Vinylidene fluoride polymer dispersion
AssigneeSolvay Specialty Polymers Italy S.P.A.
InventorsSerena Carella, Mirko Mazzola, Marco Avataneo, Andrea Vittorio Oriani, Emanuele Di Nicolo′
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Abstract
The present invention pertains to an aqueous dispersion of a vinylidene fluoride polymer having a high molecular weight and possessing a substantially linear structure, leading to reduced amount of gels/insoluble fractions, to a method for its preparation and to its use for the manufacture of electrochemical cell components, such as electrodes and/or composite separators or for the manufacture of membranes.
Claims20
An aqueous dispersion [dispersion (D)] comprising particles of a vinylidene fluoride (VDF) polymer [polymer (A)] comprising recurring units derived from vinylidene fluoride (VDF) monomer, said polymer (A) comprising
- (i) more than 85.0% moles of recurring units derived from VDF, with respect to the total number of recurring units of polymer (A);
- (ii) sulphur-containing chain ends;
- (iii) a weight averaged molecular weight (Mw) of at least 500 KDalton, when measured by GPC, using N,N-dimethylacetamide (DMA) as solvent, against monodisperse polystyrene standards;
- wherein the relation between melt viscosity (MV) in KPoise determined at a shear rate of 100 sec−1, and at a temperature of 230° C., according to ASTM D3835, and Mw, expressed in KDalton, satisfies the following inequality:
- 0.025×Mw (KDalton)+13≤MV (KPoise)≤0.050×Mw (KDalton)+10.
A powder [powder (P)] comprising particles of a vinylidene fluoride (VDF) polymer [polymer (A)] comprising recurring units derived from vinylidene fluoride (VDF) monomer, said polymer (A) comprising:
- (i) more than 85.0% moles of recurring units derived from VDF, with respect to the total number of recurring units of polymer (A);
- (ii) sulphur-containing chain ends;
- (iii) a weight averaged molecular weight (Mw) of at least 500 KDalton, when measured by GPC, using N,N-dimethylacetamide (DMA) as solvent, against monodisperse polystyrene standards;
- wherein the relation between melt viscosity (MV) in KPoise determined at a shear rate of 100 sec−1, and at a temperature of 230° C., according to ASTM D3835, and Mw, expressed in KDalton, satisfies the following inequality:
- 0.025×Mw(KDalton)+13≤MV(KPoise)≤0.050×Mw(KDalton)+10,
- wherein said particles of polymer (A) possess a primary particle average size of less than 1 μm, preferably a primary particles average size of above 20 nm and below 350 nm.
A vinylidene fluoride (VDF) polymer [polymer (A)] comprising recurring units derived from vinylidene fluoride (VDF) monomer, said polymer (A) comprising:
- (i) comprising more than 85.0% moles of recurring units derived from VDF, with respect to the total number of recurring units of polymer (A);
- (ii) sulphur-containing chain ends;
- (iii) a weight averaged molecular weight (Mw) of at least 500 KDalton, when measured by GPC, using N,N-dimethylacetamide (DMA) as solvent, against monodisperse polystyrene standards;
- wherein the relation between melt viscosity (MV) in KPoise determined at a shear rate of 100 sec−1, and at a temperature of 230° C., according to ASTM D3835, and Mw, expressed in KDalton, satisfies the following inequality:
- 0.025×Mw(KDalton)+13≤MV(KPoise)≤0.050×Mw(KDalton)+10.
Dependencies are inferred from the claim text.