Thermally conductive rubber composition and its use, vulcanizates and methods for their production and use

Abstract

The application relates to the rubber field and discloses a heat-conducting rubber composition and application thereof, vulcanized rubber and a preparation method and application thereof, the heat-conducting rubber composition comprising a main rubber, graphene, a coupling agent, a carbon-based reinforcing agent, a uniformizing agent, a vulcanizing agent, a vulcanization activator, a plasticizer and a vulcanization accelerator, the graphene being layered graphene; the carbon-based reinforcing agent being carbon black; and the uniformizing agent being at least one selected from fatty acids, aliphatic hydrocarbon waxes, aromatic hydrocarbon waxes, fatty acid amines, zinc salts of fatty acids and fatty acid esters. The vulcanized rubber prepared from the heat-conducting rubber composition has good processing performance, mechanical properties and air tightness, stable service life and high heat-conducting efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber, in particular, a heat-conducting rubber composition and its application, a method for preparing vulcanized rubber, and the application of the vulcanized rubber prepared by the method in preparing vulcanized capsules. BACKGROUND

[0002] Vulcanized capsules are internal supporting molds used in the shaping of tire vulcanization, and are one of the most complex movable parts in the vulcanization machine for producing tires. The use environment and conditions are extremely harsh, and the vulcanized capsules need to withstand constant exchange of hot water, steam, nitrogen, high temperature and high pressure, multiple pulses and long-term repeated stretching. Therefore, the service life of the vulcanized capsules has always been the most concerned problem of tire enterprises.

[0003] With the continuous improvement of the quality requirements for rubber products, the heat resistance of the rubber material for the vulcanized capsules is becoming higher and higher. However, the heat resistance of sulfur-crosslinked rubber is limited, which requires the use of rubber materials with lower saturation. For these low-saturation rubber materials that do not use sulfur crosslinking, corresponding new chemicals (such as uniformizing agents) must be used to adapt to this new crosslinking system and processing process.

[0004] Influence of Graphene Amount on Properties of Butyl Rubber (China Rubber, No. 12, 2018) reports the influence of the amount of graphene on the properties of butyl rubber under the action of a coupling agent: with the increase of the amount of graphene, the maximum torque M H , the minimum torque M L , and the apparent crosslinking density of the vulcanized rubber gradually increase, and the scorch time and the optimum curing time show a trend of shortening. Compared with butyl vulcanized rubber without adding graphene, the tensile strength, tear strength, modulus, and Shore A hardness of the composite material are significantly improved. Graphene has a good reinforcing effect on butyl rubber, and graphene can also significantly improve the thermal conductivity of the composite material. In this prior art, the base rubber, graphene, carbon black, and coupling agent are added at the same time to prepare the mixed rubber. Since the content of carbon black is much higher than that of graphene, the contact opportunity of the coupling agent with graphene is less than that of carbon black. Therefore, the dispersion effect of the coupling agent on graphene is not fully exerted, and the reinforcing effect of graphene on rubber and the improvement of the thermal conductivity are much better than those of carbon black. Therefore, this processing method limits the role of graphene.

[0005] The tire vulcanization capsule requires high temperature resistance, high strength, high elongation, and low tensile set (elongation recovery). The long service life of the vulcanization capsule can improve production efficiency, ensure tire quality and control lower manufacturing costs. In some existing technologies for preparing rubber vulcanization capsules, there are still two problems: low heat conduction efficiency and unstable service life. Low heat conduction efficiency leads to difficulty in heat conduction during use, low aging resistance and crack growth resistance of the vulcanization capsule, resulting in low average service life of the vulcanization capsule, which not only increases the production cost, but also directly affects the product quality and production efficiency.

[0006] Therefore, it is necessary to provide a new method for preparing a rubber composition and a vulcanization capsule which can solve the above problems. SUMMARY

[0007] The purpose of the present application is to solve the problems of low heat conduction efficiency and unstable service life of the vulcanization capsule provided by the prior art, and to provide a heat-conducting rubber composition, a vulcanized rubber with good mechanical properties and excellent heat-conducting properties, and a preparation method thereof.

[0008] To achieve the above-mentioned purpose, the first aspect of the present application provides a heat-conducting rubber composition, which contains two or more of the following components mixed and stored or stored independently:

[0009] The main rubber, graphene, coupling agent, carbon-based reinforcing agent, uniformizing agent, vulcanizing agent, vulcanizing activator, plasticizer and vulcanization accelerator,

[0010] The main rubber is butyl rubber with a saturation higher than 98.3%; the graphene is layered graphene; the carbon-based reinforcing agent is carbon black; the uniformizing agent is selected from at least one of fatty acid, aliphatic hydrocarbon wax, aromatic hydrocarbon wax, fatty acid amine, zinc salt of fatty acid and fatty acid ester;

[0011] The content of the graphene is 1-15 parts by weight, the content of the coupling agent is 0.1-1 parts by weight, the content of the carbon-based reinforcing agent is 30-60 parts by weight, the content of the uniformizing agent is 1-6 parts by weight, the content of the vulcanizing agent is 3-10 parts by weight, the content of the vulcanizing activator is 2-11 parts by weight, the content of the plasticizer is 3-8 parts by weight, and the content of the vulcanization accelerator is 2-8 parts by weight, relative to 100 parts by weight of the main rubber.

[0012] The second aspect of the present application provides a method for preparing a vulcanized rubber, which comprises mixing the components in the heat-conducting rubber composition of the first aspect described above to form a rubber compound, and vulcanizing the rubber compound.

[0013] The third aspect of the present application provides a vulcanized rubber prepared by the above-mentioned method.

[0014] The fourth aspect of the present application provides the use of the above-mentioned vulcanized rubber in the preparation of a vulcanized capsule.

[0015] The fifth aspect of the present application provides the use of the above-mentioned heat-conducting rubber composition in the preparation of a vulcanized capsule rubber.

[0016] The present application adopts butyl rubber as the main rubber, blends a specific amount of graphene, and optimizes the use amount of a coupling agent, a carbon-based reinforcing agent, a uniformizing agent, a vulcanizing agent, a vulcanization activator, a plasticizer, and a vulcanization accelerator, etc., to provide a heat-conducting rubber composition with good processing performance, mechanical properties, and air tightness, stable service life, and high heat-conducting efficiency.

[0017] According to the performance characteristics of the material, the heat-conducting rubber composition of the present application is particularly suitable for producing a vulcanized capsule. DETAILED DESCRIPTION

[0018] The endpoints of the ranges and any values claimed herein are not to be understood as being limited to the exact values recited as implicitly disclosed by the above description. Ranges can be expressed as from one value and / or to another value. When such a range is expressed, the intention is to include all values and / or subsets between and including the first and second values. Values included in a range are inclusive of the first and second values.

[0019] As previously described, the first aspect of the present application provides a heat-conducting rubber composition containing the following components mixed and stored together or stored independently:

[0020] The main rubber, the graphene, the coupling agent, the carbon-based reinforcing agent, the uniformizing agent, the vulcanizing agent, the vulcanization activator, the plasticizer, and the vulcanization accelerator,

[0021] The main rubber is butyl rubber with a saturation higher than 98.3%; the graphene is layered graphene; the carbon-based reinforcing agent is carbon black; and the uniformizing agent is at least one selected from a fatty acid, a fatty hydrocarbon wax, an aromatic hydrocarbon wax, a fatty acid amine, a zinc salt of a fatty acid, and a fatty acid ester;

[0022] The content of the graphene is 1-15 parts by weight, the content of the coupling agent is 0.1-1 parts by weight, the content of the carbon-based reinforcing agent is 30-60 parts by weight, the content of the uniformizing agent is 1-6 parts by weight, the content of the vulcanizing agent is 3-10 parts by weight, the content of the vulcanization activator is 2-11 parts by weight, the content of the plasticizer is 3-8 parts by weight, and the content of the vulcanization accelerator is 2-8 parts by weight, relative to 100 parts by weight of the main rubber.

[0023] The inventors have found that the composition of the present application can improve the heat conduction efficiency of vulcanized rubber by using specific components in specific amounts, so that the vulcanized rubber prepared from the composition has good heat conduction performance.

[0024] In the present application, the unsaturation degree is expressed by the content of double bonds, and the relationship between the two is content of double bonds + unsaturation degree = 100%.

[0025] Preferably, the content of the graphene is 5-9 parts by weight, the content of the coupling agent is 0.2-0.6 parts by weight, the content of the carbon-based reinforcing agent is 30-60 parts by weight, the content of the uniformizing agent is 2-5 parts by weight, the content of the vulcanizing agent is 5-8 parts by weight, the content of the vulcanization activator is 5-8 parts by weight, the content of the plasticizer is 5-6 parts by weight, and the content of the vulcanization accelerator is 5-7 parts by weight, relative to 100 parts by weight of the main rubber.

