PROCESS FOR THE PREPARATION OF POLYORGANOSILOXANES WITH LOW SILANOL CONTENT

Description

[0001] The present invention relates to a process for the preparation of polyorganosiloxanes which ensures that polar Si-OC-bonded and silanol groups are reduced to a minimum and thus the polyorganosiloxanes have dielectric properties suitable for high-frequency applications. State of the art:

[0002] With the progressive development of high-frequency technology for wireless communications, the demand for materials suitable for its implementation is increasing. This affects all areas of materials, such as copper foils, binders, glass fibers, etc. Regarding binders, the epoxy resins traditionally used for the production of copper-clad laminates or, as a result, for circuit board production are no longer suitable due to their high dielectric loss factors. Polytetrafluoroethylene, which has a very low dielectric loss factor and is well-suited for high-frequency applications in this respect, has other disadvantages, particularly poor processability and poor adhesion properties, which make an alternative desirable.Polyphenylene ethers are currently being used extensively as binders for this application because they combine low dielectric loss factors with good mechanical and thermal properties and water repellency. Other organic polymers are also being considered in current development activities for this application, such as bismaleimide polymers, bismaleimide triazine copolymers, and hydrocarbon resins, although this list could be expanded to include others.

[0003] Polyorganosiloxanes generally possess excellent heat resistance, weathering stability and hydrophobicity, are flame-resistant and have low dielectric loss factors.

[0004] These property profiles qualify both the aforementioned organic polymers and the polyorganosiloxanes for use as binders in the production of high-frequency-capable copper-clad laminates and components, such as circuit boards and antennas. Therefore, it makes sense to combine the positive properties of these material classes to symbiotically enhance their performance. Corresponding experiments have already been documented in the state of the art.

[0005] Polar substituents in the polyorganosiloxanes are undesirable because they increase the dielectric loss factor. According to the state of the art, polyorganosiloxanes are preferably produced by a hydrolytic condensation process. Alcohols may also be used in this process. See, for example, combinations of polyorganosiloxanes and polyphenylene ethers to improve flame resistance are described in US Pat. No. 6,258,881. Solid polyorganosiloxanes with a specific particle size are particularly suitable for this purpose.

[0006] Further examples of the use of compositions of physical mixtures of polyphenylene ethers with polyorganosiloxanes to improve specific properties can be found in US 3737479 (improvement of impact strength), US 5834585 (mixtures of chemically curable polyphenylene ethers with improved processability), US 2004 / 0138355 (improvement of flame resistance by blends with closed and partially open silsesquioxane cage structures), US 3960985 (improvement of the thermal stability of mixtures of polyphenylene ethers with alkenyl aromatic polymers by adding small amounts of chain-connected Si-H-functional polydimethylsiloxanes).

[0007] These examples demonstrate the interest and fundamental usability of polyorganosiloxanes as additives and cobinders for high-frequency applications.

[0008] US 2016 / 0244610 describes compositions made from blends of olefinically unsaturated MQ resins with unsaturated modified polyphenylene ethers, whereby the use of the MQ resin is intended to improve the dielectric and thermal properties of the polyphenylene ethers. However, the examples in US 2016 / 0244610 exhibit quite high dielectric loss factors for the compositions according to the invention.

[0009] Since the explanation of the technological environment in US 2016 / 0244610 refers specifically to the future development of communication technology, the invention must be considered and evaluated in relation to the requirements of this environment.

[0010] Regarding the requirements and performance already achieved by current materials suitable for use in 5G applications, reference is made to US 2020 / 369855. US 2016 / 0244610 states and claims that the polyorganosiloxanes according to the invention are produced from the monomers by a hydrolytic process. For this process, alcohol is additionally used as a solvent and alkoxylated precursors as reagents.

[0011] Since US 2016 / 0244610 fails to provide an analytical description of the resulting MQ resins, reference should be made to US 5548053 as a more comprehensible prior art, which describes the synthesis of MQ resins in a hydrolytic process. The special feature of the process according to US 5548053 is that the MQ resins are produced in a two-step process, with the second step reducing the number of residual silanol groups. The other procedure is essentially comparable to the procedure in the examples according to US 2016 / 0244610.

[0012] Since the second stage of the process according to US 5548053 is not applied in US 2016 / 0244610, the effect of reducing the silanol groups as achieved in US 5548053 is also not to be expected in US 2016 / 0244610. Therefore, a higher number of silanol groups can be assumed in US 2016 / 0244610 than stated in US 5548053. Despite the targeted reduction of the silanol groups by the inventive process from US 5548053, substantial amounts of alkoxy groups remain, which are also Si-OC-bonded polar groups and prevent the achievement of a low dielectric loss factor. Since US 5548053 represents an older but nevertheless superior state of the art for the reduction of polar groups with regard to the synthesis of MQ resins, the MQ resins according to US 2016 / 0244610 have inferior properties for use in high-frequency applications with regard to the number of silicon-bonded polar groups than those available according to US 5548053.In this context, it is incomprehensible that the examples in US 2016 / 0244610 do not refer to the existing prior art US 5548053. However, as shown, in this case, in addition to residual amounts of silanol groups, alkoxy groups would also remain in the resin in large quantities.

[0013] A further weakness of the teaching according to US 2016 / 0244610 is the unsatisfactory results of the inventive compositions in the application results due to the incompatibility of the MQ resins used in the polyphenylene ether matrix. This circumstance is clearly recognized and documented in the examples, so that the problem-solving nature of the invention according to US 2016 / 0244610 is not apparent. Consequently, US 2016 / 0244610 misses its objective and reveals neither the teaching nor the benefit of the presented combinations for the field of wireless high-frequency communication technology.

[0014] What US 2016 / 0244610 demonstrates, however, is the fact that homogeneous physical compositions of silicones, in this case MQ-type silicone resins with polyphenylene ethers, are not readily possible. The selection of particularly suitable silicone resins that are both compatible, easy to process, and available in a suitable dosage form, and that allow a synergistic enhancement of the positive properties of both the organic component of the polyphenylene ether and the silicone component, presents a particular challenge. In the interest of optimal results, it is then additionally necessary to produce the polyorganosiloxanes usable according to the invention using suitable processes that minimize polar groups. Such a process is not found in either US 2016 / 0244610 or US 5548053.

[0015] In the same way as US 2016 / 0244610, US 2018 / 0220530 also describes compositions of mixtures of silicone resins, in this case of the MT, MDT, MDQ, and MTQ types, which are claimed in a general manner and as classes without further restriction. The claimed silicone resins are all produced by a hydrolytic process.

[0016] US 2018 / 0215971 teaches, in the same way as US 2016 / 0244610 and US 2018 / 0220530, compositions of mixtures of silicone resins, in this case of the TT and TQ type, which are also claimed in this case without further restriction in a general manner and as classes, with vinyl- or (meth)acrylate-functional polyphenylene ethers, it being claimed that all silicone resins according to the invention are produced by a hydrolytic process from the starting monomers.

[0017] US 2018 / 0215971 and US 2018 / 0220530, in turn, do not provide any analytical data from which it would be possible to determine the extent to which Si-OC-bonded polar groups and silanol groups are retained in the applied synthesis process.

[0018] The dielectric loss factors targeted in both inventions are < 0.007. This requirement is met with freshly produced test specimens made from the materials according to the invention, although not significantly undercut, so that the state of the art according to US 2018 / 0215971 and US 2018 / 0220530 leaves considerable room for improvement.

[0019] Considering the dielectric loss factors of the inventive solutions according to US 2018 / 0215971 and US 2018 / 0220530, it is noteworthy that the compositions according to US 2018 / 0215971 and US 2018 / 0220530 are significantly more expensive than already available prior art solutions that achieve comparable dielectric loss factors much more economically. Thus, these inventions also lack a teaching that further develops the prior art, and the realization of the inventions according to US 2016 / 0244610, US 2018 / 0215971, and US 2018 / 0220530 seems unlikely.

[0020] Document US 7,358,316 B2 relates to low-dielectric-constant materials for new electrical and electronic devices. The process disclosed in this document corresponds to the first step of the present process, whereby water and any residual acid are removed by washing and drying.

[0021] An alternative to a hydrolytic production process for the synthesis of polyorganosiloxanes is taught by US 2019359774. In this process, alkali metal siliconates, obtainable from the reaction of organosilanols or alkoxy-functional silane or siloxane precursors with alkali metal hydroxides, are reacted with chlorosilyl components in an anhydrous condensation process. The alkali metal siliconates reacted in the process according to the invention are prepared in a separate upstream synthesis step. An auxiliary base is added to the process to bind the hydrogen chloride formed during the reaction. Salt is filtered off or removed as an aqueous solution with water during workup. In this way, silanol-free and alkoxy-free linear polyorganosiloxanes are obtained.

[0022] The applicability of the synthesis to silanol-functional polyorganosiloxanes without the detour via alkali metal siliconates is not demonstrated. Furthermore, the synthesis remains limited to linear polyorganosiloxanes. Task:

[0023] The present invention is dedicated to the object of providing crosslinkable polyorganosiloxanes with dielectric properties suitable for use as binders for high-frequency applications in an anhydrous process in such a way that they are obtained economically, in particular without the detour via metal siliconates or other raw materials to be produced in a separate step, with a minimum of Si-OC-bonded polar groups and in structural diversity sufficient for the application, in particular also with a three-dimensional structure.

[0024] This includes the fact that, as a pure binder, they have a dielectric loss factor of not more than 0.0040 at 10 GHz, that they well wet any fillers that may be present that reduce the dielectric loss factor, that they allow the production of tack-free prepregs and that they produce preparations that are compatible with organic polymers.

[0025] The invention relates to a process for the preparation of polyorganosiloxanes of the formula (I) [O 3-a / 2 R a SiY(SiR a O 3-a / 2 ) b ] c (R 1< SiO 3 / 2 ) d (R 2< 2 SiO 2 / 2 ) e (R 3< 3 SiO 1 / 2 ) f (SiO 4 / 2 ) g [O 3-h / 2 R 4< h Si(SiR 5< 2 ) i SiR 4< j O 3-j / 2 ] k (I) where the radicals R can be identical or different radicals and represent either a hydrogen radical or a monovalent Si-C bonded, unsubstituted or heteroatom-substituted organic hydrocarbon radical having 1 to 18 C atoms, which may also be an unsaturated hydrocarbon radical, Y represents a chemical bond, an oxygen atom or a divalent to twelve-valent organic unsubstituted or heteroatom-substituted organic radical having 1 to 24 C atoms, which is bonded to the silicon atoms by Si-C linkage, the radicals R 1< , R 2< and R 3< independently of one another represent a hydrogen radical or a saturated or unsaturated Si-C bonded C1 - C18 hydrocarbon radical, which may be unsubstituted or substituted by heteroatoms or a C1 - C12 hydrocarbon radical bonded via an oxygen atom, which may contain heteroatoms, or a silanol radical, where the radicals R 1< ,R 2< and R 3< can each assume their meaning independently of one another, so that several radicals R 1< , R 2< or R 3< which are bonded to the same silicon atom can denote different radicals from the defined group, the radicals R 4< independently of one another denote either a hydrogen radical, a silanol radical or a monovalent Si-C or Si-OC-bonded, unsubstituted or heteroatom-substituted organic hydrocarbon radical having 1 to 18 C atoms, which can also be an unsaturated hydrocarbon radical, the radicals R 5< independently of one another denote either a hydrogen radical, a monovalent Si-C-bonded, unsubstituted or heteroatom-substituted organic hydrocarbon radical having 1 to 18 C atoms, which can also be an unsaturated hydrocarbon radical, or a radical of the formula (II) [O 3-a / 2 R a SiY(SiR a O 3-a / 2 ) b ] c (R 1< SiO 3 / 2 ) d (R 2< 2 SiO 2 / 2 ) e (R 3< 3 SiO 1 / 2 ) f (SiO 4 / 2 ) g (II),where, based on all radicals Y, R, R 1< , R 2< , R 3< R 4< and R 5< as 100 mol-%, at least 0.1 mol-%, preferably at least 3 mol-%, particularly preferably at least 5 mol-%, in particular at least 7 mol-% must be olefinically or acetylenically unsaturated radicals, based on all radicals Y, R, R 1< , R 2< , R 3< R 4< and R 3< as 100 wt-% in total at most 3 wt-%, preferably at most 2.5 wt-%, in particular at most 2 wt-% are Si-OC-bonded radicals and silanol radicals, and based on all radicals Y, R, R 1< , R 2< , R 3< R 4< and R 5< as 100 wt-% in total at most 0.5 wt-%, preferably at most 0.2 wt.%, in particular at most 0.1 wt.% are silanol residues, a is 0, 1 or 2, where the indices a on both sides of the group Y can assume their meaning independently of one another, so that different a can independently denote different values ​​within the stated range of values, b is a number with a value of 1 to 11, preferably 1,c has a value from 0 to 0.9, d has a value from 0 to 0.8, e has a value from 0 to 0.5, f has a value from 0.01 to 0.6, g has a value from 0 to 0.6, h and j are independently 0, 1 or 2, i is an integer with a value from 0 to 50 and k has a value from 0 to 0.9, where c+d+e+f+g+k = 1, at least one value c, d or k is > 0 and e+g ≤ 0.6, preferably < 0.5, in particular < 0.4, where the radicals R, R 1< , R 2< , R 3< , R 4< and R 5< and the indices a, b, c, d, e, f, g, h and i in formula (I) and in formula (II) independently have the same meanings and these within the described value ranges can assume independently of each other, in which in a first step silanes of the formula (III) R 6< 1 SiR 7< 4-1 (III), where R 7< is a hydrolyzable group, l is an integer of value 0, 1 or 2 and R 6< for l = 1 is a radical R 1< and for l = 2 is a radical R 2<, and / or di-,Oligo- or polysilanes of the formula (IV) R 7< 3-h R 4< h Si(SiR 5< 2 ) i SiR 4< j R 7< 3-j (IV), where R 7< is a hydrolyzable group as described above and R 4< , R 5< , h, i and j have the same meanings as mentioned above, and / or organyl-bridged silicones of the formula (V) R 7< 3-a R a SiY(SiR a R 7< 3-a ) b (V), where R 7< , R, Y, a and b have the meaning already mentioned, with water and if at least one of the hydrolyzable radicals R 7< is not a halogen radical, using catalytic amounts of one or more acids which promote the hydrolysis and condensation of the components according to the formulas (III), (IV) and (V) in the presence of a water-immiscible, aprotic solvent which is in particular not an alcohol and also contains no alcohol, whereby after the reaction both the water and the remaining acid quantity in the organic phase are reduced to the technically necessary minimum,in particular to less than 10,000 ppm each, preferably less than 5,000 ppm each, in particular less than 2,000 ppm each, so that they are optionally present only as an undesirable impurity and in a second step, the reaction product from the first step dissolved in the inert organic solvent without water is reacted with a halosilane of the formula (VI) R 3< 3 SiR 8< (VI), where R 3< has the same meanings as given above and R 8< is a halogen atom, preferably a chlorine atom, in the presence of an auxiliary base, wherein basic metal salts and nitrogen compounds are preferably used as auxiliary bases.

[0026] Surprisingly, it has been found that the stated object is achieved by the process for preparing the polyorganosiloxanes of formula (I), which consists of two steps, the first step being a hydrolytic condensation and, in the second step, the silanol groups present from the first step being reduced by anhydrous condensation, so that the polyorganosiloxane compositions are obtained without the use of metal siliconate intermediates and in a non-hydrolytic process.

[0027] The polyorganosiloxanes of formula (I) obtained by the process according to the invention are characterized in that they are substantially free of silanol groups and silicon-bonded alkoxy groups.

[0028] Alkoxy groups, especially those with short alkyl groups and silanol groups, lead to higher dielectric loss factors and also contribute to increasing the dielectric loss factor by forming points of attack for moisture.

[0029] Polyorganosiloxanes of formula (I) in the context of the present invention include both polymeric and oligomeric organosiloxanes.

[0030] In particular, structures of the formulas (Ia), (Ib) and (Ic) are also included, [O 3-a / 2 R a SiY(SiR a O 3-a / 2 ) b ] c (R 3< 3 SiO 1 / 2 ) f (Ia), (R 3< 3 SiO 1 / 2 ) f [O 3-h / 2 R 4< h Si(SiR 5< 2 ) i SiR 4< j O 3-j / 2 ] k (Ib) [O 3-a / 2 R a SiY(SiR a O 3-a / 2 ) b ] c (R 3< 3 SiO 1 / 2 ) f [O 3-h / 2 R 4< h Si(SiR 5< 2 ) i SiR 4< j O 3-j / 2 ] k (Ic) where in (Ia) d, e, g and k are each 0, in (Ib) c, d, e, and g are each 0, and in (Ic) d, e, and g are each 0. In these structures, the proportion of Si-O units is most reduced in favor of Si-C and Si-Si units.

[0031] Since the electronegativity difference between silicon and oxygen, according to the Allred and Rochow electronegativity scale, is 1.76 µm, which is greater than the electronegativity difference between silicon and carbon according to the same table, the Si-C bond has a lower polarity than the Si-O bond. It is therefore expected that replacing Si-O bonds with Si-C bonds will further contribute to reducing the overall polarity of organopolysiloxanes and thus contribute to reducing the dielectric loss factor of the corresponding components. This effect is more pronounced the more Si-O bonds can be replaced by Si-C or Si-Si bonds.The reduction of polarity in the organopolysiloxane framework, for example by introducing Si-C or Si-Si bonds instead of Si-O bonds, thus makes a significant contribution to the broad applicability of such organopolysiloxanes and is the most preferred embodiment of the invention.

[0032] Since the units of the form (R 3< 3 SiO 1 / 2 ) are used to reduce the silanol groups remaining after hydrolysis in the anhydrous second step, these groups are always present. In the nomenclature that classifies silicone building blocks according to M, D, T and Q units, depending on how many oxygen atoms a silicon atom is bonded to other silicon atoms, and according to the same, an M unit is a unit of the formula R 3 SiO 1 / 2, a D unit has the formula R 2 SiO 2 / 2, a T unit is R 1 SiO 3 / 2 and a Q unit is SiO 4 / 2, the polyorganosiloxanes according to the invention are, in the broadest sense, combinations of T, D and Q units with M units, i.e. M, MD, MT, MDT, MDTQ, MTQ and MDQ resins, whereby no distinction is made here between M, D and T units of different compositions.An M resin consisting of various M units can be understood from formula (Ia) if the value 2 is assumed for all a and Y is either a chemical bond or a Si-C-bonded bridging radical. Each silicon atom of the bridged unit is then surrounded only by one oxygen atom, which maintains a bond to a neighboring silicon atom and can therefore be understood, in the sense of the general M, D, T, Q nomenclature, as an M 2 building block in which two M units are bonded to one another or coupled by a bridging radical. This structural peculiarity of chain-forming M units, both from the organically bridged and the di-, oligo-, or polysilane units, must be taken into account in this case.

[0033] Simple M units, such as those corresponding to the synthesis equivalents for the units of the formula (R 3 SiO 1 / 2 ) f and as used in US 20180220530, are not used in the first step of the synthesis, the hydrolytic reaction step. Although this is possible in principle, it does not have the same effect on reducing the silanol groups as the use of these groups in the second anhydrous synthesis step. The units of the formula (R 3 SiO 1 / 2 ) f are therefore only used in the second anhydrous reaction step in order to reduce the number of silanol groups and thereby achieve an improvement over the prior art according to US 20180220530. This is an essential distinguishing feature of the inventive procedure.In US 20180220530, all building blocks forming the polyorganosiloxanes according to the invention are reacted with one another in a single hydrolytic step, whereby there is no possibility of further reducing the silanol groups formed during the condensation and thus further improving the binders for the target application of binders for high-frequency applications. The fact that silanol groups are inevitably bound to the polyorganosiloxane framework after a hydrolytic condensation is not taken into account in US 20180220530, which is easily recognizable from the fact that a relevant meaningful analytical description of the polyorganosiloxanes according to the invention is completely omitted.Apparently, the inventors have not grasped the significance of the precise composition of the polyorganosiloxanes according to US 20180220530 and the structure-activity relationships and starting points for improvements that can be explained thereby, if they consider these to be so insignificant that they do not disclose them as relevant to the invention.

[0034] Since the possibility of using Si-Si-bonded or Si-C-bridged units in order to reduce the proportion of polar bonds in the polyorganosiloxane framework is also dispensed with, the present invention results in a further improvement over the prior art according to US 20180220530.

[0035] In structures (Ia), (Ib) and (Ic) the proportion of Si-C bonded bridging organic residues, or Si-Si bonds, which are naturally also non-polar, is particularly high and the structure is practically only completed by the terminating units (R 3< 3 SiO 1 / 2 ) f.

[0036] Examples of R, R 1< , R 2< , R 3< , R 4< and radicals R 5< with the exception of the radicals R 5< , which are radicals of the formula (II), are saturated or unsaturated hydrocarbon radicals which may contain aromatic or aliphatic double bonds, for example alkyl radicals such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, isopentyl, neo-pentyl and tert.- Pentyl radical, hexyl radicals such as the n-hexyl radical, heptyl radicals such as the n-heptyl radical, octyl radicals such as the n-octyl radical and iso-octyl radicals such as the 2, 2, 4-trimethylpentyl and the 2-ethylhexyl radical, nonyl radicals such as the n-nonyl radical, decyl radicals such as the n-decyl radical, dodecyl radicals such as the n-dodecyl radical, tetradecyl radicals such as the n-tetradecyl radical, hexadecyl radicals such as the n-hexadecyl radical and octadecyl radicals such as the n-octadecyl radical, cycloalkyl radicals such as cyclopentyl, cyclohexyl and 4-ethylcyclohexyl radical, cycloheptyl radicals, norbornyl radicals and methylcyclohexyl radicals, aryl radicals, such as the phenyl, biphenyl, naphthyl, anthryl, and phenanthryl radicals; alkaryl radicals, such as o-, m-, p-tolyl radicals, xylyl radicals, and ethylphenyl radicals; aralkyl radicals, such as the benzyl radical, alkenyl radicals, such as the 7-octenyl, 5-hexenyl, 3-butenyl, allyl, and vinyl radicals, as well as the alpha- and β-phenylethyl radicals.

[0037] Preferred heteroatoms that may be contained in the radicals R, R 1< , R 2< , R 3< , R 4< and R 5< are oxygen atoms.

[0038] In addition, nitrogen atoms, phosphorus atoms, sulfur atoms and halogen atoms such as chlorine atoms and fluorine atoms are also possible, but not preferred.

[0039] Examples of preferred organic radicals R, R 1< , R 2< , R 3< , R 4< , and R 5< containing heteroatoms are radicals containing acryloyloxy or methacryloyloxy radicals of acrylic acid or methacrylic acid, as well as acrylic acid esters or methacrylic acid esters of unbranched or branched alcohols having 1 to 15 carbon atoms. Preferred such radicals are those derived from methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, and norbornyl acrylate. Particularly preferred are methyl acrylate, methyl methacrylate, n-butyl acrylate, iso-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, and norbornyl acrylate.These radicals are preferably not directly bonded to the silicon atom, but are bonded via a hydrocarbon spacer, which may comprise 1 to 12 carbon atoms, preferably comprising 1 or 3 carbon atoms and containing no further heteroatoms apart from the heteroatoms contained in the acryloyloxy or methacryloyloxy radical. The radicals R, R 1< , R 2< , R 3< , R 4< , and R 5< are preferably selected from methyl, phenyl, vinyl, acryloyloxy, and methacryloyloxy radicals, as well as the acrylic acid esters or methacrylic acid esters of unbranched or branched alcohols having 1 to 15 carbon atoms.

[0040] Further preferred radicals R, R1, R2 and R3 comprising heteroatoms are those of the formula (VII).

[0041] In formula (VII), R 9< , R 10< , R 11< , R 12< , R 13< and R 14< independently of one another represent a hydrogen radical, a hydrocarbon group or a hydrocarbon group substituted by foreign atoms, where at least one of the radicals R 9< , R 10< , R 11< , R 12< , R 13< and R 14< always represents a hydrocarbon group which is bonded to the silicon atom via a Si-C or a Si-OC bond, where it is preferred that this hydrocarbon group, via which the radical of formula (VII) is bonded to a silicon atom, is a C3 hydrocarbon group which does not contain any heteroatoms. Alternatively, the radical R 9< , R 10< , R 11< , R 12< , R 13< and R 14< can also be a chemical bond, so that the radical of the formula (II) is directly bonded to the silicon atom via this radical, which represents a chemical bond, via a Si-C bond.

[0042] Examples of radicals R 9< , R 10< , R 11< , R 12< , R 13< and R 14< are the hydrogen radical, saturated hydrocarbon radicals such as methyl, ethyl, n-propyl, iso-propyl, the primary, secondary and tertiary butyl radical, the hydroxyethyl radical, aromatic radicals such as the phenylethyl radical, the phenyl radical, the benzyl radical, the methylphenyl radical, the dimethylphenyl radical, the ethylphenyl radical, heteroatom-containing radicals such as the hydroxymethyl radical, the carboxyethyl radical, the methoxycarbonylethyl radical and the cyanoethyl radical and acrylate and methacrylate radicals such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, t-Butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate and norbornyl acrylate, olefinically or acetylenically unsaturated hydrocarbon residues.

[0043] Optionally, the adjacent radicals R 9< and R 11< as well as the adjacent radicals R 10< and R 12< can also be linked to one another to form the same cyclic saturated or unsaturated radical, so that fused polycyclic structures are formed.

[0044] Examples of phenol radicals of the formula (VII) are the phenol radical, the ortho-, meta- or para-cresol radical, 2,6-, 2,5-, 2,4- or 3,5-dimethylphenol radical, 2-methyl-6-phenylphenol radical, 2,6-diphenylphenol radical, 2,6-diethylphenol radical, 2-methyl-6-ethylphenol radical, 2,3, 5-, 2,3,6- or 2,4,6-trimethylphenol radical, 3-methyl-6-tertiary-butylphenol radical, thymol radical and 2-methyl-6-allylphenol radical, which may optionally be substituted on the oxygen atom.

[0045] Preferred examples of fluorine-containing radicals are the trifluoropropyl, nonafluorohexyl and heptadecafluorooctyl radicals.

[0046] Y is preferably a linking organic unit with 1 to 24 carbon atoms between two to twelve siloxanyl units. Y is preferably divalent, trivalent, or tetravalent, especially divalent.

[0047] Preferred bridging aromatic radicals Y are those of the formula (VIIIa), (VIIIb) and (VIIIc) where the radicals R 15< , R 16< , R 17< and R 18< may represent a hydrogen radical or an optionally substituted hydrocarbon radical or a group of the formula OR 19< where R 19< represents a hydrocarbon radical. Adjacent radicals such as, for example, R 15< and R 17< or R 16< and R 18< in formula (VIIIa) may be coupled to one another to form cyclic radicals, thus forming fused ring systems.

[0048] Typical examples of such bridging aromatic radicals are the p-, m- or o-phenylene radical, the 2-methyl-1,4-phenylene radical, the 2-methoxy-1,4-phenylene radical, with the p-phenylene radical being particularly preferred.

[0049] Several such radicals can also be coupled together, so that, for example, two or more units of formula (IIIa) are coupled together, and this oligomeric bridging structural element is present by bonding the corresponding carbon atoms of the terminal aromatic rings to the silicon atom. The aromatic units can be directly bonded to one another or they can be coupled to one another by a bridging group such as an alkanediyl unit, such as a methylene group, a 1,2-ethanediyl group, a 1,1-ethanediyl group, a 2,2-dimethylpropyl group, or a sulfone group.

[0050] Further examples of aromatic bridging units are those in which two optionally substituted phenol rings are bridged via an alkanediyl or other unit. Typical representatives are 2,2-bis(4-hydroxyphenyl)propane residues substituted on the phenol oxygen (substituted bisphenol A residues), 2,2-bis(4-hydroxyphenyl)methane residues (substituted bisphenol F residues), and bis(4-hydroxyphenyl)sulfone residues (bisphenol S residues), where the phenol oxygen atoms are typically substituted with residues of the type -(C3H6)-, where the -(C3H6)- residues are bonded to silicon atoms Si-C, thereby forming the bridge.

[0051] Preferred Y radicals not bridged by an aromatic unit are alkanediyl, alkenediyl and alkynediyl radicals, which may optionally contain heteroatoms and which may contain aromatic groups as substituents, but which do not take over or contribute to the bridging function in these radicals.

[0052] Typical examples are the methylene radical, the methine radical, the tetravalent carbon, the 1,1-ethanediyl and the 1,2-ethanediyl group, the 1,4-butanediyl and the 1,3-butanediyl group, the 1,5-pentanediyl, 1,6-hexanediyl, 1,7-heptanediyl, 1,8-octanediyl, 1,9-nonadiyl, 1,10-decanediyl, 1,11-undecanediyl and the 1,12-dodecanediyl group, the 1,2-diphenylethanediyl group, the 1,2-phenylethanediyl group and the 1,2-cyclohexylethanediyl group. If a linear bridging unit has more than one carbon atom and the substitution pattern allows it, each of these groups can act as a bridge not only through alpha-omega connectivity, i.e. bridging through the first and last atom of a linear unit, but also through any other connectivity, i.e. the use of other chain carbon atoms.In addition, typical examples are not only the linear representatives of the bridging hydrocarbons mentioned, but also their isomers, which in turn can have a bridging effect by binding different C atoms of the hydrocarbon structure to silicon atoms.

[0053] Examples of particularly preferred radicals from the group of non-aromatic heteroatom-free hydrocarbon radicals are -CH 2 CH 2 -, -CH(CH 3 )-, -CH=CH-, -C(=CH 2 )- and -C≡C-.

[0054] Examples of typical fluorine-substituted bridging radicals Y are the -C(CF 3 ) 2 -, the -C(H)FC(H)F- and the -C(F 2 )-C(F 2 )- radical.

[0055] Examples of typical heteroatom-containing bridging radicals include the ethyleneoxypropylene radical and the ethyleneoxybutylene radical. Also typical are glycol radicals or phenylene ether radicals that are terminated on both sides with -(CH 2 ) n - or -CH 2 -CH(R 15< )-C(=O)O, where n is typically 3 to 8 and R 15< is a hydrogen atom or a methyl group, and bonded to the silicon atoms via this terminal group.

[0056] All lists are to be understood as examples only and not as limiting.

[0057] The organopolysiloxanes used according to the invention can vary in viscosity over a wide range depending on the average number of structural units per molecule forming them or can also be solids.

[0058] Liquid organopolysiloxanes which can be used according to the invention have viscosities of 20 to 8,000,000 mPas, preferably 20 to 5,000,000 mPas, in particular 20 to 3,000,000 mPas in the uncrosslinked state at 25°C.

[0059] Solid organopolysiloxanes usable according to the invention have glass transition temperatures in the uncrosslinked state in the range from 25°C to 250°C, preferably from 30°C to 230°C, in particular from 30°C to 200°C. Organopolysiloxanes that contain bridging phenylene units and that have a total aromatic content of at least 20 mol%, based on all Si-C-bonded substituents, have proven particularly suitable. Phenylene units are understood to include both monomeric and oligomeric, as well as substituted and unsubstituted phenylene units, as illustrated in the examples for the type of bridging substituents of this type.

[0060] Selected examples of radicals R 5< of formula (II) are linear and cyclic structures of the average composition 2 [(H)(Me) 2 SiO 1 / 2 ] 3 , [O 2 / 2 MeSi-CH 2 -CH 2 -SiMeO 2 / 2 ][(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 3 , [O 2 / 2 MeSi-CH 2 -CH 2 -SiMeO 2 / 2 ] 2 [(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 5 , [O 2 / 2 MeSi-CH 2 -CH 2 -SiMeO 2 / 2 ] 2 [(H)(Me) 2 SiO 1 / 2 ] 5 , [O 2 / 2 PhSi-C 6 H 4 -SiPhO 2 / 2 ][(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 3 , [O 2 / 2 PhSi-C 6 H 4 -SiPhO 2 / 2 ][(H)(Me) 2 SiO 1 / 2 ] 3 , [O 2 / 2 PhSi-C 6 H 4 -SiPhO 2 / 2 ] 2 [(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 5 , [O 2 / 2 PhSi-C 6 H 4 -SiPhO 2 / 2 ] 2 [(H)(Me) 2 SiO 1 / 2 ] 5 . 3 , [O 2 / 2 MeSi-C 6 H 4 -SiMeO 2 / 2 ][(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 3 , [O 2 / 2 MeSi-C 6 H 4 -SiMeO 2 / 2 ][(H)(Me) 2 SiO 1 / 2 ] 3 , [O 2 / 2 MeSi-CH 2 -CH 2 -SiMeMe 2 O 1 / 2 ] 8 [(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 9 , [O 2 / 2 MeSi-CH 2 -CH 2 -SiMeO 2 / 2 ] 8 [(CH 2 =CH)(Me) 2 SiO 1 / 2 ] 8 [(H)(Me) 2 SiO 1 / 2 ] 9 , (CH 2 =CH)(Me)2SiO 1 / 2 , (H) (Me) 2SiO 1 / 2 , (CH 3 -CH(=CH2)C(=O)O-CH 2 CH 2 CH 2 )(Me) 2 SiO 1 / 2 , (Me) 3 SiO 1 / 2 , (CH 2 =CH) 3 SiO 1 / 2 , (CH 2 =CH)Ph 2 SiO 1 / 2 .

[0061] Examples of preferred hydrolyzable radicals R 7< and R 8< are a halogen, acid or alkoxy group, particularly preferably a chlorine, acetate, formate, methoxy or ethoxy group.

[0062] The compounds (VI) are obtained by state-of-the-art processes, whereby the reaction types to be used depend heavily on the composition of the respective compound (VI). Typically, compounds (VI) are obtained, for example, from olefinically unsaturated organic precursors, such as acetylene, diallyl or divinyl compounds, and Si-H-functional silicone building blocks by hydrosilylation.

[0063] Grignard reactions from halogenated organic precursors and subsequent reaction with halogenated or alkoxylated organosilanes are also conceivable processes. Metal halide exchange reactions of halogenated organic precursors with alkyl alkali metal compounds, such as butyllithium, and known subsequent reactions for linking with silicone building blocks can also be used. Such processes are known to the person skilled in the art and are easily accessible and understandable from the available literature. Since these processes are not the subject of the invention, only a reference to the documented and searchable prior art is provided here.

[0064] The first process step, cohydrolysis, is preferably carried out by dosing a mixture of the compounds (III), (IV), (V) and (VI), as used, with cooling into water or dilute acids. In the case of gaseous acids such as HCl, dosing into a concentrated aqueous HCl solution is also useful if the acid released is to be recovered as a gas. Depending on the nature of the hydrolyzable groups R 7<, the hydrolysis is more or less exothermic, so that cooling is necessary both in the interest of safe execution of the reactions and, where appropriate, to avoid side reactions in corresponding synthesis sequences. To complete the reactions, however, it may be advantageous and necessary to use elevated temperatures.

[0065] Reaction times are generally very short in the case of chlorosilanes, so the time required to carry out the process in batch mode depends primarily on the cooling capacity. Alternatively, the cohydrolysis of (III), (IV), and / or (V) can also be carried out continuously, for which loop, column, and tubular reactors are suitable.

[0066] To remove residual acids, good washing with water, clean phase separation and purification of the hydrolysis product under reduced pressure are advantageous.

[0067] The process can be carried out at atmospheric pressure. However, depending on the objective, higher or lower pressure is also practical. It is essential that at the end of the first process step the amount of water present is reduced to such an extent that at most residual amounts of water remain which, as unintentional contaminants, cannot be further removed using state-of-the-art methods. Ideally, the remaining amount of residual water is reduced to such an extent that it is below the detection limit, so that an anhydrous medium can be assumed. This depletion of water is necessary for the successful implementation of the process according to the invention because water fundamentally has the option of forming silanol groups, provided that conditions exist under which polyorganosiloxanes can react with water, i.e. usually acidic or basic conditions.Since the goal is to remove silanol groups, the presence of water in the next step is detrimental. In the following text, the water-depleted reaction mixture from the first step is referred to as anhydrous.

[0068] The second process step is carried out using the water-free reaction mixture from the first step. The silanol groups on the polyorganosiloxane from the first step are reacted with silanes of formula (VI), optionally by metering them in dissolved in an inert solvent. To initiate and accelerate the reaction, an auxiliary base is advantageously used. In principle, the reaction between the silanol groups and the silanes of formula (VI) is also possible without an auxiliary base; however, the reaction rate is then so low that the reaction on an industrial scale would be uneconomical due to the long reaction time or would lead to low conversions. The radical R 8< represents a halogen radical, in particular a chloride radical.

[0069] Suitable auxiliary bases for capturing the hydrogen halide formed include basic salts or nitrogen-containing compounds such as amines, ureas, imines, guanidines, and amides. Examples of basic salts are sodium hydride, sodium amide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, calcium bicarbonate, calcium oxide, magnesium oxide, and magnesium carbonate. Examples of nitrogen-containing compounds are ammonia, ethylamine, butylamine, triethylamine, trimethylamine, tributylamine, N,N-dimethyldecylamine, triisooctylamine, urea, tetramethylurea, guanidine, tetramethylguanidine, N-methylimidazole, N-ethylimidazole, piperidine, pyridine, picoline, and N-methylmorpholine. Amine compounds in which the nitrogen atoms do not carry hydrogen atoms are preferably used.

[0070] The auxiliary base is preferably used in at least equimolar amounts with respect to the halosilane. At least 0.5, more preferably at least 1.0, in particular at least 2.0 base equivalents of auxiliary base are used per mole equivalent of halosilane. Larger additional amounts of auxiliary base can also be used, e.g. if it is to serve simultaneously as a solvent. In most cases, however, this does not provide any advantage but rather reduces the space-time yield and thus the economics of the process. The halosilane is preferably added to the anhydrous reaction mixture from the first step of the process and the auxiliary base is then metered in. If desired, this procedure can also be reversed, so that the auxiliary base is first added to the reaction mixture from the first synthesis step and the halosilane is then metered in.

[0071] Mixtures of several auxiliary bases can also be used.

[0072] Preferably, the halosilanes of formula (VI) are used in such a way that an equimolar amount of halide residues is present to the silanol residues on the polyorganosiloxane species from the first reaction step.

[0073] The reaction of the halosilanes of formula (VI) with the silanol radicals of the polyorganosiloxane species from the first reaction step is preferably carried out at a temperature of at least -20°C, particularly preferably at least 0°C, in particular at least 10°C. The maximum permissible temperature also results from the boiling point of the solvent used and of the halosilanes of formula (VI), with the reaction temperature preferably not exceeding 200°C, particularly preferably 175°C, in particular 150°C.

