JP3442160B2 - Method of forming SiO2 ceramic coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention_TwoSeries ceramic coating
The present invention relates to a method for forming a film. [0002] 2. Description of the Related Art To obtain high heat, wear and corrosion resistance.
Organic paints are not enough,
Is used. Conventionally, a method for forming a ceramic coating has been
In general, PVD (sputtering method, etc.), CVD, sol
Gel method, polytitanocarbosilane paint, poly (dis
L) Silazane-based paints and the like are known. But
All of the above methods have problems. Sand
In the PVD and CVD methods, equipment and manufacturing costs are expensive.
is there. In sol-gel method, required firing temperature is 500 ℃ or more
And a thick film cannot be obtained. Polytitanocarbo
Table for low temperature firing (400 ° C or lower) for silane-based paints
Surface strength is insufficient. Poly (disil) silazane-based polymerization
Those using a body have difficulty in construction and cause cracks
You. Applicants have proposed a low cost, good ceramic.
Polysilazane, polymetallosila
It discloses a method using Zan, and the firing temperature is 200 to
Although the temperature is relatively low at 500 ° C, low-temperature firing requires film quality.
Not so good. The present applicant has further filed Japanese Patent Application No. 5-31818.
No. 8, a coating containing polysilazane
After heat treatment, expose to a steam atmosphere or
Low temperature forming method of ceramic coating immersed in distilled water
Disclosed. According to this method, a relatively low temperature of 150 ° C. or less
A dense ceramic coating can be easily obtained at a high temperature. But
However, this method requires heat treatment at relatively low temperatures.
Required and for treatment with steam or catalyst-containing solutions
It takes a relatively long time. [0006] SUMMARY OF THE INVENTION Therefore, the present invention
It solves the problems in the prior art as described above,
Dense ceramic with excellent wear and corrosion resistance and no cracks
Forming a film at a lower temperature and shorter time than before
The aim is to provide a method. [0007] SUMMARY OF THE INVENTION These and other aspects of the present invention
The other purpose is (1) Si—H bond and / or N
Forming a polysilazane film having an —H bond,
Contact a mixed solution containing alkoxysilane and water.
Characterized by the following:_TwoMethod of forming ceramic ceramic coating
Achieved by [0008] In the following, the embodiments of the present invention will be divided into columns.
Raise it. (2) The polysilazane has a general formula (I): [0009] Embedded image (In the above formula, R¹, R^TwoAnd R^ThreeIs German
First, a hydrogen atom, an alkyl group, an alkenyl group,
Alkyl, aryl, or other than these groups to silicon
Groups in which the directly linked group is carbon, alkylsilyl groups,
Represents an amino group or an alkoxy group, provided that R¹, R^Two
And R^ThreeAt least one is a hydrogen atom)
Number average molecular weight of 100 to 5 having a skeleton consisting of
Ten thousand polysilazanes or denature these polysilazanes
The method according to (1), which is characterized in that: (3) The alkoxysilane is Si (O
R)_Four[Wherein, R is each independently an alkyl group,
Nil group, cycloalkyl group, aryl group, alkylamido
Represents an alkyl group or an alkylsilyl group).
The method according to (1) or (2), which is characterized in that: (4) The alkoxysilane is represented by R '_nS
i (OR)_4-n[Wherein, R is each independently an alkyl
Group, alkenyl group, cycloalkyl group, aryl group,
Represents a alkylamino group or an alkylsilyl group;
Is each independently a vinyl group, an epoxy group,
Represents an amino group, a methacryl group or a mercapto group,
And n is an integer of 1 to 2].
The method according to (1) or (2). (5) The alkoxysilane is represented by R '
_n(RO)_3-nSi-R "-Si (OR)_3-mR '
_mWherein R is independently an alkyl group, an alkenyl
Group, cycloalkyl group, aryl group, alkylamino group
Or an alkylsilyl group, and R ′ is each independently
In addition to the above R, vinyl group, epoxy group, amino group,
And R "represents a divalent organic group.
N represents 0 to 3, and m represents 0 to 3;
Represents an integer, provided that n + m is 4 or less.
The method described in (1) or (2), characterized in that
Law. (6) Before contacting the mixed solution,
Items (1) to (5), wherein the film is subjected to a heat treatment.
