US5409838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of acid to stabilize indicator dyes in acrylate adhesives
Assignee: 3M Co
•
Filing: 1994-05-20
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Granted: 1995-04-25
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Expires: 2014-05-20
Abstract
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.
Inventors
- 👤 Peter D. Wickert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:03
CPC Classifications
C; C12; C12M; C12M23/00; C12M23/02; C12M23/04; C12M23/22; C12M23/38; C12M25/00; C12M25/06; Y; Y10; Y10T; Y10T436/00; Y10T436/10
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
81 words
In a device for growing microorganisms having a self-supporting, waterproof substrate to which is adhered a cold-water soluble powder that includes at least one gelling agent and nutrients and a transparent cover sheet having a layer of an alkyl acrylate/acrylamide adhesive containing an indicator dye applied on a surface of the cover sheet wherein the improvement comprises mixing the adhesive with a sufficient amount of a water-insoluble organic acid to inhibit or prevent substantial, premature color change of the indicator dye.
Claim 2
Dependent Claim
81 words
In a device for growing microorganisms having a self-supporting, waterproof substrate to which is adhered a cold-water soluble powder that includes at least one gelling agent and nutrients and a transparent cover sheet having a layer of an alkyl acrylate/acrylamide adhesive containing an indicator dye applied on a surface of the cover sheet wherein the improvement comprises mixing the adhesive with a sufficient amount of a water-insoluble organic acid to inhibit or prevent substantial, premature color change of the indicator dye.
Claim 3
Dependent Claim
29 words
The device of claim 1 wherein the molar ratio of the moles of organic acid to the moles of acrylamide in the adhesive is the range of about 0.5-2:1.
Claim 4
Dependent Claim
26 words
The device of claim 1 wherein the molar ratio of the moles of organic acid to the moles of acrylamide in the adhesive is about 0.5:1.
Claim 5
Dependent Claim
17 words
The device of claim 1 wherein the organic acid is a C 8 -C 18 organic acid.
Claim 6
Dependent Claim
12 words
The device of claim 1 wherein the organic acid is stearic acid.
Claim 7
Dependent Claim
82 words
In a device for growing microorganisms having a self-supporting, waterproof substrate to which is adhered a cold-water soluble powder that includes at least one gelling agent and nutrients and a transparent cover sheet having a layer of a water-insoluble alkyl acrylate/acrylic acid adhesive containing an indicator dye applied on a surface of the cover sheet wherein the improvement comprises including less than 4 wt. % acrylic acid in the adhesive to inhibit or prevent significant, premature color change of the indicator dye.
Claim 8
Dependent Claim
82 words
In a device for growing microorganisms having a self-supporting, waterproof substrate to which is adhered a cold-water soluble powder that includes at least one gelling agent and nutrients and a transparent cover sheet having a layer of a water-insoluble alkyl acrylate/acrylic acid adhesive containing an indicator dye applied on a surface of the cover sheet wherein the improvement comprises including less than 4 wt. % acrylic acid in the adhesive to inhibit or prevent significant, premature color change of the indicator dye.
Claim 9
Dependent Claim
28 words
The device of claim 6 wherein the adhesive comprises less than about 2 wt. % acrylic acid and more than about 98 wt. % of an alkyl acrylate.
Claim 10
Dependent Claim
12 words
The device of claim 7 wherein the alkyl acrylate is isooctyl acrylate.
Claim 11
Dependent Claim
54 words
A process for increasing the stability of an indicator dye adhered to a substrate with a pressure sensitive alkyl acrylate/acrylamide adhesive comprising the step of mixing the adhesive with a sufficient amount of water-insoluble organic acid to inhibit or prevent undesired reduction of the indicator which causes a premature color change of the indicator.
Claim 12
Dependent Claim
54 words
A process for increasing the stability of an indicator dye adhered to a substrate with a pressure sensitive alkyl acrylate/acrylamide adhesive comprising the step of mixing the adhesive with a sufficient amount of water-insoluble organic acid to inhibit or prevent undesired reduction of the indicator which causes a premature color change of the indicator.
Claim 13
Dependent Claim
30 words
The process of claim 9 wherein the molar ratio of the moles of organic acid to the moles of acrylamide in the adhesive is in the range of about 0.5-2:1.
Claim 14
Dependent Claim
26 words
The process of claim 9 wherein the molar ratio of the moles of organic acid to the moles of acrylamide in the adhesive is about 0.5:1.
Claim 15
Dependent Claim
17 words
The process of claim 9 wherein the organic acid is a C 8 -C 18 organic acid.
Claim 16
Dependent Claim
12 words
The process of claim 9 wherein the organic acid is stearic acid.
Claim 17
Dependent Claim
62 words
A process for increasing the stability of a reduction-sensitive indicator dye adhered to a substrate with a water-insoluble isooctyl acrylate-based pressure sensitive adhesive comprising the step of copolymerizing isooctyl acrylate with about 4 wt. % acrylic acid to provide a pressure sensitive adhesive which will inhibit or prevent undesired reduction of the indicator which causes a premature color change of the indicator.
Claim 18
Dependent Claim
62 words
A process for increasing the stability of a reduction-sensitive indicator dye adhered to a substrate with a water-insoluble isooctyl acrylate-based pressure sensitive adhesive comprising the step of copolymerizing isooctyl acrylate with about 4 wt. % acrylic acid to provide a pressure sensitive adhesive which will inhibit or prevent undesired reduction of the indicator which causes a premature color change of the indicator.
Claim 19
Dependent Claim
24 words
The process of claim 14 wherein the adhesive comprises about 2 wt. % acrylic acid and about 98 wt. % of an alkyl acrylate.
Claim 20
Dependent Claim
12 words
The process of claim 14 wherein the alkyl acrylate is isooctyl acrylate.
Claim 21
Independent Claim
42 words
A device capable of growing microorganisms thereon comprising a cover sheet, a gelling agent, and an alkyl acrylate/acrylamide adhesive containing an indicator dye and a water-insoluble organic acid, wherein the cover sheet has an a* chromaticity value of less than about +1.20.
Claim 22
Independent Claim
42 words
A device capable of growing microorganisms thereon comprising a cover sheet, a gelling agent, and an alkyl acrylate/acrylamide adhesive containing an indicator dye and a water-insoluble organic acid, wherein the cover sheet has an a* chromaticity value of less than about +1.20.
Claim 23
Dependent Claim
30 words
The device of claim 17 wherein the molar ratio of the moles of organic acid to the moles of acrylamide in the adhesive is in the range of about 0.5-2:1.
Claim 24
Dependent Claim
26 words
The device of claim 17 wherein the molar ratio of the moles of organic acid to the moles of acrylamide in the adhesive is about 0.5:1.
Claim 25
Independent Claim
52 words
A device capable of growing microorganisms thereon comprising a cover sheet, a gelling agent, a water-insoluble adhesive comprising less than about 4 wt. % acrylic acid and more than about 96 wt. % isooctyl acrylate, and indicator dye, wherein the cover sheet has an a* chromaticity value of less than about +1.20.
Claim 26
Independent Claim
52 words
A device capable of growing microorganisms thereon comprising a cover sheet, a gelling agent, a water-insoluble adhesive comprising less than about 4 wt. % acrylic acid and more than about 96 wt. % isooctyl acrylate, and indicator dye, wherein the cover sheet has an a* chromaticity value of less than about +1.20.
Claim 27
Dependent Claim
22 words
The device of claim 20 wherein the water-insoluble adhesive comprises about 2 wt. % acrylic acid and 98 wt. % isooctyl acrylate.
Claim 28
Dependent Claim
21 words
The device of claim 20 wherein the pH value of the gelling agent and water-insoluble adhesive is greater than about 6.35.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-04-24 | 1998-10-24 | 1999-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-24 | 2002-10-24 | 2003-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-24 | 2006-10-24 | 2007-04-25 | $7700.00 | Window Closed / Lapsed |