60th Anniversary Exhibition of Kagawa Prefecture lacquer Institute has been held.

Originally lacquer coating strongly robust heat and humidity, because it is resistant to acid and alkali, and has been used as paints and adhesives and waterproofing agents.

In addition, Urushi is provided with a unique texture and luster, unique beauty is consistent with the aesthetics of Japanese, many of lacquer ware has been created.

Lacquer ware completed through green body process to create a foundation and the underlying process for shaping the green body, coating step of repaint the lacquer on the underlying surface, the process over the long trouble of decorating process to put the pattern on the lacquer surface.

urushi

Recently, chemical paint has been used as an indoor paint, but can cause sick house syndrome by solvent evaporates. Lacquer has the property of drying themselves unlike science paint. Also, once it completely dry, you do not have poison ivy. Lacquer is as natural paints, has been attracting attention as health friendly paint of environment and people.

How the lacquer to dry (the lacquer dries as fast as the day of rain)

Lacquer of the main component is a resin content of urushiol.

The ratio of urushiol ingredient rises as good lacquer.

Temperature if become humid, an enzyme (laccase) included in the urushiol is activated, and take in oxygen from atmospheric water, and, by an oxidation reaction with the urushiol, constitute a huge macromolecule of the halftone plate structure scientifically.

It changes from a liquid into a solid on the appearance.

It is said, "lacquer dries" in this course.

The lacquered drying is not a phenomenon that water evaporates and dries, and it means that an enzyme makes a macromolecule.

Temperature (around 25 degrees) and the humidity (around 75%) necessary to let an enzyme activate are necessary so that lacquer dries.

Therefore the lacquer dries early because an oxidation reaction promotes it as the season of high temperature and humidity in the rainy season.

 The lacquer dries early as a day of the rainy weather.

 It becomes sealing up structure that the lacquer bath puts the board of a hinoki and the cedar and enhances protection against dust, thermal insulation, an effect of the humidity retention, and temperature and the humidity that are most suitable for lacquered drying come to be found.

【漆が乾燥するしくみ（雨天の日ほど早く乾く）】
漆の主成分はウルシオールという樹脂分で、フェノール系の物質。上等な漆ほどウルシオール成分の割合は高くなります。温度や湿度が高くなると、ウルシオール中に含まれている酵素（ラッカーゼという）が活性化し、空気中の水分から酸素を取り込み、ウルシオールとの酸化反応によって、科学的には網目構造の巨大な高分子を構成します。外見上では液体から固体へと変化します。この課程を「漆が乾く」といいます。漆の乾燥とは、水分が蒸発して乾くという現象でなく、酵素が高分子を作るということです。

漆が乾くためには、酵素を活性化させるために必要な温度（25度程度）と湿度（75%程度）が必要です。そのため、梅雨時の高温多湿の季節ほど酸化反応が促進するので、漆は早く乾燥します。雨天の日ほど漆は早く乾燥するのです。漆風呂（うるしぶろ）は檜や杉の板を貼って防塵、保温、保湿の効果を高める密閉構造になっており、漆の乾燥に最適な温度と湿度が確保されるようになっています。