KR0157197B1 - Organic coating resin composition for steel plate and preparation process of the same - Google Patents

Abstract

The present invention relates to a liquid resin composition for an organic coating of a steel sheet and a manufacturing method thereof, and more particularly, to an organic coating liquid resin composition used for coating a surface of a steel sheet such as general office equipment, home appliances, automobile parts, and structural structural materials. will be.

That is, the present invention comprises the steps of (a) mixing the water, the initiator and the surfactant to prepare a reaction solution, (b) 2.7 to 5.5% by weight of acrylic acid and 50 ml of water to the reaction solution for 30 minutes, the initiator 0.2 To 0.4% by weight, 19 to 73.2% by weight of acrylic monomer resin, 2.3 to 8% by weight of styrene or 5.9 to 14.2% by weight of divinylbenzene and 0.06 to 0.1% by weight of surfactant are added for 1 hour, and the solution is 75 to 80%. Maintaining at 5 ℃ for 5 hours, and adjusting the solution to pH 9.0 to 9.5 by adding an amine base to prepare an emulsion polymerization solution, (c), about 20 to 40% by weight of silicate to the emulsion polymerization solution Addition and stirring for 30 minutes, and after the addition of 1 to 10% by weight of the silane coupling agent to the total solution was maintained at 80 ℃ for 2 hours, and then 1 to 10% by weight of the lubricant was added for stirring for 1 hour G Steel sheet is a method of manufacturing an organic coating liquid type resin composition.

Moreover, the liquid composition for steel plate organic coatings by this invention is excellent in adhesiveness with a steel plate, and can ensure corrosion resistance, coating property, and degreasing resistance simultaneously.

Description

Liquid resin composition for organic coating of steel sheet

The present invention relates to a liquid resin composition for an organic coating of a steel sheet and a manufacturing method thereof, and more particularly, to an organic coating liquid resin composition used for coating a surface of a steel sheet such as general office equipment, home appliances, automobile parts, and structural structural materials. will be.

Generally, steel sheets used in home appliances, building structural materials, or automobile parts have good mechanical strength and excellent workability, that is, workability, but the chemical resistance, water resistance, adhesion, especially corrosion resistance are weak, which contributes to shortening the lifespan of steel sheets. come. Therefore, in order to solve the problems described above, the life of the steel sheet is extended by galvanizing the steel sheet, but the galvanization alone is difficult to secure high corrosion resistance, so the surface of the steel sheet is treated with chromate or alloy on the zinc plating layer. However, even if the plating treatment with such a metal, the above characteristics can not be completely solved.

As a method of improving the corrosion resistance of the conventional galvanized steel sheet, it has a self-healing effect and performs chromium treatment excellent in white-rust resistance, but the chromium film has corrosion resistance because hexavalent chromium required for self-healing action is eluted in a corrosive environment. It becomes poor. Therefore, in order to compensate for the shortcomings of the chromium film, by coating an appropriate amount of the special organic resin on the upper layer after the chromium treatment, it is possible to suppress the elution of chromium hexavalent, greatly improve the corrosion resistance, and reinforce the corrosion resistance by adding silicate to the resin. have. In addition, it is possible to ensure corrosion resistance, coating property and degreasing resistance at the same time by selecting an organic coating resin system excellent in coating film adhesion to apply to the coating application of the steel sheet.

That is, in order to make use of the above characteristics, the resin composition for the organic coated steel sheet, which has been an organic solvent system or a water-soluble system, has been used by mixing two or more different resins.

The resin composition used in such a two-component resin was a mixture of epoxy resin and acrylic soluble resin (US Pat. Nos. 4,659,394, 4,740,536; EP 0,523,992. A1; UK 2,147,826). A). In addition, epoxy-polyamide-based and polybutadiene-based materials have been used. Among them, epoxy resins are excellent in paintability and corrosion resistance, and acrylic resins are excellent in degreasing resistance. In addition, based on the above two resins, an additive may be added thereto to improve paintability and adhesion to metal, and an organic material may be improved by using styrene-based and acrylic-based modified materials.

However, the above prior art has a disadvantage in that the coating efficiency of the steel sheet is reduced or the process is complicated when the steel sheet is coated with the two-component coating agent using two or more different properties of the resin.

Therefore, an object of the present invention is to provide two or more components of the one-component organic coating resin composition to solve the above problems.

In addition, an object of the present invention is to provide an excellent corrosion resistance, coating property, tilge resistance and the like of the steel sheet coating layer by selecting an organic coating resin system excellent in coating film adhesion.

Hereinafter, the present invention will be described in detail.

The present invention, (a) mixing the water, the initiator and the surfactant to prepare a reaction solution, (b) 2.7 to 5.5% by weight of acrylic acid and 50 ml of water to the reaction solution is added for 30 minutes, the initiator 0.2 to 0.4% by weight, 19 to 73.2% by weight of acrylic monomer resin, 2.3 to 8% by weight of styrene or 5.9 to 14.2% by weight of divinylbenzene and 0.06 to 0.1% by weight of surfactant are added for 1 hour, and the solution is 75 to 80 ° C. It was maintained for 5 hours, and adjusting the solution to pH 9.0 to 9.5 by adding an amine base to prepare an emulsion polymerization solution, (c), to about 20 to 40% by weight of the silicate to the emulsion polymerization solution After stirring for 30 minutes, and after the addition of 1 to 10% by weight of the silane coupling agent to the total solution was maintained for 2 hours at 80 ℃, consisting of 1 to 10% by weight of the lubricant was stirred for 1 hour It is a manufacturing method of the liquid resin composition for steel plate organic coating.

In addition, the present invention is a molar ratio of acrylic acid: methacrylate: ethyl acrylate or n-butyl acrylate: styrene or divinylbenzene produced by the above production method is 0.5-1: 5-15: 0.5-1 and the aqueous phase 70-80% by weight of the emulsion polymerization solution, 20-40% by weight of the silicate relative to the emulsion polymerization solution, silane coupling agent and the lubricant is a liquid resin composition for the organic coating of the steel sheet, respectively 1 to 10% by weight.

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

That is, this invention is a manufacturing method of the liquid resin composition for steel plate organic coatings which consists of the manufacturing method of the following steps (a), (b) and (c).

Step (a) of the present invention is a step of preparing a reaction solution by mixing water, an initiator and a surfactant and maintaining the mixture at 70 to 80 ° C. for 30 minutes.

In the above water, the third distilled purified water is used, and a predetermined value (corresponding to about 300 parts by weight) is used such that the aqueous phase of the emulsion polymerization solution prepared in the next step (b) is about 70 to 80% by weight.

As the initiator, benzoyl peroxide (BPO) or ammonium persulfate (ammoniumpersulfate) is used, and an amount of about 0.2 to 0.4 wt% is used.

In addition, as the surfactant, sodium lauyl sulfate (CH _3- (CH ₂ ) -OSO ₃ Na, hereinafter referred to as SLS) is used, and an amount of about 0.06 to 0.1 wt% is added.

Subsequently, in step (b), 2.7 to 5.5% by weight of acrylic acid and 50 ml of water were gradually added to the reaction solution obtained in step (a) for 30 minutes, and then 0.2 to 0.4% by weight of initiator and 19 to 73.2% by weight of acrylic monomer resin. And slowly add 2.3 to 8% by weight of styrene or 5.9 to 14.2% by weight of divinylbenzene and 0.06 to 0.1% by weight of surfactant for 1 hour, and then when the addition is complete, the solution is added at about 75 to 80 ° C. for 5 hours. It is a step of preparing an emulsion polymerization solution by maintaining and adjusting the solution to pH 9.0 to 9.5 by adding amine base.

When acrylic acid is less than 2.7 weight% in the above, a hydrophilic group becomes small in a polymer chain, and solid content becomes small. In other words, the proportion of the polymer in the emulsion solution becomes small, resulting in a thin coating thickness and poor workability. On the contrary, when the acrylic acid exceeds 5.5% by weight, there are too many hydrophilic groups in the polymer chain, resulting in poor water resistance and water resistance.

In the above, the initiator and the surfactant are the same as those used in step (a).

In addition, as the amine base, triethylamine, N, N'-dimethylethanolamine, N, N'-dimethylethanolamine, diethanolamine, etc. are suitable.

In addition, the acryl-type monomer resin is an acryl-type monomer resin of following formula (I).

Where R ₁ is H ₂ C═CH, H ₂ C═C—CH ₃ , H ₂ C═C—CH ₂ CH ₃ , H ₂ C═C—CH ₂ CH ₂ CH ₃ , H ₂ C═ C-CH ₂ CH (CH ₃ ) ₂ , CH ₃ -CH = CH, CH ₃ CH ₂ -CH = CH, CH ₃ CH ₂ CH ₂ -CH = CH, CH ₃ CH ₂ = C-CH ₃ , CH ₃ CH ₂ = C-CH ₂ CH ₃ , CH ₃ CH ₂ = C-CH ₂ CH ₂ CH ₃ or CH ₃ CH ₂ = C-CH ₂ CH (CH ₃ ) ₂ , R ₂ is CH ₃ , CH ₂ CH ₃ , CH ₂ CH ₂ CH ₂ CH ₃ , CH ₂ CH ₂ CH ₃ , CH ₂ CH (CH ₃ ) ₂ , C (CH ₃ ) ₃ , CH ₂ C (CH ₃ ) ₃ , CH ₂ CH _2- 0-CH ₃ or CH ₂ CH ₂ -0-CH ₂ CH _{3 It} is selected.)

Subsequently, in step (c) of the present invention, about 20 to 40% by weight of silicate (Silicate-0) is added to the emulsion polymerization solution obtained in step (b) and stirred for 30 minutes, and the silane coupling agent is added to the entire solution. After the addition of 1 to 10% by weight is maintained for 2 hours at 80 ℃, 1 to 10% by weight of the lubricant is added and stirred for 1 hour.

If the amount of the silicate (Silicate-0) is 40% by weight or more, the degree of immersion in water increases and worsens, and the resistance to alkalis and drugs is weak. On the contrary, when it is less than 20 weight%, adhesiveness with a steel plate will worsen, and a lifting phenomenon will appear by an impact.

In the above, a silane coupling agent uses Dongyang Silicon Co., Ltd. product (brand name, TSL 8350, 8355). The use of the silane coupling agent as described above is an additive to be included in the organic coating material coated on the steel sheet because it exhibits a great effect on the modification of the organic-inorganic composite material, that is, the mechanical strength, the water resistance, and the like.

In addition, as the lubricant in the above, the brand name RV 50 (manufactured by Hawthorne Co., Ltd.) and / or the brand name Dipsol # 424 (manufactured by Japan Dipsol Co.). Wherein RV 50 consists of a mixture of polyol acrylate and surfactant, Dipsol # 424 is 40% trialkyl glyceride, 40% dibasic acid alkylate, 10% POE alkyl ether, 5% POE alkyl phenyl ether and others It is a mixture consisting of 5%.

In addition, the present invention is a polymerization molar ratio of acrylic acid: methacrylate: ethyl acrylate or n-butyl acrylate: styrene or divinyl benzene produced by the above production method is 0.5 to 1: 5 to 15: 0.5 to 1, A liquid resin composition for a steel sheet organic coating comprising an emulsion polymerization solution having an aqueous phase of 70 to 80% by weight, 20 to 40% by weight silicate, and 1 to 10% by weight of a silane coupling agent and a lubricant relative to the emulsion polymerization solution.

The polymerization molar ratio of acrylic acid: methacrylate: ethylacrylate or n-butylacrylate: styrene or divinylbenzene in the above is 1: 10: 10: 1.

Hereinafter, the present invention will be described in detail by way of examples.

Example 1

300 mL of water (tertiary distilled water) and 0.15 g of ammonium sulfate as an initiator were added to a four-neck circular or cylindrical reactor equipped with a stirrer, a cooler, a nitrogen inleter, a thermometer, and a dropping funnel, and stirred at 70 to 80 ° C. for 30 minutes with stirring. Maintained. 1.44 g of acrylic acid and 50 mL of water were added to the dropping funnel, and then slowly added dropwise into the four-necked reactor for about 30 minutes. Subsequently, 0.15 g of ammonium sulfate, 20 g of methyl methacrylate, 25.6 g of n-butyl acrylate, 2.1 g of styrene, and 0.05 g of a surfactant (SLS) were added to the dropping funnel, and slowly added dropwise into the reactor for about 1 hour. , Was maintained at 75 to 80 ° C for 5 hours. Thereafter, triethylamine was added so that the pH of the solution was 9.0, thereby preparing a dark milky emulsion polymerization solution.

Subsequently, 20 wt% of the silicate was added to the emulsion polymerization solution, followed by stirring for 30 minutes. Then, 2 wt% of TSL 8350 was added with a silane coupling agent and maintained at 80 ° C. for 2 hours. Subsequently, 2 wt% of RV 50 was added as a lubricant and stirred for 1 hour to prepare a liquid resin composition for a steel sheet organic coating.

[Examples 2 to 8]

In the same manner as in Example 1, but the silicate, the silane coupling agent and the lubricant was added to the ingredients and amounts shown in Table 1 below to prepare a liquid resin composition for a steel sheet organic coating.

[Examples 9 to 10]

The same procedure as in Example 1 was carried out, except that 1.05 g of styrene was used, and a silicate, a silane coupling agent, and a lubricant were added in the amounts and amounts shown in Table 1 below to prepare a liquid resin composition for a steel sheet organic coating.

[Examples 11 to 12]

The same procedure as in Example 1 was carried out, except that 2.88 g of acrylic acid and 4.2 g of styrene were used, and the silicate, the silane coupling agent, and the lubricant were added in the amounts and amounts shown in Table 1 below to prepare a liquid resin composite for steel sheet organic coating. It was.

[Examples 13 to 14]

The same procedure as in Example 1 was carried out, except that 12.8 g of n-butyl acrylate was used, and a silicate, a silane coupling agent, and a lubricant were added in the amounts and amounts shown in Table 1 below to prepare a liquid resin composition for a steel sheet organic coating. .

[Examples 15 to 16]

The same procedure as in Example 1 was carried out, except that 10 g of methyl methacrylate, silicate, silane coupling agent, and lubricant were added in the ingredients and amounts shown in Table 1 below to prepare a liquid resin composition for steel sheet organic coating.

Example 17

Performed in the same manner as in Example 1, using 20 g of ethyl acrylate instead of n-butyl acrylate, and added the silicate, silane coupling agent and lubricant in the ingredients and amounts shown in Table 1 below, liquid resin for steel sheet organic coating The composition was prepared.

Example 18

In the same manner as in Example 1, except that 30 g of methyl methacrylate and 10 g of ethyl acrylate instead of n-butyl acrylate were added, and the silicate, silane coupling agent and lubricant were added in the components and amounts shown in Table 1 below. A liquid resin composition for steel sheet organic coating was prepared.

[Examples 19 to 26]

Performed in the same manner as in Example 1, except that 2.16 g of acrylic acid, 30 g of methyl methacrylate, 38.45 g of n-butyl acrylate, and 3.9 g of divinylbenzene instead of styrene, and the silicate silane coupling agent and lubricant were The liquid resin composition for organic coating steel plate was prepared by adding with the component and the quantity shown to.

[Examples 27 to 28]

Performed in the same manner as in Example 1, except that 4.32 g of acrylic acid, 30 g of methyl methacrylate, 38.45 g of n-butyl acrylate, and 7.8 g of divinylbenzene instead of styrene, and the silicate silane coupling agent and lubricant were The liquid resin composition for organic coating steel plate was prepared by adding with the component and the quantity shown to.

[Examples 29 to 30]

2.16 g of acrylic acid, 30 g of methyl methacrylate, 19.23 g of n-butyl acrylate and 7.8 g of divinylbenzene were used for styrene dicin, and the silicate, the silane coupling agent and the lubricant were prepared in the same manner as in Example 1. The liquid resin composition for steel plate organic coating was produced by adding in the component and the quantity shown in 1.

Example 31

2.16 g of acrylic acid, 30 g of methyl methacrylate, 30 g of ethyl acrylate in place of n-butyl acrylate, and 3.9 g of divinylbenzene in place of styrene, silicate, silane coupling agent and The lubricant was added in the amounts and amounts shown in Table 1 below to prepare a liquid resin composition for steel sheet organic coating.

Example 32

2.16 g of acrylic acid, 30 g of methyl methacrylate, 30 g of ethyl acrylate in place of n-butyl acrylate, and 11.7 g of divinylbenzene in place of styrene, silicate, silane coupling agent and The lubricant was added in the amounts and amounts shown in Table 1 below to prepare a liquid resin composition for steel sheet organic coating.

