Abstract: A process of forming a seed polymer for use in an emulsion polymerization reaction. The process includes the steps of providing an aqueous mixture of styrene, emulsifying agent, initiator and at least one polymerizable di- or tri-carboxylic acid and then polymerizing the aqueous mixture in the presence of a nonpolymerizable di- or tri-carboxylic acid to form the seed polymer.

Abstract: An emulsion acrylate copolymer is provided which unexpectedly is an effective magnetic binder inasmuch as it can be loaded with high amounts of one or more magnetic particles such as ferrite or ferrite containing materials to provide a flexible permanent type magnetic composition of high magnetic energy. The copolymer is made from an alkyl acrylate and a salt of 2-acrylamido-2-methylpropane sulfonic acid (AMPS). A carboxylated ethoxy alkyl phenol surfactant is utilized which provides good processability and permits a blend of the magnetic particles with the emulsion acrylate copolymer to be precipitated from a latex solution by high shear mixing. Flexible high magnetic energy magnets can thus be made and utilized in various applications such as refrigerator doors, electrical motors, and the like.

Abstract: An emulsion acrylate copolymer is provided which unexpectedly is an effective magnetic binder inasmuch as it can be loaded with high amounts of one or more magnetic particles such as ferrite or ferrite containing materials to provide a flexible permanent type magnetic composition of high magnetic energy. The copolymer is made from an alkyl acrylate and a salt of 2-acrylamido-2-methylpropane sulfonic acid (AMPS). A carboxylated ethoxy alkyl phenol surfactant is utilized which provides good processability and permits a blend of the magnetic particles with the emulsion acrylate copolymer to be precipitated from a latex solution by high shear mixing. Flexible high magnetic energy magnets can thus be made and utilized in various applications such as refrigerator doors, electrical motors, and the like.