Abstract: Microsphere wet cake is mixed with a surface barrier coating effective to prevent agglomeration and surface bonding of the microspheres, and removing water by drying with continuous mixing at high shear. In a subsequent step, by the control of the application of heat and balancing temperature and low shear mixing, it is possible to also control expansion of the microspheres.The surface barrier coating in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, dry inorganic pigments or filler materials, and the like, and related organic materials.
Type:
Grant
Filed:
March 8, 1990
Date of Patent:
January 19, 1993
Assignee:
Pierce & Stevens Corporation
Inventors:
George E. Melber, Leon E. Wolinski, William A. Oswald
Abstract: A magneto optic recording medium comprising a substrate, an amorphous magnetizable rare earth-transition metal alloy layer, a transparent dielectric layer on at least one side of the magnetizable layer, and a reflective surface located to reflect light through the magnetizable alloy layer. The dielectric layer is comprised of silicon carbide of the formula SiC.sub.x, wherein x, the molar ratio of carbon to silicon, is greater than 1. The dielectric layer is preferably deposited by direct current magnetron sputtering at low argon partial pressure from an electrically conductive mixture of silicon carbide and carbon. The medium exhibits similar or improved characteristics over media constructed with present dielectrics, for example, silicon suboxide (SiO.sub.y, y<2).
Type:
Grant
Filed:
May 25, 1989
Date of Patent:
October 27, 1992
Assignee:
Minnesota Mining and Manufacturing Company
Abstract: The surface-modified polymethylsilsesquioxane spherical fine particles of this invention comprise polymethylsilsesquioxane spherical fine particles serving as nuclei, and at least one member of an alkyl group having two or more carbon atoms, an alkenyl group, a phenyl group, an epoxy group, an acryloxy group and an amino group is bonded to the surface of a particle. They are prepared by a process comprising the step of carrying out reaction in an aqueous suspension of polymethylsilsesquioxane fine particles in the presence of an alkali catalyst. The surface-modified spherical fine particles can have various organic groups on their surfaces, and are used in various fields such as rubbers, plastics, coating materials, inks, and cosmetics, depending on the types of the organic groups.
Abstract: The invention relates to a composite particle comprising 2 to 98% by weight of a base resin having softending point of -10.degree. to 120.degree. C. and a number average molecular weight of 600 or more and 98 to 2% by weight of an anisotropic crystalline polymer having a phase transition point of 60.degree. to 230.degree. C. and a number average molecular weight of 600 to 10,000 and capable for forming an anisotropic molten phase, the polymer having the specific structure in which a repeating unit of the formula:A--X--B (I)(wherein 100 to 50 mol % of A stands for defined mesogenic group, 0 to 50 mole % of A is p-phenylene, m-phenylene or trans-1,4-cyclohexylene, B is a defined spacer group, and X is ester bond, carbonate bond, amide bond, urethane bond or urea bond, and a repeating unit of the formula:R (II)in which R stands for bivalent to hexavalent hydrocarbon residue, are connected, in any successive orders and in a weight ratio of (I)/(II)=99.9/0.