FLOWABILITY OF POLYCARBONATE COMPOSITIONS

Abstract

The present invention relates to the use of diglycerol esters for enhancing the flowability of transparent polycarbonate compositions. Melt viscosities and melt volume flow rates are improved. In addition, the diglycerol esters also exert a positive effect on the optical properties by increasing the transmission of the compositions and reducing the yellowness index.

Claims

1.-9. (canceled)

10. A method comprising enhancing the flowability of a transparent polycarbonate composition comprising utilizing at least one diglycerol ester in combination with at least one phosphate, wherein the transparent polycarbonate composition exhibits a transmission, determined to ISO 13468 for a thickness of 4 mm, of at least 88% in the range from 400 nm to 800 nm.

11. The method according to claim 10, wherein the diglycerol ester is an ester of formula (I) ##STR00004## where R═COC.sub.nH.sub.2n+1 and/or R═COR′, wherein n is an integer and R′ is a branched alkyl radical or a branched or unbranched alkenyl radical and C.sub.nH.sub.2n+1 is an aliphatic, saturated linear alkyl radical.

12. The method according to claim 11, wherein R═COC.sub.nH.sub.2n+1, wherein n is an integer of 6-24.

13. The method according to claim 10, wherein after addition of the diglycerol ester and the phosphate the polycarbonate composition comprises A) 20.0 wt % to 99.0 wt % of aromatic polycarbonate, B) 0.01 wt % to 3.0 wt % of diglycerol ester and C) 0.0 wt % to 1.0 wt % of heat stabilizer.

14. The method according to claim 10, wherein after addition of the diglycerol ester and the phosphate the polycarbonate composition comprises the constituents: A) 20.0 wt % to 99.0 wt % of aromatic polycarbonate, B) 0.01 wt % to 3.0 wt % of diglycerol ester and C) optionally up to 1.0 wt % of heat stabilizer and D) Doptionally up to 10.0 wt % of one or more further additives from the group of antioxidants, UV absorbers, IR absorbers, antistatics, optical brighteners, light-scattering agents, colorants from the group of organic pigments, inorganic pigments, carbon black and/or dyes and the inorganic fillers titanium dioxide, barium sulphate and/or additives for laser marking and D-2) 0.001 to 0.1 wt % of phosphate, wherein the components A) to E), including D-2), sum to 100 wt %.

15. The method according to claim 13, wherein the amount of the diglycerol ester is from 0.2 to 1.0 wt %.

16. The method according to claim 13, wherein the amount of the diglycerol ester is from 0.3 to 0.6 wt %.

17. The method according to claim 10, wherein the melt viscosity of the polycarbonate compositions determined to ISO 11443 is reduced by the diglycerol ester.

18. The method according to claim 10, wherein the at least one phosphate is triisooctyl phosphate.

Description

EXAMPLES

[0107] 1. Description of Raw Materials and Test Methods

[0108] The polycarbonate compositions described in the following examples were produced on a Berstorff ZE 25 extruder at a throughput of 10 kg/h by compounding. The melt temperature was 275° C.

[0109] Component A-1: linear polycarbonate based ©n bisphenol A, having a melt volume flow rate MVR of 12.5 cm.sup.3/10 min (to ISO 1133 at a test temperature of 300° C. and 1.2 kg loading) and comprising 250 ppm of triphenylphosphine as component C (heat stabilizer), produced by addition via a side-arm extruder.

[0110] Component A-2: pulverulent linear polycarbonate based on bisphenol A and having a melt volume flow rate MVR of 6 cm.sup.3/10 mm (to ISO 1133 at a test temperature of 300° C. and 1.2 kg loading).

[0111] Component A-3: UV-protected BPA polycarbonate (Makrolon® AL 2447) from Bayer MaterialScience having a melt volume flow rate MVR of 18 cm.sup.3/10 min (to ISO 1133 at a test temperature of 300° C. and 1.2 kg loading).

[0112] Component A-4: melt BPA polycarbonate (Makrolon® AL 2600) from Bayer MaterialScience having a melt volume flow rate MVR of 12 cm.sup.3/10 min (to ISO 1133 at a test temperature of 300° C. and 1.2 kg loading).

[0113] Component B: Poem DL-100 (diglycerol monolaurate) from Riken Vitamin as flow auxiliary.

[0114] Component C: triphenylphosphine (TPP) from BASF SE as heat stabilizer.

[0115] Component D-1: pentaerythritol tetrastearate (PETS) from Emery oleochemicals.

[0116] Component D-2: triisooctyl phosphate (TOF) from Lanxess AG as transesterification stabilizer.

[0117] The Charpy notched impact strength was measured to ISO 7391/180A at room temperature on single side gate injection moulded test bars measuring 80×10×3 mm.

[0118] As a measure for the heat distortion resistance the Vicat softening temperature VST/B50 was determined to ISO 306 on 80×10×4 mm test specimens with a needle load of 50 N and a heating rate of 50° C./h using a Coesfeld Eco 2920 instrument from Coesfeld Materialtest.

[0119] The melt volume flow rate (MVR) was determined to ISO 1133 (at a test temperature of 300° C., mass 1.2 kg) using a Zwick 4106 instrument from Zwick Roell.

[0120] The melt viscosities were determined to ISO 11443 (cone-plate arrangement).

[0121] The yellowness index (Y.I.) was determined to ASTM E 313 (observer: 10°/light type: D65) for specimens having a sheet thickness of 4 mm.

[0122] Transmission in the VIS range of the spectrum (400 nm to 800 nm) was determined to ISO 13468 for a sheet thickness of 4 mm.

[0123] Haze was determined to ASTM D1003 for a sheet thickness of 4 mm.

[0124] 2. Compositions

TABLE-US-00001 TABLE 1 Comparative examples 1V to 7V 1V 2V 3V 4V 5V 6V 7V A-1 wt % 93 93 93 93 93 93 93 A-2 wt % 7 6.9 6.8 6.6 6.9 6.8 6.6 D-1 wt % — 0.1 0.2 0.4 — — — B wt % — — — — 0.1 0.2 0.4 pellet eta rel 1.280 1.281 1.280 test specimen eta rel 1.278 1.277 1.276 MVR 7′/300° C./ ml/10 min 12.2 12.4 12.6 13.0 14.5 21.5 26.5 1.2 kg MVR 20′/300° C./ ml/10 min 12.2 12.3 12.4 13.1 15.9 22.0 28.8 1.2 kg Δ MVR 20′/MVR 7′ 0.0 −0.1 −0.2 0.1 1.4 0.5 2.3 Vicat VSTB 50 ° C. 146.6 146.1 144.8 143.6 145.3 144.7 143.5 coefficient of friction Rz 1.5 sliding friction 0.52 0.39 0.33 0.29 0.39 0.34 0.32 static friction 0.58 0.42 0.39 0.35 0.36 0.39 0.39 notched impact strength ISO 7391/180A (3 mm) at 23° C. kJ/m.sup.2 63 64 63 64 64 65 64 tough tough tough tough tough tough tough at 0° C. kJ/m.sup.2 58 57 58 58 — 58 57 tough tough tough tough tough tough optics 4 mm transmission % 87.61 88.76 88.92 89.05 89.07 89.11 89.12 haze % 1.09 0.62 0.61 0.53 0.56 0.52 0.55 Y.I. 2.47 2.17 2.21 2.13 2.11 2.14 2.21

[0125] Important properties of the compositions 5V, 6V and 7V are reported in table 1. These are contrasted with the comparative examples 1V to 4V. It is apparent from the table that the compositions of the comparative examples which contain no diglycerol ester-pure polycarbonate or polycarbonate comprising PETS—exhibit markedly poorer melt volume flow rates MVR.

[0126] Surprisingly, the compositions 5V to 7V exhibit not only a significant improvement in the melt volume flow rate but also an increase in transmission and a reduced yellowness index YI.

TABLE-US-00002 TABLE 2 Inventive compositions comprising triisooctyl phosphate Formulation: 8 9 10 A-1 wt % 93 93 93 A-2 wt % 6.79 6.59 6.39 B wt % 0.2 0.4 0.6 D-2 wt % 0.01 0.01 0.01 Pellet η.sub.rel 1.279 1.278 1.277 test specimen η.sub.rel 1.277 1.274 1.273 MVR 7′/300° C./ ml/10 min 20.8 29.5 52.6 1.2 kg MVR 20′/300° C./ ml/10 min 23.1 31.1 53.4 1.2 kg Δ MVR 20′/MRV7′ 2.3 1.6 0.8 Vicat VSTB 50 ° C. 143.9 141.9 140.3 notched impact strength ISO 7391/180A (3 mm) at RT kJ/m.sup.2 64 65 62 tough tough tough at 0° C. kJ/m.sup.2 57 58 61 tough tough tough optics 4 mm transmission % 89.3 89.35 89.36 haze % 0.44 0.39 0.38 Y.I. 2.11 2.04 2.06

[0127] Important properties of the inventive compositions 8 to 10 are reported in table 2. Compared to examples 6V and 7V it is apparent that the melt volume flow rates MVR are increased further for the triisooctyl phosphate-containing examples.

[0128] Surprisingly, the inventive compositions exhibit not only a significant improvement in the melt volume flow rate but also a decrease in haze.

TABLE-US-00003 TABLE 3 Comparative examples 11V to 14V 11V 12V 13V 14V A-3 wt % 100 99.9 99.8 99.7 B wt % 0.1 0.2 0.3 pallet eta rel 1.257 1.255 1.256 1.255 MVR 300° C./ cm.sup.3/10 min 18.1 23.5 29.7 38.5 1.2 kg melt viscosity at 280° C. eta 50 Pa .Math. s 402 eta 100 Pa .Math. s 485 400 281 182 eta 200 Pa .Math. s 472 395 277 175 eta 500 Pa .Math. s 415 354 253 170 eta 1000 Pa .Math. s 339 296 230 152 eta 1500 Pa .Math. s 285 252 212 136 eta 5000 Pa .Math. s 137 127 113 83 melt viscosity at 300° C. eta 50 Pa .Math. s — — — — eta 100 Pa .Math. s — — — — eta 200 Pa .Math. s 235 151 146 126 eta 500 Pa .Math. s 218 145 132 126 eta 1000 Pa .Math. s 195 137 126 118 eta 1500 Pa .Math. s 174 131 118 107 eta 5000 Pa .Math. s 95 82 76 72

TABLE-US-00004 TABLE 4 Inventive compositions and comparative example 15V Formulation 15V 16 17 A-4 wt % 100 99.8 99.6 B wt % 0.2 0.4 D-2)* ppm 100 100 100 pellet eta rel 1.272 1.270 1.269 melt viscosity at 280° C. eta 50 Pa .Math. s 631 535 440 eta 100 Pa .Math. s 608 525 423 eta 200 Pa .Math. s 570 497 401 eta 500 Pa .Math. s 475 425 331 eta 1000 Pa .Math. s 370 308 242 eta 1500 Pa .Math. s 305 251 185 eta 5000 Pa .Math. s 143 120 85 melt viscosity at 300° C. eta 50 Pa .Math. s 350 214 136 eta 100 Pa .Math. s 347 211 134 eta 200 Pa .Math. s 336 199 131 eta 500 Pa .Math. s 297 182 125 eta 1000 Pa .Math. s 250 161 115 eta 1500 Pa .Math. s 217 141 107 eta 5000 Pa .Math. s 115 85 70 melt viscosity at 320° C. eta 50 Pa .Math. s 198 111 77 eta 100 Pa .Math. s 195 110 76 eta 200 Pa .Math. s 189 108 74 eta 500 Pa .Math. s 177 106 71 eta 1000 Pa .Math. s 158 99 67 eta 1500 Pa .Math. s 142 92 63 eta 5000 Pa .Math. s 85 61 50 Vicat VSTB50 ° C. 143.8 143.3 142.2 *the indicated wt.-% auf A-4 and B relate to the total amount of A-4 and B. D-2) is additionally added.

[0129] Surprisingly, the compositions which have had diglycerol ester added to them in accordance with the invention exhibit a markedly improved melt viscosity determined at different shear rates.