KR102236947B1 - Xtrema T composition for coating providing iron-like texture to aluminum-based cookware and method for coating using the same - Google Patents

Abstract

The present invention relates to a primer coating composition for ceramic coating comprising colloidal silica, methyltrimethoxysilane, a silicone glycol copolymer and an acid catalyst, a cast iron-like texture coating method on an aluminum surface using the coating composition, and a ratio prepared accordingly. It relates to an aluminum cookware having a tacky cast iron-like texture.

Description

Xtrema T composition for coating providing iron-like texture to aluminum-based cookware and method for coating using the same}

The present invention relates to a primer coating composition for ceramic coating comprising colloidal silica, methyltrimethoxysilane, a silicone glycol copolymer and an acid catalyst, a cast iron-like texture coating method on an aluminum surface using the coating composition, and a ratio prepared accordingly. It relates to an aluminum cookware having a tacky cast iron-like texture.

Cooking utensils such as frying pans and pots have been mainly manufactured using materials such as general steel, aluminum alloy, aluminum plate, and stainless steel. In particular, aluminum materials that are lightweight, easy to form, and inexpensive to manufacture are often used.

However, devices made of these materials have many problems, such as repeated expansion and contraction of metal by repeated rapid heating and rapid cooling, damage to the coating surface due to consumer negligence, and oxidation, peeling, and corrosion. In particular, the coating is peeled off for the above reasons to expose metal components such as aluminum, and food is pressed to the area where the coating is peeled, and the substrate is corroded by the acid component of the food. It has been reported that it can accumulate and cause side effects such as Alzheimer's disease.

Therefore, cooking utensils can withstand high cooking temperatures, have strong corrosion resistance and peeling durability against surface abrasion and scratches, and have introduced various coating layers to impart non-adhesiveness to which food is not pressed.

The most widely used method for this purpose is to introduce a non-stick coating layer containing a fluororesin, and fluororesin, an active ingredient, has very low miscibility with other materials and has low coating power on a smooth surface. In order to improve the bonding strength of the sandblasting process, a pretreatment process of increasing the surface area by forming a fine structure is essential. On the other hand, PFOA (perfluorooctanoic acid), a material mainly used for coating the fluororesin, has been classified as a potential carcinogen by the US Environmental Protection Agency, and considering that conventional cookware is used at high temperatures, the fluororesin itself decomposes at high temperatures. The possibility of exposure to hazardous substances cannot be excluded.

Therefore, the introduction of a ceramic coating layer is used in a coating or surface treatment method that does not use a fluororesin. The ceramic coating is a technology that prevents metal corrosion of household kitchen utensils by coating a fine ceramic coating using inorganic paints and inorganic ceramic coating compositions having properties such as excellent heat resistance, contamination resistance, chemical resistance, and durability on the metal surface of the product. As, in household kitchen utensils, it is mainly applied to cooking containers in order to prevent corrosion of metal and to prevent food from sticking to each other during cooking.

Ceramic-coated kitchen utensils are capable of implementing a variety of colors that are difficult to express with other coatings such as fluorine coating, and the coating does not peel off or burn even at temperatures above 350℃, as well as many advantages such as non-toxicity, antibacterial resistance, and far-infrared rays derived from natural inorganic substances. Nevertheless, it lacks the non-stick function, and even if it has non-adhesive properties, it does not last for a long time.

Accordingly, it is necessary to discover a coating method capable of improving non-adhesiveness while showing a unique visual effect by introducing a coating layer using a ceramic material that is harmless to the human body.

The inventors of the present invention have made intensive research efforts to discover a coating method capable of improving non-adhesiveness while imparting a texture similar to cast iron to light aluminum cookware with only a ceramic coating layer. By introducing a ceramic coating layer using a primer coating solution containing colloidal silica and an acid catalyst as precursors, the viscosity is controlled including the coalescence, and gives a unique visual and tactile effect by giving the embossed texture peculiar to the cast iron material. , It was confirmed that the contact with food can be reduced due to the texture pattern and remarkably improved non-adhesion can be imparted by retaining oil in the pattern, and the present invention was completed.

