The mechanism of hypertension following acute NO synthase blockage is via endothelin-mediated vasoconstriction. Thus, NO appears to inhibit endothelin activity by blocking its expression and not as a chronic direct acting vasodilator. Administration of an endothelin antagonist to a patient in a xe2x80x98normalxe2x80x99 physiological state may result in specific regional vasodilation. This treatment finds utility in the treatment of erectile dysfunction.

This invention relates to methods for down-regulating local endothelin-mediated vasoconstrictor and/or vascular growth activity in xe2x80x9capparentlyxe2x80x9d normal physiological conditions in order to re-establish normal control in specific regions of the circulation which demonstrate pathophysiology. More particularly this invention relates to the administration of agents which antagonize the expression or activity of endothelin for the treatment of abnormalities of specific regions of the vasculature such as in erectile dysfunction in male patients.
Endothelins were first described in 1988 and have been shown to be powerful vasoconstrictors, predominantly found in the vascular endothelium and, since that time, numerous endothelin antagonists and pharmaceutically acceptable salts thereof have been identified and can be obtained commercially (e.g., Sigma, American Peptides). Attention is also directed to U.S. Pat. No. 5,284,828 issued Feb. 8, 1994 to Hemmi et al., U.S. Pat. No. 5,378,715 issued Jan. 3, 1995 to Stein et al. and U.S. Pat. No. 5,382,569 issued Jan. 17, 1995 to Cody et al., which describe in detail the chemical structures of various endothelin antagonists, and to U.S. Pat. No. 5,338,726 issued Aug. 16, 1994 to Shinosaki et al., which describes the chemical structure of endothelin converting enzyme inhibitors, the disclosures of which are incorporated herein by reference. To date, however, antagonists of endothelin have not been approved for therapeutic use, although a number of investigators have postulated that endothelin antagonists could be used for conditions ranging from renal failure, endotoxic shock, asthma, angina, or diabetes to pulmonary hypertension and possibly other indications.
Under normal physiological conditions, endothelin can be found in almost all parts of the circulation at very low levels. In general, in the normal rodent circulation endothelin (ET) is not found in elevated quantities and appears to have minimal effect in the normal regulation of vascular tone, i.e., there is no appreciable decrease in blood pressure when an endothelin antagonist is administered by injection in normal circulation. Further, at present there does not appear to be any evidence suggesting that ET plays a physiological role even in a small portion of the circulation under normal conditions in experimental models. However, it is likely that the circulation may appear normal when in fact a specific region of the circulation reveals pathophysiological changes, such as occurs with erectile dysfunction. Penile erection demands specific local vasodilation and/or inhibition of local vasoconstrictor mechanisms. It is not surprising that findings of elevated levels of endothelin in the blood are not widespread, as the regulation of ET action indicates a release preferentially towards the smooth muscle side, away from the circulation. In addition, it is highly improbable that there would be increased ET found in the circulation resulting from increased activity in a small portion of the circulation. ET is known to have a very short half-life.
It is widely known that administration of nitric oxide (NO) can provoke powerful vasodilator responses. The chronic role of nitric oxide synthase (NOS) as a vasodilator has only been inferred by indirect means, i.e., by removal of the NOS activity. Endogenously, there is much more redundancy in control of vasodilatation. For example, vasodilation can be induced by acetylcholine, bradykinin, adenosine triphosphate (ATP), histamine, vasoactive intestinal polypeptide (VIP), and leukotrienes, amongst others. The actions of these endogenous modulators have been shown to be dependent on the presence of the endothelium, an effect likely mediated by endothelial derived relaxing factor /NO (EDRF/NO) (1,2,3). Other vasodilator mechanisms exist which are not endothelium dependent, such as xcex22-adrenergic, arial natriuretic peptide (ANP) and certain prostaglandins. The actions of NO appear to be mostly cGMP-mediated via guanylate cyclase activation, although other mechanisms have been suggested. Garg and Hassid (1, 2) and others (4,5) demonstrated a difference in the effects of NO-generating vasodilator agents in inhibiting vascular smooth muscle cell growth in culture; however, it is clear that NO can act not only as a vasodilator but also to inhibit vascular growth responses in a number of conditions (6).
In the last several years a large number of studies has demonstrated that decreased NO production using inhibitors of NO synthase (e.g., Nxcfx89-nitro-L-arginine-methyl ester or L-NAME) produces dose-dependent hypertension (i.e., L-arginine reversible, and which correlates with decreased cyclic guanosine monophosphate (cGMP)) (7,8,9). Data from Schiffrin""s (4,10) and Morton""s (11) groups demonstrate that prolonged high dose L-NAME hypertension is associated with hypertrophic changes in the mesenteric vasculature (1 media thickness and 1 media/lumen ratio). Interestingly, Schiffrin""s group found that the degree of change in vascular structure was less marked than in other models (2K1C) with equivalent hypertension and of a similar duration. Taken together with the findings of NO development of cardiac hypertrophy and slower vascular changes, current evidence indicates that L-NAME hypertension is quite different from other models. Further, although these findings could suggest a role for NO as a modulator of vascular structure, our recent findings suggest that NO may play a more important inhibitory role in suppressing the activity of the endothelin vasoconstrictor system. The concept of NO suppression of ET expression is further supported by evidence both from Luscher""s group in vitro and from the Clozel group (12) in vivo showing that there is increased release of ET from endothelial cells after NOS blockage. These data suggest that exogenous administration of NO synthase antagonists produces a condition wherein the lack of NO appears to be a modulator of ET expression and release. Recent findings, in particular from Schiffrin""s group (13,14), in deoxycorticosterone acetate (DOCA)-salt hypertension point to a trophic role for endogenous endothelin in the development of vascular structural changes. They found that there is increased ET-1 gene expression and immunoreactivity in blood vessels, but not in the plasma, of DOCA-salt hypertensive rats, whereas renin angiotensin system (RAS) activity was decreased. There was a substantial development of vascular hypertrophy in the DOCA-salt model which was markedly attenuated by treatment with an ETA/ETB receptor antagonist. The concept that ET-1 is a vascular trophic factor is further supported by findings in studies with cultured vascular smooth muscle cells showing that addition of endothelin produces a mitogenic response (15), as well as findings in other in vivo studies indicating a role in structural changes associated with pulmonary hypertension (16). ET-1 is approximately 100 times more potent as a vasoconstrictor than Ang II or catecholamines. Interestingly, in the culture studies, although the maximal growth response to ET-1 was less than half of that for Ang II, the combination of ET-1 plus Ang II provoked a greater mitogenic response than either peptide alone. We are not aware of any studies that have assessed the in vivo cardiovascular growth responses to direct endothelin infusion.
An important aspect of the invention derives from the development of a concept which reveals an interrelationship between NO activity and endothelin vasoconstrictor activity, in vivo: specifically, that NO acts primarily as a chronic inhibitor of endothelin-mediated vasoconstriction, and less as a chronic vasodilator. Accordingly, it is proposed that endothelin plays a role in disease conditions associated with impaired NO synthesis, particularly if the pathophysiology is restricted to a specific portion of the circulation; i.e., if the entire circulation were altered, numerous compensatory changes in neurohumoral systems would also occur.
