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US5376347A Expired / Lapsed US ⏱️ 0.0 years remaining

Uniform inorganic micropheres and production thereof

Assignee: SUZUKI YUSHI INDUSTRIAL Co Ltd
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Filing: 1992-07-15
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Granted: 1994-12-27
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Expires: 2012-07-15
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Abstract

Abstract A method of producing uniform inorganic microspheres with a particle size of 0.01 to 500 μm by injecting an aqueous solution containing a particle-forming material into an organic solvent. The method includes injecting the aqueous solution into the organic solvent through a macromolecular membrane having a hydrophobic surface and having pores substantially uniform in pore size and extending in the direction of thickness of the membrane, substantially straight through the membrane, so that a path length of each of the pores corresponds substantially to a thickness of the membrane, to form, in said organic solvent, a large number of emulsion particles substantially uniform in size and then producing uniform inorganic microspheres from said emulsion particles on a one emulsion particle-to-one microsphere basis. The pores in the membrane are formed by either a corpuscular or laser beam.

Inventors

  • 👤 Masamichi Ipponmatsu
  • 👤 Masashi Nishigaki
  • 👤 Akira Hirano
  • 👤 Tsuyoshi Tsurutani

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 15:48
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/0007; B; B01; B01F; B01F23/00; B01F23/40; B01F23/41; B01F23/4105; B01F25/00; B01F25/30; B01F25/31; B01F25/313; B01F25/314; B01F25/3142; B01F25/31421; B01F25/50; B01F25/51; B01J; B01J2/00; B01J2/02; B01J2/06; B01J2/08; B01J4/00; B01J4/04; B01F2025/91; B01F2025/918

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 121 words
A method of producing uniform inorganic microspheres with a particle size of 0.01 to 500 μm by injecting an aqueous solution containing a particle-forming material into an organic solvent, said method comprising injecting said aqueous solution into said organic solvent through a macromolecular membrane having a hydrophobic surface and having pores substantially uniform in pore size and extending in the direction of thickness of the membrane, substantially straight through the membrane, so that a path length of each of the pores corresponds substantially to a thickness of the membrane, to form, in said organtic solvent, a large number of emulsion particles substantially uniform in size; and producing uniform inorganic microspheres from said emulsion particles on a one emulsion particle-to-one microsphere basis.
Claim 2
Independent Claim 121 words
A method of producing uniform inorganic microspheres with a particle size of 0.01 to 500 μm by injecting an aqueous solution containing a particle-forming material into an organic solvent, said method comprising injecting said aqueous solution into said organic solvent through a macromolecular membrane having a hydrophobic surface and having pores substantially uniform in pore size and extending in the direction of thickness of the membrane, substantially straight through the membrane, so that a path length of each of the pores corresponds substantially to a thickness of the membrane, to form, in said organtic solvent, a large number of emulsion particles substantially uniform in size; and producing uniform inorganic microspheres from said emulsion particles on a one emulsion particle-to-one microsphere basis.
Claim 3
Dependent Claim 26 words
A method of producing uniform inorganic microspheres as claimed in claim 1, wherein said macromolecular membrane has a thickness 5 to 2,000 times the pore size.
Claim 4
Dependent Claim 44 words
A method of producing uniform inorganic microspheres as claimed in claim 1, wherein the emulsion particle-containing organic solvent is mixed with an aqueous solution containing a precipitant capable of causing precipitation of the emulsion particles and the resulting water-insoluble precipitate is dried and calcined.
Claim 5
Dependent Claim 28 words
A method of producing uniform inorganic microspheres as claimed in claim 1, wherein the aqueous solution to give emulsion particles is an aqueous solution of a basic salt.
Claim 6
Dependent Claim 21 words
A method of producing uniform inorganic microspheres as claimed in claim 4, wherein said basic salt is an alkali metal silicate.
Claim 7
Dependent Claim 63 words
A method of producing uniform inorganic microspheres as claimed in claim 1, wherein the aqueous solution to give emulsion particles is a sol of the particle-forming material and wherein said sol is injected into the organic solvent and the resulting sol emulsion particles are caused to gelate by promoting the polymerization reaction and the thereby formed particle precursor precipitate is dried and calcined.
Claim 8
Dependent Claim 29 words
A method of producing uniform inorganic microspheres as claimed in claim 6, wherein the particle-forming material sol is a silica sol prepared by hydrolysis of an organic silicon compound.
Claim 9
Independent Claim 115 words
A method of producing inorganic microspheres uniform in pore size which comprises injecting a silica sol containing a water-soluble organic macromolecular compound into an organic solvent through a macromolecular membrane having a hydrophobic surface and having pores substantially uniform in pore size and extending in the direction of thickness of the membrane, substantially straight through the membrane, so that a path length of each of the pores corresponds substantially to a thickness of the membrane, to form sol emulsion particles in said organic solvent, promoting a polymerization reaction to convert said sol emulsion particles to silica gel particles, which are microsphere precursors, and subjecting said silica gel particles to washing with water, drying and calcination.
Claim 10
Independent Claim 115 words
A method of producing inorganic microspheres uniform in pore size which comprises injecting a silica sol containing a water-soluble organic macromolecular compound into an organic solvent through a macromolecular membrane having a hydrophobic surface and having pores substantially uniform in pore size and extending in the direction of thickness of the membrane, substantially straight through the membrane, so that a path length of each of the pores corresponds substantially to a thickness of the membrane, to form sol emulsion particles in said organic solvent, promoting a polymerization reaction to convert said sol emulsion particles to silica gel particles, which are microsphere precursors, and subjecting said silica gel particles to washing with water, drying and calcination.
Claim 11
Independent Claim 58 words
A method of producing uniform inorganic microspheres as claimed in any of claims 1 or 8, wherein said macromolecular membrane is a membrane made of a synthetic resin including a polycarbonate or polyester, the pores in the membrane are formed by irradiation with a corpuscular beam followed by etching of the resulting defects with an aqueous alkali solution.
Claim 12
Independent Claim 45 words
A method of producing uniform inorganic microspheres as claimed in any of claims 1 or 8, wherein the macromolecular membrane is made of a synthetic resin including a polyimide, polyethylene terephthalate or a fluororesin, the pores in the membrane are formed by laser beam irradiation.
Claim 13
Dependent Claim 24 words
A method of producing uniform inorganic microspheres as claimed in claim 10, wherein the laser beam has a wavelength not longer than 355 nm.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-12-26 1998-06-27 1998-12-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-12-26 2002-06-27 2002-12-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-12-26 2006-06-27 2006-12-27 $7700.00 Window Closed / Lapsed

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