US4863632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Encapsulated bleach particles for machine dishwashing compositions
Assignee: Lever Brothers Co
•
Filing: 1988-05-10
•
Granted: 1989-09-05
•
Expires: 2008-05-10
Abstract
Abstract A particle for releasing bleach is provided combining from 50 to 99.5% of a core consisting essentially of an oxidizing material and from 0.5 to 20% of a polycarboxylate coating surrounding the core. These particles are particularly useful in automatic dishwasher powder detergent compositions.
Inventors
- 👤 Michael Aronson
- 👤 Michele R. Lock
- 👤 Edward Santos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:02
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/395; C11D3/3953; C11D17/00; C11D17/0039; C11D3/3955
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
121 words
A particle for releasing bleach consisting essentially of: (i) from 50 to 99.5% by weight of said particle of a core consisting essentially of an oxidizing material having at least one reactive chlorine of bromine in its molecular structure; and (ii) from 0.5 to 20% by weight of said particle of a polycarboxylate coating which is selected from homo- and Co-polymers whose monomer units are selected from the group consisting of acrylid acid, methacrylic acid, C 1 -C 20 alkyl acrylate and methacrylate, vinyl acetate, styrene, maleic, anhyride, ethylene/maleic anhydride and mixtures thereof, said coating being free of soap and fatty acids, said coating also being water-insoluble at pH 7 but soluble in aqueous alkaline media at pH 10 or higher.
Claim 2
Dependent Claim
121 words
A particle for releasing bleach consisting essentially of: (i) from 50 to 99.5% by weight of said particle of a core consisting essentially of an oxidizing material having at least one reactive chlorine of bromine in its molecular structure; and (ii) from 0.5 to 20% by weight of said particle of a polycarboxylate coating which is selected from homo- and Co-polymers whose monomer units are selected from the group consisting of acrylid acid, methacrylic acid, C 1 -C 20 alkyl acrylate and methacrylate, vinyl acetate, styrene, maleic, anhyride, ethylene/maleic anhydride and mixtures thereof, said coating being free of soap and fatty acids, said coating also being water-insoluble at pH 7 but soluble in aqueous alkaline media at pH 10 or higher.
Claim 3
Dependent Claim
24 words
A particle according to claim 1 wherein said homopolymer is selected from the group consisting of poly(methacrylic acid), poly(acrylic acid) and their salt derivatives.
Claim 4
Dependent Claim
18 words
A particle according to claim 2 wherein said homopolymers have a molecular weight ranging from 1,000 to 200,000.
Claim 5
Dependent Claim
30 words
A particle according to claim 1 wherein said copolymer is selected from the group consisting of poly(ethylene/maleic anhydride), poly(ethylene/maleic anhydride/partial C 1 -C 20 alkyl ester), and their salt derivatives.
Claim 6
Dependent Claim
83 words
A particle according to claim 1 wherein the copolymer is selected from the group consisting of poly(styrene/C 1 -C 20 alkyl maleic acid half ester), poly(maleic anhydride/C 1 -C 20 alkyl maleic acid half ester), poly(acrylic acid/C 1 -C 20 alkyl methacrylate), poly(methacrylic acid/C 1 -C 20 alkyl acrylate), poly(acrylic acid/C 1 -C 20 alkyl acrylate), poly(methacrylic acid/C 1 -C 20 alkyl methacylate), poly(acrylic acid/C 1 -C 20 alkyl acrylate/vinyl acetate), poly(methacrylic acid/C 1 -C 20 alkyl methacrylate/vinyl acetate), and their salt derivatives.
Claim 7
Dependent Claim
20 words
A particle according to claim 5 wherein the copolymer is a poly(styrene/C 1 -C 20 alkyl maleic anhydride half ester).
Claim 8
Dependent Claim
19 words
A particle according to claim 6 wherein said copolymer has a number average molecular weight between 1,000 and 12,000.
Claim 9
Dependent Claim
23 words
A particle according to claim 6 wherein the polymer has a degree of esterification between 1% and 50% per mole of said acid.
Claim 10
Dependent Claim
21 words
A particle according to claim 6 wherein the degree of esterification ranges from 25% to 35% per mole of said acid.
Claim 11
Dependent Claim
17 words
A particle according to claim 6 wherein the alkyl group has between 2 and 8 carbon atoms.
Claim 12
Dependent Claim
23 words
A particle according to claim 6 wherein the copolymer is a butyl half ester of a 1:1 copolymer of styrene and maleic anhydride.
Claim 13
Dependent Claim
15 words
A particle according to claim 11 wherein the molecular weight of said copolymer is 2,000.
Claim 14
Dependent Claim
26 words
A particle according to claim 1 wherein the coating is a partial C 1 -C 20 alkyl ester of the copolymer of ethylene with maleic anhydride.
Claim 15
Dependent Claim
24 words
A particle according to claim 1 wherein the coating is a polymer of acrylic acid partially esterified with C 1 -C 20 alkyl groups.
Claim 16
Dependent Claim
31 words
A particle according to claim 1 wherein the oxidizing material is an alkali metal salt of a chlorine bleaching agent selected from the group consisting of dichloro-, trichloro-isocyanurate and mixtures thereof.
Claim 17
Dependent Claim
14 words
A particle according to claim 15 wherein the oxidizing material is sodium dichloroisocyanurate dihydrate.
Claim 18
Dependent Claim
25 words
A particle according to claim 1 wherein the oxidizing material is present in an amount from 85% to about 95% by weight of the particle.
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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) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |