A flame-retardant rubber hose for automobiles and its preparation method

Abstract

The present invention discloses a flame-retardant rubber hose for automobiles and its preparation method, which relates to the technical field of automotive parts. In the present invention, mica is modified by a silane coupling agent, and with the assistance of a ball milling process, chemical and physical adsorption between mica and the active groups on the silane molecules is promoted, and a grafting reaction of a cyclotriphosphazene derivative occurs on the surface of mica through the silane coupling agent, thereby indirectly enhancing the mechanical properties of the rubber and enabling the matrix to achieve strong flame-retardant properties. Then, as a flame retardant, it is blended with silicone rubber, potassium oxide, and polydiphenylsiloxane. Under high-temperature combustion conditions, the potassium oxide therein plays a connecting role to form a hard ceramic phase in the matrix, thereby enhancing the flame retardancy and high-temperature resistance. Finally, irradiation treatment is carried out, and under vacuum conditions, hydrogen in side groups such as phenyl and methyl in the matrix is extracted to generate benzene, thereby enhancing the high-temperature resistance and mechanical properties of the matrix.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle parts, and particularly to a flame-retardant rubber hose for automobiles and a preparation method thereof. Background Art

[0002] High speed, safety, comfort, energy conservation, and environmental protection are the goals pursued in contemporary automotive performance. Rubber hoses for automobiles are mainly used in three major parts: the chassis, engine, and body, including rubber hoses used in seven systems: oil transportation, gas transportation, drive, control, braking, cooling, and heating.

[0003] Rubber generally can only withstand temperatures of about 200°C. Its own oxygen index is relatively low, and it will produce a large amount of black smoke when burning, with a large amount of smoke. Because rubber contains rich organic components, such as methyl, vinyl, etc., these organic substances will produce a large amount of smoke when burning. The combustion temperature of rubber is relatively high, and a large amount of heat will be released during combustion. Therefore, obvious flames will be generated during the combustion process. At the same time, the combustion speed of rubber is relatively fast, and the combustion surface is relatively flat. The combustion products of rubber mainly include carbon monoxide, nitrogen oxides, etc. These products will cause certain pollution to the environment during the combustion process, especially some toxic gases, which will pose a hazard to human health. Rubber is prone to the phenomenon of dripping during combustion, and these drippings may lead to the spread of fire and increase the risk of fire. Therefore, it is particularly necessary to prepare a flame-retardant rubber hose for automobiles. Summary of the Invention

[0004] The purpose of the present invention is to provide a flame-retardant rubber hose for automobiles and a preparation method thereof to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A flame-retardant rubber hose for automobiles, which is prepared by blending a flame retardant, silicone rubber, potassium oxide, and polydiphenylsiloxane.

[0006] Further, the flame retardant is prepared by ball milling mica, a silane coupling agent, and a cyclotriphosphazene derivative.

[0007] Further, a preparation method of a flame-retardant rubber hose for automobiles includes the following preparation steps:

[0008] (1) Mix a silane coupling agent, deionized water, and absolute ethanol, stir at 20 - 50°C and 50 - 120 rpm for 10 - 40 min, adjust the pH of the solution to 4 - 5 with acetic acid, add mica powder, cool to room temperature, perform ball milling for 20 - 40 min, add a cyclotriphosphazene derivative, ball mill again for 30 - 70 min, wash with deionized water 3 - 8 times, and dry at 50 - 90°C for 4 - 8 h to obtain the flame retardant;

[0009] (2) Wrap the silicone rubber around the two rollers with a roll gap of 2 - 4 mm. Add polydiphenylsiloxane and hydroxyl silicone oil in sequence for kneading. The temperature is 60 °C and the time is 10 - 20 min. Then adjust the roll gap to 1 - 2 mm and the temperature to 150 °C. Add potassium oxide and flame retardant and knead for 20 - 50 min. After extrusion molding, the extrusion temperature is 180 °C. Under the condition of a vacuum degree of 10 -4 Pa, perform electron beam irradiation treatment to obtain a flame-retardant rubber hose for automobiles.

[0010] Further, the silane coupling agent described in step (1) is vinyltriethoxysilane.

[0011] Further, the cyclotriphosphazene derivative described in step (1) is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0012] Further, the process parameters of the ball milling in step (1): The ball milling medium is zirconium silicate, the ball-to-material ratio is 4 - 10:1, and the rotation speed is 800 - 1350 rpm.

[0013] Further, the mass ratio of the silane coupling agent, deionized water, absolute ethanol, mica powder, and cyclotriphosphazene derivative described in step (1) is 1:1:10 - 20:1 - 3:0.5 - 1.

[0014] Further, the silicone rubber described in step (2) is methyl vinyl silicone rubber.

[0015] Further, the process parameters of the electron beam irradiation in step (2): The irradiation dose is 40 - 160 kGy.

