vor 3 Jahren

Issue 03/2019

Highlights: Toys Injection Moulding Basics: Microplastics Mind the right terms Captured CO2

new series Bioplastic

new series Bioplastic Patents By: Barry Dean, Naperville, Illinois, USA U.S. Patent 10,087,305 (October 2, 2018): “Nucleated Crystallization of Poly(Trimethylene-2,5-Furandicarboxylate) (PTF) and Articles Made Therefrom”, Gordon Mark Cohen, Frederik Nederberg, Bhuma Rajagopalan, (E. I. DuPont De Nemours and Company. (Wilmington, DE USA) Ref: PCT WO2015/095466 EP The composition taught is a block copolymer consisting of a hard segment, poly(trimethylene-2,5-furandicarboxylate) and a soft segment, 2,5-furan dicarboxylate based poly(alkylene ether glycol). A critical teaching is the use of a nucleating agent, a neutralized carboxylic acid salt or trisodium phosphate, for promoting crystallization of the hard segment from the melt which is key for the injection molding process cycle time. The level of nucleating agent is 1 – 2.5 weight % The ratio of hard segment to soft segment will influence bulk mechanical properties such as modulus, impact strength and compressive strength. This section highlights recently granted patents that are relevant to the specific theme/focus of the Bioplastics Magazine issue. The information offered is intended to acquaint the reader with a sampling of know-how being developed to enable growth of the bioplastics markets. The five patents cited demonstrate compositions and process for renewable/ biodegradable injection moldable compositions. Key for injection molding are compositions that deliver bulk properties in the final article but also must offer fast cycle times for the production of the molded article. U.S. Patent 9,914,831 (March 13, 2018): ”Injection Molded Article”, Maximillian Lehenmeier, Gabriel Skupin, Martin Bussmann , (BASF SE, Ludwigshafen DE) Ref: PCT WO2015/169660 This patent teaches an injection molding composition exhibiting an HDT of 80 – 105 C with balance of Charpy impact strength and modulus to allow for thin wall structures. The multi-component composition consists of 47 – 59 weight % of polyester derived from succinic acid and a C6 – C20 aliphatic acid with 1,3-propanediol and 1,4-butanediol; 3- 14 weight % of polyester derived from C6 – C20 aliphatic acid and terephthalic acid with 1,3-propanediol and 1,4-butanediol; 15 – 24 weight % of polylactic acid and 10 – 35 % mineral filler(eg talc). Chain extender is used in the polyesters to control molecular weight. The compositions illustrated are tailored to control HDT, modulus and impact based on application as well as injection molding cycle time and structure dimensional stability. Preferred applications are coffee capsules, coffee cup lids and tableware. The biodegradability/compostability of the injection molded article is determined by the polymer matrices selection. 50 bioplastics MAGAZINE [03/19] Vol. 14

U.S. Patent 10,189,989 (January 29, 2019): “Polyester Mixture Including Polyethylene-2,5-Furandicarboxylate”, Anne K. Moeller, Klan Molawi, Motomori Yamamato, (BASF SE) Ref: PCT WO2015/150141 This patent teaches poly(cyclohexylenedimethylene- 2,5-furandicarboxylate)(PCF) can be nucleated with poly(ethylene-2,5-furandicarboxylate). PCF is a semicrystalline polyester with a Tg of 86 – 87 C, Tm of 267 C and onset of recrystallization at 217 – 223 C. For the injection molding process a higher onset of recrystallization is important for both cycle time and dimensional stability. Other nucleating agents are shown to increase the onset of crystallization of PCF by 10 – 12 C while 1 weight % PEF is shown to increase the onset of nucleation of PCF to 243 C, an increase of 25 C relative to non-nucleated PCF. The patent also teaches that PEF can have nucleation benefits in other renewable polymers such as PBS and PBAT U. S. Patent 10,160,857 (December 25, 2018): “Thermoplastic Resin Composition and Molded Article Made Therefrom”, Chansu Kim, Kyunghae Lee, Jun Chwae, Mooho Lee, Kwangmyung Cho, (Samsung Electronics Ltd Korea) A thermoplastic composition based on a polylactic acid and a inorganic-organic particle tailored to improve impact strength and heat resistance is taught. The particle consists of an inorganic core and an organic coating layer on the core. Significant improvement in impact strength and heat resistance are illustrated when the inorganic-organic particle is based on organic coating layer that is a block copolymer for polycaprolactone and PLA. Lower impact strength and heat resistance are shown when the organic coating layer is either polycaprolactone or PLA or when the polycaprolactone/PLA layer is a copolymer and not a block copolymer. The inorganic particle diameter is less than 100 nm. The thermoplastic composition illustrated is 74 % by weight PLA, 20 % by weight inorganic-organic particle and the remainder is a plasticizer and nucleating agent. The inorganic-organic particle can be ranged from 5 – 40 weight % to tailor properties. The organic layer that is taught as a block copolymer of polycaprolactone and PLA is key to enabling the bulk composition to offer improved impact strength and heat resistance compared with the polylactic acid matrix. U.S. Patent 10,240,007 (March 29, 2019): “Shaped Polylactide Article and Method of Preparation”, Siebe Cornelis De Vos, Robert Edgar Haan, Geraldus Gerardus Johannes Schennink, (Purac Biochem BV Netherlands) Ref: PCT WO2016/102163 This patent teaches a method to maximize the formation of the stereocomplex(sc) crystallinity from mixtures of two enantiomers PLLA and PDLA. The method consists of mixing a first homopolylactide with an excess of a second homopolylactide where the first and second homopolylactide are poly-L-lactide(PLLA) or poly-D-lactide(PDLA). This mixing is done in the molten state and the pellets allowed to cool and crystallize as a blend of the sc-PLA. The pellet sc-PLA is blended with pellets of the first homolactide and melt processed into an article where the melt processing temperatures are above the melting points of the PLLA and PDLA(Tm= 175 C) but below that of the sc-PLA(Tm = 230 - 240 C). This method maintains the modulus, impact and elongation while providing an increase in bulk thermal performance via maximizing the sc-PLA. bioplastics MAGAZINE [03/19] Vol. 14 51

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