JPH0747757A - Image forming sheet - Google Patents

Abstract

PURPOSE:To obtain a sheet which has excellent adhesive properties between layers and in which an image layer having no discoloring and no fading can be formed by sequentially providing a photopolymerizably colored layer and a photopolymerizable adhesive layer containing acyl-phosphine oxide photopolymerization initiator in this order on one side of a transparent support. CONSTITUTION:An image forming sheet is used to manufacture a display board on which a colored image layer is formed on a board. The display board is used for an instrument board, etc., of various units. In this case, the sheet is composed by sequentially providing a photopolymerizably colored layer and a photopolymerizable adhesive layer containing acyl-phosphine oxide photopolymerization initiator in this order on one side of a transparent support. Incidentally, the support may have chemical and thermal stabilities and excellent transparency such as a film made, for example, of polyester resin, etc. The colored layer is formed, for example, of linear polymer, photopolymerizably unsaturated compound, etc. Further, the adhesive layer is formed, for example, of organic polymer, photopolymerizably unsaturated compound, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming sheet used for manufacturing a display panel having a colored image layer formed on a substrate. It can be used as a dial for a personal computer.

[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. A printing method has been used, especially a screen printing method and an offset printing method have been used. However, in recent years, as products have become more sophisticated and diversified, studies are being made to improve the decorativeness and visibility of the colored image, and multicoloring is one of them.

However, in the screen printing method, ink is required for the number of colors in order to obtain multiple colors, and the printing process is complicated. Further, it is necessary to adjust the viscosity of the ink and dry-cure it. It takes 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.

In the offset printing method, the color density required for the display board cannot be obtained because the coating film of ink cannot be thickened.

Instead of the above printing method, for example, an image-forming sheet having a photopolymerizable colored layer is used to form an image by exposure and development, and then transferred to the image-receiving layer by applying heat and pressure. A method for obtaining an image is disclosed in JP-A-47-41830 and JP-A-48-93337.

Further, there has been proposed a method for producing a multicolor display board by using an image forming sheet having a photopolymerizable colored layer. For example, a transparent photopolymerizable adhesive layer is provided on a substrate. , A method of producing a display board by sequentially laminating photopolymerizable colored layers containing pigments of respective colors thereon, imagewise exposing and developing using a negative mask for each lamination, and laminating an image layer on an adhesive layer. Is disclosed in Japanese Patent Laid-Open No. 210210/1990.

However, the above method of manufacturing a display board has a drawback that the photopolymerizable adhesive layer is yellowed because it is exposed every time an image is formed and the display board is discolored.

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 transparent. Of laminating various photopolymerizable resin layers to produce
It is disclosed in Japanese Patent No. 210220.

However, in the above method of manufacturing the display board, the developed image is transferred to the substrate, so that the adhesiveness between the substrate and the image is not sufficient and peeling and floating easily occur. The images exposed and developed by a color separation negative mask are laminated for multi-coloring, but the adhesion between the images is not sufficient and peeling off easily occurs. In addition, there are drawbacks such as discoloration and fading of images due to sunlight and fluorescent lamps in use, and discoloration and fading of images due to exposure to ultraviolet rays during the manufacturing process.

On the other hand, a method for improving the adhesiveness of an image by providing an adhesive layer on the photopolymerizable colored layer of the image forming sheet is disclosed in JP-A-1-169447.

However, in the above method, since the adhesive layer is made of a thermoplastic resin, it has a drawback that it cannot withstand the high temperature in summer when used as a vehicle display panel.

In general, the negative type photosensitive adhesive composition has a drawback that the photopolymerization initiator is highly colored and the non-image area shows a yellow color when it is used as a display board. (JP-A-3-22808)

As a photopolymerization initiator with little coloring and high sensitivity, for example, Japanese Patent Publication No. 63-40799 discloses an acylphosphine oxide compound such as benzoylphenylphosphine oxide and a method of using the same. There is no specific disclosure of its applicability to adhesive compositions.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an image layer having excellent adhesion between a support and an image layer or between image layers and having no discoloration or fading. It is an object of the present invention to provide an image forming sheet capable of forming an image.

