JPS5952803B2 - Manufacturing method of alignment substrate for liquid crystal display - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an alignment substrate that causes liquid crystals to have partially different alignments, and more specifically, to provide an alignment substrate that can easily form an extremely dense pattern. be.

Conventionally, fixed display patterns used in liquid crystal display elements and the like are generally printed on the outer surface of the cell, or coated with a rough pattern on the alignment surface with a substance that prevents horizontal alignment.

However, these methods cannot form sufficiently dense images, and when printing on horizontally oriented surfaces, the adhesion of the vertically oriented material becomes a problem, and in reality, problems such as stains on the oriented surfaces occur. There are many points.

The method of the present invention differs from conventional methods in that the surface of vertically oriented silicone resin is modified by plasma treatment, and since the material is the same for both orientations, there is no problem with adhesion. The present invention provides a substrate having excellent performance in terms of fineness and uniformity of orientation, resistance to staining, etc.

This substrate uses plasma treatment to make parts of the substrate surface vertically aligned and non-vertically aligned, and the non-vertically aligned parts are made horizontally aligned by rubbing, and in combination with the opposing liquid crystal alignment substrate, fine liquid crystal alignment is achieved. It is used in displays that control orientation and change scattering, refractive index, polarization characteristics, etc., and if electrodes are provided on the substrate, a display device with rich design can be obtained. The present invention will be explained in detail below.

Substrates used in the present invention include metals, ceramics,
Inorganic materials such as glass, organic materials such as various synthetic or natural resins are used, and in addition to treatments such as coloring, scattering and reflection to control transmitted light, and absorption, conductive films such as metals or metal compounds may also be provided. can.

Furthermore, an insulating material may be evaporated or coated so as not to be affected by the base of the substrate. As the vertically oriented silicone resin applied on this base material, single or copolymers or crosslinked polymers of polymethylsiloxane, polyphenylsiloxane, silanol, etc. are used, and in particular polydimethylsiloxane as the main component is used. Various thermosetting silicones are preferably used.

There are two-component types and one-component types of thermosetting silicone, and the two-component type cures with SiOH, SiOR, SiH, and S.
This is due to a catalytic crosslinking reaction between siloxanes having reactive groups such as iCH=CH2, and crosslinking reactions such as dehydration condensation, dealcoholization condensation, dehydrogenation condensation, and addition polymerization occur. One-component curing reacts with moisture in the air to cause a condensation curing reaction, and includes deacetic acid type, deamined type, dealcoholized type, and deoxime type. These are applied to one surface of the substrate by dissolving them in a suitable solvent such as benzene or toluene, applying them by a spin coating method, dipping method, dripping method, etc., and then heating and drying. In addition, a primer may be applied to the surface of the substrate in advance to improve adhesion with the film, and examples of this primer include vinyl tri(2-methoxyethoxy) silane, 3-glycidoxypropyltritri Silanes such as methoxysilane, 3-methacryloxypropyltrimethoxysilane, N-(3-trimethoxysilylpropyl)ethylenediamine, and 3-aminopropyltriethoxysilane, or mixtures thereof, as well as partial hydrolysates or parts thereof. Co-hydrolysates are used and these are applied by conventional methods such as spin coating, rod coating, brushing, spraying, etc.

Next, the mask formed on the organosilicon layer contains various radicals generated during plasma treatment. Materials that are not significantly affected by chemical reactions, photodecomposition reactions, etc., and that do not peel off from the organosilicon surface are used. However, if the film thickness is several microns or more, plasma treatment of the silicone surface is usually performed for several tens of seconds or more. Since it is performed within a few minutes, many materials are used in the town Noh.

