01/12/2022

What is free radical polymerization? types, characteristics, reaction mechanism, and typical methods with examples

1. What is free radical polymerization?

Free radical polymerization is a widely used method for creating polymers from vinyl monomers. free radical polymerization proceeds through a chain reaction mechanism consisting of initiation, propagation, chain transfer, and termination as the elementary steps.  Azo compounds and peroxides are the main commercially used initiators used in free radial polymerization processes.

1-1. Reaction mechanism of free radical polymerization (elementary reactions)

The first reaction, or initiation reaction generates highly active free radicals that react with monomers to generate propagating radicals. Next, in the propagation reaction, these propagating radicals continue to react with the available monomers resulting in the efficient formation of polymers. The termination reaction occurs when the propagating radical polymer undergoes recombination or disproportionation. Chain-transfer reactions occur when the propagating radical reacts with another chemicals species in the system.

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10/03/2020

Radical reaction

It is recently reported that the radical reaction is used for the organic synthesis as a useful method of bond formation.
We have developed various azoic radical initiators, and we apply the process development for the organic synthesis with those unique initiators. We perform the effective and stereoselective reactions by selecting the radical initiators suitable for the reaction condition and/or reaction system of the compound requested from customers.

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10/03/2020

Extra-low temperature reaction

We possess the reactors of 60LSUS and 1000LGL for the range of extra-low temperature. Since each reactor has the cooling system by jacket, there is no worry about contamination. The 1000LGL reactor is multi-plant type dealing with inner temperature from -80℃ to 130℃. In addition, we possess a flow reactor which can perform safer and more characteristical reaction, with which we have succeeded in performing a reaction at extra-low temperature safely and mildly.

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09/03/2020

Photo base generator

Photo base generator (PBG) generates anion (base) upon irradiation of light in the UV range. The technology of anionic UV curing using the base generated from PBG is expected to apply to various applications such as coating, ink, dental material, photoresist, etc. In addition to the originally developed PBGs, we have many variations of PBG co-developed with Arimitsu, an associate professor at Tokyo University of Science, in our lineup.

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09/03/2020

HIVISWAKO MD

HIVISWAKO is a highly safe water-soluble polymer compound conforming to “carboxyvinyl polymer” which is listed in “Japanese Standards of Quasi-drug Ingredients” and “Japanese Pharmaceutical Excipients”. It is known as “Carbomer” in the cosmetic grade and used for various purposes such as thickening, dispersion and emulsifying and so on because it thickens with small addition.

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09/03/2020

Resist materials

In recent years, the level of fine processing for the advanced semiconductor devices proceeds to nanometer range, and mass production of 3Xnm generation with ArF excimer laser has already begun. On the other hand, 2Xnm generation is rapidly being developed. As for the acid generators and polymers used for the advanced photoresist materials, it is required for the quality to be quite high because of the semiconductor refinement to nanometer range.
We can provide the acid generators and polymers with high quality by utilizing the development/manufacturing technology/analytic technology of photoresist materials, which have been accumulated for years. In addition, we have recently reconsidered the quality assurance system as the whole company to respond to high requirements from customers, and we introduced the consistent procedure for quality control and statistic management from the materials to the products. The development of the advanced analytic technologies enabled us to manage the content of trace metals in the order of single digit ppb.

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