CN101735546A - High flame-retardant and high heat-resisting halogen-free expansion type fire-resistant cable material and preparation method thereof - Google Patents

Abstract

The invention relates to a highly flame-resistant, high-heat-resistant, halogen-free intumescent flame-retardant cable material and a preparation method thereof. In order to improve the problem of water precipitation of the cable material during processing and improve the mechanical properties at the same time, the present invention uses polyolefin material as the matrix and an intumescent flame retardant at the same time. The components by weight of the cable material are as follows: a) matrix resin 100; including: SEBS, ethylene-vinyl acetate copolymer, ethylene-propylene-butene terpolymer, polypropylene, high-density polyethylene, ethylene-octene Copolymer; b) flame retardant 60-80, including: ammonium polyphosphate type II, pentaerythritol, melamine; c) lubricant 2; d) antioxidant 1. Mix the above components evenly on a double-roller mill, the roller temperature is 190±5°C, and the mixing time is 30±5min, then press on a flat vulcanizer at 190±5°C, cold press, and release the mold. The cable material of the invention has high flame-retarding performance, the tensile strength reaches 12-16MPa, and the elongation at break reaches 400-500%. At the same time, the problem of material precipitation when meeting water is also improved.

Description

A high flame-retardant, high-heat-resistant, halogen-free intumescent flame-retardant cable material and its preparation method

Technical field:

The invention relates to a flame-retardant cable sheathing material and an insulating material with polyolefin as a matrix resin, in particular to a formulation of a halogen-free flame-retardant cable material.

Background technique:

With the development of wire and cable technology, high performance, environmental protection, and flame retardancy are the development direction of wire and cable materials. Following the RoHS directive and WEEE directive, the European Union has launched the EuP directive, namely the "Ecological Design of Energy-Using Products Directive". It is the third environmental protection directive for electronic and electrical products. According to the directive, specific implementation rules for related products were successively launched from 2007 to 2010. The EuP directive requires that certain harmful substances including halogens be prohibited for wire and cable products entering the EU market. This requires that the green manufacturing of wire and cable companies must start from raw materials, especially wire and cable rubber. The development and production of halogen-free flame-retardant cable materials that comply with the EuP directive will have far-reaching significance for the industrial structure adjustment and technological progress of my country's wire and cable industry, and for the technical barriers of the EU EuP directive.

At present, people usually add inorganic flame retardants Mg(OH) ₂ and Al(OH) ₃ and flame retardant synergist red phosphorus to the matrix to prepare halogen-free flame-retardant cable materials. However, because red phosphorus is easy to produce highly toxic phosphine gas, and red phosphorus dust is easy to explode, therefore, red phosphorus must undergo surface treatment before it can be used safely and effectively. In addition, the inherent purple color of red phosphorus greatly limits the application of cable materials containing red phosphorus. Moreover, the flame-retardant cable material containing red phosphorus will emit a large amount of pungent odor and a large amount of smoke during the production process and when it is burned. Therefore, it is imperative to prepare white cable materials without red phosphorus.

Intumescent flame retardant is a new type of flame retardant, which has the advantages of non-toxicity, environmental friendliness, and low smoke emission. It is one of the most promising ways to realize the preparation of high-performance halogen-free flame-retardant polymer materials. "High Flame-Retardant, High-Temperature, Low-Smoke, Halogen-Free Cable Sheathing Material and Its Processing Technology" (Patent Application No. 200510036319.0) discloses a formulation and processing technology of a low-smoke, halogen-free, flame-retardant cable material with high temperature resistance. "Halogen-free intumescent flame-retardant cable material and its prepared environment-friendly cable" (patent application number 200710028621.0) discloses a halogen-free intumescent flame-retardant cable material and its production method as well as an environment-friendly anti-rodent and ant-proof cable prepared. However, it cannot meet the requirements of high-performance cables in some aspects, and there are mainly two shortcomings: (1) The intumescent flame retardant has its fatal disadvantages, such as easy moisture absorption, and severe precipitation when it meets water. It becomes sticky when it meets water during processing, and its appearance is not good. And the problem of water precipitation is very difficult to solve; (2) The addition of intumescent flame retardants to the cable material greatly reduces the mechanical properties of the material, especially the tensile strength, which is usually difficult to exceed 12MPa. Therefore improving this technical problem is the direction of the trend.

Invention content:

In order to avoid the deficiencies of the prior art, improve the problem of water precipitation of the cable material during processing, and improve the mechanical properties of the material, the present invention adopts polyolefin material as the matrix, and adopts a new type of intumescent flame retardant as the flame retardant of the matrix. Flame-retardant, thereby providing a high flame-retardant, high-heat-resistant, halogen-free flame-retardant cable sheathing material and a preparation method of insulating material.

The base resin of a high flame-retardant, high-temperature-resistant, halogen-free intumescent cable compound of the present invention is SEBS, ethylene-vinyl acetate copolymer (EVA), ethylene-propylene-butene terpolymer, polypropylene (PP) ), ethylene-octene copolymer (POE), high-density polyethylene (HDPE), maleic anhydride grafted SEBS and polyacrylimide resin blends, using such a compounding matrix, can be more Greatly improve the mechanical properties, flame retardancy and heat resistance of cable materials.

The flame retardant used in the present invention is a modified halogen-free intumescent flame retardant, which is ammonium polyphosphate II type (APP, whose molecular formula is (NH ₄ PO ₃ )n), pentaerythritol (PER, whose molecular formula is C( CH ₂ OH) ₄ ), melamine (MEL, its molecular formula is C ₃ H ₆ N ₆ ), or a mixture of these flame retardants. The structural formulas of these three flame retardants are shown below.

Ammonium polyphosphate Pentaerythritol

Melamine

Structural formulas of ammonium polyphosphate, pentaerythritol, and melamine flame retardants

The antioxidant that the present invention adopts is main antioxidant, three (2,4 - di-tert-butylphenyl) phosphite (antioxidant 168) is a secondary antioxidant, and the weight ratio of the primary antioxidant to the secondary antioxidant is 3:1.

The lubricant used in the present invention is one or a mixture of at least two of stearic acid, zinc stearate and oleic acid amide.

The components by weight of the halogen-free intumescent cable material of the present invention are as follows:

a) Matrix resin 100

Among them: SEBS 20～50

Ethylene-vinyl acetate copolymer 15～20

Ethylene-propylene-butene terpolymer 15～20

Polypropylene 15～20

High-density polyethylene 0～5

Ethylene-octene copolymer 0～5

Maleic anhydride grafted SEBS 2.5～5

Polyacrylimide 2.5～5

b) Flame retardant 60～80

Among them: ammonium polyphosphate type II 30～60

Pentaerythritol 10～15

Melamine 10～15

c) Lubricant 2

d) Antioxidant 1010 0.75

Antioxidant 168 0.25

In order to solve the compatibility between the intumescent flame retardant and the resin matrix and achieve the purpose of improving the comprehensive performance of the composite material, the intumescent flame retardant used in the present invention is an intumescent flame retardant modified by a surface modifier. agent. The modifying agent includes: stearic acid surfactant, titanate coupling agent, silane coupling agent surface modifying agent, etc., and the dosage is between 0.5% and 3.0% by weight of the intumescent flame retardant. Surface modification methods are divided into wet modification and dry modification. The wet treatment process is suitable for water-soluble modifiers. Add 0.5% to 3.0% modifiers in water at a temperature of 78°C (relative to the expansion Type flame retardant weight), after the modifier is completely dissolved, then add intumescent flame retardant, stir well, then filter, wash, dry the filter cake, and then pulverize to obtain modified intumescent flame retardant. The dry treatment process is suitable for water-insoluble modifiers. Heat the mixer to 70°C, and then add the intumescent flame retardant together with 0.5% to 3.0% modifier (relative to the weight of the intumescent flame retardant) Put it into the blender, after stirring, discharge. Both can achieve the intended purpose.

The ammonium polyphosphate used in the present invention is type II ammonium polyphosphate, its crystallinity is relatively high, greater than 1000, and its solubility in water is small, which can greatly improve the problem of precipitation of cable materials in water during processing.

The purpose of adding the maleic anhydride grafted SEBS in the present invention is to improve the compatibility between the intumescent flame retardant and the polymer matrix and to improve the precipitation of the cable material in water during processing. One end of this compatibilizer has good compatibility with the polymer SEBS, and the other end is firmly combined with the intumescent flame retardant, so that the mechanical properties of the cable material and the precipitation of the intumescent flame retardant can be improved. question.

The purpose of adding polyacrylimide in the present invention is to improve the mechanical properties of the cable material. One end of this material has very good compatibility with the polymer polypropylene, and the other end is closely connected with the -NH2 group in the intumescent flame retardant. The interfacial bonding between the polymer and the flame retardant is strengthened, thereby improving the mechanical properties of the material.

In order to characterize the problem of precipitation of intumescent flame retardants in water, the present invention also adopts the following method to judge. The main method is to place the cable material sample containing intumescent flame retardant in water at 90°C to see its solubility in water. If it dissolves, there will be a white powdery substance in the water, and it is dried in an oven. Infrared analysis shows that the white powdery substance dissolved in water is an intumescent flame retardant, and the solubility of the intumescent flame retardant in water can be obtained through calculation.

The invention provides a high-flame-resistance, high-heat-resistance, halogen-free intumescent flame-retardant cable material, which uses an intumescent flame-retardant flame-retardant polyolefin polymer to prepare a high-performance halogen-free flame-retardant cable material. The obtained cable material has relatively excellent flame retardancy and temperature resistance. The vertical burning 1.6mm test can reach the FV-0 level, the oxygen index can reach 30-35%, a single electronic wire of 0.6mm can pass the VW-1 test, and the temperature resistance level can reach 105°C. The tensile strength can reach 12-16MPa, and the elongation at break can reach 400-500%. There is no precipitation in water, and it can be used together with color masterbatch to produce cables of various colors. It has excellent processing performance and is mainly used in the production of mobile phone charger cables, electronic cables, power cables, network cables and USB cables.

Existing plastic processing equipment can be used to produce this kind of flame-retardant cable material, and the process route is simple and easy to operate. The process route is as follows: firstly, the materials are mixed evenly on the double-roll mill, the temperature of the rollers is 190±5°C, and the mixing time is 30±5min. Then press on a flat vulcanizing machine at 190±5°C, cold press, and release the mold. In order to ensure the comparability of each performance parameter in the implementation examples, uniformly made samples with a thickness of 2 mm were tested according to the national standard GB/T 1040-92 to test the mechanical properties of the composite material. The horizontal and vertical combustion test is tested according to the national standard GB/T 2408-1996, and the oxygen index is tested according to the national standard GB 2406-93.

In the present invention, SEBS and PP are selected as the main substrate, and the intumescent flame retardant is used as the flame retardant of the substrate, so the prepared cable material has high flame retardancy, can pass the UL 94FV-0 grade test, and can Pass the VW-1 vertical burning test. In addition, by adding the two polymers of maleic anhydride grafted SEBS and polyacrylimide, the compatibility between the polymer and the intumescent flame retardant is greatly improved, and the intumescent flame retardant used is through the surface Modified flame retardant, which greatly improves the mechanical properties of the material, the tensile strength can reach 12-16MPa, the elongation at break can reach 400-500%, and the problem of material precipitation in water is also improved. No precipitation can be observed with the naked eye, and the solubility of the intumescent flame retardant in water at 90°C is only 1% of the original by quantitative precipitation method. Furthermore, since the melt viscosity of polypropylene is relatively low, the rheological property of the halogen-free flame-retardant cable material prepared by the invention is better, and the product has better appearance. The mechanical properties, flame retardant performance and heat resistance of the halogen-free flame-retardant cable material of the present invention are significantly higher than the index requirements of the industry standard for the halogen-free flame-retardant cable material, and the density is small, so it can be used as a flame-retardant cable and an optical cable sheath materials or insulating materials.

Detailed ways

The method of the present invention is described in further detail below with examples.

Example 1

20 parts by weight of SEBS, 20 parts of ethylene-vinyl acetate copolymer, 20 parts of ethylene-propylene-butylene terpolymer, 20 parts of polypropylene, 5 parts of high-density polyethylene, 5 parts of ethylene -octene copolymer, 5 parts of maleic anhydride grafted SEBS, 5 parts of polyacrylimide, 30 parts of ammonium polyphosphate, 15 parts of pentaerythritol, 15 parts of melamine, 0.75 parts of antioxidant 1010, 0.25 parts of antioxidant 168, 2 parts of lubricant stearic acid. The flame retardant is an intumescent flame retardant modified by the silane coupling agent KH570, the weight of the modifier is 1% of the weight of the intumescent flame retardant, and the modification is carried out by a dry treatment process. The specific process is as follows: firstly, the matrix resin and antioxidant are kneaded and melted on a double-roll mill at a mixing temperature of 190°C, and then the modified intumescent flame retardant is filled into the melted matrix resin. The mixing time is 30 minutes, and then the sheet is discharged from the double-roll mill, and pressed on a flat vulcanizer to obtain a white cable material. The mechanical properties of composite materials were tested according to the national standard GB/T 1040-92. The horizontal and vertical combustion test is tested according to the national standard GB/T 2408-1996, and the oxygen index is tested according to the national standard GB 2406-93.

According to the formula and process mentioned above, the halogen-free flame-retardant cable material obtained in our example: the hardness is Shore A90 degrees, the density is 1.18g/cm ³ , the tensile strength and elongation at break are 15.7MPa and 460% respectively , The horizontal and vertical combustion grades are respectively FH-1 and FV-0 grades, and the test result of the oxygen index is 32%. The 0.6mm single electronic wire can pass the VW-1 test, and the temperature resistance level of the product is 105°C. The product does not precipitate when it meets water.

Example 2

20 parts by weight of SEBS, 20 parts of ethylene-vinyl acetate copolymer, 20 parts of ethylene-propylene-butylene terpolymer, 20 parts of polypropylene, 5 parts of high-density polyethylene, 5 parts of ethylene -octene copolymer, 5 parts of maleic anhydride graft SEBS, 5 parts of polyacrylimide, 60 parts of ammonium polyphosphate, 10 parts of pentaerythritol, 10 parts of melamine, 0.75 parts of antioxidant 1010, 0.25 parts of antioxidant 168, 2 parts of lubricant zinc stearate. The flame retardant is an intumescent flame retardant modified by the silane coupling agent KH550, the weight of the modifier is 0.5% of the weight of the intumescent flame retardant, and the modification is carried out by a wet treatment process. The specific process is as follows: firstly, the matrix resin and antioxidant are kneaded and melted on a double-roll mill at a mixing temperature of 195°C, and then the modified intumescent flame retardant is filled into the melted matrix resin. The mixing time is 35 minutes, and then the sheet is discharged from the double-roll mill, and pressed on a flat vulcanizer to obtain a white cable material. The mechanical properties of composite materials were tested according to the national standard GB/T 1040-92. The horizontal and vertical combustion test is tested according to the national standard GB/T 2408-1996, and the oxygen index is tested according to the national standard GB 2406-93.

According to the formula and process mentioned above, the halogen-free flame-retardant cable material obtained in our example: the hardness is Shore A95 degrees, the density is 1.21g/cm ³ , the tensile strength and elongation at break are 13.2MPa and 510% respectively , The horizontal and vertical combustion grades are respectively FH-1 and FV-0 grades, and the test result of the oxygen index is 34%. The 0.6mm single electronic wire can pass the VW-1 test, and the temperature resistance level of the product is 105°C. The product does not precipitate when it meets water.

Example 3

SEBS of 50 parts by weight, 15 parts of ethylene-vinyl acetate copolymer, 15 parts of ethylene-propylene-butylene terpolymer, 15 parts of polypropylene, 2.5 parts of maleic anhydride grafted SEBS, 2.5 parts Polyacrylimide, 30 parts of ammonium polyphosphate, 15 parts of pentaerythritol, 15 parts of melamine, 0.75 parts of antioxidant 1010, 0.25 parts of antioxidant 168, 2 parts of lubricant oleic acid amide. The flame retardant is an intumescent flame retardant modified by the silane coupling agent KH560, and the weight of the modifier is 2.5% of the weight of the intumescent flame retardant, which is modified by a dry treatment process. The specific process is as follows: firstly, the matrix resin and antioxidant are mixed and melted on a double-roll mill at a mixing temperature of 185°C, and then the modified intumescent flame retardant is filled into the melted matrix resin. The mixing time is 25 minutes, and then the sheet is discharged from the double-roll mill, and pressed on a flat vulcanizer to obtain a white cable material. The mechanical properties of composite materials were tested according to the national standard GB/T 1040-92. The horizontal and vertical combustion test is tested according to the national standard GB/T 2408-1996, and the oxygen index is tested according to the national standard GB 2406-93.

According to the formula and process mentioned above, the halogen-free flame-retardant cable material obtained in our example: the hardness is Shore A80 degrees, the density is 1.18g/cm ³ , the tensile strength and elongation at break are 12.8MPa and 540% respectively , The horizontal and vertical combustion grades are FH-1 and FV-0 respectively, and the test result of the oxygen index is 31%. The 0.6mm single electronic wire can pass the VW-1 test, and the temperature resistance level of the product is 105°C. The product does not precipitate when it meets water.

Example 4

SEBS of 50 parts by weight, 15 parts of ethylene-vinyl acetate copolymer, 15 parts of ethylene-propylene-butylene terpolymer, 15 parts of polypropylene, 2.5 parts of maleic anhydride grafted SEBS, 2.5 parts Polyacrylimide, 60 parts of ammonium polyphosphate, 10 parts of pentaerythritol, 10 parts of melamine, 0.75 parts of antioxidant 1010, 0.25 parts of antioxidant 168, 2 parts of lubricant zinc stearate. The flame retardant is an intumescent flame retardant modified by the silane coupling agent KH560, the weight of the modifier is 3% of the weight of the intumescent flame retardant, and the modification is carried out by a dry treatment process. The specific process is as follows: firstly, the matrix resin and antioxidant are kneaded and melted on a double-roll mill at a mixing temperature of 190°C, and then the modified intumescent flame retardant is filled into the melted matrix resin. The mixing time is 35 minutes, and then the sheet is discharged from the double-roll mill, and pressed on a flat vulcanizer to obtain a white cable material. The mechanical properties of composite materials were tested according to the national standard GB/T 1040-92. The horizontal and vertical combustion test is tested according to the national standard GB/T 2408-1996, and the oxygen index is tested according to the national standard GB 2406-93.

According to the formula and process mentioned above, the halogen-free flame-retardant cable material obtained in our example: the hardness is 80 degrees Shore A, the density is 1.20g/cm ³ , the tensile strength and elongation at break are 12.3MPa and 512% respectively , The horizontal and vertical combustion grades are FH-1 and FV-0 respectively, and the test result of the oxygen index is 35%. The 0.6mm single electronic wire can pass the VW-1 test, and the temperature resistance level of the product is 105°C. The product does not precipitate when it meets water.

Example 5

36 parts by weight of SEBS, 18 parts of ethylene-vinyl acetate copolymer, 18 parts of ethylene-propylene-butylene terpolymer, 18 parts of polypropylene, 2 parts of high-density polyethylene, 2 parts of ethylene -octene copolymer, 3 parts of maleic anhydride grafted SEBS, 3 parts of polyacrylimide, 50 parts of ammonium polyphosphate, 12 parts of pentaerythritol, 12 parts of melamine, 0.75 parts of antioxidant 1010, 0.25 parts of antioxidant 168, 2 parts of lubricant stearic acid. The flame retardant is an intumescent flame retardant modified by the silane coupling agent KH550, the weight of the modifier is 2% of the weight of the intumescent flame retardant, and the modification is carried out by a wet treatment process. The specific process is as follows: firstly, the matrix resin and antioxidant are mixed and melted on a double-roll mill at a mixing temperature of 185°C, and then the modified intumescent flame retardant is filled into the melted matrix resin. The mixing time is 25 minutes, and then the sheet is discharged from the double-roll mill, and pressed on a flat vulcanizer to obtain a white cable material. The mechanical properties of composite materials were tested according to the national standard GB/T 1040-92. The horizontal and vertical combustion test is tested according to the national standard GB/T 2408-1996, and the oxygen index is tested according to the national standard GB 2406-93.

According to the formula and process mentioned above, the halogen-free flame-retardant cable material obtained in our example: the hardness is Shore A87 degrees, the density is 1.21g/cm ³ , the tensile strength and elongation at break are 14.3MPa and 505% respectively , The horizontal and vertical combustion grades are FH-1 and FV-0 respectively, and the test result of the oxygen index is 33%. The 0.6mm single electronic wire can pass the VW-1 test, and the temperature resistance level of the product is 105°C. The product does not precipitate when it meets water.

Claims (2)

1. A highly flame-retardant, high-heat-resistant, halogen-free intumescent flame-retardant cable material, characterized in that, The component parts by weight of the cable material are as follows: a)Matrix resin 100 Among them: SEBS 20～50 Ethylene-vinyl acetate copolymer 15～20 Ethylene-propylene-butene terpolymer 15～20 Polypropylene 15～20 High-density polyethylene 0～5 Ethylene-octene copolymer 0～5 Maleic anhydride grafted SEBS 2.5～5 Polyacrylimide 2.5～5 b) Flame retardant 60～80 Among them: ammonium polyphosphate type II 30～60 Pentaerythritol 10～15 Melamine 10～15 c) Lubricant 2 d) Antioxidant 1010 0.75 Antioxidant 168 0.25 The lubricant is one or a mixture of at least two of stearic acid, zinc stearate and oleic acid amide. 2. The preparation method of high flame-retardant, high-heat-resistant, halogen-free intumescent flame-retardant cable material according to claim 1, characterized in that: the above-mentioned components are mixed evenly on a double-roll mill, and the roll temperature is 190 +5°C, the mixing time is 30±5min, and then pressed on a flat vulcanizing machine at 190±5°C, cold pressed, and released from the mold.