Rokryl SW25M is a specialist additive for the tanning industry. It is an anionic, aqueous acrylic dispersion used as a binding agent for the finishing process of very soft leather. The product is an acrylic copolymer, obtained by emulsion polymerization with the use of an appropriate dispersion system. It has the form of a homogeneous, milky dispersion. It is soluble in water, acetic acid and ethyl acetate. It shows excellent resistance to electrolytes.
The product is miscible with all the auxiliaries used in the mating kits for the leather coating process, as well as with other anionic synthetic resins. Rokryl SW25M does not thicken under the influence of ammonia water and other alkali. Moreover, it does not show any tendency to delaminate and increase of viscosity during storage.
Rokryl SW25M is sensitive to low temperatures. It freezes below 0°C and after thawing it delaminates and loses its functional properties.
The product forms water-resistant films on leather surfaces. The use of Rokryl SW25M on its own provides soft coatings with good adhesion to leather surface. When used together with anionic dispersions of harder polymers, it increases the adhesion of the coatings to leather surfaces and its resistance to multiple bending. In addition, when used in combination with Rokryl SW115 it enables obtaining coatings with high water resistance and resistance to friction.