Phosphonite compounds as process stabilizers

Abstract

The present invention relates to a composition comprising one or more (co)polymers and one or more phosphonite compounds that contain cardanol moieties. Moreover, the present invention also refers to the use of the phosphonite compounds as process stabilizers, in particular refers to the use of such compounds for stabilizing and/or reducing the Yellowness Index of a (co)polymer composition exposed to heat and/or mechanical stress.

Claims

1. A composition comprising: A) one or more (co)polymers as component A; B) one or more phosphonite compounds of formula (I) as component B ##STR00006## wherein, independently of one another each R1 is independently from another a linear C13-17-alkyl; R2 is selected from the group consisting of hydrogen, linear or branched C.sub.1-18-alkyl, linear or branched C.sub.1-12-alkoxy; and R3 is selected from the group consisting of hydrogen, linear or branched C.sub.1-18-alkyl, linear or branched C.sub.1-12-alkoxy; and C) optionally one or more (co)polymer additives as component C.

2. The composition of claim 1, wherein R2 and R3 are independently from each other selected from the group consisting of hydrogen, linear or branched C.sub.1-4-alkyl, linear or branched C.sub.1-4-alkoxy.

3. The composition of claim 1, wherein R2 and R3 are both hydrogen.

4. The composition of claim 1, wherein R2 and R3 are both hydrogen and each R1 is a linear C.sub.15-alkyl.

5. The composition of claim 1, wherein said composition comprises 300 to 2000 ppm of component B, based on the sum of components A, B and C in the composition.

6. The composition of claim 1, wherein said composition is a thermoplastic molding mass.

7. The composition of claim 1, wherein the (co)polymer component A is selected from the group consisting of polyolefins, styrene (co)polymers, polyurethanes, polyesters, polyamides, polyacetals and blends of two or more thereof.

8. The composition of claim 1, wherein said composition comprises or consists of: A) 89.8 to 99.97% by weight of one or more (co)polymers as component A; B) 0.03 to 0.2% by weight of one or more phosphonite compounds of formula (I) as component B; and C) 0 to 10% by weight of one or more (co)polymer additives as component C.

9. The composition of claim 1, wherein said composition comprises or consists of: A) 94.95 to 99.9% by weight of one or more (co)polymers as component A; B) 0.05 to 0.1% by weight of one or more phosphonite compounds of formula (I) as component B, wherein, independently of one another each R1 is independently from another a linear C.sub.15-alkyl; R2 and R3 are both equal and are selected from the group consisting of hydrogen and linear or branched C.sub.1-4-alkyl; and C) 0 to 5% by weight of one or more (co)polymer additives as component C.

10. The composition of claim 1, wherein said composition comprises 500 to 700 ppm of component B, based on the sum of components A, B and C in the composition.

11. The composition of claim 1, wherein said composition further comprises one or more (co)polymer additives as component C selected from the group consisting of antioxidants, acid scavengers UV stabilizers, UV absorbers, UV quenchers, antistatics, flame retardants, lubricants, plasticizers, nucleating agents, metal deactivators, biocides, impact modifiers, fillers, dyes, and pigments.

12. A method for stabilizing and/or reducing the Yellowness Index of a (co)polymer composition exposed to heat and/or mechanical stress during processing, wherein said method comprises the steps of: (i) providing one or more (co)polymers as component A and one or more phosphonite compounds of formula (I) as component B according to claim 1, and optionally one or more (co)polymer additives; and (ii) melt processing the one or more (co)polymers of component A in the presence of component B.

13. The method of claim 12, wherein 300 to 2000 ppm of component B, based on the sum of components A, B and C in the composition, are used.

14. The method of claim 12, wherein the (co)polymer composition comprises one or more polyolefins as component A.

Description

EXAMPLES

(1) Synthesis of the Compounds of Formula (I)

(2) Cardanol was hydrogenated and distilled off before use. Under nitrogen, purified cardanol (3.57 g, 11.73 mmol) was dissolved in 15 ml of anhydrous toluene. After stirring for 10 minutes, anhydrous pyridine (1.13 ml, 13.97 mmol) was added to the solution and the mixture was stirred for 15 minutes. Dichloro-phenyl-phosphine (1 g, 5.59 mmol) was then added dropwise to the reaction medium at low temperature (0° C.). A white precipitate appeared instantaneously during the addition that corresponds to the pyridinium salt. The reaction medium was then heated to 40° C. for an additional period of 4 hours. The completion of the reaction was controlled by gas chromatography and the reaction mixture was filtered under argon to remove the salts; the solution was then evaporated to give a colourless oil with a yield in pure substance at 85%.

(3) Application in Polypropylene During Processing

(4) It is useful to manually mix/distribute liquid ingredients with some part of the resin (powder) before further mix the whole batch in Kenwood mixer. Additives which are not available in powder form have to be crushed before further mixing with all other ingredients in the Kenwood mixer.

(5) Pre-extrusion was carried out by means of a Collin single screw extruder with water bath. A screw configuration with diameter 30, compression ratio 1:4 and L/D ratio 25 was chosen. The die had a diameter of 3 mm and was operating with a crew speed of 70 rpm. Cooling takes place in water. Pelletization takes place with high-speed mode (Pelletizer T1). Procedure: Single pass compounding, taking sample as pass 0.

(6) A (co)polymeric composition comprising: 99.78 parts of polypropylene 0.05 part of Hostanox O 10® 0.10 part of calcium stearate 0.07 part of inventive compound

(7) was mixed by dry mixing and pre-extrusion at 210° C. The composition was then repeatedly extruded at a temperature of 270° C. and pelletized in a water bath after cooling of the (co)polymer melt. The melt flow index (MFI; 230° C., 2.16 kg) (ASTM D-1238-70) and the Yellowness Index (YI) (ASTM D1925-70) using pellets were determined after the first, third and fifth pass.

(8) Melt Flow Rate (MFR):

(9) Instrument: CEAST MF50 Advanced Melt Flow tester, Multi-weight Instrument

(10) Setup (according to ISO 1133B); bore temperature: 230° C.

(11) Measure mode type: position

(12) Measure start position: 50.00 mm.

(13) Measure end position: 20.00 mm.

(14) Measurement Details:

(15) measure load: 2.16 kg; measure length: 13 mm. measure steps: 15. measure melt density: 0.740 g/cm.sup.3; die diameter: 2.095 mm.

(16) Compacting:

(17) compacting delay: 30; compacting force: 21.6 kg; compacting quote: 52 mm; weight apply delay: 240 s; sample weight: 4 g.

(18) Color:

(19) Measuring colorimetric values (L*, a*, b*, YI and dE); instrument: Spectrophotometer Minolta, model 3600d, mode: Reflectance SCE Hostanox O 10 (producer Clariant Corp.) is a highly established tetrafunctional sterically hindered phenol which mainly acts as long-term thermal stabilizer in various technical polymers. This phenol is produced and commercialized under numerous brandnames (e.g., Hostanox O 10 Songnox 1010, Inganox 1010, Anox 20):

(20) ##STR00004##

(21) Hostanox P-EPQ (producer Clariant Corp.) is a well-established bisfunctional organophosphonite which acts as stabilizer during processing of certain technical polymers, particularly of polyolefins:

(22) ##STR00005##

(23) Everfos 168 (also: PS 168) is phosphite stabilizer 168. This is a commercial stabilizer (Ciba Irgafos 168) that is, chemically, tris(2,4-ditert-butylphenyl)phosphite.

(24) TABLE-US-00001 TABLE 1 Effectiveness of compounds of formula (I) on processed polypropylene (PP) with regard to melt flow rate (MFR) and Yellowness Index (YI) in comparison to established stabilizers. Polypropylene (Nonstabilized Trilene HF 2.0 BM) MFR [g/10 min] YI Ex. Qty 1.sup.st 3.sup.rd 5.sup.th 1.sup.st 3.sup.rd 5.sup.th No. [ppm] pass pass pass pass pass pass CaSt/AO1010 1000/500 — — — — — — None 0 8.344 15.763 24.527 4.44 6.39 8.93 Everfos 168 1 1000 3.459 4.710 6.386 2.14 5.09 7.66 Hostanox P- 2 700 3.098 3.603 4.606 0.85 3.35 5.06 EPQ Compound (I) 3 700 4.210 6.060 7.725 13.41 22.24 29.28 Compound (II) 4 1000 4.140 7.264 10.260 7.46 14.07 17.41 Compound (III) 5 1500 3.711 5.347 7.697 3.15 6.74 11.54

(25) The following conclusions can be drawn from these results:

(26) Polypropylene degrades with reduction of chain length and therefore of viscosity, giving an increase in MFR values. The given cardanol phosphonites of formula (I) can act as antioxidant to protect the degradation of polypropylene. Compared with well-established commercial phosphites like Irgafos 168, organo-phosphonite like Hostanox P-EPQ®, the given cardanol phosphonites of formula (I) show somewhat lower performance on MFR retention and somewhat higher color value (YI), but are still effective stabilizers.

(27) Application in Linear Low Density Polyethylene (LLDPE)

(28) In a (co)polymeric composition comprising 99.83 parts of linear-low-density polyethylene (LLDPE) 0.05 part of Hostanox O 16® 0.05 part of Zinc stearate 0.07 part of inventive compound

(29) the components were mixed by dry mixing and pre-extrusion at 190° C. The composition was then repeatedly extruded at a temperature of 240° C. and pelletized in a water bath after cooling of the (co)polymer melt. The melt flow index (MFI) (ASTM D-1238-70, 190° C./2.16 kg) and the Yellowness Index (YI) (ASTM D1925-70) on pellets) were determined after the first, third and fifth pass.

(30) TABLE-US-00002 TABLE 2 Effectiveness of compounds of formula (I) on processed Linear Low Density Polyethylene (LLDPE) with regard to melt flow rate (MFR) and Yellowness Index (YI) in comparison to established stabilizers. Linear Low Density Polyethylene (Nonstabilized LLDPE DGM 1810) MFR [g/10 min] YI Ex. Qty 1.sup.st 3.sup.rd 5.sup.th 1.sup.st 3.sup.rd 5.sup.th No. [ppm] pass pass pass pass pass pass ZnSt/AO 1076 500/500 — — — — — — None 0 0.574 0.525 0.485 −1.43 −0.97 −0.20 Everfos 168 1 1200 0.866 0.816 0.752 −0.23 −0.01 0.60 Hostanox P- 2 700 0.889 0.828 0.680 −0.99 0.73 1.36 EPQ TNPP 3 1200 0.867 0.798 0.721 −0.29 0.54 1.01 Compound (I) 4 700 0.757 0.630 0.562 0.21 0.62 1.23 Compound (II) 5 1000 0.819 0.686 0.608 0.20 1.23 1.79 Compound (III) 6 1500 0.882 0.769 0.663 0.17 1.91 3.09

(31) The following conclusions may be drawn from these results: LLDPE usually degrades by means of crosslinking. Therefore with a rise in viscosity, lower MFI values are measured. The given cardanol phosphonites of formula (I) can act as antioxidant to protect the degradation of LLDPE. Compared with well-established commercial phosphites like Irgafos 168, organo-phosphonite like Hostanox P-EPQ®, the given cardanol phosphonites of formula (I) show lower performance on MFR retention Towards retention of color particularly the compounds of formula (I) exhibit comparable performance than other phosphite and organo-phosphonite.

(32) High Density Polyethylene (HDPE)

(33) Example HDPE-1

(34) A polymeric composition comprising

(35) TABLE-US-00003 99.78 parts of high-density polyethylene (HDPE) 0.05 part of Hostanox O 10 ® 0.10 part of calcium stearate 0.07 part of inventive compound

(36) were mixed by dry mixing and pre-extrusion at 190° C. The composition was then repeatedly extruded at a temperature of 270° C. and pelletized in a water bath after cooling of the (co)polymer melt. The melt flow index (MFI) (190° C./2.16 kg) (ASTM D-1238-70) and the Yellowness Index (YI) (ASTM D1925-70) on pellets were determined after the first, third and fifth pass.

(37) TABLE-US-00004 TABLE 3 Effectiveness of compounds of formula (I) on processed High Density Polyethylene (HDPE) with regard to melt flow rate (MFR) and Yellowness Index (YI) in comparison to established stabilizers. High Density Polyethylene (Nonstabilized InnoPlus HD2308J) MFR [g/10 min] YI Ex. Qty 1.sup.st 3.sup.rd 5.sup.th 1.sup.st 3.sup.rd 5.sup.th No. [ppm] pass pass pass pass pass pass CaSt/AO1010 1000/500 None 0 6.493 8.156 10.047 2.66 4.75 6.42 Irgafos 168 1 1000 6.352 6.744 7.332 3.62 6.26 7.51 Hostanox P- 2 700 6.301 6.501 7.378 −0.03 1.36 4.05 EPQ Compound (I) 3 700 6.341 7.256 8.685 3.21 4.99 6.07 Compound (II) 4 1000 6.324 6.859 8.117 1.96 4.71 6.25 Compound (III) 5 1300 6.320 6.763 7.709 −0.33 4.01 5.54

(38) The following conclusions may be drawn from these results of Examples HDPE-1 to HDPE-5: The given cardanol phosphonites of formula (I) can act as antioxidant to protect the degradation of HDPE. Compared with well-established commercial phosphites like Irgafos 168, the given cardanol phosphonites of formula (I) show slightly lower performance on MFR retention but better color value (YI) even at lower amount of phosphorus equivalent. Increase concentration of the cardanol phosphonites provides better improvement of color value (YI) and MFR retention of HDPE.