Kolon Group Vice Chairman Lee Kyu-ho, left, and Hyosung Group Vice Chairman Cho Hyun-sang look around exhibition booths during the H2 Mobility + Energy Show 2021 at KINTEX in Goyang, Gyeonggi Province, in this September 2021 file photo. Courtesy of Kolon Group

Hyosung and Kolon have filed lawsuits against each other recently in attempts to take the lead in the global tire cord market amid the growing demand for fabrics used to reinforce tires of electric vehicles (EVs), according to industry officials, Tuesday.

Their recent legal battle came nearly three decades after the two textile firms vied in the 1990s to take control of Capro, Korea's only producer of caprolactam, which is used to make nylon.

Earlier this month, Hyosung Advanced Materials confirmed in its regulatory filing that Kolon Industries filed a lawsuit in the U.S. state of California in late February.

"Kolon asked the U.S. District Court for the Central District of California to permanently ban Hyosung and its employees from infringing on Kolon's patents on aramid-nylon hybrid tire cord and to order Hyosung to compensate for Kolon's legal costs and loss from Hyosung's patent infringements," the regulatory filing read. "We will take measures with our attorney."

The regulatory filing was posted several weeks after Korea's Intellectual Property Trial and Appeal Board decided last month to reject Hyosung's request in 2022 to nullify Kolon's tire cord patents, which were granted in 2015.

"We are considering an appeal against the board's decision," a Hyosung Group official said, claiming that Kolon's technologies are nothing new.

If the case is brought to the court, it could take more than three years for the final ruling to come out.

"We respect the board's fair decision," a Kolon Industries official said. "Based on the board's recognition of our patent's validity, we will proceed with the patent suit in the U.S."

The global demand for tire cord is expected to soar as EVs equipped with batteries are heavier than internal combustion engine vehicles. In particular, hybrid tire cord is regarded as more suitable for EV tires, due to the material's excellent durability.

Given that Kolon has lagged behind Hyosung in market share by a large margin, the former is going all out to catch up with the latter by protecting its patents here and overseas. Hyosung holds 51 percent share in the global tire cord market, while Kolon occupies 15 percent.

There is speculation that the owner families of the two companies may seek reconciliation, considering their close relations.

Earlier this month, Kolon Group Honorary Chairman Lee Woong-yeul visited the funeral altar for the late Hyosung Group Honorary Chairman Cho Suck-rai, who died on March 29. Lee's oldest son, Kolon Group Vice Chairman Lee Kyu-ho, also paid a visit on March 31.

"The late Cho was the star of the textile industry," the Kolon honorary chairman said at that time.

When the incumbent Kolon honorary chairman's father, the late Kolon Group Honorary Chairman Lee Dong-chan, died in 2014, Hyosung Group Chairman Cho Hyun-joon and his youngest brother, Vice Chairman Cho Hyun-sang, also visited the funeral altar for the late Lee on two consecutive days.