Paste for NFC magnetic sheet, method of preparing the same, and NFC magnetic sheet

Patent metadata

Field	Value
Publication number	US-9570218-B2
Application number	US-201314416143-A
Country	US
Kind code	B2
Filing date	Aug 8, 2013
Priority date	Aug 29, 2012
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A paste for an NFC magnetic sheet is provided, which comprises: a magnetic powder; an organic carrier; and a nanoscale alumina powder; wherein a weight ratio of the nanoscale alumina powder to the magnetic powder ranges from about 0.0005 to about 0.005. A method of preparing the paste for the NFC magnetic sheet and an NFC magnetic sheet are also provided.

First claim

What is claimed is:

1. A paste for an NFC magnetic sheet, comprising:
a magnetic powder;
an organic carrier in a form of a mixture of a plurality of materials; and
a nanoscale alumina powder;
wherein the magnetic powder and the nanoscale alumina powder is uniformly mixed in the mixture of the organic carrier, a weight ratio of the nanoscale alumina powder to the magnetic powder ranges from about 0.0005 to about 0.005, and a weight ratio of a summation of the magnetic powder and the nanoscale alumina powder to the organic carrier ranges from about 1 to about 1.5.

2. The paste of claim 1 , wherein:
the magnetic powder is a FeSiAl-based magnetic alloy.

3. The paste of claim 1 , wherein the magnetic powder has a thickness in the range of about 1 μm to about 5 μm, an aspect ratio in the range of about 1.5 to about 6, an average particle size in the range of about 40 μm to about 60 μm, and a specific surface area of about 0.8 m 2 /g.

4. The paste of claim 1 , wherein the organic carrier comprises a solvent, an adhesive, a dispersant, a plasticizer and a defoamer; and based on the total weight of the organic carrier, the organic carrier comprises about 75 wt % to about 85 wt % of the solvent, about 15 wt % to about 20 wt % of the adhesive, about 0.1 wt % to about 1 wt % of the dispersant, about 1 wt % to 5 wt % of the plasticizer, and about 0.1 wt % to 1 wt % of the defoamer.

5. The paste of claim 1 , wherein the nanoscale alumina powder is .alpha.-alumina with a purity of more than about 99%.

6. The paste of claim 1 , wherein the nanoscale alumina powder is a spherical powder with a particle size of about 10 nm to about 50 nm and a specific surface area of about 90 m 2 /g to about 130 m 2 /g.

Assignees

• Byd Co Ltd

Inventors

• Li Hua
• Wang Shaolong

Classifications

• H01F1/01 Primary

  of inorganic materials (H01F1/44 takes precedence) · CPC title

• B32B2250/00

  Layers arrangement · CPC title

• H01F41/14

  for applying magnetic films to substrates · CPC title

• C09J7/00

  Adhesives in the form of films or foils · CPC title

• Y10T428/2848

  Three or more layers · CPC title