Muanyagipari Kutato Intezet

Finomvegyszer Szovetkezet

Istvan Kovacsay

Laszlo Magdanyi

Geza Kecskemethy

Ferenc Szailer

Ede Szatmari

Istvan Dubovszky

Maria Szajko Nee Lorinczi

The invention is a process for monitored cross-linking of unsaturated polyester resins in the presence of a metal-ion-containing accelerator and an organic peroxide initiator, complemented by promotor in some cases. According to this process, the cross-linking is carried out in the presence of one of the compounds from the group consisting of alizarin, sodium alizarinesulfonate, 3-nitroalizarin, chinizarine, or purpurin, where the substituents are H atoms or OH, NO.sub.2, SO.sub.3 H, or SO.sub.3 Na groups with the restriction that at least one of them should be other than H, which is present in a ratio of from 0.005 to 0.5, preferably 0.01 to 0.1 percent (mass/mass), compared to the mass of the polyester resin, and cross-linking is trailed by the color change in the system. The invention permits all of the chemical-technological processes involved in the processing of unsaturated polyester resins to be monitored visually.

Procedure for curing unsaturated polyester resins

The invention relates to a process for the controlled hardening of unsaturated polyester resins at temperatures of -5.degree. C. to +150.degree. C. using an organic peroxide initiator. According to the process of the invention an organic dyestuff of the general formula (I), ##STR1## wherein R.sup.1 stands for a group of the general formula (II), ##STR2## and in this formula R.sup.5 is a C.sub.1-4 alkyl group and n is an integer from 1 to 3,

Process for the controlled hardening of unsaturated polyester resins

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Budapest, Hungary

Istvan Kovacsay