Cellulose carbamate polymer
AssigneeInfinited Fiber Company Oy
InventorsErkki Malanin, Jani Mäkelä, Markus Nuopponen, Sakari Siren
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Abstract
The invention relates to a cellulose carbamate polymer having an average intrinsic viscosity of 146 to 368 ml/g, a nitrogen content of 0.01 to 3% by weight, a polydispersity index of 2.0 to 5.0, which has a content of p-terephthalate and/or p-terephthalic acid and/or unhydrolyzed or partly unhydrolyzed polyester of 0.00005 to 0.5% by weight.
Claims27
A cellulose carbamate polymer comprising:
- an average intrinsic viscosity of 146 to 368 ml/g;
- a nitrogen content of 0.01 to 3% by weight;
- a polydispersity index of 2.0 to 5.0;
- and
- a content of p-terephthalate and/or p-terephthalic acid and/or unhydrolyzed or partly unhydrolyzed polyester of 0.00005 to 0.5% by weight.
A composition comprising particulate cellulose carbamate, said particulate cellulose carbamate comprising particles having an average particle size wherein greater than or equal to 90 wt-% of the cellulose carbamate particles passes through a 260 μm sieve mesh, the share of less than 30 μm sieve fraction is greater than or equal to 10 wt-% and having an average intrinsic viscosity of 146 to 368 ml/g, a nitrogen content of 0.01 to 3% by weight, a polydispersity index of 2.0 to 5.0, and having a content of p-terephthalate and/or p-terephthalic acid and/or unhydrolyzed or partly unhydrolyzed polyethylene terephthalate of 0.00005 to 0.5% by weight.
A coagulated cellulose carbamate material comprising:
- an average an average intrinsic viscosity of 146 to 368 ml/g,
- a nitrogen content of up to 2% by weight;
- a polydispersity index of 2.0 to 5.0;
- and
- having a content of p-terephthalate and/or p-terephthalic acid and/or unhydrolyzed or partly unhydrolyzed polyethylene terephthalate of 0.00005 to 0.1% by weight.
A method for the manufacture of cellulose carbamate polymer, comprising:
- a mechanical pre-treatment of cellulose-based material comprising at least 50 wt-% of cellulose-containing waste, wherein at least 50 wt-% of the cellulose-containing waste is textile waste comprising polyester, the mechanical pre-treatment comprising at least grounding or shredding to elements having fibres of a length of ≤25 mm;
- an acidic treatment of the mechanically-treated cellulose-based material;
- an alkaline treatment after the acidic treatment, to at least partially hydrolyse the polyester;
- decolourising the treated cellulose-based material with ozone under alkaline conditions;
- and
- a cellulose carbamation step to form cellulose carbamate from the alkaline-treated cellulose-based material;
- wherein a polydispersity index of the resulting cellulose carbamate is adjusted to 2.0-5.0 by the acidic treatment.
Dependencies are inferred from the claim text.