Patent US4151135A successfully refreshed from Google Patents.
US4151135A
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US
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Processes for producing dry powders from tacky polymers via dispersion of same in water with dispersants convertible to parting agents
Assignee: Millennium Petrochemicals Inc
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Filing: 1977-08-15
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Granted: 1979-04-24
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Expires: 1997-08-15
Abstract
Abstract Processes are disclosed for comminuting and recovering as dry powders tacky ethylene-vinyl acetate (EVA) copolymers and tacky partially-hydrolyzed ethylene-vinyl acetate (HEVA) copolymers. The copolymers are comminuted by dispersion in water with an alkali metal soap of a higher carboxylic acid. Chemical conversion of the soap after dispersion to the alkaline earth metal soap or to the higher carboxylic acid permits recovery of the tacky copolymers as dry powders. The compaction resistance of the higher carboxylic acid-coated particles is improved by chemically converting deposited acid to the alkaline earth metal soap or by adding supplemental preformed alkaline earth metal soap.
Inventors
- 👤 Dorothee M. McClain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:44
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/124; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/08
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
83 words
A process for improving the parting characteristics of particulate ethylene-vinyl acetate polymers comprising from about 25% to about 85% vinyl acetate units and corresponding hydrolyzed ethylene-vinyl acetate polymers which comprises agitating in molten state said polymer in an aqueous dispersion system comprising an alkali metal soap and cooling the resulting dispersion to obtain said polymer as finely divided particles; and converting said soap in situ to the carboxylic acid corresponding thereto or to the corresponding alkaline earth metal soap to coat said particles.
Claim 2
Dependent Claim
83 words
A process for improving the parting characteristics of particulate ethylene-vinyl acetate polymers comprising from about 25% to about 85% vinyl acetate units and corresponding hydrolyzed ethylene-vinyl acetate polymers which comprises agitating in molten state said polymer in an aqueous dispersion system comprising an alkali metal soap and cooling the resulting dispersion to obtain said polymer as finely divided particles; and converting said soap in situ to the carboxylic acid corresponding thereto or to the corresponding alkaline earth metal soap to coat said particles.
Claim 3
Dependent Claim
29 words
A process according to claim 1 wherein said dispersion system comprises an alkali metal soap of a saturated fatty acid of from about 8 to about 22 carbon atoms.
Claim 4
Dependent Claim
21 words
A process according to claim 1 wherein said dispersion system further comprises a water-soluble substantially neutral salt inert to said soap.
Claim 5
Dependent Claim
14 words
A process according to claim 1 wherein said soap comprises an alkali metal stearate.
Claim 6
Dependent Claim
12 words
A process according to claim 2 wherein said soap comprises sodium stearate.
Claim 7
Dependent Claim
24 words
A process according to claim 1 wherein said converting is effected by addition of a source of alkaline earth metal ions to said dispersion.
Claim 8
Dependent Claim
15 words
A process according to claim 6 wherein said source is calcium oxide or calcium hydroxide.
Claim 9
Dependent Claim
15 words
A process according to claim 6 wherein the dispersion is acidified prior to said addition.
Claim 10
Dependent Claim
15 words
A process according to claim 8 wherein said source is calcium oxide or calcium hydroxide.
Claim 11
Dependent Claim
23 words
A process according to claim 1 including the further step of adding to the resulting dispersion a supplemental parting agent for said polymer.
Claim 12
Dependent Claim
24 words
A process according to claim 1 wherein said converting is effecting by addition of acid to convert said soap to the corresponding carboxylic acid.
Claim 13
Dependent Claim
13 words
A process according to claim 11 wherein said carboxylic acid is stearic acid.
Claim 14
Dependent Claim
22 words
A process according to claim 1 including the further step of recovering the resulting polymer which after drying is a free-flowing powder.
Claim 15
Dependent Claim
97 words
A process for improving the parting characteristics of particulate saponified ethylene-vinyl acetate polymers which comprises agitating in molten state ethylene-vinyl acetate polymers comprising from about 25% to about 85% vinyl acetate units in an aqueous dispersion system comprising an alkali metal soap together with an alkali metal hydroxide in an amount sufficient to saponify said polymer to a predetermined degree and cooling the resulting dispersion to obtain said polymer as finely divided particles; and converting said soap in situ to the carboxylic acid corresponding thereto or to the corresponding alkaline earth metal soap to coat said particles.
Claim 16
Dependent Claim
97 words
A process for improving the parting characteristics of particulate saponified ethylene-vinyl acetate polymers which comprises agitating in molten state ethylene-vinyl acetate polymers comprising from about 25% to about 85% vinyl acetate units in an aqueous dispersion system comprising an alkali metal soap together with an alkali metal hydroxide in an amount sufficient to saponify said polymer to a predetermined degree and cooling the resulting dispersion to obtain said polymer as finely divided particles; and converting said soap in situ to the carboxylic acid corresponding thereto or to the corresponding alkaline earth metal soap to coat said particles.
Claim 17
Dependent Claim
14 words
A process according to claim 14 wherein said alkali metal hydroxide is sodium hydroxide.
Claim 18
Dependent Claim
12 words
A process according to claim 14 wherein said soap comprises sodium stearate.
Claim 19
Dependent Claim
24 words
A process according to claim 14 wherein said converting is effected by addition of a source of alkaline earth metal ions to said dispersion.
Claim 20
Dependent Claim
15 words
A process according to claim 17 wherein said source is calcium oxide or calcium hydroxide.
Claim 21
Dependent Claim
15 words
A process according to claim 17 wherein the dispersion is acidified prior to said addition.
Claim 22
Dependent Claim
25 words
A process according to claim 14 wherein said converting is effected by the addition of acid to convert said soap to the corresponding carboxylic acid.
Claim 23
Dependent Claim
22 words
A process according to claim 14 including the further step of recovering the resulting powder which after drying is a free-flowing powder.
Claim 24
Dependent Claim
76 words
Free-flowing, finely-divided ethylene-vinyl acetate polymers having an average particle diameter ranging from about 20 microns up to about 500 microns with the majority of particles being in the range of about 50 to about 100 microns comprising from about 25% to about 85% vinyl acetate the individual particles of which are surface coated with a higher hydrocarbon carboxylic acid or an alkaline earth metal salt of said acid in accordance with the process of claim 1.
Claim 25
Dependent Claim
13 words
A particulate polymer according to claim 22 wherein said acid is stearic acid.
Claim 26
Dependent Claim
16 words
A particulate polymer according to claim 22 wherein said alkaline earth metal is a calcium salt.
Claim 27
Dependent Claim
13 words
A particulate polymer according to claim 22 wherein said salt is calcium stearate.
Claim 28
Dependent Claim
29 words
A particulate polymer according to claim 22 wherein the polymer is an ethylene-vinyl acetate polymer comprising at least about 50% vinyl acetate units, and the acid is stearic acid.
Claim 29
Dependent Claim
13 words
A particulate polymer according to claim 26 wherein the salt is calcium stearate.
Claim 30
Dependent Claim
93 words
Free-flowing, finely-divided hydrolyzed ethylene-vinyl acetate polymers obtained from ethylene-vinyl acetate polymers containing from about 25% to about 85% vinyl acetate units, said hydrolyzed ethylene-vinyl acetate polymers having an average particle diameter exclusive of surface coating ranging from about 20 microns up to about 500 microns with the majority of particles being in the range of about 50 to about 100 microns and the individual particles of which are surface coated with a higher hydrocarbon carboxylic acid or an alkaline earth metal salt of said acid in accordance with the process of claim 14.
Claim 31
Dependent Claim
13 words
A particulate polymer according to claim 28 wherein said acid is stearic acid.
Claim 32
Dependent Claim
16 words
A particulate polymer according to claim 29 wherein said alkaline earth metal is a calcium salt.
Claim 33
Dependent Claim
13 words
A particulate polymer according to claim 29 wherein said salt is calcium stearate.
References Cited (Backward Citations)
US3090763A
Cited
US3517083A
Cited
US3422049A
Cited
US3347811A
Cited
US3432483A
Cited
US3468827A
Cited
US3474058A
Cited
US3503917A
Cited
US3968091A
Cited
US3891587A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |