JP4157539B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device excellent in display quality.

In recent years, a color liquid crystal display device has attracted attention as a flat display. As an example of a color liquid crystal display device, a black matrix, a colored layer composed of a plurality of colors (usually three primary colors of red (R), green (G), and blue (B)), a common transparent electrode layer, and an alignment layer are provided. A transmissive liquid crystal in which a color filter and a counter electrode substrate including a thin film transistor (TFT element), a pixel electrode, and an alignment layer face each other with a predetermined gap and a liquid crystal material is injected into the gap to form a liquid crystal layer. There is a display device. There is also a reflective liquid crystal display device in which a reflective layer is provided between the color filter substrate and the colored layer.
In such a color liquid crystal display device, when the alignment state of the liquid crystal changes due to a liquid crystal alignment failure, a voltage change applied to the liquid crystal, a voltage variation in the display surface, or the like, a display failure occurs. This display defect includes the following image sticking and white unevenness.

Image sticking occurs when the voltage is lowered or turned off after a voltage is applied to the same pixel for a certain period of time, so that the transmittance of this pixel differs from the transmittance of the surrounding pixels for which the voltage was not applied for a certain period of time. This is a phenomenon in which the uneven state is recognized, and the uneven state continues even after being left for a long time. In a burn-in phenomenon in a normally white panel, a pixel to which a voltage is applied for a certain time appears darker than surrounding pixels. Such seizure phenomenon is caused by the fact that the ionic substance adheres to the electrode during voltage application, and the ionic substance remains adsorbed on the electrode even if the voltage is released next, and the voltage due to this ionic substance is liquid crystal. This is thought to be due to the fact that it continues to act.
Further, the white unevenness is a phenomenon in which the uneven state is recognized because a part of the display area does not become zero transmittance when a black screen is displayed by applying a voltage. This is because the voltage applied between the electrodes should be kept constant, but if there is an ionic substance in the liquid crystal, the ionic substance moves, that is, the current flows, so the voltage between the electrodes The cause is thought to be descending.

It is considered that the ionic substance that causes the display defect phenomenon as described above does not stay on the electrode but easily moves in the liquid crystal layer. Various sources can be considered as the source of this ionic substance. In order to prevent display defects, impurities from chemicals, air, pure water, etc. used in the manufacturing process, management from equipment, human bodies, etc. Dust generation management and process conditions are optimized. Also, impurities such as residue are removed by cleaning the surface of the color filter and the counter electrode substrate, and by irradiating with ultraviolet rays and polishing the surface in the manufacturing process.
Although such a response makes it difficult for the display failure phenomenon to occur, there is a problem that the probability of the display failure is still high under severe display conditions such as long-time display and high temperature and high humidity.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal display device capable of preventing the mixing of an ionic substance into a liquid crystal layer and ensuring high quality display. To do.

The present invention considers a resin member that is in contact with the liquid crystal layer of a liquid crystal display device as one of the sources of the ionic substance as described above, and has a correlation with a display defect due to the ionic substance transferred from the resin member into the liquid crystal layer. As a characteristic, attention is paid to the voltage holding ratio and the residual DC (ΔE) of the liquid crystal subjected to the impurity extraction process from the resin member.
That is, in order to achieve the above object, the present invention provides a common electrode substrate and a counter electrode substrate that face each other so as to provide a gap portion through a seal member, and a liquid crystal layer sealed in the gap portion. The common electrode substrate has a common transparent electrode layer on the substrate, the counter electrode substrate has a semiconductor driving element, a resin light-shielding layer formed on each semiconductor driving element, and a predetermined pattern corresponding to each semiconductor driving element In the method of manufacturing a liquid crystal display device comprising a plurality of resin-colored layers formed of a liquid crystal having a voltage holding ratio of 95% or more and a residual DC (ΔE) of 0.05 V or less, As the resin member, a resin member is selected that has a voltage holding ratio of 80% or more and a residual DC (ΔE) of 0.5 V or less after being subjected to impurity extraction treatment by being immersed in the liquid crystal. And the resin member The resin light-shielding layer and the resin-colored layer are formed using

The present invention also includes a color filter and a counter electrode substrate facing each other so as to provide a gap portion through a seal member, and a liquid crystal layer sealed in the gap portion, and the color filter is formed on the substrate and the substrate. In a method of manufacturing a liquid crystal display device comprising a reflective layer, a resin colored layer composed of a plurality of colors, and a common transparent electrode layer , a voltage holding ratio of 95% or more and a residual DC (ΔE) of 0.05 V The following liquid crystal is prepared, and as a resin member, the voltage holding ratio of the liquid crystal after being immersed in the liquid crystal and subjected to the impurity extraction treatment is 80% or more and the residual DC (ΔE) is 0.5 V or less. Such a resin member is selected, and the resin colored layer is formed using the resin member .

Furthermore, the present invention includes a common electrode substrate and the counter electrode substrate opposite to each other to provide a gap via a sealing member, and a liquid crystal layer sealed in the gap, to the common electrode substrate on the substrate a common transparent electrode layer, the counter electrode substrate driving element layer were sequentially stacked on a substrate and the substrate, the reflective electrode layer, in the manufacturing method of the liquid crystal display device provided with a composed of a plurality of colors resin colored layer, the voltage holding A liquid crystal having a ratio of 95% or more and a residual DC (ΔE) of 0.05 V or less is prepared, and the voltage holding ratio of the liquid crystal after being subjected to an impurity extraction treatment by being immersed in the liquid crystal as a resin member Is 80% or more and the residual DC (ΔE) is selected to be 0.5 V or less, and the resin colored layer is formed using the resin member .

