Note: Descriptions are shown in the official language in which they were submitted.
,t ,..
4~
BACKGROUND O~ THE INVENTION
This lnvention is related to coatlng compositions
and in particular to acrylic lacquer coating compositions.
To refinish or repair acrylic lacquer and acrylic
enamel Pinishes of automobile and truck bodies, different
coating compositions have been utilized for the enamel and for
the lacquer finishes. Willey U.S. 3,711,433 issued January 16,
1973 illustrates a typical composition utilized to re-
finish or repair acrylic lacquer finishes and Walus et al.,
U.S. 3,488,307 issued January 6, 1970 illustrates a
typical composition utilized to refinish or repair acrylic
enamel finishes. These aforementioned compositions are
excellent refinish compositiOns. However, to reduce costs
and.simplify inventories for both suppliers and users which
typically are auto body repair shops, a single composition
is desired that could be used to refinish or repai~ both
eriamel and lacquer finishes.
The novel canposition of this invention can be used to
refinish or repair enamel and lacquer finishes of autc~nobile and truck
bodies and has excellent adhesion to these finishes, good appearance,
good durability and weatherability. me ccmposition can also be used
as an o~iginal equipment finish that is applied by a manufacturer to
automobile and truck bodies.
SUMMARY OF THE INVENTION
The coating canposition comprises about 5-40~ by weight
of a film fo~ng binder and about 60-95% by weight of volatile organic
solvents; wherein the binder consists essentially of
(a) 15-25% by weight~ based on the weight of the
binder, of polymethyl methacrylate having a
relative viscosity of about 1.17-1.20 measured
~ i
at 25C on a 0.5% polymer 5O11~5 solutlon using
dichloroethylene as the solvent;
tb) 5-15% by weight, based on the weight
of the binder, of a copolymer of
methyl methacrylate and alkyl amino
alkyl methacrylate having 1-4 carbon
atoms ln the alkyl group and having a
relatlve viscosity of about 1.17-
1.20 measured as above;
; 10 tc) 20-40% by weight, based on the weight
of the binder, of a copolymer of
methyl methacrylate and an alkyl
acrylate having 2-8 carbon atoms
in the alkyl group and having a
relatlve viscosity of 1.17-1.20
measured as above;
(d) 5-25% by weight, based on the
. weight of the binder, of cellulose
acetate butyrate having a viscosity
of about 1-20 seconds and a butryl .
content of about 30-55~ by weight;
(e) 15-30% by weight, based on the weight
of the binder, of a polyester plasti-
cizer of a saturated fatty oil, a polyol and an
organic dicarboxylic acid or an
anhydrideof an organic dicarboxylic acid
having an acid number of about 0.1-10; and
(f) 1-10% by weight, based on the weight of the binder ,
of a polymer of methyl methacrylate,an alkyl acrylate
having 2-12 carbon atoms in the alkyl group and an
;~
~ L~.Z~;35
drB unsaturated monocarboxylic acid and in which
the polymer ls reacted wlth an
alkylene imine and havlng a relatlve
viscoslty of about 1.17-1.20 measured
as above;and
wherein the total of (a), (b), (c), (d)
(e) and (f) are 100%.
DESCRIPTION OF THE INVENTION
~he coatlng composltion has a binder content
Or film-forming constituents of about 5-40% by weight.
The remainder of the constituents in the composition is
a solvent blend for the binder. In addition, the compo-
sition optionally contains pigment in a pigment to binder
ratio of about 1.0/100 to 100/100.
The acrylic polymers utilized in the coating
composition are prepared by solution polymerization in
which the monomers are blended with a solvent, polymeri-
- zation catalyst and heated to about 75-150C for 2-6
hours to form a polymer that has a relative viscosity
of about 1.17-1.20 measured at 0.5% polymer solids at
25C uslng dlchloroethylene as the solvent.
Typical solvents which are used to prepare the
acrylic polymers are the following: toluene, ethyl
acetate, acetone, ethylene monoethylether acetate,methyl-
ethyl ketone, lsopropyl alcohol, and other allphatic, cyclo-
allphatlc and aromatic hydrocarbon, esters, ethers,
ketones and alcohols which are conventionally used.
About 0.1-4% by welght, based on the weight of
the monomers, of the polymerization catalyst is used to
435
prepare the acrylic polymer. Typlcal catalysts are:
az~-bis-isobutyronltrile, azo-bis(-~-gamma dlmethyl)
valeronitrile), benzoyl peroxide, t-butyl plvalate and
the like.
A chain transfer agent can be used to
control the molecular weight of the acryllc polymers.
Typical chain transfer agents are 2-mercapto ethanol,
dodecyl mercaptan, benzene thioethanol, mercapto
succinic acid, butyl mercaptan, mercapto proprionic
acid and the like.
The coating composition contains about 15-
25% by weight, based on the weight of the binder, of
polymethyl methacrylate havlng the aforementioned
relative viscosity. Preferably, about 17-20% by weight,
based on the weight of the binder, of polymethyl metha-
crylate is used in the coating composition.
The coating composition contains about 5-15%
by weight, based on the weight of the binder, of a
copolymer of methyl methacrylate and an alkyl amino
alkyl methacrylate having the aforementioned relative
viscosity. Typical alkyl amino alkyl methacrylates are
dimethylaminoethyl methacrylate,diethylaminoethyl
methacrylate, tertiary butyl aminoethyl methacrylate
and the like. Preferably, the copolymer contains about
90-99.5% by weight of methyl methacrylate~and 0.5-10%
by weight of the alkyl amino alkyl methacrylate such
as diethyl amino ethyl methacrylate. One preferred coating
composition contains about 8-12% by weight of the above copolymer.
~.244~5
The coating composition contains about 20-40%
by weight, based on the weight of the binder, of a copolymer
of methyl methacrylate and an alkyl acrylate having
2-8 carbon atoms in the alkyl group and having the afore-
mentioned relative viscosity. The polymer usually con-
tains 80-9Q% by weight methyl methacrylate and 10-20%
by weight butyl acrylate. Other alkyl acrylates that can
be used are ethyl acrylate, propyl acrylate, hexyl
acrylate, lsobutyl acrylate, 2 ethylhexyl acrylate and
the like. Preferably, the coating compositon contains
about 25-35% by weight of the above polymer.
The coating composition contains about 1-10%
by weight, based on the weight of the binder, of a poly-
mer of methyl methacrylate, an alkyl acrylate having
2-12 carbon atoms in the alkyl group and an ~,~ unsatu-
rated monocarboxylic acid in which the polymer is reacted
with an alkylene imine. Any of the aforementioned alkyl
acrylates can be used to prepare the polymer including
nonyl acrylate, decyl acrylate and lauryl acrylate.
Preferably, ethyl acrylate, butyl acrylate, butyl acrylate or 2 ethyl
acrylate is used. Typically useful acids used to prepare this polymer
are acrylic acid and methacrylic acid. Alkylene imines such as propylene
imine or ethylene imine or hydroxy ethyl ethylene imine are reacted with
the carboxyl groups of the acid of the polymer. Generally, about 90-
100% of the carboxyl groups are reacted with an alkylene imine. About
2-5% by weight, based on the weight of the binder, of one particularly
useful polymer can be used in the composition in which the polymer is
of 70-90% by weight of methyl methacrylate, 9-20% by weight of ethyl
acrylate and 1-10% by wei~ht of methacrylic acid which is reacted with
propylene imine.
-- 6 --
~ 2~4~i
About 5-25% by weight, based on the welght of
the blnder, of cellulose acetate butyrate (CAB~ ls used
ln the coatlng composition. The CAB has a butyryl content
of about 30-55% by weight and a viscosity of about
1-20 seconds measured according to ASTMD 1343-56 a
blend of a high viscosity CAB and a low viscosity CAB
can be used in the composition in a weight ratio of
about l:l.to 1:6. The high viscosity CAB has a butyryl
content of about 35-40% by weight and a viscosity of
15-20 seconds and the low viscosity CAB has the same
butyryl content and a viscosity of about ~-3 seconds.
In one preferred composition of 3-15% of the low
vlscosity CA~ is used in combination with about 3-10% by
weight of the high viscosity CAB.
