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Method for recycling terephthalic acid using colored polyester

A technology of terephthalic acid and colored polyester, which is applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of multi-colored products, short elimination cycle, high scientific and technological content, and achieve a wide source of raw materials. , energy saving, low price effect

Active Publication Date: 2014-04-09
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although 75% of terephthalic acid is used to produce polyester fibers, polyester fibers are used to produce chemical fiber cloth and fabrics, and the elimination period is long, which is not conducive to recycling
[0004] Although only 25% of terephthalic acid in the market is used to produce bottle-grade polyester and film-grade polyester, the phase-out period is very short, especially for beverage bottles and packaging materials, which are especially suitable for recycling and recycling to more important production and life middle
However, most of the beverage bottles and packaging materials currently on the market have bright colors for the sake of aesthetics. Most of the traditional recycling processes are difficult to solve the problem that the product terephthalic acid has the color of the colored polyester raw material itself. The products obtained in this way Terephthalic acid cannot be reused to produce polyester
Moreover, the colored polyester beverage bottles in the market are either unrecycled, or the recycling price is very low, and the processors must first remove the colored bottles before disposing of these beverage bottles
[0005] However, the existing methods for processing colored polyester have high technological content and are too difficult to popularize; some are difficult to solve the problem of too many variegated products; Requires vacuum distillation, complex operation
These all limit the development of the current colored polyester recycling industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] 1. Clean the aluminized polyester film with yellow bronzing on the surface to remove labels and stains, dry it at 50°C, melt it at 270°C for 5 minutes, and then cool it to room temperature under the nitrogen atmosphere as a spare colored polymer. ester.

[0035] 2. Weigh 10g of the spare colored polyester obtained in step 1 and add it to the reactor, then add 100g of ethylene glycol and 0.03g of zinc acetate to the reactor; After heating and reacting for 5 hours, cool naturally to room temperature to obtain a solid-liquid mixture A, which is suction-filtered, and filter residue A and filtrate A are collected.

[0036] 3. Add 12 g of sodium hydroxide to the filtrate A obtained in step 2, and heat the reaction at 230° C. for 40 minutes under the conditions of condensing reflux and normal pressure to obtain a solid-liquid mixture B.

[0037] 4. Suction filter the solid-liquid mixture B obtained in step 3, and collect the filtrate B and solid component A.

[0038] 5. Take...

Embodiment 2

[0047] 1. Wash and remove the labels and stains of common Sprite beverage bottles on the market, dry them at 50°C, and crush them into pieces of about 5mm×5mm as spare colored polyester.

[0048] 2. Weigh 10g of the spare colored polyester obtained in step 1 and add it into the reaction kettle, then add 80g of ethylene glycol and 0.05g of zinc acetate into the reaction kettle; After 3 hours, it was naturally cooled to room temperature to obtain a solid-liquid mixture A, and the solid-liquid mixture A was suction-filtered to collect filter residue A and filtrate A.

[0049] 3. Add 13 g of sodium hydroxide to the filtrate A obtained in step 2, and heat the reaction at 240° C. for 50 minutes under the conditions of condensing reflux and normal pressure to obtain a solid-liquid mixture B.

[0050] 4. Suction filter the solid-liquid mixture B obtained in step 3, and collect the filtrate B and solid component A.

[0051] 5. Use filtrate B to replace ethylene glycol in step 2, repea...

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PUM

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Abstract

The invention discloses a method for recycling terephthalic acid using colored polyester. The method is characterized by comprising the following steps of preprocessing a colored polyester raw material; adding ethanediol and zinc acetate serving as a catalyst; heating under normal pressure; cooling; filtering to remove residue; adding sodium hydroxide to filtrate; heating under normal pressure to obtain a solid-liquid mixer; filtering to remove a solid component; repeating the steps above twice with filtrate replacing ethanediol to obtain two residues and two solid components; dissolving all solid components with distilled water; and mixing with filtrate obtained by filtering the two residues subjected to water washing so as to obtain mixed liquid; discoloring the mixed liquid with powdered activated carbon; filtering; heating the filtrate under boiling water bath; adding concentrated sulfuric acid to obtain white turbid liquid; centrifugally separating; washing a substrate; centrifugally separating to obtain neutral supernate; and drying to obtain terephthalic acid. The method has the advantages that the prepared terephthalic acid has the purity of about 99%, the platinum-cobalt color number is not greater than 10; the problem that the natural color of polyester raw material brings interference while prepared terephthalic acid is used for other purposes can be avoided.

Description

technical field [0001] The invention relates to a method for preparing high-purity terephthalic acid from waste colored polyester. Background technique [0002] Terephthalic acid is a widely used organic chemical raw material, which is widely used in various aspects of national production and life such as chemical fiber, light industry, electronics, and construction. At the same time, the application of terephthalic acid is relatively concentrated. About 90% of terephthalic acid in the world is used to produce polyethylene terephthalate (referred to as polyester). At present, 75% of terephthalic acid in the domestic market is used to produce polyester fiber, 20% is used to produce bottle-grade polyester (mainly used for packaging of various beverages and carbonated drinks), and 5% is used for film-grade polyester ( Mainly used in various packaging materials, films and tapes). [0003] Polyester fiber is commonly known as polyester. Polyester is used to make specialty mate...

Claims

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Application Information

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IPC IPC(8): C07C63/26C07C27/02
CPCC07C67/03C07C63/26
Inventor 岳正波刘洋彭书传王进
Owner HEFEI UNIV OF TECH