JPH0675326A - Halogenated silver photograph material with resistance improved for pressure desensitization - Google Patents

Abstract

PURPOSE: To obtain the improved resistance against pressure desensitization by incorporating respectively polyhydroxy benzene in a silver halide emulsion and a wax-like polyolefin particle in a hydrophilic layer of the outermost side. CONSTITUTION: A photosensitive silver halide photographic material having a supporting body and one or more hydrophilic layers applied thereon, at least one layer of which contains the silver halide emulsion high in chloride content, and for obtaining a white and black half tone dot or line image is provided and the polyhydroxy benzene expressed by a formula is incorporated in the silver halide emulsion and the wax-like polyolefin particle having 0.5-3μm particle diameter is incorporated in the hydrophilic layer of the outermost layer applied on the surface of the same side as the silver halide emulsion layer on the supporting body. In the formula, (n) represents 1, 2 or 3, R represents a halogen, an alkyl, an alkoxy, an amino, an amide, a sulfoamide, a carboxy or the like and P represents 0, 1 or 2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a photosensitive silver halide material for obtaining black and white half-tone dot or line images which has improved resistance to pressure desensitization.

[0002]

BACKGROUND OF THE INVENTION Photosensitive silver halide materials are commonly used in the photolithographic industry for obtaining halftone, dot or line high contrast images. One example of a high contrast photographic element with a white reflective support is a phototypesetting material intended to produce a black type image on a white background. One example of a high contrast photographic element with a transparent support is a lith film (so called because it is used as a contact transparency for exposing lithographic printing plates). The illusion that a region of the printed image is of medium density occurs because the viewer cannot distinguish between the highest density fine dots or lines and the lowest density background regions that separate them. Such an image is called a halftone image.

It is known in the silver halide photographic art that unevenly applied pressure results in local differences in the image density of photographic film. This is a practically undesirable effect and is known as pressure or kink sensitivity.
This effect causes a portion of the light-sensitive silver halide photographic material to appear black or white by sensitization or desensitization. In some cases the concentration produced by silver halide grains is increased, but more usually silver halide grains are desensitized. Pressure sensitization or desensitization occurs during handling of the photographic material (i.e. folding, twisting and / or bending) or during the shipping process. Pressure desensitization is most often seen in large format photographic elements which are more sensitive to twist.

The pressure sensitivity of silver halide photographic materials can be determined, for example, by Research Disclosure.
Volume 176 (December 1978), Item 1764, Sections VI, K; Research Disclosure Volume 184 (August 1979), Item 18431,
Section II, H; Research Disclosure Vol. 308 (1989
December), Sections 308,119, Sections VI, KL; and EJ Beer (B
irr) "Stabilization of silver halide emulsions (Stabilizat
ion of Silver Halide Emulsion) ", Focal Press
(Focal Press), London, 1974, pages 133-134, can be reduced by the addition of various additives. Research Disclosure is Kenneth Mason Publications Lt.
d.), Emsworth, Hampshir
e), PO10, 7DD, England. However, some of these additives often do not have a substantial effect on pressure sensitivity and adversely affect photographic properties.

The addition of substituted or unsubstituted polyhydroxybenzenes in silver halide photographic materials to reduce pressure sensitivity is described in EP 209,010, in which polyhydroxybenzenes and aryl hydrazides are combined. A negative photographic material containing high contrast and reduced pressure sensitivity is claimed. Also, US No.
No. 4,914,002 claims a silver halide having excellent pressure characteristics containing a combination of hydrazine, cyanine and dihydroxybenzene which has no maximum absorption in the visible light region.

However, the use of polyhydroxybenzenes to reduce pressure sensitivity can degrade the anti-blocking properties due to the large amount of the compound required, especially as it increases the tendency of emulsion stickiness. Limited in terms of gain.

Therefore, there is still a need for silver halides that reduces all the above problems.

It is known in the art to protect photographic materials from mechanical damage by coating a gelatin surface protective thin layer. It is also known to include a lubricant, such as a water insoluble wax, in the protective layer to reduce the formation of scratch marks. The water-insoluble wax for that purpose can be any of the six known waxes: vegetable wax, petroleum wax, insect wax, animal wax, mineral wax, and synthetic wax. Waxes are also used for a variety of purposes other than protective layers.

GB 1,519,864 describes a photographic material having an antistatic backing material containing a polymeric electrolyte as an antistatic agent and dispersed polyolefin particles smaller than 0.5 μm as a slip agent.

US Pat. No. 2,726,955 describes anti-pluming agents.
A photographic material having a silver halide emulsion layer containing rigid particles of wax containing an anti-plumming agent is described.

US Pat. No. 3,676,142 describes a photographic element having a hydrophilic colloid and a continuous phase having a dispersed phase containing color couplers dispersed in water-insoluble wax particles.

US Pat. No. 4,766,059 describes a photographic element having a protective hydrophilic colloid layer containing a silver halide emulsion layer and fine spherical beads having an average particle size in the range 0.5 to 20 μm, the beads being Photographic materials are described that contain a hydrophobic polymeric material and a water-insoluble wax dispersed in the polymeric material. This combination reduces stickiness and scratching formation in stacked photographic elements.

Research Disclosure 16743 (March 1978) describes a photosensitive silver halide photographic material coated on polyolefin laminated paper or synthetic paper and containing oil droplets of an organic water-insoluble compound in a silver halide emulsion layer. Is listed. The particle size of oil droplets is 1.5 to 10 times the average particle size of silver halide. About 50 ℃ for organic high boiling compounds
Or has a melting point below that. Examples of such compounds include paraffin. When such oil droplets are contained in the photosensitive silver halide emulsion layer, pressure fog prevention is achieved, but even if such oil droplets are added to the non-photosensitive layer (for example, a protective layer), There is no advantage like.

[0014]

SUMMARY OF THE INVENTION The present invention comprises a support and one or more hydrophilic layers coated thereon, at least one of which is a silver halide emulsion having a high chloride content. A photosensitive silver halide photographic material for obtaining a black and white halftone dot or line image having:

[0015]

[Chemical 4]

Wherein n is 1, 2 or 3, R is hydrogen, halogen, alkyl, alkoxy, amino, amido, sulfonamide, carboxy, etc., and p is 0, 1 or 2. ] And the outermost hydrophilic layer coated on the same side of the support as the silver halide emulsion layer is 0.
It relates to a silver halide photographic material characterized in that it contains wax-like polyolefin particles having an average particle size in the range of 5 to 3 μm.

Another aspect of the present invention is a support and one or more hydrophilic layers coated thereon, at least one of which is a silver halide emulsion having a high chloride content. A silver halide photographic material having and containing a method for obtaining a halftone dot or line image that is subjected to a photographic process involving imagewise exposure to form an image and alkali solution development. Therefore, the silver halide emulsion with high chloride content of the above photographic material is

[0018]

[Chemical 5]

Wherein n is 1, 2 or 3, R is hydrogen, halogen, alkyl, alkoxy, amino, amido, sulfonamide, carboxy, etc., and p is 0, 1 or 2. ] And the outermost hydrophilic layer coated on the same side of the support as the silver halide emulsion layer is 0.
It relates to a method characterized in that it comprises wax-like polyolefin particles having an average particle size in the range from 5 to 3 μm.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a support and one or more hydrophilic layers coated thereon, at least one of which is a silver halide emulsion having a high chloride content. A photosensitive silver halide photographic material for obtaining a black and white halftone dot or line image having:

[0021]

[Chemical 6]

Wherein n is 1, 2 or 3, R is hydrogen, halogen, alkyl, alkoxy, amino, amido, sulfonamide, carboxy, etc., and p is 0, 1 or 2. ] And the outermost hydrophilic layer coated on the same side of the support as the silver halide emulsion layer is 0.
It relates to a silver halide photographic material characterized in that it contains wax-like polyolefin particles having an average particle size in the range of 5 to 3 μm.

