KR100381552B1 - Coating method of supe hydrophilic thin-coating - Google Patents

Abstract

The present invention relates to a super-hydrophilic thin film forming method for forming a super-hydrophilic thin film having excellent durability and reproducibility to prevent fogging while maintaining an anti-reflective coating function in a plastic spectacle lens.

The present invention is capable of reacting with Si-OH formed by silica (SiO 2) coated on the surface of a plastic spectacle lens, and the other side is coated with a compound having a surface functional group capable of various chemical reactions, and then the surface functional group described above. It has a functional group capable of reacting at one end and the other is coated with a compound having a hydrophilic functional group to form a superhydrophilic thin film.

Description

Coating method of supe hydrophilic thin-coating

The present invention relates to a super-hydrophilic thin film forming method for forming a super-hydrophilic thin film having excellent durability and reproducibility to prevent fogging while maintaining an anti-reflective coating function in a plastic spectacle lens.

Various plastic materials, glass, transparent ceramics and mirror materials have been used extensively because of their excellent transparency and mirror properties, but one of the serious drawbacks of these materials is that they are higher in temperatures and temperatures than in the outside atmosphere, where high temperatures and high humidity are maintained. When used indoors, the vapor condenses in the form of fine droplets on the surface of these materials, causing the surfaces of these materials to frost, resulting in a sharp drop in transparency.

Recently, anti-fog mirrors manufactured using hydrophilic surface technology are coated with a hydrophilic material mixed with a polymeric polymerizable binder to form a micron thick film by UV and thermosetting. In order to prevent fogging, the function of the anti-reflective coating already applied to the spectacle lens is invalidated.

In general, materials form waterdrops due to the interfacial tension with water on the surface when they are in contact with water, and the hydrophilicity of water can be expressed as the water contact angle with the material.The water contact angle with inorganic materials such as glass Is 20 ~ 30 °, general resin (ex: silicone resin) is 70 ~ 90 °, hydrophobic resin (ex: fluorocarbon polymer) is more than 90 °, and the bigger the water contact angle, the lower the transparency. By coating a polar material that can maximize the spreading of the water droplets flat to prevent the fog caused by fine water droplets.

The surface of the plastic spectacle lens is coated with silica (SiO 2) to present the silanol (Silanol, -SiOH), and -SiOH itself on the surface of the spectacle lens exhibits hydrophilicity. If it is easily contaminated, the hydrophilicity is rapidly lost, and the hydrophilicity cannot be recovered unless a complicated chemical cleaning process is performed.

In addition, currently used anti-fog anti-fog is basically a liquid anionic surfactant is applied to the lens surface to show a water contact angle of less than 10 ° but surfactants that cannot form a permanent chemical bond with the lens surface is a lens surface Because it forms a layer of physical adsorption, it is easily detached by weak stimulation by nonwoven fabric or other materials in dry state, so only one-time effect is expected, and durability and durability of effect are very low. In order to maintain the anti-fog function, it is necessary to repeat the anti-fog coating process every 3-4 hours, which is very inconvenient in practical use.

The present invention is to chemically bond a compound having a hydrophilic functional group (Hydrophilic) to the lens surface to permanently hydrophilic surface to always lower the water contact angle to less than 10 ° to prevent fog.

The present invention is capable of reacting with Si-OH formed by silica (SiO 2) coated on the surface of a plastic spectacle lens, and the other side is coated with a compound having a surface functional group capable of various chemical reactions, and then the surface functional group described above. It has a functional group capable of reacting at one end and the other is coated with a compound having a hydrophilic functional group to form a superhydrophilic thin film.

The present invention is to chemically coat a super-hydrophilic thin film having a permanent anti-fog function without hindering the hard coating and anti-reflection function coated on the surface of the plastic spectacle lens, chemically bonded to the lens surface The coating film thickness of the hydrophilic group is 500Å or less, the water contact angle is 15 ° or less, and the adhesive strength is 0.5 Kgf / 15mm.

In order to achieve the above-described physical properties, the present invention increases the Si-OH density formed by the coating of SiO 2 on the surface of a plastic spectacle lens, and then reacts with -SiOH on one side of the lens and various chemical reactions on the other. It is coated with a compound having a surface functional group as possible, and has a functional group capable of reacting with the surface functional group described above, and the other is coated with a compound having a hydrophilic functional group to form a superhydrophilic thin film.

Hereinafter, the steps of chemically forming a superhydrophilic thin film on the plastic spectacle lens will be described.

A. Surface Si-OH Formation Step

Silica (SiO ₂ ), which is a surface coating material for hard and anti-reflective function, is coated on the surface of the plastic spectacle lens by using a plasma technique, and thus Si-OH is formed on the surface. Going through.

However, if the Si-OH group is not sufficiently formed on the surface of the plastic lens, the partially hydrated tetraethoxy orthosilicate (Si (OCH ₂ CH ₃ ) ₄ ) can be coated to increase the density of Si-OH. If the surface is contaminated with various impurities (contamination from hands or various organic impurities), the surface should be carefully cleaned as follows.

B. Surface Cleaning Process

The lens was placed in a solution of sulfuric acid (H ₂ SO ₄ (30%)) and hydrogen peroxide (H ₂ O ₂ ) at a volume ratio of 7: 3 (35 / 15-20 ml), and washed with an ultrasonic cleaner for 1 hour. After removing the surface organic impurities, washed with deionized pure water (deionized H ₂ O, hereinafter DI water).

To clean metal impurities on the surface of the lens, ammonia (NH ₃ ) forms a water-soluble complex with a metal so that it can be desorbed. H ₂ O (DI water): hydrogen peroxide (H ₂ O ₂ -conc.): Aqueous ammonia solution (NH ₃ Immerse the lens in a mixed solution of 5: 1: 1 (volume ratio) at 80 ° C for 10 minutes.

After the above 2 steps, the inactive silane group which may be present on the surface of the glass lens is changed into a silanol (-SiOH) group to activate the surface modification. H ₂ O (DI water): H ₂ O _2- Immerse the lens in a mixed solution of conc,: HCl = 6: 1: 1 (volume ratio) at 80 ° C for 10 minutes.

In this case, a quartz beaker or Teflon beaker is used to prevent recontamination from the container used.

The lens treated by the above procedure is washed with excess DI-water (about 500 ml) and dried under room temperature vacuum.

In the present invention, when the Si-OH group is sufficiently formed on the surface of the plastic lens in the surface Si-OH forming step, a process of increasing the density of Si-OH and a surface cleaning process are unnecessary, but the Si-OH density is low. In this case, as described above, the TEOS coating should increase the Si-OH density of the plastic lens surface. If the lens surface is contaminated during the coating process, the above-described surface cleaning process should be performed.

That is, the Si-OH density on the surface of the plastic lens should be sufficient before undergoing the functionalization process of silanol (-SiOH) described later.

C. Functionalization Step of Silanol

This step is to introduce a functional group capable of forming a more diverse and stronger chemical bond, although -SiOH itself formed on the surface of the plastic lens is a chemically reactive functional group.

One end of the compound used in this step must be able to react with -SiOH on the surface of the lens, and the other end has a structure having a surface functional group capable of various chemical reactions, wherein the surface functional group is vinyl (vinyl), epoxy ( epoxy), amine, and hydroxy.

The compound used in this step is a compound having three molecular structures shown below.

(1) a silane coupling compound having a trialkoxy group;

R ₁ (CH ₂ ) _n Si (OR ₂ ) ₃ , n = 0,1,2,3,4,5 ..

R ₁ = vinyl, epoxy, amine, hydroxy, benzyl

R ₂ = methyl, ethyl, propyl, buthyl,

(2) a silane coupling agent having a trihalogen group;

R ₁ (CH ₂ ) _n SiX ₃ , n = 0,1,2,3,4,5.6.8,9,11,18

R ₁ = vinyl, epoxy, amine, hydroxy, benzyl

X = Cl, Br

(3) other compounds; Introduction of chlorine (-Cl) groups to the surface by cyanuryl chloride

The process of coating the compound on the surface of the plastic lens is as follows.

Add one of the above compounds to a concentration of 1 to 2% in normal hexane (n-hexane) or toluene mixed solvent, adjust the mixed solution to 0-25 ℃, and put the lens for 5 minutes. Immersion causes chemical reactions on the surface.

After the post-treatment process to maximize the surface reaction, the compound that did not bind to the lens surface is washed with pure water and dried by heating to 60 ~ 70 ℃ under vacuum.

According to the present invention, the surface modification was performed by slightly varying the reaction conditions according to the chemical reactants. The surface-modified lens surface was analyzed by using a change in contact angle, attenuated total reflectance (IRT) -IR, and atomic force microscopy (AFM). According to the compound, the lens surface was modified with -amine, -glycidoxy, -vinyl, -hydroxy, and -chlorine.

D. Introduction of Hydrophilic Functional Groups

The hydrophilic ions of the surfactant firmly bound to the surface appear on the outermost surface of the lens by chemical bonding with the surface functional groups introduced in the functionalization step of the silanol, thereby producing a lens having a semi-permanent anti-fog function. .

At this time, the method of introducing a hydrophilic functional group is classified into three types.

The first method is to have a functional group capable of reacting with the surface functional group of the silanol functionalization step at one end and the other end with a compound having a hydrophilic functional group.

And the second is to convert the surface functional groups of silanol functionalization directly into hydrophilic functional groups.

Finally, in the functionalization step of silanol of step C described above, the lens surface is directly processed by a single process using R ₁ = chlorosulfonylphenyl (ClSO ₂ (C ₆ H ₄ )-) among the compounds represented by (1) and (2). A hydrophilic sulfonic acid group can be introduced into the.

1. The molecular structure and treatment method of the compound for introducing the hydrophilic functional group by the first method are as follows.

The molecular structure of the compound having a functional group capable of acting on the surface functional group of silanol functionalization and the other end having a hydrophilic functional group is as follows.

R ₁ (CH ₂ ) _n R ₂ , n = 0,1,2,3,4,5 ..

R ₁ = vinyl, styrene, epoxy, carbonyl, acrylate

R ₂ = SO ₃ H, SO ₃ Na, SO ₃ K, COOH, COONa, perfluoroalkyl sulfonate ion,

The procedure for introducing a hydrophilic functional group using the compound is as follows.

The reaction conditions were mixed by adding one of the above compounds to a concentration of 1% to 2% in pure water (DI water) solvent, the mixed solution was adjusted to 60 ~ 70 ℃, when the surface is modified with a vinyl group, a very small amount as a polymerization initiator Add one of AIBN (azobisisobutyronitrile), benzoyl peroxide, or potassium persulfate.

Immerse the lens in the above-mentioned solution for 5 minutes to 1 hour to induce chemical reaction with the surface functional groups in the functionalization step of silanol, wash the compound which did not bind to the lens surface with pure water, and then vacuum to 60 ~ 70 ℃. Heat drying.

The reaction conditions were slightly different depending on the chemical reactants to react with the surface functional groups in the functionalization of silanol.

2. The second method of hydrophilization is as follows.

The surface vinyl group in the functionalization stage of silanol is sulfonated by dipping the lens in a solution in which Na ₂ SO ₃ or NaHSO ₃ is dissolved in pure water in a weight ratio of 0.5 to 1% by weight, or silanol Lenses modified with hydroxy or benzyl hydroxy in the functionalization stage of were immersed in a mixture of 1.2-dichloroethane and ClSO ₃ H in a 10: 1 volume ratio.

In addition, the glass lens modified with an amine group, which is a surface functional group of silanol functionalization step, is reacted with sulfobenzoic acid cyclic anhydride group or various benzoyl acids, followed by mixing in a 10: 1 volume ratio of 1.2-dichloroethane and ClSO ₃ H. Treatment with one solution to sulfonate impart antifogging function.

3. And the surface of the lens was modified with -SO ₃ H, -COOH hydrophilic functional group by using some of the above 1 or 2 method, by final treatment with one aqueous solution of 1N NaOH, KOH, NaCl, KCl It should be converted to -SO ₃ Na, -COONa.

In this case, the same hydrophilic ion as the surfactant appears on the outermost surface of the lens, thereby producing a lens having excellent antifogging function.

In addition, by coating the lens already coated with -SO ₃ Na, -COONa hydrophilic in the same way, the hydrophilic function is activated and the water contact angle is reduced.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1.

As a solvent, a drop of triethylamine (HCl) was added to a solution having a volume ratio of VTC (vinyltrichlorosilane) in normal hexane (n-hexane) or toluene (toluene) at 60: 1, and the lens was kept at a temperature of 10 ° C. for 5 minutes. I soaked it.

After washing with normal hexane (n-hexane) or toluene (toluene) it was dried at 60 ℃. Isopropylalcohol (IPA), DI (water) and SSA (styrenesulfonic acid sodium salt) in a weight ratio of 50: 50: 0.1 or 200 ml of pure water in a solution of vinylsulfonic acid sodium salt (VSA) at 60 ° C for 5-60 minutes Soaked.

And washed with IPA and pure water, respectively.

The lens was immersed in a solution in which potassium persulfate was added to pure water and then washed with pure water.

Immerse in a solution of 1N NaOH for 30-60 minutes.

And it dried in the vacuum oven (vaccum oven) of 60 ℃.

Sample processing step Contact angle (°) Remarks Initial sample 15 After VTC Treatment 90 After VSA Treatment 20 After NaOH treatment 7

The anti-fog function of the present invention can be utilized for various purposes, and excellent application of durability and reproducibility is possible.

The present invention chemically bonds a compound having a hydrophilic functional group on the surface of the plastic lens to the lens surface to form a super hydrophilic thin film, so that the water contact angle is low, the fog is prevented, the antireflection function is not impeded, and the durability is excellent.

Claims (11)

Anti-fogging hydrophilization functional groups are prepared through a one-step reaction of Si-OH plastic lens surface coated with SiO ₂ using two compounds each having chemical reactivity at both ends, and a two-step reaction of the modified surface functional group. A method of forming a super hydrophilic thin film for surface coating a compound having. The surface-modified plastic lens surface Si-OH surface-coated with SiO ₂ using only one compound having chemical reactivity at both ends, and by the hydrophilic functional group conversion reaction of the modified surface functional group, Super hydrophilic thin film forming method for surface coating the compound. Ultra-thin surface-coated compounds with anti-fog hydrophilic functional groups by coating Si-OH coated with a plastic lens surface coated with SiO ₂ with functional groups capable of reacting with Si-OH and hydrophilic functional groups on both ends. Hydrophilic thin film formation method. [ ₄ ] The Si-OH density of the surface of the lens according to claim 1 or 2 or 3, wherein the surface of the lens is coated with a SiO ₂ coated plastic lens by coating a partially hydrated TEOS (Si (OCH ₂ CH ₃ ) ₄ ). Super hydrophilic thin film formation method to increase the. The method of claim 1 or 2, silane coupling compounds with trialkoxy groups; R ₁ (CH ₂ ) _n Si (OR ₂ ) ₃ , n = 0,1,2,3,4,5 .. R ₁ = vinyl, epoxy, amine, hydroxy, benzyl R ₂ = methyl, ethyl, propyl, buthyl, silane coupling agents having trihalogen groups; R ₁ (CH ₂ ) _n SiX ₃ , n = 0,1,2,3,4,5.6.8,9,11,18 R ₁ = vinyl, epoxy, amine, hydroxy, benzyl X = Cl, Br Other compounds; The chlorine (-Cl) group is introduced to the surface by cyanuryl chloride, Mix one of the above compounds in 1 ~ 2% concentration with normal nucleic acid or toluene mixed solvent by using, immerse the lens for 5 minutes at 0 ~ 25 ℃, wash with pure water and dry at 60 ~ 70 ℃ under vacuum. To coat with a compound having a surface functional group on the lens surface. In claim 1, R ₁ (CH ₂ ) _n R ₂ , n = 0,1,2,3,4,5 .. R ₁ = vinyl, styrene, epoxy, carbonyl, acrylate R ₂ = SO ₃ H, SO ₃ Na, SO ₃ K, COOH, COONa, perfluoroalkyl sulfonate ions, one of the compounds of pure water mixed in a concentration of 1 to 2% treated with a surface functional group at 60 ~ 70 ℃ A method of forming a super-hydrophilic thin film in which a lens is immersed for 5 minutes to 1 hour, washed with pure water, and dried under vacuum at 60 to 70 ° C. to coat a hydrophilic functional group. The method of claim ₂ , wherein the lens modified by the vinyl group by the surface functional group is sulfonated by dipping in a solution in which Na ₂ O ₃ or NaHSO ₃ with a weight ratio of 0.5 to 1 weight is dissolved in pure water. . The method of claim ₂ , wherein the lens modified with a hydroxy or benzyl hydroxy group by the surface functional group is coated with a solution containing 1.2-dichloroethane and ClSO ₃ H in a 10: 1 volume ratio and sulfonated. In claim 2, the lens modified by the amine group by the surface functional group is reacted with a sulfobenzoic acid cyclic anhydride group or benzoyl acil, and then treated with a solution mixed in a 10: 1 volume ratio of 1.2-dichloroethane and ClSO ₃ H to sulphonate Hydrophilic thin film formation method. In the trialkoxy silane coupling compound or trihalogen silane coupling compound, R ₁ = chlorosulfonylphenyl (ClSO ₂ (C ₆ H ₄ )-) and R ₂ is a hydrophilic sulfonated lens surface directly by a single process using the same compound. Super hydrophilic thin film formation method. According to claim 1 or 2 or 3, the surface of the lens modified with -SO ₃ H, -COOH hydrophilic functional group by the final treatment with one aqueous solution of NaOH, KOH, NaCl, KCl of 1N Super hydrophilic thin film formation method to prevent.