JPH06122852A - Coating composition and method for coating using the same - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of giving crack-free and dense coating films excellent in resistance to heat, wear and corrosion when baked at relatively low temperatures, containing an adduct produced by adding glycidol to a specific polysilazane. CONSTITUTION:The objective composition containing a glycidol-added polysilazane 200-500000 in number-average molecular weight which can be obtained by reacting (A) a polysilazane 100-50000 in number-average molecular weight having the main skeleton made up of unit of the formula (R<1>-R<3> are each H, alkyl, alkenyl, etc.; where, at least one of them being H) with (B) glycidol at the weight ratio A/B of 0.001-2. It is preferable that the reaction between the components A and B be made in a solvent such as pyridine or methylpyridine in an inert gas atmosphere such as nitrogen gas at <=150 deg.C for 1-50hr at normal pressure. It is recommended that this composition by prepared by dissolving the glycidol-added polysilazane in a solvent (pref. methylene chloride).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition containing a modified polysilazane as an essential component and capable of forming a coating film excellent in heat resistance, abrasion resistance and corrosion resistance, and a coating method using the same.

[0002]

2. Description of the Related Art Organic paints are not sufficient for obtaining high heat resistance, wear resistance and corrosion resistance, and ceramic coatings are used. Conventionally, as a method of forming a ceramic coating, PVD (sputtering method, etc.),
Known are CVD, sol-gel method, polytitanocarbosilane-based paint, poly (dicyl) silazane-based paint, polysilazane-based paint, polymetallosilazane-based paint, and the like.

[0003]

The above-mentioned ceramics-based coating methods are known, but all have problems. That is, the PVD and CVD methods are expensive. In the sol-gel method, the required firing temperature is as high as 500 ° C or higher. Low-temperature baking (4
The surface strength at 00 ° C. or lower) is insufficient. Those using a poly (disyl) silazane-based polymer are difficult to apply and cracks occur. Polysilazane and polymetallosilazane coatings can be fired at 200 to 500 ° C, but firing at less than 300 ° C does not necessarily give good film quality.

Therefore, the present invention solves the problems in the prior art as described above, heat resistance by low temperature (50 ° C. to 300 ° C.) firing or by holding at a temperature of less than 50 ° C. without firing, To provide a coating composition having excellent wear resistance and corrosion resistance, which gives a dense coating film without cracks, and a construction method therefor, in particular, electronic components, plastics, etc. The purpose is to enable coating on.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that when a coating film of the adduct is baked in air by adding glycidol to polysilazane. It was found that the curing reaction of (1) was accelerated and a good coating was formed at a lower firing temperature than before.

Thus, according to the present invention, the general formula (I):

[0007]

[Chemical 2]

(However, R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups in which the group directly bonded to silicon is carbon. , An alkylsilyl group, an alkylamino group, and an alkoxy group, provided that R ¹ ,
At least one of R ² and R ³ is a hydrogen atom. )
A polyglycazane having a main skeleton composed of units represented by the formula (1) and having a number average molecular weight of 100 to 50,000 and glycidol are reacted, and the glycidol / polysilazane weight ratio is within the range of 0.001 to 2 and the number average molecular weight is about 200. ~
Provided is a coating composition containing at least 500,000 glycidol-added polysilazanes.

The glycidol-added polysilazane used as an essential component of the coating composition in the present invention is prepared by reacting hydrogen atoms bonded to at least a part of silicon atoms in the entire polysilazane skeleton with glycidol.
It is a compound characterized in that it has a side chain group in which a silicon atom in polysilazane is condensed with glycidol, or has a cyclic or crosslinked structure.

In the reaction between polysilazane and glycidol, a dehydrogenative condensation reaction occurs between the OH group of glycidol and the SiH group of polysilazane, and Si--O--C is obtained as follows.
A bond is formed.

[0011]

[Chemical 3]

Further, depending on the reaction conditions, a bond is formed between the carbon at the 3-position or 2-position of glycidol and the NH group of polysilazane to open the epoxy group, and the resulting OH group and SiH group of polysilazane. In some cases, a dehydrogenative condensation reaction may occur between them to form a Si—O—C bond. In this case, a cross-linking structure is formed between the polysilazane molecules via the glycidol molecule as described below.