The method of any one of the preceding clauses. (7) The substrate is a plastic film
Any one of (1) to (6),
The method described in one. (8) Any one of the above items (1) to (7)
SiO formed by the described method_TwoSeries ceramic coating
film. Polysilazane used in the method of the present invention
Is at least a Si—H bond or an N—H bond in the molecule.
Any polysilazane having the formula: polysilazane alone
Of course, copolymers of polysilazane and other polymers
Or a mixture of polysilazane and other compounds.
You. The polysilazane used may be a chain, cyclic, or
Or those having a cross-linked structure or
Some have multiple structures at the same time.
Alternatively, a mixture can be used. The following are typical examples of polysilazane to be used.
There are compounds represented by the general formula (I).
It is not limited. [0020] Embedded image In the general formula (I), R¹, R^TwoAnd R^ThreeHydrogen
Those having atoms are perhydropolysilazanes,
The production method is described in, for example, Japanese Patent Application Laid-Open No. 60-145903.
Bulletin, D. Seeferth et al. Communicatio
no of Am. Cer. Soc. , C-13, Jan
uary 1983. Has been reported to. These methods
Is obtained by mixing polymers having various structures
Basically, it has a chain and a cyclic part in the molecule.
Including [0022] Embedded image Can be represented by the following chemical formula. Perhide
An example of the structure of lopolysilazane is shown below.
You. [0024] Embedded image In the general formula (I), R¹And R^TwoA hydrogen atom,
R^ThreeA method for producing a polysilazane having a methyl group in
D. Seeyferth et al., Polym. Prepr. A
m. Chem. Soc. , Div. Polym. Che
m,.25, 10 (1984). this
The polysilazane obtained by the method has a repeating unit of-
(SiH_TwoNCH_Three)-Chain polymers and cyclic polymers
And none of them have a crosslinked structure. In the general formula (I), R¹And R^ThreeA hydrogen atom,
R^Two(Hydro) silazane having an organic group on the surface
Is manufactured by D. Seeyferth et al., Polym. Pr
epr. Am. Chem. Soc. Div. Poly
m. Chem,. 25, 10 (1984), JP-A-61-61
-89230. These methods
The resulting polysilazane includes-(R^TwoSiHNH)
A ring having a polymerization degree of 3 to 5, with-being a repeating unit
Or (R^ThreeSiHNH)_x[(R^TwoS
iH)_1.5N]_1-x(0.4 <X <1)
Some molecules have both a chain structure and a cyclic structure in the molecule.
You. In the general formula (I), R¹A hydrogen atom, R^Twoas well as
R^ThreeA polysilazane having an organic group at¹And R^Two
An organic group, R^ThreeHaving a hydrogen atom is represented by-(R¹R
^TwoSiNR^Three)-Is a repeating unit, and the degree of polymerization is mainly
It has three to five ring structures. The polysilazane used in the present invention includes:
Other than the general formula (I), D.I. Seeferth et al.
Communication of Am. Cer.
Soc. , C-132, July 1984. Reported to
Polyorgano having a cross-linked structure in the molecule
There is (hydro) silazane. An example is as follows
is there. [0029] Embedded image [0030] Also, a report is given in JP-A-49-69717.
R like¹Six_Three(X: halogen) ammonia
Polysilazane having crosslinked structure obtained by decomposition
(R¹Si (NH)_xOr R¹Six_ThreeAnd R^Two
_TwoSix_TwoThe following obtained by co-ammonium decomposition of
Use of polysilazane having a structure as a starting material
Can be. [0031] Embedded imageFurther, the following structure (wherein the side chain metal source)
The metal atom may be cross-linked)
Polymetallosilazane containing
Can be. [0033] Embedded image Further, Japanese Patent Application Laid-Open No. Sho 62-195024 discloses
Polysiloxazan as reported, JP-A-2-8
Polysilazane as reported in US Pat.
JP-A-63-81122, JP-A-63-191832
And JP-A-2-77427.
Una polymetallosilazane, JP-A-1-138108,
JP-A-1-138107, JP-A-1-203429
JP-A-1-203430 and JP-A-4-6383.
No. 3 and Japanese Patent Application No. 3-320167
Modified polysilazane as disclosed in JP-A-2-175
726, JP-A-1-138107, JP-A-5-86
No. 200, JP-A-5-331293 and JP-A-3-3
No. 13326 discloses a copolymerization policy.
Razan can also be suitably used. The polysilazane used is also evident from the above.
As shown in the figure, in which case the cyclic portion
Becomes a terminal group, and when such cyclization is not performed,
Means that the terminal of the main skeleton is R¹, R^Two, R^ThreeSimilar group or water
Can be elementary. The molecular weight of the polysilazane used should be a number average
100 to 50,000, preferably 500 to 10,000
It is. If the molecular weight is too small, the yield is low, and practically
On the other hand, if the molecular weight is too large, the stability of the solution will be reduced.
And a sound film cannot be obtained. A polysilazane film as described above is formed on a substrate.
To achieve this, polysilazane is dissolved in a suitable solvent and
A coating solution can be prepared. Polysilazane
Solvents include, for example, aliphatic hydrocarbons, alicyclic hydrocarbons,
Hydrocarbon solvents such as aromatic hydrocarbons, halogenated meta
, Halogenated ethane, halogenated benzene, etc.
Genated hydrocarbons, aliphatic ethers, alicyclic ethers, etc.
Can be used. As a preferred solvent, chloride
Methylene, chloroform, carbon tetrachloride, bromoform,
Ethylene chloride, ethylidene chloride, trichloroethane,
Halogenated hydrocarbons such as trachloroethane, ethyl acetate
Ter, isopropyl ether, ethyl butyl ether,
Butyl ether, 1,2-dioxyethane, dioxa
Dimethyldioxane, tetrahydrofuran, tetra
Ethers such as hydropyran, pentanehexane, iso
Hexane, methylpentane, heptane, isoheptane,
Octane, isooctane, cyclopentane, methylcycl
Lopentane, cyclohexane, methylcyclohexane,
Benzene, toluene, xylene, ethylbenzene, etc.
Hydrocarbons and the like. When using these solvents
The solubility of polysilazane and the evaporation rate of solvent
For this purpose, two or more solvents may be mixed. The amount (proportion) of the solvent used depends on the application method used.
Selected for better workability, and
Average molecular weight, molecular weight distribution, and structure
Therefore, the solvent in the coating liquid is mixed up to about 90% by weight.
And preferably has a solid content of 10 to 50.
It can be mixed in the range of weight%. The coating solution used in the present invention
, A suitable filler may be added as necessary. filling
Examples of agents include silica, alumina, zirconia, mica
And other oxide-based inorganic substances such as silicon carbide and silicon nitride
Fine powder of a non-oxide inorganic substance such as silicon. Ma
Metal powder such as aluminum, zinc, copper etc.
Can also be added. More detailed examples of fillers
For example, silica sand, quartz, novacurite, diatomaceous earth
Lica-based; synthetic amorphous silica; kaolinite, mica, lubricated
Stone, wollastonite, asbestos, calcium silicate
And silicates such as aluminum silicate; glass powder,
Glass sphere, hollow glass sphere, glass flake, foam glass sphere
Glass bodies such as boron nitride, boron carbide, aluminum nitride
, Aluminum carbide, silicon nitride, silicon carbide,
Non-oxides such as titanium boride, titanium nitride and titanium carbide
Inorganic substances; calcium carbonate; zinc oxide, alumina, mug
Metal oxidation of Nessia, titanium oxide, beryllium oxide, etc.
Materials: barium sulfate, molybdenum disulfide, tangs disulfide
Ten, carbon fluoride and other inorganic substances; aluminum, bronze
Metal powders such as lead, lead, stainless steel, zinc, etc .;
Carbon black, coke, graphite, pyrolytic carbon, hollow
And carbon bodies such as carbon balls. The amount of filler added depends on the intended effect of the filler.
Within the range that does not inhibit the reactivity of polysilazane
If so, it can be appropriately selected. Filler addition amount is generally
To 0.05 to 50 parts by weight based on 1 part by weight of polysilazane
Parts, and a particularly preferable addition amount is 0.2 to 3% by weight.
In the range of parts. According to the present invention, a coating as described above
The liquid is applied to the substrate once or twice or more to form a film.
The substrate is not particularly limited.
Desired ones are used from tics and the like. As means for applying the coating liquid,
Coating methods: dipping, roll coating, bar coating, brushing
Coating, spray coating, flow coating and the like are used. Ma
Before application, sand the base, degreasing, blasting, etc.
Surface treatment will improve the adhesion of coating liquid.
Up. In the present invention, the porosities formed by such a method are used.
Heating the lysilazane film is essentially unnecessary.
However, to shorten the drying (solvent removal) time, heating
Processing may be performed. At temperatures substantially below 120 ° C
Heat treatment is sufficient. However, the solvent is the final ceramic
If left in the backing film, the film becomes cloudy or the film becomes smooth.
