Note: Descriptions are shown in the official language in which they were submitted.
1 324224
The present invention relates to an aqueous coating
composition which is useful as a top coat. More
specifically, the invention concerns an aqueous coating
composition comprising as resinous vehicle (a), an aqueous
S resin particles containing composition obtained by the
polymerization of ~ ethylenically unsaturated monomer(s) in
an aqueous medium and in the presence of a larger amount of a
water soluble resin, and (b) a particular water soluble
resin, which is excellent in storage stability and
application characteristics and is capable of resulting a
coating with excellent film properties and especially
improved gloss and smoothness, and hence is specifically
useful as a top coat for automobile bodies and the like.
lS An aqueous coating composition is generally inferior to a
' solvent type composition in durability and water resistance
of the formed coating and since it is unable to get a
~ composition with a higher non-volatile content, application
-~ characteristics are rather poor. Even if an amount of water
insoluble resin powders are compounded with said aqueous
composition with the hope for increasing the non-volatile
content thereof, viscosity of the compounded system is
inevitably increased therewith and hence, a practical coating
composition cannot be obtained.
The lnventors had formerly found that by the selective use
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of a particular water soluble resin which will fulfil the
requirements that ~he water tolerance, expressed in terms o~
water dilution multiplicand of the resin for the solu~ion
incapable of reading out the defined type in the test
wherein 5g of aqueous varnish having a common viscosity
usually employed in the manufacture of a coating composition
; are correctly weighed in a 100 ml beaker, diluted with an
increasing amount of deionized water, and a No. 1 type (26
point type) i9 read through the said beaker, is 4 or more,
and the surface tension calculated for a 1~ w/w aqueous
solution is 51 dyne/cm or less, it is possible to formulate
an aqueous coating composition comprising said water soluble
resin and water insoluble resin powders uniformly dispersed
therein having a wider solid weight ratio of 98:2 to 45:55,
without the fear of undesired increase in viscosity of the
system, and it is thus able to increase the resinous content
of a coating composition and have the composition with
excellent application characteristics, as well as the
improved dispersion stability and film properties. On the
basis of these findings, a patent application was filed,
which is now publicly opened as Japanese Patent Application
Kokai No. 15567/83. Though the resinous powders used in
that invention were prepared by pulverizing a solidified
resin and shieving the same, various technique have been
developed to obtain the better quality powders to be
compounded with a water soluble resin since then. In facts,
certain improvements have been attained with these products
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~ 1 324224
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in respect of application characteristics and storage
stability of the coating composition and film properties
including gloss and smoothness, of the formed coating.
However, in most of the heretofore proposed processes, the
water insoluble resin powders were advantageously prepared by
an emulsion polymerization of ~ ethylenically unsaturated
- monomer(s) in an aqueous medium containing a surfactant or
emulsifier and in the presence of a polymerization initiator,
and therefore, it was unavoidable that the surfactant used
was always remained on the surfaces of the formed particles,
giving undesired effect on the film properties and especially
on water resistance of the film and that when a water soluble
radical initiator was selected, said initiator was likewise
, remained at the end portions of the polymer chain, giving
$ 15 undesired effect on film properties, too. Thus, an
I additional improvement has been longed for.
.; .
J Moreover, with an increasing demand for high-grade
articles, an aqueous type, top-coat composition capable of
resulting a coating with far improved gloss and smoothness
has been required, especially in an automobile and an
electric appliance industries.
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1 324224
According to the invention, there i8 provided an aqueous
coating composition comprising as resinous vehicle,
(1) an aqueous, resin particles containing composition
obtained by polymerizing at least one a,~-ethylenically
S unsaturated monomer in an aqueous medium and in the presenceof a water soluble resin (A) with the help of an organic
initiator, in which the solid weight ratio ôf said water
soluble resin to said monomer i8 35-95:65-5, and
. (2) a water soluble resin (B) having a water tolerance of 4
or more and a surface tension for a 1% w/w aqueous resin
. solution of 51 dyne/cm or less,
`~. the solid weight ratio of said resin particles to the total
of said water soluble resins (A) and (B) being 70-1:30-99.
, .
The present aqueous, resin particles containing composition
should be prepared by the polymerization of at least one a,~-
ethylenically unsaturated monomer in an aqueous medium and in
the presence of a water soluble resin (A), with the help of
an organic initiator. The solid weight ratio of said water
~: 20 soluble resin to said monomer should be in a range of 35:65
~: to 95:5.
As the water soluble resin (A), any of the members
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1 324224
customar~ly used in a coatlng composition area may be
satisfactorily used, including polyester resin, alkyd resin,
- acryl resin, acryl modified polyester resin, acryl modified
alkyd resin and the like. Since they have, in general, an
amount of acidic groups as carboxyl group, they are
neutralized with a basic material so that solubility is
given to them.
However, in the present invention, the water soluble resins
(A~, as well as the water soluble resins (B) hereinafter
mentioned, do not absolutely necessary be of fully soluble
type and they may be of partly soluble and partly
dispersible type. Therefore, the term "water soluble resin"
as used herein denotes either of water soluble resin and
water reducible or dilutable resin.
As already mentioned, the present resin particles are
prepared by the polymerization of d,~-ethylenically
unsaturated monomer(s) in an aqueous medium and in the
presence of a comparatively large amount of said water
soluble resin ~A) in place of a surfactant or emulsifier as
used in a conventional emulsion polymerization.
At this time, the solid weight ratio of said water soluble
resin (A) to said monomer is determined in a range of 35:65
to 95:5. This is because, if the amount of said water
soluble resin (A) is less than 35 wt% of the total of said
resin and monomers, it is very hard to obtain a stable
aqueous composition containing the resin particles and if
the amount of said monomer is less than 5 wt~, it is unable
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to carry out an emulsion polymerization smoothly and
effectively.
As the d,~-ethylenically unsaturated monomer, any of the
members cu~tomarily u~ed in the preparation o~ acryl resin9
may be satisfaetorily used, each in singularily or
combination of two or more. Examples of these monomers are
as follows.
1) carboxyl containing monomer:
for example, aerylic acid, methacrylie acid, erotonie aeid,
`~ 10 itaconic acid, maleic acid, fumaric aeid and the like,
. , 2) hydroxyl containing monomer:
for example, 2-hydroxyethyl acrylate, hydroxypropyl
acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl
methacrylate, hydroxybutyl acrylate, hydroxybutyl
15 methacrylate, allyl alcohol, methallyl alcohol and the like,
3) nitrogen containin~ alkyl ~meth) acrylates:
for example, dimethyl aminoethyl acrylate, dimethyl
aminoethyl methacrylate and the like,
4) polymerizable amides:
20 Eor example, acrylamide, methacrylamide and the like,
5) polymerizable nitriles: -
for example, acrylonitrile, methacrylonitrile and the like,
~ 6) alkyl acrylates and alkyl methacrylates:
3 for example, methyl acrylate, methyl methacrylate, ethyl
~ 25 acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl
3~ methacrylate, 2-ethyl hexyl acrylate and tha like,
3 - 7) polymerizable aromatic compounds:
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for example, ~tyrene, d-methyl styrene, vinyl toluene,
t-butyl styrene and the like,
8) d-olefins:
for example, ethylene, propylene and the like,
9) vinyl compounds:
for example, vinyl acetate, vinyl propionate and the like,
10) diene compounds:
for example, butadiene, isoprene and the like.
As a part of said ~,~-ethylenically unsaturated monomers,
one may use a crosslinking monomer having 2 or more
radically polymerizable, ethylenic bonds per molecule.
Examples of such crosslinking monomers are polymerizable
unsaturated monocarboxylic acid esters of polyhydric
alcohols, polymerizable unsaturated alcohol esters of
polycarboxylic acids, and aromatic compounds substituted
with 2 or more vinyl groups and the like, including ethylene
glycol diacrylate, ethylene glycol dimethacrylate,
triethylene glycol dimethacrylate, tetraethylene glycol
dimethacrylate, 1,3-butylene glycol dimethacrylate,
trimethylol propane triacrylate, trimethylol propane
trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol
diacrylate, 1,6-hexanediol diacrylate, pentaerythritol
diacrylate, pentaerythritol triacrylate, pentaerythritol
tetraacrylate, pentaerythritol dimethacrylate,
pentaerythritol trimethacrylate, pentaerythritol
tetramethacrylate, glycerol dimethacrylate, glycerol
diacrylate, glycerol allyloxy dimethacrylate,
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1 324224
l,l,l-trishydroxymethylethane diacrylate,
l,l,l-trishydroxymethylethane triacrylate,
l,l,l-trishydroxymethylethane dimethacrylate.
l,l,l-trishydroxymethylethane trimethacrylate,
5 l,l,l-trishydroxymethylpropane diacrylate,
l,l,l-trishydroxymethyl propane triacrylate,
l,l,l-trishydroxymethyl propane dimethacrylate,
l,l,l-trishydroxymethyl propane trimethacrylate,
triallyl cyanurate, triallyl isocyanurate, triallyl
10 trimellitate, diallyl terephthalate, diallyl phthalate,
divinyl benæene and the like. By using such a crosslinking
monomer, particles of crosslinked copolymer can be obtained.
The abovesaid monomers are polymerized in an aqueous medium
and in the presence of a water soluble resin (A) and at that
:1 15 time, an organic initiator may advantageously be-used.
s As the oryanic initiator, use can be made of such members as
diacyl peroxides (e.g. acetyl peroxide, lauroyl peroxide,
benzoyl peroxide and the like), hydroperoxides (e.g. cumene
hydroperoxide and the like), alkyl peroxides (e.g. di-t-
20 butyl peroxide, t-butyl peroxy 2-ethyl hexanoate, t-butyl
! perpiperate, t-butyl perbenzoate and the like), azo
compounds (e.g. 2,2-azobis isobutyronitrile and the like),
disulfides (e.g. tetramethyl thiuram disulfide and the
like), and sulfinic acids (e.g. p-toluene sulfinic acid and
25 the like).
Among them, particular preference is givent to a water
insoluble organic initiator as azobis isobutyronitrile,
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1 324224
benzoyl peroxide, di-t-butyl-peroxide, cumene hydroperoxide
and the like.
Usually, water is used as a reaction medium, but in a more
preferable embodiment of the invention, a mixture of water
and an organic solvent is selectively used. The inventors
have found that when an aqueous composition (l) is prepared
by a method wherein ~,a-ethylenically unsaturated monomers
are polymerized in a mixture of water and an organic solvent
and in the presence of a large quantity of water soluble
resin (A) and a water insoluble organic initiator, and thus
obtained composition (l) is compounded with a water soluble
resin (B) hereinafter mentioned, a particularly useful
aqueous coating composition can be obtained, which is less
foaming, hardly give pinholes, less sagginy and capable of
resulting a coating with higher gloss and far improved
~moothness. Therefore, in a preferred embodiment of the
invention, the aqueous composition (l) is prepared in a
reaction medium comprising water and an appropriate amount
of a common organic solvent customarily used in the
preparation of solvent type coating composition.
Thus, in the present invention, it is essential that an
aqueous composition containing resin particles be prepared
by the polymerization of at least one d,R-ethylenically
unsaturated monomer in an aqueous medium optionally blended
- 25 with an organic solvent and in the presence of a large
quantity of a water soluble resin (A) and in the presence of
an organic initiator, preferably a water insoluble organic
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1 324224
initiator. In this aqueous composition, the water soluble
resin (A) is physically adsorped on or bound with the resin
particles and the particles are stably dispersed in the
medium by the high molecular effect of the water soluble
resin (A) used.
Since the aqueous composition does not include any of the
undesired water-soluble by-products, ionic substances and
other impurities, and the water soluble resin per se is
useful as a binder resin, there are no undesired effects on
the properties of the formed coating mainly due to the
emulsifier or surfactant usually presented in a conventional
coating composition.
he inventors have also found that when ~,~-ethylenically
unsaturated monomer(s) is (are) used in the form of mixture
with at least one hydrophobic solvent or with at least one
hydrophobic solvent and at least one hydrophobic resin,
hydrophobic solvent and/or hydrophobic resin encapsulated
resin particles can be obtained and far improved coating
composition can be formulated with thus obtained aqueous
composition and an aqueous resin (B) hereinafter defined.
At this time, outstanding improvements are realized in
respect of application characteristics of the coating
composition and gloss and smoothness of the formed coating.
Therefore, in a particularly preferred embodiment of the
present invention, use is made of an aqueous composition
containiny solvent encapsulated resin particles obtained by
the polymerization of a mixture of at least one ~
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1 324224
ethylenically unsaturated monomer and at least one
hydrophobic solvent in an aqueous medium and in the presence
of a water soluble resin (A) and an organic initiator~ or an
aqueous composition containing hydrophobic resin
encapsulated resin particles obtained by the polymerization
of a mixture of at least one d,~-ethylenically unsaturated
monomer and a hydrophobic resin or both hydrophobic resin
and hydrophobic organic solvent, in an aqueous medium and in
the presence of a water soluble resin ~A) and an organic
initiator.
In the abovesaid embodiment, as the hydrophobic solvent, any
of the organic solvents having solubility in 20C water of
. lO weight % or less may be satisfactorily used, providing
~` having an optimum evaporation rate and boiling point seeing
from the view point of application characteristics of the
coating composition. Examples of such oryanic solvents are
heptane, hexane, n-octane, iso-octane, decane, ligroin,
kerosine, toluene, xylene, naphthalene, isobutanol, n-
butanol, n-hexanol, methyl-n-butyl ketone, butyl acetate,
Solvesso 150 (trademark, Esso Petroleum~ and other aliphatic
or aromatic hydrocarbons, petroleum cuts, alcohols, esters,
ketones and the like.
As already stated, the reaction medium may be water alone or
a mixture of water and an organic solvent. The latter
solvent may be of the same or different type from the
abovesaid hydrophobic organic solvent to be encapsulated in
the resin particles, and it may be of water miscible or
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immiscible natUre. ~y th~ inclusion of said solvent in a
reaction medium, it is possible to obtain an aqueous coating
composition which is low in foaming, hardly form pinholes
and is excellent in gloss, smoothness and sag resistance.
When a mixture of hydrophobic solvent and polymerizable
monomer(s) is used, the mixing rate of said solvent and
monomer(s) may be varied in a wider range.
It is, however, generally determined in 80:20 to 3:Y7,
preferably 60:40 to 10:90, on weight basis. This is because
if the solvent to be encapsulated is more than 80 wt ~,
there is a tendency that stability of the coating
composition be lowered and if the solvent is less than 3~,
there is no slgnificant improvement in smoothness of the
coating.
As already stated, inclusion of a hydrophobic solvent in the
resin particles is effective for the control of viscosity of
the coating composition at the application and the baking
stayes, and hence considerable improvements in application
characteristics and coating appearance and especially
smoothness can be attained therewith.
ethylenically unsaturated monomers may also be used in
the form of mixture with a hydrophobic resin or a
combination of hydrophobic resin and hydrophobic solvent, to
obtain the hydrophobic resin encapsulated resin particles.
In this particular embodiment, any of the known hydrophobic
resins may be satisfactorily used provided that they are
insoluble in water. Examples of such resins are an alkyd
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1 324224
resin, a polyester resin, an acryl resin, an acryl modified
alkyd resin, an acryl modi~ied polyester resin, an epoxy
resin, an aminoplast resin, a polyether resin, a petroleum
resin, a silicone resin, a polyurethane resin, a fluorine
plastic, a cellulosic resin and the like.
The hydrophobic solvents are the same members as stated
hereinbefore.
The mixing ratio of said hydrophobic resin and polymerizable
monomer(s~ may be varied in a considerable range. It is,
however, determined in 1-7~:99-30, preferably 5-50:95-50, on
weight basis. This is because if the amount of said
hydrophobic resin is too large, there is a tendency that
stability of the resin particles in an aqueous composition
be lowered and if the amount of the hydrophobic resin is too
small, the desired effect of improvement in smoothness of
coating cannot be attained therewith.
The inventors have now found that inclusion of hydrophobic
resin or a combination of hydrophobic resin and hydrophobic
solvent in resin particles is very effective for the
improvements in coating appearance and especially smoothness
and gloss, and in application characteristics and sag
resistance of the coating composition.
That is, the presence of hydrophobic resin in the resin
~- particles may contribute to the formation of coating wherein
comparatively small size of aggregates of resin particles
, are stably and uniformly distributed in a water soluble
resin phase, for which a highly glossy coating can be
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1 324224
obtained. ~oth of the hydrophobic resin and hydrophobic
solvent are effectivè for the improvement in smoothness of
the coating. When a phdrophobic melamine resin i5 us-ed,
yield value of the coating composition is markedly increased
and hence, a sag resistance is yreatly improved. The
presence of a hydrophobic solvent in the resin particles i9
effective in the control of viscosity of coating composition
at the coating and baking stayes, which may attribute to the
~ '
marked improvement in application characteristics such as
pinholing and smoothness of coating.
In the present invention, thus obtained aqueous composition
` containing resin particles is compounded with a particular
water soluble resin ~B) having a water tolerance of 4 or
1 more and a surface tension for 1~ w/w aqueous varnish of 51
J~ 15 dyne/cm or less, which is minutely stated in Japanese Patent
Application Kokai No. 15567/83.
That is, the water soluble resin (B) must fulfil the
~ requirements:
¦ (1) that the water tolerance, expressed in terms of the
20 water dilution multiplicand of the water soluble resin for
the solution incapable of reading out the defined type in
the test wherein 59 of aqueous varnish having a common
viscosity usually employed In the manufacture of a coating
composition are correctly weighed in a 100 ml beaker,
diluted with an increasing amount of deionized water, and a
No. 1 type (26 point type) is read through the said beaker,
is 4 or more, and
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(2) that the Sur~ace tension o~ the solution obtained by
dissolving the abovesaid aqueous varnish with deionized
water to 1 wt% solid content, is 51 dyne/cm or less.
Any of the known water soluble resins customarily used in a
water soluble type coating composition may be satisfactorily
used providing fulfilliny the requirements stated
hereinabove, and examples of such resins are an alkyd resin,
a polyester resin, maleic oil, maleic polyalkadiene, and
epoxy resin, an acrylic resin, a urethane resin, an
aminoplast resin and the like.
However, in the present invention, the solid wei~ht ratio of
the abovementioned resin particles to the total of said
water soluble resins (A) and (~) should be in a range of
70:30 to 1:99, preferabl~ 60:40 to 1:99.
This is because, if the amount of water soluble resin is too
low, it will cause deterioration of the dispersion stability
of the resln powders and will damage the leveling properties
of the coated film and if the amount of water soluble resin
is too high, it will cause an excessive increase in the
viscosity of the composition and give rise to a decrease in
water resistance of the coated film.
However, in the abovementioned compounding ratio, there is
no undesired increase in the viscosity of the composition.
Therefore, in the present invention, it is possible to
increase the solid content of an aqueous coating composition
and obtain the product which is excellent in application
characteristics and storage stability and capable of
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1 324224
resultiny the coating with excellent ~ilm properties, gloss
and smoothness.
The reasons why the present coating composition can give a
coatiny which is far superior to the heretofore proposed
' 5 a~ueous coating compositions in respect of glos9 and
smoothness have not been fully understood at the moment, but
. the followiny miyht have a close connection therewith.
That is, since a particular water soluble resin (B) is
selected and compounded with the aforesaid resin particles,
' 10 the particles are floated on the surface layer of the water
soluble resin varnish and a uniform coating is easily
obtained therefrom.
The present coating composition is, therefore, particularly
useful as a top coat in an automobile or other industries
where a higher level of gloss, e.g. 80 or more of 20 gloss,
or smoothness of the coating is required.
The present coating composition may be used as a clear
coating composition as desired, and however, in most
applications, it is used as a color lacquer. In that case,
coloring matter, crosslinking agent and other additives,
3 including antisagging agent, antiflooding agent,
q anticratering agent, surface conditioner, antioxidant, light
stabilizer, UV absorber, antisettle agent and the like, may
!3 be added thereto.
The coating composition can be applied, as it is or after
being diluted with water, in a conventional way, e.g.
spraying, dipping, brushing or the like, and dried or baked
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1 324224
at an elevated temperature to yive the coating with
excellent properties as hereinbe~ore stated.
The invention shall be now more fully explained in the
following Examples. Unless otherwise being stated, all
parts and % are by weight.
Synthetic Example 1
Preparation of water soluble resin varnish-l
Into a 1 liter flask fitted with a stirrer, a
thermoregulator and a condenser, were placed 76 parts of
ethyleneglycol monobutyl ether, added with 61 parts of a
monomer mixture comprising 45 parts of styrene, 63 parts of
methyl methacrylate, 48 parts of 2-hydroxyethyl
methacrylate, 117 parts of n-butyl acrylate, 27 parts of
methacryl acid, 3 parts of lauryl mercaptane, and 3 parts of
,
,- 15 azobisiisobutyronitrile and the combined mixture was heated
under stirring to 120C. Thereafter, the remaining 245
parts of the abovesaid monomer mixture were dropwise added
in 3 hours and then the mixture was stirred for 1 hour.
Next, 28 parts of dimethyl ethanolamine and 200 parts of
deionized water were added to obtain an agueous acrylic
resin varnish having a non-volatile content of 50%. Number
average molecular weight of the contained resin was 6000.
Synthetic Example 2
Preparation of water soluble resin varnish-2
Into a 2 liter glass reactor fitted with a stirrer, a
thermoregulator, and a decanter, were placed 69 parts of
trimsthylol propane, 297 parts of neopentyl glycol, 91 parts
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1 324224
f l~.~drogenated bisphenol A, 201 parts of tetrahydrophthalic
acid, 155 parts of trimellitic anh~dride, and 10 parts of
xylene and the mixture temperature was raised under stirring
condition. The reaction was continued, while maintaining
the temperature at 180 to 210C and removing the formed
water from the reaction mixture, for 5 hours to obtain a
polyester resin having an acid value of 55, a hydroxyl value
of 100 and a nulnber average molecular weight of 1500. Then,
183 parts of ethyleneglycol monobutyl ether and 82 parts of
dimethyl ethanol amine were added and the combined mixture
. was diluted with 851 parts of deionized water to obtain an
aqueous varni~h having a non-volatile content of 45~.
Synthetic Example 3
Preparation of resin particles containiny composition-l
Into a 1 liter reaction vessel fitted with a stirrer, a
thermoregulator and a condenser, were placed 320 parts of
the water soluble resin varnish-l obtained in Synthetic
Example 1, 3U0 parts of deionized water and 20 parts of
butyl diglycol and the mixture was heated, under stirring,
to 85 C. To this, a monomer solution of 40 parts of
styrene, 40 parts of methyl methacrylate, 60 parts of 2-
ethyl hexyl acrylate, 20 parts of 2-hydroxyethyl
methacrylate, and 4.0 parts of t-butyl peroxy 2-ethyl
hexanate was dropwise added in 2 hours and thereafter, the
realction was continued, under stirring, for additional 2
hours to obtain an aqueous composition containing resin
particles whose non-volatile content was 40.0%.
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1 324224
Synthetic Example 4
nto the similar reaction vessel as used in Synthetic
Example 3, were placed 356 parts of the water soluble resin
varnish-2 obtained in Synthetic Example 2, 264 parts of
` 5 deionized water and 20 parts of butyl diylycol and themixture was heated, under stirring, to 85C. Thereafter,
the same monomer solution as used in Synthetic Example 3
`~ were added and reacted as in Synthetic Example 3 to obtain
`~ an aqueous composition containing resin particles, whose
'? 10 non-volatile content was 4~.1%.
~ . Synthetic Example 5
7 Preparation of resin particles containing composition-3
Into the similar reaction vessel as used in Synthetic
~? Example 3, were placed 576 parts of the water soluble resin
15 varnish-l obtained in Synthetic Example 1 and 192 parts of
. deionized water and the temperature was raised, under
stirring, to 85-C. Next, a monomer solution of 3 parts of
styrene, 8 parts of methyl methacrylate, 14 parts of 2-ethyl
hexyl acrylate, 2 parts of 2-hydroxyethyl methacrylate and
20 0.4 part of azobisisobutyronitrile was dropwise added in 2
? hours and the combined mixture was reacted, under stirring,
: for 2 hours, to obtain an aqueous composition containing
resin particles, whose non-volatile content was 40.0~.
Synthetic Example 6
i 25 Preparation of resin particles containing composition-4
Followiny the procedures of Synthetic Example 3, 256 parts
of the water soluble resin varnish-l, 322 parts of deionized
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1 324224
water and 30 parts of butyl diglycol were placed in a
reactor, the mixture was, under stirring, heated to 85C, a
. monomer solution consisting o~ 48 parts of styrene, 48 parts
i of methyl methacrylate, 80 parts o 2-ethyl hexyl acrylate,
16 parts of 2-hydroxyethyl methacrylate and 2 parts of
azobisisobutyronitrile was dropwise added in 2 hours and the
combined mixture was reacted, under stirring, for 2 hours,
to obtain an aqueous composition containing resin particles.
Synthetic Example 7
Preparation of resin particles containing composition-5
The same procedures as stated in Synthetic Example 3 were
repeated excepting substituting the following for the
monomer solution of Synthetic Example 3.
styrene 40 parts
, 15 methyl methacrylate 40
1 2-ethyl hexyl acrylate 60
2-hydroxyethyl methacrylate 15
ethyleneglycol dimethacrylate 5
azobisisobutyronitrile 2
An aqueous composition containing resin particles and having
a non-volatile content of 40.1% was obtained.
Synthetic Example 8
Preparation of resin particles containing composition-6
(comparative composition)
Following the procedures of Synthetic Example 3, 128 parts
of the water soluble resin varnish-l, 400 parts of deionized
water and 16 parts of butyl diglycol were placed in a
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` 1 324224
; reactor, the mixture was heated, under stirring, to 85C, a
monomer solution consiqting of 64 parts of styrene, 64 parts
, .
of methyl methacrylate, 100 parts of 2-ethyl hexyl acrylate,
~8 parts of 2-hydroxyethyl methacrylate and 3 parts of
azobisisobutyronitrile was dropwise added in 2 hours and the
¦ combined mixture was reacted, under stirring, for 2 hours,
to obtain an aqueous composition containing resin particles,
whose non-volatile content was 40~.
(Outside of the invention, because the weight ratio of water
10 soluble resin (solid) to monomers is 20:80.)
Synthetic Example 9
' Preparation of comparative resin particles-l
Into a 2 liter glass made reaction vessel fitted with a
~ stirrer, a thermoregulator, and a condenser, were placed
;~ 15 1100 parts of deionized water, which was then heated to
80C. To this, an aqueous solution of 6 parts of ammonium
persulfate in 100 parts of deionized water and 5 parts of a
monomer solution of 210 parts of methyl methacrylate, 75
parts of 2-ethyl hexyl acrylate and 15 partæ of n-dodecyl
20 mercaptane were dropwise added, under stirring, and
thereafter, stirring was continued for 5 minutes. Then, the
~ remaining parts, i.e. 259 parts~ of the monomer solution
7 were dropwise added under stirring, and after stirring for
15 minutes, an aqueous solution of 1 part of ammonium
25 persulfate in 10 parts of deionized water was added and the
' reaction was continued for 1 hour to obtain a seed emulsion
. having a non-volatile content of 20~.
