High-temperature-resistant PVC composite cable material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant PVC composite cable material and a preparation method thereof. The high-temperature-resistant PVC composite cable material comprises the following raw materials in parts by weight: 60-100 parts of PVC resin, 10-15 parts of mica powder, 3-5 parts of epoxidized soybean oil, 8-10 parts of a calcium-zinc stabilizer, 2-5 parts of a plasticizer and 5-10 parts of a synergistic flame retardant. The mica powder and the synergistic flame retardant are added, the cable material can be endowed with excellent flame retardance through an inorganic-organic synergistic effect, and the prepared synergistic flame retardant is of a hyperbranched structure, so that the compatibility of the flame retardant and a matrix can be improved, a micromolecular flame retardant is prevented from being easily migrated, and the flame retardant effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cable materials, and in particular to a high-temperature resistant PVC composite cable material and a preparation method thereof. Background Art

[0002] With the rapid development of the wire and cable industry, the demand for wires and cables has gradually increased, and their applications have become more and more extensive. The base material of wires and cables is mainly PVC plastic, which is one of the five general synthetic plastics and the second largest plastic variety in the world after polyethylene. PVC cable material is based on polyvinyl chloride as the base resin, with stabilizers, plasticizers, inorganic fillers, additives, lubricants and other additives added, and the particles are prepared by mixing, kneading and extruding. This PVC cable material has poor high temperature resistance and low toughness, which affects the service life of the cable and greatly limits the use of polyvinyl chloride cables. In addition, PVC wires and cables have the potential safety hazard of being flammable at high temperatures. The existing PVC cable materials still have defects such as not being resistant to high temperature aging and low tensile strength after aging, which affects the service life of the cable. Therefore, we propose a high temperature resistant PVC cable material and a preparation method thereof. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a high temperature resistant PVC composite cable material and a preparation method thereof.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A high temperature resistant PVC composite cable material, comprising the following raw materials in parts by weight: 60-100 parts of PVC resin, 10-15 parts of mica powder, 3-5 parts of epoxy soybean oil, 8-10 parts of calcium zinc stabilizer, 2-5 parts of plasticizer, and 5-10 parts of synergistic flame retardant;

[0006] The synergistic flame retardant is prepared by the following steps:

[0007] Step S1, adding a 15% by mass aqueous solution of tetrakis(hydroxymethyl)phosphonium sulfate to a reaction kettle, stirring at a uniform speed and adding barium hydroxide, continuing stirring for 2 hours, and then dripping a 20% by mass aqueous solution of hydrogen peroxide until the starch potassium iodide reagent turns blue, then removing the solvent by rotary evaporation, and drying at 80-85° C. to obtain an intermediate 1, wherein the weight ratio of the tetrakis(hydroxymethyl)phosphonium sulfate aqueous solution to the barium hydroxide is controlled to be 5.40-5.45 g:30-32 g;

[0008] In step S1, intermediate 1 is prepared by tetrakis(hydroxymethyl)phosphonium sulfate and barium hydroxide, and the reaction process is as follows:

[0009]

[0010] Step S2, adding itaconic anhydride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide into a three-necked flask, adding tetrahydrofuran, stirring magnetically and heating to 50°C, reflux reaction for 6 hours, and after the reaction, removing the solvent by rotary evaporation, washing the filter cake with ethanol and vacuum drying at 50-55°C to obtain intermediate 2, wherein the amount ratio of itaconic anhydride, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and tetrahydrofuran is controlled to be 5.5-6g:10-12g:100mL;

[0011] In step S2, the carbon-carbon double bond on itaconic anhydride reacts with the phosphorus-hydrogen bond on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide to prepare intermediate 2. From the structural point of view, intermediate 2 has both a biphenyl structure and a phosphorus element, has good thermal stability and flame retardant properties, and introduces sulfur element, which can improve the flame retardant effect of phosphorus. The prepared sulfur-containing compound will decompose at high temperature, release strong acids such as sulfuric acid, and promote dehydration and carbonization, so it can also have a good flame retardant effect in the condensed phase. In addition, the introduction of sulfur element can increase the phosphorus-hydrogen bond reaction activity and improve the reaction efficiency.

[0012] Step S3, adding intermediate 1 and intermediate 2 to N, N-dimethylformamide, adding p-toluenesulfonic acid, heating to 110-120°C, magnetically stirring and reacting for 6 hours, after the reaction is completed, removing the solvent by rotary evaporation, and then placing it under vacuum and drying at 70-85°C to obtain a synergistic flame retardant, and controlling the usage ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid and N, N-dimethylformamide to be 1-1.2g:6-6.5g:30-50mg:100mL.

[0013] In step S3, the hydroxyl group on the intermediate 1 can react with the anhydride group on the intermediate 2 to prepare a synergistic flame retardant. The flame retardant is a hyperbranched structure that can improve the compatibility of the flame retardant with the matrix and improve the flame retardant effect.

[0014] Furthermore, the weight ratio of calcium to zinc in the calcium zinc stabilizer is 2:1.

[0015] Furthermore, the plasticizer is trioctyl trimellitate or dioctyl terephthalate.

[0016] A method for preparing a high temperature resistant PVC composite cable material comprises the following steps:

[0017] After uniformly mixing PVC resin, mica powder, epoxy soybean oil, calcium zinc stabilizer, plasticizer and synergistic flame retardant, use a mixer to mix at 170℃-175℃ for 5-8min, then transfer to a flat vulcanizer and hot press at a temperature between 170℃-175℃ and a pressure of 100MPa-120MPa, take out and cold press to obtain a high temperature resistant PVC composite cable material.

[0018] Beneficial effects of the present invention:

[0019] The present invention prepares a high-temperature resistant PVC composite cable material. The PVC resin is used as a matrix, and mica powder and a synergistic flame retardant are added to give the cable material excellent flame retardant properties through inorganic-organic synergistic action. The synergistic flame retardant is used to prepare an intermediate 1 through tetrakis(hydroxymethyl)phosphonium sulfate and barium hydroxide during the preparation process. Then, the carbon-carbon double bond on itaconic anhydride reacts with the phosphorus-hydrogen bond on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide to prepare an intermediate 2. The intermediate 2 has both a biphenyl structure and a phosphorus element in terms of structure, and has good thermal stability and Flame retardant properties, and the introduction of sulfur element, sulfur element can improve the flame retardant effect of phosphorus, the obtained sulfur-containing compound will decompose at high temperature, release strong acids such as sulfuric acid, and promote dehydration and carbonization, so it can also have a good flame retardant effect in the condensed phase. In addition, the introduction of sulfur element can increase the reactivity of phosphorus-hydrogen bond and improve the reaction efficiency. Finally, the hydroxyl group on intermediate 1 reacts with the anhydride group on intermediate 2 to prepare a synergistic flame retardant. The flame retardant is a hyperbranched structure, which can improve the compatibility of the flame retardant and the matrix, prevent the small molecule flame retardant from easily migrating, and improve the flame retardant effect. DETAILED DESCRIPTION

[0020] 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.

[0021] Example 1

[0022] A high temperature resistant PVC composite cable material, comprising the following raw materials in parts by weight: 60 parts of PVC resin, 10 parts of mica powder, 3 parts of epoxy soybean oil, 8 parts of calcium zinc stabilizer, 2 parts of plasticizer, and 5 parts of synergistic flame retardant;

[0023] The high temperature resistant PVC composite cable material is made by the following steps:

[0024] After PVC resin, mica powder, epoxy soybean oil, calcium zinc stabilizer, plasticizer and synergistic flame retardant are mixed evenly, they are mixed in a mixer at 170°C for 5 minutes, then transferred to a flat vulcanizer and hot-pressed at a temperature of 170°C and a pressure of 100MPa, taken out and cold-pressed to obtain a high-temperature resistant PVC composite cable material.

[0025] The synergistic flame retardant is prepared by the following steps:

[0026] Step S1, adding a 15% by mass aqueous solution of tetrakis(hydroxymethyl)phosphonium sulfate to a reaction kettle, stirring at a uniform speed and adding barium hydroxide, continuing stirring for 2 hours, and then dripping a 20% by mass aqueous solution of hydrogen peroxide until the starch potassium iodide reagent turns blue, then rotary evaporating to remove the solvent, drying at 80° C. to obtain an intermediate 1, wherein the weight ratio of the tetrakis(hydroxymethyl)phosphonium sulfate to the barium hydroxide is controlled to be 5.40 g:30 g;

