AQUEOUS THERMOSETTING ACRYLIC ENAMEL

EMAIL ACRYLIQUE AQUEUX THERMOCURABLE

English Abstract

ABSTRACT OF THE DISCLOSURE

The aqueous thermosetting acrylic coating
composition contains the following film-forming
constituents:
(1) an acryllc polymer of styrene and/or
methyl methacrylate, sn alkyl acrylate or
an alkyl methacrylate other than methyl
methacrylate, a bydroxy alkyl acrylate or
a hydroxy alkyl methacrylate and an .alpha.,.beta.-
unsaturated carboxylic acid wherein the
polymer has an acid numbor of 35-150 and
carboxyl/hydroxyl ratio of 1:0.2 to
1:1.8; and
(2) a water soluble or water dispersible
alkylated melamine formaldehyde resin;

the novel coating composition is useful as an
exterior finish for automobile and truck bodies.

Claims

The embodiments of the invention in which an
exclusive property or privilege is claimed are defined as
follows:

1. An aqueous thermosetting acrylic enamel coating
composition comprises 10-60% by weight of film-forming
constituents and correspondingly 90-40% by weight of water
and up to 20% by weight of a solvent for the film-forming
constituents; wherein the film-forming constituents consist
essentially of
(1) 60-90% by weight, based on the weight of
the film-forming constituents, of an acrylic
polymer having a uniformity factor of at least 75%
and consisting essentially of
(a) 50-60% by weight, based on the
weight of the acrylic polymer, of methyl
methacrylate;
(b) 30-40% by weight, based on the
weight of the acrylic polymer, of butyl acrylate,
(c) 5-10% by weight, based on the
weight of the acrylic polymer, of hydroxy-
ethyl acrylate;
(d) 4-12% by weight, based on the weight
of the acrylic polymer, of acrylic acid or
methacrylic acid;
wherein 30-50% by weight of the
acrylic polymer is dispersod and has a particle
size of 0.01-0.10 microns and the remaining 50-
70% is soluble and dissolved and the polymer
has a carboxyl to hydroxyl ratio of 1:0.3 to
1:1.5 and an acid number of about 35-80 and
weight average molecular weight of 10,000 -
50,000 and

36

(2) 10-40% by weight, based on the weight of
the film-forming constituent, of a hexa(methoxymethyl)
melamine; and the composition is at least partially
neutralized with a water-soluble amino and has a
pH of about 7.1 - 7.5.

2. The coating composition of Claim 1 containing
0.1-40% by weight pigment and having a polymer solids content
of about 20-50% by weight.

3. The coating composition of Claim 2 in which
the acrylic polymer consists essentially of 54% methyl
methacrylate, 34% butyl acrylate, 6% 2-hydroxyethyl acrylate
and 6% acrylic acid and has an acid number of about 45-50
and a carboxyl to hydroxyl ratio of about 1:0.6.

4. The aqueous thermosetting acrylic enamel
coating composition of Claim 1 comprises 20-50% by weight
of film-forming constituents and correspondingly 80-50%
by weight of water and up to 20% by weight of a solvent for
the film-forming constituents; and additionally contains
about 0.1-20% by weight of pigment; wherein the film-forming
constituents consist essentially of
(1) 60-90% by weight, based on the weight
of the film-forming constituents, of an acrylic
polymer having a uniformity factor of 80-95% and
consisting essentially of
(a) 50-60% by weight, based on the
weight of the acrylic polymer, of methyl
methacrylate,
(b) 30-40% by weight, based on the
weight of the acrylic polymer, of butyl
acrylate;

37

(c) 5-10% by weight, based on the
weight of the acrylic polymer, of hydroxy-
ethyl acrylate;
(d) 4-12% by weight, based on the
weight of the acrylic polymer, of acrylic
acid or methacrylic acid;
wherein 30-50% by weight of the
acrylic polymer is dispersed and has a particle
size of 0.01-0.10 microns and the remaining 50-
70% is soluble and dissolved and the polymer
has a carboxyl to hydroxyl ratio of 1:0.3 to
1:1.5 and an acid number of about 35-80 and a
weight average molecular weight of 10,000-
50,000, and

(2) 10-40% by weight, based on the weight of the
film-forming constituent, of a hexa(methoxymethyl)
melamine; and
the composition is at least partially neutralized
with a water-soluble tertiary amine and has a pH of
about 7.1 - 7.5.
5. A metal substrate coated with about 0.5-3.5 mils
of the dry coalesced layer of the coating composition of
Claim 1.

6. A ferrous metal substrate having a pigmented
primer coating and a finish layer about 0.5-3.5 mils of the
dried coalesced coating composition of Claim 1.
7. A plastic substrate reinforced with glass
fibers coated with 0.5-3.5 mils thick dried layer of the
coalesced coating composition of Claim 1.

38

8. A process for preparing a coating composition
of an acrylic polymer of 52-56% by weight of methyl meth-
acrylate, 32-36% by weight of butyl acrylate, 5-7% by weight
of hydroxy ethyl acrylate and 5-7% by weight of acrylic acid;
the acrylic polymer having a uniformity factor of at least
75%, carboxyl to hydroxyl ratio of 1:0.2 to 1:1.8, an
acid number of about 35-80 and a weight average molecular
weight of about 10,000-50,000 comprising the following steps:
Step (1)
Charging the following constituents into a
reaction vessel and heating the constituents to reflux
temperature:
13-15% by weight of said total amount of methyl
methacrylate,
52-54% by weight of said total amount of butyl acrylate,
28-30% by weight of said total amount of hydroxy ethyl
acrylate
23-25% by weight of said total amount of acrylic acid,
water miscible solvents and a chain transfer agent;

Step (2)
Charging the following constituents into the reaction
vessel and maintaining the reaction mixture at a reflex
temperature:
a polymerization catalyst,
14-16% by weight of said total amount of methyl
methacrylate;
Step (3)
Charging the following constituent slowly and
continuously into the reaction vessel over a 14-16 minute
period:

39

20-21% of said total amount of methyl methacrylate,
13-15% of said total amount of butyl acrylate,
31-33% of sald total amount of hydroxy ethyl acrylate,
22-24% of said total amount of acrylic acid, and
polymerization initiator and maintaining the
reaction mixture at a reflux temperature for
about 10-20 minutes;
Step (4)
Charging the following ingredients slowly and
continuously into the reaction vessel over a 49-51 minuto
period and maintaining the reaction mixture at a reflux
temperature,
31-33% of said total amount of methyl methacrylate,
20-22% of said total amount of butyl acrylatc,
31-33% of said total amount of hydroxy ethyl acrylate,
33-35% of sald total amount of acrylic acid, and a
polymerization initiator;
Step (5)
Charging the following ingredients slowly and
continuously into the reaction vessel over a 75-80 minute
period:
17-19% of said total amount of methyl methacrylate,
11-13% of said total amount of butyl acrylate,
6-8% of said total amount of hydroxy ethyl acrylate,
17-19% of said total amount of acrylic acid
and a polymerization initiator maintaining the reaction
mixture at a reflux tomperature for about 25-35 minutes to
form said polymer;
Step (6)
Adding a sufficient amount of an amine to said
polymer to provide a resulting pH of about 6-9 and then
adding water to provide an aqueous coating composition.

Description

~! :
1~38~
BACKGROUND OF THE INVENTION ~f~

This invention relates to an aqueous based ~ :
coatlng compositlon and in particular to an aqueous
thermosetting acrylic enamel that provides a high quality ~ :f
finish for the exterior of automobile and truck bodies.
Thermosetting acrylic enamels are well known in ~ :~
, ~
., the art as shown by Frazier et al. U.S. Patent 2,681,897
issued June 22, 1954; Vasta U.S. Patent 3,338,860, issued
August 29, 1967; Fisk ~t al. U.S. Patent 3,365,414, issued
.~ 10 January 23, 1968; Vasta U.S. Patent 3,622,651, issued
November 23, 1971; and Parker U.S. Pate~t 3~637J546~
:,~ .
issued January 25, 1972. These acrglic enamel~ are all
X~ solvent based systems and do not provide a non-air-polluting
~ finish. Ta~t U.S. Patent 3,661,827, issued May 9, lg72 is
,1 : " ':
directed to a process for preparing a water disper~ible
acrylic enamel composition but this product doe~ not meet
.:~ the needs of the automobile and truck manufacturing
industry for a high quality water based finish. ~;~
The novel aqueous thermosetting acryllc enamel .:,
~ 20 coating composition of this invention utilized a particular .. :
,b, acrylic polymer having a uniform composition and haYing a ~.
q balance of hydroxyl and carboxyl groups in combination with
a water disperslble or water s~luble cross-linking agent
.
such as an alkylated melamine formaldehyde resin to form a ~ ::
high quality finlsh useful for the exterior of auto~obile
and truck bodies.
,, -




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1(~3852;i~ `
SUMMARY OF THE INVENTIO~

The aqueous thermosettin~ acrylic enamel coating
composition comprises 10-60% by welght of ~llm-~ormlng
constltuen~s and correspondingly 90-50% by weight o~ water : ~ :
~ 5 ~nd up to 20% by weight of a so~.vent ~or the film-forming
;~ constituents; whereln the film-ro~ming constituent~ consis~ - -
essentially o~
(1) 60-go~ by weight, based on the weight of the -
film-forming constituents, of an acrylic polymer
. 10 havin~ a uniformity factor of at least 75~ which
consist& essentially of
a) ~0 60~ by weight, ba~ed on tho
weight of the acrylic polymer, of a hard ; .
constituent which ls elther methyl
~ methacrylate. or a blend of methyl : ~:
.~ 15 methacrylate and ~tyrene wherein the
~ ~tyrene comprlse~ up to 40~ by weight ~
~ o~ the acrylic polymer; ~ :
. tb) 20-40% by weight, ba~ed on the
weight of the acrylic polymer, of a 50~t
`~ 20 acrylic constltuent that i8 either an alkyl
acrylate havlng 2-12 carbon atoms in the
/ alkyl group, an alkyl methacrylate havlng ;`
¦: . 4-12 carbon atoms in the alkyl group, or
:`? ~`
~ ~ mlxture of the above alkyl acrylate and
~ 25 alkyl methacrylate; -:
.:, (c) 4-20~ by weight, ba~ed on the weight
.J o~ the acrylic polymer, o~ a hydrox~-containlng .-~
~ constituent which is either a hydroxyalkyl ~.
-~, ~ethacrylate or a hydroxyalkyl acrylate or a
~;30 mixture thereo~ ln whlch the alkyl groups :.
have 2-4 carbon atomfi,
~, .

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(d) 4-20~ by welght, based on the weight
o~ the acrylic polymer, o~ a,~-uns~turated
carboxylic acld;

wherein the polymer has ~ carboxyl to
hydroxyl ratio of 1:0.2 to 1:1.8 and
an acid number of about 35-150 and a welght
average molecular weight of 5,000-80~000;
.'t and
,~t' ,`'' ,'',
(2) 10-40% by wei~ht, based on the weight of
;,:, . . .
the film-forming constituentJ of a water dispersible !~
or water soluble cross-linking resln, preferably,
an alkylated melamine ~ormaldehyde resin having
1-4 carbon atoms in the alkyl group; and
the compositlon is at least partiall~ neutrallzed
i `15 with a ~ater-soluble amine and ~as a pH o~ about ~-9.
"J. ~', , ' '; ': ' '

DESCRIPTION OF THE I~VE~ION

The novel coatlng composition Or this inventlon has
a sollds content o~ ~llm-formlng constituents of about 10-60%
,
by weight and preferably about 20-50~ by weight. The novel
20 composition is usually pigmented and contains about 0.1-40%
1,"
~ by weight o~ pigment and preferably, 0.1-30% by weight ;~
`~ pigmen~
The fllm-forming constituents of the novel coatlng
composition comprise 60-go~ by weight o~ acryllc polymer and
25 correspondingly, 40-10~ by weight of a water dispersible or .~r `
water soluble cross-linklng resin, preferably an alkylated
melamine ~ormaldehyde resin whlch is compatible with the
acrylic polymer i8 u8ea. Pre~erably, the novel compositlon

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'~ contains 65-85~ of the acrylic resin an~ ~5-15~ by weight of an alkylated melamine formialdehy~e resin and more
preferably about 70~ by weight of the acryllc polymer is
used ln combination with about 30~ by weight of an alk~lated
,~ 5 melamine formaldehyde resin.
'J~ The acrylic polymer used in the novel coating
compositlon of thls invention is partially soluble and
partially dispersed in the aqueous medium. About 30-5Q~
by weight o~ the acrylic polymer is dispersed and has a
particle size of about 0.01-0.10 mlcrons preferably about
0.02-0.06 microns and the residual 50-70~ by weight of the
¦ acrylic polymer is soluble and dissoJ.ved ln the aqueous
medium. To obtain w~ter solubility and disperslbility the
~! &cryllc polymer has a carboxyl to hydroxyl ratio of 1:0.2
to 1:1.8 which i6 the molar ratio of carboxyl groups to
! hydr~xyl groups of the polymer.

~, The acrylic polymer used in the novel coating
composition of this invention has a uniformity factor of
at least 7~ and preferably 80-95~. The uniformity factor
is the per cent o~ the polymer in which the constituents are
within plu5 or minus 15~ of the average amount given for
the polymer~ For example, if the average composition of the
acrylic polymer i8 54% methyl methacrylate, ~4% butyl
acrylate, 6~ 2-hydroxyethyl acryla~e and 6% acrylic acid,
25 75% o~ the polymer will be within plus or minus 15% of ^
these average values or 54 ~ 8~ methyl methacrylate,


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10385Z2
34 ~ 5% butyl acrylate, 6 -~ 0.9~ ~-hydroxyethyl acryl~te,
and 6 + 0.9% acr~lic acid.

