JPS63268636A - Coated metal plate having excellent sliding characteristics for snow - Google Patents

Abstract

PURPOSE:To improve sliding characteristics for snow, by setting pigment-added fluororesin layer where the thickness of the layer and the max. particle size of the pigment added are specified, and further thereon a fluororesin layer free of pigment where the thickness and the center line average roughness of the surface are specified, and fusing these two layers to constituting a coated metal plate. CONSTITUTION:A pigment-added fluororesin layer 2 where a pigment whose max. particle size is 5mum or less is added and the thickness of the layer is 10mum or more is adhered on a metal plate 1 and a pigment free fluororesin layer 3 where no pigment is added and the thickness of the layer is 2mum or more is thereon adhered. The center line average roughness of the surface of the fluororesin layer 3 free of pigment is 0.6mum or less. The layer 3 and the layer 2 are fused together. Resins where tetrafluoroethylene resin, trifluoroethylene resin, fluorovinylidene resin and so on are contained as main components can be used as the fluororesin layer constituting the layer 2 and the layer 3. The above described constitution gives a roofing material having excellent sliding characteristics for snow where snow can slide down by its dead-weight when the angle of roof slope is 15-20 deg. and having good durability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a snow sliding system that is capable of sliding snow accumulated on roofs in areas with heavy snowfall, such as the regions along the Sea of Japan, by its own weight, and has excellent durability. The present invention relates to coated metal plates with excellent properties.

[Prior art]

BACKGROUND ART The physical and mental fatigue and burden on residents caused by removing snow that has accumulated from rooftops in areas with heavy snowfall in Japan's Sea of Japan region has become a major social problem.

This is because the snow that has accumulated on the roof is removed mainly by manual labor.

In order to relieve the physical and mental fatigue and burden on residents associated with removing snow that has accumulated on rooftops in areas with heavy snowfall in Japan's Sea of Japan region, it is necessary to remove snow that has accumulated on rooftops without relying on human power. The snow can be removed by melting the snow or by applying some kind of energy to the snow that has accumulated on the roof and making it fall from the roof, but in this way, equipment is provided to melt or fall the snow that has accumulated on the roof. However, even if expensive equipment is installed, it is only used a few times a year, and even though it is used very infrequently, the maintenance and management costs are high. This had the disadvantage of significantly increasing the economic burden.

[Problem that the invention seeks to solve]

Therefore, the present inventors believe that in order to eliminate the physical and mental fatigue and burden on residents associated with removing the snow that has accumulated on the roof, it is possible to remove the snow that has accumulated on the roof without relying on human power. We focused on the idea that it would be better if it were dropped automatically.

However, conventionally, galvanized steel sheets coated with polyester resin paint or silicone polyester resin paint are mainly used as roofing materials in areas with heavy snowfall, but coated steel sheets such as Niku et al. The snow sliding performance of the roof is not very good even in the initial state after roofing is completed, and the paint film deteriorates over time due to ultraviolet rays from sunlight, and the pigments added to the paint film are exposed on the surface of the paint film. After 3~
The problem was that after four years, the snow sliding performance had deteriorated to the point where it was no longer a problem.

Therefore, in recent years, fluororesin-coated metal plates have been used, which have excellent weather resistance and durability, and have superior snow sliding performance compared to coated metal plates coated with conventional polyester resin paints or silicone polyester resin paints. Construction methods in which roofing materials are used to cover roofs, and construction methods in which fluororesin films are pasted onto roofing materials have come into use. However, even if the construction method of roofing using such fluororesin coated metal sheets or the construction method of pasting fluororesin film on the roofing material, the general 15°~ There is a problem in that snow accumulated on a roof with an inclination angle of 20 degrees cannot be automatically dropped from the roof due to its own weight.

Means for Solving Problem C] In order to eliminate the drawbacks of such conventional roofing materials, the present inventors have developed a coated metal plate coated with a polyester resin paint or a silicone polyester resin paint, which has excellent durability. As a result of various experiments and studies on fluororesin-coated metal plates, which have superior snow sliding performance compared to conventional fluororesin-coated metal plates, we have found that conventional fluororesin-coated metal plates can be coated with fluororesin coatings due to the ultraviolet rays of sunlight. Snow accumulation caused by pigments added to prevent the fluororesin coating from peeling off from the underlying metal plate due to deterioration of the bonding strength with the underlying metal plate, as well as for the purpose of coloring and increasing the amount. It was determined that snow sliding performance is hindered by frictional resistance with the fallen snow.

