METHOD FOR CONTROL BY HIGH-FREQUENCY TITRATION OF THE POLYCONDENSATION STAGE IN THE PRODUCTION OF ALKYD LACQUERS Russian patent published in 2021 - IPC G01N27/06 

FIELD: analytical chemistry.

SUBSTANCE: invention relates to the field of studying the properties of organic and inorganic liquids by high-frequency titration methods, in particular to operational methods for controlling the polycondensation stage in the production of alkyd lacquers. The essence of the method lies in the fact that during the synthesis of alkyd resins in the production of alkyd lacquers, the Q-factor of a parallel oscillatory circuit is measured in time, in which the liquid under study (reaction mass) is used as a load. When the electrical conductivity of the reaction mass changes, the amount of power dissipated in the oscillating circuit changes, which leads to a change in the Q-factor of the oscillating circuit, which is defined as the ratio of the reactance of the oscillating circuit to the active resistance of the circuit. The change in Q-factor is determined by the change in the magnitude of the current flowing through the circuit. It is determined that the Q-factor value increases during synthesis, which is explained by the fact that at the beginning of synthesis the reaction mass is heterogeneous, is a mixture of liquids and solid components and is close to conductors in its properties, and then, during chemical reactions, the reaction mass becomes homogeneous, approaches dielectrics in structure, conductivity decreases, Q-factor increases. The Q-factor measurements of the parallel circuit were carried out, in which the reaction mass samples taken during the polycondensation process in the production of alkyd lacquers PF-060 and PF-053 were used as a load. It is determined that the Q-factor increases during the reaction. It is also determined that the Q-factor increases with the viscosity of the reaction mass and the dependence of the Q-factor on the viscosity is found. It is proposed to use the dependence of Q-factor on viscosity to control the polycondensation stage in the production of alkyd lacquers: when the Q-factor value corresponding to the viscosity value determined by the regulations is reached, stop the process. It is determined that the nature of the dependences of Q-factor on viscosity is identical for the processes of production of alkyd lacquers PF-060 and PF-053, which suggests that the proposed method for controlling the polycondensation stage can be used for a wide range of types of alkyd lacquers.

EFFECT: creation of a fast-acting, accurate method for controlling the technological process of polycondensation in the production of alkyd lacquers and resins, using the fact that the values of the electrophysical parameters of the reaction mass are directly dependent on the value of its viscosity.

1 cl, 6 dwg