The acrylic polymer utilized ln the novel composi- I
tion Or this inventlon i8 prepared by a progra~med addition ~ ~ -
of the monomers, polymerization catalyst~ ~nd 801vent8
This programmed addltlon process is an attempt to form
polymer at all stages of the polymerizat~on proce~s which
is essentially the same as the predetermined compos~tion,
and re~ult~ ln a pol~ner composltion upon completion of
the process which has a uni~ormity factor o~ at least 75%.
This proce6s allows ~or high percentage conver~lon of ;-
monomer~ to polymer and ~lso provides a polymer h~ving a
relatively uniform molecular weight. These polymer~ wh~n
used in the novel composition of this invention pro~ide
hlgh quality finishes.
Cpnventional polymerization proce~6e~, ~uch a~
batch polymerization, commonly used ln the art provide ~~
polymer~ ~ith a wide range o~compoæitions and molecular
weights which are not ~ultable for the novel coating
composltion of this lnventlon.
The above programmed addltion polymerization
1 process ls baged on a computer program which uses known
polymerlzation equations and activity ratlog o~ monomers
to determine the monomer additlon rates and ratio6 and
` polymer polymerizatlon temperatures and times. Thls ~orms
,,! a polymer that has a uniform composltion throughout. The
bove programmed addition procedure can be based on a
computer program which u~es a polymerization equation in
which the polymeriza~ion values of the monomers are used.
~o ~n general, the programmed polymerlzation procedure
comprises an initial charge of monomers and solvent~ which
, ~
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10;~195ZZ ~ ~
are heated to the reflux temperature in the polymerization
vessel, then at glven lntervals monomers and polymerlzatlon
inltiator are charged into the vessel while maintaining
a re~lux temperature according to the programmed polymerlza-
tion procedure. Throughout the polymerization reaction,
the polymer being for~ed has a uniformity factor o~ at least
` 75~ In general, the polymerlzatlon ls conducted at about ;
; 75-125C. over a 2-4 hour period to ~orm a polymer that has
'~ a weight average molecular weigh~ of about 5,ooo-80~000, -
and preferably, about 10,000-50,000 determined by gel per- :
meation chromotography. The polymer has an acid number of -
about 35-150, preferably about 35-80. ~;
In one preferred process which prepares a polymer
o~ 52-56~ by weight methyl methacrylate, 32-36% by weight ;
butyl acrylate, 5-7~ by weight of hydroxyethyl acrylate and
5-7% by weight of acrylic acid, the constituents are
J reacted as follows:
Step (1)
.-.~ . .
! The following constituents are charged into a
,:.j .
;~ 20 reaction vessel and are heated to reflux temperature:
; 13-15% by weight of the total amount of methyl
methacrylate,
52-54~ by weight of the total amount o~ butyl acrylate, `~
28-30% by weight of the total amount of hydroxy ethyl
acrylate, ~ ~
23-25% by weight of the total amount of acrylic acid, ~ ~ -
l, water miscible solvents such as isopropanol and
ethylene glycol monobutyl ether and a chain
trans~er agent such as lauryl mercaptan.

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s~ep (?~
The following lngredlents are then charged into
the reaction ve~æel~
polymerlzation catalyst ~uch as b~nzoyl peroxlde
and optionally,
14-16% by weight of the total amount of methyl .
methacrylate,
3 the addition o~ the methyl methacrylate in thiæ ~tep ~;
is optional since this amo~nt of methyl
methacrylate may be added in the fir~t ~tep
and a solvent may be used ~or the benzoyl - ~.
peroxide.
Step (3)
The ~ollowing ingredlents are then slowly and
j continuously charged into the reuction vessel over a
1 14-16 minute perlod
¦ 20-21~ o~ the total amount o~ me-thyl methacrylate,
. 13-15% of the total amount of7 butyl acrylate, `~
31-33% of the total amount of hydroxy ethyl
:~ 20 acrylate, ;;~
22-24~ of the total amount of acrylic acid, and ~.
polymerization inltiator of benzoyl peroxide and ;
maintaining the react~on mixure at a reflux
temperature ~or about 10-20 minutes.
Step (4)
!~ , The ~ollowing ingredients are then slowly and
continuouæly charged into the reaction veæsel over a 49-51 ~ -~
minu~e period while maintaining the reactlon mix~ure at a
re~lux temperature,
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31-33~ of the total amount of methyl methacrylate~
20-22% of the total àmount of butyl acrylate,
31-33% o~ the total amount of hydroxy ethyl acrylatej
33-35~0 of the total amount of acrylic acid, and
polymerization initiator of benzoyl peroxide~


Step (5) ~ ;
, ~
The ~ollowing ingredients are then slowly and
continuously charged into the reaction vessel over a 75-80
minute period~
17-19~ of the total amount of methyl methacrylate,
, . . 11-13% of the total amount of butyl acrylate,

6-8~ of the total amount of hydroxyethyl acrylate,

17-19~ of the total amount of acrylic acld, ~`~

and polymerlzatlon initiator o~ benzoyl peroxide; `;
. ,, ~ .
the reaction mixture is held at reflux temperature for ~ ; f

~ about 25-35 minutes to form a polymer.


.SIf Step (6)
. ~ i ~, . .
Tne polymer is then neutralized with an amine and

3 then di}uted with water to form a dispersion.
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Water miscible solvents are used in the polymeriza-

3 tion process such as isopropanol n-propyl alcohol, diacetone
':`~ ~, . ..
alcohol and other alcohols, acetone, acetyl acetone, ethylene
glycol monoethyl ether, ethylene glycol monobutyl ether and
ethylene glycol monomethyl ether acetate. Minor amounts o~
solvents of limited water solubility can be used such as methyl
:,
ethyl ketone, ethylene glycol monoethyl ether acetate. The



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i novel composition can contain up to ~bout 20~ by weight o~
w~ter miscible solvent but preferably contains 5-15% by weight
of ~olvent. If desired the novel composition may be made ;~
solvent free.
- 5 About 0.1-4~ by weightJ ba~ed on the weight o~ the
~ monomer used to prepare the acrylic polymer,o~ the polymeriza-
J tion catalyst iB utilized~ T~pical catalysts are azo-bis-
obutyronitrile, azo-bis-t~, ~~dimethylvaleronitrile),
benzoyl peroxide, t-butyl peroxypivalate, t-butgrl peracetate
and the llke. Chain transfer agents such as lauryl mercaptan
are also used. ;

il The acrylic polymer contains 20-60% by weight of
,' a hard constituent which can be methyl methacrylate or a
mixture of methyl methacrylate and styrene; up to 40% by
15 welght of the polymer can be styrene. The acrylic polymer can ~ -
contaln 5 to 30% by weight of styrene in combination with 15
to 30~ by weight of methyl methacrylate. Preferabl~, the
polymer contains about 52-57% by weight of methyl methacr~late.
~ The acrylic polymer contains 20-40~ by weight of
.. , 20 ~ so~t acrylic constituent whlch is either an alkyl acrylate ~ `
-~ that has 2-12 carbon atoms in the alkyl group, an al~yl ~ -~
methacrylate having 4-12 carbon atoms ln the alkyl group or
~ a mixture o~ these two constituents~ Pre~erab}y, the -
?j acrylic polymer contains 28 to 38% by weight o~ the
1 ?5 ~o~t acryllc con~tituent, preferably, an alkyl a~rylate
;; having 2-8 carbon atoms in the alkyl group. The followin~
are typical so~t acrylic monomers which can be utilized:
~; ethyl acrylate, propyl acrylate~ isopropyl acrylate, butyl
.... .
~ acrylate, isobutyl acrylate~ hexyl acrylate, 2-~thylhexyl
... .
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1038522
~crylate, octyl acrylate, nonyl acrylate, lauryl acrylate and
the llkeJ butyl methacrylate, lsobutyl methacrylate, pentyl
meth~crylate, hexyl methacrylate, octyl meth~crylate, 2-ethyl-
hexyl methacrylateJ decyl methacrylate, lauryl methacrylate
and the like. But~l acrylate i~ the pre~erred 30ft acryllc
con~tituent since it forms a hlgh quallty polymer that has
excellent physlcal properties.
The acrylic polymer contain~ 4-20% by weight o~ a
hydroxy containing constltuent 8uch as a hydroxy alkyl ¦~
acrylate or a hydroxy alkyl methacrylate or a ml~ture o~
these two compound~. Preferably, the polymer contains about
5-10~ o~ the hydrox~l containing con~tituent. These
~ constituents contain 2-4 carbon atoms in the alkyl groups and
``I are, ~or example, hydroxyethyl acrylate, hydroxybutyl
i, 15 acrylate7 hydroxyethyl methacrylate, hydroxypropyl methacrylate,
~ ~and hydroxy!Du~yl me~nacryia~e.
-~ The acrylic polymer also contains 4-20~ by weight,
based on the weight of the acrylic polymer, of an a,~-
unsaturated carboxylic acld. T~plcally useful acids are
' 20 acrylic acid, methacrylic acid, crotonic acid, itaconic acid,
; propyl acrylic acid, and the like. Pre~erably, acrylic
acid and methacrylic acid are used in amount~ of 4-10~ by
weight since these aclds form high quality polymers use~ul
in the novel compo~ition of this lnvention.

