日韩视频精品,国产欧美亚洲精品第3页在线,中国乱伦毛片视频,黄片中文字幕免费大全110,亚洲第一黄色视频污,国产黄色三级战线免费观看av,小黄片在线免费观看亚洲天堂

Your Current Position:  PRODUCTS > Gum Rosin series > Gum Rosin

Gum Rosin

Rosin is a kind of natural resin, mainly composed of various resin acids, soluble in a variety of solvents, with unique chemical activity. It is an important raw material for papermaking, coating, ink, rubber, soap, electronics, edible ester gum, rosin ester resin and other industries.