JPH0236275A - Coating film - Google Patents

Abstract

PURPOSE:To provide the subject coating film having excellent weather resistance, cracking resistance, hardness, etc., by coating a substrate with an inorganic coating agent wherein components reduced on heating are contained in the vehicle solid content of the coating film, the reduced components comprising specific components, and a component remained on the heating is SiO2 component. CONSTITUTION:The objective coating film is formed by coating a substrate with a coating containing a silicon compound of the formula (R<1> is methyl, etc.; R<2> is alkyl; n is 0-2), etc., as vehicle components wherein 10-25wt.% of components reduced on heating to 100-600 deg.C are contained in the vehicle solid contents of the coating, the reduced components comprising water and organic substances >=70wt.% of which comprise the components of the formula CnH2n+1 (n is 1-4), and >=80wt.% of components remained on the heating is SiO2 component.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a coating film applied to a substrate made of various materials for surface protection.

[Conventional technology]

Conventionally, it has been used for construction, etc., and has been made from inorganic hardened materials made from cement, gypsum, etc. and fillers such as silica sand and pulp, or various base materials such as wood and synthetic resins, with water resistance and chemical resistance. Coatings made of organic paints, etc., are applied in order to protect the surface of the surface, but the coating films made of organic coatings as mentioned above have poor weather resistance. In addition to this drawback, there was also the problem that it was easily damaged due to its low hardness.

Therefore, attempts have been made to use inorganic coating agents such as silicone instead of organic coating agents. A coating film made of an inorganic coating agent has excellent weather resistance and hardness, and thus can eliminate the above-mentioned drawbacks of a coating film made of an organic coating agent. Regarding the specific composition and manufacturing method of such an inorganic coating agent, please refer to JP-A-62-27
It is disclosed in Japanese Patent Publication No. 5170, Japanese Patent Publication No. 6112106, etc.

[Problem to be solved by the invention]

However, coating films using conventional inorganic coating agents have the drawback of being prone to cracking and peeling when applied to the above-mentioned inorganic cured materials that undergo relatively large dimensional changes during use. Ta.

Therefore, the object of this invention is to solve the problems of conventional coating films made of inorganic coating agents, and to provide a coating film that has excellent weather resistance and hardness, and is resistant to cracking and peeling. be.

[Means to solve the problem]

The inventors researched the properties of coating films made of various inorganic coating agents, and found that the weather resistance and other properties of coating films were determined by evaporation and vaporization when the coating film was heated to a certain temperature. We found that this is related to the components lost through combustion, etc. Furthermore, they discovered that by adjusting the component that loses weight during heating, it is possible to obtain a coating film that is excellent in weather resistance, hardness, crack resistance, and peeling resistance, and has completed this invention. be.

The coating film of the present invention that solves the above problems is:
A coating film formed by applying an inorganic coating agent to a base material, in which the vehicle solid content of the coating film contains 100% when heated.
10-25-E% of components that lose weight between ~600'c
Contains 70w of organic matter components in weight loss ingredients.
t% or more consists of -CnH=n+, (n=1 to 4),
80 wt% or more of the residual component after heating is made to be SiC2.

[For production]

The performance of a coating film is mainly determined by the composition of the vehicle (vehicle) among the compositions of the coating film. Therefore, by defining the composition of the vehicle solid content of the coating film, the performance of the coating film can be adjusted. Therefore, by specifying the weight ratio of the components that lose weight at a certain temperature during heating and the components that remain in the vehicle solid content of the coating film, weather resistance, hardness, crack resistance, and peeling resistance can be improved. Coating H within an appropriate range
You can get many things.

C Example] The coating film in this invention is mainly composed of SiO□ component, and also contains inorganic substances such as Met O (here, Me is alkali gold mud), phosphorus compounds, TiO□ component, ZrO, etc. Sometimes it is. Furthermore, various coloring agents are included as other ingredients.

Fillers, surfactants, thickeners, ultraviolet absorbers, small amounts of organic polymers, etc. can also be included depending on the use and purpose.

Regarding the composition and manufacturing method of the coating agent for forming the above-mentioned coating film, the inventors have previously applied for a patent in Japanese Patent Application No. 41702/1982,
Those disclosed in Japanese Patent Application No. 153891 and Japanese Patent Application No. 62-241956 can be used.

The coating agent can be defined by the composition of the ingredients as in the above-mentioned prior patent, but when the coating agent is applied and dried to form a coating film,
Since each compounded component changes due to condensation polymerization, even if the composition and component ratio of the coating agent are specified, it will differ from the composition and component ratio of the coating film, and the application method of the coating agent The performance of the coating erf and film may change depending on the coating erf and the like. Therefore, in this invention, as a result of analyzing the composition and performance of the coating film itself formed by coating a coating agent on a suitable base material, it was found that when the coating film is heated to an elevated temperature, evaporation occurs from the coating film. It has been discovered that the practical performance of the coating film itself is determined by the ratio of components that evaporate and those that remain after heating, and the difference in these components.

The inventors have investigated the amount of N lost during heating and temperature increases for various coating films as described above! As a result of measuring the components and residual components, it was found that those satisfying the following conditions had preferable performance as a coating film. In addition, in order to heat and raise the temperature of the coating film, the weight loss component is measured while heating and raising the temperature at a rate of generally 10° C./min using a differential thermal analyzer or the like.

A coating film with excellent weather resistance, hardness, crack resistance, and peeling resistance contains 10 to 25 wt% of components that lose weight between 100 and 600°C during heating in the vehicle solid content of the coating film. Contains 5. The above weight loss ingredients are 1
If it is less than 0 wt%, it has excellent weather resistance and hardness, but
The paint film is prone to cracking and peeling. Also, 25wt%
Exceeding this will result in a decrease in hardness and weather resistance. The component that loses weight during heating as described above is mainly due to moisture or organic matter in the coating film.

The components of the vehicle solid content that are reduced during heating are as follows:
It consists of water and organic matter, of which more than 79 wt% of the weight loss due to organic matter is -Cn Hzn++ (n=1 to 4
) has good weather resistance.

In addition, the organic substances that become the Mffl component as described above include those having groups, those having mercapto groups such as R3(CH,), -, and acrylic resin-based, urethane-based, polyvinyl alcohol-based, and cellulose-based components. It may also include.

Heating sauce? , more than 80wt% of the residual components after heating are SiO2
The film-forming properties and stability of the coating agent will be better if the composition is composed of these ingredients.

The basic composition of the coating film is the vehicle component described above, but in addition to the vehicle component,
It may contain pigments for coloring purposes and appropriate additives. These components are not more than 5Qwt% of the vehicle components,
Preferably, it is carried out at 55 wt % or less, and when it is 60-15 or more, the surface condition of the coating film deteriorates. Pigments and the like other than such vehicle components are not included in the vehicle solid content in this invention, and are not included in the calculation of the weight ratio of reduced components and residual components.

Note that the coating agent may contain colloidal silica, but in this case, the colloidal silica is incorporated into the vehicle component and is thus included in the solid content of the vehicle. As colloidal silica, ultrafine particles with a particle size of 100 μm or less with good dispersibility are preferable. When forming a coating film on the above-mentioned inorganic cured product, a modified silicone, urethane primer, acrylic primer, etc. is applied as a primer. If you do so, more favorable performance can be achieved.

The coating agent capable of forming the coating film according to the present invention is disclosed in the above-mentioned Japanese Patent Application No. 62-4170.
Among those disclosed in the prior art such as No. 2, those that can provide a coating film that meets the above conditions can be selected and used, and specific examples of coating agents will be described below.

For example, a coating agent mainly composed of silicon alkoxide, -formation; R'nS i (OR"
) 4-n (wherein R1 is a methyl group or ethyl group, R2 is an alkyl group, and n is 0 to 2) and/or its partial hydrolysis product is the main vehicle component. A coating agent is used, and colloidal silica may be added to the above composition (silicon alkoxides such as epoxy groups may also be included as a minor component).

