| abstract |
The invention relates to composite polymer modifiers for thermoplastic resins, and especially for polyvinyl chloride (PVC). The composite modifier is an intimate blend of mineral filler and polymeric process aid, which is formed by the co-powderization of aqueous emulsions, suspensions or slurries of one or more mineral filler(s) and process aid(s). The resulting composite modifier provides more effective modification of the thermoplastic resin than by the use of the dried components formed separately. The composite modifier may also contain other co-powderized components such as impact modifiers, for additional benefits. |