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One pre~erred acrylic polymer used in the novel
coating composition of this invention contains 50-60~ by
: weight of methyl methacrylate, 30-40~ by weight of a soft
: acrylic constituent, preferably butyl acrylate, 5-10% by
,
welght of the hydroxy containing constituent, preferab~y -
hydroxyethyl acrylate or hydroxypropyl methacrylate, and
4-12~ by weight of acrylic acid, methacrylic acid, or
itaconic acid. These preferred acrylic polymers have a
. . . .
I weight average molecular welght of about 20,000~50~000,
l an acld number of about 35-100 and a carboxyl to hydroxyl
I ratio of about 1:1.03 to 1:1.5.

Another particularly use~ul acrylic polymer which ~.;
.. gives a high quality ~inish contains about z8-~o~ by weight
- of styreneJ 22-26% by weight of methyl methacrylate, 30-35%
:1 by weight of butyl acrylate, 7-9% by welght of hydroxy ethyl ~-
acrylate and 4-6~ by weight of acrylic acid and has an acid
number of about 30 to 50, a carboxyl to hydroxyl ratio of- :~
. 1:0.4 to 1:1.5 and a weight average molecular weight of about
i 20,000-50,000.
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To form the aqueous dlspersion) the acrylic i~
polymer is at lsast partially neutrali~ed wlth a water- ~
soluble amine and then dlspersed in water. ~yplcal water ! : ~:
soluble am~nes that can be used are primary ~mines, secondary
! 5 amines, tertlary amlnea, polyamlnes and hydro~yamines, such
a8 ethanolamlne, diethanolamine7trlethanolamineJ n-methylethanol
amine, N,N-diethylethanolamine, N-amlnoethanolaminel N-methyl-
t diethanolamine~ monoisopropanolamine, dii~opropanol~mine~
triisopropanolamine, hydroxyamlne, butanolamine, hexanol~
amine, methyl diethanolamine, N,N-diethylaminoethylamine,
ethylene diamine, diethylene triamine, diethylene tetramine,
.. ~ , .
hexamethylene tetramine, triethylamine and the like. The
acrylic polymer i8 usually 50-60~ neutralized and can be 100~
neutrallzed. Neutralizatlon of 50-60~ is preferred since this
d~g~e~ of ~utralization ~orms an a~ueous d~per~ion whleh
`~ permits enamel formulation at high solids. The pH o~ the

`l resulting aqueous coating composition is generally ad~usted
~ to a pH o~ 6-9, preferably 7.1-7.5.
,: .
!~ The novel coating composition of this lnvention
` :'~
contains 10-~0~ by weight, based on the weight of the film-
forming constituents, o~ a water dlspersible or water soluble
cross-linking resln. Preferably, alkylated melamine formaldeh~de
r0s1ns are used ln an amount of about 20 40~ by welght of this ~;
resin. The alkylated melamlne formaldehyde resin has 1-4
?5: carbon atoms in the alkyl group and is prepared by conventional
, . . . .
techniques ln which an alkanol such as methanol, ethanol,
propanol, isopropanol o~ butanol is reacted with melamine
formaldehyde resln. One preferred resin ls hexamethoxymethyl
`~ ~ melamine. Melamine formaldehyde resin reacted with isopropanol
is another useful res1n. Urea ~ormaldehyde resins can ~l~o be
used as a cross-linklng resin.
_ 13
f
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.. .. . .. . . . .

~; Generally the novel coating compo~ition of thi~
invention contains pigments in amounts of 0.1-40~ by weight~
A wide variety of pigments can be used such as metallic
: : :
oxide~, for example, titanium dioxide~ iron oxide, zinc
oxide, and the like, metal hydroxide3, metal ~lake3, metal
~; powders, chromates~ sul~ates, carbonates, carbon black,
- ,
silica, t~lc, phtalocyanine blues and greens, indolinone
pigments and other organic pigments and dye~
The novel coat~ng composition of this invention
can be applied to a var~ety of substrate~ such as glass,
plastic substrate3 reinforced with glass ~ibersg metal and
the like, by any of the usual application methods such as
~ spraying, electrostatic spraying, dipping, brushing, ~low i
- coating and the like. These coatings are baked according ; ;~
to conventional procedures. One preferred baklng cycle
comprl~es ~ prebake at about 75-95C, ~or about 5-30 mlnute~ ~;
~ and then a bake at about 125-200C. to provide a high quality
.. ~ , , ,i~ finish. The re~ulting finish is about 0.5-3.5 mlls thick,
preferably 1-2.5 mils in thickne~q, and can be rubbed or
~ 20 polished in accordance wlth conventional techniques to lmprove
j smoothness or gloss or bothO
-i The novel coating composition of this invention is
preferably applied over a primed metal substrate. Typlcal
alkyd primers and epoxy primers pigmen~ed with iron oxide,
carbon black~ titanium dioxide can be used. The primer can
be applied by electrodeposition or can be applied by conven~
~ tional spraying or dipping of the metal substrate, Also~
`~ the novel composition can be used directly Gver galvanized ~;~
steel to form a durable coatlng.
The novel composition of this invention can be -~
applied directly over a primed metal substrate without the
use o~ an intermediate sealer coat. However, a sealer coat
j 14

., .
.~ ~
r

~ ~Q38:~ZZ
can be used to provide a finish with excellent ~dhesion and
smoothness. These sealers may be water based or solvent
~ .
based. One typlcally useful sealer composition is disclosed
in Rohrbacher U.S. Patent 3,509,086, issued April 2~, 1970. '

The ~inish of the novel coating compositlon of
this invention is characterized by a glossy and smooth
appearance that has water spot resistance, excellent craze
resistance, good durability and weatherability and gloss
retention and has good gasoline resist~nce. These charac-
, 10 teristics make the novel composition particularly attractive
~, as an exterior finish for automobiles and trucks.

' The ~ollowing Examples illustrate the inventlon.
i~ The parts and percentages are by weight unless otherwise
', specified.


'i' / ~

,', '



i -,




,j .
'''', ,
i,
`i
,;
_ 15 _


A coating composition i8 prepared by ~ir~t If ~1
: formlng the following acrylic polymer ~
Part6 By ¦,
5Weight
Portion 1 `~1
.
. Methyl methacrylate monomer 170080 i,:~ ~
j,:
Bu~yl ac~r}ate monomer l9ol~0
~ 2-Ethyl hexyl acrylate monomer 2.720 ~ :~
,~, 10 Acryllc acid monomer 1.150
Isopropanol 6,140 .- ;~
~;: Ethylene glycol monobutyl ether 9.680
Lauryl mercaptan 0.294 `:~
Portion 2
.. . .
Benzoyl peroxlde 0.672
I Methylethyl ketone 1.580
j Ethy~.en~ ~1ycol monomethyl ~her ~ce~te1~580
:~ Ethylene glycol monobutyl ether 2.360
~ Portion
:~, 20 Methyl methacrylate monomer 24.530
Butyl acrylate monomer 11.520
'~ 2-Hydroxyethyl acrylate 3.910
Acr~ylic acld 2.090
Benæoyl peroxide 0.906
Isopropyl alcohol 3.000
.~ Ethylene glycol monobutyl ether 9.800
~; Portion 4
: Methyl methacrylate monomer 25.720
Butyl acrylate 12.080
i~ 30 2-Hydroxyethyl acrylate monomer 4-090
j Acrylic acid monomer 2.200

,1 `
.,


' - 16 _
.,.

~ 2Z ~
- Parts By
Wei~ht
Portion 4 (Continued)
Benzoyl peroxide 1.248
Iqopropanol 4.120
Ethylene glycol monobutyl ether 1~ o l50
i Portlon~
Ethyl methacrylate 9.570
Butyl acrylate 4.~90
2-Hydroxyethyl acrylate 1.520
Acrylic acid monomer 0.820
Benzo~l peroxide 0.440
Isopropanol 1.460
Ethylene glycol monobutyl ether 4.760
Portion 6
Diethylethanoli~mine 7.900
' ~smineral~zed ~a~er 101,~0
-; Portion 7
I
Deminer~lized water l69.ogo
Total 4920100

Portion 1 ~s charged into a reaction vessel
equlpped wlth a stirrer, a heating mantel, and a re~lux
condenser and then heated to the re~lux temperature which i8
about 160C. Portion 2 is premixed and then added and then
~ 25 Portion 3 is premixed and added at a unlform rate over a 20-
I minute period, while maintaining the reaction mlxture at its
~1~ - re~lux temperature. Portion 4 1~ premixed and added at a
`1 uniform rate over a 60-mlnute period whi-e the reaction mixture
is maintained at lts reflux temperature. Portion 5 is premlxed
.,, ~


.,
.
i
- ~ 17
`:

,.i
... . .. . . . . .
. .. . :

1~3~5ZZ
and added at a unlform rate over a 100-minute periodJ then
the reaction mixture i~ main~ained at lts re~lux tempera~
ture for an additional 1/2 hour. Portion 6 i8 premixed and
then added to the reaction mixture and then Portion 7 is
added to the reaction mixture and the reactLon mixture is
cooled to room temperature and filtered to remove any
` coagulum.

- The resulting polymer disperslon ~las a 34~ polymer
~olids content in which the particle size is about 0.02-0.06 `
,~ 10 microns. The polymer has a relative viscosity of 1.16
measured at 25C. in dimethyl formamide at about 0.5~ polymer
solids and has an acid number of about 3~ to 35 and ~
carboxyl to hydroxyl ratio o~ 1 to 1~5. The polymer has the
~ollowing composition: methyl methacrylate/butyl acrylate/
'~ 15 2-hydroxyethyl acrylate/acrylic acid in a weight ratio o~
, about 54.2j33.1/8.4/4.3 and uniformity ~actor of about
, 75-85%.
' A phthalocyanlne blue mill base is prepared as
follows:
' 20 Parts By
Weight
Portion 1
Hexa(methoxymethyl) melamine 546
Isopropanol 630
Portion 2
Phthalocyanine blue pigment 210
Portion 3
Hexa(methoxymethyl~ melamine 285
Isoprop~nol 426
, 3 Total 2097

.
.'! '

'i '; ''
-- 18
,:
.:, .
`, ~ , ~ ; , i ` '

Portion 1 i8 mlxed wlth Portion 2 over a 30 ;~ ` :
. minute per~od and then Portion 3 i~ added and the constituents
`;, are mlxed ~or 30 minutes. The resulting composition 1~
passed through a standard Qand mill and ground two passeg
~, to provlde a uni~orm mill base. ~ Y ~ .

A blue mlll base i~ prepared a~ follows~
Part By
Welght
Portion 1
Hexa(methoxymethyl) melamine 78 ;
Isopropanol 90
Portion 2
MONASTRAL* blue pigment 30




Portion 3 . ~
Hexa(methoxymethyl) melamine 41 ~ ;:
Isopropanol 61
Total 300 ~ :
Portion 1 i~ mixed with Portion 2 over Q 30-mlnute .~
. . ~
period ~nd then Portion 3 i~ ~dded and the constituents are
mixed for 30 minutes. The result~ng composltlon is pas~ed :~

. through a ~tandard sand-mlll and ground ior two passes to
provide a unl~orm bl~e mill base.

A vlolet mill ba~e is prepared as follows~
.. ~ ~
,
.
* denotes trade mark ;~
.,

; ~ ::
' ~:

- 19~

: . : ,-~



. . ,,~,~ . .

9.~)38~æ2 Pw~ri~
.~. ,. ~ .
Portion 1 :~
~ . ~- .
Hexa(methoxymsthyl) melamine 13.6
I~opropanol 45,1
Portion 2 ~::
.
~s MONASTRAL violet plgment 7.0 ~
;l Portion 3 ;
.~ . ".-.
Hexa(methoxymethyl) melamine 7.6
Isopropanol 26.7
Total lOO.O i~
.i i ~ .
Portions 1 and 2 are blended together and then mixed ~:~
~r~for 30 mlnutes and then Portion 3 i5 added and the composltlon
is mixed for an additional 15 minutes. The resulting
composition is then ground two pa~se~ ln a ~tandard sand-
grindlng mill to form a un~form mill base.
~A green-yellow mill base i8 formed as follow~
:~Part~ By -:
Welght . ~ -
Portion I
Hexa(methoxymethyl) melamine 78 ;:~ ;
I~opropanol 90
Portion 2 '. -:
I Phthalocyanine green-yellow pigment 30 :~
.~ Portion 3
~3l Hexa(methoxymethyl) melamine 41
Isopropanol 61
Total 300

. ~ 1~ ' ~ . . .


~ - 20 - ~
''~ " i :, '
~' ' ' ',''-


,, ~, ,.. - ~ . . - "' .:~'

.10Jtl52Z I ~
; Portion 1 i8 blended with Portlon 2 ln a mlxing
- vessel ~or 30 minutes and then Portion 3 is added and
blended to an additional 15 minutes. The resultlng
composltion is then ground two pas~es in a standard s~nd-
grinding mill to form a unlform mill bQse. ~ ~ :
An aluminum flake disperslon is prepared as
follows:
Parts By
- Weight -~ .
; 10 Aluminum flake 1~71
,~ ,
Hexa(methoxymethyl) melamine 5~75
I~opropanol 11.05
Total 18.51
I
The above con~tituents are thoroughly blended
, 15 together ~or 30 mlnutes to form a unl~orm disperslon.
!
. A paint composition is prepared by blendlng
. ~ , . together the following ingredients: .
Parts By
_Weight
Portion 1
i Phthalocyanine Blue mill base
. (prepared above) 6.35
l Blue mill base (prepared above) 0.20
.1 Vlolet mill base (prepared ~bove) 0.70
., Phthalocyano green-yellow mlll ba~e (prepared
.'., 25 above) 45
1 Aluminum flake mill base (prepared above)11.05 ~ ~;
;' Portion 2
.
Hexa(methoxymethyl) melamlne 2Q.40 : :
Portion 3
.~ 30 Acryl1c polymer dispersion (prepared above) 272.40
;~
~ .
.

.j .

,.

- 21 ~


: . - ~ -.

- 103~2Z Parts By
Wei~ht
Portion 4
Deionized water 18.00
Portlon 5
.: Butyl acrylate/acrylic acid copolymer .;
~olution - (80~ polymer solids in alcohol
- of an 85/15 butyl acrylate/acrylic
acid copolymer) 3-3
~ 10 Silicone anti-cratering agent solution
: ~10~ low molecular weight silicone
resin in water) 3.35
. Deionized water 31.00
~- Total 367010 : .
;
~ 15 Portion 1 is charged in a mixing vessel and
, thoroughly blended together and then Portion 2 is added
;l then blended with Portion 1 and Portions ~, 4 and 5 are
, added consecutively wlth blending a~ter each addition, The
,, resulting composltion has a ~0 second viscosity using a :
' 20 No. 2 Fisher cup and a total solids content o~ 28,1

.3 A standard suction gun is used to apply the paint ~
.,' composition at an air pressure of about ~0 pounds. The .~:
1 composition is applied to a steel panel primed with 1.5 mil
. '
thick iron oxide pigmented alkyd resin primer. Six passes
~, 25 are used to apply the paint applied and the panel is prebaked
for 15 minutes at 90C0 and then baked for 30 minutes at 150C. ~ ~;
~ . .
The resulting ~ilm is about 2 mils thick and has
j good gloss~ excellent hardness, excellent appearance, and is .:
.~, resistant to blistering at high humldity, hsas excellent
i, 30 resistance to water spotting good chip resistance, good
. gasoline resistance and excellent resistance toward deteriora- :~
,~j ,
.~ tion by weatherling.

:

- 22 -
., -,
, 1 ,
''
:, ` ,, ! , ... , ', ~ ' , .. ' , ' ,' '

103852Z ~:
. EXAMPLE 2 ~: ~
~:
A coatlng compositlon ls prepared first by ~orming : ~:
the follo~ing a~rylic polymer solution; `:
Parts By ` ;~ `
Weight : :~
.. ' 5 :
-, Portion 1 :
j Methyl methacrylate monomer s8.0 ~
Butyl acrylate monomer 98.o :;
~ 2-Hydroxyethyl acrylate monomer 9.0 :
:, 10 Acrylic acid monomer 8.o :
opropanol 30.0 I
, Methylene glycol monobutyl ether 75.o ~ :
;l Dodecyl mercaptan 4.3 :
Portion 2 .
Methyl methacrylate monomer 27.0
,~ Benzo~l p.eroxide 3
i Portion 3
, .
Methyl methacrylate monomer 293.0 !.
Butyl acrylate monomer 142.0 ~ ~:
2-Hydroxyethyl acrylate monomer 31.0 :
~ Acrylic acid monomer 35.0
.l Isopropanol .42.0
.'~ Ethylene glycol monobutyl ether acetate 137.0
,,
.l Ben~oyl peroxlde 17.0
'~j 25 ~ Total1009!6

Portion 1 is charged into a reaction vessel e~uipped
with a ~tirrer> a heating mantel, and a reflux condenser and
then the constituents are heated to a re~lux te~perature.
' Portion 2 ~s premixed and then ~dded to the re~ction ~essel
? 3o and then the reaction mixture 1~ brought to ~ts re~lux tempera-
ture. Portion 3 is then premixed and 40% of Portion 3 ls
~:., added over a 20-minute period while maintalning the reaction
,;, mixture at its reflux temperature~ The remainin~ 6o~ o~
, 1 ..
, 23 - ~ :
: i . , , ~;
.~ .

~38522
I Portion 3 i6 added continuou~ly over an 80-minute perlod ~I
and then the reaction mlxture is held at lts re~lux
temperature for a~} additional hour and then cooled to room
temperature and filtered.
. 5 The resultlng polymer disperslon haa a solids content ;;
; of about 70% and the polymer has a rel~tlve vlscosity of about
-~ 1.09 measured at 25 in dimethyl formamide and about
0.5% polymer solids and the polymer has an acid number of
about 47 and a carboxy to hydroxyl ratio of 1 to o.58. The ~ :
.
.. 10 polymer has the following composition: methyl methacrylate/
; .~ -
., butyl acrylate/2-hydroxyethyl acrylate/acrylic acid in ~
~`~ weight ratio of about 54/34.2/5.7/6,1 and a uniformity factor
of about 75-85~
., ~ . . .
A coating composition ls then prepared as follows:
Parts By
_ ~eight
:! ~ .
Portion 1
j Polymer solution (prepared above) 200
. ", . . ...
i Portion 2
;j . - ,
Dlethylamlnoethanolamine 14
Portion 3 ~ ~:
Deionized ~ater 318 ~: .
Portion 4 . ~
.
Hexa(methoxymethyl)melamine 60 ~ ~
., , ~-,
3 25 Tot~l 592 ~-

Portion 1 ls charged into a mixing vessel and then :~
Portion 2 is added and blended with Portion 1. Portion 3 is
~ then slowly added with constant agitation. A~ter Portion 3
:-~ ls added, all of Portlon 4 is th~n added ~nd mixed in. The
~0 resulting coating compoæition has a sol~ds of content of
j~ about 33~ and a spray viscosity of abouk 30 seconds using a

;1 No. 2 P~rlin cup.
, I :.
:. _ 21
;1

:
~::
~03~ Z
; A standard spray gun is used to apply the coatlng ;
composition to a steel panel primed with 1.5 mil thick iron
oxlde pigmented alkyd resin prlmer. After the coating is
applied, the panel i8 baked for 15 minute~ at 90C. and then
~or 30 minutes at about 1~0C. to prov~de a coating of about `
2 mils thick that ha~ a good appearanceJ good gloss, excellent ~:
', hardness, and good chip resistance. :
.. ~. ,
EXAMPLE 3 -~
~' ~
A coating composition is prepared by first forming ;~ ;
the following acrylic polymer solution:
,.,
Parts By :
, , Wei~t
i Portion 1
,; .
:. Methyl methacrylate monomer 55.0
i 15 Butyl acrylate monomer 81.0 ~ : :
',Jl 2-Hydroxyethyl acrylate monomer 9.O : ;
,~ Acrylic acid monomer 15-
Isopropanol ~0.0
Ethylene glycol monobutyl ether 75.0
~! 20 Dodecyl mercaptan 1.4
Portion 2
~ Ben~oyl peroxide 3.3 ~:
,~ Methyl methacrylate monomer 30.0 : ;~
, Portion 3 :
Methyl methacrylate monomer 29200
Butyl acrylate monomer 116.
. 2 Hydroxyethyl acrylate monomer 3~.0
Acrylic acid monomer 69.0
,, .
Benzoyl peroxide 13.0
Isopropanol 42.0
Ethylene glycol monobut~l ether 132._
:
` Total 99~7
, .. .
~ -25

~ 1~38522
; Portion 1 1~ charged lnto a re~ction vessel
- equipped wi~ a s~irrer, a heating man~el and a reflux
condenser and then heated to lts reflux temperature. ~ -
Portion 2 1~ premixed and then added to the reaction mixture.
Portion 3 is premixed and 46% of Portion 3 is continuously ~ ~;
~! added over a 20-minute period, and then the remainder of
;~~ Portion 3 is continuously added over a 60 minute period
j whlle malntaining the reaction mixture at lts reflux tempera-
- ture. The reflux o~ the reaction mixture is continued for an
additional 90 minutes. The reaction mixture is then coo:Led to
room temperature and filtered.
.
The resulting polymer dlspersion has a solids content
about 71% and the polymer has a relative viscoslty of 1.0~6
measured at 25C. ln dimethyl ~ormamide at about 0.5~
i 15 polymer solids, and the polymer has an acid n~unber o~ about
93 to 94 and a c~rboxyl to hydroxyl ratio of 1 to 0.31. The
:
polymer has the following composition: methyl methacrylate/
butyl acrylate/hydroxyethyl acrylate/acrylic acid - -
,"~
53.8/28.2/6.0/12.0 and a uniformity ~actor of about 75-85~.