A first aspect of the present invention provides a primer coating composition for a ceramic coating having a cast iron-like texture comprising colloidal silica, methyltrimethoxysilane (MTMS), a silicone glycol copolymer, and an acid catalyst.

In a second aspect of the present invention, a primer coating composition for ceramic coating having an iron-like texture comprising colloidal silica, methyltrimethoxysilane (MTMS), a silicone glycol copolymer, and an acid catalyst is applied to all or part of an aluminum cookware. A first step of forming a primer coating layer by applying it to the surface; A second step of forming a ceramic undercoat layer; And it provides a cast iron-like texture coating method of the aluminum surface comprising a third step of forming a ceramic top coat layer.

A third aspect of the present invention is a primer coating layer having an average thickness of 15 to 30 μm and a roughness of ±15 μm, formed by sequentially stacking on all or part of the surface of an aluminum cookware; A ceramic undercoating layer uniformly formed with an average thickness of 15 to 25 μm; It provides an aluminum cookware having a cast iron-like texture comprising; and a ceramic topcoat coating layer uniformly formed with an average thickness of 5 to 10 μm.

Hereinafter, the present invention will be described in more detail.

The present invention uses a composition for ceramic coating that contains a predetermined component having a controlled viscosity, and introduces a primer coating layer in a controlled condition and/or amount. It is based on discovering a coating method that can emulate a unique texture that realizes a tactile effect, as well as impart remarkably improved non-adhesiveness without fluorine coating treatment, which may be harmful to the human body.

In an attempt to realize the texture in this way, a coating showing texture among fluorine coatings has been implemented, but except for the use of a fluorine coating that is harmful to the human body, this has an intaglio that is given by the drying shrinkage of the paint during embossing and heat treatment. And since it is a three-dimensional effect in a way that the embossing and the engraving of about 30% coexist, when food or foreign matter enters the engraving, it is difficult to remove by ordinary washing, and accordingly, the non-adhesiveness is markedly deteriorated. However, the present invention not only excludes harmful fluorine coating, but also overcomes the disadvantages caused by the presence of the above-described intaglio in realizing the texture, and at the same time, the relatively concave pattern formed along the absence of the protrusion is an oil rod. It plays the role of so that cooking oil such as cooking oil spreads evenly and stays during cooking.

Accordingly, the present inventors refer to the cast iron-like textured ceramic coating implemented according to the present invention as described above as “Xtrema T” coating.

The present invention provides a primer coating composition for a ceramic coating having a cast iron-like texture comprising colloidal silica, methyltrimethoxysilane (MTMS), a silicone glycol copolymer, and an acid catalyst.

Furthermore, it provides a ceramic undercoating composition and a ceramic topcoating composition selected to maintain the texture formed by the primer coating composition. At this time, as the primer coating composition, the primer coating composition having a controlled viscosity including a silicone glycol copolymer may be used in the same manner, but is not limited thereto. Meanwhile, as the top coat composition, a ceramic coating composition used for conventional top coat coating may be used, but is not limited thereto.

The term "cast iron-like texture" in the present invention refers to a texture that simulates a rough surface that looks like a distribution of fine particles that uniquely appear on the surface of a cast iron material, and round particles without an intaglio structure formed by being depressed into the inside. It may mean a three-dimensional surface shape formed in a protruding structure formed by overlapping these particles in a viscous solution containing them.

For example, in order to implement additional texture and/or color, the primer coating composition may further include a filler, a pigment, or both, but is not limited thereto. Silica, kaolin, alumina, zirconia, barium sulfate, etc., as fillers that can be used in the primer coating composition of the present invention, iron oxide, copper oxide, titanium dioxide, trivalent chromium, cobalt oxide, carbon, etc., are used alone or as pigments. Two or more materials selected from these may be mixed and used, but the present invention is not limited thereto.

For example, the primer coating composition of the present invention may be a composition composed of three independent components of composition A including colloidal silica sol, composition B including MTMS and silicone glycol copolymer, and composition C including an acid catalyst.

