# US 7,607,919 B2 · Magnetic substance display panel

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,607,919 B2
- Document ID: US7607919B2
- Status: Granted
- Kind: B2
- Application number: 10/544,643
- Filed: 2004-02-05
- Published: 2006-11-02
- Granted: 2009-10-27
- Earliest claimed: 2003-02-06
- Assignees: Kabushiki Kaisha Pilot Corporation
- Inventors: Taro Tozuka
- Web page: https://patentgrep.com/patent/US7607919B2

## CPC

- G02F 1/172: {based on a suspension of orientable dipolar particles, e.g. suspended particles displays}
- G02F 1/09: based on magneto-optical elements, e.g. exhibiting Faraday effect
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

A magnetic display panel that excels in display and erasure performance, being free from any change of writing and display performance even upon repetition of display and erasure and that facilitates inhibition of thixotropic property and specific gravity control for dispersion medium vs. magnetic display substance, etc., ensuring low toxicity and low pollution. In particular, a magnetic substance display panel comprising a dispersion with yield value composed mainly of a magnetic display substance, water and an aqueous thickener and a support holding the dispersion, characterized in that the aqueous thickener is at least one member selected from among a crosslinked acrylic acid copolymer, a crosslinked maleic anhydride copolymer, a thickening polysaccharide and a polyvinylalkylamide.

## Claims

### Claim 1

A magnetic display panel comprising:
a dispersion liquid and
a supporting member for holding said dispersion liquid,
wherein said dispersion liquid is a dispersion liquid, having a yield value, whose principal components are magnetic display materials in fine particle form, water as a dispersion medium, and a thickener for an aqueous system, and
wherein said thickener for an aqueous system comprises one or more members selected from the group consisting of a cross-linking type maleic anhydride copolymer and a polyvinyl alkyl amide.

### Claim 2 (depends on 1)

A magnetic display panel as claimed in claim 1, wherein said dispersion liquid is blended with a specific gravity adjustment agent comprising a molybdate and/or a tungstate.