KR101230235B1 - Ink composition for patterning at light guide plate for back light units and method for producing thereof - Google Patents

Abstract

PURPOSE: A diffusion ink composition for patterning a light guide plate of a back light unit is provided to improve luminance and ink printing ability by using a nano dispersion technology. CONSTITUTION: A diffusion ink composition for patterning a light guide plate of a back light unit comprises 40-55 weight% of solvent, 10-15 weight% of inorganic nanoparticles(22), 10-20 weight% of polymethylmethacrylate beads, 20-30 weight% of acrylic copolymer(21) containing methylmethacrylate, 1-15 weight% of additive based on the total weight of the diffusion ink composition. The inorganic nanoparticles are manufactured by a liquid-chemistry method, and have an average particle diameter of 0.1-10 microns. The additive is one or more selected from a diluent, a dispersant, a silicon antifoaming agent, and a leveling agent.

Description

Diffusion ink composition for light guide plate pattern formation of backlight unit and its manufacturing method {Ink composition for patterning at Light Guide Plate for Back Light units and method for producing

The present invention relates to a diffusion ink composition for forming a light guide plate pattern of a backlight unit and a method of manufacturing the same. More specifically, the present invention relates to an ink composition for forming a pattern on a LGP for a thin-film LED LCD. As a starting material, the present invention relates to a diffusion ink composition for forming a light guide plate pattern of a backlight unit having a luminance and printability to which nanodispersion mixing technology is applied, and particularly free of environmental hazards by a halogen component, and a method of manufacturing the same.

A display device that displays an image is classified into a display device that emits itself and a display device that cannot emit itself. The display device that cannot emit light by itself includes a liquid crystal display device using liquid crystal, and the liquid crystal display device includes a light emitting unit that generates and provides light. The liquid crystal display device has advantages in miniaturization and light weight, and its demand is increasing, and accordingly, the importance of the light emitting unit for providing light for displaying an image is increasing.

The light emitting unit is required to have sufficient brightness of the provided light and that the brightness is uniform for the entire screen on which an image is displayed. In order to satisfy the above requirements, a pattern using predetermined ink is formed in the light emitting unit. Although the above requirement is satisfied to some extent through the pattern using the ink, there is a difference in the luminance depending on the material of the ink.

Conventional light guide plate inks containing halogen have many problems to be used as ink for pattern formation in LGP for thin-film LED LCD due to problems of environmental hazards, lowered ink printability, and reduced luminance.

The present invention has been made to improve the above-mentioned conventional problems, by synthesizing various types of inorganic nano-particle powder by varying the starting material and the pH control agent for forming the light guide plate pattern of the backlight unit such as LGP for thin LED LCD Provided is a diffusion ink composition for forming a light guide plate pattern of a backlight unit that does not contain a halogen material and improves brightness and printability by using as a starting material for producing a diffusion ink and using nanodispersion mixing technology. It is a problem.

Diffusion ink composition for light guide plate pattern formation of the backlight unit of the present invention, which solved the above problems, 40 to 55% by weight solvent, 10 to 15% by weight inorganic nanoparticle powder, polymethyl methacrylate (based on the total weight of the diffusion ink composition) Polymethylmethacrylate (PMMA) Beads (Bead) 10 to 20% by weight, methyl methacrylate (Methylmethacrylate) comprising an acrylic copolymer containing 20 to 30% by weight and additives 1 to 15% by weight.

Here, the solvent is selected from the group consisting of dimethyl adipate, diethylene glycol monoethyl ether acetate, dimethyl glutarate, and dimethyl succinate. It is characterized by being at least one species.

Here, the polymethylmethacrylate (PMMA) beads (Bead) is characterized in that the particle size of 1 ~ 10㎛.

Here, the inorganic nanoparticle powder is a mixture of at least one 20 ~ 200nm size nanoparticle powder selected from the group consisting of SiO2, ZnO, TiO2 and 50 ~ 150㎛ size micropowder by means of a liquid chemistry method has an average diameter of 1 ~ It is characterized in that it is manufactured to have a 10㎛.

Here, the mixing ratio of the nano fine powder and the micro powder is characterized by mixing in a ratio of 50:50 ~ 30:70 by weight ratio.

Here, the additive is characterized by using at least one selected from the group consisting of a diluent, a dispersant, a silicone antifoaming agent and a leveling agent.

Here, the diluent is characterized in that using isophorone (Isophorone, C9H14O) or phenoxyethanol (phenoxyethanol, C8H10O2).

