JP3297526B2 - Method for producing inorganic / organic fusion coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather-resistant and heat-resistant steel sheet provided with a coating having excellent workability and high hardness, and a method for producing the coating .

[0002]

2. Description of the Related Art Steel sheets are generally used after being painted. The purpose of the coating is to protect the base steel plate and at the same time to increase the durability and to beautify it. Painted steel sheets are used in large structures such as buildings, ships, bridges, etc., as well as various machines, automobiles, furniture, small electrical appliances, and daily necessities. The coating of these steel sheets is generally performed after processing and assembly (post-coating). However, in recent years, particularly in the field of home electric appliances and the like, a method of processing and assembling a steel plate (pre-coated steel plate) that has already been coated is being shifted. Pre-coated steel sheets are required to have workability in addition to the conventional functions such as corrosion protection. Therefore, in order to satisfy the above function, an organic polymer such as a polyester resin is used as a coating material. On the other hand, as a coating excellent in heat resistance, corrosion resistance and the like, there is an enamel in which a steel plate is coated with glass. The enamel is manufactured by processing a steel plate into a desired shape and then coating the glass with the glass (post-coating).

[0003] Since the coating step can be omitted from the processing / assembly line of the pre-coated steel sheet, pre-coating is also required in fields which currently rely on post-coating (for example, high hardness, high weather resistance, high heat resistance, etc.). It has become. However, since the conventional precoated steel sheet is basically coated with an organic polymer, there are limitations on surface hardness, weather resistance, heat resistance, and the like. On the other hand, a method of coating glass or ceramics to improve the surface hardness and heat resistance of the steel sheet can be considered, but the workability is impaired and the steel sheet cannot be used as a precoated steel sheet. For example, enamel cannot be processed. If a process such as bending is performed, the coated glass is easily peeled off. BACKGROUND ART In recent years, a steel sheet coated with an inorganic-organic fusion product in which a part of an inorganic polymer skeleton is substituted with an organic group has been considered as a flexible, high-hardness, heat-resistant coated steel sheet. According to the coated steel sheet, hardness and heat resistance are higher than organic coated steel sheet, and workability is higher than inorganic coated steel sheet such as enamel.

[0004]

As a method for producing a steel sheet coated with an inorganic-organic fusion, a solution prepared by hydrolyzing an alkoxide or a hydrolyzed alkoxide as an inorganic component and a dialkyldialkoxysilane as an organic component is used. Coating and heat treatment. In order to hydrolyze these alkoxides and dialkylalkoxysilanes, both solvents for the hydrolysis with water, for example, alcohols are required. However, the solution has a low viscosity because the solvent is used even when the alkoxide is polymerized. Further, when the hydrolyzed solution is concentrated and used to increase the viscosity of the solution, it immediately gels or the viscosity changes significantly during standing. Although the viscosity is an important control factor such as the film thickness in the coating process, it is difficult to control the viscosity of the alkoxide solution. The present invention has been made to solve the above problems,
It can increase the viscosity of the solution, and an object thereof is to provide a method of producing an inorganic-organic fusions the film and its ease of coating process with less aging change in viscosity.

[0005]

In order to achieve the above object, a soluble organic polymer is added to a solution obtained by mixing and hydrolyzing an alkoxide and a dialkyldialkoxysilane.
Process for manufacturing a coating solution Te, to form a coating film in the coating solution
Producing an organic-inorganic fusion target film by heat-treating that step and the coating film at 100 to 600 ° C..

An inorganic / organic fusion material is a material which is fused at the atomic and molecular level by polymerizing a metal or metalloid by chemical bonding to an organic substance composed of carbon, hydrogen, oxygen, nitrogen and the like. In the production process of the coating solution, the mixing order of the solutions, the order and number of hydrolysis, and the like can be variously changed.
For example, after adding a soluble organic polymer to a mixed solution of an alkoxide and a dialkyldialkoxysilane, and then hydrolyzing to produce a coating solution, adding a soluble organic polymer to a solution obtained by hydrolyzing the alkoxide and the dialkylalkoxysilane To prepare a coating solution, or to add a soluble polymer to a solution obtained by hydrolyzing an alkoxide and a dialkyldialkoxysilane, and further hydrolyze to prepare a coating solution.

