U.S. patent application number 11/564811 was filed with the patent office on 2007-05-03 for coated article, coating liquid composition, and method for producing coated article.
This patent application is currently assigned to NIPPON SHEET GLASS CO., LTD.. Invention is credited to Kazutaka Kamitani.
Application Number | 20070100066 11/564811 |
Document ID | / |
Family ID | 18937232 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070100066 |
Kind Code |
A1 |
Kamitani; Kazutaka |
May 3, 2007 |
COATED ARTICLE, COATING LIQUID COMPOSITION, AND METHOD FOR
PRODUCING COATED ARTICLE
Abstract
The invention is an coated article composed of a substrate and
an organic-inorganic composite film, which is coated on the
substrate and has an oxide of a cation atom capable of forming an
oxide network coated on the surface of the substrate, and the same
has a part of oxygen of the oxide substituted by an organic group,
wherein the organic-inorganic composite film includes alkali metal
oxides at a ratio of 0.1 through 30% of the total number of the
alkali metal atoms and the cation atoms expressed in terms of the
number of alkali metal atoms, and the article coated with a
high-performance organic-inorganic composite film, is able to
withstand outdoor uses and has high hardness.
Inventors: |
Kamitani; Kazutaka; (Osaka,
JP) |
Correspondence
Address: |
INTELLECTUAL PROPERTY LAW GROUP LLP
12 SOUTH FIRST STREET
SUITE 1205
SAN JOSE
CA
95113
US
|
Assignee: |
NIPPON SHEET GLASS CO.,
LTD.
7-28, Kitahama 4-chome, Chuo-ku
Osaka
JP
541-0041
|
Family ID: |
18937232 |
Appl. No.: |
11/564811 |
Filed: |
November 29, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10472289 |
Sep 20, 2003 |
7160626 |
|
|
PCT/JP02/02709 |
Mar 20, 2002 |
|
|
|
11564811 |
Nov 29, 2006 |
|
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|
Current U.S.
Class: |
524/588 ;
428/447; 525/474 |
Current CPC
Class: |
C03C 17/009 20130101;
Y10T 428/31663 20150401; C03C 17/30 20130101; Y10T 428/3154
20150401; C09D 183/08 20130101; C09D 4/00 20130101; C09D 183/14
20130101; C09D 4/00 20130101; C08G 77/00 20130101; C09D 4/00
20130101; C08G 77/04 20130101 |
Class at
Publication: |
524/588 ;
525/474; 428/447 |
International
Class: |
C08L 83/00 20060101
C08L083/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 21, 2001 |
JP |
2001-81067 |
Claims
1. A composition for coating, including: (a) a hydrolyzable and
condensation-polymerizable organic metal compound having an organic
group of nonhydrolyzability; (b) an acid; (c) an alkali metal
compound; and at least one of (d) a completely
condensation-polymerizable or
hydrolyzable/condensation-polymerizable compound and (e) an
alkaline earth metal compound.
2. The composition for coating as set forth in claim 1, wherein the
number of alkali metal atoms of said (c) constituent is 0.1 through
30% with respect to the total number of cation atoms (excluding
cation atoms of organic groups).
3. The composition for coating as set forth in claim 1, wherein the
number of cation atoms, excluding those contained within the
organic groups, of said (d) constituent is 0 through 99.8% with
respect to the total number of cation atoms (excluding cation atoms
of organic groups).
4. The composition for coating as set forth in claim 1, wherein the
number of alkaline earth metal atoms of said (e) constituent is 0.1
through 30% with respect to the total number of cation atoms
(excluding cation atoms of organic groups).
5. The composition for coating as set forth in claim 1, wherein,
with respect to the total number of cation atoms (excluding cation
atoms of organic groups) , the number of cation atoms, excluding
cation atoms contained within the organic groups, of said (a)
constituent is 0.1 through 99.8%; the number of alkali metal atoms
of said (c) constituents is 0.1 through 30%; the number of cation
atoms, excluding cation atoms contained within the organic groups,
of said (d) constituent is 0 through 99.7%; and the number of
alkaline earth metal atoms of said (e) constituent is 0.1 through
30%; and said (b) constituent is set to a normality of 0.001
through 3, and water is included at a ratio of 0 through 5% by
weight.
6. The composition for coating as set forth in claim 1, including a
solvent whose boiling point is 150.degree. C. or less at
atmospheric pressure.
7. The composition for coating as set forth in claim 6, wherein
said solvent is alcohol.
8. The composition for coating as set forth in claim 1, wherein
said (a) constituent is trialkoxysilane including a fluoroalkyl
group.
9. A method for producing a coated article, where in a composition
for coating described in claim 1 is coated and dried on a surface
of a substrate.
10. The method for producing a coated article, as set forth in
claim 9, wherein said drying is carried out at room
temperature.
11. The method for producing a coated article, as set forth in
claim 9, wherein said drying is carried out in an atmosphere whose
relative humidity is 40% or less.
12. The method for producing a coated article, as set forth in
claim 9, further comprising heating carried out at a temperature
which is higher than a room temperature but equal to or less than
300.degree. C. after said drying.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of U.S. application Ser. No.
10/472,289, filed on Sep. 20, 2003, which is hereby incorporated
herein by reference. application Ser. No. 10/472,289 is a U.S.
national phase application of International Application PCT/JPO
2/02709, with an international filing date of Mar. 20, 2002, and
further claims priority to Japan Application no. 2001-81067, filed
in Japan on Mar. 21, 2001, all of which are hereby incorporated by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an article coated with an
organic-inorganic composite film, which is formed on the surface of
a substrate such as glass, ceramic, plastic or metal, a composition
for coating an organic-inorganic composite film, and a method for
producing a coated article.
BACKGROUND OF THE INVENTION
[0003] Such a technology has been known, by which the surface of a
substrate is improved by providing an organic-inorganic composite
film having an inorganic oxide and an organic group on the surface
of glass and other matrices.
[0004] By coating a solution, in which silicon alkoxide,
substituted silicon alkoxide having a part of alkoxyl group
substituted by fluoroalkyl group, alcohol, water and acid (or a
base) are blended, on the surface of a glass substrate and burning
the same, glass having an organic-inorganic composite film having
water repellency coated thereon has been disclosed in Japanese
Unexamined Patent Application No. H4-338137.
[0005] An organic-inorganic composite film coated article having
water repellency, which is treated by a composition in which a
mixture of perfluoroalkylalkylsilane and completely hydrolyzable
silane (for example, tetrachlorosilane) is dissolved in a solvent,
preferably a non-water based solvent, has been known in Japanese
Unexamined Patent Application No. H8-239653.
[0006] An organic-inorganic composite film coated article having
water repellency, which is treated by a composition in which a
compound containing a chlorosilyl group and a silane compound
containing a fluoroalkyl group are dissolved in an alcohol-based
solvent has been disclosed in Japanese Unexamined Patent
Application No. H11-71682.
[0007] An organic-inorganic composite film in these technologies is
produced by a so-called sol-gel method in which a solvent including
a hydrolyzable silane compound and a silane compound having water
repellent group are coated on a substrate and dried thereon. In the
sol-gel method, since the solvent evaporation is progressed inline
with formation of an oxide bonding, remarkably fine pores exist in
a film when the temperature is 400.degree. C. or less, and hardness
of the film is not high. In order to remove the pores and to
increase the hardness of the film, burning thereof at a temperature
of 500 through 600.degree. C. is indispensable. However, an organic
group such as a water repellent group contributing to improvement
of the surface is decomposed at such a temperature. Therefore, in
the above-described technologies, drying and hardening of the film
are carried out at 250.degree. C. or less. The organic-inorganic
composite film thus obtained does not become a film having high
hardness as in oxides and ceramics that are obtained by, for
example, a melting method although the obtained organic-inorganic
composite film has oxides as the main compounds.
[0008] For example, where such an article coated with an
organic-inorganic composition film is used outdoors, the article is
exposed to such situations where sand is blown there onto, and the
film surface is easily impaired, resulting in a loss of the
improved characteristics. Also, by wiping off the surface thereof
to remove adhered dust, soil and sand, the film may be impaired and
peeled off. Further, even in a case where no dust is adhered, minor
damage occurs on the surface due to friction between a cloth made
of hard fabric, a brush, etc., (for example, wiping off the window
glass of a vehicle by a wiper, etc.,), wherein this damage fosters
deterioration in the characteristics.
[0009] The present invention was developed in view of the
above-described and other problems, and it is therefore an article
of the invention to provide an article coated with an
organic-inorganic composite film having high hardness which
withstands outdoor uses, water repellency and/or other functional
properties, and a coating liquid composition for producing this
coated article, and a method for producing the coated article with
excellent productivity.
SUMMARY OF THE INVENTION
[0010] The present inventor discovered that the hardness of an
organic-inorganic composite film is increased in epoch-making
proportions by providing alkali metal ions into an
organic-inorganic composite film on the basis of the results of
repeated research in order to solve the above-described object.
[0011] That is, the invention brings about a coated article
composed of a substrate and an organic-inorganic composite film,
which is coated on the surface of said substrate, and has an oxide
of a cation atom capable of forming an oxide network, and having a
part of oxygen of said oxide substituted by an organic group,
wherein said organic-inorganic composite film includes alkali metal
oxides at a ratio of 0.1 through 30% of the total number of said
alkali metal atoms and said cation atoms expressed in terms of the
number of said alkali metal atoms.
[0012] Generally, when forming an oxide film by a sol-gel method,
there are many cases where metal alkoxide, for example, alkoxide of
silicon (Si) is used as a starting material. In the sol-gel method,
since evaporation of a solvent is promoted in line with formation
of a metal by a dehydrating condensation action, for example,
bonding (siloxane bonding) of silicon (Si) and oxygen (O), a porous
silica film, which contains fine pores therein, is produced. The
bonding of silicon with oxygen is covalent, wherein as siloxane
bonding forms a three-dimensional structure to some degree in the
stage of evaporation of a solvent since silicon is bonded with
oxygen with large bonding energy, the structure thereof is
suppressed from contracting even if a dehydrating condensation
action is fostered thereafter, and portions where a solvent,
alcohol generated by a hydrolysis reaction, and water generated by
a dehydrating condensation reaction are evaporated remain as fine
pores. In the fine pores, a silanol group, an alkoxyl group, water
or alcohol exists. The hardness of the porous silica film is not
very high because of its porous structure. Where the film is heated
at a temperature of 500.degree. C. or more, fine pores of the film
become extinct, and the film is turned into a non-porous silica
film which will have a high hardness. However, since an organic
group having water repellency such as, for example, a fluoroalkyl
group is decomposed at this heating temperature, fine pores of the
film rarely become extinct when the heating temperature of the film
is a temperature (for example, 300.degree. C. or less) such as an
organic group having water repellency is not decomposed, and the
hardness of the film does not become high.
[0013] In the invention, an alkali metal oxide is introduced into
an organic-inorganic composite film. Since an alkali metal is
intensive in terms of ionic characteristics, by dissolving an
alkali metal in a coating liquid for forming a film and causing the
same to coexist along with a hydrolyzable metal compound (for
example, silane compound) such as silicon alkoxide, the alkali
metal may exist in a solvent in a state of ions even in the stage
of evaporation of the solvent. Since the alkali metal (M) ions are
monovalent, these react with a metal hydroxyl group (for example,
silanol group), wherein if the metal is, for example, silicon (Si),
it is finally bonded with oxygen (O) in the film as shown by the
following structure (1), a bonding [O.sup.- +M] having a freer
directivity in bonding in comparison with a bonding of [Si--O--Si]
can be produced. Therefore, a structure of the organic-inorganic
composite film in which an alkali metal oxide is introduced becomes
more easily deformable due to heat than the structure of a film not
including any alkali metal oxide. As a result, according to the
invention, the structure is deformed by drying or heating at a
lower temperature than the decomposing temperature (250 through
300.degree. C.) of an organic group contained in the
organic-inorganic composite film, wherein a number of fine pores
become extinct and the film becomes denser. Therefore, a film
having a very high hardness can be brought about.
