# US 2014/0155854 A1 · Polypropylene fibers and fabrics

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- Number: US 2014/0155854 A1
- Document ID: US20140155854A1
- Status: Published application
- Kind: A1
- Application number: 13/691,984
- Filed: 2012-12-03
- Published: 2014-06-05
- Earliest claimed: 2012-12-03
- Assignees: Reifenhauser GmbH & Co. Maschinenfabrik; ExxonMobil Chemical Patents Inc.
- Applicants: Exxonmobil Chemical Patents Inc.; Reifenhauser GmbH & Co. KG Maschinenfabrik
- Inventors: Jeanne Marie MacDonald; Antonios K. Doufas; Jerome Sarrazin; William Michael Ferry; Rahul Ravindra Kulkarni; Derek Wade Thurman; Cynthia Ann Mitchell; Detlef Frey; Peter Schlag; Hans-Georg Geus; Claudio Cinquemani
- Web page: https://patentgrep.com/patent/US20140155854A1

## CPC

- D01F 6/06: from polypropylene
- A61F 13/53: characterised by the absorbing medium (A61F13/20 takes precedence)
- D04H 1/435: Polyesters
- D04H 3/007: Addition polymers
- D04H 3/14: with bonds between thermoplastic yarns or filaments produced by welding
- A61F 2013/530226: {with polymeric fibres}
- C08L 23/10: Homopolymers or copolymers of propene
- C08L 2203/12: used for fibers
- D10B 2321/022: polypropylene
- D10B 2509/026: Absorbent pads; Tampons; Laundry; Towels
- Y10T 428/2904: Staple length fiber
- Y10T 428/298: Physical dimension
- Y10T 442/60: Nonwoven fabric [i.e., nonwoven strand or fiber material]
- Y10T 442/608: Including strand or fiber material which is of specific structural definition
- Y10T 442/66: Additional nonwoven fabric is a spun-bonded fabric
- Y10T 442/671: Multiple nonwoven fabric layers composed of the same polymeric strand or fiber material
- Y10T 442/68: Melt-blown nonwoven fabric
- Y10T 442/681: Spun-bonded nonwoven fabric
- Y10T 442/696: Including strand or fiber material which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous compositions, water solubility, heat shrinkability, etc.]
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- D04H: MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL (weaving D03; knitting D04B; braiding D04C; net-making D04G; sewing D05B; tufting D05C; finishing non-woven fabrics D06); FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING {; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION}(non-woven fabrics having an intermediate or external layer of a different kind, e.g. of woven fabric, B32B)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- D10B: INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

This invention relates to polypropylene fibers and fabrics containing polypropylene fibers, the fibers comprising propylene polymers comprising at least 50 mol % propylene, said polymers having: a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of about 10 dg/min to about 25 dg/min; b) a dimensionless Stress Ratio/Loss Tangent Index R2 [defined by Eq. (8)] at 190° C. from about 1.5 to about 30; c) an onset temperature of crystallization under flow, Tc,rheol, (as determined by SAOS rheology, 190° C., 1° C./min, where said polymer has 0 wt % nucleating agent present), of at least about 123° C.; d) an average meso run length determined by 13C NMR of at least about 55 or higher; and e) optionally, a loss tangent, tan δ, [defined by Eq. (2)] at an angular frequency of 0.1 rad/s at 190° C. from about 14 to about 70.

## Claims

### Claim 1

A nonwoven fabric comprising polypropylene fibers, wherein said polypropylene fibers comprise a propylene polymer comprising at least 50 mol % propylene, said polymer having:
a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of about 10 dg/min to about 21.5 dg/min;
b) a dimensionless Stress Ratio/Loss Tangent Index R2 [defined by Eq. (8) herein] at 190° C. from about 1.5 to about 28;
c) an onset temperature of crystallization under flow, Tc,rheol, (as determined by SAOS rheology, 1° C./min as described herein, where said polymer has 0 wt % nucleating agent present), of at least about 131° C.; and
d) an average meso run length determined by 13C NMR of at least about 97 or higher.

### Claim 2 (depends on 1)

A nonwoven fabric according to claim 1, wherein said polypropylene fibers are present in an amount of at least 50% by weight, preferably at least 75% by weight, based on the total weight of fibers in said nonwoven fabric.

### Claim 3 (depends on 1)

A nonwoven fabric according to claim 1, having a fabric basis weight in the range of 5 to 70 gsm, preferably 7 to 15 gsm.

### Claim 4 (depends on 1)

A nonwoven fabric according to claim 1, having a tensile strength anisotropy defined as the ratio of the specific tensile strength in the MD over the specific tensile strength in the CD of less than about 2.7.

### Claim 5 (depends on 1)

A nonwoven fabric according to claim 1, having a total hand of less than about 6.8 gr.

### Claim 6 (depends on 1)

A nonwoven fabric according to claim 1, having a MD tensile modulus (as defined herein) of less than about 35 N/5 cm/gsm.

### Claim 7 (depends on 1)

A nonwoven fabric according to claim 1, having a CD specific tensile strength of at least 1.0 N/5 cm/gsm, a MD specific tensile strength of at least 2.7 N/5 cm/gsm and a total hand of less than about 6.8 gm force or a tensile modulus of less than about 32 N/5 cm/gsm.

### Claim 8 (depends on 7)

A nonwoven fabric according to claim 7, having a fabric tensile anisotropy (ratio of MD over CD specific tensile strength as defined herein) of less than about 2.7.

### Claim 9 (depends on 1)

A nonwoven fabric according to claim 1, having a CD specific tensile strength of at least 1.1 N/5 cm/gsm, MD specific tensile strength of at least 2.9 N/5 cm/gsm, and total hand of less than about 6.6 gm force or MD tensile modulus of less than about 30 N/5 cm/gsm.

### Claim 10 (depends on 1)

A nonwoven fabric according to claim 1, wherein said propylene polymer has:
a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of about 14 dg/min to about 19 dg/min;
b) a dimensionless Stress Ratio/Loss Tangent Index R2 [defined by Eq. (8) herein] at 190° C. from about 2.5 to about 6.5;
c) an onset temperature of crystallization under flow, Tc,rheol, (as determined by SAOS rheology, 1° C./min as described below, where said polymer has 0 wt % nucleating agent present), of at least about 136° C.; and
d) an average meso run length determined by 13C NMR of from 97 to 140.

### Claim 11 (depends on 1)

A nonwoven fabric according to claim 1, wherein the fibers have a dpf value of from 0.3 to 5 dpf.

### Claim 12 (depends on 1)

A nonwoven fabric according to claim 1, comprising a plurality of nonwoven layers that are bonded together.

### Claim 13 (depends on 1)

A nonwoven fabric according to claim 1, wherein said fibers comprise a propylene polymer composition comprises a combination of two or more propylene polymers.

### Claim 14 (depends on 1)

A nonwoven fabric according to claim 1, wherein said nonwoven fabric is a spunbonded nonwoven.

### Claim 15 (depends on 1)

A nonwoven fabric according to claim 1, wherein said nonwoven fabric is a meltblown nonwoven.

### Claim 16 (depends on 1)

A nonwoven fabric according to claim 1, comprising a laminate comprising a plurality of nonwovens each independently selected from spunbonded nonwovens and meltblown nonwovens.

### Claim 17 (depends on 1)

A nonwoven fabric according to claim 1, wherein the propylene polymer composition comprises a propylene polymer having an Mw/Mn of 1 to 7, and/or an Mz/Mw of 1.5 to 2.5.

### Claim 18

A nonwoven fabric having a fabric basis weight of not more than 15 gsm and comprising polypropylene fibers having a dpf value of 0.3 to 5 dpf, wherein said polypropylene fibers comprise a propylene polymer composition comprising at least 50 mol % propylene, said polymer composition having:
a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of about 10 to 25 dg/min
b) a dimensionless Stress Ratio/Loss Tangent Index R2 [defined by Eq. (8)] at 190° C. from 1.5 to 30
c) an onset temperature of crystallization under flow, Tc,rheol, (as determined by SAOS rheology, 1° C./min as described below, where said polymer has 0 wt % nucleating agent present), of at least about 123° C. and
d) an average meso run length determined by 13C NMR of at least about 55 or higher.

### Claim 19 (depends on 18)

A nonwoven fabric according to claim 18, said nonwoven fabric being obtainable by spun-bonding with a production line speed of at least 400 m/min.

### Claim 20 (depends on 18)

A nonwoven fabric according to claim 18, wherein said fabric has a fabric tensile anisotropy as defined herein of less than 3.0 when produced at a production line speed of 900 m/min.

### Claim 21

A nonwoven fabric having a fabric basis weight of not more than 15 gsm and comprising polypropylene fibers having a dpf value of 0.3 to 5 dpf, wherein:
said nonwoven fabric is obtainable by spun-bonding with a production line speed of at least 400 m/min;
said polypropylene fibers are composed of a propylene polymer composition comprising at least 50 mol % propylene, said polymer composition having:
a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of about 10 to 25 dg/min
b) a dimensionless Stress Ratio/Loss Tangent Index R2 [defined by Eq. (8)] at 190° C. from 1.5 to 30
c) an onset temperature of crystallization under flow, Tc,rheol, (as determined by SAOS rheology, 1° C./min as described below, where said polymer has 0 wt % nucleating agent present), of at least about 123° C. and
d) an average meso run length determined by 13C NMR of at least about 55 or higher; and
said fabric has a ratio of CD elongation to CD peak Strength of 40 or more (when measured at speed of 200 mm/min, 100 mm gauge length) and a CD strength of 1.0 N/5 cm/gsm or more (when measured at speed of 100 mm/min, 200 mm gauge length).

### Claim 22 (depends on 21)

A nonwoven fabric according to claim 21 having a CD strength of Y N/5 cm/gsm or more, where Y=−0.0005(X)+1.41 (preferably 1.45, preferably 1.5, preferably 1.6), where X is the production line speed of fabric and is at least 400 m/min.

### Claim 23 (depends on 21)

A nonwoven fabric according to claim 21, obtainable by spunbonding with a line speed of at least 600 m/min.

### Claim 24 (depends on 21)

A laminate fabric comprising a nonwoven fabric according to claim 21 and at least one further fabric layer.

### Claim 25

A polypropylene fiber comprising a propylene polymer comprising at least 50 mol % propylene, said polymer having:
a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of about 10 dg/min to about 21.5 dg/min;
b) a dimensionless Stress Ratio/Loss Tangent Index R2 [defined by Eq. (8) herein] at 190° C. from about 1.5 to about 28;
c) an onset temperature of crystallization under flow, Tc,rheol, (as determined by SAOS rheology, 1° C./min as described herein, where said polymer has 0 wt % nucleating agent present), of at least about 131° C.; and
d) an average meso run length determined by 13C NMR of at least about 97 or higher.

### Claim 26 (depends on 25)

A fiber according to claim 25, having a dpf value of from 0.3 to 5 dpf.

### Claim 27 (depends on 25)

A fiber according to claim 25, wherein the fiber is a yarn comprising a plurality of polypropylene filaments having a dpf value of from 0.3 to 5 dpf.

### Claim 28 (depends on 25)

A fiber according to claim 25, wherein the fiber is a monofilament of 0.3 to 5 denier.

### Claim 29 (depends on 25)

Staple fiber comprising a multiplicity of fibers according to claim 25.

### Claim 30 (depends on 25)

An article comprising a multiplicity of fibers according to claim 25.

### Claim 31 (depends on 1)

An article comprising a one or more nonwoven fabrics according to claim 1.

### Claim 32 (depends on 1)

A diaper comprising one or more nonwoven fabrics according to claim 1.