Resin composition, molded article, and production methods thereof

Abstract

There are provided a resin composition comprising a polylactic acid which (i) comprises a poly-L-lactic acid (component B-1) and a poly-D-lactic acid (component B-4), (ii) has a weight ratio of the component B-1 to the component B-4 (component B-1/component B-4) of 10/90 to 90/10, and (iii) shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 20%; a molded article of the resin composition; and methods for producing the resin composition and the molded article.

1 . A resin composition comprising 100 parts by weight of thermoplastic resin (component A) and 1 to 200 parts by weight of polylactic acid (component B), wherein
 (i) the component B comprises a polylactic acid (component B-1) that comprises 90 to 100 mol % of L-lactic acid unit and 0 to 10 mol % of D-lactic acid unit and/or units other than lactic acid and a polylactic acid (component B-4) that comprises 90 to 100 mol % of D-lactic acid unit and 0 to 10 mol % of L-lactic acid unit and/or units other than lactic acid,   (ii) the weight ratio of the component B-1 to component B-4 (component B-1/component B-4) in the component B is within a range of 10/90 to 90/10, and   (iii) the component B in the resin composition shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 20%.   
     
     
         2 . The composition of  claim 1 , wherein the component A is at least one resin selected from the group consisting of an aromatic polycarbonate resin, a polyester resin, a polyolefin resin and a styrene resin. 
     
     
         3 . The composition of  claim 1 , wherein the component A is an aromatic polycarbonate resin. 
     
     
         4 . The composition of  claim 3 , wherein the aromatic polycarbonate resin is bisphenol A based polycarbonate resin. 
     
     
         5 . The composition of  claim 1 , wherein the component B in the resin composition shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 70%. 
     
     
         6 . The composition of  claim 1 , comprising 0.01 to 5 parts by weight of crystal nucleating agent (component C) based on 100 parts by weight of the component B. 
     
     
         7 . The composition of  claim 6 , wherein the crystal nucleating agent (component C) is talc. 
     
     
         8 . The composition of  claim 1 , comprising 0.3 to 200 parts by weight of inorganic filler (component D) based on 100 parts by weight of the component A. 
     
     
         9 . The composition of  claim 1 , comprising 0.01 to 5 parts by weight of terminal blocking agent (component E) based on 100 parts by weight of the component B. 
     
     
         10 . A method for producing a resin composition by melt-kneading 100 parts by weight of thermoplastic resin (component A) and 1 to 200 parts by weight of polylactic acid (component B), wherein
 (i) the component B comprises a polylactic acid (component B-1) that comprises 90 to 100 mol % of L-lactic acid unit and 0 to 10 mol % of D-lactic acid unit and/or units other than lactic acid and a polylactic acid (component B-4) that comprises 90 to 100 mol % of D-lactic acid unit and 0 to 10 mol % of L-lactic acid unit and/or units other than lactic acid,   (ii) the weight ratio of the component B-1 to component B-4 (component B-1/component B-4) in the component B is within a range of 10/90 to 90/10, and   (iii) the component B shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 20%.   
     
     
         11 . The method of  claim 10 , wherein the component B shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 70%. 
     
     
         12 . The method of  claim 10 , wherein the component B is obtained by melt-kneading the component B-1 and the component B-4 at 245 to 300° C. 
     
     
         13 . The method of  claim 10 , wherein melt-kneading is carried out in the presence of 0.01 to 5 parts by weight of crystal nucleating agent (component C) based on 100 parts by weight of the component B. 
     
     
         14 . The method of  claim 13 , wherein the component C is talc. 
     
     
         15 . The method of  claim 10 , wherein melt-kneading is carried out in the presence of 0.3 to 200 parts by weight of inorganic filler (component D) based on 100 parts by weight of the component A. 
     
     
         16 . The method of  claim 10 , wherein melt-kneading is carried out in the presence of 0.01 to 5 parts by weight of terminal blocking agent (component E) based on 100 parts by weight of the component B. 
     
     
         17 . A molded article comprising the composition of  claim 1 . 
     
     
         18 . The molded article of  claim 17 , which is an injection-molded article. 
     
     
         19 . The molded article of  claim 17 , which is an automobile part, an electric/electronic part, an electrical equipment exterior part, an office automation equipment exterior part or an optical disk substrate. 
     
     
         20 . A molded article comprising a polylactic acid (component B) that shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 20%. 
     
     
         21 . The molded article of  claim 20 , comprising a polylactic acid (component B) that shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 70%. 
     
     
         22 . The molded article of  claim 20 , wherein the component B comprises a polylactic acid (component B-1) that comprises 90 to 100 mol % of L-lactic acid unit and 0 to 10 mol % of D-lactic acid unit and/or units other than lactic acid and a polylactic acid (component B-4) that comprises 90 to 100 mol % of D-lactic acid unit and 0 to 10 mol % of L-lactic acid unit and/or units other than lactic acid, and the weight ratio of the component B-1 to the component B-4 (component B-1/component B-4) is within a range of 10/90 to 90/10. 
     
     
         23 . The molded article of  claim 20 , comprising 0.01 to 5 parts by weight of crystal nucleating agent (component C) based on 100 parts by weight of the component B. 
     
     
         24 . The molded article of  claim 23 , wherein the component C is talc. 
     
     
         25 . The molded article of  claim 20 , which is in a block shape. 
     
     
         26 . The molded article of  claim 20 , comprising 0.3 to 200 parts by weight of inorganic filler (component D) based on 100 parts by weight of the component B. 
     
     
         27 . The molded article of  claim 20 , comprising 0.01 to 5 parts by weight of terminal blocking agent (component E) based on 100 parts by weight of the component B. 
     
     
         28 . The molded article of  claim 20 , which is an automobile part, an electric/electronic part, an electrical equipment exterior part, an office automation equipment exterior part or an optical disk substrate. 
     
     
         29 . A method for producing a molded article by molding pellets comprising a polylactic acid (component B) that shows a proportion of melt peaks at 195° C. or higher to all melt peaks in a temperature rising process in measurement by a differential scanning calorimeter (DSC) of at least 70%. 
     
     
         30 . The method of  claim 29 , wherein the component B comprises a polylactic acid (component B-1) that comprises 90 to 100 mol % of L-lactic acid unit and 0 to 10 mol % of D-lactic acid unit and/or units other than lactic acid and a polylactic acid (component B-4) that comprises 90 to 100 mol % of D-lactic acid unit and 0 to 10 mol % of L-lactic acid unit and/or units other than lactic acid, and the weight ratio of the component B-1 to the component B-4 (component B-1/component B-4) is within a range of 10/90 to 90/10. 
     
     
         31 . The method of  claim 29 , wherein the component B is a polylactic acid obtained by kneading the component B-1 and the component B-4 at 245 to 300° C. 
     
     
         32 . The method of  claim 29 , wherein the pellets comprise 0.01 to 5 parts by weight of crystal nucleating agent (component C) based on 100 parts by weight of the component B. 
     
     
         33 . The method of  claim 32 , wherein the component C is talc. 
     
     
         34 . The method of  claim 29 , wherein the pellets comprise 0.3 to 200 parts by weight of inorganic filler (component D) based on 100 parts by weight of the component B. 
     
     
         35 . The method of  claim 29 , wherein the pellets comprise 0.01 to 5 parts by weight of terminal blocking agent (component E) based on 100 parts by weight of the component B. 
     
     
         36 . The method of  claim 29 , wherein molding is carried out by injection molding, extrusion, heat molding, blow molding or foam molding. 
     
     
         37 . The method of  claim 36 , wherein injection molding is carried out at a mold temperature of 80 to 130° C. 
     
     
         38 . The method of  claim 36 , wherein a resin obtained by melting the pellets at 200° C. or higher is extruded. 
     
     
         39 . The method of  claim 38 , wherein an obtained molded article is heat-treated within a temperature range of its crystallization temperature to melting point. 
     
     
         40 . The method of  claim 36 , wherein after a resin obtained by melting the pellets at 200° C. or higher is extruded through a slit die to obtain a sheet-shaped extruded article, the extruded article is first heated to its glass transition temperature or higher and then heat-molded. 
     
     
         41 . The method of  claim 40 , wherein an obtained molded article is heat-treated within a temperature range of its crystallization temperature to melting point. 
     
     
         42 . The method of  claim 36 , wherein after a resin obtained by melting the pellets at 200° C. or higher is molded to form a parison, the parison is first heated to its glass transition temperature or higher and then blow-molded. 
     
     
         43 . The method of  claim 42 , wherein an obtained molded article is heat-treated within a temperature range of its crystallization temperature to melting point. 
     
     
         44 . The method of  claim 36 , wherein a resin obtained by melting the pellets at 160° C. or higher is foam-molded. 
     
     
         45 . The method of  claim 44 , wherein an obtained molded article is heat-treated within a temperature range of its crystallization temperature to melting point.