.ident.Si--O.sup.-+M (where M indicates an alkali metal) (1)
[0014] It is possible for an organic-inorganic composite film
according to the invention to be caused to include an alkaline
earth metal oxide. The alkaline earth metal is intensive in terms
of ionic characteristics as in the alkali metal. By causing the
composite film to include an alkaline earth metal oxide, it is
possible to increase the abrasion-resisting property of the film
without spoiling the low temperature hardening property by
introduction of an alkali metal. Although the organic-inorganic
composite film according to the invention includes an organic group
as described later, the organic group exists on the surface at a
higher density than in inner portion of the organic-inorganic
composite film. The density of the organic group of the film
surface is further heightened by doping of an alkaline earth metal
oxide. As a result, functions of the organic group can be further
increased. For example, where the organic group is, for example, a
water repellent group, the contact angle of the film is further
increased by doping of an alkaline earth metal oxide, wherein the
rolling property of water drops can be further improved.
[0015] In the invention, lithium (Li), sodium (Na), potassium (K),
rubidium (Rb) , cesium (Cs), and francium (Fr) may be used as the
above-described alkali metal. However, Li and Cs are preferably
used in view of easy procurement and high solubility with respect
to both water and alcohol. Also, calcium (Ca), magnesium (Mg),
strontium (Sr), barium (Ba), radium (Ra), and beryllium (Be) are
used as the above-described alkaline earth metal. However, Ca and
Mg are preferably used in view of easy procurement, high solubility
with respect to both water and alcohol, and no toxicity.
[0016] Where the content of an alkali metal oxide is very slight in
the organic-inorganic composite film, an effect of hardening at low
temperature cannot be obtained. To the contrary, where the content
thereof is too high, segregation may arise to cause the alkali
metal oxide to become non-uniform, whereby the hardness of the film
is lowered. Therefore, the content thereof is expressed in terms of
the number of alkali metal atoms, and is 0.1 through 30% of the
total number of cation atoms and alkali metal atoms, and the
above-described alkaline earth metal atoms described later
constituting an oxide that forms networks of an organic-inorganic
composite film, preferably 1 through 25%.
[0017] Where the content of an alkaline earth metal oxide is
excessive in the organic-inorganic composite film, the alkaline
earth metal oxide is segregated to become non-uniform, thereby
lowering the hardness of the film. Therefore, the content thereof
is expressed in terms of the number of alkaline earth metal atoms,
and is preferably 0 through 30% of the total number of cation atoms
that constitute network-forming inorganic oxides of the
organic-inorganic composite film, the above-described alkali metal
atoms and alkaline earth metal atoms, further preferably 0.1
through 30% thereof, and still further preferably 1 through 25%
thereof. However, the total of the contents of alkali metal oxides
and alkaline earth metal oxides is expressed in terms of the total
number of the above-described alkali metal atoms and alkaline earth
metal atoms, and is preferably 50% or less of the total number of
the above-described cation atoms, alkali metal atoms, and alkaline
earth metal atoms.
[0018] An organic-inorganic composite film according to the
invention includes oxides of cation atoms by which oxide networks
are formed. Silicon, titanium, zirconium, aluminum, germanium,
tantalum, tin, antimony, cerium, lanthanum, tungsten, indium, and
boron, etc., may be listed as the cation atoms. Among these
constituents, silicon maybe preferably used because condensates and
crystal are in comparison rarely produced in a film during forming
the same, and a film free from any crack can be easily
obtained.
[0019] An organic-inorganic composite film according to the
invention includes oxides of cation atoms by which oxide networks
are formed, in which a part of oxygen in the oxide is substituted
by an organic group. The organic group is not specially limited.
However, a monovalent organic group is preferable. For example, an
alkyl group such as, for example, a methyl group, ethyl group,
isopropyl group, etc., phenyl group, vinyl group, aminopropyl
group, acryl group, epoxy group, polyether group, and further a
fluoroalkyl group, chloroalkyl group, etc., in which a part or all
of hydrogen of a carbohydrate is substituted by fluorine or
chlorine, may be listed. Among these groups, for example, the alkyl
group and fluoroalkyl group provide the film with water repellency,
the methyl group provides the same with a low friction property,
and the aminopropyl group and polyether group provide the surface
thereof with hydrophilicity.
[0020] These organic groups exist in a state where, in an
organic-inorganic composite film, these are bonded with cation
atoms (for example, silicon atoms) of an inorganic oxide (for
example, SiO.sub.2) that forms the networks thereof. Where the
content of the organic groups is too slight, the organic groups do
not contribute to reforming the surface of a substrate, wherein the
film does not display appointed performance. Wherein the content
thereof is the excessive, the film strength is decreased.
Therefore, the content thereof is expressed in terms of the number
of organic groups, and is preferably 0.001 times or more but less
than 2 times the total number of cation atoms of an inorganic oxide
that forms the networks thereof, the above-described alkali metal
atoms, and alkaline earth metal atoms in an organic-inorganic
composite film. Further preferably, the content is 0.01 times
through one time. The organic group may be uniformly distributed in
the thickness direction of the film. However, it may be composed of
an inclined composition film whose density may change from the
boundary side with the substrate to the outer surface thereof. For
example, in order to cause the film to have water repellency, an
alkyl group and/or fluoroalkyl group in the film are contained so
that the number thereof becomes 50 through 100% of the total number
of the organic groups, wherein it is further preferable in that a
water repellent film having high durability performance is obtained
together with an increase in the hardness of the film.
