Blow molded article with good mechanical and optical properties

Patent metadata

Field	Value
Publication number	US-9587097-B2
Application number	US-201415104489-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 18, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Blow molded article comprising a propylene copolymer having a MFR 2 (230° C.) in the range of more than 2.0 to 12.0 g/10 min, a comonomer content in the range of 4.0 to below 4.0 mol.-%, a melting temperature in the range of 125 to below 143° C., and a xylene cold soluble fraction (XCS) in the range of above 15.0 to 40.0 wt.-%.

First claim

The invention claimed is:

1. Blow molded article comprising at least 75.0 wt. % based on the total weight of the blow molded article, of a propylene copolymer (R-PP), wherein the blow molded article and/or the propylene copolymer (R-PP) has/have:
(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of more than 2.0 to 12.0 g/10 min,
(b) a comonomer content in the range of 4.0 to below 14.0 mol. %,
(c) a melting temperature in the range of 125 to below 143° C., and
(d) a xylene cold soluble fraction (XCS) in the range of above 15.0 to 40.0 wt. %.

2. Blow molded article according to claim 1 , wherein the comonomer of the propylene copolymer (R-PP) is selected from ethylene, C 4 to C 12 α-olefin, and mixtures thereof.

3. Blow molded article according to claim 1 , wherein said propylene copolymer (R-PP) has:
(a) a glass transition temperature in the range of −12° C. to +2° C.; and/or
(b) no glass transition temperature below −20° C.

4. Blow molded article according to claim 1 , wherein said propylene copolymer (R-PP) has:
(a) a molecular weight distribution (Mw/Mn) of at least 2.7; and/or
(b) a polydispersity index (PI) of at least 2.3.

5. Blow molded article according claim 1 , wherein said propylene copolymer (R-PP):
(a) has 2,1 regio-defects of at least 0.2% determined by 13 C-NMR spectroscopy; and/or
(b) is monophasic.

6. Blow molded article according to claim 1 , wherein the blow molded article comprises said propylene copolymer (R-PP) in an amount of at least 80.0 wt. %, based on the total weight of the blow molded article.

7. Blow molded article according to claim 1 , wherein the blow molded article has a bottle appearance factor (BAF) before sterilization of in-equation (I):
BAF>180  (I),

wherein:
BAF is defined as:

BAF
-

C
⁢

⁢
x
⁢

⁢
G

R

wherein:
H is the haze value,
C is the clarity value,
G is the gloss value,
wherein further the haze, the clarity and the gloss are determined according to ASTM D 1003-07 on a test specimen cut from a bottle having a wall thickness of 0.3 mm made from said propylene copolymer (R-PP).

8. Blow molded article according to claim 1 , wherein said propylene copolymer (R-PP) comprises two fractions, a first propylene copolymer fraction (R-PP1) and a second propylene copolymer fraction (R-PP2), said first propylene copolymer fraction (R-PP1) differs from said second propylene copolymer fraction (R-PP2) in the melt flow rate MFR 2 (230° C.) and/or in the comonomer content.

9. Blow molded article according to claim 8 , wherein
(a) the weight ratio between the first propylene copolymer fraction (R-PP1) and the second propylene copolymer fraction (R-PP2) [(R-PP1):(R-PP2)] is 70:30 to 30:70; and/or
(b) the comonomers for the first propylene copolymer fraction (R-PP1) and the second propylene copolymer fraction (R-PP2) are selected from ethylene, C 4 to C 12 α-olefin, and mixtures thereof.

10. Blow molded article according to claim 8 , wherein:
(a) the first propylene copolymer fraction (R-PP1) is the comonomer lean fraction and the second propylene copolymer fraction (R-PP2) is the comonomer rich fraction; and/or,
(b) the first propylene copolymer fraction (R-PP1) has a lower melt flow rate MFR 2 (230° C.) than the second propylene copolymer fraction (R-PP2).

11. Blow molded article according to claims 8 , wherein:
(a) the first propylene copolymer fraction (R-PP1) has a lower comonomer content than the propylene copolymer (R-PP); and/or,
(b) the first propylene copolymer fraction (R-PP1) has a lower melt flow rate MFR 2 (230° C.) than the propylene copolymer (R-PP).

12. Blow molded article according to claim 8 , wherein
(a) the first propylene copolymer fraction (R-PP1) has a comonomer content in the range of 0.5 to 8.0 mol % based on the first propylene copolymer fraction (R-PP1); and/or,
(b) the second propylene copolymer fraction (R-PP2) has a comonomer content in the range of more than 8.0 to 20.0 mol % based on the second propylene copolymer fraction (R-PP2).

13. Blow molded article according to claim 8 , wherein:
(a) the first propylene copolymer fraction (R-PP1) has a melt flow rate MFR 2 (230° C.) in the range of 1.5 to 8.0 g/10 min; and/or,
(b) the second propylene copolymer fraction (R-PP2) has a melt flow rate MFR 2 (230° C.) in the range of more than 2.0 to 20.0 g/10 min.

14. Blow molded article according to claim 8 , wherein:
(a) the first random propylene copolymer fraction (R-PP1) and the second random propylene copolymer fraction (R-PP2) fulfill together the inequation (IV):

MFR
⁡

(

R
-

PP
⁢

⁢
2

)

MFR
⁢

⁢

(

R
-

PP
⁢

⁢
1

)

≥
1.1

(
IV
)

wherein:
MFR (R-PP1) is the melt flow rate MFR 2 (230° C.) [g/10 min] of the first propylene copolymer fraction (R-PP1),
MFR (R-PP2) is the melt flow rate MFR 2 (230° C.) [g/10 min] of the second propylene copolymer fraction (R-PP2); and/or,
(b) the first random propylene copolymer fraction (R-PP1) and the random propylene copolymer fraction (R-PP) fulfill together the inequation (VI):

MFR
⁢

Assignees

• Borealis Ag

Inventors

• Wang Jingbo
• Klimke Katja
• Doshev Petar
• Pham Tung

Classifications

• B29C49/04114

  for keeping constant thickness · CPC title

• B29C49/0005 Primary

  characterised by the material · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• B29C49/04

  Extrusion blow-moulding · CPC title

• B29K2105/0094

  having particular viscosity · CPC title