Composition comprising a copolymer comprising methyl methacrylate, (meth)acrylic acid and styrene monomers
The present invention relates to a polymer composition comprising a polymer comprising methyl methacrylate, (meth)acrylic acid and styrene monomers. In particular, the present invention relates to a polymer composition comprising a polymer comprising methyl methacrylate, (meth)acrylic acid and styrene monomers, said composition having particularly advantageous compromises of heat-resistant, fluidity, scratch-resistant and chemical-resistant properties. The present invention also relates to a molded or extruded object comprising a polymer comprising methyl methacrylate, (meth)acrylic acid and of styrene monomers, and the use of these objects.
1. A polymer composition suitable for the manufacture of molded or injection-molded, or extruded objects, said polymer comprising methyl methacrylate monomer units in weight proportions of between 88% and 90%, styrene monomer units in weight proportions of between 5.5% and 8%, acrylic and/or methacrylic acid monomer units in proportions of between 3.5% and 5%, wherein the composition has the properties:
a melt flow index of between 4 and 7 g/10 minutes, measured according to the standard ISO 1133-2:2011 at 230° C. and 3.8 kg load;
a Vicat softening temperature of between 110° C. and 120° C., measured at a load of 50 N according to the standard ISO 306:2013 method B50.
2. The composition as claimed in claim 1 , prepared by radical polymerization.
3. The composition as claimed in claim 1 , prepared by controlled radical polymerization.
4. The composition as claimed in claim 1 , having a melt flow index of between 4 and 6.5 g/10 minutes.
5. A process for preparing a polymer composition as claimed in claim 1 , comprising the steps of:
a) preparing a mixture comprising three monomers
a1) of methyl methacrylate in weight proportions varying from 8% to 90%,
a2) of styrene in weight proportions varying from 3.5% to 8%, a3) of methacrylic acid and/or of acrylic acid in weight proportions varying from 3.5% to 5% all the proportions being relative to the sum of the three monomers a1), a2) and a3),
b) polymerizing the mixture obtained in step a).
6. The process as claimed in claim 5 , wherein the polymerization is carried out by radical polymerization.
7. The process as claimed in claim 5 , wherein the polymerization is carried out by controlled radical polymerization.
8. A molded or extruded object manufactured from a composition as claimed in claim 1 .
9. The object as claimed in claim 8 , in the form of a sheet, a block, a film, a tube or a profiled element.
10. The object as claimed in claim 8 , selected from the group consisting of light guides, lenses, decorative motor vehicle parts, front and rear motor vehicle headlamp parts, tail light, lamp covers, dashboard windows, aggregates, oven facades, parts of household appliances, optical films, decorative films, upper protective layers of coextruded multilayer structures.