Patent ID: 11958970
Assignee: TOKUYAMA DENTAL CORPORATION
Field: Pharmaceuticals (Chemistry)
Classification: CPC A  C  Y | IPC A  C

Claim 5:
6. A method for producing a resin block for dental cutting work that contains a resin matrix (A) and a spherical filler (B) whose average particle size falls within a range of 230 nm to 1000 nm, wherein the resin block for dental cutting work further comprises inorganic particles (C) having an average particle size of less than 100 nm, and wherein an amount of the inorganic particles (C) is 0.1 to 30 parts by mass, relative to 100 parts by mass of the resin matrix (A); the method comprising polymerizing a curable composition, which contains a polymerizing monomer, a spherical filler (B) whose average particle size falls within a range of 230 nm to 1000 nm, inorganic particles (C) having an average primary particle size of less than 100 nm, and a polymerization initiator, and in which 90% or more of the individual particles constituting the spherical filler (B) are present within a range of the average particle size ±5%, and the polymerizing monomer and the spherical filler (B) each are selected so as to satisfy a requirement (X2) represented by the following expression (2):

nPm<nF  (2)

where nPm represents a refractive index at 25° C. of a polymer obtained through polymerization of the polymerizing monomer, and nF represents a refractive index of the spherical filler (B) at 25° C.; and wherein the resin block for dental cutting work is such that, when having a thickness of 10 mm and as measured with a colorimeter, the lightness (V) is less than 5.0 and the saturation (C) is less than 2.0 as measured values in a Munsell color system of the colored light on a black background and a white background, and is such that, when having a thickness of 1 mm and as measured with a colorimeter, the lightness (V) is less than 5.0 and the saturation (C) is 0.05 or more as measured values in a Munsell color system of the colored light on a black background, but on a white background, the lightness (V) is 6.0 or more and the saturation (C) is less than 2.0 as measured values in a Munsell color system of the colored light.