Process for patterning powders into thick layers

A process for applying a discontinuous coating of particulates to a surface comprising the steps of:

• a) providing a support,
• b) placing a bed of non-adhered particles on said support, said particles being capable of being moved by an electric field of less than 100 KV/cm,
• c) placing a mask with a first and second surface over said bed of non-adhered particles, said mask having holes which pass from said first to said second surface, said first surface facing said bed of non-adhered particles without said mask touching said bed of non-adhered particles, said holes in said mask having a size which would allow passage of individual particles from said bed of non-adhered particles through said holes,
• d) placing a receptor material capable of at least temporarily retaining an electric charge adjacent said second surface of said mask, which second surface faces away from said bed of non-adhered particles,
• e) applying an electrical charge to said receptor material which is at least temporarily retained by said receptor material,
• f) applying an electrical field between said mask and said support, said electrical field being of at least sufficient strength to cause individual particles from said bed of non-adhered particles to move off said support and impact said mask,
• g) allowing some of said individual particles which move off said support to enter said holes in said mask and contact said receptor material, and
• h) said contact by individual particles to said receptor material causing at least some of said particles contacting said receptor material to adhere to said receptor material at least by charge attraction of said individual particles to charge on said receptor material, wherein a conductive element is placed against a side of said receptor material which faces away from said first substrate after step h.

A process for applying a discontinuous coating of particulates to a surface comprising the steps of:

• a) providing a support,
• b) placing a bed of non-adhered particles on said support said particles being capable of being moved by an electric field of less than 100 KV/cm.
• c) placing a mask with a first and second surface over said bed of non-adhered particles, said mask having holes which pass from said first to said second surface, said first surface facing said bed of non-adhered particles without said mask touching said bed of non-adhered particles, said holes in said mask having a size which would allow passage of individual particles from said bed of non-adhered particles through said holes,
• d) placing a receptor material capable of at least temporarily retaining an electric charge adjacent said second surface of said mask, which second surface faces away from said bed of non-adhered particles,
• e) applying an electrical charge to said receptor material which is at least temporarily retained by said receptor material,
• f) applying an electrical field between said mask and said support, said electrical field being of at least sufficient strength to cause individual particles from said bed of non-adhered particles to move off said support and impact said mask,
• g) allowing some of said individual particles which move off said support to enter said holes in said mask and contact said receptor material, and
• h) said contact by individual particles to said receptor material causing at least some of said particles contacting said receptor material to adhere to said receptor material at least by charge attraction of said individual particles to charge on said receptor material, wherein said receptor material comprises organic polymeric film.

A process for applying a discontinuous coating of particulates to a surface comprising the step of:

• a) providing a support,
• b) placing a bed of non-adhered particles on said support, said particles being capable of being moved by an electric field of less than 100 KV/cm.
• c) placing a mask with a first and second surface over said bed of non-adhered particles, said mask having holes which pass from said first to said second surface, said first surface facing said bed of non-adhered particles without said mask touching said bed of non-adhered particles, said holes in said mask having a size which would allow passage of individual particles from said bed of non-adhered particles through said holes,
• d) placing a receptor material capable of at least temporarily retaining an electric charge adjacent said second surface of said mask, which second surface faces away from said bed of non-adhered particles,
• e) applying an electrical charge to said receptor material which is at least temporarily retained by said receptor material,
• f) applying an electrical field between said mask and said support, said electrical field being of at least sufficient strength to cause individual particles from said bed of non-adhered particles to move off said support and impact said mask,
• g) allowing some of said individual particles which move off said support to enter said holes in said mask and contact said receptor material, and
• h) said contact by individual particles to said receptor material causing at least some of said particles contacting said receptor material to adhere to said receptor material at least by charge attraction of said individual particles to charge on said receptor material, wherein said receptor material comprises organic polymeric film, wherein said electrical field applied in step f) causes particles with an electrical charge opposite that of the charge provided on said receptor material to move towards said receptor material, and causes particles with an electrical charge similar to that provided on said receptor material to move away from said receptor material, wherein the movement of particles towards and away from said receptor material produces a cloud of moving particles between said support and said mask, wherein the thickness of individual segments of said pattern of particles have thicknesses of at least five diameters of particles, and wherein said particles have an average diameter of between 5 micrometers and 5 millimeters and said particles have an electrical resistivity of less than 10.sup.+10 ohm-centimeters.

A process for applying a discontinuous coating of particulates to a surface comprising the steps of:

• a) providing a support,
• b) placing a bed of non-adhered particles on said support, said particles being capable of being moved by an electric field of less than 100 KV/cm,
• c) placing a mask with a first and second surface over said bed of non-adhered particles, said mask having holes which pass from said first to said second surface, said first surface facing said bed of non-adhered particles without said mask touching said bed of non-adhered particles, said holes in said mask having a size which would allow passage of individual particles from said bed of non-adhered particles through said holes,
• d) placing a receptor material capable of at least temporarily retaining an electric charge in contact with said second surface of said mask, which second surface faces away from said bed of non-adhered particles,
• e) applying an electrical charge to said receptor material which is at least temporarily retained by said receptor material,
• f) applying an electrical field between said mask and said support, said electrical field being of at least sufficient strength to cause individual particles from said bed of non-adhered particles to move off said support and impact said mask,
• g) allowing some of said individual particles which move off said support to enter said holes in said mask and contact said receptor material, and
• h) said contact by individual particles to said receptor material causing at least some of said particles contacting said receptor material to adhere to said receptor material at least by charge attraction of said individual particles to charge on said receptor material wherein said particles comprise a core of material having a conductivity and a shell of greater conductivity than the conductivity of said core.

A process for applying a discontinuous coating of multiple layers of particles to a surface comprising the steps of:

• a) providing a support,
• b) placing a bed of non-adhered particles on said support, said particles being capable of being moved by an electric field of less than 100 KV/cm,
• c) placing a mask with a first and second surface with holes in the mask over said bed of non-adhered particles, said first surface facing said bed of non-adhered particles without said mask touching said bed of non-adhered particles, said holes in said mask having a size which would allow passage of individual particles from said bed of non-adhered particles through said holes,
• d) placing a receptor material capable of at least temporarily retaining an electric charge in contact with said second surface of said mask, which second surface faces away from said bed of non-adhered particles,
• e) applying an electrical charge to said receptor material which is at least temporarily retained by said receptor material,
• f) applying an electrical field between said mask and said support, said electrical field being of at least sufficient strength to cause individual particles from said bed of non-adhered particles to move off said support and impact said mask,
• g) allowing some of said individual particles which move off said support to enter said holes in said mask and contact said receptor material, and
• h) said contact by individual particles to said receptor material causing at least some of said particles contacting said receptor material to adhere to said receptor material only by charge attraction of said individual particles to charge on said receptor material.

A process for applying a discontinuous coating of particles to a surface comprising the steps of:

• a) providing a support,
• b) placing a bed of non-adhered particles on said support, said particles being capable of being moved by an electric field of less than 100 KV/cm,
• c) placing a mask with a first and second surface with holes in the mask over said bed of non-adhered particles, said first surface facing said bed of non-adhered particles without said mask touching said bed of non-adhered particles, said holes in said mask having a size which would allow passage of individual particles from said bed of non-adhered particles through said holes,
• d) placing a receptor material capable of at least temporarily retaining an electric charge in contact with said second surface of said mask, which second surface faces away from said bed of non-adhered particles,
• e) applying an electrical charge to said receptor material which is at least temporarily retained by said receptor material,
• f) applying an electrical field between said mask and said support, said electrical field being of at least sufficient strength to cause individual particles from said bed of non-adhered particles to move off said support and impact said mask,
• g) allowing some of said individual particles which move off said support to enter said holes in said mask and contact said receptor material, and
• h) said contact by individual particles to said receptor material causing at least some of said particles contacting said receptor material to adhere to said receptor material at least by charge attraction of said individual particles to charge on said receptor material.