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Recycling method of waste silicone rubber

A silicone rubber and waste technology, applied in the field of three-waste treatment, can solve the problems of easy blockage, poor safety and small adaptability of pipelines, and achieve the effect of overcoming easy blockage of pipelines, poor safety and small adaptability range.

Inactive Publication Date: 2012-08-22
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among the many base catalysts, KOH is the most commonly used strong base catalyst for cracking waste silicone rubber to recover DMC. When KOH is used as the depolymerization catalyst, the quality of DMC obtained is high and the equipment corrosion is small. However, the process has the following There are several problems: first, the consumption of catalyst is large, and the production of 1 ton of crude DMC needs to consume 700-750 kg KOH; second, the safety is poor, because local reactions are prone to excessive local reactions in the reactor, which may cause combustion and explosion accidents; third, The scope of application is small, and the KOH used as a catalyst is only suitable for depolymerization of button scraps and mold glue, not for glass glue
In a word, although the cracking of waste silicone rubber by sulfuric acid catalysis is milder than the alkali catalysis method, the possibility of combustion and explosion is relatively small, and the production is relatively safe; More importantly, the DMC composition of the product is unstable, the content of various organic silicon monomers varies greatly, and the quality is also poor, which affects product sales.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0017] Example 1SO 4 2- / Al 2 o 3 -TiO 2 Preparation of Composite Solid Superacid

[0018] 1kg TiCl with a mass ratio of 1:1 4 , AlCl 3 Add them into water respectively, control the pH value until the solution is clear; add ammonia solution dropwise to the mixed solution under rapid stirring until the pH of the solution is around 9, place the obtained solution for aging, filter, wash and dry after 4 hours, and pulverize Afterwards, impregnate with 1mol / L sulfuric acid solution for 30 minutes, then filter, dry, sieve (100 mesh), and finally roast to obtain SO 4 2- / Al 2 o 3 -TiO 2 Complex solid acid.

example 2

[0019] Example 2SO 4 2- / Fe 2 o 3 -TiO 2 Preparation of Composite Solid Superacid

[0020] 1kg FeCl with a mass ratio of 1:1 3 、TiCl 4 Add them into water respectively, control the pH value until the solution is clear; add ammonia solution dropwise to the mixed solution under rapid stirring until the pH of the solution is around 9, place the obtained solution for aging, filter, wash and dry after 4 hours, and pulverize Afterwards, impregnate with 1mol / L sulfuric acid solution for 30 minutes, then filter, dry, sieve (100 mesh), and finally roast to obtain SO 4 2- / Fe 2 o 3 -TiO 2 Complex solid acid.

example 3

[0021] Example 3 Preparation of DMC by Cracking Buttons, Leftovers, and Waste Silicone Rubber

[0022] 400g of waste silicone rubber particles of button class scraps after crushing and 3gSO 4 2- / Al 2 o 3 -TiO 2 After the composite solid acid catalyst is mixed evenly in the stirring mixer, it is added to the cracking reaction kettle, heated under stirring, and the cracking temperature is controlled at about 130°C. After 4 hours of cracking, the crude product DMC is distilled and collected. After 7 hours, the reaction is stopped, and the cracking is released by heating. residue. In the crude product DMC (about 250g) that distills out, add 0.5g 1mol / L sulfuric acid, be heated to 120 ℃, add the terminator KOH aqueous solution of 0.5g1mol / L after reaction 2 hours, obtain high-quality DMC ( about 200g), where D 4 About 156g, D 5 About 20g, D 6 About 10g, D ＞7 About 14g, the content of MM is below 0.01%.

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PUM

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Abstract

The invention provides a recycling method of waste silicone rubber, which comprises the following processes of: preparation of solid acid, catalytic cracking of the waste silicone rubber, post-treatment and separation of respective units, wherein the catalytic cracking comprises the following steps of: cracking at 120-150 DEG C for 3-4 hours after crushed waste silicone rubber and a 0.5-5% solid acid catalyst are uniformly mixed, distilling and separating after the cracking reaction, and collecting a crude product DMC (DiMethyl Carbonate); and the post-treatment comprises the following steps of: adding an inorganic acid catalyst into the crude product DMC to react at 100-140 DEG C for 2-3 hours, adding an alkali solution to terminate the reaction, and finally, rectifying and separating toobtain high-quality DMC. When the method is adopted, the recycling rate can stably reach over 50% in terms of silicon rubber, wherein the content of MM can be controlled below 0.01%; the recycling method can be directly applied to the polymerization of the silicon rubber without influencing the quality of the silicon rubber.

Description

1. Technical field [0001] The invention relates to a method for treating three wastes, in particular to a method for recycling solid waste, in particular to a method for recycling waste silicone rubber. 2. Background technology [0002] Silicone rubber has many unique properties such as non-toxic and tasteless, high and low temperature resistance, electrical insulation and physiological inertia. It is incomparable and replaceable by other organic polymer materials, so it is widely used in aerospace, chemical industry, agriculture, medical and health, etc., and has become an important and indispensable new polymer material for the national economy. With the rapid development of the silicone rubber industry and the rapid growth of consumption, the waste silicone rubber raw rubber produced in the synthesis process, the silicone rubber waste and leftovers formed in the vulcanization molding process, and the waste silicone rubber formed in the application process Products are ra...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J11/16C08L83/04C08G77/04
CPCY02W30/62
Inventor 许华建吴伟章丰丰齐洪侠冯乙巳
Owner HEFEI UNIV OF TECH