Terpolymer for melt blown media for air filtration

Patent metadata

Field	Value
Publication number	US-9255349-B2
Application number	US-201213981407-A
Country	US
Kind code	B2
Filing date	Jan 9, 2012
Priority date	Jan 28, 2011
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

Melt-blown fiber comprising a terpolymer of propylene, ethylene and a C 4 to C 10 α-olefin, wherein further said melt blown fiber and/or said terpolymer has/have a melt flow rate MFR25 (230° C.) of at least 300 g/10 min, the amount of propylene in said terpolymer is at least 90.0 wt.-%, the weight ratio of ethylene and α-olefin within said terpolymer is 1/100 to below 1/1, and the terpolymer has <2,1> regiodefects of below 0.4 mol.-% 0.10.

First claim

We claim:

1. Melt-blown fiber comprising a terpolymer of propylene (C3), ethylene (C2) and a C 4 to C 10 α-olefin (αO), wherein further
(a) said melt blown fiber and/or said terpolymer has/have a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 300 g/10 min,
(b) the amount of propylene (C3) in said terpolymer is at least 90.0 wt.-%,
(c) the weight ratio of ethylene to C 4 to C 10 α-olefin [C2/αO] within said terpolymer is 1/100 to below 1/1, and
(d) the terpolymer has <2,1> regiodefects of below 0.4 mol.-% determined by 13 C-spectroscopy.

2. Melt-blown fiber according to claim 1 , wherein the melt-blown fiber has an average diameter of equal or below than 5.0 μm.

3. Melt-blown fiber according to claim 1 , wherein
(a) the amount of ethylene (C2) of said terpolymer is in the range of 0.1 to 3.0 wt.-%,
and/or
(b) the amount of α-olefin (αO) of said terpolymer is in the range of 1.5 to 6.0 wt.-%.

4. Melt-blown fiber according to claim 1 , wherein said melt blown fiber and/or said terpolymer fulfill(s) the equation (1)

Tm
⁡

[

°
⁢

⁢

C
.

]

[

°
⁢

⁢

C
.

]

≥

160
-

α
⁡

[

wt
⁢

⁢
%

]

×
5.25

[

wt
⁢

⁢
%

]

(
1
)

wherein
Tm [° C.] is the melting temperature [given in ° C.] of said melt blown fiber and/or of said terpolymer measured according to ISO 11357-3,
α [wt %] is the amount [given in weight percentage] of comonomers, i.e. of ethylene (C2) and the α-olefin (αO) together, within said melt blown fiber and/or within said terpolymer determined 13 C nuclear magnetic resonance spectroscopy ( 13 C-NMR).

5. Melt-blown fiber according to claim 1 , wherein the melt-blown fiber and/or the terpolymer has/have
(a) a weight average molecular weight (Mw) of equal or below 95,000 g/mol,
and/or
(b) a molecular weight distribution (M w /M n ) of 2.0 to 6.0
measured by size exclusion chromatography (SEC) according to ISO 16014.

6. Melt-blown fiber according to claim 1 , wherein the melt-blown fiber and/or the terpolymer has/have a xylene cold soluble fraction (XCS) measured according to ISO 16152 (25° C.) in the range of 1.0 to 12.0 wt.-%.

7. Melt-blown fiber according to claim 1 , wherein the melt-blown fiber and/or the terpolymer has/have
(a) melting temperature Tm in the range of 125 to 155° C.,
and/or
(b) a crystallization temperature Tc of equal or below than 115° C.
measured according ISO 11357-3.

8. Melt-blown fiber according to claim 1 , wherein the terpolymer is vis-broken.

9. Melt-blown fiber according to claim 1 , wherein
(a) the terpolymer is the only polymer within the melt-blown fiber,
and/or
(b) the melt-blown fiber comprises at least 85 wt.-% of the terpolymer.

10. Melt-blown web comprising melt-blown fibers according to claim 1 .

11. Melt-blown web according to claim 10 having a weight per unit area of at least 15 g/m 2 .

12. Article comprising a melt-blown fiber according to claim 1 , said article is selected from the group consisting of filtration medium, diaper, sanitary napkin, panty liner, incontinence product for adults, protective clothing, surgical drape, surgical gown, and surgical wear.

13. Process for the preparation of a melt-blown fibers comprising steps of:
providing a terpolymer of propylene (C3), ethylene (C2) and a C 4 to C 10 α-olefin (αO), wherein further
(a) said melt blown fiber and/or said terpolymer has/have a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 300 g/10 min,
(b) the amount of propylene (C3) in said terpolymer is at least 90.0 wt.-%,
(c) the weight ratio of ethylene to C 4 to C 10 α-olefin [C2/αO] within said terpolymer is 1/100 to below 1/1, and
(d) the terpolymer has <2,1> regiodefects of below 0.4 mol.-% determined by 13 C-spectroscopy
melt blowing said terpolymer by using a melt blown plant having a die with holes of 0.3 to 0.5 mm diameter and 10 to 16 holes per cm.

14. Use of a terpolymer as defined in claim 1 for the preparation of a melt-blown fiber
producing a melt-blown web comprising melt-blown fibers, said melt-blown fibers having a weight per unit area of at least 15 g/m 2 .

15. Use of a terpolymer as defined in claim 1 to increase the quality factor (QF) of a melt blown web by at least 10%, wherein the increase is defined by formula (III)

10
⁢
%

=

QF
⁢

⁢

(
T
)

-

Assignees

• Van Paridon Henk
• Tynys Antti
• Fiebig Joachim
• Parkinson Matthew
• Borealis Ag

Inventors

• Van Paridon Henk
• Tynys Antti
• Fiebig Joachim
• Parkinson Matthew

Classifications

• D04H1/4382

  Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather · CPC title

• D01D5/0985 Primary

  by means of a flowing gas (e.g. melt-blowing) · CPC title

• D01F6/30

  comprising olefins as the major constituent · CPC title

• D04H1/56

  in association with fibre formation, e.g. immediately following extrusion of staple fibres · CPC title

• D01F6/06 Primary

  from polypropylene · CPC title