CA2188921A1 - Catalyst system and process for the preparation of copolymers of carbon monoxide and olefinically unsaturated compounds - Google Patents

Abstract

A catalyst system suitable for the copolymerization of carbon monoxide with an ethylenically unsaturated compound which catalyst system is based on (a) a source of palladium cations, and (b) a bidentate ligand of the general formula R1R2P-CH2-CH2-PR3R4 wherein R1 represents a phenyl group substituted with a polar group at one or both ortho-positions and/or the para-position with respect to the phosphorus atom to which the said phenyl group is linked, and R2, R3 and R4 independently represent a substituted or non-substituted hydrocarbyl group; and a process for the preparation of copolymers of carbon monoxide and an ethylenically unsaturated compound by reacting the monomers in the presence of said catalyst system.

Description

2 1 8892~
~ WO 95/29946 P~_l/~- '78 CATALYST SYSTEM AND PROCESS FOR T~!E PREPA~ATION OF COPOLYMERS OF

The invention relates to a process for the pr~paration of copolymers of carbon monoxide and one or more ethylenically unsaturated compounds.
Linear copolymers of carbon monoYide with one or more ethylenically unsaturated compounds, in which copolymers the units originating from carbon monoxide on the one hand and the units originating from the ethylenically unsaturated compound(s) on the other hand occur in a substantially alternating illrrAr ', can be prepared by reacting the monomers under polymerization conditlons in the presence of a sultable palladium comprlsing catalyst system.
The linear copolymers, thus prepared, are eminently suitable for use in various outlets for th~rr~rlAetics. They may be further processed by means of conventional ~"'hn~ 's into films, sheets, plates, fibres and shaped articles for domestic use and for parts in the car industry. A suitable method for the preparation of the said copolymer which is usually performed in batch operation, is described ln EP-A-181014 and EP-A-121965.
In this process, use is made of a catalyst, obtained by reaction of, in particular, a palladium compound, an anion of a carboxylic acid with a pKa lower than 2 and a bidentate ligand of the general formula QlQ2M-X-MQ3Q4, wherein ~ represents rhr~rh~r~e~
arsenic or antimony, X r~rr~C~n~e a divalent organic bridging group having at least two carbon atom~s in the bridge, none of which carries steric hindrance causing substituents, and Ql, Q2, Q3 and Q4 are similar or ~iccim;lAr hydrocarbon groups.
It was of course Arrr~ At~ that in the preparation of the copolymers, the catalyst and the polymerization conditions had to be selected such th~t copolymers with high molecular weights are formed, since in general products with higher molecular weights are more suitable for the abo~ n~i uses.

-WO9S/~9946 2 1 8~ 92 ~ 1678 ~
The formation of high molecular weight copolymers is enhanced by p~rfnrm~r,~ the reaction at a low reaction t, r~ltllre, Unfortunately, at the low reaction temperatures suitable for preparing copolymers with sllffi.-~ntly high molecular w~ight, the activity of the initially used cat~lysts often proved to be in~dequate for achieYing ~ viable production rate. By increasing the temperature, the rate of copolymer form~tion could be improved, but the molecular weight of the copolymers will then drop.
Many attempts have therefore been made to find a mode for producing copolymers of high molecular weight at an ACr~rt~l e r~te.
These ~ttempts have e5pecially focused on modifications of the cat~lyst system, whereby, in particular, the influence or m~ny different lig~nds has been investigated. Whilst it was soon evident that the results obtained with bidentate ligands were generally superior to those obtainable with monodentate ligands and th~t phosphine ligands were usually more suitable than the corresponding arsine and atibine liganda, the effects resulting from changeJ in the various groups Ql, Q2, Q3, Q4 and X in the ligands of the above formula, were by no means predictable.
E~rom the results hitherto obtained, it would appear that the reaction rate is significantly increased by using a h~ ~rhn~rhi n-.
ligand of the iormula QSQ6p-x-pQ7Q8~ wherein 2t least one of the groups QS Q8 represents an aryl group ~-nnt~in~n~ at least one polar substituent in an ortho-position with respect to phosphorus. A
process of this type is disclosed in EP-A-319083 and in EP-A-257663.
It would further appear that the activity of catalysts comprising a bident~te lig~nd of the general formula QlQ2M_Xl_MQ3Q4 wherein xl represents a bivalent bridging group containing three atoms in the bridge, viz. two carbon atoms and a hetero-atom or, more preferably, three carbon Atoms, is substantially higher than that of cat~lysts comprising a similar ligand wherein the bridging group consists of only two, or four bridging atoms (cf. EP-A-121965).
Whilst it thus proved indeed possible to select lig~nds for ,-nrrnr..ti,,n in cat~lyst compositions of adequate activity for 21~921 WO95/29946 r.~ 1678 preparing the envisaged copolymers, it was ohserved that the bulk density of the obtaincd product5 still formed a problem.
Apart from the molecular weight, the bulk density, expressed in kg copolymers per m3 r~action medium, represents an important property of the copolymers at issue. The bulk density plays an important role both in the preparatlon of the copolymers and in the treatment, storage, transport and processing thereof, ~In~.Yr~t~.~lly~ it has now been found that by using a catalyst system ,; ci n~ a specific type of hi ~rhnc,rhi n~ ligand wherein the two phosphorous atoms are separat~d by an ethylene brLdge, copolymers with a high bulk den5ity are obtained at an acceptable and in many cases high reaction rate.
US-A-5010170 disclosed that in the r~ li /bidentate ligand catalyzed copolymerization of carbon monoxide with olefins the use of a mixture o~ phosphorus bidentate ligands leads to a decrease of reactor fouling. The ligand mixture comprises a bidentate ligand c~rrying at the phosphorus atoms ~our ortho-alkoxy substituted aryl groups and a bidentate ligand carrying at the phosphorus atoms four aryl groups which are free of alkoxy substitution. An example of a ligand with ortho-alkoxy substitution is 1,2-bis[bis(2,4-diethoxy-phenyl)phosphino]ethane. This document does not provide any teaching which could bring the skilled person to the present invention .
~rhe present invention relates to a catalyst system suitable for the copolymerization of carbon monoxide with an ethylenically unsaturated compound which catalyst system is based on (a) a source of palladium cations, and (b) a bidentate ligand of the general formula RlR2P-Ch'2-Ch2-PR3R4 (I) wherein Rl represents a phenyl group substituted with a polar group at one or both ortho-positions and/or the para-position with respect to the rhncrhnrl-c atom to which the said phenyl group is linked, and R2, R3 and R4; ~ n~ l y represent a substituted or n.,.. ..,,L,Lltuted hydrocarbyl group.
When the catalyst system is based on a mixture of bidentate ligands, the quantity of bidentate ligands of the general WO95/29946 8 ~ ~ 01678 formula (I) in the ligand mixture is preferably at least 95 9~-mole, in particular more than 98 Q;-mole, relative to the total quantity of the bidentate ligands. Such a ligand mixture may comprise a bidentate ligand of the general formula (I) wherein each of Rl, R2, R3 and R4 carr~es an alkoxy group at an ortho-position with re~pect to the phosphorus atom and a bidentate ligand of the general formula R5R6P-X2-PR7R8 wherein R5, R6, R7 and R8 t ."1~ ,.. 1. ~1 y represent aryl groups, typically o~ up to lO carbon atoms, which are free of alkoxy substituents ~nd x2 represents a divalent hydrocarbyl group typic~lly having 2-4 carbon ~toms in the bridge. Such a ligand mixture is typlcally pr~sent in a quantlty of 0.5 - 2 mole per gram atom of r~ nd m~y be used in the catalyst system which is in addition based on an anion of ~n acid having a pKa of less than 4, typically in a c~uantity of 0.5 - 50 equivalents per gram atom r~l 1,.,:;
Bidentate ligands of the general formula ~I) are prefer~bly applied as the sole ligands.
In addition, the invention relates to a process for the preparation of copolymers of carbon monoxide and an ethylenically unsaturated compound by reacting the monomers in the pre~ence of a catalyst system according to this invention.
As source of palladium cations, i.e. component (a) of the catalyst system, conveniently a palladium salt is used. Suitabl~
salts include salts of mineral acids such as sulphuric acid, nitric acid, phosphoric acid and sulphonic acids. Preferably, a palladium salt of a carboxylic acid is used, for example a carboxylic ~cid with up to 8 carbon ~toms, such as acetic acid, trifluoro~cetic acid, trichloroacetic acid, propionic ~cid and citric ~cid.
P~lladium- tII)-acet~te represents a particularly preferred source of palladium cations.
In the bidentate ligands of formula ~I), component ~b) of the c~talyst system, Rl rep~esents a phenyl group substituted with one or more polar groups. The polar group~s) may be located at an ortho posltion with respect to the phosphorus atom to which Rl is linked, at the p~ra-position, or, in the event of more than one polar group, ~921 wo g5ng946 ~ ~ a r~ 78 at both or~ho-positiona, or at an ortho- and the para-position. A
single polar substituent, located 2t zn ortho-position i8 preferred.
Suitable polar groups include ~lkoxy groups and thio-alkyl groups such as a thiomethyl group.
Alkoxy groups are preferred, in particular Cl-C4 alkoxy groups, Cl-C4 having its usual meaning, ~n~iirA~in~ methyl, ethyl, propyl, iaopropyl n-butyl, sec.butyl, isobutyl and tertiary butyl.
The pre-ence of a methoxy group in Rl at an ortho-position with respect to the phosphorus atom, is most pref~rred.
It is ~. ' to use a catalyst system comprising a ligand of formulz (I~ wherein each of R2, R3 and R4 represents an aryl group, typically having up to 10 carbon atoms, in particular a phenyl group. The aryl groups are preferably substituted with a polar group.
Preferably, R2, R3 and R4 all have the same meaning as Rl.
Ar~nr-i~n~ly, a particularly preferred bidentate ligand of formula (I) is 1,2-bis[di(2-methosyphenyl)phoshino~ethane.
The amount of bidentate ligand supplied to the catalyst system may vary, but is conveniently selected in the range from 0 . 5 to 2 moles of bidentate ligand per gram atom of ~ 1; . Preferably, the amount is in the range of 0.75 to 1.5 moles of ligand per gramatom of r.ll~i The catalyst system may be based on an additional component which is generally thought to function during the copolymerization as a source of anions which are non- or only weakly co-ordinating with rs~ li Suitable additional components are, for example, protic acids, salts of protic acids, Lewis acids, in~ nc of Lewis acids and protic acids, and salts derivable from such combinations. Suitable are 5trong acids, in particular having a pKa of less than 3, more in particular le5s than 2, when measured in aqueous solution at 18 C. Examples of suitable acids are the above mentioned acids which may also particip~te in the palladium salts, e . g. trifluoroacetlc acid. Other suitable acids are adducts of boric acid and 1,2-diols, catechols or salicylic acids. Salts of 35 the~e acids may be used as well. Other suitable salts contain one wo g5ng946 ~1~ 8 9 21 r~ 78 or more hydroc~rbylborate anions or carborate anions, such as sodium tetrakis[bis-3,5-(triflUorOm~thyl)phenyl]bOrate, lithium tetraki~-(perfluorophenyl)borate and cobalt c~rbor~te (Co(BllC}~12)2).
Suitable Lewis acid~ are, for example, BF3, SnC12, SnF2 zmd Sn(CF35O3)2~ and hydrocarbylborAnes, such as triphenylborane, tris-(perfluorophenyl)borane ~md tris[bis-3,5-(tr; fl~A ' yl)phenyl] -bor~ne. Protic acid~ with which Lewis acids may be combined are for example sulphonic acid5 and hy~irnhAl ,ng~n~ C acids, in particular hF.
An example of a, inAt;nn of a Lewis acid with a protic ncid is t trAfll-nhort-- acid (HBP4). Other compounds which may be mentioned in thi~ context Are Al 'n~T~nf.C~ in particular methyl Al 'nnTAn~.
and t-butyl Al 'nnY'n~S.
It is in particular advantageous when the additional component on which the catalyst system is b~sed contains boron. It is in particular a boron contzining Lewis acid, protic acid or salt. Very good results can be obtained with An boron rnntA;n1n~ protic acid h2ving a pKa of less than 2 which is tetrafluoboric acid.
The Amount of the ~A~t; tt nnAl component which is generally thought to function AS an anion source is preferably selected in the range of 0.5 to 50 les per gram atom of rAllA~i; in particular in the range of l to 25 moles. }lowever, the Al nnT~n-C may be used in such ~ quantity that the molar r~tio o aluminium to palladium is in the range of 4000:1-10:1, preferably 2000:1-100:1.
The activity of the cataly6t system is such, that amounts in the rAnge from 10-8 to 10 l gram atom of palladium per mole oi ethylenically ~n~tllrAt~t compound to be copolymerized, Are adequate. Preferably, the amount will be between 10-7 to 10-2, on the s~me basis.
As regards the ethylenically unsaturated compound, as starting material for the process of the invention, olefins are preferred, in p~rticular lower olefins, i.e. ethene and propene or mixtures thereof. Ethene is most preferred as monomer for the copoly-rt7~t;Gn with c~rbon monoxide, in p~rticular as the sole or substantially sole ethylenically unsaturated compound. Py the term '~5llh~tAnt; Al 1 y it is expressed that the presence of a quantity of ~1 88921 WO95129946 r~ l"- 1678 ~nother ethylenically unsaturated compound may b~ tolerable, in particular such that the other ethylenically unsaturated compound is incorporated in the copolymer in a qu2ntity of less than 2 ~-mole, preferably less than 1 9~-mole, ~ c~ d on the total of ethylenically lln~?tl~r~t~l compounds ;nr~rrcrAte~t The starting materials are conveniently applied in ratioa such that per mole of c~rbon monoxide 0.25 to 4 moles of ethylenically un3atur~ted compound(s) is (are) present. Preferably the molar ratio between the two monomers is in the range of 3:1 to 1:3, in particular in the 0 range of 1.5:1 to 1:1.5.
The process of the invention is conveniently carried out in the presence of a suitable diluent. Since the copolymers of the invention are insoluble or virtually insoluble in many conventional lic,uid solYents, a large number of these liquids may be used as diluent during the copol~ r; 7~tt~m reaction. ~: ' ' diluents are polar organic liquids, such as ketones, ethers, esters or ~mides. Preferably, protic liquids are used, such as monohydric and dihydric alcohols.
It has be~n observed that by using a lower primary alcohol haYing at most 4 carbon atoms per molecule, the reaction rate of the copolymeriYation reaction is generally higher than in a medium whereby the diluent is a tertiary alcohol. ~ rttn~ly~ lower primary alcohols having at most 4 carbon atoms per molecule are in particular ' I, methanol being an eminently suitable diluent.
S lrrr~ .~t n~l y~ it was found that by using a mixture of a primary alcohol having at most 4 c~rbon atoms and a tertiary alcohol, having at most 10 carbon atoms per molecule, not only a high reaction rate is obt~ined, but in addition the resulting copolymers exhibit a high limiting viscosity number (LVN) (The Limiting Viscosity Number, or intrinsic viscosity, is ~lcl~lAt~d from determined viscosity values, mea~ured for different copolymer f~ n~rA~t~nf~ in m-cresol at 60 C. The primary alcohol ~nd the tertiary alcohol are preferably present at a molar r~tio between 30:70 and 70:30.

21 88q21 W0 95/~9946 1~ 1678 A high LVN is indicative of d high molecular weight of the copolymer .
For ex~mple, by using a mixture of methanol and tertiary butanol at a 1:1 volume ratio a copolymer h~vlng a high LVN is produced at a high re~ction rate.
On the other hand, the use of a mixture of a primary ~nd ~
tertiary alcohol as diluent in a copolymeriz~tion process in which a catalyst is used . r~;nrJ a bidentate ligand of the type rq~ i in ~P-A-31g083, results in a rrn~ r~hl y lower reaction rate.
When a diluent is used in the process of this invention it is preferred to have a solid particulate material suspended in the diluent before the monomers are contacted with the c~talyst system.
Suitable solid particulate materials are silica, polyethene and a copolymer of carbon monoxide and an ethylenically unsaturated compound, preferably ~ copolymer which is based on the s~me monomer~
~s the copolymer to be prepared. The quantity of the solid particulate material is pref~rably in the range of 0.1-20 g, particularly 0.5-10 g per 100 g diluent.
According to a preferred ~mhr,rl; ' of the process of the invention, a catalyst system is used which is supported on a solid carrier m.aterial.
By using a supported c~tDlyst system of this type, copolymers having a high bulk density are obtained, whereas the use of a supported catalyst system based on a ligand according to EP-A-319083 results in copolymers of lower bulk density.
Suitable solid m~terials include organic compounds, such ~s polymers and resins, in particul~r ion ~ rhAn7~n7 resins, and inorganic compounds such as zeolites and inorganic oxides, e.g.
silica, alumina, tit~nia, zirconia and the like. Inorganic oxides Are preferred c~rrier materials and among these, in particular silica, or a silica r,rnt:~in;n7 oxide-mixture.
The aunt of carrier material to be u~ed for the supported catalyst~ may vary rrn~ r~hly. To a large extent ~he size of the WO 95l29946 ~ 9 2 1 r~.,~, :/01678 _ g _ carrier material ~i7torm~no~ the amount required for an optimal rorfmrr~ of the catalyst.
r- J I are in particular carrier material5 in which the particle size iJ in the range of 0 . 001 to 5 microns, preferably in the range of 0. 005 to 4 microns . The said particle sizes are usually indicated as Dso values, i.e. the size (in microns) whereby 509~ of the particleJ has a particular dlameter. If a particle size range iJ
given, the diameterJ of aubstantially all particles are within the said range. MaterialJ having a Dso of 0. 01 are especially preferred.
If desired, a catalyst system may be uJed, which additionally comprises an organic oxidant. Examples o~ suitable oxidants include quinones such as 1,4-b~-n7Oq~lin~n~, 1,2-n7rllthr~q~1n^n~ and 1,4-n7rhtholq~l; nAno .
The conditions under which the process of the inventlon is performed, include the use of elevated temperatures and pressures, such as between 20 and 200 'C, in particular 30 and 130 C and 1-200 bara, in particular 5-100 bara.
Preferred reaction temperatures are in the range of 70 to 130 C, temperatures in the range of 80 to 100 C being most preferred.
The reaction pressure is preferably selected in the range of 40 to 80 bara, but pressures outsid~ these limits are not precluded.
The invention is illustrated by the following examples.

A carbon monoxide/ethene copolymer was prepared as follows. A
stirred 200 ml autoclave was charged with 90 ml of mcthanol, 1. 58 g of Linear ~lternating carl:~on monoxide/ethene copolymer (obtained in a previous experiment), and a catalyst solution consisting of 10 ml of methanol, 0.0094 mmol of r71l7~ -acetate, 0.188 mmol of fluoboric acid (hôF4) and 0.0104 mmol of 1,2-bis~di(2-methoxy-phenyl ) phosphino] ethane .
The air in the autoclave was displaced by nitrogen (1 bara).
The autoclave was then heated to 90 'C and pre3surized with an equimolar mixture of carbon monoxide and ethene until a pressure of 50 bar was reached. A~-c~r~in~ly, the pol~ ri77t~rm started. During WO 9SI29946 r~ 78 the reaction the pressure was r`-;nt~;n--~ by pressurizing with an equimolar carbon nonoxide/ethene mLxture. After 3 hours the Poli r; 7~ n was terminatcd by depressurization and ..11.3 ~.,...1 coolLng to ambient temperature.
The yield was 26 . S g of copolymer having a bulk density of 220 kg/m3 . The polymerization rate was 8 . 3 kg of copolymer per gram of palladLum and per hour.
liX~MPI.E 2 A cArbon monoxide/ethene copolymer was prepared, substantially as described in Example 1, with the difference that the reactor was pre~surized with a mixture of c~rbon monoxide and ethene in a molar ratlo of 0 . 40 :1 instead of with an equimolar carbon monoxide/ethene mLxture.
The yield was 36.1 g of copolym~r having a bulk density of 315 kg/m3 . The polymerization rate was 11. S kg of copolymer per gram of palladium and per hour.

