KR20080101584A - Uv-curable resin composition, prism sheet, and backlight device for lcd - Google Patents

Abstract

A UV curable resin composition is provided to ensure excellent releasing ability and high transparency and to satisfy the strength of a sheet, spots suppression and high refractive index for improving brightness. A UV curable resin composition comprises (A) a silicon urethane acrylate of the chemical formula 1; (B) an (meth) acrylate oligomer of high refractivity more than 1.50; (C) monofunctional (meth) acrylate for lowering viscosity; and (D) a photoinitiator. In the chemical formula 1, a and b are an integer of 1-10; n is an integer of 1-20; R1 comprises, independently, hydrogen or hetero atom as a C1-10 alkyl group according to the location; R2 comprises a hetero atom as a C1-20 aliphatic or aromatic hydrocarbon according to the location; and Y comprises 1~10 (meth) acrylate reacting in UV curing or a hetero atom as a C0-30 aliphatic or aromatic hydrocarbon.

Description

UV curable resin composition, prism sheet manufactured using the same, and backlight device for liquid crystal display having the same {UV-Curable Resin Composition, Prism Sheet, And Backlight Device For LCD}

The present invention relates to an ultraviolet curable resin composition, a prism sheet manufactured using the same, and a backlight device for a liquid crystal display device having the same.

UV-curable imprint lithography resins have many applications, such as organic cell materials replacing conventional photoresists or resins for brightness enhancement films, which are materials of backlight units in TFT-LCDs. However, in order to impart releasability with a metal mold, a polydimethyl siloxane mold, a polymer mold, and the like, most of the known techniques are used to impart functionality using a silicone-based or fluoro-based release agent. However, most of them are materials that operate in a high temperature environment, and when used for a long time, a release agent rises to the surface, thereby degrading the transparency of the coated surface (hereinafter referred to as high temperature stain). In addition, the optical film has a problem that some release agents appear on the surface as a stain due to contact with human hands or gloves during transport or mounting the device during operation.

In order to solve this problem, products that try to solve the problems mentioned by reacting during photocuring by introducing some acrylic functional groups into silicon or fluoro compounds such as the following Structural Formula 1 are commercially available, but have a small amount of acrylic compared to molecular weight, When the amount is used, there is a problem in that the transparency of the coating liquid is deteriorated. Most of the materials, such as the following Structural Formula 1, are used in an amount of 0.5 parts by weight or less and have a poor release property.

[Formula 1]

 In order to solve the above problems, the present inventors maintain the performance of a prism sheet molded in a UV curable resin composition, particularly a polymer mold, a metal mold, a polydimethyl siloxane mold, etc. It was an object of the present invention to provide a resin composition and the like in which transparency is maintained at the time of the combination of the resin composition without imparting a release agent on the surface or at the high temperature while imparting.

 The present invention for achieving the above object,

A silicone urethane acrylate (A) represented by the following formula (1), a (meth) acrylate oligomer (B) having a high refractive index of 1.50 or more, a monofunctional (meth) acrylate (C) for lowering the viscosity, and a photoinitiator (D) It provides an ultraviolet curable resin composition comprising a.

[Formula 1]

(Wherein a and b are integers of 1 to 10, n is an integer of 1 to 20, R 1 is independently hydrogen or an alkyl group having 1 to 10 carbon atoms depending on the position, and may include a hetero atom, and R 2 Is independently an aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, depending on the position, and may include a hetero atom, and Y is 0 to 30 ((meth) containing 1 to 10 (meth) acrylate groups reacted upon UV curing. (A number excluding the carbon number of the acrylate group) may include a hetero atom as an aliphatic or aromatic hydrocarbon.)

In addition, the silicone urethane acrylate (A) provides an ultraviolet curable resin composition comprising 5 to 40 parts by weight in 100 parts by weight of the composition.

In addition, the high refractive index (meth) acrylate oligomer (B) is a compound represented by the following formula (2), it provides an ultraviolet curable resin composition comprising 20 to 50 parts by weight based on 100 parts by weight of the composition.

