Methods for producing fiber reinforced microspheres made from dispersed particle compositions

Claim 1

A method for making fiber reinforced hollow porous microspheres of 200 to 10,000 microns diameter and of 1 to 1000 microns wall thickness from a stable dispersion of a fiber and dispersed particle film forming composition, said composition comprising fibers and dispersed particles in a continuous liquid phase, wherein said fibers have a diameter of 0.5 to 10 microns and a length of 2 to 500 microns and the ratio of fiber diameter to length is 1:3 to 1:100 said method comprising feeding said fibers and dispersed particle composition and a blowing gas to a coaxial blowing nozzle, said coaxial blowing nozzle having an inner coaxial nozzle for said blowing gas and an outer coaxial nozzle for said fiber and dispersed particle composition and a coaxial blowing nozzle orifice, feeding said blowing gas to said inner nozzle, feeding said fiber and dispersed particle composition to said outer nozzle to blow and form, in the region of said coaxial blowing nozzle orifice, hollow fiber and dispersed particle composition microspheres having stable film walls, removing said hollow microspheres from the region of said coaxial blowing nozzle orifice, surface tension forces acting on said hollow microspheres to cause said hollow microspheres to form a spherical shape, treating said removed hollow microspheres to bring the fibers and dispersed particles into point to point contact and to harden them to obtain fiber reinforced hollow green microspheres, wherein said fibers are evenly distributed and are deposited between the dispersed particles to form a mat of fibers; and subjecting said fiber reinforced hollow green microspheres to a sufficiently high temperature for a sufficient period of time to remove the continuous liquid phase from the hollow green microspheres and to sinter or otherwise bond the fibers to each other and to the particles and to sinter the dispersed particles at their points of contact and to form within the walls of said hollow microspheres interconnecting voids that are continuous from the outer wall surface to the inner wall surface of the hollow microspheres, and to obtain fiber reinforced hollow porous microspheres having substantially uniform distribution of fibers in the walls, substantially uniform void content and substantially uniform distribution of the voids in the walls of the microspheres.

Claim 2

A method for making fiber reinforced hollow porous microspheres of 200 to 10,000 microns diameter and of 1 to 1000 microns wall thickness from a stable dispersion of a fiber and dispersed particle film forming composition, said composition comprising fibers and dispersed particles in a continuous liquid phase, wherein said fibers have a diameter of 0.5 to 10 microns and a length of 2 to 500 microns and the ratio of fiber diameter to length is 1:3 to 1:100 said method comprising feeding said fibers and dispersed particle composition and a blowing gas to a coaxial blowing nozzle, said coaxial blowing nozzle having an inner coaxial nozzle for said blowing gas and an outer coaxial nozzle for said fiber and dispersed particle composition and a coaxial blowing nozzle orifice, feeding said blowing gas to said inner nozzle, feeding said fiber and dispersed particle composition to said outer nozzle to blow and form, in the region of said coaxial blowing nozzle orifice, hollow fiber and dispersed particle composition microspheres having stable film walls, removing said hollow microspheres from the region of said coaxial blowing nozzle orifice, surface tension forces acting on said hollow microspheres to cause said hollow microspheres to form a spherical shape, treating said removed hollow microspheres to bring the fibers and dispersed particles into point to point contact and to harden them to obtain fiber reinforced hollow green microspheres, wherein said fibers are evenly distributed and are deposited between the dispersed particles to form a mat of fibers; and subjecting said fiber reinforced hollow green microspheres to a sufficiently high temperature for a sufficient period of time to remove the continuous liquid phase from the hollow green microspheres and to sinter or otherwise bond the fibers to each other and to the particles and to sinter the dispersed particles at their points of contact and to form within the walls of said hollow microspheres interconnecting voids that are continuous from the outer wall surface to the inner wall surface of the hollow microspheres, and to obtain fiber reinforced hollow porous microspheres having substantially uniform distribution of fibers in the walls, substantially uniform void content and substantially uniform distribution of the voids in the walls of the microspheres.

Claim 16

A method for making fiber reinforced hollow porous microspheres of 200 to 10,000 microns diameter and of 1 to 1000 microns wall thickness from a stable dispersion of a fiber and dispersed particle film forming composition, said composition comprising fibers and dispersed particles in a continuous liquid phase, wherein said fibers have a diameter of 0.5 to 10 microns and a length of 2 to 500 microns and the ratio of fiber diameter to length is 1:3 to 1:100 said method comprising feeding said fibers and dispersed particle composition and a blowing gas to a coaxial blowing nozzle, said coaxial blowing nozzle having an inner coaxial nozzle for said blowing gas and an outer coaxial nozzle for said fiber and dispersed particle composition and a coaxial blowing nozzle orifice, feeding said blowing gas to said inner nozzle, feeding said fiber and dispersed particle composition to said outer nozzle to form and blow, at said coaxial blowing nozzle orifice, hollow fiber and dispersed particle composition microspheres having stable film walls, continuously feeding said fiber and dispersed particle composition to said outer coaxial nozzle while said microspheres are being formed, directing an entraining fluid at said coaxial nozzle at an angle relative to a line drawn through the center axis of said coaxial blowing nozzle, said entraining fluid passing over and around said coaxial blowing nozzle to fluid dynamically induce a pulsating or fluctuating pressure field having periodic oscillations at the opposite or lee side of the blowing nozzle in the wake of shadow of said blowing nozzle, said entraining fluid acting on the microspheres to pinch and close-off the microspheres at a point proximate to the coaxial blowing nozzle and said entraining fluid acting to detach the microspheres from the coaxial blowing nozzle and move the microspheres away from the coaxial nozzle, surface tension forces acting on said hollow microspheres to cause said hollow microspheres to form a spherical shape, treating said detached hollow microspheres to bring the fibers and dispersed particles into contact with each other and to harden the microspheres to obtain fiber reinforced hollow green microspheres, wherein said fibers are evenly distributed and are deposited between the dispersed particles to form a mat of fibers; and subjecting said hollow green microspheres to a sufficiently high temperature for a sufficient period of time to remove the continuous liquid phase from the hollow green microspheres and to sinter or otherwise bond the fibers to each other and to the particles and to sinter the dispersed particles at their points of contact and to form within the walls of said hollow microspheres interconnecting voids that are continuous from the outer wall surface to the inner wall surface of the hollow microspheres, and to obtain hollow porous microspheres that are substantially spherical, having substantially uniform diameters, substantially uniform wall thickness, substantially uniform distribution of fibers in the walls and substantially uniform distribution of interconnecting voids in the walls of the microspheres.

Claim 17

A method for making fiber reinforced hollow porous microspheres of 200 to 10,000 microns diameter and of 1 to 1000 microns wall thickness from a stable dispersion of a fiber and dispersed particle film forming composition, said composition comprising fibers and dispersed particles in a continuous liquid phase, wherein said fibers have a diameter of 0.5 to 10 microns and a length of 2 to 500 microns and the ratio of fiber diameter to length is 1:3 to 1:100 said method comprising feeding said fibers and dispersed particle composition and a blowing gas to a coaxial blowing nozzle, said coaxial blowing nozzle having an inner coaxial nozzle for said blowing gas and an outer coaxial nozzle for said fiber and dispersed particle composition and a coaxial blowing nozzle orifice, feeding said blowing gas to said inner nozzle, feeding said fiber and dispersed particle composition to said outer nozzle to form and blow, at said coaxial blowing nozzle orifice, hollow fiber and dispersed particle composition microspheres having stable film walls, continuously feeding said fiber and dispersed particle composition to said outer coaxial nozzle while said microspheres are being formed, directing an entraining fluid at said coaxial nozzle at an angle relative to a line drawn through the center axis of said coaxial blowing nozzle, said entraining fluid passing over and around said coaxial blowing nozzle to fluid dynamically induce a pulsating or fluctuating pressure field having periodic oscillations at the opposite or lee side of the blowing nozzle in the wake of shadow of said blowing nozzle, said entraining fluid acting on the microspheres to pinch and close-off the microspheres at a point proximate to the coaxial blowing nozzle and said entraining fluid acting to detach the microspheres from the coaxial blowing nozzle and move the microspheres away from the coaxial nozzle, surface tension forces acting on said hollow microspheres to cause said hollow microspheres to form a spherical shape, treating said detached hollow microspheres to bring the fibers and dispersed particles into contact with each other and to harden the microspheres to obtain fiber reinforced hollow green microspheres, wherein said fibers are evenly distributed and are deposited between the dispersed particles to form a mat of fibers; and subjecting said hollow green microspheres to a sufficiently high temperature for a sufficient period of time to remove the continuous liquid phase from the hollow green microspheres and to sinter or otherwise bond the fibers to each other and to the particles and to sinter the dispersed particles at their points of contact and to form within the walls of said hollow microspheres interconnecting voids that are continuous from the outer wall surface to the inner wall surface of the hollow microspheres, and to obtain hollow porous microspheres that are substantially spherical, having substantially uniform diameters, substantially uniform wall thickness, substantially uniform distribution of fibers in the walls and substantially uniform distribution of interconnecting voids in the walls of the microspheres.

Claim 31

A method for making fiber reinforced hollow green microspheres of 200 to 10,000 microns diameter and of 1 to 1000 microns wall thickness from a stable dispersion of a fiber and dispersed particle film forming composition, said composition comprising fibers and dispersed particles in a continuous liquid phase, wherein said fibers have a diameter of 0.5 to 10 microns and a length of 2 to 500 microns and the ratio of fiber diameter to length is 1:3 to 1:100 said method comprising feeding said fibers and dispersed particle composition and a blowing gas to a coaxial blowing nozzle, said coaxial blowing nozzle having an inner coaxial nozzle for said blowing gas and an outer coaxial nozzle for said fiber and dispersed particle composition and a coaxial blowing nozzle orifice, feeding said blowing gas to said inner nozzle, feeding said fiber and dispersed particle composition to said outer nozzle to blow and form, in the region of said coaxial blowing nozzle orifice, hollow fiber and dispersed particle composition microspheres having stable film walls, removing said hollow microspheres from the region of said coaxial blowing nozzle orifice, surface tension forces acting on said hollow microspheres to cause said hollow microspheres to form a spherical shape, said fiber and dispersed particle composition forming the walls of said hollow microspheres and said fibers and dispersed particles being uniformly dispersed in said continuous liquid phase, treating said removed hollow microspheres to remove a portion of the continuous liquid phase to bring the dispersed particles into point to point contact and to harden them, said fibers and dispersed particles being of sufficient size and in a sufficient amount such that the fibers and dispersed particles in the walls of the hollow microspheres link up and form a relatively rigid lattice work of fibers and dispersed particles, and obtaining fiber reinforced hollow green microspheres that have substantially uniform distribution of the fibers and dispersed particles in the walls of the microspheres.

Claim 32

A method for making fiber reinforced hollow green microspheres of 200 to 10,000 microns diameter and of 1 to 1000 microns wall thickness from a stable dispersion of a fiber and dispersed particle film forming composition, said composition comprising fibers and dispersed particles in a continuous liquid phase, wherein said fibers have a diameter of 0.5 to 10 microns and a length of 2 to 500 microns and the ratio of fiber diameter to length is 1:3 to 1:100 said method comprising feeding said fibers and dispersed particle composition and a blowing gas to a coaxial blowing nozzle, said coaxial blowing nozzle having an inner coaxial nozzle for said blowing gas and an outer coaxial nozzle for said fiber and dispersed particle composition and a coaxial blowing nozzle orifice, feeding said blowing gas to said inner nozzle, feeding said fiber and dispersed particle composition to said outer nozzle to blow and form, in the region of said coaxial blowing nozzle orifice, hollow fiber and dispersed particle composition microspheres having stable film walls, removing said hollow microspheres from the region of said coaxial blowing nozzle orifice, surface tension forces acting on said hollow microspheres to cause said hollow microspheres to form a spherical shape, said fiber and dispersed particle composition forming the walls of said hollow microspheres and said fibers and dispersed particles being uniformly dispersed in said continuous liquid phase, treating said removed hollow microspheres to remove a portion of the continuous liquid phase to bring the dispersed particles into point to point contact and to harden them, said fibers and dispersed particles being of sufficient size and in a sufficient amount such that the fibers and dispersed particles in the walls of the hollow microspheres link up and form a relatively rigid lattice work of fibers and dispersed particles, and obtaining fiber reinforced hollow green microspheres that have substantially uniform distribution of the fibers and dispersed particles in the walls of the microspheres.