[0074] The reaction mixture can be cooled or heated as required; if necessary, individual reaction components can be adjusted to temperature beforehand before they are reacted with one another, e.g. to utilize the heat of reaction. The process can be carried out batchwise in stirred reactors or continuously in column, loop, fluidized bed or tubular reactors. Any low molecular weight siloxanes formed during the reaction can be separated from the reaction mixture by distillation if required. The halide salts formed during the reaction can be decanted, filtered off or centrifuged off, or dissolved in water and separated off. For aqueous work-up, the amount of solvent present can be adjusted as required, e.g. to facilitate phase separation by adjusting density differences, or further solvents can be added whose solubility orMiscibility with water is as low as possible, in particular a maximum of 5 wt% at 25°C.

[0075] Any excess halosilane of formula (VI) is preferably removed by distillation prior to the aqueous workup. This prevents the presence of an aqueous acidic solution, which could potentially lead to the formation of silanol groups on the polyorganosiloxane.

[0076] The second reaction step is preferably carried out under exclusion of moisture, i.e. in a dried atmosphere or under reduced pressure, particularly preferably under inert gas such as argon, nitrogen, carbon dioxide or lean air, preferably at 900 to 1100 hPa.

[0077] Particularly suitable aprotic solvents for both the first and second steps are aromatic hydrocarbon solvents such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, or mixtures thereof. Depending on the selected radicals, aliphatic or cycloaliphatic solvents, as well as linear or cyclic ethers, can also be used. The suitability of the solvent depends on its solubility for the resulting polyorganosiloxanes. The solvent must dissolve the resulting polyorganosiloxane sufficiently well, must not be miscible with water, i.e., it must not be able to dissolve more than 5 wt.% water itself, and must not participate in the reaction.

[0078] If necessary, the suitability of the solvent should be determined through appropriate experiments. Aromatic solvents best meet the above conditions and are therefore preferred.

[0079] It should be noted at this point that the use of disiloxanes, which are typically used as symmetrical disiloxanes, to reduce the number of silanol groups is not excluded by the invention. Although disiloxanes cleave in the presence of acids by breaking the Si-O-Si bond, the acids are typically used as an aqueous preparation, which would intentionally introduce water into the second step of the synthesis. The tendency to regenerate silanol groups cannot be ruled out, and the second step would no longer be anhydrous, reducing its efficiency.

[0080] The polyorganosiloxanes of formula (I) are chemically curable, meaning they can be cured by a chemical reaction to form a crosslinked, insoluble network. Curing occurs via the olefinically unsaturated groups described above. Typically, either a radical polymerization reaction is used for curing or, if silicon-bonded hydrogen is present as a residue in addition to the olefinically or acetylenically unsaturated functional groups, a hydrosilylation cure.

[0081] The polyorganosiloxanes of formula (I) all possess olefinic functional groups, through which they can be chemically crosslinked. Possible chemical crosslinking reactions include the known reactions according to the state of the art, in particular radical crosslinking, which can be initiated using suitable radiation sources such as UV light or by unstable chemical compounds that decompose into radicals. Addition crosslinking is carried out, for example, by hydrosilylation of the olefinically unsaturated group with an Si-H function in the presence of a suitable hydrosilylation catalyst.

[0082] In order to achieve sufficient curing, a sufficient amount of functional groups must be present. At least an average of 1.0 functional groups must be present per polyorganosiloxane molecule used according to the invention in order to achieve sufficient curing; preferably an average of at least 1.1, in particular an average of at least 1.2 functional groups are present per polyorganosiloxane molecule according to the invention. The functional groups can be different, so that, for example, some of the functional groups are an Si-H group and another part of the functional groups represent an olefinically unsaturated group that is radically curable or hydrosilylatable. Other combinations of complementary functional groups are also conceivable, where complementary means that the selected combinations of functional groups can react with one another.If only one type of functional group is present, for example, only olefinically or acetylenically unsaturated functional groups that are radically curable, the corresponding number of these functional groups must be present. For copolymerization to form a homogeneous matrix, it is important to ensure sufficient copolymerizability of the selected olefinic and acetylenic groups. The combination of olefinic groups that are not copolymerizable with each other is also possible, provided the resulting matrix of two or more individual polymers remains compatible with each other and does not form separate phases that separate into distinct domains.

[0083] Examples of suitable initiators for starting radical polymerization include, in particular, examples from the field of organic peroxides, such as di-tert-butyl peroxide, dilauryl peroxide, dibenzoyl peroxide, dicumyl peroxide, cumyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl cumyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, 1,1-ditert-butylperoxycyclohexane, 2,2-di(tert-butylperoxy)butane, bis(4-tert-butylcyclohexyl)peroxydicarbonate, hexadecyl peroxydicarbonate, tetradecyl peroxydicarbonate, dibenzyl peroxydicarbonate, Diisopropylbenzene dihydroperoxide, [1,3-phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, dicetyl peroxydicarbonate, acetylacetone peroxide, acetylcyclohexanesulfonyl peroxide, tert.Amyl hydroperoxide, tert-amyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexyl carbonate, tert-amyl peroxyisopropyl carbonate, tert-amyl peroxyneodecanate, tert-amyl peroxy-3,5,5-trimethylhexanoate, tert-butyl monoperoxymaleate; this list is merely illustrative and not restrictive. If necessary, mixtures of different initiators can also be used for radical reactions. The suitability of an initiator or initiator mixture for radical reactions depends on its decomposition kinetics and the requirements to be met. With sufficient consideration of these general conditions, the skilled person will be able to select a suitable initiator.

[0084] For preparations that contain silicon-bonded hydrogen in addition to olefinically and acetylenically unsaturated groups, curing by a hydrosilylation reaction is possible. Suitable catalysts for promoting the hydrosilylation reaction are known catalysts from the state of the art.

[0085] Examples of such catalysts are compounds or complexes of the noble metal group containing platinum, ruthenium, iridium, rhodium, and palladium, preferably metal catalysts from the platinum group or compounds and complexes from the platinum group. Examples of such catalysts are metallic and finely divided platinum, which can be on supports such as silicon dioxide, aluminum oxide, or activated carbon, compounds or complexes of platinum such as platinum halides, e.g.PtCl 4 , H 2 PtCl 6 x6H 2 O, Na 2 PtCl 4 x4H 2 O, platinum-olefin complexes, platinum-alcohol complexes, platinum-alcoholate complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including reaction products of H 2 PtCl 4 x6H 2 O and cyclohexanone, platinum-vinyl-siloxane complexes, such as platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane, with or without detectable inorganically bound halogen, bis-(gamma-picoline)platinum chloride, trimethylenedipyridineplatinum chloride, dicyclopentadieneplatinum dichloride, dimethylsulfoxyethenylplatinum(II) dichloride, cyclooctadieneplatinum dichloride, norbornadieneplatinum dichloride, gammapicolineplatinum dichloride, Cyclopentadiene platinum dichloride, as well as reaction products of platinum tetrachloride with olefin and primary or secondary amine or primary and secondary amine such as the reaction product of platinum tetrachloride dissolved in 1-octene with sec-butylamine or.

[0086] Ammonium platinum complexes. In a further embodiment of the process according to the invention, complexes of iridium with cyclooctadienes, such as µ-dichlorobis(cyclooctadiene)-diiridium(I), are used.

[0087] This list is illustrative and not limiting. The development of hydrosilylation catalysts is a dynamic field of research that continually produces new, effective species that can naturally also be used in this field.

[0088] The hydrosilylation catalyst preferably comprises compounds or complexes of platinum, preferably platinum chlorides and platinum complexes, in particular platinum-olefin complexes and particularly preferably platinum-divinyltetramethyldisiloxane complexes.

[0089] In the process according to the invention, the hydrosilylation catalyst is used in amounts of 2 to 250 ppm by weight, preferably in amounts of 3 to 150 ppm, in particular in amounts of 3 to 50 ppm.

[0090] In a preferred embodiment, the polyorganosiloxanes of formula (I) are bonded to a metal substrate in a third step.

[0091] The polyorganosiloxanes of formula (I) are particularly suitable for use as binders and / or adhesion promoters for the production of metal-clad laminates, especially for electronic applications, especially for metal-clad laminates, and especially for use in high-frequency applications, especially those operating at frequencies of 1 GHz and above. Particular preference is given to the production of metal-clad electrical laminates, such as those used for the manufacture of printed circuit boards in electronic devices, especially for high-frequency applications.

[0092] Said metal-clad electrical laminates may, but do not have to, contain reinforcing materials. This means that they may, for example, contain reinforcing fabrics such as fiber fabrics or nonwovens, or they may be free of them. If a reinforcing material is included, it is preferably arranged in layers. A reinforcing layer can be composed of a variety of different fibers.

[0093] Such reinforcing layers help to control shrinkage behavior and provide increased mechanical strength.

[0094] If a reinforcing layer is used, the fibers forming this layer can be selected from a wide variety of options. Non-limiting examples of such fibers include glass fibers, such as E-glass fibers, S-glass fibers, and D-glass fibers; silica fibers; polymer fibers, such as polyetherimide fibers, polysulfone fibers, polyetherketone fibers, polyester fibers, polycarbonate fibers, aromatic polyamide fibers, or liquid crystalline fibers. The fibers can have a diameter of 10 nm to 10 µm. The reinforcing layer has a thickness of at most 200 µm, preferably at most 150 µm.

[0095] A preferred application is the use of the polyorganosiloxanes of formula (I) as binders or cobinders together with organic binders for the production of metal-clad laminates from glass fiber composites for the further production of printed circuit boards. The preferred metal is copper.

[0096] For the inventive use of the polyorganosiloxanes of formula (I), they can be used as the sole binder. They can also be used in blends with organic monomers, oligomers, and polymers.

[0097] Typically used organic monomers, oligomers and polymers include polyphenylene ethers, bismaleimides, bismaleimide triazine copolymers, hydrocarbon resins, both aliphatic such as polybutadiene, and aromatic such as polystyrene, as well as hybrid systems which have both aliphatic and aromatic character, such as styrene-polyolefin copolymers, whereby the form of the copolymers is again not restricted in principle, epoxy resins, cyanate ester resins and optionally others, whereby the selection is to be understood as illustrative and not restrictive.

[0098] Preferred organic monomers, oligomers, and polymers are oligomeric and polymeric polyphenylene ethers, monomeric, oligomeric, and polymeric bismaleimides, oligomeric and polymeric hydrocarbon resins, and bismaleimide triazine copolymers. The organic monomers, oligomers, and polymers can optionally be used in admixture with one another.

[0099] The proportion of organic monomers, oligomers and polymers in the preparations with the polyorganosiloxanes of the formula (I), if the organic components are used, is between 10 and 90% based on the mixture of the polyorganosiloxanes of the formula (I) and the organic monomers, oligomers and polymers 100%, preferably 20 - 90%, in particular 30 - 80%.

[0100] In addition, both the polyorganosiloxanes of formula (I) and the mixtures thereof with organic monomers, oligomers or polymers can be dissolved in further organic monomers, optionally with olefinically or acetylenically unsaturated groups, as reactive diluents, such as styrene, alpha-methylstyrene, para-methylstyrene and vinylstyrene, chloro- and bromostyrene.

[0101] Likewise, typical non-reactive solvents can be used to dissolve the polyorganosiloxanes of the formula (I) and optionally mixtures thereof with organic monomers, oligomers and polymers, such as, for example, aliphatic or aromatic solvents such as aliphatic mixtures with certain boiling ranges, toluene, xylene, ethylbenzene or mixtures of the same aromatics, ketones such as acetone, methyl ethyl ketone, cyclohexanone, carboxylic acid esters such as ethyl acetate, methyl acetate, ethyl formate, methyl formate, propionic acid methyl ester, propionic acid ethyl ester, wherein good solubility in particular of the mixtures of polyorganosiloxanes of the formula (I) with organic monomers, oligomers and polymers is most easily achieved in aromatic solvents such as toluene, xylene, ethylbenzene and mixtures thereof.

[0102] In the case where the polyorganosiloxanes of formula (I) are used in combination with an organic oligomer or polymer, or mixtures thereof, it is essential that polyorganosiloxanes of formula (I) are used that are compatible with the organic components of choice and do not lead to phase separation. In these cases, polyorganosiloxanes of formula (I) with a higher phenyl content should generally be used, since phenyl groups increase compatibility with the organic components. In particular, with organic polymers with a higher aromatic content, such as polyphenylene ethers or aromatic hydrocarbon resins, polyorganosiloxanes of formula (I) with a higher aromatic content should be used, with both the bridging aromatic groups and aromatic substituents terminally bonded to silyl units contributing to the compatibility adjustment.The exact amount of aromatic groups necessary to adjust the compatibility of the polyorganosiloxanes of formula (I) with a specific selection of organic binders must be determined depending on the selection of organic binders.

[0103] Just as it is possible to mix a plurality of organic polymers, which are optionally selected from different polymer classes and are to be used in the binder preparation. It is also possible to combine a plurality of polyorganosiloxanes of the formula (I) with one another in a binder preparation. This means that according to the invention, only a single polyorganosiloxane of the formula (I) can be used as a binder, and several polyorganosiloxanes of the formula (I) can be combined with one another to form a binder preparation. Likewise, according to the invention, only one polyorganosiloxane of the formula (I) can be combined with one or more organic polymers to form a binder preparation. It is also possible according to the invention to combine a plurality of polyorganosiloxanes of the formula (I) with one or more different organic polymers to form a binder preparation.

[0104] The compatibility of one or more polyorganosiloxanes of formula (I) with one or more organic oligomers or polymers can be easily determined by mixing a mixture of the organic binder(s) with the polyorganosiloxane(s) of formula (I), advantageously in a solvent that dissolves all selected components. The solvent is then removed by state-of-the-art methods, for example, by distillation or spray drying, and the resulting residue is evaluated visually or with the aid of microscopic, optionally electron microscopic, methods. Compatible mixtures can be recognized by the fact that no silicone domains separate from the organic components and are recognizable as a separate phase.

[0105] The use of additional formulation components, such as additives, which may optionally also include silanes, such as antifoams and deaerating agents, wetting and dispersing agents, flow control agents, compatibilizers, adhesion promoters, curing initiators, catalysts, stabilizers, fillers including pigments, dyes, inhibitors, flame retardants, and crosslinking aids, is permitted according to the invention, and the selection of such components is fundamentally unrestricted. In addition to compatibility tests in the sense of suitable miscibility behavior, compatibility tests with regard to reactivity may also be required to prevent premature gelling and ensure that sufficiently rapid polymerization or copolymerization of all components is achieved during curing, as well as tests for adequate wetting and, if necessary, other properties.This must be taken into account when drafting the text.

[0106] Examples of usable fillers are ceramic fillers such as silicas, for example precipitated silicas or pyrogenic silicas, which can be both hydrophilic and hydrophobic and are preferably hydrophobic and which can furthermore also be functionally and optionally reactively provided with organic groups on their surface, quartz, which can optionally be surface-treated or surface-functionalized so that it can carry reactive functional groups on the surface, aluminum oxides, aluminum hydroxides, calcium carbonate, talc, mica, clay, kaolin, magnesium sulfate, carbon black, titanium dioxide, zinc oxides, antimony trioxide, barium titanate, strontium titanate, corundum, wollastonite, zirconium tungstate, ceramic hollow spheres, aluminum nitride, silicon carbide, beryllium oxide, magnesium oxide, magnesium hydroxide, solid glass spheres, hollow glass spheres and boron nitride.Core-shell particles made of various materials can be used as additional fillers, such as silicone resin spheres coated with silica on the surface and polymer-coated elastomer particles, whereby the elastomer particles can optionally also be silicone elastomers, and a typical example of a surface coating of such an elastomer particle is a polymethyl methacrylate shell. The ceramic fillers preferably have particle sizes, expressed as a D 90 value, of 0.1 µm to 10 µm. Fillers are preferably present in amounts of 0.1 to 60 percent by weight, preferably 0.5 to 60 percent by weight, in particular 1 to 60 percent by weight, based on the total binder formulation consisting of binder(s), reactive monomers, additives, and fillers as 100%. This means that the amount of any non-reactive solvent used is not counted.

[0107] Among the fillers, those that are thermally conductive are particularly noteworthy. These include aluminum nitride, boron nitride, silicon carbide, diamond, graphite, beryllium oxide, zinc oxide, zirconium silicate, magnesium oxide, silicon oxide, and aluminum oxide.

[0108] In principle, the binder preparations can contain flame-retardant additives in an amount of typically 5 to 25 percent by weight. However, a special feature of the polyorganosiloxanes of formula (I) is that they reduce the need for flame-retardant additives, since the polyorganosiloxanes of formula (I) themselves already exhibit flame-retardant properties. Polysilsesquioxanes and siloxanes are known to exhibit flame-retardant properties, and it is part of the prior art for them to be used as flame-retardant additives themselves. It is therefore a particular advantage of the present invention that it succeeds in combining the function of the binder with the function of flame retardancy. Depending on the amount of polyorganosiloxanes of formula (I) used, the amount of flame-retardant additives can therefore be reduced.At an amount of at least 20 percent by weight based on the total mixture of all binders and reactive organic monomers used, the amount of flame-retardant additives is preferably only 0 to 10 percent by weight, particularly preferably 0 to 8 percent by weight, in particular 0 to 5 percent by weight, ie it is possible to dispense with the use of a flame-retardant additive when using the polyorganosiloxanes of the formula (I), depending on the selection of the organopolysiloxane and the amount used.

[0109] Typical examples of flame-retardant additives are hydrates of the metals Al, Mg, Ca, Fe, Zn, Ba, Cu, or Ni, and borates of Ba and Zn. The flame-retardant additives can be surface-treated and may optionally contain reactive groups on the surface. The flame-retardant additives can also be halogenated organic flame-retardant additives, such as hexachloroendomethylenetetrahydrophthalic acid, tetrabromophthalic acid, or dibromoneopentyl glycol. Examples of other flame-retardant additives include melamine cyanurate, phosphorus-containing components such as phosphinates, diphosphinates, phosphazenes, vinylphosphazenes, phosphonates, phosphaphenantrene oxides, and fine-grained melamine polyphosphates. Further examples of bromine-containing flame-retardant additives are bispentabromophenylethane, ethylenebistetrabromophthalimide, tetradecabromodiphenoxybenzene, decabromodiphenyl oxide or brominated polysilsesquioxanes.Some flame-retardant additives enhance their effect synergistically. This is the case, for example, with the combination of halogenated flame retardants with antimony trioxide.

[0110] Further examples of other components include antioxidants, stabilizers against degradation due to weathering, lubricants, plasticizers, coloring agents, phosphorescent or other agents for the purpose of marking and traceability and antistatic agents.

[0111] Preferably, the polyorganosiloxanes of formula (I) are crosslinked in a fourth step.

[0112] Crosslinking aids used include, in particular, polyunsaturated, radically curable or hydrosilylatable monomers and oligomers, as illustrated in the following non-limiting examples. These include, for example, diolefinically unsaturated components such as, for example, symmetrically olefinically unsaturated disubstituted disiloxanes, such as 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, 1,1,3,3-tetramethyl-1,3-dipropylmethacryloyldisiloxane, diolefinically unsaturated disubstituted organic monomers or oligomers, such as, for example, conjugated and non-conjugated dienes, such as 1,9-decadiene and 1,3-butadiene. This also includes triply olefinically unsaturated monomers or oligomers such as 1,2,4-trivinylcyclohexane, triallyl cyanurates or triallyl isocyanurates, tri(meth)acrylates, such as trimethylolpropane trimethacrylate.

[0113] This also includes four-fold unsaturated substituted monomers and oligomers such as 2,4,6,8- Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 2,4,6,8-tetraphenyl-2,4,6,8-tetravinylcyclotetrasiloxane, 2,2-Bis[[(2-methyl-1-oxoallyl)oxy]methyl]-1,3-propanediylbismethacrylate ( pentaerythritol tetramethacrylate), tetrallyl orthosilicate, Tetraallyl-cia,cis,cis,cis-1,2,3,4-cyclopentane tetracarboxylate, tetraallylsilane, glyoxalbis(diallylacetal).

[0114] Since hydrosilylation curing is also conceivable in addition to radical curing, multiply Si-H functional components can also act as crosslinkers, such as 1,1,3,3-tetramethyl-1, 3-disiloxane, 2,4,6,8- Tetramethylcyclotetrasiloxane, 1,4-bis(dimethylsilyl)benzene or multi-chain and / or terminal Si-H-functional oligo- and polyorganosiloxanes.

[0115] Suitable catalysts or initiators for the radical curing of binder preparations made from polyorganosiloxanes of formula (I) and organic monomers, oligomers, and polymers are the same as those already mentioned above, i.e., in particular, peroxides. In addition, other radical initiators are suitable for initiating the radical curing of both the polyorganosiloxanes of formula (I) alone and the described binder preparations, such as azo components such as α,α'azobis(isobutyronitrile), redox initiators such as combinations of peroxides such as hydrogen peroxide and iron salts, or azides such as acetyl azide.

[0116] The polyorganosiloxanes of formula (I) or the preparations containing them can be used for the application according to the invention both in solvent-free and solvent-based forms. They are generally used as solvent-based preparations to facilitate the homogeneous distribution of all components of the formulation and the wetting and saturation of any reinforcing layer used. A reinforcing layer is generally included. This is preferably a glass fiber fabric. The saturation of the reinforcing layer can be achieved by impregnating the preparation. Various technical solutions are available for this, including continuous processes if required, and the selection of these for producing the metal-clad laminates according to the invention is in no way limited.Non-limiting examples of application techniques are dipping, if necessary of webs of the reinforcement material via roller systems in continuous processes, spraying, flooding, doctoring, etc.

[0117] An advantage of the present invention is that all available technologies can be applied without restriction or modification, and no special new process is required for the use of the polyorganosiloxanes of formula (I). In this respect, the present invention is fully within the available state of the art in the production of metal-clad laminates. What is new is the use of the polyorganosiloxanes of formula (I) for the production of the metal-clad laminates in question, which was previously unknown.

[0118] Impregnation is followed by a drying step in which any solvent used is removed. State-of-the-art methods are also used for the drying process. These include, in particular, thermally induced evaporation with or without vacuum. By appropriately adjusting the reactivity and tackiness of the binder mixture used after this step under suitable conditions, such as cooling, storable composite materials are obtained that can be further processed at a later date if necessary. In a final step of the process, the binder preparation is polymerized using state-of-the-art methods. Any initiators used for the radical polymerization are heated above their decomposition temperature so that they decompose to form radicals and initiate the radical polymerization of the binder preparation.In principle, radiation curing methods can also be used.

[0119] If hydrosilylation curing is used instead of radical polymerization, a temperature must be applied in this step that is suitable for deactivating the inhibitor used with the hydrosilylation catalyst and releasing the catalytic activity of the hydrosilylation catalyst.

[0120] This step is generally carried out at elevated temperature, preferably from 100 to 390°C, more preferably from 100 to 250°C, especially from 130 to 200°C, with the temperature being effective for a time of preferably 5 to 180 minutes, more preferably 5 to 150 minutes, especially 10 to 120 minutes. Furthermore, it is customary to apply elevated pressure during this step. Typical pressures are in the range of 1 to 10 MPa, more preferably 1 to 5 MPa, especially 1 to 3 MPa.

[0121] The lamination of the composite material with a conductive metal layer occurs in this second step by applying a layer of at least one selected metal to one or both sides of the composite material consisting of the reinforcement layer and binder preparation before curing. This means that between the first step, consisting of impregnation and drying, and the second step, comprising the chemical curing of the binder preparation, the composite from the first step is laminated with at least one type of conductive metal.

[0122] In particular, at least one of the following can be considered as conductive metals: copper, stainless steel, gold, aluminum, silver, zinc, tin, lead, and transition metals. The thickness of the conductive layer, its shape, size, or surface texture are not fundamentally restricted. The conductive metal layer preferably has a thickness of 3 to 300 µm, particularly preferably 3 to 250 µm, in particular 3 to 200 µm. The thickness of the two layers of at least one type of conductive metal, if two layers are used, can vary and does not have to be identical. It is particularly preferred that the conductive metal is copper, and if two conductive layers of conductive metal are used, both layers are copper. The conductive metal is preferably used in the form of a foil made of the metal in question.The average roughness Ra of the metal foil used is preferably at most 2 µm, more preferably at most 1 µm, in particular at most 0.7 µm. The lower the surface roughness, the better the suitability of the respective foil for use in high-frequency applications, which are the preferred goal of the present invention. To improve the adhesion between the conductive metal layer and the composite of binder preparation and reinforcing layer, various prior art methods can be used, such as the use of an adhesion-promoting layer, the electroplating of the metal layer on the composite of binder preparation and reinforcing layer, or vapor deposition. The layer of conductive metal can sit directly on the composite of binder preparation and reinforcing layer or be bonded to it by an adhesion-promoting layer.

[0123] If no reinforcement layer is used, a layer of the binder preparation containing the polyorganosiloxanes of formula (I) is produced by depositing a layer of binder preparation on a carrier, such as a release film or release plate. In principle, any material from which the dried or cured binder preparation can be subsequently removed is suitable for the carrier, such as polytetrafluoroethylene, polyester, and the like. The removability and film-forming properties on the respective carrier material must be determined individually depending on the binder composition. The statements made regarding the process remain equally valid for this reinforcement-free variant.

[0124] Multilayer structures can be created from the reinforced or unreinforced composite materials from the first step and the laminated composite materials from the second step. For example, stacking multiple layers of the composite materials from the first step alternately with the laminated laminates from the second step. The uncured composite materials from the first step are then cured in a process that essentially corresponds to the procedure for producing metal-clad laminates. To create thicker layers, multiple layers of the reinforced or unreinforced composites from the first step can also be stacked one on top of the other in direct succession.

[0125] The polyorganosiloxanes of formula (I) can be used not only for the production of metal-clad laminates but also in corrosion-protective preparations, in particular for use for the purpose of corrosion protection at high temperatures.