[0027] Step S2, adding itaconic anhydride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide into a three-necked flask, adding tetrahydrofuran, stirring magnetically and heating to 50°C, reflux reaction for 6 hours, and after the reaction, removing the solvent by rotary evaporation, washing the filter cake with ethanol and vacuum drying at 50°C to obtain intermediate 2, wherein the amount ratio of itaconic anhydride, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and tetrahydrofuran is controlled to be 5.5g:10g:100mL;

[0028] Step S3, adding intermediate 1 and intermediate 2 to N, N-dimethylformamide, adding p-toluenesulfonic acid, heating to 110°C, magnetically stirring and reacting for 6 hours, after the reaction is completed, removing the solvent by rotary evaporation, and then vacuum drying at 70°C to obtain a synergistic flame retardant, and controlling the usage ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid and N, N-dimethylformamide to be 1g:6g:30mg:100mL.

[0029] The weight ratio of calcium to zinc in the calcium zinc stabilizer is 2:1.

[0030] The plasticizer is trioctyl trimellitate or dioctyl terephthalate.

[0031] Example 2

[0032] A high temperature resistant PVC composite cable material, comprising the following raw materials in parts by weight: 70 parts of PVC resin, 12 parts of mica powder, 4 parts of epoxy soybean oil, 8 parts of calcium zinc stabilizer, 3 parts of plasticizer, and 6 parts of synergistic flame retardant;

[0033] The high temperature resistant PVC composite cable material is made by the following steps:

[0034] After PVC resin, mica powder, epoxy soybean oil, calcium zinc stabilizer, plasticizer and synergistic flame retardant are mixed evenly, they are mixed in a mixer at 170°C for 6 minutes, then transferred to a flat vulcanizer and hot-pressed at a temperature of 172°C and a pressure of 110MPa, taken out and cold-pressed to obtain a high-temperature resistant PVC composite cable material.

[0035] The synergistic flame retardant is prepared by the following steps:

[0036] Step S1, adding a 15% by mass aqueous solution of tetrakis(hydroxymethyl)phosphonium sulfate to a reaction kettle, stirring at a uniform speed and adding barium hydroxide, continuing stirring for 2 hours, and then dropping a 20% by mass aqueous solution of hydrogen peroxide until the starch potassium iodide reagent turns blue, then rotary evaporating to remove the solvent, drying at 80° C. to obtain an intermediate 1, wherein the weight ratio of the tetrakis(hydroxymethyl)phosphonium sulfate to the barium hydroxide is controlled to be 5.42 g:31 g;

[0037] Step S2, adding itaconic anhydride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide into a three-necked flask, adding tetrahydrofuran, stirring magnetically and heating to 50°C, reflux reaction for 6 hours, and after the reaction, removing the solvent by rotary evaporation, washing the filter cake with ethanol and vacuum drying at 50°C to obtain intermediate 2, wherein the amount ratio of itaconic anhydride, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and tetrahydrofuran is controlled to be 5.8g:10g:100mL;

[0038] Step S3, add intermediate 1 and intermediate 2 to N, N-dimethylformamide, add p-toluenesulfonic acid, heat to 115°C, stir magnetically and react for 6 hours, remove the solvent by rotary evaporation after the reaction, and then place under vacuum drying at 75°C to obtain a synergistic flame retardant, and control the usage ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid and N, N-dimethylformamide to be 1.1g:6.2g:40mg:100mL.

[0039] The weight ratio of calcium to zinc in the calcium zinc stabilizer is 2:1.

[0040] The plasticizer is trioctyl trimellitate or dioctyl terephthalate.

[0041] Example 3

[0042] A high temperature resistant PVC composite cable material, comprising the following raw materials in parts by weight: 80 parts of PVC resin, 14 parts of mica powder, 4 parts of epoxy soybean oil, 9 parts of calcium zinc stabilizer, 4 parts of plasticizer, and 8 parts of synergistic flame retardant;

[0043] The high temperature resistant PVC composite cable material is made by the following steps:

[0044] After PVC resin, mica powder, epoxy soybean oil, calcium zinc stabilizer, plasticizer and synergistic flame retardant are mixed evenly, they are mixed in a mixer at 175°C for 8 minutes, then transferred to a flat vulcanizer and hot-pressed at a temperature of 175°C and a pressure of 120MPa, taken out and cold-pressed to obtain a high-temperature resistant PVC composite cable material.

