JPH05117590A - Inorganic coating material - Google Patents

Abstract

PURPOSE:To provide an inorganic coating material having excellent dispersibility and redispersibility and containing a solution produced by treating a hydrolyzable organosilane in a colloidal silica dispersion, a silanol-containing polyorganosiloxane, a catalyst, a specific inorganic pigment and fine silica particles. CONSTITUTION:The objective inorganic coating material is produced by compounding, as essential components, (A) a solution of a silica-dispersed oligomer of an organosilane obtained by hydrolyzing a hydrolyzable organosilane of formula I [R<1> is (substituted)1-8C univalent hydrocarbon group; X is hydrolyzable group; (n) is integer of 0-3] (e.g. methyl trimethoxysilane) in a colloidal silica dispersed in an organic solvent or in water, (B) a polyorganosiloxane containing silanol group in the molecule and expressed by formula II [R<2> is (substituted)1-8C univalent hydrocarbon group; 0.2<=a<=2; 0.0001<=b<=3; a+b<4], (C) a catalyst (e.g. butyltin dilaurate) and (D) a pigment (e.g. titanium oxide) having a #-potential of >=30eV in a solvent to be used in the preparation of the dispersion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic paint which ensures excellent pigment dispersibility and forms a film having good substrate hiding and / or coloring properties.

[0002]

2. Description of the Related Art Inorganic paints such as silicon alkoxide-polymer silanol-based coating materials have weather resistance and form coating films at 50 ° C. or below or at room temperature. When actually using this coating material for hiding or coloring the substrate,
The pigment must be dispersed and used.

[0003]

However, under the present circumstances, it is difficult to secure excellent pigment dispersibility and redispersibility over a long period of time. An object of the present invention is to provide an inorganic coating material having excellent dispersibility and redispersibility of an inorganic pigment by selecting an appropriate pigment.

[0004]

As a result of intensive studies on the means for solving the above-mentioned problems, the inventors have found that the medium in which the pigment is to be dispersed (for example, alcohol or a mixed solvent of alcohol and another organic solvent) Focusing on the ζ potential in the solvent), correlating it with the ζ potential in the resin, and selecting a pigment having a ζ potential in the solvent of plus 30 eV or more improves the familiarity between the pigment and the resin. It has been found that the above problems can be solved. Furthermore, it was also found that the dispersibility and redispersibility can be further improved by using fine particle silica of 50 mm or less in combination. The present invention has been completed based on these findings.

That is, the present invention provides the following components A, B,
Provided is an inorganic coating containing C and D as essential components. The present invention also provides an inorganic coating containing the following components A, B, C, D and E as essential components. (A) the general formula ^{_{R 1 n SiX 4-n ...}} (I) [wherein, R ¹ represents a monovalent hydrocarbon group substituted or unsubstituted C1-8 identical or different, n represents 0 An integer of 3 and X represents a hydrolyzable group. ] A silica-dispersed oligomer solution of organosilane, which is obtained by hydrolyzing a hydrolyzable organosilane represented by the following in colloidal silica dispersed in an organic solvent or water. (B) Average composition formula R ² _a Si (OH) _b O _{(4-ab) / 2} (II) [In the formula, R ² is the same or different and is a substituted or unsubstituted monovalent one having 1 to 8 carbon atoms. A hydrocarbon group, a and b
Are 0.2 ≦ a ≦ 2 and 0.0001 ≦ b ≦, respectively.
3 and a + b <4. ] The polyorganosiloxane containing the silanol group in a molecule represented by these. (C) Catalyst. (D) The ζ potential in the solvent to be dispersed is plus 3
An inorganic pigment having 0 eV or more. (E) Fine particle silica of 50 mm or less.

The silica-dispersed oligomer of the component A used in the present invention is the main component of the base polymer having a hydrolyzable group (X) as a functional group which is involved in the curing reaction when forming a film (coating). The colloidal silica is prepared by adding one or more kinds of the hydrolyzable group-containing organosilane represented by the general formula (I) (or the hydrolyzable organosilane) to colloidal silica dispersed in an organic solvent or water. It can be obtained by partially hydrolyzing the hydrolyzable organosilane with water contained therein or water added separately.

R ¹ in the hydrolyzable group-containing organosilane represented by the general formula (I) represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, such as a methyl group,
Alkyl groups such as ethyl, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group; aralkyl groups such as 2-phenylethyl group, 3-phenylpropyl group An aryl group such as a phenyl group and a tolyl group; an alkenyl group such as a vinyl group and an allyl group; a chloromethyl group, a γ-chloropropyl group, 3,
Halogen-substituted hydrocarbon groups such as 3,3-trifluoropropyl group; and γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, γ-mercaptopropyl group, etc. Substituted hydrocarbons can be exemplified. Among them, the number of carbon atoms is 1 to 1 because of easy synthesis or easy availability.
Preferred are alkyl groups of 4 and phenyl groups.

As the hydrolyzable group X, an alkoxy group,
Examples thereof include acetoxy group, oxime group, enoxy group, amino group, aminoxy group and amide group. An alkoxy group is preferable because it is easily available and a silica-dispersed oligomer solution is easily prepared. As such a hydrolyzable group-containing organosilane, n in the general formula (I) is 0 to 0.
Mono-, di-, tri-, and tetra-functional alkoxysilanes, which are an integer of 3, acetoxysilanes, oximesilanes, enoxysilanes, aminosilanes, aminoxysilanes, amidosilanes, and the like. ..
Alkoxysilanes are preferred because they are easily available and a silica-dispersed organosilane oligomer solution is easily prepared.

In particular, tetramethoxysilane, tetraethoxysilane and the like can be exemplified as the tetraalkoxysilane with n = 0, and methyltrimethoxysilane, methyltriethoxysilane and methyltriisosilane are examples of the organotrialkoxysilane with n = 1. Propoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane,
Examples include 3,3,3-trifluoropropyltrimethoxysilane and the like. Further, as the diorganodialkoxysilane of n = 2, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane,
Examples thereof include diphenyldiethoxysilane and methylphenyldimethoxysilane, and examples of the triorganoalkoxysilane having n = 3 include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane and dimethylisobutylmethoxysilane. Furthermore, an organosilane compound generally called a silane coupling agent is also included in the alkoxysilanes.

Of these hydrolyzable group-containing organosilanes represented by the general formula (I), 50 mol% or more is n = 1.
A trifunctional compound represented by They are more preferably 60 mol% or more, and most preferably 70 mol% or more. If this content is less than 50 mol%, sufficient coating film hardness cannot be obtained, and the dry curability tends to be poor.

The colloidal silica in the component A is essential for increasing the hardness of the cured coating of the inorganic coating material of the present invention. As such colloidal silica, water-dispersible or non-aqueous organic solvent-dispersed colloidal silica such as alcohol can be used. Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content.
It is contained, and the silica content can be determined from this value.
When water-dispersible colloidal silica is used, water present as a component other than the solid content can be used for the hydrolysis of the organosilicon compound as the component A. These are usually made of water glass, but such colloidal silica can be easily obtained as a commercial product. The organic solvent-dispersed colloidal silica can be easily prepared by substituting the organic solvent for water in the water-dispersible colloidal silica. Such an organic solvent-dispersed colloidal silica can be easily obtained as a commercial product like the water-dispersed colloidal silica. The types of organic solvent in which colloidal silica is dispersed are, for example, methanol, ethanol, isopropanol (isopropyl alcohol: IPA),
lower aliphatic alcohols such as n-butanol and isobutanol; ethylene glycol derivatives such as ethylene glycol, ethylene glycol monobutyl ether and acetic acid ethylene glycol monoethyl ether; diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether and diacetone alcohol And one or more selected from the group consisting of these can be used. Toluene in combination with these hydrophilic organic solvents,
Xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can also be used.

When colloidal silica is used as the above-mentioned component A, the compounding ratio is parts by weight including the dispersion medium. In the component A, colloidal silica is contained in the range of 5 to 95% by weight as a silica content, more preferably 10 to 90% by weight, and most preferably 20 to 85% by weight. If the content is less than 5% by weight, the desired coating hardness cannot be obtained, and if it exceeds 95% by weight, it is difficult to uniformly disperse silica, and the component A may cause gelation and other inconveniences.

The silica-dispersed oligomer of component A can be usually obtained by partially hydrolyzing a hydrolyzable group-containing organosilane in water-dispersed colloidal silica or organic solvent-dispersed colloidal silica. The amount of water used with respect to the hydrolyzable organosilane is preferably 0.001 to 0.5 mol of water with respect to 1 mol of the hydrolyzable group (X). If it is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and if it exceeds 0.5 mol, the stability of the partial hydrolyzate becomes poor. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organoalkoxysilane and colloidal silica may be mixed and a required amount of water may be added and blended. At this time, the partial hydrolysis reaction proceeds at room temperature. You may heat at 60-100 degreeC in order to accelerate a partial hydrolysis reaction. Further, for the purpose of promoting partial hydrolysis reaction, hydrochloric acid, acetic acid, silane halide, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluene. Organic and inorganic acids such as sulfonic acid and oxalic acid may be used as catalysts.

The component A has a pH of 2.0 to 7.0, preferably 2.5 to 7.0 in order to obtain stable performance over a long period of time.
It is better to set it to 6.5, and more preferably to 3.0 to 6.0.
When the pH is out of this range, particularly when the amount of water used is 0.3 mol or more with respect to X1 mol, the long-term performance deterioration of the component A is remarkable. When the pH of the component A is outside this range, it may be adjusted by adding a basic reagent such as ammonia or ethylenediamine if it is on the acidic side of this range. It may be adjusted using an acidic reagent such as. However, the adjusting method is not particularly limited.

The silanol group-containing polyorganosiloxane as the component B can be represented by the above average composition formula (II). Examples of R ^{2 in the} formula (II) include the same as R ¹ in the above formula (I), preferably an alkyl group having 1 to 4 carbon atoms, a phenyl group, a vinyl group, and γ-glycid. Substituted hydrocarbon groups such as xypropyl group, γ-methacryloxypropyl group, γ-aminopropyl group and 3,3,3-trifluoropropyl group, more preferably methyl group and phenyl group. Further, in the formula, a and b are numbers that satisfy the above relationship, and if a is less than 0.2 or b is more than 3, there is an inconvenience such as cracking in the cured film, and a is 2 When it exceeds 4 and b is less than 0.0001, curing does not proceed well.

Such silanol group-containing polyorganosiloxane is prepared by a known method using one or a mixture of two or more of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or the corresponding alkoxysilanes. Can be obtained by hydrolysis with a large amount of water. When a silanol group-containing polyorganosiloxane is hydrolyzed by a known method using an alkoxysilane, a small amount of unhydrolyzed alkoxy groups may remain. That is, a polyorganosiloxane in which a silanol group and an extremely small amount of an alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used.

The curing catalyst, which is the C component used in the present invention, accelerates the condensation reaction between the A component and the B component as described above to cure the coating film. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amines such as dibutylamine-2-hexoate, dimethylamine acetate and ethanolamine acetate. Salts; carboxylic acid quaternary ammonium salts such as tetramethylammonium acetate; amines such as tetraethylpentamine; N-β-aminoethyl-
Amine-based silane coupling agents such as γ-aminopropyltrimethoxysilane and N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum alkoxides and aluminum chelates. Alkaline catalysts such as aluminum hydroxide, potassium hydroxide and the like; titanium compounds such as tetraisopropyl titanate, tetrabutyl titanate and titanium tetraacetylacetonate,
There are halogenated silanes such as methyltrichlorocine, dimethyldichlorosilane, and trimethylmonochlorosilane, but there is no particular limitation as long as they are effective for the condensation reaction with the components A and B in addition to the above catalyst.

The mixing ratio of the A component and the B component is 99 to 1 parts by weight of the B component to 1 to 99 parts by weight of the A component,
More preferably, component B is 5 to 95 parts by weight with respect to component B 9
5 to 5 parts by weight, most preferably 10 to 90 parts by weight of component A and 90 to 10 parts by weight of component B. However, the total of the components A and B is 100 parts by weight. If the amount of the component A is less than 1 part by weight, the room temperature curability is poor and sufficient coating hardness cannot be obtained. On the other hand, if the amount of the component A exceeds 99 parts by weight, the curability may be unstable and a good coating film may not be obtained.

The addition amount of the component C is preferably 0.0001 to 10 parts by weight, more preferably 0.0005, based on 100 parts by weight of the total of the components A and B.
To 8 parts by weight, and most preferably 0.0007 to 5 parts by weight. If the amount of component C added is less than 0.0001 parts by weight, it will not cure at room temperature, and if it exceeds 10 parts by weight, heat resistance and weather resistance will be poor.

The hydrolyzable group contained in the silica-dispersed oligomer of the component A and the silanol group of the component B are subjected to a condensation reaction by heating at room temperature or low temperature in the presence of the curing catalyst of the component C to form a cured film. To do. Therefore, like the moisture-curing type coating composition, the inorganic coating material of the present invention is hardly affected by humidity even when cured at room temperature. Further, the heat treatment can accelerate the condensation reaction to form a cured film.

