RU2383556C2 - Method of producing norbornene addition polymers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: described is a method of producing norbornene addition polymers (bicycle[2.2.1]heptene-2)through polymerisation of norbornene in the presence of a catalyst system obtained by reacting a palladium cationic complex in an organic solvent and etharate of boron trifluoride of formula BF₃OEt₂, distinguished by that the palladium complex used is tetrafluoroborate acetylacetonatobis(triarylphosphine) palladium with general formula [(Acac)Pd(PR₃)₂]BF₄, where Acac is acetylacetonate, where R=o-tolyl, n - tolyl, phenyl. The process is carried out in molar ratio of boron to palladium B:Pd=5:1-40:1 and temperature 15-70°C.

EFFECT: increased efficiency of norbornene polymerisation process through increased catalyst activity.

4 tbl, 18 ex

Description

The invention relates to the field of production of norbornene additive polymers (bicyclo [2.2.1] heptene-2) under the action of catalytic systems based on cationic complexes of palladium and boron trifluoride etherate. Additive polymerization proceeds with the opening of a double bond and leads to polymers containing unchanged cyclic structures in the main chain. Such polymers are characterized by good thermal and chemical stability, amorphous properties, high transparency in the IR, visible and UV regions, low refractive index, narrow decomposition temperature, and low dielectric coefficient. This makes them promising for the production of coatings in electronics, telecommunications materials, optical lenses, substrates for plastic displays, photoresistors, dielectrics for semiconductors.

A known method of producing additive polymers of norbornene (NB) under the action of palladium catalysts / Patent US 5468819, C08F 4/70; C08F 4/30; C08F 4/42; 1995 / through the use of single-component palladium catalysts consisting exclusively of organic palladium cationic complexes with bulky counterions.

A known method of producing additive polymers of norbornene under the action of palladium catalysts / Patent EP 0445755, C08F 4/602; C08F 4/60; C08F 4/6192, 1991 /, by using neutral palladium complexes in combination with methylaluminoxane (MAO), triethylaluminium (AlEt ₃ ) or triisobutylaluminum (Al (i-Bu) ₃ ).

A known method of producing additive polymers of norbornene under the action of palladium catalysts / Patent US 6031058, C08F 4/605; C08F 4/606; C08F 32/08; C08F 4/00; C08F 32/00, 2000 / by using neutral palladium complexes in combination with tris (pentafluorophenyl) borate (B (C ₆ F ₅ ) ₃ ) and aluminum triethyl.

A known method of producing additive polymers of norbornene under the action of palladium catalysts / ADHennis, JDPolley, GSLong, A.Sen, D.Yandulov, J. Lipian, GMBenedikt, LFRhodes, J.Huffman, Organometallics, 20, 2001, 2802-2812 / using catalysts based on (1,5-cyclooctadiene) Pd (1 (СН ₃ ) Cl in combination with PR ₃ and Na ⁺ [(3,5- (CF ₃ ) ₂ С ₆ Н ₃ ) ₄ В] ^- .

The disadvantages of such catalytic systems include the use of expensive, unstable organometallic complexes of palladium, organoboron and aluminum compounds.

The closest known solution to a similar problem in technical essence is a method for producing a catalyst for the polymerization of norbornene by reacting bis (acetylacetonato) palladium with boron trifluoride etherate (G. Myagmarsuren, Ki-Soo Lee, O-Yong Jeong, Son-Ki Ihm. Polymer, 45, 2004, 3227-3232).

Such catalytic systems are characterized by relatively low catalyst activity. So, during the polymerization of norbornene in the presence of the Pd (Acac) ₂ +25 BF ₃ OEt ₂ catalyst system, where Acac is acetylacetonate, with an HB: Pd ratio of 5600: 1, the average activity does not exceed 20,000 kg of norbornene per mole of Pd per hour.

The objective of the invention is to provide a method that improves the efficiency of the polymerization of norbornene by increasing the activity of the catalyst.

The problem is achieved in that in the method for producing additive norbornene polymers (bicyclo [2.2.1] hepten-2) by polymerization of norbornene in the presence of a catalytic system obtained by reacting a cationic palladium complex in an organic solvent and boron trifluoride ether of the formula BF ₃ OEt ₂ , in The palladium complex used is acetylacetonatobis tetrafluoroborate (triarylphosphine) palladium of the general formula [(Acac) Pd (PR ₃ ) ₂ ] BF ₄ , where Acac is acetylacetonate, where R = o-tolyl, n is tolyl, phenyl, and the process is carried out at a molar rel enii boron to palladium B: Pd = 5: 1-40: 1, and a temperature of 15-70 ° C.

The method consists in the polymerization of norbornene by using a catalyst obtained by the interaction of a cationic complex of palladium and boron trifluoride etherate in an organic solvent in the presence of norbornene. The components are mixed in the following order: a solution of the cationic complex of palladium in an organic solvent, for example nitromethane, is added to a solution of norbornene in an organic solvent, for example, toluene, then boron trifluoride etherate is introduced. Optimum process conditions: the molar ratio of boron to palladium, B: Pd = 5: 1-40: 1, preferably B: Pd = 25: 1, temperature 15-70 ° C, preferably 60 ° C.

The structure of the obtained polynorbornene was confirmed by NMR and IR spectroscopy. NMR and IR spectroscopy data showed that the structure corresponds to the additive polymer. In the IR spectrum, no bands are observed in the region of 1620-1680 cm ^-1 from double bonds, but there are strong absorption bands in the region of 1452-1474 cm ^-1 from deformation vibrations of the bridging -CH ₂ - group of the norbornene ring. The assignment of NMR spectral signals is done according to the following numbering of carbon atoms:

According to ¹³ C NMR spectroscopy with DEPT editing, the resonance peaks of non-bridging CH ₂ groups (C5 and C6) appear at 30-33 ppm. Bridged CH ₂ groups (C7) are characterized by signals at 36-37 ppm. CH groups (C1, C2, C3 and C4) are manifested by signals at 20-36 ppm. The presence of resonances at 20-24 ppm indicates endo-, exoconfiguration of the polymer chain.

The following examples illustrate the present invention.

EXAMPLE 1

A 5 ml solution of norbornene in toluene containing 3.6 g (0.038 mol) of norbornene was loaded into a 10 ml flask pre-evacuated and filled with an inert gas (nitrogen or argon). The solution was thermostated at 60 ° C for 15 min, then a solution of the catalyst [(Acac) Pd (PPh ₃ ) ₂ ] BF ₄ in nitromethane (1 ml containing 1 μmol Pd) was added to it. The polymerization was initiated by the introduction of BF ₃ OEt ₂ (3.17 μl, 25 μmol). The molar ratio of NB: B: Pd = 38000: 25: 1, reaction time 30 min. The reaction was interrupted by the addition of acidified (HCl, 3 wt.%) Ethanol, the precipitated polymer was washed three times with ethanol and dried in vacuum (1 mmHg) at 60 ° C for 6 h. The polymer yield was 2.8 g or 2800 kg of product per 1 mol of Pd. The intrinsic viscosity [η] in 1,2,4-trichlorobenzene at 25 ° C was 0.68 dL / g. Glass transition temperature 310 ° C. The decomposition temperature is 410 ° C.

EXAMPLES 2-5

These examples illustrate the effect of the B: Pd molar ratio on the yield and intrinsic viscosity of polynorbornene. The reactions were carried out analogously to example 1. The results of the experiments are combined in table 1.

Table 1
The effect of the molar ratio B: Pd on the yield and intrinsic viscosity of polynorbornene in the presence of the system: [(Acac) Pd (PPh ₃ ) ₂ ] BF ₄ + nBF ₃ OEt ₂ (temperature 60 ° С, reaction time 30 min, 3.6 g NB, total volume 6 ml) No. B: Pd rel. HB: Pd rel. The amount of catalyst, 10 ⁶ mol Yield, g Conversion, kg NB / (mol, Pd) [η], dL / g 2 5 38000 one 0.6 600 0.49 3 10 38000 one 0.9 900 0.53 four fifteen 38000 one 1.7 1700 0.63 5 40 38000 one 3.0 3000 0.49

