JPH07128785A - Material and method for forming image - Google Patents

Abstract

PURPOSE:To obtain the image forming material capable of forming an image good in both of resolution and sensitivity through a safe and simple dry processing by incorporating a specified Co complex compound and a specified dye compound in a layer on a support. CONSTITUTION:The image forming material has a layer contg. the Co complex represented by formula I and the dye represented by formula II, on the support. In formulae I and II, L is a coordination compound forming the complex compound together with a Co cation; m is an integer of 1-6, and when m is >=2, each of plural L may be the same or different; each of R1-R4 is a group combining through a carbon atom with the boron atom; n is 1, 2 or 3, and when n is >=2, each of plural counter anions may be the same or different; Dye<+> is a cationic dye; and X is a counter anion. It is preferred for the image forming material that at least one of L in formula I contains the dye or dye precursor and X in formula II is a boron anion derivative.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel image forming material and an image forming method, and more particularly to a novel image forming material and an image forming method using a cobalt complex having a boron salt as a counter anion and a cationic dye. .

[0002]

2. Description of the Related Art It is known that a cobalt (III) complex is easily reduced by light to a cobalt (II) complex having a low stability constant of a ligand. By utilizing such properties, Japanese Patent Publications No. 54-2091, No. 54-10856, No. 54-10857, etc. show cobalt (III) complex, photoreducing agent and divalent or less cobalt in resin binder. Imaging materials containing compounds that form chelates with are proposed.

The materials described in these patents are excellent in that an image can be formed by a simple dry process, but the cobalt (III) complex itself has poor photosensitivity, and a photoreducing agent such as a naphthoquinone derivative or A spectral sensitizer is used to impart photosensitivity to light with a wavelength longer than 300 nm. However, sufficient sensitivity cannot be obtained only by using the photoreducing agents and spectral sensitizers described therein, and further, writing by scanning exposure with laser light, especially semiconductor laser light, which has been remarkably developed in recent years, is required. Was not practically possible, and the usage of the material was limited.

Further, as another image forming material using a cobalt (III) complex, Japanese Patent Laid-Open No. 2-182701 proposes a photosensitive material containing a complex of cobalt (III) complex cation and borate anion. .

However, this method is used as a photopolymerization initiator in the photopolymerization process and is different from the method of the present invention. Further, it is difficult to obtain an image with gradation.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned problems of the prior art. That is, the first object of the present invention is to provide an image forming material which gives an image having good resolution and sensitivity by a safe and simple dry process.

A second object of the present invention is to provide an image forming material which can be exposed to light having a long wavelength of 500 nm or more and has high sensitivity. A third object of the present invention is to provide an image forming method using this image forming material.

[0008]

As a result of intensive investigations by the present inventors, an image containing a cobalt complex represented by the following general formula [I] and a dye represented by the general formula [II] on a support was obtained. It has been found that the above object can be achieved by the forming material, and the present invention has been completed.

[0009]

[Chemical 2]

In the formula, L represents a coordination compound which forms a complex with a cobalt cation. m represents an integer of 1 to 6, and when m is 2 or more, a plurality of Ls may be the same or different. R ₁ , R ₂ , R ₃ and R ₄ each represent a group bonded to boron through a carbon atom. n represents an integer of 1 to 3, and when n is 2 or more, a plurality of counter anions may be the same or different.

Dye ⁺ represents a cationic dye and X ⁻ represents a counter anion.

In the general formula [I], at least one of L contains a dye or a dye precursor site; in the general formula [I], a group bonded to boron through a carbon atom is an alkyl group or an aryl group. A group, an aralkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or a cyano group; the cobalt complex contains a ligand that can be exchanged with L; in the general formula [I], boron is added via a carbon atom. It is a preferred embodiment of the image-forming material of the present invention that X ⁻ is a boron anion derivative in the general formula [II], and at least one of the groups bonded to is an alkyl group. Treatment; heating after imagewise exposure and subsequent treatment with an acid are preferred embodiments in the image forming method of the present invention.

The cobalt complex compound represented by the above general formula [I] (hereinafter referred to as the cobalt complex of the present invention) will be described in more detail.

L represents a coordination compound which forms a complex with a cobalt cation. In the cobalt complex, the cobalt cation is a Lewis acid, the coordination compound is a Lewis base, and almost all Lewis bases can be used as the coordination compound, but the stability of the cobalt complex and the reaction activity after reduction are preferable. From the point of, it is a bidentate or tridentate ligand.
For example, amines (NH ₃ , ethylenediamine, diethylenetriamine, triethylenetetramine, diaminodiacetate, etc.), bipyridine, glyoximine, β-diketone, etc. and the coordination compounds used in the cobalt complex compound examples of the present invention and JP-A 59 -95529, page 3 can be mentioned.

Typical examples of L are shown below. _{L-1: NH 3 L-} 2: pyridine _{L-3: H 2 NCH 2} CH 2 NH 2 L-4: H 2 NCH 2 CH (CH 3) NH 2 L-5: H 2 NCH 2 CH 2 CH 2 _{NH 2 L-6: CH 3} NHCH 2 CH 2 NHCH 3 L-7: H 2 NCH 2 CH 2 N (CH 3) 2 L-8: H 2 NCH 2 CH (NH 2) CH 2 NH 2 L-9 : H ₂ NCH ₂ CH ₂ NHCH ₃ L-10: H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NH ₂ L-11: H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NH ₂ L-12: N _{(CH 2 CH 2 NH 2)} 3 L-13: H 2 NCH 2 CH (NH 2) CH 2 NH 2 L-14: H 2 NCH 2 CH 2 NHCH 2 CH 2 NHCH 2 CH 2 NHCH 2 CH 2 NH 2 _{L-15: (H 2 NCH} 2 CH 2) 2 NCH 2 CH 2 N (CH 2 CH 2 NH 2) 2 L-16: 2,2'- bipyridine L-17: o-phenanthroline L-18: H ₂ NCSNH ₂ L-20: 2,2′-diaminodiphenyl L-21: P (C ₆ H ₅ ) ₃ L-22: H ₂ NCH ₂ CONH ₂ L-23: C ₃ H ₇ NHCH ₂ CONH ₂ L- 24: H ₂ NCH ₂ CONHC ₃ H ₇ L-25: CH ₃ COC (C ₆ H ₁₃ ) = C (OH) CH ₃ L-26: CH ₃ COCH = C (OH) CH ₃ L-27: CF ₃ COCH = C (OH) CF ₃ L-28: H ₂ NCH ₂ COOH L- 30: Salicylaldehyde L-32: HOOCCOOH L-33: NH (CH ₂ COOH) ₂ L-35: HOSCCSOH L-36: Pyrocatechol

[0016]

[Chemical 3]

[0017]

[Chemical 4]

[0018]

[Chemical 5]

Further, at least one of the coordination compounds may contain a dye moiety. The coordination compound containing a dye moiety means that the coordination compound itself is a dye (containing a coordination atom as a part of the constituent of the dye), or a dye having a group capable of coordination as a substituent. Is. In this case, it is also possible to perform spectral sensitization so as to be sensitive to visible light to infrared light by selecting a dye as a coordination compound, or to form a dye image with a dye or dye precursor as a coordination compound. It is preferable because it is possible. As examples of such a coordination compound, JP-A No. 4-158092, Japanese Patent Application No. 4-107778,
Benzothiazolylazonaphthol described in No. 167793,
Examples thereof include pyridylazonaphthol and phenylazopyrazolotriazole compounds.

At least one of R _{1 to} R ₄ representing a group bonded to boron through a carbon atom is preferably an alkyl group or an aralkyl group, and particularly preferably R ₁ is an alkyl group or an aralkyl group. R _{2 to} R ₄ are an aryl group or a heterocyclic group.

Specific examples of R _{1 to} R ₄ include the groups shown below.

