October 2, 2009
Application of Clathrate Compound Technology to a New Field
Development of the World’s First Electrolyte Blowout Prevention Material Improves the Safety of Capacitors
Kurita Water Industries Ltd. (Head Office: Shinjuku-ku, Tokyo, President: Hiroshi Saito) has applied its clathrate compound technology to develop the world’s first electrolyte blowout prevention material for aluminum electrolytic capacitors. The newly developed material can absorb electrolyte that would otherwise be discharged by the capacitor at the time of electrical anomalies, thus improving the safety of the capacitor and preventing the electrolyte from spouting.
An abnormal voltage passed on to an aluminum electrolytic capacitor increases its temperature, resulting in the vaporization of the electrolyte and an increase in internal pressure. When the capacitor’s pressure valve is actuated due to the internal pressure rising above a certain level, the gasified electrolyte is instantaneously discharged.
Aluminum electrolytic capacitors are widely used in general household lighting fixtures and electrical appliances and householders and other users have occasionally misidentified the vaporized electrolyte blowout or its associated odor as a possible source of ignition. In the same way, the attachment of the gasified electrolyte to a printed circuit board has caused short-circuiting.
2. New product
We have developed a new material that prevents electrolyte blowout based on our clathrate compound technology, which has been used to stabilize chemicals used in water treatment and fuels used in fuel cells for around 20 years. This material, applied to a capacitor, instantaneously absorbs the vaporized high-temperature electrolyte components, thus solving the problem described above.
The features of this product are summarized as follows:
- 1)Instantaneous absorption of discharged electrolyte
- The material controls electrolyte discharge and the generation of odor, thus relieving users of the unnecessary and erroneous concern that a potential source of ignition has been created.
- The material prevents the electrolyte from attaching to a printed circuit board, thus solving the problem of short-circuit.
- 2)Environmentally friendly
- The new product is RoHS Directive compliant.
3. Target application and future plan
- 1)Target application
The product is applicable to general aluminum electrolytic capacitors using electrolyte. In particular, it is suitable for aluminum electrolytic capacitors for long-term use in household lighting fixtures, and in power circuits or AC adaptors for household electrical appliances. Furthermore, the product is planned to be used for large electrolytic capacitors for which high levels of safety are required.
- 2)Future plan
We will begin by supplying the products to a capacitor manufacturer, Nichicon Corporation (Head Office: Nakagyo-ku, Kyoto, President: Sachihiko Araki) and aim to start mass production within this fiscal year (by the end of March 2010).
- 1)Clathrate Compound Technology
Clathrate compound technology is a technique used to integrate certain "guest" molecules into a group of regular or porous "host" molecules at a certain composition ratio, thus creating a clathrate compound with a specific crystalline structure. Certain combinations of host molecules enable the stabilization of dangerous materials and help sustain the effects of substances for a long time. They can be used for household products such as aromatic substances and deodorants.
- 2)RoHS Directive
The RoHS Directive, adopted by the European Union, restricts the use of six hazardous materials including lead in the manufacture of electronic and electrical equipment. The RoHS Directive bans the sale of electronic and electrical equipment containing any hazardous material above a designated level within the EU after July 2006.