KR102172043B1 - two component heavy duty paint with non-yellowing for top coating and Heavy duty painting method using the same - Google Patents

Abstract

The present invention relates to a paint for top coat of heavy duty painting and, more specifically, to a two component heavy duty paint for top coat, which satisfies high physical properties required as a heavy duty paint for top coat while minimizing the use of a highly volatile organic solvent, and to a heavy duty painting method using the same.

Description

Two component heavy duty paint with non-yellowing for top coating and Heavy duty painting method using the same}

The present invention relates to a two-component non-yellowing heavy-duty coating used for the top coat, and a heavy-duty coating construction method using the same, when heavy-duty coating construction for structures including steel materials such as ships and bridges.

In general, most structures containing iron are exposed to natural environments and are susceptible to corrosion. In order to improve the weather resistance of the steel structure, it is common to treat the surface of the steel structure with anti-corrosion treatment to prevent corrosion. Corrosion of steel structures is divided into dry and wet corrosion. Dry corrosion is corrosion caused by high-temperature gas, etc., and wet corrosion can cause corrosion in water (fresh water, sea water, etc.), atmospheric corrosion, acid, alkali, salt, etc. Corrosion in can be expressed as wet corrosion.

Heavy-duty coating is performed as a method of protecting steel structures from such, corrosive environments.

Heavy duty coating or high performance coating is a coating and coating to protect bridges, offshore structures, power generation facilities, large structures of various plants, ships, containers, or other steel structures placed in severe corrosive environments from corrosion. As a method, it is a generic term for an anticorrosive coating system that can withstand severe corrosive environments over a long period of time.

Heavy anticorrosive paints require high water resistance and moisture resistance. To prevent rust from occurring, it is most effective not to pass through oxygen or water. Therefore, the coating film should have less water permeability and oxygen permeability as well as less water absorption. Water-soluble water in the phase is excluded as much as possible because it promotes corrosion. In addition, heavy-duty coatings are required to have high ion permeability, acid resistance, and alkali resistance, which do not pass harmful substances that promote rust of steel such as sulfurous acid gas, chlorine gas, carbon dioxide gas, chloride, sulfate, carbonate, acid, and alkali. Because it shouldn't. In addition, heavy-duty coatings should have good hardness and elasticity of the coating film, and should have excellent physical properties because it is likely to cause scratches and defects in the coating film due to impact or friction, and weather resistance, durability, repair coating, and painting workability. , High adhesion to metal surfaces or other coating films is required.

In addition, VOCs regulations on air pollution, which have been recently strengthened internationally, require the development of environmentally friendly paints, and recently, workers in the workplace are threatening the health of painters by unprotected exposure to organic solvents. , In particular, the need for water-based paints is increasing because the risk of suffocation and fire by organic solvents is high for painting work in a closed space.

Korean Patent Publication No. 96-010251 (1996.07.26)

The present invention relates to a medium corrosion coating for top coats of heavy corrosion protection, and an object of the present invention is to provide a paint that satisfies the high physical properties required as a medium corrosion coating for top coats while minimizing the amount of use of a highly volatile organic solvent, and a medium corrosion coating method using the same.

The heavy anticorrosive paint for a top coat of the present invention for solving the above-described problems relates to a two-component non-yellowing heavy anticorrosive paint, and includes a main body (first liquid) and a hardener (second liquid).

As a preferred embodiment of the present invention, the subject (first solution) includes a water-soluble acrylic urethane resin, an anionic dispersant, a fluidizing agent, an antifoaming agent, a pigment, and water.

As a preferred embodiment of the present invention, the subject is water-soluble acrylic urethane resin 60 to 70% by weight, anionic dispersant 2 to 5% by weight, fluidizing agent 1 to 3% by weight, antifoaming agent 0.1 to 1% by weight, pigment 0.1 to 5 It may contain weight percent and the balance of water.

As a preferred embodiment of the present invention, the curing agent (second solution) is (C _1-5 alkylene) glycol (C _1-3 Alkyl) ether acetate, viscosity modifiers and solvents.

As a preferred embodiment of the present invention, the curing agent (C _1-5 alkylene) glycol (C _1-3 of Alkyl) ether acetate may include 70 to 80% by weight, 5 to 10% by weight of a viscosity modifier, and a residual amount of a solvent.

As a preferred embodiment of the present invention, the two-component non-yellowing heavy anticorrosive paint of the present invention is used in a mixture of 1: 5.0 to 7.5 weight ratio of the curing agent and the main material when painting the non-yellowing paint.

As a preferred embodiment of the present invention, the water-soluble acrylic urethane resin may include a reaction product prepared by reacting a polyol and a diisocyanate in a NCO/OH = 0.6 to 0.8 mono-quantity ratio under a reaction catalyst and a solvent.

In a preferred embodiment of the present invention, the polyol is 15 to 25% by weight of polyoxy (alkylene of C _2-3 ) glycol having a weight average molecular weight of 200 to 500, 5 to 15% by weight of a polyol represented by the following formula (1), and It may contain the remaining amount of acrylic polyol.

[Formula 1]

In Formula 1, R ¹ is H, a straight-chain alkyl group of C _1-5 or a branched alkyl group of C _3-5 , R ² is a straight-chain alkylene group of C _1-5 , and n is a natural number of 1 to 4 .

As a preferred embodiment of the present invention, the acrylic polyol is 35 to 45% by weight of a mixed monomer including acrylic acid, 2-hydroxymethacrylate, acrylamide and N-methylolacrylamide, and 0.5 to 1% by weight of a polymerization initiator And after mixing the remaining amount of the solvent, after slowly stirring and preliminary reaction for 1 to 2 hours under 70 ~ 80 ℃, it may include a reaction product prepared by reacting for 2 to 3 hours at 85 ~ 90 ℃. .

