Microencapsulated Catalyst-Ligand System

Abstract

A microencapsulated catalyst-ligand system is provided comprising a catalyst and a ligand microencapsulated within a permeable polymer microcapsule shell, wherein the ligand is a polymeric ligand. Processes for the preparation of said microencapsulated catalyst-ligand system are also provided.

1 . A microencapsulated catalyst-ligand system comprising a catalyst and a ligand microencapsulated within a permeable polymer microcapsule shell, wherein the ligand is a polymeric ligand. 
   
   
       2 . A system according to  claim 1 , wherein the microcapsule shell is obtainable by interfacial polymerisation. 
   
   
       3 . A system according to  claim 2 , which is obtainable by a process comprising forming a permeable microcapsule shell by interfacial polymerisation in the presence of a catalyst and a ligand. 
   
   
       4 . A system according to  claim 1 , wherein the permeable polymer microcapsule shell is the product of self-condensation and/or cross-linking of etherified urea-formaldehyde resins or prepolymers in which from about 50 to about 98% of the methylol groups have been etherified with a C4-C10 alcohol. 
   
   
       5 . A system according to  claim 1 , wherein the permeable polymer microcapsule shell is a polyurea microcapsule prepared from at least one polyisocyanate and/or tolylene diisocyanate. 
   
   
       6 . A system according to  claim 5 , wherein the polyisocyanates and/or tolylene diisocyanates are selected from the group consisting of 1-chloro-2,4-phenylene diisocyante, m-phenylene diisocyante (and its hydrogenated derivative), p-phenylene diisocyante (and its hydrogenated derivative), 4,4′-methylenebis(phenyl isocyanate), 2,4-tolylene diisocyanate, tolylene diisocyanate (60% 2,4-isomer, 40% 2,6-isomer), 2,6-tolylene diisocyante, 3,3′-dimethyl-4,4′-biphenylene diisocyante, 4,4′-methylenebis (2-methylphenyl isocyanate), 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 2,2′,5,5′-tetramethyl-4,4′-biphenylene diisocyanate, 80% 2,4- and 20% 2,6-isomer of tolylene diisocyanate, polymethylene polyphenylisocyante (PMPPI), 1,6-hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate and 1,5-naphthylene diisocyanate. 
   
   
       7 . A system according to  claim 1 , wherein the catalyst is an inorganic catalyst, preferably a transition metal catalyst. 
   
   
       8 . A system according to  claim 7 , wherein the catalyst is a transition metal catalyst, wherein the transition metal is platinum, palladium, osmium, ruthenium, rhodium, iridium, rhenium, scandium, cerium, samarium, yttrium, ytterbium, lutetium, cobalt, titanium, chromium, copper, iron, nickel, manganese, tin, mercury, silver, gold, zinc, vanadium, tungsten and molybdenum. 
   
   
       9 . A system according to  claim 8 , wherein the catalyst is a transition metal catalyst wherein the transition metal is palladium, preferably the palladium is in the form of an organic solvent soluble form and, for example, is palladium acetate. 
   
   
       10 . A system according to  claim 1 , wherein the ligand is obtainable by polymerisation of a ligand of formula (1):
   PR 1 R 2 R 3   (1)   
     wherein:
 R 1 , R 2  and R 3  are each independently an optionally substituted hydrocarbyl group, an optionally substituted hydrocarbyloxy group, or an optionally substituted heterocyclyl group or one or more of R 1  & R 2 , R 1  & R 3 , R 2  & R 3  optionally being linked in such a way as to form an optionally substituted ring(s); and 
 at least one of R 1 , R 2  and R 3  comprises a polymerisable group. 
 
   
   
       11 . A system according to  claim 10 , wherein at least one of R 1 , R 2  and R 3  comprises a styryl group. 
   
   
       12 . A system according to  claim 11 , wherein the ligand of formula (1) is selected from (4-styryl)diphenylphosphine, di-(4-styryl)phenylphosphine, tri-4-styrylphosphine, and corresponding 2-styryl and 3-styryl isomers thereof, (4-styryl)di-2-tolylphosphine, di-(4-styryl)-2-tolylphosphine, (4-styryl)di-2-tolylphosphine, di-(4-styryl)-2-tolylphosphine and corresponding 2-styryl and 3-styryl isomers thereof, allyldiphenylphosphine, diallylphenylphosphine, triallylphosphine, allydibutylphosphine, vinyldiphenylphosphine, divinylphenylphosphine, trivinylphosphine, and the following ligands: 
     
       
         
         
             
             
         
       
     
   
   
       13 . A system according to  claim 1 , wherein the ligand is obtainable by polymerisation of a ligand comprising a cyclopentadienyl group. 
   
