Method for preparing high-purity diesters of terephthalate acid from polyethylene terephthalate wastes

A technology for ethylene phthalate and phthalate diester, which is applied in the field of preparing terephthalate diester, can solve the problems of low practicability, large oil-water separator equipment and the like, and achieves economical reaction time and low energy. , the effect of reducing industrial production costs

Active Publication Date: 2012-07-25
CHANG CHUN PLASTICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method can obtain high-component diester products, it requires a huge oil-water separator equipment; and the product must be washed with water; this patent document does not involve the hue of the product, so it is not commercially practicable

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] In an autoclave equipped with a stirrer, thermometer, pressure gauge, oil-water separator, flow controller and condenser, 300 g of unwashed PET protective film (obtained from Chimei Electronics Co., Ltd.) fragments, 712 grams of 2-ethylhexanol, 0.6 grams of zinc oxalate, and 0.6 grams of tetrabutyl titanate were put into the reaction kettle. The reaction kettle is fully stirred under nitrogen flow and pressurized to a gauge pressure of 2.0kg / cm 2 , the reaction temperature was raised to 230°C, and the final gauge pressure was stabilized at 4.5kg / cm 2 After 2.5 hours of reaction, the pressure was gradually released and cooled to 200°C. Next, vacuum is applied to reduce the pressure from normal pressure to 660 mm Hg, and 250 grams of pure water is introduced into the bottom of the reactor at a constant speed through a flow controller, and the oil-water separation is continuously distilled at a reaction temperature of 180-200°C In the reactor, the lower layer of ethylene...

Embodiment 2

[0037] Except that the catalyst tetrabutyl titanate was replaced by zinc acetate, other reaction equipment, process and formula were the same as in Example 1. Crude ester product 595 grams (productive rate=97.5%); Crude ester product is obtained DOTP (diisooctyl terephthalate) / PET oligomer=98.1 / 1.9 (area ratio) through gel permeation chromatography analysis, The purity is therefore 98.1%. The crude ester product is distilled under the conditions of a vacuum degree of <2 mmHg and a distillation temperature of 235° C., and the obtained DOTP is an odorless product with a hue (platinum-cobalt) of 15 and an acid value of 0.18 mg KOH / g.

Embodiment 3

[0039] With the same reaction equipment as in Example 1, 300 grams of unwashed PET protective film fragments, 569 grams of 2-ethylhexanol, 0.3 grams of zinc oxalate, and 0.6 grams of tetrabutyl titanate were put into the reaction in the cauldron. The reaction kettle is fully stirred under nitrogen flow and pressurized to a gauge pressure of 2.0kg / cm 2 , the reaction temperature was raised to 230°C, and the final gauge pressure was stabilized at 3.8kg / cm 2 After 2.5 hours, gradually release the pressure and cool to 200°C. Next, vacuum is applied to reduce the pressure from normal pressure to 660 mm Hg. 400 grams of pure water is introduced into the bottom of the reactor through a flow controller at a constant speed. The reaction temperature is between 200-210°C and continuously distilled and collected in the oil-water separator. , the lower layer of ethylene glycol aqueous solution comes out from the bottom of the separator, and the upper layer of 2-ethylhexanol returns to th...

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Abstract

The invention provides a method for preparing high-purity bis-terephthalate from polyethylene terephthalate wastes. The method comprises the following steps of: using polyethylene terephthalate (PET) waste and aliphatic saturated monoalcohol to pass through the processes of alcoholysis reaction, ester exchange reaction and purification under the existence of oxalate catalyst, thus obtaining the high-purity bis-terephthalate. The prepared bis-terephthalate can be used as a plasticizer. As the PET wastes are used as initiator, the invention can alleviate the negative effects of the PET wastes to the environment, and can reduce the petrochemical material consumption and the preparation cost of the bis-terephthalate.

Description

technical field [0001] The present invention relates to a method for preparing terephthalic acid diester from self-recovered polyester waste, in particular to a method of self-recovered polyester waste, which uses oxalate as a catalyst to prepare high Method of Purity Terephthalate Diester Plasticizers. Background technique [0002] Polyethylene terephthalate (PET) polyester resin is widely used in beverage containers, packaging films and textile fiber industries due to its good plasticity and blow molding properties. However, a large amount of waste produced after the use of processed beverage containers, films and fibers, or by-products produced during processing will have a serious impact on the global environment. Therefore, in the past, there were various recycling methods such as recycling of side materials, physical recycling and chemical recycling. [0003] The recycling of polyester waste can be recycled through physical methods, such as crushing or extruding gran...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/82C07C67/03
Inventor 王慈仁林永昇杨崇基
Owner CHANG CHUN PLASTICS CO LTD
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