JPH02181745A - Image forming medium - Google Patents

Abstract

PURPOSE:To obtain an image forming medium capable of exposing imagewise with laser beams by a compact simple device and sufficient in storage stability by using the medium containing photosensitive silver halide, an organic silver salt, and a reducing agent, and having a nonlinear optical function. CONSTITUTION:The image forming medium to be used comprises the photosensitive silver halide, the organic silver salt, and the reducing agent, and has the nonlinear optical function capable of emitting a secondary higher harmonics (SHG light) from at least one part of the basic wave of the laser beams upon being irradiated with the laser beams, thus permitting the obtained medium to record an image by the SHG light emitted from itself without requiring any nonlinear optical device in the laser device, and not to need any difficult spectral sensitization of the medium to the semiconductor laser wavelength region, and accordingly, deterioration of storage stability due to the spectral sensitization to be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-developable dry silver salt-based imaging medium.

(Prior Art) Among the various image forming methods known in the past, the image forming method using silver salt (silver salt photography) has a high sensitivity, resolution,
This is one of the most excellent methods in terms of sensitivity stability. However, this silver salt photography method involves complicated processing, such as the use of liquid for development and fixing operations.

As a method that does not require such wet processing and has excellent sensitivity, resolution, and storage stability, it is possible to
There is a heat-developable dry silver salt image forming method that performs image exposure (contact exposure, projection exposure, digital exposure, etc.), thermal amplification by heating, and the like.

Digital exposure using a laser is considered important as image exposure for the above-mentioned image forming medium because image information can be processed as a signal and laser technology, which has made significant progress in recent years, can be applied. Furthermore, it is desired to use a semiconductor laser from the viewpoint of miniaturizing the device.

(Problems to be Solved by the Invention) In order to perform imagewise exposure using a laser, it is necessary to spectrally sensitize the heat-developable dry silver salt to the laser wavelength range.However,
It is difficult to sufficiently sensitize dry silver salt to the semiconductor laser wavelength range. Spectrally sensitized imaging media also have the disadvantage of poor storage stability.

However, if a nonlinear optical element is used to generate the second harmonic of a laser beam (SHG light) and image exposure is performed using the SHG light, the thermal developability is difficult and deteriorates storage stability. The need for dry silver salt spectral sensitization is eliminated. However, in that case, since a nonlinear optical element must be used in the recording device, there is a problem that the device becomes larger and more complicated.

An object of the present invention is to provide an image forming medium that can be subjected to laser image exposure using a small and simple device and has sufficient storage stability.

[Means to solve the problem]

As a result of extensive studies to achieve the above object, the present inventors discovered that it is very effective to impart a nonlinear optical function to a heat-developable silver salt-based image forming medium, and have developed the present invention. It was completed.

That is, the present invention is an image forming medium characterized by containing a photosensitive silver halide, an organic silver salt, and a reducing agent, and having a nonlinear optical function.

Note that the nonlinear optical function as used in the present invention refers to a function that can generate a second harmonic (SHG light) from at least a part of the laser light (fundamental wave) when irradiated with a laser.

When the medium of the present invention is irradiated with laser light, SH is generated within the medium.
Since G light is generated, image recording using SHG light is possible without providing a nonlinear optical element in the laser device.

Since image recording is performed using SHG light, difficult spectral sensitization of the medium up to the semiconductor laser wavelength range is not necessarily required, and therefore, there is no reduction in storage stability caused by spectral sensitization.

It is clear that recording with SHG light on conventionally known recording media (OPC materials, photoresist materials, diazo materials, etc.) brings about various advantages such as improved resolution and expanded material selectivity. Of course, such advantages also occur in the recording medium of the present invention.

Furthermore, since the medium of the present invention contains silver halide, it has sufficient sensitivity for practical use even if the conversion efficiency is low and the power of the generated IG light is low.

For example, if the image forming medium of the present invention described above is subjected to (1) imagewise exposure with a laser beam to generate silver nuclei, and (2) thermally amplifies the medium by heating the medium after or simultaneously with the imagewise exposure, It is possible to form images made of metallic silver according to the irradiation pattern.

Note that thermal amplification is to cause an oxidation-reduction reaction between an organic silver salt and a reducing agent using a silver nucleus as a catalyst, and to grow (amplify) metallic silver in the area where the silver nucleus exists due to the reaction.

Moreover, it is a preferable embodiment that the medium of the present invention further contains a material (hereinafter referred to as a heat conversion material) that absorbs the fundamental wave of laser light and the like.

The reason why the medium of the above embodiment is preferable will be described. When the medium in this mode is irradiated with laser light, S
HG light is generated, and the SHG light generates silver nuclei from silver halide contained in the medium. At the same time, S
Fundamental waves and the like that are not converted into HG light are absorbed by the heat conversion material and generate heat, which thermally amplifies the silver nuclei and forms a silver image made of metallic silver. That is, (1) image exposure and (2) thermal amplification can be performed by -degree laser irradiation, and no heating means is required in the recording apparatus. In addition, in the medium of this embodiment, (1) and (2) can also be performed as separate steps using light.

In that case, the laser irradiation in step (2) should use a laser wavelength that is not converted to SHG light, or a laser wavelength that is not within the photosensitivity of silver halide even if converted to SHG light. good. It is also preferable to perform laser irradiation through a filter layer that cuts unnecessary wavelengths.

It is also a preferred embodiment for the medium of the present invention to contain a polymerizable polymer precursor and a photopolymerization initiator. This is because the process (2) in which the polymerizable polymer precursor contained in the medium is photopolymerized by exposure to form a polymer image (for example, in the above process (2), the reducing agent and its oxidized product are distributed, etc. This is because the polymerization occurs site-selectively depending on the distribution of the difference in polymerization inhibiting ability, and a polymer image can be formed.

If the medium of the above embodiment is used, (1) image exposure, (2) thermal amplification, and (2) polymerization necessary for image formation can all be performed by exposure. Therefore, an image can be formed using a recording device having only an exposure means (without a heating means). Furthermore, since the steps (1) to (4) can be performed continuously, it is also possible to shorten the image forming time.

In particular, it is preferable to carry out (1) and (2) at the same time.

Hereinafter, the structure of the image forming medium of the present invention will be explained in detail.

Silver halide, which the medium of the present invention contains as an essential component,
As organic silver salts and reducing agents, for example, JP-A-61-69
No. 062, JP-A-62-70838, JP-A-43-4
Examples include those described in Japanese Patent Publication No. 921, Japanese Patent Publication No. 43-4924, and the like.

The preferred blending ratio of the above components in the medium of the present invention is as follows.

Preferably 0 silver halide per 1 mol of organic silver
．． 001 mol to 2 mol, more preferably 0.05 mol to
It is desirable to contain 0.4 mol. In addition, organic silver 1
It is desirable to contain the reducing agent in an amount of preferably 0.05 mol to 3 mol, more preferably 0.42 mol to 1.3 mol, based on the mole. In addition, when obtaining a polymerized image, the preferred blending ratio of the polymerizable polymer precursor and photopolymerization initiator to be added is preferably 0.1 ffiffi parts to 30 Ji It is desirable to use parts by weight, more preferably 0.5 parts by weight to 10 parts by weight. In addition, the polymerization initiator is preferably 0.01 mol to 10 mol, more preferably 0.01 mol to 10 mol, and more preferably 0.
．． It is desirable to contain 5 mol to 3 mol.

Examples of the photopolymerization initiator include carbonyl compounds, sulfur compounds, halogen compounds, redox photopolymerization initiators, and peroxide initiators sensitized with dyes such as biryllium.

