Rubber composition for extending scorch time of fluorosilicone rubber and preparation method thereof

Abstract

The present invention relates to a rubber composition for extending the scorch time of fluorosilicone rubber and a preparation method. The composition comprises the following components by weight: 100 parts of fluorosilicone raw rubber, 20-60 parts of filler, 30-60 parts of a scorch retarder, and 1-10 parts of a structuring control agent. The composition, which uses an organosiloxane compound as a scorch retarder, has the effect of extending the scorch time and storage period of fluorosilicone rubber. It can effectively prevent premature vulcanization of fluorosilicone rubber during processing processes such as mixing, calendering, and extrusion. The composition is suitable for various industrial processing methods, including compression vulcanization, injection molding, and extrusion molding.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and particularly relates to a rubber composition for prolonging the scorch time of fluorosilicone rubber and a preparation method thereof. Background Art

[0002] Fluorosilicone rubber (FSR) is widely used in the military, automotive, aerospace, petrochemical, and machinery industries due to its excellent oil resistance, heat resistance, weather resistance, electrical insulation, resilience, and solvent resistance. Compared to other traditional rubbers, FSR offers superior high-temperature mechanical properties, cold resistance, compression set, and processability. With technological advancements, the application of FSR is gaining increasing attention, and it is gradually becoming an indispensable new polymer material in national defense and the national economy. However, during the mixing, compounding, and processing of FSR, mechanical shear forces can easily cause the peroxide used as a crosslinking agent to prematurely decompose, leading to crosslinking reactions with the vinyl groups in the FSR, resulting in premature vulcanization. Furthermore, at higher vulcanization temperatures, scorch (premature vulcanization) is more likely to occur, reducing the flow properties of the polymer, rubber, or elastomer, affecting the quality of the final product. Generally speaking, a longer scorch time is associated with better mixing, processing, and storage of the rubber.

[0003] In rubber processing, scorch retarder additives are often added to prevent scorch and improve mold fluidity. For example, Chinese patent document CN115551927A discloses a scorch-protective organic peroxide formulation. This formulation uses a scorch retarder additive consisting of at least one of vitamin K1 (phylloquinone), K2 (methyl menaquinone), K3 (methyl menaquinone), olive leaf oil (oleuropein), and mixtures thereof, added to peroxide-vulcanized rubbers such as fluorosilicone rubber and silicone rubber to extend the scorch time of the rubber. Chinese patent CN101023127A proposes a composition containing a nitroxide and at least one organic peroxide. This composition, when added to thermoplastic polymers and / or elastomeric polymers, can extend their scorch time. U.S. Patent No. 5245084A provides a specific composition consisting of an organic peroxide, a hydroquinone derivative, and a crosslinking accelerator. This composition is suitable for polymers including polyolefins and elastomers, allowing the mixture to extend the scorch time while maintaining or improving crosslinking efficiency and product quality. However, the compounds added in the above-mentioned prior art have poor compatibility with fluorosilicone rubber and are easily precipitated from the rubber during storage, causing failure. Furthermore, because the structures of these substances differ significantly from the Si-O chains of fluorosilicone rubber, they can easily degrade the mechanical properties and heat resistance of the rubber.

[0004] Therefore, it is of great significance to develop a rubber composition that can prolong the scorch time of fluorosilicone rubber, thereby extending the storage time of fluorosilicone rubber and improving the vulcanization processing performance without affecting the performance of fluorosilicone rubber. Summary of the Invention

[0005] In light of the aforementioned state of the art, the inventors of the present invention conducted extensive research on fluorosilicone rubber scorch prevention and discovered that organosiloxane compounds, when used as scorch retardants, not only exhibit good compatibility with fluorosilicone rubber but also preferentially react with crosslinkers during storage and high-temperature vulcanization of the rubber, thereby slowing the vulcanization process and extending the scorch time and safe storage period. The present invention is based on these findings.

[0006] Therefore, an object of the present invention is to provide a use of an organosiloxane compound as a scorch retarder for fluorosilicone rubber.

[0007] A second objective of the present invention is to provide a rubber composition and preparation method for extending the scorch time of fluorosilicone rubber. This composition, which uses an organosiloxane compound as a scorch retarder, effectively prevents premature vulcanization of fluorosilicone rubber during processing, such as mixing, calendering, and extrusion, thereby improving the quality of the rubber mix. Adding this rubber composition to fluorosilicone rubber significantly increases its storage life and vulcanization cycle time, making it suitable for a variety of industrial processing methods, including compression vulcanization, injection molding, and extrusion.

[0008] The technical solution for achieving the above-mentioned invention object can be summarized as follows:

[0009] The organosiloxane compound is used as a scorch retarder for fluorosilicone rubber, wherein the organosiloxane compound is at least one of vinyl-terminated siloxane and vinyl cyclosiloxane.

[0010] According to the present invention, preferably, the vinyl-terminated siloxane has a structure represented by general formula (II):

[0011]

[0012] In the general formula (II), R3 is selected from a saturated hydrocarbon group or an aromatic group, R4 and R5 are each selected from a saturated hydrocarbon group, an unsaturated hydrocarbon group or an aromatic group, and m is an integer from 0 to 6;

[0013] Further preferably, R3 is selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl or trifluoropropyl; more preferably, R3 is selected from methyl, ethyl, trifluoropropyl;

[0014] R4 and R5 are each selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl or trifluoropropyl; more preferably, R4 and R5 are selected from methyl, ethyl, propyl and vinyl.

[0015] According to the present invention, preferably, the vinyl cyclosiloxane has a structure shown in general formula (III):

[0016]

[0017] In the general formula (III), R6 is selected from a saturated hydrocarbon group, an unsaturated hydrocarbon group or an aromatic group; n is an integer from 3 to 6;

[0018] Further preferably, R6 is selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl, vinyl or trifluoropropyl; more preferably, R6 is selected from methyl, ethyl, vinyl or trifluoropropyl.

[0019] According to the present invention, a rubber composition for extending the scorch time of fluorosilicone rubber includes a scorch retarder using the above-mentioned compound, and includes the following components in parts by weight: 100 parts of fluorosilicone raw rubber, 20 to 60 parts of filler, 30 to 60 parts of scorch retarder, and 1 to 10 parts of structuring control agent.

[0020] According to the present invention, preferably, the fluorosilicone rubber is polymethyltrifluoropropylsiloxane having the structure shown in general formula (I):

[0021]

[0022] In the general formula (I), R1 and R2 are each independently selected from methyl, vinyl or hydroxyl, x is an integer ≥ 3000, and y is an integer from 1 to 50;

[0023] More preferably, the molecular weight of the fluorosilicone rubber is 50×10 4 ~100×10 4 g / mol; the vinyl content of the fluorosilicone rubber is 0.01 to 0.5 mol%.

[0024] According to the present invention, preferably, the filler is one or a combination of two or more of fumed silica, precipitated silica, treated silica, calcium carbonate, and diatomaceous earth.

[0025] According to the present invention, preferably, the structuring control agent is one or a combination of two or more of hydroxy silicone oil, hydroxy fluorosilicone oil, hexamethyldisilazane, and trifluoropropylmethylcyclotrisilazane.

[0026] According to the present invention, the method for preparing the rubber composition for extending the scorch time of fluorosilicone rubber comprises the following steps:

[0027] Add 100 parts of fluorosilicone raw rubber, 30-60 parts of scorch retarder, and 1-10 parts of structuring control agent into a rubber mixing device, add 20-60 parts of filler in batches under the protection of inert gas below 60-80°C, mix thoroughly for 2-4 hours until uniform, then raise the temperature to 80-120°C, perform vacuum treatment to remove oligomers and moisture, and thus obtain a rubber composition for extending the scorch time of fluorosilicone rubber.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The rubber composition for extending the scorch time of fluorosilicone rubber of the present invention is mainly composed of an organosilicon siloxane compound. As a scorch retarder, this type of compound not only has good compatibility with fluorosilicone rubber, but also has the advantage of not being easily precipitated during storage, and does not affect the oil resistance and basic properties of fluorosilicone rubber.

[0030] 2. The rubber composition of the present invention is used to extend the scorch time of fluorosilicone rubber. During the high-temperature vulcanization process of fluorosilicone rubber, the effective ingredient scorch retarder in the composition will preferentially react with the cross-linking agent, thereby delaying the vulcanization process of the fluorosilicone rubber, thereby extending the scorch time and improving the safe storage period.

[0031] 3. The rubber composition for prolonging the scorch time of fluorosilicone rubber provided by the present invention is suitable for molded vulcanized fluorosilicone rubber, injection molded vulcanized fluorosilicone rubber, extrusion molded vulcanized fluorosilicone rubber, etc. It can be easily mixed with fluorosilicone rubber, is simple to operate, has strong applicability, low cost, and can be applied to industrial-scale production. DETAILED DESCRIPTION

[0032] The present invention provides use of an organosiloxane compound as a fluorosilicone rubber scorch retarder. The organosiloxane compound is at least one of vinyl-terminated siloxane and vinylcyclosiloxane.

[0033] According to the present invention, the vinyl-terminated siloxane is a conventional raw material, which can be purchased commercially or prepared according to existing technology.

[0034] In one or more preferred embodiments, the vinyl-terminated siloxane has a structure represented by general formula (II):

[0035]

[0036] In the general formula (II), R3 is selected from a saturated hydrocarbon group or an aromatic group, R4 and R5 are each selected from a saturated hydrocarbon group, an unsaturated hydrocarbon group or an aromatic group, and m is an integer from 0 to 6;

[0037] Preferably, R3 is selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl or trifluoropropyl; More preferably, R3 is selected from methyl, ethyl, trifluoropropyl;

[0038] R4 and R5 are each selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl or trifluoropropyl; more preferably, R4 and R5 are selected from methyl, ethyl, propyl and vinyl.

[0039] According to the present invention, the vinylcyclosiloxane is a conventional raw material, which can be purchased commercially or prepared according to existing technology.

[0040] In one or more preferred embodiments, the vinyl cyclosiloxane has a structure shown in formula (III):

[0041]

[0042] In the general formula (III), R6 is selected from a saturated hydrocarbon group, an unsaturated hydrocarbon group or an aromatic group; n is an integer from 3 to 6;

[0043] Further preferably, R6 is selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl, vinyl or trifluoropropyl; more preferably, R6 is selected from methyl, ethyl, vinyl or trifluoropropyl.

[0044] In one or more preferred embodiments, the organosiloxane compound is at least one of 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 1,5-divinyl-hexamethyltrisiloxane, hexavinyldisiloxane, and polyfluorosiloxane, and the polyfluorosiloxane is a vinyl-terminated polyfluorosiloxane polymer having the structural formula (IV);

[0045]

[0046] According to the present invention, the vinyl-terminated siloxane and / or vinyl-cyclosiloxane as the scorch retarder is an organosiloxane compound that has good compatibility with fluorosilicone rubber and is unlikely to precipitate during storage. During the high-temperature vulcanization process of fluorosilicone rubber, the vinyl group exhibits higher reactivity than the vinyl group linked to the fluorosilicone rubber due to factors such as smaller steric hindrance or electronic effects. During the rubber vulcanization process, the vinyl group preferentially reacts with the crosslinking agent, thereby delaying the vulcanization process of the fluorosilicone rubber, thereby extending the scorch time and increasing the safe storage period.

[0047] According to the present invention, a rubber composition for extending the scorch time of fluorosilicone rubber is also provided, comprising a scorch retarder using the above-mentioned compound, and comprising the following components in parts by weight: 100 parts of fluorosilicone raw rubber, 20 to 60 parts of filler, 30 to 60 parts of scorch retarder, and 1 to 10 parts of a structuring control agent.

[0048] In one or more preferred embodiments, the fluorosilicone rubber is polymethyltrifluoropropylsiloxane having the structure shown in general formula (I):

[0049]

[0050] In the general formula (I), R1 and R2 are each independently selected from methyl, vinyl or hydroxyl, x is an integer ≥ 3000, and y is an integer from 1 to 50;

[0051] Preferably, the molecular weight of the fluorosilicone rubber is 50×10 4 ~100×10 4 g / mol; the vinyl content of the fluorosilicone rubber is 0.01 to 0.5 mol%;

[0052] According to the present invention, the filler plays a thickening role in the rubber composition and is used to improve the dispersibility and stability of the scorch retarder in the fluorosilicone rubber.

[0053] In one or more preferred embodiments, the filler is one or a combination of two or more of fumed silica, precipitated silica, treated silica, calcium carbonate, and diatomaceous earth.

[0054] According to the present invention, the structuring control agent is used to prevent the Si-OH groups on the surface of the filler from forming hydrogen bonds with the Si-O bonds in the fluorosilicone rubber molecules or the Si-OH groups at the chain ends, resulting in physical adsorption and chemical bonding, thereby causing the rubber composition for extending the scorch time of fluorosilicone rubber to lose its processing performance during storage.

[0055] In one or more preferred embodiments, the structure control agent is one or a combination of two or more of hydroxy silicone oil, hydroxy fluorosilicone oil, hexamethyldisilazane, and trifluoropropylmethylcyclotrisilazane;

[0056] Preferably, the kinematic viscosity of the hydroxy silicone oil at 25°C is 20 to 100 mm 2 / s;

[0057] The kinematic viscosity of hydroxy fluorosilicone oil at 25°C is 100-300 mm 2 / s.

[0058] According to the present invention, the method for preparing the rubber composition for extending the scorch time of fluorosilicone rubber comprises the following steps:

[0059] Add 100 parts of fluorosilicone raw rubber, 30-60 parts of scorch retarder, and 1-10 parts of structuring control agent into a rubber mixing device, add 20-60 parts of filler in batches under the protection of inert gas below 60-80°C, mix thoroughly for 2-4 hours until uniform, then raise the temperature to 80-120°C, perform vacuum treatment to remove oligomers and moisture, and thus obtain a rubber composition for extending the scorch time of fluorosilicone rubber.

[0060] In order to better reflect the advantages of the present invention, the present invention is further illustrated by the following specific examples, which do not constitute any limitation of the present invention. The raw materials used in the examples are all conventional raw materials, commercially available products, and the equipment used is all conventional equipment.

[0061] In Examples 1-4 and Comparative Examples 1-5, rubber compositions for prolonging the scorch time of fluorosilicone rubber were prepared. The structural formula of the fluorosilicone raw rubber used is shown below:

[0062]

[0063] Wherein, x is an integer ≥3000, y is an integer from 1 to 50, and the molecular weight is 50×10 4 ~100×10 4 g / mol, and the vinyl content is 0.01 to 0.5 mol%.

[0064] Example 1

[0065] A rubber composition for extending the scorch time of fluorosilicone rubber comprises the following components, measured in parts by weight: 100 parts of fluorosilicone raw rubber, 35 parts of fumed silica, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, and 4 parts of hydroxy silicone oil.

[0066] The vinyl content of the fluorosilicone rubber is 0.1 mol%, the molecular weight is 52×104 g / mol, and the kinematic viscosity of the hydroxy silicone oil at 25°C is 25-100 mm 2 / s.

[0067] The method for preparing the rubber composition for extending the scorch time of fluorosilicone rubber comprises the following steps:

[0068] To a rubber mixing device, 100 parts of fluorosilicone raw rubber and 4 parts of hydroxy silicone oil are added, the temperature is controlled below 60°C, and under the protection of inert gas, 40 parts of 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane and 35 parts of fumed silica are added in 4 portions. The mixture is thoroughly mixed for 2 hours until uniform, and then the temperature is raised to 100°C and vacuumed to remove oligomers and moisture, thereby obtaining a rubber composition for extending the scorch time of fluorosilicone rubber.

[0069] Example 2

[0070] A rubber composition for extending the scorch time of fluorosilicone rubber comprises the following components, measured in parts by weight: 100 parts of fluorosilicone raw rubber, 40 parts of precipitated silica, 40 parts of 1,5-divinyl-hexamethyltrisiloxane, and 6 parts of hexamethyldisilazane.

[0071] The vinyl content of the fluorosilicone rubber is 0.05 mol%, and the molecular weight is 61×10 4 g / mol.

[0072] The method for preparing the rubber composition for extending the scorch time of fluorosilicone rubber comprises the following steps:

[0073] To a rubber mixing device, 100 parts of fluorosilicone raw rubber and 6 parts of hexamethyldisilazane are added, the temperature is controlled below 60°C, and under the protection of inert gas, 40 parts of 1,5-divinyl-hexamethyltrisiloxane and 40 parts of precipitated silica are added in 4 batches. The mixture is thoroughly mixed for 2 hours until uniform, and then the temperature is raised to 100°C and vacuumed to remove oligomers and moisture, thereby obtaining a rubber composition for extending the scorch time of fluorosilicone rubber.

[0074] Example 3

[0075] A rubber composition for extending the scorch time of fluorosilicone rubber comprises the following components in parts by weight: 100 parts of fluorosilicone raw rubber, 40 parts of calcium carbonate, 35 parts of hexavinyldisiloxane, and 2 parts of hydroxyfluorosilicone oil.

[0076] The vinyl content of the fluorosilicone rubber is 0.2 mol%, and the molecular weight is 81×10 4 g / mol. The kinematic viscosity of hydroxyfluorosilicone oil at 25°C is 146 mm 2 / s

[0077] The method for preparing the rubber composition for extending the scorch time of fluorosilicone rubber comprises the following steps:

[0078] To a rubber mixing device, 100 parts of fluorosilicone raw rubber and 2 parts of hydroxy fluorosilicone oil are added, with the temperature controlled below 60°C. Under the protection of inert gas, 35 parts of hexavinyldisiloxane and 40 parts of calcium carbonate are added in 4 portions. The mixture is thoroughly mixed for 2 hours until uniform. The mixture is then heated to 100°C and vacuumed to remove oligomers and moisture, thereby obtaining a rubber composition for extending the scorch time of fluorosilicone rubber.

[0079] Example 4

[0080] A rubber composition for prolonging the scorch time of fluorosilicone rubber comprises the following components in parts by weight: 100 parts of fluorosilicone raw rubber, 40 parts of diatomaceous earth, 45 parts of polyfluorosiloxane, and 2 parts of trifluoropropylcyclotrisilazane.

[0081] The vinyl content of the fluorosilicone rubber is 0.05 mol%, and the molecular weight is 61×10 4 g / mol.

[0082] The polyfluorosilicone is a vinyl-terminated polyfluorosilicone polymer having the structural formula (IV).

[0083]

[0084] The method for preparing the rubber composition for extending the scorch time of fluorosilicone rubber comprises the following steps:

[0085] To a rubber mixing device, 100 parts of fluorosilicone rubber and 2 parts of trifluoropropylcyclotrisilazane are added, with the temperature controlled below 60°C. Under the protection of inert gas, 45 parts of a vinyl-terminated polyfluorosilicone polymer as shown in structural formula (IV) and 40 parts of diatomaceous earth are added in four portions. The mixture is thoroughly mixed for 2 hours until uniform, and then the temperature is raised to 100°C and vacuumed to remove oligomers and moisture, thereby obtaining a rubber composition for extending the scorch time of fluorosilicone rubber.

[0086] Comparative Example 1

[0087] As described in Example 1, except that the anti-scorch agent is octamethylcyclotetrasiloxane.

[0088] Comparative Example 2

[0089] As described in Example 2, except that the anti-scorch agent is octamethyltrisiloxane.

[0090] Comparative Example 3

[0091] As described in Example 3, except that the scorch retarder is hexaethylcyclotrisiloxane.

[0092] Comparative Example 4

[0093] As described in Example 3, except that no scorch retarder is added to the composition.

[0094] Comparative Example 5

[0095] As described in Example 4, except that the polyfluorosilicone is a compound having a structure represented by formula (V).

[0096]

[0097] Test example

[0098] The rubber compositions for prolonging the scorch time of fluorosilicone rubber prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were added to fluorosilicone rubber to verify the vulcanization performance. The specific steps are as follows:

[0099] (1) Take 100g of fluorosilicone rubber mix and slowly add 0.8 parts of crosslinking agent 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane (DBPH) on an open mill. Mix for 1 to 3 minutes, adjust the roller distance to 0.5mm, and pass it through until it is uniform.

[0100] (2) Take 1 part of the above rubber composition for extending the scorch time of fluorosilicone rubber, slowly add it to the fluorosilicone rubber prepared in the previous step in an open mill, mix for 1 to 3 minutes, adjust the roller distance to 0.5 mm, pass it until it is uniform, adjust the roller distance to 2 mm, and take it off.

