Title of Invention: Thermoplastic moulding compounds
Abstract: The invention relates to thermoplastic molding compositions comprising. A) from 30 to 98% by weight of a graft copolymer comprising PA1 B) from 1 to 50% by weight of a thermoplastic polymer and PA1 C) from 1 to 70% by weight of an elastomeric block copolymer prepared by anionic polymerization of the monomers with addition of a potassium compound soluble in non-polar solvents (Step 1) followed by hydrogenation of all or virtually all the olefinic double bonds of the polymer obtained in Step 1, as described in greater detail herein.. a.sub.K) from 30 to 90% by weight of an elastomeric graft core, PA2 a.sub.S) from 10 to 70% by weight of a graft shell comprising. a.sub.S /1) from 50 to 100% by weight of a styrene compound or a C.sub.1 -C.sub.8 -alkyl acrylate or methacrylate, or a mixture thereof, and PA3 a.sub.S /2) from 0 to 50% by weight of one or more other monomers,
Detailed Description: Part PAC: EXAMPLES
Part PAR: The following components were prepared and/or used (percentages are by weight)
Part PAL: Component A):
Part PAR_2: Particulate graft copolymer comprising crosslinked poly-n-butyl acrylate (core) and styrene-acrylonitrile copolymer (shell)
Part PAR_3: A mixture of 98 g of n-butyl acrylate and 2 g of dihydrodicyclopentadienyl acrylate and, separately, a solution of 1 g of sodium C.sub.12 -C.sub.18 -paraffinsulfonate in 50 g of water were added to a mixture of 3 g of a polybutyl acrylate seed latex, 100 g of water and 0.2 g of potassium persulfate, over 4 andersonemily@example.org. C., after which the polymerization was continued for a further 3 hours. The latex obtained had a mean particle diameter d.sub.50 of 430 nm with a narrow particle size distribution (Q=0.1).
Part PAR_4: 150 g of this latex were mixed with 60 g of water, 0.03 g of potassium persulfate and 0.05 g of lauroyl peroxide, after which, over a period of 3 andersonemily@example.org. C., 20 g of styrene and then, over a period of a further 4 hours, a mixture of 15 g of styrene and 5 g of acrylonitrile were grafted onto the latex particles. The polymer was then precipitated using a calcium chloride andersonemily@example.org. C., separated, washed with water and dried in a stream of warm air. The degree of grafting of the polymer was 35% and the particles had a mean diameter d.sub.50 of 510 nm.
Part PAR_5: The graft copolymer had the following composition (rounded values):
Part PA0: 60% by weight of a graft core of polybutyl acrylate, crosslinked, PA0 20% by weight of an inner graft of styrene polymer and PA0 20% by weight of an outer graft of styrene-acrylonitrile copolymer with weight ratio S/AN 3:1. PA0 Tensile strength: the tensile test was carried out according to DIN 53 504 on S 2 tensile specimens stamped out of the film. PA0 Elongation at break: the elongation at the moment of application of breaking stress was measured in the tensile test according to DIN 53 504 and stated as % of the original dimension of the S 2 tensile specimens. PA0 Tear strength: a Graves tear test, DIN 53 515, was carried out on stamped-out strips with V-shaped nicks. PA0 Shore hardness: the Shore hardness according to DIN 53 505 was determined using test apparatus D and A. PA0 Heat deflection temperature: determined according to DIN 53 461 as Vicat number using measurement method A.
Part PAR_6: The seed polymer used at the start was prepared by the process of EP-B 6503 (column 12, line 55, to column 13, line 22) by polymerization of n-butyl acrylate and tricyclodecenyl acrylate in aqueous emulsion, and had a solids content of 40%.
Part PAR_7: The mean particle size mentioned in the description of component A) is the weight average of the particle sizes.
Part PAR_8: The mean diameter corresponds to the d.sub.50 value, according to which 50% by weight of all particles have a smaller, and 50% by weight a larger, diameter than the diameter corresponding to the d.sub.50 value. In order to characterize the width of the particle size distribution, the d.sub.10 and the d.sub.90 values are often stated in addition to the d.sub.50 value. 10% by weight of all particles are smaller, and 90% by weight are larger, than the d.sub.10 diameter. Analogously, 90% by weight of all particles have a smaller, and 10% by weight a larger, diameter than the diameter corresponding to the d.sub.90 value. The quotient Q=(d.sub.90 -d.sub.10)/d.sub.50 is a measure of the width of the particle size distribution. The smaller is Q, the narrower is the distribution.
Part PAL_2: Component B):
Part PAL_3: Copolymer of styrene and acrylonitrile
Part PAR_9: A copolymer of 65% by weight of styrene and 35% by weight of acrylonitrile was prepared by the continuous solution polymerization process as described in Kunststoff-Handbuch, ed. R. Vieweg and G. Danmiller, Vol. V "Polystyrene", Carl-Hanser-Verlag Munich 1969, pp. 122 to 124. The viscosity number VN (determined according to DIN 53 andersonemily@example.org. C., 0.5% by weight in dimethylformamide) was 80 ml/g.
Part PAL_4: Component C) (according to the invention): elastomeric block copolymer
Part PAR_10: A heatable and coolable 50 1 stainless steel autoclave with cross-paddle stirrer was prepared by flushing with nitrogen and scalding with a solution of sec-butyllithium and 1,1-diphenylethylene (molar ratio 1:1) in cyclohexane, followed by drying.
Part PAR_11: The autoclave was filled with 22.8 1 of cyclohexane; 87.3 mmol of sec-butyllithium were then added, followed by the monomers necessary for the first step and finally a 10% strength by weight solution of 4.37 mmol of potassium tetrahydrolinaloolate in cyclohexane. The molar ratio Li:K was 20:1. Table 1 shows the individual steps of the polymerization.
Part PAR_12: In each step, the duration of the monomer feed was small in comparison with the duration of the polymerization. The stated starting and/or final temperatures were set by heating and/or cooling of the reactor jacket.
Part TBL: TABLE 1 ______________________________________ Step 1 2 3 4 5 ______________________________________ Butadiene feed [g] -- 1172 1172 1172 -- Styrene feed [g] 1048 1477 1477 1477 1048 T.sub.start [.degree. C.] (403)723-7513 T.sub.end [.degree. C.] (403)723-7513 Duration of (403)723-7513 polymerization [min] ______________________________________
Part PAR_13: At the end of the reaction (consumption of the monomers) the polymerization was terminated by titration with ethanol until the mixture was colorless, and the mixture was then acidified with a 1.5-fold excess of formic acid. 34 g of 2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]m ethyl]-4-methylphenyl acrylate (Irganox 3052, Ciba-Geigy) and 82 g of tris(nonylphenyl) phosphite were then added.
Part PAR_14: The proportion of 1,2-linkages of the diene, determined by FTIR spectroscopy, was 10.4%, based on the total of 1,2- and 1,4-linkages.
Part PAR_15: The hydrogenation catalyst was prepared by adding 50 ml of a 20% strength by weight solution of triisobutylaluminum in hexane to 250 ml of a 1.136% strength by weight solution of nickel acetylacetonate in toluene at room temperature (mass ratio nickel acetylacetonate:triisobutylaluminum about 1:4). When the weakly exothermic reaction was complete, the fresh catalyst solution was added to 13.3 kg of a 15% strength by weight solution of the resultant polymer, and the mixture was exposed for 16 andersonemily@example.org. C. to a hydrogen pressure of 15 bar. The degree of hydrogenation was determined by Wijs titration of a hydrogenated sample in comparison with an unhydrogenated sample and was 98%.
Part PAR_16: After the hydrogenation, a mixture of 12 ml of hydrogen peroxide, 2.5 ml of formic acid and 50 ml of water was added to the black andersonemily@example.org. C., whereupon the reactor contents immediately became colorless.
Part PAR_17: The work-up of the reaction mixture to give the hydrogenated polymer was carried out as usual; it was expedient to remove the solvent in a vented andersonemily@example.org. C. The product obtained was in granule form.
Part PAR_18: The polymer C) obtained had an EQU A-B/A-A
Part PAL_5: structure in which the soft phase B/A is subdivided into 3 blocks as in EQU (B/A).sub.1 -(B/A).sub.2 -(B/A).sub.3.
Part PAL_6: The terms A and B/A are taken to mean the polymer blocks already defined. Block A is a homopolystyrene block, block B/A is a block comprising randomly polymerized styrene and hydrogenated butadiene units. The proportion of butylene units in the soft phase B/A was 44% by weight, and the proportion of styrene units was 56% by weight.
Part PAR_19: The styrene proportion in the entire polymer C) was about 65% by weight.
Part PAR_20: The proportion of the two hard phases A in the polymer C) was in each case about 10.4% by weight, and the proportion of the soft phase B/A was correspondingly about 79.2% by weight.
Part PAR_21: The mean molar masses in g/mol of the polymers C) which were obtained were as follows: number-average M.sub.n =131,000, viscosity-average (peak maximum) M.sub.p =150,000, weight-average M.sub.w =166,000 (all molar masses were determined by gel permeation chromatography calibrated against polystyrene).
Part PAR_22: The glass transition temperatures T.sub.g were, before hydrogenation, from -45 to 0.degree. C. for the soft phases (blocks B/A) and from 50 to 90.degree. C. for the hard phases (blocks A), and after hydrogenation from -17 to +7.degree. C. for the soft phases, and unchanged values for the hard phases.
Part PAR_23: For determination of the mechanical properties of component C), sheets of thickness 2 cm were pressed from the granules (3 andersonemily@example.org. C.) out of which standard test specimens were stamped.
Part PAR_24: Table 2 shows the tests and results
Part TBL_2: TABLE 2 ______________________________________ Component C) before after Test DIN Norm hydrogenation hydrogenation ______________________________________ Yield stress [N/mm.sup.2 ] 43504 1.5 5.0 Breaking stress 43504 21.4 31.0 [N/mm.sup.2 ] Elongation at break 43504 801 352 [%] Stress at 200%/400%/ 43504 2.9/6.4/11.4 17.5/--/-- 600% elongation [N/mm.sup.2 ] ______________________________________
Part PAR_25: This shows that the strength increases after hydrogenation, as can be seen from the higher values for yield stress and breaking stress.
Part PAL_7: Component C*) (for comparison): hydrogenated styrene-butadiene copolymer
Part PAR_26: A solution of 520 g of styrene, 480 g of butadiene and 20 ml of tetrahydrofuran in 4 1 of andersonemily@example.org. C. was first mixed slowly with sec-butyllithium in order to deactivate protic impurities. After the start of polymerization, recognizable from a temperature rise of 0.2.degree. C., 0.8 g of sec-butyllithium was immediately added. The heat of polymerization was extracted by evaporative cooling, the rate of cooling being adjusted so that the temperature rose to 120.degree. C. over 30 min. This temperature was maintained for a further 10 min, after which the polymerization was terminated by adding 1 g of ethanol.
Part PAR_27: For hydrogenation, a suspension of 1.5 g of nickel(II) acetylacetonate in 30 ml of toluene and 34 ml of a 20% strength by weight solution of triisobutylaluminum in hexane were added to the resultant polymer solution, and the mixture was then exposed to a hydrogen pressure of 15 bar for 60 min at from 80 to 110.degree. C.
Part PAR_28: The work-up of the reaction mixture to give the hydrogenated polymer was carried out as usual; the solvent was expediently removed in a direct degassing apparatus.
Part PAR_29: The resultant polymer comprised a block which is butadiene-rich (styrene-poor) at its beginning and styrene-rich (butadiene-poor) at its end, i.e. there was a progression, and a homopolystyrene block attached to the styrene-rich end of the first block.
Part PAR_30: The styrene content of the resultant polymer, which is commercially obtainable as Glissoviscal.RTM. SG (BASF), was 52% by weight, based on the total weight of the polymer. The proportion in the polymer of homopolystyrene end-blocks was 13% by weight. The mean molar mass, determined by gel permeation chromatography, of the product prepared in the described manner was 80,000.
Part PAR_31: Novel compositions and their properties
Part PAR_32: Mixtures were prepared from components A), B) and C) or C*) and were converted on a roll andersonemily@example.org. C. into films of 1 mm thickness.
Part PAR_33: The following properties of the films were determined:
Part PAR_34: The formulations of the films which were produced, and the test results, are shown in Table 3.
Part TBL_3: TABLE 3 ______________________________________ Test No. 1V*) 2 3 ______________________________________ Formulation [% by weight]: A 80 80 70 B 10 10 15 C -- 10 15 C* 10 -- -- Properties Tensile strength [N/mm.sup.2 ] 14 17 20 Elongation at break [%] 140 170 176 Shore Hardness A 93 87 88 Shore Hardness D 47 44 47 Tear strength [N/mm.sup.2 ] 46 51 52 Heat deflection temperature: Vicat 89 86 90 A 50 [.degree. C] ______________________________________ *) for comparison
Part PAR_35: Films produced from molding compositions comprising a hydrogenated polymer C*) (butadiene-containing block with progression styrene-poor to styrene-rich, joined to a homopolystyrene block) in place of the polymer C) of the invention have a considerably lower elongation at break and a significantly lower tear strength (test 1V). In addition, these films are more rigid.
Part PAR_36: In contrast, films comprising the polymer C) of the invention (polystyrene block--3 random polymer blocks of styrene and hydrogenated butadiene--polystyrene block) combine good tensile strength, high elongation at break, good tear strength, low rigidity and high heat deflection temperature (tests 2 and 3).


{'bibliographic_information': "{'Patent Number': '061628670', 'Series Code': '9', 'Application Number': '2549166', 'Application Type': '1', 'Art unit': '171', 'Application Filing Date': '19990317', 'Title of Invention': 'Thermoplastic moulding compounds', 'Issue Date': '20001219', 'Number of Claims': '16', 'Exemplary Claim Number(s)': '1', 'Primary Examiner': 'Gorr; Rachel'}", 'source_file': './grant/2000/pftaps20001219_wk51.txt', 'source_data': 'USPTO-Grant'}