The composition contains about 15-30% by weight,
based on the weight of the binder, of a polyester plasticizer
of a saturated fatty oil, a polyol and an organic
dicarboxylic acid or an anhydride thereof having an
acid number of about 0.1-10. The polyester is pre-
pared by conventional polymerization techniques in whichthe constituents and a conventional esterification
catalyst such as lead tallate, sodium naphthenate,
barium oxide, barium hydroxide, lithium hydroxide are
reacted at 80-200C for about 0.5-6 hours. A typical
saturated fatty oil that can be used to prepare the poly-
ester is coconut oil: Polyesters of a polyol and an organic dicarboxylic
acid or anhydride thereof without a saturated fatty oil can also be used.
Typical polyols that can be used to prepare
the polyester are ethylene glycol, propylene glycol, dipropylene
glycol, butane diol, diethylene glycol, neopentyl glycol and the like.
-- 7 --
Z L~4 3 S
Other polyols that can be used are glycerol, trimethylol
propane, trimethylol ethanej pentaery thritol,
dlpentaerytrhrito~ sorbitol and the like.
Typical organic dicarboxyllc acids or anhydrides
that can be used to prepare the polyester are adipic
acid, azelaic acid ? chlorendic acid, chlorendic anhydride,
phthalic acid, phthalic anhydride, terephthalic acid,
isophthalic acid, succinic acid, succinic anhydride
trimelletic acid, trimelletic anhydride and the like.
One particularly useful polyester.used in
the coating composition is of coconut oil, ethylene
glycol and phthalic anhydride. ~bout 20-25% by weight,
based on the weight of the binder, of the alkyd resin
is used in the composition.
Another aspect of this invention is a coating
composition comprising 5-40% by weight of a film-forming
binder and 95-60% by weight of a volatile organic solvent,
wherein the binder consists essentially of about
ta) 30-50% by weight, based on the weight
~ 20 ofthe binder, of polymethyl methacrylate having a
relative viscosity of about 1.17 to 1.20 measured
at 25C on a 0.5~ polymer solids
solution using a dichloroethylene
.. . . _ . _
: solvent; -_.
(b) 20-40% by weight, based on the weight
of the binder, of cellulose acetate
butyrate having a viscosity of about
1-3 seconds and a butyryl content
of 30-55% by weight;
4;35
-(c) 5-15% by weight, based on the weight
of the binder, of a phthalate ester
plasticlzer,
(d) 10-30% by weight, based on the weight
of the binder, of a~polyester plasticizer of
a saturated fatty oil, a polyol and an organic
dicarboxylic acid or an anhydride of
a dicarboxylic acid and having an acid
number of about 0.1-10; and
(e) 1-10% by weight, based on the weight of
the binder, of a polymer of methyl
methacrylate, an alkyl acrylate having
2-12 carbon atoms in the alkyl group and ~ ;
an ~,~-unsaturated monocarboxylic acid
and in which the polymer is reacted with
an alkylene lmine and having a relative
ViSGosity of about 1.17 to 1.20 measured as
above,
wherein the total of (a), (b), (c), (d) and (e) are 100%.
The aforementioned polymethyl methacrylate,
cellulose acetate butyrate and high and low viscosity
blends thereof or cellulose acetate butyrate having a 1-3
second viscosity and a butyryl content of 35-40% by weight,
the polyester and the acrylic resin reacted ~ith an alkylene
imine can be used the above coating composition. Preferred
phthalate ester plasticizers are butyl cyclohexyl phthalate.
and butyl benzyl phthalate.
As mentioned before, the composition can contain
pigments. These pigments can be introduced into the
compositlon by ~lrst ~orming a mill base wlth any of the
above polymers utillzed in the coating composltion or with
other compatible polymers by conventional techniques,
such as s&nd-grinding, ball milling, attritor grinding, or two
roll milling to disperse the pigments. The mill base
is blended with the film-~orming constituents as shown
in the following Ex&mples.
Any of the conventional pigments used in the
coating compositions can be utilized in this composition.
Examples of typical pigments that can be used are as
follows: metallic oxide, such as tit&nium dioxide, zinc
oxide, iron oxide and the like, metal hydroxide, metal
- flakes such as aluminum flake, sulfide, sulfates, carbonates,
carbon black, silica, talc, china clay, phthalocyanine blues
and greens, organo reds, organo maroons &nd other organic
dyes.
