阅读说明：本技术 透气膜 (Breathable film ) 是由 R·柯普林 D·贝克尔 C·迈尔 T·阿尔托 于 2020-05-02 设计创作，主要内容包括：本发明涉及透气膜。所述膜的比落球冲击下落高度为大于100 mm/(克聚合物/平方米)。所述膜具有在24小时内至少1000 g/m～(2)的水蒸气可透性。所述膜在机器方向上的断裂伸长率为小于200％。(The present invention relates to breathable films. The film has a specific falling ball impact drop height of greater than 100 mm/(gram polymer per square meter). The film has at least 1000 g/m in 24 hours 2 Water vapor permeability of (2). The film has an elongation at break in the machine direction of less than 200%.)

1. A breathable film characterized in that

-the film has a specific ball drop height of greater than 100 mm/(gram polymer/square meter), or the film has a specific dart drop of greater than 19 g/(gram polymer/square meter), or the film has a specific water column of greater than 90 mm/(gram polymer/square meter);

-and the film has a viscosity of at least 1000 g/m in 24 hours²Water vapor permeability of (a);

-and the film has an elongation at break according to the machine direction of less than 200%.

2. The film of claim 1, wherein the film has less than 17 g/m²Preferably less than 16 g/m²In particular less than 15 g/m²The areal density of (c).

3. The film according to claim 1 or 2, characterized in that the film has a melt flow index of less than 4 g/10min, preferably less than 3.7 g/10min, in particular less than 3.4 g/10min at 190 ℃ and 5 kg in each case.

4. A film according to any of claims 1 to 3, characterized in that it has a shrinkage in machine direction of less than 4%, preferably less than 3.5%, in particular less than 3%.

5. The film according to any one of claims 1 to 4, characterized in that it has a filler proportion of more than 20% by weight, preferably more than 30% by weight, in particular more than 40% by weight and/or less than 90% by weight, preferably less than 80% by weight, in particular less than 70% by weight.

6. The film according to any one of claims 1 to 5, characterized in that

-said film having a lower density LLDPE component, wherein said component has a density of less than 0.925 g/cm³Preferably less than 0.920 g/cm³And/or the density of the component is greater than 0.900 g/cm³Preferably greater than 0.910 g/cm³；

-and the film has a higher density LLDPE component, wherein the density of said component is greater than 0.925 g/cm³Preferably greater than 0.930 g/cm³And/or the density of the component is less than 0.950 g/cm³Preferably less than 0.945 g/cm³。

7. A film as claimed in claim 6, characterized in that the proportion of the lower density LLDPE component is more than 10% by weight, preferably more than 20% by weight, in particular more than 30% by weight, and/or less than 60% by weight, preferably less than 50% by weight, in particular less than 40% by weight.

8. A film according to claim 6 or 7, characterized in that the proportion of the LLDPE component of higher density is more than 2% by weight, preferably more than 4% by weight, in particular more than 5% by weight, and/or less than 12% by weight, preferably less than 10% by weight, in particular less than 8% by weight.

9. The film according to any one of claims 1 to 8, characterized in that it has a polypropylene component, preferably with a proportion of more than 0.5 wt. -%, preferably more than 1 wt. -%, in particular more than 2 wt. -% and/or less than 12 wt. -%, preferably less than 8 wt. -%, in particular less than 6 wt. -%.

10. The membrane according to any one of claims 1 to 9, characterized in that it has a thickness of less than 16 μ ι η, preferably less than 14 μ ι η, in particular less than 12 μ ι η and/or greater than 4 μ ι η, preferably greater than 6 μ ι η, in particular greater than 8 μ ι η.

11. A process for making a breathable film comprising the steps of:

-producing a composition comprising

A filler, which is a mixture of water and a filler,

a lower density LLDPE component,

a higher density LLDPE component,

-blow-extruding the composition to produce a film,

-stretching the film in the machine direction,

-guiding the film through at least one tempered roller to reduce the tendency to retract.

12. The method according to claim 11, characterized in that the film is stretched to more than 280%, preferably to more than 300%, in particular to more than 320% and/or to less than 400%, preferably to less than 375%, in particular to less than 350%.

13. Method according to claim 11 or 12, characterized in that the film is stretched at a temperature above 70 ℃, preferably above 80 ℃, in particular above 90 ℃ and/or below 120 ℃, preferably below 110 ℃, in particular below 100 ℃.

14. Method according to any one of claims 11 to 13, characterized in that the blow ratio in the blow extrusion is more than 1:1.5, preferably more than 1:2.0, in particular more than 1:2.5 and/or less than 1:4.5, preferably less than 1:4.0, in particular less than 1: 3.5.

15. Use of the breathable film according to any of claims 1 to 10 as backsheet in a diaper.