A kind of mixing type polyurethane foam material and preparation method thereof

Abstract

The invention provides a preparation method of a mixed polyurethane foam material, which comprises the following steps: (1) uniformly mixing a vulcanizing agent and an alkaline filler to obtain a mixture, plastifying polyurethane unvulcanized rubber, mixing the mixture and the plastified polyurethane unvulcanized rubber, vulcanizing the mixing product at 115-120 DEG C for 5-30 minutes, and vulcanizing at 125-135 DEG C for 3-15 minutes to obtain a prevulcanizing product; (2) putting the prevulcanizing product in a high-pressure reaction kettle, introducing CO2, increasing the temperature and pressure to convert CO2 into supercritical CO2, and reducing the pressure in the high-pressure reaction kettle to normal pressure by a quick pressure reduction process when the supercritical CO2 reaches the saturated state in the prevulcanizing product; and (3) vulcanizing the mixed polyurethane prevulcanized foamed material at 140-170 DEG C for 0.5-1 hour, and vulcanizing at 180-220 DEG C for 1.5-3 hours. The method has favorable controllability on foam pore distribution and foam pore size; and the foam pores are uniformly distributed in the polyurethane foam material.

Description

technical field [0001] The invention belongs to the field of polyurethane foam materials, in particular to a mixing type polyurethane foam material and a preparation method thereof. Background technique [0002] Polyurethane microcellular elastomer not only has the elasticity and flexural properties of polyurethane elastomers, but also has the characteristics of porous materials. It has the characteristics of light weight, good wear resistance, and excellent shock absorption performance. Sole materials, etc. From the point of view of the manufacturing process, the existing polyurethane microcellular elastomers include thermoplastic polyurethane microcellular elastomers and cast polyurethane microcellular elastomers. The high elasticity of thermoplastic polyurethane microcellular elastomers is produced by relying on the crystal structure formed by the hard segment to act as a physical cross-linking point. Viscous flow may occur between the molecular chains of the material, r...

AI Technical Summary

Problems solved by technology

[0003] For castable polyurethane microcellular elastomers, the preparation method is to mix the reaction raw materials isocyanate, polymer polyol, catalyst, chain extender, coupling agent, foaming agent, etc., and pour them into the mold for reaction and foaming. In the preparation process, foaming and chain growth or cross-linking reactions are simultaneously carried out in the reaction system, which causes the nucleation and growth of cells to be disturbed by complex chemical reaction processes, and the controllability of the foaming process Not good, it is prone to problems of uneven cell distribution and difficult control of cell size

Especially when water is used as the blowing agent, the reaction between water and isocyanate is violent, and a large amount of reaction heat is released, and the generated CO 2 It has little effect on reducing the viscosity of the polyol complex solution, which is not conducive to the diffusion of reaction heat in the reaction system, resulting in uneven distribution of reaction heat, resulting in burnt yellowing of the inside of the polyurethane foam material, uneven distribution of cells and local cells. broken problem

Uneven cell distribution or excessive cell size range will easily lead to large differences in the impact resistance of different parts of the polyurethane microcellular elastomer, and there may be defective areas of impact resistance. Therefore, it is necessary to develop a cell distribution and Preparation method of polyurethane microcellular elastomer with better cell size controllability

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