| abstract |
The present invention provides an ultraviolet curable organosilicon composition with excellent curability by ultraviolet irradiation. The above-mentioned problem is solved by the following ultraviolet curable organosilicon composition, which includes: (A) an organopolysiloxane composition and (B) a photoinitiator that is miscible in organosilicon, of which (A) organic polysiloxane The silicone composition is selected from: (A-1) an organopolysiloxane composition, which comprises: a linear organopolysiloxane whose molecular chain ends are capped by alkenyl groups and/or molecular chain ends contain at least two An alkenyl branched organopolysiloxane, and an organopolysiloxane containing at least two mercapto groups on the side chain of the molecular chain and the mercapto group content is more than 1% by mass per molecule; (A-2) Organopolysiloxane An oxane composition comprising: a linear organopolysiloxane having both ends of the molecular chain terminated by mercapto groups and having a mercapto group content of 1% by mass or more per molecule, and a molecular chain side chain containing at least two alkenyl groups Organopolysiloxane and/or resinous organopolysiloxane containing at least two alkenyl groups at the end of the molecular chain; or (A-3) an organopolysiloxane composition comprising: alkenyl and aryl containing Organopolysiloxane and a polyfunctional thiol compound, wherein, when the polyfunctional thiol compound contains only a bifunctional thiol compound, the organopolysiloxane composition further contains an alkenyl group-containing resin Organopolysiloxane, (B) a photoinitiator that is miscible in organosilicon contains a compound selected from the group consisting of: (B-1) α-hydroxyacetophenone; (B-2) α-hydroxyacetophenone and A combination of α-aminoalkyl phenone; or (B-3) a combination of α-hydroxyacetophenone and mono-phosphine oxide, wherein the mercapto group and the alkene contained in the organopolysiloxane composition The base ratio (SH/Vi ratio) is 0.6 or more. |