ABS MOLDING COMPOSITION FOR SHEET EXTRUSION AND THERMOFORMING WITH HIGH ESCR, HIGH COLOR AND THERMAL STABILITY AND LOW TENDENCY TO DELAMINATION

Abstract

A thermoplastic molding composition comprising (A) 15 to 45 wt.-% graft copolymer (A) obtained by emulsion polymerization of styrene and acrylonitrile in presence of an agglomerated butadiene rubber latex (A1) with D50 of 150 to 800 nm; (B) 40 to 75 wt.-% copolymer (B) of styrene and acrylonitrile having a weight ratio of 80:20 to 65:35 and Mw of 150,000 to 300,000 g/mol, (C) 2.0 to 5.0 wt.-% elastomeric block copolymer (C) made from 15 to 65 wt.-% diene, and 35 to 85% by weight vinylaromatic monomer; (D) 2.0 to 5.0 wt.-% titanium dioxide pigment D comprising at least 95 wt.-% titanium dioxide and 1.7 to 3.3 wt.-% alumina; and (E) 0 to 7.0 wt.-% of at least one additive/processing aid (E) different from (D); having a high chemical resistance, high color and thermal stability and low tendency to delamination. This can be used for sheet extrusion and thermoforming, in particular as inner liner for a cooling apparatus.

Claims

1-18. (canceled)

19. A thermoplastic molding composition comprising components A, B, C, D, and optionally E: (A) 15 to 45 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), wherein (A1) is an agglomerated butadiene rubber latex and wherein (A1) and (A2) sum up to 100 wt.-%, obtained by emulsion polymerization of styrene and acrylonitrile in a weight ratio of 95:5 to 65:35 to obtain the graft sheath (A2), wherein the styrene and/or acrylonitrile is optionally replaced partially by alphamethylstyrene, methyl methacrylate, maleic anhydride, or mixtures thereof, in the presence of at least one agglomerated butadiene rubber latex (A1) with a median weight particle diameter D.sub.50 of 150 to 800 nm; wherein the agglomerated butadiene rubber latex (A1) is obtained by agglomeration of at least one starting butadiene rubber latex (S-A1) having a median weight particle diameter D.sub.50 of equal to or less than 120 nm, with at least one acid anhydride; (B) 40 to 75 wt.-% of at least one copolymer (B) of styrene and acrylonitrile in a weight ratio of from 80:20 to 65:35, wherein the styrene and/or acrylonitrile is optionally replaced partially by methyl methacrylate, maleic anhydride, and/or 4-phenylstyrene; wherein copolymer (B) has a weight average molar mass M.sub.w of 150,000 to 300,000 g/mol; (C) 2.0 to 5.0 wt.-% of at least one elastomeric block copolymer (C) made from 15 to 65 wt.-%, based on (C), of at least one diene, and 35 to 85 wt.-%, based on (C), of at least one vinylaromatic monomer, wherein block copolymer C comprises at least two blocks S which have polymerized units of vinylaromatic monomer, a glass transition temperature T.sub.g above 25° C., and form a hard phase, and at least one elastomeric block B/S (soft phase) which contains both polymerized units of vinylaromatic monomer and diene, has a random structure, a glass transition temperature Tg of from −50 to +25° C., and forms a soft phase, and the amount of the hard phase formed from the blocks S accounting for from 5 to 40% by volume, based on the total block copolymer; (D) 2.0 to 5.0 wt.-% of a titanium dioxide pigment D comprising at least 95 wt.-% titanium dioxide and 1.7 to 3.3 wt.-% alumina; and (E) 0 to 7.0 wt.-% of at least one additive and/or processing aid (E) which is different from (D); wherein the sum of components (A), (B), (C), (D), and, if present, (E) totals 100 wt.-%.

20. The thermoplastic molding composition according to claim 19 comprising components A, B, C, D, and E in the following amounts: (A): 20 to 35 wt.-%; (B): 52 to 68 wt.-%; (C): 2.0 to 3.9 wt.-%; (D): 3.0 to 4.8 wt.-%; and (E): 0.1 to 5.0 wt.-%.

21. The thermoplastic molding composition according to claim 19 comprising components A, B, C, D, and E in the following amounts: (A): 26 to 33 wt.-%; (B): 55 to 65 wt.-%; (C): 2.2 to 3.2 wt.-%; (D): 3.5 to 4.8 wt.-%; and (E): 0.1 to 5.0 wt.-%.

22. The thermoplastic molding composition according to claim 19 wherein graft copolymer (A) consists of 35 to 55 wt.-% of the graft sheath (A2) and 45 to 65 wt.-%, of the graft substrate (A1); wherein graft copolymer (A) is obtained by emulsion polymerization of styrene and acrylonitrile in a weight ratio of 80:20 to 65:35, to obtain a graft sheath (A2); and the starting butadiene rubber latex (S-A1) consists of 85 to 98 wt.-% of butadiene and 2 to 15 wt.-% styrene.

23. The thermoplastic molding composition according to claim 19 wherein the agglomerated butadiene rubber latex (A1) of graft copolymer (A) has a bimodal particle size distribution and is a mixture of at least one agglomerated rubber latex (A1-1) having a median weight particle diameter D50 of 150 to 350 nm, and at least one agglomerated rubber latex (A1-2) having a median weight particle diameter D50 of 425 to 650.

24. The thermoplastic molding composition according to claim 19 wherein graft copolymer (A) is prepared by a process comprising the steps: a) synthesis of starting butadiene rubber latex (S-A1) by emulsion polymerization, β) agglomeration of latex (S-A1) to obtain the agglomerated butadiene rubber latex (A1), γ) grafting of the agglomerated butadiene rubber latex (A1) to form a graft copolymer (A), and δ) coagulation of the graft copolymer (A).

25. The thermoplastic molding composition according to claim 24 wherein in coagulation step δ) a metal salt solution is used.

26. The thermoplastic molding composition according to claim 19 wherein the elastomeric block B/S of block copolymer (C) is composed of 60 to 30 wt.-% of vinylaromatic monomer and 40 to 70 wt.-% of diene.

27. The thermoplastic molding composition according to claim 19 wherein block copolymer (C) is made from 25 to 39 wt.-% of diene and 75 to 61 wt.-% of the vinylaromatic monomer.

28. The thermoplastic molding composition according to claim 19 wherein block copolymer (C) is one of the general formulae S-(B/S)-S, X-[-(B/S)-S].sub.2, and Y-[-(B/S)-S].sub.2, wherein X is the radical of an n-functional initiator, Y is the radical of an m-functional coupling agent, m and n are natural numbers from 1 to 10, and S and B/S are as defined according to claim 19.

29. The thermoplastic molding composition according to claim 19 wherein the titanium dioxide pigment (D) is modified by an organic treatment and has hydrophilic properties.

30. The thermoplastic molding composition according to claim 19 wherein the titanium dioxide pigment (D) comprises at least 96 wt.-% titanium dioxide and 2.0 to 3.2 wt.-% alumina, provided that silica is not present.

31. The thermoplastic molding composition according to claim 19 wherein component (E) is at least one lubricant, antioxidant, colorant, and/or pigment, except white pigments.

32. A process for the preparation of the thermoplastic molding composition according to claim 19 by melt mixing the components (A), (B), (C), (D), and, if present, (E) at temperatures ranging from 160° C. to 300° C.

33. A method of producing shaped articles, comprising the thermoplastic molding composition according to claim 19.

34. A sheet extruded and/or thermoformed article made from the thermoplastic molding composition according to claim 19.

35. Automotive and household applications comprising the sheet extruded and/or thermoformed article according to claim 34.

36. An inner liner in cooling apparatuses comprising the sheet extruded and/or thermoformed article according to claim 34.

Description

EXAMPLES

[0184] Test Methods

[0185] Particle Size Dw/D.sub.50

[0186] 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.

[0187] 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) [0188] n.sub.i: number of particles of diameter d.sub.i.

[0189] Molar Mass M.sub.w

[0190] 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.

[0191] Tensile Strength (TS) and Tensile Modulus (TM) Test

[0192] Tensile test (ASTM D 638) of ABS blends was carried out at 23° C. using a Universal testing Machine (UTM) of Lloyd Instruments, UK.

[0193] Flexural Strength (FS) and Flexural Modulus (FM) Test

[0194] Flexural test of ABS blends (ASTM D 790 standard) was carried out at 23° C. using a UTM of Lloyd Instruments, UK.

[0195] Notched Izod Impact Strength (NIIS) Test

[0196] Izod impact tests were performed on notched specimens (ASTM D 256 standard) using an instrument of CEAST (part of Instron's product line), Italy.

[0197] Melt Flow Index (MFI) or Melt Volume Flow Rate (MFR)

[0198] MFI/MFR test was performed on ABS pellets (ISO 1133 standard, ASTM 1238, 220° C./10 kg load) using a MFI-machine of CEAST, Italy.

[0199] ESCR Test Method

[0200] Chemical resistance of the ABS grade with respect to the blowing agent cyclopentane is determined as follows: In this test metal jigs are prepared for a particular fiber strain. Tests for 1.5, 2.5 and 100 percent fiber strain (180° bending) of standard test bars have been done. The test is performed by bending rectangular shaped samples (3.2 mm×12.7 mm×128 mm) on a jig with an imposed outer fiber strain of 1.5% and 2.5% and immersing it in n-cyclopentane for 30 seconds at 23° C. After removing from cyclopentane, the sample is allowed to stay on the jig with imposed strain for another 90 seconds. Then it is removed from the jig and bent manually to 180°.