The ratio of the dialkylalkoxysilane (A) as the organic component and the alkoxide (B) as the inorganic component is preferably in the range of 8.0 to 0.1 in terms of the molar ratio of A / B. If it is less than 0.1, the workability is impaired, so that the film is peeled off or cracked during processing. on the other hand,
If it exceeds 8.0, there is no problem in workability, but the surface hardness and heat resistance are significantly reduced. The ratio of the organic polymer is 0.1 to
A range of 10 wt% is preferred. If less than 0.1 wt%,
The viscosity of the hydrolyzed alkoxide solution cannot be made sufficiently high. If it exceeds 10 wt%, the viscosity of the hydrolyzed alkoxide solution becomes too high, or a large amount of cellulose remains in the coating film, and the hardness and heat resistance of the coating film decrease.

In the present invention, the organic polymer includes cellulose, polyethylene glycol, polyvinyl butyral,
One or more of polyvinyl alcohols. Alkoxide used in the present invention is not particularly limited, for example, methoxide, ethoxide, propoxide,
Butoxide and the like. The alkoxide has a part of the alkoxy group, β-diketone, β-ketoester,
Includes alkanolamines, alkylalkanolamines, derivatives substituted with organic acids, and hydrolyzed alkoxides. The metal and metalloid constituting the inorganic component in the present invention are limited to those capable of forming an alkoxide. For example, Si, Al, Ti, Zr, Ta, Nb,
Y, Co, etc.

In the hydrolysis of the alkoxide in the present invention, the hydrolysis is performed by adding water up to 10 times the mole of the alkoxide. At this time, an inorganic acid, an organic acid or both of them may be used as a catalyst. The water to be added may be diluted with an organic solvent such as alcohol.
If water is used in an amount of 10 mol times or more, gelation occurs immediately, which is not preferable.

The dialkyldialkoxysilane used in the present invention includes, for example, dimethyldimethoxysilane,
Dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dipropyldipropoxysilane , Dipropyldibutoxysilane,
Examples include diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldipropoxysilane, diphenyldibutoxysilane, and the like.

In the hydrolysis of the present invention, 0.5 to 10.0 times water is added to the unhydrolyzed alkoxy group. At this time, an inorganic acid, an organic acid or both of them may be used as a catalyst. The water to be added may be diluted with an organic solvent such as alcohol. If the amount of water is less than 0.5 mole times, the degree of polymerization is low, and it cannot be applied because it volatilizes during heat treatment. On the other hand, if it exceeds 10.0 mol times, it gels immediately and cannot be applied. In the hydrolysis, the dialkyl dialkoxysilane and the alkoxide are uniformly dispersed,
A soluble organic solvent is used. For example, various alcohols such as methanol, ethanol, propanol and butanol, acetone, toluene, xylene and the like. After the hydrolysis, the solvent, the alcohol generated by the hydrolysis, and the like may be distilled off under normal pressure or under reduced pressure for application.

The steel sheet used in the present invention is not particularly limited, and examples thereof include stainless steel sheets, steel sheets for various platings such as aluminum and zinc, and steel sheets plated with these. The coating on the steel sheet is performed by a spray coating method, a dip coating method, a spray coating method, a roll coating method, a spin coating method, or the like. Heat treatment after coating is 100-6
Perform at 00 ° C. When the temperature is lower than 100 ° C., the solvent or the like does not sufficiently evaporate, and hardness and heat resistance cannot be obtained. When the temperature exceeds 600 ° C., the solvent or the like evaporates rapidly, and pinholes and cracks occur in the coating.

[0013]

According to the method for producing an inorganic / organic fusion coated steel sheet of the present invention, the organic polymer is dissolved in the solution of the hydrolyzed alkoxide and the dialkyldialkoxysilane. The viscosity of the solution can be increased. The concentration can be increased by concentrating the solution of the hydrolyzed alkoxide and dialkyldialkoxysilane.However, the concentration of the condensed alkoxide is increased, and the intermolecular distance is shortened. Significant or gels quickly. According to the present invention, since the viscosity is controlled by the organic polymer, the intermolecular distance of the condensed alkoxide in the solution does not become short, the viscosity is stable, and gelation hardly occurs.

