U.S. patent application number 09/904927 was filed with the patent office on 2001-12-06 for compositions for fluoropolymer bonding to non-fluorinated polymers.
This patent application is currently assigned to Minnesota Mining and Manufacturing Company, Minnesota Mining and Manufacturing Company. Invention is credited to Jing, Naiyong.
Application Number | 20010049408 09/904927 |
Document ID | / |
Family ID | 22990723 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010049408 |
Kind Code |
A1 |
Jing, Naiyong |
December 6, 2001 |
Compositions for fluoropolymer bonding to non-fluorinated
polymers
Abstract
The invention relates to compositions useful for bonding
fluoropolymer to substantially non-fluorinated polymer. The
compositions of the invention comprise a substantially
non-fluorinated polymer or a mixture of said polymers, a di- or
polyamine, preferably, an aliphatic diamine, and an onium catalyst,
preferably, a phosphonium salt.
Inventors: |
Jing, Naiyong; (Woodbury,
MN) |
Correspondence
Address: |
Office of Intellectual Property Counsel
3M Innovative Properties Company
PO Box 33427
St. Paul
MN
55133-3427
US
|
Assignee: |
Minnesota Mining and Manufacturing
Company
|
Family ID: |
22990723 |
Appl. No.: |
09/904927 |
Filed: |
July 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09904927 |
Jul 13, 2001 |
|
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09260813 |
Mar 2, 1999 |
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Current U.S.
Class: |
524/252 ;
428/421; 428/422 |
Current CPC
Class: |
C08J 5/124 20130101;
C08K 5/50 20130101; Y10T 428/31928 20150401; B32B 37/153 20130101;
B32B 2597/00 20130101; Y10T 428/31935 20150401; B32B 27/08
20130101; B32B 2439/00 20130101; Y10T 428/3154 20150401; C08J
2327/12 20130101; B32B 27/304 20130101; C08K 5/17 20130101; B32B
2327/06 20130101; Y10T 428/1379 20150115; Y10T 428/31544
20150401 |
Class at
Publication: |
524/252 ;
428/421; 428/422 |
International
Class: |
B32B 027/00 |
Claims
What is claimed is:
1. A composition comprising a mixture of: a) melt processable
substantially non-fluorinated polymer; b) primary or secondary di-
or polyamine; and c) organo-onium catalyst.
2. The composition of claim 1 wherein the substantially
non-fluorinated polymer is polyamide, polyurethane, polyolefin,
copolymers of polyolefins, functionalized polyolefins, or
combinations thereof.
3. The composition of claim 2 wherein the polyolefin is a
homopolymer or a copolymer comprising polyethylene, polypropylene,
acrylic monomers, maleic anhydride, vinyl acetate, or combinations
thereof.
4. The composition of claim 1 wherein the amount of said polyamine
in the composition ranges from about 0.3 to about 10 parts by
weight.
5. The composition of claim 1 wherein the di- or polyamine is an
alkylene amine.
6. The composition of claim 1 wherein the organo-onium catalyst is
a phosphonium.
7. An article comprising: a) a first layer comprising
fluoropolymer; and b) a second layer bonded to the first layer
comprising a mixture of: 1) melt processable substantially
non-fluorinated polymer, 2) primary or secondary di- or polyamine,
and 3) onium catalyst.
8. The article of claim 7 wherein the fluoropolymer is
fluoroplastic or is a fluoroelastomer.
9. The article of claim 7 wherein the fluoropolymer comprises
interpolymerized units derived from vinylidene fluoride or vinyl
fluoride.
10. The article of claim 7 wherein the fluoropolymer is a
homopolymer of vinylidene fluoride or vinyl fluoride or is a
copolymer or terpolymer derived from vinylidene fluoride and one or
more monomers selected from vinyl fluoride, tetrafluoroethylene,
and hexafluoropropylene.
11. The article of claim 7 wherein the fluoropolymer comprises
interpolymerized units derived from monomers comprising one or more
hexafluoropropylene, tetrafluoroethylene, and
chlorotrifluoroethylene monomer and one or more non-fluorinated
olefinically- unsaturated monomers.
12. The article of claim 7 wherein the fluoropolymer comprises a
mixture of a fluoropolymer and a polyolefin.
13. The composition of claim 1 wherein the substantially
non-fluorinated polymer is selected from one or more of polyamides,
polyurethanes, polyolefins, copolymers of polyolefins,
functionalized polyolefins, or combinations thereof.
14. The composition of claim 2 wherein the polyolefin is a
homopolymer or a copolymer comprising polyethylene, polypropylene,
acrylic monomers, maleic anhydride, vinyl acetate, or combinations
thereof.
15. The composition of claim 1 wherein the amount of said polyamine
in the composition ranges from about 0.3 to about 10 parts by
weight.
16. The article of claim 7 wherein the di- or polyamine is an
alkylene amine.
17. The article of claim 7 wherein the organo-onium catalyst is a
phosphonium.
