A vinyl elastomeric material and a method for its preparation

Abstract

The application discloses a kind of vinyl elastomer material and preparation method thereof.The vinyl elastomer is copolymerized by ethylene monomer, alpha-olefin and siloxane bond-containing polyvinyl compound under the action of metallocene catalyst system, Si-O bond structural unit is introduced into polymer molecular chain and constructs the molecular structure with long chain branch characteristics, and the molar ratio of Si-O bond and C-C bond is 0.0001%-1%.The structural general formula of siloxane bond-containing polyvinyl compound is X 1 -Si (R 1 ) 2-O-Si (R 2 ) 2-X 2 Or [Si (R 3 ) (X 3 ) -O] m (m≥3), in general formula, X 1 , X 2 , X 3 It is the alpha-olefin group of C2-C 20 , R 1 , R 2 , R 3 It is linear, branched or isomerized alkyl group or aryl group of C1-C 20 . The vinyl elastomer preparation can use solution method or gas phase polymerization process, and the vinyl elastomer has the characteristics of high melt strength, easy processing, excellent mechanical properties, optical properties and electrical properties.

Description

Technical Field

[0001] This invention belongs to the field of polyolefin elastomer material technology, and relates to a vinyl elastomer material and its preparation method. Specifically, it relates to a vinyl elastomer with a silicon-oxygen bond structure introduced into the molecular chain and its preparation method, and particularly to a vinyl elastomer material prepared by copolymerization of ethylene, α-olefin and polyvinyl compounds containing silicon-oxygen bonds. Background Technology

[0002] Vinyl elastomers are a class of polyolefin materials formed by copolymerization of ethylene and α-olefins. They possess excellent flexibility, processability, and chemical stability, and are widely used in films, foam materials, wire and cable sheathing, and engineering plastic modification. Existing vinyl elastomers typically improve their flexibility and transparency by controlling the type and content of α-olefins; however, their molecular chain structure is still predominantly linear with short branches, which limits their melt strength, processing stability, and processing efficiency.

[0003] To improve the melt strength and processability of polyolefin elastomers, existing technologies have proposed introducing long-branched structures into the molecular chain through cascade polymerization, high-energy radiation, or melt branching. However, these methods generally suffer from problems such as complex processes, high energy consumption, difficulty in precisely controlling the structure, or poor material recyclability, which limit their industrial application.

[0004] On the other hand, existing vinyl elastomer molecular chains are mainly composed of C-C bonds, and the methods for structural regulation are relatively limited. How to introduce new molecular structure regulation units while maintaining the advantages of traditional polyolefin polymerization processes, so as to achieve synergistic regulation of material rheological behavior, crystallization behavior and overall properties, remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a vinyl elastomer and its preparation method. By introducing silicon-oxygen bond-containing structural units into the vinyl elastomer molecular chain, the branching structure of the molecular chain can be effectively controlled at a low introduction ratio, thereby significantly improving the melt strength, processing performance, and service performance of the material.

[0006] To achieve the above objectives, this invention provides a method for preparing a vinyl elastomer, wherein an ethylene monomer, an α-olefin, and a polyvinyl compound containing silicon-oxygen bonds are copolymerized under the action of a catalyst to obtain the vinyl elastomer. The general structural formula of the polyvinyl compound containing silicon-oxygen bonds is X. 1 -Si(R 1 )2-O-Si(R 2 )2-X 2 or [Si(R)] 3 (X) 3 )-O]m (m≥3) In the general formula, X 1 X 2 X 3 For C2-C 20 α-olefin group, R 1 R 2 R 3 For C1-C 20 Straight-chain, branched, or isomerized alkyl or aryl groups.

[0007] Preferably, X 1 X 2 X 3 R is an α-olefin group of C2-C6. 1 R 2 R 3 It is a straight-chain, branched, or isomerized alkyl or aryl group of C1-C3, with 3≤m≤5.

