Low-odor ratproof extrusion-grade polypropylene material, preparation method and electrical material

Abstract

The invention provides a low-odor ratproof extrusion-grade polypropylene material, a preparation method and an electrical material, and belongs to the field of polypropylene materials. The polypropylene is used as a main body, the flexibilizer is used for modifying the polypropylene, the used flexibilizer is linear low-density polyethylene and polyolefin elastomer, the melt strength of the flexibilizer is higher, the flexibilizer and the polypropylene are all olefins and have good compatibility, the price of the low-density polyethylene is lower, and the price of the polyolefin elastomer is higher, so that the low-density polyethylene, the polyolefin elastomer and the low-density polyethylene are combined, and the polypropylene is modified. According to the low-odor rat-proof extrusion-grade polypropylene material, the impact resistance of the polypropylene material is enhanced while the production cost is guaranteed, meanwhile, in order to improve the flame retardance of the low-odor rat-proof extrusion-grade polypropylene material, the flame retardant and the mineral substances are added, and the rat-proof agent is further added to prevent the material from being bitten by rats and insects and causing damage to the material; in addition, a special thread element is used in the double-screw extruder, so that the feeding amount is increased, the shearing heat is reduced, the melt temperature is reduced, and the odor grade of the material is reduced.

Description

Technical Field

[0001] The invention relates to the field of polypropylene materials, and in particular to a low-odor rodent-proof extrusion-grade polypropylene material and a preparation method and electrical material. Background Art

[0002] Polypropylene is a thermoplastic synthetic resin with excellent performance. It is a colorless, translucent, thermoplastic, lightweight general-purpose plastic with chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties, and good high-wear-resistant processing properties. Polypropylene is also divided into homopolymer polypropylene, block copolymer polypropylene, and random copolymer polypropylene. Homopolymer polypropylene is polymerized from a single propylene monomer, and its molecular chain regularity is very high, so the material has high crystallinity and poor impact performance; block copolymer polypropylene is obtained by copolymerizing propylene and part of ethylene, and the ethylene content is generally 7-15%, and the impact resistance is good; random copolymer polypropylene is obtained by copolymerizing propylene monomer and a small amount of ethylene (1%-4%) monomer under heating, pressure and catalyst, and the ethylene monomer is randomly and randomly distributed in the long chain of propylene. The random addition of ethylene reduces the crystallinity and melting point of the polymer and improves the impact performance of the material.

[0003] However, one of the disadvantages of polypropylene is its low melt strength and poor sag resistance. Usually, amorphous polymers (such as ABS and PS) have elastic behavior similar to rubber in a wide temperature range, while semi-crystalline polypropylene does not. This disadvantage makes polypropylene unable to be thermoformed in a wide temperature range. Its softening point and melting point are very close. Once the melting point is reached, the melt viscosity drops sharply, and the melt strength also drops significantly, resulting in uneven wall thickness of the product during thermoforming, collapse of the extruded foaming holes, and other problems, which greatly limits the application of polypropylene in some aspects.

[0004] In order to improve the comprehensive properties of polypropylene such as melt strength and modulus, polypropylene is often modified by copolymerization modification, grafting modification, cross-linking modification or blending modification.

[0005] CN114591508B discloses a method for preparing high-purity graft-modified polypropylene, comprising the following steps: (1) adding polypropylene, graft monomer and initiator into an extruder, injecting supercritical CO2 fluid into the extruder, and cooling after melt extrusion to obtain graft-modified polypropylene; (2) adding graft-modified polypropylene and entrainer into an extruder, injecting supercritical CO2 fluid into the extruder, and cooling after melt extrusion to obtain the high-purity graft-modified polypropylene. In the present invention, after the graft copolymerization reaction, the copolymerization product is extracted by supercritical CO2 fluid to remove oligomers and small molecular volatiles in the product, thereby improving product performance.

[0006] CN107118436A discloses a polypropylene blended modified plastic, comprising the following components: 75-95 parts of polypropylene, 15-25 parts of polyethylene crosslinked material, 5-10 parts of triallyl isocyanurate, 20-26 parts of a compatibilizer, 1-3 parts of a coupling agent, 1-10 parts of a filler and 0.2-0.6 parts of an antioxidant; wherein the polyethylene crosslinked material is made of 50-80wt% of metallocene polyethylene, 10-30wt% of high-density polyethylene, 1-10wt% of mica powder and 0.1-1wt% of a crosslinking agent. The modified material has both a rigid toughening effect and impact resistance.

[0007] CN117700882A discloses a polypropylene composition, a preparation method and an application. The polypropylene composition is prepared by mixing and melt extruding the following components according to the following weight parts using a special screw element screw combination: 49-89 parts of polypropylene resin, 0-20 parts of filling powder, 5-10 parts of styrene elastomer, 5-20 parts of linear low-density polyethylene, 0.2-0.6 parts of antioxidant, and 0.2-0.4 parts of light stabilizer.

[0008] The melt strength and impact resistance of modified polypropylene are significantly improved, and it can be used as electrical and information equipment, wires, cables and battery shells / skins. However, when used as electrical materials, long-term use will increase the resistance of the wires, causing the outer skin of the polypropylene material to heat up or even burn. Therefore, the flame retardant properties of polypropylene still need to be enhanced due to its use conditions. In addition, during the use of polypropylene, it is often bitten by rats and ants, resulting in material damage, leakage and even fire.

[0009] In summary, polypropylene material itself has poor impact resistance and low melt strength. After modification, the impact resistance and modulus of polypropylene material are increased, and it has suitable melt strength, but its flame retardancy still cannot meet the requirements of industrialization. In addition, the poor rodent-proof performance of polypropylene material is also a problem that needs to be solved urgently. Summary of the invention

[0010] In view of the above problems, the present invention provides a low-odor rodent-proof extrusion-grade polypropylene material, a preparation method and an electrical material. The present invention modifies the polypropylene material and provides the polypropylene material with high impact resistance, flame retardancy and rodent-proofness by adding suitable rodent-proofing agents and flame retardants to the polypropylene material. In addition, a special threaded element is arranged in a twin-screw extruder to increase the feed amount of the material and reduce the shear heat of the material in the twin-screw extruder, so that the processing process of the material is maintained at a suitable temperature, thereby obtaining a polypropylene material with low odor.