Here, the dispersant is characterized in that the sodium dodecyl surfate (SDS) or poly acrylic acid (PAA).

Here, the leveling agent is characterized in that any one of an acrylic copolymer (Acrylic copolymer), polyester resin (Polyester resin) or a mixture thereof.

Here, the solvent is dimethyl glutarate 18 wt%, dimethyl adipate 15 wt%, dimethyl succinate 7 wt%, diethylene glycol monoethyl ether acetate (Diethylene glycol monoethyl ether acetate) 40 to 60 wt% of the mixture.

The present invention provides a method of manufacturing a diffusion ink for light guide plate pattern formation of a backlight unit comprising the composition disclosed above.

At this time, the manufacturing method is slowly added to the solvent to include an acrylic copolymer containing methyl methacrylate (Methylmethacrylate) monomer as a main component 20 to 30% by weight relative to the total weight of the ink, 8 hours at 40 ~ 60 ℃ conditions After stirring homogeneously for a complete dissolution, the additive was added to a solution in which the acrylic copolymer was dissolved so as to include 20 to 40% by weight based on the total weight of the ink, stirred for 10 hours, and after stirring was completed, the diameter distribution was 0.1 Inorganic nanoparticles having a particle size of ~ 10 ㎛ is added to include 10 to 15% by weight relative to the total weight of the ink, it is characterized in that it is stirred for 8 hours at a temperature condition of 40 ~ 60 ℃ at a speed of 100 ~ 500rpm.

Here, the additive is characterized by using at least one selected from the group consisting of a diluent, a dispersant, a silicone antifoaming agent and a leveling agent.

Here, the additive is characterized in that it is added to include 40 to 70% by weight of the diluent, 1 to 5% by weight of the dispersant, 1 to 5% by weight of the silicone antifoaming agent and 1 to 2% by weight of the leveling agent.

The diffusion ink composition for light guide plate pattern formation of the backlight unit of the present invention can reduce ink manufacturing cost by using inorganic nanoparticle powder prepared by using liquid chemistry and improve brightness and printability by using nano-dispersion technology. Can be.

In addition, by using the ink composition composed of environmentally friendly materials, it is possible to protect the health of the workers in the field and to increase the image of the product by reducing the load on the global environment.

1 is an electron micrograph (SEM) of the inorganic nanoparticle powder used in the present invention.
2 is a schematic view of the light guide plate and its surroundings.
3 and 4 are photographs showing the behavior of light before and after nanodispersion, respectively.
5A and 5B show a method and a position of measuring luminance on the bottom surface of the light guide plate.
6 is a shape of a dot pattern observed by using an optical microscope by printing in a dot shape on the PMMA light guide plate by a silk screen printing technique.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a diffusion ink composition for forming a pattern on a light guide plate of a backlight unit of an LGP for a thin LED LCD, and uses inorganic nanoparticle powder prepared by liquid chemistry as a starting material.

According to the present invention, the composition is based on the total weight of the diffusion ink composition, 40 to 55% by weight solvent, 10 to 15% by weight inorganic nanoparticle powder, polymethylmethacrylate (PMMA) beads (bead) 10 to 20 weight %, 20 to 30% by weight of an acrylic copolymer containing methylmethacrylate (Methylmethacrylate) and 1 to 15% by weight of the additive is made.

The solvent is 1 selected from the group consisting of dimethyl adipate, diethylene glycol monoethyl ether acetate, dimethyl glutarate and dimethyl succinate. Use more than one species.

Preferably, a mixed solvent mixed with all of the solvents used is used. When the solvents are mixed, 18 wt% of dimethyl glutarate and dimethyl adipate are added to the total amount of the mixed solvent. ) 15 wt%, dimethyl succinate 7 wt%, diethylene glycol monoethyl ether acetate (Diethylene glycol monoethyl ether acetate) 40 to 70 wt% to be mixed.

The solvent is a substance for controlling viscosity and dissolving PMMA, and when the added amount thereof is less than the minimum value, the printability is lowered due to the increase of the viscosity, and when the solvent exceeds the maximum value, the viscosity becomes high to form a print pattern (thickness 10 to 15 μm). This becomes difficult.

The polymethyl methacrylate (PMMA) beads (Bead) is preferably used having a particle size of 1 ~ 10㎛. The reason is that having a particle size of less than 1 μm has a disadvantage in that light scattering property is inferior, and when it exceeds 10 μm, light transmittance may be low.

The inorganic nanoparticle powder is an average diameter of 0.1 ~ 10㎛ by liquid chemistry by mixing at least one 20 ~ 200nm size nanoparticle powder selected from the group consisting of SiO2, ZnO, TiO2 and 50 ~ 150㎛ size micropowder It is to use that prepared to have.

The inorganic nanoparticle powder plays a role of scattering the light of the LED light source. When the amount is less than the minimum value, the scattering degree of the light is lowered and the uniformity is lowered. Will be lowered. Therefore, it is necessary to add an appropriate amount of inorganic particles.

An example of the manufacturing process of the inorganic nanoparticle powder is as follows.

First, dissolve Zn (Ti, Si, Al) Acetate in distilled water to 70ml, then slowly add NaOH or Urea in 30ml of distilled water, and mix to make 100ml. After mixing the solution for 30 minutes by ultrasonic wave, the solution is placed in a Teflon tube hydrothermal synthesis container and sealed, and reacted at 120 to 220 ° C. for 5 to 12 hours. The obtained Zn (Ti, Si) O powder was washed with distilled water (DI water) four times and once with ethanol for 5 minutes at 2,000 rpm using a centrifugal separator and dried at 120 ° C for 12 hours, and then at 250-300 ° C for 12 hours. Heat treatment is performed to prepare nanoparticulate Zn (Ti, Si) O powder. The inorganic nanoparticle powder thus prepared is deposited on a hydrophilic silane coupling agent such as γ-Mercaptopropyltrimethoxysilane (HP-189) and subjected to surface treatment.

1 is an electron microscope (SEM) photograph of the inorganic nanoparticle powder used in the present invention, and shows an example of the inorganic nanoparticle powder prepared according to the above-described manufacturing method.

At this time, the mixing ratio of the nano fine powder and the micro powder is preferably mixed in a ratio of 50:50 to 30:70 by weight.

The additive is preferably at least one selected from the group consisting of diluents, dispersants, silicone antifoaming agent and leveling agent. More preferably, it is preferable to use two or more additives, and more preferably to use all the appropriate amounts of the additives.

Preferably all of the additives are mixed to include 40 to 70% by weight of the diluent, 1 to 5% by weight of the dispersant, 1 to 5% by weight of the silicone defoamer and 1 to 2% by weight of the leveling agent.

As the diluent, it is preferable to use isophorone (Isophorone, C9H14O) or phenoxyethanol (C8H10O2), which has a higher boiling point than conventionally used cyclohexanone (C6H10O).

The dispersant may be any one of sodium dodecyl sulfate (SDS), poly acrylic acid (PAA), or a mixture thereof, and more preferably, PAA.

The leveling agent may use any one of an acrylic copolymer, a polyester resin, or a mixture thereof, and more preferably, an acrylic copolymer.

The additive amount affects the dispersibility of the inorganic particles, but if the addition amount exceeds the maximum value, there is a problem in reliability, in particular, the film strength tends to be weak, and if less than the minimum value is added to the dispersibility. It becomes a problem and there exists a tendency for the uniformity of luminance to fall.

In the present invention, there is provided a method for producing a light guide plate pattern-forming diffusion ink of the composition of the present invention disclosed above.

The manufacturing method is gradually added to the acrylic copolymer containing a methyl methacrylate (Methylmethacrylate) monomer in the solvent to include 20 to 30% by weight relative to the total weight of the ink, and then homogeneous for 8 hours at 40 ~ 60 ℃ conditions After stirring, the solution was completely dissolved, and the additive was added to the dissolved solution in which the acrylic copolymer was dissolved so as to include 1 to 15% by weight based on the total weight of the ink, followed by stirring for 10 hours. After stirring was completed, the diameter distribution was 0.1 to 10 The inorganic nanoparticulate powder having a μm is added to contain 10 to 15% by weight based on the total weight of the ink, and the mixture is stirred for 8 hours at a temperature of 40 to 60 ° C. at a speed of 100 to 500 rpm.

At this time, the additive is at least one selected from the group consisting of a diluent, a dispersant, a silicone antifoaming agent and a leveling agent, preferably the additive is 40 to 70% by weight of the diluent, 1 to 5% by weight, silicone 1 to 5% by weight of the antifoaming agent and 1 to 2% by weight of the leveling agent.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. However, the following examples are provided to help the understanding of the present invention, and the present invention is not limited to the following examples.

