US4293679A
Expired / Lapsed
US
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Composition and method of controlling solid polyurethane particle size with water reactant
Assignee: WR Grace and Co
•
Filing: 1980-05-27
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Granted: 1981-10-06
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Expires: 2000-05-27
Abstract
Abstract This invention relates to control of particle size of solid, discrete, hydrophilic, crosslinked polyurethane particles formed from a composition which comprises (a) a water reactant; (b) a prepolymer comprising at least one isocyanate-capped polyol having a reaction functionality of at least two, the total of said polyol present having an ethylene oxide content of at least 40 weight percent before capping; (c) a water-soluble solvent for (b) and (d) when the reaction functionality of (b) is two, a crosslinking agent containing at least three functional groups, the volume ratio of (a):(b) being at least 2:1.
Inventors
- 👤 Joseph A. Cogliano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:53
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4833; C08G18/08; C08G18/10; C08G18/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
89 words
A process for forming solid, discrete, hydrophilic, crosslinked, polyurethane particles of reduced size which comprises adding (a) a hydrophilic prepolymer comprising an isocyanate-capped polyol or mixture of isocyanate-capped polyols wherein said isocyanate-capped polyol or mixture of polyols has a reaction functionality greater than 2, the total of said polyol present having an ethylene oxide content of at least 40 weight percent before capping; (b) said prepolymer (a) being dissolved in a water soluble solvent, to (c) an agitated water reactant, the volume ratio of (c):(a) being at least 2:1.
Claim 2
Dependent Claim
89 words
A process for forming solid, discrete, hydrophilic, crosslinked, polyurethane particles of reduced size which comprises adding (a) a hydrophilic prepolymer comprising an isocyanate-capped polyol or mixture of isocyanate-capped polyols wherein said isocyanate-capped polyol or mixture of polyols has a reaction functionality greater than 2, the total of said polyol present having an ethylene oxide content of at least 40 weight percent before capping; (b) said prepolymer (a) being dissolved in a water soluble solvent, to (c) an agitated water reactant, the volume ratio of (c):(a) being at least 2:1.
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein the water-soluble solvent (b) is present in an amount ranging from 20 to 99% by weight of the prepolymer solution of (b) and (a).
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein the water-soluble solvent is a member of the group consisting of acetone, methyl ethyl ketone, dimethylsulfoxide, dimethylformamide, n-methylpyrrolidone, acetonitrile, methyl acetate and mixtures thereof.
Claim 5
Dependent Claim
21 words
The process according to claim 1 containing an excess of polyisocyanate up to about four isocyanate groups/OH group in the polyol.
Claim 6
Dependent Claim
33 words
The process according to claim 1 wherein said prepolymer is the reaction product of a polyether polyol with sufficient polyisocyanate to provide at least two free NCO groups per molecule of the prepolymer.
Claim 7
Dependent Claim
21 words
The process according to claim 1 in which the isocyanate-capped polyol is prepared by reacting toluene diisocyanate and a polyethylene glycol.
Claim 8
Dependent Claim
28 words
The process according to claim 1 in which the isocyanate-capped polyol is prepared by reacting toluene diisocyanate and a polyethylene glycol having a molecular weight of about 1,000.
Claim 9
Dependent Claim
41 words
The process according to claim 1 in which the prepolymer is prepared by reacting toluene diisocyanate and a member selected from the group consisting of a polyoxyethylene-polyoxybutylene polyol, ethylene glycol, diethylene glycol, a polyoxyethylene polyol, a polyoxyethylene-polyoxypropylene polyol and mixtures thereof.
Claim 10
Dependent Claim
71 words
The process according to claim 1 in which the prepolymer is prepared by reacting toluene diisocyanate with an admixture of a polyethylene glycol having a molecular weight in the range 200-2,000 and trimethylolpropane, the trimethylolpropane and the polyethylene glycol being provided in a mole ratio of about 1:1-4 and the toluene diisocyanate being provided in an amount up to four isocyanate groups/OH group provided by the polyethylene glycol and the trimethylolpropane.
Claim 11
Dependent Claim
50 words
The process according to claim 1 wherein the prepolymer is an isocyanate-capped polyoxyethylene polyol having a number average molecular weight in the range 200 to 20,000 before capping, said number average molecular weight being calculated by measurement of the hydroxyl content of the polyol from the formula: M.sub.n =(56.1×1000×functionality)/(OH No.).
Claim 12
Dependent Claim
19 words
The process according to claim 10 wherein the number average molecular weight is in the range 600 to 6,000.
Claim 13
Dependent Claim
22 words
The process of claim 1 wherein the polyurethane particles formed have an average diameter in the range 30 A to 0.25 cm.
References Cited (Backward Citations)
US2901467A
Cited
US3402149A
Cited
US3655627A
Cited
US3850880A
Cited
US3822238A
Cited
US3939123A
Cited
US4108954A
Cited
US4145515A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-05 | 1985-04-06 | 1985-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-05 | 1989-04-06 | 1989-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-05 | 1993-04-06 | 1993-10-06 | $7700.00 | Window Closed / Lapsed |