[0013]

[Chemical 4]

The number average molecular weight of the glycidol-added polysilazane used in the present invention is 200,000 to 500,000, preferably 50.
It is within the range of 0 to 10,000. The method for producing the glycidol-added polysilazane used in the present invention comprises reacting the polysilazane and glycidol in a solvent or a solvent and in an atmosphere inert to the reaction.

The polysilazane to be used may be a polysilazane having at least a Si--H bond or an N--H bond in the molecule. Not only polysilazane alone, but also a copolymer of polysilazane and another polymer or polysilazane and other It can also be used as a mixture with the compound of. The polysilazanes to be used include those having a chain structure, a cyclic structure, or a crosslinked structure, or those having a plurality of these structures simultaneously in the molecule, and these can be used alone or in a mixture.

The following are typical examples of polysilazane to be used, but the polysilazane is not limited thereto. The ^one having hydrogen atoms in R ¹ , R ² and R ³ in the general formula (I) is perhydropolysilazane, and its production method is described in, for example, JP-A-60-145903 and D. Seyf.
erth et al Communication of Am.Cer.Soc., C-13, January
1983. Has been reported to. What is obtained by these methods is a mixture of polymers having various structures, but basically contains a chain portion and a cyclic portion in the molecule,

[0017]

[Chemical 5]

It can be represented by the chemical formula: An example of the structure of perhydropolysilazane is as follows.

[0019]

[Chemical 6]

In the general formula (I), R ¹ and R ² are hydrogen atoms,
A method for producing polysilazane having a methyl group in R ³ is described in D.
Seyferth et al. Polym.Prepr., Am.Chem.Soc., Div.Polym.Che
m ,. 25 , 10 (1984). The polysilazane obtained by this method has a repeating unit of −
(SiH ₂ NCH ₃₎ - is a chain polymer and a cyclic polymer, either no cross-linked structure.

In the general formula (I), R ¹ and R ³ are hydrogen atoms,
A method for producing a polyorgano (hydro) silazane having an organic group in R ² is described in D. Seyferth et al., Polym.Prepr., Am.Chem.Soc.,
Div. Polym. Chem., 25 , 10 (1984), JP-A-61.
-89230. Polysilazanes obtained by these methods include-(R ² SiHNH)
-Having a cyclic structure having a degree of polymerization of 3 to 5 as a repeating unit, or (R ³ SiHNH) _x [(R ² S
iH) _1.5 N] _1−X (0.4 <x <1) has a chain structure and a cyclic structure at the same time in the molecule.

The general formula (I) a hydrogen atom in R ^1, polysilazane having an organic group in R ² and R ³ also, R ¹ and R ²
An organic group for R ³ and a hydrogen atom for R ³ is — (R ¹ R ²
SiNR ³ ) -is a repeating unit and the degree of polymerization is mainly 3
It has a cyclic structure of ~ 5. Among the polysilazanes used next, typical examples other than those of the general formula (I) will be given.

Among the polyorgano (hydro) silazanes are D. Seyferth et al. Communication of Am. Cer. Soc., C-1.
32, July 1984. There are also those having a cross-linked structure in the molecule as reported in. An example is as follows.

[0024]

[Chemical 7]

Further, polysilazane (R having a crosslinked structure obtained by ammonia decomposition of R ¹ SiX ₃ (X: halogen) as reported in JP-A-49-69717 (R
¹ Si (NH) _x ), or R ¹ SiX ₃ and R ² ₂ S
Polysilazane having the following structure obtained by co-ammonia decomposition of iX ₂ can also be used as a starting material.

[0026]

[Chemical 8]

The polysilazane to be used has a main skeleton composed of the unit represented by the general formula (I) as described above, but the unit represented by the general formula (I) may be cyclized as is apparent from the above. In that case, the cyclic portion serves as a terminal group, and when such cyclization is not carried out, the terminal of the main skeleton can be a group similar to R ¹ , R ² and R ³ or hydrogen.

There are no particular restrictions on the molecular weight of the polysilazane to be used, and any available polysilazane can be used. However, in view of reactivity with glycidol, R ¹ in the formula (I),
R ² and R ³ are preferably groups having small steric hindrance. That is, R ¹ , R ² and R ³ are hydrogen atoms and C _{1 to} C
The alkyl group of ₅ is preferable, and a hydrogen atom and a C _{1 to} C ₂ alkyl group are more preferable.

