JPH06109180A - Corrosion preventive hose clip - Google Patents

Abstract

PURPOSE:To provide a hose clip which is excellent in corrosion preventing performance and especially suitable for assembly in corrosive environment. CONSTITUTION:Metal powder-chromic acid chemical conversion treatment is executed on the surface of a steel hose clip base material to form the first film. The second film is formed of water system treatment liquid containing water system resin and silica material on the first film. Even when the hose clip is enlarged in diameter in the case of attaching it to a rubber hose 3, the second film formed of the water system resin also extends to make the hose clip keep the corrosion preventing ability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anticorrosion hose clip having a high anticorrosion effect, which is obtained by applying anticorrosion treatment to the surface of a metal hose clip base material.

[0002]

2. Description of the Related Art Generally, metal (mainly steel) members are widely coated with zinc such as electrogalvanized for rust prevention, and are also used for hose clips for tightening the outer circumference of rubber hoses. In order to prevent rust, a lot of electrogalvanizing treatment has been conventionally performed. However, in recent years, the corrosive environment has deteriorated due to salt damage, etc., and higher rust prevention power is required for metal parts, and pollution problems in the treatment process,
In addition, the problem of breakage due to hydrogen embrittlement of hose clips treated by electroplating has been highlighted. For this reason, surface treatments other than electroplating have been adopted.

One of the prominent ones is metal powder-chromium oxidization treatment (dacrotizing, dacrotized treatment ("Dacrotized" is a registered trademark for its treated product)).
A method of coating and baking a metal base with a coating composition called chromic acid, metal powder (mainly zinc, aluminum) and a chromic acid reducing agent (US Pat. No. 338).
2081, Japanese Patent Publication No. 52-904, Japanese Patent Publication No. 52-19
01 and others, practical surface technology (published by Japan Metal Surface Technology Association) '
85 VOL. 32 / NO. 6 pp. 272-279)
Is.

This metal powder-chromium oxidization treatment has an excellent effect as a rust preventive coating against salt water as compared with galvanizing treatment, and has no fear of hydrogen embrittlement and little pollution problems. It can be said that the process is suitable for clips. However, the hose clip cannot avoid contact with the hose due to its function, and the metal powder-chromium oxidization treatment film has sufficient performance compared with the case where the member is used alone due to the electrolytic corrosion effect with the black rubber hose. Can not be demonstrated.

In order to further improve the rust preventive performance of the metal powder-chromium oxidization treatment film, the metal powder-chromium oxidization treatment film is used as a first film, and 1 to 2 are formed on the first film.
The invention of forming a film containing silicic acid as a main component which does not contain a resin having a size of μm or more as the second film is Japanese Patent Publication No. 60-44145.
It is disclosed in the publication. In this invention, the pores existing in the first coating are filled and the adhesion to the metal base and the bonding force between the first coatings are improved.

[0006]

However, even if the above-mentioned conventional invention is applied to a hose clip, there is a problem that its rustproofing performance is still insufficient. The reason for this is that in the above invention, since the second coating does not contain a resin, the second coating containing silicic acid as the main component lacks in stretchability, and once the hose clip is attached to the hose, it is elastically expanded in diameter. It is considered that the second coating cannot be stretched due to the elastic elongation of the hose clip base material and the second coating may be cracked. Therefore, it is considered that when rainwater or the like splashes on the member, water penetrates from the cracked portion to promote corrosion and cause red rust in a short time.

[0007]

In order to solve such a technical problem, the inventor has found that a hose clip which is a film formed of a water-based treating agent and which is excellent in rust preventive performance even when used by being attached to a hose. As a result of researches to achieve the above, the present invention was completed.

According to the present invention, a rust preventive hose clip which does not cause red rust for a long period of time and is excellent in rust preventive can be obtained, and the working environment is hardly harmed by using the aqueous treatment liquid in the manufacturing process. . In addition, a wax-added hose clip can be excellent in assembling the rubber hose due to the lubricity of the wax.

For example, a hose clip 1 for a radiator of a passenger car shown in FIG. 1 has a plate thickness of 1.
A steel material having a diameter of 6 mm and a plate width of 18 mm was used and formed into an annular shape having a diameter of 37 mm. Then, an elastic rubber hose 3 is inserted and connected to the outer circumference of the tip of the tube 2,
The outer circumference of the rubber hose 3 at this portion is surrounded and fixed by an annular hose clip 1 to prevent the hose from coming off. Therefore, the hose clip 1 is accelerated in corrosion by coming into contact with the rubber hose containing sulfur or carbon.

Here, as shown by the solid line in FIG. 1, the hose clip 1 is elastically expanded in diameter when it is assembled to a rubber hose, and the inner surface thereof is elastically expanded. For this reason, the stretchability is also required for the coating layer when it is assembled to the hose, otherwise the coating layer will be cracked.

The molded hose clip base material is subjected to pretreatments such as degreasing and surface adjustment if necessary,
In order to form the metal powder-chromium oxidization treatment coating of the first coating, treatment is performed by a predetermined method.

The coating method is usually a tank basket method (dip spin) in which a hose clip is put in a basket and immersed in a treatment solution prepared by a predetermined procedure in a tank, and then pulled up to remove excess treatment solution by centrifuging. Method is more efficient, but a hanger method (dip drain method) of hanging on the overhead conveyor and immersing in a bath for coating may be adopted, and other coating methods such as spray painting are not available. Can be implemented without After this coating process, a baking process is performed under predetermined conditions. Then, the amount of the first coating film obtained by repeating the above treatment once or more is 15 mg / dm.
When it is 2 or less, the performance cannot be sufficiently exhibited, and too much is not economically preferable. Usually 30-900mg / dm2
The degree is preferably, and more preferably 100 to 500 mg /
It is dm2. Further, at this time, it is preferable that the first film is formed uniformly on the hose clip base material as much as possible.
The second treatment liquid that forms the second film is a water-based resin-silica material or a water-based mixed solution containing a water-based resin-silica material-wax.

As the water-based resin, an acrylic resin, an alkyd resin, an epoxy resin, a polyester resin, a silicone resin or the like can be used as long as it is a water-soluble type, a dispersion type, an emulsion type or the like, which is stable even when diluted with water. Is.

As the silica material, silicates, colloidal silica, silica powder and the like can be used, but it is necessary that they are compatible with the resin. When the amount of silica material is 100 or less relative to the resin solid content of SiO2, the effect of improving the corrosion resistance is not sufficient, while when it is 200 or more, the adhesion performance is deteriorated, which is not preferable. Is preferred, and more preferably 3 to 1
00.

As the wax, those which can be dispersed in water such as powder type and water dispersion type and water-soluble type can be used, and polyethylene wax is preferably used. The amount of wax added is as follows: resin solids and SiO2
When the total amount is 100 or less, the effect of lubricity does not appear at 0.05 or less. Further, even if added in an amount of 200 or more, improvement in lubricity cannot be expected, and therefore, addition of 0.1 to 100 is usually preferable.

In addition, it is possible to add additives such as a dispersant, a wetting agent, and a thickener, if necessary, and it is also possible to use pigments such as an extender pigment, a coloring pigment, and a rust preventive pigment. .

A tank basket system (dip spin system) is adopted as a coating method, but a hanger system (dip drain system) may be adopted, and other coating methods such as curtain coating and spray coating may be used. . A baking treatment is performed to form the second film, but if the temperature is 60 ° C. or lower, a long drying time is required, which is not preferable in terms of productivity. On the other hand, it is not preferable to be higher than the temperature at which carbonization of organic substances such as resin and wax proceeds. Usually, the temperature is preferably 60 to 250 ° C, more preferably 120 to 200 ° C. Then, a baking process is performed for about 5 to 60 minutes.

If the amount of the second coating deposited, which is obtained by repeating the above treatment one or more times, is 10 mg / dm2 or less, the performance cannot be sufficiently exhibited, and if it is too large, it is not economically preferable. Usually, it is preferably about 10 to 1000 mg / dm2, more preferably 30 to 300 mg / dm2. Further, at this time, it is preferable that the second coating is formed as uniformly as possible on the hose clip base material.

[0019]

EXAMPLES Examples of the present invention will be described below together with comparative examples. (Preparation of test sample) Steel material with a plate thickness of 1.6 mm and a plate width of 18 mm is used as a hose clip base material, and a diameter of 37 m
The hose clip base material, which was molded into an annular shape of m and was heat-treated, was subjected to shot blasting as a pretreatment to form a first coating in the following manner to obtain a first coating-treated sample.

