JPH06278377A - Photosensitive coloring sheet - Google Patents

Abstract

PURPOSE:To obtain a photosensitive coloring sheet provided with a non-coloring transparent thermally fusing layer having no adhesion at a room temperature, exhibiting superior thermal fusion properties at the time of thermal transfer, and never generating color fogging. CONSTITUTION:In a photosensitive coloring sheet 2 formed by laminating a thermally fusing layer 22 and a photosensitive coloring layer 21 on a substrate 23 in this order, the aforesaid thermally fusing layer 22 is made of a resin composition composed of 100 pts.wt. alcohol-soluble polyamide resin and 1-30 pts.wt. sulfonamide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive colored sheet used for manufacturing a display panel having a predetermined colored image pattern formed on a substrate. The obtained display board is
It can be used for instrument panels of various devices and dials of vehicle speedometers.

[0002]

2. Description of the Related Art Conventionally, characters and numbers on a dial such as a meter are often formed on a substrate by printing, and screen printing is widely used. However, in recent years, as the trend toward higher grades and diversification of products have advanced,
Adds a sense of quality to images such as these letters and numbers,
In order to improve decorativeness and visibility, studies are underway to make images multicolored.

However, in multicolor printing by screen printing, a plate is required for each color, which complicates the printing process and requires drying and curing of the ink for each printing of one color, thus increasing the working speed. There was a problem of being late.

Further, in the offset printing suitable for multicolor printing at high speed, it is difficult to thicken the coating film, so that there is a problem that a sufficient color density for use as a display panel cannot be obtained. .

Further, in the pattern formation by screen printing, since the ink used is a solvent type liquid, the solvent filled in the working environment becomes a source of offensive odor and it is necessary to always pay attention to the danger of explosion or fire. There was a problem.

Further, there is a problem in that the printing ink remains on the plate due to the evaporation of the solvent and causes clogging of the plate, and that it takes time to adjust the viscosity suitable for screen printing. Further, when a plate having a coarse mesh is used so that the printing ink does not become clogged in the plate, there is a problem that only a multicolor image having a low resolution can be obtained.

Therefore, in recent years, a photopolymerizable ink has been proposed for the purpose of eliminating the solvent and shortening the curing time.
However, in order to adjust the viscosity suitable for screen printing, it is necessary to add a reactive diluent such as a low molecular weight monomer to the photopolymerizable ink, which shows the same behavior as a solvent and does not react. Was volatilized with time from the coating film.

Further, the addition of such a reactive diluent reduces the molecular weight of the photopolymerizable ink as a whole,
There are drawbacks that the shrinkage during curing is large and the adhesiveness is deteriorated and the flexibility is lacking, and it cannot be said that it is sufficient from the practical point of view.

To solve these problems, for example, JP-A-59-97140 discloses a method for forming a multicolor image using a colored photopolymerizable resin composition.

In the above method, (1) a halftone dot photomask in which a desired image is color-separated in advance is prepared, and (2) a photopolymerizable resin composition having a corresponding color is obtained through the photomask. The resulting photopolymerizable resin sheet (photosensitive coloring sheet) is irradiated with an actinic ray to be exposed and cured.
(3) The uncured portion is removed by development to form a color-separated halftone image pattern on the photopolymerizable resin sheet.
(4) The obtained halftone dot image pattern is transferred onto the image-receiving sheet having photopolymerization for each color. (5) Next, the halftone dot image pattern of each color formed on the image-receiving sheet. Is re-transferred onto a substrate, and then the image-receiving sheet is photo-cured to form a desired image.

The above-mentioned photosensitive colored sheet is formed on a temporary support,
1) A heat-fusible layer having a heat-fusible property and 2) a photosensitive colored layer formed from a colored photopolymerizable resin composition are laminated in this order. Here, it is possible to display an arbitrary color by using a combination of a photopolymerizable composition containing a colorant such as yellow, magenta, or cyan as the colored photopolymerizable composition.

The reason why the photosensitive colored sheet is provided on the heat-fusible layer instead of directly on the temporary support is that the halftone image is temporarily supported when the halftone images of respective colors are aligned and transferred. This is because it can be completely transferred without being left on the body, and the adhesion between halftone dot images is enhanced. That is, since the heat-fusible layer is transferred together, the halftone dot image does not remain on the temporary support.

Therefore, the heat-fusible layer is required to have no adhesiveness at room temperature and to exhibit an excellent heat-fusion property at the time of thermal transfer. Further, the heat-fusible layer is photosensitively colored. When the layer is coated, it is required that it is not attacked by the solvent used for the photosensitive colored layer (does not cause color cast), has no colorability, and is transparent.

According to the above method, the problems associated with screen printing and photopolymerizable ink are solved, and since the surface of the image is covered with the photosensitive receiving sheet, residual tack and damage on the surface can be prevented. There is.

As the above-mentioned photosensitive colored sheet, Japanese Patent Laid-Open No. Sho 61-61
JP-A-188537 discloses a laminate in which a peelable layer having heat fusion property (heat fusion layer) and a photosensitive resin layer are laminated in this order on a temporary support. In layers
A resin composition comprising an alcohol-soluble polyamide and a hydroxystyrene polymer is used.

However, the above-mentioned resin composition cannot obtain sufficient thermal adhesiveness, and the adhesiveness between the transferred and laminated color images is deteriorated, and the hydroxy content in the resin composition is increased in an attempt to enhance the thermal adhesiveness. When the ratio of the styrene polymer is increased, the entire photosensitive resin layer is colored light yellow due to the color peculiar to the polymer, or the peelable layer is attacked by the solvent used in the photosensitive resin layer, resulting in color fogging. There was a problem such as.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is that it has no adhesiveness at room temperature, exhibits excellent heat-sealing property at the time of thermal transfer and causes color cast. Another object of the present invention is to provide a photosensitive colored sheet having a transparent heat-fusible layer having no coloring property.

