As semiconductors become more highly integrated and are required to deliver increasingly higher performance, there is growing demand for semiconductor encapsulant materials with reduced radiation, such as alpha radiation, which can trigger malfunctions in advanced semiconductors, as well as improved heat dissipation properties. Dongwoo Fine-Chem Co., Ltd., a wholly-owned Korean subsidiary of Sumitomo Chemical, has successfully developed a new product line that meets these needs: the ELA series of low alpha radiation, high-purity fine spherical alumina products, the world’s first of its kind ^(*3).

The ELA series offers the advantages of having both extremely low radiation levels and excellent heat dissipation properties. These features make it particularly well suited for applications that require a high level of reliability, such as advanced semiconductors for AI. In addition, its particle size can be precisely controlled to within several micrometers or less, and its surface properties can be customized to suit specific applications to meet the needs of customers.

Sumitomo Chemical is also expanding its lineup of high-purity alumina products for use in ceramic equipment materials and process materials, as performance requirements for these applications are becoming increasingly rigorous due to advances in the semiconductor manufacturing process. For its previously launched NXA series of ultra-fine alumina products, the Company is working with customers to explore ways to take full advantage of the product line’s high performance potential, and has verified that the use of the NXA series has led to significant performance improvement in these applications.

In recent years, as the advanced semiconductor market has seen increased demand for even higher performing peripheral materials, expectations for solutions using inorganic materials have grown. By positioning its ELA series and NXA series as key product lines that will drive growth in its high-purity alumina business, Sumitomo Chemical will work to globally expand its sales in the field of advanced semiconductors. The Company will also strive to strengthen its collaborations with customers and advance the development of new grades of high-purity alumina to meet customer needs. In doing so, it will continue to contribute to the growth of the semiconductor industry, which supports digital innovations such as AI and data communications, and the achievement of a smart society.

*1 　Purity levels of 99.99% or higher
*2 　Alumina is made by heating aluminum hydroxide at high temperatures.
*3 　As of the publication of this press release on May 7, 2026; based Sumitomo Chemical’s own research

Reference

News release
“Sumitomo Chemical to Produce Pioneering Ultra-Fine Alumina Products (NXA series) Creating New Markets through Innovations in Inorganic Materials,” press release dated August 28, 2023

Sumitomo Chemical’s Product Databook  https://www.sumitomo-chem.co.jp/english/products/files/docs/en_a06008.pdf

Mitsui Chemicals, Inc.
Idemitsu Kosan Co.,Ltd.
Sumitomo Chemical Co., Ltd.

Mitsui Chemicals, Inc. (head office: Chuo-ku, Tokyo; President & CEO: Satoshi Ichimura; hereinafter “Mitsui”), Idemitsu Kosan Co.,Ltd. (head office: Chiyoda-ku, Tokyo; Representative Director, President: Noriaki Sakai; hereinafter “Idemitsu”), and Sumitomo Chemical Co., Ltd. (head office: Chuo-ku, Tokyo; Representative Director and President: Nobuaki Mito; hereinafter “Sumitomo Chemical”) announced on September 10, 2025, a basic agreement regarding the integration of the polyolefin (PO) business operated by Prime Polymer Co., Ltd. (head office: Chuo-ku, Tokyo; President: Yukiharu Goto; hereinafter “PRM”), a joint venture between Mitsui and Idemitsu, with Sumitomo Chemical’s polypropylene (PP) business and linear low-density polyethylene (LLDPE) business in Japan (such integration, the “Business Integration”). This integration aims to realize resilient and essential businesses that support Japanese industries and to enhance the competitiveness of the PO business, including PP and polyethylene (PE), in Japan. Subsequently, on December 24, 2025, the companies announced the conclusion of a business integration agreement (“Business Integration Agreement”) and a joint venture agreement regarding the Business Integration.

