Hardenable, fluorinated copolymer, process for its manufacture and its application in varnishes and paints

A hardenable, fluorinated copolymer of fluorinated monomers and a hydroxylated and/or epoxidized allyl ether, paints and varnishes comprising such copolymers, and the process of making such copolymer.

BACKGROUND OF THE INVENTION 
The present invention pertains to a hardenable, fluorinated copolymer of 
vinylidene fluoride (C.sub.2 H.sub.2 F.sub.2), at least one fluorinated 
monomer selected from tetrafluoroethylene (C.sub.2 F.sub.4), 
chlorotrifluroethylene (C.sub.2 F.sub.3 Cl) and hexafluoropropylene 
(C.sub.3 F.sub.6), and a hydroxylated and/or epoxidized allyl ether. This 
copolymer, which is soluble in organic solvents, is particularly 
recommended for the manufacture of paints and varnishes. 
Fluorinated polymers are known for their good mechanical properties and 
their excellent resistance to chemical products and weather. Nevertheless, 
their insolubility in conventional solvents makes then unusable for 
certain application such as, for example, that as a resin for paints and 
varnishes where their properties are sought for the manufacture of 
coatings with good chemical and weather resistance and easy maintenance. 
In order to profit from the desirable properties of the fluorinated 
polymers while avoiding their drawbacks, means were sought to make them 
soluble in conventional organic solvents. In order to achieve this, it is 
known to decrease the crystallinity of fluoride-containing polymers by 
copolymerization of monomers unsaturated in the ethylene position, of 
which monomers at least one is fluorinated. 
In addition, to use such copolymers it is desirable for certain 
applications, particularly for their application in the manufacture of 
paints and varnishes, to preserve for them a sufficient degree of rigidity 
and to make them hardenable by incorporation of functional groups into 
their structure. 
Such hardenable, fluorinated copolymers are described in French Patents 
2,597,873 and 2,569,703. These products are obtained by copolymerization 
of chlorotrifluoroethylene, a fatty ester, and hydroxylated or ethoxylated 
allyl glycidyl ether. These copolymers can possibly contain less than 20% 
of another, non-fluoride-containing comonomer. If these copolymers contain 
more than 20% of the preceding comonomer, they lose their solubility in 
solvents and their transparency. In addition, the introduction of fluorine 
by the intermediate of C.sub.2 F.sub.3 Cl alone also brings with it the 
chlorine-containing element which is not desirable in large amounts for 
the optical properties and resistance to corrosion. 
In JP 59-174,657/84, there is also described a hardenable copolymer based 
on vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, a 
vinyl ester and a hydroxylation agent. This copolymer, which contains less 
than 45% of vinyl ether fluoride and is based on vinyl ester, has the 
drawback of yielding after hydrolysis a rather strongly colored copolymer 
solution, which damages the transparency of the subsequently prepared 
varnishes. 
SUMMARY OF THE INVENTION 
The object of the present invention is a fluorinated copolymer, which is 
easily hardenable in the hot state in the possible presence of a hardening 
agent. When dissolved in an appropriate solvent, this copolymer may be 
used as a paint or varnish to form coatings which are hard, stable and 
transparent in the absence of pigments and which adhere well to metals, 
glass, wood, cement, plastics, and the like. 
The hardenable copolymer in accordance with the invention, which contains 
the copolymerization radicals of a fluorinated monomer and a hydroxylated 
and/or epoxidized allyl ether, is characterized in that: 
(i) the fluorinated monomer radicals originate from the association of 
vinylidene fluoride and another fluorinated monomer selected from among 
tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene and the 
mixture of at least two of these three monomers, and (ii) in that the 
allyl ether is selected from a compound of the formula: 
##STR1## 
R being: CH.sub.2 OH or 
##STR2## 
R.sub.1 being: H or CH.sub.3, R.sub.2 being: 
##STR3## 
in which P is a number from 0 to 3 
X is (CH.sub.2).sub.q --O in which q is a number from 1 to 3, and 
R.sub.5 and R.sub.6, which may be identical or different, are each H, 
CH.sub.2 OH, Ch.sub.2 --OH, or CH.sub.3 
R.sub.3 and R.sub.4, which may be identical or different, are each H or OH, 
and "n" and "m", which may be identical or different, being each numbers 
from 0 to 2. 
