Abstract: Bead-form expandable styrene polymers are obtained by suspension polymerization of styrene with addition of from 1 to 10% by weight of C.sub.3 - to C.sub.6 -hydrocarbons as blowing agents and, if desired, customary additives, where(a) the polymerization is initiated by rapidly heating the polymerization batch to form 80.degree. to 90.degree. C. within a maximum of 2 hours,(b) subsequently allowing the reaction temperature to increase to from 120.degree. C. to 130.degree. C. by from 8.degree. to 17.degree. C. per hour, and(c) the conversion is formed 30 to 60% when 100.degree. C. is reached, and(d) the conversion is 80% or more when the maximum temperature is reached, and(e) the batch is subsequently kept at from 100.degree. to 130.degree. C. until the residual monomer content in the polymer has dropped to less than 0.1%.

Abstract: A process for the preparation of styrene homopolymers or copolymers by suspension polymerization of monomers which contain dissolved styrene polymers from a preceding suspension polymerization, in the presence of sparingly soluble metal phosphates as suspension stabilizers, wherein, before the polymerization is started, the monomer phase is dispersed in an aqueous phase, containing a dissolved mineral acid, preferably phosphoric acid, at from 10.degree. to 80.degree. C. for from 5 to 120 minutes, after which the sparingly soluble metal phosphate is formed in situ in the aqueous phase. The process is particularly suitable for the preparation of expandable styrene polymers, in which case a volatile blowing agent is added to the suspension before, during or after polymerization.

Abstract: Styrene polymers are prepared by suspension polymerization using, as suspension stabilizers, mixtures of(A) a sparingly soluble inorganic metal compound and(B) a fine polymer dispersion.The styrene polymers may be used, together with blowing agents, for the manufacture of foams.

Abstract: Process for the manufacture of styrene polymers optionally containing blowing agent by polymerization in aqueous suspension using as the suspension stabilizer a calcium phosphate which after its manufacture by precipitation has been heated in aqueous dispersion for at least 2 hours at from 70.degree. to 130.degree. C. The styrene polymers may be used for the manufacture of foams.