KR102079068B1 - Cooking utensil having thermochromic layer - Google Patents

Abstract

The present invention relates to a cooking utensil on which a thermochromic coating layer is formed. More specifically, the present invention relates to a cooking appliance on which a non-stick coating layer is formed on a surface, and a thermochromic coating layer is formed by a composition for thermochromic coating on the top or bottom of the non-stick coating layer. The composition for thermochromic coating is composed of aminoalkylsilane, inorganic acid, an inorganic pigment, a thermochromic pigment, and a solvent, so that it is possible to visually confirm the temperature of the cooking utensil surface and lifespan of the non-stick coating layer constituting the surface.

Description

Cookware with thermochromic coating layer. {COOKING UTENSIL HAVING THERMOCHROMIC LAYER}

The present invention relates to a cookware in which a thermochromic coating layer is formed, wherein the thermochromic coating layer capable of visually confirming the temperature of the cookware surface and the lifespan of the non-stick coating layer constituting the surface by forming a thermochromic pattern on the surface is cooked. A cooking appliance formed on the surface of the appliance.

In the kitchen utensils for cooking food, which is in contact only with a coating layer is generally formed on the metal surface. Since such a coating layer requires heat resistance, 70 to 80% is made of Teflon coating. Such a Teflon coating layer has a problem in that the manufacturing process is simple and excellent in non-sticking property, which is suitable for cooking utensils, but is worn or peeled off by use.

In order to solve this problem, the coating composition to form a coating layer is optimized to develop a product that improves the durability of the coating layer. In addition, by forming a pattern with a thermochromic ink so that the user can visually check the life of the coating layer to determine the replacement time of the product through the color change.

In addition, since the pattern formed of the thermochromic ink makes it possible to intuitively check the surface temperature of the cooking utensil, the convenience of use of the cooking utensil may be increased.

In Korean Patent No. 10-0740674, the upper color coating layer is formed on the upper surface of the non-stick coating layer of the cooking utensil so that the color is changed as the upper color coating layer is worn so that the user can visually check the replacement time.

However, in the prior art, the ink constituting the top color coating layer is not described, but simply changed from red to purple. The color of the coating layer printed with respect to the color of the surface of the cookware is changed from red to purple. There is a problem that it is not easy to recognize the sharp color change.

In addition, the Republic of Korea Patent Publication No. 10-2016-0092193, Republic of Korea Patent Publication No. 10-1292555 has a characteristic that the color change when heated by applying a thermochromic coating layer on the surface of the cooking utensils and return to the original color when cooled.

However, when the discoloration effect is expressed using Zion pigment, it is difficult to visually clearly identify the change in color, and there is a problem in that it is difficult to visually indicate the occurrence of wear due to use.

The present invention is to solve the problems of the prior art as described above, by adding a thermochromic coating layer to the non-stick coating layer formed on the surface of the cookware to generate a thermochromic effect when using the cookware, the non-stick coating layer It is an object of the present invention to provide a cooking utensil formed with a thermochromic coating layer that allows a user to grasp when to replace a product by generating a color change effect according to wear.

The cooking utensil having a thermochromic coating layer of the present invention for solving the above problems is a non-stick coating layer is formed on the surface of the cooking utensils, the thermochromic coating composition on the upper or lower portion of the non-stick coating layer As the coating layer is formed, the thermochromic coating composition is characterized by consisting of aminoalkylsilane, inorganic acid, inorganic pigment, Zion pigment and solvent.

In this case, it is preferable that the aminoalkylsilane has 2 to 3 aminoalkyl groups.

In addition, an indicator color coating layer may be additionally formed on or under the non-stick coating layer.

Cookware according to the present invention by adding a thermochromic coating layer to the Teflon coating layer formed on the surface to generate a thermochromic effect when using the cookware to increase the ease of use, and generates a color change effect according to the wear of the Teflon coating layer By doing so, the user can grasp the replacement time of the product.

1 is a diagram illustrating a thermochromic coating layer formed on a surface of a cookware according to one embodiment.
2 is a view illustrating a thermochromic coating layer formed on a surface of a cookware according to another embodiment.

Hereinafter, the present invention will be described in detail.

The present invention relates to a cooking appliance, characterized in that the thermochromic coating layer is formed. In general, a non-stick coating layer is formed on the surface of the cooking utensil, the cooking utensil of the present invention is a thermochromic coating layer is formed by the thermochromic coating composition on the upper or lower portion of the non-stick coating layer.

The thermochromic coating layer enables the user to easily check the temperature of the surface of the cookware by the thermochromic effect generated when the cookware is heated, and the non-stick coating layer may be worn according to the use of the cookware. The color change effect occurs when the user can easily check the replacement time of the cookware.

The thermochromic coating layer may be printed in a pattern of various shapes on the surface of the cooking utensil, in one embodiment a light red ring pattern on the red surface of the cooking utensil as shown in FIG. 1 (a) (FIG. 1 (a)). ) Or a circular pattern (FIG. 1B) may form a thermochromic coating layer.

When the light red ring pattern or the circular pattern is formed, the color of the thermochromic coating layer when the cooking utensil is heated may be thermochromic and may have the same color as the red surface of the cooking utensil. Therefore, the user can check the surface temperature of the cooking utensil through the visual effect that the light red ring pattern or the circular pattern disappears as the surface temperature of the cooking utensil increases.

In another embodiment, the indicator color coating layer printed in red is formed on the black surface of the cooking utensil as shown in FIG. 2 (a), and the thermochromic coating layer is formed in a light red ring pattern to overlap the indicator color coating layer. Can be. In addition, as shown in FIG. 2 (b), the pattern may be formed such that the circular pattern of the indicator color coating layer printed in red on the black surface of the cooking appliance and the light red circular pattern of the thermochromic coating layer overlap each other.

In this case, since the color of the indicator color coating layer does not change due to heat, the color of the thermochromic coating layer when the cookware is heated is discolored and becomes the same color as the color of the indicator color coating layer. Therefore, the user can confirm the surface temperature of the cooking utensil through the visual effect that the pattern of the indicator color coating layer and the pattern of the thermochromic coating layer become the same color.

The thermochromic coating layer and the indicator color coating layer may be formed by printing on the upper or lower portion of the non-stick coating layer. For example, the thermochromic coating layer pattern alone or the pattern of the thermochromic coating layer and the indicator color coating layer may be printed on the surface of the cookware, and a non-stick coating layer may be formed thereon. In this case, when the non-stick coating layer is worn according to the use of a cooking utensil, the pattern of the thermochromic coating layer and / or the indicator color coating layer is changed to a color different from the initial state, so that the user can know when to replace. You can do that.

In addition, the non-stick coating layer may be first formed on the surface of the cooking utensil, and the pattern of the thermochromic coating layer and / or the indicator color coating layer may be formed on the surface of the cooking utensil on which the non-stick coating layer is formed on the front surface. In this case, as the non-stick coating layer is worn, the thermochromic coating layer and / or the indicator color coating layer are also worn, so that the color becomes lighter than the initial state or the scratch surface is visually displayed so that the user can confirm the replacement time. do.

It is important that the thermochromic coating layer is formed at the top or the bottom of the non-stick coating layer, and the initial state of the thermochromic coating layer and the discoloration state according to the use of cooking utensils should be clearly identified.

To this end, it is necessary to increase the thermochromic and color variable effects by improving the thermochromic coating composition for forming the thermochromic coating layer. In the present invention, a composition consisting of an aminoalkylsilane, an inorganic acid, an inorganic pigment, a Zion pigment and a solvent is applied as the composition for thermochromic coating. In this way, in the prior art, the color change effect is more pronounced compared to the cooking utensils that cause color change using Zion pigment, making visual confirmation easier.

In order to increase the visual effect, it is preferable to increase the content of the inorganic pigment for realizing the Zion pigment and the contrast color, but if the content is increased, the dispersibility and compatibility are lowered, and stability is difficult to maintain for a long time. Therefore, in the prior art, the composition is prepared in a two-component type containing an inorganic pigment and a zion pigment, respectively, or a coating composition is formed using the zion pigment at 10 wt% or less.

In the present invention, 5 to 10% by weight of aminoalkylsilane, 0.1 to 5% by weight of inorganic acid, 10 to 20% by weight of inorganic pigment, 20 to 30% by weight of Zion pigment and 40 to solvent as a composition constituting the thermochromic coating composition. The composition is composed of 50% by weight, and by increasing the content of the inorganic pigments and Zion pigments, the color difference is further increased by the color change.

For this purpose, in particular, the aminoalkyl silane having 2 to 3 aminoalkyl groups is used, and when the aminoalkyl group is 2 to 3, it has been confirmed that the effect of improving the dispersibility of the inorganic pigment and the Zion pigment is improved. In addition, when the content of the aminoalkylsilane is too small, too much was found to reduce the particle dispersibility of the pigment.

Specific examples of such aminoalkylsilanes include tris (cyclohexylamino) methylsilane, bis (dimethylamino) methylsilane, bis (dimethylamino) dimethylsilane and tris (dimethylamino) silane. A better effect could be obtained when using double tris (cyclohexylamino) methylsilane, presumably because the cyclohexylamino group bonded to the silicon atom is larger in volume than the alkylamino group to promote dispersion between the pigment particles.

In addition, a white inorganic pigment such as silica or titanium dioxide may be used as the inorganic pigment, and the inorganic pigment and the Zion pigment are mixed so that the inorganic pigment serves as a background color, thereby making it easy to visually check the color difference. The inorganic pigments and Zion pigments may be contained by varying the content, the color of the thermochromic coating layer itself can be made clear by setting the content of Zion pigment to 20 to 30% by weight. In addition, when the content of the inorganic pigment and the Zion pigment is too large, the dispersibility is lowered and the durability of the coating layer is deteriorated, so it is preferable to be contained in the content range.

In addition, the inorganic acid may be hydrochloric acid or sulfuric acid, which is commonly used as being used for increasing the binding force in the coating process through the hydrolysis of the silane compound. However, if the content of the inorganic acid is too small or too much, the hydrolysis is insufficient or the durability of the coating layer due to the pH change.

In addition, it is preferable to use a mixed solvent of water and alcohol as the solvent. In the solvent consisting only of water, there is a problem in that the hydrolysis rate of the silane compound is excessively fast and the durability of the coating layer is reduced. For this purpose, it is preferable to mix water and alcohol in a weight ratio of 6: 4 to 9: 1. In addition, it is preferable to use ethanol or isopropanol as the alcohol, since the alcohol is commonly used in the sol-gel reaction of the silane compound.

The non-stick coating layer of the cookware according to the present invention can be formed using a conventional fluorine resin. For example, the non-stick coating layer may be formed by stacking the primer layer and the top coating layer on the surface of the substrate constituting the cooking utensil. In this case, the primer layer and the top coating layer may be polytetrafluoroethylene (PTFE), It may be formed using a composition comprising polyamideimide (PAI) and additives. At this time, the polyamideimide (PAI) is contained in the composition to act as a binder. As the additive, any one or more of a colorant, a dispersant, an antifoaming agent, and a filler may be used.

The process of forming the non-stick coating layer may proceed as follows.

The sandblasting surface-treated substrate is coated with a primer composition with a spray gun and placed in an oven and heat-treated at about 200 ° C. for 5 to 10 minutes. The substrate is then naturally cooled and coated thereon by spraying the top coating composition with a spray gun. The coated substrate may be placed in an oven again and heat-treated at about 300 to 350 ° C. for 20 to 30 minutes, and then cooled to form a non-stick coating layer.

In addition, the process of forming the thermochromic coating layer and / or the indicator color coating layer can also be carried out in the same process sequence, according to the type of the coating composition, the heat treatment at a temperature of less than 30 minutes to 200 ℃ or less heat treatment in less than 30 minutes desirable.

In order to evaluate the characteristics of the cookware according to the present invention, a frying pan was prepared as follows.

After the non-stick coating layer was formed on the surface of the frying pan, a circular pattern was formed on the surface of the thermochromic coating composition. As the thermochromic coating composition, a composition as shown in Table 1 was used.

In Example 1, tris (cyclohexylamino) methylsilane was used as the silane compound, and in Example 2, bis (dimethylamino) dimethylsilane was used. In Comparative Example 1, tetrakis (dimethyl amido) silane was used as the silane compound. In Comparative Example 2, tetraethylorthosilicate (TEOS) was used. In addition, the solvent used was a mixed solvent in which water and alcohol were mixed at a weight ratio of 7: 3.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Silane compound 8 8 8 8 Inorganic pigments 15 15 15 15 Zion Pigment 28 28 28 28 Sulfuric acid 0.5 0.6 0.5 0.5 menstruum 48.5 48.4 48.5 48.5

In order to evaluate the basic physical properties of the prepared cookware, coating film thickness, gloss, surface hardness, adhesion, surface state, and nonstick properties were measured.

