Impact modifier based on polyisobutane for polyamides

Abstract

A thermoplastic molding composition containing A) 20 to 99.9 wt % of a thermoplastic polyamide, B) 0.1 to 40 wt % of an alkenylsuccinic acid derivative obtained by reaction of polyiso-butene (B1) having a number-average molecular weight Mn of 10,000 to 50,000 at temperatures of 180 C. to 250 C. with maleic acid or derivatives thereof (B2) in a stoichiometric ratio of at least 2 equivalents of ,-unsaturated mono- and dicarboxylic acid or derivatives thereof (B2) per reactive double bond in the polyisobutene (B1) for a duration of at least 15 minutes to 10 hours and up to 10 bar of positive pressure, wherein the derivatives are anhydrides, mono- or dialkyl esters, and mixed esters, and wherein the reactive double bonds are the sum total of the terminal - and -double bonds in the polyisobutene (B1), and C) 0 to 60 wt % of further additives, wherein the weight percentages for the components A) to C) sum to 100%.

Claims

1. A thermoplastic molding composition comprising A) 20 to 99.9 wt % of a thermoplastic polyamide, B) 0.1 to 40 wt % of an alkenylsuccinic acid derivative obtained by reaction of a polyisobutene (B1) having a number-average molecular weight Mn of 10,000 to 50,000 at a temperature of 180 C. to 250 C. with maleic acid or derivatives thereof (B2) in a stoichiometric ratio of at least 2 equivalents of the maleic acid or derivatives thereof (B2) per reactive double bond in the polyisobutene (B1) for a duration of at least 15 minutes to 10 hours and up to 10 bar of positive pressure, wherein the derivatives are selected from the group consisting of anhydrides, mono- or dialkyl esters and mixed esters and wherein the reactive double bonds are the sum total of the terminal - and -double bonds in the polyisobutene (B1), and C) 0 to 60 wt % of further additives, wherein the weight percentages for the components A) to C) sum to 100%.

2. The thermoplastic molding composition according to claim 1, wherein the molding composition is constructed from A) 30 to 99.5 wt %, B) 0.5 to 25 wt %, and C) 0 to 50 wt %.

3. The thermoplastic molding composition according to claim 1 in which the component B) has a bismaleation level of 1% to 20% determined via the saponification number according to DIN 53401: 1988-06.

4. The thermoplastic molding composition according to claim 1, in which the polyisobutene (B1) is an isobutene homopolymer.

5. The thermoplastic molding composition according to claim 1, in which the polyisobutene (B1) is a copolymer obtainable by polymerization of isobutene-containing C4-hydrocarbon streams.

6. The thermoplastic molding composition according to claim 1, in which the proportion of terminal - and -double bonds in the polyisobutene (B1) is 30 to 100 mol %.

7. The thermoplastic molding composition according to claim 1 in which the component (B2) is maleic anhydride or di-C1-C4-alkyl maleate.

8. The thermoplastic molding composition according to claim 1 in which the component (B2) is maleic anhydride.

9. The thermoplastic molding composition according to claim 1, wherein the molar ratio of component (B2) to reactive double bond in the polyisobutene (B1) is from 3:1 to 30:1 in the reaction.

10. The thermoplastic molding composition according to claim 1 for use in producing molded articles of any type.

11. A molded article obtained from the thermoplastic molding composition according to claim 1.

Description

EXAMPLES

(1) The following components were used:

(2) Component A1:

(3) Polyamide 6 having an intrinsic viscosity IV of 150 ml/g, measured as a 0.5 wt % solution in 96 wt % sulfuric acid at 25 C. according to ISO 307 (Ultramid B27 from BASF SE was employed.)

(4) Component A2:

(5) Polyamide 66 having an intrinsic viscosity IV of 125 ml/g, measured as a 0.5 wt % solution in 96 wt % sulfuric acid at 25 C. according to ISO 307 (Ultramid A24 from BASF SE was employed.)

(6) Component B1V:

(7) High molecular weight polyisobutene Oppanol B10 from BASF SE, Ludwigshafen having a molar weight Mn of about 17 000 and a double bond content of 40% - and 47% -double bonds.

(8) Production of Component B2

(9) High molecular weight polyisobutene Oppanol B10 from BASF SE, Ludwigshafen having a molar weight Mn of about 17 000 and a double bond content of 40% - and 47% -double bonds and maleic anhydride (molar ratio maleic anhydride:polyisobutene=5:1 (based on the sum of - and -double bonds)) were initially charged in a pressure vessel. The reaction mixture was stirred under nitrogen for 7 hours at 240 C. The vessel was then cooled to 200 C. and xylene was added slowly. The solution having a solids content of about 70% was discharged from the vessel at 120 C., diluted to 50% strength with heptane, filtered off and distilled off under vacuum at 205 C.

