Acrylic polymer composition

#1. Field of the Invention

#The present invention relates to an acrylic polymer composition having good flexibility, a molded or formed product containing the composition and having a desired balance between its flexibility and its mechanical properties, and methods of making and using the composition and the molded or formed product.

#2. Discussion of the Background

#Synthesis of a Block Copolymer (b) (see Table 1)

#A 1-liter three-necked flask was equipped with a three-way stopcock, followed by deaeration inside. After purging with nitrogen, 291 g of toluene, 29 g of 1,2-dimethoxyethane, and 15.2 g of a toluene solution containing 10 mmol of isobutylbis(2,6-di-t-butyl-4- methylphenoxy)aluminum was added at room temperature, followed by further addition of 1.0 mmol of sec-butyl lithium. After 12.0 g of methyl methacrylate was added to the resulting mixture and they were reacted at room temperature for 3 hours, 1 g of the reaction mixture was collected as a sampling material 1. Then, the inside temperature of the polymer solution was cooled to −25° C., to which 72 g of n-butyl acrylate was added dropwise over 8.5 hours. After completion of the dropwise addition, 1 g of the reaction mixture was collected as a sampling material 2. 12.0 g of methyl methacrylate was added to the reaction mixture. The resulting mixture was heated to 3° C. and stirring was conducted for 8 hours. Polymerization was terminated by the addition of 1 g of methanol to the reaction mixture. The reaction mixture after termination of polymerization was poured into a large amount of methanol to cause precipitation and the precipitate thus obtained was used as a sampling material 3.

#After the 1H-NMR and GPC measurements of the sampling materials 1 to 3, Mn (number average molecular weight), Mw/Mn (molecular weight distribution), and the weight ratio of methyl methacrylate polymer (PMMA)block /n-butyl acrylate polymer (PnBA)block were determined. As a result, it has been revealed that the precipitate obtained in the end was a triblock copolymer (PMMA-b-PnBA-b-PMMA) of PMMA block-PnBA block-PMMA block; the PMMA block portion had Mn of 13,200, and Mw/Mn of 1.06; the entire triblock copolymer had Mn of 130,000 and Mw/Mn of 1.15; and a ratio of the polymer blocks was PMMA (12 wt %)—PnBA (76 wt %)—PMMA (12 wt %).