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):


	September 30, 2023 (1)			December 31, 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		(182,657	)		(189,671	)
Acquired technology, net	$	94,518		$	38,382

(1)

During the nine months ended September 30, 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 $4.2 million and $3.2 million for the three months ended September 30, 2023 and 2022, respectively, and $10.4 million and $13.5 million for the nine months ended September 30, 2023 and 2022, respectively. Amortization expense is included in the amortization of acquired technology and other intangible assets expense line item on the Consolidated Statements of Income and is expected to be $4.2 million for the three months ending December 31, 2023, $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 the year ending December 31, 2027 and $37.5 million in total thereafter.

On April 28, 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.

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 September 30, 2023, these other intangible assets consist of the following (in thousands):


	September 30, 2023
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	10,520	$	(6,571	)	$	3,949
Developed IP, processes and recipes		4,820		(2,308	)		2,512
Trade name/Trademarks		1,500		(1,080	)		420
Other		448		(96	)		352
Total identifiable other intangible assets	$	17,288	$	(10,055	)	$	7,233

Amortization expense related to other intangible assets was $359,000 and $358,000 for the three months ended September 30, 2023 and 2022, respectively, and $1.1 million for both the nine months ended September 30, 2023 and 2022. Amortization expense is included in the amortization of acquired technology and other intangible assets expense line item on the Consolidated Statements of Income and is expected to be $359,000 for the three months ending December 31, 2023, $1.4 million for each of the next three fiscal years (2024 - 2026), $1.3 million for the year ending December 31, 2027 and $1.3 million in total thereafter.