KR101840539B1 - Oled display device and production method thereof - Google Patents

Abstract

This OLED display device comprises an OLED panel 1, a? / 4 retardation film 3 pasted on the OLED panel 1 and a polarizing film 5 pasted on the? / 4 retardation film 3 And the reflectance measured in the SCE (Specular Component Excluded) mode at the polarizing film side is 1.2% or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an OLED display device,

The present invention relates to an OLED display device and a method of manufacturing the OLED display device which are capable of achieving uniform color reproduction by eliminating color nonuniformity due to scattering.

The organic light emitting diode (OLED) display device can be made lighter and thinner than a CRT (cathode ray tube) or an LCD (Liquid Crystal Display), and also has a wide viewing angle, a fast response speed, And has attracted attention as a next generation display device.

This OLED display device is used in various fields such as a cellular phone, a TV, a digital camera, a camcorder (registered trademark), a PC, and a navigation system.

The OLED panel constituting the OLED display device has electrodes of positive and negative electrodes. Generally, when light is incident on the OLED panel from the outside, light is reflected by the electrode portion of the organic light emitting diode inside the OLED panel. When a person looks at the OLED display device, the reflected light causes a problem such as a feeling of being dazzling, a color change, and a contrast lowering. This is because the intensity of reflected light that a person enters into the eyes increases, and the visibility decreases.

Particularly, in the case of a full-surface-emitting OLED, the reflectance of the display device itself increases due to the image defining layer for displaying an image or the reflective electrode positioned under the image defining layer.

To prevent reflection of external light, various methods have been proposed, such as changing the structure of the OLED panel or introducing a new layer.

In Patent Document 1, an antireflection film is formed on an anode, and glass or resin film having selective permeability is used as a material of the antireflection film.

Patent Document 2 proposes a method of introducing a substance that selectively absorbs external light in each wavelength band between an OLED panel and a sealing substrate for sealing the panel.

Patent Document 3 proposes a method in which a plurality of protruding light scattering spacers and a scattering capping layer are provided in the interior of an OLED panel to scatter external light reflected thereby to suppress reflection of external light. The ratio of the deterioration of the transmittance due to the diffusion of the material can be expressed by using a haze value. The larger the haze value, the higher the ratio of the transmitted light diffusing and becomes a hazy material. In this publication, the haze value (Haze) of the capping layer is set to 5 to 30%.

Patent Document 4 discloses a method of scattering external light reflected by a curved image defining film to suppress reflection of external light.

In such a method, the reflection of external light can not be sufficiently suppressed in some cases. In particular, in the case of a method of suppressing the reflection of external light by using scattering, a phenomenon of " non-uniformity " The non-uniformity refers to a state in which the characteristics of the screen are not uniform, and in particular, when the colors are uneven, the color nonuniformity is called. The color unevenness is a phenomenon in which, when the panel is displayed in monochrome, the entire screen does not show a uniform color, but there is a difference in color between places. For example, when white is displayed on the entire screen, it means that the entire screen can not express completely the same white. Such a color unevenness phenomenon occurs due to various causes such as a problem in a manufacturing process and a kind of a material constituting a panel, and analysis of the cause is very difficult.

In the method using scattering to suppress the reflection of external light, it is often difficult to identify the cause of the occurrence of the color unevenness phenomenon and to solve it. On the other hand, a method of using scattering is sometimes used as a method of introducing a light scattering layer into a panel or a method of containing a light scattering material in order to increase the light efficiency of an OLED display device.

Patent Document 5 discloses a light-transmissible substrate through which visible light is transmitted, a substrate having a light scattering portion for scattering visible light and a light-transmissive opening portion for transmitting visible light is used as a light- .

Patent Document 6 proposes an OLED display device having a plurality of insulating films having scattering patterns for scattering light emitted from the organic light emitting layer and having different refractive indexes of the adjacent insulating films.

Korean Patent Publication No. 2007-0003159 Korean Patent Publication No. 2011-0011420 U.S. Published Patent Application No. 2010/0171106 Korean Patent Registration No. 10-0742374 Korean Patent Publication No. 2005-0013918 Korean Patent Laid-Open Publication No. 2013-0016937

However, in the above-described prior art described above, a method using scattering employed to increase the light efficiency may cause a phenomenon of color unevenness caused by reflection of external light to be more seriously generated.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide an OLED display device and a method of manufacturing the OLED display device which can solve the color unevenness.

DISCLOSURE OF THE INVENTION The present inventors have conducted various studies in order to solve the above problems. As a result, the present inventors have found that, in order to remove reflected light on the surface of the panel, a polarizing film and a retardation film are pasted ) Was found to be preferable. This method can more easily reduce the color unevenness phenomenon than changing the internal structure of the panel. Particularly, in the OLED panel in which the polarizing film is laminated, specific parameters related to scattering for each constituent element are selected, and the selected parameters are objectively numerically controlled to eliminate color nonuniformity.

The first OLED display device includes an OLED panel, a? / 4 retardation film pasted on the OLED panel, and a polarizing film pasted on the? / 4 retardation film, wherein a specular component (SCE) ) Mode has a reflectance of 1.2% or less.

The second OLED display device is characterized by comprising a first pressure-sensitive adhesive interposed between the OLED panel and the? / 4 retardation film, and a second pressure-sensitive adhesive interposed between the? / 4 retardation film and the polarizing film .

In the third OLED display device, the first pressure sensitive adhesive and the second pressure sensitive adhesive both contain an acrylic resin.

The fourth OLED display device comprises an OLED panel, a? / 4 retardation film pasted on the OLED panel, and a polarizing film pasted on the? / 4 retardation film, wherein the SCE (Specular Component Excluded ) mode, the reflectivity measured in R _SCE and a ratio R _SCE / R _SCI of the reflectivity R _SCI measured at the polarizing film side in SCI (Specular Component Included) mode, the relation of the _{following: 0% <R SCE / R} SCI ≤ 20 %. &Lt; / RTI &gt;

The fifth OLED display device is an OLED display device having an OLED panel, a? / 4 retardation film pasted on the OLED panel, and a polarizing film pasted on the? / 4 retardation film, The retardation film and the polarizing film are removed and a ratio r _SCE of the reflectance r _SCE measured in the SCE mode on the surface of the light output side of the OLED panel and a reflectance r _SCI measured in the SCI mode on the surface side of the retardation film r _SCE / r _SCI is characterized by satisfying the following relationship: 0% <r _SCE / r _SCI ? 70%.

A method of manufacturing a sixth OLED display device includes an OLED panel, a? / 4 retardation film pasted on the OLED panel, and a polarizing film pasted on the? / 4 retardation film, The method comprising the steps of: attaching a? / 4 phase difference film on an OLED panel; and attaching a polarizing film on the? / 4 phase difference film And FIG.

The seventh OLED display device manufacturing method comprises: an OLED panel; a? / 4 retardation film pasted on the OLED panel; and a polarizing film pasted on the? / 4 retardation film, The method comprising the steps of: preparing a circularly polarizing plate by attaching a? / 4 retardation film on a polarizing film; and attaching the circularly polarizing plate onto the OLED panel, The method comprising:

According to the OLED display device of the present invention, color unevenness due to scattering can be solved and uniform color development can be achieved.

1 is a longitudinal sectional view of an OLED display device.
2 is a view showing the layer structure of an OLED and its driving circuit.
3 is a longitudinal sectional view of a sample of an OLED display device for verification.
4 is a photograph of the samples No. 1 to No. 5.
5 is a chart showing data of samples No. 1 to No. 5.
6 is a chart showing data of Sample Nos. 6 to 11.
7 is a chart showing data of Sample Nos. 12 to 15. FIG.

Hereinafter, an OLED (Organic Light-Emitting Diode) display device according to the embodiment will be described. The same reference numerals are used for the same elements, and a duplicate description will be omitted.

1 is a longitudinal sectional view of an OLED display device.

The OLED display 10 includes an OLED panel 1 and a lambda / 4 retardation film 3 bonded on the OLED panel 1 through a first adhesive 11 and a lambda / 4 retardation film 3 And a polarizing film 5 adhered with a second adhesive 12 interposed therebetween.

The OLED panel 1 includes a support substrate 1a made of glass or the like, a frame spacer 1b formed along the outer edge of the surface of the support substrate 1a and a frame spacer 1b 1b. The space between these substrates is sealed, and a plurality of light emitting elements are arranged in the space.

A plurality of thin film transistors Q are formed in a matrix on a support substrate 1a and the organic light emitting diodes R, G, and B are provided for each pixel via a coating layer 1c covering the thin film transistor Q. [ Respectively. The organic light emitting diodes (R, G, B) are light emitting diodes having an organic light emitting layer and can emit light of various wavelengths according to the layer structure. In this example, the red, green, and blue color filters F are provided between the organic light emitting diodes R, G, and B and the sealing substrate 1e, but these filters may be omitted.

Between the coating layer 1c and the sealing substrate 1e, there is a space 1d sealed with a gas. However, the space 1d may be filled with resin or the like.

The first adhesive agent 11 is coated or laminated on the sealing substrate 1e and the first adhesive agent adheres the? / 4 phase difference film 3 to the surface of the sealing substrate 1e. The second adhesive 12 is applied or laminated on the? / 4 retardation film 3 and the polarizer 5 adheres to the surface of the? / 4 retardation film 3 .

The polarizing film 5 is composed of a polarizer 5b and a first transparent protective film 5a and a second transparent protective film 5c formed on both sides of the polarizer 5b. The polarizer 5b is made of a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and oriented. The first transparent protective film 5a and the second transparent protective film 5c are not particularly limited as far as they have a protective function and are made of, for example, polyethylene terephthalate and triacetyl cellulose.

When the organic light emitting diodes R, G and B emit light, the light passes through the filter F, the sealing substrate 1e, the first pressure sensitive adhesive 11, the? / 4 retardation film 3, the second pressure sensitive adhesive 12 ), And a polarizing film 5 in this order.

In addition, light from the outside is reflected at various points in the OLED display device and reflected to the outside. Particularly, the electrode located on the surface of the organic light emitting diodes (R, G, B) has a high reflectance, and therefore, the influence of the reflection is large.

2 is a view showing the layer structure of an organic light emitting diode and its driving circuit. One of the above-described organic light emitting diodes (R, G, B) is represented by reference numeral 10 '.

The OLED 10 'includes a cathode electrode Ec, an electron transport layer 10a formed on the cathode electrode Ec, a light emitting layer 10b, a hole transport layer 10c, and an anode electrode Ea have. When the thin film transistor Q is turned ON, a forward bias voltage between the power source potential Vc and the ground is applied to the OLED 10 '. When a forward bias voltage is applied between the cathode electrode Ec and the anode electrode Ea, a current flows through the cathode electrode Ec and electrons flow from the anode electrode Ea into the light-emitting layer 10b , And electrons and holes are recombined in the light emitting layer 10b to emit light. As the electron transporting layer 10a, a metal complex material (tris (8-quinolinolato) aluminum), an oxadiazole-based material (PBD: 2 - (4-Biphenylyl) -5-phenyl-4-t-butulphenyl) -1,3,4-oxadiazole, and triazole-based materials (TAZ). As the light-emitting layer 10b, a π conjugated polymer, a dye-containing polymer, or the like can be used. In addition, the OLED 10 'is composed of various materials, and the present invention is not limited thereto.

As described above, the OLED display device 10 has a structure in which the polarizing film 5 is placed on the OLED panel 1 and the lambda / 4 retardation film 3 is located therebetween. The OLED panel 1 is not limited to the one disclosed here, and a conventionally known one can be applied. The OLED panel 1 has a structure in which an anode and a cathode are stacked on a substrate, and at least one organic thin film layer is disposed between the cathode and the anode. Since these structures are well known in the art, a detailed description thereof will be omitted.

The anode electrode Ea may be formed of, for example, a metal oxide such as ITO, IZO, IGZO, tin oxide, zinc oxide, zinc aluminum oxide, and titanium nitride, or metal nitride; Metals such as gold, platinum, silver, copper, aluminum, nickel, cobalt, lead, molybdenum, tungsten, tantalum and niobium; Alloys of these metals or alloys of iodine compounds of copper; At least any of conductive polymer materials such as polyaniline, polypyrrole, polyphenylene vinylene, and poly (3-methylthiophene). The anode electrode may be formed of any of the above-described components, or may be formed of a mixture of a plurality of materials. In addition, a multilayer structure composed of a plurality of layers of the same composition or different compositions may be formed.

As the cathode electrode Ec, a material known in the art can be used, and there is no limitation, and LiF can be used as an electron injection layer and used for a cathode of a metal having a low work function such as Al, Ca, Mg, And preferably Al is preferable.

The organic thin film layer positioned between the anode electrode Ea and the cathode electrode Ec contains the light emitting layer 10b in order to realize light emission of red, green and blue. In addition, the organic thin film layer positioned between the anode electrode Ea and the cathode electrode Ec includes a hole injection layer, , An electron injection layer, and an electron transport layer. For example, it may have a laminated structure composed of an anode electrode, a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an electron injecting layer, and a cathode electrode.

As the light emitting layer 10b, a dopant material can be used in addition to a host material which is a main material. As the host material and the dopant material, various kinds of materials are known, and the present invention is not limited thereto. Various types of hole injection layers, hole transporting layers, electron transporting layers, and electron injecting layers are also known, and the present invention is not limited thereto.

As the driving method of the OLED panel 1, there are passive (PM) type and active (AM) type, but both are applicable.

As the material of the anode electrode Ea and the cathode electrode Ec, metals such as gold, silver, copper, and aluminum can be used. For example, when aluminum is used as the anode electrode Ea, the anode electrode Ea also functions as a mirror for reflecting light from the outside. The cathode electrode Ec is also the same. When a metal film such as aluminum is deposited on the back surface of the sealing substrate 1e (the surface opposite to the surface on which the pressure-sensitive adhesive layer 11 is formed) of FIG. 1 to form a mirror and its optical properties are examined, Are considered to exhibit substantially the same behavior as in the case of the OLED display device. Therefore, the inventors of the present invention produced such an OLED display for verification, and conducted an intensive study on optical characteristics.

3 is a longitudinal sectional view of a sample of an OLED display device for verification.

The OLED display device for verification includes an OLED panel 1D for verification in place of the OLED panel 1. A metal film of aluminum or the like is deposited on the back surface of the sealing substrate 1e in Fig. 1 (the surface opposite to the surface on which the pressure-sensitive adhesive layer 11 is formed), and this is virtually bonded to the anode electrode Ea and the cathode electrode Ec Ez in Fig. 3). In the OLED panel 1D for verification, the remaining elements of the OLED panel 1 are omitted.

In the explanation, there are cases where the following three equations (1) to (3) are cited.

(Formula 1): R _SCE ? 1.2%

(Equation 2): 0% < R _SCE / R _SCI &lt; 20%

(Equation 3): 0% <r _SCE / r _SCI ≤ 70%

(Equation 1) shows the OLED panel 1 described above, the? / 4 phase difference film 3 pasted on the OLED panel 1, and the polarizing film pasted on the? / 4 phase difference film 3 5, and the reflectance R _SCE measured in the SCE (Specular Component Excluded) mode at the polarizing film 5 side is 1.2% or less.

(Equation 2) shows the OLED panel 1 described above, the? / 4 phase difference film 3 pasted on the OLED panel 1 and the polarizing film The ratio of the reflectance R _SCE measured in the SCE (Specular Component Excluded) mode on the polarizing film 5 side to the reflectance R _SCI measured in the SCI (Specular Component Included) mode on the polarizing film 5 side, R _SCE / R _SCI .

On the other hand, (Equation 3) shows that in this state, the? / 4 retardation film 3 and the polarizing film 5 are removed and the surface of the OLED panel 1 (1D) It is a relational expression that satisfies the ratio r _SCE / r _SCI of the reflectance r _SCE measured in the SCE mode and the reflectance r _SCI measured in the SCI mode on the surface side. When any one, two or all of the relational expressions (1) to (3) are satisfied, the color non-uniformity (color nonuniformity phenomenon) is improved. It is preferable that (Expression 1) is satisfied in the relational expressions of (Expression 1) to (Expression 3), and that Expression 1 is satisfied and that Expression 2, Expression 3 or Expression 2, 3) are satisfied.

(B) the? / 4 retardation film (3), (C) the first adhesive 11 and the second adhesive 12, (D) the polarizing film 5, A support substrate 1e, and (E) a metal film or a metal sheet as the anode electrode Ea.

Hereinafter, the relationship between the above-described (Expression 1) to (Expression 3) and the color non-uniformity will be described together with the respective elements (A) to (E).

(A) Polarizing film (5)

(A-1) Characteristics of Polarizing Film

The polarizing film 5 serves to convert natural light (external light) incident from the outside into linearly polarized light and to block reflected light from the OLED panel to suppress reflection of external light. The parameters related to the optical characteristics of the polarizing film 5 include a simple transmittance Ty, a parallel transmittance Tp, an orthogonal transmittance Tc, a polarization degree a ^* , b ^*, and the like.

