U.S. patent application number 10/404117 was filed with the patent office on 2003-11-06 for coating process and silicon-containing liquid composition.
This patent application is currently assigned to Dainippon Shikizai Kougyo Co. , Ltd. Mitsubishi Chemical Corporation. Invention is credited to Fukamachi, Wakako, Honma, Naoki, Kobayashi, Katsuo, Matsuzoe, Nobuyuki, Sawai, Takeshi.
Application Number | 20030207991 10/404117 |
Document ID | / |
Family ID | 25537672 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030207991 |
Kind Code |
A1 |
Kobayashi, Katsuo ; et
al. |
November 6, 2003 |
Coating process and silicon-containing liquid composition
Abstract
The present invention relates to a silicon-containing liquid
composition comprising (A) 100 parts by weight of an
organosilicate, calculated as SiO.sub.2, (B) 0.1 to 10 parts by
weight of a catalyst, (C) 100 to 50,000 parts by weight of water,
and (D) 100 to 50,000 parts by weight of a solvent, a weight ratio
of the water (C) to the solvent (D) being in the range of 30:70 to
80:20.
Inventors: |
Kobayashi, Katsuo;
(Ibaraki-ken, JP) ; Fukamachi, Wakako;
(Ibaraki-ken, JP) ; Honma, Naoki; (Tokyo, JP)
; Matsuzoe, Nobuyuki; (Kitakyushu-shi, JP) ;
Sawai, Takeshi; (Kitakyushu-shi, JP) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
1100 N GLEBE ROAD
8TH FLOOR
ARLINGTON
VA
22201-4714
US
|
Assignee: |
Mitsubishi Chemical Corporation;
Dainippon Shikizai Kougyo Co. , Ltd.
|
Family ID: |
25537672 |
Appl. No.: |
10/404117 |
Filed: |
April 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10404117 |
Apr 2, 2003 |
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09991875 |
Nov 26, 2001 |
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6599976 |
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Current U.S.
Class: |
524/837 |
Current CPC
Class: |
C09D 183/02 20130101;
C08L 83/02 20130101 |
Class at
Publication: |
524/837 |
International
Class: |
C08L 083/00 |
Claims
What is claimed is:
1. A silicon-containing liquid composition comprising (A) 100 parts
by weight of an organosilicate, calculated as SiO.sub.2, (B) 0.1 to
10 parts by weight of a catalyst, (C) 100 to 50,000 parts by weight
of water, and (D) 100 to 50,000 parts by weight of a solvent, a
weight ratio of the water (C) to the solvent (D) being in the range
of 30:70 to 80:20.
2. A silicon-containing liquid composition according to claim 1,
having a hydrolysis percentage of 1,000 to 90,000%.
3. A silicon-containing liquid composition according to claim 1,
further comprising (E) at least one additive selected from the
group consisting of pigments, fillers and paint additives.
4. A silicon-containing liquid composition according to claim 1,
wherein the organosilicate (A) is represented by the general
formula: SiO.sub.x(OR).sub.y wherein x is a number of 0 to 1.2, and
y is a number of 1.4 to 4 with the proviso that (2x+y) is 4; and R
is C.sub.1 to C.sub.4 alkyl.
5. A silicon-containing liquid composition according to claim 1,
wherein the organosilicate (A) is methyl silicate.
6. A coating process comprising: coating a surface of a structure
with the silicon-containing liquid composition as defined in claim
1 so as to prevent the surface of the structure from being
contaminated.
7. A coating process comprising: coating a surface of an inorganic
structure with the silicon-containing liquid composition as defined
in claim 1 so as to prevent the surface of the inorganic structure
from being contaminated.
8. A coating process comprising: forming the silicon-containing
liquid composition as defined in claim 1 into an aerosol; and
spray-coating the aerosol onto a surface of a structure.
9. A coating process comprising: wipe-coating a surface of a
structure with the silicon-containing liquid composition as defined
in claim 1.
10. A coating film produced from the silicon-containing liquid
composition as defined in claim 1, said coating film having a
surface resistivity of 7.5.times.10.sup.7 to
1.5.times.10.sup.12.
11. A coating film produced from the silicon-containing liquid
composition as defined in claim 1, said coating film having a water
contact angle of 5.degree. to 35.degree..
12. A silicon-containing liquid composition comprising (A) 100
parts by weight of an organosilicate, calculated as SiO.sub.2, (B)
0.1 to 10 parts by weight of a catalyst, (C) 5,000 to 30,000 parts
by weight of water, and (D) 5,000 to 30,000 parts by weight of a
solvent, and having a hydrolysis percentage of 10,000 to 90,000%, a
weight ratio of the water (C) to the solvent (D) being in the range
of 30:70 to 80:20, said composition being produced by contacting
(A) 100 parts by weight of the organosilicate, calculated as
SiO.sub.2, (B) 0.1 to 10 parts by weight of the catalyst; (C) 500
to 5,000 parts by weight of the water; and (D) 100 to 5,000 parts
by weight of the solvent, with each other; reacting a resultant
mixture until a hydrolysis percentage thereof reaches 1,000 to
90,000%; and diluting a resultant reaction mixture with additional
amounts of the water (C) and the solvent (D) to adjust a final
hydrolysis percentage thereof into 10,000 to 90,000%.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a coating process capable
of preventing a painted or non-painted surface of building
structures, civil engineering structures, industrial equipments,
traffic signs and the like from being contaminated with dirt or
oils, or readily removing contaminants attached thereto by falling
rain or wiping, and a liquid composition suitably used in the
coating process.
[0002] In recent years, great importance is placed on an appearance
of building structures, civil engineering structures, etc., for
maintaining its harmonization with surrounding urban sights. For
this reason, the surface of such structures has been finish-coated
with various low-staining paints in order to enhance an
anti-staining property thereof. As the conventional low-staining
finish-coating methods, there are known those methods in which high
weather-resistant organic paints such as fluororesin-based paints,
acrylic silicone-based paints and urethane-based paints are used to
form a finish coat (top coat).
[0003] Also, recently, such a composition prepared by adding a
small amount of alkylsilicate to these paints has been used to
impart a hydrophilic property to the surface of the resultant
coating film, thereby preventing various contaminants such as dirt
and oils from being attached thereto, and allowing these
contaminants, if attached, to be readily washed off by water drops
of falling rain or the like. On the other hand, inorganic paints
composed mainly of organopolysiloxanes have been positively
developed and recently commercialized because these inorganic
paints are usually excellent in weather resistance, durability,
chemical resistance, heat resistance or the like as compared to the
above organic paints.
[0004] However, in the case where these organic or inorganic paints
are used to form a top coat, there are commonly required
time-consuming additional steps for forming an undercoat and, if
necessary, an intermediate coat between the structure (base
material) and the top coat in order to further enhance the adhesion
therebetween. In particular, the coating film made of the organic
paints tends to be readily contaminated with sand and dust, metal
powder, falling rain (e.g., acidic rain) or exhaust gases when
exposed thereto, resulting in deteriorated appearance of the
structure.