At this time, the composition A may further include 0.5 to 1.5 times the weight of the filler, 0.25 to 1 times the weight of the pigment, or both, based on the weight of the colloidal silica sol contained therein. For example, these fillers and pigments may each be milled to have a size of 1 to 5 μm independently, and may be in the form of particles whose size is adjusted, but is not limited thereto.

For example, the composition B may contain 50 to 90% MTMS based on the total weight, and may further include a surfactant, a surface stabilizer, a dispersant, an alcohol solvent, etc., but is not limited thereto.

For example, the primer coating composition of the present invention may be prepared by mixing composition A, composition B, and composition C in a ratio of 60 to 80:20 to 35:0.1 to 0.5 based on weight. At this time, the composition finally provided may include 0.05 to 2% of the silicone glycol copolymer based on the total weight.

The term "silicone glycol copolymer" of the present invention is usually used in various fields as a glass reinforcing agent, an impact resistance reinforcing agent, a pigment surface substitute, a slip agent, etc., but the composition of the present invention is used to control viscosity. Can be used for any purpose. The silicone glycol copolymer is a material suitable for use in cooking utensils and the like because it is a non-hazardous material with very low toxicity used in cosmetics and the like.

Specifically, the present invention contains the silicone glycol copolymer in an amount of 0.05 to 2% based on the weight of the total composition, and accelerates the drying rate to a desired level by adjusting the viscosity, thereby performing the step of forming a ceramic undercoat layer after without a separate drying process. Even if it proceeds in a continuous wet-on-wet method, the primer coating composition can maintain the formed texture without being absorbed by the ceramic undercoating solution or not. However, if the drying speed of the primer coating layer is too fast, it may be difficult to bond with the ceramic undercoat layer formed on the surface thereof, and the absence of such bonding may cause peeling of the coating layer and/or decrease in corrosion resistance, as described above. It is important to control the viscosity of the composition by adjusting the content of the silicone glycol copolymer so that it has a desired level of drying rate.

The term "acid catalyst" of the present invention is a component added to accelerate the hydrolysis of colloidal silica and MTMS, and formic acid may be used, but is not limited thereto. For example, the acid catalyst may be included in an amount of 0.1 to 1% based on the weight of the total composition, but is not limited thereto.

The primer coating composition of the present invention may be used to prepare an aluminum substrate having a cast iron-like texture as follows.

The cast iron-like texture of aluminum cookware includes a primer coating composition for ceramic coating with a cast iron-like texture containing colloidal silica, methyltrimethoxysilane (MTMS), a silicone glycol copolymer, and an acid catalyst. Or a first step of forming a primer coating layer by applying it to a portion of the surface; A second step of forming a ceramic undercoat layer; And a third step of forming a ceramic top coat layer.

At this time, as the primer coating composition, the above-described primer coating composition of the present invention may be used.

Meanwhile, the primer coating layer formed from the first step may have an average thickness of 15 to 30 μm and a roughness of ±15 μm. It is possible to achieve the purpose of improving non-adhesiveness by providing a desired level of three-dimensional effect and reducing contact with food by having a somewhat large thickness deviation as described above.

For example, in the coating method, in order to maintain the texture formed from the first step, the second step, which is continuously performed after the formation of the primer coating layer, is a nozzle having a size reduced to 70 to 85% compared to a conventional spray coating, At a distance of 1.2 to 2 times increased, it may be performed by spraying about 1.2 to 2 times stronger at a higher injection pressure, but is not limited thereto. For example, the second step may be performed by spraying at a pressure of 1.5 to 2 bar at a distance of 30 to 50 cm using a nozzle of a spray gun having a size of 0.8 to 1 mm, but is not limited thereto.

For example, the third step may be performed by a ceramic coating method known in the art, without limitation, using a ceramic composition known in the art, but is not limited thereto.

At this time, the ceramic undercoat layer formed from the second step may be uniformly formed on the entire coating surface with an average thickness of 15 to 25 μm so as to maintain the texture of the primer coating layer formed from the first step.

For the same reason, the ceramic top coat layer formed from the third step can be uniformly formed with an average thickness of 5 to 15 μm.