Examples of such materials include metals, inorganic materials, etc., as well as photoresist AZ. Commercially available photoresists such as Photoresist 0MR1T1P1R1 manufactured by Tokyo Ohka Co., Ltd., as well as many photosensitive resins and photosensitive materials with coating properties can be used. In the case of a commercially available product, it is patterned by a normal photoresist image forming method. The photoresist image can be formed by applying the photoresist solution directly onto the organosilicon layer using a conventional coating method, or by applying it onto a film of polyethylene, polyperopylene, etc., drying it, and then applying heat and pressure to the organosilicon layer. A method of transferring the image to the surface can be applied, and then petering is performed.
In the method of directly coating the organosilicone layer, the photoresist solution may be repelled by the silicone film, so it is necessary to reduce the viscosity of the photoresist solution by adding an appropriate surfactant or the like. Or ethyl cellulose,
The resist layer can be formed into a pattern by screen printing using an ink containing ethyl hydroxycellulose, acrylic resin, or the like. In this case as well, there are direct printing and transfer methods, but the transfer method is preferable because addition of a thinner reduces printing suitability. Furthermore,
The resist layer can also be formed by electrostatic printing using electrostatic photographic toner or the like as a resist material. in this case,
Since the organosilicone layer is an insulator, it is possible to form good electrostatic latent images and toner images. More simply, the film-forming resin liquid may be hand-painted or transferred by an appropriate printing means. In the present invention, plasma treatment using an inert gas such as Ar, He, or Ne, or an active gas such as oxygen or air is suitable for eliminating the vertical orientation of the surface of the organosilicone layer by plasma treatment. Plasma treatment involves (1) surface etching, (2) surface chemical modification, (3) surface crosslinking, and (4)
It is said that five types of changes (intrasurface polymerization, (5) on-surface polymerization) occur in a complex combination, but in the plasma treatment with inert gas or active gas in the present invention, electron microscopy, infrared absorption As a result of the measurements, it appears that surface etching does not occur, but chemical modification of the surface mainly occurs, that is, elimination of alkyl groups and generation of hydroxyl groups and carbonyl groups. As a result, active chemical species in the plasma state collide with the silicone surface, resulting in elimination of alkyl radicals, generation of silicon radicals, three-dimensionalization of organosilicone through crosslinking, generation of hydroxyl groups and carbonyl groups through oxidation of alkyl groups, etc. It is thought that this occurs and the silicone loses its vertical orientation. Furthermore, these reactions proceed not only on the surface of the organosilicone layer but also considerably deep inside the organosilicone layer depending on the treatment time. This is presumed to be because the organosilicone layer generally has high gas permeability, so that the active chemical species reach the inside of the layer. The low-pressure atmosphere for forming plasma active chemical species may generally be air, but Ar, Ne, He, etc.
Inert gases such as 02, N2, NH3, CO2, and active gases such as fluorinated hydrocarbon gases can be used. The plasma lipophilization treatment time varies depending on the conditions, but for example, 3×1
Under the conditions of 0-2t0rr and 300W, the vertical alignment of the organosilicone layer is effectively lost in 30 seconds or more, but if the same conditions are used for 20 minutes or more, some mask materials may deteriorate due to the etching effect, so it is preferable. do not have. next,
To remove the mask after plasma treatment, in the case of photoresist, it is undesirable to use strong acids or strong alkalis that can damage the organosilicone layer.
It is preferable to remove it with a solvent such as acetone, ethylcellolp, or toluene.

For example, Photoresist AZ manufactured by Shitsupre Co., Ltd. can be dissolved and removed using acetone, methyl ethyl ketone (MEK), etc.
TPR manufactured by Tokyo Ohka Co., Ltd. can be peeled off using ethyl cellsolp. The resist layer in screen printing can be removed with a solvent such as toluene, and the resist layer in electrostatic printing can be removed with M
It can be removed with a polar solvent such as EK. Furthermore, since the organosilicone layer generally has weak adhesion to other substances, the residual resist film can be easily removed using a suitable adhesive tape or the like. After the mask is removed, the surface of the silicone resin coating on the non-vertically oriented non-mask portions is wrapped with cloth, gauze, a brush, etc. to give aligned orientation to these portions.

In this case, wrapping may be performed on the entire surface including the vertically oriented silicone resin coating portion. This is because the vertically aligned portion maintains its vertically aligned property even if it is wrapped. Also, wrapping can be performed before removing the mask. In this case as well, wrapping can be performed on the entire surface including the mask portion. After wrapping, the mask may be removed as described above. For example, if a nematic liquid crystal having positive dielectric anisotropy is sandwiched between the thus obtained substrate having the vertical alignment portion and the horizontal alignment portion and the other alignment substrate having the horizontal alignment portion, cross nicol Below, the patterned vertical alignment appears darker and the aligned alignment appears lighter or colored.

While one side of the polarizing plate is rotated to make it a parallel Nicol, this liquid crystal changes color and brightness in various ways, and the vertically oriented portion becomes brighter, making it very suitable for display applications. Next, the present invention will be explained in more detail with reference to Examples.

Example-1 A silk screen plate was created based on a given original plate.

Next, a screen consisting of 20 parts by weight of screen oil containing ethyl cellulose and pine oil as main components and 80 parts by weight of glass frit was applied to the 90:10 copolymer film-E of polydimethylsiloxane and polydiphenylsiloxane formed on the glass plate. Print using the above silk screen plate using the ink, and after drying, under oxygen, 3 x 10-2
Plasma treatment was performed for 1 minute under the condition of t0rr300W. Next, the screen ink resist layer was peeled off with toluene and wrapped in a certain direction with gauze. After coating this with nematic liquid crystal, horizontally aligned glass substrates were stacked so that the alignment direction and the wrapping direction were perpendicular to each other, and the polarization axes were aligned with the alignment direction. When observed under crossed nicols, it was found that the plasma The untreated areas were vertically aligned and dark, while the plasma-treated areas were horizontally aligned in the wrapping direction and appeared bright. Furthermore, when the axis of one polarizing plate was gradually rotated by 90 degrees, the brightness and darkness of the image were gradually reversed. Example 2 A photoresist (TPR manufactured by Tokyo Ohka Co., Ltd.) was applied to a polypropylene film on a polysiloxane film formed on a patterned Nesa glass and dried (dry film thickness: 3μ). The surface was pressed and heated to transfer the photoresist film.

Next, after attaching a specified positive original plate, exposure and development are performed.
A resist image was formed on the polysiloxane film.

Next, after performing plasma treatment under the condition of 300W in 3×10-2t0rr1 atmosphere, the photoresist was peeled off by wrapping in a certain direction using a brush, and the vertical alignment and horizontal alignment aligned in a certain direction were patterned. An oriented substrate according to the present invention was obtained.

The alignment surfaces of this alignment substrate and a patterned Nesaglass substrate having a wrapped polyimide film on its surface are opposed to each other with a gap of 10μ so that the wrapping axes of each are perpendicular to each other, and an ester-based nematic liquid crystal is sandwiched between them. did. Next, a liquid crystal element is sandwiched between two polarizing plates so that the polarization axis coincides with the wrapping axis, and a display is obtained in which the vertically aligned area is dark and the horizontally aligned area is bright, and when a voltage is applied through the neta. , the effect of another dark pattern appearing was obtained.

Claims (1)

[Claims] 1. A silicone resin film having vertical alignment with respect to the liquid crystal is formed on the entire surface of one side of the substrate, and then a mask layer against plasma is provided in a pattern on the film, and then plasma treatment is performed, A method for producing an alignment substrate for a liquid crystal display, further comprising rubbing the surface after removing the mask layer. 2. The method for producing an alignment substrate for a liquid crystal display according to item 1 above, wherein the substrate is an electrode substrate having an electrode coating on the side on which the silicone resin coating is provided. 3. A silicone resin film having vertical alignment with respect to the liquid crystal is formed on the entire surface of one side of the substrate, then a mask layer against plasma is provided in a pattern on the film, then plasma treatment is performed, and the surface is further rubbed. A method for producing an alignment substrate for a liquid crystal display, comprising removing the mask layer. 4. The method for producing an alignment substrate for a liquid crystal display according to item 3 above, wherein the substrate is an electrode substrate having an electrode coating on the side on which the silicone resin coating is provided.