POLYSILOXANE-POLYCARBONATE BLOCK COCONDESATE MADE FROM SPECIALLY TERMINATED SILOXANE BLOCKS

Description

[0001] The present invention relates to a process for the production of polysiloxane-polycarbonate block cocondensates (hereinafter also referred to as SiCoPC) using specially terminated polysiloxanes, polysiloxane-polycarbonate block cocondensates with at least one Si-OC bond and fine siloxane domains, a molding compound containing the polysiloxane-polycarbonate block cocondensate according to the invention, a molded part containing the polysiloxane-polycarbonate block cocondensate according to the invention, the use of a special bisphenol as a termination group of a polysiloxane to increase the reactivity of the polysiloxane, and the use of a specially terminated polysiloxane in the production of a polysiloxane-polycarbonate block cocondensate to increase the proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks.

[0002] Polysiloxane-polycarbonate block cocondensates are known to exhibit good properties with regard to low-temperature impact strength, low-temperature notched impact strength, chemical resistance, weathering resistance, aging properties, and flame resistance. In some of these properties, they are superior to conventional polycarbonates (for example, homopolycarbonate based on bisphenol A).

[0003] These cocondensates are industrially produced from monomers, mostly via the interfacial process with phosgene. Furthermore, the production of these polysiloxane-polycarbonate block cocondensates via the melt transesterification process using diphenyl carbonate is also known. These processes have the disadvantage that the industrial plants used for them are designed for the production of standard polycarbonate and are therefore quite large. The production of special block cocondensates on these plants is often not economically viable due to the smaller volume of these products. Moreover, the feedstocks required for the production of the cocondensates, such as polydimethylsiloxanes, can negatively impact the plant, as they can lead to contamination of the equipment or the solvent circuits.Furthermore, the production process requires difficult-to-handle raw materials such as phosgene or, as in the melt transesterification process, a high energy demand.

[0004] The production of polysiloxane-polycarbonate block cocondensates via the phase interface process is known from the literature and is described, for example, in US-PS 3 189 662, US-PS 3 419 634, DE-OS 3 34 782, US 2008 / 0081893A1 and EP 0 122 535.

[0005] The production of polysiloxane-polycarbonate block copolymers by melt transesterification from bisphenol, diaryl carbonate, silanol-terminated polysiloxanes, and a catalyst is described in US 5,227,449. Polydiphenyl or polydimethylsiloxane telomers with silanol end groups are used as the siloxane compounds. However, it is known that such dimethylsiloxanes with silanol end groups, unlike diphenylsiloxanes with silanol end groups, increasingly tend to self-condense in acidic or basic media with decreasing chain length, thus making their incorporation into the resulting copolymer difficult. The cyclic siloxanes formed in this process remain in the polymer and are extremely problematic in electrical / electronic applications.

[0006] US Patent 5,504,177 describes the production of a polysiloxane-polycarbonate block cocondensate via melt transesterification from a carbonate-terminated silicone with bisphenol and diaryl carbonate. Due to the high incompatibility of siloxanes with bisphenol and diaryl carbonate, uniform incorporation of the siloxanes into the polycarbonate matrix via the melt transesterification process is either impossible or extremely difficult to achieve.

[0007] A disadvantage of all these processes is the use of organic solvents in at least one step of the synthesis of polysiloxane-polycarbonate block cocondensates, the use of phosgene as a starting material, or the insufficient quality of the cocondensate. In particular, the synthesis of the cocondensates from the monomers is very complex, both in the interfacial process and especially in the melt transesterification process. For example, in melt processes, a low vacuum and low temperatures must be used to prevent evaporation and thus the removal of the monomers. Only in later reaction stages, in which oligomers with higher molar mass have formed, can lower pressures and higher temperatures be applied. This means that the reaction must be carried out in several stages, and the reaction times are correspondingly long.

[0008] To avoid the disadvantages described above, reactive extrusion processes for the production of siloxane-based block copolycarbonates have also been described. This has been published, for example, in US 5414054 and US 5821321. Here, a conventional polycarbonate is reacted with a special polydimethylsiloxane in a reactive extrusion process. A disadvantage of this process, however, is the use of special silicone components, which are expensive. Furthermore, this process uses highly effective transesterification catalysts, which enable the production of the cocondensates within short residence times on an extruder. However, these transesterification catalysts remain in the product and cannot be inactivated, or only insufficiently. Therefore, injection-molded parts made from the cocondensates produced in this way exhibit unsatisfactory aging behavior, particularly inadequate thermal aging behavior.Therefore, the resulting block copolycarbonate is not suitable for high-quality applications. Compared to a block copolycarbonate produced using the interface process, this product does not exhibit the corresponding properties, such as aging behavior and mechanical properties.

[0009] Prior art siloxane blocks often feature Si-C bonds. For the purposes of the present invention, the terms "Si-C bond" and / or "Si-OC bond" preferably refer to polysiloxanes that have a termination. This termination is preferably an organic residue with a phenolic OH group. This organic residue with the phenolic OH group is preferably linked via a Si-C bond or a Si-OC bond. It is also possible that a Si-C bond and / or a Si-OC bond is present at another position in the polysiloxane. However, it is preferred that this involves at least the linkage of the end group (termination group) to the siloxane group.

[0010] Si-C bonds are significantly more hydrolytically stable than Si-OC bonds. However, polysiloxane blocks containing Si-C bonds must be prepared via complex hydrosylation using Pd or Pt catalysis. Such catalysts are expensive. Typical polydimethylsiloxanes with Si-C bonds are shown in formulas (I) to (III): where n and m in formulas (I) to (III) respectively represent the average number of repetition units.

[0011] Polysiloxanes with Si-OC bonds, on the other hand, are significantly easier to access without the use of expensive Pd or Pt catalysts. For example, hydroquinone or BPA-terminated siloxanes are known to possess a Si-OC linkage (see, for example, WO 2013 155046A1).

[0012] However, it was found that BPA or hydroquinone-terminated polysiloxanes are not incorporated completely homogeneously into the block cocondensate. According to the invention, the term "non-homogeneous incorporation" preferably means that the siloxane portion of the acetone-soluble polymer fraction contains only small amounts of polycarbonate or oligocarbonate. This highly polysiloxane-rich phase can degrade the polymer morphology to such an extent that large phases are formed in polysiloxane-rich regions. Without being bound to any specific theory, it can be assumed that the formation of such large siloxane domains is partly due to the high tendency of polysiloxanes with Si-OC and / or Si-C bonds to self-condense. According to the invention, "self-condensation" preferably refers to the reaction of one polysiloxane block with another polysiloxane block.In contrast to polysiloxanes with Si-C linkages, polysiloxanes with Si-OC linkages also appear to exhibit a tendency towards self-condensation, even when no carbonate donors such as phosgene or a diaryl carbonate such as diphenyl carbonate are involved in the reaction. Therefore, preventing self-condensation seems to pose a significant challenge, particularly for polysiloxanes with Si-OC bonds.

[0013] A large siloxane domain size negatively impacts the processing properties of SiCoPC. Large domains can lead to segregation, which manifests as an inhomogeneous surface structure and can sometimes result in flow lines and streaking. Because large domains are shear-sensitive, such materials are also difficult to process using injection molding, resulting in very narrow processing windows. This often necessitates very low injection speeds, which is frequently undesirable as it reduces cycle time.

[0014] In particular, large siloxane domains are formed during the production of block condensates in the melt according to the state of the art.

[0015] The siloxane domain size of a SiCoPC in the phase interface process using Si-C bonded siloxane blocks is typically below 100 nm. This allows for the production of translucent or even transparent materials, as the small domain size results in minimal light scattering.

[0016] The production of siloxane-containing block cocondensates starting from Si-C-linked polydimethylsiloxane blocks with low turbidity is known in principle. In WO 2004016674 A1, a precondensate is produced from an oligocarbonate and siloxane using a phase interface process and then further condensed with a bisphenol using a phase interface process in a second step.

[0017] The melt transesterification process has the disadvantage that it is generally not possible to work with dilute solutions, and the reactants are always present in highly concentrated form. Experience has shown that this leads to the formation of siloxane domains with a size between 0.1 and 10 µm. SiCoPCs based on dihydroxydiphenylcycloalkanes of formula (1) are known in principle. For example, such structures are described in DE3926850. However, these are block cocondensates built from dihydroxydiphenylcycloalkanes, meaning the polymers contain the specific bisphenol in the polymer chain. This influences the properties of the resulting SiCoPC (especially the glass transition temperature). This is not always desirable for a variety of reasons.

[0018] EP 3 036 279 A1 also describes polysiloxanes that can have different terminations. Termination with dihydroxydiphenylcycloalkanes is described, but these are not preferred. The application provides no information on the incorporation behavior of such siloxane blocks in polycarbonate.

[0019] WO2016162301A1 describes a process for the production of siloxane-containing block cocondensates containing dihydroxydiphenylcycloalkanes. The corresponding block cocondensates are produced by melt transesterification. However, here too, the dihydroxydiphenylcycloalkanes are present in both the polycarbonate substructure and the siloxane substructure.

[0020] Document US 2018 / 079862 A1 uses a bisphenol according to the given formula (3) to produce polysiloxane carbonate copolymers. However, there is no formation of a direct SiOC bond between the siloxane and the bisphenol (3).

[0021] Based on the prior art, the objective was therefore to overcome at least one, preferably all, disadvantages of the prior art. In particular, the objective of the present invention was to minimize the self-condensation of polysiloxanes containing at least one Si-OC bond during the production of a SiCoPC. Instead, the reaction of the polysiloxane with the bisphenol, the oligocarbonate, or the polycarbonate should preferably take place. Polysiloxanes containing at least one Si-OC bond should be used to avoid the complex and expensive hydrosilylation via Pd or Pt catalysis. In particular, the objective of the present invention was to provide a polysiloxane-polycarbonate block cocondensate that does not have a significant polysiloxane-rich fraction (with only a small PC fraction) and is characterized by a particularly fine siloxane domain distribution.If the SiCoPC has a significant polysiloxane-rich content, the effects described above occur. The polysiloxane-polycarbonate block cocondensate should preferably be produced by melt transesterification. In particular, the object of the present invention was to provide a polysiloxane-polycarbonate block cocondensate in which at least 50 vol%, particularly preferably at least 75 vol%, and most preferably at least 90 vol% of all siloxane domains of the siloxane domain distribution of the polysiloxane-polycarbonate block cocondensate lie in a range greater than 0 to 50 nm.

[0022] At least one of the aforementioned problems, preferably all of the aforementioned problems, has been solved by the present invention.

[0023] Surprisingly, it was shown that polysiloxane blocks containing Si-OC bonds and terminated with cycloaliphatic-substituted or cycloaliphatic-containing bisphenols exhibit significantly more homogeneous incorporation into SiCoPC. Furthermore, they display a finer phase morphology. This suggests that the self-condensation of the polysiloxane could be slowed, suppressed, or minimized by the specific termination. The reactivity of the specifically terminated polysiloxane towards compounds with the structure of formula (2) appears to be greater than towards other specifically terminated polysiloxanes. This was surprising because the cycloaliphatic bisphenols differ only slightly from alkyl-containing bisphenols such as isopropylidene bisphenol (BPA). The improved siloxane domain size resulted in enhanced processing properties of the SiCoPC.The tendency to segregate was reduced and the processing window for injection molding of the polycarbonate compositions according to the invention was widened.

[0024] Without wishing to be bound to any theory, the specially terminated polysiloxane block of the present invention could, through its cycloaliphatic structure, possess steric hindrance and / or electronic stabilization, which makes the Si-OC bond more stable or minimizes the tendency to self-condense.

[0025] According to the invention, the term "more homogeneous incorporation into the SiCoPC" preferably means that a proportionally larger proportion of siloxane blocks are covalently bonded to polycarbonate blocks than when a BPA-terminated (bisphenol A-terminated) siloxane block is used under the same conditions. The BPA-terminated siloxane block preferably has the same structure as the polysiloxane used according to the invention, with the difference that the BPA structures have been replaced by the defined cycloaliphatic bisphenols.

[0026] Likewise, according to the invention, the expression "finer siloxane domains" or "finer phase morphology" is preferably understood to mean that the siloxane domains and / or the phase morphology is smaller than when a BPA-terminated siloxane block is used under otherwise identical conditions.

[0027] According to the invention, a process for producing a polysiloxane-polycarbonate block cocondensate is therefore provided, which is formed by the reaction of at least one polysiloxane of formula (1) wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, phenyl or C7-C12 aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6 alkyl, p is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represent an aliphatic or aromatic group, preferably methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, -CH2-CH(CH3)-phenyl, -CH2-CH2-CH2-(2-methoxy)phenyl or phenyl, n represents an average number of repeating units from 10 to 400, preferably 10 to 100, particularly preferably 15 to 50 and m represents an average number of repeating units of 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5. (i) with at least one compound of formula (2) and / or (2I) in the presence of at least one base and phosgene in the interfacial phase process, (ii) with at least one compound of formula (2) and at least one diaryl carbonate in the melt transesterification process, or (iii) with at least one compound of formula (2II) and optionally at least one diaryl carbonate in the melt transesterification process, wherein wherein each Z in formula (2), (2I) or (2II) independently represents a single bond, -S(=O)₂-, -C(=O)-, -O-, -S-, -S(=O)-, -CH(CN)-, a linear or branched C₁-C₆ alkylene group, which may optionally comprise at least one carbonyl group, may optionally have at least one halogen atom and / or may optionally be interrupted by at least one heteroatom, a C₂-C₁₀ alkylidene group, which may optionally have at least one carbon-carbon double bond, may optionally have at least one carbonyl group and / or may optionally have at least one halogen atom, each R₇ and R₈ in formula (2), (2I) or (2II) independently represents hydrogen, halogen, C₁-C₈ alkyl, C₃-C₆ cycloalkyl, C₁-C₄ alkoxy, phenyl or C₇-C₁₂ Aralkyl, where o in formula (2I) or (2II) represents the average number of repeating units, and 2 to 40,preferably 7 to 31, Y in formula (2II) represents hydrogen or -(C=O)-O-Ph, where Ph represents an optionally substituted phenyl and Y 1 in formula (2II) represents optionally substituted phenyl or a compound of formula (2IIa), where , wherein each Z, R 7 and R 8 has the meanings given for formula (2II) and "*" represents the position where the structure of formula (2IIa) connects to formula (2II) as Y 1.

[0028] According to the invention, a polysiloxane of formula (1) is preferably used, wherein each R 1 and R 2 independently represents hydrogen or C 1-C 8 alkyl, particularly preferably hydrogen, R 3 and R 4 are individually selectable for each X and independently represent hydrogen or C 1-C 3 alkyl, particularly preferably hydrogen or methyl, p is an integer from 4 to 7, preferably 4 to 6, particularly preferably 4 to 5, and X represents carbon, each R 5 and R 6 independently represent methyl, ethyl, trimethylphenyl, -CH 2-CH 2-phenyl, -CH 2-CH 2-CH 2-phenyl, -CH 2-CH(CH 3 )-phenyl, -CH 2-CH 2-CH 2-(2-methoxy)phenyl or phenyl, preferably methyl or phenyl, n represents an average number of repeating units from 10 to 400, preferably 10 up to 100, particularly preferably 15 to 50, and m represents an average number of repetition units of 1 to 10, preferably 1 to 6.especially preferred 1.5 to 5.

[0029] It is evident to the expert that formula (1) above can also be represented by formula (100). wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, phenyl or C7-C12 aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6 alkyl, n is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represent an aliphatic or aromatic group, preferably methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, -CH2-CH(CH3)-phenyl, -CH2-CH2-CH2-(2-methoxy)phenyl or phenyl, n represents an average number of repeating units from 10 to 400 and m represents an average number The number of repetition units ranges from 1 to 10.

[0030] According to the invention, a polysiloxane of formula (1) is particularly preferably used, wherein each R 1 and R 2 represents hydrogen, R 3 and R 4 are individually selectable for each X and independently represent hydrogen or methyl, p is an integer 4 or 5 and X represents carbon, each R 5 and R 6 independently represent methyl or phenyl, n represents an average number of repeating units of 10 to 400, preferably 10 to 100, particularly preferably 15 to 50, and m represents an average number of repeating units of 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5.

[0031] A polysiloxane of formula (1A) is particularly preferred, wherein wherein each RI independently represents hydrogen or methyl, n represents an average number of repeating units of 10 to 400, preferably 10 to 100, particularly preferably 15 to 50, and m represents an average number of repeating units of 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5. Particularly preferably, each RI in formula (1A) represents methyl.

[0032] Within the scope of the present invention, the term "termination" of the polysiloxane of formula (1) is frequently used. Termination preferably means that all ends of the polysiloxane (generally 2) have a specific organic group (see, for example, formula (1)).

[0033] The specially terminated polysiloxanes of formula (1) can be prepared by various methods. For example, the specially terminated polysiloxanes can be obtained by reacting bisacetoxyacyloxy-terminated siloxane blocks with the corresponding dihydroxydiphenylcycloalkanes. The preparation of acyloxy-terminated siloxanes is described, for example, in EP0003285 and US4584360. Furthermore, the specially terminated polysiloxanes can be prepared via alpha,omega-dichloropolydimethylsiloxanes. This is described, for example, in US3821325. In this process, for example, the dichlorosiloxane compound is reacted with the corresponding cycloaliphatic bisphenol in an inert solvent at temperatures between 0 and 100 °C in the presence of an acid acceptor.

[0034] The molecular weight (Mw) of the polysiloxane is preferably 2,000 to 20,000 g / mol and particularly preferably 2,500 to 15,000 g / mol. The molecular weight is preferably determined as defined below.

[0035] The polysiloxane of formula (1) is preferably used in a ratio of 0.5 to 50 wt.%, preferably 1 to 40 wt.%, particularly preferably 2 to 20 wt.% and most preferably 2.5 to 10 wt.% based on the sum of the weights of the polysiloxane of formula (1) and the compound comprising the structure of formula (2), (2I) and / or (2II) (depending on which of these compounds are used).

[0036] According to the invention, the polysiloxane of formula (1) reacts (i) with at least one compound of formula (2) and / or (2I) in the presence of at least one base and phosgene in the interfacial phase process, (ii) with at least one compound of formula (2) and at least one diaryl carbonate in the melt transesterification process or (iii) with at least one compound of formula (2II) and optionally at least one diaryl carbonate in the melt transesterification process.

[0037] It is preferred that each Z in formula (2), (2I) or (2II) independently represents a single bond, -S(=O) 2 -, -C(=O)-, -O-, -S-, -S(=O)-, -CH(CN)-, a linear or branched C 1 -C 6 alkylene group or a C 2 -C 10 alkylidene group and each R 7 and R 8 in formula (2), (2I) or (2II) independently represents hydrogen, C 1 -C 8 alkyl or C 1 -C 4 alkoxy.

[0038] In particular, it is preferred that each Z in formula (2), (2I) or (2II) independently represents a single bond or a C 2-C 6 alkylidene group and each R 7 and R 8 in formula (2), (2I) or (2II) independently represents hydrogen, C 1-C 3 alkyl or C 1-C 2 alkoxy.

[0039] It is particularly preferred that each Z in formula (2), (2I) or (2II) independently represents a single bond or isopropylidene and each R 7 and R 8 in formula (2), (2I) or (2II) independently represents hydrogen or methoxy, preferably hydrogen.

[0040] According to the invention, the polysiloxane of formula (1) is reacted with at least one compound of formula (2), (2I), or (2II). It is also conceivable that at least two compounds of formula (2), (2I), or (2II) are reacted with the polysiloxane of formula (1). It is particularly preferred that, in the first compound of formula (2), (2I), or (2II), Z represents isopropylidene and R7 and R8 represent hydrogen. It is also preferred that, in the second compound of formula (2), (2I), or (2II), Z represents a single bond and R7 and R8 represent hydrogen.

[0041] In particular, it is preferred that Z in formula (2), (2I) or (2II) represents isopropylidene. Accordingly, formula (2), (2I) or (2II) is derived from bisphenol A.

[0042] The specified values ​​of o represent the average number of repetition units. The term "average number of repetition units" is known to those skilled in the art. Those skilled in the art know how to determine this parameter. In particular, this parameter can be determined using GPC. Preferably, it is determined using the GPC method as described in the context of the present invention.

[0043] In the context of the present invention, the term "alkyl" or "alkyl group" preferably refers, unless otherwise specified, to an alkane structure from which a hydrogen atom has been removed. The alkyl group according to the present invention can be linear or branched. It is saturated and therefore comprises only single bonds between the adjacent carbon atoms. The alkyl group preferably includes methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1,2-Dimethylpropyl, 1-Methylpentyl, 2-Methylpentyl, 3-Methylpentyl, 4-Methylpentyl, 1,1-Dimethylbutyl, 1,2-Dimethylbutyl, 1,3-Dimethylbutyl, 2,2-Dimethylbutyl, 2,3-Dimethylbutyl, 3,3-Dimethylbutyl, 1-Ethylbutyl, 2-Ethylbutyl, 1,1,2-Trimethylpropyl, 1,2,2-Trimethylpropyl, 1-Ethyl-1-methylpropyl, 1-Ethyl-2-methylpropyl, 1-Ethyl-2-methylpropyl and the like.The selection of these structures may be limited if the number of carbon atoms is defined differently within the scope of the present invention.

[0044] In the context of the present invention, the term "alkylene" or "alkylene group" preferably refers, unless otherwise specified, to a bridging alkane structure from which two hydrogen atoms have been removed from different carbon atoms. In this context, the two hydrogen atoms removed from the two carbon atoms can be from any carbon atoms in the alkane structure. This means that the two carbon atoms can be adjacent, but need not be. An alkylene group can be linear or branched. It is saturated. If the alkylene group comprises only one carbon atom, it is a methylene group (-CH₂-) which is connected to the rest of the molecule via two single bonds.Preferably, the alkylene group comprises methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, tert-butylene, n-pentylene, 1-methylbutylene, 2-methylbutylene, 3-methylbutylene, neopentylene, 1-ethylpropylene, n-hexylene, 1,1-dimethylpropylene, 1,2-dimethylpropylene, 1,2-dimethylpropylene, 1-methylpentylene, 2-methylpentylene, 3-methylpentylene, 4-methylpentylene, 1,1-dimethylbutylene, 1,2-dimethylbutylene, 1,3-dimethylbutylene, 2,2-dimethylbutylene, 2,3-dimethylbutylene, 3,3-dimethylbutylene, 1-ethylbutylene, 2-ethylbutylene 1,1,2-Trimethylpropylene, 1,2,2-Trimethylpropylene, 1-Ethyl-1-methylpropylene, 1-Ethyl-2-methylpropylene, 1-Ethyl-2-methylpropylene, and the like. The selection of these structures may be limited if, within the scope of the present invention, the number of carbon atoms is defined differently.Furthermore, according to the present invention, the alkylene group may optionally comprise at least one carbonyl group, optionally at least one halogen atom, and / or optionally be interrupted by at least one heteroatom. Examples of such alkylene groups are -C(=O)-(CH₂)₄-C(=O)-, -C(=O)-(CH₂)₃-C(=O)-, -C(=O)-(CH₂)₂-C(=O)-, -C(CF₃)₂, -O-(CH₂)₄-O-, -O-(CH₂)₃-O-, -O-(CH₂)₂-O-, and the like.

[0045] In the context of the present invention, the term "alkylidene" or "alkylidene group" preferably refers, unless otherwise specified, to a bridging alkane structure in which two hydrogen atoms have been removed from the same carbon atom. The alkylidene group optionally comprises at least one carbon-carbon double bond, optionally at least one carbonyl group, and / or optionally at least one halogen atom. Preferably, the alkylidene group comprises isopropylidene, n-propylidene, isoheptylidene, and the like.

[0046] In the context of the present invention, the term "aralkyl" preferably and, unless otherwise specified, in each case refers independently to a linear, cyclic or branched alkyl group which is singly, doubly or multiply substituted with aryl groups.

[0047] In the context of the present invention, the term "alkoxy" or "alkoxy group" preferably refers, unless otherwise specified, to a linear, cyclic, or branched alkyl group simply bonded to an oxygen atom (-OR). Preferably, alkoxy groups according to the present invention have 1 to 6 carbon atoms. Particularly preferably, alkoxy groups comprise methoxy, ethoxy, n-propoxy, iso-propoxy, n-Nutoxy, sec-butoxy, tert-butoxy, n-pentoxy, 1-methylbutoxy, 2-methylbutoxy, 3-methylbutoxy, neo-pentoxy, 1-ethylpropoxy, cyclohexoxy, cyclopentoxy, n-hexoxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy, 1,2-dimethylpropoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-Ethyl-1-methylpropoxy, 1-Ethyl-2-methylpropoxy, or 1-Ethyl-2-methylpropoxy. The selection of these structures may be limited if the number of carbon atoms is defined differently within the scope of the present invention.

[0048] Based on the definitions mentioned above, a person skilled in the art is able to understand further definitions which are not explicitly mentioned above.

[0049] The reaction of the polysiloxane according to (i) with at least one compound of formula (2) and / or (2I) is carried out according to the invention by an interfacial reaction. These processes and their specific procedures are known to those skilled in the art. The interfacial reaction is carried out with phosgene and in the presence of a base. The use of at least one base in the interfacial reaction is also known to those skilled in the art. In particular, this is an aqueous alkali or alkaline earth metal hydroxide solution. Most preferably, the at least one base is an aqueous sodium hydroxide solution.

[0050] The interfacial phase process is described, for example, in H. Schnell, Chemistry and Physics of Polycarbonates, Polymer Reviews, Vol. 9, Interscience Publishers, New York 1964, page 33 et seq., and in Polymer Reviews, Vol. 10, "Condensation Polymers by Interfacial and Solution Methods", Paul W. Morgan, Interscience Publishers, New York 1965, chapter VIII, page 325, and the reaction conditions used are known to those skilled in the art. Furthermore, the interfacial phase process for the production of polycarbonate is also described, for example, in EP-A 0517044.

[0051] In the interfacial phase process, a disodium salt of a diol / bisphenol or a mixture of different diols / bisphenols, prepared in an aqueous alkaline solution or suspension, is typically phosgenated in the presence of an organic solvent or solvent mixture. This solvent is usually inert and forms a second organic phase in addition to the aqueous phase. The resulting oligocarbonates, mainly present in the organic phase, are condensed with suitable catalysts to form high-molecular-weight polycarbonates dissolved in the organic phase. The molecular weight can be controlled by suitable chain terminators (e.g., monofunctional phenols). The organic phase is then separated, and the polycarbonate is isolated from it through various processing steps.

[0052] Condensation typically takes place in an inert solvent in the presence of alkali and a catalyst at the interface.

[0053] It is known to those skilled in the art that, as a rule, the OH end groups of the compounds of formulas (1), (2), and / or (2I) do not react directly with each other. The reaction is carried out in the presence of a base. This allows salts to form. Furthermore, the reaction can be influenced by varying the timing of the addition of the reactants in a manner known to those skilled in the art. In particular, the compound of formula (2) and / or (2I) can be phosgenated together with the polysiloxane of formula (1), the components can be phosgenated separately, or only one of the components can react with phosgene. Different dilutions can also be used. It is also apparent to those skilled in the art that the compound of formula (2) can be converted into the compound of formula (2I) depending on the reaction procedure.An advantageous method for the phase interface process with regard to avoiding self-condensation of polysiloxanes (with Si-C bonds) is described in US20040039145A.

[0054] Alternatively, the polysiloxane of formula (1) is reacted according to (ii) or (iii) in a melt transesterification process. This process and the operating procedure are also known to those skilled in the art. The reaction is solvent-free and proceeds by condensation in the melt, starting from the compound of formula (2) with at least one diaryl carbonate or of formula (2II) and optionally at least one diaryl carbonate, as well as the specifically terminated polysiloxane. The process according to the invention is preferably carried out according to (ii) or (iii). The process according to the invention according to (iii) is particularly preferred. It is apparent to those skilled in the art that there is a certain overlap between (ii) and (iii). In particular, a compound of formula (2II) can be formed by the reaction according to (ii), so that (ii) can also be transformed into (iii). According to the invention, a sharp distinction between (ii) and (iii) does not appear to be necessary.

[0055] The melt transesterification process is described, for example, in Encyclopaedia of Polymer Science, Vol. 10 (1969), Chemistry and Physics of Polycarbonates, Polymer Reviews, H. Schnell, Vol. 9, John Wiley and Sons, Inc. (1964), and DE-C 10 31 512. It is also known to those skilled in the art in melt transesterification that the compounds of formula (2) and / or (2II) do not necessarily have to react directly, but may, through further reactions, exhibit other end groups. The process according to the invention is particularly preferred in that the polysiloxane of formula (1) (iii) reacts with at least one compound of formula (2II) in the melt transesterification process.

[0056] Preferably, the diaryl carbonate is a compound of formula (III) where R4 and R5 independently of each other represent H, C1-C34-alkyl, C7-C34-aralkyl, C6-C34-aryl or -COO-R', where R' corresponds to a C1-C34-alkyl, C7-C34-aralkyl, C6-C34-aryl, and m and m1 independently represent an integer from 1 to 5, and where m is a number from 2 to 5, each residue R4 can be the same or different, and where m1 is a number from 2 to 5, each residue R5 can be the same or different.

[0057] The diaryl carbonate is particularly preferably diphenyl carbonate, 4-tert-butylphenyl phenyl carbonate, di-(4-tert-butylphenyl) carbonate, biphenyl-4-yl phenyl carbonate, di-(biphenyl-4-yl) carbonate, 4-(1-methyl-1-phenylethyl)-phenyl phenyl carbonate and di-[4-(1-methyl-1-phenylethyl)-phenyl] carbonate, most preferably diphenyl carbonate.

[0058] If the process according to the invention is carried out in the melt transesterification process, it is further preferred that the process according to the invention is carried out on an extruder, high-viscosity reactors or thin-film evaporators.

[0059] The extruder or melting reactor can be a single-shaft reactor, a twin-shaft reactor, or a multi-shaft reactor, such as a planetary roller extruder or ring extruder. It can also be a high-volume kneading reactor. The process can be carried out on a single unit—e.g., a twin-shaft extruder—or in two stages, i.e., a reactor combination. The reactor combination preferably consists of a pre-reactor—such as a twin-shaft extruder—and a high-viscosity reactor. Advantageous process configurations are described in particular in EP21187927 and EP21187920.

[0060] Furthermore, it is preferred that the compound, comprising the structure of formula (2I), has a relative solution viscosity ηrel of 1.08 to 1.22, preferably 1.11 to 1.22, and particularly preferably 1.13 to 1.20. The relative solution viscosity (ηrel; also referred to as ηrel) is preferably determined in dichloromethane at a concentration of 5 g / l at 25 °C using an Ubbeloh deviscometer. The determination of the relative solution viscosity using an Ubbeloh deviscometer is known to those skilled in the art. According to the invention, this is preferably carried out in accordance with DIN 51562-3; 1985-05. The flow times of the compound to be measured through the Ubbelohde viscometer are measured in order to subsequently determine the viscosity difference between the polymer solution and its solvent.First, the Ubbelohde viscometer is calibrated by measuring the pure solvents dichloromethane, trichloroethylene, and tetrachloroethylene (at least 3 measurements, at most 9 measurements are always taken). Then, the actual calibration is performed using dichloromethane. The sample is then weighed, dissolved in dichloromethane, and the flow time for this solution is determined three times. The mean of the flow times is corrected using the Hagenbach correction, and the relative solution viscosity is calculated.

[0061] The compound comprising the structure of formula (2I) is preferably a polycarbonate. Polycarbonates within the meaning of the present invention are homopolycarbonates, copolycarbonates, and mixtures of polycarbonates. The polycarbonates can be linear or branched in a known manner. The polycarbonates can be produced in a known manner by melt transesterification or by interfacial phase synthesis.

[0062] Preferably, such polycarbonates have molecular weights (Mw) of 8,000 to 19,000 g / mol, particularly preferably of 10,000 to 18,000 g / mol, and especially preferably of 12,000 to 18,000 g / mol. Furthermore, these polycarbonates preferably have a phenolic OH group content of 250 ppm to 2,500 ppm, preferably 500 to 2,000 ppm, and particularly preferably of 1,000 to 1,800 ppm. The phenolic OH groups are preferably determined by IR spectroscopy.

[0063] The method used to determine the molar masses of the polycarbonate, polysiloxane, or polysiloxane-polycarbonate block cocondensate specified in the invention is Method No. 2301-0257502-09D of Currenta GmbH & Co. OHG (from 2009), which can be obtained from Currenta at any time. Calibration is performed using linear polycarbonates (from bisphenol A and phosgene) with a known molar mass distribution from PSS Polymer Standards Service GmbH, Germany. The eluent is dichloromethane. The columns are made of cross-linked styrene-divinylbenzene resins. Diameter of the analytical columns: 7.5 mm; length: 300 mm. Particle sizes of the column material: 3 µm to 20 µm. Solution concentration: 0.2 wt%. Flow rate: 1.0 ml / min; solution temperature: 30°C. Detection using a refractive index (RI) detector, UV detector or IR detector, preferably a refractive index detector.Particularly preferably, detection is carried out using an RI detector or a UV detector, each combined with an IR detector. The RI and UV detectors are especially sensitive to polymer chains containing polycarbonate (particularly BPA-containing polycarbonate). To also detect polymer chains containing polysiloxane (particularly polydimethylsiloxane-containing polymer chains), the IR detector is preferably tuned to the Si-O vibrational band, which is approximately 1050 cm⁻¹. The simultaneous use of UV, RI, and IR detectors is preferred.

[0064] When the melt transesterification process is used to produce SiCoPC, polycarbonates containing certain rearrangement structures are used in a preferred embodiment. The polycarbonates to be used in this embodiment contain at least one, preferably several, of the following structures (4) to (7): in which the phenyl rings can be independently substituted singly or doubly with C1-C8 alkyl, halogen, preferably C1 to C4 alkyl, particularly preferably with methyl and X represents a single bond, C1 to C6 alkylene, C2 to C5 alkylidene or C5 to C6 cycloalkylidene, preferably a single bond or C1 to C4 alkylene and particularly preferably isopropylidene, wherein the total amount of structural units (4) to (7) (determined after saponification) is generally in the range of 50 to 1000 ppm, preferably in the range of 80 to 850 ppm.

[0065] To determine the amount of rearrangements, the respective polycarbonate is subjected to total saponification, forming the corresponding degradation products of formulas (4a) to (7a), the quantities of which are determined by HPLC. Structures (4a) to (7a) are given as examples for the use of a polycarbonate comprising bisphenol A. (This can be done, for example, as follows: The polycarbonate sample is saponified with sodium methylate under reflux. The resulting solution is acidified and concentrated to dryness. The drying residue is dissolved in acetonitrile, and the phenolic compounds of formulas (1a) to (4a) are determined by HPLC with UV detection.)

[0066] Preferably the amount of the compound of formula (4a) released is 20 to 800 ppm, particularly preferably 25 to 700 ppm and particularly preferably 30 to 500 ppm.

[0067] Preferably the amount of the compound of formula (5a) released is 0 (i.e. below the detection limit of 10 ppm) to 100 ppm, particularly preferably 0 to 80 ppm and particularly preferably 0 to 50 ppm.

[0068] Preferably, the amount of the compound of formula (6a) released is 0 (i.e., below the detection limit of 10 ppm) to 800 ppm, more preferably 10 to 700 ppm, and particularly preferably 20 to 600 ppm, and most preferably 30 to 350 ppm. Preferably, the amount of the compound of formula (7a) released is 0 (i.e., below the detection limit of 10 ppm) to 300 ppm, more preferably 5 to 250 ppm, and particularly preferably 10 to 200 ppm.

[0069] The production of such polycarbonates containing the above-mentioned rearrangement structures is described, for example, in DE 102008019503.

[0070] The process is preferably carried out in the melt transesterification process at temperatures of 280 °C to 400 °C, preferably from 290 °C to 380 °C, more preferably from 300 °C to 350 °C and pressures of 0.001 mbar to 50 mbar, preferably 0.005 mbar to 40 mbar, particularly preferably 0.02 to 30 mbar and most preferably 0.03 to 5 mbar, preferably in the presence of a catalyst.

[0071] Preferably, the reaction according to (i) to (iii) in the process according to the invention is carried out in the presence of at least one catalyst. While a reaction can in principle be carried out without a catalyst, higher temperatures or longer residence times may then have to be accepted. Catalysts for the phase interface process according to (i) are known to those skilled in the art.

[0072] If the process according to the invention is carried out according to the melt transesterification process (see (ii) and (iii)), suitable catalysts include, for example, ammonium catalysts such as tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride, tetramethylammonium tetraphenylboranate, dimethyldiphenylammonium hydroxide, tetraethylammonium hydroxide, cethyltrimethylammonium tetraphenylboranate, and cethyltrimethylammonium phenolate. Phosphonium catalysts of formula (K) are also particularly suitable. wherein R a< , R b< , R c< and R d< can be the same or different C1-C10 alkyls, C6-C14 aryls, C7-C15 arylalkyls or C5-C6 cycloalkyls, preferably methyl or C6-C14 aryls, particularly preferably methyl or phenyl, and A -< can be an anion such as hydroxide, sulfate, hydrogen sulfate, hydrogen carbonate, carbonate or a halide, preferably chloride or an alkylate or arylate of the formula -OR, wherein R can be a C6-C14 aryl, C7-C15 arylalkyl or C5-C6 cycloalkyl, preferably phenyl.

[0073] Particularly preferred catalysts are tetraphenylphosphonium chloride, tetraphenylphosphonium hydroxide, or tetraphenylphosphonium phenolate; tetraphenylphosphonium phenolate is especially preferred. The alkali metal salts or alkaline earth metal salts of these ammonium and / or phosphonium catalysts are particularly preferred.

[0074] The catalyst is preferably used in amounts of 0.0001 to 1.0 wt.%, preferably 0.001 to 0.5 wt.%, particularly preferably 0.005 to 0.3 wt.%, and most preferably 0.01 to 0.15 wt.%, based on the weight of formula (2) or (2II) (whichever is used).

[0075] The catalyst can be used alone or as a catalyst mixture and can be added in substance or as a solution, for example in water or in phenol, e.g. as a mixed crystal with phenol. It can, for example, be introduced into the reaction preferably via masterbatch with the compound of formula (2II) or added separately or additionally.

[0076] It is also preferred that the compound of formula (2II) and the polysiloxane of formula (1) are reacted in the presence of an organic or inorganic salt of a weak acid with a pKa value in the range of 3 to 7 (25 °C). This salt can also be referred to as a co-catalyst. Suitable weak acids include carboxylic acids, preferably C2-C22 carboxylic acids such as acetic acid, propanoic acid, oleic acid, stearic acid, lauric acid, benzoic acid, 4-methoxybenzoic acid, 3-methylbenzoic acid, 4-tert-butylbenzoic acid, p-tolueneacetic acid, 4-hydroxybenzoic acid and salicylic acid, partial esters of polycarboxylic acids such as monoesters of succinic acid, partial esters of phosphoric acids such as mono- or diorganic phosphoric acid esters, branched aliphatic carboxylic acids such as 2,2-dimethylpropionic acid, 2,2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid and 2-ethylhexanoic acid.

[0077] Suitable organic or inorganic salts are selected from or derived from hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate, sodium stearate, potassium stearate, lithium stearate, sodium oleate, potassium oleate, lithium oleate, sodium benzoate, potassium benzoate, lithium benzoate, disodium, dipotassium, or dilithium salts of bisphenol A. Furthermore, the salts may include calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, and the corresponding oleates. All of these salts may be used alone or in any mixtures.

[0078] Particularly preferred is the salt selected from the group consisting of alkali metal salts, alkaline earth metal salts, and phosphonium salts of carboxylic acids. In a further preferred embodiment, the organic or inorganic salt is derived from a carboxylic acid.

[0079] The organic or inorganic salts are preferably used in amounts of 0.08 to 10 ppm and most preferably in amounts of 0.1 to 5 ppm, based on the total weight of the polysiloxane and the organic or inorganic salt.

[0080] In a preferred embodiment, the organic or inorganic salt is a sodium salt, preferably a sodium salt of a carboxylic acid. It is preferably used in such an amount that the sodium content in the resulting polysiloxane-polycarbonate block cocondensate is in the range of 0.003 ppm to 0.5 ppm, based on the total weight of the polysiloxane-polycarbonate block cocondensate to be formed. Preferably, the co-catalyst is dissolved in the polysiloxane of formula (1) with a suitable solvent. The sodium content of the polysiloxane-polycarbonate block cocondensate can be determined, for example, by atomic absorption spectroscopy.

[0081] The organic or inorganic salt can be used alone or in any mixture. It can be added as a solid or in solution. In a preferred embodiment, the organic or inorganic salt is added in the form of a mixture containing the polysiloxane of formula (1) and the organic or inorganic salt.

[0082] The catalysts can be used alone or in a mixture and can be added in substance or as a solution, for example in water or in phenol.

[0083] In particular, the at least one catalyst is mixed into the compound of formula (2II) and the co-catalyst is mixed into the polysiloxane of formula (1).

[0084] The catalyst is preferably used in amounts of 0.0001 to 1.0 wt.%, preferably 0.001 to 0.5 wt.%, particularly preferably 0.005 to 0.3 wt.% and most preferably 0.01 to 0.15 wt.% based on the sum of the polysiloxane and the compound of (2) or (2II) (whichever is used).

[0085] The method according to the invention is preferably characterized in that at least 50 vol%, particularly preferably at least 60 vol%, equally preferably at least 70 vol%, equally preferably at least 75 vol%, equally preferably at least 80 vol%, and most preferably at least 90 vol% of all siloxane domains of the siloxane domain distribution of the polysiloxane-polycarbonate block cocondensate lie in a range greater than 0 to 50 nm, wherein the siloxane domain distribution is measured by atomic force microscopy. The siloxane domain distribution refers to the diameter of the siloxane domains. It is obvious to those skilled in the art that siloxane domains equal to 0 nm cannot exist. Nevertheless, evaluation programs exist that calculate a siloxane domain distribution from 0 (and not greater than 0 nm) to 50 nm. According to the invention, it is preferred that this range from 0 to 50 nm is also covered by the defined range "greater than 0 to 50 nm".Similarly, the evaluation programs exhibit ranges of 50 to 100 nm and 100 to 200 nm. An overlap of the ranges at 50 nm and 100 nm is evident in each case. However, it is apparent to those skilled in the art (similar to "0 nm") that the lower limit is preferably to be understood as greater than 50 nm or greater than 100 nm. This means that the three ranges preferably refer to ""> 0 nm to 50 nm", ""> 50 nm to 100 nm", and ""> 100 nm to 200 nm". It was found according to the invention that a very fine siloxane domain distribution was obtained. By using the special polysiloxane, the self-condensation of the polysiloxane was minimized, and thus the size of the siloxane domains was also kept small.

[0086] To determine the size of the polysiloxane domains, polymer samples are sectioned at low temperature and examined by atomic force microscopy as described in more detail below. Preferably, the parameters and method described in the example section are used. For the purposes of the present invention, the diameter of a polysiloxane domain is understood to be the diameter of the corresponding circle of equal area in the cross-section of the polysiloxane domain visible in the section.

[0087] In a further aspect of the present invention, a polysiloxane-polycarbonate block cocondensate is provided, comprising at least one Si-OC bond, characterized in that at least 50 vol%, particularly preferably at least 60 vol%, more preferably at least 70 vol%, more preferably at least 75 vol%, more preferably at least 80 vol%, and most preferably at least 90 vol% of all siloxane domains of the siloxane domain distribution of the polysiloxane-polycarbonate block cocondensate lie in a range greater than 0 to 50 nm, wherein the siloxane domain distribution is measured by atomic force microscopy. Surprisingly, it was found that by minimizing the self-condensation tendency of the polysiloxane itself, very fine siloxane domain distributions could be obtained with polysiloxanes comprising at least one Si-OC bond.This provides SiCoPCs that can be obtained from polysiloxanes, which do not require complex hydrosilylation via Pd or Pt catalysts and yet still exhibit very fine siloxane domain distributions.

[0088] In one aspect, the polysiloxane-polycarbonate block condensate according to the present invention is obtained in all embodiments and combinations of preferences according to the inventive method.

[0089] The polysiloxane-polycarbonate block cocondensate according to the present invention is preferably characterized in that the polysiloxane-polycarbonate block cocondensate comprises structures of formula (1a) wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, phenyl or C7-C12 aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6 alkyl, p is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represent an aliphatic or aromatic group, preferably methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, -CH2-CH(CH3)-phenyl, -CH2-CH2-CH2-(2-methoxy)phenyl or phenyl, n represents an average number of repeating units from 10 to 400, preferably 10 to 100, particularly preferably 15 to 50 stands for an average number of repeating units of 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5 and "..."represent the positions at which the structure of formula (1a) is incorporated into the polysiloxane-polycarbonate block cocondensate.

[0090] All the advantages relating to formula (1) are also applicable to formula (1a) in any combination. A person skilled in the art is able to establish the relationship between the polysiloxane of formula (1) and the SiCoPC comprehensively, including structures of formula (1a). This is particularly true since the structures of formula (1a) are derived from formula (1).

[0091] It is further preferred that the polysiloxane-polycarbonate block cocondensate according to the present invention comprises structures of formula (2a) where each RX is independently a divalent substituted or unsubstituted aromatic residue.

[0092] Preferably, formula (2a) is represented by formula (2A), where wherein each Z in formula (2A) independently represents a single bond, -S(=O)2-, -C(=O)-, -O-, -S-, -S(=O)-, -CH(CN)-, a linear or branched C1-C6 alkylene group, which may optionally comprise at least one carbonyl group, may optionally have at least one halogen atom and / or may optionally be interrupted by at least one heteroatom, a C2-C10 alkylidene group, which may optionally have at least one carbon-carbon double bond, may optionally have at least one carbonyl group and / or may optionally have at least one halogen atom, each R7 and R8 independently represents hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, C1-C4 alkoxy, phenyl or C7-C12 aralkyl, o1 represents the average number of repeating units and preferably 2 to 31, especially preferably 7 to 31, and "..."represent the positions at which the structure of formula (2A) is incorporated into the polysiloxane-polycarbonate block cocondensate.

[0093] The preferences of Z, R 7 and R 8 described for formula (2), (2I) and (2II) also apply to formula (2A).

[0094] The polysiloxane-polycarbonate block condensate according to the invention is particularly preferably characterized in that the structure of formula (2a) is represented by the structure of formula (2b). where m2 represents the average number of repeating units. In this case, the polycarbonate block of the SiCoPC is derived from bisphenol A. Preferably, o in form (2b) represents 7 to 31, particularly preferably 10 to 29, also particularly preferably 15 to 28, and most particularly preferably 19 to 27.

[0095] According to the invention, it was found that the proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks is high. Preferably, the proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks is higher than when a BPA-terminated polysiloxane of the same chemical structure is used under the same conditions.

[0096] Preferably the polysiloxane content of the SiCoPC according to the invention is 2 to 15 wt.%, particularly preferably 3 to 11 wt.% and most preferably 4 to 10 wt.%, wherein the polysiloxane content refers to the total weight of the polysiloxane-polycarbonate block copolymer.

[0097] Likewise, the polysiloxane-polycarbonate block cocondensate according to the present invention is preferably characterized in that the polysiloxane-polycarbonate block cocondensate has a weight-averaged molecular weight of 24,000 to 40,000 g / mol, preferably of 25,000 to 36,000 g / mol, and particularly preferably of 26,000 to 34,000 g / mol. This molecular weight is particularly preferably measured by GPC with a polycarbonate standard and detected by RI detection. The GPC method mentioned above is preferably used.

[0098] The SiCoPC according to the invention, or the SiCoPC obtained according to the inventive method, can be processed as such into molded parts of all kinds. It can also be processed with other thermoplastics and / or polymer additives to form thermoplastic molding compounds. The molding compounds and molded parts are further aspects of the present invention.

[0099] The polymer additives are preferably selected from the group consisting of flame retardants, anti-dripping agents, flame retardant synergists, smoke inhibitors, lubricants and demolding agents, nucleating agents, antistatic agents, conductivity additives, stabilizers (e.g. hydrolysis, heat aging and UV stabilizers as well as transesterification inhibitors), flow promoters, phase compatibility mediators, dyes and pigments, impact modifiers as well as fillers and reinforcing agents.

[0100] The molding compounds according to the invention are thermoplastic. They can be produced, for example, by mixing the SiCoPC and the other components in a known manner and melt compounding and melt extrusion at temperatures preferably of 200°C to 320°C in conventional equipment such as internal kneaders, extruders, and twin-screw extruders. This process is generally referred to as compounding within the scope of this application.

[0101] Molding compound is therefore understood to be the product that is obtained when the components of such a composition are melt-compounded and melt-extruded.

[0102] The molded parts made from the SiCoPC according to the invention, from the SiCoPCs obtained from the process according to the invention, or from the thermoplastic molding compounds containing the SiCoPC, can be produced, for example, by injection molding, extrusion, and blow molding. Another processing method is the production of molded parts by deep drawing from previously produced sheets or films.

[0103] The polysiloxane-polycarbonate block cocondensates and the polycarbonate compositions obtained according to the inventive process are suitable for use wherever known aromatic polycarbonates have been used to date, and where good flowability combined with improved demolding properties, high toughness at low temperatures, and improved chemical resistance are additionally required, such as for the production of large automotive exterior parts and switch boxes for outdoor use, sheets, multi-wall sheets, electrical and electronic components, and optical storage devices. Thus, the block cocondensates can be used in the IT sector for computer and multimedia housings, mobile phone casings, and in the household sector for applications such as washing machines and dishwashers, as well as in the sports sector, for example, as a material for helmets.

[0104] In another aspect of the present invention, a use of a bisphenol of formula (3) is provided, where R1 and R2 each independently represent hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, phenyl or C7-C12 aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6 alkyl, p is an integer from 4 to 7 and X represents carbon for the termination of a polysiloxane, wherein the polysiloxane has at least one Si-OC bond after reaction with the bisphenol of formula (3), for increasing the reactivity of a terminated polysiloxane with a Si-OC bond in the reaction with a bisphenol, oligocarbonate and / or polycarbonate.

[0105] It is evident to those skilled in the art that all the preferences described above with respect to R1-R4, X and p in formula (1) are also applicable to formula (3). Formula (3) is particularly preferably formula (3a). wherein each RI independently represents either hydrogen or methyl. Most preferably, each RI in formula (3a) represents methyl. In this case, it is bisphenol-TMC.

[0106] It is equally evident to the person skilled in the art that formula (3) can also be represented by formula (300), where R1 and R2 each independently represent hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, phenyl or C7-C12 aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6 alkyl, n is an integer from 4 to 7 and X represents carbon.

[0107] According to the invention, it was found that a bisphenol of formula (3) increases the reactivity of a correspondingly terminated polysiloxane in relation to BPA such that the self-condensation of the resulting polysiloxane can be minimized. This makes a SiCoPC with a fine siloxane domain distribution and an increased proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks accessible.

[0108] Therefore, another aspect of the present invention is the use of a polysiloxane of formula (1) wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, phenyl or C7-C12 aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6 alkyl, p is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represent an aliphatic or aromatic group, preferably methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, -CH2-CH(CH3)-phenyl, -CH2-CH2-CH2-(2-methoxy)phenyl or phenyl, n represents an average number of repeating units from 10 to 400, preferably 10 to 100, particularly preferably 15 to 50 and m represents an average number of repeating units of 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5. in the production of a polysiloxane-polycarbonate block cocondensate to increase the proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks, wherein the polysiloxane has at least one Si-OC bond.

[0109] Formula (1) has already been described above in further preferences, which are also applicable to the use according to the invention. Likewise, the SiCoPC according to the invention has already been described in more detail above. Surprisingly, it was found that a specially terminated polysiloxane block increases the proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks. With an increased proportion of covalent bonds between these blocks, a finer siloxane domain distribution can result. Description of the characters:

[0110] Figure 1GPC curve of example 3 using triple detection. The black curve represents the curve with UV detection. The light gray curve represents the curve with IR detection. The medium gray curve represents the curve with refractive index (RI) detection. Figure 2 GPC curve of example 4 using triple detection. The black curve represents the curve with UV detection. The light gray curve represents the curve with IR detection. The medium gray curve represents the curve with refractive index (RI) detection. Examples of implementation

[0111] The invention is described in more detail below with reference to exemplary embodiments, wherein the determination methods described here are applied to all corresponding quantities in the present invention, unless otherwise described. MVR

[0112] Unless otherwise specified, the melting volume rate (MVR) is determined according to ISO 1133 (year 2011) (at 300 °C; 1.2 kg) unless other conditions have been described. Solution viscosity

[0113] Determination of solution viscosity: The relative solution viscosity (ηrel; also referred to as eta rel) was determined in dichloromethane at a concentration of 5 g / l at 25 °C using an Ubbeloh deviscometer. Materials: Bisphenol A:

[0114] Dichlorosiloxane: Poly(dimethylsiloxane), chlorine-terminated, viscosity 20-50 cSt; molecular weight approx. 2000-4000 g / mol; CAS 67923-13-7; abcr GmbH; 76187 Karlsruhe, Germany. Pyridine: Anhydrous, 99%, CAS 110-86-1 Sigma-Aldrich, Munich, Germany. TMC-Bisphenol: 4,4'-(3,3,5-trimethylcyclohexylidene)-bisphenol, manufactured by Covestro Deutschland AG. PC-1: Linear bisphenol A polycarbonate with phenol end groups and a solution viscosity of 1.17. This polycarbonate contains no additives such as UV stabilizers, release agents, or heat stabilizers. The polycarbonate was manufactured via a melt transesterification process as described in DE 102008019503. The polycarbonate has a phenolic end group content of 0.16%. Evaluation of siloxane domain size using atomic force microscopy (AFM)

[0115] The siloxane domain size and distribution were determined using atomic force microscopy. For this purpose, the corresponding sample (in the form of a melt cake) was sectioned at low temperature (nitrogen cooling) using an ultramicrotome. A Bruker D3100 AFM microscope was used. The AFM image was acquired at room temperature (25 °C, 30% relative humidity). The "Soft Intermittent Contact Mode" or the "Tapping Mode" was used for the measurement. A "Tapping Mode Cantilever" (Nanoworld pointprobe) with a spring constant of approximately 2.8 Nm and a resonance frequency of approximately 75 kHz was used to scan the sample. The tapping force is controlled by the ratio of the setpoint amplitude to the free oscillation amplitude (amplitude of the probe tip during free oscillation in air). The sampling rate was set to 1 Hz. Phase contrast and topography images were recorded on a 2.5 µm x 2.5 µm area to capture the surface morphology.The particles or siloxane domains were automatically analyzed using Olympus SIS image analysis software (Olympus Soft Imaging Solutions GmbH, 48149 Münster, Germany) via light-dark contrast (from the phase-contrast images). The particle diameters were determined from the diameter of the corresponding circle of equal area representing the particle's longest extension.

[0116] Several phase-contrast images (number of particles greater than 200) are evaluated as described above. The image analysis software classifies the individual diameters and generates a diameter distribution. This allows for the assignment of individual D-values ​​and corresponding volume fractions. The D-value indicates the proportion of particles smaller than the specified value. For a D90 value of x, 90% of the particles are smaller than x. Furthermore, the distribution is used to determine the proportion of particles with diameters of 0–50 nm, 50–100 nm, and 100–200 nm. GPC:

[0117] Molecular weights were determined by gel permeation chromatography (GPC) using dichloromethane as the eluent. BPA polycarbonate was used as the standard. The signal from the refractive index detector was used. The corresponding method is defined under No. 2301-0257502-09D of Currenta GmbH & Co. OHG, which can be obtained from Currenta at any time. Furthermore, to interpret the GPC results, the polymer sample was detected using several detectors to evaluate both the distribution of UV-active components (bisphenols) and non-UV-active components. The UV detector was set to 254 nm and was therefore sensitive to BPA polycarbonate; a refractive index (RI) and an infrared (IR) detector were also used. The IR detector was set to 1050 cm⁻¹ and was thus sensitive to the Si-O-Si stretching vibration.This made it possible to detect both the polycarbonate-containing polymer components and the siloxane-containing polymer components simultaneously. This type of detection is also referred to as "triple detection" in the following. Example 1 (Comparative example) Production of a BPA-terminated siloxane block

[0118] A 250 ml glass flask equipped with a stirrer and dropping funnel was heated, evacuated, and vented with dry argon. 12.18 g (0.053 mol) of bisphenol A and 8.38 g (0.106 mol) of pyridine were dissolved in 100 ml of anhydrous dichloromethane under an argon atmosphere with stirring. 20 g (viscosity 20–50 cSt) of dichlorosiloxane were placed in the dropping funnel and added dropwise to the bisphenol A solution at room temperature with vigorous stirring over 50 minutes. Once the siloxane derivative was completely dissolved, the mixture was stirred for another hour.

[0119] The solution was neutralized by adding 1 M hydrochloric acid dropwise and adjusted to a slightly acidic pH (pH <4). It was then transferred to a separatory funnel and washed at least three times with demineralized water. If the solution remained distinctly acidic, washing continued until the pH was approximately neutral. The solvent was removed by rotary evaporation, leaving a suspension. The crude product was reconstituted in n-hexane, with the excess BPA remaining as a solid, and then dried and filtered through a molecular sieve (4 A). The solution was concentrated to its maximum extent at <1 mbar and 50°C for at least 0.5 h and filtered through a 5 µm Teflon filter. A colorless oil was obtained.

[0120] NMR: 1<H-NMR (Bruker AV III HD 600 MHz NMR spectrometer; CDCl 3 ): 7.06-7.10 ppm (m, 4 H), 6.78-6.81 (m, 2.18 H), 6.70-6.73 (m, 1.81 H), 1.60 ppm (s, 6.32 H), 0-0.2 ppm (m , 108.39 H).

[0121] This corresponds to an aryl-terminated siloxane according to formula (10)

[0122] With n of approximately n = 30 and m of approximately m = 1.2. Example 2 (Example according to the invention) Production of a TMC BP-terminated siloxane block

[0123] A 250 ml glass flask equipped with a stirrer and dropping funnel was heated, evacuated, and vented with dry argon. 16.56 g (0.053 mol) of TMC-bisphenol and 8.38 g (0.106 mol) of pyridine were dissolved in 100 ml of anhydrous dichloromethane under an argon atmosphere with stirring. 20 g (viscosity 20–50 cSt) of dichlorosiloxane were placed in the dropping funnel and added dropwise to the bisphenol-TMC solution at room temperature with vigorous stirring over 50 minutes. Once the siloxane derivative was completely dissolved, the mixture was stirred for another hour.

[0124] The solution was neutralized by adding 1 M hydrochloric acid dropwise and adjusted to a slightly acidic pH (pH < 4). It was then transferred to a separatory funnel and washed at least three times with demineralized water. If the solution remained distinctly acidic, washing continued until the pH was approximately neutral. The solvent was removed by rotary evaporation, leaving a suspension. The crude product was reconstituted in n-hexane, with the excess BP-TMC remaining as a solid, and then dried and filtered through a molecular sieve (4 A). The solution was concentrated to its maximum extent at < 1 mbar and 50 °C for at least 0.5 h and filtered through a 5 µm Teflon filter. A colorless oil was obtained.

[0125] NMR: 1< H-NMR (Bruker AV III HD 600 MHz NMR spectrometer; CDCl 3 ): 7.19 (m, 2.0 H), 7.0 (m, 2.09 H), 6.80 (m, 1.1 H), 6.73 (m, 2.1 H), 6.65 (m, 0.9 H), 2.61 (m, 1.0 H), 2.37 (m, 1.0 H), 2.0-1.88 (m, 2.0 H), 1.36 (m, 1.0 H), 1.14 (m, 1.0 H), 0.97 (m, 6.0 H), 0.86 (m, 1.0 H), 0.36 ppm (m, 3.0 H), 0.25-0.20 (m, 7.2H), 0.1-0.0 (m, 98.7 H).

[0126] This resulted in a polysiloxane of formula (1A) with all RI = methyl, n of approx. 30 and m of approx. = 1.2. Example 3 (Comparative example; production of Si-containing block cocondensate using a BPA-terminated siloxane according to Example 1)

[0127] In a 250 ml glass flask equipped with a stirrer, dropping funnel, and short-path separator, 47.5 g of PC-1 were placed. In the dropping funnel, 2.5 g of polydimethylsiloxane from Example 1 (5 wt%) containing approximately 2 ppm sodium (in the form of 0.036 mg sodium 2-ethylhexanoate) were placed. The apparatus was evacuated and vented with nitrogen (three times each). The PC-1 was melted in a metal bath preheated to 350 °C within 5 minutes under atmospheric pressure (under nitrogen). A vacuum was then applied. The siloxane catalyst mixture was rapidly added dropwise at 100 mbar. The pressure was then reduced to the technically feasible minimum, which should be <1 mbar, and the mixture was stirred at this pressure for 15 minutes. Afterward, the apparatus was vented with nitrogen, and the polymer melt was removed. A strongly cloudy to opaque polymer was obtained. The solution viscosity was 1.470. Example 4(Example according to the invention; production of Si-containing block cocondensate using a TMC-terminated siloxane according to Example 2)

[0128] In a 250 ml glass flask equipped with a stirrer, dropping funnel, and short-path separator, 47.5 g of PC-1 were placed. In the dropping funnel, 2.5 g of polydimethylsiloxane from Example 2 (5 wt%) containing approximately 2 ppm sodium (in the form of 0.036 mg sodium 2-ethylhexanoate) were placed. The apparatus was evacuated and vented with nitrogen (three times each). The PC-1 was melted in a metal bath preheated to 350 °C within 5 minutes under atmospheric pressure (under nitrogen). A vacuum was then applied. The siloxane catalyst mixture was rapidly added dropwise at 100 mbar. The pressure was then reduced to the technically feasible minimum, which should be <1 mbar, to approximately 1 mbar, and the mixture was stirred at this pressure for 15 minutes. Afterward, the apparatus was vented with nitrogen, and the polymer melt was removed. A slightly cloudy polymer was obtained. The solution viscosity was 1.436. AFM analysis with evaluation of the volume fraction of siloxane domains

[0129] Table 1: Volume share in the area 0-50 nm 50-100 nm 100-200nm D90 Example 3 (Comparison) 13 % 76 % 11 % 79 nm Example 4 (according to the invention) 95 % 5 % 0 % 39 nm

[0130] It is clearly evident that the distribution in the example according to the invention is finer. Elugrams (GPC analysis; acetone extract)

[0131] To determine their incorporation behavior, the respective polymers were dissolved in dichloromethane and precipitated in acetone under stirring (ratio 1 part dichloromethane solution to 10 parts acetone). The precipitated polymer was filtered off, and the mother liquor was concentrated to dryness.

[0132] A GPC with triple detection was recorded from the acetone extract (soluble fraction, mother liquor); in addition to the UV signal (black curve), the siloxane signal of the Si-O band at approximately 1050 cm -1< (light gray curve) was also detected by IR detector.

[0133] The result of Example 3 is in Figure 1 shown. The result of Example 4 is in Figure 2 shown. One can recognize by Figures 1 and 2The electrogram shows that practically two curves are detected. The black or medium-gray curve corresponds to the polycarbonate fraction that is soluble in acetone. These are primarily polycarbonate oligomers with a molecular weight between 0 and 10,000 g / mol. This fraction consists almost entirely of polycarbonate.

[0134] The light gray curve describes the proportion that mainly contains polydimethylsiloxane. In the block cocondensate according to Example 3 ( Figure 1 ) the polycarbonate content in these chains is very low (see black curve); in contrast, in the block cocondensate according to example 4 ( Figure 2 The proportion of polycarbonate in the predominantly polydimethylsiloxane-based chains is significantly higher. It can be assumed that this improves the compatibility between polydimethylsiloxane and polycarbonate.

Claims

1. Process for producing a polysiloxane-polycarbonate block co-condensate by reaction of at least one polysiloxane of formula (1) wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8-alkyl, C5-C6-cycloalkyl, phenyl or C7-C12-aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6-alkyl, p is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represents an aliphatic or an aromatic group, preferably represents methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, - CH2-CH(CH3)-phenyl, -CH2-CH2-CH2-(2-methoxy)phenyl or phenyl, n is an average number of repeating units from 10 to 400, preferably 10 to 100, particularly preferably 15 to 50 and m is an average number of repeating units from 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5, (i) with at least one compound of formula (2) and / or (2I) in the presence of at least one base and phosgene in the interfacial process, (ii) with at least one compound of formula (2) and at least one diaryl carbonate in the melt transesterification process or (iii) with at least one compound of formula (2II) and optionally at least one diaryl carbonate in the melt transesterification process, wherein wherein each Z in formula (2), (21) or (2II) is independently a single bond, -S(=O)2-, -C(=O)-, -O-, - S-, -S(=O)-, -CH(CN)- or a linear or branched C1-C6-alkylene group which may optionally comprise at least one carbonyl group, may optionally comprise at least one halogen atom and / or which may optionally be interrupted by at least one heteroatom or a C2-C10-alkylidene group which may optionally comprise at least one carbon-carbon double bond, may optionally comprise at least one carbonyl group and / or may optionally comprise at least one halogen atom, each R7 and R8 in formula (2), (2I) or (211) independently represents hydrogen, halogen, C1-C8-alkyl, C5-C6-cycloalkyl, C1-C4-alkoxy, phenyl or C7-C12-aralkyl, o in formula (2I) or (2II) represents the average number of repeating units and may be 2 to 40, preferably 7 to 31, Y in formula (2II) represents hydrogen or -(C=O)-O-Ph, wherein Ph represents an optionally substituted phenyl and Y1 in formula (2II) represents optionally substituted phenyl or a compound of formula (2IIa), wherein wherein each Z, R7 and R8 is as defined above for formula (211) and "*" represents the site at which the structure of formula (2IIa) links to formula (2II) as Y1.

2. Process according to Claim 1, characterized in that each Z in formula (2), (2I) or (2II) is independently a single bond or isopropylidene and each R7 and R8 in formula (2), (2I) or (2II) independently represents hydrogen or methoxy, preferably hydrogen.

3. Process according to Claim 1 or 2, characterized in that the polysiloxane of formula (1) is reacted (iii) with at least one compound of formula (2II) in the melt transesterification process.

4. Process according to any of Claims 1 to 3, characterized in that the compound of formula (2II) has a relative solution viscosity eta rel of 1.08 to 1.22.

5. Process according to any of Claims 1 to 4, characterized in that the reaction according to (i) to (iii) is carried out in the presence of at least one catalyst.

6. Process according to any of Claims 1 to 5, characterized in that at least 50% by volume of all siloxane domains in the siloxane domain distribution of the polysiloxane-polycarbonate block co-condensate are in a range from greater than 0 to 50 nm, wherein the siloxane domain distribution is measured by atomic force microscopy.

7. Polysiloxane-polycarbonate block co-condensate comprising at least one Si-O-C bond, characterized in that at least 50% by volume of all siloxane domains in the siloxane domain distribution of the polysiloxane-polycarbonate block co-condensate are in a range from greater than 0 to 50 nm, wherein the siloxane domain distribution is measured by atomic force microscopy.

8. Polysiloxane-polycarbonate block co-condensate according to Claim 7, characterized in that the polysiloxane-polycarbonate block co-condensate comprises structures of formula (1a) wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8-alkyl, C5-C6-cycloalkyl, phenyl or C7-C12-aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6-alkyl, p is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represents an aliphatic or an aromatic group, preferably represents methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, - CH2-CH(CH3)-phenyl, -CH2-CH2-CH2-(2-methoxy)phenyl or phenyl, n is an average number of repeating units from 10 to 400, preferably 10 to 100, particularly preferably 15 to 50, m is an average number of repeating units from 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5 and "..." represents the sites at which the structure of formula (1a) is incorporated into the polysiloxane-polycarbonate block co-condensate.

9. Polysiloxane-polycarbonate block co-condensate according to either of Claims 7 or 8, characterized in that the polysiloxane-polycarbonate block co-condensate comprises structures of formula (2a): wherein each RX is independently a divalent substituted or unsubstituted aromatic radical.

10. Polysiloxane-polycarbonate block co-condensate according to Claim 9, characterized in that the structure of formula (2a) is represented by the structure of formula (2b) wherein m2 indicates the average number of repeating units.

11. Polysiloxane-polycarbonate block co-condensate according to any of Claims 7 to 10, characterized in that the polysiloxane-polycarbonate block co-condensate has a weight-average molecular weight of 24 000 to 40 000 g / g / mol.

12. Moulding compound containing the polysiloxane-polycarbonate block co-condensate according to any of Claims 7 to 11.

13. Moulded part containing the polysiloxane-polycarbonate block co-condensate according to any of Claims 7 to 11.

14. Use of a bisphenol of formula (3) wherein R1 and R2 each independently represent hydrogen, halogen, C1-C8-alkyl, C5-C6-cycloalkyl, phenyl or C7-C12-aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6-alkyl, p is an integer from 4 to 7 and X represents carbon for terminating a polysiloxane, wherein after reaction with the bisphenol of formula (3) the polysiloxane has at least one Si-O-C bond, to increase the reactivity of a terminated polysiloxane having an Si-O-C bond in the reaction with a bisphenol, oligocarbonate and / or polycarbonate.

15. Use of a polysiloxane of formula (1) wherein each R1 and R2 independently represents hydrogen, halogen, C1-C8-alkyl, C5-C6-cycloalkyl, phenyl or C7-C12-aralkyl, R3 and R4 are individually selectable for each X and independently represent hydrogen or C1-C6-alkyl, p is an integer from 4 to 7 and X represents carbon, each R5 and R6 independently represents an aliphatic or an aromatic group, preferably represents methyl, ethyl, trimethylphenyl, -CH2-CH2-phenyl, -CH2-CH2-CH2-phenyl, - CH2-CH (CH3) -phenyl, -CH2-CH2-CH2- (2-methoxy) phenyl or phenyl, n is an average number of repeating units from 10 to 400, preferably 10 to 100, particularly preferably 15 to 50 and m is an average number of repeating units from 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5, in the production of a polysiloxane-polycarbonate block co-condensate to increase the proportion of covalent bonds between the siloxane blocks and the polycarbonate blocks, wherein the polysiloxane has at least one Si-O-C bond.