The present invention relates to a process for preparing a powder composition based on polyamide(s) with an optimized yield. The process includes a step of recycling a composition based on a polyamide prepolymer having a lower Dv50, by polycondensation of a mixture comprising said composition and one or more monomers in the presence of water. The invention also relates to the powder composition obtained and to the use thereof, especially for coating metal substrates by fluidized bed dip-coating.

The present invention relates to a process for preparing a powder composition based on polyamide(s) with an optimized yield. The process includes a step of recycling a composition based on a polyamide prepolymer having a lower Dv50, by polycondensation of a mixture comprising said composition and one or more monomers in the presence of water. The invention also relates to the powder composition obtained and to the use thereof, especially for coating metal substrates by fluidized bed dip-coating.

The present invention concerns a polymer comprising repetitive units having the following formula (I) wherein R.sub.1 is H or Me; L is a linker; R.sub.2 is the side chain of an α-amino acid being other than arginine; m is 0 or an integer comprised from 1 to 10; n is an integer comprised from 1 to 10; and X— is a counterion. ##STR00001##

The present invention concerns a polymer comprising repetitive units having the following formula (I) wherein R.sub.1 is H or Me; L is a linker; R.sub.2 is the side chain of an α-amino acid being other than arginine; m is 0 or an integer comprised from 1 to 10; n is an integer comprised from 1 to 10; and X— is a counterion. ##STR00001##

A base polyamide composition comprising a nylon mixture having caprolactam units from 1 wppb to 50 wppm catalyst composition; and greater than 0.75 wt % residual caprolactam, wherein the base polyamide composition has a delta end group level ranging from 30 μeq/gram to 90 μeq/gram.

A base polyamide composition comprising a nylon mixture having caprolactam units from 1 wppb to 50 wppm catalyst composition; and greater than 0.75 wt % residual caprolactam, wherein the base polyamide composition has a delta end group level ranging from 30 μeq/gram to 90 μeq/gram.

A process for production of a low-shrinkage aliphatic polyamide fibre, in which polyamide is extruded through a spinneret to form filaments, then cooled and combined to form at least one yarn. The at least one yarn is subjected to drawing between the spinneret and a pair of inlet rolls, then in a further multi-stage drawing step is subjected to 4-fold to 6-fold drawing by pairs of draw rolls. The pairs of draw rolls successively heat the yarn and at least the last pair of draw rolls has a temperature of 5° C. to 20° C. below the melting point of the yarn. The yarn is relaxed by from 6% to 10% in a subsequent at least three-stage relaxation zone and is kept in a temperature range of 5° C. to 15° C. below the melting point of the yarn, and is subsequently wound up on a reel device.

A process for production of a low-shrinkage aliphatic polyamide fibre, in which polyamide is extruded through a spinneret to form filaments, then cooled and combined to form at least one yarn. The at least one yarn is subjected to drawing between the spinneret and a pair of inlet rolls, then in a further multi-stage drawing step is subjected to 4-fold to 6-fold drawing by pairs of draw rolls. The pairs of draw rolls successively heat the yarn and at least the last pair of draw rolls has a temperature of 5° C. to 20° C. below the melting point of the yarn. The yarn is relaxed by from 6% to 10% in a subsequent at least three-stage relaxation zone and is kept in a temperature range of 5° C. to 15° C. below the melting point of the yarn, and is subsequently wound up on a reel device.

The present invention concerns a polymer comprising repetitive units having the following formula (I) wherein R.sub.1 is H or Me; L is a linker; R.sub.2 is the side chain of an α-amino acid being other than arginine; m is 0 or an integer comprised from 1 to 10; n is an integer comprised from 1 to 10; and X— is a counterion.

##STR00001##

The present invention concerns a polymer comprising repetitive units having the following formula (I) wherein R.sub.1 is H or Me; L is a linker; R.sub.2 is the side chain of an α-amino acid being other than arginine; m is 0 or an integer comprised from 1 to 10; n is an integer comprised from 1 to 10; and X— is a counterion.

##STR00001##