Prepare a mixture of chromic anhydride and calcium oxide in deionized water in amounts such that chromic anhydride is 6.9% and calcium oxide is 1.2% (this is referred to as the first composition). Metal zinc flakes (thickness 0.1-
0.3 μm, average length of the longest part is about 1.5 μm) 60%
Is dispersed in propylene glycol mixed with 0.2% of a surfactant (alkylphenol polyethoxy addition compound type surfactant) to make the total amount 100% (this is the second composition).

The first and second compositions were mixed at a weight ratio of 58:42 by pouring the former into the latter with slow stirring and stirred overnight at room temperature. The obtained mixed solution was dip-coated on a pre-treated hose clip by a tank basket method, and after the dipping, centrifugal separation was performed to attach a predetermined processing solution. After that, the hose clip was heated so that the surface temperature of the hose clip reached 300 ° C. in the electrically heated hot air circulation furnace for 10 minutes, and then allowed to cool indoors. This process was repeated twice. The amount of adhesion is 160 mg / dm on average
2 (average thickness of about 5 μm).

The material subjected to the above-mentioned treatment is used as a test material having undergone the first film treatment, and the prepared treatment liquid for forming the second film is dip-coated by a tank basket system,
After the immersion, the solution was centrifugally shaken off to deposit a predetermined treatment liquid. After that, heat treatment was performed in an electrically heated hot air circulation furnace under treatment conditions suitable for each treatment liquid, and this was used as a test sample of an example or a comparative example. When preparing the treatment liquid for forming the second film, a dispersant, a wetting agent or a thickening agent was added, if necessary, in addition to the following description. If necessary, dispersion was performed using a paint disperser or the like.

(Comparative Example 01) A test sample was prepared using only the first film without forming the second film.

(Comparative Example 02) Sodium silicate (JIS1
No.) 50% and deionized water 50%, the second coating was formed with the treatment liquid, and it was used as a test sample. The baking condition was 170 ° C. for 20 minutes, and the adhesion amount was about 40 mg / dm 2.

(Comparative Example 03) Acrylic emulsion resin-A (solid content 50%, pH 9.5) 40% and deionized water 60% were added to the treatment liquid to form a second coating film, and a test sample was prepared. And Baking conditions are 150 ℃ -20
The amount and the adhered amount were about 60 mg / dm 2.

(Comparative Example 04) Water-soluble alkyd resin-B
(Solid content 70%, pH 8 to 9) A second film was formed with a treatment liquid mixed in a ratio of 30% and deionized water 70% to obtain a test sample. The baking conditions are 140 ° C-20 minutes,
The adhered amount was about 60 mg / dm 2.

(Comparative Example 05) Aqueous acrylic resin-C (solid content 41.5%, pH 8.3 to 9.0) 50%,
A second coating was formed with a treatment liquid mixed with deionized water at a ratio of 50%, and used as a test sample. Baking conditions are 160 ° C-
After 20 minutes, the amount deposited was about 60 mg / dm 2.

(Comparative Example 06) A second coating was formed with a treatment liquid in which 35% of water-based epoxy resin-D (solid content 60%) and 65% of deionized water were mixed to prepare a test sample. The baking condition is 180 ° C for 20 minutes, and the adhesion amount is about 60 mg.
It was / dm2.

(Comparative Example 07) Water-dispersed polyethylene wax-E (solid content 40%, pH 9, particle size 3 μm)
m, density 0.97, softening point 128 ° C.) 50% and deionized water 50% to form a second coating film as a test sample. Baking conditions are 150 ℃ -20
The amount and the adhered amount were about 60 mg / dm 2.

(Comparative Example 08) Acrylic resin emulsion-A 30%, water-dispersed polyethylene wax-F (solid content 40%, pH 9, particle size 6 μm, density 0.
92, softening point 113 ° C) 10%, deionized water 60%
A second coating was formed with the treatment liquid mixed in the ratio of 1 to prepare a test sample. The baking condition is 150 ° C for 20 minutes, and the adhesion amount is about 5
It was 0 mg / dm2.

(Comparative Example 09) Water-based epoxy resin-D 2
0%, water-dispersed polyethylene wax-E 25%,
A second coating was formed with a treatment liquid mixed with deionized water at a ratio of 55% to obtain a test sample. Baking conditions are 160 ° C-2
At 0 minutes, the amount deposited was about 50 mg / dm 2.

(Example 01) Water-soluble alkyd resin-B
20%, colloidal silica-G (SiO2 20-2
1%, NaO2 0.35%>, pH 9.5-10, particle size 10-20mμ) 30%, deionized water 50% as a treatment liquid, a second coating film was formed to obtain a test sample. The baking condition is 140 ° C for 20 minutes, and the adhesion amount is about 50m.
It was g / dm2.

(Example 02) Acrylic resin emulsion-A 30%, sodium silicate (JIS No. 1) -H
A second coating was formed with a treatment liquid mixed at a ratio of 2% and deionized water of 68% to obtain a test sample. Baking conditions are 170 ℃
After 20 minutes, the amount deposited was about 50 mg / dm 2.

(Example 03) Aqueous acrylic resin-C 1
5%, amine silicate (SiO2 25.0% PH1
1.0) -I 20%, water-dispersed polyethylene wax-F 15%, deionized water 50% were mixed to form a second coating film, which was used as a test sample. The baking condition was 160 ° C. for 20 minutes, and the adhesion amount was about 60 mg / dm 2.

(Example 04) Water-based epoxy resin-D 2
5%, silica powder (SiO2> 99.9%, specific surface area 300 ± 30 m2 / g, primary particle size about 7 nm) -J
A second coating was formed with the treatment liquid mixed at a ratio of 5% and deionized water 70% to obtain a test sample. Baking conditions are 180 ℃
After 20 minutes, the amount deposited was about 60 mg / dm 2.

(Example 05) Water-soluble alkyd resin-B
20%, colloidal silica-K (SiO2 20-2
1%, NaO2 0.04%>, pH 9-10, particle size 10-20mμ) 10%, fine polyethylene wax-
K (particle diameter 30 μm, density 0.95, softening point 11
7 ° C) 1%, extender pigment (talc) 5%, coloring pigment (phthalocyanine blue dispersion (solid content 41%)
A second coating was formed with a treatment liquid mixed in a ratio of 2% and deionized water of 62% to obtain a test sample. Baking conditions are 160 ℃
After 20 minutes, the amount deposited was about 100 mg / dm 2.

Example 06 Aqueous acrylic resin-C 4
0%, colloidal silica-G 20%, rust preventive pigment (zinc phosphate) 1%, coloring pigment (carbon black dispersion (solid content 29%) 2%, deionized water 37%). A second coating was formed on the sample to prepare a test sample under the conditions of baking at 160 ° C. for 20 minutes and an adhesion amount of about 90 mg.
It was / dm2.

(Example 07) By the same processing as in Example 06,
The adhered amount was about 40 mg / dm 2.

Comparative Examples 01 to 0 having this second coating formed
9, about each hose clip of Examples 01-07, 3
The pieces were attached to a rubber hose with a resin rod inserted, and a corrosion resistance test was performed. The rubber hose used here is one that has been known to have a high degree of corrosion.

The corrosion resistance test is performed by a salt spray test (JIS-Z
-2371 neutral salt spray test method). In addition, the evaluation of the test results is performed after 120 hours and 240 hours after the start of the test.
It went after a lapse of time. As for the evaluation method, the degree of corrosion of the test sample was visually observed and evaluated by the following criteria.

◯: Red rust was not generated at all Δ: Spot rust spreads and a little rust juice started to flow ×: Rust juice flow was remarkable

[0042]

[Table 1]

[Brief description of drawings]

FIG. 1 is a front view showing a state where a hose clip is assembled.

[Explanation of symbols]

 1 ... Hose clip, 2 ... Tube, 3 ... Rubber hose

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaru Nomoto, Inoui, Aichi-gun Togo-machi, Aichi-gun, Haruki-ji, No. 1 Togo Works Co., Ltd. Address Togo Manufacturing Co., Ltd. (72) Inventor Takao Higashiyama 49-5 Shimokochi, Shimokurata-cho, Totsuka-ku, Yokohama-shi

Claims (2)

[Claims] 1. A second coating formed by subjecting a metal hose clip base material surface to a metal powder-chromium oxidation treatment as a first coating, and further forming a water-based treatment liquid containing a water-based resin and a silica material thereon. , Anti-corrosion hose clip covered. 2. A second coating formed by subjecting a metal hose clip base material surface to a metal powder-chromium oxidization treatment as a first coating, and further comprising an aqueous treatment liquid containing an aqueous resin, a silica material and a wax thereon. Anticorrosion hose clip covered with a film.