JP2003200107A - Coated metal plate excellent in vermin repellency - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated metal plate having vermin repellency without deteriorating the coating physical properties such as luster, processibility and the like by selecting a specified insecticide to be added to the coating material. <P>SOLUTION: A coating mixed with a pyrethroid type insecticide having the amount of reduction at the time of heating at 300°C less than 50% by weight on the basis of the efficacious component is formed on the outermost layer of a coated metal plate bearing a coating by baking. A coating mixed with 0.05-5 parts by weight of a pyrethroid type insecticide to 100 parts by weight of solid matter of a coating material and containing a filler such as a pigment is preferred. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated metal sheet which is suitable for use in a place where living pests such as cockroaches, mosquitoes and termites are easily generated and nesting and which is excellent in living pest repellent.

[0002]

2. Description of the Related Art Conventionally, kitchen appliances such as a sink, a gas table, and a stove with a large amount of food waste in a house and an electric circuit of a home appliance such as a refrigerator, a washing machine, and a microwave oven that generate warm air during use, or in the vicinity thereof. Moreover, domestic pests such as cockroaches prefer to nest, which is a problem in terms of hygiene and safety. In recent years, air-tightening of buildings and the use of air-conditioning equipment have become widespread due to changes in housing styles, resulting in poor indoor ventilation, which makes it easier for moisture to accumulate in costume dances, the back of cabinets, and gaps. For this reason, the gaps and the like have become an environment preferred by living pests.

[0003]

In the insect repellent treatment of a coated metal plate used in such a place, conventionally, a molded product is sprayed or coated with an insect repellent. Most of the insect repellents that are effective are exhibited by the sublimation of the drug, and therefore, there are many concerns that the inhalation may be harmful to the human body. Also, surface friction during use,
The pest repellent cannot be maintained for a long period of time because of the dropout of chemicals such as washing with water. Further, there are problems such as gloss and color change of the surface of the coated metal plate due to the influence of the insect repellent and the solvent.

When these sublimable insect repellents are directly blended with a paint, problems such as evaporation at the time of baking, reduction of efficacy due to thermal decomposition, coloring of resin, generation of offensive odor during work, and change in physical properties of coating film occur. Come on. Particularly when the baking temperature is 200 ° C. or higher, the insect repellent is greatly affected by the temperature. The present invention has been devised in order to solve such a problem, selecting a specific insect repellent to be mixed in the paint,
It is an object of the present invention to provide a coated metal plate that exhibits life pest repellent properties without deteriorating coating film physical properties such as gloss and processability.

[0005]

The coated metal sheet of the present invention which is excellent in repelling live insects is a coated metal sheet on which a baked coating film is formed in order to achieve its object. Weight loss during heating is 50% by weight of active ingredient
It is characterized in that a coating film containing a pyrethroid insect repellent which is less than the above is formed. As the outermost layer coating film, it is preferable to add 0.05 to 5 parts by mass of a pyrethroid insect repellent to 100 parts by mass of the solid content of the paint. The outermost layer coating film preferably contains various fillers such as pigments.

[0006]

The pyrethroid insect repellent is said to exert an action of inhibiting ion permeability of the nerve membrane by direct contact with the worm body and oral introduction. Therefore, by incorporating a very small amount of pyrethroid insect repellent in the coating film, the insect repellent effect is exhibited by directly contacting the insect. Since the coating film is heated to 200 to 300 ° C. when it is baked, it is necessary to use an insect repellent that does not reduce the insect repellent effect even when heated to this temperature. Therefore, in the present invention, a pyrethroid insect repellent whose weight loss upon heating at 300 ° C. is less than 50% by mass relative to the active ingredient was used. A pyrethroid insect repellent whose weight loss during heating at 300 ° C is 50% by mass or more based on the active ingredient, when dispersed in a coating film and dried, generate a pyrolytic component or carbonize under baking conditions. This tends to change the color tone of the coating film and adversely affect the physical properties. Further, since such an insect repellent has a relatively high vapor pressure, the insect repellent evaporates under the conditions of drying and baking of the coating film, and the repellent effect against living pests is small. Further, in order to exhibit the insect repellent effect, it is necessary to bring the pyrethroid insect repellent into direct contact with the insect. When various fillers such as pigments that form an interface with the coating resin are included in the coating (see a in FIG. 1), the pyrethroid insect repellent M causes an interface between the filler F and the coating resin P. That is, travel route R
Are formed and migrate to the surface of the coating film (see b in FIG. 1), and live pest repellent is effectively expressed for a long period of time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various metal plates such as ordinary steel plate, stainless steel plate, plated steel plate, aluminum plate, and copper plate are used as a base metal plate (painting original plate). The original coating plate is cleaned with alkali degreasing, pickling, etc. to clean the surface of the metal plate, and then phosphate treatment is applied to improve the wettability of the surface. Chromate treatment and chromium-free treatment are effective chemical conversion treatments for improving coating adhesion. Form a film. Specifically, it is formed by applying a chemical conversion treatment liquid to a metal plate by roll coating, flow coating, curtain coating, spray coating, dipping and lifting method, squeezing with a roller or the like, and then drying at 80 to 200 ° C. .

The chemical conversion treatment film is formed to have a thickness effective for preventing corrosion of the base metal plate and enhancing coating film adhesion.
For example, the chromate coating has a total chromium equivalent deposition amount of 5 to 100 mg / m ² , and the phosphate coating has a coating amount of 5 to 500 m.
g / m ² , Ti-Mo composite film 10-500 mg /
m ^2, at 0.1 to 500 mg / m ² or total metal coating weight in the fluorine coating weight is fluoro Al Cid based coating 0.1
A chemical conversion treatment film is formed so as to be about 500 mg / m ² . By forming this chemical conversion coating, the coating adhesion of the coating to the underlying metal plate is improved.

After the formation of the chemical conversion coating, a transparent or colored coating material is applied to the coated original plate, and the coating film is formed by drying and baking. As the paint for the undercoat film, epoxy type,
Base resins such as epoxy modified polyester type, polyester type, high molecular weight polyester type, polyether sulfone type, urethane type and urethane modified epoxy type can be used. The undercoating film can be transparent, but a paint colored in any color tone by using a coloring pigment is used.

When a rust-preventive pigment such as chromium-based strontium chromate, non-chromium-modified silica, or aluminum dihydrogen polyphosphate is added to the undercoating paint, a cut end surface of the coating original plate or a coating film defect generated during processing or construction This prevents the occurrence of defects such as blisters and rust originating from the part.
The rust preventive pigment to be added preferably has an average particle size in the range of 0.1 to 1 μm. If the average particle size is less than 0.1 μm, the rust preventive pigment is difficult to uniformly disperse when it is dispersed in the paint. On the contrary, when an anticorrosive pigment having an average particle size of more than 10 μm is added, the original properties of the coating film are impaired and the physical properties of the coating film are likely to be adversely affected. Moreover, the large particle size anti-corrosion pigment
Not only the smoothness of the coating film, but also the appearance of Yuzu skin, which significantly deteriorates the appearance of the coating film.

The rust preventive pigment is preferably blended in an amount of 5 to 150 parts by mass with respect to 100 parts by mass of the solid content of the undercoat paint. The effect of improving the corrosion resistance of the coating film by the rust preventive pigment becomes remarkable when the amount of the rust preventive pigment is 5 parts by mass or more, but is saturated at 150 parts by mass. Even if the anticorrosive pigment is added in an amount of more than 150 parts by mass, the workability and adhesion of the coating film will be deteriorated due to the excessive antirust pigment. The undercoat paint prepared to a predetermined composition is a metal such that the dry film thickness is 0.5 to 30 μm by a method such as roll coating, flow coating, curtain coating, or spraying which is usually used in the production of precoated metal sheets. Applied to the plate. The applied undercoat paint is baked according to a conventional method at an ultimate temperature of 200 to 300 ° C. for 30 to 120 seconds.

When a transparent undercoating film is formed, a dry coating film having a thickness of 0.5 μm or more exerts effects such as corrosion resistance and coating adhesion by forming the undercoating film. In the case of a colored paint, a dry film thickness of 3 μm or more is preferable in order to hide the underlying metal plate.
However, in any case, an undercoating coating film having a dry film thickness of more than 30 μm not only causes the coating film surface to have a citrus-like appearance and deteriorates the appearance of the coating film, but also causes cracking during baking. In this way, it is transparent or colored in any color tone, and an undercoating film having an anticorrosive effect is formed,
In some cases, the undercoat film may be omitted.

The live-insect-repelling paint is applied directly to the undercoating film or the chemical conversion-treated base metal plate, and the live-insect-repelling paint film is formed on the outermost layer by drying and baking.
The living insect pest repellent paint is not particularly limited in resin type. Polyester type, high molecular weight polyester type,
Fluorine-based, acrylic-based, urethane-based, epoxy-based, vinyl acetate-based, chloroprene-based and mixtures thereof, and modified resins containing pyrethroid insecticides whose weight loss when heated at 300 ° C is less than 50% by mass relative to the active ingredient. It is prepared by blending. When a pyrethroid insect repellent whose weight loss during heating at 300 ° C is 50% by mass or more relative to the active ingredient is used, as described above, a pyrolyzed component is generated or carbonized under actual paint drying and baking conditions. By doing so, the change in color tone and the physical properties are likely to be adversely affected. Further, the highly sublimable insect repellent evaporates under the condition that the paint is dried and baked, and the effect of repelling live insects is small.

The amount of the pyrethroid insect repellent compounded is 0.05 based on 100 parts by mass of the solid content of the live insect pest repellent paint.
It is preferable to select in the range of 5 parts by mass. 0.05
If the amount is less than the mass part, the life pest repellent property of the coating film is insufficient,
If it exceeds 5 parts by mass, the gloss and color change of the coating film surface or the elongation of the coating film is deteriorated, and the workability is likely to be deteriorated. In addition, there is no particular advantage in repelling insects in daily life, and the cost is economically high. The pyrethroid insect repellent may be added directly to the paint, but a suitable solvent such as acetone, cyclohexane,
If it is dissolved in xylene or the like in advance, it can be easily blended. As the filler that forms an interface with the resin in the coating film, color pigments such as titanium oxide, extender pigments such as calcium carbonate and barium sulfate, various organic resin beads, organic resin powders, inorganic aggregates, etc. are used. it can. The particle size and blending amount do not matter. Select and mix in a range that does not adversely affect the workability of the coating film.

The blended pyrethroid insect repellent is uniformly dissolved in the paint, and it is easy to integrate with the paint resin to form a uniform paint film. Therefore, the original properties of the coating film can be maintained, and good life pest repellent properties can be imparted without deteriorating the physical properties such as gloss, color change, and processability. In addition, it is sparingly soluble in water, and there is no reduction in the effect of repelling living pests such as elution and falling off by washing with water. Furthermore, even if the coating film deteriorates over time, the pyrethroid insect repellent is uniformly dispersed in the coating film, so that the effect can be maintained for a long period of time without impairing the effect of repelling live insects. Also in handling
Since pyrethroid insect repellents have low acute oral and dermal toxicity to humans, they are superior in safety to conventional insect repellents.

The living pest repellent paint prepared to have a predetermined composition has a dry film thickness of 3 to 30 μm by a method such as roll coating, flow coating, curtain flow, spraying or the like which is usually used for producing a precoated metal sheet. It is coated on a metal plate so that the ultimate temperature is 200-300 according to the usual method.
It is baked at 30 ° C for 120 seconds. If the dry film thickness is less than 3 μm, sufficient smoothness cannot be obtained, and the coating appearance tends to be poor. On the other hand, when the film thickness exceeds 30 μm, not only does the surface of the coating film become a citron skin and the coating appearance deteriorates, but also cracking easily occurs during baking.

[0017]

Examples Example 1: Hot dip galvanized steel sheet (sheet thickness 0.5
mm, the amount of adhesion on one side is 50 g / m ² )
After the steps of pickling, washing with water, surface conditioning, washing with water, and drying, the coating type chromate treatment was performed, and the product was dried at 100 ° C. without being washed with water (total chromium conversion adhesion amount 30 mg / m ² ). Undercoat paint is applied to the chromate-treated base plate so that the dry coating film thickness is 5 μm, and the ultimate temperature is 210 ° C × 45.
It was baked and dried under the condition of seconds. As the undercoat paint, an epoxy resin-based paint containing a chromium-based anticorrosive pigment was used.