A coatlng compo~ition i8 prepared by blending the
followlng ingredients:
Parts By
Welght
Portlon l
Polymer solut~on prepared above 200
Portion 2
Diethylaminoethanolamine 15
~; Portion 3
-1 Delonized water 31
Portion 4
'~ Hexa(methoxymethyl) melam~ne 60
' Total 593
~.
."~ ,.
. .
- 26 -
, , ~

. .,

.: :: .. :: .' . :' : ' ',, ,, : .

l;


3~95ZZ
Portion 1 ls charged lnto a mixing ~e~sel and , .
then Portion 2 iB added wlth constant agitation and then .
Portion 3 is 810wly added to the reaction m:lxture and after
Portion 3 ha3 been added, Portion 4 i6 added and blended with
; 5 the reactlon mixture. The resul~ing compos:ltion has a 33%
polymer solids content and a spray viscosity o~ 30 seconds
measured in a No. 2 Parlin cup. The compos:ltion is then sprayed :
onto a steel panel prim~d a~ in Example 1 and baked according
i to the procedures described in Example 1. The resulting
~inish i8 about 2 mils thick, has good appearance and is an .
-, acceptable finish for the exterior of automob~le bodies and ~ ~ .
truck bodle~.

EXAMPLE 4 ..

~ A coating compo~ition i~ prepared by first ~orming
! 15 the following acrylic polymer ~olution:
~a.t~ ~y
Wei~ht
Portion 1 .
Methyl methacrylate monomer lR.210 :
~, 20 Butyl acrylat2 monomer 21.050
! 2-Hydroxyethyl acrylate monomer 1.900
. Acrylic acid monomer 1.810
Isopropanol 6.55
Ethylene glycol monobutyl ether 8.73
Lauryl mercaptan 0.310
'~ Portlon 2 .
.i . Benzoyl peroxide 0.716
` Ethylene glycol monobutyl ether 5.880

~ . ~

,,~ .
. '. .
27 _
'


. . . .. : . . . - .

; ~0~2Z Parts By
Wei~ht
Port1on 2 (Continued)
.
, Methylethyl ketone 1.600
5Portlon ~ :
. Methyl methacrylate monomer 26.800 ~:
Butyl acrylate monomer 130030 :.
2-Hydroxyethyl acrylate monomer 2.860 :~
Acryllc acid monomer ~.18 ;
Benzoyl peroxide 10150
Isopropanol 3.8 :~
Ethylene glycol monobutyl ether 12.400
~, Portion 4 .~ -Methyl methacrylate monomer 26.800 i: .
Butyl acrylate monomer 13.030 :
2-Hydroxyethyl acrylate monomer 2.850
I Acrylic acid monomer ~-17
-~ Benzoyl peroxi~e 1.150 . . ~ :
Isopropanol . ~.800
i 20 Ethylene glycol monobutyl ether 12.400
,~ Portion 5
} Methyl methacrylate monomer 10.210 ~ ~
~i Butyl acrylate monomer 4.880 ~ ;
2-Hydroxyethyl acrylate monomer 1.160 -~. :
~' Acrylic acid monomer 1.200 ; -
Benzoyl peroxlde o.474
~ ~.
;~ Isopropanol 1.550
:~ Ethylene glycol monobutyl ether 5.o80
.~ portion 6
Dleth~lethanol~mine 10.500
Demlneralized water . 128.000
:~ ,
. 9

, ;,~ . .
,,'.1
. ,.j .

~, .
~ 8 ~
. ,,. ~


.. . . . " .. , _

`~

Parts By
_~Weii~ht

Portion 7
Demineralized water 209.60
. ~
, 5 Total 566~730

Portion 1 i8 charged into a reaction vessel equipped
with a stirrer, a heating mantel and a ref:Lux condenser and
the ingredients are heated to the reflux temperature.
Portion 2 is premixed and then added to the reaction mixture
` 10 and then Portion 3 is added at a uniform rate over a
,'lf 20 minute period while maintaining the reaction mixture
t at a reflux temperature. Portion 4 is premixed and then
about ~4~ of Portion 1~ is added at a continuous rate to the
~J~ reaction mixture over a 20-minute period. Then the remainder
of Portion 4 is added at a continuous rate over the next 60-
~,' minute period while maintaining the reaction mixture at its
,~ reflux temperature. Portion 5 is premixed and thën added at
.,., : . :- .
l a uni~orm rate over a 100-minute period keéping the réaction
,j mixture at its re~lux temperature and then thé reâction
mixture is held at its reflux temperature for an additional
1/2 hour. Portion 6 is then added to the reaction mixture
¦ and then Portion 7 is added and the mixture is cooled and
~iltered to remove coa~ulum. ~ ;
.. ,~, . . . . . .. .
The resulting polymer dispersion has a po~ymër
~solids content of about 26% by weight and the polymer has a
reiative viscosity of about 1.15 measured at ~5C. in dimethyl
;~ ~ormamide solvent at about 0.5% polymer solids. The po-lymer ~-
has an acid number of about 46 to 47 and a carboxyl to hydroxyi
;' ratio o~ 1 to 0.62. The polymer has the ~oi~owing compositioni
;i~ 3o met~yl methacrylate~ but~l acrylate/2-hydroxyethyl acryiate/
' acrylic acid in a weight ratio of about 54/34j6/6 and a
;~ unlformity factor of about 75-85~.



, .,;~,

.Q3~9S2~
A paint compo~ition is then prepared by
blending together the following lngredients:
Parts By
Weight
Portion
. Mill base (described in Example 1)
:. MONASTRAL Blue mill base (prepared ln ~ample
1) 0.20
MONhSTRAL Violet mill base (prepared in Example ; "~
1) 0.70 . :
. Phthalocyanine green-yellow mill base ::
(prepared in Example 1) 0.45
~ Alumlnum Flake mill baæe (prepared in Example
;~ 1) 11.05
Ii Portion 2
;~ Hexa(methoxymethyl) melamine 20.40 . .
Portion 3 . .
. Acrylic polymer dispersion (prepared above) 272.1~0
Portion 4
Deionized water 18.00
Portlon 5
Butyl acrylate/acrylic acid copolymer ~:
solution (described ln Example 1) 3.30
Anti-cratering solutlon (10~ silicone solution) 3,35 ~ ~.
Deioni~ed water 31.00
$~ Total 367.20
, Portlon 1 i8 chargcd into a mixing vessel and
`; thoroughly blended together and then Portion 2 i~ added and
~ bl~nded and then Portion 3 i~ added and the constituents are
, ,,
thoroughly blended together. Po~tion 4 i9 added and blended
~: with the mixture and then Portion 5 is added and thoroughly
bler~ded with the mixture. me resulting paint composition
has a 28~ ~ollds content and a ~pray visco~ity of 31 seconds
using a No, 2 Zahn Cup.


