U.S. patent application number 16/889857 was filed with the patent office on 2020-09-17 for amine-containing polymers, dispersions thereof and methods of making and using the same.
This patent application is currently assigned to 3M Innovative Properties Company. The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Michael J. Bulinski, Michael G. Costello, Denis Duchesne, Klaus Hintzer, William M. Lamanna, Kai H. Lochhaas, Michael J. Parent, Sean M. Smith.
Application Number | 20200291144 16/889857 |
Document ID | / |
Family ID | 1000004870023 |
Filed Date | 2020-09-17 |
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United States Patent
Application |
20200291144 |
Kind Code |
A1 |
Bulinski; Michael J. ; et
al. |
September 17, 2020 |
Amine-Containing Polymers, Dispersions Thereof and Methods of
Making and Using the Same
Abstract
Described herein is a polymer comprising: interpolymerized units
of (i) a fluorinated terminal alkene monomer and (ii) a tertiary
amine-containing fluorinated monomer comprising at least one of a
vinyl amine, a substituted vinyl amine, an allyl amine, a
substituted allyl amine, and combinations thereof, wherein the
polymer can be amorphous or semi-crystalline with a melting point
no greater than 325.degree. C. Dispersions thereof and methods of
making and using the same are also described.
Inventors: |
Bulinski; Michael J.;
(Stillwater, MN) ; Costello; Michael G.; (Afton,
MN) ; Duchesne; Denis; (Woodbury, MN) ;
Hintzer; Klaus; (Kastl, DE) ; Lamanna; William
M.; (Stillwater, MN) ; Lochhaas; Kai H.;
(Neuotting, DE) ; Parent; Michael J.; (Lake Elmo,
MN) ; Smith; Sean M.; (Woodbury, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
1000004870023 |
Appl. No.: |
16/889857 |
Filed: |
June 2, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15781163 |
Jun 4, 2018 |
10703833 |
|
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PCT/US2016/066253 |
Dec 13, 2016 |
|
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16889857 |
|
|
|
|
62268665 |
Dec 17, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F 226/06 20130101;
C08F 14/24 20130101; C08F 26/06 20130101; C08F 2/16 20130101; C09D
127/12 20130101; C08F 14/28 20130101; C08F 214/26 20130101; C08F
226/02 20130101; C08F 214/22 20130101; C08F 14/26 20130101; C09D
127/18 20130101; C08F 26/02 20130101; C09D 127/20 20130101; C08F
214/18 20130101; C08F 14/22 20130101; C09D 127/16 20130101 |
International
Class: |
C08F 14/22 20060101
C08F014/22; C09D 127/16 20060101 C09D127/16; C09D 127/18 20060101
C09D127/18; C08F 214/26 20060101 C08F214/26; C08F 214/22 20060101
C08F214/22; C09D 127/12 20060101 C09D127/12; C08F 214/18 20060101
C08F214/18; C08F 2/16 20060101 C08F002/16; C08F 14/24 20060101
C08F014/24; C08F 14/26 20060101 C08F014/26; C08F 14/28 20060101
C08F014/28; C08F 26/02 20060101 C08F026/02; C08F 26/06 20060101
C08F026/06; C09D 127/20 20060101 C09D127/20 |
Claims
1. An aqueous dispersion comprising a fluorinated polymer
comprising: (a) an aqueous continuous phase; (b) a plurality of
fluorinated polymer particles, wherein the fluorinated polymer
particle comprises interpolymerized units of (i) a fluorinated
terminal alkene monomer and (ii) a tertiary amine-containing
fluorinated monomer wherein the tertiary amine-containing
fluorinated monomer is selected from at least one of the following
formulas: ##STR00025## where X.sup.1 is selected from H or F;
X.sup.2 is selected from H or F; X.sup.3 is selected from H or F;
and each R.sub.f group are (i) independently selected from a linear
or branched perfluorinated alkyl group comprising 1 to 8 carbon
atoms and optionally comprising at least one catenated O or N atom;
or (ii) bonded together to form a ring structure comprising 4 to 8
carbon atoms and optionally comprising at least one catenated O or
N atom; or ##STR00026## where X.sup.1, X.sup.2, and X.sup.3 are
independently selected from H, or F; Y.sup.1 is H or F; Y.sup.2 is
For CF.sub.3; and each R.sub.f group are (i) independently selected
from a linear or branched perfluorinated alkyl group comprising 1
to 8 carbon atoms and optionally comprising at least one catenated
O or N atom; or (ii) bonded together to form a ring structure
comprising 4 to 8 carbon atoms and optionally comprising at least
one catenated O or N atom; and (c) a hydrocarbon surfactant.
2. The aqueous dispersion of claim 1, wherein the hydrocarbon
surfactant is non-ionic.
3. The aqueous dispersion of claim 1, wherein the aqueous
dispersion comprises at least 2 wt % and at most 10 wt % of the
hydrocarbon surfactant.
4. The aqueous dispersion of claim 1, wherein the aqueous
dispersion comprises 5 to 60% by weight of the plurality of
fluorinated polymer particles.
5. The aqueous dispersion of claim 1, wherein the fluorinated
terminal alkene monomer is tetrafluoroethylene.
6. The aqueous dispersion of claim 1, wherein the fluorinated
terminal alkene monomer comprises at least one of
tetrafluoroethylene; vinylidene fluoride; hexafluoropropylene;
chlorotrifluoroethylene; 2,3,3,3-tetrafluoropropene; and
combinations thereof.
7. The aqueous dispersion of claim 1, wherein the tertiary
amine-containing fluorinated monomer comprises at least one of:
##STR00027## ##STR00028## and combinations thereof.
8. The aqueous dispersion of claim 1, wherein the tertiary
amine-containing fluorinated monomer comprises at least one of:
##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033##
##STR00034## and combinations thereof.
9. The aqueous dispersion of claim 1, wherein the hydrocarbon
surfactant is non-ionic or anionic.
10. The aqueous dispersion of claim 1, wherein the fluorinated
polymer particles of the plurality of fluorinated polymer particles
have an average particle diameter of 30 to 400 nm.
11. The aqueous dispersion of claim 1, further comprising a
fluorinated liquid.
12. The aqueous dispersion of claim 1, wherein the fluorinated
polymer particle comprises a cure-site selected from Br, I,
nitrile, and combinations thereof.
13. The aqueous dispersion of claim 1, wherein the fluorinated
polymer particle is semi-crystalline.
14. The aqueous dispersion of claim 13, wherein the fluorinated
polymer particle has a melting point no greater than 325.degree.
C.
15. The aqueous dispersion of claim 1, wherein the fluorinated
polymer particle is amorphous.
16. A coating composition comprising the dispersion of claim 1.
17. A method of coating a substrate comprising: contacting the
aqueous dispersion of claim 1 onto a substrate.
18. The method of coating a substrate of claim 17, wherein the
substrate comprises at least one of metal, glass, wood, ceramic,
fabric, plastic, and combinations thereof.
19. A method of making a fluoropolymer comprising: (a) polymerizing
in an aqueous continuous phase, (i) a fluorinated terminal alkene
monomer and (ii) a tertiary amine-containing fluorinated monomer
wherein the tertiary amine-containing fluorinated monomer is
selected from at least one of the following formulas: ##STR00035##
where X.sup.1 is selected from H or F; X.sup.2 is selected from H
or F; X.sup.3 is selected from H or F; and each R.sub.f group are
(i) independently selected from a linear or branched perfluorinated
alkyl group comprising 1 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; or (ii) bonded
together to form a ring structure comprising 4 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom; or
##STR00036## where X.sup.1, X.sup.2, and X.sup.3 are independently
selected from H, or F; Y.sup.1 is H or F; Y.sup.2 is For CF.sub.3;
and each R.sub.f group are (i) independently selected from a linear
or branched perfluorinated alkyl group comprising 1 to 8 carbon
atoms and optionally comprising at least one catenated O or N atom;
or (ii) bonded together to form a ring structure comprising 4 to 8
carbon atoms and optionally comprising at least one catenated O or
N atom.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of Ser. No.
15/781,163, filed Jun. 4, 2018, which is a national stage filing
under 35 U.S.C. 371 of PCT/US2016/066253, filed Dec. 13, 2016,
which claims the benefit of U.S. Application No. 62/268,665, filed
Dec. 17, 2015, the disclosure of which is incorporated by reference
in its/their entirety herein.
TECHNICAL FIELD
[0002] Amine-containing polymers and polymer dispersions are
disclosed along with the method of making and using them.
BACKGROUND
[0003] Fluoropolymers have been long known and have been used in a
variety of applications because of several desirable properties
such as heat resistance, chemical resistance, weatherability,
UV-stability, low friction and anti-stick properties, etc.
[0004] To improve the thermal and chemical resistance of a
substrate or to provide anti stick or low friction properties to a
substrate, the substrate is coated or impregnated with
fluoropolymers. The fluoropolymers may be applied to the substrate
by liquid coating techniques if they are provided as a liquid
formulation, such as for example, dispersions.
[0005] Fluoropolymer dispersions can be conveniently produced by
aqueous polymerization techniques. Aqueous polymerization, wherein
the continuous phase is water-based can be more desirable than
solvent-based polymerizations, for a couple reasons. Water is
generally easier to handle from an environmental, regulatory, and
safety perspective. Further, there is not a need to dispose of
large amounts of solvent as encountered in solvent
polymerization.
SUMMARY
[0006] There is a desire for identifying alternative fluorinated
polymers. Advantageously, the fluoropolymers of the present
disclosure can also be offered as aqueous, stable dispersions.
[0007] In one aspect, an aqueous dispersion is described comprising
a fluorinated polymer comprising: [0008] (a) an aqueous continuous
phase; [0009] (b) a plurality of fluorinated polymer particles,
wherein the fluorinated polymer particle comprises interpolymerized
units of (i) a fluorinated terminal alkene monomer and (ii) a
tertiary amine-containing fluorinated monomer comprising at least
one of a vinyl amine, a substituted vinyl amine, an allyl amine, a
substituted allyl amine, and combinations thereof.
[0010] In one embodiment, the aqueous dispersion further comprises
a hydrocarbon surfactant.
[0011] In another aspect, a polymer is described comprising:
interpolymerized units of (i) a fluorinated terminal alkene monomer
and (ii) a tertiary amine-containing fluorinated monomer comprising
at least one of a vinyl amine, a substituted vinyl amine, an allyl
amine, a substituted allyl amine, and combinations thereof; wherein
the polymer is amorphous or is semi-crystalline with a melting
point no greater than 325.degree. C.
[0012] In yet another aspect, a method of making a fluoropolymer is
described, the method comprising: polymerizing in an aqueous
continuous phase, (i) a fluorinated terminal alkene monomer and
(ii) a tertiary amine-containing fluorinated monomer comprising at
least one of a vinyl amine, a substituted vinyl amine, an allyl
amine, a substituted allyl amine, and combinations thereof.
[0013] The above summary is not intended to describe each
embodiment. The details of one or more embodiments of the invention
are also set forth in the description below. Other features,
objects, and advantages will be apparent from the description and
from the claims.
DETAILED DESCRIPTION
[0014] As used herein, the term
[0015] "a", "an", and "the" are used interchangeably and mean one
or more; and
[0016] "and/or" is used to indicate one or both stated cases may
occur, for example A and/or B includes, (A and B) and (A or B);
[0017] "backbone" refers to the main continuous chain of the
polymer;
[0018] "crosslinking" refers to connecting two pre-formed polymer
chains using chemical bonds or chemical groups;
[0019] "cure site" refers to functional groups, which may
participate in crosslinking;
[0020] "interpolymerized" refers to monomers that are polymerized
together to form a polymer backbone;
[0021] "monomer" is a molecule which can undergo polymerization
which then form part of the essential structure of a polymer;
[0022] "perfluorinated" means a group or a compound wherein all the
hydrogen atoms in the C--H bonds have been replaced by fluorine
atoms to form C--F bonds. In one embodiment, all of the C--H bonds
are replaced with C--F bond. Alternatively, the group or compound
has no C--H bonds, and some of the C--F bonds are replaced with
C--I, C--Cl, and/or C--Br bonds; and
[0023] "polymer" refers to a macrostructure having a number average
molecular weight (Mn) of at least 50,000 dalton, at least 100,000
dalton, at least 300,000 dalton, at least 500,000 dalton, at least,
750,000 dalton, at least 1,000,000 dalton, or even at least
1,500,000 dalton and not such a high molecular weight as to cause
premature gelling of the polymer.
[0024] Also herein, recitation of ranges by endpoints includes all
numbers subsumed within that range (e.g., 1 to 10 includes 1.4,
1.9, 2.33, 5.75, 9.98, etc.).
[0025] Also herein, recitation of "at least one" includes all
numbers of one and greater (e.g., at least 2, at least 4, at least
6, at least 8, at least 10, at least 25, at least 50, at least 100,
etc.).
[0026] The present disclosure is directed toward the polymerization
of tertiary amine-containing fluorinated monomers in aqueous
solutions to form fluoropolymers. The fluoropolymers may be
amorphous or semi-crystalline in nature.
[0027] The tertiary amine-containing fluorinated monomers of the
present disclosure comprise at least one of a vinyl amine, a
substituted vinyl amine, an allyl amine, or a substituted allyl
amine.
[0028] In one embodiment, the vinyl amine-containing monomers are
of the general formula (I):
##STR00001##
where X.sup.1 is selected from H or F; X.sup.2 is selected from H
or F; X.sup.3 is selected from H or F; and each R.sub.f group are
(i) independently selected from a linear or branched perfluorinated
alkyl group comprising 1 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; or (ii) bonded
together to form a ring structure comprising 4 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom.
[0029] Exemplary vinyl amine-containing monomers include:
##STR00002##
and combinations thereof.
[0030] In one embodiment, the substituted vinyl amine-containing
monomers are of the general formula (II):
##STR00003##
where X.sup.1 is selected from H, F, or CF.sub.3; X.sup.2 is
selected from H or F; X.sup.3 is selected from H, F, or a C1-C4
alkyl or a C1-C4 fluoroalkyl, wherein at least one of X.sup.1,
X.sup.2 or X.sup.3 is not H or F; and each Rf group are (i)
independently selected from a linear or branched perfluorinated
alkyl group comprising 1 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; or (ii) bonded
together to form a ring structure comprising 4 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom.
[0031] Exemplary substituted vinyl amine-containing monomers
include:
##STR00004##
and combinations thereof.
[0032] In one embodiment, the tertiary amine-containing fluorinated
monomers are of the general formula (III):
##STR00005##
where X.sup.1 is CF.sub.3, F, or H; X.sup.2 is F or H; X.sup.3 is
CF.sub.3, F, CF.sub.2H. or CH.sub.3; each Rf group is (i)
independently selected from a linear or branched fluorinated alkyl
group comprising 1 to 8 carbon atoms and optionally comprising at
least one catenated O or N atom; or (ii) bonded together to form a
ring structure comprising 4 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; and the monomer
includes a total of 1-4 hydrogen atoms; with the provisos that at
least one of X and A is F or H; when A is CF.sub.3 or F, at least
one of X and Q is H; when A is CH.sub.3, at least one of X and Q is
F, and when X is CF.sub.3, then Q is H and A is F; and wherein at
least one of the Rf groups has two or more carbon atoms. Such
molecules of Formula (III) are described in U.S. Prov. Appl. No.
62/171,446, filed Jun. 5, 2015.
[0033] In one embodiment, the allyl amine-containing monomers are
of the general formula (IV):
##STR00006##
where X.sup.1, X.sup.2, and X.sup.3 are independently selected from
H, or F; Y.sup.1 is H or F; Y.sup.2 is For CF.sub.3: and each
R.sub.f group are (i) independently selected from a linear or
branched perfluorinated alkyl group comprising 1 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom; or
(ii) bonded together to form a ring structure comprising 4 to 8
carbon atoms and optionally comprising at least one catenated O or
N atom.
[0034] Exemplary allyl amine-containing monomers include:
##STR00007##
and combinations thereof.
[0035] In one embodiment, the substituted allyl amine-containing
monomers are of the general formula (V):
##STR00008##
where X.sup.1, X.sup.2, and X.sup.3 are independently selected from
H, F, or CF.sub.3; Y.sup.1 is H or F; Y.sup.2 is F or CF.sub.3;
wherein at least one of X.sup.1, X.sup.2, or X.sup.3 is CF.sub.3;
and each R.sub.f group are (i) independently selected from a linear
or branched perfluorinated alkyl group comprising 1 to 8 carbon
atoms and optionally comprising at least one catenated O or N atom;
or (ii) bonded together to form a ring structure comprising 4 to 8
carbon atoms and optionally comprising at least one catenated O or
N atom.
[0036] Exemplary substituted allyl amine-containing monomers
include:
##STR00009## ##STR00010## ##STR00011##
and combinations thereof.
[0037] In one embodiment, the tertiary amine-containing monomers
are of the general formula (VI):
##STR00012##
where X.sup.3 is F or CF.sub.3; Y.sup.1 is F or H; Y.sup.2 is F or
CF.sub.3; and each Rf group is (i) independently selected from a
linear or branched perfluorinated alkyl group comprising 1 to 8
carbon atoms and optionally comprising at least one catenated O or
N atom; or (ii) bonded together to form a ring structure comprising
4 to 8 carbon atoms and optionally comprising at least one
catenated O or N atom with the proviso that when Y.sup.2 is
CF.sub.3 then X.sup.3 is F and when X.sup.3 is CF.sub.3 then
Y.sup.2 is F. Such molecules of Formula (VI) are described in U.S.
Prov. Appl. No. 62/262,200 filed Dec. 2, 2015.
[0038] The fluorinated tertiary amine-containing monomer disclosed
herein is polymerized in the presence of a fluorinated terminal
alkene monomer. Such fluorinated terminal alkene monomer include:
tetrafluoroethylene (TFE), hexafluoropropylene (HFP), vinylidene
fluoride (VDF), vinyl fluoride, 2,3,3,3-tetrafluoropropene
(R1234yf), and chlorotrifluoroethylene (CTFE).
[0039] In one embodiment, the tertiary amine-containing monomer is
used at least 0.01, 0.1, 0.5, 1, or even 5 mole % and at most 10,
20, or even 40 mole % versus the other monomers in the
fluoropolymer.
[0040] In one embodiment the fluoropolymer comprises: 0 to 99 mole
% TFE; 0 to 99 mole % VDF; 0 to 30 mole % HFP; 0 to 99 mole % vinyl
fluoride; 0 to 99 mole % R1234yf; 0 to 99 mole % CTFE; and 0.01 to
40 mole % of the tertiary amine-containing monomer disclosed
herein.
[0041] Additional fluorinated and non-fluorinated co-monomers may
be used in the polymerization. Exemplary nonfluorinated co-monomers
include: ethylene, and propylene.
[0042] Exemplary fluorinated co-monomers include: partially
fluorinated dienes such as CH.dbd.CHR.sub.fCH.dbd.CH.sub.2, wherein
Rf is a perfluorinated alkylene group, which may comprise 2, 3, 4,
5, 6, 7, 8, 9, 10, 11, 12 carbon atoms for example; fluorinated
alkyl vinyl ethers, fluorinated alkoxy vinyl ethers; and
combinations thereof. In one embodiment, at least 0.1% and no more
than 1, 3, or even 5 mole % of the partially fluorinated diene
monomer is used in making the fluoropolymer (versus the other
monomers). In one embodiment, at least 0.1% and no more than 5, 10,
20, or even 40 mole % of the fluorinated alkyl vinyl ethers and
fluorinated alkoxy vinyl ethers is used in making the fluoropolymer
(versus the other monomers). Examples of fluorinated co-monomers
are of the Formula (VII)
CF.sub.2.dbd.CF(CF.sub.2).sub.bO(R.sub.f''O)(R.sub.f'O).sub.mR.sub.f
(VII)
where R.sub.f'' and R.sub.f' are independently linear or branched
perfluoroalkylene radical groups comprising 2, 3, 4, 5, or 6 carbon
atoms; b=0 or 1; m and n are independently an integer selected from
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; and R.sub.f is a
perfluoroalkyl group comprising 1, 2, 3, 4, 5, or 6 carbon atoms.
