[Study on visible-light curing soft resins consisting of fluoropolymers. 2. Effect of fluoroalkyl alpha-fluoroacrylate monomers].

New experimental visible-light cured soft resins were prepared by combining a vinylidene fluoride/hexafluoropropylene copolymer (2-6 F), or a vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene copolymer (2-4-6 F) with 2,2,3,3-tetrafluoropropyl alpha-fluoroacrylate (4 FFA), 2,2,3,3,3-pentafluoropropyl alpha-fluoroacrylate (5 FFA), 2,2,3,3,4,4,5,5-octafluoropentyl alpha-fluoroacrylate (8 FFA), or 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl alpha-fluoracrylate (12 FFA). Some properties of the resins prepared were measured to determine whether they would be candidate materials for the soft denture liner. Water contact angles increased with the increase in the number of fluorine atoms contained in the monomers: 85-90 degrees in 4 FFA, 90-93 degrees in 8 FFA, and 92-93 degrees in 12 FFA. Softer resins were obtained with 2-4-6 F, especially by the combination with 8 FFA giving the softest resin with a hardness of 43-46 (JIS A). Water sorption after 10 weeks was considerably low: 0.4-2%: 0.4-0.9% in 4 FFA/2-6 F and about 2% in 8 FFA/2-4-6 F. Solubility was 0.2-0.4% in the resins with 4 FFA and 1.0-1.4% with 8 FFA or 12 FFA. Amount of residual monomer was low, and the maximum was 0.4% in the resin with 12 FFA. Thus hardness and water sorption of the resins prepared were superior to those of the commercial soft materials.