Crosslinked organic porous particles
View Patent ↗Crosslinked organic porous particles are non-swellable in propyl acetate and have a crosslinked organic solid phase and discrete pores dispersed within the crosslinked organic solid phase, which discrete pores are isolated from each other. The discrete pores have an average size greater than or equal to 0.1 μm and the crosslinked organic porous particles have a mode particle size of at least 3 μm and up to and including 100 μm. The discrete pores can contain a marker material.
1. A crosslinked organic porous particle comprising a crosslinked organic polymer that provides a crosslinked organic solid phase including an external particle surface and first and second discrete pores that are isolated from each other and dispersed and enclosed entirely within the crosslinked organic solid phase, the first and second discrete pores having an average size greater than or equal to 0.1 μm, and the mode particle size of the crosslinked organic porous particles is at least 3 μm and up to and including 100 μm, and the crosslinked organic solid phase further comprises a low HLB emulsifier that is selected from the group consisting of sorbitan esters of fatty acids, polyethylene oxide esters of fatty acids, tetrafunctional block copolymer with terminal secondary hydroxyl groups, and polyglycerol polyricinoleate,
wherein the crosslinked organic porous particle further comprises a first marker material that is present within only the volume of the first discrete pores, and the volume of the second discrete pores is either empty of marker materials or is at least partially occupied by a second marker material, which first and second marker materials are detectably different, and
the crosslinked organic porous particles has a porosity of at least 1% and up to and including 80% of total crosslinked organic porous particle volume.
2. The crosslinked organic porous particle of claim 1 wherein the crosslinked organic polymer is a chemically crosslinked thermoplastic resin.
3. The crosslinked organic porous particle of claim 1 that is insoluble in propyl acetate for 24 hours at room temperature.
4. The crosslinked organic porous particle of claim 1 further wherein the first marker material is a radiation absorber.
5. The crosslinked organic porous particle of claim 1 that recovers at least 80% of its volume after being subjected to 200° C. and 1500 pounds (105.5 kg f /cm 2 ) pressure for 5 minutes.
6. The crosslinked organic porous particle of claim 1 wherein the first and second marker materials are selected from the group consisting of different colored pigments or dyes, different fluorescing materials, different radioisotopes, particles of different metal or metal-containing compounds having different magnetic moments, different luminescing compounds, and different bioactive materials.
7. The crosslinked organic porous particle of claim 1 , further comprising additional discrete pores besides the first and second discrete pores that optionally have a marker material within the volume of the additional discrete pores, and which marker material is different from the first and second marker materials.
8. The crosslinked organic porous particle of claim 1 wherein at least some of the first and second discrete pores comprise a pore stabilizing hydrocolloid that is selected from the group consisting of carboxymethyl cellulose (CMC), a gelatin or gelatin derivative, a protein or protein derivative, a hydrophilic synthetic polymer, a water-soluble microgel, a polystyrene sulfonate, poly(2-acrylamido-2-methylpropanesulfonate), and a polyphosphate.
9. The crosslinked organic porous particle of claim 1 wherein the first and second discrete pores have an average size of at least 0.1 μm and up to and including 4 μm.
10. The crosslinked organic porous particle of claim 1 wherein the first and second discrete pores have different average sizes.
11. The crosslinked organic porous particle of claim 1 that has a mode particle size of at least 5 μm and up to and including 70 μm.
12. The crosslinked organic porous particle of claim 1 having an aspect ratio of at least 0.9.
13. The crosslinked organic porous particle of claim 1 having an aspect ratio of at least 0.4 and up to but less than 0.95.
14. The crosslinked organic porous particle of claim 1 wherein its external surface comprises colloidal particles.
15. The crosslinked organic porous particles of claim 1 wherein its external surface comprises colloidal silica particles.
16. A multiplicity of the crosslinked organic porous particles of claim 1 that is in either powder form, or an aqueous suspension.