Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~045A0
A coating composition
Field of the invention
The present invention relates to a coating composition
containing tetrapod-like zinc oxide whiskers, which is
specifically useful as a curing type coating composition in
the form of aqueous type, solvent type or powder paint capable
of resulting a coating with excellent chipping resistance,
abrasive resistance and the like, and being useful as a top
coat or intermediate coat, a road marker or an abrasive
putty. The invention also concerns a curing acceleration
catalyst carried on tetrapod-like zinc oxide whiskers.
Background of the invention
After being applied, coating compositions are usually
cured or hardended at an elevated temperature or room
temperatures.
Thus formed coatings are required, depending on the intended
objects, to be well stand to mechanical and/or chemical
forces. For example, in an automobile industries, various
characteristic properties are required for coating
compositions to be used as a top coat, an intermediate coat,
a repairing putty, road marker and the like.
In a cold area, in order to keep a transportation route, a
considerable quantity of anti-freezing agent comprising
chlorides as sodium chloride, calcium chloride and the like,
and crushed stones are generally spreaded over road surfaces
in winter season. Therefore, an automobile body is, while
200L1L5~1L0
driving, liable to be damaged by leaped stones or splashed mud
and rusted under the influences of high humidity and salt
atmosphere. Thus, in these areas, a top coat composition to
be applied onto automobile bodies and coating system must
fulfill the requirement of resulting a coating with excellent
chipping resistance and corrosion resistance. Usually,
automobile bodies are coated with the lamination o~
phosphating coating, under coating ~electrodeposition primer
coating), intermediate coating and a top coating and in order
to improve chipping resistance, anti-chipping pigments are
usually contained in said intermediate coating. For example,
in Japanese Patent Publication (unexamined) 13334/76, is
disclosed a solvent type intermediate coating composition
containing 75 to 10%, in terms of weight % to the total solid
weight, of ultrafine selicite; in Japanese Patent Publication
(unexamined) 36165/80, a coating composition being excellent
in both chipping resistance and corrosion resistance and
comprising an acidic resin having a particular acid value
added with talc and anti-corrosive pigment; in Japanese Patent
20 Publication (unexamined) 52139/79, an aqueous emulsion coating
composition added with finely pulverized vulcanized rubber as
anti-chipping agent; and in Japanese Patent Publication
(unexamined) 170537/~1, an aqueous chipping resistant sealer
comprising an aqueous coating composition comprising an
aqueous resin and resin microparticles and being excellent in
application characteristics, added with an anti-chipping
pigment and anti-corrosion pigment.
-- 2
200fl540
However, heretofore proposed anti-chipping coating
compositions are all based on the use of considerably larger
quantity of leaf-like or scale-like inorganic pigments as, for
example, talc, selicite, ca-bon black, barium sulfate and the
like having an average diameter of 20~ or less. In these
cases, when formed coatings, the leaf-like or scale-like
pigments are horizontally oliented in the coatings, exhibiting
stress relaxation effect to impacts born from horizontal
shrinkage, modulus of elasticity of coating and the like.
Nevertheless, with respect to chipping resistance and anti-
rust property, the heretofore proposed coating compositions
are not fully of satisfaction and further improvements have
been strongly desired.
In .he coating of outer surface of ship body where a direct
contact with pier wall is often occurred and the coating of
inner surfaces of tank, hopper and pipe lines for storing and
transporting ore, cement, cereal and the like on where severe
mechanical and physical abrasion forces are always exerted,
have been examined a coating composition which comprises a
comparatively soft urethane resin compounded with fibrous
fillers as glass fiber and can result a coating having an
elastic deformation property, and a coating composition which
comprises epoxy/amine based resins and can provide a hard
coating. However, in the former, since the main object is to
prevent coat-scaling through a shock absorption, the formed
coating is indeed excellent in an impact strength, but is
deficient in abrasion resistance and durability. Furthermore,
-- 3
Z~0'~54(~
since it is very difficult to obtain finely pulverized fibrous
fillers, there are problems in application properties
especially in time of spraying and in smoothness of the
resulted coating. Whereas, in the latter, the object is to
improve scratch resistance by increasing an apæarent hardness
of coating, but there is a problem that since the resulted
coating is easily damaged by springing powder or granules,
scaling or peeling of the coating is liable to occur in a
long-term service of the coated materials. Thus, none of the
proposed coating compositions can give fully satisfied
protective coatings.
For the preparation of wood or metal surfaces, or the repair
of pinholes, cracks, crevices or distortion of coating or
depression of automobile bodies, a pasty putty comprising a
mixture of pigment and vehicle selected from oily varnish,
synthetic resin, nitrocellulose, synthetic resin emulsion,
casein or the like has been widely used. These putties are
roughly classified in oil putty (e.g. oil putty, size putty
and the like); synthetic resin putty (e.g. vinyl chloride
putty, urethane putty, polyester putty, vinyl ester putty,
alkyd resin putty and the like); cellulose putty known as
lacquer putty; and aqueous putty (e.g. casein putty, emulsion
putty and the like). In the actual application, most
appropriate type of putty must be selected in due
consideration of degree of damages of -the substrate, type of
substrate, and type of intermediate and top coats and the
like. The selected putty should fulfill -the conditions that
54~
it has a good workability, is excellent in adhesion to both
substrate and top coat, and is easily applicable as a filler
material and give a smooth surface without causing any
slendering in thickness or cracking and is well resistive to
a top coat composition.
However, heretofore proposed putties are not enough in certain
respects. For example, oil putty, casein putty, emulsion
putty and the like take in general a considerable time in
drying; and polyester putty and vinyl ester putty each has the
problem that curing reaction at putty surface is liable to be
hindered through contact with oxygen in air and in extreme
case, fully prohibited at the surface area. At that time,
there causes the question of inferior adhesion and water
resistance of the coating. Usually, after applying putty, the
cured coating is subjected to grinding with sand paper and the
like. At this step, most of the heretofore proposed putties
are liable to generate clogging of abrasive paper, causing
extreme lowering in workability. Today, as a repairing putty
for automobile bodies, have been widely used a two-component
polyester putty, one component comprising as main ingredients
unsaturated polyester resin, filler, unsaturated vinyl
monomers, and curing acceierator and the other component
comprising a peroxide hardening agent, and a three-component
polyester putty comprising the abovementioned two components
and the third component comprising a curing accelerator as
lead naphthenate and the like. Even in these putties,
attempts have been made to improve grinding properties of the
Zl1:)0'~54a3
formed coatings by incorporating into the putties such fillers
as calcium carbonate, clay and the like for the purpose of
improving plasticity of the coating, or by coloring hardening
agent with a dyestuff so that color change of said dyestuff
5 in a curing reaction of putty can be visually examined, and
possible grinding of uncured putties is effectively obviated,
as, for example, in Japanese Patent Publication 120612/84 and
Japanese Patent Publication (unexamined) 91572/87.
However, these could not be said to give a fully satisfied
solution on clogging problem of abrasive paper and further
improvements are still required.
In another application of coating compositions, the so-called
road-marking paint which is brilliantly colored in white,
yellow, red or the like so as to be easily detected by driver
or walker, hardly discolored, excellent in weather resistance
and durability and applicable in a thicker coating is widely
used for indicating road marks as cen-ter line, outer line,
pedestrian crossing, zebra crossing, stop line and the like,
curb marking as no parking sign, and vertical surface causion
marks at bridge footing, electric pole, girder bridge rail,
concrete wall at curve and the like is wisely used.
Heretofore proposed road marking pain-ts generally comprise a
mixture of a vehicle resin, which is comparatively excellent
in weather resistance and durability and is well resistive -to
asphalt exudation and machine oil attack, as, for example,
petroleum resin, C5 resin, Cg resin, polyester resin, phthalic
resin, alkyd resin, maleic rosin resin, rosin modified alkyd
2~ 0
resin, and acrylic resin, inorganic or organic colored
pigments as, for example, durable white or yellow inorganic
pigments as titanium white, zinc white, barium sulfa-te,
lithopone, lead chromate; and other op-tional additives as
loading pigment as calcium carbonate and the like, plasticizer
as liquid alkyd, natural oil, process oil naphthene, dibutyl
phthalate and the like, anti-settling agent as silica, wax and
the like, bluing agent, surface tack eliminator, dispersing
agent, solvent and the like. The may often include reflective
material as glass beads having a reflective idex of 1.4 to 2.0
and are used as a reflecting road sign marker.
