KR102304804B1 - High anticorrosive aqueous coating solution - Google Patents

Abstract

In one embodiment of the present invention,
A water-soluble rust-preventing coating composition comprising: an acrylic resin; zinc flakes; aluminum flakes; dispersant; anti-rust additive; water-soluble solvents or ionized water; surface modifiers; and a pH adjuster,
The acrylic resin is a polybasic acid, a polyhydric alcohol, and a molecular chain forming a polycondensation structure of an epoxy, and an unsaturated fatty acid and an epoxy resin silane are polycondensed to form a molecular chain forming a structure in which an unsaturated fatty acid and a silane are polycondensed to a polyalcohol. After cooling the polycondensation product, a water-soluble polybasic acid is subjected to an addition reaction to introduce a water-soluble polybasic acid to the molecular side chain to produce a water-soluble epoxy and alkyd resin intermediate, and the water-soluble epoxy and alkyd resin intermediate are heated in a temperature range of 60 to 160 ° C. Provided is a water-soluble rust-preventing coating composition produced by polymerization with at least one radical-reactive acrylic monomer.

Description

High corrosion resistance, water-soluble rust preventive coating solution {HIGH ANTICORROSIVE AQUEOUS COATING SOLUTION}

The present invention relates to a high corrosion-resistance water-soluble rust-preventive coating solution, and more particularly, to a high corrosion-resistance water-soluble rust-preventive coating solution prepared by mixing zinc flakes with an acrylic resin.

Coatings of structures made of metal, particularly ships, automobiles, bridges, marine structures, etc., require corrosion protectiveness in addition to the various functions mentioned above. In particular, in the case of steel, which is most often used as a structural material, corrosion occurs because it is easily oxidized in an atmospheric environment containing moisture. Prevention methods are required and are being studied by many scientists, but the perfect anti-corrosion technology has not been developed and applied.

Currently, the most commonly applied method for corrosion prevention of iron is coating technology. Among various coating materials, organic coating materials have excellent mechanical and chemical properties under various corrosive environmental conditions, can be combined with various materials, and are the most widely used for reasons such as reasonable prices. is being used sparingly.

The corrosion prevention mechanism of the organic coating agent used to prevent corrosion of metal can be divided into three main categories.

The first mechanism is a barrier mechanism that blocks the penetration of moisture or oxygen that can cause metal corrosion by organic coating materials or pigments added to the coating.

The second mechanism is an adhesion mechanism, and in order for moisture and oxygen penetrating into the coating layer to react with the metal, the coating layer must be different from the metal surface. At this time, if the adhesion between the coating layer and the metal surface is excellent, corrosion of the metal does not occur.

Lastly, cathodic protection, which acts as a sacrificial anode when corrosion of the metal to be protected occurs due to the excessive addition of a metal with a very high corrosion tendency such as zinc, to the organic coating material to prevent corrosion of the metal; same electrochemical mechanism.

On the other hand, anticorrosive coatings are largely divided into water-soluble and oil-soluble. Water-soluble products have the advantage of a pleasant and safe working environment because they are less harmful to the human body, fire hazard, and odor, and usefulness can prevent loosening of heat-treated products and reduce utility because the curing conditions are much lower than water-soluble products. There is this.

Oil-soluble products have lower curing conditions than water-soluble products, but by using organic solvents such as the solvent PMA (Propylene glycol monomethyl ether acetate) as the main solvent, there is a risk of fire due to high volatile organic compounds. Also, organic solvents are more expensive than deionized water. Therefore, it becomes a factor in the increase of product price.

Meanwhile, oxides of rare earth metals such as molybdenum, tungsten, zirconium, lanthanum, cerium, neodymium, and yttrium have been mainly used to develop environmentally friendly rust inhibitors. However, most of them are very expensive and insoluble in water, so in order to use them as a water-soluble anticorrosive, a separate process such as completely dissolving them with a special method is required, and the price itself is quite unstable due to the localization of the market.

In addition, most of the anti-rust coatings currently on the market, whether oil-soluble or water-soluble, do not guarantee sufficiently high corrosion resistance as required by the industry.

Therefore, in the present invention, it is intended to provide a water-soluble rust-preventing coating solution that can provide and guarantee sufficient high corrosion resistance as required in the industrial field while satisfying the environmental and economical limiting requirements in the prior art as described above.

