KR100816522B1 - Aqueous anti-corrosive paint and method of forming paint layer using the same - Google Patents

Abstract

A water-soluble anti-corrosive paint is provided to be superior in corrosion resistance and adhesion and ensure environment friendliness. A water-soluble anti-corrosive paint includes 30-50wt% of a composite binder resin, 40-50wt% of a zinc powder, and 10-20wt% of an extender. The composite binder resin comprises 10-30wt% of an organic binder resin, 30-50wt% of an inorganic binder resin, and the balance of water. The organic binder resin is any one selected from the group comprising acrylic resins, polyurethane resins, and modified colloidal silica. The inorganic binder resin is at least one selected from the group comprising sodium silicate, potassium silicate, lithium silicate, and colloidal silica.

Description

Aqueous anti-corrosive paint and method of forming paint layer using the same}

The present invention relates to a water-soluble rust-preventive coating and a method for forming a coating film using the same, and more particularly, to a water-soluble rust-preventive coating having excellent corrosion resistance and adhesion and a method for forming a coating film using the same.

In general, the purpose of the coating serves to protect the object internally from the external environment as well as the appearance of the object. In particular, research on rust resisting paints, which serve as internal protection of the coatings, is being actively conducted. The rust preventive paint is a paint used to prevent metals such as iron from being oxidized. Specifically, when the metal is exposed and oxidized by air and water in the atmosphere, the metal is corroded and loses its function. Therefore, the rust-preventive paint is widely used in various coatings, automobile parts and steel structures.

Recently, due to the emission control policy for volatile organic compounds (VOCs), studies on water-soluble rust-preventive coatings are being actively conducted in terms of environmental conservation and workplace improvement.

However, the water-soluble rust-preventive coating has the advantage of minimizing the emission of organic compounds, there is a problem that physical properties such as excellent corrosion resistance and adhesion properties of the oil-based rust-preventive paint containing an organic solvent. In particular, the water-soluble rust-preventive coating using the aqueous organic binder resin is weak in adhesion compared to the oil-based rust-preventive coating. In addition, water-soluble rust-preventive coatings using inorganic binder resins are more poor in corrosion resistance than oil-based rust-preventive coatings. Therefore, while being excellent in corrosion resistance and adhesion, an environmentally friendly water-soluble antirust coating is required.

Therefore, one object of the present invention is to provide an environmentally friendly water-soluble rust-preventive coating at the same time excellent in corrosion resistance and adhesion.

Another object of the present invention is to provide a coating film forming method using the water-soluble antirust coating.

In order to achieve the above object, the water-soluble rust-preventive coating according to the present invention comprises 30 to 50% by weight of the composite binder resin, 40 to 50% by weight of zinc powder and 10 to 20% by weight of the extender pigment, the composite binder resin is organic 10 to 30 wt% binder resin, 30 to 50 wt% inorganic binder resin and excess water.

According to embodiments of the present invention, the organic binder resin may include an acrylic resin, a polyurethane resin, or a modified colloidal silica, and the inorganic binder resin may include sodium silicate, potassium silicate, lithium silicate, colloidal silica, or the like. Can be.

According to the embodiments of the present invention, the composite binder resin may include an additive including 0.1 to 0.5 weight of surfactant, 1 weight of 2 weight% of stabilizer, and 0.1 to 0.5 weight% of water resistance improver, based on the total weight of the composite binder resin. It may further include.

According to embodiments of the present invention, the zinc powder may have an average particle diameter of 3.5 to 9 ㎛.

According to embodiments of the present invention, the extender pigment may include calcium carbonate, silica, synthetic silica, barium sulfate, aluminum silicate, or the like.

In order to achieve the above another object, the coating film forming method according to the present invention firstly provides a composite binder resin containing 10 to 30% by weight of an organic binder resin, 30 to 50% by weight of an inorganic binder resin and excess water. 30 to 50% by weight of the composite binder resin, 40 to 50% by weight of zinc powder and 10 to 20% by weight of an extender pigment are prepared to prepare a water-soluble rust-preventive paint. Next, the paint is coated on the object and cured.

According to the present invention, by using the composite binder resin containing the organic binder resin and the inorganic binder resin, the water-soluble rust-preventive paint can improve the adhesiveness which is a problem of the organic binder resin, and improve the corrosion resistance which is a problem of the inorganic binder resin. have. In addition, as an environmentally friendly water-soluble rust preventive paint, it is possible to minimize the emission of organic solvents can improve the health of workers and the environment of the workplace.

 Hereinafter, a water-soluble rust-preventive coating and a method for forming a coating film using the same according to preferred embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and those skilled in the art. If the present invention can be implemented in various other forms without departing from the spirit of the present invention.

Water soluble antirust paint

The water-soluble rust-preventive coating according to the present invention is a paint used to prevent corrosion of metals such as iron, and the like, which is a problem of a water-soluble rust-preventive paint including an organic binder resin or an aqueous rust-preventive paint including an inorganic binder resin. To solve problems such as corrosion resistance and adhesion. In addition, to provide an environment-friendly water-soluble rust-proof paint that can minimize the emission of organic solvents with excellent corrosion resistance and adhesion.

According to embodiments of the present invention, the water-soluble coating composition may include a composite binder resin, zinc powder and extender pigment.

It demonstrates concretely about the composite binder resin contained in the said water-soluble antirust coating. The composite binder resin may include an organic binder resin, an inorganic binder resin, and water.

When the composite binder resin is less than about 30% by weight relative to the total weight of the water-soluble rustproof paint, physical properties such as water resistance and adhesion are lowered, and when the composite binder resin is more than about 50% by weight, the corrosion resistance is deteriorated. Can be. Thus, the aqueous coating composition contains 30 to 50% by weight of the composite binder resin.

The organic binder resin included in the composite binder resin serves to improve corrosion resistance, which is a problem of the water-soluble rust-preventive coating containing the inorganic binder resin. As an example of the said organic binder resin, an acrylic resin, a polyurethane resin, modified colloidal silica, etc. are mentioned.

As an example of the said acrylic resin, ACSFAL 296D (brand name) of BASF, ACRONAL 290D (brand name), etc. are mentioned.

If the glass transition temperature of the said acrylic resin is less than about -20 degreeC, physical properties, such as hardness and scratch resistance of a cured coating film, fall. In addition, when the glass transition temperature of the acrylic resin exceeds about 30 ° C., when the glass transition temperature is mixed with the inorganic binder resin having a high glass transition temperature, the hardness becomes high, so that the cured coating film is easily cracked due to the occurrence of fine cracks. Therefore, the glass transition temperature of the acrylic resin is preferably -20 to 30 ℃.

The polyurethane resin may be synthesized by reacting a polyol and an isocyanate. Examples of the polyol used in the polyurethane resin include acrylic polyols, polyester polyols, polyether polyols, polycarbonate polyols, and the like. Moreover, hexamethylene diisocyanate, isophorone diisocyanate, etc. are mentioned as an isocyanate used for the said polyurethane resin. Examples of the polyurethane resins include NeoRez R-961 (trade name), NeoRez R-981 (trade name), NeoRez R-987 (trade name), Bayhydrol 122 (trade name), Bayhydrol 123 (trade name), Bayhydrol 124 (trade name) of AVECIA. Brand name), etc. are mentioned.

The modified colloidal silica may be synthesized by copolymerizing two or more monomers into colloidal silica. As an example of the modified colloidal silica, Mowinyl 8010, Mowinyl 8020, etc. of Nichigo-Mowinyl Corporation can be used.

When the organic binder resin is less than about 10% by weight relative to the total weight of the composite binder resin, the corrosion resistance for the purpose of using the organic binder is lowered, and when the organic binder resin exceeds about 30% by weight, At the time of mixing, no mixing is performed, and silicic acid may precipitate. Therefore, it is preferable that the said composite binder resin contains 10-30 weight% of organic binder resin.

The inorganic binder resin included in the composite binder resin serves to improve adhesion, which is a problem of the organic binder resin. Examples of the inorganic binder resin include sodium silicate, potassium silicate, lithium silicate, colloidal silica and the like. These can be used individually or in mixture. Examples of the colloidal silica include Ludox HS-30 (trade name), Ludox HS-30 (trade name), Ludox SM (trade name), Ludox AM (trade name), etc. of Grace Corporation.

As an example, when using the inorganic binder resin by mixing the sodium silicate and lithium silicate, the lithium silicate and sodium silicate preferably has a mixing ratio of about 1: 1 to 4. Alternatively, when the inorganic silica resin is used by mixing the potassium silicate and the lithium silicate, the lithium silicate and the potassium silicate preferably have a mixing ratio of about 1: 3 to 5.

In addition, the acid value colloidal silica may be precipitated when used in combination with sodium silicate, potassium silicate or lithium silicate. Therefore, when colloidal silica is used as an inorganic binder resin, it is preferable to use colloidal silica with an acid value alone.

