Rubber plate as well as preparation method and application thereof

Abstract

The invention relates to a rubber plate as well as a preparation method and application thereof. The rubber plate is prepared from the following raw materials in parts by weight: 100 parts of butyl rubber, 65-75 parts of carbon black, 5-20 parts of reinforcing filler, 5-10 parts of processing oil, 2-5 parts of protective wax and 5-12 parts of vulcanizing agent. According to the rubber plate and the preparation method thereof, the carbon black, the reinforcing filler, the processing oil and the protective wax with specific dosages are added into the preparation raw materials of the rubber plate, and several additives are matched with one another, so that the rubber plate of which the viscosity, the hardness, the tensile strength, the elasticity and other properties meet the requirements is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber technology, in particular to a rubber plate and a preparation method and application thereof. BACKGROUND

[0002] With the development of China's aerospace industry, the demand for high-temperature-resistant composite materials gradually increases, and as an auxiliary material for vacuum bag molding, the demand for high-temperature-resistant rubber plates also increases. In the curing process, the high-temperature-resistant rubber plate can uniformly transfer temperature and pressure, thereby making the surface of the cured composite material smooth and flat, and is particularly suitable for the molding of complex-shaped parts (such as sharp corners, edges and curved surfaces). High-quality products can be produced using high-temperature-resistant rubber plates.

[0003] CN101921551A discloses a high-temperature-resistant vacuum bag sealing tape, which is prepared by mixing and stirring butyl rubber, chlorobutyl rubber, polyisobutylene and nano calcium carbonate as the main matrix, and then adding a hidden high-temperature vulcanizing agent, and then extruding to form a high-temperature-resistant vacuum bag sealing tape. The sealing tape does not leak air when vacuumizing, and no residual glue is left after demolding, has good high-temperature resistance, and the maximum high-temperature resistance can reach 220℃. CN102796462A discloses a high-temperature-resistant vacuum bag sealing tape, which is prepared by mixing and stirring butyl rubber, chlorobutyl rubber, cashew phenol modified phenolic resin, nano calcium carbonate, glass fiber, ultra-fine talc powder, zinc oxide, stearic acid, tackifying resin, titanium white powder and dioctyl phthalate, and then extruding. In the manufacturing process of fan blades and aircraft, the sealing tape does not leak air when vacuumizing, and the maximum use temperature can reach 425℃, and no residual glue is left on the mold when the sealing tape is separated from the mold. CN103289583A discloses an organic silicon vacuum bag sealing tape, which is prepared by mixing and stirring 100 parts of silicone rubber, 20-70 parts of reinforcing filler, 0.5-3.0 parts of high-temperature vulcanizing agent, 0-100 parts of inert filler, 0-15 parts of heat stabilizer and 5-20 parts of structure control agent. After the organic silicon vacuum bag sealing tape is subjected to a 350℃×4 h aging test, the tape does not crack or flow, and can be peeled off as a whole, and the maximum temperature is 380℃ when the weight loss rate is 5%, which shows good high-temperature resistance and process performance.

[0004] In use, the high-temperature-resistant rubber plate is usually cut into a rubber strip with a smaller width as a rubber blocking strip. This use requires the rubber plate to have a low viscosity to prevent the rubber strips from sticking together and being unable to be pulled apart. However, there is still no high-temperature-resistant rubber plate with low viscosity and low hardness in the prior art.

[0005] Therefore, it is an urgent problem to be solved to develop a rubber plate with good use experience, low viscosity and low hardness. SUMMARY

[0006] To solve the above technical problems, the present application aims to provide a rubber plate and its preparation method and application. The present application designs the raw materials for preparing the rubber plate, and further adds carbon black and reinforcing fillers in the raw materials for preparing the rubber plate in a certain proportion, so that the rubber plate has lower hardness and viscosity, higher tensile strength, elongation at break and elasticity.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In the first aspect, the present application provides a rubber plate, the raw materials for preparing the rubber plate include the following components by weight fraction: butyl rubber 100 parts, carbon black 65-75 parts, reinforcing filler 5-20 parts, processing oil 5-10 parts, protective wax 2-5 parts and vulcanizing agent 5-12 parts.

[0009] The weight fraction of the carbon black is 65-75 parts, for example, it can be 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts or 74 parts, etc.

[0010] The weight fraction of the reinforcing filler is 5-20 parts, for example, it can be 7 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts or 18 parts, etc.

[0011] The weight fraction of the processing oil is 5-10 parts, for example, it can be 6 parts, 7 parts, 7.5 parts, 8 parts or 9 parts, etc.

[0012] The weight fraction of the protective wax is 2-5 parts, for example, it can be 2.5 parts, 3 parts, 3.5 parts, 4 parts or 4.5 parts, etc.

[0013] The weight fraction of the vulcanizing agent is 5-12 parts, for example, it can be 6 parts, 7 parts, 8 parts, 9 parts, 10 parts or 11 parts, etc.

[0014] In the present application, butyl rubber is selected because it has good air tightness and high temperature resistance.

[0015] In the present application, carbon black and reinforcing filler are added to the raw materials for preparing the rubber plate. The carbon black is the main filler, which increases the elasticity of the rubber in the rubber compound. However, if only carbon black is added, the hardness of the prepared rubber plate is too high, which is not suitable for use as a rubber blocking strip in vacuum bag molding. Therefore, the reinforcing filler is added as a secondary filler, which can dilute the carbon black, maintain the elasticity of the rubber plate at a lower hardness, and endow the rubber plate with higher tensile strength, higher elongation at break and lower tackiness. In the present application, by using a specific amount of carbon black and a specific amount of reinforcing filler, the mass ratio of carbon black to reinforcing filler is in the range of (3.25-15):1, and a rubber plate with excellent comprehensive performance is prepared. If the mass ratio of carbon black to reinforcing filler is too high, the hardness of the rubber plate is too high, the elasticity is poor, and it is not suitable for use as a rubber blocking strip; if the mass ratio of carbon black to reinforcing filler is too low, the tensile strength of the rubber plate decreases.

[0016] In the present application, the addition of processing oil to the raw materials for preparing the rubber plate can adjust the hardness of the rubber plate, improve the temperature resistance of the rubber plate, and further improve the processing performance of the rubber plate. If the weight fraction of the processing oil is less than 5 parts, the temperature resistance of the rubber plate decreases and the hardness increases; if the weight fraction of the processing oil is more than 10 parts, the processing oil is easily thermally separated at high temperature, which affects the performance of the rubber plate.

[0017] In the present application, the addition of protective wax to the raw materials for preparing the rubber plate can improve the dispersibility of the raw materials and reduce the tackiness of the rubber plate. If the weight fraction of the protective wax is less than 2 parts, the tackiness of the rubber plate increases; if the weight fraction of the anti-skid wax is more than 5 parts, thermal separation easily occurs at high temperature, which affects the performance of the rubber plate.

[0018] In the present application, the specific amounts of carbon black, reinforcing filler, processing oil and protective wax cooperate with each other to obtain a rubber plate with properties such as tackiness, hardness, tensile strength and elasticity meeting the requirements.

[0019] Preferably, the butyl rubber has a Mooney viscosity ML(1+4) 100℃ of 30-35, for example, it can be 31, 32, 32.5, 33 or 34, etc.

[0020] In the present application, the butyl rubber with a Mooney viscosity ML(1+4) 100℃ of 30-35 has better processing performance, which can further improve the performance of the rubber plate. This is because, when the Mooney viscosity is in this range, the dispersibility of the rubber compound is good, the surface gloss of the rubber sheet is high in the subsequent extrusion stage, and the physical properties can be maintained well.

[0021] In the present application, the test method for the Mooney viscosity ML(1+4) 100℃ of the butyl rubber is as follows: the test temperature is 100℃±0.5℃, the preheating time of the test sample is 1 min, the test time is 4 min, and then the test data is read and the average value of two test data values is calculated.

[0022] In the present application, the butyl rubber exemplarily includes but is not limited to butyl rubber IIR532.

[0023] Preferably, the average particle size of the carbon black is 35-55 nm, for example, can be 36 nm, 37 nm, 38 nm, 39 nm, 40 nm, 41 nm, 42 nm, 43 nm, 44 nm, 45 nm, 46 nm, 47 nm, 48 nm, 49 nm, 50 nm, 51 nm, 52 nm, 53 nm or 54 nm, etc.

[0024] In the present application, the average particle size of the carbon black should be within a proper range. If the average particle size is less than 35 nm, the elasticity of the rubber sheet decreases, the elongation at break decreases, and the dispersibility of the raw materials for preparation becomes poor; if the average particle size is greater than 55 nm, the tensile strength decreases.

[0025] In the present application, the carbon black exemplarily includes but is not limited to carbon black N660.

[0026] Preferably, the reinforcing filler includes any one or a combination of at least two of silicate, diatomite, carbon black or calcium carbonate, and is further preferably silicate.

[0027] Preferably, the silicate includes strongwei powder and / or magnesium strong powder, and is further preferably strongwei powder.

[0028] In the present application, using strongwei powder as the reinforcing filler can make the rubber sheet obtain lower hardness, viscosity, and higher elongation at break and tensile strength at the same dosage.

[0029] Preferably, the processing oil includes any one or a combination of at least two of aromatic oil, naphthenic oil or paraffin oil, and is further preferably paraffin oil.

[0030] Preferably, the flash point of the processing oil is ≥300℃, for example, can be 320℃, 340℃, 350℃, 360℃ or 380℃, etc.

[0031] In the present application, using processing oil with higher flash point can improve the temperature resistance of the rubber sheet.

[0032] In the present application, the processing oil exemplarily includes but is not limited to rubber oil 2280.

[0033] Preferably, the protective wax includes any one or a combination of at least two of polyethylene wax, paraffin wax or microcrystalline wax, and is further preferably polyethylene wax.

[0034] In the present application, the polyethylene wax has shorter chain and lower viscosity, which is easy to process. The use of polyethylene wax as protective wax can improve the physical properties of the rubber sheet.

[0035] Preferably, the viscosity of the protective wax at 149℃ is 10-20 cP, for example, it can be 12 cP, 14 cP, 15 cP, 16 cP or 18 cP, etc.

[0036] Preferably, the vulcanizing agent comprises a vulcanized resin.

[0037] Preferably, the softening point of the vulcanized resin is 80-90℃, for example, it can be 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃ or 89℃, etc.

[0038] In the present application, the vulcanized resin with lower softening point is used, which is easy to process. If the softening point of the vulcanized resin is higher than 90℃, the processing performance is poor, which affects the physical properties of the rubber sheet.

[0039] In the present application, the vulcanized resin exemplarily comprises, but is not limited to, vulcanized resin SP1045.

[0040] Preferably, the raw materials for preparing the rubber sheet further comprise a dispersant.

[0041] Preferably, the weight fraction of the dispersant in the raw materials for preparing the rubber sheet is 1-3 parts, for example, it can be 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts or 2.8 parts, etc.

[0042] Preferably, the dispersant comprises any one or a combination of at least two of sodium dodecyl benzene sulfonate, cetyl trimethyl ammonium bromide or sodium α-alkenyl sulfonate.

[0043] Preferably, the raw materials for preparing the rubber sheet further comprise an antioxidant.

[0044] Preferably, the weight fraction of the antioxidant in the raw materials for preparing the rubber sheet is 1-3 parts, for example, it can be 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts or 2.8 parts, etc.

[0045] Preferably, the antioxidant comprises an amine antioxidant.

[0046] Preferably, the antioxidant comprises any one or a combination of at least two of 2-mercaptobenzimidazole (antioxidant MB), N-isopropyl-N'-phenyl-p-phenylenediamine or N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine.

[0047] Preferably, the raw materials for preparing the rubber sheet further comprise stearic acid and zinc oxide.

[0048] Preferably, the weight fraction of stearic acid in the preparation raw materials of the rubber plate is 2-3 parts, for example, it can be 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts or 2.9 parts, etc.

[0049] Preferably, the weight fraction of zinc oxide in the preparation raw materials of the rubber plate is 3-5 parts, for example, it can be 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts or 4.8 parts, etc.

[0050] In the second aspect, the application provides a preparation method of the rubber plate according to the first aspect, characterized in that the preparation method of the rubber plate comprises the following steps:

[0051] (1) preparing a first-stage glue: mixing all the preparation raw materials of the rubber plate except the vulcanizing agent, and obtaining the first-stage glue after uniform mixing;

[0052] (2) preparing a second-stage glue: mixing the first-stage glue and the vulcanizing agent in an internal mixer to obtain the second-stage glue;

[0053] (3) preparing the rubber plate: sequentially performing extrusion and calendering on the second-stage glue to obtain the rubber plate.

[0054] In the application, the rubber is first compacted in an extruder, and then molded by a calender, so that a rubber plate with smooth surface and no bubbles can be obtained.

[0055] Preferably, the mixing in step (1) comprises the following steps:

[0056] The butyl rubber, protective wax, optional dispersant, optional antioxidant, optional stearic acid and optional zinc oxide are first mixed to obtain a mixture A; the mixture A is secondly mixed with part of the carbon black, part of the reinforcing filler and processing oil to obtain a mixture B; the remaining carbon black and the remaining reinforcing filler are thirdly mixed with the mixture B, and then discharged to obtain the first-stage glue.

[0057] In the application, the carbon black and the reinforcing filler are both divided into two parts and added into the mixing system in steps, so that the preparation raw materials of the rubber plate can be more uniformly mixed, and the performance of the rubber plate can be improved.

[0058] Preferably, the rotation speed of the first mixing is 40-50 rpm, for example, it can be 41 rpm, 42 rpm, 43 rpm, 44 rpm, 45 rpm, 46 rpm, 47 rpm, 48 rpm or 49 rpm, etc.

[0059] Preferably, the first mixing time is 25-35 s, for example, it can be 26 s, 27 s, 28 s, 29 s, 30 s, 31 s, 32 s, 33 s or 34 s, etc.

[0060] Preferably, the rotational speed of the second mixing is 25-40 rpm, for example, it can be 27 rpm, 29 rpm, 30 rpm, 32 rpm, 34 rpm, 36 rpm or 39 rpm, etc.

[0061] Preferably, during the second mixing process, the second mixing is stopped after the temperature of the mixing system reaches 100-105°C.

[0062] The 100-105℃ can be, for example, 101℃, 102℃, 102.5℃, 103℃, or 104℃.

[0063] Preferably, the third mixing includes low-temperature mixing and high-temperature mixing.

[0064] Preferably, the rotation speed of the low-temperature mixing is 25-40 rpm, for example, it can be 27 rpm, 29 rpm, 30 rpm, 32 rpm, 34 rpm, 36 rpm or 39 rpm, etc.

[0065] Preferably, during the low-temperature mixing process, the low-temperature mixing is stopped after the temperature of the mixing system reaches 115-125°C.

[0066] The 115-125℃ can be, for example, 116℃, 117℃, 118℃, 119℃, 120℃, 121℃, 122℃, 123℃, or 124℃, etc.

[0067] Preferably, the rotation speed of the high-temperature mixing is 20-30 rpm, for example, it can be 21 rpm, 22 rpm, 23 rpm, 24 rpm, 25 rpm, 26 rpm, 27 rpm, 28 rpm or 29 rpm, etc.

[0068] Preferably, during the high-temperature mixing process, the high-temperature mixing is stopped after the temperature of the mixing system reaches 135-145°C.

[0069] The 135-145℃ can be, for example, 136℃, 137℃, 138℃, 139℃, 140℃, 141℃, 142℃, 143℃, or 144℃, etc.

[0070] In this invention, the system is first preheated to about 70°C by external heating, and then the external heating is removed, relying on the shear friction between the raw materials during glue application to further raise the temperature.

[0071] Preferably, the mixing speed is 18-25 rpm, for example, it can be 19 rpm, 20 rpm, 21 rpm, 22 rpm, 23 rpm or 24 rpm, etc.

[0072] Preferably, the mixing process begins after the temperature of the mixing system reaches 75-85°C.

[0073] The 75-85℃ can be, for example, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, or 84℃, etc.

[0074] Preferably, the mixing process is stopped after the temperature of the mixing system reaches 100-110°C.

[0075] The 100-110℃ can be, for example, 101℃, 102℃, 103℃, 104℃, 105℃, 106℃, 107℃, 108℃, or 109℃, etc.

[0076] Preferably, the extrusion and calendering temperatures are each independently 80-90°C, for example, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, or 89°C.

[0077] Thirdly, the present invention provides an application of the rubber sheet as described in the first aspect in a rubber retaining strip.

[0078] Compared with the prior art, the present invention has at least the following beneficial effects:

[0079] In this invention, by adding specific amounts of carbon black, reinforcing filler, processing oil and protective wax to the raw materials for preparing rubber sheets, several additives work together to obtain rubber sheets with properties such as viscosity, hardness, tensile strength and elasticity that meet the requirements. Detailed Implementation

[0080] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0081] Some of the raw materials used in the examples and comparative examples are as follows:

[0082] Butyl rubber IIR532: purchased from Zhejiang Xinhui; Mooney viscosity ML(1+4) at 100℃ is 32;

[0083] Carbon black N660: purchased from Jiangxi Black Cat; average particle size is 40-50 nm;

[0084] Strong Power Powder: Purchased from Shanghai Qixiang; Brand name: KTC;

[0085] Rubber oil 2280: purchased from Ningbo Xiejin Chemical Co., Ltd.;

[0086] Polyethylene wax: purchased from Qingdao Haihao Innovation Technology Co., Ltd.; grade H110;

[0087] Vulcanizing resin SP1045: purchased from Saint-Gobain; softening point is 80-90℃;

[0088] Calcium carbonate: purchased from Changxing Huayang;

[0089] Magnesium-strength powder: purchased from Sequoia Polymer Materials; grade M15.

[0090] Example 1

[0091] This embodiment provides a rubber sheet and its preparation method. The raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 70 parts of carbon black N660, 10 parts of strong iodine powder, 8 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0092] The method for preparing the rubber sheet includes the following steps:

[0093] (1) Preparation of a first-stage rubber: Butyl rubber IIR532, polyethylene wax, sodium dodecylbenzenesulfonate, 2-mercaptobenzimidazole, stearic acid and zinc oxide are mixed for the first time. The first mixing speed is 40-50 rpm and the first mixing time is 30 s to obtain mixture A;

[0094] Mixture A is mixed a second time with carbon black accounting for 50% of the total mass of carbon black, strong powder accounting for 50% of the total mass of strong powder, and rubber oil 2280. The rotation speed of the second mixing is 25-40 rpm. After the temperature of the mixing system reaches 100℃, the top plug is raised to stop the second mixing, and mixture B is obtained.

[0095] Add the remaining carbon black and remaining strong powder to mixture B, lower the top bolt to carry out low-temperature mixing. The rotation speed of the low-temperature mixing is 25-40 rpm. After the temperature of the mixing system reaches 120°C, raise the top bolt to clean and stop the low-temperature mixing.

[0096] The top plug is lowered to carry out high-temperature mixing. The high-temperature mixing speed is 20-30 rpm. When the temperature of the mixing system reaches 140°C, the top plug is raised to stop the high-temperature mixing. The mixture is then cooled to obtain the first section of adhesive.

[0097] (2) Preparation of two-stage rubber: The first-stage rubber is put into an internal mixer and internally mixed at a speed of 18-25 rpm. When the temperature of the mixing system reaches 80°C, vulcanizing resin SP1045 is added. When the temperature of the mixing system reaches 95°C, the top bolt is raised for cleaning and then lowered. When the temperature of the mixing system reaches 105°C, the material is unloaded and cooled to obtain the second-stage rubber.

[0098] (3) Preparation of rubber sheet: The two-stage rubber is extruded, calendered and wound in sequence. The extrusion temperature is 80-90℃ and the calendering temperature is 80-90℃ to obtain the rubber sheet.

[0099] Example 2

[0100] This embodiment provides a rubber sheet and its preparation method. The raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 68 parts of carbon black N660, 12 parts of strong iodine powder, 5 parts of rubber oil 2280, 5 parts of polyethylene wax, 12 parts of vulcanizing resin SP1045, 1 part of sodium dodecylbenzenesulfonate, 3 parts of 2-mercaptobenzimidazole, 2 parts of stearic acid, and 5 parts of zinc oxide.

[0101] The method for preparing the rubber sheet includes the following steps:

[0102] (1) Preparation of a first-stage rubber: Butyl rubber IIR532, polyethylene wax, sodium dodecylbenzenesulfonate, 2-mercaptobenzimidazole, stearic acid and zinc oxide are mixed for the first time. The mixing speed is 40-50 rpm and the mixing time is 35 s to obtain mixture A.

[0103] Mixture A is mixed a second time with carbon black accounting for 50% of the total mass of carbon black, strong powder accounting for 50% of the total mass of strong powder, and rubber oil 2280. The rotation speed of the second mixing is 25-40 rpm. After the temperature of the mixing system reaches 100℃, the top plug is raised to stop the second mixing, and mixture B is obtained.

[0104] Add the remaining carbon black and remaining strong powder to mixture B, lower the top bolt to carry out low-temperature mixing. The rotation speed of the low-temperature mixing is 25-40 rpm. After the temperature of the mixing system reaches 125°C, raise the top bolt to clean and stop the low-temperature mixing.

[0105] The top plug is lowered to carry out high-temperature mixing. The high-temperature mixing speed is 20-30 rpm. When the temperature of the mixing system reaches 135°C, the top plug is raised to stop the high-temperature mixing. The mixture is then cooled to obtain the first section of adhesive.

[0106] (2) Preparation of two-stage rubber: The first-stage rubber is put into an internal mixer and internally mixed at a speed of 18-25 rpm. When the temperature of the mixing system reaches 80°C, vulcanizing resin SP1045 is added. When the temperature of the mixing system reaches 95°C, the top bolt is raised for cleaning and then lowered. When the temperature of the mixing system reaches 105°C, the material is unloaded and cooled to obtain the second-stage rubber.

[0107] (3) Preparation of rubber sheet: The two-stage rubber is extruded, calendered and wound in sequence. The extrusion temperature is 80-90℃ and the calendering temperature is 80-90℃ to obtain the rubber sheet.

[0108] Example 3

[0109] This embodiment provides a rubber sheet and its preparation method. The raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 72 parts of carbon black N660, 8 parts of strong iodine powder, 10 parts of rubber oil 2280, 2 parts of polyethylene wax, 5 parts of vulcanizing resin SP1045, 3 parts of sodium dodecylbenzenesulfonate, 1 part of 2-mercaptobenzimidazole, 3 parts of stearic acid, and 3 parts of zinc oxide.

