Resin composition as well as preparation method and application thereof

Abstract

The invention provides a resin composition as well as a preparation method and application thereof. The resin composition comprises a matrix phase and an elastic phase, and each of the matrix phase and the elastic phase comprises a propylene copolymer; carrying out crystallization elution grading test on the elastic phase, wherein the content of a soluble substance component is 90wt%-100wt%; carrying out crystallization elution grading test on the resin composition, wherein the content of the component with the elution temperature greater than or equal to 100 DEG C is 0.5-5wt%; a thermal gradient interaction chromatography test is carried out on the resin composition, wherein the content of a component with the leaching temperature greater than or equal to 100 DEG C is 1.5-10 wt%. The heterophase propenyl resin obtained by the invention has excellent performance, and especially shows excellent shear thinning characteristic during high-speed processing. In the structure, the compatibility of an elastic phase and a matrix is improved, polymer long-chain entanglement is optimized, and a phase interface is remarkably strengthened, so that cracks are effectively restrained, and the composite material is suitable for being used as a high-performance coating material.

Description

Technical Field

[0001] This invention relates to the field of plastics, and more specifically, to a resin composition, its preparation method, and its application. Background Technology

[0002] In today's industrial society, steel wire rope, as an indispensable basic material, is widely used in various fields such as port machinery, oil drilling, and mining. It not only bears enormous weight but also endures repeated stress tests under various extreme conditions, such as intense sunlight, continuous wind and rain erosion, contact with corrosive chemicals, and extremely high temperature variations. These harsh environmental factors accelerate the aging process of steel wire rope, reducing its service life and consequently affecting the safety and efficiency of the entire system. Traditional steel wire rope structures are woven from multiple strands of steel wire. While this structure ensures high strength and load-bearing capacity, it also introduces a significant problem—direct contact and friction between the wires. During use, the tensile stress experienced by the steel wire rope when lifting heavy objects, the bending stress encountered when passing over pulleys, and the longitudinal and lateral vibrations generated when bearing dynamic loads all exacerbate wear between the wires, shortening the overall lifespan of the steel wire rope. Therefore, how to reduce wear between the wires and improve its resistance to environmental stress cracking while maintaining the original mechanical properties of the steel wire rope has become a hot research topic in the industry.

[0003] To address the aforementioned problems, besides improving the performance of the wire rope itself to extend its service life, another important method is to develop and manufacture solid polymer coatings for wire ropes. Polymer materials forcibly isolate the strands, maintaining a reasonable gap between them and reducing friction caused by mutual compression and sliding during load-bearing. This also reduces the impact of impact and vibration loads on the wire rope's service life. However, traditionally, solid polymer coatings are often produced by heating and melting polymer components in an extruder or internal mixer, followed by physical mixing and extrusion. This process makes it difficult to ensure uniform mixing of different polymer components, especially when there are significant differences in the melt viscosity of each component. This often leads to unstable performance of the mixed material, resulting in decreased wear resistance, coating peeling, or cracking during long-term use. These problems severely affect the reliability and service life of the wire rope.

[0004] To address the aforementioned drawbacks of mechanical blending, in-situ polymer blending can be used to prepare coating materials, especially for polyolefin resins. This technique allows the elastic phase to be mixed with the crystalline phase through in-situ multi-stage polymerization to obtain a multiphase polymer system. However, multiphase systems with a rigid crystalline matrix and dispersed soft elastic phases or core-shell particles are sensitive to stress whitening, which can cause stress cracking of coated wire ropes under repeated operation. Furthermore, for solid polymers used in wire ropes, a balance between toughness and stiffness is also required.

[0005] Meanwhile, modern industry demands ever-increasing production efficiency, meaning that the wire rope coating process also needs to be able to adapt to processing conditions with higher extrusion speeds. However, high-speed processing conditions place more stringent requirements on the coating materials. On the one hand, the material needs to have good processing fluidity to ensure that the integrity and surface quality of the coating layer are maintained during high-speed extrusion; on the other hand, the physical and mechanical properties of the material also need to be sufficiently stable to prevent excessive viscoelastic deformation or mold expansion under high-speed processing, which could lead to irregular ripples on the surface of the coating layer, affecting its appearance and function.

[0006] Faced with these challenges, the industry has been seeking breakthroughs, aiming to develop a new solid polymer coating material. CN113056508B discloses a polypropylene composition comprising propylene homopolymer (H-PP) and a propylene copolymer of propylene and 1-hexene. By introducing a specific polypropylene copolymer as a modifier into the polypropylene homopolymer composition, good impact resistance and optical properties are provided. However, this technical solution uses polypropylene homopolymer as the matrix, which reduces melt flow and crystallization rate under high-speed processing, easily causing an uneven extruded surface. Simultaneously, the low compatibility between the polypropylene homopolymer and the propylene copolymer can lead to debonding at the phase interface, resulting in decreased resistance to environmental stress cracking. CN101084268B discloses a PP composition that attempts to simultaneously solve the problems of low stiffness, high impact resistance, and high resistance to whitening through a specific composition. However, in this patent, high-density polyethylene is used as a modifier to reduce stress whitening in the polypropylene multiphase copolymer material. However, this inevitably leads to a decrease in the toughness of the resulting material, thereby disrupting the balance between stiffness and toughness. CN1225501C discloses a polyolefin composition with good impact strength and transparency, which reduces stress whitening in polypropylene by modifying the multiphase polymer system with low-density polyethylene (LDPE) as a modifier. However, the addition of LDPE has two drawbacks: first, it leads to incompatibility with the multiphase polymer, causing phase separation and resulting in more pronounced stress cracking due to interfacial detachment; second, it limits the rigidity of the resulting composition, thus disrupting the balance between rigidity and toughness and hindering industrial applications.

[0007] Therefore, how to design and prepare a resin composition with suitable rheological properties and good rigidity and toughness, so that it can not only meet the needs of high-speed processing, but also serve as a coating material to exhibit excellent environmental stress cracking resistance and rigidity-toughness balance in complex use environments, is one of the important technical problems to be solved in this field. Summary of the Invention

[0008] The main objective of this invention is to provide a resin composition, its preparation method, and its application, in order to solve the problems in the prior art where resin compositions are difficult to balance good rigidity and toughness, and have poor rheological properties, making them difficult to adapt to high-speed processing when used as coating materials, and easily causing problems such as rigidity-toughness imbalance, stress whitening, and stress cracking.

[0009] To achieve the above objectives, a first aspect of the present invention provides a resin composition comprising a matrix phase and an elastic phase, both of which comprise a propylene copolymer; the characteristic viscosity of the elastic phase is 1.0 dl / g to 2.5 dl / g; a crystallization elution fractionation test is performed on the elastic phase, and the content of the soluble component in the elastic phase is 90 wt% to 100 wt%; a crystallization elution fractionation test is performed on the resin composition, and the content of the component with an elution temperature ≥100°C is 0.5 wt% to 5 wt%; a thermal gradient interaction chromatography test is performed on the resin composition, and the content of the component with an elution temperature ≥100°C is 1.5 wt% to 10 wt%; in the Cross rheological model, the non-Newtonian index n of the resin composition is 0.40 to 0.60, and the relaxation time λ is 3 s to 7 s.

[0010] Further, the characteristic viscosity of the elastic phase is 1.5 dl / g to 2.0 dl / g; and / or, in the crystallization elution fractionation test of the elastic phase, the content of the soluble component in the elastic phase is 92 wt% to 96 wt%; and / or, in the crystallization elution fractionation test of the resin composition, the content of the component with an elution temperature ≥100℃ in the resin composition is 0.5 wt% to 2 wt%; and / or, in the thermal gradient interaction chromatography test of the resin composition, the content of the component with an elution temperature ≥100℃ in the resin composition is 2 wt% to 6 wt%; and / or, the non-Newtonian index n of the resin composition is 0.45 to 0.55, and the relaxation time λ is 5 s to 7 s.

[0011] Furthermore, the Z-average molecular weight M of the resin composition z With weight-average molecular weight M w Satisfy: 4.5≤M z / M w ≤5.5, preferably 5.0≤M z / M w≤5.4; and / or, on the molecular weight integral distribution curve, lg(M90) and lg(M50) of the resin composition satisfy: 1.10≤lg(M90) / lg(M50)≤1.15; and / or, on the molecular weight integral distribution curve, lg(M50) and lg(M10) of the resin composition satisfy: 1.20≤lg(M50) / lg(M10)≤1.25.

