JPH07174591A - Display panel manufacturing method - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a method for producing a display panel which has excellent adhesion between an image and a substrate, has no discoloration or fading, and has excellent durability. [Structure] After forming a photopolymerizable adhesive layer and an image pattern provided on a substrate, the image pattern or the image pattern is formed.
The photopolymerizable transparent resin layer provided on the laminated image layer is formed of a photopolymerizable adhesive layer composition and a photopolymerizable transparent resin layer composition each containing an acylphosphine oxide photopolymerization initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an instrument panel for various devices, a display panel on which a map or a landscape is arranged, a dial for a speedometer for a vehicle, and the like.

[0002]

2. Description of the Related Art Conventionally, a colored image is formed on an instrument panel of various devices in which a predetermined colored image is formed on a support, a display plate on which a map or a landscape is arranged, a dial of a vehicle speed meta, etc. The printing method is used, especially, the screen printing method, the offset printing method, etc. are used. In recent years, the quality and diversification of products have advanced, and the decorativeness and visibility of the colored image have been improved. Among the demands, in the screen printing method, it is necessary to adjust the viscosity of the ink, and to dry and cure the ink, which requires a lot of work.

Further, in the screen printing method, since the printing ink remains on the plate, it is necessary to wash the plate with a solvent, which requires a lot of work.

The offset printing method has a drawback that the color density required for the display panel cannot be obtained because the ink coating cannot be thickened.

As an alternative to the above printing method, for example,
A method for obtaining an image by forming an image by exposure and development using an image forming sheet having a photopolymerizable colored layer and then transferring the image to the image receiving layer by applying heat and pressure is disclosed in JP-A-47-4183.
No. 0 and Japanese Patent Laid-Open No. 48-93337.

Further, Japanese Patent Application Laid-Open No. 59-97140 discloses that
A colored image of each color is exposed and developed to form a colored image of each color in advance, which is sequentially transferred to an image receiving sheet provided with a photopolymerizable receiving layer to form a colored image on the receiving layer. Is disclosed, and a method of finally transferring this together with the receiving layer to a support is disclosed.

Since the image is covered with the photopolymerizable image-receiving sheet in the above-mentioned manufacturing method, there is an advantage that residual tack and damage on the surface can be prevented. The photopolymerization initiator of the sheet is
It is colored and has a defect that the coloration of the image-receiving sheet (yellowing: it becomes yellow) becomes severe over time after curing.

In order to solve the above drawbacks, Japanese Patent Laid-Open No. 61-
Japanese Patent Publication No. 200535 discloses the use of a benzyldialkyl ketal as a photopolymerization initiator,
High sensitivity is also achieved by using this.

However, even the above-mentioned photopolymerization initiator shows considerable yellowing due to aging, in particular, photodegradation.

Further, as another method for producing a display board, for example, an image is formed by using an image forming sheet, the image is transferred onto a substrate provided with a photopolymerizable resin layer, and then the image is formed. Japanese Patent Laid-Open No. 2-210220 discloses a method of manufacturing a display board having good durability by laminating a transparent photopolymerizable resin layer on the above.

However, in the above method of manufacturing the display board, since the developed image is transferred to the substrate, the adhesion between the substrate and the image is not sufficient, and peeling and floating easily occur. Further, during use, discoloration of an image due to sunlight or a fluorescent lamp, fading, and discoloration of a photopolymerizable resin layer due to exposure to ultraviolet rays during a manufacturing process were observed.

Further, as an initiator having little yellowing and high sensitivity, Japanese Patent Publication No. 63-40799 discloses an acylphosphine oxide compound such as benzoyldiphenylphosphine oxide and a method for using the same.
According to this, as compared with the benzyldialkyl ketal, a considerable reduction in yellowing and an increase in the curing rate are achieved. However, the usage here is a usage in a photopolymerizable material (particularly, coating material for coating, varnish, printing ink, recording material), and other usage is not specifically disclosed. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is excellent adhesion between an image and a substrate, no discoloration or fading, and durability. It is to provide a manufacturing method of an excellent display panel.

[0013]

[Means for Solving the Problems]

Examples of the substrate used in the present invention include plate-shaped members such as acrylic resin, polycarbonate resin, polyethylene terephthalate; glass plate; ceramic plate; metal plate and the like.

The above-mentioned substrate may be subjected to a primer treatment or may be colored for the purpose of improving the adhesion to the photopolymerizable adhesive layer, but if it is transparent, it will be described later. The whole surface exposure can be performed through the substrate.

The photopolymerizable adhesive layer used in the present invention is formed from a photopolymerizable adhesive layer composition containing an acylphosphine oxide photopolymerization initiator.

Examples of the photopolymerizable adhesive layer composition include (a) 100 parts by weight of an organic polymer, (b) 10 to 200 parts by weight of a photopolymerizable unsaturated compound, and (c) an acylphosphine oxide-based composition. A composition comprising 0.1 to 10 parts by weight of a photopolymerization initiator is preferably used.

The organic polymer (a) is preferably a polymer having an α, β-unsaturated ethylenic monomer as a constituent component,
Examples of the α, β-unsaturated ethylene-based monomer include styrene, o-methylstyrene, m-methylstyrene, p
-Methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-hexylstyrene, p-octylstyrene, p-methoxystyrene,
Styrenes such as p-phenylstyrene, 3,4-dimethylchlorostyrene; α-vinylnaphthalene; ethylene, propylene, butylene or C _{5 to} C ₃₀ and higher α-olefins; vinyl chloride, vinyl bromide, etc. Vinyl halides; vinyl acetate, vinyl propionate, vinyl butyrate and other vinyl esters; methyl (meth) acrylate, propyl (meth) acrylate, (meth)
Butyl acrylate, isobutyl (meth) acrylate,
Octyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-chloroethyl (meth) acrylate, α-chloro (meth)
(Meth) acrylic acid esters such as methyl acrylate, phenyl (meth) acrylate, dimethylaminoethyl (meth) acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether; vinyl methyl ketone, vinyl ethyl ketone, etc. Vinyl ketones; N-
N-vinyl compounds such as vinylpyrrole and N-vinylindole; and (meth) acrylonitrile and (meth) acrylic acid amides, which may be used alone or in combination of two or more. Good.

If the weight average molecular weight of the organic polymer (a) is small, so-called cold flow is likely to occur, and after the photopolymerizable adhesive layer or the photopolymerizable transparent resin layer is formed, it is wound into a roll. When stored, wrinkles are easily formed in the photopolymerizable adhesive layer or the photopolymerizable transparent resin layer, and when large, when the photopolymerizable adhesive layer or the photopolymerizable transparent resin layer is formed by coating from the photopolymerizable resin composition, Since the solution viscosity is high and coating unevenness is likely to occur, it is preferably 20,000 to 1,000,000, more preferably 50,000 to 500,000.

As the photopolymerizable unsaturated compound (b), various (meth) acrylic acid derivatives are preferable, and examples thereof include triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate and nonaethylene. Glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, nonapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol- Rutri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate
G, dipentaerythritol-penta (meth) acrylate
Dipentaerythritol hexa (meth) acrylate
G, trimethylolpropane tri (meth) acrylate
, Ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [ 4- (methacryloxydiethoxy) phenyl] propane, 3-phenoxy-2-propanoyl acrylate,
Polyfunctional monomers such as 1,6-bis (3-acryloxy-2-hydroxypropyl) hexyl ether; monofunctional monomers such as methyl (meth) acrylate and benzyl (meth) acrylate; urethane and Examples thereof include acrylate oligomers of polyester, and these may be used alone or in combination of two or more kinds.

When the amount of the above-mentioned photopolymerizable unsaturated compound added is small, the adhesiveness to the substrate when the photopolymerizable adhesive layer is formed is deteriorated, and when it is too large, cold flow or bleeding occurs, so that the above organic compound is used. Polymer (a) 10
It is limited to 10 to 200 parts by weight, and more preferably 30 to 180 parts by weight, relative to 0 parts by weight.

The acylphosphine oxide photopolymerization initiator (c) used in the present invention has the property of activating the unsaturated compound (b) by actinic rays such as ultraviolet rays and visible rays to initiate polymerization. For example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BA
Manufactured by SF, trade name: Lucillin TPO), pivaloyldiphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, terephthaloyl-bis-diphenylphosphine oxide, 1-methyl-cyclohexylcarbonyldiphenylphosphine oxide, versatoyldiphenylphosphine oxide, 4 -Methylbenzoylphenylphosphinic acid methyl ester, 2,4,6
-Trimethylbenzoylphosphinic acid diethyl ester, etc., may be used alone or in combination of two or more kinds.

The above-mentioned acylphosphine oxide-based photopolymerization initiator (c) may be used together with a photopolymerization initiation aid composed of an amine compound for the purpose of accelerating the polymerization rate or reducing oxygen inhibition. It is also possible to use together with the photopolymerization initiator or the photopolymerization initiation auxiliary agent.

Examples of the photopolymerization initiation aid include triethanolamine and dialkylaminobenzoic acid esters, and examples of the photopolymerization initiator include sulfides such as dibenzothiazoyl monosulfide and 4 A thioxanthone derivative such as diethylthioxanthone, a diazo compound such as benzenediazonium, an aromatic carbonyl compound such as benzyldimethylketal, an acetophenone derivative such as α-hydroxy-α, α′-dimethyl-acetophenone, and a peroxidase such as dicumyl peroxide. Oxides, acridine derivatives such as benzacridine, phenazine derivatives such as 9-methylbenzphenazine, 4,4 ', 4 "-trimethoxy-2,
Examples include quinoxaline derivatives such as 3-diphenylquinoxaline, 2,4,5-triphenylimidazoyl dimer, halogenated ketone, and 2,4,6-tris (trichloromethyl) -1,3,5-triazine. .

When the amount of the photopolymerization initiator (c) added is small, the curing time becomes long, the curing becomes insufficient, and the residual amount of the photopolymerizable unsaturated compound increases, and the weather resistance with time elapses. Is deteriorated, the adhesiveness to the substrate is reduced, and the cured resin becomes yellowed and becomes brittle when the amount is increased. Limited to parts by weight.

The thickness of the above-mentioned photopolymerizable adhesive layer is preferably 1.0 to 30 μm, more preferably 3.0 to 20 μm because the adhesiveness becomes insufficient as the thickness becomes thin and the curing becomes insufficient as the thickness increases. is there.

The photopolymerizable transparent resin layer used in the present invention is formed from a photopolymerizable transparent resin layer composition containing an acylphosphine oxide type photopolymerization initiator.

The above photopolymerizable transparent resin layer composition includes
The same thing as the said photopolymerizable adhesive layer composition can be used.

The photopolymerizable adhesive layer composition and the photopolymerizable transparent resin layer composition used in the present invention may be the same or different.

The thickness of the above-mentioned photopolymerizable transparent resin layer is preferably 0.1 to 50, more preferably 1 to 30 μm, because the durability of the image cannot be obtained when it becomes thin and the curing becomes insufficient when it becomes thick. is there.

The photopolymerizable resin colored layer used in the present invention is, for example, a linear polymer, a photopolymerizable unsaturated compound,
It is preferably composed of a photopolymerization initiator and a colorant, and if necessary, a plasticizer, a thermal polymerization inhibitor, an antioxidant, a stabilizer,
It is preferably produced from a photopolymerizable coloring composition to which an ultraviolet absorber or the like is added.

The above linear polymer is, for example, a copolymer of an α, β-unsaturated ethylenic monomer containing a carboxyl group and an α, β-unsaturated ethylenic monomer not containing a carboxyl group. Is preferable, and as the α, β-unsaturated ethylenic monomer containing a carboxyl group, for example,
Unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid and itaconic acid may be mentioned, and these may be used alone or in combination of two or more kinds. Good.

The α, β-unsaturated ethylenic monomer containing no carboxyl group may be any one that can be copolymerized with the above-mentioned α, β-unsaturated ethylenic monomer containing a carboxyl group. The α, β-unsaturated ethylenic monomer constituting the organic polymer (a) can be selected and used. These may be used alone or in combination of two or more kinds. May be.

When the content of the α, β-unsaturated ethylenic monomer containing a carboxyl group in the above linear polymer becomes small, it becomes difficult to dissolve it in an alkali developing solution, and the developability deteriorates. It becomes difficult to dissolve in a working solvent, the thickness accuracy is reduced, and the resolution of the image on the display panel is reduced.
Weight% is preferable, and 15 to 35 weight% is more preferable.

If the weight average molecular weight of the above linear polymer is small, wrinkles are easily formed in the photopolymerizable resin colored layer during storage, and if it is large, it is difficult to dissolve in an alkaline solution and the developability is deteriorated. ˜500,000 is preferable, and more preferably 50,000 to 300,000.

The photopolymerizable unsaturated compound in the photopolymerizable resin coloring composition may be any one having a property that polymerization is initiated by actinic rays. For example, it is used in the photopolymerizable adhesive layer composition. The same as the photopolymerizable unsaturated compound (b) can be mentioned.

If the amount of the above-mentioned photopolymerizable unsaturated compound added is small, the curing of the photopolymerizable resin colored layer will be insufficient, and if it is too large, the tackiness of the unexposed portion will be strong and the image forming property will be deteriorated. It is preferably 10 to 200 parts by weight, and more preferably 3 to 100 parts by weight of the linear polymer.
0 to 150 parts by weight.

The photopolymerization initiator may be any one that initiates the polymerization of the photopolymerizable unsaturated compound by actinic rays. For example, the photopolymerization initiator used in the photopolymerizable adhesive layer composition ( ), The photopolymerizable resin colored layer is insufficiently cured and the image forming property is deteriorated when the addition amount is small, and when the addition amount is large, the photopolymerizable resin colored layer is yellowed or brittle. Therefore, the above linear polymer 100
0.1 to 10 parts by weight is preferable with respect to parts by weight.

The above colorants are used for imparting a hue of yellow, magenta, cyan, black or the like to an image forming sheet described later.
Known pigments can be used. For example, as yellow pigments, Hansa yellow, benzidine yellow,
Examples thereof include cadmium yellow, yellow lead, zinc chromate, lemon yellow, strocian yellow, isoindolino yellow and indian yellow, and magenta pigments include rhodamine B lake, cadmium red, Examples thereof include red iron oxide, chrome bar million, pyrazolone red, lisole red, red lead, quinacridone red, and watching red.The cyan pigments include ultramarine blue, prussian blue, cobalt blue, cerulean blue, and mangany. Examples of the black pigments include carbon black and phthalocyanine blue.
Examples include titanium black and iron black.

The above-mentioned pigments may be used alone or in combination of two or more colors. For example, yellow-based pigments, magenta-based pigments and black-based pigments are mixed to produce an image forming sheet having a brown hue. can do.

When the amount of the colorant added is small, the coloring is not sufficient, and when the amount is large, the photopolymerizable resin colored layer becomes brittle.
1 to 300 parts by weight is preferable.

The thickness of the photopolymerizable resin colored layer is not particularly limited, but if it is thin, a sufficient image density cannot be obtained, and if it is thick, a step is generated in the image portion, so 0.5 to 20 μm is preferable, and more preferable. Is 1.0 to 10 μm.

As the method for forming the photopolymerizable adhesive layer on the substrate in the production method of the present invention, for example, a coating solution obtained by dissolving the photopolymerizable adhesive layer composition in a solvent is coated. With the method of coating directly on the substrate, by drying, by coating the above coating solution on the support film, and drying to create an adhesive layer sheet provided with a photopolymerizable adhesive layer, to the substrate Examples of the method include a method in which the photopolymerizable adhesive layers are laminated so as to be in contact with each other, exposed, and then the support film is peeled off. The latter method is more preferable.

Examples of the light source for the exposure include (super) high pressure mercury lamps and metal halide lamps, and the irradiation amount is preferably 1 to 1000 mJ / cm ² .
More preferably, it is 10 to 500 mJ / cm ² .

The solvent for dissolving the photopolymerizable adhesive layer composition is preferably one that does not swell or dissolve the support film, and examples thereof include methyl ethyl ketone, toluene, tetrahydrofuran, acetone, cyclohexanone and ethyl acetate. To be

The support film is not particularly limited, and examples thereof include polyethylene terephthalate.
Polyester resin; polyolefin resin such as polyethylene and polypropylene; halogen-containing resin such as polyvinyl chloride and polyvinylidene chloride; polyamide resin; polycarbonate resin. A biaxially stretched polyethylene terephthalate film is particularly preferably used.

In order to improve the releasability, the above-mentioned support film is preferably subjected to a peeling treatment. As the peeling treatment, for example, the surface is treated with a known silicone-based or fluorine-based releasing agent. There is a method.

In order to store the adhesive layer sheet in the form of a roll, a protective film is provided on the photopolymerizable adhesive layer or the surface of the support film on which the photopolymerizable adhesive layer is provided. It is preferable that the opposite surface is peeled off.

The method for forming the photopolymerizable resin colored layer on the photopolymerizable adhesive layer in the first step of the present invention is, for example, a coating obtained by dissolving the photopolymerizable resin colored composition in a solvent. Coating the solution with a coater directly on the photopolymerizable adhesive layer, a method of drying, coating the above coating solution on a support film,
After a support film provided with a photopolymerizable resin colored layer obtained by drying (hereinafter referred to as "image forming sheet") was prepared, laminated so as to be in contact with the photopolymerizable adhesive layer, and then,
Although the method of peeling a support film is mentioned, the latter method is more preferable.

By making the above-mentioned photopolymerizable resin colored layer a hue of yellow, magenta, cyan, black or the like, a yellow, magenta, cyan or black image forming sheet is obtained. can get.

The solvent that dissolves the photopolymerizable resin colored layer composition is preferably one that does not swell or dissolve the support film, and examples thereof include methyl ethyl ketone, toluene, tetrahydrofuran, acetone, cyclohexanone, and ethyl acetate.

Examples of the support film include those similar to those used for the adhesive layer sheet.

As the above-mentioned support film, in order to improve the releasability from the colored layer of the photopolymerizable resin, it is preferable to use one which has been subjected to a treatment such as a silicone treatment and a coating of a fluorine-based releasing agent. preferable.

If the thickness of the above-mentioned support film is too thin, it is difficult to uniformly apply the photopolymerizable resin colored layer, and if it is too thick, it takes a long time for exposure for image formation.
The thickness is preferably 0 μm, more preferably 10 to 150 μm.

In the above image forming sheet, a protective layer is preferably provided on the photopolymerizable resin colored layer in order to prevent scratches and stains on the photopolymerizable resin colored layer during handling.

Examples of the protective layer include films made of polyethylene terephthalate; polyester resins; polyolefin resins such as polyethylene and polypropylene.

In the above step, on the photopolymerizable adhesive layer,
As a method for forming an image pattern, for example, a halftone dot negative mask of an original image is prepared, and this is used as a substrate / photopolymerizable adhesive layer / image forming sheet (photopolymerizable resin colored layer / support film). In the order of the above, the support film side of the image forming sheet of the laminated body is exposed and cured.

Then, the support film is peeled off, and the unexposed portion of the photopolymerizable resin colored layer is dissolved and removed with an alkali developing solution to obtain a laminate having a layer structure of substrate / photopolymerizable adhesive layer / image pattern. obtain.

Examples of the light source for exposing and curing the above-mentioned photopolymerizable resin colored layer include (super) high pressure mercury lamps and metal halide lamps.

As the above alkaline developer, for example, 1
A weight% sodium carbonate aqueous solution may be mentioned.

In the second step of the present invention, a photopolymerizable transparent resin layer is laminated on the image pattern side of the laminate, and the entire surface is exposed from the photopolymerizable transparent resin layer side to produce a display board.

The method for forming the photopolymerizable transparent resin layer is, for example, a coating solution obtained by dissolving the photopolymerizable transparent resin layer composition in a solvent and coated directly on the image pattern with a coater. Coating, drying method, coating liquid on the support film,
A transparent resin sheet provided with a photopolymerizable transparent resin layer obtained by drying is prepared, and then the transparent resin sheet is image-patterned.
The photopolymerizable transparent resin layer may be laminated so as to be in contact with the resin, and then the support film may be peeled off and transferred, but the latter method is more preferable.

Examples of the support film include those used in the adhesive layer sheet of the present invention, and a biaxially stretched polyethylene terephthalate film is particularly preferably used.

The thickness of the support film is preferably from 5 to 200 μm, more preferably from 10 to 150 μm, because if the thickness is thin, the uniform coating property of the photopolymerizable transparent resin layer is lowered, and if it is thick, it takes time to expose the entire surface. is there.

The transparent resin sheet is preferably provided with a protective layer on the surface of the photopolymerizable transparent resin layer in order to prevent scratches and stains during handling.

The support film may be directly used as a display panel without being peeled off.

In the production method of the present invention, it is preferable that the transparent resin sheet is formed by providing a photopolymerizable transparent resin layer on the treated surface of a support film having one surface roughened.

The roughening treatment is carried out for the purpose of roughening the surface of the support film so that light is diffusely reflected on the surface of the photopolymerizable transparent resin layer.
Examples of the method include a physical method of spraying sand, a grid or carborundum on the surface of the support film for roughening, and a chemical method of roughening the surface by eroding the surface with a solvent or the like.

The photopolymerizable adhesive layer and the photopolymerizable transparent resin layer used in 2 of the present invention are the same as the photopolymerizable adhesive layer composition and the photopolymerizable transparent resin layer composition used in the present invention, respectively. Can be used.

The photopolymerizable resin colored layer used in 2 of the present invention may be the same as used in the present invention.

As the method for providing the photopolymerizable adhesive layer on the second substrate of the present invention, the same method as used in the present invention can be adopted.

In the second first step of the present invention, the method for forming the image pattern on the photopolymerizable adhesive layer may be, for example, the following method.

First, an original image was prepared by a color separation machine into a halftone dot negative mask which was color-separated into a color tone similar to that of the photopolymerizable resin colored layer used, and this was used as a base / photopolymerizable adhesive layer / image forming sheet. -(G) (photopolymerizable resin colored layer / support film) after being laminated on the support film side of the laminated body,
Exposure is performed from the halftone dot negative mask side to cure the photopolymerizable resin colored layer.

Then, the above-mentioned support film is peeled off, and the unexposed portion of the photopolymerizable resin colored layer is dissolved and removed by an alkali developing solution to obtain a substrate / photopolymerizable adhesive layer / 1-color image pattern.
To obtain a laminated body in which the layers are laminated in this order.

In the second step of the present invention, a photopolymerizable resin colored layer of another color is laminated on the image pattern of the first color obtained in the first step, and the substrate / photopolymerizable adhesive is adhered. Layer / 1
A laminated body is obtained in which the image pattern of the color / the image forming sheet of the other hue (the photopolymerizable resin colored layer of the other hue / the support film) are laminated in this order.

As a method for forming a photopolymerizable resin colored layer of another color tone (second color) on the first color image pattern, for example, a photopolymerizable resin colored composition is obtained by dissolving it in a solvent. The coating solution to be used is directly coated on the image pattern of the first color with a coater and dried, or the coating solution is coated on a support film and dried to laminate a photopolymerizable resin colored layer. After the image-forming sheet is prepared, the photopolymerizable adhesive layer is heated and pressed so that the photopolymerizable resin colored layer is in contact with the photopolymerizable adhesive layer, and then the support film is peeled off to expose the photopolymerizable adhesive layer to light. Examples of the method include a method of transferring the polymerizable resin colored layer, and the latter is preferably used.

