17 Thermal insulating materials; thermal insulating materials of alumina fiber for exhaust gas treatment systems; insulating refractory materials; insulators; soundproofing materials of alumina fiber, not for building purposes; alumina fiber, not for textile use; chemical fiber, not for textile use; seals; seals of alumina fiber; non-conducting materials for retaining heat for nuclear reactors and industrial furnaces for plumbing purposes; plastic semi-worked products; insulating materials of alumina fiber for exhaust gas treatment systems and thermal treatment systems for automobiles; thermal insulating blankets of alumina fiber, not for building purposes; thermal insulating boards of alumina fiber for heating furnaces for industrial purposes; thermal insulating mats of alumina fiber, not for building purposes; thermal insulating boards of alumina fiber, not for building purposes; thermal insulating materials for industrial furnaces; insulating sheets for hot water heaters; insulating materials for water heaters; insulating materials for boilers, fuel cells and pipes; shock-absorbing buffers of alumina fiber for exhaust gas treatment systems and thermal treatment systems for automobiles; seals for exhaust gas purification installations; thermal seals; seals of alumina fiber in bulks; insulating refractory materials of inorganic fiber; electrical insulating materials; packings of alumina fiber; alumina fiber in the form of powder or granules, not for building materials; alumina fiber in the form of mats, not for building materials; alumina fiber, not for textile use; inorganic fiber, not for textile use; thermal insulating sheets of alumina fiber, not for building purposes; thermal insulating sheets of inorganic fiber, not for building purposes; thermal insulating materials for exhaust gas treatment systems for automobiles, two-wheeled motor vehicles, bicycles, vessels, aircraft, railway rolling stock, agricultural machines and agricultural implements, mining machines and apparatus, construction machines and apparatus, loading-unloading machines and apparatus, industrial fishing machines, forestry machines and apparatus, snow ploughs, lawnmowers, mowing machines, grass trimmers, blowers for outdoor vacuum cleaners, blowing machines and fixed engines; thermal insulating materials for exhaust gas treatment systems for automobiles; thermal insulating materials for exhaust gas treatment systems for power plants; thermal insulating materials for exhaust gas treatment systems; seals for exhaust gas treatment systems; sound or acoustic insulation materials for exhaust gas treatment systems