Hinge Cap Having Biodegradability

Abstract

A hinge cap comprising a cap body composed of a top wall, an ejection port provided in the top wall and a sidewall suspending from the circumferential edge of the top wall, and an upper lid hinged to the cap body and closing the ejection port, characterized in that the cap is composed of polyalkylene alkanoate resin having a flexural elastic modulus of 200-900 MPa, more preferably 300-800 MPa.

1 - 12 . (canceled)  
   
   
       13 . A hinge cap comprising: 
 a cap body comprising a top wall, an ejection port formed in the top wall and a side wall suspending from a circumferential edge of the top wall; and    an upper lid connected with the cap body via a hinge for closing the ejection port;    wherein the cap body and the upper lid are biodegradable and the cap is made of a polyalkylene alkanoate resin having a flexural elastic modulus of from 200 to 900 MPa.    
   
   
       14 . The hinge cap according to  claim 13 , wherein the cap is made of a polyalkylene alkanoate resin and the flexural elastic modulus is from 300 to 800 MPa.  
   
   
       15 . The hinge cap according to  claim 13 , wherein the polyalkylene alkanoate resin is polybutylene succinate, its copolymer or a mixture thereof.  
   
   
       16 . The hinge cap according to  claim 14 , wherein the polyalkylene alkanoate resin is polybutylene succinate, its copolymer or a mixture thereof.  
   
   
       17 . The hinge cap according to  claim 15 , wherein the copolymer of the polybutylene succinate is polybutylene succinate adipate.  
   
   
       18 . The hinge cap according to  claim 16 , wherein the copolymer of the polybutylene succinate is polybutylene succinate adipate.  
   
   
       19 . The hinge cap according to  claim 13 , wherein the polyalkylene alkanoate resin contains from 0.01 to 5 parts by weight of a fatty acid, a fatty acid amide or a mixture of a fatty acid and a fatty acid amide, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       20 . The hinge cap according to  claim 14 , wherein the polyalkylene alkanoate resin contains from 0.01 to 5 parts by weight of a fatty acid, a fatty acid amide or a mixture of a fatty acid and a fatty acid amide, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       21 . The hinge cap according to  claim 15 , wherein the polyalkylene alkanoate resin contains from 0.01 to 5 parts by weight of a fatty acid, a fatty acid amide or a mixture of a fatty acid and a fatty acid amide, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       22 . The hinge cap according to  claim 13 , wherein the polyalkylene alkanoate resin contains from 1 to 10 parts by weight of an antiblocking agent, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       23 . The hinge cap according to  claim 14 , wherein the polyalkylene alkanoate resin contains from 1 to 10 parts by weight of an antiblocking agent, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       24 . The hinge cap according to  claim 15 , wherein the polyalkylene alkanoate resin contains from 1 to 10 parts by weight of an antiblocking agent, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       25 . The hinge cap according to  claim 13 , wherein the polyalkylene alkanoate resin contains from 0.1 to 10 parts by weight of a hydrolysis inhibitor, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       26 . The hinge cap according to  claim 14 , wherein the polyalkylene alkanoate resin contains from 0.1 to 10 parts by weight of a hydrolysis inhibitor, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       27 . The hinge cap according to  claim 15 , wherein the polyalkylene alkanoate resin contains from 0.1 to 10 parts by weight of a hydrolysis inhibitor, per 100 parts by weight of the polyalkylene alkanoate.  
   
   
       28 . The hinge cap according to  claim 13 , wherein the hinge includes a snap function in turning the upper lid relative to the cap body.  
   
   
       29 . The hinge cap according to  claim 28 , wherein the hinge comprises a thin hinge connecting the side wall of the cap body and the side wall of the upper lid, and a pair of elastic connection plates connecting the side wall of the cap body and the side wall of the upper lid on both sides of the thin hinge.  
   
   
       30 . The hinge cap according to  claim 29 , wherein the thin hinge and the elastic connection plates are integrally formed via a thin film.  
   
   
       31 . The hinge cap according to  claim 13 , wherein a retention ratio of a tensile breaking stress of the hinge after opening and closing the upper lid 3,000 times is 30% or more.  
   
   
       32 . The hinge cap according to  claim 13 , wherein a retention ratio of a tensile breaking stress of the hinge after opening and closing the upper lid 3,000 times is 50% or more.