JPWO2019078097A1 - Anticorrosion paint, coating film and laminate - Google Patents

Abstract

(EN) A rust preventive paint capable of sufficiently preventing corrosion of a specific metal and corrosion of a dissimilar metal joint portion and forming a coating film excellent in transparency, antifouling property and adhesion. A rust preventive paint comprising a fluorine-containing copolymer containing a fluorine-containing olefin unit and a vinyl alcohol unit, wherein the fluorine-containing copolymer has characteristics (a) to (c). Characteristic (a): Water vapor permeability per 100 μm is 25 g/m 2 ·day or less Characteristic (b): Oxygen permeability coefficient is 2.0E-13 cc·cm/cm 2 ·sec·cmHg or less Characteristic (c): Water absorption rate is 10 Mass% or less

Description

The present invention relates to an anticorrosive paint, a coating film and a laminate.

Conventionally, the following paints are known as paints containing a fluorine-containing copolymer.

［式（１）中、ＸおよびＹは、それぞれ独立に、Ｈ、Ｆ、ＣＦ_３またはＣｌである。］Patent Document 1 discloses that a fluorine-containing copolymer (A) and a pigment (B) are contained, and the fluorine-containing copolymer (A) is a unit represented by the following formula (1) A unit represented by (2), the number average molecular weight of the fluorocopolymer (A) is 10,000 to 100,000, and the content of the pigment (B) is A coating composition characterized by being 20 to 200 parts by mass with respect to 100 parts by mass of the fluorocopolymer (A) is described.

[In the formula (1), X and Y are each independently H, F, CF ₃ or Cl. ]

Patent Document 2 discloses an aqueous surface treatment agent containing water, which is used for forming an insulating coating on the surface of an electromagnetic steel sheet, and is a fluoroolefin-based unit, vinyl ether, allyl ether or vinyl carboxylate, A unit based on the monomer A having an alicyclic alkyl group, and a vinyl ether, an allyl ether or a vinyl carboxylate, which has at least one crosslinkable group selected from a hydroxyl group, a carboxy group and an amino group. Described is a water-based surface treatment agent comprising a fluoropolymer having a unit based on the body B, a cross-linking agent, and a metal salt.

International Publication No. 2015/137284 International Publication No. 2016/171104

However, conventional paints have not been sufficiently effective in preventing corrosion of specific metals and corrosion of joints of dissimilar metals.

In view of the above situation, the present invention is capable of sufficiently preventing corrosion of specific metals and corrosion of dissimilar metal joints, and can form a coating film excellent in transparency, stain resistance and adhesion. The purpose is to provide paints.

The present invention also aims to provide a coating film which is capable of sufficiently preventing corrosion of a specific metal and also corrosion of a dissimilar metal joint portion, and which is also excellent in transparency, antifouling property and adhesion. To do.

The present invention is also capable of sufficiently corroding the metal base material or the dissimilar metal joint portion, and fully exhibiting the aesthetic appearance of the metal base material or the dissimilar metal joint portion due to the high transparency of the coating film, the antifouling property and the adhesiveness. It is also intended to provide an excellent laminate.

The present inventors, as a result of diligent study of means for solving the above problems, including a fluorine-containing copolymer containing a specific monomer unit, a specific water vapor permeability, a specific oxygen permeability coefficient and a specific By coating a metal base material or a dissimilar metal joint with a paint that gives a coating film having a water absorption rate, corrosion of the metal or dissimilar metal joint can be sufficiently prevented, and transparency, antifouling property and adhesion can be obtained. Further, they have found that an excellent coating film can be formed, and have completed the present invention.

That is, the present invention relates to a rust preventive paint comprising a fluorinated copolymer containing a fluorinated olefin unit and a vinyl alcohol unit, wherein the fluorinated copolymer has characteristics (a) to (c). is there.
Characteristic (a): Water vapor permeability per 100 μm is 25 g/m ² ·day or less Characteristic (b): Oxygen permeability coefficient is 2.0E-13 cc·cm/cm ² ·sec·cmHg or less Characteristic (c): Water absorption rate Is 10 mass% or less

The above-mentioned fluorine-containing copolymer preferably has a converted haze value per 30 μm of 3.0 or less.

The hydroxyl value of the fluorine-containing copolymer is preferably 400 mgKOH/g or more.

The rust-preventive coating material of the present invention is preferably for a dissimilar metal joint.
The dissimilar metal joint is preferably a dissimilar metal joint of an electric wire or a pipe.
The dissimilar metals are aluminum or aluminum alloy and copper, aluminum or aluminum alloy and iron, aluminum or aluminum alloy and zinc, aluminum or aluminum alloy and nickel, aluminum or aluminum alloy and tin, copper and iron, copper and zinc, copper and It is preferably nickel or copper and tin.

The rust-preventive paint of the present invention is preferably for steel plates, cast iron, high-temperature and high-pressure cast steel, or aluminum-zinc alloy-plated steel plates.

The above-mentioned anticorrosive paint may further contain a curing agent.

It is preferable that the fluorine-containing copolymer has solubility in an alcohol solvent.

It is preferable that the above-mentioned anticorrosive paint further contains a solvent.

The present invention is also a coating film characterized by being formed from the above-mentioned rust preventive paint.

The present invention is also a laminate including a metal substrate and the above-mentioned coating film.

INDUSTRIAL APPLICABILITY The rust-preventive coating composition of the present invention can sufficiently prevent corrosion of a metal and a joint between dissimilar metals and can form a coating film excellent in transparency, antifouling property and adhesion.

The coating film of the present invention can sufficiently prevent corrosion of a metal and a dissimilar metal joint, and is also excellent in transparency, antifouling property and adhesion.

The laminate of the present invention is less likely to corrode the metal base material and the dissimilar metal joint portion, and can fully exhibit the aesthetic appearance of the metal base material and the dissimilar metal joint portion due to the high transparency of the coating film. Also excellent in sex. Particularly, when the metal is a steel plate, cast iron, cast steel for high temperature and high pressure, or aluminum-zinc alloy-plated steel plate, excellent rust prevention is exhibited.

It is a schematic diagram which shows the external appearance evaluation method of a dissimilar metal joining part. It is a schematic diagram of an electric wire which has a coating film formed from a rust preventive coating on a dissimilar metal joint. It is a schematic diagram of piping which has a coating film formed from a rust preventive paint on a dissimilar metal joint.

Hereinafter, the present invention will be specifically described.

The rust preventive coating composition of the present invention is characterized in that it contains a fluorine-containing copolymer, and the fluorine-containing copolymer has the characteristics (a) to (c).
Characteristic (a): Water vapor permeability per 100 μm is 25 g/m ² ·day or less Characteristic (b): Oxygen permeability coefficient is 2.0E-13 cc·cm/cm ² ·sec·cmHg or less Characteristic (c): Water absorption rate Is 10 mass% or less

(Method of preparing sample (coating film, film, etc.))
Samples for measuring the water vapor permeability, the oxygen permeability coefficient, and the water absorption are prepared by the following methods.
Dissolve the fluorinated copolymer in dimethylacetamide (DMAC) or isopropyl alcohol (IPA) solvent so as to be 15% by mass, form a film on a polypropylene plate using a doctor blade of 10 mil, and then from room temperature for 30 minutes After air-drying for 8 hours, it was dried at 120° C. when using DMAC as a solvent and at 60° C. when using IPA at a temperature of 12 hours with a hot air dryer, and then peeled from a polypropylene plate to form a film. To do.
In the case of coating film evaluation, a coated plate is prepared by similarly forming a film on a glass plate or an aluminum plate and drying it. As the polypropylene plate, it is preferable to use a polypropylene plate having high releasability.
(Method of measuring film thickness)
The value of the film thickness is necessary to convert the water vapor permeability into a value per 100 μm, to calculate the oxygen permeability coefficient, and to calculate the converted haze value. The method of measuring the film thickness is not particularly limited, but it can be measured using a general micrometer or film thickness meter. In this specification, the film thickness is measured by changing the place and measuring at 5 places.

(Measurement method of water vapor permeability)
The water vapor permeability is measured according to the cup method (JIS Z0208-1976), condition B (temperature 40±0.5° C., relative humidity 90±2%). When the measured value is Q (g/m ² ·day) and the film thickness value is T (μm), the water vapor permeability Q _T per 100 μm can be calculated by the following formula.
Q _T =Q×T/100

(Measuring method of oxygen permeability coefficient)
The oxygen permeability coefficient is measured according to JIS K 7126-1. Specifically, the measurement can be performed according to JIS K 7126-1 using a differential pressure type gas/vapor permeability measuring device. According to the differential pressure method according to JIS K 7126-1, the differential pressure is 1 atm, the test temperature is 23±2° C., the drying condition is measured with a gas chromatograph (heat conductivity detector). As the differential pressure type gas/vapor permeability measuring device, for example, GTR Tech Co., Ltd. GTR-30XAD2, Yanaco Technical Science Co., Ltd. G2700T/F can be used.

(Measurement method of water absorption)
The water absorption rate is measured by the following method.
The film piece was immersed in water at room temperature of 23° C., the weight change was measured for several days, and the water absorption rate (R) was calculated by the following formula when the water absorption was saturated compared to the previous day.
R(%)=(saturated water absorption weight−initial weight)/initial weight×100

Water vapor permeability per above 100μm is less ^{25g / m 2 · day, 22g} / m 2 · day or less are preferred, 20 g ^/ m or less, more preferably 2 · day, although a lower limit is not particularly limited, 0.1 g It may be /m ² ·day.

The oxygen permeability coefficient is preferably 2.0E-13 cc·cm/cm ² ·sec·cmHg or less, more preferably 1.5E-13 cc·cm/cm ² ·sec·cmHg or less, and the lower limit is not particularly limited. , 1.0E-15 cc·cm/cm ² ·sec·cmHg.

The water absorption is preferably 10% by mass or less, more preferably 8% by mass or less, and the lower limit is not particularly limited, but may be 0.1% by mass.

The above-mentioned fluorine-containing copolymer preferably has a converted haze value per 30 μm of 3.0 or less. The converted haze value is more preferably 2.5 or less.
The converted haze value is measured according to JIS K7136 using a haze meter. As the haze meter, a haze meter (HAZE MATER NDH7000SP manufactured by Nippon Denshoku Co., Ltd.) can be used.
When the haze value measured using a haze meter is H and the film thickness value is T (μm), the converted haze value H _T per 30 μm can be calculated by the following formula.
H _T =H×30/T
The sample for measuring the above-mentioned converted haze value is prepared by the same method as the sample for measuring the water vapor permeability, the oxygen permeability coefficient and the water absorption.

The fluorine-containing copolymer, fluorine-containing olefin units and vinyl alcohol units _{(-CH 2 -CH (OH) -} ) having an.

The above-mentioned fluorine-containing olefin unit represents a polymerized unit based on a fluorine-containing olefin. The fluorinated olefin is a monomer having a fluorine atom.

Examples of the above-mentioned fluorine-containing olefin include tetrafluoroethylene [TFE], vinylidene fluoride [VdF], chlorotrifluoroethylene [CTFE], vinyl fluoride, hexafluoropropylene [HFP], hexafluoroisobutene, and CH ₂ =CZ. ¹ _{(CF 2)} (wherein, ^{Z 1} is H, F or Cl, ^{Z 2} is H, F or Cl, n1 is an integer of from 1 to 10.) n1 ^{Z 2} monomer represented by, CF ₂ =CF-ORf ¹ (wherein Rf ¹ represents a perfluoroalkyl group having 1 to 8 carbon atoms) and perfluoro(alkyl vinyl ether) [PAVE], and CF ₂ =CF-OCH ₂ It is preferable that at least one fluorine-containing olefin selected from the group consisting of alkyl perfluorovinyl ether derivatives represented by —Rf ² (wherein Rf ² is a perfluoroalkyl group having 1 to 5 carbon atoms). ..

Examples of the monomer represented by ^{_{CH 2 = CZ 1 (CF 2}} ) n1 Z 2, CH 2 = CFCF 3, CH 2 = CHCF 3, CH 2 = CFCHF 2, CH 2 = CClCF 3 , and the like.

Examples of the PAVE include perfluoro(methyl vinyl ether) [PMVE], perfluoro(ethyl vinyl ether) [PEVE], perfluoro(propyl vinyl ether) [PPVE], perfluoro(butyl vinyl ether), and the like. , PEVE or PPVE are more preferred.

As the above-mentioned alkyl perfluoro vinyl ether derivative, one in which Rf ² is a perfluoroalkyl group having 1 to 3 carbon atoms is preferable, and CF ₂ ═CF—OCH ₂ —CF ₂ CF ₃ is more preferable.

As the fluorine-containing olefin, at least one selected from the group consisting of TFE, CTFE and HFP is more preferable, and TFE is further preferable.

The water vapor permeability, the oxygen permeability coefficient, and the water absorption rate can be adjusted mainly by adjusting the contents of the fluorinated olefin unit and the vinyl alcohol unit. In the fluorine-containing copolymer, it is preferable that the fluorine-containing olefin unit is 15 to 45 mol% and the vinyl alcohol unit is 55 to 85 mol %. The content of each monomer unit is more preferably 20 to 40 mol% for the fluorinated olefin unit and 60 to 80 mol% for the vinyl alcohol unit.

The above-mentioned fluorine-containing copolymer preferably has an alternating rate of fluorine-containing olefin units and vinyl alcohol units of 50% or less. When the alternating rate is in such a range, the effect that the coating film has high transparency and the solvent solubility is high can be obtained. It is more preferably 45% or less, and particularly preferably 35% or less. Further, it is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more. If the alternating rate is too low, the heat resistance may decrease, which is not preferable.

The alternating rate of the fluorinated olefin unit and the vinyl alcohol unit is measured with the fluorinated copolymer before hydroxylation. The fluorine-containing copolymer before hydroxylation means a polymer of a fluorine-containing olefin unit and a vinyl ester unit. The above-mentioned fluorine-containing copolymer can be synthesized by, for example, hydrolyzing a polymer of a fluorine-containing olefin unit and a vinyl ester unit. In the first place, vinyl monomers corresponding to vinyl alcohol units are chemically unstable and decompose, so it is difficult to use for polymerization. Therefore, the alternating ratio of the fluorinated olefin unit and the vinyl alcohol unit in the present invention is determined by measuring the fluorinated copolymer before hydroxylation. Using a solvent in which the above-mentioned fluorine-containing copolymer before hydroxylation is dissolved, such as deuterated acetone, ¹ H-NMR measurement of the above-mentioned fluorine-containing copolymer before hydroxylation was carried out, and the alternating ratio of three chains was calculated from the following formula. Can be calculated as
Alternation rate (%)=C/(A+B+C)×100
A: the number of Vs that are combined with two Vs such as -V-V-V- B: the number of Vs that are combined with V and T such as -V-V-T- C: -T-V- Number of Vs bonded to two Ts like T- (T: fluorine-containing olefin unit, V: vinyl alcohol unit)
The number of V units of A, B, and C is the vinyl ester unit (—CH ₂ —CH(O(C═O)R)—) of ¹ H-NMR measurement (where R is a normal alkyl group having 1 or more carbon atoms). It is calculated from the intensity ratio of H of the main chain bonded to the tertiary carbon (indicating a group).

The fluorine-containing copolymer is further represented by —CH ₂ —CH(O(C═O)R)— (wherein R represents a hydrogen atom or a hydrocarbon group having 1 to 17 carbon atoms). It may have a vinyl ester monomer unit.

The vinyl ester monomer unit is a monomer represented by —CH ₂ —CH(O(C═O)R)— (wherein R represents a hydrogen atom or a hydrocarbon group having 1 to 17 carbon atoms). Although it is a unit, as R in the above formula, an alkyl group having 1 to 11 carbon atoms is preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable. Particularly preferably, it is an alkyl group having 1 to 3 carbon atoms.

Examples of the vinyl ester monomer unit include the following vinyl ester-derived monomer units.
Vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate, vinyl isovalerate, vinyl caproate, vinyl heptylate, vinyl caprylate, vinyl pivalate, vinyl pelargonate, vinyl caprate, Vinyl laurate, vinyl myristate, vinyl pentadecylate, vinyl palmitate, vinyl margarate, vinyl stearate, vinyl octylate, Veova-9 (manufactured by Showa Shell Sekiyu KK), Veova-10 (Showa Shell Sekiyu KK )), vinyl benzoate, vinyl versatate.
Among these, a monomer unit derived from vinyl acetate, vinyl propionate, or vinyl versatate is preferable. A vinyl acetate monomer unit and a vinyl propionate monomer unit are more preferable, and a vinyl acetate monomer unit is still more preferable.

When the above-mentioned fluorine-containing copolymer has a fluorine-containing olefin unit, a vinyl alcohol unit and a vinyl ester monomer unit, the content of the vinyl ester monomer unit is relative to the total content of the fluorine-containing olefin unit and the vinyl alcohol unit. Thus, the vinyl ester monomer unit content is preferably 1 to 30 mol %, and more preferably 1 to 20 mol %.

When the above-mentioned fluorine-containing copolymer has a fluorine-containing olefin unit, a vinyl alcohol unit and a vinyl ester monomer unit, the alternation rate of the fluorine-containing olefin unit and the vinyl alcohol unit and the vinyl ester monomer unit should be 50% or less. Is preferred. When the alternating rate is in such a range, the effect that the coating film has high transparency and the solvent solubility is high can be obtained. It is more preferably 45% or less, and particularly preferably 35% or less. Further, it is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more. If the alternating rate is too low, the heat resistance may decrease, which is not preferable.

The alternating rate of the fluorinated olefin unit with the vinyl alcohol unit and the vinyl ester monomer unit is the same as the alternating rate of the fluorinated olefin unit with the vinyl alcohol unit, and the fluorine-containing copolymer before hydroxylation is used. That is, when the structural unit before hydroxylation is a vinyl ester monomer unit, ¹ H-NMR measurement of the fluorinated copolymer is carried out using a solvent in which the fluorinated copolymer such as heavy acetone is dissolved, and the following formula It can be calculated as an alternating rate of three chains.
Alternation rate (%)=C/(A+B+C)×100
A: the number of Vs that are combined with two Vs such as -V-V-V- B: the number of Vs that are combined with V and T such as -V-V-T- C: -T-V- Number of Vs bonded to two Ts like T- (T: fluorine-containing olefin unit, V: vinyl ester monomer unit)
The number of V units of A, B, and C is H of the main chain bonded to the tertiary carbon of the vinyl ester monomer unit (—CH ₂ —CH(O(C═O)R)—) of ¹ H-NMR measurement. Calculated from the intensity ratio of.

In WO 2015/137284, it is described that the higher the alternating ratio of the fluorinated olefin unit and the vinyl alcohol unit of the fluorinated copolymer, the higher the dispersibility of the pigment and the uniformity of the crosslinking. There is.
When the detailed examination in the present invention is advanced, the heat resistance is improved when the alternating ratio of the fluorinated olefin unit and the vinyl alcohol unit is increased, but the crystallinity is also improved. It was found that the coating film is likely to become opaque (has high haze value) due to scattering. This is a big problem when you want to use it as a clear paint without adding a pigment. Therefore, the alternating rate is preferably 50% or less, for example.
In addition, a structure such as —CF ₂ —CH(OH)— is formed in a portion where the fluorinated olefin unit and the vinyl alcohol unit are alternated in the copolymer. In this case, the acidity of the hydroxyl group directly bonded to the carbon atom to which —CF ₂ — is bonded is as high as that of phenol, and the metal is corroded when it comes into direct contact, but the inventors of the present invention have made diligent studies. It was found that when the alternating rate was high, the corrosiveness was high, and as the alternating rate was low, the corrosiveness was low, and when the alternating rate was 50% or less, the corrosiveness was almost lost.
Thus, in the use of clear paints requiring rust prevention, the alternating ratio of the fluorinated olefin unit and the vinyl alcohol unit is preferably 50% or less.

The above-mentioned fluorine-containing copolymer may have a monomer unit other than the fluorine-containing olefin unit, the vinyl alcohol unit and the vinyl ester monomer unit as long as the effect of the present invention is not impaired.

Examples of the other monomer include monomers containing no fluorine atom (excluding vinyl alcohol and vinyl ester monomers), for example, ethylene, propylene, 1-butene, 2-butene, vinyl chloride, At least one fluorine-free ethylenic monomer selected from the group consisting of vinylidene chloride, vinyl ether monomer, and unsaturated carboxylic acid is preferable.

The total content of the other monomer units is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, and more preferably 0 to 40 mol% of all the monomer units of the fluorocopolymer. It is more preferably 30 mol%.

In the present specification, the content of each monomer unit constituting the fluorocopolymer can be calculated by appropriately combining NMR, FT-IR, and elemental analysis depending on the type of monomer.

The weight average molecular weight of the above-mentioned fluorine-containing copolymer is not particularly limited, but is preferably 9,000 or more, more preferably 10,000 or more. It is more preferably 20,000 to 2,000,000, and particularly preferably 30,000 to 1,000,000. The weight average molecular weight is also preferably 200,000 or less, 150,000 or less, or 100,000 or less.
The weight average molecular weight can be determined by gel permeation chromatography (GPC).

The hydroxyl value of the above-mentioned fluorine-containing copolymer is 200 mgKOH/g or more because a further excellent anticorrosion effect can be obtained and a coating film which is further excellent in transparency, antifouling property and adhesion can be formed. Is preferred. As said hydroxyl value, 400 mgKOH/g or more is more preferable, 500 mgKOH/g or more is still more preferable, 1000 mgKOH/g or less is preferable, and 800 mgKOH/g or less is more preferable.

The hydroxyl value can be measured by a method based on JIS K 0070 or a calculation from a nuclear magnetic resonance method.

The rust-preventive coating composition of the present invention is suitable for preventing corrosion for joints of dissimilar metals. Examples of the dissimilar metal joint include the dissimilar metal joint of the electric wire shown in FIG. 2 and the dissimilar metal joint of the pipe shown in FIG.
Here, the dissimilar metals are two metals (A) and (B), respectively, and when the standard electrode potentials thereof are EA and EB, a combination in which the difference between EA and EB is 0.1 volt or more is dissimilar metal. Call me When the standard electrode potentials are separated by 0.1 volt or more, when the metals are in contact with each other, corrosion is more likely to proceed than when the metals are present alone. The larger the difference, the more likely it is to corrode, and the corrosion at that time occurs more on the metal side having a lower standard electrode potential.
As a concrete example,
In the case of copper (0.34V) and aluminum (-1.66V), corrosion occurs on the aluminum side.
In the case of iron (-0.44V) and aluminum (-1.66V), corrosion occurs on the aluminum side.
In the case of zinc (-0.76V) and aluminum (-1.66V), corrosion occurs on the aluminum side.
In the case of nickel (-0.25V) and aluminum (-1.66V), corrosion occurs on the aluminum side.
In the case of tin (-0.14V) and aluminum (-1.66V), corrosion occurs on the aluminum side.
In the case of iron (-0.44V) and zinc (-0.76V), corrosion occurs on the zinc side.
In the case of tin (-0.14V) and iron (-0.44V), corrosion occurs on the iron side.
In the case of nickel (-0.25V) and zinc (-0.76V), corrosion occurs on the zinc side.
In the case of copper (0.34V) and iron (-0.44V), corrosion occurs on the iron side.
In the case of copper (0.34V) and nickel (-0.25V), corrosion occurs on the nickel side.
In the case of copper (0.34V) and zinc (-0.76V), corrosion occurs on the zinc side.
In the case of copper (0.34V) and tin (-0.14V), corrosion occurs on the tin side.
In the case of SUS, there are multiple metal species, and the value of the standard electrode potential is almost the same as that of copper.
In the case of SUS (about 0.34V, copper value) and aluminum (-1.66V), corrosion occurs on the aluminum side.
In the case of SUS (about 0.34V, copper value) and iron (-0.44V), corrosion occurs on the iron side.
In the case of SUS (about 0.34V, copper value) and zinc (-0.76V), corrosion occurs on the zinc side.
In the case of SUS (about 0.34V, copper value) and tin (-0.14V), corrosion occurs on the tin side.
The same applies to aluminum alloys. It has a value in the range of -1.53V to -0.40V depending on its composition.
In the case of copper (0.34V) and aluminum alloy (-1.53V to -0.40V), corrosion occurs on the aluminum alloy side.
Table 1 shows standard electrode potentials of typical metals.

The combinations exemplified here are concrete examples of the different metals.
The dissimilar metals include aluminum or aluminum alloy and copper, aluminum or aluminum alloy and iron, aluminum or aluminum alloy and zinc, aluminum or aluminum alloy and nickel, aluminum or aluminum alloy and tin, copper and iron, copper and zinc, and copper. Nickel or copper and tin are preferred.
Oxygen and water are required for the progress of corrosion accompanying this dissimilar metal joining, and the rust-preventive coating composition of the present invention exhibits high barrier properties against oxygen and water vapor, and low water absorption, so that rust can be effectively removed. Occurrence is suppressed.
Further, the dissimilar metal indicates a state at a joint portion produced when the article (A) and the article (B) are joined, and does not indicate a state of the dissimilar metal produced inside an alloy such as SUS. Further, in the case of an article in which a thin film of tin or zinc is formed on the outermost surface of an iron plate such as tin plate or galvanized iron, tin or zinc on the outermost surface corresponds to the different metal species, not iron. That is, when the article (A) is tin, the metal species is tin, and when the article (B) is tin, the metal species is zinc.
The dissimilar metal joint part means a dissimilar metal joint part of an electric wire, or a dissimilar metal joint part of a pipe, or a joint part when a metal plate or a metal member is fixed with a metal screw or bolt, a metal duct. And the metal wall joints. Specific dissimilar metal joints include joints between aluminum core wires and copper core wires, joints between aluminum pipes and SUS pipes, metal plates made of tin (tin) or tin (zinc) and SUS. The fixing part with the machine screw can be mentioned.
Further, in recent years, lightweight aluminum wiring has attracted attention as an electric wire, but corrosion at a joint portion of a substrate with copper has become a problem, and the present invention is also applicable to a joint portion between an aluminum core wire and copper such as a printed circuit board. The anti-corrosion paint can be preferably used.
It has been found that the rust-preventive coating composition of the present invention exhibits particularly excellent rust-preventive properties for dissimilar metal joints because it comprises a fluorocopolymer having the following properties.
Characteristic (a): Water vapor permeability per 100 μm is 25 g/m ² ·day or less Characteristic (b): Oxygen permeability coefficient is 2.0E-13 cc·cm/cm ² ·sec·cmHg or less Characteristic (c): Water absorption rate Is 10 mass% or less

Further, the rust-preventive coating composition of the present invention exhibits excellent rust-preventive properties for steel plates, cast iron, high-temperature and high-pressure cast steel, or aluminum-zinc alloy-plated steel plates, and has transparency, antifouling properties and adhesion. Because it can form a superior coating film, it can be used for offshore structures, kitchen appliances, metal pipes for automobiles, exteriors with high designability, pipes for water and wastewater treatment facilities, and wiring for various power generation facilities or pipes. It can be suitably used as a rust paint.

Examples of the dissimilar metal joint include an electric wire dissimilar metal joint, a pipe dissimilar metal joint, and the like. The dissimilar metal bonding part may be mechanically bonded or chemically bonded as long as the dissimilar metals are bonded.

The dissimilar metals include aluminum or aluminum alloy and copper, aluminum or aluminum alloy and iron, aluminum or aluminum alloy and zinc, aluminum or aluminum alloy and nickel, aluminum or aluminum alloy and tin, copper and iron, copper and zinc, and copper. It is preferably nickel or copper and tin.
Here, as the aluminum alloy, aluminum 2000 series (Al-Cu-Mg series: aluminum copper magnesium alloy) aluminum alloy, aluminum 3000 series (Al-Mn series: aluminum manganese alloy) aluminum alloy, aluminum 4000 series (Al-Si). Series: Aluminum-silicon alloy) Aluminum alloy, Aluminum 5000 series (Al-Mg system: Aluminum magnesium alloy) Aluminum alloy, Aluminum 6000 series (Al-Mg-Si system: Aluminum-magnesium silicon alloy) Aluminum alloy, Aluminum 7000 series (Al- Zn-Mg system: aluminum zinc magnesium alloy) aluminum alloy, or aluminum 8000 system (Li addition system: aluminum lithium alloy) aluminum alloy is preferable. Duralumin is an aluminum alloy of aluminum 7000 series.

To prevent corrosion of dissimilar metal joints, marine structures, kitchen appliances, metal pipes for automobiles, highly-designed exteriors, pipes inside water and wastewater treatment facilities, or wiring inside various power generation facilities or pipes The use of rust paint is also one of the preferred embodiments of the present invention.

The anticorrosive paint of the present invention preferably contains a curing agent. Since the fluorine-containing copolymer has a hydroxyl group, a cured coating film can be formed from the rust-preventive coating material of the present invention. The cured coating film formed from the rust-preventive coating material of the present invention exhibits an even more excellent rust-preventing effect as compared with the non-curing coating film, and is further excellent in transparency, antifouling property and adhesion.

The curing agent may be of any type as long as it crosslinks the hydroxyl groups in the fluorine-containing copolymer, but an isocyanate curing agent, an amino resin curing agent or the like is preferable.

As the isocyanate-based curing agent, among others, a polyisocyanate compound derived from at least one isocyanate selected from the group consisting of xylylene diisocyanate (XDI) and bis(isocyanatomethyl)cyclohexane (hydrogenated XDI, H6XDI), hexa At least one selected from the group consisting of a blocked isocyanate compound based on methylene diisocyanate (HDI), a polyisocyanate compound derived from hexamethylene diisocyanate (HDI), and a polyisocyanate compound derived from isophorone diisocyanate (IPDI) Compounds are preferred.

The curing agent is derived from at least one isocyanate selected from the group consisting of xylylene diisocyanate (XDI) and bis(isocyanatomethyl)cyclohexane (hydrogenated XDI, H6XDI) (hereinafter, also referred to as isocyanate (i)). When a polyisocyanate compound (hereinafter, also referred to as polyisocyanate compound (I)) is used, the adhesiveness between the cured coating film obtained from the rust-preventive coating material of the present invention and the metal substrate becomes more excellent. ..

Examples of the polyisocyanate compound (I) include an adduct obtained by addition-polymerizing the above-mentioned isocyanate (i) with a trivalent or more aliphatic polyhydric alcohol, an isocyanurate structure (nurate) comprising the above-mentioned isocyanate (i). And a biuret composed of the above-mentioned isocyanate (i).

（式中、Ｒ^６は、炭素数３〜２０の脂肪族炭化水素基を表す。Ｒ^７は、フェニレン基又はシクロヘキシレン基を表す。ｋは、３〜２０の整数である。）で表される構造を有するものが好ましい。
上記一般式（３）中のＲ^６は、上記３価以上の脂肪族多価アルコールに基づく炭化水素基であり、炭素数３〜１０の脂肪族炭化水素基がより好ましく、炭素数３〜６の脂肪族炭化水素基が更に好ましい。
上記Ｒ^７がフェニレン基である場合、１，２−フェニレン基（ｏ−フェニレン基）、１，３−フェニレン基（ｍ−フェニレン基）、及び、１，４−フェニレン基（ｐ−フェニレン基）のいずれであってもよい。中でも、１，３−フェニレン基（ｍ−フェニレン基）が好ましい。また、上記一般式（３）中の全てのＲ^７が同じフェニレン基であってもよく、２種以上が混在していてもよい。
上記Ｒ^７がシクロヘキシレン基である場合、１，２−シクロヘキシレン基、１，３−シクロヘキシレン基、及び、１，４−シクロヘキシレン基のいずれであってもよい。中でも、１，３−シクロヘキシレン基が好ましい。また、上記一般式（３）中の全てのＲ^７が同じシクロヘキシレン基であってもよく、２種以上が混在していてもよい。
上記ｋは、３価以上の脂肪族多価アルコールの価数に対応する数である。上記ｋとして、より好ましくは３〜１０の整数であり、更に好ましくは３〜６の整数である。Examples of the adduct include the following general formula (3):

(In formula, R< ⁶ > represents a C3-C20 aliphatic hydrocarbon group. R< ⁷ > represents a phenylene group or a cyclohexylene group. k is an integer of 3-20.). Those having a structure having
R ⁶ in the general formula (3) is a hydrocarbon group based on the above-mentioned trivalent or higher valent aliphatic polyhydric alcohol, more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and 3 to 6 carbon atoms. The aliphatic hydrocarbon group of is more preferable.
When R ⁷ is a phenylene group, a 1,2-phenylene group (o-phenylene group), a 1,3-phenylene group (m-phenylene group), and a 1,4-phenylene group (p-phenylene group) It may be either. Of these, a 1,3-phenylene group (m-phenylene group) is preferable. Further, all R ⁷ in the general formula (3) may be the same phenylene group, or two or more kinds may be mixed.
When R ⁷ is a cyclohexylene group, it may be any of a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, and a 1,4-cyclohexylene group. Of these, a 1,3-cyclohexylene group is preferable. Further, all R ⁷ in the general formula (3) may be the same cyclohexylene group, or two or more kinds may be mixed.
The above k is a number corresponding to the valence of the trihydric or higher aliphatic polyhydric alcohol. The above k is more preferably an integer of 3 to 10, and still more preferably an integer of 3 to 6.

で表されるイソシアヌレート環を１個又は２個以上有するものである。
上記イソシアヌレート構造体としては、上記イソシアネートの三量化反応により得られる三量体、五量化反応により得られる五量体、七量化反応により得られる七量体等を挙げることができる。The above isocyanurate structure has the following general formula (4):

It has one or two or more isocyanurate rings represented by.
Examples of the isocyanurate structure include a trimer obtained by the trimerization reaction of the above isocyanate, a pentamer obtained by the pentamerization reaction, and a heptamer obtained by the heptamerization reaction.

（式中、Ｒ^７は、一般式（３）中のＲ^７と同じである。）で表される三量体が好ましい。
すなわち、上記イソシアヌレート構造体は、キシリレンジイソシアネート及びビス（イソシアネートメチル）シクロヘキサンからなる群より選択される少なくとも１種のイソシアネートの三量体であることが好ましい。Among them, the following general formula (5):

(Wherein, R ⁷ has the general formula (3) is the same as R ⁷ in.) Trimer is preferably represented by.
That is, the isocyanurate structure is preferably a trimer of at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis(isocyanatomethyl)cyclohexane.

（式中、Ｒ^７は、一般式（３）中のＲ^７と同じである。）で表される構造を有する化合物であり、上記イソシアヌレート構造体を得る場合とは異なる条件下で、上記イソシアネートを三量化することにより、得ることができる。The biuret has the following general formula (6):

(Wherein, R ⁷ has the general formula (3) is the same as R ⁷ in.) Is a compound having a structure represented by, under different conditions than the case of obtaining the isocyanurate structure, the It can be obtained by trimerizing the isocyanate.

The polyisocyanate compound (I) includes, among others, the adduct, that is, at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis(isocyanatomethyl)cyclohexane, and an aliphatic polyhydric alcohol having a valence of 3 or more. And is preferably obtained by addition polymerization of

When the polyisocyanate compound (I) is an adduct of the isocyanate (i) and a trivalent or higher aliphatic polyhydric alcohol, the trivalent or higher aliphatic polyhydric alcohol is specifically glycerol. , Trimethylolpropane (TMP), 1,2,6-hexanetriol, trimethylolethane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,1,1-tris(bishydroxymethyl)propane, 2,2 -Trihydric alcohols such as bis(hydroxymethyl)butanol-3; tetrahydric alcohols such as pentaerythritol and diglycerol; pentahydric alcohols (pentit) such as arabit, ribitol, xylitol; sorbit, mannitol, galactitol, alodulcit, etc. And hexahydric alcohol (hexite). Of these, trimethylolpropane and pentaerythritol are particularly preferable.

Further, as the xylylene diisocyanate (XDI) used as a constituent component of the adduct, 1,3-xylylene diisocyanate (m-xylylene diisocyanate), 1,2-xylylene diisocyanate (o-xylylene diisocyanate), 1 , 4-xylylene diisocyanate (p-xylylene diisocyanate) can be mentioned, among which 1,3-xylylene diisocyanate (m-xylylene diisocyanate) is preferable.

Further, as bis(isocyanate methyl)cyclohexane (hydrogenated XDI, H6XDI) used as a constituent component of the adduct, 1,3-bis(isocyanate methyl)cyclohexane, 1,2-bis(isocyanate methyl)cyclohexane, 1, 4-bis(isocyanatomethyl)cyclohexane may be mentioned, among which 1,3-bis(isocyanatomethyl)cyclohexane is preferred.

Suitable for the present invention by addition-polymerizing at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis(isocyanatomethyl)cyclohexane and the above-mentioned trivalent or higher aliphatic polyhydric alcohol. The adduct used for is obtained.

（式中、Ｒ^８は、フェニレン基又はシクロヘキシレン基を表す。）で表される化合物、すなわち、キシリレンジイソシアネート及びビス（イソシアネートメチル）シクロヘキサンからなる群より選択される少なくとも１種のイソシアネートと、トリメチロールプロパン（ＴＭＰ）と、を付加重合することにより得られるポリイソシアネート化合物を挙げることができる。
上記一般式（７）中のＲ^８で表されるフェニレン基又はシクロヘキシレン基については、上記一般式（３）におけるＲ^７について述べたとおりである。Specific examples of the adduct preferably used in the present invention include the following general formula (7):

(In the formula, R ⁸ represents a phenylene group or a cyclohexylene group.), that is, at least one isocyanate selected from the group consisting of xylylene diisocyanate and bis(isocyanatomethyl)cyclohexane, Examples thereof include polyisocyanate compounds obtained by addition-polymerizing trimethylolpropane (TMP).
The phenylene group or cyclohexylene group represented by R ⁸ in the general formula (7) is as described for R ⁷ in the general formula (3).

Examples of commercially available polyisocyanate compounds represented by the general formula (7) include Takenate D110N (manufactured by Mitsui Chemicals, Inc., adduct of XDI and TMP, NCO content: 11.8%), Takenate D120N (manufactured by Mitsui Chemicals). , H6XDI and TMP adduct, NCO content 11.0%), and the like.

When the polyisocyanate compound (I) is an isocyanurate structure, specific examples thereof include Takenate D121N (manufactured by Mitsui Chemicals, Inc., H6XDI nitrate, NCO content 14.0%), Takenate D127N (manufactured by Mitsui Chemicals, Inc., H6XDI nurate, H6XDI trimer, NCO content 13.5%) and the like.

By using a block isocyanate based on hexamethylene diisocyanate (HDI) (hereinafter, also simply referred to as a block isocyanate) as the curing agent, the rust-preventive coating composition of the present invention has a longer pot life (pot life). ..
As the above-mentioned blocked isocyanate, those obtained by reacting a polyisocyanate compound derived from hexamethylene diisocyanate (hereinafter, also referred to as polyisocyanate compound (II)) with a blocking agent are preferable.
Examples of the polyisocyanate compound (II) include an adduct obtained by addition polymerization of hexamethylene diisocyanate and an aliphatic polyhydric alcohol having a valence of 3 or more, an isocyanurate structure (nurate structure) composed of hexamethylene diisocyanate, Further, biuret composed of hexamethylene diisocyanate can be mentioned.

（式中、Ｒ^９は、炭素数３〜２０の脂肪族炭化水素基を表す。ｋは、３〜２０の整数である。）で表される構造を有するものが好ましい。
上記一般式（８）中のＲ^９は、上記３価以上の脂肪族多価アルコールに基づく炭化水素基であり、炭素数３〜１０の脂肪族炭化水素基がより好ましく、炭素数３〜６の脂肪族炭化水素基が更に好ましい。
上記ｋは、３価以上の脂肪族多価アルコールの価数に対応する数である。上記ｋとして、より好ましくは３〜１０の整数であり、更に好ましくは３〜６の整数である。Examples of the adduct include the following general formula (8):

(In the formula, R ⁹ represents an aliphatic hydrocarbon group having 3 to 20 carbon atoms, and k is an integer of 3 to 20).
R ⁹ in the general formula (8) is a hydrocarbon group based on the above trivalent or more aliphatic polyhydric alcohol, more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and 3 to 6 carbon atoms. The aliphatic hydrocarbon group of is more preferable.
The above k is a number corresponding to the valence of the trihydric or higher aliphatic polyhydric alcohol. The above k is more preferably an integer of 3 to 10, and still more preferably an integer of 3 to 6.

で表されるイソシアヌレート環を１個又は２個以上有するものである。
上記イソシアヌレート構造体としては、上記イソシアネートの三量化反応により得られる三量体、五量化反応により得られる五量体、七量化反応により得られる七量体等を挙げることができる。The above isocyanurate structure has the following general formula (4):

It has one or two or more isocyanurate rings represented by.
Examples of the isocyanurate structure include a trimer obtained by the trimerization reaction of the above isocyanate, a pentamer obtained by the pentamerization reaction, and a heptamer obtained by the heptamerization reaction.

で表される三量体が好ましい。Among them, the following general formula (9):

A trimer represented by

で表される構造を有する化合物であり、上記イソシアヌレート構造体を得る場合とは異なる条件下で、ヘキサメチレンジイソシアネートを三量化することにより、得ることができる。The biuret has the following general formula (10):

It is a compound having a structure represented by and can be obtained by trimerizing hexamethylene diisocyanate under conditions different from those for obtaining the above isocyanurate structure.

A compound having active hydrogen is preferably used as the blocking agent. As the compound having active hydrogen, for example, it is preferable to use at least one selected from the group consisting of alcohols, oximes, lactams, active methylene compounds, and pyrazole compounds.

Thus, the blocked isocyanate is obtained by reacting a polyisocyanate compound derived from hexamethylene diisocyanate with a blocking agent, and the blocking agent is an alcohol, oxime, lactam, active methylene compound. And at least one selected from the group consisting of pyrazole compounds is one of the preferred embodiments of the present invention.

When the polyisocyanate compound (II) for obtaining the blocked isocyanate is an adduct of hexamethylene diisocyanate and a trivalent or higher aliphatic polyhydric alcohol, specific examples of the trivalent or higher aliphatic polyhydric alcohol include Examples include glycerol, trimethylolpropane (TMP), 1,2,6-hexanetriol, trimethylolethane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,1,1-tris(bishydroxymethyl)propane. , 2,2-bis(hydroxymethyl)butanol-3 and other trihydric alcohols; pentaerythritol, diglycerol and other tetrahydric alcohols; arabite, ribitol, xylitol and other pentahydric alcohols (pentit); sorbit, mannitol, moth Hexahydric alcohols (hexit) such as lactitol and alodulcit are mentioned. Of these, trimethylolpropane and pentaerythritol are particularly preferable.
The above adduct is obtained by addition-polymerizing hexamethylene diisocyanate and the above-mentioned trivalent or more polyhydric aliphatic alcohol.

Specific examples of the compound having active hydrogen to be reacted with the polyisocyanate compound (II) include alcohols such as methanol, ethanol, n-propanol, isopropanol, and methoxypropanol; acetone oxime, 2-butanone oxime, cyclohexanone. Oximes such as oximes;-lactams such as caprolactam; active methylene compounds such as methyl acetoacetate and ethyl malonate; pyrazole compounds such as 3-methylpyrazole, 3,5-dimethylpyrazole, and 3,5-diethylpyrazole. And one or more of these can be used.
Of these, active methylene compounds and oximes are preferable, and active methylene compounds are more preferable.

Examples of commercially available blocked isocyanates include Duranate K6000 (Asahi Kasei Chemicals Corporation, HDI active methylene compound block isocyanate), Duranate TPA-B80E (Asahi Kasei Chemicals Corporation), Duranate MF-B60X (Asahi Kasei Chemicals Corporation), Duranate 17B. -60PX (manufactured by Asahi Kasei Chemicals Co., Ltd.), Coronate 2507 (manufactured by Nippon Polyurethane Company), Coronate 2513 (manufactured by Nippon Polyurethane Company), Coronate 2515 (manufactured by Nippon Polyurethane Company), Sumijour BL-3175 (manufactured by Sumika Bayer Urethane Company), Luxate HC1170 (made by Olin Chemicals), LuxateHC2170 (made by Olin Chemicals), etc. are mentioned.

A polyisocyanate compound derived from hexamethylene diisocyanate (HDI) (hereinafter, also referred to as polyisocyanate compound (III)) can also be used as a curing agent. Examples of the polyisocyanate compound (III) include those described above as the polyisocyanate compound (II).

Specific examples of the polyisocyanate compound (III) include Coronate HX (manufactured by Nippon Polyurethane Company, isocyanurate structure of hexamethylene diisocyanate, NCO content 21.1%), Sumidule N3300 (manufactured by Sumika Bayer, hexamethylene). Diisocyanate isocyanurate structure), Takenate D170N (Mitsui Chemicals, Inc., hexamethylene diisocyanate isocyanurate structure), Sumidule N3800 (Sumitomo Bayer, hexamethylene diisocyanate isocyanurate structure prepolymer type), etc. Are listed.

As the curing agent, a polyisocyanate compound derived from isophorone diisocyanate (IPDI) (hereinafter, also referred to as polyisocyanate compound (IV)) can be used.

Examples of the polyisocyanate compound (IV) include an adduct obtained by addition-polymerizing isophorone diisocyanate and an aliphatic polyhydric alcohol having a valence of 3 or more, an isocyanurate structure composed of isophorone diisocyanate (a nurate structure), and A biuret made of isophorone diisocyanate can be mentioned.

（式中、Ｒ^１０は、炭素数３〜２０の脂肪族炭化水素基を表す。Ｒ^１１は、下記一般式（１２）：

で表される基である。ｋは、３〜２０の整数である。）で表される構造を有するものが好ましい。Examples of the adduct include the following general formula (11):

(In the formula, R ¹⁰ represents an aliphatic hydrocarbon group having 3 to 20 carbon atoms. R ¹¹ represents the following general formula (12):

Is a group represented by. k is an integer of 3 to 20. Those having a structure represented by

R< ¹⁰ > in the said General formula (11) is a hydrocarbon group based on the said trivalent or more aliphatic polyhydric alcohol, a C3-C10 aliphatic hydrocarbon group is more preferable, and a C3-C6. The aliphatic hydrocarbon group of is more preferable.
The above k is a number corresponding to the valence of the trihydric or higher aliphatic polyhydric alcohol. The above k is more preferably an integer of 3 to 10, and still more preferably an integer of 3 to 6.

で表されるイソシアヌレート環を１個又は２個以上有するものである。
上記イソシアヌレート構造体としては、イソホロンジイソシアネートの三量化反応により得られる三量体、五量化反応により得られる五量体、七量化反応により得られる七量体等を挙げることができる。The above isocyanurate structure has the following general formula (4):

It has one or two or more isocyanurate rings represented by.
Examples of the isocyanurate structure include a trimer obtained by the trimerization reaction of isophorone diisocyanate, a pentamer obtained by the pentamerization reaction, and a heptamer obtained by the heptamerization reaction.

（式中、Ｒ^１１は、一般式（１１）中のＲ^１１と同じである。）で表される三量体が好ましい。すなわち、上記イソシアヌレート構造体は、イソホロンジイソシアネートの三量体であることが好ましい。Among them, the following general formula (13):

^{(Wherein, R 11} has the general formula (11) is the same as ^{R 11} in.) Trimer is preferably represented by. That is, the isocyanurate structure is preferably a trimer of isophorone diisocyanate.

（式中、Ｒ^１１は、一般式（１１）中のＲ^１１と同じである。）で表される構造を有する化合物であり、上記イソシアヌレート構造体を得る場合とは異なる条件下で、イソホロンジイソシアネートを三量化することにより、得ることができる。The biuret has the following general formula (14):

(Wherein, R ¹¹ has the general formula (11) in the same as R ¹¹ in.) Is a compound having a structure represented by, under different conditions than the case of obtaining the isocyanurate structure, isophorone It can be obtained by trimerizing diisocyanate.

Among them, the polyisocyanate compound (IV) is preferably at least one selected from the group consisting of the adduct and the isocyanurate structure. That is, the polyisocyanate compound (IV) is selected from the group consisting of an adduct obtained by addition polymerization of isophorone diisocyanate and an aliphatic polyhydric alcohol having a valence of 3 or more, and an isocyanurate structure composed of isophorone diisocyanate. It is preferable that it is at least one kind.

When the polyisocyanate compound (IV) is an adduct of isophorone diisocyanate and an aliphatic polyhydric alcohol having a valence of 3 or more, the aliphatic polyhydric alcohol having a valence of 3 or more includes glycerol and trimethylol. Propane (TMP), 1,2,6-hexanetriol, trimethylolethane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,1,1-tris(bishydroxymethyl)propane, 2,2-bis( Hydroxymethyl)butanol-3 and other trihydric alcohols; pentaerythritol, diglycerol and other tetrahydric alcohols; arabite, ribitol, xylitol and other pentahydric alcohols (pentit); sorbit, mannitol, galactitol, alodulcit and other hexahydric alcohols. Alcohol (hexite) etc. are mentioned. Of these, trimethylolpropane and pentaerythritol are particularly preferable.

Addition polymerization of isophorone diisocyanate and the above-mentioned trivalent or higher polyhydric aliphatic alcohol gives an adduct suitably used in the present invention.

（式中、Ｒ^１２は、下記一般式（１２）：

で表される基である。）で表される化合物、すなわち、イソホロンジイソシアネートとトリメチロールプロパン（ＴＭＰ）とを付加重合することにより得られるポリイソシアネート化合物を挙げることができる。Specific examples of the adduct preferably used in the present invention include the following general formula (15):

(In the formula, R ¹² is the following general formula (12):

Is a group represented by. ), that is, a polyisocyanate compound obtained by addition-polymerizing isophorone diisocyanate and trimethylolpropane (TMP).

As a commercially available product of the polyisocyanate compound represented by the general formula (12) (TMP adduct of isophorone diisocyanate), Takenate D140N (manufactured by Mitsui Chemicals, Inc., NCO content: 11%) and the like can be mentioned.

Examples of commercially available isocyanurate structures composed of isophorone diisocyanate include Desmodur Z4470 (manufactured by Sumika Bayer Urethane Co., NCO content 11%).

Among them, Takenate D120N (manufactured by Mitsui Chemicals, Inc., NCO content: 11%) and Sumidule N3300 (manufactured by Sumika Bayer, isocyanurate structure of hexamethylene diisocyanate) are more preferable as the curing agent.

The above isocyanate-based curing agents may be used alone or in combination of two or more.

Examples of the amino resin-based curing agent include polyamine compounds, melamine resins, urea resins, benzoguanamine resins, and glycoluril resins.

Examples of the polyamine compound include low molecular weight diamines such as 1,2-ethanediamine, 1,3- and 1,3-propanediamine, and 1,4-butanediamine; tetraamines such as 1,2,5-pentanetriamine; For example, tetraamine such as 1,2,4,5-benzenetetraamine may be mentioned.

As the melamine resin, a compound obtained by reacting a methylolmelamine derivative obtained by condensing melamine and formaldehyde with a lower alcohol such as methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, or isobutyl alcohol to form an ether, and a mixture thereof. Can be preferably mentioned.

Examples of the methylolmelamine derivative include monomethylolmelamine, dimethylolmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, hexamethylolmelamine, and the like.

The melamine resin is classified into a complete alkyl type, a methylol group type, an imino group type, and a methylol/imino group type depending on the ratio of alkoxylation, and any of them can be used in the present invention.

When a polyisocyanate compound, a polyamine compound, or a melamine resin is used among the above curing agents, since the curing agent has a relatively large molecular weight, the elastic modulus after curing is suppressed, thereby increasing the bending strength and toughness as a coating film. It is possible and preferable. Further, the scratching property of the surface of the coating film is suppressed, and the self-repairing property is exhibited.

The above-mentioned curing agent is preferably blended so that the equivalent ratio to the hydroxyl group portion of the fluorocopolymer is 0.5 to 1.5, and more preferably 0.8 to 1.2. ..

The rust preventive coating composition of the present invention may contain a curing catalyst, if necessary. The curing catalyst is used to accelerate the curing reaction and impart excellent chemical and physical properties to the cured film. In particular, when curing at low temperature in a short time, it is preferable to include a curing catalyst.
As the curing catalyst, a known catalyst can be used and may be appropriately selected depending on the type of curing agent.
For example, when the curing agent is an isocyanate type curing agent or a blocked isocyanate type curing agent, the curing catalyst is preferably a tin catalyst, a zirconium catalyst or the like.
Examples of the tin catalyst include tin octylate, tributyltin dilaurate, dibutyltin dilaurate and the like.
Examples of the zirconium catalyst include zirconium chelate and the like. Examples of commercially available zirconium catalysts include "K-KAT XC-4205" (trade name, manufactured by Kusumoto Kasei Co., Ltd.).
When the curing agent is an amine type curing agent, a blocked acid catalyst is preferable as the curing catalyst.
Examples of the blocked acid catalyst include amine salts of various acids such as carboxylic acid, sulfonic acid and phosphoric acid. Of these, higher alkyl-substituted sulfonic acid amine salts such as diethanolamine salt or triethylamine salt of p-toluenesulfonic acid and diethanolamine salt or triethylamine salt of dodecylbenzenesulfonic acid are preferable.
The curing catalyst may be used alone or in combination of two or more.
The above-mentioned curing catalyst is preferably added in an amount of 0.00001 to 10% by mass, and more preferably 0.0001 to 5% by mass, based on the total amount of the fluorocopolymer and the curing agent.

The fluorine-containing copolymer preferably has solubility in an alcohol solvent because it is easy to handle. In this specification, having solubility means that the above-mentioned fluorine-containing copolymer becomes invisible when 5% by mass of the above-mentioned fluorine-containing copolymer is dissolved in an alcohol solvent. Also, having solubility in an alcoholic solvent is sufficient if it is soluble in at least one alcoholic solvent and does not need to be soluble in all alcoholic solvents.

The alcohol solvent is preferably an alcohol having 1 to 10 carbon atoms, and examples thereof include methanol, ethanol, normal propyl alcohol, isopropyl alcohol, normal butanol, isobutyl alcohol, tertiary butyl alcohol, pentanol, hexanol, heptanol, and octanol. Can be mentioned. The above-mentioned fluorine-containing copolymer preferably has solubility in methanol.

The rust-preventive coating material of the present invention can be prepared in the form of a solvent-based coating material, a water-based coating material, a powder-type coating material or the like by a conventional method. Among them, the form of solvent-based paint is preferable from the viewpoints of easy film formation, good drying property, and the like. That is, the rust-preventive coating material of the present invention preferably further contains a solvent. By including the solvent, thin film coating becomes easier, and the obtained coating film can be made thinner.

The solvent is preferably an organic solvent, and esters such as ethyl acetate, butyl acetate, isopropyl acetate, isobutyl acetate, cellosolve acetate, propylene glycol methyl ether acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; tetrahydrofuran. , Cyclic ethers such as dioxane; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; aromatic hydrocarbons such as xylene, toluene and solvent naphtha; glycols such as propylene glycol methyl ether and ethyl cellosolve Ethers; diethylene glycol esters such as carbitol acetate; aliphatics such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, mineral spirits Hydrocarbons; mixed solvents thereof and the like can be mentioned.
Among them, esters and amides are preferable, and butyl acetate and N,N-dimethylacetamide are particularly preferable.

When the anticorrosive paint of the present invention is a solvent-based paint, the concentration of the fluorine-containing copolymer is preferably 5 to 95% by mass, and more preferably 10 to 70% by mass, based on 100% by mass of the total amount of the paint. preferable.
Another polymer may be further added to the rust-preventive coating material of the present invention within a range not impairing the effects of the present invention. The other polymer is a polymer that does not correspond to the above-mentioned fluorine-containing copolymer.
The other polymer may or may not have a curable group. Examples of the curable group include a hydroxyl group, a carboxy group, an amino group, an epoxy group, an alkoxysilyl group, and an isocyanate group.
Examples of other polymers include fluorine-containing polymers other than the above-mentioned fluorine-containing copolymers; acrylic resin, polyester resin, acrylic polyol resin, polyester polyol resin, urethane resin, acrylic silicone resin, silicone resin, alkyd resin, epoxy. Resins, non-fluorine-containing resins such as oxetane resins, amino resins and the like can be mentioned.
The other polymers may be used alone or in combination of two or more.
As the other polymer, those having compatibility with the above-mentioned fluorine-containing copolymer to obtain a uniform cured film are preferable because the cured film is likely to have gloss. In this case, the other polymer may be a thermosetting resin or a thermoplastic resin.
When the thermosetting resin is included as another polymer, it is preferable that the other polymer can be linked to the fluorine-containing copolymer by a curing agent. Specifically, a polyester resin or an acrylic resin containing a hydroxyl group, an epoxy group, a carbonyl group or the like at the terminal or side chain is preferable.
When the thermoplastic resin is included as another polymer, the other polymer preferably contains a polar group that interacts with the hydroxyl group of the fluorocopolymer, for example, an ester group. Specifically, a polyester resin or an acrylic resin having no curable group is preferable.
The content of the other polymer is preferably 0 to 100 parts by mass, and more preferably 5 to 75% by mass, based on 100 parts by mass of the fluorocopolymer.

The rust-preventive coating material of the present invention may further contain various additives depending on the required properties, as long as the effects of the present invention are not impaired. Examples of the additives include pigments, coupling agents, silica, pigment dispersants, defoamers, leveling agents, ultraviolet absorbers, light stabilizers, thickeners, adhesion improvers and matting agents.

Since the anticorrosive paint of the present invention has high transparency, the internal corrosion state can be visually confirmed. Therefore, it is very effective in a field where durability is required, for example, metal pipes inside vehicles, metal wiring, and marine structures such as bridges. It is also suitable as a rust-preventive coating on a metal surface that requires designability.

The present invention is also a coating film characterized by being formed from the above-mentioned rust preventive paint. The coating film may be a non-cured coating film or a cured coating film.

The above-mentioned non-cured coating film is obtained from the above-mentioned rust preventive coating material containing no above-mentioned hardening agent (however, not containing a hardening agent). The non-cured coating film can be produced, for example, by applying the above-mentioned rust-preventive paint to any base material and drying it.

The above-mentioned cured coating film is obtained from the above-mentioned rust preventive paint containing the above-mentioned hardening agent. The above-mentioned cured coating film can be produced, for example, by applying the above-mentioned rust-preventive paint to any base material and curing it. In the case of a solvent type paint, the above curing is preferably carried out at 10 to 300°C, preferably 100 to 200°C, for 30 seconds to 3 days. In the case of solvent-based paint or water-based paint, it is preferable to dry the coating film. Drying may be performed simultaneously with the above curing or separately. The coating film may be cured (and dried) and then cured. The curing is preferably performed at 20 to 300° C. for 1 minute to 3 days.

The thickness of the coating film is preferably 5 to 1000 μm from the viewpoint of rust prevention. The thickness is more preferably 7 to 500 μm, further preferably 10 to 100 μm.

The coating film of the present invention is capable of sufficiently preventing corrosion of metals and dissimilar metal joints, and is also excellent in transparency, antifouling property and adhesion, so for dissimilar metal joints, for marine structures, It can be suitably used as a coating film for kitchen appliances, metal pipes for automobiles, exteriors with high designability, pipes for water and wastewater treatment facilities, and wiring for various power generation facilities or pipes.

That is, to prevent corrosion of dissimilar metal joints, marine structures, kitchen appliances, automobile metal pipes, highly-designed exteriors, pipes in water and wastewater treatment facilities, or wiring in various power generation facilities or pipes, The use of the coating film is also one of the preferred embodiments of the present invention.

The anticorrosive paint and the coating film of the present invention can be applied to glass base materials, resin base materials, ceramic base materials, ceramic base materials, concrete base materials, metal base materials, etc. Therefore, it is preferable to apply it to the above metal base material. The present invention also provides a laminate including the above metal substrate and the above coating film.

Examples of the material for forming the metal base material include steel plates, cast iron, high temperature and high pressure cast steel, and aluminum-zinc alloy plated steel plates. FC200 is an example of cast iron. An example of the cast steel for high temperature and high pressure is SCPH2. Further, examples thereof include metals and metal compounds such as aluminum, nickel, titanium, molybdenum, magnesium, manganese, copper, silver, lead, tin, chromium, beryllium, tungsten and cobalt, and alloys composed of two or more of these. It can be selected according to the application.
The metal base material may have a dissimilar metal joint part in which dissimilar metals are joined. When the metal base material has a dissimilar metal joint, corrosion can be suppressed especially.

Specific examples of the alloys include stainless steel, alloy steel such as permalloy, aluminum alloys such as Al-Cu, Al-Mg, Al-Si, Al-Cu-Ni-Mg, and Al-Si-Cu-Ni-Mg. Copper alloys such as brass, bronze, silicon bronze, silicon brass, nickel silver, nickel bronze, nickel manganese (D nickel), nickel-aluminum (Z nickel), nickel-silicon, monel metal, constantan, nichrome inconel, hastelloy Examples include nickel alloys.

Also, for the purpose of preventing metal corrosion, etc., electroplating, hot dipping, chromizing, siliconizing, calorizing, sherading jig, thermal spraying and other metal coatings on the metal surface, or phosphate treatment A phosphate film may be formed, a metal oxide may be formed by anodic oxidation or thermal oxidation, or electrochemical protection may be applied. Examples of the hot-dipped metal base material include hot-dip galvanized steel sheet, hot-dip zinc-aluminum-magnesium alloy-plated steel sheet, hot-dip aluminum-zinc-plated steel sheet, hot-dip aluminum-plated steel sheet.

Furthermore, for the purpose of further improving the adhesiveness, the metal surface is subjected to chemical conversion treatment with phosphate, sulfuric acid, chromic acid, oxalic acid, sand blast, shot blast, grit blast, honing, paper scratch, wire scratch. A surface roughening treatment such as a hairline treatment may be performed, and the metal surface may be colored, printed, etched or the like for the purpose of design.

The laminate may have a primer layer. The primer layer is formed by a conventional method using a conventionally known primer coating material. Typical examples of the paint for the primer include epoxy resin, urethane resin, acrylic resin, silicone resin, polyester resin and the like.

In the laminate, it is also preferable that the metal base material and the coating film are in direct contact, and even if they are in direct contact, excellent adhesion can be obtained. In particular, when the coating film described above is a cured coating film, even higher adhesion can be obtained.

The laminate of the present invention is resistant to corrosion of the metal base material, can exhibit the aesthetic appearance of the metal base material sufficiently due to the high transparency of the coating film, and is excellent in antifouling property and adhesiveness. It can be suitably used as a laminated body for parts, marine structures, kitchen appliances, metal pipes for automobiles, exteriors with high designability, pipes for water and wastewater treatment facilities, and wiring for various power generation facilities or pipes. ..

That is, to prevent corrosion of dissimilar metal joints, marine structures, kitchen appliances, automobile metal pipes, highly-designed exteriors, pipes in water and wastewater treatment facilities, or wiring in various power generation facilities or pipes, The use of the laminate is also one of the preferred embodiments of the present invention.

An electric wire having a dissimilar metal joint and having a coating film formed from the above-mentioned rust preventive coating on the dissimilar metal joint is also one aspect of the present invention.
Since an electric current flows through an electric wire having a dissimilar metal joint, corrosion is likely to occur due to a slight amount of water or oxygen, and it is particularly required to suppress corrosion of the dissimilar metal joint.
The electric wire of the present invention can suppress the corrosion of the dissimilar metal joint by having the coating film formed from the rust preventive paint on the dissimilar metal joint.
The electric wire of the present invention includes a first core wire made of a metal (A) and a second core wire made of a metal (B) different from the metal (A), and the first core wire and the second core wire are made of different metals. It is preferable to have a coating film formed from the above-mentioned rust preventive paint on the dissimilar metal joint part including the part.
The dissimilar metal joint part may be mechanically joined as long as the metal (A) and the metal (B) are joined together, or the metal (A) and the metal (B) are chemically joined together. It may be joined.
In the electric wire of the present invention, the combination of the metal (A) and the metal (B) is not particularly limited, and examples thereof include the above-mentioned combinations of different metals. In particular, aluminum and copper, aluminum and gold, aluminum and nickel, and aluminum. And tin, or aluminum and silver are preferred.
The electric wire of the present invention preferably has a coating layer that covers the first core wire and the second core wire, if necessary. The material, thickness, etc. of the coating layer in the first core wire and the second core wire are not particularly limited, and conventionally known resins, thickness, etc. used in electric wires can be adopted.

As a specific mode of the electric wire of the present invention, for example, as shown in FIG. 2, a first core wire A1 made of a metal (A) and a second core wire B1 made of a metal (B) different from the metal (A). An example is a configuration including a dissimilar metal joint D1 in which and are joined, and having a coating film C1 formed from the above-mentioned rust preventive paint on the dissimilar metal joint D1.

A pipe having a dissimilar metal joint and having a coating film formed from the rust-preventive coating on the dissimilar metal joint is also one of preferred embodiments of the present invention.
Pipes having dissimilar metal joints are required to suppress corrosion of dissimilar metal joints because internal fluid leaks or external air acts on the internal fluid when corrosion occurs at the joints.
The pipe of the present invention can suppress the corrosion of the dissimilar metal joint by having the coating film formed from the rust preventive paint on the dissimilar metal joint.
The pipe of the present invention includes a first pipe made of a metal (A) and a second pipe made of a metal (B) different from the metal (A), and the first pipe and the second pipe. It is preferable to include a dissimilar metal joint part, and to have a coating film formed from the above rust-preventive paint on the dissimilar metal joint part.
The dissimilar metal joint part may be mechanically joined as long as the metal (A) and the metal (B) are joined together, or the metal (A) and the metal (B) are chemically joined together. It may be joined.
In the pipe of the present invention, the combination of the metal (A) and the metal (B) is not particularly limited, and examples thereof include combinations of the above-mentioned dissimilar metals. Particularly, aluminum and copper, SUS and iron, or aluminum and iron. Is preferred.
The structures and thicknesses of the first tube and the second tube are not particularly limited, and conventionally known structures and thicknesses can be adopted.

As a concrete aspect of the pipe of the present invention, for example, as shown in FIG. 3, a first pipe A2 made of a metal (A) and a second pipe B2 made of a metal (B) different from the metal (A). An example is a configuration including a dissimilar metal joint D2 in which and are joined, and having a coating film C2 formed from the above rust-preventive paint on the dissimilar metal joint D2.

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Each numerical value in the examples was measured by the following method.

(1) Haze value and total light transmittance Using a haze meter, the haze and transmittance of the film were measured according to JIS K7136.
(2) Measurement of Alternation Rate by NMR NMR measurement was performed under the following conditions, and the alternation rate was calculated from the results.
1H-NMR measurement condition: 400 MHz (tetramethylsilane=0 ppm)
(3) Weight average molecular weight, molecular weight distribution By gel permeation chromatography (GPC), a column manufactured by Shodex (one GPC LF-G, two Shodex GPC LF-604, and two GPC LF-601 in series). The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn) in terms of standard polystyrene are calculated from the data measured by flowing THF as a solvent at a flow rate of 1 ml/min. did.
(4) Pyrolysis temperature Using a differential thermogravimetric simultaneous measurement device (TG/DTA), measurement was performed under conditions of an air atmosphere at a temperature rising rate of 10° C./min, and evaluation was performed at a temperature of 1% mass reduction.
(5) Glass transition temperature Tg, melting point Tm
By differential scanning calorimetry, the temperature is raised (decreased) at a temperature range of -30°C to 150°C at a rate of 20°C/min (first run)-decreased temperature-increased (second run), and endothermic in second run The midpoint of the curve was taken as Tg (°C). The value of the endothermic peak of the second run was defined as Tm (°C).
(6) Adhesion According to JIS K5600-5-6 cross-cut method, a cross-cut test (1 mm x 1 mm x 25 squares) was performed, and the number of remaining squares was evaluated.
(7) Water vapor transmission test It was performed according to the cup method (JIS Z0208-1976) condition B (temperature 40±0.5° C., relative humidity 90±2%). From the obtained value (R) and the measured thickness (t (μm)), the water vapor permeability (P) per 100 μm was converted using the following formula.
P (100 μm)=R×100/t
(8) Antirust test Test condition A
After coating the galvanium steel plate (registered trademark) with the prepared coating material, it was air-dried at room temperature for 30 minutes and then dried by heating at 80° C. for 2 hours to prepare a coated plate. The periphery of the coated plate was protected with an aluminum tape, and a saline solution (50 g/L) was dropped on the plate at 5 locations, and the surface state was visually confirmed after holding at 35° C. and 90% RT for 4 days. As a standard, the base on which the saline solution was dropped was not changed, ○ was rusted on a part of the base, and × was rusted on the entire base.
Test condition B
After coating the galvanium steel sheet (registered trademark) with the coating material, the coating material was air-dried at room temperature for 30 minutes and then dried by heating at 80° C. for 2 hours to prepare a coated plate. The periphery of the coated plate was protected with aluminum tape, and a saline solution (50 g/L) was sprayed onto the plate so that the entire surface was wet, and the surface condition was visually confirmed after holding for 4 days at 35° C. and 90% RT. .. The criteria are that the base is ◯, no change, Δ is rust on part of the base, and x is rust on the entire base.
(9) Water absorption rate A film piece was immersed in water at room temperature of 23°C, the weight change was measured for several days, and the water absorption rate was saturated when compared with the previous day. The water absorption rate (Q) was calculated by the following formula. ..
Q (%) = (weight of saturated water absorption-initial weight)/initial weight x 100
(10) Hot water test After coating the coating material prepared on a glass plate with air for 30 minutes at room temperature, it was heated and dried at 80°C for 2 hours to prepare a coated plate. The glass plate coated with the coating film was immersed in warm water at 50° C. for 4 days, and the haze before and after was measured.
(11) Oxygen Permeability Coefficient A differential pressure type gas/vapor permeability measuring device was used for measurement according to JIS K 7126-1.
(12) About 5% by mass of a solvent-soluble solid polymer was added to the solution, and the mixture was shaken at room temperature (23° C.). After 24 hours, the state was visually confirmed. ◯ is dissolved, Δ is moisture-proof, and x is not dissolved.
(13) Magic Contamination Property According to JIS K6902, red, black and blue magic inks were applied, and after 16 hours, wiped off with ethanol, and the state of contamination was visually confirmed. ◯ indicates that it can be completely wiped off, Δ indicates that it has been wiped off, and x indicates that it can hardly be wiped off.

The polymers used in each example are as follows.
Polymer 1: Tetrafluoroethylene (TFE)/vinyl alcohol (VOH) copolymer (TFE/VOH=23.8/76.2 (mol %), weight average molecular weight: 46,000, molecular weight distribution (Mw/Mn) ): 2.01, alternating rate (VTV): 5.4%, thermal decomposition temperature: 256°C, Tg: 79°C, Tm: 192°C, hydroxyl value: 761 mgKOH/g
Each value was measured by the method described above.
Further, polymers 2 and 3 were used. The physical property values of each polymer are summarized in Table 2.

The following were used as comparative polymers.
Comparative polymer 1: Tetrafluoroethylene (TFE)/vinyl alcohol (VOH) copolymer (TFE/VOH=11/89 (mol %), weight average molecular weight: 252,000, molecular weight distribution (Mw/Mn): 2 .20, alternation rate (VTV): 0.9%, thermal decomposition temperature: 238°C, Tg: 87°C, Tm: 204°C, hydroxyl value: 995 mgKOH/g
Comparative polymer 2: tetrafluoroethylene (TFE)/vinyl alcohol (VOH) copolymer (TFE/VOH=47.8/52.2 (mol %), weight average molecular weight: 40,000, molecular weight distribution (Mw/ Mn): 1.77, alternation rate (VTV): 49.1%, thermal decomposition temperature: 321°C, Tg: 79°C, Tm: 206°C, hydroxyl value: 413 mgKOH/g
EVAL (R) L104B: Kureha Co., Ltd., ethylene (E)/vinyl alcohol (VOH) copolymer (E/VOH=27/73 (mol %)), Tg: 60° C., Tm: 165° C.
Poval: polyvinyl alcohol, a reagent purchased from Aldrich

Reference Examples 1-1 to 1-3 and Reference Comparative Examples 1-1 to 1-4: Solvent solubility of the solvent-soluble polymers 1 to 3 and the comparative polymers 1 and 2 was measured. The results are summarized in Table 3.

エバール（Ｒ）Ｌ１０４Ｂおよびポバール（ポリビニルアルコール）はメタノールへ溶解しない。

Eval® L104B and Poval (polyvinyl alcohol) are not soluble in methanol.

Examples 1-1 to 1-3 and Comparative Example 2:
A 15% by mass solution of polymer 1 in dimethylacetamide was prepared, and a film was formed on a PP (polypropylene) plate using a doctor blade of 10 mil. After air-drying at room temperature for 30 minutes, it was dried at 80° C. for 2 hours to obtain a coating film. Then, the coating film was peeled off from the PP plate to obtain a film.
Films were similarly prepared for Polymers 2 and 3 and Comparative Polymers 1 and 2.

Measurement of Oxygen Transmission Rate, Water Vapor Transmission Rate, and Water Absorption Rate Using the films obtained in Examples 1-1 to 1-3 and Comparative Example 2, the oxygen transmission rate, water vapor transmission rate, and water absorption rate were measured. The results are summarized in Table 4.

The water absorptions of Comparative Polymer 1 and EVAL (R) L104B were 20.6% and 20.3%, respectively. Further, since Poval (polyvinyl alcohol) exhibits water solubility, it was not tested.

Optical Properties The total light transmittance and haze of the films obtained in Examples 1-1 and 1-2 and Comparative Example 2 were measured. The results are summarized in Table 5.

Magic stain resistance The films obtained in Examples 1-1 to 1-3 were evaluated for magic stain resistance. The results are summarized in Table 6.

Examples 2-1 and 2-2
A 15% by mass solution of polymer 1 in dimethylacetamide was prepared, and 20% by mass of Sumidule N3300 manufactured by Sumika Bayer Urethane Co., Ltd. was added to the polymer as a curing agent to prepare a coating material. After forming a film on each substrate using a doctor blade of 10 mil, air-drying at room temperature for 30 minutes and then drying at 80° C. for 4 hours, and then the adhesion was evaluated.
Similarly, the polymer 2 was formed into a film, and the adhesion was evaluated. The results are shown in Table 7.

Regarding Examples 2-1 and 2-2, oxygen permeability, water vapor permeability, and water absorption were measured. The results are summarized in Table 8.

Examples 3-1 and 3-2 and Comparative Examples 3-1 to 3-3: Anticorrosion test 1
A 15 mass% dimethylacetamide solution of polymer 1 was prepared and used as a coating material. A rust prevention test was conducted using the paint. The rust prevention test was similarly performed on Polymer 2, Comparative Polymer 1, L104B and Poval. The results are shown in Table 9.

Examples 4-1 and 4-2: Hot water test A hot water test was performed using the samples formed on the glass plates prepared in Examples 2-1 and 2-2. The results are shown in Table 10.

Example 5 and Comparative Examples 5-1 to 5-3: Anticorrosion test 2
A 15% by mass solution of polymer 2 in dimethylacetamide was prepared, and 20% by mass of Sumidule N3300 manufactured by Sumika Bayer Urethane Co. was added to the polymer as a curing agent to prepare a coating material. Films were formed on various metal plates using a 10 mil doctor blade, air-dried at room temperature for 30 minutes, and then dried at 80° C. for 4 hours to obtain metal-coated plates. Then, in order to remove the influence of the surroundings, the periphery of the metal coated plate was protected with aluminum tape. After being immersed in 5% salt water and kept at 50° C. for 7 days, the appearance was visually evaluated. The evaluation criteria are as follows.
◯: No change, Δ: Partly rusted, X: Rusted entirely. Similarly, Comparative Polymers 1, 2 and L104B were evaluated for rust prevention. The results are summarized in Table 11.

Dissimilar metal bonding (copper plate-aluminum foil)
As shown in FIG. 1, a 3 mmφ hole is drilled in a copper plate 1 having a thickness of 0.5 mm, an aluminum foil 2 having a thickness of 50 μm is cut into a 4 mm square, a 3 mmφ hole is formed in the center, and the copper plate 1 is used. The aluminum foil 2 was caulked with a SUS screw 3 and a nut 4 so that the aluminum foil 2 was partially exposed and fixed tightly on the copper plate 1. Thereafter, the coating material prepared in Example 5 and Comparative Example 5-2 was applied so as to completely cover the screws 3, nuts 4, aluminum foil 2, and copper plate 1, air-dried at room temperature for 30 minutes, and then dried at 80° C. for 4 hours. Let After that, saline solution 6 (50 g/L) was dropped on the coating film 5, and the condition of the interface 7 between the aluminum foil 2 and the copper plate 1 was visually confirmed after maintaining for 4 days at 35° C. and 90% RT. The results are shown in Table 12. The criteria in Table 12 are that the surfaces of the aluminum foil and the copper plate to which the saline solution was dropped are not changed, ◯ is partially rusted, and × is rusted entirely.

Dissimilar metal bonding (FC200-aluminum foil)
Further, the appearance evaluation of dissimilar metal bonding was performed in the same manner as in the case of the copper plate-aluminum foil except that FC200 was used instead of the copper plate. The results are shown in Table 13.

1: Copper plate 2: Aluminum foil 3: Screw 4: Nut 5: Coating film 6: Saline solution 7: Interface A1: First core wire B1: Second core wire C1: Coating film D1: Dissimilar metal joint A2: First pipe B2 : Second pipe C2: Coating film D2: Dissimilar metal joint

Claims (12)

A rust-preventive coating material comprising a fluorine-containing copolymer containing a fluorine-containing olefin unit and a vinyl alcohol unit, wherein the fluorine-containing copolymer has characteristics (a) to (c).
Characteristic (a): Water vapor permeability per 100 μm is 25 g/m ² ·day or less Characteristic (b): Oxygen permeability coefficient is 2.0E-13 cc·cm/cm ² ·sec·cmHg or less Characteristic (c): Water absorption rate Is 10 mass% or less The rust preventive coating composition according to claim 1, wherein the fluorine-containing copolymer has a converted haze value of 3.0 or less per 30 μm. The rust preventive coating composition according to claim 1 or 2, wherein the fluorine-containing copolymer has a hydroxyl value of 400 mgKOH/g or more. The anticorrosive paint according to claim 1, 2 or 3, which is for joining dissimilar metals. The rust preventive paint according to claim 4, wherein the dissimilar metal joint is a dissimilar metal joint of an electric wire or a pipe. The dissimilar metals are aluminum or aluminum alloy and copper, aluminum or aluminum alloy and iron, aluminum or aluminum alloy and zinc, aluminum or aluminum alloy and nickel, aluminum or aluminum alloy and tin, copper and iron, copper and zinc, copper and nickel. Or the anticorrosive paint according to claim 4 or 5, which is copper and tin. The anticorrosive paint according to claim 1, 2, 3, 4, 5 or 6, which is for steel plate, cast iron, high temperature and high pressure cast steel, or aluminum-zinc alloy plated steel plate. The anticorrosive paint according to claim 1, 2, 3, 4, 5, 6 or 7, further comprising a curing agent. The rust-preventive coating material according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the fluorine-containing copolymer has solubility in an alcohol solvent. The anticorrosive paint according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, further comprising a solvent. A coating film formed from the anticorrosive paint according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. A laminate comprising a metal base material and the coating film according to claim 11.

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