For example, when the thickness of the ceramic undercoat layer and/or the top coat layer is formed to be thinner than each of the aforementioned lower limits, uniform coating over the entire surface to be coated may be difficult, and when formed thicker than each of the aforementioned upper limits In the case, the surface of the three-dimensional texture formed by the primer coating layer may not exhibit sufficient roughness, or may disappear completely by being buried in the above coating layer.

For example, the first to third steps may be achieved in a wet-on-wet method that is successively and sequentially performed without a separate drying process. As described above, since the primer coating composition used in the manufacturing method of the present invention has a predetermined viscosity including a silicone glycol copolymer in a controlled content, it can be dried at a desired level, so it is continuously without a separate drying process. Even if the ceramic undercoating is performed, the coating layer is not separated or absorbed by the ceramic undercoating solution, and a distinct coating layer having a desired texture can be maintained.

Further, the present invention is formed by sequentially stacking on all or part of the surface of the aluminum cookware, a primer coating layer having an average thickness of 15 to 30 μm and roughness of ±15 μm; A ceramic undercoating layer uniformly formed with an average thickness of 15 to 25 μm; And a ceramic topcoat coating layer uniformly formed with a thickness of 5 to 15 μm on average, including, a coated surface having a cast iron-like texture formed on an aluminum material, for example, an aluminum-based cookware including the same.

For example, in the aluminum cooking utensil having a cast iron-like texture of the present invention, contact with food is reduced due to the fine three-dimensional structure of the texture formed on the surface, and the space between the three-dimensional structures acts as a flow path for guiding oil, so that it can be evenly distributed. It is characterized by having improved non-adhesiveness by 150 to 300% compared to aluminum cookware having a smooth surface including only a ceramic undercoat layer and a ceramic topcoat layer formed to have the same thickness, and does not include a primer coating layer.

The cast iron-like texture ceramic coating according to the present invention can be applied to a light aluminum cookware to give a cast iron-like texture while improving non-adhesiveness, so it is light while showing a unique visual and tactile effect. It can be usefully used in the manufacture of convenient functional cooking utensils.

1 is a diagram schematically showing a conventional ceramic coating process for cookware made of aluminum.
2 is a diagram schematically showing a manufacturing process of a primer ceramic coating solution for texture coating according to the present invention.
3 is a diagram showing the configuration and form of (a) a triple coating layer structure according to the present invention, (b) a configuration and shape of a general ceramic coating layer, and (c) a triple coating layer structure according to the present invention.
4 is a view showing the result of observing the surface of the coating layer with a microscope in order to confirm the textured surface formed by the textured coating according to the present invention.
5 is a view showing the observation result using a laser microscope performed to confirm the change in the roughness of the coated surface by the texture coating according to the present invention. Specifically, a) is an image of the coated surface and an illuminance graph in the displayed cross-section, b) is an image that visualizes the change in roughness due to the texture coating according to the present invention in color, and c) is the scale of the texture, for example , Represents an illuminance graph for confirming the height and/or size (or width) of the three-dimensional structure.
6 is a diagram showing (a) a contact angle by a textured coating according to the present invention compared with the result of (b) an existing ceramic coating.

Hereinafter, the present invention will be described in more detail through examples. These examples are for explaining the present invention more specifically, and the scope of the present invention is not limited by these examples.

Example 1: How to coat aluminum with a cast iron-like texture

Step 1: texture primer coating

A primer solution for ceramic coating through a hydrolysis-condensation reaction was prepared using colloidal silica as a precursor and methyltrimethoxysilane (MTMS) as a binder.

Specifically, a composition A containing colloidal silica sol, fillers (silica, alumina, barium sulfate, kaolin and mica) and pigments (copper oxide, iron oxide and titanium dioxide) in a weight ratio of 4:4:2, 90 to 95 weight A composition B containing% MTMS and a silicone glycol copolymer , and a composition C containing formic acid as an active ingredient as a catalyst were prepared, respectively. A primer coating solution was prepared by mixing the compositions A, B and C in a weight ratio of 70:27.7:0.3. At this time, the filler and pigment contained in the composition A were milled for dispersion and/or particle size control to have a size of 1 to 5 μm.

