Polyurethane composite material for refrigeratory spray coating and preparation method thereof

Abstract

The invention relates to a polyurethane composite material for refrigeratory spray coating and a preparation method thereof. The composite material is composed of a component A and a component B in a weight ratio of 1:(1-1.05), wherein the component A is composed of polyether glycol, polyester polyol, crosslinking agent, foam stabilizer, foaming agent, catalyst, flame retardant and other assistants; and the component B is polymethylene polyphenyl polyisocyanate. The preparation method comprises the following steps: sequentially adding the components in the component A into a reaction kettle, and thoroughly mixing for 0.5-1.5 hours at normal temperature; and evenly mixing the component A and the component B in a weight ratio of 1:(1-1.05) with a high-pressure spray coater, atomizing, foaming, and quickly forming and aging the foam to obtain the product. The foam provided by the invention has the advantages of low heat conductivity coefficient, excellent low-temperature dimensional stability, high strength, excellent flame retardancy (the fireproofing grade reaches Grade B1), favorable binding property with the substrate, uniform density distribution and smooth surface, and is especially suitable for refrigeratory spray coating construction.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and in particular relates to a polyurethane composite material used for cold storage spraying and a preparation method thereof. Background technique [0002] At present, the cold storage insulation project mainly adopts two methods: composite sandwich panel assembly and rigid foam spraying. The sandwich panel assembly method has the advantages of convenience and quickness, but it will face many inconveniences in the construction process of small cold storage with various and irregular structures. The hard foam on-site spraying method is more and more used in cold storage insulation projects due to its flexible construction, no assembly gaps, excellent thermal insulation effect, and high bonding strength. [0003] However, most of the combined polyethers used in the preparation of polyurethane rigid foam spraying materials currently use 141b (monofluorodichloroethane) as a physical foaming agent...

AI Technical Summary

Problems solved by technology

[0003] However, most of the combined polyethers used in the preparation of polyurethane rigid foam spraying materials currently use 141b (monofluorodichloroethane) as a physical foaming agent. First, it is not environmentally friendly. High, not conducive to energy saving and consumption reduction

[0004] HFC-365mfc (1,1,1,3,3-pentafluorobutane) belongs to the third-generation blowing agent, with a boiling point of 40.2°C. It is the only liquid foam with a boiling point higher than room temperature among all zero-ODP HFC blowing agent products. Foaming agent, but the disadvantage is that it has certain flammability; HFC-134a (1,1,1,2-tetrafluoroethane), ODP=0, non-toxic, odorless, colorless, non-flammable, non-explosive, thermal stability Well, it has no plasticizing effect on polyurethane foam, but its disadvantage is that it has a low boiling point and is a gas at room temperature, so the original foaming equipment must be modified when it is used alone

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