Polyurethane combined polyether for refrigerator and polyurethane hard foam thereof

Abstract

The invention relates to polyurethane combined polyether for a refrigerator and polyurethane hard foam thereof for the refrigerator. The polyurethane combined polyether for the refrigerator is prepared from the following components: 1.5 to 3 parts of surfactant, 1.0 to 2.4 parts of chemical foaming agent, 15 to 22 parts of physical foaming agent, 100 parts of polyether glycol and a conventional consumption amount of catalysts, wherein the polyether glycol is prepared from 40 to 60 weight percent of polyether glycol A, 20 to 40 weight percent of polyether glycol B, and 10 to 20 weight percent of polyether glycol C; and the polyurethane combined polyether and polymethylene polyphenyl polyisocyanates are uniformly mixed in a weight ratio of (1 to 1.05) to (1 to 1.3) and foamed to prepare the polyurethane hard foam. The polyurethane combined polyether and the polyurethane hard foam are mainly used for producing a heat preserving layer of the refrigerator and freezers and have the advantages of low heat conduction coefficient, less consumption, high production efficiency, fewer suction pit defects of a refrigerator liner and the like.

Description

technical field [0001] The invention belongs to the field of environment-friendly polyurethane energy-saving materials, in particular to a combination of polyurethane polyether and polyurethane rigid foam for refrigerators. Background technique [0002] Since the signing of the "Montreal Protocol", the replacement technology of ozone-depleting substances (ODS) has been developing rapidly in the world. In my country's rigid polyurethane foam industry, both HCFC-141b and pentane foaming systems are used. After all, HCFC-141b is a transitional substitute and will be completely replaced in the rigid polyurethane foam industry in 2025. The applicant pays attention to product research and development, and its team members successfully completed the conversion of blowing agents with zero ODP value by adopting the replacement technology of blowing agents with zero ODP value (especially HFC-245fa and cyclopentane). [0003] Polyurethane rigid foam is widely used at home and abroad ...

AI Technical Summary

Problems solved by technology

For the rigid foam used in refrigerators and freezers, due to its special performance requirements, many current products have shortcomings such as many surface defects, high thermal conductivity, uneven density distribution, large amount of raw materials required, and long demoulding time.

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