KR101166081B1 - Composition comprising polymer latex particle for antireflective surface and preparation method of single layer porous antireflective surface using it - Google Patents

Abstract

The present invention relates to a method for producing an antireflection film required for various display surfaces and surfaces of optical materials using a composition containing an alkali-soluble polymer emulsion and polymer latex particles.
Using the composition of the present invention, it is possible to form a low refractive index porous antireflection film without limitation of substrate, economical, fast production speed, and environmentally harmful. In addition, the coating can be applied on the high refractive index layer as well as the single layer anti-reflection film, and thus it can be applied to the production of an anti-reflection film having a two-layer structure.

Description

Composition comprising polymer latex particle for antireflective surface and preparation method of single layer porous antireflective surface using it}

The present invention relates to a method for producing an antireflection film required for various display surfaces and surfaces of optical materials using a composition containing an alkali-soluble polymer emulsion and polymer latex particles.

When light is transmitted through the transparent substrate, a portion of light is reflected due to the difference in refractive index between the substrate and the medium. Therefore, various optical materials such as lenses, reflectors, and low pass filters used in microscopes, cameras, glasses, and the like, or surface of display devices such as liquid crystal displays (LCDs), plasma displays (PDPs), and organic light emitting diodes (OLEDs). It is common to form a low reflection film or an anti-reflection film to reduce the reflectance. As a result, the light transmittance is improved and the effect of preventing the deterioration of the visibility of the screen or the glare is exhibited.

The basic principle of reflectance reduction is to form a thin film having a lower refractive index than the substrate so that the reflected light reflected at the surface of the thin film and the reflected light reflected at the thin film-substrate interface are canceled out by interference. However, since even fluorine compounds having the lowest refractive index among the known materials have refractive indices of 1.35 or more, a single layer film does not exhibit satisfactory antireflection performance. Therefore, antireflection film formation using two or more multilayer films is generally used. . For example, Japanese Laid-Open Patent Publication No. 2009-230121 discloses an antireflection film having a reflectance of vertical incident light of 0.3% or less in a wavelength region of 400 to 700 nm by sequentially stacking first to seventh layers on a substrate. .

Currently, a single layer or a multi-layered anti-reflection film is formed on the surface of various glass by dry processes such as vacuum deposition, sputtering, ion plating, and CVD to prevent reflected light. The substrate size is limited by the constraints of the device and is not suitable for large area coatings such as displays. In addition, in the case of irregularities on the surface of the substrate, uniform coating cannot be performed. In particular, in the vacuum deposition method, the substrate must be 300 ° C. or more in order to make the strength of the antireflection film strong enough for long-term use, and the sputtering method has a problem that the equipment cost is considerably expensive.

As an alternative to this, various wet coating techniques have been proposed. Wet coating has the advantage that it is possible to mass-produce by a continuous process by coating the coating material on the substrate in solution form and the manufacturing cost is lower than the dry process. However, since the thin film of the multi-layered structure must precisely control the thickness and refractive index of each layer, the manufacturing cost is high and the defect rate is increased. Therefore, the current wet process is used to manufacture a two-layer antireflection film in which a high refractive index layer and a low refractive index layer are sequentially stacked as disclosed in Korean Patent Laid-Open Publication No. 2009-0043397, and in order to obtain a higher level of antireflection performance, Layered membranes are also used. Fluorine-based polymers are mainly used as coating materials for the low refractive index layer, and it is known to add porous or hollow silica to lower the refractive index (Japanese Patent Laid-Open No. 2009-069317, International Patent WO 2008/019077, Japanese Laid-Open Patent Publication). Patent 2005-165010, Japanese Patent Laid-Open No. 2006-208991, Japanese Patent Laid-Open No. 2006-209050, and US Patent US2007 / 0196667).

In the case of a multilayer anti-reflection film, interference fringes may occur due to a difference in refractive index and a nonuniformity in thickness, so it is advantageous to develop an anti-reflection film having a single layer structure as much as possible to improve productivity. It is well known that if the square of the refractive index of a single layer is equal to the refractive index of the substrate, the reflectance becomes zero at a specific wavelength. Various methods have been proposed to manufacture such a single layer anti-reflection film, which has a common point of forming a porous coating layer containing a large amount of pores in order to have a refractive index of the coating layer in the range of 1.20 to 1.30.

Japanese Patent Laid-Open No. 6-167601 discloses a method of forming a porous antireflection film by depositing a SiO ₂ and NaF mixed film and then removing the water-soluble NaF. Japanese Patent Laid-Open No. 6-345487 and Japanese Patent Laid-Open No. 2001-272506 disclose a method for producing a porous membrane mainly composed of silica by forming a thin film on a display screen by a sol-gel method and by rapid heat treatment or light irradiation. In addition, a number of techniques for forming a porous thin film by selectively removing the additive by a method such as heat treatment, solution extraction, and the like after curing by curing the curable material with an additive (porogen) capable of fine phase separation (Japanese Patent Laid-Open No. 2006-) 131881, Japanese Patent Publication No. 2007-004155, Korean Patent Publication No. 2008-0103215, Korean Patent Publication No. 2009-0053348, Japanese Patent Publication No. 2009-237551)

However, since these methods require heat treatment at very high temperatures, they cannot be applied to polymer substrates with low glass transition temperature, such as polymethyl methacrylate and polycarbonate. There are many things that need to be improved.

Accordingly, the present inventors have studied and tried to produce a low refractive index anti-reflection film that is not limited to a substrate, and is environmentally friendly and economical, and has a high production speed. As a result, the polymer latex particles made of an alkali-soluble polymer emulsion and a fluorine-containing acrylate monomer are mixed. The present invention was completed by discovering that after coating and heat-treating the prepared composition, alkali treatment can produce a porous monolayer antireflection film having excellent antireflection performance.

Accordingly, an object of the present invention is to provide a composition for preparing an antireflection film, in which a polymer latex particle made of a polymer emulsion and a fluorine-containing acrylate monomer is mixed, and a method for producing the antireflection film using the same.

The present invention,

Unsaturated carboxylic acid monomers,

Alkali-soluble polymer emulsions in which at least one monomer selected from acrylate monomers, methacrylate monomers and styrene monomers is polymerized; And

Polymer latex particles made of fluorine-containing acrylate monomers

It characterized by the composition for producing an anti-reflection film comprising a.

Further, according to the present invention,

Coating and heat-treating the composition on a substrate; And

Treating alkaline solution with pH 7.0 ~ 12.0

It is another feature of the method for producing a porous anti-reflection film comprising a.

Using the composition of the present invention, it is possible to form a low refractive index porous antireflection film without limitation of substrate, economical, fast production speed, and environmentally harmful. In addition, the coating can be applied on the high refractive index layer as well as the single layer anti-reflection film, and thus it can be applied to the production of an anti-reflection film having a two-layer structure.

1 is a photograph of the surface of the porous monolayer antireflection film prepared according to Example 1 of the present invention under a scanning electron microscope.
2 is a reflectance graph of the porous single layer antireflection film prepared according to Example 1 of the present invention.

The present invention provides an alkali-soluble polymer emulsion in which an unsaturated carboxylic acid monomer and at least one monomer selected from an acrylate monomer, a methacrylate monomer and a styrene monomer are polymerized; And it is characterized by a composition for producing an anti-reflection film comprising a polymer latex particles made of a fluorine-containing acrylate monomer.

The alkali water-soluble polymer emulsion may be removed by an alkaline aqueous solution after coating on a substrate, and prepared by polymerizing at least one monomer selected from acrylate monomers, methacrylate monomers and styrene monomers with an unsaturated carboxylic acid monomer. do.

The unsaturated carboxylic acid monomer constituting the alkali water-soluble polymer emulsion may be a compound having a carboxylic acid functional group capable of being ionized, and one or two or more compounds selected from methacrylic acid, acrylic acid, itaconic acid, crotonic acid and maleic acid may be used.

The carboxylic acid functional group becomes soluble or insoluble in aqueous solution depending on the acidity (pH) of the surrounding environment. If the pH of the aqueous solution is weakly alkaline than the pKa of the carboxylic acid, it is completely dissolved. On the contrary, if the acidity is lower than the pKa, the aqueous solution has a spherical nanoparticle form.

In the present invention, the unsaturated carboxylic acid monomer is 5 to 50% by weight, preferably 10 to 40% by weight in the total alkali water-soluble polymer emulsion. When the content of the unsaturated carboxylic acid monomer is less than 5% by weight, even if the pH of the aqueous solution is high, it is insoluble in water.

 The alkali water-soluble polymer emulsion is prepared by further polymerizing a unsaturated carboxylic acid monomer and a comonomer capable of emulsion polymerization, and using at least one monomer selected from an acrylate monomer, a methacrylate monomer, and a styrene monomer.

The acrylate monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, ter-butyl acrylate, hexyl acrylate, ethyl-hexyl acrylate and 2, One or two or more compounds selected from 2,2-trifluoroethyl acrylate are used.

In addition, the methacrylate monomers are methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, ter-butyl methacrylate, hexyl methacrylate One, two or more compounds selected from ethyl-hexyl methacrylate and 2,2,2-trifluoroethyl methacrylate are used.

In addition, the styrene-based monomer is used one or two or more compounds selected from styrene, α-methyl styrene.

More preferably, it is advantageous to manufacture an antireflection film as the alkali water-soluble polymer emulsion uses a compound represented by the following formula (1).

In the above formula, R ₁ is H, CH ₃ or CH ₂ COOH; R ₂ and R ₃ are each H or CH ₃ ; R4 is An alkyl group of C ₁ to C ₆ ; X is H, CH ₃ or COOH, wherein a, b, c are weight fractions of each monomer, and the ratio of a: b + c has a value within the range of 0.1: 0.9 to 0.4: 0.6.

The alkali water-soluble polymer emulsion preferably has a diameter of 15 to 500 nm, and more preferably 30 to 200 nm. If the particle size is too small, a large amount of surfactant should be used and it is economically disadvantageous because the solid content of the emulsion polymer cannot be high. If the particle size is too large, the pore size in forming a porous anti-reflection film thereafter. It becomes larger and may cause haze by scattering of light, which is disadvantageous in uniformly distributing pores in the coating layer. However, the distribution of particle size is not so limited, so it is not necessarily a monodisperse form of constant size.

In addition, the alkali water-soluble polymer emulsion preferably has a molecular weight of 3,000 to 50,000 in weight average, and most preferably a weight average molecular weight of 5,000 to 30,000. In order to reduce the weight average molecular weight of the alkali water-soluble polymer emulsion below the above range, a large amount of chain transfer agent should be used. In this case, the reaction takes a very long time and it is not easy to maintain a high final conversion rate of the monomer. If the molecular weight of the alkali water-soluble polymer emulsion is too large, it takes a long time to form a porous anti-reflection film by removing it with a weakly alkaline aqueous solution, and the coating layer is not removed due to a decrease in solubility of the polymer chain. There remains a problem of remaining in the optical fiber and deteriorating the optical characteristics.

The alkali water-soluble polymer emulsion may be prepared through emulsion polymerization by a known method. In other words, after adding ion-exchanged water, anionic surfactant, sodium bicarbonate, and water-soluble polymerization initiator to the reactor, the temperature is raised to the reaction start temperature with stirring, and then a solution containing a monomer and a chain transfer agent for molecular weight control is slowly introduced into the reactor. do. After the addition of the mixed solution is completed, the reaction is continued to increase the final conversion of the monomers and then filtered using a paper filter to prepare an alkali water-soluble polymer emulsion.

On the other hand, the anti-reflective coating composition of the present invention comprises a polymer latex particles in addition to the alkali water-soluble polymer emulsion and the latex particles may be a coalescence between the particles by heat treatment to produce a film. In addition, if the refractive index of the polymer latex film after film formation is high, the ratio of pores should be increased in order to reduce the reflectance. In this case, mechanical properties such as friction resistance are reduced. Therefore, it is not preferable to use polymer latex particles composed of only general acrylate monomers, methacrylate monomers and styrene monomers.

Monomers containing a fluorine atom in the molecular structure has a low refractive index, and when the porous antireflection film is formed using such a fluorine-containing monomer, a sufficiently low reflectance can be obtained even with a pore of about 30 to 50% by volume. Thus, the polymer latex particles of the present invention are 2,2,2, -trifluoroethyl (meth) acrylate, 1,1,1,3,3,3-hexafluoroisopropyl (meth) acrylate, 2 , 2,3,3,4,4,4-heptafluorobutyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2,2,3,4 , 4,4-hexafluorobutyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 4,4,5,5,6,6,7,7,8 , 8,9,9,9-tridecafluoro-2-hydroxynonyl (meth) acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8 -Tridecafluorooctyl (meth) acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluoro One or two or more selected from decyl (meth) acrylate, 2,2,3,3,4,4,5,5-octafluorophenyl (meth) acrylate and the compound represented by the following formulas (2) to (4): The fluorine-containing monomer is selected and prepared.

N is an integer of 1 to 30, R is H or CH ₃ in the above formula.

In preparing the polymer latex particles capable of forming a film, various functional monomers may be added in a range in which the refractive index of the film does not exceed 1.45 or more in addition to the fluorine-containing monomer. Such functional monomers include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycidyl (meth) acrylate, 2- ( Diethylamino) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like can be used. Can be.

The polymer latex particles can be prepared through emulsion polymerization by a generally known method. That is, ion-exchanged water, anionic surfactant, sodium bicarbonate, and a chain transfer agent and a monomer mixture for molecular weight control are emulsified using an emulsifier, and then charged into a reactor, and then heated to the reaction start temperature with stirring, followed by a water-soluble initiator. To initiate the reaction. The reaction may be continued for a certain time to increase the final conversion of the monomers, and then filtered using a paper filter to obtain polymer latex particles.

The polymer latex particles are preferably in the range of 15 to 500 nm in diameter, more preferably in the range of 30 to 300 nm. If the particle size is too small, a large amount of surfactant must be used and it is economically disadvantageous because the solid content of the emulsion polymer cannot be high. If the particle size is too large, the process becomes complicated because two or more steps are required. There is a disadvantage, and it is not easy to precisely control the thickness of the porous monolayer antireflection film. However, the distribution of particle size is not so limited, so it is not necessarily a monodisperse form of constant size.

The glass transition temperature of the polymer latex particles that can form a film preferably has a value between 25 and 150 ° C., and preferably has a value of 50 ° C. or more. If the glass transition temperature is lower than this, there is a risk that the pores disappear due to deformation of the film even at room temperature, and there is a problem that the stickiness is felt upon contact.

Meanwhile, the present invention provides a method for preparing a porous anti-reflection film comprising coating and heat-treating the composition composed of an alkali-soluble polymer emulsion and polymer latex particles, and treating an alkaline solution having a pH of 7.0 to 12.0. Include.

First, the anti-reflection coating coating solution is prepared by mixing the alkali-soluble polymer emulsion and the polymer latex particles, but the mixing ratio of the water-soluble polymer emulsion and the polymer latex particles is not particularly limited, and the higher the proportion of the alkali-soluble polymer emulsion in the coating solution, the more pores. As a result, it is possible to form a porous coating layer having a low effective refractive index. However, when coating on a glass substrate, it is required to adjust the refractive index of the coating layer to about 1.23 in order to set the reflectance to 0 at a specific wavelength of light. For this purpose, the mixing ratio of the alkali-soluble polymer emulsion and the polymer latex particles is weight ratio. It is preferable to adjust in the range of 25:75 to 60:40.

The total amount of solids in the coating solution may be controlled by a coating method, and in the case of general spin coating, the rotational speed is preferably adjusted in the range of 3 to 10 wt% at 1500 to 4000 rpm, and the amount of solids in the coating solution It is possible to adjust the thickness of the single layer antireflection film by appropriately adjusting the rotation speed.

The thickness of the coated anti-reflection film is determined by which wavelength the minimum reflectance is desired to be obtained. For example, when the thickness of the coating layer is 80, 100, 120, or 150 nm, respectively, 400, 490, 590, and 735 nm The reflection of light at the wavelength is minimized. In general, the thickness is preferably in the range of 80 to 200 nm.

As a base material which can form a porous monolayer antireflection film, it is applicable not only to general glass but also to plastic base materials, such as polymethylmethacrylate, polycarbonate, polystyrene, PET, and a triacetyl cellulose film, by the same method. These substrates are required to clean the surface through ultraviolet-ozone treatment or the like.

There is no particular limitation on the method of coating the anti-reflection coating solution solution. In general, it can be selected and used according to the characteristics of the substrate, such as spin coating, deposition coating, spray coating, roll coating that can be industrially applied.

Next, the coated antireflection film composition is heat treated to form a polymer latex film. Since the coating layer formed by the coating can be easily removed because only the particles are stacked, the film is heat-treated at a temperature higher than the glass transition temperature of the polymer latex particles capable of forming a film. If the polymer latex particles can be deformed to form a film, there is no great limitation on the heat treatment temperature or time.

Thereafter, an alkali water-soluble polymer emulsion is selectively removed from the heat treated polymer latex mixture film to prepare a porous single layer anti-reflection film. At this time, the alkaline solution used to selectively remove the polymer emulsion needs to have a basicity of pH 7-12, more preferably pH 7.5-10. In order to adjust the pH of the aqueous solution, it is common to use sodium hydroxide, potassium hydroxide, ammonia, triethylamine and the like, but there is no particular limitation as long as it can be adjusted within the pH range. After forming a porous antireflection layer using an alkaline solution, it is washed again with distilled water and dried at room temperature to obtain a porous antireflection film.

Hereinafter, the present invention will be described in more detail based on the following examples, but the present invention is not limited to the following examples.

Example 1

(1) Synthesis of Alkali Water Soluble Polymer Emulsion

Into a 500 mL three-necked flask equipped with a thermometer and a raw material inlet, 200 mL of tertiary distilled water, 0.2 g of sodium bicarbonate, 0.5 g of dodecyl sulfate sodium salt, 0.3 g of sodium persulfate were stirred using a magnetic stirrer, and stirred in an oil chamber. The temperature was raised to 70 ° C. The monomer solution which mixed 15 g of methacrylic acid, 35 g of methyl methacrylate, and 1 g of 1-octyl mercaptans was introduce | transduced into the reactor at the flow rate of 60 mL / hr using the syringe pump. After the completion of the addition of the monomer mixture was stirred for 6 hours, the emulsion obtained was filtered to complete the preparation of an alkali water-soluble polymer emulsion having a solid content of 20% by weight. The particle size of the alkali-soluble polymer emulsion thus obtained was 50 nm, and the weight average molecular weight was 16500 and the glass transition temperature was 135 ° C. as a result of gel chromatography analysis.

