Tokuyama Corporation

Ikumi Kawaguchi

Katsuhiro Mori

Hironobu Nagoh

Yuichiro Kawabata

[Problem] To provide a coating composition capable of forming a hard coating on the surfaces of an optical base member such as a plastic lens featuring highly closely adhering property, excellent transparency and excellent scratch resistance. [Means for Solution] The coating composition comprise (a) a fine granular silica having a grain size of not larger than 30 nm; (b) organosilicon compound components containing an epoxy group-containing organosilicon compound (b1) and tetraalkoxysilane (b2) at a mass ratio (b1/b2) of 0.25 to 4.0; (c) water; and (d) a curing catalyst comprising a complex containing aluminum as a core metal, wherein the fine granular silica (a) is contained in an amount of 15 to 55 parts by mass, the water (c) is contained in an amount of 30 to 200 parts by mass and the curing catalyst (d) is contained in an amount of 0.1 to 5.0 parts by mass per the total amount of the fine granular silica (a) and the organosilicon compound components (b) of 100 parts by mass.

Coating composition and photochromic optical article

A photochromic optical element comprising an optical substrate, a photochromic coat layer, and a hard coat layer that are laminated in this order, wherein (I) the photochromic coat layer comprising an alkylamino group-containing photochromic compound and/or a dialkylamino group-containing photochromic compound in a total amount of 0.1 to 10.0% by mass, and (II) the hard coat layer is obtained by curing a hard coat agent comprising metal oxide fine particles and an organosilicon compound, the hard coat agent containing as the organosilicon compound at least one selected from the group consisting of a tetraalkoxy silane, a methyl trialkoxy silane, and partial hydrolysates thereof in an amount of 10 to 60% by mass based on the total mass of the metal oxide fine particles and the organosilicon compound.

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Shunan, Japan

Ikumi Kawaguchi