A catalyst and its application in the preparation of cycloolefin copolymer

Abstract

The present invention relates to the technical field of olefin polymerization (IPC classification number is C08F210 / 02), and particularly relates to a catalyst and its application in the preparation of cycloolefin copolymers. The structural formula of the catalyst is that R4 and R5 each independently selected from any one of hydrogen, alkyl, alkoxy, aryl, haloalkyl, and haloarene, and R6 is selected from any one of haloalkyl and haloarene. The catalyst provided by the present invention can well regulate the polymerization reaction process, especially control the reaction process of cycloolefin unit B, make the polymer more flexible, avoid the situation of product plasticity caused by the out-of-control reaction process, and the prepared cycloolefin copolymer has high safety and good flexibility, and is suitable for the medical device field.

Description

Technical Field

[0001] The present invention relates to the technical field of olefin polymerization (IPC classification number: C08F210 / 02), and particularly relates to a catalyst and its application in the preparation of cycloolefin copolymers. Background Art

[0002] Cycloolefin copolymers are widely used in the medical field due to their high barrier properties, transparency, stability, and purity. Medical products such as medical catheters and packaging bags often require more flexibility to meet the actual treatment needs. However, the commercially available cycloolefin copolymers have a relatively high glass transition temperature, that is, they show plasticity at room temperature, with a large tensile strength and a small elongation at break, which cannot meet the high requirements of the development of medical technology for mechanical materials. In the synthesis process of cycloolefin copolymers, the catalytic system is an important factor affecting the glass transition temperature. Conventional catalysts often can only act well in a reaction system with a low monomer content to achieve an ideal glass transition temperature. However, when the monomer content is low, the reaction process control is difficult, and the reaction cost increases. In addition, the conventional cycloolefin copolymerization catalytic system is sensitive to water and oxygen, and usually requires the use of alkyl aluminum compounds as scavengers to remove impurities in the polymerization system. The introduction of alkyl aluminum compounds is not favorable for the environment and cost.

[0003] The prior art CN97197192 discloses an elastic cycloolefin copolymer, and the prepared elastic copolymer has a glass transition temperature of -30 - 50 °C. However, the method disclosed in this patent involves the use of a metallocene main catalyst and a large amount of alkyl aluminum compound cocatalysts. Alkyl aluminum compounds are highly flammable, which on the one hand increases the potential safety hazards in production, and on the other hand, due to the need to remove metal aluminum in the polymer during production, it causes an increase in emissions, which is not favorable for environmental protection. And the cocatalyst itself is expensive, resulting in a high product cost. The prior art CN114395063A discloses a cycloolefin copolymer with polar groups and a preparation method. The prepared cycloolefin copolymer has a wide range of adjustable glass transition temperatures, but still cannot meet the requirements for the balance of flexibility and plasticity in the medical device field within its adjustable range.

[0004] Therefore, there is an urgent need in the prior art for a new catalyst that can catalyze efficiently and is pollution-free and safe to solve the problem of the difficulty in balancing flexibility and plasticity of cycloolefin copolymers in the medical device field. Summary of the Invention

[0005] The first aspect of the present invention provides a catalyst, and the catalyst has the structure of formula (1),

[0006]

[0007] wherein each of R4 and R5 is independently selected from any one of hydrogen, alkyl, alkoxy, aryl, haloalkyl, and haloarene;

[0008] R6 is selected from any one of haloalkyl and haloarene.

[0009] Each of R4 and R5 is independently selected from any one of hydrogen, methyl, ethyl, propyl, isopropyl, methoxy, ethoxy, propoxy, phenyl, trifluoromethyl, perfluoropropyl, and pentafluorophenyl.

[0010] Each of R4 and R5 is independently selected from any one of hydrogen, methyl, methoxy, phenyl, trifluoromethyl, and pentafluorophenyl.

[0011] R6 is selected from any one of trifluoromethyl and pentafluorophenyl.

[0012] The preparation method of the catalyst includes: adding toluene, pyridine, tetramethylethylenediamine dimethyl nickel (CAS: 110-18-9), and a ligand into a container, stirring at room temperature (25±1°C), gas release can be seen during the reaction process, and the solution gradually turns yellow. When there is no gas release, the reaction ends. Filter the system, and subject the filtrate to freeze-drying under vacuum to obtain a yellow catalyst.

[0013] In the case of conventional catalysts with different monomer ratios, the monomer content in the copolymer also varies greatly, which can be reflected in the fluctuation of the glass transition temperature of the product. At the same time, the catalytic activity of the system also varies greatly. Therefore, when preparing a cycloolefin copolymer with a lower content of cycloolefin monomers using a conventional catalytic system, generally, the ratio of raw material monomers (cycloolefin / open-chain olefin) needs to be controlled at a lower level. Otherwise, the glass transition temperature of the obtained cycloolefin copolymer will increase, resulting in the loss of elastic properties. However, in the case of a lower monomer ratio, as the cycloolefin monomer is consumed during the polymerization reaction, the monomer ratio changes greatly, and the polymer properties fluctuate greatly, increasing the difficulty of process control and raising the production cost.

[0014] The applicant has found that the catalyst containing the above substituents is more conducive to preparing the cycloolefin copolymer required by the present invention. The steric hindrance effect between the substituents and the polymerization monomers has less selectivity for the large-volume cycloolefin unit B. By increasing the ratio of raw material monomers (B / A), the content fluctuation of the cycloolefin unit B in the obtained cycloolefin copolymer is smaller, still less than 30 mol%, and the change in the catalytic activity of the polymerization system is also smaller. In addition, the electronic effect of the substituents on the metal center can better regulate the polymerization effect.

[0015] The second aspect of the present invention provides an application of a catalyst in the preparation of a cycloolefin copolymer. The preparation method of the cycloolefin copolymer includes: polymerizing a vinyl unit A and a cycloolefin unit B under the catalyst at 20-120°C and 0.01-10 MPa to obtain a cycloolefin copolymer.

[0016] The molar ratio of the vinyl unit A to the cycloolefin unit B is (70 - 99):(1 - 30).

[0017] The vinyl unit A is ethylene monomer.

[0018] The structural formula of the cycloolefin unit B is shown in Formula (2):

[0019]

[0020] m is 0 or 1, R2 is selected from hydrogen, C1 - C10 alkyl, C6 - C10 aryl, and R3 is selected from one or more of hydrogen, C1 - C10 alkyl, C6 - C10 aryl.

[0021] The applicant intends to provide a cycloolefin copolymer with better elastic flexibility at room temperature. Therefore, the content of the cycloolefin unit B is controlled to be relatively low. However, during the reaction process, the vinyl unit A is more likely to react, and the reaction activity of the cycloolefin unit B is relatively low, making the reaction process difficult to control, often resulting in a higher plasticity of the product. The catalyst prepared by the present invention can coordinate the reaction process, and the copolymer prepared has good elasticity at room temperature.

[0022] Preferably, the glass transition temperature of the prepared cycloolefin copolymer is -30 - 60 °C.

[0023] Preferably, the melting point of the prepared cycloolefin copolymer is 40 - 135 °C.

[0024] Preferably, the elongation at break of the prepared cycloolefin copolymer is greater than 100%.

[0025] By controlling the molar ratio of the vinyl unit A to the cycloolefin unit B and regulating the reaction process through the catalyst, the prepared cycloolefin copolymer has a lower glass transition temperature, and thus has higher flexibility, which can meet the flexibility requirements of medical devices.

[0026] Preferably, the prepared cycloolefin copolymer is a non-polar cycloolefin copolymer.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The catalyst provided by the present invention can well regulate the polymerization reaction process, especially control the reaction process of the cycloolefin unit B, make the polymer more flexible, and avoid the situation of product plasticity caused by out-of-control reaction process;

[0029] 2. During the preparation of the cycloolefin copolymer, no cocatalyst is required, avoiding the use of compounds such as alkylaluminum, simplifying the production process, reducing the production cost, and reducing the adverse impact on the environment;

[0030] 3. The catalytic system of the present invention has strong tolerance to water and oxygen, does not require deoxygenation and dehydration during the polymerization process, and does not require the use of alkyl aluminum compounds as scavengers;

[0031] 4. In the range of a relatively wide monomer ratio of (70 - 99):(1 - 30), a cycloolefin copolymer with a lower content of cycloolefin units can be prepared, which facilitates process control in production;

[0032] 5. The cycloolefin copolymer prepared by the present invention has high safety and good flexibility, and is suitable for the medical device field. Detailed implementation manners

[0033] Example 1

[0034] In the first aspect of this example, a catalyst is provided. The catalyst has the structure of formula (1),

[0035]

[0036] R4 is CF3, R5 is Ph, and R6 is C6F5.

[0037] The preparation method of the catalyst includes: adding 200 mL of toluene, 8.0 g of pyridine, 0.9 g of nickel dimethyl tetramethylethylenediamine (CAS: 110 - 18 - 9), and 2.9 g of ligand LC - 1 into a container, stirring at room temperature (25 ± 1 °C). Gas release can be seen during the reaction process, and the solution gradually turns yellow. When there is no gas release, the reaction ends. Filter the system, and subject the filtrate to freeze - vacuum drying to obtain 3.3 g of yellow catalyst C - 1, with a yield of 94%.

[0038] The structural formula of the ligand LC - 1 is Purchased from Energy Chemical Co., Ltd.

[0039] In the second aspect of this example, an application of a catalyst in the preparation of a cycloolefin copolymer is provided. The cycloolefin unit B is a norbornene monomer. The preparation method of the cycloolefin copolymer includes:

[0040] Add 200 mL of a toluene solution of 2.0 mol / L norbornene monomer (B) into a reaction kettle under a nitrogen atmosphere, stir at 500 r / min, introduce 17 g of ethylene monomer (A), increase the pressure to 4.0 MPa, and equilibrate at 70 °C for 30 minutes. Add 2 mL of a toluene solution containing 2 μmol of catalyst C - 1 to start the polymerization reaction. Keep the temperature and pressure of the system unchanged and react for 30 min. Stop stirring, let the reaction system cool to room temperature (25 ± 1 °C), release the pressure, add the reaction solution to anhydrous ethanol and stir to precipitate the polymer. Filter the polymer and dry it in a vacuum oven at 80 °C to constant weight to obtain the cycloolefin copolymer.

[0041] Example 2

[0042] In the first aspect of this example, a catalyst is provided. The catalyst has the structure of formula (1).

[0043]

[0044] R4 is OCH3, R5 is Ph, and R6 is C6F5.

[0045] The preparation method of the catalyst is the same as that of Example 1, except that 2.6 g of ligand LC-2 is added to obtain 3.1 g of yellow catalyst C-2 with a yield of 96%.

[0046] The structural formula of the ligand LC-2 is Purchased from Aladdin Chemistry Co., Ltd.

[0047] In the second aspect of this example, an application of a catalyst in the preparation of a cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Example 1, except that the added catalyst is catalyst C-2.

[0048] Example 3

[0049] In the first aspect of this example, a catalyst is provided. The catalyst has the structure of formula (1).

[0050]

[0051] R4 is Ph, R5 is Ph, and R6 is C6F5.

[0052] The preparation method of the catalyst is the same as that of Example 1, except that 3.0 g of ligand LC-3 is added to obtain 3.3 g of yellow catalyst C-3 with a yield of 92%.

[0053] The structural formula of the ligand LC-3 is Purchased from Aladdin Chemistry Co., Ltd.

[0054] In the second aspect of this example, an application of a catalyst in the preparation of a cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Example 1, except that the added catalyst is catalyst C-3.

[0055] Example 4

[0056] In the first aspect of this example, a catalyst is provided. The catalyst has the structure of formula (1).

[0057]

[0058] R4 is Ph, R5 is Ph, and R6 is CF3.

[0059] The preparation method of the catalyst is the same as that in Example 1, except that 2.6 g of ligand LC-4 is added to obtain 2.9 g of yellow catalyst C-4 with a yield of 91%.

[0060] The second aspect of this example provides an application of a catalyst in the preparation of cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that in Example 1, except that the catalyst added is catalyst C-4.

[0061] The structural formula of the ligand LC-4 is Purchased from Energy Chemical Co., Ltd.

[0062] The product weight, glass transition temperature (Tg), melting point (Tm), B monomer content, and elongation at break of the cycloolefin copolymers prepared in Test Examples 1-4 were tested, and the results are shown in Table 1.

[0063] Test methods for Tg and Tm: Measured by differential scanning calorimeter (DSC) with a heating and cooling rate of 20 °C / min, and Tg and Tm are taken from the signal data in the second heating curve.

[0064] Test method reference for B monomer content: Calculated from the integral intensity ratio of the corresponding signal peaks in nuclear magnetic resonance hydrogen spectrum (1H NMR).

[0065] Test method reference for elongation at break: Measured by a universal tensile testing machine. The test method refers to the national standard GB / T 1040.3 for tensile permanent deformation: After the specimen is broken, the actual length is the change rate relative to the original length.

[0066] Table 1

[0067]

[0068] Referring to the test results in Table 1, the cycloolefin copolymers prepared using the catalysts of Examples 1-4 have a lower glass transition temperature, B monomer content, and good elongation at break, indicating that the catalyst has excellent regulation effect and good catalytic effect in this system.

[0069] Example 5

[0070] The first aspect of this example provides a catalyst, and the specific implementation method is the same as that in Example 1.

[0071] The second aspect of this example provides an application of a catalyst in the preparation of cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that in Example 1, except that 12.5 g of ethylene is added and the pressure is increased to 3.0 MPa.

[0072] Example 6

[0073] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0074] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that 8 g of ethylene is added and the pressure is raised to 2.0 MPa.

[0075] Example 7

[0076] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0077] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that 4.5 g of ethylene is added and the pressure is raised to 1.0 MPa.

[0078] Example 8

[0079] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0080] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that a toluene solution of 200 mL of 4.0 mol / L norbornene monomer (B) is added.

[0081] Example 9

[0082] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0083] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that while adding a toluene solution of 200 mL of 2.0 mol / L norbornene monomer (B), 10 mL of water is added.

[0084] Example 10

[0085] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0086] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that while adding a toluene solution of 200 mL of 2.0 mol / L norbornene monomer (B), 10 mL of ethanol is added.

[0087] Example 11

[0088] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0089] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that while adding 200 mL of toluene solution of 2.0 mol / L norbornene monomer (B), 10 mL of diethyl ether is added.

[0090] The product weight, glass transition temperature (Tg), melting point (Tm), and B monomer content of the cycloolefin copolymers prepared in Test Examples 5 - 11 were tested, and the results are shown in Table 2.

[0091] Table 2

[0092]

[0093]

[0094] Example 12

[0095] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0096] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 1, except that the structural formula of the cycloolefin unit B is shown in Formula (2),

[0097]

[0098] where m = 0, R2 = H, and R3 = Me.

[0099] Example 13

[0100] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0101] In the second aspect of this embodiment, an application of the catalyst in the preparation of cycloolefin copolymer is provided. The preparation method of the cycloolefin copolymer is the same as that of Embodiment 10, except that m = 0, R2 = H, and R3 = Et.

[0102] Example 14

[0103] In the first aspect of this embodiment, a catalyst is provided, and the specific implementation manner is the same as that of Embodiment 1.

[0104] The second aspect of this embodiment provides an application of a catalyst in the preparation of cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that in Example 10, except that m = 1, R2 = H, and R3 = Me.

[0105] The product weight, glass transition temperature (Tg), melting point (Tm), B monomer content, and elongation at break of the cycloolefin copolymers prepared in Test Examples 10 - 14 were measured, and the results are shown in Table 3.

[0106] Table 3

[0107]

[0108]

[0109] Comparative Example 1

[0110] This comparative example provides an application of a catalyst in the preparation of cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that in Example 1, except that the catalyst is rac-ethylenebis(1-indenyl)zirconium dichloride (CAS: 100080-82-8).

[0111] Comparative Example 2

[0112] This comparative example provides an application of a catalyst in the preparation of cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that in Example 1, except that the catalyst is rac-ethylenebis(1-indenyl)zirconium dichloride, and while adding 200 mL of a toluene solution of 2.0 mol / L norbornene monomer (B), 2 mL of a toluene solution of 10 mol / L methylaluminoxane is added.

[0113] Comparative Example 3

[0114] This comparative example provides an application of a catalyst in the preparation of cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that in Example 1, except that the catalyst is rac-ethylenebis(1-indenyl)zirconium dichloride, and while adding 200 mL of a toluene solution of 2.0 mol / L norbornene monomer (B), 2 mL of a toluene solution of 10 mol / L methylaluminoxane is added, and 4.5 g of ethylene is added, and the polymerization pressure is 1 MPa.

[0115] Comparative Example 4

[0116] This comparative example provides an application of a catalyst in the preparation of a cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that of Example 1, except that the catalyst is rac-ethylenebis(1-indenyl)zirconium dichloride. While adding 200 mL of a toluene solution of 2.0 mol / L norbornene monomer (B), 2 mL of a toluene solution of 10 mol / L methylaluminoxane and 10 mL of water are added.

[0117] Comparative Example 5

[0118] The first aspect of this comparative example provides a catalyst having the structure of formula (1).

[0119]

[0120] R4 is CF3, R5 is Ph, and R6 is H.

[0121] The second aspect of this comparative example provides an application of a catalyst in the preparation of a cycloolefin copolymer. The preparation method of the cycloolefin copolymer is the same as that of Example 1.

[0122] Test the product weight, glass transition temperature (Tg), melting point (Tm), B monomer content, and elongation at break of the cycloolefin copolymers prepared in Comparative Examples 1-5. The results are shown in Table 4.

[0123] Table 4

[0124]

[0125] It can be seen from Comparative Examples 1-2 that in this system, the use of a conventional catalyst cannot complete the polymerization reaction. It is necessary to add a cocatalyst alkylaluminum, but this will cause a series of environmental pollution and safety problems. In Comparative Example 3, the pressure was reduced, and the decrease in the ethylene feed rate led to a significant decrease in the elongation at break, and the polymer showed plasticity. Comparative Example 4 shows the intolerance of the conventional catalyst to the water-oxygen system. In summary, it can prove the beneficial effects of the catalyst of the present invention in terms of polymer flexibility and water-oxygen tolerance.

Claims

1. A catalyst, characterized in that, The catalyst has the structure of formula (1), wherein each of R4 and R5 is independently selected from any one of alkyl, alkoxy, aryl, haloalkyl, and haloarene; R6 is selected from any one of trifluoromethyl and perfluoropropyl.

2. Use of the catalyst according to claim 1 in the preparation of cycloolefin copolymers, characterized in that, The method for preparing the cycloolefin copolymer comprises: polymerizing a vinyl unit A and a cycloolefin unit B under the catalyst at 20 - 120 °C and 0.01 - 10 MPa to obtain a cycloolefin copolymer; The elongation at break of the prepared cycloolefin copolymer is greater than 100%.

3. Use of a catalyst according to claim 2 in the preparation of a cycloolefin copolymer, characterized in that, The molar ratio of the vinyl unit A to the cycloolefin unit B is (70 - 99):(1 - 30).

4. Use of a catalyst according to claim 3 in the preparation of a cycloolefin copolymer, characterized in that, The glass transition temperature of the prepared cycloolefin copolymer is -30 - 60 °C.

5. Use of a catalyst according to claim 4 in the preparation of a cycloolefin copolymer, characterized in that, The melting point of the prepared cycloolefin copolymer is 40 - 135 °C.

6. Use of a catalyst according to claim 5 in the preparation of a cycloolefin copolymer, characterized in that, The prepared cycloolefin copolymer is a non-polar cycloolefin copolymer.

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