(2) synthesis of polymer latex particles capable of film formation

5 g of 2,2,2, -trifluoroethyl methacrylate, 1 g of 2-hydroxyethyl methacrylate, and 0.1 g of 1-octyl mercaptan, 0.2 g of sodium bicarbonate and 1.0 g of dodecyl sulfate sodium salt were distilled water It was put into 140 mL, emulsified using an ultrasonic emulsifier, and put into a 500 mL three-necked flask equipped with a thermometer and a raw material inlet, and the temperature in the oil thermostat was raised to 80 ° C. while stirring using a magnetic stirrer. 0.3 g of sodium persulfate was added thereto to initiate the reaction. 30 minutes after the start of the reaction, 45 g of 2,2,2, -trifluoroethyl methacrylate, 9 g of 2-hydroxyethyl methacrylate, and 0.9 g of 1-octyl mercaptan, 0.5 g of dodecyl sulfate sodium salt, and tertiary distilled water The emulsion was emulsified in 100 mL and injected into the reactor at a flow rate of 30 mL / hr using a syringe pump. After the addition of the monomer mixture was stirred for 6 hours, the resulting emulsion was filtered to prepare polymer latex particles having a solid content of 20% by weight. The obtained polymer latex particles had a size of 45 nm as a result of electron microscopy analysis, and the glass transition temperature was 65 ° C. using a differential scanning calorimeter.

(3) Formation of porous monolayer antireflection film

After diluting the obtained alkali-soluble polymer emulsion (A) and polymer latex particles (B) with tertiary distilled water to 5 wt%, 3.5 mL of A dilution and 6.5 mL of B dilution were mixed to prepare a coating solution. . The 0.4 mL coating solution was spin-coated at a speed of 2000 rpm for 35 seconds on a 2.5 cm × 2.5 cm sized glass substrate with a refractive index of 1.52 cleaned of the surface by UV-ozone treatment to form a single layer. Then it was heat treated at a temperature of 120 ℃ for 1 hour. The heat-treated glass substrate was immersed in an aqueous solution adjusted to pH 9.5 using sodium hydroxide and gently shaken to selectively remove the alkaline water-soluble polymer emulsion. The surface was washed with a large amount of distilled water and dried at room temperature to obtain a porous single A layer antireflection film was prepared.

The transmittance of the prepared monolayer antireflection film was measured in the visible light region having a wavelength of 400 nm to 800 nm by using an ultraviolet / visible spectroscope, and the reflectance was attached to the ultraviolet / visible spectroscope by attaching an absolute reflection accessory to the incident angle. The specular reflectance of this 5 가시 visible ray was measured. When measuring the reflectance of the porous monolayer antireflection film, the back side of the glass substrate was painted black using paint to prevent reflection occurring on the back side of the glass substrate. The thickness and effective refractive index of the porous monolayer antireflection film were measured using a spectroscopic ellipsometer, and the results are shown in Table 1 below. Porosity of the porous monolayer antireflection film was calculated using the following Equation 1 from the measured effective refractive index.

[Equation 1]

In the above equation, n _eff is the effective refractive index of the porous monolayer film, n is the refractive index of the material constituting the film.

Examples 2-8

Except that the mixing ratio of the alkali water-soluble polymer emulsion (A) and the polymer latex particles (B) in the coating solution was changed as shown in Table 1, the porous monolayer antireflection film was prepared in the same manner as in Example 1 to measure physical properties. The results are shown in Table 1 below.

Example 9

The alkali-soluble polymer emulsion (A) and the polymer latex particles (B) were diluted with tertiary distilled water to 4 wt%, respectively, except that 3.5 mL of A dilution and 6.5 mL of B dilution were mixed to prepare a coating solution. Was prepared in the same manner as in Example 1 to measure the physical properties of the porous anti-reflection film, the results are shown in Table 1 below.

Example 10

Except for preparing a coating solution by diluting the alkali water-soluble polymer emulsion (A) and the polymer latex particles (B) with tertiary distilled water to 6 wt%, and then mixing 3.5 mL of A dilution and 6.5 mL of B dilution. Was prepared in the same manner as in Example 1 to measure the physical properties of the porous anti-reflection film, the results are shown in Table 1 below.

