This invention relates to photographic silver halide materials. ⁵ European Patent Specification 0 246 766 (or

US Patent 782 Oil) describes the stabilisation of photographic dye images using a bisphenol derivative having two linked phenol rings, one of the phenolic hydroxy groups being substituted and at least one of -*** ⁰ the phenol rings being substituted.

We have now found that the same bisphenol compounds will, in silver chloride emulsions suitable for processing in a colour developer free of benzyl alcohol, ensure that the performance of a certain * ^■ ---' class of yellow couplers is maximised.

According to the present invention therefore there is provided a photosensitive photographic colour material suitable for processing in a colour developer free of benzyl alcohol comprising a support bearing a ^Q silver halide emulsion, the halide content of which is at least 85% chloride, which contains in or adjacent said silver halide layer:

(1) a bisphenol derivative having two linked phenol rings, one of the phenolic hyroxy groups 5 being substituted and at least one of the phenol rings being substituted, and

(2) a ballasted yellow coupler of the general formula:

wherein L ¹ is -NHS0 ₂ , -S0 ₂ NH-, -OCO-, -COO--, -OS0 ₂ - or -S0-O-,

R is halogen or an alkyloxy group of 1-4 carbon atoms,

2 R is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl group of sufficient size and configuration to render the coupler non—diffusible in the photographic material, and

X is a halogen, aryloxy, arylthio or heterocyclic coupling—off group.

The photographic materials of the present invention containing the combination of said stabilisers and said yellow image dye-forming couplers show maximised coupler performance as measured by higher D„ma„„x and/or gamma and reduced D-m-,i.n of the dye image. Other known dye image stabilisers do not have this effect. Dye image stabilisation is also superior to that obtained with other known stabilisers.

2 The ballasting groups R may include alkyl and/or aryl moieties optionally linked by ether or ester groups. Examples of such groups which may be employed are:

-(CH ₂ ) ₁₅ Me, -(CH ₂ ) _n -Me,

The coupling—off group X may be chlorine a heterocyclic group or an aryloxy or arylthio group optionally substituted with alkyl or arylsulphonyl, alk lsulphonamido, or alkoxycarbonyl groups which

themselves are optionally substituted. Preferred coupling—off groups are phenoxy groups containing electron—withdrawing substituents at the ortho- and/or para positions, especially at the para- and one ortho-position. In addition, ionisable substituents are also beneficial. Examples of coupling-off groups that may be used are the following:

NHS0 ₂ Bu-n

HSO CH

(f) / V so ₂ - -OH

< >

^(ε -°- _ ^{*" S0} 2- ._ -° ^CH 2-< ^'

(h)

(i)

(j)

Examples of couplers according to the present invention are listed in the following Table.

TABLE 1

Coupler R

1 Cl - CH ₂ ) ₁₅ Me (f) -NHSO, 2 CH ₃ 0-„ -(CH ₂ ) ₁₅ Me (c)

Cl -(CH ₂ ) ₁₁ Me ⁽ g)

^t_C 5 ^H ll

Cl -(CH ₂ ) - ^" - ^C 5 ^H ll ^{"t (f} >

5 Cl C ₁₂ H ₂₅ -n (k) -CO-O- 6 Cl ^C 16 ^H 33 ^~n (k) -0-S0 -

A preferred group of stabilisers is represented by the following general formula

wherein

A is a blocking group such as alkyl e.g. methyl, ethyl, propyl or butyl; cycloalkyl e.g. cyclohexyl; alkenyl; aryl e.g. phenyl; acyl e.g. acetyl or benzoyl; alkylsulphonyl or arylsulphonyl;

L is a single bond or a linking group such as alkylene e.g. methylene; alkylidene e.g. butylidene or

3,5,5,—trimethylhexylidene; a heteroatom e.g. oxygen or sulphur; or sulphonyl; and, each R independently represents one or more substituents each independently selected from alkyl, alkoxy, alkenyl, cycloalkyl, or aryl; or each R independently represents the atoms necessary to complete with the benzene ring to which it is attached a fused polycyclic aromatic ring structure; all the above mentioned alkyl, cycloalkyl, alkylene, alkenyl, acyl and aryl groups being optionally substituted.

Particularly preferred stabilizers are represented by the general formula

wherein

A and L are as defined above; and, / *c c

R , R , R and R each independently represent substituted or unsubstituted alkyl, alkenyl, cycloalkyl or aryl. Preferably, R 3 and R4 are identical and R and R are identical.

Alkylidene bisphenols represent a preferred group of stabilizers in which the linking group L may be -(CR ⁷ R ⁸ ) _n - wherein each of R ⁷ and R ⁸ independently is hydrogen or optionally substituted alkyl, cycloalkyl, alkenyl or aryl and n is an integer from 1 to 10, preferably 1 to 3, most preferably 1.

Specific examples of a stabilizer suitable for use in the present invention are as follows:

CH ₃ CH ₂ -C ₄ H ₉ -t Compound (1)

Compound (2)

Compound (3)

Other examples are listed in European Specification 0 246 766.

The silver halide preferably comprises at least 95% chloride and is preferably substantially pure silver chloride.

Typically both the coupler and the bisphenol derivative are dissolved in a coupler solvent and this solution is dispersed in an aqueous gelatin solution. Examples of coupler solvents that may be used are dibutyl phthalate, tricresyl phosphate, diethyl lauramide and 2,4—di—tertiary—amylphenol. In addition an auxiliary coupler solvent may also be used, for example ethyl

acetate, cyclohexanone, and 2—(2—butoxy—ethoxy)ethyl acetate, which are removed from the dispersion before incorporation into the photographic material.

The photographic elements can be single colour elements or multicolour elements. In a multicolour element, the yellow dye-forming couplers of this invention would usually be associated with a blue—sensitive emulsion, although they could be associated with an emulsion sensitised to a different region of the spectrum, or with a panchromatically sensitised, orthochromatically sensitised or unsensitised emulsion. Multicolour elements contain dye image— orming units sensitive to each of the three primary regions of the spectrum. Each unit can be comprised of a single emulsion layer or of multiple emulsion layers sensitive to a given region of the spectrum. The layers of the elements, including the layers of the image— orming units, can be arranged in various orders as known in the art. A typical multicolour photographic element comprises a support bearing a yellow dye image—forming unit comprised of at least one blue—sensitive silver halide emulsion layer having associated therewith at least one yellow dye—forming coupler and magenta and cyan dye image— orming units comprising at least one green— or red—sensitive silver halide emulsion layer having associated therewith at least one magenta or cyan dye—forming coupler respectively. The element can contain additional layers, such as filter layers. in the following discussion of suitable materials for use in the emulsions and elements of this invention, reference will be made to Research Disclosure, December 1978, Item 17643, published by Industrial Opportunities Ltd., The Old Harbourmaster's, 8 North Street, Emsworth, Hants P010 7DD, U.K. This

publication will be identified hereafter as "Research Disclosure".

The silver halide emulsion employed in the elements of this invention can be either negative-working or positive-working. Suitable emulsions and their preparation are described in Research Disclosure Sections I and II and the publications cited therein. Suitable vehicles for the emulsion layers and other layers of elements of this invention are described in Research Disclosure Section IX and the publications cited therein.

In addition to the couplers of this invention, the elements of the invention can include additional couplers as described in Research Disclosure Section VII, paragraphs D, E, F and G and the publications cited therein. The couplers of this invention and any additional couplers can be incorporated in the elements and emulsions as described in Research Disclosures of Section VII, paragraph C and the publications cited therein.

The photographic elements of this invention or individual layers thereof, can contain brighteners (see Research Disclosure Section V), antifoggants and stabilisers (see Research Disclosure Section VI), antistain agents and image dye stabiliser (see

Research Disclosure Section VII, paragraphs I and J), light absorbing and scattering materials (see Research Disclosure Section VIII), hardeners (see Research Disclosure Section XII, plasticisers and lubricants (see Research Disclosure Section XIII), matting agents (see Research Disclosure Section XVI) and development modifiers (see Research Disclosure Section XXI).

The photographic elements can be coated on a variety of supports as described in Research Disclosure Section XVII and the references described

therein.

Photographic elements can be exposed to actinic radiation, typically in the visible region of the spectrum, to form a latent image as described in Research Disclosure Section XVIII and then processed to form a visible dye image as described in Research Disclosure Section XIX. Processing to form a visible dye image includes the step of contacting the elements with a colour developing agent to reduce developable silver halide and oxidise the colour developing agent. Oxidised colour developing agent in turn reacts with the coupler to yield a dye.

Preferred colour developing agents are p—phenylene diamines. Especially preferred are 4—amino-3—methyl—N,N-diethylaniline hydrochloride,

4—amino—3—methyl—N—ethyl—N—β—(meth lanesulphonamido)- ethylaniline sulphate hydrate, 4-amino-3-meth l-N- eth l—N-$—(methanesulphonamido)ethyl—N,N-dieth 1— aniline hydrochloride and 4-amino-N-ethyl—N-(2—methoxy- ethyl)-m-toluidine di—p-toluene sulphonate.

