High-strength tear-resistant automobile inflating valve rubber material and preparation method thereof

Abstract

The invention discloses a high-strength tear-resistant automobile inflating valve rubber material and a preparation method thereof. The high-strength tear-resistant automobile inflating valve rubber material comprises the following raw materials in percentage by weight: 16-32% of natural rubber, 20-40% of butadiene styrene rubber, 25-30% of a reinforcing filler, 4-10% of a plasticizing softener, 1-4% of an active agent, 6-8% of other processing aids and 2-4% of a vulcanizing agent. After the formula is improved, the use amount of the natural rubber in the raw materials is increased, and the kaolin is used for replacing white carbon black in the original formula, so that the properties in all aspects are remarkably improved, and the produced wheel belt product is higher in tensile strength, can meet various use scenes and also can meet higher and higher outdoor economic requirements.

Description

Technical Field

[0001] This invention relates to the technical field of automotive valve stems, specifically to a high-strength tear-resistant automotive valve stem rubber material and its preparation method. Background Technology

[0002] The automotive valve stem is a key component for tire inflation and deflation. Automotive valve stems are generally made of two materials: rubber or metal. When rubber is used, natural rubber and EPDM rubber are commonly used as raw materials. However, with the rapid development of China's new energy vehicle industry, valve stems made from natural rubber and EPDM rubber have fallen below the required tear resistance of 500%, limiting their service life and performance in high-intensity applications. This has led to the development of valve stem rubber materials, such as those disclosed in patent application number 201310397127.7. However, these materials use EPDM rubber, which is relatively expensive, placing a significant cost burden on valve stem manufacturers. Furthermore, their tear resistance is poor. Therefore, developing a cost-effective automotive valve stem rubber material with higher tear resistance is crucial. Summary of the Invention

[0003] The purpose of this invention is to provide a high-strength tear-resistant automotive valve stem rubber material and its preparation method to solve the problems of poor tear resistance and high cost of existing automotive valve stem rubber materials mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-strength tear-resistant automotive valve stem rubber material, comprising the following raw materials in weight percentages: 16%-32% natural rubber, 20%-40% styrene-butadiene rubber, 25%-30% reinforcing filler, 4%-10% plasticizer and softener, 1%-4% activator, 6%-8% other processing aids and 3%-4% vulcanizing agent.

[0005] In some embodiments of the present invention, the activator is a mixture of zinc oxide and stearic acid in a weight ratio of 6:1.

[0006] In some embodiments of the present invention, the processing aid comprises 0.5-0.55% by weight of microcrystalline wax, 1.6-1.65% of C5 resin, 1-1.06% of Si69-50, 1-1.60% of RS binder, and 1.5-1.95% of antioxidant, accounting for 1% of the weight of the raw materials.

[0007] In some embodiments of the present invention, the reinforcing agent is high abrasion-resistant carbon black.

[0008] In some embodiments of the present invention, the plasticizer is a naphthenic oil.

[0009] The application further discloses a preparation method of the high-strength tear-resistant automobile valve rubber material. S1, first open the pressurized rubber kneader, set the rotating speed: 32 revolutions per minute, plasticize the natural rubber in the above formula to the plasticized rubber with a Mooney value of 60, and cool the plasticized rubber for standby, and the plasticizing time is 12 minutes; S2, water cooling is given to the internal mixer, the working chamber temperature is controlled to be less than 120 DEG C, the natural rubber and the styrene-butadiene rubber are put into the internal mixer for internal mixing, the internal mixing time is 1 minute, then the active agent, the plastic softening agent and the reinforcing filler in the formula are put into the internal mixer for internal mixing, the internal mixing time is 10-11 minutes, the glue temperature is controlled to be less than 120 DEG C, the glue is discharged, then the masterbatch is obtained by sheeting and cooling on the open mill; S3, the open mill is water cooled, the roller spacing is adjusted to the scale 2, the open mill roller temperature is controlled to be less than 70 DEG C, the masterbatch is put into the open mill, the vulcanizing agent in the formula is uniformly added and mixed for 3 minutes, the roller spacing is adjusted to the scale 0, the glue is thinly passed through the open mill for 3 times, then the sheeting is carried out on the open mill, and the high-strength tire rubber material is obtained by placing in a constant-temperature cold storage for more than 24 hours.

[0010] Compared with the prior art, the application has the beneficial effects that: after the formula is improved, the styrene-butadiene rubber is used to replace the ethylene-propylene-diene rubber in the raw materials at a certain proportion, and other specific reinforcing fillers, plastic softening agents, active agents, processing aids and vulcanizing agents are combined, so that the tensile strength and elongation at break of the product are greatly improved, and the cost is reduced, which makes the tire adapt to a more extensive environment. DETAILED DESCRIPTION

[0011] The following is a clear and complete description of the technical solutions in the embodiments of the application, and all other embodiments obtained by those skilled in the art without creative labor based on the embodiments in the application belong to the scope of protection of the application.

[0012] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more features. In the description of the application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0013] Example 1 The high-strength tear-resistant automobile valve rubber material disclosed in the present example comprises raw materials in the following weight percentages: natural rubber 16%-32%, styrene-butadiene rubber 20%-40%, reinforcing filler 25%-30%, plastic softener 4%-10%, active agent 1%-4%, other processing aids 6%-8%, and vulcanizing agent 3%-4%.

[0014] In some embodiments of the present application, the activating agent is a mixture of both zinc oxide and stearic acid in a 6:1 weight ratio.

[0015] In some embodiments of the present application, the processing aid comprises 0.5-0.55% of microcrystalline wax, 1.6-1.65% of C5 resin, 1-1.06% of Si69-50, 1-1.60% of RS adhesive, and 1.5-1.95% of anti-aging agent, by weight percentage of the raw materials.

[0016] In some embodiments of the present application, the reinforcing agent is high-wear-resistant carbon black.

[0017] In some embodiments of the present application, the plasticizer is naphthenic oil.

[0018] The present embodiment also discloses a preparation method of a high-strength tear-resistant automobile valve rubber material, and the specific steps are as follows: S1, first open the pressurized rubber kneader, set the speed: 32 rpm, plasticize the natural rubber in the above formula to a plasticized rubber with a Mooney value of 60, and cool it for standby, the plasticizing time is 12 minutes; S2, cool the internal mixer with water, control the temperature in the working chamber to be <120℃, put the natural rubber and styrene-butadiene rubber into the internal mixer for mixing, the mixing time is 1 minute, then put the active agent, plastic softener, and reinforcing filler in the formula into the internal mixer for mixing, the mixing time is 10-11 minutes, control the temperature of the rubber to be below 120℃, then discharge the rubber, and obtain the masterbatch by sheeting on the open mill and cooling; S3, cool the open mill with water, adjust the roller spacing to scale 2, control the roller temperature of the open mill to be <70℃, put the masterbatch into the open mill, uniformly add the vulcanizing agent in the formula for mixing, the mixing time is 3 minutes, adjust the roller spacing to scale 0, pass the rubber through the open mill for 3 times, then sheet on the open mill, and place in a constant-temperature cold storage for static standing for more than 24 hours, to obtain the high-strength tire rubber material.

[0019] In the present embodiment, the high-strength tear-resistant automobile valve rubber material is prepared from raw materials in the following weight percentages: Rubber raw materials: natural rubber: 31.90%, styrene-butadiene rubber: 21.28% Reinforcing filler: high-wear-resistant carbon black 29.26% Plasticizer softener: 4.26% Activator: 3.72%.

[0020] Other processing aids: 0.53% of microcrystalline wax, 1.6% of C5 resin, 1.06% of Si69-50, 1.60% of RS bonding agent, 1.86% of antioxidant.

[0021] Vulcanizing agent: 1.06% of insoluble sulfur powder, 0.96% of bonding agent RA, and 0.91% of a mixture of N-cyclohexyl-2-benzothiazole sulfenamide and dithiodibenzothiazole in a weight ratio of (12:5).

[0022] Example 2 A high-strength tear-resistant automobile valve rubber material is prepared mainly from the following raw materials in weight percentage: Rubber raw materials: natural rubber: 16.31%, styrene-butadiene rubber: 38.06% Reinforcing filler: high wear-resistant carbon black: 26.09% Plasticizer softener: 5.44% Activator: 3.8%.

[0023] Other processing aids: 0.54% of microcrystalline wax, 1.63% of C5 resin, 1.02% of Si-69, 1.63% of RS bonding agent, 1.91% of antioxidant.

[0024] Vulcanizing agent: 0.77% of insoluble sulfur powder, 0.92% of bonding agent RA, and 1.88% of a mixture of N-cyclohexyl-2-benzothiazole sulfenamide and dithiodibenzothiazole and dithiotetramethylthiuram and tetramethylthiuram disulfide in a weight ratio of (30:10:3:30).

[0025] Preparation method: same as the preparation method in Example 1 above.

[0026] The processing aids include 0.5-0.55% of microcrystalline wax, 1.6-1.65% of C5 resin, 1-1.06% of Si69-50, 1-1.60% of RS bonding agent, and 1.5-1.95% of antioxidant in weight percentage of the raw materials.

[0027] Example 3 A high-strength tear-resistant automobile valve rubber material is prepared mainly from the following raw materials in weight percentage: Natural rubber: 16.18%, styrene-butadiene rubber: 37.78% Reinforcing filler: high wear-resistant carbon black: 25.9% Plasticizer softener: 6.48% Active agent: 3.78%.

[0028] Other processing aids: 0.54% microcrystalline wax, 1.62% C5 resin, 1.08% Si-69, 1.62% RS adhesive, 1.89% antioxidant.

[0029] Vulcanizing agent: 0.54% insoluble sulfur powder, 0.97% adhesive RA, and 1.62% mixture of N-cyclohexyl-2-benzothiazole sulfenamide and tetramethylthiuram disulfide (1:1) by weight.

[0030] Preparation method: same as the preparation method in Example 1 above Comparative Example 1 The existing automobile air valve rubber material is mainly prepared from the following raw materials in the following weight percentages: Natural rubber: 38.19%, ternary ethylene-propylene rubber 4045: 9.55% Filler: high wear-resistant carbon black: 23.87%, white carbon black: 5.73% Plastic softener: 8.59% Active agent: 5.1%.

[0031] Other aids: 1.43% C5 resin, 0.95% RS adhesive, 3.1% antioxidant, 1.1% dispersant.

[0032] Vulcanizing agent: 0.95% insoluble sulfur powder, 0.72% adhesive RA, and 0.71% mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole in a weight ratio of 4:1.

[0033] The preparation process steps are as follows: Open the pressurized rubber kneader, set the speed: 32 rpm, plasticize the natural rubber in the above formula to a plasticized rubber with a Mooney value of 60, cool and wait for use, plasticizing time 12 minutes. Cool the internal mixer with water, control the working chamber temperature < 120℃, put the plasticized rubber into the internal mixer for mixing, mixing time 1 minute, then put the active agent, plastic softener, reinforcing agent in the formula into the internal mixer for mixing, mixing time 10-11 minutes, control the rubber temperature below 120℃, then discharge the rubber, then roll out the sheet on the open mill, cool to obtain the masterbatch; Cool the open mill with water, adjust the roller spacing to scale 2, control the open mill roller temperature < 70℃, put the masterbatch into the open mill, mix evenly with the vulcanizing agent in the formula, mixing time 3 minutes. Adjust the roller spacing to 0 scale, pass the rubber thin 3 times. Then roll out the sheet on the open mill, place in a constant temperature cold storage for 24 hours or more, to obtain the tire rubber material.

[0034] Comparative Example 2 The existing automobile valve rubber material is prepared mainly from the following raw materials in percentage by weight: Natural rubber: 38.1%, ethylene propylene diene monomer 4045: 9.52% Filler: high wear-resistant carbon black: 23.81%, white carbon black: 5.71% Plastic softener: 8.57% Active agent: 5.09%.

[0035] Other auxiliary agents: 1.43% of C5 resin, 0.95% of RS adhesive, 3.09% of antioxidant, 1.1% of dispersant, 0.24% of cobalt salt.

[0036] Vulcanizing agent: 0.95% of insoluble sulfur powder, 0.71% of adhesive RA, and a mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole in a weight ratio of (4:1).

[0037] Preparation method: same as the preparation method in Comparative Example 1 above Comparative Example 3 The existing automobile valve rubber material is prepared mainly from the following raw materials in percentage by weight: Natural rubber: 38.1%, ethylene propylene diene monomer 3092: 9.52% Filler: high wear-resistant carbon black: 23.81%, white carbon black: 5.71% Plastic softener: 8.57% Active agent: 5.09%.

[0038] Other auxiliary agents: 1.43% of C5 resin, 0.95% of RS adhesive, 3.09% of antioxidant, 1.1% of dispersant, 0.24% of cobalt salt.

[0039] Vulcanizing agent: 0.95% of insoluble sulfur powder, 0.71% of adhesive RA, and a mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole in a weight ratio of (4:1).

[0040] Preparation method: same as the preparation method in Comparative Example 1 above Table 1: Test data of trolley wheel belt rubber material products obtained by experiment The results of the above Table 1 show that after mixing natural rubber and styrene-butadiene rubber in a certain proportion, combined with other specific reinforcing fillers, plastic softening agents, active agents, processing aids and vulcanizing agents, the tensile strength and elongation at break of the material of the present application are greatly improved, and the cost is reduced, which makes the tire valve more stable and reliable in high speed and high pressure conditions.

[0041] Therefore, the formula of the present application is improved, and a certain proportion of styrene-butadiene rubber is used to replace the ethylene-propylene-diene rubber in the raw materials, combined with other specific reinforcing fillers, plastic softening agents, active agents, processing aids and vulcanizing agents, so that the tensile strength and elongation at break of the product are greatly improved, and the cost is reduced, which makes the tire adapt to a wider environment.

[0042] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high strength, tear resistant, automotive valve stem tip rubber material, characterized by: The raw materials include natural rubber 16%-32%, styrene-butadiene rubber 20%-40%, reinforcing filler 25%-30%, plastic softener 4%-10%, active agent 1%-4%, other processing aids 6%-8%, and vulcanizing agent 2%-4% by weight percentage.

2. A high strength, tear resistant, automotive valve stem tip rubber material as in claim 1, wherein: The active agent is a mixture of zinc oxide and stearic acid in a weight ratio of 6:

1.

3. A high strength tear resistant automobile valve stem rubber material as claimed in claim 1, wherein: The processing aids include 0.5-0.55% of microcrystalline wax, 1.6-1.65% of C5 resin, 1-1.06% of Si69-50, 1-1.60% of RS adhesive, and 1.5-1.95% of antioxidant by weight percentage of the raw materials.

4. A high strength, tear resistant, automotive valve stem tip rubber material as in claim 1, wherein: The reinforcing agent is high wear-resistant carbon black.

5. A high strength, tear resistant, automotive valve stem tip rubber material as in claim 1, wherein: The plasticizer is naphthenic oil.

6. A process for the preparation of high strength tear resistant automobile valve stem tip rubber material, characterized by, The specific steps are as follows: S1, first open the pressurized rubber kneader, set the speed: 32 rpm, process the natural rubber in the above formula to Mooney plasticized rubber with a plasticity of 60, cool and wait for use, the plasticizing time is 12 minutes; S2, cool the internal mixer, control the working chamber temperature < 120℃, put the plasticized natural rubber and styrene-butadiene rubber into the internal mixer, mix for 1 minute, then put the active agent, plastic softener, and reinforcing filler in the formula into the internal mixer, mix for 10-11 minutes, control the rubber temperature below 120℃, discharge the rubber, then sheet on the open mill, cool to obtain the masterbatch; S3, cool the open mill, adjust the roller spacing to scale 2, control the open mill roller temperature < 70℃, put the masterbatch into the open mill, mix evenly, mix the vulcanizing agent in the formula for 3 minutes, adjust the roller spacing to 0 scale, pass the rubber through the open mill 3 times, then sheet on the open mill, place in the constant temperature cold storage for 24 hours or more, obtain the high-strength tire rubber material.

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