As the living insect pest repellent paint according to the present invention, a polyester resin paint containing 30 parts by mass of 2 μm titanium oxide as a white pigment is used as a base paint,
Acrinathrin, a pyrethroid insect repellent [Product name:
ACR-50 manufactured by Daiwa Chemical Co., Ltd.] A coating material prepared so that the compounding amount is the ratio shown in Table 1 with respect to the coating solid content is coated so that the dry coating film thickness is 15 μm, and the ultimate temperature of 230 is reached. It was baked and dried under the condition of ° C x 50 seconds. It should be noted that the acrinathrin used in this example was heated from room temperature to 300
When thermal analysis was performed at a temperature rise rate of 10 ° C / min up to ° C,
The weight had been reduced by 23% when heated to 300 ° C.

As a comparative example, permethrin, which is a pyrethroid insect repellent, was used. A coating film was formed in exactly the same manner as in the above-mentioned example except for the insect repellent used. Thermal analysis of this pyrethroid-based permethrin by the same method as above showed that the weight loss at the time of heating to 300 ° C. was 55.
%Met.

[0020]

Test pieces were cut out from each of the obtained coated steel sheets and subjected to the following evaluation test. Cockroach repellent test with insect repellent test piece The test method was conducted according to the test method of Japan Environmental Sanitation Center. As shown in FIGS. 2 and 3, height 9c
A test sample 2 and an insect repellent component-free test plate 2 ′ cut into 7 × 7 cm are placed as a pair in a resin-made upper open container 1 having a size of m, a width of 26 cm, and a length of 20 cm. On the test sample plate 2 and the test plate 2'containing no insect repellent component, a veneer plate 3 of the same size as the sample plate was placed, and the height of the square was 5 m.
A square bar 4 having a width of 5 mm and a length of 50 mm is placed to form two shelters, and a water absorbent cotton 5 and a solid feed 6 are placed in the center of the container 1. To prevent escape of cockroaches, vaseline was thinly applied on the inner wall of the upper part of the container, and then 20 adult cockroaches were put in each cockroach, and an insect repellent shelter formed using the test sample plate 2 and an insect repellent component were not used. Select one of the unprotected insect shelters formed using the compounding test plate 2 ', select the desired shelter, and after a predetermined time, count the number of cockroaches living in any shelter, and calculate the repellent effect by the following formula. It was judged.

The test was repeated three times in consideration of variations due to the light source, temperature / humidity difference, individual difference, etc., and the repelling rate was calculated from the total value. At this time, when the number of cockroaches lurking in the treated shelter even once exceeded the number in the untreated shelter, the repellent effect was not recognized and the overall repellent rate was set to 0%. Repelling rate (%) = (1- (number of test insects in treated plot / number of test insects in untreated plot)) × 100

After the coated steel sheet was subjected to a 180 degree contact bending test in accordance with the processing test "JIS K5400 8.1 Bending resistance" test, the coating film at the bent portion was observed and no cracks were detected. The workability was evaluated as ○. Evaluation of coating film appearance Test No. Based on the color tone and gloss of 1 as a reference, it was visually observed under a fluorescent lamp to perform a sensory test. Test N
o. A sample having the same evaluation as 1 was evaluated as ◯. The results are summarized in Table 2.

[0024]

As can be seen from the survey results in Table 2, Test N in which a coating film containing acrinathrin as an insect repellent was formed.
o. The coated metal plates of Nos. 2 to 9 were able to exhibit cockroach repellency. Test No. 5 in which the amount of acrinathrin blended is 0.05 to 5 parts by mass with respect to 100 parts by mass of the solid content of the coating material In Nos. 3 to 8, the cockroach repellent property was maintained for a long period of time, and there was no problem in processability and coating appearance.
However, Test No. 1 containing a small amount of acrinathrin incorporated as an insect repellent. In No. 2, workability and coating appearance were good, but it was not sufficient in terms of maintaining cockroach repelling property for a long period of time. Furthermore, Test No. 1 containing a large amount of acrinathrin incorporated as an insect repellent. In No. 9, the cockroach repelling property was good, but there were some problems in terms of workability and coating appearance.