[0011] The invention provides a low-odor rodent-proof extrusion-grade polypropylene material. The low-odor rodent-proof extrusion-grade polypropylene material is prepared by mixing polypropylene, a toughening agent, a mineral substance, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder. The low-odor rodent-proof extrusion-grade polypropylene material has a 230°C / 2.16kg melt index of 1-3g / min, a 23°C cantilever beam notched impact strength of 30-50kJ / m 2 , melt strength is 30000-100000Pa·s, odor level is 2-4, rodent resistance rate is 90-100%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the low-odor rodent-proof extrusion-grade polypropylene material are: Polypropylene: 40-58 parts by weight; Toughening agent: 10-20 parts by weight; Minerals: 10-20 parts by weight; Flame retardant: 15-25 parts by weight; Rodent repellent: 0.15-0.5 parts by weight; Antioxidant: 0.1-1 parts by weight; Lubricant: 0.1-1 parts by weight.

[0012] Furthermore, the special threaded element comprises an SFV spade-shaped threaded element, a TKD low-temperature shear block element and a tensile element, and the inner diameters of the SFV spade-shaped threaded element, the TKD low-temperature shear block element and the tensile element are all 30 mm.

[0013] Further, the SFV spade-shaped threaded elements include SFV70 / 70 and SFVN70 / 20, the TKD low-temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0014] Further, the combined screw structure of the twin-screw extruder is sequentially divided into a first conveying section, a first meshing section, a second conveying section, a second meshing section, a third conveying section, a third meshing section, a fourth conveying section, a fourth meshing section, a fifth conveying section, a fifth meshing section, a sixth conveying section, a sixth meshing section and a seventh conveying section; The first conveying section includes conveying blocks with pitch / total length of 32 / 32A, SFV70 / 70, SFV70 / 70, SFVN70 / 20, 48 / 48, and 32 / 32 arranged in sequence; The first meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as TKD45° / 5 / 32, TKD45° / 5 / 32, and TKD45° / 5 / 32; The second conveying section includes conveying blocks with pitch / total length of 32 / 32 and 32 / 32 arranged in sequence; The second engagement section includes engagement blocks whose engagement disc angle / number of engagement discs / total length are arranged in sequence as 60° / 4 / 32 and 60° / 4 / 32; The third conveying section includes conveying blocks with pitch / total length of 32 / 32 and 48 / 48 arranged in sequence; The third meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 90° / 5 / 32, 60° / 4 / 32, and 45° / 5 / 22L; The fourth conveying section includes conveying blocks with pitch / total length of 48 / 48, SK48 / 48, SK48 / 48, SK48 / 48, SK48 / 48, 48 / 48, and 32 / 32 arranged in sequence; The fourth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 45° / 5 / 32, and 45° / 4 / 32; The fifth conveying section includes conveying blocks with a pitch / total length of 32 / 32 arranged in sequence; The fifth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32 and 90° / 5 / 32; The sixth conveying section includes conveying blocks with pitches / total lengths of 32 / 32, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 32 / 32 arranged in sequence; The sixth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 60° / 4 / 32, 45° / 5 / 32, and 90° / 5 / 32; The seventh conveying section includes conveying blocks with pitch / total length of 32 / 32, 192 / 48, 192 / 48L, 32 / 32, 32 / 32, 22 / 11L, 48 / 48, 48 / 48, 48 / 48, 32 / 32, 32 / 32, 22 / 22, and 22 / 22, which are arranged in sequence.

[0015] Furthermore, the melt index of the polypropylene at 230°C / 2.16kg is 0.1-10g / 10min.

[0016] Furthermore, the polypropylene includes block copolymer polypropylene and random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3-10g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.1-2g / 10min.

[0017] Furthermore, the toughening agent is one or more of linear low-density polyethylene (LLDPE) and polyolefin elastomer (POE).

[0018] Furthermore, the linear low-density polyethylene (LLDPE) has a melt index of 1-3 g / 10 min at 230° C. / 2.16 kg.

[0019] Furthermore, the mineral is one or more of barium sulfate, calcium carbonate, talc and wollastonite.

[0020] Furthermore, the flame retardant is one or more of tetrabromobisphenol A, decabromodiphenylethane, brominated epoxy resin, octabromotriphenyl ether, brominated polystyrene and antimony trioxide.

[0021] Furthermore, the rodent repellent is compounded by aromatic plant oil and one or two of capsaicin or bitter compounds.

[0022] Furthermore, the ratio of the mass of the aromatic plant oil to the total mass of capsaicin and / or bitter compounds is (1:1)-(3:1).

[0023] Furthermore, the antioxidant is compounded by a main antioxidant and an auxiliary antioxidant in a mass ratio of 1:1.

[0024] Further, the primary antioxidant is a hindered phenol antioxidant, including one or more of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; Or sulfate antioxidants, including one or more of lauryl thiodipropionate (DLTDP) and octadecyl thiodipropionate (DSTDP).

[0025] Further, the auxiliary antioxidant is a phosphite antioxidant, including triphenylphosphonic acid diester; Or phosphite antioxidants, including one or more of tris(2,4-di-tert-butylphenyl) phosphite and bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

[0026] Furthermore, the lubricant is one or more of calcium stearate, glyceryl stearate and ethylene bisstearamide.

[0027] The present invention also provides a method for preparing the low-odor rodent-proof extrusion-grade polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer to obtain a mixture; Step 2: discharge the mixed material from the discharge port of a twin-screw extruder, extrude it through the twin-screw extruder, water-cool it at room temperature, and then naturally air-dry it to obtain the low-odor rodent-proof extrusion-grade polypropylene material.

[0028] Furthermore, the melt index of the polypropylene at 230°C / 2.16kg in the step 1 is 0.1-10g / 10min. Specifically, the polypropylene includes block copolymer polypropylene and random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3-10g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.1-2g / 10min.

[0029] Furthermore, the toughening agent in step 1 is one or more of linear low-density polyethylene (LLDPE) and polyolefin elastomer (POE), wherein the melt index of the linear low-density polyethylene (LLDPE) under the conditions of 230°C / 2.16kg is 1-3g / 10min.

[0030] Furthermore, the mineral in step 1 is one or more of barium sulfate, calcium carbonate, talc and wollastonite.

[0031] Furthermore, the flame retardant in step 1 is one or more of tetrabromobisphenol A, decabromodiphenylethane, brominated epoxy resin, octabromotriphenyl ether, brominated polystyrene and antimony trioxide.

[0032] Furthermore, the rodent repellent in step 1 is compounded with aromatic plant oil and one or two of capsaicin or bitter compounds.

[0033] Furthermore, the ratio of the mass of the aromatic plant oil to the total mass of capsaicin and / or bitter compounds is (1:1)-(3:1).

[0034] Furthermore, the antioxidant in step 1 is compounded by a primary antioxidant and a secondary antioxidant in a mass ratio of 1:1.

[0035] Further, the primary antioxidant is a hindered phenol antioxidant, including one or more of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; Or sulfate antioxidants, including one or more of lauryl thiodipropionate (DLTDP) and octadecyl thiodipropionate (DSTDP).

[0036] Further, the auxiliary antioxidant is a phosphite antioxidant, including triphenylphosphonic acid diester; Or phosphite antioxidants, including one or more of tris(2,4-di-tert-butylphenyl) phosphite and bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

[0037] Furthermore, the lubricant in step 1 is one or more of calcium stearate, glyceryl stearate and ethylene bisstearamide.

[0038] Furthermore, in step 1, the rotation speed of the high-speed mixer is 1000-2000 r / min, and the mixing time is 1-3 min.

[0039] Further, the processing temperature of the twin-screw extruder in the step 2 is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 180-190°C, the temperature of the second temperature zone is 180-190°C, the temperature of the third temperature zone is 180-190°C, the temperature of the fourth temperature zone is 180-190°C, the temperature of the fifth temperature zone is 170-180°C, the temperature of the sixth temperature zone is 170-180°C, the temperature of the seventh temperature zone is 170-180°C, the temperature of the eighth temperature zone is 160-170°C, the temperature of the ninth temperature zone is 160-170°C, the temperature of the tenth temperature zone is 160-170°C, the temperature of the eleventh temperature zone is 170-180°C, the temperature of the twelfth temperature zone is 180-190°C, the temperature of the thirteenth temperature zone is 180-190°C, and the temperature of the fourteenth temperature zone is 180-190°C.

[0040] Furthermore, the special threaded element in step 2 includes a SFV spade-shaped threaded element, a TKD low-temperature shear block element and a tensile element, and the inner diameters of the SFV spade-shaped threaded element, the TKD low-temperature shear block element and the tensile element are all 30 mm; The SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder.

[0041] Further, the SFV spade-shaped threaded elements include SFV70 / 70 and SFVN70 / 20, the TKD low-temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0042] Further, the combined screw structure of the twin-screw extruder in step 2 is sequentially divided into a first conveying section, a first meshing section, a second conveying section, a second meshing section, a third conveying section, a third meshing section, a fourth conveying section, a fourth meshing section, a fifth conveying section, a fifth meshing section, a sixth conveying section, a sixth meshing section and a seventh conveying section; The first conveying section includes conveying blocks with pitch / total length of 32 / 32A, SFV70 / 70, SFV70 / 70, SFVN70 / 20, 48 / 48, and 32 / 32 arranged in sequence; The first engagement section includes engagement blocks whose engagement disc angle / number of engagement discs / total length are arranged in sequence as TKD45° / 5 / 32, TKD45° / 5 / 32, and TKD45° / 5 / 32; The second conveying section includes conveying blocks with pitch / total length of 32 / 32 and 32 / 32 arranged in sequence; The second engagement section includes engagement blocks whose engagement disc angle / number of engagement discs / total length are arranged in sequence as 60° / 4 / 32 and 60° / 4 / 32; The third conveying section includes conveying blocks with pitch / total length of 32 / 32 and 48 / 48 arranged in sequence; The third meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 90° / 5 / 32, 60° / 4 / 32, and 45° / 5 / 22L; The fourth conveying section includes conveying blocks with pitch / total length of 48 / 48, SK48 / 48, SK48 / 48, SK48 / 48, SK48 / 48, 48 / 48, and 32 / 32 arranged in sequence; The fourth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 45° / 5 / 32, and 45° / 4 / 32; The fifth conveying section includes conveying blocks with a pitch / total length of 32 / 32 arranged in sequence; The fifth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32 and 90° / 5 / 32; The sixth conveying section includes conveying blocks with pitches / total lengths of 32 / 32, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 32 / 32 arranged in sequence; The sixth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 60° / 4 / 32, 45° / 5 / 32, and 90° / 5 / 32; The seventh conveying section includes conveying blocks with pitch / total length of 32 / 32, 192 / 48, 192 / 48L, 32 / 32, 32 / 32, 22 / 11L, 48 / 48, 48 / 48, 48 / 48, 32 / 32, 32 / 32, 22 / 22, and 22 / 22, which are arranged in sequence.

[0043] Furthermore, the melt temperature of the twin-screw extruder in step 2 is 230-260°C.

[0044] Furthermore, the screw speed of the twin-screw extruder in step 2 is 300-700 rpm.

[0045] Furthermore, the aspect ratio of the twin-screw extruder in step 2 is 60:1.

[0046] Furthermore, the torque of the twin-screw extruder in step 2 is 50-70 N•m.

[0047] Furthermore, the main engine current of the twin-screw extruder in step 2 is 300-350A.

[0048] Furthermore, the feeding rate of the twin-screw extruder in step 2 is 30-50kg / h.

[0049] The present invention also provides an electrical material, which is prepared from the low-odor rodent-proof extrusion-grade polypropylene material, and comprises an outer layer of an electric wire, a cable or an electrical casing.

[0050] Beneficial effects of the present invention: 1. Random copolymer polypropylene has high melt strength but low modulus, while block copolymer polypropylene has low melt strength but high modulus. The present invention mixes block copolymer polypropylene and random copolymer polypropylene to meet the requirements of melt strength and modulus. The present invention uses polypropylene as the main body and uses a toughening agent to modify the polypropylene. The toughening agent used in the present invention is linear low-density polyethylene and polyolefin elastomer. The melt index of the linear low-density polyethylene is 1-3g / 10min, and its melt strength is high. Both the linear low-density polyethylene and polypropylene are olefins, and have good compatibility. The price of low-density polyethylene is low, and the price of polyolefin elastomer is high. While ensuring the production cost, the impact resistance of the polypropylene material is also enhanced. At the same time, the melt index of the polypropylene is less than 10g / min, and it will not be difficult to form due to excessive melt index during co-extrusion; 2. In order to improve the flame retardancy of the low-odor rodent-proof extrusion-grade polypropylene material, the present invention adds a flame retardant and a mineral. The flame retardant is a halogen flame retardant. The halogen flame retardant has good compatibility with the polypropylene material, is not easy to precipitate after long-term use, and has good heat resistance. However, the amount of halogen flame retardant required for use is large, which increases the production cost and operation process. Therefore, minerals are also added to the system. The minerals are combined with the flame retardant to reduce the cost, achieve the flame retardant effect, and also reduce the amount of flame retardant added; 3. The low-odor rodent-proof extrusion-grade polypropylene material of the present invention is easily bitten by rodents and insects, resulting in material damage, so a rodent-proofing agent is added thereto. The rodent-proofing agent is composed of aromatic plant oil and capsaicin and / or bitter compounds. Capsaicin and bitter compounds have strong odors. When they are added alone as rodent-proofing agents, a large amount is required, which will cause workers in the production process to feel very uncomfortable. Therefore, the present invention mixes aromatic plant oil with capsaicin and / or bitter compounds, reduces the amount of capsaicin and / or bitter compounds used, and also reduces the processing temperature, reduces the volatility of the odor of the rodent-proofing agent, ensures the production environment, and also reduces the odor of the low-odor rodent-proof extrusion-grade polypropylene material, while having rodent-proofing performance; 4. The present invention also uses special thread elements in the twin-screw extruder. First, the SFV spade-shaped thread element is used at the feed port to replace the ordinary SK spade-shaped thread element, which increases the feed rate of the twin-screw extruder. The feed rate can be increased by 28%. At the same time, due to the increase in feed rate, more materials are filled in the screw, the overall shear heat is reduced, the melt temperature is reduced, and the odor level of the material is reduced; secondly, the TKD low-temperature shear block element is used in the third temperature zone of the twin-screw extruder. The curved surface of the TKD low-temperature shear block element is designed according to the curved surface of the thread sleeve, which reduces Shear heat of the material; finally, the stretching element is set in the seventh temperature zone of the twin-screw extruder. The stretching element consists of forward stretching + reverse stretching, has a significant wedge-shaped area, can realize axial stretching flow, is placed in the rear section of the plasticized material, has a strong dispersion and distribution ability, further reduces the generation of small molecules, reduces the odor of the material, and the processing temperature range of the twin-screw extruder in the present invention is 170-190°C. At this processing temperature, polypropylene will not suffer from serious chain scission, and the melt strength will not be greatly reduced, thereby affecting the performance; 5. The aspect ratio of the twin-screw extruder in the present invention is 60:1. The larger aspect ratio increases the mixing reaction time of the materials in the twin-screw extruder, so that the materials are fully mixed. In addition, the low-odor rat-proof extrusion-grade polypropylene material prepared in the present invention has good impact resistance, strong flame retardancy, rat-proofing, and low odor. The process for preparing the low-odor rat-proof extrusion-grade polypropylene material is simple, easy to operate, and suitable for expanded production. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The screw structure diagram of the twin-screw extruder including the special screw element of the present invention; Figure 2 It is a structural schematic diagram of the SFV spade-shaped thread element described in the present invention; Figure 3 It is a schematic diagram of the structure of the TKD low-temperature shear block element of the present invention; Figure 4 It is a schematic diagram of the structure of the tensile element described in the present invention. DETAILED DESCRIPTION

[0052] The invention is described in detail below with reference to the embodiments: The invention provides a low-odor rodent-proof extrusion-grade polypropylene material, a preparation method and an electrical material. The low-odor rodent-proof extrusion-grade polypropylene material is prepared by mixing and extruding polypropylene, a toughening agent, a mineral, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant to prepare the low-odor rodent-proof extrusion-grade polypropylene material with high impact resistance, flame retardancy, rodent-proofness and low odor.

