JPH02120327A - Production of compound for coating film - Google Patents

Abstract

PURPOSE:To improve adhesiveness to a base material and surface hardness by reacting a specified organosilicon compd. with a specified organoaluminum compd. in a low-temp. range. CONSTITUTION:An organosilicon compd. (A) of formula R2Si(OH)2 (wherein R is an aliph. or arom. hydrocarbon group) (e.g., diphenylsilanol) and an organoaluminum compd. (B) of formula AlXnY3-n (wherein X is an aliph. or arom. hydrocarbon group; Y is an alkoxy or beta-diketone compd.; n is 2 or 3) (e.g., trialkylaluminum) are mixed in such a way that the mixing ratio of the components A and B (in terms of Si atoms: Al atom) is 3:2-1:1 and the mixture is dissolved in a solvent (e.g., ether) and reacted under stirring at 40 deg.C or lower, especially at a low temp. of -80 to 30 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a compound for coating film that has excellent adhesion to various substrates and surface hardness, The present invention relates to a method for producing a coating film compound using the components as raw materials.

(Prior art and its problems) Modify the surface of molded products such as metals, glass, ceramics, plastics, etc. and articles such as fibers to improve adhesion, surface strength, fF1 contamination resistance, gas permeation resistance, and light reflection. BACKGROUND ART Various physical properties such as light absorption and light absorption have been improved for a long time by forming various coating films such as paints on the surfaces of articles.

However, with this paint coating method, there is a natural limit to the thickness of the coating film, and it is difficult to process a thin film coating on the order of several microns, so thick film coating has been unavoidable.

Further, using a solution of a metal alkoxide and an inorganic metal salt as a raw material, hydrolysis and polymerization of the metal oxide particles are made into a sol, and this is applied to a base article and heated to further advance the reaction, The sol-gel method (Kiyoo Sakuhana, Kagaku Special Edition 1) 2 "Kagaku Doujin f1987+", which involves polymerization to form a coating film, is attracting attention because it can coat extremely thin films with good adhesion.

However, since this sol-gel method is a method in which a coating film is formed by polymerizing through a condensation reaction on the surface to be coated, it is necessary to remove water and alcohol by-products during the reaction and to promote the reaction. for,
Heat treatment is required.

Therefore, this method is limited in that the material to be coated must be heat resistant.

Furthermore, different 2f!s, such as combinations with organosilicon compounds and aluminum alkoxide compounds, can be used. It is also known to use multicomponent coating materials containing one or more metals.

This method has a problem in that it is difficult to control the structure of the coating film at the molecular level. In other words, a condensate containing not only 5i-0-AI, but also 5i-0-5i and Al-0-AI, which are the bonding units of black, is easily generated, and as a result, the physical properties It has become difficult to obtain a coating film that is both physically stable and strong.

Furthermore, after hydrolyzing a specific organosilicon compound,
A method has also been proposed in which a coating film is formed by reacting with aluminum alkoxide, coating the base article by dip coating, then heat-treating at a temperature of 50° C. or higher, and then thermally curing (Japanese Patent Application Laid-Open No. 60-202157). Public bulletin)
.

However, since heat treatment is unavoidable in this method as well, there are restrictions on the types of articles to be coated.

As mentioned above, in order to modify the surface of molded products such as metals, glass, plastics, etc., and articles such as fibers, various coating film raw materials are prepared and applied coatings are performed. properties, surface strength,
Several problems remain to be resolved in physical properties such as stain resistance, gas permeation resistance, and light reflection and absorption.

(Means for Solving the Problems) The present invention uses a specific organosilicon compound and an organoaluminum compound, and by reacting them in a low temperature range, the present invention has excellent properties such as adhesion and stable physical properties. The present invention has led to the production of a coating film compound capable of forming a coating film having the following properties.

That is, according to the invention.

fal-R9 formula, R, Si (OHI 2 formula, R is
An organosilicon compound represented by the following, which represents an aliphatic or aromatic hydrocarbon group, and (bl-formula, AlX1IY3-.

In the formula, X represents an aliphatic or aromatic hydrocarbon group, Y is an alkoxy group or a β-diketone compound, and n is a number of 2 or 3. 2 components of 40
A method is provided for producing a coating compound by reacting at a temperature of 0.degree. C. or lower.

Effect C) In the present invention, the reaction (condensation reaction) of the two components described above can be carried out at a low temperature of 40°C or less without heat treatment, so properties such as heat resistance required of the material to be coated are relaxed. 1. For example, it becomes possible to effectively coat materials that are easily deformed due to heat.

Furthermore, when the coating film compound obtained according to the present invention is used, the coating film has extremely stable physical properties such as adhesion, surface strength, stain resistance, gas permeation resistance, and light reflection and absorption. Although it is not yet clear that the compound produced by the present invention is composed only of substantially regular 5i-0-AI bonding units, 5i-0-5i or Al-0-AI It is presumed that this is because it contains almost no bonding units such as .

That is, in the research process leading to the present invention, the present inventors selected various organosilicon compounds and organoaluminum compounds, dissolved them in a solvent, and investigated their reactions at low temperatures.
I discovered the following interesting fact.

Among these facts, the following reaction can be cited as a model of a characteristic reaction for understanding the present invention.

That is, triisobutylaluminum (A 1 fi-C4H9) 3) was used as an organoaluminum compound that has the property of selectively reacting with protons of hydroxyl groups at low temperatures, and the solvent tetrahydrofuran (THF) J was used as an organosilicon compound. This was dissolved (t-C, H, fc
) 1212Si 10HI ) was used, the reaction was stirred at 0° C. for 1 hour, and the recovered condensate was used as a model.

This reaction condensate was examined using nuclear magnetic resonance (NMR) and gas chromatography (GC), and the production rate and structure of the reaction product were investigated, and the results shown in FIG. 1 were obtained.

From the measurement results of this nuclear magnetic resonance (NMR), the integral value of the methyl peak of the isobutyl group (δ = 1.32 to 1.34) with the internal tank 'ts < naphthalene) shows that in all cases, the reactant It was revealed that the product was obtained with a high yield of 99% or more.

On the other hand, from the gas chromatograph results, 5i-0-5i
No bonds or products of random blocks of Al-0-AI bonding units were observed, revealing the fact that the reaction product was composed only of Al-0-5i bonding units.

From this result, the reaction of the model condensate can be considered to be expressed by the following equation.

Al 1i-C41)e) 3+ t-CJ9(C1l
a) zsi fOH1→t-C4H9(CH312S
i-0-Al (i-C4H912+ fi-C41)
From the above knowledge, the organoaluminum compound used as a raw material has the formula: AIXnY1-. (In the formula, X is an aliphatic or aromatic hydrocarbon group, Y is an alkoxy group or a β-diketone compound, and n is 2 or 3
is the number of ), and on the other hand, an organosilanol compound represented by the formula R,Si (0 former 2 (wherein R is an aliphatic or aromatic hydrocarbon group)), and It is estimated that the reaction product is composed only of Al-0-5i bond units.

Therefore, the condensate produced by the present invention is 5i-0
It contains almost no -3i or Al-0-Al bonding units, and as a result, it is possible to obtain a coating that is physically stable and strong.

(Preferred Embodiment of the Invention) Godankyue stop coating 1 In the organosilicon compound used in the present invention 2, -
Organosilanols with the formula RzSx fOH) z are used.

In the formula, the group R is an aliphatic or aromatic group, such as methyl,
These organic silanols, which represent groups such as butanol, vinyl, phenyl, and methylphenyl, can be used singly or in combination of two or more. Therefore, diphenylsilanol [fc6H512si (0 old 21) is most preferably used.

Hand aluminum A product In the present invention, the organoaluminum compound to be reacted with the above-mentioned organosilicon compound is - Formula AI
Those represented by X, Y, etc. may be used alone or in combination of two or more.

Here, n is a number of 2 or 3.

Further, the group X represents an alkyl group having 1 to 5 carbon atoms such as methyl and ethyl.

Further, the group Y represents an alkoxy group such as methoxy, ethoxy, butoxy or benzyloxy, or a group of a β-diketone compound such as acetylacetone or benzoylacetone.

In the present invention, trialkylaluminum and diethylmonoethoxyaluminum are particularly preferably used.6 In addition, in the present invention, it is recommended to dissolve the organosilicon compound and the organoaluminum compound in a solvent in advance before use. desirable.

As these solvents, various solvents that do not react with the raw material compounds, such as ethers, halogenated hydrocarbons, or aromatic systems such as toluene, can be suitably used depending on the purpose. It is also possible to use a mixed solvent of

Further, the mixed reaction solution of an organosilicon compound and an organoaluminum compound dissolved in the solvent of the present invention can be stored and used at room temperature within a range where the solvent can be stored at room temperature.

In addition, it is preferable to use this mixed reaction solution after replacing it with an inert gas such as nitrogen gas in order to smoothly carry out one reaction and coating without causing troubles such as oxidation.

In order to stably form the coating film of the present invention and effectively produce a condensate consisting only of 5i-0-Al bond units, the mixing ratio of the raw materials (a) and (b) must be adjusted. Silicon atom (Sil) and aluminum atom (A1)
It is desirable to select an atomic ratio (Si:Al) of 3:2 to 1:1.

When this mixed atomic ratio is shifted from the ratio of 3=2 or l:1 in either ratio direction, it becomes impossible to generate a condensate of 5i-0-Al bond units with a high probability of selectivity, and other The bond unit 5j-0-5i bond and A
There is a tendency for a mixture of l-0-Al bonds to be generated.

The reaction conditions for producing the coating film of the present invention include reacting an organosilicon compound and an organoaluminum compound dissolved in the above-mentioned solvent at a low temperature range of 40°C or lower, especially -80 to 30°C, with stirring. In particular,
There is no need to hydrolyze or heat the reaction materials.

Furthermore, since the substances produced by the reaction of the present invention are all low-boiling point gases (hydrocarbon compounds), it is possible to volatilize these by-products at room temperature, and in this respect, special heating, etc. means are not required.

As a method for coating equipment with the coating film of the present invention, the surface of the equipment to be coated is cleaned mechanically or with a solvent or water, and then dipping is performed.
Coating methods commonly used in the art, such as a coating method, a spray method, and a dripping method, can be employed.

In this case, in order to improve the workability of the coating stock solution during coating and improve the smoothness of the coating film, it is also possible to use a surfactant, etc. In particular, blocking with dimethylsiloxane or alkylene oxide or Graft copolymers and the like are effective.

Furthermore, in order to color the coating film, it is possible to add and blend various dyes, pigments, metal elements, etc., fillers, and dissolve organic polymers. Furthermore, it is possible to improve coating properties and adhesion to the substrate. It is also easily possible to further improve the practical physical properties such as.

The film thickness of the coating film coated by the method of the present invention can be changed by the coating method (for example, the number of dippings, etc.), the solid content concentration in the coating raw material liquid, and the like. However, according to the manufacturing method according to the present invention, 0.000.
Thicknesses of 0.01 to 1.0 microns, preferably 0.1 to 0.5 microns are commonly utilized. If you want to make the film even thicker, repeat the coating process to increase the film thickness.
It is also possible to have a thickness of 0 microns. However, when the film thickness is made thicker than 2 microns in one coating process, the coating film tends to be prone to cracks and cracks, which is not preferable.

Furthermore, in order to improve the functionality of surface physical properties, for example, for the purpose of antistatic properties, colloidal dispersions of hydrolysates such as methyl silicate, ethyl silicate, propyl silicate, butyl silicate, or polymeric silica or sol-like water Alternatively, an alcohol dispersion is preferably used. In addition, for the purpose of improving the refractive index and flexibility of the coating film, a hydrolyzate of an organosilicon compound other than the component (a) may be used in combination, as long as the coating surface hardness and stain resistance are not impaired. 6 or more compounds that can be used in combination can be blended at a blending ratio that does not reduce the coating film properties and coating workability obtained from the coating film of the present invention, and is preferably blended with 100 parts by weight of component (a). The amount is 5 to 200 parts by weight.

The base materials to be coated to which the coating film of the present invention is applied include metals such as iron, aluminum, copper, lead, titanium, silver, gold, and various types of alloys; inorganic glasses; silica, alumina, Fired products of natural minerals such as zirconia, silicon carbide, carbon, magnesha, chromium, karja, etc. and natural minerals composed of these compounds, individually or in mixtures, glassy enamel, hydration-hardened cement products,
Ceramics made of titanium carbide, titanium nitride, tungsten carbide, molybdenum, niobium, yttrium oxide, etc.; Synthetic gemstones made of artificial diamond, boron carbide, iron oxide, chromium oxide, corundum, emery, garnet, flint, etc.; polymethylmethane Plastics such as freight, acrylonitrile-styrene copolymer, polycarbonate, luroseate, cross-linked polymethyl metaphreite, polyvinyl chloride, epoxy resin, diethylene glycol bisallyl carbonate polymer, polyamides, polyesters, etc.: Molding of wood, etc. Examples include textile products and textile products.

Further, for the purpose of improving the adhesion of the substrate which is the material to be coated according to the present invention, it is also preferable to apply the present invention to articles which have been previously subjected to a trough surface treatment or a brimer treatment.

(Effects of the Invention) According to the present invention, by selecting an organosilicon compound and an organoaluminum compound as raw materials and reacting them at a low temperature, a compound composed only of a condensate of 5j-0-AI bonding units can be produced. When coating on each 4ffi base material article, we provide a coating film with excellent physical properties such as adhesion, body surface strength, stain resistance, gas permeation resistance, light reflection and absorption, and its manufacturing method. It was done. Thus, articles coated with the coating film of the present invention have the advantage of having excellent appearance characteristics, and have the advantage of having excellent mechanical strength of the appearance surface.

(Example) Specific examples of the present invention will be described below with reference to Examples.

