US 20090234042A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2009/0234042 A1 Luinstra (43) Pub. Date: Sep. 17, 2009 (54) TRANSPARENT BLENDS OF (86). PCT No.: PCT/EP07/53759 POLY PROPYLENE CARBONATE S371 (c)(1), (2), (4) Date: Oct. 23, 2008 (75) Inventor: Gerrit Luinstra, Mannheim (DE) (30) Foreign Application Priority Data Correspondence Address: Apr.p 27,s 2006 (EP) .................................. O61132O15 CONNOLLY BOVE LODGE & HUTZ, LLP Mar. 27, 2007 (EP) .................................. O7104484.6 PO BOX 2207 Publication Classification WILMINGTON, DE 19899 (US) (51) Int. Cl. COSL 69/00 (2006.01) (73) Assignee: BASF SE, Ludwigshafen (JP) (52) U.S. Cl. ......................................... 523/105:524/502 (57) ABSTRACT (21) Appl. No.: 12/298,251 This invention is directed to transparent blends of polypropy lene carbonate with poly lactide and/or polyhydroxyal kanoates, to a process for the preparation of said blends as (22) PCT Filed: Apr. 18, 2007 well as the use of said blends. US 2009/0234042 A1 Sep. 17, 2009 TRANSPARENT BLENDS OF goods (e.g. Vegetables, fruits, meat) or to uniformly dying at POLY PROPYLENE CARBONATE low effort and costs. We thus set out to find blend components for polypropylene carbonate to improve the glass temperature and/or young modulus and to keep the excellent transparency 0001. This invention is directed to transparent blends of in the resulting materials. polypropylene carbonate with polylactide and/or polyhy 0007 Surprisingly, it is found that a transparent polypro droxyalkanoates, to a process for the preparation of said pylene carbonate (PPC) blend is formed by blending it with blends as well as the use of said blends. PLA (polylactid acid) independently of the ratio of the two 0002 High molecular weight Polypropylencarbonate components (PLA and PPC) in the blend. (PPC) is a thermoplastic, amorphous (transparent) material 0008. Yet in another embodiment of this invention, trans with a glass temperature in the range of 25 to 45° C. Latter is parent blends of polypropylene carbonate and PHB(V) are depending on the carbonate linkage percentage and the pres prepared, wherein the maximum amount of PHB(V) is not ence and amount of plasticizers like cyclic propylene carbon exceeding 15 parts by weight of a total of 100 in the sum with ate, which is a typical thermal decomposition product and/or polypropylene carbonate. This is very Surprising and favor side product of the synthesis. This means that the softening able for the properties of the blend. point of the polypropylene carbonate is usually at room or 0009. In addition, the blends according to the invention body temperature. This is disadvantageous for some applica have a higher glass temperature than the starting material tions in for example packaging sector: container prepared PPC. Furthermore, we found that the elastic modulus of said from polypropylene carbonate through injection or blow blends could be improved without losing the transparency. moulding will loose their shape inside a closed car on a Sunny The resulting blends can be processed using standard meth day in the Sun. In addition, granulate of polypropylene car ods including injection and blow moulding and are Suitable bonate tend to clog together at ambient temperature. As a for applications in packaging, play (toys, recreational), consequence, the transport in form of the usual pellets from hygiene (household) and medical, construction, sporting and manufacturer to customers may resultina Sticky block, which art SectOr. cannot be handled by standard equipment. As a result addi tional costs arise, for example for necessary milling or melt Details ing equipment. 0003. The above situation is unfavourable for the applica (0010. The transparent blends of PPC comprise the follow tion of polypropylene carbonate as a thermoplastic material. ing components wherein the sum of the parts of PPC and PLA An increase in the glass temperature and young modulus of or PHB are 100 parts by weight the thermoplastic material would improve the properties with a) a first embodiment: respect to application purposes and processing. The glass 0011 (i) 1-99 parts by weight of polypropylencarbonate temperature of a polymeric material can for example be having a molecular weight (Mn) between 30,000 and increased through the formation of blends with other materi 5,000,000 Da, als including with other polymers. 