Process for preparing a lubricated thermoplastic polymer
A method for preparing a lubricated thermoplastic polymer, in particular a lubricated polyamide is described. A method for preparing a lubricated thermoplastic polymer, in particular a lubricated polyamide, according to which a mixture of lubricants is added to the molten polymer during the polymerization process is also described.
1. A process for preparing a lubricated thermoplastic polymer, the process comprising
(i) concentrating at least one monomer in water to form a molten phase comprising the at least one monomer;
(ii) polymerizing the at least one monomer with a pressurized distillation phase and a decompression phase to form a polymer in the melt state; and
(iii) introducing a lubricant:
(a) into the polymer in the melt state or
(b) into the molten phase comprising monomers that form a polymer during polymerization,
wherein the lubricant is a mixture of a paraffin, a fatty acid and a fatty acid metal salt,
and wherein the lubricant is the only lubricant introduced into the polymer or into the molten phase,
wherein the thermoplastic is a polyamide
wherein the process does not include a supplementary step of depositing lubricant on granules.
2. The process according to claim 1 , wherein the paraffin has an average number of carbon atoms which is between 20 and 500.
3. The process according to claim 1 , wherein the lubricant is in an amount of between 0.1 and 5% by weight relative to the weight of polymer.
4. The process according to claim 1 , wherein the process further comprises a finishing step comprising use of a finishing device having an inlet and an outlet, wherein the lubricant is introduced before the outlet of the finishing device.
5. The process according to claim 1 , wherein the lubricant is introduced after the decompression phase.
6. The process according to claim 1 , wherein the decompression phase is carried out with a flasher having an inlet, and wherein the lubricant is introduced at the inlet of the flasher.
7. The process according to claim 1 , wherein the process further comprises a finishing step comprising use of a finishing device having an inlet and an outlet, wherein the lubricant is introduced at the inlet or at the outlet of the finishing device.
8. The process according to claim 1 , wherein the polymer, when the lubricant is introduced, has not undergone a remelting step.
9. The process according to claim 2 , wherein the paraffin has an average number of carbon atoms which is between 30 and 200.
10. A process for preparing a lubricated thermoplastic polymer, the process comprising
(i) concentrating at least one monomer in water to form a molten phase comprising the at least one monomer;
(ii) polymerizing the at least one monomer with a pressurized distillation phase and a decompression phase to form a polymer in the melt state; and
(iii) introducing a lubricant:
(a) into the polymer in the melt state or
(b) into the molten phase comprising monomers that form the polymer during polymerization,
wherein the lubricant consists essentially of a mixture of a paraffin, a fatty acid and a fatty acid metal salt,
and wherein the lubricant is the only lubricant introduced into the polymer or into the molten phase,
wherein the thermoplastic polymer is a polyamide,
wherein the process does not include a supplementary step of depositing lubricant on granules.