KR101257144B1 - Light diffusion plate, method for manufacturing the same and backlight device comprising the same, and liquid crystal display device - Google Patents

Abstract

The present invention relates to a light diffusing plate, a manufacturing method thereof, a backlight device and a liquid crystal display device having the same, and specifically, even when the light diffusing plate is used for a backlight surface light source, charging of the light diffusing plate is not affected. It improves the prevention property, and also maintains the excellent antistatic property even after the water washing process in the process, the production process is simplified, and the production stability also has an excellent advantage.

Light diffusion plate, antistatic agent, backlight device, liquid crystal display device

Description

LIGHT DIFFUSION PLATE, METHOD FOR MANUFACTURING THE SAME AND BACKLIGHT DEVICE COMPRISING THE SAME, AND LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a light diffusion plate, a manufacturing method thereof, a backlight device having the same, and a liquid crystal display device.

Transparent resins used in the light diffusion plate include methacrylate resins, polycarbonate resins, cycloolefin resins, polystyrene resins, and the like having excellent light transmittance. In the case of such a resin, the light transmittance is excellent, but there is a problem in light diffusivity, so that various light diffusing agents are added and used to have a light diffusing function. Generally, the light diffusing agent used here uses organic and inorganic fine particles having a refractive index of about 1.0 to 1.9.

However, diffusion plates based on polycarbonate, polymethacrylate, polystyrene-based and cyclic olefin-based resins have a minimum function as a light-diffusing member, but have problems such as adhesion of dust when incorporated into a surface light source. In some cases, display unevenness may occur on the liquid crystal display according to changes in the use environment, and provision of antistatic performance is required.

In general, a method of imparting antistatic performance to a diffuser plate is performed using conductive carbon black or a conductive polymer. However, they have black or blue color, which are difficult to apply, and may cause optical problems even when a thin coating is possible. It is possible to obtain a high brightness is not economically burdensome.

In addition, the internal additive type antistatic agent has a lot of compatibility problems with the resin, the actual coextrusion method during manufacturing, the surface area of the diffusion plate is difficult to meet the process conditions, the amount of use is relatively high.

In addition, the external coating type antistatic agent is simple to use and does not require special process technology, but is generally removed in the washing process for removing dust or foreign matter after cutting the diffusion plate in an ionic or nonionic form. Prevention performance is lost.

In order to provide such antistatic performance, an antistatic agent which is easy to use and economical is required while maintaining the antistatic performance even after washing with high brightness.

The present invention does not affect the reduction in luminance even when used as a backlight surface light source, to provide a light diffusion plate that maintains antistatic performance even after washing, a manufacturing method thereof, a backlight device and a liquid crystal display device having the same.

One embodiment of the invention the diffusion substrate layer; And it is a light diffusion plate comprising a coating layer having an organic fluorine-based ammonium ammonium salt represented by the formula (1).

≪ Formula 1 >

(Wherein R ¹ and R ² are each independently a fluorine sulfonyl group,

R ³ to R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group.)

Another embodiment of the present invention is that the coating layer is a light diffusion plate having a thickness of 0.001 to 10㎛.

According to another embodiment of the present invention, the light diffusion plate has a surface resistance change value of 10 ¹ Ω / sq before and after washing when the water diffusion process is performed by spraying for 10 seconds at a pressure of 0.1 MPa at a temperature of 25 ° C. It is a light-diffusion plate below.

According to another embodiment of the present invention, the coating layer has a weight ratio of the organic fluorine-based ammonium imide acid salt represented by the formula (1) to the ultraviolet absorber to the antioxidant of 1: 2 to 10: 1 to 10.

Another embodiment of the present invention is an organic fluorine-based ammonium salt represented by the formula (1) is a light diffusion plate, characterized in that the fluorine-based sulfonyl ammonium salt represented by the formula (2).

<Formula 2>

According to another embodiment of the present invention, a light diffusion plate comprising forming a coating layer on a surface of a diffusion substrate layer by using a spray coating method on a coating liquid including an organic fluoride-based ammonium salt of ammonium salt and an organic solvent It is a manufacturing method of.

&Lt; Formula 1 >

(Wherein R ¹ and R ² are each independently a fluorine sulfonyl group,

R ³ to R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group.)

Another embodiment of the present invention is a method for producing a light diffusion plate, characterized in that the coating solution comprises 0.01 to 50% by weight of an organic fluorine-based ammonium imide acid salt represented by Formula 1 and 50 to 99.99% by weight of an organic solvent. .

According to another embodiment of the present invention, the coating solution further includes 2 to 10 parts by weight of an ultraviolet absorber and 1 to 10 parts by weight of an antioxidant based on 1 part by weight of the organic fluorine-based ammonium ammonium salt represented by Chemical Formula 1. It is a method of manufacturing a light diffusion plate.

Another embodiment of the present invention is an organic fluoride-based ammonium salt represented by the formula (1) is a method for producing a light diffusion plate, characterized in that the fluorine-based sulfonyl ammonium salt represented by the formula (2).

<Formula 2>

Another embodiment of the present invention is a backlight device including the light diffusion plate.

Another embodiment of the present invention is a liquid crystal display device including the backlight device.

The light diffusing plate according to the present invention, a method of manufacturing the same, a backlight device and a liquid crystal display device having the same do not affect the reduction of luminance even when the light diffusing plate is used for the backlight surface light source and improves the antistatic property of the light diffusing plate. In addition, unlike the coating layer using an ionic or nonionic surfactant, it maintains excellent antistatic properties even after the washing process during the process, the production process is simplified, and the production stability also has an excellent advantage.

According to one embodiment of the invention, the diffusion substrate layer; And it provides a light diffusion plate comprising a coating layer having an organic fluorine-based ammonium imide salt represented by the formula (1).

&Lt; Formula 1 >

(Wherein, R ¹ and R ² are each independently a fluorine sulfonyl group, and R ³ to R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group.)

The diffusion base layer is not limited as long as it is a resin showing excellent properties in light transmittance and light resistance as a transparent resin, and selected from acrylic resin, styrene-acrylic copolymer resin, styrene resin, styrene-acrylonitrile resin and polycarbonate resin. It is preferable that it is formed from 1 or more types.

The acrylic resin may be a methacrylic acid alkyl ester such as methyl methacrylate, ethyl methacrylate, butyl methacrylate or 2-ethylhexyl methacrylate; Alkyl acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate; Methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate and dicyclopentanyl methacrylate; Acrylic acid cycloalkyl esters such as cyclohexyl acrylate and 2-methylcyclohexyl acrylate; Methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate; It is preferable that it is any homopolymer selected from acrylic acid aryl esters, such as phenyl acrylate and benzyl acrylate, or these copolymers.

The styrene-acrylic copolymer resin is at least one selected from methacrylic acid alkyl ester, acrylic acid alkyl ester, methacrylic acid cycloalkyl ester, acrylic acid cycloalkyl ester, methacrylic acid aryl ester, acrylic acid aryl ester, styrene, α-methyl styrene and at least one copolymer selected from m-methylstyrene, p-methylstyrene and p-methoxystyrene.

The styrene resin is preferably a homopolymer or a copolymer thereof selected from styrene, α-methyl styrene, m-methyl styrene, p-methyl styrene, and p-methoxy styrene.

The styrene-acrylonitrile-based copolymer resin is preferably a copolymer of acrylonitrile monomer with at least one selected from styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, and p-methoxystyrene.

The polycarbonate resin is composed of linear and branched aromatic polycarbonate homopolymers, polyester copolymers or mixtures of one or more thereof prepared by reacting dihydroxy phenol with phosgene or by reaction of dihydroxy phenol with a carbonate precursor. Group is preferred.

The thickness of the diffusion base layer is preferably 0.1 to 4 mm. When the thickness of the diffusion base layer is within the above range, the necessary rigidity is obtained as the diffusion plate, and light is partially absorbed in the diffusion base layer, thereby allowing the transmittance to be adjusted.

The diffusion substrate layer may include a diffusion agent. As the diffusion agent, any material used in the field of the present invention may be used, and organic and / or inorganic diffusion agents may be used alone or in combination. For example, silicon-based, acrylic-based, styrene-based, methyl methacrylate-styrene copolymer-based, polycarbonate-based, olefin-based crosslinked or uncrosslinked fine particles, silica, talc, calcium carbonate, barium sulfate, titanium dioxide (TiO ₂ ), etc. may be used. Can be.

The size of the diffusing agent is preferably 0.1 to 50㎛ that can increase the light diffusion effect. In this case, the size means a size with respect to the diameter.

The content of the diffusion agent is 0.01 to 40 parts by weight, preferably 0.1 to 10 parts by weight based on 100 parts by weight of the transparent resin. When the content of the diffusing agent is less than 0.01 part by weight, the incident light cannot be diffused, and when the content of the diffusing agent is more than 40 parts by weight, the transmittance of the light is decreased and the dispersibility of the diffusing agent is deteriorated, thereby not being able to exhibit high brightness.

The coating layer is to include an organic fluorine-based ammonium imide salt represented by the following formula (1).

&Lt; Formula 1 >

In the above formula, R ¹ and R ² are each independently a fluorine sulfonyl group, and R ³ to R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group. These may be the same or different. As said aryl group, a phenyl group or a naphthyl group is preferable.

The organic fluorine-based ammonium salt of ammonium salt represented by the formula (1) is an antistatic agent, and the organic fluorine-based ammonium salt of the ammonium salt represented by the formula (1) remains on the surface even after water washing due to the action of the hydrophobic (Hydrophobic) property of the fluorine group. A sustained effect can be obtained.

The organic fluorine-based ammonium salt of ammonium salt represented by Formula 1 may be a fluorine-based sulfonyl ammonium salt of ammonium salt represented by Formula 2.

<Formula 2>

Specific examples of the organic fluoride imide acid ammonium salt represented by Formula 1 include tri-butylmethylammonium bis-trifluoromethanesulfonyl imide, tri-butylphenylammonium bis-trifluoromethanesulfonyl imide, and tri-pentyl Methyl ammonium bis-trifluoromethanesulfonyl imide etc. are mentioned.

The coating layer has a thickness of 0.001 to 10㎛, preferably 0.01 to 1㎛, more preferably 0.05 to 0.5㎛. When the thickness of the coating layer is in the above range to prevent the antistatic performance is lowered, there is no problem that the antistatic performance is saturated and has an economic effect.

The coating layer may further include at least one functional additive such as an ultraviolet absorber, an antioxidant, a heat stabilizer, a fluorescent brightener, etc. in that it may add additional functionality as well as antistatic performance.

When the coating layer includes an ultraviolet absorber as an additive, it is preferable that the weight ratio of the organic fluorine-based ammonium imide acid salt represented by Formula 1 to the ultraviolet absorber is 1: 2 to 10. When the weight ratio is within the above range, the yellowing phenomenon is reduced by sufficient ultraviolet protective effect, and there is an advantage of preventing the contamination by foreign matter by exhibiting an antistatic function.

When the coating layer includes an antioxidant as an additive, it is preferable that the weight ratio of the organic fluorine-based ammonium imide acid salt represented by Formula 1 to the antioxidant is 1: 1 to 10. When the weight ratio is within the above range, discoloration resistance of the transparent resin and the diffusing agent may be obtained by heat due to the backlight, and the antistatic function may be exhibited to prevent contamination by foreign matter.

When the coating layer includes an ultraviolet absorber and an antioxidant as an additive, the coating layer preferably has a weight ratio of 1: 2 to 10: 1 to 10 of an organic fluorine-based ammonium imide salt represented by Formula 1 to an ultraviolet absorber to an antioxidant. All.

When the weight ratio of the organic fluorine-based ammonium salt of ammonium salt represented by Chemical Formula 1 is within the above range, it is possible to obtain an effect of maintaining excellent antistatic property even after water washing of the light diffusion plate.

In addition, when the weight ratio of the ultraviolet absorbent is within the above range, when the backlight is irradiated for a long time by the ultraviolet protective effect can be obtained the effect of preventing the yellowing phenomenon.

Moreover, when the weight ratio of the said antioxidant is in the said range, the effect which can prevent coloring or physical property fall by the heat | fever, oxidation, etc. which generate | occur | produce at the time of shaping | molding, does not fall.

In addition, apart from the coating layer, a functional layer including the functional additive may be added between the diffusion substrate layer and the coating layer. In particular, the functional layer may include an ultraviolet absorber or an antioxidant.

As said ultraviolet absorber, a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a formamidine ultraviolet absorber, etc. are mentioned.

Examples of the benzophenol ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 2-hydroxy-4-benzyl Oxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and the like.

Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, and 2- (2-hydroxy -3,5-dicumylphenyl) phenylbenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2-hydroxy-3,5-di-tert-butylphenyl) benzo Triazole, 2- (2-hydroxy-3,5-di-tert-butylphenyl) -5-chlorobenzotriazole, and the like.

As the formamidine-based ultraviolet absorber, N- (4-ethoxycarbonylphenyl) -N-methyl-N-phenylformamidine, N, N-bis (4-ethoxycarbonylphenyl) -N-benzylform Amidine, N-3,5-di-tert-butyl-4-hydroxybenzyl-N'-4-ethoxycarbonylphenyl-N-phenylformamidine, N, N-bis (4-ethoxycarbo Nylphenyl) -N-3,5-di-tert-butyl-4-hydroxybenzylformamidine, N-4-butoxycarbonylphenyl-N'-4-ethoxycarbonylphenyl-N-3, 5-di-tert-butyl-4-hydroxybenzylformamidine etc. are mentioned.

As said ultraviolet absorber, 1 or more types of ultraviolet absorbers chosen from the group which consists of a benzophenone series, a benzotriazole series, and a formamidine type ultraviolet absorber are preferable.

The antioxidants include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants and the like. Among them, phenolic antioxidants and phosphorus antioxidants are preferred, and most preferred are phenolic antioxidants, which are transparent, heat resistant, and the like. There is an advantage that the coloring or physical properties of the molded body due to heat or oxidative deterioration generated during coating are not lowered without lowering.

Examples of the phenolic antioxidant include n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate and n-octadecyl3- (3,5-di-t- Butyl-4-hydroxyphenyl) -acetate, n-octadecyl 3,5-di-t-butyl-4-hydroxybenzoate, n-hexyl 3,5-di-t-butyl-4-hydroxyphenyl Benzoate, n-dodecyl 3,5-di-t-butyl-4-hydroxyphenylbenzoate, neo-dodecyl3- (3,5-di-t-butyl-4-hydroxyphenyl) prop Cypionate, dodecyl β (3,5-di-t-butyl-4-hydroxyphenyl) propionate, and the like.

Examples of the phosphorus antioxidant include trisnonylphenyl phosphite, triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, and the like.

Examples of the sulfur-based antioxidant include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, Pentaerythritol tetrakis (3-lauryl thio propionate) etc. are mentioned. It is preferable to use at least 1 or more of these.

The light diffusion plate having a coating layer containing an organic fluorine-based ammonium imide salt represented by Chemical Formula 1 according to the present invention has excellent surface resistance of 10 ¹¹ Ω / sq or less, preferably 10 ⁹ to 10 ¹⁰ Ω / sq. It is preferable at the point for obtaining antistatic performance.

In particular, the light diffusion plate according to the invention when subjected to 10 seconds during the washing process by spraying at a pressure of 0.1MPa at a temperature of 25 ℃ be washed before and after the change in surface resistance values with 10 ¹ Ω / sq or less It is preferable that the lower the surface resistance change value is, the better the lower limit value is meaningless.

In general, the diffusion plate using an external coating type antistatic agent has to go through a water washing process to remove dust or foreign matter. At this time, since the antistatic agent is removed due to water washing, the antistatic performance of the diffusion plate after water washing is significantly reduced. do.

In the present invention, it is possible to maintain an excellent antistatic performance even after washing, while preventing the problem that the antistatic agent is removed even after the washing process, including the organic fluorine-based ammonium ammonium salt represented by the formula (1).

According to another embodiment of the present invention, a light including a step of forming a coating layer using a spray coating method on a surface of the diffusion substrate layer of the organic fluoride-based ammonium imide salt represented by the following formula (1) and an organic solvent It is to provide a method for producing a diffusion plate. In this case, the diffusion substrate layer is the same as described above.

&Lt; Formula 1 >

In the above formula, R ¹ and R ² are each independently a fluorine sulfonyl group, and R ³ to R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group. These may be the same or different. As said aryl group, a phenyl group or a naphthyl group is preferable.

The diffusion substrate layer is the same as described above.

The coating solution includes an organic fluorine-based ammonium imide salt represented by Chemical Formula 1 and an organic solvent.

The organic fluorine-based ammonium ammonium salt represented by the formula (1) is the same as described above.