The coating composition of this invention
can be applied over a variety of substrates, such as
metal, primed metal, metal coated with en&mels
or lacquers, wood, glass, plastics, and the like,
by any of the conventional application methods, such
as spraying,electrostatic spraying, dipping, brushing,
flow-coating and the like. The viscosity of the compo-
sition can be adjusted ~or any of these methods by
adding solvents if necessary.
The applied coatings can be dried at ambient
temperatures or baked at relatively low temperatures of
about 35-100C. ~or about 15 minutes-2 hours. The
resulting finish is about 0.1-5 mils thick but ~or most
uses, a 1-3 mil thick finish is used. The resulting
-- 10 --
2 4~ 5
finish has good appearance and can be rubbed or pollshed
wlth con~entional techniques to improve the smoothness or
gloss or both. The finish has good adhesion to substrates
of all types particularly industrial lacquers or enamel
finished substrates. The finish is hard and resistant to
weathering, staining,scratches and the like. These charac-
teristics make the composition particularly useful for
finishing or refinish automobile and truck bodies. The
coating composition can also be used on aircraft, farm
equipment such as tractors, appliances, vending machines,
bridges, water tanks, gas tanks and the like.
The following Examples illustrate the invention.
All quantities are shown on a weight ba,sis unless other-
wise indicated
~ 2~35
EXAMPLE 1
- An iminated ac~ylic polymer solutlon
prepared by charging the following constituents lnto a
reaction vessel equipped with a thermometer,a stirrer,
a reflux condenser and a heating mantel;
Parts by
Portion 1. Weight
Toluene 54-79
Isopropanol 110.83
Ethyl Acetate 148.05
Methyl methacrylate monomer 254.08
Ethyl acrylate monomer 45.80
Met;hacrylic acid monomer 13.80
Azobisisobutyronitrile 0.73
Portion 2
Azobisisobutyronitrile 0.83
Ethyl acetate 6.70
Toluene 4.80
Portion 3
Azobisiobutyronitrile 1.26
Ethyl acetate 7.32
Toluene 13.60
Portion 4
Isopropanol 19.86
Toluene 104.55
Portion 5
Propylene imine 9.20
Isopropanol 13.80
Total810.00
Por~ion 1 is premixed and then is charged into the
reaction ~essel with constant mixing and heated.
_ 12 -
43S
and then the heat is turned off. The temperature of the
resulting reaction mixture rises to a reflux temperature of
about 82-84C and ls maintained at this temperature
by slightly refluxlng the mixture for about 60 minutes. Portion
2 is premixed and added to the reaction vessel and the
resulting reaction mixture is held at about 81-83C by
s~i~htly.refluxing the mixture for about 90 minutes.. Portion 3 is
premixed and.added to the reaction vessel and the resulting reaction
mixture is held at about 81-83C at; a slight reflux for
about 45 minutes. Portion 4 is added with mixing and then
Portion 5 is premixed and added and the reaction mixture is
thoroughly mixed for about 15 minutes and held at about 76-
80C for about 2 hours or until the acid number of the reaction ~
mixture reaches about 0.1-3.5 and then cooled to room temperature.
The resulting polymer solution has a solids content
of about 39% by weight, a Gardner Holdt Viscosity measured
at 25C of about W-Y and the polymer has the following compo-
.sition: methyl methacrylate/~thyl acrylate/methacrylic acid/
propylenimine in a weight ratio of 81.0/14.6/4.4/2.9 in
which all of the propyleneimine has reacted with the metha-
crylic acid. The polymer has a relative viscosity of about
1.2 measured on a 0.5% polymer ~solids solutio~Q using a
dichloroethylene solvent at 25C.
A butyl acrylate/methyl methacrylate
polymer solution is prepared by char.ging the following
constituents into a reaction vessel equipped as above:
Parts by
Portlon 1 Weight
Acetone 81.61
Toluene 82.00
Butyl acrylate monomer 58.7?
s
- Methylmethacrylate mQnomer 267.61
Benz~yl peroxide 1.61
Po~tlon 2
Benzoyl peroxlde ,0.72
Toluene 6.72
Portion 3
Toluene 317.12
Total 816.11
Portion 1 ls charged into the reactlon vessel and
heated to about 100C and held at thls temperature for about
1 hour and 20 minutes. Portlon 2 ls premlxed and added
to the reaction vessel and the resultlng reaction mixture
ls held at about 100C for about 20 minutes and then Portion
3 ls added.
The resulting polymer solution has a sollds
content of about 40% by welght and Gardner Holdt Viscosity
measured at 25~C of V-1/2 to W. The polymer contains
about 82% methyl methacrylate and 18% butyl acrylate and
has a relative vlscoslty measured as above of about
1.19.
A methyl methacrylate/diethyl amino
ethyl methacrylate copolymer solution is prepared by charging
the followlng constituents into a reaction vessel equipped
as above:
Parts by
Portlon 1 Weight
Methyl methacrylate monomer 322.15
Diethylaminoethyl methacrylate 3.25
monomer
Ace~one 115.40
Toluene 48.80
- 14 -
~ 2~4~5
Azobisisobutyronltrlle 1.09
Portion 2
Acetone 5-00
Azobisisobutyronitrile 0.55
Portion 3
Acetone 27.65
Toluene 293.10
Total 816.99
Port,lon 1 ls changed into a reaction vessel
equipped as above and heated to about 100C and held at
this temperature for about 1 hour. Portion 2 is added
and the resulting reaction mixture is held at 100C for
another hour. Portion 3 is added and the reaction
mixture is cooled.
The resulting polymer solution has a polymer
solids content of about 40% by weight and a Gardner
Holdt Viscoslty measured at 25C of about X-~2. The polymer
is ~9% by weight methyl methacrylate and 1~ butyl
acrylate and has a relative viscosity measured as above
of about 1.2.
A methyl methacrylate polymer solution is
prepared by charging the following constituents into a
reaction vessel equipped as above:
Parts by
Portlon 1 _ Weight
Methyl methacrylate monomer322.28
- 15 -
435
Acetone 112.71
Toluene 48.33
Benzoyl peroxlde 2.18
Portion 2
Acetone 32.29
Toluene 290.2g_
808.08
Portion 1 is premixed and charged into a reaction
: vessel and heated to about 100C and held at this temperature
~or about 1-1/2 hours and then Portion 2 is added and the
resulting pol~mer solution is cooled to room temperature.
The polymer solution has a polymer solids content
of about 40% by weight and the polymer has a relative
viscosity of about l,i9 measured as above.
A ~oconut 0il/ethylene glycol/phthalic
anhydride es~er resin solution is prepared by charging the
following constituents in a reaction vessel equipped as
abo.ve:
Parts by
Portion 1 weight
Coconut oil 275.70
Ethylene glycol 185.00
Dibutyltin oxide 0. 26
: Lead tallate drier 0.23
Portion 2
Phthalic Anhydride 394.70
Portion 3
Toluene 63.74
Portion 4
Toluene 75.36
Total 994.99
- 16 -
~L~ 2~43~
Portion 1 is charged into the reaction Vessel and
heated to 188C and held at this temperature for about 1
hour. Portlon 2 is then added and then the temperature of
the resulting reaction mixture is brought to 150C. Portion
3 is added and the reaction mixture is held at its reflux
temperature of about 190C for about 30 minutes and then the
temperature OL the reaction mixture is increased to about
200C and held at this temperature for 30 minutes. The reaction
mixture is heated to 232C and held for 2 hours at this tempera-
ture and then heated to 245C and held until the acid numberof the reaction mixture is below about 10 which usually takes
about 1 hour. The reaction mixture is heated to 250C and
held at this temperature for about 2 hours. During the above
reaction, water is removed from the reaction mixture.
Portion 4 is added and the resulting alkyd resin solution is
cooled to room temperature.
The ester resin solution has a solids content of
about 85% by weight and a Gardner Holdt Viscosity measured
at 25C of about Y-~l and the alkyd resin has an acid number
of about 7-10.
A white mill base is prepared by charging
the following constituents into a mixing vessel and then
grinding the mixture in a sand mill:
Parts by
Portion 1 weight
Methyl methacrylate/diethylamino
ethyl methacrylate copolymer 7.00
solution (prepared above)
Cellulose acetate butyrate(CAB)6.00
solution (25% CAB having a 38%
butyryl content and a 1 second
viscosi'y ir. a solvent of 5
parts toluene/2 parts acetone)
Toluene 18.05
Ethylene glycol monoethyl ether acetate 10.00
- 17 -
~ ~fl4~5
Portion 2
Tltanlum dioxide pigment 55.00
Portion 3
Ester resin solution (prepared ~ 3.95
above)
Total 100.00
Portion 1 is mixed for 15 minutes and then portion
2 is added and mixed for 1 hour and portion 3 is added and
mixed for 1 hour. The resulting mixture is ground 3n a
.sandmill.
An aluminum flake mill base is prepared by mixing
the following constituents.
- Parts by
PortiGn 1 Weight
Methyl methacrylate polymer 56.64
solution(prepared above)
Aluminum Paste (67% aluminum 12.12
flake in an aliphatic hydro-
carbon.)
Portion 2
Methyl methacrylate polymer 21.35
solution(prepared above)
Toluene 11.89
Total100.00
Portion 1 is added to a mixer and slowly mixed
for 3 hours and then portion 2 is added and mixed for 1 hour.
A white acrylic lacquer coating composition is
prepared as follows:
Parts by
Portion 1 Weight
Acetone 12.97
Ethylene glycol monoethyl 25.28
ethyl acetate
Toluene 33.18
Ester: resin solution 56.48
(prepared above)
- 18 -
~ 4~ S
Portion 2
~llicone solution (1% 0.25
solids silicone SF69 in
xylene)
Methyl methacrylate polymer solution 107.32
tprepared above)
Methyl methacrylate/diethyl 45.69
aminoethyl methacrylate copoly-
mer solution (prepared above)
Butyl acrylate/methylmethacrylate148.75
copolymer solution (prepared above)
Imi~ated acrylic polymer solution17.50
(prepared above)
Cellulose Acetate Butyrate solution 101.88
(described above)
High Molecular Wei~ht Cellulose124.45
Acetate Butyrate (CAB) solution (15%
solids CAB having a 38% butyryl
content and a 20 second viscosity
measured according to ASTMD-1343-56
at 25C in a solvent blend of 60 parts
acetone/25 parts toluene.)
Portion 3
White Mill base (prepared ab?ve)168.47
Total 842.22
The constituents of Portion 1 are added
20 in the order shown and mixed until uniform. Portion 2
is added and thoroughly mixed before Portion 3 is added
and mixed until uniform.
The resulting lacquer has a pigment to binder ratio
of 40/100. The binder is of 18.5 parts parts polymethyl metha-
crylate, 10.0 parts methyl methacrylate/diethylamino ethyl
methacrylate copolymer, 25.5 parts butyl acrylate/methyl
methacrylate copolymer, 23.0 parts of ester resin, 12.0
parts CAB having a 1 second viscosity, 8.0 parts CAB having
a 20 second viscosity and 3.0 parts of an iminated acrylic
polymer.
- 19 -
l~ Z9L435
A whlte acrylic lacquer B ls prepared identlcal to
the above lacquer A except the iminated acrylic polymer is
omitted and the butyl acrylate/methyl methacrylate copolymer
is substituted therefore.
A silver metallic acrylic lacquer C is prepared by
mi~ing together the following constituents.
Parts by
Portion 1 Weight
Acetone 22.11
Ethy~ene glycol aminoethyl 39.21
ether acetate
Toluene 51.60
Ester resin solution 59.09
(prepared above)
Portion 2
-
Silicone solution (1% 0.24
solids silicone SF69 in xylene)
4-dodecyloxy-2-hydroxy 6.96
benzophenne(DOBP U.V. Screening
agent)
Methyl methacrylate polymèr solution 18.40
(prepared above)
Methyl methacrylate/diethyl 62.16
aminoethyl methacrylate copolymer
solution (prepared above)
Butyl acrylate/methyl methacrylate 158.39
copolymer solution (prepared above)
Iminated acrylic polymer solution 18.63
(prepared above)
Cellulose Acetate Butyrate solution 169.08
(described above)
High Molecular Welght Cellulose49.73
Acetate Butyrate (CAB) solution
(1~% solids CAB having a 38% butyryl
content and a 20 second viscosity
measured according to ASTMD-1343-
56 at 25C) in a solvent blend of 60
parts acetone/25 parts toluene).
