Abstract: The present invention relates to an aqueous emulsion comprising: a) from 50% to 60% of an organic phase dispersed in an aqueous phase, said organic phase containing a mixture including from 24% to 30%, calculated with respect to the final emulsion, of ethylene-vinyl acetate copolymers and/or polyalkyl(meth)acrylates, indicated in the present description as polymeric component, and a high-boiling organic solvent, or a mixture of said solvents; b) a primary emulsifier at a concentration higher or equal to 0.1% and lower than or equal to 3% by weight, calculated with respect to the final emulsion; c) from 37% to 47% of an aqueous phase; wherein the ratio between said polymer component and said organic solvent in the final aqueous emulsion is at least 1/1 and where the organic solvent and any polymer of the polymeric component have a Hildebrand solubility parameter ? such that, the difference (?solvent_?polymer) is lower than 2 in absolute value for any polymer of the polymeric component.

Abstract: The present invention relates to an aqueous emulsion comprising: a) from 50% to 60% of an organic phase dispersed in an aqueous phase, said organic phase containing a mixture including from 24% to 30%, calculated with respect to the final emulsion, of ethylene-vinyl acetate copolymers and/or polyalkyl(meth)acrylates, indicated in the present description as polymeric component, and a high-boiling organic solvent, or a mixture of said solvents; b) a primary emulsifier at a concentration higher or equal to 0.1% and lower than or equal to 3% by weight, calculated with respect to the final emulsion; c) from 37% to 47% of an aqueous phase; wherein the ratio between said polymer component and said organic solvent in the final aqueous emulsion is at least 1/1 and where the organic solvent and any polymer of the polymeric component have a Hildebrand solubility parameter ? such that, the difference (?solvent_?polymer) is lower than 2 in absolute value for any polymer of the polymeric component.

Abstract: Process for the preparation of a nitrile rubber comprising: —subjecting at least one ?,?-unsaturated nitrile, at least one conjugated diene and, optionally, one or more further copolymerizable monomers, to emulsion polymerization, in the presence of at least one alkyl thiol containing from 12 to 16 carbon atoms and at least three tertiary carbon atoms and having the sulfur bound to one of said tertiary carbon atoms, at a pH ranging from 7 to 10, preferably from 8 to 9, obtaining a latex; —subjecting said latex to coagulation, in the presence of at least one metal sulfate selected from magnesium, sodium, potassium, preferably magnesium, at a temperature higher than or equal to 30° C., preferably ranging from 40° C. to 60° C.

Abstract: Method for reducing the pressure drop associated with a fluid subjected to a turbulent flow which comprises introducing at least one latex into said fluid, comprising: (a) a continuous aqueous phase; (b) a plurality of particles, dispersed in said continuous aqueous phase, of at least one branched (co) polymer having a branching degree {GR) ranging from 0.05 to 0.6, preferably from 0.08 to 0.5, and a weight average molecular weight (Mw) of the parent (co) polymer ranging from 100,000 Daltons to 700,000 Daltons, preferably ranging from 140,000 Daltons to 350,000 Daltons. Said method can be advantageously used in the case of a pressure drop in pipelines transporting liquid hydrocarbons such as, for example, petroleum, crude oils and refinery or petrochemical products, in particular for long distances.

Abstract: Process for the preparation of a nitrile rubber comprising: —subjecting at least one ?,?-unsaturated nitrile, at least one conjugated diene and, optionally, one or more further copolymerizable monomers, to emulsion polymerization, in the presence of at least one alkyl thiol containing from 12 to 16 carbon atoms and at least three tertiary carbon atoms and having the sulfur bound to one of said tertiary carbon atoms, at a pH ranging from 7 to 10, preferably from 8 to 9, obtaining a latex; —subjecting said latex to coagulation, in the presence of at least one metal sulfate selected from magnesium, sodium, potassium, preferably magnesium, at a temperature higher than or equal to 30° C., preferably ranging from 40° C. to 60° C.