[0126] In addition, the polyorganosiloxanes of formula (I) and preparations containing them can also be used for corrosion protection of reinforcing steel in reinforced concrete. Corrosion-inhibiting effects in reinforced concrete are achieved both when the polyorganosiloxanes of formula (I) and preparations containing them are incorporated into the concrete mix before it is molded and cured, and when the polyorganosiloxanes of formula (I) or preparations containing them are applied to the surface of the concrete after the concrete has cured.

[0127] In addition to the purpose of corrosion protection on metals, the polyorganosiloxanes of formula (I) can also be used to manipulate other properties of preparations containing the organopolysiloxanes according to the invention or of solids or films obtained from preparations containing the polyorganosiloxanes of formula (I), such as: Control of the electrical conductivity and electrical resistance Control of the leveling properties of a preparation Control of the gloss of a moist or cured film or an object Increasing the weathering resistance Increasing the chemical resistance Increasing the color stability Reducing the tendency to chalking Reducing or increasing the static and sliding friction on solids or films obtained from preparations containing the polyorganosiloxanes of the formula (I) Stabilizing or destabilizing foam in the preparation containing the polyorganosiloxanes of the formula (I) Improving the adhesion of the preparation containing the polyorganosiloxanes of the formula (I) to substrates Control of the filler and pigment wetting and dispersing behavior, Control of the rheological properties of the preparation containing the organopolysiloxanes according to the invention, Control of the mechanical properties, such as e.g.Flexibility, scratch resistance, elasticity, extensibility, bending ability, tear resistance, rebound behavior, hardness, density, tear resistance, compression set, behavior at different temperatures, coefficient of expansion, abrasion resistance and further gas permeability, resistance to water vapor, hot air, chemicals, weathering and radiation, sterilizability, of solids or films available which contain the polyorganosiloxanes of formula (I) or preparations containing them, control of electrical properties, such asDielectric loss factor, dielectric strength, dielectric constant, tracking resistance, arc resistance, surface resistance, specific dielectric strength, flexibility, scratch resistance, elasticity, extensibility, bending ability, tear behavior, rebound behavior, hardness, density, tear resistance, compression set, behavior at different temperatures of solids or films obtainable from the preparation containing the polyorganosiloxanes of the formula (I).

[0128] Examples of applications in which the polyorganosiloxanes of formula (I) can be used to manipulate the properties described above are the production of coating materials and impregnations and coatings and coverings obtained therefrom on substrates such as metal, glass, wood, mineral substrates, synthetic and natural fibers for the production of textiles, carpets, floor coverings or other goods that can be produced from fibers, leather, plastics such as films, and molded parts.The polyorganosiloxanes of formula (I) can also be used in preparations, with appropriate selection of the preparation components, as additives for the purposes of defoaming, promoting flow, hydrophobizing, hydrophilizing, filler and pigment dispersion, filler and pigment wetting, substrate wetting, promoting surface smoothness, and reducing adhesion and slip resistance on the surface of the cured composition obtainable from the additive-containing preparation. The polyorganosiloxanes of formula (I) can be incorporated into elastomer compositions in liquid or cured solid form. They can be used for reinforcement or to improve other performance properties, such as controlling transparency, heat resistance, yellowing tendency, or weathering resistance.

[0129] All symbols in the above formulas have their meanings independent of each other. In all formulas, the silicon atom is tetravalent. Examples:

[0130] All percentages are based on weight. Unless otherwise stated, all manipulations are carried out at room temperature (23°C) and under atmospheric pressure (1.013 bar).

[0131] Unless otherwise stated, all data describing product properties apply at room temperature of 23°C and under normal pressure (1,013 bar).

[0132] The devices are commercially available laboratory devices, such as those offered for sale by numerous device manufacturers.

[0133] Ph means one phenyl radical = C 6 H 5 -Me means one methyl radical = CH 3 -. Me 2 means two methyl radicals.

[0134] PPE stands for polyphenylene ether.

[0135] HCl means hydrogen chloride.

[0136] In this text, substances are characterized by data obtained by instrumental analysis. The underlying measurements are either performed according to publicly available standards or determined using specially developed procedures. To ensure the clarity of the presented teaching, the methods used are listed below.

[0137] In all examples, parts and percentages are by weight unless otherwise stated. Viscosity:

[0138] Unless otherwise stated, viscosities are determined by rotational viscometric measurement according to DIN EN ISO 3219. Unless otherwise stated, all viscosity data apply at 25°C and a standard pressure of 1013 mbar. Refractive index:

[0139] The refractive indices are determined in the wavelength range of visible light, unless otherwise stated, at 589 nm at 25°C and normal pressure of 1013 mbar according to the standard DIN 51423. Transmission:

[0140] The transmission is determined by UV-VIS spectroscopy. A suitable instrument is the Analytik Jena Specord 200.

[0141] The measurement parameters used are: Range: 190 - 1100 nm, Step size: 0.2 nm, Integration time: 0.04 s, Measurement mode: Step mode. First, the reference measurement (background) is performed. A quartz plate, attached to a sample holder (dimensions of the quartz plate: H x W approx. 6 x 7 cm, thickness approx. 2.3 mm), is placed in the sample beam path and measured against air.

[0142] Next, the sample is measured. A quartz plate with a sample applied to it (approximately 1 mm thick) is attached to the sample holder. It is placed in the sample beam path and measured against air. Internal comparison with the background spectrum yields the sample's transmission spectrum. Molecular compositions:

[0143] The molecular compositions are determined by nuclear magnetic resonance spectroscopy (for terminology see ASTM E 386: High-resolution nuclear magnetic resonance spectroscopy (NMR): Terms and Symbols), measuring the 1< H nucleus and the 29< Si nucleus. Description 1< H-NMR measurement:

[0144] Solvent: CDCl3, 99.8% Sample concentration: approx. 50 mg / 1 ml CDCl3 in 5 mm NMR tubes

[0145] Measurement without addition of TMS, spectra referencing of residual CHCl3 in CDCl3 to 7.24 ppm Spectrometer: Bruker Avance I 500 or Bruker Avance HD 500 Probe head: 5 mm BBO probe head or SMART probe head (Bruker) Measurement parameters:

[0146] Pulprog = zg 30 TD = 64 k NS = 64 or 128 (depending on the sensitivity of the probe head) SW = 20 , 6 ppm AQ = 3 , 17 s D 1 = 5 s SFO 1 = 500 , 13 MHz O 1 = 6 , 175 ppm Processing parameters:

[0147] SI = 32 k WDW = EM LB = 0 , 3 Hz

[0148] Depending on the type of spectrometer used, individual adjustments of the measurement parameters may be necessary. Description 29< Si-NMR measurement:

[0149] Solvent: C6D6 99.8%d / CCl4 1:1 v / v with 1 wt% Cr(acac) 3 as relaxation reagent Sample concentration: approx. 2 g / 1.5 ml solvent in 10 mm NMR tubes Spectrometer: Bruker Avance 300 Probe head: 10 mm 1H / 13C / 15N / 29Si glass-free QNP probe head (Bruker) Measurement parameters:

[0150] Pulprog = zgig60 TD = 64k NS = 1024 (depending on the sensitivity of the probe head) SW = 200 ppm AQ = 2.75 s D1 = 4 s SFO1 = 300.13 MHz O1 = -50 ppm Processing parameters:

[0151] SI = 64k WDW = EM LB = 0.3 Hz

[0152] Depending on the type of spectrometer used, individual adjustments of the measurement parameters may be necessary. Molecular weight distributions:

[0153] Molecular weight distributions are determined as weight-average Mw and number-average Mn using gel permeation chromatography (GPC or size exclusion chromatography (SEC)) with a polystyrene standard and a refractive index detector (RI detector). Unless otherwise stated, THF is used as the eluent and DIN 55672-1 is applied. Polydispersity is the ratio Mw / Mn. Glass transition temperatures:

[0154] The glass transition temperature is determined by differential scanning calorimetry (DSC) according to DIN 53765, perforated crucible, heating rate 10 K / min. Determination of particle size:

[0155] Particle sizes were measured using the dynamic light scattering (DLS) method, determining the zeta potential. The following tools and reagents were used for the determination: 10 x 10 x 45 mm polystyrene cuvettes, disposable Pasteur pipettes, and ultrapure water.

[0156] The sample to be measured is homogenized and filled into the measuring cuvette without any bubbles.

[0157] The measurement is carried out at 25°C after an equilibration time of 300s with high resolution and automatic measurement time setting.

[0158] The specified values ​​always refer to the value D(50). D(50) is defined as the volume-averaged particle diameter where 50% of all measured particles have a volume-averaged diameter smaller than the stated value D(50). Determination of dielectric properties: Df, Dk

[0159] The dielectric properties are determined according to IPC TM 650 2.5.5.13 using a Keysight / Agilent E8361A network analyzer using the split-cylinder resonator method at 10 GHz. Performing the microscopy:

[0160] The micro- / nanostructure was characterized by light microscopy and transmission electron microscopy. Light microscopy:

[0161] Sample preparation: 1 drop of sample (undiluted) on a slide; cover with a coverslip Device: LEICA DMRXA2 with CCD camera LEICA DFC420 (2592x1944 pixels) Illustration: Transmitted light - interference contrast, various magnification levels

[0162] Transmission electron microscopy: Sample preparation: 1 drop of sample (dilution 1:20, adjustment necessary if necessary) on a coated TEM grid; addition of a contrast agent if required; drying at room temperature. Device: ZEISS LIBRA 120 with Sharp Eye CCD camera (1024x1024 pixels). Image: Excitation voltage 120 kV; TEM brightfield; various magnification levels. Adhesion test by peel strength test:

[0163] The adhesion of the metal layers laminated to the composite layers with or without reinforcement material was determined according to the method IPC-TM 650 2.4.8 "Peel Strength of Metallic Clad Laminates" in the "as received" version, ie without thermal stress or exposure.

[0164] A 35 µm copper foil, mass 285 ± 10 g / m 2< , surface roughness Rz ≤ 8 µm, mean roughness Ra ≤ 0.4 µm was laminated on both sides to a composite layer of 100 µm thickness, with 200°C, 2.0 MPa, 30 mm Hg column acting for 180 min for curing and lamination. Synthesis example 1: Preparation of an organopolysiloxane by the process according to the invention:

[0165] A mixture of 1267.8 g (6 mol) of phenyltrichlorosilane, 372.6 g (1.5 mol) of 3-(trimethoxysilyl)propyl methacrylate, and 780 g of xylene is added to a mixture of 3600 g of water over a period of 4 hours. The reaction of the chlorosilane in water is exothermic and produces hydrochloric acid, which dissolves in the water. Care is taken to ensure that the temperature does not exceed 50°C due to the exothermic temperature increase, and the dosing rate is reduced if necessary to avoid exceeding this temperature limit.

[0166] After the addition is complete, stir for 15 minutes and then turn off the stirrer. The reaction mixture separates into a hydrochloric acid aqueous phase, which sits at the bottom of the reaction vessel, and an organic silicone phase, which sits at the top. The aqueous phase is drained off.

[0167] One liter of water is added to the remaining organic phase, stirred for 30 minutes, and then the stirrer is turned off. The aqueous phase separates to the bottom and is drained. This process is repeated until the residual HCl content in the organic phase, determined by state-of-the-art acid-base titration, is < 20 ppm.

[0168] If the aqueous phase settles to the top, wash with a 10% sodium chloride aqueous solution instead of demineralized water, or add 100 g of sodium chloride, stir again for 30 min, and then repeat the phase separation.

[0169] The organic phase is then distilled at ambient pressure in a water separator until no more water separates, i.e. the organic phase is technically anhydrous.

[0170] The residual water content of the organic preparation is determined by Karl Fischer titration and is 856 ppm.

[0171] Through 1< H-NMR The content of silanol groups, expressed as OH groups with a molecular weight of 17 g / mol, is determined to be 1.6 weight percent. With a molecular weight of the intermediate from the first reaction step of Mw = 3347 g / mol, this corresponds to a silanol content of 3.2 mol OH.

[0172] The reaction mixture is allowed to cool to 40°C, and then 318 g (3.2 mol) of dimethyldichlorosilane are added, followed by 261 g (3.3 mol) of pyridine. The first addition takes 30 minutes, the second 45 minutes. An exothermic temperature rise is observed. Here, too, the temperature is limited to 50°C by adjusting the addition rate. After the addition is complete, the mixture is stirred for 60 minutes to complete the reaction.

[0173] After the reaction is complete, the mixture is washed three times with one liter of deionized water each time and the aqueous phase is separated as described above.

[0174] After the final phase separation, the residual HCl content in the organic phase is < 20 ppm. The solvent content is reduced by distillation, resulting in a resin solids content of 80%, i.e., the final resin solution consists of 20% xylene and 80% polyorganosiloxane.

[0175] Methoxy groups are not detectable by NMR. The residual silanol content is 0.05 weight percent, determined by 1< H NMR spectroscopy.

[0176] SEC: Mw = 4914 g / mol, Mn = 1904 g / mol, polydispersity PD = 2.58.

[0177] After 29< Si NMR is the molar composition of the silicon-containing part of the preparation: Me 2 Si(H)O 1 / 2: 30.96% H 2 C=C(CH 3 )C(=O)-O-(CH 2 ) 3 -SiO 3 / 2: 13.89% PhSiO 3 / 2: 55.15%

[0178] This product is hereinafter referred to as 1.1.

[0179] Synthesis example 2: Preparation of a silphenylene-bridged organopolysiloxane by the process according to the invention and comparison with a non-inventive procedure which is hydrolytic in both steps. Synthesis of the silphenylene precursor:

[0180] 1,4-Bis(dimethoxyphenylsilyl)benzene according to literature instructions according to Xunjun Chen, Minghao Yi, Shufang Wu, Lewen Tan, Yixin Xu, Zhixing Guan, Jianfang Ge and Guoqiang Yin: Synthesis of Silphenylene-Containing Siloxane Resins Exhibiting Strong Hydrophobicity and High Water Vapor Barriers, Coatings 2019, 9, 481; doi:10.3390 / coatings9080481 www.mdpi.com / journal / coatings

[0181] 1,4-Bis(dimethoxyphenylsilyl)benzene is obtained by reacting trimethoxyphenylsilane with a Grignard reagent obtained from 1,4-dibromobenzene according to the literature procedure "2.2. Synthesis of the 1,4-Bis(Dimethoxyphenylsilyl)Benzene (BDMPD)." The structure was confirmed by 1< H NMR spectroscopy and comparison with the cited literature.

[0182] The procedure for resin synthesis corresponds to that described in synthesis example 1 with the following differences: A mixture of 845.2 g (= 4 mol) phenyltrichlorosilane, 546.7 g (1.3 mol) 1,4-bis(dimethoxyphenylsilyl)benzene, 198.7 g (0.8 mol) 3-(trimethoxysilyl)propyl methacrylate, 820 g xylene and a mixture of 2400 g deionized water

[0183] The dosing time is 4 hours.

[0184] The intermediate obtained after the first step has a molecular weight of Mw = 1247 and contains 3% by weight of silanol groups, determined by 1< H-NMR as OH with a molecular weight of 17 g / mol, i.e. 2.2 mol OH.

[0185] At this point, the synthesis according to US 2018022053 would already end according to the examples given there as illustrative and according to the text of the description of US 2018022053.

[0186] To reduce the silanol content, the same procedure is used as described in Synthesis Example 1, but in contrast to Synthesis Example 1, in this case 265.1 g (2.2 mol) of vinyldimethylchlorosilane and 174 g (2.2 mol) of pyridine are used.

[0187] The product received contains 1< H-NMR No methoxy groups were detectable. This means that the methacrylate-functional trimethoxysilane was completely condensed in, and the resulting methanol was removed during processing. The proportion of silanol groups was reduced to approximately 0.05 percent by weight (determined by 1< H NMR) by post-treatment.

[0188] The following molecular weights were determined by SEC (eluent toluene): Mw = 2347 g / mol, Mn = 1503 g / mol, polydispersity PD = 1.56.

[0189] After 29< Si NMR is the molar composition of the silicon-containing part of the preparation: Me 2 Si(Vi)O 1 / 2: 26.54% H 2 C=C(CH 3 )C(=O)-O-(CH 2 ) 3 -SiO 3 / 2: 9.98% O 2 / 2 (Ph)Si-C 6 H 4 -Si(Ph)O 2 / 2: 15.23% PhSiO 3 / 2: 48.25%

[0190] This product is hereinafter referred to as 2.1.

[0191] As an alternative to the non-hydrolytic procedure according to the invention, the following hydrolytic procedure is carried out to reduce the silanol groups, which is not mentioned in US 2018022053, but could in principle fall within the scope of the invention since the number of stages of the hydrolytic process is not limited therein.

[0192] To obtain an anhydrous initial charge from the first reaction step, 200 g of water are added to the previously distilled xylene reaction mixture. Then, 265.1 g (2.2 mol) of vinyldimethylchlorosilane are slowly added, adjusting the metering rate to keep the reaction temperature (internal temperature in the reaction vessel) below 50°C. After the metering is complete, the mixture is stirred for 60 minutes without heating or cooling to allow the reaction of the silanol groups with the vinyldimethylchlorosilane or the resulting tetramethyldivinyldisiloxane to complete.

[0193] The aqueous phase is separated as described above and then washed three times with one liter of water each time, as described above. If necessary, phase separation can be improved by heating the heating jacket to 60°C with the stirrer turned off. After the washing steps, the HCl content in the xylene solution is less than 20 ppm.

[0194] The amount of toluene is reduced by distillation in vacuum (20 mbar) at 110°C until a solution of 80% resin in 20% xylene is obtained.

[0195] The product received contains 1< H-NMR No methoxy groups were detectable. This means that the methacrylate-functional trimethoxysilane was completely condensed in here as well, and the resulting methanol was removed during processing. However, the proportion of silanol groups could only be reduced to 0.9 weight percent (determined by 1< H NMR) by post-treatment.

[0196] The following molecular weights were determined by SEC (eluent toluene): Mw = 7347 g / mol, Mn = 2903 g / mol, polydispersity PD = 2.53.

[0197] This reveals a further difference from the process according to the invention. The vinyldimethylsilane used to reduce the silanol groups partially forms the symmetrical disiloxane, which is removed by distillation during processing. The HCl formed during the reaction of the chlorosilane with water catalyzes the reaction of the silanol groups. While this leads to a reduction in the silanol groups, it results in a significantly higher molecular weight due to condensation, thus significantly increasing the risk that the polyorganosiloxane obtained from the first step will polymerize to an insoluble product and thus become unusable. This effect is efficiently avoided by the process according to the invention.

[0198] After 29< Si NMRis the molar composition of the silicon-containing part of the preparation: Me 2 Si(Vi)O 1 / 2: 11.54% H 2 C=C(CH 3 )C(=O)-O-(CH 2 ) 3 -SiO 3 / 2: 11.98% O 2 / 2 (Ph)Si-C 6 H 4 -Si(Ph)O 2 / 2: 19.23% PhSiO 3 / 2: 57.25%

[0199] The silanol groups are bound to the PhSiO 3 / 2 units.

[0200] This product is hereinafter referred to as 2.2.

[0201] The NMR data also reveal the incomplete reaction of the chlorosilane used in the hydrolytic procedure, as the proportion of Me 2 Si(Vi)O 1 / 2 units would have to be significantly higher for complete reaction into the polyorganosiloxane from the first step. This clearly demonstrates that the anhydrous procedure is superior to the aqueous procedure for the controlled reduction of the polar silanol groups in a robust, controllable and manageable process.

[0202] Synthesis example 3:Preparation of an organopolysiloxane with an alkylene bridge by the process according to the invention and comparison with an aqueous procedure not according to the invention.

[0203] The synthesis according to Synthesis Example 1 is repeated, whereby, in contrast to Synthesis Example 1, the following quantities are used: Phenyltrichlorosilane: 422.6 g (= 2 mol) 1,2-bis(dichloromethylsilyl)ethane: 341.35 g (1.35 mol) 198.7 g (0.8 mol) 3-(trimethoxysilyl)propyl methacrylate 820 g xylene and a mixture of 2400 g deionized water

[0204] The dosing time is 4 hours.

[0205] The intermediate obtained after the first step has a molecular weight of Mw = 2247 and contains 2.5% by weight of silanol groups, determined by 1< H-NMR as OH with a molecular weight of 17 g / mol, i.e. 3.3 mol OH.

[0206] At this point, the synthesis according to US 2018022053 would already end according to the examples given there as illustrative and according to the text of the description of US 2018022053.

[0207] To reduce the silanol content, the same procedure is used as described in Synthesis Example 1, but in contrast to Synthesis Example 1, in this case 397.7 g (3.3 mol) of vinyldimethylchlorosilane and 261 g (3.3 mol) of pyridine are used.

[0208] Methoxy groups are not detectable by NMR. The proportion of silanol groups was reduced to approximately 0.05 weight percent (determined by 1< H NMR) by post-treatment.

[0209] The following molecular weights were determined by SEC (eluent toluene): Mw = 2954 g / mol, Mn = 1919 g / mol, polydispersity PD = 1.53.

[0210] After 29< Si NMR is the molar composition of the silicon-containing part of the preparation: Me 2 Si(Vi)O 1 / 2: 44.29% H 2 C=C(CH 3 )C(=O)-O-(CH 2 ) 3 -SiO 3 / 2: 10.78% O 2 / 2 (Me)Si-C 2 H 4 -Si(Me)O 2 / 2: 18.12% PhSiO 3 / 2: 26.81%

[0211] This product is referred to as 3.1 below.

[0212] As an alternative to the non-hydrolytic procedure according to the invention, the following hydrolytic procedure is carried out to reduce the silanol groups, which is not mentioned in US 2018022053, but could in principle fall within the scope of the invention since the number of stages of the hydrolytic process is not limited therein.

[0213] Analogous to the procedure in Synthesis Example 2, 300 g of water are added to the anhydrous initial mixture from the first reaction step.

[0214] Thereafter, 397.7 g (3.3 mol) of vinyldimethylchlorosilane are slowly added and the procedure is continued as described in Synthesis Example 2.

[0215] The product received contains 1< H-NMRNo methoxy groups were detectable. However, the proportion of silanol groups could only be reduced to 1.0 weight percent (determined by 1< H NMR) after post-treatment.

[0216] SEC: Mw = 6974 g / mol, Mn = 2812 g / mol, polydispersity PD = 2.48.

[0217] According to 29< Si-NMR, the molar composition of the silicon-containing portion of the preparation is: Me 2 Si(Vi)O 1 / 2: 21.69% H 2 C=C(CH 3 )C(=O)-O-(CH 2 ) 3 -SiO 3 / 2: 15.09% O 2 / 2 (Me)Si-C 2 H 4 -Si(Me) O 2 / 2: 25, 47% PhSiO 3 / 2: 37.75%

[0218] The silanol groups are bound to the PhSiO 3 / 2 units.

[0219] This product is referred to as 3.2 below.

[0220] Here, too, a higher molecular weight and a less complete reduction of the silanol groups are achieved in the hydrolytic process than in the non-hydrolytic process according to the invention.

[0221] Synthesis example 4:Preparation of an organopolysiloxane with Si-Si bond by the process according to the invention in comparison to a non-inventive aqueous procedure.

[0222] The synthesis according to Synthesis Example 1 is repeated, whereby, in contrast to Synthesis Example 1, the following starting materials and quantities are used: Phenyltrichlorosilane: 422.6 g (= 2 mol) 198.7 g (0.8 mol) 3-(trimethoxysilyl)propyl methacrylate 296.4 g (1.3 mol) 1,1,2,2-tetrachloro-1,2-dimethyldisilane 820 g xylene and a mixture of 2400 g deionized water

[0223] The dosing time is 4 hours.

[0224] The intermediate obtained after the first step has a molecular weight of Mw = 1867 g / mol and contains 2.9 wt% silanol groups, determined by 1< H-NMR as OH with a molecular weight of 17 g / mol, i.e. 3.2 mol OH.

[0225] At this point, the synthesis according to US 2018022053 would already end according to the examples given there as illustrative and according to the text of the description of US 2018022053.

[0226] To reduce the silanol content, the same procedure is used as described in Synthesis Example 1, but in contrast to Synthesis Example 1, in this case 385.6 g (3.2 mol) of vinyldimethylchlorosilane and 261 g (3.3 mol) of pyridine are used.

[0227] Methoxy groups are not detectable by NMR. The proportion of silanol groups was reduced to approximately 0.05 weight percent (determined by 1< H NMR) by post-treatment.

[0228] The following molecular weights were determined by SEC (eluent toluene): Mw = 2479 g / mol, Mn = 1678 g / mol, polydispersity PD = 1.47.

[0229] According to 29< Si-NMR, the molar composition of the silicon-containing portion of the preparation is: Me 2 Si(Vi)O 1 / 2: 40.34% H2 C=C(CH3 )C(=O)-O-(CH2)3-SiO3 / 2: 10.96% O2 / 2 (Me)Si-Si(Me)O2 / 2: 21.31% PhSiO3 / 2: 27.39%

[0230] This product is hereinafter referred to as 4.1.

[0231] As an alternative to the non-hydrolytic procedure according to the invention, the following hydrolytic procedure is carried out to reduce the silanol groups, which is not mentioned in US 2018022053, but could in principle fall within the scope of the invention since the number of stages of the hydrolytic process is not limited therein.

[0232] Analogous to the procedure in Synthesis Example 2, 300 g of water are added to the anhydrous initial mixture from the first reaction step.

[0233] Thereafter, 385.6 g (3.2 mol) of vinyldimethylchlorosilane are slowly added and the procedure is continued as described in Synthesis Example 2.

[0234] In the resulting product, no methoxy groups were detectable by 1< H NMR. However, the proportion of silanol groups could only be reduced to 1.1 weight percent (determined by 1< H NMR) by post-treatment.

[0235] SEC: Mw = 4974 g / mol, Mn = 2006 g / mol, polydispersity PD = 2.48.

[0236] According to 29< Si-NMR, the molar composition of the silicon-containing portion of the preparation is: Me2Si(Vi)O1 / 2: 18.96%

[0237] The silanol groups are bound to the PhSiO 3 / 2 units.

[0238] This product is referred to as 4.2 below.

[0239] Here, too, a higher molecular weight and a less complete reduction of the silanol groups are achieved in the hydrolytic process than in the non-hydrolytic process according to the invention. Application Example 1: Use of the organopolysiloxanes prepared according to the invention and not according to the invention according to Synthesis Examples 1 - 4 for the production of metal-clad laminates.

[0240] The organopolysiloxanes prepared according to Synthesis Examples 1 to 4 and the comparative examples contained therein were used as binders to produce copper-clad laminates with a glass fiber-reinforced composite layer. The following raw materials were used: Copper foil: 35 µm thick copper foil (285 ± 10 g / m ) from Jiangtong-yates Copper Foil Co. Ltd., with a surface roughness of Rz ≤ 8 µm and a mean roughness of Ra ≤ 0.4 µm, purity ≥ 99.8%.

[0241] Glass fiber: E-glass fiber type 1080 E manufactured by Changzhou Xingao Insulation Materials Co. Ltd. Thickness 0.055 ± 0.012 mm, 47.5 ± 2.5 g / m 2< .

[0242] In this example, all organopolysiloxanes were used as solutions in xylene. The solutions each contained 80% organopolysiloxane and 20% xylene.

[0243] To initiate curing, the organopolysiloxanes were each mixed with 1 weight percent of dicumyl peroxide based on the amount of polyorganosiloxane used, which was evenly distributed in the resin matrix by stirring.

[0244] Laminates were produced by impregnating 30 x 30 cm glass fiber layers layer by layer with the respective organopolysiloxane, optionally as a xylene solution, using a deaerator roller to ensure that no bubbles were formed. The glass fiber layers were placed on a dimensionally stable, flat stainless steel base, onto which a layer of copper foil was applied before the first layer of glass fiber was applied. A total of three layers of glass fiber fabric were impregnated one after the other. To remove any solvent, the impregnated fabrics were dried to constant weight at 60°C in a vacuum drying oven at 10 mbar. A second layer of copper foil was then applied on top of the impregnated glass fiber layer, and another dimensionally stable stainless steel plate was placed on top. The laminate was heated in a heatable press at 2 MPa pressure, for 120 minutes at 200°C and 30 mbar vacuum.Copper-clad laminates with a total thickness of 260 ± 20 µm are obtained.

[0245] The dielectric properties were determined according to IPC TM 650 2.5.5.13 using a Keysight / Agilent E8361A network analyzer using the split-cylinder resonator method at 10 GHz. The following values ​​were obtained: Organopolysiloxane D k D f 1.1 (according to the invention) 2,78 0,0021 2.1 (according to the invention) 2,89 0,0022 2.2 (not according to the invention) 3,20 0,0040 3.1 (according to the invention) 2,77 0,0023 3.2 (not according to the invention) 3,34 0,0041 4.1 (according to the invention) 2,79 0,0022 4.2 (not according to the invention) 3,36 0,0041

[0246] The D f and D k values ​​of the copper-clad laminates made from the organopolyiloxanes according to the invention are significantly lower than the D f and D k values ​​achieved with the organopolysiloxanes using the prior art procedure. Since the lowest possible dielectric loss factors and dielectric constants are desired for high-frequency applications, the effect of the invention is clearly evident. Application Example 2: Use of the organopolysiloxanes prepared according to the invention and those not prepared according to the invention according to Synthesis Examples 1 - 4 for the production of metal-clad laminates via prepregs.

[0247] For this example, the organopolysiloxanes from Synthesis Examples 1-4 were used as a solution in xylene according to both the inventive and non-inventive procedures, using preparations of 20% xylene and 80% polyorganosiloxane in each case.

[0248] Instead of directly constructing the laminate without a prepreg intermediate, this time prepregs were produced by impregnating the glass fiber layers with the resin preparation as individual layers on a polytetrafluoroethylene film and then drying them to constant weight in a vacuum drying cabinet. Three layers of impregnated glass fiber fabric produced in this way were then stacked on top of each other on a copper foil, and the stack was finished with a layer of copper foil. This multilayer structure was pressed and cured between two dimensionally stable stainless steel plates in a vacuum press under the conditions specified in Example 1, analogously to Application Example 1.

[0249] The obtained laminates had thicknesses of 290 ± 20 µm.

[0250] The following dielectric properties were measured on the obtained laminates: Organopolysiloxane D k D f 1.1 (according to the invention) 2,78 0,0020 2.1 (according to the invention) 2,89 0,0020 2.2 (not according to the invention) 3,20 0,0039 3.1 (according to the invention) 2,77 0,0021 3.2 (not according to the invention) 3,34 0,0040 4.1 (according to the invention) 2,79 0,0020 4.2 (not according to the invention) 3,36 0,0040

[0251] The D k and D f values ​​achieved for the copper-clad laminates made from the organopolyiloxanes prepared according to the invention are significantly lower than the D f and D k values ​​achieved with the organopolysiloxanes from the comparative examples. Since the lowest possible dielectric loss factors and dielectric constants are desired for high-frequency applications, the effect of the invention is clearly evident. Application Example 3 Use of the organopolysiloxanes prepared according to the invention and not according to the invention according to Synthesis Example 1 - 4 for the production of metal-clad laminates in a mixture with organic polymers

[0252] The procedure is essentially the same as described in Application Example 2, except that this time organic polymers were mixed with the organopolysiloxanes. The final solvent-free mixtures always contained 30 weight percent organopolysiloxane and 70 weight percent organic polymers. The organic polymers used were triallyl isocyanurate, NORYL SA 9000, an alpha-omega methacrylate-terminated polyphenylene ether purchased from SABIC, Mn = 2500 g / mol, Tg = 160°C, and B 3000 from Nippon Soda, a liquid polybutadiene with Mn = 3200 and a viscosity at 45°C of 210 poise and more than 85% 1,2-vinyl structure in the polymer chain.

[0253] The polymers were always used in the same ratio. They were dissolved or dispersed in xylene, with 30 parts by weight of SA 9000, 25 parts by weight of B 3000, and 15 parts by weight of triallyl isocyanurate being dispersed with 100 parts by weight of xylene.

[0254] The resulting preparation was mixed with the xylene solutions of the organopolysiloxanes according to Application Example 2 such that the specified mixing ratio of 30% organopolysiloxane to 70% organic components was present in the resulting solution. These solutions were then used to produce copper-clad laminates over prepregs as described in Application Example 2.

[0255] The obtained laminates had thicknesses of 290 ± 20 µm.

[0256] The following dielectric properties were measured on the obtained laminates: with the organopolysiloxane from D k D f 1.1 (according to the invention) 2,91 0,0029 2.1 (according to the invention) 2, 65 0,0022 2.2 (not according to the invention) 3,28 0,0040 3.1 (according to the invention) 2,78 0,0021 3.2 (not according to the invention) 3,29 0,0041 4.1 (according to the invention) 2,59 0,0022 4.2 (not according to the invention) 3,21 0,0042

[0257] The D k and D f values ​​achieved for the copper-clad laminates using the organopolyiloxanes prepared according to the invention are significantly lower than the D f and D k values ​​achieved with the organopolysiloxanes from the comparative examples. Since the lowest possible dielectric loss factors and dielectric constants are desired for high-frequency applications, the effect of the invention is clearly evident.

Claims

1. Process for preparing polyorganosiloxanes of the formula (I)         [O3-a / 2RaSiY(SiRaO3-a / 2)b]c(R1SiO3 / 2)d(R22SiO2 / 2)e(R33SiO1 / 2)f(SiO4 / 2)g [O3-h / 2R4hSi(SiR52)iSiR4jO3-j / 2]k     (I) where the radicals R may be identical or different radicals and are either a hydrogen radical or a monovalent, Si-C-bonded unsubstituted or heteroatom-substituted organic hydrocarbon radical having 1 to 18 carbon atoms, which may also be an unsaturated hydrocarbon radical, Y is a chemical bond, an oxygen atom or a di- to dodecavalent organic unsubstituted or heteroatom-substituted organic radical having 1 to 24 carbon atoms and bonded to the silicon atoms by Si-C linkage, the radicals R1, R2 and R3 independently of one another are a hydrogen radical or a saturated or unsaturated, SiC-bonded C1 - C18 hydrocarbon radical, which may be unsubstituted or substituted by heteroatoms, or are a C1 - C12 hydrocarbon radical which is bonded via an oxygen atom and may contain heteroatoms, or are a silanol radical, where the radicals R1, R2 and R3 may adopt their definition in each case independently of one another, and so two or more radicals R1, R2 and / or R3 bonded on the same silicon atom may be different radicals from the group defined, the radicals R4 independently of one another are either a hydrogen radical, a silanol radical or a monovalent, Si-C- or Si-O-C-bonded, unsubstituted or heteroatom-substituted organic hydrocarbon radical having 1 to 18 carbon atoms, which may also be an unsaturated hydrocarbon radical, the radicals R5 independently of one another either are a hydrogen radical, a monovalent, Si-C-bonded, unsubstituted or heteroatom-substituted organic hydrocarbon radical having 1 to 18 carbon atoms, which may also be an unsaturated hydrocarbon radical, or are a radical of the formula (II)         [O3-a / 2RaSi-Y(SiRaO3-a / 2)b]c(R1SiO3 / 2)d(R22SiO2 / 2)e(R33SiO1 / 2)f(SiO4 / 2)g     (II) where, based on all the radicals Y, R, R1, R2, R3, R4 and R5 as 100 mol%, at least 0.1 mol% must be olefinically or acetylenically unsaturated radicals, based on all the radicals Y, R, R1, R2, R3, R4 and R5 as 100 weight%, in total at most 3 wt% are Si-O-C-bonded radicals and silanol radicals, and, based on all the radicals Y, R, R1, R2, R3, R4 and R5 as 100 weight%, in total at most 0.5 wt% are silanol radicals, a is 0, 1 or 2, where the indices a on both sides of the group Y may adopt their definition independently of one another, and so different a independently of one another may have different values within the specified value range, b is a number with a value of 1 to 11, preferably 1, c has a value of 0 to 0.9, d has a value of 0 to 0.8, e has a value of 0 to 0.5, f has a value of 0.01 to 0.6, g has a value of 0 to 0.6, h and j independently of one another are 0, 1 or 2, i is an integer with a value of 0 to 50 and k has a value of 0 to 0.9, where c+d+e+f+g+k = 1, at least one value c, d or k is > 0 and e+g is ≤ 0.6, where the radicals R, R1, R2, R3, R4 and R5 and the indices a, b, c, d, e, f, g, h and i in formula (I) and in formula (II) independently of one another may have the same definitions and may adopt these definitions independently of one another within the value ranges described, by reacting, in a first step, silanes of the formula (III)         R6lSiR74-l     (III), where R7 is a hydrolysable group, l is an integer with a value of 0, 1 or 2 and R6 if l = 1 is a radical R1 and if l = 2 is a radical R2, and / or di-, oligo- or polysilanes of the formula (IV)         R73-hR4hSi(SiR52)iSiR4jR73-j     (IV), where R7 as above is a hydrolysable group and R4, R5, h, i and j have the same definitions as stated above, and / or organyl-bridged silicones of the formula (V)         R73-aRaSiY(SiRaR73-a)b     (V), where R7, R, Y, a and b have the definition already stated, with water and, if at least one of the hydrolysable radicals R7 is not a halogen radical, using catalytic amounts of one or more acids which promote the hydrolysis and condensation of the components of formulae (III), (IV) and (V), in the presence of a non-water-miscible, aprotic solvent, where, after reaction has taken place, both the water and the remaining amount of acid in the organic phase are reduced to less than 10 000 ppm each, and in a second step reacting the reaction product from the first step, in solution in the inert organic solvent, without water, with a halosilane of the formula (VI)         R33SiR8     (VI), where R3 has the same definitions as indicated above and R8 is a halogen atom, in the presence of an auxiliary base.

2. Process according to Claim 1, wherein the radicals R, R1, R2, R3, R4 and R5 are selected from methyl, phenyl, vinyl, acryloyloxy and methacryloyloxy radicals and also the acrylic esters or methacrylic esters of unbranched or branched alcohols having 1 to 15 carbon atoms.

3. Process according to either of the preceding claims, wherein the aprotic solvent is an aromatic hydrocarbon.

4. Process according to any of the preceding claims, wherein the auxiliary base is used in at least equimolar amount relative to the halosilane.

5. Process according to any of the preceding claims, wherein the auxiliary base is selected from basic metal salts and nitrogen compounds.

6. Process according to any of the preceding claims, wherein the polyorganosiloxanes of the formula (I) in a third step are joined to a metal substrate.

7. Process according to Claim 6, wherein the polyorganosiloxanes of the formula (I) in a fourth step are crosslinked.

8. Metal-clad laminates producible by a process according to Claim 6 or 7, wherein in the second step the halosilane of the formula (VI) is used so that the amount of halide radicals present is equimolar to the silanol radicals in the polyorganosiloxane species from the first reaction step.