JP2875831B2 - Infrared light sensitive photographic material containing antihalation dye and / or acutance dye - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to photographic elements incorporating antihalation or acutance dyes.

BACKGROUND OF THE INVENTION Photosensitive recording materials can experience a phenomenon known as halation, which causes a deterioration in the quality of the recorded image. Such degradation can occur when a portion of the image forming light beam that falls on the photosensitive layer is not absorbed but penetrates to the film substrate on which the photosensitive layer is applied. A portion of the light reaching the substrate is retroreflected and can strike the photosensitive layer from below. That is, the reflected light may in some cases contribute significantly to the overall exposure of the photosensitive layer. The particulate matter in the photosensitive element is
Either can scatter light passing through this element. The scattered light reflected from the film substrate passes through the photosensitive layer a second time, exposing on the area adjacent to the intended exposure point. This effect leads to image degradation. Silver halide based photographic materials (including photothermal photographic materials)
Since the photosensitive layer contains light scattering particles,
It tends to cause this form of image degradation. The effect of light scattering on image quality is well documented, for example,
“The Theory of the Photographic Pr by THJames
ocess, "4th Edition, Chapter 20, Macmillan, 1977.

It is common practice to minimize this light scattering effect by including a light absorbing layer in the photographic element. The absorption of this layer must be effective at the same wavelength as the sensitivity of the photosensitive layer. If the imaging material is coated on a transparent substrate, the light absorbing layer will often It is coated on the side opposite to the conductive layer. Such a layer is known as an "antihalation layer" and effectively reduces any reflection of light that has passed through the photosensitive layer.

A similar effect can be obtained by a light absorbing layer inserted between the photosensitive layer and the substrate. This structure can be described as an "antihalation underlayer", and such an antihalation underlayer can be applied to a photosensitive coating on a transparent or non-transparent substrate. A light-absorbing substance may be incorporated in the photosensitive layer itself to absorb scattered light. The substance used for this purpose is known as "acutance dye". Image quality can also be improved by coating a light absorbing layer over the photosensitive layer of the photographic element.

Such coatings, as described in U.S. Pat. Nos. 4,312,941, 4,581,323 and 4,581,325, reduce the multiple reflections of scattered light within the interior surface of a photographic element.

A number of substances are known that absorb visible and / or ultraviolet light, of which 70
The goal is to improve the image in conventional photographic elements which are sensitive to wavelengths below 0 nm. In particular, triarylmethane dyes and oxonol dyes are exclusively used in this connection. However, there is a need for antihalation dyes and acutance dyes that absorb spectra in the near infrared region.

The use of semiconductor light sources to output image data stored electrically on photographic film or paper is becoming increasingly widespread. Because the output of these light sources is typically in the far-infrared or near-infrared region, there is an increasing demand for high quality imaging materials designed to expose in this region. This includes conventional wet processed silver halide photographic materials and dry heat treated materials such as "dry silver" films and paper.

In the ultraviolet photosensitive material and the visible part photosensitive material,
Organic dyes of the type commonly used for antihalation and / or acutance purposes do not readily form stable derivatives that absorb strongly in the near infrared. The term visible light used here means a wavelength of 400 to 700 nm,
And the term of near infrared light is 700-1400 nm, especially 750-1300
means nm wavelength.

Coatings of antihalation or acutance dyes that absorb in the visible region of the spectrum are usually treated during processing of the photographic material by washing or chemical reactions in wet processing techniques, or by thermal bleaching during heat treatment techniques. Need to be colorless.

Because the human eye is insensitive to the near infrared region,
Dye coatings that absorb only at wavelengths longer than 700 nm appear colorless and are therefore acceptable in the photographic material without any change in absorption during processing.
Dyes of this type are suitable as antihalation dyes and acutance dyes in infrared sensitive photographic elements. Heptamethine and long-chain cyanine dyes are known to have maximum absorption in the near infrared region of the spectrum. However, simple, near-infrared absorbing cyanine dyes are extended on the short wavelength side and exhibit absorption curves that extend well into the visible region of the spectrum [see, for example, A. Weissberger and ECTaylor. Special Topics in Heterocyclic Chemistry, John Wi
leyand Sons, 1977, p. 504]. This absorption curve, which extends to the visible, gives an undesirably strong, blue or green appearance that does not disappear during photographic processing.

U.S. Pat.No. 4,581,325 discloses a class of heptamethine, cyanine dyes having cyclopentene rings in the polymethine chain, which are suitable for use as antihalation or acutance dyes in both wet-processed and dry silver photographic materials. Are listed as such.

