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WO2019026705A1 - Procédé de fabrication de dispositif d'affichage à cristaux liquides - Google Patents

Procédé de fabrication de dispositif d'affichage à cristaux liquides Download PDF

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Publication number
WO2019026705A1
WO2019026705A1 PCT/JP2018/027791 JP2018027791W WO2019026705A1 WO 2019026705 A1 WO2019026705 A1 WO 2019026705A1 JP 2018027791 W JP2018027791 W JP 2018027791W WO 2019026705 A1 WO2019026705 A1 WO 2019026705A1
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Prior art keywords
alignment film
liquid crystal
photo alignment
crystal display
film
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English (en)
Japanese (ja)
Inventor
伸一 平戸
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Sharp Corp
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Sharp Corp
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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers

Definitions

  • the present invention relates to a method of manufacturing a liquid crystal display. More specifically, the present invention relates to a method of manufacturing a liquid crystal display device having a photo alignment film.
  • a liquid crystal display device generally has an alignment film which controls the alignment of liquid crystal molecules (see, for example, Patent Documents 1 and 2).
  • the alignment film imparts an alignment regulating force to liquid crystal molecules by being subjected to alignment processing such as rubbing processing and photo alignment processing, for example.
  • alignment processing such as rubbing processing and photo alignment processing
  • the display quality may be degraded due to the dust generation from the rubbing cloth. Therefore, in recent years, a method of forming a photo alignment film by performing photo alignment processing of irradiating light such as ultraviolet light instead of rubbing processing has been studied.
  • an alignment film material containing a polymer (polymer) of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine as a constituent material (photo alignment film material) of the photo alignment film
  • the photo alignment treatment by polarized light irradiation When applied, decomposition of the polymer chain occurs along the direction of the fast axis of the polarized light, and a maleimide compound is formed as a decomposition product.
  • the maleimide compound as a decomposition product does not independently contribute to the alignment control force of the photo alignment film, and is sublimed by baking after the photo alignment processing.
  • the maleimide compound when the maleimide compound is not sufficiently sublimated and remains on the surface of the photo alignment film, the maleimide compound may drift and aggregate in the liquid crystal layer and then reattach to the surface of the photo alignment film. As a result, the orientation of the liquid crystal molecules may be disturbed from the aggregates of the maleimide compound as nuclei, that is, the anisotropy may be partially reduced and may appear as a bright spot.
  • the substrate having the photo alignment film is subjected to a liquid contact treatment with the anisotropy improving liquid, but the inventor examined it.
  • the anisotropy improvement liquid described in in particular, ozone water
  • the anisotropy may be significantly reduced by simply using it, which may cause a problem of afterimage. And there was room for improvement.
  • the invention described in Patent Document 2 is premised on manufacturing a liquid crystal display device having an inorganic alignment film, and there is room for improvement.
  • the present invention is made in view of the above-mentioned present situation, and it aims at providing a manufacturing method of a liquid crystal display which controls generating of a bright point, controlling a fall of anisotropy.
  • the inventors of the present invention have variously examined a method of manufacturing a liquid crystal display device which suppresses generation of a bright spot while suppressing a decrease in anisotropy, and the maleimide compound (degraded product generated after photo alignment treatment ) Was removed by washing. And it discovered that generation
  • the present invention has been achieved in consideration of the fact that the above-mentioned problems can be solved in a remarkable manner.
  • one embodiment of the present invention is a method of manufacturing a liquid crystal display device including a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, wherein at least one surface of the pair of substrates is A step (1) of forming a film of a photoalignment film material containing a polymer of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine, and a step of irradiating polarized light onto the film to form a photoalignment film (2) A process for producing a liquid crystal display comprising the step (3) of washing the photo alignment film with ozone water having a concentration of 5 ppm or less for 1 minute or less (hereinafter referred to as “first liquid crystal of the present invention It may be referred to as “a manufacturing method of a display device”.
  • the method of manufacturing a liquid crystal display device may further include the step (4) of firing the photo alignment film after the step (3).
  • the method of manufacturing a liquid crystal display further includes a step (4) of firing the photo alignment film between the step (2) and the step (3). It may be
  • Another aspect of the present invention is a method of manufacturing a liquid crystal display device comprising a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, wherein at least one surface of the pair of substrates is A step (1) of forming a film of a photoalignment film material containing a polymer of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine, and a step of irradiating polarized light onto the film to form a photoalignment film (2)
  • a process for producing a liquid crystal display comprising the step (3) of washing the photo alignment film with alkaline reducing water (hereinafter referred to as “the process for producing the second liquid crystal display of the present invention”) It may be said).
  • the method of manufacturing a liquid crystal display device may further include the step (4) of firing the photo alignment film after the step (3).
  • the method for manufacturing a liquid crystal display device further includes the step (4) of firing the photo alignment film between the step (2) and the step (3). May be included.
  • the display mode of the liquid crystal display device may be an IPS mode or an FFS mode.
