JP2002002766A - Lid of heating container having anti-fogging properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lid of a heating container having anti-fogging properties which can prevent fogging and attachment of water drips and is excellent in visibility of a foodstuff in the container. SOLUTION: A hydrophilic coat is formed on at least an internal surface of the lid of a heating container, wherein the hydrophilic coat has a fine composite uneven structure comprising hydrophilic metal oxide particles having the most frequent value of particle diameters in a range of 3 to 40 nm, hydrophilic metal oxide particles having the most frequent value of particle diameters in a range of 40 to 300 nm and a hydrophilic inorganic amorphous material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid for a heating container used for storing foods to be sold and sold in a warm state such as oden in a display state, or for a pot during cooking, and a method for preventing fogging thereof.

[0002]

2. Description of the Related Art Oden and other foods are stored in a heated container in order to buy and sell them in a warm state. At that time, for example, a wooden lid is used for the purpose of suppressing evaporation of water. However, with a wooden lid, the food is not visible from the outside. Therefore, if the lid is made transparent, the food inside the lid can be stored in a display state, which is convenient. In addition, the lid is kept for the purpose of keeping warm even during cooking such as hot pots, but if the lid is transparent, the food inside the container is easy to see and it is convenient.

[0003]

However, if the lid is simply made transparent, the inside of the lid becomes cloudy due to the condensation of steam, so that the food inside the container is difficult to see clearly from the outside. Even when the condensation of steam further progresses and fine condensed water droplets fuse with each other and grow into large water droplets, the perspective image is distorted by the interface between the water droplet and the transparent lid and the refraction of light at the water droplet and the interface, so the inside of the container is also Food is difficult to see.

On the other hand, several techniques for anti-fog treatment of transparent substrates such as glass and mirror have been known for a long time. For example,
Applying a conductive coating to the surface of a transparent substrate and applying a current to the coating to dry the attached water droplets, or coating the surface of the transparent substrate with a hygroscopic polymer to absorb the attached water droplets into the film And a method in which a water-repellent coating having fine irregularities is formed on the surface of a transparent base material to improve the water-repellent performance by a fractal effect, and to attach water droplets.

However, in the case of a method in which a conductive coating is applied to the surface of a transparent substrate, and the coating is energized to dry the attached water droplets, the above coating is not applied to the inner surface of the lid of the heating vessel. Since a considerable amount of steam is trapped inside, accidents such as short circuits are likely to occur, which is dangerous. In addition, when the above-mentioned coating is applied to the outer surface of the heating vessel lid, the material of the ordinary heating vessel lid such as glass or transparent acrylic is made of a heat insulating material, so that there is much waste in energy consumption and a sufficient anti-fog effect. Can not be obtained.

In the method of coating the surface of a transparent base material with a hygroscopic polymer and absorbing attached water droplets in the coating, a large amount of water vapor is trapped in the container in the case of a heating container lid.
The coating is immediately saturated, and the anti-fogging effect cannot be sufficiently obtained.

Further, even in a method in which a water-repellent film having fine irregularities is formed on the surface of a transparent substrate to improve the water-repellent performance by a fractal effect and water droplets adhere to the surface, in practice, a part of the water-repellent film is partially contained in the container. Water droplets remain. In addition, the adhesion of the coating to the substrate is not sufficient, and there is a practical problem in abrasion resistance. Therefore, in the present invention, even if a large amount of water vapor stays in the container,
An object of the present invention is to provide a lid for a heating container which can prevent fogging and adhesion of water droplets, has excellent visibility of food inside the container, and has practical durability.

[0008]

According to the present invention, there is provided:
In order to solve the above-mentioned problems, a transparent hydrophilic coating is formed on at least the inner surface of the transparent heating container lid substrate, and the hydrophilic coating has at least hydrophilic metal oxide particles and hydrophilic inorganic non-coating. The hydrophilic film has a surface roughness of 5 nm in an arbitrary 5 μm square region.
The cross-sectional curve in the same region is not less than 30 nm and includes a relatively smooth portion and a protruding portion as compared with the smooth portion, and a line segment is set only in the relatively smooth portion. Rz indicated by the cross-sectional curve at that line segment
(Ten-point average roughness) and Sm (average interval of unevenness) are 10n
When a line segment is formed so that m ≦ Rz ≦ 40 nm and 10 nm ≦ Sm ≦ 300 nm, and a line segment is set so as to pass through the protruding portion, Rz indicated by a cross-sectional curve of the line segment
(Ten-point average roughness) and Sm (average interval of unevenness) are 40n
300 nm ≦ Sm ≦ 1500 n for m ≦ Rz ≦ 200 nm
Provided is a lid for a heating container having antifogging property, which has a fine composite uneven structure composed of m unevenness. When the surface roughness, Rz, and Sm are in the above ranges, the antifogging effect due to the improvement in wettability, the high water film maintaining ability, and the transparency can be exhibited. Further, by containing the hydrophilic inorganic amorphous substance, the coating strength is improved and the wear resistance is improved.

In a preferred embodiment of the lid for a heating container according to the present invention, the hydrophilic coating comprises hydrophilic metal oxide particles having a mode of particle diameter of 3 to 40 nm, preferably 10 to 30 nm, and 40 to 40 nm. 300 nm, preferably 40-100
The hydrophilic metal oxide particles having the mode of the particle diameter in nm and the hydrophilic inorganic amorphous substance are contained. By doing so, it is possible to easily form the fine composite uneven structure, and it is possible to exhibit an anti-fogging effect due to an improvement in wettability, a high ability to maintain a water film, and transparency. Further, by containing the hydrophilic inorganic amorphous substance, the coating strength is improved and the abrasion resistance is improved.

Further, in the present invention, 3 to 40 nm,
Preferably, hydrophilic metal oxide particles having a mode of particle diameter of 10 to 30 nm and 40 to 300 nm, preferably 40 to 300 nm.
Provided is an antifogging coating composition for a heating container lid, comprising: a hydrophilic metal oxide particle having a mode of a particle size of from 100 nm to 100 nm; and a hydrophilic inorganic amorphous substance.
The above composition is capable of easily forming the fine composite uneven structure simply by coating on the lid surface of the heating container lid and, if necessary, by heating and curing. The ability to maintain the film and the transparency can be exhibited. Further, by containing the hydrophilic inorganic amorphous substance, the coating strength is improved and the wear resistance is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to FIG. FIG. 1 is a conceptual cross-sectional view of a hydrophilic coating of a transparent heating container lid according to the present invention.

In the lid of the heating container of the present invention, a hydrophilic film is formed on the surface of a transparent substrate. The hydrophilic coating contains at least hydrophilic metal oxide particles and a hydrophilic inorganic amorphous substance. The surface roughness of the hydrophilic film is such that the surface roughness in an arbitrary 5 μm square area on the film is 5 nm.
30 nm or less, and a cross-sectional curve in the same region includes a relatively smooth portion and a protruding portion as compared with the smooth portion, and a line segment is set only in the relatively smooth portion. Rz (ten-point average roughness) and Sm (average interval of unevenness) indicated by a cross-sectional curve of the line segment are 10 nm ≦ Rz
≦ 40 nm, consisting of irregularities of 10 nm ≦ Sm ≦ 300 nm, and setting a line segment so as to pass through the raised portion,
Rz (ten-point average roughness) indicated by the cross-sectional curve at that line segment
And Sm (average interval of unevenness) are 40 nm ≦ Rz ≦ 200
It has a fine composite uneven structure composed of unevenness of 300 nm ≦ Sm ≦ 1500 nm in nm.

Here, the surface roughness, the ten-point average roughness (Rz), and the average interval of unevenness (Sm) in the present invention are measured using an atomic force microscope. The measuring method is to measure the surface shape of 5 μm × 5 μm at an arbitrary point of the coating,
Arithmetic mean roughness (Ra) specified in IS B 0601
The average roughness is expressed by the surface roughness obtained by expanding the surface. Rz and Sm set a line segment in the measured area,
JIS B 06 using the cross-sectional curve at the line segment
Rz and Sm are calculated in the same manner as in the method specified in No. 01. However, the length of the line segment set at this time is not particularly defined, but is set to be as long as possible in consideration of variation in Rz.

When the surface roughness of the hydrophilic film formed on the surface of the substrate is 5 nm or more, the water adhering to the surface spreads and the antifogging function is exhibited without water film breakage.
When the thickness is 30 nm or less, the transparency of the coating film is sufficiently ensured.

Further, Rz (ten-point average roughness) and Sm (average interval of unevenness) indicated by the cross-sectional curve are 10 nm ≦ Rz ≦ 4.
A smooth portion having irregularities of 10 nm ≦ Sm ≦ 300 nm at 0 nm and 300 nm ≦ S at 40 nm ≦ Rz ≦ 200 nm
By having a fine composite concavo-convex structure having both raised portions composed of irregularities of m ≦ 1500 nm, the coating surface has sufficient hydrophilicity due to its fractal effect in the smooth portion, and the water film is formed in the raised portion. Since a sufficient thickness can be ensured, the attached water droplets easily spread quickly in the form of a water film.

The hydrophilic coating in the present invention may be formed by using hydrophilic metal oxide fine particles and a hydrophilic inorganic amorphous substance, although other components may be added. In the present invention, it is necessary that water adhering to the surface is easily wetted and spread, and it is necessary to maintain the water film. In order to stably exhibit the hydrophilicity required for forming the water film for a long period of time, an inorganic substance is required. Is appropriate. At this time, in order to quickly form a water film, a stable substance exhibiting as high a hydrophilicity as possible is appropriate. However, as such a substance, a substance which easily generates chemically adsorbed water on its surface, that is, a hydrophilic substance Among inorganic substances, those whose surface is hydratable can be suitably used. In inorganic substances, oxides form chemically adsorbed water on the surface and exhibit hydrophilicity, but in addition, nitrides, borides, carbides, etc. also cover the surface layer with an oxide film or hydrolyze, It is generally known and can be used to form a chemically adsorbed water layer and exhibit hydrophilicity. Among these, SiO ₂ , Al ₂ O ₃ , ZrO ₂ , and Ti are easily available hydrophilic metal oxide particles exhibiting a high degree of hydrophilicity.
O ₂ and SnO ₂ are preferred. Since TiO ₂ can decompose water to generate active oxygen species and decompose organic substances, an excellent antifouling effect can be expected. SiO ₂ is a colloidal silica, Al ₂ O ₃ is an alumina sol, ZrO ₂ is a zirconia sol, TiO ₂ is a titania sol, and SnO ₂ is a tin oxide sol. At this time, water or alcohol can be used as the solvent, but an aqueous dispersion is particularly preferable in view of hydrophilicity and safety.
The shape of the particles is not limited, and may be spherical, rectangular, flat, feathered, chain-like, or the like, but is preferably spherical or rectangular for ease of forming the uneven structure.

In the present invention, the hydrophilic inorganic amorphous material is an alkali silicate, borosilicate, alkali zirconium salt,
Preferably, at least one of the phosphates is used. These substances are preferable because they can easily form a chemically adsorbed water layer due to the presence of water, and can exhibit hydrophilicity for a long period of time. Available alkali silicates include at least one of sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. In general, it is said that the adhesiveness is stronger in the order of sodium silicate and potassium silicate, and the water resistance is stronger in the order of ammonium silicate and lithium silicate. It is.

It is preferable that the hydrophilic film of the present invention contains boric acid and / or a boric acid compound because the water resistance and the chemical durability can be improved. Examples of boric acid or boric acid compounds include orthoboric acid, metaboric acid, tetraboric acid, zinc borate, potassium borate, sodium borate, barium borate, magnesium borate, lithium borate, and other borate esters. However, the present invention is not limited to these.

Further, it is preferable that the hydrophilic film of the present invention contains phosphoric acid and / or a phosphoric acid compound since the curing of the film can be promoted and the durability of the film can be improved. Phosphoric acid or phosphoric acid compounds include phosphoric anhydride,
Metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphate, tetraphosphate, zinc phosphate, zinc hydrogen phosphate, aluminum phosphate, aluminum hydrogen phosphate, ammonium phosphate,
Examples include, but are not limited to, ammonium hydrogen phosphate, sodium ammonium hydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, calcium phosphate, calcium hydrogen phosphate, sodium phosphate, lithium hydrogen phosphate, and other phosphate esters. Not something.

The hydrophilic film of the present invention contains a precursor of a substance which becomes ZrO ₂ by heat treatment,
Zr is taken into the SiO ₂ structure in the alkali silicate, which is preferable because chemical durability can be improved. As precursors of the substance which becomes ZrO ₂ by heat treatment, zirconium chloride, zirconium oxychloride,
Examples include, but are not limited to, zirconium chloride, zirconium nitrate, zirconium acetylacetonate, zirconium butoxide, zirconium propoxide and the like.

Further, an antibacterial material can be added to the hydrophilic film of the present invention as needed to impart antibacterial properties. Examples include, but are not limited to, metal materials such as Ag and Cu, or compounds thereof, and photocatalytic materials such as TiO ₂ .

In the hydrophilic coating of the present invention, two or more kinds of hydrophilic metal oxide particles different in the mode of the particle diameter can be used in order to form irregularities. By doing so, the fine composite uneven structure can be easily realized. That is, 3
A hydrophilic metal oxide particle having a mode of the particle size in the range of ４０40 nm and a hydrophilic metal oxide particle having a mode of the particle size in the range of 40 to 300 nm are used. Among them, the hydrophilic metal oxide particles having a mode of the particle size in the range of 3 to 40 nm form a large number of fine irregularities on the surface, form a highly transparent irregular film, and wet the water with fine irregularities. By improving the property, it is possible to easily form a water film on the surface. When the mode of the particle diameter is 3 nm or more, the effect of increasing the surface roughness is sufficiently exhibited. When the mode value of the particle diameter is 40 nm or less, it is possible to sufficiently exhibit an increase in the actual surface area with respect to the surface area. As a result, the coating surface has sufficient hydrophilicity. More preferably, it is a hydrophilic metal oxide particle having a mode of the particle diameter in 10 to 30 nm.

Further, by using hydrophilic metal oxide particles having a mode of particle diameter in the range of 40 to 300 nm, it is possible to increase the height of unevenness on the surface and increase the thickness of the water film formed on the surface. It is possible. As a result, the ability to maintain the water film is enhanced, and an effect of preventing metal soap and rinsing components in a bathroom environment and adhesion of urban dust to the outdoors can be exhibited. In addition, there is an effect that the adhering water droplets are attracted to the portion having high irregularities, and that the water film is spread. By setting the mode of the particle size to 40 nm or more, the above-described 3 to 40 nm
The difference between the mode of the particle size of the metal oxide particles and the height of the unevenness can be sufficiently ensured, and the effect of increasing the thickness of the water film can be sufficiently exhibited. Further, by setting the mode of the particle diameter to 300 nm or less, the transparency and the mechanical strength of the film become sufficient. More preferably 40 to 100 nm
Is a hydrophilic metal oxide particle having a mode of particle diameter.

Further, by using a hydrophilic inorganic amorphous substance, it is possible to easily form a transparent and high-hardness highly durable hydrophilic film by being easily bonded to the metal oxide.

According to the above-described embodiment, the hydrophilic film of the present invention can exhibit anti-fogging properties by forming a water film quickly. In particular, it is possible to achieve a great effect by using a water film sufficiently after wetting the inside of the lid for the heating container with tap water or the like before use.

When steam or splashes adhere to the hydrophilic film in the present invention, the film formed on the surface continues to retain the adhered water, and the water adhered one after another forms a uniform water film. In this state, even when the surface temperature is lower than the dew point temperature and water vapor touches the surface, or even when water droplets adhere to the surface due to the adhesion of splashes, the water film continues to be maintained, so that light is not scattered and linearly. Since the light is transmitted, the visibility is not reduced. In the case of excessive adhesion, water flows down, but the hydrophilic coating in the present invention keeps water in a certain range, so that the anti-fog effect can be maintained.

At this time, it is preferable that the lid has an R-shape or a V-shape to assist the excessively attached water to flow down. The flowing water does not flow down as a streak but flows down in a state of being uniformly spread by the hydrophilic coating, so that there is no decrease in visibility due to light scattering.

FIG. 1 is a conceptual diagram of a heating vessel lid in which a film is formed on the surface of a transparent base material by two kinds of hydrophilic metal oxide particles having different modes of different particle diameters and a hydrophilic inorganic amorphous substance. is there. Rz and Sm are set so that the line passes through the hydrophilic metal oxide particles having the mode of the particle size in the range of 3 to 40 nm (line A in FIG. 1), and when a cross-sectional curve is obtained, 10
A line segment is set so as to pass through a hydrophilic metal oxide particle having a mode of the particle diameter in the range of 40 to 300 nm, showing an uneven structure of 10 nm ≦ Sm ≦ 300 nm with nm ≦ Rz ≦ 40 nm (the line segment in FIG. 1). B), 40n when a cross-sectional curve is obtained
300 nm ≦ Sm ≦ 1500 n for m ≦ Rz ≦ 200 nm
m shows the uneven structure. When the surface roughness, Rz, and Sm are in the above ranges, the antifogging effect due to the improvement in wettability, the high ability to maintain a water film, the transparency, and the durability can be exhibited.

Next, a method for forming a hydrophilic film will be described. As a method of forming the hydrophilic film, a step of preparing a substrate, an alkali silicate and a hydrophilic metal oxide particle having a mode of particle diameter of 3 to 40 nm, and a mode of particle diameter of 40 to 300 nm A step of preparing a mixture of hydrophilic metal oxide particles having, a step of coating the substrate with the mixture to form a coating, and, if necessary, a step of heat-treating at least the coated surface of the coating. It is possible to form a coating having a fine composite uneven structure on the surface of the material.

At this time, in the mixture, the weight ratio of the SiO ₂ amount of the alkali silicate to the hydrophilic metal oxide particles is 1
The amount of the hydrophilic metal oxide particles having a mode of the particle diameter in the range of 0: 1 to 1: 4 and 3 to 40 nm and 40 to 300 n
If the ratio of the amount of the hydrophilic metal oxide particles having the mode of the particle diameter to m is in the range of 40: 1 to 1: 4, the above-mentioned uneven structure can be formed.

The means for forming the coating is not particularly limited.
After coating by spray coating, flow coating, spin coating, dip coating, roll coating, etc., it is possible to form the clothing by drying, so that there is an optimal mixture concentration for each. There is no effect on the unevenness of the hydrophilic film, which is the most important in the present invention. At this time, at least one of boric acid, a boric acid compound, a phosphoric acid, a phosphoric acid compound, a precursor of a substance that becomes ZrO ₂ by heat treatment, Ag, and an antibacterial material such as Cu is added to a coating solution for forming a coating. Can be included.

As another method for forming the hydrophilic film of the present invention, a step of preparing a substrate, an alkali silicate and
A mixture of hydrophilic metal oxide particles having a mode of particle size at 40 nm and hydrophilic metal oxide particles having a mode of particle size at 40 to 300 nm, or a mode of particle size at 3 to 40 nm Preparing a mixed suspension of hydrophilic metal oxide particles having and a hydrophilic metal oxide particle having a mode of particle size in the range of 40 to 300 nm, coating the base material with the mixture or the mixed suspension. And forming a coating, if necessary, heat treating at least the coated surface of the coating,
Alkali silicate solution, or alkali silicate and 3-4
Preparing a second mixed suspension of hydrophilic metal oxide particles having a mode of particle size at 0 nm, further applying an alkali silicate solution or a second mixed suspension to said coated surface, A hydrophilic coating having a fine composite concavo-convex structure on the surface can be formed by the step of forming the first coating and, if necessary, the step of heat-treating at least the coated surface of the second coating.

As described above, in the present invention, the means for forming the hydrophilic film can be performed twice or more. In that case, the final film composition only needs to be composed of hydrophilic metal oxide particles and alkali silicate.

At this time, in the mixture, the weight ratio of the SiO ₂ amount of the alkali silicate to the hydrophilic metal oxide particles is 1
The amount of the hydrophilic metal oxide particles having a mode of the particle diameter in the range of 0: 1 to 1: 4 and 3 to 40 nm and 40 to 300 n
The ratio of the amount of the hydrophilic metal oxide particles having the mode of the particle size to m is in the range of 40: 1 to 1: 4, and the ratio of the amount of the hydrophilic metal oxide particles in the mixed suspension is 40. : 1 to 1:
4, and in the second mixed suspension,
When the weight ratio of the SiO ₂ amount of the alkali silicate to the hydrophilic metal oxide particles is in the range of 20: 1 to 1: 2, the above-mentioned uneven structure can be formed.

In this method as well, the means for forming the coating is not particularly limited, and the coating can be formed by spraying, flow coating, spin coating, dip coating, roll coating, etc., followed by drying to form the clothing. Although there is an optimum mixture concentration depending on the composition, there is no effect on the uneven shape of the hydrophilic film unless the ratio of each component is changed. At this time, at least one of boric acid, a boric acid compound, a phosphoric acid, a phosphoric acid compound, a precursor of a substance that becomes ZrO ₂ by heat treatment, Ag, and an antibacterial material such as Cu is added to a coating solution for forming a coating. Can be included.

The hydrophilic film of the present invention can be subjected to a heat treatment at a surface temperature of from 80 ° C. to 500 ° C. if necessary. If the temperature is too low, water resistance and the like cannot be satisfied with respect to members requiring durability.
When the heat treatment is performed at a temperature of 00 ° C. or more, the structure on the surface of the inorganic substance is stabilized, and even if water molecules are present on the surface of the coating film, the generation of chemically adsorbed water is insufficient and the hydrophilicity is deteriorated. Therefore, when heat treatment is performed, a hydrophilic film can be formed by heat treatment at the above surface temperature.

The lid for a heating container of the present invention may have a reduced antifogging property due to sticking of dirt or the like due to long-term use. However, its function can be improved by washing with a normal dishwashing detergent or the like. Recover.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
The surface roughness was measured using an SPM-9500 scanning probe microscope manufactured by Shimadzu Corporation, and the surface roughness of an arbitrary 5 μm square was calculated. In the measurement of Rz and Sm, a line segment was set for a portion not passing through the metal oxide particles having a large particle diameter exposed on the surface in the surface roughness measurement region, and Rz and Sm were calculated (Rz1, Sm1). Further, a line segment was set in a portion passing through the metal oxide particles having a large particle diameter, and Rz and Sm were calculated (Rz2, Sm2).

(Example) Only a glass member portion of a lid for a heating vessel was prepared, washed with cerium oxide powder, and then lithium silicate (lithium silicate 35 (Nissan Chemical Industries, Ltd.) )), Silica particles (Snowtex ZL, particle size 70-100 nm (manufactured by Nissan Chemical Industries, Ltd.)) as hydrophilic metal oxide particles 1, and silica particles (snow as hydrophilic metal oxide particles 2). Tex 50, particle size 20-30 nm (Nissan Chemical Industry Co., Ltd.)
Each of which is 0.75% in terms of SiO ₂ concentration.
The mixture was adjusted so as to be 0.75% and 0.75%, and the base material 4 was spray-coated and dried.
Thereafter, lithium silicate (lithium silicate 75 (manufactured by Nissan Chemical Industries, Ltd.)) is used as hydrophilic inorganic amorphous substance 3
And a mixed solution of silica particles (Snowtex 20, particle size 10 to 20 nm (manufactured by Nissan Chemical Industries, Ltd.)) as hydrophilic metal oxide particles 2 were made 0.5% and 0.75% with SiO ₂ , respectively. The prepared aqueous solution was spray-coated from above, dried, and then heat-treated at 120 ° C. for 20 minutes <Result> Surface roughness: 17.5 nm Rz1: 20 nm, Sm1: 150 nm Rz2: 120 nm, Sm2: 420 nm Was adjusted to a surface temperature of 5 ° C., and after tap water was applied to the surface, the lid was placed on a thermostatic water bath with the wet side down, the water temperature was maintained at about 60 ° C., and the occurrence of fogging was observed.
As a result, a uniform water film was formed on the inside of the glass by the generated steam, and no fogging was observed, and the inside of the container could be clearly seen.

(Comparative Example) For comparison, a similar glass member for a lid for a heating vessel was prepared, washed with a neutral detergent, and then naturally dried to obtain a test body. <Results> Surface roughness: 0.001 nm Rz1: 0.0 nm, Sm1: 460 nm (No Rz2, Sm2 because the surface is uniform) Similarly, after a surface temperature of 5 ° C., tap water was applied to the surface, A lid was placed on the water bath with the wet surface facing down, the water temperature was maintained at about 60 ° C. using the water bath, and the occurrence of fogging was observed. As a result, the lid was fogged by the vapor, making it difficult to see the inside, and condensed water droplets were formed, making the image difficult to be distorted.

[0041]

According to the present invention, the vapor adhered to the inner surface of the transparent heating vessel lid spreads uniformly as a uniform water film to prevent clouding and water droplet adhesion due to vapor aggregation.
It is possible to provide a lid for a heating container having an antifogging property with excellent visibility of food inside the container.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view of a hydrophilic coating of a transparent heating container lid according to the present invention.

[Explanation of symbols]

1 ... Hydrophilic metal oxide particles having a mode of particle size in 40 to 300 nm 2 ... Hydrophilic metal oxide particles having mode of particle size in 3 to 40 nm 3 ... Hydrophilic inorganic amorphous material 4 … Heating container lid

 ──────────────────────────────────────────────────の Continued on the front page F-term (reference) 3E084 AB10 CC01 CC06 CC08 JA10 4F100 AA01B AA03 AA03B AA04B AA17B AA19B AA20 AA20B AA21B AA27B AA28B AG00 AR00B AT00A BA02 CA12B DD07 DD07B DE01B EHB J01BJ01BJ01BJ01N AA012 HA211 HA212 HA411 HA412 HA441 HA442 HA451 HA452 MA14 NA06 PB04

Claims (17)

[Claims] 1. A fogging-resistant heating vessel lid characterized in that a water film can be retained on the inner surface of the heating vessel lid in an atmosphere of 10 to 100 ° C. and 100% RH. 2. A transparent hydrophilic film is formed on at least the inner surface of a transparent lid member for a heating vessel, wherein the hydrophilic film comprises at least hydrophilic metal oxide particles and a hydrophilic inorganic amorphous material. The hydrophilic coating has a surface roughness of 5 nm or more and 30 n in an arbitrary 5 μm square area.
m or less, and the cross-sectional curve in the same region is composed of a relatively smooth portion and a protruding portion compared to the smooth portion, and a line segment is set only in the relatively smooth portion. Rz (ten-point average roughness) and Sm (average interval of unevenness) indicated by a cross-sectional curve in the line segment are 10 nm ≦ Rz ≦
When a line segment is formed so as to pass through the protruding portion and has a roughness of 10 nm ≦ Sm ≦ 300 nm at 40 nm, Rz (ten-point average roughness) and Sm (depression of roughness) indicated by a cross-sectional curve of the line segment Average distance) is 40 nm ≦ Rz
A lid for a heating container having anti-fogging properties, having a fine composite uneven structure composed of unevenness of ≦ 200 nm and 300 nm ≦ Sm ≦ 1500 nm. 3. The hydrophilic coating according to claim 1, wherein the hydrophilic metal oxide particles have a mode of a particle diameter of 3 to 40 nm and 40 to 30.
The lid for a heating container having anti-fogging property according to claim 2, wherein the lid contains hydrophilic metal oxide particles having a mode value of the particle diameter at 0 nm and a hydrophilic inorganic amorphous substance. 4. The hydrophilic film has hydrophilic metal oxide particles having a mode of particle diameter of 10 to 30 nm and 40 to 1 nm.
4. The anti-fogging property according to claim 2, wherein a hydrophilic metal oxide particle having a mode of a particle size at 00 nm and a hydrophilic inorganic amorphous substance are contained. A lid for a heating container having: 5. The method according to claim 1, wherein the hydrophilic metal oxide particles are made of SiO ₂ ,
_{Al 2 O 3, ZrO 2,} TiO 2, the heating vessel lid with anti-fogging according to claims 2 to claim 4, characterized in that of the SnO ₂ is at least one or more. 6. The method according to claim 2, wherein the hydrophilic inorganic amorphous material is at least one of alkali silicate, borosilicate, alkali zirconium salt, and phosphate. The lid for a heating container having antifogging property according to any one of the above. 7. The method according to claim 1, wherein the alkali silicate is sodium silicate.
7. The heating container lid having antifogging property according to claim 2, wherein the lid is at least one of potassium silicate, lithium silicate, and ammonium silicate. 8. The lid for a heating container having antifogging properties according to claim 2, wherein the coating contains boric acid and / or a boric acid compound. 9. The lid for a heating container having anti-fogging property according to claim 2, wherein the coating contains phosphoric acid and / or a phosphoric acid compound. 10. ZrO ₂ is introduced into said coating by heat treatment.
The lid for a heating container having anti-fogging property according to any one of claims 2 to 9, further comprising a precursor of a substance to be used. 11. The anti-fogging heating container lid according to claim 2, wherein the coating contains an antibacterial material. 12. The film thickness of the hydrophilic coating is 0.1 μm
2 to 1 mm.
2. The lid for a heating container having anti-fogging property according to any one of 1. 13. The heating container having anti-fogging property according to claim 2, wherein the shape of the heating container lid is an R shape or a V shape. Cover. 14. The water film can be held on the inner surface of the lid for the heating vessel in an atmosphere of 10 to 100 ° C. and 100% RH. 4. A lid for a heating container having anti-fogging property according to 4. 15. A heating vessel, wherein the heating vessel lid according to any one of claims 1 to 14 is used after a water film is formed on at least the inner surface thereof in advance by contacting with water. Anti-fog method for lids. 16. A hydrophilic metal oxide particle having a mode of particle diameter of 3 to 40 nm, a hydrophilic metal oxide particle having a mode of particle size of 40 to 300 nm, and a hydrophilic inorganic amorphous material And an anti-fogging coating composition for a lid for a heating container. 17. A hydrophilic metal oxide particle having a mode of particle diameter of 10 to 30 nm, a hydrophilic metal oxide particle having a mode of particle size of 40 to 100 nm, and a hydrophilic inorganic amorphous material And an anti-fogging coating composition for a lid for a heating container.