Introduction of Cu(II) complex into transparent synthetic resin and optical function of the resin as a near‐infrared ray cutoff filter

A mole ratio method was conducted to determine a necessary condition to solubilize Cu(II) ion into an organic solvent. Copper benzoate anhydrous (CB) and acetone was used as a Cu(II) ion supplier and a solvent, respectively. Methacryloyloxy-ethyl phosphate (PMOE) and di(2-ethylhexyl) phosphate (DIEHP) were used asligands for solubilization. Cu(II) ion was solubilized with only two PMOE molecules, although six molecules were needed for DIEHP. PMOE formed an intermediate layer which surrounded the Cu(II) ion with two molecules between the ion and solvent and made it possible to solubilize Cu(II) ion into the organic solvent. In the case of DIEHP, however, six molecules were needed to form such a layer for solubilization. Furthermore, Cu(II) ion was introduced homogeneously into poly(methyl methacrylate) (PMMA) by copolymerization of PMOE with MMA, although the polymer was opaque in the case of DIEHP. The ligand having a methacryloyl group was considered to participate in the polymerization process, which avoided exclusion of the Cu(II) complex from polymer phase. The intermediate zone formed by PMOE was considered to keep compatibility of Cu(II) ion with the polymer matrix even after polymerization. The near-infrared ray cutting-off filter made of resin was realized by introducing Cu(II) ion at higher concentration through complexation with the proper ligand. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:903–912, 1998