[0018]

The photosensitive colored sheet of the present invention comprises a support, and a heat-fusible layer and a photosensitive colored layer laminated in this order.

The support used in the present invention is preferably chemically and thermally stable, and examples thereof include polyesters such as polyethylene terephthalate (hereinafter referred to as PET); polyolefins such as polyethylene and polypropylene; polyvinyl chloride. Polyvinyl halides such as polyvinylidene chloride; polyamides; resin films such as polycarbonates, and biaxially oriented polyethylene terephthalate film are particularly preferable.

As the above-mentioned support, at the time of thermal transfer,
In order to improve the releasability between the support and the heat-fusible layer to be described later, a release agent treated with a silicone-based or fluorine-based release agent is preferable.

The heat fusible layer is formed of a resin composition containing alcohol-soluble polyamide and sulfonamide.

As the above alcohol-soluble polyamide, the polyamide disclosed in JP-A-61-188537 can be used. That is, a linear polyamide synthesized from a dibasic fatty acid and a diamine, an ω-amino acid, a lactam or a derivative thereof by a known method may be mentioned, and any homopolymer or copolymer thereof may be used. In addition, the above-mentioned polyamide has a substituent on the carbon atom of the main chain, or C- on the main chain.
Polyamides containing bonds other than C-bonds and C-N-C bonds can also be used.

Specific examples of the above polyamides include nylon-3, nylon-4, nylon-5, nylon-6,
Nylon-8, Nylon-11, Nylon-12, Nylon-13, Nylon-6 / 6, Nylon-6 / 10,
Nylon-13 / 13, linear homopolyamides such as polymers of metaxylylenediamine and adipic acid, copolymers of trimethylhexamethylenediamine and terephthalic acid, polymers of 1,4-diaminomethylcyclohexane and suberic acid; Nylon 6 / 6-6, Nylon 6 / 6-6 / 6-
10, nylon 6 / 6-6 / 6-10 / 10-6-12, nylon 6 / 6-6 / 12, ε-caprolactam / hexamethylenediamine / 4,4′-diaminodicyclohexylmethane copolymerized polyamide; Examples thereof include N-methylol-substituted, N-alkoxyalkyl-substituted, and N-allyloxyalkyl-substituted derivatives of the homopolyamide and the copolymer polyamide. Such polyamides may be used alone or in combination of two or more.

Examples of commercially available products of the alcohol-soluble polyamide include "Amilan CM-400" manufactured by Toray Industries, Inc.
0 ”,“ Amilan CM-8000 ”and the like.

The above-mentioned sulfonamides include o-toluene sulfonamide, p-toluene sulfonamide, N-
Ethyl-o-toluenesulfonamide, N-ethyl-p
-Toluenesulfonamide, N-methyl-o-toluenesulfonamide, N-methyl-p-toluenesulfonamide, N-methylbenzenesulfonamide, N-butylbenzenesulfonamide and N-cyclohexyl-p-
Toluenesulfonamide and the like may be used, and these may be used alone or in combination of two or more kinds.

When the content of sulfonamide in the above resin composition is small, the effect of improving the heat fusion property is not obtained.
If the amount is too large, color cast or bleeding occurs and surface tackiness occurs.
The amount is limited to 1 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 00 parts by weight.

The photosensitive colored layer comprises a photopolymerizable resin composition comprising (a) a linear copolymer, (b) a photopolymerizable unsaturated compound, (c) a photopolymerization initiator and (d) a colorant. Preferably, it is formed from an object.

The above linear copolymer (a) is one that is soluble or swellable in an alkaline aqueous solution and contains an α, β-unsaturated ethylenic monomer containing a carboxyl group and an α other than the above. , .Beta.-unsaturated ethylenic monomers are preferred.

The α, β-unsaturated ethylenic monomer containing a carboxyl group may be a monomer containing a carboxyl group and copolymerizable with the α, β-unsaturated ethylenic monomer. For example, unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid (including anhydride), fumaric acid and itaconic acid may be mentioned.

Examples of α, β-unsaturated ethylenic monomers other than the above are, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-
Styrenes such as methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-hexylstyrene, pn-octylstyrene, p-methoxystyrene, p-phenylstyrene, and 3,4-dimethylchlorostyrene. Vinylnaphthalenes such as α-vinylnaphthalene; ethylene, propylene, butylene or C _{5 to} C ₃₀
And higher α-olefins; vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl butyrate; methyl (meth) acrylate, (meth ) Propyl acrylate, (meth) acrylic acid-n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-n-
Octyl, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid-2
-(Meth) acrylic acid esters such as chloroethyl, methyl α-chloro (meth) acrylate, phenyl (meth) acrylate and dimethylaminoethyl (meth) acrylate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; Vinyl ketones such as vinyl methyl ketone and vinyl ethyl ketone; N-vinyl compounds such as N-vinyl pyrrole and N-vinyl indole;
(Meth) acrylonitrile; (meth) acrylic acid amides.

In the constituent components of the linear copolymer (a), the amount of the portion corresponding to the α, β-unsaturated ethylenic monomer containing a carboxyl group becomes insoluble in the alkaline aqueous solution when the amount becomes small. , It becomes impossible to develop with an alkaline aqueous solution, and if the amount becomes large, the compatibility with the coating solvent or other components decreases, and the resolution also decreases, so 10-40 wt% is preferable, and 15-35 wt% is more preferable. Is.

When the molecular weight of the linear copolymer (a) is small, so-called cold flow is likely to occur, and when it is large, the linear copolymer (a) is difficult to be dissolved in an alkaline aqueous solution to be difficult to develop and the resolution is also lowered. Therefore, the weight average molecular weight is preferably in the range of 20,000 to 300,000, more preferably 50,000 to 200,000.

As the method for producing the linear copolymer (a), any method may be adopted, and for example, it can be easily obtained by radical polymerization or the like in an organic solvent.

The unsaturated compound (b) is photopolymerizable, and is a urethane acrylate oligomer represented by the following general formula (1) or a liquid at room temperature which can be cured by starting a polymerization reaction by actinic rays. The photopolymerizable monomer and the like are preferable.

[0035]

[Chemical 1] In the general formula (1), R ¹ is a divalent hydrocarbon group, m is an integer of 5 to 100, n is an integer of 1 to 15, and X is a carbon number 2.
To 20 divalent hydrocarbon groups, respectively, and A is represented by the following general formula (2), (3) or (4).

[0036]

[Chemical 2] In the general formulas (2) to (4), R ² , R ³ and R ⁴ represent a hydrogen atom or a methyl group.

The divalent hydrocarbon group represented by R ¹ is a hydrocarbon group composed of straight chain, branched chain, alicyclic or aromatic moieties, for example, ethylene group, propylene group, Examples include neopentyl group and the like.

The divalent hydrocarbon group represented by X is a hydrocarbon group composed of a straight chain, branched chain, alicyclic or aromatic moiety, such as a hexamethylene group or a tolylene group, Examples thereof include isophorone group.

Any method may be used for producing the urethane acrylate oligomer represented by the above general formula (1). For example, diisocyanate and diol are mixed and reacted at a ratio matching the composition ratio of the desired compound. After forming a urethane oligomer having an isocyanate group at the terminal, a (meth) acrylate having a hydroxyl group may be added and reacted with the isocyanate group at the terminal. On this occasion,
If necessary, the reaction may be carried out by dissolving in an organic solvent such as ethyl acetate, methyl ethyl ketone, or toluene, and a catalyst such as dibutyltin dilaurate may be added.

When the weight average molecular weight of the urethane acrylate oligomer increases, the amount of unsaturated groups relatively decreases, the photocurability deteriorates, and the sensitivity decreases.
It is preferably 50,000 or less, more preferably 8,000
It is the following.

Examples of the photopolymerizable monomer that is liquid at room temperature include polyfunctional and monofunctional (meth) acrylate monomers; polyester acrylate oligomers.

Examples of the polyfunctional (meth) acrylate monomer include, for example, triethylene glycol (meth).
Acrylate, tetraethylene glycol di (meth) acrylate, 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 tri (meth) acrylate,
Dipentaerythritol penta (meth) acrylate,
Dipentaerythritol hexa (meth) acrylate,
Trimethylolpropane tri (meth) acrylate,
2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 3-phenoxy-2-
Examples thereof include propanoyl acrylate and 1,6-bis [3-acryloxy-2-hydroxypropyl] hexyl ether.

Examples of the monofunctional (meth) acrylate monomer include methyl (meth) acrylate monomer and benzyl (meth) acrylate monomer.

When the content of the unsaturated compound (b) in the photopolymerizable resin composition is low, the surface hardness after exposure is insufficient, and when it is high, cold flow is likely to occur. Therefore, the linear copolymer is used. (A) 1 to 100 parts by weight
0 to 200 parts by weight is preferable, more preferably 30 to 1
It is 50 parts by weight.

The photopolymerization initiator (c) may be any one having the property of activating the unsaturated compound (b) by actinic rays such as ultraviolet rays and visible rays to initiate polymerization.

Among the above photopolymerization initiators (c), those which are activated by ultraviolet rays include, for example, sodium methyldithiocarbamate sulfide, tetramethylthiuram monosulfide, diphenylmonosulfide, dibenzothiazoyl monosulfide and disulfide. Sulfides such as; thioxanthone derivatives such as thioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, and 2,4-diethylthioxanthone; (di) azo compounds such as hydrazone, azobisisobutyronitrile, benzenediazonium; benzoin, benzoin Methyl ether, benzoin ethyl ether, benzophenone, dimethylaminobenzophenone, Michler's ketone,
Benzyl anthraquinone, t-butyl anthraquinone,
Aromatic carbonyl compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-aminoanthraquinone, 2-chloroanthraquinone, benzyldimethylketal, methylphenylglyoxylate; methyl p-dimethylaminobenzoate, p-dimethylaminobenzoic acid Dialkylaminobenzoic acid esters such as ethyl, butyl p-dimethylaminobenzoate and isopropyl p-diethylaminobenzoate; benzoyl peroxide, di-
t-butyl peroxide, dicumyl peroxide,
Peroxides such as cumene hydroperoxide; acridine derivatives such as 9-phenylacridine, 9-p-methoxyphenylacridine, 9-acetylaminoacridine and benzacridine; 9,10-dimethylbenzphenazine, 9-methylbenzphenazine, Phenazine derivatives such as 10-methoxybenzphenazine; 6,4 ′,
Quinoxaline derivatives such as 4 ″ -trimethoxy-2,3-diphenylquinoxaline; 2,4,5-triphenylimidazoyl dimer; halogenated ketones; acylated phosphorus compounds such as acylphosphine oxide and acylphosphonate. Can be mentioned.

Further, those which are activated by visible light include, for example, 2-nitrofluorene, 2,4,6-triphenylpyrylyl boron tetrafluoride salt, 2,4,6-tris (trichloromethyl)- 1,3,5-triazine,
3,3′-carbonylbiscoumarin, thiomichler ketone and the like can be mentioned.