Since the polarizing film 5 is stacked on the OLED panel 1 together with the above functions, it is necessary to consider the unit transmissivity Ty in consideration of the light output efficiency from the OLED panel 1, It is necessary to adjust the value of the b ^* in consideration of the b ^* value so that the device 10 can express a clear blue color.

(A-2) Bulk transmittance (Ty)

The percent of the simple transmittance (Ty) of the polarizing film (5) is 50% as the theoretical value, and it is preferable that the following relationship is satisfied in order to satisfy the above-mentioned (Equation 2).

40%? Ty? 44.95%

If the numerical range of the Ty is smaller than the lower limit of the range of the above-mentioned relational expression, it is necessary to increase the output of the OLED panel 1 in order to obtain a luminance higher than a certain level. As a result, do. When the numerical value range of Ty is larger than the upper limit value of the range of the above-mentioned relational expression, external light can not be converted into linearly polarized light sufficiently, resulting in a problem that the reflectance of external light is increased.

(A-3) b ^* value

The b ^* value indicates a blue color with a negative value, and a yellow color with a positive value. The b ^* value of the polarizing film 5 is preferably an orthogonal b ^* value. Preferably, the polarizing film 5 of the present invention has an orthogonal b ^* value of -15 or more and 0 or less in order to satisfy (Equation 2). That is, the following relation is satisfied.

-15? B ^* ? 0

When the b ^* value is larger than 0 (for example, +5), it is difficult to realize a clear blue color. When the b ^* value is smaller than -15, there arises a problem that the reflectance of external light is increased. .

In the polarizing film 5, although there is a preferable range of the simple transmittance (Ty) and a preferable range of the orthogonal b ^* value, it is preferable that the polarizing film (5) satisfies at least one preferable range and satisfies both preferred ranges More preferable.

The polarizing film 5 is usually composed of a polarizer and transparent protective films on both sides thereof.

(A-4) Polarizer in polarizing film

As the material of the polarizer in the polarizing film, the following materials can be used.

As described above, the polarizer constituting the polarizing film is one obtained by orienting a dichroic dye in a monoaxially stretched polyvinyl alcohol resin film. These polyvinyl alcohol resins may be modified, and for example, polyvinyl formal, polyvinyl acetal, polyvinyl butyral and the like modified with aldehydes may be used.

A film of such a polyvinyl alcohol-based resin is used as a raw film of a polarizing film. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and a film can be formed by a conventionally known appropriate method. The film thickness of the textile film made of the polyvinyl alcohol-based resin is not particularly limited, but is, for example, about 10 to 150 占 퐉. Is usually supplied in a roll form and has a thickness in the range of 20 to 100 mu m, preferably 30 to 80 mu m, and an industrially practical width of 1500 to 6000 mm.

The fabric thickness of a commercially available polyvinyl alcohol film (Vinylon VF-PS # 7500, manufactured by Kuraray Co., Ltd. / OPL Film M-7500, manufactured by Nippon Shokubai Co., Ltd.) was 75 μm, (Vinylon VF-PS # 6000, -PE &amp;num; 6000, manufactured by Kuraray Co., Ltd.) has a thickness of 60 mu m.

The polarizing film is usually formed by a process of dyeing a polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye (dyeing process), a process of treating a polyvinyl alcohol resin film adsorbed with a dichroic dye with an aqueous solution of boric acid (Boric acid treatment step), and a step of washing with water after the treatment with the aqueous solution of boric acid (water washing step).

In producing the polarizing film, the polyvinyl alcohol-based resin film is usually uniaxially stretched. However, the uniaxial stretching may be performed before the dyeing process, during the dyeing process, or after the dyeing process . In the case where the uniaxial stretching is carried out after the dyeing treatment step, the uniaxial stretching may be carried out before the boric acid treatment step or during the boric acid treatment step. Of course, it is also possible to perform uniaxial stretching in these plural stages.

The dyeing by the dichroic dye of the polyvinyl alcohol-based resin film in the dyeing treatment step is carried out, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. As the dichroic dye, for example, iodine, a dichroic dye or the like is used. The dichroic dye includes, for example, a dichroic dye made of a disazo compound such as C. I. DIRECT RED 39, and a dichroic dye made of a compound such as trisazo or tetrakisazo. The polyvinyl alcohol-based resin film is preferably subjected to immersion treatment with water before the dyeing treatment.

When iodine is used as the dichroic dye, a method in which a polyvinyl alcohol resin film is dipped in an aqueous solution containing iodine and potassium iodide is generally employed. The content of iodine in this aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye, the temperature of the aqueous solution used for dyeing is usually 20 to 40 占 폚, and the immersion time (dyeing time) for this aqueous solution is usually 20 to 1800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method in which a polyvinyl alcohol resin film is dipped in an aqueous solution containing a dichroic dye is generally employed. The content of the dichroic dye in this aqueous solution, and typically water per 100 parts by weight of 1 × 10 ^-4 ~ 10 parts by weight, preferably from 1 × 10 ^-3 ~ 1 parts by weight, particularly preferably 1 × 10 ^{- 3} to 1 x 10 ^-2 parts by weight. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. When a dichroic dye is used as the dichroic dye, the dye aqueous solution used for dyeing usually has a temperature of 20 to 80 캜, and the immersion time (dyeing time) for the aqueous solution is usually 10 to 1800 seconds to be.

The boric acid treatment step is carried out by immersing a polyvinyl alcohol-based resin film dyed by a dichroic dye into an aqueous solution containing boric acid. The amount of boric acid in the boric acid-containing aqueous solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. When iodine is used as the dichroic dye in the above-described dyeing process, it is preferable that the boric acid-containing aqueous solution used in the boric acid treatment process contains potassium iodide. In this case, the amount of potassium iodide in the boric acid-containing aqueous solution is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. The immersion time for the boric acid-containing aqueous solution is usually 60 to 1200 seconds, preferably 150 to 600 seconds, more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 40 占 폚 or higher, preferably 50 to 85 占 폚, and more preferably 55 to 75 占 폚.

In the subsequent water washing treatment step, the polyvinyl alcohol resin film after the boric acid treatment described above is subjected to water washing treatment, for example, by soaking in water. The temperature of water in the water washing treatment is usually 4 to 40 占 폚, and the immersion time is usually 1 to 120 seconds. After the water washing treatment, a drying treatment is usually carried out to obtain a polarizing film. The drying treatment is preferably carried out by using, for example, a hot-air dryer, a far-infrared heater or the like. The temperature of the drying treatment is usually 30 to 100 占 폚, preferably 50 to 80 占 폚. The drying treatment time is usually 60 to 600 seconds, preferably 120 to 600 seconds.

Thus, the polyvinyl alcohol-based resin film is subjected to uniaxial stretching, dyeing with a dichroic dye, boric acid treatment and washing treatment to obtain a polarizing film. The thickness of the polarizing film is usually in the range of 5 to 50 占 퐉.

(A-5) A transparent protective film in a polarizing film

The transparent protective film is used to protect the polarizer because it is mechanically weak. Depending on the type of the resin forming the transparent protective film, the moisture permeability is different and can be selected depending on the transparency, mechanical strength, thermal stability, moisture barrier property and isotropy. The material for forming the transparent protective film is not limited, and any material known in the art can be used.

Though the thickness of the transparent protective film is not limited, if it is too thin, the strength and workability are deteriorated. If it is too thick, the transparency is lowered. The thickness of the transparent protective film may be 5 to 200 占 퐉 or less, preferably 10 to 150 占 퐉 or less, and more preferably 20 to 100 占 퐉 or less.

As the transparent protective film of the polarizer, an adhesive or a pressure-sensitive adhesive may be used. Examples of the adhesive include a solvent type adhesive, an emulsion type adhesive, a pressure sensitive adhesive, a solventless type adhesive, a film type adhesive, a hot melt type adhesive and the like. As a preferable adhesive, an aqueous adhesive, that is, a raw material for an adhesive may be dissolved or dispersed in water. There is no particular limitation on the type of the water-based adhesive as long as it can sufficiently bond the polarizer and the transparent protective film, has excellent optical transmittance, and is not changed in color such as yellow. For example, a polyvinyl alcohol-based resin or a urethane-based resin having a hydrophilic group. Waterborne adhesives can be prepared by mixing with water with additional additives incorporated into the adhesive raw material. And commercially available polyvinyl alcohol resins of water-based adhesives include "KL-318" (trade name) of carboxylic acid-modified polyvinyl alcohol sold by Kuraray Co., Ltd.

As the pressure-sensitive adhesive for use as the transparent protective film, acrylic, silicone, rubber, urethane, polyester or epoxy copolymer may be used, and an acrylic copolymer, more preferably a pressure-sensitive acrylic pressure- .

The bonding of the transparent protective film to the polarizer can be carried out by a method commonly known in the art. For example, a polarizer, a transparent protective film, or a polarizer can be formed by a wire bar coating method, a gravure coating method, a die coating method, There is a method of applying an adhesive or a pressure-sensitive adhesive on both bonding surfaces, and bonding these surfaces.

The surface of the transparent protective film can be suitably subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet ray irradiation treatment, flame treatment, saponification treatment, etc., in order to increase adhesion between the transparent protective film and the polarizer .

(B)? / 4 retardation film (3)

(B-1) Function and performance of? / 4 retardation film

The? / 4 retardation film 3 laminated on the OLED panel 1 together with the polarizing film 5 has circularly polarized light (right circularly polarized light or left circularly polarized light) by phase difference from linearly polarized light from the polarizing film 5, And converts the circularly polarized light (left circularly polarized light or right circularly polarized light) reflected by the OLED panel 1 back to linearly polarized light (the oscillation direction of the linearly polarized light at that time coincides with the absorption axis of the polarizing film) have.

The method of manufacturing an OLED display device includes an OLED panel 1, a? / 4 phase difference film 3 pasted on the OLED panel 1, a polarizing film pasted on the? / 4 phase difference film 3, And a reflectance measured in a SCE (Specular Component Excluded) mode on the side of the polarizing film (5) is 1.2% or less. The OLED panel (1) 3), and a step of attaching the polarizing film 5 on the? / 4 phase difference film (3).

The method of manufacturing an OLED display device includes an OLED panel 1, a? / 4 phase difference film 3 pasted on the OLED panel 1, a polarizing film pasted on the? / 4 phase difference film 3, And a reflectance measured in a SCE (Specular Component Excluded) mode at the side of the polarizing film (5) is 1.2% or less, characterized in that the polarizing film (5) 3) to produce a circularly polarizing plate, and a step of pasting the circularly polarizing plate onto the OLED panel 1.

The parameter related to the optical characteristic of the lambda / 4 retardation film 3 is the in-plane retardation value Ro, and it is necessary to consider the in-plane retardation value Ro in order to prevent reflection of the OLED display device.

The retardation value Ro of the measurement of 550 nm of the? / 4 retardation film 3 is in the range of 130 nm to 155 nm, preferably 135 to 150 nm. If the retardation value is outside the range of the in-plane retardation value (Ro), the reflectance of the OLED display increases and the antireflection effect deteriorates.

In the case where light having a wavelength? = 550 nm is incident, it is preferable that the shift amount of the generated retardation in the plane is in the above-described range. That is, when the film thickness uniformity of the? / 4 retardation film 3 is high and the in-plane retardation value is in the vicinity of 137 nm, which is one fourth of the incident wavelength 550 nm, an increase in reflectance It is thought not to do.

(B-2) Material of? / 4 retardation film

As the lambda / 4 retardation film 3, there is a lambda / 4 liquid crystal coating layer formed by liquid crystal coating or a lambda / 4 stretched retardation film obtained by stretching the film. As a material for forming the? / 4 liquid crystal coating layer by the liquid crystal coating, for example, a polymerizable liquid crystal having a polymerizable group capable of crosslinking by heat or light can be used. The optical characteristics of the? / 4 liquid crystal coating layer formed of the polymerizable liquid crystal can be controlled according to the orientation state of the polymerizable liquid crystal.

Polymerizable liquid crystals include rod-like polymerizable liquid crystals and disc-shaped polymerizable liquid crystals.

When the rod-shaped polymerizable liquid crystal is horizontally or vertically aligned with respect to the substrate, the optical axis of the polymerizable liquid crystal coincides with the major axis direction of the polymerizable liquid crystal.

When the polymerizable liquid crystal on the disk is oriented, the optical axis of the polymerizable liquid crystal exists in a direction orthogonal to the original direction of the polymerizable liquid crystal.

In order for the layer formed by polymerization of the polymerizable liquid crystal to exhibit the in-plane retardation, the polymerizable liquid crystal may be oriented in a suitable direction. In the case where the polymerizable liquid crystal has a rod shape, the in-plane retardation is expressed by aligning the optical axis of the polymerizable liquid crystal horizontally with respect to the substrate plane. In this case, the optical axis direction and the slow axis direction coincide with each other. When the polymerizable liquid crystal is in the original phase, the in-plane retardation is expressed by aligning the optical axis of the polymerizable liquid crystal horizontally with respect to the substrate plane. In this case, the optical axis and the slow axis are orthogonal. The alignment state of the polymerizable liquid crystal can be adjusted by a combination of the alignment film and the polymerizable liquid crystal.

&Lt; Polymerizable liquid crystal &

The polymerizable liquid crystal is a compound having a polymerizable group and having liquid crystallinity. The polymerizable group means a group participating in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group means a group capable of participating in the polymerization reaction by an active radical or acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group . Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The liquid crystalline property of the polymerizable liquid crystal may be either a thermotropic liquid crystal or a lyotropic liquid crystal, and the thermotropic liquid crystal may be classified into a nematic liquid crystal or a smectic liquid crystal.

Specific examples of the polymerizable liquid crystal include a liquid crystal display device described in &quot; 3. 8. 6 Network (full bridge type) &quot; 5. 1 liquid crystal material b. Polymerizable nematic liquid crystal material ", compounds having a polymerizable group, compounds disclosed in JP-A-2002-267838, JP-A-2005-208415, JP-A-2005-208416, JP- 208414, JP-A-2006-052001, JP-A-2010-270108, JP-A-2010-31223, JP-A-2011-6360, JP-A-2011-207765, The polymerizable liquid crystal described in Patent Publication No. 2010-522893, Japanese Patent Publication No. 2011-207765, US Patent No. 6,139,771, US Patent No. 6,203,724, and US Patent No. 5,567,349.

&Lt; Composition for forming a liquid crystal coating layer &

The layer (liquid crystal coating layer) formed by polymerizing the polymerizable liquid crystal is usually prepared by coating a composition containing at least one polymerizable liquid crystal (hereinafter sometimes referred to as a composition for forming a liquid crystal coating layer) on a substrate, And polymerizing the polymerizable liquid crystal in the obtained coating film.

The composition for forming a liquid crystal coating layer usually contains a solvent. As the solvent, a solvent capable of dissolving the polymerizable liquid crystal and a solvent inert to the polymerization reaction of the polymerizable liquid crystal is more preferable.

The content of the solvent in the composition for forming a liquid crystal coating layer is generally from 10 parts by mass to 10000 parts by mass, more preferably from 50 parts by mass to 5000 parts by mass, based on 100 parts by mass of the solid content. The solid content means the total of the components excluding the solvent from the composition for forming a liquid crystal coating layer.

The application of the composition for forming a liquid crystal coating layer is carried out by a coating method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a slit coating method, a bar coating method and an applicator method, &Lt; / RTI &gt; After the application, the solvent is usually removed under the condition that the polymerizable liquid crystal contained in the obtained coating film is not polymerized, whereby a dry film is formed. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method and a reduced pressure drying method.

<Description>

The substrate is typically a transparent substrate. Means a substrate having transparency capable of transmitting light, in particular, visible light, and transparency means a property that a transmittance to a light ray having a wavelength of 380 to 780 nm is 80% or more. As a specific transparent substrate, a translucent resin substrate can be mentioned. Examples of the resin constituting the light transmitting resin base material include polyolefins such as polyethylene and polypropylene; Cyclic olefin-based resins such as norbornene-based polymers; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylic acid esters; Polyacrylic acid esters; Cellulose esters such as triacetylcellulose, diacetylcellulose, and cellulose acetate propionate; Polyethylene naphthalate; Polycarbonate; Polysulfone; Polyethersulfone; Polyether ketones; Polyphenylene sulfide, and polyphenylene oxide. Polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cyclic olefin resin or polycarbonate are preferable from the viewpoints of easiness of obtaining and transparency.

<Orientation film>

The alignment film in the present invention has an alignment regulating force for aligning the polymerizable liquid crystal in a desired direction.

It is preferable that the alignment film has a solvent resistance that is not dissolved by application of a composition for forming a liquid crystal coating layer or the like and has heat resistance in a heat treatment for removing a solvent or for orienting a polymerizable liquid crystal. Examples of such an orientation film include an orientation film containing an orientation polymer and a photo alignment film, and can be obtained by applying a composition for forming an orientation polymer or a composition for forming a photo alignment film to a substrate.

Examples of the method of applying the composition for forming an oriented polymer or the composition for forming a photo alignment layer to a substrate include a coating method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a slit coating method, a bar coating method, , Printing method such as flex printing method, and the like. When the optical film is produced by a continuous production method of a roll to roll type to be described later, a printing method such as a gravure coating method, a die coating method, or a flexo printing method is usually employed for the coating method.

