Low-temperature-resistant cable sheath material and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant cable sheath material, which is prepared from the following raw materials in parts by weight: 40 to 60 parts of modified chlorinated polyethylene, 30 to 50 parts of silicon rubber, 5 to 6 parts of zinc oxide, 5 to 6 parts of magnesium oxide, 1.5 to 3 parts of calcium stearate, 1 to 3 parts of accelerant NA-2, 2 to 4 parts of gamma-aminopropyltriethoxysilane, 15 to 17 parts of liquid chlorinated paraffin with the chlorine content of 54 percent and 45 to 55 parts of calcined clay. The flame-retardant coating is prepared from the following components in parts by weight: 22 to 27 parts of high-wear-resistance carbon black, 11 to 13 parts of active kaolin, 3 to 6 parts of dicumyl peroxide, 0.5 to 2 parts of N, N-m-phenylene maleimide, 0.5 to 1.5 parts of trimethylolpropane trimethacrylate and 6 to 8 parts of organic phosphorus flame retardant. A fluorine-containing monomer and an acrylate copolymer are introduced into a modified chlorinated polyethylene structure, so that the low temperature resistance, toughness and waterproofness of the material are enhanced. And the used organophosphorus flame retardant is green and environment-friendly and has good compatibility with the resin, so that the heat resistance of the material is enhanced.

Description

Technical Field

[0001] The invention relates to a cable sheath material, in particular to a low-temperature resistant cable sheath material. Background Art

[0002] There is a big climate difference between the north and south of my country. The extremely cold northern regions have a large temperature difference between day and night, dry air, strong ultraviolet radiation and other harsh climates, which greatly restrict the use of cables. Therefore, it is urgent to develop cable sheath materials with excellent properties such as low temperature resistance and good flame retardant effect. However, as the harsh environment caused by global warming continues to intensify, although a large number of cable sheaths with low temperature resistance and good flame retardant effect have been prepared before, they have failed to meet the current use needs.

[0003] Patent No. 201410022483.5 discloses a cold-resistant cable sheath material, but still has the following shortcomings: (1) GNA-type chloroprene rubber and base material chlorinated polyethylene can both produce hydrogen chloride gas when burned, which increases the flame retardant pressure and pollutes the environment; (2) The use of magnesium hydroxide for flame retardancy has the problem of uneven dispersion due to excessive filling, which will reduce the strength of the plastic and affect other properties. Patent No. 201080015256.X discloses a method for synthesizing an organophosphorus flame retardant, which has excellent dispersibility and compatibility with a variety of synthetic resins and excellent heat resistance, but has the following shortcomings: (1) The synthetic raw material formaldehyde used is easy to explode after its vapor is mixed with air, which is very dangerous; (2) The structure of the organophosphorus flame retardant contains more oxygen atoms and has a higher polarity. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a low-temperature resistant cable sheath material and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] Step S1: mixing the modified chlorinated polyethylene and silicone rubber in an internal mixer at 70-80° C. for 3-4 minutes; then adding the calcium stearate, zinc oxide and surfactant γ-aminopropyltriethoxysilane and mixing for 2-3 minutes; finally adding the accelerator, organophosphorus flame retardant, magnesium oxide, calcined clay, high wear-resistant carbon black, activated kaolin and liquid chlorinated paraffin with a chlorine content of 54%, mixing for 1-2 minutes to form a mixed rubber material, which is discharged from the internal mixer when the temperature reaches 90-100° C.;

[0007] Step S2: thinly passing the mixed rubber material on an open mixer for 1-3 times, and swinging the rubber material for 2-4 times, and then calendering the mixed rubber material on a three-roll calender without slitting the mixed rubber material to obtain the calendered mixed rubber material;

[0008] Step S3: storing the calendered mixed rubber material at room temperature for 7-9 hours, and then mixing it in an internal mixer, adding the vulcanizing agent dicumyl peroxide, the co-vulcanizing agent N,N-phenylene maleimide and trimethylolpropane trimethacrylate when the mixing temperature reaches 90-120° C., and then mixing for 0.5-1.5 minutes, and then discharging the vulcanized mixed rubber material;

[0009] Step S4: the vulcanized mixed rubber material is thinned on an open mill for 1-3 times and swung for 2-4 times, and then cut into sheets on a three-roll calender, and the output rubber sheets are cooled by cooling rollers to obtain a low-temperature resistant cable sheath material.

[0010] Furthermore, the modified chlorinated polyethylene is prepared by the following method:

[0011] Step A1: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and acrylic acid are mixed in proportion, dibenzoyl peroxide is used as an initiator, xylene and butyl acetate are used as solvents, and the mixture is reacted at 100° C. for 6 hours to obtain an acrylic copolymer; the amount ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, acrylic acid, dibenzoyl peroxide, xylene and butyl acetate is: 45g:40g:10g:5g:1g:150mL:100mL, and the reaction process is as follows:

[0012]

[0013] During the reaction, methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and acrylic acid are connected by free radical polymerization under the action of dibenzoyl peroxide as an initiator to obtain an acrylic ester copolymer.

[0014] Step A2: After mixing perfluorooctylethanol and diphenylmethane 4,4′-diisocyanate, add 20% by mass dilute sulfuric acid solution and methanol, and react at 50° C. for 4 hours to obtain a fluorinated esterification product; the amount ratio of perfluorooctylethanol, diphenylmethane 4,4′-diisocyanate, 20% by mass dilute sulfuric acid solution and methanol is 1 mol: 1 mol: 100 mL: 200 mL, and the reaction process is as follows:

[0015]

[0016] During the reaction, the isocyanate group at one end of diphenylmethane 4,4'-diisocyanate acylates the alcoholic hydroxyl group of perfluorooctylethanol to obtain a fluorinated esterification product.

[0017] Step A3: After mixing the acrylic copolymer and the fluorinated ester product, add a 20% by mass solution of dilute sulfuric acid and methanol, and react at 70° C. for 4 hours to obtain a fluorinated acrylic copolymer; the amount ratio of the acrylic copolymer, the fluorinated ester product, the 20% by mass solution of dilute sulfuric acid and methanol is: 1 mol: 1 mol: 100 mL: 250 mL, and the reaction process is as follows:

[0018]

[0019] During the reaction, the hydroxyl group retained by hydroxyethyl methacrylate in the acrylic ester copolymer undergoes acylation reaction with the isocyanate group at the other end of diphenylmethane 4,4'-diisocyanate, and then a fluorine-containing monomer is introduced to obtain a fluorine-containing acrylic ester copolymer.

[0020] Step A4: After the fluorinated acrylate copolymer and chlorinated polyethylene are uniformly mixed, they are subjected to ultraviolet light treatment, and then melt blended in a twin-screw extruder to cause a grafting reaction between the fluorinated acrylate copolymer and the chlorinated polyethylene to obtain modified chlorinated polyethylene, the amount ratio of the fluorinated acrylate copolymer to the chlorinated polyethylene is 17-20%, the ultraviolet light wavelength of the ultraviolet light treatment is 200-400nm, the power is 2000-5000W, the treatment time is 5-8h, and the temperature of the melt blending is 90-110°C.

[0021] Furthermore, the organophosphorus flame retardant is prepared by the following method:

[0022] Step B1: sodium hydroxide, bisphenol A, acrolein and distilled water are added to a reactor, and reacted at 45° C. for 15-18 hours to obtain a mixture. The amount ratio of sodium hydroxide, bisphenol A, acrolein and distilled water is 105.1 g: 150 g: 149.3 g: 280 mL. The reaction process is as follows:

[0023]

[0024] During the reaction, acrolein with α-H and the four ortho positions of the two phenolic hydroxyl groups of bisphenol A react in a sodium hydroxide alkaline solution through a one-step phenol-formaldehyde condensation reaction to obtain a product in which the four ortho positions of the two phenolic hydroxyl groups in bisphenol A are replaced by acryl hydroxyl groups.

[0025] Step B2: The mixture is then cooled at room temperature for 1 hour, added to solvent a, and then dropped into a 36% by mass hydrochloric acid solution for acidification, the product is extracted and layered, and the upper organic layer is washed with distilled water to obtain a reaction product, the amount ratio of solvent a to 36% by mass hydrochloric acid solution is: 2000mL:400mL, and solvent a is one of 1-butanol, 2-butanol and 2-methoxyethanol.

[0026] Step B3: After the reaction product is evaporated and concentrated, DOPO and 1-methoxy-2-propanol are added, and the reaction is carried out at 200°C, and the solvent and the generated water are removed by a distillation device, and stirred for 4 hours to obtain a viscous organic phosphorus flame retardant. The amount ratio of the reaction product, DOPO and 1-methoxy-2-propanol is 2000g:885g:980mL. The reaction process is as follows:

[0027]

[0028] During the reaction, the four propenyl hydroxyl groups of the product in which the four ortho positions of the two phenolic hydroxyl groups in the bisphenol A are replaced by propenyl hydroxyl groups undergo a dehydration condensation reaction with DOPO to obtain an organic phosphorus flame retardant with a phosphate ester structure.

