A soap bar composition containing: (a) an alkyl/alkenyl oligoglycoside; (b) an olefin sulfonate; and (c) a starch component, and wherein the soap bar composition is subtantially free of free fatty acids or their salts.

This invention relates to fatty-acid-free syndet bar soaps containing alkyl and/or alkenyl oligoglycosides, olefin sulfonates and starch.
Bar soaps play an important part in personal hygiene. Today, bar soaps are industrially produced by continuous saponification of free fatty acids with alkalis, concentration of the basic soaps and spray drying. A distinction is drawn between true alkali soaps, which contain only fatty acid salts and optionally free fatty acids, and so-called xe2x80x9ccombination barsxe2x80x9d, i.e. bar soaps whichxe2x80x94in addition to fatty acid saltsxe2x80x94contain other synthetic surfactants, generally fatty alcohol ether sulfates or fatty acid isethionates. By contrast, a special position is occupied by so-called xe2x80x9csyndet barsxe2x80x9d which, apart from impurities, are free from fatty acid salts and contain only synthetic surfactants.
In Germany alone, several million bars of soap for personal hygiene are sold annually. However, the commercial requirements which these mass consumption articles are expected to satisfy are becoming increasingly more stringent. Bar soaps are required not only to clean, but also to care for the skin, i.e. to prevent the skin from drying out, to xe2x80x9crefatxe2x80x9d the skin and to protect it against outside influences. The soap is of course expected to be particularly compatible with the skin, but at the same time to produce an abundant and creamy foam in use and to have a pleasant feeling on the skin. In this connection, manufacturers of bar soaps are constantly looking for new ingredients which satisfy these increased requirements.
In recent years, alkyl glucosides have acquired significance as new nonionic surfactants because they behave like anionic surfactants in many respects, for example in their foaming power, and at the same time show extremely high ecological and dermatological compatibility. Accordingly, it was logical to experiment with such surfactants in connection with bar soaps. For example, toilet soaps containing 1 to 20% by weight of alkyl polyglucosides and preferably 55 to 66% by weight of soap as builder are known from European patent application EP 0 463 912 A (Colgate). Toilet soaps containing mild surfactants, including for example those of the alkyl polyglucoside type, are known from EP 0 227 321 A2, EP 0 308 189 B1 and EP 0 308 190 B1 (Procter and Gamble). In addition, DE 43 31 297 A1 and DE 43 37 031 A1 (Henkel) describe fatty-acid-salt-containing combination bars in which small quantities of alkyl polyglucosides are present. Finally, DE 1945136 C1 describes syndet bar soaps containing 5 to 25% by weight of alkyl and/or alkenyl oligoglycosides and 5 to 40% by weight of starch. However, the bar soaps obtainable in accordance with the teaching of the prior art do not always develop enough foam and, in addition, are unsatisfactory in regard to foam consistency and, in particular, the feeling they have on the skin. In addition, if free fatty acids are used as refatting agents, extremely serious corrosion problems can occur in manufacturing equipment.
Accordingly, the problem addressed by the present invention was to provide syndet soaps which would be free from the disadvantages described above. A particular factor to be taken into consideration in this regard was that the new bar soap compositions would also have to lend themselves to production on an industrial scale, i.e. they would be expected, for example, to show adequate, but not excessive moldability and would not have any tendency to form cracks on drying.
The present invention relates to syndet soaps containing
(a) alkyl and/or alkenyl oligoglycosides,
(b) olefin sulfonates and
(c) starch.
It has surprisingly been found that bar soaps with improved foaming behavior and an optimized feeling on the skin can be produced in the absence of fatty acids or fatty acid salts providing mixtures of alkyl and/or alkenyl oligoglycosides and olefin sulfonates, preferably in water-free form, are used as the surfactant component and starch is used as builder. The invention includes the observation that the mixtures are also eminently suitable for the industrial production of bar soaps, i.e. they are stable during storage in air, substantially non-hygroscopic and moldable and do not crack on drying.
Alkyl and/or Alkenyl Oligoglycosides
Alkyl and alkenyl oligoglycosides are known nonionic surfactants corresponding to formula (I):
R1Oxe2x80x94[G]pxe2x80x83xe2x80x83(I)
in which R1 is an alkyl and/or alkenyl radical containing 4 to 22 carbon atoms, G is a sugar unit containing 5 or 6 carbon atoms and p is a number of 1 to 10. They may be obtained by the relevant methods of preparative organic chemistry. EP 0 301 298 A1 and WO 90/03977 are cited as representative of the extensive literature available on the subject.
The alkyl and/or alkenyl oligoglycosides may be derived from aldoses or ketoses containing 5 or 6 carbon atoms, preferably glucose. Accordingly, the preferred alkyl and/or alkenyl oligoglycosides are alkyl and/or alkenyl oligoglucosides. The index p in general formula (I) indicates the degree of oligomerization (DP), i.e. the distribution of mono- and oligoglycosides, and is a number of 1 to 10. Whereas p in a given compound must always be an integer and, above all, may assume a value of 1 to 6, the value p for a certain alkyl oligoglycoside is an analytically determined calculated quantity which is generally a broken number. Alkyl and/or alkenyl oligoglycosides having an average degree of oligomerization p of 1.1 to 3.0 are preferably used. Alkyl and/or alkenyl oligoglycosides having a degree of oligomerization of less than 1.7 and, more particularly, between 1.2 and 1.4 are preferred from the applicational point of view.
The alkyl or alkenyl radical R1 may be derived from primary alcohols containing 4 to 11 and preferably 8 to 10 carbon atoms. Typical examples are butanol, caproic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and the technical mixtures thereof obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the hydrogenation of aldehydes from Roelen""s oxosynthesis. Alkyl oligoglucosides having a chain length of C8 to C10 (DP=1 to 3), which are obtained as first runnings in the separation of technical C8-18 coconut oil fatty alcohol by distillation and which may contain less than 6% by weight of C12 alcohol as an impurity, and also alkyl oligoglucosides based on technical C9/11 oxoalcohols (DP=1 to 3) are preferred. In addition, the alkyl or alkenyl radical R1 may also be derived from primary alcohols containing 12 to 22 and preferably 12 to 14 carbon atoms. Typical examples are lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, brassidyl alcohol and technical mixtures thereof which may be obtained as described above. Alkyl oligoglucosides based on hydrogenated C12/14 cocoalcohol with a DP of 1 to 3 are preferred.
Olefin Sulfonates
The syndet soaps according to the invention contain anionic surfactants obtainable by methods known per se as a further component. Olefin sulfonates are preferably obtained by addition of SO3 onto olefins corresponding to formula (II):
R2xe2x80x94CHxe2x95x90CHxe2x80x94R3xe2x80x83xe2x80x83(II)
in which R2 and R3 independently of one another represent H or alkyl groups containing 1 to 20 carbon atoms, with the proviso that R2 and R3 together contain at least 6 and preferably 10 to 16 carbon atoms. Particulars of their production and use can be found in a synoptic article published in J. Am. Oil. Chem. Soc. 55, 70 (1978). Internal olefin sulfonates may be used although xcex1-olefin sulfonates which are obtained R2 or R3 is hydrogen are preferably used. Typical examples of the olefin sulfonates used are the sulfonation products obtained by reacting SO3 with 1-, 2-butene, 1-, 2-, 3-hexene, 1-, 2-, 3-, 4-octene, 1-, 2-, 3-, 4-, 5-decane, 1-, 2-, 3-, 4-, 5-, 6-dodecene, 1-, 2-, 3-, 4-, 5-, 6-, 7-tetradecene, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-hexadecene, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-octadecene, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10-eicosene and 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10- and 11-docosene. The sulfonation is followed by a neutralization step, after which the olefin sulfonate is present in the mixture as an alkali metal, alkaline earth metal, ammonium, alkyl ammonium, alkanolammonium or glucammonium salt and preferably as a sodium salt. It is possible to use both paste-form aqueous olefin sulfonates, preferably at a pH value of 7 to 10, and also water-free products, preferably in the form of granules obtained by conventional spray drying, drying in a thin-layer evaporator (flash dryer, ctf. DE 19710152 C1, Henkel KGaA) or in a fluidized-bed dryer (SKET dryer).
Starch
It is particularly preferred to use wheat and/or corn starch which may be used in untreated form or preferably in digested, i.e. partly hydrolyzed, form. In one particular embodiment of the invention, compounds of alkyl glucosides, olefin sulfonates and starch are produced by subjecting aqueous slurries of the three components to drying with superheated steam, as described for example in German patent application DE 43 40 015 A1 (Henkel), to which reference is hereby specifically made. However, drying may also be carried out by other processes, for example in a horizontally arranged thin-layer evaporator (flash dryerxe2x80x9d) or in a fluidized-bed dryer (SKET dryer).