DETAILED DESCRIPTION 
With respect to copolymer, the association for 100 moles of the totality 
of fluorinated monomers is usually formed of: 
(i) 50 to 98 moles of vinylidene fluoride, and 
(ii) 2 to 50 moles of the other fluorinated monomer as defined. 
Preferably, the hardenable, fluorinated copolymer in accordance with the 
invention is characterized in that it is comprised of monomer radicals 
originating from: 
(i) 50 to 98 moles, preferably 70 to 85 moles, of vinylidene fluoride, 
(ii) 2 to 50 moles, preferably 15 to 20 moles, of fluorinated monomer 
selected from tetrafluoroethylene, chlorotrifluoroethylene, 
hexafluoropropylene, or a mixture of at least two of the three monomers, 
and 
(iii) 2 to 20 moles, preferably 5 to 10 moles, of the noted allyl ether per 
100 moles of the totality of fluorinated monomers. 
Compounds of the following formulas can be cited among the preferred allyl 
ethers: 
##STR4## 
In order to be able to use these copolymers in a liquid coating composition 
such as paint or varnish, it is recommended that the inherent viscosity of 
the copolymer dissolved in dimethyl formamide at 25.degree. C. at a 
concentration of 1 g/dL be within the range of 0.03 to 0.4 dL/g. 
The copolymer in accordance with the invention is principally obtained 
according to known solution polymerization procedures. A procedure 
consists of copolymerizing the monomers in a medium which is a solvent for 
all of the monomers, in the presence of an organosoluble initiator, at a 
temperature between 30 and 120.degree. C., preferably between 40 and 
80.degree. C., under a pressure of approximately 10 to 80 bars, preferably 
between 15 and 40 bars. 
In accordance with the invention, the hardenable copolymer is obtained by 
copolymerization of vinylidene fluoride, at least one fluorinated monomer 
selected from tetrafluoroethylene, chlorotrifluoroethylene or 
hexafluoropropylene, and the previously defined allyl ether. The following 
are employed for 100 moles of polymerized, fluorinated monomers; 
(i) 50 to 98 moles of vinylidene fluoride, and 
(ii) 2 to 50 moles of tetrafluoroethylene or chlorotrifluoroethylene or 
hexafluoropropylene or a mixture of at least two of the three monomers, 
with which is associated the previously defined allyl ether. 
In order to obtain a hardenable copolymer with the best properties, one 
usually associates 2 to 20 moles of the previously defined allyl ether per 
100 moles of the totality of the fluorinated monomers. 
In accordance with a preferred copolymerization mode, the solvent is heated 
to the selected reaction temperature in an agitated reactor which has 
first been degassed. A mixture of fluorinated monomers as well as an 
initial fraction of allyl ether are introduced into the reactor. 
The amount of monomer mixture to be introduced to reach the selected 
reaction pressure depends on the solubility conditions of the fluorinated 
monomers in the selected solvent. The monomer to solvent weight ratio is 
generally between 0.1 and 1. 
When the reaction pressure and the reaction temperature are reached, the 
polymerization initiator is introduced into the reaction. The formation of 
polymer is manifested by a drop in pressure which is compensated by for 
adding a fluorinated monomer mixture. 
One can add a fluorinated monomer mixture of molar composition identical to 
that which was introduced initially. It is also possible to take into 
account the individual reactivities of each comonomer and adjust the 
composition of the mixture added during polymerization in order to create 
a copolymer of homogeneous composition. 
The allyl compound can also be added during polymerization. 
The allyl derivative is added in such a manner that the composition of the 
mixture of fluorinated monomers and allyl derivative introduced remains 
constant during the duration of the polymerization. 
The addition of monomer mixture for maintaining the pressure is continued 
for a sufficiently long period of time to reach a dry extract on the order 
of 10 to 60%, preferably 15 to 40%. 
The volatile residual monomers can be eliminated by degassing. 
The final solution is extracted from the reactor and can be stored in that 
form. It can also be concentrated immediately or subsequently in order to 
obtain the amount of dry extract selected for the use of the copolymer. 
The solvents selected for the copolymerization reaction must allow 
solubilization of the monomer mixture while remaining inert in relation to 
the other reaction components. They are selected preferably from among the 
acetates and alcohols. Among the preferred acetates, butyl, isobutyl and 
ethyl acetate are particularly recommended. When the copolymer is prepared 
for the purpose of application in formulations for paint or varnish, the 
butyl acetate or isobutyl acetate employed as solvent during the 
copolymerization can make it possible to obtain directly, without 
subsequent treatment, a composition which is usable as it is after, of 
course, addition of the complementary additives which are standard for 
these types of varnish and paint formulations. 
The copolymerization initiators are known per se, the most popular being 
selected from among the radical polymerization initiators such as the 
perdicarbonates, perpivalates and azo compounds, such as diisopropyl or 
dicylcohexyl percarbonate, tertiobutyl or tertioamyl perpivalate, 
azobisisobutyronitrile and azo-bis-2,2-dimethylvaleronitrile. 
Taking into account the effect of the solvent transfer agent and the cited 
initiators, the molecular weights of the polymers obtained are relatively 
low. 
When the cross-linkable copolymer in accordance with the invention is to be 
used as the basis for a paint or varnish formulation, it can, as was 
already mentioned, be used as it is in its initial reaction solvent 
medium. It can also be more or less concentrated and put again into 
solution in a solvent which is better adapted to the type of paint or 
varnish desired. As is, the copolymer in solvent medium yields a colorless 
and transparent solution. To this solution can be added the desired 
additives such as pigments, fillers, diluents, ultraviolet absorption 
agent, catalysts, stabilizing agent or even hardening agent to improve the 
hardening reaction via hot cross-linking. Among the most well-known 
hardening agents can be cited melamine formaldehyde, the isocyanates, 
polyamides, organic acids or their anhydrides. The cross-linking 
temperature of these copolymers is generally between 0.degree. to 
260.degree. C. and essentially depends on the chemical nature of the 
hardener and the conditions of implementation. 
The invention will be further described in connection with the following 
examples which are set forth for purposes of illustration only.

EXAMPLE 1 
Two liters of ethyl acetate are introduced into a 3.3-L autoclave equipped 
with effective agitation, which has been degassed under vacuum. The 
autoclave is brought to a temperature of 70.degree. C. At this 
temperature, one adds 609 g of fluorinated monomer mixture containing 
vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene to 
reach 20 bars of pressure in the respective molar proportions of 79/15/6. 
One then adds 20.6 g of 3-allyloxy 1-2 propane diol, and then 11 g of 
tertiobutyl perpivalate. 
To maintain the pressure at 20 bars, one adds over four hours 435 g of 
fluorinated monomer mixture containing vinylidene fluoride, 
tetrafluoroethylene and chlorotrifluoroethylene in the respective molar 
proportions of 79/15/6. 
One adds simultaneously and continuously over the same duration of 
polymerization 41.6 g of 3-allyloxy 1-2 propane diol. 
After four hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
26.5%. The copolymer contains fluorinated structural units originating 
from the vinylidene fluoride, tetrafluoroethylene and 
chlorotrifluoroethylene in the respective molar proportions of 81/13/7, 
determined by NMR (nuclear magnetic resonance) of the fluorine 19. The 
molar level of 3-allyloxy 1-2 propane diol in the copolymer is 4.3 mol. % 
in relation to the totality of fluorinated structural units. The inherent 
viscosity of the copolymer is 0.122 dL/g. 
EXAMPLE 2 
Two liters of butyl acetate are introduced into a 3.3-L autoclave equipped 
with effective agitation, which has been degassed under vacuum. The 
autoclave is brought to a temperature of 70.degree. C. At this 
temperature, one adds 491 g of fluorinated monomer mixture containing 
vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene to 
reach 20 bars of pressure in the respective molar proportions of 79/15/6. 
One then adds 40.8 g of 3-allyloxy 1-2 propane diol, and then 20 g of 
tertiobutyl perpivalate. 
To maintain the pressure at 20 bars, one adds over six hours 360 g of 
fluorinated monomer mixture containing vinylidene fluoride, 
tetrafluoroethylene and chlorotrifluoroethylene in the respective molar 
proportions of 79/15/6. 
One adds simultaneously and continuously over the same duration of 
polymerization 41.6 g of 3-allyloxy 1-2 propane diol. 
After six hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
19%. The copolymer contains fluorinated structural units originating from 
the vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene 
in the respective molar proportions of 82/12/7, determined by NMR of the 
fluorine 19. The molar level of 3-allyloxy 1-2 propane diol in the 
copolymer is 8.6 mol. % in relation to the totality of fluorinated 
structural units. The inherent viscosity of the copolymer is 0.067 dL/g. 
EXAMPLE 3 
Two liters of ethyl acetate are introduced into a 3.3-L autoclave equipped 
with effective agitation, which has been degassed under vacuum. The 
autoclave is brought to a temperature of 50.degree. C. At this 
temperature, one adds 890 g of fluorinated monomer mixture containing 
vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene to 
reach 20 bars of pressure in the respective molar proportions of 79/15/6. 
One then adds 40.8 g of 3-allyloxy 1-2 propane diol and then 10 g of 
cyclohexyl perdicarbonate. 
To maintain the pressure at 20 bars, one adds over five hours 230 g of 
fluorinated monomer mixture containing vinylidene fluoride, 
tetrafluoroethylene and chlorotrifluoroethylene in the respective molar 
proportions of 79/15/6. 
One adds simultaneously and continuously over the same duration of 
polymerization 21 g of 3-allyloxy 1-2 propane diol. 
After five hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
20.8%. The copolymer contains fluorinated structural units originating 
from the vinylidene fluoride, tetrafluoroethylene and 
chlorotrifluoroethylene in the respective molar proportions of 
82/12.5/6.5, determined by NMR of the fluorine 19. The molar level of 
3-allyloxy 1-2 propane diol in the copolymer is 4.5 mol. % in relation to 
the totality of fluorinated structural units. The inherent viscosity of 
copolymer is 0.207 dL/g. 
EXAMPLE 4 
Two liters of ethyl acetate are introduced into a 3.3-L autoclave equipped 
with effective agitation, which has been degassed under vacuum. The 
autoclave is brought to a temperature of 50.degree. C. At this 
temperature, one adds 1,173 g of fluorinated monomer mixture containing 
vinylidene fluoride and chlorotrifluoroethylene to reach 20 bars of 
pressure in the respective molar proportions of 85/15. 
One then adds 35.6 g of 3-allyloxy 1-2 propane diol, and then 15 g of 
cyclohexyl perdicarbonate. 
To maintain the pressure of 20 bars, one adds over six hours 121g of 
fluorinated monomer mixture containing vinylidene fluoride and 
chlorotrifluoroethylene in the respective molar proportions of 85/15. 
One adds simultaneously and continuously over the same duration of 
polymerization 15.6 g of 3-allyloxy 1-2 propane diol. 
After six hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
14%. The copolymer contains fluorinated structural units originating from 
the vinylidene fluoride and chlorotrifluoroethylene in the respective 
molar proportions of 70/30, determined by NMR of the fluorine 19. The 
molar level of 3-allyloxy 1-2 propane diol in the copolymer is 5.5 mol. % 
in relation to the totality of fluorinated structural units. The inherent 
viscosity of the copoymer is 0.161 dL/g. 
EXAMPLE 5 
Two liters of ethyl acetate are introduced into a 3.3-L autoclave equipped 
with effective agitation, which has been degassed under vacuum. The 
autoclave is brought to a temperature of 70.degree. C. At this 
temperature, one adds 600 g of fluorinated monomer mixture containing 
vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene to reach 
20 bars of pressure in the respective molar proportions of 75/15/10. 
One then adds 30.6 g of 3-allyloxy 1-2 propane diol, and then 11 g of 
tertiobutyl perpivalate. 
To maintain the pressure of 20 bars, one adds over six hours 405 g of 
fluorinated monomer mixture containing vinylidene fluoride, 
tetrafluoroethylene and hexafluoropropylene in the respective molar 
proportions of 75/15/10. 
One adds simultaneously and continuously over the same duration of 
polymerization 41.2 g of 3-allyloxy 1-2 propane diol. 
After six hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
25%. The copolymer contains fluorinated structural units originating from 
the vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene in 
the respective molar proportions of 78/16/6, determined by NMR of the 
fluorine 19. The molar level of 3-allyloxy 1-2 propane diol in the 
copolymer is 4.3 mol. % in relation to the totality of fluorinated 
structural units. The inherent viscosity of the copolymer is 0.181 dL/g. 
EXAMPLE 6 
Into a 3.3-L autoclave equipped with effective agitation, which has been 
degassed under vacuum, one introduces 2 liters of ethyl acetate. The 
autoclave is brought to a temperature of 70.degree. C. At this 
temperature, one adds 610 g of fluorinated monomer mixture containing 
vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene to 
reach 20 bars of pressure in the respective molar proportions of 79/15/6. 
One then adds 22 g of 3-allyloxyethanol and then 15 g of tertiobutyl 
perpivalate. 
To maintain the pressure of 20 bars, one adds over six hours 430 g of 
fluorinated monomer mixture containing vinylidene fluoride, 
tetrafluoroethylene and chlorotrifluoroethylene in the respective molar 
proportions of 79/15/6. 
One adds simultaneously and continuously over the same duration of 
polymerization 48 g of 3-allyloxyethanol. 
After six hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
26%. The copolymer contains fluorinated structural units originating from 
the vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene 
in the respective molar proportions of 81/12/7, determined by NMR of the 
fluorine 19. The molar level of 3-allyloxyethanol in the copolymer is 6.1 
mol. % in relation to the totality of fluorinated structural units. The 
inherent viscosity of the copolymer is 0.117 dL/g. 
EXAMPLE 7 
Into a 3.3-L autoclave equipped with effective agitation, which has been 
degassed under vacuum, one introduces 2 liters of ethyl acetate. The 
autoclave is brought to a temperature of 70.degree. C. At this 
temperature, one adds 609 g of fluorinated monomer mixture containing 
vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene to 
reach 20 bars of pressure in the respective molar proportions of 79/15/6. 
One then adds 19.1 g of allylglycidyl ether and then 15 g of tertiobutyl 
perpivalate. 
To maintain the pressure at 20 bars, one adds over six hours 440 g of 
fluorinated monomer mixture containing vinylidene fluoride, 
tetrafluoroethylene and chlorotrifluoroethylene in the respective molar 
proportions of 79/15/6. 
One adds simultaneously and continuously over the same duration of 
polymerization 39.4 g of allylglycidyl ether. 
After six hours of polymerization, the autoclave is degassed and one 
discharges a transparent copolymer solution which has a dry extract of 
25%. The copolymer contains fluorinated structural units originating from 
the vinylidene fluoride, tetrafluoroethylene and chlorotrifluoroethylene 
in the respective molar proportions of 81/13/6, determined by NMR of the 
fluorine 19. The molar level of allylglycidyl ether in the copolymer is 
4.3 mol. % in relation to the totality of fluorinated structural units. 
The inherent viscosity of the copolymer is 0.122 dL/g. 