   
       14 . A system according to  claim 1 , wherein the ligand is obtainable by free radical polymerisation of a polymerisable ligand. 
   
   
       15 . A system according to  claim 1 , wherein the ligand is copolymerised with the microcapsule shell. 
   
   
       16 . A system according to  claim 15 , wherein the ligand is obtainable by copolymerisation of a polymerisable ligand comprising a hydroxy, amino or mercapto group; and a polyisocyanate. 
   
   
       17 . A system according to  claim 15 , wherein the ligand is obtainable by copolymerisation of a polymerisable ligand selected from β-diketones, β-ketoesters, β-ketoamides, β-dicarboxylic acids and derivatives thereof; and a polyisocyanate. 
   
   
       18 . A system according to  claim 17 , wherein the polymerisable ligand is selected from malonic acid and esters or amides thereof, malononitrile, cyanoacetic acid and esters or amides thereof, and acetoacetate compounds. 
   
   
       19 . A system according to  claim 17 , wherein the polymerisable ligand is complexed with a transition metal, for example, selected from Ni, Pd, Pt, Rh, Ru, as and Ir. 
   
   
       20 . A system according to  claim 19 , wherein the complex is a nickel (II)-β-diketone complex. 
   
   
       21 . A process for the preparation of a microencapsulated catalyst-ligand system, which comprises:
 (i) forming a microcapsule shell by interfacial polymerisation in the presence of a catalyst and a ligand;   (ii) forming a microcapsule shell by interfacial polymerisation in the presence of a catalyst and treating the microcapsule shell with a ligand; or   (iii) forming a microcapsule shell by interfacial polymerisation in the presence of a ligand and treating the microcapsule shell with a catalyst solution;   
     wherein the ligand is a polymerisable ligand and the process further comprises polymerising the ligand prior to, during or after formation of the microcapsule shell. 
   
   
       22 . A process according to  claim 21 , which comprises forming a microcapsule shell by interfacial polymerisation in the presence of a catalyst and a ligand. 
   
   
       23 . A process according to  claim 22 , which comprises
 (a) dissolving or dispersing the catalyst and a ligand in a first phase,   (b) dispersing the first phase in a second, continuous phase to form an emulsion,   (c) reacting one or more microcapsule wall-forming materials at the interface between the dispersed first phase and the continuous second phase to form a microcapsule polymer shell encapsulating the dispersed first phase core, and optionally   (d) recovering the microcapsules from the continuous phase.   
   
   
       24 . A process according to  claim 21 , which comprises forming a microcapsule shell by interfacial polymerisation in the presence of a catalyst and treating the microcapsule shell with a ligand. 
   
   
       25 . A process according to  claim 24 , which comprises
 (a) dissolving or dispersing the catalyst in a first phase,   (b) dispersing the first phase in a second, continuous phase to form an emulsion,   (c) reacting one or more microcapsule wall-forming materials at the interface between the dispersed first phase and the continuous second phase to form a microcapsule polymer shell encapsulating the dispersed first phase core, and   (d) treating the microcapsules with a ligand.   
   
   
       26 . A process according to  claim 21 , which comprises forming a microcapsule shell by interfacial polymerisation in the presence of a ligand and treating the microcapsule shell with a catalyst solution. 
   
   
       27 . A process according to  claim 26 , which comprises
 (a) dissolving or dispersing the ligand in a first phase,   (b) dispersing the first phase in a second, continuous phase to form an emulsion,   (c) reacting one or more microcapsule wall-forming materials at the interface between the dispersed first phase and the continuous second phase to form a microcapsule polymer shell encapsulating the dispersed first phase core, and   (d) treating the microcapsules with a solution of a catalyst.   
   
   
       28 . A process according to  claim 21 , wherein the interfacial polymerisation comprises self-condensation and/or cross-linking of etherified urea-formaldehyde resins or prepolymers in which from about 50 to about 98% of the methylol groups have been etherified with a C4-C10 alcohol. 
   
   
       29 . A process according to  claim 21 , wherein the interfacial polymerisation comprises condensation of at least one polyisocyanate and/or tolylene diisocyanate. 
   
   
       30 . A process according to  claim 29 , wherein the polyisocyanates and/or tolylene diisocyanates are selected from the group consisting of 1-chloro-2,4-phenylene diisocyante, m-phenylene diisocyante (and its hydrogenated derivative), p-phenylene diisocyante (and its hydrogenated derivative), 4,4′-methylenebis(phenyl isocyanate), 2,4-tolylene diisocyanate, tolylene diisocyanate (60% 2,4-isomer, 40% 2,6-isomer), 2,6-tolylene diisocyante, 3,3′-dimethyl-4,4′-biphenylene diisocyante, 4,4′-methylenebis (2-methylphenyl isocyanate), 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 2,2′,5,5′-tetramethyl-4,4′-biphenylene diisocyanate, 80% 2,4- and 20% 2,6-isomer of tolylene diisocyanate, polymethylene polyphenylisocyante (PMPPI), 1,6-hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate and 1,5-naphthylene diisocyanate. 
   
   
       31 . A process according to  claim 29 , wherein a cross-linking reagent is present. 
   
   
       32 . A process according to  claim 29 , wherein unreacted amine groups are converted to urea, amide or urethane groups by post reaction with a monoisocyanate, acid chloride or chloroformate. 
   
   
       33 . A process according to  claim 21 , wherein the catalyst is an inorganic catalyst, preferably a transition metal catalyst. 
   
   
       34 . A process according to  claim 33 , wherein the catalyst is a transition metal catalyst wherein the transition metal is platinum, palladium, osmium, ruthenium, rhodium, iridium, rhenium, scandium, cerium, samarium, yttrium, ytterbium, lutetium, cobalt, titanium, chromium, copper, iron, nickel, manganese, tin, mercury, silver, gold, zinc, vanadium, tungsten and molybdenum. 
   
   
       35 . A process according to  claim 34 , wherein the catalyst is a transition metal catalyst wherein the transition metal is palladium, preferably the palladium is in the form of an organic solvent soluble form and most preferably is palladium acetate. 
   
   
       36 . A process according to  claim 21 , wherein the ligand is polymerised prior to formation of the microcapsule shell. 
   
   
       37 . A process according to  claim 21 , wherein the ligand is polymerised during formation of the microcapsule shell. 
   
   
       38 . A process according to  claim 21 , wherein the ligand is polymerised after formation of the microcapsule shell. 
   
   
       39 . A process according to  claim 21 , wherein the ligand is an organic moiety comprising one or more heteroatoms selected from N, O, P and S. 
   
   
       40 . A process according to  claim 39 , wherein the ligand is an organic ligand of formula (1):
   PR 1 R 2 R 3   (1)   
     wherein:
 R 1 , R 2  and R 3  are each independently an optionally substituted hydrocarbyl group, an optionally substituted hydrocarbyloxy group, or an optionally substituted heterocyclyl group or one or more of R 1  & R 2 , R 1  & R 3 , R 2  & R 3  optionally being linked in such a way as to form an optionally substituted ring(s); and 
 at least one of R 1 , R 2  and R 3  comprises a polymerisable group. 
 
   
   
       41 . A process according to  claim 39 , wherein at least one of R 1 , R 2  and R 3  comprises a styryl group. 
   
   
       42 . A process according to  claim 40 , wherein the ligand of formula (1) is selected from (4-styryl)diphenylphosphine, di-(4-styryl)phenylphosphine, tri-4-styrylphosphine, and corresponding 2-styryl and 3-styryl isomers thereof, (4-styryl)di-2-tolylphosphine, di-(4-styryl)-2-tolylphosphine, (4-styryl)di-2-tolylphosphine, di-(4-styryl)-2-tolylphosphine and corresponding 2-styryl and 3-styryl isomers thereof, allyldiphenylphosphine, diallylphenylphosphine, triallylphosphine, allydibutylphosphine, vinyldiphenylphosphine, divinylphenylphosphine, trivinylphosphine, and the following ligands: 
     
       
         
         
             
             
         
       
     
   
   
       43 . A process according to  claim 39 , wherein the ligand comprises a cyclopentadienyl group. 
   
   
       44 . A process according to  claim 21 , wherein the ligand is polymerised by free radical polymerisation. 
   
   
       45 . A process according to  claim 21 , wherein the ligand is copolymerised with the microcapsule shell or a constituent (e.g. a monomer or prepolymer) thereof. 
   
   
       46 . A process according to  claim 45 , wherein the ligand comprises a hydroxy, amino or mercapto group and the microcapsule shell or constituent thereof comprises a polyisocyanate. 
   
   
       47 . A process according to  claim 45 , wherein the ligand is selected from β-diketones, β-ketoesters, β-ketoamides, β-dicarboxylic acids and derivatives thereof; and the microcapsule shell or constituent thereof comprises a polyisocyanate. 
   
   
       48 . A process according to  claim 47 , wherein the ligand is selected from malonic acid and esters or amides thereof, malononitrile, cyanoacetic acid and esters or amides thereof, and acetoacetate compounds. 
   
   
       49 . A process according to  claim 47 , wherein the ligand is complexed with a transition metal, for example, selected from Ni, Pd, Pt, Rh, Ru, as and Ir. 
   
   
       50 . A process according to  claim 49 , wherein the complex is a nickel (II)-β-diketone complex. 
   
   
       51 . A microencapsulated catalyst-ligand system obtainable by a process of  claim 21 .