US4311573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for graft copolymerization of a pre-formed substrate
Assignee: American Hospital Supply Corp
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Filing: 1980-10-08
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Granted: 1982-01-19
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Expires: 2000-10-08
Abstract
Abstract A process for modifying the surface characteristics of a pre-formed polymeric substrate to impart hydrophilicity, hydrophobicity, or other desired properties thereto, by peroxidizing the surface of the substrate and then allowing the active sites along the polymer chains to generate free radicals which induce graft polymerization of a suitable ethylenic monomer (or other ethylenically-unsaturated compound) onto the surface of the substrate is described. Such graft copolymerization is undertaken in the presence of variable valence metal ions in a reduced state under acidic conditions and at selected reaction times and relatively low temperatures, and in the presence of squarate ions (diketocyclobutenediol) to control the physical characteristics of the surface graft and to restore the metal ions to their lower valence state without at the same time producing deleterious by-products.
Inventors
- 👤 Kenneth G. Mayhan
- 👤 Robert A. Janssen
- 👤 William J. Bertrand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:36
CPC Classifications
C; C08; C08F; C08F291/00; C08F291/18; Y; Y10; Y10S; Y10S525/00; Y10S525/904
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
115 words
A process for producing a graft copolymer which comprises the graft polymerization of an ethylenically-unsaturated compound, in solution, with a substantially insoluble pre-formed solid or semi-solid polymeric substrate having peroxide groups, including hydroperoxide groups, along the polymer chains thereof, wherein the improvement comprises carrying out said polymerization in the presence of a variable valence metal ion in a reduced state capable of oxidizing to convert free hydroxyl radical to hydroxyl ion and thereby suppress homopolymerization of said monomer in said solution, said solution also containing squaric acid (diketocyclobutenediol and its ionized form) in a concentration sufficient to reduce said metal ion from its oxidized state and of complexing with said ion in its reduced state.
Claim 2
Dependent Claim
115 words
A process for producing a graft copolymer which comprises the graft polymerization of an ethylenically-unsaturated compound, in solution, with a substantially insoluble pre-formed solid or semi-solid polymeric substrate having peroxide groups, including hydroperoxide groups, along the polymer chains thereof, wherein the improvement comprises carrying out said polymerization in the presence of a variable valence metal ion in a reduced state capable of oxidizing to convert free hydroxyl radical to hydroxyl ion and thereby suppress homopolymerization of said monomer in said solution, said solution also containing squaric acid (diketocyclobutenediol and its ionized form) in a concentration sufficient to reduce said metal ion from its oxidized state and of complexing with said ion in its reduced state.
Claim 3
Dependent Claim
18 words
The process of claim 1 in which said ethylenically-unsaturated compound is water soluble and said solution is aqueous.
Claim 4
Dependent Claim
44 words
The process of claim 2 in which there is the further step of maintaining said solution at a substantially constant acidic pH and at selected reaction time and temperatures to control the depth of graft polymerization into the surface of said pre-formed polymeric substrate.
Claim 5
Dependent Claim
32 words
The process of claim 3 in which said solution is maintained at a substantially constant acidic pH by neutralizing the increase in acidity developed when said squaric acid reduces said metal ion.
Claim 6
Dependent Claim
22 words
The process of claim 4 in which said solution is maintained at a pH within the range of about 1 to 6.
Claim 7
Dependent Claim
63 words
The process of claims 1, 2 or 3 in which said pre-formed polymeric substrate is removed from said solution after graft copolymerization has occurred upon the surfaces thereof exposed to said solution, and a second pre-formed polymeric substrate having peroxide groups, including hydroperoxide groups, along the polymer chains thereof is introduced into said solution to graft copolymerize said monomer onto the surfaces thereof.
Claim 8
Dependent Claim
20 words
The process of claims 2, 3, 4 or 5 in which said solution also contains a neutral salt dissolved therein.
Claim 9
Dependent Claim
19 words
The process of claim 7 in which said salt is the salt of a strong acid and strong base.
Claim 10
Dependent Claim
30 words
The process of claim 1 in which there is the preliminary step of treating said pre-formed polymeric substrate with high energy ionizing radiation or ozonation to produce said peroxide groups.
Claim 11
Dependent Claim
138 words
A process for producing a graft copolymer which comprises the graft polymerization of a water-soluble ethylenically-unsaturated compound, in aqueous solution, with a substantially insoluble pre-formed solid or semi-solid polymeric substrate having peroxide groups, including hydroperoxide groups, along the polymer chains thereof, wherein the improvement comprises carrying out said polymerization in the presence of a variable valence metal ion in a reduced state capable of oxidizing to convert free hydroxyl radical to hydroxyl ion and thereby suppress homopolymerization of said monomer in said solution, said variable valence metal ion being selected from the group consisting of the ions of cobalt, manganese, iron, tin, molybdenum, and indium in their reduced states, said solution also containing squaric acid in a concentration sufficient to reduce said metal ion from its oxidized state and of complexing with said ion in its reduced state.
Claim 12
Dependent Claim
138 words
A process for producing a graft copolymer which comprises the graft polymerization of a water-soluble ethylenically-unsaturated compound, in aqueous solution, with a substantially insoluble pre-formed solid or semi-solid polymeric substrate having peroxide groups, including hydroperoxide groups, along the polymer chains thereof, wherein the improvement comprises carrying out said polymerization in the presence of a variable valence metal ion in a reduced state capable of oxidizing to convert free hydroxyl radical to hydroxyl ion and thereby suppress homopolymerization of said monomer in said solution, said variable valence metal ion being selected from the group consisting of the ions of cobalt, manganese, iron, tin, molybdenum, and indium in their reduced states, said solution also containing squaric acid in a concentration sufficient to reduce said metal ion from its oxidized state and of complexing with said ion in its reduced state.
Claim 13
Dependent Claim
45 words
The process of claim 10 in which there is the further step of maintaining said solution at a substantially constant acidic pH and at a selected reaction time and temperatures to control the depth of graft polymerization into the surface of said pre-formed polymeric substrate.
Claim 14
Dependent Claim
32 words
The process of claim 11 in which said solution is maintained at a substantially constant acidic pH by neutralizing the increase in acidity developed when said squaric acid reduces said metal ion.
Claim 15
Dependent Claim
22 words
The process of claim 10 in which said solution is maintained at a pH within the range of about 1 to 6.
Claim 16
Dependent Claim
66 words
The process of claims 10 or 11 in which there are the further steps of removing said pre-formed polymeric substrate from said solution after graft copolymerization has occurred upon the surfaces thereof exposed to said solution, and introducing a second pre-formed polymeric substrate having peroxide groups, including hydroperoxide groups, along the polymer chains thereof into said solution to graft copolymerize said monomer onto the surfaces thereof.
Claim 17
Dependent Claim
27 words
The process of claim 14 in which there is the further step of replenishing squaric acid in said solution as the same is consumed by said process.
Claim 18
Dependent Claim
30 words
The process of claim 12 in which there is the preliminary step of treating said pre-formed polymeric substrate with high energy ionizing radiation or ozonation to produce said peroxide groups.
Claim 19
Dependent Claim
22 words
The process of claims 9, 10 or 11 in which said salt is the salt of a strong acid and strong base.
Claim 20
Dependent Claim
30 words
The process of claim 17 in which there is the preliminary step of treating said pre-formed polymeric substrate to high energy ionizing radiation or ozonation to produce said peroxide groups.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-18 | 1985-07-20 | 1986-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-18 | 1989-07-20 | 1990-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-18 | 1993-07-20 | 1994-01-19 | $7700.00 | Window Closed / Lapsed |