The mixing ratio of polysilazane and glycidol is such that the glycidol / polysilazane weight ratio is 0.001 to 2, preferably 0.01 to 1, and more preferably 0.05 to 0.5. To be added. If the amount of glycidol added is increased beyond this range, the molecular weight of polysilazane increases too much to cause gelation, and if it is too small, no sufficient effect can be obtained.

Although the reaction can be carried out without solvent,
Compared to the case of using an organic solvent, it is generally preferable to use an organic solvent because it is difficult to control the reaction and a gelled substance may be generated. As the solvent, aromatic hydrocarbons, aliphatic hydrocarbons, hydrocarbon solvents of alicyclic hydrocarbons, halogenated hydrocarbons, aliphatic ethers, alicyclic ethers, and aromatic amines can be used. Preferred solvents include, for example, benzene, toluene, xylene, methylene chloride, chloroform, n-hexane, ethyl ether, tetrahydrofuran, pyridine, methylpyridine and the like, and particularly preferred solvents include pyridine and methylpyridine. Further, it is necessary to carry out the reaction in an atmosphere inert to the reaction, for example, in an atmosphere of nitrogen, argon or the like. When the reaction is carried out in an oxidizing atmosphere such as air, oxidation of the raw material polysilazane and glycidol or Hydrolysis occurs, which is not preferable.

The reaction temperature can be varied over a wide range. For example, when an organic solvent is used, it may be heated to a temperature below the boiling point of the organic solvent, but in order to obtain a solid having a high number average molecular weight. Alternatively, the reaction can be carried out by subsequently heating the organic solvent to a boiling point or higher to distill off the organic solvent. The reaction temperature is generally preferably 150 ° C. or lower in order to prevent excessive ring opening of the epoxy group in glycidol and gelation of polysilazane due to it.

The reaction time is not critical, but is usually 1
It is about 50 hours. It is generally preferable to carry out the reaction at around normal pressure. In the present invention, in order to prepare a coating composition using the glycidol-added polysilazane, usually, the glycidol-added polysilazane may be dissolved in a solvent.

Examples of the solvent include aliphatic hydrocarbons, alicyclic hydrocarbons, hydrocarbon solvents of aromatic hydrocarbons, halogenated hydrocarbons such as halogenated methane, halogenated ethane and halogenated benzene, aliphatic ethers and fats. Ethers such as cyclic ethers can be used. Preferred solvents are halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, bromoform, ethylene chloride, ethylidene chloride, trichloroethane and tetrachloroethane, ethyl ether,
Ethers such as isopropyl ether, ethylbutyl ether, butyl ether, 1,2-dioxyethane, dioxane, dimethyldioxane, tetrahydrofuran, tetrahydropyran, pentanehexane, isohexane, methylpentane, heptane, isoheptane, octane, isooctane, cyclopentane, methylcyclopentane And hydrocarbons such as cyclohexane, methylcyclohexane, benzene, toluene, xylene and ethylbenzene.

When using these solvents, two or more kinds of solvents may be mixed in order to adjust the solubility of the glycidol-added polysilazane and the evaporation rate of the solvent. The amount (ratio) of the solvent used is selected so as to improve the workability depending on the coating method adopted, and it depends on the average molecular weight, the molecular weight distribution, and the structure of the glycidol-added polysilazane.
It can be mixed up to about 10% by weight, preferably 10 to
It is possible to mix in the range of 50% by weight.

The solvent concentration varies depending on the average molecular weight of the glycidol-added polysilazane, the molecular weight distribution, and its structure, but good results are usually obtained in the range of 0 to 90% by weight. Further, in the present invention, a suitable filler may be added if necessary. Examples of the filler include fine powders of oxide-based inorganic materials such as silica, alumina, zirconia, and mica, or non-oxide-based inorganic materials such as silicon carbide and silicon nitride. Depending on the application, it is also possible to add metal powders such as aluminum, zinc and copper. More specifically, examples of fillers include silica-based materials such as silica sand, quartz, novaculite, and diatomaceous earth: synthetic amorphous silica: kaolinite, mica, talc, wollastonite, asbestos, calcium silicate, aluminum silicate. Silicates such as: glass powder, glass spheres, hollow glass spheres, glass flakes, foam glass spheres, etc. glass bodies: boron nitride, boron carbide, aluminum nitride, aluminum carbide, silicon nitride, silicon carbide, titanium boride, nitride Non-oxide inorganic substances such as titanium and titanium carbide: calcium carbonate: zinc oxide,
Alumina, magnesia, titanium oxide, beryllium oxide and other metal oxides: barium sulfate, molybdenum disulfide, tungsten disulfide, carbon fluoride and other inorganic substances: aluminum, bronze, lead, stainless steel, zinc and other metal powders: carbon black, Examples thereof include carbon bodies such as coke, graphite, pyrolytic carbon, and hollow carbon spheres.

These fillers have various shapes such as needle-like shape (including whiskers), granular shape, and scale-like shape, either alone or in 2 pieces.
A mixture of two or more species can be used. Further, it is desirable that the particle size of these fillers is smaller than the film thickness that can be applied at one time. Further, the amount of the filler added is 0.05 parts by weight to 1 part by weight of the silicon alkoxide-added polysilazane.
It is in the range of 10 parts by weight, and a particularly preferable amount of addition is 0.2.
The range is 3 to 3 parts by weight. Further, the surface of the filler may be surface-treated by a coupling agent treatment, vapor deposition, plating or the like for use.

The coating composition may include various pigments, leveling agents, defoaming agents, antistatic agents, ultraviolet absorbers, pH adjusters, dispersants, surface modifiers, plasticizers, and drying accelerators as needed. Alternatively, anti-flow agents may be added. According to the invention,
In the same manner, there is provided a coating method using the coating composition as described above, which comprises applying the coating composition to a substrate once or more than once and then baking the silicon-nitrogen-containing material. It is characterized in that a coating film made of oxygen-based or silicon-nitrogen-oxygen-carbon ceramics is formed.

The present invention also provides a coating method characterized in that the properties of the coating film are improved by keeping the coating film fired as described above at a temperature of less than 50 ° C. for a long time. Further, in the present invention, after the coating composition as described above is repeatedly applied to the substrate once or twice or more, the coating film is kept for a long time under the condition of less than 50 ° C. to obtain silicon-nitrogen-oxygen or silicon-nitrogen- Provided is a coating method, which comprises forming a coating film made of oxygen-carbon ceramics.

The base on which the coating composition is applied is not particularly limited and may be any of metal, ceramics, plastics and the like. As a coating means for coating, a usual coating method, that is, dipping, roll coating, bar coating, brush coating, spray coating, flow coating or the like is used. Further, if the substrate is sanded, degreased, and surface-treated with various blasts before coating, the adhesion performance of the coating composition is improved.

After being coated by such a method and sufficiently dried, it is heated and baked. By this calcination, the glycidol-added polysilazane is crosslinked, condensed, or, depending on the calcination atmosphere, oxidized and hydrolyzed to be hardened to form a tough coating. Although the above firing conditions vary depending on the molecular weight and structure of the glycidol-added polysilazane, it is 0.5-10 ° C.
Baking at a temperature in the range of 50 ° C. to 1000 ° C. at a slow heating rate of / min. The preferred firing temperature is 50 ° C to 300 ° C.
Is the range. The firing atmosphere may be in the air, an inert gas, or the like, but the air is more preferable.
Oxidation of glycidol-added polysilazane by hydrolysis in air or hydrolysis by steam coexisting in air progresses, resulting in a tough coating mainly composed of Si-O bond or Si-N bond at the above low baking temperature. Can be formed.

Depending on the type of glycidol-added polysilazane to be coated, the conversion to ceramics may be incomplete under limited firing conditions. In this case, the coating film after firing may be treated at a temperature lower than 50 ° C. for a long time. Hold time,
It is possible to improve the properties of the coating film. In this case, the holding atmosphere is preferably air, and more preferably wet air having an increased water vapor pressure. The holding time is not particularly limited, but 10 minutes or more and 30 days or less is practically appropriate. The holding temperature is not particularly limited, but 0 ° C or more and less than 50 ° C is practically appropriate.
Of course, holding at 50 ° C or higher is also effective,
In the text, the heating operation at 50 ° C. or higher is defined as “calcination”. That is, it is also effective to bake at a certain temperature for a certain period of time and then lower the temperature to, for example, 50 ° C. and bake for a long time.

By this holding in air, oxidation of glycidol-added polysilazane or hydrolysis by steam coexisting in air further progresses, conversion to ceramics is completed, and a tougher coating with improved properties is obtained. A covering film can be formed. According to the above method, the firing temperature can be lowered and various problems caused by the high firing temperature can be alleviated.

Further, depending on the type of glycidol-added polysilazane to be coated, baking at 50 ° C. or higher is not performed at all, and the coating film after coating is kept for a long time at a temperature of less than 50 ° C. It is possible to improve. In this case, the holding atmosphere is preferably air, and more preferably wet air having an increased water vapor pressure. The holding time is not particularly limited, but 10 minutes or more and 30
Within a day is realistically appropriate. The holding temperature is not particularly limited, but 0 ° C or more and less than 50 ° C is practically appropriate. Here, it is naturally effective to hold at 50 ° C. or higher, but in the present text, the heating operation at 50 ° C. or higher is defined as “baking”. This retention in air promotes oxidation of the glycidol-added polysilazane or hydrolysis by steam coexisting in the air to complete conversion to ceramics, resulting in a toughness mainly composed of Si-O bond or Si-N bond. It is possible to form a different coating film. According to the above method, various problems caused by the high firing temperature can be significantly reduced, and in some cases, conversion to ceramics near room temperature becomes possible.

[0044]

[Production of raw material perhydropolysilazane]

A four-necked flask having an inner volume of 11 was equipped with a gas blowing tube, a mechanical stirrer, and a dewar condenser. After replacing the inside of the reactor with deoxygenated dry nitrogen, 490 ml of degassed dry pyridine was put into a four-necked flask, and this was ice-cooled. Next, 51.6 g of dichlorosilane was added to produce a white solid adduct (SiH ₂ Cl · 2C ₅ H ₅ N). The reaction mixture was ice-cooled, and while stirring, 51.0 g of purified ammonia was bubbled through a sodium hydroxide tube and an activated carbon tube, followed by heating at 90 ° C.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry pyridine, and then filtered under a nitrogen atmosphere to obtain 850 ml of a filtrate. The solvent was removed from the filtrate (5 ml) by distillation, and 0.1 g of a resinous solid perhydropolysilazane was obtained. The number average molecular weight of the obtained polymer was measured by the freezing point depression method (solvent: dry benzene),
It was 1120. The IR (infrared absorption) spectrum (solvent: dry o-xylene; concentration of perhydropolysilazane: 10.2 g / 1) shows a wave number (cm ⁻¹ ) 3340 (apparent extinction coefficient ε = 0.5571 g ⁻¹ cm ^{− 1} ) and 117
Absorption based on NH of 5; S of 2160 (ε = 3.14)
iH-based absorption; SiH and Si from 1024 to 820
It showed absorption based on NSi. ^{The 1} H NMR (proton nuclear magnetic resonance) spectra (60 MHz, solvent CDCl ₃ / reference material TMS) all show broad absorption.
That is, δ4.8 and 4.4 (br., SiH); 1.5
Absorption of (br., NH) was observed.

Comparative Example 1 (Evaluation of Ceramization during Firing) Generally, when polysilazane is fired, Si—R ₁ and N—R ₂ (R ₁ and R ₂ represent a hydrogen atom or an alkyl group) bond is broken. And S
Formation of i-N and Si-O bonds (the latter is limited to firing in an oxidizing atmosphere) occurs, polysilazane is silicon nitride,
Converts to ceramics such as silicon oxynitride and silica. This process is called ceramization. In this Comparative Example or Example, since the polysilazane was mainly changed to silica because the firing was performed in the air atmosphere, the semi-quantitative evaluation of the progress of the ceramization was performed by the IR method.

The polysilazane obtained in Reference Example 1 was diluted with o-xylene to a concentration of 20% by weight. This solution was applied (2000 rpm, 20 seconds) to a silicon wafer having a diameter of 5 inches and a thickness of 0.5 mm by using a spin coater to obtain a coating film having a film thickness of about 0.5 micron. The IR spectrum of this coating film is shown in Reference Figure 1. (Spectrum) Then, when this coating film was heated at 200 ° C. for 1 hour in the atmosphere, I
The R spectrum changed as shown in the same figure. Here, the residual rate of SiH and the SiO / SiN ratio were determined by the following methods.

SiH residual rate = (SiH absorbance after heating /
(SiN absorbance before heating) × 100 (%) SiO / SiN ratio = SiO absorbance after heating / S after heating
iN Absorbance Both numerical values serve as indicators of the progress of ceramization, and the smaller the SiH residual rate and the larger the SiO / SiN ratio, the more advanced the ceramization.

