Polymer composition for caps and closures

Abstract

Caps and closures comprising high density polyethylene, polyolefin elastomer and polypropylene wherein the amount of high density polyethylene is more than 50% by weight of the total amount of high density polyethylene, polyolefin elastomer and polypropylene and wherein the total amount of high density polyethylene, polyolefin elastomer and polypropylene is 100% by weight.

Claims

1. Caps and closures comprising: a high density polyethylene, a polyolefin elastomer, and a polypropylene wherein the amount of high density polyethylene is more than 50% by weight of the total amount of the high density polyethylene, the polyolefin elastomer and the polypropylene, wherein the total amount of high density polyethylene, polyolefin elastomer and polypropylene is 100% by weight, and wherein the polyolefin elastomer is an ethylene-alpha olefin copolymer derived from two monomers consisting of ethylene and an alpha olefin containing 4-10 carbon atoms.

2. The caps and closures according to claim 1, comprising the high density polyethylene in a range between 52% by weight and 100% by weight.

3. The caps and closures according to claim 1, comprising the polypropylene in a range between >0.1% by weight and 40% by weight.

4. The caps and closures according to claim 1, comprising the polyolefin elastomer in a range between >0.1% by weight and 40% by weight.

5. The caps and closures according to claim 1, comprising the high density polyethylene in a range between >50% by weight and <100% by weight and the polypropylene in a range between >0.1% by weight and 40% by weight and the polyolefin elastomer in a range between >0.1% by weight and 40% by weight.

6. The caps and closures according to claim 1, comprising the high density polyethylene in a range between >55% by weight and <100% by weight and the polypropylene in a range between 5% by weight and 35% by weight and the polyolefin elastomer in a range between 2% by weight and 20% by weight.

7. The caps and closures according to claim 1, comprising the high density polyethylene in a range between 55% by weight and <80% by weight and the polypropylene in a range between 10% by weight and 30% by weight and the polyolefin elastomer in a range between 5% by weight and 20% by weight.

8. The caps and closures according to claim 1, wherein an MFI of the high density polyethylene ranges between 0.1 and 30 g/10 min (measured according to ISO 1133 at 190 degrees Celsius and 2.16 kg) and/or a density of the high density polyethylene ranges between 950 and 958 kg/m.sup.3 (measured according to ISO 1183).

9. The caps and closures according to claim 1, wherein an MFI of the high density polyethylene ranges between 0.6 and 15 g/10 min (measured according to ISO 1133 at 190 degrees Celsius and 2.16 kg) and/or a density of the high density polyethylene ranges between >950 and <955 kg/m.sup.3 (measured according to ISO 1183).

10. The caps and closures according to claim 1, wherein an MFI of polypropylene ranges between 0.3 and 100 g/10 min (measured according to ISO1133 at 230 degrees Celsius and 2.16 kg) and/or a density of polypropylene ranges between 900 and 920 kg/m.sup.3 (measured according to ISO 1183).

11. The caps and closures according to claim 1, wherein an MFI of the polypropylene ranges between 0.3 and 10 g/10 min (MFI is determined according to ISO 1133 at 230 degrees Celsius and 2.16 kg) and/or a density of the polypropylene ranges between >902 and <906 kg/m.sup.3 (measured according to ISO 1183).

12. The caps and closures according to claim 1, wherein an MFI of the polyolefin elastomer ranges between 0.5 and 30 g/10 min (measured according to ASTM D1238 at 190 degrees Celsius and 2.16 kg) and/or a density of the polyolefin elastomer ranges between 857 and 880 kg/m.sup.3 (measured according to ASTM D1505).

13. The caps and closures according to claim 1, wherein the ethylene-alpha olefin copolymer is ethylene-octene copolymer.

14. The caps and closures according to claim 1, wherein the polypropylene is impact polypropylene.

15. The caps and closures according to claim 1, wherein an amount of high density polyethylene is higher than an amount of the polypropylene and wherein this is based on the wt % of the high density polyethylene and the wt % of the polypropylene and/or the amount of the polypropylene is higher than the amount of the polyolefin elastomer and wherein this is based on the wt % of the polypropylene and the wt % of the polyolefin elastomer.

16. The caps and closures according to claim 1, wherein an MFI of the polyolefin elastomer ranges between 0.6 and 10 g/10 min (measured according to ASTM D1238 at 190 degrees Celsius and 2.16 kg) and/or a density of the polyolefin elastomer ranges between 865 and 870 kg/m.sup.3 (measured according to ASTM D1505).

17. The caps and closures according to claim 1, wherein an MFI of the polyolefin elastomer ranges between 0.6 and 10 g/10 min (measured according to ASTM D1238 at 190 degrees Celsius and 2.16 kg) and a density of the polyolefin elastomer ranges between 865 and 870 kg/m.sup.3 (measured according to ASTM D1505).

18. The caps and closures according to claim 1, comprising the high density polyethylene in a range between 55% by weight and 70% by weight; the polypropylene in a range between >5% by weight and <35% by weight; and the polyolefin elastomer in a range between 2% by weight and 20% by weight.

19. The caps and closures according to claim 18, comprising the polypropylene in a range between >10% by weight and <30% by weight; and the polyolefin elastomer in a range between 5% by weight and 20% by weight.

20. Caps and closures comprising: a high density polyethylene in a range between >55% by weight and <80% by weight, a polyolefin elastomer in a range between 5% by weight and 20% by weight, and a polypropylene in a range between 10% by weight and 30% by weight, each based on the total amount of the high density polyethylene, the polyolefin elastomer and the polypropylene, wherein the total amount of high density polyethylene, polyolefin elastomer and polypropylene is 100% by weight, and wherein the polyolefin elastomer is ethylene-octene copolymer.

Description

EXAMPLES

Example I

(1) Test bars of a mixture comprising 66.5% by weight polyethylene (HDPE CC253 of SABIC), 5% by weight polyolefin elastomer (POE C1070D of SABIC) and 28.5% by weight impact polypropylene (PP 83MF90 of SABIC) were used to perform ESCR test according to ASTM D1693 Bent Strip ESCR test (10% Igepal CO-630, 50 C., method A) and VEM Impact resistance according to ISO 6603-2 (23 C./50% RH).

(2) Result: see Table 1.

(3) Comparative Example A shows the values for test bars comprising 100% by weight polyethylene (HDPE CC253 of SABIC).

(4) TABLE-US-00001 TABLE 1 ESCR 50% Puncture Example Blend fracture hours Energy J A HDPE CC253 9 37 I HDPE CC253/POE C1070D/PP >1000 39 83MF90

Example II

(5) Test bars of a mixture comprising 56% by weight polyethylene (CC253 of SABIC), 20% by weight polyolefin elastomer (POE C1070D of SABIC) and 24% by weight random polypropylene (PP 620P of SABIC) were used to perform ESCR test according to ASTM D1693 Bent Strip ESCR test (10% Igepal CO-630, 50 C., method A) and VEM Impact resistance according to ISO 6603-2 (23 C./50% RH).

(6) Comparative Example B shows the values for test bars comprising 100% by weight polyethylene (HDPE CC253 of SABIC),

(7) Result: see Table 2.

(8) TABLE-US-00002 TABLE 2 ESCR Example Blend 50% fracture hours Puncture Energy J B HDPE CC253 9 37 II HDPE CC253/POE >1000 37 C1070D/PP 620P

(9) The examples I and II show clearly improved ESCR performance and the same or even better impact performance in comparison to the comparative examples A and B.