Therefore, it is preferable that drying is sufficiently performed. What
The heat treatment for drying makes the polysilazane hard.
Although the curing reaction may partially proceed, the curing reaction is not
There is no problem because it is lamic. Therefore, the essence of the present invention
It is not necessary if it is removed, but before the reaction with alkoxysilane
Even if heat treatment to cure part of polysilazane is performed,
The present invention is effective as long as Si-H or NH bonds remain.
is there. According to the method of the present invention, as described above,
After forming the silazane film, the alkoxysila
A reactive mixed solution containing water and water. Alkoxy sila used in the method of the present invention
Is made of SiO by the sol-gel method._TwoOf ceramic coating
Any of the alkoxysilanes commonly used for formation
You can choose. The alkoxy group suitable for the method of the present invention
Run is Si (OR)_Four[Wherein, R is each independently
Alkyl, alkenyl, cycloalkyl, aryl
Group, alkylamino group or alkylsilyl group)
Is an alkoxysilane represented by Preferred R is
Butyl, ethyl, propyl, butyl and isopropyl
It is a phenyl group. Especially preferred alkoxysilane
Is tetramethoxysilane and tetraethoxysilane
is there. In the method of the present invention, R '_nSi (OR)
_4-nWherein R is independently an alkyl group, an alkenyl
Group, cycloalkyl group, aryl group, alkylamino
Or an alkylsilyl group, R 'is each independently
In addition to the above R, a vinyl group, an epoxy group, an amino group,
Represents a acryl group or a mercapto group, and n is 1 to
An organic alkoxysilane represented by the formula:
Is R '_n(RO)_3-nSi-R "-Si (OR)
_3-mR '_m[Wherein, R is each independently an alkyl group,
Lucenyl group, cycloalkyl group, aryl group, alkyl
Represents an amino group or an alkylsilyl group;
Independently, in addition to the above R, a vinyl group, an epoxy group, an amino
R "represents a group, a methacryl group or a mercapto group;
Represents a divalent organic bonding group or -O-, wherein n is 0 to 3, m
Represents an integer of 0 to 3, provided that n + m is 4 or less.
May be used.
Such organic groups R 'and R "
Mic coating is the desired film quality (eg, heat resistance, abrasion resistance,
The person skilled in the art can select an appropriate
Can be. The water (H
_TwoO) includes ordinary ion-exchanged water, industrial water, filtered water,
Etc. can be used. However, the resulting final ceramic
When considering the film quality of the coating, pure water can be used.
preferable. Also, use hydrogen peroxide water instead of water
It is possible. The presence of alkoxysilane and water in the mixed solution
The ratio is, on a volume basis, alkoxysilane / water = 0.01 to
Preferably in the range of 100, more preferably 0.1 to 10
No. If this ratio is less than 0.01, water reaction
And the quality of the resulting ceramic film is
You. On the other hand, if it is larger than 100, the alkoxysilane
The hydrolysis rate becomes slow. Also, changing this ratio
And can control the reactivity of the mixed solution. This mixed solution may be mixed with R ″ OH
Can be contained. here
R ″ is the same as R described above for alkoxysilane.
Groups, i.e., alkyl, alkenyl, cycloal
Kill group, aryl group, alkylamino group or alkyl
Represents a silyl group. Of alcohol in certain mixed solutions
R ”and R of the alkoxysilane are preferably the same.
New, but may be different. Contains alcohol
This promotes the hydrolysis of the alkoxysilane.
And the reactivity of the solution is increased. The alkoxysilane in the mixed solution and the
The proportion of coal is determined based on the volume of alkoxysilane /
Alcohol = 100-0.01, more preferably 10-
A range of 0.1 is preferred. This ratio is greater than 100
In addition, the decomposition of alkoxysilane is low, and the reactivity of the solution
Becomes lower. On the other hand, if it is smaller than 0.01,
And silazane react mainly to deteriorate the film quality. Ma
Also, change this ratio as in the case of water described earlier.
Can also control the reactivity of the mixed solution.
Wear. Reactive mixture containing alkoxysilane and water
The solution is prepared by hydrolysis of the alkoxide and polysilazane.
Can contain a catalyst to promote the reaction of
You. Acids and bases are preferred as the catalyst.
Although not particularly limited, examples include hydrochloric acid, sulfuric acid, and hydrofluoric acid.
