Stock material or miscellaneous articles – Composite – Of polycarbonate
Reexamination Certificate
1999-06-10
2002-02-12
Chen, Vivian (Department: 1773)
Stock material or miscellaneous articles
Composite
Of polycarbonate
C428S421000, C428S422000, C428S424200, C428S424400, C428S424600, C428S474700, C428S474900, C428S475800, C428S476100, C428S476300, C428S483000, C428S515000, C428S516000, C428S520000, C428S522000, C428S523000
Reexamination Certificate
active
06346328
ABSTRACT:
BACKGROUND OF THE INVENTION
Fluoropolymers, or fluorine-containing polymers, are a commercially important class of materials. Fluoropolymers include, for example, uncrosslinked and crosslinked fluorocarbon elastomers and semi-crystalline or glassy fluorocarbon plastics. Fluorocarbon plastics (or fluoroplastics) are generally of high thermal stability and are particularly useful at high temperatures. They also exhibit extreme toughness and flexibility at very low temperatures. Many of these fluoroplastics are almost totally insoluble in a wide variety of solvents and, thus, are generally chemically resistant. Some have extremely low dielectric loss and high dielectric strength, and many have unique nonadhesive and low-friction properties. See, for example, F. W. Billmeyer,
Textbook of Polymer Science
, 3
rd
ed., pp. 398-403, John Wiley & Sons, New York (1984).
Fluorocarbon elastomers, particularly the copolymers of vinylidene fluoride with other ethylenically unsaturated halogenated monomers, such as hexafluoropropylene, have particular utility in high temperature applications, such as seals, gaskets, and linings. See, for example, R. A. Brullo, “Fluoroelastomer Rubber for Automotive Applications,”
Automotive Elastomer
&
Design
, June 1985, “Fluoroelastomer Seal Up Automotive Future,”
Materials Engineering
, October 1988, and W. M. Grootaert, et al., “Fluorocarbon Elastomers,” Kirk-Othmer,
Encyclopedia of Chemical Technology
, Vol. 8, pp. 990-1005 (4
th
ed., John Wiley & Sons, 1993).
Fluoroplastics, particularly polychlorotrifluoroethylene, polytetrafluoroethylene, copolymers of tetrafluoroethylene and hexafluoropropylene, and poly(vinylidene fluoride), have numerous electrical, mechanical, and chemical applications. Fluoroplastics are useful, for example, in wire coatings, electrical components, seals, solid and lined pipes, and piezoelectric detectors. See, for example, “Organic Fluorine Compounds,” Kirk-Othmer,
Encyclopedia
of Chemical Technology, Vol. 11, pp., 20, 21, 32, 33, 40, 41, 50, 52, 62, 70, 71 (John Wiley & Sons, 1980).
In the automotive industry, for example, increased concern with evaporative fuel standards has led to the need for fuel system components that have improved barrier properties. This helps reduce the permeation of fuel vapors through automotive elements such as fuel filler lines, fuel supply lines, fuel tanks, and other elements of an automobile fuel system. Multi-layer tubing and other articles containing a fluorinated layer have been used in such automotive elements to provide a chemically resistant vapor barrier. Multi-layer articles are also useful in a number of other industries including, for example, the chemical processing and/or handling industries, and the electrical and electronics industries. Such multi-layer articles can include one or more other layers that can add strength, rigidity, or other mechanical properties.
Multi-layer compositions comprising a fluorinated polymer layer and a polyamide or polyolefin layer are known. See, for example, U.S. Pat. No. 4,933,090 (Krevor) which discloses laminate tubular articles that can include layers of fluorocarbon elastomers, and International Publication No. WO 93/14933 (LaCourt) which discloses a laminar film structure that includes a polyimide and a fluoropolymer.
To be useful, these multi-layer articles should not delaminate during use. That is, the bond strength between the layers of the multi-layer article should be sufficient to prevent the layers from separating. A variety of methods have been employed to increase the bond strength between a layer comprising a fluoropolymer and a layer comprising a substantially non-fluorinated polymer. For example, a layer of adhesive can be added between the two layers. However, the adhesive used must not limit the performance of the multi-layer article.
As an alternative to, or in addition to, adhesives, surface treatment of one or both of the layers has been used to increase the adhesive bond strength between the layers. For example, layers comprising a fluoropolymer have been treated with a charged gaseous atmosphere followed by application of a layer of thermoplastic polyamide.
In another approach, the adhesion between a substantially non-fluorinated polymer and a fluoropolymer, wherein the fluoropolymer is derived from vinylidene fluoride (VDF), and optionally hexafluoropropylene (HFP), has been found to increase upon exposure of the fluoropolymer to a primary or secondary amine compound. An example includes providing a layer comprising a fluoropolymer comprising interpolymerized units derived from vinylidene fluoride, a layer of a melt-processable, substantially non-fluorinated polymer, and a melt-processable aliphatic di- or polyamine of less than 1,000 molecular weight. See, for example, U.S. Pat. No. 5,658,670.
There are however certain circumstances where the production of such amine containing compounds or their subsequent use is problematic. What is needed is an alternative method for improving the adhesion between fluoropolymers and substantially non-fluorinated materials. This invention provides such a method.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a method of adhering or bonding a substantially non-fluorinated thermoplastic polymer to a fluoropolymer. In another aspect, the present invention provides a composite article comprising a substantially non-fluorinated thermoplastic polymer adhered to a fluoropolymer. In still another aspect, the present invention provides a multilayer article comprising a fluoropolymer adhered to a first surface of the substantially non-fluorinated thermoplastic polymer and a second polymer adhered to a second surface of the substantially non-fluorinated thermoplastic polymer. When the thermoplastic polymer layer comprises a functionalized polyolefin, (i.e., a polyolefin derived from the reaction of a functionalized olefin with a bisphenol), there is substantially no organo-onium present.
The method of the invention comprises the steps of
(a) providing (i) a substantially non-fluorinated thermoplastic polymer having one or more pendant phenolic groups, and optionally one or more primary or secondary pendant amine groups thereon, (ii) a base, and (iii) a fluoropolymer,
(b) at least partially reacting the phenolic group or groups with the base, to form a modified substantially non-fluorinated thermoplastic polymer,
(c) forming a composite article comprising the fluoropolymer in contact with a first surface of the modified thermoplastic polymer, and
(d) subjecting the composite article to pressure and/or temperature conditions adequate to bond the modified thermoplastic polymer to the fluoropolymer. When the thermoplastic polymer of step “a” is an olefin derived from the reaction of a functionalized olefin with a bisphenol, there is substantially no organo-onium present during the process.
The composite article of the invention comprises a fluoropolymer layer bonded to a layer of the modified thermoplastic polymer. The composite article may further have a second substantially non-fluorinated thermoplastic polymer bonded to the modified thermoplastic polymer. The second thermoplastic polymer may be the same as, or different than, the modified thermoplastic polymer.
The embodiments of the invention are useful in providing a wide variety of shaped composite articles such as sheets and films, containers, hoses, tubes and the like. The articles so provided are especially useful wherever chemical resistance and/or barrier properties are necessary. Examples of specific uses for the composite structures of the invention include their use in rigid and flexible retroreflective sheets, adhesive articles such as adhesive tapes, paint replacement films, drag reduction films, fuel line and filler neck hoses, hydraulic fluid hoses, exhaust handling hoses, fuel tanks, and the like. The composite articles of the invention are also useful in chemical handling and processing applications, and as wire and cable coatings or jackets.
As used herein, a thermoplastic polymer, whether fluorinate
Blong Thomas J.
Kolb Robert E.
Molnar Attila A.
Parsonage Edward E.
Chen Vivian
Dyneon LLC
Harts Dean M.
Lilly James V.
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