Patent US234981A successfully refreshed from Google Patents.
Patent US4425206A successfully refreshed from Google Patents.
US4425206A
Expired / Lapsed
US
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Anhydrous process for preparing amorphous chlorinated polyethylene and product thereof
Assignee: Dow Chemical Co
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Filing: 1982-12-09
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Granted: 1984-01-10
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Expires: 2002-12-09
Abstract
Abstract Amorphous, chlorinated ethylene polymers which have relatively low blocking tendencies in the absence of antiblock additives are prepared in a multi-step process. The process involves reacting porous, solid, finely divided, high density polyethylene particles with gaseous chlorine in the presence of a free radical initiator while said particles are agitated or maintained in a fluidized bed state. In a first step, addition of gaseous chlorine is started while the agitated particles are at a temperature of less than about 50 DEG Centigrade. Little, if any, chlorination takes place in the first step. In a second step, the agitated particles are chlorinated to a level of from about 5 to about 14 percent while the temperature of said particles is increased to a temperature within a temperature range of from about 50 DEG Centrigrade to about 105 DEG Centigrade. Chlorination of the agitated particles is continued in a third step wherein the temperature of said particles is increased at a certain rate up to a temperature of from about 125 DEG Centigrade to about 132 DEG Centigrade. Chlorination of the agitated particles is completed in a fourth step while the temperature of said particles is increased to a temperature in excess of about 130 DEG Centigrade but less than that temperature at which the particles tend to agglomerate. The fourth step is continued until a percent residual relative crystallinity of less than about 2 percent is obtained and a desired chlorine content is achieved. Illustrative chlorine contents are from about 30 to about 42 percent by weight of chlorinated polymer.
Inventors
- 👤 Loyd B. Hutchinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:18
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/18; C08F8/20; C08F8/22
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
309 words
An anhydrous free radical process for preparing amorphous chlorinated, solid, finely divided polyethylene particles; said process employing a free radical initiator, a flow of gaseous chlorine and agitation of the particles sufficient to expose generally all of said particles to the flow of gaseous chlorine, the process comprising a series of sequential steps: (a) starting addition of gaseous chlorine to an agitated mass of porous, finely divided polyethylene particles, the particles being exposed to a free radical initiator, while said mass is at a temperature within a temperature range of from about 25° to about 50° Centigrade; (b) continuing addition of gaseous chlorine to the agitated mass while continuing to expose the mass to a free radical initiator and while increasing the temperature of said mass over a temperature range of from about 50° Centigrade to about 105° Centigrade and maintaining the temperature within said temperature range until a level of chlorination of the agitated mass of from about 5 to about 15 percent by weight of said mass is attained; (c) continuing addition of gaseous chlorine to the agitated mass while continuing to expose the mass to a free radical initiator and while further increasing the temperature of said mass to a temperature of from about 125° Centigrade to about 132° Centigrade, said temperature being increased at a rate which is sufficiently slow to preclude sintering of the agitated mass; and (d) continuing addition of gaseous chlorine to the agitated mass while continuing to expose the mass to a free radical initiator and while further increasing the temperature of said mass to a temperature which is greater than about 130° Centigrade yet less than a temperature at which sintering of the agitated mass occurs and maintaining said temperature for a period of time sufficient to attain a predetermined level of chlorination and a predetermined level of relative crystallinity.
Claim 2
Dependent Claim
309 words
An anhydrous free radical process for preparing amorphous chlorinated, solid, finely divided polyethylene particles; said process employing a free radical initiator, a flow of gaseous chlorine and agitation of the particles sufficient to expose generally all of said particles to the flow of gaseous chlorine, the process comprising a series of sequential steps: (a) starting addition of gaseous chlorine to an agitated mass of porous, finely divided polyethylene particles, the particles being exposed to a free radical initiator, while said mass is at a temperature within a temperature range of from about 25° to about 50° Centigrade; (b) continuing addition of gaseous chlorine to the agitated mass while continuing to expose the mass to a free radical initiator and while increasing the temperature of said mass over a temperature range of from about 50° Centigrade to about 105° Centigrade and maintaining the temperature within said temperature range until a level of chlorination of the agitated mass of from about 5 to about 15 percent by weight of said mass is attained; (c) continuing addition of gaseous chlorine to the agitated mass while continuing to expose the mass to a free radical initiator and while further increasing the temperature of said mass to a temperature of from about 125° Centigrade to about 132° Centigrade, said temperature being increased at a rate which is sufficiently slow to preclude sintering of the agitated mass; and (d) continuing addition of gaseous chlorine to the agitated mass while continuing to expose the mass to a free radical initiator and while further increasing the temperature of said mass to a temperature which is greater than about 130° Centigrade yet less than a temperature at which sintering of the agitated mass occurs and maintaining said temperature for a period of time sufficient to attain a predetermined level of chlorination and a predetermined level of relative crystallinity.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein an inert fluidizing gas is added in conjunction with the gaseous chlorine.
Claim 4
Dependent Claim
44 words
The process of claim 1 wherein the free radical initiator is suitably selected from the group consisting of chemical free radical forming initiators, free radical forming radiation and a combination of free radical forming radiation and one or more chemical free radical forming initiators.
Claim 5
Dependent Claim
15 words
The process of claim 1 wherein the free radical initiator is free radical forming radiation.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein a level of chlorination of from about 20 to about 50 percent by weight of polymer is attained.
Claim 7
Dependent Claim
24 words
The process of claim 1 wherein a level of chlorination of from about 30 to about 42 percent by weight of polymer is attained.
Claim 8
Dependent Claim
21 words
The process of claim 2 wherein the inert fluidizing gas is selected from the group consisting of nitrogen and hydrogen chloride.
Claim 9
Dependent Claim
23 words
The process of claim 3 wherein the free radical forming radiation is provided by ultraviolet light having a wavelength sufficient to activate chlorine.
Claim 10
Dependent Claim
19 words
The process of claim 8 wherein the ultraviolet light has a wavelength of about 3350 to about 3650 Angstroms.
Claim 11
Dependent Claim
24 words
The process of claim 1 wherein the rate of temperature increase in step c is from about 0.25° to about 0.36° Centigrade per minute.
Claim 12
Dependent Claim
331 words
An anhydrous free radical process for preparing amorphous chlorinated, solid, finely divided polyethylene particles, said process employing free radical forming radiation, a flow of gaseous chlorine and agitation of the particles sufficient to expose generally all of said particles to the flow of gaseous chlorine, the process comprising a series of sequential steps: (a) starting addition of gaseous chlorine to an agitated mass of porous, finely divided polyethylene particles, the particles being exposed to free radical forming radiation, while said mass is at a temperature within a temperature range of from about 25° to about 50° Centigrade; (b) continuing addition of gaseous chlorine to the agitated mass while exposing said mass to free radical forming radiation, and while increasing the temperature of said mass over a temperature range of from about 50° Centigrade to about 105° Centigrade and maintaining the temperature within said temperature range until a level of chlorination of the agitated mass of from about 5 to about 15 percent by weight of said mass is attained; (c) continuing addition of gaseous chlorine to the agitated mass while exposing said mass to free radical forming radiation and while further increasing the temperature of said mass to a temperature of from about 125° Centigrade to about 132° Centigrade, said temperature being increased at a rate of from about 0.25° to about 0.32° Centigrade per minute said rate being sufficiently slow to preclude sintering of the agitated mass; and (d) continuing addition of gaseous chlorine to the agitated mass while exposing said mass to free radical forming radiation and while further increasing the temperature of said mass to a temperature which is greater than about 130° Centigrade yet less than a temperature at which sintering of the agitated mass occurs and maintaining said temperature for a period of time sufficient to attain a level of chlorination of from about 30 to about 42 percent by weight of said mass and a level of relative crystallinity of less than about 2 percent.
Claim 13
Dependent Claim
331 words
An anhydrous free radical process for preparing amorphous chlorinated, solid, finely divided polyethylene particles, said process employing free radical forming radiation, a flow of gaseous chlorine and agitation of the particles sufficient to expose generally all of said particles to the flow of gaseous chlorine, the process comprising a series of sequential steps: (a) starting addition of gaseous chlorine to an agitated mass of porous, finely divided polyethylene particles, the particles being exposed to free radical forming radiation, while said mass is at a temperature within a temperature range of from about 25° to about 50° Centigrade; (b) continuing addition of gaseous chlorine to the agitated mass while exposing said mass to free radical forming radiation, and while increasing the temperature of said mass over a temperature range of from about 50° Centigrade to about 105° Centigrade and maintaining the temperature within said temperature range until a level of chlorination of the agitated mass of from about 5 to about 15 percent by weight of said mass is attained; (c) continuing addition of gaseous chlorine to the agitated mass while exposing said mass to free radical forming radiation and while further increasing the temperature of said mass to a temperature of from about 125° Centigrade to about 132° Centigrade, said temperature being increased at a rate of from about 0.25° to about 0.32° Centigrade per minute said rate being sufficiently slow to preclude sintering of the agitated mass; and (d) continuing addition of gaseous chlorine to the agitated mass while exposing said mass to free radical forming radiation and while further increasing the temperature of said mass to a temperature which is greater than about 130° Centigrade yet less than a temperature at which sintering of the agitated mass occurs and maintaining said temperature for a period of time sufficient to attain a level of chlorination of from about 30 to about 42 percent by weight of said mass and a level of relative crystallinity of less than about 2 percent.
Claim 14
Dependent Claim
27 words
The process of claim 11 wherein the free radical forming radiation is provided by ultraviolet light having a wavelength of from about 3350 to about 3650 Angstroms.
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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) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |