Preparation method of modified fluorosilicone elastomer composite material

Abstract

The invention discloses a preparation method of a modified fluorosilicone elastomer composite material. The preparation method comprises the following steps: S1, weighing raw materials of the modified fluorosilicone elastomer composite material; the modified fluorosilicone elastomer composite material is prepared from the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 20 to 30 parts of reinforcing filler I, 20 to 40 parts of reinforcing filler II, 0.2 to 0.4 part of processing aid, 0.2 to 0.4 part of anti-aging agent and 0.6 to 1.0 part of vulcanizing agent, s2, fluorosilicone raw rubber is put into the internal mixer for internal mixing; s3, preparing rubber to be subjected to open milling; s4, preparing a primary vulcanization material; and S5, preparing the modified fluorosilicone elastomer composite material. According to the preparation method of the modified fluorosilicone elastomer composite material provided by the invention, the dispersity of the reinforcing filler is improved, and the mechanical property of the prepared modified fluorosilicone elastomer composite material can be effectively improved under the action of the reinforcing filler.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone rubber, and in particular relates to a method for preparing a modified fluorosilicone elastomer composite material. Background Art

[0002] Fluorosilicone elastomer composite materials are generally based on fluorosilicone rubber. Fluorosilicone rubber is a new type of rubber that combines the characteristics of silicone rubber and fluororubber and has excellent performance in many aspects. The processing of fluorosilicone rubber mainly includes mixing, heat treatment, open refining and vulcanization.

[0003] During the mixing process, if the ingredients in the raw materials (generally referring to reinforcing fillers) are unevenly dispersed, pigment spots are likely to appear in the finished product, affecting the quality of subsequent molded products; in addition, the overall performance of existing mixed rubbers is poor, which limits its scope of application. Summary of the invention

[0004] The purpose of the present invention is to overcome the above problems existing in the prior art, provide a method for preparing a modified fluorosilicone elastomer composite material, improve the dispersibility of the reinforcing filler, and through the effect of the reinforcing filler, effectively improve the mechanical properties of the prepared modified fluorosilicone elastomer composite material.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] A method for preparing a modified fluorosilicone elastomer composite material, the preparation method comprising the following steps:

[0007] S1: Weigh the raw materials of the modified fluorosilicone elastomer composite material;

[0008] The modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 20-30 parts of reinforcing filler 1, 20-40 parts of reinforcing filler 2, 0.2-0.4 parts of processing aid, 0.2-0.4 parts of antioxidant and 0.6-1.0 parts of vulcanizing agent;

[0009] Wherein, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black in a mass ratio of 1:(3-4);

[0010] The second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black in a mass ratio of (0.1-1):1;

[0011] S2: Add fluorosilicone raw rubber into the internal mixer for internal mixing;

[0012] S3: Before the start of internal mixing, a processing aid and an anti-aging agent are added to the internal mixer to start internal mixing. Within 1-3 minutes after the start of internal mixing, a reinforcing filler 1 is added to the internal mixer. After that, reinforcing filler 2 is added to the internal mixer in batches every 3-5 minutes. After all reinforcing fillers 2 are added, internal mixing is continued for 10-30 minutes to prepare the rubber to be mixed;

[0013] S4: placing the rubber to be mixed in an open mill, adding a vulcanizing agent into the open mill, and performing a first-stage vulcanization to obtain a primary vulcanized material;

[0014] S5: loading the primary vulcanized material into a vulcanization mold, performing two-stage vulcanization, and then cooling to prepare a modified fluorosilicone elastomer composite material.

[0015] Furthermore, in the modified fluorosilicone elastomer composite material, the mass ratio of the reinforcing filler 1 to the reinforcing filler 2 is 1:(1-1.5).

[0016] Furthermore, the preparation process of the modified silica is as follows:

[0017] S11: adding equal amounts of multiple silane coupling agents into anhydrous ethanol respectively, stirring and mixing evenly, to prepare multiple coupling agent ethanol solutions;

[0018] S12: placing silica in a reaction container and placing it in a constant temperature water bath at 60-80° C., spraying various coupling agent ethanol solutions onto the surface of silica powder using an atomizing device during the constant temperature water bath, and continuously stirring the silica powder during the spraying process;

[0019] S13: After spraying, stirring is continued for 10-20 minutes, and then drying is carried out in an oven at 80-120° C. to prepare modified silica.

[0020] Further, the concentration of the coupling agent ethanol solution is 0.01-0.02%;

[0021] The mass ratio of the total mass of the various silane coupling agents to the mass of white carbon black is (0.05-0.10):1;

[0022] There are no less than 2 types of silane coupling agents;

[0023] The silane coupling agent is any one of KH550, KH560, KH570, KH792, and Si69.

[0024] Furthermore, the preparation process of the modified carbon black is as follows:

[0025] S21: extracting carbon black with toluene as solvent, adding the extracted carbon black and an oxidizing agent into a reaction container at a mass volume ratio of 1 g: (10-30) mL after drying, and ultrasonically dispersing for 20-40 min, heating to 90-100° C. under nitrogen for 4-6 h, cooling and filtering to prepare a filter cake, washing the filter cake with ethanol, and drying to prepare oxidized carbon black;

[0026] S22: adding oxidized carbon black, formaldehyde solution and catalyst into a reaction vessel in a mass ratio of 1:(6-10):(0.1-1.0), heating to 40-80°C for reaction for 3 hours and then centrifuging, washing the centrifugal precipitate with water until the discharged waste liquid is neutral, and then drying it in a vacuum oven at 60°C for 20 hours to prepare surface hydroxymethylated carbon black;

[0027] S23: Under a nitrogen environment, the prepared surface hydroxymethylated carbon black and butyl acrylate ethanol solution are placed in a reaction container, ultrasonically dispersed and heated to 30-60° C., and ammonium cerium nitrate solution is added dropwise to react. After reacting for 4-6 hours, the reaction product is precipitated in acetone, filtered, and then vacuum dried at 40-60° C. to prepare modified carbon black;

[0028] The preparation process of the antibacterial carbon black is as follows: the oxidized carbon black prepared in the above step S21 is placed in a reaction container, anhydrous ethanol is added for preliminary mixing, concentrated ammonia water is added dropwise, and ultrasonic dispersion is performed at room temperature for 20-40 minutes. After the ultrasonic dispersion is completed, tetrabutyl titanate is added dropwise, and the reaction is carried out by magnetic stirring at 40-60°C for 6-10 hours. After the reaction is completed, the reaction product is centrifuged, washed, and dried to prepare antibacterial carbon black.

