US4551510A
Expired / Lapsed
US
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Process for producing styrenic/alkenylnitrile copolymers
Assignee: Cosden Technology Inc
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Filing: 1984-08-17
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Granted: 1985-11-05
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Expires: 2004-08-17
Abstract
Abstract Disclosed is a process and apparatus for the continuous mass polymerization of styrenic and alkenylnitrile monomers. The process comprises the steps of continuously introducing a feed comprising a predetermined ratio of styrenic and alkenylnitrile monomers into a reaction vessel to produce a reaction mixture; subjecting the reaction mixture to conditions of temperature and pressure under which said monomers copolymerize to produce a styrenic/alkenylnitrile copolymer; subjecting the reaction mixture to agitation; continuously withdrawing styrenic/alkenylnitrile copolymer from the reaction vessel; and by withdrawing vapor phase from the reaction vessel in a controlled amount by varying the amount of cooled surface available for condensing the vapors, condensing the vapors by contact with the cooled surface and returning the condensate to the reaction vessel. The process and apparatus also include a novel means for devolatilizing the product copolymer.
Inventors
- 👤 Jeffrey D. Morris
- 👤 Robert A. Fuller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:30
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/0006; B01J19/0013; C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; C08F212/10; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00074; B01J2219/00105; B01J2219/00108; B01J2219/00121
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
236 words
A process for the continuous mass polymerization of styrenic and alkenylnitrile monomers to produce a styrenic/alkenylnitrile copolymer, comprising the steps of: (a) continuously introducing a feed comprising a predetermined ratio of styrenic and alkenylnitrile monomers into a reation vessel to produce a reation mixture; (b) subjecting the reaction mixture containing styrenic and alkenylnitrile monomers to conditions of temperature and pressure under which said monomers copolymerize to produce a liquid containing styrenic/alkenylnitrile copolymer and styrenic and alkenylnitrile monomers; (c) subjecting the reaction mixture to agitation sufficient to maintain a substantially uniform composition distribution and a substantially uniform temperature distribution throughout the reaction mixture; (d) continuously withdrawing at least part of a liquid containing styrenic/alkenylnitrile copolymer and styrenic and alkenylnitrile monomers from the reaction vessel; and (e) cooling the reaction mixture by withdrawing vapor phase containing vaporized styrenic and alkenylnitrile monomer from the reaction vessel to a condenser, condensing the vaporized styrenic and alkenylnitrile withdrawn from the reaction vessel by contact with a cooled condensing surface to produce a condensed monomer-containing liquid and returning at least a part of the condensed monomer-containing liquid to the reaction vessel, wherein said cooling step further comprises controlling the amount of vaporized monomers withdrawn from the reaction vessel by varying the amount of cooled surface area available for contact with the withdrawn vaporized monomers in response to the temperature in the reaction vessel, whereby the amount of vaporized monomers condensing is controlled.
Claim 2
Dependent Claim
236 words
A process for the continuous mass polymerization of styrenic and alkenylnitrile monomers to produce a styrenic/alkenylnitrile copolymer, comprising the steps of: (a) continuously introducing a feed comprising a predetermined ratio of styrenic and alkenylnitrile monomers into a reation vessel to produce a reation mixture; (b) subjecting the reaction mixture containing styrenic and alkenylnitrile monomers to conditions of temperature and pressure under which said monomers copolymerize to produce a liquid containing styrenic/alkenylnitrile copolymer and styrenic and alkenylnitrile monomers; (c) subjecting the reaction mixture to agitation sufficient to maintain a substantially uniform composition distribution and a substantially uniform temperature distribution throughout the reaction mixture; (d) continuously withdrawing at least part of a liquid containing styrenic/alkenylnitrile copolymer and styrenic and alkenylnitrile monomers from the reaction vessel; and (e) cooling the reaction mixture by withdrawing vapor phase containing vaporized styrenic and alkenylnitrile monomer from the reaction vessel to a condenser, condensing the vaporized styrenic and alkenylnitrile withdrawn from the reaction vessel by contact with a cooled condensing surface to produce a condensed monomer-containing liquid and returning at least a part of the condensed monomer-containing liquid to the reaction vessel, wherein said cooling step further comprises controlling the amount of vaporized monomers withdrawn from the reaction vessel by varying the amount of cooled surface area available for contact with the withdrawn vaporized monomers in response to the temperature in the reaction vessel, whereby the amount of vaporized monomers condensing is controlled.
Claim 3
Dependent Claim
37 words
A process as defined in claim 1, wherein said cooling step further comprises collecting a volume of the condensed monomer-containing liquid and holding same for selective introduction into the reaction vessel to produce an instantaneous cooling effect.
Claim 4
Dependent Claim
34 words
The process of claim 1 wherein varying the amount of cooled surface area available for contact with the withdrawn vaporized monomers is achieved by varying the amount of condensed monomers retained in the condenser.
Claim 5
Dependent Claim
53 words
A process as defined in claim 1, wherein said cooling step further comprises the step of recycling a portion of the condensed monomer-containing liquid to the condensing step and quenching the vaporized monomer withdrawn from the reaction vessel by passing the withdrawn vaporized monomer through a stream of the recycled condensed monomer-containing liquid.
Claim 6
Dependent Claim
20 words
A process as defined in claim 4, wherein said stream of recycled condensed monomer-containing liquid comprises a curtain-like distributed stream.
Claim 7
Dependent Claim
36 words
A process as defined in claim 4, wherein said cooling step further comprises the step of impinging said recycled condensed monomer-containing liquid against the cooled surface area to prevent accumulation of polymerized monomer on said surface.
Claim 8
Dependent Claim
28 words
A process as defined in claim 1, wherein said cooling step further comprises contacting the outside of the walls of the reaction vessel with a liquid cooling medium.
Claim 9
Dependent Claim
24 words
A process as defined in claim 1, further comprising the step of purging non-condensible components from the vapor phase withdrawn from the polymerization vessel.
Claim 10
Dependent Claim
35 words
A process as defined in claim 8, wherein said step of purging non-condensibles comprises collecting said non-condensibles in a region located above the cooled condensing surface and selectively withdrawing the non-condensibles from the collection region.
Claim 11
Dependent Claim
54 words
A process as defined in claim 9, wherein said step of selectively withdrawing non-condensibles comprises detecting the interface between the collected non-condensibles and the condensible vapors of the withdrawn vapor phase and venting the non-condensibles in response to movement of said interface to a preselected position indicating collection of a preselected volume of non-condensibles.
Claim 12
Dependent Claim
37 words
A process as defined in claim 3, wherein said cooling step further comprises directly venting said vapor phase from the reaction vessel through an unobstructed line to the inlet of a condenser positioned above the reaction vessel.
Claim 13
Dependent Claim
31 words
A process as defined in claim 1, further comprising the step of removing volatile components from the liquid containing styrenic/alkenylnitrile copolymer, styrenic monomer and alkenylnitrile monomer withdrawn from the reaction vessel.
Claim 14
Dependent Claim
92 words
A process as defined in claim 12, wherein said devolatilizing step comprises: (a) in a first stage, adjusting the ratio of styrenic to alkenylnitrile monomer in the withdrawn liquid to a ratio which is selected to provide, upon polymerization, a styrenic/alkenylnitrile copolymer having approximately the same ratio of styrenic:alkenylnitrile monomer units as the styrenic/alkenylnitrile copolymer withdrawn from the reaction vessel; and (b) in a second stage, heating the withdrawn liquid to a temperature sufficient to volatilize substantially all of the volatile components therein and separating the volatilized components from the non-volatilized copolymer.
Claim 15
Dependent Claim
19 words
A process as defined in claim 13, wherein said adjusting step comprises withdrawing a sufficient amount of alkenylnitrile monomer.
Claim 16
Dependent Claim
34 words
A process as defined in claim 14, wherein said withdrawing comprises maintaining the pressure of the first stage at a level sufficient to provide a monomer-containing vapor phase and selectively venting alkenylnitrile monomer-rich vapors.
Claim 17
Dependent Claim
61 words
A process as defined in claim 13, wherein said heating step in said second stage comprises passing the withdrawn liquid through a heat exchange apparatus and reducing the pressure in the heat exchange apparatus by an amount sufficient to cause substantial volatilization of the volatile components in the liquid sufficient to cause a froth-type two-phase flow through the heat exchange apparatus.
Claim 18
Dependent Claim
53 words
A process as defined in claim 16, wherein said separating of volatilized components in said second stage comprises passing the two-phase copolymer/volatilized components stream from the heat exchange apparatus into a separation vessel and reducing the pressure in the separation vessel to a level sufficient to maintain the volatilized components in vapor form.
Claim 19
Dependent Claim
56 words
A process as defined in claim 13, wherein said process further includes the steps of withdrawing the volatilized components from the separation vessel in the second stage, condensing the withdrawn volatilized components to produce a liquid condensate of recovered monomers, and recycling the recovered monomer liquid to the reaction vessel as part of the monomer feed.
Claim 20
Dependent Claim
35 words
A process as defined in claim 1, wherein the feed contains from about 10 to 60% by weight of acrylonitrile and from 40 to 90% by weight of styrene, based upon the total monomer content.
Claim 21
Dependent Claim
26 words
A process as defined in claim 1, wherein the feed further comprises from about 2 to 50% by weight of an inert diluent for the monomers.
Claim 22
Dependent Claim
19 words
A process as defined in claim 20, wherein said inert diluent comprises ethylbenzene, butylbenzene, benzene, toluene, xylene or cumene.
Claim 23
Dependent Claim
42 words
A process as defined in claim 1, wherein the copolymerization conditions are such as to produce a copolymerization rate of up to about 40% per hour and a total conversion of copolymer of up to about 90% based on the monomer feed.
Claim 24
Dependent Claim
24 words
A process as defined in claim 1, further comprising the step of maintaining not above an equilibrium concentration of water in the reaction vessel.
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) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |