JP2014091672A - Hafnia and/or zirconia sol, method for manufacturing the same, and cured film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a HfOsol and/or ZrOsol capable of forming, despite being amorphous, a HfOand/or ZrOfilm having a high hardness at a low energy; a method for manufacturing the same; and a hard film which is a HfOand/or ZrOfilm having a high hardness despite being amorphous.SOLUTION: The provided HfOsol and/or ZrOsol comprises an organic acid, amorphous HfOand/or ZrOand is obtained by converting, in the absence of a particle growth regulator, a Hf compound and/or Zr compound into hafnium hydroxide and/or zirconium hydroxide by using aqueous NHand by hydrothermally treating the obtained aqueous liquid including hafnium hydroxide and/or zirconium hydroxide in a yet-to-be-aged state in the presence of an excess of an organic acid with respect to 1 mole of HfOand/or ZrO; a method for manufacturing the same and a cured film of the same are also provided.

Description

  The present invention relates to a hafnia and / or zirconia sol, a method for producing the same, and a cured film, and more particularly, a hafnia and / or zirconia sol that can form a hardened cured film with low energy while being amorphous. And a high hardness cured film.

  Conventionally, Patent Literature 1 proposes a “method for producing a sol in which zirconia fine particles are dispersed”.

The method for producing a sol described in Patent Document 1 is as follows.
A method for producing a sol in which zirconia fine particles having an average particle diameter in the range of 5 to 100 nm are dispersed, comprising the following steps (a) to (e).

(a) a step of preparing a zirconium hydroxide gel dispersion by adding an alkaline aqueous solution to a zirconium compound aqueous solution in the presence of a particle growth regulator;
(b) a step of washing the zirconium hydroxide gel,
(c) aging the washed zirconium hydroxide gel dispersion;
(d) washing the aged zirconium hydroxide gel, and
(e) Hydrothermal treatment of the washed dispersion of zirconium hydroxide gel in the presence of a particle growth regulator. Carboxylic acid or carboxylate as the “particle growth regulator” in step (a) of claim 1 It is disclosed that hydroxycarboxylic acid and hydroxycarboxylate are used (paragraph 0011).

  The aging in the step (c) in claim 1 is performed by heating to 100 to 250 ° C. (see paragraphs 0016 and 0017).

  The particle growth regulator in the step (e) in claim 1 is the same as the grain growth regulator in the step (a). When the zirconium hydroxide is converted into zirconia, the grain growth regulator is used with respect to 1 mol of zirconia. It is said that the agent is preferably used in the range of 0.05 to 0.8 mol, and if the amount of the particle growth regulator added exceeds 0.8 mol, particle growth or crystallization is greatly suppressed. It may be difficult to obtain a zirconia sol having a desired particle size because it may take a long time to grow to a desired particle size or because of insufficient crystallization (paragraph 0019). reference).

  The zirconia sol disclosed in Patent Document 1 includes zirconia in the form of crystals (see paragraph 0028).