[Formula 2]

, R₁, R₂는 각각 독립적으로 수소 원자, 또는 탄소수 1~10의 알킬기이며, X는 수소원자, 또는 할라이드 원자이며, Z는 수소원자, 또는 메틸기를 나타낸다.)(Wherein n is an integer of 0 to 5, Y is ethylene oxide, isopropylene oxide, or

, R ₁ , R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a halide atom, and Z represents a hydrogen atom or a methyl group.)

Also, Monofunctional (meth) acrylate (C) for lowering the viscosity contains a benzene ring, and provides an ultraviolet curable resin composition characterized in that the viscosity is a low viscosity monofunctional (meth) acrylate having a viscosity of 300 cps or less.

In addition, the monofunctional (meth) acrylate (C) for lowering the viscosity is a compound represented by the following formula (3), the viscosity at 25 ^° C is 300 cps or less, the refractive index is 1.51 ~ 1.58, 20 to 60 at 100 parts by weight of the composition It provides an ultraviolet curable resin composition comprising a weight part.

 [Formula 3]

(In formula, n is an integer of 0-3, X represents a hydrogen atom, a halide atom, or C1-C10 aliphatic or aromatic hydrocarbon.)

In addition, as the photoinitiator (D), at least one selected from the group of benzene ethers, benzyl ketals, alpha hydroxy alkyl phenones, and amino alkyl phenones, and phosphine oxides is used to select two or more kinds of photoinitiators. It is characterized in that, it provides an ultraviolet curable resin composition comprising 0.5 to 5 parts by weight in 100 parts by weight of the composition.

In addition, the phosphine oxide-based photoinitiator provides an ultraviolet curable resin composition, characterized in that not more than 50% of the total content of the photoinitiator.

In addition, the silicone urethane acrylate (A) provides an ultraviolet curable resin composition, which acts as a release agent.

The present invention also provides a prism sheet having a prism shape formed by curing the ultraviolet curable resin composition.

The present invention also provides a backlight device for a liquid crystal display device having the prism sheet.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail. Since the following detailed description is for the description of the exemplary embodiments, the scope of the rights defined by the claims is not limited, even though there is a certain or limiting expression.

UV curable resin composition according to an embodiment of the present invention, the silicone urethane acrylate (A) represented by the following formula (1), (meth) acrylate oligomer (B) of high refractive index of 1.50 or more, monofunctional ( It provides the ultraviolet curable resin composition containing a meta) acrylate (C) and a photoinitiator (D). In addition, various additives and solvents may be included as necessary.

[Formula 1]

First, the silicone urethane acrylate (A) represented by the formula (1) that can work particularly well as a release agent will be described.

(In Formula 1, a and b are integers of 1 to 10, n is an integer of 1 to 20. R 1 may independently include a hydrogen atom as a hydrogen or an alkyl group having 1 to 10 carbon atoms, depending on the position. R 2 may be an aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms independently, depending on the position, and may include a hetero atom, preferably toluene, xylene, naphthalene, hexamethylene, isophorone, or the like. Y is an aliphatic or aromatic hydrocarbon having 0 to 30 carbon atoms (excluding carbon atoms of (meth) acrylate groups) containing 1 to 10 (meth) acrylate groups reacted upon UV curing. Can be.)