As a preferred embodiment of the present invention, the mixed monomer is based on 100 parts by weight of acrylic acid, 35 to 50 parts by weight of 2-hydroxymethacrylate, 5 to 10 parts by weight of acrylamide, and 25 to 35 parts by weight of N-methylolacrylamide. It may include parts by weight.

As a preferred embodiment of the present invention, the diisocyanate of the water-soluble acrylic urethane resin component is 4,4`-dicyclohexylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate. It may include at least one selected from isocyanate (IPDI).

As a preferred embodiment of the present invention, the anionic dispersant among the main components may include at least one selected from dimethyl propionic acid (DMPA) and dimethyl butanoic acid (DMBA).

As a preferred embodiment of the present invention, the fluidizing agent among the main components is a polylignin sulfonic acid condensate (LSF) surfactant, a polycarboxylic acid (PC) surfactant, and a polymelamine sulfonic acid sodium condensate (PMS) surfactant. It may include one or more selected from among.

In a preferred embodiment of the present invention, the viscosity modifier of the curing agent component is dioctyl adipate, 2,2,4-trimethyl-1,3-pentanediol diisobutylate, trimellitic acid ester (trimellitate) and ethylcyclo It may contain at least one selected from hexane.

In a preferred embodiment of the present invention, the solvent of the curing agent contains alcohol and water in a volume ratio of 1: 5 to 10, and the alcohol is t-butyl alcohol, t-amyl alcohol. alcohol), diacetone alcohol, and alpha-terpineol.

Another object of the present invention is to provide an intermediate coating method for performing painting construction using the two-component non-yellowing medium coating for topcoat described above.

As a preferred embodiment of the present invention, the middle corrosion coating method of the present invention comprises a first step of surface treatment of the middle corrosion coating construction material; A second step of performing primer coating by applying a primer to the surface of the surface-treated construction object; 3 step of performing intermediate coating by applying an epoxy-based paint to the surface of the undercoat performed construction; And a 4 step of performing a top coat by applying the above-described two-component non-yellowing heavy-duty paint for a top coat to the surface of the intermediately performed construction object.

As a preferred embodiment of the present invention, the heavy-duty coating construction material may include a structure including a steel material.

The two-pack type non-yellowing heavy anticorrosive paint of the present invention uses a highly volatile solvent to a minimum, and has excellent coating workability and repair coating properties, as well as excellent adhesion and adhesion to the underlying and/or intermediate coatings. It has good hardness and elasticity, and excellent chemical resistance and weather resistance such as acid resistance and alkali resistance, so that yellowing does not occur, and it has excellent anti-corrosion effect for water-soluble substances due to high water resistance and low oxygen permeability.

Hereinafter, the present invention will be described in more detail.

The heavy anticorrosive paint of the present invention is a paint applied to a top coat during heavy anticorrosive coating, and is a two-component heavy anticorrosive paint including a first liquid, a main material and a second liquid, a hardener.

When the top coat is painted, the curing agent (second solution) and the main material (first solution) are in a weight ratio of 1: 5.0 to 7.5, preferably the curing agent and the main material in a weight ratio of 1: 5.5 to 7.0, more preferably 1: 6.0 It can be mixed and used in a weight ratio of ~ 7.0. At this time, if the amount of the main substance used is less than 5.0 weight ratio, the curing speed may be too fast, so that the painting workability may deteriorate. If the amount of the main substance used exceeds 7.5 weight ratio, there may be a problem that the coating film formation is too late, so it is recommended to use it within the above range.

[subject]

Among the heavy anticorrosive paint components, the main material includes a water-soluble acrylic urethane resin, an anionic dispersant, a fluidizing agent, an antifoaming agent, a pigment, and water.

The content of the water-soluble acrylic urethane resin in the main component is 60 to 70% by weight, preferably 63 to 70% by weight, more preferably 64.5 to 68.5% by weight of the total weight of the main material, and if it is less than 60% by weight, the coating film is well formed. It may not be possible, and the physical properties of the coating film may be rather poor, and if it exceeds 70% by weight, the viscosity of the paint is too high and the paintability is rather poor, and the problem of agglomeration due to the remaining resin that is not dissolved in water as a solvent There may be.

Among the main components, the water-soluble acrylic urethane resin includes a reaction product prepared by reacting a polyol and a diisocyanate under a reaction catalyst and a solvent.

The polyol used in the production of water-soluble acrylic urethane resin is 15 to 25% by weight of polyoxy (alkylene of C _2-3 ) glycol having a weight average molecular weight of 200 to 500, 5 to 15% by weight of polyol represented by the following formula (1) and the balance Of acrylic polyol, preferably 18 to 24% by weight of polyoxy (alkylene of C _2-3 ) glycol having a weight average molecular weight of 250 to 450, 5 to 12% by weight of a polyol represented by the following formula (1), and It may contain the remaining amount of acrylic polyol.

Among the polyol components, the polyoxy (C _2-3 alkylene) glycol is introduced to prevent oxygen permeation and increase the adhesion of the coating film formed of the heavy anticorrosive coating of the present invention, and polyoxy (C _2-3) If the content of alkylene) glycol is less than 15% by weight of the total weight of the polyol, oxygen permeation prevention and adhesion may be deteriorated, and if it is used in excess of 25% by weight, there may be a problem that the flexibility and hardness of the coating film are lowered. .

In addition, the polyol represented by the following formula (1) among the polyol components serves to increase the chemical resistance, weather resistance, and yellowing resistance of the coating film.If the amount is less than 5% by weight of the total weight of the polyol, the yellowing resistance and chemical resistance of the coating film are There may be a drop problem, and if it is used in excess of 15% by weight, there may be a problem in that water resistance and alkali resistance are poor, so it is recommended to use within the above range.

[Formula 1]

In Formula 1, R ¹ is H, a straight-chain alkyl group of C _1-5 or a branched alkyl group of C _3-5 , preferably R ¹ is H or a straight-chain alkyl group of C _1-5 , more preferably It is a straight-chain alkyl group of H or C _1-2 . In addition, R ² in Formula 1 is a C _1-5 linear alkylene group, and preferably a C _1-3 linear alkylene group. In addition, n in Formula 1 is a natural number of 1 to 4, preferably a natural number of 1 to 2.

In addition, the acrylic polyol of the polyol component is an acrylic polyol having a weight average molecular weight of 3,500 to 15,000, preferably a weight average molecular weight of 4,500 to 12,000, and more preferably 6,500 to 10,500.

The acrylic polyol was mixed with acrylic acid, 2-hydroxymethacrylate, acrylamide, and 35 to 45% by weight of a mixed monomer including N-methylol acrylamide, 0.5 to 1% by weight of a polymerization initiator, and the remaining amount of a solvent, After slowly stirring and preliminary reaction for 1 to 2 hours at 70 to 80°C, the reaction product prepared by reacting at 85 to 90°C for 2 to 3 hours may be included.

In addition, the mixed monomer is based on 100 parts by weight of acrylic acid, 35 to 50 parts by weight of 2-hydroxymethacrylate, 5 to 10 parts by weight of acrylamide, and 25 to 35 parts by weight of N-methylolacrylamide, preferably the The mixed monomer contains 40 to 50 parts by weight of 2-hydroxymethacrylate, 6 to 8 parts by weight of acrylamide and 25 to 32 parts by weight of N-methylolacrylamide, more preferably as long as 100 parts by weight of acrylic acid. I can.

If the content of acrylic acid, 2-hydroxymethacrylate, acrylamide, and N-methylolacrylamide in the mixed monomer is out of the above range, there is a problem of poor physical properties such as mechanical properties and adhesion of the coating film formed with the paint of the present invention. There may be. And, when synthesizing the acrylic polyol, if the mixed monomer content is less than 35% by weight, the weight average molecular weight of the acrylic polyol may be too low to ensure sufficient water resistance, moisture resistance, and paintability, and if it exceeds 45% by weight, the solvent content is relatively Since this is low, the viscosity of the reaction solution may be too high and the reactivity may be lowered. Therefore, it is preferable to perform the reaction after mixing with the polymerization initiator and the solvent in the above content range.

In addition, the polymerization initiator used in the synthesis of acrylic polyol may be a general polymerization initiator used in the art, preferably, one selected from benzoyl peroxide, t-butyl peroxide and potassium per sulfate (potassium per sulfate). It may include the above, more preferably t- butyl peroxide and may include one or more selected from potassium persulfate.

In addition, the solvent used in the synthesis of the acrylic polyol may be a solvent having excellent solubility in a mixed monomer, and is not particularly limited, but as a preferred example, it is preferable to use NMP (N-methylpyrrolidone).

The water-soluble acrylic urethane resin includes a reaction product prepared by reacting the polyol and diisocyanate, and the diisocyanate is 4,4`-dicyclohexylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate ( HDI) and isophorone diisocyanate (IPDI) may include at least one selected from, and may include at least one selected from HDI and IPDI, more preferably HDI and IPDI 1: 2 to 3 weight ratio Can include. The amount of diisocyanate used is such that the polyol and the diisocyanate are reacted in an NCO/OH = 0.6 to 0.8 mono-unit ratio, preferably NCO/OH = 0.65 to 0.75 mono-unit ratio.

The reaction catalyst used in the synthesis of water-soluble acrylic urethane resin may include a tertiary amine catalyst, preferably trialkylamines such as triethylamine, tributylamine, ethylenediamine, 4-dimethylaminopyridine, and benzyldimethylamine , 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0)-undecene, and other compounds may be used alone or in combination.

The solvent used in the synthesis of the water-soluble acrylic urethane resin is not particularly limited, but a preferred example is NMP (N-methylpyrrolidone).

Next, among the main ingredients, the anionic dispersant is a compound having two or more hydroxyl groups and one or more carboxyl groups, helping to dissolve the water-soluble acrylic urethane resin in the main material in water as a solvent, and increasing compatibility with other ingredients. Do it. As the anionic dispersant, dimethyl propionic acid (DMPA) and dimethyl butanoic acid (DMBA) may be used. At this time, the content of the anionic dispersant is 2 to 5% by weight, preferably 2.5 to 4.5% by weight of the total weight of the main body, and at this time, if the content of the anionic dispersant is less than 2% by weight, the adhesion of the coating film is reduced, 5 If it exceeds the weight %, the water resistance of the coating film may rather decrease.

Next, among the main components, the fluidizing agent is used to increase the flowability of the main material and to increase the solubility of the water-soluble acrylic urethane resin in water as a solvent. Polylignin sulfonic acid condensate (LSF) surfactant, polycarboxylic It may contain at least one selected from acid-based (PC) surfactants and polymelamine sulfonic acid sodium condensate-based (PMS) surfactants. In addition, the content of the fluidizing agent is preferably 1 to 3% by weight, preferably 1.0 to 2.5% by weight, more preferably 1.2 to 2.2% by weight of the total weight of the main body, and at this time, if the content of the fluidizing agent is less than 1% by weight Due to poor flow of the main material, a subject that is not well mixed with the second solution, the hardener, may not be formed evenly, and if the content of the fluidizing agent is less than 3% by weight, mechanical properties such as hardness of the coating may be caused by excessive use. Since a problem of deterioration may occur, it is recommended to use within the above range.

