US3900378A
Expired / Lapsed
US
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Hydrogels from radiation crosslinked blends of hydrophilic polymers and fillers
Assignee: Union Carbide Corp
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Filing: 1972-11-06
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Granted: 1975-08-19
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Expires: 1992-11-06
Abstract
Abstract Particulate, Free-Flowing, Insoluble Swellable Polymers are provided which are comprised of a mixture of an insoluble, swellable hydrogel and inert filler. The mixtures are freeflowing powders or granules which can absorb many times their weight of water and hence are useful as a soil amendment.
Inventors
- 👤 Steven N Yen
- 👤 Frederick D Osterholtz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:22
CPC Classifications
C; C08; C08L; C08L101/00; A; A01; A01G; A01G24/00; A01G24/20; A01G24/22; A01G24/23; A01G24/30; A01G24/35; A01G24/40; A01G24/42; A01N; A01N25/00; A01N25/08; A01N25/10; A61; A61L; A61L15/00; A61L15/16; A61L15/18; A61L15/20; A61L15/40; A61L15/42; A61L15/60; C05; C05D; C05D9/00; C05G; C05G5/00; C05G5/30; C05G5/37; C05G5/40; C08J; C08J3/00; C08J3/12; C08J3/124; C08J3/20; C08J3/205; C08J3/28; C09; C09K; C09K17/00; C09K17/14; C09K17/16; C09K17/18; C09K17/20; C09K17/22; C09K17/40; C08J2300/00; C08J2300/10; C08J2300/14; Y; Y10; Y10S; Y10S47/00; Y10S47/10; Y10S604/00; Y10S604/904; Y10S71/00; Y10S71/903
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
155 words
A PROCESS FOR THE PREPARATION OF A FREE-FLOWING, WATER SWELLABLE HYDROPHILIC POLYMER IN PARTICULATE FORM, SAID PROCESS COMPRISING THE STEPS OF: A. BLENDING A MIXTURE OF AT LEAST ONE WATER SOLUBLE PULVERUBENT HYDROPHILIC POLYMER AND AT LEAST ONE PULVERULENT INERT FILLER IN A RATIO OF POLYMER TO FILLER OF FROM ABOUT 1.9 TO ABOUT 9:1, A SUBSTANTIAL PORTION OF SAID FILLER HAVING A PARTICLE SIZE LESS THAN THAT OF SAID POLYMER AND PRESENT IN AN AMOUNT SUFFICIENT TO COVER A SUBSTANTIAL PORTION OF THE SURFACE AREA OF SAID PULVERLUENT POLYMER, B. THEREAFTER WHILE SAID BLENDING IS CONTINUED, CONTACTING SAID MIXTURE UNDER THROUGH AGITATION WITH A FINELY DIVIDED SPRAY OF WATER AT A RATE AND IN AN AMOUNT NOT TO EXCEED THAT AT WHICH THE MIXTURE IS MAINTAINED IN A FREEFLOWING PARTICULATE FORM, AND C. THEREAFTER EXPOSING SAID MIXTURE IN SAID FREE-FLOWING PARTICULATE FORM TO IONIZING RADIATION FOR A PERIOD OF TIME TO CROSSLINK SAID POLYMER.
