Rubber composition for prolonging scorching time of fluorosilicone rubber and preparation method thereof

Abstract

The invention relates to a rubber composition for prolonging scorching time of fluorosilicone rubber and a preparation method thereof. The composition comprises the following components in parts by weight: 100 parts of fluorosilicone raw rubber, 20-60 parts of filler, 30-60 parts of scorch retarder and 1-10 parts of structured control agent. The composition provided by the invention takes the organosiloxane compound as the scorch retarder, has the effect of prolonging the scorch time and storage period of the fluorosilicone rubber, can effectively prevent the early vulcanization phenomenon of the fluorosilicone rubber in the processing processes of mixing, calendering, extruding and the like, and is suitable for various industrial processing modes of mould pressing vulcanization, injection molding, extrusion molding and the like.

Description

Technical Field

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

[0002] Fluorosilicone rubber is widely used in military industry, automobile industry, aerospace industry, petrochemical industry, machinery and other fields due to its excellent oil resistance, heat resistance, weather resistance, electrical insulation, resilience and solvent resistance. Compared with other traditional rubbers, fluorosilicone rubber has better high temperature mechanical properties, cold resistance, compression set and processing performance. With the advancement of science and technology, the application of fluorosilicone rubber has attracted more and more attention and has gradually become an indispensable new polymer material in national defense and national economy. However, during the mixing, compounding or processing of fluorosilicone rubber, due to the effect of mechanical shear force, it is very easy to cause the peroxide used as a crosslinking agent to decompose prematurely, and then crosslink with the vinyl in the fluorosilicone rubber, thereby inducing early vulcanization. In addition, under high vulcanization temperature conditions, scorch phenomenon, that is, early vulcanization phenomenon, is also prone to occur, which reduces the flow characteristics of polymers, rubbers or elastomers and affects the quality of the final product. Generally speaking, the longer the scorch time, the more favorable it is for the mixing, processing operation and storage of rubber.

[0003] In the rubber processing, in order to avoid scorching and make the rubber have better in-mold fluidity, the method of adding scorch retarder is usually adopted to solve the problem. For example: Chinese patent document CN115551927A discloses a scorch-protected organic peroxide formulation, which adopts a scorch delay additive composed of at least one of vitamin K1 (phylloquinone), K2 (methyl menaquinone), K3 (methyl menaquinone), olive leaf oil (oleuropein), and a mixture thereof, added to fluorosilicone rubber, silicone rubber and other rubbers with peroxide as the vulcanization system to extend the scorch time of the rubber. Chinese patent CN101023127A proposes a composition containing nitroxide and at least one organic peroxide, which is added to thermoplastic polymers and / or elastomeric polymers to extend their scorch time. U.S. Patent US5245084A provides a specific composition composed of organic peroxide, hydroquinone derivatives and crosslinking accelerators, which is suitable for polymers including polyolefins and elastomers, so that the mixture can maintain or improve crosslinking efficiency and product quality while extending the scorch time. However, the compounds added in the above prior art have poor compatibility with fluorosilicone rubber and are easily precipitated from the rubber during storage, resulting in failure. In addition, since the structures of these substances are quite different from the Si-O chain of fluorosilicone rubber, it is very easy to cause the mechanical properties, heat resistance and other properties of fluorosilicone rubber to deteriorate.

[0004] Therefore, it is of great significance to develop a rubber composition that can prolong the scorch time of fluorosilicone rubber, prolong the storage time of fluorosilicone rubber and improve the vulcanization processing performance without affecting the performance of fluorosilicone rubber. To this end, the present invention is proposed. Summary of the invention

[0005] In view of the above-mentioned state of the prior art, the inventors of the present invention have conducted extensive research on the scorch of fluorosilicone rubber and found that the use of organosiloxane compounds as scorch inhibitors not only has good compatibility with fluorosilicone rubber, but also can preferentially react with crosslinking agents during the storage and high-temperature vulcanization of fluorosilicone rubber, thereby delaying the vulcanization process of fluorosilicone rubber, thereby achieving the purpose of extending the scorch time and increasing the safe storage period. The present invention is completed based on the above-mentioned 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] The second object of the present invention is to provide a rubber composition and a preparation method for extending the scorch time of fluorosilicone rubber. The composition uses an organosiloxane compound as a scorch retarder, which can effectively prevent the early vulcanization of fluorosilicone rubber during processing such as mixing, calendering, and extrusion, thereby improving the quality of the mixed rubber. Adding the rubber composition to fluorosilicone rubber can significantly increase the storage time and vulcanization operation time, and is suitable for various industrial processing methods such as compression vulcanization, injection molding, and extrusion molding.

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

[0009] The organic siloxane compound is used as a scorch retarder for fluorosilicone rubber, wherein the organic siloxane 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 shown in 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 of 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 of 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 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 a 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] Further preferably, the molecular weight of the fluorosilicone rubber is 50×10 4 ~100×10 4 g / mol; the vinyl content of the fluorosilicone raw 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 structure 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 prolonging 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 the 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 heat to 80-120°C, perform vacuum treatment to remove oligomers and moisture, and 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 prolonging the scorch time of fluorosilicone rubber of the present invention mainly comprises an organosilicon siloxane compound. Such a compound as a scorch retarder 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 inhibitor 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 organic siloxane compound as a scorch retarder for fluorosilicone rubber. The organic siloxane compound is at least one of a vinyl-terminated siloxane and a vinyl cyclosiloxane.

[0033] According to the present invention, the vinyl-terminated siloxane is a conventional raw material, which can be purchased from the market or prepared according to the prior art.

[0034] In one or more preferred embodiments, the vinyl-terminated siloxane has a structure shown in 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 of 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 vinyl cyclosiloxane is a conventional raw material, which can be purchased from the market or prepared according to the prior art.

[0040] In one or more preferred embodiments, the vinyl cyclosiloxane has a structure shown in general 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 of 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 above-mentioned anti-scorch agent terminal vinyl siloxane or / and vinyl cyclosiloxane is an organic siloxane compound, which has good compatibility with fluorosilicone rubber and is not easy to precipitate during storage. During the high-temperature vulcanization process of fluorosilicone rubber, due to the smaller steric hindrance or electronic effect of the vinyl group relative to the vinyl group linked to the fluorosilicone rubber, it shows higher reactivity. During the rubber vulcanization process, it will preferentially react with the crosslinking agent, thereby delaying the vulcanization process of the fluorosilicone rubber, achieving the effect of extending the scorch time and improving 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 structuring control agent.

[0048] In one or more preferred embodiments, the fluorosilicone rubber is polymethyltrifluoropropylsiloxane having a 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 raw 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 raw 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 structure 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 the 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 prolonging 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 the 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 heat to 80-120°C, perform vacuum treatment to remove oligomers and moisture, and 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 described by the following specific examples, but it does not constitute any limitation to the present invention. The raw materials used in the examples are all conventional raw materials, commercial products, and the equipment used is all conventional equipment.

[0061] In Examples 1-4 and Comparative Examples 1-5, a rubber composition for prolonging the scorch time of fluorosilicone rubber is prepared, and the structural formula of the fluorosilicone raw rubber used is as follows:

[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 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. 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 prolonging the scorch time of fluorosilicone rubber comprises the following steps:

[0068] Add 100 parts of fluorosilicone raw rubber and 4 parts of hydroxy silicone oil into a rubber mixing equipment, control the temperature below 60°C, add 40 parts of 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane and 35 parts of fumed silica in 4 times under the protection of inert gas, mix thoroughly for 2 hours until uniform, then raise the temperature to 100°C for vacuum treatment to remove oligomers and moisture, and obtain 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 by weight: 100 parts of fluorosilicone raw rubber, 40 parts of precipitated white carbon black, 40 parts of 1,5-divinyl-hexamethyltrisiloxane, and 6 parts of hexamethyldisilazane.

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

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

[0073] Add 100 parts of fluorosilicone raw rubber and 6 parts of hexamethyldisilazane into a rubber mixing equipment, control the temperature below 60°C, add 40 parts of 1,5-divinyl-hexamethyltrisiloxane and 40 parts of precipitated silica in 4 batches under the protection of inert gas, mix thoroughly for 2 hours until uniform, then raise the temperature to 100°C for vacuum treatment to remove oligomers and moisture, and obtain a rubber composition for extending the scorch time of fluorosilicone rubber.

[0074] Example 3

[0075] A rubber composition for prolonging the scorch time of fluorosilicone rubber comprises the following components by weight: 100 parts of fluorosilicone raw rubber, 40 parts of calcium carbonate, 35 parts of hexavinyl disiloxane and 2 parts of hydroxy fluorosilicone oil.

[0076] The fluorosilicone rubber has a vinyl content of 0.2 mol% and a molecular weight of 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 prolonging the scorch time of fluorosilicone rubber comprises the following steps:

[0078] Add 100 parts of fluorosilicone raw rubber and 2 parts of hydroxy fluorosilicone oil into a rubber mixing equipment, control the temperature below 60°C, add 35 parts of hexavinyl disiloxane and 40 parts of calcium carbonate in 4 times under the protection of inert gas, mix thoroughly for 2 hours until uniform, then raise the temperature to 100°C for vacuum treatment to remove oligomers and moisture, and obtain 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 by weight: 100 parts of fluorosilicone raw rubber, 40 parts of diatomaceous earth, 45 parts of polyfluorosilicone, and 2 parts of trifluoropropylcyclotrisilazane.

[0081] The fluorosilicone rubber has a vinyl content of 0.05 mol% and a molecular weight of 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 prolonging the scorch time of fluorosilicone rubber comprises the following steps:

[0085] Add 100 parts of fluorosilicone raw rubber and 2 parts of trifluoropropylcyclotrisilazane to a rubber mixing equipment, control the temperature below 60°C, add 45 parts of a vinyl-terminated polyfluorosilicone polymer as shown in the structural formula (IV) and 40 parts of diatomaceous earth in 4 portions under the protection of an inert gas, mix thoroughly for 2 hours until uniform, then raise the temperature to 100°C for vacuum treatment to remove oligomers and moisture, and thus obtain a rubber composition for extending the scorch time of fluorosilicone rubber.

[0086] Comparative Example 1

[0087] As described in Example 1, the difference is 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 anti-scorch agent 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, and the specific steps were as follows:

[0099] (1) Take 100g of fluorosilicone rubber mixture 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 until it is uniform.

[0100] (2) Take 1 part of the rubber composition for prolonging 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, thin it until it is uniform, adjust the roller distance to 2 mm, and put it down.

[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 results of the embodiments 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] From the comparative analysis of the above experimental data, it can be seen that the rubber composition for extending the scorch time of fluorosilicone rubber (Examples 1 to 4) prepared according to the method of the present invention significantly extends its scorch time after adding fluorosilicone rubber. In contrast, the methylsiloxane used in Comparative Examples 1 to 2, the ethylsiloxane used in Comparative Example 3, and the hydroxyl-terminated siloxane added in Comparative Example 5, all failed to observe similar effects.

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

Claims

1. Use of an organosiloxane compound as a scorch retarder for fluorosilicone rubber, wherein the organosiloxane compound is at least one of a vinyl-terminated siloxane and a vinyl cyclosiloxane.

2. The use according to claim 1, characterized in that The vinyl-terminated siloxane has a structure shown in general formula (II): 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 of 0 to 6; Preferably, R3 is selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl or trifluoropropyl; R4 and R5 are each selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl or trifluoropropyl.

3. The use according to claim 1, characterized in that The vinyl cyclosiloxane has a structure shown in the general formula (III): 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 of 3 to 6; Preferably, R6 is selected from methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, isooctyl, decyl, phenyl, vinyl or trifluoropropyl.

4. A rubber composition for extending the scorch time of fluorosilicone rubber, comprising using the organosiloxane compound according to any one of claims 1 to 3 as a scorch retarder, characterized in that: By weight, it includes the following components: 100 parts of fluorosilicone raw rubber, 20-60 parts of filler, 30-60 parts of scorch retarder, 1-10 parts of structuring control agent.

5. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 4, characterized in that: The fluorosilicone rubber is polymethyltrifluoropropylsiloxane, having a structure shown in general formula (I): In the general formula (I), R1 and R2 are each independently selected from a methyl group, a vinyl group or a hydroxyl group, x is an integer ≥3000, and y is an integer of 1-50.

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

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

8. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 4, 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.

9. The rubber composition for prolonging the scorch time of fluorosilicone rubber according to claim 4, characterized in that: The structural control agent is one or a combination of two or more of hydroxy silicone oil, hydroxy fluorosilicone oil, hexamethyldisilazane, and trifluoropropylmethylcyclotrisilazane.

10. A method for preparing a rubber composition for prolonging the scorch time of fluorosilicone rubber according to any one of claims 4 to 9, comprising the following steps: Add 100 parts of fluorosilicone raw rubber, 30-60 parts of scorch retarder, and 1-10 parts of structuring control agent into the 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 heat to 80-120°C, perform vacuum treatment to remove oligomers and moisture, and obtain a rubber composition for extending the scorch time of fluorosilicone rubber.

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