Therefore, the inventors of the present invention have added a pigment-added fluororesin-based layer of a predetermined thickness or more to the lower layer in order to impart durability, and further added pigments to provide good snow sliding properties on the lower layer. A pigment-free fluororesin layer having a thickness of at least a predetermined thickness is fixed, and the pigment-added fluororesin layer is fixed to the upper surface of the pigment-free fluororesin layer so as not to deteriorate the surface texture of the pigment-free fluororesin layer fixed to the upper surface thereof. The maximum particle size of the pigment to be added is 5
- The pigment-free fluororesin layer has a center line average roughness Ra of 0.67 or less, and the pigment-free fluororesin layer has a surface centerline average roughness Ra of 0.67 so that it has sufficient snow sliding performance even on a roof with an inclination angle of 15 to 20 degrees.
a or less, and both fluororesin layers are fused by baking or hot pressing so that the pigment-free fluororesin layer does not peel off from the pigment-added fluororesin layer below. By elucidating the positive aspects, the present invention was completed.

In other words, the present invention provides a metal plate having a pigmented fluororesin layer with a thickness of 10- or more in which a pigment with a maximum particle size of 51 m or less is added, and a 2- or more pigment-added fluororesin layer on which no pigment is added.
A pigment-free fluororesin-based layer having a thickness of at least 100% is fixed, and the pigment-free fluororesin-based layer has a center line average roughness Ra of 0.6 or less on its surface, and the pigment-free fluororesin layer has a surface centerline average roughness Ra of 0.6- or less, and The present invention relates to a coated metal plate having excellent snow sliding properties, characterized in that a resin layer and the pigment-added fluororesin layer below the layer are fused together.

The coated metal plate with excellent snow sliding properties according to the present invention will be explained in detail below with reference to one drawing.

The drawing is an explanatory sectional view schematically showing one embodiment of the structure of a coated metal plate having excellent snow sliding properties according to the present invention.

In the drawing, 1 is a metal plate serving as a base material, which is a stainless steel plate or a galvanized steel plate without pretreatment.

Metal plates such as aluminum plates, metal plates that have undergone pre-treatment such as chromate treatment, and metal plates that have been subjected to or have not been subjected to these pre-treatments and are coated with a primer. 2 is a pigment with a thickness of 10 mU or more that is fixed to the surface of the metal plate 1 and has a maximum particle size of 5 pm or less. It is an added fluororesin layer.

The type of pigment added and the amount of pigment added are the same as those for conventional fluororesin paints and films, and generally the amount of pigment added is 30 to 45 parts per 100 parts of resin. The reason why the maximum particle size of the pigment added to this pigmented fluororesin layer 2 must be 51 m or less is because if the particle size of the pigment becomes larger than 5 pm, the surface roughness of the pigmented fluororesin layer 2 will increase. The center line average roughness Ra is small enough to impart good snow sliding properties to the surface of the non-pigmented fluororesin layer, which is further formed on the pigmented fluororesin layer 2 and is further formed on the pigmented fluororesin layer 2. The reason why the thickness must be 10 or more is because if the thickness is less than 10, the metal plate 1 and the pigmented fluororesin layer 2 will stick together due to the ultraviolet rays of sunlight. The joint strength of the pigmented fluororesin layer 2 deteriorates over time.
This is because a phenomenon occurs in which the metal plate 1 peels off from the metal plate 1, causing a problem in durability. The methods of fixing this pigmented fluororesin layer 2 to the metal plate 1 include a method in which a pigmented fluororesin paint is applied as the pigmented fluororesin layer 2 and then baking is performed; 2, a pigmented fluororesin film is used and the film is fused to the metal plate 2 by hot pressing; Either of the methods of using a film and bonding this film with an adhesive can be adopted. Reference numeral 3 denotes a pigment-free fluororesin layer with a thickness of 2 or more to which no pigment is added, which is fixed on the pigment-added fluororesin layer 2; The center line average roughness Ra of the surface is 0.
6- or less and must be fused to the pigmented fluororesin layer 2 of the upper layer. The thickness of this pigment-free fluorine resin layer 3 must be 2 mm or more because if the thickness is less than 2 mm, accumulated snow will slide on the top surface of the layer and cause wear and tear, reducing durability. This is because, in addition to dealing with this, it is difficult to reduce the centerline average roughness Ra of the surface to 0.6 or less due to the unevenness caused by the pigment added to the pigmented fluororesin layer 2. Furthermore, the center line average roughness Ra of the surface of the pigment-free fluororesin layer 3 must be 0.61 m or less, because if the center line average roughness Ra of the surface becomes larger than 0.6, snow will accumulate. The snow sliding performance is reduced, and snow accumulated on roofs with a normal minimum slope angle of 15° to 2G'' with respect to the horizontal plane in areas with heavy snowfall, such as areas along the Sea of Japan, can fall due to its own weight. This is because the present inventors have clarified through numerous experiments that this cannot be done.Furthermore, a pigmented fluororesin layer with a thickness of 10 mm or more to which a pigment with a maximum particle size of 5 mm or less as described above is added. The pigment-free fluororesin layer 2 and the pigment-free fluororesin layer 3 having a thickness of 2 or more and having no added pigment thereon must be fixed by fusion.