The polyhydroxybenzene according to formula (I) above may be a dihydroxybenzene compound, a trihydroxybenzene compound or a tetrahydroxybenzene compound. Useful examples of dihydroxybenzene compounds are 1,2-
Dihydroxybenzene, ie pyrocatechol, 1,3-
Dihydroxybenzene, ie resorcinol, 1,4-
It is dihydroxybenzene, or hydroquinone. Useful examples of trihydroxybenzene compounds are 1,2,3-
Trihydroxybenzene, namely pyrogallol, 1,3,
5-trihydroxybenzene, ie phloroglucinol, 1,2,4-trihydroxybenzene, ie hydroxyhydroquinone. Useful examples of the tetrahydroxybenzene compound are 1,2,3,4-tetrahydroxybenzene, 1,2,4,5-tetrahydroxybenzene and 1,3,4,5-tetrahydroxybenzene.

The polyhydroxybenzenes are unsubstituted or, for example, halogen, alkyl, alkoxy, amino,
It can be substituted with amides, sulfonamides, carboxy and the like. Unsubstituted polyhydroxybenzene is preferred.

Polyhydroxybenzene (PHB) is used in a photographic emulsion containing a photosensitive silver halide grain and a carrier medium or a binder in an amount of 0.01 to 0.1 per mol of silver.
Mole PHB, preferably 0.03 to 0.07 mole PHB per mole silver
Added in quantity.

The wax can be natural or synthetic and of petroleum, mineral, vegetable or animal origin. Waxes are usually water insoluble, smooth and shiny, are relatively hard solids at room temperature and can melt on warming. The waxes used in the present invention are synthetic polyolefin waxes such as polyethylene, polypropylene, polytrifluoroethylene and their copolymers. They are produced by polymerizing alkene monomers and are in the range 2000-6000, preferably 20
They have the properties of high molecular weight hydrocarbon waxes when they have a molecular weight in the range of 00 to 4000. The preparation and properties of polyolefin waxes are well known, for example Alvin.
Alvin H. Warth, "Wax Chemistry and Technology (Th
e Chemistry and Technology of Waxes), 2nd edition, 443
Below page, Reinhold Publishing C
o.) ", and" Polymer Science and Technology Encyclopedia, No. 14
Volume, 768 pages or less, Intersci Publisher
encePublishers) ”. Wax-like type polyolefins are marketed as finely divided powders that do not tend to agglomerate despite their fine particle size and can be dispersed in an aqueous composition by a low speed mixer without the need for high shear conditions or melting. Wax-like type polyolefins are also marketed in the form of dispersions of finely divided particles in aqueous or water-miscible solvent compositions which are easily incorporated into aqueous gelatin compositions by slow stirring. By using the polyolefin dispersion according to the present invention, the producer can omit chlorinated hydrocarbons used as a solvent for dispersion waxes other than polyolefin waxes.
The polyolefin dispersion used in the present invention is about 0.5 μm.
Contains particles having an average particle size of about 3 μm. These polyolefin dispersions formed by dispersing polyolefins already in solid form produce particles that are substantially larger than those obtained directly by the polymerization of olefins in the presence of a catalyst and dispersant in the aqueous phase. Including. polyethylene,
Polypropylene, polytrifluoroethylene dispersion,
And dispersions of the corresponding copolymers have been found to be particularly suitable in the present invention.

The above polyolefins are usually added as an aqueous dispersion in the presence of a suitable dispersant, preferably a nonionic dispersant, in a carrier medium or binder forming the outermost side of the film. Aqueous dispersions containing 35% by weight of polyolefin are preferred, but dispersions containing 1 to 50% by weight of polymer are also suitable.

Suitable dispersants are usually alkylphenyl polyethylene glycol ethers such as nonylphenyl polyethylene glycol ether and undecylphenyl polyethylene glycol ether; alkyl and aralkyl polyether alcohols such as isooctylphenyl polyethoxyethanol, nonylphenyl polyethoxyethanol. , And nonionics such as tetradecylphenyl polyethoxy ethanol. Other suitable dispersants are saponins and hexitol ring dehydration product oxyalkylene ethers, such as polyoxyethylene sorbitan monolaurates, monostearates and monooleates containing 2-20 oxyethylene groups divided into three chains; alkyls. Substituted aryloxyalkylene ether sulfonates such as sodium pt-octylphenoxyethoxyethyl sulfonate; sodium dodecyl, tetradecyl and octadecyl sulphate, and dioctyl esters of sodium sulfosuccinate. Certain soaps such as morpholine oleate and sodium stearate can also be used.
The dispersant is 1 to 50% by weight of the polyolefin, preferably 2
Used in an amount of ~ 20% by weight.

