JPH0596686A - Fluororesin covering - Google Patents

Abstract

PURPOSE:To improve transparency, water-repellent and noncohesive properties, adhesiveness to a base material and heat resistance by covering a glass base material such as glass-made pan or ceramic base material with a fluororesin film containing a predetermined weight percentage of FEP. CONSTITUTION:The plate glass produced from soda lime glass, phosphosilicate glass, etc., is tempered for reinforcement. The surface of the plate glass may be roughened by etching or blasting. It is degreased with methylethylketone. The powder or dispersion of the fluororesin containing at least 80wt.% of FEP (tetrafluoroethylene-hexanefluoropropylene copolymer) is produced. PFA or PTFE or the mixture thereof is incorporated in this fluororesin in an amount of at most 20wt.% to improve its heat resistance. The fluororesin solution is applied to the plate glas in a thickness of about 40mum and then sintered. This method can improve the transparency and water-repellent properties of a glass-made frying pan, the clad of optical fiber cable, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluororesin coating, more specifically, it imparts water repellency and non-adhesiveness to the surface of a glass substrate without significantly losing the transparency of the glass, and has strong adhesion and heat resistance. The present invention relates to a fluororesin coating having properties and a fluororesin coating which imparts water repellency and non-adhesiveness to the surface of a ceramic substrate and has strong adhesion and heat resistance.

[0002]

2. Description of the Related Art Conventionally, as a water-repellent, non-tacky article using a fluoropolymer, a fluorocarbon resin is coated on a metal substrate such as aluminum or stainless steel through a primer containing a binder such as polyamideimide. Things are common,
It is often used in kitchen applications such as frying pans, hot plates, and jar rice cooker inner pots. Particularly when aluminum is used as a base material, a method is often used in which a fluorine resin is physically adhered to the surface of the aluminum by providing fine irregularities by etching or the like without using such a primer.

As a coating for glass, a frying pan made of glass or a pot made of glass in which the cooking surface is coated with a fluororesin is commercially available. Both are black or dark brown coating, which is a feature of glass. It was a loss of transparency. Perhaps because of this problem, the fluororesin coating of the product group is limited to the bottom or side surface of the glass frying pan or pan, which is relatively lower than the side surface, and the side surface that allows the cooked food to be seen through from the outside. There is no coating on the upper part or the lid. Therefore, the washability of these cooking utensils was insufficient.

On the other hand, as a transparent coating on glass, a silicone or acrylic resin coating is often used for the purpose of protecting the glass surface and preventing scattering of fragments at the time of breakage.
These polymers are insufficient in water repellency and non-adhesiveness.
Also, the coatings for the windshields of automobiles were wax-like temporary. That is, the present situation is that no coating has been developed that imparts water repellency and non-adhesiveness to the glass surface without significantly deteriorating the transparency of the glass and has strong adhesion and heat resistance. Moreover, as a coating on ceramics, one having sufficient adhesive strength has not been obtained.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a glass substrate with water repellency, without significantly losing the transparency of the glass substrate.
It aims to provide a coating that is non-tacky, yet has strong adhesion and heat resistance, and is a kitchen article such as a glass frying pan, a glass pot, a window material such as a microwave oven or a toaster oven, Home appliances, office equipment such as toner boxes for copying machines, telephone box window materials, building materials such as high-rise building window materials, automobile side mirrors, automobile traffic safety equipment such as mirrors installed at intersections, optical fiber cable cladding or coating. It is intended to solve problems in a wide range of fields that require transparency, water repellency, non-adhesiveness, adhesiveness, and heat resistance. Needless to say, the present invention is also effective in applications where special transparency is not important, such as coating on ceramics or glass cloth.

[0006]

The invention of the present application is 80 wt.
% Of FEP or more is coated on a base material such as glass or ceramics to provide a fluororesin coating.

Note that at least the following is included as an embodiment of the present invention. (A) Fluorine resin with PFA or PTFE or PF
The fluororesin-coated article according to the present invention, which contains 20 wt% or less of a mixture of A and PTFE.

(B) The fluororesin-coated article according to the present invention, characterized in that the outermost layer is coated with a fluororesin such as PFA or PTFE.

The present invention will be described in detail below.

As the glass substrate used in the present invention, silicate glass such as soda lime glass, phosphosilicate glass, borosilicate glass and borosilicate low alkali glass, and quartz glass such as lead glass, barium glass and fluorine glass. However, it is not particularly limited. Also, those that have been strengthened by quenching can be used without any problems.

These glasses may be used as they are, or may be roughened by etching or blasting. However, in the present invention, it is not necessary to improve the adhesive strength by roughening. 、 Because the adhesive strength of the coating film is obtained,
Even if roughening is performed, it should be kept within a range where the transparency is not significantly lost when the coating is completed.
When coating glass, it is necessary to degrease and clean the surface with a solvent or alkali.