[0021] Thus, according to the invention, by containing alkali metal
ions or alkali metal ions and alkaline earth metal ions, it is
possible to obtain a film having a high hardness that cannot be
obtained by prior arts, by drying or heating at a temperature lower
than the decomposing temperature of an organic group contributing
to reforming of the surface of a substrate. As a result, the
durability performance of organic-inorganic compound films can be
remarkably improved.
[0022] Such low temperature hardening performance is not impaired
even in a case where transition metal ions, etc., are introduced
into the film for the purpose of, for example, adding a feature of
controlling the refractive index of the film and controlling the
visible light transmissivity in addition to a reforming property
brought about by the organic groups. That is, by causing the
transition metal ions and alkali metal oxides (or both alkali metal
oxides and alkaline earth metal oxides) to coexist, which can
manifest the target feature, it is possible to obtain a
combined-function film that has very high hardness by drying and
heating at a temperature less than 300.degree. C. and can include a
reforming property by an organic group and a feature brought about
by the transition metal ions. It is possible to obtain an
organic-inorganic composite film colored by doping, for example,
cobalt oxide, iron oxide, nickel oxide, and copper oxide
thereto.
[0023] Further, organic molecules such as coloring pigments, etc.,
can be included in the above composite film as in the above.
However, it is preferable that the content of organic molecules
other than those included as the organic groups is 5% or less by
weight with respect to the film weight. If such organic molecules
are doped more than the above, low temperature hardening
performance may be lost.
[0024] If the film thickness is too thick, the film hardness
becomes liable to be lowered. If the same is too thin, no effect of
reforming the surface of a substrate can be obtained. Therefore,
the film thickness is preferably 5 through 200 nm, further
preferably 5 through 100 nm, and still further preferably 5through
50 nm.
[0025] Further, the invention pertains to a composition for
coating, including:
[0026] (a) an organic metal compound having an organic group of
nonhydrolyzability,
[0027] (b) an acid, and
[0028] (c) an alkali metal compound, and if necessary,
[0029] (d) a completely condensation-polymerizable or
hydrolyzable/condensation-polymerizable compound, and
[0030] (e) an alkaline earth metal compound.
[0031] It is preferable that the above-described constituent (a) is
contained so that the number of atoms excluding the organic group
is 0.1 through 99.8% with respect to the total number (However,
excluding cation atoms in the organic group. This is applicable to
the following description.) of cation atoms of the above-described
constituents (a), (c) , (d) and (e) . Further preferably, the
content ratio thereof is 1.0 through 90%. It is preferable that the
above-described constituent (c) is contained so that the number of
the alkali metal atoms becomes 0.1 through 30% with respect to the
total number of cation atoms excluding the organic groups of the
above-described constituents (a), (c), (d) and (e) . Further
preferably, the content ratio thereof is 1 through 25%. The
above-described constituent (d) is a constituent for strengthening
bonding between the film and a substrate. It is preferable that the
constituent (d) is contained so that the number of cation atoms
excluding the organic group becomes 0 through 99.7% with respect to
the total number of cation atoms excluding the organic groups of
the above-described constituents (a), (c), (d) and (e). Further
preferably, the content ratio thereof is 1 through 88%. And, it is
preferable that the above-described constituent (e) is contained so
that the number of alkali metal atoms becomes 0.1 through 30% with
respect to the total number of cation atoms excluding the organic
groups of the above-described constituents (a), (c), (d) and (e) .
Further preferably, the content ratio thereof is 1 through 25%.
[0032] In the invention, the constituent (d) is not requisite.
However, the constituent (d) may be dissolved in alcohol that is a
general solvent. A compound that is completely hydrolyzable and
condensation-polymerizable or a compound that is completely
condensation-polymerizable maybe widely used. That is, a compound
that is completely hydrolyzable and condensation-polymerizable is a
compound in which hydrolyzing groups are bonded to cation atoms,
and in which the number of hydrolyzing groups is equal to that of
cation atoms. Also, a compound that is completely
condensation-polymerizable is a compound in which hydroxyl groups
are bonded to cation atoms and in which the number of hydroxyl
groups is equal to that of cation atoms. For example, alkoxide,
hydroxide, chloride, nitride, etc., of cation atoms (silicon,
titanium, zirconium, aluminum, germanium, tantalum, gallium, tin,
antimony, cerium, lanthanum, tungsten, indium, scandium, yttrium,
boron, etc.,), which are able to form oxide networks, may be listed
as the above-described constituent (d). Where reaction is very
sensitive like alkoxide such as titanium, zirconium, aluminum,
boron, etc., and it is difficult to obtain a uniform solution with
only the same doped, these may be doped after turning the same into
chelate by .beta. diketone such as acetylacetone, etc. In a case of
compounds that are not soluble in alcohol but are soluble in water,
water maybe doped as necessary. In detail, as to the
above-described constituent (d), silicontetraalkoxide such as
tetramethoxysilane, tetraethoxysilane, etc., titantetraalkoxide
such as titantetraisopropoxide, titantetrabuthoxide, etc.,
zirconiumtetraalkoxide such as zirconiumtetraisopropoxide,
zirconiumtetraethoxide, zirconiumtetrabuthoxide, etc., and
compounds such as H.sub.3BO.sub.3, ZrOCl.sub.2,
ZrO(NO.sub.3).sub.2, AlCl.sub.3, GeCl.sub.4, TaCl.sub.5,
GaCl.sub.3, InCl.sub.3, ScCl.sub.3, YCl.sub.3, LaCl.sub.3,
CeCl.sub.3, Al(NO.sub.3).sub.3, Ga(NO.sub.3).sub.3,
In(NO.sub.3).sub.3, SbCl.sub.3, WCl.sub.6, Sc(NO.sub.3).sub.3,
Y(NO.sub.3).sub.3, La(NO.sub.3).sub.3, Ce(NO.sub.3).sub.3 may be
preferably used because these compounds have high solubility with
water and alcohol.
[0033] For example, chloride, nitrate, etc., of alkali metals
(lithium, sodium, potassium, rubidium, cesium, francium), which are
soluble in alcohol, may be used as an alkali metal compound that is
the above-described constituent (c) . In further detail, metal
compounds such as LiCl, NaCl, KCl, RbCl, CsCl, FrCl, etc., may be
preferably used since these compounds have high solubility with
water or alcohol.
[0034] An alkaline earth metal compound that is the above-described
constituent (e) is not requisite. However, for example, chloride,
nitrate, etc., of alkaline earth metals (beryllium, magnesium,
calcium, strontium, barium, radium) that can be soluble with
alcohol may be used as the constituent (e). In further detail,
metal compounds such as BeCl.sub.2, MgCl.sub.2, Mg(NO.sub.3).sub.2,
CaCl.sub.2, Ca(NO.sub.3).sub.2, SrCl.sub.2, BaCl.sub.2, RaCl.sub.2,
Ba(NO.sub.3).sub.2 may be preferably used since these compounds
have high solubility with water and alcohol.
[0035] As to organic metal compounds having a non-hydrolyzable
organic group that is the consituent (a) according to the
invention, for example, compounds in which a part of anion of metal
compounds of those described as the above-described constituent (d)
, that is, silicon, titanium, zirconium, aluminum, germanium,
tantulum, antimony, tin, cerium, lanthanum, tungsten, and indium is
substituted by a non-hydrolyzable organic group may be preferably
used. Either of these metals is a cation atom that is able to form
oxide networks. The non-hydrolyzable organic group is not specially
limited. However, alkyl groups such as a methyl group, ethyl group,
isopropyl group, etc., phenyl groups, vinyl groups, aminopropyl
groups, acryl groups, epoxy groups, and further fluoroalkyl groups,
chloroalkyl groups, etc., in which a part or all of hydrogen of a
hydrocarbon, is substituted, may be listed as non-hydrolyzable
organic groups. These organic groups remain in an organic-inorganic
composite film, and provide the film with various features such as
water repellency, a low friction property, and hydrophilicity. An
organic silicon compound having such a non-hydrolyzable organic
group can be obtained as a comparatively stable compound, wherein
these compounds are preferably employed.
[0036] For example, the following may be listed as silane compounds
having an alkyl group:
[0037] alkyl group-contained chlorosilane such as:
CH.sub.3(CH.sub.2).sub.18SiCl.sub.3,
CH.sub.3(CH.sub.2).sub.16SiCl.sub.3,
CH.sub.3(CH.sub.2).sub.2SiCl.sub.3, CH.sub.3CH.sub.2SiCl.sub.3,
(CH.sub.3CH.sub.2).sub.2SiCl.sub.2, (CH.sub.3CH.sub.2).sub.3SiCl,
CH.sub.3SiCl.sub.3, (CH.sub.3).sub.2SiCl.sub.2,
(CH.sub.3).sub.3SiCl
[0038] alkyl group-contained alkoxysilane such as:
CH.sub.3(CH.sub.2).sub.18Si(OCH.sub.3).sub.3,
CH.sub.3(CH.sub.2).sub.16Si(OCH.sub.3).sub.3,
CH.sub.3(CH.sub.2).sub.8Si (OCH.sub.3).sub.3,
CH.sub.3(CH.sub.2).sub.7Si (OCH.sub.3).sub.3,
CH.sub.3(CH.sub.2).sub.2Si(OCH.sub.3).sub.3,
CH.sub.3CH.sub.2Si(OCH.sub.3).sub.3,
(CH.sub.3CH.sub.2).sub.2Si(OCH.sub.3).sub.2,
(CH.sub.3CH.sub.2).sub.3SiOCH.sub.3, CH.sub.3Si(OCH.sub.3).sub.3,
(CH.sub.3).sub.2Si(OCH.sub.3).sub.2, (CH.sub.3).sub.3SiOCH.sub.3,
CH.sub.3(CH.sub.2).sub.18Si(OC.sub.2H.sub.5).sub.3,
CH.sub.3(CH.sub.2).sub.16Si(OC.sub.2H.sub.5) 3,
CH.sub.3(CH.sub.2).sub.8Si(OC.sub.2H.sub.5).sub.3,
CH.sub.3(CH.sub.2).sub.7Si(OC.sub.2H.sub.5).sub.3,
CH.sub.3(CH.sub.2).sub.2Si(OC.sub.2H.sub.5).sub.3,
CH.sub.3CH.sub.2Si(OC.sub.2H.sub.5).sub.3,
(CH.sub.3CH.sub.2).sub.2Si(OC.sub.2H.sub.5).sub.2,
(CH.sub.3CH.sub.2).sub.3SiOC.sub.2H.sub.5,
CH.sub.3Si(OC.sub.2H.sub.5).sub.3, (CH.sub.3).sub.2Si
(OC.sub.2H.sub.5).sub.2, (CH.sub.3).sub.3SiOC.sub.2H.sub.5,
[0039] end methoxylpolydimethylsiloxane such as
CH.sub.3O(Si(CH.sub.3).sub.2O).sub.nCH.sub.3, (herein, n is 2
through 2000), and end silanolpolydimethylsiloxane such as
HO(Si(CH.sub.3).sub.2O).sub.nH (herein, n is 2 through 2000), etc.,
The following may be listed as a silane compound having a
fluoroalkyl group:
[0040] fluoroalkyl group-contained trichlorosilane such as
CF.sub.3(CF.sub.2).sub.9(CH.sub.2).sub.2SiCl.sub.3,
CF.sub.3(CF.sub.2).sub.7 (CH.sub.2).sub.2SiCl.sub.3,
CF.sub.3(CF.sub.2).sub.5(CH.sub.2).sub.2SiCl.sub.3,
CF.sub.3(CF.sub.2).sub.3(CH.sub.2).sub.2SiCl.sub.3,
CF.sub.3CF.sub.2(CH.sub.2).sub.2SiCl.sub.3,
CF.sub.3(CH.sub.2).sub.2SiCl.sub.3 ; and
[0041] Fluoroalkyl group-contained trialkoxysilane such as
CF.sub.3(CF.sub.2).sub.9(CH.sub.2).sub.2Si(OCH.sub.3).sub.3,
CF.sub.3(CF.sub.2).sub.7(CH.sub.2).sub.2Si(OCH.sub.3).sub.3,
CF.sub.3(CF.sub.2).sub.5(CH.sub.2).sub.2Si(OCH.sub.3).sub.3,
CF.sub.3(CF.sub.2).sub.3(CH.sub.2).sub.2Si(OCH.sub.3).sub.3,
CF.sub.3CF.sub.2(CH.sub.2).sub.2Si(OCH.sub.3).sub.3,
CF.sub.3(CH.sub.2).sub.2Si(OCH.sub.3).sub.3.
[0042] By employing these fluoroalkyl group-contained silane
compounds, it is possible to render the surface of a substrate to
have water repellency. Further, where trichlorosilane,
trialkoxysilane, etc., that have a fluoroalkyl group including ten
or more fluorine atoms are used, the film can be concurrently
provided with excellent water repellency and durability features.
In particular,
CF.sub.3(CF.sub.2).sub.7(CH.sub.2).sub.2Si(OCH.sub.3).sub.3
(heptadecafluorodecyltrimethoxysilane) and
CF.sub.3(CF.sub.2).sub.7(CH.sub.2).sub.2SiCl.sub.3
(heptadecafluorodecyltrichlorosilane) may be preferably used.
[0043] Acid that is a constituent (b) of the coating composition
according to the invention is not specially limited. However, it is
preferable that those which hardly remain in the membrane during
drying can achieve a film having high hardness. For example,
hydrochloric acid, nitric acid, acetic acid, hydrofluoric acid,
formic acid, trifluoroacetic acid, etc., may be listed. Among
these, hydrochloric acid having a high degree of electrolytic
dissociation and volatility, which is comparatively easy to be
handled, is particularly preferable. It is preferable that the
above-described constituent (b) is contained at a normality of
0.001 through 3.
[0044] A solvent whose boiling point is 150.degree. C. or less at
atmospheric pressure may be widely used as a solvent for the
invention. For example, a hydrocarbon such as hexane, toluene, and
cyclohexane, halogenated hydrocarbon such as methyl chloride,
carbon tetrachloride, and trichloroethylene, ketone such as
acetone, methylethylketone, nitrogen-contained compound such as
dethyleamine, ester such as acetic ethyl, and alcohol, etc., may be
used. Among these, alcohol-based solvents may be preferably used.
For example, methanol, ethanol, 1-propanol, 2-propanol, buthyl
alcohol, amyl alcohol, etc., may be listed. Chain saturated
monovalent alcohol whose carbon number is 3 or less such as
methanol, ethanol, 1-propanol, and 2-propanol, may be preferably
used since the same has a large evaporation rate at normal
temperature.
[0045] The above-described alcohol may contain water at a ratio of
0% or more by weight but 50% or less by weight. The highest-quality
alcohol that is available on the market usually contains water at
0.2% or more by weight. The alcohol may be preferably used for the
invention without any processing such as a dehdyrating process that
results in an increase in costs. Also, when doping metal materials,
a metal compound be dissovled in water and doped in advance, or
other solvents may be doped in order to control the drying rate and
viscosity of the liquid. At this time, it is preferable that the
amount of the above-described chain saturated monovalent alcohol
whose carbon number is 3 or less is equal to or exceeds 10% by
weight with respect to the amount of a solvent. If the amount is
less than the above, there may be a case where no uniform and
transparent film can be obtained.
[0046] In a coating composition (coating solution) containing the
above constituents (a) through (e), with respect to the
above-described constituents (a) and (d), a hydrolyzing reaction
and a dehydrating condensation reaction advance, dependent upon the
catalyst constituent (b) and slight water in the solvent. Wherein a
great deal of water exists in the coating solution, the hydrolyzing
reaction and dehydratating condensation reaction of the
above-described constituents (a) and (d) are fostered, the pot life
of the coating liquid becomes short, and the film thickness may
likely become uneven when being dried after the coating liquid is
sprayed. Therefore, in order to lengthen the pot life of the
solution and eliminate unevenness of the film thickness when being
dried after coating, it is preferable that the concentration of
water in the coating solution is made as slight as possible.
Alcohol that is available on the market usually contains water of
0.2% or more by weight. The water content is sufficient in the
invention. However, where water is further doped, it is preferable
that the concentration of water is 0 through 5% by weight with
respect to the coating solution, and 0 through 2% by weight is
further preferable. Even if the concentration of water in the
coating solution is zero, there is no case where the hydrolyzing
reaction is hindered since a coating film after being coated on a
substrate can absorb water or humidity in the air.
[0047] The coating method for the invention is not specially
limited. However, for example, dip coating, flow coating, curtain
coating, spin coating, spray coating, bar coating, roll coating,
brush coating, etc., may be listed.
[0048] Coating in the invention is carried out at an ambient
temperature ranging from 0 through 40.degree. C., for example, at
room temperature, with relative humidity of 40% or less. Drying
after coating is carried out at an ambient temperature ranging from
0 through 40.degree. C. with relative humidity of 40% or less for
10 seconds through 20 minutes at room temperature. Thereafter, as
necessary, heating may be carried out at a temperature, which is
higher than room temperature but including or less than 300.degree.
C., for 30 seconds through 10 minutes. Therefore, it is possible to
obtain a film of high hardness, which has peculiar functionality as
organic groups, without decomposing the organic groups that
constitute the film. If heating is carried out at a temperature of
300.degree. C. or less, which is higher than room temperature after
the above-described coating is completed where organic groups
having functionality are water repellent groups, a water drops
rolling property and an ultraviolet ray resisting property of a
film obtained may be likely to be lowered. Therefore, it is
preferable that drying is carried out at room temperature after
coating is completed.
[0049] Various types of plate-like or bar-like transparent or
non-transparent materials of glass, ceramic, plastic or metal,
etc., may be listed as a substrate for the invention. Where there
are a few hydrophilic groups on the surface of the substrate, it is
preferable that surface treatment is carried out after the surface
is treated to become hydrophilic by processing the same in a plasma
or corona atmosphere including oxygen in advance or by irradiating
an ultraviolet ray, whose wavelength is around 200 through 300 nm,
in an atmosphere including oxygen.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0050] A detailed description is given of embodiments with
reference to the following examples.
Embodiment 1
[0051] Heptadecafluorodecyltrimethoxysilane
(CF.sub.3(CF.sub.2).sub.7(CH.sub.2).sub.2Si(OCH.sub.3).sub.3
produced by Shinetsu Silicone, hereinafter called "FAS") of 0.2
grams, tetraethoxysilane (Si(OCH.sub.2CH.sub.3).sub.4 produced by
Shinetsu Silicone, hereinafter called "TEOS") of 0.6 grams, lithium
chloride of 0.00947 grams, and concentrated hydrochloric acid (35%
by weight) of 2 grams are doped to ethanol (whose water content is
0.35% by weight) of 999.19 grams while agitating the same, and FAS
and TEOS are hydrolyzed to obtain a coating solution. Respective
contents of FAS, TEOS and lithium chloride, which are metal
compounds in the coating solution, are shown in Table 1 in terms of
mole fraction where the total amount thereof is assumed to be 100
mol %. The coating solution is coated by a flow coating method on a
washed glass substrate (3.4 mm.times.150 mm.times.150 mm) of a soda
lime silicate glass composition at room temperature (20.degree. C.)
with relative humidity of 30%, and is dried at room temperature
(20.degree. C.) with relative humidity of 30% for approx. one
minute, whereby the organic-inorganic composite film-coated glass
plate on which a water repellent film of a thickness of approx. 40
nm is coated is obtained. Mole fraction of alkali metal atoms with
respect to the total of cation atoms (silicon) and alkali metal
atoms (lithium), which constitute an inorganic oxide of the
obtained organic-inorganic composite film is as shown in Table
1.
[0052] In connection with the obtained organic-inorganic composite
film-coated glass plate having a water repellent feature, a water
contact angle was measured by using a water drop having a weight of
2 mg, by a contact angle gauge (CA-DT, produced by Kyowa Surfactant
Chemistry, K.K) as a static contact angle. It is indicated that the
larger the contact angle is, the more excellent the static water
repellent feature is. Also, as to a scale showing performance
(water drops rolling property) of a water drop rolling on the
surface of coated glass having water repellency, a tilt angle
(critical tilt angle) of a glass plate was measured at a moment
when a water drop of 50 .mu.l placed on the surface of the coated
glass plate disposed horizontally began rolling when gradually
inclining the glass plate. The smaller the critical tilt angle is,
the more excellent the dynamic water repellency feature is, wherein
precipitation (raindrops) adhered to a front glass window of a
running vehicle becomes easily splashed, and visibility of a driver
is not hindered.
[0053] Further, with respect to evaluation of the hardness of a
film, abrasion was carried out 100 times at a weight of 250 grams
on an organic-inorganic composite film-coated glass plate by using
a taber abrasion test, which is available on the market, and the
static contact angle in regard to a water drop of 2 mg described
above was measured.
[0054] Contact angles of an organic-inorganic composite film having
water repellency and contact angles before and after the taber
abrasion test are shown in Table 2. With respect to the obtained
film, the contact angle was large to be 108 degrees before the
taber test, and was 90 degrees after the taber test. A decrease in
the contact angle was slight before and after the taber test, and
the film hardness was very high. Also, the water drop rolling
property was 8 degrees in terms of the critical tilt angle.
[0055] If contact angles of an organic-inorganic composite film
having water repellency and contact angles before and after the
taber abrasioning test is not so changed, it is said that hardness
and durability of the organic-inorganic composite film of the
invention are very high.
Embodiments 2 through 10
[0056] Organic-inorganic composite film-coated glass having water
repellency was obtained as in Embodiment 1, excepting that
materials of metal compounds and the constituent ratios thereof in
the coating solution of Embodiment 1 were modified as in Table 1.
Thickness of the organic-inorganic composite films was in a range
from 5 through 50 nm in any one of Embodiments 2 through 10. Cation
composition of the obtained film, that is, mole fraction of alkali
metal atoms or alkaline earth metal atoms with respect to the total
of cation atoms, alkali metal atoms, and alkaline earth metal
atoms, which constitute inorganic oxide networks of the
organic-inorganic composite film was as in Table 1. Results
measured as in Embodiment 1 are shown in Table 2.
[0057] Either of the obtained films had high hardness, wherein the
contact angle thereof was large before the taber test and a
lowering in the contact angle was slight after the taber test.
Where Embodiment 3 in which no alkaline earth metal oxide is
contained is compared with Embodiment 4 in which a part of alkali
metal oxides in Embodiment 3 was substituted with alkaline earth
metal oxides, it is found that Embodiment 4 is superior to
Embodiment 3 in view of a abrasion resisting property and a water
drop rolling property.
COMPARATIVE EXAMPLES 1 THROUGH 5
[0058] Organic-inorganic composite film-coated glass having water
repellency was obtained as in Embodiment 1, excepting that
materials of metal compounds and the amounts of doping thereof in
the coating solution of Embodiment 1 were modified as in Table 1.
