Aluminium-based polymer material and use of this material in a photographic product

Abstract: The invention concerns an inorganic aluminium-based polymer and another element chosen from amongst silicon, titanium and zirconium. The polymer material is obtained from hydrolisable salts and/or compounds such as alkoxydes. Application to the production of ancillary layers in photographic products.

Description: The present invention concerns a novel polymer material comprising a gel constituent based on aluminium and another element chosen from titanium, zirconium or tin, and the use of this material to produce layers able to be used for a photographic product. International patent application WO 96/13459, entitled "Polymer silico-aluminate and method of preparing it" describes a material with a fibrous structure and anti-static properties. The object of the present invention is an inorganic polymeric material similar to the material of the aforementioned PCT application, but in which all or part of the silicon has been replaced by an element chosen from the class consisting of titanium, zirconium or tin. According to one embodiment, the said element has another element added to it. In the present description and in the claims which accompany it, the inorganic polymer material will be referred to as polymer alumino-metallate. Another object of the present invention is a photographic layer, comprising the said polymer alumino-metallate. According to one embodiment, the layer contains the polymer material and a binder. The terms "Photographic layer" refer to any layer of a photographic product, a photosensitive layer whatever the photosensitive substance, or a non-photosensitive auxiliary layer, for example, a substratum, an intermediate layer or a top layer. The polymer material according to the invention comprises a gel constituent of the formula: Al x M 1 y1 Siy 2 O z in which x represents the Al stoichiometry of the composition and varies between 0.8 and 3; M 1 is chosen from the class consisting of tin, titanium and zirconium; y 1 represents the stoichiometry of M in the composition; y 2 represents the stoichiometry of Si in the composition and can be equal to 0 x, y 1 and y 2 are such that x/y 1 + y 2 is in the range of from 0.8 and 3; z is determined by the valency of the various elements of the composition so as to obtain neutrality of charges. The percentage of constituent Al x M 1 y 1 Siy 2 Oz in the polymer alumino-metallate can be evaluated by the X-ray spectrometry technique known as "Energy Dispersive X-ray spectrometry" or EDX, or by the emission spectrometry technique known as "Inductively Coupled Plasma" or ICP. This percentage is at least 50 % molar and preferably at least 80 % molar, based on the total number of mole of Al, M 1 and Si. According to one embodiment, the metal M 1 is associated with an additional element. This additional element is preferably an element present in the intersticial lattice of the metal M 1 , in a quantity representing between 0.1 and 7% molar with respect to M 1 . This additional element can vary according to the nature of M 1 and the electrical and/or optical effects sought. If the conductive characteristics are to be maintained or improved, it is possible to use as an additional element elements from the groups Vb and Va such as Nb, Ta, Sb or halogens. Thus, examples of polymeric alumino-metallates in accordance with the invention comprise inorganic aluminium-titanium, aluminium-zirconium, aluminium-tin, aluminium-titanium-silicon, aluminium-zirconium-silicon or aluminium-tin-silicon, with the optional addition of the elements in the groups Vb and Va referred-to above. The method of preparing the polymer alumino-metallate according to the invention is identical to the method described in the aforementioned International patent application WO 96/13459, with the exception of the starting ingredients. Hydrolysable compounds of aluminium and of the chosen element M 1 are used as starting ingredients and the mixture is hydrolysed at a controlled pH. The product obtained is then subjected to heating to a temperature below 100°C in the presence of silanol groups, and then the resulting product can be separated, for example by gelification, elimination of excess water, redissolving the gel with hydrochloric acid and purifying the solution by dialysis. As starting ingredients, use is made of salts or compounds able to be hydrolysed at a pH between 3 and 4. An excessively acidic pH, can lead to loss of anisotropy and requires soda to be added to adjust the pH. Furthermore, the excessively acidic pH causes the precipitation of silica when an alumino-metallate is prepared which also comprises silicon. A basic pH may cause the formation of metal hydroxide. Starting ingredients with appropriate reactivity comprise for example aluminium compounds such as halides, such as chloride or bromide, perhalogenates, such as perchlorate, sulphate, nitrate, sulphate or carboxylates, alkoxydes such as aluminium ethoxyde or aluminium isopropoxyde. Starting ingredients for M 1 are, for example, halides, halogeno-alcoxydes, alcoxydes, etc. One technique consists of slowly adding a pure alkoxyde or an alcoholic of an alkoxyde of M1 to an aqueous solution of aluminium halide or aluminium alkoxyde. The heating step is performed as described in the aforementioned international patent application. The alumino-metallates obtained preferably have an anisotropic structure, this means that when examined by electron microscope techniques, they appear to consist of particles with a dimension at least equal to 1.5 times each of the other two dimensions of the particle. Advantageously, according to the observation of electron microscope photographs, the particles are acicular to the point that their largest dimension is equal to at least 20 times and preferably at least 100 times each of the other two dimensions. According to one embodiment, the particles can take the form of filaments. This structure makes the alumino-metallates according to the invention suitable for forming layers, even thin ones, of the type encountered in photographic products (with a thickness between 0.5 and 10 µm); these layers, depending on the thickness, the choice of M 1 and optionally of the additional element, the choice of the binder, can be transparent and/or conductive. They also exhibit resistance to alkaline hydrolysis, which is important for a silver halide photographic product designed to be developed in an alkaline developer. The alumino-metallates according to the invention are useful to prepare photographic layers, as the sole constituent of such layers, or in admixture with a binder. It is possible to use as binders the conventional vehicles of photographic layers, for instance proteinasceous binders such as gelatines, or cellulosic binders such as hydroxy alkyl celluloses, or polyalkylene glycol binders, or vehicles in the form of a latex. The following examples illustrate the invention. EXAMPLE 1 A solution of 0.48 g (3.6 mmoles) of aluminium chloride in 1500 ml of water purified by osmosis is introduced into a glass reactor. 0.44 g (2.1 mmoles) of TiCl 2 (OEt) 2 is added. The solution is stirred vigorously and an opalescent mixture is obtained whose pH is 3.61. The pH is adjusted to 5 with NaOH 1N and then, after 5 minutes, to 4.35 with a mixture of HCL 1N and acetic acid 2N. The mixture is then heated to a temperature between 80 and 98°C for 120 hours. It is left to cool. The pH of the mixture is 3.75. A solution of ammonia is added slowly to adjust the pH to 8. A gel is obtained which is centrifugated for 15 mins at 2000 rpm. The gel is redissolved by adding a few drops of HCL 12N, and then the resulting solution is dialysed with osmosed water. 120 g of a thixotropic gel is collected which comprises by mole 63% aluminium and 37% titanium, for an Al/Ti ratio by weight of 0.82 as determined by "ICP" emission spectrometry. Microscopic examination of this gel shows that it consists of elongate particles which are comprised of assembled fibrils (Fig 1). EXAMPLE 2 Aluminium chloride hexahydrate (0.87 g; 3.6 mmoles) is introduced into a glass reactor. While stirring, 0.29 g (1.4 mmoles) of tetraethoxysilane, followed by 0.29 g (1.4 mmoles) of TiCl 2 (OEt) 2 are added dropwise. After an hour, the pH stabilises at 3.7. The pH is adjusted to 5 with NaOH 1N, and then after 5 minutes to 4.35 with a mixture of HCl 1N and acetic acid 2N. The reactor is then heated at a temperature between 80 and 98°C for 120 hours. It is left to cool to room temperature. The pH of the mixture is 3.98. The pH is adjusted to 8 using a solution of ammonia; a gel is obtained which is centrifugated for 15 mins at 2000 rpm. The gel is redissolved by adding a few drops of HCL 12N, and then the solution is dialysed with osmosed water. 120 g of a thixotropic gel is obtained which has an Al:Tl + Si ratio by weight of 0.90, as determined by ICP. Microscopic examination shows that this gel consists of particles and filaments (Fig 2). EXAMPLE 3 0.49 g (2.1 mmoles) of zirconium chloride (IV) is introduced into a glass reactor. A solution of 0.73 g (3.6 mmoles) of aluminium isopropoxyde in 1500 ml of osmosed water is then added dropwise. The mixture is stirred vigorously for 24 hours and a transparent reactional medium is obtained which has a pH of 4.63. The pH is adjusted to 5 with NaOH 1M; the medium becomes cloudy, and then the pH is re-adjusted to 4.58 with a mixture of HCL N and acetic acid 2N. A transparent solution is obtained which is heated for 120 hours at a temperature between 80 and 98°C. It is then left to cool to room temperature. The pH of the medium is 3.94. The product is coagulated and purified as in Example 1. A thixotropic gel is obtained which has an Al:Zr ratio by weight of 0.50 as determined by ICP. Microscopic examination shows that this gel consists of fibres and particles (Fig 3). EXAMPLE 4 0.29 g (1.4 mmoles) of tetraethoxysilane is added dropwise to a solution of AlCl 3 hexahydrate (0.87 g, 3.6 mmoles) in 1500 ml of osmosed water. A solution of 0.87 g (3.6 mmoles) of zirconium (IV) chloride is then added. The pH of the mixture, which is 3.43, is adjusted to 5 with NaOH 1N, and then after 5 minutes to 4.35 with a mixture of HCL 1N and acetic acid 2N. The mixture is then heated and purified as in Example 1. A thixotropic gel is obtained which has an Al:Zr + Si ratio by weight of 0.48 as determined by ICP. Examination by electron microscope (x 125,000) reveals a fibrous structure (Fig 4). EXAMPLE 5 A solution of 2.7 g (7.2 mmoles) of aluminium nitrate monohydrate in 3000 ml of osmosed water is introduced into a glass reactor. 1.1 g (4.2 mmoles) of tin (IV) chloride and then 0.038 g (0.17 mmoles) of antimony (III) chloride are added dropwise. The mixture is stirred vigorously for 24 hours. The reactional medium is yellow and slightly cloudy (pH 3.15). The pH is adjusted to 5 with NaOH 1N, and then after 5 minutes to 4.55 with a mixture of HCl 1N and acetic acid 2N. The solution is heated and the resulting gel coagulated and purified as in Example 1. A thixotropic gel is obtained which has an Al:Sn ratio by weight of 0.27 by EDX. Figure 5 shows a microscopic view of the structure of the gel. EXAMPLE 6 A solution of 0.39 g (1.5 mmoles) of tin (IV) chloride in 250 ml of osmosed water is introduced into a glass reactor. While stirring, 0.32 g (1.5 mmoles) of tetraethoxysilane in a mixture of water and ethanol (20 ml/230) is added. A solution of 0.87 g (3.6 mmoles) of aluminium chloride hexahydrate in 1000 ml of osmosed water is added. The pH of the mixture is 3.65. The pH is adjusted to 5 with NaOH 1N, and then to 4.3 with a mixture of HCl 1N and acetic acid 2N. Heating, coagulation and purification then take place as in Example 1. A thixotropic gel is obtained which has an Al:Sn + Si ratio by weight of 0.31 as determined by ICP. Figure 6 is a microscopic view of the structure of the gel. The materials prepared in Examples 1 to 6 were analysed by EDX spectrometry and by ICP emission spectrometry. The consistency of the values yielded by the EDX and ICP techniques is indicative of the homogeneity and purity of the phase corresponding to the aforementioned general formula. The values obtained are shown in the following table: Al/x or Al/(x + Si) by weight/molar Example Al/x or Al/x + Si) ratios of starting products (by weight/molar) EDX analysis ICP analysis 1 0.90/1.71 0.96/1.70 0.82/1.46 2 0.91/1.28 0.71/1.43 0.90/1.10 3 0.51/1.71 0.41/1.38 0.50/1.68 4 0.58/1.28 0.47/0.85 0.48/0.97 5 0.37/1.64 0.27/1.17 0.13/1.17 6 0.44/1.2 0.42/1.27 0.31/1.12 x - element chosen therefore M1 The closer the results of the EDX analysis are to the TEM and ICP, the purer the material obtained.

Claims: Inorganic polymer material which comprises a gel constituent and characterised in that the said gel constituent corresponds to the formula: Al x M 1 y1 Siy 2 O z in which x represents the Al stoichiometry of the compound and is in the range of from 0.8 to 3.0, M 1 is chosen from the group consisting of titanium, zirconium and tin; y 1 represents the stoichiometry of M 1 ; y 2 represents the stoichiometry of Si and can be equal to 0; x, y 1 and y 2 are such that x/y 1 + y 2 is in the range of from 0.8 to 3; z is determined by the valency of M 1 so as to obtain neutrality of charges. Material according to one of claims 1 or 2, characterised in that the said constituent also contains an additional element chosen from the class consisting of metals of groups Vb and Va of the periodic table. Photographic product comprising at least one layer which contains a material according to one of Claims 1 or 2. Photographic product according to Claim 3, characterised in that it contains at least one layer in which the said material is in admixture with a binder.

Inventors: PONCELET OLIVIER JEAN CHRISTIA, RIGOLA JEANNINE, PONCELET, OLIVIER JEAN CHRISTIAN, RIGOLA, JEANNINE, Poncelet, Olivier Jean Christian, Kodak Industrie, Rigola, Jeannine, Kodak Industrie
Applicants: EASTMAN KODAK CO, EASTMAN KODAK COMPANY
Application year: 1997
Main classification: C01F7
IPC codes: C01G25, C01B33, C01G19, C01G23, G03C1