18. A method of bonding fluoropolymer to substantially
non-fluorinated polymer comprising the steps of: a) providing a
bonding composition comprising a mixture of: 1) melt processable
substantially non-fluorinated polymer, 2) primary or secondary di-
or polyamine, and 3) onium catalyst; b) providing fluoropolymer;
and c) forming a multi-layer article by contacting a first layer
comprising the substantially non-fluorinated polymer with a second
layer comprising the fluoropolymer.
19. The method of claim 18 wherein the means of contacting the
first and second layer is lamination or coextrusion.
20. The composition of claim 2 wherein the functionalized
polyolefins have the functionality of carboxyl, anhydride, imide,
or combinations thereof.
21. The article of claim 7 wherein the second layer further
comprises a tackifier.
22. The article of claim 7 further comprising transparent
microspheres.
23. The article of claim 7 wherein said article is a hose,
container, or film.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to compositions for bonding
fluoropolymers to non-fluorinated polymers, multilayer adhesive
articles comprising a fluoropolymer and a substantially
non-fluorinated material, and methods of making such articles.
[0002] Fluorine-containing polymers (that is, fluoropolymers or
fluorinated polymers), are an important class of polymers that
include, for example, fluoroelastomers and fluoroplastics. Among
this broad polymer class are polymers of high thermal stability,
polymers of extreme toughness, and polymers exhibiting usefulness
along a broad spectrum of temperatures. Many of these polymers also
are almost totally insoluble in a wide variety of organic solvents;
see, for example, F. W. Billmeyer, Textbook of Polymer Science, 3rd
ed., pp. 398-403, John Wiley & Sons, New York (1984).
[0003] Fluoroelastomers, particularly the copolymers of vinylidene
fluoride with other ethylenically unsaturated halogenated monomers
such as hexafluoropropylene find particular utility in high
temperature applications, such as in seal gaskets and linings. See,
for example, Brullo, R. A., "Fluoroelastomer Rubber for Automotive
Applications," Automotive Elastomer & Design, June 1985;
"Fluoroelastomers Seal Up Automotive Future," Materials
Engineering, October 1988; and "Fluorinated Elastomers,"
Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Vol. 8,
pp. 500-515, John Wiley & Sons, New York (1979).
[0004] 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, as wire coatings, electrical components,
seals, and in 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, 48, 50, 52, 62, 70, and 71, John Wiley & Sons, New York
(1980).
[0005] Multi-layer constructions containing a fluorinated polymer
enjoy wide industrial application. Multi-layer fluoropolymer
constructions find utility in, for example, fuel line hoses and
related containers and in retroreflective sheeting materials.
Increased concerns with evaporative fuel standards give rise to a
need for fuel system components that have increased barrier
properties to minimize the permeation of fuel vapors through
automotive components including fuel filler lines, fuel supply
lines, fuel tanks, and other components of the engine's fuel system
control system. Various types of constructions have been proposed
to address these concerns. In general, the most successful of these
are co-extruded multi-layer constructions.
[0006] Multi-layer compositions comprising a fluorinated polymer
layer and a polyamide or polyolefin layer are known. U.S. Pat. No.
4,933,090 (Krevor), for example, discloses laminate tubular
articles that can comprise layers of fluorocarbon elastomers, and
PCT Publication WO 93/1493 discloses a laminar film structure
comprising a polyimide and a fluoropolymer. The use of fluorinated
polymers in retroreflective sheeting also is known. U.S. Pat. Nos.
3,551,025 (Bingham et al.) and 4,348,312 (Tung), for example,
describe products that include glass microspheres, and PCT
Publications WO 95/11466 and WO 95/11464 describe products
containing retroreflective cube corner arrays.
[0007] A variety of methods can be used to increase the adhesion
between a fluorinated polymer layer and a polyamide or polyolefin
layer. An adhesive layer can, for example, be added between the two
polymer layers. U.S. Pat. No. 5,047,287 (Horiuchi et al.) discloses
a diaphragm, suitable for use in automotive applications, that
comprises a base fabric having bonded to at least one surface a
fluororubber layer by an adhesive that includes an
acrylonitrile-butadiene or acrylonitrile-isoprene rubber having an
amino group.
[0008] Surface treatment of one or both of the layers sometimes is
employed to aid bonding. Some, for example, have taught treating
fluoropolymer layers with charged gaseous atmosphere and applying
subsequently a layer of a second material, for example a
thermoplastic polyamide.
[0009] Blends of the fluoropolymer and the dissimilar layer
themselves are in some cases employed as an intermediate layer to
help bond the two layers together. European Patent Application No.
0523644 (Kawashima et al.) discloses a plastic laminate having a
polyamide resin surface layer and a fluororesin surface layer. The
reference recognizes the difficulties encountered when making
laminates having a polyamide layer and a fluororesin layer because
of the incompatibility of the two materials. The laminate of the
reference is prepared by use of an intermediate layer composed of a
blend of an aliphatic polyamide resin with a fluorine-containing
graft copolymer.
