Patent ID: 9376535
Filing Date: 2016-06-28
CPC Classification: B29C,C08G,C08L

Claim Text:
1. A process for the preparation of a high molecular weight branched polyamide comprising the steps of: (1) a melt-mixing step which comprises providing (i) a linear polyamide (pre)polymer (X-1) consisting essentially of AA-BB repeat units, (ii) a linear polyamide (pre)polymer (X-2) consisting essentially of AB repeat units, and (iii) a branching agent, to a melt mixing apparatus and mixing and heating components (i)-(iii) in the melt-mixing apparatus thereby forming a mixed melt, and thereafter cooling the mixed melt to thereby form a solid mixture; and (2) a solid state post condensation step which comprises subjecting the solid mixture to post-condensation at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide, wherein the (pre)polymers (X-1) and (X-2) are provided in a weight ratio (X-1)/(X-2) in a range of 0.25-4; the (pre)polymer (X-1) and/or the (pre)polymer (X-2) have a viscosity number (VN), measured according to ISO 307, in a range of 50-250 mL/g; the branching agent is a branched polyamide oligomer/prepolymer (Y) comprising (a) a branching unit formed from a monomer C having at least three functional groups, wherein the at least three functional groups may be the same or different and are selected from the group consisting of amino groups, carboxylic acid functional groups and alkyl ester or acid chloride derivatives thereof, and (b) AA-BB repeat units and/or AB repeat units; the branching unit is present in an amount in a range of 0.05-1 mole %, relative to the total molar amount of AA repeat units, BB repeat units and AB repeat units of the (pre)polymers (X-1) and (X-2) and the branched polyamide oligomer/prepolymer (Y); the high molecular weight branched polyamide obtained after the solid state post condensation step has a relative viscosity (RV) measured according to ISO 307 of at least 2.5, and the AA repeat units represent units derived from a diamine monomer A, the BB repeat units represent units derived from a dicarboxylic monomer B and the AB repeat units represent units derived from an α,ω-amino acid or a cyclic lactam derivative thereof.