RU2315064C1 - Method for preparing catalyst for polymerization of norbornene - Google Patents

Abstract

FIELD: catalysts, chemical technology.

SUBSTANCE: invention relates to a method for preparing a catalyst used in additive polymerization of norbornene to polynorbornenes. Invention describes a method for preparing a catalyst for additive polymerization of norbornene involving interaction of palladium (II) compound with boron trifluoride etherate in toluene medium as a solvent. Components are mixed in the following order: palladium compound solution is added to norbornene solution in organic solvent followed by addition of boron trifluoride etherate. Optimal conditions for the process are the following: the molar ratio boron to palladium, B : Pd = (5-1):(60-1), temperature 15-60°C. Invention provides enhancing effectiveness of the polymerization process. Synthesized compounds are used in producing cover in electronics, television-communication materials, optical lens, substrates for plastic displays, photoresistors for producing chips and displays, dielectrics for semiconductors.

EFFECT: improved method of synthesis.

1 cl, 6 tbl, 27 ex

Description

The present invention relates to the field of producing a catalyst for the addition polymerization of norbornene (bicyclo [2.2.1] hepten-2).

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 for the production of chips and displays, dielectrics for semiconductors.

Known catalysts for the additive polymerization of norbornene (NB): one-component palladium catalysts consisting exclusively of palladium-organic cationic complexes with bulky counterions (Patent US 5468819, B.L. C 08 F 4/30; C 08 F 32/08; C 08 F 4 / 00; C 08 F 32/00; (IPC1-7): C 08 F 4/80; C 08 F 4/76; C 08 F 4/78, 1995).

Known neutral complexes of palladium in combination with methylaluminoxane (MAO), triethylaluminum (AlEt ₃ ) or triisobutylaluminum (Al (i-Bu) ₃ ) (Patent EP No. 0445755, C 08 G 61/08; C 08 G 61/00; ( IPC1-7): C 08 G 61/08, 1991).

Known neutral complexes of palladium in combination with tris (pentafluorophenyl) borate (B (C ₆ F ₅ ) ₃ ) without (US Patent No. 6031058, C 08 F 4/605; C 08 F 4/606; C 08 F 32/08; C 08 F 4/00; C 08 F 32/00, 2000) or with triethyl aluminum (P. G. Lassahn, C. Janiak, Jae-Seung Oh, Macromol. Rapid. Commun., 23, 2002, 16- twenty); catalysts based on (1,5-cyclooctadiene) Pd (CH ₃ ) Cl in combination with PR ₃ and Na ⁺ [(3,5- (CF ₃ ) ₂ C ₆ H ₃ ) ₄ B] ^- (ADHennis, JDPolley, GSLong , A. Sen, D. Yandulov, J. Lipian, GM Benedikt, LF Rhodes, J. Huffman, Organometallics, 20, 2001, 2802-2812).

The disadvantages of such catalytic systems include the use of expensive unstable organometallic complexes of palladium, organo-boron 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 (Patent EP No. 0837079, C 08 F 4/60; C 08 F 4/80; C 08 F 32/00; C 08 F 210/00; C 08 F 4/00; C 08 F 32/00; C 08 F 210/00, 1998) by reacting organometallic palladium (II) compounds with tris (pentafluorophenyl) borate or HB acid [C ₆ H ₃ (CF ₃ ) ₂ ] _four

The disadvantage of this method is its low efficiency, since such catalytic systems are characterized by a relatively low conversion of norbornene. Thus, during the polymerization of norbornene in the presence of the PdPh (Ph ₂ PCHCPhO) (PPh ₃ ) / НВ [С ₆ Н ₃ (CF ₃ ) ₂ ] ₄ catalyst system at 80 ° С and the ratio HB: Pd = 1000: 1 for an hour, the conversion is 51%, i.e. the activity is 480.3 kg kg norbornene per mole of Pd per hour. Under the same conditions, the PdPh (Ph ₂ PCHCPhO) (PPh ₃ ) / В (С ₆ F ₅ ) ₃ catalyst system leads to the formation of polymer traces.

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

The problem is achieved in that in the method for producing a catalyst for the polymerization of norbornene based on divalent palladium compounds, palladium carboxylates or β-diketonates of the general formula Pd (OCOR) _{2 are used} as OCOR, where OCOR is acetate, benzoate, propionate, heptanoate, stearate or Pd (RC (O) CH (O) CR ') ₂ , (RC (O) CH (O) CR') - acetylacetonate, in combination with boron trifluoride etherate of the formula BF ₃ OEt ₂ , and the process is carried out at a molar ratio boron to palladium B: Pd = 5: 1-60: 1 and a temperature of 15-60 ° C.

The method is as follows.

The method consists in reacting a palladium compound and boron trifluoride etherate in an organic solvent, for example toluene. The components are mixed in the following order: a solution of palladium (II) compound in an organic solvent is added to a solution of norbornene in an organic solvent, then boron trifluoride etherate is introduced. Optimum process conditions: the molar ratio of boron to palladium, B: Pd = 5: 1-60: 1, at a temperature of 15-60 ° C.

The molecular weights of the polymers were determined by gel permeation chromatography (GPC), the standard was polystyrene, the solvent was 1,2,4-trichlorobenzene, and the temperature was 135 ° 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 ¹ H NMR spectrum, there are no bands from protons of double bonds. The IR spectrum also does not show bands 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 bridging CH ₂ groups of the norbornene ring. The assignment of NMR spectral signals is made according to the following numbering of carbon atoms:

According to ¹³ C NMR spectroscopy, the resonance peaks of non-bridging CH ₂ groups (C5 and C6) appear at 28-34 ppm. Bridge CH ₂ groups (C7) are characterized by signals at 34-38 ppm. Nodal CH groups (C1 and C4) are manifested by signals at 38-45 ppm. Signals at 45-55 ppm refer to CH groups (C2 and C3) of the polymer backbone. Moreover, the absence of resonances at 20-24 ppm indicates the exo configuration of the polymer chain. The following examples illustrate the present invention.

EXAMPLE 1

6 ml of a solution of norbornene in toluene containing 4.71 g (0.05 mol) of norbornene was charged into a 10 ml flask pre-evacuated and filled with an inert gas (nitrogen or argon). The solution was thermostated at 25 ° C for 15 min, then a solution of Pd (OAc) ₂ catalyst in toluene (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 NB: B: Pd = 50,000: 25: 1, the reaction time is 30 minutes The reaction was interrupted by the addition of acidified (HCl, 3 wt.%) Ethanol, the precipitated polymer was washed with ethanol three times and dried in vacuum (1 mmHg) at 80 ° C for 6 h. The polymer yield was 1.59 g or 1590 kg of product per mole of Pd. The intrinsic viscosity in chlorobenzene at 25 ° C was 1.29 dL / g. The molecular weights determined by GPC were 179,100 g / mol (M _w ) and 83,700 g / mol (M _n ). Glass transition temperature 258 ° C.

EXAMPLES 2-7

These examples illustrate the effect of the B: Pd 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.
Effect of the B: Pd ratio on the yield and intrinsic viscosity of polynorbornene in the presence of the Pd (OAc) ₂ + nBF ₃ OEt _{2 system} (25 ° C, 30 min, 4.71 g NB, toluene solvent, total volume 7 ml) B: Pd HB: Pd Katal. Exit Conversion [η] No. Rel. rel. 10 ⁶ mol g kg NB / (mol Pd) dl / g 2 5 50,000 one 0.20 200 0.43 3 10 50,000 one 0.58 580 0.68 four fifteen 50,000 one 1.28 1280 1.18 5 twenty 50,000 one 1.50 1500 1.24 6 40 50,000 one 1.56 1560 1.40 7 60 50,000 one 1.53 1530 1.34

EXAMPLES 8-11

These examples illustrate the effect of the nature of carboxylate 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.
Effect of the nature of carboxylate ligands on the yield and intrinsic viscosity of polynorbornene in the presence of the PdL ₂ + 25BF ₃ OEt _{2 system} (25 ° C, 30 min, 4.71 g NB, toluene solvent, total volume 7 ml) L HB: Pd Katal. Exit Conversion [η] No. C _n rel. 10 ⁶ mol g kg NB / (mol Pd) dl / g 8 Benzoate, C ₇ 50,000 one 1.49 1490 1.09 9 Propionate, C ₃ 50,000 one 1.52 1520 1.32 10 Heptanoate, C ₇ 50,000 one 1.63 1630 1.36 eleven Stearate, C ₁₈ 50,000 one 1.61 1610 1.68

EXAMPLES 12-15.

These examples illustrate the effect of the HB: Pd ratio on the yield and intrinsic viscosity of polynorbornene. The experimental procedure is similar to Example 1, the amount of monomer is varied with a constant amount of palladium. The total reaction volume was 7 ml. The results are summarized in Table 3. In Example 20, the total reaction volume was 13 ml.

Table 3.
Effect of the NB: Pd ratio on the yield and intrinsic viscosity of polynorbornene in the presence of the Pd (OAc) ₂ + 25BF ₃ OEt _{2 system} (25 ° C, 30 min, toluene solvent, total volume 7 ml) HB: Pd Katal. Exit Conversion [η] No. rel. 10 ⁶ mol g kg NB / (mol Pd) dl / g 12 25,000 one 0.20 200 0.43 13 37500 one 0.58 580 0.68 fourteen 67500 one 1.50 1500 1.24 fifteen 1,000,000 one 1.59 1590 1.29

EXAMPLES 16-20.

These examples illustrate the effect of the amount of Pd (OAc) ₂ catalyst 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 4. In example 20, the conversion is 428 kg of norbornene per mole of Pd in less than 10 s, which corresponds to an activity of more than 154 100 kg of norbornene per mole of Pd per hour.

Table 4.
Effect of the amount of Pd (OAc) ₂ on the yield and intrinsic viscosity of polynorbornene in the presence of the Pd (OAc) ₂ + 25BF ₃ OEt _{2 system} (25 ° С, 30 min, 4.71 g NB, toluene solvent, total volume 7 ml) [Pd] HB: Pd Time Exit Conversion [η] No. 10 ⁶ mol rel. min g kg NB / (mol Pd) dl / g 16 0.5 100,000 thirty 1.11 2220 1.36 17 2.0 25,000 thirty 2.47 1235 1.23 eighteen 3.0 16700 thirty 4.70 1566 0.69 19 5.0 10,000 one 3.11 622 1.1 twenty 10.0 5000 <10 s 4.28 428 0.56

EXAMPLES 21-25

These examples illustrate the effect of reaction temperature on the yield and intrinsic viscosity of polynorbornene using a Pd (OAc) ₂ catalyst. The procedure for conducting experiments is similar to example 1. The results of the experiments are shown in Table 5.

Table 5.
Effect of reaction temperature on the yield and intrinsic viscosity of polynorbornene in the presence of the Pd (OAc) ₂ + 25BF ₃ OEt _{2 system} (25 ° С, 30 min, 4.71 g NB, toluene solvent, total volume 7 ml) Pace. Katal Exit Conversion [η] No. ° C 10 ⁶ mol g kg NB / (mol Pd) dl / g 21 fifteen one 1.67 1670 1.37 22 35 one 1.45 1450 1.10 23 45 one 1.19 1190 0.88 24 55 one 0.95 950 0.28 25 65 one 0.82 820 0.19

EXAMPLE 26

This example illustrates the use of the Pd (acac) ₂ catalyst in the polymerization of norbornene. 15 ml of a solution of norbornene in toluene containing 10.52 g (0.112 mol) of norbornene and 14 ml of toluene were loaded into a 50 ml flask pre-evacuated and filled with an inert gas (nitrogen or argon). The solution was thermostated at 25 ° C for 15 min, then a solution of Pd (acac) ₂ catalyst in toluene (1 ml containing 5 μmol Pd) was added to it. Polymerization was initiated by the introduction of BF ₃ OEt ₂ (15.8 μl, 0.125 mmol). The molar ratio NB: B: Pd = 22350: 25: 1, reaction time 30 minutes The reaction was interrupted by the addition of acidified (HCl, 3 wt.%) Ethanol, the precipitated polymer was washed with ethanol 3 times and dried in vacuum (1 mmHg) at 80 ° C for 6 h. The polymer yield was 2.97 g or 594 kg of product per mole of Pd in 30 min. The intrinsic viscosity in 1,2,4-trichlorobenzene at 25 ° C is 1.25 dL / g. The molecular weights determined by GPC were 179,100 g / mol (M _w ) and 83,700 g / mol (M _n ). Glass transition temperature 363 ° C.

EXAMPLE 27

The polymerization was carried out analogously to example 26. Used 20 μmol Pd (acac) ₂ and 50 mmol BF ₃ OEt ₂ (ratio NB: B: Pd = 5600: 25: 1). 6.74 g of polynorbornene were obtained in 1 min. This conversion corresponds to an activity of 20 220 kg of norbornene per mole of Pd per hour. The intrinsic viscosity is 0.62 dL / g in 1,2,4-trichlorobenzene at 25 ° C. The molecular weights were 76.300 g / mol (M _w ) and 50.400 g / mol (M _n ). Glass transition temperature 358 ° C.

The data of gel permeation chromatography and thermal analyzes of polymer samples with different values of the characteristic viscosity obtained in the presence of the Pd (OAc) ₂ / BF ₃ OEt _{2 system} are summarized in Table 6.

Table 6.
GPC and thermal analyzes of polymer samples obtained in the presence of the Pd (OAc) ₂ + 25BF ₃ OEt _{2 system} (30 min, 4.71 g NB, toluene solvent, total volume 7 ml)

mole

1.40 * 25 1.0 thirty 293 2.27 324 262 800 1.29 25 1.0 thirty 179 2.14 324 258 one hundred 1.10 25 5.0 one 141 2.72 319 252 900 0.56 25 10.0 <10 s 92900 3.02 317 235 1.19 45 1.0 thirty 174 3.10 313 250 900 0.19 65 1.0 thirty 77700 3.51 313 240 * B / Pd = 40

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

Claims (1)

A method of producing a catalyst for the polymerization of norbornene based on divalent palladium compounds, characterized in that palladium carboxylates or β-diketonates of the general formula Pd (OCOR) ₂ are used as the compounds of divalent palladium, where OCOR is acetate, benzoate, propionate, heptanoate, stearate, or Pd (RC (O) CH (O) CR ') ₂ , (RC (O) CH (O) CR') - acetylacetonate, in combination with boron trifluoride etherate of the formula BF ₃ OEt ₂ , and the process is carried out at a molar ratio of boron to palladium B: Pd = 5: 1-60: 1 and a temperature of 15-60 ° C.