Our hypothesis is that if NO synthesis is inhibited, a significant increase in mean arterial pressure (MAP) is the result of increased endothelin release and this MAP increase can be eliminated by administration of an endothelin antagonist. It is apparent, therefore, that administration of an endothelin antagonist in physiological conditions where NO production is inhibited will result in vasodilation ONLY in the regions which have upregulated ET activity consequent, in part, to a down regulation of local NO production. Physiological conditions where NO production is inhibited in a local circulation, such as male erectile dysfunction, indicate that suppression of endothelin activity would offer an effective treatment.
Based on the understanding that a significant portion of the underlying problem in clinical erectile function relates to xe2x80x9cvascularxe2x80x9d mechanisms, much of the current state-of-the-art research involves determining the contribution that the different vascular effector control systems make in normal and pathophysiological states. There is substantial understanding of the hemodynamic events that lead to an erection, and yet the quantitative roles of each of the neuroeffector, humoral and local systems in these events remain poorly described. Since 1990, nitric oxide (NO) has been considered the primary non-adrenergic noncholinergic neurotransmitter in the penis and has been presumed to be the primary mediator of corporal relaxation during erection.
The issue of xe2x80x9cimpotencexe2x80x9d was discussed at the National Institutes of Health (NIH) in Washington in December 1992 (defined as xe2x80x9ca pattern of persistent or recurrent inability to develop or maintain an erection of sufficient rigidity for successful coitusxe2x80x9d) and has clearly been identified as having a wide range of causative or associated factors. The Massachusetts Male Aging Study (MASS) has provided us with an updated view of the epidemiology of erectile dysfunction although there seem to be some unchangeable truthsxe2x80x94it is accepted that the prevalence of impotence increases with age (Kinsey, 1948) (17). Complete erectile dysfunction (ED) increases from 5 to 15% between 40 and 70 years of age, Feldman, 1994 (18). ED has been shown to be xe2x80x9cdirectly correlated with heart disease, hypertension, diabetes, Associated medications, indices of anger and depression, and inversely with serum dehydroepiandosterone, high density lipoprotein, cholesterol and an index of dominant personality.xe2x80x9d
It is now estimated that in North America there are more than 30,000,000 men with ED, a significant increase from the figure of 10,000,000 used just 10 years ago (Shabsigh et al., 1988 (19); Whitehead, 1988 (20); Furlow, 1985 (21)). From these figures it is also reasonable to estimate that as many as three million Canadian men may have a degree of ED. The direct cost of treating impotence is impressive. Reliable figures for 1985 show that the cost of treating impotence exceeded 146 million dollars in the United States in that year alone (National Center for Health Statistics) and this number is just the estimated market size for one type of injectable therapy. The secondary effects and indirect costs associated with erectile dysfunction would suggest that impotence and sexual dysfunction are medical icebergs. The consequences of sexual dysfunction may be seen in strains on the host relationship potentially leading to marital breakdown, violence, work related sequelae, deviant sexual behavior, and impacts on children, when present, that can carry the damage into a new generation of unwanted behaviors. If ED underlies even a small but significant percentage of marital and family breakdown, then it adds vastly to the social and economic burden in society. The pragmatic issue is that large numbers of men are now being treated for ED and most of the treatments are fairly blunt instruments (intracavernosal injection (ICI) of mixed vasoactive compounds, penile prosthesis insertion) with significant cost and complications (ICI: pain, priapism, dislike of the technique; prostheses: reoperation, infection, distortion of body image).
As a medical and scientific problem, ED gained greatly in stature when Rajfer et al. (1992) (22) published their information linking nitric oxide (NO) with normal erectile function. It was an interesting coincidence that NO became xe2x80x9cMolecule of the Yearxe2x80x9d that same year as a result of the accumulated and established work in other vascular systems. This heralded a new maturity in the study of EDxe2x80x94suddenly the principles of normal vascular biology (NVB) became accepted as the underpinnings of erectile physiology.
The stimulus to erection is central and neural in origin. A fully functional penile erection requires coordinated input from various levels of the central nervous system and at least three sets of peripheral nerves (thoracolumbar sympathetic, saccral parasympathetic, and pelvic somatic). Adrenergic, non-adrenergic and non-adrenergic non-cholinergic neurotransmitter systems of importance have been identified in the cavernous tissue (Saenz de Tejada, 1988) (23). An excellent account of the neural processes (without specific roles) involved in the production of a penile erection can be found in the review by deGroat and Steers (1988) (24).
A penile erection is dependent upon the integration of anatomic, vascular (hydraulic; arterial and venous), endocrine, neurologic and hormonal mechanisms. The erectile components of the penis are the corpora cavernosa and the corpus spongiosum. The latter contributes little to the rigidity of the penis when erect. The corpora cavernosa are paired cylinders that are firmly and separately anchored to the inferior pubic rami at their proximal roots, where they are covered by striated muscle (ischiocavernosus), become joined in the proximal pendulous shaft and fenestrated (i.e., functionally connected) distally. There is usually one supplying end-artery per cavernosal body, from the internal iliac artery, that branches to become the deep penile artery which has at least two types of branches within the cavernosa: The venous drainage of the corpora is through the intermediate system for the distal cavernosa and glans and through the deep system for the remaining cavernosae. The critical venous channels are the subtunical veins, which empty through emissary veins that pass through the tunica and drain into the deep dorsal vein. It is the emissary veins that are compressed during erection and permit the xe2x80x9clockedxe2x80x9d state of veno-occlusion.
It is well established that, for erection, neurally mediated (autonomic) vasodilation of the penile arterial blood vessel and the trabecular meshwork takes place (Lue et al., 1987) (25) permitting extra blood flow into the cavernous bodies of the penis. The expanding intracorporal volume traps the effluent veins that lie between the erectile tissue and the surrounding, relatively inelastic, fibrous tunica albuginea. The outflow capacity is thereby decreased and entrapment of blood ensues, resulting in the transformation of the flaccid penis into its erect state (Juenemann et al., 1986 (26); Lue et al., 1987 (25); Lue et al., 1983 (27); Weiss, 1980 (28)). Inflow arterial tone is of absolute importance in this process, although adequate driving blood pressure (BP) is a necessary factor. The converse, detumescence, is mediated by the sympathetic nervous system (Saenz de Tejada, 1988 (23); Juenemann et al., 1989 (29)) and is dependent on the metabolic viability of cells within the erectile tissue. A maximal direct pharmacological vasodilator stimulus may not produce an erection in a penis driven by the high sympathetic nervous system activity state induced by fear. Thus, it is not surprising that alterations in blood flow and vascular dynamics, whether produced by decreased cardiac output, reflex sympathetic hyperactivity, atherosclerosis, untreated hypertension, antihypertensive medication or, as herein proposed, increased local endothelin-mediated vasoconstriction, can produce profound effects on the ability of the flaccid penis to be transformed into the erect state.
The known control systems for erection are conventionally described under the 3 headings: adrenergic, cholinergic and non-adrenergic non-cholinergic (NANC). Adrenergic nerve fibers and high concentrations of norepinephrine can be found in the corpora (Melman and Henry, 1979 (30); Benson et al., 1980 (31)) and the contractile properties of phenylephrine are established unequivocally (Hedlund et al., 1984 (32); Christ et al., 1990 (33)) with post-synaptic xcex11 effects acting directly and pre-synaptic xcex12 modulation. Previously, parasympathetic nerves were thought to be the nerves responsible for erection (Wagner et al., 1980 (34)), although the in vitro effects from acetylcholine (ACh) were varied in early experiments (Adaikan et al., 1983 (35); Hedlund et al., 1985 (32)). Further, simple intracorporal injection of acetylcholine does not cause erection and atropine does not block it (Wagner et a., 1980) (34). Thus, cholinergic nerves are described as modulators of neural function. Accordingly, NANC innervation, as the pre-eminent player in erectogenesis, has received intense scrutiny and the current thinking is that nitric oxide has replaced VIP as the prime vasodilator of this system in the penis. This view was first published by Ignarro et al. (36) and has been re-stated many times since. Not surprisingly, a variety of other NANC systems have also been shown to play a role in erectile function, including vasoactive intestinal polypeptide (VIP) (Gu et al., 1983 (37) and4 (38); Willis et al., 1983 (39)), calcitonin gene related peptide (CGRP) (Stief, 1990) (40) and the prostaglandins (Hedlund and Andersson,.1985) (41). The terms that have been used to describe the neuroeffector systems and the roles they play provide an historic basis for descriptions of penile systems but have not removed the confusion that is found in the more than 100 relevant papers that have been published since 1990 on neural regulation. It is without doubt that penile erections occur when arterial dilation and smooth muscle relaxation take place. The penis is an ideal vascular bed to consider in terms of the physiological opposition of neural effector systems involved in both relaxation and contraction i.e. the penis is one of only a small handful of special circulations with dual vasoconstrictor and vasodilator neural control systems; To fully characterize the penile control systems, a greater understanding of the countervailing systems both in a clinical and an experimental setting is required in order to elucidate the critical balance and interdependence that are essential for normal function.
As described, in order for penile tumescence to occur, the pudendal vascular bed must vasodilate to shunt blood flow to the cavernosal tissue. Normal vascular beds have a balance of vasodilators and vasoconstrictors regulating the level of vascular tone. Upsetting of this balance can lead to an enhanced chronic vasoconstrictor response. Chronic erectile dysfunction creates a situation where the penile vascular bed has seen chronic low oxygen partial pressures pO2. Low pO2 has been shown to decrease the activity of NO synthase and hence NO production. Further, it has also been shown, in rats, that the activity of the NO synthase enzyme decays with age. Both of these concepts in combination with our novel findings indicate a key role for enhanced endothelin-mediated vasoconstriction. Once enhanced endothelin occurs, there are three levels of mechanisms that will sustain the erectile dysfunction: (i) enhanced vasoconstriction in the penile vascular bed occurs, making it more xe2x80x98difficultxe2x80x99 for the vasodilators to shunt blood to the penis to facilitate cavernosal filling (this is also a positive feedback loop with respect to NO synthase since less blood flow will maintain low pO2 values); (ii) endothelin has been shown in vitro and in vivo to promote cardiovascular growth processes. This could lead to a structural change where blood vessels grow and encroach on the lumen, leading to increased resistance due to a structural mechanism (as opposed to chronic vasoconstriction); and (iii) enhanced endothelin may act as a xe2x80x98primerxe2x80x99 for other vasoconstrictor systems (renin-angiotensin system and sympathetic nervous system) which additionally act as trophic factors (i.e., the endothelin may prime the vascular bed such that Ang II, for example, will promote growth at doses that by themselves would not normally induce growth processes).
In summary, an upregulation of endothelin actions occurs when the production of NO is inhibited. This chronic enhanced endothelin, we propose, will be involved in mediating the changes leading to erectile dysfunction. Acutely, there will be enhanced vasoconstriction via the endothelium (endothelin) and, in the longer term, endothelin-mediated growth responses in the vascular tissue. The penile vascular tissue would, therefore, go through a structural change such that it would become more and more difficult to cause vasodilation with the progression of encroachment into the lumen of the vessels leading to the penis, as well as in the corpus cavernosal tissue itself.
There are several approaches that lead to the down regulation of the activity of endothelin, namely (a) peptide antagonists such as PD145065 (Parke Davis), (b) non-peptide antagonists such as bosentan (Hoffman-LaRoche) (42), (c) inhibitors of endothelin converting enzyme, such as for example phosphoramidon (i.e., blocking production of endothelin) and (d) antisense oligonucleotides which specifically block the translation of the endothelin protein at the genetic level, i.e., disrupt the normal cycle of events with preproendothelin mRNA.
Thus, it is an object of the present invention to provide a method for treating physiological conditions in which NO production is at least partially inhibited, such as, but not limited to, erectile dysfunction (ED).
Another object of this invention is to provide compositions of matter for the treatment of physiological conditions in which NO production is at least partially inhibited.
By one aspect of this invention, there is provided a method for treating physiological conditions in which NO production is at least partially inhibited, comprising administering to a patient in need thereof an effective amount of an agent which will antagonize the actions of endothelin (antisense to ET-mRNA, or ET antagonists, ECE antagonists).
By another aspect of this invention, there is provided a composition for use in the treatment of physiological conditions in which NO production is at least partially inhibited, comprising an effective amount of an endothelin antagonist or pharmaceutically acceptable salt thereof in admixture with a pharmaceutically acceptable carrier therefor,
In a preferred aspect, said physiological condition is erectile disfunction.

Method of ameliorating erectile dysfunction


A photographic element comprising a film support base, an adhesion promoting layer, a subbing layer and at least one light-sensitive silver halide emulsion layer, wherein the adhesion promoting layer is close to the support and contains a silane compound and a polyurethane, and the subbing layer, selected within the group consisting of a hydrophilic colloidal layer or a layer comprising a continuous gelled network of inorganic particles, is positioned between the adhesion promoting layer and the emulsion layer.

1. Field of the Invention
This invention relates to photographic elements having a film support carrying an adhesion promoting layer on at least one side thereof
2. Background of the Art
Polyester film-forming materials have been used as supports in photographic materials due to their many favorable properties, including their excellent transparency. Polyester supports, such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), triacetyl cellulose, polystyrene, polycarbonate and polyolefin laminate are examples of common polyesters. However, such polymer films have a hydrophobic surface and therefore, when the polymer is employed as the base film of the support for a photographic material, it is difficult to firmly bond to the support a photographic emulsion layer comprising a hydrophilic polymer (hydrophilic colloid), especially where mainly containing gelatin.
Two processes have been utilized as conventional techniques to overcome the above difficulty:
(1) a process in which a photographic emulsion layer is directly formed on the support to obtain a high bonding strength after having provided the support with a surface activation treatment (such as a corona discharge treatment, a glow discharge treatment, an active plasma treatment, a chemical treatment, a mechanical treatment, a UV treatment and equivalent processes); and
(2) a process in which an adhesion promoting layer is provided on the support subjected to the above surface treatment by coating, and then a photographic emulsion layer is formed thereon.
