JP2011104555A - Hydrophilic coating composition, method for preparing hydrophilic coating composition, hydrophilic coated film layer and building material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrophilic coating composition in which a hydrophilic coated film layer has hydrophilicity without mostly decomposing an organic system substrate by the formed hydrophilic coated film when the surface of the organic system substrate is coated with one layer. <P>SOLUTION: In the hydrophilic coating composition coated on the surface of the organic system substrate which contains crystalline titanium oxide particles and amorphous titanium oxide particles, vanadium is contained in each of the crystal particles and the amorphous particles. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydrophilic coating composition containing functional particles that exhibit hydrophilic ability by light irradiation and a binder, a method for producing the hydrophilic coating composition, and further to the substrate surface by the hydrophilic coating composition. The present invention relates to a formed hydrophilic coating layer and a building material using the substrate. Further, the present invention relates to a technique for imparting long-term antifouling performance to the substrate by enhancing the hydrophilicity and hydrophilicity of the substrate by the hydrophilic coating layer.

  As shown in FIG. 3, crystalline titanium oxide or the like is excited when irradiated with ultraviolet light having energy higher than the band cap to generate electrons and holes, which act on water molecules to generate OH radicals. The resulting organic matter is decomposed. Therefore, studies on antifouling and purification have been made from various angles regarding titanium oxide and the like. Concerning antifouling, a film containing titanium oxide is formed by a sol-gel method, a solid phase reaction, a gas phase reaction, or the like to prevent fouling of building materials or cars.

  Examples of paints used for forming a coating film containing crystalline titanium oxide include titanium oxide powder slurry, a sol prepared by hydrolysis of a salt aqueous solution of titanium oxide and titanium alkoxide, and an amorphous amorphous state of titanium. There are a titanium oxide sol solution in which crystalline titanium oxide particles are present, a metal sol solution in which crystalline titanium oxide is present as particles, and the like.

  In the process of producing these paints, the crystalline titanium oxide particles are doped with other metals. By this dope, the band cap energy of titanium oxide is displaced, so that titanium oxide is excited even in the wavelength range of visible light, and exhibits hydrophilicity and organic matter resolution. However, since holes and electrons are likely to collect in the doped metal, there is an aspect in which the activity of decomposing organic substances cannot be maintained because the holes and electrons are bonded together and disappear.

  Titanium oxide has a high photocatalytic activity among metal oxides, and anatase type, brucite type and rutile type are known as its crystal phase, and the stable crystal phase produced at the lowest temperature is the anatase type.

For example, Non-Patent Document 1 discloses a method for producing titanium oxide particles doped with vanadium or niobium (amorphous titanium oxide particles, crystalline titanium oxide ultrafine particles). In this production method, a hydrothermal reaction is caused by adding ammonia water and hydrogen peroxide to an aqueous solution of titanium tetrachloride containing vanadium (V) or niobium (Nb), and peroxotitanic acid containing vanadium or niobium (HO- _{(NbO 5) n - (TiO} 5) m -OH, m> n or _{HO- (VO 5) p - (} TiO 5) q -OH), to form a non-crystalline molecules q> p), further The technical content of forming ultrafine particles of crystalline titanium oxide having a diameter of several nanometers doped with vanadium or niobium by refluxing this aqueous solution of a complex metal acid in the peroxo state at 100 ° C. for 8 hours is disclosed. .

  On the other hand, Patent Document 1 shows an example in which a coating film is formed with a coating agent containing titanium oxide in forming a coating film and imparting antifouling performance to an organic polymer resin. A first layer is provided on an organic polymer resin using a binder in which a conductive titanium oxide particle is dispersed in an aqueous solvent, and the first layer mainly contains crystalline titanium oxide having photocatalytic activity. An example in which two layers are provided is shown. Thus, even when the second layer is irradiated and the organic matter resolution is exhibited, the organic polymer resin is protected and decomposed by the first layer interposed between the second layer and the organic polymer resin. There is nothing to do.

  However, the former doping of Non-Patent Document 1 is performed for the purpose of making it possible to excite crystalline titanium oxide particles even in the visible light region, and to improve organic matter resolution and hydrophilicity. Crystalline titanium oxide particles are merely an intermediate product for producing the crystalline titanium oxide particles.

  On the other hand, in the latter Patent Document 1, the first layer is interposed between the organic polymer resin and the second layer, and the amorphous titanium oxide particles in the binder contained in the first layer are: With the passage of time, partial crystallization occurs and the organic substance has a resolution, and there is a possibility that the organic polymer resin that is the base of the first layer may be decomposed.

  Furthermore, since the first layer containing the amorphous titanium oxide particles is a thin film for reasons such as low cost, it is difficult to apply uniformly, and the coating film is transparent. It is very troublesome and time consuming to find and repair parts that could not be applied.

  Since the thing of patent document 1 provides two layers, compared with the case where only one layer is provided, since cost and time are required and the process of providing each layer is different, at least two working spaces are provided. There is also a problem that it must be secured.

Japanese Patent Laid-Open No. 9-262481

2. Hiromichi Ichinose, “Improvement of Titanium Oxide Coating Agent and Application to Environmental Purification” [online] Research report 85-89 2002 research report, Saga Prefectural Ceramics Technology Center, [Search September 3, 2009], Internet <URL: http://www.scrl.gr.jp/research/reports/h14/h14titancoat. pdf>

  As a result of intensive studies, the inventors of the present invention contain vanadium in crystalline titanium oxide particles having organic matter resolution and amorphous titanium oxide particles as a component of a binder that gradually increases the organic matter resolution. As a result, it was found that their organic matter resolution (and consequently organic matter decomposition activity) can be adjusted, and the present invention was completed.

  That is, the hydrophilic coating composition according to the present invention contains crystalline titanium oxide particles (functional particles) and amorphous titanium oxide particles (precursor), and is applied to the surface of an organic base material. In the hydrophilic coating composition, vanadium is contained in each of the crystalline titanium oxide particles and the amorphous titanium oxide particles in a predetermined ratio.

  In addition, vanadium may be contained by a method such as dope, and the crystalline titanium oxide particles and amorphous titanium oxide particles containing vanadium have a specific ratio of titanium and vanadium hydroxides. It may be prepared by adding an oxidizing agent to the aqueous solution containing it and reacting by this addition.