[0014]

EXAMPLES The method for producing a steel sheet coated with an inorganic / organic fused body according to the present invention will be specifically described with reference to the following examples. However,
The present invention is not limited to only these examples. Under the conditions shown in Table 1, a hydrolyzed alkoxide solution containing a soluble organic polymer was applied to a SUS403 steel plate with a bar coater, and then heat-treated to produce an inorganic-organic fusion-coated steel plate. The viscosity, coatability and heat resistance, surface hardness and workability of the prepared inorganic / organic fusion coated steel sheet were evaluated. The viscosity of the solution was measured using a B-type rotational viscometer. The heat resistance was determined by heating at 200 ° C. to 600 ° C. for 48 hours and then examining a temperature at which rust does not occur in a salt spray test. The surface hardness was measured by a pencil hardness test method. The processing method is
JIS G 3312 Evaluated at the limit of cracks in the coating film after 180 ° bending.

[0015]

[Table 1]

Table 2 shows the results. In the examples, the coatability is good and the heat resistance of the coated steel sheet produced is 450 to 600.
° C, surface height (3-6H) and workability (0-1)
T) was also good. On the other hand, as a comparative example, when the organic polymer was not added (No. 15) or when the addition amount was small (No. 16), the viscosity of the solution was too low, and the coating film thickness became thin. There were some areas where coating was possible and some areas where coating was not possible. When the amount of the organic polymer added was too large (Nos. 17 and 18), it was difficult to apply the solution because the solution viscosity became extremely high. Further, the coated steel sheet had low heat resistance and low surface hardness because a large amount of the added organic polymer remained in the coating film.

[0017]

[Table 2]

[0018]

Since the present invention is configured as described above, it has the following effects. According to the method for producing an inorganic / organic fusion coated steel sheet of the present invention,
Since the viscosity of the coating solution can be increased and the viscosity can be easily controlled, it is possible to provide a high-quality inorganic-organic fusion coated steel sheet having a uniform coating. Furthermore, since the solution is highly stable and can be stored as compared with a conventional coating solution for coating an inorganic / organic fusion material, it is easy to make a production plan. Therefore, it is possible to efficiently produce an inorganic / organic fusion coated steel sheet having high workability, high heat resistance and high heat resistance.

────────────────────────────────────────────────── (5) References JP-A-2-36282 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 7/14 B05D 7/24 302 C09D 163 / 00

Claims (7)

(57) [Claims] To 1. A alkoxide and a dialkyl dialkoxy solution silane were mixed to hydrolyze the step of producing a coating solution by adding a soluble organic polymer, coated with the coating solution
Process and the coating film to 100 to 600 a method of manufacturing an organic-inorganic fusion target film <br/> characterized in that it has a step of heat treatment at ℃ to form a film. 2. The ratio between the dialkyl dialkoxysilane (A) and the alkoxide (B) is 8.0 in a molar ratio of A / B.
In the range of ~ 0.1, the ratio of the organic polymer is 0.1 ~ of the solution.
Method of producing an inorganic-organic fusion target membrane of claim 1, wherein it is a 10 wt%. Wherein the organic polymer, cellulose, polyethylene glycol, polyvinyl butyral, the production of inorganic-organic fusion target membrane of claim 1 or 2, wherein the at one or more poly (vinyl alcohol) Method. 4. The step of forming a coating film with the coating solution,
A process for forming a coating film on a steel plate.
4. The method for producing an inorganic / organic fusion coating film according to claim 1. 5. An alkoxide and a dialkyl dialkoxy
Contains hydrolyzate of silane and organic polymer soluble in the solution
Coating solution characterized in that 6. A dialkyl dialkoxysilane (A)
The ratio of the alkoxide (B) is 8.0 in a molar ratio of A / B.
In the range of ~ 0.1, the ratio of the organic polymer is 0.1 ~ of the solution.
The coating according to claim 5, wherein the amount is 10 wt%.
solution. 7. The method according to claim 1, wherein the organic polymer is cellulose or polyethylene.
Glycol, polyvinyl butyral, polyvinyl alcohol
Characterized by one or more types of calls
The coating solution according to claim 5.