Magnetic display panel

• US 4,643,684 A
• Filed: 02/27/1981
• Issued: 02/17/1987
• Est. Priority Date: 02/28/1980
• Status: Expired due to Term

• Current Assignee: Pilot Man-Nen-Hitsu Kabushiki Kaisha
• Original Assignee: Pilot Man-Nen-Hitsu Kabushiki Kaisha
• Inventors: Sato, Hiroshi, Murata, Yasuzo
• Primary Examiner(s): Skogquist, Harland S.
• Application Number:
  US06/238,794
• Time in Patent Office: 2,181 Days
• Field of Search: 346/21, 434/409
• US Class Current: 434/409
• CPC Class Codes: B43L 1/008 with magnetic action
• CPC Class Codes: G02F 1/091 based on magneto-absorption or magneto-reflection
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/24157 Filled honeycomb cells [e.g., solid substance in cavities, etc.]
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet

Abstract

A magnetic display panel in which syneresis is completely eliminated between a colorant and a dispersion medium by the simultaneous use of organic and inorganic thickener. A liquid sealing space is provided between two substrates sealed by an adhesive in which space a dispersing liquid having a yield value of at least 5 dyne/cm² is filled. The dispersing liquid is composed of fine magnetic particles, a colorant, a dispersion medium and the organic and inorganic thickeners. The organic thickener is preferably one of olefinic polymer, olefinic copolymer, wax, metal soap and dextrin fatty acid ester while inorganic thickener is preferably one of fine powder silicic acid and fine powder silicate.

Claims

1. A magnetic display panel comprising:

a liquid containing panel having a front substrate formed of a material selected from the group consisting of transparent and translucent materials and a rear substrate disposed opposite to said substrate and bonded thereto by an adhesive, a liquid sealing space being formed between said substrate; and

a dispersing liquid having a yield value of at least 5 dyne/cm² sealed in said space, said dispersing liquid comprising at least one organic thickener selected from the group consisting of olefinic polymer, olefinic copolymer, wax, metal soap and dextrin fatty acid ester, at least one inorganic thickener selected from the group consisting of fine powder silicic acid and fine powder silicate, fine magnetic particles having a low coercive force, a colorant and a dispersion medium, an image being recordable on said panel by a movable marking device having an oriented magnetic field.

2. The magnetic display panel according to claim 1 further comprising a multicell structure having a plurality of independent spaces disposed between said substrates and being bonded to said substrates by an adhesive.

3. The magnetic display panel according to claim 2 wherein said multicell structure comprises a plurality of honeycomb cores.

4. The magnetic display panel according to claim 1 or 2 wherein said fine magnetic particles having a low retention force comprise a material selected from the group consisting of black magnetite, gamma-hematite, chromium dioxide, ferrite, iron, cobalt and nickel including granulated particles thereof.

5. The magnetic display panel according to claim 1 or 2 wherein the movable marking device having an oriented magnetic field comprises one of a permanent magnet and an electromagnet.

6. The magnetic display panel according to claim 1 or 2 wherein said adhesive comprises an epoxy resin adhesive.

7. The magnetic display panel according to claim 1 or 2 wherein said adhesive comprises a polyurethane adhesive.

8. The magnetic display panel according to claim 1 or 2 wherein said adhesive comprises a vinyl adhesive.

9. The magnetic display panel according to claim 1 or 2 wherein said adhesive comprises a polyester adhesive.

10. The magnetic display panel according to claim 1 or 2 wherein said adhesive comprises an acrylic resin adhesive.

11. The magnetic display panel according to claim 1 or 2 wherein said adhesive comprises a synthetic rubber adhesive.

12. A magnetic display panel comprising:

a front substrate formed of a material selected from the group consisting of transparent and translucent materials and a rear substrate arranged opposite said front substrate, a liquid sealing space being formed between said substrates, said substrates being bonded together with an adhesive; and

a dispersing liquid having a yield value of at least 5 dyne/cm² disposed in said liquid sealing space, said dispersing liquid comprising fine magnetic particles, a colorant, a dispersion medium and a thickener, said thickener comprising an inorganic thickener and an organic thickener, display of an image being recordable on said panel by a movable marking device having an oriented magnetic field, wherein said organic thickener comprises an olefinic polymer.

13. A magnetic display panel comprising:

a front substrate formed of a material selected from the group consisting of transparent and translucent materials and a rear substrate arranged opposite said front substrate, a liquid sealing space being formed between said substrates, said substrates being bonded together with an adhesive; and

a dispersing liquid having a yield of at least 5 dyne/cm² disposed in said liquid sealing space, said dispersing liquid comprising fine magnetic particles, a colorant, a dispersion medium and a thickener, said thickener comprising an inorganic thickener and an organic thickener, display of an image being recordable on said panel by a movable marking device having an oriented magnetic field, wherein said organic thickener comprises a copolymer of an olefin and a monomer copolymerizable therewith.

14. A magnetic display panel comprising:

a front substrate formed of a material selected from the group consisting of transparent and translucent materials and a rear substrate arranged opposite said front substrate, a liquid sealing space being formed between said substrates, said substrates being bonded together with an adhesive; and

a dispersing liquid having a yield value of at least 5 dyne/cm² disposed in said liquid sealing space, said dispersing liquid comprising fine magnetic particles, a colorant, a dispersion medium and a thickener, said thickener comprising an inorganic thickener and an organic thickener, display of an image being recordable on said panel by a movable marking device having an oriented magnetic field, wherein said organic thickener comprises wax.

15. A magnetic display panel comprising:

a front substrate formed of a material selected from the group consisting of transparent and translucent materials and a rear substrate arranged opposite said front substrate, a liquid sealing space being formed between said substrates, said substrates being bonded together with an adhesive; and

a dispersing liquid having a yield value of at least 5 dyne/cm² disposed in said liquid sealing space, said dispersing liquid comprising fine magnetic particles, a colorant, a dispersion medium and a thickener, said thickener comprising an inorganic thickener and an organic thickener, display of an image being recordable on said panel by a movable marking device having an oriented magnetic field, wherein said organic thickener comprises metal soap.

16. A magnetic display panel comprising:

a front substrate formed of a material selected from the group consisting of transparent and translucent materials and a rear substrate arranged opposite said front substrate, a liquid sealing space being formed between said substrates, said substrates being bonded together with an adhesive; and

a dispersing liquid having a yield value of at least 5 dyne/cm² disposed in said liquid sealing space, said dispersing liquid comprising fine magnetic particles, a colorant, a dispersion medium and a thickener, said thickener comprising an inorganic thickener and an organic thickener, display of an image being recordable on said panel by a movable marking device having an oriented magnetic field, wherein said organic thickener comprises a dextrin fatty acid ester.