JP2003139698A - Method for evaluating silica film and forming body covered with silica - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming body coated with silica that can quantitatively evaluate the silica conversion rate in polysilazane, and can avoid excessive silica conversion treatment to required performance and can expand the type of base that can be coated and can reduce manufacturing costs by creating a polysilazane film having a silica conversion rate suited for the prevention of contamination and hydrophilic properties by the evaluation method. SOLUTION: In the method for evaluating a silica film, the silica conversion rate of perhydropolysilazane and the performance of the silica film are evaluated with the value of Y that is expressed by Y=B/A as an index when the absorbance of SiO in the IR spectrum of the film is set to A and the absorbance of SiH is set to B in silica conversion by coating a substrate with perhydropolysilazane. Additionally, contamination prevention performance is given by forming, in the forming body, a paint film that is changed into ceramic so that the value of Y that is an index becomes 3.0 or less in the evaluation method.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for evaluating the silica conversion rate of a silica film synthesized from perhydropolysilazane and its characteristics, and a molded article coated with silica.

[0002]

2. Description of the Related Art Since a resin molding is lightweight,
It is used in a wide range of product fields such as bathtub aprons, bathroom walls, washrooms (waterproof pans), washbasins, washroom counters, tableware, wall materials, flooring, etc. Therefore, the development of a resin molded product having an excellent antifouling function or a molded product having the surface coated with a resin has been earnestly desired.

A general resin molded body or a molded body whose surface is coated with a resin is coated to functionalize the surface such as hydrophilicity and water repellency, that is, by providing hydrophilicity and water repellency. In many cases, the stain resistance is improved, and the surface treatment can be roughly classified into organic paints and inorganic paints.

As organic water-repellent coatings, there are fluorine-based coatings, silicone-based coatings, etc., but none of them have a surface free energy low enough to prevent stains from adhering, and metallic soaps and greasy soiling substances around water. There is a problem that it is not possible to prevent the adhesion of the above, and as a hydrophilic coating, the resin itself does not reach sufficient hydrophilicity, and even if a metal oxide is added to impart hydrophilicity, the addition amount is small. Does not exhibit hydrophilicity.

Inorganic paints include a method of obtaining a silica film by a wet method. A sol-gel method using a coating solution obtained by hydrolyzing a halogenosilane or an alkoxysilane or polysilazane in an oxidizing atmosphere is used. There is a method of converting into silica by firing or treating in a heated steam atmosphere.

In the film formation by the sol-gel method, it is necessary to bake at a high temperature of 400 ° C. or more in order to obtain a dense film, but since the shrinkage during firing is large and cracks are likely to occur, the limit film thickness is small, or There is a problem that it is difficult to apply to a substrate having poor heat resistance such as a resin substrate or a substrate whose surface is coated with resin.

On the other hand, when polysilazane is burned in an oxidizing atmosphere or treated in a steam atmosphere, oxygen is taken into its network instead of nitrogen and converted into silica with an increase in weight, so that shrinkage due to firing is small. It has a feature that it is relatively easy to make a thick film, and since it is a dense ceramic excellent in heat resistance, corrosion resistance, solvent resistance, insulation, abrasion resistance, etc., it flattens the substrate, alkali passivation, It is used for various purposes such as imparting insulating properties and gas barrier properties, hard coatings for films and organic glass, and alignment films for liquid crystal displays. However, since the denseness of the silica film is important in these applications, it was necessary to treat the polysilazane at a high temperature of 200 to 400 ° C. or higher.

However, high density is not always required for applications such as antifouling property and hydrophilic property in housing equipment. In addition, it is preferable to treat the polysilazane film at a temperature lower than the glass transition temperature of the resin in a resin or a molded article whose surface is coated with a resin, and high temperature treatment is not always possible when application to a substrate such as a resin is considered. Absent.

On the other hand, a polysilazane film treated in a temperature range applicable to a resin substrate is usually weakly hydrophilic to water repellent, and it is necessary to perform a hydrophilizing treatment to impart hydrophilicity. If the conversion is too low, the hydrophilicity cannot be maintained for a long time, and if it is too high, sufficient hydrophilicity cannot be obtained.

Regarding the method for evaluating the silica conversion rate and the film characteristics, JP-A-6-122852 discloses that the silica conversion rate is represented by the absorbance of SiO / the absorbance of SiN in the IR spectrum of the polysilazane film. There is no description about the relationship between the silica conversion rate and the characteristics of the silica film,
As the silica conversion rate approaches 100%, it becomes difficult to separate and identify the peak of SiN, and the index becomes infinite. Therefore, it is difficult to show a concrete numerical value as an index of the performance of the film. The problem arises.