For the purpose of the Business Integration, PRM and Sumitomo Chemical submitted a plan notification regarding the Business Integration to the Japan Fair Trade Commission pursuant
to the Act on Prohibition of Private Monopolization and Maintenance of Fair Trade and have been undergoing the Japan Fair Trade Commission’s review.
As a result, notice has today been received from the Japan Fair Trade Commission that it will not issue a cease-and-desist order.

Overseas merger review procedures by relevant competition authorities are currently ongoing, and the Business Integration is scheduled to be implemented after the completion of such reviews.

Reference

September 10, 2025：Mitsui Chemicals, Idemitsu Kosan, and Sumitomo Chemical Enter Into MOU on Integration of Sumitomo Chemical’s PP and LLDPE Businesses into Prime Polymer, Aiming to Strengthen the Competitiveness of the Domestic Polyolefin Business

December 24, 2025：Mitsui Chemicals, Idemitsu Kosan, and Sumitomo Chemical Concluded a Definitive Agreement for the Business Integration of Sumitomo Chemical’s PP and LLDPE

Contact

Mitsui Chemicals, Inc.
Corporate Communications Division
https://form.mitsuichemicals.com/corporate/cc_pr_csr_en?param=13

Idemitsu Kosan Co.,Ltd.
Public Relations Department Public Relations Section
https://www.idemitsu.com/en/contact/flow/index.html

Sumitomo Chemical Co., Ltd.
Corporate Communications Dept.
https://www.sumitomo-chem.co.jp/english/contact/public/

Sumitomo Chemical has decided to construct a new facility that integrates photoresist manufacturing process technology management, quality evaluation, and analytical functions at its Osaka Works, located in Konohana-ku, Osaka, in order to further strengthen its supply system for photoresists for advanced semiconductors, including extreme ultraviolet (EUV) and argon fluoride (ArF) photoresists. The Company plans to complete the construction of this facility by the end of fiscal 2027.

Photoresists are photosensitive resins used in the semiconductor manufacturing process to form circuit patterns. They are essential materials that support the miniaturization and multilayering of advanced logic and memory semiconductors. Demand for higher performance, higher quality photoresists and their stable supply is expected to continue to rise, driven by the widespread use of generative AI, the advancement of IoT, and expanding investment in data centers. Sumitomo Chemical has expanded its advanced semiconductor photoresist business by building on the organic synthesis technologies it has cultivated through its fine chemicals business and leveraging its world-class technological capabilities.

In 2022, Sumitomo Chemical built new development and evaluation facilities for photoresists at its Osaka Works, where it has, in phases, brought in advanced exposure equipment used to manufacture semiconductors to strengthen its development capabilities from material design through evaluation. To translate what is achieved in the development process into reliable product supply, more sophisticated process control in manufacturing lines is needed. It also requires a system that can manage each step of the process with high precision, from pre‑qualification of raw materials through shipment of the product. The new facility will integrate functions related to manufacturing process technology management, quality evaluation, and analysis for EUV and ArF photoresists, which were previously spread out across Osaka Works, to achieve more advanced process control. The Company will implement this project to expedite the startup of mass production and further stabilize product quality through refined process development, thereby delivering a higher level of product quality and reliability and supply stability. By enhancing the supply system for cutting-edge photoresists to seamlessly handle the whole process from development and mass production to analysis at Osaka Works, Sumitomo Chemical will further strengthen its ability to stably supply products worldwide.

The Sumitomo Chemical Group positions its semiconductor materials business as one of its growths drivers and is focusing resources on actively expanding the business. To date, the Group has steadily invested in its photoresist business, one of the strategic product categories in its semiconductor materials business, through measures such as expanding manufacturing capacity at plants in Japan, constructing new development and evaluation facilities for advanced products, and establishing new manufacturing lines in its facility in South Korea. Sales of EUV and ArF photoresists are expanding steadily, and the Company’s development of next-generation EUV photoresists, including proprietary organic molecular photoresists, is accelerating. Going forward, the Group will continue to work hard to develop new areas of semiconductor materials and contribute to achieving a smart society through the stable supply of high quality products.