The thickness of the alignment film is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm, more preferably 500 nm or less, and more preferably 10 nm to 500 nm.

The composition for forming a liquid crystal coating layer may contain a reactive additive.

As the reactive additive, it is preferable to have a carbon-carbon unsaturated bond and an active hydrogen-reactive group in the molecule. The term "active hydrogen-reactive group" as used herein means a group having reactivity with a group having an active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH 2) and the like and includes a glycidyl group, A carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, and a maleic anhydride group. The number of carbon-carbon unsaturated bonds and reactive hydrogen reactive groups of the reactive additive is usually 1 to 20, preferably 1 to 10, respectively.

The composition for forming a liquid crystal coating layer preferably contains at least one leveling agent. The leveling agent has a function of adjusting the fluidity of the composition for forming a liquid crystal coating layer to make the coating film more flat by applying the composition for forming a liquid crystal coating layer, and specifically, a surfactant can be mentioned. As the leveling agent, at least one type selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component is preferable.

When the composition for forming a liquid crystal coating layer contains a leveling agent, its content is preferably 0.05 parts by mass or more and 5 parts by mass or less, more preferably 0.05 parts by mass or more and 3 parts by mass or less, based on 100 parts by mass of the polymerizable liquid crystal . When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal, and the obtained? / 4 liquid crystal coating layer tends to become smoother.

The composition for forming a liquid crystal coating layer preferably contains at least one kind of polymerization initiator. The polymerization initiator is a compound capable of initiating polymerization reaction of the polymerizable liquid crystal and is preferably a photopolymerization initiator in that polymerization reaction can be initiated at a lower temperature. Specifically, there can be mentioned a photopolymerization initiator capable of generating an active radical or an acid by the action of light, and among these, a photopolymerization initiator which generates a radical by the action of light is preferable.

When the composition for forming a liquid crystal coating layer contains a polymerization initiator, the content thereof can be appropriately adjusted according to the kind and amount of the polymerizable liquid crystal contained in the composition, but it is preferably from 0.1 to 30 mass parts per 100 mass parts of the polymerizable liquid crystal More preferably 0.5 to 10 parts by mass, still more preferably 0.5 to 8 parts by mass. If the content of the polymerization initiator is within this range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal.

When the composition for forming a liquid crystal coating layer contains a photopolymerization initiator, the composition may further contain a photosensitizer. Examples of the photosensitizer include xanthene compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone, 2-isopropylthioxanthone and the like); Anthracene compounds such as anthracene, alkoxy group-containing anthracene (for example, dibutoxyanthracene and the like); Phenothiazine, and rubrene.

When the composition for forming a liquid crystal coating layer contains a photopolymerization initiator and a photosensitizer, the polymerization reaction of the polymerizable liquid crystal contained in the composition can be further promoted. The amount of the photosensitizer to be used can be appropriately adjusted according to the type and amount of the photo polymerization initiator and the polymerizable liquid crystal, but is preferably from 0.1 to 30 parts by mass, more preferably from 0.5 to 10 parts by mass, per 100 parts by mass of the polymerizable liquid crystal And more preferably 0.5 to 8 parts by mass.

In order to more stably proceed the polymerization reaction of the polymerizable liquid crystal, the liquid crystal coating layer-forming composition may contain an appropriate amount of a polymerization inhibitor. This makes it easy to control the progress of the polymerization reaction of the polymerizable liquid crystal.

Examples of the polymerization inhibitor include hydroquinone, an alkoxy group-containing hydroquinone, an alkoxy group-containing catechol (such as butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy Radical supplements such as radicals; Thiophenols; ? -naphthyl amines,? -naphthyl amines and? -naphthols.

When the composition for forming a liquid crystal coating layer contains a polymerization inhibitor, the content thereof can be appropriately adjusted depending on the kind and amount of the polymerizable liquid crystal, the amount of the photosensitizer, and the like. However, To 30 parts by mass, more preferably 0.5 to 10 parts by mass, still more preferably 0.5 to 8 parts by mass. If the content of the polymerization inhibitor is within this range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal.

The polymerization of the polymerizable liquid crystal can be carried out by a known method of polymerizing a compound having a polymerizable group. Specifically, thermal polymerization and photopolymerization can be exemplified, and from the viewpoint of easy polymerization, photopolymerization is preferable. In the case of polymerizing a polymerizable liquid crystal by photopolymerization, the polymerizable liquid crystal composition in a dried film obtained by applying a polymerizable liquid crystal composition containing a photopolymerization initiator and drying the polymerizable liquid crystal is converted into a liquid crystal state, , It is preferable to carry out photopolymerization.

The lambda / 4 stretched retardation film 3 is preferably formed by a solution film method or an extrusion molding method and stretching the film. The? / 4 stretched retardation film is a longitudinal (uniaxial) stretching film stretched in the machine direction; A transverse uniaxial stretching that stretches in a direction orthogonal to the direction of the machine flow; Biaxial stretching in which longitudinal and transverse stretching are carried out at the same time, and preferably a warp stretched film is applied.

At this point, the material used in the stretching method is not limited, and specifically, the intrinsic birefringence value can be produced by using raw materials of positive, negative, or a combination thereof. The above-mentioned &quot; material having a positive intrinsic birefringence value &quot; means a material exhibiting optically positive uniaxiality when the molecules are oriented in a uniaxial order. For example, in the case of the positive material resin, it means that the refractive index in the molecular orientation direction is larger than that in the direction orthogonal to the above-mentioned orientation direction.

The &quot; material having a negative intrinsic birefringence value &quot; as used herein means a material exhibiting optically negative uniaxiality when molecules are oriented in a uniaxial order.

For example, in the case of a negative raw material resin, it means that the refractive index in the molecular orientation direction becomes smaller than the refractive index of light in the direction orthogonal to the above-mentioned orientation direction.

Specifically, as the material used in the stretching method, polyolefins such as polyethylene and polypropylene; Cyclic olefin-based resins such as norbornene-based polymers; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylic acid esters; Polyacrylic acid esters; Cellulose esters such as triacetylcellulose, diacetylcellulose, and cellulose acetate propionate; Polyethylene naphthalate; Polycarbonate; Polysulfone; Polyethersulfone; Polyether ketones; Polyphenylene sulfide, and polyphenylene oxide.

The thickness of the? / 4 retardation film is usually 10 占 퐉 or less, preferably 5 占 퐉 or less, more preferably 0.5 占 퐉 or more and 5 占 퐉 or less in the case of? / 4 liquid crystal coating layer. In the case of a? / 4 stretched retardation film, it is usually 100 μm or less, preferably 60 μm or less, more preferably 5 μm or more and 50 μm or less.

(C) The first pressure-sensitive adhesive (11) and the second pressure-sensitive adhesive (12)

The? / 4 retardation film 3 and the polarizing film 5 laminated on the OLED panel 1 constituting the OLED display device 10 can be bonded by an adhesive. The first pressure sensitive adhesive 11 and the second pressure sensitive adhesive 12 preferably exhibit adhesive properties including excellent optical transparency, appropriate cohesiveness and adhesiveness, and particularly preferably excellent durability. Examples of the optimum pressure sensitive adhesive for forming the first and second pressure sensitive adhesives include acrylic, silicone, rubber, urethane, polyester, and copolymer, and preferably acrylic copolymer, Based acrylic adhesive. An adhesive may be used instead of the second adhesive.

Various additives may be added to the pressure-sensitive adhesive. Specific additives include silane coupling agents and antistatic agents. The silane coupling agent is effective for improving adhesion to glass, and the antistatic agent can be used to reduce or suppress the generation of static electricity. The method of laminating the first and second pressure-sensitive adhesives on the polarizing film is not particularly limited as long as it is a method commonly used in the art. For example, a coating agent for forming an adhesive layer may be applied to the surface of the polarizing film 5, dried, and laminated. Further, a pressure-sensitive adhesive layer may be formed on the silicone-coated release film by the same application method as described above to produce a pressure-sensitive adhesive sheet, and then the pressure-sensitive adhesive sheet may be laminated by using these rolls. The thickness of the first and second pressure-sensitive adhesives described above can be adjusted depending on the tackiness, and is usually from 3 탆 to 100 탆, and more preferably from 3 탆 to 20 탆.