Such road marking pains are classified and used, depending on
their compositions, in either form of room temperature curing
type (e.g. solid content 79%), heat hardening type (e.g. solid
15 content 85%) or heat fusion type (solid content 100~).
However, with an ever increasing traffic volume, a more
effective road marker is required. Such marker should be much
more excellent in visibility and especially in return
- reflectivity and whiteness in dark and rainy days, less
expensive, capable of resulting a coating with far improved
durability (abrasion resistance and toughness) and weather
resistance and applicable in thicker coating.
In coating compositions and molding materials, various resins
are used as main ingredient and they are cured by drying at
room temperatures or baking at elevated temperatures. In many
cases, these compositions may further include zinc oxide as
loading pigment or white pigment, and various curing
2 ~ 0L~
acceleration catalysts. Examples of such catalysts are
organotin compounds as a blocker releasing accelerator for
blocked isocyanate in urethane resin composition, various
peroxide catalysts in unsaturated polyester resin composition,
various oxidation or polymerization type dryers, various metal
soaps in fatty acid modified synthetic resin composition,
organic amines as tertiary amines or ammonium salts in epoxy
resin composition, organic acids and metal chelate compounds
in amino resin composition and the like.
The principal object of using such catalyst is to obviate
heterogeneous curing i.e. premature surface dry and deficient
inner curing, as far as possible. However, in the actual
adding operation of such loading pigment or acceleration
catalyst in a coating composition or a molding composi-tion,
it is very difficult, even after adopting a vigorous stirring,
to get a uniform distribution of such catalyst in the
composition. Therefore, there always remains a trouble of
ununiform curing of coating or molding product due to
maldistribution of such catalyst. A considerably longer
curing time is therefore always required.
Thus, there are still remaining various problems in the
respective coating compositions used in each different
applications.
An object of the invention is to provide a novel class of
universal additive to be used in various coating compositions
for various applications. An additional object of the
invention is to provide an in~ermediate coating composition
~:~)O~S40
for automobile bodies which is specifically excellent in
chipping resistance as well as a corrosion resistance.
A further object of the invention is to provide a coating
composition which is specifically excellent in abrasion
resistance and impact resistance and especially useful in the
coating of ship body surface and inner wall coating of tank,
hopper, piping and the like to be used in storage and
transportation purposes for ore, cereal, cement and other
powdery or granular products. It is an additional object of
the invention to provide a high quality putty being free from
clogging of abrasive paper and eapable of resulting an
excellent ground surface. It is also an object of the
invention to provide a novel road marker being excellent in
visuality and especially in return reflectivity and whiteness
in dark and rainy days, less expensive, capable of resulting
a coating with far improved durability (abrasion resistance
and toughness) and weather resistance and applicable in
thicker coating. A further object of the invention is to
provide a curing acceleration catalyst which is specifically
0 useful in a curing type coating composition.
Summary of the invention
According to the present invention, the aforementioned
objeets can be attained by providing
1. A eoating composition comprising a resinous vehicle and
coating additives, which is characterized by further
containing tetrapod-like zinc oxide whiskers each comprising
a central nuelear portion from which ~ crystalline needles
ZO~L~t5Af~0
are outwardly extended each in different direction, average
diameter of said needle measured at the foot portion thereof
being 0.7 to 14~ m and average length of said needle being
3 to 200~ m.
2. A composition according to claim 1 wherein the resinous
vehicle is selected from the group consis-ting of a
combination of at least two resins each having either one
of mutually reactive, crosslinkable functional groups, a
combination of a resin and a compound each having either one
of mutually reactive, crosslinkable functional groups, and
at least one resin having in its molecule both of mutually
reactive, crosslinkable functional groups, the coating
additives include colored pigments and body pigment, and the
amount of said whiskers is 1 to 30% by weight of the total
solid of the composition, which can result a coating with
excellent chipping resistance.
3. A composition according to claim 2 which is formulated in
either one of a water borne paint, a solvent type paint or
a powder paint.
4. A composition according to claim 1 wherein the resinous
vehicle is selected from the group consisting of a
combination of at least two resins or a resin and a compound
each having either one of mutually reactive, crosslinkable
functional groups, and at least one resin having in its
molecule both of mutually reactive, crosslinkable functional
groups providing resulting a coating with Tg value of 90C
or more, and said coating additives include microparticles
-- 10 --
~0~5~0
of natural or artificial hard ceramics, having an average
diameter of 0.1 to 200~ m, selected from the group
consisting of bauxite, silica sand, powder emery, alumina,
zirconia, silica, magnesite and magnesia, the amount of said
whiskers being 10 to 70% by weight of the total solid of the
composition, the sum of said whiskers and said
microparticles being 30 to 80% by weight of the total solid
of the composition, which can give a coating with excellent
abrasion resistance.
5. A composition according to claim 1 wherein the resinous
vehicle is a durable resin selected from the group
consisting of petroleum resin, C5 resin, Cg resin, polyester
resin, ph-thalic resin, alkyd resin, maleic rosin resin,
rosin modified alkyd resin and acrylic resin, and the
coating additives are any combinations of colored pigment,
body pigment, plasticizer, anti-settling agent, bluing
agent, detackifier, dispersing agent, solvent and glass
bead, the amount of whiskers being 9 to 95% by weight of the
total solid of the composition, which is specifically useful
as a road marker.
6. A composition according to claim 1 wherein -the resinous
vehicle is a combination of unsaturated polyester resin and
unsaturated vinyl monomer, and the coating additives include
hardening accelerator and peroxide hardener, the amount of
said whiskers being 1 to 30% by weight of the total solid
of the composition, which is specifically useful as an
abrasive putty.
~0045~(~
7. A composition of any one of claims 1 to 6 wherein the
whiskers are previously treated with a coupler so as to give
hydrophobic proper-ty thereto.
8. A composition according to claim 1 wherein the composition
further contains a curing acceleration catalyst.
9. A composition according to claim 8 wherein the curing
acceleration catalyst is obtained by con-tacting tetrapod-
like zinc oxide whiskers each comprising a central nuclear
portion from which 4 crystalline needles are outwardly
extended each in different direction, average diameter of
said needle measured at the foot portion thereof being 0.7
to 14~ m and average length of said needle being 3 to
200/~ m, with a solution or dispersion of curing acceleration
agent selected from the group consisting of organotin
compound, peroxide, organic acid, organic amine, ammonium
salt and metal chelate, and drying thus treated whiskers.
Preferred embodiments of the invention
The inventors have previously found -that crystalline zinc
oxide whiskers each comprising a central nuclear portion from
which certain number of crystalline needles are outwardly
extended each in different directions can be obtained in a
higher reaction yield by the heat treatment of metallic zinc
powder each bearing an oxide surface coating in an oxygen
containing atmosphere and filed Japanese Patent Applications
on the preparation of such zinc oxide whiskers having the
disclosed characteristic features (named by the inventors as
tetrapod-like zinc oxide whiskers) as Japanese Patent
45~)
Application Nos. 334418/87, ibid 41329/88 and ibid 41330/88.
The crystalline needle portion of said tetrapod-like zinc
oxide whisker may include 3, 2 or in certain circumstances 1
needle, but mostly consists of 4 needles extending outwardly
5 from the nuclear portion each in different axial direction.
The whiskers having decreased number of needles are believed
to have been derived from the original whiskers having 4
needles through breakdown of certain number of the needles
thereof. In certain circumstances, a small amount of plate
10 crystal whiskers are included.
However, regardless of the crystalline form, every X-ray
diffraction diagrams of such whiskers show only zinc oxide
peak and in most whiskers, electron beam diffraction analysis
datas show single crystal structure having least transition
15 and lattice defect. The impurity content is very low and zinc
oxide purity determined by an atomic absorption analysis is
as high as 99.98%. It was thus confirmed that the
abovementioned whiskers are composed of highly pure zinc oxide
and each has a tetrapod-like whisker structure comprising a
20 central nuclear portion from which 4 crystalline needles are
extending outwardly each in different axial direction.
The term "tetrapod-like zinc oxide whiskers" as used herein
shall mean the whiskers having the abovementioned stractural
characteristic features.
25 The present invention relates to practical applications of
such tetrapod-like zinc oxide whiskers to paint area.
The inventors have first found that a coating composition
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;200~5~0
compounded with 1 to 30~ be weight of the total solid of such
tetrapod-like zinc oxide whiskers can result a coating with
excellent chipping resistance and anti-rusting effects as
compared with those of heretofore known anti-chipping coating
composition and hence is very useful as an intermediate
coating in an automobile industries. Furthermore, to our
great surprise, the tetrapod-like zinc oxide whiskers are well
adapted to any of aqueous medium, oily medium and resinous
vehicles for powder coating and therefore, can be added to any
of aqueous paint, oily paint and powder coating, resulting
coatings with excellent chipping resistance and anti-corrosion
properties originated in their unique shapes and properties.
If desired, the whiskers may be previously treated with a
coupler as silane coupler, aluminium coupler, titanate coupler
and the like so as to give hydrophobic properties thereto, and
thus treated whiskers can be advantageously added to oily
paint.
In this first invention, as the resinous vehicle, any of the
following may be satisfactorily used:
a combination of at least two resins each having either one
of mutually reactive, crosslinkable functional groups; a
combination of a resin and a compound each having either one
of mutually reactive, crosslinkable functional groups; and at
least one resin having in its molecule both of mutually
reactive, crosslinkable functional groups. Examples of such
functional groups are carboxyl group, hydroxyl group,
isocyanate group, epoxy group, amino group, imino group,
- 14 -
2~)454()
sulfonic acid group, alkoxy silane group, active methylol
group and the like. Any of appropriate combinations of such
groups may be advantageously used in this invention.
In the case of oily paint, the present anti-chipping coating
composition is prepared by providing a solution or dispersion
of such resins as saturated or unsaturated alkyd resin, acryl
resin, epoxy resin, polyester resin, urethane resin,
poly-alkadiene resin, polyolefin resin, cellulose-acetate-
butyrate resin, petroleum resin, styrene resin or combinations
of such resins with aminoplast resin, nitrocellulose resin,
blocked polyisocyanate or polyisocyanate compounds, in an
organic solvent, and adding to thus prepared vehicle tetrapod-
like zinc oxide whiskers and other optional additives as color
pigment, body pigment, conventional anti-chipping agent (e.g.
talc and the like), anti-corrosive pigment (e.g. metal
chromate, metal phosphate, metal molybdate, metal tungstate,
tannic acid and the like), and other coating additives.
However, in this first aspect of the invention, the amount o~
said tetrapod-like zinc oxide whiskers should be selected in
a range of 1 to 30% by weight of the total solid of the
composition. If the amount of said whiskers is less than 1%
by weight, there is no substantial effect of the whiskers, but
at the level of more than 1% by weight, an excellent chipping
resistance can be obtained even without using any conventional
anti-chipping agents and when co-used with such anti-chipping
agent, there is a sure and marked synergistic anti-chipping
effect. The inventors have found that the maximum content of
- 15 -
z~ s~cp
such whiskers should be preferably limited -to 30% by weight
in this aspect of the invention, and no additional increase
in chipping resistance can be expected with the increased
whisker amount. At that time, pigment volume concentration
will be uselessly increased to a higher level, giving rather
undesired effects on film properties.
Differing from the conventional zinc oxide powder, the present
tetrapod-like zinc oxide whiskers can be stably dispersed in
an oily paint and however, previously mentioned pretreated
hydrophobic whiskers may be more preferably and advantageously
used in this invention.
In the case of aqueous paint, an aqueous emulsion of such
resins as alkyd resin, acryl resin, maleic polybutadiene
. resin, urethane resin, epoxy resin, aminoplast resin, casein,
vinyl resin and the like, or an aqueous solution or dispersion
of the abovementioned resin bearing such functional groups as
acidic group, hydroxyl group, oxirane group, ac-tive methylol
group, amino group, reactive carbon-carbon unsaturation,
isocyanate group, blocked isocyanate group, halogen and other
ZO acidic or basic group may be used as vehicle material, to
which the present tetrapod-like zinc oxide whiskers and other
optional additives as resinous fine particles (for improvement
of appllcation characteristics), conventional anti-chipping
agent, anti-corrosive pigment and other additives are added
to obtain the present anti-chipping coating composition.
At that time, the amount of said tetrapod-like zinc oxide
whiskers should preferably be limited in a range of 1 to 30%
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~(~O'~S4~
by weight of the total solid of the composition, too. An
aqueous anti-chipping sealer can be obtained by the mere
addition of tetrapod-like zinc oxide whiskers in an aqueous
resin vehicle, and if desired, anti-corrosive pigment and
other anti-chipping pigment are further added thereto.
Examples of such anti-corrosive pigments are metal chromate,
metal phosphate, metal molybdate, metal tungstate and tannic
acid, and appropriate metals are the members belonging to
Groups I, II, III or IV of the Periodic Table as, for example,
lithium, potassium, sodium, calcium, strontium, barium, zinc,
lead, aluminium and the like. The amount of such anti-
corros1ve pigment is in general 2 to 50% by weight of the
total solid of the composition, but the maximum limit should
preferably be determined at the level of causing no adverse
effects on storage stability of the coating composition and
coating properties and especially water resistance thereof.
Since the desired anti-chipping effect is surely obtained with
the present tetrapod-like zinc oxide whiskers, there is no
need of using additional anti-chipping pigment. However, when
such pigments are used together with the present whiskers for
synergistic and economical reasons, such pigments are selected
from the known anti-chipping pigments as leaf-like or scale
like talc, selicite, carbon black, barium sulfate having an
average diameter of 20~ or less and the sum of such pigment
and the present tetrapod-like zinc oxide whiskers should
preferably be determined in a range not exceeding over the
upper limit of 50% by weight of the to-tal solid of the
~o~o
composition. Otherwise, there is a tendency that smoothness
and other desired properties of the coating will be
undesirably lowered.
In this invention, the anti-chipping coating composition may
also be furnished in the form of powder coating. In a
conventional powder coating, a binder resin as epoxy resin,
vinyl resin, chlorinated polyether resin, polyurethane resin,
polyamide resin, polyester resin, cellulose resin and the like
is compounded with a hardener, pigment and other additives and
the mixture is formulated into powdery particles having an
average diameter of 50 ~ or less. Such powder is applied by
a fluidized bed coating system, an electrostatic coating
system, a powder atomizing, a flame spray coating or a flock
coating system onto a heated substrate. In this invention,
tetrapod-like zinc oxide whiskers are compounded and kneaded
with the abovementioned powder materials in an amount of 1 to
30% by weight of the total solid of the composition. As is
the case of the abovementioned oily paint, the present
whiskers may be pretreated to give hydrophobic properties
thereto.
In either form of the anti-chipping coating compositions, the
present compositions may further include various coating
additives as pigment, wetting agent, levelling improving
agent, dispersing aid, anti-sagging agent, solvent, ionic
regulator and the like.
Though the present anti-chipping coating composition is
specifically useful as an intermediate coating for automobile
- 18 -
2~540
bodies, it may also be applied as a top coat or an under coat
by selecting an appropriate resinous vehicle and coating
additives as desired. Thus, in the first aspect of the
invention, a novel pigment of tetrapod-like zinc oxide whisker
is used as an anti-chipping pigment in a specified amount in
a coating composition. Regarding the working effects of such
whiskers, the inventors are now of the opinion that since the
whiskers each has the specified shape, they must have an
excellent shrinkage resistance in both horizontal and vertical
directions in a coating as well as prominent elastic modulus,
for which reasons an excellent anti-chipping effect is given
to the coating and as a conse~uence thereof, rust generation
must be effectively controlled.