SUMMARY OF THE INVENTION
[0010] In one aspect, the invention provides a composition
comprising a mixture of melt processable substantially
non-fluorinated polymer, primary or secondary di- or polyamine, and
onium catalyst.
[0011] In another aspect, the invention provides an article
comprising a first layer comprising fluoropolymer, and a second
layer bonded to the first layer comprising a mixture of: melt
processable substantially non-fluorinated polymer, primary or
secondary di- or polyamine, and onium catalyst. In another aspect,
the invention provides a method of bonding fluoropolymer to
substantially non-fluorinated polymer comprising the steps of:
providing a bonding composition comprising a mixture of melt
processable substantially non-fluorinated polymer, primary or
secondary di- or polyamine, and onium catalyst; providing
fluoropolymer; and forming a multi-layer article by contacting a
first layer comprising the substantially non-fluorinated polymer
with a second layer comprising the fluoropolymer.
[0012] Some of the advantages of the articles of the invention
include lower cost, chemical resistance, and resistance to marking
or dirt and grime, for example for signage. The compositions of the
invention provide improved adhesion to fluoropolymers while using
smaller quantities of polyamines than compositions not containing
an onium catalyst.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Fluoropolymer materials useful in the present invention
include those fluoropolymers broadly categorized structurally into
three basic classes. A first class includes those fluorinated
polymers, copolymers, terpolymers, etc., comprising
interpolymerized units derived from vinylidene fluoride or vinyl
fluoride (sometimes referred to as "VF.sub.2" or "VDF" and VF
respectively). Preferably fluoropolymer materials of this first
class comprise at least 3 percent by weight of interpolymerized
units derived from VF.sub.2 or VF. Such polymers may be
homopolymers of VF.sub.2 or VF or copolymers of VF.sub.2 or VF and
other ethylenically unsaturated monomers. Copolymers of VF.sub.2 or
VF and other ethylenically unsaturated monomers are examples of
fluoropolymers.
[0014] VF.sub.2 and VF-containing polymers and copolymers can be
made by well-known conventional means, for example, by free-radical
polymerization of VF.sub.2 with or without other
ethylenically-unsaturate- d monomers. The preparation of colloidal
aqueous dispersions of such polymers and copolymers is described,
for example, in U.S. Pat. No. 4,335,238 (Moore et al.). It follows
the customary process for copolymerizing fluorinated olefins in
colloidal aqueous dispersions, which is carried out in the presence
of water-soluble initiators that produce free radicals, such as,
for example, ammonium or alkali metal persulfates or alkali metal
permanganates, and in the presence of emulsifiers, such as, in
particular, the ammonium or alkali metal salts of perfluorooctanoic
acid.
[0015] Useful fluorine-containing monomers for copolymerization
with VF.sub.2 or VF include hexafluoropropylene ("HFP"),
tetrafluoroethylene ("TFE"), chlorotrifluoroethylene ("CTFE"),
2-chloropentafluoro-propene, perfluoroalkyl vinyl ethers, for
example, CF.sub.3OCF.dbd.CF.sub.2 or
CF.sub.3CF.sub.2OCF.dbd.CF.sub.2, 1-hydropentafluoropropene,
2-hydropentafluoropropene, dichlorodifluoroethylene,
trifluoroethylene, 1,1-dichlorofluoroethylene, vinyl fluoride, and
perfluoro-1,3-dioxoles such as those described in U.S. Pat. No.
4,558,142 (Squire). Certain fluorine-containing di-olefins also are
useful, such as perfluorodiallylether and perfluoro-1,3-butadiene.
Said fluorine-containing monomer or monomers also may be
copolymerized with fluorine-free terminally unsaturated olefinic
co-monomers, for example, ethylene or propylene. Preferably at
least 50 percent by weight of all monomers in a polymerizable
mixture are fluorine-containing. Said fluorine-containing monomer
may also be copolymerized with iodine- or bromine-containing
cure-site monomers in order to prepare peroxide curable polymer.
Suitable cure-site monomers include terminally unsaturated
monoolefins of 2 to 4 carbon atoms such as bromodifluoroethylene,
bromotrifluoroethylene, iodotrifluoroethylene, and
4-bromo-3,3,4,4-tetrafluoro-butene-1.
[0016] Commercially available fluoropolymer materials of this first
class include, for example, THV 200 fluoropolymer (available from
Dyneon LLC of Saint Paul, Minn.), THV 500 fluoropolymer (available
from Dyneon LLC), KYNAR.TM. 740 fluoropolymer (available from Elf
Atochem North America, Inc., Glen Rock, N.J.), and FLUOREL.TM.
FC-2178 fluoropolymer (available from Dyneon LLC).
