JPS599585B2 - Corrosion-resistant paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of forming a strong coating with excellent physical properties, especially corrosion resistance, on metal surfaces such as steel and castings.
The present invention relates to a corrosion-resistant paint composition.

BACKGROUND ART Conventionally, resin coatings (linings) for the purpose of corrosion and rust prevention of metals have been widely applied to various pollution control devices, chemical equipment, tanks, oil tanks of ships, ship bottoms, etc.

By the way, as the resin used for these resin linings, unsaturated polyester resins or epoxy resins are used from the viewpoints of permanent hardening, on-site workability, cost, etc., and the lining method is FRP lining, that is, lining. At the time of construction, an amine crosslinking agent is mixed in advance for epoxy resins, and an organic peroxide is mixed as a crosslinking initiator for unsaturated polyester resins, and a sheet or woven base material made of glass fiber is mixed. It was common practice to apply the resin to the matrix to be lined, impregnate it with the resin using a felt roll or the like, and simultaneously defoam it and cure it. In addition to this method, a method that has recently attracted attention is a composition in which extremely thin glass flakes are blended with the above-mentioned epoxy resin or unsaturated polyester resin instead of glass fibers, and are applied to the object by spray painting. Some methods have already been put into practical use, such as spraying or applying the coating to the object using a core (flake lining). For example, such compositions include protective and decorative coating compositions containing fine glass flakes in an organic resin binder vehicle (Japanese Patent Publication No. 51-25368), or lining resins. A lining material filled with glass flakes as a corrosion-resistant material and glass fiber as a reinforcing material (Japanese Patent Laid-Open No. 5
2-30855), and the surface of flaky glass is further treated with an appropriate substance to give it hydrophobicity and leafing properties, and this is mixed into plastics, paints, and insulation. Paper etc. (Japanese Patent Publication No. 47-16821) are also known. However, when applying the above-mentioned composition, it is usually necessary to take into consideration various performance aspects of the coating, and all 2U coatings are used.
It is an ultra-thick film of 1 or more. Moreover, the construction cost is very high, and therefore it cannot be applied to ordinary steel structures, and is actually used for very limited special purposes as mentioned above. Further, although the coating obtained by the above-mentioned FRP lining method is physically strong, the construction method is similarly difficult and the construction cost is high.

Therefore, in order to improve the shortcomings of these lining methods,
Currently, the method that is widely used is a method that uses a mixture of extremely thin glass flakes and resin, which is relatively simple compared to conventional lining methods such as one-shot painting or troweling. On the other hand,
The unavoidable drawback is that the physical properties of the resulting coating film are poor. The present invention relates to a corrosion-resistant coating composition that can overcome the various drawbacks of the prior art as described above and provide a durable coating with excellent corrosion resistance, adhesion, impact resistance, etc.

That is, the present invention provides (1) 5 to 15 parts of flat polyethylene fine powder or polyacetal fine powder to 100 parts by weight of a resin composition consisting of an epoxy resin or unsaturated polyester resin and a curing agent.
0 parts by weight of a corrosion-resistant coating composition prepared by mixing a necessary amount of solvent, and (2) 100 parts by weight of a resin composition consisting of an epoxy resin or unsaturated polyester resin and a curing agent, flat polyethylene. The present invention relates to a corrosion-resistant paint composition prepared by mixing 5 to 100 parts by weight of a fine powder or a fine polyacetal powder, 5 to 150 parts by weight of a rust-preventing pigment, and, if necessary, a required amount of a solvent.

The "resin composition" used in the present invention refers to an epoxy resin or unsaturated polyester resin and a curing agent (crosslinked) that can react with the reactive groups contained in the molecules of the resin to form a crosslinked structure. It consists of a mixture with an agent or a catalyst for initiating and promoting the formation reaction of a crosslinked structure.

The epoxy resin used in the present invention is a resin having at least two or more epoxy groups in one molecule, such as (1) one synthesized by the reaction of bisphenol A and epichlorohydrin or methylepichlorohydrin; 2) Glycols and epichlorohydrin) synthesized by reacting with fluoride or methylepichlorohydrin; (3) Novolaks or resols obtained by reacting phenols and formaldehyde under acidic or alkaline catalysts with epichlorohydrin or methylepichlorohydrin. (4) those synthesized by oxidizing intramolecular double bonds, (5) those obtained by reacting halogenated phenols with epichlorohydrin or methylepichlorohydrin, (6) ) Those obtained by reacting phenols with ethylene oxide or propylene oxide, etc., and epichlorohydrin or methylepichlorohydrin, (7) Those obtained by reacting carboxylic acids with epichlorohydrin or methylepichlorohydrin, etc. can be mentioned.

These can be used alone or as a mixture.

Furthermore, it should be noted that epoxy compounds and derivatives of the above-mentioned epoxy resins that can be easily inferred from these compositions are also included within the scope of the present invention.

Examples thereof include polyol-type epoxy resins, alicyclic epoxy resins, halogen-containing epoxy resins, and the like.
Listed as the product names of commercially available products, for example, Epicote (trade name manufactured by Ciel Chemical Co., Ltd.), Epiclon (trade name)
Typical examples include Dainippon Ink & Chemicals (trade name) and Araldite (Ciba Kirkey (trade name)). As the curing agent for these epoxy resins, any curing agent that is generally used as a curing agent for epoxy resins may be used. For example, aliphatic or aromatic polyamines such as diethylenetriamine, triethylenetetramine, metaxylylenediamine, metaphenylenediamine, heterocyclic diamine, secondary polyamines such as dimethylaminomethylphenol, tris(dimethylaminomethyl)phenol, piperidine, etc.
or tertiary amines, polyamide resins, amino compounds such as amine adducts (generally referred to as amine adducts), thiols, thiols, isocyanate compounds such as tolylene diisocyanate and hexamethylene diisocyanate (including block isocyanates) ), phenolic resins, acid anhydrides, melamine resins, urea resins, etc. Those that require heating above the thermal deformation temperature of the flat plastic fine powder during the curing reaction of the tossing resin composition are naturally excluded from the scope of the present invention. In addition, since the composition of the present invention is generally applied to large steel materials and large steel products, the use of a resin composition consisting of a combination of an epoxy resin and a curing agent in which a chemical reaction proceeds under constant drying or tough drying. is preferred. In the resin composition of the present invention comprising an epoxy resin and a curing agent, there is no particular need to use a solvent when the epoxy resin and curing agent are liquid at room temperature.

However, if either one of them is solid at room temperature, it is preferable to use it by dissolving it in the required amount of one or more of the solvents described below, as is usually done. Further, as the unsaturated polyester resin used in the present invention, all known ones can be equally used.

The synthesis method includes, for example, carrying out an esterification reaction with a polyhydric alcohol in an inert gas using a combination of an unsaturated acid and a saturated acid, and then diluting with a solvent or a polymerizable monomer. The unsaturated acids and saturated acids include maleic anhydride, fumaric acid, citraconic acid, itaconic acid, tetrachlorophthalic anhydride, head acid, tetrabromo phthalic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and endomethylenetetrahydro anhydride. Examples include phthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, and anthracene monomaleic anhydride adduct. These may be used alone or in mixtures. Further, the polyhydric alcohols to be reacted with the saturated and unsaturated acids include ethylene glycol, diethylene glycol, triethylene glycol,
Propylene glycol, dipropylene glycol, butanediol-1,3, butanediol-1,4, butanediol-2,3, pentanediol-1,5, hexanediol-1,6, neopentyl glycol, 2,2,
4-trimethylpentanediol-1,3, hydrogenated bisphenol A, glycerin, pentaerythritol, diallyl ether, trimethylene glycol, 2-ethyl-1,3 hexanediol, trimethylolpropane,
Cyclohexane dimethanol-1,4,2,2,4-tetramethylcyclobutanedio→re-1,3,1,4-bis(2-oxyethoxy)benzene, 2,2,4,4-
Includes tetramethylcyclobutanediol-1,3 and the like. These may be used alone or in mixtures. In addition, in the presence of a reaction catalyst, a solvent, and if necessary a polymerization inhibitor,
The present invention also includes a polyester resin obtained by reacting an epoxy resin with an α,β-monoethylenically unsaturated monocarboxylic acid.

As the epoxy resin, any of the types of epoxy resins described above can be used. In addition, examples of unsaturated monocarboxylic acids that react with the epoxy resin include acrylic acid,
Examples include methacrylic acid and crotonic acid, and monoesters of unsaturated polycarboxylic acids, such as maleic acid monoester, can also be used.

These can be used alone or as a mixture. Examples of the reaction catalyst include amines such as triethylamine, quaternary ammonium salts such as tetramethylammonium chloride, and the like.

Further, as a polymerization inhibitor, for example, hydroquinone, mono-t-butylhydroquinone, pt-butylcatechol, 2-5-di-t-butylhydroquinone, benzoquinone, 2,5-diphenylene, etc. Examples of the monomer include styrene, vinyltoluene, divinylbenzene, vinyl acetate, methacrylic acid, methyl methacrylate, acrylic acid, ethyl acrylate, acrylonitrile, methacrylic nitrile, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, Examples include diethylene glycol bisallyl carbonate, diallyl phthalate, 2,5-dichlorostyrene, diallyl ether, triallyl cyanurate, 4-vinylcyclohexanone monoepoxide, vinylpyrrolidone, triallylphosphate, and the like.

These can be used alone or as a mixture.

Unsaturated polyester resins are commercially available and commonly used as mixtures of unsaturated polyesters and polymerizable monomers such as those described above, and these can be used without any problem in the present invention, but if necessary, one or two of the solvents described below may be used. A required amount of seeds or more may be added and mixed. The unsaturated polyester resin of the present invention is prepared using a curing agent (polymerization initiator, polymerization accelerator, etc.) in a conventional manner.

As the polymerization initiator, common peroxides and the like can be used. For example, methyl ethyl ketone peroxide, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxy\xane, benzoyl peroxide Peroxides such as or t
-Butyl peroxyphthalate, t-butyl peroxybenzoate, t-butyl peroxylaurate, t-
One type or a mixture of two or more types of peroxy esters such as butyl peroxy 2-ethylhexanoate, t-butyl peroxy bivalate, t-butyl peroxy acetate, t-butyl peroxy isobutyrate, etc. Can be used. Furthermore, if necessary, one or more polymerization accelerators such as amines, fatty acid metal salts such as cobalt naphthenate, manganese naphthenate, and lead naphthenate may be added. The amount of the polymerization initiator and polymerization accelerator added to the unsaturated polyester resin of the present invention is 0.1 to 10 parts by weight of the polymerization initiator per 100 parts by weight of the unsaturated polyester resin (including the polymerizable monomer); Polymerization accelerator 0.1-10
The ratio of parts by weight can be used as a preferable range.

In the present invention, the solvents used as necessary include, for example, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, alcohol solvents, ketone solvents, ester solvents, and ether solvents. , ketone alcohol solvents, ether alcohol solvents, ketone ether solvents, ketone ester solvents, ester ether solvents, and the like.

These can be used alone or as a mixture.

These solvents are used in terms of composition viscosity, coating workability, etc.
Use in the amounts normally used. The flat polyethylene fine powder or polyacetal fine powder used in the present invention is obtained by turning polyethylene or polyacetal into flat fine powder (hereinafter simply or as necessary, referred to as flat plastic fine powder) by chemical or physical means. , average thickness 50 microns or less, preferably 1 to 2
It has a flat shape with an average length of 0 microns and an average length of 1000 microns or less, preferably about 50 to 500 microns.

Previously, flat glass fine powder,
Coating compositions incorporating so-called glass flakes are known.

However, although the coating obtained from the coating composition has a great effect of blocking the permeation of corrosive factors due to the lamination of glass flakes, the biggest drawback is that the glass itself lacks elasticity, so the expansion and contraction rate of the obtained coating is extremely low. It had the disadvantage of being small. In addition, the above-mentioned coating composition is used by coating it in a thicker film than ordinary coating compositions, and the thicker the film, the more difficult it is to prevent the coating from bending, deforming, etc. However, it has the disadvantage that it cannot adapt to the film and is prone to film breakage, peeling, etc. The flat plastic fine powder of the present invention is mainly used to improve the stiffness.

In other words, the lamination effect in the film and the effect of improving the elasticity of the film are the main factors. The flat plastic fine powder of the present invention has a specific shape as described above.
The thickness is preferably as thin as possible from the viewpoint of increasing the number of overlapping layers of fine plastic powder, and the thickness is approximately 50 microns or less.

When the thickness is about 50 microns or more, especially when the coating is thin, there are fewer overlapping layers of fine plastic powder.
The blocking effect of corrosive factors is significantly reduced. On the other hand, if the length of the plastic fine powder exceeds 1000 microns, it is not preferable because the fine powder may bend in the coating, or it may be difficult to form a uniform overlapping layer.

In the present invention, the amount of the flat plastic fine powder to be added to 100 parts by weight of the resin composition (solid content, polymerizable monomers are calculated as solid content) is when the flat plastic fine powder is used alone. is 5 to 150 parts by weight, preferably 10 to 80 parts by weight. If the amount of the fine powder in the above ratio is less than 5 parts by weight, the effect of preventing the permeation and penetration of steam and moisture and other corrosive factors cannot be obtained. Also 15
If the amount is more than 0 parts by weight, there will be a drawback that pinholes will occur more frequently. Incidentally, when the flat plastic fine powder is used together with the anticorrosion pigment, it is used in a proportion of 5 to 100 parts by weight, preferably 10 to 60 parts by weight. When the amount of flat plastic fine powder is less than 5 parts by weight and 100 parts by weight
Defects when the amount exceeds parts by weight are the same as those described above. In general, the "rust-preventing pigment" used in another aspect of the present invention may be any pigment that is easily available on the market. For example, representative examples thereof include red lead, lead zinc oxide, lead cyanamide, etc. , basic chromate, metallic lead, metallic lead powder and lead compounds such as flat metallic lead, strontium chromate,
Calcium chromate, zinc chromate, zinc molybdate, calcium molybdate, zinc tungstate, calcium tungstate, magnesium tungstate, lead chromate, zinc phosphate, aluminum phosphate,
Oxygen acid salts such as tin orthophosphate, zinc tetraborate, zinc metaborate, flat aluminum powder, metallic zinc powder,
It is one type or a mixture of two or more types of flat metal zinc powder.

The amount of the anticorrosive pigment added to the anticorrosive coating composition is 5 to 150 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the resin composition.

In the above, if the amount of the rust preventive pigment is less than 5 parts by weight, there is no rust preventive effect. On the other hand, if the amount is more than 150 parts by weight, pinholes will occur significantly in the coating, the physical properties of the coating will deteriorate, and the desired effect will not be obtained. Normally, thick film type coatings are prone to pinholes due to poor coating methods, management, curing, etc. That is, originally, this type of coating itself has almost no anti-corrosion effect, and the presence or absence of initial pinholes determines the subsequent durability of the coating. However, at the actual level of polishing, it is difficult to completely eliminate pinholes in the coating. The presence of anticorrosion pigments in the composition, as in the above embodiments of the invention, therefore has the advantage of acting very effectively against the penetration of corrosive agents. Furthermore, among the above-mentioned anti-rust pigments,
It is most preferable to use flat zinc powder, flat metallic lead powder, and flat aluminum powder, which have both a rust-preventing effect and the property of forming multiple overlapping layers.

Furthermore, it is possible to add coloring pigments, extender pigments, suspending agents, dispersants, other flat pigments, etc. to the anticorrosive coating composition of the present invention, if necessary.

The composition of the present invention thus obtained can be applied by brush, roller,
It is applied to the surface of the target steel material by a conventional method such as airless spraying or air spraying to a film thickness of 5 ml or less, preferably a minimum film thickness of about 300 microns or more, and then dried at room temperature or by forced drying. The film obtained after drying has excellent physical properties and corrosion resistance. Hereinafter, specific effects of the present invention will be explained using examples.

Note that "parts" or "%" in Examples and Comparative Examples indicate "parts by weight" or "% by weight." [1] Creation of flat polyethylene fine powder Melt index 0.5g/10m1!11 Density 0.
After 960 polyethylene was formed into a film using a stretched film manufacturing apparatus, the film was cooled to -160 DEG C. in liquid nitrogen, frozen and pulverized, and then sieved through a wire mesh.

The obtained fine powder has a thickness of 5 to 18 microns, a length of 50 microns or less (15%), a length of 50 to 500 microns (68%), and a length of 500 microns or less.
It was a flat fine powder with a particle size distribution of 17% of microns or more.

(Hereinafter, simply referred to as polyethylene) [Creation of old flat polyacetal resin fine powder] Polyacetal resin with a specific gravity of 1.42, melting point of 175°C, and fluidity of 18'C is formed into a film using a stretched film manufacturing device, and then The film was cooled to -160°C under nitrogen, cryo-ground and then sieved through a wire mesh.

The obtained fine powder was a flat fine powder having a particle size distribution of 4 to 16 microns in thickness, 8% in length of 50 microns or less, 62% in 50 to 500 microns, and 500 microns or more (2001).

(hereinafter simply referred to as polyacetal) Example 1 A corrosion-resistant coating composition of the present invention having the composition shown in Table 1 and a coating composition other than the present invention for comparison were prepared.

150×50×1.6W! l mild steel plate (JIS-G-3
141) by grid blasting to remove mill scale, rust,
After completely removing the oil, the composition was applied by air spray to a dry film thickness of 500 ± 20 microns,
It was dried for 7 days at 20° C. and 75 (fl) RH and subjected to various tests.

The results obtained are shown in Table 2. Example 2 100 parts by weight of isophthalic acid unsaturated polyester resin (same as Example 1), organic bentonite (same as Example 1)
3 parts, 10 parts of styrene monomer, cobalt naphthenate (
A composition of Example 2 was obtained by varying the amount of polyacetal added to 100 parts by weight of a resin composition consisting of 1 part (same as in Example 1) and 1 part of methyl ethyl ketone peroxide.

For comparison, glass flakes (
Coating compositions were obtained by varying the amount of the coating material (average length: 150 to 200 microns, average thickness: 3 to 5 microns). Using the obtained compositions of Examples and Comparative Examples, test pieces with a thickness of 500 ± 10 microns, a width of 10 m, and a length of 100 mm were created,
The coating film obtained by drying for 7 days at 20° C. and 75% RH was subjected to an elongation measurement test according to the method of JIS-K-7115. The results were as shown in Figure 1. The elongation rate ratio is expressed as an elongation rate ratio when the elongation rate of only the resin composition is set to 1. Example 3 A polyamide resin consisting of a linear bisphenol type epoxy resin having an epoxy equivalent of 184 to 194 and an aromatic amine having an active hydrogen equivalent of 80 as a hardening agent was used to mix the epoxy resin and the hardening agent in an equivalent ratio. A coating composition having the composition shown in Table 3 was prepared using the epoxy resin composition.

For comparison, paints other than those of the present invention were also prepared. 150×50
After completely removing mill scale, rust, and oil from a mild steel plate (JIS-G-3141) with a diameter of 1.6 mm, the composition was air-sprayed to a dry film thickness of 50 mm.
Painted to 0 ± 20 microns, 20℃, 75%
It was dried under RH conditions for 7 days and subjected to various tests.

As can be seen from the comparative test results Tables 2 and 4 and FIG. 1, it is clear that the coatings obtained from the anticorrosive coating composition of the present invention were very excellent in both physical properties and corrosion resistance.

[Brief explanation of the drawing]

FIG. 1 shows the amount of polyacetal or glass flakes added and the elongation ratio of the coating.

Claims (1)

[Claims] 1. 5 to 150 parts by weight of flat polyethylene fine powder or polyacetal fine powder per 100 parts by weight of a resin composition consisting of an epoxy resin or unsaturated polyester resin and a curing agent.
A corrosion-resistant coating composition prepared by mixing parts by weight and, if necessary, a necessary amount of a solvent. 2. The anticorrosive coating composition according to claim 1, wherein the flat polyethylene fine powder or polyacetal fine powder is flat with an average thickness of 50 microns or less and an average length of 1000 microns or less. 3. 5 to 100 parts by weight of flat polyethylene fine powder or polyacetal fine powder, 5 to 150 parts by weight of anticorrosive pigment, and as necessary for 100 parts by weight of the resin composition consisting of epoxy resin or unsaturated polyester resin and curing agent. A corrosion-resistant paint composition prepared by mixing the required amount of solvent. 4. The anticorrosive coating composition according to claim 3, wherein the flat polyethylene fine powder or polyacetal fine powder is flat with an average thickness of 50 microns or less and an average length of 1000 microns or less. 5. The anticorrosive paint composition according to claim 3, wherein the anticorrosive pigment is a flat metal powder.