The primer prepared as described above was coated on the surface of the substrate by spray coating. When the sprayed coating solution was coated on the surface of an aluminum substrate, the silica particles existed in the form of individual small spheres. The average thickness of the primer coating layer formed as described above was 15 to 30 μm, and showed a roughness of ±15 μm.

Step 2: ceramic primer coating

After the primer coating in Step 1, ceramic undercoating was performed in a wet-on-wet manner without a separate drying process. For example, the primer coating solution may include fillers such as silica, kaolin, barium sulfate, alumina, mica, etc. to the colloidal silica sol precursor; Pigments containing copper oxide, titanium dioxide, trivalent chromium, carbon, and the like; Dispersant; And a surface stabilizer such as an additive composition A was composed of "composition containing MTMS and not dry additives in a solvent of alcohols B ', and the composition with water and an acid catalyst C' comprising a. In order to maintain the texture of the surface made by the arrival of the primer according to step 1, the primer coating is a spray spraying with a nozzle having a diameter of 0.8 to 1.0 mm, and spraying at a pressure of 1.5 to 2.0 bar while maintaining a spray distance of 30 to 50 cm. The coating method was applied. The primer coating layer thus formed was adjusted to have a thickness of 15 to 25 μm.

Step 3: ceramic topcoat coating

Following the ceramic base coating in Step 2, ceramic top coating was performed. The underlying coating layer formed accordingly was adjusted to have a thickness of 5 to 15 μm, and as a result, the finally formed coating layer had a total thickness of 35 to 70 μm. For example, ceramic top coat coating was performed by a general spray coating method using a conventional ceramic coating composition.

Comparative example 1: Basic ceramic coating method

By omitting Step 1 of Example 1, and performing ceramic undercoat and ceramic topcoat coating sequentially on aluminum-based cookware in the same manner as in Steps 2 and 3 under universal conditions, ceramic undercoat and topcoat with the same thickness. A basic ceramic coated cookware with a coating layer was prepared.

Experimental example 1: illuminance evaluation

In order to confirm the texture formed on the surface to which the series of coating layers were introduced according to Example 1, the cross section of the coating layer was confirmed by SEM, and the results are shown in FIG. 4. As shown in FIG. 4, the structure of the coated surface was formed discontinuously and having different sizes and heights was confirmed.

Further, the roughness of the surface of the coating layer was measured with a laser microscope, and the results are shown in FIG. 5. As shown in FIG. 5, the coating layer of Example 1 was found to have a non-uniform surface showing a height difference of about 3 to 4 μm to a maximum of 10 μm within the measurement range.

Experimental example 2: Contact angle Test

In order to confirm the non-stick effect by the textured coating layer formed according to Example 1, the contact angle was tested using water droplets on the surface of the coating layer, and the results are shown in FIG. 6. For comparison, the same experiment was performed on the coating layer of Comparative Example 1 in which the basic ceramic coating was performed. As shown in Figure 6, compared to the coating layer of Comparative Example 1 exhibited an increased contact angle in the coating layer of Example 1.

Experimental example 3: Non-stick evaluation

In order to evaluate the non-stick improvement due to the anisotropic surface, non-stick evaluation was performed on the conventional ceramic coated cookware and the textured coated cookware according to the present invention as follows, and the results are shown in the following table. It is shown in 1. The specific test method is as follows:

1. Prepare coated cookware.

2. Break an egg in a cookware heated to 180 to 190℃ with a hot plate and hold for 80 seconds.

3. After 80 seconds have elapsed, lift the egg with a flipper, and score according to the lifted condition.

4. It repeats a total of 10 times, and this is defined as 1 cycle.

5. After the end of the first cycle, it is heated to 330 to 350°C for 30 minutes, and then washed.

6. The test ends when the score is 1, 3 times in a row.

At this time, the criteria for determining the score are as follows:

5 points; The fried egg is lifted up cleanly,

4 points; It requires a little force to lift the fried egg, but most of it is lifted.

3 points; When you lift the fried egg, part of it is torn, but most of it is lifted.