Examplary perfluorovinyl ether monomers include: perfluoro (methyl
vinyl) ether (PMVE), perfluoro (ethyl vinyl) ether (PEVE),
perfluoro (n-propyl vinyl) ether (PPVE-1),
perfluoro-2-propoxypropylvinyl ether (PPVE-2),
perfluoro-3-methoxy-n-propylvinyl ether,
perfluoro-2-methoxy-ethylvinyl ether,
perfluoro-methoxy-methylvinylether
(CF.sub.3--O--CF.sub.2--O--CF.dbd.CF.sub.2), and
CF.sub.3--(CF.sub.2).sub.2--O--CF(CF.sub.3)--CF.sub.2--O--CF(CF.sub.3)--C-
F.sub.2--O--CF.dbd.CF.sub.2, perfluoro (methyl allyl) ether
(CF--CF--CF.sub.2--O--CF.sub.3), perfluoro (ethyl allyl) ether,
perfluoro (n-propyl allyl) ether, perfluoro-2-propoxypropyl allyl
ether, perfluoro-3-methoxy-n-propylallyl ether,
perfluoro-2-methoxy-ethyl allyl ether, perfluoro-methoxy-methyl
allyl ether, and
CF.sub.3--(CF.sub.2).sub.2--O--CF(CF.sub.3)--CF.sub.2--O--CF(CF.sub.3)--C-
F.sub.2--O--CF.sub.2CF.dbd.CF.sub.2, and combinations thereof. In
one embodiment, at least 0.1% and no more than 5, 10, 20, or even
40 mole % of the fluorinated co-monomers of Formula (VII) are used
in making the fluoropolymer (versus the other monomers).
[0043] Other fluorinated co-monomers include those corresponding to
formula: CF.sub.2.dbd.CF--R.sup.d.sub.f or
CH.sub.2--CH--R.sup.d.sub.f wherein R.sup.d.sub.f represents a
perfluoroalkyl group of 1-10, or even 1-5 carbon atoms, which can
be used in at least 0.1% and no more than 5 or even 10 mole % in
making the fluoropolymer.
[0044] In the present disclosure, the fluorinated polymer may be
polymerized in the presence of a halogenated chain transfer agent
and/or cure site monomers to introduce cure sites into the
fluoropolymer.
[0045] Exemplary chain transfer agents include: an iodo-chain
transfer agent, a bromo-chain transfer agent, or a chloro-chain
transfer agent. For example, suitable iodo-chain transfer agent in
the polymerization include the formula of RI.sub.x, where (i) R is
a perfluoroalkyl or chloroperfluoroalkyl group having 3 to 12
carbon atoms; and (ii) x=1 or 2. The iodo-chain transfer agent may
be a perfluorinated iodo-compound. Exemplary
iodo-perfluoro-compounds include 1,3-diiodoperfluoropropane,
1,4-diiodoperfluorobutane, 1, 6-diiodoperfluorohexane,
1,8-diiodoperfluorooctane, 1,10-diiodoperfluorodecane,
1,12-diiodoperfluorododecane,
2-iodo-1,2-dichloro-1,1,2-trifluoroethane,
4-iodo-1,2,4-trichloroperfluorobutan, and mixtures thereof. In some
embodiments, the bromine is derived from a brominated chain
transfer agent of the formula: RBr.sub.x, where (i) R is a
perfluoroalkyl or chloroperfluoroalkyl group having 3 to 12 carbon
atoms; and (ii) x=1 or 2. The chain transfer agent may be a
perfluorinated bromo-compound.
[0046] Cure-site monomers, if used, comprise at least one of a
bromine, iodine, and/or nitrile cure moiety. Typically, cure site
monomers are used at least at 0.01, 0.1, 0.5, or even 1% and at
most 2, 4, or even 5 mole % versus the other monomers used to make
the fluoropolymer.
[0047] In one embodiment, the cure site monomers may be derived
from one or more compounds of the formula: (a) CX.sub.2.dbd.CX(Z),
wherein: (i) X each is independently H or F; and (ii) Z is I, Br,
R.sub.f--U wherein U.dbd.I or Br and R.sub.f=a perfluorinated or
partially perfluorinated alkylene group optionally containing O
atoms or (b) Y(CF.sub.2).sub.qY, wherein: (i) Y is Br or I or Cl
and (ii) q=1-6. In addition, non-fluorinated bromo- or
iodo-olefins, e.g., vinyl iodide and allyl iodide, can be used. In
some embodiments, the cure site monomers are derived from one or
more compounds selected from the group consisting of
CH.sub.2.dbd.CHI, CF.sub.2.dbd.CHI, CF.sub.2.dbd.CFI,
CH.sub.2.dbd.CHCH.sub.2I, CF.sub.2.dbd.CFCF.sub.2I,
ICF.sub.2CF.sub.2CF.sub.2CF.sub.2I,
CH.sub.2.dbd.CHCF.sub.2CF.sub.2I, CF.sub.2.dbd.CFCH.sub.2CH.sub.2I,
CF.sub.2--CFCF.sub.2CF.sub.2I,
CH.sub.2.dbd.CH(CF.sub.2).sub.6CH.sub.2CH.sub.2I,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2I, CF--CFOCFCF.sub.2CF.sub.2I,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CH.sub.2I,
CF.sub.2.dbd.CFCF.sub.2OCH.sub.2CH.sub.2I,
CF.sub.2.dbd.CFO(CF.sub.2).sub.3--OCF.sub.2CF.sub.2I,
CF.sub.2.dbd.CF--O--(CF.sub.2).sub.4--I, CH.sub.2.dbd.CHBr,
CF.sub.2.dbd.CHBr, CF.sub.2.dbd.CFBr, CH.sub.2.dbd.CHCH.sub.2Br,
CF.sub.2.dbd.CFCF.sub.2Br, CH.sub.2.dbd.CHCF.sub.2CF.sub.2Br,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2Br, CF.sub.2.dbd.CFCl,
CF.sub.2.dbd.CFCF.sub.2Cl, and combinations thereof.
[0048] In another embodiment, the cure site monomers comprise
nitrile-containing cure moieties. Useful nitrogen-containing cure
site monomers include nitrile-containing fluorinated olefins and
nitrile-containing fluorinated vinyl ethers, such as:
perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene);
CF.sub.2.dbd.CFO(CF.sub.2).sub.LCN wherein L is an integer from 2
to 12; CF.sub.2.dbd.CF(O(CF.sub.2).sub.uOCF(CF.sub.3)CN wherein u
is an integer from 2 to 6;
CF.sub.2.dbd.CFO[CF.sub.2CF(CF.sub.3)O].sub.q(CF.sub.2O).sub.yCF(CF.sub.3-
)CN or
CF.sub.2.dbd.CFO[CF.sub.2CF(CF.sub.3)O].sub.q(CF.sub.2).sub.yOCF(CF-
.sub.3)CN wherein q is an integer from 0 to 4 and y is an integer
from 0 to 6; or
CF.sub.2.dbd.CF[OCF.sub.2CF(CF.sub.3)].sub.rO(CF.sub.2).sub.tCN
wherein r is 1 or 2, and t is an integer from 1 to 4; and
derivatives and combinations of the foregoing. Examples of a
nitrile-containing cure site monomer include
CF.sub.2.dbd.CFO(CF.sub.2).sub.5CN,
CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)OCF.sub.2CF.sub.2CN,
CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)OCF.sub.2CF(CF.sub.3)CN,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CF.sub.2OCF(CF.sub.3)CN,
CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)OCF.sub.2CF.sub.2CN; and
combinations thereof.
[0049] The polymers of the present disclosure are obtained with any
of the known aqueous polymerization techniques. The polymers are
preferably made through an aqueous emulsion polymerization process,
which can be conducted in a known manner including batch,
semi-batch, or continuous polymerization techniques. The reactor
vessel for use in the aqueous emulsion polymerization process is
typically a pressurizable vessel capable of withstanding the
internal pressures during the polymerization reaction. Typically,
the reaction vessel will include a mechanical agitator, which will
produce thorough mixing of the reactor contents and heat exchange
system. Any quantity of the monomer(s) may be charged to the
reactor vessel. The monomers may be charged batchwise or in a
continuous or semicontinuous manner. By semicontinuous is meant
that a plurality of batches of the monomer are charged to the
vessel during the course of the polymerization. The independent
rate at which the monomers are added to the kettle, will depend on
the consumption rate with time of the particular monomer.
Preferably, the rate of addition of monomer will equal the rate of
consumption of monomer, i.e. conversion of monomer into
polymer.
[0050] The reaction kettle is charged with water. To the aqueous
phase there is generally also added a fluorinated surfactant,
typically a non-telogenic fluorinated surfactant although aqueous
emulsion polymerization without the addition of fluorinated
surfactant may also be practiced.
[0051] When used, the fluorinated surfactant is typically used in
amount of 0.01% by weight to 1% by weight. Suitable fluorinated
surfactants include any fluorinated surfactant commonly employed in
aqueous emulsion polymerization. Particularly preferred fluorinated
surfactants are those that correspond to the general formula:
Y--R.sub.f--Z-M
wherein Y represents hydrogen, Cl or F; R.sub.f represents a linear
or branched perfluorinated alkylene having 4 to 10 carbon atoms; Z
represents COO.sup.- or SO.sub.3.sup.- and M represents an alkali
metal ion or an ammonium ion. Exemplary emulsifiers include:
ammonium salts ofperfluorinated alkanoic acids, such as
perfluorooctanoic acid and perfluorooctane sulphonic acid.
