Composite functionalized acrylic process aids for gloss and surface modification

A composite polymer process aid comprising:

• a) from 99 to 1 weight %, based on the total weight of the composite polymer process aid, of one or more inorganic mineral fillers, and
• b) from 1 to 99 weight %, based on the total weight of the composite polymer process aid of one or more functionalized polymers, wherein the functionalized polymers comprise at least one base polymer functionalized with about 0.5 weight % to about 35 weight %, based on the total weight of the functionalized polymer, of at least one of an epoxy, hydroxyl, β-keto ester, β keto amide, or carboxylic acid reactive functional group;
• wherein the composite polymer process aid is in a form of a plurality of individual particles and at least a portion of the individual particles comprise both the a) one or more inorganic mineral fillers and the b) one or more functionalized polymers,
• wherein the b) one or more functionalized polymers include a soluble fraction and an insoluble fraction, wherein the insoluble fraction ranges from 1% to 90% of the total weight of the one or more functionalized polymers using extraction with acetone as a solvent, and a weight average molecular weight of the functionalized polymers, as measured on the soluble fraction, is greater than 100,000 g/mol, and
• wherein the composite polymer modifier is formed by a process comprising the steps of:
• i) blending the a) one or more inorganic mineral fillers with the b) one or more functionalized polymers to form an aqueous blend, and optionally with c) at least one impact modifier, and
• ii) powderizing the aqueous blend to form the composite polymer process aid.