(10) TABLE-US-00002 Saponification Proportion Maleic Yield number of maleated anhydride:polyisobutene (%) (mg KOH/g) components 5:1 47 6 47%

(11) Production of Component B3

(12) The abovementioned procedure was also used for the polyisobutene Oppanol B12 from BASF SE, Ludwigshafen having a molar weight Mn of about 22 000 and a double bond content of 40% - and 40% -double bonds. The maleic anhydride: polyisobutene ratio was 5:1. The solids content in the xylene solution was 60%, the yield was 40%. The proportion of maleated components was 40%.

(13) Production of Component B4

(14) The polyisobutene Oppanol B15 from BASF SE, Ludwigshafen having a molar weight Mn of about 37 000 and a content of - and -double bonds (in total) of 75% was filled into a kneader and blanketed with nitrogen. Maleic anhydride was added (maleic anhydride: polyisobutene ratio=15:1) and the mixture was initially kneaded at room temperature for 5 min. The kneader was heated to 240 C. and the mixture was kneaded at 240 C. for 60 min. A vacuum was then slowly applied under a slight nitrogen stream and increased in stepwise fashion; the mixture was held under vacuum for 15 min. The kneader was then cooled to 190 C. and the product discharged. The yield was 35%.

(15) Under these conditions the residual content of maleic anhydride was able to be reduced to less than 0.005 g/100 g of product.

(16) TABLE-US-00003 Temperature Residence time Maleic Conversion ( C.) (min) anhydride:polyisobutene [%] 240 60 15:1 32

(17) The proportion of maleated components was determined as 25% to 30%.

(18) Component B5V: 50:50 mixture of Oppanol B10 and GlissopalSAF from BASF SE (a low molecular weight polyisobutene having a molecular weight (Mn) of 1000 g/mol which was modified with maleic anhydride.

(19) Distribution number: 85-95 mg KOH/g

(20) MA content: no more than 0.17 wt %

(21) Component B6V:

(22) Fusabond MN 493 D from DuPont

(23) Ethylene-1-Octene-MA copolymer (60:39.5:0.5).

(24) Component C1:

(25) Ca stearate

(26) Component C2:

(27) Irganox 1098 from BASF SE CAS 23128-74-7

(28) ##STR00008##

(29) Component C3:

(30) Irgafos 168 from BASF SE CAS 31570-04-4

(31) ##STR00009##

(32) Component C4:

(33) 2090 batch of KI/Cul (4:1) in component A1

(34) Component C5:

(35) Glass fibers (chopped glass)

(36) Production of Molding Compositions

(37) Compounding performed in a ZSK 18 apparatus, throughput 6 kg/h

(38) Melt temperature: 280-300 C.

(39) Injection Molding Conditions

(40) Melt temperature: 260-290 C.

(41) Mold temperature: 60-80 C.

(42) Measurements:

(43) Charpy notched impact strength: ISO179-2/1eA(F)

(44) Charpy unnotched impact strength: ISO179-1/1eU

(45) Tensile test: ISO 527-2

(46) MVR: ISO 1133-1 PA6/PA66 at 275 C./5 kg

(47) Heat Ageing Resistance:

(48) Charpy rods were stored in a circulating air oven at 150 C. for various durations: 96 h; 240 h; 504 h; 984 h. The mechanics were then determined according to the standard: ISO179-2/1eA(F).

(49) Molecular Weight Determination of Component B:

(50) Gel permeation chromatograpy using THF as the solvent and polystyrene as the standard. The columns employed were two 30 cm PLgel Mixed-B columns manufactured with a pore size of 10 m and an internal diameter of 7.5 mm. The separating range of the columns is 500-10 000 000 g/mol.

(51) % of Functionalized Chains:

(52) To determine the percentage of functionalized chains the polymer was dissolved in n-heptane and applied to a column comprising silica gel 60. The non-functionalized chains were separated from the functionalized chains by column chromatography since the functionalized chains were not eluted. The proportion of non-functionalized chains was weighed to determine the percentage of functionalized chains. This method was assisted by 1H-NMR measurements based on the signals for the different double bonds (product vs. starting material).

(53) Clarity+Haze:

(54) Determination of total transmission, haze according to ASTM D 1003 and clarity. The instrument used was a BYK Gardner haze gard plus.

