High-flame-retardant rubber and plastic thermal insulation material and preparation method thereof

Abstract

The invention relates to the technical field of rubber and plastic materials, and provides a high-flame-retardant rubber and plastic thermal insulation material and a preparation method thereof.The high-flame-retardant rubber and plastic thermal insulation material is prepared from, by weight, 60-80 parts of nitrile rubber, 20-40 parts of polyvinyl chloride, 5-10 parts of a reinforcing agent, 7-15 parts of a flame retardant, 2-8 parts of a foaming agent, 8-12 parts of a plasticizer, 2-4 parts of a vulcanizing agent, 1-2 parts of an active agent and 1.5-2 parts of an accelerant; the flame retardant is prepared from ethyl phosphorous acid-diethyl aluminum hypophosphite composite salt and expandable graphite. According to the technical scheme, the problem of insufficient flame retardance of rubber and plastic thermal insulation materials in related technologies is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber and plastic materials, in particular to a high-flame-retardant rubber and plastic insulation material and a preparation method thereof. BACKGROUND

[0002] The rubber and plastic insulation material is a functional material prepared by mixing, foaming and molding rubber and plastic as main binders, fillers, plasticizers, stabilizers and other additives. It has been widely used in many fields such as building heating, ventilation and air conditioning systems, pipeline insulation, and transportation equipment insulation due to its excellent heat insulation performance, low density and convenient construction.

[0003] However, the insufficient flame retardant performance of the rubber and plastic insulation material restricts its further promotion and application in actual application. The base material of the rubber and plastic insulation material (such as natural rubber, nitrile rubber, polyethylene, polystyrene, etc.) is mostly flammable or combustible polymer, which is easy to decompose at high temperature or when exposed to fire, releasing a large amount of flammable gas (such as methane, ethane, benzene compounds, etc.), and once exposed to fire, it is easy to cause combustion. At the same time, the material combustion process is accompanied by intense heat release, and the flame propagation speed is fast, which can quickly destroy the insulation structure and cause the insulation function of the equipment or building to fail.

[0004] Therefore, it is urgent to develop a rubber and plastic insulation material with excellent flame retardant performance to broaden the application of rubber and plastic insulation material. SUMMARY

[0005] The present application provides a high-flame-retardant rubber and plastic insulation material and a preparation method thereof, which solves the problem of insufficient flame retardant performance of the rubber and plastic insulation material in the related art.

[0006] The technical scheme of the present application is as follows: The present application provides a high-flame-retardant rubber and plastic insulation material, which comprises the following raw materials by weight: nitrile rubber 60-80 parts, polyvinyl chloride 20-40 parts, reinforcing agent 5-10 parts, flame retardant 7-15 parts, foaming agent 2-8 parts, plasticizer 8-12 parts, vulcanizing agent 2-4 parts, active agent 1-2 parts, and accelerator 1.5-2 parts. The flame retardant comprises ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite.

[0007] As a further technical scheme, the mass ratio of the ethyl phosphite-diethyl aluminum hypophosphite composite salt and the expandable graphite is 1:3-7.

[0008] As a further technical scheme, the expandable graphite is expandable graphite loaded with zinc phenyl hypophosphite.

[0009] As a further technical scheme, the preparation method of the expandable graphite loaded with zinc phenyl hypophosphite comprises the following steps: A1, mixing phenylphosphinic acid with a solvent to obtain a phenylphosphinic acid mixture; A2, mixing a zinc salt, a solvent and expandable graphite to obtain a primary mixture; A3, mixing the phenylphosphinic acid mixture and the primary mixture, filtering, washing, and drying to obtain expandable graphite loaded zinc phenylphosphinate.

[0010] In the present application, the addition of ethyl phosphite-diethyl aluminum phosphinate composite salt and expandable graphite loaded zinc phenylphosphinate in the rubber and plastic insulation material improves the strength of the high flame-retardant rubber and plastic insulation material.

[0011] As a further technical solution, the mass ratio of the phenylphosphinic acid and the zinc salt is 1:1.1~1.3; The mass ratio of the phenylphosphinic acid and the expandable graphite is 1:2~2.5.

[0012] As a further technical solution, the zinc salt includes one or both of zinc sulfate and zinc carbonate.

[0013] As a further technical solution, the solvent in steps A1 and A2 each independently includes water or an alcohol solvent, preferably water.

[0014] As a further technical solution, the reinforcing agent includes one or more of carbon black, talc, and calcium carbonate.

[0015] In the rubber and plastic insulation material, carbon black, talc, calcium carbonate, etc. as a reinforcing agent can ensure the strength of the rubber and plastic material, improve the mechanical properties of the rubber and plastic material, and make the rubber and plastic insulation material maintain mechanical stability in different environments. The reinforcing agent can be carbon black, talc, calcium carbonate, white carbon black, wollastonite, magnesium carbonate, etc., preferably one or more of carbon black, talc, and calcium carbonate.

[0016] The plasticizer includes one or more of epoxidized soybean oil, dioctyl phthalate, and dioctyl adipate; The foaming agent includes foaming agent AC.

[0017] As a further technical solution, the vulcanizing agent includes sulfur; The active agent includes zinc oxide and stearic acid.

[0018] As a further technical solution, the mass ratio of the stearic acid and the zinc oxide is 1:1.

[0019] The accelerator includes one or more of accelerator PZ, accelerator CZ, and accelerator BZ.

[0020] The addition of the accelerator in the rubber-plastic thermal insulation material can effectively shorten the vulcanization time, improve the production efficiency, reduce the production cost, improve the processing performance of the rubber, and improve the crosslinking density of the rubber, thereby ensuring the thermal insulation performance and the flame retardant performance of the material, and the accelerator can be accelerator PZ, accelerator CZ, accelerator BZ, accelerator TMTD, accelerator TMTM, or the like, and preferably one or more of accelerator PZ, accelerator CZ and accelerator BZ.

[0021] The application further provides a preparation method of the high-flame-retardant rubber-plastic thermal insulation material. The raw materials of the rubber-plastic thermal insulation material are mixed, extruded, vulcanized and foamed to obtain the high-flame-retardant rubber-plastic thermal insulation material.

[0022] As a further technical solution, the preparation method of the high-flame-retardant rubber-plastic thermal insulation material comprises the following steps. S1, mixing and then densifying the raw materials of the rubber-plastic thermal insulation material except the foaming agent and the vulcanizing agent to obtain a densified rubber; S2, opening the densified rubber to obtain a mixed rubber by mixing the densified rubber with the foaming agent and the vulcanizing agent; S3, extruding, vulcanizing and foaming the mixed rubber to obtain the high-flame-retardant rubber-plastic thermal insulation material.

[0023] The working principle and beneficial effects of the application are as follows. In the application, ethyl phosphite-aluminum diethyl hypophosphite composite salt and expandable graphite are used as the flame retardant to significantly improve the flame retardancy of the rubber-plastic thermal insulation material. The ethyl phosphite-aluminum diethyl hypophosphite composite salt can capture free radicals in the gas phase and promote carbonization in the condensed phase, thereby inhibiting combustion from two aspects of the source and the surface. The heat insulation barrier layer formed by the expansion of the expandable graphite can effectively block heat and oxygen, thereby reducing the possibility of material combustion. The ethyl phosphite-aluminum diethyl hypophosphite composite salt and the expandable graphite are synergistic, thereby improving the flame retardant performance of the rubber-plastic thermal insulation material, which provides more reliable protection for the fire safety of the rubber-plastic thermal insulation material in the fields of building and industry. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0025] In the following examples and comparative examples, the ethyl phosphite-diethyl aluminum hypophosphite composite salt is Model MADP8900, CAS No. 2725791-55-7, purchased from Weihai Hailun New Material Technology Co., Ltd.; the average particle size of the expandable graphite is 50 μm; and the carbon black is Model N330.

[0026] Example 1 The preparation method of the high flame-retardant rubber-plastic insulation material comprises the following steps: S1, 70 parts of nitrile rubber (Model N230S), 30 parts of polyvinyl chloride (Model SG-8), 6 parts of carbon black, 9 parts of a flame retardant, 10 parts of epoxy soybean oil, 1 part of an active agent (stearic acid and zinc oxide in a mass ratio of 1:1), and 2 parts of an accelerator PZ are mixed and then subjected to Banbury mixing for 15 min to obtain a Banbury mixed rubber; the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite in a mass ratio of 1:1; S2, the Banbury mixed rubber is subjected to open mixing with 6 parts of a foaming agent AC and 3 parts of sulfur to obtain a mixed rubber; S3, the mixed rubber is subjected to extrusion and then fed into a foaming oven for vulcanization and foaming at a temperature of 160℃ for 3 h to obtain the high flame-retardant rubber-plastic insulation material.

[0027] Example 2 The preparation method of the high flame-retardant rubber-plastic insulation material comprises the following steps: S1, 60 parts of nitrile rubber (Model N230S), 40 parts of polyvinyl chloride (Model SG-8), 5 parts of carbon black, 7 parts of a flame retardant, 8 parts of epoxy soybean oil, 1 part of an active agent (stearic acid and zinc oxide in a mass ratio of 1:1), and 1.5 parts of an accelerator PZ are mixed and then subjected to Banbury mixing for 15 min to obtain a Banbury mixed rubber; the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite in a mass ratio of 1:1; S2, the Banbury mixed rubber is subjected to open mixing with 2 parts of a foaming agent AC and 2 parts of sulfur to obtain a mixed rubber; S3, the mixed rubber is subjected to extrusion and then fed into a foaming oven for vulcanization and foaming at a temperature of 160℃ for 3 h to obtain the high flame-retardant rubber-plastic insulation material.

[0028] Example 3 The preparation method of the high flame-retardant rubber-plastic insulation material comprises the following steps: S1, 80 parts of nitrile rubber (Model N230S), 20 parts of polyvinyl chloride (Model SG-8), 10 parts of carbon black, 15 parts of a flame retardant, 12 parts of epoxy soybean oil, 2 parts of an active agent (stearic acid and zinc oxide in a mass ratio of 1:1), and 2 parts of an accelerator PZ are mixed and then subjected to Banbury mixing for 15 min to obtain a Banbury mixed rubber; the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite in a mass ratio of 1:1; S2, the mixing chamber glue with 8 parts of foaming agent AC, 4 parts of sulfur, get the rubber; S3, the mixing chamber glue extrusion, send into the foaming furnace with 160 ℃ temperature vulcanization and foaming 3h, get high flame retardant rubber plastic insulation material.

[0029] Example 4 The difference between this embodiment and example 3 is only that the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt, expandable graphite with mass ratio of 1:3.

[0030] Example 5 The difference between this embodiment and example 3 is only that the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt, expandable graphite with mass ratio of 1:7.

[0031] Example 6 The difference between this embodiment and example 3 is only that the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt, expandable graphite with mass ratio of 1:9.

[0032] Example 7 The difference between this embodiment and example 5 is only that the expandable graphite is replaced by expandable graphite loaded with zinc phenyl hypophosphite; The preparation method of expandable graphite loaded with zinc phenyl hypophosphite comprises the following steps: A1, the phenyl hypophosphoric acid and water are mixed with mass volume ratio of 1g:100mL to obtain phenyl hypophosphoric acid mixed solution; A2, the zinc sulfate heptahydrate, water and expandable graphite are mixed to obtain a primary mixture; the mass volume ratio of zinc sulfate heptahydrate and water is 1g:100mL, the mass ratio of phenyl hypophosphoric acid and zinc sulfate heptahydrate is 1:1.1, and the mass ratio of phenyl hypophosphoric acid and expandable graphite is 1:2; A3, the phenyl hypophosphoric acid mixed solution and the primary mixture are mixed, filtered, washed and dried to obtain expandable graphite loaded with zinc phenyl hypophosphite.

[0033] Example 8 The difference between this embodiment and example 5 is only that the expandable graphite is replaced by expandable graphite loaded with zinc phenyl hypophosphite; The preparation method of expandable graphite loaded with zinc phenyl hypophosphite comprises the following steps: A1, the phenyl hypophosphoric acid and water are mixed with mass volume ratio of 1g:100mL to obtain phenyl hypophosphoric acid mixed solution; A2, the zinc sulfate heptahydrate, water and expandable graphite are mixed to obtain a primary mixture; the mass volume ratio of zinc sulfate heptahydrate and water is 1g:100mL, the mass ratio of phenyl hypophosphoric acid and zinc sulfate heptahydrate is 1:1.3, and the mass ratio of phenyl hypophosphoric acid and expandable graphite is 1:2.5; A3, mixing the phenylphosphinic acid mixture and the initial mixture, filtering, washing, drying to obtain the expandable graphite loaded zinc phenylphosphinate.

[0034] Comparative Example 1 The difference between the present comparative example and Example 3 is that the flame retardant is expandable graphite.

[0035] Comparative Example 2 The difference between the present comparative example and Example 3 is that the flame retardant is ethylphosphorous acid-diethyl aluminum hypophosphite composite salt.

[0036] Comparative Example 3 The difference between the present comparative example and Example 3 is that the flame retardant is expandable graphite loaded zinc phenylphosphinate.

[0037] The method for preparing expandable graphite loaded zinc phenylphosphinate comprises the following steps: A1, mixing phenylphosphinic acid with water in a mass-volume ratio of 1g:100mL to obtain a phenylphosphinic acid mixture; A2, mixing zinc sulfate heptahydrate, water and expandable graphite to obtain an initial mixture; the mass-volume ratio of zinc sulfate heptahydrate and water is 1g:100mL, the mass ratio of phenylphosphinic acid and zinc sulfate heptahydrate is 1:1.1, and the mass ratio of phenylphosphinic acid and expandable graphite is 1:2; A3, mixing the phenylphosphinic acid mixture and the initial mixture, filtering, washing, drying to obtain the expandable graphite loaded zinc phenylphosphinate.