[Example]

For the preparation of the solvent, 18 wt% of dimethyl glutarate, 15 wt% of dimethyl adipate, 7 wt% of dimethyl succinate, and diethylene glycol monoethyl based on the total amount of the solvent Prepare a solvent by mixing each of them to include 40 ~ 60 wt% of ether glycol (Diethylene glycol monoethyl ether acetate),

The total amount of the ink was gradually added to include 40 to 55 wt% of the solvent and 20 to 30 wt% of an acrylic copolymer containing methyl methacrylate monomer as a main component, followed by stirring at 40 to 60 ° C. for about 8 hours. Completely dissolved.

20 to 30 wt% of the solution in which the acrylic copolymer was dissolved, 1 to 5 wt% of the dispersant, 1 to 5 wt% of the silicone antifoaming agent, and 1 to 2 wt% of the leveling agent were added and stirred for 10 hours.

After complete stirring, 10-15 wt% of inorganic nanoparticle powder having a diameter distribution of 0.1 ~ 10㎛ was added and stirred for 8 hours while maintaining the temperature below 40 ~ 60 ℃ at a speed of 100 ~ 500rpm to complete the diffusion ink.

The ink prepared in the above example was printed in a dot shape on a PMMA light guide plate by a silk screen printing method to form a dot pattern as shown in FIG. 6.

[Comparative Example]

Conventional diffusion ink containing SiO 2 was printed in a dot shape on a PMMA light guide plate by a silk screen printing method to form a dot pattern.

2 is a schematic view of the light guide plate and its surroundings. In FIG. 2, the lamp reflector 10, the lamp 11, the patterned LGP ink 12, the LGP 13, and the direction of light 14 are shown.

3 and 4 show light behavior before and after nanodispersion, respectively. The transmitted light 20, the acrylic resin 21, the inorganic nanoparticles 22, and the reflected light 23 are shown, respectively.

5A and 5B show a method of measuring luminance (FIG. 5A) and a position (FIG. 5B) on the bottom surface of the light guide plate. As shown in the drawing, the diffusion ink and the comparative example of the present invention of the above embodiment are shown. A dot pattern was printed in a dot shape at each position (1 to 17) of the light guide plate 13 by using a diffusion ink of the light guide plate 13, and a light source was provided at both sides of the light guide plate 13, and according to each position (1 to 17) The luminance measurement results are shown in Tables 1 and 2 below. Table 1 is a measurement value for the ink (Example) containing the surface-treated inorganic nanoparticle powder of the present invention, Table 2 is a measurement value for the conventional ink (comparative example).

Referring to the accompanying drawings, the picture shown in Figure 1 is an electron micrograph (SEM) of the inorganic nanoparticle powder prepared by the liquid chemical method. The ink made by dispersing the powder together with the solvent is printed and used by silk screen printing as shown in FIG. As shown schematically in FIG. 3, there is agglomeration of inorganic particles in the ink prior to nanodispersion prepared in a conventional manner, but when nanodispersion technology is used as in FIG. 4, it is possible to homogeneously disperse inorganic nanopowders. It becomes possible.

As a result of the measurement of the luminance of the measuring device and the measuring point shown in FIG.

6 is a dot-shaped optical micrograph obtained by performing silk screen printing using the ink prepared as described above, and shows a very clean surface without ink bleeding or staining. It is excellent.

Measuring position Cd 度 (cd / ㎡) x 色 座標 y 色 座標 1p (center) 7472 0.286 0.297 2 6744 0.285 0.295 3 6962 0.285 0.295 4 6833 0.285 0.295 5 7039 0.286 0.297 6 7148 0.286 0.297 7 6849 0.285 0.297 8 7096 0.285 0.296 9 6950 0.285 0.296 10 6113 0.283 0.295 11 6521 0.284 0.294 12 6546 0.284 0.293 13 6384 0.286 0.299 14 6558 0.287 0.298 15 6270 0.283 0.296 16 6703 0.284 0.295 17 6594 0.284 0.295 Average (5P) 6970 0.286 0.297 Uniformity 1.11 90% Average (17P) 6752 0.285 0.296 Uniformity 1.22 82%