Specifically, carbonyl compounds include diketones such as benzyl, 4.4'-dimethoxybenzyl, diacetyl, and camphorquinone; benzophenones such as 4,4'-diethylaminobenzophenone and 4.4'-dimethoxybenzophenone; : For example, acetophenones such as acetophenone and 4-methoxyacetophenone; For example, benzoin alkyl ethers; For example, 2
- Thioxanthone such as cyclothioxanthone, 2,5-diethylthioxanthone, thioxanthone-3-carboxylic acid-β-methoxyethyl ester; chalcone and styryl ketone having dialkylamino group=
3,3°-carbonylbis(7-medoxycoumarin),
Examples include coumarins such as 3.3'-carbonylbis(7-dinithylaminocoumarin).

Sulfur compounds include dibenzothiazolyl sulfide,
Examples include disulfides such as decylphenyl sulfide.

Examples of halogen compounds include carbon tetrabromide, quinolinesulfonyl chloride, and S-
Examples include triazines.

Redox-based photopolymerization initiators include those used in combination with trivalent iron ion compounds (e.g. ferric ammonium citrate) and peroxide, and those used in combination with photoreducible dyes such as riboflavin and methylene blue and triethanolamine. , and those using a combination of reducing agents such as ascorbic acid.

Furthermore, among the photopolymerization initiators described above, two or more types can be combined to obtain a more efficient photopolymerization reaction.

Examples of such a combination of photopolymerization initiators include a combination of chalcone, styryl ketones, or coumarins having a dialkylamino group, and s-triazines or camphorquinone having a triheromethyl group.

As the polymerizable polymer precursor contained in the medium of the present invention, compounds having at least one reactive vinyl group in the molecule can be used, such as reactive vinyl group-containing monomers, reactive vinyl group-containing oligomers, etc. and reactive vinyl group-containing polymers can be used.

In order to provide the image forming medium of the present invention with a nonlinear optical function, for example, a layer having a nonlinear optical function may be laminated on a recording layer containing a silver salt or the like. The nonlinear optical function layer may contain a compound having a nonlinear optical function. However, the present invention is not limited thereto; for example, the recording layer may directly contain a compound having a nonlinear optical function. In that case, the composition ratio should be such that it does not significantly impair the photosensitivity of the silver salt, etc.
In addition, the composition ratio may be set to such an extent that a nonlinear optical function can be imparted to the medium. Its composition varies depending on the type of compound.

The nonlinear optical function refers to the function of converting the wavelength of laser light into a linear or linear wavelength, and examples of compounds having such a function include the following.

Organic crystals Urea, α-resorcinol, m-nitroaniline, 3-methyl-4-nitropyridine-1-oxide, etc. Polymers Polyvinylidene fluoride, poly(vinylidene cyanide-vinyl acetate), etc. Polymer compositions Polyoxyethylene Polymer liquid crystal composition Cl13 ct+, in which p-nitroaniline is dissolved in poly-ε-caprolactam.

Liquid Crystal Decyloxybenzylideneanilide-2-methylbutyl-cinnamate, pentyloxycyanobiphenyl The inorganic and organic crystals need to be single crystallized for use, and also have a low optical damage threshold for incident laser light. . In comparison, polymers, polymer liquid crystals, polymer compositions, and polymer liquid crystal compositions are preferable because they are easy to form into devices and have a large nonlinear optical function.

A typical polymer composition is one in which a compound with a large molecular nonlinear optical function is added to a polyoxyalkylene matrix and the molecules are arranged.

Specifically, polyoxyalkylene is represented by the following formula 1%. In the formula, R represents an alkylene group having 1 to 6 carbon atoms, and n is 1
0 to 200,000.

As R, an alkylene group having 1 to 6 carbon atoms can be used, but if the number of carbon atoms is 7 or more, the compatibility with a compound having an electron-withdrawing substituent and an electron-donating substituent decreases, so that an excellent It is not possible to obtain a film with physical properties. Among these, polyoxyalkylene in which R has 2 to 4 carbon atoms is particularly preferred.