More specifically, Chemical Formula 1 may impart 1-10 acrylic functional groups to a urethane (meth) acrylate having a silicone structure, and preferably, 6 or more acrylic functional groups may be more free from high temperature stains. In addition, the result is a significant reduction in the ridges. It is preferable to use polydimethyl siloxane in which the end of the silicon precursor is substituted with a hydroxyl group, and a number average molecular weight of 500 to 10,000 is appropriate, preferably 1,000 to 5,000. If the number average molecular weight is less than 1,000, the releasability is inferior, and if the number average molecular weight is more than 5,000, compatibility with other materials may be poor, thereby reducing transparency. Reaction of polydimethyl siloxane with diisocyanate to prepare an isocyanate-terminated oligomer, wherein commercially available isocyanates are toluene diisocyanate, xylene diisocyanate, methylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrozinnate methylene di Commercially available diisocyanates such as isocyanate, naphthalene diisocyanate and tetramethyl xylene diisocyanate may be used, and the molar ratio of polydimethyl siloxane and diisocyanate may use 0.01 to 0.9 moles of polydimethyl hydroxy hydroxide per 1 mole of diisocyanate. Preferably, 0.03-0.5 mol More preferably, 0.05-0.3 mol may be used. If the number of moles of dimethyl hydroxide is less than 0.05, the releasing property is reduced, and if it is at least 0.3 mole, the viscosity is increased and transparency is lowered. In order to give photocuring property to the oligomer synthesize | combined by the isocyanate terminal, the trifunctional or more than trifunctional acrylate monomer containing a hydroxyl group is made to react. If the acrylic functional group is less than trifunctional, it is difficult to guarantee transparency after the high temperature test. As the trifunctional or higher functional acrylate monomer containing a hydroxyl group, commercially available monomers such as pentyristinol triacrylate and dipentaerystyrol pentaacrylate can be used.

The silicone urethane acrylate (A) is preferably used 5 to 40 parts by weight based on 100 parts by weight of the total composition. The release effect is less than the following range, there is a problem that the physical properties may deteriorate, such as difficult to match the refractive index above the above range.

On the other hand, in order to use the composition as a prism sheet material, the refractive index must be above a certain level. The inventors have invented the need for a separate high refractive index binder and a dilute acrylate monomer after each effort.

It is not limited to high refractive index (meth) acrylate oligomers (B) to increase the refractive index, but tetrabromo bisphenol A (meth) acrylate, tetra bromo bisphenol A ethylene oxide (meth) acrylate, florene biphenol epoxy ( Meta) acrylate, florene biphenol ethylene oxide (meth) acrylate, and the like can be used. More preferably, a compound represented by the following formula (2) is used.

[Formula 2]

, R₁, R₂는 각각 독립적으로 수소 원자, 또는 탄소수 1~10의 알킬기이며, X는 수소원자, 또는 할라이드 원자이며, Z는 수소원자, 또는 메틸기를 나타낸다.)(Wherein n is an integer of 0 to 5, Y is ethylene oxide, isopropylene oxide, or

, R ₁ , R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a halide atom, and Z represents a hydrogen atom or a methyl group.)

It is preferable to use 20-50 weight part of the high refractive index (meth) acrylate oligomer (B) for improving a refractive index with respect to 100 weight part of total compositions. The refractive index may be a problem below the following range, and there is a problem that the self-resilience is reduced above the above range.

In addition, a dilution monomer for lowering the viscosity is required in terms of process conditions, and monofunctional (meth) acrylate (C) is preferable. In particular, the use of a low viscosity monofunctional (meth) acrylate having a benzene ring and having a viscosity of 300 cps or less may be able to match the viscosity while having a high refractive index.

For example, ethylene oxide is added to a phenolic material, or benzyl alcohol is an acrylic functional group imparted to an acrylic functional group, which is mostly monofunctional, has a low viscosity and a high refractive index. For example, 2-phenoxy ethanol (meth) acryl Monofunctional acrylate monomers such as late, benzyl (meth) acrylate, phenyl phenol ethanol (meth) acrylate, cumyl (meth) acrylate, naphthol ethanol (meth) acrylate, biphenyl methanol (meth) acrylate can be used It can be, the viscosity is 10 ~ 250 cps at 25 ^o C, the refractive index is characterized in that between 1.510 ~ 1.590.

In particular, the monofunctional (meth) acrylate (C) for lowering the viscosity is a compound represented by the following formula (3), and the viscosity at 25 ^° C. is preferably 300 cps or less and a refractive index of 1.51 to 1.58.

 [Formula 3]

(Wherein n is an integer of 0 to 3 and X represents a hydrogen atom, a halide atom, or an aliphatic or aromatic hydrocarbon having 1 to 10 carbon atoms. In particular, X is a hydrogen atom or an alkyl phenyl having a relatively high refractive index and viscosity). Has a low characteristic, and n is 0 to 3. Preferably, n is smaller than 1. If n is higher than the refractive index, the reaction is difficult and the viscosity is high. If n is larger than 3, the photocuring rate is lowered and the refractive index is Lowers.)

The material is a commercially available material, such as 2-phenoxy ethyl (meth) acrylate, ortho phenyl phenoxy ethyl (meth) acrylate, cumyl phenoxy ethyl (meth) acrylate, naphthol ethyl (meth) acrylate, etc. There is this.

Monofunctional (meth) acrylate (C) for lowering the viscosity is preferably used 20 to 60 parts by weight relative to 100 parts by weight of the composition. The viscosity may be high in the following range or less, and there is a problem in that the self-resilience decreases in the above range.

The resin composition may include a photoinitiator, for example, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinepropanone-1, diphenylketone benzyldimethyl ketal, 2-hydroxy- 2-methyl-1-phenyl-1-one, 4-hydroxy cyclophenyl, dimethoxy-2-phenylatetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4 -Knoloacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzophenone, 1-hydroxycyclohexyl phenyl ketone or the like can be used alone or in combination.

Preferably, it is preferable to use two or more photoinitiators by selecting one or more from the group of benzene ethers, benzyl ketals, alpha hydroxy alkyl phenones, amino alkyl phenones, and phosphine oxides. Photostimulants can be used with photoinitiators, for example triethylamine, diethylamine, methyldiethanolamine, ethanolamine, 4-dimenylamino-benzophosphoric acid, isoamyl-4-dimethylaminobenzoate, and the like. Can be used.

The photoinitiator is preferably used 0.1 to 10 parts by weight, in particular 0.5 to 5 parts by weight based on 100 parts by weight of the composition. Below the above range, the curing rate is slow, and above the above range, yellowing may be aggravated. In addition, the phosphine oxide-based photoinitiator is preferably not more than 50% of the total content of the photoinitiator.

Various additives may be included as necessary to improve other physical properties, and additives known in the art may be used without limitation. As for the addition amount of an additive, 0.1-5 weight part is common with respect to 100 weight part of compositions.

As a result of preparing the prism sheet after the photocuring coating composition was prepared by the organic combination of the specific components as described above and the photocuring process, the transparency of the resin was secured, the mold release property was excellent, and the weather resistance and the scratch resistance were improved. In addition, it was confirmed that there is no problem that stains occur while working with the backlight unit while ensuring transparency continuously after a high temperature test.

The present invention also provides a prism sheet having a prism shape formed by curing the photocurable coating composition. The configuration of the prism sheet is not limited and may employ a structure known in the art.

The manufacturing method is as follows. The photocurable coating composition may be coated on a transparent optical polymer substrate such as polyethylene terephthalate (hereinafter referred to as PET) or polycarbonate, or a film in which a water-dispersed polyurethane layer is coated on the substrate in a primer form of 1 to 2 μm. The thickness of a film is about 10-1,000 micrometers, Preferably 50-300 micrometers is used. Coating method can be applied to gravure coating, roll coating, life coating and the like.

Coating thickness is 1-200 micrometers normally, Preferably it is 10-100 micrometers, More preferably, it is 20-50 micrometers. UV light irradiation amount is about 0.1 ~ 2J / cm ^2, preferably 0.4 ~ 0.8J / cm ² and wavelength of it is better to use a metal halide lamp in the series to 365nm as the primary wavelength.

The highly refractive UV curable coating agent prepared as described above has excellent productivity due to the fast curing speed during manufacture, and the film produced after curing has no curling phenomenon, has little high brightness and shape breakage, and has no color change. And yellowing resistance and adhesion to the film was excellent, and the releasability with the polymer mold was good.

The present invention also provides a backlight device for a liquid crystal display device having the prism sheet. The backlight device is not limited and may employ a structure known in the art. For example, a light diffusion plate, a prism sheet, or the like may be provided on a light guide plate for guiding light of a light source and a light source such as an LED, and an upper surface of the light guide plate. It is preferable that the said prism sheet is a prism sheet mentioned above.

The present invention will be further illustrated by the following examples, which are only specific examples of the present invention, and are not intended to limit or limit the protection scope of the present invention.

