A kind of preparation method for the oligomer that is used to improve the anti-wet performance of rubber

Abstract

The invention relates to a preparation method of an oligomer for improving the wet skid resistance of rubber, and belongs to the technical field of rubber composition additives. In the synthetic process of the specific oligomer provided by the present invention, take clay and sulfuric acid as catalyst system, adopt the method for forward dripping or reverse dripping to synthesize α-methylstyrene oligomer, or the activity of specific kind Using clay as a catalyst, α-methylstyrene oligomers were synthesized by bulk polymerization. The yields of the three preparation methods of α-methylstyrene oligomers provided in the present invention are high, all as high as more than 80%, and when used as rubber composition additives, the wet skid resistance of rubber can be significantly improved; and the used Catalysts and solvents can be recycled, greatly reducing costs and environmental pressure.

Description

technical field [0001] The application relates to a rubber composition additive, in particular to a preparation method of an oligomer used to improve the wet skid resistance of rubber. Background technique [0002] Poly α-methylstyrene resin referred to as PAMS resin, white solid, commonly used as processing aids, adhesives, modifiers and reinforcing agents for extrusion and molding; in addition, it also has weather resistance, electrical insulation, anti- Thermal stability and the role of ultraviolet light absorbers have a wide range of uses in the chemical industry. [0003] At present, there are not too many reports about the preparation methods of poly-α-methylstyrene resins. The commonly used methods in the published literature reports include cationic polymerization and anionic polymerization. The initiation system of cationic polymerization includes solid acid such as clay or ion exchange resin or liquid strong acid and medium strong acid such as sulfuric acid or pho...

AI Technical Summary

Problems solved by technology

The initiation system of cationic polymerization includes solid acid such as clay or ion exchange resin or liquid strong acid and medium strong acid such as sulfuric acid or phosphoric acid. This kind of process generally has the problem of harsh reaction conditions, complex process and difficult control. If strong inorganic acid such as sulfuric acid is used , there will also be disadvantages such as polluting the environment, corroding equipment, and difficult post-processing of products; n-butyllithium is commonly used as an initiator in anionic polymerization, but the process conditions of this method are very complicated, and the raw materials and solvents must be strictly dewatered, and inert gas Rectification under protection, the reaction process also needs gas protection, so it is not suitable for large-scale industrial production

[0004] Patent CN1751071A discloses a method for preparing poly-α-methylstyrene by anionic polymerization of α-methylstyrene monomer. The method uses sec-butyllithium as a catalyst and anhydrous tetrahydrofuran as a solvent. The conversion rate of the reaction is 91%, the number average molar mass (Mn) reaches 312000g·mol -1 , the polydispersity index is 1.06, but this method needs to be carried out in the presence of argon, stirred at -25 ° C for 24 hours, in addition, after the reaction needs to be dissolved in methanol, filtered and dried under vacuum at 40 ° C, Therefore, the reaction conditions of this method are relatively severe, and the requirements for equipment are relatively high, so it is not suitable for industrial production, and the poly-alpha-methylstyrene resin prepared by this method has a high molecular weight and cannot be used as an additive for rubber compositions.

[0005] Patent CN103897087B discloses a cationic polymerization method of α-methylstyrene / styrene copolymer. The polymerization method prepares methylstyrene / styrene copolymer with moderate softening point and glass transition temperature and high reaction yield And efficiency is also higher, but this method needs to adopt semi-continuous feeding method to feed in the reaction preparation process, and step is complicated, is not easy to control, and reaction initiation system is complicated, needs to adopt boron trifluoride etherate complex, ethanol, anhydrous phosphoric acid and Four compounds of phenetole, meanwhile, the molecular weight of the final product obtained by this reaction is on the low side

[0006] Existing patents such as CN102399311A etc. all need to include initiator, Lewis acid and additives in the initiation system of the cationic polymer involved, the preparation polymer molecular weight is difficult to control, the yield is low, the cost is high, and the molecular weight is all in 10 4 Above, cannot be used as an additive for rubber compositions

[0007] In the article "Synthesis of α-methylstyrene linear oligomers catalyzed by clay" published on Volume 21 of "Macromolecular Materials Science and Engineering", it is mentioned that clay is used as a catalyst and α-methylstyrene is used as a raw material The oligomer of α-methylstyrene was synthesized, but the yield per pass of the product was only 58.5%, the yield was low, and the document did not mention the prepared α-methylstyrene oligomer as rubber combination Related uses of additives in substances

[0008] In summary, in the cationic polymerization method of vinyl monomers involved in the prior art, the initiation system involved is relatively complicated, the reaction is not easy to control, the molecular weight of the prepared polymer is high, or the yield of the prepared product is low and the cost is high. Not conducive to industrial use

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