The latter process is effective and is widely performed commercially.
It is assumed that surface treatments are effected by forming some polar groups on a surface of a base film (which is originally hydrophobic) and by increasing a cross linking density on that surface, and as a result, it is considered that the affinity of the components contained in the adhesion promoting layer with the polar group is increased or the bonding strength between the adhesion promoting layer and the base film is enhanced.
Some useful compositions for adhesion promoting layers include polymers containing vinylidene chloride such as vinylidene chloride/methyl acrylate/itaconic acid terpolymers or vinylidene chloride/acrylonitrile/acrylic acid and the like; butadiene-based copolymers, glycidyl acrylate or methacrylate containing copolymers; or maleic anhydride-containing copolymers. These and other suitable compositions described, for example, in U.S. Pat. Nos. 2,627,088; 2,698,240; 2,943,937; 3,143,421; 3,201,249; 3,271,178; 3,443,950 and 3,501,301 provide the required adhesion when applied before orientation but are not effective when applied on oriented support. The effectiveness of these adhesive materials may be enhanced by the use of swelling or attack agents in the compositions, such materials, for example, including resorcinol.
An alternative approach to improving the enhancement of adhesion between the film support and gelatin layers disclosed in U.S. Pat. No. 4,695,532 is described as a discharge-treated polyester film support having coated directly thereon a crosslinked layer of an aqueous vinyl acrylate copolymer and gelatin. Although this system has good adhesion before processing, the adhesion performance is severely degraded by photographic developing solutions.
U.S. Pat. No. 4,689,359 discloses a polymer composition comprising (a) 1 to 60 wt. % of recurring units derived from a vinyl monomer having a primary amine addition salt component and/or a vinyl monomer having an aminostyrene addition salt component; (b) 0 to 50 wt. % of recurring units derived from a hydrophilic vinyl monomer and (c) 20 to 98 wt. % of recurring units from a hydrophobic non-ionic vinyl monomer. The polymers are useful in aqueous coating compositions, particularly for coating onto discharge-treated polyester film supports to form cross-linked layers to promote adhesion between the film support and the other emulsion layers in photographic elements such as silver halide emulsion layers. U.S. Pat. No. 5,639,589 and EP Application 729,063 describe polyester photographic film supports comprising a surface coated with a subbing layer comprising a mixture of gelatin and the same polymer composition described in U.S. Pat. No. 4,689,359. High dry adhesion, even with a thinner subbing layer and/or a higher gelatin:polymer ratio, is obtained.
U.S. Pat. No. 5,532,118 discloses photographic elements comprising a polyester film support having coated thereon a self-crosslinking polyurethane derived from an isocyanate terminated prepolymer extended with an aliphatic polyamine and end-capped with N-methylol hydrazide groups, the prepolymer being derived from a diisocyanate and a polyester polyol and having carboxylic salt groups on the polymer chain. The photographic element disclosed therein exhibits good wet and dry adhesion, before and after photographic processing.
U.S. Pat. No. 5,510,233 discloses a photographic material having a first and a second adhesion promoting layer and an emulsion layer coated in this order on the same side of a polyester support base, in which the first adhesion promoting layer is a hardened layer comprising a polyurethane latex and an ethoxy compound or a dichloro-s-triazine derivative, and the second adhesion promoting layer is a hydrophilic colloidal layer substantially consisting of gelatin. The polyurethane latex has breaking elongation lower than or equal to 300% or a tensile stress of at least 130 kg/cm2 at 100% elongation. The composition of the adhesion promoting layers improves adhesion between the emulsion layer and the support and prevents delamination even under prolonged storage at high humidity condition. It also prevents the coated emulsion from cracking even at extremely low humidity storage. An additional advantage is the resistance against reticulation at the processing and the background clarity of the processed images.
U.S. Pat. No. 5,378,592 discloses a photographic material comprising a support of a polyester film, a first subbing layer provided thereon, a second subbing layer comprising gelatin provided on the first subbing layer and a photographic layer provided on the second subbing layer. The first subbing layer is a layer of polymer latex cured with an epoxy-type compound or a dichloro-s-triazine derivative, or the first subbing layer comprises a polymer which has a breaking elongation lower than or equal to 300% or a tensile stress of at least 130 kg/cm2. In particular, the photographic material contains an epoxy compound having not less than 4 epoxy groups (preferably 4 to 5).
U.S. Pat. No. 5,726,001 discloses a composite support comprising a polymeric film having coated thereon an electrically conductive layer and an auxiliary layer coated over the electrically conductive layer, wherein the polymeric film comprises a surface which has been activated by energetic treatment, and wherein the composite support further comprises an adhesion promoting layer comprising an aqueous dispersible, aliphatic, anionic polyurethane binder having a breaking elongation of at least 350% either between the polymeric film and the electrically conductive layer or between the electrically conductive layer and the auxiliary layer, and the electrically conductive layer or adhesion promoting layer is in contiguous contact with the activated surface of the polymeric film. The invention provides composite supports and imaging elements containing an electrically conductive antistatic layer having excellent adhesion to energetic surface-treated polymer film supports, and of auxiliary layers to the electrically conductive antistatic layer.
U.S. Pat. No. 5,707,791 discloses a silver halide photographic light-sensitive material with excellent adhesive property and scratch-resistance comprising: (a) a polyester support; (b) a silver halide emulsion layer coated on one side of said polyester support; (c) a resin layer coated on the other side of said polyester support, said resin layer comprising an antistatic agent selected from the group consisting of a conductive polymer and a metal oxide, and a resin selected from the group consisting of an aqueous-dispersible polyester resin and an aqueous-dispersible polyurethane resin; and (d) a magnetic layer coated on said resin layer.
U.S. Pat. No. 5,204,219 discloses a polymeric film having adhered to at least one surface thereof a layer comprising a continuous gelled network of inorganic particles containing from 0.1 to 20% by weight of solid content of said layer of an ambifunctional silane, where the term ambifunctional silane means that the compound has reactive silanes on one end of the molecule and a different reactive species capable of reacting with a photographic hardener for gelatin or directly with gelatin. This second functionality enables the compound to react with the inorganic particle (through the silane group) and also react with the gelatin (reacting with the gelatin hardener which also reacts with the gelatin).
However, it is still desirable to provide polyester film supports having improved adhesion of emulsion layers coated thereon both in wet and dry conditions.
A photographic element comprises a film support base, an adhesion promoting layer, a subbing layer and at least one light-sensitive silver halide emulsion layer. The adhesion promoting layer is close to the support and contains a silane compound and a polyurethane, and the subbing layer (selected within the group consisting of a hydrophilic colloidal layer or a layer comprising a continuous gelled network of inorganic particles) is positioned between the adhesion promoting layer and the emulsion layer.
The present invention also refers to a photographic element comprising a film support base having coated on one side thereof at least one light-sensitive silver halide emulsion layer and on the opposite side thereof an adhesion promoting layer and at least one auxiliary layer, wherein the adhesion promoting layer is close to the support and contains a silane compound and a polyurethane.
