BIODEGRADABLE FILM

Abstract

This invention relates to a biodegradable film which is particularly suitable for the manufacture of packaging and is also characterised by high level mechanical properties.

Claims

1. A film made by a composition comprising: i) 30-95% by weight, with respect to the sum of components i.-v., of at least one polyester comprising: a) a dicarboxylic component containing with respect to the total dicarboxylic component: a1) 35-70% by moles of units deriving from at least one aromatic dicarboxylic acid; a2) 65-30% by moles of units deriving from at least one saturated aliphatic dicarboxylic acid; a3) 0-5% by moles of units deriving from at least one unsaturated aliphatic dicarboxylic acid; b) a diol component comprising with respect to the total diol component: b1) 95-100% by moles of units deriving from at least one saturated aliphatic diol; b2) 0-5% by moles of units deriving from at least one unsaturated aliphatic diol; ii) 0.1-50% by weight, with respect to the sum of components i.-v., of at least one polymer of natural origin, iii) 1-40% by weight, with respect to the sum of components i.-v., of at least one polyhydroxy alkanoate; iv) 0-15% by weight, with respect to the sum of components i.-v., of at least one inorganic filler; v) 0-5% by weight, with respect to the sum of components i.-v., of at least one crosslinking agent and/or chain extender comprising at least one compound having two and/or multiple functional groups including isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride divinylether groups and mixtures thereof, wherein said film is characterized by a tear resistance in the machine direction of >100 N/mm, determined according to ASTM D1922 (at 23° C. and 55% relative humidity).

2. The film according to claim 1, in which the aromatic dicarboxylic acids in component a1 of polyester i. is selected from aromatic dicarboxylic acids of the phthalic acid type terephthalic acid, isophthalic acid, and heterocyclic dicarboxylic aromatic compounds, their esters, salts and mixtures thereof.

3. The film according to claim 1, in which the saturated aliphatic dicarboxylic acid of component a2 of the polyester i. comprises a mixture comprising at least 50% by moles of at least one acid selected from succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid, their C.sub.1-C.sub.24 C.sub.1-C.sub.4 alkyl esters and mixtures thereof.

4. The film according to claim 1, in which the saturated aliphatic dicarboxylic acids in said component a2 are selected from adipic acid and azelaic acid or mixtures thereof.

5. The film according to claim 1, in which the aliphatic diols in component b1 of polyester i. comprises at least 50% by moles of one or more diols selected from 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol.

6. The film according to claim 1, in which the polymer of natural origin ii. is starch.

7. The film according to claim 1, biodegradable in accordance with standard EN 13432.

8. Packaging comprising the film according to claim 1.

9. Packaging according to claim 8, selected from bags for the carrying of goods and bags for food packaging.

10. Bags for the carrying of goods according to claim 9.

11. Bags for fruit and vegetables comprising the film according to claim 1.

12. The film according to claim 2, in which the saturated aliphatic dicarboxylic acid of component a2 of the polyester i. comprises a mixture comprising at least 50% by moles of at least one acid selected from succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid, their C.sub.1-C.sub.24 C.sub.1-C.sub.4 alkyl esters and mixtures thereof.

13. The film according to claim 2, in which the saturated aliphatic dicarboxylic acids in said component a2 are selected from adipic acid and azelaic acid or mixtures thereof.

14. The film according to claim 3, in which the saturated aliphatic dicarboxylic acids in said component a2 are selected from adipic acid and azelaic acid or mixtures thereof.

15. The film according to claim 2, in which the aliphatic diols in component b1 of polyester i. comprises at least 50% by moles of one or more diols selected from 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol.

16. The film according to claim 3, in which the aliphatic diols in component b1 of polyester i. comprises at least 50% by moles of one or more diols selected from 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol.

17. The film according to claim 4, in which the aliphatic diols in component b1 of polyester i. comprises at least 50% by moles of one or more diols selected from 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol.

18. The film according to claim 2, in which the polymer of natural origin ii. is starch.

19. The film according to claim 3, in which the polymer of natural origin ii. is starch.

20. The film according to claim 4, in which the polymer of natural origin ii. is starch.

21. The film according to claim 1, in which the saturated aliphatic dicarboxylic acid of component a2 of the polyester i. comprises a mixture of adipic acid and azelaic acid.

22. The film according to claim 21, wherein the mixture comprises azelaic acid in a quantity of between 5 and 40% by moles with respect to the sum of the adipic acid and the azelaic acid.

23. The film according to claim 1, in which the polymer of natural origin of point ii is in a quantity of between 5-40% by weight, with respect to the sum of components i.-v.

24. The film according to claim 1, in which the at least one polyhydroxyalkanoate of point iii is in a quantity of 1-30% by weight, with respect to the sum of components i.-v.

Description

EXAMPLES

[0096] i-1. Poly (1,4-butylene adipate-co-1,4-butylene azelate-co-1,4-butylene terephthalate) with 49% mol of 1,4-butylene terephthalate units and with 30% mol of azelaic acid units with respect to the sum of azelaic acid and adipic acid units. MFR 6.7/10 min (at 190° C., 2.16 kg) and 33 meq/kg amount terminal acid groups.

[0097] i-2. Poly (1,4-butylene adipate-co-1,4-butylene azelate-co-1,4-butylene terephthalate) with 48.5% mol of 1,4-butylene terephthalate units and with 20% mol of azelaic acid units with respect to the sum of azelaic acid and adipic acid units. MFR 6.6/10 min (at 190° C., 2.16 kg) and 35 meq/kg amount terminal acid groups.

[0098] i-3. Poly (1,4-butylene adipate-co-1,4-butylene azelate-co-1,4-butylene terephthalate) with 48% mol of 1,4-butylene terephthalate units and with 13% mol of azelaic acid units with respect to the sum of azelaic acid and adipic acid units. MFR 6.2/10 min (at 190° C., 2.16 kg) and 48 meq/kg amount terminal acid groups.

[0099] i-4. Poly (1,4-butylene adipate-co-1,4-butylene azelate-co-1,4-butylene terephthalate) with 48% mol of 1,4-butylene terephthalate units and with 6% mol of azelaic acid units with respect to the sum of azelaic acid and adipic acid units. MFR 5.5/10 min (at 190° C., 2.16 kg) and 49 meq/kg amount terminal acid groups.

[0100] i-5. Poly (1,4-butylene adipate-co-1,4-butylene terephthalate) with 47% mol of 1,4-butylene terephthalate units. MFR 6.9/10 min (at 190° C., 2.16 kg) and 42 meq/kg amount terminal acid groups.

[0101] iii. Ingeo 4043D polylactic acid (“PLA”). MFR 3.0/10 mm (at 190° C., 2.16 kg).

[0102] ii. Thermoplastic maize starch.

[0103] iv. Calcium carbonate Cacitec M/2 by Mineraria Sacilese.

[0104] v-1. Almatex PD4440 styrene-glycidyl ether-methylmetacrilate copolymer from Anderson Development Company.

[0105] v-2. HMV-15CA Carbodilite from Nisshinbo Chemical Inc..

TABLE-US-00001 Film Component (wt %) thickness i-1 i-2 i-3 i-4 i-5 ii iii iv v-1 v-2 (μm) 1 61.00 — — — — 30.35 8.30 — 0.15 0.20 20 2 (comparative) — — — — 61.00 30.35 8.30 — 0.15 0.20 20 3 57.80 — — — — 37.75 4.00 — 0.20 0.25 20 4 — 57.80 — — — 37.75 4.00 — 0.20 0.25 20 5 — — 57.80 — — 37.75 4.00 — 0.20 0.25 20 6 — — — 57.80 — 37.75 4.00 — 0.20 0.25 20 7 (comparative) — — — — 57.80 37.75 4.00 — 0.20 0.25 20 8 54.70 — — — — 40.85 4.00 — 0.20 0.25 20 9 (comparative) — — — — 54.70 40.85 4.00 — 0.20 0.25 20 10 49.00 — — — — 46.55 4.00 — 0.20 0.25 20 11 (comparative)  — — — — 49.00 46.55 4.00 — 0.20 0.25 20 12 56.00 — — — — 30.35 8.30 5 0.15 0.20 20 13 57.80 — — — — 37.75 4.00 — 0.20 0.25 25 14 57.80 — — — — 37.75 4.00 — 0.20 0.25 14

[0106] The compositions indicated in Table 1 were fed to a co-rotating twin extruder (APV2030) with L/D=40 and diameter 30 mm provided with 15 heating zones. The extrusion parameters are as follows: [0107] rpm: 250 [0108] flow rate: 9 Kg/h [0109] thermal profile: 30-90-160-200x10-165x3° C. [0110] degassing in L/D=30

[0111] The compositions of Table 1 were filmed on a 40 mm Ghioldi, die gap=0.9 mm, flow rate 24 kg/h and blow-up ratio=3.2 to obtain film with a thickness of 25 μm (draw-down ratio=11.4), 20 μm (draw-down ratio=14.3) and 14 μm (draw-down ratio=20.4).

[0112] The films were the subjected to mechanical characterization according to the standard ASTM D882 (traction at 23° C. and 55% relative humidity, Vo=50 mm/mmn) and also according to ASTM D1922 (tearing resistance at 23° C. and 55%˜ relative humidity).

[0113] Results are presented in Table 2 below.

TABLE-US-00002 TABLE 2 ASTM D1922 (23° C. - 55% RH ) ASTM D882 Machine (23° C. 55% RH - Vo 50 mm/min) Direction Example σ.sub.b (MPa) ε.sub.b (%) E (MPa) En.sub.b (kJ/m.sup.2) Force (N/mm) 1 29.0 241 307 2491 232 2 (comparative) 31.0 262 362 2930 72 3 26.8 372 221 3706 191 4 26.5 340 231 3367 166 5 26.0 328 240 3308 125 6 25.1 310 233 2897 105 7 (comparative) 24.3 278 212 2538 95 8 24.3 295 220 2754 180 9 (comparative) 23.1 259 257 2318 91 10 21.9 228 296 2030 143 11 (comparative)  20.9 206 275 1727 67 12 24 305 367 2794 196 13 24.9 385 214 3629 198 14 25.6 253 238 2538 132