Moisture indicators for the absorbent capacity of a desiccant

• US 6,655,315 B1
• Filed: 01/29/2002
• Issued: 12/02/2003
• Est. Priority Date: 07/30/1999
• Status: Expired due to Term

• Current Assignee: Levosil S.p.A.
• Original Assignee: Levosil S.p.A.
• Inventors: Gattiglia, Marco
• Primary Examiner(s): Fulton, Christopher W.
• Assistant Examiner(s): Hoolahan, Amanda J
• Application Number:
  US10/048,161
• Time in Patent Office: 672 Days
• Field of Search: 116/206, 116/400, 116/DIG.41, 73/73
• US Class Current: 116/206
• CPC Class Codes: B01J 20/046 containing halogens, e.g. halides
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/12 Naturally occurring clays or bleaching earth
• CPC Class Codes: B01J 20/18 Synthetic zeolitic molecular sieves
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 2220/49 Materials comprising an indicator, e.g. colour indicator, pH-indicator
• CPC Class Codes: G01N 31/222 for investigating moisture content
• CPC Class Codes: Y10S 116/41 Color comparison

Abstract

Moisture indicators comprising, as active principle, copper chloride or another salt capable of releasing Cu⁺⁺ and Cl⁻ ions, and synergistic salts containing chloride ions, which may be hygroscopic on a suitable support. Depending on the application, the support may be amorphous silica or silica gel; a solid paper support for making a moisture-indicating label; or a bentonite or calcium sulphate for making pellets by mechanical pressing.

Claims

1. Moisture indicator comprising a support coloured with copper chloride or one or more salts capable of releasing Cu⁺⁺ ions and Cl⁻

ions, and one or more metal chlorides or synergistic hygroscopic salt.

2. Moisture indicator according to claim 1, in which said support is a desiccant material.

3. Moisture indicator according to claim 1, in which said support is amorphous silica or silica gel.

4. Moisture indicator according to claim 1, in which said support is a paper label, or alternatively is a natural fabric, a nonwoven fabric.

8. Moisture indicator according to claim 1, in which the synergistic hygroscopic salts are selected from bromides, dichromates, nitrates and sulfates.

9. Moisture indicator according to claim 1, in which the synergistic hygroscopic salts are selected from magnesium chloride, lithium chloride, sodium chloride, calcium, chloride, potassium chloride, barium chloride, ferric chloride, potassium nitrate, calcium nitrate, potassium acetate, magnesium nitrate, sodium sulphate, sodium bromide, potassium dichromate.

5. Moisture indicator comprising a support coloured with copper chloride or one or more salts capable of releasing Cu⁺⁺ ions and Cl⁻

ions, and one or more metal chlorides or synergistic hygroscopic salt,

wherein said support consists of bentonites of fine particle size or calcium sulphate, molecular sieves, fossil flour, diatomaceous earth or alumina.

6. Moisture indicator according to claim 5, characterized in that it is in the form of moisture-indicating pellets.

7. Moisture indicator according to claim 5, characterized in that it is in the form of figurines or artistic manufactured products.

10. Moisture indicator comprising a support coloured with copper chloride or one or more salts capable of releasing Cu⁺⁺ ions and Cl⁻

ions, and one or more metal chlorides or synergistic hygroscopic salt,

wherein said hygroscopic salts are in amounts not greater than 30 times the amount of copper chloride.

11. A moisture indicator comprising:

at least one salt capable of releasing Cu⁺⁺ ions and Cl⁻

ions and being between 0.1% and 1.5% by weight of the moisture indicator;

at least one of a metal chloride and a synergistic hygroscopic salt; and

a support, said at least one salt and said synergistic salt coloring said support.