Plastic container having pearl-like appearance and process for producing the same

Abstract

This invention provides a plastic container characterized in that an expanded layer comprising expanded cells having a flat shape with an average major axis of not more than 400 μm and an average aspect ratio (L/t) of not less than 6 as viewed in cross section of the container wall along the maximum stretch direction, which are oriented in the stretch direction and are distributed so as to be superimposed on top of each other in the thickness-wise direction, is formed within the container wall. In this container, expanded cells having a flat shape are distributed so as to orient in a given direction and, thus, has light shielding properties and has a pearl-like appearance, that is, has a very high commercial value. Further, since any colorant is not contained, the suitability for recycling is excellent.

1 .- 15 . (canceled) 
     
     
         16 . A preform for a container formed by integral molding of a thermoplastic resin, wherein a region corresponding to at least a body portion and a bottom portion of the container is a foamed region, said foamed region forming a foamed layer in which foamed cells are isotropically distributed and a skin layer in which no foamed cell is distributed. 
     
     
         17 . (canceled) 
     
     
         18 . The preform for a container according to  claim 16 , wherein a portion corresponding to a container mouth portion and the vicinities thereof are unfoamed regions where no foamed cell is present. 
     
     
         19 . The preform for a container according to  claim 18 , wherein a degree of crystallization in said unfoamed region is not smaller than 13%. 
     
     
         20 . The preform for a container according to  claim 18 , wherein the preform has a shape of a test tube with its bottom closed, and has, on an outer surface at an upper portion thereof, a neck portion comprising a support ring and a threaded portion positioned above the support ring, said neck portion being the unfoamed region.