POLYMER FIBRE HAVING IMPROVED DISPERSIBILITY

Abstract

The invention relates to a polymer fibre with improved dispersibility, a method for producing said fibre and the use of said fibre.

The polymer fibre according to the invention comprises at least one synthetic polymer and 0.1 and 20 wt. % of a silicone. The polymer forming the fibre forms a solid dispersion medium at room temperature (25 C.) for the silicone present in solid form also at room temperature (25 C.) which forms the more disperse phase.

The polymer fibre according to the invention possesses an improved dispersibility and is therefore suitable for producing aqueous suspensions which are used, for example, in the formation of textile fabrics, e.g. nonwovens.

Claims

1. A polymer fibre comprising at least one synthetic polymer, characterized in that the polymer forming the fibres in the form of a solid dispersion medium at room temperature (25 C.) comprises between 0.1 and 20 wt. % of a silicone in the form of a solid more disperse phase at room temperature (25 C.).

2. The polymer fibre according to claim 1, characterized in that the synthetic polymer which forms the solid dispersion medium is a thermoplastic polymer.

3. The polymer fibre according to claim 2, characterized in that the thermoplastic polymer which forms the solid dispersion medium is a thermoplastic polycondensate, preferably a thermoplastic polycondensate based on biopolymers.

4. The polymer fibre according to claim 3, characterized in that the thermoplastic polycondensate based on biopolymers which forms the solid dispersion medium is a thermoplastic polycondensate based on lactic acids.

5. The polymer fibre according to claim 4, characterized in that the thermoplastic polycondensate based on lactic acids is a polylactic acid whose number average molecular weight (Mn) is between 10,000 g/mol and 500,000 g/mol.

6. The polymer fibre according to claim 4, characterized in that the thermoplastic polycondensate based on lactic acids is a polylactic acid whose weight average molecular weight (Mw) is between 30,000 g/mol and 500,000 g/mol.

7. The polymer fibre according to one or more of claims 1 to 6, characterized in that the silicone which forms the disperse phase is present in carried form on a particulate silicate carrier, preferably on pyrogenic silicic acid.

8. The polymer fibre according to one or more of claims 1 to 7, characterized in that the silicone comprises cyclic polysiloxanes, linear polysiloxanes, branched polysiloxanes, cross-linked polysiloxanes as well as mixtures of the same.

9. The polymer fibre according to one or more of claims 1 to 7, characterized in that the silicone is a linear silicone polymer, preferably a non-cross-linked linear silicone polymer.

10. The polymer fibre according to one or more of claims 1 to 7 and according to claim 9, characterized in that the silicone is a high-molecular linear silicone polymer, preferably a high-molecular non-cross-linked linear silicone polymer.

11. The polymer fibre according to claim 10, characterized in that the silicone polymer has a mean molecular weight of at least 100,000 g/mol, preferably at least 150,000 g/mol, particularly preferably at least 200,000 g/mol, and that the maximum mean molecular weight is up to 900,000 g/mol, preferably up to 700,000 g/mol, particularly preferably up to 650,000 g/mol, in particular up to 600,000 g/mol.

12. The polymer fibre according to claim 10, characterized in that the silicone polymer has a dynamic viscosity measured at 25 C. in accordance with DIN 53018 of at least 10,000 Pa*s, preferably at least 15,000 Pa*s, particularly preferably at least 17,500 Pa*s, and a maximum of 60,000 Pa*s, preferably a maximum of 55,000 Pa*s, particularly preferably a maximum of 50,000 Pa*s, in particular a maximum of 45,000 Pa*s.

13. The polymer fibre according to claim 10, characterized in that the silicone polymer has a kinematic viscosity measured at 25 C. of at least 10,000,000 cSt, preferably at least 15,000,000 cSt, particularly preferably at least 17,500,000 cSt, and a maximum of 60,000,000 cSt, preferably a maximum of 55,000,000 cSt particularly preferably a maximum of 50,000,000 cSt, in particular a maximum of 45,000,000 cSt.

14. The polymer fibre according to one or more of claims 1 to 13, characterized in that the fibre has a titre between 0.3 and 30 dtex, preferably 0.5 to 13 dtex, and is preferably present as staple fibre, in particular as crimped staple fibre.

15. The polymer fibre according to one or more of claims 1 to 14, characterized in that the fibre is present in the form of a bicomponent fibre of the core-cladding type, wherein the polymer forming the cladding in the form of a solid dispersion medium at room temperature (25 C.) comprises between 0.1 and 20 wt. % of a silicone in the form of a solid more disperse phase at room temperature (25 C.).

16. The polymer fibre according to one or more of claims 1 to 14 or 15, characterized in that the dispersion medium comprises between 0.5 and 3 wt % silicone as solid more disperse phase.

17. A textile fabric, in particular obtainable by a wet laying method containing polymer fibres defined in claims 1 to 16.

18. Use of the polymer fibre defined in claims 1 to 16 to produce aqueous suspensions.

Description

EXAMPLE 1

[0092] 1 gram of thermoplastic polymer fibre according to the invention (polyester) having a cut length of 6 mm and a titre of 1.5 dtex (silicone additive 1.5 wt. %) was dispersed at room temperature (25 C.) as described hereinbefore and assessed.

[0093] For comparison 1 gram of thermoplastic polymer fibre (polyester) having a cut length of 6 mm and a titre of 1.5 dtext without the addition of silicone additive according to the invention but otherwise identical was dispersed at room temperature (25 C.) as described hereinbefore and assessed.

[0094] The results are combined in the following table:

TABLE-US-00001 Dispersion behaviour (after Fibre (according to Fibre switching off the agitator) the invention) (comparison) 0 min + 1 min + 3 min + 5 min + 10 min +

[0095] FIG. 1 shows the dispersion behaviour directly after switching off the agitator. FIG. 1a shows the fibre according to the invention, FIG. 1b shows the same fibre without the additive according to the invention.

EXAMPLE 2

[0096] 1 gram of thermoplastic polymer fibre according to the invention based on a synthetic biopolymer (PLA) having a cut length of 4 mm and a titre of 1.5 dtex (silicone additive 3 wt. %) was dispersed at room temperature (25 C.) as described hereinbefore and assessed.

[0097] For comparison 1 gram of thermoplastic polymer fibre according to the invention based on a synthetic biopolymer (PLA) having a cut length of 4 mm and a titre of 1.5 dtex without the addition of silicone additive according to the invention but otherwise identical was dispersed at room temperature (25 C.) as described hereinbefore and assessed.

[0098] The results are combined in the following table:

TABLE-US-00002 Dispersion behaviour (after Fibre (according to Fibre switching off the agitator) the invention) (comparison) 0 min + 1 min + 3 min + 5 min + 10 min +

[0099] FIG. 2 shows the dispersion behaviour directly after switching off the agitator. FIG. 2a shows the fibre according to the invention, FIG. 2b shows the same fibre without the additive according to the invention.

EXAMPLE 3

[0100] 1 gram of thermoplastic bicomponent polymer fibre according to the invention (core/cladding 50/50) based on a synthetic biopolymer (PLA) as core and a polyethylene homopolymer as cladding (additive according to the invention in PE cladding, 3 wt. % silicone additive in cladding) having a cut length of 4 mm and a titre of 2 dtex was dispersed at room temperature (25 C.) as described hereinbefore and assessed.

[0101] For comparison 1 gram of thermoplastic bicomponent polymer fibre according to the invention (core/cladding 50/50) based on a synthetic biopolymer (PLA) as core and a polyethylene homopolymer as cladding (in each case without the addition of silicone additive) having a cut length of 4 mm and a titre of 2 dtex was dispersed at room temperature (25 C.) as described hereinbefore and assessed.

[0102] The results are combined in the following table:

TABLE-US-00003 Dispersion behaviour (after Fibre (according to Fibre switching off the agitator) the invention) (comparison) 0 min + 1 min + 3 min + 5 min + 10 min +

[0103] FIG. 3 shows the dispersion behaviour directly after switching off the agitator. FIG. 3a shows the bicomponent fibre according to the invention, FIG. 3b shows the same bicomponent fibre without the additive according to the invention.