Graft copolymers for reducing interfacial stress in polymer blends

Description

[0001] The present invention relates to graft copolymers of a special architecture consisting of blocks of two polymers A and B with different chemical compositions, wherein one of the polymers is a polycondensation polymer selected from the group consisting of polycarbonates, polyester carbonates, polyesters, and polyamides, and the other polymer is a polymer of one or more different vinyl monomers. The invention further relates to the use of these graft copolymers for reducing the interfacial tension in mixtures containing homopolymers A and B or in mixtures of polymers with comparable polarity, compositions containing the graft copolymers as well as homopolymers A and B or polymers of comparable polarity, molding compounds produced from such compositions, and molded parts produced from these molding compounds.

[0002] Mixtures of immiscible polymers with different chemical compositions are suitable for producing multiphase polymer blends with properties that sometimes synergistically combine the specific application-related advantages of the two polymers. However, if the polarity differences between polymers A and B are too great, meaning the interfacial tension at the phase interface of the two polymers is too high, then the polymer blends tend to phase segregation. A resulting coarse and / or unstable phase morphology, or...Inadequate phase adhesion often leads to undesirable effects such as poor light transmission, phase delamination, insufficient processing stability, inadequate mechanical properties (e.g., material ductility / toughness, elongation at break, stress crack resistance, or weld line strength), cosmetic surface defects on components formed from the polymer blend via a thermoplastic processing method, especially those injection-molded under high shear, or delamination of decorative layers applied to injection-molded components. In such cases, to achieve the desired technical property profiles, it is often necessary to add a compatibility enhancer to the polymer blend composition. This enhancer reduces the interfacial tension between the polymers that make up the blend, thereby mitigating or, ideally, completely eliminating the aforementioned technical problems.

[0003] Furthermore, mixtures of polymers with different chemical compositions are suitable for the production of block copolymers consisting of blocks of the chemically different polymer species by reacting the two polymers with each other in the multiphase melt of the polymer mixture. Since such a reaction can naturally only occur at the phase interface of the different polymers in the melt, the reaction rate of such melt reactions depends on the size of the phase interface, i.e., on the phase dispersion or the domain size of the different polymers in the melt mixture. Thermodynamically stable, finely divided phase morphologies in the melt, which are necessary to achieve high conversion rates within technically feasible parameters, are therefore not recommended.Therefore, the need for meaningful reaction residence times often requires a reduction in the interfacial tension of the different polymers in the melt mixture, i.e., the use of compatibility enhancers as process aids.

[0004] Block copolymers consisting of blocks of polymers A and B are known to be suitable as compatibilizers in a polymer mixture of two chemically different polymers A and B. According to established knowledge, derived from experience with the emulsification of immiscible, low-viscosity liquids, bipolar AB block copolymer architectures generally appear particularly attractive to those skilled in the art with regard to achieving high efficacy for the intended purpose. However, such block copolymer structures are difficult to synthesize when block copolymers contain a polycondensation polymer as block A and a vinyl (co)polymer as block B. Graft copolymers consisting of blocks of a polycondensation polymer and a vinyl (co)polymer are fundamentally easier to synthesize.

[0005] US 4,959,411, for example, discloses a process for producing a copolymer by reacting a glycidyl methacrylate-grafted olefin polymer with a carboxy-functionalized polycarbonate in organic solution or in melt compounding, and the use of such a copolymer, which is evidently a graft copolymer, for compatibilizing polymer blends of polycarbonate and polyolefin with the aim of reducing their tendency to delaminate. This application is entirely silent on the effect of the spatial arrangement of the grafts on the graft backbone, the number of grafts, and the length of the grafts and the graft backbone on the effectiveness of the graft copolymers as compatibilizers in polymer blends.

[0006] The graft copolymers according to the prior art have an insufficient effect with regard to the reduction of the phase interface tension in blends or melt mixtures of the polymers A and B from which they are composed.

[0007] US 2006 / 063891 A1 discloses graft copolymers with a B-(A)n architecture, which are constructed from radical polymers as blocks A and B and consist of preferably n=2-8 graft strands of polymer A with a mean molecular weight Mn(A) of preferably 20,000 to 100,000 g / mol grafted onto the backbone of polymer B with a mean molecular weight Mn(B) of preferably >50,000 g / mol, wherein the relative block lengths are chosen such that n·Mn(A) / (n·Mn(A)+Mn(B)) is preferably in the range of 0.6 to 0.8. The application discloses that these graft copolymers are suitable for impact modification of transparent polymers. Their function as compatibility enhancers in blends of homopolymers A and B is not disclosed in this application.

[0008] CN 108586668 A discloses a polypropylene / polylactic acid ion-grafted copolymer with high toughness and a manufacturing process for it. The process provided by the invention is simple and low-cost and uses the interaction of anions and cations to graft the polylactic acid onto the main chain. No information is disclosed regarding its function as a compatibility enhancer.

[0009] US2012 / 071606 A1 discloses a process for forming polycarbonate graft copolymers. In particular, a polycarbonate polymer or copolymer containing allyl groups forms the backbone of the graft copolymer, and the side chains are bound to the copolymer via the allyl groups. The graft copolymers exhibit a combination of high transparency, good graft strength, good scratch resistance, and / or good anti-fog properties. This disclosure also provides no indication of an influence on phase compatibility.

[0010] US 488401 A discloses a resin composition for optics, comprising mainly a graft copolymer consisting of a styrene resin and an aromatic polycarbonate, each having a specific molecular weight at a specific molecular weight-to-weight ratio, wherein the composition has a microdispersed phase of no more than 0.5 µm. The resin composition is suitable for use in optics. No information is disclosed regarding a phase compatibility agent.

[0011] JP H09 143293 A discloses a film with a layer of a graft copolymer of a polyester and an acrylic polymer. The layer ensures good lubricity and printability. No information is disclosed regarding the effect of the graft copolymer as a phase compatibility mediator.

[0012] The present invention was based on the desire to provide special graft copolymers which, when used as additives or processing aids under comparable conditions (i.e., using the same molar concentration), exhibit improved effectiveness in reducing interfacial tension in polymer blends and / or reactive melt mixtures of polymers A and B that differ in their chemical composition. One of the polymers is a polycondensation polymer selected from the group consisting of polycarbonates, polyester carbonates, polyesters, polyamides, and mixtures thereof, and the other polymer is a polymer of one or more different vinyl monomers. The vinyl monomers are preferably selected from the group consisting of styrene, styrene derivatives, vinyl cyanides, acrylic esters, acrylic ester derivatives, olefins, maleimide, and maleimide derivatives.The ultimate goal is that these graft copolymers can contribute to an improved solution of at least one of the aforementioned technical problems, which are based on the insufficient compatibility of polymers A and B.

[0013] In this invention, the size is used as a measure of the reduction of interfacial tension. E = (1 - γ / γ 0 ) is used and referred to as phase compatibility mediator efficiency. γ 0 is the interfacial tension of the uncompatible polymer blend of homopolymers A and B, that is, the interfacial tension at the phase interface of such polymers in the absence of the graft copolymers, and γ The reduced interfacial tension value resulting from the addition of the graft copolymers. If the graft copolymer shows no effect as a compatibility enhancer, then... γ = γ 0 and therefore E= 0. In the other extreme case of best possible phase compatibility mediation, the interfacial tension at the phase interface of homopolymers A and B in the presence of the graft copolymers is reduced to the value γ = lowered to 0, meaning complete miscibility is achieved. In this case, the result is... E = 1. The value of the phase compatibility mediator efficiency EThis naturally depends on the concentration of the graft copolymer used. Within the scope of this invention, under the conditions applied in the underlying experiments, a minimum value of 30, preferably a minimum value of 35, more preferably 40, and particularly preferably 45 was considered desirable. Furthermore, it was desired that these graft copolymers exert their effective action with the lowest possible molecular weight of the graft copolymer used, since graft copolymers with excessively high molecular weights exhibit lower diffusion coefficients in polymer melts and are therefore, for kinetic reasons, more difficult (i.e., slower) to bring to the interface of the polymer components in polymer blends in order to effectively exert their desired effect.

[0014] The problem is solved by graft copolymers of the general structure B-(A) ns consisting of blocks of two polymers A and B that differ in their chemical composition, wherein one of the polymers, preferably polymer A, is a polycondensation polymer selected from the group consisting of polycarbonates, polyester carbonates, polyesters and polyamides, and the other polymer, preferably polymer B, is a polymer of at least one vinyl monomer, characterized in that (i) the number-averaged molecular weight of the block of polymer BM n (B) is at least 13 kg / mol, determined by a combination of gel permeation chromatography and NMR spectroscopy, (ii) the number of side chains in the graft copolymer ns, determined by NMR spectroscopy, is at least 3 and at most 15, (iii) the number-averaged molecular weight of the blocks of polymer AM n (A) is at least 1.5 kg / mol and at most 15 kg / mol, determined by a combination of gel permeation chromatography and NMR spectroscopy, and (iv) ns multiplied by M n (A) yields at least 13 kg / mol.

[0015] In the case of a mixture of graft copolymer molecules with different individual ns values, the feature "ns" according to the preferred ranges, embodiments and claims mentioned in this invention generally refers to the number-averaged arithmetic mean of the ns values ​​of the individual polymer molecules.

[0016] The value of ns is preferably at least 4, particularly preferably at least 5 and most preferably at least 6.

[0017] M n (A) is preferably at least 3.0 kg / mol, particularly preferably at least 4.5 kg / mol and most preferably at least 5.3 kg / mol.

[0018] M n (B) is preferably at least 20 kg / mol, particularly preferably at least 23 kg / mol and most preferably at least 30 kg / mol.

[0019] The value of nsx M n (A) is preferably at least 20 kg / mol, particularly preferably at least 30 kg / mol and most preferably at least 35 kg / mol.

[0020] The value of ns is preferably at most 12, more preferably at most 10, and most preferably at most 8.

[0021] The value of M n ( B) is preferably at most 200 kg / mol, more preferably at most 100 kg / mol, and particularly preferably at most 50 kg / mol.

[0022] The value of M n (A) is preferably at most 12 kg / mol, preferably at most 9 kg / mol, particularly preferably at most 8 kg / mol.

[0023] The value of ns multiplied by M n (A) is preferably at most 120 kg / mol, more preferably at 80 kg / mol, and particularly preferably at 50 kg / mol.

[0024] It is preferably that M n (A)×ns / [M n (B)+ M n (A)×ns ] is in the range of 0.25 to 0.75, more preferably in the range of 0.40 to 0.70 and particularly preferably in the range of 0.40 to 0.60.

[0025] The upper and lower bounds of ns , M n (A), M n (B) and nsx M n (A) as well as the ranges of M n (A)×ns / [M n (B)+ M n (A)×ns ] can be combined arbitrarily.

[0026] Graft copolymers are particularly preferred, characterized by the combination of the following features: (i) M n (B) at least 23 kg / mol, (ii) ns at least 5, (iii) M n (A) at least 3.0 kg / mol and (iv) ns multiplied by M n (A) at least 13 kg / mol.

[0027] Particularly preferred are graft copolymers characterized by the combination of the following features: (i) M n (B) at least 23 kg / mol, (ii) ns at least 6, (iii) M n (A) at least 4.5 kg / mol and (iv) ns multiplied by M n (A) at least 13 kg / mol.

[0028] The most preferred graft copolymers are characterized by the combination of the following features: (i) M n (B) at least 23 kg / mol, (ii) ns at least 6, (iii) M n (A) at least 4.5 kg / mol, (iv) ns multiplied by M n (A) at least 13 kg / mol and (v) M n (A)×ns / [M n (B)+ M n (A)×ns ] in the range of 0.40 to 0.70.

[0029] The graft copolymers according to the invention can further differ with respect to their architecture, i.e., the spatial distribution of the grafts on the graft copolymer backbone. The grafts can be grafted onto the graft copolymer backbone in a statistically distributed manner ("statistically grafted"). It is also possible that (i) the grafts are arranged uniformly and equidistantly on the graft copolymer backbone ("uniformly equidistantly grafted"). Furthermore, (ii) the grafts can be arranged entirely at one end of the graft copolymer backbone ("single end grafted"), (iii) the grafts can be arranged at each of the two ends of the graft copolymer backbone ("double end grafted"), or (iv) the grafts can be arranged in the middle of the graft copolymer backbone ("centrally grafted"). Architectures (i) to (iv) are described in Figure 1 schematically represented.

[0030] Preferably, the graft copolymer according to the invention is grafted centrally or double end-grafted; more preferably, it is grafted centrally.

[0031] Architectures (ii), (iii) and (iv) comprise a graft copolymer backbone containing sections with graft stems and sections without graft stems. Preferred are graft copolymers in which the sections of the graft copolymer backbone with graft stems constitute a total mass fraction of at most 50 wt.%, more preferably at most 40 wt.%, and most preferably at most 30 wt.% of the graft copolymer backbone.

[0032] Within the scope of the present invention, the polymer made from the vinyl monomers is also referred to as vinyl (co)polymer.

[0033] Within the scope of the present invention, block B is also referred to as the graft copolymer backbone, graft copolymer backbone, or backbone. Blocks A are referred to as side chains or graft stems.

[0034] Preferably, the at least one vinyl monomer is selected from the group consisting of styrene, styrene derivatives, vinyl cyanides, acrylic acid esters, acrylic acid ester derivatives, olefins, maleic imide and maleic imide derivatives.

[0035] Preferably, the polymer blocks A and B exhibit similar polarities and, more preferably, similar chemical structures to the polymers that constitute the polymer blend or polymer melt mixture for which a reduction in interfacial tension is desired. That is, preferably, the polymer combination of blocks A and B exhibits a similar Flory-Huggins parameter to the combination of polymers that constitute the polymer blend or polymer melt mixture for which a reduction in interfacial tension is desired.

[0036] It is further preferred that the blocks consist of the same polymers A and B that are also contained in the polymer blend or polymer melt mixture, for which a reduction of the interfacial tension is desired. The expression "of the same polymers A and B" refers to the chemical structure, but not necessarily to the molecular weight. Polycondensation polymer

[0037] One of the polymers from which the graft copolymer according to the invention is constructed, preferably polymer A, is a polycondensation polymer selected from the group consisting of polycarbonates, polyester carbonates, polyesters, and polyamides. Mixtures of different polycondensation polymers with similar polarity and chemical structure can also be used, for example, mixtures of structurally different, preferably aromatic, polycarbonates, preferably aromatic polyester carbonates, or preferably aromatic polyesters, preferably mixtures of structurally different, preferably aromatic, polycarbonates, or mixtures of structurally different, preferably aromatic, polyester carbonates, or mixtures of structurally different, preferably aromatic, polyesters, particularly preferably mixtures of structurally different, preferably aromatic, polycarbonates.

[0038] Suitable polycarbonates and / or polyester carbonates according to component A are known from the literature or can be produced using methods known from the literature (for the production of polycarbonates, see, for example, Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, 1964, as well as DE-AS 1 495 626, DE-A 2 232 877, DE-A 2 703 376, DE-A 2 714 544, DE-A 3 000 610, DE-A 3 832 396; for the production of polyester carbonates, see, for example, DE-A 3 007 934).

[0039] The polycarbonates are produced, for example, by reacting at least one aliphatic and / or aromatic diol (diphenol) with carbonic acid halides, preferably phosgene, and / or with, preferably, aromatic dicarboxylic acid dihalides, preferably benzene dicarboxylic acid dihalides, using an interfacial process, optionally with the use of chain terminators, such as monophenols, and optionally with the use of trifunctional or more than trifunctional branchers, such as triphenols or tetraphenols. Mixtures of aliphatic and aromatic diols can also be used. Likewise, production via a melt polymerization process by reacting aliphatic and / or aromatic diols (diphenols) with, for example, diphenyl carbonate is possible.

[0040] Diphenols for the production of aromatic polycarbonates and / or aromatic polyester carbonates are preferably those of formula (1) where A a single bond, C 1 to C 5 alkylenes, C 2 to C 5 alkylidenes, C 5 to C 6 cycloalkylidenes, -O-, -SO-, -CO-, -S-, -SO 2-, C 6 to C 12 arylenes, to which further aromatic rings, optionally containing heteroatoms, may be fused, or a residue of formula (2) or (3) B each C 1 to C 12 -alkyl, preferably methyl, halogen, preferably chlorine and / or bromine x each independently of each other 0, 1 or 2, p 1 or 0, and R 5< and R 6< for each X 1< individually selectable, independently of each other hydrogen or C 1 to C 6 -alkyl, preferably hydrogen, methyl or ethyl, X1 carbon and m an integer from 4 to 7, preferably 4 or 5, with the proviso that at least one atom X 1< , R 5< and R 6< are simultaneously alkyl.

[0041] Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-(hydroxyphenyl)-C 1 -C 5 -alkanes, bis-(hydroxyphenyl)-C 5 -C 6 -cycloalkanes, bis-(hydroxyphenyl) ethers, bis-(hydroxyphenyl) sulfoxides, bis-(hydroxyphenyl) ketones, bis-(hydroxyphenyl) sulfones and α,α-bis-(hydroxyphenyl)-diisopropyl benzenes as well as their nuclear-brominated and / or nuclear-chlorinated derivatives.

[0042] Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, bisphenol A, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, and their di- and tetrabrominated or chlorinated derivatives, such as 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)propane, or 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)propane. 2,2-bis-(4-hydroxyphenyl)propane (bisphenol A) is particularly preferred.

[0043] The diphenols can be used individually or in any mixture. The diphenols are known from the literature or can be obtained through methods known from the literature.

[0044] Suitable aliphatic diols are selected from the group consisting of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2-bis(4-hydroxycyclohexyl)propane, tetrahydro-2,5-furandimethanol, 2-butyl-2-ethyl-1,3-propanediol, 2-(2-hydroxyethoxy)ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dimethylpropane-1,3-diol, and cyclobutane-1,1-diyldimethanol. 8-(Hydroxymethyl)-3-tricyclo[5.2.1.02,6]decanyl]methanol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, isosorbide and any mixtures thereof.

[0045] Suitable chain termination compounds for the production of thermoplastic aromatic polycarbonates include, for example, phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, but also long-chain alkylphenols, such as 4-[2-(2,4,4-trimethylpentyl)]-phenol, 4-(1,3-tetramethylbutyl)-phenol according to DE-A 2 842 005 or monoalkylphenol or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituents, such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert-octylphenol, p-dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators to be used is generally between 0.5 mol% and 10 mol%, based on the total moles of the diphenols used.

[0046] The thermoplastic aromatic polycarbonates can be branched in a known manner by the incorporation of trifunctional or more than trifunctional compounds, for example, those with three or more phenolic groups. However, linear polycarbonates, more preferably based on bisphenol A, are preferred.

[0047] Both homopolycarbonates and copolycarbonates are suitable. For the production of copolycarbonates according to the invention, component A, 1 to 25 wt.%, preferably 2.5 to 25 wt.%, based on the total amount of diols to be used, of polydiorganosiloxanes with hydroxyaryloxy end groups can also be employed. These are known (US 3,419,634) and can be produced according to methods known from the literature. The production of the polydiorganosiloxane-containing copolycarbonates is described, for example, in DE-A 3 334 782 and WO 2015 / 052106 A2.

[0048] Copolycarbonates produced using diphenols of the following structures are also preferred: where R1 represents hydrogen, C1 to C4 alkyl, preferably hydrogen or methyl, and particularly preferably hydrogen; R2 independently represents aryl or alkyl, preferably methyl; X represents a single bond, -SO2-, -CO-, -O-, -S-, C1 to C6 alkylene, C2 to C5 alkylidene, or C6 to C12 arylene, which may optionally be condensed with aromatic rings containing further heteroatoms; X preferably represents a single bond, C1 to C5 alkylene, C2 to C5 alkylidene, C5 to C12 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-; X particularly preferably represents a single bond, isopropylidene, C5 to C12 cycloalkylidene, or oxygen, and most preferably isopropylidene; n represents an average number of 10 to 400, preferably 10 and 100, particularly preferably 15 to 50 means and m represents an average number of 1 to 10, preferably 1 to 6 and particularly preferably 1,5 to 5 stands.

[0049] Aromatic dicarboxylic acid dihalides for the production of aromatic polyester carbonates are preferably the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4'-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid. Mixtures of the diacid dichlorides of isophthalic acid and terephthalic acid in a ratio between 1:20 and 20:1 are particularly preferred.

[0050] In the production of polyester carbonates, a carbonic acid halide, preferably phosgene, is additionally used as a bifunctional acid derivative.

[0051] In addition to the monophenols already mentioned, other suitable chain terminators for the production of aromatic polyester carbonates include their chlorocarbonate esters, the acid chlorides of aromatic monocarboxylic acids, which may optionally be substituted by C 1 to C 22 alkyl groups or by halogen atoms, and aliphatic C 2 to C 22 monocarboxylic acid chlorides.

[0052] The amount of chain terminators is 0.1 to 10 mol% in each case, based on moles of diphenol in the case of phenolic chain terminators and on moles of dicarboxylic acid dichloride in the case of monocarboxylic acid chloride chain terminators.

[0053] In the production of aromatic polyester carbonates, one or more aromatic hydroxycarboxylic acids can be used in addition.

[0054] The aromatic polyester carbonates can be either linear or branched in a known manner (see DE-A 2 940 024 and DE-A 3 007 934), but linear polyester carbonates are preferred.

[0055] Branching agents can include, for example, tri- or multi-functional carboxylic acid chlorides such as trimesic acid trichloride, cyanuric acid trichloride, 3,3'-,4,4'-benzophenone tetracarboxylic acid tetrachloride, 1,4,5,8-napthalin tetracarboxylic acid tetrachloride, or pyromellitic acid tetrachloride, or tri- or multi-functional phenols such as phloroglucinol, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)hept-2-ene, 4,6-dimethyl-2,4-6-tri-(4-hydroxyphenyl)heptane, 1,3,5-tri-(4-hydroxyphenyl)benzene, 1,1,1-tri-(4-hydroxyphenyl)ethane, tri-(4-hydroxyphenyl)phenylmethane, 2,2-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane, 2,4-Bis(4-hydroxyphenyl-isopropyl)-phenol, Tetra-(4-hydroxyphenyl)-methane, 2,6-Bis(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol, 2-(4-Hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane, Tetra-(4-[4-hydroxyphenyl-isopropyl]-phenoxy)-methane, 1,4-Bis[4,4'-dihydroxytri-phenyl]-methyl]-benzene, in amounts of 0.01 to 1.0 mol% based on the diphenols used.Phenolic branching agents can be introduced with the diphenols. Acid chloride branching agents can be introduced together with the acid dichlorides.

[0056] In thermoplastic aromatic polyester carbonates, the proportion of carbonate structural units can vary as desired. Preferably, the proportion of carbonate groups is up to 99.9 mol%, particularly up to 80 mol%, and most preferably up to 50 mol%, based on the sum of ester and carbonate groups. Both the ester and carbonate components of the aromatic polyester carbonates can be present in the form of blocks or statistically distributed within the polycondensate.

[0057] In a preferred embodiment, the polyesters in question are aromatic; more preferably, they are polyalkylene terephthalates. In a particularly preferred embodiment, these are reaction products of aromatic dicarboxylic acids or their reactive derivatives, such as dimethyl esters or anhydrides, and aliphatic, cycloaliphatic, or araliphatic diols, as well as mixtures of these reaction products.

[0058] Particularly preferred aromatic polyalkylene terephthalates contain at least 80 wt.%, preferably at least 90 wt.%, based on the dicarboxylic acid component terephthalic acid residues and at least 80 wt.%, preferably at least 90 wt.%, based on the diol component ethylene glycol and / or butanediol-1,4 residues.

[0059] The preferred aromatic polyalkylene terephthalates may contain, in addition to terephthalic acid residues up to 20 mol%, preferably up to 10 mol%, residues of other aromatic or cycloaliphatic dicarboxylic acids with 8 to 14 C atoms or aliphatic dicarboxylic acids with 4 to 12 C atoms, such as residues of phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanedioacetic acid.

[0060] The preferred aromatic polyalkylene terephthalates may contain, in addition to ethylene glycol or butanediol-1,4 residues up to 20 mol%, preferably up to 10 mol%, other aliphatic diols with 3 to 12 carbon atoms or cycloaliphatic diols with 6 to 21 carbon atoms, e.g., residues of propanediol-1,3, 2-ethylpropanediol-1,3, neopentyl glycol, pentanediol-1,5, hexanediol-1,6, cyclohexane-dimethanol-1,4, 3-ethylpentanediol-2,4, 2-methylpentanediol-2,4, 2,2,4-trimethylpentanediol-1,3, 2-ethylhexanediol-1,3, 2,2-diethylpropanediol-1,3, hexanediol-2,5, 1,4-di-(β-hydroxyethoxy)benzene. 2,2-bis-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis-(4-β-hydroxyethoxy-phenyl)-propane and 2,2-bis-(4-hydroxypropoxyphenyl)-propane (DE-A 2 407 674, 2 407 776, 2 715 932).

[0061] Aromatic polyalkylene terephthalates prepared solely from terephthalic acid and its reactive derivatives (e.g. its dialkyl esters) and ethylene glycol and / or 1,4-butanediol, and mixtures of these polyalkylene terephthalates are particularly preferred.

[0062] Preferred mixtures of aromatic polyalkylene terephthalates contain 1 to 50 wt.%, preferably 1 to 30 wt.%, polyethylene terephthalate and 50 to 99 wt.%, preferably 70 to 99 wt.%, polybutylene terephthalate.

[0063] Aromatic polyalkylene terephthalates can be produced using known methods (see, for example, Kunststoff-Handbuch, Volume VIII, p. 695 ff., Carl-Hanser-Verlag, Munich 1973).

[0064] In one embodiment of the present invention, amorphous and / or semi-crystalline polyamides are used as the polycondensation polymer. Suitable polyamides are aliphatic polyamides, for example PA-6, PA-11, PA-12, PA-4.6, PA-4.8, PA-4.10, PA-4.12, PA-6.6, PA-6.9, PA-6.10, PA-6.12, PA-10.10, PA-12.12, PA-6 / 6.6-copolyamide, PA-6 / 12-copolyamide, PA-6 / 11-copolyamide, PA-6.6 / 11-copolyamide, PA-6.6 / 12-copolyamide, PA-6 / 6.10-copolyamide, PA-6.6 / 6.10-copolyamide, PA-4.6 / 6-copolyamide, PA-6 / 6.6 / 6.10-terpolyamide, and copolyamides made from 1,4-cyclohexanedicarboxylic acid and 2,2,4- and 2,4,4-Trimethylhexamethylenediamine, aromatic polyamides, for example PA-6,1, PA-6,1 / 6,6-copolyamide, PA-6,T, PA-6,T / 6-copolyamide, PA-6,T / 6,6-copolyamide, PA-6,1 / 6,T-copolyamide, PA-6,6 / 6,T / 6,1-copolyamide, PA-6,T / 2-MPMDT-copolyamide (2-MPMDT = 2-methylpentamethylenediamine), PA-9,T, copolyamide of terephthalic acid, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, copolyamide of isophthalic acid, laurinlactam and 3,5-dimethyl-4,4-Diaminodicyclohexylmethane, copolyamide of isophthalic acid, azelaic acid and / or sebacic acid and 4,4-diaminodicyclohexylmethane, copolyamide of caprolactam, isophthalic acid and / or terephthalic acid and 4,4-diaminodicyclohexylmethane, copolyamide of caprolactam, isophthalic acid and / or terephthalic acid and isophorone diamine, copolyamide of isophthalic acid and / or terephthalic acid and / or other aromatic or aliphatic dicarboxylic acids, optionally alkyl-substituted hexamethylenediamine and alkyl-substituted 4,4-diaminodicyclohexylamine or their copolyamides, as well as mixtures of the aforementioned polyamides.

[0065] Linear polycarbonate based exclusively on bisphenol A is preferably used as the polycondensation polymer. Vinyl(co)polymer

[0066] The vinyl(co)polymers according to the invention are a polymer consisting of one or more vinyl monomers, preferably selected from styrene, styrene derivatives, acrylonitrile, acrylic acid esters, acrylic acid ester derivatives, olefins, maleic imide and maleic imide derivatives.

[0067] Within the scope of the present invention, vinyl (co)polymers are also understood to be polymers consisting of one or more vinyl monomers that additionally contain grafting-active units as comonomers or end groups incorporated into the polymer chain and / or grafted onto the polymer chain. The amount of these grafting-active units determines the feature of the invention ns.

[0068] Suitable styrene derivatives include, for example, α-methylstyrene and core-substituted vinyl aromatics such as p-methylstyrene and p-chlorostyrene.

[0069] Examples of acrylic acid esters and acrylic acid ester derivatives include (meth)acrylic acid (C 1 -C 8 ) alkyl esters such as methyl methacrylate, n-butyl acrylate and tert-butyl acrylate and glycidyl methacrylate.

[0070] Examples of vinyl cyanides include acrylonitrile and methacrylonitrile.

[0071] Depending on which of the manufacturing processes mentioned below is used for the graft copolymers according to the invention, it may be necessary to use at least a portion of a vinyl monomer containing reactive groups for the coupling reaction, such as hydroxyl, carboxyl, amino, or double bond-containing groups like vinyl, allyl, or acryloyl, carbonyl, nitrile, ester, or epoxy groups. Epoxy groups are preferred, and glycidyl methacrylate is particularly preferred as at least one of the vinyl monomers. The glycidyl methacrylate can be polymerized into the main chain of the vinyl (co)polymer or grafted onto the main chain of the vinyl (co)polymer as a side group. Preferably, the glycidyl methacrylate is polymerized into the main chain of the vinyl (co)polymer.

[0072] Other suitable vinyl(co)polymers are (co)polymers made of B.1 50 to 99 wt.%, preferably 65 to 85 wt.%, particularly preferably 70 to 80 wt.% based on the (co)polymer B of at least one monomer selected from the group consisting of vinyl aromatics, core-substituted vinyl aromatics and (meth)acrylic acid (C1-C8) alkyl esters and B.2 1 to 50 wt.%, preferably 15 to 35 wt.%, particularly preferably 20 to 30 wt.% based on the (co)polymer B of at least one monomer selected from the group consisting of vinyl cyanides and (meth)acrylic acid (C1-C8) alkyl esters.

[0073] Vinyl(co)polymers are known and can be produced, for example, by radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization.

[0074] Polyolefins are also produced by chain polymerization, for example, by radical or anionic polymerization. Alkenes are used as monomers in these reactions. An alternative name for alkenes is olefins. The monomers can be polymerized individually or as a mixture of different monomers. Preferred monomers are ethylene, propylene, 1-butene, isobutene, 1-pentene, 1-heptene, 1-octene, and 4-methyl-1-pentene.

[0075] The polyolefins can contain up to 50 wt.%, more preferably up to 30 wt.%, further vinylic comonomers, for example and preferably methyl acrylate, ethyl acrylate, butyl acrylate, glycidyl methacrylate and methyl methacrylate.

[0076] Polyolefins can be amorphous or semi-crystalline. They can be linear or branched. The production of polyolefins has long been known to those skilled in the art.

[0077] The polymerization can be carried out, for example, at pressures of 1 to 3000 bar and temperatures between 20°C and 300°C, optionally using a catalyst system. Suitable catalysts include mixtures of titanium and aluminum compounds as well as metallocenes.

[0078] By changing the polymerization conditions and the catalyst system, the number of branches, the crystallinity, and the density of the polyolefins can be varied over a wide range. These measures are also familiar to those skilled in the art. Production of the graft copolymers according to the invention

[0079] Graft copolymerization is a technique for producing polymers whose main chain serves as the starting point for further chains of a different monomer type. This results in a copolymer B-(A) ns, to whose main chain B several chains A, composed of another monomer type, are attached in a comb-like fashion, and ns indicates the number of these chains. Within the scope of this invention, the main chain A is also referred to as the backbone, and the chains B as side chains or graft branches.

[0080] With regard to the present invention, it is irrelevant by which method the graft copolymer structures according to the invention are produced; that is to say, in principle all graft copolymerization processes known to the skilled person are suitable for the production of such graft copolymers according to the invention, provided that the claimed product features are realized with them.

[0081] The following three graft copolymerization processes, which are fundamentally suitable for the production of the graft copolymers according to the invention, are known to those skilled in the art, for example: "Grafting to" process:

[0082] A polymer is exposed to high-energy electromagnetic radiation (e.g., gamma radiation), which generates free radicals along its backbone. These free radicals then serve as the starting point for further radical polymerization, leading to the formation of a second polymer. Alternatively, radical initiators can be used instead of high-energy electromagnetic radiation to generate the free radicals along the backbone of the first polymer. Such radical initiators decompose at the elevated temperature of the grafting reaction or, alternatively, under the influence of higher-energy electromagnetic radiation (e.g.,UV radiation) generates radicals, which in turn can produce free radicals by abstracting, for example, hydrogen atoms from the backbone of the first polymer along its main chain or at side groups of the polymer. These free radicals then form the starting point for further radical polymerization, leading to the expansion of the second polymer. Preferred radical-forming compounds are azo compounds such as azoisobutyronitrile (AIBN) and organic or inorganic peroxides such as dibenzoyl peroxide (DBPO) or alkali peroxodisulfates. Such graft polymerization processes can, in principle, be carried out in a solution, emulsion, or suspension of the first polymer, in the melt of the first polymer, or in the solid state of the first polymer. In the latter case, the monomers from which the second polymer, forming the grafts, is built up are swollen into the solid of the first polymer and then polymerized.

[0083] In an alternative process, an existing polymer and the monomer to be added are dissolved in a nonpolar solvent (e.g., dichloromethane) and treated with a Lewis acid (coining agent). The Lewis acid then removes electrons from the polymer at several sites. The resulting positively charged sites then serve as the starting point for a cationic polymerization with the monomer, which forms the grafts. "Grafting-from" process:

[0084] In this process, reactive functional groups, such as those containing hydroxyl, carboxyl, amino, or double bonds (e.g., vinyl, allyl, or acryloyl), carbonyl, nitrile, ester, or epoxy groups, are incorporated into the backbone of the first polymer along its main chain or at any side chains. This can be achieved through copolymerization with monomers containing such functional groups or through subsequent chemical treatment of the backbone polymer. A graft copolymerization can then attack these reactive functional groups in the backbone polymer, building up the grafts from monomeric building blocks. Depending on the functional group, different polymerization processes are suitable for graft formation, such as polycondensation, polyaddition, or radical, anionic, or cationic polymerization. Grafting methods via macromonomers:

[0085] In this process, in a first step, polymer blocks equipped with reactive groups of both the graft backbone and the side chains are produced via polymerization processes that are generally known to those skilled in the art, for example polycondensation, polyaddition or radical, anionic or cationic polymerization, and in a second step these two reactive polymers (macromonomers) are chemically coupled together to form the graft copolymer.

[0086] The chemical coupling reaction can take place either in a solution containing a solvent suitable for both polymers to be coupled, or in the melt mixture of the two polymers. The melt reaction is preferred for environmental reasons, as it does not require a solvent. Such melt reactions can be carried out, for example, in stirred tank reactors, continuous tubular reactors equipped with mixing devices, or preferably in commercially available compounding units such as twin-shaft extruders, planetary roller extruders, or internal kneaders, and also preferably in film extruders, at temperatures above the melting temperatures of both polymers to be coupled.

[0087] Suitable reactive groups for the coupling reaction in this case include, for example, groups containing hydroxyl, carboxyl, amino, or double bonds, such as vinyl, allyl, or acryloyl, carbonyl, nitrile, ester, or epoxy groups. The functional groups in the two types of polymer blocks that form the backbone or grafts in the graft copolymer must be paired to allow a coupling reaction, preferably a condensation or addition reaction, and particularly preferably an addition reaction. Preferred combinations include, for example, hydroxyl, amino, or carboxyl groups functionalizing one polymer and epoxy groups functionalizing the second polymer. More preferred combinations include amino or carboxyl groups functionalizing one polymer and epoxy groups functionalizing the second polymer.In the case that the polycondensation polymer is a polycarbonate, a polyester, or a polyester carbonate, the combination of carboxyl groups as a functionalization of one polymer and epoxy groups as a functionalization of the other polymer is particularly preferred. It is further preferred that the polycarbonate, the polyester, or the polyester carbonate is functionalized with carboxyl groups and the vinyl (co)polymer with epoxy groups.

[0088] The functional groups in the polymer forming the grafts are preferably introduced at the ends. Polymer blocks containing only a small proportion of multiply functionalized polymer molecules, i.e., polymer molecules with more than one reactive functional group, are preferably used as the macromonomer for graft formation. Polymers containing a maximum of 1.5, more preferably a maximum of 1.3, and most preferably a maximum of 1.1 reactive functional groups per polymer molecule are particularly preferred for graft formation. Most preferably, polymers containing only one terminal functional group are used for graft formation. This minimizes the number of branching structures in the graft copolymer or prevents the formation of such undesirable structures.

[0089] The preparation for the formation of grafts of particularly preferred carboxy-terminated polycarbonates or polyester carbonates is carried out, for example, according to the description in US 4,959,411. Carboxy-functionalized phenols or, preferably, derivatives, in particular esters of carboxy-functionalized phenols, especially tert-butyl esters of carboxy-functionalized phenols, and most preferably tert-butyl 4-hydroxybenzoate, are used as chain terminations in the polycondensation reaction that forms the polycarbonate or polyester carbonate, preferably carried out in a phase-interface phosgenation of bisphenols.In the preferred case of using tert-butyl ester carboxy-functionalized phenols as end-group forming chain terminators, the release of the terminal carboxy groups takes place in a subsequent thermal pyrolysis step, in which isobutylene is cleaved off at temperatures above 200°C and removed from the reaction mixture under reduced pressure to shift the chemical equilibrium.

[0090] While the polymers disclosed in US 4,959,411 exclusively use carboxy-functionalized phenols or, preferably, derivatives, in particular esters of carboxy-functionalized phenols, as chain terminators, thus producing doubly end-functionalized polycarbonates, it is recommended to use mixtures of such carboxy-functionalized phenols or, preferably, derivatives, in particular esters of carboxy-functionalized phenols, with non-reactively functionalized phenols, for example, tert-butylphenol or phenol, as chain terminators for the production of the polymer blocks particularly suitable for forming the grafts within the scope of this invention. This allows the average carboxy functionality of the resulting polycarbonate blocks to be reduced to the desired level described above.Preferably, these chain-terminating mixtures contain non-reactive phenols in a molar proportion of at least 50 mol%, more preferably at least 65 mol%, particularly preferably at least 70 mol%, and particularly preferably at least 75 mol%.

[0091] The production of graft copolymers according to the invention from these carboxy- or carboxy derivative-functionalized polycarbonates produced in this manner can be carried out by coupling with the epoxy functionalities of glycidyl methacrylate-grafted polymers or with the epoxy functionalities of vinyl (co)polymers containing structural units derived from glycidyl methacrylate, according to the process also described in US 4,959,411. When using such glycidyl methacrylate-grafted polymers or vinyl (co)polymers containing structural units derived from glycidyl methacrylate as the graft backbone in the production of the graft copolymer, the number of grafts ns in the resulting graft copolymer can be precisely controlled by appropriately selecting the ratio of the molar amounts of glycidyl methacrylate and non-reactive vinyl monomers. The production of such glycidyl methacrylate-modified polymers is generally known to those skilled in the art.Corresponding commercial products are available under brand names such as Fine-Blend™< SAG and Fine-Blend™< SOG (both Fine-blend Polymer Shanghai Co., LTD) or Lotader™< AX (Arkema).

[0092] The production of the particularly preferred double terminal and mid-grafted graft copolymers can, in principle, be carried out according to the same process as previously described by chemical coupling of macromonomers, wherein in this particular embodiment of the invention block copolymers are used as the graft backbone, preferably block copolymers consisting of blocks of vinyl(co)polymers.

[0093] In the case of the production of a double terminal grafted graft copolymer, a block copolymer containing at least three blocks is used as the graft backbone, wherein only the two outer blocks of the block copolymer are equipped with reactive functional groups according to the aforementioned preferred regions, and in the middle of the block copolymer, which is used as the graft backbone, there is a section consisting of at least one block that does not contain any functional groups suitable for coupling with the graft blocks.

[0094] In the case of the production of a medium-grafted graft copolymer, a block copolymer containing at least three blocks is used as the graft backbone, wherein the two outer sections of the block copolymer each consist of at least one block that does not contain any functional groups suitable for coupling with the graft blocks, and in the middle section of the block copolymer a block is used which is equipped with reactive functional groups according to the aforementioned preferred areas.

[0095] The blocks equipped with reactive functional groups are preferably copolymers, and more preferably statistical copolymers of glycidyl methacrylate and at least one other vinyl monomer.

[0096] The production of block copolymers suitable as graft backbones for the manufacture of intermediately and / or doubly terminally grafted graft copolymers is generally known to those skilled in the art. Preferably, controlled polymerization processes (often also referred to as "living" polymerization) are used to produce such structurally defined block copolymers from blocks of different chemical compositions. Suitable processes include living anionic polymerization, living cationic polymerization, living ring-opening metathesis polymerization, living radical polymerization, and living polycondensation.Preferably, a living radical polymerization process is used, particularly preferably atom transfer radical polymerization (ATRP) or reversible addition fragmentation chain transfer polymerization (RAFT).

[0097] Controlled ("living") polymerization refers to polymerizations in which no chain termination or chain transfer reactions occur, and the rate of chain initiation is much higher than the rate of chain elongation. This allows for the control of molar masses with narrow distributions and the synthesis of chemically defined polymer structures, such as specific block copolymers with well-defined sequence lengths and block compositions. These block copolymers are built up in several steps, using different monomers or monomer mixtures in each step.

[0098] A block copolymer suitable for producing a grafted graft copolymer as a graft backbone, consisting of structural units derived from, for example, styrene, can thus be produced, for example, by one of the aforementioned living polymerization processes, such as ATRP, by first polymerizing only styrene to the desired chain length in a first step, then polymerizing a mixture of styrene and glycidyl methacrylate onto the polymer from step 1 in a second step, and finally polymerizing pure styrene onto the polymer from step 2 in a third step, whereby the distance between two graft stems in the grafted graft copolymer can be defined by the molar ratio of styrene and glycidyl methacrylate in step 2.

[0099] A block copolymer suitable for the production of a doubly terminally grafted graft copolymer as a graft backbone, consisting of structural units derived from, for example, styrene, can be produced in an analogous manner, for example, by one of the aforementioned living polymerization processes, such as ATRP, by first polymerizing a mixture of styrene and glycidyl methacrylate to the desired chain length in a first step, then polymerizing a block of pure styrene onto the polymer from step 1 in a second step, and finally polymerizing another mixture of styrene and glycidyl methacrylate onto the polymer from step 2 in a third step, whereby the distance between two graft strands in the two terminal blocks can be defined by the molar ratio of styrene and glycidyl methacrylate in steps 1 and 3.The ratio of styrene to glycidyl methacrylate in the two terminal blocks can be chosen to be the same or different, and the block lengths of the three blocks can also be designed independently of each other. Experimental determination of the structural features of the graft copolymers according to the invention

[0100] The structural features of the graft copolymers according to the invention can be determined analytically in multi-step processes.

[0101] The structural features of graft copolymers according to the invention, in which the graft backbone is a vinyl(co)polymer and the side chains are a polycondensation polymer, can be determined, for example, by an analytical method consisting of the following steps: 1.) Determination of the chemical composition, i.e., the type and monomer composition of blocks A and B of the graft copolymer, by nuclear magnetic resonance spectroscopy (NMR), in particular < ¹H NMR and / or < ¹³C NMR. The solvent is selected accordingly for the graft copolymer. Especially with graft copolymers consisting of blocks A and B with strongly different polarities, for example, B = polyolefin and A = aromatic polycarbonate, it is often necessary to perform the NMR spectroscopy at high temperatures >60°C to achieve complete dissolution of the graft copolymer. Polychlorinated solvents such as deuterated dichloroethane, deuterated tetrachloroethane, tetrachloromethane, or deuterated di-, tri-, tetrachlorobenzene are particularly suitable for this purpose. 2.) Determination of the weight fraction xA of blocks of polymer A in the graft copolymer from the NMR spectroscopic data obtained in step 1. 3.) Determination of the number ns of grafts by NMR spectroscopy, in particular 1< H NMR and / or 13< C NMR, from the intensity of NMR signals that can be attributed either to the carbon atoms directly involved in or adjacent to the covalent graft bond, or to the protons adjacent to the covalent graft bond. 4.) Determination of the molecular weight distribution of the graft copolymer by gel permeation chromatography (GPC) and determination of the number-averaged molecular weight M n from it, wherein the GPC data determined on the graft copolymer are calibrated against both polymers A and B as standards with determination of the values ​​M n (A) and M n (B), where M n,A and M n,B represent the molecular weights calibrated against standards of polymer A and B respectively, and from this the value M n of the graft copolymer is calculated according to the formula M n = x A · M n,A +(1 - x A ) · M n,B .In GPC, especially with graft copolymers consisting of blocks A and B with strongly differing polarities, for example, B = polyolefin and A = aromatic polycarbonate, it is often necessary to perform the analysis at high temperatures (>60°C) to achieve complete dissolution of the graft copolymer. The same solvents used for NMR spectroscopy in step 1 are suitable and preferably employed for this purpose, although the use of deuterated solvents is not required for GPC. 5.) Basic saponification or acid- or basic-catalyzed complete hydrolysis of the polycondensation blocks (i.e., complete breakdown of the polycondensation polymer components into the monomeric building blocks from which they are composed) and separation of the remaining intact vinyl(co)polymer block (graft backbone) by precipitation, followed by washing and drying.Preferably, the polycondensation polymer fractions are cleaved back into the monomeric building blocks by basic saponification in, for example, an ethanolic potassium hydroxide solution at elevated temperature, preferably under reflux. 6.) Determination of the molecular weight distribution of the vinyl(co)polymer block (graft backbone) separated in step 5 by gel permeation chromatography (GPC) and determination of the number-averaged molecular weight Mn(B) from this, wherein the GPC measurement is calibrated against the respective vinyl(co)polymer in the graft copolymer as a standard. The solvent is selected for the respective vinyl(co)polymer. For example, dichloromethane or chloroform is preferably suitable as a solvent for polystyrene, polymethyl methacrylate, or styrene-acrylonitrile copolymers (SAN), which each contain glycidyl methacrylate as the graft-active site as a co- or termonomer unit.In these cases, GPC at room temperature is generally possible and preferred. However, with polyolefins, especially semi-crystalline polyolefins and polyolefins with higher molecular weight, it is often necessary to carry out GPC at high temperatures (>60°C) to achieve complete dissolution of the graft copolymer. For this purpose, polychlorinated solvents such as dichloroethane, tetrachloroethane, methanetetrachloride, or di-, tri-, tetrachlorobenzene, especially ortho-dichlorobenzene, are particularly suitable. 7.) Calculation of the value of ns · M n (A) from the value of M n determined in step 4 and the value of M n (B) determined in step 6 using the equation ns · M n (A) = M n - M n (B), and calculation of the value of M n (A) by dividing this quantity ns · M n (A) by the value of ns determined in step 3.

[0102] To determine the structural features of graft copolymers according to the invention, in which the graft backbone is the polycondensation polymer and the side chains are the vinyl (co)polymer, a similar analytical method can be used which does not differ from the previous method in steps 1) to 4), wherein step 4) is followed by the following steps: 5.) Basic saponification or acid- or basic-catalyzed complete hydrolysis of the polycondensation block, i.e., complete re-cleavage of the graft backbone into its monomeric building blocks analogous to that described previously, and subsequent separation of the remaining intact vinyl(co)polymer blocks (grafts) by precipitation followed by washing and drying. 6.) Determination of the molecular weight distribution of the vinyl(co)polymer blocks (grafts) separated in step 5 by gel permeation chromatography (GPC) and determination of the number-averaged molecular weight Mn(A) from this, whereby the GPC measurement is calibrated against the respective vinyl(co)polymer in the graft copolymer as a standard. The solvent is selected as described above. 7.) Calculation of the value M n (B) via the equation M n (B) = M n - ns ·M n (A) from the value of M n determined in step 4 , the value of M n (A) determined in step 6 and the value of ns determined in step 3 . .

[0103] In the case of graft copolymers consisting of blocks of aromatic polycarbonate and blocks of polyolefin, the NMR and GPC measurements on the graft polymer and on the polyolefin blocks optionally containing graft-active units are preferably carried out in (deuterated) ortho-dichlorobenzene at a temperature of 80 °C.

[0104] In the case of graft copolymers consisting of blocks of aromatic polycarbonate and blocks of a polymer selected from polystyrene, polymethyl methacrylate and styrene-acrylonitrile copolymers optionally containing graft-active units, the NMR measurements are preferably carried out in deuterated dichloromethane at room temperature.

[0105] GPC measurements on the graft copolymer are preferably performed in dichloromethane at room temperature and GPC measurements on the vinyl(co)polymer blocks in tetrahydrofuran at room temperature. Production of molding compounds

[0106] Molding compounds can be produced from the graft copolymers according to the invention and further components such as homopolymers A and B or polymers with similar polarity or chemical structure to that of homopolymers A and B and optionally further components.

[0107] The thermoplastic molding compounds according to the invention can be produced, for example, by mixing the respective components of the compositions in a known manner and melt-compounding and melt-extruding them at temperatures preferably of 180°C to 320°C, particularly preferably of 200°C to 300°C, and most preferably of 240°C to 290°C in conventional units such as internal kneaders, extruders and twin-screw extruders.

[0108] This process is generally referred to as compounding within the context of this application.

[0109] Molding compound is therefore understood to be the product that is obtained when the components of the composition are melt compounded and melt extruded.

[0110] The mixing of the individual components of the compositions can be carried out in a known manner, both successively and simultaneously, at approximately 20°C (room temperature) as well as at higher temperatures. This means, for example, that some of the components can be metered via the main feed of an extruder, while the remaining components can be added later in the compounding process via a side extruder.

[0111] The resulting molding compounds are a further subject of the present invention.

[0112] The molding compounds according to the invention can be used to produce molded parts. These can be manufactured, for example, by injection molding, extrusion, and blow molding. Another processing method is the production of molded parts by deep drawing from previously manufactured sheets or films. The molding compounds according to the invention are particularly suitable for processing in extrusion, blow molding, and deep drawing processes.

[0113] It is also possible to dose the components of the compositions directly into the conveying extruder of an injection molding machine, thereby producing the molding compound according to the invention in the conveying extruder and processing it directly into molded parts by appropriate discharge of the molding compound into an injection mold (compounding injection molding).

[0114] Another object of the present invention is therefore a molded body which is obtainable from a composition or molding compound according to the invention or which contains such a molding compound.

[0115] Further embodiments of the present invention are described below: 1. A graft copolymer of the general structure B-(A) ns, comprising blocks of two polymers A and B with different chemical compositions, wherein one of the polymers is a polycondensation polymer selected from the group consisting of polycarbonates, polyester carbonates, polyesters, and polyamides, and the other polymer is a polymer of at least one vinyl monomer, characterized in that (i) the number-averaged molecular weight of the block of polymer BM n (B) is at least 13 kg / mol, determined by a combination of gel permeation chromatography and NMR spectroscopy, (ii) the number of side chains in the graft copolymer ns, determined by NMR spectroscopy, is at least 3 and at most 15, (iii) the number-averaged molecular weight of the blocks of polymer AM n (A), determined by a combination of gel permeation chromatography and NMR spectroscopy, is at least 1.5 kg / mol and at most 15 kg / mol and (iv) ns multiplied by M n (A) yields at least 13 kg / mol. 2. Graft copolymer according to embodiment 1, wherein polymer A is selected from the group consisting of aromatic polycarbonates, aromatic polyester carbonates, and aromatic polyesters. 3. Graft copolymer according to embodiment 1 or 2, wherein polymer A is an aromatic polycarbonate. 4. Graft copolymer according to any of the preceding embodiments, wherein polymer B is a polymer of one or more different vinyl monomers selected from the group consisting of styrene, styrene derivatives, acrylonitrile, acrylic esters, acrylic ester derivatives, olefins, maleimide, and maleimide derivatives. 5. Graft copolymer according to embodiment 4, wherein the vinyl monomers are selected from the group consisting of styrene, acrylonitrile, methyl methacrylate, glycidyl methacrylate, and olefins. 6. Graft copolymer according to one of the preceding embodiments,where ns is at least 4. 7. Graft copolymer according to any of the preceding embodiments, wherein ns is at least 5. 8. Graft copolymer according to any of the preceding embodiments, wherein M n (A) is at least 3.0 kg / mol. 9. Graft copolymer according to any of the preceding embodiments, wherein M n (B) is at least 20 kg / mol. 10. Graft copolymer according to any of the preceding embodiments, wherein M n (B) is at least 23 kg / mol. 11. Graft copolymer according to any of the preceding embodiments, wherein the following features are present: (i) M n (B) is at least 23 kg / mol, (ii) ns is at least 5, (iii) M n (A) is at least 3.0 kg / mol, (iv) ns multiplied by M n (A) yields at least 13 kg / mol. 12. Graft copolymer according to one of the preceding embodiments, wherein ns is at least 6. 13. Graft copolymer according to one of the preceding embodiments, wherein M n (A) is at least 4,5 kg / mol. 14. Graft copolymer according to any one of the preceding claims, wherein the following features are present: (i) M n (B) is at least 23 kg / mol, (ii) ns is at least 6, (iii) M n (A) is at least 4.5 kg / mol, (iv) ns multiplied by M n (A) yields at least 13 kg / mol. 15. Graft copolymer according to any one of the preceding embodiments, wherein M n (A)·ns / [M n (B)+ M n (A)·ns ] is in the range of 0.25 to 0.75. 16. Graft copolymer according to any one of the preceding embodiments, wherein M n (A)·ns / [M n (B)+ M n (A)·ns ] is in the range of 0.40 to 0.70. 17. Graft copolymer according to one of the preceding embodiments, wherein the following features are present: (i) M n (B) is at least 23 kg / mol, (ii) ns is at least 6, (iii) M n (A) is at least 4.5 kg / mol, (iv) ns multiplied by M n (A) yields at least 13 kg / mol, (v) M n (A)·ns / [M n (B)+ M n (A)·ns ] is in the range of 0.40 to 0,70. 18. Graft copolymer according to any of the preceding embodiments, wherein Mn(A) is at least 5.3 kg / mol. 19. Graft copolymer according to any of the preceding embodiments, wherein Mn(B) is at least 30 kg / mol. 20. Graft copolymer according to any of the preceding embodiments, wherein Mn(A)·ns / [Mn(B) + Mn(A)·ns] is in the range of 0.40 to 0.60. 21. Graft copolymer according to any of the preceding embodiments, wherein ns multiplied by Mn(A) yields at least 20 kg / mol. 22. Graft copolymer according to any of the preceding embodiments, wherein ns multiplied by Mn(A) yields at least 30 kg / mol. 23. Graft copolymer according to one of the preceding embodiments, wherein ns multiplied by M n (A) yields at least 35 kg / mol. 24. Graft copolymer according to one of the preceding embodiments, wherein ns is at most 12. 25. Graft copolymer according to one of the preceding embodiments,where ns is at most 10. 26. Graft copolymer according to one of the preceding embodiments, wherein ns is at most 8. 27. Graft copolymer according to one of the preceding embodiments, wherein M n (A) is at most 12 kg / mol. 28. Graft copolymer according to one of the preceding embodiments, wherein M n (A) is at most 9 kg / mol. 29. Graft copolymer according to one of the preceding embodiments, wherein M n (A) is at most 8 kg / mol. 30. Graft copolymer according to one of the preceding embodiments, wherein M n (B) is at most 200 kg / mol. 31. Graft copolymer according to one of the preceding embodiments, wherein M n (B) is at most 100 kg / mol. 32. Graft copolymer according to one of the preceding embodiments, wherein M n (B) is at most 50 kg / mol. 33. Graft copolymer according to one of the preceding embodiments,where ns multiplied by M n (A) yields a maximum of 120 kg / mol. 34. Graft copolymer according to one of the preceding embodiments, wherein ns multiplied by M n (A) yields a maximum of 80 kg / mol. 35. Graft copolymer according to one of the preceding embodiments, wherein ns multiplied by M n (A) yields a maximum of 50 kg / mol. 36. Graft copolymer according to one of the preceding embodiments, wherein the architecture of the graft copolymer is selected from double end grafting and mid-grafting. 37. Graft copolymer according to one of the preceding embodiments,wherein the architecture of the graft copolymer is grafted centrally. 38. Use of a graft copolymer according to one of the preceding embodiments for reducing the interfacial tension in mixtures containing polymers A and B or mixtures of polymers with comparable polarity. 39. Polymer composition comprising polymers A and B and, as component C, a graft copolymer according to one of the preceding embodiments 1 to 37, wherein polymers A and B have the same chemical structure as the blocks of polymers A and B in the graft copolymer according to component C. 40. Polymer composition according to embodiment 39, wherein the ratio of the mass fraction of polymer A in the polymer composition, based on the sum of polymers A and B in the composition, to the mass fraction of the graft strands in the graft copolymer according to component C is 0.6 to 1.4. 41. Polymer composition according to embodiment 40, wherein the ratio at 0,7 to 1.3. 42. Polymer composition according to embodiment 40, wherein the ratio is 0.8 to 1.2. 43. Polymer composition according to one of embodiments 39 to 42, wherein the graft copolymer is used in a concentration of 0.1 to 20 wt.%. 44. Polymer composition according to one of embodiments 39 to 42, wherein the graft copolymer is used in a concentration of 1.0 to 10 wt.%. 45. Polymer composition according to one of embodiments 39 to 42, wherein the graft copolymer is used in a concentration of 2 to 5 wt.%. 46. Molding compound obtained from a composition according to one of embodiments 39 to 45. 47. Molded body containing a composition according to one of embodiments 39 to 45. 48. Molded body produced from a molding compound according to embodiment 46. Examples Simulation of interfacial tension

[0116] The influence of the structure of a graft copolymer, composed of blocks of two different polymers A and B, on the interfacial tension at the phase interface in polymer blends of homopolymers A and B was investigated using computer-aided simulation. A dissipative particle dynamics simulation was employed. The simulation was performed using the open-source program LAMMPS ("LAMMPS - a flexible simulation tool for particle-based materials modeling at the atomic, meso, and continuum scales", AP Thompson, HM Aktulga, R. Berger, DS Bolintineanu, WM Brown, PS Crozier, PJ in 't Veld, A. Kohlmeyer, SG Moore, TD Nguyen, R. Shan, MJ Stevens, J. Tranchida, C. Trott, SJ Plimpton, Comp Phys Comm, 271 (2022) 10817).

[0117] The procedure used in the simulations is described below. For the sake of linguistic simplicity, some explanations are written in the present tense, but the actual procedure used is meant.

[0118] In dissipative particle dynamics simulation ("dissipative particle dynamics") = In DPD simulations, relatively large molecules, in this case polymers, are modeled by spheres ("beads") that interact through pairwise interaction potentials. A sphere in the DPD simulation represents a cluster consisting of several monomer units of the polymer. These spheres move under the influence of their interaction forces according to Newton's laws of motion. The total force acting on each individual sphere is represented by the sum of conservative, dissipative, and random forces. The simulation uses the following characteristic quantities: r c as a unit of length ("cut-off distance"), m as a unit of mass, k BT as a unit of energy (with kb as the Boltzmann constant and T as temperature) and t dpd = r c m / k B T as a unit of time.

[0119] In the following, the spheres that make up homopolymers A and B are referred to as a and b, respectively. The same applies to the spheres that make up the corresponding blocks of the graft copolymers. This results in a simplified characterization of the graft copolymers using three characteristic quantities (lb, ls, and ns). lb is the number of spheres that make up the backbone of the graft copolymer and is thus a measure of its molecular weight. ls is the number of spheres that make up a graft strand and is thus a measure of its molecular weight. ns is the number of side chains (graft strands) that are grafted onto the graft copolymer backbone, whereby in the simulation, with the exception of the three special molecular architectures (ii) to (iv) defined below, these side chains were always grafted equidistantly across the entire graft copolymer backbone.The terms "graft fast" and "side chain" are used synonymously here.

[0120] A special embodiment of such graft copolymers investigated within the simulations are thus uniformly equidistantly grafted graft copolymers. In such graft copolymers, the graft strands are uniformly equidistantly distributed along the entire graft copolymer backbone. This results in a spacing of the side chains Isp (in units of the number of spheres), which can be described by the equation Isp. = 1 + [(lb - ns ) / (ns + 1)] calculated.

[0121] Within the context of the examples in this application, a special nomenclature was defined for such uniformly equidistantly grafted copolymers: For example, the nomenclature b 31 (a 4 ) 3 denotes a graft copolymer which is composed of a graft copolymer backbone consisting of 31 spheres of type b, onto which 3 blocks, each composed of 4 spheres of type a, are grafted at equidistant intervals. The architecture of such uniformly equidistantly grafted copolymers, which formed the basis of the simulation, is described in Figure 2 schematically illustrated using the example of the graft copolymer b 31 (aa ) 3. The in Figure 2 The exemplary graft copolymer molecule b 31 (a 4 ) 3 thus consists of a total of 31 spheres of type b and 3·4 = 12 spheres of type a.

[0122] In the DPD simulations performed within the scope of this invention, the sphere size was chosen such that the masses of the spheres of type a and b are as similar as the molecular masses of the monomer units allow; that is, the molecular masses of the spheres of type a and b are essentially equal. Thus, the mass fraction of polymer blocks A and B in the graft copolymer corresponds essentially to the fraction of spheres of type a and b in the graft copolymer. The fraction of spheres of type b in a graft copolymer molecule consisting of a graft copolymer backbone of polymer A and graft stems of polymer blocks B is calculated according to the equation x = ns · ls / (lb + ns · ls ).

[0123] Within the scope of this invention, DPD simulations were performed for different uniformly equidistant grafted graft copolymers according to the architecture in Figure 2 carried out with systematically varied values ​​of ns, ls, and lb.

[0124] Furthermore, graft copolymer architectures were simulated comparatively in which the molecular weight of the copolymer backbone, the number of grafts, and the molecular weight of the grafts were kept constant at lb = 47, ls = 8, and ns = 11, respectively, but the grafts were arranged differently on the copolymer backbone, i.e., grafted onto it. In addition to the graft copolymer (i) with the architecture according to Figure 1In a model where the graft strands are arranged uniformly and equidistantly on the copolymer backbone ("uniformly equidistantly grafted"), graft copolymers with a side chain spacing of Isp = 1 were simulated: (ii) where all 11 graft strands were arranged entirely at one end of the graft copolymer backbone ("single-terminal grafted"), (iii) where 5 or 6 of the 11 graft strands were arranged at each end of the graft copolymer backbone ("double-terminal grafted"), and (iv) where all 11 graft strands were arranged in the middle of the graft copolymer backbone ("mid-positional grafted"). The molecular architectures of these three specific graft copolymers (ii) to (iv) are described in Figure 1schematically represented and contrasted with the architecture of the uniformly equidistantly grafted graft copolymer (i). In accordance with the nomenclature described above, the four graft copolymers (i) - (iv) can be described as follows, where the square brackets each encompass a contiguous section of a homopolymer block or graft copolymer block: (i) b 47 (a 8 ) 11 (ii) b 11 a 8 11 − b 36 (iii) b 5 a 8 5 − b 36 − b 6 a 8 6 (iv) b 18 − b 11 a 8 11 − b 18

[0125] The simulation of the phase compatibility mediation efficiency caused by graft copolymers, built from blocks of polymers A and B, in two-phase blends of homopolymers A and B comprised the following process steps: 1. Formation of an initial configuration of the molecules in the simulation box

[0126] Procedure step 1 comprised the following two sub-steps:

[0127] 1.1 The Cartesian coordinates of one homopolymer molecule of type A and one of type B, as well as of one graft copolymer molecule composed of blocks of polymers A and B, were first determined using the coordinates of the spheres forming these polymers. The initial bond length between two spheres was set to the value 0.2· r c . During the simulation, the bond length changes under the influence of the interaction forces, i.e., the final bond lengths in the simulated equilibrium state generally do not correspond to the values ​​in the initial state of the simulation.

[0128] 1.2 In total, 162,000 DPD spheres were placed in a periodic box with dimensions of 30 × 30 × 60. r c 3 The spheres were distributed largely uniformly and statistically, avoiding molecular overlaps. This resulted in a sphere density of 3. r c − 3 , which, according to general expert experience, allows for the accurate representation of the thermodynamics of fluids. The initial configuration was set with a distance tolerance of 0.5 r c As shown, in this process step 1.2, the number of homopolymer molecules A and B was chosen such that equal mass concentrations resulted for both homopolymers; that is, the simulation is performed in a blend of homopolymers A and B with a mass fraction of 50 wt% for each. The polymer molecules of type A and B from process step 1.1 were replicated and placed in different halves of the simulation box. Molecules consisting of 60 spheres each were used in the simulation for both homopolymers A and B. Then, nc =200 graft copolymer molecules of the respective architecture were placed near the interface between homopolymers A and B. This initial configuration accelerates the formation of a thermodynamic equilibrium state at the interface during the DPD simulation. In each simulation, all 200 graft copolymer molecules have the same architecture with respect to the selected values ​​of ns, ls, and lb, and the spatial distribution of the graft branches on the graft backbone. 2. Simulation of the dynamics of the polymer molecules up to the thermodynamic equilibrium state.

[0129] The positions and momenta of the DPD beads were calculated in discrete time interval steps in continuous phase space. The motion was simulated by an algorithm that numerically solves the classical Newtonian equation of motion (4). r ˙ i = P i m i und P ˙ i = f i

[0130] In equation (4) fi the force acting on the ball i with the mass mi is exerted by the sum of the other balls, and Pi the momentum of this sphere. The stepwise numerical integration of equation (1) was performed using the Verlet algorithm.

[0131] The power fi , which is on the ball i The force exerted by the ensemble of other spheres is given by equation (5) as the sum of the pairwise interaction forces. F ij the sphere i with the other balls j described in the simulation box, where these pairwise interaction forces have a conservative force component F ij C , a dissipative force component F ij D and a random force component F ij R include: f i = ∑ i ≠ j F ij C + F ij D + F ij R

[0132] The dissipative force component F ij D = − ηω D r ij v ij e ij e ij and the random force component F ij R = σω R< ( r ij )ξ ij Δ t -1 / 2< e ijThey act together as a thermostat, whereby η and σ represent the friction parameter and the noise amplitude with η = σ 2< / 2k BT ; r ij = r i - r j , v ij = v i - v j as the relative speed of the balls i and j and e ij = r ij / r ij · ω D< ( r ij ) and ω R< ( r ij ) are the location-dependent weighting functions for the dissipative and random force components. ξ ij is a Gaussian-distributed random number with a mean of zero for the respective interaction of the balls i and j in each time interval Δ t. The simulations carried out as part of this application were ω D< ( r ij ) = [ ω R< ( r ij )] 2< and σ = 3 selected. The conservative force component F ij C = α ij 1 − r ij / r c e ij r ij < r c is repulsive and via the repulsion parameter α ij defined.

[0133] The repulsion parameter between polymers A and B, α AB , can be determined according to equation (6) using the Flory-Huggins parameter χ AB put into perspective. α AB = α AA + 3 , 27 χ AB

[0134] α AA and α BB These are the repulsion parameters of chemically identical molecules, i.e., A with A or B with B, where the value used here is α AA = α BB = 25 k B Tr c − 1 The compressibility of a fluid is represented as accurately as possible based on experience. A higher value of α AB This means a higher incompatibility between polymer species A and B, i.e., a greater repulsion.

[0135] The binding interactions between two directly adjacent spheres of the same polymer molecule were described in the simulations underlying this application via a harmonic spring force. F ij S = − C r ij with C = 4 , 0 k B Tr c − 2 modeled as the spring constant of a harmonic oscillator.

[0136] The simulation continued until the mean squared radius of gyration of the simulation system became constant over time, with this constant being chosen as the criterion for reaching an equilibrium state. After reaching this equilibrium state, 2 × 10⁶ further simulation steps were calculated (Δ t = 0.06 t dpd ) . In step 4 (as described below), the interfacial tension y was determined from the equilibrium configuration generated in this way. 3. Mapping to a real polymer system

[0137] "Mapping" refers to the step in the simulation process where the spheres of type a and b and the repulsion parameter are defined. α AB were assigned to real polymer species or oligomeric units of real polymer species.

[0138] Each sphere from which the polymers for the simulation are assembled represents an oligomeric unit of the respective polymer in the simulation, that is, a structural unit composed of a number n of monomeric building blocks. If a concrete, real polymer is assigned to the abstract polymer system, the specific value of n can be determined for each polymer, whereby this value varies for chemically different polymers with different molar masses of the repeating unit. The determination of n This is done under the condition that the spheres of type a and b, from which the homo- and graft copolymers for the simulation are composed, have approximately the same volume and therefore approximately the same mass.

[0139] In the second step of the "mapping", the value of the repulsion parameter can be determined for a specific AB polymer system. α AB from the Flory-Huggins parameter χ ABaccording to equation (6). After in the first step of the "mapping" each sphere of type a and b was assigned a specific oligomeric unit of the respective polymer A and B, composed of n monomeric building blocks, the value for χ AB The activity coefficient was determined using the COSMO-RS model. For this purpose, the activity coefficient was calculated for an equimolar mixture of oligomeric units constructed from n monomeric building blocks of polymers A and B. γ The activity coefficient of A in the mixture was calculated quantum chemically using the COSMO-RS model and the Biova COSMOtherm 2019 software (Dassault Systèmes). γ The Flory-Huggins parameter was then calculated according to equation (7). χ AB = V tot x A V A lnγ A − ln 1 − x A V A V tot − 1 − 1 V B V A x A V A V tot

[0140] In equation (7) x A represents the molar fraction of A in the mixture (in our case, therefore x A = 0.5), VA and VB are the volumes of species A and B and V tot = VA + VB .

[0141] COSMO-RS ("COnductor-like Screening Model for Real Solvents") is a quantum-chemical-based equilibrium thermodynamic simulation method known to those skilled in the art for predicting chemical potentials in fluids. Details of the COSMO-RS model and its application to problems such as those in this application are known to those skilled in the art, for example, from the review article by A. Klamt, "The COSMO and COSMO-RS solvation models", WIREs Comput Mol Sci 2018, 8:e1338. doi: 10.1002 / wcms.1338 and the works cited therein.

[0142] In this way, two different polymer systems were assigned ("mapped") and subsequently subjected to DPD simulations: System 1: Polymer B (graft backbone) = polystyrene, Polymer A (graft stems) = bisphenol-A-based polycarbonate System 2: Polymer B (graft backbone) = polypropylene, Polymer A (graft stems) = bisphenol-A-based polycarbonate

[0143] For these two systems, the "mapping" process yielded the values ​​for α AB and the molar masses of the spheres of type a (M a ) and b (M b ) for a temperature of 100 °C according to Table 1, which were used as the basis for the simulation. Table 1 graft backbone Grafts α AB M b [g mol -1< ] M a [g mol -1< ] polystyrene Polycarbonat 28 668 792 Polypropylen Polycarbonat 35 717 792

[0144] Using the molar masses of the spheres of type A and B according to Table 1, the values ​​for the number of spheres in the graft backbone lb and in the graft stems ls can be converted into molar masses of the graft backbone M n (B) and the graft stems M n (A) by multiplication. 4. Determination of the interfacial tension and the efficiency of the graft copolymers as phase compatibility mediators from the equilibrium configuration of the DPD simulation

[0145] The interfacial tension γ was determined from the equilibrium configuration resulting in process step 3 according to equation (8) γ = L z 2 P zz − 1 2 P xx + P yy P xx , P yyand P zz These are the diagonal components of the pressure tensor, which were calculated according to equation (9). P kk = 1 V ∑ i = 1 N m i v ik v jk + ∑ i = 1 N − 1 ∑ j = i + 1 N F ijk r ijy where N the total number of balls and V = L x × L y × L z Represent the volume of the simulation box. The interfacial tension determined analogously for the comparable blend of homopolymers A and B in the absence of graft copolymer molecules, i.e., for the uncompatible blend. γ 0 is used in determining the phase compatibility mediator efficiency. E = (1 - γ / γ 0 ) of the respective graft copolymer as a reference.

[0146] The obtained phase compatibility mediator efficiency E is shown in Tables 2 and 3 for various graft copolymer structures. The number of side chains (ns), the molecular weight M n (B) of the backbone, and the molecular weight M n (A) of a single side chain were varied. From this, the molecular weights for the graft copolymers (from M n (B) + ns multiplied by M n (A)), M n (A) multiplied by ns, and the molar mass fraction in wt% that the side chains constitute in the graft copolymer (mass fraction of grafts) can be calculated. The simulations were performed for graft copolymers that have either a polystyrene (PS, Table 2) or polypropylene (PP, Table 3) backbone. In both cases, the side chains are composed of bisphenol-A-based polycarbonate.

