JPH0633014A - Coating agent composition - Google Patents

Abstract

PURPOSE:To provide a coating agent composition directly applicable to the surface of a material and giving a protecting film having excellent transparency, abrasion resistance, moisture resistance, etc., by dissolving an orthosilicic acid ester and a specific polyvalent metal alkoxyalkoxide in an organic solvent. CONSTITUTION:This coating agent composition is produced by dissolving (A) an orthosilicic acid ester and (B) a polyvalent metal alkoxyalkoxide of the formula M(OR1OR2)n. (M is Al, In, Sb or Zr; R1 and R2 are alkyl or aryl; (n) is constant determined by the atomic valence of M) (e.g. aluminum trimethoxyethoxide) in (C) an organic solvent (preferably alkoxyalcohol such as methoxyethanol or glycol ether such as ethylene glycol dimethyl ether). The amount of the component B is preferably 0.001-0.5mol based on l mol of the component A in the case of imparting the substrate with electrical conductivity. The concentration of the composition is preferably 1-30%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coating composition. More specifically, for example, plastic lenses,
In addition, for transparent plastic materials that are highly transparent and require antistatic ability in addition to surface abrasion resistance, scratch resistance, etc., a protective film is formed on the surface without impairing these functions. It relates to a coating composition.

[0002]

2. Description of the Related Art A transparent plastic material is required to have antistatic properties for the purpose of preventing dust adhesion in addition to abrasion resistance and scratch resistance in order to maintain its function.

Conventionally, in order to impart abrasion resistance and scratch resistance to such transparent materials, a hard coat treatment has been widely performed, and an organic cross-linking curable substance is often used as the treatment material. Therefore, in order to impart antistatic ability to these, measures such as adding a surfactant to the treatment material or adding a conductive material have been made.

However, these methods are, on the one hand, wear resistant,
In many cases, the scratch resistance is impaired, and there is a limit to the addition of a conductive material, and it was difficult to provide all with sufficient performance.

Further, in order to obtain a material having higher resistance, an inorganic coating agent having conductivity may be considered, but conventionally, the vacuum deposition or the sputtering method is surely used for the coating film formation for such purpose. It is supposed to be However, in general, inorganic oxide-based materials have a high melting point and a low vapor pressure, so that the materials that can be vacuum-deposited are extremely limited.

On the other hand, in the sputtering method, it is necessary to prepare a target material suitable for the target composition, and it is difficult to arbitrarily change the composition of the film quality according to the purpose, and it is not a simple method. I can not say. There are other methods such as a chemical vapor deposition (CVD) method, but it is similarly difficult to arbitrarily form a film having a desired composition.

Under such circumstances, as an example of a method capable of easily and arbitrarily producing an arbitrary composition, a polysiloxane sol liquid preparation by hydrolysis of an orthosilicate ester widely used for producing an inorganic coating film is prepared. At that time, a method of obtaining a conductive coating liquid by allowing metal alkoxides such as antimony, tin, and indium to coexist is disclosed (JP-A-2-47165 et al.).

However, in this method, it is not always easy to hydrolyze metal alkoxides such as antimony, tin, indium, etc. faster than orthosilicates to form a uniform composition. It is considered that this is because the metal alkoxides have a rapid progress of hydrolysis and there is not enough time for polymerization and gelation. Therefore, as a means of controlling this, a part of the alkoxyl group of the polyvalent metal alkoxide is used. Or, a method of deriving all of them into a chelate such as acetylacetone or acetoacetate has been devised, but these are too stable as a compound as compared with alkoxide, and conversely hydrolysis, gelation is difficult and crystal precipitation may occur. Problems such as loss of film forming property may occur.

From these problems, a method of directly applying a solution of a polyvalent metal alkoxide in an organic solvent and forming a gel film by moisture in the atmosphere in the applied state has been considered. Since it is difficult to control the decomposition rate, the film composition often becomes non-uniform turbid.

The above problems are the main causes that the polyvalent metal alkoxide has a lot of potential as a functional material and is prevented from being put into practical use.
It is expected that if some kind of control means for arbitrarily controlling gelation is established, it can be applied to a wide range of applications, not limited to coating materials.

[0011]

The present invention solves the above problems and provides a polyvalent metal alkoxide-mixed composition,
It is an object of the present invention to provide a material for forming a metal oxide thin film, which can be directly coated on the surface of a material, thereby obtaining a surface excellent in abrasion resistance, transparency, antistatic property and moisture resistance.

[0012]

Means for Solving the Problems As a result of various investigations conducted by the present inventors for the above-mentioned purpose, the orthosilicic acid ester and a certain metal alkoxyalkoxide dissolved in an organic solvent are The present invention has been completed by finding that the object of (1) is achieved.