  • the manufacturing method of the liquid crystal display device which suppresses generation
  • X to Y means “X or more and Y or less”.
  • Embodiment 1 relates to a method of manufacturing the first liquid crystal display device of the present invention.
  • a film of a photoalignment film material is formed on at least one surface of a pair of substrates.
  • the film made of the photo alignment film material may be formed by applying the photo alignment film material on at least one surface of the pair of substrates and then performing pre-baking (drying), main baking and the like as appropriate.
  • the pair of substrates may be previously cleaned with water or the like.
  • the application of the photoalignment film material may be performed by, for example, a method such as a flexographic printing method or an inkjet method.
  • Pre-baking is a heat treatment to volatilize (dry) the solvent in the photo alignment film material.
  • the solvent may be partially or completely removed.
  • This firing is a heat treatment that promotes the thermochemical reaction (for example, imidization reaction) of the polymer (polymer) in the photo alignment film material, or completely evaporates the solvent in the photo alignment film material. And may be performed at a temperature higher than the pre-baking.
  • the photo alignment film material is an alignment film material containing a polymer (polymer) of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine, that is, a photodegradable alignment film material.
  • the photoalignment film material may further contain a solvent.
  • the polymer of carboxylic acid dianhydride having a cyclobutane skeleton and a diamine in the photoalignment film material may contain a polyamic acid or a derivative thereof represented by the following chemical formula (1).
  • this polyamic acid is a polymer of a carboxylic acid dianhydride having a cyclobutane skeleton and an aromatic diamine or an aliphatic diamine.
  • R ′ represents an aromatic compound or an aliphatic compound.
  • r 1 , r 2 , r 3 and r 4 independently represent a hydrogen atom or an organic group having 1 to 4 carbon atoms.
  • n represents the degree of polymerization.
  • R ′ represents an aromatic compound or an aliphatic compound.
  • r 1 , r 2 , r 3 and r 4 independently represent a hydrogen atom or an organic group having 1 to 4 carbon atoms.
  • n represents the degree of polymerization.
  • a combination of a pair of substrates for example, a combination of a thin film transistor array substrate and a color filter substrate generally used in the field of liquid crystal display devices can be mentioned.
  • polarized irradiation photoalignment treatment
  • the polymer chains in the film by the photoalignment film material are decomposed and cut along the fast axis direction of polarized light.
  • the film made of the photo alignment film material contains the polyimide represented by the above chemical formula (2)
  • the polyimide along the fast axis direction of polarized light Is decomposed to form a maleimide compound represented by the following chemical formula (3) as a decomposition product.
  • the maleimide compound as a decomposition product does not independently contribute to the alignment control force of the photo alignment film, but if it is largely left on the surface of the photo alignment film, it floats in the liquid crystal layer to be formed later and is aggregated. And re-adhered to the surface of the photo alignment film. As a result, the orientation of the liquid crystal molecules may be disturbed with the maleimide compound aggregate as a nucleus and may appear as a bright spot.
  • the maleimide compound can be efficiently removed by washing the photo alignment film in a later step.
  • R ′ represents an aromatic compound or an aliphatic compound.
  • r 1 , r 2 , r 3 and r 4 independently represent a hydrogen atom or an organic group having 1 to 4 carbon atoms.
  • n represents the degree of polymerization.
  • Polarized irradiation may be performed through a wire grid polarizer.
  • the polarized light irradiated to the film by the photo alignment film material is preferably polarized ultraviolet light.
  • the wavelength of polarized ultraviolet light may be 100 to 400 nm, but can be appropriately selected via a filter or the like according to the composition of the film of the photoalignment film material (for example, the type of polyimide).
  • a filter or the like according to the composition of the film of the photoalignment film material (for example, the type of polyimide).
  • a cut filter for cutting polarized ultraviolet light having a wavelength of 240 nm or less in order to avoid the influence on the deterioration of thin film transistor elements, color fading of color filter layers, etc.
  • the photo alignment film is washed with ozone water having a concentration of 5 ppm or less for 1 minute or less.
  • the maleimide compound generated at the time of formation of the photo alignment film can be removed while suppressing the decrease in anisotropy, and as a result, the generation of the bright spot can be suppressed.
  • the concentration of ozone water is 5 ppm or less.
  • concentration of ozone water is higher than 5 ppm, the removal rate of the maleimide compound is increased, but the anisotropy of the photo alignment film is significantly reduced.
  • the reason is as follows.
  • the polarized light irradiation (photo alignment treatment) causes decomposition of the polymer chain also in the deep part (deep part in the thickness direction) in addition to the surface of the photo alignment film, and a maleimide compound is generated. Therefore, while cleaning with a high concentration of ozone water makes it easy to remove the maleimide compound to the deep part of the photo alignment film, the polymer chains contributing to the anisotropy present on the surface of the photo alignment film are easily broken.
  • the anisotropy of the photo alignment film is significantly reduced.
  • the concentration of ozone water is preferably 1 ppm or more.
  • the cleaning time with ozone water is less than one minute.
  • the cleaning time with ozone water is longer than 1 minute, the removal rate of the maleimide compound is increased, but the anisotropy of the photo alignment film is significantly reduced for the same reason as described above.
  • the cleaning time with ozone water is preferably 20 seconds or more. As described above, when ozone water is used, since the cleaning time of the photo alignment film is short, the cleaning apparatus can be miniaturized, which contributes to the improvement of the manufacturing efficiency.
  • ozone water is supplied to a substrate having a photo alignment film formed on the surface, and a liquid film of ozone water is formed on the surface of the photo alignment film. Then, the liquid film of ozone water is washed (rinsed) with pure water (DIW) in the order of an aqua knife and a shower, and the ozone water is replaced with pure water. Thereafter, water is removed by an air knife to dry the surface of the photo alignment film.
  • DIW pure water
  • the baking temperature of the photo alignment film is preferably 200 to 240 ° C.
  • the baking temperature of the photo alignment film is lower than 200 ° C., sublimation of the maleimide compound may not be sufficiently promoted.
  • the baking temperature of the photo alignment film is higher than 240 ° C., for example, when a thin film transistor array substrate and a color filter substrate are used in combination as a pair of substrates, in addition to the thermal decomposition of the photo alignment film, the organic insulating film of the thin film transistor array substrate Thermal decomposition of the (interlayer insulating film), fading of the color filter layer, and the like may also occur.
  • the baking time of the photo alignment film is preferably 10 to 60 minutes. If the baking time of the photo alignment film is shorter than 10 minutes, the maleimide compound may not be sufficiently sublimated. When the baking time of the photo alignment film is longer than 60 minutes, the number of baking apparatuses may need to be increased, and the manufacturing efficiency may be reduced. From the viewpoint of shortening the baking time of the photo alignment film, it is effective to wash the photo alignment film before baking as in the present embodiment to reduce the remaining amount of the maleimide compound in advance.
  • the liquid crystal display device is completed by bonding a pair of substrates via a sealing material so as to sandwich the liquid crystal layer.
  • members such as a polarizing plate and a backlight may be appropriately disposed.
  • the liquid crystal layer can be formed, for example, by sealing a liquid crystal material between a pair of substrates by a method such as a dropping method or an injection method.
  • the liquid crystal layer is formed by a dropping method, for example, the following process is adopted. First, a sealing material is applied on one surface of a pair of substrates, and a liquid crystal material is dropped on the other surface. Then, a pair of substrates is attached by a sealing material to form a liquid crystal layer, and the sealing material is cured.
  • the following process is adopted. First, a sealing material is applied on one surface of a pair of substrates, and then the pair of substrates is bonded with the sealing material to cure the sealing material. Then, a liquid crystal material is injected between the pair of substrates in a vacuum state to form a liquid crystal layer.
  • the sealing material may be one that is cured by ultraviolet light (ultraviolet curing type) or may be one that is cured by heat (thermosetting type), or one that is cured by both of them (ultraviolet and thermal curing Type).
  • ultraviolet light ultraviolet light
  • thermosetting type thermosetting type
  • a light shielding mask may be appropriately disposed to the photo alignment film.
  • the display mode of the liquid crystal display device may be IPS mode or FFS mode, so-called horizontal alignment mode, because the viewing angle characteristics are excellent.
  • the display mode of the liquid crystal display device is the horizontal alignment mode
  • the polymer (polymer) in the photo alignment film material a polyamic acid represented by the above chemical formula (1) or a derivative thereof is preferably used.
  • the photo alignment film has a function as a horizontal photo alignment film that aligns liquid crystal molecules present in the vicinity in a direction parallel to the surface.
  • that the liquid crystal molecules are oriented in a direction parallel to the surface of the photo alignment film means that the pretilt angle of the liquid crystal molecules is 0 to 0.5 ° with respect to the surface of the photo alignment film, which is preferable.
  • the pretilt angle of the liquid crystal molecules means the angle at which the major axis of the liquid crystal molecules is inclined with respect to the surface of the photo alignment film when the voltage applied to the liquid crystal layer is less than the threshold voltage (including no voltage application). .
  • the above-described various processes may be performed on at least one of the pair of substrates constituting the liquid crystal display device.
  • the other may be subjected to treatments different from the various treatments described above.
  • rubbing treatment may be applied instead of photo alignment treatment
  • a cleaning process may not be performed, or a photoalignment film composed of a photoalignment film material of a type different from the photolytic type may be formed.
  • Second Embodiment Embodiment 2 relates to the first method for manufacturing a liquid crystal display device of the present invention.
  • the second embodiment is the same as the first embodiment except that the baking of the photo alignment film is performed after the formation of the photo alignment film and before the cleaning of the photo alignment film, and therefore the description of the overlapping points is appropriately omitted. Do.
  • a film of a photoalignment film material containing a polymer (polymer) of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine is formed on at least one surface of a pair of substrates.
  • the photo alignment film is washed with ozone water having a concentration of 5 ppm or less for 1 minute or less.
  • the maleimide compound can be removed while suppressing the decrease in anisotropy, and as a result, the generation of bright spots can be suppressed.
  • liquid crystal display device is completed by bonding a pair of substrates via a sealing material so as to sandwich the liquid crystal layer.
  • Third Embodiment Embodiment 3 relates to a method of manufacturing a second liquid crystal display device of the present invention.
  • the third embodiment is the same as the first embodiment except that the cleaning of the photo alignment film is performed with the alkaline reduced water, and therefore the description of the overlapping points is appropriately omitted.
  • a film of a photoalignment film material containing a polymer (polymer) of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine is formed on at least one surface of a pair of substrates.
  • alkali reduced water for example, one obtained by passing ammonia and hydrogen gas through water can be used.
  • the pH of the alkali reduced water is preferably 9 to 10.
  • the washing time with alkaline reduced water is not particularly limited, but is preferably 1 to 3 minutes. If the washing time with alkali reduced water is shorter than 1 minute, the maleimide compound may not be sufficiently removed, and the generation of bright spots may not be sufficiently suppressed. When the cleaning time with alkaline reduced water is longer than 3 minutes, the manufacturing efficiency may decrease due to the increase in the size of the cleaning apparatus and the increase in the conveyance time.
  • liquid crystal display device is completed by bonding a pair of substrates via a sealing material so as to sandwich the liquid crystal layer.
  • the fourth embodiment relates to a method of manufacturing a second liquid crystal display device of the present invention.
  • the fourth embodiment is the same as the third embodiment except that the baking of the photo alignment film is performed after the formation of the photo alignment film and before the cleaning of the photo alignment film, and therefore the description of the overlapping points is appropriately omitted. Do.
  • a film of a photoalignment film material containing a polymer (polymer) of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine is formed on at least one surface of a pair of substrates.
  • liquid crystal display device is completed by bonding a pair of substrates via a sealing material so as to sandwich the liquid crystal layer.
  • the photoalignment film materials used in manufacturing the liquid crystal display device were as follows.
  • ⁇ Photo alignment film material A> First, cyclobutanetetracarboxylic acid dianhydride and three kinds of aromatic diamines are reacted to form a polyamic acid P1 represented by the following chemical formula (4) and a polyamic acid P2 represented by the following chemical formula (5) , And formed a polyamic acid P3 represented by the following chemical formula (6). Then, 30 mol% of the polyamic acid P1, 10 mol% of the polyamic acid P2, and 60 mol% of the polyamic acid P3 are mixed to form a solid, and then the photoalignment film material A is diluted by using a solvent. Prepared.
  • a solvent a mixture of N-methyl-2-pyrrolidone (a good solvent) and butyl cellosolve (a poor solvent) at a weight ratio of 80:20 was used.
  • the solid content concentration in the photo alignment film material A was 6% by weight.
  • Example 1-1 The liquid crystal display device of Example 1-1 was manufactured by the manufacturing method of Embodiment 1.
  • the light alignment film material A was applied by flexographic printing on the surfaces of the thin film transistor array substrate for FFS mode and the color filter substrate. Thereafter, temporary baking was performed on the photo alignment film material A at 80 ° C. for 2 minutes, and then main baking was performed at 230 ° C. for 30 minutes. As a result, the imidization reaction of polyamic acids P1, P2 and P3 in the photo alignment film material A proceeded, and a film (thickness: 100 nm) of the photo alignment film material A was formed.
  • the film made of the photo alignment film material A was irradiated with polarized ultraviolet light (wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2 ) passing through the wire grid polarizing plate to form a photo alignment film.
  • polarized ultraviolet light wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2
  • a maleimide compound was also produced as a decomposition product.
  • the photo alignment film was washed with ozone water having a concentration of 5 ppm for 1 minute. Specifically, first, the two substrates on which the photoalignment film was formed were immersed in ozone water (concentration: 5 ppm) placed in a beaker for 1 minute, and then pulled up. Subsequently, the two pulled-up substrates were rinsed (rinsed) with pure water for 1 minute, and then dried by blowing clean dry air (CDA).
  • CDA clean dry air
  • Example 1-2 A liquid crystal display device of Example 1-2 was manufactured in the same manner as in Example 1-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 5 ppm for 20 seconds.
  • Example 1-3 A liquid crystal display device of Example 1-3 was manufactured in the same manner as Example 1-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 1 ppm for 1 minute.
  • Example 1-4 A liquid crystal display device of Example 1-4 was manufactured in the same manner as in Example 1-1, except that the photo alignment film was washed with ozone water having a concentration of 1 ppm for 20 seconds.
  • Comparative Example 1-1 A liquid crystal display device of Comparative Example 1-1 was manufactured in the same manner as Example 1-1 except that the photo alignment film was not washed.
  • Comparative Example 1-2 A liquid crystal display device of Comparative Example 1-2 was manufactured in the same manner as Example 1-1 except that the cleaning of the photo alignment film was performed for 2 minutes with ozone water having a concentration of 5 ppm.
