Activated alumina microspheres are products made from activated alumina after special treatment. With the properties of non-toxic, tasteless and non-powdering, the activated alumina microspheres are insoluble in water. The appearance is white spherical shape, with strong water absorption.
The general formula of the chemical structure of modified polydimethylsiloxane is as follows:
When R = R2 = R is phenyl, polyphenyl methyl siloxane is phenyl methyl
Although the base siloxane improves the compatibility with the coating base material, it can only provide a limited slipping effect on the coating film, and has no obvious effect on reducing the surface tension of the coating film, so it is used less in coatings.
Polyether modified polydimethylsiloxane when R and R2 are methyl and R is polyether
When chain, it is polyether modified polydimethylsiloxane. In the formula, the structure provides an increase
With a slippery effect, the polyether chain provides compatibility with the coating base material. At present, this type of product is the most common and widely used slip and anti-scratch agent in the coating industry at home and abroad. It has good effect, and has good compatibility with various coating base materials, oxidized ft wax glass has few side effects, and is not easy to cause paint film. Disadvantages, and a wide range of options for addition.
There are two different structures on the polyether chain of polyether modified polydimethylsiloxane: a. The polyether chain is connected to the main chain with the Si —0—C — structure, and the structural formula is:
This structure has hydrolytic instability, that is, when trace water and trace acid are inevitably present in the coating, the polyether chain will undergo the following hydrolysis:
As a result of the hydrolysis, the polyether-modified polydimethylsiloxane becomes polydimethylsiloxane with increased molecular weight, and the structure changes and makes it invalid.
The polyether chain is connected to the main chain with a Si-C structure, and the structural formula is: A =-H or-CH
The polyether-modified polydimethylsiloxane of this structure will not be hydrolyzed in the presence of a trace amount of water and a trace amount of acid.
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