Silica-containing insulating composition

    公开(公告)号:US11961636B2

    公开(公告)日:2024-04-16

    申请号:US16645750

    申请日:2018-09-07

    摘要: An insulating composition containing silica particles, a resin, and a curing agent, wherein: when an aqueous solution of the silica particles having an SiO2 concentration of 3.8% by mass is heated at 121° C. for 20 hours, the amount of Na ions eluted from the silica particles is 40 ppm/SiO2 or less, especially, wherein the amount of Na ions eluted from the silica particles after the heating may be 5-38 ppm/SiO2, and, the silica particles may contain a polyvalent metal oxide so the ratio by mole of a polyvalent metal M to Si is 0.001-0.02; the mass ratio of Na2O/SiO2 in the silica particles may be 700-1,300 ppm; and the silica particles may have, on the surfaces thereof, a layer having a thickness of 0.1-1.5 nm and an Na2O/SiO2 mass ratio of 10-400 ppm, and may have an average particle diameter of 5-40 nm.

    Silica sol dispersed in ketone solvent and resin composition

    公开(公告)号:US11168201B2

    公开(公告)日:2021-11-09

    申请号:US17270926

    申请日:2020-05-13

    摘要: A silica-blended resin varnish contains a silica sol with a high dispersibility that is dispersed in a ketone organic solvent, in a nitrogen atom-containing polymer. The particles have an average size of 5 to 100 nm and have a carbon-carbon unsaturated bond-containing organic group and an alkoxy group bonded to surfaces thereof. The carbon-carbon unsaturated bond-containing organic group is bonded at 0.5 to 2.0 groups per unit area (nm2) of the particle surfaces. The alkoxy group is bonded at 0.1 to 2.0 groups per unit area (nm2) of the particle surfaces. The molar ratio of {(the carbon-carbon unsaturated bond-containing organic group)/(the alkoxy group)} is 0.5 to 5.0. The carbon-carbon unsaturated bond-containing organic group may be a phenyl group-containing organic group or a (meth)acryloyl group-containing organic group. An insulating resin composition contains the silica sol and a nitrogen-containing polymer, which may be polyimide, polyamide, polyamic acid, polyamide-imide, polyetherimide, or polyesterimide.