Composition of cation of the obtained film was as in Table 1.
Results measured as in Embodiment 1 are shown in Table 2.
[0059] Although the obtained film had a large contact angle before
the taber test, a lowering in the contact angle was increased after
the taber test, wherein almost no water repellency is left over,
and the film hardness was very low.
Embodiment 11
[0060] End silanolpolydimethylsiloxane (produced by Gelest, Weight
average molecular weight: 4200) was used as a metal compound having
a non-reacting organic group in the coating solution for Embodiment
1, and organic/inorganic composite film-coated glass having a low
friction feature was obtained as in Embodiment 1, excepting that
the material of the metal compound and the amount of doping thereof
were, respectively, changed as in Table 1. However, the constituent
ratio and respective mole fractions are expressed in terms of mole
numbers in which the content of the end silanolpolydimethylsiloxane
(Weight average molecular weight: 4200) is converted to SiO.sub.2.
The composition of cation of the obtained film was as shown in
Table 1.
[0061] Also, dynamic friction coefficients of the paper and film
surface were measured by using a surface measuring instrument
(HEIDON-14) produced by Shinto Kagaku, Ltd. It was found that the
surface having very small friction resistance, whose friction
coefficient is 0.1 or less, was obtained. The obtained film was a
film having high hardness, whose contact angle before the taber
test is large and a lowering in the contact angle after the taber
test is small, as shown in Table 2. Further, when the friction
coefficient was measured after the taber test, the friction
coefficient thereof was a very small value to be 0.1 or less as
before the taber test.
COMPARATIVE EXAMPLE 6
[0062] The amounts of use of LiCl and
MgCl.sub.2.quadrature.6H.sub.2O, which were used in the coating
solution for Embodiment 9, were made into zero, excepting that DMS
and TEOS were changed as shown in Table 1 and organic-inorganic
composite film-coated glass having a low friction feature was
obtained as in Embodiment 9. Although the obtained film had a large
contact angle before the taber test, a lowering in the contact
angle after the taber test was large. Almost all of the water
repellency was lost, and film hardness was low.
[0063] Also, dynamic friction coefficients of the paper and film
surface were measured before and after the taber test as in
Embodiment 9. The friction coefficient after the taber test was
increased to 0.5 although a surface having very low friction
resistance, whose friction coefficient before the taber test was
0.1 or less, was obtained. TABLE-US-00001 TABLE 1 Alkaline
Constituent Alkali metals earth metals Materials of ratio Content
Content metal compounds (Molar ratio) Type (mol %) Type (mol %)
Embodiment 1 FAS/TEOS/LiCl 10/83/7 Li 7 -- 0 2 FAS/TEOS/CsCl 5/87/8
Cs 8 -- 0 3 FAS/TEOS/LiCl 10/80/10 Li 10 -- 0 4
FAS/TEOS/LiCl/MgCl.sub.2.quadrature.6H.sub.2O 10/80/7/3 Li 7 Mg 3 5
FAS/LiCl/CaCl.sub.2.quadrature.2H.sub.2O 98/1/1 Li 1 Ca 1 6
FAS/CsCl/MgCl.sub.2.quadrature.6H.sub.2O 50/25/25 Cs 25 Mg 25 7
FAS/TEOS/CsCl/CaCl.sub.2.quadrature.6H.sub.2O 10/88/1/1 Cs 1 Ca 1 8
FAS/ZrOCl.sub.2.quadrature.8H.sub.2O/KCl 10/80/10 K 10 -- 0 9
FAS/H.sub.3BO.sub.3/NaCl/CaCl.sub.2.quadrature.2H.sub.2O 50/40/5/5
Na 5 Ca 5 10 FAS/LiCl 95/5 Li 5 -- 0 11
DMS/TEOS/LiCl/MgCl.sub.2.quadrature.6H.sub.2O 1/89/7/3 Li 7 Mg 3
Comparative examples 1 FAS 100 -- 0 -- 0 2 FAS/TEOS 10/90 -- 0 -- 0
3 FAS/TEOS/LiCl 10/50/40 Li 40 -- 0 4
FAS/TEOS/CsCl/MgCl.sub.2.quadrature.6H.sub.2O 5/15/40/40 Cs 40 Mg
40 5 FAS/TEOS/CaCl.sub.2.quadrature.6H.sub.2O 10/80/10 -- 0 Ca 10 6
DMS/TEOS 1/99 -- 0 -- 0 *FAS:
F(CF.sub.2).sub.8(CH.sub.2).sub.2Si(OCH.sub.3).sub.3, TEOS:
Si(OC.sub.2H.sub.5).sub.4, DMS: End silanolpolydimethylsiloxane
(Weight average molecular weight: 4200)
[0064] TABLE-US-00002 TABLE 2 Contact angle Contact angle (deg.)
before (deg.) after Critical tilt abration test abration test angle
(deg.) Embodiment 1 108 90 8 Embodiment 2 108 95 7 Embodiment 3 108
85 6 Embodiment 4 108 89 4 Embodiment 5 108 91 6 Embodiment 6 108
96 6 Embodiment 7 108 98 5 Embodiment 8 108 92 8 Embodiment 9 108
90 8 Embodiment 10 107 88 9 Embodiment 11 100 88 4 Comparative 108
60 10 Example 1 Comparative 108 73 9 Example 2 Comparative 108 75
10 Example 3 Comparative 108 78 12 Example 4 Comparative 108 76 13
Example 5 Comparative 100 78 10 Example 6
INDUSTRIAL APPLICABILITY
[0065] As described above, according to the invention, by
containing alkali metal ions in an organic-inorganic composite
film, it is possible to obtain an organic-inorganic composite film
whose hardness is increased in epoch-making proportions. Also, by
containing alkaline earth metal ions in an organic/inogranic
composite film together with the alkali metal ions, it is possible
to further improve the functionality of the organic groups along
with increasing the hardness of the film.
* * * * *