JPS6247811B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing acicular tin oxide. Examples of conductive agents used in conductive layers of electrophotographic supports, energized recording media, discharge breakdown recording media, electrostatic recording media, and antistatic layers of silver salt photographic recording media include gold, silver, copper, aluminum, etc. Fine powders of metals such as nickel, iron, titanium, and tin, and fine powders of metal oxides such as zinc oxide, titanium oxide, aluminum oxide, silicon oxide, indium oxide, and tin oxide are known. For example, the use of tin oxide fine powder as a conductive layer of an electrophotographic support was disclosed in
It is disclosed in Publication No. 113224. Such a conductive agent can be said to be an electronically conductive conductive agent because the fine powder itself conducts electrons and/or holes to impart conductivity. Such electron-conductive conductive agents include, for example, ion-conductive conductive agents that impart conductivity by conducting ions such as moisture, such as inorganic salts, surfactants, organic wetting agents, and polymer electrolytes (under low humidity conditions). Unlike other conductive agents, which are highly humidity-dependent and show only low conductivity and almost no conductivity in the absence of moisture, they have the advantage of always providing constant conductivity regardless of humidity. be. Such conductive agents are usually mixed into rubber, plastic, paper, etc., or dispersed in a solution containing a binder and coated on a suitable support. In order to obtain the desired properties, the powder content must be increased so that at least adjacent powders come into close contact with each other. Therefore, it is difficult to use such fine powder to create conductive materials or conductive layers that require transparency. If a fibrous or acicular conductive material with electronic conductivity is used, it is possible to effectively form a conductive path even with a small amount of conductive material per unit area. If used, these are all colored, so they are unsuitable for cases where transparency is required or where whiteness of paper, etc. is required. In addition, in order to form a metal oxide in the form of needles or fibers without these defects, it is necessary to attach the metal oxide around a central material such as glass fiber to form a conductive material in the form of fibers or needles. Alternatively, metal oxides are attached or impregnated around fibers made of organic polymeric materials, and then the polymeric materials are removed by dissolving or incinerating to form a fibrous or acicular conductive agent. However, it is impossible to form a fibrous or acicular conductive agent with the diameter required as a conductive agent for a conductive layer, and the process is complicated and inevitably expensive. It had to become something. As a result of many years of search and research for conductive agents that satisfy the above performance, the present inventors found that when a tin compound and a sulfuric acid compound are reacted in a solution containing a specific surfactant, needle-like particles are formed. It was discovered that acicular tin oxide with high conductivity can be formed by firing tin oxalate. By incorporating such acicular tin oxide into rubber, plastic, paper, etc., or by dispersing it in a solution containing a binder and coating it on a suitable support, it can be made stable without being affected by humidity. It is clear that the amount of use per unit area can be lower than that of a powder conductive agent, and the transparency can be improved because it has high conductivity, has excellent whiteness, and is easy to create a conductive path. An object of the present invention is to provide acicular tin oxide that can form a conductive layer with excellent whiteness and transparency. Another object of the present invention is to provide a method for producing acicular tin oxide. That is, the present invention provides a method for producing tin oxide, which is characterized in that tin oxide is formed by reacting a tin compound with a sulfuric acid compound in a solution containing a nonionic surfactant, and then thermally decomposed to obtain tin oxide. It's a method. The present invention will be explained in more detail below. First, a method for forming acicular tin oxalate for obtaining the acicular tin oxide of the present invention will be described. Acicular tin oxalate is formed by reacting a tin compound and an oxalate compound in a solution containing a specific surfactant, but the surfactant used here is a nonionic surfactant. In particular, glycerin esters of higher fatty acids, glycol esters of higher fatty acids, pentaerythritol esters of higher fatty acids, sucrose esters of higher fatty acids, sorbitan and mannitutan esters of higher fatty acids, higher alcohol condensates, higher fatty acid condensates,
Nonionic surfactants typified by higher fatty acid amide condensates, higher alkyl amine condensates, higher alkyl mercaptan condensates, alkyl phenol condensates, polypropylene oxide condensates, and the like are preferred. Among them, the hydrophilic/lipophilic balance defined by JTDavis described on page 66 of "New Surfactants" (written by Hiroshi Horiguchi, published by Sankyo Publishing Co., Ltd., October 10, 1975). It is particularly preferable to synthesize tin oxalate by containing 0.01 to 10% by weight of a compound having a (HLB) of 7 to 20 in the synthesis solvent. HLB is calculated according to the following formula, for example. HLB = Hydrophilic group - Hydrophobic group + 7 The following numerical values are shown as the number of HLB groups for each atomic group of hydrophilic and hydrophobic groups.

[Emulsion layer approx. 5μ]

Binder: Gelatin 2.5 g/cm ² Coated silver material: 5 g/m ² Silver halide composition: AgI 1.5 mol% and AgBr 98.5 mol% Hardener: 2.4 dichloro-6-hydroxy-1,
3,5-triazine sodium salt, 0.4g/100
g Gelatin fog inhibitor: 1-phenyl-5-mercaptotetrazole 0.5 g/Ag 100 g [protective layer approx. 1μ] Binder: gelatin 1.7 g/m ² and potassium polystyrene sulfonate (average molecular weight approx. 7)
0.3g/ ^m2 Coating agent: N-oleyl-N-methyltaurine sodium salt 7mg/ ^m2

Claims (1)

[Claims] 1. A method for producing tin oxide, which comprises reacting a tin compound and a sulfuric acid compound in a solution containing a nonionic surfactant to form tin sulfuric acid, followed by thermal decomposition to obtain tin oxide.