Sensor and a method of making the same

Patent metadata

Field	Value
Publication number	US-9745436-B2
Application number	US-201314653117-A
Country	US
Kind code	B2
Filing date	Nov 27, 2013
Priority date	Jan 15, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

The present invention provides a sensor having an improved sensitivity and precision, which is lighter and more flexible than conventional sensors, and a method of making the sensor. The present invention relates to a sensor comprising a resin foam containing a magnetic filler, and a magnetic sensor that detects a magnetic change caused by a deformation of the resin foam, wherein the resin foam is a polyurethane resin foam that comprises a polyisocyanate component, an active hydrogen component, a catalyst and a foam stabilizer, and wherein the resin foam has a hardness change (H 1 -H 60 ) of 0 to 10 between a JIS-C hardness (H 1 ) in one second after contact with a pressure surface of a hardness tester and a JIS-C hardness (H 60 ) in 60 seconds after the contact.

First claim

What is claimed is:

1. A sensor comprising:
a resin foam containing a plurality of bubbles and a magnetic filler, and
a magnetic sensor that detects a change in magnetic field caused by a deformation of the resin foam,
wherein the resin foam is a polyurethane resin foam that comprises a polyisocyanate component, an active hydrogen component, a catalyst and a foam stabilizer, and
wherein the resin foam has a hardness change (H 1 -H 60 ) of 0 to 10 between a JIS-C hardness (H 1 ) in one second after contact with a pressure surface of a hardness tester and a JIS-C hardness (H 60 ) in 60 seconds after the contact.

2. The sensor according to claim 1 , wherein the resin foam has a specific gravity of 0.3 to 1.0 and an average cell diameter of 50 to 500 μm.

3. The sensor according to claim 1 , wherein an amount of the foam stabilizer is within the range of 1 to 10 parts by mass per 100 parts by mass of the resin foam.

4. A method of making a sensor comprising a polyurethane resin foam containing a plurality of bubbles and a magnetic filler and a magnetic sensor, the method comprises the steps of:
(I) forming the polyurethane resin foam containing the plurality of bubbles and the magnetic filler comprising the steps of;
(i) forming an isocyanate group-containing urethane prepolymer from a polyisocyanate component and an active hydrogen component,
(ii) preliminary stirring an active hydrogen component, a catalyst and a magnetic filler to form a magnetic filler dispersion,
(iii) adding a foam stabilizer to the isocyanate group-containing urethane prepolymer to vigorously stir it under a non-reactive gas atmosphere such that it incorporates bubbles therein as a primary stirring step,
(iv) further adding the magnetic filler dispersion thereto and stirring it as a secondary stirring step to prepare a bubble dispersed urethane composition containing the magnetic filler,
(v) molding the bubble dispersed urethane composition into a desired shape and then curing it to prepare an urethane resin foam containing the magnetic filler, and
(vi) magnetizing the urethane resin foam to form a magnetic urethane resin foam, and

(II) placing the polyurethane resin foam containing the plurality of bubbles and the magnetic filler on a surface of the magnetic sensor.

5. The sensor according to claim 1 , wherein the sensor is a tactile sensor or a bending sensor.

6. The sensor according to claim 1 , wherein the magnetic filler is a metal powder or metal oxide powder which can have a magnetic force by magnetization.

7. The sensor according to claim 1 , wherein the magnetic sensor is selected from the group consisting of a semiconductor compound magnetoresistive element, an anisotropic magnetoresistive element, giant magnetoresistive element, a tunnel magnetoresistive element, a Hall element, an inductor, MI element, and a flux gate sensor.

8. The method of making a sensor according to claim 4 , wherein the sensor is a tactile sensor or a bending sensor.

9. The method of making a sensor according to claim 4 , wherein the magnetic filler is a metal powder or metal oxide powder which can have a magnetic force by magnetization.

10. The method of making a sensor according to claim 4 , wherein the desired shape is selected from the group consisting of a spherical shape, a flat shape, a needle shape and a columnar shape.

11. The method of making a sensor according to claim 4 , wherein the magnetic sensor is selected from the group consisting of a semiconductor compound magnetoresistive element, an anisotropic magnetoresistive element, giant magnetoresistive element, a tunnel magnetoresistive element, a Hall element, an inductor, MI element, and a flux gate sensor.

Assignees

• Toyo Tire & Rubber Co

Inventors

• Shigeto Junichi
• Fukuda Takeshi
• Anzai Hiroyuki
• Luo Zhiwei

Classifications

• C08J2201/022

  premixing or pre-blending a part of the components of a foamable composition, e.g. premixing the polyol with the blowing agent, surfactant and catalyst and only adding the isocyanate at the time of foaming · CPC title

• C08J9/0095

  Mixtures of at least two compounding ingredients belonging to different one-dot groups · CPC title

• C08G18/10

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08J9/0066

  Use of inorganic compounding ingredients · CPC title

• C08J2207/00

  Foams characterised by their intended use · CPC title