Injection stretch blow molded articles and random copolymers for use therein

Patent metadata

Field	Value
Publication number	US-10113020-B2
Application number	US-201514735329-A
Country	US
Kind code	B2
Filing date	Jun 10, 2015
Priority date	Mar 26, 2009
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A polymer composition adapted for use in injection stretch blow molding may include a metallocene random propylene-based copolymer in the absence of a clarifier. The metallocene random propylene-based copolymer may exhibit a melting point of from 105° C. to less than 175° C., a recrystallization temperature ranging from 85° C. to 100° C. as measured by DSC, a microtacticity ranging from 89% to 99%, a molecular weight (Mw) ranging from 170,000 to 210,000, and a melt flow rate of from about 1 dg/min. to about 40 dg/min. A method of forming an injection stretch blow molded (ISBM) article may include providing the metallocene random propylene-based copolymer, injection molding the metallocene random propylene-based copolymer in the absence of a clarifier into a preform, and stretch-blowing the preform into an article.

First claim

What is claimed is:

1. A method of forming an injection stretch blow molded (ISBM) article comprising:
providing a metallocene random propylene-based copolymer, wherein the metallocene random propylene-based copolymer has a melting point of from about 115° C. to about 175° C., a microtacticity of from about 89% to 99%, a molecular weight (Mw) of 170,000 to 210,000, and a recrystallization temperature of from 85° C. to 100° C., as measured by DSC;
injection molding the metallocene random propylene-based copolymer in the absence of a clarifier into a preform; and
stretch-blowing the preform into an article.

2. The method of claim 1 , wherein the article is stretch-blown at a production rate of at least about 1000 articles per hour per cavity.

3. The method of claim 2 , wherein the article is stretch-blown at a production rate of at least about 1500 articles per hour per cavity.

4. The method of claim 1 , wherein the metallocene random propylene-based copolymer exhibits a melt flow rate of from about 1 dg/min. to about 40 dg/min.

5. The method of claim 1 , wherein the article is selected from the group consisting of medical packaging or cosmetic packaging.

6. The method of claim 1 , wherein the stretch-blowing is performed at a pressure of 8 bar.

7. The method of claim 1 , wherein the stretch-blowing requires a heat energy of at least 20% less than the heat energy required for similar stretch-blowing of a non-metallocene random propylene-based copolymer.

8. The method of claim 1 , wherein the metallocene random propylene-based copolymer exhibits a top load of at least 100 N at a weight of 23 g, a haze of less than 5%, and a gloss at 45° of greater than 75%.

9. A method of forming an injection stretch blow molded (ISBM) article comprising:
providing a metallocene random propylene-based copolymer, wherein the metallocene random propylene-based copolymer has a melting point of from about 105° C. to about 130° C., a melt flow rate of from about 1 dg/min. to about 40 dg/min, a recrystallization temperature of from 85° C. to 100° C., as measured by DSC, a microtacticity of from about 89% to 99%, and a molecular weight (Mw) of 170,000 to 210,000;
injection molding the metallocene random propylene-based copolymer in the absence of a clarifier into a preform; and
stretch-blowing the preform into an article.

Assignees

• Fina Technology

Inventors

• Sun Luyi
• Leland Mark

Classifications

• Y10T428/1397

  Single layer [continuous layer] · CPC title

• B29C49/10

  using mechanical means {for prestretching} · CPC title

• C08L23/14 Primary

  Copolymers of propene (C08L23/16 takes precedence) · CPC title

• C08L2201/10

  Transparent films; Clear coatings; Transparent materials · CPC title

• C08K3/01

  characterized by their specific function · CPC title