Polyvinyl butyral resin pellet, and method for producing the same

Abstract

According to the present invention, a polyvinyl butyral resin pellet is provided that gives off little odor when produced and handled, as well as has a high apparent density and favorable handleability. The present invention includes a method for producing a polyvinyl butyral resin pellet including the steps of melting polyvinyl butyral resin powder with a water content of 0.01 to 6 wt % by means of a melt extruder that has at least one vent portion for devolatilization equipped with vacuum means, and cutting the melt of the polyvinyl butyral resin after extrusion of it from the melt extruder. The present invention further includes a polyvinyl butyral resin pellet having a total content of butyl aldehyde and 2-ethyl-2-hexenal of 100 ppm or less.

1 - 3 . (canceled) 
     
     
         4 . A polyvinyl butyral resin pellet obtainable by the method for producing a polyvinyl butyral resin pellet comprising:
 melting polyvinyl butyral resin powder with a water content of 0.01 to 6 wt % in a melt extruder that includes at least one vent portion for devolatilization equipped with a vacuum; and   cutting a melt of the polyvinyl butyral resin after extrusion of the melt from the melt extruder.   
     
     
         5 . A polyvinyl butyral resin pellet having a total content of butyl aldehyde and 2-ethyl-2-hexenal of 100 wt ppm or less. 
     
     
         6 . The polyvinyl butyral resin pellet according to  claim 5 , wherein its acid value is 0.7 mg KOH/g or less. 
     
     
         7 . The polyvinyl butyral resin pellet according to  claim 5 , wherein its size is 0.5 to 2.5 mm.