[0016]

The image-forming sheet of the present invention comprises a photopolymerizable colored layer and a photopolymerizable adhesive layer containing an acylphosphine oxide-based photopolymerization initiator on one surface of a transparent support. Are stacked in this order.

The transparent support may be chemically and thermally stable and has excellent transparency, and examples thereof include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyethylene, polypropylene and the like. Polyolefin resins, halogen-containing resins such as polyvinyl chloride and polyvinylidene chloride, polyamide resins, polycarbonate
Examples of the film include a binder resin.

Particularly, a biaxially stretched polyethylene terephthalate film is preferably used.

The above-mentioned photopolymerizable colored layer comprises, for example, (a) linear polymer, (b) photopolymerizable unsaturated compound, (c) photopolymerization initiator, (d) colorant and (e) solvent. Is formed from the photopolymerizable coloring composition.

Examples of the above linear polymer (a) include:
A copolymer of α, β-unsaturated ethylenic monomer containing a carboxyl group and α, β-unsaturated ethylenic monomer not containing a carboxyl group is used, and α, β containing a carboxyl group -As the unsaturated ethylenic monomer,
Examples thereof include unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid. These may be used alone or in combination of two or more kinds. May be done.

Α, β-containing no carboxyl group
Unsaturated ethylenic monomer contains the above carboxyl group
Copolymerizable with α, β-unsaturated ethylene monomer
And styrene, o-methylstyrene
Amine, m-methylstyrene, p-methylstyrene, α-me
Cylstyrene, p-ethylstyrene, 2,4-dimethyl
Styrene, pn-hexyl styrene, pn-octyl
Rustyrene, p-methoxystyrene, p-phenylstyrene
Styrene such as len and 3,4-dimethylchlorostyrene
Kinds; α-vinylnaphthalene, ethylene, propylene, bromine
Chilen or C_Five~ C ₃₀Α-olefins such as vinyl chloride
Vinyl halides such as vinyl chloride and vinyl bromide; vinyl acetate, vinyl acetate
Vinyl esters such as vinyl ropionate and vinyl butyrate;
Methyl (meth) acrylate, Propyl (meth) acrylate
N-butyl (meth) acrylate, (meth) acrylic
N-octyl acid, isobutyl (meth) acrylate, (meth
) Lauryl acrylate, 2-Ethyl (meth) acrylate
Luhexyl, 2-chloroethyl (meth) acrylate, α
-Methyl chloro (meth) acrylate, (meth) acrylic
Acid phenyl, dimethylaminoethyl (meth) acrylate
(Meth) acrylic acid esters such as vinyl methyl ether
Vinyl ethers such as ter and vinyl ethyl ether;
Vinyl keto such as nyl methyl ketone and vinyl ethyl ketone
N-vinylpyrrole, N-vinylindole, etc.
N-vinyl compound; (meth) acrylonitrile;
(A) Acrylic acid amides and the like. These are just
May be used alone, or may be used in combination of two or more
Yes.

When the content of the α, β-unsaturated ethylenic monomer component containing a carboxyl group in the copolymer (a) is small, the developability for an alkaline aqueous solution is low, and when it is high, the coating solvent is used. The solubility is decreased, the thickness accuracy of the photopolymerizable colored layer is decreased, and the resolution of the obtained image is decreased. Therefore, the content is preferably 10 to 40% by weight, more preferably 15 to 35% by weight.

When the weight average molecular weight of the linear polymer (a) is small, wrinkles are easily formed in the photopolymerizable colored layer during storage, and when it is large, the developability in an alkaline solution is deteriorated. Is preferable, and more preferably 50,000 to 300,000.

The photopolymerizable unsaturated compound (b) may be any one as long as it has a property of initiating polymerization with actinic rays.
For example, a compound represented by the general formula (1) or a photopolymerizable monomer that is liquid at room temperature other than the above can be used.

[0025]

[Chemical 1]

In the general formula (1), R ¹ is a divalent linear, branched, alicyclic or aromatic hydrocarbon group such as ethylene group, propylene group or neopentyl group. X is a divalent linear, branched, alicyclic or aromatic hydrocarbon group, for example, a hexamethylene group,
Examples thereof include a tolylene group and an isophorone group. m is 5
An integer of 100, n is an integer of 1 to 15, and A is selected from general formula (2), general formula (3) and general formula (4).

[0027]

[Chemical 2]

[0028]

[Chemical 3]

[0029]

[Chemical 4]

General formula (2), general formula (3) and general formula
In (4), R², R³And R ^FourIs hydrogen or
Represents a chill group.

Examples of the photopolymerizable monomer that is liquid at room temperature other than the above include, for example, triethylene glycol (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol dihydrate. (Meth) acrylate
Polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, nonapropylene glycol di (meth) acrylate, polypropylene Glycolic di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylation 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,
Examples thereof include polyfunctional monomers such as 1,6-bis (3-acryloxy-2-hydroxypropyl) hexyl ether.

Examples of the photopolymerizable unsaturated compound other than the above are, for example, monofunctional monomers such as methyl (meth) acrylate and benzyl (meth) acrylate, and acrylate oligomers of urethane and polyester. Is mentioned.

When the amount of the photopolymerizable unsaturated compound (B) added is small, the surface hardness of the photopolymerizable colored layer after exposure is insufficient and the image is easily deformed, and when the amount is large, the film is stored in a roll-rolled state. Since cold flow occurs and the photopolymerizable colored layer is deformed while being placed, it is preferably 10 to 250 parts by weight, more preferably 30 to 200 parts by weight, relative to 100 parts by weight of the linear polymer (a). is there.

The photopolymerization initiator (C) may be any one as long as it has a property of activating the photopolymerizable unsaturated compound (B) by actinic rays such as ultraviolet rays and visible rays to initiate the polymerization. Sulfites such as sodium methyl dithiocarbamate sulfite, tetramethyl thiuram monosulfite, diphenyl monosulfite, dibenzothiazoyl monosulfite, dibenzothiazoyl disulfite; thioxanthone, 2-ethylthioxanthone, 2-Chlorothioxanthone Derivatives of thioxanthone such as 2,4 diethylthioxanthone; hydrazones, azoisobutyronitrile, diazo compounds such as benzenediazonium, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropylate ether , Benzov Non, dimethylamino benzophenone, Michler's - ketone, benzyl anthraquinone, t
-Butylanthraquinone, 2-methylanthraquinone 2
-Ethylanthraquinone, 2-aminoanthraquinone,
2-chloroanthraquinone, benzyl dimethyl ketah
Aromatic carbonyl compounds such as methyl and methylphenylglyoxylate; 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone; α-hydroxy-α, α'-dimethylacetophenone; Acetophenone derivatives such as 2-diethoxyacetophenone and 2,2-dimethoxyacetophenone; methyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate,
Dialkylaminobenzoic acid esters such as butyl p-dimethylaminobenzoate and isopropyl p-diethylaminobenzoate; peroxides such as benzoylperoxide, di-t-butylperoxide, dicumylperoxide, cumene hydroperoxide; 9- Acridine derivatives such as phenylacridine, 9-p-methoxyphenylacridine, 9-acetylaminoacridine and benzacridine; 9,10-dimethylbenzophenazine, 9
-Methylbenzphenazine, phenazine derivatives such as 10-methoxybenzphenazine; quinosaline derivatives such as 6,4 ', 4 "-trimethoxy-2,3-diphenylquinosaline; 2,4,5-triphenylimidazoyl 2. Compounds, halogenated ketones, 2,4,6-trimethylbenzoylphenylphosphine oxide; acylated phosphorus compounds such as acyl phosphate; 2-nitrofluorene, 2,
4,6-triphenylpyrylium boron tetrafluoride salt, 2,
4,6-tris (trichloromethyl) -1,3,5-triazine, 3,3′-carbonylbiscoumarin, thiomihira-ketone and the like can be mentioned.

