Graft-modified polypropylene material and method for preparing same

Abstract

The present invention relates to a graft-modified polypropylene material for use as an insulating material, which is related to the field of polymers, and to a method for preparing the same. The graft-modified polypropylene material contains structural units derived from a polypropylene copolymer and structural units derived from an alkenyl-containing polymerizable monomer. The content of the grafted structural units derived from the alkenyl-containing polymerizable monomer in the graft-modified polypropylene material is 0.1 to 14 wt %, and the polypropylene copolymer has at least one of the following characteristics: a comonomer content of 0.5 to 40 mol %, a xylene soluble content of 2 to 80 wt %, a comonomer content in the xylene soluble content of 10 to 70 wt %, and an intrinsic viscosity ratio of the xylene soluble content to the polypropylene copolymer of 0.3 to 5. The graft-modified polypropylene material of the present invention can achieve both excellent mechanical and electrical properties at higher service temperatures.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention belongs to the field of polymers, and in particular relates to a graft-modified polypropylene material, a method for preparing the graft-modified polypropylene material, the graft-modified polypropylene material obtained by the method, and the use of the graft-modified polypropylene material and cables.

[0002] [Background technology] Due to their excellent electrical insulating properties and low manufacturing costs, polymeric materials are widely used as insulating materials for electrical equipment in electrical engineering and the power industry. Among these, polymeric plastic insulating materials with simple structures, such as polyethylene, are particularly versatile. Cross-linked polyethylene, copolymer polyolefins, and rubber materials developed based on polyethylene are widely used in the insulation of motors and transformers, circuit insulation, and circuit breakers. Ethylene-based polymer insulating materials have better mechanical and thermal properties, excellent electrical insulating properties, and low prices, making them a relatively mature insulating material developed in engineering.

[0003] With the rapid development of the electric power industry, power grid systems are approaching higher voltage levels and greater electrical energy transmission capacity, placing greater demands on the performance of insulating materials. In response to this trend, conventional polyethylene-based insulating materials cannot meet the higher long-term service temperature and electric field requirements (the maximum long-term service temperature of currently available cross-linked polyethylene insulating materials is 70°C). Therefore, there is an urgent need to develop new insulating materials for electrical equipment that can meet the high service temperature and electric field strength requirements.

[0004] As a polymer plastic with a simple structure, polypropylene material possesses all the advantages of polyethylene. Compared to polyethylene, polypropylene has better electrical insulation properties and a higher melting point, making it suitable for use in harsher environments. However, polypropylene's mechanical properties are somewhat inferior to those of polyethylene, and it is particularly brittle at low temperatures, preventing its direct use as an insulating material. Therefore, to maintain its insulating properties under high temperatures and high electric fields, polypropylene must be modified to achieve comprehensive control of its electrical, mechanical, and thermal properties.

[0005] Many literatures and data have shown that doping nanoparticles into polypropylene materials for modification is an effective method for improving their electrical insulation performance. However, in actual manufacturing, the difficulty of controlling the doping behavior of nanoparticles leads to the aggregation of nanoparticles, which in turn reduces the insulating performance of the material, limiting its widespread application in practical engineering.

[0006] Therefore, it is necessary to explore new modified polypropylene materials that have clear insulating performance control ability, can take into account both mechanical and thermal properties, have stable performance, are easy to prepare, and are suitable for practical application in engineering.

[0007] [Contents of the invention] The present invention aims to overcome the above-mentioned drawbacks of the prior art and provides a novel graft-modified polypropylene material that can take into account both mechanical and electrical properties at higher use temperatures and is suitable for use conditions of high temperature and high operating field strength.

[0008] A first aspect of the present invention is a graft-modified polypropylene material for use as an insulating material, the graft-modified polypropylene material comprising structural units derived from a polypropylene copolymer and structural units derived from an alkenyl-containing polymerizable monomer, the content of the structural units derived from the alkenyl-containing polymerizable monomer and in a grafted state in the graft-modified polypropylene material being 0.1 to 14% by weight, preferably 0.2 to 7.5% by weight, based on the weight of the graft-modified polypropylene material, and the polypropylene copolymer having at least one of the following characteristics: a comonomer content of 0.5 to 40 mol%, preferably 0.5 to 14 mol%. The object of the present invention is to provide a graft-modified polypropylene material in which the intrinsic viscosity ratio of the xylene solubles is preferably 0.5 to 30 mol%, more preferably 4 to 25 wt%, and even more preferably 4 to 22 wt%; the content of xylene solubles is 2 to 80 wt%, preferably 18 to 75 wt%, more preferably 30 to 70 wt%, and even more preferably 30 to 67 wt%; the content of comonomers in the xylene solubles is 10 to 70 wt%, preferably 10 to 50 wt%, and more preferably 20 to 35 wt%; and the ratio of the intrinsic viscosity of the xylene solubles to the polypropylene copolymer is 0.3 to 5, preferably 0.5 to 3, and even more preferably 0.8 to 1.3.

[0009] A second aspect of the present invention is to provide a method for preparing a graft-modified polypropylene material for use as an insulating material, the method comprising the step of grafting a reaction mixture containing a polypropylene copolymer and an alkenyl-containing polymerizable monomer in the presence of an inert gas to obtain a graft-modified polypropylene material, wherein the graft-modified polypropylene material has a content of structural units derived from the alkenyl-containing polymerizable monomer and in a grafted state of 0.1 to 14% by weight, preferably 0.2 to 7.5% by weight, based on the weight of the graft-modified polypropylene material, and the polypropylene copolymer has a content of The copolymer has at least one of the following characteristics: the comonomer content is 0.5 to 40 mol%, preferably 0.5 to 30 mol%, more preferably 4 to 25 wt%, and even more preferably 4 to 22 wt%; the xylene soluble matter content is 2 to 80 wt%, preferably 18 to 75 wt%, more preferably 30 to 70 wt%, and even more preferably 30 to 67 wt%; the comonomer content in the xylene soluble matter is 10 to 70 wt%, preferably 10 to 50 wt%, and more preferably 20 to 35 wt%; and the intrinsic viscosity ratio of the xylene soluble matter to the polypropylene copolymer is 0.3 to 5, preferably 0.5 to 3, and even more preferably 0.8 to 1.3.

[0010] A third aspect of the present invention is to provide a graft-modified polypropylene material for insulating materials obtained by the above preparation method.

[0011] A fourth aspect of the present invention provides the use of the above graft-modified polypropylene material as an insulating material.

[0012] A fifth aspect of the present invention provides a cable comprising at least one conductor and at least one electrical insulating layer surrounding the conductor, characterized in that the material of the electrical insulating layer is the above-mentioned graft-modified polypropylene material.

[0013] A sixth aspect of the present invention is to provide an insulating material comprising the above-mentioned graft-modified polypropylene material.

[0014] [Brief description of the drawing] FIG. 1 is a schematic cross-sectional view of a cable according to one embodiment of the present invention.

[0015] (Explanation of symbols) 1 - conductor, 2 - conductor layer, 3 - electrical insulation layer, 4 - electrical insulation shielding layer, 5 - metallic shielding layer, 6 - inner sheath layer, 7 - outer sheath, 8 - outer sheath layer.

[0016] [Detailed Description of the Invention] A first aspect of the present invention provides a graft-modified polypropylene material for use as an insulating material, which comprises structural units derived from a polypropylene copolymer and structural units derived from an alkenyl-containing polymerizable monomer, and the content of the structural units derived from the alkenyl-containing polymerizable monomer and in a grafted state in the graft-modified polypropylene material is 0.1 to 14 wt %, preferably 0.2 to 7.5 wt %, relative to the weight of the graft-modified polypropylene material.

[0017] The polypropylene copolymer has at least one of the following characteristics: the comonomer content is 0.5 to 40 mol%, preferably 0.5 to 30 mol%, more preferably 4 to 25 wt%, and even more preferably 4 to 22 wt%; the xylene solubles content is 2 to 80 wt%, preferably 18 to 75 wt%, more preferably 30 to 70 wt%, and even more preferably 30 to 67 wt%; the comonomer content in the xylene solubles is 10 to 70 wt%, preferably 10 to 50 wt%, and more preferably 20 to 35 wt%; and the intrinsic viscosity ratio of the xylene solubles to the polypropylene copolymer is 0.3 to 5, preferably 0.5 to 3, and even more preferably 0.8 to 1.3.

[0018] In the present invention, the term "structural unit" refers to a part of a graft-modified polypropylene material, and its form is not limited. Specifically, the term "structural unit derived from a polypropylene copolymer" refers to a product formed from a polypropylene copolymer, including not only "radical" but also "polymer" forms. The term "structural unit derived from an alkenyl-containing polymerizable monomer" refers to a product formed from an alkenyl-containing polymerizable monomer, including not only "radical" but also "monomer" and "polymer" forms. The "structural unit" may be a repeating unit or a non-repeating independent unit.

[0019] A structural unit derived from an alkenyl-containing polymerizable monomer that is "grafted" refers to a structural unit derived from an alkenyl-containing polymerizable monomer that forms a covalent bond (graft) with the polypropylene copolymer.

[0020] In the present invention, the term "comonomer" of the polypropylene copolymer is known to those skilled in the art and means a monomer copolymerized with propylene.

[0021] According to the present invention, the graft-modified polypropylene material is preferably prepared by a graft reaction, preferably a solid-phase graft reaction, between a polypropylene copolymer and an alkenyl-containing polymerizable monomer. The graft reaction of the present invention is a radical polymerization reaction, and therefore, "in a grafted state" refers to a state in which a reactant forms a bond with another reactant after being subjected to radical polymerization. The bond includes both a direct bond and an indirect bond.

[0022] During the grafting reaction, the alkenyl-containing polymerizable monomers may polymerize with themselves or with each other to form a certain amount of non-grafted polymer. In the present invention, the term "graft-modified polypropylene material" includes not only the product (crude product) directly obtained by the grafting reaction of the polypropylene copolymer and the alkenyl-containing polymerizable monomers, but also the pure graft-modified polypropylene product obtained by further purifying the product.

[0023] According to the present invention, the polypropylene copolymer (the base polypropylene in the present invention) is a propylene copolymer containing ethylene glycol or a higher α-olefin or a mixture thereof. Specifically, the comonomer of the polypropylene copolymer is at least one selected from C2-C8 α-olefins other than propylene. The C2-C8 α-olefins other than propylene include at least one selected from ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene, preferably ethylene and / or 1-butene, but are not limited thereto. More preferably, the polypropylene copolymer consists of propylene and ethylene.

[0024] The polypropylene copolymer of the present invention may be a heterophasic propylene copolymer. The heterophasic propylene copolymer may contain a propylene homopolymer or a propylene random copolymer matrix component (1) and another propylene copolymer component (2) dispersed therein. In a propylene random copolymer, the comonomer is randomly distributed in the propylene polymer backbone. Preferably, the polypropylene copolymer of the present invention is a heterophasic propylene copolymer prepared in situ in a reactor by conventional processes.

[0025] According to a preferred embodiment, the heterophasic propylene copolymer comprises a propylene homopolymer matrix or a random copolymer matrix (1) and a propylene copolymer component (2) comprising one or more ethylene or higher α-olefin comonomers dispersed therein. The heterophasic propylene copolymer may have an islands-in-the-sea structure or a co-continuous structure.

[0026] Two heterophasic propylene copolymers are known in the art: those containing a random copolymer of propylene as the matrix phase, and those containing a homopolymer of propylene as the matrix phase. The random copolymer matrix (1) is a copolymer in which the comonomer moieties are randomly distributed on the polymer chain, in other words, it consists of two monomer units of random length (including single molecules) in alternating order. Preferably, the comonomer in matrix (1) is selected from ethylene or butene. It is particularly preferred that the comonomer in matrix (1) is ethylene.

[0027] Preferably, the propylene copolymer (2) dispersed in the heterophasic propylene copolymer homo- or copolymer matrix (1) is substantially amorphous. The term "substantially amorphous" means herein that the propylene copolymer (2) has a lower crystallinity than the homo- or copolymer matrix (1).

[0028] According to the present invention, in addition to the above compositional characteristics, the polypropylene copolymer has at least one of the following characteristics: a comonomer content of 0.5 to 40 mol%, preferably 0.5 to 30 mol%, more preferably 4 to 25 wt%, and even more preferably 4 to 22 wt%; a xylene soluble content of 2 to 80 wt%, preferably 18 to 75 wt%, more preferably 30 to 70 wt%, and even more preferably 30 to 67 wt%; a comonomer content in the xylene solubles of 10 to 70 wt%, preferably 10 to 50 wt%, and more preferably 20 to 35 wt%; and an intrinsic viscosity ratio of the xylene solubles to the polypropylene copolymer of 0.3 to 5, preferably 0.5 to 3, and even more preferably 0.8 to 1.3.

[0029] According to the present invention, the polypropylene copolymer preferably further has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 60 g / 10 min, preferably 0.05 to 35 g / 10 min, more preferably 0.5 to 15 g / 10 min; a melting point Tm of 100°C or higher, preferably 110 to 180°C, more preferably 110 to 170°C, even more preferably 120 to 170°C, and still more preferably 120 to 166°C; a weight average molecular weight of preferably 20 x 10 4 ~60×10 4 g / mol. A base polypropylene having a high Tm has sufficient impact strength and flexibility at both low and high temperatures, and in addition, when a base polypropylene having a high Tm is used, the graft-modified polypropylene of the present invention has the advantage of being able to withstand higher use temperatures. The polypropylene copolymer of the present invention is preferably in the form of a porous granular or powdered resin.

[0030] According to the present invention, the polypropylene copolymer preferably further has at least one of the following characteristics: a flexural modulus of 10 to 1000 MPa, preferably 50 to 600 MPa; an elongation at break of 200% or more, preferably 300%. Preferably, the tensile strength of the polypropylene copolymer is greater than 5 MPa, preferably 10 to 40 MPa.

[0031] The polypropylene copolymer of the present invention can include, but is not limited to, any commercially available polypropylene powder suitable for the present invention, such as NS06 from Sinopec Wuhan Petrochemical and SPF179 from Sinopec Qilu Petrochemical. It can also be produced by polymerization processes described in Chinese patents CN1081683, CN1108315, CN1228096, CN1281380, CN1132865C, and CN102020733A. Common polymerization processes include the Spheripol process from Basell, the Hypol process from Mitsui Oil Chemical, the Borstar PP process from Borealis, the Unipol process from DOW Chemical, and the Innovene gas-phase process from INEOS (formerly BP-Amoco).

[0032] According to the present invention, the graft-modified polypropylene material preferably has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, and more preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, preferably 20 to 1000 MPa, and more preferably 50 to 600 MPa; and an elongation at break of 200% or more, preferably 300% or more. Preferably, the graft-modified polypropylene material has a tensile strength of more than 5 MPa, preferably 10 to 40 MPa.

[0033] According to the present invention, preferably the graft modified polypropylene material has at least one of the following characteristics: The use temperature of the graft-modified polypropylene material is 90°C or higher, preferably 90-160°C; Breakdown field strength E of graft-modified polypropylene material at 90℃ g is 180 kV / mm or more, preferably 180 to 800 kV / mm; Breakdown field strength E of graft-modified polypropylene material at 90℃ g and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 0.7%, preferably 0.8 to 50%, more preferably 2 to 35%, and even more preferably 5 to 25%; DC volume resistivity ρ of graft-modified polypropylene materials at 90°C and 15 kV / mm electric field strength vg is 6 x 10 12 Ω.m or more, preferably 6×10 12 Ω.m~1.0×10 20 is Ω.m; DC volume resistivity ρ of polypropylene copolymer at 90°C and 15kV / mm field strength v DC volume resistivity ρ of graft-modified polypropylene material at 90°C and 15kV / mm electric field strength vg The ratio (ρ vg / ρ v ) exceeds 1, and is preferably 1.1 to 50, more preferably 1.15 to 20, and even more preferably 1.2 to 10.

[0034] Preferably, the graft-modified polypropylene material has a dielectric constant at 90° C. and 50 Hz of more than 2.0, preferably 2.1 to 2.5.

[0035] According to the present invention, the alkenyl-containing polymerizable monomer is at least one selected from monomers having a structure represented by Formula 1.

[0036] [ka]

[0037] In formula 1, R b , R c , R d are each independently selected from H, substituted or unsubstituted alkyl; R ais selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted ester group, substituted or unsubstituted carboxyl, substituted or unsubstituted cycloalkyl or heterocyclyl, cyano, substituted or unsubstituted silyl.

[0038] According to the present invention, preferably R b , R c , R d are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R a Substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C6-C 20 Aryl, substituted or unsubstituted C1-C 20 Ester groups, substituted or unsubstituted C1-C 20 Carboxyl, substituted or unsubstituted C3-C 20 Cycloalkyl or heterocyclyl, cyano, substituted or unsubstituted C3-C 20 silyl, the substituents of which are halogen, hydroxy, amino, C1-C 12 Alkyl, C3-C6 cycloalkyl, C1-C 12 Alkoxy, C1-C 12 It is acyloxy.

[0039] According to the present invention, preferably R b , R c , R d are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R a is selected from a group represented by formula 2, a group represented by formula 3, a group represented by formula 4, a group represented by formula 5, a group represented by formula 6, a combination of a group represented by formula 6 and a group represented by formula 7, and a heterocyclic group:

[0040] [ka]

[0041] In formula 2, R 4-R 8 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, preferably R 4 -R 8 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy;

[0042] [ka]

[0043] In formula 3, R4-R 10 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, preferably R-R10 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, and C1-C6 alkoxy;

[0044] [ka]

[0045] In formula 4, R4'-R 10 ' are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C1-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, preferably R4'-R 10 each ' is independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, and C1-C6 alkoxy;

[0046] [ka]

[0047] In Formula 5, R', R'', and R''' each independently represent Substituted or unsubstituted C1-C 12 Straight chain alkyl, Substituted or unsubstituted C3-C12 Branched alkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 acyloxy, preferably R1 is C2-C6 alkenyl, preferably monounsaturated alkenyl, and R2, R3, R4 are each independently selected from: Substituted or unsubstituted C1-C6 straight chain alkyl, Substituted or unsubstituted selected from C3-C6 branched alkyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C1-C6 acyloxy;

[0048] [ka]

[0049] [ka]

[0050] In formula 6, R m is substituted or unsubstituted, C1-C 20 Straight chain alkyl, C3-C 20 Branched alkyl, C3-C 12 Cycloalkyl, C3-C 12 Epoxy alkyl, C3-C 12 epoxyalkylalkyl, the substituents of which are at least one selected from halogen, amino, and hydroxy; The heterocyclic group is selected from imidazolyl, pyrazolyl, carbazolyl, pyrrolidinonyl, pyridyl, piperidinyl, caprolactam group, pyrazinyl, thiazolyl, purinyl, morpholinyl, oxazolinyl.

[0051] According to a preferred embodiment of the present invention, the graft-modified polypropylene material is an aromatic olefin-graft-modified polypropylene material, the alkenyl-containing polymerizable monomer is a styrene monomer, and the content of structural units derived from the styrene monomer and in a grafted state in the aromatic olefin-graft-modified polypropylene material is 0.5 to 14 wt %, preferably 1 to 7.5 wt %, more preferably 1.5 to 5 wt %, based on the weight of the aromatic olefin-graft-modified polypropylene material; Preferably, the styrene monomer is at least one selected from a monomer having a structure represented by formula 8, a monomer having a structure represented by formula 9, and a monomer having a structure represented by formula 10;

[0052] [ka]

[0053] In formula 8, R 1 , R 2 , R 3 are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R 4 -R 8 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, preferably R 1 , R 2 , R 3are each independently selected from H, substituted or unsubstituted C1-C3 alkyl, and R 4 -R 8 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy;

[0054] [ka]

[0055] In Formula 9, R1, R2, and R3 are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R4-R 10 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups; preferably, R1, R2, and R3 are each independently selected from H, substituted or unsubstituted C1-C3 alkyl, and R4-R 10 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, C1-C6 alkoxy;

[0056] [ka]

[0057] In Formula 10, R1', R2', and R3' are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R4'-R 10 ' are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C1-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups; preferably, R1', R2', and R3' are each independently selected from H, substituted or unsubstituted C1-C3 alkyl, and R4'-R 10 each ' is independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, C1-C6 alkoxy; Preferably, the styrene monomer is at least one selected from styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, mono- or poly-substituted styrene, mono- or poly-substituted α-methylstyrene, mono- or poly-substituted 1-vinylnaphthalene, and mono- or poly-substituted 2-vinylnaphthalene; the substituents thereof are preferably at least one selected from halogen, hydroxy, amino, phosphate group, sulfonate group, C1-C8 straight chain alkyl, C3-C8 branched alkyl or cycloalkyl, C1-C6 straight chain alkoxy, C3-C8 branched alkoxy or cycloalkoxy, C1-C8 straight chain ester group, C3-C8 branched ester group or cyclic ester group, C1-C8 straight chain amine group, and C3-C8 branched amine group or cyclic amine group.

[0058] More preferably, the styrene monomer is at least one selected from styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene and 4-methylstyrene.

[0059] According to the present invention, the aromatic olefin graft-modified polypropylene material preferably has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, and more preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, preferably 20 to 1000 MPa, and more preferably 50 to 600 MPa; and an elongation at break of 200% or more, preferably 300% or more. Preferably, the tensile strength of the aromatic olefin graft-modified polypropylene material is greater than 5 MPa, preferably 10 to 40 MPa.

[0060] According to the present invention, preferably, the aromatic olefin graft modified polypropylene material has at least one of the following characteristics: The use temperature of the aromatic olefin graft-modified polypropylene material is 90°C or higher, preferably 90 to 160°C; Breakdown field strength E of aromatic olefin grafted polypropylene material at 90℃ g is 200 kV / mm or more, preferably 200 to 800 kV / mm; Breakdown field strength E of aromatic olefin grafted polypropylene material at 90℃ g and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 1.5%, preferably 1.6 to 40%, more preferably 5 to 30%, and even more preferably 10 to 20%; DC volume resistivity ρ of aromatic olefin grafted polypropylene material at 90℃ and 15kV / mm electric field strength vg is 1.0×10 13 Ω.m or more, preferably 1.5×10 13 Ω.m~1.0×10 20 is Ω.m; DC volume resistivity ρ of aromatic olefin grafted polypropylene material at 90℃ and 15kV / mm electric field strength v DC volume resistivity ρ of graft-modified polypropylene material at 90°C and 15kV / mm electric field strength vg The ratio (ρ vg / ρ v ) exceeds 1, and is preferably 1.5 to 50, more preferably 2 to 20, and even more preferably 3 to 10.

[0061] According to a specific embodiment of the present invention, the graft-modified polypropylene material is a silane-modified polypropylene graft, the alkenyl-containing polymerizable monomer is an alkenyl-containing silane monomer, and the content of the structural unit in the silane-modified polypropylene graft, which is derived from the alkenyl-containing silane monomer and is in a grafted state, is 0.2-6 wt%, preferably 0.2-2.5 wt%, based on the weight of the silane-modified polypropylene graft; Preferably, the alkenyl-containing silane monomer is at least one selected from monomers having a structure represented by formula 11:

[0062] [ka]

[0063] In formula 11, R1 is C2-C 12 alkenyl, preferably monounsaturated alkenyl; R2, R3, and R4 are each independently substituted or unsubstituted C1-C 12 Straight chain alkyl, substituted or unsubstituted C3-C 12 Branched alkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Preferably, R1 is a C2-C6 alkenyl, preferably a monounsaturated alkenyl; R2, R3, and R4 are each independently selected from substituted or unsubstituted C1-C6 linear alkyl, substituted or unsubstituted C3-C6 branched alkyl, substituted or unsubstituted C1-C6 alkoxy, and substituted or unsubstituted C1-C6 acyloxy; More preferably, the alkenyl-containing silane monomer is at least one selected from vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane, vinyltri-tert-butoxysilane, vinyltriacetoxysilane, methylvinyldimethoxysilane, ethylvinyldiethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, allyltriisopropoxysilane, vinyltris(β-methoxyethoxy)silane, allyltris(β-methoxyethoxy)silane, allyltri-tert-butoxysilane, allyltriacetoxysilane, methylallyldimethoxysilane, and ethylallyldiethoxysilane.

[0064] According to the present invention, the silane-modified polypropylene graft preferably has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, and more preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1000 MPa, more preferably 50 to 600 MPa; and an elongation at break of 200% or more, preferably 300% or more. Preferably, the tensile strength of the silane-modified polypropylene graft is greater than 5 MPa, preferably 10 to 40 MPa.

[0065] According to the present invention, preferably, the silane-modified polypropylene graft has at least one of the following characteristics: The use temperature of the silane-modified polypropylene graft is 90°C or higher, preferably 90-160°C; Breakdown field strength E of silane-modified polypropylene graft at 90℃ g is 200 kV / mm or more, preferably 200 to 800 kV / mm; Breakdown field strength E of silane-modified polypropylene graft at 90℃ g and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 0.7%, preferably 0.8 to 40%, more preferably 2 to 20%, and even more preferably 6 to 15%; DC volume resistivity ρ of silane-modified polypropylene grafts at 90°C and 15 kV / mm field strength vg is 6 x 10 12 Ω.m or more, preferably 6×10 12 Ω.m~1.0×10 20 is Ω.m; DC volume resistivity ρ of polypropylene copolymer at 90°C and 15kV / mm field strength v DC volume resistivity ρ of silane-modified polypropylene grafted at 90°C and 15 kV / mm electric field strength against vg The ratio (ρ vg / ρ v) exceeds 1, and is preferably 1.1 to 8.0, more preferably 1.15 to 3, and even more preferably 1.2 to 1.8.

[0066] According to a specific embodiment of the present invention, the alkenyl-containing polymerizable monomer is an acrylate monomer and an optional acrylic monomer, and the content of the structural units in the graft-modified polypropylene material, which are derived from the acrylate monomer and the optional acrylic monomer and are in a grafted state, is 0.3 to 7 wt %, preferably 0.8 to 5 wt %, based on the weight of the graft-modified polypropylene material; Preferably, the acrylate monomer is at least one selected from monomers having a structure represented by formula 12:

[0067] [ka]

[0068] In Formula 12, R1, R2, and R3 are each independently selected from H, C1-C6 linear alkyl, and C3-C6 branched alkyl; R4 is a substituted or unsubstituted C1-C 20 Straight chain alkyl, C3-C 20 Branched alkyl, C3-C 12 Cycloalkyl, C3-C 12 Epoxy alkyl, C3-C 12 epoxyalkylalkyl, the substituents of which are at least one selected from halogen, amino, and hydroxy; More preferably, the acrylate monomer is at least one selected from methyl(methyl)acrylate, sec-butyl(methyl)acrylate, ethyl(methyl)acrylate, n-butyl(methyl)acrylate, isobutyl(methyl)acrylate, tert-butyl(methyl)acrylate, isooctyl(methyl)acrylate, dodecyl(methyl)acrylate, cocinin(methyl)acrylate, octadecyl(methyl)acrylate, dimethylaminoethyl(methyl)acrylate, diethylaminoethyl(methyl)acrylate, dimethylaminopropyl(methyl)acrylate, and glycidyl(methyl)acrylate; Preferably, the acrylic monomer is at least one selected from monomers having a structure represented by formula 13:

[0069] [ka]

[0070] In formula 13, R 1 , R 2 , R 3 are each independently selected from H, C1-C6 straight chain alkyl, and C3-C6 branched alkyl; More preferably, the acrylic monomer is at least one selected from acrylic acid, methacrylic acid, and 2-ethylacrylic acid.

[0071] As used herein, C3-C 12 Epoxyalkylalkyl refers to an epoxyalkyl-substituted alkyl having 3 to 12 carbon atoms, such as oxiranylmethyl.

[0072] According to the present invention, the molar ratio of structural units derived from acrylate monomers to structural units derived from acrylic monomers is preferably 1:0-2, more preferably 1:0.125-1.

[0073] According to the present invention, preferably, the alkenyl-containing polymerizable monomer is an acrylate monomer and an optional acrylic monomer, and the graft-modified polypropylene material has at least one of the following characteristics: a melt flow rate at 230°C under a load of 2.16 kg of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, more preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1100 MPa, preferably 20 to 1000 MPa, more preferably 50 to 600 MPa; and an elongation at break of 200% or more, preferably 300% or more. Preferably, the graft-modified polypropylene material has a tensile strength of more than 5 MPa, preferably 10-40 MPa.

[0074] According to the present invention, preferably the alkenyl-containing polymerizable monomers are acrylate monomers and optionally acrylic monomers, and the graft-modified polypropylene material has at least one of the following characteristics: The use temperature of the graft-modified polypropylene material is 90°C or higher, preferably 90-160°C; Breakdown field strength E of graft-modified polypropylene material at 90℃ g is 180 kV / mm or more, preferably 180 to 800 kV / mm; Breakdown field strength E of graft-modified polypropylene material at 90℃ g and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 2%, preferably 2.5 to 50%, more preferably 4 to 35%, and even more preferably 5 to 25%; DC volume resistivity ρ of graft-modified polypropylene materials at 90°C and 15 kV / mm electric field strength vg is 1.0×10 13 Ω.m or more, preferably 1.5×10 13 Ω.m~1.0×10 20 is Ω.m; DC volume resistivity ρ of polypropylene copolymer at 90°C and 15kV / mm field strength v DC volume resistivity ρ of graft-modified polypropylene material at 90°C and 15kV / mm electric field strength vg The ratio (ρ vg / ρ v ) exceeds 1.5, is preferably 1.8 to 30, more preferably 2 to 10, and further preferably 2.5 to 6.

[0075] According to a specific embodiment of the present invention, the graft-modified polypropylene material is a heterocyclic graft-modified polypropylene material, the alkenyl-containing polymerizable monomer is an alkenyl-containing heterocyclic monomer, and the content of the structural unit derived from the alkenyl-containing heterocyclic monomer and in a grafted state in the heterocyclic graft-modified polypropylene material is 0.5 to 6 wt%, preferably 0.5 to 4 wt%, based on the weight of the heterocyclic graft-modified polypropylene material; Preferably, the alkenyl-containing heterocyclic monomer is at least one selected from alkenyl-containing imidazole, alkenyl-containing pyrazole, alkenyl-containing carbazole, alkenyl-containing pyrrolidone, alkenyl-containing pyridine or pyridinium, alkenyl-containing piperidine, alkenyl-containing caprolactam, alkenyl-containing pyrazine, alkenyl-containing thiazole, alkenyl-containing purine, alkenyl-containing morpholine, and alkenyl-containing oxazoline; preferably, the alkenyl-containing heterocyclic monomer is a monoalkenyl-containing heterocyclic monomer.

[0076] Preferably, the alkenyl-containing heterocyclic monomer is at least one selected from 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-allylimidazole, 1-vinylpyrazole, 3-methyl-1-vinylpyrazole, vinylcarbazole, N-vinylpyrrolidone, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, vinylpyridine N-oxide, vinylpyridinium, vinylpiperidine, N-vinylcaprolactam, 2-vinylpyrazine, N-vinylpiperazine, 4-methyl-5-vinylthiazole, N-vinylpurine, vinylmorpholine, and vinyloxazoline.

[0077] According to the present invention, the heterocyclic graft-modified polypropylene material preferably has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, and even more preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, preferably 50 to 500 MPa; and an elongation at break of 200% or more, preferably 300% or more. Preferably, the tensile strength of the heterocyclic graft-modified polypropylene material is greater than 5 MPa, preferably 10 to 40 MPa.

[0078] According to the present invention, preferably, the heterocyclic graft modified polypropylene material has at least one of the following characteristics: The use temperature of the heterocyclic graft modified polypropylene material is 90°C or higher, preferably 90-160°C; Breakdown field strength E of heterocyclic graft-modified polypropylene material at 90℃ g is 190 kV / mm or more, preferably 190 to 800 kV / mm; Breakdown field strength E of heterocyclic graft-modified polypropylene material at 90℃ gand the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 1%, preferably 1.5 to 50%, more preferably 2 to 35%, and even more preferably 5 to 25%; DC volume resistivity ρ of heterocyclic graft modified polypropylene materials at 90°C and 15kV / mm electric field strength vg is 7 x 10 12 Ω.m or more, preferably 7×10 12 Ω.m~1.0×10 20 is Ω.m; DC volume resistivity ρ of heterocyclic graft modified polypropylene materials at 90°C and 15kV / mm electric field strength v DC volume resistivity ρ of graft-modified polypropylene material at 90°C and 15kV / mm electric field strength vg The ratio (ρ vg / ρ v ) exceeds 1, and is preferably 1.1 to 20, more preferably 1.2 to 10, and even more preferably 1.3 to 4.

[0079] The polypropylene graft of the present invention can be prepared by a process comprising the steps of subjecting a reaction mixture containing a polypropylene copolymer and an alkenyl-containing polymerizable monomer to a solid-phase graft reaction in the presence of an inert gas to obtain a polypropylene graft.

[0080] A second aspect of the present invention provides a method for preparing a graft-modified polypropylene material for use in insulating materials, the method comprising the step of grafting a reaction mixture containing a polypropylene copolymer and an alkenyl-containing polymerizable monomer in the presence of an inert gas to obtain the graft-modified polypropylene material, wherein the grafting reaction conditions are as follows: the content of the structural units in the graft-modified polypropylene material, which are derived from the alkenyl-containing polymerizable monomer and are in a grafted state, is 0.1 to 14 wt %, preferably 0.2 to 7.5 wt %, based on the weight of the graft-modified polypropylene material; The polypropylene copolymer has at least one of the following characteristics: the comonomer content is 0.5 to 40 mol%, preferably 0.5 to 30 mol%, more preferably 4 to 25 wt%, and even more preferably 4 to 22 wt%; the xylene solubles content is 2 to 80 wt%, preferably 18 to 75 wt%, more preferably 30 to 70 wt%, and even more preferably 30 to 67 wt%; the comonomer content in the xylene solubles is 10 to 70 wt%, preferably 10 to 50 wt%, and more preferably 20 to 35 wt%; and the intrinsic viscosity ratio of the xylene solubles to the polypropylene copolymer is 0.3 to 5, preferably 0.5 to 3, and even more preferably 0.8 to 1.3.

[0081] The grafting reaction of the present invention can be carried out by various methods conventionally used in the art, preferably by solid-phase grafting reaction, such as forming active grafting sites on a polypropylene copolymer in the presence of an alkenyl-containing polymerizable monomer for grafting, or by first forming active grafting sites on a polypropylene copolymer and then treating it with a monomer for grafting. The grafting sites can be formed by treatment with a free radical initiator or by treatment with high-energy ionizing radiation or microwaves. Free radicals generated in the polymer as a result of chemical or radiation treatment form grafting sites on the polymer and initiate polymerization of the monomer at these sites.

[0082] Preferably, the grafting sites are initiated and the grafting reaction is furthered by a free radical initiator, in which case the reaction mixture comprises a free radical initiator, more preferably the free radical initiator is selected from a peroxide-based free radical initiator and / or an azo-based free radical initiator.

[0083] The peroxide-based free radical initiator is preferably at least one selected from dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, dodecyl peroxide, tert-butylperoxybenzoic acid, diisopropyl peroxydicarbonate, tert-butylperoxy(2-ethylhexanoate), and dicyclohexyl peroxydicarbonate; and the azo-based free radical initiator is preferably azobisisobutyronitrile and / or azobisisoheptonitrile.

[0084] More preferably, the grafting sites are initiated with a peroxide-based free radical initiator to further the grafting reaction.

[0085] Furthermore, the grafting reaction of the present invention can also be carried out according to the methods described in CN106543369A, CN104499281A, CN102108112A, CN109251270A, CN1884326A and CN101492517B.

[0086] Furthermore, the present invention does not particularly limit the technical conditions of the grafting reaction. Specifically, the grafting reaction temperature may be 30 to 130°C, preferably 60 to 120°C; and the reaction time may be 0.5 to 10 hours, preferably 1 to 5 hours.

[0087] The amount of each component used in the grafting reaction of the present invention is not particularly limited, provided that the above-mentioned characteristics of the product are satisfied.

[0088] In the case of styrene monomer, the mass ratio of the free radical initiator to the styrene monomer is 0.1 to 10:100, preferably 0.5 to 5:100. The mass ratio of the styrene monomer to the polypropylene copolymer is 0.5 to 16:100, preferably 1 to 12:100, more preferably 2 to 10:100. As for the conditions of the grafting reaction, the content of structural units derived from the styrene monomer and in a grafted state in the aromatic olefin graft-modified polypropylene material is 0.5 to 14 wt%, preferably 1 to 7.5 wt%, more preferably 1.5 to 5 wt%, based on the weight of the aromatic olefin graft-modified polypropylene material.

[0089] In the case of an alkenyl-containing silane monomer, the mass ratio of the free radical initiator to the alkenyl-containing silane monomer is 0.1 to 10:100, preferably 0.5 to 6:100. The mass ratio of the alkenyl-containing silane monomer to the polypropylene copolymer is 0.5 to 12:100, preferably 0.8 to 9:100, more preferably 1 to 6:100. As for the grafting reaction conditions, the content of structural units derived from the alkenyl-containing silane monomer and in a grafted state in the silane-modified polypropylene graft is 0.2 to 6 wt%, preferably 0.2 to 2.5 wt%, based on the weight of the silane-modified polypropylene graft.

[0090] In the case of an acrylate monomer and an optional acrylic monomer, the mass ratio of the free radical initiator to the total mass of the acrylate monomer and the optional acrylic monomer is 0.1 to 10:100, preferably 0.5 to 5:100. The mass ratio of the total mass of the acrylate monomer and the optional acrylic monomer to the mass of the polypropylene copolymer is 0.1 to 10:100, preferably 0.5 to 8:100, more preferably 0.8 to 7:100. As for the grafting reaction conditions, the content of structural units derived from the acrylate monomer and the optional acrylic monomer and in a grafted state in the graft-modified polypropylene material is 0.3 to 7 wt %, preferably 0.8 to 5 wt %, based on the weight of the graft-modified polypropylene material.

[0091] In the case of an alkenyl-containing heterocyclic monomer, the mass ratio of the free radical initiator to the alkenyl-containing heterocyclic monomer is 0.1 to 10:100, preferably 0.5 to 5:100. The mass ratio of the alkenyl-containing heterocyclic monomer to the polypropylene copolymer is 0.3 to 12:100, preferably 0.5 to 10:100. As for the grafting reaction conditions, the content of structural units derived from the alkenyl-containing heterocyclic monomer and in a grafted state in the heterocyclic-graft-modified polypropylene material is 0.5 to 6 wt%, preferably 0.5 to 4 wt%, based on the weight of the heterocyclic-graft-modified polypropylene material.

[0092] In the present invention, the term "reaction mixture" includes all materials added to the grafting reaction system, which may be added all at once or at different stages of the reaction.

[0093] The reaction mixture of the present invention may also contain a dispersant, which is preferably water or an aqueous solution of sodium chloride. The mass content of the dispersant is preferably 50 to 300% of the mass of the polypropylene copolymer.

[0094] The reaction mixture of the present invention may further contain an interfacial agent. The interfacial agent is an organic solvent that has a swelling effect on polyolefins, preferably at least one selected from the following organic solvents that have a swelling effect on polypropylene copolymers: ether solvents, ketone solvents, aromatic hydrocarbon solvents, and alkane solvents; more preferably at least one selected from the following organic solvents: chlorobenzene, polychlorinated benzenes, alkanes or C6 or higher cycloalkanes, benzene, C1-C4 alkyl-substituted benzenes, C2-C6 fatty ethers, C3-C6 fatty ketones, and decalin; even more preferably at least one selected from the following organic solvents: benzene, toluene, xylene, chlorobenzene, tetrahydrofuran, diethyl ether, acetone, hexane, cyclohexane, decalin, and heptane. The mass content of the interfacial agent is preferably 1 to 30% of the mass of the polypropylene copolymer, more preferably 10 to 25%.

[0095] The reaction mixture of the present invention may further contain an organic solvent to dissolve the solid free radical initiator. The organic solvent preferably contains at least one selected from C2-C5 alcohols, C2-C4 ethers, and C3-C5 ketones, more preferably at least one selected from C2-C4 alcohols, C2-C3 ethers, and C3-C5 ketones, and most preferably at least one selected from ethanol, diethyl ether, and acetone. The mass content of the organic solvent is preferably 1 to 35% of the mass of the polypropylene copolymer.

[0096] In the method for preparing the graft-modified polypropylene material of the present invention, the definitions of the alkenyl-containing polymerizable monomer and the polypropylene copolymer are the same as those set forth above, and will not be repeated here.

[0097] According to the present invention, the method for producing the graft-modified polypropylene material can be selected from the following: Method I, the preparation method includes the steps of: (a) placing a polypropylene copolymer in a sealed reactor and then replacing the reactor with an inert gas; (b) adding a free radical initiator and an alkenyl-containing polymerizable monomer to a closed reactor and mixing with stirring; (c) optionally adding an interfacial agent and optionally swelling the reaction system; (d) optionally adding a dispersant and heating the reaction system to a grafting reaction temperature to carry out the grafting reaction; (e) After completion of the reaction, optionally filtering (if an aqueous phase dispersant is used) and drying to obtain the graft-modified polypropylene material.

[0098] More specifically, the preparation method includes the following steps: (a) placing a polypropylene copolymer in a sealed reactor and then replacing the reactor with an inert gas; (b) dissolving a free radical initiator in an alkenyl-containing polymerizable monomer to obtain a solution, and adding the solution to a closed reactor containing the polypropylene copolymer and mixing with stirring; (c) adding 0 to 30 parts of an interfacial agent and optionally swelling the reaction system at 20 to 60°C for 0 to 24 hours; (d) adding 0 to 300 parts of a dispersant, heating the reaction system to a graft polymerization temperature of 30 to 130°C, and reacting for 0.5 to 10 hours; (e) After completion of the reaction, optionally filtering (if an aqueous phase dispersant is used) and drying to obtain the graft-modified polypropylene material.

[0099] Method II, the preparation method includes the steps of: (a) placing a polypropylene copolymer in a sealed reactor and then replacing the reactor with an inert gas; (b) mixing an organic solvent and a free radical initiator and adding the mixture to a closed reactor; (c) removing the organic solvent; (d) adding an alkenyl-containing polymerizable monomer, optionally adding an interfacial agent, and optionally swelling the reaction system; (e) optionally adding a dispersant and heating the reaction system to a grafting reaction temperature to carry out the grafting reaction; (f) After completion of the reaction, optionally filtering (if an aqueous phase dispersant is used) and drying to obtain the graft-modified polypropylene material.

[0100] More specifically, the preparation method includes the following steps: (a) placing a polypropylene copolymer in a sealed reactor and then replacing the reactor with an inert gas; (b) mixing an organic solvent and a free radical initiator to obtain a solution and adding the solution to a closed reactor containing the polypropylene copolymer; (c) removing the organic solvent by inert gas purging or reduced pressure; (d) adding an alkenyl-containing polymerizable monomer and 0 to 30 parts of an interfacial agent, and optionally swelling the reaction system at 20 to 60°C for 0 to 24 hours; (e) adding 0 to 300 parts of a dispersant, heating the system to a graft polymerization temperature of 30 to 130°C, and reacting for 0.5 to 10 hours; (f) After completion of the reaction, optionally filtering (if an aqueous phase dispersant is used) and drying to obtain the graft-modified polypropylene material.

[0101] According to the method of the present invention, if volatile components are present in the system after the reaction is completed, the method of the present invention preferably includes a step of devolatilizing. This step can be carried out by any conventional method, including vacuum extraction or using a stripping agent at the end of the grafting reaction. Suitable stripping agents include, but are not limited to, inert gases.

[0102] As described above, the term "graft-modified polypropylene material" in the present invention includes not only the product (crude product) directly obtained by the graft reaction of a polypropylene copolymer and an alkenyl-containing polymerizable monomer, but also the pure graft-modified polypropylene product obtained by further purifying the product. Therefore, the preparation method of the present invention optionally includes a step of purifying the crude product. Purification can be carried out by various methods commonly used in the art, such as extraction.

[0103] Although the present invention does not have any particular limitations on the grafting efficiency of the grafting reaction, a higher grafting efficiency is more advantageous for obtaining a polypropylene graft having desired properties through a one-step grafting reaction. Therefore, the grafting efficiency of the grafting reaction is preferably controlled to 5 to 100%, more preferably 5 to 80%. The term "grafting efficiency" is well known to those skilled in the art and refers to the total amount of alkenyl-containing polymerizable monomers on the graft per total amount of alkenyl-containing polymerizable monomers added to the reaction.

[0104] In the case of styrene monomers, the grafting efficiency of the grafting reaction is preferably controlled to 30 to 100%, more preferably 35 to 80%. In the case of alkenyl-containing silane monomers, the grafting efficiency of the grafting reaction is preferably controlled to 5 to 100%, more preferably 5 to 60%. In the case of acrylate monomers and any acrylic monomers, the grafting efficiency of the grafting reaction is preferably controlled to 30 to 100%, more preferably 35 to 80%. In the case of alkenyl-containing heterocyclic monomers, the grafting efficiency of the grafting reaction is preferably controlled to 30 to 100%, more preferably 35 to 80%.

[0105] The inert gas of the present invention can be any of a variety of inert gases commonly used in the art, including, but not limited to, nitrogen, argon.

[0106] A third aspect of the present invention provides a graft-modified polypropylene material for insulating use, obtainable by the above preparation method.

[0107] A fourth aspect of the present invention provides the use of the above graft-modified polypropylene material as an insulating material.

[0108] More preferably, the insulating material is a cable insulating material, preferably a DC cable insulating material.

[0109] More preferably, the insulating material is a cable insulation material.

[0110] The graft-modified polypropylene used in the present invention can be used directly as a base material for insulating materials without blending with other polymers.

[0111] A fifth aspect of the present invention provides a cable comprising at least one conductor and at least one electrical insulating layer surrounding the conductor, the material of the electrical insulating layer being a graft-modified polypropylene material.

[0112] The core of the present invention uses a novel material as the electrical insulation layer of the cable, and therefore the form and specific structure of the cable in the present invention are not particularly limited, and various cable forms (DC or AC, single-core or multi-core) and corresponding various structures conventional in the art can be used. In the cable of the present invention, except for the use of the novel graft-modified polypropylene material in the electrical insulation layer, other layer structures and other layer materials can be selected as conventional in the art.

[0113] The cable of the present invention may be a DC cable or an AC cable, preferably a DC cable, and more preferably the cable is a medium / high voltage DC cable or an extra-high voltage DC cable. In the present invention, low voltage (LV) refers to a voltage less than 1 kV, medium voltage (MV) refers to a voltage in the range of 1 kV to 40 kV, high voltage (HV) refers to a voltage greater than 40 kV, preferably greater than 50 kV, and extra-high voltage (EHV) refers to a voltage of at least 230 kV.

[0114] According to a preferred embodiment of the present invention, the cable has at least one cable core, and each cable core includes, from the inside to the outside, a conductor, an optional conductor shield layer, an electrical insulating layer, an optional electrical insulating shield layer, and an optional metallic shield layer. The conductor shield layer, the electrical insulating shield layer, and the metallic shield layer can be arranged as needed and are generally used for cables above 6 kV.

[0115] In addition to the above structure, the cable may further include an armor and / or sheath layer.

[0116] The cable of the present invention may be single-core or multi-core. In the case of a multi-core cable, the cable may further include a filling layer and / or a wrapping layer. The filling layer is formed by filling the spaces between the wire cores with a filling material. The wrapping layer covers the outside of all the wire cores, ensuring that the wire cores and the filling layer are round, preventing the wire cores from being scratched by the sheath, and providing a flame-retardant effect.

[0117] In the cable of the present invention, the conductor is a conductive element generally made of a metallic material, preferably aluminum, copper or other alloys containing one or more metal wires. The DC resistance and number of monofilaments of the conductor should meet the requirements of GB / T3956. Preferably, the conductor is 800 mm 2 It has a twisted round structure with a nominal cross-sectional area of ​​1000mm or less 2 The divided conductor structure has a nominal cross-sectional area of ​​170 or more, and the number of conductors is 170 or more.

[0118] In the cable of the present invention, the conductor shielding layer may be a cover layer made of polypropylene, polyolefin elastomer, carbon black, or other materials, and has a volume resistivity at 23°C of less than 1.0 Ω·m and a volume resistivity at 90°C of less than 3.5 Ω·m, a melt flow rate at 230°C under a 2.16 kg load of typically 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, more preferably 0.1 to 10 g / 10 min, and even more preferably 0.2 to 8 g / 10 min, a tensile strength of 12.5 MPa or greater, and an elongation at break of 150% or greater. The thickness of the thinnest point of the conductor shielding layer is 0.5 mm or greater, and the average thickness is 1.0 mm or greater.

[0119] In the cable of the present invention, the material of the electrical insulation layer is at least one graft-modified polypropylene material, which means that the base material constituting the electrical insulation layer is a graft-modified polypropylene material, and additional components, such as polymeric components or additives, preferably additives, such as any one or more selected from antioxidants, stabilizers, processing aids, flame retardants, water tree retarding additives, acid or ion scavengers, inorganic fillers, voltage stabilizers, and copper inhibitors, may be included in addition to the graft-modified polypropylene material. The types and amounts of additives used are conventional and known to those skilled in the art.

[0120] The method for producing the electrical insulation layer of the present invention may be a conventional method in the field of cable manufacturing, such as mixing the graft-modified polypropylene material with various optional additives, granulating the mixture in a twin-screw extruder, and then extruding the resulting granules in an extruder to obtain an electrical insulation layer. Generally, the conductor shielding material can be co-extruded with the graft-modified polypropylene material granules to form a structure of a conductor shielding layer + an electrical insulation layer, or a structure of a conductor shielding layer + an electrical insulation layer + an electrical insulation shielding layer. The specific operations can be carried out using conventional methods and processing conditions in the art.

[0121] Due to the use of graft-modified polypropylene material, the thickness of the electrical insulation layer may be only 50% to 95% of the nominal thickness value of the XLPE insulation layer in GB / T12706, and preferably the thickness of the electrical insulation layer is 70% to 90% of the nominal thickness value of the XLPE insulation layer in GB / T12706; the eccentricity is not more than 10%.

[0122] In the cable of the present invention, the electrical insulation layer may be a coating layer made of polypropylene, polyolefin elastomer, carbon black, or other materials, and has a volume resistivity at 23°C of less than 1.0 Ω-m and at 90°C of less than 3.5 Ω-m, a melt flow rate at 230°C under a 2.16 kg load of typically 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, more preferably 0.1 to 10 g / 10 min, and even more preferably 0.2 to 8 g / 10 min, a tensile strength of 12.5 MPa or greater, and an elongation at break of 150% or greater. The electrical insulation layer has a thickness at its thinnest point of 0.5 mm or greater and an average thickness of 1.0 mm or greater.

[0123] In the cable of the present invention, the metal shielding layer may be a copper strip shielding layer or a copper wire shielding layer.

[0124] In the cable of the present invention, the filling layer may be made of polymeric materials such as PE / PP / PVC or recycled rubber materials.

[0125] In the cable of the present invention, the packaging layer / sheath is a metal cover layer that is usually made of a copper wire metal cage, a lead or aluminum metal sleeve, etc., and wraps around the outer surface of the electrically insulating shielding layer, and is characterized by having a DC volume resistivity of 1000 Ω·m or less at room temperature.

[0126] In the cable of the present invention, the material of the sheath layer may be any one selected from polyvinyl chloride, polyethylene, and low-smoke halogen-free materials. The sheath layer includes not only an inner sheath layer but also an outer sheath layer.

[0127] The above-described structure of each layer can be formed by a conventional method in the art. For example, the conductive shielding layer, the electrical insulating layer, and the sheath layer can be formed by extrusion coating using an extruder, and the metallic shielding layer and the outer casing can be formed by winding.

[0128] The cable of the present invention can be prepared by various preparation methods commonly used in the art, and is not particularly limited in the present invention.

[0129] According to a specific embodiment of the present invention, the method for preparing the cable is as follows: Conductor preparation: A number of monofilament conductors (e.g., aluminum) are compacted and twisted to obtain a conductor core, or they are bundled together, and then the bundled monofilament conductors are twisted to obtain a conductor core.

[0130] Preparation of modified polypropylene particles: The modified polypropylene material is mixed with any additives and granulated by a twin-screw extruder.

[0131] Preparation of conductor shielding layer and electrical insulation layer: Conductor shielding material and modified polypropylene particles are co-extruded and coated on the outside of the conductor inner core using an extruder to form a conductor shielding layer + electrical insulation layer or a conductor shielding layer + electrical insulation layer + electrical insulation shielding layer (outer shielding layer).

[0132] Preparation of the metal shielding layer: A copper strip or copper wire is wound around the outside of the electrical insulating layer (electrical insulating shielding layer) to form a metal shielding layer.

[0133] Preparation of inner sheath layer: The sheath layer granules are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0134] Sheath preparation: Prepare the steel wire or steel strip sheath using galvanized steel / stainless steel / aluminum alloy, and wind a single-layer sheath to the left around the inner sheath layer, or wind a double-layer sheath inner layer to the right and an outer layer to the left, so that the steel wire or steel strip sheath is dense and the gaps between adjacent steel wires / steel strips are minimized.

[0135] Preparation of outer sheath layer: The sheath layer granules are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer. Finally, the cable is prepared.

[0136] The graft-modified polypropylene material of the present invention can take into account both mechanical and electrical properties at higher use temperatures, and is suitable for use under high temperature and high operating field strength conditions. In addition, compared with materials containing small molecule additives, the graft-modified polypropylene material of the present invention avoids the performance degradation caused by the migration of small molecules, and therefore has better stability.

[0137] The cable of the present invention can have a higher volume resistivity and stronger fracture resistance than conventional cables while still maintaining its mechanical properties. Meanwhile, the cable's mechanical properties can also meet the requirements for cable use. Under the conditions of ensuring the same voltage grade and insulation level, the electrical insulation layer made of graft-modified polypropylene material has advantages such as thinner thickness, better heat dissipation, and lighter weight than the electrical insulation layer of conventional cables. Therefore, the cable's application range is wider.

[0138] A sixth aspect of the present invention provides an insulating material, characterized in that the insulating material comprises at least one graft-modified polypropylene material as defined above.

[0139] Preferably, the content of the at least one graft-modified polypropylene material is 20 to 100% by weight, preferably 40 to 100% by weight, more preferably 60 to 100% by weight, even more preferably 80 to 100% by weight, and even more preferably 90 to 100% by weight, based on the weight of the insulating material.

[0140] Preferably, the insulating material further comprises additives such as one or more selected from antioxidants, stabilizers, processing aids, flame retardants, water tree retarding additives, acid or ion scavengers, inorganic fillers, voltage stabilizers, and copper inhibitors. The types and amounts of additives used are conventional and known to those skilled in the art.

[0141] Furthermore, the present invention also includes the embodiments described in the following items.

[0142] (Item 1) A method for producing an insulating material using a graft-modified polypropylene material, wherein the graft-modified polypropylene material contains structural units derived from a polypropylene copolymer and structural units derived from an alkenyl-containing polymerizable monomer, and the content of the structural units derived from the alkenyl-containing polymerizable monomer and in a grafted state in the graft-modified polypropylene material is 0.1 to 14 wt %, preferably 0.2 to 7.5 wt %, based on the weight of the graft-modified polypropylene material; The polypropylene copolymer has at least one of the following characteristics: The comonomer content is 0.5 to 40 mol%, preferably 0.5 to 30 mol%, more preferably 4 to 25 wt%, and even more preferably 4 to 22 wt%; the xylene soluble matter content is 2 to 80 wt%, preferably 18 to 75 wt%, more preferably 30 to 70 wt%, and even more preferably 30 to 67 wt%; the comonomer content in the xylene soluble matter is 10 to 70 wt%, preferably 10 to 50 wt%, and more preferably 20 to 35 wt%; and the intrinsic viscosity ratio of the xylene soluble matter to the polypropylene copolymer is 0.3 to 5, preferably 0.5 to 3, and even more preferably 0.8 to 1.3.

[0143] (Item 2) Item 1. The method according to Item 1, wherein the polypropylene copolymer has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 60 g / 10 min, preferably 0.05 to 35 g / 10 min, more preferably 0.5 to 15 g / 10 min; a melting point Tm of 100°C or higher, preferably 110 to 180°C, more preferably 110 to 170°C, even more preferably 120 to 170°C, and still more preferably 120 to 166°C; a weight average molecular weight of preferably 20 × 10 4 ~60×10 4 g / mol.

[0144] (Item 3) 3. The method according to item 1 or 2, wherein the comonomer of the polypropylene copolymer is at least one selected from C2-C8 α-olefins other than propylene; preferably, the comonomer of the polypropylene copolymer is at least one selected from ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene; more preferably, the comonomer of the polypropylene copolymer is ethylene and / or 1-butene; and even more preferably, the polypropylene copolymer consists of propylene and ethylene.

[0145] (Item 4) 4. The method according to any one of items 1 to 3, wherein the graft-modified polypropylene material is prepared by a solid-state graft reaction of a polypropylene copolymer and an alkenyl-containing polymerizable monomer.

[0146] (Item 5) 5. The method according to any one of items 1 to 4, wherein the graft-modified polypropylene material has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, and further preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, preferably 20 to 1000 MPa, more preferably 50 to 600 MPa; The elongation at break is 200% or more, preferably 300% or more.

[0147] (Item 6) 6. The method according to any one of items 1 to 5, wherein the graft-modified polypropylene material has at least one of the following characteristics: The use temperature of the graft-modified polypropylene material is 90°C or higher, preferably 90 to 160°C; The breakdown field strength E of the graft-modified polypropylene material at 90°C g is 180 kV / mm or more, preferably 180 to 800 kV / mm; The breakdown field strength E of the graft-modified polypropylene material at 90°C g and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 0.7%, preferably 0.8 to 50%, more preferably 2 to 35%, and even more preferably 5 to 25%; DC volume resistivity ρ of the graft-modified polypropylene material at 90°C and 15 kV / mm electric field strength vg is 6 x 10 12 Ω.m or more, preferably 6×10 12 Ω.m~1.0×10 20 is Ω.m; The DC volume resistivity ρ of the polypropylene copolymer at 90°C and a field strength of 15 kV / mm v The direct current volume resistivity ρ of the graft-modified polypropylene material at 90 ° C and 15 kV / mm electric field strength vg The ratio (ρ vg / ρ v ) exceeds 1, and is preferably 1.1 to 50, more preferably 1.15 to 20, and even more preferably 1.2 to 10. It is 2 to 10.

[0148] (Item 7) 7. The method according to any one of items 1 to 6, wherein the alkenyl-containing polymerizable monomer is at least one selected from monomers having a structure represented by formula 1:

[0149] [ka]

[0150] In formula 1, R b , R c , R d are each independently selected from H, substituted or unsubstituted alkyl; R ais selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted ester group, substituted or unsubstituted carboxyl, substituted or unsubstituted cycloalkyl or heterocyclyl, cyano, substituted or unsubstituted silyl.

[0151] (Item 8) R b , R c , R d are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R a Substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C6-C 20 Aryl, substituted or unsubstituted C1-C 20 Ester groups, substituted or unsubstituted C1-C 20 Carboxyl, substituted or unsubstituted C3-C 20 Cycloalkyl or heterocyclyl, cyano, substituted or unsubstituted C3-C 20 silyl, the substituents of which are halogen, hydroxy, amino, C1-C 12 Alkyl, C3-C6 cycloalkyl, C1-C 12 Alkoxy, C1-C 12 8. The method according to item 7, wherein the aryl group is acyloxy.

[0152] (Item 9) R b , R c , R d are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R a is selected from a group represented by formula 2, a group represented by formula 3, a group represented by formula 4, a group represented by formula 5, a group represented by formula 6, a combination of a group represented by formula 6 and a group represented by formula 7, and a heterocyclic group:

[0153] [ka]

[0154] In formula 2, R 4 -R 8 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, Preferably, R 4 -R 8 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy;

[0155] [ka]

[0156] In formula 3, R4-R 10 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, Preferably, R4-R 10 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, and C1-C6 alkoxy;

[0157] [ka]

[0158] In formula 4, R4'-R 10 ' are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C1-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 amine groups, Preferably, R4'-R 10 each ' is independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, and C1-C6 alkoxy;

[0159] [ka]

[0160] In formula 5, R', R'', and R''' are each independently Substituted or unsubstituted C1-C 12 Straight chain alkyl, Substituted or unsubstituted C3-C 12 Branched alkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 acyloxy; Preferably, R1 is a C2-C6 alkenyl, preferably a monounsaturated alkenyl; R2, R3, and R4 are each independently Substituted or unsubstituted C1-C6 straight chain alkyl, Substituted or unsubstituted selected from C3-C6 branched alkyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C1-C6 acyloxy;

[0161] [ka]

[0162] [ka]

[0163] In formula 6, R m is substituted or unsubstituted, C1-C 20 Straight chain alkyl, C3-C 20 Branched alkyl, C3-C 12 Cycloalkyl, C3-C 12 Epoxy alkyl, C3-C 12 epoxyalkylalkyl, the substituents of which are at least one selected from halogen, amino, and hydroxy; 8. The method according to item 7, wherein the heterocyclic group is selected from imidazolyl, pyrazolyl, carbazolyl, pyrrolidinonyl, pyridyl, piperidinyl, caprolactam group, pyrazinyl, thiazolyl, purinyl, morpholinyl, oxazolinyl.

[0164] (Item 10) the graft-modified polypropylene material is an aromatic olefin graft-modified polypropylene material; the alkenyl-containing polymerizable monomer is a styrene monomer; the content of the structural units derived from the styrene monomer and in a grafted state in the aromatic olefin-grafted polypropylene material is 0.5 to 14 wt %, preferably 1 to 7.5 wt %, more preferably 1.5 to 5 wt %, based on the weight of the aromatic olefin-grafted polypropylene material; Preferably, the styrene monomer is at least one selected from a monomer having a structure represented by formula 8, a monomer having a structure represented by formula 9, and a monomer having a structure represented by formula 10;

[0165] [ka]

[0166] In formula 8, R 1 , R 2 , R 3 are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R 4 -R 8 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C12 amine groups, Preferably, R 1 , R 2 , R 3 are each independently selected from H, substituted or unsubstituted C1-C3 alkyl, and R 4 -R 8 are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy;

[0167] [ka]

[0168] In formula 9, R1, R2, and R3 are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R4-R 10 are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 selected from amine groups; Preferably, R1, R2, R3 are each independently selected from H, substituted or unsubstituted C1-C3 alkyl, and R4-R 10are each independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, C1-C6 alkoxy;

[0169] [ka]

[0170] In formula 10, R1', R2', and R3' are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R4'-R 10 ' are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C1-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted C1-C 12 Alkoxy, substituted or unsubstituted C1-C 12 Ester groups, substituted or unsubstituted C1-C 12 amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate, sulfonate, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 12 Alkoxy, C1-C 12 Ester group, C1-C 12 selected from amine groups; Preferably, R1', R2', and R3' are each independently selected from H, substituted or unsubstituted C1-C3 alkyl, and R4'-R 10 each ' is independently selected from H, halogen, hydroxy, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituents are selected from halogen, hydroxy, amino, C1-C6 alkyl, C1-C6 alkoxy; Preferably, the styrene monomer is at least one selected from styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, mono- or poly-substituted styrene, mono- or poly-substituted α-methylstyrene, mono- or poly-substituted 1-vinylnaphthalene, and mono- or poly-substituted 2-vinylnaphthalene; the substituents thereof are preferably at least one selected from halogen, hydroxy, amino, phosphate group, sulfonate group, C1-C8 linear alkyl, C3-C8 branched alkyl or cycloalkyl, C1-C6 linear alkoxy, C3-C8 branched alkoxy or cycloalkoxy, C1-C8 linear ester group, C3-C8 branched ester group or cyclic ester group, C1-C8 linear amine group, and C3-C8 branched amine group or cyclic amine group; More preferably, the styrene monomer is at least one selected from styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene and 4-methylstyrene.

[0171] (Item 11) Item 11. The method according to item 10, wherein the aromatic olefin graft modified polypropylene material has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, preferably 0.05 to 20 g / 10 min, further preferably 0.1 to 10 g / 10 min, and further preferably 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, preferably 20 to 1000 MPa, more preferably 50 to 600 MPa; The elongation at break is 200% or more, preferably 300% or more.

[0172] (Item 12) Item 11. The method according to item 10, wherein the aromatic olefin graft modified polypropylene material has at least one of the following characteristics: The use temperature of the aromatic olefin graft-modified polypropylene material is 90°C or higher, preferably 90 to 160°C; The breakdown field strength E of the aromatic olefin grafted polypropylene material at 90°C g is 200 kV / mm or more, preferably 200 to 800 kV / mm; The breakdown field strength E of the aromatic olefin grafted polypropylene material at 90°C g and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 1.5%, preferably 1.6 to 40%, more preferably 5 to 30%, and even more preferably 10 to 20%; DC volume resistivity ρ of the aromatic olefin grafted modified polypropylene material at 90°C and 15 kV / mm electric field strength vg is 1.0×10 13 Ω.m or more, preferably 1.5×10 13 Ω.m~1.0×10 20 is Ω.m; DC volume resistivity ρ of the aromatic olefin grafted modified polypropylene material at 90°C and 15 kV / mm electric field strength v The direct current volume resistivity ρ of the graft-modified polypropylene material at 90 ° C and 15 kV / mm electric field strength vg The ratio (ρ vg / ρ v ) exceeds 1, and is preferably 1.5 to 50, more preferably 2 to 20, and even more preferably 3 to 10.

[0173] (Item 13) 13. The method according to any one of items 1 to 12, wherein the insulating material is a cable insulating material, preferably a DC cable insulating material.

[0174] (Item 14) Item 14. The method according to item 13, wherein the insulating material is a cable insulation layer material.

[0175] Additional features and advantages of the present invention are described in the detailed description of specific embodiments that follow.

[0176] [Mode for Carrying Out the Invention] Below is a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are intended to be illustrative and explanatory only and are not intended to be limiting of the present invention.

[0177] In the following examples and comparative examples: 1. Determination of comonomer content in polypropylene copolymer: Comonomer content was measured by quantitative Fourier transform infrared (FTIR) spectroscopy. The correlation of measured comonomer content was calibrated by quantitative nuclear magnetic resonance (NMR) spectroscopy. 13 Calibration methods based on results obtained from C-NMR spectroscopy were performed according to conventional methods in the art.

[0178] 2. Determination of the xylene solubles content in polypropylene copolymer, the comonomer content in xylene solubles, and the intrinsic viscosity ratio of xylene solubles to polypropylene copolymer: Measurements were made using a Polymer Char CRYST-EX instrument according to the following method: dissolve in trichlorobenzene solvent by heating to 150°C, hold for 90 minutes, sample and test, then cool to 35°C, hold for 70 minutes, sample and test.

[0179] 3. Measurement of weight average molecular weight of polypropylene copolymer: The sample was dissolved in 1,2,4-trichlorobenzene at a concentration of 1.0 mg / ml and analyzed by high-temperature GPC using a Polymer Laboratory PL-GPC 220 gel permeation chromatograph. The measurement temperature was 150°C and the solution flow rate was 1.0 ml / min. A calibration curve was plotted using the molecular weight of polystyrene as an internal standard, and the molecular weight and molecular weight distribution of the sample were calculated as a function of the elution time.

[0180] 4.Melt Flow Rate (MFR) Measurement: The measurements were carried out at 230°C under a load of 2.16 kg using a CEAST 7026 type melt indexer in accordance with the method specified in GB / T3682-2018.

[0181] 5. Melting point (Tm) measurement: The melting and crystallization processes of the materials were analyzed by differential scanning calorimetry. The specific procedure was as follows: Under nitrogen protection, 5-10 mg samples were measured using a three-step temperature ramp from 20°C to 200°C. The melting and crystallization processes of the materials were reflected in the changes in heat flow, and the melting point Tm was calculated.

[0182] 6. Measurement of grafting efficiency GE and parameter M1: 2–4 g of the grafted product was placed in a Soxhlet extractor and extracted with an organic solvent (ethyl acetate for aromatic olefin monomers, acrylate monomers, and heterocyclic monomers; acetone for silane monomers) for 24 h to remove unreacted monomers and homopolymers. The pure grafted product was then dried and weighed. The parameter M1 and grafting efficiency GE were then calculated.

[0183] The parameter M1 represents the content of grafted structural units derived from alkenyl-containing polymerizable monomers in the graft-modified polypropylene material. The calculation formulas for M1 and GE in the present invention are as follows:

[0184]

number

[0185]

number

[0186] In the above formula, w0 represents the mass of the PP matrix, w1 represents the mass of the graft product before extraction, w2 represents the mass of the graft product after extraction, and w3 represents the mass of the added alkenyl-containing polymerizable monomer.

[0187] 7. DC volume resistivity measurement: The measurements were carried out according to the method specified in GB / T1410-2006.

[0188] 8. Breakdown field strength measurement: The measurements were carried out according to the method specified in GB / T1408-2006.

[0189] 9. Tensile strength measurement: The measurements were carried out according to the method specified in GB / T1040.2-2006.

[0190] 10. Flexural modulus measurement: The measurements were carried out according to the method specified in GB / T9341-2008.

[0191] 11. Measurement of elongation at break: The measurements were carried out according to the method specified in GB / T1040-2006.

[0192] 12. Measurement of dielectric constant and dielectric loss tangent: The measurements were carried out according to the method specified in GB / T1409-2006.

[0193] 13. Measurement of cable main insulation conductivity (resistivity) ratio: The measurements were made according to the method specified in Appendix A of TICW 7.1-2012. The cable's main insulation conductivity ratio is equal to the cable's main insulation conductivity at 90°C divided by the cable's main insulation conductivity at 30°C.

[0194] 14. Field distortion measurement: Cable insulation space charge injection testing was performed according to the method specified in Appendix B of TICW 7.1-2012.

[0195] 15. DC withstand voltage test measurement: The cable was continuously pressurized at 1.85 times the negative rated voltage for 2 hours at room temperature. Breakdown and discharge events did not mean pass, otherwise it meant fail.

[0196] 16. Duty cycle measurement: The cables were heated to 90°C at their rated operating temperature and then subjected to a voltage of 1.85 times the rated voltage for 8 hours. The voltage was then removed and the cables were allowed to cool naturally for 16 hours. This cycle was repeated for 12 days. Failure did not constitute a pass.

[0197] The materials used in the examples are listed in Table A below.

[0198] [Table 1]

[0199] *Polypropylene copolymer 1: Polypropylene copolymer used in Examples 1A, 1B, 1C, and 1D, and Comparative Examples 2A, 3A, 2B, 3B, 2C, 3C, 2D, and 3D *Polypropylene copolymer 2: the polypropylene copolymer used in Examples 2A, 2B, 2C, and 2D *Polypropylene copolymer 3: the polypropylene copolymer used in Examples 3A, 3B, 3C, and 3D *Polypropylene copolymer 4: Polypropylene copolymer used in Examples 4A, 4B, 4C, and 4D *Polypropylene copolymer 5: Polypropylene copolymer used in Examples 5A, 5B, 5C, and 5D *Polypropylene copolymer 6: Polypropylene copolymer used in Examples 6A, 6B, 6C, and 6D Example 1A A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2 g of dibenzoyl peroxide and 100 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40 °C for 4 hours, heated to 95 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-styrene material product A1. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0200] Example 2A A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 14.7 wt%, xylene solubles content of 41.7 wt%, comonomer content in the xylene solubles of 34.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.91, and weight average molecular weight of 36.6 × 10 4 The molecular weight (MFR) was 1.54 g / mol under a 2.16 kg load at 230 °C, Tm = 164.9 °C, breakdown field strength at 90 °C was 248 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 7.25E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2.8 g of lauroyl peroxide and 150 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 60 °C for 2 hours, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-styrene material product A2. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0201] Example 3A A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 20.1 wt%, xylene solubles content of 66.1 wt%, comonomer content in the xylene solubles of 29.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.23, and weight average molecular weight of 53.8 × 10 4 The molecular weight (MFR) was 0.51 g / mol under a 2.16 kg load at 230 °C, Tm = 142.5 °C, breakdown field strength at 90 °C was 176 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 5.63E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 1.5 g of lauroyl peroxide and 50 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 60 °C for 2 hours, heated to 85 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-styrene material product A3. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0202] Example 4A A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 9.3 wt%, xylene solubles content of 21.0 wt%, comonomer content in the xylene solubles of 35.4 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.68, and weight average molecular weight of 30.4 × 10 4The molecular weight (MFR) was 5.69 g / mol under a 2.16 kg load at 230 °C, Tm = 163.0 °C, breakdown field strength at 90 °C was 288 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.32E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 7.0 g of tert-butyl peroxy(2-ethylhexanoate) and 200 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 60 °C for 1 hour, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-styrene material product A4. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0203] Example 5A A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 4.8 wt%, xylene solubles content of 19.2 wt%, comonomer content in the xylene solubles of 17.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.04, and weight average molecular weight of 29.2 × 10 4The polypropylene copolymer powder had a molecular weight of 5.37 g / mol, a MFR of 5.37 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 163.3 °C, a breakdown field strength of 322 kV / mm at 90 °C, and a DC volume resistivity of 1.36E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 4.0 g of dibenzoyl peroxide was dissolved in 100 g of acetone, and the resulting acetone solution was added to the reaction system. The reaction system was heated to 40 °C, and the acetone was removed by nitrogen purging for 30 minutes. Next, 100 g of p-methylstyrene was added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 60 °C for 1 hour, and then heated to 100 °C and reacted for 1 hour. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-gp-methylstyrene material product A5. Various performance parameters of the obtained product were tested. The results are shown in Table 1.

