JP2807510B2 - Method for manufacturing transfer sheet and liquid crystal display element - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a transfer sheet and a liquid crystal display device, and more specifically, to provide a liquid crystal display device with high precision and a large screen easily and economically. The present invention relates to a transfer sheet that can be used and a method for manufacturing a liquid crystal display element using the transfer sheet.

(Conventional technology and its problems) Conventionally, mono-color and multi-color liquid crystal display devices using liquid crystal have been widely used for digital display and image display of, for example, clocks, calculators, word processors, personal computers, and televisions. .

The liquid crystal display element has a pair of electrodes, at least one of which is transparent, formed between a pair of glass substrates, at least one of which is transparent. The liquid crystal is sealed in the structure.

In manufacturing the liquid crystal display element, an electrode layer, a color filter, and a crystal are formed on a glass substrate by a photo-etching method, a coating method, a printing method, or the like for each of the substrates. Since high precision is required for the formation, there is a problem that defective products are easily generated and the productivity is low.

Further, as the liquid crystal display device has a larger screen, higher accuracy is required, and as a result, it is technically very difficult to provide a large screen liquid crystal display device.

In addition, as a result of poor yield, the generation of defective products wastes expensive glass substrates, resulting in high costs.

Furthermore, as a result of using glass as a substrate, there is a problem that it is very difficult to form a liquid crystal display element having a complicated curved surface shape.

Accordingly, an object of the present invention is to provide a transfer sheet and a method of manufacturing a liquid crystal display element that can easily and economically provide a liquid crystal display element with high precision and a large screen by solving the above-mentioned problems of the prior art. That is.

(Means for Solving the Problems) The above object is achieved by the present invention described below.

That is, the present invention provides a transfer sheet characterized in that a peelable substrate sheet, an electrode layer, a liquid crystal polymer layer, an electrode layer and an adhesive layer are laminated in the order described in this description, A method for manufacturing a liquid crystal display element, which comprises bonding to a display element substrate and then peeling off the base sheet.

(Function) A transfer sheet having a peelable substrate sheet, an electrode layer, a liquid crystal polymer layer, an electrode layer, and an adhesive layer laminated in the order described above is adhered to a substrate for a liquid crystal display element. By peeling off, the liquid crystal display element can be easily and economically provided with high accuracy and a large screen.

(Preferred Embodiment) Next, the present invention will be described more specifically with reference to preferred embodiments.

In the transfer sheet of the present invention, as shown schematically in FIG. 1, a cross-section of the transfer sheet according to the present invention includes a releasable substrate sheet 1, an electrode layer 2, a liquid crystal polymer layer 3, an electrode layer 4, and an adhesive layer 5 in this order. It is characterized by being laminated.

Examples of the base sheet 1 include paper such as paper, processed paper, and synthetic paper;
Polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer, polyolefin such as polyethylene, polypropylene, polymethylpentene, plastic sheet such as polyvinyl chloride, polycarbonate, polyimide, polyacetal, polyarylate or the like. Although a laminate or the like is optionally used, a preferable one is an inexpensive polyethylene terephthalate film which has excellent dimensional accuracy with respect to changes in heat and temperature and is inexpensive.

These base sheets 1 may have any thickness, but the preferred thickness is in the range of 5 to 100 μm. It is preferable that the surface of these base sheets 1 is subjected to a release treatment. For example, a thin release is performed on the surface of the base sheet 1 using a release agent such as wax, silicone oil, silicone resin, melamine resin, fluorine resin, or polyolefin resin. It is preferable that the layer 6 is formed.

The electrode layer 2 formed on the substrate surface is made of aluminum, silver,
It is made of a conductive material such as gold, tin oxide, indium oxide, and ITO, and is formed in a matrix by a known photoetching method, printing method, or the like. Particularly preferred electrode layer 2 is formed of transparent tin oxide or ITO to a thickness of 0.2 to 0.3 μm.

When the transfer sheet of the present invention is a transfer sheet for a color display, R, G, B
Is formed. The color filter 7 is also formed by a known photo-etching method, a dyeing method, a printing method, or the like, and has a preferable thickness of 0.1 to 10 μm.
It is. In the case of a mono color, the formation of the color filter 7 is not essential.

The liquid crystal polymer layer 3 formed on the electrode layer 2 or the color filter 7 is formed from a conventionally known liquid crystal polymer for a liquid crystal display device. Conventionally, these liquid crystal polymers have liquid crystal molecules bonded as side chains of an acrylic or siloxane-based polymer, and are represented by the following structural formula, for example.

The above example is one example, and any other known liquid crystal polymer can be used in the present invention. These liquid crystal polymers may be liquefied by heating or suitable solvents, for example, alcohol solvents such as isopropanol, acetone, ketone solvents such as methyl ethyl ketone, toluene,
Glass beads 8 and glass fibers with a constant spherical diameter for spacers are mixed and dispersed in an ink or paint made with an aromatic solvent such as xylene or an ester solvent such as ethyl acetate or butyl acetate, and coated. It is formed to a thickness of 5 to 10 μm by a method or a printing method. The shape to be printed is
In addition to patterns such as numbers, characters, and figures, solid shapes may be used.

Of course, these inks containing a liquid crystal polymer have a certain degree of fluidity at the time of printing.
Alternatively, frame printing (not shown) can be performed on the color filter 7 with an appropriate ink.

Also, when forming the liquid crystal polymer layer, in order to align the initial alignment direction of the liquid crystal groups of the liquid crystal polymer, oblique vapor deposition of silicon oxide or an oriented polyimide film is performed, and annealing is performed at about the isotropic phase transition temperature for several hours. preferable.

The liquid crystal polymer layer 3 may be mixed with a dichroic dye (not shown) having a host-guest relationship with the liquid crystal polymer to form the liquid crystal polymer layer 3 for color display.

Further, since the liquid crystal polymer layer 3 has a high viscosity, the response speed may be slow at around room temperature. In this case, an electric field is applied by applying a temperature bias to around an isotropic phase transition temperature during use. Is preferred.

The electrode layer 4 formed on the liquid crystal polymer layer 3 may be the same as the electrode layer 2, but it is necessary that at least one of the electrode layers 2 and 4 is a transparent electrode.

The mounting agent layer 5 formed on the electrode layer 4 can be formed from various materials. Examples of the adhesive layer 5 include a pressure-sensitive adhesive such as used in a well-known pressure-sensitive adhesive sheet and the like, and a heat-sensitive adhesive. Agents, ionizing radiation-curable adhesives and the like. The operation of the adhesive is convenient, but the stability such as adhesive strength is not sufficient,
The most preferable adhesive is an ionizing radiation-curable adhesive because heat-sensitive adhesive requires heating at the time of transfer, and there is a concern about accuracy due to expansion and contraction of each layer due to heat.

The ionizing radiation-curable adhesive is a component having a polymerizable double bond in the adhesive, for example, includes monomers and oligomers such as various acrylates, and optionally includes a photopolymerization initiator, for example, It is polymerized and cured by irradiation with ultraviolet rays or electron beams to exhibit adhesiveness.

Various types of ionizing radiation-curable adhesives are known per se. Examples thereof include those which are liquid before curing by a monomer or a solvent, and those which form a solid film at room temperature by evaporation of the solvent after application. Any of known compounds can be used in the present invention.

In the present invention, an ionizing radiation-curable adhesive which is liquid when used and contains a solvent, and forms a substantially solid layer after application by evaporation of the solvent is particularly preferred. That is, by using the adhesive, heating is not required at the time of applying the adhesive, and it is possible to perform low-temperature drying and winding up at the time of drying, and further, heating is not required at the time of transfer, No misregistration occurs due to expansion and contraction of each layer due to heating and cooling.

The use of such an adhesive has a remarkable effect that the material to be transferred as the substrate for a liquid crystal display element is not limited to glass, and a plastic sheet or film having low heat resistance can be used.

However, when such an adhesive is used, the base sheet 1 is preferably transparent to ionizing radiation.
However, when the ionizing radiation is irradiated from the side of the material to be transferred, which is the substrate, it is not essential that the substrate sheet is transparent.

When the adhesive layer 5 of the transfer sheet configured as described above is made of an adhesive, it is preferable that the release paper 9 is adhered to the adhesive layer 5.

The method of manufacturing a liquid crystal display element of the present invention uses the above-mentioned transfer sheet of the present invention. As shown schematically in FIG. The method is characterized in that the layers 5 are opposed to each other and bonded, and then the base sheet 1 is peeled off.

As an example of the substrate 20 used in the present invention, a glass substrate widely used in a conventional liquid crystal display element can be used as it is, and a polyacrylate, polyester, polystyrene, polycarbonate or other highly transparent sheet or film can also be used. It can be used, in particular, these plastic substrates may have more complex shapes on their surface. The preferred thickness of the substrate as described above is about 50 to 1000 μm.

When the adhesive layer 5 is made of an adhesive, the release paper 9 is peeled off as necessary, the adhesive layer 5 is adhered to the substrate 20, and the transfer is completed by peeling the base sheet 1.
When the adhesive layer 5 is made of a heat-sensitive adhesive, the adhesive layer 5 is stacked on the substrate 20 so as to face the substrate 20, and then the adhesive 5 is activated by applying necessary pressure and heat. Thereafter, the transfer is completed by peeling the base sheet 1. When the adhesive layer 5 is made of an ionizing radiation-curable adhesive, the adhesive
By irradiating ultraviolet rays or electron beams (arrows) from the side or the base sheet 1 to activate the adhesive layer 5 and then peeling the base sheet 1, transfer is completed, and a desired liquid crystal display element is provided. Is done.

(Effects) According to the present invention as described above, various problems of the prior art can be solved, and a liquid crystal display device can be easily and economically provided with high accuracy and a large screen.

[Brief description of the drawings]

FIG. 1 and FIG. 2 are diagrams schematically illustrating a transfer sheet and a method of the present invention. 1: Base material sheet, 2: Electrode layer 3: Liquid crystal layer, 4: Electrode layer 5: Adhesive layer, 6: Release layer 7: Color filter, 8: Spacer 9: Release paper, 20: Substrate

Claims (9)

(57) [Claims] 1. A transfer sheet comprising a releasable substrate sheet, an electrode layer, a liquid crystal polymer layer, an electrode layer, and an adhesive layer laminated in this order. 2. The transfer sheet according to claim 1, wherein at least one of the electrode layers is transparent. 3. The transfer sheet according to claim 1, further comprising a color filter. 4. The transfer sheet according to claim 1, wherein the adhesive layer comprises an ionizing radiation-curable adhesive. 5. The transfer sheet according to claim 4, wherein the ionizing radiation-curable adhesive is solid at room temperature. 6. A transfer sheet having a peelable substrate sheet, an electrode layer, a liquid crystal polymer layer, an electrode layer, and an adhesive layer laminated in the order described above is adhered to a substrate for a liquid crystal display element. A method for manufacturing a liquid crystal display element, comprising separating a material sheet. 7. The method according to claim 6, wherein the adhesive layer comprises an ionizing radiation-curable adhesive. 8. The method according to claim 7, wherein the ionizing radiation-curable adhesive is solid at room temperature. 9. The method according to claim 6, wherein the substrate is a plastic sheet or a film.