US6468451B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a fibrillated article
Assignee: 3M Innovative Properties Co
•
Filing: 2000-06-23
•
Granted: 2002-10-22
•
Expires: 2020-06-23
Abstract
Abstract A fibrillated foamed article and process for producing the same is described. The fibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as a diffuse reflector for use in optical applications such as computer displays and as reinforcement fibers for polymers or cast building materials such as concrete.
Inventors
- 👤 Mario A. Perez
- 👤 Christopher K. Haas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:48
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/36; D; D04; D04H; D04H11/00; D04H11/08; D04H13/00; D04H13/02; C08J2323/00; C08J2323/02; C08J2323/10
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
53 words
A process for preparing a fibrillated article comprising the step of fibrillating an oriented, high melt strength polypropylene foam wherein said high melt-strength polypropylene comprises homo- and copolymers containing 50 weight percent or more propylene monomer units, and having a melt strength in the range of 25 to 60 cN at 190° C.
Claim 2
Dependent Claim
53 words
A process for preparing a fibrillated article comprising the step of fibrillating an oriented, high melt strength polypropylene foam wherein said high melt-strength polypropylene comprises homo- and copolymers containing 50 weight percent or more propylene monomer units, and having a melt strength in the range of 25 to 60 cN at 190° C.
Claim 3
Dependent Claim
41 words
The process of claim 1 wherein said oriented foam is prepared by the steps of extruding a mixture comprising a high melt-strength polypropylene and a blowing agent to produce a foam, and orienting the extruded foam in at least one direction.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein said foam is oriented under conditions such that the density of the extruded foam is decreased.
Claim 5
Dependent Claim
24 words
The process of claim 3 wherein said orientation is at or above the alpha transition temperature and below the melt temperature of the polypropylene.
Claim 6
Dependent Claim
10 words
The process of claim 1 wherein said orientation is uniaxial.
Claim 7
Dependent Claim
10 words
The process of claim 1 wherein said orientation is biaxial.
Claim 8
Dependent Claim
11 words
The process of claim 6 wherein said orientation is simultaneously biaxial.
Claim 9
Dependent Claim
26 words
The process of claim 1 wherein the melt strength of said high melt strength polypropylene is the range of 30 to 55 cN at 190° C.
Claim 10
Dependent Claim
33 words
The process of claim 1 wherein said polypropylene copolymers are selected from random, block, and grafted copolymer of propylene and an α-olefin selected from the group consisting of C3-C8 α-olefins and C4-C10 dienes.
Claim 11
Dependent Claim
47 words
The process of claim 2 wherein said mixture comprises a blowing agent and a blend of high melt strength polypropylene and at least one of: polyethylene, fluropolymers, poly(1-butene), ethylene/acrylic acid copolymer, ethylene/vinyl acetate copolymer, ethylene/propylene copolymer, styrene/butadiene copolymer, ethylene/styrene copolymer ethylene/ethyl acrylate copolymer, ionomers and thermoplastic elastomers.
Claim 12
Dependent Claim
18 words
The process of claim 1 wherein said extruding step comprises extruding said mixture at a pressure ≧2500 psi.
Claim 13
Dependent Claim
14 words
The process of claim 4 wherein said orientation is at least 3×total draw ratio.
Claim 14
Dependent Claim
16 words
The process of claim 5 wherein said orientation is at least 3 to 50×total draw ratio.
Claim 15
Dependent Claim
19 words
The process of claim 2 wherein said blowing agent is selected from physical blowing agents and chemical blowing agents.
Claim 16
Dependent Claim
30 words
The process of claim 2 wherein the mixture is at a temperature and pressure sufficient to form a melt mixture wherein the blowing agent is uniformly distributed throughout the polypropylene.
Claim 17
Dependent Claim
19 words
The process of claim 15 wherein the temperature is sufficient to activate said chemical blowing agent prior to extrusion.
Claim 18
Dependent Claim
45 words
The process of claim 15 wherein the melt mixture is cooled immediately prior to extrusion to an exit temperature less than or equal to 30° C. above the melting temperature of the polypropylene and at a pressure sufficient to keep the blowing agent in solution.
Claim 19
Dependent Claim
30 words
The process of claim 15 wherein the melt mixture is extruded though a die, exposing the melt mixture to atmospheric temperature and pressure, thereby causing the melt mixture to foam.
Claim 20
Dependent Claim
17 words
The process of claim 1 wherein said foam comprises 70% or greater closed cells prior to orientation.
Claim 21
Dependent Claim
21 words
The process of claim 1 wherein said foam, prior to orientation, has an average cell size of 50 micrometers or less.
Claim 22
Dependent Claim
24 words
The process of claim 1 wherein said step of fibrillating said oriented, high melt strength polypropylene foam impart a schistose surface to said foam.
Claim 23
Dependent Claim
24 words
The process of claim 1 wherein said step of fibrillating said oriented, high melt strength polypropylene foam imparts a fibrous surface to said foam.
Claim 24
Dependent Claim
20 words
The process of claim 1 wherein said high melt strength polypropylene comprises 70 weight percent or more propylene monomer units.
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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) | 2005-10-21 | 2006-04-22 | 2006-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-10-21 | 2010-04-22 | 2010-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-10-21 | 2014-04-22 | 2014-10-22 | $7700.00 | Window Closed / Lapsed |