[0029] Beneficial effects of the present invention:

[0030] In the present invention, chlorinated polyethylene is a rubber with excellent low temperature resistance, corrosion resistance and UV resistance. Acrylic ester copolymer itself is a toughening agent and low temperature impact modifier. Fluorine-containing monomers are introduced into it to enhance hydrophobicity and thus enhance the waterproofness of the material. Chlorinated polyethylene is modified with fluorine-containing acrylic ester copolymer to enhance the low temperature resistance and toughness of the plastic. Silicone rubber has excellent low temperature resistance and its use does not increase the content of hydrogen chloride gas, thus reducing the flame retardant pressure. The synthetic organophosphorus flame retardant not only has excellent flame retardant properties, but also has good dispersibility and compatibility with resins, is easy to mix with rubber, and can improve the properties of rubber well. Acrolein used in the preparation process of the organophosphorus flame retardant is liquid, not easy to volatilize and has low toxicity. The organophosphorus flame retardant introduces a low polarity olefin group, which can be better compatible with the base material modified chlorinated polyethylene and will not affect other properties of the plastic due to excessive filling. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] A modified chlorinated polyethylene is prepared by the following steps:

[0034] Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and acrylic acid are mixed in proportion, dibenzoyl peroxide is used as an initiator, xylene and butyl acetate are used as solvents, and the mixture is reacted at 100°C for 6 hours to obtain an acrylic copolymer; the amount ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, acrylic acid, dibenzoyl peroxide, xylene and butyl acetate is: 45g:40g:10g:5g:1g:150mL:100mL;

[0035] After mixing perfluorooctylethanol and diphenylmethane 4,4′-diisocyanate, add 20% by mass dilute sulfuric acid solution and methanol, and react at 50°C for 4 hours to obtain a fluorinated ester product; the amount ratio of perfluorooctylethanol, diphenylmethane 4,4′-diisocyanate, 20% by mass dilute sulfuric acid solution and methanol is 1 mol: 1 mol: 100 mL: 200 mL;

[0036] After mixing the acrylic copolymer and the fluorine-containing esterification product, adding a 20% by mass dilute sulfuric acid solution and methanol, and reacting at 70° C. for 4 hours to obtain a fluorine-containing acrylic copolymer; the amount ratio of the acrylic copolymer, the fluorine-containing esterification product, the 20% by mass dilute sulfuric acid solution and methanol is: 1 mol: 1 mol: 100 mL: 250 mL;

[0037] The fluorinated acrylate copolymer and chlorinated polyethylene are uniformly mixed and then subjected to ultraviolet light treatment, and then melt blended in a twin-screw extruder to cause a grafting reaction between the fluorinated acrylate copolymer and the chlorinated polyethylene to obtain modified chlorinated polyethylene; the dosage ratio of the fluorinated acrylate copolymer to the chlorinated polyethylene is 17%, the ultraviolet light wavelength of the ultraviolet light treatment is 200nm, the power is 2000W, the treatment time is 5h, and the temperature of the melt blending is 90°C.

[0038] Example 2

[0039] A modified chlorinated polyethylene is prepared by the following steps:

[0040] Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and acrylic acid are mixed in proportion, dibenzoyl peroxide is used as an initiator, xylene and butyl acetate are used as solvents, and the mixture is reacted at 100°C for 6 hours to obtain an acrylic copolymer; the amount ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, acrylic acid, dibenzoyl peroxide, xylene and butyl acetate is: 45g:40g:10g:5g:1g:150mL:100mL;

[0041] After mixing perfluorooctylethanol and diphenylmethane 4,4′-diisocyanate, add 20% by mass dilute sulfuric acid solution and methanol, and react at 50°C for 4 hours to obtain a fluorinated ester product; the amount ratio of perfluorooctylethanol, diphenylmethane 4,4′-diisocyanate, 20% by mass dilute sulfuric acid solution and methanol is 1 mol: 1 mol: 100 mL: 200 mL;

[0042] After mixing the acrylic copolymer and the fluorine-containing esterification product, adding a 20% by mass dilute sulfuric acid solution and methanol, and reacting at 70° C. for 4 hours to obtain a fluorine-containing acrylic copolymer; the amount ratio of the acrylic copolymer, the fluorine-containing esterification product, the 20% by mass dilute sulfuric acid solution and methanol is: 1 mol: 1 mol: 100 mL: 250 mL;

[0043] The fluorinated acrylate copolymer and chlorinated polyethylene are uniformly mixed and then subjected to ultraviolet light treatment, and then melt blended in a twin-screw extruder to cause a grafting reaction between the fluorinated acrylate copolymer and the chlorinated polyethylene to obtain modified chlorinated polyethylene; the dosage ratio of the fluorinated acrylate copolymer to the chlorinated polyethylene is 18.5%, the ultraviolet light wavelength of the ultraviolet light treatment is 300nm, the power is 3500W, the treatment time is 6.5h, and the temperature of the melt blending is 100°C.

[0044] Example 3

[0045] A modified chlorinated polyethylene is prepared by the following steps:

[0046] Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and acrylic acid are mixed in proportion, dibenzoyl peroxide is used as an initiator, xylene and butyl acetate are used as solvents, and the mixture is reacted at 100°C for 6 hours to obtain an acrylic copolymer; the amount ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, acrylic acid, dibenzoyl peroxide, xylene and butyl acetate is: 45g:40g:10g:5g:1g:150mL:100mL;

[0047] After mixing perfluorooctylethanol and diphenylmethane 4,4′-diisocyanate, add 20% by mass dilute sulfuric acid solution and methanol, and react at 50°C for 4 hours to obtain a fluorinated ester product; the amount ratio of perfluorooctylethanol, diphenylmethane 4,4′-diisocyanate, 20% by mass dilute sulfuric acid solution and methanol is 1 mol: 1 mol: 100 mL: 200 mL;

[0048] After mixing the acrylic copolymer and the fluorine-containing esterification product, adding a 20% by mass dilute sulfuric acid solution and methanol, and reacting at 70° C. for 4 hours to obtain a fluorine-containing acrylic copolymer; the amount ratio of the acrylic copolymer, the fluorine-containing esterification product, the 20% by mass dilute sulfuric acid solution and methanol is: 1 mol: 1 mol: 100 mL: 250 mL;

[0049] The fluorinated acrylate copolymer and chlorinated polyethylene are uniformly mixed and then subjected to ultraviolet light treatment, and then melt blended in a twin-screw extruder to cause a grafting reaction between the fluorinated acrylate copolymer and the chlorinated polyethylene to obtain modified chlorinated polyethylene; the amount ratio of the fluorinated acrylate copolymer to the chlorinated polyethylene is 20%, the ultraviolet light wavelength of the ultraviolet light treatment is 400nm, the power is 5000W, the treatment time is 8h, and the temperature of the melt blending is 110°C.

[0050] Example 4

[0051] An organophosphorus flame retardant is prepared by the following steps:

[0052] Sodium hydroxide, bisphenol A, acrolein and distilled water were added into the reactor, and the mixture was reacted at 45° C. for 15 h to obtain a mixture, wherein the amount ratio of sodium hydroxide, bisphenol A, acrolein and distilled water was 105.1 g: 150 g: 149.3 g: 280 mL;

[0053] Then, the mixture was cooled at room temperature for 1 hour, added to 1-butanol, and then a hydrochloric acid solution with a mass fraction of 36% was dropped into it for acidification, the product was extracted and layered, and the upper organic layer was washed with distilled water to obtain a reaction product, and the amount ratio of 1-butanol to the hydrochloric acid solution with a mass fraction of 36% was: 2000mL:400mL;

[0054] After the reaction product is evaporated and concentrated, DOPO and 1-methoxy-2-propanol are added, and the reaction is carried out at 200° C., and the solvent and the generated water are removed by a distillation device. The mixture is stirred for 4 hours to obtain a viscous organophosphorus flame retardant. The amount ratio of the reaction product, DOPO and 1-methoxy-2-propanol is 2000 g:885 g:980 mL.

[0055] Example 5

[0056] An organophosphorus flame retardant is prepared by the following steps:

[0057] Sodium hydroxide, bisphenol A, acrolein and distilled water were added into the reactor, and the mixture was reacted at 45° C. for 16 hours to obtain a mixture, wherein the amount ratio of sodium hydroxide, bisphenol A, acrolein and distilled water was 105.1 g: 150 g: 149.3 g: 280 mL;

[0058] Then, the mixture was cooled at room temperature for 1 hour, added to 2-butanol, and then a hydrochloric acid solution with a mass fraction of 36% was dropped into it for acidification, the product was extracted and layered, and the upper organic layer was washed with distilled water to obtain a reaction product, and the amount ratio of 2-butanol to the hydrochloric acid solution with a mass fraction of 36% was: 2000mL:400mL;

[0059] After the reaction product is evaporated and concentrated, DOPO and 1-methoxy-2-propanol are added, and the reaction is carried out at 200° C., and the solvent and the generated water are removed by a distillation device. The mixture is stirred for 4 hours to obtain a viscous organophosphorus flame retardant. The amount ratio of the reaction product, DOPO and 1-methoxy-2-propanol is 2000 g:885 g:980 mL.

[0060] Example 6

[0061] An organophosphorus flame retardant is prepared by the following steps:

[0062] Sodium hydroxide, bisphenol A, acrolein and distilled water were added into the reactor, and the mixture was reacted at 45° C. for 18 hours to obtain a mixture, wherein the amount ratio of sodium hydroxide, bisphenol A, acrolein and distilled water was 105.1 g: 150 g: 149.3 g: 280 mL;

[0063] Then, the mixture was cooled at room temperature for 1 hour, added to 2-methoxyethanol, and then a 36% hydrochloric acid solution was added dropwise to acidify, the product was extracted and layered, and the upper organic layer was washed with distilled water to obtain a reaction product, and the amount ratio of 2-methoxyethanol to the 36% hydrochloric acid solution was: 2000mL:400mL;

[0064] After the reaction product is evaporated and concentrated, DOPO and 1-methoxy-2-propanol are added, and the reaction is carried out at 200° C., and the solvent and the generated water are removed by a distillation device. The mixture is stirred for 4 hours to obtain a viscous organophosphorus flame retardant. The amount ratio of the reaction product, DOPO and 1-methoxy-2-propanol is 2000 g:885 g:980 mL.

[0065] Example 7

[0066] A low temperature resistant cable sheath material, characterized by comprising the following raw materials in parts by weight:

[0067] 40 parts of modified chlorinated polyethylene, 30 parts of silicone rubber, 5 parts of zinc oxide, 5 parts of magnesium oxide, 1.5 parts of calcium stearate, 1 part of accelerator NA-22, 2 parts of γ-aminopropyl triethoxysilane, 15 parts of liquid chlorinated paraffin with a chlorine content of 54%, 45 parts of calcined clay, 22 parts of high wear-resistant carbon black, 11 parts of activated kaolin, 3 parts of diisopropyl peroxide, 0.5 parts of N, N-phenylene maleimide, 0.5 parts of trimethylolpropane trimethacrylate, and 6 parts of organic phosphorus flame retardant;

[0068] The low temperature resistant cable sheath material is made by the following steps:

[0069] The modified chlorinated polyethylene and silicone rubber obtained in Example 1 were mixed in an internal mixer at 70° C. for 3 minutes; the calcium stearate, zinc oxide and surfactant γ-aminopropyltriethoxysilane were then added and mixed for 2 minutes; finally, the accelerator, the organic phosphorus flame retardant obtained in Example 4, magnesium oxide, calcined clay, high wear-resistant carbon black, activated kaolin and liquid chlorinated paraffin with a chlorine content of 54% were added and mixed for 1 minute to form a mixed rubber material, which was discharged from the internal mixer when the temperature reached 90° C.;

[0070] The mixed rubber material is thinned once on an open mill, and the rubber is swung twice, and then calendered on a three-roll calender without slitting to obtain a calendered mixed rubber material;

[0071] The calendered mixed rubber material is stored at room temperature for 7 hours, and then put into an internal mixer for mixing, and when the mixing temperature reaches 90° C., the vulcanizing agent dicumyl peroxide, the co-vulcanizing agent N,N-phenylene maleimide and trimethylolpropane trimethacrylate are added, followed by mixing for 0.5 minutes, and then the vulcanized mixed rubber material is discharged;

[0072] The vulcanized mixed rubber material is thinned once on an open mill and swung twice, then cut into sheets on a three-roll calender, and the output rubber sheets are cooled by cooling rollers to obtain a low-temperature resistant cable sheath material.