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1 324224
Into the simllar reaction vessel as used in the preparation
of said se~d emulsion, were plac~d 300 parts of deionized
water and 25 parts of said seed emulsion, and the mixture
was heated to 80C. To this, an aqueous solution of 0.1
part of ammonium persulfate in 20 parts of deionized water
was added, under gtirring, and then a pre-emulsion of 360
: parts of methyl methacrylate, lOS parts of 2-ethyl hexyl
acrylate, 35 parts of 2-hydroxyethyl acrylate, 5 parts of n-
dodecyl mercaptane, 200 parts of deionized water, 0.4 part
of sodium dodecyl benzene sulfonate and 0.8 part of ammonium
persulfate was dropwise added in 2 hours. After completion
of said addition, the mixture was stirred for 30 minutes,
added with an aqueous solution of 0.2 part of ammonium
persulfate in 20 parts of deionized water and further
stirred for l hour. Thus obtained emulsion had a non-
3 volatile content of 48.5%, and the resin particles separated
from the emulsion had an average diameter (measured by
electron microscope) of 0.7~. The maximum grain diameter
was 1.4~ and number average molecular weight of the resin
was ~800.
Synthetic Example lO
Preparation of comparative resin particles-2
Into the similar reaction vessel as used in Synthetic
Example 9, were placed 700 parts of deionized water and 10
parts of sodium dodecyl benzene sulfonate and the
temperature was raised to 80C. To this, under stirring,
4.5 parts of ammonium persulfate were added and then a
- 22 -
~. .
1 324224
monomer mixture oE 36~ parts of methyl methacrylate, 105
parts of ethyl hexyl acrylate, 35 part~ o~ hydroxyethyl
acrylate and 1~ parts of n-dodecyl mercaptane was dropwise
added in 2 hours. After elapsiny 15 minutes from the
completion of said addition, an aqueous solution of 0.5 part
of ammonium persul~ate in 50 parts o~ deionized water was
added and the reaction was further continued, under
stirring, for 1 hour. Thus obtained emulsion had a non-
volatile content of 40% and the average grain diameter of
the resin particles separated from the said emulsion was
0.19 ~, and number average molecular weight of the resin was
~200.
Synthetic Example 11
Preparation of comparative resin particles-3
Into the similar reaction vessel as used in Synthetic
xample 9, were placed 900 parts of deionized water, 1.5
parts of Metrose 60 SH-50 ~methyl cellulose, trade mark,
Shinetsu Kagaku Co.), 216 parts of methyl methacrylate, 63
parts of 2-ethyl hexyl acrylate, 21 parts of 2-hydroxyethyl
acrylate, 6 parts of n-dodecyl mercaptane, and 6 parts of
azobisisobutyronitrile, and the mixture was reacted, under
stirring (rotation speed 250 rpm), at 65C for 7 hours.
Thus obtained suspension was filtered through 20U mesh wire
net to obtain pearl particles having 20 to 600~ diameters,
which was then pulverized in a ball mill for 24 hours to
obtain resin microparticles having an average diameter of
18 and the maximum grain diameter of 45~. Number average
,
- 23 -
.
' 1 324224
molecular weight of the resin was 76~0.
Example 1
nto a 5~ cc stainless steel beaker, were placed lO.part~
of the water soluble resin varnish 3 shown in the following
; 5 Table 1, 1160 parts of the re~in particles containing
composition-l obtained in Synthetic Example 3, and 15 parts
of hexamethoxymethylol melamine and the mixture was stirred
well to obtain a clear coating composition.
This composition was flow-coated on a glass plate and heat-
~` 10 treated at 120~C for 20 minutes to obtain a clear coating,, which had a smooth surface and showed no change even after'~ dipping in a top water for 24 hours. The abovesaid
composition was diluted with water to a Ford Cup #4
viscosity of 30 seconds and then spray-coated on a test
15 plate. The maximum film thickness showing no sayging in
this test was 43~.
Comparative Example 1
A comparative clear coating composition was prepared as in
xample 1, usiny 100 parts of the water soluble resin
20 varnish 3 and 15 parts of hexamethoxymethylol melamine, and
diluted with water and spray-coated. The maximum film
thickness showing no sagging with this coating composition
~ was less than 15 ~.
g The characteristics of the water soluble resins ~B) used in
this and subsequent Examples and Comparative Examples are
shown below.
,;, .
. - 24 -
~, ~
1 324224
~,, s
. 0 3
~\ O OO .C 0 ~ 3
,~ O ~O
o a~ ~ ~u~
5; ~ 00 ~1 ~ 3 Cl~
x~a o
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a c
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:: O C ~ ~ ~ O
Q~ ` 1~0 Ll o
C; ~ dP Inu~ O J~
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C O 1~ 0
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~ ~ 0 ~ ~
J ~ O O O o o I c a) c
N dP O O O O ~ ~ O N O
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c ~ 0
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D~ ~ ~ a~ 0 ~ ~
s ~a~ a) ~1 s
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~-1 ~ 3 ~ ~ S
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a ~ ~ , ~a~ ~ S O O ~: 0 rl ~a
0 a) ~ 0 z~ 0 E3 3
Ll C C ~ S 3 ~ O
:1~D ~ C ~ :~ 3 ~D
0 ~ ~ )-I C --I . J- t4
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` t) C ~ 1 0
).1 ~ V 0 30 a) ~1
a)a) O u~ s c ~:
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: C 0C ~ O S~ ~ 0 J C
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O 0 ~0 ~1 ~ ~ 10a ~3
J~ ~ 0
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0 ~ O O . f~
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_I ~ O ~ U~ Q~
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t - c 0
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~ ~ 0 ~ ~ 0a~ .~
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0 -- ~ s~ ~ 0~ ~Q
h C r~ S ~0 0 :~
0 ~ ~ a~
~ ~ ~ C ~0 S
3 ~ ~ 0 3(a ~C~
.
1 324224
.: Examples 2 to 9
(Preparation of pigment paste)
Into a 1.5 liter stainless steel vessel with a closed~cover,
were placed 36 parts of the water soluble resin varnish 3,
5 320 parts of Rutile type titanium dioxide and 60 part-q of
deionized water and the mixture was, after being
predispersed in a stirrer with 500 cc of glass beads,
dispersed well in a paint conditioner for 2 hours to obtain
a pigment paste-l.
10 ~nother pigment paste-2 was prepared in a same way, by
substituting the water soluble resin varnish-4 for the
abovesaid varnish-3.
(Preparation of coating composition)
Into a stainless steel vessel, the materials shown in the
~- 15 following Table 2 were placed in and the mixture was stirred
well in a stirrer at a room temperature to obtain the
. respective coating composition of Examples 2 to 9.
';
s 25
.,
; - 26 -
:
1 324224
:.
r ~ ~ o
, ~ ~ ~ ~ ,l ~ ~ ,
.,
U~ U~
:~
,
~` 'C
CO 0
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, ~ ~
U~
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U~
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n ,, u~ u~
' O ~1
~-I C) . . .
~`
Q)
,~In
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., ~P ~r
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o m
, In--
. ~ ~ ~ ~ U~ 00 ~~ ~ U~
a~ u~
V~q _~
' 3 L
~ ~1
s R. ~
~: ~ ~ ~ ~ ~ ~ ~ ~ ~
cn _I ~ ~ ~ ~ ~ ~
T , R,
a
~i
~1
.''
~,
I 324224
COmpAratiVe ~xamples 2 to 8
; Using the same procedures as stated in Examples 2 to 9, but
substitutiny the following materials for those of Examples 2
to 9, comparative coating compositions were prepared.
~,
~ ' .
,~ .
..
.~, , .
-`, 15
~
:~ 20
.
\
l 25
j,
,i
- 28 -
,
1 324224
~ o u~
~ .
, o o
` r~
o~ o o aJ
U cr~
o
C ~ U~
~~r/ ~ U~
a,c
C:~ U
.,, ~ o
U~C ~ U~
8 ~ ~
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~` C
C I ~î
r~ ~
Q~
~n
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1 J-
.~
o ~ ~ ~ o
U
~,
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:~ ~n m o
C
, U'~ o o o o
C
~ _I
.
a
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~1~1
OX
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'
'
'
~ ` 1 324224
ach of tl~e coating compositions o~ Examples 2 to 9 and
Comparative Examples 2 to 8 was diluted with deionized water
to a Ford Cup #4 ViSc09ity of 30 seconds and the diluted
composition was spray-coated on a steel plate. After
: 5 setting for 5 minuteg, the coating was baked at 150C for 15
minutes to obtain a crosslinked coating.
~ The maximum film thickness showing no pinholes and the
i maximum film thickness showiny no sagging were determined
for the respective composition, and gloss value and
smoothness of thus obtained coating were evaluated.
Evaluation standards are as follows: -
f Application characteristics:
,. . Mark film thickness showing film thickness showing
`f no pinholes (Jlm) no sagging (l1m)
3 15 ~ more than 50 more than 50
more than 40 to 50 more than 40 to 50
more than 30 to 40 more than 30 to 40
X 30 or less 30 or less
gloss:
Mark 60 gloss 20 gloss
~ more than 93 more than 85
O more than 90 to 93 more than 75 to 85
A more than 80 to 90 more than 65 to 75
80 or less 65 or less
25 Smoothness: -
excellent good no good
- 30 -
~ ' 1324224
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C
J.
~ i ~ ~ ~ O O ~ ~ ~
o~ 8
n (~ ) x O I x (~) x x
~ a~
i~
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- in
~ in
O ~ o I o -o
~ rn
~ 0
o
~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ 0 0 1 ~ 0 ~ x
~ ~ , i
.~
n
1 ~ . O n
~ ~ ~ O O I ~ O ~ X
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1 ~ r.~ r~ D ~ i
N r,~ ~r i;n ~ r~ a~
a~ x
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rrJ
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;
1 324224
Synthetic Example 12
Preuaration of resin particles containing composition-7
Into a 1 liter reaction vessel fitted with a stirrer,,a
thermoreyulator and a condenser, were placed 320 parts of
the water soluble resin varnish-l obtained in Synthetic
Example 1, 300 parts of deionized water and 20 parts of
butyl diglycol and the mixture was heated under Stirring to
85C. To this, a monomer solution consisting of 50 parts of
styrene, 50 parts of methyl methacrylate, 40 parts of 2-
ethyl hexyl acrylate, 20 parts of 2-hydroxyethyl
methacrylate, 2 parts of azobisisobutyronitrile and lO0
parts of xylene was dropwise added in 2 hours, and the
` mixture was stirred Por additional 2 hours to obtain a
: composition containing resin particles and having a non-
... .
`~ 15 volatile content of 35.53.
Synthetic Example 13
Preparation of resin particles containing composition-8
Into a similar reaction vessel as used in Synthetic Example
12, were placed 356 parts of the water soluble resin varnish
20 2 obtained in Synthetic Example 2, 264 parts of deionized
. water and 2U parts of butyl diylycol and the mixture was
heated, under stirring, to 85C.
To this, the same monomer solution as used in Synthetic
s Example 12 was dropwise added in 2 hours and the mixture was
further stirred for 2 hours to obtain a composition (8)
containing resin particles.
Synthetic Example 14
- 32 -
- ` 1 324224
Pre~aration of resin particles containing composition-9
using the same procedureg of Synthetic Example 12, 576 parts
of the water soluble resin varnish 1 and 192 part~ of~
deionized water were placed ln a reactor and heated, under
stirring, to 85C. To this, a monomer solution consistiny
1 of U parts of styrene, 8 parts of methyl methacrylate, 14
`.3 parts of 2-ethyl hexyl acrylate, 2 parts of 2-hydroxyethyl
methacrylate, 0.4 part of azobisisobutyronitrile and 80
parts of xylene was dropwise added in 2 hours and the
reaction was continued for additional 2 hours to obtain a
Composition ~9) containiny resin particles and having a non-
~ volatile content of 36.3%.
:~ Synthetic Example 15
Preparation of resin particles containing composition-10
~`- 15 Using the same procedures of Synthetic Example 12, 320 parts
~ of the water soluble resin varnish 1, 322 parts of deionized
`~ water and 20 parts of butyl diglycol were placed in a
`i reactor and the mixture was heated, under stirriny, to 85C.
To this, a monomer solution consisting of 50 parts of
styrene, 50 parts of methyl methacrylate, 40 parts of 2-
ethyl hexyl acrylate, 20 parts of 2-hydroxyethyl
methacrylate, 3 parts of azobisisobutyronitrile and 10 parts
of isophorone was dropwise added in 2 hours and the reaction
.3 was further continued for 2 hours to obtain a composition
(10) containing resin particles. A non-volatile content of
this composition was 38.4~.
3 Synthetic Example 16
~3
~ - 33 -
.~ ,
,
-` ~ ` 1 324224
Pre~aration of resin particles containiny composition-ll
Usin~ the same procedures of Synthetic Example 12, 150 parts
of the water soluble resin varnish 1 and 150 parts of-
deionized water were placed in a reactor and heated, under
stirring, to 8SC. To this, a monomer solution consisting
of 40 parts oE styrene, 30 parts of methyl methacrylate, 50
parts of 2-ethyl hexyl acrylate, 1~ partS of 2-hydroxyethyl
methacrylate, 1.5 parts of azobisisobutyronitrile and 20
parts of xylene was dropwise added in 2 hours and the
.r 10 reaction was Eurther continued, under stirring, for 2 hours
to obtain a compo9ition (11) containing resin particles.
The non-volatile content of the composition was 45.5~.
synthetic Example 17
Preparation of comparative resin particles containing
composition-12
/ Using the same procedures of Synthetic Example 12, 320 parts
J of the water soluble resin varnish 1, 400 parts of deionized
, water and 20 parts of butyl diylycol were placed in a
reactor and the mixture was heated, under stirring, to 85C.
20 To this, a monomer solution consisting of 50 parts of
styrene, 50 parts of methyl methacrylate, 40 parts of 2-
ethyl hexyl acrylate, Z0 parts of 2-hydroxyethyl
r methacrylate, and 2 parts of azobisisobutyronitrile was
dropwise added in 2 hours and the reaction was continued,
25 under stirring, for additional 2 hours to obtain a
composition (12) containing resin particles. The non-
- volatile content of the composition was 35.5%.
