Fluorosilicone rubber, fluorosilicone rubber hose, and preparation method and application thereof

Abstract

The present invention discloses a fluorosilicone rubber, a fluorosilicone rubber hose and a preparation method and application thereof. The fluorosilicone rubber is prepared from the following components calculated by weight: 50 to 70 parts of fluorosilicone raw rubber; 20 to 45 parts of high temperature flame retardant silicone rubber; 30 to 40 parts of fumed silica; 0.5 to 2 parts of diisopropylbenzene peroxide; 5 to 10 parts of hydroxy silicone oil; 1 to 3 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane. The fluorosilicone rubber hose of the present invention has good elasticity and flexibility, convenient installation and layout, convenient maintenance, good vibration-proof effect and high reliability. The bonding strength between the hose and the silicone is good, the fatigue resistance of the hose is excellent, the raw materials of the product are easy to obtain, the cost is low, and it is conducive to large-scale production and improving market competitiveness. The combination of fluorosilicone rubber and high temperature resistant silicone saves the cost of raw materials, and can also achieve the characteristics of high temperature resistance, weather resistance, aging resistance and flame retardancy, and at the same time has a breakthrough development in technology.

Description

Technical Field

[0001] The invention relates to a fluorosilicone rubber, a fluorosilicone rubber hose and a preparation method and application thereof, belonging to the technical field of rubber. Background Art

[0002] The automobile industry is a pillar industry of the national economy. The rapid development of the automobile industry in recent years has brought unprecedented opportunities to the rubber industry. While continuously improving product quality and optimizing production processes, the rubber industry pays more attention to the modification of existing synthetic rubber, so that it can continue to develop in the direction of specialization and high performance. At present, the air intake intercooling system of automobile engines with turbochargers is generally composed of components such as air filters, turbochargers, intercoolers and their connecting pipes. The gas pipeline must be connected with a rubber tube and a steel pipe or a blow-molded pipe (that is, the hard pipe must be connected through a hose). Rubber has good flexibility, which can facilitate pipeline layout and assembly, and improve the ability of the gas pipeline system to buffer vibration. For engines with high boost ratios, the temperature of fresh air can reach more than 200°C after passing through the air filter and turbocharger. The hot gas enters the engine after being cooled by the intercooler, thereby increasing the density of the fresh air, allowing the engine to inhale more air and inject more fuel, thereby achieving the purpose of reducing fuel consumption and emissions and increasing engine power. However, this type of connecting rubber hose will age and deform after being used at high temperatures and for a long time, causing the hose and the steel pipe to loosen and the hose to fall off, affecting the driving of the car.

[0003] At present, there are two main types of hoses used in turbocharger system connection lines. One is a hose with acrylic rubber as the main material, which has good oil resistance, but poor high temperature resistance, and the maximum operating temperature is 170°C; the other is a silicone hose, which is a hose with silicone rubber as the main material. Silicone rubber has excellent high temperature resistance, but its oil and gas resistance in the turbocharger system is poor. As time goes by, silicone rubber swells, resulting in a decrease in air tightness. At present, in order to solve the oil and gas resistance problem under high temperature working conditions, the structure commonly used is a structure in which fluororubber is used as the inner rubber and silicone rubber is used as the outer rubber. However, due to the poor bonding performance of fluororubber and unstable bonding with silicone rubber, there will be a greater risk of delamination. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a fluorosilicone rubber, a preparation method of the fluorosilicone rubber, a fluorosilicone rubber hose prepared using the fluorosilicone rubber and a preparation method thereof, and an application of the fluorosilicone rubber hose. The fluorosilicone rubber has excellent oil and gas resistance, high temperature resistance, weather resistance, aging resistance and flame retardant properties. The obtained hose has good flexibility and elasticity, good bonding strength with silicone rubber, and is not easy to fall off.

[0005] In order to solve the above technical problems, the present invention first discloses a fluorosilicone rubber, which is prepared from the following components calculated by weight:

[0006] Fluorosilicone rubber: 50-70 parts;

[0007] High temperature resistant flame retardant silicone rubber: 20-45 parts;

[0008] Fumed silica: 30-40 parts;

[0009] Dicumyl peroxide: 0.5-2 parts;

[0010] Hydroxy silicone oil: 5-10 parts;

[0011] 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane: 1 to 3 parts.

[0012] The preparation of the fluorosilicone rubber described in the present invention refers to the fluoropolysiloxane (fluorosilicone raw rubber) prepared by Wang Chuanping, Yantai University, 2017, master's thesis "Research on Fluorinated Polysiloxane and Functional Silicone Compounds";

[0013] For the preparation of the high temperature resistant flame retardant silicone rubber described in the present invention, please refer to "A modified flame retardant, a high temperature resistant flame retardant silicone rubber using the flame retardant and its application" (CN 111205652 A, May 20, 2020).

[0014] The present invention also discloses a method for preparing the fluorosilicone rubber as described above, the method comprising:

[0015] (1) Mixing: The temperature of the kneader is set to 50°C to 60°C, and fluorosilicone rubber, high temperature flame retardant silicone rubber, fumed silica, dicumyl peroxide and hydroxy silicone oil are weighed according to the proportion and added into the kneader for uniform mixing to obtain a rubber material;

[0016] (2) Plasticizing: The rubber material obtained by mixing in step (1) is placed on a two-roll open mill, plasticized until the rolls are completely wrapped, and the mixed rubber is prepared and left to stand for more than 10 hours. The roll temperature of the two-roll open mill is set at 40°C to 50°C;

[0017] (3) Vulcanization: The mixed rubber after the parking in step (2) is re-mixed on a two-roll mill to the wrapping roll, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is added, and after being mixed evenly on the two-roll mill, the mixed rubber sheet is rolled to form a fluorosilicone rubber. The roller temperature of the two-roll mill is set at 40°C to 50°C. After the fluorosilicone rubber sheet is sampled and placed in a mold, it is vulcanized on a flat vulcanizer at a temperature of 150 to 200°C, cooled to obtain a hot-vulcanized sheet, and the qualified one is used for the next step.

[0018] The present invention also discloses a fluorosilicone rubber hose using the fluorosilicone rubber as described above or using the fluorosilicone rubber prepared by the method as described above, the fluorosilicone rubber hose comprising a fluorosilicone rubber inner tube, the fluorosilicone inner tube is coated with at least one layer of high temperature resistant silicone reinforcement layer, and the high temperature resistant silicone reinforcement layer is coated with a fluorosilicone rubber outer layer.

[0019] Furthermore, the overlap width of the fluorosilicone rubber inner tube and the fluorosilicone rubber outer layer is 10 mm ± 1 mm.

[0020] The present invention also discloses a method for preparing the fluorosilicone rubber hose as described above.

[0021] (1) Calendering: According to the process requirements, a three-roll calender is used to press the fluorosilicone rubber into fluorosilicone sheets and the high-temperature resistant silicone rubber into silicone tape. The high-temperature resistant silicone can be prepared by yourself or purchased from the market.

[0022] (2) Cutting: Cut the pressed fluorosilicone sheet and silicone tape into sizes according to the process requirements; the process requirements of step (1) and step (2) refer to the specific usage requirements, and different usage requirements will result in different thicknesses, sizes, etc.;

[0023] (3) Tube blank molding: Fix the molding die on the molding machine, cover the fluorosilicone sheet on the molding die, adjust the overlap width, and form a fluorosilicone rubber inner tube; wrap a certain number of layers of silicone tape around the fluorosilicone rubber inner tube to form a high-temperature resistant silicone reinforcement layer; cover the high-temperature resistant silicone reinforcement layer with a fluorosilicone rubber outer layer, adjust the overlap width, and form a molded tube blank; the number of layers of silicone tape is determined based on factors such as the pressure required to be withstood in the use environment.

