Low-smoke halogen-free material for B2ca high-flame-retardant high-flexibility cable and preparation method of low-smoke halogen-free material

Abstract

The invention relates to a low-smoke halogen-free material for a B2ca high-flame-retardant high-flexibility cable and a preparation method of the low-smoke halogen-free material. The raw materials comprise 30-50 parts of POE resin; 10 to 20 parts of metallocene polyethylene; 10 parts of a flame-retardant plasticizer; 10 to 20 parts of a flame retardant PPO; 50 to 100 parts of flame retardant phosphorus nitrogen; 50-100 parts of a flame retardant magnesium hydroxide; 0.3 to 0.5 part of an antioxidant; 15-20 parts of a shell forming agent; and 1 part of an auxiliary agent. The preparation method comprises the steps that all the raw material components are put into an internal mixer according to the proportion to be heated and pre-stirred, the temperature of the internal mixer is controlled to range from 170 DEG C to 180 DEG C, and the internal mixing time ranges from 15 min to 20 min; feeding the internally mixed and clustered micellar cones into a double-screw granulator for extruding and granulating, wherein the heating temperature of each section of the double-screw granulator is equally divided from 150 to 120 DEG C according to the number of heating sections; and extruding and granulating to obtain the material. The cable has the advantages of being flexible, easy to bend, good in insulativity, low in heat release amount and the like.

Description

Technical Field

[0001] The invention relates to the technical field of cable materials, and in particular to a low-smoke halogen-free material for a B2ca highly flame-retardant and highly flexible cable and a preparation method thereof. Background Art

[0002] Domestic low-smoke, halogen-free, flame-retardant polyolefin cable material product technology is becoming increasingly mature. Domestic polyolefin cable materials basically cover most of the materials required for all optoelectronic cables. Insulation and sheath materials required for bundled combustion of wires and cables are also common in the market, such as Wanma, Kaibo, Kingfa and other cable material manufacturers. GB 31247 was only formulated and implemented in 2014, and the market application end has only begun to gradually implement this standard in the past two years. The domestic technology and market environment are in the initial and gradual expansion stage. At present, the application end involves key projects such as subways and airports, and the designers have begun to quote the combustion classification specifications of GB 31247-2014.

[0003] At present, the cables that mainly apply the combustion classification standard of GB 31247 in China include: medium and low voltage transmission cables for up and down rail transit, medium and low voltage cables for high-speed rail and subway platform construction, railway signal transmission cables, medium and low voltage cables for key facilities such as airports, libraries, and government buildings, data cables exported to the EU that implement CPR B2ca and Cca, and indoor optical cables, etc.

[0004] For cables required by B2ca, due to the calculation logic of the number of cables in the detection method, the smaller the outer diameter of the cable, the more difficult it is to burn in the B2ca combustion test. Therefore, auxiliary structural designs such as filling, flame retardant tape, and oxygen isolation are added to the structural design of small-sized cables.

[0005] The problems with existing B2ca cable materials are:

[0006] 1.Flexibility research

[0007] Domestic applications are mainly power cables. Since the specific use scenarios of B2ca of domestic power cables are all fixed laying, they usually do not involve flexibility requirements. When they need to be used inside equipment, especially some scenarios require large bends, they cannot meet application requirements in terms of flexibility.

[0008] 2. Flame retardant research under flexibility

[0009] Usually, the softness and flame retardancy of polymer materials contradict each other. Generally speaking, the softer the polymer material, the worse the flame retardancy. For example, the cables involved in a project are small-sized cables with conductor cross-sections of 6 square meters and 35 square meters. In the B2ca combustion test, the test method makes the design of small-sized cables more difficult. In addition, the additional flexibility requirements put forward higher requirements for the difficulty of flame retardancy design, which cannot be met by existing technologies.

[0010] 3. Balance between insulation and flame retardancy of YJRY

[0011] The electrical insulation index of polymer materials is in conflict with the flame retardancy project. For example, the double-layer insulated wire in a certain project, model YJRY, refers to the standard IEC 60502.1. The optional materials for cross-linked insulation materials in the IEC 60502.1 standard are EPR, HEPR, and XLPE. None of these three materials require flame retardancy, and the standard does not specifically consider and design cross-linked low-smoke halogen-free insulation. The electrical performance test requirements specified in the standard, EPR\HEPE\XLPE must meet the volume resistivity ≥10^12Ω·m at the maximum conductor temperature of 90 degrees during normal operation. This indicator requirement is not for the application scenario to adapt, but the standard specifies that the corresponding material can meet the indicator requirement. The indicator requirements in the standard are very redundant, so for low-smoke halogen-free flame retardant materials, the standard test must be applied, which poses a great challenge to the balance between material insulation and flame retardancy.

[0012] Therefore, it is urgent to provide a low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cables and a preparation method thereof. Summary of the invention

[0013] The object of the present invention is to provide a low-smoke halogen-free material for a B2ca highly flame-retardant and highly flexible cable and a preparation method thereof.

[0014] In order to achieve the above object, the technical solution adopted by the present invention is:

[0015] A low-smoke halogen-free material for a B2ca highly flame-retardant and highly flexible cable, the raw materials of which include the following components in parts by weight:

[0016] POE resin 30-50 parts;

[0017] 10-20 parts of metallocene polyethylene;

[0018] 10 parts of flame retardant plasticizer;

[0019] Flame retardant PPO 10-20 parts;

[0020] Flame retardant phosphorus and nitrogen 50-100 parts;

[0021] Flame retardant magnesium hydroxide 50-100 parts;

[0022] Antioxidant 0.3-0.5 parts;

[0023] 15-20 parts of shell forming agent;

[0024] 1 part of additive.

[0025] Preferably, the raw materials include the following components in parts by weight:

[0026] POE resin 50 parts;

[0027] 10 parts of metallocene polyethylene;

[0028] 10 parts of flame retardant plasticizer;

[0029] Flame retardant PPO 10 parts;

[0030] Flame retardant phosphorus nitrogen 50 parts;

[0031] Flame retardant magnesium hydroxide 50 parts;

[0032] 0.5 parts of antioxidant;

[0033] 20 parts of shell forming agent;

[0034] 1 part of additive.

[0035] According to a further technical solution, the POE resin is POE resin DF740.

[0036] According to a further technical solution, the flame retardant plasticizer is a boron-based structural flame retardant plasticizer, such as boric acid dibutyl ester diethylene glycol phosphate, preferably boric acid dibutyl ester diethylene glycol phosphate P204.

[0037] According to a further technical solution, the flame retardant phosphorus and nitrogen are selected from piperazine pyrophosphate and melamine cyanurate blended in a mass ratio of 4:6, preferably piperazine pyrophosphate HF310 and melamine cyanurate 15N3.

[0038] In a further technical solution, the shell-forming agent is selected from aluminum magnesium silicate inorganic substances.

[0039] In a further technical solution, the antioxidant is selected from one or more combinations of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, dilauryl thiodipropionate, and tris(2,4-di-tert-butylphenyl) phosphite.

[0040] According to a further technical solution, the flame retardant magnesium hydroxide is selected from chemically produced ultrafine magnesium hydroxide with a particle size of 0.9-1.1 μm.

[0041] According to a further technical solution, the auxiliary agent is selected from α-olefin maleic anhydride copolymers.

[0042] Furthermore, the present invention also relates to a method for preparing a low-smoke halogen-free material for a B2ca highly flame-retardant and highly flexible cable, comprising:

[0043] Step 1: Place the raw material components in a mixer according to the proportion and heat them for pre-mixing for 1-2 minutes. The mixer temperature is controlled at 170-180°C and the mixing time is 15-20 minutes.

[0044] Step 2: Feed the kneaded gel mass into a twin-screw extruder for extrusion and material making. The heating temperature of each section of the twin-screw extruder is evenly divided from 150-120° C. according to the number of heating sections. After extrusion and granulation, a B2ca high-flame-retardant and high-flexible cable low-smoke and halogen-free material is obtained.

[0045] In the above scheme, the low-smoke halogen-free material for highly flame-retardant and highly flexible cables of the present invention can be applied to H07Z-K and YJRY cables specified in EN50525-3-41 and IEC 60502.1 standards.

[0046] Furthermore, the present invention also provides an application of a low-smoke halogen-free material for a B2ca highly flame-retardant and highly flexible cable in the field of equipment manufacturing.

[0047] In the above scheme, on the one hand, the application of the present invention is the cable inside the device, and some scenes require large bending, so high requirements are put forward in terms of flexibility. The softness and flame retardancy of polymer materials are contradictory. Generally speaking, the softer the polymer material, the worse the flame retardancy.

[0048] On the other hand, the cable involved in the present invention is a small-sized cable with a conductor cross-section of 6 square to 35 square. In the B1 combustion test, the test method makes the small-sized cables more difficult, and the additional flexibility requirements put forward higher requirements for the difficulty of flame-retardant design.

[0049] Therefore, in order to meet the flexibility requirements, boron-based structural flame retardant plasticizers are selected as plasticizers, supplemented by PPO and phosphorus-nitrogen flame retardant synergists. A smaller amount of flame retardant is required to achieve the flame retardant requirements of B2ca for cables.

[0050] Compared with the prior art, the advantages of the present invention are as follows:

[0051] 1. The present invention meets the softness requirements, can meet the application requirements of cables inside the equipment, achieves large curvature in specific scenarios, and has good flexibility.

[0052] 2. As a polymer material, the present invention can overcome the contradiction between softness and flame retardancy.

[0053] 3. The present invention can satisfy the balance between the insulation and flame retardancy of the material.

[0054] In summary, the present invention solves the problems in the prior art that the B2ca cable material is hard, difficult to bend, has a complex structural design, and has poor insulation. It has the advantages of being soft, easy to bend, having good insulation, and having low heat release, and meets the application requirements of B2ca with high flame retardancy and high flexibility. It also has controllable costs and good market commercial value. DETAILED DESCRIPTION

[0055] The present invention will be further described below in conjunction with embodiments:

[0056] The present invention will be described in detail below. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the techniques taught by the present invention without departing from the spirit and scope of the present invention.

[0057] The terms used herein are only for describing specific embodiments and are not intended to be limiting of the present invention. The terms "include", "including", "have", etc. used herein are all open terms, meaning including but not limited to.

[0058] The terms used herein generally have the ordinary meanings of each term used in the art, in the context of the present invention, and in the specific context, unless otherwise noted. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art regarding the description of the present invention.

[0059] Embodiment 1:

[0060] 1. Experimental Materials

[0061] POE resin (7256) 50 parts; metallocene polyethylene (3518) 10 parts; flame retardant plasticizer (boric acid dibutyl ester diethylene glycol phosphate) 10 parts; flame retardant PPO 10 parts, flame retardant phosphorus nitrogen (piperazine pyrophosphate, melamine cyanurate mixed ratio 4:6) 50 parts; flame retardant magnesium hydroxide (chemical ultrafine magnesium hydroxide A7) 50 parts; antioxidant (1010+DLTP) 0.5 parts; shelling agent (aluminum magnesium silicate z-373) 15 parts; auxiliary agent (alpha olefin maleic anhydride copolymer) 1 part.

[0062] 2. Preparation method:

[0063] a. Place the raw material components in a mixer according to the proportion and heat them for pre-mixing for 1 minute. The mixer temperature is controlled at 170-180°C and the mixing time is 15-20 minutes.

[0064] b. The kneaded rubber mass is directly fed into a twin-screw extruder for extrusion and material making. The heating temperature of each section of the twin-screw extruder is evenly divided from 150-120℃ according to the number of heating sections;

[0065] c. The finished products of extrusion are dried and packaged for storage.

[0066] Embodiment 2:

[0067] 1. Experimental Materials

[0068] POE resin (7256) 50 parts; metallocene polyethylene (3518) 10 parts; flame retardant plasticizer (boric acid distiller bis diethylene glycol phosphate) 10 parts; flame retardant PPO 10 parts, flame retardant phosphorus nitrogen (piperazine pyrophosphate, melamine cyanurate mixed ratio 4:6) 50 parts; flame retardant magnesium hydroxide (chemical ultrafine magnesium hydroxide A7) 50 parts; antioxidant (1010+DLTP) 0.5 parts; shelling agent (aluminum magnesium silicate z-373) 20 parts; auxiliary agent (alpha olefin maleic anhydride copolymer) 1 part.

[0069] 2. Preparation method

[0070] a. Place the raw material components in a mixer according to the proportion and heat them for pre-mixing for 1 minute. The mixer temperature is controlled at 170-180°C and the mixing time is 15-20 minutes.

[0071] b. The kneaded rubber mass is directly fed into a twin-screw extruder for extrusion and material making. The heating temperature of each section of the twin-screw extruder is evenly divided from 150-120℃ according to the number of heating sections;

[0072] c. The finished products of extrusion are dried and packaged for storage.

[0073] Embodiment 3:

[0074] 1. Experimental Materials

[0075] POE resin (DF740) 50 parts; metallocene polyethylene (SP0540) 10 parts; flame retardant plasticizer (boric acid dibutyl ester diethylene glycol phosphate) 10 parts; flame retardant PPO 10 parts, flame retardant phosphorus nitrogen (piperazine pyrophosphate, melamine cyanurate mixed ratio 4:6) 50 parts; flame retardant magnesium hydroxide (chemical ultrafine magnesium hydroxide A7) 50 parts; antioxidant (1010+DLTP) 0.5 parts; shelling agent (aluminum magnesium silicate z-373) 20 parts; auxiliary agent (alpha olefin maleic anhydride copolymer) 1 part.

[0076] 2. Preparation method

[0077] a. Place the raw material components in a mixer according to the proportion and heat them for pre-mixing for 1 minute. The mixer temperature is controlled at 170-180°C and the mixing time is 15-20 minutes.

[0078] b. The kneaded rubber mass is directly fed into a twin-screw extruder for extrusion and material making. The heating temperature of each section of the twin-screw extruder is evenly divided from 150-120℃ according to the number of heating sections;

[0079] c. The finished products of extrusion are dried and packaged for storage.

[0080] Embodiment 4:

[0081] 1. Experimental Materials

[0082] 50 parts of POE resin (DF740); 10 parts of metallocene polyethylene (4404); 10 parts of flame retardant plasticizer (boric acid dibutyl ester diethylene glycol phosphate); 15 parts of flame retardant PPO, 60 parts of flame retardant phosphorus and nitrogen (pyrophosphate piperazine HF310 and melamine cyanurate 15N3 mixed in a ratio of 4:6); 50 parts of flame retardant magnesium hydroxide (chemical ultrafine magnesium hydroxide A7); 0.5 parts of antioxidant (1010+DLTP); 20 parts of shelling agent (aluminum magnesium silicate z-373+z-351); 1 part of auxiliary agent (alpha olefin maleic anhydride copolymer).

[0083] 2. Preparation method

[0084] a. Place the raw material components in a mixer according to the proportion and heat them for pre-mixing for 1 minute. The mixer temperature is controlled at 170-180°C and the mixing time is 15-20 minutes.

[0085] b. The kneaded rubber mass is directly fed into a twin-screw extruder for extrusion and material making. The heating temperature of each section of the twin-screw extruder is evenly divided from 150-120℃ according to the number of heating sections;

[0086] c. The finished products of extrusion are dried and packaged for storage.

[0087] The B2ca high flame retardant and high flexibility cable low smoke zero halogen material prepared in the above Examples 1 to 4 was tested for softness with reference to H07Z-K and YJRY cables specified in EN50525-3-41 and IEC 60502.1 standards, and compared with the existing polyolefin elastomer low smoke zero halogen insulation material in the prior art, such as the grade DW-EH9029S (comparative example) produced by CGN High-tech Nuclear Materials Technology (Suzhou) Co., Ltd. The results are shown in Table 1:

[0088] Table 1 Performance test of low smoke zero halogen materials for B2ca high flame retardant and high flexible cables

[0089]

[0090] It can be seen from the data in Table 1 above that, compared with the existing B2ca low-smoke halogen-free material for highly flame-retardant and highly flexible cables in the prior art, the soft cable prepared by the present invention has the advantages of being soft, having a smaller rebound angle and being easy to bend, and having low heat release.

[0091] In summary, the present invention firstly uses boric acid dibutyl ester diethylene glycol phosphate through research, which provides flexibility while taking into account flame retardancy. Through the efficient compounding of flame retardant PPO, piperazine pyrophosphate HF310 and melamine cyanurate 15N3, the prepared soft cable has softness, passes the B2ca combustion test and has excellent insulation.

[0092] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cables, characterized by: Its raw materials include the following components in parts by weight: POE resin 30-50 parts; 10-20 parts of metallocene polyethylene; 10 parts of flame retardant plasticizer; Flame retardant PPO 10-20 parts; Flame retardant phosphorus and nitrogen 50-100 parts; Flame retardant magnesium hydroxide 50-100 parts; Antioxidant 0.3-0.5 parts; 15-20 parts of shell forming agent; 1 part of additive.

2. The low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cables according to claim 1, characterized in that: Its raw materials include the following components in parts by weight: POE resin 50 parts; 10 parts of metallocene polyethylene; 10 parts of flame retardant plasticizer; Flame retardant PPO 10 parts; Flame retardant phosphorus nitrogen 50 parts; Flame retardant magnesium hydroxide 50 parts; 0.5 parts of antioxidant; 20 parts of shell forming agent; 1 part of additive.

3. The low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The POE resin is POE resin DF740.

4. The low-smoke zero-halogen material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The flame retardant plasticizer is a boron-based structural flame retardant plasticizer.

5. The low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The flame retardant phosphorus and nitrogen are selected from piperazine pyrophosphate and melamine cyanurate mixed in a mass ratio of 4:

6.

6. The low-smoke zero-halogen material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The shell forming agent is selected from aluminum magnesium silicate inorganic substances.

7. The low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The antioxidant is selected from one or more combinations of tetrakis[β-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, dilauryl thiodipropionate, and tris(2, 4-di-tert-butylphenyl) phosphite.

8. The low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The flame retardant magnesium hydroxide is selected from chemically produced ultrafine magnesium hydroxide, and the particle size is 0.9-1.1 μm.

9. The low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cable according to claim 1, characterized in that: The auxiliary agent is selected from alpha olefin maleic anhydride copolymers.

10. A method for preparing a low-smoke halogen-free material for a B2ca highly flame-retardant and highly flexible cable, characterized in that: Used for preparing the low-smoke halogen-free material for B2ca highly flame-retardant and highly flexible cables according to any one of claims 1 to 9, the preparation method comprising: Step 1: Place the raw material components in a mixer according to the proportion and heat them for pre-mixing for 1-2 minutes. The mixer temperature is controlled at 170-180°C and the mixing time is 15-20 minutes. Step 2: Feed the kneaded gel mass into a twin-screw extruder for extrusion and material making. The heating temperature of each section of the twin-screw extruder is evenly divided from 150-120° C. according to the number of heating sections. After extrusion and granulation, a B2ca high-flame-retardant and high-flexible cable low-smoke and halogen-free material is obtained.

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