If the amount of the photopolymerization initiator (c) added is too small, the curing will be insufficient, and if it is too large, the cured resin will be colored or brittle. The amount is preferably 0.1 to 10 parts by weight.

As the colorant (d), known pigments and dyes can be used. For example, as a yellow pigment,
Hansa yellow, benzidine yellow, cadmium yellow,
Examples include yellow lead G, zinc chromate, lemon yellow, strocian yellow, isoindolino yellow, indian yellow, and the like, and magenta pigments include rhodamine B lake, cadmium red, red iron oxide, and red iron oxide. Examples include chrome bar million, pyrazolone red, litho red, red lead, quinacridone red, and watching red.The cyan pigments include ultramarine blue, prussian blue, cobalt blue, cerulean blue, and mangany blue. , Phthalocyanine nimble, etc.,
Examples of black pigments include carbon black, titanium black, iron black and the like.

When the addition amount of the above-mentioned colorant (d) is small, coloring becomes insufficient, and when the addition amount is large, the photopolymerizable colored layer becomes brittle. 1 to 300 parts by weight is preferable.

Examples of the solvent (e) include polar solvents such as methyl ethyl ketone, ethyl acetate and methanol.

The composition of the photopolymerizable colored layer used in the present invention is as described above, but if necessary, dioctyl phthalate, triethylene glycol diacetate, P-
Plasticizers such as toluene sulfonamide, N-ethyltoluene sulfonamide, hydroquinone, P-methoxy-
A thermal polymerization inhibitor such as phenol, a heat stabilizer, an ultraviolet absorber, an antioxidant, methyl ethyl ketone, toluene and the like may be added.

The thickness of the photopolymerizable colored layer forming the image-forming sheet is not particularly limited, but if it becomes thick, it will easily peel off from the support, and if it becomes thin, it will be difficult to handle.
0.5 to 20 μm is preferable.

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

As the above-mentioned photopolymerizable adhesive composition, for example, a composition comprising an organic polymer, a photopolymerizable unsaturated compound, a solvent and an acylphosphine oxide photopolymerization initiator is used.

A thermoplastic resin having a softening point of 150 ° C. or lower is preferably used as the organic polymer, and examples of the thermoplastic resin include polyolefins, copolymers of ethylene and α- or β-unsaturated carboxylic acids, Resin cross-linked with a metal ion of a copolymer of ethylene and α, β-unsaturated carboxylic acid, a polymer or copolymer of vinylidene chloride, polyacrylonitrile, poly-N-vinylcarbazole, polyvinyl alcohol, Poly-N-vinylpyrrolidone, polyamide, polyurethane, ethylene / vinyl acetate copolymer, styrene / isoprene or butadiene copolymer, acrylonitrile / butadiene copolymer, butyl rubber, polyacrylic ester polymer or copolymer, etc. Is mentioned.

Examples of the organic polymer other than the above include the linear polymer (a) used in the photopolymerizable colored layer.

When the weight average degree of polymerization of the organic polymer is small, the photopolymerizable adhesive layer is applied, dried, and wound into a roll to be easily wrinkled during storage, and when the weight average degree of polymerization is large, coating is performed. Since the viscosity at that time becomes too high and uneven coating is possible, the viscosity is preferably 10,000 to 1,000,000, more preferably 50,000 to 1,000,000.

Examples of the photopolymerizable unsaturated compound include the photopolymerizable unsaturated compound (b) used in the photopolymerizable colored layer.

If the amount of the above-mentioned photopolymerizable unsaturated compound added is small, the surface hardness of the photopolymerizable colored layer after exposure will be insufficient, and the image will be easily deformed. If the amount is large, the film will be stored in a rolled state. Since cold flow occurs during placement and the photopolymerizable adhesive layer is deformed, it is preferably 10 to 250 parts by weight, more preferably 30 to 100 parts by weight, relative to 100 parts by weight of the organic polymer.
It is 200 parts by weight.

The acylphosphine oxide-based photopolymerization initiator has a property of activating the photopolymerizable unsaturated compound by actinic rays such as ultraviolet rays and visible rays to initiate polymerization, and for example, 2, 4,6-trimethylbenzoyldiphenylphosphine oxide, pivaloyldiphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, terephthaloyl-bis-diphenylphosphine oxide, 1-methyl-cyclohexylcarbonyldiphenylphosphine oxide, 4
-Methylbenzoyl-phenylphosphinic acid methyl ester, 2,4,6-trimethylbenzoyl-phosphinic acid diethyl ester and the like can be mentioned. These may be used alone or in combination of two or more.

If necessary, the photopolymerizable initiator (C) may be added to increase the polymerization rate,
To reduce polymerization inhibition by oxygen, triethano-
Auxiliaries such as ruamine and dialkylaminobenzoic acid ester may be added.

If the amount of the above-mentioned acylphosphine oxide photopolymerization initiator added is too small, the curing will be insufficient, and if it is too large, the cured resin will be colored or brittle. 0.1-1
0 parts by weight is preferred.

The composition of the photopolymerizable adhesive layer used in the present invention is as described above, but if necessary, alicyclic saturated hydrocarbon resin, rosin resin, petroleum resin, coumarone-indene resin, terpene resin. Adhesives such as dioctyl phthalate, triethylene glycol diacetate, plasticizers such as P-toluenesulfonamide, N-ethyltoluenesulfonamide, etc., thermal polymerization of hydroquinone, P-methoxyphenol, etc. Inhibitor, heat stabilizer, UV absorber,
Antioxidants, methyl ethyl ketone, toluene and the like may be added.

When the thickness of the photopolymerizable adhesive layer is thin, it is difficult to handle and the adhesive strength becomes insufficient, and when it is thick, when the image forming sheets are laminated to form a multi-color image layer, a deviation occurs in each color image layer. Since it occurs, the thickness is preferably 0.1 to 20 μm.

In the image forming sheet of the present invention, for example, a photopolymerizable colored layer composition is coated on a transparent support with a coater and dried to form a photopolymerizable colored layer. The photopolymerizable adhesive composition is obtained by coating the photopolymerizable adhesive composition on the functional colored layer with a coater and drying the composition to form the photopolymerizable adhesive layer.

As another method for obtaining the above-mentioned image forming sheet, for example, a photopolymerizable adhesive layer composition is coated on a temporary support with a coater and dried to form a photopolymerizable adhesive layer. The photopolymerizable coloring composition is coated on the above-described laminated body and the transparent support with a coater and dried to separately form a laminated body having a photopolymerizable colored layer formed thereon, and then two laminated bodies. A method may be mentioned in which the photopolymerizable adhesive layer and the photopolymerizable colored layer are superposed such that they are in contact with each other and heated and pressed to transfer the photopolymerizable adhesive layer onto the photopolymerizable colored layer.

The temporary support may be a film which is chemically and thermally stable and flexible, and examples thereof include polyethylene terephthalate; polyolefin resins such as polyethylene and polypropylene; polyvinyl chloride and polychlorine. Examples of the film include a halogen-containing resin such as vinylidene; a polyamide resin; a polycarbonate resin.

The surface of the temporary support on which the photopolymerizable adhesive layer is to be provided may be subjected to a peeling treatment. If the thickness is thin, it becomes difficult to handle, and if it is thick, the followability during transfer is deteriorated. 200 μm is preferable.

When the method of coating the photopolymerizable adhesive composition on the photopolymerizable colored layer is used in the production of the image forming sheet, the solvent of the photopolymerizable adhesive composition is the photopolymerizable colored layer. It is preferable to use one that does not dissolve or swell.

Examples of the solvent used for the photopolymerizable adhesive composition include non-polar solvents such as hexane, heptane, octane, petroleum ether, toluene and xylene.

The temperature for drying the solvent is preferably 30 to 120 ° C., because if the temperature is low, it takes a long time to dry and the residual amount of the solvent is large, and if the temperature is high, color fog occurs.

When used in a method of transferring a photopolymerizable adhesive layer onto a photopolymerizable colored layer when producing an image-forming sheet, the laminator temperature is the softening temperature of the photopolymerizable adhesive layer. Although it is appropriately determined depending on the conditions, it is usually preferably carried out at 50 to 130 ° C.

When the image-forming sheet of the present invention is laminated on a substrate, imagewise exposed and developed, the transparent support is peeled off to obtain a laminate having a layer structure of substrate / photopolymerizable adhesive layer / image layer. Used for.

A photopolymerizable adhesive layer of another image forming sheet was laminated on the image layer so as to be in contact with the image layer, imagewise exposed, developed and multilayered by peeling the support. An image layer can be obtained.

Yellow, magenta, cyan, black,
A negative mask in which one original image is color-separated into each color each time it is laminated on the substrate using the image forming sheet of No. 1, and further converted into a halftone dot image, and the shade of the color is converted into the size of the halftone dot. Image exposure from the side of the support through the support, peeling off the support, developing and multilayering to form substrate / photopolymerizable adhesive layer / yellow-image layer / photopolymerizable adhesive layer / magenta image layer / photopolymerizable A full color image having a layer structure of adhesive layer / cyan image layer / photopolymerizable adhesive layer / black image layer can be obtained.

The above-mentioned substrate is not particularly limited in terms of material, and a substrate having appropriate flexibility and being hard to be deformed by heat is selected. For example, polycarbonate resin, polyester resin such as polyethylene terephthalate, polyolefin resin such as polyethylene and polypropylene, halogen-containing resin such as polyvinyl chloride and polyvinylidene chloride, polyamide resin and poly (meth) acrylic acid ester. Examples thereof include plate-shaped bodies made of resin and the like, glass plates, ceramics plates, metal plates and the like.

The above-mentioned substrate may be subjected to a primer treatment or an adhesive for the purpose of improving the adhesiveness to the photopolymerizable adhesive layer.

Lamination on the base or image layer of the image forming sheet,
For example, by means of a laminar roll, the temperature of the laminar roll depends on the substrate used and the imaging sheet.
The temperature is appropriately determined according to the softening temperature of the photopolymerizable adhesive layer or the photopolymerizable colored layer, but usually 50 to 130 ° C. is preferable.

The light source for image exposure is not particularly limited, and, for example, an ultrahigh pressure mercury lamp, a metal halide lamp or the like is preferably used.

The developer used in the development is
For example, an aqueous solution of sodium carbonate having a concentration of 0.5 to 5% by weight can be used.

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

Example 1 As shown in Table 1, as linear polymers, methyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate and methacrylic acid were 31 parts, 31 parts, 13 parts and 25 parts, respectively. Which has an average molecular weight of 100,000, and pentaerythritol triacryleate as a photopolymerizable unsaturated compound.
2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF, trade name; Lucirin TPO) is used as a photopolymerization initiator, and a black pigment (produced by Dainichi Seika, trade name; FPF-40S Black) ), As a yellow pigment (manufactured by Dainichiseika, trade name; FPF-2
7 yellow), as a magenta pigment (manufactured by Dainichiseika, trade name; FPF-6887 magenta), and as a cyan pigment (made by Dainichiseika, trade name; FPF-CP2 Bull), as shown in Table 1. Production of black photopolymerizable colored layer composition coating liquid, yellow photopolymerizable colored layer composition coating liquid, magenta photopolymerizable colored layer composition coating liquid, cyan photopolymerizable coloring composition coating liquid did.

[0070]

[Table 1]

25 μm thick polyethylene terephthalate
A laminate comprising a polyethylene terephthalate film in which the black photopolymerizable colored layer composition coating liquid described above is applied onto a printed film and dried at 90 ° C. for 2 minutes to provide a black photopolymerizable colored layer of 3 μm. Got

Similarly, a yellow photopolymerizable coloring composition coating liquid, a magenta photopolymerizable coloring composition coating liquid, and a cyan photopolymerizable coloring composition coating liquid were used, and yellow, magenta, and cyan were used, respectively. A laminate comprising a polyethylene terephthalate film provided with the photopolymerizable colored layer of was obtained.

Then, as shown in Table 2, polymethylmethacrylate having a weight average molecular weight of 110,000 as measured by GPC was used.
(Asahi Kasei, trade name; Delpet LP-1), trimethylol propane triacryl as a multifunctional monomer
(Shin Nakamura Chemical Co., Ltd., trade name; A-TMPT), a photopolymerization adhesive composition using 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF, trade name; Lucilin TPO) as a photopolymerization initiator. A coating solution was prepared.

[0074]

[Table 2]

The above-mentioned photopolymerizable adhesive composition coating liquid is applied to each of the laminates so as to have a layer structure of polyethylene terephthalate film / photopolymerizable coloring layer / photopolymerizable adhesive layer /.
After drying at 115 ° C. for 2 minutes, a black, yellow, magenta and cyan image forming sheet having a photopolymerizable adhesion of 5 μm was obtained.

The yellow image forming sheet was laminated on a polycarbonate substrate so that the photopolymerizable adhesive layer was in contact therewith, and the temperature was 120 ° C. and the pressure was 5 k using a laminator roll.
Lamination was carried out at a line speed of 1.2 m / min of g / cm ² to obtain a laminate having a layer structure of substrate / photopolymerizable adhesive layer / photopolymerizable colored layer / polyethylene terephthalate film.

On the polyethylene terephthalate film side of the obtained laminate, a negative mask in which the original image was color-separated into a yellow color by a color-separating machine and the color shade was converted into the size of halftone dots was overlaid, and 400 mJ with an ultra-high pressure mercury lamp. It was exposed to ultraviolet rays of / cm ² .

Then, the above-mentioned polyethylene terephthalate film was peeled off and subjected to a spud development treatment at 25 ° C. for 45 seconds using a 1 wt% sodium carbonate aqueous solution at a pressure of ² Kg / cm ² to dissolve and remove the unexposed portion, and / Photopolymerizable adhesive layer /
A layered product consisting of a yellow image layer was obtained.

Then, the photopolymerizable adhesive layer of the magenta image forming sheet and the yellow image layer were superposed so that they were in contact with each other, and the temperature was 120 ° C. and the pressure was 5 k using a laminator.
Laminate at g / cm ² , line speed 1.2 m / min,
A laminate having a layer structure of substrate / photopolymerizable adhesive layer / yellow image layer / photopolymerizable adhesive layer / photopolymerizable colored layer of magenta / polyethylene terephthalate film was obtained.

From the polyethylene terephthalate film side of the obtained laminate, a negative mask, which was color-separated into magenta and the color density was converted into the size of halftone dots, was overlaid so as to match with the yellow image, and was superposed by an ultra-high pressure mercury lamp. It was exposed to ultraviolet light of 400 mJ / cm ² .

Then, the polyethylene terephthalate film was peeled off at 25 ° C. in the same manner as in the yellow image formation.
2 kg / cm ² using a 1 wt% sodium carbonate aqueous solution
Under pressure for 45 seconds for spray development, and the unexposed portion was dissolved and removed to obtain a laminate having a layer structure of substrate / photopolymerizable adhesive layer / yellow image layer / photopolymerizable adhesive layer / magenta image layer. .

A cyan / black image layer was formed in the same manner as in the case of forming a magenta image layer using the cyan / black image forming sheet, and the substrate / photopolymerizable adhesive layer / yellow image layer / photopolymerization layer was formed. To obtain a laminated body having a layer structure of a photosensitive adhesive layer / magenta image layer / photopolymerizable adhesive layer / cyan image layer / photopolymerizable adhesive layer / black image layer, and then 200 mJ / cm ² from the black image layer side with an ultrahigh pressure mercury lamp. A full-color display panel was manufactured by fully exposing it to the ultraviolet rays of.

(Example 2) Instead of the four-color image forming sheets of yellow, magenta, cyan and black of Example 1, a brown image forming sheet shown in Table 3 and a color separation into brown were formed. A display panel was manufactured in the same manner as in Example 1 except that the negative mask thus prepared was used and the image layer was one layer.