[0024] (4) Shaping: The formed tube blank is put on the shaping mold, wrapped with cellophane, and put into the oven for vulcanization at 150-200°C for 40-50 minutes to obtain a semi-finished product;

[0025] (5) Demolding: Remove the cellophane and the shaping mold from the vulcanized semi-finished product to form a vulcanized fluorosilicone rubber hose;

[0026] (6) Secondary vulcanization: The fluorosilicone rubber hose obtained in step (5) is placed in an oven at 150-180° C. for vulcanization for 3-5 hours to obtain a finished fluorosilicone rubber hose.

[0027] The present invention also discloses a fluorosilicone rubber hose as described above or a fluorosilicone rubber hose prepared according to the method as described above, which is used as a connecting hose in a connecting pipeline of a turbocharger system.

[0028] Therefore, in order to solve the above technical problems, our company has developed a new high-temperature resistant fluorosilicone material by improving the rubber formula, and applied it to the production of fluorosilicone tubes in turbocharger systems.

[0029] At present, there is no report on the application of the modified fluorosilicone rubber in the production of connecting pipes of automotive turbocharger systems.

[0030] The technical properties of the fluorosilicone rubber product obtained by the present invention are as follows:

[0031] 1. Applicable temperature: -50℃~300℃;

[0032] 2. Hardness: 70±5A, breaking strength: ≥8MPa, breaking elongation: ≥200%;

[0033] 3. Hot air aging (300℃×70h): Hardness change (Sh): 0~10; Tensile strength reduction rate: ≥-30%; Elongation at break reduction rate: ≥-50%.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1) The fluorosilicone rubber hose of the present invention has good elasticity and flexibility, is easy to install and arrange when used in the automotive industry, is easy to maintain, has good anti-vibration effect, and has high reliability.

[0036] 2) Due to the use of fluorosilicone rubber and silicone blend modification, the bonding strength between the outer layer, inner tube layer and reinforcement layer is good, the fatigue resistance of the tube body is excellent, and the raw materials of the product are easy to obtain and the cost is low (the cost is reduced by about 40%), which is conducive to large-scale production and improving market competitiveness.

[0037] 3) The combination of fluorosilicone rubber and high temperature resistant silicone saves raw material costs and can also achieve the characteristics of high temperature resistance, weather resistance, aging resistance and flame retardancy, while also achieving breakthrough development in technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the cross-sectional structure of the fluorosilicone rubber hose of Example 4 of the present invention.

[0039] Numbers in the figure: 1-fluorosilicone rubber inner layer; 2-high temperature resistant silicone reinforcement layer; 3-fluorosilicone rubber outer layer. DETAILED DESCRIPTION

[0040] The present invention is further explained below in conjunction with the examples. The following examples are only used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0041] 1. Preparation of fluorosilicone rubber

[0042] Example 1

[0043] (1) Mixing: Set the kneader temperature to 55°C, weigh 50 kg of fluorosilicone raw rubber, 45 kg of high temperature resistant flame retardant silicone rubber, 35 kg of fumed silica, 1 kg of diisopropylbenzene peroxide, and 7 kg of hydroxy silicone oil, add them into the kneader and mix them evenly to obtain a rubber compound.

[0044] (2) Plasticizing: The rubber obtained by mixing in step (1) is placed on a two-roll open mill and plasticized until the rolls are completely wrapped. The mixed rubber is prepared and left to stand for more than 10 hours. The roll temperature of the two-roll open mill is set at 45°C.

[0045] (3) Sulfurization: The mixed rubber after the parking in step (2) was re-mixed on a two-roll mill to the wrapping roll, 3 kg of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane was added, and the mixed rubber sheet was made by the two-roll mill rolls, namely, fluorosilicone rubber, and the roll temperature of the two-roll mill was set at 50° C. The fluorosilicone rubber sheet was qualified after sampling and testing.

[0046] Example 2

[0047] (1) Mixing: The kneading machine temperature is set to 50° C. 70 kg of fluorosilicone rubber, 20 kg of high temperature flame retardant silicone rubber, 30 kg of fumed silica, 1 kg of diisopropylbenzene peroxide, and 5 kg of hydroxy silicone oil are weighed and added into the kneading machine and mixed evenly to obtain a rubber material;

[0048] (2) Plasticizing: The rubber obtained by mixing in step (1) is placed on a two-roll open mill and plasticized until the rolls are completely wrapped. The mixed rubber is prepared and left to stand for more than 10 hours. The roll temperature of the two-roll open mill is set at 45°C.

[0049] (3) Sulfurization: The mixed rubber after the parking in step (2) is re-mixed on a two-roll mill to the wrapping roll, 1 kg of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is added, and the mixed rubber sheet is formed by the two-roll mill rolls, namely, the fluorosilicone rubber, and the roll temperature of the two-roll mill is set to 50° C. The fluorosilicone rubber sheet is qualified after sampling and testing.

[0050] Example 3

[0051] (1) Mixing: The kneading machine temperature is set to 60° C. 60 kg of fluorosilicone rubber, 35 kg of high temperature flame retardant silicone rubber, 35 kg of fumed silica, 1.5 kg of dicumyl peroxide, and 10 kg of hydroxy silicone oil are weighed and added into the kneading machine and mixed evenly to obtain a rubber material;

[0052] (2) Plasticizing: The rubber obtained by mixing in step (1) is placed on a two-roll open mill and plasticized until the rolls are completely wrapped. The mixed rubber is prepared and left to stand for more than 10 hours. The roll temperature of the two-roll open mill is set at 45°C.

[0053] (3) Sulfurization: The mixed rubber after the storage in step (2) is re-mixed on a two-roll mill to the wrapping roll, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is added, and the mixed rubber sheet is made by the two-roll mill rolls, namely, the fluorosilicone rubber, and the roll temperature of the two-roll mill is set to 50° C. The fluorosilicone rubber sheet is qualified after sampling and testing.

[0054] The high temperature resistant flame retardant silicone rubber used in Examples 1-3 of the present invention adopts the film obtained in Example 10 of "A modified flame retardant, a high temperature resistant flame retardant silicone rubber using the flame retardant and its application" (CN 111205652 A, May 20, 2020). The synthesis of fluorosilicone raw rubber is obtained by the method described in 2.3 of Yantai University, Wang Chuanping, 2017, master's thesis "Research on fluorinated polysiloxanes and functional organosilicon compounds".

[0055] 2. Preparation of fluorosilicone rubber hose

[0056] Example 4

[0057] Prepare the connecting hose between turbocharger and intercooler:

[0058] (1) Calendering: Use a three-roll calender to press the fluorosilicone rubber into a 1 mm thick fluorosilicone sheet and the high temperature resistant silicone rubber into a 0.85 mm thick silicone tape. The high temperature resistant silicone can be prepared by yourself or purchased from the market.

[0059] (2) Cutting: Cut the pressed fluorosilicone sheet into 230×1200mm and the silicone tape into 200×1150mm;

[0060] (3) Tube blank molding: Fix the molding die on the molding machine, cover the molding die with the fluorosilicone sheet, adjust the overlap width to 10 mm ± 1 mm, and form a fluorosilicone rubber inner tube 1; wrap 4 layers of silicone tape around the fluorosilicone rubber inner tube 1 to form a high-temperature resistant silicone reinforcement layer 2; cover the high-temperature resistant silicone reinforcement layer 2 with a fluorosilicone rubber outer layer 3, and adjust the overlap width to 10 mm ± 1 mm to form a molded tube blank;

[0061] (4) Shaping: The formed tube blank is put on the shaping mold, wrapped with cellophane, and put into the oven for vulcanization at 160°C for 45 minutes to obtain the semi-finished product;

[0062] (5) Demolding: Remove the cellophane and the shaping mold from the vulcanized semi-finished product to form a vulcanized fluorosilicone rubber hose;

[0063] (6) Secondary vulcanization: The fluorosilicone rubber hose obtained in step (5) is placed in an oven at 160° C. for vulcanization for 4 hours to further improve the performance of the hose body. The fluorosilicone rubber hose has an inner diameter of 50 mm and an outer diameter of 60 mm, and can be used as a connecting hose between a turbocharger and an intercooler.

