Patent US3852257A successfully refreshed from Google Patents.
US3852257A
Expired / Lapsed
US
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Suspension polymerization in the presence of xanthan gum
Assignee: Kelco Co
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Filing: 1973-02-05
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Granted: 1974-12-03
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Expires: 1993-02-05
Abstract
Abstract In one aspect of this invention liquid monomers are polymerized to solid particulate polymer using the well-known suspension polymerization procedures and using as the suspension agent in the polymerization a combination of xanthan gum and polyvinyl alcohol. In the suspension polymerization of acrylic monomer, such as methyl methacrylate, to obtain solid particulate polymer the use of xanthan gum suspension agent affords an improved product size distribution. In the suspension polymerization of styrene monomers, such as styrene, to obtain solid polymer, the use of xanthan gum suspension agent in an amount of more than 0.75 weight percent, based on monomer charged, permits the production of particulate polymer.
Inventors
- 👤 D Pettitt
- 👤 Winkle T Van
- 👤 H Hartnek
- 👤 R Empey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 01:52
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/12; C08F2/16; C08F2/18; C08F2/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
73 words
IN THE PROCESS FOR THEAQUEOUS SUSPENSION POLYMERIZATION OF A LIQUID MONOMER TO A PARTICULATE POLYMER, WHERE THE MONOMER IS ACRYLIC ACID OR ITS POLYMERIZABLE DERIVATIVES, METHACRYLIC ACID OR ITS POLYMERIZABLE DERIVATIVES, ESTERS OR ETHERS OF VINCYL ALCOHOL, VINYLIDENE CHLORIDE, STYRENE OR METHYLSTYRENE, THE METHOD FOR OBTAINING PARTICULATE POLYMER OF ESSENTIALLY UNIFORM PARTICLE SIZE THAT COMPRISES CONDUCTING THE POLYMERIZATION IN THE PRESENCE OF FROM ABOUT 0.1 TO 4.0 PERCENT BY WEIGHT OF XANTHAN GUM.
Claim 2
Dependent Claim
73 words
IN THE PROCESS FOR THEAQUEOUS SUSPENSION POLYMERIZATION OF A LIQUID MONOMER TO A PARTICULATE POLYMER, WHERE THE MONOMER IS ACRYLIC ACID OR ITS POLYMERIZABLE DERIVATIVES, METHACRYLIC ACID OR ITS POLYMERIZABLE DERIVATIVES, ESTERS OR ETHERS OF VINCYL ALCOHOL, VINYLIDENE CHLORIDE, STYRENE OR METHYLSTYRENE, THE METHOD FOR OBTAINING PARTICULATE POLYMER OF ESSENTIALLY UNIFORM PARTICLE SIZE THAT COMPRISES CONDUCTING THE POLYMERIZATION IN THE PRESENCE OF FROM ABOUT 0.1 TO 4.0 PERCENT BY WEIGHT OF XANTHAN GUM.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the monomer is acrylic acid or a polymerizable derivative thereof and the xanthan gum is present at from about 0.1 to 1.0 percent by weight of monomer.
Claim 4
Dependent Claim
27 words
The process of claim 1 wherein the monomer is styrene or methylstyrene and the xanthan gum is present at from about 1-4 percent by weight of monomer.
Claim 5
Dependent Claim
36 words
The process of claim 1 wherein the polymerization is carried out in the presence of xanthan gum and polyvinyl alcohol, and the weight ratio of xanthan gum to polyvinyl alcohol is from about 10:1 to 1:10.
Claim 6
Dependent Claim
21 words
The process of claim 4 wherein the weight ratio of xanthan gum to polyvinyl alcohol is from about 3:1 to 1:3.
Claim 7
Dependent Claim
32 words
The process of claim 5 wherein the monomer is acrylic acid or a polymerizable derivative thereof and the weight of xanthan gum is in excess of 0.75 percent by weight of monomer.
Claim 8
Dependent Claim
27 words
The process of claim 5 wherein the monomer is styrene and the weight of xanthan gum is from about 0.1 to 4.0 percent by weight of monomer.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |