Abstract: The invention relates to aqueous disperse systems of photoinitiators which are particularly useful in the photopolymerization of aqueous disperse systems and emulsions of oligomers or polymers carrying photopolymerizable functionalities which are widely used in the field of dyes and packaging.

Abstract: The invention relates to the use of a new class of sulphurated derivatives of aromatic-aliphatic or aliphatic ketones as a) polymerization or crosslinking photoinitiators for transparent or pigmented mixtures containing ethylenically unsaturated photopolymerizable compounds, in particular for obtaining polyacrylates, b) photochemically releasable latent acid catalysts, useful for crosslinking systems polycondensable by acid catalysis, of the type comprising etherified aminoplasts together with compounds containing hydroxyl, carboxyl, amido, amino and other functionalities.Said sulphurated derivatives enable manufactured articles to be obtained with exceptionally clear color while maintaining photochemical reactivity at high levels.

Abstract: New carbonyl derivatives of 1-phenylindan suitable for use as photoinitiators in the photopolymerization of compounds or mixtures of compounds containing ethylenic double bonds.The carbonyl derivatives of 1-phenylindan according to the present invention possess high efficiency as photoinitiators in terms both of the concentration used and the photopolymerization rate.

Abstract: Modified galactomannans are described having a total molar substitution exceeding 0.7 and containing an average of between 0.7 and 4 hydrophilic substituents and between 0.0001 and 0.02 hydrophobic substituents per anhydroglycosidic unit, the molar ratio of hydrophilic to hydrophobic substituents being between 35:1 and 40,000:1.A process for their preparation is also described.When dissolved in water, the compounds of the invention have the property of modifying the rheological properties of aqueous solutions by increasing their viscosity and their suspending properties, thus making them particularly suitable for industrial use in the paint, paper, and ceramic production sectors and as printing aids in the textile field, as aids in the preparation of fluids used in hydrocarbon research and production, and generally in any application in which such properties are required.

Abstract: As initiators for the photopolymerisation of ethylenically unsaturated compounds, the use of systems consisting of compounds of benzophenone type of formula I ##STR1## in which R, R' and R.sup.2 are preferably alkyls of 1-4 carbon atoms, R.sup.3 and R.sup.4 are preferably hydrogen and Ar is preferably phenyl, in combination with donors of hydrogen or substances which determine the formation of labile photochemical complexes, such as alcohols, ethers and tertiary amines with hydrogen in the alpha position, and the use for the same purpose of mixtures of 2,4,6-trialkylbenzophenones and benzophenone and particularly of a mixture of 2,4,6-trimethylbenzophenone and benzophenone in a molar ratio of 1.155, which has the advantage of being liquid at temperatures exceeding 10.degree. C. and of possessing photochemical activity superior to that of benzophenone.

Abstract: A new class of polymeric or polymerizable aromatic-aliphatic ketones, the preferred of which are: 2-hydroxy-2-methyl(4-vinylpropiophenone), 2-hydroxy-2-methyl-p(1-methylvinyl)propiophenone, p-vinylbenzoylcyclohexanol, p-(1-methylvinyl)benzoyl-cyclohexanol and their oligomerization and polymerization products, they being suitable for use as photoinitiators for the photopolymerization of ethylenically unsaturated monomers and prepolymers.Said ketones are produced by subjecting an aromatic substrate, preferably a monomer or oligomer of styrene type, to the following reaction cycle: polymerization - acylation - alphachlorination - nucleophilic substitution with the formation of epoxyether - hydrolysis of the epoxyether; or to other reactions as modifications or alternatives to this cycle.The ketones according to the present invention have high efficiency as photoinitiators both with regard to the useful concentration to be used and with regard to the polymerization rate.