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US 9,006,366 B2Granted
Processes using supercritical medium to produce polymers
AssigneeThe Procter & Gamble Company
InventorsThomas Tombuelt-Meyer, Axel Meyer, Torsten Lindner
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Abstract
Processes for making water-absorbent cross-linked polymers, such as polyacrylic acids/polyacrylates, using supercritical medium; and water-absorbent polymers, e.g. particles thereof, obtained by such processes, where such particles may be porous.
Claims19
A process for making water-absorbing cross-linked polymers comprising the steps of:
- a) obtaining polymerizable monomers;
- b) obtaining a supercritical reaction medium;
- c) obtaining a polymerization initiator system;
- d) obtaining a cross-linking system;
- e) combining the polymerizable monomers of step a) and the supercritical reaction medium of step b), the cross-linking compound of step d), and (simultaneously or subsequently) the polymerization initiator system of step c), to form a mixture;
- and
- f) polymerizing the polymerizable monomers to form polymers and cross-linking the polymers;
- to form water-absorbing cross-linked polymers;
- wherein step f), or steps e) and f), are done in a first reactor or reactor section with a first pressure;
- g) transferring the water-absorbing cross-linked polymers and supercritical medium of step f) to a second reactor or second reactor section that has a second, reduced pressure to obtain water-absorbing cross-linked polymers, and a gaseous phase of the supercritical medium, or part thereof;
- and
- h) separating the gaseous phase from the water-absorbing cross-linked polymers;
- wherein the water-absorbing cross-linked polymers obtained in step f) are in articulate form;
- and wherein the transfer in step g) to the second reactor or reactor section is done via one or more spray heads or nozzles.
11 more elements
A process for making water-absorbing cross-linked polymers comprising the steps of:
- a) obtaining polymerizable monomers;
- b) obtaining a supercritical reaction medium;
- c) obtaining a polymerization initiator system;
- d) obtaining a cross-linking system;
- e) combining the polymerizable monomers of step a) and the supercritical reaction medium of step b), the cross-linking compound of step d), and (simultaneously or subsequently) the polymerization initiator system of step c), and
- f) polymerizing the polymerizable monomers to form polymers and cross-linking the polymers wherein the process further comprises the steps of:
- to form water-absorbing cross-linked polymers;
- g) obtaining a neutralizing system;
- and
- h) combining the neutralizing system with the other components in step e), to form a mixture.
7 more elements
A process for making water-absorbing cross-linked polymers comprising the steps of:
- a) obtaining polymerizable monomers;
- b) obtaining a supercritical reaction medium;
- c) obtaining a polymerization initiator system;
- d) obtaining a cross-linking system;
- e) combining the polymerizable monomers of step a) and the supercritical reaction medium of step b), the cross-linking compound of step d), and (simultaneously or subsequently) the polymerization initiator system of step c), to form a mixture;
- f) polymerizing the polymerizable monomers to form polymers and cross-linking the polymers;
- to form water-absorbing cross-linked polymers;
- wherein step e) is done in a first reactor or reactor section with a first pressure wherein the process further comprises the steps of:
- g) transferring the mixture of step e) to a second reactor or second reactor section that has a second, reduced pressure, and performing step f) to obtain water-absorbing cross-linked polymers, and gaseous phase of the supercritical medium, or part thereof;
- and
- h) separating the gaseous phase from the water-absorbing cross-linked polymers.
8 more elements
Dependencies are inferred from the claim text.