JPH04115202A - Formation of transparent protective layer - Google Patents

Abstract

PURPOSE:To inexpensively form a protective layer having an excellent adhesive property, flatness and transparency by laminating a transfer sheet provided with a transparent photosensitive resin layer which is a protective layer precursor on a base onto the multicolor images formed on a substrate and exposing this protective layer precursor via a prescribed mask, then developing the precursor. CONSTITUTION:The transfer sheet is obtd. by applying a transparent photosensitive resin on polyethylene terephthalate (PET) and drying the coating. On the other hand, this transfer sheet with its transparent photosensitive resin layer positioned on the inner side is superposed on the color filters formed by a photolithographic method, printing method, etc., on the transparent substrate and is then laminated. The PET is peeled to transfer the transparent photosensitive resin layer on the color filters. The resin layer is in succession exposed via the prescribed mask by a prescribed quantity and the unnecessary parts are removed by development. Consequently, the ruggedness between the relief patterns are completely filled with the transparent protective material and the layer having the extremely good flatness on the front surface is formed. The substrate is thereafter heated and the transparent protective layer completely cured with the flat layer is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for forming a transparent protective layer on a multicolor pattern formed on a substrate, such as a color filter or a multicolor color display. .

``Prior Art'' Conventionally, in order to form a protective layer on a multicolor pattern such as a color filter, a method of dissolving acrylic resin, polyurethane resin, polyimide resin, etc. in a solvent and applying it has been used. It was mainstream.

However, this method may destroy the pattern depending on the material forming the color pattern, and it is not sufficient to meet the requirements, especially when a protective layer with good final flatness is required, such as in a color filter. It wasn't something I could answer.

On the other hand, a technique is disclosed in JP-A-1-262502 and JP-A-2-191902 in which a resin that has been formed into a film on a support is thermocompressed onto a colored layer to form a protective layer. In the latter case, the atmosphere is further reduced in pressure during crimping.

Also, for example, due to requests for connection of driver units, etc., maintenance is possible! There is a desire to remove unnecessary portions of the layer and leave only the necessary pattern, but in order to meet this request, complicated operations such as photoresist formation and etching are required.

Furthermore, a method of thermocompression-bonding a pre-patterned resin layer is also disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 1-262502, but this method leaves concerns about the accuracy of the transfer position.

``Problem to be Solved by the Invention'' An object of the present invention is to provide a color filter, a multicolor color display, etc., which has excellent adhesion to a color pattern, on a multicolor color pattern formed on a support, such as a color filter or a multicolor display. It is an object of the present invention to provide a method for inexpensively producing a matte bag that has high flatness and transparency and can be turned back if necessary.

``Means for Solving the Problems'' The purpose of the present invention is to: ① transfer a transfer sheet, in which a transparent photosensitive resin layer, which is a protective layer precursor, is provided on a support, onto a multicolor image formed on a substrate; The process of laminating.

(2) A step of exposing the protective layer precursor to light through a predetermined mask and then developing it.

This was achieved by a method for forming a transparent protective layer characterized by comprising:

In the above step (2), the exposure may be carried out through the support if the support is transparent, but from the viewpoint of resolution it is preferable to peel off the support before exposure. It is natural to remove the support before development.

Further, after the step (2), a heating and/or full-surface exposure step can be added to increase the strength of the formed pattern.

Next, the materials used in the present invention will be explained in detail.

In the present invention, the term "protective layer precursor" refers to a layer that does not satisfy mechanical strength, adhesion resistance, and solvent resistance when the transferred layer is in its original state, and when laminated into a multicolor image. has sufficient flexibility and adhesion to multicolor images even at room temperature, and exhibits sufficient mechanical strength, adhesion resistance, and solvent resistance through subsequent treatments such as exposure and heating. Refers to something that has the ability to form a pattern through exposure and development.

One of the typical materials having such a function is a NECA-type photosensitive resin composition. As a negative photosensitive resin composition that can be used in the present invention, Japanese Patent Application No. 2-82
262, a photosensitive resin composition comprising a negative photosensitive diazo resin and a binder, a photopolymerizable composition, a photosensitive resin composition comprising an azide compound and a binder, a cinnamic acid type photosensitive resin, or a patent application. List the photopolymerizable compounds obtained by sequentially reacting (1) an epoxy compound with a specific structure, (2) an unsaturated monocarboxylic acid, and (3) a polybasic acid anhydride, as described in Hei 2-161055. I can do it.

Various methods can be used to form multicolor images on a substrate. To create a color filter, for example, there is a method described in Japanese Patent Application No. 2-82262, and to create a color display, for example, there is a method described in Japanese Patent Application Laid-open No. 59-9.
The method disclosed in No. 7140 can be used. In these methods, a color pattern is formed on a photopolymerizable resin composition provided on a substrate, and then a polymerizable amount of light is irradiated to protect the color pattern. It is also possible to form color patterns directly.

As these substrates, glass, flexible plastic films (polyethylene terephthalate, triacetyl cellulose, etc.), and more rigid plastic plates (acrylic, polycarbonate, etc.) can be used depending on the purpose.

A flexible plastic film can be used as a support for holding the protective layer precursor. If a transparent support is desired, a polyethylene terephthalate film having a thickness of about 30 to 200 cm is preferred.

When developing the protective layer precursor after pattern exposure,
A system that does not use an organic solvent as a developer is preferred. As such a system, a composition containing an alkali-soluble organic high polymer as a binder, a monomer having an ethylenically unsaturated bond, and a photopolymerization initiator is preferable.

When the protective layer does not need to be patterned, the protective layer precursor can be exposed over the entire surface to form a multicolor image-protected FiN. After that, the support may be removed, but for applications such as color displays that require weather resistance, it is preferable to leave it as is or protect it using another substrate.

"Examples" The present invention will be explained in more detail below using Examples, but the present invention is not limited to these two examples.

Example Polyethylene terephthalate (PE) with a thickness of 10,071 m
A transparent photosensitive resin (CT manufactured by Fuji Hunt Electro Technology Co., Ltd., a transparent photosensitive resin containing a polymer binder, a photopolymerizable monomer, a photopolymerization initiator, and a thermal polymerization inhibitor as main components) was applied on top of T) and dried ( A transfer sheet was obtained with a film thickness of 2 μm).

On the other hand, photolithography (for example, JP-A-1-1-1
02429), printing methods (for example, Japanese Patent Application Laid-Open No. 63-12
9303), staining methods (e.g. Japanese Patent Application Laid-Open No. 60-216
306), etc., on top of the color filter created by
The transparent photosensitive resin layer was stacked on the inside, and then, using a laminator (VP-II type I) manufactured by Taisei Laminator Co., Ltd., the heating temperature was 130°C and the roller pressure was 2 Kg/cm 2
Lamination was carried out under the transfer conditions of , transport speed 0.3 m/min, PET was peeled off, and a transparent photosensitive resin layer was transferred onto the color filter. As it is, heat resistance,
Although it could not be a transparent protective layer in terms of solvent resistance, etc., this transparent photosensitive resin layer was modified into a transparent protective layer in the next step.

Next, a predetermined amount of light is exposed through a predetermined mask, and development (C
A 1% aqueous sodium carbonate solution was used as a developer for T) to remove unnecessary parts.

As a result, the unevenness between the relief patterns was completely filled with the transparent protective material, and the flatness of the top surface was excellent (±0.03 μm, >N was not formed on the relief pattern or at any part). Ta.

Thereafter, it was heated at 250° C. for 1 hour to completely harden the flat layer, resulting in a transparent and preserved FiN. Even at this point, the flatness did not change.

Further, an ITO film was formed on the protective layer by sputtering, and the IT○ film was patterned by photolithography and etching. Furthermore, an alignment film was formed on the ITO film using a polyimide precursor to obtain a color filter device for a color filter liquid crystal. At that time, the transparent protective layer obtained as described above has good sputtering resistance of the IT○ film, and the solvent used for the cloth, etching, and alignment film, alkali, acid, N-methyl It had sufficient resistance to solvents such as pyrrolidone and γ-butyrolactone.

[Effects of the Invention] According to the method of forming a protective layer on a multicolor image according to the present invention,
Since the photosensitive resin layer is formed by transferring from a transfer sheet, the resin layer, which is the precursor of the protective layer, is softened by heating and pressing effects, and penetrates into the unevenness of the base, creating a form that absorbs the unevenness of the base. It is transcribed by . Further, through exposure and development steps, unnecessary portions are removed and cured, forming a bonded FiN with very good flatness. Particularly when producing a liquid crystal panel, it is effective for gap regulation and has a great effect on panel performance and yield improvement. Further, since patterning can be performed by exposure and development, it is possible to form a protective layer having an arbitrary pattern with good positional accuracy.

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Claims (2)

[Claims] (1) A step of laminating a transfer sheet, in which a transparent photosensitive resin layer, which is a protective layer precursor, is provided on a support, onto a multicolor image formed on a substrate; (2) exposing the protective layer precursor to light through a predetermined mask;
A method for forming a transparent protective layer, the method comprising: a subsequent step of developing.