% of Irganox1330 + 0.1% of Irgafos168 1 plus 0.2% of Chimassorb2020 + 0.2% of Hycite713 0.3% of Irganox1330 + 0.1% of SumilizerGP 2 plus 0.2% of Chimassorb2020 + 0.2% of Hycite713 0.3% of Irganox1330 + 0.1% of Compound (D-1) 3 plus 0.2% of Chimassorb2020 + 0.2% of Hycite713 0.3% of Irganox1330 + 0.1% of a mixture of 4 Compound (D-1) and Irgafos168 in a weight ratio of 10/1 plus 0.2% of Chimassorb2020 + 0.2% of Hycite713

TABLE-US-00002 TABLE 2 Formulation OIT at OIT after OIT after No. time zero 3 months 5 months 0 50 50 50 1 240 200 190 2 220 180 160 3 280 200 200 4 230 190 180

[0154] High OIT-values are desired.