JPS5964352A - Structure made of metal having excellent shock resistance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a painted metal structure, and more particularly, to a metal structure provided with a coating layer that has excellent impact resistance and, as a result, has excellent long-term corrosion resistance when used outdoors. It is related to.

Metal structures used outdoors, such as automobiles and buildings, are subject to impact (chimping) from sand, pebbles, etc., and the paint film is depleted, and rust begins and progresses in these areas, causing metal structures to deteriorate. has a significant impact on the lifespan of the

Particularly in the case of automobiles, the paint film is frequently damaged by impact from the eyes and dirt thrown up by other cars while the car is in motion. It is no exaggeration to say that the corrosion resistance of a portion subject to chipping depends on the chipping resistance of the coating film.

It is composed of a laminated film of paint film, and the total test thickness is 50 to 12
It is often set to 0 μmn. On the other hand, in buildings,
It often has a multi-layer structure, consisting of an undercoat (primer) that takes into account the adhesion of the paint film, and a top coat that takes into account appearance and surface properties.

-Also, in general, the hardness ζ of the paint film is, in the case of baking paint,
Increasing the baking temperature or prolonging the baking time will make the product more scratchy and more likely to cause scratches. However, the hardened coating may break when exposed to an impactful external force (so-called chipping), making it unsuitable. Therefore, in order to absorb the impact force, the lower layer must be made soft, making it weaker against the clutch. That is, the scratch resistance and chipping resistance of a coating film are contradictory properties, and it has been difficult to achieve both.

In addition, a method of incorporating flaky Merck or ultrafine fine mica particles into the intermediate coating film has been known, but such flakes and particles do not cause the complex entanglement of fibers in the coating film. Because of this, it has a weak role as a reinforcing material and has a weak impact absorption ability, so there is a problem that it cannot fully demonstrate its function.

The present inventors have learned from past experience that simply making the outermost coating film harder is not effective in improving chipping resistance, and rather focused research on the physical properties of the intermediate coating film. As a result, by using a composite material of resin and fibrous glass as the intermediate coating film directly below the outermost coating film of a metal structure, the coating resin was made flexible, and the glass fiber added as a reinforcing material was In addition to providing scratching force, we focused on improving the impact force absorption ability of composite materials, sought the optimal conditions, and succeeded in improving the scratch resistance and chimping resistance of the multilayer coating layer.

That is, the present invention includes a fibrous glass having a resin hardness of 3 H or less and a length of 1 to 100 μn in a weight range of 1 to 60 μm, directly under the outermost coating film. This is a metal structure with excellent impact resistance, characterized in that the thickness of the monolayer is 10 to 100 μn.

The present invention will be explained in detail below.

First, one of the important structural conditions of the present invention is that fibrous glass is particularly used as the reinforcing material. That is,
By including a large number of glass fibers, the coating film forms a more complex and diverse entanglement than that of the thin flakes or ultrafine particles described above, and this has a remarkable effect as a reinforcing phase. Compared to the mother, it is easier to make fibers and is easier to obtain. Further, as a matter of course, glass fiber is chemically stable and also has excellent heat resistance.

Next, the reason for limiting the distance of the present invention will be explained.

It is better that the hardness of the paint film just below the first coat is not too hard. When the lead gage hardness exceeds 3H, the chimping resistance decreases and the coating film may be damaged by impact. That is, by setting the hardness of the resin to 3H or less and maintaining scratch resistance by adding fibrous glass, both scratch resistance and chipping resistance can be satisfied.

Next, the size of the fibrous glass added to the paint film is related to painting workability, and if it exceeds 100 μm, it will not be uniformly dispersed in the paint. The state of existence also becomes uneven. However, the viscosity of the paint also increases, deteriorating painting workability. Considering that this (143-shaped glass is manufactured by grinding long fibers),
It is extremely unethical to make the length shorter than the diameter of the fiber.

Since the current glass fiber diameter is about 1 to 15 μm, it is realistic to set the minimum glass fiber length used in the present invention to 1 μm. For the reasons mentioned above, the glass base contained in the coating film of the metal structure of the present invention;
The length of 1 to 1, except for unavoidable exceptions.
00 μm.

Next is the addition of fibrous glass.
Addition of 0.5% by weight in a coating film has no effect on surface scratch resistance and chipping resistance, but a single addition in a coating film has a significant effect.

1. If it exceeds 60% by weight in the coating film, scratch resistance will improve, but chipping resistance will decrease. Therefore, considering the performance of both, the most preferable is 5 to 30 weight 1 ton.
%.

Next, the thickness of one layer of coating composited in this way is 10μm
Less than ll'U [No effect on chimping property, 1,
On the contrary, it decreases when it exceeds 100 μm. 50 .mu.m] or more, it is difficult to screw it in one time, and it is necessary to do it in two or three times. Therefore, in consideration of scratch resistance, chimping resistance, and workability, the most preferable range is 10 to 50.
It is μm.

In addition, when carrying out the present invention, it is easy to carry out the invention by uniformly dispersing the fibrous glass in the paint while thoroughly stirring it, and applying it to the entire building structure by brushing over the streaks. Furthermore, the conventional coating method is not changed at all.

The effects of the present invention will be explained in more detail below using Examples.

Example 1 A cold-rolled steel sheet was subjected to chemical conversion treatment and electrodeposition coating (film thickness 20 μm), and further electrostatic coating was applied as an intermediate coat to a thickness of 30 μm. 1 to 150 μl of fibrous glass is applied over 1 to 100 μl of intermediate coat so that 0.5 to 80 μl of fibrous glass is impregnated in each intermediate coat.
So that 15 μm long fibrous glass is included,
It was uniformly dispersed in the paint in advance. The lead hardness of the resin part of the intermediate coating film was adjusted by baking temperature and baking time so that it was 2H14H.

Furthermore, after forming a coating film of 4 () μm as a top coat by electrostatic coating, scratch resistance and chipping resistance were evaluated. For comparison, samples similar to those for glass fibers were prepared and evaluated, with 5 to 30 meshes of flaky glass containing 150 meshes or less.

The results are shown in Table 1. As a result, it was found that fibrous glass in the coating film is effective when 1 to 60n<m%, especially 5
The scratch resistance and chipping resistance are both extremely good with ~30-layer stacking, the paint workability is poor when the fibrous glass exceeds 100 μm, and the pencil hardness of the resin is 4.
It can be seen that when the temperature becomes H, the chipping resistance decreases. 1
However, it can be seen that for the same glass addition and the same resin hardness, the addition of fibrous glass has better chipping resistance than the addition of flaky glass.

Example 2 A sample of the same three-layer coating as in Example 1 was prepared, and the middle layer was 15 times thicker and the pencil hardness of the resin was 2.
H, and the film thickness was varied from 5 to 120 μm1. Table 2 shows the evaluation results of scratch resistance, chipping resistance, and rowability.

As a result, the film thickness range of the intermediate coating film with good scratch resistance, chipping resistance, and workability was IO to 1.0. O
OμIn'''C reed, the best range is 10-50μm
It can be seen that it is.

② The paint film was marked with a drawing, and the occurrence of rust from the uneven parts was evaluated after 6 cycles of OCT testing.

■ No rust at all, ○ Slight rust △ or ＼ Rust × Rust (Note) 00 T test 1 cycle 2 Salt water spray 24 hrT
fFVr ”℃, 6hr H+ 70℃, 6hr,
? hr salt water fountain g24hr-→-40℃, 6br-++70℃3
hr 6br6hr-1→
Room temperature br 100 pieces of 2.1/4 inch nuts were dropped naturally onto a painted steel plate from a height of 2 m, and the ooT test was conducted for 6 cycles in the same manner as in *l to determine the rust occurrence on the damaged parts of the paint film. evaluation.

■ No rust ○ Slight rust Δ ＼ Rust x Rust 0 3, glass dispersion state, ease of controlling film thickness, etc. compared to the case without glass addition.

G) is the same Δ or ＼ Inferior Metal structure with excellent impact resistance 3, connection with famous case for amendment 1 series Applicant fl: i'IJi (Residence) 2-6 Otemachi, Chiyoda-ku, Tokyo? J3 Name (Name) (665) Nippon Steel Corporation 4, Agent Residence Tokyo Tech; Taiyo Building ``II'' II, No. 12-1 Nipponkabu-cho, Chuo-ku, Tae-gun (Kn < 7) 1 Showa era
Year, month, day (shipping) 5 ° "1・Zetsu" Ko I11
・Yama II: (1・“... 8, 1lti, '+F contents different) Contents of correction according to me Specification 3.2 Negative first line ``...yc, the paint film is very noticeable.''
2 [Correction: [The paint film was noticeably damaged by...].

Claims (1)

[Claims] (1) Directly below the outermost coating layer, fibrous glass with a resin pencil hardness of 3H or less and a length of 1 to 100 μm is included in the range of 1 to 60 times, and the thickness of the coating layer is 10~100μm
A metal structure with excellent impact resistance.