Release Details

NEW YORK--(BUSINESS WIRE)--June 25, 2004--Minerals Technologies Inc. (NYSE: MTX) on June 15 filed suit for patent infringement and injunctive relief against Switzerland-based Omya AG in the United States District Court in the Southern District of New York.

The suit, filed by Minerals Technologies and its wholly owned subsidiary, Specialty Minerals Inc., alleges that Omya AG and its subsidiaries, Omya Industries Inc. and Omya, Inc., have infringed, are inducing the infringement of, or are contributing to the infringement of two patents covering the use of calcium carbonate in the manufacture of acidic paper.

"Minerals Technologies is a global research-based company that provides to our customers high quality innovative products developed from our proprietary technology," said Paul R. Saueracker, chairman, president and chief executive officer. "We felt compelled to file this suit to protect that proprietary technology. However, while we intend to pursue this issue through the courts, the company is committed to making this important technology widely available to the paper industry through licensing arrangements."

The Company's technology is commonly referred to as acid tolerant technology. Specialty Minerals Inc. commercialized this technology through its product AT(R) precipitated calcium carbonate. The patents covering this proprietary technology are entitled "Acid-Stabilized Calcium Carbonate, Process for its Production and Method for its Use in the Manufacture of Acidic Paper." These patents were issued by the U.S. Patent and Trademark Office on August 27, 1991 and October 20, 1992 respectively.

Minerals Technologies argues that its business has been, and continues to be, damaged by this alleged infringement, including substantial loss of profits. Consequently, the complaint asks the court that Omya be preliminarily and permanently enjoined from infringing, contributing to, and inducing others to infringe the patents in this suit.

Minerals Technologies Inc. is a Delaware corporation with headquarters in New York, NY. Omya AG is a worldwide minerals company headquartered in Oftringen, Switzerland.

Minerals Technologies Inc. is a global resource- and technology-based growth company that develops, produces and markets the highest quality performance-enhancing minerals and related products, systems and services for the paper, steel, polymer and other manufacturing industries. The company reported sales of $813.7 million in 2003.

For further information about Minerals Technologies Inc. look on the Internet at www.mineralstech.com

    CONTACT: Minerals Technologies Inc.
             Rick B. Honey, 212-878-1831

    SOURCE: Minerals Technologies Inc.