JP2022041991A - Coated body and coating composition - Google Patents

Abstract

To provide a coated body and a coating composition which are capable of exerting an excellent function of suppressing propagation of molds and/or algae outdoor for a long period of time.SOLUTION: A coated body having a surface layer provided on a base material, in which the surface layer contains photocatalytic titanium oxide particles and cerium oxide particles of a fluorite structure having oxygen deficiency. In the cerium oxide particles, a peak assigned to an F2g oscillation mode of Ce-O bond is deviated to a low wavenumber side by more than 1.0 cm-1 and less than 9.9 cm-1 with respect to a peak assigned to an F2g oscillation mode of the Ce-O bond obtained by measuring a standard substance, in Raman spectral spectrum. The coated body extremely significantly suppresses propagation of molds and/or algae outdoor for a long period of time.SELECTED DRAWING: None

Description

The present invention relates to a coated body and a coating composition. In particular, it relates to a coating body and a coating composition that exert an excellent function of suppressing the growth of mold and / or algae outdoors.

As a coating body that exhibits an antifungal function and an algae-proofing function by being sensitive to light, a coating body containing photocatalytic particles in the surface layer is known.

Conventionally, anatase-type titanium oxide particles have been widely used as photocatalytic particles. In the anatase-type titanium oxide particles, the band gap between the valence band formed by the O (2p) orbital and the conduction electron band formed by Ti (3d) is 3.2 eV, and ultraviolet light of 387 nm or less. Is irradiated to cause a redox reaction based on the transition between bands, whereby the antifungal function and the antialgal function are exhibited.

Further, a photocatalyst in which a photocatalytic reaction is caused by visible light is also known. A typical substance is known as rutile-type titanium oxide. In rutile titanium oxide, the band gap between the valence band formed by the O (2p) orbital and the conduction electron band formed by Ti (3d) is 3.0 eV, so not only ultraviolet rays but also wavelengths. Part of the visible light range of 400-413 nm is also available.

On the other hand, cerium oxide is known as an ultraviolet absorber. Since the band gap between the O (2p) orbital and the Ce (4f0) orbital is 3.1 eV, ultraviolet rays of less than 400 nm are effectively absorbed.

Furthermore, in recent years, research on the photocatalytic properties of cerium oxide has also been conducted, and in the research on oxygen-deficient cerium oxide, it has been reported that the band gap is narrowed and photocatalytic cerium oxide that utilizes light of 500 nm or less by interband transition is reported. (Non-Patent Document 1).

On the other hand, the antifungal effect of cerium oxide is known, and Patent Document 2 states that "one or more selected from water and the poorly water-soluble cerium compound (A) dispersed in the water". A cerium oxide having a particle size of 0.01 μm to 2 μm can be used as the poorly water-soluble cerium compound.

Another description of antifungal and algae-proofing includes a technique using an antibacterial metal that suppresses the growth of microorganisms such as silver and copper (Patent Document 7).

Japanese Unexamined Patent Publication No. 2000-237597 Japanese Unexamined Patent Publication No. 2012-87213 Japanese Unexamined Patent Publication No. 2011-56471 Japanese Unexamined Patent Publication No. 2002-88275 Japanese Unexamined Patent Publication No. 2018-145429 Japanese Unexamined Patent Publication No. 2008-264747 Japanese Unexamined Patent Publication No. 2018-144003

Chem. Cat. Chem., 2018, vol.10, 1267-1271

A coated body containing anatase-type titanium oxide particles in the surface layer often does not have a sufficient amount of ultraviolet rays reaching the surface, such as the outer wall on the north side of a building, and therefore has sufficient outdoor antifungal and algae-proofing functions. It may not be possible to demonstrate it. In order to fully exert the antifungal and anti-algae functions, it is necessary to increase the titanium oxide content or make a thick film in order to increase the photocatalytic activity. The base material deteriorated due to the oxidizing power, peeling of the surface layer and chalking occurred, and in some cases, the weather resistance performance was significantly deteriorated.

In addition, conventionally known photocatalysts of visible ray photoexcitation, such as a coating body containing rutile-type titanium oxide particles in the surface layer, do not have high photocatalytic activity like anatase-type titanium oxide, and thus, in some cases, outdoor protection. It may not be able to fully exert its antifungal function and anti-algae function.

Further, antibacterial metal components such as silver compounds and copper compounds are eluted and disappear when exposed to rainfall, and the antifungal and algae-proofing effects may be lost.

The present inventors can improve the weather resistance performance by mixing titanium oxide particles and cerium oxide particles having specific physical characteristics, and prevent them for a long period of time by an action different from the photocatalytic oxidizing power. It was found that it can exert antifungal and algae-proofing performance. A coating with a surface layer containing photocatalytic titanium oxide particles and certain cerium oxide particles can grow mold and / or algae in an outdoor environment exposed to ultraviolet light and sunlight during the day. We confirmed the fact that it was extremely significantly suppressed.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a coating body and a coating composition capable of exerting an excellent function of suppressing the growth of mold and / or algae outdoors for a long period of time.

That is, the painted body according to the present invention is
A coating body for suppressing the growth of mold and / or algae adhering to the surface.
It has a base material and a surface layer formed on the base material, and the surface layer contains photocatalytic titanium oxide particles and cerium oxide particles having oxygen deficiency in a fluorite structure, and the oxidation thereof. In the cerium particles, in the Raman spectroscopic spectrum, the peak attributed to the F _{2g vibration mode of the Ce—O bond is relative to the peak attributed to the F 2g vibration} mode of the Ce—O bond obtained by measuring the standard substance. , It is more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low wave frequency side. This coating extremely significantly suppresses the growth of mold and / or algae outdoors over a long period of time.

Further, the coating composition according to the present invention is
A coating composition comprising photocatalytic titanium oxide particles and cerium oxide particles having oxygen deficiency in a fluorite structure.
In the cerium oxide particles, in the Raman spectroscopic spectrum, the peak attributed to the F _2g vibration mode of the Ce—O bond becomes the peak assigned to the _F2g vibration mode of the Ce—O bond obtained by measuring the standard substance. On the other hand, it is more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low wavenumber side. A coating body provided with a surface layer obtained by coating the coating composition on a substrate suppresses the growth of mold and / or algae adhering to the surface of the coating body.

Further, according to the present invention, there is provided the use of a coated body according to the present invention for suppressing the growth of mold and / or algae adhering to the surface thereof.

Further provided is the use of the coating composition according to the invention in the manufacture of a coating in which the growth of mold and / or algae adhering to its surface is suppressed.

The mechanism of action for suppressing the growth of mold in the coated body is considered to be unique and completely different from the functions of conventional photocatalysts and fungicides. The expected functions will be described below, but the present invention is not limited thereto.

For example, in the conventional technology using a photocatalyst, when the photocatalyst is allowed to act alone on mold spores, the cell wall and cell membrane are damaged by the action of the active species generated by photocatalytic excitation, and the damage causes the mold spores to die. ..

Further, in the conventional technology of an antifungal agent as a cerium compound, cerium metal ions, which are heavy metals, act on the mold to suppress the growth of the mold. In this case as well, the mold spores are killed as well.

On the other hand, in the coated body of the present invention, the cell wall and cell membrane of mold spores are not damaged by the action. In fact, when the mold spores were transferred to a medium suitable for germination and reproduction after being allowed to act on the coated body of the present invention and cultured, germination and hyphae were elongated and propagated to form colonies. From this fact, it can be concluded that it is highly possible that the coated surface according to the present invention does not have the effect of killing spores. This is because when they die normally, they cannot form colonies. Surprisingly, when observing the growth of mold and algae over a long period of time, it was observed that the coated body of the present invention was less likely to grow mold than the conventional coated body.

In the present invention, after the surface layer is irradiated with light containing ultraviolet rays, as described above, the cell wall and cell membrane of mold spores are hardly damaged, but the ATP value is suppressed to a low level. That is, metabolism is suppressed. It was also observed that the germination of mold spores and hyphal elongation were suppressed.

Upon further detailed evaluation, it was confirmed that cerium oxide, which has many oxygen deficiencies, exerts the specific action of suppressing mold spores, suppressing metabolism, and suppressing germination and hyphal elongation as described above.

Although the surface layer according to the present invention contains a photocatalytic titanium oxide that produces an active species, it does not damage the cell wall or cell membrane of the mold spores and does not kill the mold spores. It is speculated that cerium oxide, which has many oxygen deficiencies, captures and inactivates the active species produced by titanium oxide.

On the other hand, cerium oxide is an insoluble oxide material, but cerium oxide, which has many oxygen deficiencies, dissolves in water in an environment where it is exposed to light including ultraviolet rays and exposed to water such as rainfall. There is a property.

In fact, when ultraviolet rays are applied to a coating body having a surface layer containing both cerium oxide and titanium oxide having many oxygen deficiencies while spraying ion-exchanged water, only cerium oxide in the surface layer is dissolved over time. The phenomenon was confirmed. Moreover, when the coated body was exposed to the outdoors, cerium oxide could not be detected in a short period of about 3 months. On the other hand, in the coated body according to the present invention containing cerium oxide in which the amount of oxygen deficiency was controlled to be small, cerium oxide was detected even after exposure for one year.

In the present invention, the amount of oxygen deficiency of cerium oxide is controlled within a specific range. Surprisingly, in the surface layer containing both cerium oxide and titanium oxide in an amount not controlled in a specific range, the above-mentioned peculiar action of suppressing the germination and hyphal elongation of mold spores is not sufficiently exhibited. Furthermore, since the active species having strong oxidizing power generated by titanium oxide cannot be supplemented and inactivated, the surface of the lower layer or the base material in contact with the surface layer containing titanium oxide is decomposed and the coated body is deteriorated. ..

Only the coated body according to the present invention, which forms a surface layer containing both cerium oxide and photocatalytic titanium oxide in which the amount of oxygen deficiency is controlled in a specific range, has weather resistance and water resistance and has long-term outdoor resistance. It exerts a unique function of suppressing the growth of excellent mold and / or algae.

Although the reason why the above effects are realized in the present invention is not clear, it is considered that the above effects are as follows. However, the following explanation is merely a hypothesis, and the present invention is not limited to any of the following hypotheses.

In the present invention, the cerium oxide particles have an oxygen deficiency. The oxygen deficiency of cerium oxide can be substituted by the detected wave number of the peak attributed to the F _2g oscillation mode of the Ce—O bond in the Raman spectroscopic spectrum. The cerium oxide particles in the present invention belong to the F _2g vibration mode of the Ce—O bond obtained by measuring the standard substance at the peak attributed to the _F2g vibration mode of the Ce—O bond in the Raman spectroscopic spectrum. The deviation from the peak is more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low wavenumber side, and oxygen deficiency is present in the crystal having a fluorite structure. The larger the deviation, the more oxygen deficiency. The surface layer of the present invention containing such cerium oxide particles together with photocatalytic titanium oxide particles has less hydration to the trivalent Ce that exists to maintain electrical neutrality, and therefore is exposed to ultraviolet rays. Can suppress the dissolution of cerium oxide in water. In addition, it is considered that oxygen adsorbed on trivalent Ce is activated (probably in a state such as peroxide), and it is considered that a stress factor that does not cause death is given to mold spores and hyphae. Further, trivalent Ce has an effect of suppressing free radicals. Since the active species having strong oxidizing power generated by photocatalytic titanium oxide is adsorbed and inactivated, the surface layer in the present invention does not damage the mold spores and does not deteriorate the base layer of the surface layer. Then, the active species produced by the photocatalytic titanium oxide is adsorbed on cerium oxide, so that the above-mentioned stress factor increases.

Based on the above mechanism, in the present invention, specific cerium oxide and photocatalytic titanium oxide interact with each other to have weather resistance and water resistance, and have peculiar antifungal and algae resistance for a long period of time. It is thought that it is possible to provide sex.

In addition, as a result of detailed observational studies on the mechanism of algae attachment outdoors, it was found that the algae germinate mold spores and then attach to the hyphae that have grown or branched and propagate. Therefore, as a result of suppressing the growth of mold, it is presumed that the growth of algae on the painted surface could be prevented outdoors.

INDUSTRIAL APPLICABILITY The present invention makes it possible to provide a coated body and a coating composition capable of exerting an excellent function of suppressing the growth of mold and / or algae outdoors for a long period of time.

It is an optical micrograph which shows the degree of hyphal elongation "0: the spore is ungerminated state". It is an optical micrograph showing the degree of hyphal elongation "1: some spores are germinated, but the hyphae are several hundred μm or less". It is an optical micrograph showing the degree of hyphal elongation "2: spore germination is observed, and the hyphae partially extend to several hundred μm or more". It is an optical micrograph showing the degree of hyphal elongation "3: most spores germinate and hyphae grow on one side".

Painted body The coated body of the present invention is a coated body for suppressing the growth of mold and / or algae adhering to the surface, and has a base material and a surface layer formed on the base material. The surface layer contains photocatalytic titanium oxide particles and cerium oxide particles having oxygen deficiency in the fluorite structure, and the cerium oxide particles have a Ce—O-bonded F _2g vibration mode in the Raman spectroscopic spectrum. The peak attributed to is more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low frequency side with respect to the peak attributed to the F _2g vibration mode of the Ce—O bond obtained by measuring the standard material. It is out of alignment.

In one usage form of this coated body, it is preferable that the surface layer is irradiated with light containing ultraviolet rays and exposed to an environment to which mold spores adhere.

The light including ultraviolet rays is light having a wavelength band of more than 250 nm and less than 400 nm, more preferably more than 300 nm and less than 400 nm. As the light source, any of ultraviolet LED, white fluorescent lamp, artificial lighting such as black light, and sunlight can be used.

The light including ultraviolet rays may be constantly irradiated or may be occasionally irradiated. For example, use of indoor living spaces, walls such as interior spaces, windows, floors, ceilings, housing equipment, etc. that are not irradiated when sleeping or not being used but are occasionally irradiated, or exposed to outdoor sunlight. It also includes use in the environment where it is used. Further, the light including ultraviolet rays includes an artificial lighting that emits ultraviolet rays or a usage mode in which sunlight indirectly irradiates the coated body of the present invention. Indirect light here means light that is reflected, scattered, or transmitted by any object.

The coated body of the present invention has a cell membrane damage degree of less than 50% after irradiation with light containing ultraviolet rays, and an ATP value after irradiation with light containing ultraviolet rays is more than 0 RLU / cm ² and less than 500 RLU / cm ² . More preferably, it has a characteristic of more than 0 RLU / cm ² and less than 300 RLU / cm ² . The degree of cell membrane damage after irradiation with light including ultraviolet rays is more preferably less than 30%, and particularly preferably less than 10%.

As a result, germination and reproduction can be suppressed without killing the mold.

In the coated body of the present invention, the survival spore rate of the mold spores adhering to the surface is preferably more than 50%, more preferably more than 70%, and most preferably 90% after being irradiated with light containing ultraviolet rays. To be super.

By doing so, it becomes possible to more reliably exert the function of suppressing the growth of excellent mold and / or algae outdoors for a long period of time.

In a preferred embodiment of the present invention, the surface layer further contains silica particles.

By doing so, the titanium oxide particles and the cerium oxide particles can be exposed and bound to increase the strength of the surface layer.

In a preferred embodiment of the present invention, the surface layer has a porous structure, but the degree of porosity is such that the mold and / or algae do not penetrate through the layer.

The porous structure facilitates the function of titanium oxide particles and cerium oxide particles, and the non-penetrating structure prevents mold and / or algae from growing on the contact surface with the base material as a scaffold. It can be deterred.

In a preferred embodiment of the present invention, a translucent outermost layer containing silica particles is further formed on the surface of the surface layer. Here, the translucency means that the light reaches the titanium oxide particles and the cerium oxide particles contained in the surface layer.

By doing so, the functions of the titanium oxide particles and the cerium oxide particles and the functions of the silica particles can be more reliably compatible with each other.

From a functional point of view, the coated body of the present invention is a coated body for suppressing the growth of mold and / or algae adhering to the surface, and is a base material and a surface layer formed on the base material. The degree of cell membrane damage of mold spores after irradiation with light containing ultraviolet rays is less than 50%, and the ATP value after irradiation with light containing ultraviolet rays exceeds 0 RLU / cm ² and less than 500 RLU / cm ² . The surface layer is irradiated with light containing ultraviolet rays, and the coated body is exposed to an environment in which mold spores adhere to the surface of the coated body. And / or a coating body characterized by suppressing the growth of algae.

The definitions and measurement methods for "ATP value", "degree of cell membrane damage of mold spores" and "survival spore rate" in the present invention are shown below.

ATP value In the present invention, the ATP value is a value indicating the physiological activity of mold spores, and is treated as an index of the degree of influence of the coated surface on the mold spores. The ATP value is a value obtained by measuring the luminescence reaction using luciferase. The ATP value is defined as follows.

Definition of ATP value In the present invention, the "ATP value" is defined as the amount of luminescence proportional to the total amount of ATP and AMP using the enzyme cycling method combining the luminescence reaction by luciferase and the pyruvate orthophosphate dikinase.

ATP value after irradiation with light including ultraviolet rays (definition)
Spore concentration: 1 × 10 ⁵ cells / mL mold ( Nothophoma sp.) Spore solution mixed with 10% Tsapeck Dox liquid medium in an equivalent amount was applied to the entire surface of the cleaned coating (25 mm × 25 mm). Spore 0.1 mL and dry. Then, light including ultraviolet rays is irradiated in an environment where the temperature is 28 ° C. and the relative humidity is 100%. Next, the amount of light emitted that is proportional to the total amount of ATP and AMP is defined as "ATP value after irradiation of light including ultraviolet rays". This luminescence is obtained by an enzyme cycling method consisting of a luciferase luminescence reaction and a pyruvate orthophosphate dikinase using ATP and AMP as substrates. Here, for irradiation of light including ultraviolet rays, a BLB lamp (FL40SBLB manufactured by Sankyo Electric Co., Ltd.) is used as a light source, and an ultraviolet intensity of 0.5 mW / cm ² (ultraviolet intensity meter manufactured by Topcon Techno House Co., Ltd .: UVR- (Measured in 2) and irradiate for 48 hours.

Method of measuring ATP value The ATP value after irradiation with light containing ultraviolet rays is obtained by the following measuring method. The measuring method comprises steps of sample preparation, mold spore inoculation, drying, light irradiation, and quantification of ATP value after light irradiation.

(Preparation of sample)
The coated body as a sample is cut into a size of 25 mm × 25 mm in advance, cleaned by washing with water or sterilizing, and then dried to obtain a sample. The sterilization treatment is preferably a method of irradiating a germicidal lamp.

(Inoculation of mold spores)
Mold ( Nothophoma sp.) Isolated from the field was pre-cultured in potato dextrose agar slope medium at 28 ° C. for 7 to 14 days, and the spores obtained by the pre-culture were sterilized purified water containing 0.005 wt% Tween80. And dilute with sterile purified water so that the spore concentration is 1 × 10 ⁵ cells / mL to prepare a spore solution. This spore solution is mixed with a 10% Tsapeck Dox liquid medium in an equivalent amount to prepare an inoculum. After dropping 0.1 mL of the inoculum on the surface of the sample, smear it on the entire surface. The preculture period is appropriately adjusted so that the ATP value immediately before light irradiation is 100 ± 50 RLU / cm ² . The steps from the preparation of the spore solution to the smearing shall be performed on the day when the spore solution is prepared.

(Dry)
Next, the coated body smeared with the above-mentioned mixed solution is allowed to stand in a clean bench and dried at 25 ° C. for 3 hours. At that time, the inside of the clean bench is in a state where the air is agitated by a fan. The dried coated body is allowed to stand in an environment where the temperature is 28 ° C. and the relative humidity is 100%.

(Light irradiation)
The irradiation conditions of the light containing ultraviolet rays follow the above-mentioned definition of the ATP value after irradiation of the light containing ultraviolet rays.

(Quantitative ATP value)
An ATP wiping inspection system manufactured by Kikkoman Co., Ltd. is used to quantify ATP. Wipe the surface of the painted body with the company's "Lucipack (registered trademark) Pen", insert it into the company's "Lumitester (registered trademark) PD-30", measure the amount of light emission, and measure the amount of light emitted per unit area of the painted body surface. Convert to the ATP value of.

In the present invention, the function of suppressing the growth of mold and / or algae can be evaluated by the following indicators (that is, "degree of cell membrane damage of mold spores" and "survival spore rate".

Degree of damage to the cell membrane of mold spores In the present invention, the degree of damage to the cell membrane of mold spores is defined as follows.

Degree of cell membrane damage of mold spores (definition)
In the present invention, the "degree of cell membrane damage of mold spores" is determined by measuring the number of spores that emit green fluorescence by a cell membrane-permeable nuclear staining reagent and the number of spores that emit red fluorescence by a cell membrane non-permeable nuclear staining reagent. It is defined as the ratio of the number of spores that emit red fluorescence to the total number. If there are spores that have reached the stage of germination and the stage of hyphal elongation, they are excluded from the measurement target and the ratio is calculated.

Degree of cell membrane damage of mold spores after irradiation with light including ultraviolet rays (definition)
Spore concentration: 1 × 10 ⁵ cells / mL mold ( Nothophoma sp.) Spore solution was smeared on the entire surface of a sterilized coating (25 mm × 25 mm) in an amount of 0.1 mL, and after drying, the temperature was 28 ° C and the relative humidity was 28 ° C. It is defined as the degree of cell membrane damage after irradiation with light including ultraviolet rays in an environment where the humidity is controlled to 100%. Here, for irradiation of light including ultraviolet rays, a BLB lamp (FL40SBLB manufactured by Sankyo Electric Co., Ltd.) is used as a light source, and an ultraviolet intensity of 0.5 mW / cm ² (ultraviolet intensity meter manufactured by Topcon Techno House Co., Ltd .: UVR- Irradiate for 48 hours in 2).

Method for Measuring Cell Membrane Damage of Mold Spores The degree of cell membrane damage of mold spores after irradiation with light containing ultraviolet rays is determined by the following measuring method. The measuring method comprises steps of sample preparation, mold spore inoculation, drying, light irradiation, and quantification of the degree of cell membrane damage of mold spores after light irradiation.

(Preparation of sample)
It is the same as the sample preparation step in the above-mentioned measurement of ATP value.

(Inoculation of mold spores)
Mold ( Nothophoma sp.) Isolated from the field was pre-cultured in potato dextrose agar slope medium at 28 ° C. for 7 to 14 days, and the spores obtained by the pre-culture were sterilized purified water containing 0.005 wt% Tween80. And dilute with sterile purified water so that the spore concentration is 1 × 10 ⁵ cells / mL to prepare a spore solution. After adding 0.1 mL of spore solution to the surface of the sample, smear it on the entire surface.

(Dry)
It is the same as the drying step in the above-mentioned measurement of ATP value.

(Light irradiation)
The irradiation conditions of the light containing ultraviolet rays follow the above-mentioned definition of the degree of cell membrane damage of mold spores after irradiation of the light containing ultraviolet rays.

(Quantification of cell membrane damage of mold spores)
The quantification procedure follows:
(1) Use the nuclear staining kit "LIVE / DEAD ^TM FungaLight ^TM Yeast Viability Kit, for flow cytometry" manufactured by Thermo Fisher. In sterile purified water, SYTO ^TM 9 Stain (cell membrane permeable nuclear staining reagent, hereinafter referred to as SYTO 9) has a concentration of 15 μM, and Propidium iodide (cell membrane impermeable nuclear staining reagent, hereinafter referred to as PI) has a concentration of 75 μM. To prepare a fluorescent staining solution in which two types of staining reagents are dissolved.
(2) 50 μL of the fluorescent dyeing solution is dropped onto the surface of the coated body. After allowing the sample to which the fluorescent staining solution was dropped to stand at 25 ° C. for 30 minutes under shading, the excess fluorescent staining solution was washed with water and irradiated with laser light having a wavelength of 488 nm and 561 nm as excitation light using a confocal fluorescence microscope. Then, observe the fluorescence emitted by the two types of nuclear staining reagents. SYTO9 fluoresces in the wavelength range of 493 to 584 nm and exhibits a green color. On the other hand, PI fluoresces in the wavelength range of 584 to 627 nm and exhibits a red color.
(3) Of the mold spores observed at a magnification of 340 times, those that reached the stage of germination / hyphal elongation were excluded, and the number of spores emitting green fluorescence and spores emitting red fluorescence was measured and the spores were measured. Let the total be the total number of spores. The spores emitting red fluorescence are regarded as "with membrane damage", and the ratio of the number of spores with "with membrane damage" to the total number of spores is calculated and used as the degree of cell membrane damage.

Surviving spore rate In the present invention, the surviving spore rate is defined as follows.

Survival spore rate (definition)
Spore concentration: 1 × 10 ⁵ cells / mL of mold ( Nothophoma sp.) Spore solution was smeared on each entire surface (25 mm × 25 mm) of the glass plate as a control with the cleaned coating body, and dried. After that, after irradiating with light in an environment where the temperature was 28 ° C and the relative humidity was 100%, the spores were collected, mixed with 10% Tsapeck Dox agar medium, and cultured at 28 ° C for 7 days to form colonies. Let the number be the number of surviving spores. The ratio of the number of viable spores on the surface of the coated body to the number of viable spores of the control is defined as the viable spore rate.

Survival spore rate after irradiation with light including ultraviolet rays (definition)
"Light irradiation" in the above definition of the survival spore rate is defined as an irradiation condition of light including ultraviolet rays. The condition is 24 hours with a BLB lamp (FL40SBLB manufactured by Sankyo Electric Co., Ltd.) as a light source and an ultraviolet intensity of 0.5 mW / cm ² (ultraviolet intensity meter manufactured by Topcon Techno House: measured by UVR-2). It shall be irradiated.

Method for measuring the survival spore rate The survival spore rate after irradiation with light containing ultraviolet rays is determined by the following measurement method. The measuring method comprises steps of sample preparation, mold spore inoculation, drying, light irradiation, and quantification of the survival spore rate after light irradiation.

(Preparation of sample)
It is the same as the sample preparation step in the above-mentioned measurement of ATP value. A glass plate is prepared as a control, and the treatment is treated in the same manner as the painted body.

(Inoculation of mold spores)
This is the same as the step of inoculating mold spores in the above-mentioned measurement of the degree of cell membrane damage of mold spores. The same operation as for the painted body is performed for the control.

(Dry)
It is the same as the drying step in the above-mentioned measurement of ATP value. The same operation as for the painted body is performed for the control.

(Light irradiation)
Irradiation conditions for light containing ultraviolet light follow the definition of viable spore rate after irradiation with light containing ultraviolet light described above.

(Quantification of survival spore rate of mold spores)
The quantification procedure follows:
After light irradiation, the coated body and the control were sealed in a stomacher bag together with 4.5 ml of a recovered solution (an aqueous solution containing 0.005 wt% of sodium dioctylsulfonate and 0.891 wt% of sodium chloride, respectively), and ultra-sonicated. Using a sonic cleaner (AS ONE, V-F100), ultrasonic irradiation is performed at an output of 100 W (50 kHz) for 5 minutes to recover mold and spores from the surface of the painted body. Next, the recovered solution containing spores is mixed with 10% Tsapeck Dox agar medium and cultured at 28 ° C. for 7 days, and the number of formed colonies is defined as the number of surviving spores. The ratio of the number of viable spores on the surface of the coated body to the number of viable spores of the control is defined as the viable spore rate.

Base material The base material used in the above-mentioned coated body of the present invention can be a metal, an inorganic material, an organic material, or a composite material thereof. Specific examples thereof include tiles, sanitary ware, tableware, calcium silicate plates, cement extruded plates, ceramic substrates, new ceramics such as semiconductors, insulators, glass, mirrors, wood, and resins. Examples of base materials used for members include building exterior materials, building interior materials, window frames, window glass, structural members, vehicle exteriors, dustproof covers for articles, traffic signs, and various display devices. Advertising towers, road soundproof walls, railroad soundproof walls, bridges, guard rails, tunnel interiors and paints, glass, solar cell covers, solar water heater heat collector covers, vinyl houses, vehicle lighting covers, housing equipment, toilets, Examples include tubs, washbasins, lighting fixtures, lighting covers, kitchen utensils, dishwashers, dish dryers, sinks, cooking ranges, kitchen hoods, ventilators, protective films, etc. The above-mentioned member also includes a member having a film formed by printing, painting, coating, laminating or the like.

Surface layer The surface layer of the present invention comprises photocatalytic titanium oxide particles and cerium oxide particles having oxygen deficiency in the fluorite structure, and the cerium oxide particles are C—O-bonded F _2g vibrations in the Raman spectroscopic spectrum. The peak attributed to the mode exceeds 1.0 cm ^-1 on the low frequency side and 9.9 cm ^-1 with respect to the peak attributed to the F _2g vibration mode of the Ce—O bond obtained by measuring the standard material. Contains cerium oxide particles that are less than offset.

In one embodiment of the coated body of the present invention, the surface layer formed on the base material is located on the outermost surface of the coated body.

In one embodiment of the present invention, the surface layer is irradiated with light including ultraviolet rays. In the surface layer, the degree of cell membrane damage of mold spores after irradiation with light containing ultraviolet rays is less than 50%, and the ATP value after irradiation with light containing ultraviolet rays exceeds 0 RLU / cm ² and 500 RLU / cm ² . It is preferably less than, more preferably more than 0 RLU / cm ² and less than 300 RLU / cm ² . The degree of cell membrane damage after irradiation with light including ultraviolet rays is more preferably less than 30%, and particularly preferably less than 10%.

In another embodiment of the present invention, the surface layer preferably has a survival spore rate of more than 50% of mold spores adhering to the surface after irradiation with light including ultraviolet rays.

From a functional point of view, the surface layer of the present invention has a degree of cell membrane damage of mold spores of less than 50% after irradiation with light containing ultraviolet rays, and an ATP value of 0 RLU / after irradiation with light containing ultraviolet rays. It has a characteristic of more than cm ² and less than 500 RLU / cm ² , and it is preferable that the surface layer is irradiated with light containing ultraviolet rays and exposed to an environment to which mold spores adhere.

It is preferable that the surface layer of the present invention further contains silica particles. In addition, it is permissible to contain any component other than silica particles that does not impair the function of the present invention.

The surface layer of the present invention preferably has a porous structure in which the mold and / or algae do not penetrate through the layer.

For that purpose, it is preferable that the matrix component in the surface layer is less than 30% by mass, more preferably less than 10% by mass, and further preferably 0% by mass.

Further, as a structure in which the mold and / or algae do not penetrate through the layer, the average crack width calculated by the crack area ÷ (crack circumference ÷ 2) is preferably less than 3 μm, more preferably less than 1 μm. Is preferable. Here, the crack area and the crack peripheral length are measured by image analysis using a scanning electron microscope.

In the coated body of the present invention, the surface layer having a film thickness of 0.1 μm or more and 5 μm or less, more preferably 0.3 μm or more and 3 μm or less, and most preferably 0.5 μm or more and 2 μm or less, suppresses mold growth and resists mold growth. It is preferable from the viewpoint of compatibility with wear resistance. Here, the film thickness can be measured based on the cross-sectional observation with an electron microscope.

Photocatalytic Titanium Oxide Particles The titanium oxide particles used in the present invention are particles made of titanium oxide that functions as a photocatalyst, and the titanium oxide is preferably titanium dioxide. In the present invention, titanium dioxide preferably has an anatase type crystal structure. In the present invention, when the crystal structure of the photocatalytic titanium oxide is anatase type, the amount of active species produced is large under ultraviolet irradiation, so that the stress factor can be increased more effectively. As a result, it is believed that it exhibits excellent antifungal and algae resistance. Further, in the present invention, the titanium oxide particles may coexist with an auxiliary catalyst such as a copper compound or other known photocatalytic particles.

Cerium oxide particles The cerium oxide particles used in the present invention are cerium oxide particles having an oxygen deficiency of fluorite structure, and the peak attributed to the F _2g vibration mode of the Ce—O bond in the Raman spectral spectrum is With cerium oxide particles that are more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low wave number side with respect to the peak attributed to the F _{2 g} vibration mode of the Ce—O bond obtained by measuring the standard material. be.

In the present invention, the cerium oxide having an oxygen deficiency means cerium oxide having a non-quantitative composition of CeO _2-x (0 <x <1).

Here, as the standard substance, cerium (IV) oxide, purity 99.99% (CEO04PB) manufactured by the Institute of High Purity Chemistry is used. The peak attributed to the F _2g vibration mode of the Ce—O bond obtained by measuring the standard material appears at a wave number of about 460 cm ^-1 according to the following measurement conditions. In the present invention, the deviation to the low wavenumber side is defined by the deviation from the detected wavenumber where the peak attributed to the F _2g vibration mode of the Ce—O bond of the standard material is detected.

The conditions for Raman spectroscopy are described in detail below.
Equipment: Nanophoton RAMANTouch
Laser wavelength: 532nm
Laser power: The laser power was adjusted so that the scattering intensity of the F _2g vibration mode of the Ce—O bond was as high as possible (over 3000 cps) without exceeding the measurable upper limit.
Pinhole size: 50 μm
Diffraction grating: 2400gr / mm
Center wave number: 460 cm ^-1
Irradiation time: 300 seconds Total number of times: 1 Objective lens: TU Plan Fluor x 100 (NA: 0.90)

The wave number of the peak attributed to the F _2g vibration mode of the Ce—O bond The smaller the amount of cerium oxide in the specified sample, and the more cerium oxide contains oxygen defects, the broader the peak obtained, so that the peak becomes The wave number may be unclear. Therefore, in the present invention, the wave number attributed to the peak is calculated as follows.
1) Five points were measured for the same sample.
2) For each measurement result, specify the wavenumber range where the intensity of 95% or more is obtained with respect to the maximum intensity of the peak confirmed in the wavenumber range of 450 to 470 cm ^-1 , and calculate the wavenumber at the center. The center wave number of the peak was used. The wave number range in which an intensity of 95% or more can be obtained was specified by setting the minimum wave number in which an intensity of 95% or more can be obtained and the maximum wave number in which an intensity of 95% or more can be obtained at both ends. The obtained Raman spectrum has a predetermined amplitude derived from noise. Therefore, a point having an intensity of less than 95% may be obtained within the wave number range. In such a case, the wavenumber range was specified by including the points having an intensity of less than 95% in the wavenumber range.
3) Of the center wavenumbers of the peak obtained from the measurement results at 5 points, the average value of 3 points excluding the maximum and minimum values is attributed to the F _2g vibration mode of the Ce-O bond of the sample. The peak wave number was used.

Cerium oxide manufactured by High Purity Chemical Laboratory: Part number CEO04PB, lot number 4702411 as standard material, obtained by measuring the sample for the wave number at which the peak attributed to the F _2g vibration mode of the Ce—O bond is detected. The difference in the wave number at which the peak belonging to the same mode is detected is defined as the deviation to the low wave number side.

In the present invention, the lower limit of the peak shift is more than 1.0 cm ^-1 . As a result, it is possible to suppress the oxidizing power derived from titanium oxide, and it is expected that the weather resistance performance will be improved and the peculiar antifungal effect and algae-proofing effect derived from cerium oxide will be maintained for a long period of time.

In the present invention, the upper limit of the peak deviation is less than 9.9 cm ^-1 , preferably less than 5.0 cm ^-1 . As a result, the elution rate of cerium oxide due to photolysis can be significantly reduced, and it is expected that the water resistance will be improved and the peculiar effect of cerium oxide will be maintained for a long period of time.

In the present invention, the evaluation by Raman spectroscopy uses (1) a sample prepared from a powder obtained by taking out a surface layer from a coated body and pulverizing it, or a powder obtained by drying a coating composition. Alternatively, (2) the coated body can be used as a sample.

For the preparation of the sample in (1), select one of the following.
-The surface layer formed on the surface of the base material is washed with ultrapure water, dried, and then used as a sample. Washing is performed until the electrical conductivity of the water after washing becomes 10 μS / cm or less.
-Peel off the surface layer from the painted body, crush it in a mortar, etc., and then wash it with ultrapure water. Washing is performed until the electrical conductivity of the washing water becomes 10 μS / cm or less. The crushed product after washing is dried and used as a sample.
-The coating composition described later is dried, and the obtained dried product is washed with ultrapure water. Washing is performed until the electrical conductivity of the water after washing becomes 10 μS / cm or less. After washing, it is dried and used as a sample.

For the preparation of the sample in (2), select one of the following.
-On the substrate side of the surface layer on the substrate side, that is, on the intermediate layer existing between the substrate or the substrate and the surface layer and in contact with the surface layer, or in contact with the surface layer. In the case of a coated body that does not contain a component having a Raman peak (for example, rutile-type titanium oxide) having a Raman peak close to the F _2g vibration mode of the Ce—O bond with a wave number of around 460 cm ^-1 , ultrapure water is used. After washing and drying, the sample is used as it is. Washing is performed until the electrical conductivity of the water after washing becomes 10 μS / cm or less.
-Use quartz glass plate or soda lime glass as the base material. The substrate is washed in advance and a coating composition is applied to the surface of the clean substrate to form a surface layer. The coated body composed of the base material and the surface layer is washed with ultrapure water and dried, and then used as a sample. Washing is performed until the electrical conductivity of the water after washing becomes 10 μS / cm or less.

The content ratio of the titanium oxide particles and the cerium oxide particles in the surface layer can be appropriately selected in the range of 1/99 to 99/1 for titanium oxide / cerium oxide in terms of mass ratio.

Further, the average crystallite diameter of the cerium oxide particles is preferably more than 6 nm, more preferably less than 64 nm. Here, the average crystallite diameter is obtained by the measuring method described in Examples described later. When the crystallite diameter is larger than 6 nm, it can be expected that the amount of oxygen defects exposed on the surface will be smaller. Thereby, the dissolution of cerium oxide in water can be suppressed under the irradiation of ultraviolet rays.

Silica particles The surface layer may further contain silica particles. By doing so, the cerium oxide particles can be exposed and bound to increase the strength of the surface layer.

The silica particles are preferably added to the surface layer of the coating body in an amount of preferably 30% by mass or more, more preferably 50% by mass or more, and most preferably 70% by mass or more. By doing so, the hydrophilicity and the abrasion resistance of the surface layer are improved.

The silica particles are preferably contained in the surface layer of the coating body in an amount of less than 90% by mass. By doing so, the hydrophilicity and the abrasion resistance of the surface layer can be compatible with the functions of the cerium oxide particles.

The average particle size of the silica particles is preferably less than 100 nm, more preferably less than 50 nm, still more preferably less than 30 nm. By doing so, the wear resistance of the surface layer becomes good, and it is also effective for maintaining the weather resistance performance for a long period of time.

The average particle size of the silica particles is calculated as a number average value obtained by measuring the length of any 100 particles that enter the field of view 200,000 times with a scanning electron microscope. As the shape of the particles, a true sphere is the best, but it may be substantially circular or elliptical, and the length of the particles in that case is approximately calculated as ((major axis + minor axis) / 2).

Optional component The surface layer may contain, as an optional component, oxide particles other than the titanium oxide particles, cerium oxide particles and silica particles, or a non-particle component.

Examples of the oxide particles other than the titanium oxide particles, the cerium oxide particles and the silica particles include single oxide particles such as alumina, zirconia, boronia and silicate, borosilicate, aluminosilicate and barium titanate. Particles of composite oxides such as, etc. can be used.

(Non-particle component)
The content of the non-particle component is preferably less than 10 parts by mass when the total amount of the film-forming components constituting the surface layer is 100 parts by mass. By doing so, the surface layer tends to have a porous structure in which mold and / or algae do not penetrate through the layer. Since the coating film has a porous structure, the function of the cerium oxide particles can be exhibited.

As the non-particle component, for example, a matrix component or the like can be used. As the matrix component, an organic resin, an organic-inorganic composite resin, an organic or inorganic polymer and the like can be used.

As the organic resin, for example, a compound such as an acrylic resin, a urethane resin, or an acrylic urethane resin can be used.

Examples of the organic-inorganic composite resin include a composite of a silicon compound and a compound constituting the organic resin. The organic-inorganic composite resin that can be preferably used is a composite of silicone and the above-mentioned organic resin, and specifically, a silicone resin, a silicone-modified resin, or the like can be used.

As the organic polymer, for example, polyoxyalkylenes such as polyethylene oxide, polypropylene oxide and block polymers thereof can be used.

Examples of the inorganic polymer include a single oxide of a metal such as silicon, titanium, zirconium, and tin, a composite oxide of these metals, or a composite oxide of these metals and sodium, potassium, or lithium. Is available. These compounds are preferably produced at the time of surface layer formation by applying a soluble precursor compound to a dispersion medium described later.

Outer surface layer The coated body of the present invention may further form an outermost surface layer on the surface of the surface layer. Since the outermost surface layer has translucency, the titanium oxide particles and the cerium oxide particles contained in the surface layer can be irradiated with light containing ultraviolet rays. The outermost layer preferably has a thickness of 1 μm or less, 0.5 μm or less, or 0.1 μm or less. By doing so, the hydrophilicity of the surface can be improved more reliably, and the self-cleaning effect can be enhanced. Further, the outermost layer preferably has substance permeability, and more preferably porous. Preferred embodiments of the outermost layer include a porous film containing the above-mentioned silica particles and a porous film made of the above-mentioned silica particles.

Method for Forming a Painted Body The coated body of the present invention is formed by forming a surface layer on a base material. As a method for forming the surface layer, a wet film forming method can be preferably used.

Examples of the wet film forming method include a method including a step of applying a coating composition described later to the surface of a substrate.

For application of the coating composition to the substrate, application by spray, roll coating, die coating, or flow coating is preferably available. Further, the coating may be performed manually or by a machine.

In the wet film forming method by coating, the coating may be applied on a factory production line or on-site. The drying or heating conditions after coating may be any conditions as long as the functions of the titanium oxide particles and the cerium oxide particles are not impaired, and for example, temperature conditions of about room temperature to 500 ° C. can be preferably used. Pretreatment such as preheating, discharge treatment, plasma treatment, acid / alkali treatment of the substrate before coating, and post-treatment such as discharge treatment, plasma treatment, acid / alkali treatment, and heating can be added as appropriate.

Uses of Painted Body The painted body of the present invention can be widely used as an outdoor member that needs to suppress the growth of mold and algae.

As outdoor members, it is suitably used for building exterior materials, outer walls, roofs, rooftop equipment, solar cell covers, solar water heater heat collecting covers, greenhouses, windowpanes, window sashes, etc., and films fixed to their surfaces. can.

The coated body of the present invention can also be used as an indoor member in an environment irradiated with light including ultraviolet rays. Indoor materials include sanitary ware, washbasins, washbasins, unit baths, bathroom mirrors, kitchens, kitchen sinks, bathroom walls, bathroom floors, bathroom ceilings, water-related equipment such as local cleaning devices, stoves, ranges, kitchen hoods, etc. Ventilation fan, cutting board, tableware, refrigerator, dishwasher, dish dryer and other kitchen utensils, indoor tiles, doors, interior paper, window glass, window sashes, storage furniture, house storage structural materials, ceilings, floors, walls, etc. It can be suitably used for building interior materials, bedding, chairs, desks, lighting fixtures, housing equipment such as air conditioning equipment, vehicle equipment, and films fixed to their surfaces.

Coating composition

The coating composition provided by one aspect of the present invention can be coated on a substrate to form the above-mentioned coated body. Therefore, the coating composition of the present invention can exhibit an excellent function of suppressing the growth of mold and / or algae outdoors for a long period of time by coating the substrate.

Also in the embodiment of the coating composition, the following embodiments can be said to be preferable for the same reason as the above-described embodiment of the coated body.

Therefore, one aspect of the coating composition of the present invention comprises photocatalytic titanium oxide particles and cerium oxide particles having an oxygen deficiency in the fluorite structure, and the cerium oxide particles are Ce in the Raman spectroscopic spectrum. The peak attributed to the F _2g vibration mode of the -O bond is 1.0 cm ^-1 on the low frequency side with respect to the peak attributed to the F _2g vibration mode of the Ce-O bond obtained by measuring the standard material. It is more than 9.9 cm and the deviation is less than ^-1 . A coating body provided with a surface layer obtained by coating this coating composition on a substrate suppresses the growth of mold and / or algae adhering to the surface thereof.

In the coating composition of the present invention, as the photocatalytic titanium oxide particles and the cerium oxide particles, those having the properties described in the description in the above-mentioned coated body can be used.

In the coating composition of the present invention, the photocatalytic titanium oxide particles and the cerium oxide particles can be used as raw materials in either powder or dispersion.

The coating composition may further contain silica particles. By doing so, the cerium oxide particles can be exposed and bound to increase the strength of the surface layer.

The average particle size of the silica particles is preferably less than 100 nm, more preferably less than 50 nm, still more preferably less than 30 nm. By doing so, the wear resistance of the surface layer becomes good, and it is also effective for maintaining the weather resistance performance for a long period of time.

The average particle size of the silica particles is calculated as a number average value obtained by measuring the length of any 100 particles that enter the field of view 200,000 times with a scanning electron microscope. As the shape of the particles, a true sphere is the best, but it may be substantially circular or elliptical, and the length of the particles in that case is approximately calculated as ((major axis + minor axis) / 2).

The silica particles are preferably added to the film-forming component in the coating composition in an amount of preferably 30% by mass or more, more preferably 50% by mass or more, and most preferably 70% by mass or more. By doing so, the hydrophilicity and the abrasion resistance of the surface layer are improved.

The silica particles are preferably contained in the film-forming component in the coating composition in an amount of preferably less than 90% by mass. By doing so, it is possible to achieve both the hydrophilicity and the abrasion resistance of the surface layer and the function based on the interaction between the photocatalytic titanium oxide particles and the cerium oxide particles.

Here, the film-forming component is a component constituting the surface layer in the present invention, and as essential components, titanium oxide particles and cerium oxide particles, and as optional components, silica particles, oxidation other than the essential components and silica particles. It is a physical particle as well as a non-particle component. In the coating composition, if precursors of these components are present, the product after the composition is applied is the film-forming component.

When the particle component and the non-particle component do not contain an organic component, a dispersion medium contained in the coating composition or an additive that is non-reactive and soluble in the dispersion medium (eg, a surfactant, a thickener, or a thickener). High boiling point solvent, etc.) shall not correspond to the film-forming component. In this case, the quantification of the film-forming component is determined from the constant amount value of the ignition residue after heating at 400 ° C. of the coating composition.

When the particle component and the non-particle component contain an organic component, the quantification of the film-forming component shall be performed by obtaining a constant amount after heating the coating composition to 110 ° C.

The coating composition of the present invention preferably contains a film-forming component in an amount of 0.1% by mass or more and 80% by mass or less.

The coating composition of the present invention preferably contains a dispersion medium. The dispersion medium can be used alone with water or a known organic solvent, or a mixture thereof.

The coating composition can be prepared by dispersing titanium oxide particles, cerium oxide particles, and other solid components or precursors thereof to be added as necessary in a dispersion medium. For on-site painting, this method is more convenient.

The coating composition may contain, as an optional component, at least one selected from titanium oxide particles, cerium oxide particles, oxide particles other than silica particles, non-particle components and additives.

Examples of the oxide particles other than the above titanium oxide particles, cerium oxide particles and silica particles include single oxide particles such as alumina, zirconia, boronia and silicate, borosilicate, aluminosilicate and titanium acid. Particles of composite oxides such as barium can be used.

In a preferred embodiment of the present invention, the non-particle component is less than 10 parts by mass when the total solid content in the coating composition is 100 parts by mass.

By doing so, it becomes easy to form a porous structure in which mold and / or algae do not penetrate through the layer when a film is formed on the substrate. The porous structure of the coating facilitates the function of the cerium oxide particles, and the non-penetrating structure facilitates the growth of mold and / or algae on the contact surface with the substrate. Can be suppressed.

As the non-particle component, for example, a matrix component or the like can be used.

As the matrix component, an organic resin, an organic-inorganic composite resin, an organic or inorganic polymer, a polymer of an organic metal, or the like can be used.

As the organic resin, for example, a compound such as an acrylic resin, a urethane resin, or an acrylic urethane resin can be used in the form of a solution or a dispersion. Alternatively, precursors capable of forming these resins, such as monomers having unsaturated double bonds, isocyanate compounds, amines, and oligomers thereof, are also available.

Examples of the organic-inorganic composite resin include a composite of a silicon compound and a compound constituting the organic resin. The organic-inorganic composite resin that can be preferably used is a composite of silicone and the above-mentioned organic resin, and specifically, a silicone resin, a silicone-modified resin, or the like can be used in the form of a solution or a dispersion. Alternatively, a precursor capable of forming silicone and a precursor capable of forming the above organic resin are also available.

As the organic polymer, for example, polyoxyalkylenes such as polyethylene oxide, polypropylene oxide and block polymers thereof can be used.

Examples of the inorganic polymer include a single oxide of a metal such as silicon, titanium, zirconium, and tin, a composite oxide of these metals, or a composite oxide of these metals and sodium, potassium, or lithium. A precursor capable of forming is available. Metal salts, metal halide compounds, metal alkoxides, and hydrolysates thereof, or metal peroxides can be used as such precursors.

As the additive, known leveling agents, antifoaming agents, dispersants, pH adjusters and the like can be used.

In a preferred embodiment of the present invention, the coating composition further contains a dispersion medium. This facilitates the formation of a homogeneous film on the substrate. As the dispersion medium, water and / or a non-aqueous solvent can be preferably used, and as the non-aqueous solvent, a known organic solvent can be used. Solvents can be suitably used.

Usage of the coating composition As one usage of the coating composition, after forming a coated body having a surface layer coated on a substrate, light including ultraviolet rays is irradiated and the coated body is irradiated with light. It is used in a form that suppresses the growth of mold and / or algae adhering to the surface of the surface.

Method for Preventing Biofouling The method for suppressing mold growth of the present invention is a method for allowing a substance that suppresses the metabolism of the spores to act on the spores without damaging the cell membrane of the spores of the mold.

Further, the method for suppressing algae growth of the present invention is a method for suppressing the growth of mold by allowing a substance that suppresses the metabolism of the spores to act on the spores without damaging the cell membrane of the spores of the mold.

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples.

Materials Base material / base material a Soda lime glass plate / base material b An aluminum base material was coated with a primer mainly containing an epoxy resin and dried at room temperature for 24 hours. Then, the base material b was further coated with an enamel paint containing a silicone-modified acrylic resin and a white pigment and dried at room temperature for 24 hours.

Cerium oxide particles Table 1 1-1 to 1-9 show various physical properties. All are aqueous dispersions and have a fluorite-type crystal structure.

Titanium oxide particles Table 1 2-1 shows various physical properties. It is an anatase-type aqueous dispersion of titanium oxide.

Silica particles Table 1 3-1 to 3-3 show various physical properties. Water-Na dispersed colloidal silica.

The particle diameter and crystallite diameter in Table 1 show the data acquired by the method described later.

Test 1: Evaluation of physical properties
Test 1 (1): Particle size distribution measurement 1 mL of the aqueous dispersion shown in Table 1 was added to a cell (Tayo Co., Ltd .: model number BRA759116) and subjected to particle size distribution measurement by a dynamic light scattering method. The silica particles of 3-1 to 3-3 in Table 1 were measured by diluting them 2-fold with purified water. The equipment and conditions are as follows.
Equipment: ELSZ-1000 (manufactured by Otsuka Electronics Co., Ltd.)
Measurement conditions Measurement temperature: No control (normal temperature measurement)
Light intensity adjustment: Automatic adjustment Dust cut count: 0
Optimal light intensity: 30000
Maximum light intensity: 50000
Minimum light intensity: 10000
Pinhole (μm): 50
Analysis conditions Analysis method: Marquardt
Side cut (left): 0
Side cut (right): 0
Analysis range: G2 (t) (1.003 ~ 2)
Iteration: 1000
Noise cut level (%): 1
Cell condition Measurement item: size
Measurement sequence: Type2
Cell selection: Size Cell (Dispo)
Cell type: Size Cell
Accumulation count: 30
Solvent conditions Solvent selection: WATER ,,
Refractive index: 1.33
Viscosity: 0.89
Permittivity: 78.3

Table 1 shows the cumulative distribution diameter D50 of the scattering intensity distribution obtained above.

Test 1 (2): Crystalline diameter measurement
Preparation of sample The particle raw materials 1-1 to 1-9 in Table 1 were freeze-dried. Ultrapure water was added to the obtained dried product, stirring was performed, water was removed, and the dried product was washed by freeze-drying again. The washing operation was repeated until the conductivity of the washing water became less than 10 μS / cm. These were used as samples for measuring the crystallite diameter.

The average crystallite diameter of the cerium oxide particles was determined by powder X-ray diffraction. Specifically, the full width at half maximum (FWHM) of the strongest line peak (corresponding to the crystal plane 111) described in the 2θ peak pattern (ICDD card number: 01-078-5328) of cerium oxide having a fluorite structure is measured. Calculated by the Scherrer formula. The analysis conditions of the powder X-ray diffraction method are shown below.
Analyzer Spectris X'Pert PRO MPD
X-ray source CuKα
Divergence slit 1.0 mm
Scan method Continuous scan method Scan axis 2 θ / θ
Measuring range 10-90 °
Sampling interval 0.05 °
Scan speed 0.1 ° s ^-1
Tube voltage 45 kV
Tube current 40 mA

The results are shown in Table 1.

Preparation of Coating Composition The (1) cerium oxide aqueous dispersion, (2) aqueous dispersion colloidal silica, and (3) titanium oxide aqueous dispersion shown in Table 1 so as to have the composition shown in Table 2. , (4) Dispersion medium and (5) Additive were mixed to obtain a coating composition. The concentration of the film-forming component in the coating composition was 5.5% by mass. Here, the concentration of the film-forming component is the concentration of the total amount (charged amount) of (1) to (3) in the coating composition. For reference, the coating composition was heated to 400 ° C., slowly cooled to room temperature, and the concentration at a constant volume was measured. As a result, the obtained concentration was equivalent to the concentration of the film-forming component. Purified water was used as the dispersion medium, and a polyether-modified silicone-based surfactant was used as the additive.

Test 1 (3) Raman spectroscopy
Preparation of painted body 1
The substrate a is heated to 55 ° C., the coating composition shown in Table 2 is applied to the surface thereof by air spray at a coating amount of 12.5 g / m ² , dried at room temperature, and Raman. It was used as a sample for spectroscopic measurement.

The conditions for Raman spectroscopy are as follows.
Equipment: Nanophoton RAMANTouch
Laser wavelength: 532nm
Laser power: The laser power was adjusted so that the scattering intensity of the Ce—O coupled F _2g vibration mode was as high as possible (greater than 3000 cps) without exceeding the measurable upper limit.
Pinhole size: 50 μm
Diffraction grating: 2400gr / mm
Center wave number: 460 cm ^-1
Irradiation time: 300 seconds Total number of times: 1 Objective lens: TU Plan Fluor x 100 (NA: 0.90)
CCD cooling temperature: -67 ° C

The wave number of the peak attributed to the F _2g vibration mode of the Ce—O bond The smaller the amount of cerium oxide in the specified sample, and the more cerium oxide contains oxygen defects, the broader the peak obtained, so that the peak becomes The wave number may be unclear. Therefore, in the present invention, the wave number attributed to the peak is calculated as follows.
1) Five points were measured for the same sample.
2) For each measurement result, specify the wavenumber range where the intensity of 95% or more is obtained with respect to the maximum intensity of the peak confirmed in the wavenumber range of 450 to 470 cm ^-1 , and calculate the wavenumber at the center. The center wave number of the peak was used. The wave number range in which an intensity of 95% or more can be obtained was specified by setting the minimum wave number in which an intensity of 95% or more can be obtained and the maximum wave number in which an intensity of 95% or more can be obtained at both ends. The obtained Raman spectrum has a predetermined amplitude derived from noise. Therefore, a point having an intensity of less than 95% may be obtained within the wave number range. In such a case, the wavenumber range was specified by including the points having an intensity of less than 95% in the wavenumber range.
3) Of the center wavenumbers of the peak obtained from the measurement results at 5 points, the average value of 3 points excluding the maximum and minimum values is attributed to the F _2g vibration mode of the Ce-O bond of the sample. The peak wave number was used.

The deviation to the low wavenumber side is the wavenumber at which the peak attributed to the F _2g vibration mode of the Ce—O bond is detected using cerium oxide manufactured by the Institute of High Purity Chemistry: Part No. CEO04PB and Lot No. 4702411 as the standard material. , The difference from the wave number at which the peak belonging to the same mode obtained by measuring the coated body was detected was obtained.

Table 3 shows the deviation of the peak attributable to the F _2g vibration mode of the Ce—O bond measured and calculated by the above method toward the low wavenumber side.

Test 2: Evaluation of the painted body by irradiation with light including ultraviolet rays
Preparation of painted body 2
Using the base material b, a coated body was produced in the same manner as in Preparation 1 of the coated body.

Test 2 (1): ATP value after irradiation with light containing ultraviolet rays Mold isolated from the field ( Nothophoma sp.) Was pre-cultured in potato dextrose agar slope medium at 28 ° C. for 7 to 14 days. The spores obtained by preculture are suspended in sterile purified water containing 0.005 wt% Tween80, diluted with sterile purified water so that the spore concentration is 1 × 10 ⁵ cells / mL, and the inoculum is prepared. Prepared. This inoculant solution was mixed with a 10% Tsapeck Dox liquid medium in an equivalent amount to prepare a mixed solution. 0.1 mL of the mixed solution was added dropwise to the surface of the coated body (cut to 25 mm × 25 mm) sterilized by irradiation with a germicidal lamp, and then smeared on the entire surface. Next, the coated body smeared with the above-mentioned mixed solution was allowed to stand in a clean bench and dried at 25 ° C. for 3 hours. At that time, the inside of the clean bench was in a state where the air was agitated by a fan. The dried coated body is allowed to stand in an environment where the temperature is 28 ° C and the relative humidity is 100%, and a BLB lamp (FL40SBLB manufactured by Sankyo Electric Co., Ltd.) is used as a light source, and the ultraviolet intensity is 0.5 mW /. It was irradiated with cm ² (ultraviolet intensity meter manufactured by Topcon Techno House Co., Ltd .: measured by UVR-2) for 48 hours.

An ATP wiping inspection system manufactured by Kikkoman Co., Ltd. was used to quantify the ATP value. The surface of the painted body after being irradiated with light containing ultraviolet rays is wiped off with the company's "Luciferin (registered trademark) Pen" and inserted into the company's "Lumitester (registered trademark) PD-30" to be catalyzed by luciferase. The amount of light emitted by the reaction of luciferin, oxygen, and ATP was measured and converted into the ATP value per unit area of the coated surface.

Test 2 (2): Degree of cell membrane damage of mold spores after UV irradiation 0.1 mL of inoculum prepared in the same manner as in Test 2 (1) was cut into a coated body (25 mm × 25 mm) sterilized by germicidal lamp irradiation in advance. ) Was dropped on the surface and then smeared on the entire surface. Next, the coated body smeared with the inoculum was allowed to stand in a clean bench and dried at 25 ° C. for 3 hours. At that time, the inside of the clean bench was in a state where the air was agitated by a fan. The dried coated body is allowed to stand in an environment where the temperature is 28 ° C and the relative humidity is 100%, and a BLB lamp (FL40SBLB manufactured by Sankyo Electric Co., Ltd.) is used as a light source, and the ultraviolet intensity is 0.5 mW /. It was irradiated with cm ² (ultraviolet intensity meter manufactured by Topcon Techno House Co., Ltd .: measured by UVR-2) for 48 hours.

A nuclear staining kit "LIVE / DEAD ^TM FungaLight ^TM Yeast Viability Kit, for flow cytometry" manufactured by Thermo Fisher was used. A fluorescent staining solution was prepared by dissolving SYTO9 at a concentration of 15 μM and PI at a concentration of 75 μM in sterile purified water. 50 μL of the fluorescent staining solution was dropped onto the surface of the coated body (that is, the coated body in which the sample was inoculated with mold spores, dried and then irradiated with light) subjected to the operation described in the previous stage. The sample to which the fluorescent stain was dropped was allowed to stand at 25 ° C. under the light of light for 30 minutes, and then the excess fluorescent stain was removed. Next, using a confocal fluorescence microscope, laser light having wavelengths of 488 nm and 561 nm was irradiated on the surface of the coated body as excitation light, and the appearance of green fluorescence and red fluorescence emitted by the two types of nuclear staining reagents was observed.

The observation was performed at a magnification of 340 times. Of the observed mold spores, those that reached the stage of germination and hyphal elongation were excluded, and the number of spores emitting green fluorescence and spores emitting red fluorescence was measured, and the total was taken as the total number of spores. did. The spores emitting red fluorescence were regarded as "with membrane damage", and the ratio of the number of spores with "with membrane damage" to the total number of spores was calculated and used as the degree of cell membrane damage.

The results of Test 2 (1) and (2) are shown in Table 5.

Test 3: Confirmation of effect by outdoor exposure
Preparation test of coated body 2: The same base material used in the evaluation of the coated body by irradiation with light including ultraviolet rays was subjected to the outdoor exposure test shown below.

Test 3 (1) Antifungal test The environment surrounded by forests in the Tokai area was used as the exposure test site. The painted body was installed facing north.

The exposure test was conducted for 3 months.

Confirmation of the effect of the antifungal test To confirm the effect after the exposure test, visually observe the appearance and use a reflection-illuminated microscope (ECLIPSE LV100ND, Nikon) to measure the germination and hyphal elongation of mold spores at a magnification of 340 times. By observing, the degree of hyphal elongation was classified into the following four stages and scored. For each stage, the state of mold growth by microscopic observation is shown in FIGS. 1 to 4.
0: Mold stains are not visible. Moreover, no germination of mold spores was observed by microscopic observation. (Fig. 1)
1: Mold stains are not visible, but microscopic observation shows germination of some spores, but the hyphae are short (tens to hundreds of μm). (Fig. 2)
2: Dirt caused by mold can be visually recognized. According to microscopic observation, germination of spores was observed, and hyphae were partially elongated to several hundred μm or more (Fig. 3).
3: According to microscopic observation, most of the spores were germinated and the hyphae were elongated on one surface (Fig. 4). At the above-mentioned hyphal elongation: 3, the surface of the sample was dull or black due to the growth of mold. Mold stains are also observed by visual observation.

It was judged that 0 points and 1 point had an antifungal effect, and 2 and 3 points had no antifungal effect.

Test 3 (2) Algae control test The environment surrounded by forests in the Tokai area was used as the exposure test site. The painted body was installed facing north.

The exposure test was conducted for 12 months.

Confirmation of the effect of the algae control test The evaluation of the algae control effect after the exposure test was performed by visual observation and scoring based on the following criteria.
0: Algae stains are not visible 1: Algae stains are visible but green change is not confirmed 2: Algae stains are clearly visible and green changes can be confirmed.

It was judged that 0 points and 1 point had an algae-proofing effect, and 2 points had no algae-proofing effect.

Test 3 (3) Evaluation of residual ratio of cerium oxide (water resistance)
The environment surrounded by forests in the Tokai area was used as the exposure test site. The painted body was installed facing north.

The exposure test was conducted for 12 months.

Quantification of cerium oxide Using fluorescent X-ray analysis, cerium oxide contained on the surface of the coated body before and after exposure was quantified. The equipment used and the measurement conditions are described below.
Equipment ZSX PrimusII (manufactured by Rigaku Denki Kogyo Co., Ltd.)
X-ray source Rh (4kW)
Tube voltage-current 50kV-60mA
Attenuator 1/1
No primary X-ray filter Measurement diameter 10 mm
Slit S2
Spectral crystal LiF1
Detector SC
Scan speed 0.12 ° / min (step width-holding time 0.02 ° -10s)
Scan range (2θ) 68.5-74.5 °
PHA 100-300
Atmosphere vacuum

The signal intensity obtained by subtracting the background intensity from the peak intensity of the characteristic X-ray (Lβ1) of the Ce element detected at 2θ = 71.6 ° was taken as the signal intensity indicating the amount of cerium oxide contained in the surface of the coated body.

Background intensity calculation method In the obtained fluorescent X-ray spectrum, the value calculated by substituting 2θ = 71.6 ° in the straight line connecting the detection intensity of 2θ = 68.5 ° and 2θ = 74.5 ° is used as the background intensity. did.

The ratio of the signal intensity attributable to cerium oxide contained in the surface of the coated body after the exposure test divided by the signal intensity before exposure was calculated as the cerium oxide residual ratio.

60% or more was evaluated as passing water resistance, and less than 60% was evaluated as failing water resistance.

Test 3 (4): Evaluation of weather resistance An exposure test was conducted on Miyakojima. The painted body was installed with the surface facing south and an inclination of 20 ° with respect to the horizontal.

The exposure test was conducted for 12 months.

Confirmation of weather resistance effect
JIS K 5600-8-6: 2014 "Chalking grade" was used to evaluate the chalking grade. The tape used in this evaluation was a tape for measuring whitening (Japan Paint Inspection Association), with black paper on the background and an illuminance of 600 lux at the time of evaluation (set by the illuminance meter AR813A manufactured by Taiyo Co., Ltd.). ..
Sensory evaluation: The following criteria were set in comparison with the standard image of the chalking grade described in JIS K 5600-8-6 "Chalking grade".
Chalking grade 1: No change in background Grade 2: Very slightly white Grade 3: Slightly white Grade 4: Clearly white Grade 5: Almost white

Chalking grades 1 to 3 passed and 4 and 5 failed.

The results of Tests 3 (1), (2), (3) and (4) are shown in Table 6. The average particle size of the silica particles was measured in the coated bodies P1, P13, and P14. The results were 22 nm, 15 nm and 12 nm, respectively.

In the examples, hyphal elongation of mold spores was effectively suppressed, black stains derived from mold growth could not be visually recognized, and a good antifungal effect was exhibited. In addition, green stains derived from algae could not be visually recognized, and a good algae-proofing effect was exhibited. Furthermore, it has good durability (water resistance and weather resistance) that suppresses the dissolution of cerium oxide even under the condition of being exposed to rainfall under ultraviolet rays, and also suppresses the chalking due to the decomposition of the painted surface on which the surface layer is formed. Demonstrated.

Claims (12)

A coating body for suppressing the growth of mold and / or algae adhering to the surface.
It has a base material and a surface layer formed on the base material.
The surface layer comprises photocatalytic titanium oxide particles and cerium oxide particles having oxygen deficiency in the fluorite structure.
In the cerium oxide particles, in the Raman spectroscopic spectrum, the peak attributed to the F _2g vibration mode of the Ce—O bond becomes the peak assigned to the _F2g vibration mode of the Ce—O bond obtained by measuring the standard substance. On the other hand, a painted body having a deviation of more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low wavenumber side. The coated body according to claim 1, wherein the surface layer is irradiated with light containing ultraviolet rays, and the coated body is exposed to an environment in which mold spores adhere to the surface thereof. It has the characteristics that the degree of cell membrane damage of mold spores after irradiation with light containing ultraviolet rays is less than 50%, and the ATP value after irradiation with light containing ultraviolet rays is more than 0 RLU / cm ² and less than 500 RLU / cm ² . The coated body according to claim 2, characterized in that. The coated body according to claim 3, wherein the ATP value is less than 300 RLU / cm ² . The coated body according to any one of claims 1 to 4, wherein the surface layer further contains silica particles. The coated body according to any one of claims 1 to 5, wherein the surface layer has a porous structure in which the mold and / or algae do not penetrate through the layer. A coating composition comprising photocatalytic titanium oxide particles and cerium oxide particles having oxygen deficiency in a fluorite structure.
In the cerium oxide particles, in the Raman spectroscopic spectrum, the peak attributed to the F _2g vibration mode of the Ce—O bond becomes the peak assigned to the _F2g vibration mode of the Ce—O bond obtained by measuring the standard substance. On the other hand, a coating composition having a deviation of more than 1.0 cm ^-1 and less than 9.9 cm ^-1 on the low wavenumber side. The coating composition according to claim 7, wherein the surface layer is irradiated with light containing ultraviolet rays, and the coated body is exposed to an environment in which mold spores adhere to the surface thereof. .. The degree of cell membrane damage of mold spores after irradiation with light containing ultraviolet light is less than 50%, and the ATP value after irradiation with light containing ultraviolet light exceeds 0 RLU / cm ² and 500 RLU / cm ² . The coating composition according to claim 8, wherein the coating composition has a property of less than or equal to. The coating composition according to claim 9, wherein the ATP value is less than 300 RLU / cm ² . The coating composition according to any one of claims 7 to 10, further comprising silica particles. The coating composition according to any one of claims 7 to 11, further comprising a dispersion medium.

Images