Measuring position Cd 度 (cd / ㎡) x 色 座標 y 色 座標 1p (center) 7250 0.287 0.298 2 6650 0.285 0.297 3 6725 0.286 0.297 4 6644 0.286 0.297 5 6763 0.287 0.299 6 6849 0.287 0.299 7 6796 0.286 0.298 8 7051 0.286 0.298 9 6850 0.286 0.297 10 6048 0.284 0.296 11 6444 0.284 0.295 12 6428 0.285 0.295 13 6270 0.287 0.300 14 6501 0.287 0.299 15 6250 0.284 0.298 16 6715 0.284 0.296 17 6509 0.284 0.296 Average (5P) 6838 0.287 0.298 Uniformity 1.09 92% Average (17P) 6632 0.285 0.297 Uniformity 1.20 83%

As shown in Tables 1 and 2 above, as a result of luminance measurement, in the case of the improved ink including the surface-treated inorganic nanoparticles of the present invention, the average luminance (cd / m 2) was about 2% (140 cd / m 2). It can be seen that the degree is improved.

As such, the diffusion ink composition of the present invention can be seen that the brightness is improved compared to the conventional ink, it can be used to improve the brightness of the backlight unit. That is, it is possible to ensure excellent luminance compared to the conventional ink.

The present invention described above is not limited to the above-described embodiments, and various permutations, modifications, and changes can be made without departing from the technical spirit of the present invention. It is clear to those who have it.

10: lamp reflector 11: lamp
12: patterned light guide plate ink 13: light guide plate
14: direction of light 20: transmitted light
21: acrylic resin 22: inorganic nanoparticles
23: reflected light

Claims (14)

Regarding the total weight of the diffusion ink composition,
Acrylic copolymer comprising 40 to 55% by weight of solvent, 10 to 15% by weight of inorganic nanoparticulate powder, 10 to 20% by weight of polymethylmethacrylate (PMMA) beads, and methylmethacrylate 20 to 30% by weight and additives 1 to 15% by weight,
The inorganic nanoparticle powder is mixed with a solution diluted with NaOH and one selected from the group Zn, Ti, Si Acetate, and the mixed solution through an ultrasonic mixing process for 30 minutes, and then 5 to 12 hours at 120 ~ 220 ℃ After reacting in a Teflon tube hydrothermal synthesis vessel to make one powder selected from the group Zn, Ti, Si Acetate, the powder was washed with distilled water and ethanol for 5 minutes at 2,000rpm using a centrifugal separator, and then at 120 ℃ After drying for 12 hours, the dried powder was heat-treated at 250-300 ° C. for 12 hours, and then immersed in a hydrophilic silane coupling agent to prepare a surface-treated nanoparticle powder having a size of 20-200 nm.
The diffusion ink composition for forming a light guide plate pattern of a backlight unit, characterized in that the nanoparticle powder and the micropowder of 50 ~ 150㎛ size is mixed to have an average diameter of 0.1 ~ 10㎛ by a liquid chemistry method.
The method of claim 1,
The solvent is 1 selected from the group consisting of dimethyl adipate, diethylene glycol monoethyl ether acetate, dimethyl glutarate and dimethyl succinate. Diffusion ink composition for light guide plate pattern formation of the backlight unit characterized by the above-mentioned.
The method of claim 1,
The polymethyl methacrylate (PMMA) beads (Bead) is a diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that the particle size of 1 ~ 10㎛.
delete The method of claim 1,
The mixing ratio of the nano fine powder and the micro powder is a diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that the mixing ratio by weight ratio of 50:50 ~ 30:70.
The method of claim 1,
The additive is a diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that at least one selected from the group consisting of a diluent, a dispersant, a silicone antifoaming agent and a leveling agent.
The method according to claim 6,
The diluent isophorone (Isophorone, C9H14O) or phenoxyethanol (phenoxyethanol, C8H10O2) is a diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that.
The method according to claim 6,
The dispersing agent is a diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that using any one of sodium dodecyl sulfate (SDS), poly acrylic acid (PAA) or a mixture thereof.
The method according to claim 6,
The leveling agent is a diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that any one of an acrylic copolymer (polycrylic copolymer), polyester resin (Polyester resin) or a mixture thereof.
The method of claim 1,
The solvent is dimethyl glutarate (18 wt%), dimethyl adipate (dimethyl adipate) 15 wt%, dimethyl succinate (7 wt%), dimethyl glycol monoethyl ether acetate (Diethylene glycol monoethyl) ether acetate) diffusion ink composition for forming a light guide plate pattern of the backlight unit, characterized in that mixing to include 40 ~ 60 wt%.
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