The polyoxyalkylene is effective even if it is only a part of the matrix, and can also be used by introducing it into other compounds by copolymerization or by mixing it with other compounds by blending.

The following methods are available for introduction by copolymerization.

■ Use as a side chain of the main chain polymer as shown in the following general formula (I).

More specifically, compounds having polyoxyalkylene include the following.

, R+COO+ ROh “C00Rz (R represents a C3-C6 alkylene group.

R+, Rt represents a C4-C2° alkyl group, n
=2~1oooo) In this case, the polyoxyalkylene represented by +R-0)- may be bonded to at least a part of the main chain represented by ÷8su. It may also have a crosslinked structure.

■As shown in the general formula (Il) below, a repeating unit is used as the main chain to construct and utilize one A-+R-0±; B+R-OtTc dimension R-0...
......1n) A, B, C... may each have the same structure or may have different structures.

■A structure in which the structures of ■ and ■ above constitute a cyclic structure N5 (R represents an alkylene group of 01 to C6.

R! 1. R4 represents H or a C3-C2° alkyl group. n, nl = 2~100QO)) 10-t-
R, 0 person] "10 Ra OF-r-+830') TT-
H (R1, R2, R3 represent C1 to C6 alkylene groups. n, n,, R2, = 2 to 100000) -(-C)
IrC1)1 0+R-0±d1 (R represents a C3-C6 alkylene group. Entity = 10-
200000, m = 10~100000°X is H1
Indicates CH3 or a halogen group. ) ■ (R is C+ "' Ca alkylene group, n=1o~t
ooooo, R1 represents a C4 to C18 alkylene group, cyclohexylene group, phenylene group, biphenylene group, or toluylene group.

m = 10-10000) (R is a C1-C8 alkylene group, n = 10-1000
0G and R1 represent a C1 to C38 alkylene group, cyclohexylene group, phenylene group, biphenylene group, terphenylene group, or tolylene group. m = 1. o~100
00) Examples of large molecules having a nonlinear optical function that can be mixed into the polyoxyalkylene matrix represented by the above include mono-substituted benzene derivatives, tri-substituted benzene derivatives, tetra-substituted benzene derivatives, mono-substituted biphenyl derivatives, and di-substituted biphenyl derivatives. Derivatives, tri-substituted biphenyl derivatives, tetra-substituted biphenyl derivatives, mono-substituted naphthalene derivatives, di-substituted naphthalene derivatives, tri-substituted naphthalene derivatives, tetra-substituted naphthalene derivatives, mono-substituted pyridine derivatives, di-substituted pyridine derivatives, tri-substituted pyridine derivatives, tetra-substituted pyridine Derivatives, mono-substituted pyrazine derivatives, di-substituted pyrazine derivatives, tri-substituted pyrazine conductors, tetra-substituted pyrazine derivatives, mono-substituted pyrimidine derivatives, di-substituted pyrimidine derivatives, tri-substituted pyrimidine derivatives, tetra-substituted pyrimidine derivatives, mono-substituted azulene derivatives, di-substituted Azulene derivatives, tri-substituted azulene derivatives, tetra-substituted azulene derivatives, mono-substituted virol derivatives, di-substituted virol derivatives, tri-substituted virol derivatives, tetra-substituted virol derivatives, mono-substituted thiophene derivatives, di-substituted thiophene derivatives, tri-substituted thiophene derivatives, tetra-substituted virol derivatives Thiophene derivatives, mono-substituted furan derivatives, di-substituted furan derivatives, tri-substituted furan derivatives, tetra-substituted furan derivatives, mono-substituted biryllium salt derivatives, di-substituted biryllium salt derivatives, tri-substituted pyrylium salt derivatives, tetra-substituted biryllium salt derivatives, mono-substituted quinolines derivatives, di-substituted quinoline derivatives, tri-substituted quinoline derivatives, tetra-substituted quinoline derivatives, mono-substituted pyridazine derivatives, di-substituted pyridazine derivatives, tri-substituted pyridazine derivatives, tetra-substituted pyridazine derivatives, mono-substituted triazine derivatives, di-substituted triazine derivatives, Tri-substituted triazine derivatives, mono-substituted tetrazine derivatives, di-substituted tetrazine derivatives, mono-substituted anthracene derivatives,
Di-substituted anthracene derivatives, tri-substituted anthracene derivatives, and tetra-substituted anthracene derivatives can be used.

These compounds have electron donating substituents, more specifically amino groups, alkyl groups (methyl, ethyl, isopropyl, n-propyl, n-butyl, t-butyl,
5ec-butyl, n-octyl, di-octyl, rhohexyl, cyclohexyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), alkylamino (N-methylamino, N-ethylamino, N-propylamino, N -butylamino), hydroxyalkylamino group (N-hydroxymethylamino, N
-(2-hydroxyethyl)amino, N-(2-hydroxypropyl)amino, N-(3-hydroxypropyl)amino, N-(4-hydroxy)butylamino, etc.), dialkylamino group (N,N-dimethyl amino, N,N-diethylamino, N,N-dipropylamino, N,N-dibutylamino, N-methyl-N-ditylamino, N-methyl-N-pro-ruamino, etc.), hydroxyalkyl-alkylamine u (N-hydroxymethyl-N-methylamino, N-hydroxymethyl-N-ethylamino, N-hydroxymethyl-N-ethylamino, N-(2-hydroxyethyl)-N-methylamino, N-(2- hydroxyethyl)-N-ethylamino, N-(3-hydroxypropyl)-N-
Methylamino, N-(2-hydroxypropyl)-N
-ethylamino, N-(4-hydroxybutyl)-N
-butylamino), dihydroxyalkylamino groups (N,N-dihydroxymethylamino, N,N-di(2-hydroxyethyl)amino, N,N-di(
2-hydroxypropyl)amino,N,N-di(3
-hydroxybrivyl)amino, N-hydroxymethyl-N-(2-hydroxyethyl)amino, etc.),
There are mercapto, hydroxy or proton groups.

In addition, these compounds have electron-withdrawing substituents,
More specifically, there are a nitro group, a cyano group, a halogen atom (chlorine atom, a bromine atom), a trifluoromethyl group, a carboxyl group, a carboxyester group, a carbonyl group, or a sulfonyl group.

Nonlinear optical materials, which are polymeric compositions containing such compounds, are soluble in solvents such as acetonitrile and benzene, and have excellent film formation and coating properties.

Further, the heat conversion material contained in the medium of one embodiment of the present invention described above is not particularly limited as long as it is a material capable of heat conversion as described above, but for example, inorganic metals or organic dyes may be used. can be mentioned.

Inorganic metals generally include Sn, Sb, Pb, and B.
i, As, Zn, Cd, In, Au, At, Cu, T
Other examples include Te-Se compounds containing Se and C components, Te-C compounds, and carbon black.

Examples of organic dyes include polymethine dyes, azulene dyes, merocyanine dyes, cyanine dyes, rhodamine dyes, naphthoquinone dyes, biryllium dyes, phthalocyanine dyes, naphthalocyanine dyes,
Examples include fluorene dyes, triarylamine dyes, triarylaminium dyes, triaryldiimonium dyes, azo dyes, and metal chelate compounds.

In the image forming medium of the present invention described in detail above, images are recorded by laser irradiation, and examples of materials that can be used as basic laser light for laser irradiation include, for example:
YAG laser (wavelength 1.01i4um), ruby laser (690 parts m), Nd” Nigaras laser (
1,054-1.062μm), color center laser, ion-doped crystal laser (700-2200nm)
Solid-state lasers such as He-Ne laser (633rv),
e laser (2,03 μm), A r ” laser (48B, 515 parts m), K r + laser (
647 parts m), HF laser (2,8~3.3u
m), gas lasers such as iodine lasers (1.32 μm), dye lasers (0.3 to 1.6 μm), semiconductor lasers (0.7 to 1.5 μm), and the like. Among these, semiconductor lasers are used as recording devices for the medium of the present invention because they are easy to modulate and are very compact.

In particular, the image forming medium of the present invention can be used for autofocus by detecting the fundamental wave of laser light as reflected light or transmitted light with a photodetector, and can be used in a high-resolution printer with a simple configuration. It is very useful.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. In addition, in the following description, "part" is based on weight.

Example 1 First, 3 parts of behenic acid was dissolved in 60 parts of toluene, and then 5 parts of silver behenate was added in a dark room and dispersed for 7 minutes at 6000 rpm using a homomixer. Then silver bromide 0.
7 parts, polyvinyl butyral (product name: Extran B
3 parts of M-1 (manufactured by Sekisui Chemical Co., Ltd.) were added, and stirring was continued for 2 hours. Then, while heating to 35°C, adipic acid 0.5
1 part, and 0.8 part of phthalazinone were added thereto, and the mixture was stirred for 30 minutes to obtain Solution A.

Separately, 0.9 parts of Michler's ketone and 0.9 parts of ethyl p-dimethylaminobenzoate were added to 40 parts of toluene.
4 parts, 25 parts of trimethylolpropane acrylate, 4 parts
- 0.6 part of methoxynaphthol, and the following structure (a)
0.005 part of the dye was added to obtain Solution B.

CH2CH2CI (,50311) The liquid A and liquid B were mixed, applied to a PET (polyethylene terephthalate) film, and dried to obtain an image forming layer with a thickness of 4 scales.

Separately, 10 parts of poly-ε-caprolactone and 5 parts of p-nitroaniline were dissolved in 50 parts of benzene and coated on a PET film to a thickness of 15Q to form a nonlinear optical functional film. did.

Next, this nonlinear optical function film and the image forming layer were superimposed to complete the image forming medium of the present invention.

The nonlinear optical function film side of this image forming medium was irradiated with light converged to a spot diameter of about 2 am using a YAG laser. When the film was then heated for 8 seconds on a hot plate adjusted to 110°C, the exposed area turned black.

Subsequently, the entire surface of the film was exposed from the image forming layer side to an ultra-high pressure mercury lamp for 3 seconds. When the nonlinear optical function film is peeled off and the image forming layer is etched in ethanol, YAG
Although the laser-exposed portions were dissolved, the unexposed portions were not dissolved, and a polymer image corresponding to imagewise exposure could be obtained.

Example 2 The image forming medium of the present invention was prepared in the same manner as in Example 1, except that the PET film for forming the image forming layer (liquid A and liquid B) was changed to a PET film kneaded with 10% by weight of carbon black. was created. After this was exposed in the same manner as in Example 1, the nonlinear optical function film was peeled off and the entire surface was exposed, and the same good results were obtained.

Example 3 An image forming medium of the present invention was produced in the same manner as in Example 1, except that polyoxyethylene was used instead of poly-ε-caprolactone to form a nonlinear optical function film with a thickness of 17 ul. When similar recording was performed, similar good results were obtained.

(Effects of the Invention) As described above, since the image forming medium of the present invention has a nonlinear optical function, SMC light is generated by laser irradiation, and the SMC light is used for recording. Therefore, without providing a nonlinear optical element in the laser device, S
Image recording using MC light becomes possible. Since image recording is performed using SMC light, difficult spectral sensitization of the medium up to the semiconductor laser wavelength range is not necessarily required, and therefore, there is no reduction in storage stability caused by spectral sensitization.

Claims (1)

[Scope of Claims] 1) An image forming medium containing a photosensitive silver halide, an organic silver salt, and a reducing agent, and having a nonlinear optical function. 2) The image forming medium according to claim 1, comprising a polymerizable polymer precursor and a photopolymerization initiator. 3) The image forming medium according to claim 1 or 2, further comprising a layer that absorbs the fundamental wave of laser light.