DE3210289A1 - Application of a production process for a moulding, to be provided with a surface coating, to a carbon fibre-reinforced carbon body - Google Patents
Application of a production process for a moulding, to be provided with a surface coating, to a carbon fibre-reinforced carbon bodyInfo
- Publication number
- DE3210289A1 DE3210289A1 DE19823210289 DE3210289A DE3210289A1 DE 3210289 A1 DE3210289 A1 DE 3210289A1 DE 19823210289 DE19823210289 DE 19823210289 DE 3210289 A DE3210289 A DE 3210289A DE 3210289 A1 DE3210289 A1 DE 3210289A1
- Authority
- DE
- Germany
- Prior art keywords
- carbon
- application
- carbon fiber
- surface coating
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
- C04B35/565—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide
- C04B35/573—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide obtained by reaction sintering or recrystallisation
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/71—Ceramic products containing macroscopic reinforcing agents
- C04B35/78—Ceramic products containing macroscopic reinforcing agents containing non-metallic materials
- C04B35/80—Fibres, filaments, whiskers, platelets, or the like
- C04B35/83—Carbon fibres in a carbon matrix
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
- C04B41/5053—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials non-oxide ceramics
- C04B41/5057—Carbides
- C04B41/5059—Silicon carbide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
- C04B41/81—Coating or impregnation
- C04B41/85—Coating or impregnation with inorganic materials
- C04B41/87—Ceramics
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F7/00—Casings, e.g. crankcases or frames
- F02F7/0085—Materials for constructing engines or their parts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2253/00—Other material characteristics; Treatment of material
- F05C2253/16—Fibres
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Composite Materials (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ceramic Products (AREA)
Abstract
Description
Anwendung eines Herstellungsverfahrens für einen mitApplying a manufacturing process for one with
einem Oberflächenüberzug zu versehenden Formkörper auf kohlefaserverstärkte Kohlenstoffkörper Die Erfindung betrifft die Herstellung von Formkörpern aus kohlefaserverstärktem Kohlenstoff, welche mit einer wärmebeständigen Oberfläche insbesondere aus Siliziumkarbid versehen werden sollen. Das Aufbringen solcher feuerfester Massen beispielsweise durch Aufdampfen bei Temperaturen um 1800 C ist bisher nicht ohne Beschädigung (Risse) der Kohlefasern an der Grundkörperoberfläche möglich mit der zwangsläufigen Folge einer unzureichenden Haftung des betreffenden Oberflächenüberzugs. Daher besteht für den einzelnen Formkörper das Bestreben nach einem Grundkörper aus kohlefaserverstärktem Kohlenstoff mit einem festhaftenden amorphen Kohlenstoffüberzug im jeweils zu vergütenden Oberflächenbereich, welcher dann durch Imprägnieren mit Silizium in der Dampfphase ohne Schwierigkeiten in (das gewünschte) Siliziumkarbid umwandelbar ist. Bisher ist man jedoch bei einem derartigen Kohlenstoffschichtkörper für die Gestaltung des Kohlenstoffüberzugs auf zerspanende Bearbeitungsverfahren angewiesen. So wird beispielsweise ein dünner Kohlenstoffüberzug an der Innenwandung einer zylindrischen Hülse durch Ausfräsen eines Kohlenstoffkerns auf entsprechend geringe Dicke erreicht. In dieser Weise haben selbstverständlich Kohlenstoffüberzüge bei Formkörpern komplizierter Gestalt, wie G»hauseteile von Ventilen, Düsen, Brennkammern und dgl., einen beträchtlichen Anteil an den Material- und Arbeitskosten.a surface coating to be provided on carbon fiber reinforced molded body Carbon bodies The invention relates to the production of molded bodies made of carbon fiber-reinforced Carbon, which has a heat-resistant surface, in particular made of silicon carbide should be provided. The application of such refractory compounds, for example by vapor deposition at temperatures around 1800 C has not been without damage (cracks) the carbon fibers on the body surface possible with the inevitable consequence insufficient adhesion of the surface coating in question. Hence there is the endeavor for a base body made of carbon fiber reinforced for the individual molded body Carbon with a firmly adhering amorphous carbon coating in the respective to be remunerated Surface area, which is then impregnated with silicon in the vapor phase can be converted into (the desired) silicon carbide without difficulty. Until now however, one is in such a carbon composite body for design of the carbon coating relies on machining processes. So will for example a thin carbon coating on the inner wall of a cylindrical one Sleeve achieved by milling out a carbon core to a correspondingly small thickness. In this way, of course, carbon coatings on molded articles are more complicated Shape, like parts of the house of valves, nozzles, combustion chambers and the like, is considerable Share in material and labor costs.
