FIELD: chemistry.
SUBSTANCE: invention relates to a solid powdered composition containing unexpanded thermally expandable microspheres and an inhibitor, and is designed for use in compositions containing a polymer resin, its preparation, a method of preparing a similar composition and products made from the said composition. The composition contains expanded or unexpanded thermally expandable microspheres which are a thermoplastic polymer shell encapsulating a liquid propellant and from approximately 0.1 to approximately 50 wt % the number of microspheres of at least one inhibitor. The inhibitor is selected from a group consisting of acids having melting point lower than approximately 200°C and their precursors, where the said acid is not citric acid. The thermoplastic polymer shell is made from homo- and copolymers obtained from polymerisation of ethylene unsaturated monomers, and the liquid propellant has boiling point which is not higher than softening point of the thermoplastic polymer shell.
EFFECT: mixture of certain inhibitors with microspheres considerably reduces decolouration when using the composition as a blowing agent when making polymer materials at high temperature and/or long periods of processing.
24 cl, 5 tbl, 5 ex