A carbon monoxide/ethene copolymer was prepared, subst~ntially as described in ~xample 1, with the difference that the reactor was pressurized with a mLxture of carbon monoxide and ethene in a molar rAtio of 1.42:1, instead o~ with an equimolar mixture.
The yield was 25 . 6 g of copolymer having a bulk d~nsity of 230 kg/m3 . The polymerization rate was 8 . 0 kg of copolymer per gram of palladLum and per hour.

A carbon monoxide/ethene copolymer was prepared, substantially as described in Example 1 with the fl; ffPr~'n~-~' that a reaction t~ rA~Ir~ of 85 C, instead of 90 C wzs applied.
The yield was 20.2 g of copolymer having a bulk denaity of l9S kg/m3. The polymerization rate was 6.2 kg of copolymer per gram of palladium and per hour.
EX~MPI.E S
A carbon monoxide/ethene copolymer was pr~pared, substantially as described in Example 1 with the dLfference that the reaction t~-r.~rA1-~ r~ was gS C, instead of 90 C.

q21 W0 95/29946 r~ JI678 .
Th~ yield was 30 . 7 of copolymer having a bulk density of 255 kg/m3 . The polymerization rate was 9 . 7 kg of copolymer per gram of palladium and per hour.
IPLE A ~for r~ cAn, not according to the invention) A carbon monoxide/ethene copolymer was prcpared, sub_tantially as described in Example 1, with the difference that 0.104 mmol of l,3-bisIdi(2 - ' y~ yl)phosphino]propane was us~d, instead of 1,2-bisIdi(2 ~ ' y~ .lyl)phosphino]ethane. The yield was 6.1 g of copolymer having a bulk density of only 70 kg/m3. The pol~ ~ri7:t~An rate was 1.5 kg of copolymer per gram of palladium and per hour.

A car~on monoxide/ethene copolymer was prepared, substantially as described in Example 1, with the ~;ff~r~n~-e that 0.188 mmol of trifluoroacetic acid was used, instead of fluo-boric acid. The yield was 16. 9 g of copolymer having a bulk density of 107 kg/m3 . The polymerization rate was 5.1 kg of copolymer per g of palladium and per hour.
EXAMPLE B (for ~ ,~r~CAn~ not according to the invention) A carbon monoxide/ethene copolymer was prepared, substantially as described in Example 6, with the difference that 0.104 mmol of 1,3-bis[di(2 h.~LI.~IAy~ .lyl)phosphino]prop~ne was used instead of 1,2-bis[di (2-methoxyphenyl)phosphino]ethane.
The reaction had to be t.ormi n~t~ after l h, because fluffy product was formed, hindering proper mixing of the reactor contents.
The yield was 8.7 g of copolymer having a bulk density of 80 kg/m3.
The polymerization rate was 8.1 kg of copolymer/g palladium and per hour .

A carbon monoxide/ethene copolymer was prepared as follows. A
stirred 300 ml autoclave was charged with 100 ml of methanol. Air was removed by rr~C?lri7~n~ with carbon monoxide and 5'' . 'ly the pressure was increased to 50 bar by pr~sur;7ing with a mixture of carbon monoxide and ethene in a molar ratio of 1.5:1.
The temperature was raised to 96 C and s"h~? ly a catalyst solution was in~ected with the carbon monoxide stream at an 21 8~921 WO9~/29946 T~~ 1678 additional pre~sure of 5 bar. The catalyst solution con~isted of 0.01 mmol of palladium (II) acetate 0.012 mmol of 1,2-bis[di(2-yyllo.~yl)phosphino]ethane and 0.2 mmol of fluoboric acid in 10 ml of methanol. Accordingly, the reaction ~tarted and waa t~rm;r.~t~ after 1 hour.
The yield of copolymer was 13 g. The pol~ i 7~t; Gn rate was 13 kg of copolymer per gram of palladium and per hour. The Limiting Vi~coaity Number (LVN) of the copolymer wzs 0 . 7 ml/g.

A carbon monoYide/ethene copolymer was prep2red, aubstantially as described in Example 7, with the difference that a mixture of 50 ml of tertiary butanol and 50 ml of methanol was used, instead of 100 ml of m~thanol.
The yield of copolymer was 10 g. The polymeri_~tion rate was still 10 kg of copolymer per gram of palladium and per hour. The LVN
of the copolymer had increased to 4 . 5 dl/g.
In a similar ~ r-rl ', in which 100 ml of tertiary butanol ~nd no methanol was used as diluent, the pol~ ri7:~ti<~n rate was 1.5 kg of copolymer per gram of palladium and per hour.
EXAMPLE C (for . rr~ r not according to the invention) P. copolymer of carbon monoxide and ethene was prepared, 51~hct~nt;:111y as descrlbed in Example 7, with the difference th~t 0 . 012 mmol of 1, 3-bis ~di- (2-methoxyphenyl ) phosphino] propane was used instead of 1,2-bis[di(2-methoxyphenyl)phosphino]ethane. The copolymer obtained had a LVN of 2. 0 dl/g and was produced with a polymerization rate of 10 kg of copolymer per gram of palladium ~nd per hour.
In a similar ~.Yr..rl t, whereby as diluent 100 ml of tertiary butanol and no methanol was used, the polymerization rate waa 0 . 5 kg of copolymer per gram of palladium and per hour.
In another similar ~.~.r~.ri L, whereby as diluent 50 ml of tertiary butanol and 50 ml of methanol was used 5 g of copolymer was obtained in 2 hours . The LVN of the copolymer was 6. 0 dl/g, but the polymerization r~lte had dropped from 10 to 2.5 kg of copolymer per gram of palladium and per hour.