[0064] The cross section of the fluorosilicone rubber hose obtained in Example 4 is as follows Figure 1 As shown, the overlapping part (i.e. the overlapping part connecting the two sides) is not shown in the figure, and the high temperature resistant silicone reinforcement layer 4 is four layers.

Claims

1. A fluorosilicone rubber, characterized in that: The fluorosilicone rubber is prepared from the following components calculated in parts by weight: Fluorosilicone rubber: 50-70 parts; High temperature resistant flame retardant silicone rubber: 20-45 parts; Fumed silica: 30-40 parts; Dicumyl peroxide: 0.5-2 parts; Hydroxy silicone oil: 5-10 parts; 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane: 1 to 3 parts.

2. A method for preparing fluorosilicone rubber as claimed in claim 1, characterized in that: The preparation method comprises: (1) Mixing: The temperature of the kneader is set to 50°C to 60°C, and fluorosilicone rubber, high temperature flame retardant silicone rubber, fumed silica, dicumyl peroxide and hydroxy silicone oil are weighed according to the proportion and added into the kneader for uniform mixing to obtain a rubber material; (2) Plasticizing: The rubber material obtained by mixing in step (1) is placed on a two-roll open mill, plasticized until the rolls are completely wrapped, and the mixed rubber is prepared and left to stand for more than 10 hours. The roll temperature of the two-roll open mill is set at 40°C to 50°C; (3) Sulfur addition: the mixed rubber after the storage in step (2) is re-mixed on a two-roll mill to the wrap roll, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is added, and after being mixed evenly on the two-roll mill, a mixed rubber sheet is formed by rolling, namely, fluorosilicone rubber. The roll temperature of the two-roll mill is set at 40°C to 50°C.

3. A fluorosilicone rubber hose using the fluorosilicone rubber as claimed in claim 1 or the fluorosilicone rubber prepared by the method as claimed in claim 2, characterized in that: The fluorosilicone rubber hose comprises a fluorosilicone rubber inner tube, the fluorosilicone inner tube is coated with at least one layer of high-temperature resistant silicone reinforcement layer, and the high-temperature resistant silicone reinforcement layer is coated with a fluorosilicone rubber outer layer.

4. The fluorosilicone rubber hose according to claim 3, characterized in that: The overlap width of the fluorosilicone rubber inner tube and the fluorosilicone rubber outer layer is 10mm±1mm.

5. A method for preparing a fluorosilicone rubber hose as claimed in claim 4, characterized in that: (1) Calendering: According to the process requirements, a three-roll calender is used to press the fluorosilicone rubber into fluorosilicone sheets and the high temperature resistant silicone rubber into silicone tape; (2) Cutting: Cut the pressed fluorosilicone sheet and silicone tape into the size required by the process; (3) Tube blank molding: Fix the molding die on the molding machine, cover the fluorosilicone sheet on the molding die, adjust the overlap width, and form a fluorosilicone rubber inner tube; wrap a certain number of layers of silicone tape around the fluorosilicone rubber inner tube to form a high-temperature resistant silicone reinforcement layer; cover the high-temperature resistant silicone reinforcement layer with a fluorosilicone rubber outer layer, adjust the overlap width, and form a molded tube blank; (4) Shaping: The formed tube blank is put on the shaping mold, wrapped with cellophane, and put into the oven for vulcanization at 150-200°C for 40-50 minutes to obtain a semi-finished product; (5) Demolding: Remove the cellophane and the shaping mold from the vulcanized semi-finished product to form a vulcanized fluorosilicone rubber hose; (6) Secondary vulcanization: The fluorosilicone rubber hose obtained in step (5) is placed in an oven at 150-180° C. for vulcanization for 3-5 hours to obtain a finished fluorosilicone rubber hose.

6. A fluorosilicone rubber hose as claimed in claim 3 or 4 or a fluorosilicone rubber hose prepared by the method according to claim 5, used as a connecting hose in the connecting pipeline of a turbocharger system.

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