Composition for blow molding

Patent metadata

Field	Value
Publication number	US-9896573-B2
Application number	US-201113639114-A
Country	US
Kind code	B2
Filing date	Apr 11, 2011
Priority date	Apr 12, 2010
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

The present invention relates to a composition, comprising (i) a polypropylene having a melt flow index MFI(230° C., 2.16 kg) of less than 2.0 g/10 min, a flexural modulus of from 1200 to 2400 MPa, a density of from 0.895 to 0.910 g/cm 3 , (ii) a high-density polyethylene, and (iii) an inorganic filler.

First claim

The invention claimed is:

1. A blow molded article obtained from blow molding and cooling a melted blend of a composition comprising:
10 to 40 wt. %, based on the total weight of the composition, of a polypropylene having
a melt flow index MFI(230° C., 2.16 kg) of less than 2.0 g/10 min,
a flexural modulus of from 1200 to 2400 MPa, and
a density of from 0.895 to 0.910 g/cm 3 ,

(ii) 40 to 84 wt. %, based on the total weight of the composition, of a high-density polyethylene having a density of 0.94 to 0.97 g/cm 3 , and a melt flow index WI (190° C., 2.16 kg) of from 0.1 to 2.0 g/10 min, and
(iii) 5 to 30 wt. %, based on the total weight of the composition, of an inorganic filler comprising calcium carbonate surface treated with a hydrophobizing agent, wherein the calcium carbonate has a median particle diameter d 50 of from 0.5 to 5 μm, a BET specific surface area of from 1 to 15 m 2 /g before treatment with the hydrophobizing agent, and a d 98 value of from 3 to 30 μm,
wherein the blow molded article has a melt strength of from 29 to 54 cN, a notched Charpy impact strength at 23° C. of from 25 to 50 kJ/m 2 and a tensile modulus of at least 1000 MPa.

2. The blow molded article according to claim 1 , wherein the polypropylene is a heterophasic polypropylene comprising a matrix made of a propylene homo- and/or copolymer and an elastomeric phase dispersed in the matrix.

3. The blow molded article according to claim 2 , wherein the elastomeric phase is a propylene-ethylene copolymer or a propylene/C 4-8 alpha-olefin copolymer.

4. The blow molded article according to claim 2 , wherein the elastomeric phase is an ethylene-propylene rubber (EPR).

5. The blow molded article according to claim 2 , wherein the heterophasic polypropylene has an amount of xylene cold solubles (XCS) of from 3 to 35 wt %.

6. The blow molded article according to claim 2 , wherein the heterophasic polypropylene has an amount of comonomer units derived from ethylene and/or a C 4-8 alpha-olefin of from 1.5 to 30 wt %.

7. The blow molded article according to claim 1 , wherein the polypropylene has a melting point of at least 158° C., measured by differential scanning calorimetry (DSC).

8. The blow molded article according to claim 1 , wherein the high-density polyethylene has a polydispersity Mw/Mn of from 2 to 15.

9. The blow molded article according to claim 1 , wherein the inorganic filler comprises calcium carbonate and one or more of dolomite, talc, and clay.

10. The blow molded article according to claim 1 , wherein the inorganic filler is ground calcium carbonate (GCC) or precipitated calcium carbonate (PCC).

11. The blow molded article according to claim 1 , wherein the hydrophobizing agent is a C 8-24 fatty acid.

12. The blow molded article according to claim 1 , wherein the polypropylene is present in an amount of from 10 to 30 wt %, based on the total weight of the composition; the high-density polyethylene is present in an amount of from 40 to 75 wt %, based on the total weight of the composition; and the inorganic filler is present in an amount of from 5 to 20 wt %, based on the total weight of the composition.

13. The blow molded article according to claim 1 , wherein the composition has an amount of xylene cold solubles (XCS) of from 0.2 wt % to 8 wt %, and/or a melt flow index MFI(230° C., 2.16 kg) of 3 g/10 min or less.

14. The blow molded article according to claim 1 , wherein the blow molded article is a bottle, a wide-neck container, a canister or a drum.

15. The blow molded article according to claim 1 , having a melt strength of from 33 to 54 cN.

16. The blow molded article according to claim 1 , having a notched Charpy impact strength at 23° C. of from 30 to 45 kJ/m 2 .

17. The blow molded article according to claim 1 , having a tensile modulus of at least 1100 MPa.

Assignees

• Hersche Emil
• Burkhalter Rene
• Omya Int Ag

Inventors

• Hersche Emil
• Burkhalter Rene

Classifications

• B29K2105/16

  Fillers · CPC title

• C08L2203/10

  used for bottles · CPC title

• B29L2031/716

  of the wide mouth type, i.e. the diameters of the bottle opening and its body are substantially identical · CPC title

• B29L2031/7158

  Bottles · CPC title

• C08L23/10

  Homopolymers or copolymers of propene · CPC title