Particles with designed different sized discrete pores
AssigneeEastman Kodak Company
InventorsDavid Charles Boris, Teresa Joy Hosmer, Mridula Nair
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Abstract
Polymeric porous particles have a continuous solid phase and at least two sets of discrete pores that are isolated from each other within the continuous phase and that have different average sizes. One set of discrete pores has a larger average size than another set of discrete pores by at least 50%. At least one set of discrete pores is free of detectably different marker materials. There porous particles can be prepared using evaporative limited coalescence techniques with especially chosen discrete pore stabilizing hydrocolloids to protect the pores during formation and to provide the different average sizes.
Claims12
A porous particle comprising one or more organic polymers that provide a polymer that provides a continuous solid phase including an external particle surface, and at least first and second discrete closed pores that are isolated from each other and dispersed within the continuous phase, the first and second discrete closed pores having first and second average sizes,
- wherein:
- the second average size is greater than the first average size by at least 50%,
- the first or second discrete closed pores are free of detectably different marker materials selected from the group consisting of colorants (dyes and pigments), metallic pigments, fluorescing materials, radioisotopes, metal oxides, metal hydroxides, metal sulfides, metal oxyhydroxides, and luminescing compounds,
- the porous particle has a mode particle size of at least 2 μm and up to and including 50 μm, and
- the first and second discrete closed pores comprise first and second discrete pore stabilizing hydrocolloids, respectively, which provide different osmotic pressures of at least 0.4 psi.
Dependencies are inferred from the claim text.