gummirester

Gummirester is a term used in polymer science to describe a class of resinous esters derived from natural gum rosin and related gum resins. The most common members are glycerol esters of rosin (GER), often marketed as rosin esters. The terminology varies by supplier and region; gummirester may refer broadly to rosins ester derivatives.

Production and structure: Gummiresters are prepared by esterifying rosin acids with polyols such as glycerol, pentaerythritol, or trimethylolpropane in the presence of an acid catalyst, followed by purification. The polyol choice and degree of esterification control properties such as softening point, acid value, and solubility. Gummiresters are more resistant to heat and oxidation than raw rosin and generally exhibit improved compatibility with hydrocarbon and other synthetic resins.

Applications: They are used as tackifiers and plasticizers in hot-melt adhesives, pressure-sensitive adhesives, rubber compounds, vinyl resins, printing inks, and coatings. Gummiresters help improve tack, adhesion, and aging resistance and are often formulated with EVA, hydrocarbon resins, or terpene resins to tailor performance for specific systems.

Commercial and regulatory notes: Gummirester products are supplied by chemical and adhesive manufacturers under various trade names. They are selected based on compatibility with the resin system and the required temperature performance. Handling follows standard chemical safety guidelines; some rosin derivatives can be skin sensitizers and require appropriate ventilation and protective equipment.