In one embodiment of the present invention to achieve the above object,

A water-soluble rust-preventing coating composition comprising: an acrylic resin; zinc flakes; aluminum flakes; dispersant; anti-rust additive; water-soluble solvents or ionized water; surface modifiers; and a pH adjuster,

The acrylic resin is a polybasic acid, a polyhydric alcohol, and a molecular chain forming a polycondensation structure of an epoxy, and an unsaturated fatty acid and an epoxy resin silane are polycondensed so as to have a molecular chain forming a structure in which an unsaturated fatty acid and a silane are polycondensed to a polyhydric alcohol. After cooling the polycondensation product, a water-soluble polybasic acid is subjected to an addition reaction to introduce a water-soluble polybasic acid to the molecular side chain to produce a water-soluble epoxy and alkyd resin intermediate, and the water-soluble epoxy and alkyd resin intermediate are heated in a temperature range of 60 to 160 ° C. Provided is a water-soluble rust-preventing coating composition produced by polymerization with at least one radical-reactive acrylic monomer.

In another embodiment of the present invention, the radical-reactable acrylic monomer provides a water-soluble rust-preventing coating solution comprising methyl methacrylate.

In another embodiment of the present invention, the acrylic resin comprises 10% by weight of methyl methacrylate, 30% by weight of N-butyl methacrylate, 3% by weight of a water-soluble epoxy, 10% by weight of a water-soluble alkyd resin, 1.5 Provided is a water-soluble rust-preventing coating composition comprising silane (methacryl propyl trimethoxysilane, Dow Chemical 6030) in weight % and the remainder of a water-soluble solvent, a neutralizer, and other components.

Materials used as binders in the technical field to which the present invention pertains are mostly composed of inorganic materials such as organic titanate, organic silicate, and organic zirconium by sol-gel, but the high corrosion resistance water-soluble rust preventive coating solution composition according to the present invention is a metal flake ( By developing and grafting a water-dispersible acrylic resin suitable for zinc-aluminum flakes) and determining the composition ratio, corrosion resistance can be significantly improved compared to the prior art.

In addition, since the acrylic water-dispersible resin is synthesized in the presence of acid and ammonia or amine is added to adjust the pH, the stability of the resin, water resistance, and adhesion to corrosion-resistant materials are improved by organic binders, metal flakes, and other additives, not organic-inorganic hybrid components. As it is composed of ingredients, it is a material with advantages such as liquid stability and life extension.

<Production of acrylic resin>

In the present invention

(1) Polybasic acid, polyhydric alcohol, unsaturated fatty acid and epoxy resin are polycondensed so as to consist of molecular chains forming a structure in which polybasic acids, polyhydric alcohols and epoxy are polycondensed and molecular side chains forming a structure in which unsaturated fatty acids are polycondensed to polybasic acids. reacting;

(2) preparing a water-soluble epoxy or alkyd resin intermediate by cooling the polycondensation product and then reacting the polybasic acid as a water-soluble group to introduce a polybasic acid as a water-soluble group into the molecular chain;

(3) polymerizing the water-soluble epoxy and alkyd resin intermediate with at least one radical-reactable acrylic monomer in a temperature range of 60°C to 160°C

Water-soluble epoxy, alkyd hybrid acrylic resin is prepared through

wherein the polybasic acid is isophthalic acid, dimethylisophthalic acid, tert-butylisophthalic acid, phthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, adipic acid, terephthalic acid, sebacic acid , azelaic acid, hymic acid, trimellitic acid, dimethylol propionic acid, benzoic acid, succinic acid, and preferably at least one selected from the group consisting of succinic anhydride.

In addition, the polyhydric alcohol is neopentyl glycol, diethylene glycol, dipropylene glycol, propylene glycol, ethylene glycol, 1,6-hexanediol, hexylene glycol, pentanediol, 1,3-butylene glycol, 1,4- At least one selected from the group consisting of butylene glycol, glycerin, triethylene glycol, pentaerythritol, trimethylolpropane, trimethylolethane, and 1,4-cyclohexanedimethanol is preferable.

In addition, the unsaturated fatty acid is preferably at least one selected from the group consisting of soybean oil fatty acid, dehydrated castor oil fatty acid, linseed oil fatty acid, tall oil fatty acid, tung oil fatty acid, safflower oil fatty acid, and sunflower oil fatty acid.

In addition, the epoxy resin is preferably selected as having a polyfunctional water-soluble skeleton, specific gravity 1.25 to 1.30, water solubility 40 to 95%, and epoxy is 185 to 215. These epoxy resins have the effect of increasing the crosslinking density by increasing the curing speed through ether bonding, and maximizing high gloss, scratch resistance, corrosion resistance, and adhesion to the adherend.

In addition, additives are added to improve corrosion resistance and water resistance. These additives are at least one selected from the group consisting of silane having an amino group, silane having an epoxy group, silane having a mercaptan group, silane having an aryl group, and silane having a vinyl group. it is preferable

In addition, acrylic monomers capable of radical reaction include methyl acrylate, ethyl acrylate, styrene monomer, acrylic acid, methacrylic acid, N-butyl acrylate, N-butyl methacrylate, lauryl methacrylate, and I-butyl methacrylic acid. Late, glycidyl methacrylate, 1.6-hexanediol diacrylate, triphenyl glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, selected from the group consisting of alkoxylated tetraacrylate It is preferable that it is 1 or more types.

On the other hand, each has different characteristics and advantages and disadvantages depending on the amount of the acrylic monomer used.

At 50 parts by weight or more of methyl methacrylate, hardness, dryness, chemical resistance, water resistance, corrosion resistance, etc. are good, but adhesion is poor.

At 30 parts by weight or more of N-butyl acrylate, adhesion is good, but water resistance, hardness, etc. are inferior.

At 50 parts by weight or more of methacrylic acid and acrylic acid, solubilization is good, but water resistance and corrosion resistance are not good.

As the water-soluble solvent, one or two or more types of water-soluble solvents such as butyl cellosolve, ethyl cellosolve, N-butanol, methyl cellosolve, methyl ethyl ketone, isopropyl alcohol, glycols, etc. are used. It is preferable to exclude solvents with poor compatibility as much as possible.

As the neutralizing agent, one or two or more kinds of neutralizing agents such as aqueous ammonia, triethylamine, diethylethanolamine, 2-amino-2-methylpropanol, dimethylethanolamine, and the like may be selected and used.

In addition, water-soluble epoxy and alkyd resin intermediates can be prepared and synthesized according to the present invention, but commercially available products may be used.

In the following preparation examples, as a multifunctional water-soluble epoxy, the domestic brand T&L's 1900E epoxy was used for 160 to 190 products, and ASHLAND's NECOWEL 3016E and 750 grades of ASHLAND of the United States were used as the water-based alkyd resin. Isopro?k alcohol was added to this water-soluble epoxy and alkyd resin, and the temperature was raised to 90° C. to stabilize it, and then an acrylic resin was prepared. In order to control the heat of copolymerization, control the molecular weight of the polymer, and prevent gelation, the monomer is added dropwise to the reactor containing them for 1 to 10 hours to carry out the copolymerization reaction.

A preparation example of the acrylic resin prepared in this way is as follows.

go. Preparation Example 1

An acrylic resin was prepared from 40 wt% of methacrylate, 3 wt% of a water-soluble epoxy, 10 wt% of a water-soluble alkyd resin, and the remainder of the water-soluble solvent, neutralizer, and other components.

me. Preparation 2

An acrylic resin was prepared from 40 wt% of a styrene monomer, 3 wt% of a water-soluble epoxy, 10 wt% of a water-soluble alkyd resin, and the remainder of a water-soluble solvent, neutralizer, and other components.

all. Preparation 3

An acrylic resin was prepared from 40 wt% of N-butyl methacrylate, 3 wt% of a water-soluble epoxy, 10 wt% of a water-soluble alkyd resin, and the remainder of a water-soluble solvent, neutralizer, and other components.

La. Preparation 4

An acrylic resin was prepared from 40 wt% of N-butyl acrylate, 3 wt% of a water-soluble epoxy, 10 wt% of a water-soluble alkyd resin, and the remainder of the water-soluble solvent, neutralizer, and other components.

mind. Preparation 5

An acrylic resin was prepared from 40 wt% of methacrylic acid, 3 wt% of a water-soluble epoxy, 10 wt% of a water-soluble alkyd resin, and the remainder of a water-soluble solvent, neutralizer, and other components.

bar. Preparation 6

An acrylic resin was prepared from 10% by weight of methyl methacrylate, 30% by weight of N-butyl methacrylate, 3% by weight of a water-soluble epoxy, 10% by weight of a water-soluble alkyd resin, and the remainder of a water-soluble solvent, neutralizer, and other components. .

buy. Preparation 7

10% by weight of methyl methacrylate, 30% by weight of N-butylmethacrylate, 3% by weight of water-soluble epoxy, 10% by weight of water-soluble alkyd resin, 1.5% by weight of silane (methacryl propyl trimethoxysilane Dow Chemical) 6030) and the remainder of the water-soluble solvent, neutralizer, and other components to prepare an acrylic resin.

Next, a high corrosion-resistance water-soluble rust-preventive coating solution is prepared by using the thus-prepared arc resin.

As the dispersant used in the following examples, nonionic modified fatty acid derivatives that do not contain aromatics, amines, or alkylphenol ethoxylates may be used.

Modified polysiloxane may be used as the surface modifier.

As the pH adjusting agent, ammonia or triethanolamine may be used, and the pH of the composition may be adjusted within the range of 7 to 9.

go. Example 1

45% by weight of the acrylic resin of Preparation Example 7, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

me. Example 2

50% by weight of the acrylic resin of Preparation Example 7, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 15% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

all. Example 3

40% by weight of the acrylic resin of Preparation Example 7, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 25% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

La. Example 4

45% by weight of the acrylic resin of Preparation Example 7, 30% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 15% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

mind. Example 5

45% by weight of the acrylic resin of Preparation Example 7, 25% by weight of zinc flakes, 10% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 15% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

The following is a comparative example for comparison with the water-soluble rust preventive coating solution according to Example 1.

go. Comparative Example 1

45% by weight of the acrylic resin of Preparation Example 1, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

me. Comparative Example 2

45% by weight of the acrylic resin of Preparation Example 2, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

all. Comparative Example 3

45% by weight of the acrylic resin of Preparation Example 3, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of a dispersant (TEGO-740W), 1% by weight of an antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

La. Comparative Example 4

45% by weight of the acrylic resin of Preparation Example 4, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

mind. Comparative Example 5

45% by weight of the acrylic resin of Preparation Example 5, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

bar. Comparative Example 6

45% by weight of the acrylic resin of Preparation Example 6, 25% by weight of zinc flakes, 5% by weight of aluminum flakes, 2% by weight of dispersant (TEGO-740W), 1% by weight of antirust additive (SYNTRON-080), 20% by weight % of a water-soluble solvent or ionized water, a water-soluble rust preventive coating solution was prepared with the remainder of the surface modifier and pH adjuster.

[Table 1] below compares the properties of the coating solution with the water-soluble rust-preventing coating solution according to Example 1 of the present invention prepared as described above and the respective comparative examples.

adherence luster water resistance corrosion resistance Hardness impact resistance note Comparative Example 1 X O △ △ H △ Comparative Example 2 O X O △ HB X Comparative Example 3 X O O △ H O Comparative Example 4 O X X X F-H X Comparative Example 5 △ O X X HB X Comparative Example 6 △ O O △ H O Example 1 O O O O 2H O Example 2 △ O △ △ H △ Example 3 O X △ △ HB O Example 4 △ △ O △ H △ Example 5 O O O △ H O

The evaluation method is as follows.

- Adhesion: After 1m/m cross cut, it was evaluated by rubbing strongly with 24m/m glass tape to attach it, and then pulling it off quickly to peel it off.

O: 99% or more, △: 99 to 90%, X: 90% or less

- Gloss: Measured using a gloss meter (60 degrees)

O: 60 or more, △: 60-50, X: 50 or less

- Water resistance (boiling water resistance): JIS K-5400 Measured by immersion at 100℃ for 2 hours or more

O: No swelling, △: 5% or less swelling, X: 5% or more swelling

- Corrosion resistance: measured according to JIS K-5400 (35℃ 5% NaCl, 1-2ml/h)

O: 700 hours or more and 5% or less lamination, △: 700 to 500 hours 5% or less lamination, X: 500 hours or less 5% or more lamination occurred

- Hardness: Measured using a Missi BC pencil

- Impact resistance: measured using DuPont impact tester (1/2 inch, 1 kg, 50 cm)

O: no flaw, △: 5% or less flaw, X: 5% or more flaw

Claims (3)

A water-soluble anti-rust coating composition comprising:
acrylic resin;
zinc flakes;
aluminum flakes;
dispersant;
anti-rust additive;
water-soluble solvents or ionized water;
surface modifiers; and
consisting of a pH adjuster,
The acrylic resin is
Polyunsaturated fatty acid and epoxy resin silane are polycondensed so as to consist of molecular chains forming a structure in which polybasic acid, polyhydric alcohol and epoxy are polycondensed and molecular side chains forming a structure in which unsaturated fatty acids and silane are polycondensed to polyalcohol,
After cooling the polycondensation product, a water-soluble polybasic acid is added to react, and a water-soluble polybasic acid is introduced into the molecular side chain to produce a water-soluble epoxy, an alkyd resin intermediate,
It is produced by polymerization-reacting the water-soluble epoxy, alkyd resin intermediate with at least one acrylic monomer capable of radical reaction at a temperature range of 60 to 160 ° C.
The acrylic resin,
10% by weight of methyl methacrylate, 30% by weight of N-butylmethacrylate, 3% by weight of water-soluble epoxy, 10% by weight of water-soluble alkyd resin, 1.5% by weight of silane (methacryl propyl trimethoxysilane Dow Chemical) 6030) and the remainder consisting of a water-soluble solvent and a neutralizing agent,
A water-soluble anti-rust coating solution composition. The method of claim 1,
The radical-reactable acrylic monomer comprises methyl methacrylate,
A water-soluble anti-rust coating solution composition. delete