A kind of room temperature curing flame retardant silicone sealant and preparation method thereof

Abstract

The invention discloses a room-temperature curable flame-retardant silicone sealant and a preparation method thereof. The flame-retardant silicone sealant comprises the following compositions in parts by weight: 100 parts of hydroxyl end-blocked dimethylsiloxane, 0-40 parts of fumed silica, 100-500 parts of an inorganic metal hydroxide flame retardant, 10-200 parts of an organic phosphorus flame retardant, 1-30 parts of an organic silicon crosslinker, 0.1-2 parts of a coupling agent and 0.1-10 parts of a catalyst. The preparation method is simple and practicable, and easy to implement. The flame-retardant silicone sealant and preparation method thereof disclosed by the invention have the beneficial effects that the prepared room-temperature curable flame-retardant silicone sealant does not produce poison gas in the process of burning, and has good flexibility, good storage stability, and good adhesion.

Description

technical field [0001] The invention belongs to the technical field of sealants, in particular to a room-temperature-cured flame-retardant silicone sealant and a preparation method thereof. Background technique [0002] Room temperature curing silicone sealant is a paste under the condition of isolating water vapor, and reacts and solidifies into an elastomer after meeting water at room temperature. Usually this composition is called RTV-1, which is widely used in the construction industry for sealing agents and adhesives. The basic silicone RTV-1 sealant contains: polysiloxane, plasticizer, reinforcing filler, crosslinking agent, coupling agent, catalyst. It can also contain colorants, thixotropic agents, flame retardants, etc. In many occasions, such as fire doors and windows, building fire partitions, electrical products, etc. The sealant is required to have the function of flame retardant and fire retardant. [0003] The fire and flame retardant function of the seala...

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Problems solved by technology

This kind of flame retardant sealant has the problem of poor elasticity. Usually, the way to improve the elasticity of the sealant is to add plasticizer, but the addition of plasticizer will affect the flame retardant performance. It is not suitable for occasions that require elasticity before sealing. Due to the need to add platinum and chrome compounds, the formulation cost of the sealant is high

[0005] The flame retardant sealant formulated with halogenated hydrocarbons (such as decabromodiphenyl ether) and antimony trioxide composite flame retardant has good flame retardant effect and the performance of the sealant can also be maintained, but this kind of flame retardant contains Halogen, emits toxic fumes when burned, and generates strong carcinogen dioxins, so it is prohibited to use in most industrial and civilian products

[0006] Sealants made of nitrogen-based flame retardants (such as melamine urate) have good flame-retardant properties, but they also need to be added in large quantities. There are problems of poor sealant elasticity and poor adhesion of sealants. At the same time, nitrogen-based Higher cost of flame retardants

[0007] Predecessors have conducted a series of studies on the application of phosphorus-based flame retardants in sealant formulations. Due to the poor miscibility between phosphorus-based flame retardants and organopolysiloxanes, they will precipitate from the sealant when preparing sealants, and stratification will occur. The problem is that the sealant is delaminated during storage and cannot be used or after the sealant is used, the flame retardant seeps out of the sealant surface and causes the surface of the sealant to become sticky and performance decline

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