The polyolefin can be used in any concentration that is effective for its intended purpose. Suitable densities are 0.01 to 0.1, preferably 0.02 to 0.08 grams per square meter of photographic material.

As the vehicle or binder for the hydrophilic layer of the photographic material of the present invention, any hydrophilic binder known in the art can be used. Suitable binders include natural polymers, synthetic resins, polymers and copolymers, and other film forming media. Binders range from thermoplastic to highly crosslinked and are coated from aqueous solutions or organic solvents or emulsions.

Gelatin is the preferred hydrophilic colloid used in the present invention. However, other water-soluble colloidal substances or mixtures thereof can also be used. Typical hydrophilic colloidal substances include gelatin derivatives such as phthalated gelatin and acetylated gelatin, cellulose derivatives such as carboxymethyl cellulose, synthetic hydrophilic colloids such as starch, casein, zein, polyvinyl alcohol and polyvinylpyrrolidone. , Copolymers such as acrylic acid esters, acrylonitrile and acrylamide, and the like.

The actual amount of hydrophilic binder used depends on the amount of dispersing solvent and the required coating thickness. An excess of binder can reduce maximum density and contrast, so
For the purposes of this invention the binder is 250 grams per mole of silver halide, preferably 20 to 2 per mole of silver halide.
Advantageously used in an amount of 00 grams.

The silver halide emulsions used in the present invention are preferably monodisperse, but emulsions with a broad particle size distribution are also used. The term "monodisperse" refers to an emulsion having a coefficient of variation of less than 45%, preferably less than 35%, more preferably less than 20%. Emulsions suitable for the present invention are of the type originally used to obtain halftone dot or line images and are commonly referred to as lith emulsions. The squirrel emulsion preferably comprises at least 50 mol% silver chloride, more preferably at least 80% silver chloride and at least about 5% silver bromide. If desired, the silver halide grains can contain small amounts of silver iodide, usually less than about 5 mol%, and preferably less than 1 mol%. Another reference for lithographic materials is Research Disclosure, Vol. 235 (November 1983), Item 23510, Development nucleation with hydrazine and hydrazine derivatives.
Nucleation by Hydrazine and Hydrazine derivative
s) ”. The silver halide average grain size is less than about 0.7 μm, preferably less than about 0.4 μm, and more preferably less than 0.2 μm. "Grain size"
The term refers to the diameter of a circle having the same area as the average area projected by a silver halide crystal when viewed under an electron microscope. The silver halide grains are those having a regular crystal form such as cubes or octahedra, or those having an irregular crystal form such as spheres or plates, or those having a composite crystal form. They may consist of a mixture of grains having different crystal forms.

Silver halide emulsions are sulfur sensitizers such as allylthiocarbamide, thiourea, cysteine;
Active or inactive selenium sensitizers; reduction sensitizers such as tin (II) salts and polyamines; gold sensitizers, etc., more particularly gold (III) calcium thiocyanate, gold (I) calcium chloride, chloride Noble metal sensitizers such as calcium platinate; or eg ruthenium, rhodium, iridium, palladium etc.,
More particularly ammonium chloride
It is chemically sensitized with a water-soluble salt such as chloropalladate) or sodium chloropalladate, and each of such sensitizers is used alone or in an appropriate combination.

Further, the silver halide emulsion is not only photosensitive to blue light but also sensitive to, for example, green light (orthophotosensitive or
tho-sensitive) or green and red light exposure (pan exposure)
(pan-sensitive) to spectrally sensitize. For that purpose, for example, trinuclear or higher-nucleus methine dyes such as rhodacyanine or neocyanine, as well as acidic or basic cyanines, hemicyanines,
Conventional monomethine or polymethine dyes such as streptocyanines, merocyanines, oxonol, hemioxonol, styryl dyes and the like can be used. Sensitizers of this kind are described, for example, by FM Hamer in "The Cyanine Dyes and Related Compounds".
Related Compounds) ", InterScience Publisher (Int
erscience Publishers, John Wiley and Sons, New Yor
k) 1964, and Research Disclosure No. 308
Vol., December 1989, Item 308119, "Photographic silver halide emulsions, preparations, additives, processes and systems (Photo
graphic Silver Halide Emulsion, Preparation, Adden
da, Processing and System) ”, Section 4.

Chemical and spectral sensitization is not absolutely necessary and, if done, should not adversely affect the high contrast values.

The silver halide emulsion can be prepared by a single jet method, a double jet method, or a combination of these methods, or can be aged using, for example, an ammonia method, a neutralization method, an acid method or the like. At the end of grain precipitation, water-soluble salts are removed from the emulsion by processes known in the art such as ultrafiltration. Emulsions include brighteners, antifoggants and stabilizers, filters and antihalo dyes, hardeners, coating aids,
Plasticizers, and for example Research Disclosure 1764
3, V, VI, VIII, X, XI, XII, other auxiliary substances such as those described in December 1978. The above emulsions are Research Disclosure 17643, XV and XVI
Various methods, such as those described in I, December 1978, can be used to coat several support substrates.

Examples of the support include poly-α-olefin (such as polyethylene and polystyrene), polyester (such as polyethylene terephthalate), cellulose ester (such as cellulose triacetate), paper, synthetic paper and resin-coated paper.

The emulsions also include various additives conveniently used for the purpose. These additives include stabilizers or antifogging agents such as azaindene, triazole, tetrazole, imidazolium salts, polyhydroxy compounds, etc .; aldehydes, aziridine, isoxazole, vinyl sulfone, acryloyl,
Includes film hardeners such as triazine type; development accelerators such as benzyl alcohol, polyoxyethylene type compounds; image stabilizers such as chroman, coumaran, bisphenol type. In addition, coating aids, permeability modifiers for processing liquids, antifoaming agents, antistatic agents, and matting
A matting agent is used. References for the types and uses of these additives are Research Disclosure No. 30.
8 Rings, December 1989, Item 308119 "Photographic Silver Halides, Preparations, Additives, Processing and Systems (Photographic Silver
Halide Emulsions, Preparation, Addenda, Processin
g and System) ”.

The photographic material of the present invention can contain a hydrazine derivative in order to obtain a high contrast image. For example, Research Disclosure Vol. 235, 1983 11
Moon, Item 23510, "Development Nucleation by Hydrazin Derivatives
e and Hydrazine Derivatives) ”can be used.

In another aspect of the present invention, a support and one or more hydrophilic layers coated thereon, at least one of which is a silver halide emulsion having a high chloride content. A silver halide photographic material having and containing a method for obtaining a halftone dot or line image that is subjected to a photographic process involving imagewise exposure to form an image and alkali solution development. Therefore, a silver halide emulsion having a high chloride content in the photographic material has the formula

[0042]

[Chemical 7]

Wherein n is 1, 2 or 3, R is hydrogen, halogen, alkyl, alkoxy, amino, amido, sulfonamide, carboxy, etc., and p is 0, 1 or 2. ] And the outermost hydrophilic layer coated on the same side of the support as the silver halide emulsion layer is 0.
It relates to a method characterized in that it comprises wax-like polyolefin particles having an average particle size in the range from 5 to 3 μm.

The present invention does not impose any special restriction on the developing process of the light-sensitive material. In general, any of the development steps used to process conventional photographic materials used in the lithographic field, including development, fixing and corrosion steps, can be used. Such a developing step is carried out manually or by using an automatic processor, generally in the range of 18 to 50 ° C., but can be carried out outside this range if necessary.

The developer may contain any known developer. Examples of developers (which may be used alone or in a mixture) are dihydroxybenzene (e.g. hydroquinone), aminophenol (e.g. N-methyl-p-aminophenol), 3
-Pyrazolidone (eg 1-phenyl-3-pyrazolidone), ascorbic acid and the like. Further, such a developer contains a preservative, an alkali agent, a buffering agent, an antifogging agent, a water softening agent, a curing agent and the like. Suitable developers for use with the photographic materials of the present invention include dihydroxybenzene developers, alkaline agents, small amounts of free sulfite to monitor free sulfite concentration and buffers for sulfite ions.
A so-called lith developer containing (formalin and sodium bisulfite addition compound, and acetone and sodium bisulfite addition compound).

The fixer solution can have any conventional composition. Examples of fixing agents that can be used are thiosulfate,
Included are thiocyanates and sulfur organic compounds known as fixatives. The fixer may further contain a water-soluble aluminum salt as a curing agent. The etchant can also have any conventional composition, for example by CEK Mees, "The Theory of the Photographic Process.
Photographic Process) '', McMillan, 1954
, Pp. 737-744, and more precisely as reducing agents, permanganate, iron (III) salts, peroxosulfates, copper (II) salts, selenate, hexacyanoiron (III) or dicyano. An etchant containing chromates, alone or in combination, and containing inorganic acids such as sulfuric acid, and alcohols can be used; or reducing agents such as hexacyanoiron (III) salts, ethylenediaminotetraacetatoiron () salts. Etching solutions including and silver halide solvents such as thiosulfates, thiocyanates, thioureas or their derivatives, and inorganic acids such as sulfuric acid can be used. Representative examples of the etching solution are a solution of Farmer containing potassium ferrocyanyanate and sodium thiosulfate, an etching solution containing persulfate, an etching solution containing selenate, and the like.

[0047]

The present invention will be described in more detail by the following examples.

[0048]

Example 1 Cubic monodisperse 0.32 μm silver chlorobromide (40 mole percent bromide) was prepared as follows. A solution (A) consisting of 4.700 liters of water, 0.9 g of adenine and 84 g of gelatin was initially introduced into the reaction vessel. The ingredients used to produce the silver halide grains were a solution of 5.379 liters of water and 2380 g of silver nitrate (B) and 5.281 liters of water, 6
It was a solution (C) of 88 g of KCl, 733 g of KBr and 0.002 g of Na ₃ RhCl ₆ .18H ₂ O.

Step 1- Pass the nucleation solutions (B) and (C) through two separate inlets, keeping the pAg of the contents in the vessel at 8.3 and the volume in the vessel from 4764 ml to 56.
The temperature was increased to 82 ml, and the mixture was simultaneously introduced into the reaction vessel at a flow rate of 51.0 ml / min for 9 minutes while vigorously stirring while maintaining the temperature at 56 ° C.

Step 2-First washing and concentration 9 minutes after the start of sedimentation, the addition of solutions (B) and (C) was stopped and the reaction was carried out to reduce the volume of the contents in the reaction vessel from 5682 ml to 2082 ml. The contents of the vessel were refluxed for 3 minutes through an ultrafiltration module, type PTHK000C5 (commercially available from Millipore Co., USA, fitted with a polysulfone semipermeable membrane having an NMWL (apparent molecular weight limit) of 100,000). The aqueous potassium nitrate solution formed as a by-product through the membrane during the precipitation of silver chlorobromide grains was drained, while the filtered silver halide dispersion was returned to the reaction vessel.

Step 3- Twelve minutes after the beginning of the growth , the addition of the solutions (B) and (C) into the reaction vessel was started for 25 minutes at a flow rate of 72.0 ml / min, and the volume of the contents was adjusted to 20 minutes.
Increased from 82 ml to 5682 ml.

Step 4-Second Wash and Concentration Repeat Step 2 to load the contents of the reaction vessel from 5682 to 32
Reduced to 88 ml.

Step 5-40 minutes after the beginning of growth , the addition of solutions (B) and (C) was continued for 7 minutes at 171 m.
Restart at a flow rate of l / min and reduce the volume of contents in the reaction vessel to 328
Increased from 8 to 5682 ml.

Step 6-Third wash and concentration Step 4 was repeated.

Step 7-Growth 50 minutes from the beginning, step 5 was repeated.

Step 8-Fourth wash and concentration Step 4 was repeated.