[0011]

SUMMARY OF THE INVENTION The first object of the present invention is to make it possible to quantitatively evaluate the silica conversion of polysilazane. In addition, by using the evaluation method to create a polysilazane film with a silica conversion rate suitable for antifouling and hydrophilization, it is possible to avoid excessive silica conversion treatment for the required performance and to apply it. A second object of the present invention is to provide a silica-coated molded article capable of expanding the types of various base materials and reducing the manufacturing cost.

[0012]

The present invention relates to the following. (1) When perhydropolysilazane was applied to a substrate and converted into silica, the silica conversion rate of perhydropolysilazane and the performance of the silica film were measured by measuring the Si spectrum in the IR spectrum of the film.
A method for evaluating a silica film, wherein the absorbance of O is A and the absorbance of SiH is B, and the value of Y represented by the following formula (1) is used as an index.

[Equation 2] (2) Perhydropolysilazane was applied to the substrate, and a coating film which was made into ceramic so that the value of Y was 3.0 or less was formed by the evaluation method described in (1) above to impart stain resistance. Molded body. (3) After applying perhydropolysilazane to the substrate and forming a ceramic film by the evaluation method described in (1) above so that the value of Y is 0.1 or more and 2.0 or less, alkali or A molded product obtained by imparting hydrophilicity by hot water treatment. (4) The molded body is any one of a bathtub, a waterproof pan for bathroom, a bathroom counter, a bathroom wall, a wash counter, a wash bowl, a kitchen counter, a component of a kitchen cabinet, a dish or a dishwasher. ) Or (3)
The molded article according to.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The method for evaluating a silica film according to the present invention and the polysilazane in the silica-coated molded article are
Although a conventionally known polysilazane can be used, it preferably has a repeating unit of the general formula shown in Chemical formula 1,
The number average molecular weight measured by gel permeation chromatography (GPC) using polystyrene as the standard is 1
0 to 50000 cyclic polysilazanes, chain polysilazanes, or mixtures thereof are used.

[0014]

[Chemical 1]

Further, the above polysilazane or silazane polymer is converted into a tertiary amine such as trialkylamine,
A polystyrene obtained by using a basic compound such as a secondary amine having a sterically hindering group or phosphine as a solvent or adding it to a hydrocarbon of a non-basic solvent to carry out a dehydrogenative condensation reaction. A high polymer having a number average molecular weight of 200 to 500,000 measured by gel permeation chromatography (GPC) as a standard is used.

Alternatively, it is a polymer obtained by a modification reaction of an inorganic polysilazane and has a cross-linking bond —NH— or —NH—.
Gel permeation chromatography (GP) having NH- and having an atomic ratio (N / Si) of nitrogen bonded to a silicon atom (N / Si) of 0.8 or more and polystyrene as a standard.
The number average molecular weight of 200 to 50,000 measured by C) is used.

Further, the composition formula (RSiHNH) X [(R
SiH) 1.5N] Y (provided that R is an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups in which the atom directly bonded to Si is carbon, an alkylsilyl group, an alkylamino group, Represents an alkoxy group,
Y is 1-X, and polyorganohydrosilazane represented by 0.4 <X <1> is used.

Further, polysiloxazane containing oxygen, polymetallosilazane obtained by reacting a metal alkoxide, or polyborosilazane obtained by reacting an organic boron compound can also be used.

These various polysilazanes are liquid to solid at room temperature depending on their types. Further, the polysilazane used in the present invention, in terms of adhesion with the resin,
It is preferable to use one having a high content of active hydrogen, which is directly connected to silicon or nitrogen, and is generally 90 or more, preferably 100 to 100 per 100 total atoms of silicon atoms and nitrogen atoms.
Preference is given to using those having 150 active hydrogen atoms.

Coating materials containing polysilazane include organic amines, carboxylic acid anhydrides, isocyanates,
Hardeners such as thiols, carbodiimides, metal alkoxides and metal halides can be added, and nickel, platinum, palladium, aluminum and amine-based catalysts can also be used as catalysts for low temperature ceramics. Further, if necessary, metal powder, ceramic powder, defoaming agent, surfactant, ultraviolet absorber, leveling agent, antistatic agent, dispersant, pigment, thixotropic agent, etc. may be added.

