Ciba Specialty Chemicals Corporation

Christian Schregenberger

Pascal Hayoz

Martin Kunz

Tyler A Stevenson

Roger Meuwly

André Fuchs

Rinaldo Hüsler

Michael Ackerman

John Francis Oswald

The invention relates to &#x3b1;-hydroxy ketones of formula I or IIa; or mixtures of compounds of formula I and II; or mixtures of compounds of formulae Ia and IIa 

Difunctional photoinitiators

A process for preparing 2-(2,4-dihydroxyphenyl)-4.6-diaryl-s-triazines in three steps starting with cyanuric chloride is described. Step,involves the nucleophilic (basic) displacement of one chlorine atom with a phenolic moiety. Step,involves a Friedel-Crafts reaction using a Lewis acid catalyst (preferably aluminum chloride) to replace the remaining two chlorine atoms with aryl groups such as xylyl. Finally, step,involves replacing the phenolic moiety with resorcinol using either a Lewis acid or protic acid catalyst or combinations thereof. Some additional processes only peripherally related to the three-step process outlined above are also described for the preparation of various s-triazine compounds. The s-triazines prepared are useful as UV absorbers for the stabilization of organic substrates against the adverse effects of actinic light.

Methods for the preparation of tris-aryl-o-hydroxyphenyl-s-triazines

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Olsberg, Switzerland

Christian Schregenberger