The Riverside Company’s Latest Add-On to Seatex Serves as Catalyst for Growth

The Riverside Company, a global investment firm focused on the smaller end of the middle market, has invested in Key Polymer, a specialty manufacturer of high-performance adhesives, sealants and coatings for a diverse range of industries. This investment is the first add-on to platform company Seatex, a leading provider of chemical manufacturing and technology solutions for startups through Fortune 100 companies.

Founded in 1959, Key Polymer is a provider of both proprietary chemistry and custom blending services operating through the Key Polymer, Unichem, Crosslink and Durant brands. The company serves customers through two ISO 9001:2015–certified manufacturing facilities in Lawrence, Massachusetts and Greenville, South Carolina, each supported by robust formulation and product development capabilities. Key Polymer’s primary product technologies include acrylics, epoxies, urethanes, butyl rubber wax blends, bonding agents and fire retardants, and are used in a wide variety of segments, including industrial, automotive, aerospace, electronics, transportation manufacturing and construction infrastructure.

“Key Polymer is an excellent complement to the Seatex platform,” said Riverside Partner Craig Kahler. “This represents our first follow-on acquisition since we acquired Seatex in October 2024 and materially advances our plans to expand the end market and geographic reach of the platform.”

Riverside Operating Partner Pradeep Saha added, “Key Polymer has been successful at growing its business in recent years and brings many strengths to the combined organization including exceptional technical capabilities and a strong market position in the growing CASE (coatings, adhesives, sealants, elastomers) segment.”

This investment highlights Riverside’s expertise in Specialty Manufacturing and Distribution. The firm has completed more than 300 investments in this specialization and has a team of global experts dedicated to growing these types of organizations.

“Seatex and Key Polymer share a culture of respect, passion for our work, and relentless commitment to gaining our customer’s trust through problem solving and delivering valuable solutions,” said Seatex Executive Chairman Jeff Welsh. “We are thrilled to welcome them to the organization.”

“We are excited to join with Seatex to expand our services and capabilities for our combined customer base,” said Key Polymer President Bill Newman. “Our team looks forward to working closely with Jeff and Pradeep to continue to deliver winning results for all of our employees and customers.”

Working with Kahler on this deal for Riverside were Vice President Zak Northrup, Associate Calvin Alex and Operating Partner Pradeep Saha. The investment was sourced by Regional Director, Origination, David Fowles.