JPH03227237A - Fluororesin-coated article with display of graduation, pattern or character - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a fluororesin coating with scales, patterns, characters, etc. displayed thereon, and more specifically, the present invention relates to a device in which a fluororesin coating is displayed with scales, patterns, characters, etc. This invention relates to a device in which scales, patterns, characters, etc. are displayed by changing the color of a temperature indicating material laminated on a substrate coated with a fluororesin.

``Prior Art J'' Conventionally, the only means for displaying scales or the like on a fluororesin coating was to physically create irregularities on the coating using a press or the like and utilize the shadows of the unevenness, that is, by stamping.

This is because the non-adhesive nature of the fluororesin makes it impossible to display scales or the like by printing on its surface.

Furthermore, even if this were possible, the non-adhesiveness of the printed area would be reduced, so when used in kitchen applications, for example, in the inner pot of a rice cooker, rice would stick to this area, which is not preferable.

[Problems to be Solved by the Invention] For these reasons, all inner pots of rice cookers have been marked with markings, but this method also has serious problems.

First, since the coating is deformed with a very large curvature at the stamped part, the fluororesin coating is also stretched at the same time, which tends to cause peeling of the adhesive interface with the substrate and the occurrence of pinholes and cracks in the coating. Moisture and rice soup may enter from these parts, causing corrosion of the substrate, peeling of the coating, discoloration, etc.

Second, the display is difficult to see because of the shadows caused by the unevenness.

Rice pots have become particularly multi-functional in recent years, and as a result, the scales and other markings are not only for rice cooking, but also for sekihan, ojiya, sticky rice, etc., and are engraved in 6 and 4 places. These problems are becoming more and more obvious.

In view of the above, the present invention has been developed to solve these problems.

``Means for Solving the Problems'' That is, the present invention laminates a compound (hereinafter referred to as a temperature indicating material) that irreversibly changes color when heated in a temperature range exceeding the sintering temperature of fluororesin on a substrate having unevenness. Then, the fluororesin coating formed by laminating a fluororesin composition thereon is locally heated to a temperature higher than the discoloration temperature of the temperature indicating material, thereby changing the color of the heated portion of the temperature indicating material and making it different in color from the unheated portion. This is a fluororesin coating displaying scales, patterns, characters, etc. that are characterized by having a difference in .

Note that the embodiments of the present invention include at least the following.

(a) The fluororesin coating displaying scales, patterns, characters, etc. of the present invention, characterized in that the substrate having irregularities is made of aluminum or aluminum alloy.

(b) The fluororesin coating displaying scales, patterns, letters, etc. of the present invention as described in (a) above, wherein the temperature indicating material is laminated on the surface of aluminum or aluminum alloy by a chemical film treatment method.

The present invention will be explained in detail below.

As a result of intensive studies on the above-mentioned conventional problems, the present inventors have laminated a compound (temperature indicating material) that irreversibly changes color when heated in a temperature range exceeding the baking temperature of fluororesin on a substrate having unevenness. By locally heating the fluororesin coating, which is formed by laminating a fluororesin composition thereon, to a temperature higher than the discoloration temperature of the temperature indicating material, the non-adhesive properties of the surface of the fluororesin coating are not reduced, and no damage is caused. They discovered that it is possible to change the color of the temperature indicating material in the heated part without physically damaging it, and came up with the idea of using this to display scales, patterns, letters, etc. based on the difference in color from the unheated part. As a result, we have completed the present invention.

"Function" The substrate with unevenness used in the present invention includes glass, ceramics, aluminum, aluminum alloy,
It may be made of stainless steel or a plywood thereof, but aluminum or an aluminum alloy whose surface has been roughened by chemical or electrochemical etching is particularly preferred.

C
Salts such as O, Ni, Fe, Cu, Cr, Mn, and Pb are preferably used, and typically, (NH4)MnP20
,,3(NH4)20・Al2O3・12MoO3・1
9H20,3(NH4)20-Fe203-12Mo0
3-19H20, 3(NH,)20-CrO3-12M
Examples include, but are not limited to, oO3.19H20.

Any method such as solution coating or vapor deposition may be used for laminating these layers, but when using metals such as aluminum, aluminum alloys, and stainless steel as the substrate, chemical film processing can be used to form thin layers of any thickness.
Moreover, it is more preferably used because it can be laminated with strong adhesive strength.

Examples of the fluororesin used in the present invention include polytetrafluoroethylene (PTFE) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP).
, 7-fluoroethylene-perfluoroalkyl vinyl ether (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), or ethylene-chlorotrifluoroethylene copolymer (ECTFE), etc. be.

Fluororesins are not only resin powders, but also include aqueous dispersions of fluororesins obtained by emulsion polymerization, dispersions of fluororesin powders dispersed in aqueous media, organosols of fluororesins, and emulsions of organosols in water. It can also be used in the form of

As the fluororesin composition to be laminated, pigments, adhesives, etc. are added as appropriate.

As for the heating method and heat source, heat transfer from metal moldings shaped like scales, patterns, letters, etc. may be used, and laser scanning may also be used, but any heating method that can raise a localized temperature to high temperature may be used. It is not particularly limited.

In any case, it is important that the fluororesin can be sintered at a temperature below the discoloration temperature of the temperature indicator, that the temperature indicator can discolor in a temperature range exceeding the sintering temperature, and that the fluororesin should not undergo decomposition or other denaturation.

"Example" Examples of the present invention will be described below.

Example 1: The treated surface of an aluminum alloy plate whose surface was roughened by electrochemical etching was coated with approximately 0.5 μm by chemical film treatment.
(NH4)MnP20. A purple substrate was obtained by forming a film. This was coated with an aqueous dispersion of 60% by weight of PTFE, and baked at 360° C. for about 15 minutes to obtain a fluororesin coating.

When a metal letterpress was heated to about 410° C. and brought into contact with the coated surface for about 30 seconds, the letters on the letterpress turned white, resulting in a clear display.

The surface of the coating was not modified at all.

Example 2: When the surface of the fluororesin coating obtained in the same manner as in Example 1 was scanned with a CO2 laser with an output of 200 W condensed to a diameter of approximately 100 μm, the irradiated area turned white and a clear display was observed. was gotten. The fluororesin surface was not damaged at all.

"Effects of the Invention" As explained above, according to the present invention, scales, patterns, characters, etc. can be displayed on a fluororesin-coated object, such as the inner pot of a rice cooker, without impairing the characteristics of the fluororesin coating. Easier to see than a stamp. Therefore, it can be widely used for displaying scales on kitchen utensils, writing instructions, creating patterns, etc.

In the present invention, the shape of the fluororesin-coated article is not particularly limited, and may of course be a finished product such as the inner pot of a rice cooker, or a fluororesin-coated aluminum plate.

Claims (1)

[Claims] (1) A compound that irreversibly changes color when heated in a temperature range exceeding the sintering temperature of the fluororesin (hereinafter referred to as temperature indicating material) is laminated on a substrate with unevenness, and a fluororesin composition is layered on top of it. It is characterized in that the laminated fluororesin coating is locally heated to a temperature higher than the discoloration temperature of the temperature indicating material, thereby changing the color of the heated portion of the temperature indicating material to create a color difference from the unheated portion. A fluororesin coating displaying scales, patterns, characters, etc.