Back to results
US 5,069,972 AGranted
Moldable microcapsule that contains a high percentage of solid core material, and method of manufacture thereof
OwnerRonald J. Versicinventor
Life of this patent
Estimating the term…
Abstract
Microcapsules having a high loading factor of core material are formed as separate, reservoir microcapsules by coating solid core particles first with a thin, conformal layer of parylene and then with a layer of thermoplastic material.
Claims19
A moldable microcapsule comprising:
- (a) a solid core;
- (b) a conformal, insulating inner layer of parylene encapsulating the core and being free of pinholes;
- and
- (c) an outer layer encapsulating the inner layer and the core, the outer layer comprising a moldable material that has a melting temperature less than that of the inner layer and is tied to the particle by the inner layer, the inner layer having a volume not substantially greater than 8% of the total volume of the microcapsule, and the outer layer having a volume not substantially greater than 24% of the total volume of the microcapsule, and the combined volume of both layers being not substantially greater than 25% of the total volume of the microcapsule.
1 more element
A pressure-molded product formed of microcapsules, each of which comprises:
- (a) a solid core particle;
- (b) an inner, conformal pinhole-free insulating layer of parylene;
- and
- (c) an outer layer of moldable binder material, the layer of parylene forming a primer coat to tie the layer of moldable binder material to the parylene-coated particle and having a melting temperature higher than the molding temperature at which the pressure-molded product is formed, the parylene inner layer of each microcapsule having a volume not substantially greater than 8% of the total volume of that microcapsule, and the outer layer of each capsule having a volume not substantially greater than 24% of the total volume of that microcapsule, at least 75% of the mass of the pressure-molded product consisting of the solid core particles of the microcapsules.
1 more element
A method of molding a shaped structure of moldable microcapsules, said structure having a high percentage of magnetic material, said method comprising the steps of:
- (a) pyrolyzing a quantity of parylene dimer to form monomeric free radicals thereof;
- (b) molecularly depositing the free radicals on the surface of each particle of a quantity of solid particles of magnetic material while tubling the particles in a low pressure chamber to form a protective polymer inner layer of the monomeric free radicals on all surfaces of each of the particles, separately;
- (c) forming an outer layer of moldable plastic binder material in engagement with the inner layer, said plastic binder material having a shaping temperature lower than the melting temperature of the parylene, the parylene inner layer of each microcapsule having a volume not substantially greater than 8% of the total volume of that microcapsule, and the outer layer of each capsule having a volume not substantially greater than 24% of the total volume of the microcapsule, the combined volume of the inner and outer layers of each microcapsule being not substantially greater than 25% of the total volume of that microcapsule;
- and
- (d) subjecting a mass of the binder-coated particles to heat above the melting temperature of the binder material and, simultaneously, to pressure sufficient to form the mass into a monolithic body capable of retaining its configuration after being cooled.
2 more elements
Dependencies are inferred from the claim text.