JP3030482B2 - Anticorrosion paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anticorrosion coating composition for protecting a metal member from a severe corrosive environment.

[0002]

2. Description of the Related Art A resin coating for covering the surface of a metal member to protect it from a corrosive environment is used for chemical equipment, tanks, bridges, and the like.
Widely used for ships, marine structures, etc. Corrosion of a metal protected by a coating film is initiated when corrosion factors such as oxygen, water, and chloride ions penetrate the coating film and reach the surface of the base metal. Therefore, the coating properties required for anticorrosion paints are:
It is excellent in blocking the permeation of corrosion factors (permeation resistance), and a sound adhesion state without peeling or cracking is maintained for a long period of time. Resins containing various pigments, for example, glass flakes, flaky inorganic pigments such as mica-like iron oxide (MIO), and rust-preventive pigments, for the purpose of improving the permeation resistance, strength, and adhesion of the coating film. Many proposals have been made on compositions and the like (JP-A-56-26965, JP-A-57-73056, JP-A-58-17177, etc.), and some of them have been put to practical use as commercial products. .

[0003]

[Problems to be Solved by the Invention] Recently, with the expansion and diversification of applications of anticorrosion paints, there is an increasing demand for improvement of coating film performance. Conventional anti-corrosion paints can be applied relatively easily by spraying, brushing, etc., but their durability, such as the ability to block permeation of corrosion factors, resistance to peeling and cracking, etc. cannot be said to be sufficient. Further improvement in membrane performance is desired. The present invention has excellent permeability blocking ability against corrosion factors,
Another object of the present invention is to provide an anticorrosion coating composition which exhibits good adhesion without causing blistering and peeling, and forms a coating film in which the anticorrosion function is stably maintained in a severe corrosive environment for a long period of time.

[0004]

The anticorrosive coating composition of the present invention is prepared by adding a resin having a length of 5 to 1 to a resin composition containing a resin and a resin curing agent.
00 μm, width 1-30 μm, thickness 0.01-2 μm,
The flaky potassium titanate particles having a flaky shape having a pect ratio (length / width) of 3 or more are 100 parts by weight of a resin solid content.
To 70 to 70 parts by weight . The anticorrosion paint composition of the present invention may optionally contain an anticorrosion pigment together with the flaky potassium titanate particles .

[0005]

[Function] The flaky potassium titanate particles have an extremely thin shape compared to the size (plane size), and due to its characteristic form, are more multilayered in the coating film than glass flakes or MIO flakes. As an effect of the multi-layer stacking, the ability to block the penetration of corrosion factors into the coating film is enhanced. Further, the flaky potassium titanate particles are excellent in the effect of reinforcing the coating film, strengthen the coating film in multiple layers, and greatly increase the strength of the coating film against the interfacial shear force. Furthermore, flaky potassium titanate particles are different from glass flakes and the like in that they have flexibility, so that they do not impair the bending and deformability of the coating film, but also swell the coating film, thermally and mechanically. Absorbs and relaxes internal stress caused by mechanical deformation, and is effective in preventing cracking and peeling. As a compounding effect of the flaky potassium titanate particles, the anticorrosion function of the coating film is enhanced,
And is maintained stably. The anticorrosion effect of the coating film can be further improved by using it in combination with a known anticorrosion pigment.

Hereinafter, the components of the coating composition of the present invention and the preparation of the coating composition will be described in detail. The flaky potassium titanate particles blended in the resin have the general formula: K ₂ O · n
It is a crystalline synthetic inorganic compound (polycrystalline) represented by TiO ₂ . Among them, potassium tetratitanate [K ₂ Ti
₄ O ₉ ], potassium hexatitanate [K ₂ Ti ₆ O ₁₃ ], potassium octa titanate [K ₂ Ti ₈ O ₁₇ ] and the like are preferably used because of their excellent thermal stability, reinforcing property and the like. You.
These flaky potassium titanate particles may be used alone or in a combination of two or more.

The size of the flaky potassium titanate particles is as follows:
If it is too coarse, dispersibility and workability in paint preparation will be poor. Conversely, for ultrafine particles, the specific surface area will increase and the oil absorption (JI
With an increase in S K5101), the tendency of the paint to thicken becomes remarkable, and the permeation resistance as a multilayer laminating effect in the coating film and the effect of reinforcing the coating film are unfavorably weakened. When the thickness is too large, the overlap of the multilayers in the coating film is impaired, causing a decrease in permeation resistance. On the other hand, when the thickness is too small, the strength of the flaky particles becomes poor, and During the kneading preparation, the flake shape is easily damaged. From these points, the flaky particles have a size (size in the surface direction) of about 1 to 100 μm.
Preferably, the one having a thickness of about 0.01 to 2 μm is used. About the size, length about 5-100μm,
About 1 to 30 µm in width, aspect ratio (length / width)
Having a form of about 3 or more is particularly preferable in terms of the anticorrosion enhancing function, the reinforcing function, and the like as the flake shape effect.

The amount of the flaky potassium titanate particles in the resin composition is about 10 parts by weight or more based on 100 parts by weight of the resin solid content in order to sufficiently exhibit the above-mentioned effect of improving the coating film performance. Is preferred. However, if the amount is too large, the preparation of paint and the workability of coating will be reduced, and it will cause pinholes in the coating film. Therefore, it is appropriate to set the upper limit to about 70 parts by weight.

A resin composition containing flaky potassium titanate particles comprises a resin and a curing agent capable of reacting with a reactive group contained in a molecule of the resin to form a crosslinked structure (crosslinking agent or crosslinking reaction initiation). An accelerator, a polymerization initiator and an accelerator). The resin is, for example, an epoxy resin, an unsaturated polyester resin, a polyol resin,
Epoxy acrylate resin, polybutadiene resin and the like. Among these resins, epoxy resins and unsaturated polyester resins are preferably used from the viewpoint of room temperature curability, workability on site, cost and the like.

[0010] Epoxy resins have at least two components per molecule.
Those containing two epoxy groups are used. Examples thereof include bisphenol type epoxy resins, phenol novolak type epoxy resins, polyglycol type epoxy resins, ester type epoxy resins, aliphatic type epoxy resins, and aromatic type epoxy resins. An epoxy resin having a structure similar to these or a derivative thereof (eg, a polyol-type epoxy resin, an alicyclic epoxy resin, a halogen-containing epoxy resin, etc.) is also used. As the curing agent for the epoxy resin, various amino compounds, polyamide resins, isocyanate compounds, phenol resins, acid anhydrides, melamine resins, urea resins, and the like, which are generally used as curing agents for epoxy resins, are arbitrarily used. Also known unsaturated polyester resin is optionally used,
As the curing agent, for example, a polymerization initiator such as a peroxide (peroxides, peroxyesters, etc.) and, if necessary, a polymerization accelerator for amines, fatty acid metal salts (cobalt naphthenate, etc.) are used. You.

[0011] The coating composition of the present invention, together with the flaky potassium titanate particles, various components known as anticorrosive pigments, for example, zinc dust, aluminum powder, red lead, lead suboxide, cyanamide lead, basic chromate. The anticorrosive effect of the coating film can be further enhanced by compounding one or more selected from the group consisting of, zinc molybdate, lead chromate, zinc phosphate and the like. The compounding amount is suitably in the range of about 5 to 100 parts by weight with respect to 100 parts by weight of the resin solids.

In preparing the resin composition of the present invention, various additives usually used in this type of coating composition, for example, extender pigments such as talc, silica, precipitated barium sulfate, calcium carbonate, perlite, and oxidized Color pigments such as iron, zinc white, red iron oxide, chromium oxide, titanium oxide, carbon black, iron black, etc., other precipitation inhibitors, thickeners, defoamers, anti-sagging agents, surfactants, surface conditioners, diluents , A solvent (eg, methyl isobutyl ketone, xylol) and the like are added in appropriate amounts as necessary.

The coating composition of the present invention comprises a base resin such as an epoxy resin or an unsaturated polyester resin, flaky potassium titanate particles, and if necessary, an anticorrosive pigment, various additives, a diluent, a solvent and the like. It is prepared by mixing, kneading and dispersing with a mixer such as a roll mill, and mixing a curing agent and a curing accelerator at the time of use. The coating film is formed by a standard method such as brush, roller, air spray, airless spray, etc.
This is performed by applying the solution to the surface of the target member and drying the applied material. The coating thickness may be about 300 to 700 μm as a dry film thickness.

[0014]

EXAMPLES [1] Preparation of coating composition A resin composition having the component constitution shown in Table 1 was prepared. The addition of the zinc powder in the main agent and the mixing of the main agent and the curing agent were performed immediately before the start of coating. In Table 1, Nos. 1 to 5 are invention examples using flaky potassium titanate particles as fillers, and Nos . 11 to 14 are comparative examples. Comparative Examples No. 11 and 12
Contains flaky potassium titanate particles, but N
Insufficient amount of o.11 (6 weight per 100 parts by weight of resin solids)
Parts), No. 12 is excessive (80 parts per 100 parts by weight of resin solids)
Parts by weight). No.14 and No.15 are examples using glass flakes or MIO flakes (conventional type)
It is. Epoxy resin (bisphenol-type epoxy resin): "Araldite 6071" manufactured by Ciba-Geigy Japan Ltd. Flaky potassium titanate particles (potassium hexatitanate): "TXAX-SA" manufactured by Kubota Corporation (length 40 μm, width 10 μm, thickness
0.5 μm, weight-based cumulative distribution average value) Mica: “Kuraray Mica 200-” manufactured by Kuraray Co., Ltd.
C "MIO flake:" MIO- manufactured by Nippon Inorganic Chemical Industry Co., Ltd.
NF "

[2] Film formation Mild steel plate [JIS G3141, "SPCC"] (150 × 150 × 1.6, mm)
Is used as a paint test plate, the plate surface is subjected to a base treatment by sand blasting (removal of mill scale, rust, oil, etc.), degreased and washed, and then the paint composition is coated with an air spray gun to obtain a coating film thickness (dry film thickness). ) Was 500 ± 20 μm, and was dried at 20 ° C. and 75% RH for 7 days.

[3] Coating film performance test The following test was carried out in accordance with the provisions of JIS K5400 “General Paint Test Method”, and the results shown in Table 2 were obtained. (3.1) Salt spray test: A cross cut is made on the coating film surface, a salt spray test is performed, and the elapsed time until rust progresses from the cut portion to below the coating film is measured. (3.2) Wetness test: The test plate was subjected to 1% under the condition of 100% RH.
After leaving for 000 hours, the surface of the coating film is visually observed for any abnormal occurrence (swelling, rust, etc.). (3.2) Accelerated weathering test: A crosscut was made on the surface of the coating film, and subjected to a sunshine weather-o-meter test.
After the elapse of r, the film is bent using the coating film bending tester so that the coating film surface is outside (bending core diameter: 6 mm, bending angle:
180 °), and visually observe the state of the coating film (whether peeled or cracked).

As shown in Table 2, the coating film formed by the coating composition of the invention containing a predetermined amount of flaky potassium titanate particles has a coating film having salt spray resistance, moisture resistance, weather resistance and the like. The performance is excellent, and the difference from the performance of a conventional type coating film using glass flakes or MIO flakes is obvious. N
o.11 and No.12 contain flaky potassium titanate particles
However, due to the shortage or excess of the compounding amount, the coating film
The performance improvement effect is insufficient.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

The coating film formed by the coating composition of the present invention has the following effects as a compounding effect of the flaky potassium titanate particles.
It has excellent anticorrosion effect, has little deterioration of coating film such as cracks and peeling, and maintains good anticorrosion effect for a long period of time, and is used for chemical equipment, piping systems, tanks, bridges, ships, marine structures It is useful for protecting metal members exposed to severe corrosive environments such as objects.

Continuation of front page (56) References JP-A-61-118465 (JP, A) JP-A-4-337344 (JP, A) JP-A-1-170670 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) C09D 5/08 C23F 11/18 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A resin composition comprising a resin and a resin curing agent ,
Length 5-100μm, width 1-30μm, thickness 0.01-2
μm, flake shape with aspect ratio (length / width) 3 or more
Flaky potassium titanate particles having the solid content of the resin 1
An anticorrosion coating composition characterized in that it is added in an amount of 10 to 70 parts by weight based on 00 parts by weight . 2. The anticorrosion coating composition according to claim 1, wherein an anticorrosion pigment is added to the resin composition together with the flaky potassium titanate particles.