Modified natural resin - by reacting resin with unscarboxylated unsaturated monomer and phenol/formaldehyde resin

摘要

The pdt is at least partly esterified with a polyfunctional alcohol and/or a small amt of a carboxylic acid. The natural resin is rosin. The monomer is styrene opt. mixes with other monomers. A max of 1 mole monomer is reacted with 1 mole resin. The reaction is effected in the presence of peroxides and/or accelerating metal salts, such as cobalt carbonate. The reaction pdt or the esterified reaction pdt is converted into a metal salt, pref. a zinc, magnesium or calcium salt. The pdt may be modified with other synthetic resins. The resin has stable viscosity during storage, good solubility in org. solvents and bonds firmly to a wide range of substrates including polyolefin films.