If this fixing method is performed by a method other than fusion, the bonding strength of the fused portion between the pigmented fluororesin layer 2 and the non-pigmented fluororesin layer 3 will deteriorate over time due to ultraviolet rays from sunlight. As a result, a phenomenon occurs in which the pigment-free fluororesin layer 3 peels off from the pigment-added fluororesin layer 2, causing a problem in durability.

The fluororesin layers constituting the pigmented fluororesin layer 2 and the non-pigmented fluororesin layer 3 include tetrafluoroethylene resin, trifluoroethylene resin, vinylidene fluoride resin, and vinyl fluoride resin. Resins whose main components are resins such as ethylene-tetrafluoroethylene resins can be used.
The above-mentioned fluororesin, which is the main component of the pigment-added fluororesin layer 2 and the pigment-free fluororesin layer 3, can be of the same composition or of different compositions. As for the method of fusing to the pigment-added fluororesin layer 2 in step 3, if a pigment-free fluororesin paint is used as the pigment-free fluororesin layer 3, the pigment in the lower layer as-applied. A pigment-free fluororesin paint is applied on the pigmented fluororesin layer 2, which is made of either an additive fluororesin paint, a coated and baked pigmented fluororesin paint, or a fixed pigmented fluororesin film. In addition, if a pigment-free fluororesin film is used as the pigment-free fluororesin layer 3, the coating and baking applied pigment-added fluororesin paint is the lower layer. Alternatively, a non-pigmented fluororesin film is placed on the pigmented fluororesin layer 2 made of the fixed pigmented fluororesin film and fused onto the lower pigmented fluororesin layer 2 by hot pressing. methods can be adopted.

(Function) The coated metal sheet with excellent snow sliding properties according to the present invention as described above is used as a roofing material whose minimum angle of inclination with respect to the horizontal plane is usually in the range of 151 to 201 in areas with heavy snowfall such as the Sea of Japan region. Then, since the top layer is composed of a pigment-free fluororesin layer 3 with a thickness of 2 or more, it not only has excellent durability, but also has no pigment and has a center line average roughness of its surface. Since the surface Ra is 0.6p or less, the snow that has accumulated on the roof has very good sliding properties, and even if the slope angle of the roof surface is as small as 15" to 20", the snow will not accumulate on the roof due to its own weight. Moreover, the lower layer of this top layer, pigment-free fluororesin layer 3, is a layer with a thickness of 10 or more and containing a pigment with a maximum particle size of 5 or less. Since the pigmented fluororesin layer 2 is fused with the non-pigmented fluororesin layer 3, the coating film is durable without deterioration or peeling caused by direct sunlight, especially ultraviolet rays, in spring and summer when it is not snowing. This creates a roofing material that is rich in character.

〔Example〕

Examples 1-4. Conventional Example and Comparative Example As an example and a comparative example, a stainless steel plate (sUs304) with a thickness of 0.3 ma+ and a galvanized steel plate with a thickness of 0.35 mm were each subjected to chromate treatment, and the chromate treatment was applied to each of them as shown in Table 1. After forming a primer layer by applying it with a roll coater and drying it with hot air, apply a resin paint containing the pigments shown in Table 1 on top of it with a roll coater and drying it with hot air to form an intermediate coat layer. Then, a resin coating shown in Table 1 was applied thereon using a roll coater and dried with hot air to form an overcoat layer to produce a coated metal plate. Here, care was taken to ensure that the centerline average roughness Ra of each surface of the coated metal plate having excellent snow sliding properties according to the present invention was 0.6- or less.

Here, what is the primer for Uniflon? Nippon Paint■
Uniflon is a primer paint containing an anti-corrosion pigment and an extender pigment whose main component is epoxy resin manufactured by Nippon Paint. What is UNIFLON K (Clear), a fluororesin-based paint containing Nippon Paint ■? A transparent fluororesin-based paint that does not contain coloring pigments or extender pigments in the above-mentioned UNIFLON K, which is made of Nippon Paint's vinylidene fluoride resin as its main component and mixed with acrylic resin. It's paint.

In addition, as a comparative example, a chromate-treated stainless steel sheet (SO5304) with a thickness of 0.31 mm and a galvanized steel sheet with a thickness of 0.35 mm were coated with a fluororesin paint and a polyester paint outside the scope of the present invention. A coated metal plate is manufactured by applying a paint with a roll coater and drying with hot air to form an intermediate coat layer and an undercoat layer.

In addition, conventional coated metal plates were also prepared.

We observed the coefficient of kinetic friction between deaerated distilled water and solidified ice from one direction before and after the weather resistance test of each of these coated metal plates, and the state of the coating after the weather resistance test.
Shown in the table.

