Multilayer chemical analysis member having an outer waterproof layer

• US 4,631,174 A
• Filed: 04/02/1985
• Issued: 12/23/1986
• Est. Priority Date: 05/02/1978
• Status: Expired due to Fees

• Current Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kondo, Asaji
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/718,976
• Time in Patent Office: 630 Days
• Field of Search: 435/805, 436/810, 422/56
• US Class Current: 422/423
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

Chemical analysis sheets comprising a reagent layer, a porous spreading layer and a cover layer provided with a small opening are disclosed. The cover layer prevents rapid evaporation of moisture to ensure a complete reaction between the chemical reagent and the ingredient tested for.

Claims

1. A multilayer chemical analysis member comprising

a waterproof layer having a thickness of 8 microns to 1 mm and provided with at least one opening having a size of about 30 microns to about 4 mm in diameter for application of a sample liquid to be tested;

a porous spreading layer;

a chemical reagent layer comprising a chemical reagent in a hydrophilic or hydrophobic medium, said reagent being capable of reacting with a test material in said sample liquid; and

a support layer,

all of said layers being bonded together in a unified structure.

2. The multilayered chemical analysis member of claim 1, wherein said porous spreading layer is made of a fibrous material, a non-fibrous material, a micro-porous membrane filter or a polymer film filled with finely divided powder particles.

3. The multilayered chemical analysis member of claim 1, wherein said opening in said waterproof layer is a polygonal hole or a circular hole.

4. The multilayered chemical analysis member of claim 1, wherein said at least one opening comprises a plurality of small apertures each with a diameter of about 30 microns to about 0.5 mm and located within a circular area of about 1 mm to 5 mm in diamet.

5. The multilayered chemical analysis member of claim 1, wherein said waterproof layer is a waterproof film bonded to said porous spreading layer with an adhesive.

6. The multilayered chemical analysis member of claim 5, wherein said adhesive is a pressure sensitive adhesive.

7. The multilayered chemical analysis member of claim 1, wherein said waterproof layer is a waterproof adhesive film with an adhesive layer on one surface thereof.

8. The multilayered chemical analysis member of claim 7, wherein said adhesive layer is a layer of a pressure sensitive adhesive.

9. The multilayered chemical analysis member of claim 1, wherein said opening in said waterproof layer is an asterisk shaped cut, a cross cut or a linear slit.