Synthesis Example 1 Synthesis of Silicone-modified Urethane Acrylate

101.6 parts by weight of toluene diisocyanate (Dongyang Chemical Co., Ltd.), 145.8 parts by weight of temomer H-Si 2311 (Tegosa, hydroxyl value 40-50 mg KOH) / g, number average molecular weight 2,500), 0.5 parts by weight of dibutyl tin laurate was added and the reaction temperature was maintained at 75 degrees while stirring at room temperature and reacted for 3 hours. When the reaction was completed, the reaction temperature was cooled to room temperature, 750.2 parts by weight of Biscot # 300 (Osaka Yuki, Pentaerythritol triacrylate) and 2 parts by weight of methoxy hydroquinone were added thereto, and the reaction temperature was raised to 80 degrees. After completion of the reaction, the reaction was terminated when 2265 cm ^-1 , an isocyanate characteristic peak in the infrared spectrum, completely disappeared. The synthesized silicone-modified urethane acrylate had a refractive index of 1.495 and a viscosity of 34,000 cps at 25 ^° C.

Synthesis Example 2

YDB400 (Kukdo Chemical, Epoxy Equivalent 400 q / eq), the basic form of 681 parts by weight of tetrabromo bisphenol A epoxy resin, 116 parts by weight of acrylic acid (LG Chem.), 2.8 parts by weight of benzyl triethyl ammonium chloride, polymerization 0.2 parts by weight of methoxy hydroquinone as a inhibitor and 200 parts by weight of 2-phenoxy ethanol acrylate were added as a reactive diluent and reacted at 100 ° C for 10 hours. The reaction was terminated when the acid value was 2 mg KOH / g or less. The acid value of the reaction product was 1.8 mg KOH / g, the refractive index at 25 ^° C. was 1.584, and the viscosity was 180,000 cps.

EXAMPLE

Synthesis Example 1 and Synthesis Example 2 synthesized as described above were prepared in combination with the UV curable resin composition, and the UV curable resin composition according to Comparative Example was prepared in the same manner as in Table 1 by the same method. Physical properties of the prepared curable resin were evaluated according to the following evaluation method, and the results are shown in Table 2.

TABLE 1

A-L4: 2-phenyl phenoxy ethanol acrylate (NK)

M140: 2-phenoxy ethanol acrylate (Miwon Corporation)

I-184: 1-Hydroxy-cyclohexyl-phenyl ketone

I-819: Phosphine oxide, phenyl bis (2,4,6 trimethyl benzoyl)

Glide 440: polyether siloxane copolymer (TEGO Co., Ltd.)

Rad 2200: Silicone Polyether Acrylate (Tegosa, Chemical Formula 1)

The evaluation method is as follows.

(1) coating and release property evaluation

50 g of the uniformly mixed coating solution is sprayed onto a prismatic iron and nickel alloy plate (40x40cm), covered with a polyurethane film (SKC), and pressed with rubber roll to make a thickness of 40μm. The UV lamp was irradiated on the back of PET film so that the amount of light was 700mJ, and when separated from the alloy plate, the separation was good without the release sound.

(2) luminance evaluation

Cut the coated high brightness film to size in 17 inch panel backlight unit (LM170E01, Heesung Electronics) and fix it to fix prism film and measure the brightness of 13 spots using luminance meter (BM7, Topcon). The average value was calculated | required.

(3) liquid transparency

The transparency of the uniformly mixed coating solution was visually observed.

(4) mountain separation

  After mounting the coated film on the 17-inch backlight unit as shown in No. 2, the backlight unit is mounted on a device that reciprocates 60 times per minute and reciprocates for 10 hours. If it is very bad, if it is 7-9 places, if it is bad, if it is 4-6 places, if it is 1 ~ 3, it is good, if not, it is classified as good.

(5) adhesion

After eleven straight lines are drawn on the coated surface of the film at intervals of 1 mm each to make 100 squares, three peel tests are performed using a tape (CT-24, Nichi Nippon Co., Ltd.). Three 100 squares were tested and averaged.

