Preparation method of rubber composition and bush for aircraft

Abstract

The invention relates to a preparation method of a rubber composition and a bushing for an aircraft, belongs to the technical field of rubber products and chemical engineering, and solves the problems of low tearing strength, poor dynamic performance, no cutting resistance and relatively high density of a rubber composition prepared by adopting an existing method. The preparation method comprises the following steps: 1, softening rubber, adding a reinforcing filler, an anti-aging agent, a vulcanizing activator, a silane coupling agent, phenolic resin and high styrene resin in proportion, mixing, and discharging rubber to obtain a mixture; 2, standing the mixture obtained in the step 1, adding a vulcanizing agent, a vulcanization accelerator and a formaldehyde donor, and mixing to obtain a rubber compound; 3, vulcanizing and crosslinking the rubber compound obtained in the step 2 to obtain a rubber bushing composition; in the step 3, the vulcanization temperature is 135 to 170 DEG C, and the vulcanization time is 5 to 100 minutes.

Description

Technical Field

[0001] The invention relates to the technical field of rubber products and chemical industry, and in particular to a method for preparing a rubber composition and a bushing for an aircraft. Background Art

[0002] Bushings are an essential component required in aircraft, especially for the hub position, which is demanding and frequently used. The introduction of bushings can avoid rigid collisions between metals and reduce the entry of large particles of sand and gravel into the interior. At the same time, bushings also need to withstand certain loads and dynamic stresses, especially during the critical processes of adjusting the aircraft's attitude, accelerating and decelerating, and taking off and landing.

[0003] The bushings used in traditional aircraft are mostly made of polyurethane rubber, because the bushings only need to fulfill the role of cushioning. That is to say, the high hardness, high modulus and low friction coefficient of the material provide the bushing products with corresponding high rigidity and wear resistance.

[0004] With the development of technology, the requirements for bushings are gradually increasing. While meeting the previous needs, they have added multiple properties such as cut resistance, tear resistance and excellent dynamic performance.

[0005] The rubber composition prepared by the existing method has low tear strength and is not resistant to cutting, and cannot meet the requirements of existing aircraft for rubber bushing compositions. Summary of the invention

[0006] In view of the above analysis, the present invention aims to provide a method for preparing a rubber composition and a bushing for an aircraft, so as to solve the problem that the rubber composition prepared by the existing method has low tear strength and is not resistant to cutting.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing a rubber bushing composition, comprising the following steps:

[0009] Step 1: Soften the rubber, add reinforcing filler, antioxidant, vulcanization activator, silane coupling agent, phenolic resin, high styrene resin in proportion, mix and discharge the rubber to obtain a mixture;

[0010] Step 2: The mixture obtained in step 1 is allowed to stand, and a vulcanizing agent, a vulcanization accelerator, and a formaldehyde donor are added and mixed to obtain a mixed rubber;

[0011] Step 3: vulcanizing and crosslinking the mixed rubber obtained in step 2 to obtain a rubber bushing composition;

[0012] In step 3, the vulcanization temperature is 135-170° C., and the vulcanization time is 5-100 min.

[0013] Optionally, in step 1, the debinding temperature is 145-155°C.

[0014] Optionally, in step 2, the mixing time is 2-8 minutes.

[0015] Optionally, in step 2, the temperature of the mixture is controlled to be no higher than 110° C. during the mixing process.

[0016] Optionally, in step 2, the parking time is greater than 4 hours.

[0017] Optionally, in step 2, mixing is carried out at a low speed of 15-30 r / min.

[0018] Optionally, in step 3, vulcanization and cross-linking are carried out in a flat vulcanizer.

[0019] Optionally, in step 1, the softening temperature is 30-105°C.

[0020] Optionally, in step 1, the mixing time is 4-10 minutes.

[0021] Optionally, in step 1, the reinforcing filler includes white carbon black, and the usage ratio of the silane coupling agent to the white carbon black is (3-20):100.

[0022] In a second aspect, the present invention further provides a rubber composition prepared by the above-mentioned preparation method.

[0023] The raw materials for preparing the rubber composition include, by mass: 100 parts of rubber, 40-100 parts of reinforcing filler, 1.5-5 parts of antioxidant, 1-8 parts of vulcanizing agent, 0.2-3 parts of vulcanization accelerator, 2-10 parts of vulcanization activator, 0.3-5 parts of silane coupling agent, 0-20 parts of phenolic resin, 0-4 parts of formaldehyde donor, and 0-20 parts of high styrene resin.

[0024] Optionally, the phenolic resin is used in an amount of 3-20 parts, and the formaldehyde donor is used in an amount of 0.3-4 parts.

[0025] Optionally, the reinforcing filler further includes rubber carbon black, and the usage ratio of the rubber carbon black to the white carbon black is (2.7-10.7):1.

[0026] Optionally, the specific surface area of ​​the white carbon black is 75-230m 2 / g.

[0027] Optionally, the high styrene resin is used in an amount of 3-20 parts.

[0028] Optionally, the vulcanization accelerator includes one or a combination of thiazoles, thiurams, sulfenamides, dithiocarbamates, and sulfonates.

[0029] Optionally, the silane coupling agent includes bis-[γ-(triethoxysilyl)propyl]tetrasulfide and / or bis-[γ-(triethoxysilyl)propyl]disulfide.

[0030] Optionally, the vulcanization activator comprises zinc oxide and / or stearic acid.

[0031] Optionally, the antioxidant includes amines and / or phenols.

[0032] In a third aspect, the present invention further provides a bushing for aircraft, wherein the material of the bushing for aircraft is the rubber composition mentioned above or the rubber composition prepared by the above preparation method.

[0033] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0034] (1) The present invention optimizes the preparation process and controls the vulcanization temperature and vulcanization time, so that the prepared rubber composition has high tear strength (111.80-135.24 KN / m) and excellent dynamic properties (Tanδ (25°C) is 0.302-0.324).

[0035] (2) The present invention controls the temperature of rubber removal so that the prepared rubber composition has high mechanical properties and a tear elongation of 450%-496%.

[0036] (3) The rubber composition prepared by the preparation method of the present invention has excellent comprehensive performance, can meet the performance requirements of the bushing in the aircraft, and can be used as the bushing for the aircraft.

[0037] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can be obvious from the description or understood by practicing the present invention. DETAILED DESCRIPTION

[0038] In a first aspect, the present invention provides a method for preparing a rubber bushing composition, comprising the following steps:

[0039] Step 1: Soften the rubber, add reinforcing filler, antioxidant, vulcanization activator, silane coupling agent, phenolic resin, high styrene resin in proportion, mix (first mixing), and remove the rubber to obtain a mixture;

[0040] Step 2: The mixture obtained in step 1 is allowed to stand, and a vulcanizing agent, a vulcanization accelerator, and a formaldehyde donor are added and mixed (second mixing) to obtain a mixed rubber;

[0041] Step 3: vulcanize and crosslink the rubber mixture obtained in step 2 to obtain a rubber bushing composition.

[0042] Specifically, in step 1, the reinforcing filler includes white carbon black, and the usage ratio of the silane coupling agent to the white carbon black is (3-20):100.

[0043] In step 1, softening is carried out in an internal mixer, and the softening temperature is 30-105° C., for example, 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 105° C., preferably 70-105° C. The softening time is 20-40s, for example, 20s, 25s, 30s, 35s, 40s.

[0044] In step 1, the mixing time is 4-10 minutes, for example, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes.

[0045] The debinding temperature is 145-155°C, for example, 145°C, 146°C, 147°C, 148°C, 149°C, 150°C, 151°C, 152°C, 153°C, 154°C, 155°C.

[0046] It should be noted that the debinding temperature has a great influence on the performance of the rubber bushing composition obtained, so the debinding temperature is strictly controlled to be 145-155°C in the present invention. If the debinding temperature is too low, it will lead to insufficient mixing of the components in the composition, such as local agglomeration of the components or uneven mixing between the components, which will affect the smooth progress of the reaction and lead to poor performance of the rubber bushing composition. If the debinding temperature is too high, due to the combined action of heat and oxygen, the rubber molecular chain will be broken too much, the molecular weight will be reduced, and the basic mechanical properties and service life of the finished product will be reduced.

[0047] In step 2, the parking time is greater than 4 hours, specifically 5-10 hours, for example, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours.

[0048] Specifically, in step 2, the mixing time is 2-8 minutes, for example, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, and 8 minutes. The mixing is carried out in an open mill. During the mixing process, the temperature of the mixture is controlled not to be higher than 110° C. If the temperature of the mixture is higher than 110° C., on the one hand, the mixture will become sticky, causing process problems such as sticking to the roller and difficulty in mixing; on the other hand, it will significantly accelerate the reaction of active substances such as accelerators and sulfur, resulting in a shortened vulcanization induction period and even scorching.

[0049] In addition, in step 2, mixing is performed at a low speed, specifically, the speed is 15-30 r / min, for example, 15 r / min, 20 r / min, 25 r / min, 30 r / min.

[0050] Specifically, in step 3, vulcanization crosslinking is carried out in a flat vulcanizer, and the vulcanization temperature is 135-170°C, for example, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C. The vulcanization time is 5-100min, for example, 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 60min, 70min, 80min, 90min, 100min, preferably 15-25min. The vulcanization pressure is 8-15MPa, for example, 8MPa, 9MPa, 10MPa, 11MPa, 12MPa, 13MPa, 14MPa, 15MPa.

[0051] It should be noted that the vulcanization temperature and vulcanization time have a great influence on the performance of the rubber bushing composition obtained. Therefore, the present invention strictly controls the vulcanization temperature to 135-170°C and the vulcanization time to 5-100 minutes to ensure that the various properties of the composition meet the requirements. If the vulcanization temperature is too low and the vulcanization time is too short, it will affect the degree of vulcanization reaction, resulting in insufficient vulcanization of the rubber bushing composition, the product cannot achieve the best performance, and even becomes sticky and cannot be used normally. If the vulcanization temperature is too high and the vulcanization time is too long, on the one hand, the free flow time of the composition in the mold is reduced, and it cannot flow fully, causing accumulation or material shortage, and defects; on the other hand, the composition will be over-sulfurized, causing the product to be brittle and the actual service life to be reduced.

[0052] In the second aspect, the present invention also provides a rubber bushing composition for aircraft, which is prepared by the above-mentioned preparation method. The preparation raw materials include, by mass: 100 parts of rubber, 40-100 parts of reinforcing filler, 1.5-5 parts of antioxidant, 1-8 parts of vulcanizing agent, 0.2-3 parts of vulcanization accelerator, 2-10 parts of vulcanization activator, 0.3-5 parts of silane coupling agent, 0-20 parts of phenolic resin, 0-4 parts of formaldehyde donor, and 0-20 parts of high styrene resin.

[0053] Specifically, the rubber is one or more of natural rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber and ethylene-propylene-diene rubber.

[0054] The reinforcing filler includes white carbon black, and the amount of white carbon black is 3-20 parts, for example, 3 parts, 5 parts, 7 parts, 8 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, preferably 3-10 parts.

[0055] The reinforcing filler also includes rubber carbon black, and the usage ratio of rubber carbon black to white carbon black is (2.7-10.7):1, for example, 2.7:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 10.7:1.

[0056] The CTAB specific surface area of ​​carbon black for rubber is 20-160m 2 / g, for example, 20m 2 / g, 40m 2 / g, 60m 2 / g, 80m 2 / g, 90m 2 / g、100m 2 / g, 110m 2 / g, 120m 2 / g, 130m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g. Preferably 90-130m 2 / g.

[0057] The DBPA oil absorption value of rubber carbon black is 30-160m 2 / g, for example, 30m 2 / g, 40m 2 / g, 60m 2 / g, 80m 2 / g, 90m 2 / g、100m 2 / g, 110m 2 / g, 120m 2 / g, 130m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g. Preferably 100-130m 2 / g.

[0058] The BET specific surface area of ​​white carbon black is 75-230m 2 / g. For example, 75m 2 / g, 90m 2 / g、100m 2 / g, 120m 2 / g, 140m 2 / g, 160m 2 / g, 180m 2 / g, 200m 2 / g, 220m 2 / g, 230m 2 / g. Preferably 120-180m 2 / g.

[0059] It should be noted that the addition of rubber carbon black can, on the one hand, have a hardening effect; on the other hand, its high specific surface area and low structure are conducive to improving the material's resistance to cutting and breaking. However, adding too much will lead to reduced tear strength of the product and colorful surface of the product. Therefore, the present invention controls the amount of rubber carbon black to be 30-90 parts, preferably 50-70 parts.

[0060] The antioxidant may be selected from one or a combination of amines and phenols. Preferably, it is a combination of one or two of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline polymer. Exemplarily, the amount of the antioxidant is 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts.

[0061] The main component of the vulcanizing agent is sulfur, preferably insoluble sulfur. Exemplarily, the amount of the vulcanizing agent is 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts.

[0062] The vulcanization accelerator includes one or more of thiazoles, thiurams, sulfenamides, dithiocarbamates, and sulfonates. Preferably, N-cyclohexyl-2-benzothiazole sulfenamide and tetrabenzylthiuram disulfide are used. Exemplarily, the amount of the vulcanization accelerator is 0.2 parts, 0.4 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.3 parts, 2.5 parts, 2.8 parts, and 3 parts.

[0063] The dosage of the vulcanization activator is 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, and 10 parts. Specifically, the vulcanization activator is a combination of zinc oxide and stearic acid, wherein the dosage of zinc oxide is 1.5-8 parts, and the dosage of stearic acid is 1-3 parts.

[0064] The silane coupling agent is one or more of bis-[γ-(triethoxysilyl)propyl]tetrasulfide and bis-[γ-(triethoxysilyl)propyl]disulfide. Exemplarily, the amount of the silane coupling agent is 0.3 parts, 0.5 parts, 0.8 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts.

[0065] The usage ratio of silane coupling agent and white carbon black is: silane coupling agent / white carbon black=(3-20):100.

[0066] It should be noted that, as mentioned above, from the perspective of improving the hardness of the product, the more carbon black is added to the rubber, the better. However, if the amount is too much, the tear strength of the product will be reduced and the surface of the product will be colorful. The present invention controls the ratio of silane coupling agent and white carbon black to (3-20):100, so that white carbon black and silane coupling agent react fully and completely, avoiding excessive residue of one of the two in the system, thereby ensuring both the performance of the product and the appearance of the product (the surface is not colorful). If there is too much silane coupling agent, a large amount of small molecules will remain, causing the basic performance of the material to decline, product defects and shortened service life; if there is too little silane coupling agent, the interaction between the polymer chain and white carbon black will be weakened, reducing the dispersibility of white carbon black, causing problems such as decreased dynamic performance and white carbon black agglomeration defects.

[0067] It should be noted that the dosage ratio of the formaldehyde donor and the phenolic resin of the present invention is (8-20):100, for example, 8:100, 10:100, 12:100, 14:100, 16:100, 18:100, 20:100. If the dosage of the formaldehyde donor is too much, on the one hand, excessive small molecules will remain, causing problems such as decreased physical properties and bubbles in the product. On the other hand, after the excessive formaldehyde donor is decomposed, gas emissions will be generated, unnecessary post-processing steps will be added, and environmental pollution will be caused. If the dosage of the phenolic resin is too much, the hysteresis loss of the rubber composition will increase, the dynamic performance will deteriorate, and the hardness will decrease. Therefore, the present invention controls the dosage ratio of the formaldehyde donor and the phenolic resin to (8-20):100, which can not only ensure that the rubber composition has good dynamic properties, but also save costs and reduce environmental pollution.

[0068] Specifically, the phenolic resin is a reactive phenolic resin, preferably a combination of one or more of tall oil modified phenol formaldehyde resin and cashew nut oil modified phenol formaldehyde resin. Exemplarily, the amount of the phenolic resin is 3 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts.

[0069] The formaldehyde donor is one or a combination of hexamethylenetetramine and hexamethoxymethylmelamine. Exemplarily, the amount of the formaldehyde donor is 0.3 parts, 0.5 parts, 0.8 parts, 1 part, 3 parts, or 4 parts.

[0070] The high styrene resin is a styrene-butadiene polymer, wherein the combined styrene content is 60%-90%. Exemplarily, the amount of the high styrene resin is 3 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts.

[0071] It should be noted that the components in the composition of the present invention do not work in isolation, but work synergistically with each other to achieve the effect of 1+1>2, so that the composition has excellent comprehensive performance. Therefore, it cannot be simply assumed that the composition has or does not have the corresponding effect by adding or deleting a certain component, but the components should be viewed as a whole.

[0072] Examples 1-5

[0073] The advantages of precise control of the composition and process parameters of the rubber bushing composition of the present invention are demonstrated below with specific examples and comparative examples.

[0074] In the embodiment of the present invention, the natural rubber is selected to be No. 20 standard rubber TSR20.

[0075] The carbon black for rubber is N220 produced by Cabot, and the white carbon black is ZEODENT165 produced by Evonik Chemicals.

[0076] The antioxidants used were 6PPD from Sinopec and TMQ from Zhejiang Huangyan Zhedong Rubber Additives Co., Ltd.

[0077] The vulcanizing agent selected was insoluble sulfur HDOT20 (effective content 80%) produced by Yanggu Huatai.

[0078] The vulcanization accelerator used is NS produced by Shangshun Chemical.

[0079] Other materials not specified are commercially available conventional products.

[0080] Examples 1-5 of the present invention provide a rubber bushing composition for aircraft. The chemical compositions of the rubber bushing compositions for aircraft in Examples 1-5 are shown in Table 1.

[0081] The aircraft rubber bushing compositions of Examples 1-5 were prepared by the following preparation method: softening rubber, adding part of raw materials, first mixing, rubber removal, parking, adding other raw materials, second mixing, and vulcanization. Softening: softening temperature is 90° C., softening time is 30 s.

[0082] First mixing: mixing time is 5 minutes. The glue removal temperature is 140℃ and the parking time is 7 hours. Second mixing: mixing temperature is not higher than 100℃ and mixing time is 5 minutes. Vulcanization: vulcanization temperature is 175℃, vulcanization time is 5min, and vulcanization pressure is 10MPa.

[0083] The main performance test results of the produced rubber bushing composition are shown in Table 3.

[0084] Table 1 Chemical composition (parts by mass)

[0085]

[0086] Embodiments 8-12 of the present invention provide a method for preparing a rubber bushing composition for an aircraft. The composition of Embodiments 8-12 is the same as that of Embodiment 2. The specific process parameters are shown in Table 2. The main performance test results of the produced rubber bushing composition are shown in Table 5.

[0087] Table 2 Production process parameters

[0088]

[0089] Table 3 Main performance test results

[0090]

[0091] MH-ML (dN*m): The difference between the maximum torque and the minimum torque during the vulcanization characteristics test.

[0092] The tear strength test of the present invention is as follows: refer to GB / T 528-2008, the experimental method is method B, right-angled specimen, no cut. Other test methods are carried out in accordance with relevant national standards.

[0093] The inventor has conducted a large number of experimental studies during the research process, and now uses some solutions with poor performance as comparative examples.

[0094] Comparative Example 1

[0095] The rubber in this comparative example is polyurethane rubber used in the existing bushing.

[0096] Example 6

[0097] This embodiment is basically the same as embodiment 8, except that the ratio of the silane coupling agent to the white carbon black is 2:100, wherein the silane coupling agent is 0.16 parts and the white carbon black is 8 parts.

[0098] Example 7

[0099] This comparative example is basically the same as Example 8, except that the usage ratio of the formaldehyde donor and the phenolic resin is 4:100, wherein the formaldehyde donor is 0.48 parts and the phenolic resin is 12 parts.

[0100] The main performance test results of the comparative rubber bushing composition are shown in Table 4. The test method and test conditions used in the comparative example are the same as those of the embodiment of the present invention.

[0101] Table 4 Main performance test results of comparative rubber bushing compositions

[0102]

[0103] Table 5 Main performance test results

[0104]

[0105] It can be seen from the data of Examples 1-5 and Comparative Example 1 in Table 3 that the specific gravity of the rubber bushing composition of the present invention is 1.169-1.186, which is significantly lower than that of the existing polyurethane rubber, making a certain contribution to the lightweight of the product.

[0106] It can be seen from the hardness data of Examples 1-5 and Comparative Example 1 in Table 3 that the hardness of the rubber bushing composition of the present invention is 89-91, which has a hardness equivalent to that of polyurethane and can completely replace it under the same working conditions.

[0107] It can also be seen from Table 3 that compared with Comparative Example 1, the rubber bushing composition of the present invention has a higher elongation at break (447%-494%), which is 1.84-2.03 times that of polyurethane (Comparative Example 1), and can keep the product from being damaged under large deformation. The tear strength of the rubber bushing composition of the present invention is 100.30-133.11 KN / m, which is about 3 times that of Comparative Example 1, and the tear resistance is significantly improved. The cutting loss of Comparative Example 1 is 35.6%, and the cutting loss of the rubber bushing composition of the present invention is only 19.7%-30.7%, and the anti-blocking performance is significantly improved. In addition, the Tanδ (25℃) of Comparative Example 1 is 0.621, and the Tanδ (25℃) of the rubber bushing composition of the present invention is only 0.294-0.379. Compared with Comparative Example 1, the dynamic performance of the rubber bushing composition of the present invention is better. Therefore, the rubber bushing composition of the present invention is a bushing for aircraft with excellent comprehensive performance.

[0108] In addition, the inventors conducted a large number of experimental studies during the research process. For the rubber and cross-linking system described in the article, a vulcanization temperature that is too high (>180°C) will cause the chemical reaction rate to be too fast and the operation time to be too short, making it difficult to implement in practice. In addition, the thermal conductivity of general rubber is relatively small. High temperature will cause the surface temperature and internal temperature of rubber products to differ too much, causing the internal and external chemical reaction rates to be significantly different, making it difficult to obtain products of uniform quality. Correspondingly, a vulcanization temperature that is too low (<135°C) will cause the chemical reaction rate to be too slow or unable to react normally at all, affecting production. None of the above can produce an aircraft bushing with excellent comprehensive performance.

[0109] Furthermore, it can be seen from the data of Examples 6 and 7 in Table 4 that, when the method for preparing the rubber composition of the present invention is used, when the ratio of the silane coupling agent to white carbon black is not within the range of (3-20):100 or the ratio of the formaldehyde donor to the phenolic resin is not within the range of (8-20):100, the comprehensive performance of the rubber bushing composition for aircraft can be improved to a certain extent.

[0110] It can be seen from the data of Examples 8-12 in Table 5 that the rubber bushing composition prepared by the preparation method of the present invention has a specific gravity of approximately 1.186, a hardness of 89-93, a tensile strength of 21.0-24.2 MPa, an elongation at break of 450%-496%, a tear strength of 111.80-135.24 KN / m, a cutting loss of 18.5%-25.1%, and a Tanδ (25°C) of 0.302-0.324. It is a rubber bushing composition with excellent comprehensive performance and can meet the performance requirements of bushings in aircraft.

[0111] By comparing the data in Table 5 and Table 3, it can be seen that in the preparation method of the present invention, by strictly controlling the debonding temperature, vulcanization temperature and vulcanization time, the tear strength (above 111.80 KN / m), dynamic properties (Tanδ (25°C) is below 0.324) and mechanical properties (tear elongation at break is above 450%) of the rubber bushing composition can be further improved.

[0112] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a rubber composition, characterized in that: The following steps are involved: Step 1: Soften the rubber, add reinforcing filler, antioxidant, vulcanization activator, silane coupling agent, phenolic resin, high styrene resin in proportion, mix and discharge the rubber to obtain a mixture; Step 2: The mixture obtained in step 1 is allowed to stand, and a vulcanizing agent, a vulcanization accelerator, and a formaldehyde donor are added and mixed to obtain a mixed rubber; Step 3: vulcanizing and crosslinking the mixed rubber obtained in step 2 to obtain a rubber bushing composition; In step 3, the vulcanization temperature is 135-170° C., and the vulcanization time is 5-100 min.

2. The preparation method according to claim 1, characterized in that: In step 1, the debinding temperature is 145-155°C.

3. The preparation method according to claim 1 or 2, characterized in that: In step 2, the mixing time is 2-8 minutes.

4. The preparation method according to claim 3, characterized in that: In step 2, the temperature of the mixture is controlled not to be higher than 110° C. during the mixing process.

5. The preparation method according to claim 1, characterized in that: In step 2, the parking time is greater than 4 hours.

6. The preparation method according to claim 1, characterized in that: In step 2, mixing is carried out at a low speed of 15-30 r / min.

7. The preparation method according to claim 1, characterized in that: In step 3, vulcanization and cross-linking are carried out in a flat vulcanizing press.

8. The preparation method according to claim 1, characterized in that: In step 1, the softening temperature is 30-105°C.

9. A rubber composition, characterized in that: The preparation method is described in any one of claims 1 to 8.

10. A bushing for an aircraft, characterized in that: The material of the aircraft bushing is the rubber composition according to claim 9.

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