[0012] Furthermore, the resin composition further includes an antioxidant and / or a nucleating agent; preferably, the antioxidant content is 0.01% to 1% based on 100% of the total weight of the resin composition, more preferably 0.1% to 0.5%; and / or, the nucleating agent content is 0.001% to 5% based on 100% of the total weight of the resin composition, more preferably 0.01% to 3%.

[0013] Furthermore, the tensile strength of the resin composition is 25 MPa to 50 MPa, preferably 30 MPa to 40 MPa.

[0014] Furthermore, the tensile fracture strain of the resin composition is 450% to 800%, preferably 600% to 700%.

[0015] Furthermore, the resin composition has an impact strength of 40 kJ / m at -20°C. 2 ~70kJ / m 2 The preferred value is 50 kJ / m 2 ~60kJ / m 2 .

[0016] Furthermore, the environmental stress cracking resistance time of the resin composition is 500h to 1000h, preferably 800h to 1000h.

[0017] A second aspect of the present invention provides a method for preparing the above-mentioned resin composition, comprising: step S1, propylene, hydrogen and a first comonomer undergoing a first polymerization reaction to obtain a matrix phase; the ratio of hydrogen to propylene is 2.0 mol / kmol to 5.0 mol / kmol, and the ratio of the first comonomer to propylene is 4.7 mol / kmol to 9.6 mol / kmol; step S2, the matrix phase, propylene and a second comonomer undergoing a second polymerization reaction to form an elastic phase in the matrix phase, thereby obtaining a polymer product; the weight ratio of propylene to the second comonomer is (1.0 to 2.5):1; step S3, optionally adding an antioxidant to the polymer product, and then melt-extruding and granulating to obtain a resin composition; wherein the weight ratio of propylene in step S1 to propylene in step S2 is 100:(5 to 12).

[0018] Further, the first comonomer and the second comonomer are each independently selected from one or more α-olefins, and neither the first comonomer nor the second comonomer includes propylene; preferably, the first comonomer and the second comonomer are each independently selected from one or more of ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene and 1-octene; more preferably, the first comonomer and the second comonomer are each independently ethylene and / or 1-butene.

[0019] Furthermore, both the first comonomer and the second comonomer are ethylene, and: in step S1, the ratio of hydrogen to propylene is 2.0 mol / kmol to 3.0 mol / kmol, and the ratio of ethylene to propylene is 4.7 mol / kmol to 6.1 mol / kmol; in step S2, the weight ratio of propylene to ethylene is (2.0 to 2.38):1.

[0020] Furthermore, both the first and second comonomers are 1-butene, and: in step S1, the ratio of hydrogen to propylene is 2.4 mol / kmol to 5.0 mol / kmol, and the ratio of 1-butene to propylene is 9.0 mol / kmol to 9.6 mol / kmol; in step S2, the weight ratio of propylene to 1-butene is (1.0 to 1.55):1.

[0021] Further, the reaction temperature of the first polymerization reaction is 65℃~85℃, the reaction pressure is 1.50MPa~8.0MPa, and the reaction time is 20min~80min; and / or, the reaction temperature of the second polymerization reaction is 75℃~95℃, the reaction pressure is 0.5~5.0MPa, and the reaction time is 70min~200min; preferably, the reaction temperature of the first polymerization reaction is 68℃~80℃, the reaction pressure is 2.0MPa~6.0MPa, and the reaction time is 30min~60min; and / or, the reaction temperature of the second polymerization reaction is 78℃~90℃, the reaction pressure is 1.5MPa~3.5MPa, and the reaction time is 90min~180min.

[0022] A third aspect of the invention provides the application of the above-described resin composition as a coating material on the surface of metal wires or metal pipes used in the shipbuilding, aerospace, construction, drilling, or machinery industries.

[0023] Furthermore, at 190°C to 230°C, the resin composition is extruded and coated onto the surface of the metal wire or metal pipe to form a coating material.

[0024] The present invention provides a resin composition with superior physicochemical properties, especially rheological properties. The resulting multiphase propylene-based resin composition exhibits higher shear thinning at higher screw speeds, thus demonstrating exceptional flowability under high-speed processing. Simultaneously, by controlling the elastic phase component, its compatibility with the matrix phase is improved, avoiding excessive viscoelastic deformation that could lead to irregular surface ripples during subsequent use. Furthermore, the resulting resin composition significantly improves the long-chain entanglement of the polymer and the connectivity between different phase interfaces; intergranular region connectivity, amorphous region entanglement, and interphase interface connectivity are all effectively enhanced, thereby enabling it to function as a coating material to inhibit crack initiation or propagation. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0026] As described in the background art, existing resin compositions suffer from the problem of difficulty in achieving both good rigidity and toughness, as well as poor rheological properties. Consequently, they are difficult to adapt to high-speed processing when used as coating materials, and are prone to problems such as rigidity-toughness imbalance, stress whitening, and stress cracking. To address the aforementioned technical problems, a first aspect of the present invention provides a resin composition comprising a matrix phase and an elastic phase, both of which include a propylene copolymer; the characteristic viscosity of the elastic phase is 1.0 dl / g to 2.5 dl / g; a crystallization elution fractionation test is performed on the elastic phase, and the content of the soluble component in the elastic phase is 90 wt% to 100 wt%; a crystallization elution fractionation test is performed on the resin composition, and the content of the component with an elution temperature ≥100°C is 0.5 wt% to 5 wt%; a thermal gradient interaction chromatography test is performed on the resin composition, and the content of the component with an elution temperature ≥100°C is 1.5 wt% to 10 wt%; in the Cross rheological model, the non-Newtonian index n of the resin composition is 0.40 to 0.60, and the relaxation time λ is 3 s to 7 s.

[0027] To avoid ambiguity, the above-mentioned physical characteristic parameters of the present invention are specifically as follows:

[0028] Crystallization-elution fractionation (CEF) involves two temperature cycles, heating and cooling, similar to temperature-elution fractionation (TREF). However, unlike TREF, in CEF, a small amount of solvent is pumped through the column during the cooling crystallization process. When the crystallization temperature of one fraction is reached, it is separated and deposited on the column, while other fractions remain soluble in the solvent and move along the column until they reach their crystallization temperature and are separated. Therefore, CEF minimizes co-crystallization effects by separating fractions with different crystallization properties within the column.

[0029] Thermal gradient interaction chromatography (TGIC) is a chromatographic technique based on temperature gradients. Its main applications include the analysis of special polyolefin resins or components such as propylene multiphase copolymers, polyolefin elastomers, and olefin block copolymers. By controlling the temperature gradient, TGIC technology enables the separation and quantitative analysis of different components in insulating materials, thereby allowing for the evaluation of their performance. TGIC utilizes the combined effects of adsorption / desorption of polyolefin chains with the TGIC column, as well as crystallization properties, to achieve the separation and characterization of different components of polyolefins under specific solvent flow rates and temperature variations. In particular, it can analyze non-crystalline fractions that are inaccessible by crystallization fractionation techniques.

[0030] The Cross rheological model can comprehensively describe the inflection point of the "S"-shaped flow curve, and is therefore often used in the petrochemical field, especially for the rheological properties of thermoplastic materials such as asphalt. Its model formula is as follows.

[0031]

[0032] Wherein, the power-law exponent n is the flow behavior exponent or non-Newtonian exponent; λ is the relaxation time, which refers to the time required for the material to return to its normal state after being deformed by stress and the external force is removed; η0 is the zero-shear viscosity or first Newtonian viscosity. That is the shear rate.

[0033] The resin composition provided by this invention not only possesses superior rheological properties, but also significantly enhanced high-speed processing capability and resistance to environmental stress cracking. Specifically:

[0034] Firstly, the characteristic viscosity of the elastic phase is controlled: This invention limits the characteristic viscosity of the elastic phase to between 1.0 dl / g and 2.5 dl / g, ensuring that the elastic phase can be uniformly dispersed in the matrix phase, avoiding the formation of large particles, thereby reducing mold expansion and ensuring surface quality under high-speed processing. Appropriate viscosity also implies suitable softness of the elastic phase, which helps improve the toughness of the material without sacrificing its overall rigidity.

[0035] Secondly, the elastic phase has a high content of soluble components: the content of soluble components in the elastic phase is as high as 90wt% to 100wt%. This characteristic indicates that the elastic phase has extremely high molecular chain flexibility, which is beneficial to improving the material's resistance to environmental stress, reducing cracking caused by stress concentration, and maintaining good elastic recovery performance.

[0036] Thirdly, the crystallization elution and classification results of the resin composition: In the resin composition of the present invention, the content of the component with a elution temperature ≥100℃ is controlled at 0.5wt% to 5wt%, which reflects that the resin composition has good crystallization performance under high-speed processing environment, thereby ensuring that the material can maintain a stable structure at high temperature, preventing excessive melt flow during processing, and ensuring the consistency and stability of the final product quality.

[0037] Fourth, the results of thermal gradient interaction chromatography of the resin composition showed that the components with elution temperatures ≥100℃ were 1.5wt% to 10wt%. This indicator reveals the good compatibility and structural continuity between different components within the material, which helps maintain the overall toughness of the material. At the same time, through appropriate viscoelastic property adjustment, the high-speed processing adaptability of the material is further enhanced.

[0038] Fifth, the Cross rheological model parameters are: non-Newtonian index n is 0.40 to 0.60, and relaxation time λ is 3s to 7s. This rheological property setting allows the material to exhibit good shear thinning behavior, that is, the viscosity decreases with the increase of shear rate. This ensures that the resin composition has excellent flowability and processing performance during high-speed extrusion, while avoiding the defects caused by premature curing of elastomers, such as uneven surface and difficulty in demolding.

[0039] In summary, the multiphase acrylic resin composition obtained by this invention exhibits higher shear thinning properties at higher screw speeds, thus demonstrating superior flowability under high-speed processing. Simultaneously, by controlling the elastic phase component, its compatibility with the matrix phase is improved, avoiding excessive viscoelastic deformation that could lead to irregular surface ripples during subsequent use. Furthermore, the resulting resin composition structure significantly improves the long-chain entanglement of the polymer and the connectivity between different phase interfaces; intercrystalline region connectivity, amorphous region entanglement, and interphase interface connectivity are all effectively enhanced, thereby enabling it to function as a coating material to suppress crack initiation or propagation.

[0040] Based on the above, the present invention further preferably includes the following: the characteristic viscosity of the elastic phase is 1.5 dl / g to 2.0 dl / g; and / or, in the crystallization elution classification test of the elastic phase, the content of the soluble component in the elastic phase is 92 wt% to 96 wt%; and / or, in the crystallization elution classification test of the resin composition, the content of the component with an elution temperature ≥100°C in the resin composition is 0.5 wt% to 2 wt%; and / or, in the thermal gradient interaction chromatography test of the resin composition, the content of the component with an elution temperature ≥100°C in the resin composition is 2 wt% to 6 wt%; and / or, the non-Newtonian index n of the resin composition is 0.45 to 0.55, and the relaxation time λ is 5 s to 7 s. By more precisely optimizing the above parameters, the rigidity and toughness of the obtained resin composition can be more accurately balanced, so that while maintaining good toughness, it has better extrusion surface smoothness and reduces surface defects that may occur during high-speed processing. At the same time, it significantly improves its response speed and recovery ability to shear force under high-speed processing conditions, thereby more effectively reducing the internal stress generated during high-speed processing.

[0041] Polymers are long chains formed by chemical bonds of repeating units (monomers). Unlike low-molecular-weight compounds, polymers do not have a fixed molecular weight; instead, they are mixtures of homologues with different molecular weights. Therefore, polymer molecular weight is an average value, a concept of distribution. The chain length of a polymer is usually expressed as the molecular weight of the polymer chain, which is related to the relative molecular weight of the monomers and the number of monomers in the chain. However, all synthetic polymers are polydisperse, containing polymer chains of varying lengths, so the molecular weight of a polymer is not a single value—but a range of polymer chain lengths and molecular weights. Therefore, the molecular weight of a polymer must be described by calculating the average molecular weight of all polymer chains in the sample. Where M... z Z-mean molecular weight is a method for calculating average molecular weight. Its calculation formula is M... z =Σ(Ni×Mi 3 ) / ΣNi Mi 2 , where N i Indicates a molecular weight of M i The number of polymer molecules present in the sample.

[0042] In several preferred embodiments, the preferred resin composition has a Z-average molecular weight M. z With weight-average molecular weight M w Satisfy: 4.5≤M z / M w ≤5.5, more preferably 5.0≤M z / M w ≤5.4, thereby more effectively improving the fluidity and molding stability of the resulting resin composition during processing.

[0043] The relative molecular mass integral distribution curve is obtained by integrating the molecular weight distribution curve. The ratio of relative molecular masses at I(M) = 90%, I(M) = 50%, and I(M) = 10% is used as the distribution width index. Three relative molecular mass values ​​are taken on the curve: lg(M10), lg(M50), and lg(M90), with subscripts indicating mass fractions. lg(M10) indicates that 10% of the sample mass has a relative molecular mass below M10; lg(M50) indicates that 50% of the sample mass has a relative molecular mass below M50; and lg(M90) indicates that 90% of the sample mass has a relative molecular mass below M90.

[0044] In this invention, lg(M90) / lg(M50) represents the distribution width of the high molecular weight portion, and lg(M50) / lg(M10) represents the distribution width of the low molecular weight portion. Based on this, in several preferred embodiments: on the molecular weight integral distribution curve, lg(M90) and lg(M50) of the resin composition satisfy: 1.10 ≤ lg(M90) / lg(M50) ≤ 1.15; and / or, on the molecular weight integral distribution curve, lg(M50) and lg(M10) of the resin composition satisfy: 1.20 ≤ lg(M50) / lg(M10) ≤ 1.25. This is because the inventors, through extensive experiments, discovered that in M... z / M w Based on this, simultaneously optimizing the ratios of lg(M90) / lg(M50) and lg(M50) / lg(M10) further improves the balance between high-speed workability and environmental cracking resistance. Furthermore, by adjusting these three ratios (M... z / M w The ratios of lg(M90) / lg(M50) and lg(M50) / lg(M10) are set within specific ranges, which not only improves the extrusion die expansion and allows the molten polymer to make smooth contact with the wire rope surface during extrusion coating, so that the wire rope coating layer formed by the resin composition of the present invention has good surface smoothness, but also allows the resin composition of the present invention to have excellent flowability and can be processed and produced at high speed.

[0045] In several more preferred embodiments, 1.13≤lg(M90) / lg(M50)≤1.15; 1.22≤lg(M50) / lg(M10)≤1.25, thereby enabling the resulting resin composition to have both high fluidity under high-speed processing conditions and more complete curing in a short time, thus obtaining a coating material with a smoother surface.

[0046] To further improve the long-term stability and weather resistance of the obtained resin composition as a coating material under various environmental conditions, it is further preferred that the resin composition also includes an antioxidant and / or a nucleating agent; and preferably, the content of the antioxidant is 0.01% to 1%, more preferably 0.1% to 0.5%, based on 100% of the total weight of the resin composition; and / or, the content of the nucleating agent is 0.001% to 5%, more preferably 0.01% to 3%, based on 100% of the total weight of the resin composition.

[0047] Antioxidants, preferably selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-( One or more of the following: 1H,3H,5H)-trione, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, N,N-bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, octadecyl 3,3-thiodipropionate and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, but not limited to the types listed herein.

[0048] Nucleating agents can be added to the resin composition either as a separate raw material or in the form of a mixture with the carrier polymer, i.e., as a masterbatch. During the crystallization process of the resin composition, nucleating agents can reduce the grain size in the crystalline phase, further improving the mechanical properties of the material. Preferably, the nucleating agent is selected from one or more of carboxylates, substituted or unsubstituted dibenzylidene sorbitols, substituted or unsubstituted nonitols, phosphates, vinyl cycloalkane polymers, and vinyl alkane polymers. Specifically, it can be (i) carboxylate compounds, such as salts of monocarboxylic and polycarboxylic acids, for example, sodium benzoate or aluminum tert-butylbenzoate, and (ii) unsubstituted dibenzyl sorbitol (e.g., 1,3:2,4-dibenzyl sorbitol) and C1-C8 alkyl-substituted dibenzyl sorbitol derivatives, such as methyl dibenzyl sorbitol, ethyl dibenzyl sorbitol, or dimethyl dibenzyl sorbitol (e.g., 1,3:2,4-di(methylbenzyl)sorbitol), or substituted nonitol derivatives, such as... 1,2,3-Trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol, and (iii) salts of phosphate diesters, such as sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate or bis[2,2'-methylene-bis(4,6-di-tert-butylphenyl)phosphate]hydroxyaluminum, or referred to as 2,2'-methylene-bis(4,6-di-tert-butylphenyl)phosphate basic aluminum), and (iv) vinylcycloalkane polymers and vinylalkane polymers and (v) mixtures of the above, but not limited to the types mentioned above.

[0049] In several preferred embodiments, the antioxidant is a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl) phosphite, wherein the weight ratio of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] to tris(2,4-di-tert-butylphenyl) phosphite in the mixture is (0.8-1.2):(0.8-1.2).

