Ciba-geigy Corporation

Ciba Specialty Chemicals Corporation

Nalco/exxon Energy Chemicals,l.p.

Volker H Von Ahn

Roland A Winter

Ramanathan Ravichandran

Mark S Holt

Tyler A Stevenson

Peter Nesvadba

David G Leppard

Samuel Evans

Joseph E Babiarz

Matthew E Gande

Glen T Cunkle

Thomas Friend Thompson

Leslie R Gatechair

Roland A E Winter

Sheng-Shing Li

1,2-Bis-adducts of stable hindered nitroxide compounds with substituted ethylenes are prepared by reacting two equivalents of nitroxyl compound with an ethylenically unsaturated compound such as styrene or an acrylate ester. These adducts are very effective inhibitors to prevent the premature polymerization of ethylenically unsaturated monomers when such monomers are distilled, processed or stored.

1,2-bis-adducts of stable nitroxides with substituted ethylenes and stabilized compositions

When a nitroxyl compound is heated in an oxygen-free atmosphere with a vinyl aromatic monomer at 50-140.degree. C. for up to 60 days, it forms an activated inhibitor mixture which is superior to the nitroxyl compound itself in preventing the premature polymerization of a vinyl aromatic monomer during its processing and purification.

Inhibiting polymerization of vinyl aromatic monomers

2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.

Process for making 5-thio-substituted benzotriazole UV absorbers

1,2-Bis-adducts of stable nitroxides with substituted ethylenes and

Ethylenically unsaturated monomers are protected from premature polymerization during manufacture and storage by the incorporation therein of an effective stabilizing amount of a 7-substituted quinone methide compound.

7-substituted quinone methides as inhibitors for unsaturated monomers

Ethylenically unsaturated monomers are protected from premature polymerization during manufacture and storage by the incorporation therein of an effective stabilizing amount of a 7-aryl quinone methide compound.

Inhibition of unsaturated monomers with 7-aryl quinone methides

Soluble and thermally stable benzotriazole UV absorbers typified by those of formula I ##STR1## where R.sub.1 is hydrogen or chloro, R.sub.2 is alkyl or --CH.sub.2 CH.sub.2 COOR.sub.4 where R.sub.4 is hydrogen, alkyl or alkyl substituted with hydroxyl, and R.sub.3 is .alpha.-cumyl, provide excellent light stability protection to electro coat, base coat or clear coat finishes. The new soluble, crystalline form of 2-(2-hydroxy-3-.alpha.-cumyl-5-tert-octylphenyl)-2H-benzotriazole is particularly effective.

2-(2-hydroxy-3-.alpha. cumyl-5-tert nonyl or dodecyl phenyl)-2H-

Crystalline form of

Electro coat/base coat/clear coat finishes stabilized with soluble and

2-(2-hydroxy-3-.alpha.-cumyl-5-nonylor 5-dodecylphenyl)-2H-benzotriazole

Nitroxyl inhibitors in combination with some oxygen reduce the premature polymerization of vinyl aromatic monomers during the manufacturing processes for such monomers. Even small quantities of air used in combination with the nitroxyl inhibitors result in vastly prolonged inhibition times for said monomers.

Method for inhibiting premature polymerization of vinyl aromatic monomers

Compositions stabilized with 5-thio-substituted benzotriazole

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Mahopac, NY, United States of America

Volker H Von Ahn