The film thickness and gloss were measured on 9 surfaces using a film thickness meter and a gloss meter, respectively, and the final measured value was determined as the average value of the remaining values except the maximum and minimum measured values.

The surface hardness is determined by using a pencil hardness tester, starting from pencil hardness 2H and then reciprocating 5 ~ 6cm up and down 10 times with up and down movement to determine whether there is an abnormality on the coated surface. It was.

In order to evaluate the adhesiveness, the surface of the surface was scratched with a lattice pattern, and the process of adhering and detaching the tape was repeated 10 times to evaluate the coating layer peeling.

Surface condition evaluation was evaluated by determining the pin-holes, cracks, etc. in the coating surface with a 50x magnification through the surface distribution test.

In addition, the non-stickability was evaluated by dropping off the surface by frying eggs in the state heated to 200 ℃ or more without applying cooking oil on the surface.

As a result, in Example 1, 2 and Comparative Examples 1 and 2, coating film thickness, gloss, surface hardness, adhesiveness, surface state, and nonstick property were all favorable.

Next, to evaluate the thermochromic effect, each frying pan was heated to measure the color coordinates of the pattern of the thermochromic coating layer and the surface color of the cookware (CM5 (Konica Minolta Ltd.), SCE mode (D65)). The results are shown in Table 2. In Table 2, (DELTA) L * is the value which calculated | required the brightness difference after room temperature and heating, and (DELTA) a * and (DELTA) b * are the values which calculated | required the chromaticity difference after room temperature and heating.

ΔL * Δa * Δb * Example 1 1.59 7.95 0.31 Example 2 1.28 8.83 0.54 Comparative Example 1 0.65 8.63 0.23 Comparative Example 2 0.14 8.38 0.04

 Looking at the results of Table 2, Examples 1 and 2 and Comparative Examples 1 and 2 both showed a thermochromic phenomenon by heating, showing a difference in chromaticity. In particular, in Example 1 and Example 2, the difference in brightness due to heating was large, and it was shown that the change in color due to thermochromic can be observed more clearly visually.

In addition, after the egg is fried in a state in which the cooking utensils are heated at 200 ° C. or higher without applying cooking oil, the process of washing the cookware in a dishwasher is repeated 100 times, and then the difference between brightness and chromaticity of the cookware is measured. It was. The results are shown in Table 3.

ΔL * Δa * Δb * Example 1 1.86 5.52 0.52 Example 2 1.58 4.86 0.42 Comparative Example 1 0.96 6.21 0.13 Comparative Example 2 0.89 6.56 0.14

Referring to the results of Table 3, in Examples 1 and 2, according to the use of the cooking utensils, the intrinsic colors of the thermochromic coating layer were greatly changed, resulting in lower brightness and lighter redness in chromaticity. On the other hand, in Comparative Examples 1 and 2, it was difficult to visually clearly see the change in intrinsic color forming the pattern of the thermochromic coating layer because the difference in brightness was not large.

Forming a pattern with the thermochromic coating layer according to the present invention from these results can visually clearly see the color change of the pattern on the surface of the cookware, it is easy to detect the temperature change on the surface of the cookware during cooking, It was found that the replacement cycle could be easily recognized.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the scope of the invention. Therefore, the appended claims include such modifications and variations as long as they belong to the gist of the present invention.

Claims (3)

In the cooking utensil having a non-stick coating layer on the surface,
The thermochromic coating layer is formed on the upper or lower portion of the non-stick coating layer by the thermochromic coating composition,
The thermochromic coating composition is composed of 5 to 10% by weight of aminoalkylsilane, 0.1 to 5% by weight of inorganic acid, 10 to 20% by weight of inorganic pigment, 20 to 30% by weight of Zion pigment and 40 to 50% by weight of solvent.
The aminoalkyl silane is tris (cyclohexylamino) methyl silane, bis (dimethylamino) methyl silane, bis (dimethylamino) dimethyl silane or tris (dimethylamino) silane cooker formed with a thermochromic coating layer.
delete The method according to claim 1,
Cookware having a thermochromic coating layer is characterized in that to form an additional color coating layer on the top or bottom of the non-stick coating layer.

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