(1) Preparation of coating stock solution Commercially available diphenylsilanol and triisobutylaluminum (manufactured by Tokyo Kasei Co., Ltd.) were selected as the raw organosilicon compound and organoaluminium compound, respectively, and the commercially available reagent tetrahydrofuran was selected as the solvent. 6. To prepare the stock solution, place 1 mmol of diphenylsilanol in a 100 ml stainless steel reactor equipped with a stirring rotor, add 5 ml of tetrahydrofuran as a solvent, and stir for 10 minutes using a magnetic stirrer. Then, while keeping the reactor at 0° C. with ice from the outside, 1 mmol of triisobutylaluminum was slowly injected dropwise, and stirring was continued for an additional hour. After that, the temperature was returned to 25°C, and stirring was continued until gas generation ceased to prepare a coating stock solution-8 consisting of a condensate condensed to a degree of polymerization with an average molecular weight of about 1200.9(2) For coating Preparation of Stock Solution-B A coating stock solution-B was prepared in the same manner as in the preparation method (1) except that the amount of diphenylsilanol added was 1.5 mmol.

(3) Stock solution for coating - The organosilicon compound and organoaluminum compound used as raw materials for the preparation of 〇 are each given an Ichi!
! Diphenylsilanol and diethylmonoethoxyaluminum (manufactured by Tokyo Kasei Co., Ltd.) were selected, and tetrahydrofuran (commercially available sample 1) was selected as the solvent.

In the same manner as in the preparation method of fl), 1 mmol of tetrahibinophenol and diethylmonoethoxyaluminum lm
mol is reacted and the resulting white solid is collected.

After removing the solvent tetrahydrofuran by filtration, reagent-grade 2-buknol 5 was added to the recovered white solid.
mL was poured into a mouth and dissolved with stirring to prepare a stock solution for coding.

(4) The organosilicon compounds and organoaluminum compounds used as raw materials for the preparation of coating stock solutions are available from the market, respectively. Diphenylsilanol and triisobutylaluminum from Ifii (manufactured by Tokyo Kasei Co., Ltd.) were selected, and toluene, a commercially available reagent, was selected as the solvent.

Proceed in the same manner as fl), except that the amount of toluene added is 5 ml, and the reaction is allowed to proceed with continued stirring at a temperature of 25 ° C. to form a solution containing a condensate having a viscosity of about 500 cp.
A stock solution for coating -〇 was prepared.

(5) Preparation of coating stock solution-E The commercially available reagent toluene was selected as the solvent, and t1+ except that the amount of diphenylsilanol added was 1.5 mmol.
Coating stock solution-E was prepared in the same manner as above.

Each coating stock solution prepared by the method described in F was -10
It was stored in a refrigerator maintained at ℃ (storage at room temperature is of course possible).

A glass plate, an iron plate, an aluminum plate, and a copper plate were selected as the substrates to be coated. Each of these substrates was thoroughly washed with water and a solvent.

The above-mentioned coating solution was applied to each base material using a dipping method (dipping method: pulling speed of 80 cm/m1ni). After application, air-dry at room temperature to evaporate the solvent and apply the coating film onto the base material. By forming
Each test piece was prepared.

Each test piece after coating was tested for film thickness, pencil scratch surface height, and stain resistance.

The membrane pressure was measured using the stylus method using a Talyst method.
ep) device (manufactured by Laukstayler Hopson).

The surface hardness when scratched with a pencil was measured using a tester described in JIS standard K54 old, and the pencil hardness at the time of use was expressed.

1 staining property is 90% in the red dye bath (5% water dispersion).
The samples were immersed at °C for 30 minutes, and the state of staining thereafter was visually determined, and those with no coloration were rated as "good".

Ifij thermal properties test the coated test piece to 350
After being exposed to a constant temperature chamber at ℃ for 3 hours, the state of the coating film (cracks, blisters, and adhesion) of the test piece was observed under a microscope, and it was found that there were no cracks or blisters, and there was sufficient adhesion. Those with this were classified as having heat resistance.

The above results are shown in Table 1 below.

[Brief explanation of the drawing]

Figure 1 shows the nuclear magnetic resonance of triisobutylaluminum (
FIG. 2 is an NMR diffraction diagram of t-butyldimethylsilanol, and FIGS. 3 to 5 each show an Al/Si ratio of 1/1. l/2. It is an NMR diffraction diagram of a product obtained when triisobutylaluminum and t-butyldimethylsilanol are reacted so that the ratio is 1/3.

Claims (2)

[Claims] (1) (a) General formula, R_2Si(OH)_2 formula, R
represents an aliphatic or aromatic hydrocarbon group, and (b) general formula, AlX_nY_3_-_n, where X represents an aliphatic or aromatic hydrocarbon group, and Y is an alkoxy group or a β-diketone compound, and n is a number of 2 or 3.
A method for producing coating compounds by reacting at temperatures below ℃. (2) The method according to claim (1), wherein the reaction of the two components is carried out at a temperature of 30 to -80°C.