Process for preparing formed item of aliphatic polyester and formed item prepared by the process

Abstract

The invention provides an aliphatic polyester formed item having transparency and crystallinity in combination by crystallizing, in the course of or after processing, an aliphatic polyester composition comprising aliphatic polyester and one or more transparent nucleating agent selected from the group consisting of aliphatic carboxylic acid amide, aliphatic carboxylic acid salt, aliphatic alcohol and aliphatic carboxylic acid ester having a melting point of 40-300° C.

What is claimed is:  
     
         1 . A preparation process of an aliphatic polyester formed item having transparency and crystallinity in combination comprising processing an aliphatic polyester composition comprising aliphatic polyester which develops no crystallization in temperature drop from the melting point to the glass transition temperature at a velocity of 10° C./min, and one or more transparent nucleating agent selected from the group consisting of an aliphatic carboxylic acid amide, an aliphatic carboxylic acid salt, an aliphatic alcohol and an aliphatic carboxylic acid ester having a melting point of 40-300° C., and carrying out heat-treatment in the course of or after processing.  
     
     
         2 . A preparation process of an aliphatic polyester formed item having transparency and crystallinity in combination comprising processing an aliphatic polyester composition comprising aliphatic polyester which generates crystal in temperature drop from the melting point to the glass transition temperature at a velocity of 10° C./min, and one or more transparent nucleating agent selected from the group consisting of an aliphatic carboxylic acid amide, an aliphatic carboxylic acid salt, an aliphatic alcohol and an aliphatic carboxylic acid ester having a melting point of 40-300° C.  
     
     
         3 . The preparation process of the aliphatic polyester formed item according to  claim 1  wherein the ratio of the transparent nucleating agent to aliphatic polyester in the aliphatic polyester composition is 0.1-10 parts by weight of the transparent nucleating agent for 100 parts by weight of aliphatic polyester.  
     
     
         4 . The preparation process of the aliphatic polyester formed item according to  claim 2  wherein the ratio of the transparent nucleating agent to aliphatic polyester in the aliphatic polyester composition is 0.1-10 parts by weight of the transparent nucleating agent for 100 parts by weight of aliphatic polyester.  
     
     
         5 . The preparation process of the aliphatic polyester formed item according to  claim 3  wherein the aliphatic polyester is polylactic acid and the transparent nucleating agent is aliphatic carboxylic acid amide.  
     
     
         6 . The preparation process of the aliphatic polyester formed item according to  claim 5  wherein the aliphatic carboxylic acid amide is one or more compounds selected from the group consisting of ethylenebiscaproamide, ethylenebislauramide, ethylenebisoleamide, m-xylylenebisstearamide and m-xylylenebis-12-hydroxystearamide.  
     
     
         7 . The preparation process of the aliphatic polyester formed item according to  claim 3  wherein the aliphatic polyester is a copolymer having a polylactic acid block and a polybutylene succinate block.  
     
     
         8 . The preparation process of the aliphatic polyester formed item according to  claim 7  wherein the transparent nucleating agent is one or more compounds selected from the group consisting of palmitamide, steramide, erucamide, beheamide, ricinolamide, hydroxystearamide, N-oleylpalmitamide, N-stearylerucamide, ethylenebiscapramide, ethylenebislauramide, ethylenebisoleamide, m-xylylenebisstearamide, m-xylylenebis-12-hydroxystearamide, sodium stearate, potassium stearate, zinc stearate, calcium montanate, ethylene glycol distearate and stearyl alcohol.  
     
     
         9 . The preparation process of the aliphatic polyester formed item according to  claim 4  wherein the aliphatic polyester is polybutylene succinate.  
     
     
         10 . The preparation process of the aliphatic polyester formed item according to  claim 9  wherein the transparent nucleating agent is one or more compounds selected from the group consisting of palmitamide, steramide, erucamide, beheamide, ricinolamide, hydroxystearamide, N-oleylpalmitamide, N-stearylerucamide, ethylenebiscapramide, ethylenebislauramide, ethylenebisoleamide, m-xylylenebisstearamide, m-xylylenebis-12-hydroxystearamide, sodium stearate, potassium stearate, zinc stearate, calcium montanate, ethylene glycol distearate and stearyl alcohol.  
     
