Preparation method of reactive sealant resin

Abstract

The invention discloses a preparation method of reactive sealant resin, which comprises the following steps: (1) polymerizing a hydroxyl-containing initiator with an epoxy compound under the action ofan alkali catalyst to obtain polyether polyol; (2) adding an alkoxide reagent and a halogenated end-capping reagent containing double bonds into the polyether polyol obtained in the step (1) to reactso as to obtain a double-bond end-capped polyether crude product, and refining the obtained crude product so as to obtain a modified polyether product; and (3) carrying out silane end-capping reaction on the modified polyether and hydrogen-containing silane under the action of a hydrosilylation catalyst to obtain the target product reactive sealant resin. The resin is excellent in property, and has good adhesion and finishing property.

Description

technical field [0001] The invention relates to the field of sealants, in particular to a method for preparing a reactive sealant resin, which is mainly used for preparing elastic sealants. Background technique [0002] Since the 1980s, with the modernization of urban buildings and the improvement of building function requirements, there are more and more varieties and quantities of high-performance sealants used for sealing joints in building structures in my country. The earliest used in buildings is the polysulfide type. Acrylic, silicone and polyurethane sealants have been developed successively, and the development is very rapid. Among them, the silicone type sealant has the fastest development, which has the advantages of fast curing speed, high temperature resistance and weather resistance, but has the disadvantages of low strength and unpaintable surface. Polyurethane sealants have high strength, good oil and solvent resistance, and good abrasion resistance, but they...

AI Technical Summary

Problems solved by technology

[0006] 2. Synthesize a high molecular weight polyether with a double bond at one end and a hydroxyl group at one end, and then multiply it with a coupling agent (such as diisocyanate, etc.) to a modified polyether with a higher molecular weight, and then make a terminal siloxane through the end-capping process Based polyether, the molecular weight of the polyether used is relatively high, and the urethane group contained in the molecular chain is small, and a coupling reaction can be carried out by the coupling agent, which has little effect on the viscosity of the polymer, and there is no by-product of the coupling reaction , the process operation is relatively simple, but there are coupling agent residues in the product, and the weather resistance deviation

[0007] 3. Use the Williamson ether synthesis method to react the hydroxyl-terminated polyether with lower molecular weight with alkali metal or alkali metal hydroxide, couple with dichloromethane to double its molecular weight, and then react with allyl chloride to form a double-bonded polyether , through silicon-oxygen addition reaction to produce terminal siloxane-based polyether, but the molecular weight distribution of the chain extension product with dichloromethane is relatively wide, which directly affects the performance of sealants, and can only be used to prepare bifunctional resins

[0008] 4. Using bimetallic catalysts to synthesize high-molecular-weight hydroxyl-terminated polyethers, and then modify the polyethers to make siloxane-terminated polyethers through hydrosilicon addition, but the removal of by-product salts in the process is a difficult point. There is no reasonable solution yet