  Furthermore, for the formation of the crystalline titanium oxide particles, a molar amount of vanadium that is 1 to 10 mol% with respect to the molar amount of titanium used to form the particles may be used.

  Similarly, for the formation of the amorphous titanium oxide particles, a molar amount of vanadium that is 1 to 10 mol% with respect to the molar amount of titanium used for the formation of the particles may be used.

  In the method for preparing the hydrophilic coating composition according to the present invention, an oxidizing agent is added to an aqueous solution containing the respective hydroxides of titanium and vanadium in a predetermined ratio, and titanium and vanadium are converted into the same molecule by a reaction caused by the addition. A step of forming the amorphous titanium oxide particles contained therein, and a step of forming the crystalline titanium oxide particles by heating a solution of the amorphous titanium oxide particles at a predetermined temperature for a predetermined time. It is characterized by being.

  The coating film according to the present invention is a coating film (hydrophilic coating layer) formed using the above hydrophilic coating composition, and the building material according to the present invention has this hydrophilic coating layer.

  The “Photocatalyst Product Technical Council Rules, Regulations and Test Methods June 2005” defines voluntary standards for quality and safety of photoexcited catalyst products. The crystalline titanium oxide particles according to the present invention As described later, the amorphous titanium oxide particles are not classified as photocatalysts because methylene blue does not completely fade in the activity test (liquid phase film adhesion method) described in this document. .

  According to the present invention, since the crystalline titanium oxide particles contain vanadium which suppresses organic matter resolution at a predetermined ratio, the organic matter resolution of the crystalline titanium oxide particles can be suppressed by vanadium.

  The amorphous titanium oxide particles gradually crystallize (partially crystallize) over time under a predetermined condition (for example, a temperature condition where the solution temperature is 40 ° C. or a natural exposure condition). For this reason, such crystallization has an unnecessary organic matter resolution as a binder.

  However, since the non-crystalline titanium oxide particles contain vanadium at a predetermined ratio as described above, this unnecessary expression of organic matter can be suppressed.

  For the reasons described above, even if the hydrophilic coating composition is applied to the surface of the organic base material and further coated, the organic base material is hardly decomposed. For this reason, it is not necessary to protect the organic base material from unnecessary decomposition of the titanium oxide layer by interposing an inorganic binder layer between the surface of the organic base material and the titanium oxide layer as in the prior art.

  Furthermore, since only one layer of coating is required, it is possible to omit the cost (material cost and labor cost) for coating the binder layer, shorten the manufacturing time of the building material, and omit the work space for coating the binder layer.

  The vanadium is contained in the crystalline titanium oxide particles because the vanadium is used in a molar amount of 1 to 10 mol% with respect to the molar amount of titanium used for forming the crystalline titanium oxide particles. The suppression can be adjusted within an appropriate range without impairing the transparency of the hydrophilic coating composition and the hydrophilic coating layer.

  Since vanadium is used in a molar amount of 1 to 10 mol% with respect to the molar amount of titanium used for forming the amorphous titanium oxide particles, and vanadium is contained in the amorphous titanium oxide particles. The suppression can be adjusted within an appropriate range without impairing the transparency of the hydrophilic coating composition and thus the hydrophilic coating layer.

  If the molar amount of vanadium to be used exceeds 10 mol%, it is not preferable because a color that is visible to the hydrophilic coating layer is obtained.

  Since the vanadium is contained in each of the crystalline titanium oxide particles and the amorphous titanium oxide, the vanadium is uniformly dispersed in each of them, and thereby, near a place where electrons and holes are generated. These recombination centers are scattered, and it becomes easier to adjust the suppression of organic matter resolution.

  In addition, the hydrophilic coating layer can be adjusted to a desired organic matter resolution by adjusting the vanadium content.

  In the method for preparing the hydrophilic coating composition according to the present invention, an oxidizing agent is added to an aqueous solution containing the respective hydroxides of titanium and vanadium in a predetermined ratio, and titanium and vanadium are converted into the same molecule by a reaction caused by the addition. A step of forming the amorphous titanium oxide particles contained therein, and a step of forming the crystalline titanium oxide particles by heating a solution of the amorphous titanium oxide at a predetermined temperature for a predetermined time. Therefore, vanadium is included in the crystalline titanium oxide particles and the amorphous titanium oxide in an aqueous phase.

  Since vanadium is contained in the aqueous phase, the amorphous titanium oxide particles are formed without the formation of oxygen-deficient sites inside the titanium oxide unlike the vapor phase methods such as sputtering and combustion. In addition, the vanadium can be uniformly contained.

  Moreover, the building material which has the effect of organic substance resolution suppression mentioned above is obtained by setting it as the building material which has a hydrophilic coating-film layer.

  For example, in an organic building material having a layer containing titanium oxide as a part of the exterior, the building material is eroded by organic matter decomposition by titanium oxide, so that the building material is shortened in life, but the building material according to the present invention Then, even in the case of a building material having a layer containing titanium oxide in the same amount as above, the vanadium contained in this layer (hydrophilic coating layer) can provide hydrophilicity and organic matter resolution (self-cleaning ability) as antifouling performance. ) Is somewhat sacrificed, but the building materials will not be shortened as described above.

It is the figure which showed process 1, 2 of the preparation method of the coating agent which concerns on embodiment of this invention in process order. It is the figure which showed process 3-5 of the preparation method of the coating agent which concerns on embodiment of this invention in process order. It is the figure shown to process 6 and 7 of the preparation method of the coating agent which concerns on embodiment of this invention. (A) It is explanatory drawing which shows the motion of an electron and a hole when not containing vanadium (V). (B) It is explanatory drawing which shows the motion of an electron and a hole at the time of containing vanadium (V). It is the figure which showed the band cap energy, hydrophilic ability, and organic substance resolution | decomposability of each metal oxide. It is the table | surface which showed the organic substance resolution | decomposability of the hydrophilic coating film layer formed using the amorphous solution (with and without vanadium) immersed in 40 degreeC warm water for a predetermined period. The line graph of the table | surface of FIG. 4 is shown. It is the table | surface which showed the hydrophilic ability of the hydrophilic coating film layer formed using the amorphous solution (with and without vanadium) immersed in 40 degreeC warm water for a predetermined period. The line graph of the table | surface of FIG. 6 is shown. It is the table | surface which showed the organic substance resolution | decomposability of the hydrophilic coating film formed by changing the solid content ratio of anatase solution (ANA) / amorphous solution (AMO) in each of the case where vanadium is contained and not. The line graph of the table | surface of FIG. 8 is shown. It is the table | surface which showed the hydrophilic ability of the hydrophilic coating film layer formed by changing the solid content ratio of anatase solution (ANA) / amorphous solution (AMO) in each of the case where it does not contain vanadium. The line graph of FIG. 10 is shown. It is the table | surface which showed the influence which the molar amount (mol%) of vanadium used for formation of each particle | grain of anatase particle | grains and an amorphous particle | grain has on the color of a hydrophilic coating film layer.

  The coating agent (hydrophilic coating composition) according to the present invention comprises crystalline titanium oxide particles (hereinafter referred to as anatase particles) having organic substance resolution, and non-binding components that gradually increase the organic substance resolution under predetermined conditions. Vanadium is contained in the crystalline titanium oxide particles (hereinafter referred to as amorphous particles) by a method such as doping.

  The anatase particles and the amorphous particles are contained as solid contents in the anatase solution and the amorphous solution, respectively. The solid content ratio of the anatase solution / amorphous solution is 90:10 to 10:90, preferably 75:25 to 25:75, and is contained in the coating agent.

  When the solid content ratio of the anatase solution exceeds 90, the proportion of amorphous particles in the composition of the coating agent decreases, the adhesion of the formed hydrophilic coating layer to the organic base material decreases, and hydrophilicity It is not preferable because the coating layer is easily peeled off.

  Vanadium is desirably contained in the amorphous particles in a molar amount of 1 to 10 mol% with respect to the molar amount of titanium used for forming the amorphous particles. If the molar amount of vanadium is less than 1 mol%, the effect of suppressing the organic matter resolution is low, and if it is higher than 10 mol%, the brown color increases as described later, and the transparency of the hydrophilic coating layer is lost. End up.

  As the vanadium source, vanadium compounds such as vanadium chloride, vanadium hydroxide, vanadium sulfide, and vanadium iodide can be used.

  Similarly, it is desirable to contain vanadium in the anatase particles in a molar amount of 1 to 10 mol% with respect to the molar amount of titanium used for the formation of the anatase particles. When the molar amount of vanadium is less than 1 mol%, the effect of suppressing the organic matter resolution of the anatase particles is low, and when it is higher than 10 mol%, the brown color of the hydrophilic coating layer increases, and the transparency is similarly lost. End up.

  When the vanadium is contained in each particle, the method is basically in accordance with the manufacturing method described in “Hiromichi Ichinose,“ Improvement of Titanium Oxide Coating Agent and Application to Environmental Purification ”(Non-Patent Document 1). According to this document, the average particle diameter of anatase particles contained in this sol is estimated to be in the following range of 40 nm. The specific procedure is based on [Step 1] to [Step 7] described later.

  Examples of the organic base material that can be used for the hydrophilic coating layer according to the present invention include those that can be used for building materials, and include base materials containing organic polymer polymers. For example, organic polymers such as acrylic silicon, acrylic urethane, polyolefin, polyether, and fluorine can be used.

  As this organic base material, if it is hydrophilic to such an extent that formation of striped droplets on the surface of the base material is prevented when a coating agent is applied, it is preferable because it can be applied more uniformly. Any material that can be applied uniformly can be used. In the case of an inorganic base material, any base material may be used without any particular limitation.

  If a surfactant is added to the coating agent, the surface tension is lowered, so that the coating agent is less likely to be repelled on the surface of the organic base material during application, and the coating agent can be applied evenly and uniformly.

  The surfactant may be a water-soluble solvent, and anionic, cationic ionic molecules, nonionic nonionic molecules, and the like can be used. For example, monoalcohols such as methanol, ethanol and propanol and dialcohols such as ethylene glycol, propylene glycol and propylene glycol can be used. Also, cellosolves such as methyl cellosolve, cellosolve, and butyl cellosolve can be used.

  In addition, since the coating agent is almost an inorganic component, a coating agent may be added to the coating agent in order to enhance the adhesion of the formed hydrophilic coating layer to the substrate when applied to an organic substrate. Good. As this coupling agent, for example, a silane coupling agent, a titanium coupling agent, or an aluminum coupling agent can be used. The formed almost inorganic hydrophilic coating layer is more firmly bonded to the surface of the organic base material by this coupling agent.

  Further, a matting agent may be added to the coating agent in order to erase the gloss of the hydrophilic coating layer and improve the appearance. As the matting agent, extender pigments and clays such as kaolin, talc, alumina, hydrotalcite, benton, barium sulfate and calcium carbonate can be used.

  In the preparation method for preparing the coating agent according to the present invention, an oxidizing agent such as hydrogen peroxide is added to an aqueous solution containing titanium hydroxide and vanadium hydroxide at a predetermined ratio, and the titanium is formed by a reaction caused by the addition. And the vanadium in the same molecule are formed, and anatase particles are formed from the amorphous particles.

Hereinafter, the preparation method of the hydrophilic coating composition and the formation of the hydrophilic coating layer will be described with reference to FIGS. In addition, the specific numerical value in description is an illustration and is not restricted to these.
[Step 1]: Preparation of raw materials A titanium source, a vanadium source, etc. are prepared as raw materials to be used in Step 2 and subsequent steps.

  First, the volume of the amorphous solution or anatase solution to be finally prepared is determined, and the final concentration of titanium (for example, 0.5% by weight) and the molar amount of titanium (for example, 0.1 mol) contained in the solution are determined. A titanium chloride aqueous solution containing a molar amount of titanium is prepared as a titanium source. When preparing an amorphous solution and when preparing an anatase solution, it is easier to prepare the coating agent later when the molar amount of titanium is the same.

  Further, for example, vanadium oxide (0.0005 to 0.005 mol) containing a molar amount of vanadium (0.001 to 0.01 mol in the above example) that is 1 to 10 mol% with respect to the molar amount of titanium described above is prepared.

  Also, ammonia water for neutralization and ammonia water for vanadium solution preparation are prepared. The molar amount of ammonia in the ammonia water for preparing the vanadium solution is not more than the molar amount of ammonia finally used for neutralization, and an arbitrary molar amount is added to set the starting pH at the time of pH adjustment. be able to.