The molecular weight of the component B polyorganosiloxane used in the present invention is preferably 700 to 20,000. The molecular weight mentioned here is a weight average molecular weight in terms of standard polystyrene measured by GPC (gel permeation chromatography). When the molecular weight of the polyorganosiloxane is less than 700, the curability of the resulting coating film is slow and cracks are likely to occur.
When the molecular weight exceeds 20,000, the coating film made of the pigment-added paint has no gloss and the smoothness is poor.

The component D pigment may be a pigment such as titanium oxide or a composite oxide (for example, a metal composite oxide) as it is, or may be subjected to an inorganic and / or organic surface treatment before being dispersed. Medium (or
A medium used to store dispersedly. For example, the ζ potential in alcohol or a solvent such as a mixed solvent of alcohol and another organic solvent) is set to be +30 eV or more. The treatment composition is not particularly limited, but Al ₂ O ₃ , Z
It is desirable to use rO ₂ , SiO ₂ or the like alone or in combination of two or more kinds. When the absolute value of the ζ potential of the pigment is small, the electrical repulsion between the pigments is small and the dispersibility is deteriorated, and the pigment is apt to settle.
In addition, even if the absolute value is 30 eV or more, the negative sign is dispersed in the inorganic paint, which has poor redispersibility after long-term storage and becomes hard to agglomerate and cannot be used. Becomes worse. This can be judged by the fact that the pigment sedimentation value after long-term storage is larger than the initial pigment sedimentation value.

The ζ potential is generally obtained from the following equation (a) by using the electrophoresis method. ζ = 4πηlu / Dε (a) [ζ: zeta potential [eV], π: circular constant, η: viscosity {viscosity of medium in which pigment is dispersed (excluding pigment)} [cp
s], l: distance between electrodes [cm], u: moving speed (moving speed of interface of dispersed portion of pigment) [cm / sec], D: applied voltage [V], ε: dielectric constant {pigment dispersed Dielectric constant of medium (excluding pigment)}] This method is a relatively simple and accurate method because it can prevent an error due to overlapping of electric double layers as compared with the measurement of streaming potential.

The particle size of the pigment is not particularly limited, but is preferably 0.01 to 2 microns. These pigments may be used alone or in combination of two or more. The amount of the pigment added is not particularly limited because the hiding property varies depending on the type of the pigment, but in the case of an inorganic pigment, for example, 15 to 80 parts by weight is based on 100 parts by weight of the solid content of the mixture of the A component and the B component. preferable. If it is less than 15 parts by weight, the hiding property may not be obtained, and if it exceeds 80 parts by weight, the smoothness of the coating film may be deteriorated.

The fine particle silica of the component E has an average primary particle diameter of 50 mm or less, preferably 1 to 50 mm, and may be one whose surface is treated with an inorganic or organic substance. This fine particle silica is obtained by a dry manufacturing method such as a gas phase method, whereas the colloidal silica as the component A is obtained by a wet manufacturing method. The addition amount of the E component is, for example, 0.1 to 100 parts by weight of the solid content of the mixture of the A component and the B component.
10 parts by weight is desirable. In the inorganic coating material of the present invention, the fine particle silica becomes negatively charged and is adsorbed around the positively charged pigment to improve dispersibility and redispersibility.

The pigment may be dispersed by a usual method. Also,
At that time, it is possible to use a dispersant, a dispersion aid, a thickener, a coupling agent and the like. Furthermore, leveling agents, dyes, metal powders, glass powders, antioxidants, within a range that does not affect dispersion,
An ultraviolet absorber or the like can be added. The inorganic coating material of the present invention can be diluted with various organic solvents for easy handling. The type of the organic solvent can be selected according to the type or the molecular weight of the monovalent hydrocarbon group of the component A or the component B. Examples of such an organic solvent include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol, which are shown as a dispersion solvent for colloidal silica; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl acetate. Examples thereof include ethylene glycol derivatives such as ethers; diethylene glycol, derivatives of diethylene glycol such as diethylene glycol monobutyl ether, and diacetone alcohol. One or more kinds selected from the group consisting of these can be used. .. In combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be exemplified.

The method for storing the inorganic pigment of the present invention is as follows:
Assuming that the A component in which the D component is dispersed is the A ′ component, A ′,
In general, each of the components B and C is separately stored in a three-pack form, but the mixed component of the A ′ component and the C component and the B component are separated into two packages and both are used at the time of use. It is also possible to mix them or to form a single package in which all ingredients are mixed and stored in one container. However, when mixing and storing the A'component and the C component, the pH of the A'component is adjusted to 2
It is preferable to add the component C after adjusting to 7 to 7, and it is more preferable that the amount of water used is 0.3 mol or less relative to 1 mol of the hydrolyzable group (X) of the organoalkoxysilane of the component A ′. ..

The inorganic coating material of the present invention includes plastics such as polycarbonate resin, acrylic resin and ABS resin;
Metals such as aluminum, stainless steel, copper, iron, and duralumin; or wall materials made of paper, wood, glass, cement, plaster, etc., and acrylic, alkyd, polyester, epoxy, urethane-based paints It is also applicable to surface protection such as, and there is no particular limitation on the material and type of the article to be coated.

The thickness of the coating film is not particularly limited and may be, for example, 0.1 to 100 μm, but in order that the coating film can be stably adhered and held for a long period of time without cracks or peeling, It is preferably 1 to 80 μm. The inorganic coating material of the present invention can be coated by a usual coating method, for example, brush coating, spray coating, dip coating, flow coating, roll coating, curtain coating,
Various coating methods such as knife coating can be selected. The dilution ratio with the organic solvent is not particularly limited, and the dilution ratio may be determined as needed.

The inorganic coating material of the present invention is cured at room temperature or heat-cured at an appropriate temperature to form a coating film. Further, in the inorganic coating material of the present invention, if necessary, a leveling agent, a thickener, a dye, an aluminum paste, a glass frit, a metal powder, an antioxidant, an ultraviolet absorber, etc. may be influenced to achieve the object of the present invention. It can be added within the range not given.

[0031]

The ζ potential in the medium to be dispersed is plus 30
By using a pigment having an eV or higher, the dispersibility and redispersibility of the pigment are excellent.

[0032]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples.
In the following, all "parts" are "parts by weight" unless otherwise specified.
"%" Means "% by weight". First, a preparation example of the component A will be shown.

-Preparation example of component A 1-isopropanol-dispersed colloidal silica sol IPA-ST (particle diameter 10 to 20 mμ, solid content 30%, Nissan Chemical Industries, Ltd.) in a flask equipped with a stirrer, heating jacket, condenser and thermometer. 100 parts), 65 parts of methyltrimethoxysilane, and 5.05 parts of water were added, and a partial hydrolysis reaction was carried out at a temperature of 65 ° C. for about 5 hours while stirring and cooled to obtain a component A. This one is 48 at room temperature
The solid content when left to stand for 36 hours was 36%. The component A obtained here is referred to as A-1. Preparation conditions for A-1: Number of moles of water relative to 1 mol of hydrolyzable group: 0.1-Silica content of component A: 47.2% -Mole% of hydrolyzable group-containing organosilane with n = 1 ... 100 mol% -Preparation example of component A 2-Methanol-dispersed colloidal silica sol (particle size 10 to 20 mμ, solid content 30%, manufactured by Nissan Chemical Industries, Ltd.) in a flask equipped with a stirrer, heating jacket, condenser and thermometer. 150 parts, methyltrimethoxysilane 13
6 parts, dimethyldimethoxysilane 36 parts, water 19.4
And 75 parts of IPA were added and stirred to carry out a partial hydrolysis reaction at a temperature of 80 ° C. for about 3 hours and then cooled to obtain a component A. This product had a solid content of 32% when left to stand at room temperature for 48 hours. The component A obtained here is referred to as A-2. Preparation condition of A-2 Molar number of water to 1 mol of hydrolyzable group: 0.3-Silica content of component A: 33.5% -Mole% of hydrolyzable group-containing organosilane of n = 1 76.9 mol% Next, a preparation example of the component B will be shown.

-Preparation example of component B 1-Measure a mixture of 220 parts (1 mol) of methyltriisopropoxysilane and 160 parts of toluene in a flask equipped with a stirrer, heating jacket, condenser, dropping funnel and thermometer. Then, 105 parts of a 1% hydrochloric acid aqueous solution was added dropwise to the above mixed solution in 30 minutes to hydrolyze methyltriisopropoxysilane. After 40 minutes from the dropping, stirring was stopped, the lower layer mixed solution containing a small amount of hydrochloric acid separated into two layers and isopropyl alcohol were separated, and the remaining hydrochloric acid of the resin solution of toluene was removed by washing with water. After the toluene was removed under reduced pressure, it was diluted with isopropyl alcohol to obtain a 40% isopropyl alcohol solution of silanol group-containing organopolysiloxane having an average molecular weight of about 2000. B-
It is called 1. The molecular weight is measured by GPC using a measurement model name HLC-802UR (manufactured by Tosoh Corporation) and a calibration curve made with standard polystyrene. The subsequent molecular weight was also measured by the same method.

Preparation Example of Component B 2-1000 parts of water and 50 parts of acetone were weighed into a flask equipped with a stirrer, a heating jacket, a condenser, a dropping funnel and a thermometer, and methyltrichlorosilane 44 was added to the mixed solution. 2.8 parts (0.3 mol), dimethyldichlorosilane 38.7 parts (0.3 mol), phenyltrichlorosilane 84.6 parts (0.4 mol) and toluene 200
What was melt | dissolved in the part was hydrolyzed, dropping under stirring. After 40 minutes from the dropping, stirring was stopped, the reaction solution was transferred to a separatory funnel and allowed to stand still, the lower layer hydrochloric acid water separated into two layers was separated and removed, and then the toluene solution of the organopolysiloxane in the upper layer was depressurized. Water and hydrochloric acid remaining by stripping were removed by distillation together with excess toluene to obtain a 60% toluene solution of a silanol group-containing organopolysiloxane having an average molecular weight of about 3000. This is referred to as B-2.

The D component is as follows. D-1: TiO ₂ (Made in Thailand oxide, Inc. "TC-6
0 ", ζ potential in IPA = plus 42.3 eV) D-2: CuCr ₂ O ₄ (" Daipiro Color # 9512 "manufactured by Dainichiseika Co., Ltd., ζ potential in IPA = plus 39.6 eV) D -3: TiO ₂ ("Taipek C" manufactured by Ishihara Sangyo Co., Ltd.
R-90 ", ζ potential in IPA = plus 20.9 eV) D-4: CuCr ₂ O ₄ (" Daipiro Color # 9510 "manufactured by Dainichiseika Kogyo Co., Ltd., ζ potential in IPA = minus 31.4 eV). ) Even if the average particle size of TiO ₂ of the same kind is changed in the range of 0.1 to 0.4 μm, the average particle size of CuCr ₂ O ₄ of the same kind is changed in the range of 0.2 to 0.8 μm. However, the results were similar. That is, for the D component, the value of the ζ potential has a greater effect on the result than the average particle size.

The ζ potential was measured by the straight tube electrophoresis method using IPA as a pigment dispersant, and the pigment migration distance was measured for 20 minutes while applying a voltage of 100 V. It was As the E component, fine particle silica (SiO ₂ ) called Aerosil (manufactured by Nippon Aerosil Co., Ltd., # 200, average particle diameter 12 mm) was used.

-Example 1-38 parts of D-1 was added to 100 parts of A-1 and sanded.
It was processed in a mill at 1000 rpm for 20 minutes. Obtained
Liquid, N-β-based on 100 parts of liquid A as a curing catalyst.
Aminoethyl-γ-aminopropylmethyldimethoxy
Add 0.5 parts orchid and 1 part dibutyltin dilaurate,
A'solution was prepared. Pigment precipitation 24 hours after the preparation of A'solution
Deterioration and pigment sedimentation (redispersibility) after 1 month were measured.
And A'solution so that A solution and B solution are 50 parts: 50 parts.
Test in which B-1 liquid was mixed and aluminum was sprayed
For peace (product name Ulster, manufactured by Nippon Test Panel Co., Ltd.)
It is applied by spray coating so that the coating thickness is about 10 μm.
Cloth is applied and cured at a curing temperature of 100 ° C for 30 minutes to make it solvent resistant
A sex test was conducted.Pigment sedimentation 5% at 2000 rpm in Homo Disper manufactured by Tokushu Kika Co.
After stirring the A'solution for a minute, transfer it to a settling tube with a diameter of 35 mm.
Then, the pigment sedimentation distance from the surface layer after 6 hours was measured.
Samples that do not become uniform after stirring with a disper
Was not considered. Solvent resistance Lightly press the coating with gauze soaked in toluene
Rubbing 100 times, observing the state of the coating film at that time
Solvent resistance is good for those that do not exist, and bad for those that have changed (x)
And Good solvent resistance is defined as good curability (○)
It was

