Soft polyurethane foam and manufacturing method therefor

Abstract

Provided is a durable, low-density soft polyurethane foam for use as a vehicle cushion or seat back, said soft polyurethane foam having strong mechanical properties. Also provided is a method for manufacturing said soft polyurethane foam. The provided soft polyurethane foam is manufactured by reacting and foaming a liquid mixture containing an organic polyisocyanate (A), a polyol (B), a chain extender (C), a catalyst (D), and a foaming agent (E). The core density of the provided soft polyurethane foam is between 25 kg/m and 35 kg/m . The aforementioned organic polyisocyanate (A) contains, by mass, 70 - 90% of a diphenylmethane diisocyanate (A-1) and 10 - 30% of a polymethylene polyphenylene polyisocyanate (A-2). Said diphenylmethane diisocyanate (A-1) contains 50 - 100% of 2,4-diphenylmethane diisocyanate and 2,2-diphenylmethane diisocyanate.

Description

technical field [0001] The present invention relates to a flexible polyurethane foam. More specifically, the present invention relates to a flexible polyurethane foam that can be suitably used for a vehicle seat back and a vehicle seat cushion. Background technique [0002] Hitherto, flexible polyurethane foams have been widely used not only for cushioning parts such as furniture, but also for car seats due to their excellent cushioning properties. [0003] As a method for producing a flexible polyurethane foam excellent in foam properties, moldability, and surface curability, specifically, for example, the use of a polyhydroxy compound, an organic polyisocyanate, a catalyst, a foam stabilizer, and a foaming agent (water) has been proposed. As a method of reacting with additives, the technique of using toluene diisocyanate as an isocyanate component is widely known as a flexible polyurethane foam (Patent Document 1). However, the freezing point of toluene diisocyanate under...

AI Technical Summary

Problems solved by technology

However, by modifying the isocyanate component with a polyol, the viscosity becomes higher and the NCO content becomes lower, so it is very difficult to obtain a flexible polyurethane foam with low density and high elastic properties, etc.

Also, there is no description of the concentration of chloride ions in the isocyanate composition

[0006] In previous inventions, when only diphenylmethane diisocyanate was used as the organic polyisocyanate component, it was difficult to form a low-density product used for a vehicle seat back, that is, a core density of 25-35kg / m 3 flexible polyurethane foam

That is, it is impossible to obtain a flexible polyurethane foam that satisfies the following properties: mechanical properties capable of withstanding the load of the process of covering the surface skin layer on the flexible polyurethane foam for vehicles, durability as a cushioning material, etc.

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