Copolymer, process for producing copolymer, resin composition, shaped article and vehicle
The present invention provides a copolymer containing 80 mol % or more of a methyl (metl)acrylate unit (A), wherein the Vicat softening temperature thereof is 115° C. or higher, the saturated water absorption rate thereof at 60° C. is 4 % by weight or less, and the yellow index thereof is 1 or less. The process for producing the copolymer includes suspension polymerizing a monomer mixture containing 80 mol % or more of methyl (meth)acrylate (a) and 0.7 mol % to 7 mol % of (meth)acrylic acid (b), followed by melting and kneading the resulting precursor with an extruder to obtain a copolymer containing 80 mol % or more of a methyl (meth)acrylate unit (A), 0.45 mol % to 7 mol % of a (meth)acrylic acid unit (B), and 0.001 mol % to 0.25 mol % of a glutaric anhydride unit (C) wherein a conversion rate to the glutaric anhydride unit (C) is 0.1 % to 5 %.
1. A copolymer comprising:
80 mol % or more of a methyl (meth)acrylate unit (A),
0.45 mol % to 7 mol % of a (meth)acrylic acid unit (B), and
0.001 mol % to 0.15 mol % of a glutaric anhydride unit (C),
wherein a conversion rate to the glutaric anhydride unit (C) as represented by equation (1) is 0.1% to 5%:
Conversion rate to glutaric anhydride unit (C) (%)={[ratio of glutaric anhydride unit (C) in copolymer (mol %)]/([ratio of (meth)acrylic acid unit (B) in copolymer (mol %)]+[ratio of glutaric anhydride unit (C) in copolymer (mol %) ])}×100 (1).
2. The copolymer according to claim 1 , comprising 90 mol % or more of the methyl (meth)acrylate unit (A), 0.5 mol % to 6 mol % of the (meth) acrylic acid unit (B), and 0.001 mol % to 0.15 mol % of the glutaric anhydride unit (C).
3. The copolymer according to claim 1 , wherein the conversion rate to the glutaric anhydride unit (C) as represented by the equation (1) is 0.1% to 3%.
4. The copolymer according to claim 1 , wherein a saturated water absorption rate at 60° C. is 4% by weight or less.
5. The copolymer according to claim 1 , wherein a melt flow rate at a load of 13.65 kgf and temperature of 230° C. is 10 g/10 minutes or more.
6. The copolymer according to claim 1 , wherein a yellow index is 1 or less.
7. A resin composition comprising the copolymer according to claim 1 .
8. A shaped article obtained by shaping the resin composition according to claim 7 .
9. A vehicle comprising the shaped article according to claim 8 .