U.S. patent application number 11/877644 was filed with the patent office on 2009-02-26 for fluoropolymer low reflecting layers for plastic lenses and devices.
Invention is credited to ANDREW EDWARD FEIRING, SAWATO IWATO, MUREO KAKU, TATSUHIRO TAKAHASHI, RONALD EARL USCHOLD, ROBERT CLAYTON WHELAND.
Application Number | 20090054594 11/877644 |
Document ID | / |
Family ID | 22415356 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090054594 |
Kind Code |
A1 |
FEIRING; ANDREW EDWARD ; et
al. |
February 26, 2009 |
FLUOROPOLYMER LOW REFLECTING LAYERS FOR PLASTIC LENSES AND
DEVICES
Abstract
A one or two layer coating system has been developed for plastic
substrates. The one coating system low reflective layer consists of
a fluorinated copolymer having the formula: VF2/TFE/HFP, VF2/HFP or
VF2/TFE/PMVE. In the two coating system, the upper coating layer
consists of TFE/HFP, VF.sub.2/TFE/HFP, or TFE/Perfluorodioxole, and
the lower coating layer consists of VF.sub.2/TFE/HFP, VF/TFE/HFP,
VAc/TFE/HFIB, or TFE graft to PVOH.
Inventors: |
FEIRING; ANDREW EDWARD;
(WILMINGTON, DE) ; TAKAHASHI; TATSUHIRO;
(YAMAGATA, JP) ; KAKU; MUREO; (TOCHIGI, JP)
; USCHOLD; RONALD EARL; (WEST CHESTER, PA) ;
WHELAND; ROBERT CLAYTON; (WILMINGTON, DE) ; IWATO;
SAWATO; (TOKYO, JP) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY;LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1122B, 4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Family ID: |
22415356 |
Appl. No.: |
11/877644 |
Filed: |
October 23, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10355202 |
Jan 30, 2003 |
7297398 |
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11877644 |
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Current U.S.
Class: |
525/199 |
Current CPC
Class: |
C09D 127/20 20130101;
C09D 127/16 20130101; C09D 127/12 20130101; C08F 214/28 20130101;
Y10T 428/265 20150115; Y10T 428/31504 20150401; C09D 127/18
20130101; C08J 2427/00 20130101; C08J 7/0427 20200101; C08J 7/043
20200101; C08F 214/18 20130101; C09D 131/04 20130101; Y10T
428/31935 20150401; Y10T 428/3154 20150401; C08L 2205/02 20130101;
Y10T 428/31786 20150401; Y10T 428/31507 20150401; C08F 214/26
20130101; C09D 127/12 20130101; C08L 2666/04 20130101 |
Class at
Publication: |
525/199 |
International
Class: |
C08L 27/18 20060101
C08L027/18 |
Claims
1-12. (canceled)
13. A composition prepared by the polymerization of vinyl acetate
(VAc, CH.sub.3--C(O)--OCH.dbd.CH.sub.2), tetrafluoroethylene
(CF.sub.2.dbd.CF.sub.2), and hexafluoroisobutylene
((CF.sub.3)2C.dbd.CH.sub.2).
14-23. (canceled)
Description
FIELD OF INVENTION
[0001] The present invention relates to fluoropolymer coated
plastics. More specifically, it relates to fluoropolymer coated
plastics having good adhesion, low reflective properties, and water
and oil repellency.
TECHNICAL BACKGROUND
[0002] Much work has been done concerning low reflective plastics,
particularly for plastic lenses and optical devices. One method
used is vapor disposition of oxidized metal on the surface of the
plastic. However, this method uses a batch process and when the
substrate is large, the productivity becomes low. Another way is to
apply a coating of fluoropolymer solutions. The coating is done by
a dipping process and is applicable for large substrates with high
productivity. Though fluoropolymers have low reflective indexes,
they also have very poor adhesion with plastic substrates.
Improvement in the adhesion between fluoropolymers and substrate
plastics has been long sought. The purpose of this invention is to
provide the technology for low reflective index and good adhesion
using fluoropolymer solutions.
SUMMARY OF THE INVENTION
[0003] The one layer coating system provided by the present
invention consists of a fluorinated copolymer having the
formula:
VF.sub.2/TFE/HFP
wherein the molar ratio of Tetrafluoroethylene (TFE) to
Hexafluoropropylene (HFP) is between 0.1 and 1.9, and the VF.sub.2
content is 12 to 60 mole %. Preferably the VF.sub.2 content is 12
to 50 mole % for PMMA substrates and 18 to 50 mole % for PC, PET,
and PS substrates. More preferred is where the molar ratio of TFE
to HFP is between 0.9 and 1.9, and the VF.sub.2 content is
preferably 12 to 50 mole % for Polymethylmethacrylate (PMMA)
substrates and 18 to 50 mole % for Polycarbonate (PC),
Polyethyleneterephthalate (PET), and Polysulfone (PS)
substrates.
[0004] Also preferred is where the VF.sub.2 content is greater than
50 mole % to 60 mole %; more preferred is where the substrate is
PMMA, PC, PET or glass.
[0005] A one layer coating system is also provided by the present
invention comprising a fluorinated copolymer having the formula
VF.sub.2/HFP
wherein the VF.sub.2 content is about 40-80 mole %. Preferably, the
VF.sub.2 content is about 40-50 mole % and the substrate is PMMA.
Also preferably, the VF.sub.2 content is about 70-80 mole % and the
substrate is glass.
[0006] A one layer coating system is also provided by the present
invention comprising a fluorinated copolymer having the formula
VF.sub.2/TFE/PMVE
wherein the VF.sub.2 content is about 18-60 mole % and the TFE/PMVE
mole ratio is 0.1-1.9. Preferably the VF.sub.2 content is about
30-35 mole %, the TFE/PMVE mole ratio is about 0.2-0.3 and the
substrate is PMMA.
[0007] In the case of the present invention the two-layer coating
system developed for PMMA, PC, PET, and PS substrates comprises an
upper layer selected from the group consisting of: [0008] a)
poly(TFE/HFP) and poly(VF.sub.2/TFE/HFP), wherein the molar ratio
of TFE to HFP is between about 0.3 and 1.9 and, in the case of the
VF.sub.2/TFE/HFP terpolymer, the concentration of VF.sub.2 is about
19 mole %; and [0009] b) poly(TFE/perfluoro-2,2-dimethyldioxole)
wherein the concentration of the perfluorodimethyldioxole is
between 60 and 90 mole %; and a lower coating layer selected from
the group consisting of: [0010] a) poly(VF.sub.2/TFE/HFP) wherein
the ratio of TFE to HFP is between about 0.3 and 1.9 and the
concentration of VF.sub.2 is between about 18 and 60 mole % on PMMA
substrates and between about 12 and 40 mole % on PC, PET, and PS
substrates; [0011] b) poly(VF/TFE/HFP) wherein the ratio of TFE to
HFP is between about 2.1 and 0.9 and the concentration of VF is
between about 42 and 58 mole %; [0012] c) poly(VAc/TFE/HFIB)
wherein the concentration of VAc is between, 36 and 69 mole % and
the concentration of HFIB is between 14 and 52 mole %; and [0013]
d) TFE graft to PVOH wherein about 46 mole % TFE has been grafted
to the PVOH.
[0014] More preferred is where the ratio of TFE to HFP is between
about 0.9 and 1.9 in both the lower and upper layer, and wherein
the concentration of VF.sub.2 is between about 12 and 40 mole %
when PC, PET, and PS substrates are utilized.
[0015] In the one layer coating system of the present invention,
the thickness of the coating is preferably between about 10 and
1000 nm, more preferably, between about 30 and 120 nm, and most
preferably between about 70 and 120 nm.
[0016] In the two coat system, the thickness of the upper layer is
preferably between 10 and 1000 nm. More preferably, it is between
30 and 120 nm and most preferably, it is between 70 and 120 nm.
[0017] Another aspect of the invention is a new fluoropolymer
composition prepared by the polymerization of vinyl acetate (VAc,
CH.sub.3--C(O)--OCH.dbd.CH.sub.2), tetrafluoroethylene (TFE,
CF.sub.2.dbd.CF.sub.2), and hexafluoroisobutylene (HFIB,
(CF.sub.3).sub.2C.dbd.CH.sub.2).
DETAILED DESCRIPTION OF THE INVENTION
[0018] Both one layer and two layer systems have been found that
afford low reflection coatings on optically clear plastic
substrates. Preferred substrates are PMMA, PC, PET, and PS, and
glass.
[0019] The one layer coating system provided by the present
invention consists of a fluorinated copolymer having the
formula
VF.sub.2/TFE/HFP
wherein the molar ratio of TFE to HFP is between 0.1 and 1.9 and
the VF.sub.2 content is preferably 12 to 60 mole % for PMMA
substrates and 18 to 60 mole % for PC, PET, and PS substrates.
These compositions balance the high fluorine content needed for low
reflection, the high HFP content needed for optical clarity, and a
sufficient VF.sub.2 content to afford good adhesion to the
substrate. More preferred is where the molar ratio of TFE to HFP is
between 0.9 and 1.9, and the VF.sub.2 content is preferably 12 to
60 mole % for PMMA substrates and 18 to 60 mole % for PC, PET, and
PS substrates. Also preferred is where the VF.sub.2 content is 50
to 60 mole % for glass substrates.
[0020] Another embodiment of the one layer system comprises a
fluorinated copolymer having the formula
VF.sub.2/HFP
wherein the VF.sub.2 is about 40-60 mole %. Preferably, the
VF.sub.2 content is about 43 mole % and the substrate is PMMA.
[0021] Another embodiment of the one layer system comprises a
fluorinated copolymer having the formula
VF.sub.2/TFE/PMVE
wherein the VF.sub.2 content is about 18-60 mole % and the TFE/PMVE
mole ratio is 0.1-1.9. Preferably the VF.sub.2 content is about
30-35 mole %, the TFE/PMVE mole ratio is about 0.2-0.3 and the
substrate is PMMA.
[0022] Although many polymers have a high enough fluorine content
to perform well as a low reflection coating, they often fail
because of inadequate bonding to substrates such as PMMA, PC, PET,
and PS. This adhesion problem has been solved by going to systems
in which a lower adhesive coat bonds a low-reflective top coat to
the substrate. In the case of the present invention, the two-layer
coating system developed for PMMA, PC, PET, and PS substrates
consists of fluoropolymers having the formulas
Upper Coating Layer
[0023] Poly(TFE/HFP) and poly(VF.sub.2/TFE/HFP), wherein the molar
ratio of TFE to HFP is between about 0.3 and 1.9 and, in the case
of the VF.sub.2/TFE/HFP terpolymer, the concentration of VF.sub.2
is about 19 mole % [0024] or [0025]
poly(TFE/perfluoro-2,2-dimethyldioxole) wherein the concentration
of the perfluorodimethyldioxole is between 60 and 90 mole %
Lower Coating Layer
[0025] [0026] Poly(VF.sub.2/TFE/HFP) wherein the ratio of TFE to
HFP is between about 0.3 and 1.9 and the concentration of VF.sub.2
is between about 18 and 60 mole % on PMMA substrates and between
about 12 and 50 mole % on PC, PET, and PS substrates [0027] or
[0028] Poly(VF/TFE/HFP) wherein the ratio of TFE to HFP is between
about 2.1 and 0.9 and the concentration of VF is between about 42
and 58 mole % [0029] or [0030] Poly(VAc/TFE/HFIB) wherein the
concentration of VAc is between 36 and 69 mole % and the
concentration of HFIB is between 14 and 52 mole % [0031] or [0032]
A TFE graft to PVOH wherein about 46 mole % TFE has been
grafted.
[0033] More preferred is where the ratio of TFE to HFP is between
about 0.9 and 1.9 in both the lower and upper layer, and wherein
the concentration of VF.sub.2 is between about 12 and 40 mole %
when PC, PET, and PS substrates are utilized.
[0034] The purpose of the lower layer in the present invention is
to bond highly-fluorinated, low-reflection polymers to
higher-reflection, hydrocarbon-polymer substrates. In order to be
an effective adhesive agent, the polymer used for the adhesive
layer combines perfluorocarbon monomers such as TFE and HFP with
either partially fluorinated or hydrocarbon comonomers such as
VF.sub.2, HFIB, and VAc.
[0035] In the one layer coating system of the present invention,
the coating needs to be thicker than about 10 nm in order to
observe a significant reduction in reflectivity. While thicknesses
greater than 10 nm work well, practical problems eventually arise
as the coating is made thicker. For example, above about 1000 nm,
thickness variation can become a problem, and, if the coating
polymer is expensive, economics start to be prohibitive. Thus, in
the one layer coating system of the present invention, the
thickness of the coating is preferably between about 10 and 1000
nm, more preferably, between about 120 and 300 nm, most preferably,
between about 70 and 120 nm.
[0036] In the two layer coating system of the present invention the
thickness of the upper layer can be between 10 and 1000 nm. More
preferably, it is between about 30 and 120 nm, most preferably
between about 70 and 120 nm. The coating process for the present
invention can include any process known in the art, including but
not limited to dipping, spray, or spin coating method using
polymer.
[0037] Another aspect of the invention is a new fluoropolymer
composition prepared by the copolymerization of vinyl acetate (VAc,
CH.sub.3--C(O)--OCH.dbd.CH.sub.2), tetrafluoroethylene (TFE,
CF.sub.2.dbd.CF.sub.2), and hexafluoroisobutylene (HFIB,
(CF.sub.3).sub.2C.dbd.CH.sub.2). The polymer can be produced using
any free-radical polymerization method known in the art, including
but not limited to bulk, solution or dispersion polymerization,
using either nonaqueous or aqueous solvents. A preferred method is
dispersion polymerization. Preferred solvents are water and
tert-butanol/methyl acetate mixture. Dispersing agents can
optionally be used; a preferred initiator is Vazo.RTM.52. The
polymer can further be hydrolyzed, partially or completely, to
provide a vinyl alcohol containing copolymer.
[0038] The polymer can be recovered from the reaction using any
conventional procedure such as filtration, followed by washing and
drying. The polymer product can be readily dissolved in many
solvents such as acetone and used for casting films and surface
coatings having the advantageous properties of fluoropolymers. One
particular use is for preparing coatings having low reflective
properties.
[0039] The coatings can be prepared using any method known in the
art. Suitable solvents used for preparing the coatings are those
which dissolve the coating composition but are inert to the
substrate being coated. Preferred solvents include fluorosolvents
such as Fluorinert.RTM. (3M Electronic Materials, St. Paul, Minn.),
Vertrel.RTM. (E. I. DuPont de Nemours, Wilmington, Del.) or
Novec.RTM. (3M Electronic Materials, St. Paul, Minn.), and ketone
solvents such as methyl isobutyl ketone or acetone, isobutyl
acetate, and combination of two or more thereof.
[0040] The following non-limiting Examples are meant to illustrate
the invention but are not intended to limit it in any way.
Materials and Methods
[0041] The following definitions are used herein and should be
referred to for claim interpretation. [0042] APS--Ammonium
persulfate [0043] HFIB--Hexafluoroisobutylene,
(CF.sub.3).sub.2C.dbd.CH.sub.2 [0044] HFP--Hexafluoropropylene,
CF.sub.2.dbd.CF--CF.sub.3 [0045] PC--Polycarbonate [0046]
PET--Polyethyleneterephthalate [0047] PMMA--Polymethylmethacrylate
[0048] PMVE--Perfluoromethylvinylether [0049] PVOH--Polyvinyl
alcohol [0050] PS--Polysulfone [0051] Teflon.RTM.
AF--TFE/Perfluoro-2,2-dimethyldioxole copolymer [0052]
TFE--Tetrafluoroethylene, CF.sub.2.dbd.CF.sub.2 [0053] VAc--Vinyl
acetate, CH.sub.3--C(O)--OCH.dbd.CH.sub.2 [0054] VF--Vinyl
fluoride, CH.sub.2.dbd.CHF [0055] VF.sub.2--Vinylidene fluoride,
CF.sub.2.dbd.CH.sub.2 Unless otherwise indicated, the following
test methods were used:
Method of Measuring Transmission
[0056] Light transmission was measured at 500 nm using a Shimadzu
#UV-3100 Spectrometer. This machine measures a continuous
comparison of a split beam, part of which passes through the
sample.
Adhesion Test Method
[0057] A tool with 10 razor blades separated by a distance of 1 mm
was used to cut the coating down to the plastic substrate, drawing
the razor blade tool first in one direction and then a second time
in a perpendicular direction. This cuts 100 crosshatched squares.
Scotch tape was applied to the crosshatched area with moderate
pressure and pulled off rapidly. Adhesion is scored as the number
of squares out of 100 still attached to the substrate.
[0058] VF2/TFE/HFP terpolymers and TFE/HFP copolymer having HFP
contents in excess of 30 mole % are perhaps most easily made by
polymerization at 14,000 psi and 200-400.degree. C. as described in
U.S. Pat. Nos. 5,478,905 and 5,637,663. VF2/TFE/HFP terpolymers and
the TFE/HFP dipolymers having lower HFP contents as well as
VF2/TFE/PMVE terpolymers can be run under ordinary emulsion and
bulk polymerization methods known in the art, see for instance
Encyclopedia of Polymer Science and Engineering, 1989, Vol. 16, pg.
601-603 and Vol. 7, pg. 257-269, John Wiley & Sons.
Non-crystalline compositions showing good optical clarity and easy
solution coatability were then selected for this invention.
[0059] PVOH grafted with TFE was prepared as in U.S. Pat. No.
5,847,048, hereby incorporated by reference. The polymer contained
about 46 mole % TFE groups grafted to the vinyl alcohol.
[0060] The VAc/TFE/HFIB terpolymers were prepared as described in
Examples 36 to 45 below.
EXAMPLES
Examples 1-9
Comparative Examples 1-3
One Coat Poly(VF.sub.2/TFE/HFP) on PMMA
Preferred Thickness Range
[0061] Solutions, 2 wt % poly(VF.sub.2/TFE/HFP) in Fluorinert.RTM.
FC-75, were made by agitating chunks of the polymer with solvent
for several days at room temperature. PMMA plates measuring 2.5 cm
by 5.0 cm by 3 mm thick were used for testing. The PMMA plates were
coated by lowering the plates into the polymer solution at a rate
of 300 mm/min. and then, 30 seconds later, raising the plates back
out of the solution at 2.5 to 1000 mm/min. After 5-10 minutes air
drying, the plates were dried horizontally for 60 minutes in a
100.degree. C. air oven. Examples are in order of increasing
coating thickness.
TABLE-US-00001 TABLE 1 Single Coat of 18.7/43.3/38.0 mole %
Poly(VF.sub.2/TFE/HFP) on PMMA Thickness (nm) Transmittance (%)
Comp. #1 Uncoated PMMA control 92.1 Comp. #2 5.0 92.8 Example #1
20.0 94.5 Example #2 70.6 96.7 Example #3 76.3 97.7 Example #4 90.2
98.0 Example #5 106.2 96.6 Example #6 133.3 93.2 Example #7 209.2
94.6 Example #8 394.7 95.2 Example #9 572.1 94.4 Comp. #3 2000 not
uniform
[0062] Uncoated PMMA showed 92.1% transmission. Coatings thicker
than 20.0 nm and thinner than 1000 nm gave improved transmission
(>93%) relative to uncoated PMMA. The highest transmissions
(>96%) were shown by coatings .about.30 to 120 nm thick.
Examples 10-13
Comparative Examples 4-5
One Coat Poly(VF.sub.2/TFE/HFP) on PMMA
Preferred VF.sub.2 Content
[0063] Polymer films were prepared as in Examples 1 to 9.
Transmittance and adhesion were measured with the results shown in
Table 2 below which lists Examples and Comparative Examples in
order of increasing VF.sub.2 content.
TABLE-US-00002 TABLE 2 Adhesion by Standard Tape Pull Test Single
Coat Poly(VF.sub.2/TFE/HFP) on PMMA Mole % Adhesion Transmittance
VF.sub.2/TFE/HFP (/100) (%) Comp. #1 Uncoated PMMA -- 92.1 control
Comp. #4 0/57/43 Control 0 97.2 Comp. #5 7.8/60.3/31.8 64 97.5
Example #10 12.6/51.3/36.1 96 97.2 Example #11 18.7/43.3/38.0 99
97.9 Example #12 25.2/42.9/31.9 100 95.1 Example #13 37.4/28.9/33.7
100 96.0
[0064] Simultaneous good adhesion (>96/100) and improved
transmission (>97%) relative to uncoated PMMA were observed for
VF.sub.2/TFE/HFP polymers with 12 to 50 mole % VF.sub.2.
Example 14
[0065] A solution, 2 wt % poly(VF.sub.2/TFE/HFP=46.9/13.5/39.6 mole
%) in Vertrel.RTM. XF, were made by agitating chunks of the polymer
with solvent for several days at room temperature. PMMA plates
measuring 2.5 cm by 5.0 cm by 3 mm thick were used for testing. The
PMMA plates were coated by lowering the plates into the polymer
solution at a rate of 300 mm/min. and then, 30 seconds later,
raising the plates back out of the solution at 50 mm/min. After
5-10 minutes air drying, the plates were dried horizontally for 60
minutes in a 100.degree. C. air oven. Transmittance and adhesion
were measured with the results shown the table below which lists
Examples.
TABLE-US-00003 TABLE 3 Single Coat of 46.9/13.5/39.6 mole %
Poly(VF.sub.2/TFE/HFP) on PMMA Mole %'s Adhesion Transmittance
VF.sub.2TFE/HFP (/100) (%) Example 46.9/13.5/39.6 100 97.4 #14B
Comp. #1 Uncoated PMMA control -- 92.1
[0066] Simultaneous good adhesion (100/100) and improved
transmission (>97%) relative to uncoated PMMA were observed for
VF.sub.2/TFE/HFP=46.9/13.5/39.6 mole % terpolymer.
Examples 15-18
Comparative Examples 6-8
Two Coats, Poly(VF.sub.2/TFE/HFP) and Poly(HFP/TFE), on PMMA
Preferred VF.sub.2 Content
[0067] Solutions, 1 wt % poly(VF.sub.2/TFE/HFP) with 0-40 mole %
VF.sub.2 in Fluorinert.RTM. FC-75, and with 4-55 mole % VF.sub.2 in
acetone were made by agitating chunks of the polymer with solvent
for several days at room temperature. PMMA plates measuring 2.5 cm
by 5.0 cm by 3 mm thick were used for testing. The PMMA plates were
coated by lowering the plates into the polymer solution at a rate
of 300 mm/min. and then, 30 seconds later, raising the plates back
out of the solution at 50 mm/min. After 5-10 minutes air drying,
the plates were dried horizontally for 60 minutes in a 100.degree.
C. air oven. Examples and Comparative Examples are listed in order
of increasing.
[0068] VF.sub.2 content in the poly(VF.sub.2/TFE/HFP) primer coat
was varied. A 57 mole % TFE/43 mole % HFP top coat was used for all
samples with a poly(VF.sub.2/TFE/HFP) primer coat. Transmittance
and adhesion were measured with the results shown in Table 4 below
which lists the Examples and Comparative Examples in order of
increasing thickness.
TABLE-US-00004 TABLE 4 Two Coat, Poly(VF.sub.2/TFE/HFP) and
Poly(HFP/TFE) on PMMA Preferred VF.sub.2 Content Mole % Adhesion
Transmittance VF.sub.2/TFE/HFP (/100) (%) Comp. #1 Uncoated PMMA
control -- 92.1 Comp. #4 0/57/43 Control 0 97.2 Comp. #6
7.8/60.3/31.8 0 97.7 Comp. #7 12.6/51.3/36.1 4 97.5 Example #15
18.7/43.3/38.0 90 97.7 Example #16 49.3/27.7/23.0 100 97.3 Example
#17 52.0/25.9/22.1 98 97.5 Example #18 61.0/21.7/17.3 80 97.4 Comp.
#8 66.2/16.9/16.9 6 97.1
[0069] Good adhesion with increased transmission relative to
uncoated PMMA control was observed when the poly(VF.sub.2/TFE/HFP)
primer layer had VF.sub.2 contents between about 18 and 60 mole
%.
Examples 19-21
Two Coats Both Poly(VF.sub.2/TFE/HFP) on PMMA
Transmittance Independent of VF.sub.2 Content of Primer Coat
[0070] Poly(VF.sub.2/TFE/HFP) samples of different VF.sub.2
content, see Table 5 below, were used for the primer coat.
Solutions, 1 wt % poly(VF.sub.2/TFE/HFP) in acetone, were made by
agitating chunks of the polymer with solvent for several days at
room temperature. PMMA plates measuring 2.5 cm by 5.0 cm by 3 mm
thick were used for testing. The PMMA plates were coated by
lowering the plates into the polymer solution at a rate of 300
mm/min. and then, immediately, raising the plates back out of the
solution at 50 mm/min. After 5-10 minutes air drying, the plates
were dried horizontally for 60 minutes in a 100.degree. C. air
oven. The topcoat, in every instance the same 18.7 mole %
VF.sub.2/43.3 mole % TFE/38.0 mole % HFP terpolymer, was prepared
by the same method.
[0071] Table 5 below lists Examples and Comparative Examples in
order of increasing VF.sub.2 content.
TABLE-US-00005 TABLE 5 Two Poly(VF.sub.2/TFE/HFP) Coats on PMMA
Primer Coat Mole % Adhesion Transmittance VF.sub.2/TFE/HFP (/100)
(%) Comp. #1 Uncoated PMMA -- 92.1 Control Example 19
49.3/27.7/23.0 100 97.5 Example 20 61.0/21.7/17.3 100 97.0 Example
21 66.2/16.9/16.9 100 97.5
[0072] In spite of variation in VF.sub.2 content from 49.3 to 66.2
mole % in the lower layer, overall transmittance is relatively
unaffected. Adhesion is excellent (100/100) for VF.sub.2 contents
from 49.3 to 66.2 mole %.
Examples 22 to 24
Comparative Examples 9-12
One Coat Poly(VF.sub.2/TFE/HFP) on Polycarbonate
Preferred VF.sub.2 Content
[0073] Poly(VF.sub.2/TFE/HFP) terpolymer samples of different
VF.sub.2 content were coated on polycarbonate (PC) sheet using the
method of Example 14. The polycarbonate was manufactured by
Kyoto-Jushi Seiko Co., Ltd. The polycarbonate sheets measured 2.5
cm.times.5.0 cm by 3 mm thick.
[0074] Transmission and adhesion were measured with the results
shown in Table 6 below which lists Examples and Comparative
Examples in order of increasing VF.sub.2 content.
TABLE-US-00006 TABLE 6 Single Poly(VF.sub.2/TFE/HFP) Coat on PC
Mole %'s Adhesion Transmittance VF.sub.2/TFE/HFP (/100) (%) Comp.
#9 Uncoated PC Control -- 87.2 Comp. #10 0/57/43 0 95.2 Comp. #11
7.8/60.3/31.8 0 90.5 Comp. #12 12.6/51.3/36.1 53 94.7 Example #22
18.7/43.3/38.0 70 94.0 Example #23 25.2/42.9/31.9 100 92.0 Example
#24 37.4/28.9/33.7 100 93.8
[0075] VF.sub.2 contents between about 18 and 40 mole % give
improved adhesion (>70/100) relative to HFP/TFE copolymer
(0/100) and improved transmission (>92%) relative to uncoated PC
(87.2%).
Examples 25-28
Comparative Examples 13 to 14
Two Coats on Polycarbonate
Preferred VF.sub.2 Content for Primer
[0076] Poly(VF.sub.2/TFE/HFP) samples of different VF.sub.2
content, see Table 7 below, were used for the primer coat.
Solutions, 1 wt % poly(VF.sub.2/TFE/HFP) in acetone, were made by
agitating chunks of the polymer with solvent for several days at
room temperature. PC plates (Kyoto-Jushi Seiko Co., Ltd.) measuring
2.5 cm by 5.0 cm by 3 mm thick were used for testing. The PC plates
were coated by lowering the plates into the polymer solution at a
rate of 300 mm/min. and then, immediately, raising the plates back
out of the solution at 50 mm/min. After 5-10 minutes air drying,
the plates were dried horizontally for 60 minutes in a 100.degree.
C. air oven.
[0077] The topcoat, in every instance the same 57.0 mole % TFE/43.0
mole % HFP copolymer, was prepared by the same method.
[0078] Table 7 below lists Examples and Comparative Examples in
order of increasing VF.sub.2 content.
TABLE-US-00007 TABLE 7 Two Coats on PC Primer Coat Mole % Adhesion
Transmittance VF.sub.2/TFE/HFP (/100) (%) Comp. #9 Uncoated PC --
87.2 control Comp. #13 0/57/43 control 68 93.8 Comp. #14
7.8/60.3/31.8 12 91.6 Example #25 12.6/51.3/36.1 83 94.2 Example
#26 18.7/43.3/38.0 96 92.3 Example #27 25.2/42.9/31.9 88 93.4
Example #28 37.4/28.9/33.7 97 93.2
[0079] VF.sub.2 contents between about 12 and 40 mole % give
improved adhesion (>83/100) relative to HFP/TFE dipolymer
(68/100) and improved transmittance (>92.3%) relative to
uncoated polycarbonate (87.2%).
Examples 29 to 31
Two Coats on PMMA
Use of Poly(VF/TFE/HFP) as Primer Coat
Preferred VF Content
[0080] A stirred jacketed stainless steel horizontal autoclave of
7.6 L (2 U.S. gal) capacity was used as the polymerization vessel.
The autoclave was equipped with instrumentation to measure
temperature and pressure and with a compressor that could feed
monomer mixtures to the autoclave at the desired pressure. The
autoclave was filled to 55-60% of its volume with deionized water
containing 15 g of Zonyl.RTM. FS-62 surfactant (E.I. DuPont de
Nemours, Wilmington, Del.?) and heated to 90.degree. C. It was then
pressured to 3.1 MPa (450 psig) with nitrogen and vented three
times. The autoclave was precharged with monomers in the desired
ratio, as shown in the table below, and brought to the working
pressure of 3.1 MPa (450 psig). Initiator solution was prepared by
dissolving 2 g APS in 1 L of deionized water. The initiator
solution was fed to the reactor at a rate of 25 mL/min for a period
of five minutes and then the rate was reduced and maintained at 1
mL/min for the duration of the experiment. For Examples 36 and 38
the autoclave was operated in a batch mode. The polymerization was
terminated after a 10% pressure drop was observed by venting the
remaining unconverted monomers and by reducing the autoclave
temperature to room temperature.
[0081] For the 26.2/46.4/27.5 polymer, the autoclave was operated
in a semibatch fashion in which a monomer mixture was added to the
reactor to maintain constant pressure by means of the compressor as
polymerization occurred. The composition of this make-up feed was
different from the precharged mixture, as shown in the table below,
because of the differences in monomer reactivity. The composition
was selected to maintain a constant monomer composition in the
reactor so compositionally homogeneous product was formed. Make-up
monomer feed was admitted to the autoclave, through the compressor,
by means of an automatic pressure regulated valve to maintain
reactor pressure. Monomer feeds were continued until a
predetermined amount to give the final latex solids was fed to the
autoclave. The feed was then stopped and the contents of the
autoclave were cooled and vented.
[0082] In all cases, the polymer latex was easily discharged to a
receiver as a milky homogeneous mixture. Polymer was isolated on a
suction filter after adding 15 g of ammonium carbonate dissolved in
water per liter of latex followed by 70 mL of HFC-4310
(1,1,1,2,3,4,4,5,5,5-decafluoropentane) per liter of latex with
rapid stirring. The filter cake was washed with water and dried in
an air over at 90-100.degree. C.
TABLE-US-00008 TABLE 8 Monomer Monomer Mono- Polymer Precharge
Make-up mer Comp. TFE/VF/ TFE/VF/ Fed Solids Polymer TFE/VF/HFP HFP
(wt %) HFP (wt %) (g) (wt %) (g) (wt %) 15/3/82 750.9 2.1 96.6
38.3/42.8/19 9/3/88 29/46/25 1702 18.3 1063 26.2/46.4/27.5 10/10/80
636.1 2.2 99.7 20.3/57.8/22
[0083] Poly(VF/TFE/HFP) samples of different VF content, see Table
9 below, were used for the primer coat. Solutions, 2 wt %
poly(VF/TFE/HFP) in acetone, were made by agitating chunks of the
polymer with solvent for several days at room temperature. PMMA
plates measuring 2.5 cm by 5.0 cm by 3 mm thick were used for
testing. The PMMA plates were coated by lowering the plates into
the polymer solution at a rate of 300 mm/min. and then,
immediately, raising the plates back out of the solution at 50
mm/min. After 5-10 minutes air drying, the plates were dried
horizontally for 60 minutes in a 100.degree. C. air oven.
[0084] The topcoat, in every instance the same 57 mole % TFE/43
mole % HFP polymer, was prepared by the same method.
[0085] Table 9 below lists Examples in order of increasing VF
content.
TABLE-US-00009 TABLE 9 Two Coats, VF/TFE/HFP Primer, on PMMA Primer
Coat Mole %'s Adhesion Transmittance VF/TFE/HFP (/100) (%) Comp. #1
Uncoated PMMA -- 92.1 control Example #29 42.8/38.3/19.0 99 96.3
Example #30 46.4/26.2/27.5 100 97.3 Example #31 57.8/20.8/22.0 100
96.0
[0086] For VF contents from about 42 to 58 mole %, use of
poly(VF/TFE/HFP) as the primer coat gives excellent transmittance
(>96.0%) relative to uncoated PMMA (92.1%) along with excellent
adhesion (>99/100).
Example 32
Two Coats on PMMA
Use of Graft of TFE to PVOH as Primer Coat
[0087] A poly(vinyl alcohol) to which 46 mole % TFE had been
grafted (PVOH-g-TFE) was used for the primer coat. A solution, 2 wt
% in acetone, was made by agitating chunks of the polymer with
solvent for several days at room temperature. PMMA plates measuring
2.5 cm by 5.0 cm by 3 mm thick were used for testing. The PMMA
plates were coated by lowering the plates into the polymer solution
at a rate of 300 mm/min. and then, immediately, raising the plates
back out of the solution at 50 mm/min. After 5-10 minutes air
drying, the plates were dried horizontally for 60 minutes in a
100.degree. C. air oven.
[0088] The topcoat, an 57 mole % TFE/43 mole % HFP polymer, was
prepared by the same method.
[0089] Table 10 below gives adhesion and transmission results.
TABLE-US-00010 TABLE 10 Two Coats, PVOH-g-TFE Primer, on PMMA
Primer Coat Adhesion Transmittance PVOH-g-TFE (/100) (%) Comp. #1
Uncoated PMMA control -- 92.1 Example #32 46 mole % TFE 97 97.1
[0090] Use of poly(PVOH-g-TFE) as the primer coat gave excellent
transmittance (97.1%) relative to uncoated PMMA (92.1%) along with
excellent adhesion (97/100).
Example 33
Comparative Examples 15-16
One Coat Poly(VF.sub.2/TFE/HFP) on PET
[0091] Coatings were prepared as in Examples 1 to 9. PET sheets
measuring 2.5 by 5.0 cm by 0.12 mm thick were used as substrate.
Transmittance and adhesion were measured with the results shown in
the table below which lists Examples and Comparative Examples.
TABLE-US-00011 TABLE 11 Poly(VF.sub.2/TFE/HFP) Coat on PET Mole %'s
Adhesion Transmittance VF.sub.2/TFE/HFP (/100) (%) Comp. #15
Uncoated PET control -- 85.0 Comp. #16 0/57/43 2 96.0 Example #33
18.7/43.3/38.0 99 96.0
[0092] Uncoated PET showed 85.0% transmission. Simultaneous good
adhesion (>99/100) and improved transmission (>96%) relative
to uncoated PET were observed.
Example 34
Comparative Example 17-18
One Coat Poly(VF.sub.2/TFE/HFP) on Polysulfone
[0093] Coatings were prepared as in Example 1 to 9. Polysulfone
sheets measuring 2.5.times.5.0 cm by 0.05 mm thick were as
substrate. Transmittance and adhesion results are shown in the
table below which lists Examples and Comparative Examples.
TABLE-US-00012 TABLE 12 Single Coat Poly(VF.sub.2/TFE/HFP) on
Polysulfone Mole %'s VF.sub.2/TFE/HFP Adhesion (/100) Transmittance
(%) Comp. #17 Uncoated PS -- 88.5 Comp. #18 0/57/43 97 98.2 Example
#34 18.7/43.3/38.0 100 95.0
[0094] Uncoated polysulfone showed 88.5% transmittance.
Simultaneous good adhesion (>97/100) and improved transmission
(>95%) relative to uncoated polysulfone (88.5%) were
observed.
Example 35
Comparative Example 19
[0095] Two coat polymer films were prepared on PMMA sheet as in
Examples 15-18. A Teflon.RTM. AF top coat was used. Transmittance
and adhesion were measured with the results shown in the table
below which lists the Examples and Comparative Examples.
TABLE-US-00013 TABLE 13 Two Coats, Poly(VF.sub.2/TFE/HFP) and
Teflon .RTM. AF, on PMMA Mole %'s Adhesion Transmittance
VF.sub.2/TFE/HFP (/100) (%) Comp. #1 Uncoated PMMA control -- 92.1
Comp. #19 AF1600 control (no lower 0 98.1 coat) Example #35
49.3/27.7/23.0 100 98.0
[0096] Adhesion was 100/100 for the two coat sheet
(VF.sub.2/TFE/HFP and Teflon.RTM. AF) but only 0/100 for the sheet
with a single coating of Teflon.RTM. AF. This shows that
poly(VF.sub.2/TFE/HFP) is an effective primer that further improves
the adhesion of Teflon.RTM. AF.
[0097] Transmittance at 500 nm was 98.0% for two coat sheet
(VF.sub.2/TFE/HFP and AF) but only 92.1 for uncoated PMMA control.
This shows that Teflon.RTM. AF is an effective top coat that
further improves the transmittance of poly(VF.sub.2/TFE/HFP).
Examples 36-45
[0098] Aqueous Polymerization of VAc/TFE/HFIB. A 1-L stirred
vertical autoclave was charged with a solution of 0.3 g of Plasdone
K-90 (steric stabilizer) and 5 mL isopropanol (chain transfer
agent) in 400 mL of deionized water. Vinyl acetate (126 g, 1.47
mole) and 0.6 g of Vazo.RTM. 52 were added. The vessel was closed,
pressurized to 100 psi with nitrogen and vented twice. The vessel
was pressured to 295 psi with nitrogen as a leak test and vented.
The vessel was cooled to about -4.degree. C., evacuated and charged
with 42 g (0.26 mol) of hexafluoroisobutylene and 42 g (0.42 mol)
of tetrafluoroethylene. With stirring at 750 rpm, the vessel
contents were heated to 70.degree. C. and maintained for 3 hr. The
contents was heated to 85.degree. C. and maintained for 3 hr. After
cooling to room temperature and venting to atmospheric pressure,
the aqueous suspension was removed from the vessel using water as
necessary to rinse. An additional 350 mL of deionized water were
added and the white suspension was heated with stirring on a hot
plate until about 250 mL of solution had evaporated. After cooling
to room temperature, the solid was easily filtered on a sintered
glass funnel and washed with deionized water. It was dried in a
vacuum oven at 90.degree. C. overnight giving 181.8 g (87%) of
white polymer.
[0099] Nonaqueous Polymerization of VAc/TFE/HFIB. A 1-L stirred
vertical autoclave was charged with a solution of 126 g of vinyl
acetate in 110 g of methyl acetate and 200 g of tert-butanol. The
vessel was closed, pressurized to 100 psi with nitrogen and vented
twice. The vessel was pressured to 295 psi with nitrogen as a leak
test and vented. The vessel was cooled to about -4.degree. C.,
evacuated and charged with 63 g of tetrafluoroethylene and 21 g of
HFIB. With stirring at 750 rpm, the vessel contents were heated to
70.degree. C. A solution (25 mL) of 0.2 g Vazo.RTM. 52 in 25 mL
methyl acetate was injected at 5 ml/min. After 3 hr. the vessel
contents were allowed to cool to room temperature and the remaining
gases were vented. The viscous solution was removed from the vessel
by suction, diluting with acetone as necessary to lower solution
viscosity. The polymer solution, further diluted with acetone if
necessary to give a clear solution, was added slowly in 30-45 mL
portions to 16 oz of deionized water and a small amount of ice in a
blender. The precipitated solid was filtered in a sintered glass
funnel. After all polymer had been precipitated the combined solids
were washed in portions with water, filtered and pressed with a
rubber dam. The solid was dried for several hours in a vacuum oven
with a slow nitrogen purge at 110-115.degree. C. The resulting
white solid weighed 141.1 g (67%).
[0100] Table 14 below gives results for polymerizations carried out
by one of the methods listed above.
[0101] Vinyl acetate content was determined by hydrolysis of the
acetate groups using excess of sodium hydroxide in refluxing THF,
followed by titration of excess base by standard hydrochloric acid
solution. GPC analyses were conducted using THF as solvent and
polystyrene standards. Elemental analyses were done by Schwarkkoff
Microanalytical Laboratory. .sup.19F NMR spectra were generally
measured in THF-d6 solutions using TMS and CFC-11 as internal
standards. .sup.19F NMR was used to assign relative amounts of the
two fluorinated monomers from integration of the CF.sub.3 groups of
HFIB at -66 to -70 versus the CF.sub.2 groups from TFE at -110 to
-126.
TABLE-US-00014 TABLE 14 Monomers Weight Ratio Polym. g, Yield Wt. %
F NMR Refractive Inh. GPC Ex. (g) Feed/(Product.sup.a) Solv..sup.b
Reactor (%) VAc (mole %) Index Visc. % F.sup.c Mw/Mn/PD 36 VAc (52)
40:23:37 t-BuOH 400 mL 94.6 (72) 39.0 TFE 31% 1.4111 0.41 38.92
148,000 TFE (30) (39:13:48) MeAc HFIB 69% 84,900 HFIB (49) 1.75 37
VAc (86) 39:23:38 Water 1 L 175.6 (81) 35.5 TFE 28% 1.4169 0.38
36.70 177,000 TFE (50) (36:12:52) PVP HFIB 72% 82,500 HFIB (82)
2.15 38 VAc (103) 49:19:32 Water 1 L 182.5 (87) 50.2 TFE 33% 1.4191
0.52 31.09 252,000 TFE (40) (50:12:38) PVP HFIB 67% 81,800 HFIB
(66) 3.08 39 VAc (126) 60:20:20 Water 1 L 181.8 (87) 58.1 TFE 50%
1.4307 0.79 22.95 349,000 TFE (42) (58:16:26) PVP HFIB 50% 120,000
HFIB (42) 2.90 40 VAc (126) 60:30:10 Water.sup.d 1 L 172.9 (82)
68.6 TFE 73% 1.4368 1.98 20.83 786,000 TFE (63) (69:19:12) PVP HFIB
27% 208,000 HFIB (21) 3.77 41 VAc (147) 70:20:10 Water.sup.d 1 L
186.3 (89) 70.7 TFE 66% 1.4439 2.01 17.69 857,000 TFE (42)
(71:16:13) PVP HFIB 34% 243,000 HFIB (21) 3.52 42 VAc (126)
60:30:10 t-BuOH 1 L 141.1 (67) 61.5 TFE 74% 1.4284 0.78 26.22
235,000 TFE (63) (62:24:14) MeAc HFIB 26% 100,000 HFIB (21) 2.33 43
VAc (126) 60:20:20 t-BuOH 1 L 148.4 (71) 57.2 TFE 48% 1.4198 0.59
29.83 204,000 TFE (42) (57:15:27) MeAc HFIB 52% 116,000 HFIB (42)
1.76 44 VAc (147) 70:20:10 t-BuOH 1 L 142.5 (68) 66 TFE 68% 1.4353
0.78 22.33 230,000 TFE (42) (66:19:15) MeAc HFIB 32% 126,000 HFIB
(21) 1.82 45 VAc (147) 70:20:10 Water 1 L 187.1 (89) 68.8 TFE 68%
1.4422 1.09 17.83 437,000 TFE (42) (69:17:14) PVP HFIB 32% 145,000
HFIB (21) 3.0 .sup.aVinyl acetate content determined by hydrolysis
of the acetate groups using standard base, fluoromonomer
incorporation was determined by .sup.19F NMR. .sup.bPolyvinyl
pyrrolidone (0.3 g) used as dispersing agent and isopropanol (5 mL)
used as chain transfer agent in aqueous polymerizations.
.sup.cElemental analysis .sup.dNo chain transfer agent used.
Examples 46-48
Two Coats on PMMA
Use of Poly(VAc/TFE/HFIB) as Primer Coat
Preferred VAc Content
[0102] Poly(VAc/TFE/HFIB) samples of different VAc content, see
Table 15 below, were used for the primer coat. Solutions, 2 wt %
poly(VAc/TFE/HFIB) in acetone, were made by agitating chunks of the
polymer with solvent for several days at room temperature. PMMA
plates measuring 2.5 cm by 5.0 cm by 3 mm thick were used for
testing. The PMMA plates were coated by lowering the plates into
the polymer solution at a rate of 300 mm/min. and then,
immediately, raising the plates back out of the solution at 50
mm/min. After 5-10 minutes air drying, the plates were dried
horizontally for 60 minutes in a 100.degree. C. air oven.
[0103] The topcoat, in every instance the same 57 mole % TFE/43
mole % HFP polymer, was prepared by the same method.
[0104] Table 15 below lists Examples and in order of increasing VAc
content.
TABLE-US-00015 TABLE 15 Two Coats, VAc/TFE/HFIB Primer, on PMMA
Primer Coat Mole % Adhesion Transmittance VAc/TFE/HFIB (/100) (%)
Comp. #1 Uncoated PMMA control -- 92.1 Example #46 36/12/52 100
96.8 Example #47 58/16/26 100 97.6 Example #48 69/17/14 100
97.3
[0105] For VAc contents from about 36 to 69 mole %, use of
poly(VAc/TFE/HFIB) as the primer coat gives excellent transmittance
(>96.8%) relative to uncoated PMMA (92.1%) along with excellent
adhesion (100/100).
Examples 49-55
Comparative Examples 20-23
[0106] Solutions of 2.5 wt % poly(VF2/TFE/HFP) in Novec.RTM.
HFE-7100 (3M Electronic Materials, St. Paul, Minn.) and
poly(TFE/HFP) in Fluorinert.RTM. (3M Electronic Materials, St.
Paul, Minn.) FC-75, were made by agitating chunks of the polymer
with solvent for several days at room temperature. PMMA and PC
plates measuring 2.5 cm by 5.0 cm by 3 mm thick, PET films
measuring 2.5 cm by 5.0 cm by 120 micron meter thick and glass
plates 2.5 cm by 5.0 cm by 1 mm thick were used for testing. The
plates were coated by lowering the plates into the polymer solution
at a rate of 300 mm/min. and then, 30 seconds later, raising the
plates back out of the solution at 125 mm/min. After 5-10 minutes
air drying, the plates were dried for 10 minutes in an air oven.
The temperature was 100.degree. C. for PMMA, 120.degree. C. for PC
and 300.degree. C. for glass plates. The PET films were dried for
60 minutes in a 100.degree. C. air oven. Transmittance, adhesion
and coating thickness were measured with the results shown in Table
16.
TABLE-US-00016 TABLE 16 Example #49 Example #50 Example #51 Example
#52 Example #53 Example #54 VF2 (mol %) 48 50 52 57 50 50 HFP (mol
%) 45 23 22 34 23 23 TFE (mol %) 7 27 26 9 27 27 Substrate PMMA
PMMA PMMA PMMA PC PET Thickness 90 90 90 90 90 90 (nm) Adhesion 100
100 100 100 100 100 (/100) Transmittance 97 98 97 97 95 97 (%)
Example #55 Comp. #20 Comp. #21 Comp. #22 Comp. #23 Comp. #24 VF2
(mol %) 50 -- -- -- -- 0 HFP (mol %) 23 -- -- -- -- 43 TFE (mol %)
27 -- -- -- -- 57 Substrate Glass PMMA PC PET Glass PMMA Thickness
90 Uncoated Uncoated Uncoated Uncoated 90 (nm) Adhesion 100 -- --
-- -- 0 (/100) Transmittance 96 92 87 90 90 97 (%)
[0107] Simultaneous good adhesion (>96/100) and improved
transmittance (>95%) relative to uncoated substrates were
observed for VF2/TFE/HFP polymers with 40 to 60 mole % VF2.
Examples 56-57
[0108] Solutions, 2.5 wt % poly(VF2/HFP=43/57 mole %) in
Vertrel.RTM. XF (E. I. DuPont de Nemours, Wilmington, Del.) and
poly(VF2/HFP=78/22 mole %) in MIBK, were made by agitating chunks
of the polymer with solvent for several days at room temperature.
PMMA plates measuring 2.5 cm by 5.0 cm by 3 mm thick and glass
plates 2.5 cm by 5.0 cm by 1 mm thick were used for testing.
Polymer films were prepared as in Examples 49 to 55 with a
thickness of 90 nm Lifting up speed was 200 mm/min. Transmittance
and adhesion were measured with the results shown in Table 17.
TABLE-US-00017 TABLE 17 Example #56 Example #57 VF2 (mol %) 43 78
HFP (mol %) 57 22 Substrate PMMA Glass Adhesion(/100) 100 100
Transmittance(%) 95 95
[0109] Simultaneous good adhesion (>96/100) and improved
transmittance (>95%) relative to uncoated PMMA and glass were
observed for VF2/HFP polymers with 40 to 80 mole % VF2.
Example 58
[0110] Solutions, 3 wt % poly(VF2/TFE/PMVE=32/15/53 mole %) in
Novec.RTM. HFE-7200 (3M Electronic Materials, St. Paul, Minn.) were
made by agitating chunks of the polymer with solvent for several
days at room temperature. PMMA plates measuring 2.5 cm by 5.0 cm by
3 mm thick were used for testing. Polymer films were prepared as in
Examples 1 to 7. Lifting up speed was 75 mm/min. Transmittance and
adhesion were measured with the results shown in Table 18.
TABLE-US-00018 TABLE 18 Example #58 VF2 (mol %) 32 TFE (mol %) 15
PMVE (mol %) 53 Substrate PMMA Adhesion (/100) 100 Transmittance
(%) 98
[0111] Simultaneous good adhesion (>96/100) and improved
transmittance (>95%) relative to uncoated PMMA were
observed.
* * * * *