[0038] Experimental Example 1 According to the standard GB / T 2406.2-2009 “Plastics-Determination of the burning behavior of plastics-Part 2: Guidance on the measurement of flame characteristics-Test methods”, the high flame-retardant rubber and plastic insulation materials prepared in Examples 1-8 and Comparative Examples 1-3 were tested for flame retardancy, and the results are shown in Table 1 below.

[0039] Table 1 Performance test results

[0040] Compared with Comparative Examples 1-3, the high flame-retardant rubber and plastic insulation materials prepared in Examples 1-8 have higher oxygen index, indicating that the addition of ethylphosphorous acid-diethyl aluminum hypophosphite composite salt and expandable graphite improves the flame retardancy of the high flame-retardant rubber and plastic insulation materials.

[0041] Experimental Example 2 According to the standard GB / T 6344-2008 “Soft foam polymeric materials-Determination of tensile strength and elongation at break”, the high flame-retardant rubber and plastic insulation materials prepared in Examples 5-8 and Comparative Examples 1-3 were tested for strength, and the sample type was 1A sample, and the results are shown in Table 2 below.

[0042] Table 2 Performance test results

[0043] Compared with Comparative Examples 1-3 and Example 5, the tensile strength of the high flame-retardant rubber-plastic insulation material prepared in Examples 7-8 is higher, indicating that the addition of ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite loaded zinc phenyl hypophosphite improves the strength of the high flame-retardant rubber-plastic insulation material.

[0044] The above only is the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high flame retardant rubber plastic insulation material, characterized in that, The raw materials include the following weight parts: butyronitrile rubber 60-80 parts, polyvinyl chloride 20-40 parts, reinforcing agent 5-10 parts, flame retardant 7-15 parts, foaming agent 2-8 parts, plasticizer 8-12 parts, vulcanizing agent 2-4 parts, active agent 1-2 parts, accelerator 1.5-2 parts; The flame retardant includes ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite.

2. A high flame retardant rubber plastic insulation material according to claim 1, characterized in that, The mass ratio of the ethyl phosphite-diethyl aluminum hypophosphite composite salt and the expandable graphite is 1:3-7.

3. A high flame retardant rubber plastic insulation material according to claim 1, characterized in that, The expandable graphite is expandable graphite loaded with zinc phenyl hypophosphite.

4. A high flame retardant rubber and plastic insulation material according to claim 3, characterized in that, The preparation method of the expandable graphite loaded with zinc phenyl hypophosphite includes the following steps: A1, mixing phenyl hypophosphoric acid with a solvent to obtain a phenyl hypophosphoric acid mixture; A2, mixing zinc salt, solvent and expandable graphite to obtain a preliminary mixture; A3, mixing the phenyl hypophosphoric acid mixture and the preliminary mixture, filtering, washing, and drying to obtain expandable graphite loaded with zinc phenyl hypophosphite.

5. A high flame retardant rubber plastic insulation material according to claim 4, characterized in that, The mass ratio of the phenyl hypophosphoric acid and the zinc salt is 1:1.1-1.3; The mass ratio of the phenyl hypophosphoric acid and the expandable graphite is 1:2-2.

5.

6. A high flame retardant rubber plastic insulation material according to claim 4, characterized in that, The zinc salt includes one or both of zinc sulfate and zinc carbonate.

7. A high flame retardant rubber plastic insulation material according to claim 4, wherein The solvent in step A1 and step A2 each independently includes water or an alcohol solvent.

8. A high flame retardant rubber plastic insulation material according to claim 1, characterized in that, The reinforcing agent includes one or more of carbon black, talcum powder, and calcium carbonate; The plasticizer includes one or more of epoxidized soybean oil, dioctyl phthalate, and dioctyl adipate; The foaming agent includes foaming agent AC.

9. A high flame retardant rubber plastic insulation material according to claim 1, characterized in that, The vulcanizing agent includes sulfur; The active agent includes zinc oxide and stearic acid; The accelerator includes one or more of accelerator PZ, accelerator CZ, and accelerator BZ.

10. A method for preparing a high flame-retardant rubber-plastic thermal insulation material, for preparing the high flame-retardant rubber-plastic thermal insulation material according to any one of claims 1-9, characterized in that, The method includes the following steps: Mixing the raw materials of the rubber and plastic insulation material, extruding, vulcanizing and foaming to obtain a high flame-retardant rubber and plastic insulation material.

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