With negative-working silver halide emulsions this processing step leads to a negative image. To obtain a positive (or reversal) image, this step can be preceded by development with a non-chromagenic developing agent to develop exposed silver halide, but not form dye, and then uniform fogging of the elements to render unexposed silver halide developable. Alternatively, a direct positive emulsion can be employed to obtain a positive image. Development is followed by the conventional steps of bleaching, fixing, or bleach-fixing, to remove silver and silver halide, washing and drying.

The invention is illustrated by the following Examples.

Example 1

Two dispersions of Coupler (1) in gelatin, with and without added Compound (1), were prepared by ultrasonic agitation (Dawe Instruments "Soniprobe"). Details of the method are given below:

(i) Oil Solution:

Coupler (1) 3.28g dibutyl phthalate 0.82g 2-(2-butoxyethoxy)ethyl acetate 0.82g

Compound (1) 1.64g

♦

(ii) Gel Solution:

12.5% aq. gelatin solution 36.Og 10% aq. diisopropylnaphthalene sulphdnic acid sodium salt 2.0ml The components of the oil solution were heated together at 120°C to effect solution. A small quantity of ethyl acetate (0.5g) was added to help this process and this was evaporated off before continuing. The gelatin mixture, melted at 60°C, was added to the hot oil and the mixture agitated with the ultrasonic probe for 4 minutes and chilled.

A similar dispersion of a check Coupler (A) (.identified below) without stabiliser was also prepared.

The Coupler (1) dispersions were coated with a blue-sensitive AgCfi. emulsion to give coatings of the following structure:

Layer 1

Layer 2

*BVSME = bis-vinylsulphonylmethyl ether

The Coupler (A) dispersion was coated similarly except that the coupler coverage was increased to 0.753g per square metre. The coatings were wedge-exposed and developer using RA4 processing solutions. Sensitometric parameters were recorded and the sample strips were then faded for 10 days through a UV filter in front of a high intensity light source (Xenon Arc, 50 Klux). The loss of dye density from an initial value of 1.0 was recorded. The results are shown in the table below:

Coating D(min D(max) Gamma Fade

1.81 2.95 -0.17 2.13 3.28 -0.60

2.10 3.42 -0.12

The gamma, or contrast, values shown in the table can be taken to represent the photographic activity of the coatings. It is clear that the presence of Compound (1) improved the performance Coupler (1), and that both Coupler (1) coatings were superior to the Coupler (A) check, notwithstanding the 28% higher coverage of the check coupler. Coupler (A) has the formula:

I C0 ₂ Me

The recorded fades show that the presence of the stabiliser produces a substantial improvement in the light stability of the coupler (1) image dye, to the extent that it surpasses that of the (unstabilised) check. Example 2

Further Coupler (1) dispersions were prepared and coated as in Example 1, containing, respectively, no stabiliser, and various stabilisers including some outside the present invention. Compared with Example 1, the coating coverages were reduced to 0.382g per square metre coupler and 0.17g per square metre Ag. The coatings were evaluated in the same manner as in Example 1 and the Table below shows the results.

* 7 days 50 klux fade, density loss from 1.0

The gamma values in the table confirm the sensitometric benefit of Compound (1) and show similar behaviour for its analogue, Compound (2). In contrast, both o the comparison stabilisers,

Compound (A):

O 0 ^*

II II

(PhO) ₂ P-O-(CH ₂ ) ₁₀ -0-P(OPh) ₂ and Compound (B) (Irgaperm 1994 (trade of Ciba-Geigy)) were detrimental to sensitometr . Furthermore, these stabilisers were found to be significantly less effective than the two materials of this invention in reducing the fade of the image.

Example 3

Coatings were made and tested as described in

Example 1 using the couplers indicated below with

2 silver and coupler coverages at 0.465 g/m and

2 0.215 g/m respectively. The results were as follows.

Coating D(min) D(max) Gamma Fade

Coupler (5)* 0.18 2.13 2.46 -0.61 Coupler (5) + Compound (1) 0.10 2.15 2.45 -0.11

Coupler (6) 0.23 1.71 2.30 -0.81 Coupler (6) +

Compound (1) 0.18 1.78 2.52 -0.49

* 7 days 50 klux fade, density loss from 1.0 ** 21 days 50 klux fade, density loss from 1.0

Improvements are seen in not only in fade results but bbootthh Dmm. . Dmax„ and, for Coupler (6), gamma as well,