KR20150110984A - Surface Treatment Compound and Method for Forming Anti-fouling Coating Film containing the same - Google Patents

Abstract

The present invention relates to a novel surface treatment compound applied to form a contamination prevention coating film and a method for forming the contamination prevention coating film. The surface treatment compound includes perfluoropolyether-modified-polyoxyalkylene silane expressed by the chemical formula 2 or a partially hydrolyzed condensate of perfluoropolyether-modified-polyoxyalkylene silane. Accordingly, a surface treatment agent including the surface treatment compound can be used to form a coating film having excellent contamination prevention performance on a coating target object.

Description

TECHNICAL FIELD [0001] The present invention relates to a surface treatment compound and a method for forming an antifouling coating film containing the same,

The present invention relates to a surface treating compound and a method for forming a coating film comprising the same, and more particularly, to a surface treating compound containing a novel modified perfluoropolyether-modified-polyoxyalkylsilane and a method for forming a coating film containing the same .

Generally, perfluoropolyether containing compounds have physical properties such as water and oil repellency, chemical resistance, lubricity, releasability and antifouling property due to their very low surface energy. Because of these properties, perfluoropolyether-containing compounds are widely used to form protective coatings for water- and oil-repellent agents for paper and fibers, lubricants for magnetic recording media, oil repellents for precision machinery, release agents, cosmetic raw materials, . However, since the general perfluoropolyether-containing compound having such characteristics has weak adhesion to the substrate and weak adhesion, it is difficult to form a rigid coating film firmly bonded to the substrate.

Silane coupling agents, on the other hand, are widely known as means for establishing a firm bond between the surface of a substance such as glass or cloth and an organic compound. The silane coupling agent has an organic functional radical and a reactive silyl radical (typically an alkoxysilyl radical) in the molecule, and the alkoxysilyl radical undergoes a self-condensation reaction with moisture in the air to convert it to siloxane to form a coating . At the same time, the silane coupling agent forms a chemical and physical bond with a glass or metal surface to form a strong coating film having durability.

Thus, in recent years, perfluoropolyester-modified-alkylsilane compounds, which utilize the low surface energy of perfluoropolyethers and exploit the ability of the silane coupling agent to adhere to various substrates, are used as surface treatment agents having a function of preventing contamination .

A perfluoropolyether-modified-alkylsilane compound of the general formula (1), which is applied to a surface treatment agent having the above-mentioned characteristics, is disclosed in Japanese Patent Laid-Open Publication No. JP1998-167597.

[Chemical Formula 1]

R is a divalent linear perfluoropolyether, R is a C1-C4 alkyl group or a phenyl group, X is an organoxy group, n is an integer of 0 to 2, m is an integer of 1 to 5, a is 2 or 3;

However, the perfluoropolyether-modified-alkylsilane compound of formula (1) is excellent in adhesion to the substrate, but lacks durability against environmental conditions such as continuous friction from the outside, continuous contact with salt water, It is difficult to apply.

Therefore, a first object of the present invention to solve the above-mentioned problems is to provide a novel surface treating compound having a perfluoropolyether functional group which can sufficiently guarantee adhesion to a substrate.

A second object of the present invention is to provide a method of forming a coating film for preventing contamination, which comprises the above-mentioned surface treating compound.

According to an aspect of the present invention, there is provided a novel surface treating compound comprising perfluoropolyether-denatured-polyoxyalkylsilane represented by the following general formula (2), perfluoropolyether- Partially hydrolyzed condensates of polyoxyalkyl silanes, or mixtures thereof.

(2)

In the formula (2), k is an integer of 1 to 8, Rf is a perfluoropolyether, m is an integer of 1 to 3, and n is an integer of 1 to 5. a is an integer of 1 to 3, R is an alkyl group having 1 to 4 carbon atoms, and X is an oxyalkyl or acetoxy group having 1 to 3 carbon atoms as a hydrolysis reactor.

Rf is a polymer (perfluoropolyether) containing oxyperfluoroalkyl as a repeating unit having 1 to 5 carbon atoms and 1 oxygen atom, and satisfies a number average molecular weight of 200 to 6000.

In order to form a coating film according to an embodiment of the present invention, a surface treatment agent for forming a coating film including a surface treating compound, an excess solvent, and an additive is first prepared. Subsequently, a coating film for preventing contamination is formed on the surface of the object to be treated, the coating film containing the surface-treating compound as a main component. The surface-treating compound may include a perfluoropolyether-denatured-polyoxyalkylsilane represented by the general formula (2), a partially hydrolyzed condensate of perfluoropolyether-denatured-polyoxyalkylsilane, or a mixture thereof .

As one example, the coating film may be formed on the object to be treated by performing a vacuum deposition or a wet (spray or deposition) coating method.

As described above, the novel surface treating compounds represented by the formula (2) of the present invention are useful for forming anti-fouling coating films having low surface energy and minimized adhesion to contaminants and high durability. Therefore, the anti-fouling coating film containing the novel surface-treating compound as a main component can maintain the long-term effect of preventing the pollution of the pollutants, and even when the pollutants are adhered, the pollutants are easily wiped off, The damage to the surface can be minimized.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned above can be clearly understood by those skilled in the art without departing from the spirit and scope of the present invention.

For the embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and it is to be understood that the embodiments of the invention may be practiced in various forms, The present invention should not be construed as limited to the embodiments described in Figs.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Similar reference numerals have been used for the components in describing each drawing.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the technical idea of the present invention. However, the present invention is not limited to the embodiments described herein but may be embodied in various forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

Surface treatment compound

The surface treatment compound applied in the formation of the antifouling coating film according to the present invention is a perfluoropolyether-denatured-polyoxyalkylsilane represented by the general formula (2). As another example, the surface treatment compound is a partially hydrolyzed condensate of a perfluoropolyether-modified-polyoxyalkylsilane represented by the general formula (2). As another example, the surface treating compound includes both the perfluoropolyether-modified polyoxyalkylsilane represented by the formula (2) and the partial hydrolyzed condensate thereof.

In the formula (2), Rf may be represented by the following formula (4).

(3)

In the perfluoropolyether represented by the formula (3), p or q or r each satisfy 0 to 100. The order and proportions of p, q, and r are not limited to achieving particular objects of the present invention, and are sufficiently meaningful as a copolymer or a homopolymer of each monomer.

Here, the molecular structure of the perfluoropolyether in the formulas is not limited to the exemplified structure.

In addition, the perfluoropolyether-modified-polyoxyalkylsilane represented by the general formula (2) includes a polyoxyalkyl functional group. Examples of the polyoxyalkyl functional group include polymethylene oxide, polyethylene oxide, polypropylene oxide, polybutylene oxide and the like. In Formula (2), X is a hydrolyzable group. Examples of the hydrolyzable group include alkoxy groups such as methoxy, ethoxy, propoxy and butoxy, acyloxy groups such as acetoxy, and alkenyloxy groups such as isopropenoxy. R is a lower alkyl group of 1 to 4 carbon atoms or a phenyl group. Examples of the lower alkyl group include methyl and ethyl.

Although the molecular weight of the compound of the present invention is not critical, it is suitable that it has a number average molecular weight of about 100 to 10,000 and a number average molecular weight of 200 to 6,000 in view of stability and ease of handling.

A feature of the present invention is that the polyoxyalkyl functional group is positioned between the silane functional group and the perfluoropolyether functional group as indicated by the formula (2). The perfluoropolyether functional group has non-adhesive and non-adhesive properties with respect to the polymer chain and the substrate. The polyoxyalkyl functional group serving as a spacer imparts a function of allowing the silane functional group to easily adhere to the substrate and protecting the adhesion surface between the silane and the substrate from the external environment (chemical contact such as mechanical friction, moisture, etc.). Moreover, the polyoxyalkyl functional groups impart compatibility with organic compounds (including solvents) in addition to fluorine-based compounds (including solvents), so that they can be widely used in a manner added to various coating surface treatment agents.

Hereinafter, a method for producing perfluoropolyether-modified-polyoxyalkylsilane will be described.

When perfluoropolyether-modified-polyoxyalkylsilanes are prepared, they are finally prepared by adding silane functional groups to perfluoropolyether-modified-polyoxyalkyls having alcohol functional groups.

Examples of perfluoropolyether-modified-polyoxyalkyls with alcohol functional groups include the fluorolink product of Solvay and the Krytox product of DuPont . The perfluoropolyether-modified-polyoxyalkyl having an allyl functional group can be produced by reacting a metal such as sodium or an alkali metal hydroxide such as potassium hydroxide at the terminal of the perfluoropolyether-modified-polyoxyalkyl having an alcohol functional group Reacted with an allyl halide compound. Also, the perfluoropolyether-modified-polyoxyalkylsilane having a silane functional group at the terminal can be produced by hydrosilylation reaction using a platinum-based catalyst in the allyl functional group.

Surface treatment agent for forming a coating film and method for forming a coating film using the same

The surface treatment agent used for forming the antifouling coating film according to the present invention has a composition including the above-mentioned surface treatment compound, solvent, and additive.

Examples of the surface treatment compound used in the surface treatment agent having the above-mentioned composition include perfluoropolyether-modified-polyoxyalkylsilane represented by Chemical Formula 2, partial hydrolyzed condensate of perfluoropolyether-modified polyoxyalkylsilane Or a mixture thereof. The details of the surface treatment compound are described above in detail and are omitted to avoid duplication.

Also, the solvent comprises at least one solvent. As the solvent, it is preferable to use a solvent in which the perfluoropolyether-modified-oxyalkylsilane represented by the general formula (2) and the partially hydrolyzed condensate thereof are uniformly dissolved.

Examples of the solvent include fluorine-modified aliphatic hydrocarbon solvents (perfluoroheptane and perfluorooctane), fluorine-modified aromatic hydrocarbon solvents (m-xylene hexafluoride and benzotrifluoride), fluorine-modified ether solvents Fluoro-modified alkylamine solvents (perfluorotributylamine and perfluorotripentylamine), hydrocarbon solvents (petroleum benzine, mineral spirits, toluene and xylenes), perfluoro ), And ketone solvents (acetone, methyl ethyl ketone and methyl isobutyl ketone). Among them, it is preferable to use fluorine-modified wax in view of solubility and wettability.

By coating a surface treatment agent containing the above-mentioned surface treatment compound, perfluoropolyether-modified-polyoxyalkylsilane, on the object to be treated (paper, cloth, metal, metal oxide, glass, plastic, magnetic and ceramic, It is possible to form an antifouling coating film having excellent durability. For example, the surface treatment agent is useful as a surface treatment agent for forming an antifouling coating film that requires stain resistance and durability at the surface of the antireflection layer.

Hereinafter, a method of forming a coating film using the surface treatment agent will be described.

First, a surface treatment agent for forming a coating film containing a surface treatment compound and a solvent is prepared. The surface treatment compound contained in the surface treatment agent may be a perfluoropolyether-modified-polyalkyl ether silane represented by the following formula (2), a partially hydrolyzed condensate of a perfluoropolyether-modified polyalkyl ether silane, or a mixture thereof .

The content of the surface treating compound contained in the surface treating agent varies depending on the method of forming the coating film. For example, when a coating film is formed by applying a vacuum evaporation technique, the surface treating agent has a composition including 10 to 70% by weight of a surface treating compound and an extra solvent and an additive. When the coating agent is formed by applying a wet coating method, 0.01 to 5% by weight of a surface treatment compound, and an extra solvent and an additive.

Subsequently, a coating film containing a surface treating compound as a main component is formed on the surface of the object to be treated by using a surface treating agent.

As one example, the coating film may be formed by a vacuum evaporation technique including vacuum evaporation by electron beam heating and evaporation of molybdenum by electron beam evaporation, including evaporation of the surface treatment compound contained in the surface treatment agent and vacuum evaporation of the surface treatment compound onto the surface of the object to be treated Vacuum deposition by heating the boat). Particularly, the vacuum deposition technique is carried out by using a tablet formed by impregnating a molding having a cavity (ceramic tablet, steel wool tablet, etc.) with a surface treatment agent and then evaporating the solvent contained in the surface treatment agent. The object to be treated having a coating film formed by such a deposition technique is excellent in the function of preventing contamination, and no additional coating process is required.

As another example, the coating film may be formed by performing a wet coating method (spraying, immersion, gravure, etc.) including a step of coating the surface treatment agent on the surface of the object to be treated and a step of drying the surface treatment agent.

Examples of the products to which the coating film formed using the surface treatment agent on the surface of the object to be treated are applied include an optical member such as an eyeglass lens and an antireflection filter (a coating for preventing fingerprint and lipid contamination) and a vehicle such as an automobile, a train and an aircraft (Water repellent and antifouling coatings), kitchen linens (coatings to prevent oil contamination), artwork (water-repellent and oil-repellent, anti-fingerprint coatings), and compact discs and DVDs A coating for preventing fingerprints).

In particular, the surface treatment agent is particularly suitable for forming a coating film on an optical member such as a lens and a filter (antireflection filter) to give a coating film having antireflection property and antifouling property thereto. The antireflection filter includes an inorganic antireflection layer including a surface layer in the form of a silicon dioxide-based inorganic layer and a antifouling coating film formed on the surface layer.

Hereinafter, the present invention will be described in detail through synthesis examples for producing perfluoropolyether-modified-polyoxyalkylsilanes and examples for preparing surface treating agents. The present invention is not limited to the synthesis examples and the embodiments.

Synthesis Example 1

160 g of polyfluoropolyether-modified polyoxyethylenes having an allyl ether functional group at the end represented by the following formula (4), 80 g of m-xylene hexafluoride, 0.1 g of a chloroplatinic acid catalyst, 15 g of trimethoxysilane, The mixture was homogeneously mixed and stirred at a temperature of about 70 DEG C for about 8 hours. Thereafter, the solvent was removed by distillation to obtain 170 g of a perfluoropolyether-modified-polyoxyalkylsilane represented by the following formula (5) as a colorless transparent liquid.

[Chemical Formula 4]

[Chemical Formula 5]

In the formulas (4) and (5), Rf1 is a polymer (perfluoropolyether) containing oxyperfluoroalkyl having 1 to 5 carbon atoms and 1 oxygen atom as repeating units and having a number average molecular weight of 200 to 6,000 will be

Comparative Synthesis Example 1

160 g of a polyfluoropolyether having an allyl ether functional group at the end represented by the following formula (6), 80 g of m-xylene hexafluoride, 0.1 g of a chloroplatinic acid catalyst and 15 g of trimethoxysilane were uniformly mixed, The mixture was stirred at a temperature of 70 DEG C for about 8 hours. Thereafter, the solvent was removed by distillation to obtain 165 g of a perfluoropolyether-modified-alkylsilane represented by the following formula (7) which is a colorless transparent liquid.

[Chemical Formula 6]

(7)

Rf1 in formulas (6) and (7) is a polymer (perfluoropolyether) comprising oxyperfluoroalkyl having 1 to 5 carbon atoms and 1 oxygen atom as repeating units and having a number average molecular weight of 200 to 6,000 will be

Example 1

The surface treatment agent was prepared by dissolving the perfluoropolyether-modified-polyoxyalkylsilane obtained in Synthesis Example 1 in perfluoro (2-butyltetrahydrofuran) in an amount of 20% by weight. Thereafter, 0.5 g of the surface treatment agent was applied to a tablet (weight 2.0 g) produced using steel wool, and the solvent was volatilized to prepare a vacuum evaporation tablet containing perfluoropolyether-modified-polyoxyalkylsilane Respectively. Subsequently, a first anticorrosion film was formed on a base material (substrate in which silicon dioxide and titanium dioxide were alternately vacuum-deposited on an acrylic plate) on which an antireflection layer was formed in a vacuum evaporator to which a tablet was applied. At this time, the inside of the vacuum evaporator is maintained at a pressure of about 5 * 10 -5 torr, and the tablet is heated to about 400 캜 on a molybdenum boat to evaporate the compound of the formula (5).

Comparative Example 1

A second pollution preventive film was obtained in the same manner as in Example 1, except that the perfluoropolyether-modified (meth) acrylate obtained in Comparative Synthesis Example 1 was used instead of the perfluoropolyether-modified-polyoxyalkylsilane obtained in Synthesis Example 1 -Alkylsilane. ≪ / RTI >

Example 2

The perfluoropolyether-modified-polyoxyalkylsilane of Chemical Formula 5 obtained in Synthesis Example 1 was diluted with methyl perfluorobutyl ether to a weight ratio of 0.001 to prepare a surface treatment agent (antifouling coating solution). Subsequently, the surface treatment agent was impregnated with a base material (substrate on which an acrylic plate and silicon dioxide and titanium dioxide were alternately vacuum-deposited on each other) with an antireflection layer formed thereon by using an inorganic substance, and after one minute, the substrate was taken out and heated at 70 ° C for 10 minutes, Barrier film.

Comparative Example 2

A perfluoropolyether-modified-alkylsilane of Chemical Formula 6 obtained in Comparative Synthesis Example 2 was used in place of the compound of Synthesis Example 1, except that a fourth pollution prevention film was formed in the same manner as in Example 2.

The physical properties of the antifouling films obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated by the following methods. The physical property tests of the antifouling membranes were carried out five times and the optimum values were recorded. The obtained results are summarized in Table 1 below. The test methods are summarized below.

end. Contact Angle: Measure the angle between the surface and the water droplet when the distilled water is placed in the size of 3 microliters using a contact angle meter (SEO) on the surface of the sample where the anti-contamination membrane is formed.

I. Oil-repellency (Adhesiveness of oil-repellent pens): A line of 3 centimeters is drawn on the surface of the sample on which a contamination prevention film is formed using a Monami oil-repellent pen, and its ease of sticking or surface wettability is visually determined. The criteria are as follows.

○: The handwriting is made up of points of thought and it is one line shortened.

△: The handwriting is the points of the idea but it is several lines, and it looks as a broad line.

X: Something with a wide handwriting.

All. Easy cleaning: Wipe the line by the oil pan with a small force using microfibers, and visually judge easiness of the drop. The criteria are as follows.

○: The handwriting can be completely wiped.

△: The handwriting remains blurred.

X: I can not make a handwriting.

la. Abrasion resistance: Rub the surface of the sample with a rubber eraser to 500 g load at 50 rpm for 3,000 times at 50 rpm and observe the degree of change of the contact angle.

hemp. Slip resistance: Judge according to the degree of slip felt after rubbing a circle using microfiber. The criteria are as follows.

○: Slippery thing.

Δ: A little slippery or stiffness remains.

X: Stiff.

bar. Salt water: 5% by weight NaCl aqueous solution was continuously sprayed at 35 ° C at a pressure of 0.6 MPa for 72 hours, and then the degree of contact angle change was observed.

Example 1 Comparative Example 1 Example 2 Comparative Example 2 Coating method Vacuum deposition Vacuum deposition Wet coating Wet coating Surface treatment compound Formula 4 6 Formula 4 6 Contact angle 112 105 113 109 Foot oil ○ △ ○ ○ Easy cleaning ○ ○ ○ ○ Abrasion resistance 1500 times 102 82 107 102 Abrasion resistance 3000 times 98 74 105 97 Slipperiness ○ X ○ △ Salt water 111 104 112 109

As can be seen from the results shown in Table 1, when the coating film is formed using the compound of Formula 4, the contact angle, the wear resistance and the salt resistance show a higher contact angle than the case of using the compound of Formula 6. In addition, there is no significant difference in easy cleaning characteristics, but it exhibits relatively good physical properties in oil repellency and slip resistance.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

As described above, the novel surface treating compounds represented by the formula (3) of the present invention are useful for forming anti-fouling coating films having low surface energy and minimized adhesion to contaminants and at the same time having excellent durability. Therefore, the anti-fouling coating film containing a novel surface-treating compound as a main component can keep the pollution-preventing effect against pollutants for a long period of time. Even if pollutants are requested, pollutants are easily wiped off, The damage to the surface can be minimized.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It will be understood that the invention may be modified and varied without departing from the scope of the invention.

Claims (6)

A perfluoropolyether-denatured-polyoxyalkylsilane represented by the following general formula (2), a partial hydrolysis-condensation product of the perfluoropolyether-denatured-polyoxyalkylsilane or a mixture thereof Surface treatment compounds.
(2)

(Wherein k is an integer of 1 to 8, Rf1 is a perfluoropolyether, m is an integer of 1 to 3, and n is an integer of 1 to 5. The letter a is an integer of 1 to 3 R is an alkyl group having 1 to 4 carbon atoms, and X is a hydrolysis reactor and is an oxyalkyl or acetoxy group having 1 to 3 carbon atoms. The polymer of claim 1, wherein Rf1 is a polymer (perfluoropolyether) comprising oxyperfluoroalkyl having 1 to 5 carbon atoms and 1 oxygen atom as repeating units and having a number average molecular weight of 200 to 6000 By weight based on the total weight of the composition. Providing a surface treatment agent for forming a coating film comprising a surface treating compound, a solvent and a functional additive; And
Forming a coating film containing a surface treating compound as a main component on a surface of a subject to be treated, wherein the surface treating compound is a perfluoropolyether-denatured-polyoxyalkylsilane expressed by the following general formula (2) A partially hydrolyzed condensate of a polyoxyalkylene silane, a partially hydrolyzed condensate of a polyoxyalkylene silane, a partially hydrolyzed condensate of a polyoxyalkylene silane,
(2)

(Wherein k is an integer of 1 to 8, Rf1 is a perfluoropolyether, m is an integer of 1 to 3, and n is an integer of 1 to 5. The letter a is an integer of 1 to 3 R is an alkyl group having 1 to 4 carbon atoms, and X is a hydrolysis reactor and is an oxyalkyl or acetoxy group having 1 to 3 carbon atoms. The method according to claim 3, wherein the coating film comprises: heating the tablet impregnated with the surface treating agent to evaporate the surface treating compound; And
And vapor-depositing the evaporated surface-treating compound on the surface of the object to be processed. [4] The method of claim 3, wherein the coating layer comprises: wet coating the surface treatment agent on the surface of the object to be treated; And
And drying the surface treatment agent to form a coating layer. The method according to claim 3, wherein the object to be treated is a display product, and the coating film is a contamination preventing film.