ABS THERMOPLASTIC MOLDING COMPOSITION FOR BLOW MOLDING

Abstract

ABS thermoplastic molding compositions for the preparation of blow molded articles in the automotive and household sector comprising (A) 30 to 40 wt.-% ABS graft rubber copolymer, (B) 25 to 35 wt.-% alpha-methylstyrene/acrylonitrile copolymer, (C) 30 to 40 wt.-% styrene/acrylonitrile copolymer, (D) 0.05 to 0.50 wt.-% homo- or copolymer comprising monomer structure units with a C.sub.3-C.sub.6-alkyleneoxide side chain having an epoxy terminal group or with a modified, functionalized C.sub.3-C.sub.6-alkyleneoxide side chain, and (E) 0 to 5 wt.-% further additives. Component (D) is preferably polyglycidylmethacrylate.

Claims

1.-15. (canceled)

16. A thermoplastic molding composition comprising components A, B, C, D, and E: (A) 30 to 40 wt.-% of at least one graft copolymer (A) consisting of 15 to 60 wt.-% of a graft sheath (A2) and 40 to 85 wt.-% of a graft substrate (A1), where (A1) and (A2) sum up to 100 wt.-%, wherein the graft substrate (A1) is at least one agglomerated butadiene rubber latex, obtained by emulsion polymerization of styrene and acrylonitrile in a weight ratio of 95:5 to 50:50 to obtain a graft sheath (A2), wherein the styrene and/or acrylonitrile is optionally partially replaced by alphamethylstyrene, methyl methacrylate, maleic anhydride, or mixtures thereof, in the presence of the at least one agglomerated butadiene rubber latex (A1) with a median weight particle diameter D50 of 200 to 800 nm; where the agglomerated rubber latex (A1) is obtained by agglomeration of at least one starting butadiene rubber latex (S-A1) having a median weight particle diameter D50 of equal to or less than 120 nm, with at least one acid anhydride; (B) 25 to 35 wt.-% of at least one copolymer (B) of alpha-methylstyrene and acrylonitrile in a weight ratio of from 95:5 to 50:50, wherein the alpha-methylstyrene and/or acrylonitrile is optionally partially replaced by methyl methacrylate, maleic anhydride, and/or 4-phenylstyrene; (C) 30 to 40 wt.-% of at least one copolymer (C) of styrene and acrylonitrile in a weight ratio of from 95:5 to 50:50, wherein the styrene and/or acrylonitrile is optionally partially replaced by methyl methacrylate, maleic anhydride, and/or 4-phenylstyrene; wherein copolymer C has a weight average molar mass N.sub.w of 150,000 to 300,000 g/mol; (D) 0.05 to 0.50 wt.-% of at least one homo- or copolymer (D) comprising structure units derived from at least one monomer with at least one C.sub.3-C.sub.6-alkyleneoxide side chain which epoxy group is the terminal group, or structure units derived from at least one monomer with at least one modified C.sub.3-C.sub.6-alkyleneoxide side chain having an ester, ether, carbonate, carbamate, hydroxyl, or acrylate terminal group which group has been formed by reaction with the terminal epoxy group of the C.sub.3-C.sub.6-alkyleneoxide; (E) 0 to 5 wt.-% of further additives and/or processing aids (E); where the components A, B, C, D, and, if present E, sum to 100 wt.-%.

17. The thermoplastic molding composition according to claim 16, comprising: 30 to 40 wt.-% component (A), 25 to 35 wt.-% component (B), 30 to 40 wt.-% component (C), 0.05 to 0.40 wt.-% component (D), and 0.01 to 5 wt.-% component (E).

18. The thermoplastic molding composition according to claim 16, wherein component (D) is a homo- or copolymer comprising structure units derived from at least one monomer with C3-C4-alkyleneoxide side chains having epoxy end groups.

19. The thermoplastic molding composition according to claim 16, wherein component (D) is selected from the group consisting of: polyglycidylmethacrylates, polyglycidylacrylates, polyglycidylethers, polyglycidylazides, polyglycidylamines and poly (C2-C6)-alkylene-co-glycidyl (meth)acrylates.

20. The thermoplastic molding composition according to claim 16, wherein component (D) is polyglycidylmethacrylate and/or polyethylene-co-glycidyl methacrylate.

21. The thermoplastic molding composition according to claim 16, wherein: the graft sheath (A2) is obtained by emulsion polymerization of styrene and acrylonitrile solely; the copolymer (B) is a copolymer of alpha-methylstyrene and acrylonitrile solely; and the copolymer (C) is a copolymer of styrene and acrylonitrile solely.

22. The thermoplastic molding composition according to claim 16, wherein the agglomerated butadiene rubber latex (A1) has a median weight particle diameter D50 of 280 to 350 nm.

23. The thermoplastic molding composition according to claim 16, wherein the copolymer (B) is a copolymer of alpha-methylstyrene and acrylonitrile in a weight ratio of from 75:25 to 55:45.

24. The thermoplastic molding composition according to claim 16, wherein the copolymer (C) is a copolymer of styrene and acrylonitrile in a weight ratio of from 75:25 to 65:35.

25. The thermoplastic molding composition according to claim 16, wherein the copolymer C has a weight average molar mass M.sub.w of 170,000 to 230,000 g/mol.

26. A process for the preparation of the thermoplastic molding composition according to claim 16 by melt mixing the components (A), (B), (C), (D) and, if present (E), and optionally further polymers (TP) at temperatures in the range of from 160° C. to 400° C.

27. A method of using thermoplastic molding compositions according to claim 16 for the production of a molded article.

28. A molded article made from the thermoplastic molding composition according to claim 16.

29. A method of using molded articles according to claim 28 for applications in the automotive and household sector.

30. A method of using molded articles according to claim 28 as a front bumper protector or spoiler.

Description

EXAMPLES

[0116] Test Methods

[0117] Particle Size Dw/D50

[0118] For measuring the weight average particle size Dw (in particular the median weight particle diameter D50) with the disc centrifuge DC 24000 by CPS Instruments Inc. equipped with a low density disc, an aqueous sugar solution of 17.1 mL with a density gradient of 8 to 20% by wt. of saccharose in the centrifuge disc was used, in order to achieve a stable flotation behavior of the particles. A polybutadiene latex with a narrow distribution and a mean particle size of 405 nm was used for calibration. The measurements were carried out at a rotational speed of the disc of 24,000 r.p.m. by injecting 0.1 mL of a diluted rubber dispersion into an aqueous 24% by wt. saccharose solution. The calculation of the weight average particle size Dw was performed by means of the formula

D.sub.w=sum(n.sub.i*d.sub.i.sup.4)/sum(n.sub.i*d.sub.i.sup.3)

[0119] n.sub.i: number of particles of diameter d.sub.i.

[0120] Molar Mass M.sub.w

[0121] The weight average molar mass M.sub.w is determined by GPC (solvent: tetrahydrofuran, polystyrene as polymer standard) with UV detection according to DIN 55672-1:2016-03.

[0122] Tensile Test

[0123] Tensile test on ABS blends was carried out at 23° C. using a Universal testing Machine (UTM) of Lloyd Instruments, UK.

[0124] Flexural Test

[0125] Flexural test was carried out on ABS blends (ASTMD 790 standard) using a UTM of Lloyd Instruments, UK.

[0126] Impact Test

[0127] Izod impact tests were performed on notched specimens (ASTM D 256 standard) using an instrument of CEAST (part of Instron's product line), Italy.

[0128] Heat Deflection Temperature (HDT)

[0129] Heat deflection temperature test was performed on injection molded specimen (ASTMD 648 standard) using a CEAST, Italy instrument.

[0130] VICAT Softening Temperature (VST)

[0131] Vicat softening temperature test was performed on injection molded test specimen (ASTM D 1525-09 standard) using a CEAST, Italy machine. Test is carried out at a heating rate of 120° C./hr (Method B) at 50 N loads.

[0132] Rockwell Hardness

[0133] Hardness of the injection molded test specimen (ISO—2039/2-11) was tested using a Rockwell hardness tester.

[0134] Melt Flow Index (MFI) or Melt Volume Flow Rate (MFR)

[0135] MFI/MFR test was performed on pellets (ISO 1133 standard) using a MFI-machine of CEAST, Italy.

[0136] Materials used:

Component (A)

Fine-Particle Butadiene Rubber Latex (S-A1)

[0137] The fine-particle butadiene rubber latex (S-A1) which is used for the agglomeration step was produced by emulsion polymerization using tert-dodecylmercaptan as chain transfer agent and potassium persulfate as initiator at temperatures from 60° to 80° C. The addition of potassium persulfate marked the beginning of the polymerization. Finally the fine-particle butadiene rubber latex (S-A1) was cooled below 50° C. and the non reacted monomers were removed partially under vacuum (200 to 500 mbar) at temperatures below 50° C. which defines the end of the polymerization. Then the latex solids (in % per weight) were determined by evaporation of a sample at 180° C. for 25 min. in a drying cabinet. The monomer conversion is calculated from the measured latex solids. The butadiene rubber latex (S-A1) is characterized by the following parameters, see table 1.

[0138] Latex S-A1-1

[0139] No seed latex is used. As emulsifier the potassium salt of a disproportionated rosin (amount of potassium dehydroabietate: 52 wt.-%, potassium abietate: 0 wt.-%) and as salt tetrasodium pyrophosphate is used.

TABLE-US-00001 TABLE 1 Composition of the butadiene rubber latex S-A1 Latex S-A1-1 Monomer butadiene/styrene 90/10 Seed Latex (wt.-% based on monomers) ./. Emulsifier (wt.-% based on monomers) 2.80 Potassium Persulfate (wt.-% based on monomers) 0.10 Decomposed Potassium Persulfate 0.068 (parts per 100 parts latex solids) Salt (wt.-% based on monomers) 0.559 Salt amount relative to the weight of solids 0.598 of the rubber latex Monomer conversion (%) 89.3 Dw (nm) 87 pH 10.6 Latex solids content (wt.-%) 42.6 K 0.91

K=W*(1-1.4*S)*Dw

[0140] W=decomposed potassium persulfate [parts per 100 parts rubber]

[0141] S=salt amount in percent relative to the weight of solids of the rubber latex

[0142] Dw=weight average particle size (=median particle diameter D.sub.50) of the fine-particle butadiene rubber latex (S-A1)

[0143] Production of the coarse-particle, agglomerated butadiene rubber latices (A1)

[0144] The production of the coarse-particle, agglomerated butadiene rubber latices (A1) was performed with the specified amounts mentioned in table 2. The fine-particle butadiene rubber latex (S-A1) was provided first at 25° C. and was adjusted if necessary with deionized water to a certain concentration and stirred. To this dispersion an amount of acetic anhydride based on 100 parts of the solids from the fine-particle butadiene rubber latex (S-A1) as fresh produced aqueous mixture with a concentration of 4.58 wt.-% was added and the total mixture was stirred for 60 seconds. After this the agglomeration was carried out for 30 minutes without stirring. Subsequently KOH was added as a 3 to 5 wt.-% aqueous solution to the agglomerated latex and mixed by stirring. After filtration through a 50 μm filter the amount of coagulate as solid mass based on 100 parts solids of the fine-particle butadiene rubber latex (B) was determined. The solid content of the agglomerated butadiene rubber latex (A), the pH value and the median weight particle diameter D.sub.50 was determined.

TABLE-US-00002 TABLE 2 Production of the coarse-particle, agglomerated butadiene rubber latices (A1) latex A1 A1-1 A1-2 used latex S-A1 S-Al-1 S-Al-1 concentration latex S-A1 before agglomeration wt.-% 37.4 37.4 amount acetic anhydride parts 0.90 0.91 amount KOH parts 0.81 0.82 concentration KOH solution wt.-% 3 3 solid content latex A1 wt.-% 32.5 32.5 coagulate parts 0.01 0.00 pH 9.0 9.0 D.sub.50 nm 315 328

Production of the Graft Copolymers (A)

[0145] 59.5 wt.-parts of mixtures of the coarse-particle, agglomerated butadiene rubber latices A1-1 and A1-2 (ratio 50:50, calculated as solids of the rubber latices (A1)) were diluted with water to a solid content of 27.5 wt.-% and heated to 55° C. 40.5 wt.-parts of a mixture consisting of 72 wt.-parts styrene, 28 wt.-parts acrylonitrile and 0.4 wt.-parts tert-dodecylmercaptan were added in 3 hours 30 minutes. At the same time when the monomer feed started the polymerization was started by feeding 0.15 wt.-parts cumene hydroperoxide together with 0.57 wt.-parts of a potassium salt of disproportionated rosin (amount of potassium dehydroabietate: 52 wt.-%, potassium abietate: 0 wt.-%) as aqueous solution and separately an aqueous solution of 0.22 wt.-parts of glucose, 0.36 wt.-% of tetrasodium pyrophosphate and 0.005 wt.-% of iron-(II)-sulfate within 3 hours 30 minutes. The temperature was increased from 55 to 75° C. within 3 hours 30 minutes after start feeding the monomers. The polymerization was carried out for further 2 hours at 75° C. and then the graft rubber latex (=graft copolymer A) was cooled to ambient temperature. The graft rubber latex was stabilized with ca. 0.6 wt.-parts of a phenolic antioxidant and precipitated with sulfuric acid, washed with water and the wet graft powder was dried at 70° C. (residual humidity less than 0.5 wt.-%).

[0146] The obtained product is graft copolymer (A-I).

Component (B)

[0147] Statistical copolymer (B-I) from alphamethylstyrene and acrylonitrile with a ratio of polymerized styrene to acrylonitrile of 65:35 with a weight average molecular weight Mw of about 200,000 g/mol, a polydispersity of Mw/Mn of 2.5 and a melt volume flow rate (MVR) at 220° C./10 kg of 6 to 7 mL/10 minutes, produced by free radical solution polymerization.

Component (C)

[0148] Statistical copolymer (C-I) from styrene and acrylonitrile with a ratio of polymerized styrene to acrylonitrile of 72:28 with a weight average molecular weight Mw of 185,000 g/mol, a polydispersity of Mw/Mn of 2.5 and a melt volume flow rate (MVR) at 220° C./10 kg of 6 to 7 mL/10 minutes, produced by free radical solution polymerization.

Component (D)

[0149] D-I: Metablen® P-1901 (polyglycidyl methacrylate) obtained from Mitsubishi Chemical Corporation, Japan.

Component (E)

[0150]

TABLE-US-00003 EBS Ethylene bis stearamide SPEP Distearyl pentaeritritol diphosphite MS Magnesium stearate MgO Magnesium oxide PV Fast Yellow Red-shade yellow pigment from Clariant AG HGR/Pigment Yellow 191 CBP 1201 Carbon black powder from Phillips Carbon Black Limited

Thermoplastic Compositions

[0151] Graft rubber polymer (A-I), AMSAN-copolymer (B-I), SAN-copolymer (C-I), component (D-I), and the afore-mentioned components (E) were mixed (ratio see Table 3a, batch size 5 kg) for 4 to 5 minutes in a high speed mixer to obtain a uniform premix and then said premix was melt blended in a twin-screw extruder at a speed of 80 rpm and using an incremental temperature profile from 220° C. to 250° C. for the different barrel zones. The extruded strands were cooled in a water bath, air-dried and pelletized. Standard test specimens (ISO test bars) of the obtained blend were injection moulded at a temperature of 230-260° C. The test results are presented in table 4.

[0152] This is followed by Injection moulding of this blend to mould the standard test specimens. The temperature profile of injection moulding machine barrel is 230-260° C. incremental. Injection moulding is done and test specimens are prepared for mechanical testing. ISO test bars were injection moulded. The test results are shown in Table 3b.

[0153] The blow molding compositions of the comparative examples (=Cp. Ex.) 1 to 4 (see ingredients see Table 3a) were prepared and tested in the same manner as described for Example 1 (=Ex. 1) hereinbefore.

TABLE-US-00004 TABLE 3 Tested Blow molding Compositions Ingredients (wt.-%) Cp. Ex.1 Cp. Ex.2 Cp. Ex.3 Cp. Ex.4 Ex. 1 Component (A-I) 29.5 29.5 34.4 31.5 34.4 Component (B-I) 29.5 54.1 64.0 64.0 29.5 Component (C-I) 39.4 14.8 0.0 0.0 34.4 Metablen ® P531A 0.00 0.00 0.00 2.95 0.00 Component (D-I) 0.00 0.00 0.00 0.00 0.20 Total 98.4 98.4 98.4 98.4 98.6 Additives EBS 0.98 0.98 0.98 0.98 0.98 SPEP 0.15 0.15 0.15 0.15 0.15 MS 0.30 0.30 0.30 0.30 0.30 MgO 0.10 0.10 0.10 0.10 0.10 Yellow HGR 0.01 0.01 0.00 0.00 0.00 CBP 1201 0.05 0.05 0.00 0.00 0.00 Metablen ® P531A: high molecular weight acrylic processing aid (blend of polymethylmethacrylate and butylacrylate) obtainable from Mitsubishi Chemical Corporation, Japan.

TABLE-US-00005 TABLE 3b Properties of the Tested Blow Molding Compositions Cp. Ex. 5 Cp. Cp. Cp. Cp. Properties BM662 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 MFI, gm/10 2.5 5.0 4.5 4.0 2.8 2.5 min, 220° C., 10 kg load Notched Izod 14 33.0 29.0 31.0 30.5 41 Impact Strength, ¼″, kg .Math. cm/cm, at 23° C., ASTM D 256 Notched Izod 19 36.0 33.0 36.0 35.0 51 Impact Strength, ⅛″, kg .Math. cm/cm, at 23° C., ASTM D 256 Tensile Yield 490 525 520 460 505 485 Stress, kg/cm.sup.2, 50 mm/min, ASTM D 638 Elongation 17 16 17 26 25 21 at Break, %, 50 mm/min, ASTM D 638 Flexural 825 900 910 740 843 800 Strength, kg/cm.sup.2, 5 mm/min, ASTM D 790 Flexural 25250 28600 28800 24100 25357 25650 Modulus, kg/cm.sup.2, 5 mm/min, ASTM D 790 Rockwell 105 108 108 103 105 104 Hardness, R - Scale, ISO 2039/2 HDT, ¼″, 108 101 104 106 106 100 ° C., 1.8 MPa, ASTM D 648, Annealed 80° C., 4 hrs VST, Rate B, 117 107 111 115 111 104 50N, 120° C./hr, ° C., ASTM D 1525 BM 662: NPMI based ABS blow molding grade of LG Chemical Limited, Korea

[0154] Table 3b shows that the molding composition according to the invention (Example 1) has exceptional increased impact strength and further improved melt strength (decrease of MFI more than 40%) compared to BM 662

[0155] The inventive composition according to Example 1 has been used for blow-molding of a large component (weight 5.5 kg) called front nudge guard-abs/front bumper protector. All required critical tests have been passed successfully as proven by the obtained HDT-, Impact strength- and MFI-values.

[0156] The composition described is high heat resistant and suitable for fast baking processes, like drying and curing of painted components at elevated temperature, in particular in automotive painting processes.