Acid, nitric acid and their salts, ammonia, ammonium hydroxide
, Ammonium chloride, triethylamine, diethyl
Luamine, monoethanolamine, diethanolamine
, Amines such as triethanolamine, and hydroxyl
Sodium hydroxide, potassium hydroxide, and the like. this
The amount of the acid or base catalyst added was 1 mole of alkoxysilane.
0.0001 to 10 mol%, more preferably 0.1 mol / mol.
001-1.0 mol% is preferable. Similarly, this catalyst addition
The reactivity of the mixed solution can also be controlled by the amount added.
You. According to the method of the present invention,
Mixed solution containing mixed alkoxysilane and water
Is brought into contact with the above polysilazane film by an appropriate method.
You. As a method of contacting, for example, dipping method, spray method,
And the like. This contact allows polysilazane and al
A reaction takes place with the coxysilane, which reacts with SiO2._x
Converted to ceramic of composition. The temperature at the time of this contact (for example, the temperature of the immersion liquid)
At room temperature, room temperature is sufficient.
You may heat to the range below the boiling point of a liquid. Contact time is limited
Although not necessarily specified, it generally takes less than an hour,
Or 1 to 10 minutes. After the step of contacting with the mixed solution, the obtained coating
Combines the drying of the film and the improvement of the film quality, and the
A post-heating step can be performed at the temperature. Polysilazane and alkoxyl according to the present invention
The formation reaction of the ceramic coating during the run is as follows.
I think that the elementary reaction is fundamental. That is,
The alkoxysilane in the mixed solution has the following formula:   ≡Si-OR + H_TwoO-> ≡Si-OH
  + ROH Is hydrolyzed as in
But the following formula:   ≡Si-OH + ≡Si-H-> ≡Si-O
−Si≡ + H_Two   {Si-OH + {Si-NH-Si} --->
≡Si-O-Si≡ + ≡Si-NH_Two Si—H and / or N—H bond of polysilazane
Reacts with SiO to form a film of SiO_xBecome According to the method of the present invention, substantially Si—O
Dense SiO mainly composed of bonds_TwoSystem ceramic coating,
It can be obtained at room temperature in a short time. [0058] The present invention will be described in more detail with reference to the following examples.
I do. [0059]Preparation of coating liquid Coating liquid 1: Tonen perhydropolysilazane Ty
20 of pe-1 (PHPS-1; number average molecular weight 900)
% Xylene solution and prepare it as coating solution 1.
Was. Coating liquid 2: Tonen perhydropolysilazane Ty
20 of pe-1 (PHPS-1; number average molecular weight 900)
Palladium acetate (2)
0.5% xylene (manufactured by NEMC Corporation)
Add 4 grams of solution and add 6 grams of xylene.
The reaction was performed while stirring at 20 ° C. in the atmosphere for 3 hours.
The solution was then concentrated to a 20% strength solution.
Was. The number average molecular weight of this solution was measured by GPC.
970. This solution is called coating solution 2.
Was. [0060]Preparation of immersion liquid (reactive mixed solution) Immersion liquid 1: 200 mL of tetraethoxysilane (TEOS)
And 1000 mL of pure water, 100 mL of ethanol and hydrochloric acid
0.65 grams (0.02 mol% based on TEOS)
The obtained solution was prepared and used as immersion liquid 1. Immersion liquid 2: 200 mL of tetramethoxysilane (TMOS)
And 1000 mL of pure water, 100 mL of methanol and hydrochloric acid
1.0 g (0.02 mol% based on TMOS)
This solution was prepared and used as immersion liquid 2. [0061]Example 1 Coating liquid 1 was washed with a PTFE filter having a pore size of 0.2 μm.
After filtration with a filter, a 0.5 mm thick silicon wafer (2
cm × 2 cm) using a spin coater (2000 rp)
m, 20 seconds), and heat at 120 ° C. for 1 hour in an air atmosphere.
To remove the solvent. At this stage,
When the degree of progress was evaluated by IR, the residual ratio of SiH was 95%.
there were. The evaluation method was as follows. SiH residual ratio (%) = (SiH absorbance after heating / before heating)
Absorbance of SiN) x 100
It is an index of the row, and the smaller the residual SiH ratio
The higher the SiO absorbance, the more ceramics
That you are Here, SiN, SiO and
The characteristic absorption of SiH is about 840, 1100 and 2 respectively.
