Polysilocarb-based silicon carbide materials, applications, and equipment

Abstract

To provide a method for producing polysilocarb (SiOC) and silicon carbide (SiC) materials having 3-nines, 4-nines, and 6-nines purities.SOLUTION: There is provided a method of making silicon carbide, the method including: providing a solvent free liquid including silicon, carbon and oxygen; curing the liquid to provide a cured material consisting essential of silicon, carbon and oxygen; holding the cured material at a temperature of less than 150°C; transforming the cured material to a ceramic material consisting essentially of silicon, carbon and oxygen; and removing essentially all of the oxygen from the ceramic material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application claims priority to: (i) U.S. Provisional Application No. 62 / 055,397, filed September 25, 2014, under 35 U.S. SC § 119(e)(1); (ii) U.S. Provisional Application No. 62 / 055,461, filed September 25, 2014, under 35 U.S. SC § 119(e)(1); (iii) U.S. Provisional Application No. 62 / 055,497, filed September 25, 2014, under 35 U.S. SC § 119(e)(1); and (iv) U.S. Provisional Application No. 62 / 112,025, filed February 4, 2015, under 35 U.S. SC § 119(e)(1); all disclosures of each are referenced and incorporated herein. [Background technology]

[0002] Technical field of the present invention The present invention relates to polyorganic compositions, methods, structures and materials; polymer-derived preceramic and ceramic materials and methods; and more particularly to polysilocarb compositions, methods, structures and materials. The present invention further relates to methods for producing silicon carbide (SiC) and SiC compositions, and to structures, components, materials and apparatus for making these items; and more particularly to SiC made from polysilocarb materials. Polysilocarb materials and methods for producing them are disclosed and taught in U.S. Patent Applications No. 14 / 212,896, 14 / 324,056, 14 / 268,150 and 14 / 634,819, the entirety of which is referenced and incorporated herein.

[0003] Materials made from or derived from carbosilane or polycarbosilane (Si-C), silane or polysilane (Si-SI), silazane or polysilazane (Si-N-Si), silicon carbide (SIC), carbosilazane or polycarbosilazane (Si-N-Si-C-Si), siloxane or polysiloxane (Si-O) are known. While the common types of materials are very promising, they have not been realized and have not seen large-scale applications or market acceptance. Instead, their use has been limited to very narrow, restricted, low-volume, high-priced, and highly specific applications (e.g., ceramic components in rocket nozzles or patches for the Space Shuttle). Therefore, they have not been widely used as ceramics. Furthermore, they have little acceptance for other applications.

[0004] To a greater or lesser extent, all these substances and their manufacturing processes have problems such as: they are very expensive, their manufacture is difficult, costing thousands to tens of thousands of dollars per pound; they require high or very high purity starting materials; the processes generally cannot produce high-purity materials; the processes require hazardous organic solvents (e.g., toluene, tetrahydrofuran (THF), and hexane); the materials cannot form unreinforced structures with any usable strength; the processes produce unsuitable and hazardous byproducts, such as sludge that may contain hydrochloric acid and magnesium; the processes involve hardening and thermal decomposition, requiring reaction steps based on multiple solvents and reactants; the materials cannot form useful prepregs; and their overall properties are such that they have good temperature properties but are very brittle.

[0005] As a result, although they were thought to have great potential, these types of materials failed to find large-scale applications or market support, and remained essentially just objects of scientific interest.

[0006] Silicon carbide (SiC) is a silicon (Si) and carbon (C) compound with a wide range of uses, applications, and potential future applications. Eugene Acheson is considered the first developer of a commercial manufacturing process for silicon carbide, and the method is disclosed in U.S. Patent Nos. 492,767 and 560,291, which are referenced and incorporated herein by reference. Silicon carbide is a very versatile material. There are several forms of silicon carbide, such as amorphous crystals with various polytypes, forming single (or mono-) and polycrystalline structures. Silicon carbide has found applications in abrasives, friction components, and electronics. Silicon carbide powder, fine particles, pellets, or other smaller formed forms can be bonded together by sintering operations to form components and structures.

[0007] In general, silicon carbide can function as a semiconductor. As a material, it is very stable. Silicon carbide is an extremely hard material. It is essentially chemically inert and will not react with any other material at room temperature.

[0008] In recent years, there has been a growing but unmet demand for high-purity silicon carbide, and especially for high-purity single-crystal carbide materials, for use in final products (e.g., semiconductors). For example, "Single crystals are gaining increasing importance as substrates for high-frequency and high-power silicon carbide electronic devices." Wang, et al., Synthesis of High Power SiC Powder for High-resistivity SiC Single crystals Growth, p. 118 (J. Mater. SiC. Technol. Vol. 23, No. 1, 2007) (hereinafter Wang). To obtain these high-purity silicon carbide final products, the silicon carbide powder used as a starting material or raw material must be extremely pure. However, "commercially available SiC powder is usually synthesized by the carbon thermal reduction of silica. Unfortunately, it is typically contaminated to a level that makes it unsuitable for SiC growth." Wang, atp. 118. [Overview of the project] [Problems that the invention aims to solve]

[0009] The long-term requirements for obtaining high-purity silicon carbide and the challenges in providing available methods (from a technical and economic standpoint) were also recognized by Zwieback et al., 2013 / 0309496 ("Zwieback"). This is because "the use of high-purity SiC source materials is generally important for SiC single crystal growth. It is also important for semi-insulating SiC crystals." (Zwieback 0007). Zwieback states that conventional methods, including liquid-based methods, have consistently failed to meet this need: "Although numerous improvements to the Acheson process have been developed over the years, the resulting SiC materials always contain high concentrations of boron, aluminum nitrogen, and other metals, making them unsuitable as raw materials for the growth of semiconductor SiC crystals" (Zwieback 0009); "Commercial-grade bulk SiC produced by CVD is not pure enough for use as a source in SiC crystal growth" (Zwieback 0010); liquid processes "produce SiC materials with high concentrations of impurities, making them unsuitable for the growth of semiconductor SiC crystals" (Zwieback 0011); and direct synthesis methods of SiC also provide impure materials that "hinder the use of such materials" (Zwieback 0015). Zwieback himself has spent years trying to address the long-standing need for a complex, multi-step version that appears to be a direct method, aiming to provide high-purity SiC. This process is believed to be technically or economically unfeasible; therefore, it has been unable to solve the long-standing problem of needing to provide high-purity SiC at a commercial level.

[0010] Therefore, there are other known methods for obtaining silicon carbide, but none of these methods are believed to provide the technical, capacity, and economic viability necessary to provide the purity levels, quantities, and low costs required for commercial use and applications; in particular, they are also believed not to meet the ever-increasing demand for semiconductor grade materials and other commercial uses and applications. "Among these synthesis methods, only CVD has been successfully used to produce high purity SiC powder. It is not suitable for mass production due to the high costs associated with CVD technology." Wang, at p. 118.

[0011] CVD generally refers to the chemical vapor deposition method. CVD is a kind of deposition technology. In addition to CVD, deposition technologies include PVD (physical vapor deposition), plasma-enhanced CVD, physical transport growth method (PVT), etc.

[0012] In these end products, uses, and applications that require high purity materials, the need for low-cost silicon carbide raw materials with a purity of at least about 99.9%, at least about 99.99%, at least about 99.999%, at least about 99.9999%, and at least about 99.99999%, or higher, has always been increasing. However, prior to the embodiments of the present invention, for all practical purposes, this need has not been met.

[0013] Furthermore, prior to the embodiments of the present invention, high purity and ultra-high purity SiOC materials have not been obtained, especially in quantities larger than a few ounce small laboratory batches. Therefore, their importance, benefits, and the need for such materials have not been recognized or understood.

[0014] High purity single crystal silicon carbide materials have many desirable features and properties. For example, it is a very hard material with a Young's modulus of about 424 GPa. Due to its granular structure and other factors, polycrystalline silicon carbide also has a very high hardness.

[0015] As used herein, unless otherwise specified, the term "specific gravity" (which is also referred to as "apparent density") is used in the broadest sense and generally refers to the average weight per unit volume of a structure, for example, the weight per volume of a material. This property will include internal air bubbles of the particles as part of its volume. It can be measured with a low-viscosity fluid that wets the particle surface.

[0016] As used herein, unless otherwise specified, the term "actual density" (which is also referred to as "true density") is used in the broadest sense and generally refers to the average weight per unit volume of a structure when there are no pores in the material. This measurement and property essentially removes all internal air bubbles from the material, for example, it does not contain space within the material.

[0017] Therefore, a collection of porous foam balls (e.g., Nerf® balls) can be used to illustrate the relationship of the three density properties. The weight of the balls filling the packaging container will be the bulk density of the balls:

[0018] Bulk density = total weight of balls / volume of the filled container

[0019] The weight of a single ball per unit volume of the spherical volume of the ball will be its apparent density:

[0020] Apparent density = weight of one ball / volume of that ball

[0021] The weight of the material that makes up the skeleton of the ball, i.e., the weight of the ball with all voids removed per remaining volume of that material, will be the actual density:

[0022] Actual density = weight of the material / volume of the material without voids

[0023] As used herein, unless otherwise specified, room temperature is 25°C. Also, standard ambient temperature and pressure are 25°C and 1 atmosphere.

[0024] Generally, when the term “approximately” is used herein, unless otherwise specified, it means to include a range of ±10% as an experimental or instrumental error related to obtaining the indicated value, and preferably a larger range. [Means for solving the problem]

[0025] There is a long-standing unmet need for SiC manufacturing methods, cost-effective and reduced-cost high-purity SiC manufacturing methods and equipment, and equipment utilizing SiC and high-purity SiC. There is also a long-standing unmet need for extremely high purity (e.g., 5-nines) and larger SiC ceramics.

[0026] The present invention solves these needs by providing the manufacture, apparatus and processes for compositions, materials, products and articles disclosed and described herein and in the claims.

[0027] In other words, a method for producing silicon carbide is provided, which includes: providing a liquid containing silicon, carbon, and oxygen and free of solvents; curing the liquid to provide a cured product essentially composed of silicon, carbon, and oxygen; maintaining the cured product at a temperature below 150°C; converting the cured product into a ceramic material essentially composed of silicon, carbon, and oxygen; and essentially removing all oxygen from the ceramic material.

[0028] Furthermore, compositions, methods, and articles having one or more of the following characteristics are provided: a liquid is a polysilocarb precursor formulation having a molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon; a liquid is a polysilocarb precursor formulation having a molar ratio of about 50% to 65% carbon, about 20% to 30% oxygen, and about 15% to 20% silicon; comprising the production of CO; comprising the production of CO2; silicon carbide is produced, and the silicon carbide is of at least 99.99% purity; silicon carbide is produced, and the silicon carbide is of at least 99.999% purity; silicon carbide is produced, and the silicon carbide is of at least 99.9999% purity; silicon carbide is produced, and the silicon carbide is of at least 99.99999% (8 nines) purity; silicon carbide is produced, and the silicon carbide is of at least 99.99999% purity; silicon carbide is produced, and silicon carbide contains less than 100 ppm of Al; silicon carbide is produced, and silicon carbide contains less than 10 ppm of Al; silicon carbide contains less than 1 ppm of Al; silicon carbide is produced, and silicon carbide contains less than 100 ppm of B; silicon carbide is produced, and silicon carbide contains less than 1 ppm of B; silicon carbide contains less than 1 ppm of B; silicon carbide is produced, and silicon carbide contains less than 1000 ppm of total elements, including Ti, Al, Fe, B, P, P Contains impurities selected from Ti, Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ce, Cr, S and As; silicon carbide is produced, and silicon carbide contains impurities selected from Ti, Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ce, Cr, S and As in less than 500 ppm of the total element; silicon carbide is produced, and silicon carbide contains impurities selected from Ti, Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Pr, Ce, Cr, S and As in less than 100 ppm of the total element Contains; silicon carbide is produced, and the silicon carbide contains impurities selected from Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ce, Cr, S and As, less than 100 ppm of the total element; silicon carbide is produced, and the silicon carbide contains impurities selected from Ti, Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ce, Cr, S and As, less than 50 ppm of the total element; the liquid is a polysilocarb precursor formulation, and the silicon carbide is alpha-type; the liquid is po The liquid is a polysilocarb precursor formulation in which silicon carbide is of the beta type; the liquid is a polysilocarb precursor formulation having a molar ratio of approximately 30% to 85% carbon, approximately 5% to 40% oxygen, and approximately 5% to 35% silicon, in which silicon carbide is of the alpha type; the liquid is a polysilocarb precursor formulation having a molar ratio of approximately 30% to 85% carbon, approximately 5% to 40% oxygen, and approximately 5% to 35% silicon, in which silicon carbide is of the beta type; silicon carbide is produced, and the silicon carbide is at least 99%.Silicon is 9999% pure and is alpha-type; Silicon is produced, containing less than 100 ppm of Al and is beta-type; Silicon is produced, containing less than 1 ppm of Al and is beta-type; Silicon is beta-type; Silicon is produced, containing less than 1 ppm of B and is beta-type; Silicon is produced, containing less than 2000 ppm of total elements, selected from Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ti, Ce, Cr, S and As, and is alpha-type. Silicon carbide is produced, and the silicon carbide contains impurities selected from Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ti, Ce, Cr, S, and As, in a total elemental concentration of less than 500 ppm, and the silicon carbide is of the alpha type; Silicon carbide is produced, and the silicon carbide contains impurities selected from Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ce, Cr, S, and As, in a total elemental concentration of less than 100 ppm, and the silicon carbide is of the beta type; Silicon carbide is produced, and the silicon carbide contains impurities selected from the group consisting of Al, Fe, B, P, and Pt, in a total elemental concentration of less than 50 ppm, and the silicon carbide is of the beta type.

[0029] Furthermore, a method for producing silicon carbide is provided, comprising: providing a liquid containing silicon, carbon, and oxygen; where the liquid is a polysilocarb precursor formulation having a molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon; where the liquid material contains elements selected from the group consisting of Al, Fe, B, and P in less than about 100 ppm of the total elements; curing the liquid to obtain a cured product essentially consisting of silicon, carbon, and oxygen; where the cured product is approximately The process involves: including elements selected from the group consisting of Al, Fe, B, and P in less than 100 ppm of the total elements; converting the cured material into a ceramic material containing silicon, carbon, and oxygen; where the ceramic material includes elements selected from the group consisting of Al, Fe, B, and P in less than approximately 100 ppm of the total elements; and essentially removing all oxygen from the ceramic material; thereby providing SiC; where SiC includes elements selected from the group consisting of Al, Fe, B, and P in less than approximately 100 ppm of the total elements.

[0030] Furthermore, compositions, methods, and articles having one or more of the following characteristics are provided: silicon carbide is polycrystalline; silicon carbide is monocrystalline; silicon carbide is more than 99% alpha-type; silicon carbide is more than 50% beta-type; silicon carbide is in a shape selected from the group consisting of packs, briquettes, bricks, tablets, discs, and tablets; silicon carbide is in a volumetric shape, the volumetric shape having less than 1 / 3 the hardness of silicon carbide; silicon carbide is in a volumetric shape, the volumetric shape having less than 1 / 3 the hardness of silicon carbide; silicon carbide is more than 50% beta-type; the liquid is a polysilocarb precursor formulation having a molar ratio of about 50% to 65% carbon, about 20% to 30% oxygen, and about 15% to 20% silicon.

[0031] Furthermore, a method for producing silicon carbide is provided, comprising: catalyzing with a liquid containing silicon, carbon, and oxygen; wherein the liquid is a polysilocarb precursor formulation having a molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon; The catalyzed liquid, At temperatures above 70°C in the presence of an inert gas A solid material containing silicon, carbon, and oxygen with a purity of at least approximately 99.99%. To cure; to heat the cured material at a temperature of 1,750°C or higher. Having a certain hardness Essentially composed of silicon carbide particulate matter Converting to ceramic materials , Here The particulate matter contains less than 10 ppm of Al, Fe, and B in total. nothing; Furthermore, the volumetric shape is made from silicon carbide particulate matter, where the volumetric shape has a hardness of less than 1 / 4 of the hardness of the silicon carbide particulate matter.

[0032] Furthermore, compositions, methods, and articles having one or more of the following characteristics are provided: silicon carbide is a polytype selected from the group consisting of 3C, 2H, 4H, 6H, 8H and 15R; volumetric form is selected from the group consisting of packs, briquettes, bricks, pellets, discs, pills and tablets; the hardness of the volumetric form is less than 1 / 10 of the hardness of silicon carbide particulate matter; the hardness of the volumetric form is less than 1 / 20 of the hardness of silicon carbide particulate matter; silicon carbide is 3C, 2H, 4H, 6H, 8H The polytype is selected from the group consisting of H and 15R; the volumetric form is selected from the group consisting of packs, briquettes, bricks, pellets, discs, pills, and tablets; the hardness of the volumetric form is less than 1 / 10 of the hardness of silicon carbide particulate matter; the hardness of the volumetric form is less than 1 / 30 of the hardness of silicon carbide particulate matter; the polytype of silicon carbide is selected from the group consisting of 3C, 2H, 4H, 6H, 8H, and 15R; the volumetric form is selected from the group consisting of packs, briquettes, bricks, pellets, and tablets. It is selected from a group of forms consisting of squirts, pills, and tablets; the hardness of the volumetric form is less than 1 / 10 of the hardness of silicon carbide particulate matter; the molar ratio of oxygen, carbon, and silicon in the liquid is about 25% Si, about 50% C, and about 25% O; the molar ratio of oxygen, carbon, and silicon in the liquid is about 20% Si, about 60% C, and about 20% O; the molar ratio of oxygen, carbon, and silicon in the liquid is about 23% Si, about 54% C, and about 23% O; silicon carbide is 3C, 2H, The polytype is selected from the group consisting of 4H, 6H, 8H, and 15R; the volumetric form is selected from the group consisting of packs, briquettes, bricks, pellets, discs, pills, and tablets; the hardness of the volumetric form is less than 1 / 10 of the hardness of silicon carbide particulate matter; the molar ratio of oxygen, carbon, and silicon in the liquid is about 22% Si, about 56% C, and about 22% O; the molar ratio of oxygen, carbon, and silicon in the liquid is about 1.37 Si, about 2.73 C, and about 1.37 O.

[0033] Furthermore, compositions, methods, and articles having one or more of the following characteristics are provided: a volumetric silicon carbide product containing elements selected from the group consisting of Al, Fe, B, and P in total less than 50 ppm; a volumetric silicon carbide product containing elements selected from the group consisting of Al, Fe, B, and P in total less than 40 ppm; a volumetric silicon carbide product containing elements selected from the group consisting of Al, Fe, B, and P in total less than 100 ppm; a volumetric silicon carbide product containing elements selected from the group consisting of Al, Fe, B, and P in total less than 1000 ppm; a volumetric silicon carbide product containing Ti, Al, Fe, B, P in total less than 50 ppm The silicon carbide volume contains elements selected from the group consisting of Pt, Ca, Mg, Li, and Na; the silicon carbide volume contains elements selected from the group consisting of Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Pr, Ce, Cr, S, and As in total amounts of less than approximately 50 ppm; the silicon carbide volume contains elements selected from the group consisting of Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ti, Ce, Cr, S, and As in total amounts of less than approximately 50 ppm; the silicon carbide volume contains elements selected from the group consisting of Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Pr, Ce, Cr, S, and As in total amounts of less than approximately 50 ppm.

[0034] Furthermore, compositions, methods, and articles having one or more of the following characteristics are provided: where silicon carbide comprises elements selected from the group consisting of Ti, Al, Fe, B, P, Pt, Ca, Ce, Cr, S, and As in total less than 90 ppm; where silicon carbide comprises elements selected from the group consisting of Ti, Fe, P, Pt, Ca, Mg, Li, Na, Ni, Cr, and As in total less than 90 ppm; where silicon carbide comprises elements selected from the group consisting of Al, Fe, B, P, Mg, Li, V, Ce, Cr, and S in total less than 90 ppm; where silicon carbide comprises elements selected from the group consisting of Al, Fe, B, and P in total less than 90 ppm The silicon carbide contains elements selected from a group consisting of Ti, Al, Fe, B, P, Pt, Ca, Ce, Cr, S, and As, totaling less than 90 ppm; the silicon carbide contains elements selected from a group consisting of Ti, Fe, P, Pt, Ca, Mg, Li, Na, Ni, Cr, and As, totaling less than 90 ppm; the silicon carbide contains elements selected from a group consisting of Al, Fe, B, P, Mg, Li, V, Ce, Cr, and S, totaling less than 90 ppm; the silicon carbide is produced and has a purity of at least 99.9999%; and the silicon carbide is of the beta type.

[0035] Accordingly, a ceramic SiC composition derived from a high-purity polymer is provided, comprising: a SiC4 structure; a surface-defining composition, wherein the surface of the composition is oxidation-resistant under standard ambient temperature and pressure, and the surface is essentially free of oxide film at standard ambient temperature and pressure; and the composition is essentially free of impurities, with a total impurity content of less than 1 ppm.

[0036] Methods, compositions, and articles having one or more of the following features are provided: where the SiC4 structure (SiC4 configuration) is selected from the group consisting of cubic structures and tetrahedral structures; where the SiC4 structure is selected from the group consisting of hexagonal structures, orthorhombic structures and trigonal structures; where the SiC4 structure is selected from the group consisting of 3C-SiC, β-SiC, 2H-SiC, 4H-SiC, 6H-SiC, 8H, 10H, 16H, 18H, 19H, 15R, 21R, 24H, 33R, 39R, 27R, 48H, and 51R; where the SiC4 structure is selected from the group consisting of stacking sequences of ABCABC, ABAB, ABCBABCB, and ABCACBABCACB.

[0037] Furthermore, a semiconductor is provided comprising a SiC wafer made from a high-purity polymer-derived ceramic SiC composition having a band gap, wherein the band gap is from about 2.26 eV to about 3.33 eV.

[0038] Furthermore, a semiconductor is provided comprising a SiC wafer made from a high-purity polymer-derived ceramic SiC composition having a band gap, wherein the band gap is greater than approximately 2.20 eV.

[0039] Furthermore, a semiconductor is provided comprising a SiC wafer made from a high-purity polymer-derived ceramic SiC composition having a band gap, wherein the band gap is from about 2.26 eV to about 3.33 eV.

[0040] Furthermore, a power device is provided that includes a SiC wafer made from a ceramic SiC composition having an Emax derived from a high-purity polymer, wherein the Emax is greater than approximately 1 MV / cm.

[0041] Furthermore, a power device is provided comprising a SiC wafer made from a ceramic SiC composition having an Emax derived from a high-purity polymer, wherein the Emax is greater than approximately 1.5 MV / cm.

[0042] Furthermore, a power device is provided that includes a SiC wafer made from a ceramic SiC composition having an Emax derived from a high-purity polymer, wherein the Emax is greater than approximately 2 MV / cm.

[0043] Furthermore, a power device is provided comprising a SiC wafer made from a ceramic SiC composition having an Emax derived from a high-purity polymer, wherein the Emax is greater than approximately 2.5 MV / cm.

[0044] Furthermore, derived from high-purity polymers, 2x10 7 cm / sec 2 A high-frequency apparatus is provided that includes a SiC wafer made from a ceramic SiC composition having a saturation drift rate.

[0045] Furthermore, articles are provided that are made from a ceramic SiC composition derived from a high-purity polymer and have a thermal conductivity greater than approximately 4.0 W / (cm-K) at room temperature.

[0046] Furthermore, articles are provided that are made from a ceramic SiC composition derived from a high-purity polymer and have a thermal conductivity greater than approximately 4.5 W / (cm-K) at room temperature.

[0047] Furthermore, the following are provided: a fragile material of high-purity polymer-derived ceramic SiC: a granular particulate material of polymer-derived SiC containing a SiC4 structure; a granular particulate material defining a volumetric form; a granular particulate material having an actual density of about 3.0 g / cc to about 3.5 g / cc, an elastic modulus of about 410 GPa and a compressive strength of about 3,900 MPa; a volumetric form having an apparent density of less than about 2.5 g / cc, an elastic modulus of less than about 205 GPa and a compressive strength of less than about 2,000 MPa; where the volumetric form is essentially free of impurities, and impurities selected from the group consisting of Al, Fe, B and P are less than 10 ppm in total.

[0048] Furthermore, methods, compositions, and articles having one or more of the following characteristics are provided: where the volumetric material has a defined surface, and the surface is essentially free of an oxide film; where the volumetric material is selected from the group consisting of packs, briquettes, bricks, pellets, discs, tablets and granules; where the volumetric material is selected from the group consisting of packs, briquettes, bricks, pellets, discs, tablets and granules; where the volumetric material has an elastic modulus of less than about 100 GPa and a compressive strength of less than about 1,000 MPa; where the volumetric material has an elastic modulus of less than about 10 GPa and a compressive strength of less than about 1,000 MPa; where the volumetric material has an elastic modulus of less than about 10 GPa and a compressive strength of less than about 500 MPa; where the volumetric material has an elastic modulus of less than about 10 GPa and a compressive strength of less than about 500 MPa; where the volumetric material has an elastic modulus of less than about 10 GPa and a compressive strength of less than about 500 MPa; a friable material having an impurity of less than about 1 ppm; a friable material in which a SiC4 structure is selected from the group consisting of cubic and tetrahedral structures. A fragile material in which a SiC4 structure is selected from the group consisting of hexagonal, orthorhombic, and trigonal crystal structures (mass); a fragile material in which a SiC4 structure is selected from the group consisting of 3C-SiC, β-SiC, 2H-SiC, 4H-SiC, 6H-SiC, 8H, 10H, 16H, 18H, 19H, 15R, 21R, 24H, 33R, 39R, 27R, 48H, and 51R; a fragile material in which a SiC4 structure is selected from the group consisting of stacking sequences of ABCABC, ABAB, ABCBABCB, and ABCACBABCACB; a fragile material in which a SiC4 structure is selected from the group consisting of stacking sequences of ABCABC, ABAB, and ABCBABCB.

