About Rubber

As the vulcanization of rubber balls tends to be “high temperature and short time”, many new processes tend to adopt continuous and streamlined production modes, and the necessity of anti-reversion is becoming more and more obvious. Effective anti-return measures have been adopted. Was put on the agenda. In this regard, foreign countries take a step forward. Some of these practices can be used as reference, learning and reference in light of our own actual situation.

These measures include:

1. Strictly control the vulcanization process regulations, especially in strict compliance with the specified vulcanization temperature and vulcanization time. At the same time, it is necessary to constantly verify the accuracy and reliability of the various instruments equipped with the vulcanization equipment, and the requirements are not bad.
2. If high temperatures are used in the vulcanization conditions, the use of conventional vulcanization systems to avoid the production of rubber balls should be avoided as much as possible with effective or semi-effective vulcanization systems. The protective system can also be formulated with a heat-resistant anti-aging agent (for example, p-phenylenediamine), which is more effective.
3. Use anti-reversion agent

Anti-reversion agents are counter-agents specifically designed to inhibit reversion. This type of compounding agent was developed in the 1990s to meet the special needs of high temperature short time vulcanization. Because it was published soon, it is difficult to find in the general manual. Functionally, they should belong to the category of heat-resistant antioxidants. However, because it is specially supplied to the vulcanization process, it can also be classified as a processing aid for vulcanization. The amount of anti-reversion agent is generally controlled between 1.5 and 2.0 parts.

Depending on the mechanism of action, they can usually be divided into the following three types: one is multi-functional. In addition to anti-return, it can also improve the mechanical properties of the rubber ball, including the tensile stress, heat resistance and rubber adhesion.

The second is the cross-linking compensation type.

It is characterized in that when the rubber ball is in the post-vulcanization stage or encounters the reversion of the vulcanization, the incoming and outgoing network is a CC bond with excellent thermal stability, instead of the usual polysulfide bond, which can provide carbon without returning. At the same time of carbon cross-linking, the original cross-linking density is maintained to ensure that the mechanical properties are not lowered.

It is characterized in that when the rubber ball is in the post-vulcanization stage or encounters the reversion of the vulcanization, the incoming and outgoing network is a CC bond with excellent thermal stability, instead of the usual polysulfide bond, which can provide carbon without returning. At the same time of carbon cross-linking, the original cross-linking density is maintained to ensure that the mechanical properties are not lowered.

The third is a post-vulcanization stabilizer.

It is characterized in that it can insert a polysulfide bond in the middle of the vulcanization process to form a mixed hybrid bond containing both sulfur and carbon. When the rubber is heated in the post-vulcanization stage or in the future, the hybrid key is automatically stepped
The sulfur atom is removed to form a monosulfide bond. Moreover, this monosulfide bond has greater flexibility and dynamic properties than ordinary monosulfide bonds.