# US 8,785,522 B2 · Low-permittivity resin composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,522 B2 - Document ID: US8785522B2 - Status: Granted - Kind: B2 - Application number: 13/383,698 - Filed: 2010-07-06 - Published: 2012-05-17 - Granted: 2014-07-22 - Earliest claimed: 2009-07-14 - Assignees: Kao Corporation - Applicants: Toshihiro Yano; Masaki Komatsu - Inventors: Toshihiro Yano; Masaki Komatsu - Web page: https://patentgrep.com/patent/US8785522B2 ## CPC - C09D 5/024: {characterised by the additives} - C09D 7/61: inorganic - C09D 7/67: {Particle size smaller than 100 nm} - C09D 7/68: {Particle size between 100-1000 nm} - C09D 7/69: {Particle size larger than 1000 nm} - C09D 7/70: {characterised by shape, e.g. fibres, flakes or microspheres} - C08K 7/26: Silicon- containing compounds - H01B 3/40: epoxy resins - H01B 3/447: {from acrylic compounds} - H01B 3/46: silicones - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) ## Abstract The present invention relates to a low-dielectric resin composition having sufficiently low dielectric constant and dissipation factor, a low-dielectric film formed of the low-dielectric resin composition, processes for producing the low-dielectric resin composition and the low-dielectric film, and a coating agent for low-dielectric films. According to the present invention, there are provided (1) a low-dielectric resin composition including hollow silica particles having an average particle size of from 0.05 to 3 μm and a BET specific surface area of less than 30 m2/g, and a matrix resin in which the hollow silica particles are dispersed; (2) a low-dielectric film including the low-dielectric resin composition; (3) a process for producing the low-dielectric resin composition which includes the steps of preparing hollow silica particles (A) containing air inside thereof or core/shell type silica particles (B) in which a material capable of being dissipated by calcination to form hollow portions therein is encapsulated; calcination the hollow silica particles (A) or the core/shell type silica particles (B) at a temperature higher than 950° C. to prepare hollow silica particles (C); and dispersing the hollow silica particles (C) in a matrix resin-forming material to prepare a dispersion of the particles; and (4) a coating agent for low-dielectric films including the hollow silica particles, and a matrix resin-forming material in which the hollow silica particles are dispersed. ## Claims ### Claim 1 A low-dielectric resin composition, comprising hollow silica particles having an average particle size of from 0.05 to 2.2 μm and a BET specific surface area of less than 30 m2/g, and a matrix resin in which the hollow silica particles are dispersed. ### Claim 2 A low-dielectric resin composition comprising hollow silica particles having an average particle size of from 0.05 to 1 μm with the proviso that 80% by mass or more of the whole particles have a particle size falling within the range of the average particle size ±30%, and a BET specific surface area of less than 30 m2/g, and a matrix resin in which the hollow silica particles are dispersed. ### Claim 3 A low-dielectric resin composition, comprising hollow silica particles having an average particle size of from 0.05 to 2.2 μm, a porosity of from 30 to 90% and a BET specific surface area of less than 30 m2/g, and a matrix resin in which the hollow silica particles are dispersed. ### Claim 4 (depends on 1) The low-dielectric resin composition according to claim 1, wherein when subjected to powder X-ray diffraction measurement, the hollow silica particles exhibit a diffraction pattern in which no peaks are observed at a diffraction angle (2θ) corresponding to a crystal lattice spacing (d) of less than 1 nm. ### Claim 5 The low-dielectric resin composition according to 1, wherein a content of the hollow silica particles in the composition is from 10 to 60% by mass. ### Claim 6 (depends on 3) The low-dielectric resin composition according to claim 3, wherein a volume ratio of air in the resin composition is from 3 to 60%. ### Claim 7 (depends on 1) A low-dielectric film comprising a low-dielectric resin composition as defined in claim 1. ### Claim 8 (depends on 1) A process for producing a low-dielectric resin composition as defined in claim 1, comprising: preparing hollow silica particles (A) comprising air inside thereof or core/shell silica particles (B) in which a material capable of being dissipated by calcination to form hollow portions therein is encapsulated; calcining the hollow silica particles (A) or the core/shell type silica particles (B) obtained in said preparing at a temperature higher than 950° C. to prepare hollow silica particles (C); and dispersing the hollow silica particles (C) obtained in said calcining in a matrix resin-forming material to prepare a dispersion of the particles. ### Claim 9 (depends on 8) The process for producing a low-dielectric film according to claim 8, further comprising applying the dispersion obtained in said dispersing onto a substrate and then solidifying the applied dispersion. ### Claim 10 (depends on 8) The process for producing a low-dielectric film according to claim 8, wherein the matrix resin-forming material has a viscosity of from 0.1 to 20 Pa's. ### Claim 11 A coating agent for low-dielectric films, comprising hollow silica particles having an average particle size of from 0.05 to 2.2 μm and a BET specific surface area of less than 30 m2/g, and a matrix resin-forming material in which the hollow silica particles are dispersed. ### Claim 12 A coating agent for low-dielectric films comprising hollow silica particles having an average particle size of from 0.05 to 1 μm with the proviso that 80% by mass or more of the whole particles have a particle size falling within the range of the average particle size ±30%, and a BET specific surface area of less than 30 m2/g, and a matrix resin-forming material in which the hollow silica particles are dispersed. ### Claim 13 A coating agent for low-dielectric films, comprising hollow silica particles having an average particle size of from 0.05 to 2.2 μm, a porosity of from 30 to 90% and a BET specific surface area of less than 30 m2/g, and a matrix resin-forming material in which the hollow silica particles are dispersed. ### Claim 14 (depends on 2) The low-dielectric resin composition according to claim 2, wherein when subjected to powder X-ray diffraction measurement, the hollow silica particles exhibit a diffraction pattern in which no peaks are observed at a diffraction angle (2θ) corresponding to a crystal lattice spacing (d) of less than 1 nm. ### Claim 15 (depends on 3) The low-dielectric resin composition according to claim 3, wherein when subjected to powder X-ray diffraction measurement, the hollow silica particles exhibit a diffraction pattern in which no peaks are observed at a diffraction angle (2θ) corresponding to a crystal lattice spacing (d) of less than 1 nm. ### Claim 16 (depends on 2) The low-dielectric resin composition according to claim 2, wherein a content of the hollow silica particles in the composition is from 10 to 60% by mass. ### Claim 17 (depends on 3) The low-dielectric resin composition according to claim 3, wherein a content of the hollow silica particles in the composition is from 10 to 60% by mass. ### Claim 18 (depends on 2) A process for producing the low-dielectric resin composition as defined in claim 2, comprising: preparing hollow silica particles (A) comprising air inside thereof or core/shell silica particles (B) in which a material capable of being dissipated by calcination to form hollow portions therein is encapsulated; calcining the hollow silica particles (A) or the core/shell type silica particles (B) obtained in said preparing at a temperature higher than 950° C. to prepare hollow silica particles (C); and dispersing the hollow silica particles (C) obtained in said calcining in a matrix resin-forming material to prepare a dispersion of the particles. ### Claim 19 (depends on 18) The process for producing a low-dielectric film according to claim 18, further comprising: applying the dispersion obtained in said dispersing onto a substrate and then solidifying the applied dispersion. ### Claim 20 (depends on 3) A process for producing the low-dielectric resin composition as defined in claim 3, comprising: preparing hollow silica particles (A) comprising air inside thereof or core/shell silica particles (B) in which a material capable of being dissipated by calcination to form hollow portions therein is encapsulated; calcining the hollow silica particles (A) or the core/shell type silica particles (B) obtained in said preparing at a temperature higher than 950° C. to prepare hollow silica particles (C); and dispersing the hollow silica particles (C) obtained in said calcining in a matrix resin-forming material to prepare a dispersion of the particles. ### Claim 21 (depends on 20) The process for producing a low-dielectric film according to claim 20, further comprising: applying the dispersion obtained in said dispersing onto a substrate and then solidifying the applied dispersion. ### Claim 22 (depends on 1) The low-dielectric resin composition according to claim 1, wherein 80% by mass or more of all of said particles have a particle size falling within the range of the average particle size ±30%.