[0029] Further, in step S21, the oxidizing agent is any one of nitric acid solution, hydrogen peroxide, and peracetic acid;

[0030] The concentration of the nitric acid solution is 60-70%;

[0031] In step S22, the concentration of the formaldehyde solution is 26-40%;

[0032] The catalyst is a sodium hydroxide solution with a concentration of 15-30%.

[0033] Further, in step S23, the concentration of the butyl acrylate ethanol solution is 1-3 mol / L;

[0034] The mass ratio of the surface hydroxymethylated carbon black to the butyl acrylate in the butyl acrylate ethanol solution is 1:(20-40);

[0035] The concentration of the cerium ammonium nitrate solution is 15-30mmol / L;

[0036] The mass ratio of the surface hydroxymethylated carbon black to the ammonium cerium nitrate in the ammonium cerium nitrate solution is 1:(0.1-0.2).

[0037] Furthermore, in the preparation process of antibacterial carbon black, the mass ratio of anhydrous ethanol, concentrated ammonia water, tetrabutyl titanate, and oxidized carbon black is (10-20): (0.01-0.10): (0.1-0.5): 0.001.

[0038] Further, in step S1, the processing aid is a mixture of stearic acid and stearamide in a mass ratio of 1:(0.1-0.6);

[0039] The antioxidant is any one or more of an amine antioxidant, a phenolic antioxidant, and a heterocyclic antioxidant mixed in any proportion;

[0040] The vulcanizing agent is a dipentadienyl vulcanizing agent.

[0041] Further, in step S2, the initial temperature in the internal mixer is set to 80-100°C, and the rotation speed is 40-60r / min;

[0042] In step S4, the curing temperature is 160-180°C and the curing time is 10-20 minutes;

[0043] In step S5, the second stage vulcanization temperature is 180-220° C., and the second stage vulcanization time is 1.5-2.5 hours.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention provides a method for preparing a modified fluorosilicone elastomer composite material, which improves the dispersibility of reinforcing fillers and can effectively improve the mechanical properties of the prepared modified fluorosilicone elastomer composite material through the effect of reinforcing fillers.

[0046] 2. In the present invention, the reinforcing fillers are white carbon black and carbon black, which effectively reinforce the prepared modified fluorosilicone elastomer composite material; in the preparation method, by first adding white carbon black and then adding carbon black in batches, the formation of the bonding rubber is assisted and the mechanical properties of the subsequent vulcanized rubber can be improved.

[0047] 3. In the present invention, the mass ratio of reinforcing filler 1 to reinforcing filler 2 in the modified fluorosilicone elastomer composite material is limited. Since there is a large difference in surface energy between silica and carbon black particles, it is difficult to generate a filler network. Therefore, the mass ratio of reinforcing filler 1 to reinforcing filler 2 is limited.

[0048] 4. In the present invention, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black. The modified white carbon black is prepared by modification with a variety of silane coupling agents. The white carbon black is surface treated by the dry modification process to effectively perform organic silanization on the surface of the white carbon black. In the preparation method of the modified fluorosilicone elastomer composite material, the reinforcing filler 1 is first added and mixed with the fluorosilicone raw rubber. Since white carbon black has a strong adsorption capacity for small molecular substances, it can prevent other compounding agents from occupying the surface of the white carbon black and affecting its reaction activity.

[0049] 5. In the present invention, the second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black. The modified carbon black is prepared by surface grafting of surface hydroxylated carbon black, and its dispersion stability during the mixing process is improved. Through the preparation of antibacterial carbon black, carbon black-titanium dioxide composite particles are prepared, and titanium dioxide is introduced, so that the prepared modified fluorosilicone elastomer composite material has certain antibacterial properties, thereby broadening its application field. DETAILED DESCRIPTION

[0050] 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 the embodiments. 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.

[0051] The present invention provides a method for preparing a modified fluorosilicone elastomer composite material, the preparation method comprising the following steps:

[0052] S1: Weigh the raw materials of the modified fluorosilicone elastomer composite material;

[0053] The modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 20-30 parts of reinforcing filler 1, 20-40 parts of reinforcing filler 2, 0.2-0.4 parts of processing aid, 0.2-0.4 parts of antioxidant and 0.6-1.0 parts of vulcanizing agent;

[0054] Wherein, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black in a mass ratio of 1:(3-4);

[0055] The second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black in a mass ratio of (0.1-1):1;

[0056] In the modified fluorosilicone elastomer composite material, the mass ratio of the reinforcing filler 1 to the reinforcing filler 2 is 1:(1-1.5);

[0057] The preparation process of modified silica is as follows:

[0058] S11: adding multiple equal amounts of silane coupling agents to anhydrous ethanol respectively, stirring and mixing evenly, to prepare multiple coupling agent ethanol solutions with a concentration of 0.01-0.02%; specifically, the types of silane coupling agents are not less than 2;

[0059] Wherein, the silane coupling agent is any one of KH550, KH560, KH570, KH792, and Si69;

[0060] S12: placing gas phase silica in a reaction container, and placing it in a constant temperature water bath at 60-80°C. During the constant temperature water bath, using an atomizing device to spray various coupling agent ethanol solutions onto the surface of the silica powder. During the spraying process, the silica powder is continuously stirred; wherein the total mass ratio of the various silane coupling agents to the mass ratio of silica is (0.05-0.10):1;

[0061] S13: After the spraying is completed, the mixture is stirred for 10-20 minutes, and then dried in an oven at 80-120° C. to prepare modified silica;

[0062] The preparation process of modified carbon black is as follows:

[0063] S21: extracting carbon black with toluene as solvent, adding the extracted carbon black and an oxidizing agent into a reaction container at a mass volume ratio of 1 g: (10-30) mL after drying, and ultrasonically dispersing for 20-40 min, heating to 90-100° C. under nitrogen for 4-6 h, cooling and filtering to prepare a filter cake, washing the filter cake with ethanol, and drying to prepare oxidized carbon black;

[0064] In step S21, the oxidizing agent is any one of nitric acid solution, hydrogen peroxide, and peracetic acid; further, the concentration of the nitric acid solution is 60-70%;

[0065] S22: adding oxidized carbon black, a formaldehyde solution with a concentration of 26-40%, and a catalyst (a sodium hydroxide solution with a concentration of 15-30%) into a reaction container in a mass ratio of 1: (6-10): (0.1-1.0), heating to 40-80° C. for reaction for 3 hours, and then centrifuging. The centrifugal precipitate is washed with water until the discharged waste liquid is neutral, and then placed in a vacuum oven at 60° C. for drying for 20 hours to prepare surface hydroxymethylated carbon black;

[0066] S23: Under a nitrogen environment, the prepared surface hydroxymethylated carbon black and a 1-3 mol / L butyl acrylate ethanol solution are placed in a reaction container, ultrasonically dispersed and heated to 30-60° C., and a 15-30 mmol / L cerium ammonium nitrate solution is added dropwise to react. After reacting for 4-6 hours, the reaction product is precipitated in acetone, filtered, and then vacuum dried at 40-60° C. to prepare modified carbon black;

[0067] In this step, the mass ratio of the surface hydroxymethylated carbon black to the butyl acrylate in the butyl acrylate ethanol solution is 1:(20-40);

[0068] The mass ratio of the surface hydroxymethylated carbon black to the ammonium cerium nitrate in the ammonium cerium nitrate solution is 1:(0.1-0.2);

[0069] The preparation process of antibacterial carbon black is as follows: the oxidized carbon black prepared in the above step S21 is placed in a reaction container, anhydrous ethanol is added and initially mixed, and then concentrated ammonia water is added dropwise, and ultrasonic dispersion is performed at room temperature for 20-40 minutes. After the ultrasonic dispersion is completed, tetrabutyl titanate is added dropwise, and magnetic stirring is performed at 40-60° C. for 6-10 hours to react. After the reaction is completed, the reaction product is centrifuged, washed, and dried to prepare antibacterial carbon black;

[0070] In the preparation process of antibacterial carbon black, the mass ratio of anhydrous ethanol, concentrated ammonia water, tetrabutyl titanate, and oxidized carbon black is (10-20): (0.01-0.10): (0.1-0.5): 0.001;

[0071] The processing aid is a mixture of stearic acid and stearamide in a mass ratio of 1:(0.1-0.6);

[0072] The antioxidant is any one or more of an amine antioxidant, a phenolic antioxidant, and a heterocyclic antioxidant mixed in any proportion;

[0073] The vulcanizing agent is a dipentadienyl vulcanizing agent, i.e., 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane;

[0074] S2: Add fluorosilicone raw rubber into the internal mixer for internal mixing. The initial temperature in the internal mixer is set to 80-100°C and the speed is 40-60r / min;

[0075] S3: Before the start of internal mixing, a processing aid and an anti-aging agent are added to the internal mixer to start internal mixing. Within 1-3 minutes after the start of internal mixing, a reinforcing filler 1 is added to the internal mixer. After that, reinforcing filler 2 is added to the internal mixer in batches every 3-5 minutes. After all reinforcing fillers 2 are added, internal mixing is continued for 10-30 minutes to prepare the rubber to be mixed;

[0076] S4: placing the rubber to be mixed in an open mill, adding a vulcanizing agent into the open mill, and performing a first-stage vulcanization to prepare a primary vulcanized material; wherein the first-stage vulcanization temperature is 160-180° C., and the first-stage vulcanization time is 10-20 min;

[0077] S5: loading the primary vulcanized material into a vulcanization mold, performing a second-stage vulcanization, and then cooling to prepare a modified fluorosilicone elastomer composite material; wherein the second-stage vulcanization temperature is 180-220° C., and the second-stage vulcanization time is 1.5-2.5 hours.

[0078] The following are specific examples. Unless otherwise specified, all raw materials in the following examples can be obtained from commercial sources.

[0079] In the following embodiments, the white carbon black is selected from fumed white carbon black;

[0080] Carbon black is selected from virgin carbon black.

[0081] Example 1

[0082] This embodiment provides a preparation process of modified white carbon black, and the preparation process is as follows:

[0083] S11: adding a plurality of silane coupling agents to anhydrous ethanol respectively, stirring and mixing them evenly, and preparing a plurality of coupling agent ethanol solutions with a concentration of 0.015%;

[0084] Among them, the silane coupling agents are KH550, KH570, and KH792;

[0085] S12: placing gas phase silica in a reaction container and placing it in a constant temperature water bath at 70° C., spraying various coupling agent ethanol solutions onto the surface of silica powder using an atomizing device during the constant temperature water bath, and continuously stirring the silica powder during the spraying process; wherein the total mass ratio of the various silane coupling agents to the mass ratio of silica is 0.08:1;

[0086] S13: After the spraying is completed, stirring is continued for 15 minutes, and then drying is carried out in an oven at 100° C. to prepare modified silica.

[0087] Example 2

[0088] This embodiment provides a preparation process of modified white carbon black, and the preparation process is as follows:

[0089] S11: adding a plurality of silane coupling agents to anhydrous ethanol respectively, stirring and mixing them evenly, and preparing a plurality of coupling agent ethanol solutions with a concentration of 0.01%;

[0090] Among them, the silane coupling agents are KH550, KH570, and KH792;

[0091] S12: placing gas phase silica in a reaction container and placing it in a constant temperature water bath at 60° C., spraying various coupling agent ethanol solutions onto the surface of silica powder using an atomizing device during the constant temperature water bath, and continuously stirring the silica powder during the spraying process; wherein the total mass ratio of the various silane coupling agents to the mass ratio of silica is 0.10:1;

[0092] S13: After spraying, stirring was continued for 10 minutes, and then drying was carried out in an oven at 80° C. to prepare modified silica.

[0093] Example 3

[0094] This embodiment provides a preparation process of modified white carbon black, and the preparation process is as follows:

[0095] S11: adding a plurality of silane coupling agents to anhydrous ethanol respectively, stirring and mixing them evenly, and preparing a plurality of coupling agent ethanol solutions with a concentration of 0.02%;

[0096] Among them, the silane coupling agents are KH550, KH570, and KH792;

[0097] S12: placing gas phase silica in a reaction container and placing it in a constant temperature water bath at 80°C, spraying various coupling agent ethanol solutions onto the surface of silica powder using an atomizing device during the constant temperature water bath, and continuously stirring the silica powder during the spraying process; wherein the total mass ratio of the various silane coupling agents to the mass of silica is 0.05:1;

[0098] S13: After spraying, stirring was continued for 20 minutes, and then drying was carried out in an oven at 120° C. to prepare modified silica.

[0099] Example 4

[0100] This embodiment provides a preparation process of modified carbon black and antibacterial carbon black. The preparation process of modified carbon black is as follows:

[0101] S21: extracting carbon black with toluene as solvent, adding the extracted carbon black into a reaction container with hydrogen peroxide in a mass volume ratio of 1g:20mL after drying, and ultrasonically dispersing for 30min, heating to 95°C under nitrogen for 5h, cooling and filtering to prepare a filter cake, washing the filter cake with ethanol, and drying to prepare oxidized carbon black;

[0102] S22: adding oxidized carbon black, a 30% formaldehyde solution, and a 20% sodium hydroxide solution into a reaction container in a mass ratio of 1:8:0.5, heating to 60°C for reaction for 3 hours, and then centrifuging. The centrifugal precipitate is washed with water until the discharged waste liquid is neutral, and then placed in a vacuum oven at 60°C for drying for 20 hours to prepare surface hydroxymethylated carbon black;

[0103] S23: Under a nitrogen environment, the prepared surface hydroxymethylated carbon black and a 2 mol / L butyl acrylate ethanol solution are placed in a reaction container, wherein the mass ratio of the surface hydroxymethylated carbon black to the butyl acrylate in the butyl acrylate ethanol solution is 1:30; ultrasonic dispersion and heating to 40°C, and a 20 mmol / L ammonium cerium nitrate solution is added dropwise for reaction, wherein the mass ratio of the surface hydroxymethylated carbon black to the ammonium cerium nitrate in the ammonium cerium nitrate solution is 1:0.15; after reacting for 5 hours, the reaction product is precipitated in acetone, filtered, and then vacuum dried at 50°C to prepare modified carbon black;

[0104] The preparation process of antibacterial carbon black is as follows: the oxidized carbon black prepared in the above step S21 is placed in a reaction container, anhydrous ethanol is added and initially mixed, and then concentrated ammonia water is added dropwise, and ultrasonic dispersion is performed at room temperature for 30 minutes. After the ultrasonic dispersion is completed, tetrabutyl titanate is added dropwise, and magnetic stirring is performed at 50° C. for 8 hours to react. After the reaction is completed, the reaction product is centrifuged, washed, and dried to prepare antibacterial carbon black;

[0105] Among them, in the preparation process of antibacterial carbon black, the mass ratio of anhydrous ethanol, concentrated ammonia water, tetrabutyl titanate, and oxidized carbon black is 15:0.05:0.3:0.001.

[0106] Example 5

[0107] This embodiment provides a preparation process of modified carbon black and antibacterial carbon black. The preparation process of modified carbon black is as follows:

[0108] S21: extracting carbon black with toluene as solvent, adding the extracted carbon black and hydrogen peroxide into a reaction container at a mass volume ratio of 1g:10mL after drying, and ultrasonically dispersing for 20 minutes. Then, heating to 90°C under nitrogen for 4 hours, cooling and filtering to prepare a filter cake, washing the filter cake with ethanol, and drying to prepare oxidized carbon black;

[0109] S22: adding oxidized carbon black, a 40% formaldehyde solution, and a 30% sodium hydroxide solution into a reaction container at a mass ratio of 1:10:0.1, heating to 80°C for reaction for 3 hours, and then centrifuging. The centrifugal precipitate is washed with water until the discharged waste liquid is neutral, and then placed in a vacuum oven at 60°C for 20 hours to prepare surface hydroxymethylated carbon black;

[0110] S23: Under a nitrogen environment, the prepared surface hydroxymethylated carbon black and a 1 mol / L butyl acrylate ethanol solution are placed in a reaction container, wherein the mass ratio of the surface hydroxymethylated carbon black to the butyl acrylate in the butyl acrylate ethanol solution is 1:20; ultrasonic dispersion and heating to 30°C, and a 15 mmol / L ammonium cerium nitrate solution is added dropwise for reaction, wherein the mass ratio of the surface hydroxymethylated carbon black to the ammonium cerium nitrate in the ammonium cerium nitrate solution is 1:0.1; after reacting for 4 hours, the reaction product is precipitated in acetone, filtered, and then vacuum dried at 40°C to prepare modified carbon black;

[0111] The preparation process of antibacterial carbon black is as follows: the oxidized carbon black prepared in the above step S21 is placed in a reaction container, anhydrous ethanol is added and initially mixed, and then concentrated ammonia water is added dropwise, and ultrasonic dispersion is performed at room temperature for 20 minutes. After the ultrasonic dispersion is completed, tetrabutyl titanate is added dropwise, and magnetic stirring is performed at 40° C. for 6 hours to react. After the reaction is completed, the reaction product is centrifuged, washed, and dried to prepare antibacterial carbon black;

[0112] Among them, in the preparation process of antibacterial carbon black, the mass ratio of anhydrous ethanol, concentrated ammonia water, tetrabutyl titanate, and oxidized carbon black is 20:0.01:0.1:0.001.

[0113] Example 6

[0114] This embodiment provides a preparation process of modified carbon black and antibacterial carbon black. The preparation process of modified carbon black is as follows:

[0115] S21: extracting carbon black with toluene as solvent, adding the extracted carbon black into a reaction container with hydrogen peroxide in a mass volume ratio of 1g:30mL after drying, and ultrasonically dispersing for 40min, heating to 100°C under nitrogen for reaction for 6h, cooling and filtering to prepare a filter cake, washing the filter cake with ethanol, and drying to prepare oxidized carbon black;

[0116] S22: adding oxidized carbon black, a 26% formaldehyde solution, and a 15% sodium hydroxide solution into a reaction container in a mass ratio of 1:6:1.0, heating to 40°C for reaction for 3 hours, and then centrifuging. The centrifugal precipitate is washed with water until the discharged waste liquid is neutral, and then placed in a vacuum oven at 60°C for 20 hours to prepare surface hydroxymethylated carbon black;

[0117] S23: Under a nitrogen environment, the prepared surface hydroxymethylated carbon black and a 3 mol / L butyl acrylate ethanol solution are placed in a reaction container, wherein the mass ratio of the surface hydroxymethylated carbon black to the butyl acrylate in the butyl acrylate ethanol solution is 1:40; ultrasonic dispersion and heating to 60°C, and a 30 mmol / L ammonium cerium nitrate solution is added dropwise for reaction, wherein the mass ratio of the surface hydroxymethylated carbon black to the ammonium cerium nitrate in the ammonium cerium nitrate solution is 1:0.2; after reacting for 6 hours, the reaction product is precipitated in acetone, filtered, and then vacuum dried at 60°C to prepare modified carbon black;

[0118] The preparation process of antibacterial carbon black is as follows: the oxidized carbon black prepared in the above step S21 is placed in a reaction container, anhydrous ethanol is added and initially mixed, and then concentrated ammonia water is added dropwise, and ultrasonic dispersion is performed at room temperature for 40 minutes. After the ultrasonic dispersion is completed, tetrabutyl titanate is added dropwise, and magnetic stirring is performed at 60° C. for 10 hours to react. After the reaction is completed, the reaction product is centrifuged, washed, and dried to prepare antibacterial carbon black;

[0119] Among them, in the preparation process of antibacterial carbon black, the mass ratio of anhydrous ethanol, concentrated ammonia water, tetrabutyl titanate, and oxidized carbon black is 10:0.10:0.5:0.001.

[0120] Example 7

[0121] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, the preparation method comprising the following steps:

[0122] S1: Weigh the raw materials of the modified fluorosilicone elastomer composite material;

[0123] The modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 25 parts of reinforcing filler 1, 30 parts of reinforcing filler 2, 0.3 parts of processing aid, 0.3 parts of antioxidant and 0.7 parts of vulcanizing agent;

[0124] Among them, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black in a mass ratio of 1:3.6;

[0125] In this embodiment, the modified silica is prepared according to the preparation process of the modified silica provided in Example 1;

[0126] The second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black in a mass ratio of 0.5:1;

[0127] In this embodiment, the modified carbon black and the antibacterial carbon black are prepared according to the preparation process of the modified carbon black and the antibacterial carbon black provided in Example 4;

[0128] In the modified fluorosilicone elastomer composite material, the mass ratio of the reinforcing filler 1 to the reinforcing filler 2 is 1:1.2;

[0129] The processing aid is a mixture of stearic acid and stearamide in a mass ratio of 1:0.3;

[0130] The antioxidant is 2,4-dimethyl-6-tert-butylphenol;

[0131] The vulcanizing agent is a dipentadienyl vulcanizing agent, i.e., 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane;

[0132] S2: Add fluorosilicone rubber into the internal mixer for internal mixing. The initial temperature in the internal mixer is set to 85°C and the speed is 55r / min.

[0133] S3: Before the start of internal mixing, add processing aids and anti-aging agents into the internal mixer, start internal mixing, add reinforcing filler 1 into the internal mixer within 2 minutes after the start of internal mixing, and then add reinforcing filler 2 into the internal mixer in three batches every 4 minutes. After all reinforcing filler 2 is added, continue internal mixing for 20 minutes to prepare the rubber to be mixed;

[0134] S4: placing the rubber to be mixed in an open mill, adding a vulcanizing agent into the open mill, and performing a first-stage vulcanization to prepare an initial vulcanized material; wherein the first-stage vulcanization temperature is 170° C., and the first-stage vulcanization time is 15 min;

[0135] S5: loading the primary vulcanized material into a vulcanization mold, performing a second-stage vulcanization, and then cooling to prepare a modified fluorosilicone elastomer composite material; wherein the second-stage vulcanization temperature is 200° C., and the second-stage vulcanization time is 2 hours.

[0136] Example 8

[0137] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, which is different from Example 7 in that, in this embodiment, modified silica is prepared according to the preparation process of modified silica provided in Example 2, and modified carbon black and antibacterial carbon black are prepared according to the preparation process of modified carbon black and antibacterial carbon black provided in Example 5, and the remaining operating steps are the same as those in Example 7.

[0138] Example 9

[0139] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, which is different from Example 7 in that, in this embodiment, modified silica is prepared according to the preparation process of modified silica provided in Example 3, and modified carbon black and antibacterial carbon black are prepared according to the preparation process of modified carbon black and antibacterial carbon black provided in Example 6, and the remaining operating steps are the same as Example 7.

[0140] Example 10

[0141] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, the preparation method comprising the following steps:

[0142] S1: Weigh the raw materials of the modified fluorosilicone elastomer composite material;

[0143] The modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 20 parts of reinforcing filler 1, 20 parts of reinforcing filler 2, 0.4 parts of processing aid, 0.2 parts of antioxidant and 0.6 parts of vulcanizing agent;

[0144] Among them, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black in a mass ratio of 1:3;

[0145] In this embodiment, the modified silica is prepared according to the preparation process of the modified silica provided in Example 1;

[0146] The second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black in a mass ratio of 0.1:1;

[0147] In this embodiment, the modified carbon black and the antibacterial carbon black are prepared according to the preparation process of the modified carbon black and the antibacterial carbon black provided in Example 4;

[0148] In the modified fluorosilicone elastomer composite material, the mass ratio of the reinforcing filler 1 to the reinforcing filler 2 is 1:1;

[0149] The processing aid is a mixture of stearic acid and stearamide in a mass ratio of 1:0.1;

[0150] The antioxidant is 2,4-dimethyl-6-tert-butylphenol;

[0151] The vulcanizing agent is a dipentadienyl vulcanizing agent, i.e., 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane;

[0152] S2: Add fluorosilicone rubber into the internal mixer for internal mixing. The initial temperature in the internal mixer is set to 80°C and the speed is 40r / min.

[0153] S3: Before the start of internal mixing, add processing aids and anti-aging agents into the internal mixer, start internal mixing, add reinforcing filler 1 into the internal mixer within 1 minute after the start of internal mixing, and then add reinforcing filler 2 into the internal mixer in three batches every 3 minutes. After all reinforcing filler 2 is added, continue internal mixing for 10 minutes to prepare the rubber to be mixed;

[0154] S4: placing the rubber to be mixed in an open mill, adding a vulcanizing agent into the open mill, and performing a first-stage vulcanization to prepare an initial vulcanized material; wherein the first-stage vulcanization temperature is 160° C., and the first-stage vulcanization time is 10 min;

[0155] S5: loading the primary vulcanized material into a vulcanization mold, performing a second-stage vulcanization, and then cooling to prepare a modified fluorosilicone elastomer composite material; wherein the second-stage vulcanization temperature is 180° C., and the second-stage vulcanization time is 1.5 h.

[0156] Embodiment 11

[0157] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, which is different from Example 10 in that, in this embodiment, modified silica is prepared according to the preparation process of modified silica provided in Example 2, and modified carbon black and antibacterial carbon black are prepared according to the preparation process of modified carbon black and antibacterial carbon black provided in Example 5, and the remaining operating steps are the same as Example 10.

[0158] Example 12

[0159] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, which is different from Example 10 in that, in this embodiment, modified silica is prepared according to the preparation process of modified silica provided in Example 3, and modified carbon black and antibacterial carbon black are prepared according to the preparation process of modified carbon black and antibacterial carbon black provided in Example 6, and the remaining operating steps are the same as Example 10.

[0160] Example 13

[0161] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, the preparation method comprising the following steps:

[0162] S1: Weigh the raw materials of the modified fluorosilicone elastomer composite material;

[0163] The modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 30 parts of reinforcing filler 1, 40 parts of reinforcing filler 2, 0.2 parts of processing aid, 0.4 parts of antioxidant and 1.0 parts of vulcanizing agent;

[0164] Among them, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black in a mass ratio of 1:4;

[0165] In this embodiment, the modified silica is prepared according to the preparation process of the modified silica provided in Example 1;

[0166] The second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black in a mass ratio of 1:1;

[0167] In this embodiment, the modified carbon black and the antibacterial carbon black are prepared according to the preparation process of the modified carbon black and the antibacterial carbon black provided in Example 4;

[0168] In the modified fluorosilicone elastomer composite material, the mass ratio of the reinforcing filler 1 to the reinforcing filler 2 is 1:1.5;

[0169] The processing aid is a mixture of stearic acid and stearamide in a mass ratio of 1:0.6;

[0170] The antioxidant is 2,4-dimethyl-6-tert-butylphenol;

[0171] The vulcanizing agent is a dipentadienyl vulcanizing agent, i.e., 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane;

[0172] S2: Add fluorosilicone raw rubber into the internal mixer for internal mixing. The initial temperature in the internal mixer is set to 100°C and the speed is 60r / min.

[0173] S3: Before the start of internal mixing, add processing aids and anti-aging agents into the internal mixer, start internal mixing, add reinforcing filler 1 into the internal mixer within 3 minutes after the start of internal mixing, and then add reinforcing filler 2 into the internal mixer in three batches every 5 minutes. After all reinforcing filler 2 is added, continue internal mixing for 30 minutes to prepare the rubber to be mixed;

[0174] S4: placing the rubber to be mixed in an open mill, adding a vulcanizing agent into the open mill, and performing a first-stage vulcanization to prepare an initial vulcanized material; wherein the first-stage vulcanization temperature is 180° C., and the first-stage vulcanization time is 20 min;

[0175] S5: loading the primary vulcanized material into a vulcanization mold, performing a second-stage vulcanization, and then cooling to prepare a modified fluorosilicone elastomer composite material; wherein the second-stage vulcanization temperature is 220° C., and the second-stage vulcanization time is 2.5 h.

