JP2000129595A - Printing sheet supporting titanium oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sheet usable for a poster, paper wallpaper, etc., having excellent printing preservability, deodorizing ability and weather resistance. SOLUTION: A titanium oxide-supporting printing sheet obtained by providing a substrate with a titanium oxide-containing layer composed of a titanium oxide coating material composition comprising a binder consisting of an inorganic binder selected from a silica sol and an alumina sol and an organic polymer binder, having a blending ratio of titanium oxide to the inorganic binder of 5:1 to 1:5 by weight and a blending ratio of the organic polymer binder to the whole solid content of the coating material composition of 5-30 wt.% is printed with a pattern required to make the total area of a colored printed part <=90% based on the whole area of the titanium oxide-supporting printing sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a support having a titanium oxide coating layer provided on at least one surface of a support, and a required pattern printed with printing ink on the titanium oxide coating layer to form a colored printed portion. The present invention relates to a printing sheet supporting titanium oxide, and more particularly to a printing sheet supporting titanium oxide such as a poster and a paper wallpaper having excellent print storability, deodorizing ability and weather resistance.

[0002]

2. Description of the Related Art With increasing interest in the living environment, there has been an increasing demand for the removal of harmful substances in daily life such as odors, and the development of air purifiers incorporating a device for removing odors has been actively carried out. I have. In these devices, a filter mainly containing activated carbon is used, and a method of adsorbing malodorous substances on activated carbon has been adopted. However,
Activated carbon has an adsorbing effect but has no decomposability, so it becomes saturated when a certain amount of malodorous substance is absorbed, and the filter must be replaced periodically.

In recent years, as a solution to such a problem, a composite material in which activated carbon and a catalyst for decomposing harmful substances are combined has been developed. For example, JP-A-1-234729 describes an air conditioner incorporating a photoreactive semiconductor composite in which titanium oxide is supported on honeycomb activated carbon. In this case, a part of the malodor component to be adsorbed is decomposed by OH radicals generated in the photoreactive semiconductor, so that the adsorption ability of the activated carbon can be maintained for a relatively long time.
However, this method requires activated carbon having a special honeycomb structure in order to support the photoreactive semiconductor and enhance the photoreaction efficiency, and requires a special process for retaining titanium oxide on the surface and inside the honeycomb. Was needed.

[0004] Japanese Patent Application Laid-Open No. 2-252241 describes a photocatalytic device in which a hollow cylindrical honeycomb structure made of a metal oxide catalyst is provided around an ultraviolet irradiation lamp.

Further, a method for removing harmful substances in a gas phase using photocatalytic titanium oxide is disclosed. For example, JP-A-2-253848 describes an ozone decomposition catalyst in which an anatase type titanium oxide is supported on an inorganic fibrous carrier. In Japanese Patent Application Laid-Open No. 3-233100, a mixture of titanium dioxide and activated carbon and a mixture having a wavelength of 300 n
It describes a ventilating facility consisting of a light source that emits light of m or more. JP-A-4-256755 discloses that titanium dioxide can be used as a deodorant and deodorant for home use by supporting it on granular pulp. Further, Kusunaga et al. Performed photodecomposition of organic halogen compounds by holding titanium dioxide on ceramic paper (Journal of the Electrochemical Society, vol. 60, pp. 107, 1).
992).

[0006] The photocatalytic decomposition of gas-phase harmful substances by the photocatalytic titanium oxide includes the approach of the gas-phase harmful substances to the titanium oxide photocatalyst, adsorption, photodecomposition by near-ultraviolet light, and elimination of by-products generated on the titanium oxide photocatalyst surface. It has been confirmed that the process will proceed.

On the other hand, the ability of titanium oxide to decompose harmful substances greatly varies depending on the type of titanium oxide. For example, conventionally, for the purpose of improving whiteness and opacity, titanium oxide has been widely used as an internal pigment for papermaking.The internal titanium oxide for papermaking has a large particle diameter of 0.1 to 0.2 microns. Therefore, the specific surface area was as low as about 10 m ² / g, and it was recognized that the photocatalytic decomposition ability of high-concentration gas-phase harmful substances was low.

Therefore, the present inventor has conducted a detailed investigation on the photocatalytic decomposition ability of internally added titanium oxide powder for papermaking, and
It has been found that, if it is a gas phase harmful substance of m order or less, the titanium oxide powder for papermaking has the ability to decompose gas phase harmful substance efficiently by near-ultraviolet light irradiation.

However, when the internally added titanium oxide for papermaking is coated on a base material such as paper or plastic together with an organic polymer binder such as polyvinyl alcohol or latex, the binder fixes the titanium oxide fine particles to the base material. However, it was confirmed that the gas phase harmful substance could not be adsorbed on the surface of the titanium oxide fine particles, and the photocatalytic decomposition ability was not sufficiently exhibited.

In order to improve the photocatalytic decomposition ability, the average particle diameter is 0.002 to 0.05 μm and the specific surface area is 100 to
Ultrafine titanium oxide of 350 m ² / g has been developed and is being put to practical use. However, ultra-fine titanium oxide has a very high photocatalytic decomposition ability and decomposes organic compounds that come into contact with it, so when coated on a base material such as paper or plastic, together with a binder such as polyvinyl alcohol or latex, Since the binder and the substrate were decomposed in a short time, it was difficult to keep the ultrafine titanium oxide fixed on the substrate.