The characteristic absorptions of SiN, SiO, and SiH used here are about 840, 1160, and 2160 cm ^-1 , respectively. The absorbance was calculated by the equation: absorbance = log (I _o / I). (See FIG. 1 for the definition of I _o and I) Table 1 shows the obtained SiH residual ratio and SiO / SiN ratio.

(Coating and Evaluation) The polysilazane obtained above was diluted with o-xylene to a concentration of 5% by weight. This coating liquid is applied to SUS304 substrate (70 mm x
After being coated on a surface of 30 mm × 1 mmt) with a brush, it was heated in a drying furnace under an air atmosphere. Heating temperature is 200 ℃,
The heating rate was 20 ° C./minute for 60 minutes. As a result, a coating having a thickness of about 1.0 micron was obtained.

Table 1 shows the results of the appearance, pencil hardness, and cross-cut peeling test of this coating measured according to the following inspection methods. The inspection method adopted is as follows. A) Appearance: Visually inspect for cracks, color tones, and other defects in the coating film. B) Pencil hardness: According to JIS K5400.

C) Cross-cut peeling test (adhesion): A 1 mm square material cut on the coating film with a steel knife
Make 00 pieces and cellophane tape on it (Sekisui Chemical Co., Ltd.)
After sticking, the cellophane tape is evaluated by the number of squares remaining when it is strongly peeled in the upward 90 ° direction. Comparative Example 2 The heating temperature of the coating film for IR evaluation and the coating product was 300 ° C.
Ceramics conversion and coating were evaluated by the same method as in Comparative Example 1 except for the above. The change in IR spectrum is shown in Reference Figure 1 (spectrum), and the results of both evaluations are shown in Table 1.

Comparative Example 3 Both the coating film for IR evaluation and the heating temperature of the coating were 10
Using the same method as in Comparative Example 1 except that the temperature was 0 ° C., ceramization and coating were evaluated. The evaluation results are shown in Table 1. Example 1 (Synthesis of glycidol-added polysilazane) A dry pyridine solution of the perhydropolysilazane obtained in Reference Example 1 (1
0% by weight) 100 ml was placed in a reaction vessel having an internal volume of 300 ml, 20 g of a dry pyridine solution (5% by weight) of glycidol (manufactured by Kanto Kasei Co., Ltd.) was added, the air in the vessel was replaced with nitrogen, and then a closed system was prepared. The reaction was carried out while stirring at 20 ° C. for 2 hours. After completion of the reaction, 100 ml of dry o-xylene was added, and the solvent was removed at a pressure of 3 to 5 mmHg and a temperature of 30 to 50 ° C. to obtain 10.9 g of a colorless viscous liquid. This liquid was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents.

The number average molecular weight of this viscous liquid was 1,400 as measured by GPC. Also, I
As a result of R spectrum analysis, it was confirmed that CH-based absorption at wave numbers (cm ⁻¹ ) 2960, 2940, and 2840 appeared compared to before the reaction with glycidol. Furthermore, as a result of ¹ NMR spectrum (CDCl ₃ ) analysis, δ
= 2.7, 2.8, 3.1, 3.7, 4.1 absorptions were newly observed. Absorption of these absorption 3.7 and 4.1 are based on Si-O-CH _2, it can be seen that glycidol from this it was added to the polysilazane.

(Evaluation of ceramics and coating)
With respect to the glycidol-added polysilazane, ceramization and coating were evaluated by the same method as in Comparative Example 1 except that the heating temperature of the coating film for IR evaluation and the coating was 100 ° C. The results are shown in Table 1. Example 2 The heating temperature of the coating film for IR evaluation and the coating product was 200 ° C.
Ceramics conversion and coating were evaluated by the same method as in Example 1 except for the above. The change in IR spectrum is shown in Reference Figure 1 (spectrum), and the results of both evaluations are shown in Table 1. The IR spectrum shows that the polysilazane was converted into a state very close to silica by heating at 200 ° C.

Example 3 The coating material for IR evaluation and the coating material were heated at 300 ° C.
Ceramics conversion and coating were evaluated by the same method as in Example 1 except for the above. The results are shown in Table 1. Example 4 The coating film for IR evaluation after heating and the coating material obtained in Example 1 were each kept at 20 ° C. in the atmosphere for 5 days, and then ceramization and coating were evaluated. The results are shown in Table 1.

Example 5 The heated coating film for IR evaluation and the coating product obtained in Example 2 were each kept at 20 ° C. in the atmosphere for 1 day, and then ceramization and coating were evaluated. The results are shown in Table 1. Example 6 100 ml of the dry pyridine solution of perhydropolysilazane (10% by weight) obtained in Reference Example 1 was placed in a reaction vessel having an inner volume of 300 ml, and a dry pyridine solution of glycidol (manufactured by Kanto Kasei Co., Ltd.) (5% by weight) was added. ) 30 g was added and the air in the container was replaced with nitrogen, and then the reaction was carried out while stirring in a closed system at 20 ° C. for 2 hours. After completion of the reaction, 100 ml of dry o-xylene was added, and the solvent was removed at a pressure of 3 to 5 mmHg and a temperature of 30 to 50 ° C. to obtain 11.4 g of a colorless viscous liquid. This liquid was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents.

The number average molecular weight of this viscous liquid was 1750 as measured by GPC. Also, I
As a result of R spectrum analysis, it was confirmed that CH-based absorption at wave numbers (cm ⁻¹ ) 2960, 2940, and 2840 appeared compared to before the reaction with glycidol. Furthermore, as a result of ¹ NMR spectrum (CDCl ₃ ) analysis, δ
= 2.7, 2.8, 3.1, 3.7, 4.1 absorptions were newly observed.

The glycidol-added polysilazane was made into ceramics and the coating was evaluated by the same method as in Example 1. The results are shown in Table 1. Example 7 The heating temperature of the coating film for IR evaluation and the coating product was 200 ° C.
Ceramics conversion and coating were evaluated by the same method as in Example 6 except for the above. The results are shown in Table 1.

Example 8 The coating film for IR evaluation after heating and the coating product obtained in Example 6 were each kept at 20 ° C. in the atmosphere for 1 day, and then ceramization and coating were evaluated. The results are shown in Table 1. Example 9 The glycidol-added polysilazane obtained in Example 6 was used.
-Diluted with xylene to a concentration of 20% by weight. This solution is coated on a silicon wafer having a diameter of 5 inches and a thickness of 0.5 mm using a spin coater (2000 rpm, 20 seconds).
Then, a coating film having a film thickness of about 0.5 micron was obtained. This coating 2
The temperature was maintained at 0 ° C. in the atmosphere for 5 days, and then the ceramization was evaluated by the IR method. The results are shown in Table 1.

In addition, the same glycidol-added polysilazane
-Dilute with xylene to a concentration of 5% by weight and apply this coating solution to SUS304 substrate (70 mm x 30 mm x 1 mm
After applying with a brush on the surface of t), 5 at 5 ℃ in the atmosphere
After holding for a day, the coating film was evaluated by the method described above. The results are shown in Table 1. Example 10 100 ml of a dry pyridine solution of perhydropolysilazane obtained in Reference Example 1 (10% by weight) was placed in a reaction vessel having an internal volume of 300 ml, and a dry pyridine solution of glycidol (manufactured by Kanto Kasei Co., Ltd.) (5% by weight) was added. ) 40 g was added and the air in the container was replaced with nitrogen, and then the reaction was carried out while stirring in a closed system at 20 ° C. for 2 hours. After the reaction was completed, 100 ml of dry o-xylene was added, and the solvent was removed at a pressure of 3 to 5 mmHg and a temperature of 30 to 50 ° C. to obtain 11.9 g of a colorless viscous liquid. This liquid was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents.

The number average molecular weight of this viscous liquid was 2,100 as measured by GPC. Also, I
As a result of R spectrum analysis, it was confirmed that CH-based absorption at wave numbers (cm ⁻¹ ) 2960, 2940, and 2840 appeared compared to before the reaction with glycidol. Furthermore, as a result of ¹ NMR spectrum (CDCl ₃ ) analysis, δ
= 2.7, 2.8, 3.1, 3.7, 4.1 absorptions were newly observed.

The glycidol-added polysilazane was made into ceramics and evaluated for coating by the same method as in Example 1. The results are shown in Table 1. Example 11 The glycidol-added polysilazane obtained in Example 10 was diluted with o-xylene to a concentration of 20% by weight. This solution is coated on a silicon wafer having a diameter of 5 inches and a thickness of 0.5 mm using a spin coater (2000 rpm, 20 seconds).
Then, a coating film having a film thickness of about 0.5 micron was obtained. This coating 2
The temperature was maintained at 0 ° C. in the atmosphere for 2 days, and then the ceramization was evaluated by the IR method. The results are shown in Table 1.

In addition, the same glycidol-added polysilazane
-Dilute with xylene to a concentration of 5% by weight and apply this coating solution to SUS304 substrate (70 mm x 30 mm x 1 mm
After applying with a brush to the surface of t), 2 at 20 ° C in the atmosphere.
After holding for a day, the coating film was evaluated by the method described above. The results are shown in Table 1. Comparative Example 4 The heated coating film for IR evaluation and the coated product obtained in Comparative Example 1 were each held at 20 ° C. in the atmosphere for 5 days, and then ceramization and coating were evaluated. The results are shown in Table 1.

Comparative Example 5 The heated coating film for IR evaluation and the coated product obtained in Comparative Example 4 were each kept at 20 ° C. in the atmosphere for 5 days, and then ceramization and coating were evaluated. The results are shown in Table 1. Comparative Example 6 The polysilazane obtained in Reference Example 1 was diluted with o-xylene to a concentration of 20% by weight. This solution was applied (2000 rpm, 20 seconds) on a silicon wafer having a diameter of 5 inches and a thickness of 0.5 mm by using a spin coater to give a film thickness of about 0.5.
A micron coating was obtained. Apply this coating at 20 ℃ in the atmosphere for 5
After being kept for a day, evaluation of ceramization was performed by IR method. The results are shown in Table 1.

The polysilazane was diluted with o-xylene to a concentration of 5% by weight, and this coating solution was added to SUS.
The surface of 304 substrate (70 mm × 30 mm × 1 mmt) was coated with a brush and then kept in the atmosphere at 20 ° C. for 5 days, after which the coating film was evaluated by the method described above. The results are shown in Table 1. From the results of Examples 1 to 11 and Comparative Examples 1 to 6, the coating using the glycidol-added polysilazane was fired at a lower firing temperature or in some cases, as compared with the coating using the non-addition polysilazane. It is obvious that it gives good physical properties.

[0067]

[Table 1]

[0068]

EFFECTS OF THE INVENTION According to the present invention, a coating having excellent heat resistance, abrasion resistance, corrosion resistance, and good adhesion to a substrate can be obtained by firing at a low temperature which has never been used before or without firing. The composition of the present invention is suitable as a surface protective agent for not only metals and ceramics but also plastic materials unsuitable for high temperature treatment and electronic parts. In particular, plastic hard coating agents, synthetic resin films and gas permeation suppressing coating agents for semiconductors, semiconductor protective films and insulating films, such as passivation films, interlayer insulating films, chip coat films, semiconductor sealing agents, liquid crystal displays, etc. It can also be used as a body undercoat film or an alignment film.

[Brief description of drawings]

FIG. 1 is an IR spectrum diagram in which ceramics are evaluated in Examples.

Claims (4)

[Claims] 1. Mainly represented by the general formula (I): (However, R ¹ , R ² and R ³ are each independently a hydrogen atom,
An alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups in which the group directly bonded to silicon is carbon, an alkylsilyl group, an alkylamino group, and an alkoxy group. However, at least one of R ¹ , R ² and R ³ is a hydrogen atom. ), Which has a main skeleton composed of units represented by the formula (1) and has a number average molecular weight of 100 to 50,000 and glycidol are reacted with each other, and the glycidol / polysilazane weight ratio is in the range of 0.001 to 2 and the number average molecular weight is about A coating composition containing at least 200,000 to 500,000 glycidol-added polysilazanes. 2. The coating composition according to claim 1 is applied to a substrate once or twice or more, and then at 50 ° C.
A coating method which comprises firing at the above temperature to form a coating film made of silicon-nitrogen-oxygen system or silicon-nitrogen-oxygen-carbon system ceramics. 3. The baked coating film according to claim 2 at 50 ° C.
A coating method, characterized in that the property of the coating film is improved by holding it under the condition of less than a long time. 4. The coating composition according to claim 1 is repeatedly applied to a substrate once or twice or more, and then the coating film is kept at a temperature of less than 50 ° C. for a long time to obtain silicon-nitrogen-oxygen or silicon. -A coating method comprising forming a coating film made of nitrogen-oxygen-carbon ceramics.