In the above photopolymerizable resin composition, when the content of the photopolymerization initiator (c) is small, the curing time is long and the image cannot be formed due to insufficient curing, and when it is large, the cured photopolymerization is caused. Of the linear resin (a), since the resin composition yellows or becomes brittle,
0.1 to 10 parts by weight is preferable.

As the colorant (d), conventionally known pigments and dyes can be used, and at least four types of yellow, magenta, cyan and black are listed.

Examples of the yellow pigments include Hansa Yellow, Benzidine Yellow, Cadmium Yellow, Yellow Lead G, Zinc Chromate, Lemon Yellow, Strocian Yellow, Indian Yellow and Isoindolinone Yellow.

Examples of the magenta pigments include rhodamine B lake, cadmium red, red iron oxide, chrome vermillion, pyrazolone red, resole red, red lead, watching red, quinacridone red and the like.

Examples of the cyan pigments include ultramarine blue, Prussian blue, cobalt blue, cerulean blue, manganese blue, and phthalocyanine blue.

Examples of the black pigment include carbon black.

In the photopolymerizable resin composition, the above colorant (d)
When the content of the linear copolymer (a) is too small, the color density becomes low and sufficient coloring cannot be performed, and when the content is too large, the amount of the coloring agent that is not involved in the curing of the image becomes large. The range of 1 to 300 parts by weight is preferable.

Further, a plasticizer such as dioctyl phthalate, triethylene glycol diacetate, p-toluene sulfonamide, N-ethyltoluene sulfonamide or the like is added to the above photopolymerizable resin composition; thermal polymerization of hydroquinone or p-methoxyphenol or the like. Inhibitors; stabilizers; ultraviolet absorbers; antioxidants; solvents such as methyl ethyl ketone (MEK) and toluene may be added.

As a method for producing the above-mentioned photosensitive colored sheet, for example, a diluted solution of the resin composition for a heat-fusible layer is formed on a film-shaped support such as PET or stretched polypropylene so as to have a constant thickness. After casting and drying to form a heat-fusible layer, the dilute solution of the photopolymerizable resin composition is cast on the heat-fusible layer so as to have a constant thickness, dried, and exposed to light. The method of forming a colored layer is mentioned.

A protective layer may be provided on the side of the photosensitive colored layer opposite to the surface in contact with the heat-sealing layer in order to reduce oxygen damage during exposure. Examples of the protective layer include a laminate of a transparent film or sheet such as PET or oriented polypropylene (hereinafter referred to as OPP); and a coating of a dilute solution of a resin soluble in a developing solution (alkaline aqueous solution) such as polyvinyl alcohol. .

Examples of the solvent for diluting the resin composition for the heat-fusible layer include methanol, ethanol, n-propanol, isopropanol, n-butanol and se.
Lower aliphatic alcohols such as c-butanol, isobutanol and tert-butanol; mixed solvent of the lower aliphatic alcohol and aromatic alcohols such as phenol or benzyl alcohol; the lower aliphatic alcohol and methyl cellosolve or ethyl cellosolve And the like, mixed solvents with cellosolves such as; and the like, mixed solvents with the lower aliphatic alcohol and ethylene glycol, propylene glycol, formic acid, or water. However, when a mixed solvent is used, it is preferable that the lower aliphatic alcohol is contained in an amount of 50% by weight or more from the viewpoint of solution stability.

The thickness of the heat-fusible layer is not particularly limited, but if it becomes thin, it becomes difficult to handle and sufficient adhesive force cannot be obtained, and when the halftone image is laminated, the image is heat-fused. It is not fully embedded in the agent layer and entraps air bubbles.
When the thickness is increased, the distance between the halftone dot images of the respective colors formed on the heat-fusible layer may be increased and the images may be displaced from each other. 20 μm is preferable.

As a solvent for diluting the photopolymerizable resin composition, a solvent that does not swell or dissolve the heat-fusible layer is preferable. For example, methyl ethyl ketone (ME
K), toluene and the like are preferably used.

The thickness of the above-mentioned photosensitive colored layer is preferably 0.5 to 20 μm, because it becomes difficult to handle when it is thin and sufficient color density cannot be obtained, and peeling easily occurs between the layers when it is thick.

In the present invention, four types of photosensitive colored sheets having at least yellow, magenta, cyan and black photosensitive colored layers are prepared. It is also possible to change the gradation of light and shade by setting the color density per sheet of the photosensitive coloring sheet to be low and adjusting the number of sheets to be overlapped.

In the present invention, the photosensitive colored sheet is exposed through a halftone dot image pattern corresponding to each color and cured, and then the uncured portion is removed by development to give a colored halftone dot image on the support. A pattern is formed, and the halftone dot image pattern is transferred and laminated on the image receiving sheet for each color while peeling the support. Next, the halftone dot image pattern on the image receiving sheet is retransferred onto the substrate to form an image of the colored halftone dot image pattern on the substrate.

The above-mentioned image receiving sheet is one in which an image receiving layer comprising a photocurable resin composition or a thermoplastic resin is formed on a support. As the above support, PET, O
A resin film such as PP may be used.

The photocurable resin composition is preferably one containing the linear copolymer (a), the photopolymerizable unsaturated compound (b) and the photopolymerization initiator (c) as constituent components. .

In the above photocurable resin composition, when the amount of the unsaturated compound (b) is small, the surface hardness after exposure becomes insufficient, and when it is large, cold flow easily occurs.
10 to 200 relative to 100 parts by weight of the linear copolymer (a).
Weight part is preferable, More preferably, it is 30 to 150 weight part.

The photopolymerization initiator (c) has a property of activating the unsaturated compound (b) by actinic rays such as ultraviolet rays and visible rays to initiate polymerization, and is used in the photosensitive colored layer. The same photopolymerization initiator as described above can be used. In particular, an acylphosphine oxide-based photopolymerization initiator is preferable in that the yellowing of the image receiving sheet is low.

Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoylphenylphosphine oxide ("Lucirin TPO" manufactured by BASF), pivaloyldiphenylphosphine oxide, and 2-methylbenzoyldiphenyl. Phosphine oxide, terephthaloyl-bis-diphenylphosphine oxide, 1-methyl-cyclohexylcarbonyldiphenylphosphine oxide, versatoyl-diphenylphosphine oxide, 4-methylbenzoyl-phenylphosphinic acid methyl ester, 2,4,6-trimethylbenzoyl-phosphinic acid diethyl ester Esters and the like can be mentioned.

The photopolymerization initiator (c) may be used alone, but may be used in combination with a photopolymerization initiation aid in order to accelerate the curing rate and alleviate oxygen damage. Examples of the photopolymerization initiation assistant include triethanolamine and dialkylaminobenzoic acid esters.

Examples of photopolymerization initiation assistants other than the above include, for example, sulfides such as dibenzothiazoyl monosulfide; thioxanthone derivatives such as 2,4-diethylthioxanthone; (di) azo compounds such as benzenediazonium; benzyl. Aromatic carbonyl compounds such as dimethyl ketal; Acetophenone derivatives such as α-hydroxy-α, α'-dimethylacetophenone; Peroxides such as dicumyl peroxide; Acridine derivatives such as benzacridine; Phenazines such as 9-methylbenzphenazine Derivative; 6,4 ', 4 "-trimethoxy-2,3-
Quinosaline derivatives such as diphenylquinosaline; 2,4
5-triphenylimidazoyl dimer; halogenated ketone; 2,4,6-tris (trichloromethyl) -1,
3,5-triazine and the like can be mentioned.

In the above photocurable resin composition, when the amount of the photopolymerization initiator (c) is small, the curing time is long and the curing is insufficient so that an image cannot be formed and the residual amount of the unsaturated group remains. And the weather resistance deteriorates. Further, when the amount is large, the cured composition becomes yellow or becomes brittle, so 0.1 to 10 parts by weight is preferable with respect to 100 parts by weight of the linear copolymer (a).

As the thermoplastic resin used in the image receiving layer, when the softening temperature is low, workability during image transfer is deteriorated, and when it is high, thermal deformation of the support occurs during image transfer. Is preferable, and more preferably 30 to 100 ° C.

Examples of the thermoplastic resin include polyolefins; copolymers of polyolefins with the above α, β-unsaturated carboxylic acids, and those obtained by crosslinking the copolymers with metal ions; polyvinylidene chloride and its products. Copolymer; polyacrylonitrile; poly-N-vinylcarbazole; polyvinyl alcohol; poly-N-vinylpyrrolidone; polyamide; polyurethane; ethylene-vinyl acetate copolymer; styrene-butadiene copolymer; acrylonitrile-butadiene copolymer; Styrene-isoprene copolymer; butyl rubber; acrylic resin and the like.

The image-receiving layer contains dioctyl phthalate, triethylene glycol diacetate, p-
Plasticizers such as toluenesulfonamide and N-ethyltoluenesulfonamide; thermal polymerization inhibitors such as hydroquinone and p-methoxyphenol; stabilizers; UV absorbers; antioxidants; solvents such as methyl ethyl ketone (MEK) and toluene. It may be added.

In order to prepare the image receiving sheet, for example, a dilute solution of the photocurable resin composition or the thermoplastic resin is formed on a resin film support such as PET or OPP to a constant thickness. Examples of the method include casting and drying to form an image receiving layer. The support may be previously subjected to a release treatment with a silicone-based release agent or the like.

Examples of the solvent used for the diluted solution include ethyl ethyl ketone and toluene.

If the thickness of the image receiving sheet becomes thin, it becomes difficult to handle and the colored halftone dot image transferred onto the receiving sheet becomes difficult to transfer.
Is preferred. When an image receiving sheet having a thickness of more than 200 μm is required, it is preferable to use a plurality of image receiving sheets in superposition.

<Method for forming halftone dot image pattern> Next, a method for forming a halftone dot image pattern using the photosensitive colored sheet of the present invention will be described. As shown in FIG. 1, the photosensitive colored sheet 2 has a heat-fusible layer 22 and a photosensitive colored layer 21 laminated in this order on a support 23, and the photosensitive colored layer 21 is a protective layer. Protected by 1.

First, an original image is converted into yellow, magenta, cyan, and black halftone dots in advance by a color separation machine, and color shades are converted into halftone dots and large and small colors of yellow, magenta, cyan, and black. Prepare a halftone dot negative mask.

Next, as shown in FIG. 2, on the photosensitive colored layer side 21 of the photosensitive colored sheet 2 colored black,
The halftone dot negative mask 3 color-separated into black is overlapped and exposed from the protective layer 1 side of the PET film to cure the photosensitive colored layer 21.

Next, the protective layer 1 is peeled off, and the unexposed portion of the photosensitive colored layer 21 is dissolved and removed by alkali development, so that a black net is formed on the heat-fusible layer 22, as shown in FIG. A halftone dot image pattern 4 corresponding to the point negative mask 3 is formed. When polyvinyl alcohol is used as the protective layer 1, it can be removed during alkali development.

Next, the same operation as described above is repeated to form halftone dot image patterns corresponding to cyan, magenta and yellow, respectively, on the photosensitive colored sheets colored in cyan, magenta and yellow. In this way, a halftone dot image pattern can be formed using at least four color photosensitive coloring sheets of yellow, magenta, cyan and black.

In the above description, the four-color photosensitive colored sheet was used, but it is not necessarily limited to four colors, and other colors (for example, white, intermediate colors, etc.) may be used as required. The characteristic coloring sheets may be laminated and a halftone dot negative mask corresponding to this color may be used to form a halftone dot image pattern corresponding to the negative mask.

The light source for exposing the above-mentioned photosensitive colored layer is not particularly limited, and a conventionally known light source can be used, for example, an ultrahigh pressure mercury lamp, a metal halide lamp or the like is preferably used.

The developing solution used for development is
Although not particularly limited, for example, an aqueous solution of sodium carbonate having a concentration of 0.5 to 5% by weight is preferably used. The developing device used for development is not particularly limited, and a known device can be used.

<Method of Transferring Halftone Image Pattern to Image Receiving Sheet> In the present invention, the halftone image pattern obtained above is transferred onto the image receiving sheet while peeling the support for each color, Match and stack. First, as shown in FIG. 5, the black dot image pattern 4 formed on the heat-fusible layer 22 is transferred to the image receiving layer 5 of the image receiving sheet 5.
The support 23 is peeled off while the halftone image pattern 4 is fused to the image receiving layer 51 by superimposing so that the 1 touches each other, pressurizing and heating.

Then, as shown in FIG. 6, the cyan halftone dot image pattern 6 is brought into contact with the heat-fusible layer 22.
The support 23 is peeled off while the halftone dot image pattern 6 is fused and heat-bonded with the black halftone dot image pattern 4 while being aligned with the black dot image pattern 4.

By repeating the above operation, finally, as shown in FIG. 7, on the image receiving sheet 5, black, cyan,
Halftone dot image pattern 4 of four colors of magenta and yellow,
A laminate in which 7, 6 and 4 are laminated on the base material 11 in this order is obtained.

A method for laminating the photosensitive colored sheet 2 having the halftone dot image pattern 4 and the image receiving sheet 5, and a photosensitive colored sheet having the halftone dot image pattern 4 and the halftone dot image pattern of another color. As a laminating method of (1), for example, a method of heating and fusing while applying pressure by the laminating roll 9 can be mentioned. At this time, the temperature of the laminating roll 9 is
It is determined depending on the heat resistance of the substrate 11 used, the softening temperature of the photosensitive colored sheet 2 and the image receiving sheet 5, and the like, but a range of 50 to 130 ° C. is generally preferable.

<Retransfer Method of Image Pattern on Substrate>
As shown in FIG. 7, the yellow image pattern 8 side of the halftone dot image pattern laminate laminated on the image receiving sheet 5 is overlapped with the adhesive layer 10 provided on the base 11, and the pressure is applied. While the heat-fusible layer 22 of the yellow image pattern 8 and the adhesive layer 10 are fused by heating, the support 52 is peeled off. By such an operation, as shown in FIG. 8, the laminate is transferred onto the substrate 11 to obtain a display board on which a colored image is formed on the substrate 11.

Further, when a photosensitive resin composition is used for the image receiving layer 51, a sufficient amount of light is irradiated to cure the image receiving layer 51. If the support 23 is light-transmissive, the support 2 can be re-transferred to the base 11 again.
Light may be irradiated before peeling off 3. In this case, oxygen damage is prevented by the support 23, and the peeling operation of the support 52 is facilitated because the image receiving layer 51 is cured.

When the irradiation amount of light at this time is small, the curing is insufficient and the surface hardness is insufficient, the obtained image is easily scratched, and when the irradiation amount is large, yellowing may occur.
4,000 mJ / cm ² is preferred.

The substrate is not particularly limited, but is, for example, a plate-like body such as an acrylic resin, a polycarbonate resin, a polyethylene terephthalate (hereinafter referred to as PET) resin; a glass plate; a ceramic plate; a metal plate. Etc. are suitable, and are selected in consideration of necessary characteristics such as flexibility, transparency and heat resistance. A primer layer may be provided on the base material in advance in order to improve adhesion, or an adhesive may be applied, and the base body may be colored. Good.

EXAMPLES The present invention will be described below based on examples. (Example 1) 1) Preparation of photosensitive colored sheet (a) Preparation of resin composition for heat-fusible layer-90 parts by weight of alcohol-soluble polyamide ("CM-8000" manufactured by Toray Industries, Inc.)-N-ethyl-p -Toluenesulfonamide 10 parts by weight The above components were dissolved in 900 parts by weight of methanol to obtain a solution of the composition for heat fusible layer.

(B) Preparation of Resin Composition for Photosensitive Coloring Layer 100 parts by weight of linear copolymer (methyl methacrylate / methacrylic acid-n-butyl / methacrylic acid-2-ethylhexyl / methacrylic acid = 31/31 / 13/25 [weight ratio], weight average molecular weight = 100,000 (hereinafter referred to as linear copolymer P) -Unsaturated compound (trimethylolpropane triacrylate) 67 parts by weight-Photopolymerization initiator 1.5 parts by weight (Ingredient: 2,4,6-trimethylbenzoyldiphenyl phosphine oxide, "Lucirin TPO" manufactured by BASF) ・ Yellow-based pigment ("FPF-27E Yellow" manufactured by Dainichiseika Co., Ltd.) 10 parts by weight or-Magenta pigment (Dainichiseido Chemical "FPF-96Q Red") 10 parts by weight or-Cyan-based pigment (Dainichi Seika's "FPF-CP2 Blue") 10 parts by weight or -Black pigment ("FPF-40S Black" manufactured by Dainichiseika Co., Ltd.) 10 parts by weight Each of the above components is dissolved in 400 parts by weight of MEK, and the photosensitive colored layer is colored yellow, magenta, cyan and black respectively. A solution of the resin composition was obtained.

(C) Preparation of Photosensitive Colored Sheet First, heat fusion was performed on a PET film support having a thickness of 75 μm.
After casting the solution of the resin composition for a conductive layer, the temperature is 100 ° C. for 5 minutes.
And heat-fusible layer with a thickness of 2μm after drying.
It was Then, on this heat-fusible layer, photosensitive coloring of each color
Each solution of the resin composition for layers is cast, and at 60 ° C. for 1 minute.
After that, after drying for 1 minute at 80 ℃, the thickness after drying
5 μm yellow, magenta, cyan and black
4 types each with a colored photosensitive coloring layer
A (color) photosensitive colored sheet was obtained. Furthermore, four kinds of feelings
Mold release treatment with a thickness of 6 μm on the photo-colored layer
The PET film so that the release surface is in contact.
90 ° C, 5kg / cm ², At a speed of 2 m / min
It thermocompression-bonded by the minator and provided the protective layer.

2) Preparation of image receiving sheet (a) Preparation of photopolymerizable unsaturated compound A four-necked flask equipped with a reflux condenser, a dropping funnel, a thermometer and a mechanical stirrer was charged with 504 weight of hexamethylene diisocyanate. Parts (3 molar equivalents), 826 parts by weight of dry MEK and 1 part by weight of dibutyltin dilaurate (catalyst) as a solvent are added and polyethylene glycol 916 parts by weight (2 molar equivalents, average molecular weight: 45) with stirring.
8) was added and the mixture was refluxed for 5 hours. Next, 596 parts by weight of pentaerythritol triacrylate (2 molar equivalents) was added dropwise, and after refluxing for another 5 hours to react, MEK was evaporated to obtain a photopolymerizable unsaturated compound (hereinafter referred to as U-1). It was [This unsaturated compound has the following formula (1): X = (CH ₂ ) ₆ , R ¹ = (CH ₂ ) ₂ , m = 10,
n = 2, R ² = H (where A corresponds to general formula (2)),
The weight average molecular weight was 2016. ]

(B) Preparation of Resin Composition for Image Receiving Layer 100 parts by weight of linear copolymer P 100 parts by weight of unsaturated compound (U-1) Unsaturated compound (“R- manufactured by Nippon Kayaku Co., Ltd.” 167 ") 50 parts by weight Photopolymerization initiator (" Lucirin TPO "manufactured by BASF) 1.5 parts by weight The above components were dissolved in 400 parts by weight of MEK to obtain a solution of a resin composition for an image receiving layer. .

(C) Preparation of Image Receiving Sheet A solution of the resin composition for the image receiving layer was cast on a PET film support having a thickness of 75 μm, dried at 80 ° C. for 5 minutes, and then dried. An image receiving sheet having an image receiving layer having a size of 25 μm was obtained.

3) Preparation of Adhesive Layer Sheet A solution identical to the resin composition for the image receiving layer except that tetraethylene glycol diacrylate was used instead of "R-167" as the unsaturated compound 75 μm
After being cast on the PET film and dried at 80 ° C. for 5 minutes, an adhesive layer sheet having a thickness after drying of 5 μm was obtained.

4) Formation of halftone dot image pattern First, a halftone dot negative mask corresponding to a black image is superposed on the protective layer of the photosensitive colored sheet colored in black, and it is exposed to 400 mJ / cm ^{2 with} an ultrahigh pressure mercury lamp. After irradiating light to cure the photosensitive colored layer, the protective layer is peeled off, and 2 kg / cm of a 1% sodium carbonate aqueous solution at 25 ° C.
^The unexposed portion was dissolved and removed by spraying at a pressure of ² for 45 seconds to obtain a halftone dot image pattern corresponding to a black halftone negative mask. Next, the photosensitive colored sheets colored in cyan, magenta, and yellow were used, and exposed and developed in the same manner as above to form halftone dot image patterns corresponding to cyan, magenta, and yellow, respectively.

5) Transfer of the halftone dot image pattern to the image receiving sheet After the black halftone dot image pattern was superposed on the image receiving layer of the image receiving sheet, it was pressed with a laminating roll and heated (110 ° C., 4 kg). / Cm ² , speed 2 m / min), and the halftone image pattern was transferred to the image receiving layer while peeling the support. Next, the cyan halftone dot image pattern and the black heat-fusible layer were superposed so that they were in contact with each other, and the image pattern was transferred by pressing and heating with a laminating roll. By repeating such an operation, black, cyan, magenta, and yellow 4 are formed on the photosensitive receiving sheet.
A halftone dot image pattern laminated body composed of color halftone dot image patterns was obtained.

6) Transfer of halftone dot image pattern laminated body onto substrate Substrate for adhesive layer is placed on a white polycarbonate plate substrate having a thickness of 1 mm, pressure is applied by a laminator roll and heat is applied to fuse the adhesive layer. Was set up. Then, the heat-fusible layer of the yellow dot image pattern of the laminate is overlaid on the adhesive layer, and the laminate roll is pressed and heated,
The above laminate was fused to the adhesive layer. Next, light of 200 mJ / cm ² was irradiated from the substrate side with an ultrahigh pressure mercury lamp to cure the image receiving layer and the adhesive layer, and then the support of the image receiving sheet was peeled off to obtain a display board. The irradiation amount of light is 50 mJ / cm ^{2 of} another sample in advance, and the cumulative irradiation amount until the surface hardness reaches the pencil hardness H is measured, and the irradiation amount corresponding to the cumulative irradiation amount is measured. Irradiated.

7) Performance Evaluation With respect to the photosensitive colored sheet, display board, etc. obtained above,
The following evaluation tests (a) to (d) were conducted, and the evaluation results are shown in Table 1. (A) Color fogging property Regarding the non-image area (unexposed area) of the display board obtained in 6) above, color stains (color) due to pigments generated when a photosensitive coloring layer is applied onto the heat-fusible layer. The presence or absence of fogging) was visually observed and evaluated according to the following criteria. If the solvent is not applied during the coating of the photosensitive colored layer, the heat-fusible layer will not be stained by the pigment. No: There is no stain due to the pigment when the photosensitive colored layer is coated on the heat-fusible layer. Existence: The heat-fusible layer has stains due to the pigment at the time of coating the photosensitive coloring layer.

(B) Surface Tack When transferring the halftone dot image pattern of the above 5) to the image receiving sheet, the presence or absence of tack in the heat-fusible layer was evaluated according to the following criteria. ◯: No tack and easy to align during alignment. Δ: There is slight tack, but alignment is possible during alignment. ×: There is tack, and alignment cannot be performed during alignment.

(C) Transparency (Measurement of Yellowing Degree) After casting a solution of the resin composition for a heat-fusible layer on a PET film having a thickness of 75 μm, it was dried at 100 ° C. for 5 minutes,
A sample having a heat-fusible layer having a thickness of 8 μm after drying was prepared. Using a "SM-3 Color Computer" manufactured by Suga Test Instruments Co., Ltd., the yellowness of this sample was measured by a reflection method in accordance with JIS K7103, and the color difference (ΔE) from the yellowness of the blank below was measured. Was used as an index of transparency. As a blank, 100 parts by weight of alcohol-soluble polyamide ("Amilan CM-800" manufactured by Toray Industries, Inc.) was added to 900 parts of methanol.
The solution dissolved in parts by weight was cast on a PET film having a thickness of 75 μm, dried at 100 ° C. for 5 minutes, and a sample having a heat-fusible layer having a thickness of 8 μm after drying was used.

(D) Thermal fusion bondability (measurement of adhesive strength) When a halftone dot image pattern was prepared by the above 4), the display board obtained by exposing the entire surface without placing a halftone negative mask was used.
A sample was cut into 5 mm and a length of 300 mm. A width of 25 m is applied to the upper surface of the image receiving layer of this sample through a double-sided adhesive tape (“# 595” manufactured by Sekisui Chemical Co., Ltd., the same size as the sample).
2kg of polyester film with m and length of 330mm
It was pasted at a speed of 300 mm / min with the pressure bonding roller. Next, one end of the base body of the display board was fixed, and one end of the polyester film was attached to a tensile tester (“AUT manufactured by Shimadzu Corporation”).
OGRAGH AG-5000B ") fixed to a movable part, and peeled in a direction of 180 degrees at a pulling speed of 300 mm / min under conditions of 23 ° C and 65% RH, and a peel resistance is an adhesive force (g / 25 mm). And

(Examples 2 to 4, Comparative Examples 1 to 8) Except that the kinds and blending amounts of alcohol-soluble polyamide and sulfonamide in the resin composition for the photosensitive colored layer were changed as shown in Table 1. After the photosensitive colored sheet, the image receiving sheet and the display board were prepared in the same manner as in Example 1, the above performance evaluations (a) to (d) were performed, and the results are shown in Table 1.

[0108]

[Table 1]

[0109]

As described above, the photosensitive colored sheet of the present invention has no adhesiveness at room temperature and can be easily aligned, exhibits excellent heat-fusion property during thermal transfer, and does not cause color cast. Since the transparent heat-sealing layer having no coloring property is provided, a display panel in which a portion without an image is excellent in colorless transparency is provided.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a photosensitive colored sheet of the present invention.

FIG. 2 is a schematic cross-sectional view showing a state in which a photosensitive colored sheet is exposed through a halftone negative mask.

FIG. 3 is a schematic sectional view showing a black halftone dot image pattern formed on a photosensitive colored sheet.

FIG. 4 is a schematic cross-sectional view showing an image receiving sheet.

FIG. 5 is a schematic cross-sectional view showing a state in which a black halftone dot image pattern is transferred onto an image receiving sheet.

FIG. 6 is a schematic cross-sectional view showing a state in which a cyan halftone dot image pattern is transferred onto a black halftone dot image pattern.

FIG. 7 is a schematic cross-sectional view showing a halftone dot image pattern of black, cyan, magenta and yellow laminated on an image receiving sheet.

FIG. 8 is a schematic cross-sectional view showing a state in which a halftone dot image pattern laminate of black, cyan, magenta and yellow laminated on an image receiving sheet is retransferred to a substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective layer 10 Adhesive layer 11 Substrate 2 Photosensitive coloring sheet 21 Photosensitive coloring layer 22 Heat-fusible layer 23 Support 3 Halftone dot negative mask 4 Black halftone image pattern 5 Image receiving sheet 51 Image receiving layer 52 Support Body 6 Cyan dot image pattern 7 Magenta dot image pattern 8 Yellow dot image pattern 9 Laminating roll

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03F 7/028 7/11 503

Claims (1)

[Claims] 1. A photosensitive colored sheet comprising a support and a heat-fusible layer and a photosensitive colored layer laminated in this order, wherein the heat-fusible layer comprises alcohol-soluble polyamide 1
A photosensitive colored sheet comprising a resin composition comprising 00 parts by weight and 1 to 30 parts by weight of a sulfonamide.