Inorganic-organic highly environment-friendly two-component adhesive and preparation method thereof

Abstract

The main objective of the invention is to provide an inorganic-organic highly environment-friendly two-component adhesive which is friendly to environment, good in bonding strength, wettability, fire resistance and weatherability, stable in performance, easy to coat and small in shrinkage after curing and also has foaming performance. The adhesive is composed of a component A including water glass and / or water glass or an aqueous polyvinyl alcohol solution and a component B composed of a mixture of polyurethane and polyisocyanate. The adhesive is characterized in that the component A contains a filler, and a weight ratio of the filler to water and / or water glass is 3-30: 10; and the content of an organic solvent in the component B is 0 to 10%. The adhesive provided by the invention is free of any solvent or low in solvent content, so the adhesive is environment-friendly and is safer to produce and use; the adhesive is easy to apply and promote due to the advantages of good workability, uniformity, coatability, flame retardancy, corrosion inhibition performance, adhesiveness, economic performance and environmental protection performance; and the adhesive is friendlier to environment and cheaper compared with ordinary polystyrene foam has the excellent properties like flame retardancy, quick-drying and high strength, so the adhesive is expected to totally replace polystyrene foam in the door industry.

Description

Technical field [0001] The present invention relates to a solvent-free or low-solvent two-component polyurethane adhesive, especially the water-based component contains water and / or water glass and fillers, and the polyurethane component contains polyisocyanate and prepolymer, which can be used for metal, stone and wood Two-component polyurethane adhesive for bonding between non-metallic materials. Background technique [0002] As an inorganic compound, water glass has many excellent properties such as high temperature resistance, flame retardancy, low cost, and environmental protection. Polyisocyanate and polyurethane prepolymer contain isocyanate (-NCO) and urethane groups (- NH-COO-), therefore, polyurethane adhesives exhibit high activity and polarity, and are compatible with substrates containing active hydrogen, such as foam, plastic, wood, leather, fabric, paper, ceramics and other porous materials, as well as metal, glass, rubber , Plastics and other materials with smoot...

AI Technical Summary

Problems solved by technology

From the substantive technical characteristics of the invention, it can be seen that under certain composition and proportioning of water glass components, adding solvent in the polyisocyanate and prepolymer mixture components can significantly improve the bonding performance of the sizing material and increase the bond strength, However, the increase of organic solvent will reduce the environmental performance of the rubber compound, and when there are more fillers in component A, the two-component mixing and stirring will often cause problems that are not easy to fuse or even phase separation, which will cause local aggregation of the mixed rubber compound, forming Uneven particles and incompatible liquids affect the uniformity, stability, and wettability of the rubber, resulting in uneven coating or even difficulty in coating during sizing, which seriously affects the adhesive performance of the adhesive.

In addition, although water glass can endow the rubber with excellent flame retardancy, corrosion inhibition and antirust performance, it is strongly alkaline and can absorb carbon dioxide produced by the reaction of polyisocyanate or prepolymer NCO with water, making the glue cured It seems that the foaming is not obvious, at best it is slightly foaming, and the core of the fire door is mostly magnesium oxychloride or perlite blocks, with uneven surface, and the foaming amount of the rubber is usually required to be not less than 2.5 times. European patent EP03010871 .9 claims that adding 1-20% water to the water glass component can produce foaming, and adding more than 40% water results in a more brittle adhesive layer

The test shows that adding less than 20% water to the water glass component is difficult to achieve 2.5 times the foaming amount, and the brittleness is high and the practicality is poor. However, if the content of water or solvent is increased, the glue is easy to collapse after foaming, and the brittleness is very high. Large, poor bond strength and mechanical strength