Quick-curing polyisocyanate composition as well as preparation method and application thereof

Abstract

The invention discloses a quick-curing polyisocyanate composition as well as a preparation method and application thereof. The quick-curing polyisocyanate composition comprises isocyanurate formed by trimerization reaction of hexamethylene diisocyanate and hydrogenated xylylene diisocyanate, and the composition at least comprises two isocyanurate mononuclear bodies as shown in a formula in the invention. The polyisocyanate composition prepared by the invention has the characteristics of good quick-drying property, excellent mechanical property and the like, is simple in manufacturing process, and is particularly suitable for the fields with certain requirements on weather resistance and quick-drying property, such as the field of solar backboard laminated adhesives.

Description

technical field [0001] The invention relates to a polyisocyanate composition, in particular to a fast-curing polyisocyanate composition and its preparation method and application. Background technique [0002] The polyurethane coating film formed by the reaction of isocyanate curing agent and polyol has good wear resistance, toughness and easy processability, so it is widely used in various fields such as automotive coatings, home appliances, toys, and leather interior decoration. The coating film prepared by the traditional aromatic isocyanate series has a fast drying speed during the curing process, but with the prolongation of use time, the product is prone to yellowing or powdering to varying degrees. The aliphatic isocyanate series compositions obviously have more excellent yellowing resistance, and the products are more used in fields with high weather resistance requirements, but the reactivity of aliphatic isocyanates is low, resulting in products that often exist fo...

AI Technical Summary

Problems solved by technology

[0004] Patent CN103450443A provides an aromatic and aliphatic mixed isocyanate curing agent, which uses aromatic and aliphatic diisocyanate mixed and then isocyanurated, However, in this scheme, two kinds of raw materials are mixed and added at the same time, and an organic solvent needs to be added to reduce the viscosity of the system, and because the reaction speed of the aromatic isocyanate is much faster than that of the aliphatic isocyanate, a regular aromatic isocyanurate will be preferentially formed in the initial stage of the reaction , as the concentration of aromatic isocyanate decreases in the later stage of the reaction, aliphatic modified aromatic isocyanurate and a small amount of regular aliphatic isocyanurate will gradually form, which will lead to the activity of the final curing agent The isocyanate group is mainly aliphatic, so it has little effect on the quick-drying property, and because the aromatic itself has too much benzene ring content, and the product structure is more symmetrical, resulting in its weather resistance and operating viscosity. largely restricted

[0005] Patent CN103367489A provides a solution for solar backsheets, the isocyanate curing agent in the solution mainly refers to hexamethylene diisocyanate trimer or isophorone Diisocyanate trimer and hydrogenated modified aromatic diisocyanate monomer are applied in a physical mixing manner. The aromatic isocyanate monomer itself has poor quick-drying properties. On the other hand, due to the physical mixing method, at the molecular cross-linking structure level, the hydrogenated modified aromatic diisocyanate ring structure and the aliphatic isocyanate ring have no chemical bonds. , so it is difficult to achieve the ring-shaped synergy to produce a honeycomb network structure, and it is impossible to quickly form the strength support required for fast drying

Thirdly, the isocyanate monomer itself is highly volatile and harmful to the body and the environment. Its residues have been strictly limited in the latest standards published by the European Union.

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