  According to the present invention, the resin member that is in contact with the liquid crystal layer in the liquid crystal display device or that is closest to the liquid crystal layer through the thin film is subjected to an impurity extraction treatment from the resin member and the voltage holding ratio of the liquid crystal Resin member with residual DC (ΔE) within the specified range prevents display defects such as burn-in and white unevenness even under severe display conditions such as long-time display and high temperature and high humidity. Thus, a liquid crystal display device having excellent display quality is possible.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic sectional view showing an embodiment of the liquid crystal display device of the present invention. In FIG. 1, a liquid crystal display device 401 has a counter electrode substrate 411 and a common electrode substrate 431 facing each other at a predetermined interval, a peripheral portion is sealed with a seal member (not shown), and a liquid crystal layer 405 is formed in the gap portion. It is formed. Although not shown, polarizing plates are disposed outside the counter electrode substrate 411 and the common electrode substrate 431, respectively.

The counter electrode substrate 411 constituting the liquid crystal display device 401 of the present invention includes a semiconductor driving element 420 integrally formed on the transparent substrate 412, a transparent pixel electrode 413, and a resin light-shielding formed on the semiconductor driving element 420. A layer 414, a resin colored layer 415 formed on the transparent pixel electrode 413, and an alignment layer 416 formed to cover the transparent pixel electrode 413, the resin light shielding layer 414, the resin colored layer 415, and the semiconductor driving element 420. Yes.
The semiconductor driving element 420 is a thin film transistor (TFT) including a gate electrode 421, a gate insulating film 422, a semiconductor layer 423 such as amorphous silicon, a source electrode 424, and a drain electrode 425. The drain electrode 425 has one end connected to the semiconductor layer 423 and the other end connected to the pixel electrode 413.

The resin light-shielding layer 414 is formed on the source electrode 424 and the drain electrode 425 so as to shield the semiconductor layer 423, and functions to suppress the light leakage current of the semiconductor driving element 420. The resin light-shielding layer 414 is a resin member that is in contact with the liquid crystal layer 405 via the alignment layer 416 in the liquid crystal display device 401. In the present invention, the resin light-shielding layer 414 is a liquid crystal layer subjected to impurity extraction treatment. The voltage holding ratio is 80% or more, preferably 90% or more, more preferably 95% or more, and the residual DC (ΔE) is 0.5 V or less, preferably 0.2 V or less, more preferably 0. .1V or less.
In the present invention, the resin member that is in contact with the liquid crystal layer of the liquid crystal display device is considered as one of the sources of impurities such as ionic substances, and as a characteristic that correlates with display defects due to impurities transferred from the resin member into the liquid crystal layer, We paid attention to the voltage holding ratio and residual DC (ΔE) of the liquid crystal subjected to the impurity extraction treatment from the resin member.

  That is, in order to prevent white unevenness, which is one of display defects, it is necessary to maintain the voltage applied between the electrodes located on both sides of the liquid crystal layer. In the present invention, the resin light-shielding layer 414, As will be described later, the resin coloring layer 415 is defined such that the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment is 80% or more, preferably 90% or more, more preferably 95% or more. In order to prevent image sticking, which is one of display defects, an unnecessary voltage continues to be applied to the liquid crystal layer when the residual DC (ΔE) is reduced as much as possible and the voltage applied to the liquid crystal layer is released. It is necessary to prevent this. In the present invention, the residual DC (ΔE) of the liquid crystal obtained by subjecting the resin light-shielding layer 414 and the resin coloring layer 415 to the impurity extraction treatment is 0.5 V or less, preferably 0.2 V or less, more preferably 0.1 V or less. It prescribes. Thereby, even under severe display conditions such as long-time display and high temperature and high humidity, display defects such as image sticking and white unevenness can be prevented, and a liquid crystal display device with excellent display quality can be achieved.

Here, the impurity extraction process, the measurement condition of the voltage holding ratio, and the measurement condition of the residual DC (ΔE) will be described.
(Impurity extraction process)
A resin member having a surface area of 4 cm ² is immersed in a liquid crystal having a volume of 0.2 ml and extracted at a temperature of 105 ° C. for 5 hours. In addition, the liquid crystal to be used has a voltage holding ratio of 95% or more measured under the following voltage holding ratio measuring conditions in the state before the impurity extraction treatment, and a residual measured under the following residual DC (ΔE) measuring conditions. A liquid crystal having a DC (ΔE) of 0.05 V or less is used.

(Voltage holding ratio measurement conditions)
As a layer structure, a measurement cell comprising a substrate / electrode / alignment layer / liquid crystal / alignment layer / electrode / substrate is prepared, and liquid crystal subjected to impurity extraction treatment is injected and measured under the following conditions.
・ Distance between electrodes: 5 to 15 μm
・ Applied voltage pulse amplitude: 5V
・ Applied voltage pulse frequency: 60 Hz
・ Applied voltage pulse width: 16.67 msec

(Residual DC (ΔE) measurement conditions)
In the voltage-capacitance hysteresis loop illustrated in FIG. 2, the residual DC (ΔE) is an electrostatic capacity defined by the formula (C0 + Cs) / 2 from the maximum capacitance (Cs) and the minimum capacitance (C0). This is a voltage shift amount in the capacitor (indicated by an arrow in FIG. 2). For the measurement, a measurement cell comprising a substrate / electrode / alignment layer / liquid crystal / alignment layer / electrode / substrate is prepared as a layer structure, and the liquid crystal subjected to the impurity extraction treatment is injected and measured under the following conditions.
・ Distance between electrodes: 5 to 15 μm
Liquid crystal used: Capacitance saturation voltage (Vs ′ in FIG. 2) is 10V
・ Voltage-Capacitance hysteresis loop measurement voltage range: -10V to + 10V

The resin light-shielding layer 414 is formed by forming a photosensitive resin layer containing insulating light-shielding particles such as Cu—Fe—Mn composite oxide, and patterning the photosensitive resin layer. Or any of them.
The resin coloring layer 415 of the counter electrode substrate 411 is formed so as to cover each transparent pixel electrode 413, and a red pattern 415R, a green pattern 415G, and a blue pattern (not shown) are formed in a desired pattern shape for each pixel electrode. ing. The resin coloring layer 415 can be formed by a pigment dispersion method using a photosensitive resin containing a desired colorant, and can be formed by a known method such as a printing method or a transfer method. Further, for example, the resin coloring layer 415 may have an optimum liquid crystal layer thickness for each color by making the red pattern the thinnest and then increasing the thickness in the order of the green pattern and the blue pattern.

