# US 2014/0197583 A1 · Ceramic composition and ceramic injection-molding process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197583 A1 - Document ID: US20140197583A1 - Status: Published application - Kind: A1 - Application number: 14/152,763 - Filed: 2014-01-10 - Published: 2014-07-17 - Earliest claimed: 2013-01-11 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Martin Schubert; Andre Moc; Thomas Loibl; Imke Heeren - Web page: https://patentgrep.com/patent/US20140197583A1 ## CPC - B28B 1/24: by injection moulding {(injection moulding of ceramic slips B28B1/265; of tubular articles B28B21/38)} - C03C 10/0036: {containing SiO2, Al2O3 and a divalent metal oxide as main constituents} - C03C 14/00: Glass compositions containing a non-glass component, e.g. compositions containing fibres, filaments, whiskers, platelets, or the like, dispersed in a glass matrix (devitrified glass ceramics C03C10/00) - C04B 35/117: Composites - C04B 35/634: Polymers (C04B35/636 takes precedence) - C04B 35/64: Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) - C03C 2214/20: Glass-ceramics matrix - C04B 2235/3206: Magnesium oxides or oxide-forming salts thereof - C04B 2235/3208: Calcium oxide or oxide-forming salts thereof, e.g. lime - C04B 2235/3213: Strontium oxides or oxide-forming salts thereof - C04B 2235/349: Clays, e.g. bentonites, smectites such as montmorillonite, vermiculites or kaolines, e.g. illite, talc or sepiolite - C04B 2235/36: Glass starting materials for making ceramics, e.g. silica glass - C04B 2235/6022: Injection moulding - B28B: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER (foundry moulding B22C; working stone or stone-like material B28D; shaping of substances in a plastic state, in general B29C; making layered products not composed wholly of these substances B32B) - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE ## Abstract A ceramic composition for an injection-molding process for producing a combustion chamber pressure sensor, in particular for producing an insulation punch of a combustion chamber pressure sensor, includes a ceramic component in a proportion of greater than or equal to 50% by weight and a glass component in a proportion of less than or equal to 50% by weight. The ceramic component includes aluminum oxide. The glass component includes silicon dioxide or a silicon dioxide precursor. The ceramic composition further includes an alkaline earth metal oxide or an alkaline earth metal oxide precursor. The ceramic composition allows production of an insulation punch having a particularly good insulation capability. A ceramic injection-molding process includes the ceramic composition. ## Claims ### Claim 1 A ceramic composition for an injection-molding process for producing a combustion chamber pressure sensor, comprising: a ceramic component in a proportion of greater than or equal to 50% by weight, the ceramic component comprising aluminum oxide; a glass component in a proportion of less than or equal to 50% by weight, the glass component comprising silicon dioxide or a silicon dioxide precursor; and an alkaline earth metal oxide or an alkaline earth metal oxide precursor. ### Claim 2 (depends on 1) The ceramic composition according to claim 1, wherein the alkaline earth metal oxide or the alkaline earth metal oxide precursor and the silicon dioxide or the silicon dioxide precursor is present in such an amount as to set a ratio of alkaline earth metal oxide to silicon dioxide of 30% by weight:70% by weight to 70% by weight:30% by weight. ### Claim 3 (depends on 1) The ceramic composition according to claim 1, wherein the alkaline earth metal oxide precursor is selected from the group consisting of carbonates. ### Claim 4 (depends on 1) The ceramic composition according to claim 1, wherein the silicon dioxide precursor is selected from the group consisting of talc and lime. ### Claim 5 (depends on 1) The ceramic composition according to claim 1, further comprising a binder system that comprises a mixture including polyvinyl butyral, at least one polyacrylate, at least one polyethylene glycol, and at least one triethanolamine carboxylic ester. ### Claim 6 (depends on 5) The ceramic composition according to claim 5, wherein the binder system comprises: from greater than or equal to 10% to less than or equal to 25% of polyvinyl butyral; from greater than or equal to 15% to less than or equal to 35% of polyacrylate; from greater than or equal to 35% to less than or equal to 60% of polyethylene glycol; and from greater than or equal to 5% to less than or equal to 20% of triethanolamine carboxylic ester, the abovementioned constituents together making up less than or equal to 100%. ### Claim 7 (depends on 1) The ceramic composition according to claim 1, wherein the ceramic composition is used to produce a combustion chamber pressure sensor. ### Claim 8 A ceramic injection-molding process for producing a combustion chamber pressure sensor, comprising: shaping a ceramic composition in an injection-molding apparatus, the ceramic composition including (i) a ceramic component in a proportion of greater than or equal to 50% by weight, the ceramic component comprising aluminum oxide, (ii) a glass component in a proportion of less than or equal to 50% by weight, the glass component comprising silicon dioxide or a silicon dioxide precursor, and (iii) an alkaline earth metal oxide or an alkaline earth metal oxide precursor; removing binder from the shaped composition; and sintering the shaped composition, the shaped composition having optionally been subjected to binder removal. ### Claim 9 (depends on 8) The process according to claim 8, wherein the ceramic composition is homogenized before shaping. ### Claim 10 (depends on 8) The process according to claim 8, wherein the ceramic composition is introduced by 1-point injection into the injection-molding tool. ### Claim 11 (depends on 8) The process according to claim 8, wherein the injection-molding tool has a surface roughness in the range below 10 μm in its interior. ### Claim 12 (depends on 8) The process according to claim 8, wherein sintering the shaped composition is carried out at a temperature in the range from greater than or equal to 1200° C. to less than or equal to 1900° C. ### Claim 13 (depends on 1) The ceramic composition according to claim 1, wherein the injection-molding process is configured to produce an insulation punch of the combustion chamber pressure sensor. ### Claim 14 (depends on 3) The ceramic composition according to claim 3, wherein the alkaline earth metal oxide precursor is selected from the group consisting of calcium carbonate (lime), magnesium carbonate, strontium carbonate, and talc. ### Claim 15 (depends on 7) The ceramic composition according to claim 7, wherein the ceramic composition is used to produce an insulation body of the combustion chamber pressure sensor. ### Claim 16 (depends on 8) The process according to claim 8, wherein the process is configured to produce an insulation body of the combustion chamber pressure sensor.