Next, the antifoaming agent among the main components is used to suppress the generation of bubbles that may occur when mixing the main material and the curing agent and/or applying paint, and the antifoaming agent is modified silicones, fatty acids, higher alcohols, minerals, higher fatty acid glycerol. It may include at least one selected from light, dimethyl polysiloxane, polypropylene glycol, and hydrophobic silica, and preferably at least one selected from higher fatty acid glycerite, dimethyl polysiloxane and polypropylene glycol. The content of the antifoaming agent is preferably 0.1 to 1.0% by weight, preferably 0.1 to 0.8% by weight, more preferably 0.1 to 0.5% by weight of the total weight of the main body, and if the amount of the antifoaming agent is less than 0.1% by weight, the amount used is too much. The effect of using the antifoaming agent may be insufficient, and the use of more than 1.0% by weight is excessive use and may rather degrade the physical properties of the paint, so it is preferable to use it within the above range.

Next, among the main components, the pigment is used for expressing the color of the paint, and a general pigment used in the art can be used, and the kind can be used to obtain a paint of a desired color. Metal oxide pigments such as titanium and iron oxide, complex oxide pigments such as titanium yellow, carbon black, azo pigments, quinacridone pigments, perylene pigments, perinone pigments, metal chelate azo pigments, coloring pigments, aluminum, copper, Zinc, nickel, aluminum oxide, mica, titanium oxide, or aluminum oxide coated with iron oxide may be used in combination of one or more depending on color or coating performance according to the purpose. In addition, the pigment content is preferably used in less than 4.0% by weight of the total weight of the main body.

In addition, among the main ingredients, the water serves as a solvent for the ingredients in the main subject, and the amount used is the remaining amount in addition to ingredients such as water-soluble acrylic urethane resin, anionic dispersant, fluidizing agent, antifoaming agent, and pigment.

In addition to the aforementioned water-soluble acrylic urethane resin, anionic dispersant, fluidizing agent, defoaming agent, pigment, and water, the subject of the coating component of the present invention is within a range that does not harm the basic physical properties of the coating film, depending on the application environment of the paint or the effect of the desired coating film properties. It may further include additives such as antioxidants, sunscreens, fillers, and leveling agents commonly used in the art.

[Hardener]

The curing agent, which is the second solution in the paint component, is (C _1-5 alkylene) glycol (C _1-3 Alkyl) ether acetate, a viscosity modifier and a solvent are included, and a curing accelerator may be further included.

In the curing agent component (C _1-5 alkylene) glycol (C _1-3 of Alkyl) ether acetate serves to form a coating film by reacting with the water-soluble acrylic urethane resin of the main component, and the (C _1-5 alkylene) glycol (C _1-3 of The content of the alkyl) ether acetate in the curing agent is preferably 70 to 80% by weight, preferably 72 to 80% by weight, more preferably 74.0 to 78.5% by weight.

Next, among the curing agent components, the viscosity modifier serves to prevent a rapid increase in viscosity due to the reaction between the main material and the curing agent, and dioctyl adipate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate , Trimellitic acid ester (trimellitate) and may contain at least one selected from ethylcyclohexane. And, the content of the viscosity modifier is preferably 5 to 10% by weight, preferably 6 to 10% by weight, more preferably 6.0 to 8.5% by weight of the total weight of the curing agent, and at this time, the content of the viscosity modifier is 5% by weight If it is less than, the effect of preventing rapid increase in viscosity may be insufficient, and if it exceeds 10% by weight, it is rather difficult to match the appropriate viscosity of the paint, so that the paintability of the paint may be degraded, so it is preferable to use it within the above range.

Next, the solvent of the curing agent component may be water, preferably (C _1-5 alkylene) glycol (C _1-3 of For the solubility of alkyl) ether acetate in a solvent, it is recommended to use a solvent in which alcohol and water are mixed, more preferably alcohol and water in a volume ratio of 1: 5 to 10, and even more preferably alcohol and water in a volume ratio of 1 : It is good to include in 6 ~ 8 volume ratio. In addition, the alcohol may include at least one selected from t-butyl alcohol, t-amyl alcohol, diacetone alcohol, and alpha-terpineol, more preferably May include at least one selected from diacetone alcohol and alpha-terpineol.

In addition, the curing agent, which is the second solution, is for accelerating the curing reaction, and may be optionally additionally applied during winter. The curing accelerator may contain at least one selected from metal-based curing accelerators, imidazole-based curing accelerators, and amine-based curing accelerators in an amount of 1% by weight or less of the total weight of the curing agent, and when used in excess of 1% by weight, due to the curing accelerator effect. It is better to use it within the above range because loss due to degradation of other physical properties of the paint (for example, cracking) may be greater than the gain.

As the metal-based curing accelerator, an organometallic complex or an organometallic salt of a metal such as cobalt, copper, zinc, iron, nickel, manganese, tin, etc. may be used. As a specific example of the organometallic complex, cobalt(II) acetylacetonate, Organic cobalt complexes such as cobalt(II) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron such as iron(III) acetylacetonate Complexes, organic nickel complexes such as nickel (II) acetylacetonate, organic manganese complexes such as manganese (II) acetylacetonate, and the like. In addition, the organometallic salt may include at least one selected from zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

The imidazole-based curing accelerator is 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole , 1,2-dimethylimidazole, 2-phenylimidazole, 2-phenyl-4-methyl imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1 -Cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undesilimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2 -Phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 2,3-dihydroxy-1H- It may contain one or more selected from pyrrolo [1,2-a] benzimidazole.

The amine-based curing accelerator is trialkylamine such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl)phenol, and 1,8-diazabi It may contain at least one selected from cyclo (5,4,0)-undecene.

In addition, the curing agent, which is the second liquid, may optionally further include a small amount of a leveling agent in order to further increase the adhesive strength in the composition by leveling so that it can be coated flat and smoothly. The leveling agent may be an acrylic type, a silicone type, or the like, and may include these silicon type or non-silicone type leveling agents such as acrylic type, alone or in combination of two or more.

Hereinafter, a method of performing heavy-duty coating construction using the two-component non-yellowing heavy-duty coating of the present invention will be described.

The two-pack type non-yellowing heavy anticorrosive paint of the present invention of the present invention is applied as a top coat during heavy anticorrosive painting construction, and the first step of surface treatment of the heavy anticorrosive paintwork; A second step of performing primer coating by applying a primer to the surface of the surface-treated construction object; 3 step of performing intermediate coating by applying an epoxy-based paint to the surface of the undercoat performed construction; And a 4 step of performing a top coat by applying the above-described two-component non-yellowing heavy-duty paint for a top coat to the surface of the intermediately performed construction object.

The heavy-duty coating construction product is a structure including steel material, and includes bridges, offshore structures, power generation facilities, large structures of various plants, ships, containers, or other steel structures placed in severe corrosive environments.

The surface treatment method in step 1 can be performed by a general surface treatment method used in the art, and a preferred example is to peel off the existing paint applied to the steel surface of the heavy-duty coating construction, and place the existing paint on a floating position. It can remove pollutants such as rust or dust and oil on the surface of the steel. More specifically, after soaking and removing contaminants on the surface of the steel using high-pressure water, the work can be performed using a hand-type grinder containing an abrasive containing a diamond tip to which a dust collector is connected.

Next, as the primer of the second step, a general primer used in the art may be used, for example, a primer containing a corrosion inhibitor may be applied to perform primer coating.

Next, for the intermediate degree of step 3, an epoxy-based paint may be used, and preferably a solvent-free epoxy-based paint may be used. For a preferred example, the solvent-free epoxy-based paint is a two-component paint comprising a main material (first solution) and a curing agent (second solution), wherein the main material includes a liquid epoxy resin, a reactive diluent, and a filler, and the curing agent It may contain an amine resin and water. And, after mixing the main material and the curing agent, it can be applied to the surface of the undercoat performed construction material to perform the intermediate coating.

Next, the topcoat of the fourth step is performed using the two-component non-yellowing medium anticorrosive coating of the present invention described above, and the application method may be performed by a general method used in the art, and is not particularly limited. In addition, it is preferable to perform the application in an amount of about 0.9 to 1.2 L of a two-component non-yellowing neutral anticorrosive paint per 10 m ² .

Hereinafter, the present invention will be described in more detail through examples, but the following examples do not limit the scope of the present invention, which should be interpreted to aid understanding of the present invention.

[Example]

Preparation Example 1: Preparation of water-soluble acrylic urethane resin

(1) polyol production

A polyol was prepared by mixing 22.5% by weight of polyoxyethylene glycol having a weight average molecular weight of 300 to 400, 7.2% by weight of a polyol represented by the following Formula 1-1, and the remaining amount of acrylic polyol having a weight average molecular weight of 8,200 to 8,500.

The acrylic polyol is a mixture of 45.5 parts by weight of 2-hydroxymethacrylate, 7.1 parts by weight of acrylamide, and 27.8 parts by weight of N-methylol acrylamide based on 100 parts by weight of acrylic acid, 42% by weight of a mixed monomer, potassium sulfate as a polymerization initiator 0.7% by weight was added to N-methylpyrrolidone (solvent), and then slowly stirred and pre-reacted at 74 to 75° C. for 1 hour, and then reacted at 88 to 90° C. for 2 hours.

[Formula 1-1]

In Formula 1, R ¹ is a methyl group, R ² is an ethyl group, and n is 2.

(2) Synthesis of water-soluble acrylic urethane resin

Diisocyanate was prepared by mixing 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) at a weight ratio of 1:2.6.

Into a reactor equipped with a stirrer, reflux condenser, nitrogen inlet, and thermometer, N-methylpyrrolidone as a solvent was added, and then the polyol and diisocyanate prepared above were added to the reactor to react at a NCO/OH = 0.70 mono-quantity ratio. Then, 4-dimethylaminopyridine as a reaction catalyst was added. And, the reaction was carried out for 3 hours under a nitrogen atmosphere and 90°C. If the NCO% was measured and within 3.5%, the temperature of the reactant was cooled to room temperature and the reaction was terminated, and then DMEA (Di Methyl Ethanol Amine) was added to neutralize it. Filtering to obtain a water-soluble acrylic urethane resin.

Preparation Examples 2 to 5 and Comparative Preparation Examples 1 to 4

Each of the water-soluble acrylic urethane resins was prepared in the same manner as in Preparation Example 1, but each of the water-soluble acrylic resins was prepared by varying the composition of the polyol used in the synthesis as shown in Table 1 below, and Preparation Examples 2 to 5 and Comparative Preparation Examples 1 to Implemented 4.

division Type and content of polyol Polyoxyethylene glycol Polyol represented by Formula 1-1 Acrylic polyol Preparation Example 1 22.5% by weight 7.2% by weight The remaining 100% by weight Preparation Example 2 18.0% by weight 7.2% by weight The remaining 100% by weight Preparation Example 3 25.0% by weight 7.2% by weight The remaining 100% by weight Preparation Example 4 22.5% by weight 5.0% by weight The remaining 100% by weight Preparation Example 5 22.5% by weight 12.0% by weight The remaining 100% by weight Comparative Preparation Example 1 13.0% by weight 7.2% by weight The remaining 100% by weight Comparative Preparation Example 2 27.5% by weight 7.2% by weight The remaining 100% by weight Comparative Preparation Example 3 22.5% by weight 3.5% by weight The remaining 100% by weight Comparative Preparation Example 4 22.5% by weight 17.0% by weight The remaining 100% by weight

Example 1: Preparation of a two-component topcoat heavy-duty coating

(1) Preparation of solution 1 (subject)

Water-soluble acrylic urethane resin of Preparation Example 1 66.5% by weight, dimethyl propionic acid (DMPA) 3.0% by weight as an anionic dispersant, polylignin sulfonic acid condensate (LSF) surfactant 1.8% by weight as a fluidizing agent, dimethyl polysiloxane 0.3 as an antifoaming agent A main body (1st solution) was prepared by mixing and stirring water for the weight %, the pigment titanium oxide 0.8 weight %, and the balance.

(2) Preparation of the second liquid (hardener)

75.3 wt% of ethylene glycol ethyl ether acetate, 7.4 wt% of dioctyl adipic acid as a viscosity modifier, diacetone alcohol, and water were mixed in a volume ratio of 1:7 and the remaining amount of the solvent was mixed and stirred to prepare a curing agent.

Examples 2 to 5 and Comparative Examples 1 to 4

Each of the first and second solutions was prepared in the same composition as in Example 1, but instead of the water-soluble acrylic urethane resin of Preparation Example 1 among the first liquid components as shown in Table 2 below, Preparation Examples 2 to 5 and Comparative Preparation Examples 1 to Using each of the water-soluble acrylic urethane resins of 4, Examples 2 to 5 and Comparative Examples 1 to 4 were carried out, respectively, to prepare a two-pack type top coat heavy-duty anticorrosive coating.

Examples 6 to 9 and Comparative Examples 5 to 9

Each of the first and second solutions was prepared with the same composition as in Example 1, but Examples 6 to 9 and Comparative Examples 5 to 9 were respectively prepared by varying the content of the composition of the first liquid component as shown in Table 2 below. To prepare a two-component topcoat heavy-duty coating.

division
(weight%) Water soluble acrylic urethane resin Anionic dispersant Fluidizing agent Antifoam Pigment Kinds content content content content content Example 1 Preparation Example 1 66.5 3.0 1.8 0.3 0.8 Example 2 Preparation Example 2 66.5 3.0 1.8 0.3 0.8 Example 3 Preparation Example 3 66.5 3.0 1.8 0.3 0.8 Example 4 Preparation Example 4 66.5 3.0 1.8 0.3 0.8 Example 5 Preparation Example 5 66.5 3.0 1.8 0.3 0.8 Example 6 Preparation Example 1 63.0 3.0 1.8 0.3 0.8 Example 7 Preparation Example 1 68.5 3.0 1.8 0.3 0.8 Example 8 Preparation Example 1 66.5 4.5 1.8 0.3 0.8 Example 9 Preparation Example 1 66.5 3.0 3.0 0.3 0.8 Comparative Example 1 compare
Preparation Example 1 66.5 3.0 1.8 0.3 0.8 Comparative Example 2 Comparative Preparation Example 2 66.5 3.0 1.8 0.3 0.8 Comparative Example 3 Comparative Preparation Example 3 66.5 3.0 1.8 0.3 0.8 Comparative Example 4 Comparative Preparation Example 4 66.5 3.0 1.8 0.3 0.8 Comparative Example 5 Preparation Example 1 58.0 3.0 1.8 0.3 0.8 Comparative Example 6 Preparation Example 1 72.0 3.0 1.8 0.3 0.8 Comparative Example 7 Preparation Example 1 66.5 1.0 1.8 0.3 0.8 Comparative Example 8 Preparation Example 1 66.5 6.0 1.8 0.3 0.8 Comparative Example 9 Preparation Example 1 66.5 3.0 4.2 0.3 0.8 The remaining weight% of the 100 weight% of the main component is a solvent.

Manufacturing Example 1

A primer (DJP-5228 HS primer, PPG Korea) was applied to a steel plate with a thickness of 70 mm 2 and a thickness of 1 mm, which was treated with a chrome treatment with a dry coating thickness of about 6 μm.

Next, a medium coating (trade name Senufon HB 3334, Jeongseok Paint) was applied to the upper portion of the primer-treated specimen to have a dry coating thickness of about 15 μm, followed by intermediate treatment.

Next, the two-component topcoat medium coating of Example 1 was applied to the top of the medium-treated specimen at 1L per 10 m ² of applied amount, and then coated with a dry film thickness of about 12 μm to treat the top coat.

At the time of the top coat treatment, the two-pack type top coat heavy-duty coating was used after mixing the main body (first solution) and the hardener (second solution) at a weight ratio of 6.5:1 and sufficiently stirring.