Example 33

Performed in the same manner as in Example 1, except that 30 g of methyl methacrylate and 12.8 g of n-butyl acrylate were used, and the silicate, silane coupling agent, and lubricant were added in the amounts and amounts shown in Table 1 below for the organic coating of the steel sheet. A liquid resin composition was prepared.

Example 34

Performed in the same manner as in Example 1, except that 2.16 g of acrylic acid, 45 g of methyl methacrylate, 19.23 g of n-butylacrylate, and 7.8 g of divinylbenzene instead of styrene, and the silicate, silane coupling agent and lubricant are The liquid resin composition for steel plate organic coating was produced by adding in the component and the quantity shown in 1.

Comparative Example 1

Performed in the same manner as in Example 1, using 20 g of ethyl acrylate instead of n-butyl acrylate, and added the silicate, silane coupling agent and lubricant in the ingredients and amounts shown in Table 1 below, liquid resin for steel sheet organic coating The composition was prepared.

Comparative Example 2

2.16 g of acrylic acid, 30 g of methyl methacrylate, 30 g of ethyl acrylate in place of n-butyl acrylate, and 3.9 g of divinylbenzene in place of styrene, silicate, silane coupling agent and The lubricant was added in the amounts and amounts shown in Table 1 below to prepare a liquid resin composition for steel sheet organic coating.

[Comparative Examples 3 to 4]

Performed in the same manner as in Example 1, except that 30 g of methyl methacrylate and 12.8 g of n-butyl acrylate were used, and the silicate, silane coupling agent, and lubricant were added in the amounts and amounts shown in Table 1 below. A dosage liquid resin composition was prepared.

[Comparative Examples 5 to 6]

Performed in the same manner as in Example 1, except that 2.16 g of acrylic acid, 45 g of methyl methacrylate, 19.23 g of n-butylacrylate, and 7.8 g of divinylbenzene in place of styrene, and the silicate, silane coupling agent and lubricant were The liquid resin composition for steel plate organic coating was produced by adding in the component and the quantity shown in 1.

[Performance test]

[Clad on steel sheet]

The liquid resin composition for organic coating of the steel sheet obtained in each example was coated on a steel sheet material (7 cm x 15 cm) using a specially prepared roll coater, and dried in an oven at a temperature of about 200 ° C. for 8 to 10 seconds. Coating was carried out to 12 탆.

[Water Resistance Test]

Each steel sheet coated with the liquid resin composition obtained in each example was immersed in water for 24 hours, and determined to the extent of being submerged. The results are shown in Table 2 below. In other words, when the coated steel sheet is immersed in water, it becomes cloudy with poor transparency. The evaluation criteria of the water resistance test column of the following Table 2 are expressed as ◎: no splatter at all (very good), ○; slight immersion phenomenon, △; peeling about 50%, ×; 100% immersion.

[Alkali Resistance Test]

Each steel sheet coated with the liquid resin composition obtained in each example was boiled in a solution prepared with sodium phosphate and sodium hydroxide (pH = 12) for 30 minutes, and then peeling of the coating was observed by an electron microscope. It judged and the result is shown in following Table 2. (◎: No peeling phenomenon, (circle); less than 10% peeling, (triangle | delta); peeling about 50%, x; peeling more than 80%)

[Chemical Resistance Test]

Each steel sheet coated with the liquid resin composition obtained in each example was put into acetone for 30 minutes, and then vibrated with a sonicator to determine the degree of coating tolerability by an electron microscope. The results are shown in Table 2 below. ◎: No abnormality, ○; About 20% more than 30%, △; About 50% more than 70%, ×; More than 80% more than

Corrosion Resistance Test

Each steel sheet coated with the liquid resin composition obtained in each example was sprayed with 5% brine, and the initial white rusting time was measured. The result is shown in the following Table 2. (◎: 100 hours or more, (circle); 100-80 hours, (triangle | delta); 80-70 hours, x; 70 hours or less)

[Watertight Adhesion Test]

Each steel sheet coated with the liquid resin composition obtained in each example was placed in boiling water for 30 minutes, and then the degree of excitation between the steel sheet and the coating was determined by an electron microscope, and the results are shown in Table 2 below.

