WASTELESS METHOD OF OBTAINING POLYMETHYLENE NAPHTHALENE SULPHONATES WITH REGULATED LOW CONTENT OF SODIUM SULPHATE Russian patent published in 2014 - IPC C07C317/14 C08G75/24 C04B24/22 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining polymethylene naphthalene sulphonates (PNS) with a regulated low content of sodium sulphate, which includes sulphonation of a naphthalene-containing raw material with a sulphonating agent under conditions of the forced discharge of a steam-gas mixture of a balanced composition to a degree of action of sulphuric acid 1.5-4% counted per residual sulphuric acid, with the regulation of naphthalene and water content in the steam-gas mixture and a quantity of the discharged steam-gas mixture in total being carried out by a step-by-step creation of vacuum, and the first stage of sulphonation is carried out in a standard sulphurator apparatus in a temperature interval of 140-168°C and pressure in the apparatus of 0-20 kPa, and at the second stage in the same apparatus without interruption of the technological process, vacuum -15÷-90 kPa is created with an exposure at a temperature of 150-155°C, with further increase of temperature at the end of the process to 160-165°C and obtaining a sulphomass with the total titratable acidity of 22.5-26%.

EFFECT: elaborated is the method of obtaining PNS with the regulated low content of sodium sulphate, which can be applied as dispersants of powder-like materials of different nature, in particular as superplasticisers of concrete mixtures and mortars.

5 cl, 4 tbl