[0073] Example 8

[0074] A low temperature resistant cable sheath material, characterized by comprising the following raw materials in parts by weight:

[0075] 50 parts of modified chlorinated polyethylene, 40 parts of silicone rubber, 5.5 parts of zinc oxide, 5.5 parts of magnesium oxide, 2.25 parts of calcium stearate, 22 parts of accelerator NA-2, 3 parts of γ-aminopropyl triethoxysilane, 16 parts of liquid chlorinated paraffin with a chlorine content of 54%, 50 parts of calcined clay, 24.5 parts of high wear-resistant carbon black, 12 parts of activated kaolin, 4.5 parts of diisopropyl peroxide, 1.25 parts of N, N-phenylene maleimide, 1 part of trimethylolpropane trimethacrylate, and 7 parts of organic phosphorus flame retardant;

[0076] The low temperature resistant cable sheath material is made by the following steps:

[0077] The modified chlorinated polyethylene and silicone rubber obtained in Example 2 were mixed in an internal mixer at 75°C for 3.5 minutes; the calcium stearate, zinc oxide and surfactant γ-aminopropyltriethoxysilane were then added and mixed for 2.5 minutes; finally, the accelerator, the organic phosphorus flame retardant obtained in Example 5, magnesium oxide, calcined clay, high wear-resistant carbon black, activated kaolin and liquid chlorinated paraffin with a chlorine content of 54% were added and mixed for 1.5 minutes to form a mixed rubber material, which was discharged from the internal mixer when the temperature reached 95°C;

[0078] The mixed rubber material is thinly passed through an open mill twice, and the rubber is swung three times, and then calendered on a three-roll calender without slitting to obtain a calendered mixed rubber material;

[0079] The calendered mixed rubber material is stored at room temperature for 8 hours, and then put into an internal mixer for mixing, and when the mixing temperature reaches 105° C., the vulcanizing agent dicumyl peroxide, the co-vulcanizing agent N,N-phenylene maleimide and trimethylolpropane trimethacrylate are added, followed by mixing for 1 minute, and then the vulcanized mixed rubber material is discharged;

[0080] The vulcanized mixed rubber material is thinned twice on an open mill and swung three times, then cut into sheets on a three-roll calender, and the output rubber sheets are cooled by cooling rollers to obtain a low-temperature resistant cable sheath material.

[0081] Example 9

[0082] A low temperature resistant cable sheath material, characterized by comprising the following raw materials in parts by weight:

[0083] 60 parts of modified chlorinated polyethylene, 50 parts of silicone rubber, 6 parts of zinc oxide, 6 parts of magnesium oxide, 3 parts of calcium stearate, 3 parts of accelerator NA-22, 4 parts of γ-aminopropyl triethoxysilane, 17 parts of liquid chlorinated paraffin with a chlorine content of 54%, 55 parts of calcined clay, 27 parts of high wear-resistant carbon black, 13 parts of activated kaolin, 6 parts of diisopropyl peroxide, 2 parts of N, N-phenylene maleimide, 1.5 parts of trimethylolpropane trimethacrylate, and 8 parts of organic phosphorus flame retardant;

[0084] The low temperature resistant cable sheath material is made by the following steps:

[0085] The modified chlorinated polyethylene and silicone rubber obtained in Example 3 were mixed in an internal mixer at 80° C. for 4 minutes; the calcium stearate, zinc oxide and surfactant γ-aminopropyltriethoxysilane were then added and mixed for 3 minutes; finally, the accelerator, the organic phosphorus flame retardant obtained in Example 6, magnesium oxide, calcined clay, high wear-resistant carbon black, activated kaolin and liquid chlorinated paraffin with a chlorine content of 54% were added and mixed for 2 minutes to form a mixed rubber material, which was discharged from the internal mixer when the temperature reached 100° C.;

[0086] The mixed rubber material is thinned on an open mill for 3 times and swung for 4 times, and then calendered on a three-roll calender without slitting to obtain a calendered mixed rubber material;

[0087] The calendered mixed rubber material is stored at room temperature for 9 hours, and then put into an internal mixer for mixing, and when the mixing temperature reaches 120° C., the vulcanizing agent dicumyl peroxide, the co-vulcanizing agent N,N-phenylene maleimide and trimethylolpropane trimethacrylate are added, followed by mixing for 1.5 minutes, and then the vulcanized mixed rubber material is discharged;

[0088] The vulcanized mixed rubber material is thinned on an open mill for 3 times and swung for 4 times, and then cut into sheets on a three-roll calender. The output rubber sheets are cooled by cooling rollers to obtain a low-temperature resistant cable sheath material.

[0089] Comparative Example 1

[0090] This comparative example is a commercially available low-temperature resistant cable sheath material.

[0091] Comparative Example 2

[0092] Compared with Example 9, the organic phosphorus flame retardant is replaced with magnesium hydroxide, and the other steps are exactly the same as Example 9 to obtain a low-temperature resistant cable sheath material.

[0093] Comparative Example 3

[0094] Compared with Example 9, the modified chlorinated polyethylene is replaced with chlorinated polyethylene, and the other steps are exactly the same as Example 9 to obtain a low-temperature resistant cable sheath material.

[0095] The low temperature resistant cable sheath material prepared by the present invention is further tested for its effect, and the test results are as follows.

[0096] In order to test the low-temperature resistant cable sheath material prepared by the present invention, a mechanical property test was performed according to the GB / T 2951.11-2008 standard method, a -40°C low-temperature tensile property test was performed according to the GB / T 2951.14-2008 standard method, a thermal stability experiment was performed according to the GB / T 2951.32-2008 standard method, and an oxygen index test was performed according to the GB / T 2406-93 standard method. The results are shown in Table 1.

[0097] Table 1:

[0098]

[0099] In order to test the waterproof performance of the low-temperature resistant cable sheath material prepared by the present invention, a cable sample weighing 150.0 g was immersed in water (water temperature 15°C), and both ends of the sample were sealed and extended 300 mm above the water surface. After soaking for one week, the weight after soaking was measured and the shielding layer was removed after soaking to observe whether there was moisture on the outer surface of the cable conductor, and the results were recorded in Table 2.

[0100] Table 2:

[0101] Group Weight after immersion / g Increase / % Is there moisture on the surface? Example 7 150.7 0.47 no Example 8 150.6 0.40 no Example 9 150.4 0.27 no Comparative Example 1 152.0 1.33 no Comparative Example 3 151.6 1.07 no

[0102] According to the data in Table 1, compared with Example 1, it can be seen that the low-temperature resistant cable sheath material prepared by the present invention has better low-temperature resistance, heat resistance, toughness and flame retardancy than the commercially available low-temperature resistant cable sheath material; compared with Example 2, it can be seen that the use of synthetic organic phosphorus flame retardant enhances the heat resistance of the material compared with magnesium hydroxide flame retardancy; compared with Example 3, it can be seen that the use of modified chlorinated polyethylene improves the low-temperature resistance of the cable sheath material compared with chlorinated polyethylene. According to the data in Table 2, compared with Example 1 and Comparative Example 3, it can be seen that the weight change of the cable in the embodiment is very small, less than 0.5%, while the weight change of the cable in Comparative Example 1 and Comparative Example 3 reaches more than 1.0%, which shows that the modified chlorinated polyethylene in the present invention improves the waterproofness of the cable sheath material.

[0103] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A low temperature resistant cable sheath material and a preparation method thereof, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of modified chlorinated polyethylene, 30-50 parts of silicone rubber, 5-6 parts of zinc oxide, 5-6 parts of magnesium oxide, 1.5-3 parts of calcium stearate, 1-3 parts of accelerator NA-221, 2-4 parts of gamma-aminopropyltriethoxysilane, 15-17 parts of liquid chlorinated paraffin with a chlorine content of 54%, 45-55 parts of calcined clay, 22-27 parts of high wear-resistant carbon black, 11-13 parts of activated kaolin, 3-6 parts of diisopropyl peroxide, 0.5-2 parts of N,N-phenylene maleimide, 0.5-1.5 parts of trimethylolpropane trimethacrylate and 6-8 parts of organic phosphorus flame retardant.

2. The low temperature resistant cable sheath material according to claim 1, characterized in that: The modified chlorinated polyethylene is prepared by the following steps: Step A1: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and acrylic acid are mixed in proportion, dibenzoyl peroxide is used as an initiator, xylene and butyl acetate are used as solvents, and the mixture is reacted at 100° C. for 6 hours to obtain an acrylic ester copolymer; Step A2: After mixing perfluorooctylethanol and diphenylmethane 4,4′-diisocyanate, add 20% by mass of dilute sulfuric acid solution and methanol, and react at 50° C. for 4 hours to obtain a fluorinated esterification product; Step A3: after mixing the acrylic ester copolymer and the fluorine-containing esterification product, adding 20% ​​by mass of dilute sulfuric acid solution and methanol, reacting at 70° C. for 4 hours to obtain a fluorine-containing acrylic ester copolymer; Step A4: The fluorinated acrylic copolymer and chlorinated polyethylene are uniformly mixed and then subjected to ultraviolet light treatment, and then melt-blended in a twin-screw extruder to obtain modified chlorinated polyethylene.