The coating agent having the above composition is hydrolyzed and condensed in the presence of a catalyst, a curing agent, and the like. Here, the catalyst, curing agent, and curing accelerator added as necessary include, for example, inorganic acids such as hydrochloric acid, phosphoric acid, and sulfuric acid, and organic acids such as formic acid, acetic acid, and chloroacetic acid. An acidic catalyst consisting of a diluted solution, a quaternary ammonium salt or amine salt of each of the inorganic and organic acids, an organic metal compound such as an organic tin compound, etc. are used, and water etc. are used as a curing agent. These catalysts and curing agents may be used alone or in combination.

Various diluting solvents may be used to hydrolyze and condense the coating agent. Specific examples of solvents include methanol, ethanol, isopropyl alcohol (IPA)
Examples include lower alcohols such as ethylene glycol, ethylene glycol monomethyl ether, etc., and these solvents are used alone or as a mixed solvent.

Silicon alkoxide coating agents such as those mentioned above are
Appropriate amounts of catalyst and curing agent are added to silicon alkoxide monomer to form a prepolymer with an alkoxide group at the end, and at the time of use, further components such as catalyst and curing agent or silica gel are added as necessary. Then, final curing is performed to form a coating film. Therefore, the above-mentioned coating agent is usually stored in two packages containing a prepolymer and a catalyst, but it is not a single package in which all components are mixed in advance and stored in one container. Good too.

Methods for applying coating agents to inorganic cured materials include spray painting, roll painting, flow coater painting,
Conventional coating film forming means such as dip coating are employed. In addition,
The primers described above are applied in a similar manner. The applied coating agent is dried and baked to form a coating film, and the drying baking conditions are 50 to 200
It is preferable to carry out the reaction at ℃, and in the case of primers, the temperature is between room temperature and 1℃.
Preferably, it is carried out at 00°C.

In addition to the silicon alkoxide-based coating agents mentioned above, there are various vehicle components for forming ordinary coating films, such as titanium alkoxide-based, zirconia alkoxide-based, water glass-based, phosphate-based, and balate-based. A coating agent is used.

Next, a description will be given of specific examples in which the coating film according to the present invention was actually produced, as well as comparative examples of conventional coating films, as well as test results for evaluating the performance thereof.

The base materials for forming the coating film are an alumina substrate (substrate ■) for coating film hardness, and a cement-based base Fi (substrate ■) for weather resistance and crank resistance tests, which is actually used. ) was used. Cement-based substrates are made of blast furnace cement, silica sand, pulp, vinylon fiber, etc.
These raw materials were made into paper, press-molded, and then steam-cured for use. The bulk density of the manufactured cement-based substrate was 1.6 g/cm.The cement-based substrate was coated with a urethane-modified silicone primer (manufactured by Toshiba Silicone Co., Ltd.) as a primer to a film thickness of 10 μm. Apply it so that it looks like this.

- Comparative Example 1 - (Blend of raw materials) Tetraethoxysilane 100 parts by weight IPA organosilica sol 100 (OSCAL 14
32: Manufactured by Catalyst Kasei Co., Ltd., SiO□ 30%) Methyltrimethoxysilane 60 〃IN H
(1! 1 “H, O’
10” these raw materials at 25°
Solution A was prepared by stirring at 500 rpm for 30 minutes under C. A, The solution was stored in a tightly capped state at 25°C for one week.

When using, 50 parts by weight of water per 100 parts by weight of A1 liquid,
Add 50 parts by weight of isopropanol and heat at 25°C at 50% by weight.
Stir at 0 rpm for 10 minutes to remove coating agent (C-1).
I got it. This coating agent was applied to the substrates (1) and (2) to a film thickness of LOn, and dried at 150°C for 60 minutes to obtain a coating film.

