JP3335932B2 - Heavy duty 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 a room temperature curing type heavy duty anticorrosion paint used for petroleum complex plants, tanks, bridges, etc., which improves water resistance and adhesion by reducing moisture permeability. is there.

[0002]

2. Description of the Related Art A heavy-duty anticorrosion paint containing a room temperature-curable amine and an epoxy resin as main components contains an inorganic filler in order to improve rust prevention, reduce moisture permeability and water absorption in an organic resin. Inorganic fillers reduce the overall moisture permeability of the coating, but have little effect on the time to reach the moisture, which causes paint-substrate destruction. As a method to lengthen the route of water arrival,
Although flaky glass flakes and the like are used, the water resistance is hardly improved. In order to improve coating film hardness and heat resistance, an inorganic filler such as silica or titanium oxide is added. The addition of the inorganic filler significantly improves the surface hardness and heat resistance. However, when such a filler is added, the effect of lowering the permeation amount is low in a room temperature cured coating film having high moisture permeability, and the coating film is peeled off with little improvement in moisture resistance and adhesion. For this reason, in a humid environment,
In order to suppress a decrease in adhesion, a method of physically bonding the surfaces by plasting or thermal spraying, or a method of chemically bonding them with a surface treating agent is used.
However, since moisture permeability has not been fundamentally improved,
A reduction in adhesion due to moisture absorption is unavoidable, and there are restrictions on the use environment of room temperature-curable coatings.

[0003]

DISCLOSURE OF THE INVENTION The present invention suppresses moisture permeation and moisture absorption in a high humidity environment, which is a problem of amine-curable heavy-duty anticorrosion coating compositions, and has a high surface height and high heat resistance. An object of the present invention is to provide a coating composition for forming a film having excellent water resistance and adhesion, and a surface treating agent for effectively fixing the coating to a base substrate.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, the coating composition comprising an epoxy resin, an amine for curing the epoxy resin, and a filler further contains a specific silicon. It has been found that the alkoxide of the present invention is hydrolyzed and condensed with the hydroxyl group of the epoxy resin or self-condensed, thereby increasing the crosslink density of the paint and consequently improving the water permeability. This resulted in an anticorrosion coating composition. In addition, when applying this paint, the silane coupling agent having a functional group having both a metal coordination ability and a curing function of an epoxy resin in advance with respect to the metal-coated surface, exhibits a metal coordination ability, and exhibits hydrophobicity. It has also been found that by performing a surface treatment with a mixture with a silane coupling agent having the functional group shown, the adhesion of the coating material and the durability of the coating film can be improved.

That is, the present invention provides: (1) A heavy-duty anticorrosion coating composition comprising a silicon alkoxide represented by the general formula (A), an epoxy resin, an amine for curing the epoxy resin, and a filler, which is represented by the general formula: A metal material coated on a metal surface treated with a mixture of an organosilicon compound having a structure shown in (B) and (C). R ¹ _n Si (OR) _4-nm (OR ′) _m (A) (wherein R ¹ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, an imidazole group-containing organic group, and R and R ′ Is 1 carbon
And n represents 0 or 1, m represents 0,
1, 2, 3, or 4. ) R ² Si (OR ³ ) ₃ (B) R ⁴ Si (OR ³ ) ₃ (C) (wherein R ² is an organic group containing a carbonyl group, R ³ is a lower alkyl group, and R ⁴ contains an amino group) (2) A metal surface is treated with a mixture of an organosilicon compound having a structure represented by formulas (B) and (C), and then an alkoxide of silicon represented by formula (A); Epoxy resin,
A method for coating a heavy duty anticorrosion paint composition, which comprises coating with a heavy duty anticorrosion paint composition containing an amine for curing the epoxy resin and a filler. R ¹ _n Si (OR) _4-nm (OR ′) _m (A) (wherein R ¹ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, an imidazole group-containing organic group, and R and R ′ Is 1 carbon
And n represents 0 or 1, m represents 0,
1, 2, 3, or 4. ) R ² Si (OR ³ ) ₃ (B) R ⁴ Si (OR ³ ) ₃ (C) (wherein R ² is an organic group containing a carbonyl group, R ³ is a lower alkyl group, and R ⁴ contains an amino group) (3) The heavy duty anticorrosion paint composition according to the above (2), wherein the mixing ratio of the organic silicon compound having the structure represented by the general formulas (B) and (C) is 1: 9 to 9: 1. Method of coating objects. R ² Si (OR ³ ) ₃ (B) R ⁴ Si (OR ³ ) ₃ (C) (wherein R ² is an organic group containing a carbonyl group, R ³ is a lower alkyl group, and R ⁴ contains an amino group. Represents an organic group.)

[0006]

DETAILED DESCRIPTION OF THE INVENTION The general formula (A) used in the present invention
Wherein R ¹ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group or an imidazole group-containing organic group, and R and R ′ each represent an alkyl group having 1 to 6 carbon atoms;
n is 0 or 1, m is 0, 1, 2, 3 or 4. R and R 'are particularly preferably a methyl group or an ethyl group.

The organosilicon compound can be arbitrarily selected according to the desired physical properties of a film obtained by curing the composition, but the content is based on the total coating weight (solid basis, hereinafter the same). Is preferably 1 to 10% by weight. If the amount is more than this, the coating becomes brittle and the properties become insufficient.

Known epoxy resins can be used. Specific examples thereof include bifunctional epoxy resins such as bisphenol A diglycidyl ether and bisphenol F diglycidyl ether, those having an epoxy group in a polyhydric phenol such as resorcinol and pyrogallol, and glycidyl ester resins such as diglycidyl phthalate. A polyfunctional epoxy resin such as an orthocresol novolak type is exemplified. These materials may be used alone or in combination of two or more.

The amount of epoxy resin used is based on the total amount of paint.
When the content is 35 to 55% by weight, the effect of the present invention is exhibited. 3
When the content is less than 5% by weight, the function of the paint used as a binder becomes insufficient. On the other hand, when the content is 55% by weight or more, the function of the coating material is significantly reduced.

As a curing agent for curing the epoxy resin, an aliphatic polyamine such as diethylenetriamine,
Examples thereof include cyclic aliphatic amines such as diaminodicyclohexylmethane, imidazoles such as methylimidazole, and modified amines such as maleimideamines, polyaminoesters, and epoxide reactants of polyamines. May be used.
Further, a tertiary amine such as tris (dimethylaminomethyl) phenol may be used to accelerate the curing reaction. Most preferably, the amount of the aliphatic amine used corresponds to the epoxy functional group of the epoxy resin used. If the value deviates from this value, the characteristics of the cured resin material deteriorate.

The type of the filler is not limited, and oxides such as silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, and basic magnesium carbonate are used. Hydroxide, barium sulfate, sulfate such as gypsum, calcium silicate, talc, glass beads, sericite activated clay,
Any material may be used as long as it has a function of increasing the hardness of the coating film, such as silicates such as bentonite, nitrides such as aluminum nitride and silicon nitride, and various metals.

The amount of the inorganic pigment used here is from 40 to
Desirably, it is 60% by weight. If it is less than 40% by weight, the surface hardness is low, and if it is more than 60% by weight, the surface hardness is too high.

[0013] To adjust the viscosity of such a heavy duty anticorrosive paint, alcohol solvents such as isopropyl alcohol, aromatic solvents such as toluene, cellsolve solvents such as ethoxyethanol, ketone solvents such as methyl ethyl ketone or ethyl acetate. It is necessary to use volatile organic solvents such as esters.

Next, a surface treatment agent for improving the adhesion of the metal surface to which the heavy anticorrosion paint is applied will be described.

In the general formula (B), R ² is CH ₃ COCH ₂ CO
Dicarbonyl such as OC ₃ H ₆ — and CH ₃ COCHR ⁵ COO
C ₃ H ₆ — (wherein R ⁵ is COR ⁶ .X, where R ⁶ represents an alkylene group having 1 to 15 carbon atoms, and X represents H or the aforementioned Si (OR ³ ) ₃ ), CH ₃ COCH (COC
H ₃ ) An organic silicon compound having a tricarbonyl structure such as COC ₁₀ H ₂₀ —.

