Composite polypropylene insulating material, its preparation method and application in preparation of low-voltage cable in cabin of flying body

Abstract

The application discloses a kind of composite polypropylene insulating materials and its preparation method and application in preparation flying body cabin low pressure cable.The composite polypropylene insulating material comprises the following components by weight: polypropylene-containing resin composition 30-100 parts;Compatibilizer 0-10 parts;Surface modifier 0.5-1.5 parts;Nitrogen-based flame retardant 15-25 parts;Phosphorus-based flame retardant 10-15 parts;Smoke suppressant 0-5 parts;Antioxidant 0.5-1 part.The composite polypropylene insulating material described in the application has excellent halogen-free flame retardant performance, low smoke, low toxicity characteristics, and excellent high and low temperature resistance;It can meet the requirements of smoke density and smoke toxicity of cable material in CCAR-25-R4 standard, and also meets the requirements of C-class temperature resistance in automobile wire ISO 19642 standard;It is a kind of composite polypropylene insulating material with very excellent comprehensive performance, suitable for flying body cabin low pressure cable insulating layer.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, specifically to a composite polypropylene insulating material, its preparation method, and its application in the preparation of low-voltage cables for aircraft cabins. Background Technology

[0002] Currently, the insulation materials for communication cables on the market are mainly PE, PP, XLPO, PVC, or fluorinated materials. With the increasing emphasis on environmental protection and industry development trends, PVC and fluorinated materials will gradually be replaced. Ordinary PE materials do not meet the temperature resistance requirements of Class C in the ISO 19642 standard for automotive wiring harnesses. XLPE requires the addition of cross-linking agents, and residual components lead to high dielectric loss. Furthermore, it requires an irradiation process, which prolongs the production cycle and increases production costs. PP materials are not widely used in cables, and the flame retardant properties of PP products from different manufacturers vary significantly.

[0003] Chinese patent application document (publication number: CN103443872A) discloses a cable. The composition involved in this patent contains halogenated products and does not mention the corresponding temperature resistance requirements. It cannot meet the requirements for halogen-free materials, smoke density, smoke toxicity, and temperature resistance in aircraft cabins. Chinese patent application document (publication number: CN115926304A) discloses an insulating material for silane self-crosslinking cables and its preparation method. The processing of this patent is relatively complex, with a high specific gravity, and it does not mention test results for smoke density and smoke toxicity. It cannot be determined whether the material meets the requirements for low-altitude aircraft materials. Chinese patent application document (publication number: CN117402497A) discloses a long-term high-temperature resistant silicone rubber, its preparation method, and its applications. This patent mentions its application in aerospace cables but does not mention related requirements for flame retardancy, smoke density, and smoke toxicity. Furthermore, it requires crosslinking, making manufacturing highly demanding. It cannot be determined whether this patent meets the relevant requirements of CCAR-25-R4.

[0004] In summary, there are currently few existing technologies related to low-voltage cable insulation materials in aircraft cabins. Therefore, this paper proposes a technology with advantages such as high flame retardancy, high temperature resistance, low smoke density, and low smoke toxicity, which has broad application prospects in the field of low-voltage cable insulation, especially in the field of low-voltage cable insulation in aircraft cabins. Summary of the Invention

[0005] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a composite polypropylene insulation material, a method for preparing the same, and its application in the preparation of low-voltage cables in the cabin of an aircraft.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention first provides a composite polypropylene insulating material, which comprises the following components in parts by weight: 30-100 parts of a polypropylene resin composition; 0-10 parts of a compatibilizer; 0.5-1.5 parts of a surface modifier; 15-25 parts of a nitrogen-based flame retardant; 10-15 parts of a phosphorus-based flame retardant; 0-5 parts of a smoke suppressant; and 0.5-1 parts of an antioxidant.

[0008] Preferably, the polypropylene-containing resin composition comprises polypropylene resin, SEBS resin, elastomer resin, and PPO resin.

[0009] Preferably, the weight parts of polypropylene resin, SEBS resin, elastomer resin, and PPO resin are as follows:

[0010] 30-55 parts polypropylene resin; 1-15 parts SEBS resin; 1-15 parts elastomer resin; 1-10 parts PPO resin.

[0011] More preferably, the weight parts of polypropylene resin, SEBS resin, elastomer resin, and PPO resin are as follows:

[0012] 30-40 parts polypropylene resin; 5-15 parts SEBS resin; 5-15 parts elastomer resin; 5-10 parts PPO resin.

[0013] Preferably, the composite polypropylene insulating material comprises the following components in parts by weight: 30-55 parts polypropylene resin; 1-15 parts SEBS resin; 1-15 parts elastomer resin; 1-10 parts PPO resin; 5-10 parts compatibilizer; 0.5-1.5 parts surface modifier; 15-25 parts nitrogen-based flame retardant; 10-15 parts phosphorus-based flame retardant; 0-5 parts smoke suppressant; and 0.5-1 part antioxidant.

[0014] More preferably, the composite polypropylene insulating material comprises the following components in parts by weight: 30-40 parts polypropylene resin; 5-15 parts SEBS resin; 5-15 parts elastomer resin; 5-10 parts PPO resin; 0-10 parts compatibilizer; 1-1.5 parts surface modifier; 15-25 parts nitrogen-based flame retardant; 10-15 parts phosphorus-based flame retardant; 3-5 parts smoke suppressant; and 0.5-1 part antioxidant.

[0015] Preferably, the elastomer resin is selected from at least one of ethylene-propylene copolymer, ethylene-octene copolymer, and ethylene-vinyl acetate copolymer.

[0016] Most preferably, and even more preferably, the elastomer resin is an ethylene-octene copolymer.

[0017] Preferably, the compatibilizer is selected from at least one of maleic anhydride-grafted polypropylene, maleic anhydride-grafted ethylene-vinyl acetate copolymer, maleic anhydride-grafted ethylene-octene copolymer, and maleic anhydride-grafted ethylene butyl acrylate.

[0018] Most preferably, the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate.

[0019] Preferably, the surface modifier is selected from at least one of octamethylcyclotetrasiloxane, propyltrimethylsiloxane, and isopropyltris(dioctylpyrophosphoryloxy)titanate.

[0020] Most preferably, the surface modifier is composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyltris(dioctylpyrophosphoryloxy)titanate.

[0021] More preferably, the weight ratio of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyltris(dioctylpyrophosphoryloxy)titanate is 1-3:1-3:2-4.

[0022] Most preferably, the weight ratio of octamethylcyclotetrasiloxane, propyltrimethylsiloxane, and isopropyltris(dioctylpyrophosphoryloxy)titanate is 3:2:2.

[0023] The inventors made a surprising discovery during their research: the surface modifier of this invention has a significant impact on the smoke density of the prepared composite polypropylene insulation material. The composite polypropylene insulation material prepared using a surface modifier composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane, and isopropyltris(dioctylpyrophosphate)titanate has a significantly lower smoke density than the composite polypropylene insulation material prepared using only octamethylcyclotetrasiloxane, propyltrimethylsiloxane, or isopropyltris(dioctylpyrophosphate)titanate as a surface modifier. Furthermore, using all three components—octamethylcyclotetrasiloxane, propyltrimethylsiloxane, and isopropyltris(dioctylpyrophosphate)titanate—as surface modifiers can synergistically reduce the smoke density of the prepared composite polypropylene insulation material.

[0024] Preferably, the nitrogen-based flame retardant is selected from at least one of melamine cyanurate, melamine pyrophosphate, and melamine polyphosphate.

[0025] Most preferably, the nitrogen-based flame retardant is melamine cyanurate.

[0026] Preferably, the phosphorus-based flame retardant is selected from at least one of diethylaluminum hypophosphite, aluminum hypophosphite, piperazine pyrophosphate, and polyphosphate.

[0027] Most preferably, the phosphorus-based flame retardant is aluminum hypophosphite.

[0028] Preferably, the smoke suppressant is selected from at least one of aluminum hydroxide, magnesium hydroxide, zinc borate and montmorillonite.

[0029] Most preferably, the smoke suppressant is montmorillonite.

[0030] Preferably, the antioxidant is selected from at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0031] More preferably, the hindered phenolic antioxidant is selected from at least one of antioxidants 245, 264, 300, 702, 703, 1010, 1024, B215, B225, B900, B911, DLTDP, and DSTDP.

[0032] More preferably, the phosphite antioxidant is selected from at least one of antioxidants 168, 626 and P-EPQ.

[0033] More preferably, the antioxidant is a compound of DSTDP:168:1024 in a mass ratio of 3:1.5:1.

[0034] The present invention also provides a method for preparing the above-mentioned composite polypropylene insulating material, which includes the following steps:

[0035] A surface modifier was added to a polypropylene-containing resin composition by spraying. After spraying, the mixture was stirred evenly to obtain mixture A.

[0036] Antioxidant, smoke suppressant, phosphorus flame retardant and nitrogen flame retardant are mixed evenly to obtain mixture B;

[0037] Mixture A and mixture B thoroughly to obtain mixture C;

[0038] The mixture C is extruded and granulated using a twin-screw extruder to obtain the composite polypropylene insulation material.

[0039] The present invention also provides an application of the above-mentioned composite polypropylene insulating material in the preparation of low-voltage cables inside the aircraft cabin.

[0040] Beneficial Effects: This invention provides a novel composite polypropylene insulation material with excellent halogen-free flame retardant properties, low smoke and low toxicity, as well as excellent high and low temperature resistance. It meets the requirements of CCAR-25-R4 standard for smoke density and smoke toxicity of cable materials, and also meets the Class C temperature resistance requirements of ISO 19642 standard for automotive wiring. It is a composite polypropylene insulation material with excellent comprehensive performance, suitable for use as an insulation layer for low-voltage cables in aircraft cabins. In addition, the preparation process of the composite polypropylene insulation material described in this invention is simple and worthy of widespread application. Detailed Implementation

[0041] The present invention will be further explained below with reference to specific embodiments, but the embodiments do not limit the present invention in any way.

[0042] In the following embodiments, the polypropylene resin used is Z30S polypropylene from Sinopec; the SEBS resin used is SEBS 1659 from Kraton; the ethylene-octene copolymer used is ethylene-octene 8150 from Dow Chemical; the PPO resin used is PPO 040C from Bluestar Chemical; and the maleic anhydride-grafted ethylene butyl acrylate used is BA3210 from Arkema. Other unspecified raw materials are conventionally available to those skilled in the art.

[0043] Example 1: Preparation of Composite Polypropylene Insulation Material

[0044] Raw material composition by weight: 35 parts polypropylene resin; 10 parts SEBS resin; 10 parts elastomer resin; 10 parts PPO resin; 5 parts compatibilizer; 1 part surface modifier; 15 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0045] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0046] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0047] The surface modifier is composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyltris(dioctylpyrophosphoryloxy)titanate in a weight ratio of 3:2:2.

[0048] Preparation method of composite polypropylene insulation material:

[0049] (1) The surface modifier is added to the mixed resin by spraying. After spraying, the mixture is stirred for 3 minutes to obtain mixture A. The mixed resin refers to a mixture of polypropylene resin, SEBS resin, elastomer resin and PPO resin.

[0050] (2) Stir the antioxidant, smoke suppressant, phosphorus flame retardant and nitrogen flame retardant for 5 minutes to obtain mixture B;

[0051] (3) Stir mixture A and mixture B for 5 minutes to obtain mixture C;

[0052] (4) The mixture C is extruded and granulated by a twin-screw extruder to obtain the composite polypropylene insulation material.

[0053] Example 2: Preparation of Composite Polypropylene Insulation Material

[0054] Raw material composition by weight: 35 parts polypropylene resin; 15 parts SEBS resin; 5 parts elastomer resin; 10 parts PPO resin; 5 parts compatibilizer; 1.5 parts surface modifier; 20 parts nitrogen-based flame retardant; 10 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0055] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0056] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0057] The surface modifier is composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyltris(dioctylpyrophosphoryloxy)titanate in a weight ratio of 3:2:2.

[0058] The preparation method of the composite polypropylene insulation material is the same as in Example 1.

[0059] Example 3: Preparation of Composite Polypropylene Insulation Material

[0060] Raw material composition by weight: 30 parts polypropylene resin; 10 parts SEBS resin; 15 parts elastomer resin; 5 parts PPO resin; 5 parts compatibilizer; 0.5 parts surface modifier; 20 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0061] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0062] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0063] The surface modifier is composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyltris(dioctylpyrophosphoryloxy)titanate in a weight ratio of 3:2:2.

[0064] The preparation method of the composite polypropylene insulation material is the same as in Example 1.

[0065] Example 4: Preparation of Composite Polypropylene Insulation Material

[0066] Raw material composition by weight: 40 parts polypropylene resin; 5 parts SEBS resin; 10 parts elastomer resin; 5 parts PPO resin; 10 parts compatibilizer; 1.2 parts surface modifier; 20 parts nitrogen-based flame retardant; 10 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0067] Raw material composition by weight: 35 parts polypropylene resin; 15 parts SEBS resin; 5 parts elastomer resin; 10 parts PPO resin; 5 parts compatibilizer; 1.5 parts surface modifier; 20 parts nitrogen-based flame retardant; 10 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0068] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0069] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0070] The surface modifier is composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyltris(dioctylpyrophosphoryloxy)titanate in a weight ratio of 3:2:2.

[0071] The preparation method of the composite polypropylene insulation material is the same as in Example 1.

[0072] Example 5: Preparation of Composite Polypropylene Insulation Material

[0073] Raw material composition by weight: 35 parts polypropylene resin; 10 parts SEBS resin; 10 parts elastomer resin; 10 parts PPO resin; 5 parts compatibilizer; 1 part surface modifier; 15 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0074] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0075] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0076] The surface modifier is octamethylcyclotetrasiloxane.

[0077] Preparation method of composite polypropylene insulation material: same as in Example 1.

[0078] The difference between Example 5 and Example 1 is that the surface modifier used is only a single octamethylcyclotetrasiloxane.

[0079] Example 6: Preparation of Composite Polypropylene Insulation Material

[0080] Raw material composition by weight: 35 parts polypropylene resin; 10 parts SEBS resin; 10 parts elastomer resin; 10 parts PPO resin; 5 parts compatibilizer; 1 part surface modifier; 15 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0081] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0082] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0083] The surface modifier is propyltrimethylsiloxane.

[0084] Preparation method of composite polypropylene insulation material: same as in Example 1.

[0085] The difference between Example 6 and Example 1 is that the surface modifier used is only propyltrimethylsiloxane.

[0086] Example 7: Preparation of Composite Polypropylene Insulation Material

[0087] Raw material composition by weight: 35 parts polypropylene resin; 10 parts SEBS resin; 10 parts elastomer resin; 10 parts PPO resin; 5 parts compatibilizer; 1 part surface modifier; 15 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0088] The elastomer resin is an ethylene-octene copolymer; the compatibilizer is maleic anhydride-grafted ethylene butyl acrylate; the nitrogen-based flame retardant is melamine cyanurate; the phosphorus-based flame retardant is aluminum hypophosphite; and the smoke suppressant is montmorillonite.

[0089] The antioxidant is composed of DSTDP, 168 and 1024 in a mass ratio of 3:1.5:1;

[0090] The surface modifier is isopropyltris(dioctylpyrophosphate)titanate.

[0091] Preparation method of composite polypropylene insulation material: same as in Example 1.

[0092] The difference between Example 7 and Example 1 is that the surface modifier used is only a single isopropyltris(dioctylpyrophosphate) titanate.

[0093] Comparative Example 1: Preparation of Composite Polypropylene Insulation Material

[0094] Raw material composition by weight: 35 parts polypropylene resin; 10 parts SEBS resin; 10 parts elastomer resin; 5 parts compatibilizer; 1 part surface modifier; 25 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0095] Preparation method: Refer to the preparation method described in Example 1.

[0096] The difference between Comparative Example 1 and Example 1 is that no PPO resin was added.

[0097] Comparative Example 2: Preparation of Composite Polypropylene Insulation Material

[0098] Raw material composition by weight: 35 parts polypropylene resin; 10 parts SEBS resin; 10 parts elastomer resin; 10 parts PPO resin; 1 part surface modifier; 5 parts compatibilizer; 15 parts nitrogen-based flame retardant; 20 parts phosphorus-based flame retardant; 0.8 parts antioxidant.

[0099] Preparation method: Refer to the preparation method described in Example 1.

[0100] The difference between Comparative Example 2 and Example 1 is that no smoke suppressant was added.

[0101] Comparative Example 3: Preparation of Composite Polypropylene Insulation Material

[0102] Raw material composition by weight: 55 parts polypropylene resin; 10 parts PPO resin; 5 parts compatibilizer; 1 part surface modifier; 15 parts nitrogen-based flame retardant; 15 parts phosphorus-based flame retardant; 5 parts smoke suppressant; 0.8 parts antioxidant.

[0103] Preparation method: Refer to the preparation method described in Example 1.

[0104] The difference between Comparative Example 3 and Example 1 is that SEBS resin and elastomer resin are not added; only polypropylene resin and PPO resin are used instead.

[0105] Table 1. Performance test results of composite polypropylene insulation materials

[0106]

[0107]

[0108] In Table 1, the -40℃ low-temperature winding, 125℃ / 3000h long-term thermal aging and 150℃ / 240h short-term thermal aging tests were conducted according to the requirements of ISO 19642 standard; the 60° flame retardancy, smoke density and smoke toxicity were tested according to the relevant requirements for cables in CCAR-25-R4 standard.

[0109] As can be seen from the experimental results in Table 1, the composite polypropylene insulation materials prepared in Examples 1 to 7 all meet the requirements of ISO 19642 and CCAR-25-R4 standards in terms of flame retardancy, high and low temperature resistance, smoke density, and smoke toxicity; and can meet the requirements of low-voltage cables in the flight cabin.