The content of the organic fluorine-based ammonium ammonium salt represented by Formula 1 is preferably 0.01 to 50% by weight, preferably 0.1 to 25% by weight, more preferably 1 to 10% by weight in the coating solution.

When the content of the organic fluorine-based ammonium salt of the ammonium salt represented by Formula 1 is less than 0.01% by weight, the surface of the light diffusion plate is contaminated by dust and foreign substances because it does not exhibit an antistatic function, and when it exceeds 50% by weight, light diffusion Stain is formed on the surface of the plate to interfere with the transmission of light, there is a problem in reducing the brightness.

Alcohols are preferable as the organic solvent, and specific examples thereof include methanol, ethanol, propanol, isopropyl alcohol, and the like.

The content of the organic solvent is preferably 50 to 99.99% by weight in the coating liquid.

When the content of the organic solvent is within the above range, there is an advantage that the drying time is shortened or a drying process is not necessary.

The coating solution including the organic fluorine-based ammonium imide salt represented by Chemical Formula 1 and an organic solvent may be applied to one surface of the diffusion substrate layer to form a coating layer. The coating process may be a coating method.

The coating method may include a knife coating method, a comma coating method, a roll coating method, a gravure coating method, a micro gravure coating method, a dip coating method, a spray coating method, a slot die coating method, and any one of these methods. Can be used arbitrarily selected. In particular, it is preferable to use a spray coating method in that the process is simplified. That is, when the coating layer is formed by the spray coating method, since the temperature of the surface of the diffusion plate is high during the process, when the coating liquid is sprayed on the diffusion plate, the coating liquid is dried immediately, and thus a drying process is not required separately, thereby simplifying the process.

In addition, the general internally added antistatic agent has a problem in that the production stability is lowered, such as warping the surface of the diffusion plate, but the coating liquid according to the present invention can be applied to the spray coating method, resulting in less foreign material defects and other defects, resulting in low production stability. It can have the effect of improving.

The coating layer is formed by such a manufacturing method, and the thickness of the formed coating layer is 0.001 to 10 μm, preferably 0.01 to 1 μm, and more preferably 0.05 to 0.5 μm as described above. Through this, it has the advantage of maintaining excellent antistatic property even after the water washing process for removing dust or foreign matter while maintaining high brightness.

In the present invention, the above-described ultraviolet absorber, antioxidant, or both thereof may be added to the coating solution.

When the ultraviolet absorber is added to the coating liquid, the content of the ultraviolet absorber is 2 to 10 parts by weight, preferably 2 to 6 parts by weight, and more preferably 2 to 5 parts by weight based on 1 part by weight of the antistatic agent. When the content of the ultraviolet absorber is less than 2 parts by weight, the surface layer of the light diffusion plate is coated with the ultraviolet absorber is small enough that the UV protective effect is not sufficient, yellowing phenomenon occurs when the backlight is irradiated for a long time, exceeds 10 parts by weight Since the ultraviolet absorbent does not penetrate the surface irregularities of the light diffusion plate, there is a tack, which may cause a problem in assembling the backlight unit, and also hinder the transmission of light, thereby reducing the luminance.

When the antioxidant is added to the coating solution, the content of the antioxidant is 1 to 10 parts by weight, preferably 1 to 5 parts by weight, and more preferably 1 to 3 parts by weight based on 1 part by weight of the antistatic agent. When the amount of the antioxidant is less than 1 part by weight, the heat dissipation resistance of the transparent resin and the diffusion agent is not obtained by heat due to the backlight for a long time, and when the amount exceeds 10 parts by weight, a stain is formed on the surface of the light diffusion plate to provide light. There is a problem of reducing luminance by disturbing transmission and causing alteration.

When the ultraviolet absorber and the antioxidant are added to the coating solution, their content may include 2 to 10 parts by weight of the ultraviolet absorber and 1 to 10 parts by weight of the antioxidant based on 1 part by weight of the antistatic agent. When the ultraviolet absorber and the antioxidant are added in the above range, the effect according to the ultraviolet absorber and the antioxidant can be obtained as described above.

In the present invention, by using the ultraviolet absorbent in the above-described content in the coating liquid, and using an organic solvent as a solvent, by coating it on one surface of the diffusion substrate layer, it is possible to solve the yellowing phenomenon by the ultraviolet light emitted from the backlight.

According to another embodiment of the present invention, to provide a backlight device including the light diffusion plate described above.

The light diffusion plate manufactured according to the present invention can be preferably applied to a backlight device. The backlight device is not particularly limited, and any backlight device well known in the art may be applied. The light source of the backlight device may be used without limitation, such as a hot cathode tube, a cold cathode tube, a light emitting diode (LED), an organic electroluminescent element (OLED), and the like.

According to another embodiment of the present invention, there is provided a liquid crystal display device having a backlight device having the light diffusion plate described above. The backlight device is preferably applied to liquid crystal display devices of various driving methods such as reflective, transmissive and transflective liquid crystal display (LCD) or TN type, STN type, OCB type, HAN type, VA type and IPS type. Can be.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. However, the following embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

Example  One

100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 µm were uniformly mixed and extruded (tri-n-butylmethyl A coating liquid consisting of 1% by weight of ammonium bis-trifluoromethanesulfonyl imide) and 99% by weight of alcohol was applied by spray coating, followed by drying to prepare a diffusion plate having a 200 nm thick coating layer.

Example  2

Antistatic agent (tri-n-butylmethylammonium) was applied to a 1.5 mm thick diffusion substrate layer which was homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 µm. A coating liquid consisting of 10 wt% of bis-trifluoromethanesulfonyl imide) and 90 wt% of alcohol was applied by spray coating, followed by drying to prepare a diffusion plate having a 200 nm thick coating layer.

Example  3

An antistatic agent (tri-pentylmethylammonium bis-) was applied to a 1.5 mm thick diffusion substrate layer homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. A coating liquid consisting of 30% by weight of trifluoromethanesulfonyl imide) and 70% by weight of alcohol was applied by spray coating, followed by drying to prepare a diffusion plate having a coating layer having a thickness of 200 nm.

Example  4

An antistatic agent (tri-pentylmethylammonium bis-) was applied to a 1.5 mm thick diffusion substrate layer homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. A coating liquid consisting of 50 wt% of trifluoromethanesulfonyl imide) and 50 wt% of alcohol was applied by spray coating, followed by drying to prepare a diffusion plate having a 200 nm thick coating layer.

Example  5

Antistatic agent (tri-n-butylmethylammonium) was applied to a 1.5 mm thick diffusion substrate layer which was homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. A coating liquid consisting of 1% by weight of bis-trifluoromethanesulfonyl imide), 5% by weight of a UV absorber (ZIKASORB-WR, Zico), and 94% by weight of alcohol was applied by spray coating, followed by drying to obtain a thickness of 200 nm. A diffuser plate with a coating layer was prepared.

Example 6

Antistatic agent (tri-n-butylmethylammonium) was applied to a 1.5 mm thick diffusion substrate layer which was homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. Spray coating solution consisting of 1% by weight of bis-trifluoromethanesulfonyl imide), 5% by weight of ultraviolet absorber (ZIKASORB-WR, Zico), 1% by weight of antioxidant (ZIKANOX-549, Zico) and 94% by weight of alcohol After coating by the coating method and dried to prepare a diffuser plate with a coating layer of 200nm thickness.

Example  7

Antistatic agent (tri-n-butylmethylammonium) was applied to a 1.5 mm thick diffusion substrate layer which was homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 µm. A coating liquid consisting of 1% by weight of bis-trifluoromethanesulfonyl imide), 5% by weight of a UV absorber (ZIKASORB-WR, Zico), and 94% by weight of alcohol was applied by spray coating, followed by drying, A diffuser plate with a coating layer was prepared.

Example  8

Antistatic agent (tri-n-butylmethylammonium) was applied to a 1.5 mm thick diffusion substrate layer which was homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 µm. Spray coating solution consisting of 1% by weight of bis-trifluoromethanesulfonyl imide), 10% by weight of ultraviolet absorber (ZIKASORB-WR, Zico), 5% by weight of antioxidant (ZIKANOX-549, Zico) and 84% by weight of alcohol After coating by the coating method and dried to prepare a diffuser plate with a coating layer of 200nm thickness.

Example  9

100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 µm were uniformly mixed and extruded (tri-n-butylmethyl A coating solution consisting of 10% by weight of ammonium bis-trifluoromethanesulfonyl imide), 5% by weight of ultraviolet absorber (ZIKASORB-WR, Zico), 1% by weight of antioxidant (ZIKANOX-549, Zico) and 84% by weight of alcohol After coating by spray coating method and dried to prepare a diffuser plate with a coating layer of 200nm thickness.

Comparative example  One

Antistatic agent (quaternary ammonium esosulfate) on a 1.5 mm thick diffusion substrate layer homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. A coating liquid consisting of 1% by weight and 99% by weight of alcohol was applied by spray coating, followed by drying to prepare a diffuser plate having a coating layer having a thickness of 200 nm.

Comparative example  2

Antistatic agent (quaternary ammonium esosulfate) on a 1.5 mm thick diffusion substrate layer homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. A coating liquid consisting of 1 part by weight, a UV absorber (ZIKASORB-WR, Zico) 5% by weight, and 94% by weight of alcohol was applied by spray coating, followed by drying to prepare a diffusion plate having a 200 nm thick coating layer.

Comparative example  3

Antistatic agent (tri-n-butylmethylammonium) was applied to a 1.5 mm thick diffusion substrate layer which was homogeneously mixed and extruded by mixing 100 parts by weight of polystyrene resin (G9001, PS Japan) and 1 part by weight of silicon particles having a refractive index of 1.42 and a size of 2 μm. Bis-trifluoromethanesulfonyl imide) was applied to the coating liquid consisting of 60% by weight, and 40% by weight of alcohol by spray coating, followed by drying to prepare a diffuser plate having a 15 μm thick coating layer.

The diffusion plates prepared according to Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated according to the following method, and the results are shown in Table 1 below.

(1) haze (%)

The three diffusers were processed at 60 × 60 mm each, stored at constant temperature and humidity (25 ° C., 50% Rh) for 24 hours, and then measured using a haze meter (NDH-2000, Nippon Denshoku). Indicated.

(2) Total light transmittance (%)

The three diffusers were processed at 60 × 60 mm each, stored at constant temperature and humidity (25 ° C., 50% Rh) for 24 hours, and then measured using a haze meter (NDH-2000, Nippon Denshoku) to show average values. It was.

(3) surface condition

The prepared diffusion plate was processed at 100 × 100 mm and stored at constant temperature and humidity (25 ° C, 50% Rh) for 24 hours, and then observed the surface state using a polarizing microscope (Olympus) and a 3-D microscope (nano system). It was. At this time, if more than one spot affects the transmittance and luminance, it is evaluated as NG.

(4) yellowing (ㅿ YI)

After storing the prepared diffusion plate in a constant temperature and humidity (25 ℃, 50% Rh) for 24 hours, and using the aging tester (Shinsung Co., Ltd.) using Xenon lamp for 50 ℃, 500 hours, UV-Visible The change of Yellowness Index was measured using a spectrometer (Cary-100, Varian). At this time, if the yellowness index change value is less than Δ5, it is determined that there is no change in transmittance and luminance over time.

(5) Surface resistance value (Ω / sq)

After processing the prepared diffusion plate to 100 × 100㎜ and using a surface resistance measuring instrument (mCP-HT450, Japan Mitsubishi Chemical Co., Ltd.) to measure the five different points to calculate the average value. In the measurement, the voltage was fixed at 500V and measured at the value 30 seconds after the start. In addition, the surface resistance value after performing the water washing process in a spray method for 10 seconds at a pressure of 0.1 MPa at a temperature of 25 ℃ was also measured in the same manner.