Preparation Examples 2 to 9 and Comparative Preparation Examples 1 to 9

In the same manner as in Preparation Example 1, a coating film was formed by performing a bottom coat, a middle coat, and a top coat, but Preparation Examples 2 to 9 and Comparative Preparation Examples 1 to 9 were carried out by changing the paints used for the top coat as shown in Table 3 below.

division Top coat division Top coat Manufacturing Example 1 Example 1 Comparative Production Example 1 Comparative Example 1 Manufacturing Example 2 Example 2 Comparative Production Example 2 Comparative Example 2 Manufacturing Example 3 Example 3 Comparative Production Example 3 Comparative Example 3 Manufacturing Example 4 Example 4 Comparative Production Example 4 Comparative Example 4 Manufacturing Example 5 Example 5 Comparative Production Example 5 Comparative Example 5 Manufacturing Example 6 Example 6 Comparative Production Example 6 Comparative Example 6 Manufacturing Example 7 Example 7 Comparative Production Example 7 Comparative Example 7 Manufacturing Example 8 Example 8 Comparative Production Example 8 Comparative Example 8 Manufacturing Example 9 Example 9 Comparative Production Example 9 Comparative Example 9

Experimental Example 1: Measurement of physical properties of coating film

The physical properties of the coating films formed on the iron plates of Preparation Examples 1 to 9 and Comparative Preparation Examples 1 to 9 were measured in the following manner, and the results are shown in Table 4 below.

(1) Film hardening degree

The number of times the coating film peeled off was measured by rubbing the surface of the coating film with a methyl ethyl ketone solvent.

(2) Adhesion strength

It was measured according to KSM6715-01.

(3) Pencil hardness

The hardness of the coating film was measured using UNI-pencil (Mitsubishi).

(4) water resistance

It was measured in accordance with KSM SI02812-2-02, and whether there is no abnormality in swelling, cracking, peeling, or discoloration was measured.

(5) Alkali resistance and acid resistance

Alkali resistance was determined whether there was no abnormality in swelling, cracking, peeling, discoloration, etc. after 72 hours immersion in 10% by volume NaOH aqueous solution.

Acid resistance was measured according to KSM SI02812-1-02, and whether there was no abnormality in swelling, cracking, peeling, discoloration, etc. was measured.

(6) resistance to yellowing

It was measured in accordance with KS F 2274 (WA-A, 20 hours), and whether or not discoloration occurred was measured.

division Film hardening degree
(time) Adhesion strength
(kgf/cm ² ) Pencil hardness Water resistance Alkali resistance
/Acid resistance Yellowing resistance Manufacturing Example 1 161 38.5 H clear No problem/No problem clear Manufacturing Example 2 162 39.2 H clear clear/
clear clear Manufacturing Example 3 157 37.4 H clear clear/
clear clear Manufacturing Example 4 163 38.7 H clear No problem/No problem clear Manufacturing Example 5 154 37.8 H clear No problem/No problem clear Manufacturing Example 6 155 36.2 H clear clear/
clear clear Manufacturing Example 7 167 39.6 H clear clear/
clear clear Manufacturing Example 8 162 35.8 H clear No problem/No problem clear Manufacturing Example 9 158 37.7 H clear No problem/No problem clear Comparative Production Example 1 164 27.8 H clear No problem/No problem clear Comparative Production Example 2 141 33.5 F Swelling occurs clear/
clear clear Comparative Production Example 3 163 38.9 H offshoot
Occur Discoloration/
Peeling occurs Discoloration Comparative Production Example 4 142 36.8 F clear No problem/No problem clear Comparative Production Example 5 130 30.2 F Swelling occurs clear/
clear clear Comparative Production Example 6 170 39.8 H Swelling
Occur clear/
clear clear Comparative Production Example 7 164 29.3 H clear clear/
clear clear Comparative Production Example 8 157 38.2 H Cracking clear/
Peeling occurs clear Comparative Production Example 9 134 37.5 H clear No problem/No problem clear

Looking at the measurement results of the physical properties in Table 4, it was confirmed that in the case of Preparation Examples 1 to 9 in which the coating film was formed with the two-component topcoat medium-corrosion coating of the present invention, it has overall high mechanical properties, water resistance, alkali resistance, acid resistance and yellowing resistance. Could

On the other hand, in the case of Comparative Production Example 1 using the paint of Comparative Example 1 using 13% by weight of polyoxyethylene glycol less than 15% by weight when preparing the main body, there was a problem that the adhesion strength with Preparation Example 2 (18% by weight) was significantly low. . And, in the case of Comparative Preparation Example 2 using the paint of Comparative Example 2 using 27.5% by weight exceeding 25% by weight of polyoxyethylene glycol, as compared to Preparation Example 3 (25% by weight), the flexibility of the coating film was It fell, and there was a problem of lowering the hardness and a problem of poor water resistance.

In addition, in the case of Comparative Preparation Example 3 using the paint of Comparative Example 3 using 3.5% by weight of the polyol represented by Formula 1 in the polyol at the time of preparation, when compared to Preparation Example 4 (5% by weight), internal sulfur There was a problem of poor denaturation and chemical resistance. And, in the case of Comparative Preparation Example 4 in which 17% by weight of the polyol represented by Formula 1 in the polyol was used during the preparation of the subject, chemical resistance and yellowing resistance (accelerated weather resistance) were excellent, but when compared to Preparation Example 5 (12% by weight) Rather, there was a problem in that the curing degree and pencil hardness of the coating film were significantly lowered.

In addition, in the case of Comparative Preparation Example 5 using the paint of Comparative Example 5 to which the main material containing a water-soluble acrylic urethane resin in less than 60% by weight of 58.0% by weight was applied, compared to Preparation Example 6 (63% by weight), the overall mechanical The results showed poor physical properties. And, in the case of Comparative Production Example 6 using the paint of Comparative Example 6 to which the subject comprising a water-soluble acrylic urethane resin in an amount of 72.0% by weight exceeding 70% by weight was applied, as compared to Preparation Example 7 (68.5% by weight), mechanical properties, etc. Although the overall physical properties are good, there is a problem that the surface of the coating film is uneven.

