Maximize tire performance

Maximize tire performance

soon, as in Europe now in full swing, North America will also rise a "movement" related to silicon oxide reinforced tread compounds. These compounds become very difficult to process because of the incompatibility between silicon oxide reinforcement and traditional tread polymers

since silicon oxide was used as a reinforcing material to improve tire performance, there have been many changes in the mixing and processing of tire compounds. After using silicon oxide reinforcement technology to replace the traditional carbon black reinforcement technology, a very important challenge is to cause many innovative changes in equipment, synthesis methods and hybrid technology. Its goal is to achieve the expected performance improvement of silica reinforced tread composites, so as to reduce the problems caused by the combination with tread rubber due to the difficulty of dispersion. A method that has been neglected until recently may be one of the most cost-effective methods

Rhein chemical company has designed a processing accelerator with unique expression, which is especially used to eliminate the invalid components in order to achieve the appropriate diffusion of silicon oxide, so as to help silicon oxide maximize its favorable factors in tire performance. This paper describes in detail the improvement of processing performance achieved by using this unique product - ge1872 to improve the bonding and diffusion of silicon oxide

background

a few years ago, it was found that silicon oxide reinforced materials were significantly better than traditional carbon black reinforced tread compounds. In addition, it is found that adding a coupling agent (such as tes Alcoa, which has a strong R & D ability PT) makes the chemical combination of silicon oxide and polymer closer, so as to further enhance its performance. In order to achieve the above effect, a unique mixing technology must be used to maximize its diffusion to achieve performance optimization. Silicon oxide reinforced materials, combined with new mixing technology, make the compounds can not be simply processed in the extrusion and molding processes in tire production. Early production shows that zinc soap can significantly reduce Mooney viscosity and improve the extrusion and in mold fluidity of tread compounds, which use silicon oxide as part or all of their reinforcing materials. Some producers mix carbon black and silicon oxide reinforcement to try to achieve the best effect of both. Zinc soap has proved to be an acceptable method to improve the processability of hybrid reinforcement compounds with a higher proportion of carbon black than silicon oxide. For the increasing demand for low rolling resistance, the reinforcement method of tread compounds will be changed to the mixed reinforcement dominated by silicon oxide materials. Today, in Europe, some tire manufacturers have used 100% silicon oxide reinforcements, but found that even though zinc soaps still reduce the viscosity, they do not achieve the required performance characteristics in silicon oxide dominated compounds

in order to develop a better processing accelerator, Rhein chemistry began to define a standard processing accelerator: a "customized" additive that can make a certain rubber compound produce uniform mixing and processing. This additive can improve the mixing, extrusion and molding processes of the compound without adversely affecting the vulcanization characteristics of the compound

with this definition, the question arises: has a real processing accelerator been designed for silicon oxide reinforced tread compounds? Of course, some products have been developed for other applications of silicon oxide reinforced tires, but their vulcanization characteristics are disappointing compared with the data of the same compound without them. Some of these products cannot even reduce the Mooney viscosity to a certain extent to significantly improve the extrusion and molding process of silicon oxide compounds. Generally speaking, processing accelerators can be divided into internal lubricants (homogenizer and viscosity reducer) and external lubricants (wear agents). Previous work tried to use 100% internal lubricant or 100% external lubricant to design a processing accelerator for silicon oxide reinforced compounds, but it proved to have defects. The internal lubricant will interfere with the reaction of filler/polymer, while the external lubricant does not reduce the viscosity enough to facilitate processing. The new product Ge 1872 is specially developed and produced for tread compounds containing silicon oxide. Ge 1872 combines the respective advantages of internal lubricant and external lubricant, and can achieve the required processing improvement value without affecting the filler/polymer reaction. This product not only retains the extrusion and molding processes of silicon oxide reinforced compounds, but also improves the performance characteristics of vulcanized products

objective

the objective is to develop a processing accelerator specifically for improving the extrusion and molding processes of tread compounds while retaining their physical properties. This paper reveals the basic design of a good processing accelerator, discusses the selection of conventional methods, and compares them with the newly developed Ge 1872. This article will also show that GE 1872 can significantly improve the processing operability of silicon oxide reinforced tread compounds after achieving the required performance characteristics

35, 50, 75, paddle hole from below to above φ The experimental data can be distinguished according to the numbers printed around the paddle: compound development

the primary consideration of this project is to select a compound, which must be able to show the best type of processing accelerator for silicon oxide reinforced materials. The selected polymer is a mixture of 75 parts of aromatic oil soluble styrene butadiene rubber and 25 parts of polybutadiene rubber, 80 parts of 100% precipitated silica reinforcement, 37.5 parts of environmentally friendly aromatic oil and 6.4 parts of tespt coupling agent. This project also uses 4 parts of antioxidant/ozone inhibitor package, 2.5 parts of zinc oxide and 1 part of stearic acid. The vulcanization method is relatively simple: 1.7 parts of TBBS, 1.4 parts of sulfur and 2 parts of rubber vulcanization accelerator DPG. Zinc oxide is artificially reduced and carbon black is removed to prevent them from interfering with the activities of a variety of process accelerators being tested. Processing accelerators are added for the first time so that they each show their best effect

the processing accelerator selected in the test is fatty acid mixture, zinc soap mixture and new product Ge 1872. Select 3 portions of each test article to determine their differences in improvement. The mixing step is suggested in the 3-pass system, and in the first two runs, silicon oxide is divided and sulfur is added in the third run. The processing and properties of the resulting compounds were tested. Table 1 shows the detailed formula

rheological property I (rheological value)

Figure 1 shows the rheological value plan of four compounds. Sometimes, when reacting with silicon containing compounds, the modulus of all selected processing accelerators decreases. Compared with other tested processing accelerators, Ge 1872 has higher maximum torque and better vulcanization curve in a limited range. All rheological properties were tested at 160 ℃ for 60 minutes

Figure 1

rheology II (Mooney charring value)

Figure 2, the viscosity of fatty acid processing accelerator and zinc soap is low, but it significantly prolongs the coking time, so that these two products can be used as retarders. Ge 1872 shows that it can reduce the viscosity and minimize the coking change, so that it has better extrusion speed than the test sample without "sacrificing" the vulcanization rate

Figure 2

rheology III (spider runner mold)

we can see from Figure 3 that the excess flow value of Ge 1872 in the spider runner mold is basically the same as that of zinc soap, but much better than the fatty acid mixture. This test once again shows that the use of Ge 1872 can improve the fatty acid mixture and zinc soap products without having a negative impact on the vulcanization rate

Figure 3

physical properties

physical property values (Table 2) are taken from standard strength test pieces and other test samples vulcanized for T90% at 160 ℃. At 100 ℃, the characteristics were also tested after 72 hours of hot air aging. In this method, the longer vulcanization rate of fatty acid and zinc soap products did not deviate from the normal value. The results showed that ge1872 had no loss of physical properties, and the fatty acid and zinc soap products could not reach the value of the tested compound. Compared with the test compound, the aging characteristics of Ge 1872 have been improved, which shows that this new product can be retained, perhaps actually improving the performance of the test product, while also optimizing the extrusion processing and molding processes

100% modulus

one of the main differences between the two conventional processing accelerators and the new product Ge 1872 is the impact on the 100% modulus (Figure 4). Ge 1872 has no change in modulus, while the 100% modulus of fatty acid and zinc soap products has been significantly reduced

Figure 4

dynamic: loss modulus

from Figure 5, we can see the impact of the dynamic effects of different processing accelerators on the shock absorption characteristics of sulfides. This test was carried out in a normal temperature scan, operated in an RPA instrument, and the test object was set to 10% strain and 10Hz. The results show that at high temperature, zinc soap increases the loss modulus, which can take away part of the rolling resistance improvement of normal silicon oxide reinforced tread compounds. Regardless of the temperature, the value of fatty acids is almost the same as that of the test article. Different from the other two processing accelerators, the loss modulus of Ge 1872 is lower than that of the test article in the range of 70 ~ 90 ℃, while when the temperature decreases, its loss modulus is much higher than that of the test article. These records are taken from three portions of feed, and further work is needed to determine whether this trend will produce greater differences. Relying on these new data, by strengthening the wet skid resistance, a novel method to improve the new heel properties of silicon oxide reinforced tread compounds can be produced, and its traditional low rolling resistance can be retained

Figure 5

conclusion

Ge 1872, because of its best balance between internal lubricant and external lubricant, significantly improves the processing characteristics compared with traditional fatty acids and zinc soap processing accelerators, and can retain the performance and dynamic characteristics of silicon oxide reinforced compounds. This new product can match the lower viscosity of fatty acids and zinc soaps and improved in mold fluidity without negative retardation effects, which are shown in rheological records. In the vulcanization performance characteristics, it retains the beneficial influence of silicon oxide reinforced materials, and will not cause the certainty of physical properties. These physical properties are usually used alternately with conventional operation additives and wear resistance to create favorable conditions for low rolling resistance. The change of coupling agent feeding or the better reinforcement design scheme combined with Ge 1872 can further improve the performance of silicon oxide reinforced tires

Table 1

compound 123 4

Buna VSL HM 75 75 75

Buna carbon black 24 25 25 25 25

precipitated silica 80 80 80

tespt 6.4 6.4 6.4

environmental aromatic oil 37.5 37.5 37.5 37.5

anti ozone paraffin 2222

TMQ 111 1

potent antioxidant 111 1 1

zinc oxide 2.5 2.5 2 At the beginning of the test, take a standard weight and hang it lightly on the upper fixture connecting seat, record the pneumatic value displayed by the computer, and calculate the difference with the standard weight. The error should not exceed 1% 52.5

stearic acid 111 1

sulfur 1, and then clamp the other end of the test piece in the same way 4 1.4 1.4 1.4

rubber accelerator TBBS 1.7 1.7 1.7

dpg 2222 2

fatty acid mixture 0 3

ge 187203

zinc soap 0 3

table 2

test article fatty acid mixture zinc soap Ge 1872<