KR100741567B1 - Surface-conditioning compositions containing manganese hydrogen phosphate hydrate and their manufacturing methods - Google Patents

Abstract

A water-dispersed Mn-based surface treating composition is provided to reduce sludge waste generated, improve film growth characteristics on precisely processed micro-flection portions, uniformize the particle size of a manganese phosphate film crystal, and allow the manganese phosphate film crystal to be grown in a micro-size range. A water-dispersed Mn-based surface conditioning composition is characterized in that manganese hydrogen phosphate hydrate(MnHPO4.2.25H2O) with an average particle size range of 0.03 to 0.8 mum is dispersed into a liquid phase medium containing an anionic surfactant and water. A particle size distribution of 1 mum or more has a fraction of less than 10% in the manganese hydrogen phosphate hydrate(MnHPO4.2.25H2O). The manganese hydrogen phosphate hydrate(MnHPO4.2.25H2O) is milled by a wet process. The manganese hydrogen phosphate hydrate(MnHPO4.2.25H2O) is contained in the composition in an amount of 0.1 to 55 wt.% based on the total composition weight. The anionic surfactant is contained in the composition in an amount of 0.05 to 5 wt.% based on the total composition weight. The composition further comprises 0.1 to 30 wt.% of an acid.

Description

Surface-conditioning Compositions Containing Manganese Hydrogen Phosphate Hydrate and Their Manufacturing Methods

1 is an electron microscope (SEM) photograph of a manganese phosphate encapsulation process treated specimen (Comparative Example 1) in which the surface adjustment process is omitted.

FIG. 2 is a SEM photograph of a manganese phosphate coating process specimen (Comparative Example 2) after a powder manganese-based surface adjustment treatment.

Figure 3 is a SEM photograph of the manganese phosphate crystalline coating grown after the water dispersion surface adjustment composition treatment according to Example 1 of the present invention.

Figure 4 is a SEM photograph of the manganese phosphate crystalline coating grown after the water dispersion surface adjustment composition treatment according to Example 2 of the present invention.

5 is a SEM photograph of a manganese phosphate coating formed after the surface adjustment composition treatment according to Example 3 of the present invention at a high bending surface.

The present invention relates to a water-dispersible manganese-based surface adjustment composition.

The surface treatment process for suppressing the corrosion of the ferrous metal includes a series of process steps such as degreasing, washing with water, drying, adjusting the surface, coating, washing with water, and rust prevention. In addition, the iron surface is plated to prevent corrosion of the iron metal. However, in recent years, as chromium plating is regulated, corrosion inhibiting surface treatment technology having similar performance is required in related markets.

Thus, as a method of suppressing or preventing corrosion of the iron surface, a method of generating a phosphate film on the surface of the iron metal was introduced, and a manganese phosphate film or zinc phosphate film was mainly formed during the phosphate film.

In order to grow the manganese phosphate film or zinc phosphate film on the iron surface densely and show reliable corrosion resistance after the rust prevention process, the film crystals must be grown in a macroscopic homogeneous state and microscopically uniform domain ( The film must be grown in a controlled environment to have a domain or grain size.

For this purpose, a surface modifier or surface conditioner is used in the pretreatment step of the film forming process.

Meanwhile, manganese-based surface modifiers are powder-like products having a wide particle size range through a mechanical crushing process such as a jet mill, which deposits various types of phosphate deposits including manganese, and grows manganese phosphate coatings densely. It is designed to suppress excessive growth in the thickness direction of the film.

The final powder, which has undergone mechanical crushing, exhibits an average particle diameter and a wide particle size range of several microns to several tens of microns. From the viewpoint of acting as a nucleus in the formation of manganese phosphate coating, the particle size range is wide and the surface adjustment process is performed. The process utilization efficiency of the surface modifier added to the reactor becomes very low, and most of the surface modifier material added is released in the form of process wastewater or process waste sludge. In addition, since the particle size range is very wide, the nonuniformity is very large in terms of the size of the crystal film starting nucleus formed on the surface, which may negatively influence the induction of uniform crystalline film growth, which is the original purpose of the surface modifier.

In the conventional conventional surface adjustment process, it is known that in the case of powdered manganese-based surface control agent, 0.1 to 1% by weight of solid content is added to the surface adjustment process immersion liquid to form a relatively uniform manganese phosphate coating by surface adjustment. In addition, it is generally known that the grain size of the manganese phosphate coating due to the addition of the powdered manganese-based surface conditioner is also largely about 1 to 10 µm.

 As described above, conventional surface modifiers and application techniques of surface modifiers, despite the excessive use of the active ingredient, it is difficult to expect the effect of extremely fine surface adjustment is very limited in the utility of precisely processed surface and the input of excessive amount As a result, the burden of environmental treatment is increased, and as a result, the process cost of the entire process is unnecessarily increased and economical efficiency is lowered.

Accordingly, the inventors of the present invention have made efforts to solve the shortcomings in the crystal characteristics of the conventional manganese-based surface modifiers and the use of the manganese phosphate film formed by the use, as a result, manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) was wet-pulverized and nanosized, and then a small amount of manganese modifier was used when a water dispersion composition uniformly dispersed in an aqueous solution medium containing a surfactant was used in the pretreatment step of the manganese phosphate coating process. The present invention has been found to enable efficient nucleation and to induce the growth of uniform manganese phosphate coating crystals.

Therefore, the present invention can reduce the sludge waste generated, improve the film growth characteristics for the fine bending precision processing portion, and uniformize the particle size of the manganese phosphate coating crystals, and the size range of the manganese phosphate coating crystals is fine It is an object of the present invention to provide a water-dispersed manganese-based surface treatment composition exhibiting an effect of growing quickly.

The present invention relates to a water-dispersed manganese surface in which manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) having an average particle diameter of 0.03 to 0.8 μm is dispersed in a liquid medium containing an anionic surfactant and water. It is characterized by the adjustment composition.

Hereinafter, the present invention will be described in detail.

The present invention provides a water-dispersed manganese-based surface control composition in which nano-sized manganese phosphate hydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) is uniformly dispersed in an aqueous medium containing a certain amount of a surfactant. When used in the pretreatment stage of the manganese phosphate coating process, it enables efficient nucleation using only a small amount, and can improve the particle size, film density, and uniformity of the manganese phosphate crystals growing on the iron surface. You can expect the effect.

Hereinafter, the water-dispersed manganese-based surface adjustment composition of the present invention will be described in detail for each component.

The water-dispersed manganese-based surface adjustment composition of the present invention comprises manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) having an average particle diameter of 0.03 to 0.8 μm.

In order to nano-disperse the above manganese phosphate hydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate), the synthesized and dried powder is mixed in a liquid medium and wet-pulverized, whereby a surfactant is used as a dispersant. Mix. By selecting the above-mentioned wet pulverization, it is possible to obtain characteristics such as fine pulverization and reaggregation prevention, and homogeneous dispersion in a liquid medium, unlike various kinds of dry pulverization methods.

The wet milling process may be subjected to single stage milling or multistage milling, and may include attrition mills, disc-and-bead mills and pin mills. Grinding equipment such as a pin mill can be used for the wet grinding process by single use or combination use. That is, in the present invention, the pulverizing step may be performed by applying any process operation method such as one step, multi-step, circulating type, and the like to the type of pulverized crushing device used in the pulverizing. There is no limit.

However, the final finely pulverized manganese phosphate hydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) may be adjusted to have an average particle size of 0.03 to 0.8 μm, preferably 0.6 μm or less, in which case the average If the particle size is larger than 0.8 μm, it is difficult to secure dispersion stability using dispersants that are harmless to the manganese phosphate coating process. In addition, in the aspect of particle size distribution of manganese phosphate dihydrate (MnHPO ₄ · 2.5H ₂ O), adjusting to make the fraction of particle size distribution of 1 μm or more is less than 10% to secure long-term dispersion stability and uniformity and tightness of the final formed phosphate film. It is preferable from the side.

Manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) is 0.1 to 55% by weight, preferably 0.2 to 30% by weight, more preferably 0.4 to 0.4% by weight, based on the solid content of the composition. 15 weight percent. When the content of the manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) is maintained below 0.1% by weight, surface adjustment, that is, nucleation-inducing effect is insignificant, on the contrary, exceeds 55% by weight When supplied, excessive nucleation can result in too large a crystal's longitudinal aspect ratio, resulting in weak mechanical strength, and excess manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate). This is a by-product and discarded. In addition, since the types and amounts of surfactants that can be used by the subsequent coating process are strictly restricted, it is also difficult to secure long-term storage stability of the product by increasing the solid content.

