Polymer compositions for injection stretch blow molded articles

Patent metadata

Field	Value
Publication number	US-11174356-B2
Application number	US-201615335833-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Mar 30, 2011
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

A polymer composition of polypropylene copolymer and 1 to 50% by weight of hard resin. The polypropylene copolymer is either an impact copolymer or a random copolymer. The polymer composition can be used to make injection stretch blow molded articles having improved top load strength.

First claim

What is claimed is:

1. A method of making a polymer composition comprising:
blending a polypropylene impact copolymer including a matrix phase and a rubbery phase dispersed within the matrix phase with a hard resin to form the polymer composition, wherein the hard resin has a softening point, as measured according ASTM E-28, of from 60° C. to 180° C. and a melt flow rate (MFR) of from 1 to 50 g/10 min at 230° C., wherein the hard resin is selected from the group consisting of ketone resins, polyamide resins, colophonium, coumarone resins, terpene resins, or chlorinated aliphatic or aromatic hydrocarbon resins, and combinations thereof; and
extruding the polymer composition to form a substantially homogenous polymer blend, wherein the polymer blend contains 1 to 50% by weight of hard resin.

2. The method of claim 1 , wherein the polypropylene impact copolymer is an impact copolymer comprising a polypropylene homopolymer and an ethylene-propylene rubber.

3. The method of claim 2 , wherein the homopolymer comprises at least 60% by weight of the impact copolymer, and the ethylene-propylene rubber comprises less than 40% by weight of the impact copolymer.

4. The method of claim 2 , wherein the impact copolymer has a melt flow rate from 1 to 500 g/10 min.

5. The method of claim 1 , wherein the polypropylene copolymer is a random copolymer.

6. The method of claim 5 , wherein the random copolymer contains less than 10% by weight of an ethylene comonomer.

7. The method of claim 1 , wherein the polymer composition is used to make an injection stretch blow molded article.

8. A method of making an article comprising:
providing a polymer composition comprising a polypropylene impact copolymer including a matrix phase and a rubbery phase dispersed within the matrix phase and 1 to 50% by weight of hard resin, wherein the hard resin has a softening point, as measured according ASTM E-28, of from 60° C. to 180° C. and a melt flow rate (MFR) of from 1 to 50 g/10 min at 230° C., wherein the hard resin is selected from the group consisting of ketone resins, polyamide resins, colophonium, coumarone resins, terpene resins, or chlorinated aliphatic or aromatic hydrocarbon resins, and combinations thereof;
injection molding polymer composition into a preform; and
stretch-blowing the preform into an article.

9. The method of claim 8 , wherein the article is a container used in cold temperature applications of less than 40° F.

Assignees

• Fina Technology

Inventors

• Sun Luyi
• Coffy Tim
• Daniels Leland

Classifications

• C08L23/10 Primary

  Homopolymers or copolymers of propene · CPC title

• B29C49/0005

  characterised by the material · CPC title

• B29C2949/0872

  Weight · CPC title

• B29K2995/0077

  Yield strength; Tensile strength · CPC title

• C08L23/16

  Ethylene-propylene or ethylene-propylene-diene copolymers · CPC title