US Patent 7978409 Hard coat layer-forming composition and optical lens

The hard coat layer-forming composition of this invention includes (A) composite oxide fine particles with a mean particle diameter of 1 to 200 nm, containing titanium, tin and optionally silicon, and with a rutile-type crystal structure, (B) an organosilicon compound represented by the formula R1aR2bSi(OR3)4−(a+b) and/or a hydrolyzate thereof, and (C) a cyanamide derivative compound. A hard coat layer formed from the composition not only is excellent in transparency, scratch resistance, adhesion property, weathering resistance, impact resistance, etc. but also can enjoy no coloration or little coloration, particularly in bluing or yellowing, upon exposure to or irradiation with ultraviolet rays, even if an antireflection film is provided.