That is, the present invention provides an orthosilicate ester and
General formula, M (OR ₁ OR ₂ ) n (where M is Al, I
one or more selected from n, Sb and Zr, and R ₁ and R
₂ represents a linear, branched or cyclic alkyl or aryl group, and n represents a constant determined depending on the valence of the polyvalent metal), and one or more polyvalent metal alkoxyalkoxides And a coating agent composition comprising an organic solvent.

Next, the present invention will be described in more detail. In the polyvalent metal alkoxyalkoxides of the present invention, the R group in the above formula is an alkoxyalkoxyl group represented by —OR ₁ OR ₂ and is a linear, branched or cyclic alkyl or aryl group, respectively. , M is one or more of Al, In, Sb, and Zr, which are used alone or in combination.
Further, in the formula, n is an integer value determined by the valence of the metal, and generally, in the case of Al and In, it is 3, and Zr is 4.

The polyvalent metal alkoxyalkoxide of the present invention is exemplified by aluminum trimethoxyethoxide (Al (OCH ₂ CH _2
2 OCH ₃ ) ₃ ), aluminum triethoxyethoxide (Al (OCH ₂ CH ₂ OCH ₂ CH ₃ ) ₃ ), aluminum trimethoxypropoxide (Al (OC ₃ H ₆
OCH _{3) 3),} aluminum tri-ethoxy propoxide _{(Al (OC 3 H 6 OCH} 2 CH 3) 3), aluminum tri tetrahydrofurfuryl alkoxide and the like, the same applies for other metals. These are selected and used based on easiness of acquisition or production, easiness of handling, solubility, reactivity and the like.

An example of a method for obtaining polyvalent metal alkoxyalkoxides using Al is shown below. Commercially available aluminum triisopropoxide is added and dispersed in ethoxyethanol that has been sufficiently dehydrated and dried, and heated under reflux while expanding sales. As a result, the elimination and exchange of the alkoxyl group proceeds,
This reaction is completed by distilling off the produced low-boiling point isopropanol, and the target aluminum triethoxyethoxide is obtained as an ethoxyethanol solution.

This product can be used as it is for coating purposes by filtering off some insolubles with a membrane filter, etc., but if purification is necessary or desired, the solvent is concentrated and removed, and then normal hexane is removed. Or by repeating extraction and reconcentration with a non-aqueous low boiling solvent such as benzene, or by adding sodium metal to an oxyalcohol solution of an anhydrous halide, it can also be produced by a desalting substitution reaction, depending on the type of metal. May be more appropriate in some cases.

The polyvalent metal alkoxyalkoxides obtained as described above are dissolved in an organic solvent alone or in a combination of a plurality of them together with an orthosilicic acid ester according to the purpose and used as a solution. The ester group of the orthosilicate ester used here is preferably an alkyl group having ₂ to ₈ carbon atoms.

In the present invention, the organic solvent used for dissolving the polyvalent metal alkoxyalkoxide may be a usual organic solvent which does not participate in the reaction, but alkoxy alcohols or glycol ethers are particularly preferable. Examples of these organic solvents include methoxyethanol, ethoxyethanol, methoxypropanol, ethoxypropanol, tetrahydrofurfuryl alcohol, ethylene glycol monoacetic acid ester, and propylene glycol monoacetic acid ester.

The composition ratio of the composition of the present invention is 0.001 to 0.5 mol of polyvalent metal alkoxyalkoxide with respect to 1 mol of orthosilicate ester, particularly for the purpose of imparting conductivity. If the proportion of the polyvalent metal alkoxyalkoxide is less than this amount, the compounding effect is not clear, and if it is too large, the properties as a polysiloxane are lost and white turbidity tends to occur, which is not preferable. The concentration of the solution is not particularly limited as long as polyvalent metal alkoxyalkoxides and the like are completely dissolved, but as a general tendency to obtain a uniform film, a lower concentration than a high concentration is preferred. Is preferable and the range of 1-30% is preferable.

The advantage of using the composition of the present invention is that, unlike a sol-gelation adjusting method in which a hydrolysis reaction is performed in advance, a polyvalent metal alkoxyalkoxide solution is directly coated on a substrate, and therefore a combination of a plurality of metals is used. In this case, the composition as a coating agent does not become nonuniform due to the difference in hydrolyzability.

As the method of coating using the present invention, it is possible to apply various methods such as dipping method, spraying method, spin coating method and roll coater method, which are generally widely practiced, depending on the material shape of the substrate. Since the concentration and the viscosity can be adjusted according to the purpose, the film thickness can be easily controlled.

Further, after forming the first layer on the base material, the second layer and the third layer having different properties from those of the material of the first layer are laminated to form a multilayer film having a composite function. It can also be applied to.

When the base material coated by various coating methods is left as it is, gelation progresses due to moisture in the atmosphere and changes into a hydrous oxide film together with desolvation due to volatilization. The film can be formed more effectively by placing it in an environment and atmosphere controlled by the optimum humidity and temperature for liquefaction and solvent volatilization. Controlling the progress of gelation and the progress of solvent volatilization / desorption is an important factor that determines the success or failure of film formation, and it is desirable to set the optimum state according to the properties of the material for that purpose.

The composition structure of this cured film is presumed to be a high molecular weight hydrous oxide structure polymerized in a network partially containing hydroxyl groups, depending on the type of metal used.

When the substrate for film formation is an organic material such as plastic, the film is used as it is, but glass or metal materials can also be coated. In this case, the substrate should be formed to induce a stronger film. Sintering should be carried out within the permissible range. In this case, as in the case of the sol-gel method, it can be sintered at a relatively low temperature and can form an oxide film sufficiently at about 500 to 600 ° C. However, induction into a composite composed of a combination of a plurality of metals is possible. May require higher temperatures.

In the polyvalent metal alkoxides, the structure in which the alkoxyl group is replaced with the alkoxyalkoxide containing an ether bond is the reason for the stability of the polyvalent metal alkoxyalkoxides against hydrolysis due to the metal molecule by the ether group. It is presumed that there is chelation due to internal or intermolecular coordination, and it is considered that the metal atom is included in the molecule of the alkoxyalkoxide and exhibits stability similar to that of the polyvalent metal acetylacetonates.

That is, the inclusion of the alkoxyalkoxyl group in the polyvalent metal atom improves the solubility in the organic solvent system and suppresses the hydrolyzability, facilitating the uniform progress of gelation, which enables a high quality film formation. Can be said to have been done. Therefore, it is an essential condition in the present invention that the compound form is a polyvalent metal alkoxyalkoxide.

[0029]

INDUSTRIAL APPLICABILITY The present invention is suitable for forming a protective film on the surface of a plastic transparent material which is required to have high transparency such as plastic lens, abrasion resistance and scratch resistance on the surface, and antistatic ability. It is a composition.

[0030]

EXAMPLES The following will supplement the description with examples.

Example 1 400 gr of fully dehydrated ethoxyethanol and 100 gr of commercially available aluminum triisopropoxide were added to a still equipped with a stirrer having a sufficiently dry atmosphere.
The mixture was heated with stirring on an oil bath while maintaining a dry atmosphere with a dry nitrogen gas seal.

The isopropoxyl group of aluminum triisopropoxide undergoes an exchange reaction with ethoxyethanol during the course of this operation and is liberated as isopropanol, which has a boiling point lower than that of ethoxyethanol and is removed by distillation outside the system. To be done. Removal of the generated isopropanol proceeds and the distillation temperature is the boiling point of pure ethoxyethanol 1
After reaching 36 ° C., the reaction was completed, and the product was converted to aluminum triethoxyethoxide (Al (OCH ₂ CH ₂ OC ₂ H ₅ ) ₃ ).

The obtained aluminum triethoxyethoxide was added to a commercially available 20% ethoxyethanol solution of ethyl orthosilicate, and the mixture was sufficiently homogenized in a dry atmosphere, and then a plate containing a bisphenol A type polycarbonate resin as a component. The base material was immersed in this solution, applied by pulling it up, and left to dry at room temperature in the atmosphere,
The gelation gradually progressed and solidified to form a transparent thin film.
Then, it was left to stand still for another 10 hours for complete solidification.

When a residual inorganic solvent was expelled and a complete inorganic thin film was formed, the film was treated in a dryer at 130 ° C. for 2 hours, whereby a transparent film having a hardness withstanding the pencil hardness test 2H could be formed. The surface resistance of this film is 7.5 x 10
¹¹ was shown. It was also confirmed that this coating film does not cause crack peeling even when the substrate is deformed, exhibits sufficient adhesion, and has flexibility.

Example 2 400 gr of sufficiently dehydrated ethoxyethanol and 52.8 gr of commercially available antimony trichloride were added to a reactor equipped with a stirrer whose inside was sufficiently dried, and the dry atmosphere was maintained by sealing with dry nitrogen gas. While stirring, it was dissolved.

After the dissolution was completed, a sufficiently dried ammonia gas was introduced and bubbled with stirring. Simultaneously with the introduction of ammonia gas, the formation of a cloudy slurry due to the formation of ammonium chloride proceeded with heat generation. After the reaction was sufficiently completed, the introduction of ammonia gas was stopped, the dry nitrogen gas was blown in, excess ammonia gas was removed, and immediately after the removal was completed, the ammonium chloride produced by pressure filtration was removed.

The obtained filtrate was concentrated by distillation, the residue was extracted with hexane, the insoluble matter was removed, and then hexane was distilled off to give a pale yellow antimony triethoxyethoxide (Sb (OCH ₂ C
_{H 2 OC 2 H 5) 3} ) to give an oil 30.5gr (78.4% yield).

20 gr of commercially available ethyl orthosilicate was dissolved in 80 gr of ethoxyethanol to prepare a 20% solution. The above-mentioned antimony triethoxyethoxide (3.74 gr) was added to this solution, and the mixture was thoroughly stirred and homogenized in a dry atmosphere, and then the solution was applied to a transparent film of polyethylene terephthalate (PET) stretched in a metal frame with a bar coater. When it was applied to a thickness of 1 mil and dried in air at room temperature, it gradually gelled and solidified to form a transparent thin film.

Thereafter, another 10 times are required for complete solidification.
When left to stand for a while, the residual solvent was expelled, and further treated in a dryer at 130 ° C for 2 hours, the film thickness was 1.5.
It was possible to form a transparent film having a hardness capable of withstanding the pencil hardness test 2H of μm. The surface resistance value of this film was 5 × 10 ¹¹ . It was confirmed that this coating film did not cause crack peeling even when the substrate was deformed, showed sufficient adhesion, and also had flexibility.

Example 3 A sufficiently dehydrated ethoxyethanol and commercially available zirconium tetrachloride were added to a reactor equipped with a stirrer, the interior of which was sufficiently dry, and the mixture was stirred and dissolved while maintaining a dry atmosphere by sealing with a dry nitrogen gas. Let After completely dissolving, a sufficiently dried ammonia gas was introduced and bubbled under stirring, and a cloudy slurry was formed due to the formation of ammonium chloride with no heat generation.

After the reaction was sufficiently completed, the introduction of ammonia gas was stopped, the flow of dry nitrogen gas was switched to blowing, and excess ammonia gas was expelled and removed. Immediately after the purging was completed, the ammonium chloride produced was removed by pressure filtration. The obtained filtrate is concentrated by distillation, the residue is extracted with hexane, the insoluble matter is removed, and the hexane is distilled off to give a light yellow brown zirconium tetraethoxyethoxide (Zr (OCH ₂ CH ₂ OC ₂ H ₅ ) ₄ ) Was obtained as an oil.

21.5 gr of the obtained zirconium tetraethoxyethoxide and 20 gr of ethyl orthosilicate were dissolved and mixed in 100 gr of ethylene glycol dimethyl ether solvent. This solution was applied on a polypropylene film stretched and held in a metal frame by a bar coater to a thickness of 1 mil, and was left to dry at room temperature in the atmosphere having a humidity of 40% as it was. It solidified and a transparent thin film was formed.

After that, a further treatment was carried out for 2 hours in a dryer at 110 ° C., and the residual solvent was expelled to form a complete inorganic thin film. This film was a transparent film having sufficient adhesion and flexibility that did not cause peeling of cracks even when the base material was deformed, and was hard and excellent in scratch resistance. The surface resistance value of this film was 5 × 10 ₁₁ .

Comparative Example 1 An isopropanol solution of aluminum triisopropoxide was mixed in place of the aluminum triethoxyethoxide in Example 1 and an attempt was made to form a film by dip coating on a bisphenol A type polycarbonate resin substrate. As it progressed, it became cloudy and became transparent, and a uniform transparent film could not be prepared.

Comparative Example 2 A coating treatment was carried out in the same manner as in Example 3 except that zirconium tetrabutoxide (n-) was used instead of zirconium tetraethoxyethoxide and ethanol was used as the solvent. The initially transparent coating film lost transparency with the progress of drying and became cloudy and translucent. This one more
When the film surface was subjected to a lapping test after being dried at 10 ° C., it was peeled off and lacked sufficient adhesion.

Claims (3)

[Claims] 1. An orthosilicate ester and a general formula, M (O
R ₁ OR ₂ ) n (provided that M is one or more selected from Al, In, Sb, and Zr, and R ₁ and R ₂ are linear, branched, or cyclic alkyl or aryl groups; n represents one or more polyvalent metal alkoxyalkoxides each represented by a constant determined depending on the valence of the polyvalent metal),
A coating agent composition comprising an organic solvent. 2. The coating agent composition according to claim 1, wherein the ratio of the polyvalent metal alkoxyalkoxides is 0.001 mol to 0.5 mol per 1 mol of the orthosilicate ester. 3. The coating agent composition according to claim 1, wherein the organic solvent is an alkoxy alcohol.