Fluoropolymer modified acrylic capstock
View Patent ↗The invention relates to the use of an impact-modified acrylic blend with a low level of fluoropolymer to achieve impact resistance and solvent resistance in a capstock formulation. Preferably the acrylic blend contains a methyl methacrylate-based acrylic polymer and polyvinylidene fluoride.
1. An impact-modified acrylic composition consisting of a blend of:
a) 30 to 70 weight percent of one or more acrylic copolymer(s) consisting of methyl methacrylate units and 2-16 weight percent of one or more C 1-4 alkyl acrylate monomer units, the weight percent based on the total of all acrylic monomer units in the acrylic copolymer,
b) 16-25 weight percent of fluoropolymer;
c) 30 to 70 weight percent of one or more polymeric core-shell impact modifier(s)
wherein the weight percent of a), h), and c) is based on the weight of the impact-modified acrylic composition, and
d) 1.0 to 15 weight percent of one or more additive(s) selected from the group consisting of anti-oxidants, UV absorbers, lubricants, colorants and dyes, the weight percent based on the total weight of the impact-modified acrylic composition,
wherein said composition is a capstock,
the total acrylic composition adding to 100 weight %.
2. The impact-modified acrylic composition of claim 1 , wherein said fluoropolymer is polyvinylidene fluoride.
3. A polymer composite comprising a structural polymer having directly adhered thereto an impact-modified acrylic composition capstock layer, consisting of a blend of:
a) 30 to 70 weight percent of one or more acrylic copolymer(s) consisting of methyl methacrylate units and 2-16 weight percent of one or more C 1-4 acrylate monomer units, the weight percent based on the total of all acrylic monomer units in the acrylic copolymer, and
b) 16-25 weight percent of fluoropolymer; and
c) 30 to 70 weight percent of one or more polymeric core-shell impact modifiers,
wherein the weight percent of a), b), and c) is based on the total weight of the impact-modified acrylic composition, and
d) 1.0 to 15 weight percent of one or more additives selected from the group consisting of anti-oxidants, UV absorbers, lubricants, colorants and dyes, the weight percent based on the total weight of the impact-modified acrylic composition,
wherein the impact-modified acrylic composition capstock layer has a thickness of from 0.1 to 2.5 mm,
the total composition adding to 100 weight percent.
4. The polymer composite of claim 3 , wherein said structural polymer comprises acrylonitrile/butadiene/styrene (ABS) copolymer, polyvinyl chloride, polycarbonate, polycarbonate/ABS blend, ABS/nylon blend, glass reinforced polyester thermosets, or a polycarbonate/nylon blend.
5. The polymer composite of claim 4 wherein said polyvinyl chloride structural polymer is selected from the group consisting of a non-foamed polyvinyl chloride, a chlorinated polyvinyl chloride, a foamed polyvinyl chloride, an impact modified polyvinyl chloride, and a wood-polyvinyl chloride composite.
6. A method of retaining and controlling gloss and improving solvent resistance in an impact-modified acrylic composition comprising adding from 16-25 weight percent, based on the weight of the acrylic composition, of one or more fluoropolymers to the acrylic composition; wherein said acrylic composition consists of 30 to 70 weight percent of one or more acrylic copolymer(s), 30 to 70 weight percent of one or more polymeric core-shell impact modifier(s), and 1.0 to 15 weight percent of one or more additives selected from the group consisting of anti-oxidants, UV absorbers, lubricants, colorants and dyes, the weight percent based on total weight of the impact-modified acrylic composition, the total of said acrylic composition adding to 100 weight percent; wherein said acrylic copolymer consists of methyl methacrylate monomer units and 2-16 weight percent of one or more C 1-4 acrylate monomer units, the weight percent based on the total of all acrylic monomer units in the acrylic copolymer.