Method of making controlled released devices
AssigneeBattelle Memorial Institute
InventorsDominic C. Cataldo, Peter Van Voris
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Abstract
The invention is a method of making a controlled release device that is free of defects. According to one aspect of the present invention, a method has the steps of first combining an active chemical with a dried carrier into a bound friable mixture followed by combining the bound friable mixture with a polymer preform prior to forming a device. According to another aspect of the present invention, a method has the steps of heating and mixing a casting urethane with an active chemical into a first solution, heating and mixing a trialkanolamine with a soft segment cross-linker into a second solution, and mixing the two solutions. A further aspect of the present invention is a composition of a casting urethane.
Claims47
A method of making a controlled release device, said controlled release device having a polymer, a carrier, and an active chemical, the method vaporizing said active chemical, wherein the improvement comprises the steps of:
- (a) insuring that the active chemical is blendable with the carrier;
- (b) removing moisture from the carrier;
- (c) blending said active chemical with the dried carrier into a bound friable mixture;
- (d) adding the bound friable mixture into an amount of a polymer preform and forming a formable mixture;
- (e) forming the formable mixture into the controlled release device with substantially reduced vaporization.
A method of making a controlled release device having a polymer and an active chemical, the method comprising the steps of:
- (a) selecting an amine curable elastomer pre-polymer;
- (b) heating the pre-polymer making a first solution;
- (c) heating and mixing an amine with a soft segment cross-linker making a second solution;
- (d) mixing the active chemical into either the first solution, second solution or both;
- (d) pouring said second solution together with said first solution into a combined solution and continuing heating while mixing said combined solution into a castable mixture;
- and
- (e) casting said castable mixture.
A controlled release composition comprising a urethane containing an active chemical, wherein the improvement comprises:
- (a) said urethane is a casting urethane having ur linkages;
- (b) a soft segment cross-linker;
- and
- (c) a trialkanolamine cross-linker/catalyst in an amount from about 1.0 wt % to about 5 wt %.
A method of making a controlled release device, said controlled release device having a polymer, a dry solid carrier, and a liquid active chemical, the method comprising the steps of:
- (a) blending said liquid active chemical with the dry solid carrier, forming an active chemical containing carrier;
- (b) mixing the active chemical containing carrier with a polymer making a formable mixture;
- (c) forming the formable mixture into the controlled release device with substantially reduced release rate.
Dependencies are inferred from the claim text.