[0147] Table 4 shows the influence of the graft architecture according to the designations (i) to (iv) used above, with the same molecular weights Mn of the backbone and side chains for each graft copolymer system. All graft copolymers according to architectures (i) to (iv) exhibited 11 side chains. The investigations were carried out with both polystyrene and polypropylene as the graft copolymer backbone and, in all cases, with bisphenol A-based polycarbonate as the side chains. Table 2: Uniformly equidistant grafted copolymers with polystyrene (PS) as backbone and simulated values ​​for E Nr. backbone ns M n (B) (backbone) [kg / mol] M n (A) (Pfropfast) [kg / mol] M n (A) xns (total graft branches) [kg / mol] M n Graft copolymer [kg / mol] Mass proportion of grafted grafts E 1 PS 6 42,1 6,3 38,0 80,1 0,47 67 2 PS 6 31,4 6,3 38,0 69,4 0,55 63 3 PS 6 26,1 6,3 38,0 64,1 0,59 56 4 PS 11 42,1 6,3 69,7 111,8 0,62 53 5 PS 11 20,7 5,5 61,0 81,7 0,75 51 6 PS 3 42,1 6,3 19,0 61,1 0,31 50 7 PS 7 20,7 5,5 38,8 59,5 0,65 49 8 PS 6 20,7 6,3 38,0 58,7 0,65 48 9 PS 11 42,1 3,2 34,8 76,9 0,45 47 10 PS 9 20,7 5,5 49,9 70,6 0,71 46 11 PS 11 31,4 6,3 69,7 101,1 0,69 45 12 PS 11 26,1 6,3 69,7 95,7 0,73 43 13 PS 11 31,4 3,2 34,8 66,2 0,53 42 14 PS 5 20,7 5,5 27,7 48,4 0,57 42 15 PS 11 20,7 3,2 34,8 55,6 0,63 41 16 PS 6 31,4 3,2 19,0 50,4 0,38 41 17 PS 4 20,7 6,3 25,3 46,1 0,55 41 18 PS 6 15,4 6,3 38,0 53,4 0,71 40 19 PS 11 26,1 3,2 34,8 60,9 0,57 39 20 PS 11 20,7 6,3 69,7 90,4 0,77 38 21 PS 6 42,1 3,2 19,0 61,1 0,31 38 22 PS 3 31,4 6,3 19,0 50,4 0,38 38 23 PS 4 20,7 7,1 28,5 49,2 0,58 38 24 PS 6 26,1 3,2 19,0 45,1 0,42 36 25 PS 4 20,7 7,9 31,7 52,4 0,60 36 26 PS 4 20,7 5,5 22,2 42,9 0,52 36 27 PS 11 20,7 2,4 26,1 46,8 0,56 34 28 PS 6 20,7 3,2 19,0 39,7 0,48 33 29 PS 4 20,7 4,8 19,0 39,7 0,48 33 30 PS 3 26,1 6,3 19,0 45,1 0,42 33 31 PS 7 20,7 2,4 16,6 37,3 0,45 33 32 PS 11 42,1 1,6 17,4 59,5 0,29 32 33 PS 9 20,7 2,4 21,4 42,1 0,51 32 34 PS 11 31,4 1,6 17,4 48,8 0,36 32 35 PS 3 20,7 6,3 19,0 39,7 0,48 31 36 PS 6 15,4 3,2 19,0 34,4 0,55 30 37 PS 3 15,4 6,3 19,0 34,4 0,55 30 38 PS 11 15,4 6,3 69,7 85,1 0,82 30 39 PS 4 20,7 4,0 15,8 36,5 0,43 30 40 PS 11 20,7 1,6 17,4 38,1 0,46 30 V41 PS 6 10,0 6,3 38,0 48,0 0,79 27 V42 PS 3 42,1 3,2 9,5 51,6 0,18 27 V43 PS 1 42,1 6,3 6,3 48,4 0,13 27 V44 PS 3 26,1 3,2 9,5 35,6 0,27 27 V45 PS 3 31,4 3,2 9,5 40,9 0,23 26 V46 PS 3 15,4 3,2 9,5 24,9 0,38 26 V47 PS 6 10,0 1,6 9,5 19,5 0,49 24 V48 PS 4 20,7 3,2 12,7 33,4 0,38 24 V49 PS 6 42,1 1,6 9,5 51,6 0,18 23 V50 PS 6 10,0 3,2 19,0 29,0 0,65 23 V51 PS 11 10,0 1,6 17,4 27,4 0,63 23 V52 PS 11 20,7 0,8 8,7 29,4 0,30 22 V53 PS 6 7,3 3,2 19,0 26,4 0,72 22 V54 PS 4 7,3 4,8 19,0 26,4 0,72 22 V55 PS 1 31,4 6,3 6,3 37,7 0,17 22 V56 PS 4 7,3 7,9 31,7 39,0 0,81 22 V57 PS 6 20,7 1,6 9,5 30,2 0,31 22 V58 PS 3 20,7 3,2 9,5 30,2 0,31 22 V59 PS 4 20,7 2,4 9,5 30,2 0,31 22 V60 PS 3 10,0 6,3 19,0 29,0 0,65 21 V61 PS 3 10,0 3,2 9,5 19,5 0,49 21 V62 PS 6 31,4 1,6 9,5 40,9 0,23 21 V63 PS 4 7,3 4,0 15,8 23,2 0,68 21 V64 PS 4 7,3 3,2 12,7 20,0 0,63 21 V65 PS 3 7,3 3,2 9,5 16,9 0,56 21 V66 PS 4 7,3 2,4 9,5 16,9 0,56 21 V67 PS 6 26,1 1,6 9,5 35,6 0,27 21 V68 PS 1 7,3 6,3 6,3 13,7 0,46 21 V69 PS 3 7,3 6,3 19,0 26,4 0,72 20 V70 PS 1 26,1 6,3 6,3 32,4 0,20 20 V71 PS 1 15,4 6,3 6,3 21,7 0,29 20 V72 PS 4 20,7 1,6 6,3 27,0 0,23 20 V73 PS 3 20,7 2,4 7,1 27,8 0,26 20 V74 PS 11 10,0 3,2 34,8 44,9 0,78 20 V75 PS 3 7,3 1,6 4,8 12,1 0,39 19 V76 PS 6 15,4 1,6 9,5 24,9 0,38 19 V77 PS 6 7,3 6,3 38,0 45,4 0,84 18 V78 PS 4 7,3 7,1 28,5 35,9 0,80 18 V79 PS 7 20,7 0,8 5,5 26,3 0,21 18 V80 PS 1 10,0 6,3 6,3 16,4 0,39 17 V81 PS 4 7,3 5,5 22,2 29,5 0,75 17 V82 PS 1 31,4 3,2 3,2 34,6 0,09 17 V83 PS 5 20,7 0,8 4,0 24,7 0,16 16 V84 PS 3 42,1 1,6 4,8 46,8 0,10 16 V85 PS 4 7,3 1,6 6,3 13,7 0,46 16 V86 PS 3 26,1 1,6 4,8 30,8 0,15 16 V87 PS 3 31,4 1,6 4,8 36,1 0,13 16 V88 PS 1 20,7 6,3 6,3 27,0 0,23 16 V89 PS 3 10,0 1,6 4,8 14,8 0,32 16 V90 PS 9 20,7 0,8 7,1 27,8 0,26 15 V91 PS 1 10,0 3,2 3,2 13,2 0,24 15 V92 PS 1 20,7 3,2 3,2 23,9 0,13 15 V93 PS 4 20,7 0,8 3,2 23,9 0,13 15 V94 PS 1 7,3 3,2 3,2 10,5 0,30 15 V95 PS 4 7,3 0,8 3,2 10,5 0,30 15 V96 PS 1 42,1 3,2 3,2 45,3 0,07 14 V97 PS 11 7,3 3,2 34,8 42,2 0,83 14 V98 PS 3 15,4 1,6 4,8 20,1 0,24 14 V99 PS 3 20,7 1,6 4,8 25,5 0,19 13 V100 PS 4 7,3 6,3 25,3 32,7 0,78 13 V101 PS 6 7,3 1,6 9,5 16,9 0,56 13 V102 PS 11 10,0 6,3 69,7 79,7 0,87 13 V103 PS 11 7,3 1,6 17,4 24,8 0,70 12 V104 PS 1 26,1 3,2 3,2 29,2 0,11 12 V105 PS 1 15,4 3,2 3,2 18,5 0,17 12 V106 PS 11 7,3 6,3 69,7 77,0 0,90 12 V107 PS 1 20,7 2,4 2,4 23,1 0,10 11 V108 PS 1 20,7 1,6 1,6 22,3 0,07 10 V109 PS 1 20,7 5,5 5,5 26,3 0,21 10 V110 PS 1 26,1 1,6 1,6 27,6 0,06 10 V111 PS 1 31,4 1,6 1,6 33,0 0,05 9 V112 PS 3 20,7 0,8 2,4 23,1 0,10 9 V113 PS 1 10,0 1,6 1,6 11,6 0,14 9 V114 PS 1 15,4 1,6 1,6 16,9 0,09 9 V115 PS 1 42,1 1,6 1,6 43,7 0,04 8 V116 PS 1 7,3 1,6 1,6 8,9 0,18 5 V117 PS 1 20,7 0,8 0,8 21,5 0,04 5 Table 3 : Uniformly equidistant grafted copolymers with polypropylene (PP) as backbone and simulated values ​​for E Nr. backbone ns M n (B) (backbone) [kg / mol] M n (A) (Pfropfast) [kg / mol] M n (A) xns (total graft branches) [kg / mol] M n Graft copolymer [kg / mol] Mass proportion of grafted grafts E 118 PP 6 45,2 6,3 38,0 83,2 0,46 82 119 PP 11 45,2 6,3 69,7 114,9 0,61 78 120 PP 11 22,2 5,5 61,0 83,2 0,73 77 121 PP 11 45,2 3,2 34,8 80,0 0,44 75 122 PP 9 22,2 5,5 49,9 72,1 0,69 74 123 PP 4 22,2 7,1 28,5 50,7 0,56 73 124 PP 11 22,2 3,2 34,8 57,1 0,61 66 125 PP 4 22,2 7,9 31,7 53,9 0,59 65 126 PP 7 22,2 5,5 38,8 61,0 0,64 63 127 PP 6 45,2 3,2 19,0 64,2 0,30 62 128 PP 4 22,2 6,3 25,3 47,6 0,53 62 129 PP 11 22,2 6,3 69,7 91,9 0,76 58 130 PP 5 22,2 5,5 27,7 49,9 0,55 54 131 PP 11 22,2 1,6 17,4 39,7 0,44 53 132 PP 11 45,2 1,6 17,4 62,6 0,28 53 133 PP 4 22,2 5,5 22,2 44,4 0,50 51 134 PP 6 22,2 6,3 38,0 60,2 0,63 51 135 PP 3 22,2 5,5 16,6 38,9 0,43 46 136 PP 6 22,2 3,2 19,0 41,2 0,46 37 137 PP 4 22,2 4,8 19,0 41,2 0,46 37 138 PP 3 45,2 6,3 19,0 64,2 0,30 31 139 PP 4 22,2 4,0 15,8 38,1 0,42 30 V140 PP 3 45,2 3,2 9,5 54,7 0,17 29 V141 PP 6 7,9 6,3 38,0 45,9 0,83 29 V142 PP 4 7,9 7,9 31,7 39,6 0,80 29 V143 PP 6 22,2 1,6 9,5 31,7 0,30 27 V144 PP 4 7,9 7,1 28,5 36,4 0,78 27 V145 PP 11 7,9 3,2 34,8 42,7 0,82 27 V146 PP 4 7,9 6,3 25,3 33,2 0,76 26 V147 PP 4 7,9 5,5 22,2 30,1 0,74 24 V148 PP 3 45,2 1,6 4,8 49,9 0,10 22 V149 PP 4 22,2 3,2 12,7 34,9 0,36 21 V150 PP 11 7,9 1,6 17,4 25,3 0,69 20 V151 PP 11 7,9 6,3 69,7 77,6 0,90 20 V152 PP 6 7,9 3,2 19,0 26,9 0,71 18 V153 PP 4 7,9 4,8 19,0 26,9 0,71 18 V154 PP 4 7,9 4,0 15,8 23,7 0,67 16 V155 PP 6 7,9 1,6 9,5 17,4 0,55 13 V156 PP 3 7,9 6,3 19,0 26,9 0,71 13 V157 PP 4 7,9 3,2 12,7 20,6 0,62 13 V158 PP 3 22,2 1,6 4,8 27,0 0,18 16 V159 PP 1 45,2 6,3 6,3 51,5 0,12 12 V160 PP 3 7,9 3,2 9,5 17,4 0,55 12 V161 PP 3 7,9 1,6 4,8 12,6 0,38 11 V162 PP 4 7,9 1,6 6,3 14,2 0,45 11 V163 PP 1 45,2 1,6 1,6 46,8 0,03 11 V164 PP 1 45,2 3,2 3,2 48,3 0,07 10 V165 PP 3 22,2 3,2 9,5 31,7 0,30 16 V166 PP 4 22,2 1,6 6,3 28,6 0,22 13 V167 PP 1 7,9 6,3 6,3 14,2 0,45 9 V168 PP 1 22,2 6,3 6,3 28,6 0,22 12 V169 PP 7 22,2 0,8 5,5 27,8 0,20 10 V170 PP 1 22,2 3,2 3,2 25,4 0,12 10 V171 PP 4 7,9 0,8 3,2 11,1 0,29 8 V172 PP 1 7,9 3,2 3,2 11,1 0,29 8 V173 PP 1 7,9 1,6 1,6 9,5 0,17 7 V174 PP 4 22,2 0,8 3,2 25,4 0,12 10 V175 PP 11 22,2 0,8 8,7 30,9 0,28 10 V176 PP 9 22,2 0,8 7,1 29,4 0,24 9 V177 PP 3 22,2 0,8 2,4 24,6 0,10 9 V178 PP 5 22,2 0,8 4,0 26,2 0,15 9 V179 PP 1 22,2 1,6 1,6 23,8 0,07 8 V180 PP 1 22,2 5,5 5,5 27,8 0,20 5 V181 PP 1 22,2 0,8 0,8 23,0 0,03 5 Table 4: Influence of graft architecture on E Nr. Grafting architecture backbone ns M n (B) (backbone) [kg / mol] M n (A) (Pfropfast) [kg / mol] M n (A) xns (total graft branches) [kg / mol] M n Graft copolymer [kg / mol] Mass proportion of grafted grafts E 11 uniformly equidistant PS 11 31,4 6,3 69,7 101,1 0,69 45 182 simply terminal PS 11 31,4 6,3 69,7 101,1 0,69 46 183 medium-sized PS 11 31,4 6,3 69,7 101,1 0,69 78 184 double terminal PS 11 31,4 6,3 69,7 101,1 0,69 66 185 uniformly equidistant PP 11 33,7 6,3 69,7 103,4 0,67 72 186 simply terminal PP 11 33,7 6,3 69,7 103,4 0,67 52 187 medium-sized PP 11 33,7 6,3 69,7 103,4 0,67 88 188 double terminal PP 11 33,7 6,3 69,7 103,4 0,67 81

