Yokohama develops hose for “next-generation refrigerants”

Tokyo – Yokohama Rubber Co. Ltd has developed a new hose for use in automotive air-conditioning units, announced the company on 29 April.

The “AC6B-11” hose is compatible for use in car air-conditioners that use the next-generation refrigerant HFO-1234yf, which is mainly being adopted for use in cars in Europe.

Yokohama Rubber has already begun shipments of the new hose to makers of automotive air-conditioning systems, with the hose primarily being installed in air-conditioners for vehicles targeted at the European market.

Automotive air-conditioner hose constructions consist of an outer rubber layer followed by reinforcing threads and an inner rubber layer, the inside of which is coated with a polyamide resin to prevent leakage of the refrigerant.

HFO-1234yf, said YRC, decomposes gradually over a long period of use, releasing an acid in the process. Hoses in use, to date, have been corroded by the release of this acid.

“To solve this problem, Yokohama Rubber mixed an acid acceptor into the polyamide resin to enable it to capture and hold the acid runoff. The resin compound has proven successful in preventing leakage of the refrigerant and the resulting corrosion of the polyamide resin,” added the statement.

The company said it has already received a patent for the technology.