[0005] Also, the paints for top coat which are prepared by adding a
small amount of alkylsilicate to these organic paints, tend to
suffer from various problems such as increase in its viscosity upon
storage, cracks and poor film properties of a coating film produced
therefrom, or the like. Therefore, care must be taken upon handling
and application of these organic paints. On the other hand, many of
the inorganic paints also tend to undergo various problems such as
poor storage stability and cracks of thick coating films similarly
to the above organic paints containing a small amount of
alkylsilicate, and further require an additional heat-curing step.
Therefore, care must also be taken upon handling and application of
these inorganic paints.
[0006] In addition, the above paints are classified into dangerous
substances under the Fire Protection Law because they contain a
large amount of volatile organic solvents. Thus, great care must be
needed for safe handling thereof. A present, it has been strongly
required to solve the above problems concerning safety of paints
and properties of resultant coating films as well as workability
and safety upon coating.
[0007] As a result of the present inventors' earnest studies for
solving the above problems, it has been found that by wiping the
surface of painted or non-painted structures such as building
structures, civil engineering structures, industrial equipments and
traffic signs with a paper, cloth, non-woven fabric, etc., which is
impregnated with a specific silicon-containing liquid composition
mentioned below, or by spray-coating the surface of the painted or
non-painted structures with an aerosol formed of the specific
silicon-containing liquid composition, the obtained coating film
can prevent the surface of the structures from being contaminated,
or can allow contaminants, if attached thereto, to be readily
removed therefrom. The present invention has been attained on the
basis of this finding.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a coating
composition which can be applied directly or through a previous
coating film onto the surface of various structures such as
building structures and civil engineering structures without
formation of any underlying coat, thereby imparting excellent
properties such as anti-staining property and weather resistance
thereto, and a coating process using the coating composition.
[0009] To accomplish the aims, in a first aspect of the present
invention, there is provided a silicon-containing liquid
composition comprising (A) 100 parts by weight of an
organosilicate, calculated as SiO.sub.2, (B) 0.1 to 10 parts by
weight of a catalyst, (C) 100 to 50,000 parts by weight of water,
and (D) 100 to 50,000 parts by weight of a solvent, a weight ratio
of the water (C) to the solvent (D) being in the range of 30:70 to
80:20.
[0010] In a second aspect of the present invention, there is
provided a silicon-containing liquid composition as defined in the
first aspect, having a hydrolysis percentage of 1,000 to
90,000%.
[0011] In a third aspect of the present invention, there is
provided a silicon-containing liquid composition as defined in the
first aspect, further comprising (E) at least one additive selected
from the group consisting of pigments, fillers and paint
additives.
[0012] In a fourth aspect of the present invention, there is
provided a silicon-containing liquid composition as defined in the
first aspect, wherein the organosilicate (A) is represented by the
general formula:
SiO.sub.x(OR).sub.y
[0013] wherein x is a number of 0 to 1.2, and y is a number of 1.4
to 4 with the proviso that (2x+y) is 4; and R is C.sub.1 to C.sub.4
alkyl.
[0014] In a fifth aspect of the present invention, there is
provided a silicon-containing liquid composition as defined in the
first aspect, wherein the organosilicate (A) is methyl
silicate.
[0015] In a sixth aspect of the present invention, there is
provided a coating process comprising:
[0016] coating a surface of a structure with the silicon-containing
liquid composition as defined in the first aspect so as to prevent
the surface of the structure from being contaminated.
[0017] In a seventh aspect of the present invention, there is
provided a coating process comprising:
[0018] coating a surface of an inorganic structure with the
silicon-containing liquid composition as defined in the first
aspect so as to prevent the surface of the inorganic structure from
being contaminated.
[0019] In an eighth aspect of the present invention, there is
provided a coating process comprising:
[0020] forming the silicon-containing liquid composition as defined
in the first aspect into an aerosol; and
[0021] spray-coating the aerosol onto a surface of a structure.
[0022] In a ninth aspect of the present invention, there is
provided a coating process comprising:
[0023] wipe-coating a surface of a structure with the
silicon-containing liquid composition as defined in the first
aspect.
[0024] In a tenth aspect of the present invention, there is
provided a coating film produced from the silicon-containing liquid
composition as defined in the first aspect, said coating film
having a surface resistivity of 7.5.times.10.sup.7 to
1.5.times.10.sup.12.
[0025] In an eleventh aspect of the present invention, there is
provided a coating film produced from the silicon-containing liquid
composition as defined in the first aspect, said coating film
having a water contact angle of 5.degree. to 35.degree..
[0026] In a twelfth aspect of the present invention, there is
provided a silicon-containing liquid composition comprising (A) 100
parts by weight of an organosilicate, calculated as SiO.sub.2, (B)
0.1 to 10 parts by weight of a catalyst, (C) 5,000 to 30,000 parts
by weight of water, and (D) 5,000 to 30,000 parts by weight of a
solvent, and having a hydrolysis percentage of 10,000 to 90,000%, a
weight ratio of the water (C) to the solvent (D) being in the range
of 30:70 to 80:20, said composition being produced by contacting
(A) 100 parts by weight of the organosilicate, calculated as
SiO.sub.2, (B) 0.1 to 10 parts by weight of the catalyst; (C) 500
to 5,000 parts by weight of the water; and (D) 100 to 5,000 parts
by weight of the solvent, with each other; reacting a resultant
mixture until a hydrolysis percentage thereof reaches 1,000 to
90,000%; and diluting a resultant reaction mixture with additional
amounts of the water (C) and the solvent (D) to adjust a final
hydrolysis percentage thereof into 10,000 to 90,000%.
[0027] In accordance with the present invention, it is possible to
enhance properties such as anti-staining property and weather
resistance only by applying the specific silicon-containing liquid
composition directly or through a previous coating film onto the
surface of non-painted or painted structures. In particular, when
painted articles or plastic molded articles placed outside are
coated with the present composition, it becomes possible to prevent
these articles from being contaminated, and further impart a
self-cleaning effect, i.e., an ability of removing contaminants
attached thereto by falling rain, thereby allowing the coated
surface to show an anti-staining property for a long period of
time.
[0028] The properties of the thus-obtained coating film are further
enhanced by incorporating into the composition, various additives
including pigments, fillers and/or paint additives such as anti-sag
agents, leveling agents, anti-cissing agents, adhesion modifiers,
algaecides, bactericides, deodorants and ultraviolet light
absorbers.
DETAILED DESCRIPTION OF THE INVENTION
[0029] In the present invention, there is used a silicon-containing
liquid composition prepared by blending the following components
(A) to (D) and, if required, the component (E) with each other.
[0030] The component (A) is an organosilicate, i.e., a compound
containing organic groups respectively bonded to silicon atom
through oxygen atom. As the organosilicate, there may be
exemplified organoxysilanes containing four organic groups each
bonded to one common silicon atom through oxygen atom, and
organoxysiloxanes having a siloxane main chain ((Si--O).sub.n)
constituted by silicon atoms.
[0031] The organic groups bonded to silicon atom through oxygen
atom are not particularly restricted, and may include, for example,
linear, branched or cyclic alkyl groups. Specific examples of the
organic groups may include methyl, ethyl, n-propyl, i-propyl,
n-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl, neopentyl, hexyl,
octyl or the like. Of these alkyl groups, C.sub.1 to C.sub.4 alkyl
groups are especially preferred. Examples of the other organic
groups may include aryl, xylyl, naphthyl or the like. The
organosilicate may contain two or more different kinds of organic
groups.
[0032] The preferred alkyl groups are those having 1 to 4 carbon
atoms, and may have either a linear or branched structure. Examples
of the preferred alkyl groups may include methyl, ethyl, n-propyl,
i-propyl, n-butyl, i-butyl, sec-butyl or the like. These alkyl
groups may be used in the form of a composite and/or a mixture
thereof. Namely, two or more different kinds of alkyl groups may be
used as the organic groups. Of these alkyl groups, methyl and/or
ethyl are preferred from the standpoints of good solubility of the
organosilicate in the silicon-containing liquid composition as well
as low-staining property of the obtained coating film. Among them,
methyl is most preferred.
[0033] When the alkyl groups having more than four carbon atoms are
used, the obtained silicon-containing liquid composition exhibits a
low solubility, thereby requiring the use of a large amount of
organic solvents. Such a composition have many problems upon
handling since the composition is classified into dangerous
substances under the Fire Protection Law because of the large
content of organic solvents. In addition, the alkyl groups having
more than four carbon atoms shows a poor hydrolyzability, so that
production of SiOH groups in the obtained coating film becomes too
slowly when exposed to outside environments, thereby failing to
exhibit a good anti-staining property.
[0034] Examples of the organoxysilanes may include
tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane,
tetrabutoxysilane, tetraphenoxysilane, dimethoxydiethoxysilane or
the like. Examples of the organoxysiloxanes may include condensates
of the above organoxysilanes. The condensation degree of the
organoxysiloxanes is not particularly restricted, and preferably
lies within the range represented by the following formula:
SiO.sub.x(OR).sub.y
[0035] wherein x is 0.ltoreq.x.ltoreq.1.2, and y is
1.4.ltoreq.y.ltoreq.4 with the proviso that (2x+y) is 4; and R is
an organic group, preferably C.sub.1 to C.sub.4 alkyl.
[0036] The factor or subscript x represents the condensation degree
of the siloxane. When the siloxane shows a molecular weight
distribution, the factor x means an average condensation degree.
Compounds represented by the above formula wherein x=0, are
organoxysilanes as a monomer, and compounds represented by the
above formula wherein 0<x<2, are oligomers corresponding to
condensates obtained by partial hydrolysis condensation. Also,
compounds represented by the above formula wherein x=2, corresponds
to SiO.sub.2 (silica). The condensation degree x of the
organosilicate used in the present invention is preferably in the
range of 0 to 1.2, more preferably 0 to 1.0. The siloxane main
chain may have a linear, branched or cyclic structure or a mixture
thereof.
[0037] The organosilicates having a condensation degree x as high
as more than 1.2 have a high molecular weight and, therefore, a
high viscosity. Such organosilicates tend to be readily gelled upon
storage, resulting in poor storage stability. Thus, it is difficult
to practically use such organosilicates having a condensation
degree x of more than 1.2. In addition, since the organosilicates
exhibit a poor solubility in organic solvents, a large amount of
organic solvents are required to prepare the silicon-containing
liquid composition of the present invention. Therefore, the
obtained silicon-containing liquid composition tends to undergo
various handling problems since the composition containing a large
amount of organic solvents is regarded as dangerous substances
under the Fire Protection Law.
[0038] The above formula: SiO.sub.x(OR).sub.y may be determined by
the following method. The condensation degree x can be readily
obtained by Si-NMR measurement. Specifically, assuming that a
chemical shift value of tetramethylsilane as a standard substance
is 0 ppm, the organosilicate shows 5 groups of peaks Q.sub.0,
Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4 between -75 to 120 ppm as its
chemical shift value. The respective peaks are based on the number
of siloxane bonds constituted by silicon atoms. The peak Q.sub.0
corresponds to a monomer having no siloxane bond; Q.sub.1
corresponds to a compound having one siloxane bond; Q.sub.2
corresponds to a compound having two siloxane bonds; Q.sub.3
corresponds to a compound having three siloxane bonds; and Q.sub.4
corresponds to a compound having four siloxane bonds. After area
ratios of these peaks are determined, the condensation degree x is
calculated from the following formula:
x=A.times.0+B.times.0.5+C.times.1.0+D.times.1.5+E.times.2
[0039] wherein A, B, C, D and E are area ratios of Q.sub.0,
Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4, respectively, with the
proviso that A+B+C+D+E=1. In the case of silica (SiO.sub.2), the
condensation degree is 2. The factor y of the above formula is
determined by the following equation:
2x+y=4.
[0040] Meanwhile, in the case where the organosilicate contains two
or more different kinds of organic groups, the amounts of the
respective organic groups bonded can be readily determined by H-NMR
or .sup.13C-NMR measurement. In this case, the measurement is
carried out by an appropriate method capable of readily identifying
the chemical shift.
[0041] Specific examples of the preferred organosilicates used in
the present invention may include tetramethoxysilane,
tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane,
tetra-n-butoxysilane, tetraisobutoxysilane, tetra-sec-butoxysilane,
tetra-t-butoxysilane and/or partially hydrolyzed condensates
thereof. These organosilicates may be used alone or in combination
of any two or more thereof. Among these organosilicates,
tetramethoxysilane and/or partially hydrolyzed condensates thereof
are preferred for the following reasons. That is, the
tetramethoxysilane and/or partially hydrolyzed condensates thereof
show a high reactivity for hydrolysis and, therefore, can readily
produce silanol groups. As a result, only a small amount of organic
solvent is required to prepare a uniform liquid composition. Thus,
the use of the tetramethoxysilane and/or partially hydrolyzed
condensates thereof is especially preferable for solving the safety
problems since the high anti-staining liquid composition which is
not classified into dangerous substances under the Fire Protection
Law can be readily prepared therefrom.
[0042] The organosilicates contain organic groups respectively
bonded to silicon atom through oxygen atom. Also, the
silicon-containing liquid composition of the present invention may
contain other organosilicon compounds than the organosilicates, for
example, those silicon compounds having organic groups directed
bonded to each other through silicon atom. As the other
organosilicon compounds, there may be exemplified various silane
coupling agents or the like. Specific examples of the other
organosilicon compounds may include trialkoxysilane compounds or
partially hydrolyzed condensates thereof such as methyl
trimethoxysilane, methyl triethoxysilane, methyl tripropoxysilane,
methyl triisopropoxysilane, ethyl trimethoxysilane, ethyl
triethoxysilane, ethyl tripropoxysilane, ethyl triisopropoxysilane,
propyl trimethoxysilane, propyl triethoxysilane, butyl
trimethoxysilane, butyl triethoxysilane, pentyl trimethoxysilane,
pentyl triethoxysilane, hexyl trimethoxysilane, hexyl
triethoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane,
phenyl tripropoxysilane, phenyl triisopropoxysilane, benzyl
trimethoxysilane, benzyl triethoxysilane, 3-glycidoxypropyl
trimethoxysilane, 3-glycidoxypropyl triethoxysilane,
2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane,
2-(3,4-epoxycyclohexyl)eth- yl triethoxysilane,
3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl
triethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane,
3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl
triethoxysilane, 3-aminopropyl triethoxysilane,
N-(2-aminoethyl)-3-aminop- ropyl trimethoxysilane and
3-ureidopropyl triethoxysilane; dialkoxysilane compounds and
partially hydrolyzed condensates thereof such as dimethyl
dimethoxysilane, dimethyl diethoxysilane, diethyl dimethoxysilane,
diethyl diethoxysilane, diphenyl dimethoxysilane, diphenyl
diethoxysilane, 3-glycidoxypropylmethyl dimethoxysilane,
3-methacryloxypropylmethyl dimethoxysilane, 3-mercaptopropylmethyl
dimethoxysilane, 3-aminopropylmethyl dimethoxysilane and
N-(2-aminomethyl)-3-aminopropylmethyl dimethoxysilane; chlorosilane
compounds and partially hydrolyzed condensates thereof such as
methyl trichlorosilane, vinyl trichlorosilane, phenyl
trichlorosilane, methyl dichlorosilane, dimethyl dichlorosilane,
dimethyl chlorosilane, methylvinyl dichlorosilane,
3-chloropropylmethyl dichlorosilane, diphenyl dichlorosilane and
methylphenyl dichlorosilane; 3-mercaptopropyl trimethoxysilane;
3-mercaptopropylmethyl dimethoxysilane; 3-mercaptopropyl
triethoxysilane; 3-mercaptopropylmethyl diethoxysilane;
3-aminopropyl trimethoxysilane; 3-aminopropyl triethoxysilane;
N-3-trimethoxysilylpropyl-m-phenylenediamine;
N,N-bis[3-(methyldimethoxys- ilyl)propyl]ethylenediamine;
N,N-bis[3-(trimethoxysilyl)propyl]ethylenedia- mine;
N-(2-aminoethyl)-3-aminopropylmethyl dimethoxysilane;
N-(2-aminoethyl)-3-aminopropyl trimethoxysilane;
P-[N-(2-aminoethyl) aminomethyl]phenethyl trimethoxysilane; or the
like.
[0043] The silicon-containing liquid composition of the present
invention may contain the above other organosilicon compounds in an
amount of not more than 25 parts by weight, more preferably not
more than 10 parts by weight based on 100 parts by weight of the
organosilicate (A) calculated as SiO.sub.2. The other organosilicon
compounds than the organosilicates contain a less amount of
hydrolyzable functional groups as compared to those of the
organosilicates and, therefore, are remarkably deteriorated in
contribution to anti-staining property. As a matter of course, the
composition of the present invention may not contain the other
organosilicon compounds. Also, the silicon-containing liquid
composition of the present invention may contain such a silicon
compound containing hydrolyzable functional groups other than the
organoxy groups such as various halogen elements. However, such a
halogen-containing silicon compound tends to generate cumbersome
substances such as hydrochloric acid, resulting in environmental
problems. For this reason, the silicon compound may be contained in
the composition in an amount of not more than 20 parts by weight,
more preferably not more than 10 parts by weight, at most, based on
100 parts by weight of the organosilicate calculated as SiO.sub.2.
As a matter of course, the composition of the present invention may
not contain such a silicon compound.
[0044] As the component (B), there may be use those catalysts
capable of hydrolyzing the organosilicate. Specific examples of the
catalyst (B) may include inorganic acids such as hydrochloric acid,
sulfuric acid, nitric acid and phosphoric acid; organic acids such
as acetic acid, benzenesulfonic acid, toluenesulfonic acid,
xylenesulfonic acid, ethylbenzenesulfonic acid, benzoic acid,
phthalic acid, maleic acid, formic acid and oxalic acid; alkali
catalysts such as sodium hydroxide, potassium hydroxide, calcium
hydroxide, ammonia and organic amine compounds; organometallic
compounds or metal alkoxide compounds other than the
organosilicates, e.g., organotin compounds such as dibutyl tin
dilaurate, dibutyl tin dioctoate and dibutyl tin diacetate,
organoaluminum compounds such as aluminum tris(acetylacetonate),
aluminum monoacetylacetonate bis(ethylacetoacetate), aluminum
tris(ethylacetoacetate) and ethylacetoacetate aluminum
diisopropionate, organotitanium compounds such as titanium
tetrakis(acetylacetonate), titanium
bis(butoxy)-bis(acetylacetonate) and titanium tetra-n-butoxide, and
organozirconium compounds such as zirconium
tetrakis(acetylacetonate)- , zirconium
bis(butoxy)-bis(acetylacetonate), zirconium
(isopropoxy)-bis(acetylacetonate) and zirconium tetra-n-butoxide;
boron compounds such as boron tri-n-butoxide and boric acid; or the
like.
[0045] These catalysts may be used alone or in combination of any
two or more thereof. In the case where the silicon-containing
liquid composition of the present invention is applied onto the
surface of painted or non-painted structures such as building
structures, civil engineering structures, industrial equipments,
transportation equipments and traffic signs, organometallic chelate
compounds or metal alkoxide compounds are preferably used for
preventing the base material thereof from being corroded by the
catalyst.
[0046] The amount of the catalyst (B) added is preferably 0.1 to 10
parts by weight, more preferably 0.5 to 5 parts by weight based on
100 parts by weight of the organosilicate calculated as SiO.sub.2.
When the amount of the catalyst added is less than 0.1 part by
weight, the obtained silicon-containing liquid composition is
deteriorated in storage stability, and the coating film produced
from the composition fails to exhibit a sufficient anti-staining
property. When the catalyst is used in the above-specified range of
0.1 to 10 parts by weight, it is possible to impart a sufficient
storage stability and film properties to the silicon-containing
composition and the coating film produced therefrom, respectively.
Therefore, it is not necessary to use the catalyst in an amount of
more than 10 parts by weight. The catalyst (B) may be added by any
suitable method, e.g., may be added in the form of a solution
prepared by dissolving the catalyst in the organosilicate, or a
solution prepared by dissolving the catalyst in water or the
solvent. The catalyst may be mixed and dissolved in the
organosilicate and/or water or the solvent at room temperature. If
it is difficult to dissolve the catalyst at room temperature, the
mixture may be heated.
[0047] The amount of water as the component (C) blended is 100 to
50,000 parts by weight, preferably 500 to 10,000 parts by weight
based on 100 parts by weight of the organosilicate calculated as
SiO.sub.2. This means that the water is added in a considerably
excessive amount as compared to its stoichiometric amount capable
of hydrolyzing organoxy groups of the organosilicate. It is
considered that the addition of such an excessive amount of water
allows silanol groups produced by hydrolysis of the organosilicate
to coexist with a large amount of water, thereby preventing the
condensation reaction of the silanol groups and, therefore,
enhancing the storage stability of the obtained hydrolyzed liquid
composition. In addition, since the amount of organic solvents
added such as alcohols may be reduced, the obtained composition can
exhibit a low flash point or burning point, thereby considerably
improving the safety upon handling the composition.
[0048] When the amount of water (C) added is less than 100 parts by
weight based on 100 parts by weight of the organosilicate
calculated as SiO.sub.2, the Si content in the obtained
silicon-containing liquid composition becomes too large, so that
the composition tends to be readily gelled, resulting in poor
storage stability and low anti-staining property thereof upon
practical use. When the amount of water (C) added is more than
50,000 parts by weight, the Si content in the obtained
silicon-containing liquid composition is too small, so that the
coating film produced therefrom fails to show a sufficient
anti-staining property.
[0049] The silicon-containing liquid composition of the present
invention preferably has a hydrolysis percentage of 1,000 to
90,000%. The water as the component (C) may be added at one time or
stepwise. In the case where the water is added stepwise for
diluting the composition, it is preferred that 500 to 5,000 parts
by weight of water is first added in order to conduct a first stage
of the hydrolysis reaction where the hydrolysis percentage of the
composition is adjusted to 1,000 to 90,000%, and then 500 to 30,000
parts by weight of water is added to conduct a subsequent second
stage of the hydrolysis reaction where the hydrolysis percentage of
the composition is adjusted to 10,000 to 90,000%. Upon such a
stepwise addition of water, the amount of the below-mentioned
solvent added is preferably controlled in a stepwise manner.
[0050] The water (C) used in the present invention is not
particularly restricted. For example, a tap water as well as a
deionized water or a ultrapure water may be selectively used
according to objects and requirements. For example, in the case
where the composition of the present invention is applied to base
materials readily corroded by acids such as soft steel, copper and
aluminum, heat-resistant coats, moisture-proof coats,
chemical-resistant coats, barrier coats, electric or electronic
materials such as insulating coats, a desalted water may be
suitably used. Also, in the case where the composition is applied
to semiconductors or the like which should be free from inclusion
of impurities, a ultrapure water may be suitably used.
[0051] The solvent as the component (D) is not particularly
restricted. As the solvent, there may be usually used various
organic solvents such as alcohols, glycol derivatives,
hydrocarbons, esters, ketones, ethers or the like. These solvents
may be used alone or in the form of a mixture of any two or more
thereof. Specific examples of the alcohols may include methanol,
ethanol, n-propanol, isopropanol, n-butanol, isobutanol,
acetylacetone alcohol or the like.
[0052] Specific examples of the glycol derivatives may include
ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol
monoethyl ether, propylene glycol, propylene glycol monomethyl
ether, propylene glycol monoethyl ether, diethylene glycol
monomethyl ether, diethylene glycol monoethyl ether, ethylene
glycol monomethyl ether acetate, ethylene glycol monoethyl ether
acetate, propylene glycol monomethyl ether acetate, propylene
glycol monoethyl ether acetate or the like.
[0053] Specific examples of the hydrocarbons may include benzene,
toluene, xylene, kerosene, n-hexane or the like. Specific examples
of the esters may include methyl acetate, ethyl acetate, propyl
acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate,
butyl acetoacetate or the like. Specific examples of the ketones
may include acetone, methyl ethyl ketone, methyl isobutyl ketone,
acetyl acetone or the like. Specific examples of the ethers may
include ethyl ether, butyl ether, methoxy ethanol, ethoxy ethanol,
dioxane, furan, tetrahydrofuran or the like. Of these solvents,
alcohols, especially C.sub.1 to C.sub.3 alcohols such as methanol,
ethanol and isopropanol, or glycol derivatives such as propylene
glycol monomethyl ether and diethylene glycol monoethyl ether, are
preferred because these solvents can exhibit a good handling
property, and can impart a good storage stability to the obtained
silicon-containing liquid composition, and a good anti-staining
property to the coating film produced from the composition.
[0054] The amount of the solvent (D) added is preferably 100 to
50,000 parts by weight, more preferably 500 to 10,000 parts by
weight based on 100 parts by weight of the organosilicate
calculated as SiO.sub.2. When the amount of the solvent added is
less than 100 parts by weight based on 100 parts by weight of the
organosilicate calculated as SiO.sub.2, it may be difficult to
uniformly dissolve the organosilicate, the catalyst and water
together. When the amount of the solvent added is more than 50,000
parts by weight, the Si content in the obtained silicon-containing
liquid composition is too small, so that the coating film produced
from the composition may not exhibit a sufficient anti-staining
property. In addition, the composition containing such a large
amount of the solvent is regarded as dangerous substances under the
Fire Protection Law, resulting in poor handling property thereof.
Meanwhile, the above-described amount of the solvent added includes
an amount of alcohol produced by hydrolysis of the organosilicate
in addition to amount of the solvent initially added.
[0055] The solvent (D) may be added at one time or stepwise. When
the solvent is added stepwise for diluting the composition, it is
preferred that 100 to 5,000 parts by weight of the solvent is first
added together with water added at the first stage in order to
conduct the first hydrolysis reaction, and then 5,000 to 30,000
parts by weight of the solvent is added together with water added
for the second stage of the hydrolysis reaction.
[0056] Mixing of Respective Components for Preparation of
Silicon-Containing Liquid Composition:
[0057] Upon the preparation of the silicon-containing liquid
composition of the present invention, the respective components
(A), (B), (C) and (D) are uniformly mixed with each other at the
above-specified mixing ratios, preferably until a transparent
solution is obtained. The mixing temperature and mixing method are
not particularly restricted. The mixing can be sufficiently
conducted at about room temperature without heating. For example,
the respective components (A) to (D) may be sequentially charged at
room temperature into a mixing vessel, a mixing kiln, or a mixing
container such as a mixer, a drum can and a kerosene can, and then
mixed together by stirring, rotation, reverse rotation, vibration
or the like, thereby preparing a uniform and transparent one-part
type silicon-containing liquid composition. Alternatively, the
silicon-containing liquid composition may be of a two-part type
which comprises a main agent and a curing agent which are mixed
together upon use. In the two-part type liquid composition, the
main agent may be composed of alkylsilicate, and the curing agent
may be in the form of a mixture of the catalyst, water and the
organic solvent, or the main agent may be in the form of a mixture
of the alkylsilicate and the catalyst, and the curing agent may be
in the form of a mixture of water and the organic solvent, though
not limited thereto.
[0058] In the present invention, the silicon-containing liquid
composition may further contain as the component (E), an additive
usable in ordinary paints such as pigments, e.g., colorants and
extender pigments, fillers or the like. The amount of the component
(E) added is not particularly restricted, and may be appropriately
selected from such a range as not to adversely affect the effect of
the present invention. Specific examples of the colorants as the
additive (E) may include inorganic pigments such as titanium oxide,
zinc oxide, carbon black, ferric oxide (iron oxide red), lead
chromate, chrome yellow, yellow iron oxide, ochre, ultramarine blue
and cobalt green; organic pigments such as azo-based,
naphthol-based, pyrazolone-based, anthraquinone-based,
perylene-based, quinacridone-based, bisazo-based,
isoindolinone-based, benzoimidazole-based, phthalocyanine-based and
quinaphthalone-based pigments; or the like. Specific examples of
the extender pigments may include heavy calcium carbonate, clay,
kaolin, talc, precipitated barium sulfate, barium carbonate, white
carbon, diatomaceous earth or the like.