EXAMPLE 8 
The following varnish is prepared by simple mixing of the constituents: 
______________________________________ 
Parts by Weight 
______________________________________ 
(i) fluorinated copolymer of 
100 
Example 1 containing 4.3M 
of allyloxypropanediol and at 
26.5% of dry extract in ethyl acetate 
(ii) partially methylated melamine 
12.6 
formaldehyde resin (viscosity 
7,000 mPa.s at 90% dry extract 
in isobutanol) 
______________________________________ 
The varnish is applied in 100.mu.m strokes on a chromated aluminum support, 
then baked for 30 minutes at 130.degree. C. to yield an 18.mu.m thick, dry 
film. The cross-linkage is evaluated by the methyl ethyl ketone (MEK) 
resistance test in which a cotton cloth impregnated with methyl ethyl 
ketone is rubbed with a back and forth movement over the film until the 
film is abraded. A number of back and forth strokes between 50 and 100 is 
an indication of good cross-linkage. A number equal to 100 or more is the 
indication of excellent cross-linkage. The compatibility of the varnish is 
evaluated on the basis of transparency of the films obtained with: 
______________________________________ 
E = excellent total transparency 
G = good slight clouding 
P = poor translucent film 
______________________________________ 
The film produced above resisted more than 100 back and forth strokes with 
MEK and displayed an excellent transparency. 
EXAMPLE 9 
The following varnishes are prepared by simple mixing of the constituents 
(in parts by weight): 
______________________________________ 
2A 2B 2C 2D 
______________________________________ 
(i) fluorinated copolymer of 
100 100 100 100 
Example 2 (containing 
8.6 mol. % of 
alloxypropanediol 
and 19% of 
dry extract in 
butyl acetate) 
(ii) partially methylated 
7.0 7.0 -- -- 
melamine formaldehyde 
resin (viscosity 
7,000 mPa.s at 90% 
dry extract 
in isobutanol) 
(iii) 
hexamethylene -- -- 7.3 7.3 
diisocyanate 
trimer (NCO 
content 22%) 
(iv) dibutyltin dilaurate 
-- -- 0.05 0.05 
______________________________________ 
These varnishes are applied in 150.mu.m strokes on a 0.7-mm thick chromated 
aluminum support. 
Test 2A is baked at 130.degree. C. for 30 minutes. 
Test 2B is baked so as to obtain a minimum plate temperature (MPT) of 
250.degree. C. for 40 seconds. 
Test 2C is allowed to dry at room temperature for days. 
Test 2D is baked at 80.degree. C. for 30 minutes and then left at room 
temperature for 8 days. 
The films exhibit the following characteristics: 
______________________________________ 
2A 2B 2C 2D 
______________________________________ 
MEK performance 
&gt;100 &gt;100 &gt;100 &gt;100 
Compatibility 
E E E E 
______________________________________ 
EXAMPLE 10 
The copolymer of Example 2 is concentrated until a dry extract of 50% is 
obtained. 
A paint is prepared under the following conditions: 
One mixes 60.5 g of copolymer solution with 28.3 g of titanium dioxide in a 
ball mill so as to obtain a grinding paste with a grinding fineness 
smaller than 10 .mu.m. 
One takes 178 g of this paste and deconcentrates it with 22.4 g of 
partially methylated melamine formaldehyde resin to yieId a white paint 
which has a Ford cup number 4 viscosity of 80 seconds. 
This white paint is applied on chromated aluminum with 100.mu.m spiral 
strokes and then baked for 30 minutes at 130.degree. C. in order to obtain 
a 22.mu.m thick, dry film. The paint obtained resists more than 100 back 
and forth strokes with MEK, has a Gardner luster measured at 60.degree. of 
50%, a class 0 adherence determined according to NFT standard 30 038 and 
is not affected by a 1,000 hour exposure to the Q.U.V. The Q.U.V is an 
accelerated aging device in which the effects of sunlight are reproduced 
by means of four tubes emitting ultraviolet rays. The temperature during 
the ultraviolet exposure is 63.degree. C. A water-condensation device 
makes it possible to maintain the humidity level at 100% relative humidity 
during the condensation phase. The temperature of the sample during the 
condensation phase is 50.degree. C. The condensation and irradiation 
phases, each lasting four hours, are alternated. 