[0026] Preferably, in the main rubber, the Mooney viscosity ML(1+8) 125℃ of the butyl rubber is 45-55, and the content of double bonds is less than 1.7% by weight.

[0027] Preferably, the coupling agent is a silane coupling agent having the structure of R-(SiX1X2X3) m ; wherein,

[0028] R is an aliphatic hydrocarbon group containing at least one group selected from the group consisting of a vinyl group, an epoxy group, an amino group, a methacryloxy group, a mercapto group, a 3-propionylthio-1-propyl group, and a polysulfide bond, or an aromatic hydrocarbon group containing at least one group selected from the group consisting of a vinyl group, an epoxy group, an amino group, a methacryloxy group, a mercapto group, a 3-propionylthio-1-propyl group, and a polysulfide bond; X1, X2, and X3 are each independently a hydrolyzable functional group; and m is 1 or 2.

[0029] Further preferably, in the structure of R-(SiX1X2X3) m , X1, X2, and X3 are each independently a methoxy group, an ethoxy group, or a chlorine.

[0030] More preferably, the silane coupling agent is selected from at least one of γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and bis-[γ-(triethoxysil)propyl]tetrasulfide.

[0031] Preferably, the carbon-based reinforcing agent includes carbon black I with a relatively large average particle size and carbon black II with a relatively small average particle size; the average particle size of the carbon black I is 30-40 nm, the specific surface area by CTAB method is 70-90 cm 2 / g, and the DPB absorption value is 3.0-3.5 cm 3 / g; the average particle size of the carbon black II is 26-30 nm, and the CTAB method specific surface area is 90-120 cm 2 / g, and the DPB absorption value is 1.02-1.13 cm 3 / g. The inventors found that in this preferred case, the vulcanized rubber prepared from the composition of the present application has better heat conduction performance.

[0032] Preferably, the content weight ratio of the carbon black I and the carbon black II is 1:0.2-0.8.

[0033] More preferably, the content weight ratio of the carbon black I and the carbon black II is 1:0.4-0.7. The inventors found that when the content weight ratio of the carbon black I and the carbon black II is 1:0.4-0.7, the vulcanized rubber prepared from the composition of the present application has higher heat conduction efficiency, so that the vulcanized rubber prepared from the composition has better heat conduction performance.

[0034] Preferably, the graphene is reduced graphene and / or oxidized graphene.

[0035] Preferably, the uniformizing agent is selected from at least one of the group consisting of a combination of aliphatic hydrocarbon wax and aromatic hydrocarbon wax, a fatty acid, a fatty acid amine, zinc stearate, pentaerythritol stearate.

[0036] Preferably, the vulcanizing agent is selected from at least one of the group consisting of resin-based vulcanizing agents.

[0037] Further preferably, the vulcanizing agent is selected from at least one of the group consisting of phenolic resin-based vulcanizing agents.

[0038] Preferably, the vulcanization activator is an inorganic activator and / or an organic activator; the inorganic activator is selected from at least one of the group consisting of indirect zinc oxide, direct zinc oxide and active zinc oxide, and the organic activator is selected from at least one of the group consisting of lauric acid, octanoic acid and stearic acid.

[0039] According to one preferred embodiment, the vulcanization activator is an inorganic activator and an organic activator, and the content of the organic activator is 0.2-1 parts by weight and the content of the inorganic activator is 2-5 parts by weight, based on 100 parts by weight of rubber.

[0040] Preferably, the plasticizer is selected from at least one of the group consisting of petroleum-based plasticizers, aliphatic oil-based plasticizers and synthetic plasticizers.

[0041] Further preferably, the petroleum-based plasticizer is selected from at least one of naphthenic oil, aromatic oil, paraffin wax, microcrystalline wax, polyethylene wax; the fatty oil-based plasticizer is selected from at least one of glycerol, castor oil, soybean oil, oleic acid; the synthetic plasticizer is selected from at least one of ethylene glycol, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl adipate and epoxidized soybean oil.

[0042] Preferably, the vulcanization accelerator is selected from at least one of halogen-containing vulcanization accelerators.

[0043] Further preferably, the vulcanization accelerator is selected from at least one of chloroprene rubber and brominated butyl rubber.

[0044] As described before, the second aspect of the present application provides a method for preparing a vulcanized rubber, the method comprising: mixing the components in the heat-conducting rubber composition of the aforementioned first aspect to form a rubber compound, and subjecting the rubber compound to a vulcanization treatment.

[0045] The mixing method is not particularly limited in the present application, as long as the components in the heat-conducting rubber composition can be uniformly mixed. For example, the components in the heat-conducting rubber composition can be mixed simultaneously, or several components can be mixed first, and then the remaining components can be added and mixed.

[0046] However, in order to obtain better heat-conducting performance and better mechanical properties, according to a preferred embodiment, the step of mixing the components in the heat-conducting rubber composition of the aforementioned first aspect comprises:

[0047] (1) masterbatching the base rubber, graphene, coupling agent and homogenizing agent to obtain a master compound;

[0048] (2) first mixing the master compound with the carbon-based reinforcing agent, vulcanization activator, plasticizer and vulcanization accelerator with the master compound to obtain a first mixed compound;

[0049] (3) second mixing the vulcanizing agent with the first mixed compound to obtain the rubber compound.

[0050] The inventors have found that, by the method provided by the preferred embodiment of the present application, the dispersion performance of the reinforcing agent can be better, and the prepared rubber compound has good processing performance.

[0051] Preferably, the masterbatching, first mixing and second mixing are each independently carried out in an open mill and / or an internal mixer.

[0052] Preferably, in step (1), the mixing conditions of the masterbatch at least satisfy: temperature is 70-140℃, time is 3-6min. More preferably, the mixing conditions of the masterbatch at least satisfy: temperature is 90-120℃, time is 4-5min.

[0053] Preferably, in step (2), the first mixing conditions at least satisfy: mixing temperature is 90-170℃, mixing time is 3-10min. More preferably, the first mixing conditions at least satisfy: mixing temperature is 145-150℃, mixing time is 3-5min.

[0054] Preferably, in step (3), the second mixing conditions at least satisfy: mixing temperature is not higher than 150℃, mixing time is 1-7min. More preferably, the second mixing conditions at least satisfy: mixing temperature is 90-120℃, mixing time is 1-3min.

[0055] Preferably, the curing conditions at least satisfy: curing temperature is 140-210℃, curing time is 5-50min, curing pressure is 3-20MPa.

[0056] In the absence of special instructions, the pressure in the present application is all gauge pressure (reading on the pressure gauge of the hydraulic system of the curing machine).

[0057] As mentioned above, the third aspect of the present application provides a vulcanized rubber prepared by the above-mentioned method.

[0058] As mentioned above, the fourth aspect of the present application provides the use of the above-mentioned vulcanized rubber in the preparation of a vulcanized capsule.

[0059] As mentioned above, the fifth aspect of the present application provides the use of the above-mentioned heat-conducting rubber composition in the preparation of a vulcanized capsule rubber.

[0060] The present application will be described in detail below by way of examples. In the following examples, in the absence of special instructions, the raw materials used are all commercially available.

[0061] The equipment involved in the following examples is shown in Table 1.

[0062] Table 1

[0063] Serial number Equipment name Model Manufacturer 1 Internal mixer BR1600 Farrel Co., Ltd. 2 Open mill XK-160 Qingdao Xincheng Yiming Machinery Co., Ltd. 3 Flat vulcanizing machine XLB-D400*400*2 Shanghai First Rubber Machinery Factory 4 Universal tensile testing machine GT-AT-3000 Taiwan Gotech 5 Mooney viscometer SMV-300 Taiwan Gotech 6 Curemeter GT-M2000A Taiwan Gotech 7 Rubber processing analyzer RPA2000 Alpha Technologies Co., Ltd. 8 Aging tester GT-7017-EL1 Taiwan Gotech 9 Thermal conductivity tester TC3000 Xi'an Xiayi Electronic Technology Co., Ltd. 10 Differential pressure gas permeation apparatus TM(PERMETM)VAC-V2 Jinan Languang Mechanical and Electrical Technology Co., Ltd.

[0064] The chemical reagents used in the examples are commercially available, and are as follows:

[0065] Butyl rubber I: brand 1451, Mooney viscosity ML(1+8)125℃ is 48, double bond content is 1.61%, purchased from China Petroleum Chemical Co., Ltd.

[0066] Butyl rubber II: brand 301, Mooney viscosity ML (1+8) 125°C of 62, double bond content of 1.45%, purchased from Arlanxeo.

[0067] Butyl rubber III: brand 268s, Mooney viscosity ML (1+8) 125°C of 51, double bond content of 1.70%, purchased from Arlanxeo.

[0068] Graphene: brand KNG-T181-2, purchased from Xiamen Kaina Graphene Technology Co., Ltd.

[0069] Coupling agent: γ-(methacryloyloxy) propyl trimethoxysilane (KH570), γ-aminopropyl triethoxysilane (KH550), bis-[γ-(triethoxysil) propyl] tetrasulfide (Si69), purchased from Beijing Inokai Chemical Reagent Co., Ltd.

[0070] Carbon black I: 1# carbon black, average particle size of 32 nm, specific surface area of 72 cm 2 / g by CTAB method, DPB absorption value of 3.5 cm 3 / g, purchased from Tianjin Heima Carbon Black Co., Ltd.

[0071] Carbon black I: 2# carbon black, average particle size of 39 nm, specific surface area of 89 cm 2 / g by CTAB method, DPB absorption value of 3.2 cm 3 / g, purchased from Tianjin Heima Carbon Black Co., Ltd.

[0072] Carbon black II: brand N330, average particle size of 28 nm, specific surface area of 105 cm 2 / g by CTAB method, DPB absorption value of 1.08 cm 3 / g, purchased from Tianjin Heima Carbon Black Co., Ltd.

[0073] Uniformizing agent

[0074] Rhein Chemie-25: provides fatty acid, aliphatic hydrocarbon wax and aromatic hydrocarbon wax, purchased from Rhein Chemie.

[0075] Rhein Chemie-34: provides fatty acid amine, purchased from Rhein Chemie.

[0076] Rhein Chemie-54: provides pentaerythritol stearate, purchased from Rhein Chemie.

[0077] Rhein Chemie-42: provides fatty acid, fatty alcohol, fatty acid ester, purchased from Rhein Chemie.

[0078] Uniformizing agent 40MSF: provides aliphatic hydrocarbon wax and aromatic hydrocarbon wax, purchased from SCA, USA.

[0079] Homogenizing agent 40MS: providing aliphatic hydrocarbon wax, purchased from SCA Company, USA.

[0080] Brominated phenolic resin: grade SP-1055, purchased from Shennahaichem (Shanghai) Co., Ltd.

[0081] Zinc oxide: purchased from Beijing Inokai Chemical Reagent Co., Ltd.

[0082] Stearic acid: purchased from Beijing Inokai Chemical Reagent Co., Ltd.

[0083] Castor oil: purchased from Tianjin Guangfu Chemical Reagent Co., Ltd.

[0084] Microcrystalline wax: grade 80 microcrystalline wax, purchased from Beijing Inokai Chemical Reagent Co., Ltd.

[0085] Chlorobutyl rubber: grade CR1211, purchased from Shanxi Synthetic Rubber Group Co., Ltd.

[0086] Unless otherwise specified, each part by weight in the following examples represents 10 g.

[0087] Preparation Example 1: Preparation of vulcanized rubber

[0088] Masterbatch mixing:

[0089] The butyl rubber, graphene, coupling agent and homogenizing agent were added to the internal mixer, and the initial temperature of the internal mixer and the speed of the internal mixer were set. The masterbatch mixing was carried out to obtain the masterbatch.

[0090] First mixing:

[0091] The upper plunger of the internal mixer for the aforementioned masterbatch mixing was lifted, and the carbon-based reinforcing agent, vulcanization activator, plasticizer and vulcanization accelerator were mixed with the aforementioned masterbatch to obtain the first mixed rubber.

[0092] Second mixing:

[0093] The aforementioned first mixed rubber and vulcanizing agent were added to the internal mixer, and the initial temperature of the internal mixer and the speed of the internal mixer were set. The second mixing was carried out to obtain the mixed rubber.

[0094] The mixed rubber was passed through the roll mill 6 times with a roll gap of 0.8 mm, and then the roll gap was adjusted to 6 mm and passed through 4 times to obtain the open rubber.

[0095] The open rubber was vulcanized on a flat vulcanizing machine with a set temperature and pressure to obtain the vulcanized rubber, which was denoted as Z1. In addition, the necessary process conditions and other information in the present preparation example are listed in Tables 2 and 3.