- 34 -
,: .
,,~ ~ . ,
~'
- ` 1 324224
Synthetic Example 18
Preparation of comparative resin particles-4
Into a 2 liter glass reactlon vessel fitted with a stirrer,
a thermoregulator, and a condenser, were placed 1100 parts
of deionized water and the temperature was raised to 80-C.
To this, an aqueous solution of 6 parts of ammonium
persulfate and 100 parts of deionized water and 5 parts of a
monomer mixture consisting of 21U parts of methyl
methacrylate, 75 parts of 2-ethyl hexyl acrylate and 15
parts of n-dodecyl mercaptane were added and the combined
mixture was stirred for 5 minutes. Thereafter, the
remaining 25~ parts of said monomer mixture were dropwise
added to the reactor in 1 hour. After completion of said
addition, the mixture was stirred for additional 15 minutes,
added with an aqueous solution of 1 part of ammonium
persulfate and 10 parts of deionized water, and the combined
mixture was further stirred and reacted for 1 hour to obtain
a seed emulsion having a non-volatile content of 20%.
Into a similar reaction vessel as used herein, were placed
20 300 parts of deionized water and 25 parts of the aforesaid
seed emulsion, and the mixture was heated to 80-C.
To this, an aqueous solution of 0.1 part of ammonium
persulfate and 20 parts of deionized water was added and
then a pre-emulsion consisting of 155 parts of styrene, 155
parts of methyl methacrylate~ 125 parts of 2-ethyl hexyl
acrylate, 65 parts of 2-hydroxyethyl methacrylate, 0.4 part
of sodium n-dodecylbenzene sulfonate, 0.8 part of ammonium
- 35 -
1 324224
persulfate and 180 p~rts of xylene was dropwise added in 2
hours. AEter completion of said addition, stirring was
continued for 30 minutes and at this stage, an aqueous
solution of 0.2 part of ammonium persulfate and 20 parts of
deionized water was added and the combined mixture was
further stirred and reacted for 1 hour to obtain an emulsion
having a non-volatile content of 41.2%. The mean diameter
of the resin particles contained was 0.7~1 (by electromicro-
scopic determination) and the maximum grain diameter was
lO 0.4 ~. The number average molecular weight of the resin was
9800.
Examples 10 to 15
Into a stainless steel vessel, the materials shown in the
~, following Table 5 were placed and stirred will at a room
1 15 temperature to obtain the respective coating compositions of
3 ~xamples 10 to 15.
'~ 20
, 25
f
-- 36 --
f, `:
, , .
~ 324224
,
.,
..i
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. ~ o ~ U~ ~ ~ o
,... . ..
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.. ~ , o~
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. ~ ~ ~ oo
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, C~
~ o
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~ -C _l
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O 1` U~ 0
. U 0~ ~
J~ C
~ ~ ~ ~n
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a~ ~ . 'O ,,
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h
r
a) X
0~
o
0 ~ ~ - ~ ~ ~ ~
*- *
3~
, ~ ,
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1 324224
: Comparative Examples 9 to 11
Using the same procedures of Example 10, but usin~ the
materials shown in the following Table 6, comparative.
coatlng compositlon= were prepared.
,~ 15
i
~5
- 33 -
~ ' I 324224
~ o o ~
,
. .
~ U~
`. .o ~ ~
:~ ~a, c ,~ c
,` ~ U) .
. C ~ o
1 U~ C o~ ~ C
., U~
U
.~ .~ c ~ c
~-~ ,1
,u U~
s ~ C
. C .,, .c
~ ~ ~ s
o U~ C o
a) o ,,
~. .'' ~ o
O ~ In In C~ C
~ 3 ~ u~ . ~ o ~
~1 3 V ~C o ~
. e O ~
~ ~ ,0~
o ~n
J~
~ C ~-1 t~ ~ ~ ~ Q~ ,a
e u~
Q. ~ a) 0
O S S~
$ s ~ a
h _~ ¦ X
X I a~ o
~,
3q
., - . . .
. .
. -
; . .
.. ,
I 324224
Each of tlle coating compositions obtained in Examples 10 to
15 and Comparatlve Examples 9 to 11 was diluted with
deionized water to a ~ord Cup #4 viscosity of 30 secohds,
and the diluted composition was spray-coated onto a steel
plate, and a~ter setting for 5 minutes, baked at 150C Por
15 minues to obtain a cured coating. The glo~s value, and
smoothness of the coating and time stability of the
respective coating composition were evaluated and the
results were shown in Table 7.
. 10
' 15
'
20
.
- 40 -
1 324224
~; Table 7
coating appearance time stability
s 60 ~loss 20 yloss smoothness
~5 Example 10 ~ ~ excellent excellent
`` 12
~5 13
14
, 15 ~ O ~ ~
~, Comp. Ex. 9 O ~ no good excellent
~ X good good
no good
-- 4 1
~' '
, .
' .
1 3242~4
~ynthetic Example 19
Preparation of hydrophobic resin varnish
Into a 1 liter reaction vessel fitted with a stirrer~ a
! thermoregulator and a condenser, were ulaced 25 part~ of
xylene and the temperature was raised, un~er stirrin~, to
125C. To this, a monomer solution consisting of 30 parts
of styrene, 15 parts of methyl methacrylate, 40 parts of 2-
ethyl hexyl methacryalte, 15 parts of 2-hydroxyethyl
methacrylate and 4 parts o azobisisobutyronitrile was
1~ dropwise added in 2 hours and thereafter, the combined
mixture was stirred for 2 hours to obtain an acrylic,
hydrophobic resin varnish having a non-volatile content of
80~. The number averaye molecular weight of the formed
resin was 5000.
Synthetic Example 20
Prepartion of hydrophobic resin encapsulated resin
particles containing composition-13
Into a 1 liter reaction vessel fitted with a stirrer, a
thermoreyulator and a condenser, were placed 320 parts of
the water soluble resin varnish 1 obtained in Synthetic
Example 1, 300 parts of deionized water and 20 parts of
butyl diglycol, and the mixture was heated, under stirring,
to 85C. To this, a monomer solution consisting of 5U parts
of styrene, 50 parts of methyl methacrylate, 40 parts of 2-
ethyl hexyl acrylate, 20 parts of 2-hydroxyethyl
- methacrylate, 2 parts of azobisisobutyronitrile and 60 parts
of the hydrophobic resin varnish obtained in Synthetic
- 42 -
.,~ .. .... _ ,.. ..... .. . .. , ,... ... _. . .. ..
,
~ ^' 1 324224
;;
xample 19 was dropwise added in 2 hours and the combined
mixture was stirred for 2 hours to obtain a composition
, containing hydrophobic resin encapsulated resin particles.
The non-volatile content of the composition was 42.6%.
.~ 5
Synthetic Example 21
Preparation of hydrophobic resin encapsulated resin
particles containing composition-14
Using the same procedures as stated in Synthetic
10 Example 20, 356 parts of the water soluble resin varnish
3 obtained in Synthetic Example 2, 264 parts of deionized
water and 20 parts of butyl diglycol were placed in a
reactor and the mixture was heated to 85C. Then, the
similar monomer solution as used in Synthetic Example 19 was
dropwise added in 2 hours and the combined mixture was
stirred for 2 hours to obtain a composition containin~ -
hydrophobic resin encapsulated resin particles. The non-
volatile content of the composition was 42.6%.
:J
Synthetic Example 22
Preparation of hydrophobic resin encapsulated resin
particles containing composition-15
As in Synthetic Example 20, 320 parts of the water
soluble resin varnish-l, 300 parts of deionized water and 20
parts of butyl diglycol were placed in a reactor and the
mixture was heated, under stirring, to 85C. Then a monomer
solution consisting of 8 parts of styrene, 8 parts of methyl
methacrylate, 10 parts of 2-ethyl hexyl methacrylate, 6
parts of 2-hydroxyethyl methacrylate, 1.5 parts of azobi-
sisobutyronitrile and 20 parts of hexamethoxy methylol mela-
mine resin was dropwise added in 2 hours and the combined
mixture was stirred for 2 hours to obtain a composition
containing hydrophobic resin encapsulated resin particles.
The non-volatile content of the composition was 49.0%.
- 43 -
,
. ~
- 1 324224
- Synthetic Example 23
`~ Preparation of hydrophobic resin encapsulated resin
;`( particles containing composition-16
~' As in Synthetic Example 20, 320 parts of the water
soluble resin varnish l, 400 parts of deionized water and 10
parts of butyl diglycol were placed in a reactor and the
` mixture
.~
', 10
~,
`~;
'~ 1 5
.
~ 25
`
~ 30
Y,
à 35
43a -
',
~,. . . .
.
~` ` 1 324224
was heatQd, under s~irrlng, to 85C. To this, a monomer
solution consistiny of 75 yarts of styrene, 75 parts of
methyl methacrylate, 60 parts of 2-ethyl hexyl metha~rylate,
30 ~arts of 2-hydroxyethyl methacrylate, 3 parts of
azobisisobutyronitrile and 24 parts of Epicoat lU~l ~Shell
Chemical) was dropwise added in 2 hours and the combined
mixture was stirred for 2 hours to obtain a composition
containiny hydrophobic resin encapsulated resin particles.
The non-volatile content of the composition was 42.6~.
Synthetic Example 24
Preparation of comparative resin particles containing
composition-17
As in Synthetlc Example 2U, 320 parts of the water soluble
resln varnish l, 400 parts of deionized water and 20 parts
of butyl diglycol were placed in a reactor and the mixture
; was heated, under stirring, to 85C. To thisr a monomer
J solution consisting of 5U parts of styrene, 50 parts of
methyl methacrylate, 40 parts of 2-ethyl hexyl acrylate, 20
parts of 2-hydroxyethyl methacrylate, and 2 parts of
azobisisobutyronitrile was dropwise added in 2 hours and the
combined mixture was stirred for 2 hours to obtain a
3 composition containing resin particles. The non-volatile
content of the composition was 35.5%.
J, Synthetic Example 25
Preparation of comparative resin particles 5
Into a 2 liter glass reaction vessel fitted with a stirrer,
a thermoregulator and a condenser, were placed llO0 parts of
- 44 -
` ~ 1 324224
deionized water and the content was heated, under stirring,
~ to 80C. To this, an aqueous solution of 6 parts of
; ammonium persulfate in 100 parts of deionized water and 5
` parts of the monomer mixture of 210 parts of methyl
methacrylate, 75 parts of ~-ethyl hexyl acrylate and 15
3 parts of n-dodecyl mercaptane were added, under stirring,
;` and the combined mixture was stirred for 5 minutes. While
u stirring, the rsmaininy 259 parts of the monomer mixture
; were dropwise added and the combined mixture was stirred for
!. 10 additional 15 minutes.
Thereafter, an aqueous solution of 1 part of ammonium
persulEate in 10 parts of deionized water was added and the
mixture was reacted, under stirring, for 1 hour to obtain a
seed emulsion haviny a non-volatile content of 20%.
~`~ 15 Into a similar reaction vessel as stated hereinabove, were
r~ placed 300 parts of deionized water and 25 parts of the
t abovesaid seed emulsion, and the temperature was raised to
`A 80C. To this, an aqueous solution of 0.1 part of ammonium
peræulfate in 2U parts of deionized water was added and then
a pre-emulsion consisting of 155 parts of styrene, 155 parts
of methyl methacrylate, 125 parts of 2-ethyl hexyl acrylate,
65 parts of 2-hydroxyethyl methacrylate, 5 parts of n-
dodecyl mercaptane, 200 parts of deionized water, 0.4 part
of sodium dodecyl benzene sulfonate, 0.8 part of ammonium
r; 25 persulfate and 15U parts of the hydrophobic resin varnish
obtained in Synthetic Example 19 was dropwise added in 2
-i hours. After stirring for 30 minutes, an aqueous solution
- 45 -
,~., , ~
.
.
- ~ ' , .
1 324224
:`;
of 0.2 part of ammonium persulfate in 20 parts of deionized
water was added and the combined mixture was reacted under
stirring for 1 hour to obtain an emulsion containing~resin
articles. The non-volatile content of the emulsion was
S 41.2%. l'he resin particles were separated from thus
obtained emulsion. ~y an electron microscopic examination,
it was ound that the averaye grain diameter of said
~articles was 0.7~ and the maximum grain diameter was 1.4~.
The number averaye molecular weiyht of the resin was 9800.
. 10 Examples 16 to 20
~ Into a stainless steel vessel, the materials shown in the
;~ followiny Table 8 were placed in and the mixture was stirredwell in a stirrer at a room temperature to obtain the
respective coating composition of Examples 16 to 20.
~'
~ 20
~'
3~
2 25
~.,
~ - 4G -
.
~, .
,
~x`
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Comparative Examples 12 to 14
Using the same procedureg as stated in Examples 16 to 20,
- but substitutiny the following materials for those o~
Examples 16 to 20, comparative coating compositions were
prepared.
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Each of the coating compositions of Examples 16 to 20 and
Comparative Examules 12 to 14 was diluted with deionized
water to a Ford Cup #4 viscosity of 3~ seconds and the
diluted composition was spray-coated on a steel plate.
After setting for S minutes, the coating was baked at 150-C
for 15 minutes to obtain a crosslinked coating. The maximum
film thickness showing no pinholes and the maximum film
thickness showiny no sagginy were determined for the
respective composition, and gloss value and smoothness of
thus obtained coatiny were evaluated. The results are shown
in Table 10.
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Table 10
coatiny appearance time stability
60 gloss 20 gloss smoothness
Example 16 ~ ) excellentexcellent
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? comp. Ex. 12 O ~ no yood excellent
13 ~ X good good
14 ~ o good
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