division Coating layer
thickness Haze (%) Electric power
Transmittance (%) surface
condition ΔYI
(500hrs) Surface resistance
(Ω / sq) After washing
Surface resistance
(Ω / sq) Example 1 200 nm 99.5 64.5 OK 7.32 10 or less ¹⁰ 10 or less ¹⁰ Example 2 200 nm 99.5 64.3 OK 7.12 Less than 10 ⁹ Less than 10 ⁹ Example 3 200 nm 99.4 64.6 OK 7.23 Less than 10 ⁹ Less than 10 ⁹ Example 4 200 nm 99.5 64.5 OK 7.15 Less than 10 ⁹ 10 ⁸ or less Example 5 200 nm 99.4 64.4 OK 4.23 10 or less ¹⁰ 10 or less ¹⁰ Example 6 200 nm 99.4 64.5 OK 3.75 10 or less ¹⁰ 10 or less ¹⁰ Example 7 5㎛ 99.5 64.1 OK 4.12 10 or less ¹⁰ 10 or less ¹⁰ Example 8 200 nm 99.5 64.6 OK 3.51 10 ¹² or less 10 ¹² or less Example 9 200 nm 99.5 63.6 NG 3.71 10 or less ¹⁰ 10 or less ¹⁰ Comparative Example 1 200 nm 99.5 64.3 OK 7.56 Less than 10 ⁹ 10 over ¹³ Comparative Example 2 200 nm 99.5 64.5 OK 4.33 Less than 10 ⁹ 10 over ¹³ Comparative Example 3 15 탆 99.4 63.5 NG 7.87 Less than 10 ⁹ Less than 10 ⁹

As shown in Table 1, in Examples 1 to 4, it was found that even after increasing the content of the antistatic agent, excellent surface resistance was maintained even after washing with water while maintaining excellent haze and transmittance. In addition, Examples 5 to 6 maintains excellent surface resistance after washing with water without affecting antistatic and other physical properties even though it contains both an ultraviolet absorber, an ultraviolet absorber, and an antioxidant, and the yellowing degree is reduced due to the small ΔYI due to the ultraviolet absorber. It became small and it turned out that (DELTA) YI becomes lower by antioxidant.

In addition, in Example 7, it was found that even after increasing the thickness of the coating layer, the surface resistance was maintained after washing with water without affecting the haze or transmittance.

On the other hand, Comparative Examples 1 and 2 showed that the surface resistance was significantly increased after washing with water irrespective of the ultraviolet absorbent when using a general ionic antistatic agent, and Comparative Example 3 was found to have a problem that a fine stain occurs on the surface.

From this, it can be seen that the use of an antistatic agent of an organic fluorine-based ammonium imide salt maintains excellent antistatic properties even after washing with water, and yellowing phenomenon is reduced by adding an ultraviolet absorber, an antioxidant, or both.

All simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (11)

A diffusion base layer; And As a light diffusion plate comprising a coating layer having an organic fluorine-based ammonium salt of ammonium salt represented by the following formula (1), &Lt; Formula 1 >

(Wherein R ¹ and R ² are each independently a fluorine sulfonyl group, R ³ to R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group.) The light diffusion plate has a surface resistance change value of 10 ¹ Ω / sq or less before and after washing when the washing process is performed by spraying for 10 seconds at a pressure of 0.1 MPa at a temperature of 25 ° C. The coating layer is a light diffusion plate having a weight ratio of the organic fluorine-based ammonium imide acid salt represented by the formula (1) to the ultraviolet absorber to the antioxidant is 1: 2 to 10: 1 to 10. The light diffusion plate of claim 1, wherein the coating layer has a thickness of 0.001 to 10 μm. delete delete The light diffusion plate according to claim 1, wherein the organic fluoride imide acid ammonium salt represented by the formula (1) is a fluorine sulfonyl ammonium salt represented by the following formula (2). <Formula 2>

Comprising the step of forming a coating layer using a spray coating method coating liquid containing an organic fluorine-based ammonium imide salt and an organic solvent represented by the following formula (1) on one surface of the diffusion substrate layer, &Lt; Formula 1 >

(Wherein R ¹ and R ² are each independently a fluorine sulfonyl group, R ³ to R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group. They may be the same or different.) The coating solution is a method for producing a light diffusion plate comprising 2 to 10 parts by weight of a ultraviolet absorber and 1 to 10 parts by weight of an antioxidant based on 1 part by weight of the organic fluorine-based ammonium imide salt represented by Chemical Formula 1. The method of claim 6, wherein the coating solution comprises 0.01 to 50% by weight of an organic fluorine-based ammonium imide acid salt represented by Formula 1 and 50 to 99.99% by weight of an organic solvent. delete The method of manufacturing a light diffusion plate according to claim 6, wherein the organic fluorine-imide ammonium salt represented by Chemical Formula 1 is a fluorine sulfonyl ammonium salt represented by the following Chemical Formula 2. <Formula 2>

Section 1. A backlight device comprising the light diffusing plate according to any one of claims 2 and 5. A liquid crystal display comprising the backlight device of claim 10.