Sojitz Corporation


New Environmentally-Friendly Recyclable Lead Gypsum Wallboard Developed

First Building Material to Receive Lead Plate Recycling Mark

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Oct. 17, 2011
Sojitz Corporation
Sojitz Building Materials Corporation

Sojitz Building Materials Corporation, a wholly-owned subsidiary of Sojitz Corporation, and Koyo Sango Co., Ltd. will begin selling Koyo Eco Lead Board, a lead gypsum wallboard developed by Koyo Sangyo whose lead is easily recycled. The Koyo Eco Lead Board is the first building material to receive a lead plate recycling mark.

Lead gypsum wallboard is a building material generally used in the walls, ceilings, and floors of X-ray rooms in hospitals and other facilities. Use is expected to expand to general residences because of the shielding performance and sound insulation properties of the lead.

The new Koyo Eco Lead Board employs a special adhesive process (patent pending) developed by Koyo Sangyo that allows the lead and the gypsum board to be separated without waste, a process that is difficult with earlier products. Separation of the materials is expected to promote recycling of the lead. In recognition of this property, Koyo Eco Lead Board became the first building material to receive a lead plate recycling mark.

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Earlier Product

Koyo Eco Lead Board

The battery industry, which is the primary user of lead, has achieved nearly 100% recycling of lead, but in the building materials field, separating the lead from the wallboard has been difficult, and there have been calls for improved recyclability. In addition, the price of lead has nearly doubled since hitting bottom at the end of 2008 following the collapse of Lehman Brothers, making improved recycling an even more urgent matter.

Koyo Sangyo developed a pioneering eco product, a highly water resistant two-component water-based polymer isocyanate adhesive, 37 years ago (patented worldwide). By using this blending technology, Koyo Sangyo developed an environmentally-friendly separable adhesive sheet known as MT Sheet in 2010. The new Koyo Eco Lead Board uses the MT Sheet adhesion processing technology.

Sojitz and Sojitz Building Materials are actively working towards the development of a recycling-based society, and Sojitz Building Materials will perform as the general distributor for Koyo Eco Lead Board. Sojitz Building Materials obtained ISO 14001 certification in 2004 and FSC (Forest Stewardship Council) and PEFC (Programme for the Endorsement of Forest) certification in 2009 and is working to increase the use of environmentally-friendly products with a focus on wood and building products. Koyo Eco Lead Board is positioned as a safe, recyclable, resource-saving building material, and Sojitz Building Materials hopes to increase its use as an important material - along with plywood and manufactured wood products made from planted trees, solar panels, LED lights, insulating paints, and other products - for reducing environmental impact.

Koyo Sangyo and Sojitz Building Materials will launch Koyo Eco Lead Board in December 2011 and have set a target of reaching sales of 1 billion yen within five years.

Product Overview

Product name Koyo Eco Lead Board
Materials Leads and gypsum board integrated product
Standard sizes
(lead/gypsum board, size)
t1.5/t12.5, 910 mm × 1820 mm
t2.0/t12.5, 910 mm × 1820 mm
Features The lead and gypsum board can be separated on site without waste, facilitating waste sorting and processing. Can be installed in the same manner as other lead gypsum board products. Does not contain formaldehyde.
Applications Radiation shielding, sound insulation, etc.


Company name KOYO SANGYO Co., Ltd.
Representative Soichi Funayama
Head office Chiyoda-ku, Tokyo
Capital 180 million yen
Business activities Manufacture and sale of adhesives and sound and vibration insulating materials

General Distributor

Company name Sojitz Building Materials Corporation
Representative Masahiko Takeshita
Head office Chiyoda-ku, Tokyo
Capital 1,039 million yen
Business activities Sale of building materials

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