[0017] A second class of fluorinated material useful in the
practice of the invention broadly comprises those fluorinated
polymers, copolymers, terpolymers, etc., comprising
interpolymerized units derived from one or more of
hexafluoropropylene ("HFP") monomers, tetrafluoroethylene ("TFE")
monomers, chlorotrifluoroethylene monomers, and/or other
perhalogenated monomers and further derived from one or more
hydrogen-containing and/or non-fluorinated olefinically unsaturated
monomers. Useful olefinically unsaturated monomers include alkylene
monomers such as ethylene, propylene, 1-hydropentafluoropropene,
2-hydropentafluoropropene, etc.
[0018] Fluoropolymers of this second class can be prepared by
methods known in the fluoropolymer art. Such methods include, for
example, free-radical polymerization of hexafluoropropylene and/or
tetrafluoroethylene monomers with non-fluorinated
ethylenically-unsaturat- ed monomers. In general, the desired
olefinic monomers can be copolymerized in an aqueous colloidal
dispersion in the presence of water-soluble initiators which
produce free radicals such as ammonium or alkali metal persulfates
or alkali metal permanganates, and in the presence of emulsifiers
such as the ammonium or alkali metal salts of perfluorooctanoic
acid. See, for example, U.S. Pat. No. 4,335,238 (Moore et al.).
[0019] Representative of the fluoropolymer materials of the second
class are poly(ethylene-co-tetrafluoroethylene) (ETFE),
poly(tetrafluoroethylen- e-co-propylene),
poly(chlorotrifluoroethylene-co-ethylene) (ECTFE), and the
terpolymer
poly(ethylene-co-tetrafluoroethylene-co-hexafluoropropylen- e),
among others; all of which may be prepared by the above-described
known polymerization methods. Many useful fluoropolymer materials
also are available commercially, for example from Dyneon LLC, under
the trade designations HOSTAFLON.TM. X6810, and X6820; from Daikin
America, Inc., Decatur, triangular or trapezoidal section, more
suitable Glass Co., Charlotte, N.C., under the trade designations
AFLON.TM. COP C55A, C55AX, C88A; and from E.I. Du Pont de Nemours
and Company, Wilmington, Del., under the trade designations
TEFZEL.TM. 230 and 290.
[0020] A third class of fluorinated materials useful in the
practice of the invention broadly comprises blends of
fluoropolymers and polyolefins. Specific examples include blends of
PVDF and poly(methyl methacrylate) (PMMA) and blends of PVDF and
high vinyl acetate functionalized polyolefins.
[0021] Useful substantially non-fluorinated polymeric materials can
comprise any of a number of well known, substantially
non-fluorinated, hydrocarbon-based polymers, and mixtures thereof.
These polymeric materials also include such substantially
non-fluorinated polymeric materials considered to be pressure
sensitive adhesives. As used herein, the term "substantially
non-fluorinated" refers to polymers and polymeric materials having
fewer than 10 percent of their carbon-bonded hydrogen atoms
replaced with fluorine atoms. Preferably, the substantially
non-fluorinated polymer has fewer than 2 percent of its
carbon-bonded hydrogen atoms replaced with fluorine atoms, and more
preferably fewer than 1 percent of its carbon-bonded hydrogen atoms
are replaced with fluorine atoms. Preferred substantially
non-fluorinated polymers include thermoplastic polyamides,
polyurethanes, polyolefins, and copolymers of polyolefins.
[0022] Any melt-processable, carboxyl, carboxylate, anhydride,
amide, imide, hydroxyl, or oxycarbonyl functional polyolefin may be
used to make the substantially non-fluorinated polymeric material
of the invention. Polyolefins, e.g., polymers of ethylene,
propylene, acrylic monomers, other higher .alpha.-olefins, or other
ethylenically unsaturated monomers, may be functionalized by
homopolymerization of functional olefin monomers or by
co-polymerization of non-functional olefin monomers with functional
monomers, for example, with acrylic acid or maleic anhydride, vinyl
acetate, etc. Polyolefins may also be modified, or functionalized,
after polymerization, for example by grafting, by oxidation or by
forming ionomers. Such polymers and copolymers can be prepared by
conventional free-radical polymerization or catalysis of such
ethylenically unsaturated monomers. The degree of crystallinity of
the hydrocarbon polymer or copolymer can vary; the polymer may, for
example, be a semi-crystalline high density polyethylene or may be
an elastomeric copolymer of ethylene and propylene. Representative
of such substantially non-fluorinated polymer useful in the present
invention include, but are not limited to, co- and terpolymers of
the above-listed functional monomers with, for example, propylene,
ethylene, vinyl acetate, etc. The carboxyl, anhydride, or imide
functional polymers useful as the hydrocarbon polymer generally are
commercially available. Anhydride modified polyethylenes, for
example, are available commercially from the E.I. Du Pont de
Nemours and Company, under the trade designation "BYNEL," and
useful oxycarboxy functional polyethylenes are available under the
tradename "ELVAX" also available from E.I. Du Pont de Nemours and
Company.
