JP2668333B2 - Underlayer for coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a base layer for coating,
In particular, the present invention relates to an underlayer formed on a member surface and subjected to a coating process such as plating and painting.

[0002]

2. Description of the Related Art Conventionally, for example, when a coating layer is formed by coating the surface of a member, the surface of the member is sandblasted to increase the contact area of the member in order to improve the adhesion strength of the coating layer. Such means are used.

[0003]

However, the prior art is based on mechanical means such as sand injection, so that the degree of expansion of the contact area on the surface is relatively low, and therefore the adhesion strength of the coating layer is greatly improved. It is difficult to make it happen.

[0004] In view of the above, it is an object of the present invention to provide an undercoating layer having an extremely large contact area and capable of greatly improving the adhesion strength of a coating layer.

[0005]

The present invention SUMMARY OF] is a coating underlying layer formed member surface is composed of an aggregate of inorganic crystal having a body mind elevational Ho構 granulation, in its assembly, A large number of pyramidal inorganic crystals, which are at least one of a pyramidal inorganic crystal and a truncated pyramidal inorganic crystal, are included to form an underlayer surface to be subjected to a coating treatment, and the pyramidal inorganic material on the underlayer surface is included. Area A of crystal
₁ is characterized by A ₁ ≧ 40%.

[0006]

Since an infinite number of minute valleys are formed on the surface of the underlayer by the adjacent bipyramidal inorganic crystals, the contact area on the surface of the underlayer is dramatically expanded by these valleys.

By using such an underlayer, the adhesion strength of the coating layer can be greatly improved.

However, when the area ratio A ₁ of the pyramidal inorganic crystals is A ₁ <40%, the contact area expansion effect is low, and the adhesion strength of the coating layer is reduced accordingly.

[0009]

EXAMPLE In FIG. 1, a base layer 2 is formed on a surface of a steel plate 1 as a member by plating, and a coating layer 3 is formed on the surface of the base layer 2.

The underlayer 2 is composed of an inorganic crystal having a body- centered cubic structure (bcc structure ) , for example, an aggregate of metal crystals. The aggregate includes a large number of columnar metal crystals 4,
The tips thereof are composed of pyramidal metal crystals 5 which are at least one of pyramidal metal crystals and truncated pyramidal metal crystals so as to form the surface of the underlayer 2 to be coated.

The area ratio A ₁ of the pyramidal metal crystal 5 on the surface of the underlayer 2 is set to A ₁ ≧ 40%. Therefore, the aggregate may contain many granular metal crystals,
The aggregate may be composed only of the columnar metal crystals 4.

According to this structure, innumerable fine valleys 6 are formed on the surface of the underlayer 2 by the adjacent bipyramidal metal crystals 5, so that the underlayer 2 is formed by these valleys 6.
The contact area on the surface is greatly expanded, and thereby the adhesion strength of the coating layer 3 can be improved. However, when the area ratio A _{1 of} the pyramidal metal crystal 4 is A ₁ <40%, the effect of expanding the contact area is reduced.

As shown in FIG. 2, the pyramidal metal crystal 5 having the bcc structure contains at least one of the triangular pyramidal metal crystal 5 _{1 and the} hexagonal pyramidal metal crystal 5 ₂ .

As shown in FIG. 3, the columnar metal crystal 4, and therefore the triangular pyramidal metal crystal 5 ₁ and the hexagonal pyramidal metal crystal 5 ₂ have their (hhh) planes directed toward the surface side of the underlayer 2 at the Miller index ( hhh) Oriented metal crystals.

In this (hh) oriented metal crystal,
As shown in FIG. 4 (a), the triangular pyramid on each inclined surface of the metal crystals 5 ₁ at Miller index (hh0) plane is present, and FIG. 4
As shown in ( b), (hhh) planes and (5hhh) planes are alternately present in each slope of the hexagonal pyramidal metal crystal 5 ₂ in terms of Miller indices. In this case, in particular, the (hhh) plane has good wettability to a fluid coating material such as paint.
This is effective in improving the adhesion strength of the coating layer 3.

[0016] Therefore, the area ratio A ₂ of the hexagonal pyramid-shaped metal crystals 5 ₂ in the base layer 2 surface is set to A ₂ ≧ 30%. In this case, if A ₂ <30%, the effect of improving the wettability by the (hhh) plane is insufficient. Underlayer 2 surface may be formed only of hexagonal pyramid-shaped metal crystals 5 _2.

As shown in FIG. 5, the inclination of the (hhh) plane with respect to the virtual plane 7 along the surface of the underlayer 2 is the columnar metal crystal 4,
Hence appears as inclination, such as a triangular pyramid-shaped metal crystals 5 ₁ affects the adhesion strength between the base layer 2 and the coating layer 3. Therefore, the inclination angle θ formed by the (hhh) plane with respect to the virtual plane 7 is set to 0 ° ≦ θ ≦ 15 °. In this case, the inclination direction of the (hhh) plane is not limited.
When the inclination angle θ is larger than 15 °, the adhesion strength decreases.

As a metal crystal having a bcc structure, F
e, Cr, Mo, W, Ta, Zr, Nb, Ru can be exemplified a crystal of a single or an alloy of V, and the like.

In the plating treatment for forming the underlayer 2 made of an aggregate of metal crystals having a bcc structure, the basic conditions for performing the electric Fe plating treatment using the DC method are shown in Tables 1 and 2. Is.

[0020]

[Table 1]

Urea, saccharin and the like are used as organic additives.

[0022]

[Table 2]

As the energizing method, a pulse current method is applied in addition to the direct current method. In the pulse current method, as shown in FIG. 6 , the energization time T _ON from the start of the current rise to the start of the fall is 0.1 msec ≦ T _ON ≦ 6 msec, from the start of the previous rise to the start of the next rise. Is one cycle, and the cycle time is T _c , the time ratio T _ON / T _c is T T
_ON / T _c ≦ 0.45. The maximum cathode current density CDmax is set to CDmax ≧ 4 A / dm ² , and the average cathode current density CDm is set to CDm ≧ 2 A / dm ² .

In the electric Fe plating process, the deposition conditions and the form of the (hhh) -oriented Fe crystals are controlled by changing the processing conditions.

As the plating treatment, in addition to the electroplating treatment, for example, a vapor phase plating method such as PVD method, CVD method, sputtering method, ion plating and the like can be mentioned. Conditions for performing W and Mo plating by the sputtering method include, for example, an Ar pressure of 0.2 to 1 Pa and an Ar accelerating power.
DC 1 to 1.5 kW, base material temperature 150 to 300 ° C. Conditions for performing W plating by the CVD method include, for example, raw material WF ₆ , WF ₆ gas flow rate 2 to 15 cc / min.
, Chamber pressure 50-300 Pa, base material temperature 4
00-600 Ru ℃ der.

Hereinafter, a specific example will be described.

An underlayer 2 composed of an aggregate of Fe crystals was formed on the surface of the cold-rolled steel sheet 1 by subjecting the surface of the cold-rolled steel sheet 1 to electric Fe plating using a direct current method or a pulse current method.

Tables 3 and 4 show the electro-Fe plating conditions in Examples 1 to 16 of the underlayer 2.

[0029]

[Table 3]

[0030]

[Table 4]

Tables 5 and 6 show the area ratio of each Fe crystal on the surface of the underlayer 2, the average grain size of the Fe crystal, the abundance S of each oriented Fe crystal, and the evaluation of adhesion strength in Examples 1 to 16 of the underlayer 2. Each point is shown.

[0032]

[Table 5]

[0033]

[Table 6]

The area ratio of each crystal is given by (b / b) where a is the area of an arbitrary surface of the underlayer 2 and b is the sum of the bottom areas of the tri- and hexagonal pyramid-shaped Fe crystals existing on the arbitrary surface.
a) × 100 (%). The average particle diameter of the triangular pyramidal Fe crystal is the distance from each corner to each opposite side through the apex, that is, the average value of three distances, and the average particle diameter of the hexagonal pyramidal Fe crystal is the apex. Is the distance between the corners opposed to each other, that is, the average value of the three distances. Therefore, in the columns of the average grain size of Fe crystals in Tables 5 and 6 ,
The average grain sizes of various examples in which tri- and hexagonal pyramidal Fe crystals are mixed are shown by a value obtained by further averaging the average grain sizes of the crystals.

The abundance S is the X-ray diffraction pattern (X
The line irradiation direction is a direction perpendicular to the surface of the underlayer 2) and is determined by the following method. Describing Example 14 as an example, FIG. 7 is an X-ray diffraction diagram of Example 14, and the abundance S of each oriented Fe crystal was obtained from the following equation. Note that, for example, a {110} oriented Fe crystal is an oriented Fe crystal with the {110} plane facing the underlayer 2 surface side.
Means crystal. {110} oriented Fe crystal: S ₁₁₀ = {(I ₁₁₀ / IA ₁₁₀ ) / T} × 100, {200} oriented Fe crystal: S ₂₀₀ = {(I ₂₀₀ / IA ₂₀₀ ) / T} × 100, {211} oriented Fe crystal: S ₂₁₁ = {(I ₂₁₁ / IA ₂₁₁ ) / T} × 100, {310} oriented Fe crystal: S ₃₁₀ = {(I ₃₁₀ / IA ₃₁₀ ) / T} × 100, {222} oriented Fe crystal: S ₂₂₂ = {(I ₂₂₂ / IA ₂₂₂ ) / T} × 100

Here, I ₁₁₀ , I ₂₀₀ , I ₂₁₁ ,
I ₃₁₀ and I ₂₂₂ are measured values of the X-ray reflection intensity of each crystal plane (c
ps) and I ₁₁₀ = 1.6K, I ₂₀₀ = 1.3K,
I ₂₁₁ = 2K, I ₃₁₀ = 0.1K, and I ₂₂₂ = 9.8K. Also, IA ₁₁₀ , IA ₂₀₀ , IA ₂₁₁ , IA ₃₁₀ ,
IA ₂₂₂ is the X-ray reflection intensity ratio of each crystal plane in the ASTM card, IA ₁₁₀ = 100, IA ₂₀₀ = 20, IA
₂₁₁ = 30, IA ₃₁₀ = 12, IA ₂₂₂ = 6. Further, T is calculated by T = (I ₁₁₀ / IA ₁₁₀ ) + (I ₂₀₀ / IA
₂₀₀ ) + (I ₂₁₁ / IA ₂₁₁ ) + (I ₃₁₀ / IA ₃₁₀ )
_{+ (I 222 / IA 222)} = is 1.79.

FIG. 8 is a photomicrograph showing the crystal structure of the surface of the underlayer 2 in Example 14. In FIG. 8 , a large number of trigonal pyramidal Fe crystals and hexagonal pyramidal Fe crystals are observed. These tri- and hexagonal pyramidal Fe crystals have a (hhh) plane, and therefore a {22} plane with a {22} plane facing the underlayer 2 surface side.
It is a 2｝ -oriented Fe crystal. In this case, the content S of the {222} oriented Fe crystals, Table 6, as shown in FIG. 7, S
= 91.2%. Further, the area ratio A ₁ of the trigonal pyramidal Fe crystal, that is, the pyramidal Fe crystal is A ₁ = 90%, and the area ratio A ₂ of the hexagonal pyramid Fe crystal is A ₂ = 60%.

Next, a coating layer 3 of MoS ₂ having a thickness of 10 to 20 μm was formed on the surface of each of Examples 1 to 16 of the underlayer 2 by a spray method.

On each coating layer 3, 100 grids each having a length of 1 mm and a width of 1 mm were carved so as to reach the surface of the base layer 2, and an adhesive tape (a tape specified in JIS Z 1522, width 18 mm, adhesive strength 2.94 N / 10 mm or more) was adhered, the adhesive tape was peeled off, and the adhesion state of the coating layer 3 was visually observed.

Based on this observation, the adhesion strength evaluation points in Tables 5 and 6 were determined, and Table 7 was used for the determination. The peeling area ratio B in Table 7 is expressed as (d / c) × 100%, where c is the area of the portion where the adhesive tape is stuck, and d is the area of the peeled portion.

[0041]

[Table 7]

FIG. 9 shows three of the first to sixth examples of the underlayer 2.
Hexagonal pyramidal Fe crystal, that is, area ratio A ₁ of pyramidal Fe crystal
And the relationship between the evaluation value and the adhesion strength evaluation point. In the figure, (1)-
(6) corresponds to Examples 1 to 6, respectively. From FIG. 9 , when the area ratio A ₁ of the pyramidal Fe crystal is set to A ₁ ≧ 40%,
It can be seen that the adhesion strength of the coating layer 3 to the underlayer 2 rapidly increases.

FIG. 10 shows the relationship between the area ratio A ₂ of the hexagonal pyramid-shaped Fe crystal and the adhesion strength evaluation point in Examples 2 to 16 of the underlayer 2. In the figure, (2) to (16) correspond to Examples 2 to 16, respectively. As apparent from FIG. 10, the cone-shaped F
In the area ratio A ₁ ≧ 40% of the e crystal, setting the area rate A ₂ of the hexagonal pyramid-shaped Fe crystals have a good wettability (hhh) plane to A ₂ ≧ 30% with respect to MoS ₂ coating, the lower adhesion strength of the coating layer 3 with respect to the formation 2 you greatly improved.

[0044] Incidentally, the inorganic crystals is not limited to the metal crystal, carbides having a body mind elevational Ho構 concrete, oxides, also includes ceramic crystal such as nitrides.

[0045]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide an underlayer capable of significantly improving the adhesion strength of the coating layer by the above-mentioned constitution.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a state in which a coating layer is formed on a base layer.

FIG. 2 is a schematic plan view of a main part showing a crystal structure of a surface of an underlayer.

FIG. 3 is a perspective view showing a body-centered cubic structure and its (hhh) plane.

FIG. 4 is an explanatory view of a crystal plane present on a slope of a triangular pyramid or hexagonal pyramid metal crystal.

FIG. 5 is an explanatory diagram showing an inclination of a (hhh) plane in a body-centered cubic structure.

FIG. 6 is an output waveform diagram of a power supply for electroplating.

FIG. 7 is an X-ray diffraction diagram of an underlayer.

FIG. 8 is a micrograph showing the crystal structure of the underlayer surface .
You.

FIG. 9 shows the relationship between the area ratio of pyramidal Fe crystals and the adhesion strength evaluation point.
It is a graph which shows a relationship.

FIG. 10 shows the area ratio of hexagonal pyramidal Fe crystals and the evaluation points of adhesion strength.
6 is a graph showing a relationship with the graph.

[Explanation of symbols]

Reference Signs List 1 steel plate (member) 2 underlayer 5 pyramidal metal crystal (pyramid inorganic crystal) 5 ₂ hexagonal pyramid metal crystal (inorganic crystal)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshikazu Fujisawa 1-4-1 Chuo, Wako-shi, Saitama, Honda R & D Co., Ltd. (56) Reference JP-A-4-371594 (JP, A)

Claims (4)

(57) [Claims] 1. A member (1) coating the base layer formed on the surface (2) is composed of an aggregate of inorganic crystal having a body mind elevational Ho構 granulation, the aggregate thereof, coated A plurality of pyramidal inorganic crystals (5), which are at least one of pyramidal inorganic crystals or truncated pyramidal inorganic crystals, are included to form the surface of the underlayer (2) to be subjected to An area ratio A ₁ of the pyramidal inorganic crystals (5) on the surface is A ₁ ≧ 40%. Wherein said conical inorganic crystals (5) is directed at mirror exponent (hhh) plane to the underlying layer surface (hh
h) The underlayer for coating according to claim 1, which is an oriented inorganic crystal. 3. The (hhh) oriented inorganic crystal includes:
The inclined surface includes a plurality of inorganic crystals (5 ₂ ) having a (hhh) plane at the Miller index, and the area ratio A ₂ of the inorganic crystals (5 ₂ ) on the surface of the underlayer (2) is A ₂ ≧ 30.
% Of the coating underlayer according to claim 2. 4. Before quinic machine quality crystals (5 ₂₎ sounds the hexagonal conical
The underlayer for coating according to claim 3 .