Abstract: The present invention provides a new method of purifying a high HLB sugar fatty acid ester without using any solvent and giving it as a powdery form, in which a crude sugar ester is neutralized in pH value, and added with water, a neutral salt and sugar to give a sediment; this sediment is washed with acidic water; the washed water containing the high HLB sugar fatty acid ester at higher concentration is added with a fatty acid to separate a deposition; and this deposition is neutralized and spray dried.

Abstract: A process for recovering, in a purified form, sucrose fatty acid esters having a high HLB included in a reaction mixture formed by a reaction of sucrose and a fatty acid alkyl ester in an organic solvent as reaction medium in the presence of a catalyst, which comprises adjusting the reaction mixture from which a part of the organic solvent may be previously removed and to which water is added to form an aqueous solution, to a neutral pH region, adding a neutral salt and sucrose to the solution to precipitate the sucrose fatty acid esters, separating and washing the precipitate with an acidic water, and subjecting the washing liquid to ultrafiltration. The concentrate obtained by ultrafiltration may be spray-dried to form a dry powder of the sucrose esters having high HLB, and the liquid obtained by separating the precipitate may be contacted with a reverse osmosis membrane to recover sucrose.

Abstract: A process for purifying sucrose fatty acid esters included in a reaction mixture formed by a reaction of sucrose and a fatty acid alkyl ester in an organic solvent as reaction medium in the presence of a catalyst, which comprises adjusting the reaction mixture from which a part of the organic solvent as reaction medium may be previously removed and to which water is added to form an aqueous solution, to a neutral pH region, adding a neutral salt and sucrose to the solution to precipitate the sucrose fatty acid ester, filtering off the precipitate, and washing the precipitate with an acidic water. The washed precipitate in the form of slurry is spray-dried to form a dry powder, and the filtrate is contacted with a reverse osmosis membrane to recover sucrose. According to the invention, purified sucrose fatty acid esters can be obtained from the reaction mixture without using an organic solvent as purification solvent, while sucrose can be recovered in high yield.

Abstract: From a reaction mixture obtained by reaction of sucrose and a fatty acid alkyl ester in the presence of a catalyst, a purified sucrose fatty acid ester is prepared without using organic solvents for purification by adding water to the reaction mixture and subjecting the resulting aqueous solution to ultrafiltration, thereby removing the unreacted sucrose, the catalyst or a salt derived from the catalyst, and the volatile component used as the reaction medium together with water. A powder of the purified sucrose fatty acid ester is easily, economically and safely prepared by subjecting the aqueous solution remaining in the ultrafiltration to reverse osmosis and spray-drying the resulting concentrate.

Abstract: A process for preparing sucrose fatty acid esters by reacting sucrose and a fatty acid alkyl ester in an aqueous reaction system in the presence of a catalyst, adding water to the reaction mixture to dissolve it, adjusting the reaction mixture to a neutral ph region, adding a neutral salt to the solution to precipitate the sucrose fatty acid esters, separating and washing the precipitate with an acidic water, and subjecting the washing liquid to ultrafiltration. The precipitate washed with the acidic water is spray-dried in the form of an aqueous slurry to give a dry powder of the sucrose esters having low HLB, and the concentrate obtained by ultrafiltration is spray-dried to form a dry powder of the sucrose esters having high HLB, and the liquid obtained by separating the precipitate is contacted with a reverse osmosis membrane to recover sucrose. According to the invention, purifed sucrose fatty acid esters can be obtained without using an organic solvent, while sucrose can be recovered in high yield.

Abstract: A process for recovering unreacted sucrose from a reaction mixture of sucrose and a fatty acid alkyl ester in an organic solvent as reaction medium in the presence of a catalyst in the production of a sucrose fatty acid ester which comprises adjusting the reaction mixture from which a part of the organic solvent as reaction medium may be previously removed and to which water is added, to a neutral pH region, adding a neutral salt and sucrose to the reaction mixture to precipitate the sucrose fatty acid ester, filtering off the precipitate, and bringing the filtrate into contact with a reverse osmosis membrane to recover the unreacted sucrose. According to the invention, unreacted sucrose can be easily recovered, while the sucrose fatty acid ester not contaminated with the organic solvent as reaction medium can be obtained from the reaction mixture without using an organic solvent for purification.

Abstract: A process for preparing particulate water-soluble cationic acrylic polymers having a high molecular weight, an excellent water solubility and a uniform particle size with a good productivity by adding a combined photoinitiator system of an azoguanyl compound and other usual photoinitiator to an aqueous monomer solution containing a cationic vinyl monomer, irradiating the aqueous monomer solution in the form of a thin layer on a moving support with ultraviolet rays in at least two stages, and finely dividing the produced aqueous polymer gel in a wet state by a roller cutter and then by a vertical cutter.