[0204] Example 6A A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 12.6 wt%, xylene solubles content of 30.6 wt%, comonomer content in the xylene solubles of 43.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.84, and weight average molecular weight of 27.1 × 10 4The polypropylene copolymer powder had a molecular weight of 8.46 g / mol, a MFR of 8.46 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 162.0 °C, a breakdown field strength of 261 kV / mm at 90 °C, and a DC volume resistivity of 9E12 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 3.0 g of dibenzoyl peroxide was dissolved in 100 g of styrene and 100 g of surfactant toluene to form a solution. The solution was mixed with stirring for 30 minutes and allowed to swell at 60 °C for 0.5 hours. 4 kg of dispersant water was added, and the reaction system was heated to 110 °C and allowed to react for 0.5 hours. After the reaction was complete, the reaction product was cooled, filtered to remove the dispersant water, and dried under reduced pressure at 70°C for 10 hours to obtain polypropylene-g-styrene material product A6. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0205] Example 7A 2.0 kg of the base polypropylene copolymer powder from Example 1A was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 0.6 g of dibenzoyl peroxide and 30 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40°C for 4 hours, heated to 95°C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled with a nitrogen purge to obtain polypropylene-g-styrene material product A7. The resulting product was tested for various performance parameters. The results are shown in Table 1.

[0206] Example 8A 2.0 kg of the base polypropylene copolymer powder from Example 1A was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 4 g of dibenzoyl peroxide and 200 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40°C for 4 hours, heated to 95°C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled with a nitrogen purge to obtain polypropylene-g-styrene material product A8. The resulting product was tested for various performance parameters. The results are shown in Table 1.

[0207] <Comparative Example 1A> Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of T30S powder (breakdown field strength at 90 °C: 347 kV / mm, DC volume resistivity at 90 °C and 15 kV / mm: 1.18E13 Ω·m) was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen exchange. 2 g of dibenzoyl peroxide and 100 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40 °C for 4 hours, heated to 95 °C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-styrene material product CA1. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0208] <Comparative example 2A> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 12 g of dibenzoyl peroxide and 600 g of styrene were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40 °C for 4 hours, heated to 95 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-styrene material product CA2. Various performance parameters of the resulting product were tested. The results are shown in Table 1.

[0209] <Comparative example 3A> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The polypropylene copolymer powder had a molecular weight of 1.21 g / mol, a melt flow rate (MFR) of 1.21 g / 10 min under a 2.16 kg load at 230 °C, a temperature (Tm) of 143.4 °C, a breakdown field strength of 236 kV / mm at 90 °C, and a DC volume resistivity of 1.16E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and mixed with 100 g of polystyrene GPPS-123 in a screw extruder to obtain Blend CA3. The resulting product was tested for various performance parameters. The results are shown in Table 1.

[0210] Example 1B A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2.5 g of lauroyl peroxide and 50 g of vinyltriethoxysilane were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 40 °C for 1 hour, heated to 90 °C, and reacted for 4 hours. After the reaction was complete, the reaction product was purged with nitrogen and cooled to obtain polypropylene-g-vinyltriethoxysilane material product B1. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0211] Example 2B A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 14.7 wt%, xylene solubles content of 41.7 wt%, comonomer content in the xylene solubles of 34.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.91, and weight average molecular weight of 36.6 × 10 4The molecular weight (MFR) was 1.54 g / mol under a 2.16 kg load at 230 °C, Tm = 164.9 °C, breakdown field strength at 90 °C was 248 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 7.25E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 0.9 g of dibenzoyl peroxide and 20 g of vinyltriethoxysilane were added, and the reaction mixture was mixed with stirring for 60 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was complete, the reaction product was purged with nitrogen and cooled to obtain polypropylene-g-vinyltriethoxysilane material product B2. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0212] Example 3B A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 20.1 wt%, xylene solubles content of 66.1 wt%, comonomer content in the xylene solubles of 29.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.23, and weight average molecular weight of 53.8 × 10 4The molecular weight (MFR) was 0.51 g / mol under a 2.16 kg load at 230 °C, Tm = 142.5 °C, breakdown field strength at 90 °C was 176 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 5.63E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 6.0 g of lauroyl peroxide and 100 g of vinyltriethoxysilane were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 60 °C for 1 hour, heated to 90 °C, and reacted for 4 hours. After the reaction was complete, the reaction product was purged with nitrogen and cooled to obtain polypropylene-g-vinyltriethoxysilane material product B3. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0213] Example 4B A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 9.3 wt%, xylene solubles content of 21.0 wt%, comonomer content in the xylene solubles of 35.4 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.68, and weight average molecular weight of 30.4 × 10 4The polypropylene copolymer powder had a molecular weight of 5.69 g / mol at 230 °C under a load of 2.16 kg, a thermal conductivity of 163.0 °C, a breakdown field strength of 288 kV / mm at 90 °C, and a DC volume resistivity of 1.32E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and deoxygenated by nitrogen substitution. 4.5 g of tert-butylperoxy(2-ethylhexanoate) and 120 g of vinyltriisopropoxysilane were added, and the reaction mixture was mixed with stirring for 60 minutes, heated to 100 °C, and reacted for 1.5 hours. After completion of the reaction, the reaction product was purged with nitrogen and cooled to obtain polypropylene-g-vinyltriisopropoxysilane material product B4. The resulting product was tested for various performance parameters, and the results are shown in Table 2.

[0214] Example 5B A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 4.8 wt%, xylene solubles content of 19.2 wt%, comonomer content in the xylene solubles of 17.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.04, and weight average molecular weight of 29.2 × 10 4The molecular weight (MFR) was 5.37 g / mol under a 2.16 kg load at 230 °C, Tm = 163.3 °C, breakdown field strength at 90 °C was 322 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.36E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 3.7 g of lauroyl peroxide was dissolved in 70 g of acetone, and the resulting acetone solution was added to the reaction system, heated to 40 °C, and the acetone was removed by nitrogen purging for 30 minutes. Next, 75 g of vinyltriethoxysilane was added, and the reaction mixture was mixed with stirring for 30 minutes, heated to 85 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was purged with nitrogen and cooled to obtain polypropylene-g-vinyltriethoxysilane material product B5. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0215] Example 6B A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 12.6 wt%, xylene solubles content of 30.6 wt%, comonomer content in the xylene solubles of 43.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.84, and weight average molecular weight of 27.1 × 10 4The sample had a molecular weight of 8.46 g / mol, a MFR of 8.46 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 162.0 °C, a breakdown field strength of 261 kV / mm at 90 °C, and a DC volume resistivity of 9E12 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 5.0 g of lauroyl peroxide was dissolved in 100 g of vinyltrimethoxysilane and 50 g of surfactant toluene to form a solution. The solution was mixed with stirring for 30 minutes, heated to 95 °C, and then 4 kg of dispersant water was added at 95 °C. The reaction was allowed to proceed for 0.75 hours. After the reaction was complete, the reaction product was cooled, filtered to remove the dispersant water, and vacuum dried at 70°C for 10 hours to obtain polypropylene-g-vinyltrimethoxysilane material product B6. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0216] Example 7B 2.0 kg of the base polypropylene copolymer powder from Example 1B was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 7.5 g of lauroyl peroxide and 175 g of vinyltriethoxysilane were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 40°C for 1 hour, heated to 90°C, and reacted for 4 hours. After the reaction was complete, the reaction product was purged with nitrogen and cooled to yield polypropylene-g-vinyltriethoxysilane material product B7. The resulting product was tested for various performance parameters. The results are shown in Table 2.

[0217] <Comparative example 1B> After sieving to remove fine powders smaller than 40 mesh, 2.0 kg of T30S powder (breakdown field strength at 90 °C: 347 kV / mm, DC volume resistivity at 90 °C and 15 kV / mm: 1.18E13 Ω·m) was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2.5 g of lauroyl peroxide and 50 g of vinyltriethoxysilane were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40 °C for 1 hour, heated to 90 °C, and reacted for 4 hours. After the reaction was complete, the reaction product was purged with nitrogen and cooled to obtain polypropylene-g-vinyltriethoxysilane material product CB1. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0218] <Comparative Example 2B> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 20 g of lauroyl peroxide and 400 g of vinyltriethoxysilane were added, and the reaction mixture was mixed with stirring for 60 minutes, swelled at 40 °C for 1 hour, heated to 90 °C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled to obtain polypropylene-g-vinyltriethoxysilane material product CB2. Various performance parameters of the resulting product were tested. The results are shown in Table 2.

[0219] <Comparative example 3B> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm was 143.4 °C, the breakdown field strength at 90 °C was 236 kV / mm, and the DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and mixed with 50 g of polyvinyltriethoxysilane in a screw extruder to obtain Blend CB3. The resulting product was tested for various performance parameters. The results are shown in Table 2.

[0220] Preparation of polyvinyltriethoxysilane: 10 g of lauroyl peroxide and 200 g of vinyltriethoxysilane were dispersed in 800 ml of pure water, mixed with stirring, heated to 90°C, and reacted for 4 hours. After the reaction was completed, the reaction system was cooled to room temperature, filtered, and dried to obtain 125 g of polyvinyltriethoxysilane.

[0221] Example 1C A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2.5 g of dibenzoyl peroxide and 80 g of glycidyl methacrylate were added, and the reaction mixture was mixed with stirring for 30 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-glycidyl methacrylate material product C1. Various performance parameters of the resulting product were tested. The results are shown in Table 3.

[0222] Example 2C A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 14.7 wt%, xylene solubles content of 41.7 wt%, comonomer content in the xylene solubles of 34.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.91, and weight average molecular weight of 36.6 × 10 4 The molecular weight (MFR) was 1.54 g / mol under a 2.16 kg load at 230 °C, Tm = 164.9 °C, breakdown field strength at 90 °C was 248 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 7.25E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 1.2 g of dibenzoyl peroxide and 40 g of glycidyl methacrylate were added, and the reaction mixture was mixed with stirring for 30 minutes, heated to 95 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-glycidyl methacrylate material product C2. Various performance parameters of the resulting product were tested. The results are shown in Table 3.

[0223] Example 3C A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 20.1 wt%, xylene solubles content of 66.1 wt%, comonomer content in the xylene solubles of 29.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.23, and weight average molecular weight of 53.8 × 10 4 The molecular weight (MFR) was 0.51 g / mol under a 2.16 kg load at 230 °C, Tm = 142.5 °C, breakdown field strength at 90 °C was 176 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 5.63E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 3.5 g of dibenzoyl peroxide and 125 g of glycidyl methacrylate were added, and the reaction mixture was mixed with stirring for 30 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-glycidyl methacrylate material product C3. Various performance parameters of the resulting product were tested, and the results are shown in Table 3.

[0224] Example 4C A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 9.3 wt%, xylene solubles content of 21.0 wt%, comonomer content in the xylene solubles of 35.4 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.68, and weight average molecular weight of 30.4 × 10 4The polypropylene copolymer powder had a molecular weight of 5.69 g / mol, a MFR of 5.69 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 163.0 °C, a breakdown field strength of 288 kV / mm at 90 °C, and a DC volume resistivity of 1.32E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and deoxygenated by nitrogen substitution. 2.8 g of tert-butyl peroxy(2-ethylhexanoate) and 100 g of methyl methacrylate were added, and the reaction mixture was mixed with stirring for 30 minutes, heated to 95 °C, and 3.0 kg of dispersant (pure water) was added at 95 °C. The reaction was allowed to proceed for 4 hours. After the reaction was complete, the reaction product was filtered to remove the dispersant water, dried under reduced pressure at 70°C for 10 hours, and then cooled to obtain polypropylene-g-methyl methacrylate material product C4. Various performance parameters of the resulting product were tested. The results are shown in Table 3.

[0225] Example 5C A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 4.8 wt%, xylene solubles content of 19.2 wt%, comonomer content in the xylene solubles of 17.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.04, and weight average molecular weight of 29.2 × 10 4The polypropylene copolymer powder had a molecular weight of 5.37 g / mol, a MFR of 5.37 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 163.3 °C, a breakdown field strength of 322 kV / mm at 90 °C, and a DC volume resistivity of 1.36E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 1.3 g of dibenzoyl peroxide was dissolved in 70 g of acetone, and the resulting acetone solution was added to the reaction system, heated to 40 °C, and the acetone was removed by nitrogen purging for 30 minutes. 50 g of butyl acrylate was then added, and the reaction mixture was mixed with stirring for 30 minutes, heated to 100 °C, and reacted for 1 hour. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-butyl acrylate material product C5. Various performance parameters of the resulting product were tested. The results are shown in Table 3.

[0226] Example 6C A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 12.6 wt%, xylene solubles content of 30.6 wt%, comonomer content in the xylene solubles of 43.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.84, and weight average molecular weight of 27.1 × 10 4The polypropylene copolymer powder had a molecular weight of 8.46 g / mol, a MFR of 8.46 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 162.0 °C, a breakdown field strength of 261 kV / mm at 90 °C, and a DC volume resistivity of 9E12 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and deoxygenated by nitrogen substitution. 0.8 g of lauroyl peroxide was dissolved in 30 g of methyl methacrylate and 40 g of surfactant toluene to form a solution. The solution was mixed with stirring for 30 minutes, heated to 85 °C, and 4 kg of dispersant water was added at 85 °C. The reaction was allowed to proceed for 1.5 hours. After the reaction was complete, the reaction product was cooled, filtered to remove the dispersant water, and vacuum dried at 70°C for 10 hours to obtain polypropylene-g-methyl methacrylate material product C6. Various performance parameters of the resulting product were tested. The results are shown in Table 3.

[0227] Example 7C 2.0 kg of the base polypropylene copolymer powder from Example 1C was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 5.0 g of dibenzoyl peroxide and 180 g of glycidyl methacrylate were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 40°C for 1 hour, heated to 90°C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled with a nitrogen purge to obtain polypropylene-g-glycidyl methacrylate material product C7. The resulting product was tested for various performance parameters. The results are shown in Table 3.

[0228] Example 8C 2.0 kg of the base polypropylene copolymer powder from Example 1C was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 1.5 g of dibenzoyl peroxide, 40 g of methyl acrylate, and 10 g of acrylic acid were added, and the reaction mixture was stirred for 30 minutes, heated to 90°C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled with a nitrogen purge to obtain polypropylene-g-methyl acrylate / acrylic acid material product C8. The resulting product was then tested for various performance parameters. The results are shown in Table 3.

[0229] <Comparative example 1C> After sieving to remove fine particles smaller than 40 mesh, 2.0 kg of T30S powder (breakdown field strength at 90 °C: 347 kV / mm, DC volume resistivity at 90 °C and 15 kV / mm: 1.18E13 Ω·m) was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2.5 g of dibenzoyl peroxide and 80 g of glycidyl methacrylate were added, and the reaction mixture was mixed with stirring for 60 minutes, heated to 90 °C, and reacted for 4 hours. After completion of the reaction, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-glycidyl methacrylate product CC1. The resulting product was tested for various performance parameters. The results are shown in Table 3.

[0230] <Comparative Example 2C> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4The polypropylene copolymer powder had a molecular weight of 1.21 g / mol, a MFR of 1.21 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 143.4 °C, a breakdown field strength of 236 kV / mm at 90 °C, and a DC volume resistivity of 1.16E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 6 g of dibenzoyl peroxide and 225 g of glycidyl methacrylate were added, and the reaction mixture was mixed with stirring for 60 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-glycidyl methacrylate material product CC2. Various performance parameters of the resulting product were tested. The results are shown in Table 3.

[0231] <Comparative example 3C> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The polymer had a molecular weight of 1.21 g / mol, a MFR of 1.21 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 143.4 °C, a breakdown field strength of 236 kV / mm at 90 °C, and a DC volume resistivity of 1.16E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 500 g of the above base polypropylene copolymer powder was weighed and mixed with 20 g of poly(glycidyl methacrylate) in a screw extruder to obtain Blend CC3. The resulting product was tested for various performance parameters. The results are shown in Table 3.

[0232] Example 1D A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 1.2 g of dibenzoyl peroxide and 40 g of 4-vinylpyridine were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 50 °C for 30 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-4-vinylpyridine material product D1. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0233] Example 2D A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 14.7 wt%, xylene solubles content of 41.7 wt%, comonomer content in the xylene solubles of 34.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.91, and weight average molecular weight of 36.6 × 10 4The molecular weight (MFR) was 1.54 g / mol under a 2.16 kg load at 230 °C, Tm = 164.9 °C, breakdown field strength at 90 °C was 248 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 7.25E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 2.2 g of dibenzoyl peroxide and 100 g of 4-vinylpyridine were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 50 °C for 60 minutes, heated to 95 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-4-vinylpyridine material product D2. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0234] Example 3D A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 20.1 wt%, xylene solubles content of 66.1 wt%, comonomer content in the xylene solubles of 29.5 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.23, and weight average molecular weight of 53.8 × 10 4The molecular weight (MFR) was 0.51 g / mol under a 2.16 kg load at 230 °C, Tm = 142.5 °C, breakdown field strength at 90 °C was 176 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 5.63E12 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 4.5 g of dibenzoyl peroxide and 150 g of 4-vinylpyridine were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 50 °C for 30 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-4-vinylpyridine material product D3. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0235] Example 4D A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 9.3 wt%, xylene solubles content of 21.0 wt%, comonomer content in the xylene solubles of 35.4 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.68, and weight average molecular weight of 30.4 × 10 4The polypropylene copolymer powder had a molecular weight of 5.69 g / mol, a MFR of 5.69 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 163.0 °C, a breakdown field strength of 288 kV / mm at 90 °C, and a DC volume resistivity of 1.32E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and deoxygenated by nitrogen substitution. 2 g of tert-butyl peroxy(2-ethylhexanoate) and 40 g of 1-vinylimidazole were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 55 °C for 2 hours, heated to 95 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-1-vinylimidazole material product D4. The resulting product was tested for various performance parameters and the results are shown in Table 4.