[0016] Further, the mass ratio of the silicone rubber, polydiphenylsiloxane, hydroxyl silicone oil, potassium oxide, and flame retardant described in step (2) is 100:5 - 10:1 - 5:20:20 - 40.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] The present invention modifies mica with a silane coupling agent. With the assistance of a ball milling process, the number of chemical reaction sites on the mica surface is increased, and its activity is enhanced, thereby promoting chemical and physical adsorption between the mica and the active groups on the silane molecule. Subsequently, a grafting reaction of the cyclotriphosphazene derivative occurs on the mica surface through the silane coupling agent. Under the action of mechanical force, the binding force between the cyclotriphosphazene derivative and the mica is greatly enhanced, showing an intercalation effect, improving the stability of both, and at the same time enhancing the dispersibility of the mica in the rubber matrix, thereby indirectly enhancing the mechanical properties of the rubber and enabling the matrix to achieve strong flame retardancy. Then, as a flame retardant, it is blended with silicone rubber, potassium oxide, and polydiphenylsiloxane. Under a high-temperature combustion state, potassium oxide is melted and fills between the mica particles and the silica powder formed by the high-temperature degradation of the silicone rubber matrix, playing a connecting role, and finally forming a dense, continuous, and hard ceramic phase, thereby enhancing the flame retardancy and high-temperature resistance of the matrix. Finally, irradiation treatment is carried out. Under vacuum conditions, hydrogen in side groups such as phenyl and methyl in the matrix is extracted to generate benzene, and a subsequent chain intramolecular cyclization reaction is initiated under the hydrogenated groups, enhancing the stability of the matrix structure, thereby improving the high-temperature resistance and mechanical properties of the rubber. Detailed implementation manners

[0019] The following will describe clearly and completely the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] In order to more clearly illustrate the method provided by the present invention, the following embodiments are used for detailed description. The test methods for each index of the flame-retardant rubber hose for automobiles manufactured in the following embodiments are as follows:

[0021] Mechanical properties: Samples of the same size from the examples and the comparative examples are taken and their tensile strength is tested with reference to GB / T528. After heat aging treatment, their tensile strength is tested again.

[0022] Flame retardancy: Samples of the same size from the examples and the comparative examples are taken and the limiting oxygen index (LOI) is tested in accordance with GB / T2406.2.

[0023] Example 1

[0024] (1) Mix vinyltriethoxysilane, deionized water, and absolute ethanol, stir at 20 °C and 50 rpm for 10 min, adjust the pH of the solution to 4 with acetic acid, add mica powder, cool to room temperature, and perform ball milling. The process parameters are as follows: the ball milling medium is zirconium silicate, the ball-to-material ratio is 4:1, the rotation speed is 800 rpm, and the time is 20 min. Add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and ball mill again for 30 min. Wash with deionized water 3 times and dry at 50 °C for 4 h to obtain the flame retardant. The mass ratio of vinyltriethoxysilane, deionized water, absolute ethanol, mica powder, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:1:10:1:0.5;

[0025] (2) Wrap methyl vinyl silicone rubber on a two-roll mill with a roll gap of 2 mm, and sequentially add polydiphenylsiloxane and hydroxy silicone oil for mixing. The temperature is 60 °C and the time is 10 min. Then adjust the roll gap to 1 mm and the temperature to 150 °C, add potassium oxide and the flame retardant, and mix for 20 min. After extrusion molding, the extrusion temperature is 180 °C, and under the condition of a vacuum of 10 -4 Pa, perform electron beam irradiation treatment with an irradiation dose of 40 kGy to obtain a flame retardant rubber hose for automobiles. The mass ratio of methyl vinyl silicone rubber, polydiphenylsiloxane, hydroxy silicone oil, potassium oxide, and the flame retardant is 100:5:1:20:20.

[0026] Example 2

[0027] (1) Mix vinyltriethoxysilane, deionized water, and absolute ethanol, stir at 35 °C and 85 rpm for 25 min, adjust the pH of the solution to 4.5 with acetic acid, add mica powder, cool to room temperature, and perform ball milling. The process parameters are as follows: the ball milling medium is zirconium silicate, the ball-to-material ratio is 7:1, the rotation speed is 1000 rpm, and the time is 30 min. Add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and ball mill again for 50 min. Wash with deionized water 6 times and dry at 70 °C for 6 h to obtain the flame retardant. The mass ratio of vinyltriethoxysilane, deionized water, absolute ethanol, mica powder, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:1:15:2:0.75;

[0028] (2) Wrap methyl vinyl silicone rubber on a two-roll mill with a roll gap of 3 mm, and sequentially add polydiphenylsiloxane and hydroxy silicone oil for mixing. The temperature is 60 °C and the time is 15 min. Then adjust the roll gap to 1.5 mm and the temperature to 150 °C, add potassium oxide and the flame retardant, and mix for 35 min. After extrusion molding, the extrusion temperature is 180 °C, and under the condition of a vacuum of 10 -4Under the condition of 10 Pa, perform electron beam irradiation treatment with an irradiation dose of 100 kGy to obtain a flame-retardant rubber hose for automobiles; the mass ratio of the methyl vinyl silicone rubber, polydiphenyl siloxane, hydroxy silicone oil, potassium oxide, and flame retardant is 100:7.5:3:20:30.

[0029] Example 3

[0030] (1) Mix vinyltriethoxysilane, deionized water, and absolute ethanol, stir at 50 °C and 120 rpm for 40 min, adjust the pH of the solution to 5 with acetic acid, add mica powder, cool to room temperature, and perform ball milling treatment. The process parameters are as follows: the ball milling medium is zirconium silicate, the ball-to-material ratio is 10:1, the rotation speed is 1350 rpm, and the time is 40 min. Add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and ball mill for another 70 min. Wash 8 times with deionized water and dry at 90 °C for 8 h to obtain the flame retardant; the mass ratio of vinyltriethoxysilane, deionized water, absolute ethanol, mica powder, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:1:20:3:1.

[0031] (2) Wrap the methyl vinyl silicone rubber around the two-roll mill with a roll gap of 4 mm, sequentially add polydiphenyl siloxane and hydroxy silicone oil for mixing, at a temperature of 60 °C for 20 min, then adjust the roll gap to 2 mm and the temperature to 150 °C, add potassium oxide and the flame retardant, mix for 50 min, and perform extrusion molding at an extrusion temperature of 180 °C. Under the condition of a vacuum degree of 10 -4 Pa, perform electron beam irradiation treatment with an irradiation dose of 160 kGy to obtain a flame-retardant rubber hose for automobiles; the mass ratio of the methyl vinyl silicone rubber, polydiphenyl siloxane, hydroxy silicone oil, potassium oxide, and flame retardant is 100:10:5:20:40.

[0032] Comparative Example 1

[0033] The difference between Comparative Example 1 and Example 2 lies in step (1). Modify step (1) as follows: Mix vinyltriethoxysilane, deionized water, and absolute ethanol, stir at 35 °C and 85 rpm for 25 min, adjust the pH of the solution to 4.5 with acetic acid, add mica powder, cool to room temperature, and perform ball milling treatment. The process parameters are as follows: the ball milling medium is zirconium silicate, the ball-to-material ratio is 7:1, the rotation speed is 1000 rpm, and the time is 30 min. Wash 6 times with deionized water and dry at 70 °C for 6 h to obtain the flame retardant; the mass ratio of vinyltriethoxysilane, deionized water, absolute ethanol, and mica powder is 1:1:15:2. The remaining steps are the same as those in Example 2.

[0034] Comparative Example 2

[0035] The difference between Comparative Example 2 and Example 2 is that step (1) is absent, and step (2) is changed to: Wrap methyl vinyl silicone rubber around two rollers with a roll gap of 3 mm, and sequentially add polydiphenylsiloxane and hydroxyl silicone oil for kneading at a temperature of 60 °C for 15 min. Then adjust the roll gap to 1.5 mm and the temperature to 150 °C, and add potassium oxide, mica powder, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and knead for 35 min. After extrusion molding at an extrusion temperature of 180 °C, under the condition of a vacuum degree of 10 -4 Pa, perform electron beam irradiation treatment with an irradiation dose of 100 kGy to obtain a flame-retardant rubber hose for automobiles; the mass ratio of the methyl vinyl silicone rubber, polydiphenylsiloxane, hydroxyl silicone oil, potassium oxide, mica powder, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:7.5:3:20:20:10; the remaining steps are the same as those in Example 2.

[0036] Comparative Example 3

[0037] The difference between Comparative Example 3 and Example 2 is that step (2) is different. Step (2) is changed to: Wrap methyl vinyl silicone rubber around two rollers with a roll gap of 3 mm, and sequentially add polydiphenylsiloxane and hydroxyl silicone oil for kneading at a temperature of 60 °C for 15 min. Then adjust the roll gap to 1.5 mm and the temperature to 150 °C, and add a flame retardant, and knead for 35 min. After extrusion molding at an extrusion temperature of 180 °C, under the condition of a vacuum degree of 10 -4 Pa, perform electron beam irradiation treatment with an irradiation dose of 100 kGy to obtain a flame-retardant rubber hose for automobiles; the mass ratio of the methyl vinyl silicone rubber, polydiphenylsiloxane, hydroxyl silicone oil, and flame retardant is 100:7.5:3:30; the remaining steps are the same as those in Example 2.

[0038] Comparative Example 4

[0039] The difference between Comparative Example 4 and Example 2 is that step (2) is different. Step (2) is changed to: Wrap methyl vinyl silicone rubber around two rollers with a roll gap of 3 mm, and sequentially add polydiphenylsiloxane and hydroxyl silicone oil for kneading at a temperature of 60 °C for 15 min. Then adjust the roll gap to 1.5 mm and the temperature to 150 °C, and add potassium oxide and a flame retardant, and knead for 35 min. After extrusion molding at an extrusion temperature of 180 °C, obtain a flame-retardant rubber hose for automobiles; the mass ratio of the methyl vinyl silicone rubber, polydiphenylsiloxane, hydroxyl silicone oil, potassium oxide, and flame retardant is 100:7.5:3:20:30; the remaining steps are the same as those in Example 2.

[0040] Effect Example

[0041] The performance analysis results of the flame-retardant rubber hoses for automobiles using Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention are given in Table 1 below.

[0042] Table 1

[0043]

[0044]

[0045] From the comparison of the experimental data of the examples and comparative examples in Table 1, it can be found that in the present invention, mica is modified by a silane coupling agent, and with the assistance of the ball milling process, the surface activity of mica is improved, and the chemical and physical adsorption of mica and the silane is promoted. Then, through the silane coupling agent, a grafting reaction of the cyclotriphosphazene derivative occurs on the mica surface, and under the action of mechanical force, the binding force between the cyclotriphosphazene derivative and mica is enhanced, the stability of the two is improved, and at the same time, the dispersibility of mica in the rubber matrix is enhanced, thereby enhancing the mechanical properties of the base tube. Then, as a flame retardant, it is blended with silicone rubber, potassium oxide, and polydiphenylsiloxane. At high temperatures, the molten potassium oxide plays a connecting role in the matrix and fills between the mica particles and the silica powder formed by the high-temperature degradation of the silicone rubber matrix, thereby enhancing the flame retardancy and high-temperature resistance. Finally, irradiation treatment is carried out. Under vacuum conditions, hydrogen in side groups such as phenyl and methyl in the matrix is extracted to generate benzene, enhancing the stability of the matrix structure, thereby improving the high-temperature resistance and mechanical properties of the rubber.

[0046] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claimed rights.

Claims

1. A flame-retardant rubber hose for automobiles, characterized in that, It includes the following preparation steps: (1) Mix a silane coupling agent, deionized water, and absolute ethanol, stir at 20 - 50°C and 50 - 120 rpm for 10 - 40 min, adjust the pH of the solution to 4 - 5 with acetic acid, add mica powder, cool to room temperature, carry out ball milling for 20 - 40 min, add a cyclotriphosphazene derivative, ball mill again for 30 - 70 min, wash with deionized water 3 - 8 times, and dry at 50 - 90°C for 4 - 8 h to obtain a flame retardant; the cyclotriphosphazene derivative is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; (2)Wrap the silicone rubber around the two-roll mill with a roll gap of 2 - 4 mm. Add polydiphenylsiloxane and hydroxyl silicone oil in sequence for mixing. The temperature is 60 °C and the time is 10 - 20 min. Then adjust the roll gap to 1 - 2 mm and the temperature to 150 °C. Add potassium oxide and flame retardant and mix for 20 - 50 min. After extrusion molding, the extrusion temperature is 180 °C. Under the condition of a vacuum degree of 10 -4 Pa, carry out electron beam irradiation treatment to obtain a flame-retardant rubber hose for automobiles.

2. The flame-retardant rubber hose for automobiles according to claim 1, wherein, The silane coupling agent in step (1) is vinyltriethoxysilane.

3. The flame-retardant rubber hose for automobile according to claim 1, characterized in that, The process parameters of the ball milling in step (1): the ball milling medium is zirconium silicate, the ball-to-material ratio is 4 - 10:1, and the rotation speed is 800 - 1350 rpm.

4. A flame-retardant rubber hose for automobiles according to claim 1, characterized in that, The mass ratio of the silane coupling agent, deionized water, absolute ethanol, mica powder, and cyclotriphosphazene derivative in step (1) is 1:1:10 - 20:1 - 3:0.5 - 1.

5. A flame-retardant rubber hose for automobiles according to claim 1, characterized in that, The silicone rubber in step (2) is methyl vinyl silicone rubber.

6. The flame-retardant rubber hose for automobiles according to claim 1, characterized in that, The process parameters of the electron beam irradiation in step (2): the irradiation dose is 40 - 160 kGy.

7. A flame-retardant rubber hose for automobiles according to claim 1, characterized in that, The mass ratio of the silicone rubber, polydiphenylsiloxane, hydroxyl silicone oil, potassium oxide, and flame retardant in step (2) is 100:5 - 10:1 - 5:20:20 - 40.

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