JP2968371B2 - Method for producing color filter with protective film and liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device using the method and to a production of color filters-out with protective film suitable for a liquid crystal display device or the like.

[0002]

2. Description of the Related Art Recently, it has been proposed to use a liquid crystal display device having a color filter layer formed on one substrate, a color filter protective film formed thereon, and a transparent electrode formed thereon. This makes it possible to obtain a good color liquid crystal display device having an extremely small parallax between the electrode pattern and the color filter pattern without disposing a color filter between the electrode and the liquid crystal layer.

Such a protective film can meet many silicone as a protective film for a color filter, but various things such as polyimide has been proposed is to use an epoxy resin in particular an acrylic epoxy resin as a potential candidate .

[0004]

The conventional epoxy-based color filter protective film is mainly of a two-component type. A two-component type comprising a main agent containing an epoxy group and a curing agent containing an acid is mixed. Typically, it is cured to form a protective film.

[0005] However, the protective film thus formed has high properties such as transparency and smoothing performance, but has a water absorption of 5% or more by weight, adversely affecting the liquid crystal layer and causing quality deterioration. It was possible.

[0006]

The present invention SUMMARY OF THE INVENTION is to solve the problems described above, after forming the color filter layer on a substrate, the main agent and Tashio group containing epoxy compound thereon
A curing agent comprising an acid and / or polybasic acid anhydride to form a layer of protective film-forming agent were mixed so epoxy / acid equivalent ratio is 5 or more, the layers of the protective film-forming agent, an epoxy base
An object of the present invention is to provide a method for producing a color filter with a protective film, wherein the color filter is heated and cured so that the reaction rate is 90% or less.

[0007] as a substrate in the present invention are exemplified glass, a substrate of plastic or the like. When the substrate is used for a liquid crystal display device, it preferably has properties required from the performance of the liquid crystal display device. For example, it is good if the transmission type liquid crystal display device is transparent.

The color filter layer can be formed by a conventional method. Any method can be used as long as the color filter layer can be formed, such as a dyeing method, a slurry method, an electrodeposition method, a printing method, and an evaporation method. The color filter layer is typically used such as those arranged in one or dot-like multiple colors are arranged such as RGB stripe shape is used as a liquid crystal display device, but is not limited thereto necessarily.

The epoxy compound in the present invention includes:
Various compounds reacted with epichlorohydrin to phenolic hydroxyl group-containing compound can ani gel. Such phenolic hydroxyl group-containing compound, bisphenol A, bisphenol F, tetrabromobisphenol, such novolak resin can ani gel. In addition to these, epoxy compounds having a glycidyl ether group in the polymer side chain, a suitable epoxy compounds in the protective film for a color filter can ani gel.

Examples of the polybasic acid or polybasic acid anhydride include aromatic tricarboxylic acids, aromatic tetracarboxylic acids and the like or anhydrides thereof. Examples of the polybasic acid anhydrides, mention may be made of trimellitic acid anhydride, a pyromellitic anhydride as an example.

The epoxy resin is converted into a resin according to a prescribed mixing ratio with a main agent containing an epoxy compound and a polybasic acid and / or a polybasic acid.
This is performed by weighing a curing agent containing a polybasic acid anhydride or the like, followed by mixing and curing by heating. In this document, the equivalent of an acid is, for example , one equivalent of one carboxyl group in the case of a carboxylic acid, and two equivalents of one acid anhydride group in the case of an acid anhydride .

Furthermore, the reaction rate can be used as a measure of the degree of resinification. Reaction rate in this document by the following formula
Define. Reaction rate = {1− (epoxy concentration after curing / epoxy concentration after mixing)} × 100

Factors affecting the reaction rate include the initial mixing ratio of the main agent and the curing agent, the sintering temperature, the sintering time, the amount of the curing accelerator, and the like. By adjusting these values, the reaction rate can be reduced. Can be controlled.

In the present invention, the initial mixing ratio of two-part epoxy main agent and a polybasic acid containing an epoxy compound
And / or a curing agent containing a polybasic acid anhydride , wherein an epoxy-based protective film forming agent layer is used in which the epoxy group / acid equivalent ratio is 5 or more.

[0015] That is, the applicant has by this way, in the conventional heating temperature of 180 to 250 ° C., the reaction rate of 90% or less, preferably can be obtained suppressed to 80% or less, at the same time the water absorption 3 % Has been newly found.