The adhesion is recorded as follows.

Adhesion = n / 100

n: number of rectangles that do not peel out of the entire rectangle

100: total number of squares

Therefore, if none were peeled off, record 100/100.

(6) curl

The sample cut | disconnected to the square shape of A4 size (29.7X21.0cm) was put on the flat glass plate with the coated surface of the film facing up, and the distance from the square glass plate was measured, and the average value was made into the measured value.

Very good: 0 to 15 mm, good: 15 to 30 mm, poor: 30 to 50 mm, very poor: more than 50 mm.

(7) high temperature stain

Cut the prepared sheet into 4 × 4 cm size, cover the cover glass up and down, fix it with a clip, and leave it in an oven at 120 degrees to check for stains. The stains are marked as strong, medium, weak and none.

TABLE 2

The UV curable resin composition, particularly the resin composition of the present invention, which is excellent in releasability and has high transparency, can be applied to a prism sheet with excellent refractive index for improving luminance, which is an original object, It satisfies strength, mold release characteristics, and high temperature stain suppression.

Claims (10)

A silicone urethane acrylate (A) represented by the following formula (1), a (meth) acrylate oligomer (B) having a high refractive index of 1.50 or more, a monofunctional (meth) acrylate (C) for lowering the viscosity, and a photoinitiator (D) Ultraviolet curable resin composition comprising a. [Formula 1]

(Wherein a and b are integers of 1 to 10, n is an integer of 1 to 20, R 1 is independently hydrogen or an alkyl group having 1 to 10 carbon atoms depending on the position, and may include a hetero atom, and R 2 Is independently an aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, depending on the position, and may include a hetero atom, and Y is 0 to 30 ((meth) containing 1 to 10 (meth) acrylate groups reacted upon UV curing. (A number excluding the carbon number of the acrylate group) may include a hetero atom as an aliphatic or aromatic hydrocarbon.)  The method according to claim 1, wherein the silicone urethane acrylate (A) is 5 to 40 parts by weight, and the high refractive index (meth) acrylate oligomer (B) is 20 to 50 parts by weight based on 100 parts by weight of the composition. Monofunctional (meth) acrylate (C) for lowering UV curable resin composition, characterized in that 20 to 60 parts by weight, photoinitiator (D) comprises 0.5 to 5 parts by weight. The ultraviolet curable resin composition according to claim 1, wherein the high refractive index (meth) acrylate oligomer (B) is a compound represented by the following general formula (2). [Formula 2]

(Wherein n is an integer of 0 to 5, Y is ethylene oxide, isopropylene oxide, or

, R ₁ , R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a halide atom, and Z represents a hydrogen atom or a methyl group.) The ultraviolet curable resin composition according to claim 1, wherein the monofunctional (meth) acrylate (C) for lowering the viscosity contains a benzene ring and is a low viscosity monofunctional (meth) acrylate having a viscosity of 300 cps or less. . The monofunctional (meth) acrylate (C) for lowering the viscosity is a compound represented by the following Chemical Formula 3, wherein the viscosity at 25 ^° C. is 300 cps or less and the refractive index is 1.51 to 1.58. Curable resin composition.  [Formula 3]

(In formula, n is an integer of 0-3, X represents a hydrogen atom, a halide atom, or C1-C10 aliphatic or aromatic hydrocarbon.)  The photoinitiator (D) is selected from the group consisting of benzene ether, benzyl ketal, alpha hydroxy alkyl phenone, and amino alkyl phenone initiators, at least one selected from the group consisting of phosphine oxides and at least two kinds thereof. An ultraviolet ray curable resin composition characterized by using a photoinitiator. The ultraviolet curable resin composition according to claim 6, wherein the phosphine oxide-based photoinitiator does not exceed 50% of the total content of the photoinitiator. The ultraviolet curable resin composition according to claim 1, wherein the silicone urethane acrylate (A) acts as a release agent. The prism sheet provided with the prism shape formed by hardening | curing the ultraviolet curable resin composition of any one of Claims 1-8. The backlight device of the liquid crystal display device provided with the prism sheet of Claim 9.