# US 11,897,169 B2 · Method for producing spherical thermoplastic polymer particles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,897,169 B2 - Document ID: US11897169B2 - Status: Granted - Kind: B2 - Application number: 17/596,628 - Filed: 2020-06-18 - Published: 2022-08-11 - Granted: 2024-02-13 - Earliest claimed: 2019-06-18 - Assignees: BASF SE - Applicants: BASF SE - Inventors: Andreas Bauder; Kerstin Muelheims; Michael Freese; Achim Stammer - Web page: https://patentgrep.com/patent/US11897169B2 ## CPC - B29B 9/10: by moulding the material, i.e. treating it in the molten state - B29B 9/12: characterised by structure or composition - B29C 48/36: Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B33Y 10/00: Processes of additive manufacturing - B33Y 70/00: Materials specially adapted for additive manufacturing - B33Y 80/00: Products made by additive manufacturing - C08J 3/16: by coagulating dispersions {(C08J3/122 takes precedence)} - C08L 75/06: from polyesters - B29B 9/16: Auxiliary treatment of granules - B29B 2009/125: {Micropellets, microgranules, microparticles} - B29B 2009/166: {Deforming granules to give a special form, e.g. spheroidizing, rounding} - B29K 2075/00: Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material - C08J 2375/04: Polyurethanes - B29B: PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract A process for producing particles of a thermoplastic polymer in spherical form involves providing at least one thermoplastic polymer in a molten state and providing an aqueous solution of at least one surface-active substance. The aqueous solution is in a temperature range from 100 to 300° C. The process also involves dispersing the thermoplastic polymer in the aqueous solution to obtain an aqueous solution containing dispersed thermoplastic polymer, which is cooled down to a temperature below the solidification point of the thermoplastic polymer to obtain a suspension containing an aqueous solution and particles of the thermoplastic polymer suspended in a solid state and in spherical form. The particles can be separated from the suspension and, optionally, dried. The particles obtained from the process have a particle size distribution having a d[4,3] value of more than 10 μm and a d90.3 value of more than 20 μm. ## Claims ### Claim 1 A process for producing particles of a thermoplastic polymer in spherical form, the process comprising: (i) providing at least one thermoplastic polymer in a molten state; (ii) providing an aqueous solution of at least one surface-active substance, wherein the aqueous solution of the at least one surface-active substance is at a temperature in a range from 100 to 300° C.; (iii) dispersing the at least one thermoplastic polymer from (i) in the aqueous solution of the at least one surface-active substance from (ii), to obtain an aqueous solution comprising dispersed thermoplastic polymer; (iv) cooling down the aqueous solution comprising dispersed thermoplastic polymer to a temperature below a solidification point of the at least one thermoplastic polymer, to obtain a suspension comprising an aqueous solution and particles of the at least one thermoplastic polymer suspended therein in a solid state, wherein the particles are in spherical form; (v) separating the particles of the at least one thermoplastic polymer in spherical form from the suspension obtained in (iv); and (vi) optionally, drying the particles of the at least one thermoplastic polymer in spherical form that have been separated off in (v); wherein the particles of the at least one thermoplastic polymer in spherical form that have been separated off in (v) and optionally dried in (vi) have a particle size distribution having a d[4,3] value of more than 10 μm and a d90.3 value of more than 20 μm. ### Claim 2 (depends on 1) The process according to claim 1, wherein (i) comprises: (i.1) providing the at least one thermoplastic polymer in a solid state; and (i.2) melting the at least one thermoplastic polymer to obtain the at least one thermoplastic polymer in the molten state. ### Claim 3 (depends on 1) The process according to claim 1, wherein the at least one thermoplastic polymer in the molten state is dispersed in the aqueous solution of the at least one surface-active substance in (iii) under action of mechanical force, ultrasound, and/or high-pressure homogenization, to obtain the aqueous solution comprising dispersed thermoplastic polymer. ### Claim 4 (depends on 2) The process according to claim 2, wherein the melting in (i.2) is effected in an extruder or by means of extrusion. ### Claim 5 (depends on 1) The process according to claim 1, wherein the dispersing in (iii) is effected at a temperature in a range from 100 to 300° C. ### Claim 6 (depends on 1) The process according to claim 1, wherein the cooling in (iv) is effected to a temperature in a range from 20 to 100° C. ### Claim 7 (depends on 1) The process according to claim 1, wherein the particles of the at least one thermoplastic polymer in spherical form that are separated off in (v) and optionally dried in (vi) have a particle size distribution having a d[4,3] value of more than 20 μm. ### Claim 8 (depends on 1) The process according to claim 1, wherein the particles of the at least one thermoplastic polymer in spherical form that are separated off in (v) and optionally dried in (vi) have a particle size distribution having a d50.3 value of more than 20 μm. ### Claim 9 (depends on 1) The process according to claim 1, wherein the at least one thermoplastic polymer is selected from the group consisting of polyurethane, polyester, polyetherester, polyesterester, polyamide, polypropylene, polyetheramide, polybutadiene-styrene, and ethylene-vinyl acetate. ### Claim 10 (depends on 1) The process according to claim 1, wherein the at least one surface-active substance is selected from the group consisting of polyvinylalcohols. ### Claim 11 (depends on 1) The process according to claim 1, wherein the at least one surface-active substance is present in an amount in a range from 0.1% to 20% by weight, based on a total weight of the aqueous solution of the at least one surface-active substance from (ii). ### Claim 12 (depends on 1) The process according to claim 1, wherein the spherical form of the particles of the at least one thermoplastic polymer is a sphere or an ellipsoid. ### Claim 13 (depends on 7) The process according to claim 7, wherein the particles of the at least one thermoplastic polymer in spherical form that are separated off in (v) and optionally dried in (vi) have a particle size distribution having a d90.3 value of more than 50 μm. ### Claim 14 (depends on 9) The process according to claim 9, wherein the at least one thermoplastic polymer comprises a thermoplastic polyurethane (TPU). ### Claim 15 (depends on 10) The process according to claim 10, wherein the at least one surface-active substance is selected from the group consisting of at least partly hydrolysed polyvinylacetates.