Organic sol and solid compound based on titanium oxide and amphiphilic compound and preparation methods

Process for the preparation of an organic sol, comprising:

• titanium oxide particles;
• an organic liquid phase;
• at least one amphiphilic compound having a formulae:
• wherein,
• R1, R2, and R3 are a linear or branched alkyl group, a phenyl group, an alkylaryl group or an arylalkyl group;
• n represents the number of ethylene oxide units and wherein n is from two to twelve;
• and
• M1 represents a hydrogen, sodium or potassium atom, the process comprising the following steps:
• a) preparing, as starting product, titanium dioxide particles by hydrolysis of at least one titanium compound A in the presence of at least one compound B selected from the group consisting of:
• (i) acids which have:
• either a carboxyl group and at least two hydroxyl and/or amine groups,
• or at least two carboxyl groups and at least one hydroxyl and/or amine group,
• (ii) organic phosphoric acids of the following formulas:
• in which n1 and m are integers between 1 and 6, p is an integer between 0 and 5, R4, R5 and R6 identical or different represent a hydroxyl, amino, aralkyl, aryl, alkyl group or hydrogen group,
• (iii) compounds capable of releasing sulphate ions in an acid medium,
• (iv) salts of the acids described above and in the presence of anatase titanium dioxide seeds;
• b) optionally at least partially covering the particles by a layer of at least one of a silicon oxide, hydroxide or oxyhydroxide or a metallic oxide, hydroxide or oxyhydroxide;
• and
• c) mixing the amphiphilic compound and the organic liquid phase together, then dispersing the titanium oxide particles in the mixture obtained, or forming a mixture of titanium oxide particles and at least one of the aforementioned amphiphilic compounds, then dispersing said mixture in the liquid phase.