Further, in order to improve water resistance and hot water resistance, a silane coupling agent or the above-mentioned polysilazane containing a silane coupling agent may be applied as a primer on the surface of the substrate in advance.

Silane coupling agents are generally XSiR ₃
Is a compound represented by. X is a functional group capable of reacting with an organic group, and represents a vinyl group, a methacryloxy group, an epoxy group, an amino group, an isocyanate group, a mercapto group, a halogen or the like, and R is a hydrolyzable functional group such as a methoxy group or an ethoxy group. Represents an alkoxy group, a halogen, etc., and is appropriately selected and used.

In the method using the silane coupling agent alone as a primer, the silane coupling agent is previously diluted with an alcohol such as methanol, ethanol, propanol or butanol to a concentration of 0.1 to 50%. After applying by a conventionally known coating method,
A cured film is formed by heating in a temperature range of room temperature to 200 ° C. for 1 to 30 minutes. Then, the above-mentioned polysilazane is applied.

In the method of using the mixture of the silane coupling agent and the polysilazane as the primer, the silane coupling agent and the polysilazane are preliminarily applied to the base material in the range of 10/90 to 90.
After being mixed at a ratio of / 10 and diluted with an organic solvent to a concentration of 0.1 to 50%, the mixture is applied by a conventionally known coating method, and then the temperature is from room temperature to 200 ° C. in the range of 1 to 1: 1.
It heats during 00 minutes, and a hardened film is formed. After that, the above-mentioned inorganic material is applied. In particular, in this method, since the silica film of the primer layer can block water and suppress the hydrolysis of the organic group of the silane coupling agent bonded to the substrate, a large amount of water resistance and hot water resistance can be achieved. It

As the diluent solvent for the polysilazane or the mixture of the polysilane and the silane coupling agent, aliphatic hydrocarbons, halogenated hydrocarbons, alicyclic hydrocarbons,
Aromatic hydrocarbon solvents and ethers can be used alone or as a mixture of two or more, but those that cause the base material to swell or dissolve, or protic solvents such as water and alcohol are not preferred.

As a method for coating the substrate, there are conventionally known coating methods such as spray coating, spin coating, dip coating and flow coating.

The silica conversion rate of the coating film thus formed on the substrate is the value of the index Y represented by the following formula (1), where A is the absorbance of SiO and B is the absorbance of SiH in the IR spectrum of the film. Can be expressed as At this time, IR
As the analysis method, in addition to the general KBr method, attenuated total reflection (A
The TR) method can also be used.

[Equation 3]

The formed coating film is used for a bathtub, a bathtub apron, a bathroom wall, a washroom (waterproof pan), a washbasin, a washroom counter, tableware, wall materials, flooring, and other housing equipment, house building materials, automobile paints, etc. For the purpose of imparting the antifouling function, the Y value used as an index is preferably 3.0 or less, and more preferably 1.0 or less, and the coating film is converted to silica.

The application of the formed coating film is as follows: bathtub, bathtub apron, bathroom wall, washroom (waterproof pan), wash bowl,
Washing counters, tableware, wall materials, flooring and other housing equipment, or for the purpose of imparting anti-contamination functions to housing building materials, automobile paints, etc., especially bathtubs, bathtub aprons, bathroom walls, bathrooms such as bathrooms, kitchens or washbasins In the water-related products, it is necessary to make the surface of the coating film highly hydrophilic to significantly improve the removability of soap residue and oil stains.

In order to make the surface of the polysilazane film hydrophilic as described above, after forming a ceramicized coating film,
It is necessary to immerse in an alkaline solution or hot water, but if the silica conversion of the membrane is too low at this time, the hydrophilicity cannot be maintained for a long time, and if it is too high, sufficient hydrophilicity is obtained. Therefore, the value of Y, which is an index of the silica conversion rate of the polysilazane film, is preferably adjusted to be 0.1 or more and 2.0 or less.

In the present invention, the base material (substrate) to which polysilazane is applied is metal, ceramics, wood, paper,
Various materials such as thermosetting resins and thermoplastic resins can be used. The film forming conditions of polysilazane are such that the base material (substrate) is not affected by the room temperature, usually 10 to 200 ° C. for a certain time, or 50 to 100% high humidity for a certain time. At this time, the temperature under high humidity may be any temperature as long as it is 10 ° C. or higher.

[0032]

EXAMPLES Hereinafter, each of the molded product having stain resistance and the molded product having hydrophilicity according to the evaluation method of the present invention will be described in detail with reference to examples. <Regarding Antifouling Property> (Example 1) Polysilazane NP-110 5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was pre-degreased by spray coating on a base material (unsaturated polyester resin + glass fiber FRP). Was applied to. After coating, it was left in an environment of 30 ° C. and 50% RH for 1 hour. The Y value used as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 0.85, and as shown in Table 1, good antifouling property was exhibited.

(Example 2) Polysilazane NP-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After coating, it was left in an environment of 30 ° C. and 50% RH for 4 days. Coating film formed under these conditions (film thickness 1.0-2.0μ
The value of Y as an index of m) was 0.15, and as shown in Table 1, the adhesion was good in addition to the antifouling property.

(Example 3) Polysilazane NP-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After application, it was left in an environment of 30 ° C. and 50% RH for 10 days. Coating film formed under these conditions (film thickness 1.0-2.0μ
The value of Y, which is an index of m), was 0.09, and as shown in Table 1, the antifouling property, the adhesion property, and the hard coat property were good.

Example 4 Polysilazane NP-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After coating, it was baked at 120 ° C. for 10 minutes. The Y value used as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 0.14, and as shown in Table 1, in addition to antifouling property, adhesiveness and hard coat property Was also good.

Example 5 Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After application, it was left in an environment of 30 ° C. and 50% RH for 24 hours. Coating film formed under these conditions (film thickness 1.0-2.0μ
The value of Y used as the index of m) was 2.8, and as shown in Table 1, good antifouling property was exhibited.

Example 6 Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After coating, it was baked at 140 ° C. for 60 minutes. The Y value as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 0.42, and as shown in Table 1, in addition to antifouling property, adhesiveness and hard coat property Was also good.

Example 7 Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After coating, bake at 140 ℃ for 60 minutes, then 30
It was left for 7 days in an environment of ℃ and 50% RH. Y as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions
Value was 0.04, and as shown in Table 1, in addition to antifouling property, adhesion and hard coat property were also good.

(Comparative Example 1) Polysilazane NP-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After application, it was left for 10 minutes in an environment of 30 ° C. and 50% RH. Coating film formed under these conditions (film thickness 1.0-2.0μ
The value of Y, which is an index of m), was 3.5, and as shown in Table 1, stain resistance could not be expressed.

(Comparative Example 2) Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased by spray coating. After application, it was left for 10 minutes in an environment of 30 ° C. and 50% RH. Coating film formed under these conditions (film thickness 1.0-2.0μ
The value of Y used as the index of m) was 4.0, and as shown in Table 1, good antifouling property could not be expressed.

Reference Example 1 As Reference Example 1, Table 1 shows the surface characteristics of only the base material on which nothing is coated.

Evaluation Method (Test Example 1) The evaluation of the stainproof property was carried out by placing a hair manicure, a hair color, an ink and Tabasco on the coating film at room temperature.
After leaving it for 4 hours, it was lightly washed with a sponge, and the state of adhesion of dirt was visually determined. ◯: Almost all stains were removed Δ: Slight stains remained ×: Smudge remained almost

(Test Example 2) Adhesion to tape was measured according to JIS-K.
The adhesion was evaluated to be -5400. ◯: No peeling Δ: 0 to 10 ×: 10 or more

(Test Example 3) The hard coat property was evaluated by the number of scratches after rubbing 100 strokes at a pressure of 10 kPa using steel wool. O: 0 to 2 Δ: 3 to 10 x 10 More than a book

[0045]

[Table 1]

<Hydrophilicity> (Example 8) Polysilazane NL-110 5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was spray-coated with a base material (unsaturated polyester resin + glass fiber) which had been degreased beforehand. FRP) and dried at room temperature for 24 hours. Coating film formed under these conditions (film thickness 1.
The value of Y, which is an index of 0 to 2.0 μm, was 1.9. After that, the surface was treated with 0.02% sodium hydroxide aqueous solution to make it hydrophilic. Contact angle with water immediately after treatment is 21 °
It showed good hydrophilicity at 32 ° even after standing at room temperature for 10 days.