[0059] As the other additives usable as the component (E), there
may be exemplified dispersing agents, anti-settling agents,
anti-sag agents, delustering agents, plasticizers, defoamers,
leveling agents, anti-cissing agents, adhesion modifiers,
antiseptic agents, algaecides, bactericides, deodorants,
ultraviolet light absorbers or the like. The additive may be added
in a small amount as long as the aimed effect can be obtained by
the addition of the additives. The amount of the additive added is
not particularly restricted, and a sufficient effect can be
obtained by adding the additive in an amount of usually 0.01 to
10.0 parts by weight, preferably 0.01 to 1.0 part by weight based
on 100 parts by weight of the silicon-containing liquid composition
of the present invention.
[0060] The method of adding the additive as the component (E) is
not particularly restricted. For example, after all of the
components (A) to (D) are blended together to prepare a one-part
type silicon-containing liquid composition, the additive (E) may be
added to the obtained composition. Alternatively, the additive (E)
may be added to any of the alkylsilicate, water, the organic
solvent and the like in which the additive can be readily dissolved
or dispersed, followed by mixing the respective components
together. Also, in the case of the two-part type silicon-containing
liquid composition composed of the main agent and the curing agent
which are mixed together upon use, the additive (E) may be added to
either the main agent or the curing agent.
[0061] Thus, the silicon-containing liquid composition of the
present invention can be produced by blending the above-described
components together. The organosilicate content in the
silicon-containing liquid composition is usually 0.05 to 15% by
weight, preferably 0.1 to 10% by weight, calculated as SiO.sub.2 in
the organosilicate. When the organosilicate content is less than
0.05% by weight calculated as SiO.sub.2 in the organosilicate, the
coating film formed on the surface of painted or non-painted
structures such as building structures, civil engineering
structures, industrial equipments, transportation equipments and
traffic signs, fails to exhibit a sufficient anti-staining
property. When the organosilicate content is more than 15% by
weight calculated as SiO.sub.2 in the organosilicate, such a
composition having a too high organosilicate content tends to be
gelled when stored, thereby causing problems such as poor storage
stability upon practical use.
[0062] The thus obtained silicon-containing liquid composition of
the present invention is capable of forming a colorless transparent
coating film at ordinary temperature. The obtained coating film is
an ultrathin film and, therefore, does not damage a touch of an
underlying base material. Further, since the coating film exhibits
an extremely low surface resistivity ranging from
7.5.times.10.sup.7 to 1.5.times.10.sup.12 .OMEGA..multidot.cm, the
chargeable voltage thereof is limited to not more than 10 mV,
resulting in good anti-static property. In this case, as to
friction coefficients of the coating film, the static friction
coefficient thereof is 0.5 to 1.2, and the kinetic friction
coefficient thereof is 0.3 to 1.2. Further, the coating film
produced from the silicon-containing liquid composition of the
present invention exhibits an excellent hydrophilic property, and
has a water contact angle as low as 5.degree. to 35.degree.. For
this reason, the coating film is free from attachment of fur and
fallstreifen. In addition, the coating film produced from the
silicon-containing liquid composition of the present invention
exhibits an excellent durability, especially a high resistance to
acidic rain. Therefore, even when exposed to outside environments
for a long period of time, the coating film can continuously
maintain the above properties and can prevent the underlying
material from being adversely affected. Also, the coating film
exhibits an excellent chemical resistance. Therefore, even when the
coating film is exposed to outside environments in snow country,
snow-melting agents attached thereto such as calcium chloride can
be removed only by water-washing, thereby inhibiting salt damage
thereto.
[0063] Coating Method
[0064] The silicon-containing liquid composition of-the present
invention can be applied onto the surface of painted or non-painted
structures such as building structures, civil engineering
structures, industrial equipments, transportation equipments and
traffic signs by simplified methods, e.g., by wipe-coating the
surface of these structures with a paper, cloth or non-woven fabric
impregnated therewith, or by spray-coating an aerosol thereof onto
the surface of these structures. Also, the silicon-containing
liquid composition of the present invention may be coated by
various ordinary methods such as brush-coating, roller-coating and
spray-coating, using a roll coater, a flow coater or the like.
[0065] As the structures to be coated with the silicon-containing
liquid composition of the present invention, there may be
exemplified civil engineering structures such as tunnels, dams,
bridges, tanks and flues; building structures such as houses and
buildings; cultural assets such as temples, shrines, stone statues
and ruins; transportation equipments such as automobiles, air
planes, railway rolling stocks and ships; industrial equipments;
traffic signs; outdoor structures such as guard rails; or the like.
These structures may be previously painted or non-painted. Specific
examples of the surface to be coated with the composition of the
present invention may include exterior and interior surfaces
(inside and outside wall surfaces) of these structures, wall
surfaces of bath room and kitchen in the building structures, outer
surfaces of housings of furnitures, refrigerators, televisions or
air conditioners, stainable locations such as window glass, or the
like. Meanwhile, although various structures are exemplified above,
the present invention is not limited thereto, and the
silicon-containing liquid composition of the present invention can
also be applied onto various objects or locations in order to
impart a good anti-staining property thereto.
[0066] The first coating method of the present invention is such a
simple method of impregnating a suitable medium such as paper,
cloth and non-woven fabric with the silicon-containing liquid
composition of the present invention, wringing the medium
appropriately, if required, and then wiping the surface to be
coated, with the medium. The second coating method of the present
invention is such a method of forming the silicon-containing liquid
composition of the present invention into an aerosol, and then
spray-coating the aerosol onto the surface of structures.
[0067] In the first coating method, a paper, cloth or non-woven
fabric may be preliminarily impregnated with the silicon-containing
liquid composition of the present invention, stored in a sealed
container, and taken out from the container when needed in order to
wipe-coat the surface of structures therewith. Alternatively, upon
use, a paper, cloth or non-woven fabric is impregnated with the
silicon-containing liquid composition and squeezed appropriately,
and then the surface of structures may be wipe-coated therewith.
Using the first coating method, it becomes possible to simply apply
the composition of the present invention onto either a freshly
coated, already coated or non-painted surface of the structures.
Since the first coating method is performed by wipe-coating, the
composition applied is free from problems such as sag. In addition,
the first coating method can be performed without preliminarily
cleaning the surface to be treated, since contaminants previously
attached can be wiped off simultaneously with the wipe-coating. The
drying time after the wipe-coating is not less than 30 minutes,
preferably not less than 2 hours at ordinary temperature.
[0068] In the second coating method, the silicon-containing liquid
composition of the present invention is filled together with a
propellant into a container to prepare an aerosol. As the
propellant, there may be used known propellants such as dimethyl
ether and LP gases. These propellants may be used alone or in the
form of a mixture of any two or more thereof. The thus obtained
aerosol may be applied onto the surface of the same structures as
described in the above first coating method. The second coating
method can be readily performed by directly spraying the aerosol
onto the surface of structures. Meanwhile, if any contaminants are
already attached onto the painted or non-painted surface of
existing structures and the aerosol is spray-coated on such a
surface, it is preferred that the surface is pre-treated in order
to clean off the contaminants therefrom before spray-coating. On
the contrary, in the case of structures having a freshly painted or
repair-painted surface, or freshly prepared structures having a
non-painted surface, it is possible to directly spray the aerosol
onto the surface since no contaminants are present thereon. In this
case, the aerosol can be spray-coated onto the freshly painted or
repair-painted surface of structures or the non-painted surface of
freshly prepared structures notwithstanding these surfaces are
either dried or non-dried. The coating amount of the aerosol is in
the range of 20 to 50 g/m.sup.2.
