JPH11280807A - Anti-rust spring material - Google Patents

Abstract

(57) [Summary] [Problem] To provide a rust-preventive spring material having excellent rust-preventing ability for automobiles, railway vehicles, ships, and the like used outdoors. SOLUTION: A zinc rich primer layer having a thickness of 20 to 40 μm, an epoxy resin paint layer containing an alkaline pigment having a thickness of 15 to 25 μm, and a thickness of 15 are provided on a spring base material.
An aqueous paint layer having a thickness of about 25 μm is sequentially laminated to form a rust-proof spring material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust-preventive spring material, and more particularly to a rust-preventive spring material for automobiles, railway vehicles, ships and the like used outdoors.

[0002]

2. Description of the Related Art Generally, spring materials are made of steel and have high strength, but are easily corroded systematically.
Once corrosion occurs, the risk of component breakage due to a decrease in fatigue strength increases, and this tendency is remarkable particularly in spring materials for automobiles, railway vehicles and ships used outdoors.

[0003] For this reason, spring materials are usually subjected to anticorrosion treatment such as painting, plating, blackening, and phosphate coating. Among them, in the anti-corrosion treatment by painting, zinc-rich or aluminum-rich paint having high anti-corrosion properties is used to withstand severe corrosion conditions.
In the case of a leaf spring composed of more than one sheet, it is impossible to prevent moisture from entering the narrow gap formed in the overlapped portion of the adjacent leaf from the outside, and corrosion occurs at this point, and as a result, , Resulting in breakage of the spring plate due to corrosion fatigue. In order to prevent such troubles, the above-mentioned paint film is coated with, for example, an alkyd resin paint or a wax-based petroleum rust inhibitor to form two layers (Japanese Patent Application Laid-Open No. H3-140639). No.).

[0004] However, such an alkyd resin-based topcoat contains an organic solvent, and thus has a drawback that the working environment is contaminated. In addition, for example, when the gap between the plates such as a tapered leaf spring is wide, the gap cannot be sealed with a wax-based petroleum-based rust inhibitor, and since the rust inhibitor does not harden, between the plates. There is a drawback that mud and pebbles that have entered stay there and adversely affect anticorrosion properties.

On the other hand, when an aqueous paint is used as the top coat in order to eliminate contamination of the working environment, the acid usually contained in the top coat aqueous paint is present at the interface between the undercoat layer and the top coat layer. Water and water cause a chemical reaction with the zinc powder in the undercoat paint, and as a result, there is a disadvantage that interlayer adhesion is reduced, delamination of the coating film occurs, and rust prevention ability is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention overcomes such drawbacks in the conventional coating of spring materials, has no delamination, has excellent rust-preventive performance, and reduces the contamination of the working environment during coating. The object of the present invention is to provide a rust-proof spring material that does not occur.

[0007]

Means for Solving the Problems As a result of intensive studies on the rust-preventive spring material, the present inventors have found that a zinc-rich primer layer, an epoxy resin coating layer containing an alkaline pigment, By successively laminating paint layers and providing an epoxy resin paint layer on the intermediate layer, the aqueous paint layer and the zinc rich primer layer do not come in direct contact with each other, while suppressing the chemical reaction of zinc powder with acid and water, The alkaline pigment in the epoxy resin paint controls the zinc primer surface to about pH 8 to 11, which is the stable pH range of zinc, thereby preventing the formation of products that cause delamination and using an aqueous paint. Therefore, it has been found that the contamination of the working environment is suppressed, and the above object can be achieved, and the present invention has been completed based on this finding.

That is, the present invention provides a zinc-rich primer layer having a thickness of 20 to 40 μm and a thickness of 15
The present invention provides a rust-preventive spring material characterized by sequentially laminating an epoxy resin paint layer containing an alkaline pigment having a thickness of about 25 μm and an aqueous paint layer having a thickness of 15 to 25 μm.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in further detail with reference to the accompanying drawings. FIG. 1 is an enlarged cross-sectional view of a surface portion of a spring according to the present invention. A zinc-rich primer layer 2, an epoxy-based resin paint layer 3, and a water-based paint layer 4 are sequentially laminated on a spring base material 1.

The spring base material in the present invention includes materials generally used for springs, such as spring steel, hard steel wire, piano wire, oil-tempered wire, stainless steel wire, brass wire, nickel silver wire, phosphor bronze wire, and barium copper. It can be arbitrarily selected from a coil spring material such as a wire, a corresponding compression spring material, and a lap spring material. The shape of these spring substrates may be any shape such as a coil spring, a torsion bar, a stabilizer, a leaf spring, a leaf spring, and a compression spring, and is not particularly limited.

Next, the zinc-rich primer layer provided first on these substrates is formed using a primer made of high-purity zinc dust and a synthetic resin varnish as in the case of the conventional rust-proof spring. . This zinc-rich primer is known as a paint having an electrochemical anticorrosion effect.In the present invention, however, an epoxy resin having excellent adhesion and flexibility as a synthetic resin is used as a coloring agent, It is particularly advantageous to use one having a content of 90% or more. In addition, a zinc dust primer having a zinc content of about 80% can be used.

In the present invention, as a zinc-rich primer, a normal vehicle and zinc or zinc alloy powder having an average particle diameter of about 2 to 10 μm are used in a weight ratio of 5:95 to 30:
It is preferable that the coloring agent be contained at a ratio of about 70, and as the vehicle, for example, an epoxy resin, a cyanoacrylate resin, or the like is used.

The zinc-rich primer layer is preferably formed by a method such as brushing or dipping (dipping / jabbing). The thickness of the coating film after drying and curing needs to be in the range of 20 to 40 μm. The coating conditions such as the drying and curing temperatures are appropriately selected depending on the type of the vehicle within a range conventionally used for zinc-rich coating. If the thickness of this coating is 2
If the thickness is less than 0 μm, the long-term anticorrosion effect is not sufficiently exhibited. Becomes

In the rust-preventive spring material of the present invention, an epoxy resin coating layer is provided as an intermediate coating layer on the zinc-rich primer layer provided on the spring substrate in this manner. As the epoxy resin paint, excellent adhesion between the zinc rich primer layer and the aqueous paint layer provided on the epoxy resin paint layer, and moisture, acid, salt, etc., which cause rusting. Those which can suppress permeation and do not react with zinc or zinc alloy powder in the zinc-rich primer layer are preferable. As such a material, a material mainly containing an epoxy resin paint used as a vehicle in a zinc-rich primer is preferable.

[0015] Such epoxy resin paints include:
For example, those containing an alkaline pigment having a pH of about 9.5 to 10.5 using a modified epoxy resin of a bisphenol A / bisphenol F copolymer type having a weight average molecular weight of about 10,000 to 50,000 as a vehicle are suitable. . By using a pigment containing such an alkaline pigment, it is possible to suppress the formation of a reaction product which causes a decrease in adhesion due to a reaction with a component in the zinc-rich primer layer of the undercoat layer. When using acidic pigments,
Reacts with zinc or zinc alloy powder in the zinc rich primer layer, causing delamination. Epoxy resin paint having such properties is, for example, “Epony 1 type DC”
It is commercially available as [Mitsui Metallic Paint Chemical Co., Ltd., trade name] and the like, and can be easily obtained.

The method of applying the epoxy resin paint is not particularly limited, and can be arbitrarily selected from brush coating, roller brush coating, spray coating, airless spray coating, and the like, which are used in ordinary coating. . The drying and curing treatment may be either normal temperature drying or forced drying, but it is advantageous to forcibly dry and cure at a temperature of about 80 to 120 ° C. for about 5 to 30 minutes in order to shorten the working time.

The thickness of the dried and cured coating film is 15 to 25 μm.
m. When the thickness is less than 15 μm, the effect as the intermediate coating layer is not sufficiently exhibited, and the object of the present invention cannot be achieved. When the thickness exceeds 25 μm, no improvement in the effect is recognized for the thickness, and the economy is rather reduced. Disadvantageous.

In the rust-preventive spring material of the present invention, an aqueous paint layer is provided as an overcoat layer on the epoxy resin paint layer provided on the zinc rich primer layer. There is no particular limitation on this water-based paint,
Any paint can be selected and used from paints conventionally used as the overcoat water-based paint.

The aqueous paint includes an emulsion paint in which a drying oil, a resin varnish, a lacquer, a synthetic resin and the like are dispersed in an aqueous medium by the action of an emulsifier, and a resin having two or more carboxylic acid groups in a molecule ( There is a water-soluble paint obtained by neutralizing a carboxylic acid group of a polycarboxylic acid resin) with ammonia, an organic amine, an alkali metal compound, or the like, making the polycarboxylic acid resin water-soluble, and dissolving it in an aqueous medium. And any of them can be used.

The method of applying the water-based paint is not particularly limited, and may be brush coating, roller brush coating, spray coating, or the like.
It can be arbitrarily selected from airless spray coating and the like. The drying and curing temperatures can be appropriately selected depending on the type of the vehicle. The thickness of this dried and cured coating film is 15
２５25 μm. If the thickness is less than 15 μm, the effect as an overcoat layer may not be sufficiently exhibited, and if it exceeds 25 μm, no improvement in the effect is recognized for the thickness, which is rather disadvantageous economically. As described above, by using the water-based paint as the top coat, it is possible to suppress the contamination of the working environment due to the organic solvent.
In this way, a rust-preventive spring material having excellent rust-preventing ability is obtained.

The type of spring to which the rust-preventive spring material of the present invention is applied is not particularly limited. For example, a lap spring, an auxiliary spring, a torsion bar, a thin plate spring, a compression coil spring, a tension coil spring, a torsion coil spring, Examples include a bamboo shoot spring, a flat spring, a conical coil spring, and a spiral spring. It is particularly advantageous to apply the rust-proof spring material of the present invention to a lap spring.

[0022]

The rust-preventive spring material of the present invention is provided on a spring base material.
A zinc-rich primer layer, an epoxy resin paint layer, and a water-based paint layer are sequentially laminated, and an epoxy resin paint layer is provided as an intermediate layer. Since the water-based paint layer and the zinc-rich primer layer do not come into direct contact with each other. In addition, zinc or zinc alloy powder does not cause a chemical reaction by acid or water, delamination is suppressed, and has excellent rust-preventing ability.
In addition, since the conventional top coating is an organic solvent-based coating, during spray coating, there was also a problem in terms of safety, such as accompanying the risk of worker health hazards and fire occurrence due to solvent scattering, but in the present invention. Since no organic solvent is used,
It is also advantageous in terms of safety and hygiene.

[0023]

Next, the present invention will be described in more detail with reference to examples. The rust prevention and corrosion fatigue resistance in each example were tested by the following methods.

(1) Rust prevention: A salt spray test was conducted for 600 hours in accordance with JIS Z5400, and evaluated according to the following criteria. ：: No rust was observed at all △: Rust was partially observed ×: Rust was observed over the entire surface (2) Corrosion fatigue resistance: 2,250 after 48 hours of salt water spray
The operation of applying 50,000 vibrations with a load of kg ± 1,350 kg was defined as one cycle, and the number of times to cause damage was measured and evaluated according to the following criteria. ○: 300,000 times or more △: 180,000 times or more ×: Less than 180,000 times

Embodiment 1 A large truck spring (1750) having the structure shown in FIG.
× 80 × 25 mm, 3 layers), first, a zinc rich paint primer [manufactured by Mitsui Kinzoku Paint Chemical Co., Ltd., trade name “Zinky 101S (revised)”] is applied by dip coating, dried and cured, An undercoat layer having a thickness of 40 μm was provided. Then, a paint using a polymer specially modified epoxy resin varnish as a vehicle [Mitsui Metal Paint Chemical Co., Ltd.]
Co., Ltd., trade name “Epony 1 type DC”] was applied by airless spray coating, dried and cured to form an intermediate coating layer having a thickness of 15 μm. Finally, an aqueous paint using a phthalic acid emulsion resin as a vehicle [SCHWAAB Co., Ltd., trade name “WASSER LACK”] is applied on the intermediate coating layer by airless spray coating, and dried and cured. Thus, an overcoat layer having a thickness of 20 μm was provided. Table 1 shows the rust prevention and corrosion fatigue resistance of the rustproof spring material thus obtained.

Example 2 A rustproof spring material having a zinc-rich primer layer of 35 μm, a middle coat layer of 20 μm and a top coat layer of 20 μm was produced in the same manner using the same paint as in Example 1. This was tested for rust resistance and corrosion fatigue resistance, and the results are shown in Table 1.

Example 3 A rustproof spring material having a zinc-rich primer layer of 30 μm, a middle coat layer of 25 μm, and a top coat layer of 20 μm was produced in the same manner as in Example 1 using the same paint. This was tested for rust resistance and corrosion fatigue resistance, and the results are shown in Table 1.

Comparative Example 1 A rustproof spring material was produced in the same manner as in Example 1 except that the intermediate coat layer and the overcoat layer were not provided. The rustproofing spring material obtained was tested for rustproofing and corrosion fatigue resistance, and the results are shown in Table 1.

Comparative Example 2 A rustproof spring material was manufactured in the same manner as in Example 1 except that the intermediate coating layer was not provided. The rustproofing spring material obtained was tested for rustproofing and corrosion fatigue resistance, and the results are shown in Table 1.

Comparative Example 3 An undercoat layer having a thickness of 25 μm was provided on the spring material using the same zinc rich paint primer as in Example 1, and a 20 μm thick overcoat was formed thereon using a commercially available black anticorrosive paint for springs. Layers were provided. The rustproof spring material thus obtained was tested for rustproofness and corrosion fatigue resistance.
Shown in

[0031]

[Table 1]

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a surface portion of a spring material of the present invention.

FIG. 2 is a reduced side view of the spring material used in the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spring base material 2 Zinc rich primer layer 3 Epoxy resin paint layer 4 Water-based paint layer

Continued on the front page (72) Inventor Toshikazu Ebata 1827-4 Kamitakano, Yachiyo-shi, Chiba Pref. Inside the Horikiri Co., Ltd. (72) Inventor Makoto Tomita 1827-4 Uetakano, Yachiyo-shi, Chiba Pref.

Claims (1)

[Claims] 1. A zinc-rich primer layer having a thickness of 20 to 40 μm, an epoxy resin coating layer containing an alkaline pigment having a thickness of 15 to 25 μm, and a thickness of 15
A rust-proof spring material characterized by sequentially laminating an aqueous paint layer having a thickness of about 25 μm.