Claim 2
Dependent Claim
155 words
A PROCESS FOR THE PREPARATION OF A FREE-FLOWING, WATER SWELLABLE HYDROPHILIC POLYMER IN PARTICULATE FORM, SAID PROCESS COMPRISING THE STEPS OF: A. BLENDING A MIXTURE OF AT LEAST ONE WATER SOLUBLE PULVERUBENT HYDROPHILIC POLYMER AND AT LEAST ONE PULVERULENT INERT FILLER IN A RATIO OF POLYMER TO FILLER OF FROM ABOUT 1.9 TO ABOUT 9:1, A SUBSTANTIAL PORTION OF SAID FILLER HAVING A PARTICLE SIZE LESS THAN THAT OF SAID POLYMER AND PRESENT IN AN AMOUNT SUFFICIENT TO COVER A SUBSTANTIAL PORTION OF THE SURFACE AREA OF SAID PULVERLUENT POLYMER, B. THEREAFTER WHILE SAID BLENDING IS CONTINUED, CONTACTING SAID MIXTURE UNDER THROUGH AGITATION WITH A FINELY DIVIDED SPRAY OF WATER AT A RATE AND IN AN AMOUNT NOT TO EXCEED THAT AT WHICH THE MIXTURE IS MAINTAINED IN A FREEFLOWING PARTICULATE FORM, AND C. THEREAFTER EXPOSING SAID MIXTURE IN SAID FREE-FLOWING PARTICULATE FORM TO IONIZING RADIATION FOR A PERIOD OF TIME TO CROSSLINK SAID POLYMER.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said hydrophilic polymer and said inert filler are blended in step (a) in the dry state.
Claim 4
Dependent Claim
45 words
The process of claim 1 wherein said inert filler prior to contact with said hydrophilic polymer in step (a) is blended with a portion of said water in an amount not to exceed that at which the filler is maintained in a free-flowing particulate form.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein the mixture is dried after step (c) to remove at least some of said water.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the hydrophilic polymer is poly(alkylene oxide).
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein the hydrophilic polymer is poly(ethylene oxide).
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the hydrophilic polymer is a polyacrylamide.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein the hydrophilic polymer is a partially hydrolyzed polyacrylamide.
Claim 10
Dependent Claim
12 words
The process of claim 1 wherein the hydrophilic polymer is polyvinyl alcohol.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein the hydrophilic polymer is hydroxyethyl cellulose.
Claim 12
Dependent Claim
13 words
The process of claim 1 wherein the hydrophilic polymer is an ammonium polyacrylate.
Claim 13
Dependent Claim
13 words
The process of claim 1 wherein the hydrophilic polymer is polymerized hydroxyalkyl acrylate.
Claim 14
Dependent Claim
13 words
The process of claim 1 wherein the hydrophilic polymer is polymerized hydroxyalkyl methacrylate.
Claim 15
Dependent Claim
22 words
The process of claim 1 wherein the hydrophilic polymer is selected from the group consisting of polymerized hydroxyalkoxyalkyl acrylates and alkoxyalkyl acrylates.
Claim 16
Dependent Claim
22 words
The process of claim 1 wherein the hydrophilic polymer is selected from the group consisting of polymerized hydroxyalkoxyalkyl methacrylates and alkoxyalkyl methacrylates.
Claim 17
Dependent Claim
23 words
The process of claim 1 wherein the hydrophilic polymer is a polymerized alkylene oxide or poly(alkylene oxide) adduct of acrylate and methacrylate esters.
Claim 18
Dependent Claim
12 words
The process of claim 1 wherein the inert filler is pulverulent wood.
Claim 19
Dependent Claim
13 words
The process of claim 1 wherein the inert filler is pulverulent diatomaceous earth.
Claim 20
Dependent Claim
12 words
The process of claim 1 wherein the inert filler is cellulose floc.
Claim 21
Dependent Claim
13 words
The process of claim 1 wherein the inert filler is cotton linter floc.
Claim 22
Dependent Claim
12 words
The process of claim 1 wherein the inert filler is coal dust.
Claim 23
Dependent Claim
11 words
The process of claim 1 wherein the inert filler is clay.
Claim 24
Dependent Claim
12 words
The process of claim 1 wherein the inert filler is a fertilizer.
Claim 25
Dependent Claim
13 words
The process of claim 1 wherein the inert filler is a magnesium silicate.
Claim 26
Dependent Claim
26 words
The process of claim 1 wherein reagent grade or technical grade tricalcium phosphate is substituted for at least about 0.5 weight per cent of said filler.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |