A dealcoholized transparent silicone sealant with long shelf life

Abstract

The invention discloses a dealcoholized transparent silicone sealant with a long storage period, which relates to the field of sealants. In parts by mass, the transparent silicone sealant comprises 100 parts of alkoxylated polydisiloxane polymer, 10-20 parts of hydrophilic white carbon black, 0.5-15 parts of methoxysilane, 0.2-10 parts of oxygen ether, 0.8-10 parts of viscosity-increasing stabilizer, 0.05-0.3 parts of organotin catalyst, 0-40 parts of plasticizer agents and accelerators. The oxygen ether in the present invention can increase the compatibility of hydrophilic white carbon black and hydrophobic type end-capping organosilicon material organosilicon material, promote the rapid reaction of hydrophilic type white carbon black and hydrophobic type end-capping organosilicon material, and make alkane Oxysilane can quickly and efficiently react with moisture in hydrophilic silica and convert lower alcohols, which can be completely removed by vacuum, thereby quickly and effectively removing moisture, and the cost is low.

Description

technical field [0001] The invention relates to the field of sealants, in particular to a dealcoholized transparent silicone sealant with a long storage period. Background technique [0002] Dealcoholized transparent silicone sealant (hereinafter referred to as "RTV1") is widely used for its advantages of no odor, good adhesion, no corrosion to metal, and adjustable curing speed. RTV1 can be used in the absence of moisture. Storage stable for at least 6 months, it cures quickly to a tack-free elastomer when exposed to moisture. [0003] A typical RTV blend is usually based on a polydimethylsiloxane base polymer terminated with dialkoxyalkyl and silyl groups, the filler is white phase silica, and the crosslinker is methyltrimethoxy base silane, the metal catalyst is a titanium or tin compound, and the polydimethyl polyalkoxy group of the silyl group can be cross-linked by the moisture in the atmosphere. The white phase silica contains a certain amount of moisture, which will...

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Problems solved by technology

The main reason is that during the storage process, the free methanol in the system has a synergistic effect with the metal catalyst, and the subsequent reaction of the hydroxyl functional substance produces by-products that cannot be cross-linked, resulting in slow curing or even failure of the material

[0006] U.S. Patent No. 5,828,200 discloses an improved polyalkoxysilyl-terminated RTV, which uses silicon nitrogen compounds or epoxy silanes as hydroxyl and moisture scavengers, but the silicon nitrogen compounds or epoxy silanes The preparation is difficult and the price is high, and the reaction between the silicon nitrogen compound and the hydroxyl group will produce nitrogen and other by-products, which not only have an unpleasant taste, but also corrode the equipment or substrate; use alkoxysilane as a hydroxyl and moisture removal When used as an agent, the hydrolysis rate of alkoxysilane is very slow, and the compatibility with water is poor. Therefore, not only is the efficiency low in the treatment of hydrophilic silica water, but also the methanol produced after hydrolysis has a negative effect on the storage of alcohol-based glue. have fatal effects

[0007] The literature "Research on Hydrophobic Treatment of Silica by Dimethyldimethoxysilane" proposes to use dimethyldimethoxysilane to treat silica in the presence of trace amounts of amines, with high efficiency and 100% hydrophobicity , but the raw materials of dimethyldimethoxysilane are not easy to obtain, and the price is relatively high

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