This Patent Document 1 does not describe the hardness of a cured film of zirconia gel formed from the zirconia sol disclosed in Patent Document 1.
The following documents are known as documents showing background technology related to hafnia sol or zirconia sol.
Patent Document 2 includes a) a step of preparing a zirconium hydroxide sol, b) a step of adding an inorganic acid, c) a step of hydrothermally treating the sol, and d) a step of recovering a colloidal solution of zirconia particles. A method for preparing a colloidal solution of agglomerated zirconia particles is disclosed. In the preparation method described in Patent Document 2, an inorganic acid is essential in the hydrothermal treatment step (see Paragraph No. 0024 of Patent Document 2), and finally formed sols are tetragonal and monoclinic zirconia ( (See paragraph number 0027 of Patent Document 2).
Patent Document 3 discloses a first step of producing an aqueous solution containing an anionic basic inorganic complex using a neutralization reaction between a metal salt and a salt containing a rare earth element and a quaternary ammonium salt, and hydrothermal treatment of the aqueous solution. Thus, there is disclosed a method for producing a basic metal oxide-dispersed transparent sol aqueous solution having a second step of producing a metal oxide doped with the rare earth element. The sol obtained by the production method described in Patent Document 3 always contains rare earth elements.
Patent Document 4 discloses a method for producing a zirconia sol comprising the following steps (a) to (d), in which zirconia fine particles having an average particle diameter in the range of 5 to 30 nm are dispersed.
(a) a step of adding an alkali component to an aqueous zirconium compound solution to prepare a dispersion of zirconium hydroxide gel,
(b) a step of washing the zirconium hydroxide gel,
(c) adding an alkali metal hydroxide aqueous solution and an aqueous hydrogen peroxide solution to the washed zirconium hydroxide gel dispersion to dissolve the zirconium hydroxide gel;
(d) Next, a hydrothermal treatment at 40 to 300 ° C.
In the method for producing a zirconia sol disclosed in Patent Document 4, a sol obtained by adding an alkali metal hydroxide aqueous solution and a hydrogen peroxide aqueous solution to a zirconium hydroxide gel dispersion is hydrothermally treated.
Patent Document 5 discloses that a zirconium salt (B2) is heated at 60 to 110 ° C. in an aqueous medium containing a quaternary ammonium carbonate at 110 to 250 ° C. following steps (i) and (i). A method for producing an alkaline zirconia sol comprising the step (I) of mixing the alkaline zirconia sol (A) obtained by the method comprising the step (ii) of hydrothermal treatment with the basic zirconium carbonate salt (B1), It is disclosed.
Patent Document 6 discloses a method for producing a zirconia sol comprising the following steps (A) and (B).
(A): a step of mixing the dicarboxylic acid compound and the zirconium compound in a ratio of more than 1 mole and 10 moles or less of the dicarboxylic acid compound with respect to 1 mole of the zirconium atom of the zirconium compound in an aqueous medium.
(B): A step of adding a water-soluble organic base to the mixture at a ratio of 0.7 to 2.5 mol with respect to 1 mol of the dicarboxylic acid compound contained in the mixture obtained in the step (A), followed by hydrothermal treatment.
Patent Document 7 discloses a hard film formed on a plastic surface, which is selected from the group consisting of hafnia sol and / or zirconia sol, (meth) acrylic acids, (meth) acrylates, and vinyl ethers. A hard film characterized by having a cured body layer obtained by curing a sol composition containing at least one of the above and a method for producing the same are disclosed.

  The present invention has been completed based on the discovery that a high-hardness hafnia gel or zirconia gel can have high hardness even if the hafnia or zirconia is not crystalline.

JP 2006-143535 A Special table 2010-523451 gazette JP 2010-247014 A JP 2009-167085 A PCT International Publication No. WO2007 / 000926 JP 2008-290896 A JP 2005-336466 A

  An object of the present invention is to provide a hafnia sol and / or zirconia sol that can form a hafnia and / or zirconia film having high hardness while being amorphous, with low energy. Another object of the present invention is to provide a production method capable of producing a hafnia sol and / or zirconia sol capable of forming a hafnia and / or zirconia film having a high hardness with low energy while being amorphous. . Still another object of the present invention is to provide a hard film that is an amorphous but high hardness hafnia and / or zirconia film that can be formed with low energy.

Means for solving the problems are as follows:
(1) An aqueous liquid containing hafnium hydroxide and / or zirconium hydroxide obtained by converting a hafnium compound and / or a zirconium compound into hafnium hydroxide and / or zirconium hydroxide with ammonia water in the absence of a particle growth regulator. Without aging, the aqueous liquid is obtained by hydrothermal treatment in the presence of an excess of an organic acid with respect to 1 mol of hafnia and / or zirconia, containing the organic acid, and amorphous hafnia and / or A hafnia sol and / or zirconia sol characterized by containing amorphous zirconia,
(2) The hafnia sol and / or zirconia sol according to (1), wherein the hafnium compound is a hafnium alkoxide or a hafnium salt, and the zirconia compound is a zirconium alkoxide or a zirconium salt,
(3) The organic acid is formic acid or acetic acid, and the hydrothermal treatment is the hafnia sol and / or zirconia sol according to (1) or (2), wherein the heating temperature is 80 to 140 ° C.
(4) the Hafuniazoru and / or zirconia sol, described in any one of (1) to (3) having absorption in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 at FT-IR spectrum of the gel Hafnia sol and / or zirconia sol,
(5) An aqueous liquid containing hafnium hydroxide and / or zirconium hydroxide obtained by converting a hafnium compound and / or zirconium compound into hafnium hydroxide and / or zirconium hydroxide with ammonia water in the absence of a particle growth regulator. Without the aging of the aqueous liquid, hydrothermal treatment of the aqueous liquid in the presence of an excess of an organic acid with respect to 1 mol of hafnia and / or zirconia, is a method for producing hafnia sol and / or zirconia sol,
(6) The hafnia sol and / or zirconia sol production method according to (5), wherein the hafnium compound is a hafnium alkoxide or a hafnium salt, and the zirconium compound is a zirconium alkoxide or a zirconium salt.
(7) The organic acid is formic acid or acetic acid, and the hydrothermal treatment is a method for producing a hafnia sol and / or zirconia sol according to (5) or (6), wherein the heating temperature is 80 to 140 ° C.
(8) the Hafuniazoru and / or zirconia sol, described in any one of (5) to (7) having an absorption in the 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 at FT-IR spectrum of the gel A method for producing a hafnia sol and / or zirconia sol,
(9) Curing the coating film formed by applying the hafnia sol and / or zirconia sol according to any one of (1) to (4) on a substrate by ultraviolet irradiation and / or heating. A cured film characterized by
(10) the Hafuniazoru and / or zirconia sol is a cured film according to (9) having absorption in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 at FT-IR spectrum of the gel.

  The hafnia sol and / or zirconia sol of the present invention contains amorphous hafnia and / or zirconia and contains an organic acid. Since the amorphous hafnia and / or zirconia according to the present invention is produced by hydrothermal synthesis in the presence of an organic acid, the ions of hafnia and / or zirconia are more orderly arranged and not a crystal structure. It is in an amorphous state close to the crystal structure. Further, when a hard film is formed, an organic acid exists between hafnia and other hafnia and / or between zirconia and other zirconia. The presence of an organic acid strengthens the bond between hafnia particles and hafnia particles, the bond between zirconia particles and zirconia particles, or the bond between hafnia particles and zirconia particles, or the bond between hafnia particles and / or zirconia particles and the substrate. Becomes solid. The organic acid present in the hafnia sol and / or zirconia sol improves applicability when the hafnia sol and / or zirconia sol is applied to the substrate. Therefore, the operation of applying the hafnia sol and / or zirconia sol onto the substrate is easy, and the hafnia sol and / or zirconia sol coating film can be uniformly formed on the substrate. The hafnia sol and / or zirconia sol according to the present invention can form a hard film with low energy. Here, low energy means, for example, when the energy source is ultraviolet rays and / or heat, irradiation with ultraviolet rays or heating in a short time is shorter than before. Thus, the hard film according to the present invention does not easily peel off from the substrate, and has a pencil hardness of 6H or more.

  In addition, when measuring hardness with pencil hardness, the hardness is evaluated as a contribution by both the surface hardness of a film | membrane and the adhesiveness of a film | membrane and a board | substrate. That is, even if the surface of the film is hard, a film having low adhesion between the film and the substrate is easily peeled off when pulled by a pencil core, and is evaluated as a film having low hardness. Therefore, a film having a high pencil hardness has a high surface hardness and a high adhesion between the film and the substrate.

  The method for producing hafnia sol and / or zirconia sol of the present invention is a method for producing amorphous hafnia and / or zirconia, and a film made of amorphous hafnia and / or zirconia has a low pencil hardness, but a pencil of 6H or more. A hafnia sol and / or zirconia sol capable of forming a film having hardness can be obtained.

  Although the hard film of the present invention is amorphous hafnia and / or zirconia, it contains an organic acid to form an amorphous structure close to a crystal structure by orderly arranging hafnia and / or zirconia ions. Therefore, the surface hardness is large, and the adhesion to the substrate is high, and therefore, the pencil hardness as a whole is 6H or more.

FIG. 1 shows the FT-IR spectrum of the zirconia gel obtained by removing the solvent from the zirconia sol obtained in Example 1 and the zirconia gel thin film obtained by removing the solvent from the zirconia sol obtained in Comparative Example 1. It is IR chart figure which shows together the FT-IR spectrum of.

  First, a method for producing a hafnia sol and / or zirconia sol according to the present invention will be described.

  In the production method according to the present invention, the hafnium compound and / or zirconium compound is converted into hafnium hydroxide and / or zirconium hydroxide with ammonia water in the absence of a particle growth regulator, and the resulting hafnium hydroxide and / or hydroxide is obtained. The aqueous liquid is hydrothermally treated in the presence of an excess of an organic acid with respect to 1 mol of hafnia and / or zirconia without aging the aqueous liquid containing zirconium.

  The said particle growth regulator is a compound described in the paragraph number 0011 column of the said patent document 1, Specifically, they are carboxylic acid, carboxylate, hydroxycarboxylic acid, and hydroxycarboxylate. In the production method according to the present invention, the particle growth regulator is not used. Patent Document 1 states that “when the molar ratio (Cm / Zm) of the number of moles of zirconium compound (Zm) to the number of moles of grain growth regulator (Cm) is less than 0.01”. As a result, a heterogeneous zirconium hydroxide hydrogel is formed. For this reason, the particle size of the zirconia sol obtained by hydrothermal treatment in the step (e) described later may not be uniform, or the average particle size may not be 100 nm or less. Is shown. In the production method of the present invention, the hafnia sol and / or zirconia sol crystals are not grown, and therefore the particle diameter of the crystals is not focused. Therefore, it is not necessary to add the particle growth regulator.

  Examples of the hafnium compound include hafnium alkoxide and hafnium salt. A preferred hafnium compound is a hafnium salt. Examples of the hafnium salt include hafnium chloride oxide, hafnium tetrachloride, hafnium tetrafluoride, hafnium tetrabromide, and hafnium tetraiodide. Of these, hafnium tetrachloride and hafnium chloride are preferable.

Examples of the zirconium compound include zirconium alkoxide and zirconium salt. The preferred zirconium compound is a zirconium salt. For example, Patent Document 7 discloses that the zirconium salt is suitable as a raw material for producing a zirconia sol in the same manner as zirconia alkoxide.
Examples of the zirconium halide, which is an example of the zirconium salt, include zirconium chloride, zirconium tetrafluoride, zirconium tetrabromide, zirconium tetraiodide, and zirconium dichloride oxide octahydrate. Among these, zirconium dichloride oxide octahydrate is particularly preferable.

In the production method of the present invention, the hafnium compound and / or zirconium compound is converted into hafnium hydroxide and / or zirconium hydroxide with ammonia water in the absence of the particle growth regulator, and the resulting hafnium hydroxide and / or hydroxide is obtained. Hydrothermal treatment is performed without aging the aqueous liquid containing zirconium.
The suitable concentration of ammonia water is usually 1 to 29% by mass.

  Patent Document 1 discloses “ripening zirconia hydroxide” as the step (c). As described in paragraphs 0016 and 0017, the aging in Patent Document 1 is suggested to prevent the formation of coarse particles and make the particle size distribution uniform. The ripening in Patent Document 1 achieves uniform crystallization by suppressing grain growth as described in paragraph 0019 of the paragraph. On the other hand, the production method of the present invention does not produce crystallized hafnia sol and / or zirconia sol. Therefore, in the production method of the present invention, it is not necessary to ripen hafnia hydroxide and / or zirconia hydroxide. Rather, it is not preferable because ripening forms crystalline hafnia sol and / or zirconia sol. Therefore, in the production method of the present invention, an aqueous liquid containing hafnium hydroxide and / or zirconium hydroxide is supplied to the next hydrothermal treatment step without going through an aging step.

  Hydrothermal synthesis in the production method of the present invention is performed by heating the aqueous liquid to 80 to 140 ° C. in the presence of an organic acid. The heating time is usually 2 to 15 hours. Hydrothermal synthesis is performed using a pressurized container or a sealed tube.

  Examples of the organic acid include alkyl carboxylic acids, preferably formic acid and acetic acid. The addition amount of the organic acid is excessive with respect to hafnium hydroxide and / or zirconium hydroxide. Here, when only hafnium hydroxide is present in the aqueous liquid, the excess amount is 1 mole or more, preferably 1 to 50 moles of organic acid with respect to 1 mole of hafnium hydroxide. When only zirconium is present, the amount of the organic acid is 1 mole or more, preferably 1 to 50 moles per mole of zirconium hydroxide, and when hafnium hydroxide and zirconium hydroxide are present in the aqueous liquid, It means that the organic acid is 1 mol or more, preferably 1 to 50 mol, per 1 mol of the total of hafnium oxide and zirconium hydroxide. Amorphous hafnia and / or amorphous produced by sol-gel method in the absence of organic acid by coordinating organic acid to hafnia and / or zirconia by hydrothermal synthesis when organic acid is present in excess in aqueous liquid Compared to zirconia, hafnia and / or zirconia is in an amorphous state having an ordered structure.

  In the hydrothermal synthesis in the production method of the present invention, amorphous hafnia and / or amorphous zirconia is generated, and an organic acid is coordinated between the amorphous hafnia and hafnia, and / or amorphous. An organic acid is coordinated between zirconia and zirconia. By coordinating the organic acid between amorphous hafnia and hafnia, the bond between amorphous hafnia and hafnia is strengthened, and the adhesion to the substrate is enhanced. The same effect is obtained when the organic acid is coordinated between amorphous zirconia and zirconia. In the hafnia sol and / or zirconia sol produced by the production method of the present invention, the hafnia sol and / or zirconia sol is uniformly applied to the substrate by the presence of an organic acid that binds hafnia to each other or zirconia. In addition, the surface of the cured film obtained by coating is less likely to be damaged, and the cured film itself is strongly adhered to the substrate, so that the pencil hardness of the cured film is 6H or more.

The presence of an organic acid in the hafnia sol and / or zirconia sol can be obtained by measuring an FT-IR spectrum of the hafnia gel and / or zirconia gel obtained by removing the solvent from the hafnia sol and / or zirconia sol. it is clear from the fact that the absorption characteristic is observed in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 in the spectrum. The "absorbed in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 is observed" is in the present invention, the phenomenological observed absorption in the vicinity thereof including "1013 cm ^-1, also 878Cm ^-1 It means that absorption is observed in the vicinity thereof including “,” and does not mean that it does not deviate even slightly from “1013 ± 15 cm ⁻¹ and 878 ± 15 cm ⁻¹ ”.

The hard film according to the present invention is obtained by curing the hafnia sol and / or zirconia sol. The hard film according to the present invention is obtained by measuring the FT-IR spectrum of the gel obtained by removing the solvent from the hafnia sol and zirconia sol. It is also one of the characteristics that the FT-IR spectrum obtained by the above has peaks at 1013 ± 15 cm ⁻¹ and 878 ± 15 cm ⁻¹ .

  The hafnia sol and / or zirconia sol according to the present invention produced by the production method according to the present invention is a hard film of hafnia and / or zirconia with less energy, that is, with a short heating time or ultraviolet irradiation time, for example, at least 1 minute. It can be.

