Use of acid to stabilize indicator dyes in acrylate adhesives
US5409838A · kind A · utility
24Cited by
7References
22Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 20, 1994 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | May 20, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/10
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
The present invention provides a culture device for growing microorganisms having a self supporting substrate coated with a cold-water soluble dry powder which is a mixture of gelling agents and nutrients and a transparent cover sheet having a layer of a water-soluble pressure sensitive adhesive containing indicator dyes on a surface adjacent to the substrate wherein the improvement includes either adding a sufficient amount of a water-insoluble organic acid to the adhesive or including a sufficient amount of acrylic acid as a comonomer in the adhesive in order to inhibit or prevent a premature color change of the indicator dyes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.