Mitsubishi Chemical Corporation

On December 1, 2021, Mitsubishi Chemical Corporation (MCC; Head office: Chiyoda-ku, Tokyo; President: Masayuki Waga) filed a lawsuit with the Seoul Central District Court in South Korea against TMS Co., Ltd. (TMS), a South Korean manufacturing and sales company of optical clear adhesive sheet, seeking an injunction and compensation for damages associated with manufacturing and sales in South Korea based on the following patent rights.


With regard to MCC’s patent rights in South Korea related to optical clear adhesive sheet (OCA) used as a direct bonding material for smartphones and tablets (Republic of Korea Patent Nos. 1773756, 1975353 and 2233056; collectively, "the Patents, etc."*), the lawsuit seeks an injunction and compensation for damages associated with the manufacture and sale, etc. in South Korea of TMS’s OCA (TM-QN series products, TTC series products, and T5 series products), which MCC ruled as being manufactured and sold by TMS under the MCC patents concerned.


The Patents, etc. relate to OCA that can be cured by ultraviolet light after bonding of the adherend (post-UV-cured OCA). The OCA manufactured and sold by MCC has been widely supported and evaluated by panel manufacturers as the industry's first post-UV-cured OCA, obtained by improving customer yield through the realization of excellent difference absorption, cutting processability and foam resistance.


The post-UV-cured OCA is a proprietary technology MCC has been developing for many years ahead of other companies. MCC has actively invested in and developed businesses to ensure that customers can use it with peace of mind and has also made proactive efforts to protect and utilize its intellectual property rights.


The purpose of this lawsuit is to protect important intellectual property rights that MCC has actively invested in and developed. We believe that this will contribute to the sound development and maintenance of order in the optical materials industry.

MCC will not overlook the manufacture, sale, or utilization of a product through the application of MCC’s patents without its approval and will hold such person or persons liable and take appropriate action anywhere in the world.


* MCC holds a number of other related patents worldwide.

Corporate Communications Div.,
The Mitsubishi Chemical Group
  • TEL:+81-3-6748-7140

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