[0008] Preferably, the polyvinyl compound containing silicon-oxygen bonds is selected from one or more of the following compounds: 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetraethyldisiloxane, 1,3-divinyl-1,1,3,3-tetra-n-propyldisiloxane, 1,3-divinyl-1,1,3,3-tetraisopropyldisiloxane, 1,3-diallyl-1,1,3,3-tetramethyldisiloxane, 1,3-diallyl-1,1,3,3-tetraethyldisiloxane, 1,3-diallyl-1,1,3,3-tetra-n-propyldisiloxane, 1,3-diallyl-1,1,3,3-tetraisopropyldisiloxane, 1,3-di(3-butenyl)- 1,1,3,3-Tetramethyldisiloxane, 1,3-Di(3-butenyl)-1,1,3,3-tetraethyldisiloxane, 1,3-Di(3-butenyl)-1,1,3,3-tetra-n-propyldisiloxane, 1,3-Di(3-butenyl)-1,1,3,3-tetraisopropyldisiloxane, 1,3-Di(4-pentenyl)-1,1,3,3-tetramethyldisiloxane, 1,3-Di(4-pentenyl)-1,1,3,3-tetraethyldisiloxane, 1,3-Di(4-pentenyl)-1,1,3,3-tetra-n-propyldisiloxane, 1,3-Di(4-pentenyl)-1,1,3,3-tetraisopropyldisiloxane, 1,3-Di(5-hexenyl)-1,1,3,3-tetramethyldisiloxane Alkane, 1,3-di(5-hexenyl)-1,1,3,3-tetraethyldisiloxane, 1,3-di(5-hexenyl)-1,1,3,3-tetra-n-propyldisiloxane, 1,3-di(5-hexenyl)-1,1,3,3-tetraisopropyldisiloxane, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-triethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-triallylcyclotrisiloxane, 1,3,5-triethyl-1,3,5-triallylcyclotrisiloxane, 1 3,5-tri-n-propyl-1,3,5-triallylcyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-triallylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tris(3-butenyl)cyclotrisiloxane, 1,3,5-triethyl-1,3,5-tris(3-butenyl)cyclotrisiloxane, 1,3,5-tri-n-propyl-1 3,5-Tris(3-butenyl)cyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-tris(3-butenyl)cyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tris(4-pentenyl)cyclotrisiloxane, 1,3,5-triethyl-1,3,5-tris(4-pentenyl)cyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-Tris(4-pentenyl)cyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-tris(4-pentenyl)cyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tris(5-hexenyl)cyclotrisiloxane, 1,3,5-triethyl-1,3,5-tris(5-hexenyl)cyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-tris(5-hexenyl)cyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-tris(5-hexenyl)cyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetraethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetrapropyl-1,3,5,7- Tetravinylcyclotetrasiloxane, 1,3,5,7-tetraisopropyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetraethyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetran-n-propyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetraisopropyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra(3-butenyl)cyclotetrasiloxane, 1,3,5,7-tetraethyl-1,3,5,7-tetra(3-butenyl)cyclotetrasiloxane, 1,3,5,7-tetran-n-propyl-1,3,5,7-tetravinylcyclotetrasiloxane, 7-Tetra(3-butenyl)cyclotetrasiloxane, 1,3,5,7-tetraisopropyl-1,3,5,7-tetra(3-butenyl)cyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5,7-tetraethyl-1,3,5,7-tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5, 7-Tetrapropyl-1,3,5,7-Tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5,7-Tetraisopropyl-1,3,5,7-Tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5,7-Tetramethyl-1,3,5,7-Tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7-Tetraethyl-1,3,5,7-Tetra(5-hexenyl)cyclotetrasiloxane Cyclotetrasiloxane, 1,3,5,7-tetra-n-propyl-1,3,5,7-tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7-tetraisopropyl-1,3,5,7-tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentavinylcyclopentasiloxane, 1,3,5,7,9-pentaethyl-1,3,5,7,9-pentavinylcyclopentasiloxane, 1,3,5,7,9-pentapropyl-1,3,5,7,9-pentavinylcyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-pentavinylcyclopentasiloxane, 1,3,5,7,9-Pentaethyl-1,3,5,7,9-pentaallylcyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-pentaallylcyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-pentaallylcyclopentasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1 3,5,7,9-Pentaethyl-1,3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-penta( 4-Pentenyl)cyclopentasiloxane, 1,3,5,7,9-pentaethyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-pentamethyl -1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane, 1,3,5,7,9-pentaethyl-1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane.

[0009] Preferably, the amount of α-olefin used is 5-40 mol, based on the total molar number of ethylene monomer and α-olefin; more preferably, the amount of α-olefin used is 10-30 mol.

[0010] Preferably, the amount of the polyvinyl compound containing silicon-oxygen bonds is 0.001-2.0 wt% based on the total weight of ethylene monomer and α-olefin; more preferably, the amount of the polyvinyl compound containing silicon-oxygen bonds is 0.01-1.0 wt%.

[0011] Preferably, the α-olefin monomer is at least one selected from 1-butene, 1-hexene, and 1-octene.

[0012] Preferably, the catalyst is a metallocene catalyst.

[0013] Preferably, the copolymerization reaction can be carried out under solution polymerization or gas-phase fluidized bed polymerization conditions. When using solution polymerization, the catalyst is a soluble metallocene catalyst, and the reaction system may further include a co-catalyst component; when using gas-phase fluidized bed polymerization, the catalyst is a supported metallocene catalyst, and the reaction system may further include a co-catalyst component, or no additional co-catalyst component may be added. The co-catalyst component is selected from organoaluminum compounds and / or organoboron compounds, preferably selected from one or more of methylaluminoxane, modified methylaluminoxane, tris(pentafluorophenyl)borane, borate, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum.

[0014] Preferably, the aluminum / metal ratio is 10:1-1000:1, based on the molar ratio of metallic aluminum in the co-catalyst to the central metal M in the metallocene catalyst; more preferably, the aluminum / metal ratio is 50:1-500:1.

[0015] Preferably, the boron / metal ratio is 0.1:1-100:1, based on the molar ratio of nonmetallic boron in the co-catalyst to the central metal M in the metallocene catalyst; more preferably, the boron / metal ratio is 0.5:1-50:1.

[0016] Preferably, the copolymerization reaction conditions include: polymerization pressure of 0.1-5.0 MPa, polymerization temperature of 20-200℃, and polymerization reaction time of 0.05-24 h.

[0017] Preferably, during the copolymerization process, hydrogen and antistatic agent components may be selectively added or not added, wherein the amount of hydrogen is 0-5.0 wt% and the amount of antistatic agent is 0-0.05 wt%.

[0018] According to a second aspect of the present invention, a vinyl elastomer prepared by the method described in the first aspect of the present invention is provided.

[0019] Preferably, the vinyl elastomer has a density of 0.858-0.900 g / cm³. 3 .

[0020] Preferably, the melt index of the vinyl elastomer measured at 190 °C and 2.16 kg load is 0.1-50 g / 10 min.

[0021] Preferably, the vinyl elastomer has a melting point of 40-100 °C.

[0022] Preferably, the vinyl elastomer has a light transmittance of 88-95%.

[0023] Preferably, the volume resistivity of the vinyl elastomer is 1.0 × 10⁻⁶. 15-1.0×10 19 Ω·cm.

[0024] Preferably, based on the total molar number of ethylene monomers and α-olefins, the actual insertion rate of α-olefins in the vinyl elastomer is 5-35 mol.

[0025] Preferably, the tensile strength of the vinyl elastomer is 5-30 MPa.

[0026] Preferably, the weight-average molecular weight of the vinyl elastomer is 5.0 × 10⁻⁶. 4 -6.0×10 5 g / mol.

[0027] Preferably, the vinyl elastomer has a molecular weight distribution of 2.0-8.0.

[0028] Through the above technical solution, this invention introduces silicon-oxygen bond-containing structural units into the vinyl elastomer molecular chain, achieving effective control over the branching structure of the molecular chain at a low introduction ratio. The resulting vinyl elastomer maintains good flexibility and high elongation at break while significantly improving melt strength and processing stability. It is suitable for various industrial polymerization processes such as solution polymerization and gas-phase polymerization, exhibiting strong process adaptability. The resulting material demonstrates good synergy in transparency, electrical properties, and mechanical properties, making it suitable for various application scenarios.

[0029] Compared with the prior art, the beneficial effects of this application are as follows: (1) This application introduces Si-O bond-containing structural units into the molecular chain of polyolefin elastomers, allowing some copolymer segments formed by ethylene and comonomers to be grafted onto the polymer backbone in the form of long-branched structures, thereby constructing a structure with controllable branching characteristics at the molecular chain level. Compared with conventional polyolefin elastomers containing only short-branched structures, this long-branched structure can significantly improve the melt strength of the material, make the shear thinning characteristics more obvious, which is beneficial to improving melt flowability and processing stability, while improving the tensile strength, tensile modulus and overall performance of the elastomer.

[0030] (2) The silicon-oxygen bond structural unit used in this application can generate a significant long-chain-like effect at the molecular chain level with a relatively low introduction amount in the polyolefin elastomer, thereby achieving effective control over the material properties. This method does not require significant modification to existing polyolefin polymerization equipment and can be directly prepared under existing solution or gas-phase polymerization process conditions. It has the advantages of low raw material consumption, low overall cost, and strong process adaptability, and is suitable for industrial scale-up and continuous production.

[0031] (3) Since the present application introduces Si-O bond structure into the polyolefin elastomer molecular chain, under specific conditions (such as acidic or alkaline media, hydrolysis or alcoholysis environment), the Si-O bond can be broken in a controlled manner, so that the original long-branched structure is transformed into a polyolefin elastomer structure dominated by short branches, thereby realizing the molecular chain degradation and efficient recycling of the material.

[0032] (4) By introducing a Si-O bond structure into the polyolefin elastomer molecular chain, this application enhances the interaction between the material and the surface of inorganic materials, making it particularly suitable for silicon- or oxygen-containing surface materials such as glass backsheets. This structure is beneficial for improving the bonding strength between the material and the inorganic substrate, and can reduce the amount of coupling agent added in some application scenarios. At the same time, the introduction of the Si-O bond structural unit helps to improve the volume resistivity of the polyolefin elastomer material, further broadening its application scope in photovoltaic packaging, electrical insulation, and composite materials. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane.

