KR102103537B1 - Funtional coating material - Google Patents

Abstract

The present invention relates to a functional coating agent consisting of a main agent and a curing agent, wherein the main agent comprises: a bisphenol A type epoxy resin; a bisphenol F type epoxy resin; alkyl glycidyl ether; propylene glycol monomethyl ether acetic acid; micaceous iron oxide; and titanium dioxide.

Description

Functional coating agent {FUNTIONAL COATING MATERIAL}

The present invention relates to a functional coating agent, and more particularly, to a highly functional coating agent capable of coating on a surface with moisture.

Often, coatings (paints), called paints, are often thought of as being painted to color. However, coatings (paints) are, in fact, representative chemical products with advanced science and technology.

Covering the surface of an object to protect and beautify the object includes not only a coating agent (paint), but also plating, wallpaper, and tiles. However, the difference between the coating material (paint) and this material is that it is simple and easy to coat the surface of an object, and it is free and economical to renew the film. In addition, since the coating agent (paint) is easy to coat by a method other than brush painting and is a fluid, it has the ability to form a coating film by attaching it to an object. It has the characteristics of being stable on the surface to achieve the purpose of protecting and plastering objects.

In the 21st century, research is deeply conducted in three directions such as convergence and limiting intelligence, and it is not just a simple coating technology using conventional general-purpose polymers, but also improving functionality and physical properties through grafting with high-tech fields to become a new coating agent. Development is taking place.

The development of functional coatings increases the synergistic effect of shared growth through convergence and integration with other industries such as the offshore plant's painting industry, automobile, electrical / electronics, civil engineering / architecture, defense industry, medical, aviation, and cutting-edge nano, and creates a high value-added economy It is an industrial field required to develop into an industry. Functional coatings have been used in many fields for the purpose of preventing corrosion or abrasion on the surface, and recently, their usefulness has been expanded to have materials such as wear resistance, fire resistance, flame retardancy, antibacterial, heat dissipation, stealth function, and electromagnetic shielding. In recent years, with the development of coating and coating technology, it is possible to advance the surface function of the object, and various basic functions such as abrasion resistance and corrosion resistance, optical functions, electrical functions, electronic functions, mechanical functions, physical / chemical functions, etc. And by adding new functions, it contributes to the high added value of the products to be painted.

One of the common considerations in existing surface coatings is surface treatment and residual humidity management. It is the control of humidity to prevent the formation of dew point on the metal surface. When a wet or moisture surface is formed on the metal surface, a phenomenon occurs in which the metal base surface and the coating layer are peeled off by the moisture surface. Therefore, it is very important in the surface coating that the moisture (Wet or Moisture) surface is not formed on the metal surface so that there is no peeling phenomenon due to moisture between the metal base material and the multiple coating layers such as the coating layer or the primary coating layer and the secondary coating layer. It was a problem.

Accordingly, almost all of the existing coating agents are designed to be installed under an environment in which no moisture surface is generated by limiting relative humidity, dew point, and weather conditions so as not to be coated on the wet surface. Moisture cotton is required to pay special attention because it seriously damages the coated surface, and in the meantime, this was a basic familiarity in the same industry, and recognition was established enough to be taken for granted.

When using these existing coatings, there was a problem in that the coating period was impossible in rainy weather and the construction period was prolonged.Dew condensation phenomenon, such as underground facilities or piping outside, placed in a water vapor environment such as an underground rehabilitation pipe There was a problem that was difficult to apply even in frequent places.

In addition, in the case of the existing coating agent, since it is difficult to install on the water surface, it is difficult to use the surface treatment method by washing with high pressure water among the surface treatment methods, and it is necessary to use the abrasive blasting surface treatment method that mechanically performs the surface treatment using abrasives. Did. However, in the case of the abrasive blasting surface treatment method, environmental facilities such as dust collectors that collect various essential equipment and dust generated during work are required, and the used abrasives must be collected and treated separately as industrial waste, so additional equipment cost, industry There is a disadvantage in that the process cost is very high due to the waste treatment cost, etc., and it is difficult to apply to a place where various facilities are difficult to install. On the other hand, in the case of the surface treatment method by washing with high pressure water, the surface is washed by applying a certain pressure with water, so, unlike abrasive blasting, it is eco-friendly, has relatively simple necessary equipment, and has very little residue, so there is no separate industrial waste treatment. In addition, the economic time can be expected because the process time is very short and the process cost is remarkably small. However, since the existing coating agent adversely affects the adhesion between the metal surface and the coating agent due to moisture remaining after the surface treatment, the metal surface had to be sufficiently dried, so there was a problem that the advantage of the surface treatment method by washing with high pressure water could not be maximized. .

If there is a coating agent that can be directly coated on the moisture side, it can be coated even in environments with many water vapors or frequent dew condensation, and it is possible to shorten process time and reduce process cost by surface treatment by washing with high pressure water. Because of this, there are many advantages, but the existing coatings have a remarkable drop in adhesive strength on the surface with moisture, and thus the coating layer has been peeled off. Therefore, it is urgent to develop a functional coating that can provide sufficient adhesive strength even on the surface with moisture. In the coating industry, it is judged that it has utility as a coating agent when the adhesion strength is at least 3 MPa, and when the adhesion strength is 5 MPa or more, it is judged to have sufficient adhesive strength as a coating agent, but the existing coating agent adheres itself to the surface with moisture. Even if it was impossible or adhered, it was a problem because the adhesion strength was mostly less than 1 MPa.

[Patent Document 1] Korean Patent Publication No. 10-2006-0111825

The present invention aims to provide an eco-friendly functional coating agent that can be applied to a surface containing moisture and can be coated and cured at room temperature by solving the problems of the existing coating agent, and specifically, for a surface containing moisture. It is an object to provide a functional coating agent having an adhesive strength of at least 3 MPa or more.

As a means for solving the above problems, the present invention is a functional coating agent consisting of a subject and a curing agent, the subject is a bisphenol A type epoxy resin; Bisphenol F type epoxy resin; Alkyl glycidyl ether; Propylene glycol monomethyl ether acetic acid; Mica phase iron oxide; And titanium dioxide.

The curing agent is benzyl alcohol; Isophorone diamine; Meta-xylene-alpha, alpha-diamine; And salicylic acid.

The subject is 10 to 15 parts by weight of the bisphenol A type epoxy resin; Bisphenol F type epoxy resin is 6 to 7 parts by weight; Alkyl glycidyl ether is 6 to 7 parts by weight; The propylene glycol monomethyl ether acetic acid is 0.25 to 0.28 parts by weight; And the mica-like iron oxide is 64 to 66 parts by weight; The titanium dioxide may be characterized by consisting of 6 to 7 parts by weight ;.

The curing agent is 35 to 45 parts by weight of the benzyl alcohol; 20 to 30 parts by weight of the isophorone diamine; 20 to 30 parts by weight of the meta-xylene-alpha, alpha-diamine; And 5 to 15 parts by weight of the salicylic acid; may be characterized by consisting of.

According to the functional coating agent according to an embodiment of the present invention, it can be coated directly in the presence of moisture even in an environment with a lot of water vapor or dew condensation, such as rainy weather or underground facilities, so the scope of application becomes broad and the coating construction time There is also an effect that can be shortened.

In addition, according to the functional coating agent according to the embodiment of the present invention, even when the surface to be coated is treated, the coating treatment can be immediately performed with the functional coating agent according to the embodiment of the present invention after the surface treatment method is performed by washing with high pressure water. Therefore, there is no need to perform an expensive abrasive blasting surface treatment method, thereby reducing the process cost and reducing the process time.

In addition, in the case of the functional coating agent according to the embodiment of the present invention, it is made of 100% solid content of a solvent-free type (VOC's Free), thereby being eco-friendly and improving work safety.

1 shows the structure of a bisphenol A type epoxy resin.
Figure 2 shows the structure of the bisphenol F type epoxy resin.
Figure 3 shows the structure and product picture of the alkyl glycidyl ether.
4 shows the structure and product picture of propylene glycol monomethyl ether acetic acid.
5 shows the structure and product picture of benzyl alcohol.
Figure 6 shows the structure and product pictures of isophorone diamine.
7 shows the structure and product picture of meta-xylene-alpha, alpha-diamine.
8 shows the structure and product photos of salicylic acid.
9 shows an embodiment of a paste mixer.

Hereinafter, according to the embodiment of the present invention, the present invention will be described in more detail. The following examples are intended to illustrate preferred embodiments of the invention to those of ordinary skill in the art to understand and easily practice the invention, and should not be construed as limiting the invention. Those skilled in the art will recognize that various changes and modifications are possible within the scope and spirit of the present invention.

Functional coating agent according to an embodiment of the present invention is composed of a subject and a curing agent, subject is a bisphenol A type epoxy resin; Bisphenol F type epoxy resin; Alkyl glycidyl ether; Propylene glycol monomethyl ether acetic acid; Mica phase iron oxide; And titanium dioxide, and the curing agent is benzyl alcohol; Isophorone diamine; Meta-xylene-alpha, alpha-diamine; And salicylic acid.

Epoxy resin (bisphenol A type epoxy resin; bisphenol F type epoxy resin)

Epoxy is defined as a crosslinked polymer having a crosslinking reaction caused by the reaction of an epoxy group. It is a resinous material having two or more epoxy groups in the molecule and a thermosetting resin produced by polymerization of the epoxy group. The epoxy resin has a specific gravity of 1.230 to 1.189, and has excellent mechanical properties such as bending strength and hardness. There is no generation of volatile substances and shrinkage of volume during curing, and a large adhesion to the material surface when curing. It has high flammability and chemical resistance, but is slightly eroded by strong acids and strong bases. The pigment can be freely colored by adding a pigment, and also has a high light resistance. The maximum operating temperature of the product is as low as 80 degrees Celsius. It shows excellent processability such as mold, purchase and sealing.

-Bisphenol A type epoxy resin

Bisphenol A type epoxy resin is used in general electrical, electronic and electronic, adhesives, civil construction paints, and anticorrosive materials, and the structure of the bisphenol A type epoxy resin is shown in FIG. 1. Bisphenol A type epoxy resins i) can obtain various properties depending on the type of curing agent and modifier, ii) less curing shrinkage than other thermosetting resins, iii) excellent toughness and high temperature characteristics, iv) chemical resistance And excellent water resistance, v). The Ether bond is rotatable and has plasticity, vi) It has the advantage of great adhesion due to the regularity of hydroxyl groups and hydrocarbons. The bisphenol A type epoxy resin may contribute to the functional coating agent exhibiting superior adhesive performance at a content of 10 to 15% by weight, and if it is contained in too much or too little outside, it may rather degrade the adhesive performance of the functional coating agent. have.

-Bisphenol F type epoxy resin

The bisphenol F-type epoxy resin exhibits low viscosity and high adhesion properties compared to the bisphenol A-type epoxy resin. Therefore, bisphenol F type epoxy resins are generally used where low viscosity or impregnation is required. The structure of the bisphenol F type epoxy resin is as shown in FIG. 2, and the cargo properties, crystallinity, compatibility, curing speed, and thermal stability are similar to those of the bisphenol A type epoxy resin, and low viscosity, high reactivity plasticity, and other resins. It has the advantage of excellent compatibility with.

The bisphenol A-type epoxy resin and the bisphenol F-type epoxy resin according to an embodiment of the present invention are all made of 100% solid-free solvent-free type (VOC's Free) resin, which is eco-friendly and improves work safety. The bisphenol F type epoxy resin may contribute to the functional coating agent exhibiting superior adhesive performance at a content of 6 to 7% by weight in the subject, and if it is contained in too much or too little outside, it may rather degrade the adhesive performance of the functional coating agent. .

Alkyl glycidyl ether

C12-C14 alkyl glycidyl ether is a reaction (reaction with curing agent) diluent, which lowers the viscosity of the diglycidyl ether of the bisphenol A type epoxy resin and exhibits an effect similar to benzene methanol. The structure of the alkyl glycidyl ether is shown in FIG. 3 (a), and the picture of the alkyl glycidyl ether product actually used is shown in FIG. 3 (b). Alkyl glycidyl ether may contribute to the superior coating performance of the functional coating agent at a content of 6 to 7% by weight, and if it is contained in too much or too little, the adhesive performance of the functional coating agent may be deteriorated. .

Propylene glycol monomethyl ether acetic acid

Propylene Glycol Monomethyl Ether Acetate (PMA) is an eco-friendly solvent used in electronic solvents such as photoresists and semiconductors, LCDs, industrial cleaners, paints, solvents for ink, adhesives, and various resins. The structure of propylene glycol monomethyl ether acetic acid is shown in (a), and a photo of the propylene glycol monomethyl ether acetic acid product actually used is shown in Fig. 4 (b). Propylene glycol monomethyl ether acetic acid may contribute to the functional coating agent exhibiting superior adhesive performance at a content of 0.25 to 0.28% by weight in the subject, and if it is contained in too much or too little outside, it may rather degrade the adhesive performance of the functional coating agent. have.

Micaceous Iron Oxide (MIO)

According to an embodiment of the present invention, an inorganic mica-like iron oxide is impregnated into the subject. MIO is a natural mineral obtained from hematite with a high content of Fe2O3, which provides rust resistance by shielding the penetration of moisture in a medium-corrosion coating. ) Is a flake with metallic luster. These flaky lamella particles are arranged parallel to the surface to have an effect of strengthening the coating film, as well as a barrier effect to block environmental factors such as moisture, salt, and ultraviolet rays. In the embodiment of the present invention, mica-like iron oxide powder having an average particle size of 100 μm was selected. MIO paints with MIO pigments increase the water resistance due to side-by-side stretching in the coating film because the pigment is flake, and the adhesion of the overlapping coating film is good by making the pigment come out of the surface and making a rough surface It has features such as no fear of interlayer peeling, that it can be painted thick, that the light reflection effect is large, and that it has high weather resistance. Mica phase iron oxide may contribute to the functional coating agent exhibiting superior adhesive performance at a content of 64 to 66 parts by weight of the subject, and if it is contained too much or too little outside, it may rather degrade the adhesive performance of the functional coating agent.

Titanium dioxide (TiO2)

According to an embodiment of the present invention, the inorganic titanium dioxide is impregnated into the subject. Titanium dioxide has a large hiding power, does not dissolve in almost all solvents, exhibits anisotropy with a very high refractive index, and has high scattering properties. Being a very stable material, it improves hiding power, weather resistance and discoloration resistance to heat and light. In this example, titanium dioxide powder having an average particle size of 0.36 µm was selected. Titanium dioxide may contribute to the superior coating performance of the functional coating agent at a content of 6 to 7% by weight, and if it is contained in too many or too little, the adhesive performance of the functional coating agent may be deteriorated.

Benzyl alcohol

Benzyl alcohol is an aromatic alcohol having a molecular weight of 108.14 with the formula C6H5CH2OH. It is a colorless, transparent liquid with a subtle, sweet smell. It has low water solubility and is almost decomposed in water and is easily dissolved in alcohol and ether. It reacts with acids such as acetic acid to produce ester compounds. 5 (a) shows the structure of benzyl alcohol, and FIG. 5 (b) shows a photo of an actual benzyl alcohol product. Benzyl alcohol may contribute to exhibit superior adhesive performance when the content in the curing agent is 35 to 45% by weight, and if it is contained in too much or too little outside, it may rather degrade the adhesive performance of the functional coating agent.

Isophorone diamine

Isophorone diamine is a curing agent for epoxy paints, and is a modified cycloaliphatic amine, which is composed of low viscosity and is used to improve workability. In particular, it reacts with an epoxy resin to form a coating film with excellent gloss, which is excellent in gloss stability and strong in chemical components such as acid and alkali, and is widely applied in places requiring chemical resistance, and has excellent physical and mechanical properties. The structure of isophorone diamine is shown in (a) of FIG. 6, and a photo of an isone diamine product actually used is shown in FIG. 6 (b). Isophorone diamine may contribute to the functional coating agent exhibiting superior adhesive performance at a content of 20 to 30% by weight in the curing agent, and if it is contained in too much or too little outside, it may rather degrade the adhesive performance of the functional coating agent.

Meta-xylene-alpha, alpha-diamine

Meta-xylene-alpha, alpha-diamine is excellent in water resistance and chemical resistance, and has a fast curing speed. For detailed use, it is used for epoxy flooring, epoxy heavy-duty coatings, wind turbine blades, etc., and may be used by adduction or mixing with other curing agents. The structure of meta-xylene-alpha and alpha-diamine is shown in (a) of FIG. 7, and the photo of meta-xylene-alpha and alpha-diamine products actually used is shown in FIG. 7 (b). Meta-xylene-alpha and alpha-diamine may contribute to the functional coating agent exhibiting superior adhesive performance at 20 to 30% by weight in the curing agent, and if it is contained in too much or too little, the adhesive performance of the functional coating agent is improved. It can decrease.

Salicylic acid

Salicylic acid corresponds to o-oxybenzoic acid, the formula C7H6O3. Molecular weight 138.12, melting point 159 degrees Celsius, specific gravity 1.443, sublimable, soluble in organic solvents such as ether or ethanol. The structure of salicylic acid is shown in FIG. 8 (a), and a picture of the salicylic acid product actually used is shown in FIG. 7 (b). Salicylic acid may contribute to the superior coating performance of the functional coating agent at a content of 5 to 15% by weight in the curing agent, and if it is contained in too much or too little, the adhesive performance of the functional coating agent may be deteriorated.

Mixing equipment

According to an embodiment of the present invention, a subject consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, alkyl glycidyl ether, propylene glycol monomethyl ether acetic acid, mica-like iron oxide, and titanium dioxide constituting the functional coating agent, and benzyl alcohol , A paste mixer was used to mix with a curing agent consisting of isophorone diamine, meta-xylene-alpha, alpha-diamine, and salicylic acid evenly dispersed. This is a high-viscosity mixed defoaming device that is designed to allow mixing and defoaming without internal impellers in existing mixing equipment using centrifugal force, centripetal force, and friction force by simultaneously driving revolution and rotation. 9 shows an embodiment of a paste mixer.

Each material is weighed according to a predetermined mixing ratio and mixed into a container for a paste mixer. In this case, salicylic acid does not dissolve well, so it is preferable to pre-mix with benzyl alcohol (Pre-Mix) and then mix it in a dedicated container of a paste mixer.

Formulation and experiment

First, the metal plates are prepared to sufficiently retain moisture by immersing several metal plates intentionally rusted in water in a tank for a long time.

Next, a functional coating agent is prepared by mixing the subject and the curing agent in a paste mixer at a mixing ratio as shown in the mixing ratios A, B, and C below. Since salicylic acid does not dissolve well, it is pre-mixed with benzyl alcohol (Pre-Mix) first, and then mixed into a dedicated container of the paste mixer. First, the speed (RPM) of the paste mixer is rotated at 500 for 1 minute, and then 2nd It was rotated at RPM 1000 for 30 seconds. When rotating and stirring too much time, the rotation time of the paste mixer was adjusted so that the mica phase iron oxide or titanium dioxide, which is an inorganic substance, may rub against the surface of the container and generate heat, so that it does not exceed the first 1 minute and the second 30 seconds. .

When the functional coating is prepared, the metal plates immersed in the water tank are taken out, the functional coating is immediately applied, and then cured at room temperature for 24 hours.

After curing for 24 hours, the adhesive strength was measured. The test standard for the adhesive strength was ASTM D 4541, and the testing organization was set by the Korea Research Institute of Chemical Fusion (KTR). In the coating industry, it is judged to have adhesive performance to the extent that it does not peel off the metal plate containing moisture only when the adhesive strength of at least 3 MPa is shown, and when the adhesive strength of 5 MPa or more appears to have excellent adhesive performance to the metal plate containing moisture. to be.

Mixing ratio A

-Mixing ratio of the subject

-Mixing ratio of curing agent

Mixing ratio B

-Mixing ratio of the subject

-Mixing ratio of curing agent

Mixing ratio C

-Mixing ratio of the subject

-Mixing ratio of curing agent

The results of the adhesive strength (ASTM D 4541) test of the functional coating agent conducted by the Korea Research Institute of Chemical Fusion (KTR) at the above mixing ratio are shown in Table 1 below.

Mixing ratio A Mixing ratio B Mixing ratio C Adhesive strength 3.5 MPa 4.5 MPa 5.5 MPa Eligibility Eligible Eligible Eligible

As shown in Table 1, in the case of the functional coating agents blended with the mixing ratios A, B, and C according to the embodiment of the present invention, they are cured at room temperature and all have an adhesive strength of 3 MPa or more against a rusty metal surface containing moisture. The adhesive performance was found to be excellent in the order of mixing ratio C, B, A. Accordingly, it has been proved that in the case of the functional coating agents formulated in the mixing ratios A, B, and C according to the embodiment of the present invention, there is an effective value as a coating agent for a metal surface containing moisture. Particularly, in the case of the functional coating agent of the present invention formulated at a compounding ratio C, it exhibits an adhesive strength of more than 5 MPa to a metal surface containing moisture, and thus has a remarkably excellent adhesive performance compared to the compounding ratios A and B.

Therefore, bisphenol A type epoxy resin; Bisphenol F type epoxy resin; Alkyl glycidyl ether; Propylene glycol monomethyl ether acetic acid; Mica phase iron oxide; And titanium dioxide, and benzyl alcohol; Isophorone diamine; Meta-xylene-alpha, alpha-diamine; And a functional coating agent according to an embodiment of the present invention consisting of a curing agent made of salicylic acid has an effect capable of sufficiently functioning as a coating agent even on a wet surface with moisture. In particular, the subject value of the functional coating agent according to an embodiment of the present invention is 10 to 15 parts by weight of the bisphenol A type epoxy resin; Bisphenol F type epoxy resin is 6 to 7 parts by weight; Alkyl glycidyl ether is 6 to 7 parts by weight; The propylene glycol monomethyl ether acetic acid is 0.25 to 0.28 parts by weight; And the mica-like iron oxide is 64 to 66 parts by weight; The titanium dioxide is composed of 6 to 7 parts by weight; curing agent is 35 to 45 parts by weight of the benzyl alcohol; 20 to 30 parts by weight of the isophorone diamine; 20 to 30 parts by weight of the meta-xylene-alpha, alpha-diamine; And 5 to 15 parts by weight of the salicylic acid; has the effect of exhibiting excellent adhesion strength in the case consisting of.

In addition, the functional coating agent of the compounding ratio C was measured by measuring the dry film thickness (DFT) whether the functional coating agent of the present invention cured through additional experiments was evenly applied. The measurement saturation is shown in Table 2 below.

As shown in Table 2 above, as a result of measuring the thickness of the dry film, the functional coating agent of the compounding ratio C shows an even thickness between 150 and 200 μm, and thus it is judged to have an even coating property.

As described above, according to the functional coating agent according to the embodiment of the present invention, the application range is possible because it can be coated directly in the presence of moisture even in environments with heavy water vapor or dew condensation, such as rainy weather or underground facilities. It has the effect of being broad and shortening the coating construction time. In addition, even in the case of treating the surface to be coated, after performing the surface treatment method by washing with high pressure water, it is possible to immediately apply the coating with the functional coating agent according to the embodiment of the present invention, thereby carrying out the expensive polishing blasting surface treatment method Since there is no need to do this, the process cost can be reduced and the process time can be shortened. In addition, in the case of the functional coating agent according to the embodiment of the present invention, it is made of 100% solid content of a solvent-free type (VOC's Free), thereby being eco-friendly and improving work safety.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and it is usually in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications can be implemented by a person having knowledge of these, and these modifications should not be understood individually from the technical idea or prospect of the present invention.

Claims (4)

In the functional coating consisting of the main material and the curing agent,
The subject is bisphenol A type epoxy resin; Bisphenol F type epoxy resin; Alkyl glycidyl ether; Propylene glycol monomethyl ether acetic acid; Mica phase iron oxide; And titanium dioxide,
The subject is 10 to 15 parts by weight of the bisphenol A type epoxy resin; Bisphenol F type epoxy resin is 6 to 7 parts by weight; Alkyl glycidyl ether is 6 to 7 parts by weight; The propylene glycol monomethyl ether acetic acid is 0.25 to 0.28 parts by weight; The mica phase iron oxide is 64 to 66 parts by weight; And the titanium dioxide is 6 to 7 parts by weight; Functional coating agent, characterized in that consisting of. According to claim 1,
The curing agent is benzyl alcohol; Isophorone diamine; Meta-xylene-alpha, alpha-diamine; And salicylic acid. delete According to claim 2,
The curing agent is 35 to 45 parts by weight of the benzyl alcohol; 20 to 30 parts by weight of the isophorone diamine; 20 to 30 parts by weight of the meta-xylene-alpha, alpha-diamine; And 5 to 15 parts by weight of the salicylic acid; Functional coating agent comprising a.

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