Step 9-Growth 65 minutes from the beginning, step 5 was repeated.

Step 10-5. Washing and Concentration Solutions (B) and (C) were completely added, and then the emulsion was mixed with 40
It was cooled to ℃ and washed by ultrafiltration until the conductivity reached 9,000 μS.

Gelatin (1050 g) was added to the contents in the reaction vessel with stirring at 45 ° C. until the gelatin dissolved.

The resulting emulsion was sensitized with gold and sulfur, optically sensitized at 630 nm, divided into 14 parts, and hydroquinone was added to each part as shown in Table 1 to obtain a silver coverage of 4.0 g / m ^2. On a polyethylene terephthalate support. A coating composition of aqueous gelatin containing a polyolefin wax as shown in Table 1 was used to obtain a gelatin coverage of 0.70.
It was coated on the emulsion layer as a gelatin protective layer at g / m ² .

[0061]

[Table 1] Coatings Hydroquinone Polyolefin wax g / m ² M / M Ag A---B 0.05--C-Lancoglide CE 0.05 D 0.05 Lancoglide CE 0.05 E-Lancoglide ET 0.05 F 0.05 Lancoglide ET 0.05 G-Lancoglide TFW 0.05 H 0.05 Lancoglide TFW 0.05 I-Lancoglide PME 0.05 L 0.05 Lancoglide PME 0.05 M-Lancoglide PMW 0.05 N 0.05 Lancoglide PMW 0.05 O-Lancoglide PPW 0.05 P 0.05 Lancoglide PPW 0.05

Lancoglidd ^™ CE is the average particle size
It is a dispersion of polyethylene in ethanol with 1.3 μm and is the trade name of Ritterhude-Ihlpohl, Langer & Co., Germany.

Lancoglide ^™ ET is a dispersion of polyethylene in ethanol having an average particle size of 1.2 μm and is the trade name of Ritterhude-Ehlpol, Langer GmbH, Germany.

Lancoglide ^™ TFW is a dispersion in water of a polyethylene / polytrifluoroethylene copolymer having an average particle size of 2.5 μm and is the trade name of Ritterhude-Ehlpol, Langer GmbH, Germany.

Lancoglide ^™ PME is a dispersion of polyethylene / polytrifluoroethylene copolymer in ethanol having an average particle size of 1.5 μm, manufactured by Langer GmbH of Germany,
It is a product name of Littelfude-Eel Paul.

Lancoglide ^™ PMW is a dispersion in water of a polyethylene / polytrifluoroethylene copolymer having a mean particle size of 1.5 μm and is the trade name of the German company Langer GmbH, Ritterhude-Ehlpol.

Lancoglid ^™ PPW is a dispersion in water of polypropylene having an average particle size of 1.5 μm and is the trade name of Ritterhude-Ehlpol, Langer GmbH, Germany.

The above polyolefin dispersion was added with stirring to the aqueous gelatin coating composition used to form the protective gelatin layer prior to coating.

Coatings A-O were subjected to a pressure sensitivity test in which a diamond needle with variable weight loading properties was moved along the surface of the untreated film. The coating was then treated with 3M RDC Lith developer and evaluated by measuring the minimum weight required to produce a visible line. The samples were evaluated according to the following classifications.

[0070]

The results are summarized in Table 2 below.

[Table 2]

[0072]

Example 2 A cubic monodisperse silver chlorobromide emulsion was prepared as described in Example 1 above, chemically and spectrally sensitized and divided into 5 parts, each part as shown in Table 3. Hydroquinone was added to the above to coat a polyethylene terephthalate support with a silver coverage of 4.0 g / m ² .
Using the coating composition of aqueous gelatin containing polyolefin as shown in Table 3 as a gelatin protective layer, the gelatin coverage
0.70 g / m ² was coated on the emulsion layer.

[0073]

[Table 3] Coatings Hydroquinone Polyolefin g / m ² M / M Ag Wax Q-Lanco TF 1780 0.025 R-Lanco TF 1780 0.05 S-Lanco TF 1780 0.075 T 0.05 Lanco TF 1780 0.05 U 0.05--

Lanco ^™ TF1780 has an average particle size of 2.5 μm
Is a finely divided synthetic polyolefin wax in the form of a powder of a polyethylene / polytrifluoroethylene copolymer, which is a trade name of Ritterhude-Ehlpol, Langer Co., Germany.

Lanco ^™ TF 1780 Tergitol ^™ 4 as a dispersant (anionic surfactant, Union Carbide
Co.), USA, trade name) and dispersed in a 5% aqueous solution of gelatin with a homogenizer and the dispersion was added to the gelatin coating composition before coating.

Coatings QU were subjected to a pressure sensitivity test as described in Example 1 above.

The results are summarized in Table 4 below.

[Table 4]

Other commercially available wax-like materials for dispersion in aqueous gelatin such as carnauba wax (vegetable wax), beeswax (insect wax) ceresin (mineral wax) are dissolved in trichlorethylene. And is emulsified in an aqueous gelatin solution with the help of a high speed mixer (Silverson ^™ homogenizer) in the presence of Tergitol ^™ . This means that harmful chlorinated hydrocarbons are used during the production of the wax dispersion and this solvent must be removed before adding the dispersion to the coating composition. The polyolefin wax-like compound according to the invention allows the producer to dispense with this harmful solvent.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Rosera Salvo Italy 17016 Ferrania (Savona) (No address displayed) 3M Italia Richelche Societa Pell Achioni

Claims (10)

[Claims] 1. A support and one or more hydrophilic layers coated thereon, at least one of the hydrophilic layers containing a silver halide emulsion having a high chloride content. Is a light-sensitive silver halide photographic material for obtaining black and white halftone dots or line images having the formula: [Wherein n is 1, 2 or 3, R is hydrogen, halogen, alkyl, alkoxy, amino, amide, sulfonamide, carboxy, etc., and p is 0, 1 or 2. ] Containing polyhydroxybenzene,
And, the outermost hydrophilic layer coated on the same side as the silver halide emulsion layer of the support contains wax-like polyolefin particles having an average particle size in the range of 0.5 to 3 μm. Silver halide photographic material. 2. A light-sensitive silver halide photographic material according to claim 1, wherein said high chloride content silver halide emulsion contains at least 50 mol% of silver chloride. 3. A light-sensitive silver halide photographic material according to claim 1, wherein said silver halide emulsion having a high chloride content contains at least 80 mol% of silver chloride. 4. A light-sensitive silver halide photographic material according to claim 1 wherein said high chloride chloride silver halide emulsion contains at least 5 mol% silver bromide. 5. The polyhydroxybenzene has the formula: The light-sensitive silver halide photographic material according to claim 1, which has the structure shown below. 6. A light-sensitive silver halide photographic material according to claim 1, wherein said polyhydroxybenzene is added to said silver halide emulsion in an amount ranging from 0.01 to 0.1 mol per mol of silver. 7. The polyolefin particles are 0.01 to 0.1 g
The light-sensitive silver halide photographic material according to claim 1, which is added in an amount of / m ² . 8. The polyolefin is polyethylene,
A light-sensitive silver halide photographic material according to claim 1 selected from the group consisting of polypropylene, polytrifluoroethylene and copolymers thereof. 9. A light-sensitive silver halide photographic material according to claim 1, wherein said polyolefin has a weight average molecular weight in the range of 2,000 to 6,000. 10. A support and one or more hydrophilic layers coated thereon, wherein at least one of the hydrophilic layers contains a silver halide emulsion having a high chloride content, A method for obtaining a halftone dot or line image which is subjected to a photographic process involving imagewise exposure of the silver halide photographic material having the same to form an image and subjecting the image to a photographic process. A silver halide emulsion with a high chloride content in the material is represented by the formula: [Wherein n is 1, 2 or 3, R is hydrogen, halogen, alkyl, alkoxy, amino, amide, sulfonamide, carboxy, etc., and p is 0, 1 or 2. ] Containing polyhydroxybenzene,
And, the outermost hydrophilic layer coated on the same side as the silver halide emulsion layer of the support contains wax-like polyolefin particles having an average particle size in the range of 0.5 to 3 μm. Method.