EXAMPLES 6-8

These examples illustrate the effect of the nature of phosphine ligands on the yield and intrinsic viscosity of polynorbornene. The polymerization was carried out analogously to example 1, the results of the experiments are presented in table 2.

table 2
The effect of the nature of phosphine ligands on the yield and intrinsic viscosity of polynorbornene in the presence of the system: [(Acac) Pd (PR ₃ ) ₂ ] BF ₄ + 25BF ₃ OEt ₂ (temperature 60 ° C, reaction time 30 min, 3.6 g NB, total volume 6 ml) No. R HB: Pd rel. The amount of catalyst, 10 ⁶ mol Yield, g Conversion, kg NB / (mol Pd) [η] dL / g 6 n-tolyl 38000 one 2.7 2700 0.63 7 o Tolil 38000 one 2.1 2100 0.50 8 Phenyl 38000 one 2.8 2800 0.68

EXAMPLES 9-12

These examples illustrate the effect of the amount of catalyst [(Acac) Pd (PPh ₃ ) ₂ ] BF ₄ on the yield and intrinsic viscosity of polynorbornene at a constant concentration of norbornene. The reactions were carried out analogously to example 1, the results are presented in table 3. In example 12, the conversion is 600 kg of norbornene per mole of Pd for 6 s, which corresponds to an average activity of 360,000 kg of norbornene per mole of Pd per hour.

Table 3
Effect of the amount of [(Acac) Pd (PPh ₃ ) ₂ ] BF ₄ on the yield and intrinsic viscosity of polynorbornene in the presence of the system: [(Acac) Pd (PPh ₃ ) ₂ ] BF ₄ + 25BF ₃ OEt ₂ (temperature 60 ° С, 3.6 g NB, total volume 6 ml) No. Reaction time, min HB: Pd rel. The amount of catalyst, 10 ⁶ mol Yield, g Conversion, kg NB / (mol Pd) [η], dL / g 9 thirty 38000 one 2.8 2800 0.68 10 10 19000 2 3.5 1750 0.63 eleven 3 12600 3 3.1 1000 0.46 12 0.1 7600 5 3.0 600 0.37

EXAMPLES 13-18

These examples illustrate the effect of the reaction temperature on the yield and intrinsic viscosity of polynorbornene. The procedure for conducting experiments is similar to example 1. The results of the experiments are shown in table 4.

Table 4
The effect of the reaction temperature on the yield and intrinsic viscosity of polynorbornene in the presence of the system [(Acac) Pd (PPh ₃ ) ₂ ] BF ₄ +25 BF ₃ OEt ₂ (reaction time 30 min, 3.6 g NB, total volume 6 ml) No. T, ° С HB: Pd rel. The amount of catalyst, 10 ⁶ mol Yield, g Conversion, kg NB / (mol Pd) [η], dL / g 13 twenty* 38000 one 0.4 400 - fourteen thirty* 38000 one one 1000 - fifteen 40 38000 one 1.2 1200 0.98 16 fifty 38000 one 1.7 1700 0.80 17 60 38000 one 2.8 2800 0.68 eighteen 70 38000 one 2.3 2300 0.50 * Determination of viscosity is difficult due to poor solubility of polymer samples in 1,2,4-trichlorobenzene

The proposed method allows to increase the efficiency of the polymerization of norbornene, to reduce its cost.

Claims (1)

A method of producing additive norbornene polymers (bicyclo [2.2.1] heptene-2) by polymerization of norbornene in the presence of a catalytic system obtained by reacting a cationic palladium complex in an organic solvent and boron trifluoride etherate of the formula BF ₃ OEt ₂ , characterized in that as a palladium complex use tetrafluoroborate acetylacetonatobis (triarylphosphine) palladium of the general formula [(Acac) Pd (PR ₃ ) ₂ ] BF ₄ , where Acac is acetylacetonate, where R = o-tolyl, n-tolyl, phenyl, and the process is carried out with a molar ratio of boron to Palladium B: Pd = 5: 1-40: 1, and a temperature of 15-70 ° C.