US3980587A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stripper composition
Assignee: GT Schjeldahl Co
•
Filing: 1974-08-16
•
Granted: 1976-09-14
•
Expires: 1994-08-16
Abstract
Abstract An aqueous solution for alkaline stripping of metallic surfaces having a resist coating on at least a portion of the surface thereof, the resist coating normally being based upon polyvinyl chloride, such as polyvinyl chloride contained in a base emulsion for a photo resist material. The alkaline stripper solution is based upon a mixture of potassium hydroxide and ammonium hydroxide, together with a chelating agent consisting of the sodium salts of ethylenediaminetetraacetic acid, acetic acid, and ethylene glycol monobutyl ether.
Inventors
- 👤 Terrence P. Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:42
CPC Classifications
C; C11; C11D; C11D7/00; C11D7/02; C11D7/04; C11D7/06; C11D3/00; C11D3/16; C11D3/26; C11D3/33
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
120 words
The method of stripping a resist coating from the surface of a metallic surface, wherein the resist coating consists essentially of polyvinyl chloride, which method consists essentially of exposing said resist coating to an aqueous working solution of a concentrate, wherein the concentrate has a composition as follows: ______________________________________
Component Parts by Weight
______________________________________
Alkaline stripper 15 to 35
Sodium salt of ethylenediamine-
tetraacetic acid selected
from di, tri, and tetrasodium salts
of ethylenediaminetetraacetic
acid and mixtures
thereof 0.5 to 1.5
Acetic acid 4 to 12
Ethylene glycol monobutyl ether
30 to 100
______________________________________ and wherein said concentrate is dispersed in aqueous solution in an amount ranging from between about 10 lbs. per gallon to about 30 lbs. per gallon.
Claim 2
Independent Claim
120 words
The method of stripping a resist coating from the surface of a metallic surface, wherein the resist coating consists essentially of polyvinyl chloride, which method consists essentially of exposing said resist coating to an aqueous working solution of a concentrate, wherein the concentrate has a composition as follows: ______________________________________
Component Parts by Weight
______________________________________
Alkaline stripper 15 to 35
Sodium salt of ethylenediamine-
tetraacetic acid selected
from di, tri, and tetrasodium salts
of ethylenediaminetetraacetic
acid and mixtures
thereof 0.5 to 1.5
Acetic acid 4 to 12
Ethylene glycol monobutyl ether
30 to 100
______________________________________ and wherein said concentrate is dispersed in aqueous solution in an amount ranging from between about 10 lbs. per gallon to about 30 lbs. per gallon.
Claim 3
Dependent Claim
28 words
The method as defined in claim 1 being particularly characterized in that said alkaline stripper component ratio in said concentrate is approximately 30:1 potassium hydroxide to ammonium hydroxide.
Claim 4
Dependent Claim
57 words
The method as defined in claim 1 being particularly characterized in that said concentrate formulation is as follows: __________________________________________________________________________
Component Parts by Weight
__________________________________________________________________________
Alkaline stripper 19
Sodium salt of ethylenediaminetetraacetic acid selected
from di, tri, and tetrasodium salts
of ethylenediaminetetraacetic acid and mixtures thereof
1
Acetic acid 8
Ethylene glycol monobutyl ether
50 to 55.
__________________________________________________________________________
References Cited (Backward Citations)
CA536441A
Cited
US2662837A
Cited
US3080262A
Cited
US3391084A
Cited
US3553143A
Cited
US3551204A
Cited
US3839234A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |