Arkema France

Elf Atochem Italia S.r.l.

Atofina

Cray Valley Sa

Leo Mario Saija

Daniele Becchi

Mario Lugli

Ezio Montessoro

Carlo Sempio

Umberto Amadei

Isabelle Betremieux

Wenjun Wu

Stefano Finocchiaro

Luca Resta

Xiangling Meng

Hua Zhou

Simona Ferretti

Flippo Finetti

Baudouin Duque

Haiming Chen

Andrea Premoli

Filippo Finetti

The invention relates to aqueous polymer dispersions stable for at least 12 h, when dissolved in high amount of organic solvents and acidified at low pH (pH<2). The polymer comprises units and/or groups issued from: a) at least one (meth)acrylic monomer which is (meth)acrylic ester of a C1-C12 alcohol without any other functional group than (meth)acrylate, b) at least monomer b1) or initiator b2) or both as defined: b1) at least one vinylic, allylic or (meth)acrylic monomer, bearing an anionic group derived from strong acids with pKa<3, b2) at least one initiator, bearing the same anionic group as b1), c) at least one hydroxy-functional vinylic, allylic or (meth)acrylic monomer, and optional monomers, and which polymer bears: the anionic groups as defined in b) in an amount of at least 0.05 meq/g and hydroxy groups as defined in c) in an amount of at least 0.1 meq/g.

Stable aqueous polymer dispersions

The invention relates to aqueous polymer dispersions comprising polymerized units issued from the following monomers with related weight proportions based on 100 parts of weight of a)+b): a) 50 to 90% of a monoethylenically unsaturated non-ionic monomer, b) 10 to 50% of vinyl aromatic monomer or methyl methacrylate, c) 1 to 5% of a hydroxy-containing (meth)acrylate, d) 0.1 to 3% of acid monomer selected from d1) acid monomer selected from monocarboxylic or dicarboxylic acid monomers and d2) acid monomer selected from phosphorous-based or sulfur-based strong acid monomers or/and their salts, or from the mixtures of d1) and d2), e) 0.001 to 0.5% of chain transfer agent, and f) 0 to 1% one of internal crosslinker bearing at least two copolymerisable ethylenic unsaturations, the polymer having a Tg measured by DSC from −30 to 0° C. and a gel content of 0 to 60%, formed during polymerization.

Emulsion polymer compositions and use thereof in low odor waterproofing coatings

The invention relates to an aqueous polymer dispersion comprising:

Pressure sensitive compositions based on a modified rubber polymer aqueous dispersion

The invention relates to an aqueous polymer dispersion which can be obtained from a mixture of monomers comprising, in parts by weight: The invention also relates to a preparation process, to a coating composition comprising the said dispersion and to a method of use in coatings for metal or plastic substrates, in particular corrosion-inhibiting coatings for metal substrates.

Aqueous polymer dispersion for barrier coating

The process comprises the following phases: formation of a pre-emulsion of monomers in water; transfer into the polymerisation reactor with stirring, of (1) reaction stock consisting of a water solution of a surfactant, in an amount by weight relative to the weight of final polymer dispersion of 1&#x2013;15%; (2) a portion of the pre-emulsion prepared in the previous phase, in an amount of 1%&#x2013;10% by weight of the initial pre-emulsion; phase C.1: initiation of the polymerisation ; phase C.2: polymerisation of the monomer mixture at 30&#x2013;90&#xb0; C., by gradually adding into the reactor, separately, the initiator solution and the remaining portion of the pre-emulsion with an added salt, which is soluble in water at 25&#xb0; C. to at least 1% by weight, in an amount so as to have a salt concentration in the added pre-emulsion of 0.02&#x2013;0.25% by weight; phase C.3: scrubbing of the residual monomers.

Process for obtaining aqueous polymer dispersions

Aqueous polymer dispersions

Process for reducing the content of residual monomers, expressed as total VOC lower than 600 ppm and deriving from the monomers utilized to obtain the emulsion lower than 100 ppm; having an amount of wet coagula lower or equal to 500 ppm after wet filtering on 125 micron filter of the emulsion at the outlet after the various dropping phases, in polymrizations and copolymerizations in dispersion or emulsion in aqueous phase based on acrylic monomers, characterized in that it comprises as redox couple the utilization of a reducing agent selected from ascorbic acid or an aldehyde having a number of carbon atoms equal to or higher than 4 and containing at least a salifiable hydrogen, organic or inorganic, or its salts and the inorganic salifiable hydrogen being added to a carboxylic group; the aldehyde reducing agent or its salts being soluble in water for at least 5% by weight, preferably 10% by weight; and from an oxidizing agent consisting of an organic hydroperoxide in aqueous solution, excluding those soluble in H,O for more than 10% by weight, or its salts.

Low VOC emulsion

Process for reducing the content of residual monomers, expressed as total VOC lower than 600 ppm and deriving from the monomers utilized to obtain the emulsion lower than 100 ppm; having an amount of wet coagula lower or equal to 500 ppm after wet filtering on 125 micron filter of the emulsion at the outlet after the various dropping phases, in polymrizations and copolymerizations in dispersion or emulsion in aqueous phase based on acrylic monomers, characterized in that it comprises as redox couple the utilization of a reducing agent selected from ascorbic acid or an aldehyde having a number of carbon atoms equal to or higher than 4 and containing at least a salifiable hydrogen, organic or inorganic, or its salts and the inorganic salifiable hydrogen being added to a carboxylic group; the aldehyde reducing agent or its salts being soluble in water for at least 5% by weight, preferably 10% by weight; and from an oxidizing agent consisting of an organic hydroperoxide in aqueous solution, excluding those soluble in H.sub.2 O for more than 10% by weight, or its salts.

Process for reducing the content of residual monomers, expressed as total VOC lower than 600 ppm and deriving from the monomers utilized to obtain the emulsion lower than 100 ppm; having an amount of wet coagula lower or equal to 500 ppm after wet filtering on 125 micron filter of the emulsion at the outlet after the various dropping phases, in polymerizations and copolymerizations in dispersion or emulsion in aqueous phase based on acrylic monomers, characterized in that it comprises as redox couple the utilization of a reducing agent selected from ascorbic acid or an aldehyde having a number of carbon atoms equal to or higher than 4 and containing at least a salifiable hydrogen, organic or inorganic, or its salts and the inorganic salifiable hydrogen being added to a carboxylic group; the aldehyde reducing agent or its salts being soluble in water for at least 5% by weight, preferably 10% by weight; and from an oxidizing agent consisting of an organic hydroperoxide in aqueous solution, excluding those soluble in H.sub.2 O for more than 10% by weight, or its salts.

Growing community of inventors

Bagnolo in Piano, Italy

Leo Mario Saija