Method for after-treating polylactic acid and molding products thereof

A polylactic acid and molded product technology, which is applied in the field of crystallization of biodegradable materials, can solve the problems affecting the publicity and aesthetics of packaging materials, it is difficult for users to see the contents, and the transparency of finished products is reduced. Transparency, lower production cost, lower defective rate

Inactive Publication Date: 2011-03-30
TORAY FIBER RES INST(CHINA) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the present inventors have found that heat treatment in the above-mentioned temperature range will cause crystal growth to be difficult to control because the temperature is too high, so that the transparency of the finished product will be significantly reduced.
The inventor found that, especially for the field of packaging, it is difficult for users to see the contents of the package due to the decrease in transparency, which affects the publicity and aesthetics of the packaged materials.

Method used

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  • Method for after-treating polylactic acid and molding products thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment (1

[0030] Polylactic acid (4032D, Natureworks) was placed in a vacuum oven, dried at 80°C for 10 hours, and then mixed with ethylenebislauric acid amide (EBLA), 1,3,2,4-bis(4-methylbenzylidene)sorbate Alcohol (NC6, Mitsui Chemicals) co-extruded by twin-screw extruder, granulated into 4032D: masterbatch 1 of EBLA=95 / 5 (parts by weight), masterbatch 1 of 4032D / NC6=95 / 5 (parts by weight) 2. The temperature of the feeding section of the twin-screw extruder is 170° C., and the temperature of the other sections is 210° C. During the extrusion process, vacuum is exhausted.

[0031] The two masterbatches were placed in a vacuum oven, dried at 80°C for 10 hours, and then mixed with dried polylactic acid (4032D, Natureworks) in a certain proportion to form a mixture of 4032D / EBLA / NC6=98 / 1 / 1. The single-screw extruder of the T-shaped die is extruded and passed through the casting roll to obtain a film with a thickness of about 0.5mm. The temperature of the feeding section of the twin-scre...

Embodiment (2

[0056] Polylactic acid (4032D, Natureworks) was placed in a vacuum oven, dried at 80°C for 10 hours, and then mixed with ethylenebislauric acid amide (EBLA), 1,3,2,4-bis(4-methylbenzylidene)sorbate Alcohol (NC6, Mitsui Chemicals) co-extruded by twin-screw extruder, granulated into 4032D: masterbatch 1 of EBLA=95 / 5 (parts by weight), masterbatch 1 of 4032D / NC6=95 / 5 (parts by weight) 2. The temperature of the feeding section of the twin-screw extruder is 170° C., and the temperature of the other sections is 210° C. During the extrusion process, vacuum is exhausted.

[0057] The two masterbatches were placed in a vacuum oven, dried at 80°C for 10 hours, and then mixed with dried polylactic acid (4032D, Natureworks) in a certain proportion to form a mixture of 4032D / EBLA / NC6=98 / 1 / 1. The single-screw extruder of the T-shaped die is extruded and passed through the casting roll to obtain a film with a thickness of about 0.5mm. The temperature of the feeding section of the twin-scre...

Embodiment (3

[0073] Polylactic acid (4032D, Natureworks) was placed in a vacuum oven, dried at 80°C for 10 hours, and then mixed with ethylene bislauric acid amide (EBLA), 1,3,2,4-bis(4-methylbenzylidene)sorbate, respectively. Alcohol (NC6, Mitsui Chemicals) is co-extruded by a twin-screw extruder, granulated into the masterbatch 1 of 4032D: EBLA=95 / 5 (parts by weight), the masterbatch of 4032D / NC6=95 / 5 (parts by weight) 2. The temperature of the feeding section of the twin-screw extruder is 170° C., and the temperature of the other sections is 210° C. During the extrusion process, vacuum is exhausted.

[0074] The two masterbatches were placed in a vacuum oven, dried at 80°C for 10 hours, and then mixed with dried polylactic acid (4032D, Natureworks) in a certain proportion to form a mixture of 4032D / EBLA / NC6=98 / 1 / 1. The single-screw extruder of the T-shaped die is extruded and passed through the casting roll to obtain a film with a thickness of about 0.5 mm. The temperature of the feed...

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Abstract

The invention discloses a method for after-treating polylactic acid and molding products thereof, which comprises the following steps of: crystallizing the polylactic acid and the molding products thereof at the temperature of above glass transition temperature and below thermal decomposition temperature for the first time; and crystallizing the polylactic acid and the molding products thereof atthe temperature above the glass transition temperature and below the thermal decomposition temperature for the second time, wherein the second crystallization temperature is higher than the first crystallization temperature. The polylactic acid or the molding products are obtained by a special two-time crystallization process; and compared with the molding products prepared by the common crystallization method through a heat treatment process, the molding products prepared by the method have higher transparency and heat resistance so as to be widely applied to the fields of packing materials and the like.

Description

technical field [0001] The invention belongs to the field of polymer materials and packaging materials, in particular to a method for crystallizing biodegradable materials. Background technique [0002] In recent years, the consumption of polyethylene, polypropylene, polyester, nylon, etc., which are used as food and beverage containers, trays, etc., and commodity outer packaging materials has increased year by year. Along with this, the amount of post-use waste is also increasing. Incineration and landfilling of these wastes have caused various environmental problems. In order to solve these problems, biodegradable polymers have been increasingly used in recent years. Among them, polylactic acid is widely used in industry due to its relatively high melting point and relatively high mechanical properties. [0003] However, when polylactic acid is used as food and beverage containers, trays, etc., as well as commodity outer packaging boxes, in addition to requiring high tr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J3/00C08L67/04B29C71/02B29K67/00
Inventor 夏天赖铮铮
Owner TORAY FIBER RES INST(CHINA) CO LTD
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