The solvent resistance (curability) was good. -Example 2-36 parts of D-1 was added with respect to 100 parts of A-2, and it processed for 20 minutes at 1000 rpm using a sand mill. To the obtained liquid, N-β-based on 100 parts of A liquid as a curing catalyst.
0.5 parts of aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate were added,
A'solution was prepared. After preparation of the A'solution, the pigment sedimentation property after 24 hours and the pigment sedimentation property after 1 month were measured, and then the A'solution and the B-2 solution were adjusted so that the A solution and the B solution were 50 parts: 50 parts. Mix the solution and apply it to a test piece (product name Ulster, manufactured by Nippon Test Panel Co., Ltd.) sprayed with aluminum by spray coating so that the coating film thickness is about 10 μm and cure at a curing temperature of 100 ° C. for 30 minutes. Then, the solvent resistance test was conducted.

The solvent resistance (curability) was good. -Example 3-48 parts of D-1 was added to 100 parts of A-1, and it processed at 1000 rpm for 20 minutes using a sand mill. To the obtained liquid, N-β-based on 100 parts of A liquid as a curing catalyst.
0.5 parts of aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate were added,
A'solution was prepared. After preparation of the A'solution, the pigment sedimentation property after 24 hours and the pigment sedimentation property after 1 month were measured, and then the A'solution and the B-2 solution were adjusted so that the A solution and the B solution were 50 parts: 50 parts. Mix the solution and apply it to a test piece (product name Ulster, manufactured by Nippon Test Panel Co., Ltd.) sprayed with aluminum by spray coating so that the coating film thickness is about 10 μm and cure at a curing temperature of 100 ° C. for 30 minutes. Then, the solvent resistance test was conducted.

The solvent resistance (curability) was good. -Example 4-36 parts of D-1 was added to 100 parts of A-1, and it processed at 1000 rpm for 20 minutes using a sand mill. To the obtained liquid, N-β-based on 100 parts of A liquid as a curing catalyst.
0.5 parts of aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate were added,
A'solution was prepared. After the preparation of A'solution, the pigment settling property after 24 hours and the pigment settling property after 1 month were measured, and then A part and B part were adjusted to 50 parts: 50 parts. Mix the solution and apply it to a test piece (product name Ulster, manufactured by Nippon Test Panel Co., Ltd.) sprayed with aluminum by spray coating so that the coating film thickness is about 10 μm and cure at a curing temperature of 100 ° C. for 30 minutes. Then, the solvent resistance test was conducted.

The solvent resistance (curability) was good. -Example 5-To 100 parts of A-1, 34 parts of D-1, 7.6 parts of D-2, and 1.9 parts of E were added, and 10 were added using a sand mill.
It was processed at 00 rpm for 20 minutes. In the obtained liquid, N-β-aminoethyl-γ was used as a curing catalyst for 100 parts of A liquid.
0.5 parts of aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate were added to prepare solution A '. After the preparation of the solution A ′, the pigment sedimentation property after 24 hours and the pigment sedimentation property after 1 month were measured.
Liquid A'and B-2 were mixed to make 50 parts, and spray-painted on an aluminum-fused test piece (product name Ulster, manufactured by Nippon Test Panel Co., Ltd.) so that the film thickness of the cured film was about 10 μm. Apply to a curing temperature of 100
A solvent resistance test was conducted by curing at 30 ° C. for 30 minutes.

The solvent resistance (curability) was good. -Comparative Example 1-48 parts of D-3 was added to 100 parts of A-1 and treated with a sand mill at 1000 rpm for 20 minutes. To the obtained liquid, N-β-based on 100 parts of A liquid as a curing catalyst.
0.5 parts of aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate were added,
A'solution was prepared. After preparation of the A'solution, the pigment sedimentation property after 24 hours and the pigment sedimentation property after 1 month were measured, and then the A'solution and the B-2 solution were adjusted so that the A solution and the B solution were 50 parts: 50 parts. Mix the solution and apply it to a test piece (product name Ulster, manufactured by Nippon Test Panel Co., Ltd.) sprayed with aluminum by spray coating so that the coating film thickness is about 10 μm and cure at a curing temperature of 100 ° C. for 30 minutes. Then, the solvent resistance test was conducted.

The solvent resistance (curability) was good. -Comparative Example 2-46 parts of D-4 was added to 100 parts of A-1, and the mixture was treated with a sand mill at 1000 rpm for 20 minutes. To the obtained liquid, N-β-based on 100 parts of A liquid as a curing catalyst.
0.5 parts of aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate were added,
A'solution was prepared. After the preparation of A'solution, 24 hours later, the pigment sedimentation property was measured, and after 1 month, it was 200 with a disper.
It was not uniform after 5 minutes at 0 rpm.

-Comparative Example 3-30.4 parts of D-3 to 100 parts of A-1 and D-4
7.6 parts were added and the mixture was mixed with a sand mill at 1000 rpm for 2
It was processed for 0 minutes. A liquid 1 was added to the obtained liquid as a curing catalyst.
A solution A was prepared by adding 0.5 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate to 00 parts. After the preparation of the liquid A ′, the pigment sedimentation property was measured 24 hours later, and after 1 month, the dispersion did not become uniform at 2000 rpm for 5 minutes.

Comparative Example 4-48 parts of D-3 and 1.9 of E with respect to 100 parts of A-1
Then, the mixture was added in parts and treated at 1000 rpm for 20 minutes using a sand mill. A'solution was prepared by adding 0.5 part of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate to 100 parts of A solution as a curing catalyst. .. After preparation of A'solution, 2
After measuring the pigment sedimentation property after 4 hours and the pigment sedimentation property after 1 month, A ′ was adjusted so that the liquids A and B were 50 parts: 50 parts.
Solution and B-2 solution are mixed and applied on a test piece (trade name: Ulster, manufactured by Nippon Test Panel Co., Ltd.) that is aluminum-melted by spray coating so that the coating film thickness is about 10 μm and the curing temperature is 100. A solvent resistance test was conducted by curing at 30 ° C. for 30 minutes.

The solvent resistance (curability) was good. -Comparative Example 5-48 parts of D-4 and 1.9 of E with respect to 100 parts of A-1.
Then, the mixture was added in parts and treated at 1000 rpm for 20 minutes using a sand mill. A'solution was prepared by adding 0.5 part of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane and 1 part of dibutyltin dilaurate to 100 parts of A solution as a curing catalyst. .. After preparation of A'solution, 2
After measuring the pigment sedimentation property after 4 hours and the pigment sedimentation property after 1 month, A ′ was adjusted so that the liquids A and B were 50 parts: 50 parts.
Solution and B-2 solution are mixed and applied on a test piece (trade name: Ulster, manufactured by Nippon Test Panel Co., Ltd.) that is aluminum-melted by spray coating so that the coating film thickness is about 10 μm and the curing temperature is 100. A solvent resistance test was conducted by curing at 30 ° C. for 30 minutes.

The solvent resistance (curability) was good. The compounding conditions of the inorganic coating materials of the above Examples and Comparative Examples and the evaluation results of the pigment settling property, solvent resistance and curability are summarized in Table 1.

[0049]

[Table 1]

As shown in Table 1, the inorganic coating materials of Examples had good dispersibility and redispersibility, while the inorganic coating materials of Comparative Example had poor dispersibility and redispersibility.

[0051]

The inorganic coating material of the present invention can maintain a stable dispersed state for a long period of time by selecting a pigment having a ζ potential of plus 30 eV or more. The inorganic coating material of the present invention can maintain a stable dispersed state for a long period of time by selecting a pigment having a ζ potential of 30 eV or more and by adding fine particle silica having a particle size of 50 mm or less.

Therefore, the industrial value of the inorganic coating material of the present invention is great.

Claims (2)

[Claims] 1. An inorganic coating comprising the following components A, B, C and D as essential components. (A) the general formula ^{_{R 1 n SiX 4-n ...}} (I) [wherein, R ¹ represents a monovalent hydrocarbon group substituted or unsubstituted C1-8 identical or different, n represents 0 An integer of 3 and X represents a hydrolyzable group. ] A silica-dispersed oligomer solution of organosilane, which is obtained by hydrolyzing a hydrolyzable organosilane represented by the following in colloidal silica dispersed in an organic solvent or water. (B) Average composition formula R ² _a Si (OH) _b O _{(4-ab) / 2} (II) [In the formula, R ² is the same or different and is a substituted or unsubstituted monovalent one having 1 to 8 carbon atoms. A hydrocarbon group, a and b
Are 0.2 ≦ a ≦ 2 and 0.0001 ≦ b ≦, respectively.
3 and a + b <4. ] The polyorganosiloxane containing the silanol group in a molecule represented by these. (C) Catalyst. (D) The ζ potential in the solvent to be dispersed is plus 3
An inorganic pigment having 0 eV or more. 2. The inorganic coating composition according to claim 1, wherein (E) fine particle silica having a particle size of 50 mm or less is also an essential component.