Methods for devolatilizing resin solutions and resins produced thereby
First Claim
1. In a method of continuously devolatilizing a liquefied material, utilizing an extruder comprising a barrel defining an interior space in which is disposed a plurality of intermeshing conveying screws for advancing a flow of the liquefied material within the interior space from an extruder inlet to an extruder outlet, the method comprising the steps of:
- A. providing, as the liquefied material to be devolatilized, a mixture of resin selected from the group consisting of acrylic resins and urethane (meth)acrylate resins and a solvent for the resin;
B. continuously advancing the flow of material from the extruder inlet to the extruder outlet by the conveying screws;
C. introducing heat from an external source into the flow of liquefied material during step B for promoting the separation of gaseous volatiles from the liquefied material; and
D. venting separated gaseous volatiles from the interior space at a plurality of venting locations along the direction of travel by communicating the interior space with respective vapor escape ports, each port is being sufficiently large to prevent the linear vapor velocity of vapor escaping therethrough from exceeding about 10-15 f/sec.
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Accused Products
Abstract
A method of continuously devolatilizing a liquefied material utilizing an extruder having a barrel in which is disposed a plurality of continuously driven intermeshing conveying screws that continuously advance a flow of the liquefied material from an extruder inlet to an extruder outlet. The material contains 10-60 percent gaseous volatiles. Heat is introduced from an external source into the flow of liquefied material to progressively increase the temperature of the liquefied material being advanced, for promoting the separation of volatiles therefrom. Separated gaseous volatiles are vented through vapor escape ports formed in the extruder barrel, with the linear vapor velocity of the escaping volatiles not exceeding about 10-15 f/sec to avoid the venting of appreciable amounts of liquefied material along with the gaseous volatiles.
46 Citations
26 Claims
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1. In a method of continuously devolatilizing a liquefied material, utilizing an extruder comprising a barrel defining an interior space in which is disposed a plurality of intermeshing conveying screws for advancing a flow of the liquefied material within the interior space from an extruder inlet to an extruder outlet, the method comprising the steps of:
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A. providing, as the liquefied material to be devolatilized, a mixture of resin selected from the group consisting of acrylic resins and urethane (meth)acrylate resins and a solvent for the resin; B. continuously advancing the flow of material from the extruder inlet to the extruder outlet by the conveying screws; C. introducing heat from an external source into the flow of liquefied material during step B for promoting the separation of gaseous volatiles from the liquefied material; and D. venting separated gaseous volatiles from the interior space at a plurality of venting locations along the direction of travel by communicating the interior space with respective vapor escape ports, each port is being sufficiently large to prevent the linear vapor velocity of vapor escaping therethrough from exceeding about 10-15 f/sec. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. In a method of continuously devolatilizing a liquefied material utilizing an extruder comprising a barrel defining an interior space in which is disposed more than six intermeshing conveying screws for advancing a flow of the liquefied material within the interior space from an extruder inlet to an extruder outlet, the interior space divided into a plurality of chambers along the direction of flow advancement, the method comprising the steps of:
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A. heating a mixture of an acrylic resin and a solvent for the resin to about its boiling temperature at 1 atmosphere so as to provide the liquefied material to be devolatilized, the material containing 10-60 percent volatiles; B. continuously advancing the flow of material from the extruder inlet to the extruder outlet by the conveying screws; C. introducing heat from an external source into the flow of liquefied material during step B for promoting the separation of gaseous volatiles from the liquefied material; D. venting separated gaseous volatiles from the interior space at a plurality of locations along the direction of travel by communicating the interior space with respective vapor escape ports, each vapor escape port being sufficiently large to prevent the linear vapor velocity of vapor escaping therethrough from exceeding about 10-15 f/sec; and E. applying a vacuum to at least a plurality of the vapor escape ports during step D, wherein the strength of the vacuum varies from one chamber to the next and becomes greater toward the extruder outlet. - View Dependent Claims (22, 23)
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24. In a method of continuously devolatilizing a liquefied material utilizing an extruder comprising a barrel defining an interior space in which is disposed more than six intermeshing conveying screws for advancing a flow of the liquefied material within the interior space from an extruder inlet to an extruder outlet, the method comprising the steps of:
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A. providing, as the liquefied material to be devolatilized, a mixture of resin consisting of urethane acrylate (methacrylate) resins and a solvent for the resin, the material containing 10-60 percent volatiles; B. continuously advancing the flow of material from the extruder inlet to the extruder outlet by the conveying screws; C. introducing heat from an external source into the flow of liquefied material during step B for promoting the separation of gaseous volatiles from the liquefied material; D. venting separated gaseous volatiles from the interior space at a plurality of locations along the direction of travel by communicating the interior space with respective vapor escape ports, each vapor escape port being sufficiently large to prevent the linear vapor velocity of vapor escaping therethrough from exceeding about 10-15 f/sec.; and E. applying a vacuum to at least a plurality of the vapor escape ports during step D, wherein the strength of the vacuum is substantially the same at each of the vapor escape ports. - View Dependent Claims (25, 26)
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Specification