Until a few years ago they had a hold on the upper end of the market. The chinese competitor's quality was unreliable enough that clothing manufacturers were willing to pay a premium to ensure a failed zipper does not trash a garment. That situation has been changing, and chinese companies are offering zippers which are getting used on progressively higher end products.
By releasing a new product with substantial changes and thus patentability they can buy a few decades at the top of the market. I suspect this technology has been in development for a long time, and held back until competitors were threatening the premium traditional zipper market.
Until a few years ago they had a hold on the upper end of the market. The chinese competitor's quality was unreliable enough that clothing manufacturers were willing to pay a premium to ensure a failed zipper does not trash a garment. That situation has been changing, and chinese companies are offering zippers which are getting used on progressively higher end products.
By releasing a new product with substantial changes and thus patentability they can buy a few decades at the top of the market. I suspect this technology has been in development for a long time, and held back until competitors were threatening the premium traditional zipper market.