Overview of the new facility

Europe has a vast crop protection market, surpassing that of North America^*1. At the same time, as environmental regulations have been tightened in recent years, demand for biorationals^*2 has increased in the region, and those products are becoming a pillar to support Europe’s future agricultural production. In the European crop protection market, France accounts for the largest share^*3. To expand its agricultural solutions business in the country, Sumitomo Chemical acquired shares of its French subsidiary Philagro Holding in January 2025, making it a wholly-owned subsidiary, and has since been working to integrate the operations of SCAE and Philagro Holding. The integration announced today will further advance these efforts, consolidating development, sales, and administrative functions of SCAE, Philagro Holding, and Philagro France and thereby enhancing organizational efficiency and agility. Going forward, SCAE will further strengthen its sales strategy of promoting conventional crop protection products along with biorationals and other environmentally friendly products, and will also establish an operations system that can swiftly and accurately respond to evolving market needs in France. SCAE will continue to provide the same level of support and services to local producers, distributors, and business partners, and will strive to build even stronger relationships of trust with those stakeholders while it will actively pursue business expansion in France.

The Sumitomo Chemical Group will continue to leverage SCAE as the core of its operations in France and the rest of Europe, as well as in the Middle East and Africa. Furthermore, the Group remains committed to contributing to advancing regenerative agriculture and achieving a sustainable society through the development and sale of innovative, environmentally friendly crop protection products and a wide range of biorationals.

Overview of Surviving Company After Integration

Overview of Subsidiaries Before Integration

*1  Europe is ranked third among the largest crop protection markets in the world, after Latin America and Asia, followed by North America and the Middle East and Africa (source: The Crop Protection Industry Report, November 2025, by AgbioCrop).
*2  The Sumitomo Chemical Group defines biorationals as microbial pesticides, plant growth regulators, rhizosphere microbial products, botanical insecticides derived from natural sources, and solutions that use them to (1) protect crops from pests and diseases, (2) enhance crop quality and yield, and (3) contribute to public health and environmental health.
*3  France is ranked seventh among the major agricultural countries in the world and first in Europe (source: Market Review 2024, by AgbioCrop).

Reference

News release
Sumitomo Chemical’s Full Acquisition of Two Crop Protection Companies
Stepping Up Efforts to Further Expand its European Crop Protection Business, Exploring Business Reorganization and M&A Opportunities
January 30, 2025
https://www.sumitomo-chem.co.jp/english/news/detail/20250130e.html

The Summit was hosted by the GCNJ, one of the Country Networks of the United Nations Global Compact, as part of the GCNJ Collective Action 2030 initiative, which defines priority issues in Japan to achieve a sustainable future. Forty-one companies have endorsed the GCNJ’s vision of achieving a fair work environment and announced action plans to fulfill it, and representatives from eleven of those companies spoke at the event, including Sumitomo Chemical President Nobuaki Mito. At the roundtable session in the Summit, President Nobuaki Mito shared initiatives Sumitomo Chemical is implementing, mostly related to overcoming the culture and bias of valuing long working hours. He also took part in lively discussions with other event participants.

Sumitomo Chemical has for many years worked to develop systems that enable its employees to balance childcare and caregiving with work and strived to create a workplace environment in which these systems can be easily utilized, by fostering labor-management cooperation. In addition, the Company has endeavored to promote men’s participation in childcare and empower women in the workforce and strived to eliminate unconscious biases that impede these efforts. For example, the Company has set the target of percentage of men who take paternity leave and a quantitative target related to the promotion of women to management positions as its key performance indicators. Through these initiatives, the Company aims to create a workplace environment in which both men and women are able to continue working while raising children or caring for family members, as well as one in which motivated employees are able to take on new challenges.

Sumitomo Chemical will continue to strive to achieve a workplace in which all of its employees are able to feel empowered and perform at their best. The Company will also continue its efforts to promote diversity, equity, and inclusion.