Domestic catalysts allow polypropylene to advance to the high-end - Keimocene metal polypropylene catalyst technology development and application project

After ten years of hard research, the polyolefin technology innovation team of China Petroleum and Petrochemical Research Institute completed the project of "Metallocene Polypropylene Catalyst Technology Development and Application" made a major breakthrough, developed metallocene polypropylene catalyst with independent intellectual property rights, and completed industrial application on multiple devices, promoting the high-quality development of
China's polyolefin industry.
The project also recently won the first prize
of technical invention of the Chinese Chemical Industry Society.

The core technology is monopolized by foreign countries

Affected by the global new crown pneumonia epidemic and other factors, the domestic polypropylene market competition is becoming increasingly fierce, the demand growth of traditional polypropylene products is weak, and the market price is approaching the cost line
.
For manufacturers, the only way out is to develop differentiated products and increase the added value
of products.

Traditional polypropylene products are produced with ordinary catalysts, while metallocene polypropylene requires metallocene catalysts
.
Compared with traditional polypropylene products, metallocene polypropylene has the characteristics of narrow relative molecular weight distribution, low melting point, and no formation of soluble short-chain block copolymers, and is mainly used in high-end non-woven fabrics, injection molding, films, fibers and other fields
.
However, the preparation technology and core catalyst of metallocene polypropylene have long been monopolized by foreign companies, and the products basically rely on imports
.

The catalyst was independently developed and successfully developed

Since 2014, the polyolefin technology innovation team of the Petrochemical Research Institute has carried out joint research on metallocene polypropylene products
.
Starting from the catalyst carrier, the project team developed the carrier surface modification technology, which realized the control of the mechanical strength and pore size distribution of the carrier through the heat treatment process, and regulated the surface energy and Lewis acidity of the carrier through the chemical modification of the carrier, so as to improve the catalyst loading effect and promote the catalytic polymerization ability
of the loaded metallocene compound.
The polymer prepared by this technology has good morphology and retains the performance of
the metallocene catalyst with high activity and single active center.

In addition, in response to the development needs of metallocene transparent polypropylene special products, the project team independently designed a new compound structure from the metallocene compound structure, so that the bridge group functional group connects the mixed ligand cyclopentadienyl group and fluorene group, restricts the rotation of the molecular skeleton, and forms a carbon bridged restricted geometric metallocene compound, which is conducive to the selective polymerization of propylene and obtains a catalytic active center
with high interch.

Industrialized products enter the high-end

In 2017, the metallocene polypropylene catalyst PMP-01 independently developed by the project team completed industrial application and produced highly transparent metallocene polypropylene MPP6006
.
This is the first metallocene polypropylene catalyst
successfully applied in industrial application in China.
Since then, PMP-01 catalyst has completed two industrial application tests on the liquid bulk polypropylene device, and developed four transparent metallocene polypropylene grades
.
The polypropylene particles produced by this catalyst have good morphology, high impact resistance, high flexibility and high transparency
.

It is understood that the metallocene polypropylene product can be applied to the preparation
of cast film and biaxially oriented polypropylene film.
Among them, the cast film prepared by the representative grade MPP6006 has good processing performance and can effectively reduce the heat sealing temperature, which is about 20 °C
lower than the heat sealing temperature of the general terpolymer polypropylene.

In addition, transparent metallocene polypropylene produced by PMP-01 catalyst has been applied to medical 3D printing materials, which solves the problems of high printing temperature and odor of
polypropylene materials produced by traditional catalytic systems.
The processing temperature of 3D printing wire made of metallocene polypropylene can be reduced by 20 °C ~ 30 °C, and it also has low odor, low warpage, good dimensional stability and radiation resistance
.
The successful development of medical 3D printing materials has realized the application of metallocene polypropylene in high-end products, showing the potential
of domestic metallocene polypropylene to enter the high-end product market.