Abstract: Process for the elimination of residual mercaptans from nitrile rubbers, comprising: a. adding a colloidal emulsion of sulfur to a nitrile latex emulsion (NBR rubber latex) containing free mercaptan and with a pH of between 7 and 14, at a temperature ranging from 30 to 120° C.; b. coagulating the nitrile latex c. washing with demineralized water and drying the NBR rubber recovered after coagulation.

Abstract: A process is described for the preparation of latices based on polychloroprene, comprising the polymerization of chloroprene in the presence of a first latex essentially consisting of polymeric particles produced in a first polymerization of a composition of monomers comprising (a) alpha-, beta-unsaturated carboxylic acids and/or derivatives thereof, (b) vinyl aromatic compounds, (c) conjugated dienes; said first latex having a content of alpha-, beta-unsaturated carboxylic acids, expressed as parts of alpha-, beta-unsaturated carboxylic acids per 100 grams of polymeric particles, ranging from 1 to 15%, thus obtaining a final latex, the solid particles of said final latex having an quantity of chloroprene ranging from 50 to 95% by weight, preferably from 80 to 95% by weight.

Abstract: Process for the elimination of residual mercaptans from nitrile rubbers, comprising: a. adding a colloidal emulsion of sulfur to a nitrile latex emulsion (NBR rubber latex) containing free mercaptan and with a pH of between 7 and 14, at a temperature ranging from 30 to 120° C.; b. coagulating the nitrile latex c. washing with demineralized water and drying the NBR rubber recovered after coagulation.

Abstract: A process is described for the preparation of latices based on polychloroprene, comprising the polymerization of chloroprene in the presence of a first latex essentially consisting of polymeric particles produced in a first polymerization of a composition of monomers comprising (a) alpha-, beta-unsaturated carboxylic acids and/or derivatives thereof, (b) vinyl aromatic compounds, (c) conjugated dienes; said first latex having a content of alpha-, beta-unsaturated carboxylic acids, expressed as parts of alpha-, beta-unsaturated carboxylic acids per 100 grams of polymeric particles, ranging from 1 to 15%, thus obtaining a final latex, the solid particles of said final latex having an quantity of chloroprene ranging from 50 to 95% by weight, preferably from 80 to 95% by weight.

Abstract: A process is described for the preparation of latices based on polychloroprene, comprising the polymerization of chloroprene in the presence of a first latex essentially consisting of polymeric particles produced in a first polymerization of a composition of monomers comprising (a) alpha-, beta-unsaturated carboxylic acids and/or derivatives thereof, (b) vinyl aromatic compounds, (c) conjugated dienes; said first latex having a content of alpha-, beta-unsaturated carboxylic acids, expressed as parts of alpha-, beta-unsaturated carboxylic acids per 100 grams of polymeric particles, ranging from 1 to 15%, thus obtaining a final latex, the solid particles of said final latex having an quantity of chloroprene ranging from 50 to 95% by weight, preferably from 80 to 95% by weight.

Abstract: A process for the polymerization of chloroprene or of a mixture of chloroprene and of up to 20% by weight of a copolymerizable monomer, in aqueous emulsion in the presence of radical initiators, at a temperature of between 5° C. and 70° C., characterized in that the polymerization is carried out in the presence of one or more copolymerizable surfactants in agreement with the formula described below (I) R3—Z—CO—C(R1)═C(R2)—COOM  (I) where: R3 is a saturated or unsaturated, linear or branched and aliphatic or aromatic Cn hydrocarbonaceous chain with n from 10 to 20; R1 and R2, which are identical or different, are chosen from H or a C1-C3 alkyl radical; Z is chosen from —O— and —NH—; M is chosen from alkali metals or NH4.

Abstract: The disclosure is made of a process for the polymerization of chloroprene or of a mixture of chloroprene and of up to 20% by weight of a copolymerizable monomer, in aqueous emulsion in the presence of radical initiators, at a temperature of between 5° C. and 70° C.