In the liquid crystal display device 401 of the present invention, as described above, the resin coloring layer 415 has a voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment of 80% or more and a residual DC (ΔE) of 0.5 V or less. To do. In order to provide the resin coloring layer 415 with such characteristics (voltage holding ratio of liquid crystal subjected to impurity extraction treatment is 80% or more and residual DC (ΔE) is 0.5 V or less), an acrylic copolymer or the like is used. Resin materials can be used.
As the transparent substrate 412 constituting the counter electrode substrate 411, a non-flexible transparent rigid material such as quartz glass, pyrex glass and synthetic quartz plate, or a flexible resin material such as a transparent resin film and an optical resin plate is used. The transparent flexible material which has can be used. Among them, Corning 7059 glass is a material having a small coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the active matrix. Suitable for color liquid crystal display devices.

On the other hand, in the common electrode substrate 431 constituting the liquid crystal display device 401 of the present invention, the common transparent electrode 433 and the alignment layer 434 are formed on the transparent substrate 432. As the transparent substrate 432, those described as the transparent substrate 412 can be used.
Further, the transparent pixel electrode 413 and the common transparent electrode layer 433 constituting the liquid crystal display device 401 are made of indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or an alloy thereof. The film is formed by a general film forming method such as sputtering, vacuum deposition, or CVD. The thickness of such an electrode layer is about 0.01 to 1 μm, and an effect of shielding impurities can hardly be expected.

  Furthermore, the alignment layers 416 and 434 constituting the liquid crystal display device 401 can be formed of an organic compound such as polyimide, polyamide, polyurethane, or polyurea, and the thickness is about 0.01 to 1 μm. Can do. Such alignment layers 416 and 434 are coated by various printing methods and known coating methods, and then fired and then subjected to alignment treatment (rubbing). Since the alignment layers 416 and 434 made of such an organic compound have a very small thickness, it is not necessary to consider the mixing of impurities into the liquid crystal layer 405 that causes display defects. Such alignment layers 416 and 434 can hardly be expected to act to shield impurities.

The liquid crystal layer 405 constituting the liquid crystal display device 401 has a voltage holding ratio of 95% or more measured under the voltage holding ratio measuring condition as described above in the state before the impurity extraction process, and the above-described It can be formed using a liquid crystal having a residual DC (ΔE) measured under a residual DC (ΔE) measurement condition of 0.05 V or less.
In the liquid crystal display device 401 of the present invention as described above, the resin member located at the position in direct contact with the liquid crystal layer 405 or the nearest part of the liquid crystal layer 405 through a thin film such as an alignment layer or a transparent electrode is opposed to Only the resin light shielding layer 414 and the resin coloring layer 415 of the electrode substrate 411 are provided. The resin light-shielding layer 414 and the resin coloring layer 415 make the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment 80% or more, preferably 90% or more, more preferably 95% or more, as described above. And the residual DC (ΔE) is 0.5 V or less, preferably 0.2 V or less, more preferably 0.1 V or less. As a result, the liquid crystal display device 401 has excellent display quality by preventing the occurrence of display defects such as image sticking and white unevenness even under severe display conditions such as long-time display and high temperature and high humidity. .

[Second Embodiment]
FIG. 3 is a schematic sectional view showing another embodiment of the liquid crystal display device of the present invention. In FIG. 3, a liquid crystal display device 501 is a reflective liquid crystal display device, in which a color filter 11 ′ and a counter electrode substrate 511 are opposed to each other at a predetermined interval, and a peripheral portion is sealed with a seal member (not shown). The liquid crystal layer 505 is formed in the gap portion. Although not shown, a retardation plate and a polarizing plate are disposed outside the counter electrode substrate 511 on the viewer side.
The color filter 11 ′ constituting the liquid crystal display device 501 of the present invention has a predetermined pattern so as to cover the substrate 12, the reflective layer 17, the black matrix 14 ′ formed on the reflective layer 17, and the black matrix 14 ′. And a colored resin layer 15 'composed of a plurality of colors. In the liquid crystal display device 501 of the present invention, the resin coloring layer 15 ′ constituting the color filter 11 ′ has the above-described characteristics (the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment is 80% or more and the residual DC ( ΔE) is 0.5 V or less).

  The substrate 12 constituting the color filter 11 has flexibility such as a transparent rigid material such as quartz glass, pyrex glass, and synthetic quartz plate, or a transparent resin film or an optical resin plate. A transparent flexible material can be used. Among them, Corning 7059 glass is a material having a small coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the active matrix. Suitable for color filters for color liquid crystal display devices.

The black matrix 14 ′ of the color filter 11 ′ is formed by forming a resin layer containing light-shielding particles such as carbon fine particles and patterning the resin layer, and light-shielding carbon fine particles and metal oxides. Any of those formed by forming a photosensitive resin layer containing photosensitive particles and patterning the photosensitive resin layer may be used.
In the present invention, the color filter 11 ′ may not include the black matrix 14 ′. In this case, the substrate 12 may be exposed at a portion where the resin coloring layer 15 ′ is not formed, or the resin coloring layer 15 ′ may be formed so as to cover the substrate 12.