Example 9 Polysilazane NL-110
5% (xylene solvent) (Clariant Japan Co., Ltd.) was applied to a base material (FRP consisting of unsaturated polyester resin + glass fiber) that had been degreased beforehand by spray coating, and dried in a drying oven at 140 ° C. for 30 minutes. It was The Y value as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 1.4. After that, the surface was treated with 0.02% sodium hydroxide aqueous solution to make it hydrophilic. The contact angle with water immediately after the treatment was 23 °, which was 24 ° even when left at room temperature for 10 days, showing a good hydrophilic property.

Example 10 Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) is applied to a base material (FRP consisting of unsaturated polyester resin + glass fiber) which has been degreased in advance by spray coating, and dried in a drying oven at 140 ° C. for 60 minutes. It was The Y value as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 0.42. Then 0.02%
Was surface-treated with a sodium hydroxide aqueous solution to make it hydrophilic. The contact angle with water immediately after the treatment was 22 °, which was 25 ° even when left at room temperature for 10 days, showing good hydrophilicity.

(Comparative Example 3) Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased in advance by spray coating, and dried at room temperature for 10 minutes. The Y value as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 4.0. After that, the surface was treated with 0.02% sodium hydroxide aqueous solution to make it hydrophilic. The contact angle with water immediately after the treatment was 19 °, but after standing for 10 days at room temperature, it was 89 °.
However, it was impossible to maintain good hydrophilicity for a long time.

Comparative Example 4 Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) was applied to a base material (FRP made of unsaturated polyester resin + glass fiber) that had been degreased in advance by spray coating, and dried at room temperature for 60 minutes. The Y value as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 2.8. After that, the surface was treated with 0.02% sodium hydroxide aqueous solution to make it hydrophilic. The contact angle with water immediately after the treatment was 21 °, but it was 87 after leaving at room temperature for 10 days.
However, it was impossible to maintain good hydrophilicity for a long time.

Comparative Example 5 Polysilazane NL-110
5% (xylene solvent) (manufactured by Clariant Japan Co., Ltd.) is applied to a base material (FRP consisting of unsaturated polyester resin + glass fiber) which has been degreased in advance by spray coating, and dried in a drying oven at 140 ° C. for 60 minutes. Then, it was allowed to stand at room temperature for 2 weeks. The Y value as an index of the coating film (film thickness 1.0 to 2.0 μm) formed under these conditions was 0.03. After that, the surface was treated with 0.02% sodium hydroxide aqueous solution to make it hydrophilic. Contact angle with water immediately after treatment is 7
It was 5 °, and sufficient hydrophilicity was not obtained.

Evaluation Method In order to evaluate the hydrophilicity of the surface of the plastic molded product, the contact angle of water was measured. As the contact angle, a contact angle meter "GA-X150 type" manufactured by Kyowa Interface Science Co., Ltd. was used.

[0053]

According to the present invention, when perhydropolysilazane is applied to a substrate and converted into silica, the silica conversion rate of perhydropolysilazane and the performance of the silica film are determined by
When the absorbance of SiO in the R spectrum is A and the absorbance of SiH is B, evaluation and evaluation of the Y value represented by the formula Y = B / A as an index facilitate the management and grasp of coating film characteristics. . Further, by using the evaluation method to prepare a polysilazane film having a silica conversion rate suitable for antifouling and hydrophilization, it is possible to omit an excessive silica conversion treatment for the required performance and the treatment conditions are It is mild, the number of substrates that can be applied is increased, the process can be simplified, and the effect of reducing manufacturing costs can be expected.

Claims (4)

[Claims] 1. When silica is converted by coating perhydropolysilazane on a substrate, the silica conversion rate of perhydropolysilazane and the performance of the silica film are represented by the absorbance A of SiO and the absorbance B of SiH in the IR spectrum of the film. And a method of evaluating a silica film, wherein the value of Y represented by the following formula (1) is evaluated as an index. [Equation 1] 2. A substrate is coated with perhydropolysilazane, and a ceramic coating film is formed by the evaluation method according to claim 1 so that the Y value is 3.0 or less, thereby imparting stain resistance. Molded body. 3. A substrate is coated with perhydropolysilazane to form a ceramicized coating film having a Y value of 0.1 or more and 2.0 or less according to the evaluation method of claim 1, and then alkali is used. Alternatively, a molded product obtained by imparting hydrophilicity by hot water treatment. 4. The molded product is any one of a bathtub, a waterproof pan for bathroom, a bathroom counter, a bathroom wall, a washbasin, a washbasin, a kitchen counter, a component of a kitchen cabinet, a dish or a dishwasher. The molded article according to claim 2 or claim 3.