Melt blown fiber

Patent metadata

Field	Value
Publication number	US-8999867-B2
Application number	US-201113575469-A
Country	US
Kind code	B2
Filing date	Jan 19, 2011
Priority date	Jan 28, 2010
Publication date	Apr 7, 2015
Grant date	Apr 7, 2015

Abstract

Melt-blown fiber having an average diameter of not more than 5.0 μm, said fiber comprises at least 85 wt.-% of a propylene copolymer, wherein •said melt blown fiber and/or said propylene copolymer has/have a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 200 g/10 min, •said propylene copolymer has a comonomer content of 0.5 to 5.5 wt.-%, the comonmers are ethylene and/or at least one C 4 to C 20 α-olefin selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, •the propylene copolymer has <2,1> regiodefects of not more than 0.4 mol.-% determined by 13 C-spectroscopy, and •said melt blown fiber and/or said propylene copolymer fulfill(s) the equation (1). wherein Tm [° C.] is the melting temperature [given in ° C.] of melt blown fiber said and/or of said propylene copolymer measured according to ISO 11357-3, C2 [wt %] is the amount [given in weight percentage] of comonomers within said melt blown fiber and/or within said propylene copolymer determined with Fourier transform infrared spectroscopy (FTIR).

Tm
⁡

[

°
⁢

⁢

C
.

]

[

°
⁢

⁢

C
.

]

≥

160
-

C
⁢

⁢

2
⁡

[

wt
⁢

⁢
%

]

×
5.25

[

wt
⁢

⁢
%

]

(
1
)

First claim

We claim:

1. Melt-blown fiber having an average diameter of not more than 5.0 μm, said fiber comprises at least 85 wt.-% of a propylene copolymer, wherein said propylene copolymer is the only polymer in the melt-blown fiber,
and wherein further
(a) said melt blown fiber and/or said propylene copolymer has/have a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 200 g/10 min,
(b) said propylene copolymer has a comonomer content of 0.5 to 5.5 wt.-%, the comonmers are ethylene and/or at least one C 4 to C 20 α-olefin selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene,
(c) the propylene copolymer has <2,1> regiodefects of not more than 0.1 mol.-% determined by 13 C-spectroscopy, and
(d) said melt blown fiber and/or said propylene copolymer fulfill(s) the equation (1)

Tm
⁡

[

°
⁢

⁢

C
.

]

[

°
⁢

⁢

C
.

]

≥

160
-

C
⁢

⁢

2
⁡

[

wt
⁢

⁢
%

]

×
5.25

[

wt
⁢

⁢
%

]

(
1
)

wherein
Tm [° C.] is the melting temperature [given in ° C.] of said melt blown fiber and/or of said propylene copolymer measured according to ISO 11357-3,
C2 [wt %] is the amount [given in weight percentage] of comonomers within said melt blown fiber and/or within said propylene copolymer determined with Fourier transform infrared spectroscopy (FTIR).

2. Melt blown fiber according to claim 1 , wherein said propylene copolymer and/or said melt blown fiber has a melting temperature of at least 140° C.

3. Melt blown fiber according to claim 1 , wherein the fiber comprises at least 90 wt.-% of the propylene copolymer.

4. Melt blown fiber according to claim 1 , wherein the pentad isotacticity of the propylene copolymer is higher than 95 mol.-% determined with 13 C NMR spectroscopy.

5. Melt blown fiber according to claim 1 , wherein the propylene copolymer has a molecular weight distribution (M w /M n ) of 2.0 to 6.0.

6. Melt blown fiber according to claim 1 , wherein the propylene copolymer has been visbroken with a visbreaking ratio [final MFR 2 (230° C.)/initial MFR 2 (230° C.)] of 5.0 to 100.0, wherein
“initial MFR 2 (230° C.)” is the MFR 2 (230° C.) of the propylene copolymer before visbreaking and
“final MFR 2 (230° C.)” is the MFR 2 (230° C.) of the propylene copolymer (R-PP) after visbreaking.

7. Melt blown fiber according to claim 1 , wherein the melt blown fiber and/or the propylene copolymer fulfill(s) the equation (2)

TM
⁡

[
MPa
]

[
MPa
]

≥

1200
-

C
⁢

⁢

2
⁡

[

wt
⁢

⁢
%

]

×
145

[

wt
⁢

⁢
%

]

(
2
)

wherein
TM [MPa] is the tensile modulus [given in MPa] of said melt blown fiber and/or of said propylene copolymer measured according to ISO 527-3 using injection molded specimen as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness),
C2 [wt %] is the amount [given in weight percentage] of comonomers, within said melt blown fiber and/or within said propylene copolymer determined with Fourier transform infrared spectroscopy (FTI

Assignees

• Van Paridon Henk
• Broeders Bert
• Sars Wilhelmus Henricus Adolf
• Fiebig Joachim
• Ackermans Nina
• Borealis Ag

Inventors

• Van Paridon Henk
• Broeders Bert
• Sars Wilhelmus Henricus Adolf
• Fiebig Joachim
• Ackermans Nina

Classifications

• D04H3/007

  Addition polymers · CPC title

• D01F6/30 Primary

  comprising olefins as the major constituent · CPC title

• D04H3/16

  with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion · CPC title

• C08F210/06

  Propene · CPC title

• C08F210/16

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title