US5362562A
Expired / Lapsed
US
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Crimped acrylic fibers having improved thixotropic performance
Assignee: Sterling Chemicals International Inc
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Filing: 1993-03-12
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Granted: 1994-11-08
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Expires: 2013-03-12
Abstract
Abstract Crimped acrylic fibers with a small diameter, a minimum aspect ratio in the 20-50 range, and having a crimp of greater than about 10% so as to enhance the viscosity of polymers, resistance to gravity-induced slumping when applied to vertical surfaces, and mix stability, as well as provide matrix reinforcement and toughness, are adapted to act as improved physical thixotropes in adhesives, sealants, coatings, paints, grouts, building materials and the like.
Inventors
- 👤 Robert E. Evans
- 👤 Arutun Maranci
- 👤 Stanley S. Kaminski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:05
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; C09; C09K; C09K3/00; C09K3/10; C09K3/1025; C09K3/1028; D01F6/00; D01F6/02; D01F6/18; C09K2200/00; C09K2200/02; C09K2200/0239; C09K2200/04; C09K2200/0447; C09K2200/06; C09K2200/068; C09K2200/0682; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2904; Y10T428/2913; Y10T428/2922; Y10T428/2933; Y10T428/2964; Y10T428/2967; Y10T428/2973; Y10T428/298
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
41 words
A physical thixotrope comprising crimped acrylic fibers having a maximum diameter of less than 100 micrometers, a minimum length in the range of 0.5-3 mm, a minimum aspect ratio (L/D) in the 20-50 range and a crimp of greater than 3%.
Claim 2
Dependent Claim
41 words
A physical thixotrope comprising crimped acrylic fibers having a maximum diameter of less than 100 micrometers, a minimum length in the range of 0.5-3 mm, a minimum aspect ratio (L/D) in the 20-50 range and a crimp of greater than 3%.
Claim 3
Dependent Claim
11 words
Crimped acrylic fibers as defined in claim 1 which are non-fibrillated.
Claim 4
Dependent Claim
11 words
Crimped acrylic fibers as defined in claim 1 which are fibrillated.
Claim 5
Dependent Claim
21 words
Crimped acrylic fibers as defined in claim 1 comprised of a polymer containing acrylonitrile in a quantity more than 35 wt%.
Claim 6
Dependent Claim
22 words
Crimped acrylic fibers as defined in claim 1 comprised of a polymer containing acrylonitrile in a quantity more than 85 wt %.
Claim 7
Dependent Claim
13 words
Crimped acrylic fibers as defined in claim 1 which have a uniform length.
Claim 8
Dependent Claim
14 words
Crimped acrylic fibers as defined in claim 1 which comprise a mixture of lengths.
Claim 9
Dependent Claim
27 words
Crimped acrylic fibers as defined in claim 1 having an average diameter in the range of about 2-15 micrometers, and having a crimp of greater than 5%.
Claim 10
Dependent Claim
29 words
Crimped acrylic fibers as defined in claim 8 having an average diameter in the range of up to about 8 micrometers, and having a crimp of greater than 10%.
Claim 11
Dependent Claim
18 words
Crimped acrylic fibers as defined in claim 1 having an aspect ratio (L/D) of greater than about 100.
Claim 12
Dependent Claim
17 words
Crimped acrylic fibers as defined in claim 1 having a modulus of greater than about 0.8 msi.
Claim 13
Dependent Claim
20 words
Crimped acrylic fibers as defined in claim 1 having a molecular weight of greater than about 100,000 (M K ).
Claim 14
Dependent Claim
12 words
Crimped acrylic fibers as defined in claim 1 having a finished surface.
Claim 15
Dependent Claim
14 words
Crimped acrylic fibers as defined in claim 1 having a cross-section which is non-round.
Claim 16
Dependent Claim
13 words
Crimped acrylic fibers as defined in claim 1 which are pre-oxidized and thermally-stable.
Claim 17
Dependent Claim
121 words
A thixotropic agent produced from crimped monocomponent or bicomponent fibers of a polymer containing acrylonitrile in a quantity more than 35 wt %, said fibers having a fiber diameter less than 100 micrometers, a fiber length greater than 0.5 mm, a minimum aspect ratio in the range of 20-50, and being crimped to greater than about 5% so as (i) to provide improved viscosity to a matrix polymer, (ii) to provide a composite of a polymer and said thixotropic agent having greater resistance to slumping than the resistance to slumping of a composite comprising said polymer and a thixotropic agent comprising the corresponding uncrimped, non-texturized fibers, and (iii) to provide a composite having a greater resistance to fiber-matrix separation or dewetting.
Claim 18
Dependent Claim
121 words
A thixotropic agent produced from crimped monocomponent or bicomponent fibers of a polymer containing acrylonitrile in a quantity more than 35 wt %, said fibers having a fiber diameter less than 100 micrometers, a fiber length greater than 0.5 mm, a minimum aspect ratio in the range of 20-50, and being crimped to greater than about 5% so as (i) to provide improved viscosity to a matrix polymer, (ii) to provide a composite of a polymer and said thixotropic agent having greater resistance to slumping than the resistance to slumping of a composite comprising said polymer and a thixotropic agent comprising the corresponding uncrimped, non-texturized fibers, and (iii) to provide a composite having a greater resistance to fiber-matrix separation or dewetting.
Claim 19
Dependent Claim
29 words
A thixotropic agent as defined in claim 16, wherein said crimped acrylic fibers are comprised of a polymer containing acrylonitrile in a quantity of more than 85 wt %.
Claim 20
Dependent Claim
17 words
A thixotropic agent as defined in claim 16, wherein said crimped acrylic fibers have a uniform length.
Claim 21
Dependent Claim
18 words
A thixotropic agent as defined in claim 16, wherein said crimped acrylic fibers comprise a mixture of lengths.
Claim 22
Dependent Claim
32 words
A thixotropic agent as defined in claim 16, wherein said crimped acrylic fibers have an average diameter in the range of about 2-15 micrometers, and have a crimp of greater than 10%.
Claim 23
Dependent Claim
34 words
A thixotropic agent as defined in claim 20, wherein said crimped acrylic fibers have an average diameter in the range of up to about 8 micrometers, and have a crimp of greater than 20%.
Claim 24
Dependent Claim
23 words
A thixotropic agent as defined in claim 16, wherein said crimped acrylic fibers have an aspect ratio (L/D) of greater than about 100.
Claim 25
Dependent Claim
32 words
A thixotropic agent as defined in claim 16, wherein said crimped acrylic fibers have an average diameter in the range of about 5-15 micrometers, and have a crimp of greater than 10%.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-11-07 | 1998-05-09 | 1998-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-07 | 2002-05-09 | 2002-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-07 | 2006-05-09 | 2006-11-08 | $7700.00 | Window Closed / Lapsed |