[0201] The determination of chemical resistance was done optically in dependence of the following criteria: complete crack, partial crack, surface crack, edge crack, and surface quality after aging.

[0202] A summary is then given by the following symbols:

[0203] .box-tangle-solidup.: highly affected (break, complete crack) .box-tangle-solidup. .box-tangle-solidup.: affected .box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup.: a little affected .box-tangle-solidup. .box-tangle-solidup. .box-tangle-solidup. .box-tangle-solidup.: not affected

[0204] Thermal Stability Test Method

[0205] In this test the thermal stability of the product in terms of deterioration in color index is determined. For this, the color index of the sheet is measured for each successive extrusion trial and the color variation (b value) is measured. Sheets are extruded at various temperatures and color coordinates as well as gloss are measured to check the degree of deterioration of optical parameters with increase of melt temperature.

[0206] Delamination Test Method

[0207] In general delamination is a localized defect caused by excessive lubricants or due to perturbance of the molding parameters. However, it is possible to correlate the delamination strength to the ABS molding composition, where the bonding between the polymer chains or molecular layers contributes to the peeling resistance.

[0208] A homogeneous sheet of uniform thickness (0.70 to 0.75 mm) is made and two of such sheets of same width (29 to 30 mm) and thickness (0.70 to 0.75 mm) are fused by compression molding (hydraulic press: temperature (° C.) 175+/−5; pressure (kg/cm.sup.2) 1-2; time (s) 30+/−5) to make a single fused sheet with two free edges to fix to the grip of a universal testing machine (UTM) of Instron, UK.

[0209] Delamination UTM specification (initial distance between the grip is 115 mm. The test is done for a total strain of 50 mm at cross head speed of 5.0 mm/min) The two free edges are pulled in UTM with constant force and the sheet is allowed to delaminate in the “fused region”. The maximum strength recorded is taken as delamination strength for the composition.

[0210] Migration Test Method

[0211] The specific migration of acrylonitrile and 1,3 butadiene in samples of ABS molding compositions (sheet thickness: 2.6 mm) was tested with reference to EN 13130-1:2004 (test method for the specific migration of substances from plastics to foods and food simulants and the determination of substances in plastics) by treatment with one of the following three stimulating agents: 3% acetic acid, 95% ethanol and isooctane, at 5° C. for 10 days. The analysis was performed by Headspace (HS) GC-MS.

[0212] Materials Used:

[0213] Component (A)

[0214] Graft Copolymer (A)-1 (=R1)

[0215] Preparation of the Fine-Particle Butadiene Rubber Latex (S-A1-1)

[0216] The fine-particle butadiene rubber latex (S-A1-1) 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-A1-1) 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.

[0217] 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-A1-1) is characterized by the following parameters, see table 1.

[0218] 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-A1-1 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 0.10 on monomers) 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

[0219] W=decomposed potassium persulfate [parts per 100 parts rubber]

[0220] S=salt amount in percent relative to the weight of solids of the rubber latex

[0221] Dw=weight average particle size (=median particle diameter D.sub.50) of the fine-particle butadiene rubber latex (S-A1)

[0222] Production of the Coarse-Particle, Agglomerated Butadiene Rubber Latices (A1)

[0223] 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 (S-A1) 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-A1-1 S-A1-1 concentration latex S-A1 wt.- % 37.4 37.4 before agglomeration 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

[0224] Production of the Graft Copolymer (A)-1 (=R1)

[0225] 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.

[0226] 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.

[0227] 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.

[0228] 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.-%).

[0229] The obtained product is graft copolymer (A)-1 (=R1).

[0230] Graft Copolymer (A)-2 (=R2)

[0231] Preparation of the Fine-Particle Butadiene Rubber Latex (S-A1-2)

[0232] The particulate cross-linked fine-particle rubber latex used for the preparation of component A (graft copolymer) was prepared by radical emulsion polymerization of butadiene and styrene (monomer weight ratio 90/10) in the presence of distilled tallow fatty acid (CAS-No. 67701-06-8, C14-C18-saturated and C15-C18-unsaturated straight chain aliphatic monocarboxylic acid), tert-dodecylmercaptan as chain transfer agent, potassium persulfate as initiator at temperatures from 60° to 85° C. As salt tetrasodium pyrophosphate is used.

[0233] The addition of initiator marked the beginning of the polymerization. Finally the fine-particle butadiene rubber latexes are 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.

[0234] The starting butadiene rubber latex (S-A1-2) so obtained has solid content of 41 wt.-%, a rubber gel content of 93% (wire cage method in toluene), a rubber composition comprising units derived from styrene and butadiene in a weight ratio of 10/90 and a weight-average particle size of 0.08 μm (determined via Differential Centrifugation using a disc centrifuge from CPS Instruments).

[0235] The starting butadiene rubber latex (S-A1-2) was subjected to particle size enlargement with acetic anhydride in two batches to a weight-average particle size D.sub.w of 0.25 μm and 0.55 μm, respectively.

[0236] In order to achieve agglomerated butadiene rubber latices (A1-3) with D.sub.w of 0.25 μm, the fine-particle butadiene rubber latices (S-A1-2) are being provided first at 25° C. and are adjusted if necessary with deionized water to a concentration of 36 wt.-% and stirred. The temperature was raised to 40° C. To this dispersion, 1.3 weight parts of acetic anhydride based on 100 parts of the solids from the fine-particle butadiene rubber latex as aqueous mixture is added and mixed with the latex. After this the agglomeration is carried out for 10 minutes without stirring. Anionic dispersant of sulfonic polyelectrolyte type (Sodium naphthalene sulfonate formaldehyde condensates, CAS 9084-06-04) are added as aqueous solution to the agglomerated latex and mixed by stirring. Subsequently KOH are added as aqueous solution to the agglomerated latex and mixed by stirring. The solid content of the agglomerated butadiene rubber latex (A1-3) with D.sub.w of 0.25 μm is 28.5 wt.-%.

[0237] In order to achieve agglomerated butadiene rubber latices with D.sub.w of 0.55 μm, the fine-particle butadiene rubber latices (S-A1-2) are being provided first at 25° C. and are adjusted if necessary with deionized water to a concentration of 33 wt. % and stirred.

[0238] To this dispersion, 2 weight parts of acetic anhydride based on 100 parts of the solids from the fine-particle butadiene rubber latex as aqueous mixture is added and mixed with the latex. After this the agglomeration is carried out for 30 minutes without stirring. Anionic dispersant of sulfonic polyelectrolyte type (Sodium naphthalene sulfonate formaldehyde condensates, CAS 9084-06-04) are added as aqueous solution to the agglomerated latex and mixed by stirring. Subsequently KOH are added as aqueous solution to the agglomerated latex and mixed by stirring. The solid content of the agglomerated butadiene rubber latex (A1-4) with D.sub.w of 0.55 μm is 24.7 wt.-%. The two latices with 0.25 μm (80 pbw A1-3) and 0.55 μm (20 pbw A1-4) were combined to the agglomerated rubber latex A1-5 which is used in the further reaction step in the form of polymer latexes which have a solids content of 26 wt.-%.

[0239] Preparation of the Graft Copolymer (A)-2 (=R2)

[0240] The graft copolymer (A)-2 is prepared (as parts by weight) from 52 styrene/butadiene-rubber, 34 styrene, 14 acrylonitrile, together with cumene hydroperoxide, dextrose, ferrous sulfate, t-dodecylmercaptane, disproportionated potassium rosinate soap, and emulsion graft polymerization was conducted.

[0241] Firstly, the afore-mentioned agglomerated rubber latex A1-5 was charged, and the temperature was raised to 70° C. Styrene, acrylonitrile, t-dodecylmercaptane, disproportionated potassium rosinate soap and deionized water were added. At 70° C., the catalyst solution (sodium pyrophosphate, dextrose, cumene hydroperoxide and ferrous sulfate dissolved in water) was added. After completion of the addition, the stirring was continued for further 30 minutes, and then the mixture was cooled. To the graft copolymer latex thus obtained, an aging-preventive agent (e.g. Antioxidant PL/Wingstay L, Phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutene, CAS-No. 68610-51-5) was added, and the mixture was added under stirring to an aqueous magnesium sulfate solution heated to 95° C., for coagulation. The coagulated product was washed with water and dried to obtain a high rubber content resin composition in the form of a white powder.

[0242] Component (B)

[0243] Statistical copolymer (B-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) (220° C./10 kg load) of 6 to 7 mL/10 minutes, produced by free radical solution polymerization.

[0244] Component (C)

[0245] C-I: Styroflex®2G66 (styrene butadiene block copolymer) from Ineos Styrolution, Germany.

[0246] Component (D)

[0247] D-I (=P9): Titanium dioxide pigment grade R-103® from the Chemours Company, Singapore.

[0248] D-II (=P1)—TiO.sub.2 grade R-350® (TiO2/alumina/silica: 95/1.7/3.0 wt.-%, hydrophobic) (from The Chemours Company)

[0249] D-III (=P5)—TDR 60—TiO.sub.2 grade R-350 60% master batch in SAN-copolymer (From SM Chemical Corporation).

[0250] Component (E)

[0251] E-1—ethylene bis stearamide, primary lubricant (from Palmamide SDN BHD)

[0252] E-2—Licowax®, external lubricant—wax based on PE chemistry (from Clariant Chemicals (India) Limited)

[0253] E-3—MgO—metal oxide as acid scavenger (from Kyowa chemical industry co. Ltd)

[0254] E-4—polydimethylsiloxane with kinematic viscosity of 30000 cSt (from K.K. Chempro India Pvt Ltd.)

[0255] E-5—Kinox® 68-A phosphate based stabilizer (from HPL Additives Ltd)

[0256] E-6—Irganox® 1076, a phenolic based antioxidant (from HPL Additives Ltd)

[0257] E-7—distearyl thiodipropionate (from Omtech Chemicals Industries Pvt Ltd)

[0258] E-8—distearyl penta erythritol diphosphate (from Addivant Switzerland GmbH)

[0259] E-10 (=P2)—Blue RLS (from Clariant Chemicals (India) Ltd)

[0260] E-11 (=P3)—Red YP (from Philoden Industries Pvt Ltd)

[0261] E-12 (=P4)—Telalux KSN—Optical brightener (from Clariant Chemicals (India) Limited)

[0262] E-14 (=P6)—UM Blue (from Ultramarine & Pigments Ltd.)

[0263] E-15 (=P7)—VIOLET FBL (from Parshwnath Dye Chem Ind. Pvt. Ltd)

[0264] E-16 (=P8)—Violet RRR (from Parshwnath Dye Chem Ind. Pvt. Ltd)

[0265] E-17 (=P10)—TiO.sub.2 grade R-105 (TiO.sub.2/alumina/silica: 92/1.7/3.5 wt.-%, hydrophobic) (from The Chemours Company)

[0266] Thermoplastic Compositions

[0267] Graft copolymers R1 or R2, SAN-copolymer (B-I), SBC-block copolymer (C-1), component (D-1) and the further additives E-1 to E-17 were mixed (composition see Tables 1 and 5, batch size 5 kg) for 2 minutes in a high speed mixer to obtain good dispersion and 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 190 to 220° C. for the different barrel zones.

[0268] The extruded strands were cooled in a water bath, air-dried and pelletized.

[0269] Standard test specimens (ASTM test bars) of the obtained blend were injection molded at a temperature of 190 to 230° C. and test specimens were prepared for mechanical testing.

[0270] The test results are presented in Tables 2 and 6.

TABLE-US-00003 TABLE 1 Molding Compositions A to H with different SBC-content (in wt.-%) D Composition A B C (Plant trial) E F G H Graft copolymer (RI) 28.24 28.24 28.24 28.13 28.24 28.24 28.18 28.19 SBC (C-I) 1.41 2.82 2.81 3.76 4.71 6.58 9.40 SAN copolymer (B-I) 65.88 64.47 63.06 62.83 62.12 61.18 59.18 56.37 El 1.41 1.41 1.41 1.41 1.41 1.41 1.41 1.41 E-2 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28 E-3 0.19 0.19 0.19 0.38 0.19 0.19 0.19 0.19 E-4 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 E-5 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 P-1 (D-II) 3.76 3.76 3.76 3.94 3.76 3.76 3.95 3.95 P-2 0.0014 0.0014 0.0014 0.0015 0.0014 0.0014 0.0014 0.0014 P-3 0.019 0.019 0.019 0.010 0.019 0.019 0.019 0.010 P-4 0.00015 Total % 100 100 100 100 100 100 100 100

TABLE-US-00004 TABLE 2 Properties of Molding Compositions A to H with different SBC-content Properties of molding composition A to H ABS RS D Details of Tests Performed 670* A B C (Plant Trial) E F G H ESCR Test Fiber Strain 1.50% .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. Resuits Cyclopen using Jig .box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. tane 2.50% .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. 180° 100% .box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. Bending .box-tangle-solidup. .box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. MFI 5 6.9 7 7.4 5 8 7.9 7 8 Mechanical NIIS ,1/4″ 36 28.5 31.5 35.5 40.5 36.5 39.5 43.5 42.5 properties NIIS, 1/8″ 43 32 37 43 50 45 48 50 30 Tensile Strength 485 510 500 500 510 490 470 435 400 Flexural Strength 900 895 880 860 865 845 815 745 685 Flexural Modulus 30K 30K 29K 28K 27K 27K 26K 24K 22K Color data L 93.6 92.8 92.5 92.7 94.2 92.8 92.5 93.1 93.0 A −2.15 −1.61 −1.71 −1.7 −1.7 −1.9 −1.8 −1.6 −1.6 B −2.04 −2.43 −2.46 −2.4 −2.3 −2.6 −2.5 −3.4 −3.6 Yellowness Index −5.67 −6.1 −6.26 −6.1 −5.8 −6.6 −6.4 −8.1 −8.5 Legend .box-tangle-solidup.: highly affected (Break) .box-tangle-solidup..box-tangle-solidup.: affected .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup.: a little affected .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup.: not affected *extrusion molding grade for refrigerator inner liners commercially available from LG Chem

[0271] The properties of ABS molding compositions A to H comprising different amounts of SBC (C-I) are shown in Table 2. The studies show an optimum amount of SBC (C-I) in the range of 2.8 to 4.7 wt.-%, in particular in the range of 2.8 to 3.8 wt.-%, considering both mechanical properties and the chemical resistance boosted by compatibilization achieved by a synergistic effect.

TABLE-US-00005 TABLE 3 The effect of the SBC-content on the delamination of compressed sheets of molding compositions A to H Molding compositions A to H Details of Tests Performed ABS RS 670* A B D E F G H Delamination Max. Load 14.1 15.3 14.9 12.7 8.9 6.4 3.6 force on fused sheet (kgf) specimen Tensile at Yield 36.3 40.6 32.5 32.2 25.8 17.5 8.6 (kg/cm.sup.2)

[0272] Fused specimens of the ABS blends A to H (having different SBC content) were prepared and were tested in a universal testing machine for the delamination force. Table 3 shows that the blend D having a SBC content of 2.81 wt.-% has a high binding adhesion (low tendency to delamination) and has the best overall properties (cp. Table 2) of the tested blends A to H.

[0273] Furthermore, injection molded specimens of blends A to H were prepared using an injection molding machine as per the standard molding parameters and the delamination was studied.

[0274] FIG. 1 shows the delamination of molded specimens, in particular the formation of layered structures in molded specimens made from blends having a SBC content of 6.58 wt.-% and more. Delamination was only observed in the case of blends having a higher SBC content (6.58 wt.-% and more, cp. Table 4 below). The problem is severe and the layer can be easily peeled off from the surface of specimens.

TABLE-US-00006 TABLE 4 The effect of the SBC-content on the delamination of injection molded specimens of molding compositions A to H Molding composition A to H Details of Tests ABS RS 670* A B D E F G H Delamination of molded No No No No No No Yes Yes specimen

[0275] Molding Compositions with a different graft copolymer R1 or R2 and different titanium dioxide pigments were prepared and tested. The composition of said blends is shown in Table 5 and the obtained test results are presented in Table 6.

TABLE-US-00007 TABLE 5 Molding Compositions with different graft copolymer R1 or R2 and different titanium dioxide pigments Example Exam- Exam- Exam- com- 1 (non- Example ple ple ple position inventive) 2 3 4 5 Graft 28.40 27.95 copolymer R1 Graft 28.00 28.20 28.27 copolymer R2 SAN (B-I) 66.27 59.44 62.50 62.90 63.13 SBC (C-I)  2.80 2.80 2.80 2.80 E-1 0.38  1.49 1.40 1.40 1.40 E-2  0.28 E-3 0.095   0.093 E-4 0.142   0.116 0.23 0.23 0.23 E-5 0.189   0.000 0.37 0.38 — E-6 0.38 0.19 0.19 — E-7 0.14 E-8  0.37 — 0.23 P2     0.00056 0.00206 0.0015 0.00139 P5 (D-III)    7.45** P6 0.029 P7    0.0016 0.00049 0.00056 0.057 P8 0.00098 P9 (D-I) 4.48 3.94 3.89 P10 3.98 Total % 100 100     100 100 100 Com- position **content TiO.sub.2 4.47 wt.- %

TABLE-US-00008 TABLE 6 Properties of Molding Compositions with different graft copolymer R1 or R2 and different titanium dioxide pigments Example 1 (non- Details of Tests Performed ABS RS 670 inventive) Example 2 Example 3 Example 4 Example 5 ESCR Test Fiber Strain 1.50% .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. Results using Jig 2.50% .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. Cyclopen- 180°  100% .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. tane Bending MFI 5 6.9 7 4.5 4.5 4.4 Mechanical NIIS, 1/4″ 36 28.5 31.5 34.5 33 34 properties NIIS, 1/8″ 43 32 37 49 49.5 49 Tensile Strength 485 510 500 498 520 480 Flexural Strength 900 895 880 880 880 825 Flexural Modulus 30K 30K 28K 27K 27K 26K Color data L 93.6 92.8 92.7 93.6 93.6 94.0 A −2.15 −1.61 −1.7 −2.32 −1.97 −2.07 B −2.04 −2.43 −2.4 −2.26 −2.13 −2.29 Yellowness Index −5.67 −6.1 −6.1 −5.81 −5.76 −6.12 Legend .box-tangle-solidup.: highly affected ( Break ) .box-tangle-solidup..box-tangle-solidup.: affected .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup. a little affected .box-tangle-solidup..box-tangle-solidup..box-tangle-solidup..box-tangle-solidup.: not affected

[0276] All blends (SBC content 2.8 wt.-%) of inventive examples 2 to 5 show an improved chemical resistance to foam blowing agents in comparison to prior art blends. Moreover, the blends of examples 3 to 5 (comprising graft copolymer R2 and titanium dioxide pigment P9) show a superior resistance to foam blowing agents and further improved mechanical properties such as a high notched izod impact strength and a very high flexural strength.

[0277] The color stability of molding compositions comprising graft copolymer R2 and different titanium dioxide pigments was tested. The obtained results are shown in Table 6A.

TABLE-US-00009 TABLE 6A Molding compositions comprising different titanium dioxide pigments ABS Composition (wt.- %) RS 670* Example Example Example Reference 6 7 8 Graft 30 30 30 copolymer R2 B-I 67 67 67 C-I 3 3 3 E17 (TIO2 R-105) 4.8 — — D-II (TIO2-R-350) — 4.8 — D-I (TIO2 R 103) — — 4.8 Properties L 93.44 92.43 92.67 93.19 a −2.1 −1.53 −2.23 −2.09 b −1.99 −1.92 −2.65 −2.12 Delta E 0.44 0.75 1.01 0.24

[0278] The optical performance of the molding composition of Example 8 which comprises a titanium dioxide pigment of grade R-103 is excellent as evidenced by the low delta E value (cp. Table 6A). The data show the superiority of Example 8 in comparison to the molding compositions of Examples 6 and 7 with other titanium dioxide pigments.

[0279] The thermal stability of a molding composition according to Example 5 was tested under different extrusion conditions, in particular at different die head (DH) temperatures (cp. Table 7).

TABLE-US-00010 TABLE 7 Thermal Stability Test L A B Yellowness DE ABS RS 670 molded plaques 93.23 −1.98 −1.91 −5.34 0.3 Example 5 molded plaques 93.58 −2.23 −2.23 −5.89 0.51 Extruded sheet prepared at different DH temperature Yellow- Delta DH Temperature L*** A*** B*** ness yellowness ΔL*** Δa*** Δb*** ΔE*** Example 5 238° C. 93.23 −2.31 −1.99 −5.75 −0.41 −0.01 −0.33 0.07 0.34 Example 5 240° C. 93.19 −2.29 −1.99 −5.76 −0.41 −0.05 −0.32 −0.08 0.33 Example 5 255° C. 93.04 −2.28 −1.85 −5.48 −0.13 −0.20 −0.30 0.06 0.37 Example 45 265° C. 93.04 −2.41 −1.36 -4.58 0.77 −0.19 −0.43 0.55 0.73 ABS RS 670 at different DH temperature ABS RS 670 238° C. 92.51 −1.87 −1.55 -4.58 0.76 −0.73 0.10 0.36 0.82 ABS RS 670 240° C. 92.34 −1.72 −1.35 -4.06 1.28 −0.90 0.26 0.56 1.09 ABS RS 670 255° C. 92.42 −1.88 −1.41 -4.29 1.05 −0.82 0.10 0.50 0.96 ABS RS 670 265° C. 92.27 −1.93 −1.16 −3.84 1.95 −0.75 0.01 0.98 1.23

[0280] The optical parameters (L a b) of these extruded sheets at different die head temperature is compared with that of standard molded plaques (ABS RS 670). Delta E (DE, ΔE) is a calculated value showing the color difference.

[0281] The L, a, b color space is a three dimensional rectangular color space based on the opponent color theory (CIE Method). [0282] L (Lightness) Axis—0 is black, 100 is White. [0283] a (Red-Green) Axis—Positive values are red; negative values are green and 0 is neutral. [0284] b (Blue-Yellow) Axis—Positive values are yellow; negative values are blue and 0 is neutral. [0285] Delta E*** (Total Color Difference)—is based on L***, a***, b*** color differences and was intend to be a single number metric for Pass/Fail decisions. If sample is having L, a, b values measured by Spectrophotometer as; L.sub.S, A.sub.S, B.sub.S and reference is having L, a, b values as; L.sub.R, A.sub.R, B.sub.R then DE is calculated as below;

DE=√{square root over ((L.sub.R−L.sub.S).sup.2+(A.sub.R−A.sub.S).sup.2+(B.sub.R−B.sub.S).sup.2)}

[0286] The molding composition according to Example 5 showed a superior performance in comparison to samples of a commercial product (ABS RS 670 from LG Chem). The commercial molding composition showed a higher yellowing (higher value of yellowness). For example, at 265° DH temperature, the molding composition according to the invention has a yellowness value of −4.58 while that of the commercial molding composition is −3.84 (higher the value, higher the yellowness which is undesirable).

[0287] In the following the migration of residuals was tested (cp. Table 8). The molding composition according to Example 5 was analyzed for the leaching or diffusion of residuals to understand the chemical resistance as well as to comply with the food regulations.

TABLE-US-00011 TABLE 8 Migration test of molding composition of Exampe 5 Reporting Permissible Test Simulant Specific Result Limit limit No. used Migration (mg/kg ) (mg/kg) (mg/kg) Conclusion 1 3% Acetic Acid (W/V) 1, 3 Butadiene Not detected 0.1 1 Pass aqueous solution 95% 1, 3 Butadiene Not detected 0.1 1 Pass Ethanol ISO Octane 1, 3 Butadiene Not detected 0.1 1 Pass 2 3% Acetic Acid (W/V) aqueous Acrylonitrile Not detected 0.01 0.01 Pass solution 95% Acrylonitrile Not detected 0.01 0.01 Pass Ethanol ISO Octane Acrylonitrile Not detected 0.01 0.01 Pass Note: 1. mg/kg= milligram per kilogram of foodstuff in contact with 2. Permissible limit is according to Commission Regulation (EU) No 10/2011 of 14 Jan. 2011 with amendments.

[0288] It was found that under the specified conditions prescribed by EU norms, there is no detectable amount of residuals found in different simulates. This proves that the molding composition according to Example 5 is excellent for the use in refrigerator liners.

[0289] The following are test results (see Tables 9 to 12) of large-scale trials wherein the compositions according to the invention were used. For this purpose the composition according to Example 5 was tested for various properties at one of reputed sheet extrusion and thermoforming firm and the following results were obtained. Initially extruded sheets with a thickness of 3.0 mm and dimension (as per ASTM) were prepared and the following properties are measured (cp. Table 9).

TABLE-US-00012 TABLE 9 Mechanical testing of compositions according to Example 5 after commercial sheet extrusion Sample Approval Test Item Specification Quantity No. 1 No. 2 No. 3 No. 4 No. 5 Average Judgement Specific 1.051~1.081 1 1.068 1.068 OK gravity Specific 1.051~1.081 1 1.069 1.069 OK gravity Izod 15 kg.Math.cm/cm↑ 5 18.6 17.9 19.2 18.6 18.6 18.58 OK Impact(MD) Izod 15 kg.Math.cm/cm↑ 5 16.5 15.6 15.6 15.9 15.6 15.84 OK Impact(MD) Izod 15 kg.Math.cm/cm↑ 5 28.7 29.4 28.7 28.7 28.1 28.72 OK Impact(TD) Izod 15 kg.Math.cm/cm↑ 5 35.6 34.9 36.2 36.8 35.6 35.82 OK Impact (TD)

[0290] The performance of the molding composition is found to be good (cp. Table 9).

[0291] Table 10 shows the color difference of an extruded sheet and a thermoforming component prepared from a composition of Example 5 in comparison to a prior art blend (ABS RS 670).

TABLE-US-00013 TABLE 10 Color measurements after sheet extrusion and thermoforming commercial trial sample L a b Delta L Delta a Delta b Delta E ABS RS670 sheet 92.51 −2.14 −1.21 Example 5 sheet 93.59 −2.41 −1.60 ABS RS 670 92.48 −2.05 −0.78 0.03 −0.09 −0.43 0.44 thermoforming component Example 5 92.86 −1.95 −1.15 −0.33 0.15 0.63 0.72 thermoforming component

[0292] The yellowness reduction—indicated by the b values—of the inventive molding composition is better compared to the prior art blend. The b value is the most concerned parameter in the production of refrigerator inner liners.

[0293] Table 11 shows gloss measurements of two thermoformed models prepared from a composition of Example 5 in comparison to a prior art blend (ABS RS 670).

TABLE-US-00014 TABLE 11 Gloss measurements after thermoforming Gloss % Location Grade Top Right Left Bottom Center Average Judge Refrigerator ABS RS 670 88.85 85.95 86.9 84.95 91.4 87.61 Pass Example 5 86.3 77.25 83.75 85.05 90.5 84.57 Pass Freezer ABS RS 670 84.1 76.7 91.3 76 60.75 77.77 Pass Example 5 80.65 86.5 88.4 71 61.95 77.7 Pass [0294] The gloss is found to be good.

[0295] Extruded sheets prepared from a composition of Example 5 were tested for their UV stability. The measurement method is shown below and results are shown in Table 12. [0296] Equipment: Portable UV Cabinet [0297] UV lamps Details: UVA 366 nm, 8 W and UVC 254 nm, 7 W (both kept on) [0298] Sample distance: 50 mm from the source [0299] Temperature: 26° C. [0300] Total Exposure time: 24 hours [0301] Results by: Data Color Spectrophotometer 850

TABLE-US-00015 TABLE 12 UV stability of a composition according to Example 5 Time of UV exposure L a b Delta L Delta a Delta b Delta E 0 hours 93.09 −2.09 −1.07          8 hrs 93.02 −1.96 −1.25 0.07 −0.13 0.18 0.23 16 hrs 93.03 −1.94 −1.33 0.06 −0.15 0.26 0.31 24 hrs 93.07 −1.91 −1.37 0.02 −0.18 0.3 0.35

[0302] The data show—indicated by a low change of all tested values—that the molding composition according to Example 5 exhibits a high UV stability which is required for many automotive and household applications.