Ming-Ta Hsu

6339034, Jan 15, 2002

Jan 24, 2000

09/490677

Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

HC Chem Research Service Corp. - San Jose CA

C04B 3514

501 80, 501 85, 501133, 423338

Ultra-high temperature, light-weight, ceramic insulation such as ceramic tile is obtained by pyrolyzing a siloxane gel derived from the reaction of at least one organo dialkoxy silane and at least one tetralkoxy silane in an acid or base liquid medium. The reaction mixture of the tetra- and dialkoxy silanes may contain also an effective amount of a mono- or trialkoxy silane to obtain the siloxane gel. The siloxane gel is dried at ambient pressures to form a siloxane ceramic precursor without significant shrinkage. The siloxane ceramic precursor is subsequently pyrolyzed, in an inert atmosphere, to form the black ceramic insulation comprising atoms of silicon, carbon and oxygen. The ceramic insulation, can be characterized as a porous, uniform ceramic tile resistant to oxidation at temperatures ranging as high as 1700Â C. and is particularly useful as lightweight tiles for spacecraft and other high-temperature insulation applications.

6472067, Oct 29, 2002

Sep 27, 2001

09/963384

Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

HC Chem Research and Service Corp. - San Jose CA

B32B 900

428367, 428408, 428391, 428396, 428447, 428688, 1563071, 1563073, 156311, 156312

Non-flammable, fibrous-siloxane cured composites derived from the polymerization of dialkoxysilanes, trialkoxysilanes and tetraalkoxysilanes, in an aqueous medium, to obtain viscous polysiloxane resins. These siloxane resins are used to impregnate or coat various fibrous materials such as carbon fibers or glass cloth which are subsequently subjected to heat and pressure to form cured, non-flammable siloxane-impregnated composites e. g. panels having a density of about 1 to 3 g/cc. and a limited oxygen index above 30. These non-flammable, fibrous-siloxane composites are particularly useful in the manufacture of fire-proof materials for various transportation vehicles and for building materials e. g. panels as a fire barrier.

6620749, Sep 16, 2003

Oct 9, 2001

09/972817

Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

HC Chem Research and Service Corp. - San Jose CA

C04B 3514

501 80, 501 85, 501133, 423338, 252 62

Ultra-high temperature, light-weight, black ceramic insulation having a density ranging from about 0. 12 g/cc. to 0. 6 g/cc. such as ceramic tile is obtained by pyrolyzing siloxane gels derived from the reaction of at least one organo dialkoxy silane and at least one tetralkoxy silane in an acid or base liquid medium. The reaction mixture of the tetra- and dialkoxy silanes also may contain an effective amount of a mono- or trialkoxy silane to obtain the siloxane gels. The siloxane gels are dried at ambient temperatures and pressures to form siloxane ceramic precursors without significant shrinkage. The siloxane ceramic precursors are subsequently pyrolyzed, in an inert atmosphere, to form the black ceramic insulation comprising atoms of silicon, carbon and oxygen. The ceramic insulation can be characterized as a porous, uniform ceramic tile resistant to oxidation at temperatures ranging as high as 1700Â C. , and particularly useful as lightweight tiles for spacecraft and other high-temperature insulation applications.

6955853, Oct 18, 2005

Jun 9, 2004

10/868450

Huy K. Tran - Mountain View CA, US
Daniel J. Rasky - Palo Alto CA, US
Christine E. Szalai - Santa Clara CA, US
Joseph A. Carroll - Chula Vista CA, US
Ming-ta S. Hsu - San Jose CA, US

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

B32B018/00

428325, 428 364, 428220, 4283124, 4283155, 4283179, 428339, 428408

A low density organic polymer impregnated preformed fibrous ceramic article includes a plurality of layers. A front layer includes ceramic fibers or carbon fibers or combinations of ceramic fibers and carbon fibers, and is impregnated with an effective amount of at least one organic polymer. A middle layer includes polymer impregnated ceramic fibers. A back layer includes ceramic fibers or carbon fibers or combinations of ceramic fibers and carbon fibers, and is impregnated with an effective amount of at least one low temperature pyrolyzing organic polymer capable of decomposing without depositing residues.