[0084]

[Table 3]

(Embodiment 3) A thickness of 25 is preliminarily peeled to form the photopolymerizable adhesive layer of the image forming sheet.
The photopolymerizable adhesive composition coating liquid shown in Table 2 was applied to the treated surface of a micron polyethylene terephthalate film, dried to form a photopolymerizable adhesive layer, and then obtained in the same manner as in Example 1. The photopolymerizable colored layer of the polyethylene terephthalate film provided with the photopolymerizable colored layer and the photopolymerizable adhesive layer are superposed so as to be in contact with each other, and the temperature is 120 ° C. and the pressure is 5 kg using a laminator. / Cm ² ,
Laminating at a line speed of 1.2 m / min, peeling off the polyethylene terephthalate film on the photopolymerizable adhesive layer side,
An image forming sheet was manufactured.

A display board was manufactured in the same manner as in Example 1 except that the above image forming sheet was used instead of the image forming sheet of Example 1.

Example 4 A display board was manufactured in the same manner as in Example 3 using the brown image forming sheet obtained in the same manner as in Example 2.

Comparative Example 1 A laminate having a layer structure of polyethylene terephthalate film / photopolymerizable coloring layer obtained by removing the photopolymerizable adhesive layer from the image forming sheet of Example 1 was used as an image forming sheet. A display panel was manufactured in the same manner as in Example 1 except that it was used instead.

(Comparative Example 2) The photopolymerizable adhesive composition of the image forming sheet is shown in Table 4 below. Styrene-butadiene copolymer (Tafprene A, manufactured by Asahi Kasei) and Alcon P- which is a tackifying resin. A display panel was manufactured in the same manner as in Example 1 except that the coating liquid for the adhesive layer composition of 90 (manufactured by Arakawa Kagaku) was used.

[0090]

[Table 4]

(Comparative Example 3) The photopolymerization initiator of the photopolymerizable adhesive composition of Example 1 was prepared using 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF, trade name;
Example 1 except that a mixture of 0.2 part of Michler's-ketone and 1.3 parts of benzophenone was used instead of Lucillin TPO).
A display panel was manufactured in the same manner as in.

Table 5 shows the results of the adhesion test and the coloring test performed on the display boards obtained in Examples 1 to 3 and Comparative Examples 2 and 3. (Performance evaluation of display panel)

[0093]

[Table 5]

(1) Adhesion test In accordance with JIS K-5400, a 1 mm square cross cut that reaches the surface of the adhesive layer with an NT cutter is made from the surface opposite to the substrate of the obtained display board, and a heat-resistant acrylic system is used. Adhesive tape
(Sekisui Chemical # 5782) was adhered, then the substrate was fixed and the tape was peeled off, and the presence or absence of peeling between the adhesive layer, the image layer and the transparent resin layer was tested at ambient temperatures of 25 ° C and 90 ° C.

(2) Coloring test Regarding the portion of the obtained display panel where the colored image is not provided, a fading tester for paint (manufactured by Suga Test Instruments Co., Ltd .; trade name: F
M-1) is used to determine the yellowing degree (called Delta E) according to JIS K
According to JIS-7103, a color computer (manufactured by Suga Test Instruments Co., Ltd., trade name; SM-3) was used for measurement according to JIS K-7013.

A base polycarbonate was used as a reference.

The image forming sheet of the present invention has a layer structure of support / photopolymerizable coloring layer / photopolymerizable adhesive layer, and the photopolymerization initiator used in the above photopolymerizable adhesive layer. Since it is an acylphosphine oxide type that has low colorability, it has good adhesion to the substrate when it is laminated on a substrate, exposed and developed to form an image layer, and the image layers are laminated to form a multi-layered full color film. Even when an image is formed, the adhesion between the images is good, and a display board having excellent durability without discoloration can be manufactured.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03F 7/028

Claims (1)

[Claims] 1. An image forming system comprising a transparent support, on one side of which a photopolymerizable colored layer and a photopolymerizable adhesive layer containing an acylphosphine oxide photopolymerization initiator are provided in this order. -G.