Abstract: Photochemical conversion of tachysterols to previtamins is conducted in the presence of a polymeric photosensitizer which has the appropriate chromophore groups, e.g. anthracene groups, attached to a medium or high molecular weight, substantially uncrosslinked polymer backbone. The polymeric photosensitizer is soluble in solvents normally used for conducting the photochemical reaction (diethyl ether, dioxane, THF, t.butyl methyl ether) but insoluble in lower alcohols and hydrocarbons, so that it may be readily and simply recovered from the product mixture by use of such non-solvents.

Abstract: Radiation-curable two-layer systems containing immobilized photoinitiators are suitable for the production of coatings of constant thickness and good adhesion, and relief structures of high resolution and edge steepness.

Abstract: Disclosed is an easily-dyeable resin composition used in a sublimation type heat-sensitive transfer process. The composition comprises 100 parts by weight of a mixture composed of 40 to 95% by weight of a polyester resin and 5 to 60% of a crosslinking agent curable with active energy rays, and 0.01 to 12 parts by weight of a surface active agent selected from silicon-containing surface active agents and fluorine-containing surface active agents.

Abstract: An electrodepositable photosensitive resin which is a phenolic novolak resin having(i) at least part of the phenolic hydroxyl groups thereof replaced by a quinone diazide sulphonyloxy group, and(ii) at least part of the aromatic rings thereof substituted in a position ortho and/or para to a phenolic hydroxyl group or quinone diazide sulphonyloxy group by a group of formula --CH(R.sup.1)R.sup.2 whereR.sup.1 represents a hydrogen atom, or an alkyl, aryl or carboxylic acid group, andR.sup.2 represents a sulphonic acid group --SO.sub.3 H or a group of formula --A--R.sup.3 --X,R.sup.3 represents an aliphatic, aromatic or araliphatic divalent group which may be substituted by a carboxlic, sulphonic or phosphonic acid group,A represents a sulphur atom or a group of formula --N(R.sup.4)--, where R.sup.4 represents a hydrogen atom or an alkyl group which may be substituted by a carboxylic acid group or by an optionally etherified hydroxyl group, or R.sup.3 and R.sup.

Abstract: This invention describes the preparation of some new Mannich polymers and copolymers and teaches their general use as photosensitizers for onium salts for use in the initiation of free radical polymerization of vinyl monomers. These Mannich polymers are unexpectedly more efficient as photosensitizers than are the non-polymeric photosensitizers.

Abstract: Promoters for a crosslinking reaction involved in the curing of a system comprising crosslinkable polymers are bound to polymeric microparticles having a diameter of about 0.01 to 6 microns prepared by polymerizing a mixture of ethylenically unsaturated monomers. The microparticles carrying the crosslinking reaction promoter may be incorporated to coating compositions, printing inks, sealants, adhesives and other polymeric products in place of conventional crosslinking reaction promoters.

Abstract: An electrodepositable photosensitive modified phenolic novolak resin of general formula ##STR1## where Ar.sup.1 represents a divalent aromatic group linked through aromatic carbon atoms to the indicated groups --OR.sup.2 and --CH(R.sup.1)--,Ar.sup.2 represents a trivalent aromatic group linked through aromatic carbon atoms to the indicated groups --OR.sup.2 and --CH(R.sup.1)--,R.sup.1 represents a hydrogen atom or an alkyl, aryl or carboxyl group,R.sup.2 represents a hydrogen atom, an alkyl group which may be substituted by a hydroxyl or alkoxy group, or a group of formula --CO--R.sup.3 --COOH, --SO.sub.2 R.sup.4, --COR.sup.5 or --SO.sub.2 R.sup.5, at least 1% of the groups R.sup.2 representing a group --CO--R.sup.3 --COOH and at least 4% of the groups R.sup.2 representing a group --SO.sub.2 R.sup.4,R.sup.3 denotes a divalent aliphatic, cycloaliphatic, aromatic or araliphatic group,R.sup.4 denotes a 1,2-benzoquinone diazide group or 1,2-naphthoquinone diazide groupR.sup.

Abstract: Compositions of (a) a silicone resin characterized by an intermediate region free of acrylic groups, at least 150 siloxane units long, and terminal acrylic groups; (b) at least 10% of a fumed silica filler; and (c) a photoinitiator, can be cured by UV irradiation to tough elastomeric materials useful in adhesive and sealant applications.

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.

Abstract: Polyorganosiloxanes having an average of more than two siloxane repeat units, at least one of which repeat units includes a photoinitiating group bound to the silicon atom thereof, the photoinitiating group having the formula ##STR1## where R.sup.1 and R.sup.2 are the same or different alkyl groups or R.sup.1 and R.sup.2 are alkylene groups linked to each other so that R.sup.1 and R.sup.2 together with the carbon atom to which both are attached comprise a cycloalkyl group, and R.sup.3 is H or hydrocarbyl.Compositions of these polyorganosiloxanes and silicones or organic monomers with free radical curable groups are readily cured by irradiation with UV light.

Abstract: Coated material of a support, onto which is applied a radiation-sensitive coating of a homopolymer or copolymer with at least 5 mol %, based on the polymer, of structural units of the formula I ##STR1## in which R is a divalent aliphatic radical which can be interrupted by hetero-atoms or aromatic, heterocyclic or cycloaliphatic groups, a cycloaliphatic, heterocyclic or araliphatic radical, an aromatic radical in which two aryl nuclei are linked via an aliphatic group, or an aromatic radical which is substituted by at least one alkyl, cycloalkyl, alkoxy, alkoxyalkyl, alkylthio, alkylthioalkyl, hydroxyalkyl, hydroxyalkoxy, hydroxyalkylthio or aralkyl group or in which two adjacent C atoms of the aromatic radical are substituted by an alkylene group, R' independently has the same meaning as R and q is 0 or 1, and in which an aromatic radical R is not substituted by alkylene or by the abovementioned radicals if q is 0. The coating can be crosslinked directly by the effect of radiation.

Abstract: Novel polymeric photocleavable photoinitiators are prepared by the hydrosilation reaction of an organosilicon hydride grafting agent which has a photoinitiating aromatic-aliphatic ketone derivative of at least one organo group, with a polymer having a plurality of unsaturated olefinic or acetylenic sites in the presence of a hydrosilation catalyst. Preferred polymers are butadiene or alkyl substituted butadiene polymers and copolymers and vinyl functional polyorganosiloxanes. The grafting agents have the formula (hv)--R.sup.8 --R.sup.5 --H wherein (hv) is a photoinitiating aromatic-aliphatic ketone group, R.sup.8 is selected from alkylene, alkenylene, alkylenoxy and oxy groups, and R.sup.5 is selected from ##STR1## the R.sup.6 groups are the same or different organo or halo groups and n is an integer.