  • Comparative Example 1-3 A liquid crystal display device of Comparative Example 1-3 was manufactured in the same manner as in Example 1-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 5 ppm for 3 minutes.
  • Comparative Example 1-4 A liquid crystal display device of Comparative Example 1-4 was manufactured in the same manner as in Example 1-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 20 ppm for 1 minute.
  • Comparative Example 1-5 A liquid crystal display device of Comparative Example 1-5 was manufactured in the same manner as Example 1-1 except that the cleaning of the photo alignment film was performed for 2 minutes with ozone water having a concentration of 20 ppm.
  • Comparative Example 1-6 A liquid crystal display device of Comparative Example 1-6 was manufactured in the same manner as in Example 1-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 20 ppm for 3 minutes.
  • the afterimage was evaluated by the following method and used as an index of anisotropy.
  • a rectangular voltage of 5 Vrms and 30 Hz was continuously applied to the liquid crystal display device of each example for 5 days under an environment of 60 ° C. Thereafter, the voltage application is stopped, and the liquid crystal display device of each example is visually observed in a state (normally black state) sandwiched between two linear polarizing plates disposed in cross nicol, and the brightness at the time of black display ( The afterimage level was evaluated from the darkness).
  • the results are shown in Table 1.
  • the judgment criteria were as follows. :: The black display was very dark and the afterimage level was very good. ⁇ : The black display was dark and the afterimage level was good.
  • the residual ratio of the maleimide compound was calculated by the following method and used as an index of the degree of occurrence of the bright spot.
  • the comparative example is compared with the state immediately after cleaning of the photo alignment film.
  • a sample was extracted from the surface of the photoalignment film using a mixed solution of acetonitrile and methanol.
  • Examples 1-1 to 1-4 the afterimage level was good. Furthermore, in Examples 1-1 to 1-4, the residual rate of the maleimide compound was generally lower than that of Comparative Example 1-1, and in particular, dimers and trimers were sufficiently removed. From the above, it was found that in Examples 1-1 to 1-4, a method of manufacturing a liquid crystal display device can be realized while suppressing the occurrence of bright spots while suppressing the decrease in anisotropy. It was also found that cleaning the photo alignment film with ozone water is useful in removing dimers and trimers that are easily aggregated and effectively suppressing the generation of bright spots.
  • Comparative Example 1-1 although the residual image level was good as in Examples 1-1 to 1-4, since the photo alignment film was not washed, the residual ratio of the maleimide compound was changed to Examples 1-1 to 1-. Overall higher than four.
  • Comparative Examples 1-2 to 1-6 although the residual ratio of the maleimide compound was overall lower than Examples 1-1 to 1-4, the concentration of ozone water used at the time of washing was higher than 5 ppm. And / or the residual image level was worse than Examples 1-1 to 1-4 because the cleaning time with ozone water was longer than one minute.
  • Example 2-1 The liquid crystal display device of Example 2-1 was manufactured by the manufacturing method of Embodiment 2.
  • the light alignment film material A was applied by flexographic printing on the surfaces of the thin film transistor array substrate for FFS mode and the color filter substrate. Thereafter, temporary baking was performed on the photo alignment film material A at 80 ° C. for 2 minutes, and then main baking was performed at 230 ° C. for 30 minutes. As a result, the imidization reaction of polyamic acids P1, P2 and P3 in the photo alignment film material A proceeded, and a film (thickness: 100 nm) of the photo alignment film material A was formed.
  • the film made of the photo alignment film material A was irradiated with polarized ultraviolet light (wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2 ) passing through the wire grid polarizing plate to form a photo alignment film.
  • polarized ultraviolet light wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2
  • a maleimide compound was also produced as a decomposition product.
  • the photo alignment film was washed with ozone water having a concentration of 5 ppm for 1 minute. Specifically, first, the two substrates on which the photoalignment film was formed were immersed in ozone water (concentration: 5 ppm) placed in a beaker for 1 minute, and then pulled up. Subsequently, the two pulled-up substrates were rinsed (rinsed) with pure water for 1 minute, and then dried by blowing clean dry air (CDA).
  • CDA clean dry air
  • Example 2-2 A liquid crystal display device of Example 2-2 was manufactured in the same manner as in Example 2-1, except that the photo alignment film was washed with ozone water having a concentration of 5 ppm for 20 seconds.
  • Example 2-3 A liquid crystal display device of Example 2-3 was manufactured in the same manner as in Example 2-1 except that the photo alignment film was washed with ozone water having a concentration of 1 ppm for 1 minute.
  • Example 2-4 A liquid crystal display device of Example 2-4 was manufactured in the same manner as Example 2-1 except that the photo alignment film was washed with ozone water having a concentration of 1 ppm for 20 seconds.
  • Comparative example 2-1 A liquid crystal display device of Comparative Example 2-1 was manufactured in the same manner as Example 2-1 except that the photo alignment film was not washed. Comparative Example 2-1 is substantially the same as Comparative Example 1-1.
  • Comparative Example 2-2 A liquid crystal display device of Comparative Example 2-2 was manufactured in the same manner as in Example 2-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 5 ppm for 3 minutes.
  • Comparative Example 2-3 A liquid crystal display device of Comparative Example 2-3 was manufactured in the same manner as in Example 2-1 except that the cleaning of the photo alignment film was performed with ozone water having a concentration of 20 ppm for 1 minute.
  • Comparative Example 2-4 A liquid crystal display device of Comparative Example 2-4 was manufactured in the same manner as in Example 2-1 except that the cleaning of the photo alignment film was performed for 3 minutes with ozone water having a concentration of 20 ppm.
  • Examples 2-1 to 2-4 the afterimage level was good. Furthermore, in Examples 2-1 to 2-4, the residual ratio of the maleimide compound was generally lower than in Comparative Example 2-1, and in particular, the dimer was sufficiently removed. In addition, in this evaluation, there is also a possibility of sample extraction variation, and unlike the above evaluation 1 a trimer of the maleimide compound was not detected, but the residual rate of monomer and dimer is sufficient. It could be evaluated. From the above, it was found that in Examples 2-1 to 2-4, it is possible to realize a method of manufacturing a liquid crystal display device which suppresses the occurrence of bright spots while suppressing the decrease in anisotropy.
  • Comparative Example 2-1 although the residual image level was good as in Examples 2-1 to 2-4, since the cleaning of the photo alignment film was not performed, the residual ratio of the maleimide compound was changed to Examples 2-1 to 2-2. Overall higher than four.
  • Comparative Examples 2-2 to 2-4 although the residual ratio of the maleimide compound was generally lower than Examples 2-1 to 2-4, the concentration of ozone water used at the time of washing was higher than 5 ppm. And / or the residual image level was worse than Examples 2-1 to 2-4 because the cleaning time with ozone water was longer than one minute.
  • a first group (Examples 1-1 to 1-4) in which formation of a photoalignment film (irradiation with polarized ultraviolet light), cleaning of the photoalignment film, and firing of the photoalignment film are performed in order
  • Comparative Examples 1-2 to 1-6 formation of a photoalignment film (irradiation of polarized ultraviolet light), baking of the photoalignment film, and cleaning of the photoalignment film in this order
  • the second group (Example 2-)
  • the conditions for cleaning the photo alignment film (the concentration of ozone water and the cleaning time) are the same as in Examples 1 to 2-4 and Comparative Examples 2-2 to 2-4)
  • they are compared with each other (for example, Comparative Example) 1-3 and Comparative Example 2-2, or Comparative Example 1-4 and Comparative Example 2-3)
  • the afterimage level of the first group is equal to or higher than the afterimage level of the second group.
  • Example 3-1 The liquid crystal display device of Example 3-1 was manufactured by the manufacturing method of Embodiment 3.
  • the light alignment film material A was applied by flexographic printing on the surfaces of the thin film transistor array substrate for FFS mode and the color filter substrate. Thereafter, temporary baking was performed on the photo alignment film material A at 80 ° C. for 2 minutes, and then main baking was performed at 230 ° C. for 30 minutes. As a result, the imidization reaction of polyamic acids P1, P2 and P3 in the photo alignment film material A proceeded, and a film (thickness: 100 nm) of the photo alignment film material A was formed.
  • the film made of the photo alignment film material A was irradiated with polarized ultraviolet light (wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2 ) passing through the wire grid polarizing plate to form a photo alignment film.
  • polarized ultraviolet light wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2
  • a maleimide compound was also produced as a decomposition product.
  • the photo alignment film was washed with alkaline reducing water for 1 minute. Specifically, first, ammonia and hydrogen gas were passed through water to prepare alkaline reduced water of pH 9.4 to 9.5. The concentration of ammonia in the alkali reduced water was 1 mg / L, and the concentration of hydrogen was 1.4 ppm. Then, after immersing the two substrates on which the photo alignment film was formed in the alkali reducing water placed in the beaker, the substrate was pulled up. Subsequently, the two pulled-up substrates were rinsed (rinsed) with pure water for 1 minute, and then dried by blowing clean dry air (CDA).
  • CDA clean dry air
  • Example 3-2 A liquid crystal display device of Example 3-2 was manufactured in the same manner as in Example 3-1 except that the cleaning of the photo alignment film was performed for 2 minutes with alkali reducing water.
  • Example 3-3 A liquid crystal display device of Example 3-3 was manufactured in the same manner as in Example 3-1 except that the cleaning of the photo alignment film was performed for 3 minutes with alkaline reducing water.
  • Comparative Example 3-1 A liquid crystal display device of Comparative Example 3-1 was manufactured in the same manner as Example 3-1 except that the photo alignment film was not washed. Comparative Example 3-1 is substantially the same as Comparative Example 1-1.
  • Examples 3-1 to 3-3 the afterimage level was very good. Furthermore, in Examples 3-1 to 3-3, the residual ratio of the maleimide compound was generally lower than that of Comparative Example 3-1. From the above, it was found that in Examples 3-1 to 3-3, a method of manufacturing a liquid crystal display device is realized which suppresses the occurrence of bright spots while suppressing the decrease in anisotropy.
  • Comparative Example 3-1 the residual image level was worse than in Examples 3-1 to 3-3, and furthermore, the cleaning of the photo alignment film was not performed, so the residual ratio of the maleimide compound was in Examples 3-1 to 3-3. It was higher than the whole.
  • Example 4-1 The liquid crystal display device of Example 4-1 was manufactured by the manufacturing method of Embodiment 4.
  • the light alignment film material A was applied by flexographic printing on the surfaces of the thin film transistor array substrate for FFS mode and the color filter substrate. Thereafter, temporary baking was performed on the photo alignment film material A at 80 ° C. for 2 minutes, and then main baking was performed at 230 ° C. for 30 minutes. As a result, the imidization reaction of polyamic acids P1, P2 and P3 in the photo alignment film material A proceeded, and a film (thickness: 100 nm) of the photo alignment film material A was formed.
  • the film made of the photo alignment film material A was irradiated with polarized ultraviolet light (wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2 ) passing through the wire grid polarizing plate to form a photo alignment film.
  • polarized ultraviolet light wavelength: 240 to 400 nm, irradiation amount: 1 J / cm 2
  • a maleimide compound was also produced as a decomposition product.
  • the photo alignment film was washed with alkaline reducing water for 1 minute. Specifically, first, ammonia and hydrogen gas were passed through water to prepare alkaline reduced water of pH 9.4 to 9.5. The concentration of ammonia in the alkali reduced water was 1 mg / L, and the concentration of hydrogen was 1.4 ppm. Then, after immersing the two substrates on which the photo alignment film was formed in the alkali reducing water placed in the beaker, the substrate was pulled up. Subsequently, the two pulled-up substrates were rinsed (rinsed) with pure water for 1 minute, and then dried by blowing clean dry air (CDA).
  • CDA clean dry air
  • Example 4-2 A liquid crystal display device of Example 4-2 was manufactured in the same manner as Example 4-1 except that the cleaning of the photo alignment film was performed for 2 minutes with alkaline reducing water.
  • Example 4-3 A liquid crystal display device of Example 4-3 was manufactured in the same manner as in Example 4-1 except that the cleaning of the photo alignment film was performed with alkaline reducing water for 3 minutes.
  • Comparative Example 4-1 A liquid crystal display device of Comparative Example 4-1 was manufactured in the same manner as Example 4-1 except that the cleaning of the photo alignment film was not performed. Comparative Example 4-1 is substantially the same as Comparative Example 1-1.
  • Examples 4-1 to 4-3 the afterimage level was good. Furthermore, in Examples 4-1 to 4-3, the residual ratio of the maleimide compound was generally lower than that of Comparative Example 4-1. In addition, in this evaluation, there is also a possibility of sample extraction variation, and unlike the evaluation 3 mentioned above, although the trimer of the maleimide compound was not detected, the residual rate of monomer and dimer is sufficient. It could be evaluated. From the above, it was found that in Examples 4-1 to 4-3, a method of manufacturing a liquid crystal display device can be realized which suppresses the occurrence of bright spots while suppressing the decrease in anisotropy.
  • Comparative Example 4-1 although the residual image level was good as in Examples 4-1 to 4-3, since the photo alignment film was not washed, the residual ratio of the maleimide compound was determined in Examples 4-1 to 4-4. Overall higher than three.
  • Examples 3-1 to 3-3 in which the formation of the photoalignment film (irradiation with polarized ultraviolet light), the cleaning of the photoalignment film, and the baking of the photoalignment film are performed sequentially in the evaluations 3 and 4 described above.
  • the fourth group Examples 4-1 to 4-3) in which the formation of the photoalignment film (irradiation of polarized ultraviolet light), the baking of the photoalignment film, and the cleaning of the photoalignment film are performed in order. Comparing the same example with the same example (for example, Example 3-1 and Example 4-1), or the same as Example 3-2 and Example 4-2, the cleaning conditions (the cleaning time with the alkali reducing water) of the alignment film are compared with each other.
  • the afterimage level of the third group was better than the afterimage level of the fourth group. That is, it was found that it is preferable to sequentially perform the formation of the photoalignment film (irradiation of polarized ultraviolet light), the washing of the photoalignment film, and the baking of the photoalignment film from the viewpoint of suppressing the decrease in anisotropy. After the formation of the photoalignment film (after the irradiation of polarized ultraviolet light) and before the baking of the photoalignment film, if the photoalignment film is washed with alkali reducing water, the maleimide compound is suppressed while minimizing the damage to the surface of the photoalignment film.
  • the alignment control power of the photo alignment film was improved and the residual image level was improved, because Furthermore, it is considered that the alignment control power of the photo alignment film is further improved by baking after cleaning the photo alignment film, and as a result, the residual image level is further improved.