[0148] The data in Tables 2 and 3 show that only the embodiments of the graft copolymers according to the invention exhibit increased phase compatibility mediator efficiency in the sense of a value of E = (1 - γ / γ 0 ) of at least 30.

[0149] Furthermore, evaluations of the data in Tables 2 and 3 show that above a certain value for M n (A) a further increase in the value of this quantity does not result in any significant further improvements in the phase compatibility mediator efficiency in terms of a higher value of E = (1 - γ / γ0) have a greater effect. This can be seen, for example, from a plot of E against M n (A) for all values ​​from Table 2 with a constant M n (B) of, for example, 20.7 kg / mol and a constant ns of, for example, 4. As explained above, however, the aim is for the graft copolymers to exert their effective action at the lowest possible molecular weight. It follows that M n (A) must not be greater than 15 kg / mol to achieve the required balance between good phase compatibility mediator efficiency. E and good mobility in the polymer melt, thus enabling rapid attainment of the phase interface.

[0150] Similarly, evaluations of the data in Tables 2 and 3 show that above a certain value for ns, a further increase in the value of this quantity does not result in any significant further improvements in the phase compatibility mediator efficiency in terms of a higher value of E = (1 - γ / γ0) have a greater effect. This can be seen, for example, from a plot of E against ns for all values ​​from Table 2 with a constant M n (B) of, for example, 20.7 kg / mol and a constant M n (A) of, for example, 5.5 kg / mol. The same applies to a plot of E against ns for all values ​​from Table 3 with a constant M n (B) of, for example, 22.2 kg / mol and a constant M n (A) of, for example, 5.5 kg / mol. For reasons analogous to those explained above for M n (A), an upper limit of ns of 15 results in order to obtain a graft copolymer with good phase compatibility mediator efficiency E and good mobility in the polymer melt.

[0151] Evaluations of the data in Tables 2 and 3 further show that above a value of the product M n (A) xns of approximately 50 kg / mol, a further increase in the value of this quantity does not result in any significant further improvements in the phase compatibility mediator efficiency in terms of a higher value of E = (1 - γ / γ 0 ) more effect. This can be seen, for example, from a plot of E against M n (A) xns for all values ​​from Table 2 with a constant M n (B) of, for example, 20.7 kg / mol or for all values ​​from Table 3 with a constant M n (B) of, for example, 22.2 kg / mol, but also from corresponding plots for other constant M n (B) values ​​in the range according to the invention.

[0152] Finally, evaluations of the data in Tables 2 and 3 show that above a value for M n (B) of approximately 50 kJ / mol, a further increase in the value of this quantity does not result in any significant further improvements in the phase compatibility mediator efficiency in terms of a higher value of E. = (1 - γ / γ 0 ) have a greater effect. This can be seen, for example, from a plot of E against M n (B) for all values ​​from Table 2 with a constant M n (A) of, for example, 6.3 kg / mol and a constant ns of, for example, 11.

[0153] Above the aforementioned values ​​for M n (B), M n (A), ns and M n (A) xns, the phase compatibility mediator efficiency of the graft copolymer in the equilibrium state improves only slightly, if at all; on the other hand, further increases in these parameters characterizing the graft copolymer are contrary to the desired goal of maximizing its mobility in the polymer melt mixture by minimizing the molecular weight of the graft copolymer and thus accelerating the establishment of equilibrium.

[0154] The data in Table 4 show that graft copolymers with a double end graft and, in particular, a mid-graft architecture exhibit improved phase compatibility mediator efficiency compared to graft copolymers with a uniformly equidistant graft and, in particular, a single end graft architecture that are comparable in terms of their chemical composition, number of graft branches, and molar masses of the graft backbone and graft branches, in terms of their graft composition, number of graft branches, and molar masses of the graft backbone and graft branches. E = (1 - γ / γ exhibit 0 ).

[0155] For selected simulation experiments from Table 2, the number of simulation steps required to reach equilibrium was evaluated. The results of this analysis are presented in Table 5. Table 5: Selected experiments and number of simulation steps Nr. backbone ns M n (B) (backbone) [kg / mol] M n (A) (Pfropfast) [kg / mol] M n (A) xns (total graft branches) [kg / mol] M n Graft copolymer [kg / mol] E Number of simulation steps until equilibrium 4 polystyrene 11 42,1 6,3 69,7 111,8 53 1,6E+06 9 polystyrene 11 42,1 3,2 34,8 76,9 47 1,3E+06 6 polystyrene 3 42,1 6,3 19,0 61,1 50 1,1E+06

[0156] The data in Table 5 confirm that with higher values ​​of Mn(A), Mn(B), and ns, and thus with a higher molar mass Mn of the graft copolymer and a higher value of the product Mn(A) x ns, more simulation steps are necessary to achieve a steady-state equilibrium. Applied to a real polymer mixture, this means that a longer time is required until a stable distribution of the graft copolymer in the mixture, and thus a stable morphology of the components—polymers A and B, as well as the graft copolymer—is established. This necessitates increasing the residence time in the mixing unit, such as an extruder, which is often difficult to achieve with the equipment or entails other disadvantages, such as thermal damage to the polymer components.The number of simulation steps required to achieve a steady-state equilibrium is greatly influenced by the number ns of grafts (experiments 4 and 6), followed by the value of M n (A), i.e. the molecular weight of the grafts (experiments 4 and 9), and consequently, in particular, by the value of the product M n (A) xns (all data in Table 5).

[0157] The data in Table 5 thus lead to the conclusion that, with regard to minimizing the number of simulation steps required to achieve equilibrium, or, translated into technical terms, minimizing the residence times necessary to reach such a desired equilibrium state, it is advisable to choose the values ​​of ns and M n (A), and especially the value for the product M n (A) x ns, no higher than absolutely necessary to achieve the desired phase compatibility mediator efficiency E. This consideration results in upper limits for the values ​​of these three characteristics, above which the improvement in phase compatibility mediator efficiency E is minimal or negligible.no longer significantly improved, but the residence times required to achieve the equilibrium state to be set in order to realize this phase compatibility mediator efficiency E increase sharply.

[0158] Corresponding investigations into the number of simulation steps to equilibrium were also carried out for the preferred graft copolymers with specific graft architectures ("double end graft" and "mid-graft"). These investigations revealed no influence of the architecture compared to the "uniformly equidistantly grafted" copolymers, with identical values ​​for ns, Mn(A) and Mn(B). This means that the number of simulation steps to equilibrium was the same for all three different graft copolymer architectures, within the limits of the accuracy of this parameter.

Claims

1. Graft copolymer of the general structure B-(A)ns consisting of blocks of two polymers A and B of differing chemical composition, wherein one of the polymers is a polycondensation polymer selected from the group consisting of polycarbonates, polyestercarbonates, polyesters, and polyamides and the other polymer is a polymer composed of at least one vinyl monomer, characterized in that (i) the number-average molecular weight of the block of polymer B Mn(B) is at least 13 kg / mol, determined by a combination of gel-permeation chromatography and NMR spectroscopy, (ii) the number of side chains in the graft copolymer ns, determined by NMR spectroscopy, is at least 3 and not more than 15, (iii) the number-average molecular weight of the blocks of polymer A Mn(A) is at least 1.5 kg / mol and not more than 15 kg / mol, determined by a combination of gel-permeation chromatography and NMR spectroscopy, and (iv) ns multiplied by Mn(A) comes to at least 13 kg / mol.

2. Graft copolymer according to Claim 1, wherein polymer A is selected from the group consisting of aromatic polycarbonates, aromatic polyestercarbonates, and aromatic polyesters.

3. Graft copolymer according to Claim 1 or 2, wherein polymer A is an aromatic polycarbonate.

4. Graft copolymer according to any of the preceding claims, wherein polymer B is a polymer of one or more different vinyl monomers selected from the group consisting of styrene, styrene derivatives, acrylonitrile, acrylic esters, acrylic ester derivatives, olefins, maleimide, and maleimide derivatives.

5. Graft copolymer according to Claim 4, wherein the vinyl monomers are selected from the group consisting of styrene, acrylonitrile, methyl methacrylate, glycidyl methacrylate, and olefins.

6. Graft copolymer according to any of the preceding claims, characterized in that the following features are present: (i) Mn(B) is at least 23 kg / mol, (ii) ns is at least 6, (iii) Mn(A) is at least 4.5 kg / mol, (iv) ns multiplied by Mn(A) comes to at least 13 kg / mol, and (v) Mn(A)·ns / [Mn(B)+ Mn(A)·ns] is in the range from 0.40 to 0.70.

7. Graft copolymer according to any of the preceding claims, wherein ns is not more than 12.

8. Graft copolymer according to any of the preceding claims, wherein Mn(B) is not more than 200 kg / mol.

9. Graft copolymer according to any of the preceding claims, wherein Mn(A) is not more than 12 kg / mol.

10. Graft copolymer according to any of the preceding claims, wherein ns multiplied by Mn(A) is not more than 80 kg / mol.

11. Graft copolymer according to any of the preceding claims, wherein the architecture of the graft copolymer is selected from doubly terminally grafted and centrally grafted.

12. Use of a graft copolymer according to any of the preceding claims for reducing the interfacial tension between phases in mixtures comprising polymers A and B.

13. Polymer composition comprising polymers A and B and, as component C, a graft copolymer according to any of the preceding Claims 1 to 11, wherein polymers A and B have the same chemical structure as the blocks of polymers A and B in the graft copolymer corresponding to component C.

14. Polymer composition according to Claim 13, wherein the ratio of the mass fraction of polymer A in the polymer composition, based on the sum total of polymers A and B in the composition, to the mass fraction of the graft branches in the graft copolymer corresponding to component C is 0.6 to 1.4.

15. Moulded article comprising a composition according to either of Claims 13 or 14.