Goodwill and Intangible Assets (Tables)

9 Months Ended

Jun. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes in Balances

The carrying amount of goodwill attributable to each reportable segment and the changes in those balances during the nine months ended June 30, 2025 are as follows:

	Reinforcement Materials		Performance Chemicals			Total
	(In millions)
Balance at September 30, 2024	$	48	$	85		$	133
Foreign currency impact		1		(1	)		—
Balance at June 30, 2025	$	49	$	84		$	133

Schedule of Intangible Assets

The following table provides information regarding the Company’s intangible assets:

	June 30, 2025							September 30, 2024
	Gross Carrying Value		Accumulated Amortization			Net Intangible Assets		Gross Carrying Value		Accumulated Amortization			Net Intangible Assets
	(In millions)
Intangible assets with finite lives
Developed technologies(1)	$	41	$	(14	)	$	27	$	34	$	(12	)	$	22
Trademarks		2		(1	)		1		2		(1	)		1
Customer relationships		62		(34	)		28		60		(30	)		30
Total intangible assets	$	105	$	(49	)	$	56	$	96	$	(43	)	$	53

(1)Included within Developed technologies as of June 30, 2025 is $8 million of intangible assets acquired during the first quarter of fiscal 2025 as discussed in Note C above.