[0096] The rest of the preparation examples used the same procedure as Preparation Example 1, except for the process conditions and component formulations, unless otherwise specified. The specific process conditions are shown in Table 2, and the specific component formulations are shown in Table 3.

[0097] Table 2

[0098]

[0099] Table 3

[0100]

[0101] Comparative Example 1

[0102] According to the preparation procedure of Preparation Example 4, except for the formulation, the final vulcanized rubber is denoted as D1, and the specific formulation is shown in Table 4.

[0103] Test Example: Test of Properties of the Rubber Compound and Vulcanized Rubber

[0104] (1) Compound Mooney Viscosity: The compound Mooney viscosity was tested by a Mooney viscometer according to the method specified in GB / T1232.1-2016, the test temperature was 125°C, the preheating time was 1 min, and the test time was 8 min, the test result was expressed as ML(1+8)125°C, and the obtained results are shown in Table 5.

[0105] (2) Compound Cure Characteristics: The compound cure characteristics were tested by a vulcanization tester according to the method specified in GBT 16584-1996, the oscillation angle was 1°, the frequency was 1.67 Hz, and the temperature was 200°C. The obtained results are shown in Table 6.

[0106] (3) Tensile Strength of Vulcanized Rubber: The tensile strength was tested by a universal tensile testing machine according to the method specified in GB / T528-1998, and the obtained results are shown in Table 7.

[0107] (4) Tear Strength of Vulcanized Rubber: The tear strength was tested according to the method specified in GB / T529-1999, and the obtained results are shown in Table 8.

[0108] (5) Aging Resistance of Vulcanized Rubber: The aging resistance was tested by an aging tester according to the method specified in GB / 3512-2001, the aging temperature was 180°C, and the obtained results are shown in Table 9.

[0109] The calculation method of the change in each property before and after aging is as follows:

[0110] The calculation method of the change in hardness is H = Xa - X0

[0111] Wherein:

[0112] H - Change in hardness

[0113] Xa— hardness measurement value after aging of the sample

[0114] X0— hardness measurement value before aging of the sample

[0115] Method for calculating the rate of change of other properties in addition to hardness: P = (Xa - X0) / X0 x 100%

[0116] Wherein:

[0117] P— rate of change of properties, %

[0118] Xa— performance measurement value after aging of the sample

[0119] X0— performance measurement value before aging of the sample

[0120] The average value of change is used to evaluate the aging resistance of a formula, and the calculation method is as follows:

[0121] Average value of change

[0122] P (average) = [P (average, tensile strength) + P (average, elongation at break) + P (average, 300% modulus) + P (average, 100% modulus) + P (average, permanent deformation) + P (average, tear strength)] / 6

[0123] Wherein the average value of the change rate of tensile strength and other properties at different aging times is calculated as follows:

[0124] P (average, tensile strength and other properties) = (|P10| + |P18| + |P24|) / 3

[0125] Wherein:

[0126] |P10|, |P18|, |P24| are the absolute values of the change rates of tensile strength and other properties after aging for 10h, 18h and 24h respectively

[0127] (6) Thermal conductivity of vulcanized rubber: The thermal conductivity of vulcanized rubber at room temperature was tested by a thermal conductivity tester according to the transient hot wire method specified in GB / T11205-2009. The results are shown in Table 10.

[0128] (7) Air tightness of vulcanized rubber: The air tightness was tested by a type pressure difference method gas permeation instrument according to the method specified in GB / T1038-2000. The results are shown in Table 11.

[0129] Table 5

[0130] Z1 Z2 Z3 Z4 Z5 Z6 D1 Mooney viscosity(ML(1+8)125℃) 65.0 64.7 58.8 51.5 53.8 58.1 56.5

[0131] Table 6

[0132] Curing characteristics Z1 Z2 Z3 Z4 Z5 Z6 D1 MH / dm·N 13.39 13.08 13.20 11.69 12.39 12.24 12.81 ML / dm·N 3.26 3.05 2.71 2.64 2.79 2.66 2.77 TS1 / min 0.73 0.75 0.79 0.97 0.93 0.83 0.99 TS2 / min 1.10 1.10 1.12 1.69 1.67 1.29 1.84 TC10 / min 0.70 0.75 0.79 0.91 0.9 0.82 0.95 TC50 / min 2.90 2.95 3.09 5.00 4.87 3.33 5.40 TC90 / min 17.82 17.98 21.55 26.82 26.7 15.40 31.40 MH-ML / dm·N 10.13 10.03 10.49 9.05 9.60 9.58 10.04

[0133] Table 7

[0134] Tensile strength Z1 Z2 Z3 Z4 Z5 Z6 D1 Shore A hardness 70 70 69 69 69 69 66 Tear elongation rate / % 683 637 554 624 600 611 603 Tensile strength / MPa 10.4 10.4 12.4 11.5 9.3 10.8 8.7 100%elongation stress / MPa 2.27 2.28 2.57 2.57 2.46 2.42 2.05 300%elongation stress / MPa 4.73 4.97 6.06 5.77 4.86 5.10 4.15 Permanent deformation / % 38 36 25 25 36 26 32

[0135] Table 8

[0136] Z1 Z2 Z3 Z4 Z5 Z6 D1 Tear strength / N / mm 38 39 38 35 37 37 38

[0137] Table 9

[0138]

[0139]

[0140] Table 10

[0141]

[0142] Table 11

[0143]

[0144] It can be seen from the results in the table that the rubber compound prepared by using the heat-conducting rubber composition has good processing performance, the vulcanized rubber prepared has good mechanical properties and air tightness, stable service life, and high heat-conducting efficiency.

[0145] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and belong to the protection scope of the present application.

Claims

1. A heat conductive rubber composition, characterized by, The composition contains the following components each independently stored or stored in mixture of two or more: a base rubber, graphene, a coupling agent, a carbon-based reinforcing agent, a uniformizing agent, a vulcanizing agent, a vulcanization activator, a plasticizer, and a vulcanization accelerator, The base rubber is a butyl rubber having a degree of saturation higher than 98.3%; the graphene is a layered graphene; the carbon-based reinforcing agent is carbon black; the uniformizing agent is at least one selected from the group consisting of a combination of aliphatic and aromatic hydrocarbon waxes, a fatty acid, a fatty acid amine, zinc stearate, and pentaerythritol stearate; In the base rubber, the butyl rubber has a Mooney viscosity ML(1+8) 125℃ of 45 to 65 and a double bond content of less than 1.7% by weight. The plasticizer is a combination of a petroleum-based plasticizer and a fatty oil-based plasticizer. The content of the graphene is 1 to 15 parts by weight, the content of the coupling agent is 0.1 to 1 part by weight, the content of the carbon-based reinforcing agent is 30 to 60 parts by weight, the content of the uniformizing agent is 1 to 6 parts by weight, the content of the vulcanizing agent is 3 to 10 parts by weight, the content of the vulcanization activator is 2 to 11 parts by weight, the content of the plasticizer is 3 to 8 parts by weight, and the content of the vulcanization accelerator is 2 to 8 parts by weight, with respect to 100 parts by weight of the base rubber.

2. The composition of claim 1, wherein, The content of the graphene is 5 to 9 parts by weight, the content of the coupling agent is 0.2 to 0.6 parts by weight, the content of the carbon-based reinforcing agent is 30 to 60 parts by weight, the content of the uniformizing agent is 2 to 5 parts by weight, the content of the vulcanizing agent is 5 to 8 parts by weight, the content of the vulcanization activator is 5 to 8 parts by weight, the content of the plasticizer is 5 to 6 parts by weight, and the content of the vulcanization accelerator is 5 to 7 parts by weight, with respect to 100 parts by weight of the base rubber.

3. The composition according to claim 1 or 2, wherein, The coupling agent is a silane coupling agent having the structure R-(SiX1X2X3) m wherein, R is an aliphatic hydrocarbon group containing at least one group selected from the group consisting of a vinyl group, an epoxy group, an amino group, a methacryloyloxy group, a mercapto group, a 3-propionylthio-1-propyl group, and a polysulfide bond, or an aromatic hydrocarbon group containing at least one group selected from the group consisting of a vinyl group, an epoxy group, an amino group, a methacryloyloxy group, a mercapto group, a 3-propionylthio-1-propyl group, and a polysulfide bond; X1, X2, and X3 are each independently a hydrolyzable functional group; and m is 1 or 2.

4. The composition of claim 3, wherein, In R-(SiX1X2X3) m In the structure, X1, X2and X3are each independently methoxy, ethoxy or chloro.

5. The composition of claim 3, wherein, The silane coupling agent is at least one selected from the group consisting of γ-(methacryloyloxy)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, and bis-[γ-(triethoxysilyl)propyl]tetrasulfide.

6. The composition of claim 1 or 2, wherein, The carbon-based reinforcing agent includes carbon black I having a relatively large average particle diameter and carbon black II having a relatively small average particle diameter. The average particle size of the carbon black I is 30-40 nm, the CTAB method specific surface area is 70-90 cm 2 / g, and the DPB absorption value is 3.0-3.5 cm 3 / g; The average particle size of the carbon black II is 26-30 nm, the CTAB method specific surface area is 90-120 cm 2 / g, and the DPB absorption value is 1.02-1.13 cm 3 / g.

7. The composition of claim 6, wherein, The content weight ratio of the carbon black I to the carbon black II is 1:0.2 to 0.

8.

8. The composition of claim 7, wherein, The content weight ratio of the carbon black I to the carbon black II is 1:0.4 to 0.

7.

9. The composition of claim 1 or 2, wherein, The graphene is reduced graphene and / or oxidized graphene.

10. The composition of claim 1 or 2, wherein, The vulcanizing agent is at least one selected from the group consisting of resin-based vulcanizing agents.

11. The composition of claim 10, wherein, The vulcanizing agent is at least one selected from the group consisting of phenolic resin-based vulcanizing agents.

12. The composition of claim 1 or 2, wherein, The vulcanization active agent is an inorganic active agent and / or an organic active agent; the inorganic active agent is at least one selected from indirect zinc oxide, direct zinc oxide and active zinc oxide, and the organic active agent is at least one selected from lauric acid, octanoic acid and stearic acid.

13. The composition of claim 12, wherein, The vulcanization active agent is an inorganic active agent and an organic active agent, the content of the organic active agent is 0.2-1 parts by weight based on 100 parts by weight of rubber, and the content of the inorganic active agent is 2-5 parts by weight.

14. The composition of claim 1 or 2, wherein, The petroleum-based plasticizer is at least one selected from naphthenic oil, aromatic oil, paraffin wax, microcrystalline wax and polyethylene wax. The fatty oil-based plasticizer is at least one selected from glycerol, castor oil, soybean oil and oleic acid.

15. The composition of claim 1 or 2, wherein, The vulcanization accelerator is at least one selected from halogen-containing vulcanization accelerators.

16. The composition of claim 15, wherein, The vulcanization accelerator is at least one selected from chloroprene rubber and brominated butyl rubber.

17. A method of producing a vulcanized rubber, characterized by, The method comprises mixing the components in the heat-conducting rubber composition of any one of claims 1-16 to form a rubber compound, and vulcanizing the rubber compound.

18. The method of claim 17, wherein, The step of mixing the components comprises: (1) masterbatching the main rubber, graphene, coupling agent and homogenizing agent to obtain a master compound; (2) first mixing the master compound with the carbon-based reinforcing agent, vulcanization active agent, plasticizer and vulcanization accelerator with the master compound to obtain a first mixed compound; (3) second mixing the vulcanizing agent with the first mixed compound to obtain the rubber compound.

19. The method of claim 17, wherein, The masterbatching conditions at least satisfy: temperature of 70-140°C and time of 3-6 min.

20. The method of claim 19, wherein, The masterbatching conditions at least satisfy: temperature of 90-120°C and time of 4-5 min.

21. The method of any of claims 18-20, wherein, The first mixing conditions at least satisfy: mixing temperature of 90-170°C and mixing time of 3-10 min.

22. The method of claim 21, wherein, The first mixing conditions at least satisfy: mixing temperature of 145-150°C and mixing time of 3-5 min.

23. The method of any one of claims 18-20, wherein, The second mixing conditions at least satisfy: mixing temperature of not higher than 120°C and mixing time of 1-7 min.

24. The method of claim 23, wherein, The second mixing conditions at least satisfy: mixing temperature of 90-115°C and mixing time of 1-3 min.

25. The method of any one of claims 17-20, wherein, The vulcanizing conditions at least satisfy: vulcanizing temperature of 140-210°C, vulcanizing time of 5-50 min and vulcanizing pressure of 3-20 MPa.

26. Vulcanized rubber prepared by the method of any one of claims 17-25.

27. Use of the vulcanized rubber of claim 26 in preparing a vulcanized capsule.

28. Use of the rubber composition of any one of claims 1-16 in preparing a vulcanized capsule rubber.

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