[0052] Also contemplated for use in the preparation of the polymers
described herein are emulsifiers of the general formula:
[R.sub.f--O-L-COO.sup.-].sub.iX.sub.i.sup.+ (VI)
wherein L represents a linear partially or fully fluorinated
alkylene group or an aliphatic hydrocarbon group, R.sub.f
represents a linear partially or fully fluorinated aliphatic group
or a linear partially or fully fluorinated group interrupted with
one or more oxygen atoms, X.sub.i.sup.+ represents a cation having
the valence i and i is 1, 2 and 3. Specific examples are described
in, for example, US Pat. Publ. 2007/0015937 (Hintzer et al.).
Exemplary emulsifiers include:
CF.sub.3CF.sub.2OCF.sub.2CF.sub.2OCF.sub.2COOH,
CHF.sub.2(CF.sub.2).sub.5COOH, CF.sub.3(CF.sub.2).sub.6COOH.
CF.sub.3O(CF.sub.2).sub.3OCF(CF.sub.3)COOH,
CF.sub.3CF.sub.2CH.sub.2OCF.sub.2CH.sub.2OCF.sub.2COOH,
CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2COOH,
CF.sub.3O(CF.sub.2).sub.3OCF.sub.2COOH,
CF.sub.3(CF.sub.2).sub.3(CH.sub.2CF.sub.2).sub.2CF.sub.2CF.sub.2CF.sub.2C-
OOH, CF.sub.3(CF.sub.2).sub.2CH.sub.2(CF.sub.2).sub.2COOH,
CF.sub.3(CF.sub.2).sub.2COOH,
CF.sub.3(CF.sub.2).sub.2(OCF(CF.sub.3)CF.sub.2)OCF(CF.sub.3)COOH,
CF.sub.3(CF.sub.2)(OCF.sub.2CF.sub.2).sub.4OCF(CF.sub.3)COOH,
CF.sub.3CF.sub.2O(CF.sub.2CF.sub.2O).sub.3CF.sub.2COOH, and their
salts. In one embodiment, the molecular weight of the emulsifier is
less than 1500, 1000, or even 500 grams/mole.
[0053] Also contemplated for use in the preparation of the polymers
described herein are a hydrocarbon emulsifier, such as alkyl
sulfonic acids, e.g. Hostapur SAS (from Clariant), or alkyl
sulfates, e.g. sodium lauryl sulfate.
[0054] In addition to aqueous emulsion polymerization described
herein, the fluoropolymers of the present disclosure can be made
via an aqueous suspension polymerization.
[0055] In one embodiment, no organic emulsifier is used during the
polymerization. For example, U.S. Publ. No. 2013-0090441 (Baran et
al.) teaches the preparation of fluoropolymers using inorganic
nanoparticles.
[0056] These emulsifiers may be used alone or in combination as a
mixture of two or more of them. In one embodiment, the amount of
the emulsifier is well below the critical micelle concentration,
generally within a range of from 250 to 5,000 ppm (parts per
million), preferably 250 to 2000 ppm, more preferably 300 to 1000
ppm, and sometimes even up to 2 wt % based on the mass of water to
be used.
[0057] A chain transfer agent may be used to control the molecular
weight of the polymer so as to obtain the desired zero shear rate
viscosity. Useful chain transfer agents include C.sub.2-C.sub.6
hydrocarbons such as ethane, alcohols, ethers, esters including
aliphatic carboxylic acid esters and malonic esters, ketones and
halocarbons. Particularly useful chain transfer agents are
dialkylethers such as dimethyl ether and methyl tertiary butyl
ether.
[0058] In one embodiment, the polymerization is initiated after an
initial charge of the monomer by adding an initiator or initiator
system to the aqueous phase. For example peroxides can be used as
free radical initiators. Specific examples of peroxide initiators
include, hydrogen peroxide, diacylperoxides such as
diacetylperoxide, dipropionylperoxide, dibutyrylperoxide,
dibenzoylperoxide, benzoylacetylperoxide, diglutaric acid peroxide
and dilaurylperoxide, and further water soluble per-acids and water
soluble salts thereof such as e.g. ammonium, sodium or potassium
salts. Examples of per-acids include peracetic acid. Esters of the
peracid can be used as well and examples thereof include
tert-butylperoxyacetate and tert-butylperoxypivalate. A further
class of initiators that can be used are water soluble
azo-compounds. Suitable redox systems for use as initiators include
for example a combination of peroxodisulphate and hydrogen sulphite
or disulphite, a combination of thiosulphate and peroxodisulphate
or a combination of peroxodisulphate and hydrazine. Exemplary
persulphates include: sodium peroxodisulphates, potassium
peroxodisulphates, and ammonium peroxodisulphates.
[0059] Further initiators that can be used are ammonium-alkali- or
earth alkali salts of persulfates, permanganic or manganic acid or
manganic acids. The amount of initiator employed is typically
between 0.03 and 2% by weight, preferably between 0.05 and 1% by
weight based on the total weight of the polymerization mixture. The
full amount of initiator may be added at the start of the
polymerization or the initiator can be added to the polymerization
in a continuous way during the polymerization until a conversion of
70 to 80%. One can also add part of the initiator at the start and
the remainder in one or separate additional portions during the
polymerization. Accelerators such as for example water-soluble
salts of iron, copper and silver may also be added.
[0060] In one embodiment, it may be desirable to add a certain
monomer to the polymerization in the form of an aqueous
microemulsion. For example, fluorinated monomers that are liquid
under the polymerization conditions may be advantageously added in
the form of an aqueous microemulsion. The microemulsion of such
monomers is preferably prepared using a fluorinated emulsifier. The
microemulsion comprises a monomer, optional emulsifier, and
fluorinated, low telogenic, inert liquids with boiling points
higher than 100.degree. C. Examples of such liquids include: (i)
fluorinated cyclic hydrocarbons, such as octafluoronaphthalene,
octafluorotoluene, hexafluorobenzene, perfluoroperhydrophenantrene
(C.sub.14F.sub.24), perfluoroperhydrofluorene (C.sub.13F.sub.22),
perfluoro decalin (C.sub.10F.sub.18), perfluoro methyl decalin
(C.sub.11F.sub.20), perfluoro butyl decalin (C.sub.14F.sub.26),
perfluorodimethylcyclohexane (C.sub.8F.sub.16),
perfluoromethylcyclohexane (C.sub.7F.sub.14),
perfluorodimethylcyclobutane (C.sub.6F.sub.12); (ii) fluorinated
polyoxyalkenes of the formula
CF.sub.2.dbd.CF--(CF.sub.2).sub.l--O(R.sup.a.sub.fO).sub.n
(R.sup.b.sub.fO).sub.mR.sup.c.sub.f, where R.sup.a.sub.f and
R.sup.b.sub.f are different perfluoroalkylene groups of 3 to 6
C-atoms, R.sub.cf is a perfluoroalkyl group of 1 to 6 C-atoms, 1 is
0 or 1, m and n are independently 0 to 10 and n+m is >2 or
>3, examples include:
CF.sub.3--CF.sub.2--CF.sub.2--(O--CF(--CF.sub.3)--CF.sub.2).sub.2--O--CF.-
dbd.CF.sub.2 (PPVE-3),
CF.sub.3--CF.sub.2--CF.sub.2--(O--CF(--CF.sub.3)--CF.sub.2).sub.3--O--CF.-
dbd.CF.sub.2 (PPVE-4),
CHF.sub.2--CF.sub.2--CF.sub.2--(O--CF(--CF.sub.3)--CF.sub.2)--O--CF.dbd.C-
F.sub.2 (HPPVE-2),
CHF.sub.2--CF.sub.2--CF.sub.2--(O--CF(--CF.sub.3)--CF.sub.2).sub.2--O--CF-
.dbd.CF.sub.2 (HPPVE-3); (iii) fluorinated alkenes of the formula
F.sub.3C--C(R.sup.d.sub.f).dbd.C(R.sup.e.sub.f)(R.sup.f.sub.f)
where R.sup.d.sub.f and represent R.sup.e.sub.f independently from
each other fluorine or a perfluorinated or partially fluorinated,
linear or branched alkyl group, preferably a group having from 1 to
6, preferably 1 to 3, carbon atoms and R.sup.f.sub.f represents a
perfluorinated, linear or branched alkyl group of 1 to 6 carbon
atoms, preferably a methyl, ethyl, propyl or isopropyl group,
examples include:
C(--CF.sub.3X--CF.sub.3).dbd.CF--CF.sub.2--CF.sub.3 (HFP-Dimer),
and
C(--CF.sub.3).sub.2.dbd.C(--CF.sub.2--CF.sub.3)(--CF(--CF.sub.3).sub.2)
(HFP-Trimer); and (iv) fluorinated polyoxyalkanes of the formula
R.sup.g.sub.f--O--R.sup.h.sub.f--O--R.sup.i.sub.f where
R.sup.g.sub.f and R.sup.i.sub.f are independently fluorinated alkyl
groups of 2 to 5 C-atoms and R.sup.h.sub.f is a branched
perfluorinated alkyl group of 2 to 4 C-atoms, examples include:
CHF.sub.2--CF.sub.2--CF.sub.2--O--CF(--CF.sub.3)--CF.sub.2--O--CFH--CF.su-
b.3 (HTFEE-2),
CHF.sub.2--CF.sub.2--CF.sub.2--O--CF(--CF.sub.3)--CF(--CF.sub.3)--O--CF.s-
ub.2--CF.sub.2--CHF.sub.2, and
CF.sub.3--CF.sub.2--CF.sub.2--O--CF(--CF.sub.3)--CF(--CF.sub.3)--O--CF.su-
b.2--CF.sub.2--CF.sub.3. See for example, U.S. Pat. Publ. No.
2011/0294951 (Hintzer et al.), herein incorporated by
reference.