2 points; Half of the fried egg is lifted, and

1 point; Overall sticking occurs.

division Sample 1 Sample 2 Sample 3 Average Conventional ceramic coating 5 5.2 5.4 5.2 Textured coating 9 9.2 9.6 9.26

As shown in Table 1, it was confirmed that the non-adhesiveness was increased by 1.8 times compared to the conventional ceramic coated cookware.

Claims (20)

delete delete delete delete delete delete A primer coating composition for ceramic coating with a cast iron-like texture containing colloidal silica, methyltrimethoxysilane (MTMS), a silicone glycol copolymer, and an acid catalyst is applied to the entire or partial surface of an aluminum cookware to form a primer coating layer. A first step of forming;
A second step of forming a ceramic undercoat layer; And
Including a third step of forming a ceramic top coat layer,
In the first step, the primer coating composition contains 0.05 to 2% of the total weight of the silicone glycol copolymer,
The primer coating layer, the primer coating layer, and the top coating layer are sequentially stacked to provide a three-dimensional surface shape formed of a protruding structure formed by overlapping round particles without an intaglio structure formed by being recessed into the interior. Texture coating method.
delete The method of claim 7,
The primer coating layer formed from the first step has an average thickness of 15 to 30 μm and a roughness of ±15 μm, a cast iron-like texture coating method of an aluminum surface.
The method of claim 7,
The second step is to use a nozzle of a spray gun with a diameter of 0.8 to 1 mm,
At a pressure of 1.5 to 2 bar, it is carried out by spraying at a distance of 30 to 50 cm, the cast iron-like texture coating method of the aluminum surface.
The method of claim 7,
The ceramic undercoat layer formed from the second step is uniformly formed to a thickness of 15 to 25 μm on average to maintain the texture of the primer coating layer formed from the first step, the cast iron-like texture coating method of the aluminum surface.
The method of claim 7,
The ceramic top coat layer formed from the third step is uniformly formed to a thickness of 5 to 15 μm on average to maintain the texture of the primer coat layer formed from the first step, the cast iron-like texture coating method of the aluminum surface.
The method of claim 7,
The first to third steps are achieved in a wet-on-wet method sequentially performed in succession without a separate drying process, the cast iron-like texture coating method of the aluminum surface.
The method of claim 7,
The primer coating composition further comprises a filler, a pigment, or both, a cast iron-like texture coating method of an aluminum surface.
The method of claim 7,
The primer coating composition is composed of a composition A containing a colloidal silica sol, a composition B containing a MTMS and a silicone glycol copolymer, and a composition C containing an acid catalyst, a cast iron-like texture coating method on an aluminum surface.
The method of claim 15,
The composition A further comprises 0.5 to 1.5 times the weight of the filler, 0.25 to 1 times the weight of the pigment, or both, based on the weight of the colloidal silica sol contained therein, the cast iron-like texture coating method of the aluminum surface .
The method of claim 16,
The filler and the pigment are each independently having a size of 1 to 5 μm, the cast iron-like texture coating method of the aluminum surface.
The method of claim 15,
The composition A, composition B, and composition C are mixed in a ratio of 60 to 80: 20 to 35: 0.1 to 0.5 based on the weight of the cast iron-like texture coating method of the aluminum surface.
Formed by sequentially stacking on all or part of the surface of the aluminum cookware,
A primer coating layer having an average thickness of 15 to 30 μm and a roughness of ±15 μm;
A ceramic undercoat layer uniformly formed with an average thickness of 15 to 25 μm; And
A ceramic top coat layer uniformly formed with an average thickness of 5 to 15 μm;
Including,
The primer coating layer, the primer coating layer, and the top coating layer are sequentially stacked to provide a three-dimensional surface shape formed in a protruding structure formed by overlapping round particles without an intaglio structure formed by being recessed into the interior,
The primer coating layer is provided from a primer coating composition comprising 0.05 to 2% of the total weight of the silicone glycol copolymer, cast iron-like aluminum cookware having a texture.
The method of claim 19,
An aluminum cookware having a cast iron-like texture that includes only a ceramic undercoat layer and a ceramic topcoat layer formed to the same thickness, and has improved non-adhesiveness by 150 to 300% compared to an aluminum cookware without a primer coating layer.

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