4 key rubber materials to break the dependence - a record of the development of key technologies for the industrialization of high-performance synthetic rubber

Recently, the "Key Technology of High-performance Synthetic Rubber Industrialization" led by PetroChina passed the comprehensive performance evaluation
of the project.
The project has made major technological breakthroughs in the manufacturing process and formula of tread rubber, innerliner, sidewall rubber and vulcanized capsules, realized the industrial production of four rubber varieties and integrated application demonstration in tires, and broke the dependence
of China's high-performance tire manufacturing on foreign high-end basic rubber raw materials and advanced processing technology.
This will effectively promote the transformation and upgrading of China's synthetic rubber and tire industry from large to strong, and reconstruct the high-quality development base
of China's tire industry chain.

Group innovation joint research

China is the world's largest producer and sales of
synthetic rubber and tires.
In 2017, China's synthetic rubber output reached 3.
55 million tons, accounting for 23.
6% of global production, but high-end products need to be imported, with an annual import volume of 1.
365 million tons
.

The main factor contributing to this situation is the complex manufacturing process of high-end tire rubber and the difficulty of technical development
.
This has affected the technological progress and high-quality development
of the entire domestic high-end tire industry and synthetic rubber industry.

On October 30, 2017, the "Key Technologies for High-performance Synthetic Rubber Industrialization" project kick-off meeting and implementation plan consultation and review meeting was held in Beijing, sounding the "storming trumpet"
for the transformation of the domestic synthetic rubber and tire industry chain.

As the leader, PetroChina handed over this difficult task to Gong Guangbi
, director of the Lanzhou Chemical Research Center of the Petrochemical Research Institute.
From the project application stage, Gong Guangbi focused on the project requirements and focused on major scientific and technological issues
related to the core competitiveness of the industry, the overall independent innovation ability and the national industrial security 。 PetroChina, together with Tsinghua University, Tongji University, Dalian University of Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Yiweiyi Rubber Research Institute, Sailun (Dongying) Tire Co.
, Ltd.
, Zhejiang Xinhui New Materials Co.
, Ltd.
, 7 domestic first-class universities, research institutes and enterprises in the rubber field, relying on five national platforms such as the State Key Laboratory of Polymer Physics and Chemistry, the National Rubber and Tire Engineering Technology Research Center, has established an innovation team
covering the entire industrial chain.

"The scientific research team should overcome the view of the portal, pool the strengths of all families and the strength of the whole country, build a technology platform that can sustainably support and lead industrial development in China through independent innovation, and enhance the competitiveness of products made in China through technological progress, so as to create a healthy industrial 'ecosystem'
for the synthetic rubber and tire industry.
" Gong Guangbi said
.
In order to complete the development and application within the specified time, it is necessary to break the convention, accelerate the speed of scientific research and development, technology update and achievement, and shorten the promotion cycle
from scientific research to technology to market.

In view of the tight time, heavy tasks, many participation, and difficulty in organization and coordination, the project team carried out the whole chain design according to the basic frontier, major common key technologies to application demonstration, adhered to the principle of integrated organization and implementation, and adopted the way of coordinated research and overall promotion of industry, education and research to formulate a complete set of implementation and solutions
.

The four major directions go hand in hand

The project "Key Technologies for the Industrialization of High-Performance Synthetic Rubber" has four topics
.
After the implementation of the project, all cooperation and personnel fully supported the project in view of the difficulties such as the high starting point of the project and the difficulty of theoretical innovation, and created a beautiful landscape
of one "striver" after another.

As far as the topic of "star branched butyl/bromobutyl rubber technology and key equipment" is concerned, under the leadership of technical leaders Wei Xuling and Yan Penghua and Professor Wu Yibo of Beijing Institute of Petrochemical Technology, the research group developed a branching agent with controllable number of branching site structure and quantity, soft segment-hard segment combination, and both grafting and slurry stabilizing functions through theoretical innovation and anionic polymerization method, and overcame the technical problem of preparing star branched butyl rubber by "in situ grafting" method.
Together with the expert team of Ren Jiwen of Zhejiang Xinhui New Materials Co.
, Ltd.
, we jointly designed and built the first set of butyl rubber industrial side line device in China, which provided platform support
for the industrialization of new technologies and new products of star branched butyl rubber.

In view of the extreme working conditions such as high viscosity, large mixing ratio and strong corrosion involved in the bromination process of butyl rubber, the team of Professor Luo Guangsheng of Tsinghua University systematically studied the basic law of "high viscosity-large flow ratio" mixing system in the microchannel, designed and optimized the cross-type and micro-sieve hole mixing structure, proposed the design method of one-dimensional geometric amplification and two-dimensional quantity integration of micro-mixing unit, and the anti-corrosion method of polytetrafluoroethylene microstructure and coating combination, and created a small size, safe and reliable, low maintenance cost butyl rubber bromination, Neutralize industrial microreactors
.
At the same time, they completed the industrialization demonstration of butyl rubber bromination micro-reaction technology, created the world's first set of 10,000-ton bromobutyl rubber micro-chemical production system, bromine utilization rate reached 93%, product quality reached the international high-end product level, and created a precedent
for large-scale industrial application of micro-chemical technology in the field of synthetic rubber.

In recent years, the transformation of the automotive industry has put forward new requirements for the improvement of tire basic materials, especially the transformation of fuel vehicles to new energy vehicles, which requires functional dissolved polystyrene-butadiene rubber, and all domestic use relies on imports
.
In order to realize the independent and controllable of the product as soon as possible, the "functional dissolved polystyrene-butadiene rubber" research group carried out multiple programs at the same time, starting from basic research, and established a synthesis method platform
for functional dissolved polystyrene-butadiene rubber.
They developed the core technology of functional initiator preparation, solved the problems of poor solubility, low initiation efficiency and poor stability of traditional functionalization initiator in hydrocarbon solvents, completed the industrial test of functional dissolved polystyrene-butadiene rubber in the Dushanzi petrochemical dissolved polystyrene-butadiene rubber production unit, and produced 107 tons of industrial products, and the product performance reached the technical level of similar foreign products and filled the domestic gap
.

"Narrowly distributed branched rare earth cis-butadiene rubber" is another high-end product
that needs to be developed in the project.
In May 2018, the research group carried out pilot research
in Dushanzi Petrochemical.
After the hard work of the teams of Changchun Institute of Applied Chemistry, Dushanzi Petrochemical and Petrochemical Institute, the research group developed a single active central rare earth catalyst of neodymium carboxylate, which increased the catalyst activity by more than 20%, increased the polymerization conversion rate to more than 99%, and realized the production demonstration of narrowly distributed branched rare earth cis-butadiene rubber of 32,000 tons/year, forming a stable industrial production technology, and the product performance exceeded the level
of similar foreign products.

Li Bo, leader of the research group of "Industrialization Demonstration of Double B Class Tires and Long-Life Capsules", and researchers from Yiweiyi Rubber Research Institute and Sailun Group proposed the basic principles
of formula design of high-performance tire tread rubber by studying the influence of functionalized dissolved polystyrene-butadiene rubber, rare earth cis-butadiene rubber and silica on rolling resistance and wet slip resistance.
They combined with a complete set of tire manufacturing processes such as wet mixing, low-temperature primary mixing, and electron irradiation pre-vulcanization developed by the research team to realize the regulation
of tire anti-slip performance and rolling resistance.

They also developed the integrated application technology of 3 rubber grades in high-performance tires, and the prepared tire rolling resistance/wet slip resistance reached the EU tire labeling method A/B grade, which was 2~3 grades
higher than the existing domestic tires.
The number of vulcanized capsules prepared by butyl rubber has been used more than 600 times, an increase of more than
38% over the domestic average of 450 times.

Several major breakthroughs were achieved

The completion of the "Key Technology of High-performance Synthetic Rubber Industrialization" project not only promotes the development of domestic high-performance synthetic rubber materials and the technological progress and industrial upgrading of China's tire industry, improves the competitiveness of domestic tires in the international market, but also grasps the "bull's nose" of the high-quality development of the synthetic rubber industry, promotes China's leap to the rubber industry power, and promotes the landing of the national "double carbon" goal
.

The completion of this project has enabled China to form new major technological breakthroughs in the manufacturing process and formula of tread rubber, innerliner, sidewall glue, vulcanized capsule, etc.
, produce core materials urgently needed by the country, realize the industrial production of four rubber varieties and the integrated application demonstration
in tires.
Up to now, the project has achieved 4 theoretical innovations and breakthroughs, 3 breakthroughs in key technologies, 6 innovative products, 3 key equipment innovations, 32 national invention patents, 26 published papers, and 6 revised standards
.

The integrated application demonstration of high-performance synthetic rubber base materials independently developed by the project breaks the dependence of China's high-end tire manufacturing on foreign high-end basic rubber raw materials and advanced processing technology, and increases the average proportion of high-performance synthetic rubber base materials for tires in China by about 15%.

The rolling resistance of the tires reaches class A, and the wet slip resistance of the tires reaches class B, reducing carbon dioxide emissions by about 37.
7 million tons per year.