Ethylene glycol antimony catalyst

 First, Uses and types of catalysts for polyester

"Polyester" refers to in each molecule contains a class of many ester compounds, poly (ethylene terephthalate) (PET) is the most important type of polyester. It is widely used in the production of packaging materials, beverage bottles and textile and clothing products.

Polyester catalyst is used in the process of condensation reaction of "PTA/EG - polyester chip", which promotes the condensation reaction and improves the ability of condensation polymerization.

There are many kinds of catalysts used in the polymerization of polyester production, and the main catalysts are antimony, germanium and so on.Because antimony catalyst in condensation process can greatly promote the condensation reaction, and the thermal degradation reaction to promote to a lesser extent, so the current polyester industry commonly used antimony based catalysts, the main varieties have ethylene glycol antimony (SB2 (eg) 3), three oxidation antimony trioxide (Sb2O3), antimony acetate and so on.

Second, Advantages of ethylene glycol antimony

Ethylene glycol antimony (Sb2 (EG) 3) is the latest product of antimony series polyester catalyst, and it has obvious advantages in the following aspects as three oxidation two antimony and antimony acetate:

1. Ethylene glycol antimony is a kind of high efficient catalyst for condensation polymerization, which is higher than Sb2O3 and sb. Sb. It can improve the ability of condensation polymerization, shorten the time of condensation polymerization, and reduce the possibility of thermal degradation.In the actual production, it can reduce the vacuum load, so as to increase the output and improve the production capacity of the unit.
2. Ethylene glycol antimony high purity, no introduction of impurities, can make the chip to improve the intrinsic quality, improve the processing can be spun. And Sb2O3 and antimony acetate, can not be achieved.
3. Eliminate necessary for Sb2O3 in the reaction of high temperature and long time of dissolved (solubility is shown in Table 1), to prevent the formation of alcoholysis products and ester impurities.
4. The use of ethylene glycol antimony can improve the quality of the polymer and increase the PET's properties.

Third, The performance index and Matt brand of ethylene glycol antimony product quality

1. Product quality index

⑴ Molecular formula: C6H12O6Sb2, often writing Sb2(OCH2CH2O)3, or Sb2(EG)3, molecular weight: 423.67。

⑵ The appearance: white or white crystal powder on.

⑶ The hydrolytic stability: encountered moist air, decomposition of Sb2O3 and ethylene glycol. Products not soluble in water, soluble in ethylene glycol.

Table1 Comparison of solubility of Sb (CH3COO) () 3 in Sb2O3/ 3/Sb2 (EG)

2. Performance characteristics

Our factory plant the production of Sb2 (OCH2CH2O) 3 as a new catalyst for polyester industry, in the performance of a more obvious superiority, the specific performance comparison see table 2- table 4.

Appearance	White crystalline powder
Antimony content(wt)%	55-58
Chloride content%≤	0.01
Sulfate content%≤	0.01
iron content%≤	0.001
Arsenic content%≤	0.0015
Lead content%≤	0.001
Table 2 Sb2 (EG) 3 main quality indicators of our factory

 

project	Unit	indicators	Imported Sb2(EG)3	our Sb2(EG)3
Antimony content	PPM	55-58	56.91	55-58
Chloride content	PPM	≤100	≤100	≤100
Sulfate content	PPM	≤100	≤100	≤100
iron content	PPM	≤10	<8	<4
Arsenic content	PPM	－	<10	<10
Lead content	PPM	－	<16	<10
Table 3  Comparison of Sb2 (EG) 3 and imported Sb2 (EG) 3 in our factory

 

element	antimonous oxide	antimony acetate	ethylene glycol antimony
arsenic	1000	32	15
copper	10.1	﹤1	﹤1
iron	5.6	4.3	2
zinc	2.1	﹤1	﹤1
nickel	﹤1	﹤1	﹤1
lead	500	7.4	3
selenium	4	1.8	﹤1
chlorine	1.2	﹤1	﹤1
Table 4 Two / three oxidation antimony antimony acetate / ethylene glycol antimony trace metal content