EXAMPLE 11 
A varnish is prepared by simply mixing of the consituents (in parts by 
weight): 
______________________________________ 
(i) fluorinated copolymer of 
100 
Example 3 (4.5 mol. % of 
allyloxy propane diol at 
20.8% in ethyl acetate) 
(ii) partially methylated melamine 
5.7 
formaldehyde resin (viscosity 
7,500 mPa.s at 90% in isobutanol) 
______________________________________ 
This varnish is applied in 150.mu.m strokes on a 0.8-mm galvanized steel 
support, then baked at 130.degree. C. for 30 minutes to yield an 18.mu.m 
thick, dry film. 
This film resists more than 100 back and forth strokes with MEK and 
exhibits excellent transparency. 
EXAMPLE 12 
The copolymer solution of Example 3 is concentrated to a dry extract of 
64%. One mixes 516 g of solution with 186 g of a blue cobalt pigment and 
41 g of ethyl 3-ethoxypropionate in a ball mill so as to obtain a grinding 
paste with a grinding fineness smaller than 10 .mu.m. 
One takes 148.6 g of the resultant pigment paste and deconcentrates it with 
18.4 g of partially methylated melamine formaldehyde resin and one adjusts 
the Ford cup number 4 viscosity to 80 seconds by diluting with 33 g of 
ethyl 3-ethoxypropionate. 
This blue paint is applied on a 0.8-mm thick galvanized steel plate with 
100.mu.m strokes and then baked at 130.degree. C. for 30 seconds to yield 
a 22.mu.m thick film. This paint resists more than 100 back and forth 
strokes with MEK, has a Gardner luster measured at 60.degree. of 40%, a 
class 0 adherence determined according to NFT standard 30 038 and is not 
affected by a 1,000 hour exposure to the Q.U.V. 
EXAMPLE 13 
A varnish is prepared by simple mixing of the following constituents (in 
parts by weight): 
______________________________________ 
4A 4B 
______________________________________ 
(i) fluorinated copolymer of Example 
100 100 
4 (5.5 mol. % in allyloxy propane 
diol and 14% of dry extract in 
ethyl acetate) 
(ii) partially methylated melamine 
3.9 -- 
formaldehyde resin 
(iii) 
hexamethylene diisocyanate trimer 
-- 3.4 
(iv) dibutyltin dilaurate -- 0.05 
______________________________________ 
These varnishes are applied in 150 .mu.m strokes on a 0.7 mm thick 
chromated aluminum plate. 
Test 4A is baked at 130.degree. C. for 30 minutes to yield a 16 .mu.m 
thick, dry film. 
Test 4B is baked at 80.degree. C. for thirty minutes then left for 30 days 
at room temperature to yield a 16.mu.m thick film. 
The films exhibit the following characteristics: 
______________________________________ 
4A 4B 
______________________________________ 
MEK performance &gt;100 95 
Compatibility E E 
______________________________________ 
EXAMPLE 14 
The preceding copolymer is concentrated to a 68.5% dry extract solution in 
ethyl acetate. 
One mixes 424 g of copolymer solution with 272 g of titanium dioxide and 
158 g of ethyl 3-ethoxypropionate in a ball mill so as to obtain a 
grinding paste with a grinding fineness smaller than 10,.mu.m. 
One takes 170.8 g of this paste and deconcentrates it with 21.6 g of 
melamine formaldehyde resin and 7.8 g of ethyl 3-ethoxypropionate to yield 
a white paint which has a Ford cup number 4 viscosity of 85 seconds. 
This white paint is applied on a 0.7 mm thick chromated aluminum plate with 
100.mu.m spiral strokes and then baked for 30 minutes at 130.degree. C. 
The paint obtained resists more than 100 back and forth strokes with MEK, 
has a Gardner luster measured at 60.degree. C. of 55%, a class 0 adherence 
determined according to NFT standard 30 038 and is not affected by a 1,000 
hour exposure to the Q.U.V. 