From this result, it was found that the coated metal plate with excellent snow sliding properties according to the present invention is a coated metal plate with excellent weather resistance and snow sliding properties.

Below are blank spaces Examples 5 to 12 A single layer of brimer shown in Table 1 was applied using a roll coater on a stainless steel plate (SUS304) with a thickness of 0.3-Peng and a galvanized steel plate with a thickness of 0.35m5, respectively, and dried with hot air. A fluororesin film to which the pigments listed in Table 2 have been added is placed on top of the fluororesin film, and a fluororesin film to which the pigments shown in Table 2 are not added is placed on top of the fluororesin film. A pressure cuff kg/a11. A coated metal plate was manufactured by fusion bonding by hot pressing under conditions of pressurization time of 1.5 minutes.

Here, YMAR720 refers to vinylidene fluoride resin films that may or may not contain pigments manufactured by Mitsubishi Yuka SSt, and Tetra refers to films that may or may not contain pigments manufactured by DuPont. The centerline average roughness Ra of the surface of these fluorinated resin films is 0.5- or less, and the centerline average roughness Ra of the surface after hot pressing is is 1.5
- less than or equal to

The coefficient of kinetic friction between degassed distilled water and ice solidified from one direction before and after the weather resistance test of each of these coated metal plates and the state of the coating after the weather resistance test were determined, and the results are also shown in the second section.
From the results shown in Table 8, it was found that the coated metal plate with excellent snow sliding properties according to the present invention is a coated metal plate with excellent weather resistance and snow sliding properties.

The following margin [Effects of the Invention] The coated metal plate with excellent snow sliding properties according to the present invention as detailed above has a composition of to4 or more in which a pigment with a maximum particle size of 5 or less is added to the metal plate. A pigment-added fluororesin layer with a thickness of It has a simple structure in which the center line average roughness Ra of the surface is 0.6- or less, and the pigment-free fluororesin layer and the pigment-added fluororesin layer below it are fused. Despite this, it not only has excellent snow sliding properties but also excellent durability, making it possible to manually remove snow from roofs, which had previously caused physical and mental fatigue and strain on residents, which had become a major social problem. This is a revolutionary coated metal plate that can be applied without the need for any additional steps, and its value is extremely high.

[Brief explanation of the drawing]

The drawing is an explanatory sectional view schematically showing one embodiment of the structure of a coated metal plate having excellent snow sliding properties according to the present invention. In the drawings 1...Metal plate 2...Pigmented fluororesin layer 3...
Pigment-free fluororesin layer・no・kono

Claims (1)

[Scope of Claims] 1. A pigmented fluororesin layer with a thickness of 10 μm or more in which a pigment with a maximum particle size of 5 μm or less is added to a metal plate,
Furthermore, a pigment-free fluororesin layer with a thickness of 2 μm or more is fixed thereon, and the pigment-free fluororesin layer has a centerline average roughness of its surface Ra.
A coated metal plate having excellent snow sliding properties, characterized in that the pigment-free fluororesin layer and the pigment-added fluororesin layer below it are fused together. 2. The coated metal plate with excellent snow sliding properties according to claim 1, wherein the metal plate is a metal plate whose surface has been pretreated. 3. A coated metal plate with excellent snow sliding properties according to claim 1 or 2, wherein the metal plate has an undercoat primer layer formed on its surface. 4. A coated metal plate with excellent snow sliding properties according to any one of claims 1 to 3, wherein the pigmented fluororesin layer is fixed to the metal plate with an adhesive. 5. A coated metal plate with excellent snow sliding properties according to any one of claims 1 to 3, wherein the pigmented fluororesin layer is fixed to the metal plate by fusion. 6. Excellent snow sliding properties according to any one of claims 1 to 5, wherein the pigmented fluororesin layer and the non-pigmented fluororesin layer have the same resin main components. Painted metal plate. 7 Claim 1 in which the main components of the resins of the pigmented fluororesin layer and the non-pigmented fluororesin layer are different
The coated metal plate having excellent snow sliding properties according to any one of items 1 to 5. 8 The fluororesin layer constituting the pigmented fluororesin layer is made of any one of tetrafluoroethylene resin, trifluoroethylene resin, vinylidene fluoride resin, vinyl fluoride resin, and ethylene-tetrafluoroethylene resin. A coated metal plate having excellent snow sliding properties according to any one of claims 1 to 7, which is a resin containing as a main component. 9 The fluororesin layer constituting the pigment-free fluororesin layer is made of tetrafluoroethylene resin, trifluoroethylene resin,
Vinylidene fluoride resin, vinyl fluoride resin, ethylene-
The coated metal plate with excellent snow sliding properties according to any one of claims 1 to 7, which is a resin whose main component is any one of tetrafluoroethylene resins.