Non-pollution type polyurethane sealing material and preparation method thereof

Abstract

The invention discloses a non-pollution type polyurethane sealing material and a preparation method of the non-pollution type polyurethane sealing material, and belongs to the field of building materials. The polyurethane sealing material is formed by mixing a base and a curing agent; the base is formed by a prepolymer which is prepared by performing reaction on polyisocyanates and active hydroxyl compounds; and the curing agent comprises polyether, a catalyst, filler, a light stabilizer and a heat stabilizer. The preparation method of the base and the curing agent comprises the following step that the steps of dehydration, degasification, mixed grinding and the like are carried out in an airtight reactor provided with electric stirring, a thermometer and a vacuumizing function. According to the non-pollution type polyurethane sealing material and the preparation method, the strength, the deformation performance, the abrasion resistance, the chemical corrosion resistance, the high-low temperature resistance performance of the material can be guaranteed, and the surface pollution and deterioration of the material can be avoided; and therefore, the non-pollution type polyurethane sealing material is an ideal sealing material.

Description

technical field [0001] The invention relates to a novel polyurethane sealing material and a preparation method thereof, which will not cause aging and pollution due to changes in the internal composition of the material due to changes in the environment during long-term use, and belongs to the technical field of building materials. Background technique [0002] As we all know, the two-component polyurethane material refers to the prepolymer containing a certain isocyanate group mainly formed by the reaction of polyisocyanate and hydroxyl-containing polyester or polyether as the base agent (or main agent), composed of active hydroxyl compounds, fillers, Solvents, additives and catalysts are mixed into a paste as a curing agent (or hardener). After being fully mixed, an esterification reaction occurs to form a compound containing urethane bonds, urea bonds, substituted urea bonds, ether bonds and A cross-linked polymer with ester bonds, thus a sealing material that can be appl...

AI Technical Summary

Problems solved by technology

In this way, in the prepared sealing material, the common problem is: although the performance of the workability and the performance of the new sample tested according to the conventional indicators can meet the requirements, with the prolongation of the service life, the small Molecular weight solvents and additives will continue to migrate and precipitate, which not only causes the deterioration of the properties of the bulk material (such as the decrease of tensile strength and elastic recovery rate, the decrease of elongation at break, etc.), but also makes the surface of the sealing material absorb various dust, Surface pollution caused by impurities, etc., greatly affects the quality of building exterior decoration

For two-component reactive polyurethane sealing materials, it is difficult to achieve the corresponding anti-pollution effect only by changing the filler, but it is necessary to select each component and improve the preparation method

Japanese Patent Laid-Open 7-197011 (August 1, 1995) and Japanese Patent Laid-Open 10-17640 (January 20, 1998) adopt acrylic acid or substituted acrylic acid and polyol polyether esterification products to polymerize and then react with diisocyanate It is made into a prepolymer containing a certain amount of isocyanate groups. Since polyacrylate chain links are added to the polymer matrix, the aging resistance of the material is improved to a certain extent, but the esterification and polymerization reactions still need to be carried out in a solvent. At the same time, an initiator needs to be added, so there is still a certain amount of low-molecular compounds in the final cured body, and the pollution caused by the migration and precipitation of low-molecular compounds cannot be solved.