J ~ ~

,`?
` .


. ., . ~ . ~ . , .

: ~ 1038S~Z ~ ~ ~
The paint is sprayed onto ~ steel panel
. prlmed with 1.5 mil thick lron oxide pigment alkyd resin
~, primer as in Example 1. The coating is baked as in Example 1 . ~
providlng a film about 2 mils thick which has good gloss, : ;
good appearance, good adhesion to the substrate, good chip
-.` resistance, good gasoline reslstance and resistance to .
-i. deterioration by weathering.

EXAMPLE 5 .

~; A coating composition is p-epared by first forming
;l 10 the following acrylic polymer solution~
~ Parts By ~`
I Weight ~ ~
Portion 1 ~ `
;~ ,' `I
., ,, ~ .
Methyl methacrylate monomer 47
Styrene monomer 30
utyl Acrylate monomer ; 112 .
`.. `!~: 2-Hydroxyethyl acrylate monomer 15 : ;~,~ Acrylic acid ~onomer 6 ..
Ethylene glycol monobutyl ether 190
~ 20 Isopropanol 30
`; Dodecyl mercaptan 2
~ Portion 2 .
~ Eth~lene glycol monobutyl ether 30
`,~ Tertiary butyl peracetate solution 9.5 .:
(75~ solution in mlneral spirits) ~ ~
Portion 3 ~.
~:~ :
~.x ~ Methyl methacrylate monomer 117
~ Styrene monomer ~ 174
~ Butyl acrylate monomer 112 ~;
: 2-Hydroxyethyl acrylate monomer 42
.~ Acrylic acid monomer : : 23

., ~1 : .
~ 31 _ i ;
.;J`~ ::
! :~
. , ~ . . ; ~

4~ `
~ `Portion 4
la3ss2~ 4,o ~ ~
Isopropanol
Tertiarybutyl peracetate solution
(described above) 3.9
Total 983.4
Portion 1 is charged into a reaction vessel equipped
; with a stirrer, a heating m~ntel and a refl~ condenser and
,~ heated to its reflux temperature. Portion 2 is then adde~ and
ir the reactlon mixture is held at its reflux temperature ~or 5
... .
minutes. Portions 3 and 4 are premixed and added s~multaneously
in the following order: 85% of portion 3 i6 slowly added over ~ ~ ,
a 25 minute period alon~ with 75~ of portion 4 then the remainder
of portion 3 is added over a 60 minute perlod while the remainder
of portion 4 is added over a 90 minute period. During these
', addltions, ths reactlon mixture is held at its re~lux tempera-
~ ture and after the additions the reaction mixture is re~luxed ~ ;}~ for one hour.
The resulting polymer dispersion has a solids content
~( of 70~, the polymer has a relative viscosity mea~ured a+ 25C.
; ~ 20 in dimethyl forma~ide at 0.5~ polymer solids of about 1.15;
,~ the polymer has an acid number of 33-35 and a carboxyl to
hydroxyl ratio of 1 to 1.5. m e polymer has the following
composition: styrene/methyl methacrylate~butyl acrylate/
2-hydroxyethyl acrylate/acrylic acid - 30.0/24.2/33.1/8.~/4.3
and has a unlformlty factor of about 75-85%. ~ ;
A coating composition is prepared as in Exa~ple 3 ~ -~
. . ~,
except the above prepared polymer solution is used. The ~ ;
` composition is sprayed onto a prlmed steel panel and ba~ed
~ as ln Example 3. m e resulting finish is a~out 2 mils thick,
'~ 30 has a good appearance and is an acceptable finish for the
exterlor of automob1le and truc~ bodies.
- 32 ~




, ~ ,

.; ,~

.", ~ . , . . , . . . ~ ~ . ..



~ Example 6
:: t.. -
A coa,'-;ing composition is prepared by ~lrst ~orming
the followlng polymer solution by a programmed polymerization l,-. i`:
process: l~
Parts by l ~.
-., Welght
~i Portion 1 -~
;~-' Methyl methacrylate monomer 241
.! Butyl methacrylate monomer 571 `` ~`:
'., 10 2-Hydroxy ethyl acrylate monomer 55
.~ Acrylic acid monomer 46 .
Isopropanol 402
Ethylene glycol monobutyl ether 771
Lauryl mercaptan 14 ~ .
l 15 Portion 2
Benzoyl peroxide 7
Methyl methacrylate monomer 254 .
!~ Portion 3
' Methyl methacrylate monomer 1211 ~:
l 20 Butyl acrylat~e monomer 504
" 2-Hydroxy ethyl acrylate monomer 135
Acrylic acid monomer 144
Benzoyl peroxide 72
.¦ Portion 4
25. N~N-diethyl aminoethyl amine 185
Water 310 ~ :

: i....... /~

,', j: ," ~ ` ' ~ :
~ ? ,: .

~:, 33 ~
'.,,

" ~:

~L03~ Z Pwrtishtby
r ;
Portion 5 ~i~
`', Water 1600
Portion 6
~ Water 16~0 ,
',~ Portion 7
~;1 Water 1878 ;
~) Total 10,000

i 10 Portion 1 is premixed and charged into a reaction
vessel equipped with a stirrer, a heating mantel and a reflux
condenser and heated to its re~lux temperature~ Portion 2 is
then added. Portlon 3 is premixed and 30~ added over a 15
minute period while maintaining a reflux temperature9 45% of ;~
Portion 3 is then added over a 50 minute period while main~
~ taining a reflux temperature and the re~ainder of Portion 3
:,: , : ::
is added over the next 80 minutes while maintaining a reflux
.. ,
-! temperature and the reaction mixture is held at its reflux ,
;.,, . ;
; :! temperature for another 30 minutes. Portion 4 is added and -
i' 20 mixed for 10 minute~ then Portion 5 is added over a 10
minute period with mixing. Portions 6 and 7 are then added
., with mixing between each addition. `~ ;

. The resulting polymer dispersion has a ~olids content
~ v~ 32%~ About 40~ of the polymer is dispersed and th0 dispersed
m~ 25 polymer particles have a partlcle size of about o.o2-0.06 microns
and the remainlng 60~ o~ the polymer is dissolved. The polymer
has a rela~ive viscosity of 1.15-1.16 measured as in Example 1,
the polymer has an acid number of 47 and a carboxyl to
`' hydroxyl ratio of 1 to 0.62. The polymer has the following
.~.~ . .. ..

',,', ,

s~ ~ - 34 ~
.,,

~Q~522 `;
- composition: methyl methacryl~te/butyl acrylate/2-hydrox~- 1
ethyl acrylate/acrylic acid _ 54/34/6/6~ and has ~ uniformity
factor at about 75-85
A coating composition i8 prepared as in Example 4
except the above prepared polymer solution :ls used. The
composition is sprayed onto a primed steel panel and baked
as in Example 4. The resulting finish is about 2 mils ~ .
-, thick~ has a ~ood appearance and i8 an acceptable finish
.. for the exterior of automobile and truck bodies. : .
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, ~ :
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'~ - 35
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