[0053] Example 1 The present embodiment provides a low-odor rodent-proof extrusion-grade polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the low-odor rodent-proof extrusion-grade polypropylene material has a 230°C / 2.16kg melt index of 2g / min, a 23°C notched cantilever beam impact strength of 35kJ / m 2 , melt strength is 33320Pa·s, odor level is 3.5, rodent resistance rate is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the low-odor rodent-proof extrusion-grade polypropylene material are: Polypropylene: 40 parts by weight; Toughening agent: 20 parts by weight; Minerals: 16 parts by weight; Flame retardant: 23 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0054] In this embodiment, the polypropylene is 30 parts by weight of block copolymer polypropylene and 10 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 20 parts by weight of linear low-density polyethylene (LLDPE), wherein the melt index of the linear low-density polyethylene (LLDPE) under the conditions of 230°C / 2.16kg is 1g / 10min; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0055] This embodiment also provides a method for preparing the low-odor rodent-proof extrusion-grade polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a speed of 1500 r / min for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from the discharge port of a twin-screw extruder, extrude it through the twin-screw extruder, water-cool it at room temperature, and then naturally air-dry it to obtain the low-odor rodent-proof extrusion-grade polypropylene material.

[0056] In this embodiment, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 250°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 50N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0057] Example 2 The present embodiment provides a low-odor rodent-proof extrusion-grade polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the low-odor rodent-proof extrusion-grade polypropylene material has a 230°C / 2.16kg melt index of 1.8 g / min, a 23°C notched cantilever beam impact strength of 33 kJ / m 2 , melt strength is 37022Pa·s, odor level is 3.5, rodent resistance rate is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the low-odor rodent-proof extrusion-grade polypropylene material are: Polypropylene: 40 parts by weight; Toughening agent: 20 parts by weight; Minerals: 16 parts by weight; Flame retardant: 23 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0058] In this embodiment, the polypropylene is 20 parts by weight of block copolymer polypropylene and 20 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 20 parts by weight of linear low-density polyethylene (LLDPE), wherein the melt index of the linear low-density polyethylene (LLDPE) under the conditions of 230°C / 2.16kg is 1g / 10min; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0059] This embodiment also provides a method for preparing the low-odor rodent-proof extrusion-grade polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a speed of 1500 r / min for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from the discharge port of a twin-screw extruder, extrude it through the twin-screw extruder, water-cool it at room temperature, and then naturally air-dry it to obtain the low-odor rodent-proof extrusion-grade polypropylene material.

[0060] In this embodiment, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 250°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 50N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0061] Example 3 The present embodiment provides a low-odor rodent-proof extrusion-grade polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the low-odor rodent-proof extrusion-grade polypropylene material has a 230°C / 2.16kg melt index of 1.5 g / min, a 23°C notched cantilever beam impact strength of 30 kJ / m 2, melt strength is 56100Pa·s, odor level is 3.5, rodent resistance rate is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the low-odor rodent-proof extrusion-grade polypropylene material are: Polypropylene: 40 parts by weight; Toughening agent: 20 parts by weight; Minerals: 16 parts by weight; Flame retardant: 23 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0062] In this embodiment, the polypropylene is 10 parts by weight of block copolymer polypropylene and 30 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 20 parts by weight of linear low-density polyethylene (LLDPE), wherein the melt index of the linear low-density polyethylene (LLDPE) under the conditions of 230°C / 2.16kg is 1g / 10min; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0063] This embodiment also provides a method for preparing the low-odor rodent-proof extrusion-grade polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from the discharge port of a twin-screw extruder, extrude it through the twin-screw extruder, water-cool it at room temperature, and then naturally air-dry it to obtain the low-odor rodent-proof extrusion-grade polypropylene material.

[0064] In this embodiment, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 255°C, a screw speed of 450rpm, a length-to-diameter ratio of 60:1, a torque of 52N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0065] Example 4 The present embodiment provides a low-odor rodent-proof extrusion-grade polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the low-odor rodent-proof extrusion-grade polypropylene material has a 230°C / 2.16kg melt index of 1g / min, a 23°C notched cantilever beam impact strength of 42kJ / m 2 , melt strength is 87040Pa·s, odor level is 3.5, rodent resistance is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the low-odor rodent-proof extrusion-grade polypropylene material are: Polypropylene: 45 parts by weight; Toughening agent: 15 parts by weight; Minerals: 16 parts by weight; Flame retardant: 23 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0066] In this embodiment, the polypropylene is 25 parts by weight of block copolymer polypropylene and 20 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 10 parts by weight of linear low-density polyethylene (LLDPE) and 5 parts by weight of polyolefin elastomer (POE), wherein the linear low-density polyethylene (LLDPE) has a melt index of 1 g / 10 min at 230°C / 2.16 kg, and the polyolefin elastomer (POE) has a melt index of 3 g / 10 min at 230°C / 2.16 kg; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0067] This embodiment also provides a method for preparing the low-odor rodent-proof extrusion-grade polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from the discharge port of a twin-screw extruder, extrude it through the twin-screw extruder, water-cool it at room temperature, and then naturally air-dry it to obtain the low-odor rodent-proof extrusion-grade polypropylene material.

[0068] In this embodiment, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 255°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 55N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0069] Comparative Example 1 This comparative example provides a polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent repellent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the polypropylene material has a 230°C / 2.16kg melt index of 2g / min, a 23°C notched cantilever beam impact strength of 25kJ / m 2 , melt strength is 22482Pa·s, odor level is 3.5, rodent resistance rate is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the polypropylene material are: Polypropylene: 45 parts by weight; Toughening agent: 15 parts by weight; Minerals: 18 parts by weight; Flame retardant: 20 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0070] In this comparative example, the polypropylene is 45 parts by weight of homopolymer polypropylene, wherein the melt index of the homopolymer polypropylene at 230°C / 2.16kg is 3g / 10min; The toughening agent is 10 parts by weight of linear low-density polyethylene (LLDPE) and 5 parts by weight of polyolefin elastomer (POE), wherein the linear low-density polyethylene (LLDPE) has a melt index of 1 g / 10 min at 230°C / 2.16 kg, and the polyolefin elastomer (POE) has a melt index of 3 g / 10 min at 230°C / 2.16 kg; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0071] This comparative example also provides a method for preparing the polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from a feeding port of a twin-screw extruder, extrude the mixed material through the twin-screw extruder, and cool the mixed material with water at room temperature and then naturally air-dry the mixed material to obtain the polypropylene material.

