JP2007146041A - Solvent-based coating material containing visible light-reactive photocatalyst and laminate structure using the same and freezing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating material for forming a photocatalyst layer, for example, when a photocatalyst layer is formed on the surface of a door or the surface of an outer casing of a freezing device such as a refrigerator installed in a room, staining is prevented by easily decomposing attached oils, fingerprint or the like; and to provide a laminate structure using the coating material, and the refrigerator having the photocatalytic layer formed at least on a part of the surface of the door or the surface of the outer casing by using the laminate structure. <P>SOLUTION: The laminate structure 1 has the photocatalytic layer 3 laminated on a base material 11 or on a design resin layer 2 formed on the surface of the base material 11 by using a solvent-based coating material obtained by formulating an effective amount of a visible light-reactive photocatalyst in an organic solvent containing a fluorine-based resin. The refrigerator 20 is constituted by using the laminated structure 1 so that the photocatalytic layer 3 may face to the exterior to which the visible light is supplied and may be formed at least on a part of the outer casing 24, the door 27, and the front plates 28, 29 and 30 of doors of drawers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solvent-type paint containing a visible light reaction type photocatalyst, a laminated structure and a refrigeration apparatus using the same.

  A technique for imparting antifouling property and oil repellency by coating a fluorine-based resin on the surface of a substrate such as a steel plate is known. However, the adhesion of dirt such as oil can be reduced by coating the fluorine resin, but the fluorine resin itself does not have a self-cleaning action, so it adheres to the surface of the substrate coated with the fluorine resin. It is necessary to wipe off the dirt. In addition, since the fluororesin coat has a low affinity for oils, when oil adheres to the surface, it floats on the surface, and there is a problem that the appearance deteriorates compared to the case of general paint coats other than the fluororesin coat. It was.

  Oils and fingerprints adhere to the surface of doors and outer boxes of refrigerators and other refrigeration equipment and become dirty, so a thin film of photocatalyst such as titanium oxide is formed on these surfaces, and the organic matter is decomposed by the action of the photocatalyst. Many proposals have been made to prevent surface contamination.

  However, in the case of the photocatalyst coat, although there is an effect of decomposing oil, since the affinity for the oil is large, the oil adheres firmly to the photocatalyst coat, making it difficult to decompose the oil by the action of the photocatalyst. There was a problem.

  Therefore, it has been proposed to coat a fluorine-based resin on the surface of a substrate such as a steel plate, and to form a photocatalytic thin film such as titanium oxide thereon, but the photocatalyst layer covers the fluorine-based resin coat, There was a problem that the functions such as antifouling property and oil repellency of the fluorine-based resin coat were not exhibited.

  In addition, conventionally used photocatalysts such as anatase-type titanium oxide exhibit excellent photocatalytic activity by absorbing light of a specific wavelength in the ultraviolet region (wavelength shorter than about 380 nm). Because it exerts the action of oxidizing and decomposing organic substances etc. by the strong oxidizing action derived from it, when using this effect indoors etc., the amount of ultraviolet rays is very small, so UV lamps and UV LEDs etc. The special light source used was necessary.

FIG. 4 shows an example of a cross section of a conventional laminated structure in which a photocatalyst layer is formed on the outermost layer using a photocatalyst (see, for example, Patent Document 1).
A conventional laminated structure 10 is formed by adhering a design resin layer 12 in which pigments or dyes are blended on the surface of a base material 11 such as a steel plate or a character or a pattern is formed. An intermediate layer 14 made of a material that is not affected by the photocatalytic action to which fillers 13 such as metal particles and oxide fine particles that are not affected by the oxidation action of the photocatalyst are added is formed, and an inorganic system is formed on the intermediate layer 14. The photocatalyst layer 15 is formed by coating by spraying a dispersion liquid in which photocatalyst fine particles are dispersed in a binder or the like.

The intermediate layer 14 is for preventing the design resin layer 12 from being deteriorated by a strong oxidizing action derived from the photocatalytic action exhibited by absorbing the ultraviolet rays irradiated to the photocatalytic layer 15.
However, when the intermediate layer 14 is formed, the design resin layer 12 can be prevented from being deteriorated, but the design resin layer 12 is covered with the intermediate layer 14, so that various characteristics such as design properties of the design resin layer 12 are lost. In addition, there is a problem that costs increase due to an increase in man-hours.

On the other hand, a visible light reaction type photocatalyst that exhibits excellent photocatalytic activity even in the visible light region has been proposed. For example, by nitrogen doping using an RF sputtering method (see Patent Document 2), by doping a transition metal element (Cr, V, Fe, etc.) into titanium dioxide using ion implantation (see Patent Document 3), from the surface One obtained by reducing a semiconductor containing a cation therein (see Patent Document 4), a solution containing titanium alkoxide, a rare earth element compound, and an organic solvent is hydrolyzed, and the resulting sol is 300 A titanium oxide doped with a rare earth element (see Patent Document 5) obtained by heat treatment at a temperature not lower than ° C. has been proposed.
Japanese Patent Laid-Open No. 2001-199001 JP 2001-205094 A Japanese Patent Laid-Open No. 9-262482 JP 2000-237598 A JP 2005-74376 A

The first object of the present invention is to solve the conventional problems, and it is not necessary to cover the design resin layer 12 with the intermediate layer 14 as in the prior art, and it is excellent even when used indoors where the amount of ultraviolet rays is very small. For example, if a photocatalyst layer is formed on the surface of the door or outer box of a refrigeration apparatus such as a refrigerator installed in a room, a special light source such as an ultraviolet lamp or an ultraviolet LED may not be installed. In addition to providing a coating material for forming a photocatalyst layer having anti-staining properties and oil repellency as well as having a self-cleaning effect that can easily decompose oils and fingerprints attached to prevent contamination. ,
The second object of the present invention is a laminated structure in which a photocatalyst layer is formed using the paint, and various secondary products such as an air conditioner, a washing machine, a microwave oven, an air purifier, a cleaner, and a refrigerator can be made. Is to provide an inexpensive laminated structure,
A third object of the present invention is to provide an inexpensive refrigeration apparatus such as a refrigerator in which a photocatalyst layer is formed on at least a part of the door surface or the outer box surface using the laminated structure.

  The invention according to claim 1 of the present invention for solving the above problems is a solvent type containing a visible light reaction type photocatalyst, characterized in that an effective amount of a visible light reaction type photocatalyst is blended in an organic solvent containing a fluorine resin. It is a paint.

  The invention according to claim 2 of the present invention is characterized in that the solvent-type paint according to claim 1 contains 1 to 20% by mass of the visible light reactive photocatalyst.

  Invention of Claim 3 of this invention uses the solvent-type coating material of Claim 1 or Claim 2 on the layer which consists of a base material, and the design resin layer formed in the base-material surface or the base-material surface. A laminated structure in which the formed photocatalyst layer is laminated.

  According to a fourth aspect of the present invention, the laminated structure according to the third aspect is used so that the photocatalyst layer is formed on at least a part of the outer box and the door so as to face the outside to which visible light is supplied. It is the freezing apparatus characterized by comprising.

The invention according to claim 1 of the present invention is a solvent-based paint containing a visible light reactive photocatalyst, characterized in that an effective amount of the visible light reactive photocatalyst is blended in an organic solvent containing a fluorine resin,
Forms a photocatalyst layer on the base resin surface, the design resin layer formed on the base material surface by a known coating method, or the surface of various secondary products such as refrigerators. The formed photocatalyst layer exhibits excellent photocatalytic activity in the visible light region even if it is used indoors where the amount of ultraviolet rays is very small. For example, the door surface of a refrigerator such as a refrigerator installed indoors If a photocatalyst layer is formed on the surface of the outer box, self-cleaning can be easily decomposed to prevent contamination without attaching special light sources such as UV lamps and UV LEDs, and by attaching oils and fingerprints. In addition to having an effect, there is a remarkable effect that even when a design resin layer is provided as in the prior art, it does not have to be covered with an intermediate layer and is excellent in antifouling property and oil repellency.

The invention according to claim 2 of the present invention is the solvent-type paint according to claim 1, characterized in that the visible light reactive photocatalyst is contained in an amount of 1 to 20% by mass,
Since the blending amount of the visible light reaction type photocatalyst is within a specific range, it is possible to surely exhibit excellent photocatalytic activity and to reliably decompose oils and fingerprints attached to prevent contamination, thereby further prominent effect. Play.

Invention of Claim 3 of this invention uses the solvent-type coating material of Claim 1 or Claim 2 on the layer which consists of a base material, and the design resin layer formed in the base-material surface or the base-material surface. A laminated structure characterized in that the formed photocatalytic layer is laminated,
Using this laminated structure, various secondary products such as air conditioners, washing machines, microwave ovens, air purifiers, cleaners and refrigerators can be made and assembled, and the laminated structure itself and secondary products However, even if it is installed in a room where the amount of ultraviolet rays is very small, the special photocatalytic activity of the photocatalyst layer formed on the surface of the secondary product can be used to avoid installing a special light source such as an ultraviolet lamp or ultraviolet LED. However, it has a self-cleaning effect that can easily prevent oils and fingerprints from adhering to prevent contamination, and even if a design resin layer is provided as in the past, it does not have to be covered with an intermediate layer, and is also antifouling. It has a remarkable effect that it has excellent properties and oil repellency.

According to a fourth aspect of the present invention, the laminated structure according to the third aspect is used so that the photocatalyst layer is formed on at least a part of the outer box and the door so as to face the outside to which visible light is supplied. It is a refrigeration apparatus characterized by comprising,
Even if it is installed in a room where the amount of ultraviolet rays is very small, the photocatalytic activity of the photocatalyst layer formed on its surface makes it possible to adhere without installing a special light source such as an ultraviolet lamp or ultraviolet LED. In addition to having a self-cleaning effect that can easily decompose oils and fingerprints and prevent contamination, it is not necessary to cover with an intermediate layer even when a design resin layer is provided as in the past, as well as antifouling and oil repellency It has a remarkable effect that it is also excellent.

FIG. 1 is an explanatory view illustrating a cross-sectional form of an example of a laminated structure of the present invention.
FIG. 2 is an explanatory view illustrating a cross-sectional form of another example of the laminated structure of the present invention.
As shown in FIG. 1, the laminated structure 1 of the present invention is a design resin in which pigments or dyes are blended on the surface of a substrate 11 such as a steel plate using a known method, or a character or pattern is formed. The layer 2 is formed in close contact, and is coated and coated by a known method using a solvent-type paint containing a predetermined amount of a visible light reaction type photocatalyst 4 and a fluororesin 5 on the design resin layer 2. After that, the photocatalyst layer 3 formed by removing the solvent by drying or the like is laminated.

  As shown in FIG. 2, another laminated structure 1 (A) of the present invention is a solvent-type paint containing a predetermined amount of a visible light reactive photocatalyst 4 and a binder resin 5 on the surface of a substrate 11 such as a steel plate. The photocatalyst layer 3 is formed by laminating and coating by a publicly known method and then drying to remove the solvent.

  Even if the laminated structures 1 and 1 (A) of the present invention are installed in a room where the amount of ultraviolet rays is extremely small, the visible light reactive photocatalyst 4 in the photocatalyst layer 3 exhibits excellent photocatalytic activity even in the visible light region. Oils and fingerprints adhering to the surface can be easily decomposed to prevent contamination, and have an excellent self-cleaning effect, and also have excellent antifouling properties and oil repellency due to the effect of the fluororesin.

FIG. 3 shows a refrigerator 1 formed on the outer surface of the outer box and the outer surface of the door so that the photocatalyst layer 3 faces the outside to which visible light is supplied using the laminated structure 1, 1 (A) of the present invention. It is explanatory drawing explaining the form of the cross section of an example.
In FIG. 3, 20 is a household refrigerator. The refrigerator 20 for home use is arranged in the order of the refrigerator compartment R (refrigeration temperature zone area), the vegetable compartment refrigerator compartment V (refrigeration temperature zone area), and the freezer compartment (refrigeration temperature zone area) F from the top. The refrigerator 20 has a refrigeration cycle including at least a compressor, a condenser, and an evaporator. The refrigeration evaporator 21 for cooling the refrigeration temperature zone and the refrigeration temperature zone area cooling of the evaporator (eva). It has two refrigeration evaporators 22 and is called a 2-eva type.

A plurality of shelves 23 are provided in the cabinet so that an object to be cooled can be stored.
Reference numeral 24 denotes an outer box, reference numeral 25 denotes an inner box, and reference numeral 26 denotes a heat insulating material filled with foam between the two (24, 25).

  Reference numeral 27 denotes a revolving door that can be freely opened and closed for the refrigerator compartment provided on the front surface of the household refrigerator 20, and opens and closes around a rotating shaft provided on one side. 28 is a drawer door front plate of the vegetable compartment refrigerator compartment V, and 29 and 30 are drawer door front plates of the freezer compartment F. 31 is an air path for circulating the air in the refrigerator, and 34 is an air path for circulating the air in the freezer compartment. A refrigerator 32 for the refrigerator compartment and a fan 32 for circulating the air in the refrigerator are installed in the air passage 31, and the fan 22 for circulating the air in the freezer compartment 22 and the air in the freezer compartment in the air passage 34. 33 is installed, the cool air cooled by the evaporator 21 through the air passage 31 is discharged to the refrigerating chamber through the fan 32, and the cool air cooled by the evaporator 22 through the air passage 34 is discharged to the fan. It is made to discharge to the freezer compartment through 33.

  And the top of the outer box 24 and both side surfaces (not shown) of the home refrigerator 20 of the present invention, the outer surface of the rotary door 27, the outer surface of the drawer door front plate 28 of the vegetable compartment refrigerator compartment V, and the drawer door of the freezer compartment F The photocatalyst layer 3 is visible on the outer surfaces of the face plate 29 and the drawer door front plate 30 using the laminated structure 1 of the present invention shown in FIG. 1 or the laminated structure 1 (A) of the present invention shown in FIG. It is formed so as to face the outside to which light is supplied.

  The home refrigerator 20 of the present invention does not include a special light source using an ultraviolet lamp, an ultraviolet LED, or the like, and is installed in a room where the amount of ultraviolet rays is very small, for example, the top surface of the outer box 24 and not shown. Photocatalyst layer 3 formed on the outer surfaces of both sides, the outer surface of the rotary door 27, the outer surface of the drawer door front plate 28 of the vegetable compartment refrigerator compartment V, the drawer door front plate 29 and the drawer door front plate 30 of the freezer compartment F In addition to having a self-cleaning effect that can easily decompose oils and fingerprints adhering to these surfaces by using the excellent photocatalytic activity and prevent contamination, antifouling and oil repellency is achieved by the effect of fluororesin Etc. When the laminated structure 1 of the present invention shown in FIG. 1 is used, the design resin layer 2 does not deteriorate, so that various characteristics such as design can be maintained.

As the visible light reaction type photocatalyst used in the present invention, the known visible light reaction type photocatalyst as described above can be used.
It is also possible to replace a part of the visible light reaction type photocatalyst with one selected from activated carbon, silica gel, zeolite and the like.

  Specifically, the fluororesin used in the present invention is, for example, tetrafluoroethylene / hexafluoropropylene copolymer (FEP resin), tetrafluoroethylene / perfluoroalkoxy copolymer (PFA resin), ethylene / Examples thereof include a tetrafluoroethylene copolymer (ETFE resin), a polytetrafluoroethylene polymer (PTFE resin), or a combination thereof. Among them, when a photocatalyst layer is formed, a fluororesin having a high visible light transmittance in the region of about 400 to 800 nm and excellent in transparency can be preferably used.

When the solvent-based paint of the present invention contains 1 to 20% by mass of a visible light reaction type photocatalyst, it is preferable because it can reliably exhibit excellent photocatalytic activity and reliably decompose attached oils and fingerprints to prevent contamination. .
If the blending amount is less than 1% by mass, there is a possibility that the excellent photocatalytic activity cannot be exerted reliably. If it exceeds 20% by mass, the photocatalytic activity is too strong and the deterioration of the design resin layer 2 may not be suppressed or prevented. However, neither is preferable.

The organic solvent used in the present invention is preferably a solvent that can well disperse or dissolve the fluorine-based resin. Specifically, for example, hydrocarbon solvents such as toluene and xylene, ethyl acetate, butyl acetate, butyl cellulose acetate, and the like. Ester solvents, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone, alcohol solvents such as methanol, ethanol and butanol, solves such as ketones and butyl cellulose acetate, combinations of these two or more Can be mentioned.
Although the usage-amount of an organic solvent is not specifically limited, For example, the example using 50-30 mass parts of said fluororesins can be given with respect to 50-70 mass parts of organic solvents.

  Other additives can be blended with the solvent-type paint of the present invention as long as the photocatalytic activity of the photocatalyst of the photocatalyst layer is not impaired. Specific examples of other additives include additives that are generally known as additives for paints, such as surface conditioners, emulsifiers, dispersants, and thickeners.

Specific examples of the material of the substrate used in the present invention include, for example, metals such as steel, aluminum, stainless steel, titanium, and various alloys, inorganic materials such as glass and ceramics, various wooden materials, and various plastics. Can do. The shape and form of the base material may be plate-like or corrugated-like, or any of those formed according to the shape and form of various secondary products such as doors, outer boxes, drawer door front plates, etc. It is not limited.
As an example of a steel plate, the steel plate by which surface treatments, such as pickling, phosphoric acid processing, and blasting, were given beforehand on the surface can be mentioned, for example.
These may be coated with a primer such as polyester, epoxy, or urethane on the surface as necessary to form a cured film having a thickness of about 0.5 to 30 μm.

  In order to form the photocatalyst layer using the solvent-type paint of the present invention on the substrate surface or the design resin layer formed on the substrate surface, for example, dip coating, brush coating, roll coating, air spray, airless spray Ordinarily known methods such as electrostatic spraying and shower coating can be used.

  The description of the above embodiment is for explaining the present invention, and does not limit the invention described in the claims or reduce the scope thereof. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the examples.

Example 1
A design resin layer is provided on the refrigerator door surface (material: SUS430, steel plate with a plate thickness of 0.45 mm), and a photocatalyst layer is formed thereon using a solvent-type paint of the present invention having the following composition by a known coating method. did.
Composition: transparent resin by mass; thermosetting fluorine-modified polyester resin 25
Visible light reactive photocatalyst; Nitrogen doped photocatalyst 5
Organic solvent; butyl cellulose acetate / isopolone 20/50
Dispersant; amino acid dispersant 0.05
The photocatalyst layer on the refrigerator door surface was excellent in antifouling property and oil repellency, and reduced the adhesion of dirt such as oil. When installed in a room and used for a long time, fingerprints and the like adhered to the photocatalyst layer on the door surface, but they were decomposed by the photocatalytic activity.
Regarding the occurrence of deterioration such as choking in the transparent resin of the photocatalyst layer and the resin of the design resin layer, compared to the case of using a thermosetting polyester resin instead of using a thermosetting fluorine-modified polyester resin as the transparent resin When a thermosetting fluorine-modified polyester resin was used, deterioration hardly occurred and the choking generation time was about 5 times longer.

  The solvent-based paint of the present invention is excellent in storability, paintability and economy, and is applied to various secondary materials such as refrigerators and the like on a substrate surface or a design resin layer formed on the substrate surface by a known coating method. A photocatalyst layer can be formed on the product surface, and the formed photocatalyst layer shows excellent photocatalytic activity in the visible light region even if it is used indoors where the amount of ultraviolet rays is very low. If a photocatalyst layer is formed on the surface of the door or outer box of a refrigeration system such as a refrigerator, the attached oils and fingerprints can be easily decomposed without installing a special light source such as an ultraviolet lamp or ultraviolet LED. In addition to having an excellent self-cleaning effect, it does not need to be covered with an intermediate layer even when a design resin layer is provided as in the past, and it is also excellent in antifouling properties and oil repellency. , Remarkable Since an effect, high utility value on the industry.

It is explanatory drawing which shows the form of the cross section of one example of the laminated structure of this invention. It is explanatory drawing which shows the form of the cross section of the other example of the laminated structure of this invention. It is explanatory drawing which shows the form of the cross section of one example of the refrigerator of this invention. It is explanatory drawing which shows the form of the cross section of the conventional laminated structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 (A) Laminated structure 2 Design resin layer 3 Photocatalyst layer 4 Visible light reaction type photocatalyst 5 Fluorine resin 11 Base material 20 Home refrigerator 24 Outer box 27 Revolving door 28 Drawer door front plate of vegetable compartment refrigerator compartment V 29, 30 Drawer door front plate of freezer compartment F

Claims (4)

  A solvent-based paint containing a visible light reactive photocatalyst, wherein an effective amount of a visible light reactive photocatalyst is blended in an organic solvent containing a fluororesin.   The solvent-type paint according to claim 1, wherein the solvent contains 1 to 20% by mass of the visible light reaction type photocatalyst.   A layer composed of a substrate and a photocatalyst layer formed using the solvent-based paint according to claim 1 are laminated on the substrate surface or a design resin layer formed on the substrate surface. A laminated structure characterized by that.   A refrigeration apparatus using the laminated structure according to claim 3, wherein the photocatalyst layer is formed on at least a part of the outer box and the door so as to face the outside to which visible light is supplied.

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