The alkyl group includes straight chain and branched alkyl groups, and examples thereof include methyl, ethyl, butyl, i-butyl, hexyl, octyl and stearyl groups. The alkenyl group preferably has 2 to 20 carbon atoms. The alkynyl group preferably has 2 to 20 carbon atoms. The cycloalkyl group is preferably a 5- to 7-membered ring. A benzyl group is preferred as the aralkyl group.

The heterocyclic group is preferably a heterocyclic group having aromaticity, and examples thereof include a thienyl group. As the aryl group, a phenyl group and a naphthyl group are preferable.

These groups may be further substituted,
As the substituent, a halogen atom, a cyano group, a nitro group, an alkyl group, an aryl group, a hydroxyl group, an amino group (including an alkyl-substituted amino group), an alkoxy group, a carbamoyl group, -COOR ₅ , OCOR ₅ (R ₅ is an alkyl group) Group, an organic group such as an aryl group).

The amount of cobalt complex added varies depending on the type of cobalt complex and the form of use, but is 0.01 per 1 m ^{2 of} material.
~ 5g is preferred.

The following compounds may be mentioned as specific examples of the cobalt complex of the present invention. These compounds are synthesized with reference to the method described in JP-A-59-95529.

[0027]

[Chemical 6]

[0028]

[Chemical 7]

[0029]

[Chemical 8]

[0030]

[Chemical 9]

Next, a dye represented by the general formula [II] (hereinafter,
The dye of the present invention) will be described in detail.

Dye ⁺ represents a cationic dye, and a spectral sensitizing dye for silver halide emulsion known in the field of photographic industry can be used. Examples of such sensitizing dyes include:
U.S. Patents 1,939,201, 2,072,908, 2,739,149
No. 2,213,995, No. 2,493,748, No. 2,519,001, West German Patent 929,080, and British Patent 505,979.

[0033] X ^- is a typical counter anion represented by, Benjireto, thiocyanate, trifluoroacetate, perchlorate, hexafluorophosphate, nitrate, Sarishineto, chloride, fluoride, iodide, but bromide and the like,
A borate derivative is particularly preferable. The borate derivative may be the same as the counter anion of the cobalt complex represented by the general formula [I].

Examples of sensitizing dyes that can be preferably used in the present invention are shown below.

[0035]

[Chemical 10]

[0036]

[Chemical 11]

[0037]

[Chemical 12]

[0038]

[Chemical 13]

[0039]

[Chemical 14]

[0040]

[Chemical 15]

[0041]

[Chemical 16]

[0042]

[Chemical 17]

[0043]

[Chemical 18]

[0044]

[Chemical 19]

The ligand exchange agent used in the present invention is stable in the image forming material without reacting with the trivalent cobalt complex of the present invention, and is reduced in an imagewise manner to have a ligand exchange activity. It is preferable that the ligand is exchanged by heating with the resulting divalent cobalt complex, and an appropriate ligand exchange agent may be selected according to the ligand used in the complex of the present invention. Examples of such a ligand exchange agent include the same as the ligand used in the complex of the present invention.

The amount of the ligand exchange agent added varies depending on the type and usage of the cobalt complex, but is 0.01 per 1 m ^{2 of} the material.
~ 10g is preferred.

As the binder used in the present invention,
Water-soluble binder such as gelatin, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl butyral,
Solvent-soluble polymers such as polyvinyl acetal, nitrocellulose, ethyl cellulose are preferred. These binders may be used in the form of latex dispersion, as well as one or more of them being dissolved in an organic solvent.

The amount of the binder used varies depending on whether it has a single-layer structure or a multi-layer structure depending on the purpose of the image-forming material of the present invention, but is preferably 0.1 to ²⁰ g per 1 m ^{2 of} the support.

For the photosensitive layer of the image-forming material, a coating solution for the photosensitive layer is prepared by dissolving the cobalt complex of the present invention and the sensitizing dye together with a binder in a solvent or dispersing them in the solvent in the form of fine particles. It can be formed by coating on a support and appropriately drying. The dry thickness of the photosensitive layer is preferably 0.1 to 10 μm.

The above-mentioned support has good dimensional stability,
Any material can be used as long as it can withstand heating during development, and it is preferable to use a transparent plastic film support having excellent heat resistance. Specific examples include polymers such as polyethylene terephthalate, polysulfone, polycarbonate, and polyimide. The thickness of the support is usually preferably 10 to 200 μm.

Next, an image forming method using the image forming material of the present invention will be described.

In the image forming method of the present invention, a positive image or a negative image can be formed by selecting the types of the cobalt complex and the ligand exchange agent. First, the case where a colorless cobalt complex is used and a colored ligand exchange agent is used will be described.

When the image-forming material is imagewise exposed to light having a wavelength corresponding to the absorption of the spectral sensitizing dye used in the present invention, a latent image is formed in accordance with the exposure amount, followed by heating (preferably 60 to 180). Then, a positive image is obtained. This color image is superposed on the image receiving sheet and transferred by heat (preferably 80 to 200
C.), the ligand-exchanging agent in the unexposed area is transferred and a negative image is formed on the image-receiving sheet. Further, a positive image can be fixed by treating the image forming material with an acid before thermal transfer.

As the image receiving sheet, a sheet obtained by laminating an image receiving layer on paper or a plastic support having excellent heat resistance is used.

The image-receiving layer may contain various additives in addition to the binder necessary for holding the colored compound by thermal transfer. As the binder, those mentioned in the above-mentioned photosensitive layer may be used, and as an additive, JP-A-59-158289 may be used.
No. 59, No. 182785, No. 60-130735, No. 61-118748,
In order to improve the image durability, it is preferable to contain an ultraviolet absorber and an antioxidant shown in JP-A-61-153638 and JP-A-61-159644.

As further additives, various matting agents,
Colloidal silica, slip agents, organic fluorine compounds, antistatic agents, high-boiling organic solvents, plasticizers, polymer latices and the like can be mentioned.

Further, a metal supply compound (metal source) may be added to the image-receiving layer in order to accelerate the fixing of the transferred ligand exchange agent. Specific examples of preferred metal sources are described in US Pat. No. 4,987,049.

Next, the case where a colored cobalt complex is used and a colorless ligand exchange agent is used will be described.

A negative image is obtained by heating after exposure in the same manner as described above. When this color developed image is superposed on the image receiving sheet by thermal transfer, the colored ligand released from the exposed portion is transferred,
A positive image is formed on the image receiving sheet. Transfer to the image receiving sheet is performed by superposing the image receiving sheet and the image forming material and heating (preferably 80 to 200 ° C.). In the case of treating with an acid, it can be fixed by exposing it to hydrochloric acid gas for about 1 minute, stacking a sheet containing an acid component and heating it, or adding an acid component in another layer and contacting it with heat after exposure. .

The acid component may be an inorganic acid or an organic acid, but typical examples thereof include acetic acid, hydrochloric acid and tosylic acid.

The image-forming material of the present invention may have a layer such as an intermediate layer, a protective layer and an undercoat layer in addition to the photosensitive layer containing a cobalt complex.

For exposure to the image forming material, sunlight, tungsten light, mercury lamp, halogen lamp, xenon lamp, laser light, light emitting diode, CRT or the like can be used.

The image forming material of the present invention is applied to a material capable of spectral sensitized recording by selecting a sensitizing dye to be used.

[0064]

EXAMPLES The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 (Preparation of Image Forming Material) The following raw materials were mixed to obtain a photosensitive layer coating liquid according to the present invention.

Cobalt complex (1) 3.0 g Sensitizing dye (D-14) 0.5 g Ligand exchanger (L-47) 2.3 g Polyvinyl butyral resin (BL-1: Sekisui Chemical Co., Ltd.) 24.0 g Methyl ethyl ketone 150 cc Acetone 30cc Coating solution for the above photosensitive layer is applied and dried on a polyethylene terephthalate (PET) base having a thickness of 100 μm using a wire bar so that the coating amount after drying is 1.4 g / m ² ,
An image forming material 1 having a photosensitive layer on a PET film was prepared.

Similarly, the cobalt complex of the image forming material 1,
Image-forming materials 2 to 7 of the present invention having the same constitution were prepared except that the sensitizing dye and the ligand exchange agent were changed as described below.
For comparison, comparative image-forming materials 8 and 9 in which the cobalt complex of the image-forming material 1 was replaced with the comparative complex A or B and comparative image-forming materials 10 and 11 in which the sensitizing dye and the ligand exchange agent were also replaced were prepared. .

(Image formation and evaluation) The above image forming materials 1 to
11 was exposed with a xenon lamp equipped with a filter that overlaps image wedges and cuts light of 500 nm or less. When each image-forming material was heated at 130 ° C. for 5 seconds after exposure, the materials 1 to 7 of the present invention were able to form a blue positive image different from the background color in the exposed area, but comparative materials 8 and 9 were used. No image formation was observed.

The transmission density of the image measured with red light is shown below.

Image Forming Material Co Complex Sensitizing Dye Ligand Exchanger Dmax Dmin 1 (Invention) (1) D-14 L-47 0.63 0.20 2 (Invention) (2) D-24 L-47 0.85 0.21 3 (present invention) (5) D-20 L-47 0.83 0.21 4 (present invention) (12) D-17 L-47 0.56 0.22 5 (present invention) (1) D-43 L-47 0.80 0.21 6 ( The present invention (1) D-39 L-47 0.65 0.20 7 (present invention) (1) D-14 L-43 0.73 0.20 8 (comparative example) (A) D-14 L-47 0.24 0.22 9 (comparative example) ) (B) D-14 L-47 0.23 0.22 10 (comparative example) (A) D-29 L-43 0.23 0.23 11 (comparative example) (A) D-24 L-47 0.22 0.21 Comparative complex A: Co ( _{NH 2 CH 2 CH 2 NH 2} ) 3 (CF 3 COO) 3 comparison complex _{B: Co (NH 2 CH 2} CH 2 NH 2) 3 (BF 4) 3 example 2 100 [mu] m stretched porous white PET film (Dia Iruhekisuto made: W900J) on, and coating and drying the image receiving layer forming composition having the following composition to prepare a receiving sheet having an image receiving layer having a dry thickness of 10.0 [mu] m.

Ethylcellulose (Hercules: N-14) 11 parts Ni ₂ ⁺ [CH ₃ COCH (COOCH ₃ ) COC ₇ H ₁₅ ] ₂ 6 parts Dioctyl phthalate 2 parts Silicone-based resin (X-24- 8300) 1 part Methyl ethyl ketone 80 parts Next, the positive image obtained in Example 1 and the above-mentioned image-receiving sheet are faced to each other, and heated / pressurized with a heat roll (170 ° C./2 k
(g / cm ² · 2.5 mm / sec), the ligand-exchanging agent in the unexposed area was transferred onto the image-receiving sheet in the present invention to obtain a blue negative image. On the other hand, in the comparative example, the entire surface was transferred and the image could not be obtained.

The results of measuring the concentration in the same manner as in Example 1 are shown below.

Image Forming Material Co Complex Sensitizing Dye Ligand Exchanger Dmax Dmin 1 (Invention) (1) D-14 L-47 0.73 0.10 2 (Invention) (2) D-24 L-47 0.80 0.12 3 (present invention) (5) D-20 L-47 0.81 0.14 4 (present invention) (12) D-17 L-47 0.66 0.13 5 (present invention) (1) D-43 L-47 0.75 0.15 6 ( Present Invention (1) D-39 L-47 0.68 0.11 7 (Invention) (1) D-14 L-43 0.70 0.15 8 (Comparative Example) (A) D-14 L-47 0.69 0.70 9 (Comparative Example) ) (B) D-14 L-47 0.73 0.72 10 (comparative example) (A) D-29 L-43 0.70 0.69 11 (comparative example) (A) D-24 L-47 0.72 0.71 Example 3 The following raw materials An image forming material 12 was prepared in the same manner as in Example 1 by using the photosensitive layer coating liquid according to the present invention in which

Cobalt complex (16) 3.0 g Sensitizing dye (D-14) 0.5 g Ligand exchanger (L-16) 2.3 g Polyvinyl butyral resin (BL-1: Sekisui Chemical Co., Ltd.) 24.0 g Methyl ethyl ketone 150 cc Acetone 30 cc Exposure and heating were carried out in the same manner as in Example 1 to obtain an image in which the exposed portion was discolored. Next, when it was superposed on the image-receiving sheet prepared in Example 2 and transferred under the same conditions, a blue positive image transferred by the exposed part was obtained. That is, according to the present invention, it is understood that a negative or positive image can be easily obtained depending on the structure.

Example 4 An image forming material 13 was prepared in the same manner except that the sensitizing dye D-43 was used in place of the sensitizing dye used in Example 3. The image forming material 13 was subjected to scanning exposure using a semiconductor laser (wavelength 820 nm). The exposure energy on the image forming material was 0.5 mJ / cm ² .

After exposure, heating was performed in the same manner as in Example 1, and a black image was obtained corresponding to the exposed area.

A comparative image-forming material 14 was prepared by replacing the cobalt complex of the image-forming material 13 with the comparative cobalt complex (C), and exposed and developed in the same manner as for the above-mentioned image-forming material 13. No image formation was observed with the image forming material 14.

[0078]

[Chemical 20]

[0079]

As shown in the above embodiments, according to the present invention, an image can be formed with high sensitivity even with light of 500 nm or more by a simple dry development process. Further, the thermal transfer process can form a stable image without contamination on the background. Further, by selecting an appropriate ligand or ligand exchange agent, yellow, magenta, and cyan images can be formed, and thus, full-color images and monochrome images can be processed. Further, it is possible to provide a material which can be written with light of long wavelength such as a semiconductor laser.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yamato Komamura Konica Stock Company, 1 Sakura-cho, Hino-shi, Tokyo In-house

Claims (9)

[Claims] 1. An image forming material comprising a support and a cobalt complex represented by the following general formula [I] and a dye represented by the general formula [II]. [Chemical 1] [In the formula, L represents a coordination compound that forms a complex with a cobalt cation. m represents an integer of 1 to 6, and when m is 2 or more, a plurality of Ls may be the same or different.
R ₁ , R ₂ , R ₃ and R ₄ each represent a group bonded to boron through a carbon atom. n represents an integer of 1 to 3, and when n is 2 or more, a plurality of counter anions may be the same or different. Dye ⁺ represents a cationic dye, and X ⁻ represents a counter anion. ] 2. The image forming material according to claim 1, wherein at least one of L in the general formula [I] contains a dye or a dye precursor site. 3. In the general formula [I], the group bonded to boron through a carbon atom is an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or a cyano group. The image forming material according to claim 1. 4. The image forming material according to claim 1, wherein the cobalt complex contains a ligand exchangeable with L. 5. The image forming material according to claim 1, wherein in the general formula [I], at least one of the groups bonded to boron through a carbon atom is an alkyl group. 6. The image forming material according to claim 1, wherein X ⁻ in the general formula [II] is a boron anion derivative. 7. An image-forming material containing a cobalt complex represented by the general formula [I] and a dye represented by the general formula [II] is imagewise exposed on a support, and the exposed area is exposed to light. An image forming method, which comprises heating after forming an image accordingly. 8. The image forming method according to claim 7, further comprising treating with an acid after the imagewise exposure. 9. The image forming method according to claim 7, wherein the imagewise exposure is followed by heating and subsequent treatment with an acid.