Examples of the first pressure-sensitive adhesive include pressure-sensitive adhesives described in International Publication No. WO2012 / 173066. Specifically, it contains an acrylic resin and spherical fine particles; The difference in refractive index between the acrylic resin and the spherical fine particles is in the range of more than 0.01 and less than 0.09; The acrylic resin is a mixture of a high molecular weight acrylic resin having a weight average molecular weight in the range of 500,000 to 2,000,000 and a low molecular weight acrylic resin having a weight average molecular weight in the range of 1,000 to 150,000; The acrylic resin contains 5 to 33% by weight of the low molecular weight acrylic resin based on the total amount of non-volatile components of the acrylic resin; The spherical fine particles have an average particle diameter in the range of 5 to 15 占 퐉; And the spherical fine particles are contained in an amount of 20 to 50 parts by weight based on 100 parts by weight of the nonvolatile matter of the acrylic resin.

The (meth) acrylic acid-based compound having a structural unit derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms in the high molecular weight acrylic resin and having a content of a structural unit of 70 to 99.8% by weight and having a crosslinkable polar functional group Is in the range of 0.2 to 10% by weight.

The content of the structural unit derived from the (meth) acrylic acid alkyl ester having an alkyl group of 1 to 14 carbon atoms in the low molecular weight acrylic resin is 80 to 100% by weight, and the content of the (meth) acrylic acid- Is 0 to 10% by weight, and the light-diffusing pressure-sensitive adhesive may contain an isocyanate-based cross-linking agent.

(D) Supporting substrate 1e

The support substrate 1e is made of a glass substrate, but may be a plastic substrate. A glass substrate is preferable for attaching a metal film serving as a reflective film on the back side by vapor deposition.

(E) A metal film or metal sheet as the anode electrode (Ea)

It is preferable that the metal film as the anode electrode Ea is formed uniformly in the reflectance unevenness. The thickness of the metal film as the anode electrode Ea formed by vapor deposition is preferably 500 nm or less.

The OLED display device attached to the polarizing film has a configuration in which the? / 4 retardation film 3 is included between the polarizing film 5 and the OLED panel 1 to prevent scattering of the? / 4 retardation film 3 Thereby controlling color non-uniformity.

As described above, the OLED display device of the present embodiment has a reflector, but a uniform color can be realized. In the OLED display device in which the? / 4 retardation film 3 and the polarizing film 5 are bonded on the OLED panel 1, when external light enters, scattering occurs due to light reflected on the surface or inside of the panel do. The color of the reflected light changes due to the above scattering. In addition, the polarization state of reflected light changes so that the reflected light does not have a uniform color, and chrominance non-uniformity (or non-uniformity) occurs in which a difference in color occurs depending on the position. In the case of antireflection, a certain degree of suppression can be achieved by attaching the? / 4 retardation film and the polarizing film.

The apparatus for measuring color has a spectrocolorimeter, and a typical spectrocolorimeter has a color in the visible region of 380 to 780 nm according to the standard observation conditions of CIE (Commission Internationale de l'Eclairage or International Lighting Commission) , XYZ, Yxy, L ^* a ^* b ^* , L ^* C ^* h ^* , ΔE ^* _ab , and wavelength reflectance. L ^* is the brightness index, and a ^* and b ^* are the chromaticness indexes. Among these parameters, the luminous reflectance (or the tristimulus value Y of the object) for the CIE 1931 standard observer is selected as the numerical value related to the color non-uniformity caused by the reflection, and the measurement mode for measuring the luminous reflectance is applied, We have established a relationship. Measurement of luminous reflectance was performed based on international standards such as CIE, ISO, ASTM, DIN, and JIS.

Specifically, it was measured under observation conditions indicated by d / 8: i and d / 8: e. The d / 8: i measurement condition indicates the SCI (Specular Component Included) mode, and the d / 8: e measurement condition indicates the SCE (Specular Component Excluded) mode. The SCI mode and the SCE mode can be measured in different ways depending on whether the specular component is included or not.

When the specular component is high, the color of the object can not be recognized by the human eye because it is very bright. Since the scattered reflection component is darker than the regular reflection component, it is easy to recognize the color of the object with eyes. This means that if the surface condition of an object changes, the color of the object looks different, but the color of the object does not change. The amount of reflection and the amount of scattered reflection are influenced by the surface condition of the object. However, if the object has a uniform color, the total reflection amount does not change. With this, in the SCE mode, only the scattered reflected light is measured except for the specular reflection component, and the SCI mode measures the specular reflected light and scattered reflected light. That is, the SCE mode evaluates the color from the viewpoint of the observer viewing the color of the object. By using the SCI mode, the influence of the surface state can be suppressed and the color can be evaluated.

Hereinafter, preferred embodiments are shown to facilitate understanding of the present invention, but the present invention is not limited thereto.

<Experimental Example>

(1) Fabrication of Scattering Reflector

First, a mirror in which a metal film made of aluminum is deposited on the back surface of a glass substrate is prepared. Alternatively, a metal such as silver may be deposited instead of aluminum to produce a metal film. The glass substrate is a square having a thickness of 3 mm and a size of 295 mm x 295 mm. In the examples, a pressure-sensitive adhesive containing scattering particles (manufactured by Sumitomo Chemical Co., Ltd.) was coated on the surface opposite to the surface on which the metal film was formed on the glass substrate to a thickness of 25 μm or less to prepare a scattering reflector (Reflectors No.1, No.2 and No.3). Further, the light-diffusing pressure-sensitive adhesive scatters and diffuses the transmitted light. With respect to this light-diffusing pressure-sensitive adhesive, with reference to the light-diffusing pressure-sensitive adhesive (composition) described in International Publication WO2012 / 173066, a pressure-sensitive adhesive having each haze value can be used.

As another embodiment, in order to use a reflector having no scattering, a mirror is prepared by depositing an aluminum thin film on a glass substrate in the same manner as described above. On the surface opposite to the deposition surface, A conventional adhesive agent (manufactured by Sumitomo Chemical Co., Ltd.) was applied to a thickness of 25 탆 or less to prepare a reflector (reflectors No. 4, No. 8, No. 9, No. 10, No. 11, No. 14, No. 4). 15).

Further, a metal film made of aluminum is deposited on the rough surface of the substrate of soda-lime glass which is roughened appropriately on one side by sandblasting, and on the surface opposite to the metal film deposition surface, A conventional adhesive was applied to prepare a scattering reflector (reflectors No. 5, No. 6, No. 7, No. 12, No. 13).

The haze value (Haze) of the light-diffusing pressure-sensitive adhesive used in the production of the reflectors Nos. 1, 2 and 3 was measured. For measurement of the haze value, HM-150 (Hayes meter manufactured by Murakami Color Pick) was used. The haze value (Haze) = Td / Tt is the ratio of the scattered transmitted light Td in the total transmitted light Tt. The haze value of the diffusible pressure-sensitive adhesive is determined in accordance with JIS K 7136: 2000 &quot; Method for determining haze of plastic-transparent material &quot;. In all experiments, the temperature at the time of measurement was 25 占 폚 and the humidity was 60%.

The above results are summarized as follows.

(No. 1)

Material of substrate: glass

Material of metal thin film: aluminum

Types of Adhesive: Light-diffusing Adhesive ( ^* 1)

Haze value of the pressure-sensitive adhesive: 27%

(No. 2)

Material of substrate: glass

Material of metal thin film: aluminum

Types of Adhesive: Light-diffusing Adhesive ( ^* 2)

Haze value of the pressure-sensitive adhesive: 34%

(No. 3)

Material of substrate: glass

Material of metal thin film: aluminum

Types of Adhesive: Light-diffusing Adhesive ( ^* 3)

Haze value of the pressure-sensitive adhesive: 52%

(No. 4), (No. 8), (No. 9), (No. 10), (No. 11), (No. 14), (No. 15)

Material of substrate: glass

Material of metal thin film: aluminum

Types of Adhesive: Conventional Adhesive ( ^* 4)

Haze value of the pressure-sensitive adhesive: 0.1%

(No. 5), (No. 6), (No. 7), (No. 12), (No. 13)

Substrate material: Soda lime glass

Material of metal sheet: aluminum

Types of Adhesive: Conventional Adhesive ( ^* 5)

Haze value of the pressure-sensitive adhesive: 0.1%

(2) Evaluation of color non-uniformity

On the scattering reflector, the? / 4 retardation film and the polarizing film were attached in this order. The sample number should be the same as the sample number of each scattering reflector. Namely, since the scattering reflector has the above-described pressure-sensitive adhesive (referred to as a first pressure-sensitive adhesive) on the surface thereof, the? / 4 retardation film is pasted thereon and the pressure- ), And a polarizing film was pasted on the pressure-sensitive adhesive. Further, the member on the side to which the pressure-sensitive adhesive is applied may be a member opposite to these cases. As described above, in this example, the step of attaching the? / 4 phase difference film on the OLED panel and the step of attaching the polarizing film on the? / 4 phase difference film are performed. By reciprocating, it is shielded by the polarizing film, and the emission of reflected light is suppressed.

The second pressure-sensitive adhesive is a conventional pressure-sensitive adhesive (manufactured by Sumitomo Chemical Co., Ltd.) containing no scattering particles and is the same as the above-mentioned conventional pressure-sensitive adhesive ( ^* 4).

After that, the visibility of the color non-uniformity was visually observed under a fluorescent lamp in a dark room. In order to obtain a uniform color photograph, a photograph was taken with a CCD camera (Risa-Color (Hi-Land)) under a fluorescent lamp in a dark room. Fig. 4 shows a photograph of a photograph of a surface taken using samples No. 1 to No. 5.

In the case of sample No. 1, the color non-uniformity observed with the naked eye was "GOOD". In the case of sample No. 2, the color non-uniformity observed with naked eyes was "GOOD". In the case of sample No. 3, the color non-uniformity observed with the naked eye was "NOT BAD". In the case of sample No. 4, the color non-uniformity observed with the naked eye was "VERY GOOD". In the case of sample No. 5, the color unevenness observed with naked eyes was "BAD". The summary of the results is shown in Fig.

The index of the color nonuniformity observed with the naked eye was set as follows.

"VERY GOOD": Unevenness is not completely visible to the naked eye.

"GOOD": Unevenness can not be seen with the naked eye.

"NOT BAD": There is some unevenness in the naked eye.

"BAD": Unevenness is seen visually

(3) Selection of related parameters of reflector

the reflectance r _SCE of the scattering reflector in the mode of _SCE and the reflectance r _SCI in the SCI mode were measured before mounting the? / 4 retardation film and the polarizing film. This luminous reflectance was measured using a spectral colorimeter (CM3700D: manufactured by Konica Minolta) under the conditions of a D65 standard light or a 2-degree observer. The SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) of each sample is shown. The summary of the results is shown in Figs. 5 to 7. Fig.

(SCE / SCI measurement result)

In the case of No. 1 sample, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 33% &quot;.

In the case of No. 2 sample, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 44% &quot;.

In the case of No. 3 sample, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 61% &quot;.

In the case of sample No. 4, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was "0%".

In the case of sample No. 5, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 88% &quot;.

For the sample No. 6, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 56% &quot;.

In the case of No. 7 sample, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 52% &quot;.

In the case of the sample No. 8, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was "0%".

In the case of Sample No. 9, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was "0%".

In the case of Sample No. 10, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was "0%".

In the case of sample No. 11, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 0% &quot;.

In the case of sample No. 12, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 67.87% &quot;.

In the case of the sample No. 13, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was &quot; 70% &quot;.

In the case of the sample No. 14, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was "0%".

In the case of No. 15 sample, the SCE mode reflectance / SCI mode reflectance (r _SCE / r _SCI ) was "0%".

The summary of the results is shown in Figs. 5 to 7. Fig.

(4) Selection of related parameters of OLED display

the reflectance in the SCE mode and the reflectance in the SCI mode of the scattering reflector after mounting the? / 4 retardation film and the polarizing film were measured. This luminous reflectance was measured using a spectral colorimeter (CM3700D: manufactured by Konica Minolta) under the conditions of a D65 standard light or a 2-degree observer. SCE / SCI of each sample is shown.

(SCE / SCI measurement result)

In the case of the sample No. 1, the reflectance R _SCE in the SCE mode was "0.54%" and the reflectance in the SCE mode / SCI mode (R _SCE / R _SCI ) was "9%".

In the case of sample No. 2, the reflectance R _SCE in the SCE mode was 0.66%, and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was 11%.

In the case of sample No. 3, the reflectance R _SCE in the SCE mode was 0.90% and the reflectance in the SCE mode / SCI mode (R _SCE / R _SCI ) was 15%.

In the case of sample No. 4, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

In the case of sample No. 5, the reflectance R _SCE in the SCE mode was 1.34% and the reflectance in the SCE mode / SCI mode (R _SCE / R _SCI ) was 22%.

In the case of Sample No. 6, the reflectance R _SCE in the SCE mode was "1.0%" and the reflectance in the SCE mode / SCI mode (R _SCE / R _SCI ) was "17%".

In the case of the sample No. 7, the reflectance R _SCE in the SCE mode was "0.89%" and the reflectance in the SCE mode / the SCI mode reflectivity (R _SCE / R _SCI ) was "15%".

In the case of the sample No. 8, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

In the case of the sample No. 9, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

In the case of Sample No. 10, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

In the case of the sample No. 11, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

In the case of sample No. 12, the reflectance R _SCE in the SCE mode was "1.1%" and the reflectance in the SCE mode / SCI mode (R _SCE / R _SCI ) was "18.32%".

In the case of the sample No. 13, the reflectance R _SCE in the SCE mode was 1.16% and the reflectance in the SCE mode / SCI mode (R _SCE / R _SCI ) was 19.09%.

In the case of the sample No. 14, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

In the case of the sample No. 15, the reflectance R _SCE in the SCE mode was "0.03%" and the reflectance in the SCE mode / the SCI mode reflectance R _SCE / R _SCI was "1%".

That is, the samples No. 1, No. 2, No. 4, No. 8 to No. 11, No. 14, No. 15 and "NOT" BAD &quot; is obtained in the case of Sample Nos. 3, 6, No.12 and No.13.

The materials of the respective elements used in the above-described Experimental Examples (Examples and Comparative Examples) will be described.

The detailed materials of each element constituting the scattering reflector are as follows.

(1) Glass substrate

The glass substrate is obtained by mixing and melting silica sand (SiO ₂ ), boron oxide (B ₂ O ₃ ), and aluminum oxide (Al ₂ O ₃ ). Here, a commercially available glass substrate (refractive index: 1.50) was used.

(2) Metal film (aluminum)

The film thickness of the metal film formed by vapor deposition was 500 nm. The reflectance of the glass substrate on which the metal film was formed was 88.5%.

(3) Light diffusing adhesive

Was prepared in accordance with International Publication No. WO2012 / 173066.

(3-1) Details of the light-diffusing pressure-sensitive adhesive ( ^* 1) described above:

Specifically, the material used in the above-described Experimental Example contains 23 parts by weight of spherical fine particles (refractive index: 1.49, average diameter: 5 占 퐉) relative to 100 parts by weight of nonvolatile matter of acrylic resin (refractive index: 1.42). The thickness of the diffusion adhesive is 15 占 퐉.

(3-2) Details of the light-diffusing pressure-sensitive adhesive ( ^* 2) described above:

Specifically, 28 parts by weight of spherical fine particles (refractive index: 1.49, average diameter: 5 占 퐉) is contained in 100 parts by weight of nonvolatile matter of acrylic resin (refractive index: 1.42). The thickness of the diffusion adhesive is 15 占 퐉.

(3-3) Details of the light-diffusing pressure-sensitive adhesive ( ^* 3) described above:

Specifically, the material used in the above-described Experimental Example contains 41 parts by weight of spherical fine particles (refractive index: 1.49, average diameter: 5 占 퐉) relative to 100 parts by weight of nonvolatile matter of acrylic resin (refractive index: 1.42). The thickness of the diffusion adhesive is 15 占 퐉.

(4) Details of ordinary pressure-sensitive adhesive:

Material of conventional pressure-sensitive adhesive ^(* 4) used in the above-described experimental example, specifically, will from a light-diffusing pressure-sensitive adhesive ⁽¹⁾ removal of the spherical fine particles, the material, the above-described conventional pressure-sensitive adhesive ^(* 5 ). When the spherical fine particles are 3 parts by weight or less based on 100 parts by weight of the nonvolatile matter of the acrylic resin, it is considered that the same effect is obtained.

(5) Soda lime glass substrate

Soda lime glass is obtained by mixing and melting silica sand (SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ), and calcium carbonate (CaCO ₃ ). Specifically, the refractive index is 1.52, and the surface of one side is sandblasted, and when the metal film is deposited to 500 nm, the SCE reflectance becomes 70.07%.

(6)? / 4 retardation film

As a result of measurement of the? / 4 retardation film by AXOSCAN (Axometrics), the in-plane retardation value (Ro) at 550 nm was 144 nm. For the? / 4 retardation film, the wavelength dispersion characteristics (Re (440 nm) / Re (550 nm)) satisfy 0.8 or more and 1.0 or less. That is, with respect to the effective retardation when the light with the wavelength? = 550 nm is transmitted through the? / 4 retardation film, the effective retardation when the light with the wavelength? = 440 nm is transmitted through the? / 4 retardation film The retardation is in the range of 0.8 or more and 1.0 or less.