[0049] A SiC layer derived from an epitaxial polysilocarb on a substrate is provided, wherein the SiC layer derived from the epitaxial polysilocarb is made from: a ceramic SiC composition derived from a high-purity polymer comprising: a SiC4 structure; a surface-defining composition, wherein the surface of the composition is oxidation-resistant under standard ambient temperature and pressure, and the surface is essentially free of oxide film at standard ambient temperature and pressure; and wherein the composition is essentially free of impurities, with a total impurity content of less than 1 ppm; and the SiC layer derived from the epitaxial polysilocarb is essentially free of impurities, with impurities content of less than 1 ppm.

[0050] Furthermore, methods, compositions, and articles having one or more of the following characteristics are provided: the impurity is selected from the group consisting of Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ti, Ce, Cr, S, and As; the impurity is selected from the group consisting of Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ti, Ce, Cr, S, and As; here, the impurity is selected from the group consisting of Al, Fe, B, P, and N; here, the impurity is selected from the group consisting of Al, Fe, B, P, and Na; here, the impurity is selected from the group consisting of Al, Fe, B, P, and Na; here, the impurity is selected from the group consisting of Al, B, and P; here, the substrate is composed of SiC; and here, the substrate is composed of Si; here, the substrate is composed of a binder layer and SiOC.

[0051] Furthermore, a SiC layer derived from epitaxial polysilocarb on a substrate is provided, wherein the SiC layer derived from epitaxial polysilocarb is made from the following: high-purity polymer-derived ceramic SiC fragile material comprising: polymer-derived SiC granular particulate matter containing a SiC4 structure; granular particulate matter defining a volumetric form; granular particulate matter having an actual density of about 3.0 g / cc to about 3.5 g / cc, an elastic modulus of about 410 GPa, and a compressive strength of about 3,900 MPa; volumetric form having an apparent density of less than about 2.5 g / cc, an elastic modulus of less than about 205 GPa, and a compressive strength of less than about 2,000 MPa; where the volumetric form is essentially free of impurities, and impurities selected from the group consisting of Al, Fe, and B total less than 10 ppm.

[0052] Furthermore, a polysilocarb-derived SiC boule is provided, comprising: a polysilocarb-derived SiC boule having defined length and diameter, with a length greater than approximately 1 inch and a diameter greater than approximately 2 inches; where the polysilocarb-derived SiC boule is made by vapor deposition of a high-purity polymer-derived ceramic SiC composition comprising: a SiC4 structure; a surface-defining composition, where the composition surface is oxidation-resistant under standard ambient temperature and pressure, and the surface is essentially free of oxide film at standard ambient temperature and pressure; and where the composition is essentially free of impurities, with a total impurity content of less than 1 ppm; the polysilocarb-derived SiC boule is essentially free of impurities, with impurities of less than 1 ppm, and is essentially free of micropipes.

[0053] Furthermore, methods, compositions, and articles having one or more of the following characteristics are provided: a polysilocarb-derived SiC boulder having a length of at least 3 inches; a polysilocarb-derived SiC boulder having a length of at least 5 inches; a polysilocarb-derived SiC boulder having a length of at least 8 inches; a polysilocarb-derived SiC boulder having a length of at least 12 inches; a polysilocarb-derived SiC boulder having a diameter of at least 4 inches; a polysilocarb-derived SiC boulder having a diameter of at least 8 inches. A polysilocarb-derived SiC boolean characterized by having a diameter of at least 10 inches; a polysilocarb-derived SiC boolean characterized by having a diameter of at least 12 inches; a polysilocarb-derived SiC boolean having a diameter of at least 9 inches and a length of at least 4 inches; a polysilocarb-derived SiC boolean having a diameter of at least 10 inches and a length of at least 4 inches; a polysilocarb-derived SiC boolean having a diameter of at least 12 inches and a length of at least 4 inches; a polysilocarb-derived SiC boolean having a diameter of at least 11 inches and a length of at least 4 inches.

[0054] Furthermore, polysilocarb-derived SiC boules are supplied, comprising: a length and diameter defined by the polysilocarb-derived SiC boules, with a length greater than approximately 1 inch and a diameter greater than approximately 2 inches; where the polysilocarb-derived SiC boules are made by vapor deposition of a high-purity polymer-derived ceramic SiC fracturing material comprising: granular particulate matter of polymer-derived SiC, the particles containing a SiC4 structure; granular particulate matter defining the volumetric shape; and a volumetric amount ranging from approximately 3.0 g / cc to approximately 3.5 g / cc. Granular particulate matter having an actual density, an elastic modulus of approximately 410 GPa, and a compressive strength of approximately 3,900 MPa; volumetric material having an apparent density of less than approximately 2.0 g / cc, an elastic modulus of less than approximately 100 GPa, and a compressive strength of less than approximately 1,000 MPa; where the volumetric material is essentially free of impurities, with a total impurity content of less than 10 ppm, selected from the group consisting of Al, Fe, B, P, Ca, Mg, Na, Ni, Cr, S, and As; SiC boules derived from polysilocarb are essentially free of micropipes.

[0055] SiC boules derived from polysilocarb are also provided: here, boules are 5 micropipes / cm 2 It is less than; here, Boolean is 1 micropipe / cm 2 It is less than; here, Boolean is 0.5 micropipes / cm 2 It is less than; and Boolean is 0.1 micropipes / cm 2 Less than;

[0056] Furthermore, a method for producing polysilocarb-derived SiC boules is provided, which defines the length and diameter of the polysilocarb-derived SiC boules, with a length greater than approximately 1 inch and a diameter greater than approximately 2 inches, comprising: where the polysilocarb-derived SiC boules are produced by vapor deposition of a ceramic SiC material derived from a high-purity polymer, the material comprising: granular particulate matter of polymer-derived SiC, the particulate matter comprising a SiC4 structure; the granular particulate matter defining a volumetric shape; approximately Granular particulate matter having an actual density of approximately 3.0 g / cc to 3.5 g / cc, an elastic modulus of approximately 410 GPa, and a compressive strength of approximately 3,900 MPa; volumetric material having a bulk density of less than approximately 2.0 g / cc, an elastic modulus of less than approximately 100 GPa, and a compressive strength of less than approximately 1,000 MPa; where the volumetric material is essentially free of impurities, and the total amount of impurities selected from the group consisting of Al, Fe, and B is less than 10 ppm; and the SiC boule derived from polysilocarb is 1 micropipe / cm 2 It is less than.

[0057] Furthermore, a method for producing polysilocarb-derived SiC boules is provided, which define the length and diameter of the polysilocarb-derived SiC boules, with a length greater than approximately 1 inch and a diameter greater than approximately 2 inches, comprising: where the polysilocarb-derived SiC boules are produced by vapor deposition of a ceramic SiC fracturing material derived from a high-purity polymer, the material comprising: granular particulate matter of polymer-derived SiC, the particulate matter comprising a SiC4 structure; the granular particulate matter defining a volumetric shape; and from approximately 3.0 g / cc to approximately 3. Granular particulate matter having an actual density of 5 g / cc, an elastic modulus of approximately 410 GPa, and a compressive strength of approximately 3,900 MPa; volumetric material having an apparent density of less than approximately 2.0 g / cc, an elastic modulus of less than approximately 100 GPa, and a compressive strength of less than approximately 1,000 MPa; where the volumetric material is essentially free of impurities, and the total amount of impurities selected from the group consisting of Al, Fe, B, P, Ca, Mg, Na, Ni, Cr, S, and As is less than 10 ppm; and SiC boules derived from polysilocarb are essentially free of micropipes.

[0058] A method for producing high-purity silicon oxycarbide is provided, which includes: distillation of a liquid containing silicon, carbon, and oxygen; curing the liquid into a cured product; where the cured product is at least 99.999% pure.

[0059] Methods, compositions, and articles having one or more of the following characteristics are provided: where the liquid is a polysilocarb precursor formulation; where the liquid is a polysilocarb precursor formulation having a molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon; where the liquid is a polysilocarb precursor formulation having a molar ratio of about 50% to 65% carbon, about 20% to 30% oxygen, and about 15% to 20% silicon; where the cured product is at least 99.999% The purity is such that; where the cured product has a purity of at least 99.9999%; where the cured product contains less than 100 ppm of Al; where the cured product contains less than 10 ppm of Al; where the cured product contains less than 1 ppm of Al; where the cured product contains less than 10 ppm of B; where the cured product contains elements selected from the group consisting of Al, Ti, Fe, B, and P in total at or below 100 ppm; where the cured product contains elements selected from the group consisting of Al, Ti, Fe, B, and P in total at or below 50 ppm;

[0060] Furthermore, a method for producing silicon oxycarbide is provided, which includes: distillation of a liquid containing silicon, carbon, and oxygen; curing the liquid into a cured product; and converting the cured product into a ceramic material essentially composed of silicon, carbon, and oxygen.

[0061] Methods, compositions, and articles having one or more of the following characteristics are further provided: where the ceramic material is in a form selected from the group consisting of packs, briquettes, bricks, tablets, and granules; where the ceramic material is in a volumetric form having a hardness less than 1 / 3 of the hardness of the ceramic material; where the ceramic material is in a volumetric form having a hardness less than 1 / 4 of the hardness of the ceramic material;

[0062] Furthermore, a method for producing silicon oxycarbide is provided, which includes: distillation of a liquid containing silicon, oxygen, and carbon; wherein the liquid obtained by distillation is essentially free of impurities; curing the liquid obtained by distillation containing silicon, carbon, and oxygen into a cured product, wherein the cured product is essentially free of impurities; and thermal decomposition of the cured product into a solid product essentially composed of silicon, carbon, and oxygen.

[0063] Methods, compositions, and articles having one or more of the following characteristics are further provided: wherein a liquid obtained by distillation is combined with a second liquid; wherein a liquid obtained by distillation is combined with a polysilocarb precursor; wherein the ratio of silicon, carbon, and oxygen in the cured product is about 25% Si, about 50% C, and about 25% O; wherein the ratio of silicon, carbon, and oxygen in the cured product is about 20% Si, about 60% C, and about 20% O; wherein the ratio of silicon, carbon, and oxygen in the cured product is about 23% Si , is approximately 54% C and approximately 23% O; here, the ratio of silicon, carbon, and oxygen in the cured product is approximately 22% Si, approximately 56% C, and approximately 22% O; and here, the molar ratio of silicon, carbon, and oxygen in the cured product is approximately 1.37 Si, approximately 2.73 C, and approximately 1.37 O; here, the thermally decomposed material is at least 99.99% pure; here, the thermally decomposed material is at least 99.999% pure; and here, the thermally decomposed material is at least 99.9999% pure.

[0064] Furthermore, a method for producing silicon oxycarbide is provided, which includes: distilling a liquid containing silicon, oxygen, and carbon to provide a distilled liquid that is essentially free of impurities; and curing the distilled liquid to obtain a cured product containing silicon, carbon, and oxygen that is essentially free of impurities.

[0065] Furthermore, a method for producing high-purity materials is provided, including: providing a liquid containing silicon, oxygen, and carbon; distilling the liquid to obtain a liquid obtained by distillation; curing the liquid obtained by distillation to obtain a cured product containing silicon, carbon, and oxygen; and thermally decomposing the liquid into a ceramic material essentially composed of silicon, carbon, and oxygen.

[0066] Furthermore, a method for producing high-purity materials is provided, which includes: providing a liquid containing silicon and carbon; distilling the liquid and providing the liquid obtained by distillation; and curing the liquid obtained by distillation to obtain a cured product containing silicon, carbon, and oxygen.

[0067] Furthermore, the present invention provides a method for producing silicon oxycarbide, which includes: distilling a liquid containing silicon, carbon, and oxygen; converting the liquid into a first material containing silicon, carbon, and oxygen; and essentially removing all oxygen from the first material, thereby providing a second material.

[0068] Furthermore, a method for producing high-purity silicon oxycarbide is provided, including: distilling a liquid containing silicon, carbon, and oxygen; and converting a liquid from silicon, oxygen, and carbon into a solid that is essentially composed of silicon, oxygen, and carbon.

[0069] Furthermore, a method for producing silicon oxycarbide is provided, which includes: providing a liquid material containing predetermined amounts of silicon, carbon, and oxygen; distilling the liquid to provide a distilled liquid that is essentially free of impurities; and converting the material by performing a first segment and a second segment, where the first segment provides a cured product containing O, Si, and C, and the second segment provides a ceramic material containing O, Si, and C; and thereby the ceramic material is at least about 99.99% pure.

[0070] Methods, compositions, and articles are provided that include one or more of the following features: where an off-gas is generated, collected, and processed; where the processing of the off-gas is a process selected from the group consisting of burning the off-gas in an afterburner, recovering starting materials from the off-gas, and scrubbing the off-gas. [Brief explanation of the drawing]

[0071] [Figure 1] Figure 1 shows an embodiment of a processing flow diagram according to the present invention.

[0072] [Figure 2A] Figure 2A is a side view perspective of SiC derived from a single cubic polymer according to the present invention.

[0073] [Figure 2B] Figure 2B is a plan view of the SiC cube structure shown in Figure 2A.

[0074] [Figure 3A] Figure 3A is a side view perspective of SiC derived from a tetrahedral polymer according to the present invention.

[0075] [Figure 3B] Figure 3B is a plan view of the SiC tetrahedron structure shown in Figure 3A.

[0076] [Figure 4] Figure 4 is a three-phase diagram according to the present invention.

[0077] [Figure 4A] Figure 4A shows an area of ​​an embodiment of the formulation based on the three-phase diagram of Figure 4 according to the present invention.

[0078] [Figure 4B] Figure 4B shows an embodiment of a transformation that occurs during an embodiment of the process according to the present invention, based on the three-phase diagram of Figure 4.

[0079] [Figure 5]Figure 5 is a schematic diagram of an embodiment of a system for producing polymer-derived SiC and SiC according to the present invention.

[0080] [Figure 6] Figure 6 shows the spectrum of SiC derived from the polymer according to the present invention.

[0081] [Figure 7] Figure 7 is a cross-sectional view of an overview of a vapor deposition apparatus according to the present invention.

[0082] [Figure 8] Figure 8 is a cross-sectional view of an overview of a vapor deposition apparatus according to the present invention.

[0083] [Figure 9] Figure 9 is a cross-sectional view of an overview of a vapor deposition apparatus according to the present invention.

[0084] [Figure 10] Figure 10 shows partial pressure curing for SiC, Si2C, and SiC2. Description of preferred embodiments. [Modes for carrying out the invention]

[0085] Generally, the present invention relates to organosilicon chemistry, polymer-derived ceramic materials and methods; more particularly to methods for producing such materials, polysilocarb (SiOC) and good, high, and very high-purity silicon carbide (SiC) materials; and to the composition, structure, and apparatus of SiC and SiC. Furthermore, embodiments of the present invention relate particularly to the production of high-purity SiC, SiC apparatus, and SiC-containing apparatus and equipment from polysilocarb materials.

[0086] Therefore, the present invention provides a novel material system and a platform for many different formulations, applications, and uses that could not be obtained with conventional silicon-based products. In particular, it provides products that could not be obtained with conventional silicon-based products in terms of acceptable cost, volume, manufacturing conditions, purity levels, handling requirements, and processing conditions.

[0087] Generally, the present invention relates to "polysilocarb" materials, such as materials containing silicon (Si), oxygen (O), and carbon (C), and materials converted from such materials into various forms of SiC. Polysilocarb materials may further contain other elements. Polysilocarb materials are made from one or more polysilocarb precursor formulations or precursor formulations. Polysilocarb precursor formulations include one or more functional silicon polymers or monomers, as well as potentially other components, such as inhibitors, catalysts, initiators, modifiers, dopants, and combinations thereof, and combinations of these and other materials and additives. Unless otherwise specified, the terms silicon-oxycarbide materials, or SiOC compositions and similar terms, refer to polysilocarb materials cured into plastics or solids containing Si, O, and C, and polysilocarb materials thermally decomposed into ceramic materials containing Si, O, and C.

[0088] Polysilocarb formulations, processes and methods, uses, products and articles are taught and disclosed in U.S. Patent Application No. 14 / 268,150, filed 2 May 2014, U.S. Patent Application No. 14 / 634,814, filed 28 February 2015, and U.S. Patent Application No. 14 / 212,896, filed 14 March 14, 2014. The full disclosures of each are referenced and incorporated herein.

[0089] Typically, and preferably, the polysilocarb precursor formulation is initially a liquid. This liquid polysilocarb precursor formulation is then cured to form a solid or semi-solid material (e.g., plastic). The polysilocarb precursor formulation is processed through an initial curing to provide a partially cured product. The partially cured product may be, for example, a preform, a green material, or a green cured product (not a description in terms of the color of the material). The green material may then be further cured. One or more curing steps may be performed. The material can be "finally cured," that is, cured to the point where the material has the required physical strength and other properties for its intended purpose. The amount of curing can be final curing (or "hard cure"), that is, cured to the point where all or essentially all chemical reactions have stopped (measured, for example, by the decrease of reactive groups over time or the absence of reactive groups in the material). Thus, the material can be cured to varying degrees depending on its intended use and purpose. For example, in some situations, final curing and hard curing can be the same.

[0090] Curing can be carried out at standard ambient temperature and pressure ("SATP", 1 atmospheric pressure, 25°C), at temperatures above or below that temperature, at pressures above or below that pressure, and for varying durations (continuously or cyclically, e.g., heating with continuous cooling and reheating), ranging from one minute, several minutes, several hours, to several days (or potentially longer). It can also be carried out in air, liquid, or a pre-selected atmosphere (e.g., argon (Ar), nitrogen (N2)).

[0091] Polysilocarb precursor formulations can be made into unreinforced, unfilled composites, reinforced and filled structures, intermediates and final products, and combinations and variations of these materials, and other types. Furthermore, these structures, intermediates and final products can be cured (e.g., cured greens, final cured bodies, or hard cured bodies), uncured, pyrolyzed into ceramics, or combinations or variations thereof (e.g., cured bodies can be filled with pyrolyzed beads derived from the same polysilocarb as the cured bodies).

[0092] Precursor formulations can be used to form “neat” materials (where the entire or substantially entire structure is made from precursor materials or unfilled formulations, and therefore there are no fillers or reinforcing materials). They can be used to form composite materials (e.g., reinforced products). They can be used to form unreinforced materials. These are materials made primarily from precursor materials, and substantially, preferably solely from precursor materials; for example, a colored polysiloxane structure made simply from precursor materials and a colorant is considered an unreinforced material.

[0093] When polysilocarb precursor formulations are used to create structures, parts, intermediates, or final products, the polysilocarb formulations can be, for example, sprayed, flowed, polymer emulsion processed, heat-sprayed, painted, molded, shaped, extruded, spanned, dropped, injected, or otherwise manipulated to be essentially any volumetric shape, planar shape (which still has volume, more often equivalent to a coating), skin, film, countertop (where the thickness is not orders of magnitude but significantly smaller), combinations and variations thereof.

[0094] Polysilocarb precursor formulations can be used with reinforcing agents to form composite materials. Thus, the formulations can be poured, impregnated, and adsorbed into reinforcing agents such as carbon fibers, glass fibers, fabrics, nonwovens, chopped fibers, metal powders, metal foams, ceramic foams, fibers, ropes, woven structures, ceramic powders, glass powders, carbon powders, graphite powders, ceramic fibers, metal powders, carbide pellets or components, staple fibers, tau, nanostructures of the above, polymer-derived ceramics, other materials that meet the temperature requirements of the process and final product, and combinations and variations thereof. For example, the reinforcing agent can therefore be any high-temperature resistant reinforcing agent currently in use or that can be used, existing plastic and ceramic composite materials. Furthermore, since polysilocarb precursor formulations can be formulated at lower temperatures (e.g., SATP) or cured at curing temperatures of 100°F to 400°F, the reinforcing materials can be polymers, organic polymers such as nylon, polypropylene, and polyethylene, as well as aramid fibers (e.g., NOMEX or KEVLAR®).

[0095] The reinforcing material may be made from or derived from the same material as the formulation that has been made into fibers or pyrolyzed into ceramics, or it may be made from a different precursor formulation material that has been made into fibers or pyrolyzed into ceramics. In addition to ceramic fibers derived from precursor formulation materials that can be used as reinforcing materials, other porous structures, intrinsically porous structures, and non-porous ceramic structures derived from precursor formulation materials may be used.

[0096] Polysilocarb precursor formulations can be used to form a filled material. The filled material can be other solid or semi-solid materials, or materials added to any polysilocarb precursor formulation. The filler material may be selected to provide characteristics of a cured product, a ceramic product, or both. These characteristics relate to aesthetics, touch, thermal properties, density, radiation, chemical properties, magnetic properties, electrical properties, or combinations and variations of these and other characteristics. These characteristics may also include strength. Thus, the filler material may not affect the strength of the cured or ceramic material, may increase the strength, or in some situations may even decrease it.

[0097] Filler materials can provide, restrict, or enhance, for example, electrical insulation, magnetic capability, bandgap characteristics, PN junction characteristics, p-type characteristics, n-type characteristics, dopants, electrical conductivity, semiconductor properties, antistatic properties, optical properties (e.g., reflectivity, refractive index, and discoloration), chemical resistance, corrosion resistance, abrasion resistance, thermal insulation, UV stability, UV coverage, and other desirable, required, or both properties in the product or material.

[0098] Therefore, the filler material can be copper lead wire, thermally conductive filler, conductive filler, lead, optical fiber, ceramic colorant, pigment, oxide, dye, powder, ceramic microparticle, polymer-derived ceramic particles, porous foam, carbosilane, silane, silazane, silicon carbide, carbosilazane, siloxane, metal powder, ceramic powder, metal, metal composite, carbon, tau, fiber, staple fiber, boron-containing material, milled fiber, glass, glass fiber, fiberglass, and the nanostructures mentioned above. For example, pulverized material, polymer-derived ceramic particles, such as microparticles or beads, can be added to a polysilocarb compound and then cured to form a filled, cured plastic material. This material then has important fire resistance in coatings or devices or elements of devices.

[0099] Polysilocarb formulations and products derived from or produced from such formulations can be metallic or metal composites. Therefore, metals as oxides, carbides, or silicon compounds can be introduced into the precursor formulation and thus into the silica matrix in a restrained manner. Thus, the use of organometallic compounds, metal halides (chlorides, bromides, iodides), transition metal metal alkoxides, and metal amide compounds, and subsequent incorporation into the precursor formulation, is intended for copolymerization within the silica matrix.

[0100] For example, transition metal cyclopentadienyl compounds can be used. Transition metal cyclopentadienyl compounds can be classified into two classes: bis-cyclopentadienyl complexes and mono-cyclopentadienyl complexes. Cyclopentadienyl complexes can include C5H5, C5Me5, C5H4Me, and CH5R5 (where R = Me, Et, propyl, i-propyl, butyl, isobutyl, and sec-butyl). In either of these cases, Si can either be directly bound to the cyclopentadienyl ligand, or the Si center can be attached to an alkyl chain and then bound to the cyclopentadienyl ligand.

[0101] Cyclopentadienyl complexes (which can be used in precursor formulations and in products) may include: first-row transition metals (titanium, vanadium, chromium, iron, cobalt, nickel); second-row transition metals (zirconium, molybdenum, ruthenium, rhodium, palladium); third-row transition metals (hafnium, tantalum, tungsten, iridium, osmium, platinum); lanthanides (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho) and bis-cyclopentadienyl metal complexes of the actinide series (Ac, Th, Pa, U, Np).

[0102] Monocyclopentadienyl complexes are used to provide metallic functional groups to precursor formulations and can include monocyclopentadienyl complexes of first-row transition metals (titanium, vanadium, chromium, iron, cobalt, nickel); second-row transition metals (zirconium, molybdenum, ruthenium, rhodium, palladium); and third-row transition metals (hafnium, tantalum, tungsten, iridium, osmium, platinum) when stabilized with a suitable ligand (e.g., chloride or carbonyl).

[0103] Alkyl complexes of metals may also be used to supply metallic functional groups to precursor formulations and products. In these alkyl complexes, the Si center has alkyl groups (ethyl, propyl, butyl, vinyl, propenyl, butenyl) that can directly bond to the transition metal via sigma bonds. Furthermore, this would be more common for the following transition metals (Pd, Rh, Pt, Ir).

[0104] Metal coordination compounds may also be used to provide metallic functional groups to precursor formulations and products. These coordination compounds have an unsaturated alkyl group (vinyl, propenyl, butenyl, acetylene, butadienyl) that can be bonded to a carbonyl or ene complex of Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, or Ni at the Si center. The Si center may be bonded to phenyl, substituted phenyl, or other aryl compounds (pyridine, pyrimidine), or the aryl group may replace the carbonyl on the metal center.

[0105] Metal alkoxides may also be used to provide metallic functional groups to precursor formulations and products. Metal alkoxide compounds can be mixed with silicon precursor compounds and then treated with water to form oxides during polymerization and copolymerization. This can also be done with metal halides and metal amides. Preferably, this may be done in combination with pre-transition metals, such as aluminum, gallium, and indium, and post-transition metals, such as Fe, Mn, Cu, and alkaline earth metals: Ca, Sr, Ba, and Mg.

