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US 7,604,756 B2Granted
Preparation of silver particles using thermoplastic polymers
AssigneeE. I. Du Pont de Nemours and Company
InventorSteven Dale Ittel
Life of this patent
Estimating the term…
Abstract
This invention relates to the synthesis and isolation of colloidal silver particles through the use of thermomorphic polymers and the resulting composition. It further relates to the use of the resulting composition in the preparation of inks for printing with silver-containing inks.
Claims18
A silver particle agglomerate prepared and isolated by a process comprising:
- a) providing, at a first temperature, a combined mixture comprising 1) an aqueous solution of a silver(I) salt and an amine and 2) a second aqueous solution comprising a reducing agent;
- said combined mixture further comprising a thermomorphic polymer having a transition temperature, said thermomorphic polymer being in a homogenous phase at said first temperature;
- and
- b) changing the temperature of the combined solution from the first temperature to a second temperature at which the thermomorphic polymer is in a heterogeneous phase, such that the thermomorphic polymer and silver separate from the combined solution to form an agglomerate;
- and
- c) isolating the silver particle agglomerate from the reaction medium.
3 more elements
A silver ink composition comprising:
- silver particles prepared and isolated by a process comprising:
- a) providing, at a first temperature, a combined mixture comprising 1) an aqueous solution of a silver(I) salt and an amine and 2) a second aqueous solution comprising a reducing agent;
- said combined mixture further comprising a thermomorphic polymer having a transition temperature, said thermomorphic polymer being in a homogenous phase at said first temperature;
- and
- b) changing the temperature of the combined solution from the first temperature to a second temperature at which the thermomorphic polymer is in a heterogeneous phase, such that the thermomorphic polymer and silver separate from the combined solution to form an agglomerate;
- and
- c) isolating the agglomerate from the reaction medium, and an ink medium comprising:
- (a) 3 to 20 weight percent of at least one diol;
- (b) 0 to 5 weight percent of at least one glycol ether;
- (c) 0.5 to 5 weight percent of at least one component selected from surfactants, buffers, and biocides;
- (d) 0.01 to 2 weight percent of at least one viscoelastic polymer;
- and
- (e) the balance water.
10 more elements
Dependencies are inferred from the claim text.