Example 11

(1) Synthesis of Alkali Water Soluble Polymer Emulsion

Into a 500 mL three-necked flask equipped with a thermometer and a raw material inlet, 200 mL of tertiary distilled water, 0.1 g of sodium bicarbonate, 0.3 g of sodium dodecyl sulfate, 0.3 g of sodium persulfate were added and stirred using a magnetic stirrer. The temperature was raised to 70 ° C. A monomer solution obtained by mixing 15 g of methacrylic acid, 25 g of methyl methacrylate, 10 g of styrene, and 1 g of 1-octyl mercaptan was introduced into the reactor at a flow rate of 60 mL / hr using a syringe pump. After the completion of the addition of the monomer mixture was stirred for 6 hours, the emulsion obtained was filtered to complete the preparation of an alkali water-soluble polymer emulsion having a solid content of 20% by weight. The particle size of the alkali-soluble polymer emulsion thus obtained was 75 nm, and the weight average molecular weight was 12000, and the glass transition temperature was 125 ° C. as a result of gel chromatography analysis.

(2) synthesis of polymer latex particles capable of film formation

5 g of 2,2,2, -trifluoroethyl methacrylate, 1 g of 2-hydroxyethyl methacrylate, and 0.1 g of 1-octyl mercaptan, 0.2 g of sodium bicarbonate and 1.0 g of dodecyl sulfate sodium salt were distilled water It was put into 140 mL, emulsified using an ultrasonic emulsifier, and put into a 500 mL three-necked flask equipped with a thermometer and a raw material inlet, and the temperature in the oil thermostat was raised to 80 ° C. while stirring using a magnetic stirrer. 0.3 g of sodium persulfate was added thereto to initiate the reaction. 30 g after the start of the reaction, 25 g of 2,2,2, -trifluoroethyl methacrylate, 20 g of a methacrylate derivative (n = 6, R = CH ₃ ) of a perfluoropolyether compound represented by the following Chemical Formula 2, 2- 9 g of hydroxyethyl methacrylate and 0.9 g of 1-octylmercaptan were added 0.5 g of dodecyl sulfate sodium salt to 100 mL of tertiary distilled water, and the emulsion was emulsified using an ultrasonic emulsifier using a syringe pump using a syringe pump. Into the reactor. After the addition of the monomer mixture was stirred for 6 hours, the resulting emulsion was filtered to prepare polymer latex particles having a solid content of 20% by weight. The obtained polymer latex particles had an electron microscope analysis, and the particle size was 80 nm, and the glass transition temperature was 55 ° C. using a differential scanning calorimeter.

[Formula 2]

(3) Formation of porous monolayer antireflection film

After diluting the obtained alkali-soluble polymer emulsion (A) and polymer latex particles (B) with tertiary distilled water to 5 wt%, respectively, 2.0 mL of A dilution and 8.0 mL of B dilution were mixed to prepare a coating solution. . The 0.4 mL coating solution was spin-coated at a speed of 2000 rpm for 35 seconds on a 2.5 cm × 2.5 cm sized glass substrate with a refractive index of 1.52 cleaned of the surface by UV-ozone treatment to form a single layer. Then it was heat treated at a temperature of 120 ℃ for 1 hour. The heat-treated glass substrate was immersed in an aqueous solution adjusted to pH 9.5 using sodium hydroxide and gently shaken to selectively remove the alkaline water-soluble polymer emulsion. The surface was washed with a large amount of distilled water and dried at room temperature to obtain a porous single A layer antireflection film was prepared.

The transmittance of the prepared monolayer antireflection film was measured in the visible light region having a wavelength of 400 nm to 800 nm by using an ultraviolet / visible spectroscope, and the reflectance was attached to the ultraviolet / visible spectroscope by attaching an absolute reflection accessory to the incident angle. The specular reflectance of this 5 가시 visible ray was measured. When measuring the reflectance of the porous monolayer antireflection film, the back side of the glass substrate was painted black using paint to prevent reflection occurring on the back side of the glass substrate. The thickness and effective refractive index of the porous monolayer antireflection film were measured using a spectroscopic ellipsometer, and the results are shown in Table 1 below.

Examples 12-15

Except that the mixing ratio of the alkali water-soluble polymer emulsion (A) and the polymer latex particles (B) in the coating solution was changed as shown in Table 1, the porous monolayer antireflection film was prepared in the same manner as in Example 11 to measure physical properties. The results are shown in Table 1 below.

