Several uncommon plasticizers and their production overview

(1) Citrate ester There are two main varieties of commonly used citrate ester plasticizers: tributyl citrate and acetyl tributyl citrate

Tributyl citrate is produced by the direct esterification of citric acid and butanol. Acetyl tributyl citrate can be obtained by reacting tributyl citrate with ester acid. Both are colorless and transparent oily liquids, non-toxic and mildew-proof. Can be used in food packaging materials. Often used in polyvinyl chloride and various fiber resins.

(2) Benzene polyesters Due to the development of petrochemical industry, polytoluene raw materials are provided. Environmentally friendly plasticizers oxidize them to obtain phenylene polyacids, which are then dehydrated to obtain Anhydride. Benzene polyesters can be obtained by esterifying benzene polyacids and their anhydrides with alcohols.

If R=C8H17, it is tri-n-octyl trimellitate (TOTM), and if R=C10H21, it is tri-n-decyl trimellitate.

They are colorless to light yellow viscous oily liquids with excellent heat resistance and durability, as well as good compatibility and low temperature resistance. Outstanding electrical insulation properties. It has attracted much attention in recent years.

(3) Pentaerythritol ester Generally there are two types:

The ether type is produced by the esterification of dipentaerythritol and C5~C7 fatty acids under the catalysis of sulfuric acid become. The ester type is formed by esterifying pentaerythritol, adipic acid, and fatty acids under the catalysis of sulfuric acid. Both are light yellow viscous oily liquids. Commonly used in polyvinyl chloride, it is a plasticizer that is heat-resistant, aging-resistant and exfoliation-resistant. It has low volatility and good electrical properties, but poor low temperature resistance.

(4) Amide plasticizers Representative varieties of this type of plasticizers such as dibutyl oleamide (DBO), regarding the properties and uses of various plasticizers See table.

1. Overview of the production of plasticizers

Due to the large amount of plasticizers and the wide variety of plasticizers, the current production technology of plasticizers tends to be two Development: On the one hand, there is the continuous large-scale production of main plasticizers. For example, the consumption of phthalate plasticizers accounts for about 80% of the entire plasticizers. The production volume is very large, and new plasticizers have emerged. Continuous large-scale production centered on dioctyl phthalate. At present, it generally reaches the level of single line production capacity of 20,000 to 50,000 t/a. The production capacity of BASF’s DOP continuous production device has reached 100,000 t/s. The biggest advantage of large-scale continuous production is economy.

On the other hand, there are many varieties of plasticizers, and the production volume of one variety is often small. Therefore, in order to adapt to the multi-variety and small-batch production of other plasticizers, general equipment is often used for intermittent production. . The so-called “universal” production device, a production device of Reichold Chemical Inc. in the United States is a typical example of this kind of “universal” production device. The device can handle more than 60 kinds of raw materials at ordinary times. It has 13 raw material storage tanks with separate pipes and 24 finished product receiving tanks. The reactor has a volume of 18 square meters and a production capacity of 13,000 to 16,000 t/a. It also has auxiliary equipment corresponding to the reactor volume such as a neutralizer (10m³), a stiller (2X380m³), a scrubber, a filter and a stripping tower. Can produce phthalate, adipate, azelaate, sebacate, US

maleate, fumarate, trimellitate, epoxy There are about 30 to 40 kinds of chemical compounds, polyesters and other plasticizers, equivalent to 95% of the commonly used plasticizers in the United States.