Example 1
Zirconium chloride oxide octahydrate _{(ZrOCl 2 · 8H 2 O)} 5.48g of (0.017 mol) was dissolved in H ₂ O 32.0 g. To this solution, 3.5 mL of 29% aqueous ammonia was slowly added to obtain a white precipitate (zirconium hydroxide). The white precipitate was suction filtered and washed with H ₂ O until pH 7 or lower. After adding 20.0 g of H ₂ O to the washed white precipitate, 24.0 g (30 times mol) of 98% formic acid (HCOOH) was added with stirring. Subsequently, H ₂ O was added so that the total amount of zirconia sol became 80.0 g, and this was put into a Teflon (registered trademark) inner cylinder, and further put in an autoclave and sealed. This was heated at 120 ° C. for 4 hours to be hydrothermally synthesized and cooled to obtain a hydrothermal zirconia sol.

  This zirconia sol is applied on a non-alkali glass that has been washed under high humidity (99% humidity) under a coating condition of 500 rpm / 5 sec → 2000 rpm / 30 sec using a spinner (K-3959D-1, Kyowa Riken) A zirconia gel film was prepared.

The zirconia gel film was irradiated with ultraviolet rays for 1, 5 and 10 minutes using a high-pressure mercury lamp (H1000L, Toshiba Lighting & Technology) to obtain a zirconia thin film A.
On the other hand, zirconia gel was obtained by removing the solvent from a part of the hydrothermal zirconia sol, and FT-IR spectrum measurement was performed on the zirconia gel, and the obtained FT-IR spectrum is shown in FIG.

(Example 2)
A zirconia thin film B was obtained in the same manner as in Example 1 except that the hydrothermal time in Example 1 was changed to 6 hours.

(Example 3)
A zirconia thin film C was obtained in the same manner as in Example 1 except that the amount of formic acid in Example 1 was changed to 14.36 g and the hydrothermal time was changed to 6 hours.

(Example 4)
A zirconia thin film D was obtained in the same manner as in Example 1 except that the amount of formic acid in Example 1 was changed to 4.79 g and the hydrothermal time was changed to 6 hours.

(Example 5)
A zirconia thin film E was obtained in the same manner as in Example 1 except that the amount of formic acid in Example 1 was changed to 14.36 g and the hydrothermal time was changed to 15 hours.

(Example 6)
A hafnia thin film F was obtained in the same manner as in Example 1 except that 5.44 g of hafnium chloride was used instead of zirconium chloride octahydrate in Example 1.

(Example 7)
A hafnia thin film G was obtained in the same manner as in Example 6 except that the hydrothermal time in Example 6 was changed to 6 hours.

(Example 8)
A hafnia thin film H was obtained in the same manner as in Example 6 except that the amount of formic acid in Example 6 was changed to 14.36 g and the hydrothermal time was changed to 6 hours.

Example 9
A hafnia thin film I was obtained in the same manner as in Example 6 except that the amount of formic acid in Example 6 was changed to 4.79 g and the hydrothermal time was changed to 6 hours.

(Example 10)
A hafnia thin film J was obtained in the same manner as in Example 6 except that the amount of formic acid in Example 6 was changed to 14.36 g and the hydrothermal time was changed to 15 hours.

(Comparative Example 1)
5.48 g (0.017 mol) of zirconium chloride octahydrate (ZrOCl ₂ .8H ₂ O) was dissolved in 32.0 g of H ₂ O. To this solution, 3.5 mL of 29% aqueous ammonia was slowly added to obtain a white precipitate (zirconium hydroxide). The white precipitate was suction filtered and washed with H ₂ O until pH 7 or lower. After adding 20.0 g of H ₂ O to the washed white precipitate, 24.0 g of 98% formic acid (HCOOH) was added with stirring. Subsequently, H ₂ O was added so that the total amount of the zirconia sol became 80.0 g, and the mixture was heated and stirred at 80 ± 3 ° C. for 3 hours, and then cooled to obtain a zirconia sol. This zirconia sol is a sol produced by a sol-gel method.

The obtained zirconia sol was applied onto a glass substrate in the same manner as in Example 1 and irradiated with ultraviolet rays to obtain a zirconia thin film (Comparative A).
On the other hand, a zirconia gel was obtained by removing the solvent from a part of the zirconia sol obtained by the sol-gel method, FT-IR spectrum measurement was performed on the zirconia gel, and the obtained FT-IR spectrum is shown in FIG. It was.

(Comparative Example 2)
Hafnium chloride (HfCl ₄ ) 5.44 g (0.017 mol) was dissolved in 30.0 g of H ₂ O. To this solution, 9 mL of 29% aqueous ammonia was slowly added to obtain a white precipitate (hafnium hydroxide). The white precipitate was suction filtered and washed with H ₂ O until pH 7 or lower. After adding 30.0 g of H ₂ O to the washed white precipitate, 24.0 g of 98% formic acid (HCOOH) was added with stirring. Subsequently, H ₂ O was added so that the total amount of the hafnia sol became 80.0 g, and the mixture was heated and stirred at 80 ± 3 ° C. for 3 hours and then cooled to obtain a hafnia sol.

  The obtained hafnia sol was applied onto a glass substrate in the same manner as in Example 1 and irradiated with ultraviolet rays to obtain a hafnia thin film (Comparative B).

(Comparative Example 3)
Zirconium chloride oxide octahydrate (ZrOC1 ₂ · 8H ₂ O) 5.48 g (0.017 mol) was dissolved in 32.0 g of H ₂ O. To this solution, 35 mL of 29% aqueous ammonia was slowly added to obtain a white precipitate (zirconium hydroxide). The white precipitate was suction filtered and washed with H ₂ O until pH 7 or lower. After adding 20.0 g of H ₂ O to the washed white precipitate, 2.5 g of 35% HCl was added with stirring. Subsequently, H ₂ O was added so that the total amount of zirconia sol became 80.Og, and this was put in a Teflon inner cylinder, and further put in an autoclave and sealed. This was heated at 120 ° C. for 4 hours to be hydrothermally synthesized and cooled to obtain a hydrothermal zirconia sol.
This zirconia sol was applied onto an alkali-free glass that had been washed under high humidity (99% humidity) under a coating condition of 500 rpm / 15 sec → 2000 rpm / 30 sec using a spinner (K-3959D-1, Kyowa Riken). The coating could not be made uniform, resulting in a zirconia gel film with severe coating unevenness.
This zirconia gel film was irradiated with ultraviolet rays for 1, 5 and 10 minutes using a high pressure mercury lamp (HlOOOL, Toshiba Lighting & Technology) to obtain a zirconia thin film (Comparative C).
(Comparative Example 4)
In Comparative Example 3, after adding 20.0 g of H ₂ O to the washed white precipitate, hydrothermal synthesis was performed by adding only H ₂ O to a total amount of 80.0 g to obtain a reaction liquid containing white powder. It was.
This reaction solution was applied onto alkali-free glass that had been washed under high humidity (99% humidity) under a coating condition of 500 rpm / 15 sec → 2000 rpm / 30 sec using a spinner (K-3959D-1, Kyowa Riken). The reaction solution was bounced from the glass substrate and could not be applied.
(Comparative Example 5)
A hafnia thin film (Comparative D) with severe coating unevenness was obtained in the same manner as Comparative Example 3 except that 5.44 g of hafnium chloride was used instead of the zirconium chloride octahydrate of Comparative Example 3.
(Comparative Example 6)
In Comparative Example 4, the same procedure as in Comparative Example 4 was conducted except that 5.44 g of hafnium chloride was used instead of zirconium chloride octahydrate. After hydrothermal synthesis, a reaction liquid containing white powder was obtained, and when this was applied onto an alkali-free glass substrate by the spinner method, the reaction liquid was repelled from the glass substrate and could not be applied.
<Measurement of pencil hardness>
The pencil hardness of the prepared thin film sample was measured based on the pencil hardness test JIS K 5600-5-4 using a pencil scratch coating film hardness tester P-TYPE (Toyo Seiki Seisakusho). The method of measurement is to press the pencil hardness test pencil of 6B-9H against the composite film at an angle of 45 degrees and the load of 750g, scan the line of 7mm or more with three lines, and film with the naked eye The surface was inspected, and the test was repeated with increasing hardness until at least two scars of 3 mm or more were generated. The hardest pencil hardness at which no scar was generated was defined as the pencil hardness of the composite film.

