Defoaming agent for papermaking

Abstract

The invention discloses a defoaming agent for papermaking, which comprises an active component, an emulsifier, an auxiliary agent, a solvent and water in a mass ratio of (25-35):(5-15):(15-25):(3-13):(27-37), and the active component is one or a combination of more of ethylene glycol monostearate, modified organic silicon and ethylene bisstearamide; and the modified organic silicon is prepared from an amino-terminated organic silicon intermediate, an organic silicon monomer and a silane coupling agent under the catalytic action of a basic catalyst. According to the defoaming agent, modified organic silicon serving as an active component of the defoaming agent is low in surface tension and excellent in wetting and spreading performance, meanwhile, due to introduction of amino groups, the molecular hydrophilicity is improved, the dispersity in water can be improved, the defoaming agent is used for defoaming a water-based system, the emulsification of the defoaming agent is promoted, in addition, the amino groups can be ionized to carry positive charges, and a good bubble breaking effect is achieved on a bubble film with negative electricity.

Description

technical field [0001] The invention relates to the technical field of defoamers, in particular to a defoamer for papermaking. Background technique [0002] The function of the defoamer is divided into defoaming and foam suppression. After the foam is generated, when the defoamer touches the foam, it immediately reacts with the hydrophobic segment molecules on the foam surface to form a double film layer. The surface tension of the defoamer is very low. Traction by the surrounding foaming film layer with high surface tension will cause the imbalance of the bubble stress, which will cause the bubble to burst. If the foam has not yet been produced, the defoamer can penetrate into the foaming system in the form of particles, destroying the elasticity of the bubble film, thereby inhibiting its formation. [0003] During the papermaking and pulping process, the slurry will generate a lot of surface active substances in situ. At the same time, the high mechanical force will cause...

AI Technical Summary

Problems solved by technology

[0003] During the papermaking and pulping process, the slurry will generate a lot of surface active substances in situ, and at the same time, the high mechanical force will cause a large amount of air to be mixed in, which is easy to generate air bubbles. When the foaming phenomenon is serious, the efficiency of pulp washing will be greatly reduced, and the It brings great difficulties to transportation and bleaching, affects the quality of pulp, seriously affects production efficiency, and increases the risk of environmental pollution. However, the traditional silicone defoamer has a low foam breaking rate in the actual use process. Therefore, The invention provides a defoamer for papermaking, which reduces the surface tension of the defoamer and improves the foam breaking rate

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