Surfactants
The syndet soaps according to the invention may also contain anionic, nonionic, cationic and/or amphoteric or zwitterionic surfactants as constituents which normally make up about 50 to 99% by weight and preferably 70 to 90% by weight of the syndet soaps. Typical examples of anionic surfactants are alkylbenzenesulfonates, alkanesulfonates, olefin sulfonates, alkylether sulfonates, glycerol ether sulfonates, xcex1-methyl ester sulfonates, sulfofatty acids, alkylsulfates, fatty alcohol ether sulfates, glycerol ether sulfates, fatty acid ether sulfates, hydrbxy mixed ether sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialkyl sulfosuccinates, mono- and dialkyl sulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and salts thereof, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, N-acylamino acids such as, for example, acyl lactylates, acyl tartrates, acyl glutamates, acyl aspartates, alkyl oligoglucoside sulfates, protein fatty acid condensates (particularly wheat-based vegetable products) and alkyl (ether) phosphates. If the anionic surfactants contain polyglycol ether chains, they may have a conventional homolog distribution although they preferably have a narrow homolog distribution. Typical examples of nonionic surfactants are fatty alcohol polyglycol ethers, alkylphenol polyglycol ethers, fatty acid polyglycol esters, fatty acid amide polyglycol ethers, fatty amine polyglycol ethers, alkoxylated triglycerides, mixed ethers and mixed formals, optionally partly oxidized alk(en)yl oligoglycosides or glucuronic acid derivatives, fatty acid-N-alkyl glucamides, protein hydrolyzates (particularly wheat-based vegetable products), polyol fatty acid esters, sugar esters, sorbitan esters, polysorbates and amine oxides. If the nonionic surfactants contain polyglycol ether chains, they may have a conventional homolog distribution, although they preferably have a narrow homolog distribution. Typical examples of cationic surfactants are quaternary ammonium compounds and esterquats, more particularly quaternized fatty acid trialkanolamine ester salts. Typical examples of amphoteric or zwitterionic surfactants are alkylbetaines, alkyl-amidobetaines, aminopropionates, aminoglycinates, imidazolinium betaines and sulfobetaines. The surfactants mentioned are all known compounds. Information on their structure and production can be found in relevant synoptic works, cf. for example J. Falbe (ed.), xe2x80x9cSurfactants in Consumer Productsxe2x80x9d, Springer Verlag, Berlin, 1987, pages 54 to 124 or J. Falbe (ed.), xe2x80x9cKatalysatoren, Tenside und Mineralxc3x6ladditive (Catalysts, Surfactants and Mineral Oil Additives)xe2x80x9d, Thieme Verlag, Stuttgart, 1978, pages 123-217.
Syndet Bar Soaps
Syndet bar soaps with a particularly favorable feeling on the skin and a creamy foam contain the ingredients in the following quantities:
(a) 5 to 25 and preferably 10 to 20% by weight of alkyl and/or alkenyl oligoglycosides,
(b) 5 to 50 and preferably 20 to 40% by weight of olefin sulfonates,
(c) 5 to 40 and preferably 15 to 30% by weight of starch and
(d) 0 to 20 and preferably 5 to 10% by weight of other surfactants,
with the proviso that the quantities add up to 100% by weight.
Other preferred constituents of the syndet bar soaps according to the invention are fatty alcohols and polyethylene glycol ethers. Typical examples of suitable fatty alcohols are lauryl alcohol, myristyl alcohol, cetearyl alcohol, stearyl alcohol and isostearyl alcohol. Suitable polyethylene glycol ethers are those which have an average molecular weight in the range from 5,000 to 20,000 dalton.
The syndet bar soaps according to the invention are substantially free from fatty acids or fatty acid salts, i.e. the content of these substances is below 0.5% by weight. Nevertheless, the soaps produce a surprisingly large amount of a particularly creamy foam in use and, in addition, have a particularly pleasant feeling on the skin.
Auxiliaries and Additives
The syndet soaps may contain oils, emulsifiers, superfatting agents, consistency providers, thickeners, polymers, silicone compounds, fats, waxes, stabilizers, waxes, biogenic agents, deodorizers, swelling agents, pigments, antioxidants, preservatives, hydrotropes, perfume oils, dyes and the like as further auxiliaries and additives.
Suitable oils are, for example, Guerbet alcohols based on fatty alcohols containing 6 to 18 and preferably 8 to 10 carbon atoms, esters of linear C6-22 fatty acids with linear C6-22 fatty alcohols, esters of branched C6-13 carboxylic acids with linear C6-22 fatty alcohols, esters of linear C6-22 fatty acids with branched alcohols, more particularly 2-ethyl hexanol, esters of hydroxycarboxylic acids with linear or branched C6-22 fatty alcohols, more particularly Dioctyl Malate, esters of linear and/or branched fatty acids with polyhydric alcohols (for example propylene glycol, dimer diol or trimer triol) and/or Guerbet alcohols, triglycerides based on C6-10 fatty acids, liquid mono-/di-/triglyceride mixtures based on C6-18 fatty acids, esters of C6-22 fatty alcohols and/or Guerbet alcohols with aromatic carboxylic acids, more particularly benzoic acid, esters of C2-12 dicarboxylic acids with linear or branched alcohols containing 1 to 22 carbon atoms or polyols containing 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear and branched C6-22 fatty alcohol carbonates, Guerbet carbonates, esters of benzoic acid with linear and/or branched C6-22 alcohols (for example Finsolv(copyright) TN), linear or branched, symmetrical or nonsymmetrical dialkyl ethers containing 6 to 22 carbon atoms per alkyl group, ring opening products of epoxidized fatty acid esters with polyols, silicone oils and/or aliphatic or naphthenic hydrocarbons.
Suitable emulsifiers are, for example, nonionic surfactants from at least one of the following groups:
(1) products of the addition of 2 to 30 moles of ethylene oxide and/or 0 to 5 moles of propylene oxide onto linear fatty alcohols containing 8 to 22 carbon atoms, onto fatty acids containing 12 to 22 carbon atoms and onto alkylphenols containing 8 to 15 carbon atoms in the alkyl group;
(2) C12/18 fatty acid monoesters and diesters of products of the addition of 1 to 30 moles of ethylene oxide onto glycerol;
(3) glycerol monoesters and diesters and sorbitan monoesters and diesters of saturated and unsaturated fatty acids containing 6 to 22 carbon atoms and ethylene oxide adducts thereof;
(4) alkyl mono- and oligoglycosides containing 8 to 22 carbon atoms in the alkyl group and ethoxylated analogs thereof;
(5) adducts of 15 to 60 moles of ethylene oxide with castor oil and/or hydrogenated castor oil;
(6) polyol esters and, in particular, polyglycerol esters such as, for example, polyglycerol polyricinoleate, polyglycerol poly-12-hydroxy-stearate and polyglycerol dimerate isostearate. Mixtures of compounds from several of these classes are also suitable;
(7) products of the addition of 2 to 15 moles of ethylene oxide onto castor oil and/or hydrogenated castor oil;
(8) partial esters based on linear, branched, unsaturated or saturated C6/22 fatty acids, ricinoleic acid and 12-hydroxystearic acid and glycerol, polyglycerol, pentaerythritol, dipentaerythritol, sugar alcohols (for example sorbitol), alkyl glucosides (for example methyl glucoside, butyl glucoside, lauryl glucoside) and polyglucosides (for example cellulose);
(9) mono-, di- and trialkyl phosphates and mono-, di- and/or tri-PEG-alkyl phosphates and salts thereof;
(10) wool wax alcohols;
(11) polysiloxane/polyalkyl polyether copolymers and corresponding derivatives;
(12) mixed esters of pentaerythritol, fatty acids, citric acid and fatty alcohol according to DE-PS 1165574 and/or mixed esters of fatty acids containing 6 to 22 carbon atoms, methyl glucose and polyols, preferably glycerol or polyglycerol, and
(13) polyalkylene glycols.
The addition products of ethylene oxide and/or propylene oxide with fatty alcohols, fatty acids, alkylphenols, glycerol monoesters and diesters and sorbitan monoesters and diesters of fatty acids or with castor oil are known, commercially available products. They are homolog mixtures of which the average degree of alkoxylation corresponds to the ratio between the quantities of ethylene oxide and/or propylene oxide and substrate with which the addition reaction is carried out. C12/18 fatty acid monoesters and diesters of addition products of ethylene oxide with glycerol are known as refatting agents for cosmetic formulations from DE-PS 20 24 051.
C8/18 alkyl mono- and oligoglycosides, their production and their use as surfactants are known from the prior art. They are produced in particular by reacting glucose or oligosaccharides with primary C8/18 alcohols. So far as the glycoside unit is concerned, both monoglycosides in which a cyclic sugar unit is attached to the fatty alcohol by a glycoside bond and oligomeric glycosides with a degree of oligomerization of preferably up to about 8 are suitable. The degree of oligomerization is a statistical mean value on which the homolog distribution typical of such technical products is based.
Zwitterionic surfactants may also be used as emulsifiers. Zwitterionic surfactants are surface-active compounds which contain at least one quaternary ammonium group and at least one carboxylate and one sulfonate group in the molecule. Particularly suitable zwitterionic urfactants are the so-called betaines, such as the N-alkyl-N,N-dimethyl ammonium glycinates, for example cocoalkyl dimethyl ammonium glycinate, N-acylaminopropyl-N,N-dimethyl ammonium glycinates, for example cocoacylaminopropyl dimethyl ammonium glycinate, and 2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazolines containing 8 to 18 carbon atoms in the alkyl or acyl group and cocoacylaminoethyl hydroxyethyl carboxymethyl glycinate. The fatty acid amide derivative known under the CTFA name of Cocoamidopropyl Betaine is particularly preferred. Ampholytic surfactants are also suitable emulsifiers. Ampholytic surfactants are surface-active compounds which, in addition to a C8/18 alkyl or acyl group, contain at least one free amino group and at least one xe2x80x94COOHxe2x80x94 or xe2x80x94SO3Hxe2x80x94 group in the molecule and which are capable of forming inner salts. Examples of suitable ampholytic surfactants are N-alkyl glycines, N-alkyl propionic acids, N-alkylaminobutyric acids, N-alkyliminodipropionic acids, N-hydroxyethyl-N-alkylamidopropyl glycines, N-alkyl taurines, N-alkyl sarcosines, 2-alkylaminopropionic acids and alkylaminoacetic acids containing around 8 to 18 carbon atoms in the alkyl group. Particularly preferred ampholytic surfactants are N-coco-alkylaminopropionate, cocoacylaminoethyl aminopropionate and C12/18 acyl sarcosine. Besides the ampholytic emulsifiers, quaternary emulsifiers may also be used, those of the esterquat type, preferably methyl-quaternized difatty acid triethanolamine ester salts, being particularly preferred.
Superfatting agents may be selected from such substances as, for example, lanolin and lecithin and also polyethoxylated or acylated lanolin and lecithin derivatives, polyol fatty acid esters, monoglycerides and fatty acid alkanolamides, the fatty acid alkanolamides also serving as foam stabilizers.
Suitable consistency providers are primarily fatty alcohols and hydroxyfatty alcohols containing 12 to 22 carbon atoms and preferably 16 to 18 carbon atoms and also partial glycerides, fatty acids or hydroxyfatty acids. A preferred consistency provider is a combination of these substances with alkyl oligoglucosides and/or fatty acid-N-methyl glucamides of the same chain length and/or polyglycerol-12-hydroxystearates. Suitable thickeners are, for example, polysaccharides, more especially xanthan gum, guar-guar, agar-agar, alginates and tyloses, carboxymethyl cellulose and hydroxyethyl cellulose, also relatively high molecular weight polyethylene glycol monoesters and diesters of fatty acids, polyacrylates (for example Carbopols(copyright) [Goodrich] or Synthalens(copyright) [Sigma]), polyacrylamides, polyvinyl alcohol and polyvinyl pyrrolidone, surfactants such as, for example, ethoxylated fatty acid glycerides, esters of fatty acids with polyols, for example pentaerythritol or trimethylol propane, narrow-range fatty alcohol ethoxylates or alkyl oligoglucosides and electrolytes, such as sodium chloride and ammonium chloride.
Suitable cationic polymers are, for example, cationic cellulose derivatives such as, for example, the quaternized hydroxyethyl cellulose obtainable from Amerchol under the name of Polymer JR 400(copyright), cationic starch, copolymers of diallyl ammonium salts and acrylamides, quaternized vinyl pyrrolidone/vinyl imidazole polymers such as, for example, Luviquat(copyright) (BASF), condensation products of polyglycols and amines, quaternized collagen polypeptides such as, for example, Lauryldimonium Hydroxypropyl Hydrolyzed Collagen (Lamequat(copyright) L, Grxc3xcnau GmbH), quaternized wheat polypeptides, polyethyleneimine, cationic silicone polymers such as, for example, Amidomethicone, copolymers of adipic acid and dimethylaminohydroxypropyl diethylenetriamine (Cartaretine(copyright), Sandoz AG), copolymers of acrylic acid with dimethyl diallyl ammonium chloride (Merquat(copyright) 550, Chemviron), polyaminopolyamides as described, for example, in FR 2 252 840 A and crosslinked water-soluble polymers thereof, cationic chitin derivatives such as, for example, quaternized chitosan, optionally in microcrystalline distribution, condensation products of dihaloalkyls, for example dibromobutane, with bis-dialkylamines, for example bis-dimethylamino-1,3-propane, cationic guar gum such as, for example, Jaguar(copyright)CBS, Jaguar(copyright)C-17, Jaguar(copyright)C-16 of Celanese, USA, quaternized ammonium salt polymers such as, for example, Mirapol(copyright) A-15, Mirapol(copyright) AD-1, Mirapol(copyright) AZ-1 of Miranol, USA.
Suitable anionic, zwitterionic, amphoteric and nonionic polymers are, for example, vinyl acetate/crotonic acid copolymers, vinyl pyrrolidone/vinyl acrylate copolymers, vinyl acetate/butyl maleate/isobornyl acrylate copolymers, methyl vinylether/maleic anhydride copolymers and esters thereof, uncrosslinked and polyol-crosslinked polyacrylic acids, acrylamidopropyl trimethylammonium chloride/acrylate copolymers, octylacrylamide/methyl methacrylate/tert.-butylaminoethyl methacrylate/2-hydroxypropyl methacrylate copolymers, polyvinyl pyrrolidone, vinyl pyrrolidone/vinyl acetate copolymers, vinyl pyrrolidone/dimethylaminoethyl methacrylate/vinyl caprolactam terpolymers and optionally derivatized cellulose ethers and silicones.
Suitable silicone compounds are, for example, dimethyl polysiloxanes, methylphenyl polysiloxanes, cyclic silicones and amino-, fatty acid-, alcohol-, polyether-, epoxy-, fluorine-, glycoside- and/or alkyl-modified silicone compounds which may be both liquid and resin-like at room temperature. In addition, a detailed review of suitable liquid silicones was published by Todd et al. in Cosm. Toil. 91, 27 (1976).
Typical examples of fats are glycerides while suitable waxes are inter alia beeswax, carnauba wax, candelilla wax, montan wax, paraffin wax, hydrogenated castor oils, fatty acid esters solid at room temperature or microwaxes optionally in combination with hydrophilic waxes, for example cetyl stearyl alcohol or partial glycerides. Metal salts of fatty acids such as, for example, magnesium, aluminium and/or zinc stearate or ricinoleate may be used as stabilizers.
In the context of the invention, biogenic agents are, for example, tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, deoxyribonucleic acid, retinol, bisabolol, allantoin, phytantriol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts and vitamin complexes.
Suitable deodorizers are, for example, antiperspirants, such as aluminium chlorohydrates. These antiperspirants are colorless hygroscopic crystals which readily deliquesce in air and which accumulate when aqueous aluminium chloride solutions are concentrated by evaporation. Aluminium chlorohydrate is used for the production of perspiration-inhibiting and deodorizing formulations and probably acts by partially blocking the sweat glands through the precipitation of proteins and/or polysaccharides [cf. J. Soc. Cosm. Chem. 24, 281 (1973)]. For example, an aluminium chlorohydrate which corresponds to the formula [Al2(OH)5Cl].2.5H2O and which is particularly preferred for the purposes of the invention is commercially available under the name of Locron(copyright) from Hoechst AG of Frankfurt, FRG [cf. J. Pharm. Pharmcol. 26, 531 (1975)]. Besides the chlorohydrates, aluminium hydroxylactates and acidic aluminium/zirconium salts may also be used. Other suitable deodorizers are esterase inhibitors, preferably trialkyl citrates, such as trimethyl citrate, tripropyl citrate, triisopropyl citrate, tributyl citrate and, in particular, triethyl citrate (Hydagen(copyright) CAT, Henkel KGBA, Dxc3xcsseldorf, FRG). Esterase inhibitors inhibit enzyme activity and thus reduce odor formation. The free acid is probably released through the cleavage of the citric acid ester, reducing the pH value of the skin to such an extent that the enzymes are inhibited. Other esterase inhibitors are dicarboxylic acids and esters thereof, for example glutaric acid, glutaric acid monoethyl ester, glutaric acid diethyl ester, adipic acid, adipic acid monoethyl ester, adipic acid diethyl ester, malonic acid and malonic acid diethyl ester, hydroxycarboxylic acids and esters thereof, for example citric acid, malic acid, tartaric acid or tartaric acid diethyl ester. Antibacterial agents which influence the germ flora and destroy or inhibit the growth of perspiration-decomposing bacteria, may also be present in stick products. Examples of such antibacterial agents are chitosan, phenoxyethanol and chlorhexidine gluconate. 5-Chloro-2-(2,4-dichlorophenoxyyphenol, which is marketed under the name of Irgasan(copyright) by Ciba-Geigy of Basel, Switzerland, has also proved to be particularly effective.
In addition, hydrotropes, for example ethanol, isopropyl alcohol or polyols, may be used to improve flow behavior. Suitable polyols preferably contain 2 to 15 carbon atoms and at least two hydroxyl groups. Typical examples are
glycerol;
alkylene glycols such as, for example, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, hexylene glycol and polyethylene glycols with an average molecular weight of 100 to 1000 dalton;
technical oligoglycerol mixtures with a degree of self-condensation of 1.5 to 10 such as, for example, technical diglycerol mixtures with a diglycerol content of 40 to 50% by weight;
methylol compounds such as, in particular, trimethylol ethane, trimethylol propane, trimethylol butane, pentaerythritol and dipentaerythritol;
lower alkyl glucosides, particularly those containing 1 to 8 carbon atoms in the alkyl group, for example methyl and butyl glucoside;
sugar alcohols containing 5 to 12 carbon atoms, for example sorbitol or mannitol,
sugars containing 5 to 12 carbon atoms, for example glucose or sucrose;
aminosugars, for example glucamine.
Suitable preservatives are, for example, phenoxyethanol, formaldehyde solution, parabens, pentanediol or sorbic acid and the other classes of compounds listed in Appendix 6, Parts A and B of the Kosmetikverordnung (xe2x80x9cCosmetics Directivexe2x80x9d). Suitable pigments are finely dispersed metal oxides and salts. Examples of suitable metal oxides are, in particular, zinc oxide and titanium dioxide and also oxides of iron, zirconium, silicon, manganese, aluminium and cerium and mixtures thereof. Silicates (talcum), barium sulfate or zinc stearate may be used as salts.
Suitable perfume oils are mixtures of natural and synthetic fragrances. Natural fragrances include the extracts of blossoms (lily, lavender, rose, jasmine, neroli, ylang-ylang), stems and leaves (geranium, patchouli, petitgrain), fruits (anise, coriander, caraway, juniper), fruit peel (bergamot, lemon, orange), roots (nutmeg, angelica, celery, cardamon, costus, iris, calmus), woods (pinewood, sandalwood, guaiac wood, cedarwood, rosewood), herbs and grasses (tarragon, lemon grass, sage, thyme), needles and branches (spruce, fir, pine, dwarf pine), resins and balsams (galbanum, elemi, benzoin, myrrh, olibanum, opoponax). Animal raw materials, for example civet and beaver, may also be used. Typical synthetic perfume compounds are products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type. Examples of perfume compounds of the ester type are benzyl acetate, phenoxyethyl isobutyrate, p-tert.butyl cyclohexylacetate, linalyl acetate, dimethyl benzyl carbinyl acetate, phenyl ethyl acetate, linalyl benzoate, benzyl formate, ethylmethyl phenyl glycinate, allyl cyclohexyl propionate, styrallyl propionate and benzyl salicylate. Ethers include, for example, benzyl ethyl ether while aldehydes include, for example, the linear alkanals containing 8 to 18 carbon atoms, citral, citronellal, citronellyloxyacetaldehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal. Examples of suitable ketones are the ionones, xcex1-isomethylionone and methyl cedryl ketone. Suitable alcohols are anethol, citronellol, eugenol, isoeugenol, geraniol, linalool, phenylethyl alcohol and terpineol. The hydrocarbons mainly include the terpenes and balsams. However, it is preferred to use mixtures of different perfume compounds which, together, produce an agreeable fragrance. Other suitable perfume oils are essential oils of relatively low volatility which are mostly used as aroma components. Examples are sage oil, camomile oil, clove oil, melissa oil, mint oil, cinnamon leaf oil, lime-blossom oil, juniper berry oil, vetiver oil, olibanum oil, galbanum oil, labolanum oil and lavendin oil. The following are preferably used either individually or in the form of mixtures: bergamot oil, dihydromyrcenol, lilial, lyral, citronellol, phenylethyl alcohol, xcex1-hexylcinnamaldehyde, geraniol, benzyl acetone, cyclamen aldehyde, linalool, Boisambrene Forte, Ambroxan, indole, hedione, sandelice, citrus oil, mandarin oil, orange oil, allylamyl glycolate, cyclovertal, lavendin oil, clary oil, xcex2-damascone, geranium oil bourbon, cyclohexyl salicylate, Vertofix Coeur, Iso-E-Super, Fixolide NP, evemyl, iraldein gamma, phenylacetic acid, geranyl acetate, benzyl acetate, rose oxide, romillate, irony and floramate.
Suitable dyes are any of the substances suitable and approved for cosmetic purposes as listed, for example, in the publication xe2x80x9cKosmetische Fxc3xa4rbemittelxe2x80x9d of the Farbstoffkommission der Deutschen Forschungs-gemeinschaft, Verlag Chemie, Weinheim, 1984, pages 81 to 106. These dyes are normally used in concentrations of 0.001 to 0.1% by weight, based on the mixture as a whole.
The total percentage content of auxiliaries and additives may be from 1 to 50% by weight and is preferably from 5 to 40% by weight, based on the particular composition. The compositions may be produced by standard cold or hot methods, preferably by the phase inversion temperature method.

Syndet soap bars comprising olefin sulfonate


Novel o-nitro-o-azaarylidene dyes are provided in which the o-nitro-o-azaaryl group of the dye is joined through a methine linkage to a basic heterocyclic nucleus containing an electron donating atom. These dyes are photobleachable. The photobleachable properties of the dyes make them useful in a variety of photographic applications. For example, they can be used to provide light-sensitive elements in which images can be formed in or on a support by exposure to light to which the dye is sensitive; or to provide photobleachable halation protection in photographic, including photothermographic, elements having coated thereon a photosensitive imaging layer. The dyes are also useful in filter layers.

This invention relates to o-nitro-o-azaarylidene dyes and to elements containing a photobleachable o-nitro-o-azaarylidene dye.
The use of dyes in antihalation layers is well-known in the photographic art. These dyes have been incorporated in undercoat layers and backing layers of photographic elements as described in Carroll et al, U.S. Pat. No. 2,527,583. However, the incorporation of the dyes in this manner requires the coating of extra layers. This method also has associated with it the problem of how to remove the dye and/or modify its spectral absorption characteristics after its usefulness has ceased to exist. In one method, the antihalation dye is incorporated in a layer coated on the opposite side of the support from the picture-recording layers. This layer is then scrubbed off during processing. This method requires extra processing equipment solely for the purpose of removing the antihalation layer and presents the possibility of scratching the support material during the scrubbing operation. In another method, heat-sensitive antihalation dyes are destroyed or have their spectral absorption characteristics suitably altered by subjecting the photographic element to a sufficiently elevated temperature at some point during processing. With this method, the possibility exists of concurrently altering thermally sensitive image dyes adversely or of adversely affecting the dimensional stability of the image. It therefore is desirable to provide antihalation protection for photographic elements which avoid these difficulties.
Sturmer, Belgian Pat. No. 788,279, issued Feb. 28, 1973 describes a class of o-nitro-arylidene dyes which are photobleachable. The photobleachable property of these dyes permits their being used as antihalation dyes in photographic elements in such a way as to avoid the above-described problems associated with prior art antihalation dyes and layers. The patent additionally describes the dyes as being useful for other purposes in photographic elements such as imaging dyes, in filter layers and as desensitizers for silver halide emulsions. However, it has been found that the photodecomposition products of dyes of the above Sturmer patent tend to yield some unwanted density; i.e. they absorb radiation in some portions of the visible spectrum. While the amount of unwanted density obtained with such dyes would be acceptable for many purposes, it nevertheless would be desirable if the amount of density could be reduced or eliminated.
I have found that o-nitro-o-azaarylidene dyes are photobleachable and, hence, are useful in photographic elements in the same ways as the dyes described by Sturmer, yet the decomposition products of my dyes result in reduced amounts of unwanted density. While the reasons for this are not entirely clear, it appears that the o-nitro-o-azaarylidene dyes photodecompose in a different way than the o-nitro arylidene dyes to yield products which have less absorption in the visible region of the spectrum than do photodecomposition products of o-nitro arylidene dyes.
One aspect of my invention relates to novel photobleachable dyes. Another aspect of my invention relates to photographic elements containing these photobleachable dyes.
The dyes employed in the practice of my invention are o-nitro-o-azaarylidene dyes. As employed herein the term "o-nitro-o-azaarylidene" refers to the group formed by a methine linkage and an aromatic heterocyclic nitrogen group having a nitrogen atom in one of the positions ortho to the carbon atom to which the methine linkage is attached and having in the other ortho position a nitro-substituted carbon atom. The aromatic heterocyclic nitrogen group is joined through the methine chain linkage to a basic heterocyclic nucleus containing an electron-donating atom. The number of atoms joining the electron-donating atom and the nitro group is an even number. In a preferred form the aromatic heterocyclic nitrogen group is joined through an acyclic methine chain containing an odd number of methine groups to a basic heterocyclic nucleus of the type used in cyanine dyes. Typically, the electron-donating atom in the basic heterocyclic nucleus is a nitrogen, oxygen or sulfur atom. The aromatic heterocyclic nitrogen group can be a mono, bi or polycyclic aromatic nucleus and can contain additional nitrogen atoms. Typically, aromatic heterocyclic nuclei are pyridines, pyridazines, pyrimidines, pyrazines, quinolines, quinaldines, quinoxalines and the like.
Accordingly, one embodiment of my invention is a photobleachable o-nitro-o-azaarylidene dye in which the o-nitro-o-azaaryl group of the dye is joined through a methine linkage to a basic heterocyclic nucleus containing an electron donating atom linked to the nitro group through an even number of atoms.
In a specific preferred embodiment of my invention, the o-nitro-substituted dyes have the formula: ##STR1## wherein: (a) k represents 0 or 1;
(b) m represents 0 or 1; PA1 (c) each L represents a methine group, including substituted methine groups, (e.g., --CH.dbd., --C(CH.sub.3).dbd., etc.); PA1 (d) A represents an electron donating moiety, such as oxygen (--O--), sulfur (--S--), or ##STR2## (e) R.sub.1 represents (1) an alkyl group having from 1 to 18 carbon atoms and preferably a lower alkyl group having from 1 to 4 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, butyl, secondary-butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, octadecyl); a sulfoalkyl group, preferably sulfo lower alkyl containing from 1 to 4 carbon atoms in the alkyl moiety (e.g., .beta.-sulfoethyl, .gamma.-sulfopropyl, .gamma.-sulfobutyl, .delta.-sulfobutyl, etc.); a carboxyalkyl group, preferably a carboxy lower alkyl containing from 1 to 4 carbon atoms in the alkyl moiety (e.g., .beta.-carboxyethyl, .gamma.-carboxypropyl .delta.-carboxybutyl, etc.), a sulfatoalkyl group, preferably a sulfato lower alkyl containing from 1 to 4 carbon atoms in the alkyl moiety (e.g., .beta.-sulfatoethyl, .gamma.-sulfatopropyl, .delta.-sulfatobutyl, etc.); an alkoxyalkyl group, preferably a lower alkoxy lower alkyl containing from 1 to 4 carbon atoms in both the alkoxy and alkyl moieties (e.g., .beta.-methoxyethyl, .gamma.-methoxypropyl, .delta.-propoxybutyl, etc.); an acyloxyalkyl group, preferably an acyloxy lower alkyl containing from 1 to 4 carbon atoms in the alkyl moiety (e.g., acetyloxyethyl, propanoyloxyethyl, butanoyloxybutyl, benzoyloxyethyl, toloyloxypropyl, etc.); an alkoxycarbonylalkyl group, preferably a lower alkoxy carbonyl lower alkyl containing 1 to 4 carbon atoms in both the alkoxy and alkyl moieties (e.g., .beta.-methoxycarbonylethyl, .delta.-ethoxycarbonylbutyl, .beta.-butoxycarbonylethyl, etc.); a dialkylaminoalkylene group, preferably a di-lower alkylamino lower alkylene containing 1 to 4 carbon atoms in the alkylene and alkyl moieties (e.g., dimethylaminoethylene, diethylaminopropylene, diethylaminobutylene, etc.); a cycloaminoalkylene group, preferably cycloamino lower alkyl containing 4 to 6 atoms in the cycloamino moiety and 1 to 4 atoms in the alkyl moiety (e.g., pyrrolidinylethylene, morpholinopropylene, piperidinobutylene, pyrrolinylmethylene, etc.); (2) an alkenyl group (including a substituted alkenyl group), preferably a lower alkenyl containing 2 to 4 carbon atoms (e.g., ethenyl allyl, 1-propenyl, 1-butenyl, 2-butenyl, etc.), or (3) an aryl group (including a substituted aryl)--e.g., phenyl, naphthyl, tolyl, xylyl, halophenyl such as p-chlorophenyl, p-bromophenyl, etc., alkoxyphenyl such as methoxyphenyl, 2,4-dichlorophenyl, etc. and an aralkyl group, preferably an aryl lower alkyl containing from 1 to 4 carbon atoms in the alkyl moiety (e.g., benzyl, .beta.-phenethyl, .omega.-phenbutyl, etc.) PA1 (f) Y represents the atoms necessary to complete an azaaryl nucleus such as pyridine, pyridazine, pyrimidine, pyrazine, quinoline, quinaldine, quinoxaline, etc., including nuclei containing additional substituents, aside from the o-nitro substituent, such as nitro, halo, e.g. chloro, bromo and fluoro, lower alkoxy of 1 to 4 carbon atoms e.g. methoxy, ethoxy, butoxy, or other electron-withdrawing substituents; and PA1 (g) Z.sub.1 represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the type used in cyanine dyes containing the electron-donating moiety A which ring can contain additional hetero atoms such as oxygen, nitrogen, selenium or sulfur. The heterocyclic nucleus preferably is selected from the group consisting of a thioazole nucleus including substituted and unsubstituted benzothiazole and naphthothiazole nuclei and the like, (e.g., thiazole, 4-methylthiazole, 4-phenylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)thiazole, benzothiazole, 4-chlorobenzothiazole, 4-methylbenzothiazole, 4-methoxybenzothiazole, 4-ethoxybenzothiazole, 4-phenylbenzothiazole, 5-chlorobenzothiazole, 5-bromobenzothiazole, 5-methylbenzothiazole, 5-methoxybenzothiazole, 5-ethoxybenzothiazole, 5-phenylbenzothiazole, 6-chlorobenzothiazole, 6-bromobenzothiazole, 6-methylbenzothiazole, 6-methoxybenzothiazole, 6-ethoxybenzothiazole, 5-methoxynaphtha[2,3-d]thiazole, .beta.-naphthothiazole, .alpha.-naphthothiazole, 5-nitrobenzothiazole, 6-nitrobenzothiazole, 5-chloro-6-nitrobenzothiazole, etc.); an oxazole nucleus including substituted and unsubstituted benzoxazole and naphthoxazole nuclei and the like, (e.g., oxazole, 4-phenyloxazole, benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole, 5-bromobenzoxazole, 5-methoxybenzoxazole, 5-ethoxybenzoxazole, 5-phenylbenzoxazole, 5-methoxynaphthoxazole, 5-nitrobenzoxazole, 6-nitrobenzoxazole, 5-chloro-6-nitrobenzoxazole, etc.); a selenazole nucleus including substituted and unsubstituted benzoselenazole and naphthoselenazole nuclei and the like, (e.g., selenazole, 4-methylselenazole, 4-nitroselenazole, 4-phenylselenazole, benzoselenazole, 5-chlorobenzoselenazole, 6-chlorobenzoselenazole, naphtho[2,1-d]selenazole, 5-nitrobenzoselenazole, 6-nitrobenzoselenazole, 5-chloro-6-nitrobenzoselenazole, nitro group-substituted naphthoselenazoles, etc.); a thiazoline nucleus, (e.g., thiazoline, 4-methylthiazoline, 4-nitrothiazoline, etc.); a 2-pyridine nucleus, (e.g., 2-pyridine, 5-methyl-2-pyridine, etc.); a 4-pyridine nucleus (e.g., 4-pyridine, 3-methyl-4-pyridine, nitro group-substituted pyridines, etc.); a 3,3-dialkylindolenine nucleus (e.g., 3,3-dimethylindolenine, 3,3-diethyl-5 or 6-cyanoindolenine, 3,3-diethyl-5 or 6-nitroindolenine, 3,3-dimethyl-5 or 6-nitroindolenine, etc.); an imidazole nucleus, (e.g., imidazole, 1-alkylimidazole, benzimidazole, 1,3-dialkyl, 1,3-diaryl or 1-alkyl-3-arylimidazoles and benzimidazoles, such as 5-chloro-1,3-dialkylbenzimidazoles, 5-chloro-1,3-diarylbenzimidazoles, 5,6-dichloro-1,3-diarylbenzimidazoles, 5-methoxy-1,3-dialkylbenzimidazoles, 5-methoxy-1,3-diarylbenzimidazoles, 5-cyano-1,3-dialkylbenzimidazoles, 5-cyano-1,3-diarylbenzimidazoles, 1,3-dialkylnaphth[1,2-d]imidazole, 1,3-diarylnaphth[2,1-d]imidazole, etc.); a quinoline nucleus, (e.g., quinoline, 6-methylquinoline, 6-methoxyquinoline, 6-ethoxyquinoline, 6-chloroquinoline, 4-methoxyquinoline, 4-methylquinoline, 8-methoxyquinoline, .beta.-methylquinoline, 4-chloroquinoline, 6-nitroquinoline, etc.); an imidazo-[4,5-b]quinoxaline nucleus (as described in Brooker and Van Lare, U.S. Pat. No. 3,431,111), (e.g., imidazo[4,5-b]-quinoxaline, 1,3-dialkylimidazo[4,5-b]quinoxaline such as 1,3-diethylimidazo[4,5-b]quinoxaline, 6-chloro-1,3-diethylimidazo[4,5-b]quinoxaline, etc., 1,3-dialkenylimidazo[4,5-b]-quinoxaline such as 1,3-diallylimidazo[4,5-b]quinoxaline, 6-chloro-1,3-diallylimidazo[4,5-b]quinoxaline, etc., 1,3-diarylimidazo[4,5-b]quinoxaline such as 1,3-diphenylimidazo[4,5-b]quinoxaline, 6-chloro-1,3-diphenylimidazo[4,5-b]-quinoxaline, etc.); a 3H-pyrrolo[2,3-b]pyridine nucleus, e.g., 3,3-dialkyl-3H-pyrrolo[2,3-b]pyridine such as 3,3-dimethyl-3H-pyrrolo[2,3-b]pyridine, 3,3-diethyl-3H-pyrrolo-[2,3-b]pyridine, 1,3,3-trialkyl-3H-pyrrolo[2,3-b]pyridine such as 1,3,3-triethyl-3H-pyrrolo[2,3-b]pyridine, etc.); and a thiazolo[4,5-b]quinoline nucleus; a pyrylium (including benzopyrylium, thiapyrylium and benzothiapyrylium) nucleus; and a dithiolinium nucleus.
These dyes will hereinafter be referred to as o-nitro-substituted dyes.
The above dyes, wherein k represents O, preferably are prepared by reacting a heterocyclic salt of the formula: ##STR3## with a nitro-substituted compound having the formula: III. ##STR4## In the above formulae II and III, m, A, Z.sub.1, L and Y have the same meaning as defined above, G represents a halide such as fluoride, chloride or bromide, and X represents an acid anion (e.g., halide such as chloride, bromide, or iodide, p-toluenesulfonate, thiocyanate, sulfamate, perchlorate fluoroborate, methylsulfonate, ethylsulfonate, fluorosulfonate, 2,4-dinitrobenzenesulfonate, etc.).
In accordance with this process of preparation, nitro-substituted dyes are prepared by the nucleophilic substitution of a compound of formula II for the G substituent of the o-nitro-substituted compound of formula III. This reaction is advantageously conducted in a suitable solvent. Suitable solvents include any non-nucleophilic solvent such as acetonitrile, benzene, dimethylformamide, tetrahydrofuran, acetone, ether and the like. The quantity of solvent to provide a fluid reaction mixture, suitable from 2 to 10 weight units of solvent per weight unit of reactants.
The reaction is generally conducted at elevated temperatures to accelerate the reaction. Suitable temperatures range from about 40.degree. C. up to about 150.degree. C., although temperatures of from about 60.degree. C. to about 100.degree. C. are preferred. Most conveniently, a reaction solvent is chosen which has a boiling point at atmospheric pressure in the preferred range and the reaction is conducted at the reflux temperature of the reaction mixture.
The reaction time must be of sufficient duration to allow the reaction to go to completion. If conducted in the preferred range, the reaction is usually complete within 1 to 3 hours. The product is thereupon recovered from the reaction mixture. If acetonitrile is used as the reaction solvent, the dye is generally obtained as a crystalline product when the reaction mixture is cooled to room temperature and allowed to stand for several hours.
The above dyes wherein k represents 1 are prepared by reacting a heterocyclic ammonium salt of the formula: ##STR5## with a nitro-substituted compound having the formula: ##STR6## In the above formulas IV and V; m, A, Z.sub.1, L, Y and X have the same meaning as defined above. R.sub.2 represents a displaceable electrophilic group such as anilino, acetanilino, alkoxy, halo, mercapto and the like. Instead of utilizing a single vinylene group attached to R.sub.2 in formula IV, two or more vinylene groups can be interposed between R.sub.2 and the heterocyclic ring and the resulting dye.
The above reaction is conducted in the presence of a base-solvent combination. Preferably the bases are non-nucleophilic bases such as diisopropylethylamine, sodium hydride, butyl lithium, etc. Suitable solvents include tetrahydrofuran, dioxane, dimethyl sulfoxide, acetonitrile and the like. Reaction times and temperatures can be chosen in the same manner as for the preceeding dye preparation method.
These ortho-nitro-substituted dyes exhibit excellent photobleaching properties. That is, they are colored until exposed to electromagnetic radiation to which they are sensitive. The dyes thereupon decolorize or are bleached in such a manner that they have significantly less absorbance. These dyes photobleach both in solutions as well as in the solid state, although the rate of bleaching is generally faster when in solution form.
The relative rate of bleaching of different compounds depends on various factors such as the heterocyclic moiety containing the electron donating atom (e.g., in formula I that portion of the formula containing Z.sub.1). The rate of bleaching also depends upon the number of nitro groups on the azaaryl ring and their position relative to the methine chain.
The o-nitro-substituted dyes can be used with photographic supports and elements for several different purposes. In one form the dyes can be incorporated into a photographic support or coated onto the support in a binder and used to produce photographic images. One or more of the photobleachable dyes associated with the support are simply imagewise exposed to actinic electromagnetic radiation for a length of time sufficient to cause the amount of bleaching desired. Since the dyes bleach directly upon exposure, no processing is required in order to obtain a visible image. The images obtained can be viewed under low-intensity light or under lighting conditions not containing electromagnetic radiation to which dye or dyes are sensitive. A positive of the original image is obtained.
When the photograph is viewed under normal lighting conditions, the background areas initially protected from exposure will be bleached unless special precautions are taken. Since the intensity of normal indoor room lighting is generally much lower than the intensity of the exposing light, the image can be viewed for several minutes or more without significant degradation of quality. If it is later desired that the image be obliterated, this can be easily accomplished by blanket exposure to electromagnetic radiation until the image is no longer visible. Because of the nonstable properties of the photograph obtained, it can be used as a proof image. If a permanent record of the proof is desired, it can be photographically copied using conventional photographic materials.
Preferably, instead of relying upon the o-nitro-substituted dyes to produce images, they can be incorporated into a photographic element and employed for the antihalation protection of a separate light-sensitive imaging material. The dyes can be incorporated in the support for the element, in a separate layer between the support and the layer containing the light sensitive imaging material, or in a separate layer on the opposite side from the light sensitive layer. Additionally, the dyes can be dispersed within a light-sensitive imaging layer to reduce light scattering within the imaging layer and thereby contribute to the formation of sharper images--i.e., provide antihalation protection internally of the imaging layer.
Accordingly, one embodiment of my invention is a photographic element comprising a support, a light sensitive layer and incorporated in the support, in the light sensitive layer or in a separate layer adjacent to the support, a photobleachable o-nitro-o-azaarylidene dye in which the o-nitro-o-azaaryl group of the dye is joined through a methine linkage to a basic heterocyclic group containing an electron donating atom linked to the nitro group through an even number of atoms. In a specific embodiment the o-nitro dyes are used as antihalation dyes in photographic elements.
Inasmuch as the photobleachable o-nitro-substituted dyes provide antihalation protection by physical means, i.e. absorption of light, the nature of the light sensitive layer is not significant and any light sensitive materials which would benefit from antihalation protection could be used in the photographic elements of this invention. Preferably, the light sensitive layer contains photosensitive silver halide.
Since the optical density attributable to the dyes is readily decreased by exposure to light, there is no need to remove the dye after imagewise exposure of the light sensitive layer, as is typical of conventional antihalation materials. Further, by using the o-nitro-substituted dyes for antihalation protection, the difficulties of contamination of processing solutions or the use of separate processing steps required for antihalation layer removal can be avoided. It is to be recognized that in antihalation and filter layer applications the dye is not required to bleach on imagewise exposure. Rather the o-nitro-substituted dye can be primarily bleached after processing of the photographic element, if desired. For most applications the dyes are sufficiently bleached merely by allowing the exposed and processed photograph to remain uniformly exposed to ambient room light. It is, of course, recognized that the dyes can be quickly bleached by uniform exposure to actinic electromagnetic radiation at a higher intensity than ambient room light.
While the o-nitro-substituted dyes can be employed for antihalation and filtering with a variety of conventional photographic imaging layers, these dyes are particularly advantageous when employed in combination with photothermographic imaging layers. As is well appreciated by those skilled in the art, photothermographic elements are processed by heating to elevated temperatures, typically within the temperature range of from 80.degree. to 170.degree. C. The o-nitro-substituted dyes are well suited for use in photothermographic elements, since they surprisingly possess a high level of thermal stability, yet are readily photobleachable. The thermal stability of the o-nitro-substituted dyes is, of course, also advantageous in applications where it is desired to incorporate the dye into a melt from which the support is to be fabricated.
In still another application, when the o-nitro-substituted dyes are chosen to be adsorbed by silver halide crystals, they can be incorporated into a silver halide emulsion for the purpose of desensitizing the emulsion. This is particularly advantageous where it is desired to provide an emulsion that can be handled under safelight or ambient lighting conditions with retention of sensitivity to more intense or different wavelength radiation--e.g., X-ray radiation. Those o-nitro-substituted dyes which are not readily adsorbed by silver halide crystals are useful in silver halide emulsions as light absorbing (internal antihalation) dyes.
In a simple form the present invention is directed to a photographic support incorporating therein an o-nitro-substituted dye. In order to use the dyes for imaging or antihalation protection when incorporated within the support it is necessary that the support be transparent (and it is usually preferred that the support be substantially colorless) except for the dye present. A variety of conventional transparent photographic film supports are known to the art in which the o-nitro-substituted dyes can be incorporated. These supports can be broadly categorized for purposes of this discussion into those that can be solvent cast and those that are formed from a melt. The o-nitro-substituted dyes of this invention can be dissolved in nonionic solvents such as toluene, acetone, dichloromethane, dioxane, dimethylformamide, and the like. To incorporate the o-nitro-substituted dye into a solvent cast film support, such as a cellulosic support--e.g., cellulose nitrate, cellulose diacetate, cellulose triacetate, etc.--it is merely necessary to dissolve the support forming material and the dye in a common solvent system. The o-nitro-substituted dye can be incorporated into melt formed polymer film supports merely by dispersing the dye within the molten polymer. Since the o-nitro-substituted dyes possess a surprising degree of thermal stability they can be incorporated into melt formed film support materials such as polyalkylenes (e.g., polyethylene), polystyrene, terephthalic acid polyesters such as poly(ethylene terephthalate), polycarbonates and other, lower melting resinous polymers useful in forming film supports. It is generally preferred that the dyes be substantially homogeneously dispersed within the film support so as to exhibit uniform optical density upon viewing the support. This can be readily achieved by thoroughly mixing the dye with the support material using procedures well known in the art.
As is well understood by those skilled in the art very small quantities of antihalation dyes are incorporated in nominally transparent film supports for the purpose of minimizing halation due to laterally transmitted light. Accordingly, the dyes of the present invention will provide some degree of antihalation even when incorporated in quantities too low to be visually detected. However, for most antihalation applications it is preferred that the dyes be incorporated into the support in a concentration sufficient to provide an optical density of at least 0.5, most preferably at least 1.0, before photobleaching. For imaging applications the dye is incorporated in a concentration sufficient to yield an optical density differential between image and background areas of at least 0.05. However, for most imaging applications it is preferred that an optical density differential of at least 0.20 be obtainable and, most preferably, an optical density differential in excess of 0.50.
Where the o-nitro-substituted dye is coated onto a support rather than being incorporated therein, it is, of course, possible to employ any conventional photographic support. The support can be opaque or transparent. The support can take any one of a variety of diverse forms, such as a glass, metal, film, wood, paper or composite (e.g., resin coated paper) support. Where the dye is employed for imaging it is preferred that the dye be chosen to offer a visual contrast in hue or density with respect to the support. To immobilize spatially the dye on the support it is generally prferred that it be incorporated within a transparent binder. In one form the binder with the dye dispersed therein can be identical to the support compositions with the dye incorporated therein as previously discussed. The dye can also be incorporated into any conventional photographic vehicle. Generally any conventional transparent binder can be used. The binder layer containing the dye can be located directly on the support or can be separated by one or more undercoats provided for the purpose of improving adhesion to the support. Suitable conventional photographic vehicles useful as binders and layer arrangements are described in Product Licensing Index, Vol. 92, December 1971, publication 9232, page 108, paragraph VIII, here incorporated by reference. (Product Licensing Index is published by Industrial Opportunities, Ltd., Homewell Havant, Hampshire PO9 1EF, U.K.) Generally, the dye concentration in the binder layer is chosen to provide optical densities similar to those set forth above for dyes incorporated in the support. Optically homogeneous dispersion of the dye in the binder is preferred. This can be achieved by techniques well known to those skilled in the art.
One method which has been found to yield satisfactory results is to prepare a 5 to 10 percent by weight solution of the binding agent in a satisfactory solvent and to saturate the solution with the o-nitro-substituted dye. Generally any solvent which exhibits good solvent action for the binding agent is suitable. However, lower molecular-weight solvents having relatively high volatility such as acetone, methyl ethyl ketone, methanol, ethanol, ethyl acetate, butyl acetate and the like are particularly useful. When binding agents such as gelatin are used which are normally dissolved in water, it may be necessary to dissolve the dye in another solvent and disperse the dye solution in the binding agent solution to form an emulsion. Instead of being dissolved or emulsified in the binder the dye can be finely comminuted to minimize graininess, preferably to average particle sizes of less than 5 microns, most preferably below 1 micron, and simply uniformly dispersed in the binder of agent solution.
The dye blended in the binder or binding agent solution is coated on the support to form the photographic element. Coating can be accomplished by various coating procedures including dip-coating, air-knife coating, curtain-coating, doctor-blade coating or extrusion coating using hoppers of the type described in Beguin, U.S. Pat. No. 2,681,294. If desired, two or more layers may be coated simultaneously by the procedures described in Russell, U.S. Pat. No. 2,761,791, and Wynn, British Pat. No. 837,095. The coverage at which the dispersion is coated on the support can vary widely depending upon the properties of the particular blend and the results to be achieved. For example, satisfactory results are generally obtained when a 5 to 10 percent by weight solution of the binding agent saturated with dye is coated. Wet coated thicknesses of 2 to 100 microns are generally preferred for imaging applications with coatings of like thicknesses or considerably less being useful for antihalation applications.
Where the o-nitro-substituted dyes are to be employed for imaging, it is unnecessary that any other radiation-responsive material be present. In a simple form then a photographic element useful for producing an image can consist of only the support with the dye incorporated therein or incorporated thereon in a binder layer. An image is formed merely by exposing the o-nitro-substituted dye to actinic electromagnetic radiation. Additional dye, addenda, layers and structural features can be associated with the photographic element which are not incompatible with the intended imaging application.
The electromagnetic radiation to which the dyes are sensitive varies with each particular dye and ranges from the long-wavelength ultraviolet region and into the infrared region, but usually falls in the visible region. Generally speaking, suitable imaging exposures can be accomplished with a tungsten light source. Exposure time depends upon the intensity of the source.
To use the o-nitro-substituted dyes for antihalation protection it is merely necessary to have at least one other radiation-sensitive layer associated with the support. Where the o-nitro-substituted dye is incorporated in a binder layer, this layer can be overcoated with the additional radiation-sensitive layer. Alternatively, the binder layer can be located on the opposite face of the support from the additional radiation-sensitive layer. It is merely necessary that the o-nitro-substituted dye be capable of absorbing radiation of a wavelength capable of exposing the additional radiation-sensitive layer in order for the dye to provide effective antihalation protection.
Where it is desired to employ the dyes for filtering, the o-nitro-substituted dyes can be used in a separate layer similar or identical to the antihalation layer described above, but with the difference that the filter layer overlies at least one other radiation-sensitive layer. Where a plurality of radiation-sensitive imaging elements are employed, as in color photography, the filter layer can be advantageously located between adjacent radiation-sensitive imaging layers. As is well understood by those skilled in the art, the optical density and spectral absorption of the dye in the filter layer can be varied widely, depending upon the particular choice of radiation-sensitive imaging layers and photographic effects desired. Typically the o-nitro-substituted dyes are employed for filtering purposes in concentrations sufficient to yield optical densities of 3.0 or less, most typically from 0.5 to 2.0. The photobleaching and thermal stability characteristics of the o-nitro-substituted dyes are advantageous in filter layers similarly as in antihalation layers.
While the additional radiation-sensitive layer can take any one of a variety of conventional forms, it is particularly contemplated to employ the o-nitro-substituted dyes for antihalation protection and for filtering with silver halide emulsion coatings. It is further considered particularly advantageous to utilize the o-nitro-substituted dyes for antihalation and filtering in photothermographic elements.
The described o-nitro-substituted dyes are useful in a variety of photothermographic elements.
Exemplary photothermographic elements are described, for instance, in U.S. Pat. No. 3,672,904 of deMauriac, issued June 27, 1972; Belgian Pat. No. 802,519, issued Jan. 18, 1974; U.S. Pat. No. 3,457,075 of Morgan et al, issued July 22, 1969; U.S. Pat. No. 3,409,438 of Lokken, issued Nov. 5, 1968 and U.S. Reissue Pat. No. 26,719 of Sorensen et al, issued Nov. 18, 1969; U.S. Pat. No. 3,392,020 of Yutzy et al, issued July 9, 1968; U.S. Pat. No. 3,645,739 of Ohkubo, issued Feb. 29, 1972; Belgian Pat. No. 765,452, issued May 28, 1971; U.S. Pat. No. 3,152,903 of Shepard et al, issued Oct. 13, 1964; U.S. Pat. No. 3,589,901 of Lyons, issued June 29, 1971; U.S. Pat. No. 3,589,903, issued June 29, 1971; U.S. Pat. No. 3,764,328 of Birkeland, issued Oct. 9, 1973; and U.S. Pat. No. 3,764,329 of Lee, issued Oct. 9, 1973.
Other exemplary photothermographic elements in which the described o-nitro-substituted dyes are useful are described in U.S. Pat. No. 3,506,444 of Haist et al, issued Apr. 14, 1970; Belgian Pat. No. 799,262, issued Nov. 8, 1973; and Belgian Pat. No. 766,590, issued June 15, 1971.
It is specifically recognized that the o-nitro-substituted dyes of this invention can be used as an absorber dye directly within a radiation-sensitive layer to prevent radiation scattering within this layer. By absorbing scattered radiation sharper images are obtained. It is specifically contemplated to incorporate the o-nitro-substituted dyes in silver halide emulsions to act as absorber dyes. Since the o-nitro-substituted dyes can be photobleached after the photographic element is fully processed, the concentration of the o-nitro-substituted dye is typically limited only by the reduction in speed that can be tolerated for the radiation-sensitive layer. Very low levels of incorporated o-nitro-substituted dye will produce a significant increase in sharpness, since a significant component of scattered radiation moves laterally. For most applicantions it is preferred to incorporate from 0.01 to 0.40 gram of o-nitro-substituted dye per gram of silver halide present in the radiation-sensitive layer. The dye is, of course, chosen to absorb radiation of a wavelength to which the radiation-sensitive layer is responsive.
In addition to acting as an absorbing dye which provides internal antihalation protection to a radiation-sensitive layer the o-nitro-substituted dye can also act as a desensitizer for silver halide emulsions. It is preferred to employ those o-nitro-substituted dyes of this invention as absorber dyes in silver halide emulsions which are less readily or totally unadsorbed by silver halide crystals and to employ those remaining dyes which are more readily adsorbed by silver halide crystals as desensitizers.
As used herein, "a desensitizer" for a photographic silver halide emulsion refers to a dye which, when added to a gelatinous silver bromoiodide emulsion containing 2.5 mole percent iodide (based on total silver halide) at a concentration of from 0.01 to 0.4 gram of dye per mole of silver halide, causes a loss in the blue speed of the emulsion when sensitometrically exposed and developed for 6 minutes in an Elon-hydroquinone developer at room temperature. Preferred desensitizers are those which, when tested as just described, cause a loss of at least 50 percent and preferably 90 percent or more of speed to blue radiation.
The o-nitro-substituted dyes can be incorporated into radiation-sensitive layers, such as silver halide emulsion coatings, by techniques well known to those skilled in the art. For example, to prepare a gelatino-silver halide emulsion incorporating the o-nitro-substituted dye, a quantity of the dye is dissolved in methyl alcohol or other suitable solvent, and this solution (which can be diluted with water) containing the dye is slowly added to 1000 cc of a gelatino-silver halide emulsion with stirring. It is, of course, desired to substantially uniformly disperse the dye within the radiation-sensitive layer, so that localized variations in coating response are minimized. The radiation-sensitive layers and the silver halide emulsion layers specifically can take any desired conventional form, and it is specifically contemplated to employ the o-nitro-substituted dyes in multilayer elements, such as those typically employed to form conventional color photographs. Typical emulsions, addenda, coatings and coating combinations contemplated for use with the o-nitro-substituted dyes are illustrated by those disclosed in Product Licensing Index, Vol. 92, December 1971, publication 9232, pages 107 through 110, (Product Licensing Index is published by Industrial Opportunities, Ltd., Homewell Havant, Hampshire PO9 1EF, U.K.), the disclosure of which is here incorporated by reference.

O-Nitro-o-azaarylidene photobleachable dyes and photographic elements utilizing them


A reading card is provided including at least one reading lens which is smaller in size than the card member and is carried thereby. The card member has the size of a typical credit card such that it can be readily fit into the sleeve or holder used for these cards in wallets, and the like. Preferably, the lens is of a material and configuration so that it is provided with a well-defined or sharp diopter rating to allow a user to select among reading cards each with different diopter lenses for their particular needs. The lenses are carried by the card member so that additional space is left thereon for placement of, for example, indicia and a magnetic strip such as in credit, debit, and phone cards.

The invention relates to cards and, more particularly, to cards that provide a viewing enhancement function.
Cards that people carry about in their wallets or purses issued by financial, retail and other consumer-orientated businesses for transmitting information relating to an individual carrying the card have become ubiquitous for enabling efficient transactions to occur in all sorts of daily applications. Credit cards are perhaps the most common type of such cards which allow purchases to be made without the need to pay cash for the items charged to the card. Similarly, debit cards and telephone cards allow consumers to use the cards in lieu of money to pay for items or calls, respectively, by drawing down the money deposited to a specified account tied to the card. In all of these cards, there is typically information encoded such as on a magnetic strip of the card relating to the identity of the card owner and/or which allows the status of the account associated with the card to be determined.
With telephone cards, public transportation or train cards, etc. the holder can add value to the card by feeding the card into a machine that accepts money and adds the indicated amount to the card. The holder of the card uses it by running the card through the card reader that detects the amount added to the card as encoded on the magnetic strip and deducts the amount needed to effect the transaction for which it is being used. One problem noted with these cards is that once the holder uses up the amount they have added to the card, typically rather than retaining the so called xe2x80x9cemptyxe2x80x9d card for future use by adding money thereto as described, they simply discard the empty card and obtain a new one when needed and add the money to the new card at the time it is obtained and thereafter as is convenient. Accordingly, this raises cost to the card issuer as they need to increase the number of cards they produce to satisfy this need created by those who do not retain their cards when the value added thereto has been exhausted.
With a great many of cards, there generally is paperwork that is generated by their use. For example, with use of credit cards, an invoice is created that has to be read and signed by the user. Where the credit card is used in a restaurant, the amount is of particular importance as that determines the tip for the service provider that has to be calculated. Another example is prescription cards that are provided to the pharmacist for example, before a prescription is filled. In this instance, the label on the bottle indicates the type of medicine contained therein, the dosage and frequency at which the medicine is to be used, and various warnings regarding its use. These labels are typically fairly small with associated small print thereon to fit on the small bottles. Because the patients obtaining prescriptions are often elderly people, the prescription labels are usually very difficult to read without use of reading glasses. Other examples of where cards are employed in a context where reading can become important is with telephone cards where the user may need to refer to a telephone book and a vehicle warranty card provided with a vehicle owners manual.
The typical pair of eyeglasses are usually provided with a soft or hard case so that they can be carried about when not in use. Where people need glasses for reading or do not like to wear their glasses all the time, the cases are an important accessory as they protect them from damage. One problem with these cases is in their size as they have to be large enough to accommodate the glasses with their temple arms folded against the lenses. Thus, the cases are slightly larger than the size of a standard folded-up pair of reading glasses. The size of the cases does not permit them to be readily fit into most pockets on clothing. Accordingly, absent some sort of carrying bag or pouch for holding the case, eyeglasses that are used only periodically such as for reading, are usually left at home and thus, not otherwise available for their owners. Thus, despite the need, many card holders do not have reading glasses with them when needed such as in conjunction with use of their cards, as described above.
A Fresnel lens has been provided in the shape of long bookmarks having a length of approximately seven and a half inches as well as in the shape of rectangular cards of the credit card type size. The Fresnel lenses in these relatively large forms are a flat, thin piece of plastic material in which a series of small concentric stepped grooves are formed to produce raised prism ridges in the plastic material. Fresnel lenses are not particularly well suited for viewing enhancement such as for reading print like the typical lens used with reading glasses. Instead, Fresnel lenses are typically used in applications where magnification is the most important consideration over all others. In this regard, Fresnel lenses as reading lenses are typically not used because of their poor optics in terms of resolution creating blurring or distorted vision in their use. In this regard, the diopter rating for Fresnel lenses is not very well defined and can vary somewhere in the range of four to six, which generally is several orders beyond that needed for reading lenses. Another drawback of the high-power magnification provided by Fresnel lenses is that the focal length and field of view of the lens is not as desirable as it is with a typical lens for reading. With high-powered Fresnel lenses not only is resolution poor, but the lens needs to be held further from the eyes for proper focus and the high magnification and diopter rating they provide decreases the field of view beyond that which is desired when reading. Also, Fresnel lenses usually are formed of a relatively soft, plastic material such as PVC that can readily be pressed for forming the requisite ridges of the Fresnel lens. The soft plastic material renders Fresnel lenses particularly deficient as reading lenses as from a practical standpoint, these types of lenses are handled frequently and when they are formed with a soft plastic material will tend to more easily be scratched or marred as a result thereof.
Accordingly, there is a need for a card that allows for the reading of materials generally associated therewith without the need for a separate pair of reading glasses to be available. More particularly, a card that allows the owner to use the card for reading much in the manner of a pair of reading glasses would be desired.
In accordance with the present invention, a reading card is provided that has a size akin to that of a credit card and can be fit in a sleeve or holder that is incorporated into a wallet. In this manner, a separate pair of reading glasses and case therefor are not needed to provide precision viewing enhancement for a user. Instead, the present reading card can be carried in a space savings manner in a cardholder""s wallet and when removed therefrom can be used for transactions, identification purposes and the like while also providing the holder with precision viewing enhancement. More particularly, the reading card has at least one reading lens which is smaller in size than the card member and is carried thereby and preferably has a configuration to provide it with a well-defined diopter rating so that the card can be adapted to a user""s specific reading needs based on their eyesight deficiency, unlike the poor optics provided by Fresnel lenses.
A low-profile or surface mount light or LED can also be incorporated in the reading card so that the viewing area can be illuminated for enhanced reading, particularly in dimly lit locations. Other features incorporated into the present reading card can include a low-profile voice recorder/playback device and calculator features including low-profile keys and a display. All of these added electronic features do not add significantly to the size, and in particular the thickness of the present card thus adding significant value to the card while also keeping its compact size for carrying purposes. Where the card is used by paying to add cash value to the card, the reading lens and above-described electronic features will increase the likelihood that the holder will not discard the card when empty thus reducing costs to card issuers. Magnets can be attached to the card to allow the card to be placed on a metallic support surface, e.g. refrigerator door, when not in use.