A kind of silicone composition

Abstract

The invention relates to a silicone defoaming composition, which comprises the hydrosilylation reaction of dimethylhydrogen-terminated vinyl polyorganosiloxane and hydrogen-containing polyorganosiloxane and alkali treatment, through which dimethyl hydrogen The group-terminated vinyl polyorganosiloxane can effectively control the cross-linking viscosity and form a fluid dynamic cross-linked polymer with a spatial structure. The organopolysiloxane defoamer composition can be prepared with the above-mentioned polymer as the main body, and in It has good defoaming and antifoaming properties in high temperature and strong alkali systems, and is suitable for strong alkali systems.

Description

Technical field [0001] The present invention involves a cross -linked organic polysiloxane foam composition, which is a fine chemical preparation technology field. Background technique [0002] The papermaking industry is an important industry that is closely related to the development of the national economy. Although the amount of foaming agents in the papermaking industry is small, it plays an extremely important role.In the process of papermaking industry slurry, because the slurry contains a large amount of fatty acid soap, resin acid soap to foam substance, plus the foaming material of the cellulose, the transportation of the slurry is prone to produce a large amount of foam, which brings unnecessary to production.The troubles and losses, alkaline slurry also brings healthy problems to production workers.Early paper mills adopted the method of "clear water bubbles" to inhibit the generation of foam, but the effect was not ideal.With the rise of the silicon industry and the ...

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Problems solved by technology

[0003] As early as 1968, research on the preparation of organopolysiloxane defoamers had already begun abroad. For example, in US3383327, polydimethylsiloxane was used as the main body to prepare defoamer compositions. However, due to its single structure, Foam suppression performance is poor

In later studies, US3455839 described a method for preparing a crosslinkable organopolysiloxane defoamer composition, and proposed for the first time the process of using vinyl polysiloxane to react with hydrogen-containing polysiloxane to improve The anti-foaming ability of the defoaming agent in the later stage is improved, but it still has some deficiencies in the defoaming performance; US4690713 points out that vinyl groups and phenyl groups have been introduced into polyorganosiloxane, and in the platinum catalyst catalyzed Cross-linking with hydrogen-containing polysiloxane under certain conditions to obtain a defoamer composition, but its antifoaming performance cannot fully meet the actual needs of production; US4639489 uses high-viscosity hydroxyl-terminated polysiloxane and polyethyl silicate The organopolysiloxane defoamer is prepared by reaction under alkali-catalyzed conditions, but due to the relatively high viscosity of the prepared organosilicon polymer, it does not have good defoaming performance; WO2013043487 states the use of organopolysiloxane containing hydroxyl Siloxane cross-links with organopolysiloxanes containing amino groups in the end chains, and prepares defoamer compositions. However, its cross-linking structure is relatively weak, and it is difficult to play a good inhibitory effect in strong alkali systems. Bubble action

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