  As shown in FIG. 1A, a compound containing vanadium (in the above example, vanadium oxide) is dissolved in ammonia water for preparing a vanadium solution, and appropriately diluted with distilled water (in the above example, the vanadium oxide concentration is set to 0.1%). 9% by weight) to obtain a vanadium solution.

Moreover, since it is very acidic, you may mix the titanium chloride aqueous solution and distilled water about twice the weight of the titanium chloride contained in this.
[Step 2]: Precipitation In step 2, the solutions prepared in step 1 are mixed to form a precipitate (gel).

  First, a vanadium solution and neutralizing ammonia water are mixed, and the total amount of this solution is gradually added to the titanium chloride aqueous solution. Thereafter, the pH is further adjusted with aqueous ammonia, but it is preferably adjusted to pH 3-5 when preparing highly viscous amorphous particles, and pH 7 when preparing anatase particles.

  Thereby, a precipitate (gel) in which titanium hydroxide and vanadium hydroxide are mixed is obtained (see step 2 in FIG. 1).

Here, when mixing the vanadium solution and ammonia water, the amount of vanadium to be contained can be adjusted by adjusting the amount of the vanadium oxide solution to be mixed.
[Process 3]: Removal of unnecessary ions (cleaning)
Next, in step 3, as shown in FIG. 1B, distilled water is added to the precipitate (gel) of step 2 and washed with water, and the supernatant is removed. This washing with water is repeated until the conductivity of the supernatant liquid becomes 10 μs / cm at which chloride ions and ammonium ions are not more than a predetermined concentration. This is because, in a state where ammonium ions remain at a certain concentration or more (0.014 mol / l or more in Non-Patent Document 1), crystallization is difficult to proceed when the subsequent step 5 is performed. After washing with water, the amount of water required to reach the final solution concentration (0.5% in the example) is added to the weight of the precipitate (gel) (not shown).
[Step 4]: Gel dissolution (Preparation of amorphous solution)
Next, in step 4, an oxidant such as hydrogen peroxide is added to the precipitate (gel) washed in step 3 and dissolved to obtain an amorphous solution.

  First, an oxidant such as hydrogen peroxide is added to a precipitate (gel) obtained by discarding the supernatant water from Step 3 and added to water in a molar amount 10 times the molar amount of titanium.

  Thus, an amorphous solution (in the above example, an amorphous solution containing 0.1 mol of titanium and 0.001 to 0.01 mol of vanadium) is obtained.

  Here, when preparing the amorphous solution, it is preferable that the preparation conditions are different between the case where the amorphous solution used for the binder is prepared and the case where the amorphous solution for forming the anatase particles is prepared.

  Specifically, in the case of preparing an amorphous solution for the binder, the temperature of the mixture of the precipitate (gel) and distilled water in step 3 is adjusted from room temperature to, for example, around 40 ° C., and this temperature is maintained in a thermostatic bath or the like. While adding an oxidizing agent such as hydrogen peroxide. After that, the precipitate (gel) is melted and stirred until it becomes an orange to yellow transparent solution, taken out of the thermostatic bath and left at room temperature to obtain a jelly-like high-viscosity amorphous solution suitable for a binder. It is done.

On the other hand, in the case of preparing an amorphous solution for anatase particles, the temperature of the mixture of the precipitate (gel) and distilled water in step 3 is adjusted to a low temperature, for example, around 5 ° C., and this temperature is maintained in a constant temperature bath or the like. Add an oxidizing agent such as hydrogen peroxide. After that, the precipitate (gel) is melted and stirred until it becomes a transparent solution exhibiting orange to yellow, taken out from the thermostatic bath and left at room temperature, so that it is low viscosity like water and suitable for the formation of anatase particles A solution is obtained.
[Step 5]: Crystallization Next, the amorphous solution for anatase particles prepared in Step 4 is further maintained at a temperature of, for example, about 100 ° C. and refluxed for 1 hour (h) to 70 hours (h). Is obtained by crystallizing anatase particles containing vanadium (in the above example, anatase particles estimated to contain 1 to 10 mol% of vanadium with respect to the amount of titanium in the particles). .

As another method for obtaining anatase particles containing vanadium, an amorphous solution containing no vanadium is prepared through steps 1 to 4 without using a vanadium solution. Although there is a method of adding vanadium by adding a solution and continuing refluxing, it is preferable to use a vanadium solution from the step 2 from the viewpoint of uniformly containing vanadium.
[Step 6]: Preparation of Coating Agent Next, as shown in FIG. 1C, a coating agent is prepared from an anatase solution, an amorphous solution, water (optionally).

  Since the length of the formed anatase particles and amorphous particles and the molar amount of each particle itself are not known, basically, as described above, the coating agent should be prepared in consideration of the solid content ratio of both the anatase solution and the amorphous solution. Do.

In this case, since the anatase particles are crystallized to have organic matter resolution, when the anatase particles are included, the organic matter resolution is increased as compared with the case where the anatase particles are not included. The total weight percent of each particle relative to the coating agent can be of a general composition and can be arbitrarily changed. The remaining composition is water or the additive as described above.
[Step 7]: Coating The hydrophilic coating film layer according to the present invention is a coating film formed using the coating agent, and preferably has a thickness of less than 20 μm. A thick coating of 20 μm or more is not preferable because it lacks transparency and becomes conspicuous when cracks occur.

  Moreover, it can be applied as thin as possible. The range that can be thinly coated depends on the hydrophilicity of the organic base material or inorganic base material on which the hydrophilic coating layer is formed, and varies depending on the material of the organic base material or inorganic base material. Organic base materials or inorganic base materials that are highly hydrophilic and easy to coat are preferred.

As a method for applying the coating agent to the organic base material or the inorganic base material, it can be performed by a method such as spray coating, dipping, spin coating, brush coating, bell coating or the like.
(Drying the coating)
Regarding drying of the hydrophilic coating layer after coating, any drying method that does not adversely affect the coating film or the organic base material, such as a temperature range in which the base material is not altered in the case of an organic base material, can be used. You may dry by a method.

