US4363699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for stabilizing solutions of peroxidic compounds used for bleaching
Assignee: Solvay SA
•
Filing: 1980-09-04
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Granted: 1982-12-14
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Expires: 2000-09-04
Abstract
Abstract Process for stabilizing solutions of peroxidic compounds used for bleaching. At least one polymer derived from an alpha-hydroxyacrylic acid, which contains units of the formula <IMAGE> where R1 and R2 represent hydrogen or an alkyl group comprising from 1 to 3 carbon atoms which can be substituted by a hydroxyl group or a halogen atom, R1 and R2 being identical or different, and where M represents an alkali metal atom, a hydrogen atom or an ammonium group, is added to the solution as a stabilizer.
Inventors
- 👤 Jean DeCeuster
- 👤 Paul Essemaeker
- 👤 Edmond Bouillet
- 👤 Alain Decamps
- 👤 Pierre Ledoux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:22
CPC Classifications
C; C01; C01B; C01B15/00; C01B15/01; C01B15/037; C11; C11D; C11D3/00; C11D3/39; C11D3/3902; C11D3/3937; C11D3/394; D; D06; D06L; D06L4/00; D06L4/10; D06L4/12; D21; D21C; D21C9/00; D21C9/10; D21C9/16; D21C9/163
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
158 words
Process for bleaching paper pulp or cellulosic fibers by contacting the paper pulp or cellulosic fibers with a stabilized solution containing water, a peroxidic compound used for bleaching and a stabilizer, which stabilizer is at least one polymer derived from an alpha-hydroxyacrylic acid, which polymer is a homopolymer and contains units of the formula: ##STR4## where R 1 and R 2 represent hydrogen or an alkyl group comprising from 1 to 3 carbon atoms which can be substituted by a hydroxyl group or a halogen atom, R 1 and R 2 being identical or different, and where M represents a sodium or potassium atom or an ammonium group, said peroxide compound being present in an amount between 0.01 and 30% by weight relative to the weight of solvent, said polymer having an average molecular weight of between 2,000 and 800,000 and being present in an amount between 0.01 and 30% by weight relative to the weight of water.
Claim 2
Dependent Claim
158 words
Process for bleaching paper pulp or cellulosic fibers by contacting the paper pulp or cellulosic fibers with a stabilized solution containing water, a peroxidic compound used for bleaching and a stabilizer, which stabilizer is at least one polymer derived from an alpha-hydroxyacrylic acid, which polymer is a homopolymer and contains units of the formula: ##STR4## where R 1 and R 2 represent hydrogen or an alkyl group comprising from 1 to 3 carbon atoms which can be substituted by a hydroxyl group or a halogen atom, R 1 and R 2 being identical or different, and where M represents a sodium or potassium atom or an ammonium group, said peroxide compound being present in an amount between 0.01 and 30% by weight relative to the weight of solvent, said polymer having an average molecular weight of between 2,000 and 800,000 and being present in an amount between 0.01 and 30% by weight relative to the weight of water.
Claim 3
Dependent Claim
11 words
Process according to claim 1, wherein M represents a sodium atom.
Claim 4
Dependent Claim
11 words
Process according to claim 2, wherein the polymer is sodium poly-alpha-hydroxyacrylate.
Claim 5
Dependent Claim
15 words
Process according to claim 1, wherein the solution contains hydrogen peroxide as the peroxidic compound.
Claim 6
Dependent Claim
12 words
Process according to claim 1, wherein the solution contains a basic compound.
Claim 7
Dependent Claim
12 words
Process according to claim 5, wherein the basic compound is sodium hydroxide.
Claim 8
Dependent Claim
15 words
A process according to claim 1, wherein the material being bleached is a paper pulp.
Claim 9
Dependent Claim
27 words
A process according to claim 7, wherein the paper pulp is a mechanical pulp, a chemical pulp, a semi-chemical pulp, a mechanical-chemical pulp, or a thermomechanical pulp.
Claim 10
Dependent Claim
15 words
A process according to claim 1, wherein the material being bleached is a cellulosic fiber.
Claim 11
Dependent Claim
23 words
A process according to claim 9, wherein the cellulosic fiber is a jute fiber, cotton fiber, linen fiber, ramie fiber, or sisal fiber.
Claim 12
Dependent Claim
18 words
A process according to claim 9, wherein the cellulosic fiber is an artificial fiber made from regenerated cellulose.
Claim 13
Dependent Claim
17 words
A process according to claim 11, wherein the artificial fiber is rayon, viscose rayon, or cellulose acetate.
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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) | 1985-12-13 | 1986-06-14 | 1986-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-13 | 1990-06-14 | 1990-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-13 | 1994-06-14 | 1994-12-14 | $7700.00 | Window Closed / Lapsed |