It is an object of the present invention to provide another dye that is capable of forming a coating that is absorbing in the near infrared and also has relatively low visible absorption.

SUMMARY OF THE INVENTION According to the present invention, one or more c
A photographic element having a silver logenide-based photosensitive layer,
As an acutance or antihalation dye,
Contains a compound having a nucleus represented by the general formula
A photographic element is provided that features:Wherein n is 1 or 2, R¹, R^Two, R^Five, And R⁶Is independently hydrogen, up to 30
Alkyl groups with up to 10 carbon atoms
Aryl groups having, and having up to 10 carbon atoms
Selected from aralkyl groups or a nitrogen atom
Required to complete a ring fused to a phenyl group
Child or R¹And R^TwoTogether with, and
(Or) R^FiveAnd R⁶Together with a 5 or 6 member
Can represent the atoms required to complete a heterocyclic ring.
This heterocyclic ring has a substituent or a fused carbocyclic ring.
Can be R^ThreeAnd R^FourIs independently hydrogen, tertiary
Amino groups, alkyl groups having up to 10 carbon atoms, 10
Aryl groups with up to 10 carbon atoms, up to 10 carbon atoms
Aralkyl groups having atoms, or C, N, O and S
From a heterocyclic group having up to 6 atoms selected from
Chosen and X Represents an anion].

As is well understood in the art, large-scale substitutions are not only tolerated, but are often recommended. To simplify the description and discussion of these groups, "group" and "moiety" are used to distinguish between chemical species that are allowed or can be substituted. . For example, the term "alkyl" refers to methyl, ethyl, cyclohexyl, isooctyl,
Not only are pure hydrocarbon alkyl chains such as tert-butyl, but also hydroxyl, alkoxy, halo (F, Cl,
Includes alkyl chains with substituents conventional in the art such as Br, I), cyano, nitro and the like. The term "alkyl moiety" is limited to those that include only pure hydrocarbon alkyl chains, such as methyl, ethyl, propyl, cyclohexyl, isooctyl, tert-butyl, and the like.

The polymethine dyes of the formula (I) are known and are described, for example, in J. Amer. Che by WSTuemmler and BSWildi.
Soc., 1958, 80 , p. 3772, Helv. Chem. Acta. 1945, 28 , p. 600 by H. Lorenz and R. Wizinger, U.S. Pat.
No. 938, No. 2,813,802, No. 3.099,630, No. 3,27
Nos. 5,442, 3,436,353 and 4,547,444, and JP 56-109358. These dyes find use in infrared screening compositions as photochromic substances, as sensitizers for photoconductors, and also as optical signal recording media. However, it has not been shown that the polymethine dyes of the formula (I) have properties suitable for use as antihalation dyes.

These dyes can be incorporated into a wet-processed photographic element or a dry-processed photothermographic element according to conventional techniques as an acutance dye. These dyes can also be incorporated into the antihalation layer according to conventional techniques, for example, as an antihalation backing layer, as an antihalation underlayer, or as an overcoat.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The dyes according to the present invention are preferably incorporated into the layers in amounts that provide a concentration of 0.05 to 2, most preferably 0.1 to 1.0, over the general wavelength range to which the photographic element is sensitive. The dye represented by the structural formula (I) is
It has been found that it has properties particularly suitable for the purpose of preventing halation for the following reasons. In most cases, these dyes have high absorption in the near infrared region and thus provide good antihalation protection. Significant of these dyes have low absorption in the visible region, and thus only exhibit low visible residual dyeing in photographic applications using heat treatment. Dyes of structural formula (I) are also unexpectedly bleached by conventional photographic developer compositions and are therefore suitable for antihalation purposes in conventional wet-processed silver halide photographic materials. In this case, even the slightest visible residual stain is bleached by the treatment solution, leaving a desirable colorless background.

The photothermographic medium can be selected from any of the known systems, such as, for example, the systems described in US Pat. Nos. 3,152,904 and 3,457,075. Preferred photothermographic media are dry silver systems containing a heat developable mixture of a photosensitive silver halide and a silver salt of an organic fatty acid, such as silver behenate, and a mild reducing agent. The components of the media can be coated as one or more layers. The components of the photothermographic medium and the components of the antihalation layer can, if desired, be maintained in a non-reactive combination by the presence of a barrier layer between the antihalation layer and the image forming layer.

In the dye represented by the formula (I), R ¹ , R ² , R ⁵ and
R ⁶ is preferably an alkyl group, more preferably an alkyl moiety having 1 to 5 carbon atoms. Preferably, R ¹ = R ² = R ⁵ = R ⁶ . However, R ¹ , R ² ,
R ⁵ and R ⁶ can be selected from a wide range of aryl, eg, phenyl, and aralkyl groups, as is known in the art. Alkyl, aryl and aralkyl groups are substituents of the type known in polymethine dyes, such as halogen, alkoxy, CN, OH,
It can have carboxyl and the like.

R ¹ , R ² , R ⁵ , and R ⁶ can also represent the atoms required to complete a ring fused to the phenyl group to which the nitrogen atom is attached. For example, R ¹ and R ² can complete a julolidine group.

R ³ and R ⁴ preferably represent an optionally substituted phenyl group, more preferably a group of the formula: Wherein R ⁷ is hydrogen, halogen, hydroxy, alkyl having 1 to 5 carbon atoms, alkoxy having 1 to 5 carbon atoms and —NR ⁹ R ¹⁰ (wherein R ⁹ and R ¹⁰ are Selected from the same groups as R ¹ and R ² ).

X ^- is a halogen ion eg Cl, Br; halogen-containing complex anions, e.g. tetrafluoroborate, hexafluorophosphate, RCOO ^- and RSO ₃ ^- (wherein R
Is an alkyl or aryl having up to 20 carbon atoms, and may be any suitable anion, including fluorinated, for example, CF ₃ COO ⁻ , CF ₃ SO ₃ ⁻ ) Can be.

The polymethine chains and phenyl groups present in formula (I) can have substituents of the type known in the art. The free bonds of the polymethine chain are preferably saturated with hydrogen. However, substituents such as hydroxy, alkyl, alkoxy, aryl and aryloxy groups may also be present on the polymethine chain,
These substituents may be substituted and generally have up to 8 carbon atoms. Polymethine chains may also be substituted with halogen atoms and CN groups.
Although chain displacement is generally not preferred, they are well known in the dye art.

A preferred group of compounds of formula (I) has the formula: Wherein R ¹ , R ² , R ⁵ , R ⁶ R ⁷ , n and X are as defined above, and R ⁸ has the same definition as R ⁷ .

Shows a specific example of formula (II) in the following table: Table Compound number ^{R 1 = R 2 R 5 =} R 6 R 7 = R 8 n X - 1 CH 3 CH 3 H 1 CF 3 SO 3 2 CH ₃ CH ₃ N (CH ₃ ) ₂ 1 CF ₃ SO ₃ 3 C ₂ H ₅ C ₂ H ₅ N (C ₂ H ₅ ) ₂ 1 CF ₃ SO ₃ 4 CH ₃ CH ₃ Cl 1 CF ₃ SO ₃ 5 CH _The present invention will now be described by way of the following examples. ₃ CH ₃ OCH ₃ 1 CF ₃ SO ₃ 6 CH ₃ CH ₃ N (CH ₃ ) ₂ 2 CF ₃ SO ₃

Example 1 Wetting agent (4.6 cm ³ , 10% Hostapur SAS, 93, this is Hoech
5% gelatin (200 g) containing
Adjust the pH of the aqueous solution to 4.5 and heat to 65 ° C. Dye (I) (0.25 g) is dissolved in methanol (25 cm ³ ) at 60 ° C. and added to the aqueous gelatin solution with stirring. The mixture
Cool to 50 ° C. and add the curing agent (8 cm ³ , 2% formaldehyde). This solution is applied on a polyethylene terephthalate substrate at 66 cm ³ / m ² . This coating is 8
It exhibited an optical absorption of 0.5 at 15 nm and a pale pink visible coloration. On the opposite side of the substrate, an infrared sensitive silver halide coating is applied. The photographic element thus formed is exposed to a resolution test pattern using a laser diode scanning device emitting infrared light at 815 nm. This material is processed under standard conditions in an automatic X-ray film processor using a Kodak RP X-O matte processor. The processed film showed a sharp image on a colorless background.

A similar material prepared without an antihalation backing produced a dirty image under the same test conditions.

Example 2 Polymethine dye (1) (0.085 g) is dissolved in a mixture of N-methylpyrrolidone (8.7 g) and methanol (6.7 g). To this solution was added toluene (20.9 g) and butane-2-
Cellulose acetate butyrate (6.2 g) and PE200 polyester resin (0.8 g) in a mixture with ON (43 g)
Add the solution. A solution of methyl isobutyl ketone (7.0 g) in methanol (7.0 g) is also added. This final solution is coated on a polyethylene terephthalate substrate with a wet thickness of 60 microns, dried at 80 ° C for 4 minutes, and dried at 780 nm.
An optical density of 0.4 was obtained.

On the opposite side of the substrate is coated a dry silver photothermographic structure. The photothermographic element thus formed is exposed to a test pattern of near infrared radiation (780 nm). This material is at 127 ° C for 6 seconds,
Treat by heating. A sharp image was produced on a slightly magenta colored background. A similar coating is formed using a bluish polyester substrate of the type used for medical X-ray films. In this case, no residual staining was found.

Coatings without an antihalation backing produced for comparison produced a dirty image under the same test conditions.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nicholas Eugenuts Glzeskowiack Harlow, The Pinnacles, England (no address) Minnesota 3M Research Limited Care (56) References JP-A-63-19651 (JP, A) JP-A-56-109358 (JP, A) JP-A-59-182436 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03C 1/83 G03C 1/498

Claims (18)

(57) [Claims] 1. A photographic element having one or more silver halide-based light-sensitive layers on a substrate, which comprises, as an acutance dye or an antihalation dye, a compound of the general formula (I): Wherein n is 1 or 2, R ¹ , R ² , R ⁵ and R ⁶ are independently hydrogen, an alkyl group having up to 30 carbon atoms, up to 10 carbon atoms Is a member selected from the group consisting of an aryl group having an aralkyl group having up to 10 carbon atoms, or an atom required to complete a ring condensed with a phenyl group to which a nitrogen atom is bonded Or R ¹ and R ² together and / or R ⁵ and R ⁶ together represent the atoms required to complete a 5- or 6-membered heterocyclic ring The heterocyclic ring may have a substituent or a fused carbocyclic ring, and R ³ and ⁴ are independently hydrogen, a tertiary amino group, up to 10 carbon atoms. Alkyl groups, aryl groups with up to 10 carbon atoms, aralkyl with up to 10 carbon atoms A member selected from the group consisting of heterocyclic groups having Le group and C, N, atoms of O and S up to six selected, and X ^- is a compound having a nucleus represented by an anion] A photographic element comprising: 2. A photographic element according to claim ¹ , wherein R ¹ , R ² , R ⁵ , and R ⁶ each represent an alkyl moiety having 1 to 5 carbon atoms. 3. The photographic element according to claim 1, wherein R ³ and R ⁴ are an optionally substituted phenyl group. 4. A method according to claim 1, wherein R ³ and R ⁴ are of the formula Wherein R ⁷ is a halogen, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms and —NR ⁹ R ¹⁰ (wherein R ⁹ and R ¹⁰ are the same or different Which has the same definition as R ¹ and R ^{2 according} to claim 1) and is a member selected from the group consisting of: 5. The method according to claim 1, wherein the dye has the formula Wherein R ¹ , R ² , R ⁵ , R ⁶ , n and X are as defined in claim 1 and R ⁷ and R ⁸ are independently halogen, carbon atom 1 to An alkyl group having five,
An alkoxy group having 1 to 5 carbon atoms and -NR ⁹ R ¹⁰
Wherein R ⁹ and R ¹⁰ are independently members selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 5 carbon atoms. A photographic element according to claim 1. 6. A photographic element according to claim 1, wherein said dye is present in the layer such that an optical density of 0.05 to 2.0 is imparted to the layer. 7. A photographic element according to claim 1, wherein said dye is present in the layer such that an optical density of 0.1 to 1.0 is imparted to the layer. 8. A photographic element according to claim 1, wherein said photographic element is a conventional wet-processed photographic element. 9. A photographic element according to claim 1 or claim 5, wherein said photographic element is a photothermographic element containing a photosensitive silver halide in combination with a silver salt of an organic acid. 10. The photographic element of claim 1, wherein said dye is present in an antihalation backing on said substrate. 11. A photographic element according to claim 5, wherein said dye is present in an antihalation backing on said substrate. 12. The photographic element according to claim 1, wherein said dye is present as an underlayer between said substrate and said one or more photosensitive layers. 13. A photographic element according to claim 5, wherein said dye is present as an underlayer between said substrate and said one or more photosensitive layers. 14. A photographic element according to claim 1, wherein said dye is present in an overcoat over a photosensitive layer. 15. The photographic element according to claim 5, wherein said dye is present in an overcoat over the photosensitive layer. 16. A photographic element according to claim 1, wherein said dye is present in a photosensitive layer. 17. The photographic element according to claim 5, wherein said dye is present in a photosensitive layer. 18. The photographic element according to claim 1, wherein said one or more photosensitive layers is infrared sensitive.