EXAMPLES Examples and comparative examples of the present invention will be shown below, and the present invention will be described in more detail. However, the present invention is not limited to these examples and the like. 4 to 7, the vanadium mixing amount (mol%) indicates the molar amount (mol%) of vanadium used with respect to the molar amount of titanium used for forming the amorphous particles.
[Example 1]
In Example 1, amorphous particles were formed using about 0.1 mol of titanium (Ti) and about 0.001 mol of vanadium (about 1 mol% of the molar amount of titanium). Only the formed amorphous solution was used as a coating agent. Thereafter, a hydrophilic coating layer was formed with the coating agent, and the organic matter resolution and hydrophilic ability were evaluated.

The specific procedure (steps 1 to 7, coating, organic matter resolution and measurement of hydrophilic ability) will be described below.
[Step 1]: Preparation of raw materials The following were prepared.
Liquid A: Titanium chloride aqueous solution (titanium source)
(Wako Pure Chemical Industries, TiTl ₄ aqueous solution, titanium (Ti) 16.5 ± 0.5 wt%)
B liquid: Ammonia water (ammonia source)
(Wako Pure Chemical Industries, NH ₄ OH aqueous solution, ammonia (NH ₃ ) containing 25-27.9 ± 0.5 wt%)
C liquid: Vanadium solution (Vanadium source)
(Vanadium oxide containing 95% or more by weight)
Liquid D: Hydrogen peroxide solution (hydrogen peroxide source)
(Wako Pure Chemical Industries, hydrogen peroxide solution, 30.0-35.5 wt%)
Liquid E: Vanadium solution (vanadium oxide about 0.9% by weight)
For solution E, vanadium solution (manufactured by Wako Pure Chemical Industries, containing 95 wt% or more as V ₂ O ₅ ) 3.6 g (about 0.02 mol as vanadium) and solution B ammonia water (Wako Pure Chemicals NH ₄ OH) solution was prepared as a mixture of about 0.02 mol) and distilled water 378.4g as 25 to 27.9 wt% content) 18.0 g (ammonium ion as NH ₃ containing vanadium oxide about 0.9 wt%.
[Step 2]: Formation of Precipitate (Gel) 30 g of titanium chloride solution (solution A) (about 0.1 mol as titanium) and 60 g of distilled water were mixed in a 3 L beaker. Separately from this, aqueous ammonia (liquid B) was diluted with distilled water (about 140 g) to 2.5 wt%. Diluted aqueous ammonia (about 0.074 mol) was mixed with about 10.54 g (about 0.001 mol) of vanadium solution (solution E). The total amount of this solution was mixed with a 3 L beaker solution.

Further, pH was measured with a pH meter (HANNAHI 98129COMBO1) every time 20 g of ammonia water (liquid B) was added to a 3 L beaker. The pH was adjusted to 4 to form a precipitate (gel) for amorphous particles. Furthermore, after passing through the same procedure as described above, a precipitate (gel) was similarly formed at pH 7 for anatase particles.
[Step 3]: Removal of unnecessary ions (cleaning)
Distilled water is added to each of the solutions containing precipitates at the end of step 2 (about 400 g each) to make 3 L, and the conductivity of the supernatant at this time is measured with a pH meter (HANNAHI 98129COMBO1 or Horiba B-173). Was removed. These operations were repeated until the conductivity of the supernatant of each solution became 10 μS / cm or less.
[Step 4]: Preparation of Amorphous Solution The supernatant of each solution in Step 3 was discarded, the weight of the precipitate (gel) was measured, and about 118 g (about 1 mol) of hydrogen peroxide solution (D solution) was prepared. Further, distilled water was added to the precipitate (gel) in consideration of the weight of the precipitate (gel) and the weight of hydrogen peroxide so that the titanium weight concentration was 0.5%.

  For preparation of an amorphous solution for amorphous particles (binder), this solution was subjected to hot water bathing at about 40 ° C. in a thermostatic bath, and when the liquid temperature reached about 40 ° C., hydrogen peroxide solution (D solution ) About 118 g (about 1 mol) was added to the solution to make about 1 L of a solution having a titanium concentration of about 0.5% by weight.

Then, it stirred until it became an orange-yellow transparent solution, took out from the thermostat, and left at normal temperature, and obtained the jelly-like high viscosity amorphous solution.
[Step 5]: Crystallization In order to examine whether the amorphous particles crystallize by warm water immersion at 40 ° C., Step 5 was omitted, and crystallization was not performed.
[Step 6]: Preparation of coating agent In Example 1, as described above, it is examined that amorphous particles are crystallized by immersion in hot water at 40 ° C. Therefore, only an amorphous solution is used as a coating agent, and other additives are used. Etc. were not included.
[Step 7]: Coating After spreading 2 ml of the coating agent on a commercially available slide glass (Matsunami Glass Industry Co., Ltd. S-1111 (length 76 mm × width 26 mm × thickness 0.8-1.0 mm)), spin coating method ( 500 rpm, 5 seconds, 1,500 rpm 10 seconds). The slide glass was dried at room temperature. Coating and drying were repeated twice in total to form a hydrophilic coating layer.
(Organic substance resolution evaluation)
A test piece was prepared by irradiating the hydrophilic coating layer of this slide glass with ultraviolet rays (1.0 mW / cm ² ) for 3 hours, as described in “Photocatalyst Product Technical Regulations, Rules and Test Methods (June 2005)”. The organic matter resolution of the hydrophilic coating layer was evaluated by Photocatalyst Performance Evaluation Test Method I (liquid phase film adhesion method, 2001 version) (see Example 1 in FIGS. 4 and 5).

The values in the table shown in FIG. 4 represent the methylene blue decomposition rate [%] when the methylene blue substrate solution immediately after preparation is blank (decomposition rate 0%).
(Hydrophilicity evaluation)
Five slide glasses with the above coating were prepared, and these were left in a constant temperature and humidity room (dark place) with a humidity of 65% and a temperature of 23 ° C. for 8 hours or more. Thereafter, the slide glass left out of the constant temperature and humidity chamber was taken out. 1 μl of distilled water was dropped onto the hydrophilic coating layer of each slide glass with a micropipette or the like, and the contact angle between the hydrophilic coating layer and water was measured. The average of each measured value was taken and the hydrophilic ability of the hydrophilic coating layer was evaluated.

  In addition, Kyowa Interface Science Co., Ltd. DM300 was used for the measurement of a contact angle. This result was defined as the contact angle of the hydrophilic coating layer in the dark (unirradiated) (see FIG. 6).

On the other hand, another slide glass (same as above) coated in the same manner was prepared, and this hydrophilic coating layer was irradiated with ultraviolet rays (1.0 mW / cm ² ) in the dark for 3 hours. Thereafter, 1 μl of distilled water was dropped onto the hydrophilic coating layer after irradiation with a micropipette or the like, and the contact angle between the hydrophilic coating layer and water was measured. For the measurement of the contact angle, the average of the measured values of each slide glass was taken and evaluated as the hydrophilic ability of the hydrophilic coating layer. For this measurement, Kyowa Interface Science Co., Ltd. DM300 was used as described above. This result was defined as the contact angle of the hydrophilic coating layer after irradiation (see Example 1 in FIG. 6).
[Example 2, Example 3]
When preparing the amorphous solution in Step 4 of Example 1, the solution was heated at 40 ° C. for 27 days (Example 2) and 60 days (Example 3), respectively, from the time when the temperature of the solution became approximately 40 ° C. Except that the temperature was maintained, the coating, organic matter resolution, and hydrophilic ability were evaluated in the same manner as in Example 1 (see FIGS. 4 to 7).
[Example 4]
As in Example 1, except that the amount of the vanadium solution (solution E) mixed in Step 2 of Example 1 was adjusted to about 31.6 g (containing about 0.003 mol of vanadium), coating, organic matter resolution and The hydrophilic ability was evaluated (see FIGS. 4 to 7).
[Examples 5 and 6]
When preparing the amorphous solution in Step 4 of Example 4, the solution was heated at 40 ° C. for 27 days (Example 5) and 60 days (Example 6), respectively, from the time when the temperature of the solution became approximately 40 ° C. Except for maintaining the temperature, the coating, organic matter resolution and hydrophilic ability were evaluated in the same manner as in Example 4 (see FIGS. 4 to 7).
[Example 7]
Coating and organic matter resolution as in Example 1, except that the amount of the vanadium solution (E solution) mixed in Step 2 of Example 1 was adjusted to about 52.7 g (containing about 0.005 mol of vanadium). And hydrophilic ability was evaluated (refer FIGS. 4-7).
[Examples 8 and 9]
When preparing the amorphous solution in Step 4 of Example 7, the solution was heated at 40 ° C. for 27 days (Example 8) and 60 days (Example 9), respectively, from the time when the temperature of the solution became approximately 40 ° C. The coating, organic matter resolution, and hydrophilicity were evaluated in the same manner as in Example 7 except that the temperature was maintained.
[Example 10]
As in Example 1, except that the amount of the vanadium solution (solution E) mixed in Step 2 of Example 1 was adjusted to about 73.8 g (containing about 0.007 mol of vanadium), coating, organic matter resolution and The hydrophilic ability was evaluated.
[Examples 11 and 12]
When preparing the amorphous solution in Step 4 of Example 10, the solution was heated at 40 ° C. for 27 days (Example 11) and 60 days (Example 12), respectively, from the time when the temperature of the solution became approximately 40 ° C. Except that the temperature was maintained, the coating, organic matter resolution and hydrophilic ability were evaluated in the same manner as in Example 10.
[Example 13]
As in Example 1, except that the amount of the vanadium solution (liquid E) mixed in Step 2 of Example 1 was adjusted to about 105.5 g (containing about 0.01 mol of vanadium), coating, organic matter resolution and The hydrophilic ability was evaluated.
[Examples 14 and 15]
When preparing the amorphous solution in Step 4 of Example 13, the solution was heated at 40 ° C. for 27 days (Example 14) and 60 days (Example 15), respectively, from the time when the temperature of the solution became approximately 40 ° C. Except that the temperature was maintained, the coating, organic matter resolution, and hydrophilic ability were evaluated in the same manner as in Example 13.
[Comparative Example 1]
The coating, organic matter resolution and hydrophilic ability were evaluated in the same manner as in Example 1 except that the vanadium solution (E solution) was not added in Step 2 of Example 1.
[Comparative Examples 2 and 3]
When preparing the amorphous solution in Step 4 of Comparative Example 1, the solution was heated at 40 ° C. for 27 days (Comparative Example 2) and 60 days (Comparative Example 3), respectively, from the time when the temperature of the solution became approximately 40 ° C. Except that the temperature was maintained, the coating, organic matter resolution and hydrophilic ability were evaluated in the same manner as in Comparative Example 1 (see FIGS. 4 to 7).
(Hydrophilicity of hydrophilic coating layer and organic matter resolution)
4 and 5, when vanadium is not contained (0 mol%) and the immersion time at 40 ° C. in warm water is 27 days and 60 days, the amorphous particles in the solution cause partial crystallization, and the organic matter resolution is reduced. (Comparative Examples 2 and 3). On the other hand, when the 40 ° C. warm water immersion time was 0 days, the amorphous particles were hardly crystallized, so the organic matter resolution was low (Comparative Example 1).

  On the other hand, 1 mol% of vanadium is included with respect to the molar amount of titanium used for forming the amorphous particles, and when the 40 ° C. hot water immersion time is 27 days and 60 days, the amorphous particles are similarly crystallized. Organic matter resolution was suppressed by the applied vanadium (Examples 2 and 3). In addition, when the 40 ° C. warm water immersion time was 0 days, the amorphous particles were hardly crystallized, and thus the organic matter resolution was low as in Comparative Example 1 (Example 1).

  Similarly, when the molar amount of vanadium to be 3, 5, 7, 10 mol% is contained (Examples 4 to 15), the molar amount to be 1 mol% is contained (Examples 1 to 3). ) Organic matter resolution was suppressed to the same level.

  Even if the amount of vanadium contained is increased from 1 mol%, the effect of suppressing the organic matter resolution is not changed so much and is uniform, and when the amount of vanadium contained is increased, the production cost increases and as described later. Since the hydrophilic coating layer is colored, the amount of vanadium contained is most preferably around 1 mol% from these viewpoints.

  In addition, as described above, even with only 1 mol%, the organic matter resolution of the hydrophilic coating layer was sufficiently suppressed (Examples 1 to 3), and therefore, less than 1 mol%, for example, 1 such as 0.1 mol%. Even when vanadium is contained in an orderly low molar amount, the effect of suppressing the organic matter resolution of the hydrophilic coating layer is lower than in the case of 1 mol%, but it can be suppressed to some extent (not shown).

  Further, regarding the temperature condition, since the amorphous particles crystallize under a temperature condition of 40 ° C., the crystallization rate is further increased at a temperature higher than that, and relatively higher at an immersion temperature higher than 40 ° C. An effect is obtained.

  On the other hand, although the crystallization rate becomes slower at a lower immersion temperature, for example, 20 ° C., crystallization itself occurs, so the period from the preparation of the amorphous solution to the preparation and application of the coating agent (the storage time of the amorphous solution is In the case of a long time) or when a long period of time has passed after coating, the crystallization of the amorphous particles is potentially advanced and the organic base material is gradually decomposed. Therefore, it is effective to contain vanadium.

  About the hydrophilic ability of a hydrophilic coating film layer, as shown in the column after the irradiation of the right of FIG. 6, when vanadium is contained by 1,3,5,7,10 mol% (Examples 1-15) Then, it was almost uniform hydrophilic ability. For this reason, it is particularly preferable to contain vanadium in the vicinity of 1 mol% in consideration of the cost and the like as described above.

  In addition, as shown to the dark place (non-irradiation) column of the left of FIG. 6, in the non-irradiation thing (Comparative Examples 1-3, Examples 1-15), 40 degreeC warm water immersion time (0,27,60 The contact angle was uniform within each day. This indicates that if the 40 ° C. warm water immersion time is the same, the initial value of the contact angle before irradiation is substantially the same regardless of the amount of vanadium contained.

  Moreover, when visually confirmed after forming a hydrophilic coating film layer, peeling of the hydrophilic coating film layer was not seen in both said each Example and a comparative example. Even after being immersed in warm water, the hydrophilic coating layer formed on the surface of the substrate is not peeled off. Even if the amorphous particles are changed into anatase particles after immersion in warm water, the amorphous particles remain above a predetermined ratio. If there is no problem.

  Since amorphous particles adhere to the base material as a binder component, when the amorphous particles not containing vanadium partially crystallize into anatase particles as in the conventional product, the base material deteriorates due to its organic matter resolution. In such a case, since vanadium is contained in each particle, the organic matter resolution is suppressed and the base material is hardly deteriorated. Therefore, even if the amorphous particles are partially crystallized by immersion in warm water, the organic matter decomposition is suppressed, so that the risk of the above-described deterioration problem is reduced.

  As an incidental effect, since the amorphous particles are also in close contact with the anatase particles, the activity of the anatase particles is suppressed by vanadium in the amorphous particles as in the case where vanadium is supported on the surface of the anatase particles.

  Next, in Examples 16 to 19, the solid content ratio (anatase solution: amorphous solution (ANA / AMO)) was changed to form a hydrophilic coating layer with a coating agent containing anatase particles, and the organic matter resolution The hydrophilic ability was evaluated.

In addition, the amount of vanadium contained in each of the following examples was about 5 mol% with respect to the amount of each titanium of the anatase particles and the amorphous particles. For the comparative example, vanadium was not included. Therefore, the vanadium mixing amount shown in FIGS. 8 to 12 (V mixing amount, molar amount of vanadium contained (mol%) with respect to the molar amount of titanium) is not described for each particle, but is collectively expressed as one notation. .
[Example 16]
In Example 16, the solid content ratio of the anatase solution: amorphous solution was about 0: 100, and the molar amount of vanadium used for forming the amorphous particles was 5 mol% with respect to the molar amount of the titanium (this implementation) In the example, the coating agent was prepared as about 0.005 mol).

  Specifically, since this molar amount is substantially the same as in Example 7, steps 1 to 3 are omitted, and the step (Example 1) is performed using the precipitate (gel) at the end of Step 3 in Example 7. Step 4 was performed to prepare an amorphous solution, Step 5 was omitted, and an anatase solution was not prepared. Thereafter, in Step 6, a coating agent was prepared at the above solid content ratio.

  Using this coating agent, the coating, organic matter resolution and hydrophilicity were evaluated in the same manner as in Example 1.

[Example 17]
In Example 17, the solid content ratio of the anatase solution: amorphous solution was about 25:75, and the molar amount of vanadium of the anatase particles and the amorphous particles was 5 mol% with respect to the molar amount of the titanium (this amount) In the examples, it was about 0.005 mol). Since this molar amount is almost the same as in Example 7, Steps 1 to 3 are omitted in the same manner as described above, and each step is performed from Step 4 using the precipitate (gel) at the end of Step 3 in Example 7. It was.

[Step 4]: Preparation of Amorphous Solution The preparation of the amorphous solution for the amorphous particles was the same as in Example 1.
For the preparation of the anatase particles forming anatase particles, the supernatant of the solution in Step 3 of Example 7 was discarded, the weight of the precipitate (gel) was measured, and about 118 g (about 1 mol) of hydrogen peroxide (D solution). Prepared. Further, distilled water was added to the precipitate (gel) in consideration of the weight of the precipitate (gel) and the weight of hydrogen peroxide so that the titanium weight concentration was 0.5%.

This solution was placed in a constant temperature room at 5 ° C., and when the temperature of the solution reached about 5 ° C., about 118 g (about 1 mol) of hydrogen peroxide solution (D solution) was added to the solution to obtain a titanium concentration. Was about 1 L of 0.5 wt% solution. Then, it stirred until it became an orange-yellow transparent solution, took out from the thermostatic chamber, and left at 5 degreeC or normal temperature, and obtained the water-like low-viscosity amorphous solution suitable for anatase particle formation.
[Step 5]: Crystallization A 1-L flask was set in a mantle heater, and the amorphous solution from Step 4 was placed in this flask, and the amorphous solution was refluxed for 1 hour or more by constantly applying the amount of heat that the solution boiled. As a result, the amorphous particles in the amorphous solution were crystallized to form anatase particles. This reflux was performed with a Dimroth cooler.
[Step 6]: Preparation of coating agent The anatase solution in Step 5 and the amorphous solution in Step 4 were mixed so that the solid content ratio was about 25:75.

  Using this coating agent, the coating, organic matter resolution and hydrophilicity were evaluated in the same manner as in Example 1.

[Examples 18 to 20]
In Step 6 of Example 17, the anatase solution and the amorphous solution have a solid content ratio of about 50:50 (Example 18), about 75:25 (Example 19), and about 100: 0 (Example 20). Otherwise, the coating, organic matter resolution and hydrophilicity were evaluated in the same manner as in Example 1.
[Comparative Example 4]
In Comparative Example 4, the solid content ratio of the anatase solution: amorphous solution was about 0: 100, and the coating agent was prepared without using vanadium for forming the amorphous particles.

  Using the precipitate (gel) at the end of Step 3 of Comparative Example 1 that does not contain vanadium, Step 4 of Example 17 was performed to form amorphous particles that did not contain vanadium.

  Step 5 was omitted and no anatase solution was prepared. Thereafter, in Step 6, a coating agent was prepared at the above solid content ratio.

Using this coating agent, the coating, organic matter resolution and hydrophilicity were evaluated in the same manner as in Example 1.
[Comparative Examples 5 to 8]
In Comparative Examples 5 to 8, Steps 4 and 5 of Example 17 were performed using the precipitate (gel) at the end of Step 3 of Comparative Example 1 that did not contain vanadium, and anatase particles that did not contain vanadium. Formed.

Thereafter, in step 6, the solid content ratio of the anatase solution and the amorphous solution was changed to 25:75 (Comparative Example 5), 50:50 (Comparative Example 6), 75:25 (Comparative Example 7), 100: 0 (Comparative Example). 8) Other than that, the coating, the organic matter resolution, and the hydrophilic ability were evaluated in the same manner as in Example 1.
(Influence on organic matter resolution by mixing anatase solution and amorphous solution and changing solid content ratio)
With reference to FIGS. 8 and 9, when vanadium is contained at 5 mol% (Examples 16 to 20), the organic matter of the hydrophilic coating layer is compared with the case where vanadium is not contained (Comparative Examples 4 to 8). The resolution has decreased.

  Furthermore, in the case where the solid content ratio (anatase solution / amorphous solution) is 25/75 to 100/0, the amount of vanadium contained is 0 mol% and 5 mol% regardless of the solid content ratio of the anatase solution. It became substantially uniform organic substance resolution (Examples 17-20, Comparative Examples 5-8).

  That is, in the case of a solid content ratio containing vanadium at 5 mol% and containing anatase particles, the decomposition rate of methylene blue is 40% or less, indicating that organic matter resolution is suppressed regardless of the solid content ratio. (Examples 17 to 20).

  On the other hand, in the case of 0 mol% not containing vanadium, 80% or more of methylene blue was decomposed at any solid content ratio including anatase particles (Comparative Examples 5 to 8).

When vanadium was contained at 5 mol% (Examples 16 to 20), 60% or more of methylene blue remained and coloring of methylene blue was visually recognized. On the other hand, in the case of 0 mol% not containing vanadium (Comparative Example 4) In ˜8), only 10% or less of methylene blue remained, and coloring of methylene blue was not visually recognized. Therefore, Examples 16 to 20 were not photocatalysts, and Comparative Examples 4 to 8 were photocatalysts.
[Examples 21 to 24]
In Examples 21 to 24, the molar amount of vanadium contained was 1 mol% (Example 21), 3 mol% (Example 22), 7 mol% (Example 23), and 10 mol% (Example 24), respectively. The coating agent was prepared in the same manner as in Example 18 except that the anatase solution and the amorphous solution were mixed at a solid content ratio of 50/50.

  In addition, about what contained vanadium 0 mol% and 5 mol%, the coating agent of the comparative example 6 and Example 18 was used, respectively.

These coating agents were each sprayed at 50 g / m ² on a □ 150 mm square cement-type outer wall test piece coated with a white organic paint to form a hydrophilic coating layer having a thickness of about 3 μm.

  These hydrophilic coating layers were measured with a color difference meter. The result is shown in FIG.

  As shown in FIG. 12, when the weight percent of titanium oxide in the coating agent and the film thickness are constant, if the amount of vanadium contained exceeds 10 mol% (Example 24), ΔE, which is a color index. However, it is preferable to contain 10 mol% or less of vanadium.

  As described above, the present invention has been described based on the embodiments, examples, and comparative examples, but the present invention is not limited to the above-described configuration, and for example, it may be contained by another method different from the examples. Specifically, vanadium may be contained on the surface of anatase particles or amorphous particles, or included by inclusion in each particle.

Claims (8)

In the hydrophilic coating composition containing functional particles that exhibit hydrophilic ability by light irradiation and a binder having a precursor of the functional particles,
The functional particles are crystalline titanium oxide particles containing vanadium that suppresses organic matter resolution in a predetermined ratio,
The hydrophilic coating composition, wherein the precursor in the binder is amorphous titanium oxide particles containing vanadium in a predetermined ratio.   The hydrophilic coating composition according to claim 1, wherein vanadium of at least one of the functional particles and the precursor in the binder is contained by doping.   The amorphous titanium oxide is prepared by adding an oxidizing agent to an aqueous solution containing a predetermined ratio of titanium and vanadium hydroxides, and reacting by the addition. Hydrophilic coating composition.   The crystalline titanium oxide particles are formed using vanadium having a molar amount of 1% to 10% with respect to a molar amount of titanium used for forming the titanium oxide particles. 4. The hydrophilic coating composition according to any one of 3 above.   The amorphous titanium oxide particles are formed by using a molar amount of vanadium that is 1% to 10% with respect to a molar amount of titanium used to form the titanium oxide particles. The hydrophilic coating composition of any one of -3. It is a preparation method of the hydrophilic coating composition of any one of Claims 1-5,
Add an oxidizing agent to an aqueous solution containing a predetermined ratio of titanium and vanadium hydroxide,
A step of forming the amorphous titanium oxide particles containing titanium and vanadium in the same molecule by a reaction caused by the addition;
And a step of forming the crystalline titanium oxide particles by heating the amorphous titanium oxide solution at a predetermined temperature for a predetermined time.   A hydrophilic coating layer formed using the hydrophilic coating composition according to any one of claims 1 to 5.   A building material comprising the hydrophilic coating film layer according to claim 7.

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