JPS6044350B2 - Anticorrosive coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-corrosion coating composition that can form a tough film with excellent weather resistance and anti-corrosion properties on steel.

Conventionally, resin coatings (linings) for the purpose of preventing corrosion and rust of metal have been widely used mainly in various pollution control devices and chemical equipment, as well as tanks, oil tanks of ships, ship bottoms, etc. The resin used for these resin linings is unsaturated polyester resin from the viewpoints of room temperature curability, on-site workability, and cost.The lining method is FRP lining, that is, organic filtration is added to the resin in advance before lining construction. Mix oxides, apply a sheet-like base material made of glass fiber to the matrix to be lined, impregnate it with the resin using a felt roll or the like, and simultaneously defoam it,
It was common practice to harden it.

Recently, in addition to this method, a method that has been attracting attention is a method in which a composition made by blending extremely thin glass flakes with resin instead of glass fiber is applied to the object using a core, etc.
Flake lining) is already in practical use.

For example, such compositions include a protective and decorative coating composition containing fine glass flakes in an organic resin binder vehicle (Japanese Patent Publication No. 51-25368), or a corrosion-resistant coating composition in which a lining resin is included. A lining material filled with glass flakes as a reinforcing material and glass fiber as a reinforcing material (Japanese Unexamined Patent Publication No. 1983-30855) is known, and it is also possible to treat the surface of flaky glass with an appropriate substance. This gives hydrophobicity and leafing properties to plastics, paints, insulating paper, etc.
-16821) is also known.

The application of the above composition was carried out in accordance with 2.
-There are ultra-thick films, and the construction costs are very high. Therefore, they are not often applied to general steel structures, and are currently used for very limited special purposes as mentioned above. be.

Considering the cost, we decided to use 2wr flake lining, which is currently used as a lining material. When used in a film with a thickness of n or less, it was impossible to obtain a desired coating film performance and could not withstand practical use.

In particular, when used as a thin film, rust was generated from pinholes in the film, which was a serious problem.

In other words, rust that occurs in the pinhole area grows rapidly, and rust does not only occur in the pinhole area, but also progresses from that area between the coating and the base steel, and eventually leads to large defects such as blistering and peeling of the coating. It becomes. In addition, when used for bridges, marine structures, etc., it is necessary to have a color that matches the purpose of the object to be coated, so it is necessary to use the above-mentioned lining material mixed with colored pigments, or After the above-mentioned lining material is applied, a top coat of rethane-based, acrylic-based, or chlorinated rubber-based paint is applied. However, films made from ordinary colored pigments discolor or fade after long-term use, so they cannot be used as lining materials in applications where a durability of 20 to 3 years, and in some cases 50 to 6 years, is required. During that period, the surface had to be repainted several times. The present invention eliminates the various drawbacks of the prior art as described above, and can provide a durable film with excellent rust prevention, adhesion, impact resistance, weather resistance, etc., and has long-term resistance to discoloration and fading. The present invention relates to an anticorrosion coating composition having the following properties.

That is, the present invention relates to an anticorrosion coating composition comprising 100 parts by weight of epoxy resin, 10 to 15 parts by weight of glass flakes uniformly colored throughout, and the required amount of hardener.

The epoxy resin used in the present invention has two or more epoxy groups in its molecule, usually located at both ends of the molecule, and is one commonly used for paints.

Examples of the epoxy resin include, for example, bisphenol type epoxy resins such as Epicote 828, Epikote 834, and Epikote 83 manufactured by Shell Chemical Co., Ltd., which are generally commercially available.
6. 1001, 1004, DX-255: Araldite GY-260, manufactured by Ciba Geigy Co., Ltd.; DER33O, 331, manufactured by Dow Chemical Co., Ltd.
, 337: Trade name: Epiclon 80, manufactured by Dainippon Ink and Chemicals Co., Ltd.: Trade name: DEN43l, manufactured by Downy Chemical Co., Ltd., which is generally commercially available as a phenol borax type epoxy resin, 438: Polyglycol type Ciba Geigy Co., Ltd., which is commercially available as an epoxy resin
Product name Araldite CT-508: Dow Chemical (
DER-732 and DER-736 manufactured by Dainippon Ink Chemical Co., Ltd. as ester-type epoxy resins; for example, as Epiclon 200 and DER-400 manufactured by Dainippon Ink and Chemicals; linear fatty acid epoxy resins such as Nippon Soda Co., Ltd. For example, epoxidized polybutadiene such as BF-1000 (trade name) manufactured by ) may be used.

Furthermore, epoxy compounds that are easily analogous to these resins and derivatives of the above-mentioned epoxy resins can be similarly used and are included within the technical scope of the present invention.

Examples include polyol type epoxy resins, alicyclic epoxy resins, halogen-containing epoxy resins, and the like.

The glass flakes (hereinafter referred to as glass flakes) that are uniformly colored throughout and used in the anticorrosive coating composition of the present invention have a thickness of 0.5 to 10 μm, preferably 1 to 6 μm, and a size of 100 μm.
They are glassy, extremely thin colored flat particles with a size of ~400μ, preferably 150~300μ, and are uniformly colored not only on the surface but also inside.

The colored glass flakes are layered in parallel to the material within the film, increasing the strength of the resin, and at the same time blocking the penetration of external vapors, moisture, and other environmental agents, as well as blocking ultraviolet rays. to shield. Furthermore, since the colored glass flakes have almost no deterioration due to ultraviolet rays, there is no discoloration or fading of the coating film using the colored glass flakes, and therefore, the effect is that the original color is maintained. Generally, the thinner the colored glass flakes are and the larger the diameter, the greater the inhibition effect, and this tendency is more pronounced in severe corrosive environments.
In the present invention, the mixing ratio of the epoxy resin and the colored glass flakes is such that 10 to 150 parts by weight (especially preferably 20 to 60 parts by weight) of the colored glass flakes have good corrosion resistance and weather resistance for 100 parts by weight of the resin (solid content). Alternatively, it is suitable from the viewpoint of physical properties.

In the above mixing ratio, if the amount of colored glass flakes is less than 10 parts by weight, the desired corrosion resistance or weather resistance of the coating film cannot be obtained, and conversely, if it exceeds 150 parts by weight, the flexibility of the coating will deteriorate. This is not preferable because it deteriorates and becomes brittle.

The composition of the present invention is used in combination with a curing agent, a curing accelerator, etc. in a conventional manner. As the curing agent for epoxy resins of the present invention, those commonly used for paints, such as amine adducts and polyamide resins, can be used.

Examples of the curing agent used in the present invention include Tomide Y-25 and Tomide 245, both commercially available polyamide resins manufactured by Fuji Kasei Kogyo Co., Ltd. 2400, 2500: Product name: Xenamide 20 manufactured by Daiichi General Co., Ltd.
00, Versamide 11\Versamide 125: Sanwa Chemical Co., Ltd., product name Sanmide 320, Versamide 330, Versamide X2OOO: Ciel Chemical Co., Ltd. product name Epicure 325! l). Same 4
255: Fuji Chemical Industry Co., Ltd. as amine adduct resin
Product name: Tomide 238s Fujikyure 202: Asahi Denka Co., Ltd., product name: Adeka Hardener EH-531: As an aliphatic polyamine, Sanwa Chemical Co., Ltd., product names: Sanmide T-100, D-100, P-100: Epomate B-00 manufactured by Ajinomoto Co., Inc. as a heterocyclic diamine derivative
2, C-002 and S-005.

The amount of the curing agent added to the epoxy resin is approximately equivalent, that is, approximately 0.7 to 1.3 equivalents per equivalent of the epoxy resin.

Furthermore, extender pigments, anti-settling agents, dispersants, diluents, solvents, and other flat pigments can be added to the composition of the present invention, if necessary.

The composition of the present invention thus obtained can be applied by brush, roller,
After being applied to a copper material by a normal method such as air spraying to a film thickness of 2- or less, preferably 300p or more,
Dry 4 at room temperature or by heating. The coating film obtained after drying has excellent properties such as strength, corrosion resistance, and weather resistance. The present invention will be explained below using detailed examples and comparative examples.

Example 1 Formulation 1 (Main agent) Part by weight Bisphenol type epoxy resin [Product name 45.0 Epicote 82
8 Shell Chemical Co., Ltd.: Epoxy resin equivalent weight 184-19
4] Colored glass flakes* (average size 30.0150
~200μ, thickness 3-5μ) Anti-settling agent (organic bentonite) 2.0 Methyl isobutyl ketone
10.0 xylol
13.0・10
0.0 (hardening agent) Polyamide resin [Product name: Tomide
75#245 manufactured by Fuji Kasei Gyo Co., Ltd., active hydrogen equivalent: 90] Isobutanol 25100.
0*Preparation of colored glass flakes The above composition was placed in a crucible and heated and melted at 1200 to 1300°C to produce colored glass.

After attaching the above molten glass to the tip of a small diameter vibrator,
Air was blown from the opposite side to inflate it into a balloon shape, and then it was cooled.The balloon-shaped colored glass was then crushed, and the crushed colored glass was classified using a sieve to produce colored glass flakes.

After mixing the epoxy resin and anti-settling agent in the base material and kneading with a roller, other components were added and stirred with a disper to create a base material. A paint was prepared by mixing 8 parts of the base agent and 2 parts of the curing agent. Then, 150 x 50 x 1.6T
R1N mild steel plate (JIS-G-3141) was shot blasted to completely remove black scale, rust, and oil, and then air-sprayed with a paint containing the main ingredient of Formulation 1 with a hardening agent added to a dry film thickness of 500. It was coated to a thickness of ±50μ, dried for 7 days, and then subjected to a comparative test. Example 2 Formulation 2 (Main agent) Bisphenol type epoxy resin [Product name Epicote 10
01 Shell Chemical Co., Ltd.: Epoxy equivalent 450-500
] 55 parts by weight colored glass flakes (
Same as Example 1) 2
Saliva sedimentation prevention agent (same as Example 1) 2.0 Methyl isobutyl ketone 10 Xylol
13100.0 (curing agent) Amine adduct resin [trade name Tomide 238 manufactured by Fuji Kasei Kogyo Co., Ltd.: amine value 230] 70 butanol
3 weighing section
100.0 A sample prepared in the same manner as in Example 1 was coated with the composition of Formulation 2, which was kneaded in the same manner as in Example 1, and subjected to a comparative test.

Example 3 Formulation 3 (Main agent) 4 parts of phenol volak type epoxy resin [Product name D
EN43l Dow Chemical: Epoxy equivalent 172-17
9] Colored glass flakes (same as Example 1) 30 Antisettling agent 2.0 Methyl isobutyl ketone 10 Xylol
18100.0 (curing agent) The same one as in Example 2 was used.

A sample prepared in the same manner as in Example 1 was coated with the composition of Formulation 3, which was kneaded in the same manner as in Example 1, and dried, and subjected to a comparative test.

Comparative Example 1 Blend 4 (Main ingredient) Isophthalic acid-based unsaturated polyester resin [Rigolak 1
50HR: Manufactured by Showa Kobunshi Co., Ltd. 45 parts by weight Product name] Organic bentonite 2.5 styrene
26.7 Azo red pigment
10.0 Cobalt naphthenate (6%
Glass flakes (containing metal 0.8 cobalt) (average size 15150-200μ, thickness 3-5μ)
100.0 (curing agent) Methyl ethyl ketone peroxide 0.6 The composition of Formulation 4 above was coated on a specimen prepared in the same manner as in Example 1 so that the dry coating thickness was 500 ± 50μ,
After drying at room temperature for 7 days, it was subjected to a comparative test.

Comparative Example 2 (Main ingredient) Part by weight Bisphenol type epoxy resin 45.0 (same as Example 1) Colored glass powder Note 130.0 Anti-settling agent (organic bentonite) 2.0 Methyl isobutyl ketone 10.0 Xylol
13.0100.0 (curing agent) Polyamide resin (same as Example 1) 75.0 Isobutanol 25.0100.0
Note 1) Preparation of colored glass powder Glass flakes made of acid-resistant alkali-containing glass with an average size of 150 to 200 microns and an average thickness of 3 to 5 microns, 10 parts of chromium oxide, 2 parts of chromium oxide
parts by weight and 2 parts by weight of a condensed aluminum phosphate-based inorganic binder were mixed and heated at 500°C for 1 hour to obtain a green lump.

Grind this in a mortar and pass through a sieve to an average size of 150.
A powder of ~200 microns was obtained. When this powder was examined under a microscope, it was found to be irregularly shaped granules. Using the colored glass powder prepared above, a paint was prepared by mixing the above (base ingredient), 80 parts of the base ingredient was mixed with 2 parts of the hardening agent, and a test piece was prepared in the same manner as in Example 1. was prepared and subjected to a comparative test.

Comparative Example 3 (Main agent) Bisphenol type epoxy resin in parts by weight 45.0 (same as Example 1) Glass flakes 30.0 (trade name CCF-150 manufactured by Nippon Glass Textile Co., Ltd.) Anti-settling agent (
Organic bentonite) 2.0 Methyl isobutyl ketone 10
．． 0 xylol 13.0100.
0 (Curing agent) Polyamide resin (same as Example 1) 75.0 Isobutanol 25.0100.0 Main ingredient 8 of the above formulation? In contrast, a test piece was prepared in the same manner as in Example 1 by mixing a curing agent nodule, and was subjected to a comparative test.

From the above comparative test results table, it is clear that the coating obtained from the composition of the present invention has significantly improved weather resistance (resistance to discoloration and fading) and corrosion resistance compared to the coating obtained from the conventional lining composition. It is clear that the properties are also excellent.

Claims (1)

[Claims] 1. An anticorrosion coating composition comprising 100 parts by weight of epoxy resin, 10 to 150 parts by weight of glass flakes uniformly colored throughout, and the required amount of hardening agent.