JP2007144864A - Laminated structure and refrigeration unit using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated structure in which a photocatalyst layer is formed to easily decompose adherent oils, fingerprints, etc., to prevent the structure from being stained, for example the photocatalyst layer is formed on the surface of the door or the case of a refrigeration unit such as a refrigerator set in a room, and the refrigerator in which the photocatalyst layer is formed in at least one part of the surface of the door or the outer case by using the laminated structure. <P>SOLUTION: In the laminated structure 1, on a design resin layer 2 formed on the surface of a substrate 11, the photocatalyst layer 3 formed by using a solvent type coating containing prescribed amounts of a visual light-reactive photocatalyst 4 and a binder resin 5 is laminated. The concentration of the photocatalyst 4 in the photocatalyst layer 3 is increased gradually toward the outer surface of the layer 3. In the laminated structure, at least 80 mass% of the photocatalyst 4 exists in an outer surface side region occupying 50% of the thickness of the photocatalyst layer 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laminated structure and a refrigeration apparatus using the same, and more particularly to a laminated structure in which a photocatalyst layer including a visible light reaction type photocatalyst is laminated and a refrigeration apparatus using the same.

  Oils and fingerprints adhere to the surfaces of refrigeration equipment doors and outer boxes such as refrigerators 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, conventional 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), and strong oxidation derived from this photocatalytic action. Because it exerts the action of oxidizing and decomposing organic substances, etc., when using this effect indoors etc., the amount of ultraviolet rays is very small, so a special light source using ultraviolet lamps, ultraviolet LEDs, etc. 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, a photocatalyst layer is formed on the surface of the door or outer box of a refrigerator such as a refrigerator installed without using a special light source using an ultraviolet lamp or ultraviolet LED. If so, it is a laminated structure with a photocatalyst layer that has a self-cleaning effect that can easily prevent oils and fingerprints from adhering to prevent contamination, and includes an air conditioner, a washing machine, a microwave oven, and an air purifier. Providing an inexpensive laminated structure that can produce various secondary products such as cleaners and refrigerators,
The second 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 described in claim 1 of the present invention for solving the above-mentioned problems is that a predetermined amount of a visible light reaction type photocatalyst and a binder resin are formed on the substrate surface or on the design resin layer formed on the substrate surface. And a photocatalyst layer formed by using a solvent-based paint containing the photocatalyst layer, wherein the photocatalyst layer is inclined so that the concentration of the visible light reactive photocatalyst increases toward the outer surface. The laminated structure is characterized in that 80% by mass or more of the total visible light reaction type photocatalyst amount is present in an outer surface side region of 50% of the thickness of the photocatalyst layer.

  The invention according to claim 2 of the present invention is characterized in that, in the laminated structure according to claim 1, 3 to 40% by mass of the visible light reactive photocatalyst is contained in the photocatalyst layer.

  According to a third aspect of the present invention, the laminated structure according to the first or second aspect is used and 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. This is a refrigeration apparatus configured as described above.

  According to a fourth aspect of the present invention, in the refrigeration apparatus according to the third aspect, the thickness of the photocatalyst layer is 5 μm or less.

The invention according to claim 1 of the present invention uses a solvent-based paint containing a predetermined amount of a visible light reaction type photocatalyst and a binder resin on the surface of the substrate or on the design resin layer formed on the surface of the substrate. The photocatalyst layer formed in a layered structure, wherein the photocatalyst layer is inclined so that the concentration of the visible light reactive photocatalyst in the photocatalyst layer increases toward the outer surface, A laminated structure characterized in that 80% by mass or more of the total visible light reaction type photocatalyst amount is present in an outer surface side region of 50% of the thickness of the layer,
For example, using a plurality of solvent-based paints from low to high concentration of visible light reaction type photocatalyst, using a low concentration to a high concentration sequentially, multiple times on the surface of the substrate or by using a known coating method It is applied to the surface of the design resin layer formed on the surface or the surface of various secondary products such as refrigerators, so that the concentration of the visible light reactive photocatalyst in the photocatalyst layer increases toward the outer surface. The amount of visible light reaction type photocatalyst used can be minimized, and the design resin layer does not have to be covered with an intermediate layer as in the prior art. The 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, indoors without using a special light source such as an ultraviolet lamp or ultraviolet LED. Installation If a photocatalyst layer is formed on the surface of the door or outer box of a freezer such as a refrigerator, it has a self-cleaning effect that can easily decompose and prevent contamination by adhering oils and fingerprints. Even when the layer is formed, the deterioration can be prevented and suppressed, so that a remarkable effect that various characteristics such as design properties can be maintained is obtained.
Using this laminated structure, various secondary products such as air conditioners, washing machines, microwave ovens, air purifiers, cleaners, refrigerators, etc. can be made and assembled, and the remarkable effect is that they are inexpensive. Play.

The invention according to claim 2 of the present invention is characterized in that, in the laminated structure according to claim 1, 3 to 40% by mass of the visible light reactive photocatalyst is contained in the photocatalyst layer,
Since the blending amount is within a specific range, it is possible to reliably exhibit excellent photocatalytic activity, and to reliably decompose oils and fingerprints attached to prevent contamination, thereby producing a further remarkable effect.

According to a third aspect of the present invention, the laminated structure according to the first or second aspect is used and 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 being configured,
Even if it is installed in a room with a very small amount of ultraviolet rays without installing a special light source such as an ultraviolet lamp or ultraviolet LED, it adheres using the excellent photocatalytic activity of the photocatalyst layer formed on the surface. In addition to having a self-cleaning effect that can easily decompose oils and fingerprints to prevent contamination, and even when a design resin layer is formed, its deterioration can be prevented and suppressed, so various characteristics such as design can be maintained. Moreover, it has a remarkable effect of being inexpensive.

The invention according to claim 4 of the present invention is the refrigeration apparatus according to claim 3, wherein the photocatalyst layer has a thickness of 5 μm or less,
Even if the thickness of the photocatalyst layer is 5 μm or less, the photocatalyst layer is inclined so that the concentration of the visible light reaction type photocatalyst increases toward the outer surface, and the photocatalyst layer has a thickness of 50 % Of the total surface light reactive photocatalyst amount is 80% by mass or more in the outer surface side region, so that a further remarkable effect of exhibiting excellent photocatalytic activity even in the visible light region is exhibited.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
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 a solvent-type paint containing a predetermined amount of visible light reaction type photocatalyst 4 and binder resin 5 is used on the design resin layer 2 by a known method, for example, as described above. The photocatalyst layer 3 is formed by laminating and coating a plurality of times and then drying to remove the solvent.

  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 the solvent by removing the solvent by, for example, coating and coating a plurality of times as described above, and then drying.

  It is configured such that 80% by mass or more of the total visible light reaction type photocatalyst amount is present in the outer surface side region of 50% (XX) of the thickness of any photocatalyst layer 3. The method of forming the photocatalyst layer 3 that is configured to be inclined so that the concentration of the visible light reaction type photocatalyst 4 in the photocatalyst layer 3 increases toward the outer surface is not limited to the above-described method. For example, when the solvent is volatilized and evaporated upwards by performing coating and coating at one time and then drying, etc. without removing and coating, the solvent is volatilized and evaporated. The photocatalyst layer 3 may be formed by inclining so that the concentration of the visible light reaction type photocatalyst 4 in the photocatalyst layer 3 increases toward the outer surface so that the fine particles of the visible light reaction type photocatalyst 4 move upward. Is possible.

  When 80% by mass or more of the total visible light reaction type photocatalyst amount is present in the outer surface side region of 50% (XX) of the thickness of the photocatalyst layer 3, as shown in FIGS. 4 is present in a large amount in a shallow region on the outer surface side, and some of them protrude outward from the outer surface, so that it exhibits excellent photocatalytic activity in the visible light region.

  When the amount of the visible light reaction type photocatalyst existing in the outer surface side region of 50% (XX) of the thickness of the photocatalyst layer 3 is less than 80% by mass of the total visible light reaction type photocatalyst amount, The visible light reactive photocatalyst 4 present in the shallow region is reduced, and some of the outer surface protrudes to the outside. This is not preferable because there is a possibility that excellent photocatalytic activity may not be exhibited in the visible light region.

  The photocatalyst layer 3 is formed by coating and coating at one time, and then drying and removing the solvent so that the concentration of the visible light reactive photocatalyst 4 in the photocatalyst layer 3 increases toward the outer surface. For example, the surface tension of the binder resin 5 is reduced, and for example, a fluorine-based resin having a surface tension of 30 dyn / cm or less is used as the binder resin. Further, in consideration of the surface tension of the binder resin 5 and the particle size and apparent specific gravity of the visible light reaction type photocatalyst 4, the fine particles of the visible light reaction type photocatalyst 4 become upward as the solvent volatilizes and evaporates. It is preferable to select a condition that facilitates movement.

Since the laminated structures 1 and 1 (A) of the present invention are configured to be inclined so that the concentration of the visible light reactive photocatalyst 4 in the photocatalyst layer 3 increases toward the outer surface, the visible light to be used is used. The amount of reactive photocatalyst 4 can be minimized, and even if it is installed in a room where the amount of ultraviolet light is very small, it exhibits excellent photocatalytic activity in the visible light region. In addition to having a self-cleaning effect that can easily prevent oils and fingerprints adhering to the surface without contamination by installing a simple light source and preventing contamination, the design resin layer 2 can be prevented and suppressed from being deteriorated. The characteristics can be maintained.
In the laminated structure 1 of the present invention, since the deterioration of the design resin layer 2 is suppressed and prevented even if the design resin layer 2 is not covered with an intermediate layer as in the prior art, the number of steps is not increased and the cost is low.
In the laminated structure 1 (A) of the present invention, since the design resin layer 2 is not provided, the number of steps is not increased and the cost is lower.

FIG. 3 shows a refrigerator 1 formed on the outer surface of the outer box and the outer surface of the door using the laminated structure 1 or 1 (A) of the present invention so that the photocatalyst layer 3 faces the outside to which visible light is supplied. 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 prevent oils and fingerprints adhering to these surfaces by using their excellent photocatalytic activity to prevent contamination, the design resin layer (not shown) does not deteriorate, so the design etc. The various characteristics of 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.

The binder resin used in the present invention may be a thermoplastic resin, a thermosetting resin, or a combination thereof. Preferably, when a photocatalyst layer is formed, the visible light transmittance in the region of about 400 to 800 nm is high, for example 50%. The resin is such that the photocatalyst of the photocatalyst layer exhibits excellent photocatalytic activity by visible light.
Specific examples of the binder resin used in the present invention include acrylic resins, epoxy resins, polyester resins, silyl group-containing vinyl copolymers, silicon resins, and fluorine resins having a low surface tension. Can do.

When the visible light reaction type photocatalyst used in the present invention is contained in the photocatalyst layer 3 in an amount of 3 to 40% by mass, the photocatalytic activity is surely exhibited, and the attached oils and fingerprints are reliably decomposed and contaminated. Since it can prevent, it is preferable.
If it is less than 3% by mass, there is a possibility that the excellent photocatalytic activity cannot be surely exhibited. If it exceeds 40% by mass, the photocatalytic activity is too strong, and the design resin layer 2 may not be prevented from being deteriorated or prevented. Neither is preferred.

Specific examples of the organic solvent used in the present invention include hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate, butyl acetate, and butyl cellulose acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone. Ketone solvents such as methanol, ethanol solvents such as ethanol, butanol, etc., ketones and solvesso such as butyl cellulose acetate, and combinations of two or more thereof.
Although the usage-amount of an organic solvent is not specifically limited, For example, the example which uses the said transparent resin 50-30 mass parts with respect to 50-70 mass parts of organic solvents can be given.

  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 the other additive include additives commonly known as paint additives such as surface conditioners, 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 was provided on a coated steel plate having a thickness of 0.45 mm in the outer box of the refrigerator, and a photocatalyst layer having a thickness of 4 μm was formed thereon using the solvent-based paint of the present invention having the following composition.
Composition: transparent resin by mass; thermosetting polyester resin 25
Visible light reactive photocatalyst; Nitrogen doped photocatalyst 5
Volatile organic solvent; butyl cellulose acetate / isopolone 20/50
Dispersant; amino acid dispersant 0.05
80% by mass or more of the total visible light reaction type photocatalyst amount could be inclinedly arranged in the outer surface side region of 50% (XX) of the thickness of the photocatalyst layer.
When this refrigerator was installed indoors and used for a long period of time, fingerprints and oil adhered to the photocatalyst layer on the outer box surface, but they were decomposed by the photocatalytic activity. Compared to the case where the all visible light reaction type photocatalyst is uniformly arranged in the photocatalyst layer, the fingerprint and oil decomposition effect increased by 20 mass%. However, deterioration such as choking did not occur in the transparent resin of the photocatalyst layer and the resin of the design resin layer.

  In the laminated structure of the present invention, the photocatalyst layer is formed so that the concentration of the visible light reaction type photocatalyst in the photocatalyst layer increases toward the outer surface, and the photocatalyst layer has a thickness of 50. % Of the total visible light reactive photocatalyst amount is 80% by mass or more in the outer surface side region, so that the amount of visible light reactive photocatalyst used can be minimized, and this design resin layer can be used as an intermediate layer as before. In addition, the photocatalyst layer formed can be used indoors where the amount of ultraviolet rays is very low, or exhibits excellent photocatalytic activity in the visible light region. For example, if a photocatalyst layer is formed on the door surface or outer box surface of a refrigerator such as a refrigerator installed in a room without using a light source, the oils and fingerprints that are attached can be easily decomposed and contaminated. Self-cleaning effect that can be prevented To top, prevent its degradation even when the design resin layer is formed, it is possible to suppress that can maintain various properties such as design, since a marked effect, a high industrial value.

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 Binder resin 11 Base material 20 Domestic refrigerator 24 Outer box 27 Revolving door 28 Drawer door front plate 29 of the vegetable compartment refrigerator compartment V , 30 Drawer door front plate of freezer compartment refrigerator compartment F

Claims (4)

  A photocatalyst layer formed by using a solvent-type paint containing a predetermined amount of a visible light reaction type photocatalyst and a binder resin is laminated on the base material surface or a design resin layer formed on the base material surface. The laminated structure is configured to be inclined so that the concentration of the visible light reaction type photocatalyst in the photocatalyst layer increases toward the outer surface, and the outer surface side is 50% of the thickness of the photocatalyst layer. A laminated structure comprising 80% by mass or more of the total visible light reaction type photocatalyst amount in the region.   The laminated structure according to claim 1, wherein the photocatalyst layer contains 3 to 40% by mass of the visible light reaction type photocatalyst.   The laminated structure according to claim 1 or 2, wherein the photocatalyst layer is formed on at least one part of the outer box and the door so as to face the outside to which visible light is supplied. Refrigeration equipment.   The refrigeration apparatus according to claim 3, wherein the photocatalyst layer has a thickness of 5 μm or less.

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