The Company monitors the recoverability of goodwill annually or whenever events or changes in circumstances indicate the carrying value may not be recoverable. Purchased intangible assets subject to amortization consist of acquired technology and other intangible assets that include trade names, customer relationships and developed intellectual property (IP) processes.

Acquired technology primarily consists of acquired license rights for patents and know-how obtained from Merck KGaA, BASF and Fujifilm. These intangible assets consist of the following (in thousands):


	December 31,
	2023 (1)			2022
PD-LD, Inc.	$	—		$	1,481
Motorola		—			15,909
Merck KGaA		66,012			—
BASF		95,989			95,989
Fujifilm		109,462			109,462
Other		5,712			5,212
		277,175			228,053
Less: Accumulated amortization		(186,850	)		(189,671	)
Acquired technology, net	$	90,325		$	38,382

(1)

During the year ended December 31, 2023, the gross value and accumulated amortization associated with the PD-LD, Inc. and Motorola patent portfolios have been removed from the table as the underlying patents have reached the end of their useful lives.

Amortization expense related to acquired technology was $14.6 million, $16.0 million and $20.6 million for the years ended December 31, 2023, 2022 and 2021, respectively. Amortization expense is included in amortization of acquired technology and other intangible assets expense line item on the Consolidated Statements of Income and is expected to be $16.8 million in each of the years ending December 31, 2024 and 2025, $12.0 million in the year ending December 31, 2026, $7.2 million in each of the years ending December 2027 and 2028, and $30.3 million in total thereafter.

In April 2023, UDC Ireland entered into a Patent Sale and License Agreement with Merck KGaA. Under this agreement, Merck KGaA sold to UDC Ireland all of its rights, title and interest to over 550 of its owned and licensed OLED-related patents and patent applications in exchange for a cash payment of $66.0 million. The Patent Sale and License Agreement contains customary representations, warranties and covenants of the parties. UDC Ireland recorded the payment of $66.0 million as acquired technology, which is being amortized over a period of 10 years.

On June 28, 2016, UDC Ireland entered into and consummated an IP Transfer Agreement with BASF. Under the IP Transfer Agreement, BASF sold to UDC Ireland all of its rights, title and interest to certain of its owned and co-owned intellectual property rights relating to the composition, development, manufacture and use of OLED materials, including OLED lighting and display stack technology, as well as certain tangible assets. The intellectual property includes knowhow and more than 500 issued and pending patents in the area of phosphorescent materials and technologies. These assets were acquired in exchange for a cash payment of €86.8 million ($95.8 million). In addition, UDC Ireland also took on certain rights and obligations under three joint research and development agreements to which BASF was a party. The IP Transfer Agreement also contains customary representations, warranties and covenants of the parties. UDC Ireland recorded the payment of €86.8 million ($95.8 million) and acquisition costs incurred of $217,000 as acquired technology, which is being amortized over a period of 10 years.

On July 23, 2012, the Company entered into a Patent Sale Agreement with Fujifilm. Under the agreement, Fujifilm sold more than 1,200 OLED-related patents and patent applications in exchange for a cash payment of $105.0 million, plus $4.5 million in costs incurred in connection with the purchase. The agreement contains customary representations and warranties and covenants, including respective covenants not to sue by both parties thereto. The agreement permitted the Company to assign all of its rights and obligations under the agreement to its affiliates, and the Company assigned, prior to the consummation of the transactions contemplated by the agreement, its rights and obligations to UDC Ireland. The transactions contemplated by the agreement were consummated on July 26, 2012. The Company recorded the $105.0 million plus $4.5 million of purchase costs as acquired technology, which was amortized over a period of 10 years that ended in July 2022.

As a result of the Adesis acquisition in June 2016, the Company recorded $16.8 million of other intangible assets, including $10.5 million assigned to customer relationships with a weighted average life of 11.5 years, $4.8 million to internally developed IP, processes and recipes with a weighted average life of 15 years, and $1.5 million to trade name and trademarks with a weighted average life of 10 years.

At December 31, 2023, these other intangible assets consist of the following (in thousands):


	December 31, 2023
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	10,520	$	(6,801	)	$	3,719
Developed IP, processes and recipes		4,820		(2,388	)		2,432
Trade name/Trademarks		1,500		(1,118	)		382
Other		448		(107	)		341
Total identifiable other intangible assets	$	17,288	$	(10,414	)	$	6,874

Amortization expense related to other intangible assets was $1.4 million for each of the years ended December 31, 2023, 2022, and 2021. Amortization expense is included in amortization of acquired technology and other intangible assets expense line item on the Consolidated Statements of Income and is expected to be $1.4 million for each of the next three fiscal years (2024 - 2026), $1.3 million for the year ending December 31, 2027, $422,000 for the year ending December 31, 2028, and $1.0 million in total thereafter.

As a result of the Adesis acquisition, the Company recorded $15.5 million of goodwill. The Company performs its annual assessment of goodwill during the fourth quarter of the fiscal year unless events suggest an impairment may have been incurred in an interim period using Adesis’ standalone financial operating performance information. Application of the goodwill impairment test requires the exercise of judgment, including the determination of the fair value of each reporting unit, as Adesis is considered to be the reporting unit. As part of the annual assessment of goodwill completed during the fourth quarter ended December 31, 2023, there were no significant indicators to conclude that an impairment of the goodwill associated with the acquisition of Adesis had occurred.