[0023] Blends of one or more of the carboxyl, carboxylate,
anhydride, amide, imide, hydroxyl, or oxycarbonyl functional
polyolefins may be blended together or with other suitable polymers
to find utility in forming the substantially non-fluorinated layer
or layers of the invention.
[0024] Polyamides useful as the substantially non-fluorinated
polymer are generally commercially available. For example,
polyamides such as any of the well-known Nylons are available from
a number of sources. Particularly preferred polyamides are nylon 6,
nylon 6,6, nylon 11, or nylon 12. It should be noted that the
selection of a particular polyamide material should be based upon
the physical requirements of the particular application for the
resulting article. For example, nylon 6 and nylon 6,6 offer higher
heat resistant properties than nylon 11 or nylon 12; whereas nylon
11 and nylon 12 offer better chemical resistant properties. In
addition to those polyamide materials, other nylon material such as
nylon 6,12, nylon 6,9, nylon 4, nylon 4,2, nylon 4,6, nylon 7, and
nylon 8 may also be used. Ring containing polyamides, for example,
nylon 6,T and nylon 6,I, may also be used. Polyether containing
polyamides, such as PEBAX.TM. polyamines, may also be used.
[0025] Polyurethane polymers useful as the substantially
non-fluorinated polymer include aliphatic, cycloaliphatic,
aromatic, and polycyclic polyurethanes. These polyurethanes are
typically produced by reaction of a polyfunctional isocyanate with
a polyol according to well known reaction mechanisms. Useful
diiisocyanates for employment in the production of a polyurethane
include dicyclohexylmethane-4,4'-diisocyanat- e, isophorone
diisocyanate, 1,6-hexamethylene diisocyanate, cyclohexyl
diisocyanate, diphenylmethane diisocyanate. Combinations of one or
more polyfunctional isocyanates may also be used. Useful polyols
include polypentyleneadipate glycol, polytetramethylene ether
glycol, polyethylene glycol, polycaprolactone diol,
poly-1,2-butylene oxide glycol, and combinations thereof. Chain
extenders, such as butanediol or hexanediol, may also optionally be
used in the reaction. Commercially available urethane polymers
useful in the present invention include: PN-04 or 3429 from Morton
International, Inc., Seabrook, N.H., and X-4107 from B.F. Goodrich
Company, Cleveland, Ohio.
[0026] The term "di-, or polyamine," as used within this
description refers to organic compounds containing at least two
non-tertiary amine groups. Any primary or secondary amine may be
employed, although primary amines are preferred to secondary
amines. Aliphatic, aromatic, cycloaliphatic, and oligomeric di- and
polyamines all are considered useful in the practice of the
invention. Representative of the classes of useful di- or
polyamines are 4,4'-methylene dianiline,
3,9-bis-(3-aminopropyl)-2,4,8,10-tetroxaspiro [5,5]undecane, and
polyoxyethylenediamine. Many di- and polyamines, such as those just
named, are available commercially, for example, under the trade
designation "JEFFAMINES" (available from Texaco Chemical Company,
Houston, Tex.). The most preferred di- or polyamines include
aliphatic diamines or aliphatic di- or polyamines and more
specifically two primary amino groups, such as hexamethylene
diamine, dodecanediamine, and
2,4,8,10-tetraoxaspiro[5,5]undecane-(3,9-dipropanamine).
[0027] The di- or polyamine can be of any molecular weight that
when used in accordance with the present description will impart
adhesive bond strength between a fluoropolymer and a substantially
non-fluorinated polymeric material. As an example, the di- or
polyamine may have a weight average molecular weight of below
5,000, more preferably below 2,000, or 1,000, as measured by mass
spectroscopy or gel permeation chromatography (GPC).
[0028] Generally, the amount of diamine used in the compositions of
the invention range from about 0.3 to about 10 parts by weight.
[0029] The compositions of the invention include an organo-onium
catalyst. Any among a large class of organo-onium compounds that
are stable in the compositions of the invention are useful for
incorporation into the substantially non-fluorinated polymeric
material. As is known in the art, an organo-onium is the conjugate
acid of a Lewis base (for example phosphine, amine, and a sulfide)
and can be formed by reacting said Lewis base with a suitable
alkylating agent (for example, an alkyl halide or acyl halide)
resulting in an expansion of the valence of the electron donating
atom of the Lewis base and a positive charge on the organo-onium
compound. Many of the organo-onium compounds useful in the present
invention contain at least one heteroatom, that is, a non-carbon
atom such as N, P, O, bonded to organic or inorganic moieties. One
class of quaternary organo-onium compounds particularly useful in
the present invention broadly comprises relatively positive and
relatively negative ions wherein a phosphorus, arsenic, antimony,
or nitrogen generally comprises the central atom of the positive
ion, and the negative ion may be an organic or inorganic anion (for
example, halide, sulfate, acetate, phosphate, phosphonate,
hydroxide, alkoxide, phenoxide, bisphenoxide, etc.). Phosphoniums
are the most preferred organo-oniums for use in the present
invention.
[0030] Many of the useful organo-onium compounds are described and
known in the art. See, for example, U.S. Pat. Nos. 4,233,421
(Worm); 4,912,171 (Grootaert et al.); 5,086,123 (Guenthner et al.);
and 5,262,490 (Kolb et al.), all of whose descriptions are herein
incorporated by reference. Fluorinated oniums, such as those
described in U.S. Pat. No. 5,591,804 (Coggio et al.), and
multifunctional oniums, such as those comprising two or more onium
groups in the same molecule (for example, bisphosphoniums) may also
be employed. Representative examples include the following
individually listed compounds and mixtures thereof:
[0031] triphenylbenzyl phosphonium chloride
[0032] tributylallyl phosphonium chloride
[0033] tributylbenzyl ammonium chloride
[0034] tetraethyl phosphonium bromide
[0035] tetrabutyl phosphonium bromide
[0036] methoxypropyl tributyl phosphonium chloride
[0037] tetrabutyl ammonium bromide
[0038] 8-benzyl-1,8-diazabicyclo [5,4,0]-7-undecenium chloride
[0039] benzyl tris(dimethylamino) phosphonium chloride
[0040] benzyl(diethylamino)diphenylphosphonium chloride
[0041] Phosphonium catalysts are preferred. Generally, the
organo-onium catalyst is present in the compositions of the
invention in the amount of about 0.3 to about 5 parts by
weight.
[0042] In addition to the melt-processable aliphatic di- or
polyamine and organo-onium catalyst, the compositions of the
present invention having a first layer comprising a fluoropolymer
and a second layer comprising a hydrocarbon polymer may contain one
or more tackifiers to improve inter-layer adhesion. Although
suitable tackifiers vary greatly in chemical structure, the most
useful tackifier compounds generally will have a softening point
between approximately 90.degree. C. and 150.degree. C. Preferably,
tackifiers used in accordance with this invention are combined
along with a suitable di- or polyamine and incorporated into the
hydrocarbon polymer-containing layer to comprise between 1 and 50
weight percent of the hydrocarbon layer.
[0043] Tackifiers useful for this purpose include any of the
tackifier compounds known to improve adhesion performance
characteristics of elastomer-based adhesives. Such compounds
include, for example, the following: rosins, including gum rosins,
tall oil rosins, wood rosins, polymerized rosins, hydrogenated
rosins, and disproportionated rosins; rosin esters, including
pentaerythritol-wood rosins, pentaerythritol-stabilized rosins, and
glycerine-hydrogenated wood rosins; hydrocarbon resins, including
aliphatic and cycloaliphatic resins, aromatic resins, petroleum
resins, and dicyclopentadiene; terpenes, including alpha-pinene,
beta-pinene, d-limonene, and polyterpenes; and pure monomer resins,
including styrene resins, styrene/AMS resins, and AMS/vinyl toluene
resins.
[0044] Commercially available tackifiers useful in this invention
include Arkon.TM. P-125 tackifier, a hydrogenated C9 aromatic
hydrocarbon, and Super Ester.TM. W-125 modified rosin ester
tackifier, both available from Arakawa Chemical USA, Inc., Chicago,
Ill.; and Piccolyte.TM. S115 terpene resin tackifier, available
from Hercules, Inc., Wilmington, Del.
[0045] The mixing of the di- or polyamine and the organo-onium
catalyst may be by conventional means. For example, the di or
polyamine and the organo-onium catalyst can be melt-processed with
the second layer material, for example nylon. In some cases the di
or polyamine may react with the second layer material such that the
second layer material becomes modified. For example, a diamine such
as 1,12 dodecyl diamine (DDDA) may be blended into a polyamide such
as nylon 12, resulting in a modified nylon. The modified nylon and
a vinylidene fluoride monomer unit-containing fluoropolymer could
then be coextruded to form a multi-layer article, such as a film or
a tube.
[0046] The heat and pressure of the method by which the layers are
brought together, for example normal coextrusion processes, may be
adequate to provide sufficient adhesion. However, it may be
desirable to further treat the resulting multi-layer composition,
for example, with additional heat or pressure or both. One way of
supplying extra heat when the multi-layer composition is prepared
by extrusion is by delaying the cooling of the composition because
the composite is hot as a result of the coextrusion process. Where
additional heating or pressure is desired, it may be accomplished
by performing the steps of applying or coextruding at a temperature
higher than necessary for merely processing the several components.
Alternatively, the finished article may be held at an elevated
temperature for an extended period of time, or the finished article
may be placed in a separate means for elevating the temperature of
the article, such as an oven or heated liquid bath. A combination
of these methods may also be used.
[0047] The methods of this invention provide multi-layer
compositions with improved inter-layer adhesion. The methods and
compositions of this invention are particularly useful for making
articles, such as tubing and hoses, suitable for use in motor
vehicles, for example as fuel-line hoses, and for films and
blow-molded articles such as bottles and anti-graffiti films where
chemical resistance or barrier properties are important. The
two-layer compositions of this invention are also useful in
preparing compositions having three or more layers. For example, a
three layer composition of fluoropolymer to anhydride modified
polyolefin to unmodified polyolefin could be prepared and might be
useful in a fuel-tank construction.
[0048] Transparent embodiments of multi-layer compositions of the
present invention may find particular utility in the construction
of retroreflective sheeting articles generally, and particularly
when resistance to chemical agents, solvents, soils, reduced
moisture vapor transmission or good interlayer adhesion in flexible
sheetings subject to severe bending and flexing is required.
[0049] The compositions of this invention may be rendered
retroreflective by forming retroreflective elements on one side of
the composition, or alternatively, by attaching a retroreflective
base sheet by means of a transparent adhesive or by direct
lamination. The retroreflective base sheet may comprise a member
with cube corner retroreflective elements or may comprise a
microsphere-based retroreflective structure, e.g., comprising a
monolayer of transparent microspheres and reflective means disposed
on the opposite side of the monolayer from the multi-layer
composition. It is preferred that the base layer is disposed on the
non-fluoropolymer layer of the multi-layer composition. An
embodiment of this invention includes the encapsulated
retroreflective sheeting article as is disclosed in U.S. Pat. No.
3,190,178 (McKenzie), in which the cover layer is provided by a
multi-layer composition according to the present invention.
[0050] Retroreflective articles of the invention may be made in
rigid or flexible form. Multi-layer compositions of the present
invention may be used as barrier layers. An embodiment of the
present invention includes articles in accordance with U.S. Pat.
No. 5,069,964 (Tolliver) which is incorporated herein by reference,
in which the plasticizer resistant barrier layer comprises a
multi-layer composition in accordance with the present invention.
The multi-layer compositions of the present invention may find
particular utility in the construction of flexible retroreflective
sheeting articles. A preferred embodiment of the present invention
includes a retroreflective article in accordance with PCT
Publications WO 95/11464 or WO 95/11943, both of which are
incorporated herein by reference, wherein the flexible overlay film
described in PCT Publication WO 95/11464 or the flexible body layer
of PCT Publication WO 95/11943 is constituted by a multi-layer
composition in accordance with this invention.
EXAMPLES
[0051] The following abbreviations are used throughout this
section:
[0052] AT1841 is an ethylene vinylacetate copolymer available from
AT Polymer, Edmonton, Canada
[0053] DA is 1,12-dodecanediamine available from Aldrich Chemical
Co., Milwaukee, Wis.
[0054] E250 is an ethylene vinylacetate copolymer available from
E.I DuPont de Nemours, as ELVAX.TM. 250
[0055] E350 is an ethylene vinylacetate copolymer available from
E.I DuPont de Nemours as ELVAX.TM. 350
[0056] E450 is an ethylene vinylacetate copolymer available from
E.I DuPont de Nemours as ELVAX.TM. 450
[0057] HDPE is high density polyethylene available from The Dow
Chemical Company, Midland, Mich.
[0058] LLDPE is low linear density polyethylene available from The
Dow Chemical Company
[0059] MPTC is methoxy propyl tributyl phosphonium chloride
available from Dyneon, LLC
[0060] PA is a polyamide (nylon) polymer available from Creanova,
Somerset, N.J., as VESTAMIDO.TM. L2101F
[0061] PU is a polyurethane polymer available from Morton
International, Inc. as MORTHANE.TM. L424.167 (MI=9.8)
[0062] PVDF is polyvinylidene fluoride available from Elf Atochem
North America, Inc.
[0063] TBPB is tetrabutyl phosphonium bromide catalyst available
from Aldrich Chemical Co.
[0064] TEPB is tetraethyl phosphonium bromide catalyst available
from Aldrich Chemical Co.
[0065] THV200 is a terpolymer of tetrafluoroethylene,
hexafluoropropylene, and vinylidene fluoride available from Dyneon
LLC
[0066] THV500 is a terpolymer of tetrafluoroethylene,
hexafluoropropylene, and vinylidene fluoride available from Dyneon
LLC
[0067] Sample Preparation
[0068] A mixture of a substantially non-fluorinated polymer, a di-
or polyamine, and an onium catalyst was compounded in a bowl mixer
equipped with roller blades at a temperature of 200 .degree. C. for
about 10 minutes at 60 to 70 rpm. After mixing, the composition was
removed from the mixer and molded for about 30 seconds at 200
.degree. C. into a 0.2 cm thick round sheet. A multi-layer article
was made using 0.5 inch.times.2 inch (1.27 .times.cm.times.5.08 cm)
samples of the tie layer and 1 inch.times.3 inch (2.54
cm.times.7.62 cm) samples of the desired fluoropolymer or
substantially non-fluorinated polymer outside layers. To facilitate
testing of the samples via the T-Peel tests, short pieces of
silicone coated paper were placed between the tie layer and the two
"outside" test layers. The release paper created "tabs" to insert
into the jaws of the tensile tester. The multi-layer articles were
subjected to a hot press using a heated platen press at 200.degree.
C. for about 2 minutes. The samples were cooled to room temperature
by placing them in a second press that was maintained at room
temperature. The compositions of the samples and the adhesion
results are shown in Table 1. The units in Table 1 are lbF/in width
(N/2.54 cm width).
[0069] Peel Adhesion Test Procedure
[0070] The adhesion between the layer of the composition of the
invention or "tie layer" was measured according to ASTM D-1876,
commonly known as the "T-Peel" test, using an INSTRON.TM. model
1125 tensile tester, available from Instron Corporation,
Minneapolis, Minn. The test was conducted at a crosshead speed of
100 mm/minute. Each sample was placed in the tester such that the
adhesion between the tie layer and one of the "outside" layers was
measured. The peel adhesion strength was calculated as the average
load measured during the test.
[0071] In the following Examples and Comparative Examples, various
multi-layer compositions were prepared and the adhesion between the
layers was evaluated. All concentrations and percentages are by
weight unless otherwise indicated.
1 TABLE 1 Adhesion to Substrate Tie Layer LbF/in (N/2.54 cm)
Example Composition THV200 THV500 PDVF LDPE HDPE 1 AT1841/DA/TBPB 4
17.8 1.4 16.5 13.6 20/0.2/0.1 (17.8) (79.2) (6.2) (73.4) (60.5) 2
AT1841/DA/TBPB 5.5 20.6 4 12 16.4 20/0.2/0.2 (24.5) (91.6) (17.8)
(53.4) (72.9) 3 AT1841/DA/MPTPC 5.7 8.4 12 11 20/0.2/0.2 (25.4)
(37.4) (53.4) (48.9) 4 AT1841/DA/TEPB 1.2 11.4 20/0.2/0.2 (5.3)
(50.7) 5 E350/DA/TBPB 10.5 10 20/0.2/0.2 (46.7) (44.5) 6
E450/DA/TBPB 0.2 8.3 20.0.1/0.1 (0.9) (36.9) 7 E450/DA/TBPB 8.6
14.1 1.5 20/0.2/0.2 (38.2) (62.7) (6.7) 8 PA/DA/TBPB >22
20/0.1/0.1 (97.8) 9 PU/DA/TBPB 7.5 3.6 20/0.1/0.1 (33.4) (16) 10
PU/DA/TBPB 4.7 2.5 20/0.1/0.2 (20.9) (11.1) 11 PU/DA/TBPB 14 11.5
20/0.2/0.1 (62.3) (51.2) C1 E250 or AT1841 0 0 C2 AT1841/TBPB 0 0
23.5/0.5 C3 AT1841 0.sup.1 C4 PU 0 0 C5 AT1841/DA 1 2 <1 20/0.1
(4.4) (8.8) (<4.4) C6 AT1841/DA 1 3 1 14.8 17.5 20/0.2 (4.4)
(13.3) (4.4) (65.8) (77.8) C7 E350/DA 3 8.5 12 9 20/0.2 (13.3)
(37.8) (53.4) (40.0) C8 E450/DA 0.2 1.6 <1 20/0.1 (0.9) (7.1)
(<4.4) C9 PA/DA 17.5 <1 20/0.1 (77.8) (<4.4) C10 PU/DA 1.4
0.6 20/0.1 (6.2) (2.7) C11 PU/DA 12.5 9.2 20/0.2 (55.6) (40.9)
.sup.1The substrate was de-hydrofluorinated.
[0072] The data in Table 1 generally shows improved adhesion to
fluoropolymer and polyolefin substrates with the addition of an
onium catalyst while using a smaller quantity of diamine.
Examples 12-13 and Comparative Examples 12-13
[0073] The effect of the onium catalyst on the viscosity of the tie
layer composition was investigated. The viscosity of the
composition should be such that the composition can be co-extruded
onto a fluoropolymer substrate. The samples described in Table 2
were measured for viscosity at a temperature of 193 .degree. C. The
results are shown in Table 2. The units in Table 2 are Poise
(Pa.cndot.s).
2TABLE 2 Viscosity Example Composition P (Pa .multidot. s) 12
PU/DA/TBPB 1100 99/1.0/0.5 (110) 13 PU/DA/TBPB 2600 99/0.5/0.5
(260) C12 PU/DA 1200 99/1 (120) C13 PU/DA 3000 99.5/0.5 (300)
[0074] The reduction in the amount of diamine used for bonding
polyurethane to fluoropolymer reduces the degradation of
polyurethanes and the crosslinking of functionalized polyolefins.
The addition of an onium catalyst does not affect the viscosity of
the polyolefin.
* * * * *