A process for the preparation of a the thermoplastic elastomeric similar elastomer alloy with the use of old - or waste rubber

摘要

Elastomeric melt-mixed rubber compound, is made from recycled and scrap rubber crumb, by hot-mixing with polypropylene copolymers and radical donors. Polypropylene copolymer(s) or mixtures containing at least one type of polypropylene, are melted down in a mixer. Rubber crumb, some pre-soaked in a radical donor, is then dosed-in. Shearing deformation is increased, dispersing crumb into the plastic matrix. Plastic and crumb phases are coupled during this action, assisted by radical-forming agents, as a function of the mixing parameters. This dynamic stabilization process takes place above the melting point of the polypropylene copolymer (or its mixture), and below the decomposition temperature of crumb. Mixing time is sufficient for reaction of the radical-forming agent. Preferred Features: To increase hardness and strength of the compound, radical acceptors are added as a function of the half life of the radical donors, under mixing conditions. They are added before and/or during melt mixing. Regenerant addition precedes their incorporation. Rubber crumb is added in various gradings with receptor components. It is untreated, or is activated by mechanical and/or chemical-physical methods. Rubber crumb grading is about 1 mm. Before or during melt mixing, further additives e.g. filler, plasticizer, resin, new rubber and rubber mixtures are added, with compatibility agents.