KR102776228B1 - Resin composition for coating and coating film - Google Patents

Abstract

One embodiment of the present invention provides a coating film including a coating resin composition and a coating layer formed by the coating resin composition. The coating film according to one embodiment of the present invention has excellent contamination prevention properties and contamination removal properties, and excellent hardness and scratch resistance.

Description

{RESIN COMPOSITION FOR COATING AND COATING FILM}

The present invention relates to a coating film including a coating resin composition and a coating layer formed by the coating resin composition.

Transparent polymer films are key materials in the optical and flexible display fields, and their importance has been increasing recently. Transparent polymer films are used as a material to replace glass in the display field, especially because they are lightweight, easy to process, and flexible. However, since general transparent polymer films have lower surface hardness and wear resistance than glass, research is being conducted to improve the wear resistance of polymer films.

As a method for improving the wear resistance of a polymer film, there is a method of disposing an wear-resistant coating layer on a polymer film. As a technique for forming a coating layer on a polymer film, for example, a high-hardness hard coating film composition including an ultraviolet-curable polyurethane acrylate oligomer is disclosed in Korean Patent Publication No. 2010-0041992, and a vinyl oligo siloxane hybrid composition including a metal catalyst is disclosed in Korean Patent Publication No. 2011-0013891.

Recently, display devices that input information using a touch screen are being applied to electronic devices such as personal digital assistants. In addition, transparent polymer films are placed on the light-emitting surface of these display devices and used as windows.

However, in the case of display devices such as touch screens, where information is directly input onto the surface using a hand or a pen, the surface of the display device may become contaminated by contact with a hand or a pen. Therefore, an optical film that has excellent resistance to fingerprints or stains caused by touch from a hand or pen, or excellent fingerprint or stain removal properties, is required.

One embodiment of the present invention is to provide a coating film having excellent slip properties and excellent resistance to fingerprints or stains caused by touch with a hand or pen.

One embodiment of the present invention is to provide a coating film having excellent wear resistance and excellent scratch resistance.

One embodiment of the present invention is to provide a coating resin composition that can be used for manufacturing a coating film having the above characteristics.

One embodiment of the present invention for solving the above problem provides a coating resin composition including a siloxane resin formed by a reaction solution including a first silane compound represented by the following chemical formula 1, a second silane compound represented by the following chemical formula 2, and a third silane compound represented by the following chemical formula 3.

<Chemical formula 1>

R ¹ _n Si(OR ² ) _4-n

<Chemical formula 2>

C _m F _2m+1 R ³ Si(OR ⁴ ) ₃

<Chemical Formula 3>

Si(OR ⁵ ) ₄

In the above chemical formula 1, R ¹ is a C1 to C4 linear, branched or alicyclic alkyl group in which at least one hydrogen is substituted with an acryl group, R ² is a C1 to C8 linear, branched or alicyclic alkyl group, and n is an integer from 1 to 3.

In the above chemical formula 2, R ³ is a C1 to C4 linear, branched or alicyclic alkylene group, R ⁴ is a C1 to C8 linear, branched or alicyclic alkyl group, and m is an integer from 3 to 10.

In the above chemical formula 3, R ⁵ is a linear or branched alkyl group having C1 to C4.

The above reaction solution may further contain water (H ₂ O).

The content ratio of the first silane compound and the second silane compound, based on the molar ratio, is 1:1 to 10:1 (first silane compound: second silane compound).

The content ratio of the first silane compound and the second silane compound, based on the molar ratio, is 1:1 to 7:1 (first silane compound: second silane compound).

The mixing amount of the first silane compound and the second silane compound and the content ratio of the third silane compound are, on a molar ratio basis, 3:1 to 5:1 (mixing amount of the first silane compound and the second silane compound: content of the third silane compound).

The first silane compound may include at least one selected from 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, 3-acryloxypropyl triethoxysilane, and 3-acryloxypropyl tripropoxysilane.

The second silane compound may include at least one selected from 1H.1H,2H,2H-Perfluoro-octyltriethoxysilane, 1H.1H,2H,2H-Perfluoro-octyltrimethoxysilane, 1H.1H,2H,2H-Perfluoro-octyltrimethoxysilane, 1H.1H,2H,2H-Perfluoro-decyltrimethoxysilane, and 1H.1H,2H,2H-Perfluoro-decyltriethoxysilane.

Another embodiment of the present invention comprises a substrate film and a coating layer on the substrate film, wherein the coating layer can be formed by the coating resin composition.

The surface of the above coating layer has a pencil hardness of 4H or higher as measured by ASTM D3363.

The above coating layer has a water contact angle of 105° to 125°.

The above coating layer has a wear-resistant water contact angle of 100° to 120°.

The above coating layer has a water contact angle of 98° to 118° after 1 hour of wear.

Another embodiment of the present invention provides a coating film comprising a base film and a coating layer on the base film, wherein the coating layer comprises a siloxane resin, has a pencil hardness of 4H or higher as measured by ASTM D3363, and has a water contact angle of 105° to 125°.

The above coating film has a water contact angle after wear of 100° to 120°.

The above coating film has a water contact angle of 98° to 118° after 1 hour of abrasion.

A coating resin composition according to one embodiment of the present invention has a perfluoro group, and thus can provide excellent slip properties and excellent wear resistance. A coating layer according to one embodiment of the present invention manufactured by a coating resin coating layer having a perfluoro group has excellent slip properties and excellent wear resistance.

The coating film according to one embodiment of the present invention including the coating layer as described above can have a large water contact adhesion, an excellent "water contact angle after wear resistance" and an excellent "water contact angle after wear resistance for 1 hour". Accordingly, the coating film according to one embodiment of the present invention can have excellent slip properties, excellent contamination prevention properties and excellent contamination removal properties. In addition, according to one embodiment of the present invention, the contamination prevention sustainability of the coating film is excellent.

In addition, the coating resin composition according to the present invention can be used to produce a coating layer having excellent hardness and scratch resistance, since it contains a multifunctional silane compound.

A coating film according to one embodiment of the present invention including such a coating layer can have excellent surface hardness, wear resistance, and scratch resistance.

Figure 1 is a schematic cross-sectional view of a coating film according to one embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples. The examples described below are presented for illustrative purposes only to help a clear understanding of the present invention, and do not limit the scope of the present invention.

In this specification, when the terms "includes," "has," and "consists of" are used, other parts may be added unless the expression "only" is used. When a component is expressed in the singular, it includes the plural unless there is a special explicit description. In addition, when interpreting a component, it is interpreted to include a range of errors even if there is no separate explicit description.

When describing a positional relationship, for example, when the positional relationship between two parts is described as 'on', 'above', 'below', 'next to', etc., one or more other parts can be located between the two parts, unless the expression 'right' or 'directly' is used.

When describing a temporal relationship, for example, when describing a temporal relationship such as 'after', 'following', 'next to', 'before', etc., it can also include cases where it is not continuous, as long as the expression 'right away' or 'directly' is not used.

Although the terms first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, a first component referred to below may also be a second component within the technical concept of the present invention.

The term "at least one" should be understood to include all combinations that can be presented from one or more of the associated items. For example, the meaning of "at least one of the first, second, and third items" can mean not only each of the first, second, or third items, but also all combinations of items that can be presented from two or more of the first, second, and third items.

The features of each of the various embodiments of the present invention may be partially or wholly combined or combined with one another, and may be technically linked and driven in various ways, and each embodiment may be implemented independently of one another or may be implemented together in a related relationship.

One embodiment of the present invention provides a coating resin composition including a siloxane resin formed by a reaction solution including a first silane compound represented by the following chemical formula 1, a second silane compound represented by the following chemical formula 3, and a third silane compound represented by the following chemical formula 2.

<Chemical formula 1>

R ¹ _n Si(OR ² ) _4-n

In chemical formula 1, R ¹ is a C1 to C4 linear, branched or alicyclic alkyl group in which at least one hydrogen is substituted with an acryl group, R ² is a C1 to C8 linear, branched or alicyclic alkyl group, and n is an integer from 1 to 3.

<Chemical formula 2>

C _m F _2m+1 R ³ Si(OR ⁴ ) ₃

In chemical formula 2, R ³ is a C1 to C4 linear, branched or alicyclic alkylene group, R ⁴ is a C1 to C8 linear, branched or alicyclic alkyl group, and m is an integer from 3 to 10.

<Chemical Formula 3>

Si(OR ⁵ ) ₄

In chemical formula 3, R ⁵ is a linear or branched alkyl group having C1 to C4.

The first silane compound represented by chemical formula 1 may include, for example, at least one selected from 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, 3-acryloxypropyltriethoxysilane, and 3-acryloxypropyl tripropoxysilane.

The first silane compound represented by chemical formula 1 forms a dense network crosslinking upon curing, thereby allowing the coating layer to have excellent surface hardness, wear resistance, and scratch resistance.

In addition, the first silane compound represented by chemical formula 1 contains an acrylic group. The acrylic group improves the adhesiveness of the coating resin composition and can form a crosslinked structure by photocuring. The coating resin composition can be smoothly cured by the first silane compound.

The first silane compound can be used in an amount of 5 mol% to 20 mol% based on the total mole of the reaction solution used in the manufacture of the resin composition for coating.

The first silane compound may include, for example, a compound represented by the following chemical formula 4.

<Chemical Formula 4>

In order to impart slip properties and improve the contamination prevention properties and scratch resistance of the coating layer, the reaction solution used in the manufacture of the coating resin composition according to one embodiment of the present invention includes a second silane compound represented by chemical formula 2.

The second silane compound represented by chemical formula 2 may include at least one selected from 1H.1H,2H,2H-Perfluoro-octyltriethoxysilane, 1H.1H,2H,2H-Perfluoro-octyltrimethoxysilane, 1H.1H,2H,2H-Perfluoro-octyltrimethoxysilane, 1H.1H,2H,2H-Perfluoro-decyltrimethoxysilane, and 1H.1H,2H,2H-Perfluoro-decyltriethoxysilane.

A coating layer formed by a coating composition manufactured by a reaction solution containing a second silane compound represented by Chemical Formula 2 can have a water contact angle of 105° or more, a water contact angle after abrasion of 100° or more, and a contact angle after 1 hour of abrasion of 98° or more. The coating layer having such a water contact angle can have excellent slip properties. As a result, the contamination prevention properties and scratch resistance of the coating layer can be improved. In addition, the abrasion resistance of the coating layer can be improved by fluorine (F) included in the second silane compound.

In addition, since the coating layer manufactured by the coating composition according to one embodiment of the present invention has a post-wear water contact angle of 100° or more, it can have excellent sliding properties even after the surface of the coating layer is exposed to an abrasion environment. Accordingly, even if the coating layer is worn, the contamination prevention properties and scratch resistance of the coating layer can be maintained.

In addition, since the coating layer manufactured by the coating composition according to one embodiment of the present invention has a water contact angle of 98° or more after 1 hour of wear, even if the surface of the coating layer is exposed to an abrasion environment and then left in a high-humidity condition, it can have excellent sliding properties. Accordingly, even if the coating layer is worn and subjected to adverse conditions such as high-humidity conditions, the contamination prevention properties and scratch resistance of the coating layer can be maintained.

The second silane compound can be used in an amount of 1 mol% to 20 mol% based on the total mole of the reaction solution used in the manufacture of the resin composition for coating.

Examples of the second silane compound include a compound represented by the following chemical formula 5 and a compound represented by the following chemical formula 6.

<Chemical Formula 5>

<Chemical Formula 6>

The perfluoro group contained in the second silane compound reduces the surface tension of the coating layer, thereby allowing the coating layer to maintain an excellent contact angle after wear.

The coating resin composition according to one embodiment of the present invention may further include a third silane compound represented by Chemical Formula 3 to form a coating layer having superior hardness. The third silane compound represented by Chemical Formula 3 has four alkoxy groups. A silane compound having four alkoxy groups as represented by Chemical Formula 3 is also called a silane compound having a Q structure.

When the coating resin composition according to one embodiment of the present invention includes a third silane compound, a Q-structured siloxane is formed in the polymer chain of the siloxane resin, so that a coating layer formed by the coating resin composition can have high hardness and scratch resistance like glass.

The third silane compound may include, for example, at least one of tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMOS).

The third silane compound can be used in an amount of 2 mol% to 10 mol% based on the total mole of the reaction solution used in the manufacture of the resin composition for coating.

As an example of a third silane compound, there is a compound represented by the following chemical formula 7.

<Chemical Formula 7>

According to one embodiment of the present invention, the reaction solution used in the preparation of the resin composition for coating may include water (H ₂ O). Water (H ₂ O) may be used as a linker between monomers for forming a siloxane resin and is involved in a dehydration condensation reaction.

According to one embodiment of the present invention, water can be used in an amount of 20 mol% to 50 mol% based on the total mole of the reaction solution used in the preparation of the coating resin composition.

According to one embodiment of the present invention, an organic solvent may be used for solid dilution. As the organic solvent, for example, butanone may be used. The organic solvent may be used in an amount of 30 mol% to 70 mol% based on the total mole of the reaction solution.

According to one embodiment of the present invention, in order to improve the pencil hardness, wear resistance, scratch resistance, and water contact angle of a coating layer formed by a coating resin composition, the contents of the first silane compound, the second silane compound, and the third silane compound are adjusted.

For example, if the content of the first silane compound included in the coating resin composition is insufficient, the coating properties and curing properties of the coating resin composition may deteriorate, and the thermal curing process time may increase significantly. In addition, if the content of the first silane compound is insufficient, the scratch resistance of the coating layer may deteriorate.

When the content of the second silane compound in the coating resin composition is insufficient, the water contact angle of the coating layer formed by the coating resin composition decreases and the sliding properties deteriorate. On the other hand, when the content of the second silane compound is excessively large, the workability may deteriorate and the coatability may deteriorate.

Considering these characteristics, according to one embodiment of the present invention, the content ratio of the first silane compound and the second silane compound can be adjusted in a range of 1:1 to 10:1 (first silane compound: second silane compound) on a molar ratio basis.

More specifically, the content ratio of the first silane compound and the second silane compound can be adjusted in a range of 1:1 to 7:1 (first silane compound: second silane compound) on a molar ratio basis.

In addition, when the third silane compound is excessively included in the coating resin composition, the flexibility of the coating layer formed by the coating resin composition may be reduced. On the other hand, when the content of the third silane compound is insufficient, the silane Q structure is not sufficiently formed in the polymer chain of the siloxane resin, so the pencil hardness and scratch resistance of the coating layer formed by the coating resin composition may be reduced.

Therefore, the mixing amount of the first silane compound and the second silane compound and the content ratio of the third silane compound can be adjusted in the range of 3:1 to 5:1 (mixing amount of the first silane compound and the second silane compound: content of the third silane compound) on a molar ratio basis.

According to one embodiment of the present invention, a siloxane resin is formed by a reaction solution including a first silane compound, a second silane compound, and a third silane compound, thereby producing a resin composition for coating. As previously described, the reaction solution may include water (H ₂ O).

In one embodiment of the present invention, the formation of the siloxane resin can be achieved through an alkoxy diol substitution reaction and condensation polymerization. This reaction can be carried out at room temperature, but in order to promote the reaction, it can be carried out while stirring at 50°C to 120°C for 1 to 120 hours.

According to one embodiment of the present invention, one of the processes for forming a siloxane resin can be expressed by the following reaction formula 1.

<Reaction Formula 1>

In the reaction for forming a siloxane resin, alkoxy undergoes a substitution reaction (or hydrolysis) with water, and also condensation polymerization progresses. As a catalyst, an acid catalyst such as hydrochloric acid, acetic acid, hydrogen fluoride, nitric acid, sulfuric acid, and iodic acid, a base catalyst such as ammonia, potassium hydroxide, sodium hydroxide, barium hydroxide, and imidazole, and an ion exchange resin such as Amberite can be used. These catalysts may be used alone, or two or more types may be used in combination. The catalyst may be added in an amount of 0.0001 to about 10 parts by weight based on 100 parts by weight of the total siloxane compound, but the content of the catalyst is not limited thereto.

When substitution reaction and condensation polymerization proceed, water or alcohol are generated as by-products. By removing these, the reverse reaction can be reduced and the forward reaction can proceed more quickly, thereby controlling the reaction speed. The by-products can be removed by depressurization and heating after the reaction is completed.

According to one embodiment of the present invention, a coating resin composition may further include, in addition to a siloxane resin, at least one additive selected from the group consisting of an organic solvent, a polymerization initiator, an antioxidant, a leveling agent, and a coating agent. By controlling the type and content of the additive, a coating resin composition suitable for various uses can be provided. According to one embodiment of the present invention, a coating resin composition capable of increasing the hardness, wear resistance, flexibility, and curl prevention properties of a film or sheet can be provided.

According to one embodiment of the present invention, as a polymerization initiator, for example, a photopolymerization initiator such as an organometallic salt and a thermal polymerization initiator such as an amine or imidazole can be used. The polymerization initiator can be used in an amount of about 0.5 to 5 parts by weight based on 100 parts by weight of the siloxane resin. If the content of the polymerization initiator is less than 0.5 parts by weight based on 100 parts by weight of the siloxane resin, the curing time of the coating layer to obtain sufficient hardness increases, thereby reducing efficiency, and if it exceeds 5 parts by weight, the yellowness of the coating layer increases, making it difficult to obtain a transparent coating layer.

As an organic solvent, at least one selected from the group consisting of ketones such as acetone, methyl ethyl ketone, methyl butyl ketone, and cyclohexanone; cellosolves such as methyl cellosolve and butyl cellosolve; ethers such as ethyl ether and dioxane; alcohols such as isobutyl alcohol, isopropyl alcohol, butanol, and methanol; halogenated hydrocarbons such as dichloromethane, chloroform, and trichloroethylene; and hydrocarbons such as normal hexane, benzene, and toluene can be used. By controlling the amount of organic solvent added, the viscosity of the siloxane resin can be controlled, and the processability or the thickness of the coating layer can be adjusted.

According to another embodiment of the present invention, a coating resin composition according to an embodiment of the present invention may be formed by coating, casting, molding, or the like, and then photopolymerized or thermally polymerized to form a high-hardness coating layer.

According to the present invention, when the resin composition for coating is polymerized, the light quantity conditions suitable for photopolymerization are 50 mJ/cm2 or more and 20,000 mJ/cm2 or less, and heat treatment can be performed at a temperature of 40°C or more and about 300°C or less to obtain a uniform surface before light irradiation. In addition, the temperature suitable for thermal polymerization is 40°C or more and 300°C or less, but the temperature is not limited thereto.

Figure 1 is a schematic cross-sectional view of a coating film (100) according to one embodiment of the present invention.

Referring to FIG. 1, a coating film (100) according to one embodiment of the present invention includes a base film (110) and a coating layer (120) on the base film (110).

A polyimide (PI) film may be used as the substrate film (110). However, one embodiment of the present invention is not limited thereto, and a polycarbonate film (PC), a polyacrylic film, a polyethylene terephthalate film, a cellulose film, or the like may be used as the substrate film (110).

The coating layer (120) includes a siloxane resin. The siloxane resin may include a perfluoro group.

According to one embodiment of the present invention, the coating layer (120) can be formed by the coating resin composition described above. During the process of forming the coating layer (120), the perfluoro group included in the second silane compound can be mainly located on the upper part of the coating layer. As a result, the perfluoro group can affect the physical properties of the surface of the coating layer (120).

According to one embodiment of the present invention, the coating film (100) may have a pencil hardness of 4H or higher as measured by ASTM D3363. More specifically, the surface of the coating layer (120) formed on the coating film (100) may have a pencil hardness of 4H or higher as measured by ASTM D3363.

According to one embodiment of the present invention, the coating film (100) may have a water contact angle of 105° to 125°, a water contact angle after abrasion of 100° to 120°, and a water contact angle after 1 hour of abrasion of 98° to 118°.

More specifically, the coating layer (120) of the coating film (100) according to one embodiment of the present invention has a water contact angle of 105° to 125°.

Using the DSA100 model of KRUSS, a 5uL water droplet ( _H2O ) is dropped on the coating layer (120), and the angle between the surface of the coating layer (120) and the boundary of the water droplet is measured to obtain the water contact angle. Specifically, the water contact angle is measured by a contact angle measuring device (DSA100 of KRUSS) 1 minute after dropping the water droplet on the surface of the coating layer (120) at room temperature (25°C). The left and right contact angles of the water droplet are measured 5 times using the same sample, and the average value is referred to as the contact angle.

A coating film (100) according to one embodiment of the present invention has a water contact angle after wear of 100° to 120°.

The water contact angle after abrasion is the water contact angle measured after fixing a coating film (100) sample cut into 20 cm X 5 cm pieces to a substrate plane using an adhesive tape (3M) with the coating layer (120) facing upward, and then moving the surface back and forth 3,000 times at a load of 0.5 kgf and a speed of 45 RPM using a rod wrapped with #0000 (LIBERON) nonwoven fabric. At this time, using the DSA100 model of KRUSS, a 5 uL water droplet (H ₂ O) is dropped on the coating layer (120), and the angle between the surface of the coating layer (120) and the boundary of the water droplet is measured, thereby obtaining the water contact angle after abrasion.

A coating film (100) according to one embodiment of the present invention has a water contact angle of 98° to 118° after 1 hour of wear.

The water contact angle 1 hour after abrasion is the water contact angle measured after the water contact angle after abrasion is measured, and then the coating film (100) sample is left in an environment where water droplets are sprayed for 1 hour. At this time, using the DSA100 model of KRUSS, 5uL of water (H ₂ O) is dropped on the coating layer (120), and then the angle between the surface of the coating layer (120) and the boundary of the water is measured, thereby obtaining the water contact angle 1 hour after abrasion.

Hereinafter, the present invention will be described in more detail through specific examples and comparative examples. These examples and comparative examples are only intended to explain the present invention more specifically, and the present invention is not limited thereto.

<Example 1>

1.75 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu), 0.25 mol of 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich), and 0.5 mol of TEOS (Evonik) were placed in a reactor and stirred at 100 rpm for 30 minutes using a mechanical stirrer. After that, 0.003 mol of NaOH was dissolved in 4 mol of water (H ₂ O) and placed into the stirring reactor. The reactor was stirred for 5 hours while maintaining the internal temperature at 60°C. After that, 7 mol (504.77 g) of 2-butanone was added to dilute the mixture, and the resultant was filtered using a 0.45 μm Teflon filter to obtain a siloxane resin.

Next, 3 parts by weight of a photoinitiator, IRGACURE250 (BASF) was added to the siloxane resin diluted in a solvent per 100 parts by weight of the siloxane resin to finally obtain a coating resin composition. This composition was coated on the surface of a polyimide film (KOLON, CPI) using a bar, and after drying at 80°C for 20 minutes, it was exposed to an ultraviolet lamp having a wavelength of 315 nm for 30 seconds to form a 10 μm thick coating layer, thereby producing a coating film.

<Example 2>

A coating resin composition and a coating film were prepared in the same manner as in Example 1, except that 1.5 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu Co.) and 0.5 mol of 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich Co.) were used.

<Example 3>

A coating resin composition and a coating film were prepared in the same manner as in Example 1, except that 1.0 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu Co.) and 1.0 mol of 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich Co.) were used.

<Comparative Example 1>

A coating resin composition and a coating film were prepared in the same manner as in Example 1, except that 2.0 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu Co.) was used and 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich Co.) was not used.

<Comparative Example 2>

A coating resin composition and a coating film were prepared in the same manner as in Example 1, except that 0.75 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu Co.) and 1.25 mol of 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich Co.) were used.

<Comparative Example 3>

A coating resin composition and a coating film were prepared in the same manner as in Example 1, except that 1.88 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu Co., Ltd.) and 0.13 mol of 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich Co., Ltd.) were used.

<Comparative Example 4>

A coating resin composition and a coating film were prepared in the same manner as in Example 1, except that 1.75 mol of 3-methacryloxypropyl trimethoxysilane (KBM-503, Shinetsu Co.), 0.25 mol of 1H,1H,2H,2H-Perfluoro-octyltriethoxysilane (Sigma Aldrich Co.), and no TEOS were used.

<Measurement example>

The coating films manufactured in Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to property evaluation according to the following method, and the results are shown in Table 1 below.

(1) Surface hardness: The pencil hardness was measured using a pencil hardness tester from IMOTO, Japan, at a speed of 180㎜/min and a load of 750gf according to ASTM D3363.

(2) Water contact angle: Using the KRUSS DSA100 model, a 5uL water droplet ( _H2O ) was dropped on the coating layer (120), and the angle between the surface of the coating layer (120) and the boundary of the water droplet was measured. The left and right contact angles of the water droplet were measured five times, and the average value was used.

(3) Scratch resistance: A coating film (100) sample cut to 20 cm X 5 cm was fixed to a flat surface with an adhesive tape (3M) so that the coating layer (120) was facing upward, and then a rod wrapped with #0000 (LIBERON) nonwoven fabric was used to move the surface back and forth 10 times at a load of 1.5 kgf and a speed of 45 RPM to measure whether scratches occurred. If no scratches occurred, it was marked as “Good”, and if scratches occurred, it was marked as “N.G.”

(4) Water contact angle after abrasion: The water contact angle is measured for the coating film (100) sample after the scratch resistance evaluation. Specifically, a sample of the coating film (100) cut to 20 cm X 5 cm on a flat surface is fixed with an adhesive tape (3M) so that the coating layer (120) faces upward, and then the surface is moved back and forth 10 times at a load of 1.5 kgf and a speed of 45 RPM using a rod wrapped with #0000 (LIBERON) nonwoven fabric, and then the water contact angle is measured. At this time, using the DSA100 model of KRUSS, a 5 uL water droplet (H ₂ O) is dropped on the coating layer (120), and the angle between the surface of the coating layer (120) and the boundary of the water droplet is measured, thereby obtaining the water contact angle after abrasion.

(5) Water contact angle 1 hour after abrasion; After measuring the water contact angle after abrasion, the coating film (100) sample is left in an environment where water droplets are sprayed for 1 hour, and then the water contact angle is measured. At this time, using the DSA100 model of KRUSS, 5uL of water (H ₂ O) is dropped on the coating layer (120), and then the angle between the surface of the coating layer (120) and the boundary of the water is measured, thereby obtaining the water contact angle 1 hour after abrasion.

(6) Transmittance and haze: The coating film (100) manufactured according to the examples and comparative examples was cut into 50 mm × 50 mm, and the transmittance and haze were measured five times according to ASTM D1003 using a haze meter (model name: HM-150) from MURAKAMI, and the average value was confirmed.

Pencil hardness My scratch Water contact angle Water contact angle after wear Water contact angle after 1 hour of wear Transmittance Haze Example 1 4H Good 110° 102° 100° 91.5% 1.0% Example 2 4H Good 112° 105° 102° 91.5% 1.0% Example 3 4H Good 112° 105° 103° 91.5% 1.0% Comparative Example 1 4H Good 80° 60° 50° 91.5% 1.0% Comparative Example 2 4H N.G. 112° 105° 103° 91.5% 1.0% Comparative Example 3 4H Good 95° 70° 62° 91.5% 1.0% Comparative Example 4 2H N.G. 110° 100° 96° 91.5% 1.0%

Referring to Table 1, the coating films according to Examples 1 to 3 have excellent pencil hardness and scratch resistance, and excellent water contact angle characteristics.

Referring to Comparative Example 1, when a coating composition is prepared using a coating solution that does not include a second silane compound, it can be confirmed that the water contact angle characteristics of the coating layer and the coating film are deteriorated, and in particular, the water contact angle after abrasion and the water contact angle after 1 hour of abrasion are significantly reduced.

Referring to Comparative Example 2, it can be confirmed that when the content of the first silane compound is reduced and the content of the second silane compound is increased, and the second silane compound is used in greater amount than the first silane compound, the scratch resistance of the coating layer and the coating film is reduced.

Referring to Comparative Example 3, when the amount of the second silane compound used is reduced to less than 10 mol% compared to the amount of the first silane compound used, the water contact angle of the coating layer and the coating film does not reach 100°, and it can be confirmed that the water contact angle after abrasion and the water contact angle after 1 hour of abrasion are significantly reduced.

Referring to Comparative Example 4, it can be confirmed that when the third silane compound is not used, the scratch resistance and pencil hardness of the coating layer and the coating film are reduced.

Referring to the above examples and comparative examples, when the content of the second silane compound including a perfluorinated group is insufficient (Comparative Examples 1 and 3), it was confirmed that the decrease rate of the water contact angle after wear resistance compared to the water contact angle was 20% or more. On the other hand, in the case of examples in which the content of the second silane compound is sufficient, it was confirmed that the decrease rate of the water contact angle after wear resistance compared to the water contact angle was 10% or less, and the decrease rate of the water contact angle after 1 hour of wear resistance was 3% or less.

In this way, it can be confirmed that the coating film according to one embodiment of the present invention has excellent slip properties due to its high water contact angle, excellent contamination prevention properties and contamination removal properties, and excellent hardness, scratch resistance, and wear resistance, so that it can be suitably used as a protective film for a flexible display device.

100: Coating film
110: Film
120: Coating layer

Claims (15)

A first silane compound represented by the following chemical formula 1;
A second silane compound represented by the following chemical formula 2; and
A third silane compound represented by the following chemical formula 3;
Contains a siloxane resin formed by a reaction solution containing
The content ratio of the first silane compound and the second silane compound is, on a molar ratio basis, 1:1 to 10:1 (first silane compound: second silane compound),
The first silane compound comprises at least one selected from 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, 3-acryloxypropyl triethoxysilane and 3-acryloxypropyl tripropoxysilane,
The second silane compound comprises at least one selected from 1H.1H,2H,2H-Perfluoro-octyltriethoxysilane, 1H.1H,2H,2H-Perfluoro-octyltrimethoxysilane, 1H.1H,2H,2H-Perfluoro-octyltrimethoxysilane, 1H.1H,2H,2H-Perfluoro-decyltrimethoxysilane and 1H.1H,2H,2H-Perfluoro-decyltriethoxysilane.
The third silane compound is a coating resin composition comprising at least one of tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMOS):
<Chemical Formula 1>
R ¹ _n Si(OR ² ) _4-n
<Chemical formula 2>
C _m F _2m+1 R ³ Si(OR ⁴ ) ₃
<Chemical Formula 3>
Si(OR ⁵ ) ₄
In the above chemical formula 1, R ¹ is a C1 to C4 linear, branched or alicyclic alkyl group in which at least one hydrogen is substituted with an acryl group, R ² is a C1 to C8 linear, branched or alicyclic alkyl group, n is an integer from 1 to 3,
In the above chemical formula 2, R ³ is a C1 to C4 linear, branched or alicyclic alkylene group, R ⁴ is a C1 to C8 linear, branched or alicyclic alkyl group, and m is an integer from 3 to 10.
In the above chemical formula 3, R ⁵ is a linear or branched alkyl group having C1 to C4. A coating resin composition in claim 1, wherein the reaction solution further contains water (H ₂ O). delete A coating resin composition in claim 1, wherein the content ratio of the first silane compound and the second silane compound is 1:1 to 7:1 (first silane compound: second silane compound) on a molar ratio basis. A coating resin composition in claim 1, wherein the mixing amount of the first silane compound and the second silane compound and the content ratio of the third silane compound are, on a molar ratio basis, 3:1 to 5:1 (mixing amount of the first silane compound and the second silane compound: content of the third silane compound). delete delete Base film; and
A coating layer on the above-mentioned substrate film is included;
A coating film, wherein the coating layer is formed by a coating resin composition according to any one of claims 1, 2, 4 and 5. In claim 8, the surface of the coating layer is a coating film having a pencil hardness of 4H or higher as measured by ASTM D3363. In claim 8, the coating film has a water contact angle of 105° to 125°. In the 8th paragraph, the coating layer is a coating film having a water contact angle after wear of 100° to 120°:
Here, the water contact angle after the abrasion is the water contact angle measured after fixing a coating film sample cut into 20 cm X 5 cm to a flat surface using adhesive tape with the coating layer facing upward, and then moving the surface back and forth 3,000 times at a load of 0.5 kgf and a speed of 45 RPM using a rod wrapped with #0000 (LIBERON) nonwoven fabric. In claim 11, the coating layer is a coating film having a water contact angle of 98° to 118° after 1 hour of wear;
Here, the water contact angle after 1 hour of wear is the water contact angle measured after the coating film sample is left in an environment where water droplets are sprayed for 1 hour after the water contact angle measurement after wear. Base film; and
A coating layer on the above-mentioned substrate film is included;
The above coating layer contains a siloxane resin,
It has a pencil hardness of 4H as measured by ASTM D3363.
Having a water contact angle of 110° to 112°,
Having a water contact angle after wear of 100° to 120°,
Having a water contact angle of 98° to 118° after 1 hour of wear,
The above pencil hardness is measured at a speed of 180 mm/min and a load of 750 gf, coating film. delete delete

Images