[0069] Thus, in the above simple coating methods using the
silicon-containing liquid composition of the present invention, it
is possible to form on the surface of various structures, a thin
coating film providing a good finished surface which is free from
defects such as unevenness, sag and cracks, and is improved in film
properties such as anti-staining property and weather resistance.
As described above, the silicon-containing liquid composition of
the present invention not only is stably stored in a liquid state,
but also is not classified into dangerous substances under the Fire
Protection Law because of a less content of organic solvents.
Therefore, the composition of the present invention is preferred
from the viewpoint of safety upon use. It is considered that the
above advantages of the present invention can be achieved by
blending the respective components at the well-balanced mixing
ratio.
[0070] Thus, the silicon-containing liquid composition of the
present invention can be maintained in a stable liquid state
despite a less solvent content thereof and, therefore, is inhibited
from being classified into dangerous substances under the Fire
Protection Law. As a result, the composition can be improved in
handling property and safety upon coating. In addition, the coating
method using the above silicon-containing liquid composition can
provide a simplified method capable of forming a uniform thin
coating film on the surface of various structures. Further, the
thus obtained coating film can exhibit excellent properties such as
anti-staining property, weather resistance and contaminant-removing
property.
EXAMPLES
[0071] The present invention will be described in more detail below
by reference to examples, but these examples are not intended to
limit the scope of the present invention thereto. Meanwhile, "%"
used herein represents "% by weight" unless otherwise
specified.
Preparation Example 1
[0072] The following components wherein "MS51" represents a
partially hydrolyzed condensate of methyl silicate (tradename: "MKC
Silicate MS51" produced by Mitsubishi Chemical Corporation;
formula: SiO.sub.0.8(OCH.sub.3).sub.2.4), were mixed together at
the below-mentioned mixing ratio at room temperature for 20
minutes, thereby preparing a silicon-containing composition (1) in
the form of a colorless transparent liquid.
[0073] Composition:
1 MS51 100 parts by weight* (calculated as SiO.sub.2) 8% solution
of aluminum-based catalyst 1.8 parts by weight Industrial ethanol
5,385 parts by weight Ion-exchanged water 7,500 parts by weight
*The content of MS51 calculated as SiO.sub.2 was 0.8% by
weight.
[0074] The thus obtained silicon-containing composition (1) was
evaluated according to the testing method for dangerous substances
prescribed under the Fire Protection Law (Government Ordinance for
"Regulation of Dangerous Objects" Article 1, .sctn.3 through
Article 1, .sctn.8; Ministerial Ordinance for "Tests and Properties
of Dangerous Objects"). It was confirmed that the alcohol content
of the silicon-containing composition (1) was less than 60% by
weight, and the water content thereof was about 57% by weight. In
addition, as a result of the measurements conducted in
Kita-Kyushu-City Fire Defense Science Research Institute, it was
confirmed that the flash point (tag-closed type) of the
silicon-containing composition (1) was 25.3.degree. C., and the
burning point (tag-open type) thereof was 31.5.degree. C.
Meanwhile, the flash point and burning point of 60-wt. % ethanol
aqueous solution were 22.6.degree. C. and 24.7.degree. C.,
respectively. As a result, it was recognized that the
silicon-containing composition (1) did not classified into the
dangerous substances prescribed under the Fire Protection Law.
Meanwhile, under the Fire Protection Law, substances having an
alcohol content of less than 60% by weight and flash and burning
points higher than those of the 60-wt. % ethanol aqueous solution
can be excluded from the dangerous substances prescribed
thereunder.
Preparation Example 2
[0075] 0.5 part by weight of an anti-cissing agent (tradename:
"BYK-301" produced by BYK Chemie Co., Ltd.) was further added to
the 1,000 parts by weight of the silicon-containing composition (1)
prepared in Preparation Example 1. The resultant mixture was mixed
at room temperature for 20 minutes, thereby preparing a
silicon-containing composition (2).
Preparation Example 3
[0076] The same procedure as defined in Preparation Example 1 was
conducted except that a partially hydrolyzed condensate of ethyl
silicate (tradename "ES40" produced by Hulse Japan Co., Ltd.) was
used instead of "MKC Silicate MS51" and the amount of the
industrial ethanol was controlled such that the content of "ES40"
(calculated as SiO.sub.2) in the liquid was 0.8% by weight.
Although the raw mixture having the same composition as that used
in Preparation Example 1 was mixed at room temperature for 20
minutes, the "ES40" remained not dissolved, and the obtained liquid
became whitely turbid. For this reason, the amounts of the
industrial ethanol and the ion-exchanged water were increased up to
minimum amounts capable of completely dissolving the "ES40" and
obtaining a uniform colorless transparent solution. The raw mixture
thus controlled was mixed at room temperature for 20 minutes,
thereby preparing a silicon-containing composition (3). It was
confirmed that the silicate content in the composition was 0.8% by
weight, calculated as SiO.sub.2. The composition of the raw mixture
used above is shown below.
[0077] Composition:
2 ES40 100 parts by weight (calculated as SiO.sub.2) 8% solution of
aluminum-based catalyst 1.8 parts by weight Industrial ethanol
8,531 parts by weight Ion-exchanged water 4,296 parts by weight
[0078] The thus obtained silicon-containing composition (3)
contained the industrial ethanol in an amount of about 65% by
weight, i.e., had an alcohol content of not less than 60% and,
therefore, was regarded as the dangerous substances prescribed
under the Fire Protection Law. Thus, when ethyl silicate was used,
a large amount of alcohol was to be added in order to obtain a
uniform liquid composition, resulting in production of the
dangerous substances under the Fire Protection Law. Therefore, it
was confirmed that the use of methyl silicate was preferred from
the viewpoint of safety.
[0079] Preparation Example 4
[0080] The following components were mixed together and reacted at
40.degree. C. for 2 hours, thereby preparing a silicon-containing
composition (8) in the form of a colorless transparent liquid.
[0081] Composition:
3 MS-51 100 parts by weight (calculated as SiO.sub.2) 8% solution
of aluminum-based catalyst 1.8 parts by weight Industrial ethanol
3,000 parts by weight Ion-exchanged water 2,000 parts by weight
Preparation Example 5
[0082] The following components were mixed together and reacted at
50.degree. C. for 1 hour.
[0083] Composition:
4 MS-51 100 parts by weight (calculated as SiO.sub.2) 8% solution
of aluminum-based catalyst 1.8 parts by weight Industrial ethanol
1,500 parts by weight Ion-exchanged water 1,500 parts by weight
[0084] The obtained silicon-containing composition was further
diluted at room temperature to adjust the following final mixing
ratio, thereby preparing a silicon-containing composition (9) in
the form of a colorless transparent liquid.
[0085] Composition:
5 MS-51 100 parts by weight (calculated as SiO.sub.2) 8% solution
of aluminum-based catalyst 1.8 parts by weight Industrial ethanol
5,000 parts by weight Ion-exchanged water 5,000 parts by weight
Preparation Example 6
[0086] The following components were mixed together and reacted at
60.degree. C. for 2 hours, thereby preparing a silicon-containing
composition (10) in the form of a colorless transparent liquid.