     
         11 . The preparation process of the aliphatic polyester formed item according to  claim 1  wherein the heat treatment comprises melting the aliphatic polyester composition, successively filling said composition into a mold maintained in a temperature range from the crystallization initiating temperature to the crystallization terminating temperature of said aliphatic polyester composition, and crystallizing said composition in the mold.  
     
     
         12 . The preparation process of the aliphatic polyester formed item according to  claim 1  wherein the heat treatment comprises cooling and solidifying the molten aliphatic polyester composition in a mold to obtain an amorphous formed item, and successively crystallizing said formed item in a temperature range from the glass transition point to the melting point of said composition.  
     
     
         13 . A formed item of the aliphatic polyester obtained by the preparation process according to  claim 1 .  
     
     
         14 . A formed item of the aliphatic polyester obtained by the preparation process according to  claim 2 .  
     
     
         15 . The formed item of the aliphatic polyester according to  claim 13  wherein the transparency is 30% or less in a Haze value for 1 mm thickness and crystallinity is 10% or more in crystallization degree.  
     
     
         16 . The formed item of the aliphatic polyester according to  claim 14  wherein the transparency is 30% or less in a Haze value for 1 mm thickness and crystallinity is 10% or more in crystallization degree.  
     
     
         17 . A formed item of the aliphatic polyester comprising an aliphatic polyester and one or more transparent nucleating agents selected from the group consisting of an aliphatic carboxylic acid amide, an aliphatic carboxylic acid salt, an aliphatic alcohol and an aliphatic carboxylic acid ester having a melting point of 40-300° C., and having transparency and crystallinity in combination.  
     
     
         18 . The formed item of the aliphatic polyester according to  claim 17  wherein the ratio of the transparent nucleating agent to aliphatic polyester is 0.1-10 parts by weight of the transparent nucleating agent for 100 parts by weight of aliphatic polyester.  
     
     
         19 . The formed item of the aliphatic polyester according to  claim 18  wherein the aliphatic polyester is polylactic acid.  
     
     
         20 . The formed item of the aliphatic polyester according to  claim 18  wherein the aliphatic polyester is a copolymer having a polylactic acid block and a polybutylene succinate block and/or polybutylene succinate.  
     
     
         21 . The formed item according to  claim 19  wherein the transparent nucleating agent is an aliphatic carboxylic acid amide.  
     
     
         22 . The formed item according to  claim 21  wherein the aliphatic carboxylic acid amide is one or more compounds selected from the group consisting of etheylenebiscapramide, ethylenebislauramide, ethylenebisoleamide, m-xylylenebisstearamide and m-xylylenebis-12-hydroxystearamide.  
     
     
         23 . The formed item according to  claim 20  wherein the transparent nucleating agent is one or more compounds selected from the group consisting of palmitamide, stearamide, erucamide, behenamide, ricinolamide, hydroxysteramide, N-oleylpalmitamide, N-stearylerucamide, ethylenebiscapramide, ethylenebislauramidem ethylenebisoleamide, m-xylylenebisstearamide, m-xylylenebis-12-hydroxystearamide, sodium stearate, potassium stearate, zinc stearate calcium montanate, ethylene glycol distearate and stearyl alcohol.  
     
     
         24 . The formed item according to  claim 17  wherein the transparency is 30% or less in a Haze value for 1 mm thickness and crystallinity is 10% or more in crystallization degree.  
     
     
         25 . A process for using one or more compounds for a transparent nucleating agent of polylactic acid, the compounds being selected from the group consisting of ethylenebiscapramide, ethylenebislauramide, ethylenebisoleamide, m-xylylenebisstearamide and m-xylylenebis-12-hydroxystearamide.  
     
     
         26 . A process for using one or more compounds for a transparent nucleating agent of a copolymer having a polylactic acid block and a polybutylene succinate block and/or a polybutylene succinate, the compounds being selected from the group consisting of palmitamide, steramide, erucamide, behenamide, ricinolamide, hydroxystearamide, N-oleylpalmitamide, N-stearylerucamide, ethylenebiscapramide, ethylenebislauramidem ethylenebisoleamide, m-xylylenebisstearamide, m-xylylenebis-12-hydroxystearamide, sodium oleate, sodium stearate, potassium stearate, zinc stearate, calcium montanate, ethylene glycol disteryl alcohol.