Modification of rosin resin acids to improve their hydrophobizing action on paper and cardboard

The modification of rosin resin acids, which improves their hydrophobic effect on paper and cardboard, is based on the implementation of 6 stages. Control of chemical processes at each stage is carried out by monitoring and regulating temperature and flow parameters, which determine the achievement of the required physical and chemical properties and composition of intermediates and final substance. One of the main indicators is the acid number, which for the final substance should be 60–70 mg KOH/g, which corresponds to the content of free resin acids in the functional substance of 40–45 %. The fulfillment of the specified temperature and consumption parameters for the modification of resin acids of rosin and the achievement of the necessary physicochemical properties of intermediates at each stage ensures the production of a functional substance with an improved hydrophobic effect on paper and cardboard. Compared to the traditionally used TM adhesive-paste, the developed functional substance in the production of paper with absorbency at one-sided wetting of not more than 21 g/m2 provides a reduction in the content of particles of the dispersed phase of the rosin emulsion by 1.4–2.0 times, which indicates its improved properties, and maximum preservation of the original strength of the paper by reducing the distance between the fibers due to a 3.3–3.8 times reduction (from 4200–5000 to 1100–1480 nm) in the size of sizing complexes.