[0034] Figure 2 This is a schematic diagram of the structure of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane.

[0035] Figure 3 The rheological curves of vinyl elastomers S1 and D1 are shown.

[0036] Figure 4 This is the carbon NMR spectrum of vinyl elastomer S1. Detailed Implementation

[0037] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0038] The following methods are used to test the structure or properties of the vinyl elastomers produced in the embodiments described above: Rheological sweep frequency testing is used to analyze the relationship between the complex viscosity and shear frequency of vinyl elastomers.

[0039] Differential scanning calorimetry (DSC) is used to test the thermal properties of vinyl elastomers.

[0040] High-temperature gel permeation chromatography (GPC) is used to test the weight-average molecular weight and molecular weight distribution of vinyl elastomers.

[0041] Carbon nuclear magnetic resonance spectroscopy is used to test the insertion rate of copolymer monomers in vinyl elastomers.

[0042] Gradient density meters are used to test the density of vinyl elastomers.

[0043] A melt indexer is used to test the melt index of vinyl elastomers.

[0044] A haze meter is used to test the light transmittance of vinyl elastomers.

[0045] A volume resistivity tester is used to test the volume resistivity of vinyl elastomers.

[0046] A universal testing machine is used to test the tensile strength of vinyl elastomers.

[0047] Example 1 Hexane was added to an anhydrous and oxygen-free high-pressure reactor and pre-equilibrated under an inert atmosphere. Then, the α-olefin comonomer 1-hexene was added, with the amount being 10 mol% based on the total molar amount of ethylene and α-olefin. Next, the polyvinyl compound 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (with the structural formula shown below) containing silicon-oxygen bonds was added. Figure 1 As shown in the figure, the amount of ethylene and α-olefin used was 0.01 wt% based on the total weight of ethylene and α-olefin. Subsequently, the co-catalyst and main catalyst were added sequentially: based on the metallocene catalyst center metal M, [Al] / [M] = 200 and [B] / [M] = 2. The reaction system was raised to the polymerization temperature of 80 °C, and ethylene was introduced to a polymerization pressure of 1.5 MPa to initiate the polymerization reaction. The polymerization residence time was 0.5 h. After the reaction was completed, the pressure was reduced and the system was vented. A terminator was added to terminate the reaction. The resulting polymer solution was devolatilized, extruded, and granulated to obtain vinyl elastomer sample S1. Its analytical characterization results are shown in Table 1.

[0048] Example 2 Hexane was added to an anhydrous and oxygen-free high-pressure reactor. Displacement and pre-equilibration were performed under an inert atmosphere. Then, 1-octene, an α-olefin comonomer, was added at a rate of 30 mol% based on the total molar weight of ethylene monomer and α-olefin. Next, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, a polyvinyl compound containing silicon-oxygen bonds, was added at a rate of 0.10 wt% based on the total weight of ethylene monomer and α-olefin. Subsequently, the cocatalyst and main catalyst were added sequentially, with [Al] / [M] = 500 and [B] / [M] = 5, based on the central metal M of the metallocene catalyst. After heating to the polymerization temperature of 120°C, ethylene gas was introduced to bring the reactor pressure to 2.5 MPa, initiating the copolymerization reaction. The polymerization residence time was 1.0 h. Hydrogen was introduced into the reaction system during polymerization as a molecular weight regulator, at a rate of 0.01 wt% based on the total weight of ethylene monomer and α-olefin. After the reaction was completed, the pressure was reduced and the atmosphere was vented. A terminator was added to terminate the reaction. The resulting polymer solution was devolatilized, extruded, and granulated to obtain particulate vinyl elastomer sample S2. The analytical and characterization results are shown in Table 1.

[0049] Example 3 Isoalkanes were added to an anhydrous and oxygen-free high-pressure reactor. Displacement was performed under an inert atmosphere, followed by pre-equilibration at elevated temperature. Then, the α-olefin comonomer 1-butene was added, with the amount based on the total molar percentage of ethylene monomer and α-olefin, at 15 mol%. Next, a polyvinyl compound containing silicon-oxygen bonds, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane (its structural formula is shown below), was added. Figure 2 As shown in the figure, the amount of the catalyst used was 0.05 wt% based on the total weight of ethylene monomer and α-olefin. Subsequently, the co-catalyst and main catalyst were added sequentially, with [Al] / [M] = 200 and [B] / [M] = 2, based on the central metal M of the metallocene catalyst. The reaction system was heated to the polymerization temperature of 100 °C, and ethylene gas was introduced to bring the reactor pressure to 2.0 MPa and initiate the copolymerization reaction. The polymerization residence time was 0.8 h. No hydrogen or antistatic agent was added in this embodiment. After the reaction was completed, the pressure was reduced and vented, and a terminator was added to terminate the reaction. The resulting polymer solution was devolatilized, extruded, and granulated to obtain granular vinyl elastomer sample S3. Its analytical characterization results are shown in Table 1.

[0050] Example 4 Hexane was added to an anhydrous and oxygen-free high-pressure reactor. Displacement and pre-equilibration were performed under an inert atmosphere. Then, 1-hexene, an α-olefin comonomer, was added at a rate of 25 mol% based on the total molar weight of the ethylene monomer and α-olefin. Next, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, a polyvinyl compound containing silicon-oxygen bonds, was added at a rate of 0.20 wt% based on the total weight of the ethylene monomer and α-olefin. Subsequently, the cocatalyst and main catalyst were added sequentially, with [Al] / [M] = 500 and [B] / [M] = 5, based on the central metal M of the metallocene catalyst. Simultaneously, an antistatic agent was added at a rate of 0.02 wt% based on the total weight of the ethylene monomer and α-olefin. The reaction system was heated to the polymerization temperature of 150 °C, and ethylene gas was introduced to bring the reactor pressure to 3.0 MPa, initiating the copolymerization reaction. The polymerization residence time was 2.0 h. After the reaction was completed, the pressure was reduced and the atmosphere was vented. A terminator was added to terminate the reaction. The resulting polymer solution was devolatilized, extruded, and granulated to obtain particulate vinyl elastomer sample S4. The analytical and characterization results are shown in Table 1.

[0051] Example 5 A 20 L gas-phase fluidized bed reactor was purged with nitrogen for 30 min and then heated to 80 °C, with the total pressure adjusted to 2.0 MPa. 3.0 kg of dry polyethylene powder was added to the reactor as bed material to stabilize it in a fluidized state. Ethylene and 1-butene were introduced to stabilize the gas phase composition at: ethylene partial pressure 1.60 MPa, 1-butene partial pressure 0.40 MPa (total pressure 2.0 MPa). After polymerization began, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (0.05 wt% based on the total weight of ethylene and 1-butene), 20 μmol of supported metallocene catalyst (based on the central metal M), and co-catalyst components were added: 10.0 mmol of organoaluminum compound (based on Al), corresponding to [Al] / [M] = 500; and 60 μmol of organoboron compound (based on B), corresponding to [B] / [M] = 3. The reaction temperature was maintained at 80 °C, the total pressure at 2.0 MPa, and the gas phase composition remained constant for 1.5 h. After polymerization, the feeding of monomers and comonomers was stopped, the pressure was reduced, and nitrogen was used to purge and devolatilize for 20 min. The bed material was then discharged to obtain vinyl elastomer powder. The powder was then devolatilized and granulated using a twin-screw extruder at 190 °C to obtain granular vinyl elastomer sample G1. The analytical and characterization results are shown in Table 1.

[0052] Comparative Example 1 200 mL of hexane was added to a 1.2 L reactor in an anhydrous and oxygen-free environment. Under an inert atmosphere, 5 μmol of catalyst, borane co-catalyst, and methylaluminoxane were added sequentially. The molar ratio of borane to the catalyst central metal was [B] / [Ti] = 5, and the molar ratio of methylaluminoxane to the catalyst central metal was [Al] / [Ti] = 1000. Then, 1-butene was added to the reaction system to a concentration of 5 mol / L. The reaction system was heated to 120 °C, and ethylene gas was introduced to bring the pressure inside the reactor to 30 bar, initiating the polymerization reaction for 1 h. After the reaction was complete, a terminator was added to terminate the polymerization. The resulting product underwent post-treatment steps such as devolatilization and drying to obtain the vinyl elastomer comparative sample D1. Its analytical characterization results are shown in Table 1.

[0053] Comparative Example 2 A 20 L gas-phase fluidized bed reactor was dried and then purged with nitrogen for 30 min to obtain an anhydrous and oxygen-free environment. The temperature was then raised to 80 °C, and the total pressure of the reactor was adjusted to 2.0 MPa. 3.0 kg of dry polyethylene powder was added to the reactor as bed material to form a stable fluidized bed under gas circulation conditions. Ethylene and 1-butene were introduced to stabilize the gas phase composition at: ethylene partial pressure 1.60 MPa, 1-butene partial pressure 0.40 MPa (total pressure 2.0 MPa). A supported metallocene catalyst was added to the reactor at a rate of 20 μmol (based on the central metal M). The co-catalyst component in the supported metallocene catalyst was pre-loaded into the catalyst particles to satisfy [Al] / [M] = 500 and [B] / [M] = 3 (based on the central metal M). No additional co-catalyst components were added to the reactor during the polymerization process. The reaction temperature was maintained at 80 °C, the total pressure at 2.0 MPa, and the gas phase composition remained constant for 1.5 h. After polymerization, the ethylene and 1-butene feeds were stopped, the pressure was reduced, and the material was purged with nitrogen for 20 min to remove devolatilization. The bed material was then discharged to obtain comparative vinyl elastomer powder. The powder was then subjected to devolatilization extrusion and granulation at 190 °C using a twin-screw extruder to obtain granular vinyl elastomer sample D2. The analytical and characterization results are shown in Table 1.

[0054] Table 1. Characterization results of vinyl elastomers using solution method

[0055] As shown in Table 1, the structural and performance data reveal that introducing Si-O bond-containing structural units into the vinyl elastomer molecular chains obtained in the examples effectively constructs a structure with long-chain-like characteristics at the molecular chain level. This enhances polymer chain entanglement and stabilizes the melt network structure, resulting in higher melt strength and more significant shear thinning characteristics on a macroscopic scale. This improves melt flowability and processing stability, further enhancing the mechanical properties of the material. Taking the solution-processed sample as an example, under similar α-olefin insertion rates (e.g., approximately 12-13 mol%) in both Example 3 and Comparative Example 1, the tensile strength of Example 3 increased from approximately 12 MPa in the Comparative Example to approximately 16.8 MPa after introducing Si-O structural units. Simultaneously, the light transmittance increased from approximately 89.0% to approximately 91.5%, and the volume resistivity also increased from approximately 8.0 × 10⁻⁶. 15 The Ω·cm increased to approximately 4.1 × 10⁻⁶. 17 The result of Ω·cm indicates that the introduction of Si-O structural units can achieve a synergistic improvement in mechanical and processing properties without significantly sacrificing transparency and electrical insulation performance.

[0056] Figure 3 The rheological curves of vinyl elastomers S1 and D1 are shown, illustrating the introduction of long-branched structures in S1. Figure 4 The image shows the carbon NMR spectrum of vinyl elastomer S1. The insertion rate of α-olefins was calculated based on the NMR results.

[0057] In contrast, the comparative sample did not introduce Si-O bond-containing structural units during polymerization. Its molecular chain structure mainly consisted of short branches formed by the copolymerization of ethylene and α-olefins, lacking long-branch-like structural features. This resulted in a relatively simple melt structure, with little improvement in melt strength and shear thinning properties, thus limiting the improvement in the material's mechanical properties and processing stability. Furthermore, as can be seen from the different solution method examples in Table 1, by adjusting the types and amounts of polyvinyl compounds containing silicon-oxygen bonds, and by controlling the α-olefin insertion rate and molecular weight, the polymer's density, melting point, and melt index can be designed to vary within the target range: when the α-olefin insertion rate increases, the material density and melting point decrease while the light transmittance increases; when the molecular weight decreases, the melt index increases and processing fluidity is enhanced, thereby achieving targeted control of different performance combinations from "high melt strength / high strength" to "high fluidity / high transparency".

[0058] For vapor phase samples (such as Example 5 and Comparative Example 2), under similar process conditions, the sample of the example that introduced Si-O structural units generally exhibited higher tensile strength and higher volume resistivity.

[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing a vinyl elastomer, characterized in that, The method includes: copolymerizing ethylene monomer, α-olefin, and a polyvinyl compound containing silicon-oxygen bonds in the presence of a metallocene catalyst to obtain a vinyl elastomer, wherein the polyvinyl compound containing silicon-oxygen bonds has the general structural formula X. 1 -Si(R 1 )2-O-Si(R 2 )2-X 2 or [Si(R)] 3 (X) 3 )-O] m In the general formula, m≥3, X 1 X 2 X 3 For C2-C 20 α-olefin group, R 1 R 2 R 3 For C1-C 20 Straight-chain, branched, or isomerized alkyl or aryl groups.

2. The preparation method according to claim 1, characterized in that, The α-olefin is one or more of propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and 1-nonene.

3. The preparation method according to claim 1, characterized in that, X 1 X 2 X 3 R is an α-olefin group of C2-C6. 1 R 2 R 3 It is a straight-chain, branched, or isomerized alkyl group of C1-C3, with 3≤m≤5.

4. The preparation method according to claim 1, characterized in that, The polyvinyl compounds containing silicon-oxygen bonds are 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetraethyldisiloxane, 1,3-divinyl-1,1,3,3-tetra-n-propyldisiloxane, 1,3-divinyl-1,1,3,3-tetraisopropyldisiloxane, 1,3-diallyl-1,1,3,3-tetramethyldisiloxane, 1,3-diallyl-1,1,3,3-tetraethyldisiloxane, 1,3-diallyl-1,1,3,3-tetra-n-propyldisiloxane, 1,3-diallyl-1,1,3,3-tetraisopropyldisiloxane, 1,3-di(3-butenyl)-1,1,3,3-tetramethyldisiloxane, 1, 3-Di(3-butenyl)-1,1,3,3-tetraethyldisiloxane, 1,3-di(3-butenyl)-1,1,3,3-tetra-n-propyldisiloxane, 1,3-di(3-butenyl)-1,1,3,3-tetraisopropyldisiloxane, 1,3-di(4-pentenyl)-1,1,3,3-tetramethyldisiloxane, 1,3-di(4-pentenyl)-1,1,3,3-tetramethyldisiloxane, 1,3-di(4-pentenyl)-1,1,3,3-tetramethyldisiloxane, 1,3-Di(4-pentenyl)-1,1,3,3-tetraethyldisiloxane, 1,3-di(4-pentenyl)-1,1,3,3-tetra-n-propyldisiloxane, 1,3-di(4-pentenyl)-1,1,3,3-tetraisopropyldisiloxane, 1,3-di(5-hexenyl)-1,1,3,3-tetramethyldisiloxane, 1,3-di(5-hexenyl)-1,1 3,3-Tetraethyldisiloxane, 1,3-Di(5-hexenyl)-1,1,3,3-tetra-n-propyldisiloxane, 1,3-Di(5-hexenyl)-1,1,3,3-tetraisopropyldisiloxane, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-triethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-triallylcyclotrisiloxane, 1,3,5-triethyl-1,3,5-triallylcyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-triene propylcyclotrisiloxane, 1,3,5-triisopropyl-1,3,5-triallylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tris(3-butenyl)cyclotrisiloxane, 1,3,5-triethyl-1,3,5-tris(3-butenyl)cyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-tris(3-butenyl)cyclotrisiloxane 1,3,5-Triisopropyl-1,3,5-tris(3-butenyl)cyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tris(4-pentenyl)cyclotrisiloxane, 1,3,5-triethyl-1,3,5-tris(4-pentenyl)cyclotrisiloxane, 1,3,5-tri-n-propyl-1,3,5-tris(4-pentenyl)cyclotrisiloxane, 1,3,5-Triisopropyl-1,3,5-Tris(4-pentenyl)cyclotrisiloxane, 1,3,5-Trimethyl-1,3,5-Tris(5-hexenyl)cyclotrisiloxane, 1,3,5-Triethyl-1,3,5-Tris(5-hexenyl)cyclotrisiloxane, 1,3,5-Tri-n-propyl-1,3,5-Tris(5-hexenyl)cyclotrisiloxane, 1,3,5-Triisopropyl-1,3,5-Tris(5-hexenyl)cyclotrisiloxane, 1,3,5,7-Tetramethyl-1,3,5,7-Tetravinylcyclotetrasiloxane, 1,3,5,7-Tetraethyl-1,3,5,7-Tetravinylcyclotetrasiloxane, 1,3,5,7-Tetra-n-propyl-1,3,5,7-Tetravinylcyclotetrasiloxane, 1,3,5,7- Tetraisopropyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetraethyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetran-n-propyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetraisopropyl-1,3,5,7-tetraallypropylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra(3-butenyl)cyclotetrasiloxane, 1,3,5,7-tetraethyl-1,3,5,7-tetra(3-butenyl)cyclotetrasiloxane, 1, 3,5,7-Tetraisopropyl-1,3,5,7-Tetra(3-butenyl)cyclotetrasiloxane, 1,3,5,7-Tetramethyl-1,3,5,7-Tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5,7-Tetraethyl-1,3,5,7-Tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5,7-Tetra-n-propyl-1,3,5,7-Tetra(4-pentenyl)cyclotetrasiloxane 1,3,5,7-Tetraisopropyl-1,3,5,7-Tetra(4-pentenyl)cyclotetrasiloxane, 1,3,5,7-Tetramethyl-1,3,5,7-Tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7-Tetraethyl-1,3,5,7-Tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7-Tetra-n-propyl 1,3,5,7-Tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7-Tetraisopropyl-1,3,5,7-Tetra(5-hexenyl)cyclotetrasiloxane, 1,3,5,7,9-Pentamethyl-1,3,5,7,9-Pentavinylcyclopentasiloxane, 1,3,5,7,9-Pentaethyl-1,3,5,7,9-Pentavinylcyclopentasiloxane, 1,3,5,7,9-Pentapropyl-1,3,5,7,9-Pentavinylcyclopentasiloxane, 1,3,5,7,9-Pentaisopropyl-1,3,5,7,9-Pentavinylcyclopentasiloxane, 1,3,5,7,9-Pentamethyl-1,3,5,7,9-Pentaallypropylcyclopentasiloxane, 1,3,5,7,9-Pentaethyl-1,3,5,7,9-Pentaethyl-1,3,5,7,9-Pentamethyl-1,3,5,7,9-Pentaallypropylcyclopentasiloxane, 1,3,5,7,9-Pentaethyl-1,3,5,7,9-Pentaethyl-1,3,5,7,9-Pentavinylcyclopentasiloxane,7,9-Pentaallypropylcyclopentasiloxane, 1,3,5,7,9-Penta-n-propyl-1,3,5,7,9-Pentaallypropylcyclopentasiloxane, 1,3,5,7,9-Pentaisopropyl-1,3,5,7,9-Pentaallypropylcyclopentasiloxane, 1,3,5,7,9-Pentamethyl-1,3,5,7,9-Penta(3-Butenyl)cyclopentasiloxane, 1,3,5,7,9-Pentaethyl-1, 3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-penta(3-butenyl)cyclopentasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-Pentaethyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-penta(4-pentenyl)cyclopentasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7, One or more of the following: 9-penta(5-hexenyl)cyclopentasiloxane, 1,3,5,7,9-pentaethyl-1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane, 1,3,5,7,9-penta-n-propyl-1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane, and 1,3,5,7,9-pentaisopropyl-1,3,5,7,9-penta(5-hexenyl)cyclopentasiloxane.

5. The preparation method according to any one of claims 1-4, characterized in that, Based on the total molar number of the ethylene monomer and the α-olefin, the amount of the α-olefin is 5-40 mol%, and based on the total weight of the ethylene monomer and the α-olefin, the amount of the polyvinyl compound containing silicon-oxygen bonds is 0.001-2.0 wt%.

6. The preparation method according to any one of claims 1-4, characterized in that, Based on the total molar number of the ethylene monomer and the α-olefin, the insertion rate of the α-olefin in the vinyl elastomer is 5-35 mol%, and the insertion rate of the polyvinyl compound containing silicon-oxygen bonds is 0.0001-1.0 wt%.

7. The preparation method according to any one of claims 1-4, characterized in that, The metallocene catalyst is dissolved in an alkane or aromatic solvent and used in a solution polymerization process to produce vinyl elastomers, or the metallocene catalyst is used in a heterogeneous supported form and used in a gas-phase fluidized bed polymerization process to produce vinyl elastomers.

8. The preparation method according to claim 7, characterized in that: When producing vinyl elastomers using solution polymerization, a co-catalyst component is added. The co-catalyst component is selected from one or more of methylaluminoxane, modified methylaluminoxane, tris(pentafluorophenyl)borane, borate, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum, and the [Al] / [M] molar ratio is 10-1000, the [B] / [M] molar ratio is 0.1-100, and M is the central metal element of the metallocene catalyst. When producing vinyl elastomers using a gas-phase fluidized bed polymerization process, a co-catalyst component may be selectively added or not added. The co-catalyst component is selected from one or more of methylaluminoxane, modified methylaluminoxane, tris(pentafluorophenyl)borane, borate, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum, and the [Al] / [M] molar ratio is 10-1000, the [B] / [M] molar ratio is 0.1-100, and M is the central metal element of the metallocene catalyst. Hydrogen and antistatic agents may be selectively added or omitted during the copolymerization reaction, so that the ethylene monomer and the... α -Based on the total weight of olefins, the amount of hydrogen is 0-5.0 wt%, and the amount of antistatic agent is 0-0.05 wt%.

9. The preparation method according to any one of claims 1-4, characterized in that, The copolymerization reaction is carried out under a polymerization pressure of 0.1-5.0 MPa, a polymerization temperature of 20-200 ℃, and a polymerization residence time of 0.05-24 h.

10. The vinyl elastomer prepared by the method according to any one of claims 1-4, characterized in that, The density of the vinyl elastomer is between 0.858 and 0.900 g / cm³. 3 The vinyl elastomer has a melt index of 0.1-50 g / 10min at 190 °C and a load of 2.16 kg, a melting point of 40-100 °C, a light transmittance of 88-95%, and a volume resistivity of 1.0 × 10⁻⁶. 15 Ω·cm ~ 1.0 × 10 19 The tensile strength of the vinyl elastomer is 5-30 MPa, based on the total molar number of ethylene monomers and α-olefins, and the weight-average molecular weight of the vinyl elastomer is 5.0 × 10⁻⁶ Ω·cm. 4 -6.0×10 5 g / mol, with a molecular weight distribution of 2.0-8.0.

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