US4870145A
Expired / Lapsed
US
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Process for preparing polymeric beads
Assignee: Bausch and Lomb Inc
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Filing: 1987-09-02
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Granted: 1989-09-26
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Expires: 2007-09-02
Abstract
Abstract A process for preparing hydrophilic polymeric beads by suspension polymerization of one or more hydrophilic monomers and a cross-linking monomer in the presence of a free radical initiator and a regenerator amine at a temperature between 15° and 35° C. The beads are useful as abrasives in various cleaning compositions.
Inventors
- 👤 Richard C. Chromecek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:40
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/04; C08F2/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
114 words
The process for preparing hydrophilic polymeric beads by polymerization in an organic liquid medium of one or more hydrophilic monomers and at least one cross linking monomer in the presence of a free radical initiator and a regenerator amine, said amine being selected from the group consisting of secondary amines and tertiary amines wherein the monomers are initially dissolved in the liquid medium and wherein the the copolymer is insoluble in the liquid medium, the polymerization being maintained at a temperature from 15° to 35° C. for a period of one half to 48 hours whereby cross linked polymeric beads having an average diameter from 0.1 to 10 microns are precipitated from said solvent.
Claim 2
Dependent Claim
114 words
The process for preparing hydrophilic polymeric beads by polymerization in an organic liquid medium of one or more hydrophilic monomers and at least one cross linking monomer in the presence of a free radical initiator and a regenerator amine, said amine being selected from the group consisting of secondary amines and tertiary amines wherein the monomers are initially dissolved in the liquid medium and wherein the the copolymer is insoluble in the liquid medium, the polymerization being maintained at a temperature from 15° to 35° C. for a period of one half to 48 hours whereby cross linked polymeric beads having an average diameter from 0.1 to 10 microns are precipitated from said solvent.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the free radical initiator has a 10 hour half life temperature of 75° C. or less.
Claim 4
Dependent Claim
26 words
The process of claim 2 wherein the free radical initiator is present in an amount from 1 to 2.5 weight percent of the total monomer charge.
Claim 5
Dependent Claim
25 words
The process of claim 3, wherein the regenerator amine is present in an amount from 0.1 to 5.0 weight percent of the total monomer charge.
Claim 6
Dependent Claim
13 words
The process of claim 4 wherein the regenerator amine is a secondary amine.
Claim 7
Dependent Claim
13 words
The process of claim 4 wherein the regenerator amine is a tertiary amine.
Claim 8
Dependent Claim
25 words
The process of claim 6 wherein the solvent medium is present in an amount of 3 to 5 times the weight of the monomer charged.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein a modulus modifier monomer is added.
Claim 10
Dependent Claim
16 words
The process of claim 7 wherein one of the hydrophilic monomers present is an N-vinyl lactam.
Claim 11
Dependent Claim
20 words
The process of claim 7 wherein the reaction is carried out at a temperature from about 20° to 30° C.
Claim 12
Dependent Claim
23 words
The process of claim 7 wherein the solvent medium is selected from the group consisting of aromatic hydrocarbons, liquid alkanes and petroleum ethers.
Claim 13
Dependent Claim
13 words
The process of claim 11 wherein the solvent medium is an aromatic hydrocarbon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |