JPS6042262B2 - Corrosion prevention method for metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing corrosion of metal, which can reduce the number of coatings and form a coating layer with excellent durability.

Various paints have been applied to various metals, mainly steel, for the purpose of protecting them.

However, with the recent environmental pollution such as air pollution, the number of corrosive factors has been increasing, and in order to cope with this, there is an increasing demand for a more durable corrosion prevention method. Currently, various synthetic resin paints such as zinc-rich paints, epoxy resin paints, vinyl resin paints, urethane resin paints, chlorinated rubber paints, unsaturated polyester resin paints, silicone resin paints, and ferre resin paints are currently available. Coating systems based on one type or a combination thereof have been developed and used.

On the other hand, it has excellent painting workability, low-pollution thinner can be used, and the degree of surface treatment of the object to be coated, which requires a lot of cost and number of steps during the painting process, can be relatively rough. Vegetable oils, phthalate resins, or so-called oil-based or phthalate resin paints that are a mixture of these have been used for a long time, and have advantages that other synthetic resin paints cannot obtain, such as relatively low paint costs. Used and has actual results.

It is generally said that the durability of metal corrosion protection by a paint film is roughly proportional to the paint film thickness, but the oil-based or phthalate resin paints can only be applied in a single coat of about 40 microns, so they are not suitable for metal protection. In order to obtain the required specified film thickness, multiple coats, 4 to 5 times, were required.

Oil-based paints or phthalate resin paints absorb oxygen in the air after application and become a hardened film through an oxidative polymerization reaction, so the hardening of the paint film starts from the surface of the paint film that is in direct contact with the air and gradually progresses. Proceeds into the paint film.

In this case, if the coating film is too thick, only the surface layer will harden.
Curing of the deep parts of the coating film will be extremely delayed. the result,
There is a large difference in the degree of hardening between the surface and the inside of the paint film, and the surface of the paint film becomes wrinkled, making it impossible to obtain the desired corrosion-proofing effect and aesthetic finish of the paint film. Particularly in paints that use flat pigments, such as aluminum paints, in which the pigments are arranged in layers on the surface of the paint film, the supply of oxygen to the inside of the paint film is insufficient, resulting in the above-mentioned tendency. becomes more pronounced. For the reasons mentioned above, oil-based or phthalate. It was not possible to achieve a film thickness of 140 to 160 microns, which is necessary for metal protection, with a single coat of resin paint.

On the other hand, it is generally said that the cost of painting is about three times the cost of paint, and therefore, from the viewpoint of not only the cost of refurbishment but also the shortening of the painting period, it is possible to achieve a coating of 100 microns or more in one coat. At present, there is a strong desire for a corrosion prevention method using oil-based or phthalic acid resin paints that can be coated.

The present invention has been made in view of the above points, and includes:
It can be applied thickly in one coat without sacrificing the advantages of oil-based resin paints or phthalate resin paints, such as ease of painting workability and ease of surface treatment, and is effective against drying defects inside the paint film and on the surface of the paint film. The object of the present invention is to provide a corrosion prevention method capable of forming a coating layer that exhibits a positive coating appearance and anticorrosion performance without causing wrinkles, and has poor durability.

That is, the present invention provides: 1) (1) 9 vegetable oil and/or phthalic acid resin 99.92-60 on the metal surface;
% by weight and a mixture consisting of 0.1 to 40% by weight of tricyclo[5,2,1,σ,6]deca-4-ene-ethyloxymethyl methacrylate...10 parts by weight, and 35 phosphoric acid, boric acid, Oxylate containing at least one salt obtained from molybdic acid, chromic acid, and zinc, lead, or aluminum; metallic lead; at least one of zinc oxide, lead monoxide, lead dioxide, or tri-lead tetroxide; Three oxides of metal lead, which are seeds; white lead, lead cyanamide, calcium leadate,
A pigment consisting of at least one rust preventive pigment selected from the group consisting of at least one salt of metallic lead such as basic lead sulfate and basic lead chromate, and if necessary, an extender pigment.
4. A step of applying one layer of a pigment composition containing 1 to 50 parts by weight so that the average dry film thickness becomes 50 to 200 microns and drying to obtain a corrosion-resistant coating layer, and 1) On the surface of the corrosion-resistant coating layer, 4 (a) 99.9 to 6 weight percent of a mixture of vegetable oil and (1) at least one resin selected from ferer resin, petroleum resin, and coumaron resin, and tricyclo [5, 2, 1,
σ, 6] A mixture consisting of 0.1 to 4 weight percent of deca-4-ene-ethyloxymethyl methacrylate ... 10 weight parts, and an oblate pigment having 5 metal options...
A coating composition containing 1 to 30 parts by weight has an average dry film thickness of 3
A metal corrosion prevention method including the steps of applying one layer to a thickness of 0 to 150 microns and drying to obtain a protective coating layer; 99.9 to 6% of a mixture with at least one resin selected from ferer resin, petroleum resin, and coumaron resin, and tricyclo[5,2,,1
, σ, 6] A mixture consisting of 0.1 to 4% by weight of deca-4-ene-ethyloxymethyl methacrylate...10 parts by weight, and 5 phosphoric acid, boric acid, molybdic acid, chromic acid and zinc, Oxylate salts containing at least one of the salts obtained from lead and aluminum; Metallic lead: oxides of metallic lead containing at least one of lead zinc oxide, lead monoxide, lead dioxide, and trilead tetroxide; At least one rust-preventive pigment selected from the group consisting of a salt of metallic lead, which is at least one of white lead, lead cyanamide, calcium lead acid, basic lead sulfate, and basic lead chromate, and if necessary, the constitution. A step of applying one layer of a coating composition containing 1 to 50 parts of a pigment to have an average dry film thickness of 50 to 200 microns and drying it to obtain a corrosion-resistant coating layer; 1) On the surface of the corrosion-resistant coating layer, 5 (a) vegetable oil and fat) ferer resin, petroleum resin,
99.9 to 6% of a mixture with at least one resin selected from coumarone resins and tricyclo[5,2,1,σ
, 6] A mixture consisting of 0.1 to 4 weight percent of deca-4-ene-ethyloxymethyl methacrylate ... 10 weight parts, and an oblate pigment having 5 metal options...
A coating composition containing 1 to 30 parts by weight has an average dry film thickness of 3
It relates to a method for preventing corrosion of metal, which includes the steps of applying one layer to a thickness of 0 to 150 microns and drying to obtain a protective coating layer.

The vegetable oil used in the present invention is an esterification reaction product of various fatty acids and glycerin.

Examples of the vegetable oils used in the present invention include linseed oil, linseed oil, soybean oil, cottonseed oil, rice bran oil, peanut oil, olive oil, castor oil, coconut oil, rapeseed oil, corn oil, and sesame oil. can be lost.

Among others, when considering the drying properties of the coating film, the iodine value is 120
The drying oils mentioned above, such as linseed oil, soybean oil, and linseed oil, are most preferred. The vegetable oils and fats mentioned above also include blown oils and thermally polymerized oils obtained by slightly oxidizing or polymerizing natural oils.
In addition, the phthalic acid resin used in the present invention is a polyhydric alcohol, a polybasic acid (necessarily also containing a portion of a dibasic acid).
It is a resin with an oil length of about 40 to 80% obtained by esterifying a fatty acid and a fatty acid by a conventional method.

Examples of the polyhydric alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerol, ethylene glycol, propylene glycol, 1,3-butylene glycol, butenediol, neopentyl glycol, diethylene glycol, and dipropylene glycol. Dihydric or higher polyhydric alcohols such as bisphenol dioxyethyl ether, bisphenol dioxypropyl ether, etc. are used.

Examples of the polybasic acids (monobasic acids) include succinic acid, adipic acid, maleic anhydride, maleic acid, fumaric acid, citraconic acid, itaconic acid, benzoic acid, p-tertiarybutylbenzoic acid, and phthalic anhydride. acid, o-phthalic acid,
m-phthalic acid, p-phthalic acid, tetrahydrogenated phthalic anhydride,
Monobasic or polybasic acids such as tetrachlorophthalic anhydride, head acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, or their anhydrides are used.

Particularly preferred are systems in which phthalic acid alone or phthalic anhydride is used as the main component in combination with other acid components. Further, the fatty acids include, for example, linseed oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, cottonseed oil fatty acid, rice bran oil fatty acid, peanut oil fatty acid, olive oil fatty acid, castor oil fatty acid, coconut oil fatty acid, palm oil fatty acid, etc. It will be done.

In the coating composition used to obtain the corrosion-resistant coating layer in aspect (1) of the present invention, the vegetable oil or phthalic acid resin may be used alone, or both may be used in any proportion. May be used in combination.

In the above, when the phthalic acid resin is used alone, the phthalic anhydride content is preferably 3% by weight or less, more preferably 25% by weight or less, and when used in combination with vegetable oil, It is preferable to adjust the mixing ratio so that the phthalic anhydride content in the mixture is 3% by weight or less, more preferably 25% by weight or less.

In the present invention, the phthalic anhydride content in the phthalic acid resin or the mixture of vegetable oil and phthalic acid resin is 3.
If the amount exceeds the saliva amount %, it becomes difficult to obtain the thick film drying effect by adding the tricyclodecene derivative described later, and it also causes deterioration of the physical properties of the coating film, which is not very preferable.

Tricyclo[5,2,1,CP,6 used in the present invention
] Deca-4-ene-ethyloxymethyl methacrylate (
The tricyclodecene derivative (hereinafter referred to as tricyclodecene derivative) is represented by the following structural formula.

In aspect (1) of the present invention, the mixing ratio of the vegetable oil and/or phthalic acid resin and the tricyclodecene derivative is preferably 99.9 to 6% by volume of the former. ~8 plow weight%
, the latter is 0.1 to 4 weight%, preferably 2 to 2
The weight is %. In the above, if the amount of the tricyclodecene derivative is less than 0.1% by weight, the effect will not be obtained at all,
On the other hand, if it exceeds 4% by weight, the physical properties of the coating film will be significantly reduced, and the cost of the coating will increase, reducing its value as an industrial product. Further, the phenolic resin used in the present invention is obtained by reacting a phenol having an alkyl, aryl, or aralkyl substituent at a distal or ortho position with formaldehyde.

The phenols include baracresol, paraethylphenol, paratersiabutylphenol, paratersialyamylphenol, paraphenylphenol,
Valacyclohexylphenol, bisphenol A, etc. are commonly used. The use of the phenolic resin has the effect of significantly improving the durability of the coating film. Petroleum resins used in the present invention are aliphatic hydrocarbons and aromatic hydrocarbons having C4 to C9 unsaturated groups distilled out during petroleum refining, reactions in the petrochemical industry, and decomposition processes.
Softening point obtained by polymerizing alicyclic hydrocarbons: 80 to 150
°C resins and derivatives obtained therefrom. The coumaron resin used in the present invention is obtained by copolymerizing coumaron, indene, styrene, etc. contained in solvent naphtha, which is contained in light oil in coke oven gas, and has a softening point of 80 to 150°C. This resin is commonly called coumaron-indene resin.

The petroleum resin and coumaron resin are effective in facilitating brush coating workability and imparting uniformity to the coating film when the composition of the present invention is applied with a brush. In the present invention, the mixing ratio of vegetable oil and at least one resin selected from phenolic resins, petroleum resins, and coumaron resins is such that the former is 40-9% by volume and the latter is 60-1% by volume. Preferably 50-7
The amount of saliva is 50-3% relative to the amount of breath.

Among the combinations of the present invention, in consideration of the durability of the coating film and the uniformity of the film thickness, the combination of vegetable oil, phenol resin, and petroleum resin is most preferable, and the preferred ratio of each is as follows:
The amount of vegetable oil and fat is 50-7% by volume, 35-2% by volume of phenol resin, and 15-1% by volume of petroleum resin. In the present invention (
b) The mixture of vegetable oil and resin selected from at least one of phenol resin, petroleum resin, and coumaron resin, and the mixture ratio of tricyclodecene derivative is 99% for the former.
．． The latter is 0.1 to 40% by weight, preferably 2 to 2% by weight, relative to 9 to 6% by weight, preferably 8 to 8% by weight. In the above, if the amount of the tricyclodecene derivative is less than 0.1% by weight, the effects of the present invention cannot be obtained at all. On the other hand, if it exceeds 40% by weight, the physical properties of the coating film will be significantly reduced, and the cost of the coating will also increase, reducing its value as an industrial product. The pigment used in the present invention is generally used as a paint pigment, and consists of a rust-preventing pigment and, if necessary, an extender pigment.

The above anti-rust pigments include metallic lead, zinc oxide, lead monoxide,
A lead-based anticorrosive pigment consisting of metallic lead selected from lead dioxide, trilead tetroxide, white lead, lead cyanamide, calcium leadate, basic lead sulfate, and basic lead chromate, and its oxide or salt; chromium acids, obtained from oxyacids such as molybdic acid, phosphoric acid, boric acid, and zinc, lead and aluminium,
For example, zinc chromate, zinc molybdate, lead chromate, zinc phosphate, lead orthophosphate, lead pyrophosphate, lead metaphosphate, aluminum phosphate, lead pyrophosphate, zinc tetraborate, zinc metaborate, lead metaborate, lead borate,
Oxygen acid salt-based anticorrosion pigments such as

Examples of extender pigments include coloring pigments such as iron oxide, titanium dioxide, aluminum powder, yellow lead, carbon black, phthalocyanine blue, and zinc dioxide, calcium carbonate, precipitated barium sulfate, calcium silicate, barium carbonate, talc, Clay, mica, silica, etc. can be used.

In the present invention, thick coating films can be effectively dried by incorporating the rust-preventing pigment into the coating composition as an essential component.

Although the cause (mechanism) is not clear, it is thought that metal ions ionized in the coating film provide a catalytic effect when the tricyclodecene derivative undergoes oxidative polymerization. In the present invention, the pigment is a vegetable oil and/or a phthalic acid resin of 60 to 99%. A mixture consisting of % heel weight and 40 to 0.1% by weight of a tricyclodecene derivative [Aspect (1)], or (a) vegetable oil and fat selected from (a) phenol resin, petroleum resin, and coumaron resin. A mixture consisting of 60 to 99.9% by weight of a mixture with at least one resin and 40 to 0.1% by weight of a tricyclodecene derivative [Aspect (2)] 1 part by weight of each
~50 parts by volume.

In the above range, if the amount of pigment exceeds 50 parts by weight, it is not preferable that the object of the present invention cannot be achieved, and various physical properties of the coating film are deteriorated.

Examples of the flat pigments with metal selectivity used in the present invention include leafing aluminum powder, non-leafing aluminum powder, and mixtures thereof, super foil stainless steel powder, flat zinc powder, flat lead powder, etc. It will be done.

Leafing aluminum powder is the best in terms of paint stability. In the present invention, the flat pigment is a mixture of (a) vegetable oil and (l) at least one resin selected from phenol resin, petroleum resin, and coumaron resin.
0-99. Heel weight% and tricyclodecene derivative 40-0
．． 1 to 30 parts per 10 weight parts of a mixture consisting of 1% by weight
Mix at a ratio of 0 parts by weight. In the above range, if the amount of the flat-shaped pigment having a metal photo-selectivity exceeds 30 parts by weight, it is not preferable because the object of the present invention cannot be achieved, and various physical properties of the coating film are deteriorated.

In the method of the present invention, the composition forming the anti-corrosion coating layer or the protective coating layer involves oxidative polymerization during the drying process of the coating film, so the compositions include cobalt naphthenate, lead naphthenate, manganese naphthenate, calcium naphthenate, It is a matter of course that the product contains so-called metal dryers such as, etc., as well as surface conditioners, anti-sagging agents, anti-settling agents, etc. as necessary.
Anti-skinning agent, surfactant or toluene, xylene,
Naturally, solvents such as mineral spirits, hexane, various naphthas, and nitropropane can also be added.

The method of the present invention involves uniformly mixing and dispersing each of the above-mentioned compositions using a known general manufacturing method such as a dipper, roll mill, sand mill, ball mill, etc., and then adjusting the viscosity to be suitable for the coating machine used with the above-mentioned solvent. , brush on metal surface,
It is coated once using any known coating method such as roller, air spray, airless spray, etc. so that the average dry film thickness is 50 to 200 microns, and is left to dry for a specified period of time to obtain a corrosion-resistant coating layer.

Next, a composition containing the flat pigment with metallic luster of the present invention is applied to the surface of the corrosion-resistant coating layer in the same manner as described above to a dry film thickness of approximately 30 to 150 microns, and under specified conditions. It is dried to obtain a protective coating layer, which forms a laminated film consisting of a corrosion-resistant coating layer and a protective coating layer. Thus, the coating layer obtained by the method of the present invention exhibits excellent effects in both metal corrosion resistance and thick coating drying properties. This product has improved thick film drying properties that could not be obtained with paints, and its effects are significant in terms of resource savings and greatly increased work efficiency.

EXAMPLES The effects of the present invention will be specifically explained below using examples.

In addition, parts or % in Examples and Comparative Examples indicate parts by weight or % by weight. Examples and Comparative Examples Linseed oil (foil oil, iodine value 158
~18 tons viscosity 1.0-1.4 Sp) was used as phthalic acid resin for phthalic acid resin varnish (heating residue 70%, soybean oil modification, phthalic anhydride content 24 ± 2%, oil length 65 ± 2%) , paratarsia butyl phenol resin (softening point 115 to 125 LiC) as a phenolic resin, color number 4 or less, acid value 30 to 40, novolac type), and C5 as a petroleum resin.
Aliphatic hydrocarbon resin obtained from distillate (softening point 125℃
) were used to prepare a coating composition for forming a corrosion-resistant coating layer according to the formulations in Table 1 (Examples of the present invention) and Table 2 (Comparative Examples).

The compositions of the present invention and comparative examples were coated (one coat, dry film thickness 100 microns) at 20° C. and 75% RH. After drying for a while, a corrosion-resistant coating layer was obtained. Next, a coating composition for forming a protective coating layer was prepared according to the formulations of Examples and Comparative Examples in Table 3 using raw materials having the same properties as those used to obtain the coating composition for forming a corrosion-resistant coating layer, and The coating composition for the protective coating layer of the example was coated on the corrosion-resistant coating layer of , and the coating composition for the protective coating layer of the comparative example was coated on the corrosion-resistant coating layer of the comparative example (1 Two coats, dry film thickness 80 microns) at 20°C.
A protective coating layer was obtained by drying for 7 days under 75% RH conditions. After the coating layer of the present invention was obtained, it was immersed in 3% saline and taken out at regular intervals to observe the occurrence of rust and blisters.The results are shown in Table 1. In addition, in the comparative example, the anti-corrosion coating layer was 100 microns in one coat, and the protective coating layer was 8 microns in one coat.
I tried to apply a 0 micron coating, but the surface of the protective coating layer had a lot of wrinkles, and neither the anticorrosion layer nor the protective layer were able to form a normal coating that cured on the inside, so I did not pass the rust prevention test. I was unable to provide it. As is clear from the test results in Table 1 above, according to the method of the present invention, both the anti-corrosion coating layer and the protective coating layer can be coated thickly in one coat, and there is no abnormality as a layered film, and the rust prevention property is improved. It was possible to form an extremely excellent coating layer.

Claims (1)

[Claims] 1 (i) On the metal surface (a) Vegetable oil and/or phthalic acid resin 99.9-6
0% by weight and 0.1% tricyclo[5,2,1,0^2,^6]deca-4-ene-ethyloxymethyl methacrylate
A mixture consisting of ~40% by weight...100 parts by weight, and (b) at least one salt obtained from phosphoric acid, boric acid, molybdic acid, chromic acid, and zinc, lead, or aluminum. Oxylate; Metallic lead; Oxide of metallic lead, which is at least one of lead zinc oxide, lead monoxide, lead dioxide, and trilead tetroxide; white lead, lead cyanamide, calcium leadate, basic lead sulfate, A pigment consisting of at least one rust-preventing pigment selected from the group consisting of salts of metallic lead, which is at least one type of basic lead chromate, and, if necessary, an extender pigment...1-500
Parts by weight of a coating composition containing: (1) coating the surface of the corrosion-resistant coating layer ( a) 99.9 to 60% by weight of a mixture of (a) vegetable oil and (b) at least one resin selected from ferer resin, petroleum resin, and coumaron resin, and tricyclo[5.2
, 1,0^2,^6] A mixture consisting of 0.1 to 40% by weight of deca-4-ene-ethyloxymethyl methacrylate.
...100 parts by weight, and (b) 1 to 300 parts by weight of an oblate pigment with metal photo-selectivity, such that the average dry film thickness is 30 to 150 microns. A method for preventing corrosion of metals, which includes the steps of applying a single layer of paint and drying it to obtain a protective coating layer. 2. Claim 1, wherein the phthalic acid resin has an oil length of 40 to 80% and a phthalic anhydride content of 25% by weight or less.
Corrosion prevention method for metals described in Section 1. 3. The method for preventing corrosion of metal according to claim 1, wherein the vegetable oil is at least one selected from the group consisting of linseed oil, soybean oil, and linseed oil. 4. The method for preventing corrosion of metal according to claim 1, wherein the ferer resin is a paratertiary butyl ferer resin. 5. The method for preventing corrosion of metal according to claim 1, wherein the petroleum resin is an aliphatic hydrocarbon resin obtained from C_5 fraction. 6 (i) 99.9 to 60% by weight of a mixture of (a) (a) vegetable oil and (b) at least one resin selected from ferer resin, petroleum resin, and coumaron resin on the metal surface; Tricyclo [5, 2
, 1,0^2,^6] A mixture consisting of 0.1 to 40% by weight of deca-4-ene-ethyloxymethyl methacrylate.
...100 parts by weight, and (b) at least one oxyacid salt obtained from phosphoric acid, boric acid, molybdic acid, chromic acid, and zinc, lead, or aluminum; metallic lead; Metallic lead oxides, which are at least one of lead oxide, lead monoxide, lead dioxide, and trilead tetroxide; at least one of lead white, cyanamide lead, calcium lead acid, basic lead sulfate, and basic lead chromate. A paint composition containing, on average, 1 to 500 parts by weight of at least one rust-preventing pigment selected from the group consisting of salts of metal lead and, if necessary, extender pigments. A step of applying one layer to a dry film thickness of 50 to 200 microns and drying to obtain a corrosion-resistant coating layer, and (ii) applying (a) (b) vegetable oil and fat on the surface of the corrosion-resistant coating layer. (b) 99.9 to 60% by weight of a mixture of at least one resin selected from ferer resin, petroleum resin, and coumaron resin, and tricyclo[5,2
, 1,0^2,^6] A mixture consisting of 0.1 to 40% by weight of deca-4-ene-ethyloxymethyl methacrylate.
100 parts by weight of a paint composition containing: , and drying to obtain a protective coating layer. 7. The method for preventing corrosion of metal according to claim 6, wherein the vegetable oil is at least one selected from the group consisting of linseed oil, soybean oil, and linseed oil. 8. The method for preventing corrosion of metal according to claim 6, wherein the ferer resin is a paratertiary butyl ferer resin. 9. The method for preventing corrosion of metal according to claim 6, wherein the petroleum resin is an aliphatic hydrocarbon resin obtained from C_5 fraction.