# US 2022/0033618 A1 · Process for preparing dialkyl 1,4-cyclohexanedicarboxylates > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0033618 A1 - Document ID: US20220033618A1 - Status: Published application - Kind: A1 - Application number: 17/385,323 - Filed: 2021-07-26 - Published: 2022-02-03 - Earliest claimed: 2020-07-28 - Assignees: Evonik Operations GmbH - Applicants: Evonik Operations GmbH - Inventors: Johannes Kraft; Lena Altmann; Johan Anton; Michael Grass; Thomas Schneider - Web page: https://patentgrep.com/patent/US20220033618A1 ## CPC - C07C 69/75: of acids with a six-membered ring - C08K 5/12: of cyclic polycarboxylic acids - B01J 21/063: {Titanium; Oxides or hydroxides thereof} - B01J 23/462: {Ruthenium} - C07C 51/36: by hydrogenation of carbon-to-carbon unsaturated bonds - C07C 67/303: by hydrogenation of unsaturated carbon-to-carbon bonds - C09D 7/63: organic - C09J 11/06: organic - Y02P 20/582: Recycling of unreacted starting or intermediate materials - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - 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) - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A process prepares dialkyl 1,4-cyclohexanedicarboxylates by ring hydrogenation of the corresponding dialkyl terephthalate having a CO value of less than 0.3 mg KOH/g. The dialkyl 1,4-cyclohexanedicarboxylates thus produced can be used as plasticizers or as a component of a plasticizer composition for plastics, in particular PVC. ## Claims ### Claim 1 A process for preparing dialkyl 1,4-cyclohexanedicarboxylate in which the two alkyl groups both have at least 2 carbon atoms, the process comprising: carrying out a ring hydrogenation of a dialkyl terephthalate in which the two alkyl groups both have at least 2 carbon atoms, in the presence of a heterogeneous hydrogenation catalyst, with a hydrogen-containing gas, to form the dialkyl 1,4-cyclohexanedicarboxylate, wherein the dialkyl terephthalate in the ring hydrogenation has a CO value of less than 0.3 mg KOH/g. ### Claim 2 (depends on 1) The process according to claim 1, wherein each of the two alkyl groups of the dialkyl 1,4-cyclohexanedicarboxylate have 3 to 10 carbon atoms. ### Claim 3 (depends on 1) The process according to claim 1, wherein the dialkyl terephthalate in the ring hydrogenation is prepared by transesterification of dimethyl terephthalate with an alcohol having at least 2 carbon atoms, or by esterification of terephthalic acid with an alcohol having at least 2 carbon atoms. ### Claim 4 (depends on 3) The process according to claim 3, wherein the alcohol in the transesterification or in the esterification is an alcohol having 3 to 10 carbon atoms. ### Claim 5 (depends on 2) The process according to claim 2, wherein the dialkyl 1,4-cyclohexanedicarboxylate is diisononyl 1,4-cyclohexanedicarboxylate or di-2-ethylhexyl 1,4-cyclohexanedicarboxylate. ### Claim 6 (depends on 1) The process according to claim 1, wherein the heterogeneous hydrogenation catalyst in the ring hydrogenation comprises a transition metal on a support material. ### Claim 7 (depends on 6) The process according to claim 6, wherein the transition metal is a metal of group 8 of the periodic table of the elements. ### Claim 8 (depends on 6) The process according to claim 6, wherein the support material is selected from the group consisting of activated carbon, silicon carbide, aluminium oxide, silicon dioxide, aluminosilicate, titanium dioxide, zirconium dioxide, magnesium oxide, zinc oxide, and mixtures thereof. ### Claim 9 (depends on 8) The process according to claim 8, wherein the support material is titanium dioxide or aluminium oxide. ### Claim 10 (depends on 6) The process according to claim 6, wherein a transition metal content in the heterogeneous hydrogenation catalyst is within a range from 0.1% to 10% by weight. ### Claim 11 (depends on 1) The process according to claim 1, wherein the ring hydrogenation is carried out in at least one hydrogenation unit. ### Claim 12 (depends on 1) The process according to claim 1, wherein a hydrogenation temperature in the ring hydrogenation is within a range from 50 to 250° C. ### Claim 13 (depends on 1) The process according to claim 1, wherein the ring hydrogenation is carried out within a pressure range from 3 to 300 bar. ### Claim 14 (depends on 1) A plasticizer or a component of a plasticizer composition in plastic or a plastic composition, comprising the dialkyl 1,4-cyclohexanedicarboxylate prepared by the process according to claim 1. ### Claim 15 (depends on 1) A composition, comprising: an additive comprising the dialkyl 1,4-cyclohexanedicarboxylate prepared by the process according to claim 1, and a product selected from the group consisting of a paint, a varnish, an adhesive, an adhesive component, a sealant, and a solvent. ### Claim 16 (depends on 1) The process according to claim 1, wherein each of the two alkyl groups of the dialkyl 1,4-cyclohexanedicarboxylate have at least 4 carbon atoms. ### Claim 17 (depends on 1) The process according to claim 1, wherein the dialkyl terephthalate in the ring hydrogenation has a CO value of less than 0.1 mg KOH/g. ### Claim 18 (depends on 2) The process according to claim 2, wherein each of the two alkyl groups of the dialkyl 1,4-cyclohexanedicarboxylate have 9 carbon atoms. ### Claim 19 (depends on 7) The process according to claim 7, wherein the transition metal is ruthenium. ### Claim 20 (depends on 11) The process according to claim 11, wherein the ring hydrogenation is carried out in at least two hydrogenation units connected in series, wherein at least one of the at least two hydrogenation units is operated in loop mode.