[0110] Table 1 shows that the composite polypropylene insulation material prepared in Comparative Example 1 fails to meet the standard requirements for flame retardancy and smoke toxicity; the composite polypropylene insulation material prepared in Comparative Example 3 fails to meet the standard requirements for low-temperature resistance. Therefore, the selection of resin in this invention is crucial. A composite polypropylene insulation material prepared by simultaneously using a resin combination consisting of four resins—polypropylene resin, SEBS resin, elastomer resin, and PPO resin—is necessary to ensure that its flame retardancy, high and low temperature resistance, smoke density, and smoke toxicity all meet the standard requirements, and that the prepared composite polypropylene insulation material satisfies the requirements for low-voltage cables inside the aircraft cabin.

[0111] The experimental results in Table 1 also show that the smoke density of the composite polypropylene insulation material prepared in Example 1 is significantly lower than that of the composite polypropylene insulation materials prepared in Examples 5-7. This indicates that the surface modifier of the present invention has a significant impact on the smoke density of the prepared composite polypropylene insulation material. The composite polypropylene insulation material prepared using a surface modifier composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane, and isopropyltris(dioctylpyrophosphate)titanate has a significantly lower smoke density than the composite polypropylene insulation material prepared using only octamethylcyclotetrasiloxane, propyltrimethylsiloxane, or isopropyltris(dioctylpyrophosphate)titanate as a surface modifier. Simultaneously using three components—octamethylcyclotetrasiloxane, propyltrimethylsiloxane, and isopropyltris(dioctylpyrophosphate)titanate—as surface modifiers can synergistically reduce the smoke density of the prepared composite polypropylene insulation material.

Claims

1. A composite polypropylene insulation material, characterized in that, The composition comprises the following components by weight: polypropylene-containing resin composition 30-100 parts; compatibilizer 5-10 parts; surface modifier 0.5-1.5 parts; nitrogen-based flame retardant 15-25 parts; phosphorus-based flame retardant 10-15 parts; smoke suppressant 3-5 parts; antioxidant 0.5-1 part; The polypropylene-containing resin composition comprises polypropylene resin, SEBS resin, elastomer resin and PPO resin; the weight parts of the polypropylene resin, SEBS resin, elastomer resin and PPO resin are respectively: polypropylene resin 30-55 parts; SEBS resin 1-15 parts; elastomer resin 1-15 parts; PPO resin 1-10 parts; The elastomer resin is selected from at least one of ethylene-propylene copolymer, ethylene-octene copolymer and ethylene-vinyl acetate copolymer; The surface modifier is composed of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyl tri(dioctyl pyrophosphoryloxy) titanate; the weight ratio of octamethylcyclotetrasiloxane, propyltrimethylsiloxane and isopropyl tri(dioctyl pyrophosphoryloxy) titanate is 1-3: 1-3: 2-4; The compatibilizer is selected from at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-vinyl acetate copolymer, maleic anhydride grafted ethylene-octene copolymer and maleic anhydride grafted ethylene butyl acrylate.

2. The composite polypropylene insulation material of claim 1, wherein, The nitrogen-based flame retardant is selected from at least one of melamine cyanurate, melamine pyrophosphate and melamine polyphosphate.

3. The composite polypropylene insulation material of claim 1, wherein, The phosphorus-based flame retardant is selected from at least one of aluminum diethyl phosphinate, aluminum phosphinate, piperazine pyrophosphate and polyphosphate.

4. The composite polypropylene insulation material of claim 1, wherein, The smoke suppressant is selected from at least one of aluminum hydroxide, magnesium hydroxide, zinc borate and montmorillonite.

5. The composite polypropylene insulation material of claim 1, wherein, The antioxidant is selected from at least one of hindered phenolic antioxidant and phosphite antioxidant.

6. A process for the production of the composite polypropylene insulation material according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: The surface modifier is added to the polypropylene-containing resin composition by spraying, and the mixture is stirred uniformly after spraying to obtain mixture A; The antioxidant, smoke suppressant, phosphorus-based flame retardant and nitrogen-based flame retardant are stirred uniformly to obtain mixture B; Mixture A and mixture B are stirred uniformly to obtain mixture C; Mixture C is extruded and granulated by a double-screw extruder to obtain the composite polypropylene insulating material.

7. Use of the composite polypropylene insulating material according to any one of claims 1-5 in the preparation of low-pressure cables in the cabin of a flying object.

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