[Impact adhesion test]

Drop steel balls of a certain size onto each steel plate coated with the liquid resin composition obtained in each example at a height of 3 m, and adhere the scotch tape to the impact area. Observation of the result is shown in the following Table 2.

◎: Very good, ○: Good, △: Normal, ×: Poor

◎: Very good, ○: Good, △: Normal, ×: Poor

As shown in Table 2 above, it can be seen that the component ratio of the resin composition components is very important. More specifically, in the composition, styrene than divinylbenzene and ethyl acrylate than n-butyl acrylate showed good results in the performance test.

The most preferable composition ratio of the resin was the best performance test result when the molar ratio of acrylic acid: methyl methacrylate: ethyl acrylate or n-butyl acrylate: styrene = 1: 10: 10: 1, acrylic acid: methyl meth. The acrylate: ethyl acrylate or n-butyl acrylate: divinylbenzene = 1: 10: 10: 1 mole ratio also showed good results compared to the other ones.

In addition, when the content of silicate is 20 to 40% by weight, the performance was the best, and when it was 60 to 80% by weight, water resistance and water adhesion were not particularly good. In addition, when a large number of lubricants and silane coupling agents were used (particularly 10 parts by weight or more), the performance test results showed poor results.

In addition, when the silane coupling agent and the lubricant are not used at all in the present invention, a poor result was obtained regardless of the composition, which can be seen as an important factor in indicating the properties of the resin. Also, the three bases used to make the water-soluble resin did not show any difference in performance results.

Claims (5)

Method for producing a liquid resin composition for a steel sheet organic coating comprising the following steps (a), (b) and (c). (a) preparing a reaction solution by mixing water, an initiator and a surfactant, (b) adding 2.7-5.5 wt% of acrylic acid and 50 ml of water to the reaction solution for 30 minutes, and then 0.2-0.4 wt% of an initiator, 19 to 73.2% by weight of acrylic resin, 2.3 to 8% by weight of styrene or 5.9 to 14.2% by weight of divinylbenzene and 0.06 to 0.1% by weight of surfactant are added for 1 hour, and the solution is maintained at 75 to 80 ° C. for 5 hours. Adding an amine base to adjust the solution to pH 9.0 to 9.5 to prepare an emulsion polymerization solution, and (c) then adding about 20 to 40% by weight of silicate to the emulsion polymerization solution and stirring for 30 minutes. And, after adding 1 to 10% by weight of the silane coupling agent to the total solution for 2 hours at 80 ℃, and adding 1 to 10% by weight of the lubricant and stirring for 1 hour. The method of claim 1, wherein the initiator is benzoyl peroxide or ammonium persulfate. The method of claim 1, wherein the surfactant is sodium lauyl sulfate, and the amount of the additive is about 0.06 to 0.1% by weight. The method of claim 1, wherein the amine base is selected from triethylamine, N, N'-dimethylethanolamine or diethanolamine. The method according to claim 1, wherein the acrylic monomer resin of step (b) is an acrylic monomer resin of the following formula (I). Where R ₁ is H ₂ C═CH, H ₂ C═C—CH ₃ , H ₂ C═C—CH ₂ CH ₃ , H ₂ C═C—CH ₂ CH ₂ CH ₃ , H ₂ C═ C-CH ₂ CH (CH ₃ ) ₂ , CH ₃ -CH = CH, CH ₃ CH ₂ -CH = CH, CH ₃ CH ₂ CH ₂ -CH = CH, CH ₃ CH ₂ = C-CH ₃ , CH ₃ CH ₂ = C-CH ₂ CH ₃ , CH ₃ CH ₂ = C-CH ₂ CH ₂ CH ₃ or CH ₃ CH ₂ = C-CH ₂ CH (CH ₃ ) ₂ , R ₂ is CH ₃ , CH ₂ CH ₃ , CH ₂ CH ₂ CH ₂ CH ₃ , CH ₂ CH ₂ CH ₃ , CH ₂ CH (CH ₃ ) ₂ , C (CH ₃ ) ₃ , CH ₂ C (CH ₃ ) ₃ , CH ₂ CH _2- 0-CH ₃ or CH ₂ CH ₂ -0-CH ₂ CH _{3 It} is selected.)