POLYBUTADIENE, PRODUCTION AND USE THEREOF

Abstract

The invention relates to polybutadiene, which contains the monomer units derived from 1,3-butadiene having a vinyl double bond in a proportion of 25 to 75 mole percent, having a trans-double bond in a proportion of 0 to 10 mole percent and a cis-double bond in a proportion of 25 to 75 mole percent, wherein the totality of the monomer units (A), (B) and (C) is supplemented to 100 mole percent, and which is characterized in that it has a number-average mole mass of 1,000 to 3,000 g/mole. The invention further relates to a method for producing polybutadienes, the use of the polybutadiene according to the invention and compositions containing polybutadiene according to the invention.

Claims

1. A polybutadiene comprising monomer units derived from 1,3-butadiene ##STR00002## wherein the proportion of monomer units of the formula (A) in the entirety of the monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, the proportion of units of the formula (B) in the entirety of the monomer units derived from 1,3-butadiene present in the polybutadiene is 0 to 10 mole percent and the proportion of monomer units of the formula (C) in the entirety of the monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, wherein the entirety of the monomer units (A), (B) and (C) add up to 100 mole percent, and the polybutadiene has a number-average molar mass of 1000 to 3000 g/mol.

2. The polybutadiene according to claim 1, wherein the polybutadiene has a viscosity of 2000 to 8000 mPa s.

3. The polybutadiene according to claim 1, wherein said polybutadiene has a dispersity of 2.1 to 3.0.

4. The polybutadiene according to claim 1.

5. The method for preparing polybutadienes by polymerizing 1,3-butadiene in the presence of a solvent and a catalyst system comprising a) a cobalt compound, b) an organoaluminium compound, c) an organophosphorus compound and d) water, wherein a mixture of catalyst system and solvent is initially charged and the 1,3-butadiene is metered into this mixture.

6. The method according to claim 5, wherein the polymerization is carried out at a pressure of from 2 to 7 bar.

7. The method according to claim 5, wherein the polymerization is carried out at a temperature of the reaction mixture of from 20 to 60 C.

8. The method according to claim 5, wherein the cobalt compound used is cobalt 2-ethylhexanoate.

9. The method according to claim 5, wherein the organophosphorus compound used is tris(2,4-di-tert-butylphenyl) phosphite or tris(ortho-phenylphenyl) phosphite.

10. The method according to claim 5, wherein the organoaluminium compound used is ethylaluminium sesquichloride or diethylaluminium chloride.

11. The method according to claim 5, wherein the molar ratio of cobalt compound to total amount of 1,3-butadiene used is from 1:2500 to 1:15 000.

12. The method according to claim 5, wherein the polybutadiene comprises monomer units derived from 1,3-butadiene ##STR00003## wherein the proportion of monomer units of the formula (A) in the entirety of the monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, the proportion of units of the formula (B) in the entirety of the monomer units derived from 1,3-butadiene present in the polybutadiene is 0 to 10 mole percent and the proportion of monomer units of the formula (C) in the entirety of the monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, wherein the entirety of the monomer units (A), (B) and (C) add up to 100 mole percent, and the polybutadiene has a number-average molar mass of 1000 to 3000 g/mol.

13. A product comprising the polybutadiene according to any of claim 1 wherein the product is selected from the group consisting of rubber, synthetic rubber, tyres, adhesive formulations, coating compositions, flexographic printing plates, coating agents, coating agent components, in the recycling of rubber and as plasticizers.

14. A composition comprising the polybutadiene according to claim 1 or conversion products of polybutadiene with other compounds.

15. The composition according to claim 14, wherein the proportion of the polybutadiene which are present in the composition or were used for preparing the conversion products, based on the composition, is from 0.1 to 90% by weight.

16. The polybutadiene according to claim 2, wherein said polybutadiene has a dispersity of 2.1 to 3.0.

17. The method according to claim 6, wherein the cobalt compound used is cobalt 2-ethylhexanoate.

18. The method according to claim 6, wherein the organophosphorus compound used is tris(2,4-di-tert-butylphenyl) phosphite or tris(ortho-phenylphenyl) phosphite.

19. The method according to claim 7, wherein the organoaluminium compound used is ethylaluminium sesquichloride or diethylaluminium chloride.

20. The method according to claim 7, wherein the molar ratio of cobalt compound to total amount of 1,3-butadiene used is from 1:2500 to 1:15 000.

Description

EXAMPLES

Example 1

[0053] In a 5 L metal reactor, 980 ml of benzene, 1.48 mmol of Co(2-ethylhexanoate), 3.03 mmol of triphenyl phosphite and 27.6 mmol of water were combined.

[0054] Using nitrogen, the pressure in the reaction vessel was increased to 3.5 bar and 11.85 mol of butadiene were rapidly metered in. After addition was complete, 29.51 mmol of diethylaluminium chloride were added and the reaction mixture was stirred for 4 h and the temperature kept constant at ca. 50 C. by means of a jacket cooler and thermostat. To terminate the polymerization, the reaction mixture was quenched with 600 ml of water and remaining butadiene purged by means of nitrogen.

[0055] The organic phase was separated from the aqueous phase, filtered and freed from solvent on the rotary evaporator or by means of a thin-film evaporator under reduced pressure (p<1 mbar, T=130 C.).

Example 2

[0056] In a 5 L metal reactor, 982 ml of benzene, 2.01 mmol of Co(2-ethylhexanoate), 6.03 mmol of tris(2,4-di-tert-butylphenyl) phosphite, 19.22 mmol of water and 16.28 mmol of ethylaluminium sesquichloride were combined and stirred at room temperature for 10 min.

[0057] Using nitrogen, the pressure in the reaction vessel was increased to 3.5 bar and 11.84 mol of butadiene was metered in continuously over a period of 2.4 h. The reaction mixture was kept at a constant temperature of ca. 30 C. during the course of the reaction via thermostat by means of a jacket cooler. After completion of the addition, the reaction mixture was stirred for a further 5 min. To terminate the polymerization, the reaction mixture was quenched with 1000 ml of water and remaining butadiene purged by means of nitrogen.

[0058] The organic phase was separated from the aqueous phase, filtered and freed from solvent on the rotary evaporator or by means of a thin-film evaporator under reduced pressure (p<1 mbar, T=130 C.).

Example 3

[0059] In a 5 L metal reactor, 1403 ml of benzene, 3.01 mmol of Co(2-ethylhexanoate), 10.22 mmol of tris(2,4-di-tert-butylphenyl) phosphite, 24.81 mmol of water and 27.15 mmol of ethylaluminium sesquichloride were combined and stirred at room temperature for 10 min.

[0060] Using nitrogen, the pressure in the reaction vessel was increased to 3.5 bar and 17.76 mol of butadiene was metered in continuously over a period of 3.5 h. The reaction mixture was kept at a constant temperature of ca. 28 C. during the course of the reaction via thermostat by means of a jacket cooler. After completion of the addition, the reaction mixture was stirred for a further 20 min. To terminate the polymerization, the reaction mixture was quenched with 1500 ml of water and remaining butadiene purged by means of nitrogen.

[0061] The organic phase was separated from the aqueous phase, filtered and freed from solvent on the rotary evaporator or by means of a thin-film evaporator under reduced pressure (p<1 mbar, T=130 C.).

Comparative Example I

[0062] In a 5 L metal reactor, 1.933 ml of benzene, 3.91 mmol of Co(2-ethylhexanoate), 9.04 mmol of tris(2,4-di-tert-butylphenyl) phosphite, 30.37 mmol of water and 30.34 mmol of ethylaluminium sesquichloride were combined and stirred at room temperature for 10 minutes.

[0063] The pressure in the reaction vessel was increased to 3.5 bar by means of nitrogen and 23.13 mol of butadiene were added continuously over a period of 2.5 h. The reaction mixture was maintained via thermostat at a constant temperature of ca. 20 C. during the course of the reaction by means of a jacketed cooler. After addition was complete, the reaction mixture was stirred for a further 20 minutes. To terminate the polymerisation, the reaction mixture was quenched with 1250 ml of water and remaining butadiene driven out by means of nitrogen.

[0064] The organic phase was separated from the aqueous phase, filtered and freed from solvent on a rotary evaporator or a thin-film evaporator in a vacuum (p<1 mbar, T=130 C.).

Comparative Example II

[0065] In a 5 L metal reactor, 1.942 ml of benzene, 3.91 mmol of Co(2-ethylhexanoate), 13.32 mmol of tris(2,4-di-tert-butylphenyl) phosphite, 29.86 mmol of water and 30.02 mmol of ethylaluminium sesquichloride were combined and stirred at room temperature for 10 minutes.

[0066] The pressure in the reaction vessel was increased to 3.5 bar by means of nitrogen and 23.12 mol of butadiene were added continuously over a period of 2.5 h. The reaction mixture was maintained via thermostat at a constant temperature of ca. 45 C. during the course of the reaction by means of a jacketed cooler. After addition was complete, the reaction mixture was stirred for a further 20 minutes. To terminate the polymerisation, the reaction mixture was quenched with 1250 ml of water and remaining butadiene driven out by means of nitrogen.

[0067] The organic phase was separated from the aqueous phase, filtered and freed from solvent on a rotary evaporator or a thin-film evaporator in a vacuum (p<1 mbar, T=130 C.).

[0068] Some properties of the polybutadienes produced were determined as described above. The results are shown in Table 1a.

TABLE-US-00001 TABLE 1a Properties of the polybutadienes produced 1,2- 1,4- 1,4- Vinyl cis trans Mn Mw Viscosity Conversion # [%] [%] [%] [g/mol] [g/mol] D [mPa*s] [%] Example 1 59 37 4 1748 3921 2.24 3578 51.6 Example 2 58 38 4 1526 4245 2.78 4432 81.7 Example 3 61 36 3 1264 3628 2.87 5228 83.8 Comparative 52 44 4 3214 11 438 3.56 31 740 87.1 example I Comparative 61 37 2 893 2713 3.04 1570 62.0 example II

[0069] As can be inferred from table 1a, the polybutadiene according to comparative examples has a viscosity which is considerably outside the region desirable for basic processing/application.

