Method for producing a polyolefin structure

Patent metadata

Field	Value
Publication number	US-10300648-B2
Application number	US-201414917528-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Sep 11, 2013
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

The production method for a polyolefin-based structure of the present invention produces a polyolefin-based structure from a mixed source material containing a polyolefin (A), an acid-modified polyolefin (B) and a gas barrier resin (C) using a molding machine 10, under the condition mentioned below. The molding machine 10 is equipped with a single-screw extruder 11, a die head 12, and an adaptor 13 for feeding the mixed source material from the single-screw extruder 11 to the die head 12. Am+10° C.≤T1≤Cm−10° C. (1), Cm−30° C.≤T2≤Cm+30° C. (2), Cm−10° C.≤T3≤Cm+50° C. (3), Cm−30° C.≤T4≤Cm+30° C. (4). T1 is a cylinder temperature in a section corresponding to a supply zone 21A and a compression zone 21B, T2 is a cylinder temperature in a section corresponding to a metering zone 21C, T3 is a temperature of an adaptor 13, T4 is a temperature of a die head, Am is the melting point of the component (A), and Cm is the melting point of the component (C).

First claim

The invention claimed is:

1. A method for producing a polyolefin-based structure from a mixed source material comprising 60 to 90% by mass of a polyolefin (A), 5 to 35% by mass of an acid-modified polyolefin (B) and 5 to 35% by mass of a gas barrier resin (C) composed of polyamide, using a molding machine, wherein:
the molding machine is equipped with a single-screw extruder which has a screw running inside a cylinder, a die head, and a communication portion for feeding the mixed source material from the single-screw extruder to the die head, and
the mixed source material is extruded out through the molding machine under the temperature condition satisfying the following (1) to (4) to give a polyolefin-based structure in which the gas barrier resin (C) is dispersed in a form of layers in the polyolefin (A):
Am+ 10° C.≤ T 1 ≤Cm− 10° C.  (1)

Cm− 30° C.≤ T 2≤ Cm+ 30° C.  (2)

Cm− 10° C.≤ T 3 ≤Cm+ 50° C.  (3)

Cm− 30° C.≤ T 4 ≤Cm+ 30° C.  (4)

wherein T 1 is a cylinder temperature in a section corresponding to a supply zone and a compression zone of the screw in the single-screw extruder; T 2 is a cylinder temperature in a section corresponding to a metering zone of the screw in the single-screw extruder; T 3 is a temperature of the communication portion; T 4 is a temperature of the die head; Am is a melting point of the polyolefin (A); and Cm is a melting point of the gas barrier resin (C).

2. The method for producing a polyolefin-based structure according to claim 1 , wherein the temperature T 2 is lower than the melting point Cm of the gas barrier resin (C).

3. The method for producing a polyolefin-based structure according to claim 1 , wherein the melting point (Cm) of the gas barrier resin (C) is higher than the melting point (Am) of the polyolefin (A) and the melting point difference (Cm−Am) is 20 to 150° C.

4. The method for producing a polyolefin-based structure according to claim 1 , wherein a temperature T 5 of the resin being extruded out through the discharge port of the die head satisfies the following formula (5):
Cm− 30° C.≤ T 5 ≤Cm− 5° C.  (5).

5. The method for producing a polyolefin-based structure according to claim 1 , wherein the screw has a barrier-type mixing section in the metering zone, and the temperature T 2 satisfies the following condition:
Cm− 30° C.≤ T 2 ≤Cm− 5° C.

6. The method for producing a polyolefin-based structure according to claim 1 , wherein the die head has two or more die holes.

7. The method for producing a polyolefin-based structure according to claim 1 , wherein the mixed source material contains 1 to 60% by mass of a recycled resin obtained from a resin solid generated in a production step for the polyolefin-based structure.

8. The method for producing a polyolefin-based structure according to claim 1 , wherein a melt flow rate of the polyolefin (A) is 0.01 to 10 (g/10 min).

9. The method for producing a polyolefin-based structure according to claim 1 , wherein a melt flow rate of the acid-modified polyolefin (B) is 0.1 to 10 (g/10 min).

10. The method for producing a polyolefin-based structure according to claim 1 , wherein an acid value of the acid-modified polyolefin (B) is 2 to 30 mg/g.

11. The method for producing a polyolefin-based structure according to claim 1 , wherein the gas barrier resin (C) is a metaxylylene group-containing polyamide.

12. The method for producing a polyolefin-based structure according to claim 11 , wherein a relative viscosity of the metaxylylene group-containing polyamide is 1.5 to 4.5.

13. The method for producing a polyolefin-based structure according to claim 11 , wherein a water content of the metaxylylene group-containing polyamide is 0.001 to 0.5%.

14. The method for producing a polyolefin-based structure according to claim 11 , wherein a free volume of the metaxylylene group-containing polyamide, as measured according to a positron annihilation technique, is 0.045 to 0.060 nm 3 .

15. The method for producing a polyolefin-based structure according to claim 1 , wherein the polyolefin-based structure is a hollow molded article.

16. The method for producing a polyolefin-based structure according to claim 1 , wherein the polyolefin-based structure is a sheet-molded article or a thermoformed article thereof.

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• Ishii Kentaro
• Kato Tomonori
• Mitadera Jun
• Kouno Kenji

Classifications

• B29C48/875 Primary

  for achieving a non-uniform temperature distribution, e.g. using barrels having both cooling and heating zones · CPC title

• B29C48/32

  with annular openings, e.g. for forming tubular articles · CPC title

• B29C48/0017

  combined with blow-moulding or thermoforming · CPC title

• B29C48/09

  Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels · CPC title

• B29C48/92 Primary

  Measuring, controlling or regulating · CPC title