# US 2013/0158157 A1 · Composite filler particles and process for the preparation thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0158157 A1 - Document ID: US20130158157A1 - Status: Published application - Kind: A1 - Application number: 13/714,803 - Filed: 2012-12-14 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: DENTSPLY International Inc. - Inventors: Simon STELZIG; Jörg Kempter; Stephanie Noerpel; Joachim E. KLEE; Andreas FACHER; Uwe WALZ; Christoph WEBER - Web page: https://patentgrep.com/patent/US20130158157A1 ## CPC - C09D 143/04: Homopolymers or copolymers of monomers containing silicon - A61K 6/17: Particle size - A61K 6/72: comprising nitrogen-containing compounds - A61K 6/75: Apatite - A61K 6/77: Glass - A61K 6/807: comprising magnesium oxide - A61K 6/818: comprising zirconium oxide - A61K 6/822: comprising rare earth metal oxides - A61K 6/887: Compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds - B01J 2/16: by suspending the powder material in a gas, e.g. in fluidised beds or as a falling curtain - B05D 7/24: for applying particular liquids or other fluent materials - C03C 14/008: {the non-glass component being in molecular form} - C03C 17/00: Surface treatment of glass, not in the form of fibres or filaments, by coating (optical coatings of optical elements G02B1/10) - C03C 17/30: with silicon-containing compounds - C08K 3/40: Glass - C08K 5/5419: containing at least one Si—C bond - C09C 1/40: Compounds of aluminium {(C09C1/0009, C09C1/0015, C09C1/0078, C09C1/32 take precedence)} - C09C 3/00: Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties - C09C 3/006: {Combinations of treatments provided for in groups C09C3/04 - C09C3/12} - C09C 3/045: {Agglomeration, granulation, pelleting} - C09C 3/08: Treatment with low-molecular-weight {non-polymer} organic compounds {(C09C3/006, C09C3/048 take precedence)} - C09C 3/12: Treatment with organosilicon compounds {(C09C3/006 takes precedence)} - C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer - C03C 2214/12: Polymers - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - 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 - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS} - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS ## Abstract A process for the preparation of composite filler particles, comprising: (a) coating a particulate filler having a median particle size (D50) of from 1 to 1200 nm; (b) agglomerating the coated particulate filler, for providing a granulation of the coated particulate filler wherein the granulation contains the coated particulate filler particles whereby the at least one coating layer may be crosslinked by crosslinking groups obtained by reacting the reactive groups and optionally a further crosslinking agent. ## Claims ### Claim 1 A process for the preparation of composite filler particles, comprising the steps of: (a) coating a particulate filler having a median particle size (D50) of from 1 to 1200 nm with a coating composition containing a film-forming agent forming a coating layer on the surface of the particulate filler, said coating layer displaying reactive groups on the surface of the coating layer, said reactive groups being selected from addition polymerizable groups and step-growth polymerizable groups, thereby forming a coated particulate filler; subsequently or concurrently (b) agglomerating the coated particulate filler, optionally in the presence of a further crosslinking agent and optionally in the presence of a further particulate filler not displaying reactive groups, for providing a granulation of the coated particulate filler wherein the granulation contains the coated particulate filler particles and the optional further particulate filler particles separated from and connected to each other by at least one coating layer, whereby the at least one coating layer may be crosslinked by crosslinking groups obtained by reacting the reactive groups and optionally a further crosslinking agent, whereby the agglomeration is carried out by spray agglomeration or growth agglomeration; (c) optionally milling, classifying and/or sieving the granulation of the coated particulate filler; and (d) optionally further crosslinking the granulation of the coated particulate filler; wherein the prepared composite filler particles have a median particle size (D50) of from 1 to 70 μm; wherein reactive groups are transformed into crosslinking groups obtained by reacting reactive groups and optionally a further crosslinking agent; and wherein the particulate filler is the main component by volume of the composite filler particles. ### Claim 2 (depends on 1) The process according to claim 1, wherein said reactive groups are selected from step-growth polymerizable groups. ### Claim 3 (depends on 1) The process according to claim 1, wherein the coating composition contains a film-forming agent forming a covalent bond with the particulate composite filler. ### Claim 4 (depends on 3) The process according to claim 3, wherein the covalent bond is obtainable by the reaction of a hydroxyl group on the surface of the composite filler and a silane group. ### Claim 5 (depends on 1) The process according to claim 1, wherein the maximum thickness of the coating layer on the particulate filler is less than the median particle diameter (D50) of the particulate filler. ### Claim 6 (depends on 1) The process according to claim 1, wherein the coating composition comprises one or more polymerizable monomers, and optionally a polymerization initiator and a solvent. ### Claim 7 (depends on 1) The process according to claim 1, wherein the polymerizable composition has a dynamic viscosity in the range of from 0.0001 to 15 Pas (23° C.). ### Claim 8 (depends on 1) The process according to claim 1, wherein the particulate filler is a particulate glass filler. ### Claim 9 (depends on 1) The process according to claim 1, which is carried out in a fluidized bed. ### Claim 10 (depends on 1) The process according to claim 1, wherein the composite filler particles has a median particle size (D50) in the range of from 2 μm to 20 μm. ### Claim 11 (depends on 1) The process according to claim 1, which further includes a step of treating the composite filler particles with a silanating agent or a surface active agent. ### Claim 12 Composite filler particles formed by the process comprising the steps of: (a) coating a particulate filler having a median particle size (D50) of from 1 to 1200 nm with a coating composition containing a film-forming agent forming a coating layer on the surface of the particulate filler, said coating layer displaying reactive groups on the surface of the coating layer, said reactive groups being selected from addition polymerizable groups and step-growth polymerizable groups, thereby forming a coated particulate filler; subsequently or concurrently (b) agglomerating the coated particulate filler, optionally in the presence of a further crosslinking agent and optionally in the presence of a further particulate filler not displaying reactive groups, for providing a granulation of the coated particulate filler wherein the granulation contains the coated particulate filler particles and the optional further particulate filler particles separated from and connected to each other by at least one coating layer, whereby the at least one coating layer may be crosslinked by crosslinking groups obtained by reacting the reactive groups and optionally a further crosslinking agent, whereby the agglomeration is carried out by spray agglomeration or growth agglomeration; (c) optionally milling, classifying and/or sieving the granulation of the coated particulate filler; and (d) optionally further crosslinking the granulation of the coated particulate filler; wherein the prepared composite filler particles have a median particle size (D50) of from 1 to 70 μm; wherein reactive groups are transformed into crosslinking groups obtained by reacting reactive groups and optionally a further crosslinking agent; and wherein the particulate filler is the main component by volume of the composite filler particles. ### Claim 13 (depends on 12) The composite filler particles according to claim 12, wherein said reactive groups are selected from step-growth polymerizable groups. ### Claim 14 (depends on 12) The composite filler particles according to claim 12, wherein the coating composition contains a film-forming agent forming a covalent bond with the particulate composite filler. ### Claim 15 (depends on 14) The composite filler particles according to claim 14, wherein the covalent bond is obtainable by the reaction of a hydroxyl group on the surface of the composite filler and a silane group. ### Claim 16 (depends on 12) The composite filler particles according to claim 12, wherein the composite filler particles has a median particle size (D50) in the range of from 2 μm to 20 μm. ### Claim 17 (depends on 12) The composite filler particles according to claim 12, which further includes a step of treating the composite filler particles with a silanating agent or a surface active agent ### Claim 18 A dental composition comprising composite filler particles formed by the process comprising the steps of: (a) coating a particulate filler having a median particle size (D50) of from 1 to 1200 nm with a coating composition containing a film-forming agent forming a coating layer on the surface of the particulate filler, said coating layer displaying reactive groups on the surface of the coating layer, said reactive groups being selected from addition polymerizable groups and step-growth polymerizable groups, thereby forming a coated particulate filler; subsequently or concurrently (b) agglomerating the coated particulate filler, optionally in the presence of a further crosslinking agent and optionally in the presence of a further particulate filler not displaying reactive groups, for providing a granulation of the coated particulate filler wherein the granulation contains the coated particulate filler particles and the optional further particulate filler particles separated from and connected to each other by at least one coating layer, whereby the at least one coating layer may be crosslinked by crosslinking groups obtained by reacting the reactive groups and optionally a further crosslinking agent, whereby the agglomeration is carried out by spray agglomeration or growth agglomeration; (c) optionally milling, classifying and/or sieving the granulation of the coated particulate filler; and (d) optionally further crosslinking the granulation of the coated particulate filler; wherein the prepared composite filler particles have a median particle size (D50) of from 1 to 70 μm; wherein reactive groups are transformed into crosslinking groups obtained by reacting reactive groups and optionally a further crosslinking agent; wherein the particulate filler is the main component by volume of the composite filler particles; and wherein the dental composition is a dental composite, a dental cement or a resin reinforced dental cement. ### Claim 19 (depends on 18) The dental composition according to claim 18 which further comprises the same type of polymerizable monomer as used for the preparation of the composite filler particles. ### Claim 20 (depends on 12) A method for using the particulate composite filler as defined by claim 12 in a dental composition, wherein the dental composition is a dental composite, a dental cement or a resin reinforced dental cement.