When the said inorganic binder resin is less than about 30 weight% with respect to the total weight of the said composite binder resin, physical properties, such as adhesiveness which are the objectives of using an inorganic binder, fall. In addition, when the inorganic binder resin is more than about 50% by weight, not only the water resistance is lowered but also the hardness is high, so that fine cracks occur in the cured coating film and are easily broken. Therefore, it is preferable that the said composite binder resin contains 30 to 50 weight% of inorganic binder resin.

Water contained in the composite binder resin is a main solvent to replace the organic solvent, and plays an important role in providing an environment-friendly water-soluble rust-preventive paint. Further, by controlling the solid content of the organic binder resin and the inorganic binder resin to be mixed, it serves to adjust the viscosity of the water-soluble rust-preventive paint. Examples of the water include deionized water and pure water.

The composite binder resin may further include an additive including a surfactant, a stabilizer, and a water resistance improver.

 The surfactant serves to improve the wetting phenomenon of the extender pigments when the composite resin, zinc powder and extender pigments are mixed. The surfactant may be a nonionic surfactant or anionic surfactant. Examples of the nonionic surfactants include nonyl phenol surfactants, and the anionic surfactants include sulfonyl surfactants and the like.

With respect to the total weight of the composite binder resin, when the surfactant is less than about 0.1% by weight, wetting of the extender pigment is reduced, and when the surfactant exceeds about 0.5% by weight, the water resistance and hardness may be lowered. have. Thus, the composite binder resin contains 0.1 to 0.5 wt% of surfactant.

The stabilizer serves to improve the shelf life of the coating composition. The stabilizer may comprise a complex stabilizer comprising a silanol and a cationic surfactant. Examples of the stabilizer include Betolin Quart 15 (brand name), Betolin Quart 20 (brand name), Betolin Quart 25 (brand name), Betolin Quart 32 (brand name), Betolin A11 (brand name), Betolin A100 (brand name), Betolin V30 (brand name). Brand name), etc. are mentioned.

With respect to the total weight of the composite binder resin, when the stabilizer is less than about 1% by weight, the shelf life of the paint is lowered. When the stabilizer is greater than about 2% by weight, the water resistance and hardness may be lowered. Therefore, it is preferable that the said composite binder resin contains 1 to 2% of stabilizer.

The water resistance improver may use bismuth vanadate-based inorganic material or aluminum phosphate-based. However, when using the aluminum phosphate-based as a water resistance improver, when mixed with an inorganic binder resin containing sodium silicate, potassium silicate or lithium silicate, silicic acid may be precipitated. Therefore, it is preferable to use the said aluminum phosphate type when it contains an inorganic binder resin alone by colloidal silica.

With respect to the total weight of the composite binder resin, the water resistance is lowered when the water resistance improver is less than about 0.1% by weight, and when the water resistance improver is exceeded about 0.5% by weight, the storage property of the paint is lowered. Therefore, it is preferable that the said composite binder resin contains 0.1 to 0.5 weight% of water resistance improvers.

The zinc powder contained in the said water-soluble rustproof coating is demonstrated concretely.

If the said zinc powder has an average particle diameter of about 3.5 micrometers, its hardness will become poor, and if an average particle diameter exceeds about 9 micrometers, a coating-film appearance will become bad. Therefore, it is preferable that the said eyelid powder has an average particle diameter of 3.5-9 micrometers.

Corrosion resistance is lowered when the zinc powder is less than about 40% by weight, and when the zinc powder is more than about 50% by weight, the hardness is high, and a fine crack occurs in the cured coating film. Can be. Therefore, it is preferable that the said water-soluble rust-proof paint contains 40 to 50 weight% of zinc powder.

It demonstrates concretely about the extender pigment contained in the said water-soluble antirust paint. Examples of the extender pigments include calcium carbonate, silica, synthetic silica, barium sulfate, aluminum silicate and the like. These can be used individually or in mixture.

When the extender pigment is less than about 10% by weight relative to the total weight of the water-soluble rust-preventive paint, the hardness of the cured coating film is lowered. When the extender pigment is more than about 20% by weight, the hardness is increased, so that the crack is finely cracked in the cured coating film. This happens so it can break. Therefore, it is preferable that the said water-soluble rust-proof paint contains 10-20 weight% of extender pigments.

Coating film formation method

First, a composite binder resin including 10 to 30 wt% of organic binder resin, 30 to 50 wt% of inorganic binder resin and excess water is prepared. 30 to 50% by weight of the composite binder resin, 40 to 50% by weight of zinc powder and 10 to 20% by weight of an extender pigment are prepared to prepare a water-soluble rust-preventive paint. Here, since the details of the water-soluble rust-preventive coating have been described in detail above, it will be omitted to avoid duplication.

Subsequently, the paint is coated using a spray method or the like to have a uniform thickness on the object. Thereafter, the coated paint is cured to form a coating film having excellent corrosion resistance and adhesion.

Hereinafter, embodiments of the present invention will be described in detail. The following contents are expressed in parts by weight.

<Example 1>

20 g of organic binder resin (polyurethane resin, NeoRez R-961), 50 g of inorganic binder resin (40 g of silicate and 10 g of lithium silicate), 0.5 g of surfactant (nonyl phenolic surfactant), 2 g of stabilizer (Betolin A11) in a container Then, 0.5 g of water resistance improver (Bismuth Vanadate-based inorganic material) and 27 g of deionized water were added thereto and stirred. As a result, 100 g of composite binder resin was obtained.

40 wt% of zinc powder and 10 wt% of extender pigment (calcium carbonate) were added to 50 g of the composite binder resin, and the mixture was sufficiently stirred. As a result, 100 g of water-soluble rust-preventive paint was obtained.

<Example 2>

30 g of organic binder resin (modified colloidal silica, Mowinnyl 8020), 40 g of inorganic binder resin (colloidal silica), 0.5 g of surfactant (nonyl phenol-based surfactant), 2 g of stabilizer (Betolin A11), water resistance enhancer (Bismuth Vanadate) 0.5 g and 27 g deionized water were added and stirred. As a result, 100 g of composite binder resin was obtained.

40 g of zinc powder and 10 g of extender pigment (calcium carbonate) were added to 50 g of the composite binder resin, and the mixture was sufficiently stirred. As a result, 100 g of water-soluble rust-preventive paint was obtained.

<Example 3>

30 g of organic binder resin (modified colloidal silica, Mowinnyl 8020), 40 g of inorganic binder resin (30 g of potassium silicate and 10 g of lithium silicate), 0.5 g of surfactant (nonyl phenolic surfactant), 2 g of stabilizer (Betolin A11), water resistance 0.5 g of an improving agent (Bismuth Vanadate-based inorganic material) and 27 g of deionized water were added thereto and stirred. As a result, 100 g of composite binder resin was obtained.

40 g of zinc powder and 10 g of extender pigment (calcium carbonate) were added to 50 g of the composite binder resin, and the mixture was sufficiently stirred. As a result, 100 g of water-soluble rust-preventive paint was obtained.

<Example 4>

30 g of organic binder resin (acrylic resin, ACRONAL 296D), 40 g of inorganic binder resin (30 g of potassium silicate and 10 g of lithium silicate), 0.5 g of surfactant (nonyl phenol-based surfactant), 2 g of stabilizer (Betolin A11), water resistance improver 0.5 g of Bismuth Vanadate-based minerals) and 27 g of deionized water were added thereto and stirred. As a result, 100 g of a composite binder resin was obtained.

40 g of zinc powder and 10 g of extender pigment (calcium carbonate) were added to 50 g of the composite binder resin, and the mixture was sufficiently stirred. As a result, 100 g of water-soluble rust-preventive paint was obtained.

Comparative Example 1

70 g of organic binder resin (acrylic resin, ACRONAL 296D), 0.5 g of surfactant (nonyl phenol-based surfactant), 2 g of stabilizer (Betolin A11), 0.5 g of water resistance improver (Bismuth Vanadate-based inorganic material), and 27 g of deionized water were added to a container. It was. As a result, 100 g of composite binder resin was obtained.

40 g of zinc powder and 10 g of extender pigment (calcium carbonate) were added to 50 g of the composite binder resin, and the mixture was sufficiently stirred. As a result, 100 g of water-soluble rust-preventive paint was obtained.

Comparative Example 2

70 g of inorganic binder resin (35 g of silicate and 35 g of lithium silicate), 0.5 g of surfactant (nonyl phenolic surfactant), 2 g of stabilizer (Betolin A11), 0.5 g of water resistance improver (Bismuth Vanadate inorganic), and 27 g of deionized water were added thereto and stirred. . As a result, 100 g of composite binder resin was obtained.

40 g of zinc powder and 10 g of extender pigment (calcium carbonate) were added to 50 g of the composite binder resin, and the mixture was sufficiently stirred. As a result, 100 g of water-soluble rust-preventive paint was obtained.

Table 1 Composite Binder Resin

[Table 2] Water Soluble Antirust Paint

 Configuration Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Resin 1 50 - - - - - Resin 2 - 50 - - - - Resin 3 - - 50 - - - Resin 4 - - - 50 - - Resin 5 - - - - 50 - Resin 6 - - - - - 50 Zinc powder 40 40 40 40 40 40 Sieving pigment 10 10 10 10 10 10

Physical property evaluation

In order to conduct physical property experiments, water-soluble rust-preventive paints prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were prepared. After coating the water-soluble rust-preventive coating on a 2T hot rolled steel sheet, it was dried for about 20 minutes at a temperature of about 150 ℃.

Each physical property shown in Table 3 was measured by the following method. First, corrosion resistance was deposited by using the ASTM B117 method for about 70 hours, about 120 hours or about 240 hours, and then confirmed the degree of coating on the coated surface. The pencil hardness measured the hardness of a coating film using the NCCA-II-12 method. Adhesion was measured to the extent of peeling in about 100 1 mm cross cuts using the ASTM D3359 tape adhesion method.

Evaluation criteria for corrosion resistance and adhesion are ◎ excellent, ○ is good, △ is normal and × is poor, the evaluation criteria of pencil hardness means that the hardness of H becomes better as the number of H increases.

TABLE 3

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Corrosion resistance (72 hours) ◎ ◎ ◎ ◎ △ X Corrosion resistance (120 hours) ◎ ◎ ◎ ◎ △ X Corrosion resistance (240 hours) ◎ ◎ △ △ △ X Pencil hardness 3H H 2H H H H Adhesion ◎ ◎ △ ◎ X △

As can be seen in Table 3, it can be seen that the water-soluble rust-preventive paints of Examples 1 to 4 according to the present invention have excellent mechanical properties such as chemical resistance and pencil hardness and adhesion. In particular, it can be seen that Comparative Example 1, which does not contain an inorganic binder resin, is poor in adhesion, and Comparative Example 2, which does not include an organic binder resin, is poor in corrosion resistance. On the other hand, it can be seen that Examples 1 to 4 including the organic binder resin and the inorganic binder resin have good or excellent corrosion resistance and adhesion.

As described above, the water-soluble rust-preventive coating according to the present invention can improve the corrosion resistance, which is a problem of the organic binder resin and the problem of the inorganic binder resin by using a composite binder resin containing an organic binder resin and an inorganic binder resin. Can be. As a result, it is not only environmentally friendly, but also can provide a water-soluble rust-preventive coating excellent in physical properties such as corrosion resistance and adhesion, it can be used integrating the water-soluble rust-preventive paint that is dualized.

As described above, the present invention has been described with reference to the preferred embodiments of the present invention, but a person of ordinary skill in the art does not depart from the spirit and scope of the present invention as set forth in the claims below. It will be understood that various modifications and changes can be made.

Claims (6)

30 to 50% by weight of the composite binder resin; Zinc powder 40 to 50% by weight; And 10 to 20% by weight of the extender pigment, wherein the composite binder resin is 10 to 30% by weight of organic binder resin, 30 to 50% by weight of inorganic binder resin and water-soluble rust-preventive paint, characterized in that excess water. The method of claim 1, wherein the organic binder resin is any one selected from the group consisting of acrylic resins, polyurethane resins and modified colloidal silica, the inorganic binder resin is composed of sodium silicate, potassium silicate, lithium silicate and colloidal silica Water-soluble rust-preventive paint, characterized in that at least one selected from the group. The method of claim 1, wherein the composite binder resin further comprises an additive, based on the total weight of the composite binder resin, 0.1 to 0.5 wt% surfactant, 1 wt% 2 wt% stabilizer and 0.1 to 0.5 wt% water resistance improver A water-soluble rust preventive paint, characterized in that The water-soluble rust-preventive paint according to claim 1, wherein the zinc powder has an average particle diameter of 3.5 to 9 µm. The water-soluble rustproof paint according to claim 1, wherein the extender pigment is at least one selected from the group consisting of calcium carbonate, silica, synthetic silica, barium sulfate, and aluminum silicate. Preparing a composite binder resin including 10 to 30 wt% of an organic binder resin, 30 to 50 wt% of an inorganic binder resin, and excess water; Preparing a water-soluble rust-preventive paint in which 30 to 50% by weight of the composite binder resin, 40 to 50% by weight of zinc powder and 10 to 20% by weight of the extender pigment are mixed; And Coating film forming method comprising the step of coating the coating on the object to cure.