160cm^-1Was used. The absorbance is Absorbance = 1 og (Io / I) Was calculated. Here, I is the transmittance of the absorption peak, Io
Is the transmittance which is the base of the peak. Next, a silicon wafer containing this film is immersed.
It was immersed in Pickling Solution 1 at room temperature for 1 hour to react. After immersion, liquid
The mixture was heated at 120 ° C. for 5 minutes also for drying. Membrane ceramic
The degree of progress of the oxidation was evaluated by IR.
Rate was 5%. Also, 1100cm^-1Si-O-Si
Due to absorption, 940cm^-1Absorption due to Si-OH
Income, and 3400cm^-1Shows absorption due to OH
Was done. Si-N-Si which is a skeleton structure of polysilazane
Absorption due to the immersion liquid has almost disappeared.
SiO by reaction_xConverted to ceramics
I understand. The ceramic coating thus obtained
And 18 mL of 49% hydrofluoric acid (manufactured by Daikin Industries, Ltd.)
When treated with a mixed solution of 1763 mL of 1% nitric acid,
The chin rate was 1500 ° / min. [0064]Examples 2 to 11 In the same manner as in Example 1, the ceramic under various reaction conditions was used.
The degree of progress of the conversion was evaluated. These reaction conditions and results
These are described in Tables 1 and 2 below, respectively. [0065]Table 1: Reaction conditions Example Coating liquid Drying conditions Immersion liquid Immersion time     1 1 120 ° C, 1 h 1 1 hour     2 1 80 ° C, 1 h 1 1 hour     3 1 room temperature, 1 h 1 1 hour     4 120 ° C, 1 h 1 hour     5 2 80 ° C, 1 h 1 1 hour     6 2 room temperature, 1 h 1 1 hour     7 1 Room temperature, 1 h 25 minutes     82 120 ° C, 1 h 25 minutes     9 280 ° C, 1 h 25 minutes   10 2 room temperature, 1 h 25 minutes   11 2 120 ° C, 5 min 25 minutes [0066]Table 2: Results Example SiH residual rate (%) Etching rate (Å / min)     15 1500     2 0 1460     3 0 1400     40 1450     5 0 1400     6 0 1380     7 0 1400     8 0 1380     9 0 1460   100 0 1470   11 0 1420 From the results shown in Table 2, the above Examples 1 to 1
The ceramic coating obtained in 1 was obtained by a sol-gel method.
SiO_TwoExcellent denseness (etching
). [0068]Comparative Example 1 Coating liquid 1 was applied to a silicon wafer as in Example 1.
To 1000 mL of pure water, ethanol 100
One hour into a solution containing mL and 0.65 grams of hydrochloric acid. Soak
After immersion, the film decomposed and did not remain. [0069]Comparative Example 2 Coating liquid 1 was applied to a silicon wafer as in Example 1.
To 1000 mL of pure water and 100 mL of methanol.
One hour into a solution containing mL and 1.0 gram of hydrochloric acid. Immersion
Later, the membrane decomposed and did not remain. [0070]Comparative Example 3 Coating liquid 2 was applied to silicon wafer in the same manner as in Example 1.
Spin coat on eher and heat in air at 120 ° C for 1 hour
did. The degree of ceramicization of this film was evaluated by IR.
However, the residual ratio of SiH was 85%, which was almost
Had not been converted. Furthermore, the etching rate is
> 5000 ° / min, and the denseness of the film was poor. [0071] According to the present invention, even at low temperatures, especially at room temperature,
It is possible to form a dense ceramic coating,
Various substrates that could not be applied due to the need for heating
Ceramic coating on plastics and plastics)
it can. In addition, the method of the present invention can be performed for a short time without heat treatment.
Simplifies the film forming process and
Efficiency is achieved.

Continuation of the front page (56) References JP-A-5-238827 (JP, A) JP-A-6-47862 (JP, A) JP-A-2-188471 (JP, A) JP-A-61-149226 (JP) JP-A-61-138571 (JP, A) JP-A-55-108473 (JP, A) JP-A-60-179180 (JP, A) JP-A-6-256975 (JP, A) 63-7877 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 1/00-7/26 C09D 101/00-201/10 C04B 41/80-41/91

Claims (1)

(57) Claims 1. A polysilazane film having a Si-H bond and / or an N-H bond in a molecule is formed on a substrate,
A method for forming a SiO ₂ -based ceramic coating, comprising contacting a mixed solution containing alkoxysilane and water with the film.