Method for preparing hydroxyimino organosilicon compounds

Abstract

The invention provides a method for preparing hydroxyimino organosilicon compounds, which comprises the steps as follows: firstly, the mixture comprising RaSi(OR1)4-a and HON(R2)(R3) is heated; and secondly, by-products are removed under pressure-relief condition, wherein R refers to straight-chain or branched or ring-shaped saturated or unsaturated alkanes or aromatics or organic hydrocarbon containing other substituent groups, and the alkanes comprise 1 to 20 carbons; R1 refers to the alkanes comprising 1 to 6 carbons, and comprises methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl; R2 and R3 are the same or different alkanes comprising 0 to 10 carbons; and a is an integer ranging from 0 to 3. The preparation process cannot generate acidic materials so as to eliminate potential safety hazards, can also lead the reaction to be performed effectively, improves the effectiveness and the conversion rate of the reaction, reduces the reaction temperature, shortens the reaction time, can be used for preparing hydroxyimino organosilan, and is particularly suitable for synthesizing hydroxyimino silane that has high reaction activity and is sensitive to temperature.

Description

technical field [0001] The invention relates to a preparation method of an oxime-based organosilicon compound. The oxime-based organosilicon compound can be used as a crosslinking agent, a coupling agent and an additive for sealants or other industries. Background technique [0002] Oxime-based organosilicon compounds can be used as cross-linking agents, coupling agents and functional additives to cure and cross-link silicone materials, or to improve and adjust other properties; room temperature-curable silicone materials can be exposed to In the atmosphere, it reacts with water in the air to cross-link and solidify to become an elastomer, and in the case of isolation from water, it is stable in storage; this type of product is generally achieved by mixing a certain proportion of diorganopolysiloxane and cross-linking agent ; The silicone crosslinking agent has multiple hydrolyzable groups, such as alkoxy, oxime, amine, carboxyl, etc.; in addition, in many cases, according t...

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Problems solved by technology

[0003] Organoxime-based silanes are generally obtained by reacting corresponding organochlorosilanes with corresponding oximes. For example, a reaction with chlorosilane or chlorosiloxane and oxime is described in US3189576, and pyridine is used as a neutralizing agent; US4918209 A synthetic method using ammonia as a neutralizing agent is described; and in US4400527 and US4380660, organic oximes are not only used as reactants, but also act as acid absorbents; but the above methods all have complex processes and safety hazards; the coexistence of organic oximes and acidic substances often results in the existence of this danger. For example, the acidification of methyl ethyl ketone oxime and hydrochloric acid will decompose violently at a lower temperature and is difficult to control. Under certain circumstances, this type of compound has risk of explosion;

[0004] In another attempt, US4766231 provides a method for preparing organoalkoxyxime silane, which is obtained by reacting organoalkoxysilane and oxime in the presence of a catalyst. However, due to the solvent-free nature of the system, the reaction is not effective; in order to increase the conversion rate and yield of the reaction, one or more solvents are used in the reaction system, and the solvent not only provides the reaction and heating medium, and the solvent system can form an azeotrope with the removal molecule, which makes the reaction easier to carry out; for example, in US4705877, toluene is used for the reaction of aminopropyltrimethoxysilane and methyl ethyl ketone The corresponding oxime-based compounds are prepared by heating; however, due to the requirements of heating time and temperature, it is difficult to guarantee the quality of the product in order to obtain a high reaction conversion rate, especially for those with high reactivity and temperature sensitivity. substances, in particular;

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