[0050] Furthermore, in practical applications, to further enhance various application performances, the resin composition provided by this invention may also include inorganic fillers. Inorganic fillers can improve mechanical properties, and are preferably mineral fillers, including layered silicates, mica, or wollastonite. Mica, wollastonite, kaolin, montmorillonite, and talc are preferred, and talc and wollastonite are more preferred. Meanwhile, regarding the inorganic filler, in use, its median particle size (D50) is in the range of 1.0 to 10.0 μm, and its maximum particle size (D95) is in the range of 3.0 to 20.0 μm; more preferably, the median particle size (D50) is in the range of 3.0 to 5.0 μm, and the maximum particle size (D95) is in the range of 7.0 to 13.0 μm.

[0051] In several preferred embodiments, the tensile strength of the resin composition is 25 MPa to 50 MPa, preferably 30 MPa to 40 MPa; and / or, the tensile fracture strain of the resin composition is 450% to 800%, preferably 600% to 700%; and / or, the impact strength of the resin composition at -20°C is 40 kJ / m. 2 ~70kJ / m 2 The preferred value is 50 kJ / m 2 ~60kJ / m 2 And / or, the environmental stress cracking resistance time of the resin composition is 500h to 1000h, preferably 800h to 1000h. The optimization of the tensile strength range ensures that the resulting resin composition material possesses sufficient strength to withstand the complex stress states of wire ropes in actual operation, such as tensile and bending stresses, while maintaining good toughness and avoiding brittle fracture under sudden loads. The optimization of the tensile fracture strain range reflects the continued integrity of the resin composition material obtained by this invention under large deformations, meaning that it can better adapt to dynamically changing stress conditions in high-speed processing and actual use, reducing the possibility of fatigue damage. The improved impact strength indicates that the resin composition material obtained by this invention maintains high toughness even in low-temperature environments, which is particularly important for wire ropes operating in cold or extreme climatic conditions. The progressively optimized extended environmental stress cracking resistance time contributes to the durability of the resin composition obtained by this invention as a coating layer, reducing maintenance and replacement costs and extending its service life in harsh environments.

[0052] A second aspect of the present invention provides a method for preparing the above-mentioned resin composition, comprising: step S1, propylene, hydrogen and a first comonomer undergoing a first polymerization reaction to obtain a matrix phase; the ratio of hydrogen to propylene is 2.0 mol / kmol to 5.0 mol / kmol, and the ratio of the first comonomer to propylene is 4.7 mol / kmol to 9.6 mol / kmol; step S2, the matrix phase, propylene and a second comonomer undergoing a second polymerization reaction to form an elastic phase in the matrix phase, thereby obtaining a polymer product; the weight ratio of propylene to the second comonomer is (1.0 to 2.5):1; step S3, optionally adding an antioxidant to the polymer product, and then melt-extruding and granulating to obtain a resin composition; wherein the weight ratio of propylene in step S1 to propylene in step S2 is 100:(5 to 12).

[0053] Accordingly, the present invention provides a method for preparing the above-mentioned resin composition, comprising a two-step polymerization reaction.

[0054] It should be noted in advance that hydrogen is introduced in the actual preparation process to control the molecular weight, i.e., the melt mass flow rate (MFR).

[0055] In the first-step polymerization process, by controlling the hydrogen / propylene ratio between 2.0 mol / kmol and 5.0 mol / kmol, and the ratio of the first comonomer (such as ethylene or 1-butene) to propylene between 4.7 mol / kmol and 9.6 mol / kmol, the molecular weight and distribution of the polymer can be effectively adjusted in the first-step polymerization reaction. A more suitable hydrogen / propylene ratio is beneficial for reducing melt viscosity and facilitating high-speed processing; while an appropriate first comonomer ratio can adjust the stiffness-toughness balance of the material. By introducing appropriate flexible segments into the matrix phase, both good rigidity and improved toughness are ensured.

[0056] In the second polymerization step, by setting the weight ratio of propylene to the second comonomer within the range of (1.0 to 2.5):1, an elastic phase can be formed in the matrix phase, thereby optimizing the microstructure of the multiphase resin composition. This optimized microstructure improves the material's resistance to environmental stress cracking and impact resistance. Simultaneously, because the size and distribution of the elastic phase are controlled, mold swell during high-speed processing is reduced, achieving a smooth surface and close adhesion to the substrate for the resulting resin composition as a coating material.

[0057] Furthermore, to improve the overall phase purity and compatibility of the polymer comprising the matrix phase and the elastic phase, it is preferable that the first comonomer and the second comonomer are each independently selected from one or more α-olefins, and neither the first comonomer nor the second comonomer includes propylene; more preferably, the first comonomer and the second comonomer are each independently selected from one or more of ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene; even more preferably, the first comonomer and the second comonomer are each independently ethylene and / or 1-butene. In fact, the monomers used for copolymerization are not limited to the above types, but when ethylene and / or 1-butene are used as comonomers, their better compatibility with propylene can be utilized to further strengthen the interfacial bonding between the phases, thereby further improving the overall performance of the resulting resin composition, especially the balance of rigidity and toughness and resistance to environmental stress cracking.

[0058] In several typical embodiments, both the first and second comonomers are ethylene, and: in step S1, the ratio of hydrogen to propylene is 2.0 mol / kmol to 3.0 mol / kmol, and the ratio of ethylene to propylene is 4.7 mol / kmol to 6.1 mol / kmol; in step S2, the weight ratio of propylene to ethylene is (2.0 to 2.38):1. In this scheme, both the matrix phase and the elastic phase are propylene-ethylene copolymers. A moderate ethylene content can increase the toughness of the material, while maintaining a certain propylene content enhances the rigidity of the matrix phase. Therefore, the resulting resin composition material, when subjected to tensile stress, flexural stress, and environmental stress, will not fracture prematurely and will maintain good deformation recovery ability. More importantly, by preferably setting the hydrogen / propylene ratio to 2.0 mol / kmol to 3.0 mol / kmol and the ethylene / propylene ratio to 4.7 mol / kmol to 6.1 mol / kmol in the first polymerization reaction, a propylene-ethylene copolymer with moderately short branches can be formed as the matrix phase. This facilitates increased molecular chain entanglement, thereby improving the toughness of the material while ensuring that the rigidity of the matrix phase is not weakened. A preferred propylene to ethylene weight ratio of (2.0–2.38):1 allows for the formation of more uniformly dispersed elastic phase particles in the matrix phase, thereby more effectively absorbing stress, reducing crack formation and propagation, facilitating melt flow during high-speed processing, reducing mold expansion, and improving the surface quality of the coating layer.

[0059] In several other typical embodiments, both the first and second comonomers are 1-butene, and: in step S1, the ratio of hydrogen to propylene is 2.4 mol / kmol to 5.0 mol / kmol, and the ratio of 1-butene to propylene is 9.0 mol / kmol to 9.6 mol / kmol; in step S2, the weight ratio of propylene to 1-butene is (1.0 to 1.55):1. In this scheme, both the matrix phase and the elastic phase are propylene-butene copolymers, wherein 1-butene, as a comonomer, can effectively improve the impact strength and low-temperature toughness of the polymer, enabling it to maintain good performance under cold conditions. Based on this, in the first polymerization reaction, it is preferable that the ratio of hydrogen to propylene is between 2.4 mol / kmol and 5.0 mol / kmol. This higher hydrogen / propylene ratio can increase the number of chain transfers and more effectively regulate the molecular weight and branching degree of the polymer. Furthermore, in the first polymerization reaction, the ratio of 1-butene to propylene is preferably 9.0 mol / kmol to 9.6 mol / kmol, and in the second polymerization reaction, the weight ratio of propylene to 1-butene is preferably (1.0 to 1.55):1. This helps to introduce a more suitable amount of flexible segments into the matrix phase, thereby more significantly balancing the rigidity and toughness of the material, and also improving the stress cracking resistance and dimensional stability of the resulting resin composition material under high-speed processing.

[0060] In the above polymerization process, in order to form a matrix phase with better mechanical properties and processing fluidity, the preferred reaction temperature for the first polymerization reaction is 65℃~85℃, the preferred reaction pressure is 1.50MPa~8.0MPa, and the preferred reaction time is 20min~80min. Furthermore, in order to further refine the structure of the subsequently formed dispersed phase, reduce its size, and improve its compatibility with the matrix phase, the preferred reaction temperature for the second polymerization reaction is 75℃~95℃, the preferred reaction pressure is 0.5~5.0MPa, and the preferred reaction time is 70min~200min.

[0061] Furthermore, the reaction temperature of the first polymerization reaction is 68℃~80℃, the reaction pressure is 2.0MPa~6.0MPa, and the reaction time is 30min~60min; and / or, the reaction temperature of the second polymerization reaction is 78℃~90℃, the reaction pressure is 1.5MPa~3.5MPa, and the reaction time is 90min~180min. This more precise optimization of the process parameters for the two-step polymerization reaction can further improve the overall physicochemical properties of the resulting resin composition, including but not limited to rheological properties, rigidity, toughness, resistance to environmental stress cracking, and surface quality under high-speed processing. Simultaneously, it more effectively reduces unnecessary side reactions during the reaction process and improves the uniformity of the product.

[0062] In several particularly typical embodiments, the reaction temperature of the first polymerization reaction is 73℃~77℃, and the reaction pressure is 4.4MPa~5.2MPa; the reaction temperature of the second polymerization reaction is 83℃~85℃, and the reaction pressure is 1.8MPa~3.5MPa. Specifically, in the first polymerization stage of forming the propylene homopolymer matrix phase, the preferred temperature range of 73℃~77℃ can more effectively maintain a good polymerization rate while promoting the orderly insertion polymerization of propylene monomers, resulting in a matrix phase with excellent properties; the reaction pressure range of 4.4MPa~5.2MPa can more effectively balance molecular weight and polymerization rate, avoiding poor processing flowability due to excessively high molecular weight or decreased mechanical properties due to excessively low molecular weight. In the second polymerization stage, which forms the elastic phase of the propylene-butene copolymer, a temperature range of 83°C to 85°C is more favorable for the insertion of 1-butene, effectively promoting the copolymerization of propylene and 1-butene to form a copolymer with higher flexibility as the elastic phase. A pressure range of 1.8 MPa to 3.5 MPa helps control the 1-butene content and the degree of branching of the copolymer, ensuring the final polymer has appropriate elasticity without losing excessive rigidity. In particular, by holistically optimizing the condition parameters of the two polymerization stages, forming a highly crystalline propylene homopolymer in the first stage and a propylene-butene copolymer with superior elasticity in the second stage, a better balance between rigidity and toughness in the resulting resin composition can be achieved more significantly. This is especially important for wire rope coatings that withstand complex loads.

[0063] In practical applications, the first and second polymerization reactions described above can be carried out in polymerization reactors commonly used in the art. Specifically, through sequential polymerization technology, in a polymerization system formed by at least two polymerization reactors connected in series (which may actually include a first polymerization reactor, a second polymerization reactor, an optional third polymerization reactor, and a further optional fourth polymerization reactor), a matrix phase is prepared in the first polymerization reactor, the generated matrix phase is transferred to the second polymerization reactor, where an elastic phase is generated, thereby obtaining the polymerization product.

[0064] For the catalyst used in the above polymerization reaction, a Ziegler-Natta (ZN) catalyst for preparing multiphase polypropylene compositions can be selected. This Ziegler-Natta (ZN) catalyst can be any Ziegler-Natta (ZN) catalyst used for propylene polymerization, capable of catalyzing the homopolymerization and copolymerization of propylene and / or comonomers under pressure conditions of 0.5 to 10 MPa and temperature conditions of 40 to 110 °C.

[0065] Specifically, the Ziegler-Natta (ZN) catalyst comprises compounds of transition metals from Groups 4 to 6 of the IUPAC, a Group 2 metal compound, and an internal electron donor. The internal electron donor is selected from succinates, diethers, phthalates, or mixtures thereof; and / or, the Group 2 metal is magnesium, and the magnesium compound is selected from dialkylmagnesium, alkylalkoxymagnesium, diekoxymagnesium, alkoxymagnesium halide, and alkylhalides, wherein the alkyl group can be similar or different C1-C20 alkyl groups, preferably C2-C10 alkyl groups. The transition metal compound from Groups 4 to 6 is preferably a titanium compound, preferably a titanium halide such as TiCl4.

[0066] Furthermore, during the polymerization process, the Ziegler-Natta catalyst (ZN) is used in conjunction with a co-catalyst and an external electron donor.

[0067] External electron donors include certain silanes, ethers, esters, amines, ketones, heterocyclic compounds, and blends thereof, with silanes being preferred. The silane is selected from one or more of tetramethoxysilane, tetraethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyl tert-butyldimethoxysilane, methyl isopropyldimethoxysilane, diphenoxydimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, 2-ethylpiperidinyl-2-tert-butyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-2-ethylpiperidinyldimethoxysilane, and (1,1,1-trifluoro-2-propyl)-methyldimethoxysilane. The cocatalyst is preferably a compound from Group 13 of the periodic table (IUPAC), and more preferably an organoaluminum compound selected from alkylaluminum, aluminum halide, or alkylaluminum halide compounds. More preferably, it is one or more of triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, diethylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, and di-n-hexylaluminum chloride.

[0068] When used, the molar ratio of the co-catalyst to the external electron donor is in the range of 5 to 35, preferably in the range of 5 to 25; the molar ratio of the co-catalyst to the titanium compound is in the range of 100 to 350, preferably in the range of 120 to 300.

[0069] A third aspect of this invention provides an application of the above-mentioned resin composition as a coating material for the surface of metal wires or pipes used in the shipbuilding, aerospace, construction, drilling, or machinery industries. As mentioned earlier, in these fields, especially for wires used in coated steel wire ropes, faster extrusion line speeds are required, which affects the surface quality, adhesion, and long-term stability of the resulting coating. Currently, firstly, existing propylene homopolymers exhibit lower melt flowability and lower crystallization rates at higher screw speeds; secondly, the greater the elastic phase component in current propylene copolymers, the greater the viscoelastic deformation of the melt, making it more prone to mold release expansion and resulting in irregular surface ripples. To address these problems, the resin composition material provided by this invention possesses excellent properties, such as suitable rheological properties, good stiffness-toughness balance, and high-speed processability. It can not only serve as a coating material, effectively protecting metal wires and pipes from damage by external environmental factors, but also significantly improve their service life and reliability.

[0070] Furthermore, the resin composition is extruded and coated onto the surface of the metal wire or metal tube at temperatures ranging from 190°C to 230°C to form a coating material. By applying the extrusion coating at the aforementioned appropriate temperatures, a strong bond can be achieved between the coating layer and the substrate, thereby significantly improving the stability and durability of the overall structure. Taking steel wire rope as an example, under these conditions, steel wire rope can be produced at processing speeds from 300 m / min to 1000 m / min in practical applications. The resulting steel wire rope not only possesses superior mechanical properties but also exhibits superior surface quality.

[0071] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0072] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0073] Before preparing the resin composition, the present invention provides a method for preparing the solid catalyst used as follows:

[0074] The reactor equipped with a stirrer was purged with nitrogen. 3000 mL of ethanol, 90 mL of 2-ethylhexanol, and 60 mL of isopropanol were added to the reactor, along with 3 g of magnesium chloride to dissolve them. After stirring, the temperature was increased, and then 45 g of magnesium powder was added sequentially. The reaction was continued until complete. The mixture was then washed, separated, and dried to obtain a dialkoxymagnesium support. A suspension was prepared by mixing the prepared support with 750 mL of toluene and 7.5 mL of di-n-butyl phthalate. In a nitrogen-purged reactor, 900 mL of toluene and 1200 mL of titanium tetrachloride were added, and the temperature was lowered to -5°C. The prepared suspension was then added to the reactor and kept at this temperature for 1.5 hours. The temperature was then slowly increased to 105°C, and at 80°C, 7.5 mL of di-n-butyl phthalate was added. The mixture was kept at this temperature for 1.5 hours, and then the liquid was filtered clean. Then, a mixture of 900 mL toluene and 1020 mL titanium tetrachloride was added, heated to 105 °C, stirred for 1 hour, the liquid was filtered off, the resulting solid was washed three times with hexane, the liquid was filtered off and dried to obtain the solid catalyst component.

[0075] Example 1

[0076] A method for preparing a resin composition:

[0077] (1) 10g of the solid catalyst component obtained above, 80g of triethylaluminum (as a co-catalyst), and 12g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.1 mol / kmol, and the ethylene / propylene ratio was controlled at 5.1 mol / kmol. Under the conditions of reaction temperature of 70℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0078] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.1:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 3 hours at a reaction temperature of 80°C and a reaction pressure of 2.0 MPa to obtain the polymerization product.

[0079] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:6.

[0080] (3) The polymerization product obtained from the second polymerization reactor was subjected to wet nitrogen gas to remove the activity of unreacted catalyst and then heated and dried to obtain polymer powder. This polymer powder was mixed with 0.1% of antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.1% of tris(2,4-di-tert-butylphenyl) phosphite, 0.01% of aluminum tert-butylbenzoate, and 0.02% of 1,3:2,4-dibenzyl sorbitol, and then melt-extruded and granulated to obtain a multiphase acrylic resin composition. The amounts of the antioxidants and nucleating agents added were all based on a 100% weight ratio of the total weight of the resin composition.

[0081] Example 2

[0082] A method for preparing a resin composition:

[0083] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 11g of methyl tert-butyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.0 mol / kmol, and the ethylene / propylene ratio was controlled at 5.0 mol / kmol. Under the conditions of reaction temperature of 70℃ and reaction pressure of 3.5 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0084] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.1:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.8 hours at a reaction temperature of 81°C and a reaction pressure of 1.5 MPa to obtain the polymerization product.

[0085] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:7.

[0086] (3) This step is consistent with Example 1.

[0087] Example 3

[0088] A method for preparing a resin composition:

[0089] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of diisobutyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.0 mol / kmol, and the ethylene / propylene ratio was controlled at 5.6 mol / kmol. Under the conditions of reaction temperature of 73℃ and reaction pressure of 5.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0090] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.14:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 3 hours at a reaction temperature of 85°C and a reaction pressure of 2.5 MPa to obtain the polymerization product.

[0091] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:10.

[0092] (3) This step is consistent with Example 1.

[0093] Example 4

[0094] A method for preparing a resin composition:

[0095] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 13g of diisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.2 mol / kmol, and the ethylene / propylene ratio was controlled at 4.8 mol / kmol. Under the conditions of reaction temperature of 75℃ and reaction pressure of 4.4 MPa, the reaction was carried out for 0.8 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0096] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.3:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 85°C and a reaction pressure of 2.2 MPa to obtain the polymerization product.

[0097] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:5.

[0098] (3) This step is consistent with Example 1.

[0099] Example 5

[0100] A method for preparing a resin composition:

[0101] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 13g of diisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.2 mol / kmol, and the ethylene / propylene ratio was controlled at 6.1 mol / kmol. Under the conditions of reaction temperature of 73℃ and reaction pressure of 5.1 MPa, the reaction was carried out for 1.8 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0102] (2) All the materials obtained after the reaction in the first reactor are fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.35:1 by weight) are introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction is carried out for 2.5 hours at a reaction temperature of 80°C and a reaction pressure of 2.5 MPa to obtain the polymerization product.

[0103] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:8.

[0104] (3) This step is consistent with Example 1.

[0105] Example 6

[0106] A method for preparing a resin composition:

[0107] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.4 mol / kmol, and the ethylene / propylene ratio was controlled at 4.7 mol / kmol. Under the conditions of reaction temperature of 77℃ and reaction pressure of 4.4 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0108] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.18:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.6 hours at a reaction temperature of 84°C and a reaction pressure of 2.6 MPa to obtain the polymerization product.

[0109] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:7.

[0110] (3) This step is consistent with Example 1.

[0111] Example 7

[0112] A method for preparing a resin composition:

[0113] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 13g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.7 mol / kmol, and the ethylene / propylene ratio was controlled at 5.1 mol / kmol. Under the conditions of reaction temperature of 84℃ and reaction pressure of 4.2 MPa, the reaction was carried out for 0.9 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0114] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.17:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 85°C and a reaction pressure of 3.0 MPa to obtain the polymerization product.

[0115] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:12.

[0116] (3) This step is consistent with Example 1.

[0117] Example 8

[0118] A method for preparing a resin composition:

[0119] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.8 mol / kmol, and the ethylene / propylene ratio was controlled at 4.9 mol / kmol. Under the conditions of reaction temperature of 77℃ and reaction pressure of 5.5MPa, the reaction was carried out for 0.9 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0120] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.38:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.5 hours at a reaction temperature of 80°C and a reaction pressure of 2.6 MPa to obtain the polymerization product.

[0121] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:9.

[0122] (3) This step is consistent with Example 1.

[0123] Example 9

[0124] A method for preparing a resin composition:

[0125] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 3.0 mol / kmol, and the ethylene / propylene ratio was controlled at 5.1 mol / kmol. Under the conditions of reaction temperature of 74℃ and reaction pressure of 4.5MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0126] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.0:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 83°C and a reaction pressure of 3.5 MPa to obtain the polymerization product.

[0127] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:6.

[0128] (3) This step is consistent with Example 1.

[0129] Example 10

[0130] A method for preparing a resin composition:

[0131] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and 1-butene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.4 mol / kmol, and the 1-butene / propylene ratio was controlled at 9.0 mol / kmol. Under the conditions of reaction temperature of 81℃ and reaction pressure of 4.4 MPa, the reaction was carried out for 0.7 hours to obtain a propylene-butene copolymer, i.e., the matrix phase.

[0132] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and 1-butene (propylene:1-butene = 1.55:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 85°C and a reaction pressure of 2.7 MPa to obtain the polymerization product.

[0133] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:12.

[0134] (3) This step is consistent with Example 1.

[0135] Example 11

[0136] A method for preparing a resin composition:

[0137] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and 1-butene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 3.4 mol / kmol, and the 1-butene / propylene ratio was controlled at 9.6 mol / kmol. Under the conditions of reaction temperature of 78℃ and reaction pressure of 5.0 MPa, the reaction was carried out for 0.7 hours to obtain a propylene-butene copolymer, i.e., the matrix phase.

[0138] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and 1-butene (propylene:1-butene = 1:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 82℃ and a reaction pressure of 2.6MPa to obtain the polymerization product.

[0139] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:8.

[0140] (3) This step is consistent with Example 1.

[0141] Example 12

[0142] A method for preparing a resin composition:

[0143] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 11g of dicyclopentyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and 1-butene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 3.4 mol / kmol, and the 1-butene / propylene ratio was controlled at 9.3 mol / kmol. Under the conditions of reaction temperature of 73℃ and reaction pressure of 5.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-butene copolymer, i.e., the matrix phase.

[0144] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and 1-butene (propylene:1-butene = 1.24:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.8 hours at a reaction temperature of 85°C and a reaction pressure of 1.8 MPa to obtain the polymerization product.

[0145] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:10.

[0146] (3) This step is consistent with Example 1.

[0147] Example 13

[0148] A method for preparing a resin composition:

[0149] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 11g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and 1-butene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 4.8 mol / kmol, and the 1-butene / propylene ratio was controlled at 9.0 mol / kmol. Under the conditions of reaction temperature of 74℃ and reaction pressure of 5.2 MPa, the reaction was carried out for 1 hour to obtain a propylene-butene copolymer, i.e., the matrix phase.

[0150] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and 1-butene (propylene:1-butene = 1.22:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.8 hours at a reaction temperature of 85°C and a reaction pressure of 2.0 MPa to obtain the polymerization product.

[0151] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:12.

[0152] (3) This step is consistent with Example 1.

[0153] Example 14

[0154] A method for preparing a resin composition:

[0155] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and 1-butene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 5.0 mol / kmol, and the 1-butene / propylene ratio was controlled at 9.4 mol / kmol. Under the conditions of reaction temperature of 75℃ and reaction pressure of 5.0 MPa, the reaction was carried out for 0.8 hours to obtain a propylene-butene copolymer, i.e., the matrix phase.

[0156] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and 1-butene (propylene:1-butene = 1.3:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.6 hours at a reaction temperature of 85°C and a reaction pressure of 2.5 MPa to obtain the polymerization product.

[0157] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:6.

[0158] (3) This step is consistent with Example 1.

[0159] Comparative Example 1

[0160] A method for preparing a resin composition:

[0161] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.6 mol / kmol, and the ethylene / propylene ratio was controlled at 3.1 mol / kmol. Under the conditions of reaction temperature of 71℃ and reaction pressure of 4.1 MPa, the reaction was carried out for 0.6 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0162] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.1:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 1.9 hours at a reaction temperature of 80°C and a reaction pressure of 1.7 MPa to obtain the polymerization product.

[0163] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:15.

[0164] (3) This step is consistent with Example 1.

[0165] Comparative Example 2

[0166] A method for preparing a resin composition:

[0167] (1) 10g of the solid catalyst component obtained above, 75g of triethylaluminum (as a co-catalyst), and 12g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 3.0 mol / kmol, and the ethylene / propylene ratio was controlled at 6.3 mol / kmol. Under the conditions of reaction temperature of 70℃ and reaction pressure of 4.1 MPa, the reaction was carried out for 0.8 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0168] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.5:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 79°C and a reaction pressure of 1.5 MPa to obtain the polymerization product.

[0169] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:20.

[0170] (3) This step is consistent with Example 1.

[0171] Comparative Example 3

[0172] A method for preparing a resin composition:

[0173] (1) 10g of the solid catalyst component obtained above, 85g of triisobutylaluminum (as a co-catalyst), and 12g of vinyltrimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.4 mol / kmol, and the ethylene / propylene ratio was controlled at 2.1 mol / kmol. Under the conditions of reaction temperature of 70℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 0.7 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0174] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 1.85:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 79°C and a reaction pressure of 1.5 MPa to obtain the polymerization product.

[0175] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:4.

[0176] (3) This step is consistent with Example 1.

[0177] Comparative Example 4

[0178] A method for preparing a resin composition:

[0179] (1) 10g of the solid catalyst component obtained above, 85g of triisobutylaluminum (as a co-catalyst), and 14g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 2.8 mol / kmol, and the ethylene / propylene ratio was controlled at 7.1 mol / kmol. Under the conditions of reaction temperature of 72℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0180] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.15:1, by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2 hours at a reaction temperature of 78°C and a reaction pressure of 1.5 MPa to obtain the polymerization product.

[0181] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:16.

[0182] (3) This step is consistent with Example 1.

[0183] Comparative Example 5

[0184] A method for preparing a resin composition:

[0185] (1) 10g of the solid catalyst component obtained above, 85g of triisobutylaluminum (as a co-catalyst), and 10g of trimethylmethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 1.8 mol / kmol, and the ethylene / propylene ratio was controlled at 2.4 mol / kmol. Under the conditions of reaction temperature of 70℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 0.8 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0186] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.05:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 3 hours at a reaction temperature of 80°C and a reaction pressure of 1.5 MPa to obtain the polymerization product.

[0187] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:3.

[0188] (3) This step is consistent with Example 1.

[0189] Comparative Example 6

[0190] A method for preparing a resin composition:

[0191] (1) 10g of the solid catalyst component obtained above, 85g of triisobutylaluminum (as a co-catalyst), and 10g of trimethylmethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 5.2 mol / kmol, and the ethylene / propylene ratio was controlled at 3.8 mol / kmol. Under the conditions of reaction temperature of 70℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0192] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.15:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 3 hours at a reaction temperature of 80°C and a reaction pressure of 1.5 MPa to obtain the polymerization product.

[0193] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:18.

[0194] (3) This step is consistent with Example 1.

[0195] Comparative Example 7

[0196] A method for preparing a resin composition:

[0197] (1) 10g of the solid catalyst component obtained above, 90g of triisobutylaluminum (as a co-catalyst), and 14g of trimethylmethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 7.0 mol / kmol, and the ethylene / propylene ratio was controlled at 3.9 mol / kmol. Under the conditions of reaction temperature of 74℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0198] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.5:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.5 hours at a reaction temperature of 78°C and a reaction pressure of 2.0 MPa to obtain the polymerization product.

[0199] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:8.

[0200] (3) This step is consistent with Example 1.

[0201] Comparative Example 8

[0202] A method for preparing a resin composition:

[0203] (1) 10g of the solid catalyst component obtained above, 90g of triisobutylaluminum (as a co-catalyst), and 12g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 8.0 mol / kmol, and the ethylene / propylene ratio was controlled at 2.8 mol / kmol. Under the conditions of reaction temperature of 72℃ and reaction pressure of 4.0 MPa, the reaction was carried out for 1 hour to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0204] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.5:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 3 hours at a reaction temperature of 80°C and a reaction pressure of 1.6 MPa to obtain the polymerization product.

[0205] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:5.

[0206] (3) This step is consistent with Example 1.

[0207] Comparative Example 9

[0208] A method for preparing a resin composition:

[0209] (1) 10 g of the solid catalyst component obtained above, 9.0 g of triisobutylaluminum (as a co-catalyst), and 11 g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 8.0 mol / kmol, and the ethylene / propylene ratio was controlled at 3.1 mol / kmol. Under the conditions of reaction temperature of 75℃ and reaction pressure of 4.2 MPa, the reaction was carried out for 0.8 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0210] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.2:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.6 hours at a reaction temperature of 82°C and a reaction pressure of 1.8 MPa to obtain the polymerization product.

[0211] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:22.

[0212] (3) This step is consistent with Example 1.

[0213] Comparative Example 10

[0214] A method for preparing a resin composition:

[0215] (1) 10g of the solid catalyst component obtained above, 90g of triisobutylaluminum (as a co-catalyst), and 11g of methylisopropyldimethoxysilane (as an external electron donor) were continuously introduced into the first reactor. Simultaneously, liquid propylene, hydrogen, and ethylene were continuously introduced into the first reactor, and the hydrogen / propylene ratio was controlled at 8.2 mol / kmol, and the ethylene / propylene ratio was controlled at 3.3 mol / kmol. Under the conditions of reaction temperature of 76℃ and reaction pressure of 4.3 MPa, the reaction was carried out for 0.9 hours to obtain a propylene-ethylene copolymer, i.e., the matrix phase.

[0216] (2) All the materials obtained after the reaction in the first reactor were fed into the second polymerization reactor, and propylene and ethylene (propylene:ethylene = 2.6:1 by weight) were introduced into the second polymerization reactor to continue the copolymerization reaction. The reaction was carried out for 2.5 hours at a reaction temperature of 83°C and a reaction pressure of 2.1 MPa to obtain the polymerization product.

[0217] In the above process, the weight ratio of propylene in step (1) to propylene in step (2) is 100:20.

[0218] (3) This step is consistent with Example 1.

[0219] Test methods

[0220] Crystallization-elution fractionation (CEF): The crystallization-elution fractionation curve was obtained using a Polymer Char (Spain) crystallization-elution fractionation (CEF) instrument. Approximately 10 mg of sample was dissolved in o-dichlorobenzene at 160 °C for 90 min, then cooled at 30 °C / min to 95 °C for stabilization. Crystallization was then carried out at 2 °C / min to 35 °C, while the column was slowly flushed by a liquid phase pump at a rate of 0.05 mL / min. After crystallization, elution was initiated at 4 °C / min and 1 mL / min to 150 °C. An IR-5 infrared detector recorded the sample information during the elution process, obtaining the crystallization-elution fractionation curve and the content of components in the resin composition with elution temperatures ≥100 °C. Furthermore, based on this instrument, the content of soluble components in the elastic phase of the resin composition can be simultaneously obtained during the testing process.

[0221] Thermal gradient interaction chromatography (TGIC): Tests were performed using a TGIC temperature gradient cross-chromatographic analyzer equipped with an IR-5 infrared detector by Polymer Char (Spain). The chromatographic column was replaced with a Hypercarb porous graphite column (100x).

[0222] The mobile phase was o-dichlorobenzene (4.6 mm, 5 μm). Key parameters included: cooling rate (CR), cooling flow rate (FC), heating rate (HR), elution rate (FE), injection volume, and cooling temperature (TC). Standard test conditions were: CR = 20℃ / min; FC = 0 mL / min; HR = 2℃ / min; FE = 0.5 mL / min; injection volume 200 μL; TC = 40℃. Differential gravimetric curves and integral cumulative gravimetric curves were obtained to determine the content of components with elution temperatures ≥100℃ and other parameters in the resin composition.

[0223] Characteristic viscosity: Measured by a viscometer in tetrahydronaphthalene at 135°C.

[0224] Molecular weight and distribution: High-temperature gel permeation chromatography (GPC) was used. The sample was dissolved in 1,2,4-trichlorobenzene at a concentration of 1.0 mg / mL. The test temperature was 150℃, and the solution flow rate was 1.0 mL / min. A standard curve was established using the molecular weight of polystyrene as an internal reference. The molecular weight, molecular weight distribution, and relative molecular mass integral distribution curve of the sample were calculated based on the elution time. The molecular weight distribution (MWD) is expressed as the Z-mean molecular weight (M). z ) and weight-average molecular weight (M w The ratio between ) is M z / M w .

[0225] Tensile properties: determined according to the method specified in GB / T 1040.2-2006.

[0226] Low-temperature impact strength: Measured at -20℃ according to GB / T 1043.1-2008.

[0227] Environmental stress cracking resistance (ESCR): Performed according to GB / T 1842-2008. Specimen dimensions were 38mm × 13mm × 2mm, with pre-made notches on the specimen surface. The notch direction was parallel to the specimen length and located at the center of the surface. The notch depth was 0.30–0.40mm, and 10 specimens were used. The notched specimens were bent and placed in test tubes containing surfactant. The test tubes were placed in a constant temperature water bath at 50℃. The time to cracking was observed, and the breakage rate was calculated.

[0228] Rheological properties: Determined at 220°C using a rotational rheometer via small amplitude oscillating shear (SAOS) testing. Test specimens can be compressed and molded at 200°C using a heated press. Test specimens can have a diameter of 25 mm and a thickness of approximately 1 mm. Before testing, the loaded specimens are equilibrated at the test temperature of 220°C for 5 minutes. The test angular frequency ranges from 0.01 to 628 rad / s, and the oscillating strain during testing is 3%.

[0229] Preparation and surface quality testing of the wire rope coating: Using a single-screw extruder and a standard wire rope extrusion die with the specified die size, the resin compositions obtained in the above examples and comparative examples were extruded onto the wire rope as coating layers. During extrusion, the extruder linear speed was 600 m / min; the wire rope was preheated to 100°C, and the melt temperature was set to 220°C. Subsequently, the final products were empirically evaluated from an optical perspective and ranked on a scale of 1 to 10, where "1" represents a very rough surface with point defects, and "10" represents a very smooth and uniform surface.

[0230] The test results are shown in Tables 1 and 2.

[0231] Table 1

[0232]

[0233]

[0234] Table 2

[0235]

[0236]

[0237] As can be seen from the above description, the embodiments of the present invention have achieved the preparation of resin compositions with superior physicochemical properties, especially rheological properties. The resulting resin compositions possess more suitable rheological properties and molecular weight distribution, while exhibiting superior mechanical properties, particularly good rigidity and toughness. When used as a coating material and prepared at a high rate to obtain coated steel wire ropes, the resulting steel wire rope material also exhibits good surface quality.

[0238] Specifically, regarding each embodiment, the data in the table shows that, compared to other embodiments, embodiments 3, 6, 9, and 12 to 14 possess superior overall performance. Therefore, by selectively setting the reaction temperature of the first polymerization reaction to 73°C–77°C and the reaction pressure to 4.4 MPa–5.2 MPa, and the reaction temperature of the second polymerization reaction to 83°C–85°C and the reaction pressure to 1.8 MPa–3.5 MPa, a better balance between rigidity and toughness can be achieved in the resulting resin composition, resulting in a steel wire rope coating material with higher overall performance and greater ability to withstand complex loads.

[0239] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0240] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A resin composition, characterized in that, The resin composition comprises a matrix phase and an elastic phase, and both the matrix phase and the elastic phase comprise propylene copolymers; The characteristic viscosity of the elastic phase is 1.0 dl / g to 2.5 dl / g; The elastic phase was subjected to crystallization elution and fractionation tests, and the content of soluble components in the elastic phase was 90wt% to 100wt%. The resin composition was subjected to a crystallization elution classification test, wherein the content of the component with an elution temperature ≥100℃ in the resin composition was 0.5wt% to 5wt%. The resin composition was subjected to thermal gradient interaction chromatography, and the content of the component with an elution temperature ≥100℃ in the resin composition was 1.5wt% to 10wt%. In the Cross rheological model, the non-Newtonian index n of the resin composition is 0.40 to 0.60, and the relaxation time λ is 3 s to 7 s.

2. The resin composition according to claim 1, characterized in that, The characteristic viscosity of the elastic phase is 1.5 dl / g to 2.0 dl / g; and / or, The elastic phase was subjected to crystallization elution fractionation test, and the content of soluble components in the elastic phase was 92wt% to 96wt%. And / or, The resin composition was subjected to a crystallization elution fractionation test, wherein the content of the component with an elution temperature ≥100°C in the resin composition was 0.5 wt% to 2 wt%; and / or, The resin composition was subjected to thermal gradient interaction chromatography, wherein the content of the component with an elution temperature ≥100°C in the resin composition was 2 wt% to 6 wt%; and / or, The resin composition has a non-Newtonian index n of 0.45 to 0.55 and a relaxation time λ of 5 to 7 seconds.

3. The resin composition according to claim 1 or 2, characterized in that, The Z-average molecular weight M of the resin composition z With weight-average molecular weight M w Satisfy: 4.5≤M z / M w ≤5.5, preferably 5.0≤M z / M w ≤5.4; and / or, On the molecular weight integral distribution curve, lg(M90) and lg(M50) of the resin composition satisfy: 1.10 ≤ lg(M90) / lg(M50) ≤ 1.15; and / or, On the relative molecular mass integral distribution curve, lg(M50) and lg(M10) of the resin composition satisfy: 1.20≤lg(M50) / lg(M10)≤1.

25.

4. The resin composition according to any one of claims 1 to 3, characterized in that, The resin composition further includes antioxidants and / or nucleating agents; Preferably, the antioxidant content is 0.01% to 1%, more preferably 0.1% to 0.5%, based on 100% of the total weight of the resin composition; and / or, the nucleating agent content is 0.001% to 5%, more preferably 0.01% to 3%, based on 100% of the total weight of the resin composition.

5. The resin composition according to any one of claims 1 to 4, characterized in that, The tensile strength of the resin composition is 25 MPa to 50 MPa, preferably 30 MPa to 40 MPa.

6. The resin composition according to any one of claims 1 to 5, characterized in that, The tensile fracture strain of the resin composition is 450% to 800%, preferably 600% to 700%.

7. The resin composition according to any one of claims 1 to 6, characterized in that, The resin composition has an impact strength of 40 kJ / m at -20°C. 2 ~70kJ / m 2 The preferred value is 50 kJ / m 2 ~60kJ / m 2 .

8. The resin composition according to any one of claims 1 to 7, characterized in that, The environmental stress cracking resistance time of the resin composition is 500h to 1000h, preferably 800h to 1000h.

9. A method for preparing a resin composition according to any one of claims 1 to 8, characterized in that, include: In step S1, propylene, hydrogen, and a first comonomer undergo a first polymerization reaction to obtain the matrix phase; the ratio of hydrogen to propylene is 2.0 mol / kmol to 5.0 mol / kmol, and the ratio of the first comonomer to propylene is 4.7 mol / kmol to 9.6 mol / kmol. In step S2, the matrix phase, propylene, and the second comonomer undergo a second polymerization reaction to form the elastic phase in the matrix phase, thereby obtaining the polymerization product; the weight ratio of propylene to the second comonomer is (1.0~2.5):

1. Step S3: Optionally, an antioxidant is added to the polymerization product, and the product is melt-extruded and granulated to obtain the resin composition; In step S1, the weight ratio of propylene to propylene in step S2 is 100:(5-12).

10. The method for preparing the resin composition according to claim 9, characterized in that, The first comonomer and the second comonomer are each independently selected from one or more α-olefins, and neither the first comonomer nor the second comonomer includes propylene; Preferably, the first comonomer and the second comonomer are each independently selected from one or more of ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene; More preferably, the first comonomer and the second comonomer are each independently ethylene and / or 1-butene.

11. The method for preparing the resin composition according to claim 9 or 10, characterized in that, Both the first comonomer and the second comonomer are ethylene, and: In step S1, the ratio of hydrogen to propylene is 2.0 mol / kmol to 3.0 mol / kmol, and the ratio of ethylene to propylene is 4.7 mol / kmol to 6.1 mol / kmol. In step S2, the weight ratio of propylene to ethylene is (2.0 to 2.38):

1.

12. The method for preparing the resin composition according to any one of claims 9 to 11, characterized in that, Both the first comonomer and the second comonomer are 1-butene, and: In step S1, the ratio of hydrogen to propylene is 2.4 mol / kmol to 5.0 mol / kmol, and the ratio of 1-butene to propylene is 9.0 mol / kmol to 9.6 mol / kmol. In step S2, the weight ratio of propylene to 1-butene is (1.0 to 1.55):

1.

13. The method for preparing the resin composition according to any one of claims 9 to 12, characterized in that, The reaction temperature of the first polymerization reaction is 65℃~85℃, the reaction pressure is 1.50MPa~8.0MPa, and the reaction time is 20min~80min; and / or, the reaction temperature of the second polymerization reaction is 75℃~95℃, the reaction pressure is 0.5~5.0MPa, and the reaction time is 70min~200min. Preferably, the reaction temperature of the first polymerization reaction is 68℃~80℃, the reaction pressure is 2.0MPa~6.0MPa, and the reaction time is 30min~60min; and / or, the reaction temperature of the second polymerization reaction is 78℃~90℃, the reaction pressure is 1.5MPa~3.5MPa, and the reaction time is 90min~180min.

14. The application of any one of the resin compositions of claims 1 to 8 as a coating material on the surface of metal wires or metal pipes used in the shipbuilding, aerospace, construction, drilling and extraction, or machinery industries.

15. The application according to claim 14, characterized in that, The resin composition is extruded and coated onto the surface of the metal wire or the metal tube at a temperature of 190°C to 230°C to form the coating material.

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