[0106] When Si is directly bonded to a metal center stabilized by a halide or organic group, the compound may also be used to provide a metallic functional group to the precursor formulation and the product.

[0107] Furthermore, it will be understood that the metal and metal complex may be continuous phases after thermal decomposition or subsequent heat treatment. The formulations can be specifically designed to react with a selected metal in an in-situ form to metal carbides, oxides, and other metal compounds, commonly known as cermets (e.g., ceramic metal compounds). A selected metal and its formulation can be reacted to form in-situ compounds (e.g., mullite, aluminosilicate, etc.). The amounts of silica and metal in the formulation or final product can range from about 0.1 mol% to 99.9 mol%, or be 1 mol% or more, about 10 mol% or more, about 20 mol or more, or more mole percent. The use of precursor formulas and metals in the present invention can be used to control and provide a predefined stoichiometry.

[0108] Polysilocarb batches may be used as binders in composite structures (binders for metal, ceramic, and inorganic matrices).

[0109] The filled material will likely contain reinforcing materials. In many cases, as with the thermal decomposition of polysilocarb, the cured and filled material can be viewed as a composite material. Generally, under this view, the polysilocarb will constitute a bulk or matrix phase (e.g., a continuous or essentially continuous phase), while the filler will constitute a dispersed (e.g., discontinuous) phase.

[0110] However, it should be noted that referring to a material that is "filled" or "reinforced" does not imply that the majority (by weight, volume, or both) of that material is polysilocarb. Therefore, generally, the ratio of polysilocarb to filler material (either by weight or volume) can range from 0.1:99.9 to 99.9:0.1. Small amounts of filler material or polysilocarb may be present or available, but are more typically seen as additives or referred to in other forms. Thus, terms such as composite, filled material, polysilocarb filled material, reinforcing material, polysilocarb reinforcing material, polysilocarb filled material, polysilocarb reinforcing material, and similar terms should be seen as unrestricted in terms of the amount and ratio of material, and given their broadest possible meaning in this context.

[0111] Depending on the specific application, product, or final use, the filler can be distributed evenly or unevenly within the precursor formulation according to the intended settling rate, and can be present in different amounts in different formulations, thereby producing a product with a predetermined amount of filler at a predetermined point, for example, a stepped product with different filler concentrations.

[0112] When used herein, unless otherwise specified, the terms %, weight%, and mass% are interchangeable and refer, for example, to the proportion by weight of a first component to the total weight of a formulation, mixture, material, or product. When used herein, unless otherwise specified, "volume%" and "% volume" and similar terms refer, for example, to the proportion by volume of a first component to the total volume of a formulation, mixture, material, or product.

[0113] At various points in the manufacturing process, polysilocarb structures, intermediates and final products, and combinations and variations thereof, can be machined, crushed, molded, shaped, perforated, or mechanically processed and formed.

[0114] The precursor formulations are preferably transparent or essentially colorless and generally transmit visible wavelengths. Depending on the formulation, they may have an opaque, cloudy, or hazy appearance. Furthermore, they may contain colorants, dyes or colorants, or colored fillers (which can withstand thermal decomposition for the final ceramic product and are used, for example, in ceramic glazes). The precursors may have a yellow, amber color or hue without the need for additional colorants.

[0115] Precursor formulations can be packaged, shipped, and stored for subsequent use in the product (e.g., structures, components). They can also be used directly in these processes (e.g., continuous processes for producing the product). Thus, precursor formulations can be stored, for example, in 55-gallon drums, tank trucks, rail transport vehicles, on-site storage tanks with capacities of several hundred gallons, and 1,000-liter shipping containers. In the manufacturing process, formulations can be produced and used in continuous and semi-continuous processes.

[0116] The formulations of the present invention provide substantial flexibility in design processes, systems, and ceramics to meet predetermined specific performance criteria for processing characteristics and performance characteristics of the final product. For example, the viscosity of the precursor formulation can be predetermined by the formulation to match the specific morphology of the reinforcing material. The curing temperature of the precursor formulation can also be predetermined by the formulation to allow the prepreg to have an extended storage period. The viscosity of the precursor formulation can be established to be sufficiently large so that the precursor flows easily into the reinforcing material of the prepreg, while simultaneously preventing the precursor formulation from flowing out of the reinforcing material. The formulation of the precursor formulation is further configured such that the strength of the cured preform is sufficient to allow rough or initial machining with the preform prior to thermal decomposition.

[0117] When chemical reactions occur at various stages of the process from raw materials to the final product, special and predefined controls can provide cost reduction, increased process control, increased reliability, enhanced efficiency, improved product properties, increased purity, and combinations and variations of these and other benefits. Sequencing of chemical reactions can be based primarily on the treatment or shaping of precursors and the treatment or shaping of precursor formulations; and may also be based on curing and thermal decomposition conditions. Furthermore, special and predefined selections of these steps, formulations, and conditions can provide, preferably predetermined and controlled, enhanced product and processing properties, microstructural arrangement, and rearrangement through chemical reactions, molecular arrangement, and rearrangement.

[0118] Returning to Figure 1, a process path diagram 100 for a collective embodiment, which is several embodiments of the process and system of the present invention, is provided. There is a precursor makeup segment 101 in which a polysilocarb precursor formulation is prepared. There is a formation and distribution segment 102 in which a liquid precursor formulation 103a is prepared for a later segment.

[0119] There is a curing segment 104 in which a liquid precursor 103a is cured into a cured product 103b (which is essentially solid, preferably solid). There is a pyrolysis segment 105 in which the cured product 103b is converted into a ceramic 103c. The ceramic is preferably SiC or SiC, and more preferably high or high-purity SiC or SiC. There is a post-processing segment 108 in which the ceramic 103c is further processed, such as washing, pelletizing, extraction, grinding, sieving, etc. The SiOC ceramic 114 can be used in any number of other segments 106 ("n" in the figure) to make intermediates and final products. Similarly, the post-processed ceramic SiOC 114p can be used in any number of other segments 109 ("n" in the figure) to make intermediates and final products for various applications. Segments 106 and 109 can be the same or different segments. Ceramic SiC113 can be used in any number of other segments 107 to produce intermediates and final products for various applications. Similarly, post-processed ceramic SiC113p can be used in segment 110 (e.g., sintering). Post-processed ceramic SiC113p can be used in segment 111, for example, in a deposition process to form SiC boules in segment 112, for example, the SiC wafer can be used for semiconductors. Post-processed ceramic SiC113p can be used in any number ("n" in the figure) of other segments 115 for intermediates, final products and various applications.

[0120] One of the many advantages of the present invention is that segments 106, 107, 109, 110, 111, and 115 can generally be interchangeable. Furthermore, these segments can be processes, methods, applications, and uses that are traditionally suited to Si. Thus, one of the many advantages of the present invention is the ability to use SiOC, SiC, and combinations of SiOC and SiC, and certain high-purity and extremely high-purity SiOC, SiC and combinations thereof, in Si intermediates, Si final products, Si applications and uses, and in particular Si applications where SiC has traditionally been considered unsuitable for economic, purity, and other rational reasons. More preferably, one of the many advantages of the present invention is the ability to obtain purity levels of SiC that provide performance equal to or better than Si, e.g., properties and functions. Furthermore, one of the many advantages of the present invention is the ability to use SiOC or SiC in intermediates, final products and applications in applications where Si performed poorly or not at all, such as in high-temperature sensors and others, and in new applications.

[0121] For high-purity and extremely high-purity applications, the precursor preparation segments 101 and 102, for example, the apparatus and procedures, should be able to remove, avoid, prevent, and combine all contaminations of the starting material (e.g., materials that would be considered impurities in the final product). Therefore, in embodiments, the segments should be free of (e.g., little, essentially, or completely free of) the following substances: B, Na, Al, P, Fe, heavy metals, and halogens. Distillation, ion exchange filtration, and other types of purification techniques can be used to remove impurities from the starting materials and the raw materials.

[0122] Segments 105, 106, 107, 108, 109, 110 (and 104 if it is combined with another segment), heating equipment, e.g., any type of furnace capable of reaching and maintaining the required temperature, can be used, for example, up to about 2,900°C, up to about 2,800°C, above 2,300°C, preferably in the range of about 1,200°C to about 2,800°C for the thermal decomposition and conversion to SiC. The heating equipment for the curing stage in the process (e.g., segment 104) can be any furnace capable of reaching the curing temperature for curing the liquid polymer-derived ceramic precursor material (e.g., liquid SiC compound) into a cured product (e.g., solid or semi-solid). Thus, one furnace can be used to carry out the entire process from liquid polymer-derived ceramics to SiC. Two or three different furnaces can be used. In this embodiment, one furnace may be used to cure a liquid precursor into a cured SiOC material, and a second or different furnace may be used to convert the SiOC material into SiC.

[0123] Preferably, high purity and extremely high purity applications, materials and uses: for example, SiOC production, SiC production, sintering, pressing, optical formation, Boolean production, signal crystal growth, crystal layer formation, layer formation, coating or wafer production, heating equipment (e.g., furnaces) that are substantially free, preferably free, of any materials that would be considered impurities in the end use. For example, heating equipment, and especially internal components, and all components that are in fluid communication with internal components, are free of (e.g., hardly or essentially free, completely free) the following substances: B, Na, Al, P, Fe and heavy metals. A cleaning or removal cycle can also be performed in the furnace to remove all impurities or contaminants before processing the polymer-derived ceramic material. Thus, for example, vacuum, high-temperature heating cycles, purging with an inert gas, such as argon, combinations and variations of these steps can preferably be used to remove contaminants from the furnace.

[0124] As examples, these furnaces may include: RF furnaces, microwave furnaces, box furnaces, metal tubular furnaces, crystal growth furnaces, arc melting furnaces, induction electric furnaces, kilns, MoSi2 heating element furnaces, gas combustion furnaces, carbon furnaces, and vacuum heating furnaces. The furnaces may also include spacer materials to prevent the materials from coming into contact with each other at high temperatures. For example, graphite in contact with alumina at high temperatures (>1500°C) can lead to aluminum contamination in the final product. Spacers can therefore be used to minimize, mitigate, or prevent this from happening. Preferably, all furnace components are constructed from high-purity graphite. Furthermore, they may be constructed from high-purity SiC or covered with SiC.

[0125] In segments 104, 105, 106, 107, 108, 109, and 110, there may be devices and apparatus that can control the furnace or control the environment inside the furnace; more particularly, the environment adjacent to the material being cured, pyrolyzed, or transformed may be controlled. Thus, devices and apparatus that provide vacuum conditions, reduced pressure, a pre-selected atmosphere (e.g., argon), a smooth gas flow or a sweeping gas flow, and combinations thereof, and variations thereof may be used. These systems and apparatus should be free from contamination into the furnace and should be constructed to minimize, and preferably prevent, the introduction of contaminants or impurities into the furnace, particularly into the material being processed.

[0126] Many polymer-derived ceramic materials, particularly some SiOC materials, can be treated with off-gas processing during pyrolysis and conversion. In some situations, the produced off-gas may be flammable and may contain materials of recoverable value (e.g., Si) and combinations thereof. Therefore, it is also preferable to install off-gas handling equipment (e.g., afterburners) in the furnace to mitigate the flammability problem, and it may also be possible to install off-gas handling equipment (e.g., afterburners) to remove and recover any valuable materials from the gas stream (e.g., gas purification equipment), and combinations thereof, as well as other off-gas stream processing and handling equipment.

[0127] In the various segments of the process shown in Figure 1, material grippers for holding liquid precursor formulations during curing, pyrolysis, conversion, or other transformations can be, for example, alumina, low-binder h-BN, graphite, halogenated purified graphite, pyrolysis graphite, SiC, CVD-SiC, and polymer-derived SiC, PVT-SiC. Various coatings, such as TaC, SiC, and pyrolysis graphite, can be used on these materials. The packaging container can be itself a crucible, a boat, or machined to form any desired geometry (tablet, pack, ellipsoid, ellipsoid, etc.). It may be fully enclosed or not, but may have vents to allow gases to escape. Preferably, a lid attached to the container is used. The container is also designed to allow gas venting during pyrolysis and conversion. Most preferably, an inert gas is also vented through the container and removed, for example, at a volume exchange rate of about 0.5 to about 20 of the container per hour, at a volume exchange rate of about 5 to about 15 of the container per hour, preferably at a volume exchange rate of up to about 10 of the container per hour.

[0128] The arrows in the processing flow (e.g., 150) are for the purpose of general illustration of the embodiment in Figure 1: various segments can be performed step by step or in batch operations. In batch operations, segments can be performed in different locations, separated by time (e.g., hours, days, months or more), or both. Various segments can also be performed as a continuous process; one or more of the various segments can be combined. For example, a single piece of equipment can perform one or more operations of different segments; it can also be a combination and variation of these.

[0129] In the embodiment of the segment shown in Figure 1, the liquid precursor is hardened to solid SiC. The solid SiC is then thermally decomposed and converted to SiC. In one of these embodiments, SiC can be in volumetric shape (e.g., pack, tablet, disc) without the need for intermediate processing steps, and then it is directly converted to SiC crushable material. In one of these embodiments, SiC is crushed into granular SiC and then converted to granular SiC. It is then formed into volumetric shape (e.g., SiC crushable material). In one of these embodiments, SiC is formed into particulate SiC of various sizes. These particulate materials are then crushed to a smaller size, preferably more uniform size, or granules, and then these granules are molded and compressed into, for example, volumetric shape or a mass of SiC. In these, similarly, in other embodiments for producing high-purity or extremely high-purity SiC, it is preferable that the elements of the system are free of substances that are found as impurities in subsequent applications of the SiC or in the SiC process; or these elements may have shielding, enclosure or other mitigation steps to avoid introducing impurities into the process and into the SiC.

[0130] Generally, preferably, embodiments of the precursor formulation have controlled predetermined amounts (e.g., ratios of O, C, and Si). In this embodiment, the SiC starting building block is preferably incorporated into the liquid polymer and preferably locked into the cured product. Subsequently, the processing conditions of the predetermined built starting block can be pre-selected and controlled to obtain the desired final product (e.g., stoichiometrically high purity and extremely high purity SiC). The ratios of the starting building block can be further predetermined and influenced, or otherwise influence the reaction and rearrangement, which can occur during the process, and an initial excess of one component can guide the process in a particular direction to favor the formation of CO over SiO, for example. Thus, by further determining and controlling the ratios of these building blocks, any additives, and processing parameters, it is possible to control and predetermine the type, properties, or form (e.g., polytype) of the resulting SiC.

[0131] For illustrative purposes, the relationship between the starting building block, processing conditions, and final product can be explained in part by referring to the three-phase diagram 400 in Figure 4. Each corner in Figure 400 corresponds to 100% of the building block. Thus, corner 401 is 100% carbon, corner 402 is 100% oxygen, and corner 403 is 100% silicon. Point 404 on Figure 400 corresponds to SiC, point 405 on Figure 400 corresponds to SO2, and points 406 and 407 on Figure 400 correspond to CO2 and CO, respectively. Furthermore, base 410 corresponds to the mole percent of C. 411 on the right corresponds to the mole percent of O. Also, 412 on the left corresponds to the mole percent of Si. (The molar percentage X represents the molar ratio of X to the total molars of O, C, and Si.) Therefore, the molar ratios of the starting materials in a precursor formulation batch are generally, without limitation, about 30% to about 85% carbon, about 5% to about 40% oxygen, and about 5% to about 35% silicon. Preferably, in embodiments of the SiOC starting materials and cured products, the molar ratios of C, Si, and O can be the cross-hatched area 430 in Figure 4A. However, ratios outside that area are also taken into consideration.

[0132] Generally, the process of obtaining SiC involves curing a liquid precursor formulation, thermally decomposing the SiC material, and converting it into SiC material (alpha, beta, or both). During the curing, thermal decomposition, and conversion processes, some of the various building blocks are typically lost, typically C and O. Si is also lost, but preferably the process and precursor are designed to minimize or eliminate Si loss. For example, excess C, built into the precursor, or from an external source, such as in an oven, leads to less Si loss and results in the formation of CO rather than SiO. Greater crosslinking occurring in the cured material results in lower Si loss during thermal decomposition and conversion, and therefore a higher SiC yield.

[0133] Refer to the three-phase diagram 400 in Figure 4B. General changes in ratios that can be expected in various processes are shown. Various arrows are general directions of operation for examples of process activity; their slopes may vary depending on the circumstances, for example, if both hydrocarbons and CO2 are released. Thus, the removal of volatile hydrocarbons will generally change the ratio in the direction of arrow 450. During subsequent curing or storage, the material may pick up some water from the atmosphere, and the change in this case is shown by arrow 451 (combination of water pick-up and volatilization loss). The ratio change from the generation of SiO is shown by arrow 454. The ratio change from the generation of CO is shown by arrow 453. Also, the ratio change from the generation of CO2 is shown by arrow 452. As can be understood, the ultimate goal of the process is to obtain the starting ratio of those materials at baseline 410, and in some circumstances most preferably stoichiometric SiC, point 404.

[0134] For example, the ability to start with a precursor batch of liquid material essentially possesses the building blocks necessary to make SiC, such as Si and C, and has significant advantages in controlling impurities and contamination, which results in the production of high-purity SiOC that can be converted to high-purity SiC or can be produced in a single combined process or step. Thus, embodiments of the present invention provide the formation of SiOC with a purity of at least about 99.9% (3-nines), at least about 99.99% (4-nines), at least about 99.999% (5-nines), at least about 99.9999% (6-nines), and at least about 99.99999% (7-nines) or higher. Similarly, embodiments of the present invention provide the formation of SiC with a purity of at least about 99.9% (3-nines), at least about 99.99% (4-nines), at least about 99.999% (5-nines), at least about 99.9999% (6-nines), and at least about 99.99999% (7-nines) or higher. These purity values ​​are based on the amount of SiC or SiC, and in some cases, on all the material contained in or present in a given sample of SiC or SiC product.

[0135] Embodiments of polysilocarb-derived SiC and processes of the present invention provide increased purity while reducing the cost of high-purity and extremely high-purity SiC. That is, they provide, for example, high-purity SiC materials at a lower cost. Therefore, when compared to the prior art, embodiments of polysilocarb SiC materials and articles reduce costs and improve properties. Thus, embodiments of polysilocarb SiC materials and articles can replace SiC and Si materials in many applications and may provide many novel additional applications where SiC and Si materials could not be used for technical, economic, or both reasons.

[0136] Embodiments of polymer-derived SiC wafers include wafers with a diameter of approximately 2 inches or smaller, wafers with a diameter of approximately 3 inches, wafers with a diameter of approximately 4 inches, wafers with a diameter of approximately 5 inches, wafers with a diameter of approximately 6 inches, wafers with a diameter of approximately 7 inches, wafers with a diameter of 12 inches or larger, and potentially wafers with a diameter of approximately 2 inches to approximately 8 inches, wafers with a diameter of approximately 4 inches to approximately 6 inches, wafers of square, round and other shapes, wafers with a surface area of ​​approximately 1 square inch on one side, approximately The wafers can be 4 square inches, about 10 square inches or more or less, with a thickness of about 100 millimicrons, about 200 millimicrons, about 300 millimicrons, about 500 millimicrons, about 700 millimicrons, about 50 to 800 millimicrons, about 100 to 700 millimicrons, about 100 to 400 millimicrons, or thinner or thicker, and combinations thereof.

[0137] In embodiments of the present invention, high-purity SiC contains materials or impurities that cause significant problems, and in post-processing and manufacturing of items, for example, boules, wafers, electronic components, optical components, and other SiC-based intermediates, as well as in the final product, these materials or impurities are present in low, very low, or below-detection amounts.

[0138] Therefore, high-purity SiC derived from polymers, particularly high-purity SiC derived from polysilocarb, and high-purity SiC from which SiC is converted, have a purity of at least about 99.9%, at least about 99.99%, at least about 99.999%, about 99.9999%, and at least about 99.99999%, or greater. Furthermore, it should be noted that embodiments of the present invention include polymer-derived SiC and SiC of any purity level, such as lower levels of purity, e.g., 99.0%, 95%, 90%, and lower. These lower, e.g., not-so-high purity embodiments have and will find essential uses and applications. Similarly, embodiments of high-purity SiC will find applications. It is also believed that the present invention will offer novel and remarkable advantages to applications prior to SiC or limited to Si materials.

[0139] Embodiments of the present invention involve the use of high-purity SiC in the production of wafers for use in electronics and semiconductor applications. High-purity SiC is required in both the deposition apparatus and the process for creating boulevards and wafers for subsequent use. Embodiments of high-purity polymer-derived SiC and SiC, in particular as described in Table 3, may have low levels of one, more, or all of the elements shown in Table 3 that are considered impurities in deposition apparatus, electronics applications, and semiconductor applications. Thus, embodiments of polysilocarb-derived SiC are essentially impurity-free, or contain impurities in amounts less than or equal to the amounts shown in Table 3 or combinations thereof.

[0140] [Table 1]

[0141] In some embodiments, Pr may also be considered an impurity in certain applications. If so, the ranges and amounts in Table 3 can be applied to Pr.

[0142] Unless otherwise specified herein, the terms purity levels, high purity, % purity, % impurities, and similar terms do not include excess carbon, i.e., carbon beyond the stoichiometric SiC, and are not referenced, considered, or used in the calculation of material properties. In some applications, excess carbon may have no effect on the application or product and would not be considered an impurity. In other applications, excess carbon may be beneficial. For example, carbon can act as a sintering aid; excess carbon can be used to resolve and compensate for irregularities in deposition equipment and processes.

[0143] In applications where nitrogen is considered a contaminant, embodiments of polysilocarb-derived SiC and SiOC may contain nitrogen concentrations of less than approximately 1000 ppm, less than approximately 100 ppm, less than approximately 10 ppm, less than approximately 1 ppm, and less than approximately 0.1 ppm, or less.

[0144] In embodiments of polysilocarb-derived SiC, it is essentially oxygen-free and does not exist in any form, such as bonded to Si or C, or as an oxide film. Therefore, in embodiments of polysilocarb-derived SiC, oxygen may be present in amounts less than approximately 1000 ppm, less than approximately 100 ppm, less than approximately 10 ppm, about 1 ppm, and less than approximately 0.1 ppm, or less. Polysilocarb-derived SiC has resistance to forming an oxide film when exposed to air under standard temperature and pressure. When stored under ambient conditions, the absence of an oxide film, i.e., oxide-free SiC, offers advantages in subsequent manufacturing processes where an oxide film would be recognized as an impurity or otherwise impair the manufacturing process.

[0145] Embodiments of polysilocarb-derived SiC are extremely versatile materials. They can take several forms. For example, they can be amorphous, crystalline with various polytypes, and form single (or mono-) and polycrystalline structures. Combinations of one and more of these forms can be single batches, volumetric materials, or samples of polysilocarb-derived SiC. Thus, the polysilocarb-derived SiC materials of the present invention can find applications in many other fields, including abrasives, friction components, optical components, ballistic and impact-resistant materials, insulation, and electronics.

[0146] SiC powder, fine particles, pellets, or smaller sizes and shapes derived from polysilocarb can be bonded together through sintering operations to form components and structures.

[0147] The polymer-derived SiC embodiments of the present invention can be bonded together, for example, by pressing, sintering, and ready-to-press, using any conventional process and with the use of sintering aids and other additives currently used in conventional processes. The ultrapure polymer-derived SiC embodiments of the present invention are unique and not present in conventional SiC, possessing the ability to bond their particles together without the need for any sintering aids or processing aids. Thus, the ultrapure SiC embodiments of the present invention do not require the presence of sintering aids or additives to be bonded or otherwise molded, for example, by sintering or pressing, into a solid, preferably a single solid form. Self-sintered ultrapure SiC can be significantly stronger than its counterpart made using sintering aids. Therefore, self-sintered SiC molded articles are 2x, 3x, 4x, or more stronger than similar SiC molded articles using sintering aids. Theoretically, sintering aids form bonds or links between SiC particles, and these bonds of sintering aids are inherently weaker than the bonds between self-sintered SiC and SiC (e.g., direct bonds).

[0148] Embodiments of polymer-derived SiC of the present invention, and in particular embodiments in ultrapure SiC, can find applications and uses in broadband amplifiers, military communications, radar, telecom, data links and tactical data links, communication satellite tracking centers and point-to-point radio power electronics, LEDs, lasers, lighting and sensors, through deposition processes, crystal growth processes, bonding processes and other processes. Furthermore, these embodiments can find applications and uses in transistors, such as high electron-mobility transistors (HEMTs), including HEMT-based monolithic microwave integrated circuits (MMICs). These transistors can utilize a distributed (traveling wave) amplifier design approach. The larger bandgap of SiC allows very wide bandwidths to be achieved in a small footprint. Thus, embodiments of the present invention include these devices and articles made from or based on polymer-derived SiC.

[0149] Embodiments of polymer-derived SiC of the present invention, and in particular embodiments of ultrapure SiC, can be used through vapor deposition processes, crystal growth processes, bonding processes and other processes for brake rotors and assemblies, brake discs and pads, raw materials for making gemstones and semi-gemstones, gemstones, moissanite, and for cutting and wear applications. Accordingly, embodiments of the present invention include these devices and articles made from or otherwise based on polymer-derived SiC.

[0150] Embodiments of polymer-derived SiC, and especially ultrapure SiC, of ​​the present invention can be combined with other ceramic powder formulations, providing both improved properties and reduced costs to processes using these other ceramic powders. For example, blends with BN / SiC / ZrO2 compositions and other refractory / engineering ceramic powders, such as AIN, BC, BN, AI2O3, ZrO2, C, SiC, WC, and SiN are intended. Thus, embodiments of the present invention include these devices and articles made from polymer-derived SiC or otherwise based on SiC. Furthermore, they may be used in the alloying of metals, for example, to make cermets or other metallurgical mixtures and alloys. For example, they can be combined with Ti, Fe, Ni, and Co, etc. Thus, for example, they can form polymer-derived SiC-Ti alloys, polymer-derived SiC-iron alloys, polymer-derived SiC-Ni alloys, and polymer-derived SiC-Co alloys.

[0151] Embodiments of the polymer-derived SiC ceramic powder formulations of the present invention can be used, for example, as components such as: furnaces, furnace tubes, furnace belt links, furnace rollers, nozzles, bearings, corrosion-resistant seals, crucibles, refractory structures, insulation systems, RAM jets / SCRAM jets, or anything that flies at Mach 3 or higher, rockets, space shuttles, rocket nose cones and state-of-the-art impact protection systems, SiC / SiC reinforced composites, SiC / C reinforced composites, DC magnetron sputtering targets, thermocouple coatings, pump seals and valve sleeves.

[0152] In embodiments of the polymer-derived SiC, SiOC, and especially ultrapure SiC and SiOC of the present invention, multilayer structures, such as layers on a substrate, can be utilized through deposition processes, crystal growth processes, bonding processes, and other processes. These layers can be crystalline, monocrystalline, polycrystalline, or amorphous. The structure can have many different layers (e.g., substrate layers, bonding layers, SiC layers, SiOC layers, and other materials). In embodiments, sapphire can be used as a substrate for an epitaxial SiC layer. GaN can also be an acceptable substrate. A bonding layer can be used to mitigate inter-lattice mismatches between different crystal lattice parameters. Therefore, for example, when SiOC is used as a substrate, a bonding layer can be used to support SiC or GaN layers grown on the substrate.

[0153] In embodiments of this process, high-purity, polymer-derived SiC is preferably very small in size, for example less than about 100 μm, less than about 10 μm, and has a purity of about 99.999%, preferably about 99.9999% or higher, preferably about 99.99999%, and can be sintered into optical components. These optical components can transmit selected wavelengths (e.g., 360-800 nm). They can have a refractive index of about 2.65 in the visible spectral region. They can have excellent high optical properties and are free from aberration, shielding, and other optical defects. They offer robustness (e.g., the chemical resistance, abrasion resistance, temperature resistance, and hardness of SiC). They can provide significant improvements to windows or transparent screens, such as those in mobile phones, tablets, and touchscreens. They can also be used in the bodies of these devices. These polymer-derived SiC windows can be particularly advantageous in the requirements of use in harsh environments, for example. They can be used in many optical applications, including: light generation, e.g., lasers, laser diodes, and other light sources; shaping and transmitting light (e.g., optical fibers, windows, prisms, lenses, optics, mirrors, internal reflectivity elements (e.g., blocks and prisms that rely on internal reflection to direct light)).

[0154] In addition to UV, visible, and IR light, SiC optical components can be used across wavelengths of electromagnetic radiation, such as microwaves, millimeter waves, X-rays, and high-energy rays.

[0155] Embodiments of polysilocarb-derived SiC, particularly high-purity SiC, possess many unique properties that make them desirable for use in the electrical, solar, and power transmission industries. They are highly stable and can function as suitable semiconductors in several demanding applications, including use in high-power, high-frequency, high-temperature, and corrosive environments. Polymer-derived SiC is an extremely hard material with a Young's modulus of 424 GPa. It is inherently chemically inert and will not react with any material at room temperature.

[0156] Furthermore, prior to the present invention, from a practical standpoint, it was impossible to diffuse substances into silicon carbide, and it was necessary to add dopants to the material to the required extent. The dopants were also added via precursors, present in controlled ways and amounts, and grown within boules or other structures. Embodiments of the precursor formulation may contain dopants, or may contain composites that carry and bond the dopants into the ceramic, which are then converted to SiC, making the dopants available and usable during deposition.

[0157] Furthermore, dopants or other additives that customize or provide predefined properties to wafers, layers, and structures made from polymer-derived SiC and SiOC embodiments can be used with or as part of the polymer-derived materials of the present invention. In these embodiments, such property-enhancing additives are not considered impurities and are intended to be present in the final product. Property-enhancing additives can be incorporated into liquid precursor materials. Depending on the nature of the property-enhancing additive, it may be part of the precursor, or it may be part of a composite or a composite, and it may be incorporated into the liquid precursor or may be in other forms that allow it to remain (e.g., in a form that functions as intended in the final material). Property-enhancing additives can be added to SiC or SiOC powder material as a coating, or added as vapor or gas during processing, or mixed in powder form with polymer-derived SiC or SiOC particulate matter. Furthermore, the form and method of presence of the property-enhancing additive should have minimal, or preferably none, adverse effects on the processing conditions, processing time, and quality of the final product. Therefore, polysilocarb-derived SiC having a purity of 5-nines or higher, 6-nines or higher, and 7-nines or higher may contain property-enhancing additives. These amounts can range from about 0.01% to about 50%, about 0.1% to about 5%, about 1% to about 10%, less than 25%, less than 20%, less than 10%, and less than 1%, although larger or smaller amounts of additives may also be used to impart predefined properties.

[0158] Silicon carbide generally sublimes under vacuum at temperatures above approximately 1800°C, without a liquid phase. See Figure 10, which provides a partial pressure curve for SiC. Typically, in industrial and commercial applications, conditions are established such that sublimation occurs at temperatures above approximately 2,500°C. When silicon carbide sublimes, it typically forms a vapor consisting of Si, SiC, and SiC2. It was generally believed that temperature determined the ratio of these different components in the silicon carbide vapor. However, the present invention provides the ability to pre-select and control the ratio of these components in the SiC vapor by controlling, for example, the amount of excess carbon present in the polysilocarb-derived SiC. In a more controlled manner, the composition of the SiC vapor can be varied in a controlled manner, and can also be varied in a controlled manner over time, by having layers of SiC material containing different predetermined amounts of excess carbon, for example, when used as a starting material in a deposition process, i.e., the porosity of the polysilocarb-derived SiC, the amount of excess carbon present, and both (when used as a starting material in a deposition process).

[0159] SiC derived from polysilocarb, SiC boules, wafers, and other structures made from polysilocarb-derived SiC exhibit polymorphism. Generally, one-dimensional polymorphism is called polytype. Therefore, polysilocarb-derived SiC can be a number of theoretically infinite different polytypes. Unless otherwise clearly noted, the terms “polytypism,” “polytypes,” and similar terms used herein should be given their broadest possible meaning, including the various different frames, structures, or arrangements that constitute the silicon carbide tetrahedron (SiC4). Generally, these polytypes are classified into two categories – alpha (α) and beta (β). Figures 2A, 2B, 3A, and 3B show side and top views, respectively, of single cubic and tetrahedral polymers derived from SiC structures. Figures 2A and 2B show the arrangement of a single cubic SiC, where Si is represented by white circles, e.g., 200, and C by black circles, e.g., 201. Figures 3A and 3B show the arrangement of a single tetrahedron of SiC, where Si is represented by white circles, e.g., 300, and C by black circles, e.g., 301.

[0160] Embodiments of the alpha category of polysilocarb-derived SiC typically include hexagonal (H), orthorhombic (R), trigonal (T) structures, and combinations thereof. The beta category typically includes cubic (C) or zincblende-type structures. Thus, for example, polytypes of silicon carbide derived from polysilocarb include: 3C-SiC (β-SiC or β3C-SiC) (which has a stacking order of ABCABC...); 2H-SiC (which has a stacking order of ABAB...); 4H-SiC (which has a stacking order of ABCBABCB...); 6H-SiC (a general form of α-silicon carbide, α6H-SiC) (which has a stacking order of ABCACBABCACB...). For example, other forms of α-silicon carbide include 8H, 10H, 16H, 18H, 19H, 15R, 21R, 24H, 33R, 39R, 27R, 48H, and 51R.

[0161] Embodiments of SiC derived from polysilocarb can be polycrystalline or monocrystalline. Generally, in polycrystalline materials, grain boundaries exist as interfaces between two grains of the material. These grain boundaries can be between the same polytype with different orientations, between different polytypes with the same or different orientations, and between combinations thereof. A monocrystalline structure consists of a single polytype and essentially has no grain boundaries.

[0162] Embodiments of the present invention provide the ability to meet the demand for high-purity silicon carbide, and especially high-purity single-crystal carbide materials, used in final products such as semiconductors. For these final products and uses that require high-purity materials, low-cost silicon carbide raw materials with purities of at least about 99.9%, at least about 99.99%, at least about 99.999%, about 99.9999%, and at least about 99.99999%, or greater, are desired.

[0163] High-purity single-crystal silicon carbide materials possess many desirable characteristics and properties. For example, it is an extremely hard material with a Young's modulus of 424 GPa. Due to its granular structure and other factors, polycrystalline silicon carbide also exhibits very high hardness.

[0164] Embodiments of polysilocarb-derived SiC according to the present invention have the ability to provide seed crystals, Booleans, and other structures with larger diameters or cross-sections (e.g., 5 inches, larger than 5 inches, about 6 inches, larger than about 7 inches, about 8 inches, larger than 8 inches, larger than 9 inches, about 12 inches, and larger). Such larger diameter or cross-sectional structures have a purity of at least about 99.9%, at least about 99.99%, at least about 99.999%, about 99.9999%, and at least about 99.99999%, or greater.

[0165] Embodiments of the present invention include silicon carbide articles (e.g., semiconductors) having a band gap that varies by polytype, ranging from 2.39 eV for 3C-SiC (beta-SiC) to 3.33 eV for 2H-SiC. 4H-SiC has a band gap of 3.265 eV. α-silicon carbide (6H-SiC) has a band gap of 3.023 eV. These band gaps are larger than those of Si, which has a band gap of 1.11 eV. The high band gap allows silicon carbide materials to operate within sensors (e.g., gas sensors, which are operated in high-temperature environments (e.g., up to about 1000°C)). For example, a silicon carbide-based gas sensor can have a response time of only a few milliseconds when operating at a temperature of about 1000°C.

[0166] Embodiments of materials made from polymer-derived SiC and SiOC, particularly those made from high purity polymer-derived SiC and SiOC, can be utilized in power devices and applications of power devices. For applications of power devices, the breakdown electric field strength Emax can be an important property. This property quantifies the maximum field within the material before material breakdown occurs (e.g., catastrophic breakdown). Emax depends on the doping level, but when comparing SiC materials and Si materials at the same doping level, generally the Emax of SiC can be about 4 to 10 times larger. Emax and the relative Emax can also be viewed from the perspective of the relative strength of devices constructed to have the same blocking voltage. Thus, a Si device configured to have a blocking voltage of 1 kV will have a critical magnetic field strength of about 0.2 mV / cm. Also, a similar SiC device will have a critical magnetic field strength of about 2.49 mV / cm.

[0167] Embodiments of materials made from polymer-derived SiC, SiOC, particularly those made from high purity polymer-derived SiC, SiOC, can be utilized in high frequency devices and high frequency applications. The saturation drift velocity can be an important property of high frequency devices. Silicon carbide has a saturation drift velocity of 2x10 7 cm / sec 2 and the saturation drift velocity of similar silicon is half of that. A high saturation drift velocity has high advantages and is beneficial (if not necessary) for high gain solid state devices. Thus, embodiments of the present invention that provide high purity, low cost (e.g., cost-effective) silicon carbide can be a preferred choice for such devices. However, generally, prior to the present invention, such devices could not be obtained because of the cost associated with the silicon carbide utilized; and because it was difficult, if not impossible, to obtain the required purity.

[0168] Embodiments of materials made from polymer-derived SiC and SiOC, particularly those made from high-purity polymer-derived SiC and SiOC, can be used in applications requiring high thermal conductivity. The thermal conductivity of silicon carbide is higher than that of copper at room temperature. It is also considered to be superior to that of most metals, though not all. For example, the thermal conductivity of silver at room temperature is 4.18 W / (cm-K), and that of copper is 4.0 W / (cm-K). High-purity silicon carbide can have thermal conductivity exceeding approximately 4.0 W / (cm-K), approximately 4.5 W / (cm-K), and even approximately 4.9 W / (cm-K) at room temperature.

[0169] Embodiments of the present invention, and the advances in SiC processing and materials provided by the present invention, can replace silicon materials in many, though not all, electronics and other applications; as well as provide additional and novel applications that can be used beyond conventional silicon-based semiconductor and electronic applications.

[0170] Embodiments of high-purity SiC derived from polysilocarb can have various polytypes and purities, for example, at least about 99.9%, at least about 99.99%, at least about 99.999%, about 99.9999%, and at least about 99.99999%, or higher. High-purity SiC and SiOC derived from polysilocarb can exist as alpha (α), beta (β), and combinations thereof. Embodiments of the alpha category of high-purity SiC derived from polysilocarb typically include hexagonal (H), orthorhombic (R), trigonal (T) structures, and combinations thereof. The beta category of high-purity SiC derived from polysilocarb typically includes cubic (C) or zincblende-type structures. For example, polytypes of high-purity silicon carbide derived from polysilocarb include: 3C-SiC (β-SiC or β3C-SiC); 2H-SiC; 4H-SiC; and 6H-SiC (a common form of α-silicon carbide, α6H-SiC) (which has a stacking order of ABCACBABCACB...). For example, other forms of α-silicon carbide include 8H, 10H, 16H, 18H, 19H, 15R, 21R, 24H, 33R, 39R, 27R, 48H, and 51R. Embodiments of high-purity SiC derived from polysilocarb can be polycrystalline or monocrystalline. High-purity SiC and SiC derived from SiC can be amorphous.

[0171] Embodiments of the present invention include high-purity SiC and SiC in the form of volumetric structures, such as packs, briquettes, bricks, blocks, tablets, pills, plates, discs, squares, balls, rods, and random shapes. These volumetric structures are generally about 1 / 16 in. 3 From about 1 ft 3They come in a wide range of sizes, but larger or smaller sizes are also intended. Embodiments of the volumetric structures are very flexible, brittle, and easily shattered, preferably having the ability to break apart with average hand pressure. Thus, these shatterable SiC volumetric structures can have the following properties: less than about 200 GPa, less than about 150 GPa, less than about 75 GPa, less than about 10 GPa and smaller modulus of elasticity; about 1,400 kg / mm² 2 Less than approximately 800 kg / mm 2 Less than approximately 400 kg / mm 2 Less than approximately 100 kg / mm 2 Hardness less than and lower than; and compressive strength less than approximately 1,850 MPa, less than approximately 1,000 MPa, less than approximately 750 MPa, less than approximately 200 MPa, less than approximately 50 MPa, and lower than; therefore, these fragile SiC volumetric structures are inherently weaker than the underlying SiC material that constitutes their structure, with reported values ​​of approximately 410 GPa modulus, approximately 2,800 kg / mm2 hardness, and approximately 3,900 MPa compressive strength. The actual density of SiC measured by helium specific gravity is approximately 3.0–3.5 g / cc, approximately 3.1–3.4 g / cc, or approximately 3.2–3.3 g / cc. The bulk density (i.e., specific gravity) of fragile volumetric structures of SiC (e.g., pellets, tablets, etc.) can be remarkably low.

[0172] The mass of SiC (e.g., granular SiC particulate matter in volume form, crushable material) preferably has an apparent density that is significantly lower than its actual density. For example, the actual density of SiC granules is about 3.1 g / cc to 3.3 g / cc. Generally and typically, the actual density and apparent density of granular SiC obtained by crushing crushable material are essentially the same. The apparent density of crushable material (e.g., packs, pellets, discs, or plates) is less than about 3 g / cc, less than about 2 g / cc, less than about 1 g / cc, or less, and can be from about 0.5 g / cc to about 1.5 g / cc, or from about 0.4 g / cc to about 2 g / cc. The bulk density of SiC particles is less than about 3.0 g / cc, less than about 2.0 g / cc, less than about 1 g / cc, and from about 0.1 g / cc to about 2 g / cc, or from about 0.5 g / cc to 1.5 g / cc. Larger or lower apparent densities and bulk densities are also intended. Furthermore, the predetermined precise apparent density of polymer-derived SiC fracturing material is increased, and more preferably optimized, for subsequent manufacturing processes. For example, in CVD wafer molding, SiC granular fracturing material can have an apparent density specifically designed and adjusted to fit a particular chemical vapor deposition apparatus. Thus, each chemical vapor deposition apparatus in the facility can have a customized feedstock. The characteristics of each apparatus can be optimized by using a feedstock (e.g., SiC fracturing material) with a predetermined precise apparent density.

[0173] Fragible SiC volumetric materials can be easily and quickly broken down into small particulate materials of SiC with typical SiC strength properties. Smaller particulate materials can have diameters of less than approximately 10 mm, less than approximately 1 mm, less than approximately 0.01 mm, less than approximately 100 μm (millimicrons), less than approximately 10 μm, less than approximately 1 μm, less than approximately 500 nm (nanometers), and less than approximately 100 nm, and even smaller or larger sizes are intended.

[0174] Accordingly, embodiments of the present invention provide for forming a SiC fragile material or volumetric material from an SiC precursor, and obtaining granular SiC from this fragile material. Granular SiC has significantly greater strength than the bulk properties of the SiC fragile material. For example, granular SiC can have an elastic modulus about 2, 3, 4 or more times that of a mass of SiC; granular SiC can have a hardness about 2, 3, 4 or more times that of a mass of SiC; granular SiC can have a compressive strength about 2, 3, 4 or more times that of a mass of SiC; and it can also have the characteristics of a combination of these increased strengths.

[0175] For example, the SiC shatterable material obtained from the process of the embodiment shown in Figure 1 (e.g., 103c of segment 108) can be broken down into granular SiC using a shredding device (e.g., ball mill, attrition mill, rotor stator grinder, hammer mill, jet mill, roller mill, bead mill, media grinder, grinder, homogenizer, 2-plate grinder, dough mixer, or other types of grinding, crushing, and processing equipment).

[0176] SiC fragile materials have an inherent porosity. These pores are preferably open holes, or essentially open pores. Thus, because the granules pack together, the fragile material typically offers an essentially larger usable surface area than granular SiC. Therefore, for example, if fragile disks of SiC were used in a deposition process to create SiC boules (for later conversion to SiC wafers), these fragile SiC disks would provide a substantially larger surface area for generating SiC vapor and would offer essentially larger paths for SiC vapor migration than could typically be obtained from the use of granular SiC in such a process. It is theoretically conceivable that the increased surface area and increased paths would provide the growth rate of SiC boules, the quality of SiC boules (and thus subsequent wafers), and the ability to increase both. Fragile SiC disks (e.g., SiC lumps) are easier to handle, measure, and use than granular SiC material.

[0177] Crushable SiC materials preferably and typically have an apparent density significantly lower than their actual density, for example, an actual density of about 3.2 g / cc. In general, granular SiC (which is obtained by crushing brittle materials) has essentially the same apparent and actual density, for example, about 3.1–3.3 g / cc.

[0178] Compared to the forces required for conventional methods of producing SiC (e.g., carbonothermal reduction of silica, Acheson type, or based thereon), the force required to crush SiC fragile material into granular form is minimal. Conventional methods typically produce batches of monolithic SiC with the strength of SiC, which must typically be broken down to a useful size by crushing, cutting, grinding, or pulverizing. Thus, embodiments of the present invention avoid the need for such heavy or heavy grinding equipment to granulate monoliths of SiC. They further avoid the high cost of the force (e.g., electricity) required to operate such grinding equipment. They further significantly reduce the time required to granulate SiC. Using heavy grinding equipment to granulate monolithic SiC to a useful size could take up to several weeks. On the other hand, embodiments of SiC fragile material of the present invention can be granulated in a few hours, an hour, less than an hour, less than 30 minutes, a few minutes, or less. This pulverization process is, for example, post-processing segment 108 in the embodiment shown in Figure 1.

[0179] High-purity polysilocarb (SiC) offers several advantages and benefits in its use, for example, in Si and carbon sources or starting materials, deposition processes, systems and equipment, and other techniques for growing or creating SiC ingots, structures, articles or volumetric objects. These features include: the ability to have high purity levels; the ability to control high purity levels and particle size distribution (shape, size and both); a predefined particle size distribution; the ability to have volumetric objects; a predefined shape of volumetric objects (e.g., packs, tablets, discs, etc.); the ability to have porosity and controlled porosity; a predefined porosity; the ability to control the amount of carbon; a predefined amount of carbon (i.e., above stoichiometric, below stoichiometric, and above stoichiometric); and combinations of these and other properties. Additional advantages for the present invention are shown through examples. These advantages in the deposition process include shorter growth times for Boules or other structures, longer runtime before cleaning, the ability to optimize equipment, the ability to grow Boules or other structures to larger diameters, the ability to improve quality, the ability to reduce problem areas, the ability to reduce problem areas or occurrences of problems in Boules or other structures (e.g., pipes, blockages, defects), reduced costs, greater control over the process, and combinations thereof.

[0180] It should be understood that the uses described herein are provided for clarity and are not limiting in any sense. Therefore, the processes and disclosures described below should be understood within the context of the entire disclosure herein, including various examples. The uses described herein do not limit the scope of protection of the invention.

[0181] General process for obtaining polysilocarb precursors Typically, polymer-derived ceramic precursor formulations, and certain polysilocarb precursor formulations, can be produced by three types of processes, although other processes and variations and combinations of these processes can also be utilized. These processes generally require the combination of precursors to form a precursor formulation. One type of process is generally preferably solvent-free and essentially non-chemically reactive, involving the mixing of precursor materials, e.g., a "mixing-type process." Another type of process generally involves chemical reactions, including "reaction-type processes" that form customized precursor formulations, which can be monomers, dimers, trimers, and polymers, for example. A third type of process involves the chemical reaction of two or more components in a solvent-free environment (e.g., a "reaction-blending-type process." Generally, during the mixing process, essentially all, preferably all, chemical reactions occur between subsequent processes, e.g., curing, thermal decomposition, and both.

[0182] It should be understood that these terms ("reaction-type process," "reaction-blending-type process," and "mixing-type process") are used for convenience to refer to conventional processes. These terms should not be seen as limiting. For example, a reaction process can be used to create a precursor material that is then used in a mixing process with another precursor material.

[0183] These process types are also used elsewhere in this specification. It should be understood that one process under one heading, and teachings under another, may be applicable to one another under the other heading. Similarly, other sections, embodiments, and teachings within this specification are also applicable. Starting materials or precursor materials in one type of process may be used in another type of process. Furthermore, it should be understood that the processes described under these headings should be read in the context of this specification, including various examples and embodiments.

[0184] It will be understood that combinations and variations of these processes can be used to obtain precursor formulations, intermediates, and final products. Depending on the characteristics of the particular process and product, precursors and starting materials for one process type can be used in other processes. Formulations from a mixed-type process can be used as precursors, components in a reactive-type process, or components in a reactive-blending-type process. Similarly, formulations from a reactive-type process may be used in mixed-type and reactive-blending-type processes. Likewise, formulations from a reactive-blending-type process may be used in mixed-type and reactive-type processes. Therefore, preferably, the best performance and characteristics from other processes can be combined and utilized to provide cost-effective and efficient processes and final products. These processes offer great flexibility in generating customized characteristics for intermediates and final products. And therefore, any of these processes and combinations thereof can provide specific predefined products. Which type of process is desirable can be selected, taking into account factors such as cost, manageability, shelf life, scalability, and ease of manufacture.

[0185] In addition to commercially available materials, precursors may be produced via alkoxylation-type processes (e.g., ethoxylation processes). In this process, ethanol and chlorosilane are reacted in the presence of a catalyst (e.g., HCl) to provide the precursor material. The materials may be reacted further to provide longer-chain precursors. Other alcohols, such as methanol, can also be used. For example, SiCl4, SiCl3H, SiCl2(CH3)2, SiCl2(CH3)H, Si(CH3)3Cl, (Si(CH3)ClH) are reacted with ethanol CH3CH2OH to form precursors. In these reactions, phenol can be the source of the phenoxy group, which is substituted for the hydrogenation group on the silicon. One, two, or more sequential reactions may be required.

[0186] Precursor materials may be obtained via the acetylene reaction route. In general, there are several known paths for adding acetylene to Si-H. For example, acetylene and tetramethylcyclotetrasiloxane can be reacted in the presence of a catalyst to produce tetramethyltetravinylcyclotetrasiloxane. This product can then be ring-opened and polymerized to form a linear vinylmethylsiloxane. Alternatively, typical vinylsilanes can be produced by reacting acetylene with methyl,dichlorosilane (obtained by the direct method or the Rochow process). These monomers can then be cleaned (since they can be scrubbed) to form vinyl, methyl,dichlorosilane. The vinyl monomers can then be polymerized by hydrolysis to form cyclic and linear siloxanes of various chain lengths, such as various cyclotetrasiloxanes (e.g., "D4'") and various cyclopentasiloxanes (e.g., "D5'"). However, these paths are expensive. Furthermore, there has been a long-term increasing need for low-cost raw material sources to produce vinylsilane. Prior to the present invention, it was not believed that MHF could be used in the acetylene addition process to obtain vinylsilane. MHF is cheaper than vinyl and methyl (either linear or cyclic), and producing vinyl by adding acetylene to MHF satisfies the long-term need for a more cost-effective material at a relatively low cost. When performing this addition, the following variables should be considered and controlled: material (D4', linear methyl and hydrogen siloxane fluids); temperature; acetylene-to-Si-H ratio; homogeneous catalyst (Karstedt, dibutylthin dilaurate, no catalyst, Karrstedt with inhibitor, chloroplatinic acid, Ashby); supported catalyst (Pt on carbon, Pt on alumina, Pd on alumina); flow rate (liquid feed, acetylene material); pressure; and catalyst concentration. Examples of reaction embodiments for providing MHF (cyclic and linear) acetylene addition are provided in Tables A and B, where Table A represents batch acetylene reactions and Table B represents continuous acetylene reactions.It should be understood that batch, continuous, and counter-flow MHF and acetylene feeds, continuous recirculation of one-pass material to achieve higher conversion rates, and combinations of these with other processes are available.

[0187] [Table 2]

[0188] [Table 3]

[0189] Embodiments of a continuous high-pressure reactor ("CHPR") are advantageous for the following reasons: the liquid phase reduces the amount of acetylene required for reaction conversion; the tube reactor provides pressure, thus increasing the solubility of acetylene; the reaction with hexine is reduced in concentration and time (e.g., 100 hours); homogeneous catalysts can be removed, and therefore hydrosilylation reactions with vinyl, once obtained, can be eliminated; and the use of heterogeneous (solid) catalysts maintains product integrity, increased shelf life, increased pot life, and combinations thereof.

[0190] Several factors contribute to the ability to handle various states in acetylene addition reactions; dilution, acetylene, and delay of cross-bonding due to lower catalyst concentrations; and the possibility of lower conversion rates (using heterogeneous catalysts) for larger linear molecules compared to smaller molecules.

[0191] The presence and quality of vinyl, and the vinyl conversion rate can be determined by the following: FT-IR for the presence of vinyl absorption, and a decrease in SiH absorption; for the presence of vinyl... 1 HNMR, SiH decrease; presence of vinyl. 13 CNMR.

[0192] When used herein, unless otherwise specified, the terms % and weight%, mass%, are interchangeable and refer to the proportion of the weight of the first component to the total weight of, for example, the formulation, mixture, material, or product. When used herein, unless otherwise specified, the terms "volume%" and "%volume," and similar terms, refer to the proportion of the volume of the first component to the total volume of, for example, the formulation, mixture, material, or product.

[0193] Mixed type process Examples of precursor materials include methyl hydrogen, substituted and modified methyl hydrogen, siloxane backbone adducts, reactive monomers, reaction products of silane modifiers or organic modifiers with siloxane backbone adducts, and other similar types of materials, such as silane-based materials, silazane-based materials, carbosilane-based materials, phenol / formaldehyde-based materials, and combinations thereof. The precursors are preferably liquids at room temperature, but they can be melted and may be solids soluble in one of the other precursors. (However, in this context, one precursor is not considered a "solvent" even if it dissolves another, because in the prior art it is understood to mean a solvent that is not a component (e.g., a solvent that does not form part or components of the final product, or is treated as waste or both).

[0194] The precursors are mixed together in a container, preferably at room temperature. Preferably, little to no solvent (e.g., water, organic solvent, polar solvent, nonpolar solvent, hexane, THF, toluene) is added to this mixture of precursor materials. Preferably, each precursor material is miscible with the others. For example, they can be mixed in any relative amount or in any proportion without separation or precipitation. At this point, “precursor mixture” or “polysilocarb precursor formulation” is competitive (if only one precursor is used, the material is simply “polysilocarb precursor” or “polysilocarb precursor formulation” or “formulation”). Fillers and reinforcing materials can be added to the formulation. In preferred embodiments of the formulation, chemical reactions (e.g., crosslinking or polymerization) occur when the formulation is mixed, when the formulation is in a container, when it is a prepreg, or when it is held for a time before curing. They are essentially absent or not present at all within the formulation.

[0195] The precursors can be mixed under a number of types of atmospheres and conditions, such as air, inert atmosphere, nitrogen, argon, fluid gas, static gas, reduced pressure, pressurized pressure, atmospheric pressure, and combinations thereof.

[0196] Furthermore, inhibitors, such as cyclohexane, 1-ethynyl-1-cyclohexanol (which can be obtained from ALDRICH), octamethylcyclotetrasiloxane, and tetramethyltetravinylcyclotetrasiloxane, can be added to the polysilocarb precursor formulation (e.g., a prohibited polysilocarb precursor formulation). It should be noted that, depending on the amount and temperature, tetramethyltetravinylcyclotetrasiloxane can act as both a reactant and a reaction retarder (e.g., an inhibitor). For example, at room temperature, it acts as an inhibitor, and at high temperatures, it acts as a reactant. Other materials can also be added to the polysilocarb precursor formulation; for example, to a filled polysilocarb precursor formulation during processing, fillers, such as SiC powder, carbon black, sand, polymer-derived ceramic particles, dyes, particulate matter, nanotubes, whiskers, or other materials, as discussed herein or known, can be added at this point. Furthermore, formulations containing both a prohibitor and a filler would likely be considered prohibited, filled polysilocarb precursor formulations.

[0197] Depending on the specific precursors in the polysilocarb precursor formulation and their relative amounts, the polysilocarb precursor formulation can have a shelf life of more than 12 hours, more than 1 day, more than 1 week, more than 1 month, and many years at room temperature. For example, these precursor formulations can have a shelf life of more than 12 hours, more than 1 day, more than 1 week, more than 1 month, and many years at high temperatures, for example, 90°F. The use of inhibitors further extends the shelf life, enables storage at higher temperatures, or provides a combination of these. The use of inhibitors is also beneficial in the development of production and commercial processes by further controlling the reaction rate and ensuring that it occurs in the desired and intended part of the process or production equipment.

[0198] As used herein, the term “shelf life” is understood in its broadest sense unless otherwise specified, for example, the period during which a formulation can be used for its intended purpose or exhibits its properties, for example, the period during which it functions for its intended use and exhibits properties that are 100 percent the same as a fresh formulation, at least about 90% of a fresh formulation, at least about 80% of a fresh formulation, or about 70% of a fresh formulation.

[0199] Precursors and precursor formulations are preferably non-hazardous substances. They preferably have flash points of about 70°C or higher, about 80°C or higher, about 100°C or higher, and about 300°C or higher. Preferably, they are not corrosive. Preferably, they have a low vapor pressure and little or no odor. They are also non-irritating or have little or no skin irritation.

[0200] A catalyst or initiator may be used prior to the curing of the precursor formulation, or added before, immediately before, or earlier when the formulation is formed or a structure is created. The catalyst promotes and accelerates the curing of the precursor formulation and forms a preform.

[0201] After catalytic action is applied, the time period during which the precursor formulation remains useful for curing is called the "pot life," which is how long the catalyzed formulation can remain in its storage container before it should be used. Depending on the specific formulation, the amount of inhibitor used, storage conditions, such as temperature, low O2 atmosphere, and other potential factors, may cause the precursor formulation to have a pot life of approximately 5 minutes to 10 days, approximately 1 to 6 days, approximately 4 to 5 days, approximately 30 minutes, approximately 15 minutes, approximately 1 hour to approximately 24 hours, and approximately 12 to approximately 24 hours.

[0202] The catalyst can be any platinum (Pt)-based catalyst and can be diluted to the following ranges, for example: about 0.01 ppm Pt to about 250 ppm Pt, about 0.03 ppm Pt, about 0.1 ppm Pt, about 0.2 ppm Pt, about 0.5 ppm Pt, 0.02 to 0.5 ppm Pt, about 1 ppm Pt to about 200 ppm Pt, preferably about 5 ppm Pt to about 50 ppm Pt in some embodiments and applications. The catalyst can be a peroxide-based catalyst, for example, having a half-life of 10 hours at 90°C or above, and a concentration between 0.1% and 3%, or about 0.5% to 2%. It can be an organic peroxide. It can be any organometallic catalyst that can react with Si-H bonds, Si-OH bonds, or unsaturated carbon bonds. These catalysts include: dibutyltin dilaurate, zinc octoate, peroxides, organometallic compounds, such as titanium, zirconium, rhodium, iridium, palladium, cobalt, and nickel compounds. The catalysts may also be other rhodium, rhenium, iridium, palladium, nickel, and ruthenium types or catalysts based thereon. Combinations and variations of these and other catalysts may be used. The catalyst may be trade name LUPEROX (e.g., LUPEROX231) obtained from ARKEMA; or trade names obtained from Johnson Matthey: Karstedt catalyst, Ashby catalyst, Speier catalyst.

[0203] Furthermore, customized and specific combinations of these and other catalysts can be used, matched and selected for specific formulations to catalyze the reaction of specific components. Additionally, the use of these types of matched catalyst formulation systems can be used to provide predefined product characteristics, such as porosity, density, density profile, high purity, extremely high purity, other morphological features, or cured structure and ceramic characteristics.

[0204] In this mixed-type process for producing precursor formulations, preferably, chemical reactions or intramolecular rearrangements occur only during the molding, curing, or thermal decomposition processes of the starting materials. Chemical reactions (e.g., polymerization, reduction, condensation, substitution) occur or are utilized during the formation of the starting materials or precursors. When producing polysilocarb precursor formulations by the mixed-type process, chemical reactions and intramolecular rearrangements preferably do not occur, or are essentially absent. These embodiments of the mixed-type process of the present invention avoid the need to utilize polymerization or other reactions during the formation of the precursor formulation. This offers significant advantages over conventional methods for producing polymer-derived ceramics. Preferably, these mixed-type formulations and processes, embodiments of polymerization, crosslinking, or other chemical reactions, preferably occur primarily, essentially, and more preferably only during the curing process.

[0205] The precursor is a siloxane backbone adduct, such as methyl hydrogen (MH), and its formula is shown below.

[0206] [ka]

[0207] MH has a molecular weight ranging from approximately 400 mw to approximately 10,000 mw and from approximately 600 mw to approximately 3,000 mw (where "mw" can be measured as atomic mass units (amu) or weight-average molecular weight as g / mol), and can preferably have a viscosity of approximately 20 cps to 60 cps. The percentage of methylsiloxane units "X" may be from 1% to 100%. The percentage of dimethylsiloxane units "Y" may be from 0% to 99%. This precursor may be used to provide a backbone for a cross-linked structure, and similarly, to provide other features and properties to cured preforms and ceramic materials. This precursor can also be modified by reacting with unsaturated carbon compounds to produce novel or further precursors. Typically, methyl hydrogen fluid (MHF) contains a minimum amount of "Y", more preferably "Y" is 0 for all practical purposes.

[0208] The precursor is a siloxane backbone adduct, such as a vinyl-substituted polydimethylsiloxane, and its formula is shown below.

[0209] [ka]

[0210] This precursor has a viscosity of approximately 400 mW to approximately 10,000 mW and preferably approximately 50 cps to 2,000 cps. The percentage of methyl vinylsiloxane units "X" may be 1% to 100%. The percentage of dimethylsiloxane units may be 0% to 99%. Preferably, X is approximately 100%. This precursor can be used to reduce crosslinking density and improve robustness, and to improve other features and properties of the cured preform and ceramic material.

[0211] The precursor is a siloxane backbone adduct, such as a vinyl-substituted, vinyl-terminated polydimethylsiloxane, whose formula is shown below.

[0212] [ka]

[0213] This precursor may have a molecular weight of approximately 500 mW to approximately 15,000 mW, preferably approximately 500 mW to approximately 1,000 mW, and may preferably have a viscosity of approximately 10 cps to 200 cps. The percentage of methyl vinylsiloxane unit "X" may be 1% to 100%. The percentage of dimethylsiloxane unit "Y" may be 0% to 99%. This precursor may be used to provide branching and reduce curing temperature, and may also be used to improve other features and properties of the cured preform and ceramic material.

[0214] The precursor is a siloxane backbone adduct, such as a vinyl-substituted, hydrogen-terminated polydimethylsiloxane, whose formula is shown below.

[0215] [ka]

[0216] This precursor may have a molecular weight of approximately 300 mW to approximately 10,000 mW, preferably approximately 400 mW to approximately 800 mW, and may preferably have a viscosity of approximately 20 cps to 300 cps. The percentage of methyl vinylsiloxane unit "X" may be 1% to 100%. The percentage of dimethylsiloxane unit "Y" may be 0% to 99%. This precursor may be used to provide branching and reduce curing temperature, and may also be used to improve other features and properties of the cured preform and ceramic material.

[0217] The precursor is a siloxane backbone adduct, such as an allyl-terminated polydimethylsiloxane, whose formula is shown below.

[0218] [ka]

[0219] This precursor has a molecular weight of approximately 400 mW to approximately 10,000 mW and can preferably have a viscosity of approximately 40 cps to 400 cps. The repeating units are the same. This precursor can be used to provide UV curability and extend the polymer chains, and can also be used to improve other features and properties of the cured preform and ceramic material.

[0220] The precursor is a siloxane backbone adduct, such as a vinyl-terminated polydimethylsiloxane, whose formula is shown below.

[0221] [ka]

[0222] This precursor may have a molecular weight of approximately 200 mW to approximately 5,000 mW, preferably approximately 400 mW to approximately 1,500 mW, and a viscosity of preferably approximately 10 cps to 400 cps. The repeating units are the same. This precursor can be used to extend the polymer chain, improve its robustness, and provide a lower curing temperature, such as curing at room temperature, and can also be used to improve other features and properties of the cured preform and ceramic material.

[0223] The precursor is a siloxane backbone adduct, such as a silanol (hydroxy)-terminated polydimethylsiloxane, whose formula is shown below.

[0224] [ka]

[0225] This precursor may have a molecular weight of approximately 400 mW to approximately 10,000 mW, preferably approximately 600 mW to approximately 1,000 mW, and a viscosity of preferably approximately 30 cps to 400 cps. The repeating units are the same. This precursor can be used to extend the polymer chains, provide a mechanism for toughening, generate nano- and micro-scale pores, allow curing at room temperature, and improve other features and properties of the cured preform and ceramic material.

[0226] The precursor is a siloxane backbone adduct, such as a silanol(hydroxy)-terminated vinyl-substituted dimethylsiloxane, whose formula is shown below.

[0227] [ka]

[0228] This precursor may have a molecular weight of approximately 400 mW to approximately 10,000 mW, preferably approximately 600 mW to approximately 1,000 mW, and a viscosity of preferably approximately 30 cps to 400 cps. The percentage of methyl vinylsiloxane unit "X" may be 1% to 100%. The percentage of dimethylsiloxane unit "Y" may be 0% to 99%. This precursor can be used in a dual-curing system; dual-curing allows the use of multiple curing mechanisms in a single formulation. For example, both condensation-type curing and addition-type curing can be utilized. This provides the ability to have a complex curing profile. It provides, for example, initial curing by one type of curing and final curing by different types of curing.

[0229] The precursor is a siloxane backbone adduct, such as a hydrogen (hydride)-terminated polydimethylsiloxane, whose formula is shown below.

[0230] [ka]

[0231] This precursor may have a molecular weight of about 200 mW to about 10,000 mW, preferably about 500 mW to about 1,500 mW, and a viscosity of preferably about 20 cps to 400 cps. The repeating units are the same. This precursor provides a chain extender and toughening agent for polymers, for example, allowing low-temperature curability at room temperature, and can also be used to improve other features and properties of cured preforms and ceramic materials.

[0232] The precursor is a siloxane backbone adduct, such as a diphenyl-terminated siloxane (which may also be called a phenyl-terminated siloxane), and its formula is shown below.

[0233] [ka]

[0234] Here, R is a reactive group, such as vinyl, hydroxyl, or hydride. This precursor has a molecular weight of about 500 mw to about 20,000 mw and can preferably have a viscosity of about 80 cps to 300 cps. The percentage of methyl-R-siloxane units "X" may be 1% to 100%. The percentage of dimethylsiloxane units "Y" may be 0% to 99%. This precursor provides a reinforcing material and can be used to adjust the refractive index of the polymer to match the refractive index of various types of glass, for example, to provide clear fiberglass, and can also provide other features and properties to cured preforms and ceramic materials.

[0235] The precursor is a siloxane backbone adduct, such as a monophenyl-terminated siloxane (which can also be called a trimethyl-terminated, phenyl-terminated siloxane), and its formula is shown below.

[0236] [ka]

[0237] R is a reactive group, such as vinyl, hydroxy, or hydride. This precursor has a molecular weight of about 500 mw to about 20,000 mw and can preferably have a viscosity of about 80 cps to 300 cps. The percentage of methyl-R-siloxane units "X" can be 1% to 100%. The percentage of dimethylsiloxane units "Y" may be 0% to 99%. This precursor provides a reinforcing material and can be used to adjust the refractive index of a polymer to match the refractive index of various types of glass, for example, to provide clear fiberglass, and can also be used to improve other features and properties of cured preforms and ceramic materials.

[0238] The precursor is a siloxane backbone adduct, such as diphenyldimethylpolysiloxane, whose formula is shown below.

[0239] [ka]

[0240] This precursor may have a molecular weight of approximately 500 mW to approximately 20,000 mW, preferably approximately 800 mW to approximately 4,000 mW, and a viscosity of preferably approximately 100 cps to 800 cps. The percentage of dimethylsiloxane units "X" may be 25% to 95%. The percentage of diphenylsiloxane units "Y" may be 5% to 75%. This precursor can be used to provide properties similar to monophenyl-terminated siloxanes and can also be used to improve other features and properties of cured preforms and ceramic materials.

[0241] The precursor is a siloxane backbone adduct, such as a vinyl-terminated diphenyldimethylpolysiloxane, whose formula is shown below.

[0242] [ka]

[0243] This precursor may have a molecular weight of about 400 mW to about 20,000 mW, preferably about 800 mW to about 2,000 mW, and a viscosity of preferably about 80 cps to about 600 cps. The percentage of dimethylsiloxane units "X" may be 25% to 95%. The percentage of diphenylsiloxane units "Y" may be 5% to 75%. This precursor can be used to provide chain extension, reinforcement, a modified or adjusted refractive index, and improved high-temperature thermal stability of the cured product, and can also be used to improve other features and properties of the cured preform and ceramic material.

[0244] The precursor is a siloxane backbone adduct, such as a hydroxy-terminated diphenyl-dimethyl-polysiloxane, whose formula is shown below.

[0245] [ka]

[0246] This precursor can have a molecular weight from about 400 mw to about 20,000 mw, preferably from about 800 mw to about 2,000 mw, and can preferably have a viscosity from about 80 cps to about 400 cps. The percentage of dimethylsiloxane unit "X" can be from 25% to 95%. The percentage of diphenylsiloxane unit "Y" can be from 5% to 75%. This precursor can be used to provide chain extension, reinforcement, an improved refractive index of the cured product with altered or adjusted refractive index and high temperature thermal stability, provide nano or micro-scale porosity, and improve other features and properties to the cured preform and ceramic materials.

[0247] This precursor is a siloxane backbone adduct, such as methyl-terminated phenylethyl polysiloxane (furthermore, it can be called styrene vinylbenzene dimethyl polysiloxane), and the formula is shown below.

[0248]

Chemical formula

[0249] This precursor can have a molecular weight from about 800 mw to at least about 10,000 mw, at least about 20,000 mw, and can preferably have a viscosity from about 50 cps to about 350 cps. The percentage of styrene vinylbenzene siloxane unit "X" can be from 1% to 60%. The percentage of dimethylsiloxane unit "Y" can be from 40% to 99%. This precursor can be used to adjust the refractive index of the polymer to match the refractive index of various types of glass, reduce reaction curing heat generation, and provide improved toughness, for example, to provide transparent fiber glass, and can also be used to improve other features and properties to the cured preform and ceramic materials.

[0250] Various cyclic siloxanes can be used as reactive molecules in formulations. They can be described by the following nomenclature system or formula: DxD * y, here "D" represents the dimethylsiloxy unit. And "D * The symbol "" represents a substituted methylsiloxy unit. The "*" group can be vinyl, allyl, hydride, hydroxy, phenyl, styryl, alkyl, cyclopentadienyl, or other organic groups. x is 0-8, y>=1, and x+y is 3-8.

[0251] The precursor batch may further include non-silicone-based crosslinkers and reaction products of non-silicone-based crosslinkers with siloxane backbone adducts and combinations thereof. Non-silicone-based crosslinkers are intended to provide the ability to crosslink during curing. For example, non-silicone-based crosslinkers that can be used include: cyclopentadiene (CP), methylcyclopentadiene (MeCP), dicyclopentadiene ("DCPD"), methyldicyclopentadiene (MeDCPD), tricyclopentadiene (TCPD), piperine, divinylbenzene, isoprene, norbornadiene, vinylnorbornene, propenylnorbornene, isopropenylnorbornene, methylvinylnorbornene, bicyclonononadiene, methylbicyclonononadiene, propadiene, 4-vinylcyclohexene, 1,3-heptadiene, cycloheptadiene, 1,3-butadiene, cyclooctadiene and its isomers. In general, any hydrocarbon with two (or more) unsaturated, C=C bonds that can react with Si-H, Si-OH, or other Si bonds in the precursor can be used as a crosslinking agent. Some organic substances, including oxygen, nitrogen, and sulfur, may also function as crosslinking sites.

[0252] The precursors can be reactive monomers. These include molecules represented by the following formula, such as tetramethyltetravinylcyclotetrasiloxane ("TV").

[0253] [ka]

[0254] This precursor is a branching agent and is used to provide a three-dimensional crosslinking agent and can also be used to improve other features and properties of the cured preform and ceramic material. (Furthermore, in the formulation, for example, at 2% or more and above a certain temperature, for example, at a temperature from room temperature to about 60 °C, this precursor may act as an inhibitor to crosslinking, for example, it may inhibit the crosslinking of hydrides and vinyl groups.)

[0255] The precursor is a reactive monomer such as trivinyl·cyclotetrasiloxane;

[0256] [Chemical formula]

[0257] divinylcyclotetrasiloxane;

[0258] [Chemical formula]

[0259] trivinyl·monohydridocyclotetrasiloxane;

[0260] [Chemical formula]

[0261] divinyl dihydridocyclotetrasiloxane;

[0262] <000096​​​​​​​​​​​ [ka]

[0265] The precursors are silane modifiers, such as vinylphenyl methyl silane, diphenyl silane, diphenyl methyl silane, and phenyl methyl silane (some of which can be used as end caps or end termination groups). These silane modifiers can provide chain extenders and branching agents. Furthermore, they improve robustness, alter refractive index, improve high-temperature curing stability of the cured product, and increase the strength of the cured product. The precursor, for example, diphenyl methyl silane, may also act as an end coupling agent, which may further improve robustness, alter refractive index, improve high-temperature curing stability of the cured product, and further increase the strength of the cured product.

[0266] The precursor can be a reaction product of a silane modifier and a vinyl-terminated siloxane backbone adduct. The precursor can be a reaction product of a silane modifier and a hydroxy-terminated siloxane backbone adduct. The precursor can be a reaction product of a silane modifier and a hydrate-terminated siloxane backbone adduct. The precursor can be a reaction product of a silane modifier and TV. The precursor can be a reaction product of a silane. The precursor can be a reaction product of a silane modifier and a cyclic siloxane, taking steric hindrance into account. The precursor can be a partially hydrolyzed tetraethyl orthosilicate, e.g., TES40 or Silbond40. The precursor can be methyl sesxyloxane, e.g., SR-350 available from General Electric, Wilton, and Conn. The precursor can be phenyl methyl siloxane, e.g., 604 available from Wacker Chemie AG. The precursor can be methylphenylvinylsiloxane, for example, H62C, which is available from Wacker Chemie AG.

[0267] The precursors can be selected from the following: SiSiB(registered trademark) HF2020, trimethylsilyl-terminated methylhydrosiloxane silicone fluid 63148-57-2; SiSiB(registered trademark) HF2050, trimethylsilyl-terminated methylhydrosiloxane dimethylsiloxane copolymer 68037-59-2; SiSiB(registered trademark) HF2060, hydride-terminated methylhydrosiloxane dimethylsiloxane copolymer 69013-23-6; SiSiB(registered trademark) HF2038 Hydrogen-terminated polydiphenylsiloxane; SiSiB(registered trademark) HF2068, hydride-terminated methylhydrosiloxane-dimethylsiloxane copolymer 115487-49-5; SiSiB(registered trademark) HF2078, hydride-terminated poly(phenyldimethylsiloxy)siloxane-phenyl silsesquioxane, hydrogen-terminated 68952-30-7; SiSiB(registered trademark) VF6060, vinyl-dimethyl-terminated vinylmethyldimethyl polysiloxane copolymer 68083- 18-1; SiSiB(registered trademark) VF6862, vinyldimethyl-terminated dimethyldiphenyl polysiloxane copolymer 68951-96-2; SiSiB(registered trademark) VF6872, vinyldimethyl-terminated dimethylmethylvinyl diphenyl polysiloxane copolymer; SiSiB(registered trademark) PC9401, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane 2627-95-4; SiSiB(registered trademark) PF1070, silanol-terminated polydimethylsiloxane San (OF1070) 70131-67-8; SiSiB (registered trademark) OF1070, silanol-terminated polydimethylsiloxane (70131-67-8; OH-end capped polydimethylsiloxane hydroxy-terminated polydimethylsiloxane 73138-87-1; SiSiB (registered trademark) VF6030, vinyl-terminated polydimethylsiloxane 68083-19-2; SiSiB (registered trademark) HF2030, hydrogen-terminated polydimethylsiloxane fluid, 70900-21-9.

[0268] In addition to the above types of precursors, compounds having the following general formula are also intended as precursors:

[0269] [ka]

[0270] Here, end cappers E1 and E2 are selected from the group, for example, trimethyl silicon (Si(CH3)3), dimethyl silicon hydroxy (Si(CH3)2OH), dimethyl silicon hydride (Si(CH3)2H), dimethyl vinyl silicon (Si(CH3)2(CH=CH2))(Si(CH3)2(C6H5)), and dimethyl alkoxy silicon (Si(CH3)2(OR))). R, R1, R2, R3, and R4 may all be different, or one or more may be the same. For example, R2 may be the same as R3, R3 may be the same as R4, and R1 and R2 may be different from R3 and R4, which are the same group. The R group may be, for example, hydride (-H), methyl (Me)(-C), ethyl (-CC), vinyl (-C=C), alkyl (-R)(-C) n H 2n+1 The group is selected from ), allyl (-CC=C), aryl (-R), phenyl (-Ph)(-C6H5), methoxy (-OC), ethoxyl (-OCC), siloxy (-O-Si-R3), alkoxy (-OR), hydroxy (-OH), phenylethyl (-CC-C6H5), and methyl, phenylethyl (-CC(-C)(-C6H5)).

[0271] Generally, embodiments of a polysilocarb formulation can be, for example, a reaction product of about 0% to 50% MH, about 20% to about 99% MH, about 0% to about 30% siloxane backbone adduct, about 1% to about 60% reactive monomer, about 30% to about 100% TV, and 0% to about 90% siloxane backbone adduct with a silane modifier or organic modifier.

[0272] The mixing time for the formulations should be sufficient to allow the precursors to mix and disperse. Generally, mixing for about 15 minutes to 1 hour is sufficient. Typically, the type of pump or mixing is not important, as precursor formulations are relatively and inherently insensitive to shear forces. It should be noted that higher viscosity formulations require additional mixing time. The temperature of the formulations during mixing should preferably be maintained below about 45°C, and more preferably below 10°C. (It should be noted that these mixing conditions apply to pre-catalyzed formulations.)

[0273] Reaction type process Reaction-type processes are generally used to form precursor formulations, which are chemically reacted with one, two, or more precursors, typically in the presence of a solvent, to form a single polymer that can then be catalyzed, cured, and thermally decomposed. This process offers the ability to construct custom precursor formulations, which, when cured, can provide plastics with unique and desirable properties, such as high-temperature resistance, flame retardancy and non-flammability, strength, and other characteristics. The cured product can also be thermally decomposed to form ceramics with unique properties. Reaction-type processes allow for a predefined balance of different types of functional groups in the final product by selecting the functional groups added to the polymer that makes up the precursor formulation. For example, phenyl is not typically used in ceramics but provides high-temperature properties to plastics, while styrene does not typically provide high-temperature properties to plastics but offers advantages to ceramics.

[0274] Generally, custom polymers used as precursor formulations are produced by reacting precursors in a condensation reaction to form a polymer precursor formulation. This precursor formulation is then cured into a preform through a hydrolysis reaction. The condensation reaction forms the types of polymers shown below.

[0275] [ka]

[0276] R1 and R2 in the polymer unit are hydride (-H), methyl (Me) (-C), ethyl (-CC), vinyl (-C=C), alkyl (-R) (-C) n H 2n+1 ), unsaturated alkyl (-C n H 2n-1 ), cyclic alkyl (-C n H 2n-1 ), allyl (-CC=C), butenyl (-C4H7), pentenyl (-C5H9), cyclopentenyl (-C5H7), methylcyclopentenyl (-C5H6(CH3)), norvonenyl (-C x H Y Here, X=7-15 and Y=9-18), aryl(-R), phenyl(-Ph)(-C6H5), cycloheptenyl(-C7H 11 ), cyclooctenyl (-C8H 13 R1 and R2 can be the same or different. The custom precursor polymer can be a unit of several different polymers, e.g., A1, A2, A n It may have 10, 20 or more units, or it may have just a single unit, for example, the MHF produced by the reaction process may have just a single unit.

[0277] Embodiments may include precursors, including triethoxymethylsilane, diethoxymethylphenylsilane, diethoxyhydridemethylsilane, diethoxymethylvinylsilane, dimethylethoxylvinylsilane, diethoxydimethylsilane, ethoxydimethylphenylsilane, diethoxydihydridesilane, triethoxyphenylsilane, diethoxyhydridetrimethylsiloxane, diethoxymethyltrimethylsiloxane, trimethylethoxylsilane, diphenyldiethoxysilane, dimethylethoxylhydridesiloxane, and combinations thereof with other precursors described herein.

[0278] The end units, Si end 1 and Si end 2, can be derived from precursors of dimethylethoxylvinylsilane, ethoxyldimethylphenylsilane, and trimethylethoxylsilane. Furthermore, if the polymerization process is properly controlled, hydroxy end caps can be obtained from precursors and can provide repeating units of the polymer.

[0279] Generally, a precursor is added to a container containing ethanol (or, for example, another material that absorbs heat to provide thermal mass), excess water, and hydrochloric acid (or another proton source). The mixture is heated until it reaches its activation energy, and the reaction is typically exothermic. Generally, in this reaction, water reacts with the ethoxy group of the silicon of the precursor monomer to form hydroxyl (and ethanol as a byproduct). Once formed, this hydroxyl reacts with the ethoxy on the silicon of another precursor monomer, resulting in a polymerization reaction. This polymerization reaction continues until the desired chain length is constructed.

[0280] The control factors for determining chain length are: the selected monomers (generally, the smaller the monomer, the greater the amount that can be added before they begin to wrap around themselves); the amount and point of the reaction at which end cappers are introduced; and the amount and rate of water addition. Thus, chain lengths range from about 180 mw (viscosity of about 5 cps) to about 65,000 mw (viscosity of about 10,000 cps), greater than about 1,000 mw, greater than about 10,000 mw, greater than about 50,000 mw, and greater than 50,000 mw. Furthermore, the polymerized precursor formulation typically contains polymers of different molecular weights, which are predetermined to provide the formulation, cure, and deliver ceramic product performance.

[0281] Upon completion of the polymerization reaction, the materials are transferred to a separation device (e.g., a separation funnel) containing, for example, about 1.2 to 1.5 times the mass of the materials in deionized water. This mixture is vigorously stirred for less than 1 minute, preferably about 5 to 30 seconds. After stirring, the materials are separated and allowed to precipitate. This takes about 1 to 2 hours. The polymer is a denser material and is removed from the container. The recovered polymer is heated in a shallow tray at 90°C for about 2 hours, or dried by passing it through a wiped film distillation apparatus to remove all residual water and ethanol. Alternatively, enough sodium bicarbonate is added to buffer the aqueous layer to a pH of about 4 to about 7. It is also possible to use other commercially available mixing, reaction, and separation methods for polymers from materials.

[0282] Preferably, a catalyst is used in the curing step of the polymer precursor formulation from a reaction-type process. The same polymer used to cure the precursor formulation from a mixing-type process can be used. Generally, unlike mixing-type formulations, a catalyst is not necessarily required to cure reactive polymers. Inhibitors may also be used. However, if a catalyst is not used, the reaction time and rate will be slower. Curing, and the thermal decomposition of the cured product from a reaction process, are essentially the same as the curing and thermal decomposition of cured products from mixing and reaction-blending processes.

[0283] Reaction-type processes can be carried out under a number of types of atmospheres and conditions, such as air, inert, N2, argon, fluid gas, static gas, reduced pressure, atmospheric pressure, high pressure, and combinations thereof.

[0284] Reaction blending type process In a reaction blending type process, precursors are reacted to form a precursor formulation in the absence of a solvent. For example, in an embodiment of the reaction blending type process, there is a precursor formulation prepared from dicyclopentadiene ("DCPD") and MHF. Using the reaction blending type process, an MHF / DCPD polymer is produced, and this polymer is used as the precursor formulation. (It can be used alone to form a cured or pyrolyzed product, or it can be used as a precursor in a mixed or reaction process.) MHF of known molecular weight and hydride equivalent mass; "P01" (P01 was obtained by diluting a 2% Pt(0) tetravinylcyclotetrasiloxane complex in tetravinylcyclotetrasiloxane 20-fold with tetravinylcyclotetrasiloxane to 0.1% of the Pt(0) complex. Thus, 10 ppm of Pt was provided with the addition of 1% bulk catalyst; 0.20 wt% MHF starting material (known activity equivalent), 40-90%; approximately Dicyclopentadiene with a purity of >83% and 10-60% are used. In embodiments of the process, a sealed reactor equipped with a mixer can be used. The reaction takes place in air within the sealed reactor; other types of atmosphere may also be used. Preferably, the reaction takes place at atmospheric pressure, but higher or lower pressures may also be used. Furthermore, reaction blending type processes can be carried out under a number of types of atmospheres and conditions, such as air, inert, N2, argon, fluid gas, static gas, reduced pressure, atmospheric pressure, high pressure, and combinations thereof.

[0285] In this embodiment, 850 grams of MHF (85% of the total polymer mixture) were added to the reactor and heated to approximately 50°C. Once this temperature was reached, the heater was switched off. 0.20 wt% of P01 platinum catalyst was added to the MHF in the reactor. Typically, the addition of the catalyst generates bubbles and produces an exothermic reaction of approximately 2–20°C.

[0286] When the temperature begins to drop, approximately 150g of DCPD (15% by weight of the total polymer mixture) is added to the reactor. The temperature drops further (for example, to about 5-7°C).

[0287] At this point in the reaction process, the reactor temperature can be controlled to maintain a predetermined temperature profile over time and manage the temperature increase with an exothermic curve. Preferably, the reactor temperature was regulated, monitored, and controlled throughout the entire process.

[0288] In the MHF / DCPD embodiment of the reaction process, the temperature profile may be as follows: The temperature is raised to approximately 80°C (which may take 15-40 minutes depending on the amount of material present); then, as soon as the temperature begins to drop, it rises again, peaking at 104°C. The heater setting temperature is raised to 100°C. The reaction mixture temperature is also monitored to ensure that the polymer temperature is maintained above 80°C for a minimum of approximately 2 hours and a maximum of approximately 4 hours. After maintaining above 80°C for 2-4 hours, the heater is turned off and the polymer is cooled to ambient temperature. For larger or smaller batches, continuous, semi-continuous, and other types of processes, the temperature and time profiles may differ.

[0289] Batch, continuous, and combinations thereof can be used in large-scale and commercial operations. Industrial factory automation and control systems can be used to control the reaction, temperature profile, and other processes during the reaction.

[0290] Table C shows various embodiments of the reaction blending process.

[0291] [Table 4]

[0292] In the table above, "Degree of Polymerization" is the number of monomer units, or repeating units, bonded together to form the polymer. "Equivalents / mol" refers to molar equivalents. "Grams / mol of vinyl" refers to the amount of a given polymer required to provide one molar equivalent of vinyl functional groups. "VMH" refers to methyl vinyl fluid (linear vinyl material from the ethoxyl process). This can be used instead of TV. The number "0200" for VT is the viscosity as centipoise for that VT.

[0293] Hardening and thermal decomposition As with other materials, precursor formulations containing polysilocarb precursor formulations from the above-described types of processes can be cured to become solid, semi-solid, or plastic-like materials. Typically, the precursor formulation is stretched, shaped, or otherwise preformed, which can contain any volumetric structures or excipients, including thin and thick films. During curing, the polysilocarb precursor formulation is treated through initial curing to provide a partially cured product, which is also called, for example, a preform, green material, or green cured product (not a description of the color of the material). The green material may then be further cured. Thus, one or more curing steps may be used. The material can be cured to a "final curing" point, i.e., a point where the material has the physical strength and other properties required for its intended purpose. The amount of curing can be final curing (or "hard curing"). At that point, all or essentially all chemical reactions cease (measured, for example, by the absence of reactive groups in the material or the lack of a decrease in reactive groups over time). Therefore, materials can be cured to varying degrees, depending on their intended use and purpose. For example, in some situations, final curing and hard curing can be the same. Curing conditions, such as atmosphere and temperature, can affect the cured material composition.

[0294] When constructing a precursor formulation into a structure or preform, the precursor formulation (e.g., polysilocarb formulation) can be formed using, for example, the following techniques: spraying, spray drying, atomization, atomization, phase transition separation, flow spreading, thermal spraying, tensile, dripping, droplet formation in liquid and liquid surfactant systems, coating, molding, shaping, extrusion, spinning, ultrasonic shaping, vibration shaping, solution polymerization, emulsion polymerization, microemulsion polymerization, injection, injection molding, or other methods for forming essentially any volumetric shape. The shapes of the volumetric shapes include, for example, spheres, pellets, rings, lenses, discs, panels, cohenes, frustocones, squares, rectangles, trusses, angles, channels, hollow sealed chambers, hollow spheres, blocks, sheets, coatings, films, skins, microparticles, beams, rods, slabs, columns, fibers, staple fibers, tubes, cups, pipes, and combinations thereof, as well as other more complex shapes that can be both engineering and structural.

[0295] The molding, curing, and pyrolysis processes can be batch processes, sequential processes with time delays (e.g., materials are stored or held between steps), combinations thereof, variations thereof, and other types of processing sequences. Furthermore, the precursor material can be partially cured. Alternatively, the curing process can be started and carried out before the precursor material is formed into a volumetric shape. These steps, and various combinations thereof, can be under controlled predetermined conditions (e.g., the material is exposed to a predefined atmosphere and temperature profile throughout the process, e.g., reduced oxygen, a cured preform temperature held at approximately 140°C prior to pyrolysis), which is preferred in some embodiments. The systems, apparatus, or processing steps for molding, curing, and pyrolysis can be the same apparatus, a sequential apparatus, a batch and linked apparatus, combinations thereof, and other types of industrial processes. Thus, for example, spray drying technology can form cured particulate matter, which can be directly supplied to a fluidized bed reactor for pyrolysis.

[0296] Polysilocarb precursor formulations can be made into neat, unreinforced, unfilled composites, reinforced, filled intermediates, structures, final products, combinations thereof, and other types of materials. Furthermore, these structures, intermediates, and final products can be cured (e.g., green cured, final cured, or hard cured), uncured, thermally decomposed into ceramics, and combinations thereof (e.g., the cured material can be filled with thermally decomposed material derived from the same polysilocarb as the cured material). Precursor formulations can be used to form “neat” materials (a “neat” material is one in which all or essentially all of the structure is made from precursor materials or unfilled formulations; and therefore, there are no fillers or reinforcing materials).

[0297] Polysilocarb precursor formulations can be used to form prepregs by coating or impregnating woven or nonwoven fabrics made from fibers, such as carbon fibers, glass fibers, or polysilocarb precursor formulations (same or different formulations). Thus, polysilocarb precursor formulations can be used to form composite materials (e.g., reinforced products). For example, formulations can be used as reinforcing materials. For example, carbon fibers, glass fibers, woven fabrics, graphene, carbon nanotubes, thin films, precipitates, sand, nonwoven fabrics, chopped fibers, fibers, ropes, woven structures, ceramic powders, glass powders, carbon powders, graphite powders, ceramic fibers, metal powders, carbides, pellets, or compositions can be combined with reinforcing materials by pouring, impregnating, and absorbing staple fibers, tau, nanostructures of the above, polymer-derived ceramics, any other materials that meet the temperature requirements of the process and final product, or combinations thereof. The reinforcing material may be made from or derived from the same material as the formulation formed into fibers and thermally decomposed into ceramics, or it may be a different precursor formulation that has been formed into fibers and thermally decomposed into ceramics.

[0298] Polysilocarb precursor formulations can be used to form a filled material. The filled material will be other solid or semi-solid materials added to the polysilocarb precursor formulation. Filler materials may be selected to provide certain characteristics to the cured product, the ceramic product, or both. For example, these characteristics can be aesthetic, tactile, thermal, density, radiation, chemical, cost, magnetic, electrical, or a combination of these and other characteristics. These characteristics may also be strength. Thus, filler materials do not necessarily affect the strength of the cured product or ceramic material. It can reduce strength in some situations. Filler materials can impart color, magnetic ability, fire resistance, flame retardancy, heat resistance, electrical conductivity, antistatic properties, optical properties (e.g., reflectivity, refractive index, and discoloration), aesthetic properties (stone-like appearance in building construction), chemical resistance, corrosion resistance, abrasion resistance, low cost, wear resistance, thermal insulation, UV stability, UV protection properties, and other characteristics that are desirable or necessary for the final product or material. Therefore, filler materials include carbon black, copper lead wire, thermally conductive filler, conductive filler, lead, optical fiber, ceramic colorant, pigment, oxide, sand, dye, powder, ceramic powder, polymer-derived ceramic particles, pore-forming agent, carbosilane, silane, silazane, silicon carbide, carbosilazane, siloxane, powder, ceramic powder, metal, metal composite, carbon, tau, fiber, staple fiber, boron-containing material, milled fiber, glass, glass fiber, fiberglass, and nanostructures (including nanostructures of the above materials).

[0299] Polysilocarb formulations, and products derived from or made from such formulations, may contain metals and metal composites. Filled materials will contain reinforcing materials. In many cases, pyrolyzed polysilocarb fillers can be viewed as composite materials. Generally, under this view, polysilocarb will constitute a bulk or matrix phase (e.g., a continuous phase or essentially a continuous phase). The filler will also constitute a dispersed phase (e.g., a discontinuous phase). Depending on the specific application, product, or end use, the filler can be uniformly dispersed, non-uniformly dispersed, dispersed with a predetermined and controlled distribution gradient (e.g., a predetermined precipitation rate), and can be contained in different amounts within different formulations. This is then formed into a product having a predetermined amount of filler in a predetermined region (e.g., striped layers with different filler concentrations). However, it should be noted that the term "filled" or "reinforced" does not necessarily imply that the majority of that material (by weight, volume, or both) is polysilocarb. Therefore, generally, the ratio of polysilocarb to filler material (either by weight or volume) can be approximately 0.1:99.9 to 99.9:0.1.

[0300] Polysilocarb precursor formulations may be used to form unreinforced materials. These are primarily, and preferably, made solely from precursor materials; however, formulations may also include fillers or additives that do not further affect the strength.

[0301] Curing may be carried out at standard ambient temperature and pressure ("SATP", 1 atmospheric pressure, 25°C), at temperatures above or below that temperature, at pressures above or below that pressure, and over time. Curing can be carried out under various heating, heating rates, and temperature profiles (e.g., holding time and temperature, continuous temperature changes, circulating temperature changes, e.g., heating, holding, cooling, reheating). The time for curing can range from a few seconds (e.g., less than about 1 second or less than 5 seconds) to less than 1 minute, several minutes, several hours or days, or potentially longer. Curing can also be carried out in any type of ambient environment, such as gas, liquid, air, water, liquid containing surfactants, inert atmosphere, N2, argon, fluid gas (e.g., sweep gas), static gas, O2 reduction, reduced pressure, high pressure, ambient pressure, controlled partial pressure, and combinations thereof, and combinations of these with other processing conditions. For high-purity materials, the furnace, packaging, handling equipment, atmosphere, and other elements of the processing equipment and process are clean and free of substances that are essentially considered impurities or contaminants in the cured product. In embodiments, the curing environment, such as the furnace, atmosphere, packaging, and combinations thereof, may include materials that influence the preform, ceramic, and product, for example, the composition, catalyst, stoichiometry, properties, and performance, and combinations thereof.

[0302] Preferably, in embodiments of the curing process, curing is carried out at temperatures in the range of approximately 5°C or higher, approximately 20°C to approximately 250°C, approximately 20°C to approximately 150°C, approximately 75°C to approximately 125°C, and approximately 80°C to approximately 90°C. Higher and lower temperatures and various heating profiles (e.g., temperature changes over time ("heating rate" (e.g., temperature increase / time), holding time, and temperature)) can be utilized.

[0303] Curing conditions, such as temperature, time, and heating rate, can be predetermined, partially or entirely, depending on, for example, the size of the preform, the shape of the preform, mold retention to prevent stress cracking, off-gassing, and other phenomena associated with the curing process, or, in some embodiments, to suit the formulation. Furthermore, curing conditions are utilized in a preferably restrained manner to address any issues previously considered to be associated with the curing process. Degassing can be used, for example, to form foamed materials with open or closed structures. Similarly, curing conditions can be used to create or control the microstructure and nanostructure of the material. In general, curing conditions can be used to influence, control, or modify the process dynamics and thermodynamics (which can affect morphology, performance, characteristics, and function).

[0304] When a polysilocarb precursor formulation is cured, a crosslinking reaction occurs, and in some embodiments, provides a crosslinked structure of -Ri-Si-CC-Si-O-Si-CC-Si-R2-, where Ri and R2 vary depending on or based on the precursor used in the formulation. Embodiments of the cured product may have a crosslinked structure having silicon centers that are 3-coordinated with another silicon atom separated by fewer than 5 atoms between silicon atoms.

[0305] During the curing process, some formulations exhibit exothermic reactions (i.e., auto-heating reactions), which can generate a small amount of heat to assist or accelerate the curing reaction. Alternatively, it can generate a large amount of heat that needs to be controlled and removed to avoid problems (e.g., pressure failure). Typically, off-gassing during curing involves material loss, generally defined by the amount of remaining material, for example, by the curing yield. In the formulations of the embodiments of the present invention, the curing conditions and embodiments of the polysilocarb precursor formulations have curing yields of at least about 90%, about 92%, and about 100%. In fact, in curing in air, the material may exhibit a curing yield of over 100% (e.g., about 101-105%) as a result of oxygen absorbed from the atmosphere. Furthermore, during curing, the material typically shrinks. This shrinkage varies depending on the composition, curing conditions, and properties of the preform shape, as well as whether the preform is reinforced, filled, neat, or unreinforced, and can range from about 20% to less than 20%, less than about 15%, less than about 5%, less than about 1%, less than about 0.5%, less than about 0.25%, and less.

[0306] Preform curing can be carried out by any type of heating device, mechanism, technology, or morphology with the necessary level of temperature and environmental control, such as heated water baths, electric furnaces, microwave furnaces, gas furnaces, furnaces, forced-heated air, towers, spray drying, flow-through thin-film reactors, fluidized bed reactors, lasers, indirect heating elements, direct heating, infrared heating, UV irradiation, RF furnaces, in-situ emulsification by high-shear mixing, and in-situ emulsification by ultrasonic treatment.

[0307] A cured preform, whether unreinforced, neat, filled, or reinforced, can be a standalone product, a final product, a finished product, or a pre-product that undergoes further machining or processing. The preform can also be subjected to thermal decomposition, which converts the preform material into ceramic.

[0308] When preforms, cured structures, or cured materials are thermally decomposed, they are heated to approximately 600°C to 2,300°C, 650°C to 1,200°C, 800°C to 1,300°C, 900°C to 1,200°C, and 950°C to 1,150°C. At these temperatures, typically, all organic structures are removed or bonded with inorganic elements to form ceramics. Typically, temperatures are between approximately 650°C and 1,200°C, and the resulting material is an amorphous, glassy ceramic. When heated above approximately 1,200°C, nanocrystalline structures, or microcrystalline structures, such as SiC, Si3N4, SiCN, and β-SiC, are formed; above 1,900°C, SiC structures are formed; and above 2,200°C, αSiC is typically formed. Thermally decomposed materials, such as ceramic materials, can be single crystals, polycrystalline, amorphous, or combinations and variations thereof, and subgroups of these and other types of morphology.

[0309] Pyrolysis can be carried out under different heating and conditions, preferably including temperature control, rate control, and combinations and variations thereof. For example, pyrolysis can involve various heating rates, heating cycles, and environmental factors. In some embodiments, the temperature can be increased, held at a predetermined temperature to facilitate known transformations (e.g., gasification, volatilization, intramolecular rearrangement, etc.), and then increased to the next holding temperature. Pyrolysis can be carried out in reducing atmospheres, oxidizing atmospheres, low O2, gas-rich (e.g., inside or very close to a flame), inert, N2, argon, air, reduced pressure, atmospheric pressure, pressurized, fluid gas (e.g., sweep gas, e.g., from about 15.0 GHSV to about 0.1 GHSV, and from about 6.3 GHSV to about 3.1 GHSV, with a flow rate of about 3.9 GHSV), static gas, and combinations thereof.

[0310] The pyrolysis is preferably carried out for a time that results in the complete pyrolysis of the preform. For high-purity materials, the furnace, packaging, handling equipment, and other elements of the pyrolysis apparatus are clean and contain, or do not contain, any materials that are essentially considered impurities or contaminants in the pyrolyzed material. A constant flow rate of "sweep" can help purge the furnace during the generation of volatile substances. In embodiments, the pyrolysis environment (e.g., furnace, atmosphere, packaging, or combination thereof) may include materials (e.g., composition, stoichiometry, characteristics, performance, and combinations thereof) that contribute to the properties of the ceramic, end-use, or product.

[0311] During pyrolysis, some material may be lost due to gasification. The amount of material remaining after a pyrolysis step or cycle is called the carbon yield (or pyrolysis yield). The formulations of embodiments of the present invention and the polysilocarb precursor formulations can have carbon yields for SiOC formation of at least about 60%, about 70%, about 80%, and at least about 90%, and at least about 91% or more. In fact, in pyrolysis in air, the carbon yield is 91% or more, and it can approach 100%. Specially formulated formulations can be used to avoid material degradation due to pyrolysis in air (typically, pyrolysis in an inert atmosphere, a reduced oxygen atmosphere, an essentially inert atmosphere, a minimal oxygen atmosphere, and combinations thereof). For example, formulations with a high phenyl content (at least about 11% by weight of phenyl, preferably about 20% by weight) and formulations with a high allyl content (at least about 15% to about 60%) can be used to mitigate material degradation in pyrolysis in air.

[0312] In some embodiments, the initial or first pyrolysis step for SiOC formation generally yields a structure that is not very dense, for example, does not reach the density required for the intended application. However, in some examples, such as when using lightweight spheres, propants, dyes, etc., the first pyrolysis is typically sufficient. Therefore, a re-infiltration process is generally performed on the pyrolyzed material to fill or occupy spaces and gaps in the structure, in addition to the polysilocarb precursor formulation material. This re-infiltrated material may then be cured and re-pyrolyzed. In some embodiments, the re-infiltrated material is cured but not pyrolyzed. In this pyrolysis process, re-infiltration is repeated 1, 2, 3, 10 and more times to obtain the desired density of the final product.

[0313] In some embodiments, during thermal decomposition, graphenic, amorphous carbon graphite structures, and combinations and variations thereof are present in Si-OC ceramics. SiO4, SiO3C, SiO2C2, SiOC3, and SiC4 are reduced to SiO x C y The distribution of silicon species in the structure is formed by varying ratios resulting from precursor selection and their processing history. Carbon generally bonds with neighboring carbon and / or silicon atoms. Generally, in the ceramic state, most carbon does not coordinate with oxygen atoms, and therefore most oxygen coordinates with silicon.

[0314] Pyrolysis can be carried out in any heating apparatus capable of maintaining the required temperature and environment. For example, pyrolysis can therefore be carried out in apparatuses and systems such as gas furnaces, electric furnaces, direct heating, indirect heating, fluidized beds, kilns, tunnel kilns, box kilns, shuttle kilns, coking type apparatuses, lasers, microwaves, and combinations and variations thereof, which can achieve the temperature required for pyrolysis.

[0315] Custom and predefined controls of chemical reactions, sequencing, and rearrangement at various stages of the process, from raw materials to the final product, can provide a combination and variation of reduced costs, increased process control, increased reliability, enhanced efficiency, improved product properties, increased purity, and other benefits. Sequencing of these transformations can be based on the treatment or shaping of precursors and precursor formulations; and further, on curing and thermal decomposition conditions. Furthermore, custom and predefined selections of these steps, formulations, and conditions can provide enhanced product and processing properties through various transformations, such as chemical reactions; molecular sequencing and rearrangement; and microstructural sequencing and rearrangement.

[0316] At various points in the manufacturing process, polymer-derived ceramic structures (e.g., polysilocarb structures, intermediates, final products, and combinations thereof, variations thereof) can be machined, crushed, molded, shaped, drilled, etched, or otherwise mechanically processed and formed.

[0317] Starting materials, precursor formulations, polysilocarb precursor formulations, and methods for compounding, manufacturing, forming, curing and pyrolysis, polymer-derived materials, structures, and precursor materials for forming ceramics are described in published U.S. Patent Publication Nos. 2014 / 0274658, 2014 / 0343220, 2014 / 0326453, and 2015 / 0175750, and U.S. Patent Application Nos. 62 / 106,094, and 62 / 193,046, the full disclosures of which are referenced and incorporated herein.

[0318] Preferred SiC-derived SiC curing and thermal decomposition Preferably in the production of SiC and the materials used in the production of SiC, in a preferred embodiment, the polysilocarb precursor can be mixed in clean air at about 1 atmosphere of pressure.

[0319] Preferably, in the production of SiC and the materials used in the production of SiC, curing occurs at temperatures ranging from about 20°C to about 150°C, from about 75°C to about 125°C, and from about 80°C to about 90°C. Curing is carried out for a time that preferably reduces to a hard cured product. Curing occurs in air or an inert atmosphere, and preferably in an argon atmosphere at atmospheric pressure. Most preferably, for high-purity materials, the furnace, packaging container, handling equipment and other elements of other curing equipment are clean and free of all elements or materials that are essentially considered impurities or contaminants in the cured product.

[0320] Preferably, in SiC production and in materials used in SiC production, pyrolysis occurs at temperatures ranging from about 800°C to about 1300°C, about 900°C to about 1200°C, and about 950°C to 1150°C. Pyrolysis is preferably carried out for a time that reduces to the complete pyrolysis of the preform. Preferably, pyrolysis is carried out under atmospheric pressure in an inert gas (e.g., argon), and more preferably in a flowing argon gas. The gas can flow at about 1,200 cc / min to about 200 cc / min, about 800 cc / min to about 400 cc / min, and about 500 cc / min. Preferably, the processing furnace is initially vacuum-evacuated to a pressure of at least 1E-3 Torre or less and repressurized to 100 Torre or more with an inert gas (e.g., argon). More preferably, vacuum evacuation is reduced to 1E-5 Torre or less before repressurizing with an inert gas. The vacuum evacuation process can be completed from zero to >4 times before processing. Most preferably, for high-purity materials, the furnace, packaging container, handling equipment, and other elements of the curing apparatus are clean and free of all elements or materials that are essentially considered impurities or contaminants in the cured product.

[0321] In the embodiment, the required low levels of N and O are achieved by vacuum, preferably by using a turbopump, to 10E-6 Torr, and then the furnace is filled with an inert gas. This purging process can be performed once or multiple times to achieve the low levels. A constant flow rate of gas "sweeping" can help purge the furnace during the generation of volatile substances.

[0322] Preferably, when producing SiC, the ceramic SiOC is converted to SiC, and then, or continuously, a thermal decomposition or conversion step is carried out. The conversion step from SiOC can be part of the thermal decomposition of the SiOC preform, for example, continuous, or it can be carried out at completely separate times and places or both. Depending on the desired type of SiC, the conversion step can be carried out at temperatures from about 1,200°C to about 2,550°C and from about 1,300°C to 1,700°C. Generally, at temperatures from about 1,600°C to 1,900°C, the formation of the beta type is favorable. At temperatures above 1,900°C, the formation of the alpha type is favorable. Preferably, the conversion occurs in an inert gas (e.g., argon), and more preferably in a flowing argon gas, at or near atmospheric pressure. The gas can flow at speeds from about 600 cc / min to about 10 cc / min, from about 300 cc / min to about 50 cc / min, and from about 80 cc / min to about 40 cc / min. Most preferably, for high-purity materials, the furnace, packaging container, handling equipment, and other elements of the curing apparatus are clean and free of all elements or materials that are essentially considered impurities or contaminants in the cured product.

[0323] The yield of SiC derived from SiOC is generally around 10% to 50%, typically 30% to 40%, but can be higher or lower.

[0324] Most preferably, when producing high-purity SiC, the manufacturing, curing, thermal decomposition, and activation of the material are carried out under cleanroom conditions, for example, under the ISO 14644-1 cleanroom standard of at least ISO 5, at least ISO 4, at least ISO 3, at least ISO 2, and at least ISO 1. In embodiments, the material handling steps are carried out in a cleanroom of at least ISO 5, but a lower cleanliness of ISO > 5 is used for the thermal decomposition and conversion steps.

[0325] The following examples are provided to illustrate various embodiments of the invention, including other precursor formulations, processes, methods, apparatus, articles, compositions, and uses. These examples are for illustrative purposes only and do not limit the scope of the invention. Percentages used in the examples are weight percentages of the total batch, preform, or structure unless otherwise noted. [Examples]

[0326] Example 1 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 41% MHF and 59% TV together at room temperature. This precursor formulation contains 0.68 moles of hydride, 0.68 moles of vinyl, and 1.37 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0327] [Table 5]

[0328] Calculations show that the OSiOC derived from this formulation contains 1.37 moles of C after all CO has been removed, and includes 0% excess C.

[0329] Example 2 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 90% methyl-terminated phenylethyl polysiloxane (containing 27% X) with 10% TV at room temperature. This precursor formulation contains 1.05 moles of hydride, 0.38 moles of vinyl, 0.26 moles of phenyl, and 1.17 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0330] [Table 6]

[0331] Calculations show that the OSiOC derived from this formulation contains 2.31 moles of C after all CO has been removed, and includes 98% excess C.

[0332] Example 3 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 70% methyl-terminated phenylethyl polysiloxane (containing 14% X) and 30% TV at room temperature. This precursor formulation contains 0.93 moles of hydride, 0.48 moles of vinyl, 0.13 moles of phenyl, and 1.28 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0333] [Table 7]

[0334] Calculations show that the OSiOC derived from this formulation contains 1.77 moles of C after all CO has been removed, and includes 38% excess C.

[0335] Example 4 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 50% methyl-terminated phenylethyl polysiloxane (containing 20% ​​X) and 50% TV together at room temperature. This precursor formulation contains 0.67 moles of hydride, 0.68 moles of vinyl, 0.10 moles of phenyl, and 1.25 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0336] [Table 8]

[0337] Calculations show that the OSiOC derived from this formulation contains 1.93 moles of C after all CO has been removed, and includes 55% excess C.

[0338] Example 5 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 65% methyl-terminated phenylethyl polysiloxane (containing 40% X) and 35% TV at room temperature. This precursor formulation contains 0.65 moles of hydride, 0.66 moles of vinyl, 0.25 moles of phenyl, and 1.06 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0339] [Table 9]

[0340] Calculations show that the OSiOC derived from this formulation contains 2.81 moles of C after all CO has been removed, and includes 166% excess C.

[0341] Example 6 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 65% MHF and 35% dicyclopentadiene (DCPD) together at room temperature. This precursor formulation contains 1.08 moles of hydride, 0.53 moles of vinyl, 0.0 mole of phenyl, and 1.08 moles of methyl. Based on 100 g of the formulation, the precursor formulation contains the following molar amounts of Si, C, and O.

[0342] [Table 10]

[0343] Calculations show that the SiOC derived from this formulation contains 2.65 moles of C after all CO has been removed, and includes 144% excess C.

[0344] Example 7 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 82% MHF and 18% dicyclopentadiene (DCPD) together at room temperature. This precursor formulation contains 1.37 moles of hydride, 0.27 moles of vinyl, 0.0 mole of phenyl, and 1.37 moles of methyl. Based on 100 g of the formulation, the precursor formulation contains the following molar amounts of Si, C, and O.

[0345] Calculations show that the OSiOC derived from this formulation contains 1.37 moles of C after all CO has been removed, and includes 0% excess C.

[0346] [Table 11]

[0347] Example 8 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 46% MHF, 34% TV, and 20% VT together at room temperature. This precursor formulation contains 0.77 moles of hydride, 0.40 moles of vinyl, 0.0 mole of phenyl, and 1.43 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0348] [Table 12]

[0349] Calculations show that the OSiOC derived from this formulation contains 0.53 moles of C after all CO has been removed, resulting in a 63% C deficiency or 63% C shortage.

[0350] Example 9 The preparation of the polysilocarb formulation using the mixed-type method is made by mixing 70% MHF, 20% TV, and 10% VT together at room temperature. This precursor formulation contains 1.17 moles of hydride, 0.23 moles of vinyl, 0.0 mole of phenyl, and 1.53 moles of methyl. The precursor formulation contains the following molar amounts of Si, C, and O based on 100 g of the formulation.

[0351] [Table 13]

[0352] Calculations show that the OSiOC derived from this formulation contains 0.33 moles of C after all CO has been removed, resulting in a 78% C deficiency or 78% C shortage.

[0353] Example 10 The preparation of polysilocarb formulations using the mixed-type method is made by mixing 95% MHF and 5% TV at room temperature.

[0354] Example 11 The preparation of polysilocarb formulations using the mixed-type method is made by mixing 50% methyl-terminated phenylethyl polysiloxane (containing 20% ​​X), 50% TV, and 95% MHF at room temperature.

[0355] Example 12 The preparation of polysilocarb formulations using the mixed-type method is made by mixing 54% methyl-terminated phenylethyl polysiloxane (containing 25% X) and 46% TV together at room temperature.

[0356] Example 13 The preparation of polysilocarb formulations using the mixed-type method is made by mixing 57% methyl-terminated phenylethyl polysiloxane (containing 30% X) and 43% TV together at room temperature.

[0357] Example 14 Approximately 100 grams of polysilocarb compound is prepared. The compound is mixed at room temperature for 15 minutes. Next, 1% of the catalyst is added, and the mixture is stirred for a further 10 minutes. The catalyst contains 10 ppm of Pt in short-chain vinyl-terminated polysiloxane.

[0358] The mixture was poured into a Teflon® (PTFE, polytetrafluoroethylene)-coated aluminum foil pan and cured in argon or air at 90°C for 2.5 hours.

[0359] The cured polymer is mechanically crushed into pieces small enough to fit into ceramic boats (e.g., crucibles 3.5 inches long, 2.5 inches wide, and 5 / 8 inch deep); and then placed inside these ceramic boats. The ceramic boats containing the cured polymer are heated in a stainless steel retort filled with argon gas flowing at 500 cc / min as follows: Heat from room temperature to 82.2°C at a heating rate of 82.2°C / hour, then hold at 82.2°C for 1 hour; Heat from 82.2°C to 182°C at a heating rate of 48.9°C / hour, then hold at 182°C for 1 hour; Heat from 182°C to 210°C at a heating rate of 48.9°C / hour, then hold at 210°C for 2 hours; The sample was heated from 210°C to 1,110°C at a heating rate of 115.6°C / hour, held at 1,110°C for 2 hours, and then cooled to 204.4°C before opening.

[0360] The pyrolyzed material is returned to its powder or lump form and placed in a graphite boat. The graphite boat is placed in an alumina metal tubular furnace, with both ends blocked by insulators and caps to allow gas inflow and exhaust gas outflow. Argon gas is flowed through the metal tubular furnace at a rate of 50 cc / min. The material is then heated to 1,650°C over 10 hours (heating rate of approximately 3°C / min) and held at this temperature for another 10 hours. The furnace is then slowly cooled to 700°C over 5 hours. The end caps are then removed when the temperature is below 300°C, and the furnace is cooled further. The resulting polysilocarb-derived SiC is recovered from the furnace.

[0361] Example 15 The polysilocarb formulation is prepared in a cleanroom environment using clean glassware to essentially remove all potential impurities, particularly Al, Fe, and B. The formulation is mixed at room temperature for approximately 10–20 minutes, then 0.25% to 2% catalyst solution is added, and the mixture is stirred for a further 10 minutes. The catalyst solution contains 10 ppm of Pt. The final catalyzed formulation contains 10–50 ppb of Pt. In a cleanroom environment, the formulation was placed in a PFA (perfluoroalkoxy polymer) bottle or jar that had been purged with argon and sealed. The formulation was cured at 75°C to 160°C for 1.5 to 4 hours.

[0362] In a cleanroom environment, the cured polymer is placed in a ceramic crucible. The filled crucible is then covered with a ceramic cap and placed in a ceramic retort filled with argon gas flowing at 500 cc / min. The crucible, furnace, and associated equipment are clean and essentially free of contaminants; in particular, they do not provide a source of Al or B. The crucible is heated from approximately 30°C to approximately 180°C / hour as follows: Heat from room temperature to 1,000°C at a heating rate of 180°C / hour, then hold at 1,000°C for 2 hours; and, The device was cooled to 204.4°C and then opened.

[0363] The pyrolyzed material is processed into a powder or mass and placed in a graphite boat. The graphite boat is placed in an alumina metal tubular furnace, with both ends blocked by insulators and caps to allow gas inflow and exhaust gas outflow. The crucible, furnace, and associated equipment are clean and essentially free of contaminants; in particular, they do not provide a source of Al, Fe, or B. Argon gas is flowed through the metal tubular furnace at a rate of 50 cc / min. The material is then heated from 1,400°C to 1,650°C over 7 to 15 hours (heating rate of approximately 3°C / min) and held at this temperature for a further 10 hours. The furnace is then slowly cooled to 700°C over 5 hours. The furnace is further cooled, and the end caps are removed when the temperature is below 300°C. The resulting polysilocarb-derived SiC is recovered from the furnace.

[0364] Example 15a The process in Example 15 is carried out using a vacuum-ready graphite furnace with a cleaned graphite insulator and ports that allow gas inflow and exhaust gas outflow / vacuum evacuation. Argon gas is then flowed into the graphite furnace at a rate of 1 to 6 volume exchanges per hour in the hot zone. The material is then heated from 25°C to 2100°C. This process can produce SiC with a purity of 6 nines or higher.

[0365] Example 15b In processes similar to those in Examples 15 and 15a, cooling, heating, and both during pyrolysis and conversion can be from about 1°C / min to about 30°C / min, from about 3°C / min to about 20°C / min, from about 10°C / min to about 20°C / min, and slower or faster, as well as various combinations of rates, e.g., 1 hour at about 5°C / min and 3 hours at about 10°C / min. Holding times at specific high temperatures can be from about 0.25 hours to about 24 hours, from about 1 hour to about 12 hours, from about 3 hours to about 8 hours, less than 24 hours, less than 12 hours, less than 8 hours, and longer or shorter times may also be used. Similarly, combinations and variations of holding times in specific heating cycles can also be used.

[0366] Example 16 The polysilocarb formulation is produced in a cleanroom environment using glassware that has been cleaned to remove all potential impurities. The formulation is mixed at room temperature until it is uniformly combined. Next, the catalyst is added, and the mixture is further stirred to disperse the catalyst. The polysilocarb formulation is then processed into high-purity SiC in a continuous process as follows:

[0367] In a cleanroom environment, the compound is placed in a graphite container and cured into a hard, cured material. Without removing the cured material from the furnace, it is converted to SiOC, and then to SiC. During these heating processes, an inert, non-reactive gas is passed through the furnace, and the cured polymer is placed in a ceramic crucible. (Although N2 is sometimes accepted as an inert, in the molding of high-purity SiOC and SiC, it is preferably avoided during the heating of thermal decomposition or conversion because nitrogen can react with Si to form nitride-containing species, such as silicon oxynitride, silicon nitride, and silicon carbonitride.) The resulting polysilocarb-derived SiC is recovered from the furnace.

[0368] Example 17 Refer to Figure 5. Flow diagrams of embodiments of systems and methods for producing SiC derived from SiOC and for producing materials of lower and more preferably higher purity (e.g., 3 nines, 4 nines, 5 nines, even more preferably 6 nines, or higher) are provided. Lines, valves, and inner surfaces of the system containing the precursor and other materials are made from or coated with materials that do not contaminate the SiOC and the derived SiC, for example, materials that do not contain sources of impurities. Storage tanks 150a and 150b hold liquid polysilocarb precursor. In this embodiment, the precursor passes through a distillation apparatus 151a and a distillation apparatus 151b to remove all impurities from the liquid precursor. The liquid precursor is then transferred to a mixing vessel 152, where it is mixed to form a precursor batch and catalyzed. In a clean room environment 157a, the precursor batch is packaged in a container 153 for placement in a furnace 154. The furnace 154 has a sweep gas inlet 161 and an off-gas outlet 162. The packaged and cured material is then transferred under cleanroom conditions to several pyrolysis furnaces 155a, 155b, and 155c, where it is converted from SiOC to SiC. The furnaces have sweep gas inlet lines 158a, 158b, and 158c, and two off-gas outlet lines 159a, 160a, 159b, 160b, 169c, and 160c. The resulting SiC-derived SiC is then packaged 156 in a cleanroom environment 157b for shipment or use in other processes. The off-gas is treated and cleaned, and the starting material is recovered in an off-gas treatment device 163, which has an inlet line 164 for collecting off-gas from various units in the system.

[0369] Example 18 The SiC produced by the process in Example 16 has a purity of 99.999 and has the X-ray diffraction spectrum shown in Figure 6. Based on position [°2 theta] (copper), area 601 of the spectrum corresponds to 7.551[°]; 2.496[°], area 602 corresponds to 16.737[°]; 3.994[°], area 603 corresponds to 35.644[°]; SiC; 1.498[°], area 604 corresponds to 41.357[°]; SiC; 1.498[°], area 605 corresponds to 59.977[°]; SiC; 1.498[°], and area 606 corresponds to 71. Equivalent to 730[°]; SiC; 1.498[°], area 607 of the spectrum corresponds to 75.461[°]; SiC; 1.498[°], area 608 of the spectrum corresponds to 89.958[°]; SiC; 1.498[°], area 609 of the spectrum corresponds to 100.722[°]; SiC; 1.498[°], area 610 of the spectrum corresponds to 104.874[°]; SiC; 1.997[°], and area 611 of the spectrum corresponds to 119.903[°]; SiC; 1.498[°].

[0370] Example 19 A polysilocarb formulation containing 40% MHF and 60% TV was mixed with 2% Pt catalyst. The catalyzed formulation contained 97.4 ppb (parts per billion) of Al, 108.6 ppb of Fe, 214 ppb of B, an unmeasurable amount of P, and 96 ppb of Pt. The catalyzed formulation was poured into a graphite container containing an aluminum tube with a graphite interior, which was placed in a metal tubular furnace. The furnace was heated at a rate of 3°C / min until the temperature reached 1675°C and held for 10 hours. Argon was flowed through the furnace throughout the heat treatment. The obtained SiC had a purity of 3 nines (i.e., 99.9% purity) and contained the following impurities (ppm): Al 9.8, Fe 3.4, B 4.1, P 0.97, Pt 30, Ca 70, Mg 70, Li 53, Na 26, Ni 1.5, V 0.3, Pr 0.35, Ce 0.08, Cr 0.67, S 0.18, As 0.5.

[0371] Example 20 The SiC material with a purity of 3 nines in Example 19 is soaked in an acid cleaning agent (10% HNO3 + 5% HCl solution) and then rinsed with deionized water. The washed SiC has a purity of 5 nines.

[0372] Example 21 The process in Example 19 was carried out under cleanroom conditions and protocols. The alumina furnace tube was replaced with a ceramic furnace. B, Fe, and P were removed from the starting materials (i.e., MHF and TV) by ion exchange resin (e.g., Amberlite IRA743), stripped, or distilled. The purity of the resulting silicon carbide was 5 nines.

[0373] Example 22 The SiC material in Example 21 is washed and rinsed. The purity of the cleaned material is 6 nines.

[0374] Example 23 The starting material initially contains 500 ppb (parts per billion) of Al, 5,000 ppb of Fe, 500 ppb of B, and 1,700 ppb of P. Using cleanroom conditions and protocols in this example, the starting material is purified by filtration. A polysilocarb compound having 40% MHF and 60% TV is made from the purified starting material, mixed, and a 0.25% Pt catalyst solution is added. The catalyzed compound contains less than approximately 50 ppb of Al, less than approximately 50 ppb of Fe, less than approximately 50 ppb of B, less than approximately 50 ppb of P, and about 96 ppb of Pt. The catalyzed compound is poured into a graphite container and placed in a furnace having a ceramic interior. A shield is placed in the furnace to separate the heating element from the graphite container, at least partially. The furnace is heated at a rate of 2.5°C / min until the temperature reaches 1700°C, and the temperature is maintained for 12 hours. Argon is flowed through the furnace throughout the entire heat treatment. The resulting SiC has a purity of 5 nines and contains the following impurities (ppm): Al 2.1, Fe 0.58, B 0.24, P 0.97, Pt 0.41, Ca < 0.5, Mg < 0.05, Li < 0.01, Na 0.09, Ni 1.5, V < 0.01, Pr < 0.05, Ce < 0.05, Cr < 0.1, S < 0.1, As < 0.5. The SiC is primarily of the beta type.

[0375] Example 24 The SiC material in Example 23 is washed and rinsed. The purity of the cleaned material is 6 nines.

[0376] Example 25 Using cleanroom conditions and protocols, a polysilocarb compound containing 40% MHF and 60% TV is prepared from purified starting materials, mixed, and 0.25% Pt catalyst is added. The catalyzed compound is poured into a graphite vessel with a ceramic interior placed in a furnace. The furnace is heated at a rate of 3°C / min until the temperature reaches 2250°C and is held for 12 hours. Argon is flowed through the furnace throughout the heat treatment. The resulting SiC has a purity of 6 nines. The SiC is of the alpha type.

[0377] Example 26 The polysilocarb formulation is produced in a cleanroom environment using glassware that has been purified to remove all potential impurities. The formulation is mixed at room temperature until uniformly combined, then the catalyst is added, and the mixture is further stirred to distribute the catalyst. The polysilocarb formulation is then processed into high-purity SiOC in a continuous process as follows:

[0378] In a cleanroom environment, the compound is placed in a graphite container and cured into a hardened material. Without removing the cured material from the furnace, it is converted to SiOC. During this heating, an inert, non-reactive gas, such as Ar, is flowed through the furnace. The resulting polysilocarb-derived SiOC is recovered from the furnace. It is washable and has a purity of approximately 99.9999 (e.g., 6 nines), with Al and B levels below 0.1 ppm. The SiOC is stored under cleanroom conditions and protocols to protect it from contamination for later use.

[0379] Example 27 The polysilocarb formulation is formed using a mixed-type method. The formulation is made by mixing 70% of an allyl-terminated polydimethylsiloxane (TV) precursor with a molecular weight of approximately 500 and 30% of an MHF precursor with a molecular weight of approximately 800 in a container, and then placing it in a storage container for later use in producing SiC and SiC. The polysilocarb formulation has a good shelf life at room temperature, and the precursors do not react with each other. The polysilocarb formulation has a viscosity of approximately 10 cps.

[0380] Example 28 The polysilocarb formulation is formed using a mixed-type method. The formulation is prepared by mixing 10% of an MHF precursor with a molecular weight of approximately 800, 73% of a methyl-terminated phenylethylpolysiloxane (containing 10% X) with a molecular weight of approximately 1000, 16% of a TV precursor, and 1% of an OH-terminated precursor silanol (hydroxy)-terminated polydimethylsiloxane with a molecular weight of approximately 1000 in a container, and then placing it in a storage container for later use in producing SiC and SiC. The polysilocarb formulation has a good shelf life at room temperature, and the precursors do not react with each other. The polysilocarb formulation has a viscosity of approximately 18 cps.

