A run-flat inner tube rubber composition and a method for producing the same

Abstract

The application discloses a kind of anti-inflating inner tube rubber compositions and preparation method thereof, belong to rubber composition preparation technical field.The composition is composed of the following components: butyl rubber, modified ethylene-propylene-diene rubber, polyester nanofiber, soft carbon black, paraffin oil, silane coupling agent, activator, petroleum resin, antioxidant, vulcanizing agent, accelerator;The silane coupling agent is the mixture of silane coupling agent Si-69, gamma-(methacryloyloxy) propyl trimethyl silane and N-(beta-aminoethyl)-gamma-aminopropyl trimethyl (ethyl) oxysilane with mass ratio 2:1:1.The air retention and inflation stability of the composition can be greatly improved by modifying ethylene-propylene-diene rubber, limiting the proportion of butyl rubber, and limiting the substance and ratio of silane coupling agent, which improves the service life and safety performance of the inner tube.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber composition preparation, and particularly provides a rubber composition for anti-inflating inner tube and a preparation method thereof. BACKGROUND

[0002] It is known that in recent years, with the improvement of road conditions in China and the development of expressways, the driving speed of automobiles is greatly increased, and the phenomenon of overloading is common, which continuously increases the temperature of the tire in use and intensifies the deformation of the inner tube. Higher requirements are put forward for the high-temperature resistance and low deformation of the inner tube during long-time operation based on vehicle driving and user safety. Although the butyl inner tube has excellent air tightness, good heat resistance and ozone resistance, the all-IIR inner tube becomes soft in use, is adhered to the outer tube, and its size is enlarged, which causes the butyl inner tube to be easily inflated and wrinkled during repeated use. The thin point of the inner tube is easily damaged after assembly, which affects the driving safety of the vehicle. SUMMARY

[0003] In order to solve the problems in the prior art, the present application provides a rubber composition for anti-inflating inner tube and a preparation method thereof. The modified EPDM rubber is limited in proportion with butyl rubber, and the silane coupling agent is limited in substance and ratio, so that the air retention and inflation stability of the composition can be greatly improved, and the service life and safety performance of the inner tube are improved.

[0004] To solve the above technical problems, the technical scheme of the present application is as follows:

[0005] In one aspect, the present application provides a rubber composition for anti-inflating inner tube, which is composed of the following components in parts by weight: butyl rubber 50-100 parts; modified EPDM rubber 5-50 parts; polyester nanofiber 1-10 parts; soft carbon black 5-35 parts; paraffin oil 5-30 parts; silane coupling agent 1-10 parts; activator 5-30 parts; petroleum resin 0.5-3 parts; antioxidant 0.5-8 parts; vulcanizing agent 2-3 parts; accelerator 3-4.5 parts;

[0006] The weight ratio of the butyl rubber to the modified EPDM rubber is 1:1-5:1;

[0007] The amount of the silane coupling agent is 0.7-7.4% of the total weight of the butyl rubber and the modified EPDM rubber;

[0008] The polyester nanofiber has a diameter of 400-700 nm and a length of less than 1 mm;

[0009] The silane coupling agent is a mixture of silane coupling agent Si-69, gamma-(methacryloxy)propyl trimethylsilane and N-(beta-aminoethyl)-gamma-aminopropyl trimethoxy silane with a mass ratio of 2:1:1.

[0010] The butyl rubber has a Mooney viscosity of 51 and an unsaturation of 1.5%, preferably Yanshan petrochemical butyl rubber 1751.

[0011] Further, the modified ethylene-propylene-diene rubber is prepared by uniformly mixing ethylene-propylene-diene rubber and vinyl silicone rubber on a mixing mill; the front roller temperature is 100-130 DEG C, the rear roller temperature is 80-95 DEG C, and the mixing time is 3-5 min to obtain the modified ethylene-propylene-diene rubber.

[0012] Preferably, the amount of the vinyl silicone rubber is 1-3% of the mass of the ethylene-propylene-diene rubber, the ethylene-propylene-diene rubber has an ethylene content of more than 50% and a Mooney viscosity of more than 40 at 125 DEG C and 1+4.

[0013] Preferably, the activator is zinc oxide, the antioxidant is 2-mercaptobenzimidazole, the vulcanizing agent is sulfur, and the accelerator is tetraethylthiuram disulfide and benzothiazole disulfide with a mass ratio of 2:1.

[0014] In another aspect, the application also provides a preparation method of the above-mentioned anti-bulging inner tube rubber composition, comprising:

[0015] Step 1: weigh each raw material for use;

[0016] Step 2: put butyl rubber, modified ethylene-propylene-diene rubber, polyester nanofiber, activator, petroleum resin and antioxidant into a mixing mill, and mix at 20-45 rpm for 20-45 seconds;

[0017] Step 3: put soft carbon black and silane coupling agent into the mixing mill, and mix at a speed of 15-40 rpm for 20-45 seconds;

[0018] Step 4: add paraffin oil into the mixing mill, and mix at a speed of 20-45 rpm until the temperature reaches 150-180 DEG C, then discharge to obtain a masterbatch;

[0019] Step 5: put the masterbatch, accelerator and vulcanizing agent into the mixing mill, and mix at a speed of 15-50 rpm until the temperature reaches 85-135 DEG C, then discharge.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] The application can greatly improve the air retention and inflation stability of the composition by modifying the EPDM rubber, limiting the proportion of the EPDM rubber and the butyl rubber, and limiting the substance and proportion of the silane coupling agent, solves the technical problems that the inner tube is easy to deform, is easy to expand when repeatedly used, and the pleat and thin point are easy to be damaged after assembly, and improves the service life and safety performance of the inner tube. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and advantages of the present application clearer, specific embodiments will be described in detail below.

[0023] In the present application, the materials and reagents used are commercially available if not otherwise specified. Among them, the butyl rubber is Yanshan Petrochemical 1751; the EPDM rubber is 3666 produced by Exxon Mobil, USA; the petroleum resin is Escorez 1102 of Exxon Mobil; the polyester nanofiber has a diameter of 400-700 nm and a length of less than 1 mm.

[0024] The present application provides a kind of anti-expansion inner tube rubber composition and preparation method thereof, and the specific embodiment is as follows.

[0025] Example 1

[0026] An anti-expansion inner tube rubber composition, consisting of the following components by weight: butyl rubber 50 parts; modified EPDM rubber 50 parts; polyester nanofiber 5 parts; soft carbon black 20 parts; paraffin oil 10 parts; silane coupling agent 4 parts; zinc oxide 10 parts; petroleum resin 0.5 parts; 2-mercaptobenzimidazole 2 parts; sulfur 3 parts; accelerator 3 parts;

[0027] The above modified EPDM rubber is prepared by the following method: EPDM rubber and vinyl silicone rubber are uniformly mixed on a mixing mill; the front roller temperature is 100℃, the rear roller temperature is 80℃, and the mixing time is 5min to obtain the modified EPDM rubber. The amount of vinyl silicone rubber is 1% of the mass of EPDM rubber.

[0028] Among them, the silane coupling agent is a mixture of silane coupling agents Si-69, γ-(methacryloyloxy)propyltrimethylsilane and N-(β-aminoethyl)-γ-aminopropyltrimethyl(ethyl)oxysilane with a mass ratio of 2:1:1;

[0029] The soft carbon black is N550 and N660 with a mass ratio of 1:1.

[0030] The accelerator is tetraethylthiuram disulfide and benzothiazole disulfide with a mass ratio of 2:1.

[0031] The preparation method of the above anti-expansion inner tube rubber composition comprises:

[0032] Step 1: weigh each raw material for use;

[0033] Step 2: Put butyl rubber, modified ethylene-propylene-diene rubber, polyester nanofiber, activator, petroleum resin and antioxidant into the internal mixer, mix for 45 seconds at 20 revolutions per minute;

[0034] Step 3: Put soft carbon black and silane coupling agent into the internal mixer, mix for 20 seconds at 40 revolutions per minute;

[0035] Step 4: Add paraffin oil into the internal mixer, mix until 150℃ at 20 revolutions per minute, discharge to obtain the masterbatch;

[0036] Step 5: Put the masterbatch, accelerator and vulcanizing agent into the internal mixer, mix until 135℃ at 20 revolutions per minute, discharge.

[0037] Example 2

[0038] A kind of anti-inflatable inner tube rubber composition, which is composed of the following components by weight: butyl rubber 60 parts; modified ethylene-propylene-diene rubber 20 parts; polyester nanofiber 1 part; soft carbon black 5 parts; paraffin oil 8 parts; silane coupling agent 1 part; zinc oxide 12 parts; petroleum resin 1 part; 2-mercaptobenzimidazole 0.5 parts; sulfur 2 parts; accelerator 3.5 parts;

[0039] The modified ethylene-propylene-diene rubber is prepared by the following method: uniformly mix ethylene-propylene-diene rubber and vinyl silicone rubber on the internal mixer; the front roller temperature is 130℃, the rear roller temperature is 95℃, and the mixing time is 3min to obtain the modified ethylene-propylene-diene rubber. The amount of vinyl silicone rubber is 2% of the mass of ethylene-propylene-diene rubber.

[0040] Among them, the silane coupling agent is a mixture of silane coupling agent Si-69, γ-(methacryloyloxy) propyl trimethyl silane and N-(β-aminoethyl)-γ-aminopropyl trimethyl (ethyl) oxysilane with a mass ratio of 2:1:1.

[0041] The soft carbon black is N550 and N660 with a mass ratio of 1:1.

[0042] The accelerator is a mixture of tetraethylthiuram disulfide and benzothiazole disulfide with a mass ratio of 2:1.

[0043] The preparation method of the above anti-inflatable inner tube rubber composition is the same as that of Example 1.

[0044] Example 3

[0045] A kind of anti-inflating inner tube rubber composition, it is made of the following components by weight: butyl rubber 70 parts;Modified ethylene-propylene-diene rubber 14 parts;Polyester nanofiber 6 parts;Soft carbon black 10 parts;Paraffin oil 20 parts;Silane coupling agent 5 parts;Zinc oxide 20 parts;Petroleum resin 2 parts;2-mercapto benzimidazole 4 parts;Sulfur 3 parts;Accelerator 4 parts;

[0046] The above-mentioned modified ethylene-propylene-diene rubber is prepared by the following method: ethylene-propylene-diene rubber and vinyl silicone rubber are mixed evenly on a mixer;The front roller temperature is 120 DEG C, the rear roller temperature is 90 DEG C, and the mixing time is 4 min to obtain the modified ethylene-propylene-diene rubber. The amount of vinyl silicone rubber is 3% of the mass of ethylene-propylene-diene rubber.

[0047] Among them, the silane coupling agent is a mixture of silane coupling agent Si-69, γ- (methacryloxy) propyl trimethyl silane and N- (β-aminoethyl) -γ-aminopropyl trimethyl (ethyl) oxysilane with a mass ratio of 2:1:1.

[0048] The soft carbon black is N550 and N660 with a mass ratio of 1:1.

[0049] The accelerator is tetraethylthiuram disulfide and benzothiazole disulfide with a mass ratio of 2:1.

[0050] The preparation method of the above-mentioned anti-inflating inner tube rubber composition is the same as that of example 1.

[0051] Example 4

[0052] A kind of anti-inflating inner tube rubber composition, it is made of the following components by weight: butyl rubber 80 parts;Modified ethylene-propylene-diene rubber 20 parts;Polyester nanofiber 7 parts;Soft carbon black 20 parts;Paraffin oil 18 parts;Silane coupling agent 6 parts;Zinc oxide 30 parts;Petroleum resin 3 parts;2-mercapto benzimidazole 6 parts;Sulfur 2 parts;Accelerator 4.5 parts;

[0053] The preparation method of the above-mentioned modified ethylene-propylene-diene rubber is the same as that of example 2.

[0054] The silane coupling agent is a mixture of silane coupling agent Si-69, γ- (methacryloxy) propyl trimethyl silane and N- (β-aminoethyl) -γ-aminopropyl trimethyl (ethyl) oxysilane with a mass ratio of 2:1:1.

[0055] The soft carbon black is N550 and N660 with a mass ratio of 1:1.

[0056] The accelerator is tetraethylthiuram disulfide and benzothiazole disulfide with a mass ratio of 2:1.

[0057] The preparation method of the above-mentioned anti-inflating inner tube rubber composition is the same as that of example 1.

[0058] Example 5

[0059] A run-flat inner tube rubber composition, which is composed of the following components in parts by weight: butyl rubber 90 parts; modified ethylene-propylene-diene rubber 18 parts; polyester nanofiber 9 parts; soft carbon black 25 parts; paraffin oil 25 parts; silane coupling agent 8 parts; zinc oxide 25 parts; petroleum resin 2 parts; 2-mercaptobenzimidazole 8 parts; sulfur 3 parts; accelerator 3 parts;

[0060] The preparation method of the modified ethylene-propylene-diene rubber is the same as that in Example 2.

[0061] The silane coupling agent is a mixture of silane coupling agent Si-69, γ-(methacryloyloxy)propyltrimethylsilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxy silane in a mass ratio of 2:1:1.

[0062] The soft carbon black is N550 and N660 in a mass ratio of 1:1.

[0063] The accelerator is tetraethylthiuram disulfide and benzothiazole disulfide in a mass ratio of 2:1.

[0064] The preparation method of the run-flat inner tube rubber composition is the same as that in Example 1.

[0065] Example 6

[0066] A run-flat inner tube rubber composition, which is composed of the following components in parts by weight: butyl rubber 100 parts; modified ethylene-propylene-diene rubber 50 parts; polyester nanofiber 10 parts; soft carbon black 35 parts; paraffin oil 30 parts; silane coupling agent 10 parts; zinc oxide 8 parts; petroleum resin 2 parts; 2-mercaptobenzimidazole 6 parts; sulfur 2 parts; accelerator 3.5 parts;

[0067] The preparation method of the modified ethylene-propylene-diene rubber is the same as that in Example 2.

[0068] The silane coupling agent is a mixture of silane coupling agent Si-69, γ-(methacryloyloxy)propyltrimethylsilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxy silane in a mass ratio of 2:1:1.

[0069] The soft carbon black is N550 and N660 in a mass ratio of 1:1.

[0070] The accelerator is tetraethylthiuram disulfide and benzothiazole disulfide in a mass ratio of 2:1.

[0071] The preparation method of the run-flat inner tube rubber composition is the same as that in Example 1.

[0072] In order to further illustrate the beneficial effects of the present application, due to the limited space, only Example 4 is taken as an example to construct the following comparative example.

[0073] Comparative Example 1

[0074] In the present comparative example, the modified EPDM is replaced by equal amount of butyl rubber, and the rest of the conditions are the same as in Example 4.

[0075] Comparative Example 2

[0076] In the present comparative example, the modified EPDM is replaced by equal amount of EPDM, and the rest of the conditions are the same as in Example 4.

[0077] Comparative Example 3

[0078] In the present comparative example, the γ-(methacryloyloxy)propyltrimethylsilane is replaced by equal amount of N-(β-aminoethyl)-γ-aminopropyltrimethoxy silane, and the rest of the conditions are the same as in Example 4.

[0079] Comparative Example 4

[0080] In the present comparative example, the N-(β-aminoethyl)-γ-aminopropyltrimethoxy silane is replaced by equal amount of γ-(methacryloyloxy)propyltrimethylsilane, and the rest of the conditions are the same as in Example 4.

[0081] Comparative Example 5

[0082] In the present comparative example, the silane coupling agent is a mixture of γ-(methacryloyloxy)propyltrimethylsilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxy silane in the mass ratio of 1:1, and the rest of the conditions are the same as in Example 4.

[0083] Comparative Example 6

[0084] In the present comparative example, the silane coupling agent is silane coupling agent Si-69, and the rest of the conditions are the same as in Example 4.

[0085] Comparative Example 7

[0086] In the present comparative example, the run-flat inner tube rubber composition is composed of the following components in parts by weight: butyl rubber 90 parts; modified EPDM 10 parts; polyester nanofiber 7 parts; soft carbon black 20 parts; paraffin oil 18 parts; silane coupling agent 6 parts; zinc oxide 30 parts; petroleum resin 3 parts; 2-mercaptobenzimidazole 6 parts; sulfur 2 parts; accelerator 4.5 parts; and the rest of the conditions are the same as in Example 4.

[0087] Comparative Example 8

[0088] In the present comparative example, the soft carbon black is N550, and the rest of the conditions are the same as in Example 4.

[0089] Comparative Example 9

[0090] In the present comparative example, the soft carbon black is N660, and the rest of the conditions are the same as in Example 4.

[0091] Comparative Example 10

[0092] In this comparative example, the accelerator is tetraethylthiuram disulfide, and the other conditions are the same as those in Example 4.

[0093] Comparative Example 11

[0094] In this comparative example, the accelerator is benzothiazyl disulfide, and the other conditions are the same as those in Example 4.

[0095] The compositions prepared in Examples 1-6 and Comparative Examples 1-11 were tested for performance according to the requirements of GB / T 519-2017 Tire Physical Property Test Methods and GB / T 7036.1-2009 Tire Inner Tube Part 1 Automobile Tire Inner Tube, and the test results are shown in Tables 1-3.

[0096] Table 1

[0097]

[0098] As shown in Table 1 above, the composition of the present application has high M300 modulus of elongation, lower permanent set and hot tensile permanent set, indicating that the composition of the present application has higher elasticity and the ability to be used multiple times after being heated. At the same time, the air standing test and air inflation test data can reflect that the present application has excellent air retention and inflation stability.

[0099] Table 2

[0100]

[0101] As shown in Table 2 above, the performance of pure butyl rubber (Comparative Example 1) is lower than that of the composition of the present application; after adding ethylene-propylene-diene rubber (Comparative Example 2), the performance is improved, but the present application further improves the performance of the composition by modifying the ethylene-propylene-diene rubber.

[0102] After modifying the formula of the silane coupling agent in the composition of the present application (Comparative Examples 3-6), the performance of the prepared composition is reduced, proving that the specific formula of the silane coupling agent in the present application can greatly improve the mechanical properties of the composition.

[0103] Changing the ratio of butyl rubber and modified ethylene-propylene-diene rubber to 9:1 (Comparative Example 7) also reduces the performance.

[0104] Table 3

[0105]

[0106] As shown in Table 3, the specific combination of soft carbon black and accelerator in the present application can improve the mechanical properties of the material to a certain extent.

[0107] In conclusion, the application can greatly improve the air retention and inflation stability of the composition by modifying the ethylene-propylene-diene rubber, limiting the proportion of the butyl rubber, and limiting the substances and the proportion of the silane coupling agent, soft carbon black, accelerator and the like, solves the technical problems that the inner tube is easy to deform, is easy to expand during repeated use, the pleat thin point is easy to damage after assembly, and affects the driving safety of the vehicle, and improves the service life and safety performance of the inner tube.

[0108] The above is the preferred embodiment of the application, and for those skilled in the art, some improvements and refinements can be made without departing from the principles of the application, which should be considered within the protection scope of the application.

Claims

1. A run-flat inner tube rubber composition characterized by, The butyl rubber and the modified ethylene-propylene-diene rubber are mixed in a weight ratio of 1:1-5:

1. The amount of the silane coupling agent is 0.7-7.4% of the total weight of the butyl rubber and the modified ethylene-propylene-diene rubber. The diameter of the polyester nanofiber is 400-700nm, and the length is less than 1mm. The silane coupling agent is a mixture of silane coupling agent Si-69, γ-(methacryloyloxy)propyltrimethylsilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxy silane in a mass ratio of 2:1:

1. The modified ethylene-propylene-diene rubber is prepared by mixing the ethylene-propylene-diene rubber and the vinyl silicone rubber uniformly on a mixing mill, with a front roller temperature of 100-130 ℃, a rear roller temperature of 80-95 ℃, and a mixing time of 3-5min. The amount of the vinyl silicone rubber is 1-3% of the mass of the ethylene-propylene-diene rubber. The ethylene-propylene-diene rubber has an ethylene content of more than 50% and a Mooney viscosity of more than 40 at 125 ℃. The soft carbon black is N550 and N660 in a mass ratio of 1:

1. The accelerator is a mixture of tetraethylthiuram disulfide and benzothiazole disulfide in a mass ratio of 2:

1. The activator is zinc oxide, the antioxidant is 2-mercaptobenzimidazole, and the vulcanizing agent is sulfur.

2. The anti-blooming inner tube rubber composition according to claim 1, characterized in that, The method comprises the following steps:

3. The method for producing a blowout-proof inner tube rubber composition according to claim 1 or 2, characterized by, Step 1: weigh each raw material; Step 2: put the butyl rubber, the modified ethylene-propylene-diene rubber, the polyester nanofiber, the activator, the petroleum resin and the antioxidant into a mixing mill, and mix at a speed of 20-45 revolutions per minute for 20-45 seconds; Step 3: put the soft carbon black and the silane coupling agent into the mixing mill, and mix at a speed of 15-40 revolutions per minute for 20-45 seconds; Step 4: add the paraffin oil into the mixing mill, and mix at a speed of 20-45 revolutions per minute until the temperature reaches 150-180 ℃, then discharge to obtain a masterbatch; Step 5: put the masterbatch, the accelerator and the vulcanizing agent into the mixing mill, and mix at a speed of 15-50 revolutions per minute until the temperature reaches 85-135 ℃, then discharge. ​

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