The present invention further refers to a film support base having coated on at least one side thereof an adhesion promoting layer and a subbing layer, wherein the adhesion promoting layer is close to the support and contains a silane compound and a polyurethane and the subbing layer is a hydrophilic colloidal layer comprising a continuous gelled network of inorganic particles.
Finally, the present invention also refers to a film support base having coated on one side thereof an adhesion promoting layer and at least an auxiliary layer, wherein the adhesion promoting layer is close to the support and contains a silane compound and a polyurethane binder and the auxiliary layer is an antistatic layer, a magnetic layer, a protective layer or a lubricant layer.
The adhesion of emulsion layers and/or of auxiliary layers to the support base is improved under both wet and dry conditions.
The layers of the photographic element can be coated on a variety of supports, such as cellulose ester supports (e.g., cellulose triacetate supports), paper supports, polyester film supports (e.g., polyethylene terephthalate or PET film supports and polyethylene naphthalate or PEN film supports), and the like, as described in Research Disclosure 308119, Section XVII, 1989. Preferred supports are the polyester film supports prepared from any of the polyester compositions described, for example, in U.S. Pat. Nos. 2,943,937 or 2,627,088. Among the suitable polyesters for use as supports include those prepared from dicarboxylic acids or derivatives thereof, such as terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, adipic acid, succinic acid and mixtures thereof and glycols, such as, ethylene glycole, propylene glycole, butylene glycole, hexamethylene glycole, cyclohexane diol and mixtures thereof. Especially useful polyester film supports are polytethylene terephthalate (PET) or polyethylene naphthalate (PEN).
The supports preferably are initially treated with a surface activation treatment such as, for example, a corona discharge treatment, a glow discharge treatment, an active plasma treatment, a chemical treatment, a mechanical treatment, a UV treatment, a flame treatment, and the like. The preferred methods are corona discharge treatment, as described, for example, in U.S. Pat. Nos. 4,055,685; 4,135,932; 4,220,471 and 5,194,291; and glow discharge treatment as described, for example, in U.S. Pat. Nos. 3,288,638; 4,451,497; 4,933,267 and 5,425,980.
Light-sensitive photographic elements generally consist of a film support base coated with at least one silver halide emulsion layer on one side thereof and auxiliary layers on the other side of the support. The adhesion promoting layer of the present invention is close to the support and it may be applied on the emulsion side or on the side opposite thereto.
The adhesion promoting layer may be applied to the film support either during or after the preparation of the film support. That is, in the preparation of film supports, the polymer is melt extruded into a sheet and subsequently oriented by stretching it in both longitudinal and transversal directions and then treated by several steps including heat treating, heat relaxing, annealing and the like. The adhesion promoting layer may be applied at any stage in the known process of preparing photographic film base, such as prior to orienting, between the orienting steps, or before or after any of the subsequent steps in the preparation of the support. The application of the adhesion promoting layer is particularly advantageous after completion of the support.
Polyurethane compounds have been known since the discovery in 1937 of diisocyanate addition polymerization. The term polyurethane compound does not mean a polymer that only contains urethane groups, but means all those polymers that contain significant numbers of urethane groups, regardless of what the rest of the molecule may be. Homopolymers of isocyanates are usually referred to as isocyanate polymers. Usually polyurethane compounds are obtained by the reaction of polyisocyanates with polyhydroxy compounds, such as polyethers, polyester, castor oils, or glycols, but compounds containing groups such as amino and carboxyl groups may also be used. Thus, a typical polyurethane compound may contain in addition to urethane groups aliphatic and aromatic hydrocarbon residues, ester groups, ether groups, amide groups, urea groups, and the like. The urethane group has the following characteristic structure:
and polyurethane compounds have a significant number of these groups, although they do not necessarily repeat in a regular order. The most common method of forming polyurethane compounds is by reacting di- or polyfunctional hydroxy compounds, such as hydroxyl-containing (e.g., terminated) polyesters or polyethers, with di- or polyfunctional isocyanates. Examples of useful diisocyanates are represented by the following formula:
wherein R can be represented by substituted or unsubstituted alkylene, cycloalkylene, arylene, alkylenebisarylene, arylenebisalkylene, etc. groups. Examples of disocyanates within the formula above are 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4xe2x80x2-diphenylmethane diisocyanate, dianisidine diisocyanate, toluidine diisocyanate, naphthylene diisocyanate, hexamethylene diisocyanate, m-xylydene diisocyanate, pyrene diisocyanate, isophorone diisocyanate, ethylene diisocyanate, propylene diisocyanate, octadecylene diisocyanate, methylenebis(4-cyclohexyl isocyanate) and the like.
Examples of di- or polyfunctional hydroxy compounds are hydroxyl-containing polyethers and polyesters having a molecular weight of from 200 to 20,000, preferably of from 300 to 10,000. Most of the polyethers used for the manufacture of polyurethanes are derived from polyols and/or poly(oxyalkylene) derivatives thereof Examples of useful polyols include: 1) diols such as alkylene diols of 2-10 carbon atoms, arylene diols such as hydroquinone, and polyether diols [HO(RO)nH] where R is alkylene, 2) triols such as glycerol, trimethylol propane, 1,2,6-hexanetriol, 3) tetraols such as pentaerythritol, and 4) higher polyols such as sorbitol, mannitol, and the like. Examples of polyesters used for the manufacture of polyurethanes are saturated polyesters having terminal hydroxy groups, low acid number and low water content, derived from adipic acid, phthalic anhydride, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, diethylene glycol, 1,2,6-hexanetriol, trimethylolpropane, trimethylolethane, and the like. Other desirable polyols include castor oil (a mixture of esters of glycerol and fatty acids, the most relevant thereof is the ricinoleic acid), lactones having end hydroxyl groups (such as polycaprolactone), and block copolymers of propylene and or ethylene oxide copolymerizered with ethylenediamine.
Polyurethane dispersions are well-known in the art; in fact, they have been disclosed, for example, in U.S. Pat. Nos. 2,968,575, 3,213,049, 3,294,724, 3,565,844, 3,388,087, 3,479,310 and 3,873,484. Polyurethane products commercially available are, for example, Neorez(trademark) R551 sold by Zeneca Resins, Sancure(trademark) 1301 and Sancure(trademark) 2710 sold by BF Goodrich, Witcobond(trademark) series produced by Witco Chemical Co., Takelak(trademark) XW-76-P15 produced by Takeda Yakuhin Kogyo and Bahydrol(trademark) produced by Bayer.
Useful polyurethane dispersions are neutral or they are anionically or cationically stabilized. Anionically or cationically stabilized dispersions are formed by incorporating charged groups into the polyurethane molecule. Useful groups which impart a negative charge to the dispersion include carboxylate, sulfonate and the like. Useful repeating units are derived from polyol monomers containing these acidic functional groups such as 2,2-bis(hydroxymethyl)-propionic acid, N,N-bis-(2-hydroxyethyl)-glycine and the like. Among useful groups that impart a positive charge to the dispersion include quaternized amines, sulfonium salts, phosphinates and the like. Useful repeating units are derived from polyol monomers containing a tertiary amine or a thio-functional group such as N-methyldiethanolamine, 2,2xe2x80x2-thioethanol and the like. Useful examples of anionically and cationically stabilized polyurethane dispersions are disclosed in U.S. Pat. Nos. 3,479,710 and 3,873,484.
Any method known in the art for the preparation of a polymeric dispersion can be used for the preparation of polyurethane dispersions useful in the present invention. In a preferred embodiment, polyurethane dispersions are prepared by polymerization in emulsion. By this method, polyurethane dispersions are prepared by extending of a prepolymer chain, the prepolymer being the reaction product of an isocyanate with an organic compound having at least two reactive hydrogen atoms. Organic compounds having at least two reactive hydrogen atoms include the above-mentioned bis- or polyfunctional hydroxy compounds. Polyurethane dispersions are generally prepared by emulsifying the prepolymer and then extending the chain in the presence of a chain extending agent.
The prepolymer is prepared by mixing the organic compounds having at least two reactive hydrogen atoms and the diisocyanate compound, in nitrogen atmosphere and then stirring. A useful temperature is comprised in the range between about 25xc2x0 C. and 110xc2x0 C. The reaction is preferably done in the presence of a solvent and, additionally, of a catalyst. Useful solvents include ketones and esters, aliphatic hydrocarboxy solvents such as heptane, octane, etc., and cycloaliphatic hydrocarbons such as methylcycloesane, etc. Useful catalysts include tertiary amines, acids and organometallic compounds such as triethylamine, stannous chloride, and di-n-buthyl tin dilaurate. When both the reagents and the prepolymer are in liquid form, the organic solvent may be absent.
Following the prepolymer preparation, the dispersion is prepared by emulsifying the prepolymer and extending the chain thereof in the presence of water and, optionally, of a surfactant. When the prepolymer contains charged groups, the addition of a surfactant may be unnecessary. The prepolymer chain extending is realized by adding a chain extending agent to the emulsified prepolymer. Useful chain extending agents include water, hydrazine, primary and secondary diamines, aminoalcohols, aminoacids, hydroxyacids, diols or mixtures thereof. A preferred group of chain extending agents include water and primary and secondary diamines, such as 1,4-cyclohesanbis(methylamine), ethylendiamines, diethylenetriamines, etc., the molar amount of the chain extending agent being typically equal to the equivalents of the isocyanate of the prepolymer.
The adhesion promoting layer preferably is coated at a polyurethane coverage of from about 0.01 to 1 g/m2, more preferably 0.015 to 0.5 g/m2.
The silane compounds useful in the present invention are ambifunctional silane compounds represented by the formula (Q)n-Rxe2x80x94Sixe2x80x94(ORxe2x80x2)3, wherein R is an organic group having n+1 valences or bonds, Rxe2x80x2 is alkyl or aryl, Q is a moyety capable of reacting with the support or the coated primer on the support, n is 1, 2 or 3. Q is preferably an epoxy group or an amino group (primary or secondary). Preferred ambifunctional silane compounds contained in the adhesion promoting layer of the present invention include epoxy-silanes and amino-silanes, as described in U.S. Pat. Nos. 5,204,219 (Van Ooij et al.), 5,439,789 (Boston et al.); U.S. Pat. No. 5,411,787 (Kulkarni et al.); and U.S. Pat. No. 5,882,466 (Grootaert et al.).
Preferred epoxy-silane compounds useful in the present invention are xcex3-glycidoxy-propyl-trimethoxy-silane, and xcex2-(3,4-epoxycyclohexyl)ethyl-trimethoxy-silane. These epoxy-silane compounds can be prepared according to methods known in the art, such as for example the methods described in W. Noll, Chemistry and Technology of Silicones, Academic Press (1968), pp. 171-34 and in Journal of American Chemical Society, vol. 81 (1959). p. 2632.
Epoxy-silane compounds may be added to the adhesion promoting layer as neat liquids, as solids, or as solutions in suitable solvents. The epoxy-silane compounds may be hydrolyzed completely or partially before addition. By xe2x80x9cpartially hydrolyzed,xe2x80x9d it is meant that not all of the hydrolyzable silicon-alkoxide (alkoxy-silane) or silicon-carboxylate groups have been removed from the silane upon reaction with water. Hydrolysis of epoxy-silane compounds is conveniently done in the presence of water and a catalyst such as an acid, a base, or a fluoride ion. The hydrolyzed epoxy-silane compounds may exist as siloxane polymers or oligomers resulting from condensation of silanol groups produced in the hydrolytic reaction of the epoxy-silane compound with other silanol groups or with unreacted silicon-alkoxide or silicon-carboxylate bonds. It may be desirable to add epoxy-silane compounds in the form of co-hydrolysates or co-hydrolysates and co-condensates with other, non-epoxy-silane compounds.
Useful amino-silane compounds include, for example, 3-amino-propyl-trimethoxy-silane, 3-aminopropyl-triethyoxy-silane, addition products of 3-glycidoxypropyl-alkoxy-silane and secondary hydroxy alkylamines, and mixtures thereof. Amino-silane compounds, are further described in U.S. Pat. No. 5,411,787 (Kulkarni et al.) and can be further blended with other silane coupling agents, such as methyl-trimethoxy-silane, dimethyl-diethoxy-silane, methacrylolpropyl-trimethoxy-silane, dialkylamine addition products of glycidoxypropyl-alkoxysilane, and tripropylamine addition products of glycidoxypropyl-dimethoxy-silane. Other examples of useful aminosilane compounds include, for example, 3-aminopropyl-triethoxy-silane, N-(2-aminoethyl)-3-aminopropyl-trimethoxy-silane, N-(2-vinylbenzylamino)ethyl-3-aminopropyl-trimethoxy-silane, 4-aminobutyl-triethoxy-silane, (aminoethyl-aminomethyl)phenethyl-trimethoxy-silane, xcex2-(2-aminoethyl)-3-aminopropylmethyl-dimethoxy-silane, xcex2-(2-aminoethyl)-3-aminopropyl-tris(2-ethyl-hexoxy)-silane, 6-(aminohexylaminopropyl)-trimethoxy-silane, p-amino-phenyl-trimethoxy-silane, 3-(1-aminopropoxy)-3,3-dimethyl-1-propenyl-tri-methoxy-silane, 3-aminopropyltris(methoxyethoxyethoxy)-silane, 3-amino-propylmethyl-diethoxy-silane, 3-aminopropyl-triethoxy-silane, 3-aminopropyl-trimethoxy-silane, xcfx89-aminoun-decyl-trimethoxy-silane, and those further described in U.S. Pat. No. 5,882,466 (Grootaert et al.).
The ambifunctional silane compounds as described above, can be present in the adhesion promoting layer in any amount that will provide effective adhesion-promoting properties. For example, the adhesion promoting layer can contain a polyurethane binder to silane compounds ratio from 1:1 to 100:1, preferably from 5:1 to 20:1. Further, for example, the ambifunctional silane compound is contained in the adhesion promoting layer in an amount from about 1 to about 50 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts of the adhesion promoting layer.
A primer layer may be used between the support itself and the adhesion promoting layer, as known in the art. Primer layers are, in fact, generally considered to be part of the support itself unless specifically excluded in the description (e.g., unprimed polyester). Primer compositions are well known in the art and include polymers of vinylidene chloride, diazo compounds, acrylic resins crosslinked with melamine resins, and polyester resins.
When the adhesion promoting layer is applied on the emulsion side, a subbing layer is directly bonded to the adhesion promoting layer and is positioned between the adhesion promoting layer and the silver halide emulsion layer in order to better improve the adhesion of the emulsion layer to the adhesion promoting layer. Subbing layers include hydrophilic colloid layers or layers comprising a continuous gelled network of inorganic particles.
Suitable hydrophilic colloidal materials include both naturally occurring substances such as proteins, protein derivatives, cellulose derivatives such as cellulose esters; gelatin including alkali-treated and acid-treated gelatin, phthalated gelatin, and the like; polysaccharides such as dextran, gum arabic, zein, casein, pectin, collagen derivatives, collodion, agar-agar, arrowroot, albumin and the like. The hydrophilic colloidal layer composition preferably comprises a dispersion of the hydrophilic colloid in water at a percentage of at least 2% by weight of the resulting composition. Gelatin is the most preferred hydrophilic colloid. Other hydrophilic colloidal materials which can be used include poly(vinyllactams), acrylamide polymers, polyvinyl alcohol and its derivatives, polyvinyl acetals, polymers of alkyl and sulfoalkyl acrylates and methacrylates, hydrolyzed polyvinyl acetates, polyamides, polyvinyl pyridine, acrylic acid polymers, maleic anhydride copolymers, polyalkylene oxides, methacrylamide copolymers, polyvinyl oxazolidinones, maleic acid copolymers, vinylamine copolymers, methacrylic acid copolymers, acryloyloxyalkylsulfonic acid copolymers, sulfoalkylacrylamide copolymers, polyalkyleneimine copolymers, polyamines, N,N-dialkylaminoalkylacrylates, vinyl imidazole copolymers, vinyl sulfide copolymers, halogenated styrene polymers, aminoacrylamide polymers, polypeptides, and the like. Other exemplary colloids are disclosed, for example in U.S. Pat. Nos. 2,691,582; 2,787,545; 2,956,880; 3,132,945; 3,138,846; 3,679,425; 3,706,564; 3,813,251; 3,852,073; 3,879,205; 3,003,879; 3,284,207; 3,748,143 and 3,536,491.
Suitable layers comprising a continuous gelled network of inorganic particles are disclosed in U.S. Pat. No. 5,204,219. Inorganic metal oxides particularly suitable are those in which the metal oxide particles are negatively charged and include tin oxides, titanium oxides, antimony oxides, silica, and alumina-coated silica, as well as other inorganic metal oxides of Groups III and IV of the Periodic Table and mixtures thereof The selection of the inorganic metal oxides is dependent upon the ultimate balance of properties desired. Inorganics such as silicon nitride, silicon carbide, and magnesium fluoride, when provided in sol form, are also useful.
When the adhesion promoting layer is coated on the polyester film support base on the side opposite to the emulsion side, auxiliary layers including, for example, antistatic layers, anti-halation layers, magnetic layers, protective or lubricant layers can be directly overcoated onto the adhesion promoting layer, with or without the need of a subbing layer. Antistatic layers and anti-halation layers are disclosed, for example, in Research Disclosure, Item 17643, December 1978 to prevent undesirable static discharges during manufacture, exposure and processing of the imaging element. Antistatic layers conventionally used in color films have been found to be satisfactory used herewith. Any of the antistatic agents described, for example, in U.S. Pat. Nos. 4,374,924; 4,943,520; 5,147,768 and 5,582,963 can be used. Preferred antistatic agents include metal oxides, such as, for example, tin oxide, antimony doped tin oxide, vanadium pentoxide, antimony doped vanadium pentoxide, silver doped vanadium pentoxide and mixtures thereof as described, for example, in U.S. Pat. Nos. 5,407,603; 5,427,835; 5,439,785; 5,468,498 and 5,709,985. Transparent magnetic recording layers as described, for example, in U.S. Pat. Nos. 5,147,768; 5,215,874; 5,217,804; 5,250,404 and 5,395,743, are useful to record magnetic information. Ferromagnetic particles are generally employed in such magnetic layers. Protective or lubricating layers can contain known compounds such as, for example, suitable lubricants including silicone oil, silicones having polar groups, higher fatty acid glycerides, higher alcohol esters of higher fatty acids, waxes, alcohols, polyolefins, alkyl phosphates, alkyl sulfates, siloxanes and the like, as described, for example, in EP Patent Applications 751,423; 833,194 and 855,619 and in U.S. Pat. Nos. 5,723,270; 5,747,234; 5,766,836; U.S. Pat. Nos. 5,821,027; 5,843,631 and 5,491,051.
Suitable silver halide emulsions can be any of the silver halide emulsions known in the art, such as silver chloride, silver bromide, silver bromo-chloride, silver chloro-iodide, silver bromo-iodide, silver chloro-bromo-iodide emulsions and mixtures thereof The emulsions can be composed of coarse, medium and fine grains and can be monodispersed or polydispersed. The silver halide grains may be those having a regular crystal form, such as a cube or an octahedron, or those having an irregular crystal form, such as spherical or tabular, etc., or may be those having a composite crystal form. They may be composed of a mixture of grains having different crystal forms. Their size can be varied on a wide range, but in general average grain sizes from 0.1 to 4 mm are suitable.
The silver halide emulsions may be obtained according to any of the known acid, neutral and ammoniacal method using conventional precipitation methods such as a single or twin jet method. Further, the silver halide emulsions may be chemically sensitized with a sulfur sensitizer, such as allylthiocarbamide, thiourea, cystine, etc.; an active or inert selenium sensitizer; a reducing sensitizer such as stannous salt, a polyamine, etc.; a noble metal sensitizer, such as gold sensitizer, more specifically potassium aurithiocyanate, potassium chloroaurate, etc.; or a sensitizer of a water soluble salt such as for instance of ruthenium, rhodium, iridium and the like, more specifically, ammonium chloropalladate, potassium chloroplatinate and sodium chloropalladite, etc.; each being employed either alone or in a suitable combination.
Furthermore, the above silver halide emulsions may contain various known additives for photography. For example, there may be employed additives for photography as disclosed in Research Disclosure, Item 17643, December 1978. Specifically hydrophobic photographic additives include dye-forming couplers, development-inhibitor-releasing, (DIR) couplers, silver halide developers, oxidized developer scavengers, spectral sensitizers and desensitizers, diffusion transfer dye image-formers, visible and ultraviolet light absorbers, which are conventionally introduced into hydrophilic colloid layers of photographic elements dispersed in water-immiscible high boiling solvents. Other hydrophobic photographic additives include those used in silver halide photographic elements, such as optical brighteners, antioxidants, silver halide solvents, bleachable dyes and the like. Hydrophobic photographic additives for use in the present invention are described in more details in Research Disclosure 15930, July 1977.