<Appearance inspection of sol>
The appearance of the produced zirconia sol and hafnia sol was visually inspected.

  The appearance of the sol and the pencil hardness of the sample are summarized in Table 1.

註：＊は「塗布ムラが激しいので測定できなかった。」ことを意味する。

註: * means “Measurement was not possible because of uneven application”.

  The hard film according to the present invention can be used as a protective film for protecting the surfaces of lenses, prisms and the like in optical devices such as plastic covers for watches, display screens for mobile phones, synthetic resin products, binoculars and telescopes, for example. .

Claims (10)

  The hafnium compound and / or zirconium compound is converted into hafnium hydroxide and / or zirconium hydroxide with aqueous ammonia in the absence of a particle growth regulator, and the resulting aqueous liquid containing hafnium hydroxide and / or zirconium hydroxide is aged. The aqueous liquid is obtained by hydrothermal treatment in the presence of an excess amount of organic acid relative to 1 mol of hafnia and / or zirconia, and contains an organic acid and contains amorphous hafnia and / or amorphous zirconia. A hafnia sol and / or a zirconia sol characterized by comprising:   The hafnia sol and / or zirconia sol according to claim 1, wherein the hafnium compound is a hafnium alkoxide or a hafnium salt, and the zirconium compound is a zirconium alkoxide or a zirconium salt.   The hafnia sol and / or zirconia sol according to claim 1 or 2, wherein the organic acid is formic acid or acetic acid, and the hydrothermal treatment has a heating temperature of 80 to 140 ° C. The Hafuniazoru and / or zirconia sol, Hafuniazoru and / or according to any one of the claims 1 to 3 having absorption in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 at FT-IR spectrum of the gel Zirconia sol.   The hafnium compound and / or zirconium compound is converted into hafnium hydroxide and / or zirconium hydroxide with aqueous ammonia in the absence of a particle growth regulator, and the resulting aqueous liquid containing hafnium hydroxide and / or zirconium hydroxide is aged. And a method for producing a hafnia sol and / or zirconia sol, wherein the aqueous liquid is hydrothermally treated in the presence of an excess of an organic acid with respect to 1 mol of hafnia and / or zirconia.   The method for producing a hafnia sol and / or zirconia sol according to claim 5, wherein the hafnium compound is a hafnium alkoxide or a hafnium salt, and the zirconium compound is a zirconium alkoxide or a zirconium salt.   The method for producing a hafnia sol and / or zirconia sol according to claim 5, wherein the organic acid is formic acid or acetic acid, and the hydrothermal treatment is performed at a heating temperature of 80 to 140 ° C. The Hafuniazoru and / or zirconia sol, Hafuniazoru and / or according to any one of the claims 5-7 having absorption in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 at FT-IR spectrum of the gel A method for producing a zirconia sol.   A cured film obtained by curing a coating film formed by applying the hafnia sol and / or zirconia sol according to any one of claims 1 to 4 on a substrate by ultraviolet irradiation and / or heating. . The Hafuniazoru and / or zirconia sol, cured film according to claim 9 having absorption in 1013 ± 15cm ^-1 and 878 ± 15cm ^-1 at FT-IR spectrum of the gel.

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