46769625, Jun 30, 1987

Aug 28, 1986

6/901496

Salvatore R. Riccitiello - San Jose CA
Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

C01B 3514

423284

The present invention relates to a method of preparing B-trichloroborazine, B. sub. 3 N. sub. 3 Cl. sub. 3 H. sub. 3. Generally, the method includes the combination of gaseous boron trichloride in an anhydrous aprotic organic solvent followed by addition of excess gaseous ammonia at ambient temperature or below. The reaction mixture is heated to between about 100. degree. to 140. degree. C. followed by cooling, removal of the solid ammonium chloride at ambient temperature, distillation of the solvent under vacuum if necessary at a temperature of up to about 112. degree. C. , and recovery of the B-trichloroborazine. Solvents include, toluene, benzene, xylene, chlorinated hydrocarbons, chlorinated aromatic compounds, or mixtures thereof. Toluene is a preferred solvent. The process provides a convenient synthesis of a material which often decomposes on standing.

56187661, Apr 8, 1997

Jul 22, 1996

8/681146

Daniel B. Leiser - San Jose CA
Ming-Ta Hsu - San Jose CA
Timothy S. Chen - San Jose CA

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

C04B 35571
C04B 3558

501 87

Lightweight, monolithic ceramics resistant to oxidation in air at high temperatures are made by impregnating a porous carbon preform with a sol which contains a mixture of tetraethoxysilane, dimethyldiethoxysilane and trimethyl borate. The sol is gelled and dried on the carbon preform to form a ceramic precursor. The precursor is pyrolyzed in an inert atmosphere to form the ceramic which is made of carbon, silicon, oxygen and boron. The carbon of the preform reacts with the dried gel during the pyrolysis to form a component of the resulting ceramic. The ceramic is of the same size, shape and form as the carbon precursor. Thus, using a porous, fibrous carbon precursor, such as a carbon felt, results in a porous, fibrous ceramic. Ceramics of the invention are useful as lightweight tiles for a reentry spacecraft.

52234614, Jun 29, 1993

May 11, 1992

7/880856

Salvatore R. Riccitiello - San Jose CA
Ming-ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

C04B 3552

501 95

The present invention concerns novel high strength ceramic fibers derived from boron, silicon, and carbon organic precursor polymers. The ceramic fibers are thermally stable at and above 1200. degree. C. in air. The method for preparation of the boron-silicon-carbon fibers from a low oxygen content organosilicon boron precursor polymers of the general formula Si(R. sub. 2)BR. sup. 1 by melt-spinning, crosslinking and pyrolysis. Specifically, the crosslinked (or cured) precursor organic polymer fibers do not melt or deform during pyrolysis to form the silicon-boron-carbon ceramic fiber. These novel silicon-boron-carbon ceramic fibers are useful in high temperature applications because they retain tensile and other properties up to 1200. degree. C. , from 1200. degree. to 1300. degree. C. , and in some cases higher than 1300. degree. C.

58143971, Sep 29, 1998

Sep 13, 1995

8/537585

Domenick E. Cagliostro - Berkeley CA
Ming-Ta S. Hsu - San Jose CA

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

B64C 140
B32B 518
B32B 1800

428216

Hygroscopic ceramic materials which are difficult to waterproof with a silane, substituted silane or silazane waterproofing agent, such as an alumina containing, fibrous, flexible and porous, fibrous ceramic insulation used on a reentry space vehicle, are rendered easy to waterproof if the interior, porous surface of the ceramic is first coated with a thin coating of silica. The silica coating is achieved by coating the interior surface of the ceramic with a silica precursor, converting the precursor to silica either in-situ or by oxidative pyrolysis and then applying the waterproofing agent to the silica coated ceramic. The silica precursor comprises almost any suitable silicon containing material such as a silane, silicone, siloxane, silazane and the like applied by solution, vapor deposition and the like. If the waterproofing is removed by, e. g. , burning, the silica remains and the ceramic is easily rewaterproofed.