In addition, in the case of Comparative Preparation Example 7 using the paint of Comparative Example 7 to which the main material containing 1.0% by weight of less than 2% by weight of anionic dispersant was applied, compared to Preparation Example 1, there was a problem that the adhesion strength was significantly lowered. In the case of Comparative Production Example 8 using the paint of Comparative Example 8 to which the main material containing the dispersant in an amount of 6.0 wt% exceeding 5 wt% was applied, compared to Preparation Example 8 (4.5 wt%), the adhesion strength was excellent, but water resistance and acid resistance This showed bad results.

In addition, in the case of Comparative Preparation Example 9 using the paint of Comparative Example 9 to which a main material containing a fluidizing agent in an amount of 4.2% by weight exceeding 3% by weight was applied, Preparation Example 1 (1.8% by weight) and Preparation Example 9 (3.0% by weight) and In comparison, there was a problem that the hardness of the coating film was rapidly decreased.

Claims (13)

Subjects including water-soluble acrylic urethane resins, anionic dispersants, fluidizing agents, defoaming agents, pigments and water; And
(C _1-5 alkylene) glycol (C _1-3 Alkyl) ether acetate, a viscosity modifier, and a curing agent containing a residual amount of a solvent; and,
The water-soluble acrylic urethane resin includes a reaction product prepared by reacting a polyol and a diisocyanate in a NCO/OH = 0.6 to 0.8 mono-quantity ratio under a reaction catalyst and a solvent,
The polyol includes 15 to 25% by weight of polyoxy (alkylene of C _2-3 ) glycol having a weight average molecular weight of 200 to 500, 5 to 15% by weight of polyol represented by the following Formula 1, and the balance of acrylic polyol,
When painting the non-yellowing paint, the curing agent and the main material are mixed and used in a weight ratio of 1: 5.0 to 7.5.
[Formula 1]

In Formula 1, R ¹ is H, a straight-chain alkyl group of C _1-5 or a branched alkyl group of C _3-5 , R ² is a straight-chain alkylene group of C _1-5 , and n is a natural number of 1 to 4 .
The method of claim 1, wherein the subject is water-soluble acrylic urethane resin 60 to 70% by weight, anionic dispersant 2 to 5% by weight, fluidizing agent 1 to 3% by weight, antifoaming agent 0.1 to 1% by weight, pigment 0.1 to 5% by weight, and A two-component non-yellowing heavy anticorrosive coating for top coats, characterized in that it contains the remaining amount of water.
The method of claim 1, wherein the curing agent is (C _1-5 alkylene) glycol (C _1-3 Alkyl) ether acetate 70 to 80% by weight, viscosity modifier 5 to 10% by weight, and a two-component non-yellowing neutral anticorrosive coating for top coat, characterized in that it comprises a balance of water.
delete The method of claim 1, wherein the acrylic polyol is
After mixing 35 to 45% by weight of a mixed monomer including acrylic acid, 2-hydroxymethacrylate, acrylamide and N-methylolacrylamide, 0.5 to 1% by weight of a polymerization initiator, and the remaining amount of solvent, 70 to 80°C After slowly stirring and performing a preliminary reaction for 1 to 2 hours under, a two-component non-yellowing heavy anticorrosive coating for a top coat comprising a reaction product prepared by reacting at 85 to 90° C. for 2 to 3 hours.
The method of claim 1, wherein the mixed monomer is
A two-component radish for top coat comprising 35 to 50 parts by weight of 2-hydroxymethacrylate, 5 to 10 parts by weight of acrylamide, and 25 to 35 parts by weight of N-methylolacrylamide based on 100 parts by weight of acrylic acid. Yellowing medium anticorrosive paint.
The method of claim 1, wherein the diisocyanate includes at least one selected from 4,4`-dicyclohexylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI). A two-component non-yellowing heavy-duty coating for top coat, characterized in that.
The method of claim 1, wherein the anionic dispersant comprises at least one selected from dimethyl propionic acid (DMPA) and dimethyl butanoic acid (DMBA),
The fluidizing agent comprises at least one selected from a polylignin sulfonic acid condensate (LSF) surfactant, a polycarboxylic acid (PC) surfactant, and a polymelamine sulfonic acid sodium condensate (PMS) surfactant. Two-component, non-yellowing, heavy-duty coating for top coats.
The method of claim 1, wherein the viscosity modifier is at least one selected from dioctyl adipate, 2,2,4-trimethyl-1,3-pentanediol diisobutylate, trimellitic acid ester, and ethylcyclohexane. A two-pack type non-yellowing heavy anticorrosive coating for a top coat, characterized in that it comprises a.
The method of claim 1, wherein the solvent of the curing agent is
Alcohol and water containing at least one selected from t-butyl alcohol, t-amyl alcohol, diacetone alcohol, and alpha-terpineol in a volume ratio of 1: 5 to 10 A two-component non-yellowing medium anticorrosive coating for top coat, characterized in that it comprises.
A heavy-duty coating method, characterized in that the painting is carried out using the two-component non-yellowing heavy-duty coating for a top coat selected from claims 1 to 3 and 5 to 10.
Step 1 of surface treatment of the heavy-duty coating construction;
A second step of performing primer coating by applying a primer to the surface of the surface-treated construction object;
3 step of performing intermediate coating by applying an epoxy-based paint to the surface of the undercoat performed construction; And
A fourth step of performing a top coat by applying a two-component non-yellowing heavy anticorrosive coating for a topcoat selected from any one of claims 1 to 3 and 5 to 10 on the surface of the intermediately performed construction object;
Middle corrosion coating method comprising a.
The method of claim 12, wherein the heavy-duty coating construction product comprises a structure including a steel material.