[0072] In this comparative example, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 250°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 45N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0073] Comparative Example 2 This comparative example provides a polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent repellent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the polypropylene material has a 230°C / 2.16kg melt index of 1.5g / min, a 23°C Izod notched impact strength of 38kJ / m 2 , melt strength is 35416Pa·s, odor level is 4, rodent resistance is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the polypropylene material are: Polypropylene: 45 parts by weight; Toughening agent: 15 parts by weight; Minerals: 18 parts by weight; Flame retardant: 20 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0074] In this comparative example, the polypropylene is 25 parts by weight of block copolymer polypropylene and 20 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 10 parts by weight of linear low-density polyethylene (LLDPE) and 5 parts by weight of polyolefin elastomer (POE), wherein the linear low-density polyethylene (LLDPE) has a melt index of 1 g / 10 min at 230°C / 2.16 kg, and the polyolefin elastomer (POE) has a melt index of 3 g / 10 min at 230°C / 2.16 kg; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special threaded element includes a TKD low-temperature shear block element, and the inner diameter of the TKD low-temperature shear block element is 30 mm; the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder; The TKD low temperature shear block element includes TKD45° / 5 / 32.

[0075] This comparative example also provides a method for preparing the polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from a feeding port of a twin-screw extruder, extrude the mixed material through the twin-screw extruder, and cool the mixed material with water at room temperature and then naturally air-dry the mixed material to obtain the polypropylene material.

[0076] In this comparative example, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 250°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 48N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0077] Comparative Example 3 This comparative example provides a polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent repellent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the polypropylene material has a 230°C / 2.16kg melt index of 1.5 g / min, a 23°C Izod notched impact strength of 37 kJ / m 2 , melt strength is 44426Pa·s, odor level is 4, rodent resistance is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the polypropylene material are: Polypropylene: 45 parts by weight; Toughening agent: 15 parts by weight; Minerals: 18 parts by weight; Flame retardant: 20 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0078] In this comparative example, the polypropylene is 25 parts by weight of block copolymer polypropylene and 20 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 10 parts by weight of linear low-density polyethylene (LLDPE) and 5 parts by weight of polyolefin elastomer (POE), wherein the linear low-density polyethylene (LLDPE) has a melt index of 1 g / 10 min at 230°C / 2.16 kg, and the polyolefin elastomer (POE) has a melt index of 3 g / 10 min at 230°C / 2.16 kg; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element and a stretching element, and the inner diameters of the SFV spade-shaped thread element and the stretching element are both 30 mm; the SFV spade-shaped thread element is installed at the discharge port of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, and the tensile elements include 192 / 48 and 192 / 48L.

[0079] This comparative example also provides a method for preparing the polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from a feeding port of a twin-screw extruder, extrude the mixed material through the twin-screw extruder, and cool the mixed material with water at room temperature and then naturally air-dry the mixed material to obtain the polypropylene material.

[0080] In this comparative example, the processing temperature of the twin-screw extruder is 180-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 260°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 49N•m, a main engine current of 340A, and a feed rate of 45kg / h.

[0081] Comparative Example 4 This comparative example provides a polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent repellent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the polypropylene material has a 230°C / 2.16kg melt index of 2g / min, a 23°C notched cantilever beam impact strength of 40kJ / m 2 , melt strength is 17000Pa·s, odor level is 5, rodent resistance rate is 90%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the polypropylene material are: Polypropylene: 45 parts by weight; Toughening agent: 15 parts by weight; Minerals: 18 parts by weight; Flame retardant: 20 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0082] In this comparative example, the polypropylene is 25 parts by weight of block copolymer polypropylene and 20 parts by weight of random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.5g / 10min; The toughening agent is 10 parts by weight of linear low-density polyethylene (LLDPE) and 5 parts by weight of polyolefin elastomer (POE), wherein the linear low-density polyethylene (LLDPE) has a melt index of 1 g / 10 min at 230°C / 2.16 kg, and the polyolefin elastomer (POE) has a melt index of 3 g / 10 min at 230°C / 2.16 kg; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0083] This comparative example also provides a method for preparing the polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from a feeding port of a twin-screw extruder, extrude the mixed material through the twin-screw extruder, and cool the mixed material with water at room temperature and then naturally air-dry the mixed material to obtain the polypropylene material.

[0084] In this comparative example, the processing temperature of the twin-screw extruder is 190-220°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 220°C, the temperature of the second temperature zone is 220°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 220°C, the temperature of the fifth temperature zone is 220°C, the temperature of the sixth temperature zone is 200°C, the temperature of the seventh temperature zone is 200°C, the temperature of the eighth temperature zone is 200°C, the temperature of the ninth temperature zone is 190°C, the temperature of the tenth temperature zone is 190°C, the temperature of the eleventh temperature zone is 190°C, the temperature of the twelfth temperature zone is 220°C, the temperature of the thirteenth temperature zone is 220°C, and the temperature of the fourteenth temperature zone is 220°C; The twin-screw extruder has a melt temperature of 280°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 42N•m, a main engine current of 339A, and a feed rate of 45kg / h.

[0085] Comparative Example 5 This comparative example provides a polypropylene material, which is prepared by mixing polypropylene, a toughening agent, a mineral, a flame retardant, a rodent repellent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the polypropylene material has a 230°C / 2.16kg melt index of 12 g / min, a 23°C Izod notched impact strength of 28 kJ / m 2 , melt strength is 708Pa·s, odor level is 4, rodent resistance is 90%, and flame retardancy is V1; The twin-screw extruder is equipped with a special screw element; the components and their contents in the polypropylene material are: Polypropylene: 45 parts by weight; Toughening agent: 15 parts by weight; Minerals: 18 parts by weight; Flame retardant: 20 parts by weight; Rodent repellent: 0.5 parts by weight; Antioxidant: 0.3 parts by weight; Lubricant: 0.3 parts by weight.

[0086] In this comparative example, the polypropylene is 25 parts by weight of block copolymer polypropylene and 20 parts by weight of homopolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 17 g / 10min, and the melt index of the homopolymer polypropylene at 230°C / 2.16kg is 30 g / 10min; The toughening agent is 10 parts by weight of linear low-density polyethylene (LLDPE) and 5 parts by weight of polyolefin elastomer (POE), wherein the linear low-density polyethylene (LLDPE) has a melt index of 1 g / 10 min at 230°C / 2.16 kg, and the polyolefin elastomer (POE) has a melt index of 3 g / 10 min at 230°C / 2.16 kg; The mineral is 16 parts by weight of talc; The flame retardant is 18 parts by weight of decabromodiphenylethane and 5 parts by weight of antimony trioxide; The rodent repellent comprises 0.3 parts by weight of aromatic plant oil, 0.1 parts by weight of capsaicin and 0.1 parts by weight of a bitter compound; The antioxidant is 0.15 parts by weight of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 0.15 parts by weight of triphenylphosphonic acid diester; The lubricant is 0.2 parts by weight of ethylene bisstearamide and 0.1 parts by weight of calcium stearate; The special thread element includes an SFV spade-shaped thread element, a TKD low-temperature shear block element and a stretching element, and the inner diameters of the SFV spade-shaped thread element, the TKD low-temperature shear block element and the stretching element are all 30 mm; the SFV spade-shaped thread element is installed at the feed port of the twin-screw extruder, the TKD low-temperature shear block element is installed in the third temperature zone of the twin-screw extruder, and the stretching element is installed in the seventh temperature zone of the twin-screw extruder; The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

[0087] This comparative example also provides a method for preparing the polypropylene material, comprising the following steps: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer at a rotation speed of 1500 rpm for 2 minutes to obtain a mixture; Step 2: discharge the mixed material from a feeding port of a twin-screw extruder, extrude the mixed material through the twin-screw extruder, and cool the mixed material with water at room temperature and then naturally air-dry the mixed material to obtain the polypropylene material.

[0088] In this comparative example, the processing temperature of the twin-screw extruder is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 190°C, the temperature of the fourth temperature zone is 190°C, the temperature of the fifth temperature zone is 180°C, the temperature of the sixth temperature zone is 180°C, the temperature of the seventh temperature zone is 180°C, the temperature of the eighth temperature zone is 170°C, the temperature of the ninth temperature zone is 170°C, the temperature of the tenth temperature zone is 170°C, the temperature of the eleventh temperature zone is 180°C, the temperature of the twelfth temperature zone is 190°C, the temperature of the thirteenth temperature zone is 190°C, and the temperature of the fourteenth temperature zone is 190°C; The twin-screw extruder has a melt temperature of 250°C, a screw speed of 350rpm, a length-to-diameter ratio of 60:1, a torque of 40N•m, a main engine current of 330A, and a feed rate of 45kg / h.

[0089] The combined screw structure of the twin-screw extruder described in Examples 1 to 4 of the present invention is sequentially divided into a first conveying section, a first meshing section, a second conveying section, a second meshing section, a third conveying section, a third meshing section, a fourth conveying section, a fourth meshing section, a fifth conveying section, a fifth meshing section, a sixth conveying section, a sixth meshing section and a seventh conveying section; The first conveying section includes conveying blocks with pitch / total length of 32 / 32A, SFV70 / 70, SFV70 / 70, SFVN70 / 20, 48 / 48, and 32 / 32 arranged in sequence; The first engagement section includes engagement blocks whose engagement disc angle / number of engagement discs / total length are arranged in sequence as TKD45° / 5 / 32, TKD45° / 5 / 32, and TKD45° / 5 / 32; The second conveying section includes conveying blocks with pitch / total length of 32 / 32 and 32 / 32 arranged in sequence; The second engagement section includes engagement blocks whose engagement disc angle / number of engagement discs / total length are arranged in sequence as 60° / 4 / 32 and 60° / 4 / 32; The third conveying section includes conveying blocks with pitch / total length of 32 / 32 and 48 / 48 arranged in sequence; The third meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 90° / 5 / 32, 60° / 4 / 32, and 45° / 5 / 22L; The fourth conveying section includes conveying blocks with pitch / total length of 48 / 48, SK48 / 48, SK48 / 48, SK48 / 48, SK48 / 48, 48 / 48, and 32 / 32 arranged in sequence; The fourth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 45° / 5 / 32, and 45° / 4 / 32; The fifth conveying section includes conveying blocks with a pitch / total length of 32 / 32 arranged in sequence; The fifth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32 and 90° / 5 / 32; The sixth conveying section includes conveying blocks with pitches / total lengths of 32 / 32, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 32 / 32 arranged in sequence; The sixth meshing section includes meshing blocks whose meshing disc angle / number of meshing discs / total length are arranged in sequence as 45° / 5 / 32, 60° / 4 / 32, 45° / 5 / 32, and 90° / 5 / 32; The seventh conveying section includes conveying blocks with pitch / total length of 32 / 32, 192 / 48, 192 / 48L, 32 / 32, 32 / 32, 22 / 11L, 48 / 48, 48 / 48, 48 / 48, 32 / 32, 32 / 32, 22 / 22, and 22 / 22, which are arranged in sequence.

[0090] The SFV spade-shaped threaded elements, TKD low-temperature shear block elements and tensile elements described in the present invention are all purchased from Nanjing Jieya Extrusion Equipment Co., Ltd.

[0091] Table 1 shows the components and contents of the polypropylene materials in Examples 1-4 and Comparative Examples 1-5.

[0092] The antioxidant 1010 in Table 1 is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], the TPPD is triphenylphosphonic acid diester, and the EBS is ethylene bisstearic acid amide.

[0093] Table 2 shows the properties of the materials in Examples 1-4 and Comparative Examples 1-5.

