Semi-crystalline thermoplastic polyester for producing fibres

A method for the production of a fiber, comprising the following steps of:

• Provision of a semicrystalline thermoplastic polyester comprising at least one 1,4:3,6-dianhydrohexitol unit (A), at least one alicyclic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A), at least one terephthalic acid unit (C), wherein the (A)/[(A)+(B)] molar ratio is at least 0.05 and at most 0.30, said polyester not containing any aliphatic non-cyclic diol units or comprising a molar amount of aliphatic non-cyclic diol units, relative to all the monomer units of the polyester, of less than 5%, and the reduced solution viscosity (25° C.;
• phenol (50% m):ortho-dichlorobenzene (50% m);
• 5 of polyester) of said polyester being greater than 50 ml/g;
• Preparation of said fiber from the semicrystalline thermoplastic polyester obtained in the preceding step.

A fiber comprising a semicrystalline thermoplastic polyester comprising:

• at least one 1,4:3,6-dianhydrohexitol unit (A);
• at least one alicyclic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A);
• at least one terephthalic acid unit (C);
• wherein the (A)/[(A)+(B)] molar ratio is at least 0.05 and at most 0.30;
• said polyester not containing any aliphatic non-cyclic diol units or comprising a molar amount of aliphatic non-cyclic diol units, relative to all the monomer units of the polyester, of less than 5%, and the reduced solution viscosity (25° C.;
• phenol (50% m):ortho-dichlorobenzene (50% m);
• 5 g/l of polyester) of said polyester being greater than 50 ml/g.

A method for the production of a textile, comprising the following steps of:

• Provision of a fiber comprising a semicrystalline thermoplastic polyester comprising:
• at least one 1,4:3,6-dianhydrohexitol unit (A);
• at least one alicyclic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A);
• at least one terephthalic acid unit (C);
• wherein the (A)/[(A)+(B)] molar ratio is at least 0.05 and at most 0.30;
• said polyester not containing any aliphatic non-cyclic diol units or comprising a molar amount of aliphatic non-cyclic diol units, relative to all the monomer units of the polyester, of less than 5%, and the reduced solution viscosity (25° C.;
• phenol (50% m):ortho-dichlorobenzene (50% m);
• 5 g/l of polyester) of said polyester being greater than 50 μg;
• and
• Preparation of said textile from the fiber obtained in the preceding step.

A method for the production of a nonwoven, comprising the following steps of:

• Provision of a fiber comprising a semicrystalline thermoplastic polyester comprising:
• at least one 1,4:3,6-dianhydrohexitol unit (A);
• at least one alicyclic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A);
• at least one terephthalic acid unit (C);
• wherein the (A)/[(A)+(B)] molar ratio is at least 0.05 and at most 0.30;
• said polyester not containing any aliphatic non-cyclic diol units or comprising a molar amount of aliphatic non-cyclic diol units, relative to all the monomer units of the polyester, of less than 5%, and the reduced solution viscosity (25° C.;
• phenol (50% m):ortho-dichlorobenzene (50% m);
• 5 g/l of polyester) of said polyester being greater than 50 μg;
• and
• Preparation of said nonwoven from the fiber obtained in the preceding step.