In this document, the water absorption is about 1 cm square, 0.3
~0.5mm thick specimen into pure water 25 ° C. are measured by weight change rate after immersion for 24 hours.

FIG. 1 is a graph showing the relationship between the reaction rate and the water absorption by converting the ratio of the main agent / curing agent to the epoxy group / acid equivalent ratio.
It is. In FIG. 1, the horizontal axis is the epoxy group / acid equivalent ratio,
The vertical axis reaction rate, is the water absorption. Here, the heating and curing temperatures are typically 220 ° C.

FIG. 1 shows that the epoxy group / acid equivalent ratio has a negative correlation with the water absorption rate and the reaction rate. If the ratio is 5 or more, the reaction rate is about 90% or less and the water absorption rate is about 3% or less. Become.

In practice, if the epoxy group / acid equivalent ratio is too large, that is, if the amount of the base material is too large, the adhesiveness and the like will be adversely affected.
It is preferably 0 hereinafter.

FIG. 2 is a diagram showing the reaction rate and water absorption when the calcination temperature is changed when the epoxy group / acid equivalent ratio is set to 7. Normal heating and curing temperature of 180 ° C to 24 ° C
It is understood that an appropriate water absorption can be obtained in the range of 0 ° C.

[0021]

[Action] In the present invention, an epoxy group, a reaction product of an acid is complex is not clear action, it generates a large atomic hydrophilic, such as a hydroxyl group or a carboxyl group as resinification advances to, by obtaining suppressed low reaction rate, absorption water rate is estimated that it is possible to obtain suppressed low.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS On an RGB stripe type electrodeposited color filter layer formed on a glass substrate, an epoxy-based color filter protective film forming agent, Optomer JSS-
7235 (manufactured by Nippon Synthetic Rubber Co., Ltd.) by adjusting the compounding ratio of the main agent and the curing agent, and adjusting the epoxy group / acid equivalent ratio to 5.6 , 7 , and 8.
4 , 9.8 as a 3 μm coating with a spin coater
It is reacted at 220 ° C., to form a-out with protective film color filters.

The reaction rate and the water absorption of the protective film of the obtained color filter were measured, and the results are as shown in FIG. 1. All were good with a water absorption of 3% or less.

[0024] The a patterned transparent electrode made of indium tin oxide (ITO) on top of-out with protective film color filter is formed, also a glass substrate having a transparent electrode made of patterned ITO, the transparent electrode side Were made to face each other, the periphery was sealed with a sealing material, and liquid crystal was sealed inside. Further, a driving device for applying a voltage was connected between the transparent electrodes.

The obtained color liquid crystal display device was a good one with little change over time due to driving.

[0026]

According to the present invention, a color filter and a liquid crystal display device can be obtained with a highly reliable protective film having a low water absorption of the protective film. In addition , there is also an effect of improving resistance to chemicals used during a manufacturing process of a liquid crystal display element or the like, particularly to an alkali solution.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the epoxy group / acid equivalent ratio and the water absorption.

FIG. 2 is a graph showing the relationship between heating and curing temperatures and water absorption.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-128802 (JP, A) JP-A-4-170421 (JP, A) JP-A-4-170503 (JP, A) JP-A-4-170503 170504 (JP, A) JP-A-4-133001 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02B 5/20 101

Claims (3)

(57) [Claims] A color filter layer is formed on a substrate, and then a main agent containing an epoxy compound, a polybasic acid and
/ Or a curing agent comprising a polybasic acid anhydride to form a layer of protective film-forming agent were mixed so epoxy / acid equivalent ratio is 5 or more, the layers of the protective film-forming agent, of an epoxy group method for producing-out with protective film color filters, characterized in that the reaction rate <br/> is cured by heating to be less than 90%. 2. A color filter layer formed on a substrate.
In addition, a main agent containing an epoxy compound and a polybasic acid and
And / or a curing agent containing a polybasic acid anhydride and an epoxy group / acid
Of the protective film forming agent mixed so that the equivalent ratio becomes 5 to 10.
A layer is formed, and the layer of the protective film forming agent is reacted with an epoxy group.
Heat curing so that the rate becomes 58-90%.
A method of manufacturing a color filter with a protective film. 3. A color filter manufactured by the manufacturing method according to claim 1 or 2 as at least one of the pair of substrates, wherein a liquid crystal layer is sandwiched between the two substrates. Liquid crystal display element.