[0110] The method for preparing the rubber sheet includes the following steps:

[0111] (1) Preparation of a first-stage rubber: Butyl rubber IIR532, polyethylene wax, sodium dodecylbenzenesulfonate, 2-mercaptobenzimidazole, stearic acid and zinc oxide are mixed for the first time. The first mixing speed is 40-50 rpm and the first mixing time is 25 s to obtain mixture A;

[0112] Mixture A is mixed a second time with carbon black accounting for 50% of the total mass of carbon black, strong powder accounting for 50% of the total mass of strong powder, and rubber oil 2280. The rotation speed of the second mixing is 25-40 rpm. After the temperature of the mixing system reaches 105℃, the top plug is raised to stop the second mixing, and mixture B is obtained.

[0113] Add the remaining carbon black and remaining strong powder to mixture B, lower the top bolt to carry out low-temperature mixing. The rotation speed of the low-temperature mixing is 25-40 rpm. After the temperature of the mixing system reaches 115℃, raise the top bolt to clean and stop the low-temperature mixing.

[0114] The top plug is lowered to carry out high-temperature mixing. The high-temperature mixing speed is 20-30 rpm, and the temperature of the mixing system reaches 145°C. The top plug is then raised to stop the high-temperature mixing, and the mixture is cooled to obtain the first section of adhesive.

[0115] (2) Preparation of two-stage rubber: The first-stage rubber is put into an internal mixer and internally mixed at a speed of 18-25 rpm. When the temperature of the mixing system reaches 80°C, vulcanizing resin SP1045 is added. When the temperature of the mixing system reaches 95°C, the top bolt is raised for cleaning and then lowered. When the temperature of the mixing system reaches 105°C, the material is unloaded and cooled to obtain the second-stage rubber.

[0116] (3) Preparation of rubber sheet: The two-stage rubber is extruded, calendered and wound in sequence. The extrusion temperature is 80-90℃ and the calendering temperature is 80-90℃ to obtain the rubber sheet.

[0117] Example 4

[0118] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that carbon black N660 is replaced with an equal mass of carbon black N770.

[0119] Example 5

[0120] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that carbon black N660 is replaced with an equal mass of carbon black N234.

[0121] Example 6

[0122] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that the strong-coated powder is replaced with an equal mass of calcium carbonate.

[0123] Example 7

[0124] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that the raw materials for preparing the rubber sheet do not contain strong iodine powder, and the weight parts of carbon black N660 are increased to 80 parts.

[0125] Example 8

[0126] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that the strong-coating powder is replaced with an equal mass of magnesium-coating powder.

[0127] Example 9

[0128] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that the polyethylene wax is replaced with an equal mass of microcrystalline wax.

[0129] Example 10

[0130] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 65 parts of carbon black N660, 15 parts of strong iodine powder, 8 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0131] Example 11

[0132] This embodiment provides a rubber sheet and its preparation method. The only difference from Embodiment 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 75 parts of carbon black N660, 5 parts of strong iodine powder, 8 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0133] Comparative Example 1

[0134] This comparative example provides a rubber sheet and its preparation method. The only difference from Example 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 76 parts of carbon black N660, 4 parts of strong iodine powder, 8 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0135] Comparative Example 2

[0136] This comparative example provides a rubber sheet and its preparation method. The only difference from Example 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 60 parts of carbon black N660, 20 parts of strong iodine powder, 8 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0137] Comparative Example 3

[0138] This comparative example provides a rubber sheet and its preparation method. The only difference from Example 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 70 parts of carbon black N660, 10 parts of strong iodine powder, 2 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0139] Comparative Example 4

[0140] This comparative example provides a rubber sheet and its preparation method. The only difference from Example 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 70 parts of carbon black N660, 10 parts of strong iodine powder, 8 parts of rubber oil 2280, 1 part of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0141] Comparative Example 5

[0142] This comparative example provides a rubber sheet and its preparation method. The only difference from Example 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 70 parts of carbon black N660, 10 parts of strong iodine powder, 12 parts of rubber oil 2280, 3 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0143] Comparative Example 6

[0144] This comparative example provides a rubber sheet and its preparation method. The only difference from Example 1 is that the raw materials for preparing the rubber sheet include the following components by weight: 100 parts of butyl rubber IIR532, 70 parts of carbon black N660, 10 parts of strong iodine powder, 8 parts of rubber oil 2280, 6 parts of polyethylene wax, 8 parts of vulcanizing resin SP1045, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of 2-mercaptobenzimidazole, 2.5 parts of stearic acid, and 4 parts of zinc oxide.

[0145] Test methods

[0146] (1) Physical properties

[0147] The rubber sheet was prepared into a 2 mm thick test piece (the length and width of the test piece were not less than the mold size) and placed in a flat vulcanizing machine for vulcanization (vulcanization temperature: 190℃, vulcanization time: 40 min, flat plate pressure: 0.6 MPa). After vulcanization, the rubber sheet was cut into dumbbell shapes for physical property testing.

[0148] Tensile strength and elongation at break: Use vernier calipers to measure the thickness and width of the sample at the gauge length. Measure the thickness and width three times each and take the average value. Calculate the cross-sectional area. Fix the sample in the clamp of the tensile testing machine, ensuring that the tensile force is perpendicular. Then start stretching until the sample breaks. Record the tensile strength and elongation at break. Test four samples for each sample. Remove the maximum and minimum values ​​and take the average of the two intermediate values ​​as the test data.

[0149] Hardness: Prepare a rubber block with a thickness of 1 cm and a length and width of 3 cm and vulcanize it. After vulcanization, place it at room temperature for more than 4 hours. Press the hardness tester vertically on the sample for measurement and take the reading after holding it for 3 seconds. Test each sample 5 times and take the average value as the test data.

[0150] Specific gravity: To calibrate the electronic densitometer, weigh a 1.5±0.3 g sample, then place the sample in water, gently shake to remove air bubbles, weigh the water, and then display the specific gravity value on the electronic densitometer.

[0151] (2) High temperature resistance

[0152] The pressure-equalizing rubber sheet was placed in an autoclave at 205℃ with an external pressure of 0.6 MPa for 2 hours. After cooling to room temperature, the surface of the rubber sheet was observed. If there were no visible changes such as cracks, spalling, or exudation on the surface of the rubber sheet, it was considered to have good high-temperature resistance.

[0153] (3) Viscosity Qualitative Test

[0154] Cut the rubber sheet into strips 10 mm wide and 30 cm long, totaling approximately 100 strips. Randomly place the strips into a 30 cm × 30 cm × 30 cm box and incubate at room temperature for 24 hours. Remove the strips afterward. If all strips are easily separated without sticking together, and the separated rubber sheet does not deform, the adhesion is acceptable. If the strips are stuck together and cannot be separated, the adhesion is unacceptable.

[0155] (4) Initial tack test

[0156] After the annular sample is brought into complete contact with the standard float glass test plate at a constant speed of 300 mm / min, the annular sample and the test plate are automatically separated in the opposite direction at a constant speed of 300 mm / min. The peak force value recorded by the annular initial tack tester is the initial tack of the sample.

[0157] The test results are shown in Table 1.

[0158] Table 1

[0159]

[0160] The test results show that:

[0161] (1) As can be seen from Examples 1-11, the present invention obtains a rubber sheet with the required properties such as viscosity, hardness, tensile strength and elasticity by using a specific amount of carbon black, reinforcing filler, processing oil and protective wax in combination. The initial tack is ≤4.8, the hardness is 55-67, the tensile strength is ≥10.1 MPa and the elongation at break is ≥490%.

[0162] (2) By comparing Example 1 with Examples 4-5, it can be seen that the present invention can improve the elongation at break and tensile strength of rubber sheet by further limiting the average particle size of carbon black.

[0163] (3) By comparing Example 1 with Examples 6-8, it can be seen that by further limiting the types of reinforcing fillers, the present invention can reduce the hardness and initial tack of the rubber sheet and improve the elongation at break and tensile strength.

[0164] (4) By comparing Example 1 and Example 9, it can be seen that the present invention can improve the physical properties of rubber sheets by further limiting the type of protective wax.

[0165] (5) As can be seen from the comparison between Example 1 and Comparative Examples 1-2, the present invention, by limiting the amount of carbon black and reinforcing filler within a specific range, can maintain the elasticity of the rubber sheet at a lower hardness and endow the rubber sheet with higher tensile strength, higher elongation at break, and lower viscosity. In Comparative Examples 1-2, because the amount of carbon black and reinforcing filler is not within a specific range, the mass ratio of carbon black to reinforcing filler is too large or too small, which in turn affects the performance of the rubber sheet.

[0166] (6) By comparing Example 1 with Comparative Examples 3-6, it can be seen that by limiting the amount of processing oil and protective wax, the present invention can reduce the stickiness and hardness of the rubber sheet and improve the high temperature resistance of the rubber sheet.

[0167] In summary, by combining specific amounts of carbon black, reinforcing filler, processing oil, and protective wax, a rubber sheet with properties such as viscosity, hardness, tensile strength, and elasticity that meet the requirements was obtained.

[0168] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A rubber sheet, characterized in that, The raw materials for preparing the rubber sheet include the following components by weight: 100 parts butyl rubber, 65-75 parts carbon black, 5-20 parts reinforcing filler, 5-10 parts processing oil, 2-5 parts protective wax, and 5-12 parts vulcanizing agent.

2. The rubber sheet according to claim 1, characterized in that, The Mooney viscosity ML(1+4) of the butyl rubber at 100°C is 30-35.

3. The rubber sheet according to claim 1 or 2, characterized in that, The average particle size of the carbon black is 35-55 nm; Preferably, the reinforcing filler comprises any one or a combination of at least two of silicates, diatomaceous earth, carbon black or calcium carbonate, and more preferably silicates; Preferably, the silicate comprises strong silicate powder and / or magnesium silicate powder, and more preferably strong silicate powder.

4. The rubber sheet according to any one of claims 1-3, characterized in that, The processing oil includes any one or a combination of at least two of aromatic oils, naphthenic oils, or paraffin oils, with paraffin oils being more preferred. Preferably, the flash point of the processing oil is ≥300℃; Preferably, the protective wax comprises any one or a combination of at least two of polyethylene wax, paraffin wax, or microcrystalline wax, and more preferably polyethylene wax; Preferably, the viscosity of the protective wax at 149°C is 10-20 cP.

5. The rubber sheet according to any one of claims 1-4, characterized in that, The vulcanizing agent includes a vulcanizing resin; Preferably, the softening point of the vulcanized resin is 80-90℃.

6. The rubber sheet according to any one of claims 1-5, characterized in that, The raw materials for preparing the rubber sheet also include dispersants; Preferably, the dispersant in the raw materials for preparing the rubber sheet is 1-3 parts by weight; Preferably, the dispersant comprises any one or a combination of at least two of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, or sodium α-alkenylsulfonate; Preferably, the raw materials for preparing the rubber sheet also include an antioxidant; Preferably, the antioxidant in the raw materials for preparing the rubber sheet is 1-3 parts by weight; Preferably, the antioxidant includes amine antioxidants; Preferably, the antioxidant comprises any one or a combination of at least two of 2-mercaptobenzimidazole, N-isopropyl-N'-phenyl-p-phenylenediamine, or N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine; Preferably, the raw materials for preparing the rubber sheet also include stearic acid and zinc oxide; Preferably, the raw materials for preparing the rubber sheet contain 2-3 parts by weight of stearic acid; Preferably, the raw materials for preparing the rubber sheet contain 3-5 parts by weight of zinc oxide.

7. A method for preparing a rubber sheet as described in any one of claims 1-6, characterized in that, The method for preparing the rubber sheet includes the following steps: (1) Preparation of a first-stage rubber: Mix all the raw materials for preparing rubber sheets except for the vulcanizing agent, and after mixing evenly, the first-stage rubber is obtained; (2) Preparation of two-stage rubber: The first-stage rubber is mixed with a vulcanizing agent to obtain the second-stage rubber; (3) Preparation of rubber sheet: The two-stage rubber is extruded and calendered in sequence to obtain the rubber sheet.

8. The method for preparing a rubber sheet according to claim 7, characterized in that, The mixing in step (1) includes the following steps: Butyl rubber, protective wax, optional dispersant, optional antioxidant, optional stearic acid, and optional zinc oxide are first mixed to obtain mixture A; mixture A is second mixed with a portion of carbon black, a portion of reinforcing filler, and processing oil to obtain mixture B; the remaining carbon black and the remaining reinforcing filler are third mixed with mixture B and then discharged to obtain the aforementioned rubber section. Preferably, the rotational speed of the first mixing is 40-50 rpm; Preferably, the first mixing time is 25-35 s; Preferably, the rotational speed of the second mixing is 25-40 rpm; Preferably, during the second mixing process, the second mixing is stopped after the temperature of the mixing system reaches 100-105°C; Preferably, the third mixing includes low-temperature mixing and high-temperature mixing; Preferably, the rotation speed of the low-temperature mixing is 25-40 rpm; Preferably, during the low-temperature mixing process, the low-temperature mixing is stopped after the temperature of the mixing system reaches 115-125°C. Preferably, the rotation speed of the high-temperature mixing is 20-30 rpm; Preferably, during the high-temperature mixing process, the high-temperature mixing is stopped after the temperature of the mixing system reaches 135-145°C.

9. The method for preparing a rubber sheet according to claim 7 or 8, characterized in that, The mixing speed is 18-25 rpm; Preferably, the extrusion and calendering temperatures are each independently 80-90°C.

10. The use of a rubber sheet as described in any one of claims 1-6 in a backing strip.

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