3. According to the low-temperature resistant cable sheath material described in claim 2, the amount ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, acrylic acid, dibenzoyl peroxide, xylene and butyl acetate in step A1 is: 45g:40g:10g:5g:1g:150mL:100mL; the amount ratio of perfluorooctylethanol, diphenylmethane 4,4′-diisocyanate, 20% dilute sulfuric acid solution and methanol in step A2 is 1mol:1mol:100mL:200mL; the amount ratio of acrylic ester copolymer, fluorine-containing esterification product, 20% dilute sulfuric acid solution and methanol in step A3 is: 1mol:1mol:100mL:250mL.

4. According to the low-temperature resistant cable sheath material of claim 2, the ratio of the fluorinated acrylic copolymer to the chlorinated polyethylene in step A4 is 17-20%, the ultraviolet light wavelength of the ultraviolet light treatment is 200-400nm, the power is 2000-5000W, the treatment time is 5-8h, and the temperature of the melt blending is 90-110°C.

5. The low temperature resistant cable sheath material according to claim 1, characterized in that: The organophosphorus flame retardant is prepared by the following method: Step B1: adding sodium hydroxide, bisphenol A, acrolein and distilled water into a reactor, reacting at 45° C. for 15-18 hours to obtain a mixture; Step B2: The mixture is then cooled at room temperature for 1 hour, added to solvent a, and then dropped into a 36% by mass hydrochloric acid solution for acidification, the product is extracted and separated into layers, and the upper organic layer is washed with distilled water to obtain a reaction product. Step B3: After the reaction product is evaporated and concentrated, DOPO and 1-methoxy-2-propanol are added, and the reaction is carried out at 200° C., and the solvent and generated water are removed by a distillation device. The mixture is stirred for 4 hours to obtain a viscous organic phosphorus flame retardant.

6. According to the low-temperature resistant cable sheath material of claim 5, the amount ratio of sodium hydroxide, bisphenol A, acrolein and distilled water in step B1 is 105.1g:150g:149.3g:280mL; the amount ratio of the reaction product, DOPO and 1-methoxy-2-propanol in step B3 is 2000g:885g:980mL.

7. A low-temperature resistant cable sheath material according to claim 5, wherein the amount ratio of the solvent a and the 36% hydrochloric acid solution in step B2 is: 2000mL:400mL, and the solvent a is one of 1-butanol, 2-butanol and 2-methoxyethanol.

8. The low temperature resistant cable sheath material and preparation method thereof according to claim 1, characterized in that: The steps include: Step S1: mixing the modified chlorinated polyethylene and silicone rubber in an internal mixer at 70-80° C. for 3-4 minutes; then adding the calcium stearate, zinc oxide and surfactant γ-aminopropyltriethoxysilane and mixing for 2-3 minutes; finally adding the accelerator, organophosphorus flame retardant, magnesium oxide, calcined clay, high wear-resistant carbon black, activated kaolin and liquid chlorinated paraffin with a chlorine content of 54%, mixing for 1-2 minutes to form a mixed rubber material, which is discharged from the internal mixer when the temperature reaches 90-100° C.; Step S2: thinly passing the mixed rubber material on an open mixer for 1-3 times, and swinging the rubber material for 2-4 times, and then calendering the mixed rubber material on a three-roll calender without slitting the mixed rubber material to obtain the calendered mixed rubber material; Step S3: storing the calendered mixed rubber material at room temperature for 7-9 hours, and then mixing it in an internal mixer, adding the vulcanizing agent dicumyl peroxide, the co-vulcanizing agent N,N-phenylene maleimide and trimethylolpropane trimethacrylate when the mixing temperature reaches 90-120° C., and then mixing for 0.5-1.5 minutes, and then discharging the vulcanized mixed rubber material; Step S4: the vulcanized mixed rubber material is thinned on an open mill for 1-3 times and swung for 2-4 times, and then cut into sheets on a three-roll calender, and the output rubber sheets are cooled by cooling rollers to obtain a low-temperature resistant cable sheath material.

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