Example 4: Preparation of Adhesive Formulations

[0070] To investigate the properties in adhesive formulations, several reaction batches were conducted according to examples 1 and 2, combined and freed of residual solvent on the thin-film evaporator. Example 4 results from combining six individual experiments according to example 1 and example 5 from combining four individual experiments according to example 2. The product LITHERNE PH from Synthomer was also used. The properties investigated are shown in Table 1b.

TABLE-US-00002 TABLE 1b Properties of the polybutadienes investigated 1,2- 1,4- 1,4- Vinyl cis trans Mn Mw Viscosity # [%] [%] [%] [g/mol] [g/mol] D [mPa*s] Example 4 59 37 4 1571 3486 2.22 3531 Example 5 58 38 4 1480 4018 2.71 4940 LITHENE 45 34 21 2653 6600 2.49 11 240 PH = reference

[0071] As can be inferred from Tables 1a and 1b, the polybutadienes prepared in accordance with the invention are characterized by a high 1,4-cis and low 1,4-trans content and also a low viscosity based on the high 1,2-vinyl content.

[0072] Some of the polybutadienes specified in Tables 1a and 1b were used in adhesive formulations and tested in comparison to the reference LITHENE PH. For this purpose, the polybutadienes were mixed in a vacuum dissolver with the same amount of the raw materials customary for this application, such as ZnO, stearic acid, chalk, talc, sulfur, vulcanization accelerator, etc. The precise composition of the formulations tested are to be found in Table 2.

TABLE-US-00003 TABLE 2 Composition of the formulations (data in % by mass) Formulation 1 2 LITHENE PH (Synthomer) 19 Example 5 19 POLYVEST MA 75 (Evonik Industries AG) 4 4 Polyisoprene LIR 50 (Kuraray liquid rubber) 8 8 IONOL LC (Raschig GmbH) 1 1 IRGAFOS 168 (BASFSE) 0.2 0.2 IRGANOX 1520 L (BASFSE) 0.1 0.1 Furnace black 101 (Orion Engineered Carbons GmbH) 1 1 Sulfur 3.3 3.3 ZnO 3 3 Stearic acid 0.3 0.3 CaO 1 1 Alpha Talc CT P (Alpha Calcit Fllstoff GmbH & Co. KG) 6 6 OMYACARB 2 AL (Omya) 50 50 VULKACIT DM/C (Lanxess) 3 3 VULKACIT ZBEC (Lanxess) 0.1 0.1 100 100

Example 5: Testing the Adhesive Formulations

[0073] The Shore A hardness is determined according to DIN 53505-A using the instrument SHOREdigital Shore Durometer A from BAQ GmbH on test specimens with 50 mm diameter and 6 mm thickness, more than 16 hours after vulcanization at 23 C. On each test specimen, a measurement was carried out each time at 6 different points. The Shore A hardnesses specified are mean values of the individual measurements.

[0074] The tensile strength and elongation at break were determined as follows: Films with defined layer thickness of 3 mm were generated and crosslinked at 170 C. for 30 minutes. From said films, the actual test specimens of 15 mm width and ca. 100 mm length were cut. The tensile tests were carried out using the universal tester inspekt table 10kn-1EDC2/300W, TM Standard from Hegewald and Peschke. The testing was carried out according to DIN EN ISO 257 with a clamped length of 50 mm, at room temperature and a test speed of 5 mm/min. The results are shown in Table 3:

TABLE-US-00004 TABLE 3 Results of the tensile strength test and elongation at break test 1 2 Properties of the formulation Viscosity [Pa s] 1432 839 at 23 C. 1[1/s] Baking conditions 30 minutes at 170 C. Shore A hardness 74 72 Tensile strength [MPa] 2.4 2.87 Elongation at break [%] 91 98

[0075] As can be seen from Table 3, formulation 2 based on example 5 has a distinctly lower viscosity and improved strength to elasticity behavior.

[0076] The tensile shear strength was determined as follows:

[0077] To determine the tensile shear strength, a surface area of 2520 mm was bonded onto various substrates using the formulations 1 to 2 and crosslinked at 170 C. for 30 minutes.

[0078] The tensile shear tests were carried out using the universal tester inspekt table 10kn-1EDC2/300W, TM Standard from Hegewald and Peschke. The testing was carried out according to DIN EN 1465 at room temperature and a test speed of 5 mm/min. The results are shown in Table 4:

TABLE-US-00005 TABLE 4 Results of the tensile shear strength test 1 2 Properties of the formulation Baking conditions 30 min. 170 C. Tensile shear strength on steel [MPa] 2.63 3.0 Tensile shear strength on galvanized steel 2.58 2.9 [MPa] Tensile shear strength on aluminium [MPa] 2.44 2.7 Tensile shear strength on electrodeposition 2.02 2.4 paint [MPa]

[0079] The results of the test are shown in Table 4. It is significant to note that the use of polybutadienes according to the invention or prepared according to the invention leads to better tensile shear strengths on all substrates mentioned than the reference which was prepared using methods according to the prior art.