(55) Contact Angle:

(56) The polyamide samples were dried at 80 C. and welded into aluminum sacks. Measurement of the contact angle was carried out directly after opening of the sacks to prevent effects caused by absorbed moisture. A drop of deionized water (milli-Q) is applied to the surface and the static contact angle is determined at 23 C. using a DSA100 instrument from Krss GmbH.

(57) TABLE-US-00004 Instrument DSA100, Krss Conditions of 23 C., static contact angle measurement Measurement liquids Deionized water (Milli-Q) Sample preparation The PA samples were measured immediately after opening from the welded packaging.

(58) TABLE-US-00005 TABLE 1 PA6 compounds and mechanics measurements Exp A1 A2 B1V B2 B3 B4 B5V B6V C1 C2 C3 No. (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) 1V 100 2V 99 0.5 0.5 3V 90 10 4 10 5 5 90 10 6 89.1 9.9 0.5 0.5 7 80 20 8 89 9.9 0.5 0.5 9 89 9.9 0.5 0.5 10V 90 10 11V 69 0.5 0.5 12 59.1 9.9 0.5 0.5 13 59.1 9.9 0.5 0.5 14 59 10 0.5 0.5 Notched Charpy, Notched Charpy, Exp C4 C5 notch A, 23 C./ notch Unnotched No. (%) (%) 50% rel. hum. A 30 C. Charpy 50 C. MVR 1V 6.8 7.3 151 2V 6.5 8.6 34 3V 8.7 5.3 All break 234 120 60 4 13.0 10.1 125 5 15.2 12.1 Only 1 out 108 of 5 breaks 6 15.6 11.5 41 7 17.0 13.3 82 8 17.8 12.2 40 9 18.8 11.9 56 10V 12.3 8.9 11V 30 11.6 8.4 12 12 30 17.1 9.3 15 13 30 17.9 10.6 12 14 30 17.8 10.0 22

(59) TABLE-US-00006 TABLE 2 PA66 compounds and mechanics values Notched charpy, notch A, Notched Charpy, Exp A1 A2 B1V B2 B3 B4 B5 B6V C1 C2 C3 C4 C5 23 C./50% Notch No. (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) rel. hum. A, 30 C. MVR 1V 99 0.3 0.7 5.16 5.2 192 2 91 8 0.3 0.7 11.1 8.22 147 3 8 0.3 0.7 12.5 8 182 4V 8 0.3 0.7 7.7 6.23 124 5 61 8 0.3 0.7 30 13.7 8.14 38 6 61 8 0.3 0.7 30 12.2 7.7 45 7V 61 8 0.3 0.7 30 14.7 9.32 31

(60) TABLE-US-00007 TABLE 3 Heat ageing resistance at 150 C. Storage time Notched Charpy, at 150 C. notch A, 23 C./ Unnotched Charpy Exp No. [h] 50% rel. hum. Notch A, 30 C. 2 0 11.1 1 out of 5 breaks 96 11.0 1 out of 5 breaks 240 8.6 0 out of 5 break 504 6.7 1 out of 5 breaks 984 3.5 All break 4V 0 7.7 All break 96 5.1 All break 240 4.1 All break 504 2.7 All break 984 1.2 All break

(61) Optical Properties

(62) The pelletized polyamide material was melted in a conical twin-screw extruder (DSM Xplore, 15 cc) under the following conditions:

(63) Residence time: 2 min

(64) Barrel temperature: 260 C.

(65) Speed of rotation: 80 rpm

(66) The injection molding of the molten polymers was performed in a 10 cc DSM micro-injection molding apparatus. To this end the molten compound was filled directly into the cylinder of the injection molding machine under nitrogen. The melt was subsequently injected into a polished rectangular mold of dimensions (30 mm30 mm1.27 mm). The following parameters were used:

(67) Mold: plaque, polished; 30 mm30 mm1.27 mm

(68) Mold temperature: 60 C.

(69) Cylinder temperature: 260 C.

(70) Injection pressure: 8-9 bar

(71) TABLE-US-00008 TABLE 4 Exp. No. Description Transmission % Haze % Clarity % 1V 100% A1 67 101 74 6 A1/B2 51 101 62 8 A1/B3 55 100 67 15V A1/B6V (90:10) 37 102 12

(72) Contact Angle/Polarity

(73) It is apparent that the PIBSAI increases the contact angle to water, thus demonstrating hydrophobization. This is not observed for Fusabond MN-493 D.

(74) TABLE-US-00009 TABLE 5 Exp No. KW H2O [] 1V 75.3 2.5 5 95.4 2.6 15V 73.6 3.9