In the general formula (C), R ⁴ is H ₂ NCH ₂ CH ₂ CH
_2- or H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ C
An organic silicon compound having an aminoethyl group such as H ₂ —.

The mixing ratio of the general formulas (B) and (C) is desirably 1: 9 to 9: 1 by weight. More preferably, it is 3: 7 to 7: 3. In this organosilicon compound, the mixture can be applied as it is,
Generally, it is desirable to use the solvent used for adjusting the viscosity of the paint. When diluting with a solvent, the concentration of the mixture of the organosilicon compounds (B) and (C) is preferably 1 to 10% by weight based on the total weight.

The use of the anticorrosion paint of the present invention is not particularly limited, and is effective for metal materials such as bridges and petroleum complexes.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 Bisphenol A type epoxy resin (Epicoat 828:
To 30 parts of Yuka Shell and 11 parts of diglycidyl phthalate, 47 parts of silica, 2.3 parts of 2-methyl-4-ethylimidazole, and 3.7 parts of diaminodicyclohexylmethane were added, and 2 parts of MEK were added to adjust the viscosity. MIBK
After mixing 4 parts, 5 parts of tetramethoxysilane of general formula (A) where n and m are 0 were added and sufficiently stirred to obtain a heavy-duty anticorrosion paint of this example. Next, a 150 μm-thick coating film was prepared using this coating material and used as a test piece.

[0021] Example 2 Example tetramethoxysilane imidazole group-containing imidazole silane used in 1 (IS-1000: Japan Energy Ltd., is R ¹ in formula (A)

[0022]

Embedded image

A composition was prepared in which R and R ′ were methyl groups, n was 1 and m was 0, and a 150 μm thick test piece was prepared in the same manner as in Example 1.

Comparative Example 1 A composition excluding tetramethoxysilane was prepared from the composition of Example 1, and a 150 μm thick test piece was prepared in the same manner as in Example 1.

(Evaluation) The moisture permeability of each sample was determined by JI
It was measured by the method described in SZ0208 (measurement conditions: temperature 40 ° C., relative humidity 90%).

[0026] From Table 1 breathable Evaluation Results Example 1 Example 2 Comparative Example 1 The moisture permeability ^{(g / m 2 / 24hr)} 0.8 2.2 7.5 Table 1, coating films of Examples to Comparative Example It was found that the moisture permeability was significantly lower than that.

Example 3 Heavy anticorrosion paint (Ceraprotec C2033: manufactured by Nikkei Co., Ltd., 40 parts of epoxy resin, 6 parts of curing agent, filler 4)
(7 parts, solvent 7 parts), and 5 parts by weight of tetramethoxysilane with respect to the paint weight. Next, this paint was applied to a carbon steel (S45C) having a thickness of 3 mm with a brush to a thickness of 150 μm and dried at room temperature for 1 week to prepare a test piece.

Example 4 In the general formula (B), R ² is CH ₃ COCHR ⁵ COOC ₃ H
₆ (wherein R ⁵ is COR ⁶ .X, R ⁶ represents an alkyl group having 10 carbon atoms, and X represents Si (OMe) ₃ ) and R in the general formula (C). ⁴ is H ₂ NCH ₂ CH ₂
An organic silicon compound (LS-3750: manufactured by Shin-Etsu Chemical Co., Ltd.) which is NH ₂ CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ in a weight ratio of 1:
1 and treated with a solution diluted to 1% by weight with isopropyl alcohol. Using a 3 mm-thick carbon steel (S45C) dried at room temperature for 2 hours, the heavy-duty anticorrosion paint shown in Example 3 was applied, and the test piece was used. Produced.

Example 5 A test piece was prepared by using the metal plate used in Example 4 in place of tetraethoxysilane in place of imidazole silane (IS-1000: manufactured by Japan Energy) in the heavy duty anticorrosion paint shown in Example 3. did.