On the other hand, the effect of surface adjustment significantly affects the population of nuclei and the direction of crystal growth. The manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese) is controlled and used as described above. Hydrogen Phosphate Hydrate) allows the control of the number of nuclei.

The water-dispersed manganese-based surface adjustment composition of the present invention is a nano-dispersed manganese phosphate hydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) in a liquid medium.

In this case, the liquid medium is a dispersant which is a kind of surfactant when it is desired to improve long-term dispersibility of manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) and to increase solid content. A small amount can also be added.

However, as mentioned above, the use of such dispersants is subject to constraints, and the range of choice is very narrowly limited since the subsequent encapsulation process may be affected by the dispersant.

Accordingly, in the present invention, anionic surfactant is selected and used as the dispersant in view of the dispersion stability of the manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) and the formation of manganese phosphate coating. do. As the anionic surfactant, those containing one or two or more functional groups selected from carboxylic acid groups and carboxylic acid salts are used. At this time, it was observed that the use of cationic surfactant negatively affects the formation of fine and dense manganese phosphate coating, or induce gelation in the long-term use of the process immersion liquid, and in the case of using a nonionic surfactant It tends to slow the growth rate of manganese phosphate coatings or to lead to incomplete coating formation or to be poor in efficacy as a dispersant.

However, by using an anionic surfactant as in the case of the present invention, it is possible to ensure long-term dispersion stability of the composition without affecting dense growth of the target manganese phosphate microfilm.

The anionic surfactant may be used in an amount of 0.05 to 5% by weight of the total composition, preferably 0.1 to 3% by weight. At this time, when the amount of the anionic surfactant is less than 0.05% by weight, the effective dispersion stability of the manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) cannot be expected, and the amount is more than 5% by weight. If the surfactant is excessively adhered to the surface of the process object to be processed depending on the nature of the surfactant can be kinematically and morphologically affect the growth of the manganese phosphate coating.

As described above, the water-dispersed manganese-based surface adjustment composition of the present invention uses water containing an anionic surfactant as a liquid medium, and the manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen) having a certain size therein. Phosphate Hydrate) is nano-dispersed.

On the other hand, the water-dispersible manganese-based surface adjustment composition of the present invention may further include an acid (acid). The use of these acids makes it easier to control the direction of crystal growth. That is, the dispersion medium of manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate), which is a surface modifier, is not necessarily pure water.

As the acid, pyrophosphoric acid, phosphoric acid, monophosphoric acid, or diphosphoric acid may be selected and used. The amount of acid may be used in an amount of 0.1 to 30% by weight, preferably 1 to 10% by weight, in the total composition. At this time, if the amount of use exceeds 30% by weight, it may be a change in appearance, such as color due to a very slow chemical alteration reaction in the solids and surfactant added during long-term storage.

In addition to the acid, it is apparent that the water-dispersible manganese-based surface adjustment composition of the present invention may additionally use functional additives commonly used in the art by the choice of those skilled in the art within the scope of not impairing the object of the present invention.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

Comparative example  One

The surface of the carbon steel specimen was degreased, washed with water and pickled with 17% hydrochloric acid, and the manganese phosphate coating was grown directly without adding any surface conditioner. A scanning electron microscope photograph of the grown manganese phosphate coating specimen is shown in FIG. 1.

As shown in FIG. 1, it can be seen that an amorphous manganese phosphate coating body having no regularity is formed on the surface.

Comparative example  2

Using manganese phosphate hydrate powder, the carbon steel surface was subjected to degreasing, washing with water, and pickling as in Comparative Example 1, followed by surface adjustment treatment. At this time, 0.3 wt% manganese phosphate dihydrate powder and 0.3 wt% pyrophosphate were mixed with water as a surface conditioner. After soaking the pretreated carbon steel specimen in the surface adjustment liquid thus prepared, a film forming process was performed to form a crystalline manganese phosphate coating, and a scanning electron micrograph of the obtained treated specimen was shown in FIG. 2.

As shown in FIG. 2, the morphology structure of the manganese phosphate film finally formed by the surface adjustment process is greatly changed, and the formation of crystalline grains is microscopically uniformed, and the film formation is more dense. Can be.

Example  One

As a dispersant, 4.5 wt% of manganese phosphate dihydrate was dispersed in an aqueous solution containing 0.45 wt% of a polycarboxylic acid type product (Sanoff Co., HS-dispersant 5801). The average particle size of manganese phosphate hydrate was about 300 nm as measured by the light scattering method, and the particle size distribution was less than 10%.

Instead of the manganese phosphate hydrate powder of Comparative Example 2, a surface adjustment process was performed using a surface modifier composition obtained by nano-dispersing the manganese phosphate hydrate prepared above, followed by a manganese phosphate coating process.

A scanning electron micrograph of a manganese phosphate encapsulation process specimen prepared using the same is shown in FIG. 3.

As shown in FIG. 3, it can be seen that a homogeneous crystalline manganese phosphate coating of about 0.5 μm was formed.

Example  2

As a dispersant, 0.6 wt% of manganese phosphate dihydrate was dispersed in an aqueous solution containing 0.06 wt% of a polycarboxylic acid type product (Sanoff Co., HS-dispersant 2026S). The average particle size of manganese phosphate hydrate was about 400 nm as measured by the light scattering method, and the particle size distribution was less than 10%.

Using the composition, a manganese phosphate coating was grown on the surface of the carbon steel in the same manner as in Example 1.

A scanning electron micrograph of a manganese phosphate encapsulation process specimen prepared using the same is shown in FIG. 4.

As shown in FIG. 4, it can be seen that a homogeneous crystalline manganese phosphate coating of about 0.5 μm was formed.

That is, it was confirmed that even if a very small amount of surface-adjusting active substance is added, the desired manganese phosphate coating can induce crystal growth finely and precisely.

Example  3

The manganese phosphate coating was grown by applying the experiment of Example 1 to a fine bolt made of carbon steel with high bend. The result of observing the angled surface of the edge of the bolt head at low magnification with a scanning electron microscope is shown in FIG. 5.

As shown in FIG. 5, it was confirmed that a very dense microcrystalline coating body was formed.

Example  4

4.5 wt% of pyrophosphate was mixed with the surface modifier composition of Example 1 to prepare a new composition, which was left at room temperature for 1 month. It was confirmed that the dispersed phase remained stable without precipitation phenomenon, and manganese phosphate coating experiment was performed using this.

As a result, it was confirmed that a manganese phosphate coating film was formed in a uniform and dense fine crystal form similar to Example 1.

As described above, according to the present invention, the particle size of the manganese phosphate coating crystal can be made uniform, and its size range can be induced to be finely grown to 0.3 to 1 μm, and even for fine bending precision processing parts having a complex structure. Since the manganese phosphate film can be grown, anti-rust treatment after the manganese phosphate film can be grown to give improved performance in terms of corrosion resistance, durability, and weather resistance.

In addition, it is possible to improve the participation efficiency of the crystal growth of the manganese phosphate dianhydride hydrate surface treatment agent can be expected to have an additional effect to reduce the sludge waste generated.

Claims (9)

Manganese phosphate dihydrate (MnHPO ₄ .2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) with an average particle diameter ranging from 0.03 to 0.8 μm is dispersed in a liquid medium containing an anionic surfactant and water. Surface modulating composition. The method of claim 1, wherein the manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) is a water-dispersed manganese-based surface adjustment composition, characterized in that the fraction of the particle size distribution of 1㎛ or more less than 10%. The method of claim 1, wherein the manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) is a water-dispersed manganese-based surface adjustment composition, characterized in that the wet grinding. The method of claim 1, wherein the manganese phosphate dihydrate (MnHPO ₄ · 2.25H ₂ O, Manganese Hydrogen Phosphate Hydrate) is a water-dispersed manganese-based surface adjustment composition, characterized in that containing 0.1 to 55% by weight of the total composition. The water-dispersible manganese-based surface adjustment composition according to claim 1, wherein the anionic surfactant contains one or two or more functional groups selected from carboxylic acid groups and carboxylic acid salts. The water-dispersible manganese-based surface adjustment composition according to claim 1, wherein the anionic surfactant comprises 0.05 to 5% by weight of the total composition. The water dispersion type manganese-based surface adjustment composition according to claim 1, further comprising an acid in the whole composition. 8. The water dispersion-type manganese-based surface adjustment composition according to claim 7, wherein the acid is one or a mixture of two or more selected from pyrophosphoric acid, phosphoric acid, nitrate phosphoric acid and diphosphoric acid. The water dispersion type manganese-based surface adjustment composition according to claim 7 or 8, wherein the acid is included in the range of 0.1 to 30% by weight in the total composition.

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