CN103627055B - Utilize the method that modified microcrystalline cellulose prepares tire tread glue - Google Patents

Abstract

The invention discloses a method for preparing tire tread rubber by using modified microcrystalline cellulose. The steps include: 1. Using functional ionic liquid to modify the microcrystalline cellulose; 2. Applying the modified microcrystalline cellulose to In the reinforced tread rubber process, through the conventional mixing process, the modified microcrystalline cellulose is partially replaced with white carbon black to obtain the mixed rubber; the mixed rubber is vulcanized at 130‑180 °C according to the normal curing time of the process After shaping, vulcanized rubber can be obtained. The present invention uses functional ionic liquid (containing double bond, rubber accelerator or vulcanization group, etc.) The interaction of carbon black also limits the formation of silica network structure, which can improve the strength of tread rubber when applied to tire tread rubber, significantly improve the wet skid resistance of tread rubber, and reduce the rolling resistance of tires at the same time. The preparation process is simple and there is no environmental pollution.

Description

Method for preparing tire tread rubber by using modified microcrystalline cellulose

technical field

The invention relates to a preparation process of tire tread rubber, in particular to a method for preparing tire tread rubber by using modified microcrystalline cellulose.

Background technique

Carbon black and white carbon black are high-efficiency reinforcing agents in the rubber industry, and they have an irreplaceable position in rubber reinforcement. However, there are the following problems in the process of processing and using carbon black: ①The processing pollution is serious, carbon black is easy to fly during production, storage and transportation, and when it is added to rubber, even if it is an internal mixer, it is inevitable to damage the health of operators; ② Long processing time and high energy consumption; ③ High dependence on oil. Carbon black is a petrochemical product, and its continuous large-scale consumption is bound to be useless to alleviate the growing shortage of petroleum resources; ④The density of carbon black is high, so that the density of vulcanized rubber is significantly increased, which to a certain extent damages the light weight of polymer materials. Important characteristic that increases the volume cost of rubber products.

Cellulose is a natural polymer material synthesized by plants through photosynthesis. It widely exists in plants, animals and bacteria. The annual cellulose produced in nature is as high as 10 ¹⁰ to 10 ¹¹ tons. Natural cellulose can be prepared into various regenerated cellulose short fibers after regeneration. As a resource-rich renewable and degradable short fiber, if it can be applied to the reinforcement of rubber materials, it will inject new vitality into the development of low-cost, high-performance, and degradable rubber-based composite materials industry.

In recent years, the application of microcrystalline cellulose as a natural polymer in rubber reinforcement research and high-performance tires has attracted widespread attention. At present, in the rubber industry, there are two most commonly used methods to improve microcrystalline cellulose in the rubber matrix, one is adding surface modifiers, and the other is surface chemical grafting. Among them, the surface chemical grafting method has a better effect, but generally the reaction conditions are relatively harsh, the treatment process is relatively cumbersome, and the production cost is relatively high. Adding surface modifiers is a simple and convenient method. At present, small molecular compounds such as silane coupling agents, titanate coupling agents, and surfactants are commonly used to treat microcrystalline cellulose. These small molecular compounds can react with the hydroxyl groups on the surface of silica. Generally, pretreatment of silica is required, and small molecular substances are released, causing harm to the environment and operators.

At present, in the polymer industry, there are many methods for modifying microcrystalline cellulose. Chinese patent (patent number 03114288.5) adds hydrophilic colloid to the water dispersion medium of nano-microcrystalline cellulose and uniformly disperses it with ultrasonic waves, and then dries, Pulverize to prepare water-dispersible nano-microcrystalline cellulose. US Patent (Patent No. 3,539,365) discloses adding hydroxymethyl cellulose to ultrafine cellulose microcrystals (with a particle size as small as micron) by blending to overcome the problem of surface hydrogen bonding of ultrafine cellulose microcrystals. The reunion happened. Chinese patent (Patent No. 03126825.0, Application No. 201210156331.5) in a liquid dispersion medium, under the action of a catalyst, reacts ultrafine and nano-microcrystalline cellulose with an esterification liquid to obtain surface esterification-modified microcrystalline cellulose. Chinese patent (application number 201110333820.9) first uses anhydrous dimethyl sulfoxide to swell the dried microcrystalline cellulose, then uses thionyl chloride for nano-treatment, and finally introduces ammonia gas for modification. A stable nanocellulose suspension was obtained, and finally the carbonylated modified nanocellulose was obtained by freeze-drying. Chinese patent (Patent No. 200810219532.9) first grafts microcrystalline cellulose on the surface, and then uses traditional rubber processing technology to mix the obtained modified microcrystalline cellulose with rubber to prepare rubber/modified microcrystalline fiber The composite material has good mechanical properties. Chinese patent (Application No. 201010522126.7, Application No. 201010522109.3) mixes nano-microcrystalline cellulose and latex first, then adds it to natural latex, and dries to obtain a nano-microcrystalline cellulose/natural rubber mixture, and then adds carbon black or white carbon black Mixing to obtain nano-microcrystalline cellulose-reinforced rubber.

In summary, it can be seen that there are still the following problems in the use of microcrystalline cellulose to reinforce rubber:

(1) The surface of microcrystalline cellulose contains a large number of hydroxyl groups, so the interaction between microcrystalline cellulose is strong, and it is difficult to disperse evenly in the rubber matrix, especially when the size of microcrystalline cellulose is reduced from micron to nanometer. The agglomeration phenomenon is more serious, which greatly reduces the reinforcing effect of microcrystalline cellulose.

(2) The surface polarity of microcrystalline cellulose is relatively strong, and the interface bonding with commonly used non-polar diene rubber is poor, and the interface bonding strength is weak, which also reduces the reinforcing effect of microcrystalline cellulose .

(3) In order to improve the dispersion of microcrystalline cellulose, the cellulose must be co-retrograded with natural rubber latex first, and then mixed. The production process is complicated and the cost is high.

Contents of the invention

In order to solve the problems in the prior art, the object of the present invention is to provide a tire tread rubber prepared from modified microcrystalline cellulose with simple process, low cost and good modification effect, which can meet the requirements of high-performance green tires. Methods.

In order to achieve the above object, the technical means adopted in the present invention is: utilize modified microcrystalline cellulose to prepare the method for tire tread rubber, and its steps comprise:

1. Use functional ionic liquid to modify microcrystalline cellulose: first add ionic liquid, deionized water and microcrystalline cellulose into the reactor, stir at 80°C for 3 hours, and then put the product after stirring at 80°C Dry for 12 hours to obtain ionic liquid modified microcrystalline cellulose;

2. Apply the modified microcrystalline cellulose to the reinforcing rubber process: mixing, mixing the base rubber with the ionic liquid modified microcrystalline cellulose in an open mill or internal mixer, and then adding white carbon Black, then add auxiliary materials, add sulfur and accelerator at the end, make a triangular bag for 6 times, and then release the tablet to obtain a mixed rubber. The above mixing starting temperature is 70-100°C, and the mixing speed is 40-70 rpm , the total mixing time is 6-10min; vulcanization and finalization, vulcanization of the mixed rubber at 130-180°C, the vulcanization time is the process positive vulcanization time determined by the vulcanization meter, and the vulcanized rubber can be obtained.

Further, the ionic liquid in the step 1 is an alkyl imidazolium halide salt, wherein the alkyl group is a group containing a double bond, a polysulfide bond or a promoting group, and the anion is Cl- or Br-.

Further, in step 1, ionic liquid: microcrystalline cellulose: deionized water = 1-5: 100: 300.

Further, the particle size of the microcrystalline cellulose in the step 1 is 1-100um.

Further, in the second step, the ratio of microcrystalline cellulose: white carbon black is 5-25: 45-25.

Further, the auxiliary materials in the second step include TBBS (NS), Si-69, zinc oxide, and stearic acid.

The beneficial effects of the present invention are: improving the dispersion of microcrystalline cellulose in the rubber matrix, improving processing performance; improving the interaction between microcrystalline cellulose and rubber matrix; improving the interaction between microcrystalline cellulose and white carbon black, limiting the amount of white carbon black The formation of the network; applied to the tread rubber, can significantly reduce the rolling resistance, and at the same time improve the wet skid resistance of the tread rubber; the preparation process is simple, and there is no environmental pollution.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Figure 1 is a graph showing the dynamic mechanical (DMA) properties of the vulcanized rubber of the present invention.

detailed description

Example 1

Utilize modified microcrystalline cellulose to prepare the method for tire tread rubber, its step comprises:

Using functional ionic liquid to modify microcrystalline cellulose: put 1g of allyl imidazolium chloride ([AMIM]Cl) ionic liquid, 100g of microcrystalline cellulose, and 300g of deionized water in a glass reactor, at 80°C Heating and stirring in a water bath for 3 hours, then drying the above-mentioned product after the stirring in a vacuum oven at 80°C for 12 hours, and cooling to obtain ionic liquid-modified microcrystalline cellulose; wherein the particle size of the microcrystalline cellulose is 20-80um.

Apply the modified microcrystalline cellulose to the reinforcing rubber process: mixing, mixing the base rubber with the ionic liquid modified microcrystalline cellulose in the internal mixer, the mixing starting temperature is 90 ° C, mixing The refining speed was 60 rpm, and then white carbon black was added, including 5 g of ionic liquid modified microcrystalline cellulose, 45 g of white carbon black, 1 g of auxiliary materials TBBS (NS), 3.6 g of Si-69, 3 g of zinc oxide, hard Fatty acid 1g, finally add sulfur 1.76g and accelerator DPG 1g, thin pass 6 times on the open mill, make a triangular bag and then remove the sheet to obtain a mixed rubber. The above mixing starting temperature is 70-100 ° C 40-70 rpm, the total mixing time is 8 minutes; vulcanization and setting, vulcanization of the mixed rubber at 160 ° C, the vulcanization time is the process positive vulcanization time determined by the vulcanization meter, and the vulcanized rubber can be obtained.

Example 2

Utilize modified microcrystalline cellulose to prepare the method for tire tread rubber, its step comprises:

Using functional ionic liquid to modify microcrystalline cellulose: put 1g of allyl imidazolium chloride ([AMIM]Cl) ionic liquid, 100g of microcrystalline cellulose, and 300g of deionized water in a glass reactor, at 80°C Heating and stirring in a water bath for 3 hours, then drying the above-mentioned product after the stirring in a vacuum oven at 80°C for 12 hours, and cooling to obtain ionic liquid-modified microcrystalline cellulose; wherein the particle size of the microcrystalline cellulose is 20-80um.

Apply the modified microcrystalline cellulose to the reinforcing rubber process: mixing, mixing the base rubber with the ionic liquid modified microcrystalline cellulose in the internal mixer, the mixing starting temperature is 90 ° C, mixing The refining speed was 60 rpm, and then white carbon black was added, including 10 g of ionic liquid modified microcrystalline cellulose, 40 g of white carbon black, 1 g of auxiliary materials TBBS (NS), 3.2 g of Si-693.2 g, 3 g of zinc oxide, hard Fatty acid 1g, finally add sulfur 1.76g and accelerator DPG 1g, thin pass 6 times on the open mill, make a triangular bag and then remove the sheet to obtain a mixed rubber. The above mixing starting temperature is 70-100 ° C 40-70 rpm, the total mixing time is 8 minutes; vulcanization and setting, vulcanization of the mixed rubber at 160 ° C, the vulcanization time is the process positive vulcanization time determined by the vulcanization meter, and the vulcanized rubber can be obtained.

Example 3

This example is a comparative example of Example 1, which differs from Example 1 in that the added microcrystalline cellulose is unmodified microcrystalline cellulose, and the added quality is the same.

Example 4

This example is a comparative example of Example 2, which differs from Example 2 in that the added microcrystalline cellulose is unmodified microcrystalline cellulose, and the added quality is the same.

Example 5

This embodiment is a comparative example, wherein adding white carbon black is 50g, does not add microcrystalline cellulose, added Si-69 4g,

Sulfur 1.78g.

The physical and mechanical properties of the vulcanizates obtained in the above five examples are shown in the table below.

The above experimental data show that after ionic liquid modified cellulose replaces 5phr silica, the physical and mechanical properties of the vulcanizate are greatly improved, while unmodified microcrystalline cellulose replaces 5phr silica, the vulcanizate Decreased physical and mechanical properties. The dynamic properties of the vulcanizate are shown in Figure 1. It can be seen from Figure 1 that the vulcanized rubber containing ionic liquid modified microcrystalline cellulose has a higher tanδ value at 0°C, but a lower tanδ value at 60°C, indicating that the rubber compound has good wet skid resistance, and at the same time The advantage of low rolling resistance.

Ionic liquids (ionic liquids) have a strong interaction with cellulose, and can even partially dissolve cellulose. Moreover, the ionic liquid can also have a strong interaction with carbon black through π-π bonds, and with white carbon black through hydroxyl groups. The present invention utilizes the functional ionic liquid (containing double bonds, polysulfide bonds or accelerators, etc.) that can chemically interact with the rubber matrix as a modifier, and can closely combine the microcrystalline cellulose-rubber matrix-reinforcing filler, Form a firm interfacial bond, and have significant reinforcement and other modification effects on rubber. Based on the strong interaction between imidazole ionic liquid and cellulose, the present invention utilizes functional ionic liquid (containing double bonds, polysulfide bonds or promoting groups, etc.) to modify microcrystalline cellulose, which can effectively prevent the agglomeration of cellulose, It can also improve the interaction between microcrystalline cellulose and rubber. The application of this technology in tread rubber can endow the rubber with the following excellent characteristics:

① Improve the dispersion of microcrystalline cellulose in the rubber matrix and improve the processing performance.

② Improve the interaction of microcrystalline cellulose rubber matrix.

③ Improve the interaction between microcrystalline cellulose, silica and carbon black, and break the network of carbon black and silica.

④ Applied with tread rubber, it can significantly improve the wet skid resistance of the tread rubber and reduce the rolling resistance of the tire at the same time.

⑤ The preparation process is simple, and the microcrystalline cellulose can be treated in situ during the rubber processing process by using a pretreatment method.

In this embodiment, the ionic liquid aqueous solution is used to pretreat the microcrystalline cellulose, and the functional ionic liquid can also be directly added in the rubber processing process to treat the microcrystalline cellulose in situ during the rubber processing process. These two processes have the characteristics of remarkable modification effect, simple process, green and pollution-free. Within the technical scope disclosed in the present invention, skilled persons can easily think of changes or substitutions, and all should be covered within the protection scope of the present invention.

Claims (5)

1. utilize the method that modified microcrystalline cellulose prepares tire tread glue, it is characterised in that step includes:

One, functional ionic liquids modified microcrystalline cellulose is utilized: first ionic liquid, deionized water and microcrystalline Cellulose are added Entering in reactor, stir 3h at 80 DEG C, the product after then stirring being terminated is dried 12h at 80 DEG C, is obtained ionic liquid Modified microcrystalline cellulose；

Two, modified microcrystalline Cellulose is applied in reinforced rubber technique: mixing, in mill or banbury by matrix rubber Glue is the most mixing with modified microcrystalline Cellulose, is subsequently adding white carbon, adds adjuvant, finally adds sulfur and accelerator, thin Logical beat bottom sheet after triangle bag 6 times, obtain elastomeric compound, above-mentioned mixing initial temperature is 70-100 DEG C, mixing rotating speed 40-70 turn/ Min, mixing total time is 6-10min；Sulfuration is shaped, is vulcanized by elastomeric compound 130-180 DEG C, and cure time is by vulcameter The technique sulfurizing time determined, i.e. can get vulcanizate；

In described step one, ionic liquid: microcrystalline Cellulose: mass ratio=1 of deionized water～5: 100: 300.

The method utilizing modified microcrystalline cellulose to prepare tire tread glue the most according to claim 1, it is characterised in that: institute Stating the ionic liquid in step one is alkyl imidazole halogen, and wherein alkyl is double bond containing group, and anion is Cl^-, Br^-。

The method utilizing modified microcrystalline cellulose to prepare tire tread glue the most according to claim 1, it is characterised in that: institute Stating the particle diameter of microcrystalline Cellulose in step one is 1-100um.

The method utilizing modified microcrystalline cellulose to prepare tire tread glue the most according to claim 1, it is characterised in that: institute State the adjuvant in step 2 and include TBBS, Si-69, zinc oxide, stearic acid.

The method utilizing modified microcrystalline cellulose to prepare tire tread glue the most according to claim 1, it is characterised in that: institute State microcrystalline Cellulose in step 2: the mass ratio of white carbon is 5～25: 45～25.