Der Erfindung liegt daher die Aufgabe zugrunde, zur Herstellung eines derartigen mit einem amorphen Kohlenstoffüberzug versehenen kohlefaserverstärkten Kohlenstoff-Formkörpers auf zerspanendes Bearbeiten verzichten zu können.The invention is therefore based on the object to produce a such carbon fiber reinforced ones provided with an amorphous carbon coating Carbon molding to be able to do without machining.
Diese Aufgabe ist erfindungsgemäß durch die Anwendung eines Verfahrens zum Herstellen eines Formkörpers mit einem Oberflächenüberzug durch Einbringen des Formkörpermaterials in eine Form, auf deren Formfläche zuvor das Überzugsmittel zu einer mit dem aus dem Formkörpermaterial geformten Grundkörper unmittelbar sich vereinigenden Schicht aufgetragen wird, mit der Maßgabe gelöst, daß die Schicht aus einem wenigstens zähflüssigen Gemenge von pulverisiertem Kohlenstoff mit einem härtbaren Bindemittel, insbesondere Kunstharz, gebildet und bereits nach dem anschließenden Aushärten gesondert und/oder nach dem Aufbringen von für die Formung des Grundkörpers mit demselben Bindemittel imprägniertem Kohlefasermaterial und dem Aushärten desselben (bzw.This object is achieved according to the invention through the use of a method for producing a molded body with a surface coating by introducing the Molded body material in a mold, on whose mold surface previously the coating agent to a body formed from the molded body material directly unifying layer is applied, with the proviso that the layer from an at least viscous mixture of pulverized carbon with a curable binder, in particular synthetic resin, formed and already after the subsequent Curing separately and / or after the application of for the shaping of the base body carbon fiber material impregnated with the same binder and hardening of the same (respectively.
derselben gemeinsam) hiermit vereint mittels Wärme karbonisiert wird.same together) is hereby carbonized by means of heat.
Das angewandte allgemeine, z.B. durch die DE-PS 22 18 320 bekannte, Verfahren wird bisher zur Oberflächenvergütung von Formkörpern aus härtbarem Kunststoff unter dem Kriterium-eines besonders innigen, unlösbaren Verbundes zwischen dem Grundkörper des Formkörpers und seinem Oberflächenüberzug verwendet. Die vorliegende Erfindung basiert nun auf der Erkenntnis, daß das für die Herstellung der Schicht auf der Formfläche dem Überzugsmittel Kohlenstoff" beigemengte Bindemittel unter der zum Karbonisieren zugeführten Wärme ebenso wie das dem Kohlefasermaterial aus Gründen der Formbarkeit zugesetzte Bindemittel verkokt mit entsprechender Anreicherung von Kohlenstoff, wodurch der Grundkörper und Oberflächenüberzug eine innige Verbindung eingehen. Folglich ist der Formkörper bereits nach dem gemeinsamen Karbonisieren des Grundkörpers und Oberflächenüberzugs bereit für eine Imprägnierung mit Silizium im Sinne der angestrebten Umwandlung des Oberflächenüberzugs in Siliziumkarbid. Da für die Gestaltung des Oberflächenüberzugs von keramischen Formgebungsverfahren, z.B. dem Schlickergießen, Gebrauch gemacht werden kann, ist auch bei komplizierter Geometrie der Oberfläche des Formkörpers eine wirtschaftliche Herstellung sichergestellt. Das wird durch das nachfolgende Ausführungsbeispiel der Erfindung und ihrer in den Unteransprüchen gekennzeichneten Anwendungen weiter verdeutlicht. Hierzu zeigt die Zeichnung im Schnitt einen auf einer Form 1 sitzenden Ventildeckel, der aus einem Grundkörper 2 aus kohlefaserverstärktem Kohlenstoff mit einem inneren Oberflächenüberzug 3 aus Kohlenstoff frei von jeglicher Faser besteht. Zur Herstellung des Ventildeckels wird zunächst ein wenigstens zähflüssiges Gemenge des Kohlenstoffs in Pulverform und Kunstharz als Bindemittel, erforderlichenfalls unter Zusatz eines Verdünners, auf der Formfläche 1.1 in der gewünschten (Millimeter-)Schichtdicke aufgetragen, vorzugsweise durch Schlickergießen unter Verwendung einer Gipsform 1. Danach wird mit Kunstharz getränktes Kohlefasermaterial zur Formung des Grundkörpers 2 aufgebracht, z.B. mehrere Lagen Kohlefasergewebe-Prepregs. Nach dem gemeinsamen Aushärten des Grundkörpers 2 und Oberflächenüberzugs 3 wird die Form 1 entfernt und der Ventildekkel in einem Glühofen etwa bei 13000C karbonisiert. Hierbei erst entsteht die angestrebte innige, bindemittelfreie Verbindung zwischen dem Grundkörper 2 und Oberfläcnenüberzug 3 durch Anreichern von Kohlenstoff infolge der Verkokung des Kunstharzes unter Abgabe der flüchtigen Bestandteile desselben und sonstiger Verunreinigungen. Erforderlichenfalls kann auch bereits vor dem Aufbringen des Kohlefasermaterials der Oberflächenüberzug 3 für sich einer Karbonisierung unterzogen werden, wozu dann natürlich eine feuerfeste Stützform für den vorher ausgehärtet von der Gipsform 1 zu entformenden Oberflächenüberzug 3 erforderlich wird. Sofern die Dichte des Oberflächenüberzugs 3 und auch des Grundkörpers 2 besonders erhöht werden soll, kann natürlich in bekannter Weise ein weiteres Imprägnieren mit solchen Bindemitteln, wie Teer, Pech, Phenolharz und dergleichen, folgen, die bei einem anschließenden erneuten Karbonisieren größere Kohlenstoffanreicherungen ergeben. Im übrigen ist ein letztes Graphitieren bei Tempera-0 turen von etwa 2400°C nicht ausgeschlossen.The general applied, e.g. known from DE-PS 22 18 320, Process has hitherto been used for the surface treatment of moldings made of curable plastic under the criterion of a particularly intimate, indissoluble bond between the base body of the molded body and its surface coating are used. The present invention is now based on the knowledge that the production of the layer on the Molding surface the coating agent carbon "added binder under the Carbonizing heat supplied as well as that of the carbon fiber material for reasons added to the malleability Binder coked with the appropriate Enrichment of carbon, making the base body and surface coating one enter into intimate connection. Consequently, the molded body is already after the common Carbonization of the body and surface coating ready for impregnation with silicon in the sense of the desired conversion of the surface coating into silicon carbide. As for the design of the surface coating of ceramic molding processes, e.g. slip casting, use can be made, is also more complicated Geometry of the surface of the molded body ensures economical production. This is illustrated by the following embodiment of the invention and its in the Applications characterized by subclaims further clarified. The Drawing in section of a valve cover seated on a form 1, which consists of a Base body 2 made of carbon fiber reinforced carbon with an inner surface coating 3 consists of carbon free of any fiber. For the manufacture of the valve cover is first an at least viscous mixture of carbon in powder form and synthetic resin as a binder, if necessary with the addition of a thinner, applied to the mold surface 1.1 in the desired (millimeter) layer thickness, preferably by slip casting using a plaster mold 1. Then carbon fiber material impregnated with synthetic resin is applied to form the base body 2, e.g. several layers of carbon fiber fabric prepregs. After curing the Base body 2 and surface coating 3, the mold 1 is removed and the valve cover carbonized in an annealing furnace at around 13000C. Only then does the aimed at intimate, binder-free connection between the base body 2 and surface coating 3 by enrichment of carbon as a result of the coking of the synthetic resin with the release the volatile constituents of the same and other impurities. If necessary the surface coating can also be applied before the carbon fiber material is applied 3 are subjected to a carbonation, including of course a refractory one Support mold for the previously hardened surface coating to be removed from the plaster mold 1 3 is required. If the density of the surface coating 3 and also of the base body 2 is to be particularly increased, a further impregnation can of course be carried out in a known manner with such binders as tar, pitch, phenolic resin and the like, follow the in a subsequent renewed carbonization, larger carbon accumulations result. In addition, there is a final graphitization at temperatures of around 2400 ° C not excluded.
Die schließlich gewünschte Umwandlung des Oberflächenüberzuges 3 in Siliziumkarbid im Wege eines üblichen Imprägnierverf ahrens mit Silizium in der Dampfphase hat, wie sich gezeigt hat, keinerlei schädigende Auswirkungen auf dessen Haftung an dem Grundkörper 2.The ultimately desired conversion of the surface coating 3 into Silicon carbide by way of a conventional impregnation process with silicon in the As has been shown, the vapor phase has no harmful effects on it Adhesion to the main body 2.
Claims (3)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19823210289 DE3210289C2 (en) | 1982-03-20 | 1982-03-20 | Application and development of a manufacturing process for a molded body to be provided with a surface coating on carbon fiber-reinforced carbon bodies |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19823210289 DE3210289C2 (en) | 1982-03-20 | 1982-03-20 | Application and development of a manufacturing process for a molded body to be provided with a surface coating on carbon fiber-reinforced carbon bodies |
Publications (2)
Publication Number | Publication Date |
---|---|
DE3210289A1 true DE3210289A1 (en) | 1983-09-29 |
DE3210289C2 DE3210289C2 (en) | 1985-08-08 |
Family
ID=6158841
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19823210289 Expired DE3210289C2 (en) | 1982-03-20 | 1982-03-20 | Application and development of a manufacturing process for a molded body to be provided with a surface coating on carbon fiber-reinforced carbon bodies |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE3210289C2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1986004658A1 (en) * | 1985-02-12 | 1986-08-14 | Gevipi A.G. | Hard material seal members having a low friction coefficient |
DE3606179A1 (en) * | 1986-02-26 | 1987-08-27 | Hochtemperatur Reaktorbau Gmbh | Thermally insulated gas duct |
DE4202804A1 (en) * | 1992-01-31 | 1993-08-05 | Man Technologie Gmbh | Fibre composite ceramic article with durable surface - made by applying ceramic foil or consolidation material onto article surface |
WO2003067052A1 (en) * | 2002-02-06 | 2003-08-14 | Man B & W Diesel A/S | Engine |
-
1982
- 1982-03-20 DE DE19823210289 patent/DE3210289C2/en not_active Expired
Non-Patent Citations (1)
Title |
---|
NICHTS-ERMITTELT * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1986004658A1 (en) * | 1985-02-12 | 1986-08-14 | Gevipi A.G. | Hard material seal members having a low friction coefficient |
DE3606179A1 (en) * | 1986-02-26 | 1987-08-27 | Hochtemperatur Reaktorbau Gmbh | Thermally insulated gas duct |
DE4202804A1 (en) * | 1992-01-31 | 1993-08-05 | Man Technologie Gmbh | Fibre composite ceramic article with durable surface - made by applying ceramic foil or consolidation material onto article surface |
WO2003067052A1 (en) * | 2002-02-06 | 2003-08-14 | Man B & W Diesel A/S | Engine |
Also Published As
Publication number | Publication date |
---|---|
DE3210289C2 (en) | 1985-08-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1154970B1 (en) | Fibre-reinforced ceramic body and method for producing same | |
DE69002429T2 (en) | Ceramic composite valve for internal combustion engines and the like. | |
DE3827126A1 (en) | HOLLOW COMPOSITE BODY WITH A SYMMETRY AXIS, AND PRODUCTION METHOD FOR THIS | |
DE2206700A1 (en) | METHOD FOR MANUFACTURING FIBER-REINFORCED COMPOSITE BODIES | |
EP0049447B1 (en) | Method for the production of silicon carbide bodies or of graphite or graphite-like matter having a silicon carbide surface | |
EP1008569A1 (en) | Method of making a short carbon fibre-reinforced silicon carbide composite material | |
WO1999041069B1 (en) | Method for producing a fibre composite | |
DE2256326B2 (en) | Process for the production of a shaped body from a mixture of alpha silicon carbide, graphite and a binder | |
DE10164627C1 (en) | Production of hollow bodies made from fiber-reinforced ceramic materials used in the production of brake and clutch disks comprises forming molding cores | |
DE19719634C1 (en) | Brake unit with a ceramic brake disk bolted to a hub | |
DE10014418C2 (en) | Process for the production of a fiber-reinforced structural component and brake disk manufactured therefrom | |
EP1323685B1 (en) | Method of production of shaped bodies out of fibre reinforced ceramic materials | |
DE10148659C1 (en) | Production of hollow bodies made from fiber-reinforced ceramic materials, used in brake and clutch disk production, comprises forming cores, forming green body from cores and carbonizing | |
DE102015201119B4 (en) | Production process of ceramic matrix semi-finished products | |
DE3210289A1 (en) | Application of a production process for a moulding, to be provided with a surface coating, to a carbon fibre-reinforced carbon body | |
DE3736680C1 (en) | Process for the production of carbon-bonded refractory molded parts | |
EP2129639B1 (en) | Method for the production of a component from fiber-reinforced ceramic, particularly for use as an engine component | |
DE4331307C2 (en) | Manufacture of a carbon fiber reinforced composite and its use | |
DE102005042870B3 (en) | Process for the preparation of siliconized molded bodies | |
DE2325163C3 (en) | Process for producing carbon bodies | |
DE102019100735B3 (en) | Process for producing a shaped body and shaped body | |
DE4301396C2 (en) | Process for the production of porous fiber components | |
EP1431260A1 (en) | Method of production of hollow bodies out of fibre reinforced ceramic materials | |
EP0222389A1 (en) | Process for producing silicon carbide articles | |
DE3124364A1 (en) | Carbon fibre-reinforced, highly rigid lightweight composite material consisting of a carbon skeleton and a resin matrix filling the pores |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
OP8 | Request for examination as to paragraph 44 patent law | ||
D2 | Grant after examination | ||
8364 | No opposition during term of opposition | ||
8320 | Willingness to grant licences declared (paragraph 23) | ||
8339 | Ceased/non-payment of the annual fee |