[0381] Example 29 Polysilocarb formulations are formed using a mixed-type method. The formulation is prepared by mixing 0-90% of an MH precursor with a molecular weight of approximately 800, 0-90% of a methyl-terminated phenylethylpolysiloxane (containing 10% X) with a molecular weight of approximately 1000, 0-30% of a TV precursor, 0-30% of a vinyl-terminated precursor allyl-terminated polydimethylsiloxane with a molecular weight of approximately 9400, and 0-20% of an OH-terminated precursor silanol (hydroxy)-terminated polydimethylsiloxane with a molecular weight of approximately 800 in a container, and then placing it in a storage container for later use in producing SiOC and SiC. Polysilocarb formulations have a good shelf life at room temperature, and the precursors do not react with each other. Polysilocarb formulations have a viscosity of approximately 100 cps.

[0382] Example 30 Polysilocarb formulations are formed using a mixed-type method. The formulation is prepared by mixing 20-80% of an MH precursor with a molecular weight of approximately 800, 0-10% of a TV precursor, and 5-80% of a vinyl-terminated, allyl-terminated polydimethylsiloxane in a container, and then storing it in a storage container for later use in producing SiC and SiC. The polysilocarb formulations have a good shelf life at room temperature, and the precursors do not react with each other. The polysilocarb formulations have a viscosity of approximately 300 cps.

[0383] Example 31 Using a reaction-type process, the precursor formulation was prepared using the following formulation. The reaction temperature was maintained at 61°C for 21 hours.

[0384] [Table 14]

[0385] Example 32 Using a reaction-type process, the precursor formulation was prepared using the following formulation. The reaction temperature was maintained at 72°C for 21 hours.

[0386] [Table 15]

[0387] Example 33 Using a reaction-type process, the precursor formulation was prepared using the following formulation. The reaction temperature was maintained at 61°C for 21 hours.

[0388] [Table 16]

[0389] Example 34 Using a reaction-type process, the precursor formulation was prepared using the following formulation. The reaction temperature was maintained at 61°C for 21 hours.

[0390] [Table 17]

[0391] Example 35 Using a reaction-type process, the precursor formulation was prepared using the following formulation. The reaction temperature was maintained at 61°C for 21 hours.

[0392] [Table 18]

[0393] Example 36 Refer to Figure 7. Figure 7 is a cross-sectional view of an overview of an apparatus for growing SiC crystals and crystalline structures. The deposition apparatus 700 has a container 701 to which various heating elements (e.g. 702) are provided (for example, thermally related and arranged to provide electromagnetic energy and wrapped around the container). The heating elements are configured and operated to provide at least two different temperature zones, zone A, 702a, and zone B, 702b. Inside the container 701 is a polymer-derived ceramic 703 (which is the source of Si and C). Inside the container 701 is also a crystal growth initiation article 704.

[0394] Generally, the polymer-derived ceramic 703 is heated to a temperature higher than the sublimation temperature of SiC in zone A702a, typically around 2,000°C. Subsequently, the SiC vapor rises to temperature zone B. The temperature in zone B is lower than that in zone A. The SiC vapor is deposited as SiC onto the starting article 704.

[0395] A schematic diagram of apparatus 700 is shown in a highly simplified form. Commercial and industrial apparatus may include additional elements (e.g., control systems, monitors, gas handling equipment and other devices), different structures known to those skilled in the art, as well as new apparatus and structures based in part on the disclosure herein.

[0396] Example 35a The polymer-derived ceramic 703 in the deposition apparatus 701 is high-purity SiC. The temperature in zone A is gradually increased and maintained at a set temperature that converts SiC to SiC, causing sublimation of SiC and forming SiC crystals on the starting material 704.

[0397] Example 35b In this example, the starting article 704 is a seed crystal, and the SiC deposited from the polymer-derived SiC in zone A forms an alpha monocrystalline boule. This boule is then segmented to form a polysilocarb-derived SiC wafer.

[0398] Example 35c In this example, the starting article 704 is a Si substrate, and SiC from the polymer-derived SiC in zone A is deposited on the SiC substrate as an epitaxial polysilocarb-derived SiC layer.

[0399] Example 35d In the deposition apparatus 701, the polymer-derived ceramic 703 is high-purity SiC with a purity of 6 nines. The temperature in zone A is gradually increased and maintained at a set temperature that converts SiC to SiC, causing sublimation of SiC and forming SiC crystals on the starting material 704.

[0400] Example 35e In the deposition apparatus 701, the polymer-derived ceramic 703 is high-purity SiC containing less than 20 ppm of Al. The temperature in zone A is gradually increased and maintained at a set temperature that converts SiC to SiC, causing sublimation of SiC and forming SiC crystals on the starting material 704.

[0401] Example 35f In the deposition apparatus 701, the polymer-derived ceramic 703 is SiC derived from high-purity polysilocarb containing less than 20 ppm of Al. The sublimation of SiC forms SiC crystals on the starting material 704, which serve as seed crystals.

[0402] Example 36 The deposition apparatus 701 is a hot wall reactor.

[0403] Example 37 The deposition apparatus 701 is a multi-wafer reactor.

[0404] Example 38 The vapor deposition apparatus 701 is a chimney reactor.

[0405] Example 39 A polysilocarb-derived SiC boule with a length of approximately 1 inch and a diameter of approximately 4 inches. The boule is alpha-type and has no micropipes. The boule has fewer than 100, fewer than 10, and preferably no micropores at all.

[0406] Example 39a The boules of SiC derived from polysilocarb are <10 / cm 2 <5 / cm 2 <1 / cm 2 <0.5 / cm 2 , and most preferably <0.1 / cm 2 It has a micropipe density.

[0407] Example 40 Metal-semiconductor field-effect transistors (MESFETs) are made from polysilocarb-derived SiC. These MESFETs are incorporated into compound semiconductor devices that operate in the 45 GHz frequency range.

[0408] Example 41 Metal-semiconductor field-effect transistors (MESFETs) are made from polysilocarb-derived SiC. These MESFETs are incorporated into cellular base stations.

[0409] Example 42 Boules of polysilocarb-derived SiC, approximately 2 inches in length and 4 inches in diameter. The boules are doped to form p-wafers for semiconductor equipment.

[0410] Example 43 A polysilocarb-derived SiC boule with a length of approximately 2 inches and a diameter of approximately 4 inches. The boule is doped to form n-wafers for semiconductor equipment.

[0411] Example 44 Refer to Figure 8. Figure 8 is a cross-sectional view of an overview of an apparatus for growing SiC crystals and crystalline structures. The deposition apparatus 800 has a vessel 801 equipped with a heat source 802. The heat source and the vessel and heat source can be any configuration described herein or known. The heat source is configured and operated to provide at least two different temperature zones, zone A 802a and zone B 802b. Inside the vessel 801 is a polymer-derived ceramic 803, which is a source of Si and C. The polymer-derived ceramic 803 is the polysilocarb of Example 6, which has been cured and converted to SiC according to Example 14. Inside the vessel 801 is further a crystal growth initiation article 804.

[0412] Therefore, generally, the polymer-derived ceramic 803 is heated in zone A802a to a temperature higher than the sublimation temperature of SiC, generally around 2,400°C. Subsequently, the SiC vapor rises to temperature zone B, where the temperature is lower than that of zone A. The SiC vapor is deposited onto the starting article 804 as SiC.

[0413] A schematic diagram of apparatus 800 is shown in a highly simplified form. Commercial and industrial apparatus may include additional elements (e.g., control systems, monitors, gas handling equipment and other devices), different structures known to those skilled in the art, as well as new apparatus and structures based in part on the disclosure herein.

[0414] Example 45 Refer to Figure 9. Figure 9 is a cross-sectional view of an overview of an apparatus for growing SiC crystals and crystalline structures. The deposition apparatus 900 has a vessel 901 equipped with a heat source 902. The heat source and the vessel and heat source can be any configuration described herein or known. The heat source is configured and operated to provide at least two different temperature zones, zone A902a and zone B902b. Inside the vessel 901 is a polymer-derived ceramic 903, which is a source of Si and C. The polymer-derived ceramic 903 is the polysilocarb of Example 7, which has been cured and converted to SiC according to Example 15. Inside the vessel 901 is further a crystal growth initiation article 904.

[0415] Therefore, generally, the polymer-derived ceramic 903 is heated in zone A902a to a temperature higher than the sublimation temperature of SiC, generally around 2,500°C. Subsequently, the SiC vapor rises to temperature zone B, which is lower than zone A. The SiC vapor is deposited as SiC onto the starting article 904.

[0416] A schematic diagram of apparatus 900 is shown in a highly simplified form. Commercial and industrial apparatus may include additional elements (e.g., control systems, monitors, gas handling equipment and other devices), different structures known to those skilled in the art, as well as new apparatus and structures partially based on the disclosure herein.

[0417] Example 46 It is theorized that the excess or added carbon in polysilocarb-derived SiC material acts as a sintering aid. SiC derived from polysilocarb has a purity of 7 nines and contains approximately 0.05% to 0.5% excess carbon, forming small particulate matter of about 1 μm. These particulate materials are then sintered together to form SiC articles. No additional sintering aid is required to form solid SiC articles. These "carbon-sintered" articles are inherently stronger than similar articles made using conventional sintering aids.

[0418] Example 46a SiC derived from polysilocarb has a purity of 7 nines and is formed into small particulate matter of approximately 0.1 μm. These particulate materials are then sintered together to form SiC articles. No additional sintering aids are required to form solid SiC articles. These "self-sintered" articles are inherently stronger than similar articles made using conventional sintering aids.

[0419] Example 47 SiC derived from high-purity polysilocarb is formed into small particulate matter. The particle size is small enough not to affect a predetermined wavelength or wavelength range of light. The SiC particulate matter is sintered together to form an optical element (which is transparent to a predetermined wavelength).

[0420] Example 48 Polysilocarb-derived SiC blocks are porous. Polysilocarb material blocks are intended for use in vapor deposition equipment.

[0421] Example 49 SiC particles derived from polysilocarb, which essentially lack an oxide film on their surface.

[0422] Example 50 A polysilocarb-derived SiC high-temperature field-effect gas sensor with a SiC semiconductor having a bandgap of approximately 3.2 eV. This sensor can operate at high temperatures of 1000°C.

[0423] Example 51 Polysilocarb-derived SiCGTO (gate turn-off thyristor) is an element of a three-phase DC-AC inverter. This device can provide a forward blocking voltage of approximately 1,200 V and a controllable density of 500 A / cm².

[0424] Example 52 SiC particulate matter derived from polysilocarb having an average diameter of less than 0.25 μm (and preferably about 0.1 μm and smaller) essentially has no oxide film on its surface. These SiC particles are easily pressable SiC particulate matter (RTP), and for example, they can be sintered into volumetric shapes with minimal use of sintering aids, preferably without the need for sintering aids. This "self-sintered" SiC article is essentially stronger than similar SiC articles made using sintering aids.

[0425] Example 52a The SiC particulate material of Example 52, which is of high purity derived from polysilocarb and has a purity of at least 5 nines, is sintered to form a SiC optic.

[0426] Example 52b The high-purity SiC particulate material derived from polysilocarb, having a purity of at least 3 nines, is sintered to form a SiC wafer in Example 52.

[0427] Example 52c The SiC particulate material of Example 52, which is of high purity derived from polysilocarb and has a purity of at least 7 nines, is sintered to form a SiC wafer, preferably without the use of sintering aids.

[0428] Example 53 The precursor formulation was prepared by polymerization of 20 g of tetravinyltetramethylcyclotetrasiloxane using 0.5% of a Luperox231 peroxide catalyst. The formulation was cured at 115°C for 60 minutes. The cured polymer was converted to SiC at 1675°C. The final density was measured at 3.2 g / cc.

[0429] Example 54 200 g of tetravinyltetramethylcyclotetrasiloxane was purified by distillation prior to use. Using 20 g of the distilled tetravinyltetramethylcyclotetrasiloxane, a precursor formulation was prepared by catalysis with 0.5% Luperox 231. This formulation was cured at 115°C for 60 minutes. The cured polymer was converted to SiC at 1675°C. The final density was measured at 3.2 g / cc.

[0430] Example 55 The precursor formulation was prepared using 2 g of MH and 18 g of TV. 0.5% of Luperox 231 and 2 ppm of Pt catalyst were added. The formulation was cured at 115°C for 60 minutes. The cured polymer was converted to SiC at 1675°C. The final density was measured at 3.2 g / cc.

[0431] Example 56 The precursor formulation was prepared using a 99% MH and 1% Pt catalyst solution (10 ppm). The formulation was cured at 115°C for 60 minutes and then thermally decomposed at 1000°C for 2 hours.

[0432] Example 57 A peroxide catalyst was added to the polysilocarb formulation of Example-31, and these catalyzed formulations were dropped (droplets of the formulation were dropped) into a 50-120°C water bath to cure the formulations. The time in the water bath was approximately 1-2 minutes. Subsequently, the cured droplet structures were thermally decomposed at 950°C for approximately 60 minutes. The thermally decomposed structures were hollow spheres with a density of less than approximately 1 g / cc, a diameter of approximately 60 microns to approximately 2 mm, and a crush strength of approximately 0.5-2 ksi. These hollow spheres were then crushed to a size of less than 1 micron.

[0433] Example 58 A 10 ppm platinum catalyst is added to each of the polysilocarb batches of Examples 4-10. These catalyzed batches are dropped onto trays to form droplets and cured in an air furnace at approximately 125°C for approximately 30 minutes. The cured droplet structures were slightly non-spherical beads with a density of approximately 1.1-1.7 g / cc, a diameter of approximately 200 microns to approximately 2 mm, and a crush strength of approximately 3-7 ksi.

[0434] Example 59 A peroxide-catalyzed polysilocarb batch is added to a water bath at 50-95°C under strong stirring and preferably in the presence of a surfactant. It is more preferable that it does not contain impurities. Subsequently, the green-cured submicron beads (e.g., <1 μm) formed in the water bath are recovered from the water bath. The green-cured beads are then cured, thermally decomposed, and converted to SiC.

[0435] Example 60 A peroxide-catalyzed polysilocarb batch is added to a water bath at 50-95°C under strong stirring and preferably in the presence of a surfactant. It is more preferable that it does not contain impurities. The green-cured beads formed in the water bath are then recovered from the water bath. The green-cured beads may then be recovered from the water or retained in the water for later use, e.g., conversion to SiC.

[0436] Example 61 Polysilocarb batches from Examples 1-13, catalyzed with peroxides, are added to a water bath at 80°C under strong stirring and preferably in the presence of a surfactant. It is more preferable that it does not contain impurities. The green-cured 2 μm beads formed in the water bath were then collected from the water bath. The green-cured beads are cured and thermally decomposed.

[0437] Example 62 A batch of polysilocarb from Examples 1-13, catalyzed with platinum, was added to a water bath at 100°C under stirring. The green-cured 2 mm beads formed in the water bath were then collected from the bath. The green-cured beads were cured and thermally decomposed to convert them to SiC.

[0438] Example 63 A peroxide-catalyzed polysilocarb batch is added to a water bath at 50-95°C under strong stirring and preferably in the presence of a surfactant. It is more preferable that it does not contain impurities. The green-cured 5 μm beads (e.g., <1) formed in the water bath are then recovered from the water bath. The green-cured beads are cured and thermally decomposed to convert them to SiC.

[0439] Example 64 A peroxide-catalyzed polysilocarb batch is added to a water bath at 95°C under strong stirring and preferably in the presence of a surfactant. It is more preferable that it does not contain impurities. The green-cured beads formed in the water bath are then recovered from the water bath. The green-cured beads may then be recovered from the water or retained in the water for later use, e.g., conversion to SiC.

[0440] Example 65 Polysilocarb batches from Examples 1-13, catalyzed with peroxide, are added to a water bath at 80°C under strong stirring and preferably in the presence of a surfactant. It is more preferable that it does not contain impurities. The green-cured 2 μm beads formed in the water bath are then recovered from the water bath. The green-cured beads are cured and thermally decomposed to convert them to SiC.

[0441] Example 66 A batch of polysilocarb from Examples 1-13, catalyzed with platinum, was added to a water bath at 100°C under stirring. The green-cured 2 mm beads formed in the water bath were then collected from the bath. The green-cured beads were cured and thermally decomposed to convert them to SiC.

[0442] Example 67 SiC particulate matter derived from polysilocarb, having an average diameter of approximately 0.4 μm, essentially lacks an oxide film on its surface. Easily pressable SiC particulate matter (RTP), for example, can be sintered into volumetric shapes with minimal use of sintering aids, preferably without the need for sintering aids.

[0443] Example 68 SiC particulate matter derived from polysilocarb, having an average diameter of approximately 0.6 μm, essentially lacks an oxide film on its surface. Easily pressable SiC particulate matter (RTP), for example, can be sintered into volumetric shapes with minimal use of sintering aids, preferably without the need for sintering aids.

[0444] Example 69 SiC particulate matter derived from polysilocarb, having an average diameter of approximately 0.4 to 0.6 μm, essentially lacks an oxide film on its surface. Easily pressable SiC particulate matter (RTP), for example, can be sintered into volumetric shapes with minimal use of sintering aids, preferably without the need for sintering aids.

[0445] Example 70 The shield against blast and impact is formed using one or more layers of high-purity polysilocarb silicon carbide sintered into a sheet material. The layers of polysilocarb-derived silicon carbide sheets are bonded to a substrate. The layers are reinforced, and various weaves can be formed between the layers. The composite layer structure provides protection from blast, projectile, and explosion. While providing equal or better protection, this shield is lighter than conventional shields and armor.

[0446] Example 71 The shield against blast and impact is formed using one or more layers of high-purity polysilocarb silicon carbide sintered into a sheet material. This high-purity polysilocarb silicon carbide has a purity of 6 nines, is oxygen-free, and its 0.1-micron particles are sintered into the sheet material without the need for sintering aids. Polysilocarb-derived silicon carbide sheets are used as elements of shielding against blast and impact. It can be used in personal bulletproof clothing and automotive armor.

[0447] Example 72 The bulletproof composite structure has 12 layers of 1200 g / m² glass fiber, 20 layers formed from 5 sections of carbon fiber unidirectionally oriented at 0, 45, -45, and 90 degrees, and one layer of silicon carbide derived from polysilocarb as a surface sheet. The glass fibers can be bonded together using a polysilocarb batch by hot pressing at 150-160°C for 1-2 hours at a minimum pressure of 500 psi to form a glass fiber plate. The 20 layers of carbon fiber cloth can be bonded together under the same conditions to form a carbon fiber plate. The glass fiber plate, carbon fiber plate, and polysilocarb silicon carbide-derived sheet can be bonded in one step using a polysilocarb batch as a binder between the silicon carbide sheet and the carbon fiber plate, and between the carbon fiber plate and the glass fiber plate.

[0448] Example 73 The ultra-high purity SiOC formulations provided herein, having a purity of at least 5 nines, preferably 6 nines, are used to produce clear SiOC articles in the process disclosed and taught in U.S. Patent 5,180,694. All descriptions of the aforementioned patent are incorporated herein by reference.

[0449] Example 74 The ultra-high purity SiOC formulations provided herein, having a purity of at least 5 nines, preferably 6 nines, are used to create SiOC layers and coatings in the processes disclosed and taught in U.S. Patent 8,981,564.

[0450] Example 75 The ultra-high purity SiOC formulations provided herein, having a purity of at least 5 nines, preferably 6 nines, are used to create SiOC layers and coatings in the processes disclosed and taught in U.S. Patent 8,778,814.

[0451] It should be noted that there is no requirement to provide a basis for theories that would provide novel and innovative processes, materials, performances, or other beneficial features and properties of embodiments of the present invention. However, various theories are provided herein to further advance the art in this area. These theories presented herein, unless expressly stated otherwise, do not limit, restrict, or narrow the scope of protection granted to the inventions described in the claims. These theories are not necessary for or to be implemented in order to utilize the present invention. It should be further understood that the present invention may be linked to new and unknown theories in order to describe the functional-features of embodiments of the methods, articles, materials, apparatus, and systems of the present invention; and theories developed in the future shall not limit the scope of protection granted to the present invention.

[0452] The various embodiments of formulations, batches, materials, compositions, apparatus, systems, devices, operations, and methods described herein can be used in various fields in which SiC and Si are applicable, and similarly in fields in which SiC, Si, and neither are applicable (for cost, performance, or both). Furthermore, these various embodiments described herein may be used in various combinations. Thus, for example, the structures provided in the various embodiments herein may be used together; and the scope of protection given to the invention should not be limited to a particular embodiment, example, or particular embodiment, structure, or arrangement described in a particular figure.

[0453] The present invention may be embodied in forms other than those specifically disclosed herein, without deviating from its essential characteristics. The described embodiments should be recognized in all respects as illustrative and non-limiting.

Claims

1. A method for producing silicon carbide, a. A liquid that is a polysilocarb precursor containing silicon, carbon, oxygen, and a dopant, having a silicon-carbon-oxygen molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon, to which a catalyst is added to produce a liquid in which catalytic action is applied. b. The liquid to which the catalytic action has been applied is cured at a temperature of 70°C or higher in the presence of an inert gas to produce a doped cured product by curing it into a solid material containing silicon, carbon, oxygen, and the dopant and having a purity of at least about 99.99%. c. Converting the doped cured material into a ceramic material essentially composed of doped silicon carbide particulate matter having a certain hardness and a purity of at least about 99.99% at a temperature of 1,750°C or higher, d. To form a volumetric object from the doped silicon carbide particulate material having a hardness less than 1 / 4 of the hardness of the silicon carbide particulate material, Includes, The catalyst is Platinum, dibutyltin dilaurate, zinc octoate, and peroxides; Compounds of titanium, zirconium, rhodium, iridium, palladium, cobalt, and nickel; and Rhodium, rhenium, iridium, palladium, nickel, and ruthenium; A method selected from the group consisting of the following.

2. The method according to claim 1, wherein the molar ratio of silicon, carbon, and oxygen is about 25% silicon, about 50% carbon, and about 25% oxygen.

3. The method according to claim 1, wherein the molar ratio of silicon, carbon, and oxygen is about 20% silicon, about 60% carbon, and about 20% oxygen.

4. A method for producing silicon carbide, a. A catalyst is added to a liquid that is a polysilocarb precursor containing silicon, carbon, oxygen, and a dopant to produce a catalytically activated liquid, and this liquid is cured at a temperature of 70°C or higher in the presence of an inert gas to produce a doped cured product by curing it into a solid material containing silicon, carbon, oxygen, and a dopant with a purity of at least about 99.99%. b. Converting the doped cured material into a ceramic material essentially composed of doped silicon carbide particulate matter having a certain hardness and a purity of at least about 99.99% at a temperature of 1,750°C or higher, c. To form a volumetric object from the doped silicon carbide particulate material having a hardness less than 1 / 4 of the hardness of the silicon carbide particulate material, Includes, The catalyst is Platinum, dibutyltin dilaurate, zinc octoate, and peroxides; Compounds of titanium, zirconium, rhodium, iridium, palladium, cobalt, and nickel; and Rhodium, rhenium, iridium, palladium, nickel, and ruthenium; A method selected from the group consisting of the following.

5. The method according to claim 4, wherein the molar ratio of silicon, carbon, and oxygen in the catalyzed liquid is about 25% silicon, about 50% carbon, and about 25% oxygen.

6. The method according to claim 4, wherein the molar ratio of silicon, carbon, and oxygen in the catalyzed liquid is about 20% silicon, about 60% carbon, and about 20% oxygen.

7. The method according to any one of claims 1 to 6, wherein the silicon carbide has a polytype selected from the group consisting of 3C, 2H, 4H, 6H, 8H, and 15R.

8. The method according to any one of claims 1 to 7, wherein the volumetric shape is selected from the group consisting of packs, briquettes, bricks, pellets, discs, pills, and tablets.

9. The method according to any one of claims 1 to 8, wherein the hardness of the volume-shaped material is less than 1 / 10 of the hardness of the silicon carbide particulate material.

10. The method according to any one of claims 1 to 8, wherein the hardness of the volumetric material is less than 1 / 20 of the hardness of the silicon carbide particulate material.

11. The method according to any one of claims 1 to 8, wherein the hardness of the volume-shaped material is less than 1 / 30 of the hardness of the silicon carbide particulate material.

12. A method for producing silicon carbide, a. A catalyst is added to a liquid that is a polysilocarb precursor containing silicon, carbon, oxygen, and a dopant to produce a catalytically activated liquid, and this liquid is cured at a temperature of 70°C or higher in the presence of an inert gas to produce a doped cured product by curing it into a solid material containing silicon, carbon, oxygen, and a dopant with a purity of at least about 99.99%. b. To form a volumetric object from the doped hardened material, thereby generating a volumetric object of the doped hardened material, c. Converting the volumetric form of the doped cured material into a volumetric form of a ceramic material essentially consisting of doped silicon carbide particulate matter having a purity of at least about 99.99% at a temperature of 1,750°C or higher, Includes, The catalyst is Platinum, dibutyltin dilaurate, zinc octoate, and peroxides; Compounds of titanium, zirconium, rhodium, iridium, palladium, cobalt, and nickel; and Rhodium, rhenium, iridium, palladium, nickel, and ruthenium; A method selected from the group consisting of the following.

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