The ceramic substrate used in the present invention is not particularly limited and can be widely applied, and general ceramics such as pottery, porcelain, bricks and enamels and so-called fine ceramics can also be used. Similar to glass, ceramics do not require special surface treatment, but they are not excluded. In addition, degreasing and cleaning are necessary when coating.

The fluorine resin used in the present invention is PTF.
E (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE (tetrafluoroethylene-ethylene copolymer), CTFE (Polychlorotrifluoroethylene), PVdF (polyvinylidene fluoride) and their copolymers are used in the form of powder or dispersion.

For the purpose of enhancing the adhesiveness with the glass or ceramic substrate, at least 80 wt% of FEP is used.
% Or more must be added. In addition, for the purpose of increasing heat resistance, PFA is used as a fluororesin other than FEP in the fluororesin.
Alternatively, it is preferable to use PTFE or a mixture thereof in the range of 20 wt% or less.

As a processing method, the above resin mixture is applied onto a base material and dried and sintered.

Considering the characteristics of each material, a multilayer structure may be used. Specifically, FEP with good adhesion to the first layer
100% layer, PFA or P with good heat resistance for the second layer
The structure is such that TFE or a mixture thereof is applied. If necessary, carbon black, titanium oxide, mica, colored mica, conductive filler, etc. may be mixed and used in the resin.

[0016]

EXAMPLES Examples of the present invention will be described below. Examples 1 and 2 and Comparative Examples 1 to 5 The surface of a sheet glass (float glass made by Central Glass: see Table 1) that has been strengthened by quenching is MEK.
After thoroughly degreasing with (methyl ethyl ketone), apply the fluororesin dispersion liquid to a thickness of about 40μ, and apply at about 1 ° C at 150 ° C.
After drying for 0 minutes, the resin was sintered at 400 ° C. for about 20 minutes. An average coating film of about 20μ was obtained.

Initial evaluations of the adhesive strength, transparency, contact angle to water between the glass substrate and the coating film of the obtained fluoropolymer coating and the evaluation after the heat aging test were carried out. The results are shown in Table 2. The evaluation method is as follows.

(Peeling strength) A commercially available FEP sheet was heat-fused on the surface of a coating film, and then peeled in a direction of 180 ° with a width of 1 cm, and the peeling force at that time was measured as peel strength (unit: kg / c).
m).

(Cross-cut test) JISK on the coated surface
5400-1990, grid pattern 1 specified in 8.5.2.
Make 00 Masu, and attach Cellotape (Nichiban Co., Ltd.) to this surface sufficiently and peel it off immediately. This peeling is performed 40 times with a new cellophane tape, and 100 pieces of the tape are evaluated to evaluate how much remains.

(Visible light transmittance) 400 to 700 using a UV / visible spectrophotometer (U-3400 manufactured by Hitachi, Ltd.)
Ratio of integral values of visible light transmittance of nm (1
00%. ) Is the visible light transmittance. The transmittance of the glass plate used as the base material was 90%.

(Contact angle to water) Using a contact angle meter manufactured by Kyowa Interface Science Co., Ltd., the contact angle to pure water is determined by the droplet method.

(Comprehensive Evaluation) A practical adhesive strength of about 0.
Adhesive strength of 5 kg / cm or more, 80/100 in a cross-cut test
It is presumed that the residual rate is required, and the visible light transmittance at a film thickness of about 10μ, which is estimated to be the minimum required, is subjected to a sensitivity test (1 year old boy, 1 year old boy, 1 year old boy 1 person, Approximately 50% or more of the 40-year-old boys and the 20-year-old girls (3) felt that the transparency was good.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

As described above, according to the present invention, water repellency and non-adhesiveness are imparted to the glass surface without significantly deteriorating the transparency of the glass substrate, and strong adhesion and heat resistance are provided. Since it is possible to obtain a coating having, it is possible to use glass frying pans, glass pots, kitchen supplies such as window materials such as microwave ovens and oven toasters, home appliances, office equipment such as copier toner boxes, telephone box window materials, Building materials such as high-rise building windows, automobile side mirrors, automobile traffic safety equipment such as mirrors installed at intersections, clad or coating of optical fiber cables, water repellency or non-adhesiveness,
It can be applied to a wide range of fields where adhesion or heat resistance is required. Needless to say, the present invention can be effectively applied to applications in which transparency is not particularly important, such as coating on ceramics or glass cloth.

Claims (1)

[Claims] 1. A fluororesin coating characterized by comprising a fluororesin containing 80 wt% or more of FEP coated on a substrate such as glass or ceramics.