[0061] The aqueous emulsion polymerization may be carried out at
temperatures between 10 to 150.degree. C., or even 30.degree. C. to
110.degree. C. and the pressure is typically between 2 and 50 bar,
or even 5 to 30 bar. The reaction temperature may be varied during
the polymerization to influence the molecular weight distribution,
i.e., to obtain a broad molecular weight distribution or to obtain
a bimodal or multimodal molecular weight distribution.
[0062] The aqueous emulsion polymerization system may further
comprise auxiliaries, such as buffers and complex-formers.
[0063] The amount of polymer solids (i.e., fluorinated polymer
particles) that can be obtained at the end of the polymerization is
typically between 3-40%, 5-40%, 10-35%, or even 20-30% by weight.
Upconcentration of the polymer dispersion can be conducted to
increase the solids content, using techniques known in the art.
[0064] The fluoropolymers may have an average particle size
(Z-average) of 20 to 400 nm, 20 to 300 nm, 20 to 200 nm, or even
from about 20 nm to up to about 100 nm. The average particle sizes
can be measured by the methods known in the art, for example, by
inelastic light scattering (ISO 13321).
[0065] The fluoropolymers of the present disclosure may be
semi-crystalline or amorphous fluoropolymers. Semi-crystalline
fluoropolymers typically have a sharp melting point (i.e. a melting
point wherein the melting has occurred within a range covering less
than 3.degree. C.), or they may have a melting range. The melting
point or range typically is not greater than 330.degree. C. or even
no greater than 325.degree. C. In one embodiment the melting point
is between about 90.degree. C. to about 330.degree. C. or about
90.degree. C. to about 325.degree. C. The melting points can be
measured, for example, by DSC. An amorphous fluoropolymer has no
detectable crystalline character by DSC (differential scanning
calorimetry). If studied under DSC, the amorphous fluoropolymer has
no melting point or melt transitions with an enthalpy more than 2
milliJoules/g by DSC.
[0066] In one embodiment, the resulting polymers of the present
disclosure have a Tg (glass transition temperature) between -50 and
150.degree. C. or even -40 and 100.degree. C.
[0067] The presence of acidic end-groups is known to be detrimental
to certain properties of the fluoropolymer. In one embodiment, the
fluoropolymers of the present disclosure have a low amount of acid
end groups. Because of the monomers selected and the polymerization
methods employed, in one embodiment, the fluoropolymers of the
present disclosure have a minimal amount of ionic endgroups and
thus, they do not require a heat treatment step to achieve the low
integrated absorbance ratio disclosed herein. Acidic end groups
include carboxyl, carboxylate, and carboxamide groups. The carbonyl
content of a perfluorinated polymer may be determined by an
integrated absorbance ratio method based on Fourier transform
infrared analysis (FTIR) as described in U.S. Pat. No. 6,114,452
(Schmiegel) and U.S. Pat. No. 8,604,137 (Grootaert et al.). The
method to determine the carboxyl, carboxylate, and carboxamide
groups, relies on the baseline corrected integrated absorption
underneath prominent peaks in the FT-IR spectrum of a pressed film
of the fluorinated polymer. In particular, the integrated
absorbance of the most prominent peaks between approximately 1620
cm.sup.-1 to 1840 cm.sup.-1 are measured. These peaks correspond to
absorbances attributable to carbonyl moieties present in the
polymer. This baseline corrected integrated absorbance under the
most intense peaks within the range of 1620 cm.sup.-1 and 1840
cm.sup.-1 is divided by the baseline corrected integrated
absorbance of the C--F stretch overtone between 2220 cm.sup.-1, and
2740 cm.sup.-1, which is indicative of the thickness of the sample.
This gives the carbonyl absorbance ratio which characterizes the
carboxyl, carboxylate, and carboxamide content of the polymer. The
polymers useful in this disclosure have an integrated absorbance
ratio less than 0.1, 0.08, 0.07, less than 0.04, or even less than
0.03.
[0068] The above described method discloses a method of
polymerizing a fluorinated terminal alkene monomer with a tertiary
amine-containing fluorinated monomer disclosed herein (e.g., vinyl
amine, substituted vinyl amine, allyl amine, substituted allyl
amine, and combinations thereof) to form a fluorinated polymer
dispersion. The polymerization can be done in the presence of an
emulsifier, such as a fluorinated emulsifier or a non-fluorinated
emulsifier.
[0069] As used herein the term "emulsifier" is used to refer to a
compound, which stabilizes an emulsion during a polymerization by
migrating to the interface between the continuous (e.g. water) and
the particle phases and imparting electrostatic, steric, or a
combination of these repulsive forces to maintain the total surface
area of the interface. A "surfactant" is used herein to refer to a
compound, which stabilizes a polymerized dispersion. A compound
used as an emulsifier may or may not be used as a surfactant. Thus,
emulsifiers listed herein may or may not be used as surfactants and
vice versa. Generally, emulsifiers are used in lower concentrations
than surfactants, for example, a compound may be used up to 1 wt %
or 2 wt % as an emulsifier versus total dispersion weight, but as a
surfactant used at concentrations of at least 2 wt %, or even 5 wt
%, and at most 10 wt % versus total dispersion weight.
[0070] Because there has been an interest in the elimination of
residual fluorinated emulsifiers/surfactants in fluoropolymer
products; in one embodiment, the polymers can be made in the
presence of a fluorinated emulsifier and then the fluorinated
emulsifier may be removed from the fluoropolymer dispersion using
techniques in the art (such as anion exchange methods). Depending
on the particular method for reducing the fluorinated emulsifier; a
non-fluorinated, non-ionic, and/or anionic surfactant can be used
as the stabilizing agent. Crude dispersions (i.e., dispersion
directly from the polymerization of the fluorinated monomers)
typically have a solids content of 3 to 40%, or even 10 to 40% by
weight. Non-fluorinated surfactants are typically added to the
crude dispersions in amount sufficient to provide a desired
dispersion stability after reduction of the fluorinated surfactant.
An amount from 0.5 to 20% by weight, 1 to 12%, or even I to 10% by
weight of non-ionic/anionic surfactant is generally sufficient for
this purpose. Although reducing the amount of fluorinated
surfactant in the crude dispersion is generally preferred, it is
also possible to reduce the amount of fluorinated surfactant while
upconcentrating the dispersion or after upconcentration of the
dispersion. If an upconcentrated dispersion is used, the amount of
solids may be between 20 and 70% or even 40 and 70% by weight, for
example between 45 and 65% by weight.
[0071] Exemplary methods for removal of fluorinated emulsifier
include the following.
[0072] A non-ionic non-fluorinated surfactant is added to the
aqueous dispersion and the so obtained dispersion is contacted with
an anion or cation exchange (to remove cations, e.g. Mn.sup.2+)
resin and/or upconcentrated. See U.S. Pat. Nos. 6,833,403 and
5,463,021.
[0073] In another embodiment, the amount of fluorinated surfactant
may be reduced by ultrafiltration. The method of ultrafiltration
comprises the steps of (a) adding non-ionic and/or anionic
non-fluorinated surfactant to a dispersion and (b) circulating the
dispersion over a semi-permeable ultra-filtration membrane to
separate the dispersion into a fluorinated polymer dispersion and
an aqueous permeate. See U.S. Pat. No. 4,369,266.
[0074] In another embodiment, the amount of fluorinated surfactant
may be reduced in the dispersion through distillation of the free
acid form of the surfactant. This process can be used if the
surfactant in its free acid form is steam volatile. Typically, this
method involves adding a non-ionic and/or anionic emulsifier to the
aqueous fluoropolymer dispersion and removing steam-volatile
fluorinated emulsifier by distillation until the concentration of
steam-volatile fluorinated emulsifier in the dispersion reaches the
desired value. See U.S. Pat. No. 6,794,550.
[0075] Suitable non-fluorinated non-ionic surfactants include those
described in "Nonionic Surfactants", M. J. Schick (ed.), Marcel
Dekker, Inc., New York 1967. Examples of non-ionic surfactants can
be selected from the group of alkylarylpolyethoxy alcohols,
polyoxyalkylene alkyl ether surfactants, polysorbates and
alkoxylated acetylenic diols, preferably ethoxylated acetylenic
diols and mixtures of such surfactants.
[0076] In one embodiment, the non-ionic surfactant or mixture of
non-ionic surfactants corresponds to the general formula:
R.sup.1--O--[CH.sub.2CH.sub.2O].sub.n--[R.sup.2O].sub.m--R.sup.3
(VII)
wherein R.sup.1 represents a linear or branched aliphatic or
aromatic hydrocarbon group having at least 8 carbon atoms,
preferably 8 to 18 carbon atoms, R.sup.2 represents an alkylene
having 3 carbon atoms, R.sup.3 represents hydrogen or a
C.sub.1-C.sub.3 alkyl group, n has a value of 0 to 40, m has a
value of 0 to 40 and the sum of n+m is at least 2. When the above
general formula represents a mixture, n and m will represent the
average amount of the respective groups. Also, when the above
formula represents a mixture, the indicated amount of carbon atoms
in the aliphatic group R.sup.1 may be an average number
representing the average length of the hydrocarbon group in the
surfactant mixture. Commercially available non-ionic surfactant or
mixtures of non-ionic surfactants include those available from
Clariant GmbH under the trade designation "GENAPOL" such as
"GENAPOL X-080", a surfactant according to the above formula (XV)
in which m is 0 and "GENAPOL PF 40" a surfactant in which both n
and m are non-zero. Further suitable non-ionic surfactants that are
commercially available include the trade designations "TERGITOL TMN
6" or "TERGITOL TMN 100X", "TERGITOL TMN 10", and "TRITON
X-100".
[0077] According to a further embodiment, a mixture of one or more
surfactants according to formula (VII) in which m is 0 with one or
more surfactants according to formula (XV) with n and m each being
non-zero can be used. An example of such a mixture is a mixture of
GENAPOL X-080 and GENAPOL PF 40.
[0078] Further non-ionic surfactants that can be used include
alkoxylated acetylenic diols, for example ethoxylated acetylenic
diols. The ethoxylated acetylenic diols for use in this embodiment
preferably have a HLB between 11 and 16. Commercially available
ethoxylated acetylenic diols that may be used include those
available under the trade designation "SURFYNOL" from Air Products,
in particular "SURFYNOL 465". Still further useful non-ionic
surfactants include polysiloxane based surfactants such as those
under the trade designation "SILWET L77" commercially available
from Crompton Corp.
[0079] Exemplary anionic non-fluorinated surfactants include
surfactants that have an acid group, in particular a sulfonic or
carboxylic acid group. Anionic non-fluorinated surfactants may
include in addition to one or more anionic groups also other
hydrophilic groups such as polyoxyalkylene groups having 2 to 4
carbons in the oxyalkylene group, such as polyoxyethylene groups.
Typical non-fluorinated surfactants include anionic hydrocarbon
surfactants. The term "anionic hydrocarbon surfactants" as used
herein comprises surfactants that comprise one or more hydrocarbon
moieties in the molecule and one or more anionic groups, in
particular acid groups such as sulfonic, sulfuric, phosphoric and
carboxylic acid groups and salts thereof. Examples of hydrocarbon
moieties of the anionic hydrocarbon surfactants include saturated
and unsaturated aliphatic groups having for example 6 to 40 carbon
atoms, preferably 8 to 20 carbon atoms. Such aliphatic groups may
be linear or branched and may contain cyclic structures. The
hydrocarbon moiety may also be aromatic or contain aromatic groups.
Additionally, the hydrocarbon moiety may contain one or more hetero
atoms such as for example oxygen, nitrogen and sulfur.
[0080] Particular examples of anionic hydrocarbon surfactants for
use in this invention include alkyl sulfonates such as lauryl
sulfonate, alkyl sulfates such as lauryl sulfate,
alkylarylsulfonates and alkylarylsulfates, fatty (carboxylic) acids
and salts thereof such as lauric acids and salts thereof and
phosphoric acid alkyl or alkylaryl esters and salts thereof.
Commercially available anionic hydrocarbon surfactants that can be
used include those available under the trade designations "POLYSTEP
A16" (sodium dodecylbenzyl sulphonate) from Stepan Company,
"HOSTAPUR SAS 30" (secondary alkyl sulphonate sodium salt),
"EMULSOGEN LS" (sodium lauryl sulfate) and "EMULSOGEN EPA 1954"
(mixture of C.sub.12 to C.sub.14 sodium alkyl sulfates) available
from Clariant GmbH, "EDENOR C-12" (Lauric acid) available from
Cognis and "TRITON X-200" (sodium alkylsulfonate) available from
DOW Chemical Co., Midland, Mich. Further suitable anionic
surfactants include the sulfosuccinates disclosed in EP Nos.
1538177 and EP 1526142.
[0081] The polymers or dispersions comprising the polymers
disclosed herein may be used in coating compositions. If used for a
coating solution, it may be desirable to increase the amount of
fluoropolymer solids in the dispersion. To increase the amount of
fluoropolymer solids, any of the upconcentration techniques known
in the art may be used. These upconcentration techniques are
typically carried out in the presence of a non-ionic surfactant,
which is added to stabilize the dispersion in the upconcentration
process. Suitable methods for upconcentration include
ultrafiltration, thermal upconcentration, thermal decantation and
electrodecantation as disclosed in U.S. Pat. No. 7,279,522 (Dadalas
et al., herein incorporated by reference).
[0082] The method of ultrafiltration comprises the steps of (a)
adding non-ionic surfactant to a dispersion that desirably is to be
upconcentrated and (b) circulating the dispersion over a
semi-permeable ultra-filtration membrane to separate the dispersion
into a fluorinated polymer dispersion concentrate and an aqueous
permeate. The circulation is typically at a conveying rate of 2 to
7 meters per second and effected by pumps which keep the
fluorinated polymer free from contact with components which cause
frictional forces. The method of ultrafiltration further has the
advantage that during upconcentration also some low molecular
weight fluorinated emulsifier is removed. Accordingly, the method
of ultrafiltration may be used to simultaneously reduce the level
of low molecular weight fluorinated emulsifier and upconcentrate
the dispersion.
[0083] To increase the fluoropolymer solids in an aqueous
fluoropolymer dispersion, thermal decantation may also be employed.
In this method, a non-ionic surfactant is added to the
fluoropolymer dispersion that is desirably upconcentrated and the
dispersion is then heated so as to form a supernatant layer that
can be decanted and that typically contains water and some
non-ionic surfactant while the other layer will contain the
concentrated dispersion. This method is for example disclosed in
U.S. Pat. No. 3,037,953 (Barnard) and 6153688 (Tashiro et al.),
herein incorporated by reference.
[0084] Thermal upconcentration involves heating of the dispersion
and removal of water under a reduced pressure until the desired
concentration is obtained.
[0085] For the purpose of, for example, enhancing the strength or
imparting the functionality, conventional adjuvants, such as, for
example, acid acceptors, process aids, or colorants may be added to
the composition.
[0086] Such fillers include: an organic or inorganic filler such as
clay, silica (SiO.sub.2), alumina, iron red, talc, diatomaceous
earth, barium sulfate, wollastonite (CaSiO.sub.3), calcium
carbonate (CaCO.sub.3), calcium fluoride, titanium oxide, iron
oxide and carbon black fillers, a polytetrafluoroethylene powder.
PFA (TFE/perfluorovinyl ether copolymer) powder, an electrically
conductive filler, a heat-dissipating filler, and the like may be
added as an optional component to the composition. Those skilled in
the art are capable of selecting specific fillers at required
amounts to achieve desired physical characteristics in the finished
product. The filler components may result in a material that is
capable of retaining a preferred elasticity and physical tensile,
as indicated by an elongation and tensile strength value, while
retaining desired properties such as retraction at lower
temperature (TR-10).
[0087] In one embodiment, the composition comprises less than 40,
30, 20, 15, or even 10% by weight of the inorganic filler.
[0088] Conventional adjuvants may also be incorporated into the
composition of the present disclosure to enhance the properties of
the resulting composition. For example, acid acceptors may be
employed to facilitate the cure and thermal stability of the
compound. Suitable acid acceptors may include magnesium oxide, lead
oxide, calcium oxide, calcium hydroxide, dibasic lead phosphite,
zinc oxide, barium carbonate, strontium hydroxide, calcium
carbonate, hydrotalcite, alkali stearates, magnesium oxalate, or
combinations thereof. The acid acceptors are preferably used in
amounts ranging from about 1 to about 20 parts per 100 parts by
weight of the polymer.
[0089] A solution or liquid dispersion containing the fluorinated
polymer, and other components described above may be prepared using
a solvent such as ketone (e.g., acetone, methyl ethyl ketone,
methyl isobutyl ketone), ether (e.g., diethyl ether,
tetrahydrofuran), fluorinated solvents (such as inert fluorinated
liquids), and ester (e.g., ethyl acetate, butyl acetate), the
solution or liquid dispersion prepared may be coated on the surface
of a substrate such as paper, fiber, fabric, metal, glass, ceramic,
plastic, wood, and combinations thereof, and the solvent may be
removed by drying. In this way, an article containing a composition
layer and a substrate can be formed.
[0090] In one embodiment, the amorphous fluoropolymer can be cured
to form a fluoroelastomer. Crosslinking of the amorphous
fluoropolymer can be performed generally with a peroxide, a polyol,
or a polyamine cure system (or curative).
[0091] Peroxide curatives include organic or inorganic peroxides.
Organic peroxides are preferred, particularly those that do not
decompose during dynamic mixing temperatures.
[0092] The crosslinking using a peroxide can be performed generally
by using an organic peroxide as a crosslinking agent and, if
desired, a crosslinking aid such as diallyl ether of glycerin,
triallylphosphoric acid, diallyl adipate, diallylmelamine and
triallyl isocyanurate (TAIC), tri(methyl)allyl isocyanurate
(TMAIC), tri(methyl)allyl cyanurate, poly-triallyl isocyanurate
(poly-TAIC), xylylene-bis(diallyl isocyanurate) (XBD), and
N,N'-m-phenylene bismaleimide. Examples of the organic peroxide
include benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide,
2,5-di-methyl-2,5-di-tert-butylperoxyhexane, 2,4-dichlorobenzoyl
peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylchlorohexane,
tert-butyl peroxy isopropylcarbonate (TBIC), tert-butyl peroxy
2-ethylhexyl carbonate (TBEC), tert-amyl peroxy 2-ethylhexyl
carbonate, tert-hexylperoxy isopropyl carbonate, carbonoperoxoic
acid, O,O'-1,3-propanediyl OO,OO'-bis(1,1-dimethylethyl) ester,
tert-butylperoxy benzoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl
peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, laurel
peroxide and cyclohexanone peroxide. Other suitable peroxide
curatives are listed in U.S. Pat. No. 5,225,504 (Tatsu et al.). The
amount of peroxide curing agent used generally will be 0.1 to 5,
preferably 1 to 3 parts by weight per 100 parts of fluoropolymer.
Other conventional radical initiators are suitable for use with the
present disclosure.
[0093] The crosslinking using a polyol is performed generally by
using a polyol compound as a crosslinking agent, a crosslinking aid
such as ammonium salt, phosphonium salt and iminium salt, and a
hydroxide or oxide of a divalent metal such as magnesium, calcium,
or zinc. Examples of the polyol compound include bisphenol AF,
bisphenol A, bisphenol S, dihydroxybenzophenone, hydroquinone,
2,4,6-trimercapto-S-triazine, 4,4'-thiodiphenol, and a metal salt
thereof.
[0094] The crosslinking using a polyamine is performed generally by
using a polyamine compound as a crosslinking agent, and an oxide of
a divalent metal such as magnesium, calcium, or zinc. Examples of
the polyamine compound or the precursor of the polyamine compound
include hexamethylenediamine and a carbamate thereof,
4,4'-bis(aminocyclohexyl)methane and a carbamate thereof, and
N,N'-dicinnamylidene-1,6-hexamethylenediamine.
