Highly flame-retardant rubber-plastic insulation material and preparation method thereof

Abstract

The application relates to the technical field of rubber and plastic materials, and discloses 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 comprises the following raw materials in parts 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 phosphorous acid-diethyl hypophosphite aluminum composite salt and expandable graphite. Through the technical scheme, the problem of insufficient flame retardancy of the rubber and plastic thermal insulation material in the related art is solved.

Description

TECHNICAL FIELD

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

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

[0003] However, the insufficient flame retardance of the rubber and plastic thermal insulation material restricts its further promotion and application in the actual application process. The base materials (such as natural rubber, nitrile rubber, polyethylene, polystyrene and the like) of the rubber and plastic thermal insulation material are mostly flammable or combustible high molecular polymers, which are prone to thermal decomposition under high temperature or in the presence of fire, and release a large amount of combustible gas (such as methane, ethane, benzene compounds and the like), and once contacting the fire source, combustion is easily caused. Meanwhile, the material combustion process is accompanied by intense heat release, and the flame propagation speed is fast, which can rapidly destroy the thermal insulation structure and cause the thermal insulation function of the equipment or building to fail.

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

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

[0006] The technical scheme of the application is as follows:

[0007] The application provides a high-flame-retardant rubber and plastic thermal insulation material, which comprises the following raw materials in parts 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 accelerator.

[0008] The flame retardant comprises ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite.

[0009] 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.

[0010] As a further technical scheme, the expandable graphite is expandable graphite loaded with zinc phenyl hypophosphite.

[0011] As a further technical solution, the preparation method of the expandable graphite loaded with zinc phenylphosphinate, comprising the following steps:

[0012] A1, phenylphosphinic acid is mixed with a solvent to obtain a phenylphosphinic acid mixture;

[0013] A2, zinc salt, solvent and expandable graphite are mixed to obtain a preliminary mixture;

[0014] A3, the phenylphosphinic acid mixture and the preliminary mixture are mixed, filtered, washed, and dried to obtain expandable graphite loaded with zinc phenylphosphinate.

[0015] In the present application, the addition of ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite loaded with zinc phenylphosphinate in the rubber and plastic insulation material improves the strength of the high flame-retardant rubber and plastic insulation material.

[0016] As a further technical solution, the mass ratio of the phenylphosphinic acid and the zinc salt is 1:1.1~1.3;

[0017] The mass ratio of the phenylphosphinic acid and the expandable graphite is 1:2~2.5.

[0018] As a further technical solution, the zinc salt includes one or both of zinc sulfate and zinc carbonate.

[0019] As a further technical solution, the solvent in steps A1 and A2 is independently water or an alcohol solvent, preferably water.

[0020] As a further technical solution, the reinforcing agent includes one or more of carbon black, talc, and calcium carbonate.

[0021] 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.

[0022] The plasticizer includes one or more of epoxy soybean oil, dioctyl phthalate, and dioctyl adipate;

[0023] The foaming agent includes foaming agent AC.

[0024] As a further technical solution, the vulcanizing agent includes sulfur;

[0025] The active agent includes zinc oxide and stearic acid.

[0026] As a further technical solution, the mass ratio of the stearic acid and the zinc oxide is 1:1.

[0027] The accelerator comprises one or more of accelerator PZ, accelerator CZ, and accelerator BZ.

[0028] In the rubber and plastic thermal insulation material, the addition of the accelerator can effectively shorten the vulcanization time, improve the production efficiency, and reduce the production cost, and can also improve the processing performance of the rubber and increase 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, etc., and is preferably one or more of accelerator PZ, accelerator CZ, and accelerator BZ.

[0029] The application further provides a preparation method of the high-flame-retardant rubber and plastic thermal insulation material.

[0030] The raw materials of the rubber and plastic thermal insulation material are mixed, extruded, vulcanized and foamed to obtain the high-flame-retardant rubber and plastic thermal insulation material.

[0031] As a further technical solution, the preparation method of the high-flame-retardant rubber and plastic thermal insulation material comprises the following steps.

[0032] S1, mixing and then densifying the raw materials of the rubber and plastic thermal insulation material except the foaming agent and the vulcanizing agent to obtain a densified rubber;

[0033] S2, opening the densified rubber to the foaming agent and the vulcanizing agent to obtain a mixed rubber;

[0034] S3, extruding, vulcanizing and foaming the mixed rubber to obtain the high-flame-retardant rubber and plastic thermal insulation material.

[0035] The working principle and beneficial effects of the application are as follows.

[0036] In the application, the ethyl phosphite-aluminum diethyl hypophosphite composite salt and the expandable graphite are used as the flame retardant, and the flame retardancy of the rubber and plastic thermal insulation material is significantly improved. The ethyl phosphite-aluminum diethyl hypophosphite composite salt can capture free radicals in the gas phase and promote carbonization in the condensed phase, and can inhibit 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 and reduce the possibility of material combustion; the ethyl phosphite-aluminum diethyl hypophosphite composite salt and the expandable graphite are synergistic, and the flame retardant performance of the rubber and plastic thermal insulation material is improved, which provides more reliable protection for the fire safety of the rubber and plastic thermal insulation material in the fields of building and industry. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0038] 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.

[0039] Example 1

[0040] The preparation method of the high flame-retardant rubber-plastic thermal insulation material comprises the following steps:

[0041] 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 banburying for 15 min to obtain a banburying rubber; the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite in a mass ratio of 1:1;

[0042] S2, the banburying rubber is subjected to open mixing with 6 parts of a foaming agent AC and 3 parts of sulfur to obtain a mixed rubber;

[0043] S3, the mixed rubber is subjected to extrusion and then sent into a foaming oven for vulcanization and foaming at a temperature of 160℃ for 3 h to obtain the high flame-retardant rubber-plastic thermal insulation material.

[0044] Example 2

[0045] The preparation method of the high flame-retardant rubber-plastic thermal insulation material comprises the following steps:

[0046] 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 banburying for 15 min to obtain a banburying rubber; the flame retardant is ethyl phosphite-diethyl aluminum hypophosphite composite salt and expandable graphite in a mass ratio of 1:1;

[0047] S2, the banburying rubber is subjected to open mixing with 2 parts of a foaming agent AC and 2 parts of sulfur to obtain a mixed rubber;

[0048] S3, extruding the rubber compound, and sending it into a foaming oven to vulcanize and foam at a temperature of 160 DEG C for 3h, to obtain the high flame-retardant rubber and plastic thermal insulation material.

[0049] Example 3

[0050] The method for preparing the high flame-retardant rubber and plastic thermal insulation material comprises the following steps:

[0051] S1, mixing 80 parts of nitrile rubber (model N230S), 20 parts of polyvinyl chloride (model SG-8), 10 parts of carbon black, 15 parts of flame retardant, 12 parts of epoxy soybean oil, 2 parts of active agent (stearic acid and zinc oxide with a mass ratio of 1:1), and 2 parts of accelerator PZ by weight, and then performing dense mixing for 15 min to obtain a rubber compound; the flame retardant is a complex salt of ethyl phosphite and diethyl aluminum hypophosphite with a mass ratio of 1:1, and expandable graphite;

[0052] S2, opening the rubber compound with 8 parts of foaming agent AC and 4 parts of sulfur to obtain a rubber compound;

[0053] S3, extruding the rubber compound, and sending it into a foaming oven to vulcanize and foam at a temperature of 160 DEG C for 3h, to obtain the high flame-retardant rubber and plastic thermal insulation material.

[0054] Example 4

[0055] The difference between this embodiment and example 3 is that the flame retardant is a complex salt of ethyl phosphite and diethyl aluminum hypophosphite with a mass ratio of 1:3, and expandable graphite.

[0056] Example 5

[0057] The difference between this embodiment and example 3 is that the flame retardant is a complex salt of ethyl phosphite and diethyl aluminum hypophosphite with a mass ratio of 1:7, and expandable graphite.

[0058] Example 6

[0059] The difference between this embodiment and example 3 is that the flame retardant is a complex salt of ethyl phosphite and diethyl aluminum hypophosphite with a mass ratio of 1:9, and expandable graphite.

[0060] Example 7

[0061] The difference between this embodiment and example 5 is that the expandable graphite is replaced by expandable graphite loaded with zinc phenyl hypophosphite.

[0062] The method for preparing the expandable graphite loaded with zinc phenyl hypophosphite comprises the following steps:

[0063] A1, mixing phenyl hypophosphoric acid with water at a mass-volume ratio of 1g:100mL to obtain a phenyl hypophosphoric acid mixture;

[0064] A2, mixing zinc sulfate heptahydrate, water and expandable graphite to obtain a primary mixture; the mass-volume ratio of zinc sulfate heptahydrate and water is 1 g: 100 mL, the mass ratio of phenyl phosphinic acid and zinc sulfate heptahydrate is 1:1.1, and the mass ratio of phenyl phosphinic acid and expandable graphite is 1:2;

[0065] A3, mixing the phenyl phosphinic acid mixture and the primary mixture, filtering, washing, and drying to obtain expandable graphite loaded with phenyl phosphinic zinc.

[0066] Example 8

[0067] The difference between this example and Example 5 is that expandable graphite is replaced by expandable graphite loaded with phenyl phosphinic zinc;

[0068] A method for preparing expandable graphite loaded with phenyl phosphinic zinc includes the following steps:

[0069] A1, mixing phenyl phosphinic acid and water at a mass-volume ratio of 1 g: 100 mL to obtain a phenyl phosphinic acid mixture;

[0070] A2, mixing zinc sulfate heptahydrate, water and expandable graphite to obtain a primary mixture; the mass-volume ratio of zinc sulfate heptahydrate and water is 1 g: 100 mL, the mass ratio of phenyl phosphinic acid and zinc sulfate heptahydrate is 1:1.3, and the mass ratio of phenyl phosphinic acid and expandable graphite is 1:2.5;

[0071] A3, mixing the phenyl phosphinic acid mixture and the primary mixture, filtering, washing, and drying to obtain expandable graphite loaded with phenyl phosphinic zinc.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 3 is that the flame retardant is expandable graphite.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 3 is that the flame retardant is ethyl phosphite-diethyl phosphinic aluminum composite salt.

[0076] Comparative Example 3

[0077] The difference between this comparative example and Example 3 is that the flame retardant is expandable graphite loaded with phenyl phosphinic zinc.

[0078] A method for preparing expandable graphite loaded with phenyl phosphinic zinc includes the following steps:

[0079] A1, mixing phenyl phosphinic acid and water at a mass-volume ratio of 1 g: 100 mL to obtain a phenyl phosphinic acid mixture;

[0080] A2, mixing zinc sulfate heptahydrate, water and expandable graphite to obtain a primary mixture; the mass-volume ratio of zinc sulfate heptahydrate and water is 1 g:100 mL, the mass ratio of phenyl hypophosphorous acid and zinc sulfate heptahydrate is 1:1.1, and the mass ratio of phenyl hypophosphorous acid and expandable graphite is 1:2;

[0081] A3, mixing the phenyl hypophosphorous acid mixture and the primary mixture, filtering, washing, and drying to obtain expandable graphite loaded with zinc phenyl hypophosphite.

[0082] Experimental Example 1

[0083] The high flame-retardant rubber and plastic insulation materials prepared in Examples 1-8 and Comparative Examples 1-3 were subjected to flame-retardant tests 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 spread in room temperature tests".

[0084] Table 1: Performance test results

[0085]

[0086] 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 ethyl phosphorous acid-diethyl aluminum hypophosphite composite salt and expandable graphite improves the flame retardancy of the high flame-retardant rubber and plastic insulation materials.

[0087] Experimental Example 2

[0088] The high flame-retardant rubber and plastic insulation materials prepared in Examples 5-8 and Comparative Examples 1-3 were subjected to strength tests according to the standard GB / T 6344-2008 "Flexible foamed polymeric materials-Determination of tensile strength and elongation at break", and the sample type was 1A sample, and the results are shown in Table 2.

[0089] Table 2: Performance test results

[0090]

[0091] Compared with Comparative Examples 1-3 and Example 5, the high flame-retardant rubber and plastic insulation materials prepared in Examples 7-8 have higher tensile strength, indicating that the addition of ethyl phosphorous acid-diethyl aluminum hypophosphite composite salt and expandable graphite loaded with zinc phenyl hypophosphite improves the strength of the high flame-retardant rubber and plastic insulation materials.

[0092] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high flame-retardant rubber-plastic thermal insulation material, characterized in that, The raw materials include the following parts by weight: 60-80 parts of nitrile rubber, 20-40 parts of polyvinyl chloride, 5-10 parts of reinforcing agent, 7-15 parts of flame retardant, 2-8 parts of foaming agent, 8-12 parts of plasticizer, 2-4 parts of vulcanizing agent, 1-2 parts of activator, and 1.5-2 parts of accelerator; The flame retardant includes ethyl phosphorous acid-diethyl aluminum hypophosphite composite salt and expandable graphite; The mass ratio of the ethyl phosphorous acid-diethyl aluminum hypophosphite composite salt to expandable graphite is 1:3~7; The expandable graphite is expandable graphite supported on zinc phenylphosphite.

2. The high flame-retardant rubber-plastic insulation material according to claim 1, characterized in that, The preparation method of the expandable graphite-supported zinc phenylphosphite includes the following steps: A1. Mix phenylphosphine with a solvent to obtain a phenylphosphine mixture; A2. Mix zinc salt, solvent and expandable graphite to obtain a preliminary mixture; A3. The phenylphosphine mixture and the initial mixture are mixed, filtered, washed, and dried to obtain expandable graphite-supported zinc phenylphosphine.

3. The high flame-retardant rubber-plastic thermal insulation material according to claim 2, characterized in that, The mass ratio of the phenylphosphine to the zinc salt is 1:1.1~1.3; The mass ratio of the phenylphosphine to expandable graphite is 1:2~2.

5.

4. The high flame-retardant rubber-plastic thermal insulation material according to claim 2, characterized in that, The zinc salt includes one or both of zinc sulfate and zinc carbonate.

5. The high flame-retardant rubber-plastic insulation material according to claim 2, characterized in that, The solvents in steps A1 and A2 each independently include water or alcohol solvents.

6. The high flame-retardant rubber-plastic thermal insulation material according to claim 1, characterized in that, The reinforcing agent includes one or more of carbon black, talc, 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.

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

8. A method for preparing a high flame-retardant rubber-plastic insulation material, used to prepare the high flame-retardant rubber-plastic insulation material according to any one of claims 1 to 7, characterized in that, Includes the following steps: The raw materials for rubber and plastic insulation materials are mixed, extruded, vulcanized and foamed to obtain high flame-retardant rubber and plastic insulation materials.

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