[0236] Example 5D A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 4.8 wt%, xylene solubles content of 19.2 wt%, comonomer content in the xylene solubles of 17.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.04, and weight average molecular weight of 29.2 × 10 4The polypropylene copolymer powder had a molecular weight of 5.37 g / mol, a MFR of 5.37 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 163.3 °C, a breakdown field strength of 322 kV / mm at 90 °C, and a DC volume resistivity of 1.36E13 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 3 g of dibenzoyl peroxide was dissolved in 100 g of acetone, and the resulting acetone solution was added to the reaction system, heated to 40 °C, and the acetone was removed by nitrogen purging for 30 minutes. 60 g of pf N-vinylpyrrolidone was then added. The reaction mixture was mixed with stirring for 30 minutes, heated to 100 °C, and reacted for 1 hour. After the reaction was completed, the reaction product was cooled to obtain polypropylene-N-vinylpyrrolidone material product D5. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0237] Example 6D A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 12.6 wt%, xylene solubles content of 30.6 wt%, comonomer content in the xylene solubles of 43.6 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 1.84, and weight average molecular weight of 27.1 × 10 4The polypropylene copolymer powder had a molecular weight of 8.46 g / mol, a MFR of 8.46 g / 10 min under a 2.16 kg load at 230 °C, a Tm of 162.0 °C, a breakdown field strength of 261 kV / mm at 90 °C, and a DC volume resistivity of 9E12 Ω·m at 90 °C and 15 kV / mm. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above basic polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 7 g of lauroyl peroxide and 160 g of N-vinylcarbazole were dissolved in 500 g of surfactant toluene to form a solution, which was then added to the reactor. The reaction mixture was mixed with stirring for 30 minutes, heated to 95 °C, and 3 kg of dispersant water was added at 95 °C. The reaction was allowed to proceed for 3 hours. After the reaction was complete, the reaction product was cooled, filtered to remove the dispersant water, and vacuum dried at 70°C for 10 hours to obtain polypropylene-N-vinylcarbazole material product D6. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0238] Example 7D 2.0 kg of the base polypropylene copolymer powder from Example 1D was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and purged with nitrogen to remove oxygen. 4.5 g of dibenzoyl peroxide and 200 g of 4-vinylpyridine were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 50°C for 30 minutes, heated to 90°C, and reacted for 4 hours. After the reaction was complete, the reaction product was cooled with a nitrogen purge to obtain polypropylene-g-4-vinylpyridine material product D7. The resulting product was tested for various performance parameters. The results are shown in Table 4.

[0239] <Comparative Example 1D> After sieving to remove fine particles smaller than 40 mesh, 2.0 kg of T30S powder (breakdown field strength at 90 °C: 347 kV / mm, DC volume resistivity at 90 °C and 15 kV / mm: 1.18E13 Ω·m) was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 1.2 g of dibenzoyl peroxide and 40 g of 4-vinylpyridine were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 50 °C for 30 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-4-vinylpyridine material product CD1. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0240] <Comparative example 2D> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The molecular weight (MFR) was 1.21 g / mol under a 2.16 kg load at 230 °C, Tm = 143.4 °C, breakdown field strength at 90 °C was 236 kV / mm, and DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2.0 kg of the above base polypropylene copolymer powder was weighed and added to a 10 L reactor equipped with a mechanical stirrer. The reaction system was sealed and oxygen was removed by nitrogen substitution. 7.5 g of dibenzoyl peroxide and 300 g of 4-vinylpyridine were added, and the reaction mixture was mixed with stirring for 30 minutes, swelled at 50 °C for 30 minutes, heated to 90 °C, and reacted for 4 hours. After the reaction was completed, the reaction product was cooled by nitrogen purging to obtain polypropylene-g-4-vinylpyridine material product CD2. Various performance parameters of the resulting product were tested. The results are shown in Table 4.

[0241] <Comparative example 3D> A base polypropylene copolymer powder was selected with the following characteristics: comonomer ethylene content of 18.1 wt%, xylene solubles content of 48.7 wt%, comonomer content in the xylene solubles of 31.9 wt%, intrinsic viscosity ratio of xylene solubles to polypropylene copolymer of 0.89, and weight average molecular weight of 34.3 × 10 4 The molecular weight (MFR) was 1.21 g / mol at 230 °C under a 2.16 kg load, Tm was 143.4 °C, the breakdown field strength at 90 °C was 236 kV / mm, and the DC volume resistivity at 90 °C and 15 kV / mm was 1.16E13 Ω·m. Fine powder smaller than 40 mesh was removed by sieving. 2000 g of the above base polypropylene copolymer powder was weighed and mixed with 40 g of poly(4-vinylpyridine) in a screw extruder to obtain Blend CD3. The resulting product was tested for various performance parameters. The results are shown in Table 4.

[0242] [Table 2]

[0243] remarks: M1 indicates the content of structural units in the graft-modified polypropylene material that are derived from styrene monomers and are in a grafted state. The breakdown field strength change rate ΔE / E is the ratio of the breakdown field strength E of the aromatic olefin graft-modified polypropylene material product at 90°C to the breakdown field strength E of the base polypropylene copolymer powder at 90°C. g This refers to the ratio obtained by multiplying the difference ΔE between the breakdown field strength E of the base polypropylene copolymer powder at 90°C and that of the base polypropylene copolymer powder at 90°C by 100%. ρ vg refers to the DC volume resistivity of the aromatic olefin graft modified polypropylene material product at 90 °C and 15 kV / mm electric field strength, and ρ vg / ρ v is the DC volume resistivity ρ of the basic polypropylene copolymer powder at 90°C and 15 kV / mm electric field strength. vDC volume resistivity ρ of aromatic olefin graft modified polypropylene material product at 90℃ and 15kV / mm electric field strength vg Refers to the percentage of

[0244] [Table 3]

[0245] remarks: M1 indicates the content of structural units in the silane-modified polypropylene graft that are derived from alkenyl-containing silane monomers and remain grafted. The breakdown field strength change rate ΔE / E is the ratio of the breakdown field strength E of the silane-modified polypropylene graft product at 90°C to the breakdown field strength E of the base polypropylene copolymer powder at 90°C. g This refers to the ratio obtained by multiplying the difference ΔE between the breakdown field strength E of the base polypropylene copolymer powder at 90°C and that of the base polypropylene copolymer powder at 90°C by 100%. ρ vg refers to the DC volume resistivity of the silane-modified polypropylene graft product at 90°C and 15 kV / mm electric field strength, and ρ vg / ρ v is the DC volume resistivity ρ of the basic polypropylene copolymer powder at 90°C and an electric field strength of 15 kV / mm. v DC volume resistivity ρ of silane-modified polypropylene graft product at 90°C and 15 kV / mm electric field strength vg This refers to the ratio of

[0246] [Table 4]

[0247] remarks: M1 indicates the content of structural units in the graft-modified polypropylene material that are derived from acrylate monomers and optional acrylate monomers and are in a grafted state. The breakdown field strength change rate ΔE / E is the ratio of the breakdown field strength E of the graft-modified polypropylene material product at 90°C to the breakdown field strength E of the base polypropylene copolymer powder at 90°C. g This refers to the ratio obtained by multiplying the difference ΔE between the breakdown field strength E of the base polypropylene copolymer powder at 90°C and that of the base polypropylene copolymer powder at 90°C by 100%. ρ vg refers to the DC volume resistivity of the graft-modified polypropylene material product at 90°C and 15kV / mm electric field strength, and ρ vg / ρ v is the DC volume resistivity ρ of the basic polypropylene copolymer powder at 90°C and 15 kV / mm electric field strength. v DC volume resistivity ρ of the graft-modified polypropylene material product at 90°C and 15 kV / mm electric field strength vg Refers to the percentage of

[0248] [Table 5]

[0249] remarks: M1 indicates the content of structural units derived from alkenyl-containing heterocyclic monomers and in a grafted state in the heterocyclic graft-modified polypropylene material. The breakdown field strength change rate ΔE / E is the ratio of the breakdown field strength E of the heterocyclic graft-modified polypropylene material product at 90°C to the breakdown field strength E of the base polypropylene copolymer powder at 90°C. g This refers to the ratio obtained by multiplying the difference ΔE between the breakdown field strength E of the base polypropylene copolymer powder at 90°C and that of the base polypropylene copolymer powder at 90°C by 100%. ρ vg refers to the DC volume resistivity of the heterocyclic graft modified polypropylene material product at 90 °C and 15 kV / mm electric field strength, and ρ vg / ρ v is the DC volume resistivity ρ of the basic polypropylene copolymer powder at 90°C and 15 kV / mm electric field strength. vDC volume resistivity ρ of the heterocyclic graft modified polypropylene material product at 90°C and an electric field strength of 15 kV / mm, vg Refers to the percentage of

[0250] Comparing the data of Example 1A and Comparative Example 1A, it can be seen that using T30S powder as the base powder results in a polypropylene-g-styrene material product with too high a flexural modulus, poor mechanical properties, and inability to meet the processing requirements of insulation.

[0251] Comparing the data of Example 1A and Comparative Example 2A, it can be seen that the excessive addition of styrene monomer (too high an M value) results in a significant reduction in the elongation at break of the resulting polypropylene-g-styrene material product, affecting the mechanical properties of the material, and results in a reduction in the breakdown field strength and volume resistivity of the material, affecting the electrical properties of the material.

[0252] Comparing the data for Example 1A and Comparative Example 3A, it can be seen that the incorporation of polystyrene significantly affects the electrical properties of the material, resulting in a significant reduction in the breakdown field strength and volume resistivity of the material.

[0253] In conclusion, as can be seen from the data in Table 1, the aromatic olefin grafted polypropylene material of the present invention has good mechanical properties due to a significant reduction in flexural modulus, and the breakdown field strength of the grafted product is all improved compared to the ungrafted polypropylene copolymer using styrene monomer, and at the same time, the aromatic olefin grafted polypropylene material of the present invention has good electrical properties.

[0254] By comparing the data of Example 1B and Comparative Example 1B, it can be seen that using T30S powder as the base powder results in a polypropylene-g-silane material product with too high a flexural modulus and poor mechanical properties that cannot meet the processing requirements of insulating materials.

[0255] Comparing the data of Example 1B and Comparative Example 2B, it can be seen that excessive addition of alkenyl-containing silane monomer (too high M value) resulted in a decrease in the breakdown field strength and volume resistivity of the resulting polypropylene-g-silane material product, affecting the electrical properties of the product.

[0256] Comparing the data of Example 1B and Comparative Example 3B, it can be seen that the method of incorporating polyvinyltriethoxysilane results in a significant reduction in the breakdown field strength and volume resistivity of the product, significantly affecting the electrical properties of the product.

[0257] In conclusion, as can be seen from the data in Table 2, the silane-modified polypropylene grafts of the present invention have good mechanical properties with a significant reduction in flexural modulus, and the breakdown field strength of the grafted products are all improved compared to the ungrafted polypropylene copolymers using alkenyl-containing silane monomers, which also indicates that the silane-modified polypropylene grafts of the present invention have good electrical properties.

[0258] By comparing the data of Example 1C and Comparative Example 1C, it can be seen that using T30S powder as the base powder results in a polypropylene-g-acrylate material product with too high a flexural modulus and poor mechanical properties that cannot meet the processing requirements of insulating materials.

[0259] Comparing the data of Example 1C and Comparative Example 2C, it can be seen that excessive addition of acrylate monomer (too high M value) resulted in a decrease in the breakdown field strength and volume resistivity of the resulting polypropylene-g-acrylate material product, affecting the electrical properties of the product.

[0260] Comparing Example 1C and Comparative Example 3C, it can be seen that the method of incorporating the acrylate polymer significantly affects the electrical properties of the product, resulting in a significant reduction in the breakdown field strength and volume resistivity of the product.

[0261] In conclusion, as can be seen from the data in Table 3, the graft-modified polypropylene material of the present invention has good mechanical properties due to a significant reduction in flexural modulus, and the breakdown field strength of the grafted product is all improved compared to the ungrafted polypropylene copolymer using acrylate monomers and any acrylic monomers, which also indicates that the graft-modified polypropylene material of the present invention has good electrical properties.

[0262] By comparing the data of Example 1D and Comparative Example 1D, it can be seen that using T30S powder as the base powder results in a polypropylene-g-heterocyclic material product with too high a flexural modulus and poor mechanical properties that cannot meet the processing requirements of insulating materials.

[0263] By comparing the data of Example 1D and Comparative Example 2D, it can be seen that excessive addition of heterocyclic monomer (too high M value) results in a significant decrease in the breakdown field strength and volume resistivity of the resulting polypropylene-g-heterocyclic material product, affecting the electrical properties of the product.

[0264] By comparing the data of Example 1D and Comparative Example 3D, it can be seen that the method of incorporating heterocyclic polymers significantly reduces the breakdown field strength and volume resistivity of the product, thereby significantly affecting the electrical properties of the product.

[0265] In conclusion, as can be seen from the data in Table 4, the heterocyclic graft-modified polypropylene material of the present invention has good mechanical properties due to a significant reduction in flexural modulus, and the breakdown field strength of the grafted product is all improved compared to the ungrafted polypropylene copolymer using heterocyclic monomers, which also indicates that the heterocyclic graft-modified polypropylene material of the present invention has good electrical properties.

[0266] Furthermore, as can be seen from the dielectric constant and dielectric loss data, the graft modification does not affect the dielectric constant and dielectric loss of the material, and the material of the present invention meets the requirements for an insulating material. vinegar.

[0267] <Example A0> Conductor preparation: A large number of aluminum monofilament conductors are wired and processed into bundles, and then each bundled monofilament conductor is twisted to obtain an aluminum conductor inner core.

[0268] Preparation of aromatic olefin-modified polypropylene particles: 100 parts by mass of the aromatic olefin-modified polypropylene materials obtained in Examples A1, A3, A5, A7, and A8 were blended with 0.3 parts by mass of antioxidant 1010 / 168 / calcium stearate (mass ratio: 2:2:1), and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0269] Preparation of the conductor shielding layer and electrical insulation layer: Conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the aromatic olefin-modified polypropylene particles were coextruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 160-220°C.

[0270] Preparation of metal shielding layer: Using T1 copper, a copper strip is wound around the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0271] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0272] Sheath Preparation: Prepare a 1.25 mm nominal diameter steel wire sheath using 304 stainless steel, and wrap the single-layer sheath around the inner sheath layer in a counterclockwise direction to ensure a tight sheath and minimize gaps between adjacent steel wires.

[0273] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0274] Finally, a cable with a thermoplastic insulation layer was obtained, the cross section of which is shown in Figure 1.

[0275] According to the above method, cables having an energy level in the range of 6 to 35 kV were prepared based on the materials of Examples A1, A3, A5, A7, and A8, respectively. The cross-sectional area of ​​the conductor in the cable was 240 to 400 mm 2 The thickness of the conductor shielding layer was 1 to 3 mm, the thickness of the electrical insulating layer was 2 to 8 mm, the thickness of the electrical insulating shielding layer was 0.5 to 1.5 mm, the thickness of the outer sheath was 0.5 to 1 mm, the thickness of the inner sheath layer was 1 to 2 mm, and the thickness of the outer sheath layer was 1.8 mm or more.

[0276] <Test Example A0> The prepared cables were tested. Results of the cable main insulation conductivity test: The conductivity ratio of each cable at 90°C and 30°C was less than 100. Results of the insulation space charge injection test of each cable: The electric field distortion rate of each cable was less than 20%. Results of the DC withstand voltage test: Each cable had no breakdown or discharge phenomena and passed the test. Results of the load cycle test: Each cable had no breakdown phenomena and passed the test.

[0277] <Example B0> Conductor preparation: A large number of aluminum monofilament conductors are wired and processed into bundles, and then each bundled monofilament conductor is twisted to obtain an inner core of the aluminum conductor.

[0278] Preparation of alkenyl-containing silane-modified polypropylene particles: 100 parts by mass of the alkenyl-containing silane-modified polypropylene material obtained in Examples B1 to B4 and Examples B6 to B7 and 0.3 parts by mass of antioxidant 1010 / 168 / calcium stearate (mass ratio: 2:2:1) were blended and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0279] Preparation of the conductor shielding layer and electrical insulation layer: The conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the above-mentioned alkenyl-containing silane-modified polypropylene particles were co-extruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 160-220°C.

[0280] Preparation of metal shielding layer: Using T1 copper, a copper strip is wound around the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0281] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0282] Sheath Preparation: Prepare a 1.25 mm nominal diameter steel wire sheath using 304 stainless steel, and wrap the single layer sheath counterclockwise around the inner sheath layer to ensure a tight seal and minimize gaps between adjacent steel wires.

[0283] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0284] Finally, a cable with a modified polypropylene thermoplastic insulation layer was obtained, the cross section of which is shown in Figure 1.

[0285] According to the above method, cables having an energy level in the range of 6 to 35 kV were prepared based on the materials of Examples B1 to B4 and Examples B6 to B7, respectively, and the cross-sectional area of ​​the conductor in the cables was 240 to 400 mm 2 The thickness of the conductor shielding layer was 1 to 3 mm, the thickness of the electrical insulating layer was 2 to 8 mm, the thickness of the electrical insulating shielding layer was 0.5 to 1.5 mm, the thickness of the outer sheath was 0.5 to 1 mm, the thickness of the inner sheath layer was 1 to 2 mm, and the thickness of the outer sheath layer was 1.8 mm or more.

[0286] <Test Example B0> The prepared cables were tested. Results of the cable main insulation conductivity test: The conductivity ratio of each cable at 90°C and 30°C was less than 100. Results of the insulation space charge injection test of each cable: The electric field distortion rate of each cable was less than 20%. Results of the DC withstand voltage test: Each cable did not experience any breakdown or discharge phenomena and passed the test. Results of the load cycle test: Each cable did not experience any breakdown phenomena and passed the test.

[0287] <Example C0> Conductor preparation: A large number of aluminum monofilament conductor wiring bundles are processed, and then each bundled monofilament conductor is twisted to obtain an inner core of the aluminum conductor.

[0288] Preparation of acrylate-modified polypropylene particles: 100 parts by mass of the acrylate-modified polypropylene materials obtained in Examples C1, C3, C5, C7, and C8, 0.3 parts by mass of antioxidant 1010 / 168 / calcium stearate (mass ratio: 2:2:1), and 0.05 parts by mass of copper inhibitor MDA-5 were blended and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0289] Preparation of the conductor shielding layer and electrical insulation layer: Conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) was coextrusion coated with the above acrylate-modified polypropylene particles in an extruder to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an outer electrical insulation shielding layer. The extrusion temperature was 160-220°C.

[0290] Preparation of metal shielding layer: Using T1 copper, a copper strip is wound around the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0291] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0292] Sheath Preparation: A 1.25 mm nominal diameter steel wire sheath is prepared using 304 stainless steel, and the single layer sheath is wound around the inner sheath layer so that the sheath is sealed and the gaps between adjacent steel wires are minimized.

[0293] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0294] Finally, a cable with a modified polypropylene insulation layer was obtained, the cross section of which is shown in Figure 1.

[0295] According to the above method, cables having an energy level ranging from 6 to 35 kV were prepared based on the materials of Examples C1, C3, C5, C7, and C8, respectively, and the cross-sectional area of ​​the conductor in the cables was 240 to 400 mm 2The thickness of the conductor shielding layer was 1 to 3 mm, the thickness of the electrical insulating layer was 2 to 8 mm, the thickness of the electrical insulating shielding layer was 0.5 to 1.5 mm, the thickness of the outer sheath was 0.5 to 1 mm, the thickness of the inner sheath layer was 1 to 2 mm, and the thickness of the outer sheath layer was 1.8 mm or more.

[0296] <Test example C0> The prepared cables were tested. Results of the cable main insulation conductivity test: The conductivity ratio of each cable at 90°C and 30°C was less than 100. Results of the insulation space charge injection test of each cable: The electric field distortion rate of each cable was less than 20%. Results of the DC withstand voltage test: Each cable did not experience any breakdown or discharge phenomena and passed the test. Results of the load cycle test: Each cable did not experience any breakdown phenomena and passed the test.

[0297] <Example D0> Conductor preparation: A large number of aluminum monofilament conductors are wired and processed into bundles, and then each bundled monofilament conductor is twisted to obtain an inner core of the aluminum conductor.

[0298] Preparation of heterocyclic graft-modified polypropylene material particles: 100 parts by mass of the heterocyclic graft-modified polypropylene material obtained in Example D2, Example D3, Example D5, and Example D7 were blended with 0.3 parts by mass of antioxidant 1010 / 168 / calcium stearate (mass ratio: 2:2:1), and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0299] Preparation of the conductor shielding layer and electrical insulation layer: Conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the above-mentioned heterocyclic graft-modified polypropylene particles were co-extruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 160-210°C.

[0300] Preparation of metal shielding layer: Using T1 copper, a copper strip is wound around the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0301] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0302] Sheath Preparation: Prepare a 1.25 mm nominal diameter steel wire sheath using 304 stainless steel, and wrap the single layer sheath counterclockwise around the inner sheath layer to ensure a sealed sheath and minimize gaps between adjacent steel wires.

[0303] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0304] The final result was a cable with a high-performance polypropylene thermoplastic insulation layer, the cross section of which is shown in Figure 1.

[0305] According to the above method, cables having an energy level in the range of 6 to 35 kV were prepared based on the materials of Examples D2, D3, D5, and D7, respectively. The cross-sectional area of ​​the conductor in the cable was 240 to 400 mm 2 The thickness of the conductor shielding layer was 1 to 3 mm, the thickness of the electrical insulating layer was 2 to 8 mm, the thickness of the electrical insulating shielding layer was 0.5 to 1.5 mm, the thickness of the outer sheath was 0.5 to 1 mm, the thickness of the inner sheath layer was 1 to 2 mm, and the thickness of the outer sheath layer was 1.8 mm or more.

[0306] <Test example D0> The prepared cables were tested. Results of the cable main insulation conductivity test: The conductivity ratio of each cable at 90°C and 30°C was less than 100. Results of the insulation space charge injection test of each cable: The electric field distortion rate of each cable was less than 20%. Results of the DC withstand voltage test: Each cable did not experience any breakdown or discharge phenomena and passed the test. Results of the load cycle test: Each cable did not experience any breakdown phenomena and passed the test.

[0307] Example A Preparation of conductor: 76 aluminum monofilaments with a diameter of 2.5 mm were compacted and twisted to obtain the inner core of the aluminum conductor.

[0308] Preparation of aromatic olefin-modified polypropylene particles: 100 parts by mass of the aromatic olefin-modified polypropylene material obtained in Example 2A and 0.3 parts by mass of antioxidant 1010 / 168 / calcium stearate (mass ratio: 2:2:1) were blended and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0309] Preparation of the conductor shielding layer and electrical insulation layer: Conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the aromatic olefin-modified polypropylene particles were co-extruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 190-220°C.

[0310] Preparation of metal shielding layer: Using 25 pieces of T1 copper wire with a diameter of 0.3 mm, wind the copper wire on the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0311] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0312] Sheath preparation: Prepare the steel wire sheath using 50 pieces of 6.0 mm diameter 304 stainless steel wire, and wrap the single-layer sheath around the inner sheath layer in a left-handed direction so that the sheath is sealed and the gaps between adjacent steel wires are minimized.

[0313] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0314] Finally, a cable with a thermoplastic insulation layer was obtained, the cross section of which is shown in Figure 1.

[0315] According to the above method, a cable with an energy level of 10 kV was prepared based on the material of Example 2A. The cross-sectional area of ​​the conductor in the cable was 400 mm 2 The average thickness of the conductor shielding layer was 1.04 mm, the average thickness of the electrical insulation layer was 2.53 mm, the average thickness of the electrical insulation shielding layer was 1.05 mm, the average thickness of the metallic shielding layer was 0.92 mm, the cable insulation eccentricity was 5.1%, the average thickness of the outer sheath was 6.00 mm, the average thickness of the inner sheath layer was 1.80 mm, and the average thickness of the outer sheath layer was 2.45 mm.

[0316] <Test Example A> The prepared cable was tested. Result of cable main insulation conductivity test: The conductivity of the cable at 90°C and 30°C was 47.5. Result of cable insulation space charge injection test: The electric field distortion factor of the cable was 18.3%. Result of DC withstand voltage test: The cable had no breakdown or discharge phenomena and passed the test. Result of load cycle test: The cable had no breakdown phenomena and passed the test.

[0317] Example B Preparation of conductor: 76 aluminum monofilaments with a diameter of 2.5 mm were compacted and twisted to obtain the inner core of the aluminum conductor.

[0318] Preparation of alkenyl-containing silane-modified polypropylene particles: 100 parts by mass of the alkenyl-containing silane-modified polypropylene material obtained in Example 5B and 0.3 parts by mass of antioxidant 1010 / 168 / calcium stearate (mass ratio: 2:2:1) were blended and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0319] Preparation of the conductor shielding layer and electrical insulation layer: The conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the above-mentioned alkenyl-containing silane-modified polypropylene particles were co-extruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 190-220°C.

[0320] Preparation of metal shielding layer: Using 25 pieces of T1 copper wire with a diameter of 0.3 mm, wind the copper wire on the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0321] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0322] Sheath preparation: Prepare the steel wire sheath using 50 pieces of 6.0 mm diameter 304 stainless steel wire, and wrap the single-layer sheath around the inner sheath layer in a left-handed direction so that the sheath is sealed and the gaps between adjacent steel wires are minimized.

[0323] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0324] Finally, a cable with a modified polypropylene thermoplastic insulation layer was obtained, the cross section of which is shown in Figure 1.

[0325] According to the above method, a cable with an energy level of 10 kV was prepared based on the material of Example 5B. The cross-sectional area of ​​the conductor in the cable was 400 mm 2 The average thickness of the conductor shielding layer was 1.05 mm, the average thickness of the electrical insulation layer was 2.95 mm, the average thickness of the electrical insulation shielding layer was 1.18 mm, the average thickness of the metallic shielding layer was 0.95 mm, the cable insulation eccentricity was 5.2%, the average thickness of the outer sheath was 5.95 mm, the average thickness of the inner sheath layer was 2.44 mm, and the average thickness of the outer sheath layer was 2.80 mm.

[0326] <Test Example B> The prepared cable was tested. Result of cable main insulation conductivity test: The conductivity of the cable at 90°C and 30°C was 56.8. Result of cable insulation space charge injection test: The electric field distortion factor of the cable was 17.5%. Result of DC withstand voltage test: The cable had no breakdown or discharge phenomenon and passed the test. Result of load cycle test: The cable had no breakdown phenomenon and passed the test.

[0327] Example C Conductor preparation: 76 copper monofilaments with a diameter of 2.5 mm are compacted and twisted to obtain a copper conductor core.

[0328] Preparation of acrylate-modified polypropylene particles: 100 parts by mass of the modified polypropylene material obtained in Example 2C and 0.3 parts by mass of antioxidant 1024 are blended and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0329] Preparation of the conductor shielding layer and electrical insulation layer: The conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the modified polypropylene particles were co-extruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 190-220°C.

[0330] Preparation of metal shielding layer: Using 25 pieces of T1 copper wire with a diameter of 0.3 mm, wind the copper wire on the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0331] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0332] Sheath preparation: Prepare the steel wire sheath using 50 pieces of 6.0 mm diameter 304 stainless steel wire, and wrap the single-layer sheath around the inner sheath layer in a left-handed direction so that the sheath is sealed and the gaps between adjacent steel wires are minimized.

[0333] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0334] Finally, a cable with a modified polypropylene insulation layer was obtained, the cross section of which is shown in Figure 1.

[0335] According to the above method, a cable with an energy level of 10 kV was prepared based on the material of Example 2C. The cross-sectional area of ​​the conductor in the cable was 400 mm 2 The average thickness of the conductor shielding layer was 1.19 mm, the average thickness of the electrical insulation layer was 2.96 mm, the average thickness of the electrical insulation shielding layer was 1.06 mm, the average thickness of the metallic shielding layer was 0.94 mm, the cable insulation eccentricity was 4.9%, the average thickness of the outer sheath was 5.93 mm, the average thickness of the inner sheath layer was 2.07 mm, and the average thickness of the outer sheath layer was 2.75 mm.

[0336] <Test Example C> The prepared cable was tested. Result of cable main insulation conductivity test: The conductivity of the cable at 90°C and 30°C was 69.4. Result of cable insulation space charge injection test: The electric field distortion factor of the cable was 18.6%. Result of DC withstand voltage test: The cable had no breakdown or discharge phenomenon and passed the test. Result of load cycle test: The cable had no breakdown phenomenon and passed the test.

[0337] Example D Preparation of conductor: 76 aluminum monofilaments with a diameter of 2.5 mm were compacted and twisted to obtain the inner core of the aluminum conductor.

[0338] Preparation of heterocyclic graft-modified polypropylene material particles: 100 parts by mass of the heterocyclic graft-modified polypropylene material obtained in Example 1D and 0.3 parts by mass of antioxidant 1035 are blended and granulated in a twin-screw extruder at a rotation speed of 300 r / min and a granulation temperature of 210 to 230°C.

[0339] Preparation of the conductor shielding layer and electrical insulation layer: The conductor shielding material PSD_WMP-00012 (Zhejiang Wanma Co., Ltd.) and the above-mentioned heterocyclic graft-modified polypropylene particles were co-extruded onto the outer surface of the conductor core to form either a conductor shielding layer plus an electrical insulation layer, or a conductor shielding layer plus an electrical insulation layer plus an electrical insulation shielding layer (outer shielding layer). The extrusion temperature was 190-210°C.

[0340] Preparation of metal shielding layer: Using 25 pieces of T1 copper wire with a diameter of 0.3 mm, wind the copper wire on the outside of the electrical insulation layer (electrical insulation shielding layer) to form a metal shielding layer.

[0341] Preparation of the inner sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the metal shielding layer using an extruder to form the inner sheath layer.

[0342] Sheath preparation: Prepare the steel wire sheath using 50 pieces of 6.0 mm diameter 304 stainless steel wire, and wrap the single-layer sheath around the inner sheath layer in a counterclockwise direction to ensure that the sheath is sealed and the gaps between adjacent steel wires are minimized.

[0343] Preparation of outer sheath layer: St-2 PVC granules (Dongguan Haichuang Electronics Co., Ltd.) are extruded onto the outside of the outer sheath using an extruder to form the outer sheath layer.

[0344] The final result was a cable with a high-performance polypropylene insulation layer, the cross section of which is shown in Figure 1.

[0345] According to the above method, a cable with an energy level of 10 kV was prepared based on the material of Example 1D. The cross-sectional area of ​​the conductor in the cable was 400 mm 2 The average thickness of the conductor shielding layer was 1.07 mm, the average thickness of the electrical insulating layer was 2.64 mm, the average thickness of the electrical insulating shielding layer was 1.00 mm, the average thickness of the metallic shielding layer was 1.00 mm, the cable insulation eccentricity was 5.4%, the average thickness of the outer sheath was 5.94 mm, the average thickness of the inner sheath layer was 2.25 mm, and the average thickness of the outer sheath layer was 2.40 mm.

[0346] <Test Example D> The prepared cable was tested. Result of cable main insulation conductivity test: The conductivity of the cable at 90°C and 30°C was 52.1. Result of cable insulation space charge injection test: The electric field distortion factor of the cable was 16.2%. Result of DC withstand voltage test: The cable had no breakdown or discharge phenomenon and passed the test. Result of load cycle test: The cable had no breakdown phenomenon and passed the test.

[0347] It can be seen that a cable comprising the graft-modified polypropylene material of the present invention as the main insulation layer has a higher service temperature than a conventional cable, and can even have a higher volume resistivity and stronger puncture resistance at higher service temperatures, while still maintaining a higher volume resistivity and stronger puncture resistance. Under conditions ensuring the same voltage grade and insulation level, compared to the electrical insulation layer of a conventional cable, the electrical insulation layer made from the graft-modified polypropylene material has the advantages of being thinner, having better heat dissipation, and being lighter in weight.

[0348] Although the embodiments of the present invention have been described above, the above description is illustrative and not exhaustive, and the present invention is not limited to the embodiments. Many improvements and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the embodiments.

[0349] The endpoints of the ranges and any values ​​disclosed herein should be understood not to be limited to the exact range or value, but to encompass values ​​close to those ranges or values. For numerical ranges, the endpoints of the ranges, the endpoints of the ranges and individual point values, and the individual point values ​​can be combined with each other to create one or more new numerical ranges, which should be considered to be specifically disclosed herein. [Brief explanation of the drawings]

[0350] [Figure 1] FIG. 1 is a schematic cross-sectional view of a cable according to one embodiment of the present invention.

Claims

1. A graft-modified polypropylene material for insulating materials, comprising: It contains structural units derived from a polypropylene copolymer and structural units derived from an alkenyl-containing polymerizable monomer, the content of grafted structural units derived from the alkenyl-containing polymerizable monomer in the graft-modified polypropylene material is 0.1 to 6.04 wt % based on the weight of the graft-modified polypropylene material; The polypropylene copolymer is a graft-modified polypropylene material having at least one of the following characteristics: The comonomer content is 0.5 to 40 mol%; The content of xylene solubles is 2 to 80% by weight; The content of the comonomer in the xylene soluble matter is 10 to 70% by weight; the ratio of the intrinsic viscosity of the xylene soluble material to the polypropylene copolymer is 0.3 to 5; The alkenyl-containing polymerizable monomer is at least one selected from monomers having a structure represented by Formula 1, 【Chemistry 1】 In formula 1, R ｂ , R ｃ , R ｄ are each independently H, substituted or unsubstituted C １ -C ６ alkyl; R ａ is selected from a group represented by formula 2, a group represented by formula 3, a group represented by formula 4, a group represented by formula 5, a group represented by formula 6, a combination of a group represented by formula 6 and a group represented by formula 7, and a heterocyclic group: 【Chemistry 2】 In formula 2, R ４ -R ８ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups ； 【Transformation 3】 In formula 3, R ４ -R １０ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Chemistry 4】 In formula 4, R ４ '-R １０ Each ' is independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Transformation 5】 In formula 5, R', R'', and R''' are each independently substituted or unsubstituted C １ -C １２ Straight chain alkyl, substituted or unsubstituted C ３ -C １２ Branched alkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ acyloxy; 【Transformation 6】 【Transformation 7】 In formula 6, R ｍ is substituted or unsubstituted, C １ -C ２０ Straight chain alkyl, C ３ -C ２０ Branched alkyl, C ３ -C １２ Cycloalkyl, C ３ -C １２ Epoxy alkyl, C ３ -C １２ epoxyalkylalkyl, the substituents of which are at least one selected from halogen, amino and hydroxy; The heterocyclic group is selected from imidazolyl, pyrazolyl, carbazolyl, pyrrolidinonyl, pyridyl, piperidinyl, caprolactam group, pyrazinyl, thiazolyl, purinyl, morpholinyl, oxazolinyl.

2. 2. The graft-modified polypropylene material according to claim 1, wherein the content of structural units derived from the alkenyl-containing polymerizable monomer and in a grafted state in the graft-modified polypropylene material is 0.2 to 6 wt %, or 0.8 to 5 wt %, or 0.5 to 6 wt %, based on the weight of the graft-modified polypropylene material.

3. 3. The graft-modified polypropylene material of claim 1 or 2, wherein the polypropylene copolymer has at least one of the following characteristics: the comonomer content is 0.5 to 30 mol%, or 4 to 25 wt%, or 4 to 22 wt%; the xylene solubles content is 18 to 75 wt%, or 30 to 70 wt%, or 30 to 67 wt%; the content of the comonomer in the xylene soluble matter is 10 to 50% by weight, or 20 to 35% by weight; The ratio of the intrinsic viscosity of the xylene solubles to the polypropylene copolymer is 0.5 to 3, or 0.8 to 1.

3.

4. The graft-modified polypropylene material according to any one of claims 1 to 3, wherein the polypropylene copolymer has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 60 g / 10 min, or 0.05 to 35 g / 10 min, or 0.5 to 15 g / 10 min; a melting point Tm of 100°C or higher, or 110 to 180°C, or 110 to 170°C, or 120°C or higher, or 120 to 170°C, or 120 to 166°C; Weight average molecular weight is 20 x 10 ４ ~60 x 10 ４ g / mol.

5. The comonomer of the polypropylene copolymer is a C copolymer other than propylene. ２ -C ８ The graft-modified polypropylene material according to any one of claims 1 to 4, wherein the α-olefin is at least one selected from the following α-olefins:

6. The graft-modified polypropylene material according to any one of claims 1 to 5, wherein the comonomer of the polypropylene copolymer is at least one selected from ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene.

7. The graft-modified polypropylene material of any one of claims 1 to 6, prepared by a solid-state graft reaction of a polypropylene copolymer and an alkenyl-containing polymerizable monomer.

8. The graft-modified polypropylene material according to any one of claims 1 to 7, having at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, or 0.05 to 20 g / 10 min, or 0.1 to 10 g / 10 min, or 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, or 20 to 1000 MPa, or 50 to 600 MPa; The elongation at break is 200% or more, or 300% or more.

9. The graft-modified polypropylene material according to any one of claims 1 to 8, having at least one of the following characteristics: The use temperature of the graft-modified polypropylene material is 90°C or higher, or 90 to 160°C; The breakdown field strength E of the graft-modified polypropylene material at 90 ° C. ｇ is 180 kV / mm or more, or 180 to 800 kV / mm; The breakdown field strength E of the graft-modified polypropylene material at 90 ° C. ｇ and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E exceeds 0.7%, or is 0.8 to 50%, or 2 to 35%, or 5 to 25%; The direct current volume resistivity ρ of the graft-modified polypropylene material at 90 ° C and 15 kV / mm electric field strength ｖｇ is 6 x 10 １２ Ω.m or more, or 6 x 10 １２ Ω.m ~ 1.0 x 10 ２０ Ω.m; The direct current volume resistivity ρ of the polypropylene copolymer at 90°C and an electric field strength of 15 kV / mm ｖ , the direct current volume resistivity ρ of the graft-modified polypropylene material at 90 ° C and 15 kV / mm electric field strength ｖｇ The ratio (ρ ｖｇ / ρ ｖ ) is greater than 1, or 1.1 to 50, or 1.15 to 20, or 1.2 to 10.