[0176] Embodiment 14

[0177] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, which is different from Example 13 in that, in this embodiment, modified silica is prepared according to the preparation process of modified silica provided in Example 2, and modified carbon black and antibacterial carbon black are prepared according to the preparation process of modified carbon black and antibacterial carbon black provided in Example 5, and the remaining operating steps are the same as Example 13.

[0178] Embodiment 15

[0179] This embodiment provides a method for preparing a modified fluorosilicone elastomer composite material, which is different from Example 13 in that, in this embodiment, modified silica is prepared according to the preparation process of modified silica provided in Example 3, and modified carbon black and antibacterial carbon black are prepared according to the preparation process of modified carbon black and antibacterial carbon black provided in Example 6, and the remaining operating steps are the same as Example 13.

[0180] Comparative Example 1

[0181] This comparative example provides a method for preparing a modified fluorosilicone elastomer composite material. In this comparative example, compared with Example 7, the modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 55 parts of reinforcing filler, 0.3 parts of processing aid, 0.3 parts of antioxidant and 0.7 parts of vulcanizing agent; the remaining operating steps are the same as Example 7.

[0182] Comparative Example 2

[0183] This comparative example provides a method for preparing a modified fluorosilicone elastomer composite material. In this comparative example, compared with Example 7, the modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 55 parts of reinforcing filler, 0.3 parts of processing aid, 0.3 parts of antioxidant and 0.7 parts of vulcanizing agent; the remaining operating steps are the same as Example 7.

[0184] Comparative Example 3

[0185] This comparative example provides a method for preparing a modified fluorosilicone elastomer composite material. In this comparative example, compared with Example 7, the modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 55 parts of white carbon black, 0.3 parts of processing aid, 0.3 parts of antioxidant and 0.7 parts of vulcanizing agent; the remaining operating steps are the same as Example 7.

[0186] Comparative Example 4

[0187] This comparative example provides a method for preparing a modified fluorosilicone elastomer composite material. In this comparative example, compared with Example 7, the modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 55 parts of carbon black, 0.3 parts of processing aid, 0.3 parts of antioxidant and 0.7 parts of vulcanizing agent; the remaining operating steps are the same as Example 7.

[0188] Comparative Example 5

[0189] This comparative example provides a method for preparing a modified fluorosilicone elastomer composite material. In this comparative example, compared with Example 7, step S3 is replaced by: before the start of internal mixing, a processing aid and an anti-aging agent are added into the internal mixer to start internal mixing; within 2 minutes after the start of internal mixing, reinforcing filler 1 and reinforcing filler 2 are added into the internal mixer; after all the additions are completed, internal mixing is continued for 20 minutes to prepare the rubber to be mixed; the remaining operating steps are the same as those in Example 7.

[0190] Comparative Example 6

[0191] This comparative example provides a method for preparing a modified fluorosilicone elastomer composite material. In this comparative example, compared with Example 7, step S3 is replaced by: before the start of internal mixing, a processing aid and an anti-aging agent are added into the internal mixer to start internal mixing; within 2 minutes after the start of internal mixing, reinforcing filler 2 is added into the internal mixer; thereafter, reinforcing filler 1 is added into the internal mixer in three batches every 4 minutes; after all reinforcing filler 1 is added, internal mixing is continued for 20 minutes to prepare the rubber to be mixed.

[0192] Experimental example

[0193] The mechanical properties of the modified fluorosilicone elastomer composite materials prepared in Examples 7-15 and Comparative Examples 1-6 were tested. The specific test results are shown in Table 1.

[0194] The change rate of heat aging tensile strength and the change rate of heat aging elongation at break are obtained by placing the prepared modified fluorosilicone elastomer composite material at 240°C for 72 hours and testing its tensile strength before and after the test. The specific calculation formula is as follows:

[0195]

[0196] Table 1

[0197]

[0198] It can be seen from the data in Table 1 that in the present invention, the modified fluorosilicone elastomer composite materials prepared in Examples 7-15 have better comprehensive performance than the modified fluorosilicone elastomer composite materials prepared in Comparative Examples 1-6; indicating that the preparation method and the formula of the modified fluorosilicone elastomer composite material provided by the present invention, the prepared modified fluorosilicone elastomer composite material, have better comprehensive performance.

[0199] The present invention provides a method for preparing a modified fluorosilicone elastomer composite material, which improves the dispersibility of a reinforcing filler and can effectively improve the mechanical properties of the prepared modified fluorosilicone elastomer composite material through the effect of the reinforcing filler.

[0200] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0201] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing a modified fluorosilicone elastomer composite material, characterized in that: The preparation method comprises the following steps: S1: Weigh the raw materials of the modified fluorosilicone elastomer composite material; The modified fluorosilicone elastomer composite material includes the following raw materials in parts by weight: 100 parts of fluorosilicone raw rubber, 20-30 parts of reinforcing filler 1, 20-40 parts of reinforcing filler 2, 0.2-0.4 parts of processing aid, 0.2-0.4 parts of antioxidant and 0.6-1.0 parts of vulcanizing agent; Wherein, the reinforcing filler 1 is a mixture of white carbon black and modified white carbon black in a mass ratio of 1:(3-4); The second reinforcing filler is a mixture of modified carbon black and antibacterial carbon black in a mass ratio of (0.1-1):1; S2: Add fluorosilicone raw rubber into the internal mixer for internal mixing; S3: Before the start of internal mixing, a processing aid and an anti-aging agent are added to the internal mixer to start internal mixing. Within 1-3 minutes after the start of internal mixing, a reinforcing filler 1 is added to the internal mixer. After that, reinforcing filler 2 is added to the internal mixer in batches every 3-5 minutes. After all reinforcing fillers 2 are added, internal mixing is continued for 10-30 minutes to prepare the rubber to be mixed; S4: placing the rubber to be mixed in an open mill, adding a vulcanizing agent into the open mill, and performing a first-stage vulcanization to obtain a primary vulcanized material; S5: loading the primary vulcanized material into a vulcanization mold, performing two-stage vulcanization, and then cooling to prepare a modified fluorosilicone elastomer composite material.

2. The method for preparing a modified fluorosilicone elastomer composite material according to claim 1, characterized in that: In the modified fluorosilicone elastomer composite material, the mass ratio of the first reinforcing filler to the second reinforcing filler is 1:(1-1.5).

3. The method for preparing a modified fluorosilicone elastomer composite material according to claim 1, characterized in that: The preparation process of the modified silica is as follows: S11: adding equal amounts of multiple silane coupling agents into anhydrous ethanol respectively, stirring and mixing evenly, to prepare multiple coupling agent ethanol solutions; S12: placing silica in a reaction container and placing it in a constant temperature water bath at 60-80° C., spraying various coupling agent ethanol solutions onto the surface of silica powder using an atomizing device during the constant temperature water bath, and continuously stirring the silica powder during the spraying process; S13: After spraying, stirring is continued for 10-20 minutes, and then drying is carried out in an oven at 80-120° C. to prepare modified silica.

4. The method for preparing a modified fluorosilicone elastomer composite material according to claim 3, characterized in that: The concentration of the coupling agent ethanol solution is 0.01-0.02%; The mass ratio of the total mass of the various silane coupling agents to the mass of white carbon black is (0.05-0.10):1; There are no less than 2 types of silane coupling agents; The silane coupling agent is any one of KH550, KH560, KH570, KH792, and Si69.

5. The method for preparing a modified fluorosilicone elastomer composite material according to claim 1, characterized in that: The preparation process of the modified carbon black is as follows: S21: extracting carbon black with toluene as solvent, adding the extracted carbon black and an oxidizing agent into a reaction container at a mass volume ratio of 1 g: (10-30) mL after drying, and ultrasonically dispersing for 20-40 min, heating to 90-100° C. under nitrogen for 4-6 h, cooling and filtering to prepare a filter cake, washing the filter cake with ethanol, and drying to prepare oxidized carbon black; S22: adding oxidized carbon black, formaldehyde solution and catalyst into a reaction vessel in a mass ratio of 1:(6-10):(0.1-1.0), heating to 40-80°C for reaction for 3 hours and then centrifuging, washing the centrifugal precipitate with water until the discharged waste liquid is neutral, and then drying it in a vacuum oven at 60°C for 20 hours to prepare surface hydroxymethylated carbon black; S23: Under a nitrogen environment, the prepared surface hydroxymethylated carbon black and butyl acrylate ethanol solution are placed in a reaction container, ultrasonically dispersed and heated to 30-60° C., and ammonium cerium nitrate solution is added dropwise to react. After reacting for 4-6 hours, the reaction product is precipitated in acetone, filtered, and then vacuum dried at 40-60° C. to prepare modified carbon black; The preparation process of the antibacterial carbon black is as follows: the oxidized carbon black prepared in the above step S21 is placed in a reaction container, anhydrous ethanol is added for preliminary mixing, concentrated ammonia water is added dropwise, and ultrasonic dispersion is performed at room temperature for 20-40 minutes. After the ultrasonic dispersion is completed, tetrabutyl titanate is added dropwise, and the reaction is carried out by magnetic stirring at 40-60°C for 6-10 hours. After the reaction is completed, the reaction product is centrifuged, washed, and dried to prepare antibacterial carbon black.

6. The method for preparing a modified fluorosilicone elastomer composite material according to claim 5, characterized in that: In step S21, the oxidizing agent is any one of nitric acid solution, hydrogen peroxide, and peracetic acid; The concentration of the nitric acid solution is 60-70%; In step S22, the concentration of the formaldehyde solution is 26-40%; The catalyst is a sodium hydroxide solution with a concentration of 15-30%.

7. The method for preparing a modified fluorosilicone elastomer composite material according to claim 5, characterized in that: In step S23, the concentration of the butyl acrylate ethanol solution is 1-3 mol / L; The mass ratio of the surface hydroxymethylated carbon black to the butyl acrylate in the butyl acrylate ethanol solution is 1:(20-40); The concentration of the cerium ammonium nitrate solution is 15-30mmol / L; The mass ratio of the surface hydroxymethylated carbon black to the ammonium cerium nitrate in the ammonium cerium nitrate solution is 1:(0.1-0.2).

8. The method for preparing a modified fluorosilicone elastomer composite material according to claim 5, characterized in that: In the preparation process of antibacterial carbon black, the mass ratio of anhydrous ethanol, concentrated ammonia water, tetrabutyl titanate and oxidized carbon black is (10-20): (0.01-0.10): (0.1-0.5): 0.

001.

9. The method for preparing a modified fluorosilicone elastomer composite material according to claim 1, characterized in that: In step S1, the processing aid is a mixture of stearic acid and stearamide in a mass ratio of 1:(0.1-0.6); The antioxidant is any one or more of an amine antioxidant, a phenolic antioxidant, and a heterocyclic antioxidant mixed in any proportion; The vulcanizing agent is a dipentadienyl vulcanizing agent.

10. The method for preparing a modified fluorosilicone elastomer composite material according to claim 1, characterized in that: In step S2, the initial temperature in the internal mixer is set to 80-100°C and the rotation speed is 40-60r / min; In step S4, the curing temperature is 160-180°C and the curing time is 10-20 minutes; In step S5, the second stage vulcanization temperature is 180-220° C., and the second stage vulcanization time is 1.5-2.5 hours.

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