Rhone-Poulenc Industries

Rhone-Poulenc Specialites Chimiques

Rhone-Poulenc Sante

A.e.c. Societe De Chimie Organique Et Biologique

Raymond Pigeon

Pierre Autant

Andre Cartillier

Robert E Sparks

Norbert S Mason

A composition which is stable in a medium in which the pH is greater than or equal to 5.5 and which permits the release of an active substance in a medium in which the pH is less than or equal to 3.5, comprising the active substance, which contains inclusions of, or which is completely or partially covered by, a pH sensitive material whose extent and/or rate of swelling is greater in an acidic medium than in a neutral medium, and a coating of a hydrophobic layer.

Composition for feeding ruminants

A composition for coating a biologically active substance which is stable in a medium in which the pH is greater than or equal to 5 and which permits the release of the active substance in a medium in which the pH is less than or equal to 3.5, comprises a film-forming, water-insoluble binder which possesses controlled hydrophilicity and is optionally slightly sensitive to pH variations, and a substance which is sensitive to pH variations (e.g. an inorganic filler, simple aminated substance, basic polymer or copolymer, chitosan). Pellets for feeding to ruminants consist of a core containing the biologically active substance, e.g. methionine or lysine, coated with this substance.

Compositions for coating feeding stuff additives intended for ruminants

An organopolysiloxane composition is facilely photocured, e.g., into a variety of non-stick coatings, by subjecting to a photocross-linking amount of ultraviolet irradiation, admixture of (i) a polysiloxane comprised of hydroxysilyl groups devoid of Si-H bonds and containing no organic radicals which include sites of activated ethylenic unsaturation, and (ii) an aminopolyalkoxysilane.

Photocuring of organopolysiloxanes devoid of Si-H bonds and containing

Photopolymerizable, liquid, storage stable organopolysiloxanes having viscosities of from 60 mPa.s to 2,000 mPa.s at 25.degree. C., are prepared by reacting (i) an .alpha.,.omega.-dihydroxydiorganopolysiloxane oil having a viscosity ranging from about 70 to 500 mPa.s at 25.degree. C., with (ii) a silane having the formula Z(G)SiR.sub.a (Q).sub.3-a wherein Z is CH.sub.2 .dbd.C(R')--COO-- or HS--, and further wherein the symbols R, which may be the same or different, are methyl, ethyl, n-propyl, vinyl or phenyl, R' is hydrogen or methyl, the symbols Q, which may be the same or different, are methoxy, ethoxy, n-propoxy, .beta.-methoxyethoxy and, when any two are taken together, the divalent radical --O--(CH.sub.3).sub.2 --C(CH.sub.3).sub.2 --O--, G is a linear or branched chain alkylene radical having from 1 to 8 carbons, and a is a number ranging from 0 to 2; and with the molar ratio of the hydroxyl functions comprising the oil (i) to the Q radicals comprising the silane (ii) ranging from 0.1 to 0.95. Such organopolysiloxanes are useful, e.g., release coating compositions.

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Francheville, France

Raymond Pigeon