  The resin colored layer 15 'of the color filter 11' has a red pattern 15'R, a green pattern 15'G and a blue pattern 15'B arranged in a desired pattern shape, and a photosensitive material containing a desired colorant. It can be formed by a pigment dispersion method using a functional resin, and can also be formed by a known method such as a printing method or a transfer method. Further, the resin colored layer 15 'is, for example, the thinnest red pattern 15'R, and thickened in the order of the green pattern 15'G and the blue pattern 15'B, so that an optimum liquid crystal for each color of the resin colored layer 15' is obtained. The layer thickness may be set. In order to provide the resin coloring layer 15 ′ with the above-described characteristics (the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment is 80% or more and the residual DC (ΔE) is 0.5 V or less), an acrylic copolymer Etc. can be used.

The reflective layer 17 constituting the color filter 11 'can be formed by forming a metal thin film such as aluminum by a known film forming means such as a vapor deposition method or a sputtering method.
A common transparent electrode layer 506 for driving liquid crystal and an alignment layer 507 are formed on the resin colored layer 15 'of the color filter 11'.
On the other hand, a counter electrode substrate 511 constituting the liquid crystal display device 501 of the present invention includes a transparent pixel electrode 513 and a thin film transistor (TFT) 514 for driving liquid crystal on a transparent substrate 512, and an alignment layer covering the transparent pixel electrode 513. 515 is formed. The counter electrode substrate 511 includes a gate line group (not shown) for opening and closing a thin film transistor (TFT) 514, a signal line group (not shown) for supplying a video signal, and a common transparent electrode on the color filter 11 'side. A voltage supply line (not shown) to the layer 506 is provided. These lead wires are usually made of a metal such as aluminum formed in a lump in the manufacturing process of the thin film transistor (TFT) 514.

As the transparent substrate 512 constituting the counter electrode substrate 511, those described for the transparent substrate 412 can be used.
The common transparent electrode layer 506 and the transparent pixel electrode layer 513 constituting the liquid crystal display device 501 are made of indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or an alloy thereof. The film is formed by a general film formation method such as sputtering, vacuum deposition, or CVD. The thickness of such an electrode layer is about 0.01 to 1 μm, and an effect of shielding impurities can hardly be expected.

Furthermore, the alignment layers 507 and 515 constituting the liquid crystal display device 501 can be formed of an organic compound such as polyimide, polyamide, polyurethane, or polyurea, and the thickness is about 0.01 to 1 μm. Can do. Such alignment layers 507 and 515 are coated by various printing methods and known coating methods, and then fired and then subjected to alignment treatment (rubbing). Since the alignment layers 507 and 515 made of such an organic compound are extremely small in thickness, it is not necessary to consider the mixing of impurities into the liquid crystal layer 505 that cause display defects. Such alignment layers 107 and 115 are hardly expected to shield impurities.
The liquid crystal layer 505 constituting the liquid crystal display device 501 has a voltage holding ratio of 95% or more measured under the voltage holding ratio measuring condition as described above in the state before the impurity extraction process described above, and as described above. It can be formed using a liquid crystal having a residual DC (ΔE) measured under a residual DC (ΔE) measurement condition of 0.05 V or less.

  In such a liquid crystal display device 501 of the present invention, the resin member located at the position in direct contact with the liquid crystal layer 505 or the nearest part of the liquid crystal layer 505 through a thin film such as an alignment layer or a transparent electrode is colored. Only the resin colored layer 15 'constituting the filter 11'. As described above, the resin-colored layer 15 ′ has a voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment of 80% or more, preferably 90% or more, more preferably 95% or more, and The residual DC (ΔE) is 0.5 V or less, preferably 0.2 V or less, more preferably 0.1 V or less. Accordingly, the liquid crystal display device 501 has excellent display quality by preventing the occurrence of display defects such as image sticking and white unevenness even under severe display conditions such as long-time display and high temperature and high humidity. .

  In the liquid crystal display device 501 described above, the color filter 11 ′ of the present invention provided with a reflective layer is used as the color filter, but the present invention is not limited to this. For example, a color filter in which the black matrix 14 'is exposed at the boundary portion of the red pattern 15'R, the green pattern 15'G, and the blue pattern 15'B constituting the resin coloring layer 15' may be used. In this case, it is necessary to give the black matrix 14 'the above characteristics (the voltage holding ratio of the liquid crystal subjected to the impurity extraction process is 80% or more and the residual DC (ΔE) is 0.5V or less). A resin material such as an acrylic copolymer can be used.

  Further, as the color filter, a color filter in which a transparent resin protective layer is provided so as to cover the resin coloring layer 15 ′ and the black matrix 14 ′ can be used. In this case, the resin protective layer is provided in order to flatten the surface of the color filter and to prevent the components contained in the colored layer from eluting into the liquid crystal layer. Therefore, it is necessary that the resin protective layer has the above-described characteristics (the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment is 80% or more and the residual DC (ΔE) is 0.5 V or less) For that purpose, it can form using resin materials, such as an acrylic copolymer. The thickness of the resin protective layer can be set in consideration of the light transmittance of the material used, the surface state of the color filter, etc., and can be set in the range of 0.1 to 3.0 μm, for example. Even when such a resin protective layer is provided, the above-described characteristics (the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment is 80% or more and the residual DC (ΔE) is 0.5 V or less). The resin coloring layer 15 ′ and the black matrix 14 ′ may be provided.

  Furthermore, a color filter having a plurality of transparent resin columnar protrusions on a predetermined portion of the black matrix 14 'on the resin protective layer as described above may be used. In this case, the resin columnar protrusion functions as a spacer when the color filter is bonded to the counter electrode substrate 511. This resin columnar convex part can be formed, for example, by applying a photosensitive resin paint, exposing, developing and curing in a predetermined pattern. The resin columnar protrusion has a certain height so as to protrude in the range of about 2 to 10 μm from the above resin protective layer, and the protrusion amount depends on the thickness required for the liquid crystal layer of the liquid crystal display device. It can be set appropriately. Further, the formation density of the resin columnar protrusions can be appropriately set in consideration of the thickness unevenness of the liquid crystal layer, the aperture ratio, the shape and material of the resin columnar protrusions, and for example, the red pattern 15′R, green Necessary and sufficient spacer functions are expressed at a ratio of one pattern 15'G and one blue pattern 15'B. The shape of such resin columnar convex portions is not particularly limited, and may be a cylindrical shape, a prismatic shape, a truncated cone shape, or the like. And when using the color filter provided with such a resin columnar convex part, the resin columnar convex part and the protective layer have the above characteristics (the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment is 80%. As described above, the residual DC (ΔE) needs to have 0.5 V or less), and for that purpose, it can be formed using a resin material such as an acrylic copolymer.

[Third Embodiment]
FIG. 4 is a schematic sectional view showing another embodiment of the liquid crystal display device of the present invention. In FIG. 4, a liquid crystal display device 601 is a reflective liquid crystal display device. A counter electrode substrate 611 and a common electrode substrate 621 are opposed to each other at a predetermined interval, and a peripheral portion is sealed with a seal member (not shown). A liquid crystal layer 605 is formed in the gap portion. Although not shown, a retardation plate and a polarizing plate are disposed outside the common electrode substrate 621 on the viewer side.
The counter electrode substrate 611 constituting the liquid crystal display device 601 of the present invention includes a plurality of thin film transistors (TFTs) 613 forming a liquid crystal driving element layer on a substrate 612 and a plurality of reflective pixel electrodes 614 forming a reflective electrode layer. A resin colored layer 615 is formed so as to cover the reflective pixel electrode 614, and an alignment layer 606 is formed so as to cover the reflective pixel electrode 614 and the resin colored layer 615.

The reflective pixel electrode 614 of the counter electrode substrate 611 can be formed by providing a metal thin film such as aluminum by a known film forming means such as a vapor deposition method or a sputtering method and patterning it.
The resin coloring layer 615 of the counter electrode substrate 611 is formed so as to cover each reflective pixel electrode 614, and a red pattern 615R, a green pattern 615G, and a blue pattern 615B are formed in a desired pattern shape for each reflective pixel electrode. The resin coloring layer 615 can be formed by a pigment dispersion method using a photosensitive resin containing a desired colorant, and can be formed by a known method such as a printing method or a transfer method. Further, for example, the resin coloring layer 615 may be set to have an optimal liquid crystal layer thickness for each color by making the red pattern the thinnest and then increasing the thickness in the order of the green pattern and the blue pattern.

In the liquid crystal display device 601, the resin coloring layer 615 has a voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment of 80% or more and a residual DC (ΔE) of 0.5 V or less. Such a colored layer 615 can be formed using a resin material as described in the description of the resin colored layer 415 of the liquid crystal display device 401 described above.
As the substrate 612 constituting the counter electrode substrate 611, those described as the transparent substrate 412 can be used.

On the other hand, in the common electrode substrate 621 constituting the liquid crystal display device 601 of the present invention, the common transparent electrode layer 623 and the alignment layer 624 are formed on the transparent substrate 622. As the transparent substrate 622, those described as the transparent substrate 412 can be used. In addition, the common transparent electrode layer 623 is made of indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), etc., and alloys thereof, etc., such as sputtering, vacuum evaporation, CVD, etc. Formed by a typical film forming method. The thickness of such an electrode layer is about 0.01 to 1 μm, and an effect of shielding impurities can hardly be expected.
Further, the alignment layers 606 and 624 included in the liquid crystal display device 601 can be the same as the alignment layers 416 and 434 included in the liquid crystal display device 401 described above.
The liquid crystal layer 605 constituting the liquid crystal display device 601 has a voltage holding ratio of 95% or more measured under the above-described voltage holding ratio measurement conditions in the state before the impurity extraction process, and the above-described It can be formed using a liquid crystal having a residual DC (ΔE) measured under a residual DC (ΔE) measurement condition of 0.05 V or less.

  In such a liquid crystal display device 601 of the present invention, the resin member located at the position in direct contact with the liquid crystal layer 605 or the nearest part of the liquid crystal layer 605 through a thin film such as an alignment layer or a transparent electrode is opposed to Only the resin coloring layer 615 constituting the electrode substrate 611 is provided. Then, as described above, the resin coloring layer 615 has a voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment of 80% or more, preferably 90% or more, more preferably 95% or more, and The residual DC (ΔE) is 0.5 V or less, preferably 0.2 V or less, more preferably 0.1 V or less. As a result, the liquid crystal display device 601 has excellent display quality by preventing the occurrence of display defects such as image sticking and white unevenness even under severe display conditions such as long-time display and high temperature and high humidity. .

Next, an Example is shown and this invention is demonstrated further in detail.
Impurity extraction treatment test Preparation of sample In order to use for the impurity extraction process, a coating film was formed on a glass substrate (Corning 7059 glass) using various materials used for a color liquid crystal display device as follows.
(1) Black matrix photosensitive paint and colored layer photosensitive paint Black matrix photosensitive paint and colored layer photosensitive paint R1, G1, G2, B1 are dispersion compositions (pigments, dispersants, And a solvent) containing beads, dispersed for 3 hours with a disperser, and then mixed with a dispersion obtained by removing the beads and a clear resist composition (polymer, monomer, additive, disclosure agent and solvent). Yes, its composition is shown below. A paint shaker was used as the disperser.

