Ciba-geigy Corporation

Ciba Specialty Chemicals Corporation

E.i. Dupont De Nemours and Company

Vincent Desobry

Kurt Dietliker

Manfred Rembold

Werner Rutsch

Rinaldo Husler

Franciszek Sitek

Hans O Doggweiler

Eginhard Steiner

Martin Riediker

Harry Beyeler

Rinaldo H Usler

Peter Murer

Charles T Berge

Anne Schuwey

Thermal- and photoinitiated radical polymerization in the presence of an addition fragmentation agent

Synthesis of linear acrylic polymers and copolymers having controlled molecular weight by the photoinitiated free radical polymerization of vinyl monomers in the presence of chain transfer agents to produce polymers useful in coating compositions and the like, including printing inks.

Molecular weight controlled polymers by photopolymerization

A Process for the selective preparation acrylate- or methacrylate-homo- or acrylate- or methacrylate-co-oligomers with a weight average molecular weight (Mw) from 1000 to 20000, a polydispersity&lE;3 and a conversion of the monomers to polymers greater than or equal to 70%, or for the selective preparation of polyvinylacetate and its hydrolysis product polyvinylalcohol with a weight average molecular weight (Mw) from 1000 to 25000, a polydispersity&lE;3 and a conversion of the monomers to polymers greater than or equal to 70%, is characterized in that a mixture of the corresponding monomers is irradiated in the presence of a specific photoinitiator or photoinitiator mixture at a temperature from &minus;20 to 70&deg; C. in an inert solvent or inert solvent mixture, with light of a wavelength from 305 to 450 nm, wherein the contents of monomers in the reaction mixture is up to 70%.

(Co)polymers by photopolymerization

Compounds of the formula I, II, III and IIIa ##STR1## in which Ar.sup.1 is an unsubstituted or substituted aromatic radical and at least one of the radicals R.sup.1 and R.sup.2 is an alkenyl, cycloalkenyl or arylmethyl group, are effective photoinitiators for photopolymerization of unsaturated compounds. They are particularly suitable for photocuring of pigmented systems.

A-aminoacetophenones as photoinitiators

.alpha.-aminoacetophenones as photoinitiators

Fluorine-free titanocene compounds of the formula I or II ##STR1## in which both R.sub.1 radicals are preferably, independently of one another, cyclopentadienyl.sup..crclbar., which is unsubstituted or substituted by alkyl,alkoxy or --Si(R.sub.2).sub.3, and both R.sub.2 radicals are, in particular, alkyl, ##STR2## Z is --NR.sub.10 --, --0-- or --S--, Y is Cl, Br, I, CN, SCN, --O--CO--CH.sub.3, --O--CO--phenyl or --O--SO.sub.2 --CH.sub.3,

Fluorine-free titanocenes and the use thereof

Titanocenes of the formula I ##STR1## in which R.sup.1 are cyclopentadienyl.sup..crclbar. groups and R.sup.2 and R.sup.3 are aromatic radicals which are substituted in both ortho-positions by fluorine and, in addition, are substituted by an acyloxy group are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds.

Oxygen-containing titanocenes, and the use thereof

There is disclosed a process for the preparation of compounds of formula I

Process for the preparation of organometallic compounds

Novel alpha-aminoacetophenones as photoinitiators

An improved preparation of titanocenes of the formula I ##STR1## in which R.sub.1 is cyclopentadienyl.sup..crclbar., indenyl.sup..crclbar. or 4,5,6,7-tetrahydroindenyl.sup..crclbar., each of which is unsubstituted or monosubstituted or polysubstituted by C.sub.1 -C.sub.18 alkyl, C.sub.1 -C.sub.18 alkoxy, C.sub.2 -C.sub.18 alkenyl, C.sub.5 -C.sub.8 cycloalkyl, C.sub.6 -C.sub.10 aryl, C.sub.7 -C.sub.16 aralkyl, --Si(R.sub.3).sub.4, --Ge(R.sub.3).sub.4 or halogen, or the two R.sub.1 radicals together are a divalent radical of the formula II ##STR2## in which Z is --(CH.sub.2).sub.m -- where m=1, 2 or 3, unsubstituted or phenyl-substituted C.sub.2 -C.sub.12 alkylidene, --Si(R.sub.3).sub.2 -- or --Si(R.sub.3).sub.2 --O--Si(R.sub.3).sub.2 --, and R.sub.3 is C.sub.1 -C.sub.12 alkyl or C.sub.6 -C.sub.10 aryl, and R.sub.2 is six-membered carbocyclic aromatic ring which is substituted by fluorine in both the ortho-positions to the Ti-C bond and which may also have further substituents, involves the addition of certain lithium amides to a mixture of (R.sub.1).sub.2 TiX.sub.2 (X=halogen) and HR.sub.2 at -30.degree. C. to +25.degree. C.

Process for the preparation of titanocenes containing O,O'-difluoroaryl

A process is described for preparing compounds of the formula I

Growing community of inventors

Marly, Switzerland

Vincent Desobry