Ciba-Geigy Corporation

Ciba Specialty Chemicals Corporation

Leslie R Gatechair

Roland A Winter

Raymond R Seltzer

Peter J Schirmann

James L Hyun

Stephen D Pastor

Glen T Cunkle

Volker H Von Ahn

Matthew E Gande

Sheng-Shing Li

Raymond Stanley Kosiorek

Gary M Blumenstein

Ethylenically unsaturated carboxyl monomers, such as acrylic or methacrylic acid or their esters, are protected from premature polymerization during manufacture and storage in the presence or absence of water by the incorporation therein of an effective stabilizing amount of a blend two or more nitroxides. Some of these blends provide synergistic stabilization efficacy much superior to the stabilization results obtained by use of either nitroxide alone.

Polymerization inhibition of acrylates using blends of nitroxides

A process for stabilizing an ethylenically unsaturated monomer or oligomer from premature polymerization is disclosed whereby a stabilizing amount of an N-hydroxy substituted hindered amine is added to said polymerizable monomer or oligomer. The ethylenically unsaturated monomer or oligomer encompass vinyl monomers or oligomers bearing at least one polymerizable moiety. The N-hydroxy substituted hindered amine inhibits premature polymerization in the liquid and/or vapor phase.

Process for stabilizing ethylenically unsaturated compounds and

A process for stabilizing an ethylenically unsaturated monomer or oligomer from premature polymerization is disclosed whereby a stabilizing amount of an amine, preferably a substituted hindered amine, in combination with phenothiazine or other related heterocyclic moiety is added to said polymerizable monomer or oligomer. The ethylenically unsaturated monomer or oligomer encompass vinyl monomers or oligomers bearing at least one polymerizable moiety. The combination of substituted hindered amine plus phenothiazine inhibits premature polymerization in the liquid and/or vapor phase.

The polymerization of a vinyl aromatic compound, such as styrene, during distillation or purification is very effectively inhibited by the presence of at least one stable nitroxyl compound together with at least one aromatic nitro compound.

Inhibiting polymerization of vinyl aromatic monomers

A free radical polymerizable composition comprising a free radical polymerizable material and a photoinitiator system therefor comprising appropriate amounts of an alpha-cleavage or homolytic bond cleavage, photoinitiator and a ferrocenium salt, said composition being suitable for use in the preparation of protective layers and photographic images.

Ferrocenium/alpha-cleavage photoinitiator systems for free radical

Vehicles for ultraviolet radiation-curable ceramic enamels comprise (a) acrylate- or methacrylate-modified oligomers; (b) acrylate or methacrylate monomers, the functionality of (a) and (b) being selected to provide desired film and firing characteristics; (c) a combination of photoinitiators to provide a balance of surface and through cure; and an inhibitor to enhance shelf life. Printing media comprising pigmented frits and the vehicles are described, as are methods for their application to heat-resistant substrates, especially glass.

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Katonah, NY, United States of America

Leslie R Gatechair