Moreover, the silver halides may be optically sensitized to a desired region of the visible spectrum. The method for spectral sensitization is not particularly limited. For example, optical sensitization may be possible by using an optical sensitizer, including a cyanine dye, a merocyanine dye, complex cyanine and merocyanine dyes, oxonol dyes, hemioxonol dyes, styryl dyes and streptocyanine dyes, either alone or in combination. Particularly useful optical sensitizers are the dyes of the benzoxazole-, benzimidazole- and benzothiazole-carbocyanine type.
The above emulsions may also contain various additives conveniently used depending upon their purpose. These additives include, for example, stabilizers or antifoggants such as azaindenes, triazoles, tetrazoles, imidazolium salts, polyhydroxy compounds and others; film hardeners such as of the aldehyde, aziridine, isoxazole, vinylsulfone, acryloyl, triazine type, etc. type; developing promoters such as benzyl alcohol, polyoxyethylene type compounds, etc.; image stabilizers such as compounds of the chromane, cumarane, bisphenol type, etc. Also, coating aids, surfactants for improved coatability, modifiers of the permeability in the processing liquids, defoaming agents, and matting agents, such as, polymethyl methacrylate beads, may be used if desired. Further, the auxiliary layer may contain a lubricant, such as wax. Suitable lubricants include silicone oil, silicones having polar groups, and the like, as described, for example, in U.S. Pat. No. 5,532,118.
The photographic emulsions can be used for black-and-white light-sensitive negative elements, light-sensitive positive elements, X-Ray elements, lithographic elements, black-and-white and color light-sensitive elements for diffusion transfer processes and light-sensitive elements which contain oil-soluble or water-soluble color couplers.
Preferably, the silver halide emulsions are designed for multicolor elements comprising dye image forming units sensitive to each of the three primary regions (blue, green and red) of the visible spectrum. Each unit can be formed by a single emulsion layer or multiple emulsion layers sensitive to the same spectral region.
More preferably, the silver halide emulsions are designed for a multicolor element comprising a support bearing at least one blue-sensitive silver halide emulsion layer and preferably two blue-sensitive silver halide emulsion layers of different sensitivity associated to yellow dye forming couplers, at least one green sensitive silver halide emulsion layer and preferably at least two green-sensitive silver halide emulsion layers of different sensitivity associated to magenta dye forming couplers, at least one red-sensitive silver halide emulsion layer and preferably at least two red-sensitive silver halide emulsion layers of different sensitivity associated to cyan dye forming couplers, and additional non light-sensitive hydrophilic colloidal layers (such as protective layers, intermediate layers, filter layers, subbing layers, backing layers and the like), wherein at least one component layer of said material comprises incorporated therein a hydrophilic photographic additive dispersed with the aid of a water-immiscible high boiling organic solvent according to the present invention, said component layers comprising preferably at least one silver halide emulsion layer including a dye forming coupler.
The photographic elements can be processed after exposure to form a visible image. Processings can be the common ones employed to develop color photographic elements. A negative colored image can be obtained by color development followed by bleaching and fixing. Development is obtained by contacting the exposed silver halides of the element with an alkaline aqueous medium in the presence of an aromatic primary amine color developing agent contained in the medium or in the material, as known in the art. The aromatic primary amine color developing agents used in the photographic color developing compositions can be any of the known compounds of the class of p-phenylendiamine derivatives, widely employed in various color photographic process. Particularly useful color developing agents are the p-phenylenediamine derivatives, especially the N,N-dialkyl-p-phenylenediamine derivatives wherein the alkyl groups or the aromatic nucleus can be substituted or not substituted.
Examples of p-phenylenediamine developers include the salts of: N,N-diethyl-p-phenylenediamine, 2-amino-5-diethylamino-toluene, 4-amino-N-ethyl-N-(xcex1-methanesulphonamidoethyl)-m-toluidine, 4-amino-3-methyl-N-ethyl-N-(xcex1-hydroxyethyl)-aniline, 4-amino-3-(xcex1-methylsulfonamidoethyl)-N,N-diethylaniline, 4-amino-N,N-diethyl-3-(Nxe2x80x2-methyl-xcex1-methylsulfonamido)-aniline, N-ethyl-N-methoxy-ethyl-3-methyl-p-phenylenediamine and the like, as described, for instance, in U.S. Pat. Nos. 2,552,241; 2,556,271; 3,656,950 and 3,658,525.
Examples of commonly used developing agents of the p-phenylene diamine salt type are: 2-amino-5-diethylaminotoluene hydrochloride (gene-rally known as CD2 and used in the developing solutions for color positive photographic materials), 4-amino-N-ethyl-N-(xcex1-methanesulfonamidoethyl)-m-toluidine sesquisulfate monohydrate (generally known as CD3 and used in the developing solution for photographic papers and color reversal materials) and 4-amino-3-methyl-N-ethyl-N-(xcex2-hydroxyethyl)-aniline sulfate (generally known as CD4 and used in the developing solutions for color negative photographic materials).
The color developing agents are generally used in a quantity from about 0.001 to about 0.1 moles per liter, preferably from about 0.0045 to about 0.04 moles per liter of photographic color developing compositions.
In the case of color photographic materials, the processing comprises at least a color developing bath and, optionally, a prehardening bath, a neutralizing bath, a first (black and white) developing bath, etc. These baths are well known in the art and are described for instance in Research Disclosures 17643, 1978, and 308119, Sections XIX and XX, 1989.
After color development, the image-wise developed metallic silver and the remaining silver salts generally must be removed from the photographic element. This is performed in separate bleaching and fixing baths or in a single bath, called xe2x80x9cblixxe2x80x9d, which bleaches and fixes the image in a single step. The bleaching bath is a water solution having a pH equal to 5.60 and containing an oxidizing agent, normally a complex salt of an alkali metal or of ammonium and of trivalent iron with an organic acid, e.g., EDTA.Fe.NH4, wherein EDTA is the ethylenediamino-tetracetic acid, or PDTA.Fe.NH4, wherein PDTA is the propylenediaminotetraacetic acid. While processing, this bath is continuously aired to oxidize the divalent iron which forms while bleaching the silver image and regenerated, as known in the art, to maintain the bleach effectiveness. The bad working of these operations may cause the drawback of the loss of cyan density of the dyes.
Further to the above mentioned oxidizing agents, the blix bath can contain known fixing agents, such as for example ammonium or alkali metal thiosulfates. Both bleaching and fixing baths can contain other additives, e.g., polyalkyleneoxide compounds, as described for example in GB patent 933,008 in order to increase the effectiveness of the bath, or thioether compounds known as bleach accelerators.

Photographic element with a layer improving the adhesion to the support base

Abstract: The present invention further refers to a film support base having coated on at least one side thereof an adhesion promoting layer and a subbing layer, wherein the adhesion promoting layer is close to the support and contains a silane compound and a polyurethane and the subbing layer is selected within the group consisting of a hydrophilic colloidal layer or a layer comprising a continuous gelled network of inorganic particles.

Abstract: The adhesion of the emulsion layers and/or of the auxiliary layers to the support base is improved both under wet and dry conditions.