Next, a halftone dot negative mask color-separated into the same hue as that of the photopolymerizable coloring layer to be used is laid on the side of the support film in the same manner as the first color so as to match the image pattern of the first color. Exposure is performed from the support film side to cure the photopolymerizable resin colored layer of another hue.

Then, the support film is peeled off, and the unexposed area of the photopolymerizable resin colored layer of another hue is dissolved and removed by an alkali developing solution, and the substrate / photopolymerizable adhesive layer / image layer (1
A laminated body is obtained by laminating the image pattern of the color / the image pattern of the second color in this order.

In the second production method of the present invention, by repeating the second step, the photopolymerizable resin of another color tone (third color and fourth color) is successively and sequentially applied on the second color image pattern. Two or more image patterns may be laminated by laminating colored layers, exposing and curing them, and removing the uncured portions.

To obtain a full color image, for example,
The first, second, third and fourth colors mentioned above are yellow.
A photopolymerizable resin colored layer colored in a system, magenta, cyan or black system may be used.

Examples of the light source for exposing and curing the photopolymerizable resin colored layer include an ultrahigh pressure mercury lamp and a metal halide lamp.

Examples of the alkaline developer include 1
A weight% sodium carbonate aqueous solution may be mentioned.

In the second and third steps of the present invention, after the image type patterns of two or more colors are laminated in the same manner as in the second step of the present invention, a photopolymerizable transparent resin layer is further laminated, The entire surface is exposed and the display panel is manufactured.

[0084]

EXAMPLES Examples of the present invention will be described below. In the following, "parts" means "parts by weight".

(Example 1) (Formation of Photopolymerizable Adhesive Layer on Substrate) As shown in Table 1, the coating liquid of the photopolymerizable adhesive layer composition had a weight average molecular weight of 11
10,000 (polystyrene equivalent by GPC method) polymethyl methacrylate (Asahi Kasei, trade name; Delpet LP-
1), diethoxylated trimethylolpropane triacrylate (manufactured by Toagosei, trade name; M-360), 2, 4,
6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF, trade name; Lucillin TPO) and methyl ethyl ketone are used in predetermined amounts to prepare coating solutions,
An adhesive layer sheet was produced by applying the composition on a polyethylene terephthalate film having a thickness of 38 μm and drying it to provide a photopolymerizable adhesive layer having a thickness of 10 μm.

[0086]

[Table 1]

The above-mentioned adhesive layer sheet was laminated on a polycarbonate plate so that the photopolymerizable adhesive layer was in contact with it, and laminated using a laminator at a temperature of 120 ° C., a pressure of 4 kg / cm ² , and a speed of 1.2 m / min, and 100 mJ / The polyethylene terephthalate film was peeled off by exposure at cm ² .

(Preparation of image-forming sheet) Methyl methacrylate / butyl methacrylate / 2-ethylhexyl methacrylate / methacrylic acid copolymer having a weight average molecular weight of 100,000 (weight ratio 31: 31: 13: 25), Pentaerythritol triacrylate hexamethylene diisocyanate
To (Kyoeisha Yushi Kagaku, trade name; UA306H), yellow pigment (Dainichi Seika, trade name; FPF-5930 ERO), magenta pigment (Dainichi Seika, trade name; FPF)
-6887 magenta), a cyan pigment (manufactured by Dainichiseika, trade name: FPF-CP2 blue), a black pigment (manufactured by Dainichiseika, trade name: FPF-40S black), and methyl ethyl ketone as shown in Table 2. Use a fixed amount of yellow
Of a photo-polymerizable resin coloring composition having a color of a system, magenta, cyan, or black, and coating it on a polyethylene terephthalate film having a thickness of 38 μm, and then drying it to form a photopolymerized film having a thickness of 4 μm. By forming a colored layer of a volatile resin, an image forming sheet having four hues of yellow, magenta, cyan and black was prepared.

[0089]

[Table 2]

(Formation of image pattern) First, a yellow image forming sheet is superposed on a polycarbonate plate provided with a photopolymerizable adhesive layer so that the photopolymerizable adhesive layer and the photopolymerizable resin colored layer are in contact with each other. Temperature 1 using combined laminator
Laminated at 20 ° C., pressure of 4 kg / cm ² , speed of 1.2 m / min, exposed through a halftone dot negative mask color-separated into yellow to expose at 500 mJ / cm ² , peeling off polyethylene terephthalate film, 1 Development was carried out for 1 minute with a weight% sodium carbonate aqueous solution to obtain a yellow image pattern.

Next, a magenta image forming sheet is laminated on the yellow image pattern under the same conditions as in the case of the yellow image pattern, and the magenta image mesh sheet is aligned so as to match the yellow image pattern. An image pattern in which a dot-like negative mask is arranged, exposed in the same manner, and developed to be magenta color-separated.
I got it.

Similar operations were repeated for cyan and black systems to form a full-color image layer on the polycarbonate plate through the photopolymerizable adhesive layer.

(Preparation of Photopolymerizable Transparent Resin Sheet) Polymethylmethacrylate (Asahi Kasei, trade name; Delpet LP-1) having a weight average molecular weight of 110,000 (in terms of polystyrene by GPC method), trimethylolpropane Triacrylate (manufactured by Shin-Nakamura Chemical, trade name; A-TMPT), 2, 4,
6-Trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF, trade name; Lucillin TPO) and methyl ethyl ketone were used in the respective predetermined amounts shown in Table 3 to prepare a coating solution, which was coated on a polyethylene terephthalate film having a thickness of 38 μm and dried. Thus, a transparent resin sheet provided with a photopolymerizable transparent resin layer having a thickness of 15 μm was manufactured.

(Production of Display Board) An image pattern of four colors provided on the polycarbonate plate through a photopolymerizable adhesive layer.
The transparent resin sheet is superposed so that the image layer on which the resin is laminated and the photopolymerizable transparent resin layer are in contact with each other, and the temperature is 120 ° C., the pressure is 4 kg / cm ² , and the speed is 1.2 using a laminator.
Laminated at m / min. This was exposed at 1000 mJ / cm ² from the photopolymerizable transparent resin layer side, and then the polyethylene terephthalate film was peeled off to manufacture a display board.

Example 2 An image forming sheet having a brown hue was prepared using the photopolymerizable resin coloring composition shown in Table 2, and the photopolymerizable transparent resin layer composition shown in Table 3 was prepared. A display board was manufactured in the same manner as in Example 1 except that a transparent resin sheet was prepared using.

Examples 3 to 6 Tables 3 to 6 show diethoxylated trimethylolpropane triacrylate and 2,4,6-trimethylbenzoyldiphenylphosphine oxide as photopolymerizable transparent resin layer compositions. A display board was manufactured in the same manner as in Example 2 except that the predetermined amount was changed.

[0097]

[Table 3]

(Examples 7 to 10) In Example 7, the diethoxylated trimethylolpropane triacrylate in the photopolymerizable transparent resin layer composition was replaced with trimethylolpropane triacrylate in a predetermined amount shown in Table 3, and In 8, polyethylene glycol # 200 diacrylate,
In Example 9, polyethylene glycol # 400 diacrylate and in Example 10 tetramethylolmethane tetraacrylate were used in the predetermined amounts shown in Table 3, 2, 4,
A display panel was manufactured in the same manner as in Example 2 except that 6-trimethylbenzoyldiphenylphosphine oxide was changed to the predetermined amount shown in Table 3.

(Examples 11 to 13) In Examples 11 and 12, the diethoxylated trimethylolpropane triacrylate of the photopolymerizable adhesive layer composition was set to the predetermined amount shown in Table 2,
In Example 13, a display board was produced in the same manner as in Example 2 except that dimethylolpropane triacrylate was used instead of diethoxylated trimethylolpropane triacrylate and the predetermined amounts shown in Table 1 were used.

Comparative Examples 1 to 4 Diethoxylated trimethylolpropane triacrylate and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in the photopolymerizable transparent resin layer composition were changed to the predetermined amounts shown in Table 4. A display panel was manufactured in the same manner as in Example 2.

(Comparative Examples 5 to 8) The diethoxylated trimethylolpropane triacrylate of the photopolymerizable transparent resin layer composition was set to the predetermined amount shown in Table 4, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide was used as Comparative Example 5 In benzyl dimethyl ketal (manufactured by Ciba-Geigy, trade name; Irgacure-651), in Comparative Example 6, Mihira-ketone (manufactured by Nippon Soda, trade name; Nisso Cure-MAB).
P), and in Comparative Example 7, 2,4-diethylthioxanthone (manufactured by Nippon Kayaku, trade name; Kayacure-DETX) and 4-
In Comparative Example 8, a mixture of ethyl dimethyl benzoate (manufactured by Nippon Kayaku, trade name; Kayacure-EPA) was replaced with a mixture of benzophenone (manufactured by Nippon Kayaku, trade name; Kayacure-BP) and ethyl 4-dimethylbenzoate. A display panel was manufactured in the same manner as in Example 2 except that the predetermined amount shown in Table 4 was used.