[0087] Composition:
6 MS-51 100 parts by weight (calculated as SiO.sub.2) 8% solution
of aluminum-based catalyst 1.8 parts by weight Industrial ethanol
1,250 parts by weight Ion-exchanged water 250 parts by weight
Preparation Example 7
[0088] The following components were mixed together and reacted at
room temperature for 1 hours, thereby preparing a
silicon-containing composition (11) in the form of a colorless
transparent liquid.
[0089] Composition:
7 MS-51 100 parts by weight (calculated as SiO.sub.2) 8% solution
of aluminum-based catalyst 1.8 parts by weight Industrial ethanol
2,500 parts by weight Ion-exchanged water 675 parts by weight
Example 1
[0090] A duster was immersed in the silicon-containing composition
(3), and lightly wrung by hand. Then, an exterior painted surface
of an automobile was wiped with the impregnated duster. The amount
of the diluted liquid composition applied was 16 g/m.sup.2.
Example 2
[0091] A paper towel was impregnated with the silicon-containing
composition, and stored in a sealed container. After one month, the
impregnated paper towel was taken out from the container. The
stained surface of a heavy oil tank having a top coat made of a
fluororesin-based resin paint (tradename: "PF-250B" produced by
Dainippon Shikizai Kougyo Co., Ltd.) was washed with water and then
dried in air. The thus cleaned surface of the heavy oil tank was
wiped with the impregnated paper towel in order to form a coating
film of the silicon-containing composition thereon. It was
confirmed that the amount of the silicon-containing composition (2)
applied was about 50 g/m.sup.2.
Example 3
[0092] The silicon-containing composition (2) prepared in
Preparation Example 2 and LPG as a propellant were charged at a
volume ratio of 100:200 into an aerosol container, thereby
preparing an aerosol composition. The thus obtained aerosol
composition was spray-coated onto the surface of the same heavy oil
tank as used in Example 2. It was confirmed that the amount of the
aerosol applied was 35 g/m.sup.2.
Comparative Example 1
[0093] The same procedure as defined in Example 1 was conducted
except that a part of the surface of the automobile remained
uncoated with the diluted solution of the silicon-containing
composition (2).
Comparative Example 2
[0094] The same procedure as defined in Example 2 was conducted
except that a part of the surface of the heavy oil tank remained
uncoated with the silicon-containing composition (2).
[0095] The coated surfaces obtained in Examples 1 to 3 and
Comparative Examples 1 and 2 were exposed to outside environments
for half a year (test period: from June to December of 1998;
location: Sanwa-machi, Sarushima-gun, Ibaragi-ken). After the
exposure to outside environments, the coated surfaces were visually
observed to determine the degree of contamination thereof. The
results are shown in Table 1 below.
[0096] Table 1: Observation Results of Contamination After
Half-Year Exposure to Outside Environments
8 Initial Examples and contamination Degree of contamination
Comparative on surface of after half year Examples coating film
Dirt Fallstreifen Example 1 None Small None Example 2 None Small
None Example 3 None Small None Comparative None Large Some Example
1 Comparative None Large Much Example 2
[0097] In the column "degree of contamination" of Table 1, "Small"
means that a small amount of dirt attached onto the coating was
visually observed; "Large" means that a large amount of dirt
attached was visually observed; and "None" in the sub-column
"Fallstreifen" means that no fall streaks were visually
observed.
Comparative Example 3
[0098] The same procedure as defined in Preparation Example 2 was
conducted except that the amount of the industrial ethanol blended
was changed to 80 parts by weight, thereby preparing a
silicon-containing composition (4). The thus obtained composition
was a turbid liquid, and failed to form a uniform solution.
Comparative Example 4
[0099] The same procedure as defined in Preparation Example 2 was
conducted except that the amount of the industrial ethanol blended
was changed to 60,000 parts by weight, thereby preparing a
silicon-containing composition (5). The thus obtained composition
was coated on the surface of the objective, and exposed to outside
environments in the same manner as in Example 1. As to the degree
of contamination of the coating after half-year exposure, the
attachment of dirt was evaluated as "Large", and the fallstreifen
was evaluated as "Much".
Comparative Example 5
[0100] The same procedure as defined in Preparation Example 2 was
conducted except that the amount of water blended was changed to 70
parts by weight, thereby preparing a silicon-containing composition
(6). The thus obtained composition was coated on the surface of the
objective, and exposed to outside environments in the same manner
as in Example 1. As to the degree of contamination of the coating
after half-year exposure, the attachment of dirt was evaluated as
"Large", and the fallstreifen was evaluated as "Much".
Comparative Example 6
[0101] The same procedure as defined in Preparation Example 2 was
conducted except that the amount of water blended was changed to
60,000 parts by weight, thereby preparing a silicon-containing
composition (7). The thus obtained composition was coated on the
surface of the objective, and exposed to outside environments in
the same manner as in Example 1. As to the degree of contamination
of the coating after half-year exposure, the attachment of dirt was
evaluated as "Large", and the fallstreifen was evaluated as
"Much".
Example 4
[0102] A glass plate was wiped with the silicon-containing
composition (2) prepared in Preparation Example 2.
Example 5
[0103] A glass plate was wiped with the silicon-containing
composition (8) prepared in Preparation Example 4.
Example 6
[0104] A glass plate was wiped with the silicon-containing
composition (9) prepared in Preparation Example 2.
Comparative Example 7
[0105] A glass plate was wiped with the silicon-containing
composition (5) used in Comparative Example 4.
Comparative Example 8
[0106] A glass plate was wiped with the silicon-containing
composition (6) used in Comparative Example 6.
Comparative Example 9
[0107] A glass plate was wiped with the silicon-containing
composition (10) prepared in Preparation Example 6.
Comparative Example 10
[0108] A glass plate was wiped with the silicon-containing
composition (11) prepared in Preparation Example 7.
[0109] The water contact angles and surface resistivities of the
coated surfaces of the glass plates prepared in Examples 4-6 and
Comparative Examples 7-10 were measured under 50% RH at 23.degree.
C. by a CA-A Type manufactured by Kyowa Kaimen Kagaku Co., Ltd.
(water contact angle) and by TR8411 Type manufactured by Advantest
Co., Ltd. (surface resistivity), respectively. The results are
shown in Table 2.
9 TABLE 2 Example 6 At reaction Final Comparative Comparative
Comparative Comparative Example 4 Example 5 stage product Example 7
Example 8 Example 9 Example 10 Water/Ethanol 58/42 40/60 50/50
50/50 11/89 92/8 17/83 21/89 ratio Hydrolysis 20800 5540 4150 13800
20800 166000 692 1870 percentage (%) Water contact 20 18 -- 15 62
54 50 47 angle Surface 2.1 .times. 10.sup.8 1.5 .times. 10.sup.8 --
8.0 .times. 10.sup.7 1.1 .times. 10.sup.14 6.5 .times. 10.sup.13
4.2 .times. 10.sup.13 2.5 .times. 10.sup.13 resistivity
(.OMEGA.)
* * * * *