  • One embodiment of the present invention is a method of manufacturing a liquid crystal display device including a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, wherein a cyclobutane skeleton is formed on at least one surface of the pair of substrates.
  • the step (3) of washing the photo alignment film with ozone water having a concentration of 5 ppm or less for 1 minute or less (a method of producing the first liquid crystal display device of the present invention) ) May be.
  • a method of manufacturing a liquid crystal display device is realized which suppresses the occurrence of bright spots while suppressing the decrease in anisotropy.
  • the method of manufacturing a liquid crystal display device may further include the step (4) of firing the photo alignment film after the step (3). According to such a configuration, even if the maleimide compound remains after the step (3), the maleimide compound is sublimated in the step (4), and the remaining amount can be further reduced.
  • the method of manufacturing a liquid crystal display further includes a step (4) of firing the photo alignment film between the step (2) and the step (3). It may be According to such a configuration, the maleimide compound is sublimed in the step (4), and the residual amount of the maleimide compound can be reduced before the step (3) is performed.
  • Another aspect of the present invention is a method of manufacturing a liquid crystal display device comprising a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, wherein at least one surface of the pair of substrates is A step (1) of forming a film of a photoalignment film material containing a polymer of a carboxylic acid dianhydride having a cyclobutane skeleton and a diamine, and a step of irradiating polarized light onto the film to form a photoalignment film (2)
  • a process for producing a liquid crystal display (a process for producing a liquid crystal display according to the present invention) comprising the step (3) of washing the photo alignment film with alkaline reducing water. It is also good.
  • a method of manufacturing a liquid crystal display device is realized which suppresses the occurrence of bright spots while suppressing the decrease in anisotropy.
  • the method of manufacturing a liquid crystal display device may further include the step (4) of firing the photo alignment film after the step (3). According to such a configuration, even if the maleimide compound remains after the step (3), the maleimide compound is sublimated in the step (4), and the remaining amount can be further reduced.
  • the method for manufacturing a liquid crystal display device further includes the step (4) of firing the photo alignment film between the step (2) and the step (3). May be included.
  • the maleimide compound is sublimed in the step (4), and the residual amount of the maleimide compound can be reduced before the step (3) is performed.
  • the display mode of the liquid crystal display device may be an IPS mode or an FFS mode. According to such a configuration, a method of manufacturing a liquid crystal display device in an IPS mode or an FFS mode can be realized, which suppresses the occurrence of bright spots while suppressing the decrease in anisotropy.

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Abstract

La présente invention concerne un procédé de fabrication d'un dispositif d'affichage à cristaux liquides, grâce auquel l'apparition de pixels toujours allumés est supprimée tandis que la réduction de l'anisotropie est également supprimée. Ce procédé de fabrication d'un dispositif d'affichage à cristaux liquides pourvu d'une paire de substrats et d'une couche de cristaux liquides prise en sandwich entre la paire de substrats comprend une étape (1) de formation d'un film d'un matériau de film d'alignement optique contenant un polymère d'une diamine et d'un dianhydride d'acide carboxylique ayant un squelette cyclobutane sur la surface d'au moins l'un de la paire de substrats, une étape (2) d'irradiation du film avec une lumière polarisée et de formation d'un film d'alignement optique, et une étape (3) de rinçage du film d'alignement optique avec de l'eau ozonée ayant une concentration de 5 ppm ou moins pendant 1 minute ou moins.
PCT/JP2018/027791 2017-08-01 2018-07-25 Procédé de fabrication de dispositif d'affichage à cristaux liquides Ceased WO2019026705A1 (fr)

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JP2017149266 2017-08-01

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014228841A (ja) * 2013-05-27 2014-12-08 株式会社ジャパンディスプレイ 液晶表示装置およびその製造方法
WO2015064630A1 (fr) * 2013-10-30 2015-05-07 Dic株式会社 Élément d'affichage à cristaux liquides
JP2015148747A (ja) * 2014-02-07 2015-08-20 株式会社ジャパンディスプレイ 液晶表示装置の製造方法および製造装置
WO2017119461A1 (fr) * 2016-01-07 2017-07-13 日産化学工業株式会社 Agent d'alignement de cristaux liquides, film d'alignement de cristaux liquides et élément d'affichage à cristaux liquides les utilisant

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014228841A (ja) * 2013-05-27 2014-12-08 株式会社ジャパンディスプレイ 液晶表示装置およびその製造方法
WO2015064630A1 (fr) * 2013-10-30 2015-05-07 Dic株式会社 Élément d'affichage à cristaux liquides
JP2015148747A (ja) * 2014-02-07 2015-08-20 株式会社ジャパンディスプレイ 液晶表示装置の製造方法および製造装置
WO2017119461A1 (fr) * 2016-01-07 2017-07-13 日産化学工業株式会社 Agent d'alignement de cristaux liquides, film d'alignement de cristaux liquides et élément d'affichage à cristaux liquides les utilisant

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