Comparative Example 1

After diluting only the polymer latex particles (B) prepared in Example 1 to 5 wt% using tertiary distilled water, 0.4 mL of the diluting solution was coated on a glass substrate in the same manner as in Example 1, followed by heat treatment. A layer film was prepared and the physical properties were measured and the results are shown in Table 1 below.

Comparative Example 2

After diluting only the polymer latex particles (B) prepared in Example 11 to 5 wt% using tertiary distilled water, 0.4 mL of the diluting solution was coated on a glass substrate in the same manner as in Example 1, and heat treated. A layer film was prepared and the physical properties were measured and the results are shown in Table 1 below.

A / B
(mL / mL) Reflectance
(%) Reflection
Wavelength (nm) Average reflectance (%) available
Refractive index Porosity thickness
(nm) Example 1 3.5 / 6.5 0.05 630 0.58 1.26 0.46 127 Example 2 1.0 / 9.0 1.75 644 2.27 1.41 0.08 114 Example 3 2.0 / 8.0 0.40 655 1.34 1.31 0.32 126 Example 4 3.0 / 7.0 0.10 645 1.01 1.27 0.42 128 Example 5 4.0 / 6.0 0.06 635 0.64 1.21 0.58 121 Example 6 5.0 / 5.0 0.18 555 0.71 1.18 0.63 119 Example 7 6.0 / 4.0 0.22 535 0.80 1.17 0.65 121 Example 8 7.0 / 3.0 2.04 350 2.36 1.12 0.77 78 Example 9 3.5 / 6.5 0.09 435 0.78 1.27 0.46 105 Example 10 3.5 / 6.5 0.10 700 0.86 1.26 0.49 138 Example 11 2.0 / 8.0 0.50 630 0.99 1.32 0.24 120 Example 12 3.0 / 7.0 0.13 630 0.67 1.28 0.36 124 Example 13 4.0 / 6.0 0.03 630 0.49 1.24 0.46 122 Example 14 5.0 / 5.0 0.12 635 0.58 1.19 0.58 127 Example 15 6.0 / 4.0 0.41 635 0.81 1.16 0.66 125 Comparative Example 1 0 / 10.0 2.35 666 2.89 1.44 0 116 Comparative Example 2 0 / 10.0 1.78 615 2.07 1.41 0 110

As shown in Table 1, the porous monolayer antireflection film prepared from the composition of the embodiment containing the alkali water-soluble polymer emulsion has a very low effective refractive index and minimum reflectance compared to the antireflection film of the comparative example does not contain pores, coating It was confirmed that the effective refractive index can be precisely controlled by adjusting the ratio of the alkali water-soluble polymer emulsion (A) in the solution.

Claims (14)

delete delete delete delete delete delete delete delete delete delete delete Unsaturated carboxylic acid monomers; An alkali-soluble polymer emulsion comprising an alkali-soluble polymer compound represented by the following Chemical Formula 1, in which at least one monomer selected from an acrylate monomer, a methacrylate monomer, and a styrene monomer is polymerized; And coating and heat-treating the antireflection film composition comprising a polymer latex particle made of a fluorine-containing acrylate monomer on a substrate;
Treating alkaline solution with pH 7.0 ~ 12.0
Method for producing a porous antireflection film comprising:
[Formula 1]

In Formula 1, R ₁ is H, CH ₃ or CH ₂ COOH; R ₂ and R ₃ are each H or CH ₃ , and R ₄ is a C ₁ to C ₆ alkyl group; X is H, CH ₃ or COOH, wherein a, b, c are weight fractions of each monomer, and the ratio of a: b + c has a value within the range of 0.1: 0.9 to 0.4: 0.6.
13. The method of claim 12, wherein the coating of the composition is made of a thickness of 80 ~ 200 nm.
The method of claim 12, wherein the effective refractive index of the anti-reflection film is in the range of 1.20 ~ 1.30.

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