Moisture sensitive resistive element

• US 4,528,543 A
• Filed: 03/30/1984
• Issued: 07/09/1985
• Est. Priority Date: 07/08/1981
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sugihara, Takashi, Hijikigawa, Masaya, Miyoshi, Shuji
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Swisher, Nancy A. B.
• Application Number:
  US06/595,384
• Time in Patent Office: 466 Days
• Field of Search: 428/201, 428/913, 428/210, 338/35
• US Class Current: 338/35
• CPC Class Codes: G01N 27/121 for determining moisture content, e.g. humidity, of the fluid moisture content of the tested material G01N27/048
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

A moisture sensitive resistive element includes a substrate made of an electrically non-conductive material, first and second electrodes deposited on the substrate in a spaced relation to each other, and a moisture sensitive film deposited on the substrate covering both the first and second electrodes. The moisture sensitive film is formed by a material given by a formula: [--CH(C₆ H₄ SO₃ X)--CH₂ --]_n wherein X is any one of a hydrogen atom, metal atom, ammonium, urea, triethylenediamine, tetramethyleneguanidine and hexamethylenediamine, or formed by a mixture of the above material with a hydrophilic polymer which is any one selected from a group consisting of polyvinyl alcohol, methyl cellulose and polyamide resin.

Claims

1. The method of producing a moisture sensitive electrically resistive element capable of detecting and measuring moisture variations and content under ambient conditions ranging from 0 to 100% relative humidity which comprises:

providing a substrate made of electrically non-conductive material;

depositing first and second electrodes on said substrate in a spaced relationship to each other; and

depositing a moisture sensitive film comprising a polymeric material having a formula;

space="preserve" listing-type="equation">[--CH(C.sub.6 H.sub.4 SO.sub.3 X)--CH.sub.2 --].sub.n

wherein X is any one of a hydrogen atom, metal atom, ammonium, urea, triethylenediamine, tetramethyleneguanidine and hexamethylenediamine wherein n is qreater than 50;

such that said resulting electrically resistive element has quick response to said broad humidity change to vary its internal ohmic resistance.

2. A method of detecting and measuring moisture variations and content under ambient conditions utilizing a highly moisture sensitive electrically resistance element which comprises:

providing a highly stable moisture sensitive electrically resistive element capable of detecting and measuring moisture variations and content under ambient conditions ranging from 0 to 100% relative humidity comprising a substrate made of electrically non-conductive material, first and second electrodes superimposed on said substrate in a spaced relationship to each other and a moisture sensitive film comprising a polymeric material having a formula;

space="preserve" listing-type="equation">[--CH(C.sub.6 H.sub.4 SO.sub.3 X)--CH.sub.2 --].sub.n

wherein X is any one of a hydrogen atom, metal atom, ammonium urea, triethylenediamine, tetramethyleneguanidine and hexamethylenediamine wherein n is greater than 50; and

introducing said element into a moisture variable environment, said electrically resistive element responding quickly to said broad humidity range to vary its internal ohmic resistance.