JP2003306638A - Zinc rich paint composition - Google Patents

Abstract

(57) [Problem] To provide a zinc rich paint composition which gives a coating film particularly excellent in rust prevention and is excellent in bolting joining of steel materials. A zinc rich paint composition comprising (A) zinc powder, (B) an alkyl silicate condensate-butyral resin binder, and (C) a pigment composed of a needle pigment or a high-hardness pigment. To do.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zinc rich coating composition which is excellent in rust prevention and is suitable for bolting and joining steel materials.

[0002]

2. Description of the Related Art Generally, zinc-rich paints containing a large amount of zinc powder in the form of powder or granules or fine flakes in a binder are often used for corrosion and rust prevention of steel materials. This zinc-rich paint protects the steel material coated with the zinc while gradually depleting the zinc by utilizing the fact that zinc is electrically baser than iron, that is, it has a large ionization tendency and is easily oxidized. is there. The zinc-rich paint is also applied to the bolted joint of the steel material particularly to the joint surface in order to increase the sliding frictional force of the joint surface. In such a case, the zinc-rich paint has a slip coefficient of 0. 4 to 0.5 are general, and such a general one has a small slip coefficient, so that the size of the reinforcing material such as the splicing plate used for the joint portion of the steel material is increased for safety, There was no choice but to increase the number of bolts to tighten, which made the work complicated and costly. On the other hand, a special one having a slip coefficient of more than 0.5 can be obtained, for example, by a method in which zinc dust has a particle size distribution to increase the denseness or the denseness to improve the adhesion.
It is not always satisfactory enough, and its effect is too costly and economical.

[0003]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the conventional zinc-rich coating composition, provides a coating film excellent in rust prevention, and is excellent in bolting and joining steel materials. It is made for the purpose of providing a zinc rich coating composition.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have conducted various studies to develop a zinc-rich coating composition having the above-mentioned preferable properties. As a result, zinc powder is added to an alkyl silicate condensate-butyral resin system. It has been found that the object can be achieved by blending a binder and a needle-shaped pigment or a high hardness pigment, and the present invention has been completed based on this finding.

That is, the present invention contains (1) (A) zinc dust, (B) alkyl silicate condensate-butyral resin binder, and (C) a needle pigment or a pigment comprising a high hardness pigment. And a zinc rich coating composition comprising the following. In the present invention, the zinc dust means zinc or powder or fine flakes of zinc-based alloy, that is, zinc-based alloy, and the pigment may have needle-like shape and high hardness. included.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In a preferred embodiment of the present invention,
(2) The zinc rich coating composition according to (1) above, wherein the zinc powder as the component (A) has an average particle size of 1 to 50 μm,
(3) The ratio of the alkyl silicate condensate to the butyral resin in the binder as the component (B) is 60:40 in mass ratio.
To 95: 5, the zinc rich coating composition according to (1) or (2) above, and (4) the acicular pigment has a major axis of 5 to 20.
The zinc rich coating composition according to the above (1), (2) or (3) having a thickness of 0 μm and an aspect ratio of 10 to 200, and (5) the acicular pigment is acicular calcium carbonate or acicular aluminum borate. The zinc rich coating composition according to any one of (1) to (4), (6) the high hardness pigment having a Mohs hardness of 7 or more (1), (2)
Alternatively, the zinc-rich coating composition according to (3), the compounding ratio of (7) is 50 to 93% of the component (A) on a mass basis,
The zinc rich coating composition according to any one of (1) to (6) above, which is in the range of 5 to 35% (B) component and 2 to 15% (C) component.

In the coating composition of the present invention, the zinc powder as the component (A) of the composition is not particularly limited as long as it is one usually used in coating compositions, but the average particle size is preferably 1 ˜50 μm, preferably 2-45 μm,
More preferably, powder of 3 to 40 μm or average diameter of 3 to 3
Flakes having a thickness of 0 μm and an average thickness of 0.5 to 2 μm have good sedimentation properties and are preferable in coating work.

Further, in the alkyl silicate condensate-butyral resin binder of the component (B), the alkyl silicate condensate also includes its modified product, so long as it is usually used for inorganic zinc rich paints. Although not limited, preferred examples include ethyl silicate hydrolyzed condensates, methyl silicate hydrolyzed condensates, and alkoxy modified products thereof (for example, trimethoxy modified product, triethoxy modified product, etc.).

The butyral resin is not particularly limited as long as it is one usually used in zinc-rich paints, but one having a low molecular weight, particularly one having a molecular weight of 20,000 or less is preferable.

The proportion of the alkyl silicate condensate and the butyral resin in the binder of the component (B) is usually 60:40 to 95: 5, preferably 70:30 to 90:10 by mass ratio. Preferably from 75:25
It is selected in the range of 85:15. If this ratio is lower than 60:40 and the amount of butyral resin is too much, the coating film becomes soft and the rust preventive power and solvent resistance of the coating film are deteriorated.
If it is higher than 5: 5 and the amount of butyral resin is too small, the amount of dust generated during coating increases and the adhesion strength to the material decreases.

As the pigment as the component (C), it is essential to use a needle-shaped pigment or a high-hardness pigment, that is, one of a needle-shaped pigment and a high-hardness pigment. The slip coefficient can be improved at the bolted joint where the object is applied to the joint surface. As the needle-like pigment, those having a major axis of 5 to 200 μm and an aspect ratio of 10 to 200, preferably 20 to 150 are preferable, and examples of the material thereof include calcium carbonate, aluminum borate, zinc white, and the like. One kind may be used, or two or more kinds may be used in combination. As the high hardness pigment, one having a Mohs hardness of 7 or more is used, and examples thereof include quartz, yellow stone, corundum, diamond and the like, and these may be used alone or in combination of two or more. You may use it in combination.

In the coating composition of the present invention, it is preferable to add a solvent usually used for the zinc-rich coating composition because the composition components can be dissolved or dispersed. Such solvents include alcohols such as 2-propanol and butanol, glycol ethers such as 1-methoxy-2-propanol, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and cyclohexanone, acetic acid. Esters such as ethyl, butyl acetate, propylene glycol monomethyl ether acetate and the like can be mentioned.

In the coating composition of the present invention, the preferable blending ratios of the component (A), the component (B) and the component (C) are 50 to 93% of the component (A) and 5 of the component (B) on a mass basis. -35% and (C) component 2-15%, preferably (A) component 55-88%, (B) component 10-32% and (C) component 2-13%, more preferably (A) component 60.
~ 84%, (B) component 13 to 30% and (C) component 3 to
It is selected in the range of 10%.

If the amount of the component (A) is less than the above range, the rust preventive power of the coating film is lowered and a sufficient rust preventive effect cannot be expected, while if it is too large, the coating workability is deteriorated and a uniform coating film is obtained. Is not obtained, and the adhesion of the coating film to the material is reduced.

If the amount of component (B) is less than the above range, it becomes a dust spray at the time of coating, and the adhesion of the coating film to the material is lowered, and if it is too large, it causes rust prevention of the coating film and solvent resistance. Membrane performance is also reduced.

If the amount of the component (C) is less than the above range, a coating film having a high slip coefficient cannot be obtained, and if it is too large, the stability of the coating composition deteriorates and the coating workability also deteriorates.

In the coating composition of the present invention, if necessary, an additive component usually used in the coating composition, such as an extender pigment, an anticorrosive pigment, a coloring pigment, or an anti-sag agent, is used as long as the object of the present invention is not impaired. Agents, film-forming aids, wetting agents, defoamers, antifreeze agents, leveling agents, dispersants, antisettling agents, plasticizers, flameproofing agents, antifungal agents, ultraviolet absorbers, antioxidants, surface adjustment Agents, surfactants, stabilizers and the like can be added.

Examples of extender pigments include silica, talc, clay, kaolin, mica, zinc white, barium sulfate, calcium carbonate, alumina, zinc oxide, magnesium carbonate, barium carbonate, bentonite, etc., preferably talc, Zinc oxide, calcium carbonate, mica and barium sulfate are used.

Examples of the rust preventive pigment include, for example, chromium pigments, lead pigments, borate pigments, phosphate pigments, molybdate pigments, and the like. Phosphate pigments and molybdate pigments are used because they can be improved. Examples of the phosphate-based pigment include zinc phosphate, aluminum phosphate, calcium phosphate, aluminum zinc phosphate, calcium zinc phosphate, zinc phosphorus silicate, zinc-treated polyaluminum phosphate, and molybdate pigments. Examples thereof include calcium molybdate, aluminum phosphomolybdate, zinc molybdate, zinc calcium molybdate, and zinc phosphomolybdate.

Examples of the color pigments include red iron oxide, titanium white, carbon black, aniline black, Gunjou, cadmium yellow, chrome yellow, lead white, watching red, organic blue such as cyanine blue, and organic green such as phthalocyanine green. To be Examples of anti-settling agents include organic bentonite, polyethylene oxide, aerosil and the like.

The coating composition of the present invention is practically provided in the form of a two-can set in which the coating liquid and a mixture of zinc dust and a predetermined pigment are separately provided. In the case of such a set form, At the time of coating on a predetermined steel material, each can component of the above set may be sufficiently mixed and stirred by a stirrer or the like to be homogenized before use. For painting steel materials, spraying, dipping, brushing,
A normal coating method such as mechanical coating with a suitable coater such as a roll coater may be used, and the drying after coating may be natural drying or hot air drying. When the coating composition of the present invention is used for a steel material that can be bolted, which is particularly made of zinc alloy plated steel and / or zinc alloy plated steel such as zinc-aluminum alloy plated steel and zinc-aluminum-magnesium alloy plated steel. It has excellent corrosion resistance, rust resistance, and bolt tightening bondability.

[0022]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The slip coefficient for the test specimen is
Obtain the load that caused slippage by the tensile test of the test piece,
It was calculated from this load and the bolt tightening load.

Comparative Example 1 First, a coating composition was prepared as follows. That is, 20 parts by mass of ethyl silicate ES-40 (trade name, manufactured by Tama Chemical Co., Ltd., alkyl silicate condensate) as a binder,
LS-2 [trade name, manufactured by Mitsui Kinzoku Kogyo Kagaku KK, zinc powder (average particle size 8.5 μm)] 65 parts by mass, W.I. G Mica C-
A uniform coating composition was prepared by thoroughly mixing and stirring 5 parts by mass of 1000 (trade name, potassium aluminum silicate manufactured by KMG Minerals) and 10 parts by mass of a methoxypropanol-isobutanol (mass ratio 1: 1) mixed solvent. Next, this coating composition was applied to a blast-treated steel plate (treatment grade ISO Sa 2.5) to obtain a dry film thickness of 75 μm.
It was applied so that it would be, and naturally dried for 2 weeks. Two coated steel plates thus obtained were attached to the outer surfaces of the two splicing plates, and a high-strength bolt was used to make a tightening test specimen at F10T. The slip coefficient of this test piece was measured and found to be 0.48.

Comparative Example 2 In place of the binder of Comparative Example 1, ethyl silicate ES-40 was used.
(Product name, Tama Chemical Co., alkyl silicate condensate)
A coating composition was prepared in the same manner as in Comparative Example 1 except that 16 parts by mass and 4 parts by mass of S-REC BL-1 (trade name, butyral resin manufactured by Sekisui Chemical Co., Ltd.) were used to prepare test samples. . When the slip coefficient of this test piece was measured, it was 0.54.

Example 1 Whiskers AS instead of WG Mica C-1000
-4 [trade name, manufactured by Shikoku Kasei, acicular calcium carbonate pigment (major axis 20 to 30 μm, average aspect ratio 40)] was used to prepare a coating composition in the same manner as in Comparative Example 2,
A test body was created. The slip coefficient of this test piece was measured and found to be 0.64.

Example 2 DCR100F in place of WG Mica C-1000
[Product Name, Yakushima Electric Works, Silicon Carbide Pigment (# 10
0)] was used and a coating composition was prepared in the same manner as in Comparative Example 2 to prepare a test body. The slip coefficient of this test piece was measured and found to be 0.64.

Example 3 A coating composition was prepared in the same manner as in Example 1 except that the zinc powder was changed to coarse-grained LS-30 (trade name, manufactured by Mitsui Kinzoku Kagaku Kagaku KK, average particle diameter 35 μm). A test body was created. The slip coefficient of this test piece was measured and found to be 0.67.
Met.

Example 4 A coating composition was prepared in the same manner as in Example 2 except that the zinc powder was changed to coarse-grained LS-30 (trade name, manufactured by Mitsui Metal Coating Chemicals Co., Ltd., average grain size 35 μm). A test body was created. The slip coefficient of this test piece was measured and found to be 0.67.
Met.

From the above results, it was confirmed that the predetermined pigment was used not only when the coating composition of Comparative Example 1 was used but also when the coating composition of Comparative Example 2 having a higher slip coefficient was used. When the coating compositions of Examples 1 and 2 prepared and used were used, the sliding coefficient was improved, and the coating compositions of Examples 3 and 4 prepared by using coarser zinc dust than those of Examples 1 and 2. It can be seen that the slip coefficient is slightly improved when the material is used.

[0030]

The zinc-rich coating composition of the present invention is excellent in rust prevention and excellent in bolting and joining of steel materials, and particularly when applied to the joining surface at the bolting and joining portion of steel materials, it can enhance the sliding friction force. it can. Therefore, the zinc-rich coating composition of the present invention is particularly composed of galvanized steel or galvanized steel, which can be bolted to steel structures or steel structures such as roads, bridges, railways, ports, buildings, factories, and prefabricated structures. It is suitable for applications such as houses, power plants, steel towers, amusement parks, pools, and other entertainment / amusement facilities where corrosion protection is required.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masaki Iwasaki             2-14-35-3 Kurosuna, Inage-ku, Chiba-shi, Chiba Prefecture (72) Inventor Daisuke Aoki             Bell, 1-3 Inage Beach, Mihama-ku, Chiba City, Chiba Prefecture             View Inage 1-403 (72) Inventor Yoshinobu Konno             1456 Hazamacho, Hachioji City, Tokyo Co., Ltd.             In ThreeBond (72) Inventor Mitsuhiro Kiyota             369-2 Ebensu, Narita City, Chiba Prefecture (72) Inventor Hiroshi Nakayama             173-95 Naganuma-cho, Inage-ku, Chiba-shi, Chiba Prefecture F-term (reference) 4J038 CE071 DL021 HA066 HA286                       HA47 KA08 NA03 PC02                 4K062 AA01 BA08 BA14 BA20 BB01                       BB03 BB04 BB05 BB09 BC11                       CA05 CA10 FA08 FA11 FA12                       GA01

Claims (7)

[Claims] 1. A zinc rich coating composition comprising (A) zinc dust, (B) alkyl silicate condensate-butyral resin binder, and (C) a needle pigment or a pigment comprising a high hardness pigment. . 2. The zinc powder of component (A) has an average particle size of 1 to 50.
The zinc-rich coating composition according to claim 1, which has a thickness of μm. 3. The ratio of the alkyl silicate condensate and the butyral resin in the binder as the component (B) is 6 by mass ratio.
The zinc rich coating composition according to claim 1 or 2, which is 0:40 to 95: 5. 4. The zinc-rich coating composition according to claim 1, wherein the acicular pigment has a major axis of 5 to 200 μm and an aspect ratio of 10 to 200. 5. The zinc rich coating composition according to claim 1, wherein the acicular pigment is acicular calcium carbonate or acicular aluminum borate. 6. The zinc-rich coating composition according to claim 1, 2 or 3, wherein the high hardness pigment has a Mohs hardness of 7 or more. 7. A component (A) component 5 on a mass basis.
0-93%, (B) component 5-35% and (C) component 2-
The zinc rich coating composition according to any one of claims 1 to 6, which is in the range of 15%.