EP-4740058-A1 - COMPOSITION OF CELLULOSE ESTER AND DERIVATIVES OF CARDANOL AND RELATED ARTICLE COMPRISING IT

Abstract

Composition comprising a cellulose ester and a plasticising agent, wherein said plasticising agent comprises at least one tri-epoxidised derivative of cardanol having the following structural formula ( Formula I ) : wherein R is selected from -OH and -OCOR 1 , where R 1 is -H or a linear or branched alkyl C 1 -C 10 .

Inventors

• PIANTANIDA, Etienne

Assignees

• Luxottica S.r.l.

Dates

Publication Date

20260513

Application Date

20240626

Claims (1)

1. 1. Composition comprising a cellulose ester and a plasticising agent, wherein said plasticising agent comprises at least one tri-epoxidised derivative of cardanol having the following structural formula ( Formula I ) : ( Formula I ) , wherein R is selected from -OH and -OCORi, where Ri is - H or a linear or branched alkyl Ci-Cio. 2) Composition according to claim 1, wherein Ri is a linear or branched alkyl C1-C4. 3) Composition according to claim 1 or 2, wherein R is -OCORi, where Ri is -H, methyl, propyl or butyl. 4) Composition according to claim 3, wherein R is -OCORi, where Ri is methyl. 5) Composition according to any of claims 1 to 4, wherein said cellulose ester is an aliphatic C1-C10 cellulose ester. 6) Composition according to claim 5, wherein said aliphatic C1-C10 cellulose ester is selected from: cellulose acetate, cellulose propionate, cellulose butyrate and combinations thereof. 7) Composition according to claim 6, wherein said cellulose ester is cellulose acetate. 8) Composition according to anyone of claims from 1 to 7, wherein said cellulose ester and said plasticising agent are present in a weight ratio within the range of from 90:10 to 55:45, preferably within a range of from 80:20 to 60:40, more preferably within a range of from 75:25 to 65:35. 9) Article comprising a composition of cellulose ester comprising: - at least one cellulose ester; - a plasticizing agent comprising at least one triepoxidised derivative of cardanol having the following structural formula (Formula I) : ( Formula I ) , wherein R is selected from -OH and -OCORi, where Ri is - H or a linear or branched alkyl Ci-Cio. 10) Article according to claim 9, wherein Ri is a linear or branched alkyl C1-C4. 11) Article according to claim 9 or 10, wherein R is -OCORi, where Ri is -H, methyl, propyl or butyl. 12) Article according to claim 11, wherein R is - OCORi, where Ri is methyl. 13) Article according to anyone of claims 9 to 12, said article being a spectacle frame.

Description

COMPOS ITION OF CELLULOSE ESTER AND DERIVATIVES OF CARDANOL AND RELATED ARTICLE COMPRIS ING IT Field of the invention The present invention falls within the field of cellulose ester-based plastic materials . In particular, the present invention relates to a cellulose ester composition comprising a cellulose ester and a plasticising agent , wherein said plasticising agent comprises at least one cardanol derivative . Furthermore , the present invention relates to an article comprising the aforementioned cellulose ester composition, namely a spectacle frame . Technical background of the invention Cellulose esters are generally considered to be more environmentally friendly polymers than polymers of fossil origin because they are recyclable , degradable and derived from renewable sources . Nevertheless , the use of cellulose esters in plastic compositions has its limitations due to their processing di f ficulty . In many cases , cellulose esters are di f ficult to process in the molten state because the softening temperature of the cellulose ester is too close to its degradation temperature . To overcome this problem, it is known to use plasticising agents , which reduce the softening temperature of the cellulose ester and increase its Melt Flow Index (MFI ) , which makes the molten cellulose ester processable and, for example , compatible with inj ection moulding techniques . The plasticiser also has an ef fect on the mechanical properties of the material , decreasing the modulus of elasticity and increasing ultimate elongation and impact resistance . Among cellulose esters , cellulose acetate , a polymer obtained by acetylation of cellulose , is well known . Its main area of use is in eyewear : frames are obtained by milling cellulose acetate tablets . Other areas of use include , for example , fashion accessories , costume j ewellery, membranes and cigarette filters . The most commonly used plasticisers to improve the characteristics of cellulose acetate are diethyl phthalate ( DEP ) and acetyl triethyl citrate (ATEC ) , followed by other derivatives of citric acid and glycerol . It has been observed that the introduction of these plasticisers into a polymer matrix of cellulose acetate in a relatively high quantity ( 25-35% by mass with respect to the mass of the polymer matrix ) and with a relatively low molecular weight (<400 g/mol ) is followed by a reduction in the concentration of the plasticiser over time due to its di f fusivity in the polymer matrix, resulting in a degradation of the thermomechanical properties of the polymer material and a lower durability of the material itsel f , as well as the resulting pollution of the environment . Furthermore , DEP has a strong af finity for polycarbonate , a material typically used in the production of spectacle lenses . This prevents the use of polycarbonate lenses in DEP-plasticised cellulose acetate frames. The plasticiser ATEC is a derivative of citric acid. Compared to DEP, ATEC has the advantage of remaining longer in the cellulose acetate matrix, having a lower diffusivity coefficient. At the same time, however, ATEC has a lower plasticising efficiency than DEP: a higher amount of plasticiser must be used to achieve the same properties (roughly 28% to 32%) . Cardanol is a compound with the following structural formula: Cardanol can be obtained by vacuum distillation from cashew nut shell oil (Cashew Nut Shell Liquid - CNSL) . The oil is a mixture of at least four constituents, which differ in the degree of unsaturation of the side chain: saturated side chain (5-8 wt %) ; monounsaturated side chain (48-49 wt %) ; di-unsaturated side chain (16-17 wt %) ; tri-unsaturated side chain (29-30 wt The use of chemically modified cardanol as an internal plasticiser for cellulose esters is known in literature: Iji, M. et al. ; Mechanical and other characteristics of cellulose ester bonded with modified cardanol from cashew nut shells and additional aliphatic and aromatic components; Cellulose 2013, 20 (1) , 559-569. In this type of application, the modified cardanol is covalently bonded to the cellulose ester so as to obtain a crimped polymer with thermo-mechanical properties that differ from those of the corresponding non-crimped polymer. Covalently binding the plasticiser to the polymer, however, has the limitation of significantly reducing the plasticising effect as well as considerably complicating the industrial production of the material. The use of esterified and/or epoxidised cardanol compounds as external PVC plasticisers is also known, as reported in Briou, B.; Caillol, S.; Robin, J. -J.; Lapinte, V. ; Non-Endocrine Disruptor Effect for Cardanol Based Plasticizer Industrial Crops and Products, Volume 130, 2019, Pages 1-8. In view of the aforementioned state of the art, there is a need to find alternative plasticisers for cellulose esters that combine plas ticisation efficiency with low diffusivity and are not toxic to humans or pollutants for the