[0045] The synergistic flame retardant is prepared by the following steps:

[0046] Step S1, adding a 15% by mass aqueous solution of tetrakis(hydroxymethyl)phosphonium sulfate to a reaction kettle, stirring at a uniform speed and adding barium hydroxide, continuing stirring for 2 hours, and then dropping a 20% by mass aqueous solution of hydrogen peroxide until the starch potassium iodide reagent turns blue, then rotary evaporating to remove the solvent, drying at 85° C. to obtain an intermediate 1, wherein the weight ratio of the tetrakis(hydroxymethyl)phosphonium sulfate to the barium hydroxide is controlled to be 5.44 g:32 g;

[0047] Step S2, adding itaconic anhydride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide into a three-necked flask, adding tetrahydrofuran, stirring magnetically and heating to 50°C, reflux reaction for 6 hours, and after the reaction, removing the solvent by rotary evaporation, washing the filter cake with ethanol and vacuum drying at 55°C to obtain intermediate 2, wherein the amount ratio of itaconic anhydride, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and tetrahydrofuran is controlled to be 6g:12g:100mL;

[0048] Step S3, adding intermediate 1 and intermediate 2 to N, N-dimethylformamide, adding p-toluenesulfonic acid, heating to 120°C, magnetically stirring and reacting for 6 hours, after the reaction is completed, removing the solvent by rotary evaporation, and then vacuum drying at 85°C to obtain a synergistic flame retardant, and controlling the usage ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid and N, N-dimethylformamide to be 1.1g:6.4g:40mg:100mL.

[0049] The weight ratio of calcium to zinc in the calcium zinc stabilizer is 2:1.

[0050] The plasticizer is trioctyl trimellitate or dioctyl terephthalate.

[0051] Example 4

[0052] A high temperature resistant PVC composite cable material, comprising the following raw materials in parts by weight: 100 parts of PVC resin, 15 parts of mica powder, 5 parts of epoxy soybean oil, 10 parts of calcium zinc stabilizer, 5 parts of plasticizer, and 10 parts of synergistic flame retardant;

[0053] The high temperature resistant PVC composite cable material is made by the following steps:

[0054] After PVC resin, mica powder, epoxy soybean oil, calcium zinc stabilizer, plasticizer and synergistic flame retardant are mixed evenly, they are mixed in a mixer at 175°C for 8 minutes, then transferred to a flat vulcanizer and hot-pressed at a temperature of 175°C and a pressure of 120MPa, taken out and cold-pressed to obtain a high-temperature resistant PVC composite cable material.

[0055] The synergistic flame retardant is prepared by the following steps:

[0056] Step S1, adding a 15% by mass aqueous solution of tetrakis(hydroxymethyl)phosphonium sulfate to a reaction kettle, stirring at a uniform speed and adding barium hydroxide, continuing stirring for 2 hours, and then dropping a 20% by mass aqueous solution of hydrogen peroxide until the starch potassium iodide reagent turns blue, then rotary evaporating to remove the solvent, drying at 85° C. to obtain an intermediate 1, wherein the weight ratio of the tetrakis(hydroxymethyl)phosphonium sulfate to the barium hydroxide is controlled to be 5.45 g:32 g;

[0057] Step S2, adding itaconic anhydride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide into a three-necked flask, adding tetrahydrofuran, stirring magnetically and heating to 50°C, reflux reaction for 6 hours, and after the reaction, removing the solvent by rotary evaporation, washing the filter cake with ethanol and vacuum drying at 55°C to obtain intermediate 2, wherein the amount ratio of itaconic anhydride, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and tetrahydrofuran is controlled to be 6g:12g:100mL;

[0058] Step S3, adding intermediate 1 and intermediate 2 to N, N-dimethylformamide, adding p-toluenesulfonic acid, heating to 120°C, magnetically stirring and reacting for 6 hours, after the reaction is completed, removing the solvent by rotary evaporation, and then placing it under vacuum and drying at 85°C to obtain a synergistic flame retardant, and controlling the usage ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid and N, N-dimethylformamide to be 1.2g:6.5g:50mg:100mL.

[0059] The weight ratio of calcium to zinc in the calcium zinc stabilizer is 2:1.

[0060] The plasticizer is trioctyl trimellitate or dioctyl terephthalate.

[0061] Comparative Example 1

[0062] Compared with Example 1, this comparative example uses DOPO as a synergistic flame retardant.

[0063] Comparative Example 2

[0064] This comparative example is a flame-retardant PVC cable material produced by a certain company on the market.

[0065] The properties of the cable materials prepared in Examples 1-4 and Comparative Examples 1-2 were tested, and the results are shown in Table 1 below:

[0066] Mechanical properties test standard: GB 1040-79.

[0067] Oxygen index test standard: GB2406-80.

[0068] Table 1

[0069] Tensile strength MPa Elongation at break % Oxygen index% Example 1 18.4 310.2 41.2 Example 2 18.5 310.5 40.8 Example 3 18.3 310.5 41.1 Example 4 18.5 310.4 40.0 Comparative Example 1 18.3 309.8 36.2 Comparative Example 2 15.2 280.5 35.8

[0070] It can be seen from Table 1 above that the cable materials prepared in Examples 1-4 of the present invention not only have excellent heat resistance, but also do not require too much inorganic flame retardant to be added, and have little effect on the mechanical properties of the organism.

[0071] 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 high temperature resistant PVC composite cable material, characterized in that: The invention comprises the following raw materials in parts by weight: 60-100 parts of PVC resin, 10-15 parts of mica powder, 3-5 parts of epoxy soybean oil, 8-10 parts of calcium zinc stabilizer, 2-5 parts of plasticizer, and 5-10 parts of synergistic flame retardant; The synergistic flame retardant is prepared by the following steps: Step S1, adding a 15% by mass aqueous solution of tetrakis(hydroxymethyl)phosphonium sulfate to a reaction kettle, stirring at a uniform speed and adding barium hydroxide, continuing stirring for 2 hours, and then dropping a 20% by mass aqueous solution of hydrogen peroxide until the starch potassium iodide reagent turns blue, then rotary evaporating to remove the solvent, and drying at 80-85° C. to obtain an intermediate 1; Step S2, adding itaconic anhydride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide into a three-necked flask, adding tetrahydrofuran, stirring magnetically and heating to 50°C, reflux for 6 hours, and after the reaction, removing the solvent by rotary evaporation, washing the filter cake with ethanol and vacuum drying at 50-55°C to obtain intermediate 2; Step S3, adding intermediate 1 and intermediate 2 to N,N-dimethylformamide, adding p-toluenesulfonic acid, heating to 110-120°C, magnetically stirring and reacting for 6 hours, after the reaction is completed, removing the solvent by rotary evaporation, and then placing it at 70-85°C and vacuum drying to obtain a synergistic flame retardant.

2. A high temperature resistant PVC composite cable material according to claim 1, characterized in that: In step S1, the weight ratio of the tetrakis(hydroxymethyl)phosphonium sulfate aqueous solution to the barium hydroxide is controlled to be 5.40-5.45 g:30-32 g.

3. A high temperature resistant PVC composite cable material according to claim 1, characterized in that: In step S2, the dosage ratio of itaconic anhydride, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and tetrahydrofuran is controlled to be 5.5-6 g:10-12 g:100 mL.

4. A high temperature resistant PVC composite cable material according to claim 1, characterized in that: In step S3, the usage ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid and N,N-dimethylformamide is controlled to be 1-1.2 g: 6-6.5 g: 30-50 mg: 100 mL.

5. A high temperature resistant PVC composite cable material according to claim 1, characterized in that: The weight ratio of calcium to zinc in the calcium zinc stabilizer is 2:

1.

6. A high temperature resistant PVC composite cable material according to claim 1, characterized in that: The plasticizer is trioctyl trimellitate or dioctyl terephthalate.

7. The method for preparing a high temperature resistant PVC composite cable material according to claim 1, characterized in that: The steps include: After uniformly mixing PVC resin, mica powder, epoxy soybean oil, calcium zinc stabilizer, plasticizer and synergistic flame retardant, use a mixer to mix at 170℃-175℃ for 5-8min, then transfer to a flat vulcanizer and hot press at a temperature between 170℃-175℃ and a pressure of 100MPa-120MPa, take out and cold press to obtain a high temperature resistant PVC composite cable material.

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