Methacrylic resin composition and optical component

Abstract

Provided is a methacrylic resin composition having excellent surface processability and displaying excellent preservability of formed surface processing. The methacrylic resin composition and an optical component contain a methacrylic resin including a structural unit (X) having a cyclic structure-containing main chain that is at least one selected from the group consisting of an N-substituted maleimide monomer-derived structural unit, a glutarimide-based structural unit, and a lactone ring structural unit. The methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C. Among methacrylic acid ester monomer-derived structural units, a ratio (S/H) of the integrated intensity (S) of a syndiotactic fraction (rr) relative to the integrated intensity (H) of a heterotactic fraction (mr), as determined by 1 H-NMR measurement, is 1.20 to 1.50. The amount of methanol-soluble content is 5 mass % or less relative to 100 mass %, in total, of methanol-soluble content and methanol-insoluble content.

1 . A methacrylic resin composition comprising
 a methacrylic resin including a structural unit (X) having a cyclic structure-containing main chain, the structural unit (X) being at least one selected from the group consisting of an N-substituted maleimide monomer-derived structural unit, a glutarimide-based structural unit, and a lactone ring structural unit, wherein   the methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C.,   among methacrylic acid ester monomer-derived structural units, a ratio (S/H) of integrated intensity (S) of a syndiotactic fraction (rr) relative to integrated intensity (H) of a heterotactic fraction (mr), as determined by 1H-NMR measurement, is 1.20 to 1.50, and   methanol-soluble content is contained in an amount of 5 mass % or less relative to 100 mass %, in total, of the methanol-soluble content and methanol-insoluble content.   
     
     
         2 . The methacrylic resin composition according to  claim 1 , having a weight average molecular weight (Mw) of 120,000 to 200,000 as measured by gel permeation chromatography as a polymethyl methacrylate equivalent molecular weight. 
     
     
         3 . The methacrylic resin composition according to  claim 1 , wherein
 the structural unit (X) includes an N-substituted maleimide monomer-derived structural unit, and   the N-substituted maleimide monomer-derived structural unit has a content of 5 mass % to 40 mass % relative to 100 mass % of the methacrylic resin.   
     
     
         4 . The methacrylic resin composition according to  claim 1 , wherein
 the structural unit (X) includes a lactone ring structural unit, and   the lactone ring structural unit has a content of 5 mass % to 40 mass % relative to 100 mass % of the methacrylic resin.   
     
     
         5 . The methacrylic resin composition according to  claim 1 , having a photoelastic coefficient with an absolute value of 2.0×10 −12  Pa −1  or less. 
     
     
         6 . The methacrylic resin composition according to  claim 5 , having a photoelastic coefficient with an absolute value of 1.0×10 −12  Pa −1  or less. 
     
     
         7 . An optical component comprising the methacrylic resin composition according to  claim 1 , wherein
 the optical component has an embossed section on at least part of either or both of a front surface and a rear surface.   
     
     
         8 . An optical component according to  claim 7  that is an optical film. 
     
     
         9 . The methacrylic resin composition according to  claim 2 , wherein
 the structural unit (X) includes an N-substituted maleimide monomer-derived structural unit, and   the N-substituted maleimide monomer-derived structural unit has a content of 5 mass % to 40 mass % relative to 100 mass % of the methacrylic resin.   
     
     
         10 . The methacrylic resin composition according to  claim 2 , wherein
 the structural unit (X) includes a lactone ring structural unit, and   the lactone ring structural unit has a content of 5 mass % to 40 mass % relative to 100 mass % of the methacrylic resin.   
     
     
         11 . The methacrylic resin composition according to  claim 2 , having a photoelastic coefficient with an absolute value of 2.0×10 −12  Pa −1  or less. 
     
     
         12 . The methacrylic resin composition according to  claim 3 , having a photoelastic coefficient with an absolute value of 2.0×10 −12  Pa −1  or less. 
     
     
         13 . The methacrylic resin composition according to  claim 4 , having a photoelastic coefficient with an absolute value of 2.0×10 −12  Pa −1  or less. 
     
     
         14 . The methacrylic resin composition according to  claim 11 , having a photoelastic coefficient with an absolute value of 1.0×10 −12  Pa −1  or less. 
     
     
         15 . The methacrylic resin composition according to  claim 12 , having a photoelastic coefficient with an absolute value of 1.0×10 −12  Pa −1  or less. 
     
     
         16 . The methacrylic resin composition according to  claim 13 , having a photoelastic coefficient with an absolute value of 1.0×10 −12  Pa −1  or less. 
     
     
         17 . An optical component comprising the methacrylic resin composition according to  claim 2 , wherein
 the optical component has an embossed section on at least part of either or both of a front surface and a rear surface.   
     
     
         18 . An optical component comprising the methacrylic resin composition according to  claim 3 , wherein
 the optical component has an embossed section on at least part of either or both of a front surface and a rear surface.   
     
     
         19 . An optical component comprising the methacrylic resin composition according to  claim 4 , wherein
 the optical component has an embossed section on at least part of either or both of a front surface and a rear surface.   
     
     
         20 . An optical component comprising the methacrylic resin composition according to  claim 5 , wherein
 the optical component has an embossed section on at least part of either or both of a front surface and a rear surface.