0012 (ii) 99-1 parts by weight of polylactid, 0004 Blends of polypropylene carbonate are known, 0013 (iii) 0.1-25 parts of an additional component that is however, they are all non-transparent as the result of a non known to function as an antioxidant, a flame retardant, a compatibility. This is expected, since different polymers tend filler, a (metal) complexing agent, a plasticizer or process to be immiscible. This has been explained by for example the ing aid, pigment, dye, brightener and/or antistatic agent; differences in solubility parameter Van Krevelen, Chapter 0014. The first embodiment comprises preferably: 7.: from a theoretical point of view, the solubility parameter 00.15 (i) 10-90 parts by weight of polypropylencarbonate of two components have to be identical within 0.1 (J/cm)'. having a molecular weight (Mn) between 30,000 and This is rarely the case, and it is thus to be expected that 50,000 Da, polymers in general are immiscible as is observed for the 0016 (ii) 90-10 parts by weight of polylactid, opaque blends of polypropylene carbonate with SAN, PS, PP, 0017 (iii) 0.5-15 parts of an additional component that is PMMA (see examples). E.g. U.S. Pat. No. 4,912,149 known to function as an antioxidant, a flame retardant, a describes non-transparent blends of polypropylene carbonate filler, a (metal) complexing agent, a plasticizer or process and PVC. ing aid, pigment, dye, brightener and/or antistatic agent; 0005 Blends of polyhydroxybutyrate (PHB) or polyhy droxybutyrate-covalerate (PHBV) and polypropylene car O bonate are reported in U.S. Pat. No. 6,576,694. The reported b) a second embodiment: blends are, however, non transparent as expected on account 0018 (i) 85-99 parts by weight of polypropylencarbonate of the different solubility parameter as explained above. The having a molecular weight (Mn) between 30,000 and reported blends consist of 30-70 parts of polypropylene car 5,000,000 Da, bonate respectively 70-30 parts of polyhydroxyalkanoates. 0019 (ii) 15-1 parts by weight of polyhydroxyalkanoate, Blends like this were also reported in for example Gaodeng 0020 (iii) 0.1-25 parts of an additional component that is Xuexiao Huaxue Xuebao 2004, 25, 1145 (CA: 141:350588) known to function as an antioxidant, a flame retardant, a or Macromolecular symposia 2004, 210, 241, J. Appl. Chem. filler, a (metal) complexing agent, a plasticizer or process 2004,92,2514-21 or ibid 2003,90,4054-60. All these reports ing aid, pigment, dye, brightener or antistatic agent; are concerned about melting behavior of the PHB, but did not 0021. The second embodiment comprises preferably: find a transparent PPC based material. 0022 (i) 90-98 parts by weight of polypropylencarbonate, 0006. However, there are good reasons for the use of trans 0023 (ii) 10-2 parts by weight of polyhydroxybutyrate, parent materials. They provide appealing qualities in form of 0024 (iii) 0.5-15 parts of an additional component that is attractive design options, direct visual contact to packaged known to function as an an antioxidant, a flame retardant, a US 2009/0234042 A1 Sep. 17, 2009 filler, a (metal) complexing agent, a plasticizer or process and 100, most preferably between 2 and 10. The polypropy ing aid, pigment, dye, brightener or antistatic agent; lene carbonate may also contain up to 1% carbamate or urea O entities. c) a third embodiment comprising mixtures of the first and 0039 Polylactide (PLA) is semi-amorphous with a Tg of second embodiments: around 60° C. and useful in this invention. PLA is a commer 0025 (i) 5-97 parts by weight of polypropylencarbonate, cial available polymer that is based on Substantially enantio 0026 (iia) 80-2 parts by weight of polylactid, meric pure lactic acid (see Nature Works(R) von Cargill Dow). 0027 (iib) 15-1 parts by weight of polyhydroxyalkanoate, Lactic acid is preferentially obtained from an agricultural 0028 (iii) 0.5-15 parts of an additional component that is biological source like Sugar or starch in a fermentative pro known to function as an antioxidant, a flame retardant, a cess. Generally speaking any PLA with a Tg larger than 40° filler, a (metal) complexing agent, a plasticizer or process C. is useful in this invention. The molecular weights are ing aid, pigment, dye, brightener or antistatic agent; preferably in the range of number average Mn between 5,000 0029. The third embodiment comprises preferably: and 5,000,000 Da, preferably between 10,000 and 250,000 0030 (i) 30-97 parts by weight of polypropylencarbonate, Da, most preferably between 25,000 and 150,000 Da. PLA 0031 (iia) 60-2 parts by weight of polylactid, may have been treated prior to its application in this invention 0032 (iib) 10-1 parts by weight of polyhydroxybutyrate, with agents to improve its properties, e.g. like those men 0033 (iii) 0.5-15 parts of an additional component that is tioned by Sinclair R. G. in Pure & Appl. Chem. 1996, A33, known to function as an antioxidant, a flame retardant, a 585-97. filler, a (metal) complexing agent, a plasticizer or process 0040 Polyhydroxyalkanoates embrace preferably poly ing aid, pigment, dye, brightener or antistatic agent; hydroxybutyrate (PHB(V)), particularly preferred poly-3-hy O droxybutyrate (PHB) and polyhydroxybutyrate covaleriate d) a fourth embodiment preferably: (PHBV). Generally speaking, any crystalline PHB(V) is use 0034 (i) 20-80 parts by weight of polypropylencarbonate, ful in this invention when it improves the young modulus of PPC component blend.