- Comparative Example 2 (Blend of raw materials) Tetraethoxysilane 201 parts IF) A organosilica sol 20 〃Methyltrimethoxysilane 50 〃Dimethyldimethoxysilane
47 〃IN HCl
1 H2010 = Isopropanol 20 These raw materials were treated in the same manner as in Comparative Example 1 to prepare A2 liquid. Az/eL was stored in a tightly capped state at 25°C for one week,
When using, 75 parts by weight of water per 100 parts by weight of A2 liquid,
After adding 20 parts by weight of isopropanol and performing the same treatment as in Comparative Example 1 to obtain a coating agent (C-2), a coating film was obtained in the same manner as in Comparative Example 1.

Comparative Example 3 - (Blend of raw materials) Tetraethoxysilane 50 parts by weight IPA organosilica sol 150 Methyltrimethoxysilane 100 Dimethyldimethoxysilane
20 〃IN HCI
0.5H,09,O These raw materials were treated in the same manner as in Comparative Example 1 to obtain A,
The solution was prepared and stored. At the time of use, 100 parts by weight of water and 30 parts by weight of isopropanol were added to 100 parts by weight of A88 liquid, and the coating agent (C-3) was obtained by the same treatment as in Comparative Example 1. A coating film was obtained by this treatment.

Comparative Example 4- (Blend of raw materials) Tetraethoxysilane IPA Organosilica sol methyltrimethoxysilane Dimethyldimethoxysilane INI-(Cj2H,0 Isopropanol 40 parts by weight 100 〃 10 〃 1 〃 7 〃 100〃 These raw materials were Processed in the same manner as in Comparative Example 1, A4
The solution was prepared and stored. At the time of use, 55 parts by weight of water, 30 parts by weight of isopropanol, and 90 parts by weight of tetraisopropoxy titanium were added to 100 parts by weight of A44 liquid, and the coating agent (C-4 ) was then subjected to the same treatment as in Comparative Example 1 to obtain a coating film.

Example 1 - (Blend of raw materials) Tetraethoxysilane 20 parts by weight IPA silica sol 120 Methyltrimethoxysilane 100 Dimethyldimethoxysilane
10 〃Isoproper tool 30
〃IN HCI 1〃ToI20
6 These raw materials were treated in the same manner as in Comparative Example 1 to prepare and store B1 solution. At the time of use, 60 parts by weight of water and 40 parts by weight of isopropanol were added to 100 parts by weight of liquid B, and a coating agent (C-5) was obtained by the same treatment as in Comparative Example 1.
A coating film was obtained by the same treatment as above.

Example 2 (Composition of raw materials) Tetraethoxysilane 10 parts by weight [PA silica sol 100 〃Methyltrimethoxysilane 100〃Dimethyldimethoxysilane
25 Isoproper tool 80
〃IN HCI 1 〃H20
5. / These raw materials were treated in the same manner as in Comparative Example 1 to obtain B2.
The solution was prepared and stored. At the time of use, 43 parts by weight of water and 43 parts by weight of isopropanol were added to 100 parts by weight of B22 liquid, and a coating agent (C-6) was obtained by the same treatment as in Comparative Example 1. A coating film was obtained by this treatment.

Example 3 - 75 parts by weight of commercially available titanium oxide and 0.3 parts by weight of finely powdered silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.) were added to 100 parts by weight of the 82 liquid of Example 2, and these materials were mixed with Disper ( Add glass beads into the container and disperse at 2000 rpm for 15 minutes using a B2
'Liquid was obtained. After storing B2 solution at 25°C for one week in a tightly stopper, add 40 parts by weight of water to 100 parts by weight of 82' solution before use.
Weight part.

After adding 40 parts by weight of isopropanol and 1 part by weight of IN HC, a coating agent (C-7) was obtained by the same treatment as in Comparative Example 1, and then a coating film was obtained by the same treatment as in Comparative Example 1. .

As is clear from the above composition, the vehicle components of Example 3 are almost the same as those of Example 2.

Example 4 - (Composition of raw materials) Tetraethoxysilane 1071 parts IPA silica sol 100 〃Methyltrimethoxysilane 100 〃γGlycidoxyprobyltrimethoxysilane 10 〃Dimethyldimethoxysilane 1o 〃Isopropanol 80 JIS H (11〃H ,06 These raw materials were treated in the same manner as in Comparative Example 1 to obtain B4
The solution was prepared and stored. At the time of use, 40 parts by weight of water and 40 parts by weight of isopropanol were added to 100 parts by weight of B4 liquid, and a coating agent (C-8) was obtained by the same treatment as in Comparative Example 1. A coating film was obtained by this treatment.

Example 5 - (Composition of raw materials) Tetraethoxysilane IPA Silica sol methyltrimethoxysilamphenyltrimethoxysilane 10 parts by weight 110 〃 100 〃 3 〃 γGlycidoxypropyldimethoxysilane 5 〃 Isopropatol 30 JIS LI
Cl 1 〃11□0
6 These raw materials were used in Comparative Example 1.
Solution B was prepared and stored in the same manner as above. During use, 55 parts by weight of water and 45 parts by weight of isopropanol were added to 100 parts by weight of liquid B, and further 30 parts by weight of zirconia isopropoxide Zr (OC=Hl)4 was added little by little to form a coating agent. After obtaining (C9), a coating film was obtained by the same treatment as in Comparative Example 1.

The coating films of each of the comparative examples and examples described above were analyzed and measured for weight loss components in the solid content of the vehicle while heating and increasing the temperature. The results are shown in Table 1 below. Weight loss was measured using DTA-TG (manufactured by Rigaku Denki Co., Ltd.).
Measurement was performed at a temperature increase rate of 0° C./min. The amount of -CnHz in the heating loss component is determined by IR analysis of the vehicle solid content of the coating film, and
It was confirmed that the component was lost during heating at 100-600°C. The amount of S i O in the residual components after heating was analyzed using a fluorescent X-ray analyzer (manufactured by Rigaku Denki Co., Ltd.).

In the table, the total amount wt% of the weight loss component represents the weight percentage of the weight loss component due to heating with respect to the vehicle solid content of the coating film, and -Cn Hzn++wt in the weight loss component.
% represents the weight ratio of the weight loss component to the total amount,
Sin in the residual component and component wt% represent the weight percentage of the entire vehicle solid content remaining after heating. Examples 2 and 3 have the same vehicle components, so the weight proportions of the weight loss component and the residual component are also the same.

Next, we tested the usage performance of each of the above coating films,
The results are shown in Table 1. During the performance test, the hardness of the coating film was measured according to JIS-5400. Adhesion and crack resistance are determined by 8 hours of hot water at 60°C and 16 hours of air drying.
After repeating 10 cycles, the coating film was visually evaluated. Weather resistance was determined by observing the state after 1000 hours of due cycle test.

From the above results, it was demonstrated that the examples of the present invention were superior in weather resistance, hardness, and crack resistance compared to comparative examples based on the prior art. In addition, Comparative Example 1 has poor crack resistance and weather resistance because the total amount of weight loss components is too small, whereas Comparative Example 2 has too much of the weight loss components, resulting in low hardness and poor weather resistance. Comparative Example 3 shows -Cn Hzn in the weight loss component
Weather resistance is poor due to too little l+ (hardness is also low. Comparative Example 4 has too little SiO in the residual components,
Poor crack resistance and weather resistance.

(Effects of the Invention) The coating film according to the present invention as explained above has the following properties: A coating film having weather resistance, hardness, crack resistance, and peeling resistance all within appropriate ranges can be obtained. Therefore, it can be used as a protective coating film for substrates with relatively large dimensional changes, such as inorganic cured materials, because it not only has excellent weather resistance and high hardness, but also has excellent durability without cracking or peeling over a long period of time. A coating film can be provided.

Claims (1)

[Claims] 1 A coating film formed by applying an inorganic coating agent to a base material, in which 1
Components that lose weight between 00 and 600℃ are 10 to 25 wt%
In addition, 70 wt% or more of the organic components in the weight loss component is -CnH_2_n_+_1 (n=1 to
4), and more than 80 wt% of the residual component after heating is S.
A coating film characterized by being an iO_2 component.