JPH09302276A - Anticorrosive coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an anticorrosive coating composition which can form coating films being excellent in anticorrosiveness, water resistance and adhesion and having a color lighter as compared with a coating film of an anticorrosive coating composition containing tar and retains compatibility with a curable resin by using a specified cracking residuum instead of tar. SOLUTION: This composition comprises an epoxy resin, an amine curing agent and a cracking residuum having a softening point of 50-150 deg.C and used in an amount of 20-500 pts.wt. per 100 pts.wt. (in terms of solid) curable resin. The amine curing agent is desirably an aromatic polyamine, especially an alkylated phenolic polyamine prepared by modifying a polyamine with phenol on an alkylphenol and formalin. The cracking residuum is a residuum produced as a by-product in a process for thermally cracking petroleum naphtha and containing polynuclear aromatic compounds as the principal components, desirably a product obtained by removing low-molecular compounds from the residuum by distillation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tar-free anticorrosive coating composition which is particularly useful for coating the interior of ships such as ballast tanks.

[0002]

2. Description of the Related Art Tall epoxy paints have been used as anticorrosion paints for ships and steel structures. The paint is excellent in corrosion resistance, water resistance, chemical resistance, etc., but since it contains tar, it has benzpyrene (carcinogenic substance) contained in the tar, which causes safety and health problems. Not only was there a concern, it was difficult to maintain because it was black, and there was a problem that work was dangerous because it became dark in a closed place.

In recent years, non-tall paints using petroleum-based resins instead of tars have been developed.
There is a problem with the compatibility of the cured resin consisting of the epoxy resin and the amine curing agent with the petroleum-based resin, and particularly high corrosion resistance,
It was not enough to apply it in the ballast tank of a ship that requires water resistance.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that an epoxy resin and an amine curing agent are formed by using a specific cracked residual oil instead of tar. An anti-corrosion coating composition capable of forming a light-colored coating film as compared with a tar, while maintaining compatibility with a cured resin, having no safety and health problems, excellent in corrosion resistance, water resistance, and adhesion The present invention was found to be achieved.

That is, the present invention relates to (A) epoxy resin,
(B) amine curing agent, and (C) softening point 50-150
The present invention provides an anticorrosion coating composition comprising a decomposed residual oil (° C) of 20 to 500 parts by weight with respect to 100 parts by weight of a cured resin solid content.

Hereinafter, the present invention will be described in detail.

Epoxy resin (A) used in the present invention
Is one having at least two epoxy groups in one molecule, and an epoxy equivalent of 150 to 600, preferably 150 to 300 is suitable. Examples of such epoxy resin include bisphenol type epoxy resin, aliphatic epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, cresol type epoxy resin, dimer acid modified epoxy resin. Examples include conventionally known resins such as resins, and these may be used alone or in combination of two or more.

As the amine curing agent (B) used in the present invention, conventionally known curing agents for epoxy resins, for example, aliphatic polyamines such as metaxylenediamine, isophoronediamine, diethylenetriamine, triethylenetetramine and diaminodiphenylmethane, Examples thereof include alicyclic polyamines, aromatic polyamines; epoxy resin adducts of the polyamines, polyamide amines, polyamide resins, and the like, and these can be used alone or in combination of two or more. Among these, aromatic polyamines are preferable from the viewpoint of compatibility with cracked residual oil (C) and reactivity with epoxy resin, and particularly polyamines are preferably phenol or alkylphenol (for example, 3-amine). n-pentadinylphenol, etc.)
And alkylated phenolic polyamines modified with formalin are preferred.

The mixing ratio of the above components (A) and (B) is
Although it is appropriately selected depending on the species used, it is usual that the equivalent ratio of [active hydrogen equivalent in (B) / epoxy equivalent in (A)] is in the range of 0.5 to 1.0. Appropriate.

The cracked residual oil (C) used in the present invention is a residue produced as a by-product when obtaining various cracked oil fractions produced in the thermal cracking process of petroleum naphtha, and is mainly composed of polynuclear aromatic compounds. It contains a large amount of impurities and has a relatively broad molecular weight distribution. Particularly, it is preferable to remove from the residue by distillation a low-molecular component that easily bleeds on the surface of the coating film. Further, the cracked residual oil (C) does not contain a polar compound (such as a sulfur compound) in the impurities as compared with tar, and the aromatic ring and the naphthene ring are appropriately mixed in the polynuclear body. Therefore, it is excellent in water resistance, has a low content of benzpyrene (carcinogenic substance), and has a brownish color as compared with tar.

As the cracked residual oil (C), one having a softening point of 50 to 150 ° C., preferably 80 to 100 ° C. can be used. If the softening point of the cracked residual oil (C) is less than 50 ° C, the water resistance of the coating film may be deteriorated and the components may bleed on the surface of the coating film to leave tackiness, while if it exceeds 150 ° C. It is not preferable because the viscosity of the paint increases and the workability decreases.

The composition of the present invention contains the cracked residual oil (C) in an amount of 20 to 500 parts by weight, preferably 50 to 300 parts by weight, based on 100 parts by weight of the solid content of the cured resin. If the content is less than 20 parts by weight, sufficient water resistance cannot be obtained, while if it exceeds 500 parts by weight, the coating film becomes brittle and good physical properties cannot be obtained, which is not preferable.

In the composition of the present invention, the cracked residual oil (C) is
If necessary, a petroleum resin having a softening point of 50 to 150 ° C. may be used together within a range that does not adversely affect the compatibility with the cured resin component. Examples of the petroleum resin include an aromatic petroleum resin obtained by polymerizing a C ₉ fraction such as a styrene derivative and indene from heavy oil produced by the decomposition of petroleum naphtha, and the C ₅ fraction and the C ₉ fraction as described above. Polymerized copolymer petroleum resin, aliphatic petroleum resin in which conjugated diene of C ₅ fraction such as cyclopentadiene and 1,3-pentadiene is partially cyclopolymerized, resin obtained by hydrogenating aromatic petroleum resin, Examples thereof include alicyclic petroleum resins obtained by polymerizing dicyclopentadiene.

In the composition of the present invention, from the viewpoint of imparting flexibility, other liquid modifiers such as xylene resin and toluene resin; reaction diluents such as butylglycidyl ether and other epoxy compounds; phenol; A non-reactive diluent such as a modified polycondensate may be added in an amount of 50 parts by weight or less with respect to 100 parts by weight of the solid content of the cured resin. Of these, aromatic compounds are preferably used from the viewpoint of maintaining water resistance.

In the composition of the present invention, if necessary, pigments such as extender pigments, rust preventive pigments and coloring pigments; reactive diluents; organic solvents, anti-settling agents, anti-sagging agents, wetting agents,
Ordinary paint additives such as a reaction accelerator, an adhesion promoter, and a dehydrating agent may be appropriately contained.

The composition of the present invention is a two-pack type coating composition comprising an epoxy resin-based main agent and an amine-based curing agent, and is usually applied on a primary anticorrosive coating film such as a zinc primer. As a coating method of the above-mentioned paint, conventionally known methods such as air spray, airless spray, brush coating, roller and the like can be adopted, and the above-mentioned paint can be applied so as to have a dry film thickness of 150 to 300 µm. .

[0017]

EXAMPLES The present invention will be described in more detail with reference to examples. “Parts” and “%” are “parts by weight” respectively.
And "% by weight".

Example 1 In a 1-liter container, 100 parts of epoxy resin (Note 1), 70 parts of titanium white, 100 parts of talc, cracked residual oil (Note 2) 50
Parts, xylene resin (Note 3) 10 parts, anti-sagging agent (Note 4)
Add 10 parts and 10 parts of xylene and mix with a disperser.
Stir and disperse to make the main agent, and add amine curing agent (Note 5)
70 parts was added immediately before coating and mixed and stirred to obtain an anticorrosive paint.

(Note 1) "Epon # 828": Epoxy equivalent 190, manufactured by Yuka Shell Epoxy Co., Ltd. (Note 2) "CR-Z": cracked residual oil, softening point 80 ° C, manufactured by Maruzen Petrochemical Co. (Note 3) ) "Nicanol L": Mitsubishi Gas Chemical Co., Ltd. (Note 4) "Disparlon A630-20XN": Polyamide wax, Kusumoto Kasei Co., Ltd. (Note 5) "Sunmide CX102": 3-n-penta aliphatic polyamine Alkylated phenolic polyamine modified with dinylphenol and formalin, active hydrogen equivalent 130, Sanwa Chemical Co., Ltd. Examples 2 to 6 and Comparative Examples 1 to 4 In Example 1, the composition and formulation shown in Table 1 Each anticorrosion paint was obtained by the same operation as in Example 1 except that the amount was changed. (Note 6) to (Note 8) in Table 1 are as follows. As Comparative Example 4, "Epocal 6000PS" (Tales epoxy resin paint manufactured by Kansai Paint Co., Ltd.) was used. Table 1 shows the solid content.

(Note 6) "Epon # 1001": Epoxy equivalent 475, manufactured by Yuka Shell Epoxy Co., Ltd. (Note 7) "Neopolymer-100": Aromatic petroleum resin,
Softening point 100 ° C, Nippon Petrochemical Co., Ltd. (Note 8) "Daito Clar X778C": Mannich modified metaxylylenediamine, active hydrogen equivalent 70, performance test by Daito Sangyo Co., Ltd. Performance test It was submitted to the test. The results are shown in Table 1. (* 1) Flexibility Polished mild steel plate (150 x 70 x
0.8 mm) was coated with an airless sprayer to a thickness of about 250 μm (dry film thickness) and dried in an atmosphere of 20 ° C. × 65% RH for 7 days to prepare each test coated plate. The coated plate was bent at 90 ° with the coated surface facing outward in an atmosphere of 20 ° C, and cracks in the coating film at the bent portion were visually evaluated (○: no crack, Δ: slightly cracked, ×: considerably cracked. ).

(* 2) Temperature Difference Water Resistance Shot Blast Steel Sheet (300 × 100 × 3.2 mm)
(Test plate I), and "SD zinc 1000" on the steel plate
Each of the above-obtained test plates (test plate II) coated with (Kisai Paint Co., Ltd., silicate zinc primer) to a thickness of about 25 μm (dry film thickness) and dried for one day. Each anticorrosive paint was applied by an airless spray to a thickness of about 250 μm (dry film thickness) and dried in an atmosphere of 20 ° C. × 65% RH for 7 days to obtain each test coated plate.

The coated surface of this test coated plate was immersed in warm water of 40 ° C,
After being immersed in a dipping tank in which the back surface is in contact with water at 20 ° C. for 14 days, the coated surface state was visually evaluated (◯: no abnormality,
(Triangle: Occurrence of blisters and rust is slightly observed, x: Significant blisters and rust)

(* 3) Seawater resistance Each test coated plate obtained in the same manner as in (* 2) above was visually evaluated for coating surface condition after immersion in seawater at 50 ° C. for 3 months (◯: no abnormality) , △: A little blistering was observed,
X: significant blistering occurs).

[0024]

EFFECTS OF THE INVENTION The anticorrosion coating composition of the present invention has good compatibility with a cured resin composed of an epoxy resin and an amine curing agent by using a specific amount of cracked residual oil instead of tar, and thus has safety and health. It is excellent in corrosion resistance, water resistance, and adhesiveness without any problems, and can form a lighter color coating film than tar, and is very useful as an anticorrosion paint for ships and steel structures.

[0025]

[Table 1]

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Claims (3)

[Claims] 1. An (A) epoxy resin, (B) an amine curing agent, and (C) a cracked residual oil having a softening point of 50 to 150 ° C., wherein the cracked residual oil (C) is 100 parts by weight of a solid content of a cured resin. 20 to 500 parts by weight of the anticorrosion coating composition. 2. The composition according to claim 1, wherein the amine curing agent (B) is an alkylated phenolic polyamine. 3. The cracked residual oil (C) is a residue produced as a by-product in the thermal cracking process of petroleum naphtha, which contains a polynuclear aromatic compound as a main component and has a low molecular weight component removed by distillation from the residue. The composition according to claim 1 or 2.