Next, the prepared black matrix photosensitive paint and colored layer photosensitive paints R1, G1, G2, and B1 were each applied to a glass substrate to a thickness of 1.5 μm by spin coating, 90 ° C., Pre-baked under conditions of 3 minutes, whole surface exposure (500 mJ / cm ² ), spray development using 0.05% KOH aqueous solution for 60 seconds, and then post-baked at 200 ° C. for 30 minutes, glass with a coating film A substrate was produced.
(Photosensitive paint for black matrix)
Black pigment: 14.0 parts by weight (TM Black # 95550 manufactured by Dainichi Seika Kogyo Co., Ltd.)
-Dispersant (Disperbyk 111 manufactured by Big Chemie Co., Ltd.) ... 1.2 parts by weight-Polymer (VR60 manufactured by Showa Polymer Co., Ltd.) ... 2.8 parts by weight-Monomer (SR399 manufactured by Sartomer Co., Ltd.) ... 3.5 weights Parts ・ Additive (L-20, manufactured by Soken Chemical Co., Ltd.) 0.7 parts by weight Initiator 1.6 parts by weight (2-benzyl-2-dimethylamino-1- (4-morpholino)
Phenyl) -butanone-1)
・ Initiator: 0.3 part by weight (4,4′-diethylaminobenzophenone)
Initiator (2,4-diethylthioxanthone) 0.1 part by weight Solvent (ethylene glycol monobutyl ether) 75.8 parts by weight

(Photosensitive paint R1 for red pattern)
・ Red pigment: 4.8 parts by weight (Chromotal Red A2B manufactured by Ciba Geigy)
・ Yellow pigment: 1.2 parts by weight (PASFOL Yellow D1819 manufactured by BASF)
Dispersant (Solsperse 24000 manufactured by Zeneca Corporation) 3.0 parts by weight Monomer (SR399 manufactured by Sartomer Co.) 4.0 parts by weight Polymer 1 5.0 parts by weight Initiator (manufactured by Ciba Geigy) Irgacure 907) 1.4 parts by weight Initiator 0.6 parts by weight (2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

(Photosensitive paint G1 for green pattern)
Green pigment: 4.2 parts by weight (Monestral Green 9Y-C manufactured by Zeneca)
・ Yellow pigment: 1.8 parts by weight (PASFOL Yellow D1819 manufactured by BASF)
Dispersant (Solsperse 24000 manufactured by Zeneca Corporation) 3.0 parts by weight Monomer (SR399 manufactured by Sartomer Co.) 4.0 parts by weight Polymer 1 5.0 parts by weight Initiator (manufactured by Ciba Geigy) Irgacure 907) 1.4 parts by weight Initiator 0.6 parts by weight (2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

(Photosensitive paint G2 for green pattern)
Green pigment: 4.2 parts by weight (Zeneca Co., Ltd. Monastral Green 6Y-CL)
・ Yellow pigment: 1.8 parts by weight (PASFOL Yellow D1819 manufactured by BASF)
Dispersant (Solsperse 24000 manufactured by Zeneca Corporation) 3.0 parts by weight Monomer (SR399 manufactured by Sartomer Co.) 4.0 parts by weight Polymer 1 5.0 parts by weight Initiator (manufactured by Ciba Geigy) Irgacure 907) 1.4 parts by weight Initiator 0.6 parts by weight (2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

(Photosensitive paint B1 for blue pattern)
・ Blue pigment: 6.0 parts by weight (BASF Heliogen Blue L6700F)
-Pigment derivative: 0.6 parts by weight (Solsperse 12000 manufactured by Zeneca)
・ Dispersant (Solsperse 24000 manufactured by Zeneca Corporation) 2.4 parts by weight Monomer (SR399 manufactured by Sartomer Co., Ltd.) 4.0 parts by weight Polymer 1 5.0 parts by weight Initiator (manufactured by Ciba Geigy) Irgacure 907) 1.4 parts by weight Initiator 0.6 parts by weight (2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

  The polymer 1 is based on 100 mol% of a copolymer of benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate = 15.6: 37.0: 30.5: 16.9 (molar ratio). 2-methacryloyloxyethyl isocyanate was added at 16.9 mol%, and the weight average molecular weight was 42500. The same applies to the polymer 1 used in the following other paints.

(2) Coating for protective layer A coating for protective layer having the following composition was prepared, and a glass substrate with a coating film was prepared in the same manner as described above.
(Protective layer paint)
・ Monomer (SR399 manufactured by Sartomer Co., Ltd.) 7.1 parts by weight Polymer 1 8.8 parts by weight Epoxy resin 9.7 parts by weight (Epicoat 180S70 manufactured by Yuka Shell Epoxy Co., Ltd.)
Initiator (Irgacure 907 manufactured by Ciba Geigy Co., Ltd.) ... 1.4 parts by weight Initiator ... 1.0 part by weight (2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-
Tetraphenyl-1,2'-biimidazole)
・ Solvent (dimethyldiglycol): 38.0 parts by weight ・ Solvent (3-methoxybutyl acetate): 34.0 parts by weight

(3) Photosensitive paint for columnar projections Two types of photosensitive coatings S1 and S2 for columnar projections having the following compositions were prepared. Next, the prepared photosensitive coatings for columnar protrusions are applied onto a glass substrate by a spin coating method, prebaked at 100 ° C. for 3 minutes, exposed to the whole surface, and spray-developed using a 0.01% KOH aqueous solution. Then, a glass substrate with a coating film was produced by post-baking at 200 ° C. for 30 minutes.
(Photosensitive paint S1 for columnar protrusions)
Monomer (SR399 manufactured by Sartomer Co., Ltd.) 8.7 parts by weight Polymer 1 10.9 parts by weight Epoxy resin 12.1 parts by weight (Epicoat 180S70 manufactured by Yuka Shell Epoxy Co., Ltd.)
-Surfactant: 1.0 part by weight (Nippon Yuka nonionic HS-210)
・ Initiator (Irgacure 369 manufactured by Ciba Geigy Co., Ltd.) 1.2 parts by weight Initiator 1.0 part by weight (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 29.1 parts by weight (propylene glycol monomethyl ether acetate)
・ Solvent (Acetic acid-3-methyoxybutyl) 36.0 parts by weight

(Photosensitive paint S2 for columnar protrusions)
Monomer (SR399 manufactured by Sartomer Co., Ltd.) 8.7 parts by weight Polymer 1 10.9 parts by weight Epoxy resin 12.1 parts by weight (Epicoat 180S70 manufactured by Yuka Shell Epoxy Co., Ltd.)
・ Surfactant ... 2.0 parts by weight (Nippon Yuka nonionic HS-210)
・ Initiator (Irgacure 369 manufactured by Ciba Geigy Co., Ltd.) 1.2 parts by weight Initiator 1.0 part by weight (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 28.1 parts by weight (propylene glycol monomethyl ether acetate)
・ Solvent (Acetic acid-3-methyoxybutyl) 36.0 parts by weight

B. Impurity extraction treatment and measurement of voltage holding ratio / residual DC (ΔE) For the various glass substrates with a coating film produced in step 1, the impurity extraction treatment for liquid crystal (MLC-6846-000 manufactured by Merck Japan Co., Ltd.) is performed by the following method, and then the voltage holding ratio and residual DC (ΔE) of this liquid crystal are determined. The measurement was performed under the following measurement conditions, and the results are shown in Table 1 below.

The liquid crystal used had a voltage holding ratio of 98% or more measured under the following voltage holding ratio measurement conditions in the state before the impurity extraction treatment, and the residual DC (ΔE) measured under the following residual DC (ΔE) measuring conditions. ) Was 0.01 V or less.
(Impurity extraction method)
A glass substrate with a coating having a surface area of 4 cm ² is immersed in a liquid crystal having a capacity of 0.2 ml, and extraction is carried out by holding at 105 ° C. for 5 hours.

(Voltage holding ratio measurement conditions)
As a layer structure, a measurement cell consisting of substrate / electrode / alignment layer / liquid crystal / alignment layer / electrode / substrate is prepared, and liquid crystal subjected to impurity extraction treatment is injected and measured under the following conditions.
・ Distance between electrodes: 5 to 15 μm
・ Applied voltage pulse amplitude: 5V
・ Applied voltage pulse frequency: 60 Hz
・ Applied voltage pulse width: 16.67 msec

(Residual DC (ΔE) measurement conditions)
As a layer structure, a measurement cell comprising a substrate / electrode / alignment layer / liquid crystal / alignment layer / electrode / substrate is prepared, and liquid crystal subjected to impurity extraction treatment is injected, and residual DC (ΔE) ( In the voltage-capacitance hysteresis loop,
From the maximum capacitance (Cs) and the minimum capacitance (C0), the formula (C0 + Cs) /
Measure the voltage shift amount (indicated by the arrow in FIG. 2) in the capacitance specified in 2.
・ Distance between electrodes: 5 to 15 μm
Liquid crystal used: Capacitance saturation voltage (Vs ′ in FIG. 2) is 10V
・ Voltage-capacitance hysteresis loop measurement voltage range: -10V to + 10V

Production of color filter (1) Color filter sample 1
As a substrate for a color filter, a glass substrate (Corning 7059 glass) having a size of 100 mm × 100 mm and a thickness of 0.7 mm was prepared. After this substrate was washed according to a conventional method, a black matrix photosensitive paint having the above composition was applied to the entire surface of one side of the substrate, and mask exposure, development, and post-baking were performed to form a black matrix (thickness: 1.5 μm).

Next, a colored layer was formed using the three types of photosensitive paints R1, G1, and B1 for the colored layer having the above composition. That is, a red pattern photosensitive paint R1 was applied to the entire surface of the substrate on which the black matrix was formed by spin coating to form a red photosensitive resin layer, and prebaked (90 ° C., 3 minutes). . Thereafter, the red photosensitive resin layer is alignment-exposed using a photomask for a predetermined colored pattern, developed with a developer (0.05% KOH aqueous solution), and then post-baked (200 ° C., 30 minutes). Then, a red pattern (thickness: 1.5 μm) was formed at a predetermined position with respect to the black matrix pattern.
Similarly, a green pattern (thickness of 1.5 μm) was formed at a predetermined position with respect to the black matrix pattern using the photosensitive paint G1 for the green pattern. Further, a blue pattern (thickness: 1.5 μm) was formed at a predetermined position with respect to the black matrix pattern by using the photosensitive paint B1 for the blue pattern.
As a result, a color filter (sample 1) having a structure as shown in FIG. 1 was obtained.

(2) Color filter sample 2
A color filter (Sample 2) was produced in the same manner as Sample 1 except that three types of photosensitive paints R1, G2, and B1 having the above compositions were used as the photosensitive paint for the colored layer.

(3) Color filter sample 3
The protective layer paint having the above composition is applied by spin coating so as to cover the black matrix and the colored layer of the color filter (sample 2), and dried to form a protective layer having a thickness of 1.5 μm. A color filter (sample 3) having a structure as shown in FIG. 4 was obtained.

(4) Color filter sample 4
The columnar convex photosensitive paint S1 having the above composition was applied by spin coating so as to cover the protective layer of the color filter (sample 3), and prebaked (100 ° C., 3 minutes). Thereafter, exposure is performed using a predetermined columnar convex photomask, development is performed with a developer (0.01% KOH aqueous solution), and then post-baking (200 ° C., 30 minutes) is performed, and the height is 5 μm. A plurality of columnar protrusions were formed to obtain a color filter (sample 4) having a structure as shown in FIG.

(5) Color filter sample 5
A color filter (Sample 5) was prepared in the same manner as Sample 4 except that the photosensitive coating S2 having the above composition was used as the photosensitive coating for columnar convex portions.

Production of Liquid Crystal Display Device A transparent common electrode made of indium tin oxide (ITO) was formed on each of the color filters (samples 1 to 5).
Further, a glass substrate (Corning 7059 glass) having a size of 100 mm × 100 mm and a thickness of 0.7 mm was prepared as a transparent substrate. After this substrate is cleaned according to a standard method, thin film transistors (TFTs) are formed at a plurality of predetermined locations on the substrate, and transparent pixel electrodes are formed of indium tin oxide (ITO) so as to be connected to the drain electrodes of each TFT. Thus, a counter electrode substrate was produced.
Next, a polyimide resin coating was applied and dried to cover the transparent common electrode of the color filter and the transparent pixel electrode of the counter electrode substrate, and an alignment layer (thickness 0.07 μm) was provided to perform alignment treatment.
Next, liquid crystal display devices (Samples 1 to 5) were produced using these color filters and the counter electrode substrate. In addition, Merck Japan MLC-6846-000 was used as liquid crystal.

Evaluation of liquid crystal display devices For the five types of liquid crystal display devices (samples 1 to 5) produced, image display was continuously performed for 72 hours under the conditions of 23 ° C. and 60% RH, and the display quality was evaluated according to the following criteria. The results are shown in Table 2 below.
(Evaluation criteria for display quality)
○: Display quality is extremely good without image sticking and white unevenness ×: Image sticking and white unevenness are observed, and a display defect phenomenon is observed.

As shown in Table 2, each of the liquid crystal display devices of Samples 1, 3, and 4 has a liquid crystal layer in a position where each of the constituting color filters is in direct contact with the liquid crystal layer or through an alignment layer or a transparent electrode Is the color filter of the present invention that maintains the voltage holding ratio of the liquid crystal subjected to the impurity extraction treatment at 80% or more and the residual DC (ΔE) at 0.5 V or less. Even when the display is performed for a long time under high humidity, the display failure phenomenon does not occur.
On the other hand, in the liquid crystal display device of sample 2, the green pattern of the colored layer having a voltage holding ratio of less than 80% and a residual DC (ΔE) exceeding 0.5 V is in direct contact with the liquid crystal layer. In a liquid crystal display device, columnar protrusions having a voltage holding ratio of less than 80% and a residual DC (ΔE) of more than 0.5 V are in direct contact with the liquid crystal layer, so both image sticking and white unevenness are observed, resulting in a display failure phenomenon. Was recognized.

  This is useful in manufacturing a liquid crystal display device capable of high quality display.

It is a schematic sectional drawing which shows one Embodiment of the liquid crystal display device of this invention. It is a figure which shows the voltage-capacitance hysteresis loop for demonstrating residual DC ((DELTA) E). It is a schematic sectional drawing which shows other embodiment of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows other embodiment of the liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 '... Color filter 12 ... Board | substrate 14' ... Black matrix 15 '... Resin colored layer 401,501,601 ... Liquid crystal display device 405,505,605 ... Liquid crystal layer 411,511,611 ... Counter electrode board | substrate 420,514,613 ... Semiconductor drive elements (thin film transistors)
414 ... Resin light shielding layer 415 ... Resin colored layer 615 ... Resin colored layer 433, 506, 623 ... Common transparent electrode 413, 513 ... Transparent pixel electrode 614 ... Reflective electrode

Claims (3)

A common electrode substrate and a counter electrode substrate opposed to each other so as to provide a gap portion through a seal member; and a liquid crystal layer sealed in the gap portion, wherein the common electrode substrate has a common transparent electrode layer on the substrate. , the counter electrode substrate is a liquid crystal display that includes a resin colored layer consisting of a plurality of colors formed in a predetermined pattern corresponding to the semiconductor driving element resin light shielding layer and formed on the semiconductor driving element and the semiconductor driving element In the device manufacturing method ,
A liquid crystal having a voltage holding ratio of 95% or more and a residual DC (ΔE) of 0.05 V or less is prepared, and as a resin member, the voltage of the liquid crystal after being subjected to impurity extraction treatment by being immersed in the liquid crystal Selecting a resin member having a retention rate of 80% or more and a residual DC (ΔE) of 0.5 V or less, and using the resin member to form the resin light-shielding layer and the resin-colored layer. A method of manufacturing a liquid crystal display device. A color filter and a counter electrode substrate opposed to each other so as to provide a gap through a seal member, and a liquid crystal layer sealed in the gap, the color filter being sequentially laminated on the substrate and the substrate. In a manufacturing method of a liquid crystal display device comprising a resin colored layer composed of a plurality of colors and a common transparent electrode layer,
A liquid crystal having a voltage holding ratio of 95% or more and a residual DC (ΔE) of 0.05 V or less is prepared, and as a resin member, the voltage of the liquid crystal after being subjected to impurity extraction treatment by being immersed in the liquid crystal A liquid crystal display characterized in that a resin member having a retention rate of 80% or more and a residual DC (ΔE) of 0.5 V or less is selected, and the resin colored layer is formed using the resin member. Device manufacturing method . A common electrode substrate and a counter electrode substrate opposed to each other so as to provide a gap portion through a seal member; and a liquid crystal layer sealed in the gap portion, wherein the common electrode substrate has a common transparent electrode layer on the substrate. In the method of manufacturing a liquid crystal display device, the counter electrode substrate includes a substrate, a driving element layer sequentially laminated on the substrate, a reflective electrode layer, and a resin coloring layer composed of a plurality of colors.
A liquid crystal having a voltage holding ratio of 95% or more and a residual DC (ΔE) of 0.05 V or less is prepared, and as a resin member, the voltage of the liquid crystal after being subjected to impurity extraction treatment by being immersed in the liquid crystal A liquid crystal display characterized in that a resin member having a retention rate of 80% or more and a residual DC (ΔE) of 0.5 V or less is selected, and the resin colored layer is formed using the resin member. Device manufacturing method .

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