Polylol for foamed plastic and polyisocyanurate foamed plastic adopting same

Abstract

The invention relates to a polyol for foamed plastic and polyisocyanurate foamed plastic adopting the same. A preparation method of the polyol for foamed plastic comprises the following step of: undergoing an etherifying reaction on highly-hydroxymethylated melamine and a unitary alcohol, wherein the hydroxymethylation degree of the highly-hydroxymethylated melamine is not less than 5.5; the unitary alcohol is one or a mixture of more than two of methanol, ethanol, propanol and butanol in any ratio; and the hydroxyl value of the polyol for the polyisocyanurate foamed plastic is 160-650 mg KOH / g. As an improvement, the preparation method of the polyol further comprises the following steps of: mixing an etherification reaction product with an alcohol-amine compound containing a -NH radical for undergoing a dehydrating reaction, and vacuumizing to remove water generated by the reaction; and adding excessive oxyalkylene hydrocarbon for undergoing a ring opening reaction. When the polyol for foamed plastic is taken as a raw material for preparing the polyisocyanurate foamed plastic, the flame resistance of the polyisocyanurate foamed plastic can be effectively improved.

Description

technical field [0001] The present invention relates to a polyol for foamed plastics and polyisocyanurate foamed plastics using the polyol. Background technique [0002] Rigid polyurethane foam is widely used in refrigerators, cold storage and water heater insulation due to its excellent thermal insulation properties. In the field of building insulation, due to the poor combustion performance of rigid polyurethane foam, it has not been widely used. Generally, three methods can be used to improve the flame retardancy of rigid polyurethane foam: (1) adding a certain amount of flame retardant to the reaction raw materials; (2) using excessive isocyanate to react to form polyisocyanurate foam; (3) ) to combine the above two methods. [0003] When using the first method, the flame retardant can be additive or reactive. Additive flame retardants, such as halogenated phosphates, chlorinated paraffins, aluminum hydroxide, etc., tend to greatly reduce the physical and mechanical p...

AI Technical Summary

Problems solved by technology

Additive flame retardants, such as halogenated phosphates, chlorinated paraffins, aluminum hydroxide, etc., tend to greatly reduce the physical and mechanical properties of the material, and as the addition time increases, the flame retardants in the material migrate and make the material The flame retardant performance of the reactive flame retardant is reduced; while the reactive flame retardant overcomes the above shortcomings, but there are disadvantages such as high cost and poor storage stability of the reaction raw materials.

In addition, excessive isocyanate can generate a large number of heterocyclic structures containing isocyanurate, which improves the flame retardancy of the foam material, but too much isocyanate will increase the fragility of the foam and reduce the fluidity of the foam, thereby reducing the foam and substrate. Cohesiveness, but also greatly reduces the formability of the foam

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