Further, as a pyrethroid insect repellent, 30
Test No. of Comparative Example using permethrin whose weight loss during heating at 0 ° C. exceeds 50% by mass relative to the active ingredient. 10 to
In 15, the cockroach repellent property was not sufficient. It is considered that the added permethrin is likely to evaporate or thermally decompose, and that the thermal decomposition product is concentrated on the outermost layer of the coating film, so that an effective insect repellent component does not exist on the outermost layer of the coating film. Further, if the amount of permethrin added is increased, the coating film becomes yellowish due to the effect of thermal decomposition products, and if the amount is further increased, the processability deteriorates.

Example 2 An undercoated steel sheet which had been subjected to the same treatment as that used in Example 1 had a polyester resin-based coating as a base coating and the same pyrethroid insect repellent as that used in Example 1 as a coating solid content. 0 to 100 parts by mass.
In addition to the compounding amount of 05 parts by mass, the coating material prepared by mixing and preparing the fillers shown in Table 3 with different compounding amounts was prepared in a dry film thickness of 15
The coating was applied to have a thickness of μm, and baked and dried under the condition that the ultimate temperature was 230 ° C. × 50 seconds. A test piece was cut out from each of the obtained coated steel sheets, and a cockroach repellent test and a processing test were performed in the same manner as in Example 1. The cockroach repellent test was carried out one day after the preparation. The results are shown in Table 3.

[0028]

As can be seen from the results of the investigation in Table 3, those containing a filler in the coating film surely improve the cockroach repellent property. And, the larger the amount of filler compounded, the better the cockroach repellent property. However, the results shown in Table 3 show that if the filler content is too large, the processability may deteriorate. Therefore, it may be necessary to select and adjust the optimum content according to the type and size of the filler. It represents.

[0030]

As described above, in a coated metal plate having a baked coating film, a pyrethroid insect repellent whose weight loss at the time of heating at 300 ° C. is less than 50% by mass relative to the active ingredient in the outermost layer. In a proportion of 0.05 to 5 parts by mass with respect to 100 parts by mass of the solid content of the paint,
By forming a coating film that also contains a filler to ensure the migration path of this insect repellent to the coating surface, the pyrethroid insect repellent is present in the coating without thermal decomposition or evaporation during baking. As a result, it is possible to obtain a coated metal sheet that exhibits excellent life-insect repellency over a long period of time without impairing the original physical properties of the coated metal sheet.

[Brief description of drawings]

FIG. 1 is a cross-sectional structure (a) of a coated metal plate and a diagram (b) illustrating a migration path of an insect repellent.

FIG. 2 Test sample and shelter morphology used for cockroach repellent test

[Fig.3] Layout of shelter used for cockroach repellent test

[Explanation of symbols]

S: Original plate P: Coating film M: Insect repellent F: Filler R: Transfer route 1: Container 2: Test sample plate 2 ': Sample plate not containing insect repellent components 3: Veneer plate 4: Square wood 5: Absorbent cotton with water 6: Solid feed

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) B05D 7/24 302 A01N 53/00 508B (72) Inventor Koji Mori 7-1 Takatani Shinmachi, Ichikawa City, Chiba Prefecture Nisshin Steel Co., Ltd. Technical Research Institute (72) Inventor Kenichi Okubo 7-1 Takaya Shinmachi, Ichikawa City, Chiba Nisshin Steel Co., Ltd. Technical Research Laboratory F Term (reference) 2B121 AA12 AA16 CA02 CA52 CA55 CC22 CC25 EA02 EA03 EA07 FA07 FA08 FA13 4D075 BB28Z BB93Z CA13 CA33 CA45 CA47 DA06 DB01 DC38 EA05 EB07 EC13 4H011 AC06 BA01 BB15 BC19 DA07 DA12 DD06 DH02 DH04 DH05

Claims (3)

[Claims] 1. A coated metal plate on which a baked coating film is formed, wherein the outermost layer of the coated metal plate contains a pyrethroid insect repellent whose weight loss upon heating at 300 ° C. is less than 50% by mass relative to the active ingredient. A coated metal plate with excellent repellent properties for daily life pests, which is characterized by being formed. 2. The pest repellent according to claim 1, wherein the outermost layer coating film contains 0.05 to 5 parts by mass of a pyrethroid insect repellent based on 100 parts by mass of the solid content of the paint. Excellent painted metal plate. 3. A coated metal sheet having excellent repellent properties for daily life pests according to claim 1, wherein the outermost coating film contains a filler.