[0094] As shown in Tables 1 and 2, the low-odor rodent-proof extrusion-grade polypropylene materials in Examples 1-4 of the present invention have high Izod notched impact strength and high melt strength, and reduce the odor of the material while ensuring the rodent-proof rate, and also have flame retardant properties. The polypropylene used in Comparative Example 1 is homopolymer polypropylene, and the material prepared therefrom has poor mechanical properties and poor melt strength; in Comparative Example 2, only one special thread element, the TKD low-temperature shear block element, is used, and at the same feed rate, the processability and performance of the twin-screw extruder deteriorate; in Comparative Example 3, SFV spade-shaped thread elements and stretching elements are used, and the prepared material still cannot meet the use requirements; in Comparative Example 4, the processing temperature of the material in the twin-screw extruder is increased, and the increase in processing temperature will cause serious polypropylene chain scission, so the melt strength is sharply reduced, and the odor level increases due to the increase in temperature, which is not conducive to the application of the material; in Comparative Example 5, block copolymer polypropylene and homopolymer polypropylene with a high melt index are used for modification, and the obtained material has extremely poor performance.

[0095] The test standard for the melt index of the materials in Examples 1-4 and Comparative Examples 1-5 is "ASTM D1238", the test standard for the 23°C Izod notched impact strength is "ASTM D256", the test standard for the odor level is "Q / HR 0501028-2019", the test standard for the rodent-proof rate is "JBT 10696.10-2011", the test standard for flame retardancy is "UL94", and the strip length is 1.6 mm.

Claims

1. A low-odor rodent-proof extrusion-grade polypropylene material, characterized in that: The low-odor rodent-proof extrusion-grade polypropylene material is prepared by mixing polypropylene, a toughening agent, minerals, a flame retardant, a rodent-proof agent, an antioxidant and a lubricant, and then extruding the mixture through a twin-screw extruder; the low-odor rodent-proof extrusion-grade polypropylene material has a 230°C / 2.16kg melt index of 1-3g / min, and a 23°C Izod notched impact strength of 30-50kJ / m 2 , melt strength is 30000-100000Pa·s, odor level is 2-4, rodent resistance rate is 90-100%, and flame retardancy is V0; The twin-screw extruder is equipped with a special screw element; the components and their contents in the low-odor rodent-proof extrusion-grade polypropylene material are: Polypropylene: 40-58 parts by weight; Toughening agent: 10-20 parts by weight; Minerals: 10-20 parts by weight; Flame retardant: 15-25 parts by weight; Rodent repellent: 0.15-0.5 parts by weight; Antioxidant: 0.1-1 parts by weight; Lubricant: 0.1-1 parts by weight.

2. The low-odor rodent-proof extrusion-grade polypropylene material according to claim 1, characterized in that: The special threaded elements include SFV spade-shaped threaded elements, TKD low-temperature shear block elements and tensile elements. The inner diameters of the SFV spade-shaped threaded elements, the TKD low-temperature shear block elements and the tensile elements are all 30 mm.

3. The low-odor rodent-proof extrusion-grade polypropylene material according to claim 1, characterized in that: The SFV spade thread elements include SFV70 / 70 and SFVN70 / 20, the TKD low temperature shear block elements include TKD45° / 5 / 32, and the tensile elements include 192 / 48 and 192 / 48L.

4. The low-odor rodent-proof extrusion-grade polypropylene material according to claim 1, characterized in that: The polypropylene includes block copolymer polypropylene and random copolymer polypropylene, wherein the melt index of the block copolymer polypropylene at 230°C / 2.16kg is 3-10g / 10min, and the melt index of the random copolymer polypropylene at 230°C / 2.16kg is 0.1-2g / 10min.

5. The low-odor rodent-proof extrusion-grade polypropylene material according to claim 1, characterized in that: The toughening agent is one or more of linear low-density polyethylene and polyolefin elastomer.

6. The low-odor rodent-proof extrusion-grade polypropylene material according to claim 1, characterized in that: The rodent-proofing agent is compounded with aromatic plant oil and one or two of capsaicin or bitter compounds.

7. A method for preparing the low-odor rodent-proof extrusion-grade polypropylene material according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, mixing polypropylene, toughening agent, minerals, flame retardant, rodent repellent, antioxidant and lubricant in a high-speed mixer to obtain a mixture; Step 2: discharge the mixed material from the discharge port of a twin-screw extruder, extrude it through the twin-screw extruder, water-cool it at room temperature, and then naturally air-dry it to obtain the low-odor rodent-proof extrusion-grade polypropylene material.

8. The preparation method according to claim 7, characterized in that: The processing temperature of the twin-screw extruder in the step 2 is 170-190°C, which is divided into fourteen temperature zones, wherein the temperature of the first temperature zone is 180-190°C, the temperature of the second temperature zone is 180-190°C, the temperature of the third temperature zone is 180-190°C, the temperature of the fourth temperature zone is 180-190°C, the temperature of the fifth temperature zone is 170-180°C, the temperature of the sixth temperature zone is 170-180°C, the temperature of the seventh temperature zone is 170-180°C, the temperature of the eighth temperature zone is 160-170°C, the temperature of the ninth temperature zone is 160-170°C, the temperature of the tenth temperature zone is 160-170°C, the temperature of the eleventh temperature zone is 170-180°C, the temperature of the twelfth temperature zone is 180-190°C, the temperature of the thirteenth temperature zone is 180-190°C, and the temperature of the fourteenth temperature zone is 180-190°C.

9. The preparation method according to claim 7, characterized in that: The feeding rate of the twin-screw extruder in step 2 is 30-50kg / h.

10. An electrical material, characterized in that: The electrical material is prepared from the low-odor rodent-proof extrusion-grade polypropylene material according to any one of claims 1 to 6, and the electrical material comprises an outer layer of an electric wire, a cable or an electrical casing.

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