In the second aspect of this invention, is provided a coating
composition which is excellent in abrasion resistance and is
useful as an outer surface coating o~ ship bodies where a
direct contact with pier wall is often occurred and as an
inner surface coating of tank, hopper and pipe lines for
storing or transporting ore, cement, cereal or the like where
sever mechanical and physcal abrasion forces are always
exerted thereon, comprising a resinous vehicle capable of
resulting a coating with Tg value of 90C or more, 10 to 70%
by weight of the total solid of the composition of tetrapod-
like zinc oxide whiskers, and microparticles of natural or
artificial hard ceramics, having an average diameter of 0.1
to 200~ m, selected from the group consisting of bauxite,
silica sand, powder emery, alumina, zirconia, silica,
- 19 -
2~0~54~
magnesite and magnesia, the sum of the tetrapod-like zinc
oxide whiskers and said hard ceramics microparticles being 30
to 80% by weight of the total solid of the composition.
According to the inventors' studies, it was found that though
hard ceramics microparticles are most effective additives for
the improvemen-t in hardness of coating, but when said
improvement resorts to the ceramics microparticles alone,
there always occur undesired decrease in impact strength and
that when a specified amount of the present tetrapod-like zinc
oxide whiskers is caused with the hard ceramics
microparticles, both hardness and impact strength are greatly
improved. This might be due to the fact that the present zinc
oxide whiskers, from their particular structural
characteristics, can bring favorable effects on structural
strength of coating in both ver-tical and horizontal
directions, resulting further improvement in abrasion
resistance, and at the same time, improving follow-up action
to collision deformation, thereby resulting a marked increase
in impact strength.
As a resinous vehicle, any of the resinous materials
customarily used in a high abrasion resistant coating
compositions may be satisfactorily used, providing resulting
a coating with Tg value of 90C or more. They are of curing
type, and therefore, are selected from a combination of at
least two resins or a resin and a compound each having either
one of mutually reactive, crosslinkable functional groups or
at least one resin having in its molecule both of mu-tually
- 20 -
2~C)4~
reactive, crosslinkable functional groups. To obtain a highly
anti-abrasive coating, the resin should preferably be selected
from the members capable of resulting a comparatively hard
coatings. For this reason, preferable resins are epoxy resin,
unsaturated polyester resin, phenol resin and especially
Resorcin type phenol resin, urea resin, polyamide resin, acid
anhydride resin and the like, optionally compounded with
polyamine, ketimine, polyisocyanate and the like.
Particularly preferable member is the combination of epoxy
resin and polyamine compound.
The amount of tetrapod-like zinc oxide whiskers, in this
aspect of this invention, should be in a range of 10 to 70%
by weight of the total solid of the composition. This is
because, if the amount is less than 10% by weight, the
intended objects and effects cannot be fully attained, and if
it exceeds over the upper limit of 70~ by weight, various
problems as lowering in application characteristics and
especially spraying workability and loss in coating appearance
are inevitably occurred.
In this aspect of the invention, microparticles of natural or
artificial hard ceramics having an average diameter of 0.1 to
200~ m are compounded -together with the abovementioned
whiskers. Fxamples of such ceramics microparticles are
bauxite, silica sand, powder emery, alumina, zirconia, silica,
magnesite and magnesia. However, the invention can never
limited to those ceramics only and any other similar hard
ceramics may also be used satisfactorily. In this aspect of
- 21 -
2~0~54~)
tha invention, it is, however, essential that the sum of said
ceramics microparticles and said zinc oxide whiskers must be
within a range of from 30 to 80% by weight of the total solid
of the composition. This is because, if the total amount of
said ceramics microparticles and said whiskers is less than
30% by weight, it is unable to get -the desired effects, i.e.
improvements in both impact strength and abrasion resistance,
in full, and if it is over 80% by weight, there is a tendency
that the formed coating will become too brittle and
application characteristics and especially spraying
workability and coating appearance and especially smoothness
are liable to be ruined. The present coating composition may
further include fibrous fibers as, for example, glass fiber,
potassium titanate fiber, rock wool, alumina fiber and the
like, as desired. However, in a spraying application, such
fibers should not preferably be added because of the fear of
occurrence of granular structure. Solvent, pigment and other
coating additives may be added as desired.
The present coating composition may be applied on a substrate
by any conventional means as brushing, roll coating, and spray
coat1ng. However, in the coating on inner surface of tank and
the like, particular preference is given to spraying system,
including air spraying and airless spraying. The coating thus
formed should have a Tg value of 90C or more. The term "Tg
value" as used herein shall mean dynamic Tg value ~by
expansion vibration, number of vibration 11OHZ), which is the
peak value of Tan~ measured by using Leovibron DDV-II
20045~()
(Orientec K.K.), at the time of increasing -temperature at a
rate of 1C/minute, starting from room temperature. As
already stated, the abovementioned coating composition of this
invention is excellent in workabili-ty and capable or resulting
a coating with excellent impact strength, abrasion resistance
and appearance and therefore, is specifically useful as a top
coat for outer surface of ship bodies and inner surface of
hopper, tank, pipe line for storing or transporting powdery
granular products.
In the third aspect of this invention, is provided a road
marking coating composition added with 9 to 95% by weight of
the total solid of the composition of the present tetrapod-
like zinc oxide whiskers.
Usually, for road marking purpose, is used a coating
composition comprising a durable resin vehicle as petroleum
resin, C5 resin, Cg resinl polyester resin, phthalic resin,
alkyd resin, maleic rosin resin, rosin modified alkyd resin
and acrylic resin, added with such additives as color pigment,
body pigment, plasticizer, anti-settling agent, bluing agent,
detackifier, dispersing agent, solvent and the like. Glass
bead may also be sometimes added as a light reflecting
material. In this invention, previously mentioned tetrapod-
like zinc oxide whiskers are added to any of the known road
marking coating compositions in a specified amount. By the
adoption of such whiskers, various properties of road marking
coating composi-tions are greatly improved.
1. Since the abrasion resistance and impact strength of the
- 23 -
2 (~1~1 L1L ~i 'lL ~
formed coating are greatly increased, durability of road
marking composition is greatly improved.
2. Since the tetrapod-like zinc oxide whiskers can strongly
absorb ultraviolet rays and do have excellent chalking
resistance (deterioration by acid is controlled by the
reaction of said whiskers with an acidic oxidation product
of binder material), weather resistance of the formed
coating is greatly improved.
3. Since the tetrapod-like zinc oxide whiskers can form a
bulky structure by the stack of a large number of cubic
whiskers, the coating composition is particularly suitable
in a thicker coating.
Thus, the present tetrapod-like zinc oxide whiskers are ~uite
useful additive for road marking coating compositions, acting
as white pigment, light reflecting agent, weather resistance
improving agent, mechanical strength improving agent, thicker
coating aid and the like.
The amount of such whiskers in a road marking coating
composition may be varied in a wide range depending on the
intended object and effect. There is, however, a preferable
range, as a matter of course, from -the effectual point of
view. Too large quantity is not desired because of producing
a brittle coating. Usually, the amount of the present
whiskers is selected in a range of from 9 to 95% by weight,
preferably 20 to 90% by weight, of the total solid of the
composition. The present road marking coating composition may
be applied on road surface by any conventional means.
- 24 -
20~L~LSi'lL(~
However, under certain circumstances, a part of whiskers to
be added in a road marking paint, e.g. about 5 to 15% by
weight of the total whiskers, may be cut from such paint, and
after applying the paint on road, the cut amount of whiskers
may be directly spreaded on the coated road surface, thereby
attaining far improved light-reflecting and abrasion
resistance of the finished coating.
In the fourth aspect of the invention, is provided a thicker
coating abrasive putty which is formulated into 2 packs, one
containing a putty base comprising unsaturated polyester
resin, filler and unsaturated vinyl monomer and the other
con-taining a peroxide hardening agent, or 3 packs further
including the third pack containing a hardening accelerator,
at least part of said filler, corresponding to 1 to 30% by
weight of the total solid of the composi-tion, being the
present tetrapod-like zinc oxide whiskers.
This invention was based on the inventors' novel finding that
when the te-trapod-like zinc oxide whiskers are compounded as
filler material with a putty composition in a specified
amount, an appropriate viscosity is given -to the putty and
moreover, a troublesome question of clogging of abrasive
papaer in grinding operation can be ingeniously solved out.
The putty composition compounded with such whiskers is free
from slendering in thickness of coating and can be used as an
ideal thicker coating putty. Thus, the invention can be
applied in various putties to be subjected to post grinding
operation.
- 25 -
)4S~)
When the present tetrapod~like zinc oxide whiskers are added
in place of or in addition to body pigment in an oily putty
comprising as main ingredients oily varnish, body pigment and
color pigment, which has the drawbacks of belated drying and
thicker coating difficulties, drying and thicker coating
properties are advantageously improved.
When the present whiskers are added to vinyl chloride putty
comprising vinyl chloride resin, color pigment, body pigment,
plasticizer, stabilizer and the like and being suffered from
slendering problem, an improved vinyl chloride putty having
no slendering problem can be obtained.
When the tetrapod-like zinc oxide whiskers of the invention
are added as filler to urethane putty, polyester putty or
alkyd resin putty, it is able to obtain the corresponding
putty being free from slendering in thickness and having an
improved abrasion resistance.
Among them, particularly important putty for the repairing of
automobile bodies is a polyester putty. Therefore, this type
of putty shall be more fully explained herein-under.
In the repairing of damaged automobile bodies, in order to
flatten the uneven surface of processed sheet metal, a sheet
metal putty is first applied, and after grinding with a sand
paper, a poly-putty i5 applied, grinding with a fine sand
paper is again carried out, and subsequently coating
operations including primer surfacer coating are carried out.
The polyester putties used in such an application are pasty
or putty like compositions comprising as main ingredients,
- 26 -
2~!OL7~
unsaturated polyester resin and unsaturated monomers,
optionally added with pigment, stabilizer, diluent, solvent,
thermoplastic resin and other additives, as desired. At the
time of actual use, -the putty composition is mixed with a
hardening agent as peroxide and the like, and the mixture is
applied by an appropriate means as spatula, on a substrate and
cured at room temperatures. However, since the curing
conditions are only judged by finger touch and touch feeling
and degree of progress in curing reaction are not always
equivalent to, there often produces an adhesion failure
between iron face and putty at the time when the subsequent
grinding operation is carried out with the coating under
insufficiently cured or incurred conditions.
Furthermore, surface area and thin film portion of polyester
putty are often contacted with oxygen in air, resulting
incurred portions, which must be removed from the coating by
grinding with sand paper or the like, otherwise generating the
problems of adhesion failure and inferior water resistance of
the coating. Therefore, for the purpose of detecting the
degree of progress in curing reaction, attempts have been made
to add various dyestuffs in hardening agent or putty base.
As the most advanced technique, in Japanese Patent Publica-tion
(unexamined) No. 91572/87, is disclosed a two components (A
and B) putty, in which
5 A component consists of
15 to 30 wt% of unsaturated polyester resin
40 to 60 wt% of filler
- 27 -
~:OO~S40
10 to 20 wt% of unsaturated vinyl monomer
1 to 2 wt~ of hardening accelerator
and optional additives, and
B component consists of 2 to 3 wt% of peroxide hardener,
characterizing by including in said A component, 0.001 to 5
wt% of the total solid of said A component of an anthraquinone
dyestuff represented by the formula:
O NHR1
` ~ R2 (I)
0 R3
wherein R1 is selected from the group consisting of hydrogen,
lower alkyl, phenyl and alkylphenyl; R2 is selected from the
group consisting of hydrogen, alkoxy, aryloxy and amide; and
R3 is amino group, imino group or hydroxyl group,
or a mixture of said anthraquinone dyestuff ~I) and an azo
dyestuff ~II) and/or azo dyestuff (III) represented by the
formula:
X Z R4
N02 ~ N=N ~ N (II)
Y C2H40H
N ~ > ~ \ (III)
S R5 2H~H
wherein X and Y each represents hydroyen, Cl or Br; Z is
methyl or Cl; R4 is selected from the group consisting of
- 28 -
2~34~0
hydrogen, methyl, ethyl and hydroxyethyl; R5 is hydrogen or
methyl group.
Said putty, when mixed (A) with (B) and applied on a
substrate, will be disclored with the progress in curing
reaction and insufficiently cured or incurred portion at the
putty surface by the attack of oxygen in air will be visually
detected. Therefore, the object of the disclosed invention
is to effect precise determination of holding time for curing
reaction and optimum control of grinding operation by visual
means in place of heretofore used intuitional determination
means. Thus, the said invention does not concern an
improvement in grinding properties of putties themselves.
Now, the inventors have found that when tetrapod-like zinc
oxide whiskers are used as filler material in a putty
composition, well balanced, two conflicting properties, i.e.
anti-abrasive property and grinding property, are given to the
putty due to the particular structure and properties of said
whiskers, and moreover, thus obtained putty can be applied in
a thicker coating without the fear of slendering problem.
In a particularly preferable embodiment of this invention, is
provided a two packs putty composition, one pack containing
a putty base comprising as main ingredients, unsaturated
polyester resin (preferably 15 to 30% by weight), filler
(preferably 40 to 60% by weight), unsaturated vinyl monomer
(preferably 10 to 20 % by weight) and hardening accelerator
(preferably 1 to 2% by weight) and the other pack comprising
peroxide hardener (preferably 2 to 3% by weight), or a three
- 29 -
~0~ 540
packs putty composition, containing, in addition to the
abovementioned two packs, the third pack containing additional
accelerator, charac-terizing by substituting tetrapod-like zinc
oxide whiskers for at least one part of said filler.
Such putty is specifically useful as a repairing putty for
automobile bodies.
The unsaturated polyester used in this in~ention has an acid
component comprising unsaturated acid or a mixture of
unsaturated acid and saturated acid, and a polyhydric alcohol
component. Examples of unsaturated acids are maleic
anhydride, maleic acid, fumaric acid, itaconic anhydride,
itaconic acid and the like and the examples of saturated acids
are phthalic anhydride, phthalic acid, terephthalic acid,
isophthalic acid, het acid, adipic acid, tetrahydrophthalic
anhydride and the like.
Examples of polyhydric alcohols to be reacted with the
abovementioned acid are ethylene glycol, propylene glycol,
diethyleneglycol,triethyleneglycol, dipropyleneglycol,
bisphenoldioxypropylether, 1,3-butylene glycol,
2,3-butylene glycol, neopentyl glycol, trimethylolpropane,
glycerol and the like.
As an air drying component, one may use polyhydric alcohol
allyl ethers as, for example, pentaerythritol triallyl ether,
trimethylolpropane diallyl ether, glycerine monoallyl ether,
trimethylolethane diallyl ether, glycerine diallyl ether and
the like. These are ethers having in their respective
molecule at least one hydroxyl group. As the content of allyl
- 30 -
5~0
groups, it is preferred to be 0.05 to 2 moles, mos-t preferably
0.1 to 1.5 mole, as allyl group per mole of acid component.
Such unsaturated polyester resin is combined with
polymerizable unsaturated monomers in the present put-ty.
Examples of said monomers are styrene, vinyl toluene,
chlorostyrene, ~-methyl styrene, divinylbenzene, acrylic
ester, methacrylic ester, glycidyl methacrylate, vinyl
acetate, diallyl phthalate, vinyl pyrrolidone, ethylene
diacrylate, hydroxyethyl acrylate, TMP-triacrylate and other
crosslinking monomers.
Examples of pigments are titanium white, cyanine blue, chrom
yellow, watching red, iron oxide, carbon black, aniline black
and the like.
In this invention, tetrapod-like zinc oxide whiskers are
selectively used as filler material. However, if desired,
other conventional filIers as calcium carbonate, clay, talc,
mica, asbestos powder, finely pulverized silica, barium
sulfate, zinc stearate, lithopone and the like may be
additionally used.
For the purpose of weight-cut and better abrasive resistance,
microbaloon is preferably compounded. Examples of
microbaloons are silica baloon, perlite baloon, resin baloon
and the like.
As the curing accelerator, cobalt octonate, cobalt
naphthenate, manganese naphthenate and the like are preferably
used. Besides the above, the following may be added as
optional additives -to said (A) component.
1. Stabilizer:
as hydroquinone, hydroquinone monomethyl ether,
toluhydroqyinone, p-benzoquinone, 2,5-di-tert-butyl
paraquinone, 2,5-di-tert-amyl hydroquinone, 2,5-di-tert-
butyl hydrotoluquinone, mono-tert-butyl hydroquinone,
2,6-di-tertbutyl p-cresol, tert-butyl catechol and the like.
2. Diluent:
as ethyl acetate, toluene, xylene, methanol, ethanol,
butanol, acetone, MIBK, MEK, Cellosolve, diacetone alcohol
and the like.
3. Thermoplastic resin:
as cellulose acetate butyrate, nitrocellulose, vinyl acetate
resin, vinyl chloride resin, acryl resin, butylated
melamine, butylated urea and the like.
4. Other additives:
as phosphoric acid, tartaric acid, phosphorous acid, fatty
acid, silicone oil, surfactant, paraffin wax and the like.
As the hardening agent to be used as B component, any of the
known compounds capable of easily generating radicals by the
action of heat or ultraviolet rays may be satisfactorily used.
Examples are methyl ethyl ketone peroxide, cyclohexanone
peroxide, benzoyl peroxide, dicumyl peroxide, tert-butyl
perbenzoate and the like.
In the present putty composition, the hardening agent must be
packed in a separate package. The main putty component (A)
must have the following composition:
15 to 30% by weight of unsaturated polyester resin
20~1~5~0
40 to 60% by weigh-t of filler
10 to 20% by weight of unsaturated vinyl monomer, and
1 to 2% by weight of curing accelerator.
When the component (A) and component ~B) are mixed together,
thus obtained putty will be completely cured wi-thin about 30
minutes.
By the adoption of tetrapod-like zinc oxide whisker filler,
clogging of abrasive paper at the time of grinding operation
can be almost completely controlled and thus obtained putty
is free from slendering in thickness of applied coating,
capable of resulting a thicker coating with excellent grinding
property and abrasion resistance and excellent adhesion to
intermediate and top coatings. An excellent ground surface
can be obtained therewith.
In the fifth aspect of this invention, is provided a curing
acceleration catalyst being useful in a thermosetting type
resinous composition and comprising tetrapod-like zinc oxide
whiskers carried with a catalyst selected from the group
consisting of organic tin compound, peroxide, organic acid,
organic amine, ammonium salt and metal chelate compound.
The inventors have found that the present tetrapod-like zinc
oxide whiskers are excellent carrier for certain type of
catalysts which are customarily used in paint or molding field
and on the basis of this finding, the presen-t invention has
been made.
The first group of catalysts suitably carried with the present
tetrapod-like zinc oxide whiskers are organic tin compounds
- 33 -
~045~
customarily used as block-releasing agen-t for blocked
isocyanates, one of the raw materials of urethane resin.
Examples of such organic tin compounds are dibutyl tin oxide,
dibutyl tin dilaurate, dibutyl tin maleate, dimethyl tin oxide
5 and the like.
The second group of catalysts are various peroxides used as
radical generators in unsaturated polyester resin compositions
and the like. Examples are benzoyl peroxide, lauroyl
peroxide, acetyl peroxide, t-butyl hydroperoxide, cumen
hydroperoxide, MEK peroxide, dicumyl peroxide and the like.
The third group of catalysts are driers to be used as
decomposition accelerator, as, for example metal carboxylates,
the metal being cobalt, manganese, barium, cerium, lead, zinc,
calcium, titanium, zirconium, iron, copper, tin, molybdenium
and the like, and tertiary amines as triethylamine,
triethanolamine, 4,4-(tetramethylamino) diphenyl methane,
1-(2-hydroxyethyl)-tetrahydroquinoline and the like,
quaternary ammonium salts and acids as p--toluenesulfonic acid,
dinonyl naphthalene disulfonic acid and the like. sesides the
above-said members, any of the known curing accelerators other
than acids or bases which will form complexes with zinc oxide
may be satisfactorily used in this invention.
In preparing the present curing acceleration catalyst, one of
the abovementioned catalyst is first dissolved or dispersed
in water or an appropriate organic solvent, and to this, the
abovementioned tetrapod-like zinc oxide whiskers are contacted
and dried. To ~ake the whiskers contact with the catalyst
- 34 -
2()~)415~CI
solution or dispersion, dipping, spraying and other
conventional means may be satisfactorily used. The present
curing acceleration catalyst thus obtained may be used as a
substitute for all or a part of zinc oxide and curing
accelerator in a coating composition or a molding material
which is permissible to add with zinc oxide as a body pigment
or white pigment and which is desired to add with the
abovementioned curing ca-talyst.
By the adoption of the present curing acceleration catalyst,
the curing accelerator can be uniformly distributed in said
composition because of the excellent dispersion properties of
the tetrapod-like zinc oxide whisker in such medium, and hence
an excellent uniform hardening of said coating composition or
molding composition can be obtained~ Furthermore, since the
zinc oxide whiskers can be used as a body pigment or white
pigment as they are, none of the undesired effects derived
from the presence of foreign material in -the system as is the
case with other carrier materials will be produced. The
present tetrapod-like zinc oxide whiskers each has the
specific structure and comparatively small bulk density~ which
are specifically benefical for the whiskers being used as the
carrier for curing accelerators. Since the present whiskers
are excellent in heat resistance and well stand against normal
baking or molding temperature and curing temperature, they are
likewise very useful as filler material in a coating
composition or molding ma-terial.
- 35 -
;~0~5~)
The invention shall be now more fully explained in the
following Examples. Unless otherwise being stated, all parts
and % are by weight.
Examples of anti-chipping coating composition:
Example 1
Preparation of resinous fine particle (1):
Finedic M 6107 (1) 500 parts
Epicoat 1004 (2) 500
Rutile type titanium oxide 100
The abovementioned materials were fuse-mixed by using a
heating mixer and after allowing to cool the formed mass was
pulverized in a grinder at room temperature to obtain
resinous fine particles (1) having a maximum diameter of 45/~
(1) ... Polyester resin, Tm 110C, HO value 0, acid value 55,
trademark of Dainippon Ink K.K.
(2~ ... Epoxy resin, epoxy equivalent 950, trademark of Shell
Chem. Co.
- 36 -
2~Sfl~
Preparation of coating paste (1):
aqueous varnish (3) 300 parts
resinous fine particles (1) 70
selicite 16
tetrapod-like zinc oxide whisker 16
carbon black 5
zinc chromate 32
Rutile type titanium oxide 70
deionlzed water _ 90
Total 599 parts
(3) ... aqueous resin, maleic anhydride modiEied 1,4-
polybutadiene resin, neutralized with dimethyl
ethanol amine acid value 90, neutralization rate 80%,
solid 30% by weight, molecular weight 1,300.
The abovementioned materials were placed in a 1l stainless
steel vessel and -the content was mixed and dispersed well by
means of paint conditioner, at room temperature for 30
minutes, to obtain a gray colored coating paste (1).
Preparation of coating composition (1)
Into a 11 stainless steel vessel, were placed 400 parts of
the coating paste ~1) and 25 parts of hexamethoxymethylol
melamine resin (Cymel 303, trademark of Mitsui Cyanamide
K.K., solid content 98% by weight), and the con-tent was mixed
and dispersed well in a laboratory mixer at room temperature
for 15 minutes to obtain a gray colored coating composition
(1 ).
2~0'~5~()
Comparative Example 1
A similar gray colored coating composition was prepared
as in Example 1, but substituting a common zinc oxide powder
(Reagent 1st grade) for tetrapod-like zinc oxide whiskers.
Example 2
Vsing 60 parts of oil-free polyester resin (Mn 1700, acid
value 10, OH value 60, NV 60%), 40 parts of butylated melamine
resin G 821-60 (manufactured by Dainippon Ink, NV 60%), 30
parts of Titanium R-820 (manufactured by Ishihara Sangyo),
12.5 parts of tetrapod-like zinc oxide whiskers previously
surface-treated with KBM 403 (silane coupling agent,
manufactured by Shinetsu Silicone K.K.), 2.0 parts of carbon
black and 15.5 parts of xylene, a coating composition (2~ was
prepared in a usual way.
Example 3
The same experiment as stated in Example 2 was repeated
excepting using untreated, tetrapod-like zinc oxide whiskers.
Each coating composition prepared in the abovementioned
Examples and Comparative Example, was diluted with a coating
thinner to a Ford Cup #4 viscosity (20C) of 25 seconds and
thus obtained diluted composition was applied by spraying
means onto a steel plate previously coated with an
electrodeposition coating, Power top U-1000-gray (manufactured
by Nippon Paint Co., Ltd.), so as to be a dry film thickness
of 30,v 40~, and then baked at 150C for 30 minutes.
Thereafter, Orga G 25 white (melamine alkyd based top coat
composition, trademark of Nippon Paint Co., Ltd.) was applied
-- 38 --
Z~ 5~
to give a coating of dry film -thickness of 35~ 45~u, and baked
at 140C for 30 minutes.
Table 1
¦ ¦EX.1 ~x.1 ¦ Ex 2 I~x 3
. . _ .
number of scratches 4 -- 18 5--l 8
num_er of rusts I 28 45 25 ~ 30
The test method and evaluation means used are as follows:
Test method;
50g of JIS No. 7 crushed s-tones and brought collision with
the test plate at a right angle at -20C by using 4Kg/ctn2
of air pressure.
Evaluation;
Chipping resistance effect was evaluated by the following
two items.
Number of scratches ... number of scratches each having a
damaged diameter of 1mm or more were
visually measured and counted in 5x7cm area
Rust number ...... test plate was sprayed with an a~ueous
saline water and after elapsing 24 hours,
number of rusts was visually counted.
The test results are shown below.
Examples of abrasion resistant coating composition:
- 39 -
2 ~J~L~
Example 4
To 220 parts of Intergard paint (room temperature curing
type liquid epoxy/polyamine anti-abrasive paint for ship
coating use, trademark of Nippon Paint Co., Ltd.), which
includes 72 parts of bauxite powder, were added 26 parts of
tetrapod-like zinc oxide whiskers previously surface-treated
with silane coupling agent KBM-403 (manufactured by Shinetsu
Kagaku K.K.) and the mixture was dispersed well in SG mill for
1 hour to obtain a coating composition (1).
The abovementioned whiskers (supplied by Matsushita Elect.
Co.) were composed of highly pure zinc oxide crystals each
comprising a center nuclear portion from which 4 crystalline
needles are extending outwardly in each different direction,
diameter of said needle measured a-t the foot portion being 0.8
m and its length being 3.5~ m.
35.5 parts of EG hardener ~polyamine hardener for Intergard
pain-t, manufactured by Nippon Paint Co., Ltd.) were added with
the abovementioned coating composition and the mixture was
applied on 70mmx130mmx3t sandblasted steel plate by spraying
means so as to give a dry film thickness of 120~, dried at
60C for 3 days and then allowed to leave at room temperature
for 1 day.
The coating thus obtained was subjected to the following
tests.
Abrasive weight-loss test:
Taber abrasion test (JIS-K5665) was carried out (1kg load,
1,000 times rotation)
-- 40 -
20~ 5i40
Impact strength lest:
Gardner impact test was carried out, under conditions given
in Table 2, and diameter of inflated damage was measured.
Pencil hardeness test was also carried out.
The test results are shown in Table 2.
Comparative Example 2
The similar experiment was carried out as in Example 4,
but in this experiment, 20 parts of bauxite powder were used
in place of tetrapod-like zinc oxide whiskers.
The test results are also shown in Table 2.
Table 2
._ _ . ,
_ Ex.4 Com~.Ex
Abraslon weiqht_loss~ 21mq _ 33mq
Impact test
1kg -1m 1Omm 15mm
1kq -0.5m _ _8mm 13mm
. Pencil hardeness _ 3H _ H _
Tg _ _ 113C 82C
- 41 -
~0045~
Examples of road marking coating compositions:
Example 5
Onto an asphalt-made test block, the following solvent
welding type under coating compositions:
Under coating composition;
Petroleum resin 10.0 parts
toluene ~5.0
ethyl acetate 45.0
Then, the following solvent welding type road marking white
paint was applied on by using a flow coater and dried at room
temperature for 3 minutes or more.
The coating was then evaluated by the following tests.
Duarability;
Impact test with a rubber hammer was carried out and
durability was evaluated by the degree of failure of
coating
Weather resistance;
Weather-0-meter and ultra-violet ray irradiation were used
Thicker coating workability;
Application easiness was judged by an actual thicker
coating.
Visual cognition at dark time
This was judged by a driver at the actual driving at night.
The tést results are shown in Table 3.
Examples 6~ 10
The similar experiments as stated in Example 5 were
repeated, excepting substituting the followings for the
- 42 -
~4S~
solvent welding type coating composition of Example 5.
[Example 6]
Petroleum resin 20.0 parts
soy bean oil 5.0
titanium white 10.0
tetrapod-like zinc oxide whiskers 55.0
glass bead 10.0
[Example 7]
Petroleum resin 25.0 parts
soy bean oil 5~0
titanium white 10.0
calcium carbonate 40.0
tetrapod-like zinc oxide whiskers 20.0
[Example 8]
Petroleum resin 25.0 parts
soy bean oil 5.0
titanium white 10.0
calcium carbonate 12.0
tetrapod-like zinc oxide whiskers 28.0
glass bead 20.0
[Example 9]
Petroleum resin 20.0 parts
soy bean oil 5.0
tetrapod-like zinc oxide whiskers 75.0
In this Example, the zinc oxide whiskers are used in both
senses of filler and pigment.
- 43 -
20~L~L5a~a~
[Example 10]
Petroleum resin 25.0 parts
soy bean oil 5,0
tetrapod-like zinc oxide whiskers 38.0
calcium carbonate 12.0
glass bead 20.0
Comparative ExamPle 3
The same experiment as stated in Example 9 was repeated,
excepting substituting the whiskers having the dimensions
shown in the ~ollowing Table 3 ~or the whiskers of Example 9.
Comparative Example 4
The same experiment as stated in Example 9 was repeated,
excepting substituting zinc white (France No.1) for the
tetrapod-like zinc oxide whiskers o~ Example 9.
5 Comparative ExamPle 5
The same experiment as stated in Example 5 was repeated,
excepting substituting the ~ollowing conventional road marking
paint for the paint of Example 5.
Petroleum resin 20.0 parts
soy bean oil 5.0
titanium white 10.0
calcium carbonate 45.0
glass bead 20.0
Example 11
Onto an asphalt-made test block, the following paint type
(room temperature curing type) road marker white was applied
by using a roller, and allowed to drying at room tempera-ture
- 44 -
200~5~0
for more than 3 minutes. The coating was evaluated as in
Example 5 and test results obtained were shown in Table 3.
Titanium white 10.34 parts
tetrapod-like zinc oxide whiskers 60.03
dispersing acid
(Disparone 4200-20) 0.69
soy bean oil phthalic resin varnish 24.81
drier (lead naphthenate) 0.07
ethyl acetate 4.06
ComParatlve Example 6
The similar experiment as stated in Example 11 was
repeated, excepting substituting the following conventional
road marker white for the road marker white of Example 11.
Titanium white 15.00 parts
calcium carbonate 42.00
dispersing acid
(Disparone 4200-20) 1.00
soy bean oil phthalic resin varnish 36.00
drier (lead naphthenate) 0.10
ethyl acetate 5.90
Example 12
The similar experiment as stated in Example 11 was
repeated, excepting using the following acrylic road marker
yellow.
25 Titanium white 0.75 part
chrome yellow 8.32
tetrapod-like zinc oxide whiskers 47.06
- 45 -
2 Oa)L'~O
silica brick powder 10.00
aluminium stearate 0.76
acrylic resin 25.71
dibutyl phthalate 3.03
toluene 4-54
methyl alcohol 2.27
Comparative Exam~le 7
The similar experiment as stated in Example 11 was
repeated, excepting substituting the following conventional
acrylic road marker yellow for the marker of Example 11.
Titanium white 1.00 part
chrome yellow 11.00
calcium carbonate 30.00
silica brick powder 10.00
aluminium stearate 1.00
acrylic resin 34.00
dibutyl phthalate 4000
toluene 6.00
methyl alcohol 3.00
Exam~e 13
The same experiment as stated in Example 11 was repeated,
excepting using the following road marker blue. The coating
was evaluated as in Example 11 and -the test results were shown
in Table 3.
Titanium white 15.05 part
Cyanine blue 0.56
tetrapod-llke zinc oxide whiskers 11.51
- 46 -
20~ 54~
soy bean oil phthalic resin varnish 37.62
Dispersing acid (Disparone 4200~20) 1.41
silica brick powder 28.21
toluene 5.64
Comparative Example 8
The similar experiment as stated in Example 11 was
repeated, excepting substituting the following conventional
road marker blue for the marker of Example 11. The test
results are shown in Table 3.
Titanium white 16.00 part
Cyanine blue 0.60
calcium carbonate 5.90
soy bean oil phthalic resin varnish 40.00
Dispersing acid (Disparone 4200-20) 1.50
silica brick powder 30.00
toluene 6.00
ZO [)4~0
, _ . . ....................... _
Comp, Ex. _ Example
~-- --W '- ` 1--'-- 1 1
~ N ~ _ _
l r~ :~ zinc oxide whiskers
~ (D (1 ~h 1_ ~h 1-- ~h 1-- ~h 1-- ~h 1_ H~ I_ ~h l_ --
O (D O (D O (D O tD O (D O rD O (D
O ~ O ~ O ~ O ~ O :~ O ~ O ~
rl ~ r~ ~4 r~ ~ r~ ~4 rt ~Q r~ lQ r~ ~ c~
R- ~ ~ ~ R- ~ ~ r~ ~ r~ ~ ~ r~
1'- 1'- 1' 1' 1' 1' 1'
It p) ~ ~ ~ ~ ~ ~ u~
p, 3 3 3 3 3 3 ~ ,... o
/1) : (D tD (D (D (3 tl) N X
(D r~ r~ r~ r~ r~ r~ r~ ~
O it ~t ~ ~ ~ ~ ~ (D
~ O O O O ~ ~ Ul
.~ . . . ~ . ~ ~ O ~ o ~ O ~ o
3 o ~ ~ ~ ~ ? ~ ~ ? ? ~ ~ ? ~
o ~ _, ~ o ~ o ~ u, ~ o
. _~ ~no u-o o o ~ o ~ o ~ o
3 3 3 3 3 3 3 3 3 3 3 3 3 3
_ ~ _ ~ _ ~ ~ ~ _ ,
~ r
~ ~ ~ ~ ~ ~ ~ ~ ~ O ~
3 3 3 3 3 3 3 3 3 ~ r~ p)
rD~ (D
_ .._ . _ ._ _ ._ u~
D x x O (~ (~) (~) ~) (~)
. _ . _ _ _ _ ~".
O (~) O (~) O O ~) (~) ~ r~
r~ (D
_ _ ._----_ .._ ~0
D x x O O (~) O ~) O ~ ~h ~
r~
_ , . ._ - ._ . _ 3
~g ~
O X X O O (~) O (~) (~) I~ r~ O
__ _ _ _ _ rt
_ .. _ _.
-- ~8 --
.
200~L54~)
~, . ~, ~ ~ ~~ ~ _ .._ h~
xo X Xo X X3 X
~ _ ~ ~ _
l S O N _ S O N S O N _
O ~ O ~ ~) ~ ~'
~ 3 ~ 3 ~ 3 N X
? ? l o ~ o
_ ._ :~ ..__ ~... r _ (D
3 3 3 3 3 3 n ~u o
_ _ _ .__
D O ~> O D O c
_ . _ ~. .. . u
x o x o x (~) I @~
_ _ __ rt~l
I On
D O x O D O ~t~
kt~
. _ _ _ ~u n rt
O O O ~ O ~ X~
-- 49 --
2~ 5~Q
In Table 3, the test results were evaluated by the following
criteria;
Durability: Taber Tester 500g load, 300 times rotation
(JIS-K 5665)
~ .... less than 20mg abrasion loss
O ~-~ 20~ 5Omg
... 50~ 80mg
X ~ more than 80mg
Weather resistance:
~ .... no cracks on coated road after 12 months
O .... small cracks on coated road after 12 months
X ~ large cracks on coated road after 12 months
Visual cognition at dark time: object at 1Om ahead
~ ... clearly detectable
0 -. detectable
... dimly detectable
X ~ undetected
Examples of abrasive putty composition:
Exam ~
Unsaturated polyester varnish
Polyset 171~ (trademark of Hidachi Kasei) 35 parts
talc 50
tetrapod-like zinc oxide whiskers 5
dimethylaniline 2
styrene monomer 7
To the abovementioned putty composition, were added 2 parts
- 50 -
2~0~5~(~
of 50% benzoyl peroxide paste and mixed well. Thus obtained
putty was applied on 0.8mm polished steel plate and after
elapsing 60 mir.utes, the coating was subjected to wet sanding
with a #180 sand paper. At that time, clogging of abrasive
paper and spatule workability were evaluated.
The test results are shown in Table 4.
Comparative Example 9
The similar experiment as stated in Example 14 was
repeated, excepting substituting commercialized zinc white for
the tetrapod-like zinc oxide whiskers.
Comparative Ex mple 10
The sauce experiment as stated in Example 14 was
repeatedl excepting using 0.5 part of tetrapod-like zinc oxide
whiskers.
~able 4
. . _ _
¦Ex. CG~ ~
thicker coatability O X X
grinding property
(clo~a~ ~ no Yes no
O -- no sagging
X .... sagging
2O~)L~5~3
Examples of curing acceleration catalyst:
Example 15
20 parts of 25% lead naphthenate were dissolved in 200
parts of toluene and to this, 20 parts of -tetrapod-like zinc
oxide whiskers were added and the mixture was stirred for 15
minutes. After elapsing further 10 minutes, toluene was
removed off under reduced pressure to obtain the present
catalyst. 210 parts of Cyanamide helgon under coat paint
(oxidative polymerization type, oily anti-rusting paint,
manufactured by Nippon Paint Co., Ltd.~ were added with 20.5
parts of the abovementioned catalyst.
Comparative Example 11
To 210 parts of the same anti-rusting paint as used in
Example 15, 2.0 parts of lead naphthenate were added as
catalyst.
Each coating composition obtained in Example 15 and
Comparative Example 11 was applied on both 150mmx70mmxO.8mm
satin finish steel plate and glass plate so as to give a dry
film thickness of 100/~. The coating conditions were
20 evaluated af-ter s-tanding at 20C for 4 hours and 64 hours.
Test methods used and evaluation standard:
Surface drying;
The coating was pressed by finger and finger mark on the
coating and paint adhesion to finger were measured.
25 0 ..... no finger mark and no paint adhesion
........... finger mark but no paint adhesion
X finger mark and paint adhesion
- 52 -
2~ 5~
Curing property; finger was pressed on coating on glass plate
and crosswisely moved according to JIS-K-5400.
O ..... no coating sliding
~ ..... slightly side but no coating break out
X ..... slide and break
Table 5
_ ._ _ ._
Exampl e 15 _ Comp. E x. 11
Surface Curing Surface Curing
dr in dr in
Y q Y g
after 4 hours ~ ~ ~ X
_ __ .. _
. after 69 hours _ O O
- 53 -