EXAMPLE 15 
A varnish is prepared by simple mixing of the following constituents (in 
parts by weight): 
______________________________________ 
(i) fluorinated copolymer of Example 
100 
5 (4.3 mol. % of allyloxy propane 
diol and 25% of dry extract in 
ethyl acetate) 
(ii) hexamethoxymethylmelamine resin 
2.7 
(HMMM) 
______________________________________ 
This varnish is applied in 125.mu.m strokes on a 0.8 mm thick galvanized 
steel support. The plate is baked so as to obtain a minimum plate 
temperature (MPT) of 250.degree. C. for 40 seconds and a 20.mu.m thick, 
dry film which resists more than 100 back and forth strokes with MEK and 
has good compatibility with 
EXAMPLE 16 
A varnish is prepared by simple mixing of the following constituents (in 
parts by weight): 
______________________________________ 
6A 6B 
______________________________________ 
(i) fluorinated copolymer of 
100 100 
Example 6 (6.1 mol. % of 
allyloxy ethanol and 26% of 
dry extract in ethyl acetate) 
(ii) partially methylated melamine 
9.6 -- 
formaldehyde resin 
(iii) 
p-toluene sulfonic acid 
0.2 -- 
(iv) hexamethylene diisocyanate trimer 
-- 3.9 
(v) dibutyltin dilaurate -- 0.05 
______________________________________ 
These varnishes are applied in 150.mu.m strokes on a 0.7 mm thick chromated 
aluminum support. 
Test 6A is baked at 150.degree. C. for 30 minutes to yield a 24 .mu.m thick 
film. 
Test 6B is baked at 80.degree. C. for thirty minutes then left for 30 days 
at room temperature to yield a 22.mu.m thick, dry film. 
The films exhibit the following characteristics: 
______________________________________ 
6A 6B 
______________________________________ 
MEK performance &gt;100 &gt;100 
Compatibility E E 
______________________________________ 
EXAMPLE 17 
The preceding copolymer is concentrated to 55% dry extract solution in 
ethyl acetate. One mixes 200 g of this copolymer solution with 102.8 g of 
a white titanium dioxide pigment and 38.6 g of ethyl 3-ethoxypropionate in 
a ball mill so as to obtain a grinding paste with a grinding fineness 
smaller than 10.mu.m. 
One takes 170.7 g of the resultant pigment base and deconcentrates it with 
20.4 g of partially methylated melamine formaldehyde resin and 0.4 g of 
p-toluene sulfonic acid and one adjusts it to a Ford cup number 4 
viscosity of 80 seconds by diluting with 40 g of ethyl 3-ethoxypropionate. 
The white paint is applied on a 0.7 mm thick chromated aluminum plate with 
10.mu.m strokes and then 7 baked for 30 minutes at 150.degree. C. to yield 
a 24.mu.m thick, dry film. The white paint obtained resists more than 100 
back and forth strokes with MEK, has a Gardner luster measured at 
60.degree. of 45%, a class 0 adherence determined according to NFT 
standard 30 038 and is not affected by a 1,000 hour exposure to the Q.U.V. 
EXAMPLE 18 
A varnish is prepared by simple mixing of the following constituents (in 
parts by weight): 
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(i) fluorinated copolymer of Example 7 
200 
(4.3 mol. % of allylglycidyl ether 
and 25% of dry extract in ethyl 
acetate) 
(ii) 4,4' diaminodiphenyl methane 
1.4 
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The varnish is applied with a pneumatic gun onto a polypropylene plate that 
had first been given a chlorinated paraffin-based primer coat. 
The plate was baked at 60.degree. C. for 45 minutes to obtain 16.mu.m 
thick, dry film and then left at room temperature for eight days. 
The film exhibits a class 0 adherence on the support as determined by NFT 
standard 30 038 and resists more than 100 back and forth strokes with MEK. 
While the invention has been described in connection with a preferred 
embodiment, it is not intended to limit the scope of the invention to the 
particular form set forth, but on the contrary, it is intended to cover 
such alternatives, modifications, and equivalents as may be included 
within the spirit and scope of the invention as defined by the appended 
claims.