Portion 3
Alurllinum flake mill base 124.40
(prepared above)
3 Total 780.00
- 20 -
.z~s~s
The constituents of Portion l are added to a mixer
in the order shown with constant mixing and Portion 2 is
added and thoroughly m~ixed and then Portion 3 is added and
: thoroughly mixed.
The resulting lacquer has a pigment to binder ratio
of 4.07/100. The binder is of 18.5 parts polymethyl methacrylate
monomer, 10.0 parts methyl methacrylate/diethylamino ethyl
methacrylate copolymer, 2~.5 parts butyl acrylate~methyl
methacrylate copolymer, 20.2 parts of ester resin, 2.8 parts
DOBP, 17.0 parts CAB having a l second viscosity, 3.0 parts
CAB having a 20 second viscosity and 3.0 parts of an iminated
acrylic polymer.
A silver metallic acrylic lacquer D is prepared
identical to the above lacquer C except the iminated acrylic
polymer is omitted and the butyl acrylate/methylmethacrylate
copolymer is subst`ituted therefore.
The above prepared lacquers A,B,C and D are each
sprayed onto separate primed steel panels coated with baked
acrylic enamels and baked for 24 hours at 43C. to provide
a topcoat about 2 mils thick.
The adhesion of the topcoat to the substrate is
determined on a set of these panels by scribing a rectangular
grid through the topcoat to the metal with a knife and placing
scotch tape over the grid and then removing the tape. A sub~ective
rating of 10 means that none of the topcoat is removed while
a rating of 0 indicates that all of the topcoat is removed.
The panels are tested for initial adhesion, wet adhesion
after 96 hrs. exposure to 100% relative humid~ty at 38C and
recovered adhesion, i.e. the panel sub~ected to the wet adhesion
test is allowed to dry at room temperature for 24 hours and
then tested as above.
Several sets of panels were subjected to outdoor
- 21 -
s
weathering in Florida for a 3 month period and then tested for
adhesion as above. The results of these tests are s~mmarized
ln the following table:
Table
Initial Adhesior.* Wet Adhesion* Recovered Adhesion*
Start 3mo.Fla. Start 3mo.Fla. Start 3mo.Fla
Lacquers A+C 7.4 7.8 1.9 2.2 6.3 4.6
B+D 2.0 2.9 0.5 0 1.7 0.9
*(average of 16 data points)
The above results show that Lacquers A and C which
contain only a s,mall precentage of an ~m~nated acrylic polymer
have substantially better adheslon under all conditions that
do Lacquers B and D which do not contain an iminated acrylic
polymer.
EXAMPLE 2
The following constituents are blended together to form
a clear lacquer that will dry at room temperatures:
Parts by
Weight
Isopropanol 386.0
Acetone 464.0
Toluene 156.0
Xylene 276.0
Cellulose Acetate Butyrate 220.3
(having a butyryl content of
38% and a viscosity of 2
seconds measured as in Example 1)
Ethylene glycol monoethyl ether 232.0
acetate
~OBP U.V.~Screening agent 25.7
(described in Example 1)
Silicone solution (described 7.8
in Example 1)
3o Butyl cyclohexylphthalate 73.3
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435
Esterresin solution (prepared 197.0
ln Example 1)
Imlnated Acrylic Polymer solution 94.4
(prepared in Example 1)
Methyl methacrylate Polymer solution850.0
(prepared in Example 1)
Total 2982.5
The above lacquer is sprayed onto primed steel
panels coated with an acrylic lacquer ana primed steel panels coated
with an acrylic enamel and in each case dried at 43C for 24
hours. The adheslon of the lacquer on each of the substrates
is checked as in Example 1 and in each case the lacquer has
an acceptable level of adhesion to the panel, i.e. an adhesion
level of 7 and above when dry.
The application is a division of copending Canadian
Serial No. 306 669, filed 1978-06-30.
_ 23 ~ .