[0102]

[Table 4]

Comparative Examples 9 to 11 In Comparative Example 9, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and diethoxylated trimethylolpropane triacrylate of the photopolymerizable adhesive layer composition were used in the predetermined amounts shown in Table 5. In Comparative Example 10, 2,4,6-trimethylbenzoyldiphenylphosphine oxide was replaced with benzyl dimethyl ketal, and benzyl dimethyl ketal and diethoxylated trimethylolpropane triacrylate were adjusted to the predetermined amounts shown in Table 5, In 11, 2,4,6-trimethylbenzoyldiphenylphosphine oxide was added to 2,4-
Diethoxylated trimethylolpropane triacrylate and the above mixture in place of a mixture of diethyl thioxanthone (Nippon Kayaku, trade name; Kayacure-DETX) and ethyl 4-dimethylbenzoate (Nippon Kayaku, trade name; Kayacure-EPA) A display panel was manufactured in the same manner as in Example 2 except that the predetermined amount shown in Table 5 was used.

[0104]

[Table 5]

The display panels obtained in Examples 1 to 13 and Comparative Examples 1 to 11 were subjected to an adhesion test and a light resistance test, and the results are shown in Tables 6 and 7.

[0106]

[Table 6]

[0107]

[Table 7]

The transparent resin sheets obtained in Examples 1 to 10
Photopolymerization test using the adhesive layer sheets obtained in Examples 11 to 13, the transparent resin sheets obtained in Comparative Examples 1 to 8 and the transparent resin sheets obtained in Comparative Examples 9 to 11. The results were shown in Tables 6 and 7.

(Adhesion test) A 100 mm square 1 mm square cut was made with an NT cutter on the photopolymerizable transparent resin layer side of the obtained display board, and a knit-polyester adhesive tape was formed.
Peeling (Nitto Denko; No. 31) was used for peeling, and the number of crosses that were not peeled off for 100 pieces was evaluated.

(Light resistance test) The yellowing degree (Δ) of a portion of the obtained display panel where no image was provided after 500 hours in a discoloration tester for paint (manufactured by Suga Test Instruments; FM-1)
E) was measured by a color computer (manufactured by Suga Test Instruments; SM-3 ″) in accordance with JIS K-7103. As a blank, an organic polymer and an unsaturated compound photopolymerizable with an organic polymer were used on the same polycarbonate plate. The photopolymerizable adhesive layer and the photopolymerizable transparent resin layer were formed in the same manner as in Example 1 and used.

For the evaluation, a visual evaluation was made according to the following criteria together with the yellowing degree (ΔE). ○: No yellowing was observed ×: Yellowing was observed × ×: Significant yellowing was observed.

(Photopolymerization test) The adhesive layer sheet or the transparent resin sheet was directly laminated on the polycarbonate plate, and the temperature was 120 ° C. and the pressure was 4 kg / cm ² , using a laminator.
Laminated at a speed of 1.2 m / min and 10 mJ / c
The cumulative exposure amount was measured by exposing m ^{2 at a} time and eliminating tackiness on the surface.

[0113]

The photopolymerizable adhesive layer composition and the photopolymerizable transparent resin layer composition used in the present invention contain the acylphosphine oxide-based photopolymerization initiator as described above, and thus the substrate and the image, It is possible to manufacture a display panel having excellent adhesion between images and less yellowing in the non-image area.

Claims (2)

[Claims] 1. A photopolymerizable resin coloring containing at least one colorant selected from the group consisting of black, yellow, magenta and cyan on the photopolymerizable adhesive layer provided on a substrate. The first step of forming an image pattern by stacking the layers, exposing the photopolymerizable resin colored layer through a negative mask, and curing it, and removing the uncured portion; A method for producing a display board comprising a second step of laminating a polymerizable transparent resin layer and exposing the entire surface from the photopolymerizable transparent resin layer side, wherein the photopolymerizable adhesive layer is an acylphosphine oxide photopolymerization initiator. And a photopolymerizable adhesive layer composition containing a photopolymerizable transparent resin layer, wherein the photopolymerizable transparent resin layer comprises a photopolymerizable transparent resin layer composition containing an acylphosphine oxide photopolymerization initiator. . 2. A photopolymerizable adhesive layer provided on a substrate,
A photopolymerizable resin colored layer having a hue of at least one of black, yellow, magenta and cyan
Layering, exposing the photopolymerizable resin colored layer through a negative mask, curing, and removing the uncured portion to form an image pattern of the first color. First step, on the image pattern. , A photopolymerizable resin colored layer having another color tone is sequentially laminated, and each time when laminated, the photopolymerizable resin colored layer is exposed and cured through a negative mask, and the uncured portion is removed to obtain at least two colors. Second step of laminating the above image patterns to form an image layer, and laminating a photopolymerizable transparent resin layer on the image layer, and exposing the entire surface from the photopolymerizable transparent resin layer side A method for manufacturing a display board comprising steps, wherein the photopolymerizable adhesive layer comprises a photopolymerizable adhesive layer composition containing an acylphosphine oxide-based photopolymerization initiator, and the photopolymerizable transparent resin layer comprises an acylphosphine oxide. -Based photopolymerization Display panel manufacturing method characterized by comprising the transparent resin layer composition.