[0095] This crosslinking agent, crosslinking aid, and
acid-receiving agent composed of a hydroxide, oxide, or the like of
a divalent metal, each may be used in a conventionally known
amount, and the amount used can be appropriately determined by one
skilled in the art while taking into consideration the miscibility
with the fluoropolymer, mechanical strength of the crosslinked
fluoropolymer, profitability and the like. The amount used of each
of these components participating in the crosslinking may be, for
example, about 1 part by mass or more, about 5 parts by mass or
more, about 10 parts by mass or more, or about 15 parts by mass or
more, and about 60 parts by mass or less, about 40 parts by mass or
less, about 30 parts by mass or less, or about 20 parts by mass or
less, per 100 parts by mass of the fluoropolymer. The total amount
of the components participating in the crosslinking may be, for
example, about 1 part by mass or more, about 5 parts by mass or
more, or about 10 parts by mass or more, and about 60 parts by mass
or less, about 40 parts by mass or less, or about 30 parts by mass
or less, per 100 parts by mass of the fluoropolymers.
[0096] Exemplary embodiments of the present disclosure include, but
are not limited to the following:
Embodiment 1
[0097] An aqueous dispersion comprising a fluorinated polymer
comprising:
an aqueous continuous phase; and a plurality of fluorinated polymer
particles, wherein the fluorinated polymer particle comprises
interpolymerized units of (i) a fluorinated terminal alkene monomer
and (ii) a tertiary amine-containing fluorinated monomer comprising
at least one of a vinyl amine, a substituted vinyl amine, an allyl
amine, a substituted allyl amine, and combinations thereof.
Embodiment 2
[0098] The aqueous dispersion of embodiment 1, further comprising a
hydrocarbon surfactant.
Embodiment 3
[0099] The aqueous dispersion of embodiment 2, wherein the aqueous
dispersion comprises at least 2 wt % and at most 10 wt % of the
hydrocarbon surfactant.
Embodiment 4
[0100] The aqueous dispersion of any one of the previous
embodiments, wherein the aqueous dispersion comprises 5 to 60% by
weight of the plurality of fluorinated polymer particles.
Embodiment 5
[0101] The aqueous dispersion of any one of the previous
embodiments, wherein the fluorinated terminal alkene monomer is
tetrafluoroethylene.
Embodiment 6
[0102] The aqueous dispersion of any one embodiments 1-2, wherein
the fluorinated terminal alkene monomer comprises at least one of
tetrafluoroethylene; vinylidene fluoride: hexafluoropropylene;
chlorotrifluoroethylene; 2,3,3,3-tetrafluoropropene; and
combinations thereof.
Embodiment 7
[0103] The aqueous dispersion of any one of the previous
embodiments, wherein the tertiary amine-containing fluorinated
monomer is of the formula:
##STR00013## [0104] where X.sup.1 is selected from H or F; X.sup.2
is selected from H or F; X.sup.3 is selected from H or F; and each
Rr group are (i) independently selected from a linear or branched
perfluorinated alkyl group comprising 1 to 8 carbon atoms and
optionally comprising at least one catenated O or N atom; or (ii)
bonded together to form a ring structure comprising 4 to 8 carbon
atoms and optionally comprising at least one catenated O or N
atom.
Embodiment 8
[0105] The aqueous dispersion of any one of embodiments 1-6,
wherein the tertiary amine-containing fluorinated monomer is of the
formula:
##STR00014## [0106] where X.sup.1 is selected from H, F, or
CF.sub.3; X.sup.2 is selected from H or F; X.sup.3 is selected from
H, F, or a C1-C4 alkyl or a C1-C4 fluoroalkyl, wherein at least one
of X.sup.1, X.sup.2 or X.sup.3 is not H or F; and each Rf group are
(i) independently selected from a linear or branched perfluorinated
alkyl group comprising 1 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; or (ii) bonded
together to form a ring structure comprising 4 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom.
Embodiment 9
[0107] The aqueous dispersion of any one of the previous
embodiments, wherein the tertiary amine-containing fluorinated
monomer comprises at least one of:
##STR00015## ##STR00016##
and combinations thereof.
Embodiment 10
[0108] The aqueous dispersion of any one of embodiments 1-6,
wherein the tertiary amine-containing fluorinated monomer is of the
formula:
##STR00017## [0109] where X.sup.1, X.sup.2, and X.sup.3 are
independently selected from H, or F; [0110] Y.sup.1 is H or F;
Y.sup.2 is For CF.sub.3; and each R.sub.f group are (i)
independently selected from a linear or branched perfluorinated
alkyl group comprising 1 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; or (ii) bonded
together to form a ring structure comprising 4 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom.
Embodiment 11
[0111] The aqueous dispersion of any one of embodiments 1-6,
wherein the tertiary amine-containing fluorinated monomer is of the
formula:
##STR00018## [0112] where X.sup.1, X.sup.2, and X.sup.3 are
independently selected from H, F, or CF.sub.3; [0113] Y.sup.1 is H
or F; Y.sup.2 is F or CF.sub.3; wherein at least one of X.sup.1,
X.sup.2, or X.sup.3 is CF.sub.3; and [0114] each R.sub.f group are
(i) independently selected from a linear or branched perfluorinated
alkyl group comprising 1 to 8 carbon atoms and optionally
comprising at least one catenated O or N atom; or (ii) bonded
together to form a ring structure comprising 4 to 8 carbon atoms
and optionally comprising at least one catenated O or N atom.
Embodiment 12
[0115] The aqueous dispersion of any one of embodiments 1-6,
wherein the tertiary amine-containing fluorinated monomer comprises
at least one of:
##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023##
##STR00024##
and combinations thereof.
Embodiment 13
[0116] The aqueous dispersion of any one of the previous
embodiments, wherein the hydrocarbon surfactant is non-ionic or
anionic.
Embodiment 14
[0117] The aqueous dispersion of any one of the previous
embodiments, wherein the fluorinated polymer particles of the
plurality of fluorinated polymer particles have an average particle
diameter of 30 to 400 nm.
Embodiment 15
[0118] The aqueous dispersion of any one of the previous
embodiments, further comprising a fluorinated liquid.
Embodiment 16
[0119] The aqueous dispersion of any one of the previous
embodiments, wherein the fluorinated polymer particle comprises a
cure-site selected from Br, I, nitrile, and combinations
thereof.
Embodiment 17
[0120] The aqueous dispersion of any one of the previous
embodiments, wherein the fluorinated polymer particle is
semi-crystalline.
Embodiment 18
[0121] The aqueous dispersion of embodiment 15, wherein the
fluorinated polymer particle has a melting point no greater than
325.degree. C.
Embodiment 19
[0122] The aqueous dispersion of any one of the previous
embodiments, wherein the fluorinated polymer particle is
amorphous.
Embodiment 20
[0123] A polymer comprising: interpolymerized units of (i) a
fluorinated terminal alkene monomer and (ii) a tertiary
amine-containing fluorinated monomer comprising at least one of a
vinyl amine, a substituted vinyl amine, an allyl amine, a
substituted allyl amine, and combinations thereof; wherein the
polymer is amorphous or is semi-crystalline with a melting point no
greater than 325.degree. C.
Embodiment 21
[0124] The polymer of embodiment 20, wherein the polymer comprises
an integrated absorbance ratio less than 0.1.
Embodiment 22
[0125] The polymer of any one of embodiment 20-21, wherein the
polymer is amorphous.
Embodiment 23
[0126] The polymer of any one of embodiment 20-21, wherein the
polymer has a Tg between -50.degree. C. and 150.degree. C.
Embodiment 24
[0127] An article comprising the polymer of any one of embodiments
20-23.
Embodiment 25
[0128] A coating composition comprising the polymer of any one of
embodiments 20-23.
Embodiment 26
[0129] A method of coating a substrate comprising: contacting the
aqueous dispersion of any one of embodiments 1-19 onto a
substrate.
Embodiment 27
[0130] The method of embodiment 26, wherein the substrate is
comprises at least one of metal, glass, wood, ceramic, fabric,
plastic, and combinations thereof.
Embodiment 28
[0131] A method of making a fluoropolymer comprising: polymerizing
in an aqueous continuous phase. (i) a fluorinated terminal alkene
monomer and (ii) a tertiary amine-containing fluorinated monomer
comprising at least one of a vinyl amine, a substituted vinyl
amine, an allyl amine, a substituted allyl amine, and combinations
thereof.
Embodiment 29
[0132] The method of making a fluoropolymer further comprising a
hydrocarbon surfactant.
EXAMPLES
[0133] Unless otherwise noted, all chemicals used in the examples
can be obtained from Sigma-Aldrich Corp. (Saint Louis, Mo.).
[0134] The following abbreviations are used in this section:
NMR=nuclear magnetic resonance, ml=milliliters, L=iters, s=seconds,
min=minutes, g=grams, .mu.m=micrometers, mm=millimeters, m=meters,
ppm=parts per million, mol=mole, w %=percent by weight, d50=average
diameter
[0135] Characterization Methods
[0136] The indicated results were obtained using the following test
methods, unless otherwise noted.
[0137] Solid Content
[0138] Solid content was determined gravimetrically by placing
samples of the dispersions on a heated balance and recording the
mass before and after evaporation of solvent. The solid content was
the ratio of the initial mass of the sample and the mass of the
sample when the mass did not decrease further with continued
heating. See ISO 12086:2006.
[0139] Particle Size
[0140] The size of particles in the polymer dispsersions was
determined by dynamic light scattering using an instrument
available from Malvern, Worchestershire, UK, under the trade
designation "Zetasizer 1000HSA," following a similar procedure as
described in DIN ISO 13321:2004-10. The reported average particle
size was the z-average. Prior to the measurements, the polymer
latices as yielded from the polymerizations were diluted with 0.01
mol/L NaCl solution, available from Riedel-de Haen. The measurement
temperature was 20.degree. C. in all cases.
[0141] Melting Point
[0142] The melting point of the polymer was determined using
differential scanning calorimetry following a similar procedure to
that described in ASTM D4591-07 (2012) using a PerkinElmer Pyris 1
DSC (Waltham, Mass.) under nitrogen flow with a heating rate of
10.degree. C./min. The reported melting points relate to the
melting peak maximum.
[0143] Critical Film Thickness (CFT)
[0144] A container was filled with the test dispersion. Foam,
ifpresent, was removed using a pipette. A degreased aluminum plate
(19 mm.times.4 mm.times.4 mm) was dipped in the dispersion and
dried with the plate hanging at an angle of 450. The plate was
allowed to dry for 5 min, after which it was heated at 200.degree.
C. for 10 min. The plate was cooled and the coating was evaluated
for cracks using a microscope. The maximum crack-fee thickness was
measured using a thickness gauge (MiniTest 4000 available from
ElectroPhysik, Cologne, Germany).
[0145] Viscosity
[0146] The viscosity of the dispersion was measured using a
rheometer (DV-III using software available under the trade
designation "RHEOCALC 3.2" from Brookfield AMETEK. Middleboro,
Mass.), spindle 86, at temperatures of 20.degree. C. and 40.degree.
C. The shear rate was 20 l/s.
Example 1 (EX-1)
[0147] A 4 L polymerization kettle was charged with 2.6 L of
H.sub.2O and 65 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.-
4 (which can be prepared as described in Compound 12 of U.S. Pat.
No. 7,671,112 Hintzer, et al.) and stirred with an agitator speed
of 320 rpm. The kettle was heated to 70.degree. C. The kettle was
then charged with VDF until a pressure of 14.0 bar was reached. The
polymerization was initiated by adding 4 g of APS (ammonium
persulfate, (NHI.sub.4)S.sub.2O.sub.8). 202 g of VDF and 109 g of
perfluoro-N-vinyl morpholine (NVM, which can be synthesized as
described in T. Abe, et al. Chem. Lett. 1989, 905) were added
continuously over 120 min. The reaction was stopped. The resulting
polymer dispersion had a solid content of 10 wt %. The average
particle size of the polymer in the dispersion was 107 nm. 281 g of
polymer were isolated by coagulation. A melting point of
158.degree. C. was found.
Example 2 (EX-2)
[0148] A 4 L polymerization kettle was charged with 2.6 L of
H.sub.2O and 130 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub-
.4 and stirred at an agitator speed of 320 rpm. The kettle was
heated to 70.degree. C. The kettle was then charged with VDF until
a pressure of 14.0 bar was reached. The polymerization was
initiated by adding 4 g of APS. 82 g of VDF and 100 g of NVM were
added continuously over 72 min. The reaction was stopped. The
resulting polymer dispersion had a solid content of 5 wt %. The
average particle size of the polymer in the dispersion was 60 nm.
146 g of polymer were isolated by coagulation. A melting point of
156.degree. C. was found.
Example 3 (EX-3)
[0149] A 4 L polymerization kettle was charged with 2.6 L of
H.sub.2O, 130 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.4,
and 10 g of NVM and stirred at an agitator speed of 320 rpm. The
kettle was heated to 70.degree. C. The kettle was then charged with
TFE until 14.0 bar was reached. The polymerization was initiated by
adding 4 g of APS. 230 g of TFE and 80 g of NVM were added
continuously over 72 min. The reaction was stopped. The resulting
polymer dispersion had a solid content of 9 wt %. The average
particle size of the polymer in the dispersion was 35 nm. 280 g of
polymer were isolated by coagulation. A melting point of
323.degree. C. was found.
Example 4 (EX-4)
[0150] A 4 L-polymerization kettle was charged with 2.6 L of
H.sub.2O, 130 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.4,
5 g of perfluoro N-vinylpyrolidine (NVP, which can be synthesized
as described in T. Abe, et al. Chem. Lelt. 1989, 905) and stirred
at an agitator speed of 320 rpm. The kettle was heated up to
90.degree. C. Then VDF was charged until 14.0 bar was reached. The
polymerization was initiated by adding 1 g of APS. Over 125 min.
200 g of VDF, 89 g perfluoro N-vinylpyrolidine (NVP) and 0.8 g of
APS were added continuously. The reaction was stopped. The
resulting polymer dispersion had a solid content of 10 wt %. The
average particle size of the polymer in the dispersion was 102 nm.
The polymer was isolated by freeze coagulation. A melting point of
150.degree. C. was found. The MFI was 0.07 g/10 min (230.degree.
C., 5 kg).
Example 5 (Ex-5)
[0151] A 4 L-polymerization kettle was charged with 2.6 L of
H.sub.2O, 130 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.4,
9 g of perfluoro N-vinylpyrolidine (NVP) and stirred at an agitator
speed of 320 rpm. The kettle was heated up to 90.degree. C. Then
TFE was charged until 14.0 bar was reached. The polymerization was
initiated by adding 1 g of APS. Over 154 min, 220 g of TFE, 60 g of
NVP and 1.3 g of APS were added continuously. The reaction was
stopped. The polymer was isolated by freeze coagulation. A melting
point of 319.degree. C. was found.
Example 6 (Ex-6)
[0152] A 4 L-polymerization kettle was charged with 2.6 L of
H.sub.2O, 130 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.4,
6 g of perfluoro N-allylmorpholine (NAM, which can be synthesized
as described in JP 01070444A (Abe); and JP 0107445A (Abe)) and
stirred at an agitator speed of 320 rpm. The kettle was heated up
to 90.degree. C. Then VDF was charged until 14.0 bar was reached.
The polymerization was initiated by adding 1 g of APS. Over 84 min,
200 g of VDF, 99 g perfluoro N-allylmorpholine (NAM) and 1.4 g of
APS were added continuously. The reaction was stopped. The
resulting polymer dispersion had a solid content of 11 wt %. The
average particle size of the polymer in the dispersion was 65 nm.
The polymer was isolated by freeze coagulation. A melting point of
151.degree. C. was found. The MFI was 0.30 g/10 min (230.degree.
C., 5 kg).
Example 7 (Ex-7)
[0153] A 4 L-polymerization kettle was charged with 2.6 L of
H.sub.2O, 130 g of
CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.4,
11 g of NAM and stirred at an agitator speed of 320 rpm. The kettle
was heated up to 90.degree. C. Then TFE was charged until 6.0 bar
was reached. The polymerization was initiated by adding 1 g of APS.
Over 90 min, 100 g of TFE, 30 g perfluoro N-allylmorpholine (NAM)
and 5 g of APS were added continuously. The reaction was stopped.
The resulting polymer dispersion had a solid content of 5 wt %. The
average particle size of the polymer in the dispersion was 61 nm.
The polymer was isolated by freeze coagulation. A melting point of
319.degree. C. was found.
Example 8
[0154] 20 g of a surfactant (90%, available under the trade
designation "TERGITOL TMN-100X" available from Dow Chemical Co.,
Midland, Mich.) was added to 2.3 kg of the latex dispersion from
Ex-4. The pH was then adjusted with ammonia solution (25 wt %) to
pH=9.0. Additionally, 500-600 g of diluted TERGITOL TMN-100.times.
aqueous solution (25% by mass) was added and the latex dispersion
was heated for 8 h at 75-95.degree. C. After cooling, two phases
were obtained and the upper phase was removed. The pH value of the
concentrated dispersion (i.e. the lower phase) was then adjusted
with ammonia solution to pH=9.5. The resulting solid content of the
concentrated dispersion was 36 wt % for the copolymer latex and had
a viscosity of 20.7 and 34.1 mPas (20.degree. C. and 40.degree. C.,
respectively).
[0155] The concentrated dispersion was then dip coated onto an
aluminum plate as described in the CFT method described above. The
CFT was 14 micrometers.
Example 9
[0156] 26 g of a surfactant (90%, available under the trade
designation "TERGITOL TMN-100X" available from Dow Chemical Co.,
Midland, Mich.) was added to 2.3 kg of the latex dispersion from
Ex-6. The pH was then adjusted with ammonia solution (25 wt %) to
pH=9.0. Additionally, 500-600 g of diluted TERGITOL TMN-100.times.
aqueous solution (25% by mass) was added and the latex dispersion
was heated for 8 h at 75-95.degree. C. After cooling, two phases
were obtained and the upper phase was removed. The pH value of the
concentrated dispersion (i.e. the lower phase) was then adjusted
with ammonia solution to pH=9.5. The resulting solid content of the
concentrated dispersion was 47 wt % for the copolymer latex.
[0157] The concentrate dispersion then was treated with an anion
exchange resin (available under the trade designation "AMBERJET
4200 CL" from Dow Chemical Co, Midland, Mich.) to reduce the
concentration of the fluorinated emulsifier
(CF.sub.3--O--CF.sub.2CF.sub.2CF.sub.2--O--CHFCF.sub.2--COONH.sub.4).
After ion exchange, the final concentration of the fluorinated
emulsifier was 34 ppm. The resulting dispersion had had a viscosity
of 117 and 399 mPas (20.degree. C. and 40.degree. C.,
respectively).
Example 10
[0158] A 50 wt % solution of TERGITOL TMN-100.times. was added to 1
liter of latex from EX-7 to obtain a dispersion with 10 wt %
nonionic surfactant based on fluoropolymer solids. The mixture then
was thermally up-concentrated by using vacuum-distillation (a
rotary evaporated) with a 70.degree. C. water bath and pulling a
300 mbar vacuum to obtain a polymer dispersion having a 32 wt %
solid content.
[0159] Foreseeable modifications and alterations of this invention
will be apparent to those skilled in the art without departing from
the scope and spirit of this invention. This invention should not
be restricted to the embodiments that are set forth in this
application for illustrative purposes. To the extent that there is
any conflict or discrepancy between this specification as written
and the disclosure in any document mentioned or incorporated by
reference herein, this specification as written will control.
* * * * *