W0 95l29946 . ~ '78 EX~MPLE 9 A copolymer of carbon noxide and ethene was prepared as follows. A 300 ml autoclave wzs charged with 5 g of CLA 27252 (a ~ rriAlly available silica having a pllrticle size (Dso) of 3.5 micron), p.. 11i.~1; II-acetate(l.S mg Pd), 1,2-bis[di(2-y~ yl)phosphino]ethan~ and fluoboric acid-dimethylether such that the molar ratio palladium compound: bidentate ligand: acid anion was 1.0:1.1:5.0 end lSO ml of methanol. Air was removed and the autoclave was pressurized with an equimolar mixture of carbon 0 noxide and ethene up to a pressure of SO bara. The t~ -rAr--re of the contents of the autoclave was raised to 90 C, whereupon the polymerization started. The re~ction was terminated after a runtime of S hours.
The polymerization rate was 2.1 kg of copolymer per g of palladium and per hour. The bulk density of the copolymer was 2 9 0 kg/m3 .
EX~MPLE D (for r; enn~ not according to the invention) A copolymer of carbon monoxide and ethene was prepared, ~ubstantially as described in Example 9, with the difference that 1,3-bis[di(2-methoxyphenyl)phosphino]propane was used instead of 1,2-bis[di(2-methoxyphenyl)phosphino3ethane. The polymerization rate was 8.2 kg of copolymer per g of palladium and per hour. The bulk density of the copolymer was 123 kg/m3.

A copolymer of carbon monoxide and ethene was prepared, substantially as described in Example 9, with the difference that Organo-silicasol (a com~ rcially available silica with a particle size (D50) of 0.01 micron1 was used instead of CLA-27252.
The polymerization rate was S . 8 kg of copolymer per g of palladium and per hour. The bulk density of the copolym~r was 320 g/m3.
EXAMPLE E (for ri ern not according to the invention) A carbon noxide/ethene copolymer was prepared, substantially as described in Example 10, with the difference that 1,3-bi~[di(2-meth~".! pll_.lyl)phosphino3propane was used instead of 1,2-bi~[di(2-WO 9~/29946 2 1 8 8 9 2 1 P~l/~ '78 y~ yl)phO phino]ethane. The polymerization rate was 9.6 kg of copolymer per g of palladium and per hour. The bulk density of the copolymer was 120 kg/m3.

A c~rbon monoxide/ethene copolymer was prepared, ~ubstantially ~s described in Example 10, with the difference that trifluoro-acetic ~cid was uaed instead of fluoboric acid-dimethylether. The polymerizAtion rate was 5.1 kg of copolymer per g of palladium and per hour. The bulk density of the copolymer was 370 kg~m3.
EXAMPLE F (for . -ri<^n, not according to the invention) A carbon monoxide/ethene copolymer was prepared, 5~h~t:~nt;:~11y as described in Example 11, with the difference that 1,3-bis[di(2-Lll~,Ay~ .lyl)phosphino]propane was used instead of 1,2-bis[di(2-Lll~.y~}~ yl ) phosphino ] e thane .
The polymerizAtion r~te was 8 . 3 kg of copolymer per g of pAlladium and per hour. The l~ulk density of the copolymer was 127 kg/m3.

Claims (16)

C L A I M S

1. A catalyst system suitable for the copolymerization of carbon monoxide with an ethylenically unsaturated compound which catalyst system is based on (a) a source of palladium cations, and (b) a bidentate ligand of the general formula R1R2P-CH2-CH2-PR3R4 (I) wherein R1 represents a phenyl group substituted with a polar group at one or both ortho-positions and/or the para-position with respect to the phosphorus atom to which the said phenyl group is linked, and R2, R3 and R4 independently represent a substituted or non-substituted hydrocarbyl group, on the understanding that when the catalyst system is based on a ligand mixture which ligand mixture comprises a bidentate ligand of the general formula (I) wherein each of R1, R2, R3 and R4 carries an alkoxy group at an ortho-position with respect to the phosphorus atom and a bidentate ligand of the general formula R5R6P-X2-PR7R8 wherein R5, R6, R7 and R8 independently represent aryl groups of up to 10 carbon atoms which are free of alkoxy substituents and X2 represents a divalent hydrocarbyl group having 2-4 carbon atoms in the bridge and which ligand mixture is present in a quantity of 0.5-2 mole per gram atom of palladium, and the catalyst system is in addition based on an anion of an acid having a pKa of less than 4 in a quantity of 0.5-50 equivalents per gram atom palladium, the quantity of the bidentate ligand of the general formula (I) in the ligand mixture is at least 95 %-mole, relative to the total quantity of the two types of bidentate ligands.

2. A catalyst system suitable for the copolymerization of carbon monoxide with an ethylenically unsaturated compound which catalyst system is based on (a) a source of palladium cations, and (b) a bidentate ligand of the general formula (I) wherein R1 represents a phenyl group substituted with a polar group at one or both ortho-positions and/or the para-position with respect to the phosphorus atom to which the said phenyl group is linked, and R2, R3 and R4 independently represent a substituted or non-substituted hydrocarbyl group, and which is supported on a solid carrier, such as silica, preferably having a particle size in the range of 0.005 to 4 microns.

3. A catalyst system as claimed in claim 1 or 2, characterized that it is based in addition on a source of anions, in particular an acid with a pKa of less than 2, more in particular tetrafluoboric acid.

4. A catalyst system suitable for the copolymerization of carbon monoxide with an ethylenically unsaturated compound which catalyst system is based on (a) a source of palladium cations, (b) a bidentate ligand of the general formula (I) wherein R1 represents a phenyl group substituted with a polar group at one or both ortho-positions and/or the para-position with respect to the phosphorus atom to which the said phenyl group is linked, and R2, R3 and R4 independently represent a substituted or non-substituted hydrocarbyl group, and (c) a boron containing component.

5. A catalyst system as claimed in claim 4, characterized that the boron containing component is a Lewis acid, a protic acid or a salt, in particular a protic acid which is tetrafluoboric acid.

6. A catalyst system as claimed in any one of claims 1-5, characterized in that, as regards (b), it is based on a bidentate ligand of the formula (I), wherein R1 represents a phenyl group substituted at an ortho-position with respect to the phosphorus atom to which the phenyl group is linked, by a C1-C4 alkoxy group, and wherein R1 represents in particular an ortho-methoxyphenyl group.

7. A catalyst system as claimed in any one of claims 1-6, characterized in that in the bidentate ligand of formula (I) each of R2, R3 and R4 have the same meaning as R1.

8. A catalyst system as claimed in claim 7, characterized in that in the bidentate ligand of formula (I) is 1,2-bis[di(2-methoxy-phenyl)phosphino] ethane.

9. A catalyst system as claimed in any one of claims 1-8, characterized in that, as regards (a), it is based on a palladium salt of a carboxylic acid, in particular palladium II-acetate.

10. A catalyst system as claimed in any one of claims 3-9, characterized that the amount of bidentate ligand of formula (I) is selected in the range of 0.75 to 1.5 moles per gram atom of palladium, and in that the amount of the source of anions or the boron containing component, as the case may be, is selected in the range of 1 to 25 moles per gram atom of palladium.

11. A process for the preparation of copolymers of carbon monoxide with an ethylenically unsaturated compound comprising reacting the monomers in the presence of a catalyst system as claimed in any one of claims 1-10.

12. A process as claimed in claim 11, characterized in that the amount of catalyst is selected such that per mole of ethylenically unsaturated compound to be copolymerized, 10-7 to 10-2 gram atom of palladium is present, in that the molar ratio between carbon monoxide relative to ethylenically unsaturated compound(s) is in the range of 1.5:1 to 1:1.5, and in that the copolymerization is carried out a temperature in the range of 30 to 130 °C and a pressure of 50-100 bara.

13. A process as claimed in claim 11 or 12, characterized in that as ethylenically unsaturated compound ethene is used.

14. A process as claimed in any one of claims 11-13, characterized in that the copolymerization is carried out in the presence of a diluent in which the copolymers are insoluble or virtually insoluble, in particular an organic protic liquid.

15. A process as claimed in claim 14, characterized in that as diluent a primary alcohol having at most 4 carbon atoms per molecule is used, in particular methanol.

16. A process for the preparation of copolymers of carbon monoxide with an ethylenically unsaturated compound comprising reacting the monomers in the presence of a suitable catalyst system which is based on (a) a source of palladium cations, and (b) a bidentate ligand of the general formula (I) wherein R1 represents a phenyl group substituted with a polar group at one or both ortho-positions and/or the para-position with respect to the phosphorus atom to which the said phenyl group is linked, and R, R3 and R4 independently represent a substituted or non-substituted hydrocarbyl group, and using as a diluent a primary alcohol having at most 4 carbon atoms per molecule is used, in particular methanol, in the further presence of a tertiary alcohol having at most 10 carbon atoms per molecule, in particular tertiary butanol, the molar ratio between the primary alcohol and the tertiary alcohol preferably being in the range of 30:70 to 70:30.