(7) polarizing film

The polarizing film used in the above-described Experimental Example was 100 占 퐉 thick, but it may be 26 占 퐉 or more and 220 占 퐉 or less. The above polarizing film was measured with a V7100 UV-VIS spectrometer (manufactured by Jasco), and as a result, the unit transmissivity (Ty) was 44.65% and the orthogonal b ^* was -9.19. The polarizing film preferably has a simple transmittance (Ty) of 40% or more and 44.95% or less and an orthogonal b ^* of -15 or more and 0 or less.

(Results and Interpretation)

First, when the OLED display device has the OLED panel, the? / 4 retardation film pasted on the OLED panel, and the polarizing film pasted on the? / 4 retardation film, the polarization conversion function by the? / 4 retardation film And the light shielding function by the polarizing film, the reflectance is suppressed to be low in principle.

Next, in the OLED display, it is preferable that the reflectance measured in the SCE (Specular Component Excluded) mode at the polarizing film side is 1.2% or less. This is because, when the reflectance is 1.2% or less, evaluation of reflection unevenness is improved as evidenced by the data of Experimental Sample No. 1 and the like. Therefore, it can be seen that the reflection unevenness is improved by the above-mentioned (Expression 1): R _SCE ? 1.2%.

Specifically, the SCE mode reflectivity R _SCE of the sample No. 1 was 0.54%, the SCE mode reflectance R _SCE of the sample No. 2 was 0.66%, the SCE mode reflectance R _SCE of the sample No. 3 was 0.90%, the sample No. 4 of SCE mode _SCE reflectance R is 0.03%, a sample No.5 of the SCE mode _SCE reflectance R is 1.34%, sample No.6 of SCE mode _SCE reflectance R is about 1.0%, of the sample No.7 SCE mode _SCE reflectance R is 0.89 %, sample No.8 of SCE mode _SCE reflectance R is 0.03%, the sample No.9 in SCE mode _SCE reflectance R is 0.03%, mode SCE reflectance of the sample No.10 _SCE R is 0.03%, the samples No.11 SCE The mode reflectance R _SCE is 0.03%, the SCE mode reflectance R _SCE of the sample No. 12 is 1.1%, the SCE mode reflectance R _SCE of the sample No. 13 is 1.16%, the SCE mode reflectance R _SCE of the sample No. 14 is 0.03% The SCE mode reflectance R _SCE of the sample No. 15 is 0.03%.

Therefore, the test samples Nos. 1 to 4 and the test samples No. 6 to No. 15 satisfy R _SCE ? 1.2%. In Experimental Sample No. 13, when R _SCE is 1.16% and rounding down to the second decimal place, R _SCE = 1.2%. In the experimental example, the lower limit of R _SCE is 0.03%.

Next, as evidenced by the data of Experimental Sample Nos. 1 to 4 and No. 6 to No. 15 in the case of (Eq. 2): 0% <R _SCE / R _SCI ≤ 20% Evaluation of reflection unevenness is improved. Also, in the sample No. 13, since R _SCE / R _SCI = 19.09%, it is preferable that R _SCE / R _SCI ≤ 19.1% when the second decimal place is rounded off. Therefore, in the case of (Equation 2), it can be seen that the reflection unevenness is improved. A more preferable range is 0% < R _SCE / R _SCI < 15% as shown in Sample Nos. 1 to 4, 8 to 11, 14 and 15. Further, in the experimental example, the lower limit of R _SCE / R _SCI is 1%.

Similarly, in the case of (formula 3): 0% <r _SCE / r _SCI ? 70%, the test samples No. 1, No. 2, No. 3, No. 6, No. 7, As evidenced by the .13 data, the above evaluation of the reflection unevenness is improved. Therefore, in the case of (Formula 3), it can be seen that the reflection unevenness is improved. A more preferable range is 0% < r _SCE / r _SCI < 60% as shown in Experimental Sample Nos. 1, 2, 6 and 7. In the experimental example, the lower limit of r _SCE / r _SCI is 33%.

Also, it is preferable that the reflectance of the OLED panel 1 measured in the SCE mode measured on the surface of the panel is 61% or less (for example, sample No. 6). In this case, evaluation of the reflection unevenness is improved.

It is preferable that the polarizing film has a simple transmittance (Ty) of 40% to 44.95% and an orthogonal b ^* value of 0 to -15.

As described above, in the OLED display device in which the? / 4 retardation film 3 and the polarizing film 5 are laminated on the OLED panel 1, the reflectance measured in the SCE mode at the surface of the OLED display device Is 1.2% or less, the color non-uniformity of the OLED display device by scattering is adjusted.

One … OLED panels,
3 ... lambda / 4 retardation film,
5 ... Polarizing film,
5a ... Polarizers,
5b, 5c ... Transparent protective film,
10 ... OLED display,
11, 12 ... Adhesive (layer).

Claims (7)

An OLED panel,
A? / 4 retardation film pasted on the OLED panel,
And a polarizing film pasted on the? / 4 retardation film,
In this state, the reflectance measured in the SCE (Specular Component Excluded) mode at the polarizing film side is 1.2% or less,
The b ^* value of the polarizing film is not less than -15 and not more than 0,
The reflectance r _SCE measured in the SCE mode on the surface of the light output side of the OLED panel and the reflectance r r measured in the SCI mode on the surface side are obtained by removing the? / 4 retardation film and the polarizing film, The ratio of _SCI r _SCE / r _SCI ,
The following relationship:
33% ≤ r _SCE / r _SCI ≤ 44%
Lt; RTI ID = 0.0 &gt; OLED. &Lt; / RTI &gt; The method according to claim 1,
A first pressure-sensitive adhesive interposed between the OLED panel and the? / 4 retardation film;
And a second pressure-sensitive adhesive interposed between the? / 4 retardation film and the polarizing film. 3. The method of claim 2,
Wherein the first pressure sensitive adhesive and the second pressure sensitive adhesive both contain an acrylic resin. An OLED panel,
A? / 4 retardation film pasted on the OLED panel,
And a polarizing film pasted on the? / 4 retardation film,
In this state, the ratio R _SCE / R _SCI of the reflectance R _SCE measured in the SCE (Specular Component Excluded) mode on the polarizing film side and the reflectance R _SCI measured in the SCI (Specular Component Included) mode on the polarizing film side,
The following relationship:
0% < R _SCE / R _SCI &lt; 20%
Lt; / RTI &gt;
The b ^* value of the polarizing film is not less than -15 and not more than 0,
The reflectance r _SCE measured in the SCE mode on the surface of the light output side of the OLED panel and the reflectance r r measured in the SCI mode on the surface side are obtained by removing the? / 4 retardation film and the polarizing film, The ratio of _SCI r _SCE / r _SCI ,
The following relationship:
33% ≤ r _SCE / r _SCI ≤ 44%
Lt; RTI ID = 0.0 &gt; OLED. &Lt; / RTI &gt; delete An OLED panel,
A? / 4 retardation film pasted on the OLED panel,
And a polarizing film pasted on the? / 4 retardation film,
In this state, a method of manufacturing an OLED display device having a reflectance measured in a SCE (Specular Component Excluded) mode at a polarizing film side of 1.2% or less,
A step of attaching a? / 4 retardation film on the OLED panel,
And a step of attaching a polarizing film on the? / 4 retardation film,
The b ^* value of the polarizing film is not less than -15 and not more than 0,
The reflectance r _SCE measured in the SCE mode on the surface of the light output side of the OLED panel and the reflectance r r measured in the SCI mode on the surface side are obtained by removing the? / 4 retardation film and the polarizing film, The ratio of _SCI r _SCE / r _SCI ,
The following relationship:
33% ≤ r _SCE / r _SCI ≤ 44%
Of the first electrode layer. An OLED panel,
A? / 4 retardation film pasted on the OLED panel,
And a polarizing film pasted on the? / 4 retardation film,
In this state, a method of manufacturing an OLED display device having a reflectance measured in a SCE (Specular Component Excluded) mode at a polarizing film side of 1.2%
A step of attaching a? / 4 retardation film on a polarizing film to produce a circularly polarizing plate,
And a step of pasting the circular polarizer on the OLED panel,
The b ^* value of the polarizing film is not less than -15 and not more than 0,
The reflectance r _SCE measured in the SCE mode on the surface of the light output side of the OLED panel and the reflectance r r measured in the SCI mode on the surface side are obtained by removing the? / 4 retardation film and the polarizing film, The ratio of _SCI r _SCE / r _SCI ,
The following relationship:
33% ≤ r _SCE / r _SCI ≤ 44%
Of the first electrode layer.

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