Further, when printing is performed using a printing ink on a titanium oxide-containing layer obtained by coating ultrafine titanium oxide with a binder such as polyvinyl alcohol or latex on a base material such as paper or plastic. In addition, titanium oxide photodecomposes organic pigments, organic pigments constituting the printing ink, oil in the vehicle, resin, plasticizer, and additives. For this reason, if the printed matter is left in a place exposed to light, a clear color of the printed part fades with time, or a problem occurs in print storability such that the printed part peels off from the titanium oxide-containing layer, The titanium oxide coated sheet was not used as a print medium.

[0012]

SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to provide a titanium oxide-carrying printing sheet such as a poster and paper wallpaper which is excellent in photodegradation ability of odorous substances and the like and storage stability. In more detail, the titanium oxide is arranged in a state where the photocatalytic function is optimally developed, and is not only firmly supported on the support, but also by long-time irradiation with radiation for activating the photocatalytic function. An object of the present invention is to provide a titanium oxide-carrying printing sheet in which the printed portion is clear and the printed portion is not peeled off from the titanium oxide-containing layer.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a titanium oxide supporting sheet having a titanium oxide-containing layer containing titanium oxide and a binder as main components on at least one surface of a support. The agent comprises an inorganic binder selected from silica sol or alumina sol and an organic polymer binder, and the mixing ratio of titanium oxide and the inorganic binder is 5: 1 to 5% by weight.
A titanium oxide-containing layer comprising a titanium oxide coating composition, wherein the mixing ratio of the organic polymer binder is 1: 5, and the total solid content of the coating composition is 5 to 30% by weight, Further, in the titanium oxide-carrying printing sheet in which a required pattern is printed on the titanium oxide-containing layer with a printing ink to form a colored printing section, the total area of the coloring printing section is relative to the total area of the titanium oxide-carrying printing sheet. The problem was solved by providing a titanium oxide-carrying printing sheet that is less than 90%.

Although the mechanism by which the above-mentioned means achieves the object is not clear, it is considered as follows.

In the present invention, titanium oxide is dispersed in water together with a dispersant, and then an inorganic binder selected from silica sol or alumina sol is added as an inorganic binder at a fixed ratio to titanium oxide, and the mixture is added for several hours. Stir. afterwards,
By adding and stirring the organic polymer binder, an aqueous titanium oxide coating composition can be obtained. Next, the titanium oxide-carrying sheet is obtained by applying and drying the aqueous titanium oxide coating composition on a substrate such as paper or plastic. Thereafter, various printing inks are printed on this sheet by a printing method such as letterpress, intaglio, lithographic, stencil, etc., to obtain a target titanium oxide-carrying sheet excellent in print preservability.

In the drying step after the application of the titanium oxide paint, first, silica or alumina composed of ultrafine particles having a particle diameter on the order of millimicrons is fixed to titanium oxide fine particles preferentially. It is formed. Subsequently, it is considered that binding between the titanium oxide composite particles by the organic polymer binder and immobilization to the support occur. Thus, the titanium oxide fine particles form the titanium oxide composite particles with the silica or alumina ultrafine particles, and the titanium oxide composite particles have countless pores through which gas molecules can pass. It can easily reach the surface of the titanium oxide fine particles, and a photolysis reaction occurs. Therefore, it is considered that the titanium oxide fine particles do not come into direct contact with the organic binder and the support, maintain high photocatalytic activity, and do not decompose the binder and the support.

Another reason for the excellent deodorizing ability is that the total area of the colored printed portion is set to 90% or less of the total area of the titanium oxide-carrying printing sheet. If a printing process is performed on the titanium oxide supporting sheet, the printing ink conceals the surface of the titanium oxide-containing layer, so that the amount of transmitted ultraviolet light is reduced and odorous gas molecules are less likely to reach the surface of the titanium oxide fine particles. However, by setting the total area of the colored printing portion to 90% or less of the total area of the titanium oxide-carrying printing sheet, it is possible to exhibit sufficient photocatalytic ability.

Further, the excellent print storability is that, since the outside of the titanium oxide particles is covered with ultrafine particles of silica or alumina, the organic pigment in the printing ink and the resin in the vehicle are directly mixed with the titanium oxide. It is considered that the probability of contact becomes extremely small.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The titanium oxide used in the present invention is a titanium oxide obtained by a method of purifying from a mineral or a method of chemically synthesizing one that can exist alone by interacting with water. Including. Specifically, titanium oxide or hydroxide, which is called hydrous titanium oxide, hydrated titanium oxide, metatitanic acid, orthotitanic acid, and titanium hydroxide, particularly those having many hydroxyl groups on the surface are preferable . The titanium oxide used in the present invention can be produced by the following method. For example, a method (hydrolysis method) of hydrolyzing titanyl sulfate, titanium chloride, an organic titanium compound, and the like, if necessary, in the presence of seeds for nucleation,
A method in which an alkali agent is added to titanyl sulfate, titanium chloride, an organic titanium compound, etc. to neutralize them (neutralization method) while coexisting with seeds for nucleation as necessary. A phase oxidation method (gas phase oxidation method), a method of firing titanium oxide obtained by a hydrolysis method and a neutralization method (a firing method), and the like can be given. In addition, pure titanium oxide particles obtained by chemically modifying the surface of pure titanium oxide may be used as long as the photocatalytic function is activated by appropriate radiation.

One of the important factors for determining the decomposability of harmful substances, which is the object of the present invention, is titanium oxide in the drying step of the titanium oxide-containing paint, titanium oxide composite particles formed from silica sol or alumina sol, and titanium oxide composite particles. There is a delicate bond balance between the titanium oxide composite particles and the organic polymer binder, and the resolving power is improved by more contact of the titanium oxide fine particles with the decomposed material, and therefore, the specific surface area of the titanium oxide tends to be higher. The larger the better. The specific surface area of the titanium oxide according to the present invention can be easily measured with a BET surface area measuring device. However, in consideration of practical resolution, the preferable specific surface area of the fine titanium oxide powder according to the present invention is 10 to 350 m ² / g. It is. Also, most titanium oxides do not have porosity,
It can be simply filled with a small particle size. The preferred X-ray primary particle size of the titanium oxide according to the present invention is 2 to 1
At 50 nm, the particle size of the secondary particles generated by the aggregation of the primary particles is 0.
1-5 microns is desirable. In addition, pure titanium oxide particles obtained by chemically modifying the surface of pure titanium oxide may be used as long as the photocatalytic function is activated by appropriate radiation.

In the present invention, the mixing ratio of titanium oxide and silica sol or alumina sol is one of the important factors that determine the effect of the present invention. That is, the mixing ratio determines the structure and function of the titanium oxide composite particles formed in the drying step. The mixing ratio of titanium oxide to silica sol or alumina sol is 5: 1 to 1: 5 by weight, and more preferably 2: 1 to 1: 2.

The organic polymer binder added to the titanium oxide-containing layer according to the present invention is a thermoplastic polymer emulsion or a water-soluble polymer compound which is a thermoplastic polymer dispersed in water. Specifically, as the thermoplastic polymer emulsion, acrylic resin, styrene-acryl copolymer, styrene-butadiene copolymer, ethylene-
Vinyl acetate copolymer, polypropylene and the like can be used.
Examples of the water-soluble polymer compound include starch, modified starch, polyvinyl alcohol, modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, polyacrylamide, cluster dextrin, chitosan, alginate, cellulose derivatives such as carboxymethylcellulose, and hydroxyethylcellulose. In order to increase the light transmittance, it is preferable that the reflection, scattering and absorption be as small as possible. In that respect, polyvinyl alcohol and polyacrylamide which are completely dissolved in water are preferable.

The proper addition ratio of the organic polymer binder to the mixture of titanium oxide and silica sol or alumina sol is 5 to 30% by weight based on the total solid content of the paint. If it is less than 5%, binding between titanium oxide and titanium oxide composite particles formed from silica sol or alumina sol and immobilization to a support are insufficient. When the content exceeds 30% by weight, the binding power increases, but the transmitting power of the active radiation decreases and the photodecomposition ability decreases.

The radiation which activates the photocatalytic function is usually 40
Near-ultraviolet light of 0 nm or less.

The titanium oxide supporting sheet according to the present invention comprises:
Although a titanium oxide-containing layer is provided on a support, double-sided printing can be performed by providing a titanium oxide-containing layer on both surfaces of the support. If desired, an under layer may be provided between the support and the titanium oxide-containing layer to improve the adhesiveness.

The aqueous titanium oxide coating composition of the present invention can be applied to a support by a method of impregnating with a conventional size press, a gate roll size press, a film transfer type size press, a roll coater, a rod ( Bar) Coating method using a coater such as a coater, a blade coater, a spray coater, an air doctor (knife) coater, and a curtain coater in the same manner as in a general coating process, together with a small amount of other appropriate binder if desired. Is mentioned. In particular, in the impregnation method, the support may be wetted in advance.

The support according to the present invention is not particularly limited as long as it can be coated with the aqueous titanium oxide coating composition of the present invention, but it is mainly composed of paper made of vegetable fibers, mainly synthetic resin fibers, and inorganic bases. Non-woven fabric, woven fabric, synthetic resin film or sheet made of fiber, and the like. As the plant fiber used for the support material according to the present invention, wood such as chemical pulp such as kraft pulp, sulfite pulp, and alkali pulp from softwood and hardwood, semi-chemical pulp, semi-mechanical pulp, and mechanical pulp Fibers, vegetable non-wood fibers such as mulberry, mulberry, straw, kenaf, bamboo, linter, bagasse, and esparto, as well as regenerated fibers such as rayon and processed natural fibers such as cellulose derivative fibers may be used. .

Examples of synthetic resin fibers include olefin resins such as polyethylene and polypropylene, polyester resins such as declon, polyvinyl acetate, ethylene-vinyl acetate copolymer resin, polyamide resins such as nylon, polyacrylonitrile, acrylan, and auron. , Dynel,
And acrylic resin such as berel, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl ether,
Thermoplastic synthetic resin fiber composed of polyvinyl ketone, polyether, polyvinyl alcohol resin, diene resin, polyurethane resin, etc., phenol resin, furan resin, urea resin, melamine resin, aniline resin, unsaturated polyester resin, alkyd resin And thermosetting synthetic resin fibers such as epoxy resin. As inorganic fibers,
Metal fibers such as rock wool, silicone-based fibers, fluorine-based fibers, and stainless steel wool, various glass fibers, and the like. The fiber group used in the present invention may be a single kind or a combination of two or more kinds.

Further, flame retardancy can be imparted by adding a flame retardant to the support. Examples of the flame retardant include guanidine sulfamate, guanidine phosphate, guanidine tetraborate, ammonium sulfamate, ammonium phosphate, melamine phosphate, tetrabromobisphenol A, antimony trioxide, aluminum hydroxide, magnesium hydroxide, and the like. Can be As a method of impregnating the flame retardant, the impregnation may be carried out by a size press in a paper making process, or may be added in advance in a stock preparation step to make a paper.

In processing the above-mentioned plant fiber raw material into a support according to the present invention, rosin and its modified product, if desired,
Emulsions of vegetable wax or maleic anhydride, α-olefin, and styrene / acrylate synthetic resins, sizing agents such as alkyl ketene dimer, alkenyl succinic anhydride and stearic anhydride, starch and modified products thereof, guar gum And denatured products thereof, dextrin, carboxymethylcellulose, polyvinyl alcohol, polyethylene oxide, polyethyleneimine, polyacrylamide, polyamide epichlorohydrin, various emulsions (including latex), urea formalin resin, melamine formalin resin, and other paper strength enhancers and binders. In addition, papermaking may be performed by adding or adding various additives such as a partial retention improver, a surfactant, an antifoaming agent, a dye, a fluorescent whitening agent, an antioxidant, and a slime control agent. For the paper making of the support, a combination paper machine such as a round net paper machine, a fourdrinier paper machine, a Yankee paper machine, a twin wire paper machine, a hybrid former and a top former can be used.

Further, as the plant fiber used for the support according to the present invention, a water-soluble inorganic substance is allowed to act on the plant fiber before forming into a sheet, and the inorganic substance-supporting fiber obtained by insolubilizing the inorganic substance with water is supported. May be used. As a method of insolubilizing and supporting a water-soluble inorganic substance on plant fiber (pulp), JP-A-3-146766, JP-A-3-152295, JP-A-4-18193,
There are methods described in JP-A Nos. 4-24299 and 4-57964 and the like. That is, the hydrophilic fiber material is impregnated with an aqueous solution containing a water-soluble inorganic compound that reacts with a specific gas or aqueous solution to generate a water-insoluble inorganic substance, and then is contacted with a gas or an aqueous solution that makes these inorganic substances water-insoluble. By letting
A water-insoluble inorganic substance can be carried inside the fiber material.

The non-woven fabric used for the support according to the present invention may be a wet method in which the above synthetic resin fibers are suspended in water and formed into a sheet by a papermaking method, a resin bond by resin bonding, a needle punch using crossing with a needle, or the like. The so-called dry method such as stitch bond knitted by yarn or thermal bond bonding by heat, water entanglement method in which high-pressure water is sprayed from a nozzle to entangle the fibers, spun bond to form a sheet while spinning directly, direct spinning In this case, it can be manufactured by a melt blow method or the like in which a sheet is formed while producing fine fibers by applying the principle of spraying. The thickness of the nonwoven fabric,
The porosity, the shape of the void, the degree of porosity, the flexibility, the elasticity, the fluff, the texture, and the like can be adjusted by selecting the above-described production method. Further, in the present invention, since the aqueous treatment is performed, the nonwoven fabric needs to have a certain degree of water wettability, and a web made of hydrophilic fibers is preferable. Further, it is preferable to process the nonwoven fabric by a spun bond or spun lace method from the viewpoint of sheet strength.

[0033]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. The parts by weight described below indicate parts by weight of dry solids.

Example 1 <Preparation of Titanium Oxide Paint Composition> Titanium oxide fine powder for papermaking (trade name: TYPEK W-10, X-ray particle size 150 nm,
100 parts by weight of Ishihara Sangyo Co., Ltd.) and 2 parts by weight of sodium polycarboxylate (trade name: ARON T-40, manufactured by Toagosei Co., Ltd.) were mixed with water, and the mixture was stirred at high speed for 1 hour with a lab mixer to disperse fine titanium oxide powder. Next, 160 parts by weight of silica sol (trade name: Snowtex ST-40, manufactured by Nissan Chemical Industries, Ltd.) was added to this dispersion, followed by high-speed stirring for 1 hour to prepare a titanium oxide / silica sol dispersion having a solid content of 20% by weight. Furthermore, as an organic polymer binder in this titanium oxide / silica sol dispersion,
46 parts by weight of starch were added, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / silica sol was 15% by weight.

<Preparation of titanium oxide supporting sheet>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Titanium Oxide-Supported Printed Sheet> On the above-described titanium oxide-supported sheet, dry solid was dried using four-color offset inks (Leo Echo Yellow, Magenta, Cyan, Black, Toyo Ink Manufacturing Co., Ltd.) 1g per minute
m ² , so that the total area of the colored printed portion is 90% of the total area of the titanium oxide-carrying printing sheet (40 × 30 cm),
Sheet-fed offset printing was performed to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-supported printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was lowered.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . After 1.5 hours, the gas concentration in the chamber was measured with a gas chromatograph equipped with an FID detector.
And the photocatalytic decomposition rate was 90%. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Furthermore, the UV intensity on the surface of the printing sheet supporting titanium oxide is 2.
Ultraviolet irradiation was performed using a 20 W black light for 1.5 hours so as to obtain 5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined to be 90%. No decrease in the photocatalytic decomposition rate due to the repetition was observed.

<Discoloration of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> When the above-mentioned ultraviolet irradiation was repeated 10 times, the fading of the ink on the printing sheet supporting titanium oxide was examined. As a result, there was almost no fading. When a cellophane tape was adhered to the surface of the colored print portion and peeled off, no adhesion of the printing ink to the cellophane tape was observed.

Example 2 <Preparation of Titanium Oxide Paint Composition> 100 parts by weight of titanium oxide fine powder (trade name: ST-01, X-ray particle size 7 nm, manufactured by Ishihara Sangyo) and sodium polycarboxylate (trade name) : Aaron T-4
0, manufactured by Toa Gosei Co., Ltd.) was mixed with water, and the mixture was stirred at high speed with a laboratory mixer for 1 hour to disperse the fine titanium oxide powder. Next, silica sol (trade name: Snowtex ST-4)
160 parts by weight (Nissan Chemical Co., Ltd.) was added to this dispersion and stirred at high speed for 1 hour to prepare a titanium oxide / silica sol dispersion having a solid content of 20% by weight. Further, 46 parts by weight of polyvinyl alcohol as an organic polymer binder was added to the titanium oxide / silica sol dispersion, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / silica sol was 15% by weight.

<Preparation of titanium oxide supporting sheet>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Printed Titanium Oxide-Supported Sheet> On the above-described titanium oxide-supported sheet, four offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 80% of the entire area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-supported printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was checked.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector, and was 1 ppm.
And the photocatalytic decomposition rate was 95%. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Furthermore, the UV intensity on the surface of the printing sheet supporting titanium oxide is 2.
Ultraviolet irradiation was performed using a 20 W black light for 1.5 hours so as to obtain 5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined to be 95%. No decrease in the photocatalytic decomposition rate due to the repetition was observed.

<Discoloration Test of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> The fading of the ink on the titanium oxide-supporting printing sheet obtained by repeating the above-mentioned ultraviolet irradiation 10 times was almost no fading. When a cellophane tape was adhered to the surface of the colored print portion and peeled off, no adhesion of the printing ink to the cellophane tape was observed.

Example 3 <Preparation of Titanium Oxide Coating Composition> Titanium oxide fine powder (trade name: FINNTI ST-150, X-ray particle size 2 nm,
100 parts by weight of KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: Alon T-40, manufactured by Toagosei Co., Ltd.) were mixed with water, and the mixture was stirred at a high speed for 1 hour with a laboratory mixer to disperse fine titanium oxide powder. Next, 160 parts by weight of silica sol (trade name: Snowtex ST-O, manufactured by Nissan Chemical Industries, Ltd.) was added to this dispersion, followed by high-speed stirring for 1 hour to prepare a titanium oxide / silica sol dispersion having a solid content of 20% by weight. Further, 14 parts by weight of silicon-modified polyvinyl alcohol was added to the titanium oxide / silica sol dispersion as an organic polymer binder, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / silica sol was 5% by weight.

<Preparation of sheet supporting titanium oxide>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Printed Titanium Oxide-Supported Sheet> On the above-described titanium oxide-supported sheet, four offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 70% of the total area, to obtain a titanium oxide-carrying printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-supported printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was adjusted to
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector, and was 1 ppm.
And the photocatalytic decomposition rate was 95%. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Furthermore, the UV intensity on the surface of the printing sheet supporting titanium oxide is 2.
Ultraviolet irradiation was performed using a 20 W black light for 1.5 hours so as to obtain 5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined to be 95%. No decrease in the photocatalytic decomposition rate due to the repetition was observed.

<Test of Discoloration of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> When the above-mentioned ultraviolet irradiation was repeated 10 times, the fading of the ink on the printing sheet supporting titanium oxide was examined. As a result, there was almost no fading. When a cellophane tape was adhered to the surface of the colored print portion and peeled off, no adhesion of the printing ink to the cellophane tape was observed.

Example 4 <Preparation of Titanium Oxide Paint Composition> Titanium oxide fine powder (trade name: FINNTI ST-150, X-ray particle size 2 nm,
100 parts by weight of KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: ARON T-40, manufactured by Toagosei Co., Ltd.) were mixed with water, and the mixture was stirred at a high speed with a laboratory mixer for 1 hour to disperse fine titanium oxide powder. Next, 160 parts by weight of alumina sol (trade name: alumina sol 520, manufactured by Nissan Chemical Industries, Ltd.) was added to the dispersion, and the mixture was stirred at a high speed for 1 hour to prepare a titanium oxide / alumina sol dispersion having a solid content of 20% by weight. Further, 111.4 parts by weight of a modified starch (trade name: Cluster-Dextrin, manufactured by Ezaki Glico) was added to the titanium oxide / alumina sol dispersion as an organic polymer binder, and the mixture was stirred slowly for 30 minutes without foaming. A titanium oxide coating composition was prepared. At this time, the blending ratio of the organic polymer binder to the titanium oxide / alumina sol was 30% by weight.

<Preparation of Titanium Oxide-Supported Sheet> The coating amount of the above-mentioned titanium oxide coating composition coating solution after drying on a transparent PET film having a thickness of 50 μm using a Mayer bar is 8 g / m ² . It was applied and dried as described above to produce a titanium oxide supporting sheet.

<Preparation of Titanium Oxide-Supported Printing Sheet> On the above-described titanium oxide-supporting sheet, four color offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 50% of the entire area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> The printed sheet supporting titanium oxide (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was checked.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector.
And the photocatalytic decomposition rate was 100%. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm.
Furthermore, the UV intensity on the surface of the titanium oxide-supported printing sheet
Ultraviolet irradiation was performed using a 20 W black light for 1.5 hours so as to obtain 2.5 mW / cm ² . 10 for this test
The average photocatalytic decomposition rate was determined 100 times, and it was 100%. No decrease in the photocatalytic decomposition rate due to the repetition was observed.

<Discoloration of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> When the above-mentioned ultraviolet irradiation was repeated 10 times, the discoloration of the ink on the titanium oxide-supporting printing sheet was examined, and almost no fading was observed. When a cellophane tape was adhered to the surface of the colored print portion and peeled off, no adhesion of the printing ink to the cellophane tape was observed.

Example 5 <Preparation of titanium oxide coating composition> Fine powder of titanium oxide (trade name: FINNTI ST-150, X-ray particle size: 2 nm,
100 parts by weight of KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: Alon T-40, manufactured by Toagosei Co., Ltd.) were mixed with water, and the mixture was stirred at a high speed for 1 hour with a laboratory mixer to disperse fine titanium oxide powder. Next, 160 parts by weight of alumina sol (trade name: alumina sol 520, manufactured by Nissan Chemical Industries, Ltd.) was added to the dispersion, and the mixture was stirred at a high speed for 1 hour to prepare a titanium oxide / alumina sol dispersion having a solid content of 20% by weight. Further, 46 parts by weight of polyacrylamide as an organic polymer binder was added to the titanium oxide / alumina sol dispersion, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / alumina sol was 15% by weight.

<Preparation of Titanium Oxide-Supported Sheet> A nonwoven fabric was prepared in advance by the following method. 40 parts by weight of polyethylene terephthalate fiber with a fineness of 0.15 denier (fiber diameter 4 microns) and a fiber length of 7.5 mm and a fineness of 1.5 denier (fiber diameter 1
2.4 microns) and 60 parts by weight of a polyester-based flame-retardant fiber having a fiber length of 15 mm were put into water together with a surfactant, and the mixture was vigorously stirred with a pulper until the fiber bundle disappeared. After dilution with water, an aqueous polymer polyacrylamide solution was added while gently stirring with an agitator to increase the viscosity, and stirring was continued to obtain a uniformly dispersed fiber slurry. Using this slurry, a non-woven fabric was obtained by making a papermaking machine using a circular paper machine so that the basis weight was 80 g / m ² . The titanium oxide coating composition coating solution was applied onto the nonwoven fabric using a Meyer bar so that the applied amount after drying was 8 g / m ² , and dried to prepare a titanium oxide supporting sheet.

<Preparation of Titanium Oxide-Supported Printing Sheet> On the above-described titanium oxide-supporting sheet, four color offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 60% of the total area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-supported printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was adjusted to
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector, and was 1 ppm.
And the photocatalytic decomposition rate was 95%. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Furthermore, the UV intensity on the surface of the printing sheet supporting titanium oxide is 2.
Ultraviolet irradiation was performed using a 20 W black light for 1.5 hours so as to obtain 5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined to be 95%. No decrease in the photocatalytic decomposition rate due to the repetition was observed.

<Discoloration of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> When the above-described ultraviolet irradiation was repeated 10 times, the discoloration of the ink on the titanium oxide-supporting printing sheet was examined, and almost no fading was observed. When a cellophane tape was adhered to the surface of the colored print portion and peeled off, no adhesion of the printing ink to the cellophane tape was observed.

Comparative Example 1 <Preparation of Titanium Oxide Paint Composition> Titanium oxide fine powder (trade name: FINNTI ST-150, X-ray particle size 2 nm,
100 parts by weight of KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: Alon T-40, manufactured by Toagosei Co., Ltd.) were mixed with water, and the mixture was stirred at a high speed for 1 hour with a laboratory mixer to disperse fine titanium oxide powder. Next, silica sol (trade name: Snow-
160 parts by weight (Tex ST-40, manufactured by Nissan Chemical Industries, Ltd.) was added to this dispersion, and the mixture was stirred at high speed for 1 hour to prepare a titanium oxide / silica sol dispersion having a solid content of 20% by weight. Further, 5.2 parts by weight of polyvinyl alcohol as an organic polymer binder was added to the titanium oxide / silica sol dispersion, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / silica sol was 2% by weight.

<Preparation of titanium oxide supporting sheet>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Titanium Oxide-Supported Printing Sheet> On the above-described titanium oxide-supporting sheet, four color offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 90% of the entire area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-supported printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was adjusted to a value of 40%.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector.
And the photocatalytic decomposition rate was slightly reduced at 85%. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Further, UV irradiation was performed using a 20 W black light for 1.5 hours so that the UV intensity on the surface of the titanium oxide-carrying printing sheet became 2.5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined.
It was 80%, and a decrease in the photocatalytic decomposition rate was observed upon repetition.

<Discoloration of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> When the above-described ultraviolet irradiation was repeated 10 times, the discoloration of the ink on the titanium oxide-supporting printing sheet was examined. As a result, considerable fading was observed. In addition, a cellophane tape was stuck to the surface of the colored printed portion and peeled off, and the printing ink layer was peeled off together with the titanium oxide layer and adhered to the cellophane tape.

Comparative Example 2 <Preparation of Titanium Oxide Paint Composition> Titanium oxide fine powder (trade name: FINNTI ST-150, X-ray particle size 2 nm,
100 parts by weight (manufactured by KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: Alon T-40, Toa Gosei) were mixed with water, and the mixture was stirred at a high speed for 1 hour with a laboratory mixer to disperse fine titanium oxide powder. Next, 160 parts by weight of silica sol (trade name: Sno-Tex ST-30, manufactured by Nissan Chemical Industries, Ltd.) was added to the dispersion, and the mixture was stirred at a high speed for 1 hour to prepare a titanium oxide / silica sol dispersion having a solid content of 20% by weight. . Further, 143.1 parts by weight of polyvinyl alcohol as an organic polymer binder was added to the titanium oxide / silica sol dispersion, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / silica sol was 35.3% by weight.

<Preparation of titanium oxide supporting sheet>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Titanium Oxide-Supported Printed Sheet> On the above-described titanium oxide-supported sheet, four color offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 90% of the entire area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-supported printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was checked.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector, and was found to be 7 ppm.
And the photocatalytic decomposition rate was significantly reduced at 65%. Further, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Further, UV irradiation was performed using a 20 W black light for 1.5 hours so that the UV intensity on the surface of the titanium oxide-carrying printing sheet became 2.5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined.
It was 50%, and a considerable decrease in the photocatalytic decomposition rate was observed upon repetition.

<Discoloration of Ink of Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> The fading of the ink of the titanium oxide-supported printing sheet obtained by repeating the above-described ultraviolet irradiation 10 times was examined, and a little fading was observed. In addition, when a cellophane tape was stuck to the surface of the colored printing section and peeled off, a little adhesion of the printing ink to the cellophane tape was recognized.

Comparative Example 3 <Preparation of Titanium Oxide Paint Composition> Titanium oxide fine powder (trade name: FINNTI ST-150, X-ray particle size 2 nm,
100 parts by weight (manufactured by KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: Alon T-40, Toa Gosei) were mixed with water, and the mixture was stirred at a high speed for 1 hour with a laboratory mixer to disperse fine titanium oxide powder. Next, 160 parts by weight of silica sol (trade name: Snowtex ST-O, manufactured by Nissan Chemical Industries, Ltd.) was added to this dispersion, followed by high-speed stirring for 1 hour to prepare a titanium oxide / silica sol dispersion having a solid content of 20% by weight. Further, 46 parts by weight of a silicon-modified polyvinyl alcohol as an organic polymer binder was added to the titanium oxide / silica sol dispersion, and the mixture was stirred slowly for 30 minutes without foaming to prepare a titanium oxide coating composition. At this time, the blending ratio of the organic polymer binder to the titanium oxide / silica sol was 15% by weight.

<Preparation of a sheet supporting titanium oxide>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Printed Sheet Supporting Titanium Oxide> On the above-described titanium oxide supported sheet, four offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Using a black ink, Toyo Ink Mfg. Co., Ltd., dry solid content of 1 g / m ² , titanium oxide supported printing sheet (40 × 30c
m) Sheet-fed offset printing was performed so that the total area of the colored printing portion was 95% of the entire area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-carrying printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was reduced.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector, and was found to be 7 ppm.
The photocatalytic decomposition rate was 55%, and a considerable decrease in the photocatalytic function was observed. Furthermore, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Further, UV irradiation was performed using a 20 W black light for 1.5 hours so that the UV intensity on the surface of the titanium oxide-carrying printing sheet became 2.5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined to be 55%. No decrease in the photocatalytic decomposition rate due to the repetition was observed.

<Fade of Ink on Titanium Oxide-Supported Printing Sheet and Ink Peeling Test> The fading of the ink on the titanium oxide-supported printing sheet obtained by repeating the above-described ultraviolet irradiation 10 times was almost no fading. When a cellophane tape was adhered to the surface of the colored print portion and peeled off, no adhesion of the printing ink to the cellophane tape was observed.

Comparative Example 4 <Preparation of Titanium Oxide Paint Composition> Titanium oxide fine powder (trade name: FINNTI ST-150, X-ray particle size: 2 nm,
100 parts by weight of KEMIRA) and 2 parts by weight of sodium polycarboxylate (trade name: Alon T-40, manufactured by Toagosei Co., Ltd.) were mixed with water, and the mixture was stirred at a high speed for 1 hour with a laboratory mixer to disperse fine titanium oxide powder. Next, as an organic polymer binder, 14 parts by weight of silicon-modified polyvinyl alcohol was added to the titanium oxide dispersion, and slowly added so as not to form bubbles.
After stirring for a minute, a titanium oxide coating composition was prepared.

<Preparation of a sheet supporting titanium oxide>
g / m ² of high-quality paper, the coating amount of the above-mentioned titanium oxide coating composition after drying was 8 g / m ² using a Mayer bar.
And dried to produce a titanium oxide supporting sheet.

<Preparation of Titanium Oxide-Supported Printed Sheet> On the above-described titanium oxide-supported sheet, four color offset inks (trade names: Leo Echo Yellow, Magenta, Cyan,
Ink, manufactured by Toyo Ink Mfg. Co., Ltd.), dry solid content is 1 g / m ² , titanium oxide supported printing sheet (40 × 30 cm)
Sheet-fed offset printing was performed so that the total area of the colored printing portion was 90% of the entire area, to obtain a titanium oxide-supported printing sheet having a size of 40 × 30 cm.

<Confirmation Test of Photocatalytic Effect> This titanium oxide-carrying printing sheet (40 × 30 cm) was placed in a 200-liter glass closed chamber, and the concentration in the chamber was reduced.
Saturated formaldehyde gas was injected with a micro syringe so as to have a concentration of 20 ppm. Further, UV irradiation was performed using a 20 W black light so that the UV intensity on the surface of the titanium oxide-carrying printing sheet was 2.5 mW / cm ² . The gas concentration in the chamber after 1.5 hours was measured with a gas chromatograph equipped with an FID detector, and was 5 ppm.
And the photocatalytic decomposition rate was 65%. Further, the titanium oxide-carrying printed sheet sample after the above test was put back into a 200-liter glass closed chamber again, and saturated formaldehyde gas was injected with a micro syringe so that the concentration in the chamber became 20 ppm. Furthermore, the UV intensity on the surface of the printing sheet supporting titanium oxide is 2.
Ultraviolet irradiation was performed using a 20 W black light for 1.5 hours so as to obtain 5 mW / cm ² . This test was repeated 10 times, and the average photocatalytic decomposition rate was determined to be 65%, indicating a decrease in the photocatalytic decomposition rate due to the repetition.

<Discoloration Test of Ink on Titanium Oxide-Supported Printed Sheet and Peeling Test of Ink> The discoloration of the ink on the titanium oxide-supported print sheet obtained by repeating the above-described ultraviolet irradiation 10 times was examined, and the colored print portion was completely decolorized. Was. In addition, when a cellophane tape was stuck to the surface of the erased printed portion and peeled off, an extremely large amount of titanium oxide powder adhered to the cellophane tape.

[0079]

The effects of the present invention include the following. 1) Since the total area of the colored printing portion is set to 90% or less of the total area of the titanium oxide-carrying printing sheet, there is almost no decrease in the titanium oxide photocatalytic function due to the shielding of the printing ink, and the deodorizing ability is maintained for a long time. An excellent printed sheet supporting titanium oxide is obtained. 2) Since the titanium oxide composite particles in the titanium oxide-containing layer do not decompose the organic pigment in the printing ink and the resin in the vehicle, the printing is clear forever, and the printed part does not peel off from the titanium oxide coating layer and the print storability. Thus, a titanium oxide-supported printing sheet excellent in quality can be obtained. 3) Due to the above effects, it can be used as a poster and paper wallpaper, which are print media for the purpose of antibacterial and deodorizing indoor space.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4C080 AA07 BB02 CC01 JJ06 JJ09 KK08 MM02 NN03 NN06 NN24 NN25 NN27 NN28 QQ03 4L031 AA00 DA12 DA13 DA16 4L055 AG18 AG19 AG47 AG48 AG64 AG72 AG86 AH02 AH37 AA17A17A50A GA23 GA44

Claims (2)

[Claims] 1. A titanium oxide supporting sheet having a titanium oxide-containing layer containing titanium oxide and a binder as main components on at least one surface of a support, wherein the binder is selected from silica sol and alumina sol. A binder and an organic polymer binder, wherein the compounding ratio of titanium oxide and the inorganic binder is 5: 1 to 1: 5 by weight, and the compounding ratio of the organic polymer binder Is 5 to 30 with respect to the total solid content of the coating composition.
A titanium oxide-containing layer made of a titanium oxide coating composition having a weight percentage of 0.1% by weight, and further, a required pattern is printed on the titanium oxide-containing layer with a printing ink to form a colored printed portion. The total area of the colored printing section is 90 with respect to the total area of the titanium oxide supporting printing sheet.
% Or less. 2. The printed sheet supporting titanium oxide according to claim 1, wherein the support is a flame-retardant paper.