Elf Atochem S.a.

Atochem

Atofina

Elf Atomchem Italia S.r.l.

Christian Collette

Shu R Rebre

Andre Kowalik

Manuel Hidalgo

Jean-Marc Corpart

Emmanuel Puchois

Paul Mallo

Franco Marciandi

Roland Parsy

Daniel Augustin

Sandrine Denie

Denis Tembou Nzudie

Thierry Guerin

Jean-Michel Paul

Andre L Dessaint

Marie-Jose Lina

Francoise Candau

Martial Pabon

Elisabeth Schoch

Joseph Selb

Fabienne Lebendenko

Shu-Rong Rebre

The invention concerns a method for preparing water-soluble acrylic copolymers comprising the following steps: (i) preparing at least a monomer (1) of formula (I) wherein Ao is a &#x2014;(RtO)Rz or &#x2014;NRp (RtO)Rz group, by reacting a (meth)acrylic anhydride derivative (1') of formula (II) with a compound of formula AoH, Ao being as defined above; (ii) copolymerizing said monomer (1) with at least a monomer (2) of (meth)acrylic acid or of a derivative of said acid. The invention also concerns novel water-soluble acrylic copolymers and their use as superplasticizers or dispersants for hydraulic binders such as cements.

Method for preparing water-soluble acrylic copolymers

Certain mixtures of two superabsorbent powders having very different capillary suctions exhibit a resulting capillary suction which approaches the higher value. The resulting mixtures simultaneously exhibit a high capillary suction and a high intrinsic absorption capacity.

Superabsorbent powders of high absorption and high capillary suction

Water-in-water dispersions based on water-soluble polymers can be prepared using a polymer dispersant containing hydrophobic units. The dispersions of the invention are stable on storage and are of low viscosity.

Aqueous stable dispersions based on water-soluble polymers containing a cationic dispersant comprising hydrophobic units

The invention relates to aqueous saline dispersions containing a water-soluble polymer and a dispersant based on a polymer, preferably a cationic polymer, containing hydrophobic units.

Aqueous saline dispersions of water-soluble polymers containing an amphiphilic dispersant based on a cationic polymer containing hydrophobic units

Novel associative acrylic polymers prepared by radical inverse emulsion polymerization. It is a methacrylic ester in which the radical is composed of a hydrophilic segment and of a hydrophobic segment. The associative polymers of the invention can be used as thickeners, flocculating agents or filler-retaining agents.

Associative polymers containing 2,4,6-triphenethyl benzyl

Acrylic copolymers containing the following repeating units: ##STR1## wherein R.sub.A, R.sub.B, R.sub.C, R.sub.I, R.sub.II, equal or different, are H or CH.sub.3 ; M.sup.+ is H or a cation belonging to group IA, IIA, or ammonium; n is an integer from 0 to 2; A.sub.0 is --COO--(R.sub.T O).sub.m --R.sub.Z wherein R.sub.T is a saturated C.sub.2 -C.sub.4 alkyl group, m is an integer from 7 to 50, R.sub.Z is H or a saturated C.sub.1 -C.sub.4 alkyl group; R.sub.III is H, COOH, COO.sup.- M.sup.+ wherein M.sup.+ is as above defined or A.sub.0 as above defined; and optionally containing a third comonomer in a quantity 0-20% of the total monomer weight, said polymers, that contain in terminal position silanol groups, are obtainable by copolymerizing the monomers in the presence of the following chain transfer agents:

Hydrosoluble acrylic copolymers

Rapidly dissolving/absorbing free-flowing powders of hydrophilic/superabsorbent (co)polymers, having irregular nonspherical morphology and a particle size distribution ranging from 100 .mu.m to 800 .mu.m, are prepared by (a) phase inversion (co)polymerizing stirred admixture of (i) a hydrocarbonic solution of at least one surfactant having an HBL ranging from 8 to 12 and (ii) an aqueous solution of at least one hydrophilic unsaturated monomer, in the presence of an effective amount of a radical polymerization initiator and at a predetermined temperature of (co)polymerization, (b) next introducing into the medium of (co)polymerization, after (co)polymerization of the at least one hydrophilic unsaturated monomer, a second aqueous solution of at least one hydrophilic unsaturated monomer, (c) then (co)polymerizing the second aqueous solution, and (d) thence extracting the hydrocarbonic phase and water from the resulting (co)polymerizate and drying same, with the proviso (e) that the second aqueous monomer solution is introduced at a temperature of about the predetermined temperature of (co)polymerization and the volumetric ratio of aqueous phase to hydrocarbonic phase ranges from 0.6 to 1.2.

Preparation of rapidly dissolving/absorbing powders of hydrophilic/super

Shell/core distortion-resistant particulates of a partially crosslinked superabsorbent polymer, the gradient of partial crosslinking of which being to such extent that the shells are harder and less flexible than the cores thereof, have a capacity to absorb 0.9% saline water of at least 50 g/g and the modulus of which is at least 35,000 Pa; a bed of a saline water gel of the subject particulates has a saline water absorption of at least 20 g/g and a porosity of at least 500 g.

Shell/core particulates of superabsorbent polymers

The process consists in the agglomeration of fine particles of superabsorbent polymer, carried out by introducing an aqueous solution of monomer into a slurry of aqueous polymer dispersed within a hydrocarbon liquid, this introduction being performed directly at the temperature and in conditions of polymerization of the monomer. A superabsorbent product is thus obtained in a very good yield, in the form of aggregates of particles such that the fraction passing through a 100-micron screen is less than 1%.

Process for obtaining polymers which are superabsorbent for water and

Superabsorbent, high gel strength/short gel time acrylic polymers, well suited for the production of items of feminine hygiene/adult incontinence, are prepared by (a) inversely suspending an aqueous acrylic monomer phase in an organic solvent in the presence of an emulsifying agent having an HLB of from 8 to 12, the aqueous monomer phase also comprising a crosslinking agent therefor, (b) polymerizing the inverse suspension of acrylic monomer into a polymer gel, (c) absorbing a second charge of acrylic monomer into the polymer gel thus attained, the ratio of the amount of the second monomer charge to the amount of monomer in the beginning aqueous phase ranging from 1 to 1.2, (d) introducing a surfactant having an HLB of from 2 to 5 into the medium of polymerization, and (e) polymerizing the second monomer charge within the polymer gel.

Superabsorbent polymers

Particulates of a superabsorbent partially, neutralized acrylic polymer, e.g., polyacrylic acid, having a mean particle size ranging from 100 to 500 .mu.m, essentially monodisperse and essentially devoid of fines having a particle size of less than 100 .mu.m, having a nonuniformly surfaced spheroidal particle morphology and containing less than 50 ppm of residual monomer, well suited for a variety of hygienic applications, are prepared by (i) polymerizing a suspension of an acrylic monomer charge I in an organic medium and producing a suspension of acrylic polymer gel particles, (ii) next absorbing a second acrylic monomer charge II into the gel particles, (iii) polymerizing in the gel particles the second acrylic monomer charge II, (iv) azeotropically dehydrating the acrylic polymer particulates thus obtained, (v) then treating the dehydrated particulates with hydrogen peroxide, and (vi) drying the superabsorbent particulates thus treated.

Superabsorbent acrylic powders having low residual monomer content

Fluorine-containing copolymers for use in coating substrates or for incorporation thereinto in order to impart water- and oil-repellent properties thereto are provided, starting from the following monomers:

Fluorine-containing copolymers and their use for coating and

Particulates of a superabsorbent partially, neutralized acrylic polymer, e.g., polyacrylic acid, having a mean particle size ranging from 100 to 500 .mu.m, essentially monodisperse and essentially devoid of fines having a particle size of less than 100 .mu.m, having a nonuniformly surfaced spheroidal particle morphology and well suited for a variety of hygienic applications, are prepared by (i) polymerizing a suspension of an acrylic monomer charge I in an organic medium and producing a suspension of acrylic polymer gel particles, such acrylic monomer charge I having a degree of neutralization greater than that desired in the final superabsorbent polymer, (ii) next absorbing a second acrylic monomer charge II into the gel particles, such acrylic monomer charge II having a degree of neutralization less than that desired in the final superabsorbent polymer, and (iii) polymerizing in the gel particles the second acrylic monomer charge II.

Superabsorbent acrylic powders

Particulates of a superabsorbent polymer, e.g., an acrylic polymer such as polyacrylic acid, well suited for a variety of hygienic applications, are prepared by (i) suspending an aqueous solution of a water-soluble monomer charge I in a hydrocarbon medium by means of a polymerizable surfactant having the general formula:

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Paris, France

Christian Collette