10. In formula 2, R ４ -R ８ are each independently H, halogen, hydroxy, amino, substituted or unsubstituted C １ -C ６ Alkyl, substituted or unsubstituted C １ -C ６ alkoxy; and / or In formula 3, R ４ -R １０ are each independently H, halogen, hydroxy, amino, substituted or unsubstituted C １ -C ６ Alkyl, substituted or unsubstituted C １ -C ６ alkoxy, the substituents of which are halogen, hydroxy, amino, C １ -C ６ Alkyl, C １ -C ６ alkoxy; and / or In formula 4, R ４ '-R １０ Each ' is independently H, halogen, hydroxy, amino, substituted or unsubstituted C １ -C ６ Alkyl, substituted or unsubstituted C １ -C ６ alkoxy, the substituents of which are halogen, hydroxy, amino, C １ -C ６ Alkyl, C １ -C ６ alkoxy; and / or In Formula 5, R′, R″, and R′″ are each independently substituted or unsubstituted C １ -C ６ Straight chain alkyl, substituted or unsubstituted C ３ -C ６ Branched alkyl, substituted or unsubstituted C １ -C ６ Alkoxy, substituted or unsubstituted C １ -C ６ 2. The graft-modified polypropylene material of claim 1, wherein the graft-modified polypropylene material is selected from acyloxy.

11. 1. A graft-modified polypropylene material comprising: It contains structural units derived from a polypropylene copolymer and structural units derived from an alkenyl-containing polymerizable monomer, the graft-modified polypropylene material is an aromatic olefin graft-modified polypropylene material; the alkenyl-containing polymerizable monomer is a styrene monomer; the content of the structural units derived from the styrene monomer and in a grafted state in the aromatic olefin graft-modified polypropylene material is 0.5 to 14 wt % relative to the weight of the aromatic olefin graft-modified polypropylene material; The polypropylene copolymer is a graft-modified polypropylene material having at least one of the following characteristics: The comonomer content is 0.5 to 40 mol%; The content of xylene solubles is 2 to 80% by weight; The content of the comonomer in the xylene soluble matter is 10 to 70% by weight; The ratio of the intrinsic viscosity of the xylene soluble material to the polypropylene copolymer is 0.3 to 5.

12. 12. The graft-modified polypropylene material according to claim 11, wherein the content of structural units derived from the styrene monomer and in a grafted state in the aromatic olefin-grafted polypropylene material is 1 to 7.5 wt %, or 1.5 to 5 wt %, based on the weight of the aromatic olefin-grafted polypropylene material.

13. the styrene monomer is at least one selected from a monomer having a structure represented by formula 8, a monomer having a structure represented by formula 9, and a monomer having a structure represented by formula 10; 【Transformation 8】 In formula 8, R １ , R ２ , R ３ are each independently H, substituted or unsubstituted C １ -C ６ alkyl; R ４ -R ８ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Chemistry 9】 In formula 9, R １ , R ２ , R ３ are each independently H, substituted or unsubstituted C １ -C ６ alkyl; R ４ -R １０ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Chemistry 10】 In formula 10, R １ ', R ２ ', R ３ Each ' is independently H, substituted or unsubstituted C １ -C ６ alkyl; R ４ '-R １０ Each ' is independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ 13. The graft-modified polypropylene material according to claim 11 or 12, wherein the graft-modified polypropylene group is selected from amine groups.

14. In formula 8, R １ , R ２ , R ３ are each independently H, substituted or unsubstituted C １ -C ３ alkyl, and R ４ -R ８ are each independently H, halogen, hydroxy, amino, substituted or unsubstituted C １ -C ６ Alkyl, substituted or unsubstituted C １ -C ６ alkoxy; and / or In formula 9, R １ , R ２ , R ３ are each independently H, substituted or unsubstituted C １ -C ３ alkyl, and R ４ -R １０ are each independently H, halogen, hydroxy, amino, substituted or unsubstituted C １ -C ６ Alkyl, substituted or unsubstituted C １ -C ６ alkoxy, the substituents of which are selected from halogen, hydroxy, amino, C １ -C ６ Alkyl, C １ -C ６ alkoxy; and / or In formula 10, R １ ', R ２ ', R ３ Each ' is independently H, substituted or unsubstituted C １ -C ３ alkyl, and R ４ '-R １０ Each ' is independently H, halogen, hydroxy, amino, substituted or unsubstituted C １ -C ６ Alkyl, substituted or unsubstituted C １ -C ６ alkoxy, the substituents of which are selected from halogen, hydroxy, amino, C １ -C ６ Alkyl, C １ -C ６ 14. The graft-modified polypropylene material of claim 13, wherein the graft-modified polypropylene material is selected from alkoxy.

15. The styrene monomer is at least one selected from styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, mono- or poly-substituted styrene, mono- or poly-substituted α-methylstyrene, mono- or poly-substituted 1-vinylnaphthalene, and mono- or poly-substituted 2-vinylnaphthalene; and the substituent is halogen, hydroxy, amino, a phosphoric acid group, a sulfonic acid group, C １ -C ８ Straight chain alkyl, C ３ -C ８ Branched alkyl or cycloalkyl, C １ -C ６ Linear alkoxy, C ３ -C ８ Branched alkoxy or cycloalkoxy, C １ -C ８ Linear ester group, C ３ -C ８ a branched ester group or a cyclic ester group, C １ -C ８ a linear amine group, and ３ -C ８ 14. The graft-modified polypropylene material of claim 13, wherein the amine group is at least one selected from a branched amine group or a cyclic amine group.

16. The graft-modified polypropylene material according to any one of claims 11 to 15, wherein the aromatic olefin graft-modified polypropylene material has at least one of the following characteristics: a melt flow rate under a load of 2.16 kg at 230°C of 0.01 to 30 g / 10 min, or 0.05 to 20 g / 10 min, or 0.1 to 10 g / 10 min, or 0.2 to 8 g / 10 min; a flexural modulus of 10 to 1250 MPa, or 20 to 1000 MPa, or 50 to 600 MPa; The elongation at break is 200% or more, or 300% or more.

17. The graft-modified polypropylene material according to any one of claims 11 to 15, wherein the aromatic olefin graft-modified polypropylene material has at least one of the following characteristics: The use temperature of the aromatic olefin grafted modified polypropylene material is 90°C or higher, or 90 to 160°C; The breakdown field strength E of the aromatic olefin graft modified polypropylene material at 90 ° C. ｇ is 200 kV / mm or more, or 200 to 800 kV / mm; The breakdown field strength E of the aromatic olefin graft modified polypropylene material at 90 ° C. ｇ and the breakdown field strength E of the polypropylene copolymer at 90°C, divided by the breakdown field strength E of the polypropylene copolymer at 90°C, the rate of change in breakdown field strength ΔE / E is greater than 1.5%, or 1.6 to 40%, or 5 to 30%, or 10 to 20%; The direct current volume resistivity ρ of the aromatic olefin grafted modified polypropylene material at 90 ° C and 15 kV / mm electric field strength ｖｇ is 1.0 x 10 １３ Ω.m or more, or 1.5 x 10 １３ Ω.m ~ 1.0 x 10 ２０ Ω.m; The direct current volume resistivity ρ of the aromatic olefin grafted modified polypropylene material at 90 ° C and 15 kV / mm electric field strength ｖ , the direct current volume resistivity ρ of the graft-modified polypropylene material at 90 ° C and 15 kV / mm electric field strength ｖｇ The ratio (ρ ｖｇ / ρ ｖ ) is greater than 1, or 1.5 to 50, or 2 to 20, or 3 to 10.

18. A method for preparing a graft-modified polypropylene material for insulating materials, comprising: grafting a reaction mixture comprising a polypropylene copolymer and an alkenyl-containing polymerizable monomer in the presence of an inert gas to obtain the graft-modified polypropylene material; The grafting reaction conditions are as follows: the content of grafted structural units derived from the alkenyl-containing polymerizable monomer in the graft-modified polypropylene material is 0.1 to 6.04 wt %, based on the weight of the graft-modified polypropylene material; The polypropylene copolymer has at least one of the following characteristics: The comonomer content is 0.5 to 40 mol%; The content of xylene solubles is 2 to 80% by weight; The content of the comonomer in the xylene soluble matter is 10 to 70% by weight; the ratio of the intrinsic viscosity of the xylene soluble material to the polypropylene copolymer is 0.3 to 5; The alkenyl-containing polymerizable monomer is at least one selected from monomers having a structure represented by Formula 1, 【Chemistry 11】 In formula 1, R ｂ , R ｃ , R ｄ are each independently H, substituted or unsubstituted C １ -C ６ alkyl; R ａ is selected from a group represented by formula 2, a group represented by formula 3, a group represented by formula 4, a group represented by formula 5, a group represented by formula 6, a combination of a group represented by formula 6 and a group represented by formula 7, and a heterocyclic group: 【Chemistry 12】 In formula 2, R ４ -R ８ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups ； 【Chemistry 13】 In formula 3, R ４ -R １０ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Chemistry 14】 In formula 4, R ４ '-R １０ Each ' is independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Chemistry 15】 In formula 5, R', R'', and R''' are each independently substituted or unsubstituted C １ -C １２ Straight chain alkyl, substituted or unsubstituted C ３ -C １２ Branched alkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ acyloxy; 【Chemistry 16】 【Chemistry 17】 In formula 6, R ｍ is substituted or unsubstituted, C １ -C ２０ Straight chain alkyl, C ３ -C ２０ Branched alkyl, C ３ -C １２ Cycloalkyl, C ３ -C １２ Epoxy alkyl, C ３ -C １２ epoxyalkylalkyl, the substituents of which are at least one selected from halogen, amino and hydroxy; The heterocyclic group is selected from imidazolyl, pyrazolyl, carbazolyl, pyrrolidinonyl, pyridyl, piperidinyl, caprolactam group, pyrazinyl, thiazolyl, purinyl, morpholinyl, oxazolinyl.

19. 19. The method of claim 18, wherein the grafting reaction conditions are: The content of grafted structural units derived from the alkenyl-containing polymerizable monomer in the graft-modified polypropylene material is 0.2 to 6 wt %, or 0.8 to 5 wt %, or 0.5 to 6 wt %, based on the weight of the graft-modified polypropylene material.

20. The polypropylene copolymer has at least one of the following characteristics: the comonomer content is 0.5 to 30 mol%, or 4 to 25 wt%, or 4 to 22 wt%; the xylene solubles content is 18 to 75 wt%, or 30 to 70 wt%, or 30 to 67 wt%; the content of the comonomer in the xylene soluble matter is 10 to 50% by weight, or 20 to 35% by weight; 20. The method of claim 18 or 19, wherein the ratio of intrinsic viscosity of the xylene solubles to the polypropylene copolymer is from 0.5 to 3, or from 0.8 to 1.

3.

21. The method of any one of claims 18 to 20, wherein the polypropylene copolymer has at least one of the following characteristics: a flow rate under a load of 2.16 kg at 230°C of 0.01 to 60 g / 10 min, or 0.05 to 35 g / 10 min, or 0.5 to 15 g / 10 min; a melting point Tm of 100°C or higher, or 110 to 180°C, or 110 to 170°C, or 120°C or higher, or 120 to 170°C, or 120 to 166°C; Weight average molecular weight is 20 x 10 ４ ~60 x 10 ４ g / mol.

22. the reaction mixture further comprises a free radical initiator; and / or the reaction mixture further comprises at least one of a dispersant, an interfacial agent, and an organic solvent; the mass content of the dispersant is 50 to 300% of the mass of the polypropylene copolymer; the mass content of the interfacial agent is 1 to 30% of the mass of the polypropylene copolymer; The method according to any one of claims 18 to 21, wherein the mass content of the organic solvent is 1 to 35% of the mass of the polypropylene copolymer.

23. the free radical initiator is selected from a peroxide-based free radical initiator and / or an azo-based free radical initiator; the peroxide free radical initiator is at least one selected from dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, dodecyl peroxide, tert-butylperoxybenzoic acid, diisopropyl peroxydicarbonate, tert-butylperoxy(2-ethylhexanoate), and dicyclohexyl peroxydicarbonate; 23. The method of claim 22, wherein the azo-based free radical initiator is azobisisobutyronitrile and / or azobisisoheptonitrile.

24. The preparation method comprises the steps of: (a) placing the polypropylene copolymer in a sealed reactor and then replacing the atmosphere with an inert gas; (b) adding a free radical initiator and an alkenyl-containing polymerizable monomer to the closed reactor and mixing with stirring; (c) optionally adding an interfacial agent and optionally swelling the reaction system; (d) optionally adding a dispersant and heating the reaction system to a grafting reaction temperature to carry out the grafting reaction; (e) after completion of the reaction, optionally filtering and drying to obtain the graft-modified polypropylene material; or The preparation method comprises the steps of: (a) placing the polypropylene copolymer in a sealed reactor and then replacing the atmosphere with an inert gas; (b) mixing an organic solvent with a free radical initiator and adding the mixture to a closed reactor; (c) removing the organic solvent; (d) adding an alkenyl-containing polymerizable monomer, optionally adding a surfactant, and optionally swelling the reaction system; (e) optionally adding a dispersant and heating the reaction system to a grafting reaction temperature to carry out the grafting reaction; (f) after completion of the reaction, optionally filtering and drying to obtain the graft-modified polypropylene material; The method according to any one of claims 18 to 23.

25. The method according to any one of claims 18 to 24, wherein the temperature of the grafting reaction is from 30 to 130°C, or from 60 to 120°C, and the time is from 0.5 to 10 hours, or from 1 to 5 hours.

26. A method for preparing a graft-modified polypropylene material for insulating materials, comprising: grafting a reaction mixture comprising a polypropylene copolymer and an alkenyl-containing polymerizable monomer in the presence of an inert gas to obtain the graft-modified polypropylene material; the graft-modified polypropylene material is an aromatic olefin graft-modified polypropylene material; the alkenyl-containing polymerizable monomer is a styrene monomer; The grafting reaction conditions are as follows: the content of the structural units derived from the styrene monomer and in a grafted state in the aromatic olefin graft-modified polypropylene material is 0.5 to 14 wt % relative to the weight of the aromatic olefin graft-modified polypropylene material; The polypropylene copolymer has at least one of the following characteristics: The comonomer content is 0.5 to 40 mol%; The content of xylene solubles is 2 to 80% by weight; The content of the comonomer in the xylene soluble matter is 10 to 70% by weight; The ratio of the intrinsic viscosity of the xylene soluble material to the polypropylene copolymer is 0.3 to 5.

27. 27. The method according to claim 26, wherein the content of structural units derived from the styrene monomer and in a grafted state in the aromatic olefin-grafted polypropylene material is 1 to 7.5 wt %, or 1.5 to 5 wt %, based on the weight of the aromatic olefin-grafted polypropylene material.

28. the styrene monomer is at least one selected from a monomer having a structure represented by formula 8, a monomer having a structure represented by formula 9, and a monomer having a structure represented by formula 10; [Chemistry 18] In formula 8, R １ , R ２ , R ３ are each independently H, substituted or unsubstituted C １ -C ６ alkyl; R ４ -R ８ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups, 【Chemistry 19】 In formula 9, R １ , R ２ , R ３ are each independently H, substituted or unsubstituted C １ -C ６ alkyl; R ４ -R １０ are each independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ amine groups; 【Chemistry 20】 In formula 10, R １ ', R ２ ', R ３ Each ' is independently H, substituted or unsubstituted C １ -C ６ alkyl; R ４ '-R １０ Each ' is independently H, halogen, hydroxy, amino, phosphate, sulfonate, substituted or unsubstituted C １ -C １２ Alkyl, substituted or unsubstituted C ３ -C １２ Cycloalkyl, substituted or unsubstituted C １ -C １２ Alkoxy, substituted or unsubstituted C １ -C １２ an ester group, substituted or unsubstituted C １ -C １２ amine groups, the substituents of which are selected from halogen, hydroxy, amino, phosphate groups, sulfonate groups, C １ -C １２ Alkyl, C ３ -C １２ Cycloalkyl, C １ -C １２ Alkoxy, C １ -C １２ Ester group, C １ -C １２ 27. The method of claim 26, wherein the amine group is selected from the group consisting of amine groups.

29. the reaction mixture further comprises a free radical initiator; the weight ratio of the free radical initiator to the styrene monomer is 0.1 to 10:100, or 0.5 to 5:100; and / or 27. The method of claim 26, wherein the mass ratio of the styrene monomer to the polypropylene copolymer is 0.5 to 16:100, or 1 to 12:100, or 2 to 10:

100.

30. Use of the graft-modified polypropylene material according to any one of claims 1 to 17 as an insulating material.

31. The graft-modified polypropylene material for insulating materials according to any one of claims 1 to 17, wherein the insulating material is a cable insulating material.

32. The graft-modified polypropylene material for insulating materials according to any one of claims 1 to 17, wherein the insulating material is a direct current cable insulating material.

33. The graft-modified polypropylene material for insulating materials according to any one of claims 1 to 17, wherein the insulating material is a cable insulating layer material.

34. at least one conductor and at least one electrically insulating layer surrounding the conductor; A cable, wherein the material of the electrical insulating layer is at least one graft-modified polypropylene material according to any one of claims 1 to 17.

35. the cable having at least one cable core; Each cable core includes, from the inside to the outside, a conductor, an optional conductor shielding layer, an electrically insulating layer, an optional electrically insulating shielding layer, and an optional metallic shielding layer; 35. The cable of claim 34, wherein optionally the cable further comprises an armor and / or a sheath layer and / or a filling layer and / or a wrapping layer.

36. 35. The cable of claim 34, wherein the cable is a DC cable or an AC cable.

37. An insulating material comprising at least one graft-modified polypropylene material according to any one of claims 1 to 17.

38. 38. The insulating material of claim 37, wherein the content of the at least one graft-modified polypropylene material is 20-100% by weight, or 40-100% by weight, or 60-100% by weight, or 80-100% by weight, or 90-100% by weight, based on the weight of the insulating material.

39. 39. The insulating material of claim 37 or 38, further comprising one or more selected from antioxidants, stabilizers, processing aids, flame retardants, water tree retarding additives, acid or ion scavengers, inorganic fillers, voltage stabilizers, and copper inhibitors.

40. The use described in claim 30, wherein the insulating material is a cable insulating material.

41. The use described in claim 30, wherein the insulating material is a DC cable insulating material.

42. The use described in claim 30, wherein the insulating material is a cable insulating layer material.

Images