JPH067738A - Heat-resistant and non-tacky film - Google Patents

Abstract

PURPOSE:To attempt to improve heat-resistant adhesiveness by preparing an undercoat with a silicone resin coating and a topcoat with a tetrafluoroethylene resin coating dispersed in an org. solvent and curing them in a non-tacky film formed on a metal surface. CONSTITUTION:An undercoat is performed with a silicone resin coating wherein e.g. a methylphenyl silicone varnish is compounded with a tetrafluoroethylene resin powder, isopropyl alcohol, toluene, a carbon black, a silica powder and a talc and the mean particle diameter is made 1-100mum. 10-60% flake pigment are incorporated in the solid content of this coating. Then, a tetrafluoroethylene resin coating contg. 50 pts. tetrafluoroethylene resin powder and 5-50 pts. silicone resin is topcoated. Then, it is cured at a specified temp. to form a heat-resistant non-tacky film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant and non-adhesive film formed on a metal surface and having both heat resistance and non-adhesiveness.

[0002]

2. Description of the Related Art Conventionally, for applications in which heat resistance and non-adhesiveness are required, coatings containing silicone resin as a main component or tetrafluoroethylene resin as a main component have been coated. It is being appreciated.

[0003]

However, although the one using the silicone-based resin has excellent heat-resistant adhesiveness to the substrate, the non-tackiness has not yet been satisfactory. Further, although the tetrafluoroethylene resin is excellent in non-adhesiveness but poor in adhesiveness, it is the current situation that sufficient heat resistant adhesiveness is not obtained although an undercoat is used.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve such a conventional problem, and provides a heat-resistant non-adhesive film coating having good adhesion even at 300.degree.

[0005]

Means for Solving the Problems According to the present invention, a coating material, in which an undercoat is a silicone resin paint and an overcoat is a tetrafluoroethylene resin paint dispersed in an organic solvent, is applied to a metal surface and simultaneously baked. The present invention relates to a heat resistant non-adhesive coating.

The heat-resistant non-adhesive film of the present invention is made non-tacky by using a silicone resin coating having excellent heat-resistant adhesion as an undercoat and further using a tetrafluoroethylene resin coating as an overcoat. At this time, since the undercoating silicone resin paint is an organic solvent-based paint, it is important that the topcoating tetrafluoroethylene resin paint is an organic solvent-based paint dispersed in an organic solvent, which is different from usual. As a result, a heat-resistant non-adhesive film having good adhesion between the undercoat and topcoat can be obtained.

The silicone resin paint of the present invention comprises a straight silicone resin or a modified silicone resin as a binder, and a color pigment, an extender pigment, an organic solvent, an additive and the like. As the color pigment, carbon black, organic pigment, metal powder, metal oxide or the like is used. Mica powder, talc, silica powder, calcium carbonate, etc. are used as extender pigments, and among them, scaly pigments such as mica powder and talc are important for modifying the coating performance and have an average particle size. The heat resistance and corrosion resistance of the coating film are increased by mixing the scaly pigment of 1 to 100 μm in the coating solid content at a rate of 10% to 60%. These resins, coloring pigments and extender pigments may be dispersed in an organic solvent, and if necessary, a curing agent, a dispersant and an antisettling agent may be added.

The top-coating tetrafluoroethylene resin paint is an organic solvent-based paint in which tetrafluoroethylene resin powder is dispersed in an organic solvent, and if necessary, the same coloring pigments, extender pigments and additives as in the undercoating are added. You can Furthermore, since it is an organic solvent paint, it is possible to add a straight silicone resin or a modified silicone resin, which further improves the interlayer adhesion with the undercoat and prevents mud cracks during drying. If the content of the silicone-based resin is in the range of 5 to 50 parts with respect to 50 parts of the tetrafluoroethylene resin, the effect can be obtained without causing a decrease in non-adhesiveness, which is a practical problem.

The coating of these paints can be carried out by a usual coating method. Immediately after coating the base coat with 2 to 50 μm or after drying at a predetermined temperature, apply the top coat with 1 to 50 μm and bake at the same time.

[0010]

EXAMPLES Examples of the present invention will be described below. Manufacturing example of paint Manufacturing example 1 Methylphenyl silicone resin varnish (solid content 60%)
100g, carbon black 2g, silica powder 7g, talc 3g, tetrafluoroethylene resin powder 1g, toluene 28
g, isopropyl alcohol 8g, organic bentonite 1
dispersed in a Sentry Mill for 1 hour to give an average particle size of 25
μm. This is hereinafter referred to as "undercoat 1".

Production Example 2 Methylphenyl silicone resin varnish (solid content 60%)
90 g, carbon black 2 g, mica powder 10 g, silica stone powder 2 g, potassium titanate fiber 2 g, talc 1 g, toluene 2
9 g, isopropyl alcohol 8 g, and organic bentonite 1 g were dispersed in a Sentry mill for 1 hour to give an average particle size of 2
It was 5 μm. This is hereinafter referred to as "undercoat 2".

Production Example 3 30 g of tetrafluoroethylene resin powder and carbon black 1
g, mica powder 5 g, toluene 58 g, diacetone alcohol 5 g, and a dispersant 1 g are dispersed in a Sentry mill for 1 hour,
The average particle size was 5 μm. This is hereinafter referred to as "topcoat A".

Production Example 4 25 g of tetrafluoroethylene resin powder, 10 g of methyl silicone resin varnish (solid content 50%), carbon black 1
g, mica powder 5 g, toluene 53 g, diacetone alcohol 5 g, and dispersant 1 g were dispersed in a Sentry mill for 1 hour to have an average particle diameter of 5 μm. This is referred to below as "Topcoat B"
Say.

Example 1 "Undercoat 1" was formed into a film having a thickness of 2 using an ordinary air spray coating machine.
Paint to 0 μm, leave at 20 ° C. for 3 minutes, then apply “top coat A” to a thickness of 3 μm, and apply at 380 ° C. for 1 min.
It was baked for 5 minutes. The base material is a standard stainless steel plate (SUS-
304) was used. The test results are shown in Table-1 and Table-2.

Example 2 "Undercoat 1" was made to a thickness of 2 using a conventional air spray coating machine.
The coating was applied to 0 μm, left at 20 ° C. for 3 minutes, and then “top coating B” was applied to a thickness of 15 μm, and baked at 380 ° C. for 15 minutes. The base material is a standard stainless steel plate (SUS
-304) was used. The test results are shown in Table-1.

Example 3 "Undercoat 1" was formed into a layer having a thickness of 2 using a conventional air spray coating machine.
Paint to 0 μm, bake at 380 ° C. for 15 minutes, and then apply “top coat B” to a thickness of 15 μm.
Baking for 15 minutes at 0 ° C. A standard stainless steel plate (SUS-304) was used as the base material. The test results are shown in Table-1.

Example 4 "Undercoat 2" was applied to a thickness of 2 with an ordinary air spray coating machine.
Paint to 0 μm, leave at 20 ° C. for 3 minutes, then apply “top coat A” to a thickness of 3 μm, and apply at 380 ° C. for 1 min.
It was baked for 5 minutes. The base material is a standard stainless steel plate (SUS-
304) was used. The test results are shown in Table-2.

Comparative Example 1 "Undercoat 1" was applied to a thickness of 2 with an ordinary air spray coating machine.
The coating was applied so as to have a thickness of 0 μm, and the coating was left at 20 ° C. for 3 minutes, then the “top coat A” was applied so as to have a thickness of 15 μm, and baked at 380 ° C. for 15 minutes. The base material is a standard stainless steel plate (SUS
-304) was used. The test results are shown in Table-1.

Comparative Example 2 "Undercoat 1" was applied to a thickness of 2 using an ordinary air spray coating machine.
It is coated to 0 μm and baked at 380 ° C. for 15 minutes, then “Topcoat A” is coated to a thickness of 3 μm and 380
It was baked at 15 ° C for 15 minutes. The base material is a standard stainless steel plate (S
US-304) was used. The test results are shown in Table-1.

Comparative Example 3 "Undercoat 1" was applied to a thickness of 2 with an ordinary air spray coating machine.
After coating to 0 μm and leaving it at 20 ° C. for 3 minutes, a water-based tetrafluoroethylene resin paint (E produced by Daikin Industries, Ltd.
K4209BK) to a thickness of 15 μm,
It was baked at 380 ° C. for 15 minutes. A standard stainless steel plate (SUS-304) was used as the base material. The test results are shown in Table-1.

Comparative Example 4 "Undercoat 1" was applied to a thickness of 2 using an ordinary air spray coating machine.
After coating so as to have a thickness of 0 μm and baking at 380 ° C. for 15 minutes, a water-based tetrafluoroethylene resin coating material (EK4209BK manufactured by Daikin Industries, Ltd.) was applied so as to have a thickness of 15 μm and baking at 380 ° C. for 15 minutes. A standard stainless steel plate (SUS-304) was used as the base material. The test results are shown in Table-1.
Shown in.

Comparative Example 5 Commercially available fluorine resin based undercoat (manufactured by Daikin Industries, Ltd.
EK-1109BK) with an ordinary air spray coating machine to a thickness of 8 μm, and after baking at 380 ° C. for 10 minutes, a water-based tetrafluoroethylene resin coating (DK4209BK manufactured by Daikin Industries, Ltd.) is formed with a thickness of 15 μm. The coating was applied as described above and baked at 380 ° C. for 15 minutes. A standard stainless steel plate (SUS-304) was used as the base material. The test results are shown in Table-2.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

As described above, the heat-resistant non-adhesive film coating of the present invention provides a non-adhesive film excellent in heat-resistant adhesion to a substrate even at 300 ° C. Frying pan, microwave oven wall, gas table top,
It can be used for kitchen products such as soup saucers.

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Claims (3)

[Claims] 1. A heat-resistant non-adhesive film obtained by applying a coating material comprising a silicone resin coating as a base coating and a tetrafluoride ethylene resin coating dispersed in an organic solvent as a top coating on a metal surface and simultaneously firing the coating. 2. The heat-resistant non-adhesive film according to claim 1, wherein the undercoat is a silicone resin paint containing a scaly pigment having an average particle size of 1 to 100 μm in a proportion of 10% to 60% in the solid content of the paint. . 3. The heat-resistant non-adhesiveness according to claim 1 or 2, wherein the top coat is a tetrafluoroethylene resin coating containing 5 to 50 parts of a silicone resin with respect to 50 parts of a tetrafluoroethylene resin. Film.