Comparative Example 2 The polymer anticorrosive paint shown in Example 3 was prepared by using carbon steel (S45
C) was applied with a brush to a thickness of 150 μm and dried at room temperature for one week to prepare a test piece.

(Test / Evaluation)
Using a lining tester described in TM-01-74, a moisture absorption test (moisture absorption condition: contacting the paint surface with warm water heated to 95 ° C, cooling the back surface to 20 ° C, for 2 days) was performed. The appearance of the coating film was visually inspected for the presence of swelling, and was evaluated as ○ when no swelling was observed, Δ when small swelling occurred, and X when large swelling occurred. Further, in accordance with JIS K 5400, the adhesion strength of the coating film was measured and the fracture surface was observed with a coating film adhesion tester (adhesion tester).

Table 2 Evaluation of Adhesion of Coating Film Example 3 Example 4 Example 5 Comparative Example 2 Strength (MPa) 3.5 4.5 5.0 2.5 2.5 Failure Mode Interface Coagulation of Coating Coagulation of Coating Interface Coating Film appearance ○ ○ △ × Note) Paint agglomeration: destruction inside the paint From Table 2, it can be seen that adding an additive to the heavy-duty anticorrosive paint makes it difficult for blistering to occur, and that the mode of destruction by treating the surface treatment agent. Was found to change.

[0033]

According to the present invention, by adding an alkoxide of silicon to an amine-curable epoxy resin containing an inorganic filler such as silica or titanium oxide, the permeability is remarkably improved, and the adhesion of the coating film when absorbing moisture is improved. It is to improve. Further, the adhesion of this material is effectively exhibited by previously treating a metal surface with a mixture of a silicon compound having an amino group and a silicon compound having a carbonyl group.

────────────────────────────────────────────────── ─── of the front page continued (51) Int.Cl. ⁷ identification mark FI // C08G 59/50 C08G 59/50 (58 ) investigated the field (Int.Cl. ^7, DB name) C09D 5/08 C09D 163 / 00-163/10 B05D 7/14 C23C 22/00-22/86

Claims (3)

(57) [Claims] 1. A heavy-duty anticorrosion coating composition comprising a silicon alkoxide represented by the general formula (A), an epoxy resin, an amine for curing the epoxy resin and a filler,
A metal material coated on a metal surface treated with a mixture of an organosilicon compound having a structure represented by the general formulas (B) and (C). R ¹ _n Si (OR) _4-nm (OR ′) _m (A) (wherein R ¹ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, an imidazole group-containing organic group, and R and R ′ Is 1 carbon
And n represents 0 or 1, m represents 0,
1, 2, 3, or 4. ) R ² Si (OR ³ ) ₃ (B) R ⁴ Si (OR ³ ) ₃ (C) (wherein R ² is an organic group containing a carbonyl group, R ³ is a lower alkyl group, and R ⁴ contains an amino group) Represents an organic group.) 2. A metal surface is treated with a mixture of an organosilicon compound having a structure represented by formulas (B) and (C), and thereafter, an alkoxide of silicon represented by formula (A), an epoxy resin, A method of coating a heavy-duty anticorrosion paint composition, which is coated with a heavy-duty anticorrosion paint composition containing an amine for curing a resin and a filler. R ¹ _n Si (OR) _4-nm (OR ′) _m (A) (wherein R ¹ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, an imidazole group-containing organic group, and R and R ′ Is 1 carbon
And n represents 0 or 1, m represents 0,
1, 2, 3, or 4. ) R ² Si (OR ³ ) ₃ (B) R ⁴ Si (OR ³ ) ₃ (C) (wherein R ² is an organic group containing a carbonyl group, R ³ is a lower alkyl group, and R ⁴ contains an amino group) Represents an organic group.) 3. The coating method according to claim 2, wherein the mixing ratio of the organosilicon compound having the structure represented by the general formulas (B) and (C) is 1: 9 to 9: 1. R ² Si (OR ³ ) ³ (B) R ⁴ Si (OR ³ ) ³ (C) (wherein R ² is an organic group containing a carbonyl group, R ³ is a lower alkyl group, and R ⁴ contains an amino group. Represents an organic group.)