KR101439581B1 - Surface layer and method for preparing the same - Google Patents

Abstract

The present invention relates to a surface layer excellent in abrasion resistance and stain resistance, a method for producing the same, and a composition for forming a surface layer used in the surface layer production method. The present invention provides a surface layer having excellent mechanical properties and stain resistance by using a functional acrylate monomer to improve abrasion resistance and hardness, and the upper layer of the surface layer has a low surface energy and vaporizes a monomer capable of controlling surface physical properties do.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface layer and a method of manufacturing the same,

The present invention relates to a surface layer excellent in abrasion resistance and stain resistance, a method for producing the same, and a composition for forming a surface layer used in the surface layer production method.

Fingerprint contamination is the most common contamination in various displays and high-gloss products, resulting in poor visibility of product appearance. Particularly in the case of a display, there is a problem that the image can be easily distorted by the fingerprint, and the appearance quality is greatly deteriorated.

Conventionally, the following surface treatment or surface layer forming method has been used to prevent such fingerprint contamination.

The first method is a method of introducing a hydrophobic fluorine-based or silicone-based surfactant into the abrasion-resistant coating liquid and forming a surface layer using the same. This method is that after the curing of the coating liquid, the hydrophobic surfactant is placed on the surface of the product to give the film contamination. However, since the hydrophobic surfactant is not bonded to the binder of the coating layer, this method has a disadvantage in that its characteristics are rapidly deteriorated when the contamination characteristics are measured after rubbing the surface several hundred times with a cloth. Also, in order to ensure a satisfactory level of contamination resistance, an excess amount of a surfactant should be added. In this case, the abrasion resistance is deteriorated.

The second method is to form an abrasion-resistant coating layer on the product surface first with an abrasion-resistant coating liquid, and separately form an anti-contamination coating layer on the abrasion-resistant coating layer. That is, it is a method of performing coating twice or more in order to form a surface layer of abrasion resistance and stain resistance. However, this method has a limitation that a wear-resistant coating layer must have a bonding functional group capable of reacting with the contaminant layer forming material, and the manufacturing cost is increased due to the addition of the manufacturing process according to the two- have. Further, when the oil is continuously contaminated by an oil component such as a fingerprint, the oil penetrates into the wear-resistant coating layer and / or the contamination-resistant coating layer, and thus the film characteristics of abrasion resistance and / or stain resistance are rapidly deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the need to overcome the symmetric point constraints for the simultaneous expression of the abrasion resistance characteristics and the stain resistant surface characteristics of the prior art described above, to solve the problem of bonding strength between the contaminated stratified part and the abrasion resistant part, and to simplify the process.

The present inventors have found that when a specific method is used as a method of forming a surface layer, the composition can be made different from that of a conventional coating method, and mechanical properties such as excellent abrasion resistance can be improved and surface properties such as water- A surface layer can be provided by using a composition that can be used.

Accordingly, an object of the present invention is to provide a surface layer capable of providing excellent surface characteristics, a method for producing the same, and a composition for forming a surface layer used for forming the surface layer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the conventional art,

At least one monomer, a polymerization initiator, and at least one functional acrylate, wherein the functional acrylate has three or more crosslinking functional groups.

Also, the method includes the steps of: heat-treating the composition for forming a surface layer of the present invention at a temperature at which the monomer is pyrolyzed in a polymerizable form; and performing deposition and polymerization while maintaining the temperature at a temperature lower than the temperature in the heat- Wherein the fluorocarbon content in the surface layer forming composition is changed at least once or the above steps are repeated using two or more compositions having different fluorocarbon contents in sequence.

Also, as a surface layer formed by polymerization of a composition comprising at least one monomer, a polymerization initiator, and at least one functional acrylate having three or more crosslinking functional groups,

Wherein the monomer comprises a fluorocarbon,

Wherein the content of the fluorocarbon has a concentration gradient in the thickness direction of the surface layer.

Also provided is a product comprising the surface layer according to the present invention.

The surface layer according to the present invention has an excellent effect of abrasion resistance and contamination resistance.

Hereinafter, the present invention will be described in detail.

The composition for forming a surface layer according to the present invention comprises at least one monomer, a polymerization initiator and at least one functional acrylate, wherein the functional acrylate has three or more crosslinking functional groups.

The monomer of the present invention may be a fluorocarbon or a monomer of the following formula (1), which may be selected depending on the characteristics of the desired surface layer.

[Chemical Formula 1]

R ¹ is hydrogen or a straight or branched alkyl group having 1 to 20 carbon atoms,

이며, X is

Lt;

이고,Y is

ego,

이고, 여기서 R²는 수소, 탄소수 1 내지 20의 직쇄 또는 분지쇄의 알킬기, 탄소수 3 내지 40의 시클로알킬기, 탄소수 6 내지 40의 아릴기 또는 탄소수 7 내지 40의 아랄킬기이다.Z is

Wherein R ² is hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, or an aralkyl group having 7 to 40 carbon atoms.

The fluorocarbon includes a halogen compound in which at least one hydrogen of the hydrocarbon is substituted with fluorine (F), and may further include a heteroatom such as oxygen. The fluorocarbon includes hexafluoropropylene oxide (HFPO) and the like.

As the polymerization initiator, a radical initiator can be used. Specifically, a peroxide compound, a hydroperoxide compound, a diazine compound, or the like can be used, but the present invention is not limited thereto.

The composition of the present invention comprises a functional acrylate monomer. As such a functional acrylate monomer, a mixture of one or more of a polyfunctional acrylate monomer, a bifunctional acrylate monomer, or a monofunctional acrylate monomer may be used.

When all of the polyfunctional acrylate monomer, the bifunctional acrylate monomer, and the monofunctional acrylate is used, the mixing ratio is preferably in the range of 10 to 90% by weight based on the weight of the multifunctional monomer, the bifunctional monomer 10 to 70, the monofunctional monomer 10 to 90 Or less. When the mixing ratio satisfies the above range, it is possible to maintain an appropriate viscosity and to handle and to exhibit excellent deposition operation efficiency. It also has excellent scratch resistance and hardness characteristics when forming a coating film.

The polyfunctional acrylate monomer preferably refers to a monomer having three or more acryloxy groups or methacryloxy groups in one molecule. The multifunctional acrylate monomer may be any multifunctional acrylate monomer as long as it contains three or more acryloxy groups or methacryloxy groups per molecule. As typical examples thereof, Hexafunctional monomers such as dipentaerythritol hexaacrylate and dipentaerythritol hexaacrylate; quadrupole functional monomers such as pentaerythritol tetraacrylate (PETA); trimethylolpropane triacrylate (TMPTA); Trifunctional monomers.

Another embodiment of the present invention provides a surface layer formed using the composition for forming a surface layer.

The surface layer according to the present invention may be provided with a base layer on one surface. In this case, the fluorocarbon content in the range of 10% or less in thickness from the surface in contact with the surface layer and the base layer, Is less than the fluorocarbon content in the range exceeding 10%. This makes it possible to further improve the adhesion between the base layer and the surface layer even when the same amount of material is used, and to improve the surface properties such as smoothness, stain resistance and abrasion resistance in the surface layer on the opposite side not in contact with the base layer do.

The physical properties of the surface layer of the present invention have a root mean square surface roughness value of 1 nm or more, preferably 10 to 100 nm. The surface energy of the surface layer has a value of 30 mN / m or less, the contact angle with water is 85 degrees or more, preferably 95 degrees or more, and the contact angle with diiodomethane is 65 degrees or more, preferably 75 Or more.

Another embodiment of the present invention provides a method for producing a surface layer using the above composition for forming a surface layer.

The inventors of the present invention have found that when a conventional solvent coating method is used, there is a limitation in usable materials to be used because of solubility in a solvent, and a crosslinking agent having three or more crosslinking functional groups in the coating and curing process is damaged There is a problem that gelation occurs when used. Therefore, when the conventional solvent coating method is used, there are limitations in improving surface characteristics such as abrasion resistance, stain resistance and transparency. However, in the present invention, by using a crosslinking agent having three or more crosslinking functional groups, it is possible to provide a surface layer having a high degree of crosslinking and excellent in surface characteristics such as abrasion resistance, stain resistance and transparency, Unlike the coating method, a variety of materials can be used without using a solvent, and even when a crosslinking agent having three or more crosslinking functional groups is used, problems such as gelation can be avoided.

The surface layer production method of the present invention is a kind of CVD (Chemical Vapor Deposition), in which a precursor for forming a main chain of a surface layer film is supplied to a vacuum chamber, and the supplied precursor is supplied with thermal energy and polymerized The polymer is polymerized. In this process, the polymerization initiator may be supplied for polymerization of the polymer, and the polyfunctional acrylate may be supplied to improve the mechanical properties. In the deposition process, various methods such as a hot wire or a heating block may be used to supply the heat energy.

Particularly, in order to compensate for the low mechanical properties of the surface layer produced by the vacuum deposition method, the production method of the present invention can improve the abrasion resistance and hardness by using a functional acrylate monomer and improve the abrasion resistance and hardness of the upper layer of the surface layer ) Is characterized by producing a surface layer having excellent mechanical properties and stain resistance through a deposition process using monomers capable of controlling surface physical properties having low surface energy.

In a specific embodiment, the surface layer forming composition containing the fluorocarbon of the present invention is heat-treated at a temperature at which the at least one monomer is thermally decomposed in a polymerizable form, and the temperature is maintained at a temperature lower than the temperature in the heat- And a step of repeating the above steps by sequentially using two or more compositions having different fluorocarbon contents by changing the fluorocarbon content in the composition for forming a surface layer at least once or more .

Another embodiment of the present invention provides a product comprising the surface layer. The surface layer may be formed directly on the target product to be applied, but may be applied to the target product after forming it on the base material first.

As the above substrate, a polymer film or glass can be used. As the polymer film, a polymer film containing at least one selected from polyester, triacetyl cellulose, olefin copolymer and polymethyl methacrylate can be used.

The above products are not limited to large-sized electronic products such as portable electronic devices and large-area displays such as mobile phones and laptops, but also high-gloss products such as interior and exterior materials for buildings and automobiles, . The display may include a liquid crystal display (LCD), an organic light emitting display (OLED), and a plasma display panel (PDP).

Hereinafter, the present invention will be described in more detail by way of examples. It is to be understood that the embodiments disclosed herein are for the purpose of illustration only and are not intended to limit the scope of the present invention.

Example 1

A PET film was placed as a substrate in a vacuum chamber, the vacuum degree was maintained at 10 ^-3 Torr, and PETA (pentaerythritol tetraacrylate) was polymerized as a polymeric polymer with a bubbler to produce a partial pressure ) Was injected into the vacuum chamber while controlling to a level of 200 mTorr. At the same time, TBPO (tert-butyl peroxide), an initiator, was flow-regulated by MFC and a partial pressure of 100 mTorr was injected.

The injected PETA and TBPO were deposited on a substrate through a heat source device set at 250 ° C in a vacuum chamber. The deposition time was maintained for 20 minutes to form a 1 μm film, and then the precursor was converted into HFPO (Hexafluoropropylene oxide) to perform deposition. The partial pressure of injected HFPO was controlled to 300 mTorr. At this time, the temperature of the heat source device was changed to 450 ° C to perform deposition. The deposition film using HFPO was allowed to proceed for 5 minutes to obtain a thickness of 10 nm. Through this process, a hard layer using PETA was formed on the lower layer, and an impregnated layer with low surface energy was obtained using HFPO as the upper layer. The surface roughness (Rrms) of the surface layer obtained by this process was 13 nm and the surface energy was 20 mN / m or less.

Example 2

In order to improve the surface roughness level, the PET film was plasma treated before the surface layer deposition. Argon (Ar) was used as a plasma gas and RF (Radio Frequency) power was used as a plasma power source. During the plasma treatment, the working vacuum level was 300 mTorr and treated at 100 W for 10 minutes. The surface roughness (Rrms) before the treatment was 8 nm, and the surface roughness (Rrms) of the PET film after plasma treatment was greatly increased to 123 nm. After the plasma treatment, the surface layer was deposited in the same manner as in Example 1, the lower layer was deposited using PETA to a thickness of 1 μm, and the upper layer was deposited to a thickness of 100 nm using HFPO. The surface roughness (Rrms) of the deposited film on the plasma treated surface was 110 nm and the surface energy was less than 10 mN / m.

Also, the film obtained in Example 2 confirmed that the amount of transferred fingerprints on the surface of the general PET was less than 50% when transferring the fingerprint. At this time, evaluation of the transfer amount of the fingerprint was performed by transferring the fingerprint to the PET having the non-deposited PET film and the deposited surface layer under the same pressure, and then evaluating the area occupied by the transferred fingerprint through the optical microscope. For reproducibility, the data were obtained 10 times or more under the same conditions and the average value was obtained.

Claims (13)

delete delete delete A composition for forming a surface layer comprising at least one kind of monomer including fluorocarbon, a polymerization initiator, and at least one functional acrylate having three or more crosslinking functional groups is heated at a temperature at which the monomer is pyrolyzed in a polymerizable form And performing the deposition and polymerization while maintaining the temperature at a temperature lower than the temperature in the heat treatment step, wherein the content of the fluorocarbon in the composition for forming a surface layer is changed at least once, or the content of the fluorocarbon The above steps are repeated using two or more compositions having different contents in sequence,
The content of the fluorocarbon has a concentration gradient in the thickness direction of the surface layer,
Layer structure composed of two or more layers having different contents of fluorocarbons,
Wherein the content of fluorocarbon in the thickness within 10% from the one side of the surface layer is different from the content of fluorocarbon in the range exceeding 10% in thickness from the side of the surface layer.
delete A surface layer produced according to claim 4.
delete delete A surface layer formed by polymerization of a composition comprising at least one monomer, a polymerization initiator, and at least one functional acrylate having three or more crosslinking functional groups,
Wherein the monomer comprises a fluorocarbon,
The content of the fluorocarbon has a concentration gradient in the thickness direction of the surface layer,
Layer structure composed of two or more layers having different contents of fluorocarbons,
Wherein the content of fluorocarbon in the thickness within 10% from the one side of the surface layer is different from the content of fluorocarbon in the range exceeding 10% in thickness from the side of the surface layer.
The fluorocarbon content in the range of 10% or less in thickness from the surface in contact with the surface layer and the base layer is 10% or more by more than 10% from the surface in contact with the surface layer and the base layer Lt; RTI ID = 0.0 > fluorocarbon < / RTI > content.
delete An article comprising a surface layer according to claim 9 or 10.
13. The product of claim 12, wherein the product is selected from a cell phone, a notebook, a display, and a high-gloss product.