Patent ID: 11859066
Assignee: SYNTHOS S.A.
Field: Other special machines (Mechanical engineering)
Classification: CPC C  Y | IPC C

Claim 11:
12. Process for the preparation of the expandable polymer granulates of claim 1 comprising the following steps:
i) adding the styrene homopolymer or styrene copolymer to a reactor, and subsequently adding
i1) optional polymeric suspension aid,
i2) the mineral of the general formula ABX3, A and B being cations and X being anions, wherein the mineral has perovskite crystal structure, and the one or more athermanous additives,
i3) flame retardant,
i4) at least one peroxide as reaction initiator,
ii) adding demineralised water, and
ii1) at least one suspending agent which is an inorganic acid salt,
ii2) at least one peroxide as reaction initiator,
ii3) at least one suspension stabilizer selected from the group of anionic surface active compounds and/or high molecular weight compounds, and
iii) continuing the polymerization,
iv) adding the one or more blowing agents during or after the polymerization step,
v) cooling, and then separating the granulate from the water,
wherein the mineral having perovskite crystal structure and the one or more athermanous additives are introduced as athermanous additives in i2), and may also be introduced in step ii) and/or step iii).