[0101] (3) Take 6 to 8 g of the test sample obtained in the previous step, place it in a vulcanizer, and test the scorch time and process positive vulcanization time according to GB / T16584 "Determination of vulcanization characteristics of rubber using a rotorless vulcanizer".

[0102] The performance data of the examples and comparative examples are shown in Table 1.

[0103] Table 1 Performance data of Examples 1 to 4 and Comparative Examples 1 to 5

[0104]

[0105] Comparative analysis of the experimental data above shows that the rubber compositions for extending the scorch time of fluorosilicone rubber (Examples 1-4) prepared according to the present invention significantly prolonged their scorch time after the addition of fluorosilicone rubber. In contrast, similar effects were not observed with the methylsiloxane used in Comparative Examples 1-2, the ethylsiloxane used in Comparative Example 3, and the hydroxyl-terminated siloxane added in Comparative Example 5.

[0106] The above embodiments are used to illustrate the present invention, but the present invention is not limited to the above examples. Modifications, additions and substitutions made by those skilled in the art to the contents of the present invention also fall within the scope of protection of the present invention.

Claims

1. Use of an organosiloxane compound as a high-temperature vulcanization retarder for fluorosilicone rubber, wherein the organosiloxane compound is at least one of a vinyl-terminated siloxane and a vinyl cyclosiloxane; The vinyl-terminated siloxane has a structure shown in general formula (II): ； In the general formula (II), R3 is selected from methyl, ethyl, propyl, butyl, hexyl, 2-ethylhexyl, octyl, decyl, phenyl or trifluoropropyl; R4 and R5 are each selected from methyl, ethyl, propyl, butyl, hexyl, 2-ethylhexyl, octyl, decyl, phenyl or trifluoropropyl, and m is an integer from 0 to 6; The vinyl cyclosiloxane has a structure shown in the general formula (III): ； In the general formula (III), R6 is selected from methyl, ethyl, propyl, butyl, hexyl, 2-ethylhexyl, octyl, decyl, phenyl, vinyl or trifluoropropyl, and n is an integer of 3 to 6; Fluorosilicone rubber is polymethyltrifluoropropylsiloxane, which has the structure shown in the general formula (I): ； In the general formula (I), R1 and R2 are each independently selected from methyl, vinyl or hydroxyl, x is an integer ≥ 3000, and y is an integer from 1 to 50; During the high-temperature vulcanization process of fluorosilicone rubber, it preferentially reacts with the cross-linking agent, thereby delaying the vulcanization process of fluorosilicone rubber, thereby extending the scorch time and increasing the safe storage period.

2. A rubber composition for extending the scorch time of fluorosilicone rubber, comprising the use of the organosiloxane compound described in claim 1 as a high-temperature vulcanization retardant and the fluorosilicone rubber raw rubber described in claim 1, characterized in that: Calculated by weight, it includes the following components: 100 parts of fluorosilicone rubber, 20-60 parts of filler, 30-60 parts of high temperature vulcanization scorch retarder, 1-10 parts of structuring control agent.

3. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 2, characterized in that The molecular weight of the fluorosilicone rubber is 50×10 4 ~100×10 4 g / mol.

4. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 2, characterized in that The vinyl content of the fluorosilicone rubber is 0.01-0.5 mol%.

5. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 2, characterized in that The filler is one or a combination of two or more of fumed silica, precipitated silica, treated silica, calcium carbonate and diatomaceous earth.

6. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 2, characterized in that The structuring control agent is one or a combination of two or more of hydroxy silicone oil, hydroxy fluorosilicone oil, hexamethyldisilazane, and trifluoropropylmethylcyclotrisilazane.

7. A method for preparing a rubber composition for extending the scorch time of fluorosilicone rubber according to any one of claims 2 to 6, comprising the following steps: Add 100 parts of fluorosilicone rubber raw rubber, 30-60 parts of scorch retarder, and 1-10 parts of structuring control agent into a rubber mixing equipment, add 20-60 parts of filler in batches under the protection of inert gas below 60-80°C, mix thoroughly for 2-4 hours until uniform, then raise the temperature to 80-120°C, perform vacuum treatment to remove oligomers and moisture, and thus obtain a rubber composition for extending the scorch time of fluorosilicone rubber.

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