Preparation method of silicon compound with oxetanyl group

Abstract

Provided is a process for efficiently producing a cationically curable condensed silicon compound. There was an unsolved problem that, in a condensation reaction, an oxetanyl group is subjected to ring-opening under acidic conditions, while gelation is easily caused under alkaline conditions. It was found that a silicon compound (C) having an oxetanyl group can be obtained without causing gelation even at a high concentration by a production process including a first step of separately subjecting a silicon compound (A) having four siloxane bond-forming groups and a silicon compound (B) havingan oxetanyl group to an alcohol exchange reaction with 1-propanol and a second step of subjecting silicon compounds (AP) and (BP) undergone the first step to hydrolytic copolycondensation under alkaline conditions at a specific ratio.

Description

technical field [0001] The present invention relates to a preparation method of a silicon compound having an oxetanyl group. More specifically, the present invention relates to a production method capable of producing at a high concentration a silicon compound having a composition that gels during a reaction in a conventional production method without causing gelation. Background technique [0002] It has been known that both acidic and basic conditions have a catalytic effect in the hydrolytic condensation of a silicon compound having a hydrolyzable group, but the chemical mechanism of condensation differs between acidic and basic conditions. For example, Non-Patent Document 1 records that: SiX 4 Tetraethoxysilane, a type of silicon compound, will be hydrolyzed by either acid or basic catalyst, but it belongs to RSiX 3 Type monomethyltriethoxysilane reacts with acid catalysts, but basically does not react with basic catalysts. [0003] Patent Document 1 describes that an...

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Problems solved by technology

[0006] However, in Comparative Example 1 of Patent Document 3, it is disclosed that a silicon compound having an oxetanyl group and three hydrolyzable groups and a silicon compound having three siloxane bond forming groups are reacted under basic conditions. Since gelation occurs during hydrolytic co-condensation, it is known that gelation occurs when a silicon compound having an oxetanyl group and three hydrolyzable groups is subjected to hydrolytic condensation under alkaline conditions

[0007] In addition, in Patent Document 3, Example 8 exemplifies a specific example of cocondensing a silicon compound having four siloxane bond-forming groups and a silicon compound having three hydrolyzable groups using an acidic catalyst, but by hydrolysis The evaluation of the cured product of the silicon compound obtained by copolycondensation was not different from the case of using a silicon compound having three siloxane bond forming groups

That is, it can be said that for the co-condensation of a silicon compound having an oxetanyl group and three hydrolyzable groups with a silicon compound having four siloxane bond forming groups under basic conditions, there are known Documents that suggest the possibility of gelation and existing documents that suggest that special effects cannot be expected

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