US4628071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Emulsion copolymerization process
Assignee: SC Johnson Commercial Markets Inc
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Filing: 1985-08-16
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Granted: 1986-12-09
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Expires: 2005-08-16
Abstract
Abstract An emulsion polymer of a water insoluble vinylic monomer and an acrylic monomer is formed by precharging a portion of the acrylic monomer and thereafter adding a comonomer charge corresponding to the final desired composition of the vinylic monomer and acrylic monomer at an addition rate generally corresponding to the steady state monomers concentration. A high non-volatiles content is maintained to inhibit the acrylic monomer from partitioning into the aqueous phase.
Inventors
- 👤 Lee W. Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:02
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/12; C08F2/16; C08F2/22; C08F220/00; C08F220/02; C08F220/04; C08F220/06; Y; Y10; Y10S; Y10S526/00; Y10S526/937
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
202 words
An aqueous emulsion polymerization process for preparing homogeneous, low molecular weight alkali soluble polymer from a water insoluble vinylic monomer and acrylic acid which comprises: (a) forming an aqueous precharge consisting essentially of sufficient acrylic acid to inhibit formation of homopolymers of said water insoluble vinylic monomer and to promote formation of a homogeneous copolymer of said water insoluble vinylic monomer and acrylic acid, said precharge being initiator free; (b) adding a comonomers charge of said water insoluble vinylic monomer and acrylic acid to said acrylic acid precharge in the presence of an initiator and a chain transfer agent, wherein the weight ratio of said comonomers in said charge corresponds to a preselected ratio of said comonomers in said alkali soluble polymer and wherein the addition rate of said comonomers charge is no greater than the polymerization rate for said comonomers at a steady state condition; and wherein (1) the polymerization reaction is starved of water insoluble monomer and (2) the initiator is added to the emulsion polymerization reaction mixture immediately preceding and/or simultaneously with the comonomers charge; and (c) maintaiing a sufficient solids concentration during said polymerization reaction to reduce the tendency of acrylic acid to partition into the aqueous phase.
Claim 2
Dependent Claim
202 words
An aqueous emulsion polymerization process for preparing homogeneous, low molecular weight alkali soluble polymer from a water insoluble vinylic monomer and acrylic acid which comprises: (a) forming an aqueous precharge consisting essentially of sufficient acrylic acid to inhibit formation of homopolymers of said water insoluble vinylic monomer and to promote formation of a homogeneous copolymer of said water insoluble vinylic monomer and acrylic acid, said precharge being initiator free; (b) adding a comonomers charge of said water insoluble vinylic monomer and acrylic acid to said acrylic acid precharge in the presence of an initiator and a chain transfer agent, wherein the weight ratio of said comonomers in said charge corresponds to a preselected ratio of said comonomers in said alkali soluble polymer and wherein the addition rate of said comonomers charge is no greater than the polymerization rate for said comonomers at a steady state condition; and wherein (1) the polymerization reaction is starved of water insoluble monomer and (2) the initiator is added to the emulsion polymerization reaction mixture immediately preceding and/or simultaneously with the comonomers charge; and (c) maintaiing a sufficient solids concentration during said polymerization reaction to reduce the tendency of acrylic acid to partition into the aqueous phase.
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein from about 2% to 25% by weight of acrylic acid, based on the total weight of the monomers employed, is present in the precharge.
Claim 4
Dependent Claim
31 words
The process of claim 1 in which the amount of acrylic acid in the precharge is about 4 to 8 weight percent based on the total weight of the monomers employed.
Claim 5
Dependent Claim
22 words
The process of claim 1 in which the total monomer charge is added over a period from about 2 to 3 hours.
Claim 6
Dependent Claim
28 words
The process of claim 1 in which the weight ratio of water insoluble vinylic monomer to acrylic acid in said comonomers charge is from about 2:1 to 1:1.
Claim 7
Dependent Claim
33 words
The process of claim 1 in which the concentration of non-volatiles in the process is maintained at from about 18% to 45% by weight based on the total weight of the aqueous emulsion.
Claim 8
Dependent Claim
12 words
The process of claim 1 in which the vinylic monomer is styrene.
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) | 1989-12-08 | 1990-06-09 | 1990-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-08 | 1994-06-09 | 1994-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-08 | 1998-06-09 | 1998-12-09 | $7700.00 | Window Closed / Lapsed |