Hardenable condensation compounds based on alkoxyfunctional polysiloxanes

Description

[0001] The invention relates to curable condensation compounds based on alkoxy-functional polysiloxanes, their manufacturing processes and their use in coating systems which, among other things, have a dirt-repellent property.

[0002] Coatings are applied to surfaces for decorative, functional, or protective purposes. The demand for surface protection is steadily increasing in various industrial sectors, such as aircraft, automotive, rail vehicles, shipbuilding, and wind energy.

[0003] Various technologies are used in the functionalization of surfaces and coatings. The approach of surface functionalization through micro- and nanostructuring of coatings, derived from the scale structure of sharks, is well-known from the literature. Such surfaces are used on components of ships, aircraft, wind turbine rotor blades, and pipelines to reduce drag. Self-healing coatings have also been developed, in which encapsulated functional agents are released when the system is mechanically damaged and then exert their healing effect. These self-healing surfaces are of interest for corrosion protection.

[0004] Another well-known problem is vandalism, such as graffiti on walls or objects. This problem affects not only municipalities but also, and especially, transport companies, as cleaning such surfaces is very time-consuming and expensive.

[0005] Considerable effort has been invested in developing graffiti removal techniques. One common technique involves abrading the surface with a paint remover such as methylene chloride, benzene, or toluene. Depending on the substrate, temperature, paint type, and exposure time, the paint is removed using, for example, a pressure washer. This process may need to be repeated several times. Any remaining graffiti can then be removed by sandblasting, which may require refinishing the surface to restore its original appearance. Another technique involves the time-consuming process of repainting or recoating the surface, which can also be very expensive.

[0006] Furthermore, antifouling coatings or foul-release coatings are known to prevent or at least significantly hinder the growth of algae and barnacles on surfaces in constant contact with water. Particularly on structures exposed to permanent water exposure, such as ship hulls, buoys, fishing nets, cooling ducts and discharge pipes, offshore drilling rigs, or water tanks exposed to seawater and / or freshwater, the adhesion and growth of organisms (biofouling) causes considerable economic losses. In the case of ships, these losses result, for example, from increased friction and the associated increase in fuel consumption. Surfaces of static structures also suffer mechanical damage due to increased resistance to waves or currents, leading to shorter maintenance cycles and thus reduced operating time.

[0007] Foul-release coatings are often based on polysiloxanes or silicone elastomers whose mechanism of action consists of forming a non-stick surface to which aquatic organisms cannot adhere, or where the adhesive forces are so low that they are detached by movement in the water.

[0008] It is therefore known to add polysiloxanes to coatings to achieve specific properties. For example, by chemically modifying the polydimethylsiloxane chain, key silicone properties such as compatibility, slip resistance, and scratch resistance can be controlled. The applications of polysiloxanes are wide-ranging and multifaceted.

[0009] Since the beginnings of the silicone industry, condensation-curable hydroxy- and / or, in particular, alkoxy-terminated, but also acetoxy-functional polydiorganosiloxanes have been of paramount importance as typical representatives of silicone resin precursors. The teaching of EP 0 157 318 B1 thus aims at a process for the production of silicone resin precursors of the general formula R 2< a Si(OR 1< ) b O (4-ab) / 2, which are obtained by alcoholysis / hydrolysis and partial condensation of organochlorosilanes with alcohol / water.

[0010] DE 21 16 816 A1 describes vulcanizable silicone rubbers, wherein alkoxyacetoxysiloxanes produced from a silane mixture consisting of ethyltriacetoxysilane, methyltriacetoxysilane and tetraethoxysilane are used.

[0011] CN105131293 B discusses acetoxy-functionalized MQ resins and their production. Accordingly, in a hydrolysis medium consisting of dilute hydrochloric acid and ethanol, hexamethyldisiloxane and tetraethoxysilane are first reacted to form an ethoxy-functional silicone resin prepolymer, which is then modified in a second step by reaction with an organoacetoxysilane to create a self-crosslinking acetoxy-MQ resin.

[0012] Clarke's work (US 3,032,529), which describes stabilized organopolysiloxane resins, takes a similar approach. Aimed at producing storage-stable silicone coating systems for wood, plastic, metal, and ceramic surfaces that cure within 24 hours at room temperature, the work teaches the acylation of pure and / or mixed, incompletely condensed β-Si-OH-terminated diorganosiloxanes with acylating agents, preferably triacyloxysilanes, to remove all Si-bound hydroxyl groups.

[0013] Without focusing on the use of acetoxysiloxanes, US 4,585,705 (Broderick et al.) deals with organopolysiloxane-based, substrate-curable release coatings, which incorporate hydroxy-functional methyl, phenyl and mixed methyl-phenyl resins alongside a methyltrimethoxysilane (derivative), and also small amounts of trimethylsilyl-end-blocked diorganosiloxanes and titanate esters.

[0014] Also known is the linkage of terminal hydroxy-functional siloxanes (PDM-siloxanes) with a multifunctional acetoxysilane as a crosslinker to hydrolytically unstable siloxane prepolymers containing acetoxy groups (HF Mark, Concise Encyclopedia of Polymer Science and Technology, 3rd Edition, page 1112, Wiley-Verlag, (2013) and also in AS Hoffman et al., Biomaterials Science: An Introduction to Material in Medicine, 2nd Edition, pages 83 - 84, Elsevier Acad. Press, San Diego, (2004)).

[0015] In US 2009 / 0226609, Boisvert et al. claim Q-titanium-based silicone resins that are produced by reacting a system of substances consisting of di-(t-butoxy)diacetoxysilane, tetrahydrofuran, water and tetra(t-butoxy)titanium.

[0016] According to C. Robeyns et al. (Progress in Organic Coatings 125, pp. 287-315, (2018)), the process begins with a hydrolysis of the di-(t-butoxy)diacetoxysilane to form ortho-silica Si(OH)4, which then condenses with tetra(t-butoxy)titanium to form the mixed titanium-silicone resin, releasing 4 equivalents of t-butanol.

[0017] However, the use of titanates is problematic due to their tendency to decompose in the presence of water, as this leads to the formation and precipitation of insoluble tetravalent titanium hydroxide, which causes turbidity, especially in coating systems. This is particularly true for systems where hydrolysis is carried out in the presence of titanates. To overcome this problem, especially in the production of anti-abrasive coating systems for transparent polycarbonate, Leclaire (US 5,357,024) proposes reacting an alkoxysilane hydrolysate possessing condensable αSiOH groups with an acyltitanate compound, followed by the addition of water in a dilute solution. This results in a siloxane prepolymer containing titanium bound within it in the range of 20 to 30 wt% TiO₂ based on the solid state. Leclaire obtains the acyltitanate compounds by reacting tetraalkyl titanates or...Tetraalkoxytitanium compounds react in non-aqueous solvents, such as alcohols with carboxylic acids.

[0018] Leclaire did not observe the formation of precipitates in the coating matrices when using these hydrolyzable titanium compounds, even when the hydrolysis of the silanes occurred under harsh conditions. Leclaire interprets this observation by suggesting that the acyloxy group(s) bound in the titanium compound reduces its reactivity.

[0019] US 5,357,024 further teaches that these acyl titanates are obtained starting from tetraalkyl titanates by substituting the alkoxy groups with acyloxy groups. The preparation is carried out in the absence of water by reacting a tetraalkoxytitanium or a tetraalkyl titanate of the formula Ti(OR')₄, in which the R' groups may be the same or different, with a carboxylic acid RCOOH. The amount of acid used for this reaction is selected according to the number of alkoxy groups to be substituted, in amounts ranging from 1 to 4 equivalents of acid to 1 equivalent of tetraalkoxytitanium. The reaction is preferably carried out in the presence of a suitable non-aqueous solvent, e.g., an alcohol such as isopropanol.

[0020] Seeking a silanic AB3-type precursor for the synthesis of hyperbranched polyethoxysiloxanes, Jaumann et al. (Macrol. Chem. Phys. 2003, 204, 1014-1026) describe the reaction of tetraethoxysilane with acetic anhydride at 137°C for at least 36 hours (even requiring 89 hours in M. Jaumann's dissertation, 04.09.2008, RWTH Aachen, p. 47). This reaction yields acetoxytriethoxysilane as an AB3-type precursor in yields of only about 39%, releasing ethyl acetate. Attempting to improve the unsatisfactory reaction kinetics, Jaumann also uses tetraethyl orthotitanate as a catalyst in both low and high doses. With the addition of 0.155 mol% tetraethyl orthotitanate, the reaction time, which then proceeds with approximately 94% conversion, is reduced to 14.5 hours. An addition of 0.95 mol% tetraethyl orthotitanate, at approximately 88% conversion, shortens the reaction time to 1.5 hours, but with a significant loss of product purity.In the polyethoxysiloxane obtained from this process, approximately 6 mol% of all Si atoms originate from the tetraethoxysilane used (Dissertation M. Jaumann, 04.09.2008, RWTH Aachen pp. 47-50).

[0021] Similarly reflecting Jaumann's work, WO 2014 / 187972 claims the use of fluorine-free, highly branched polyalkoxysiloxanes for the production of dirt-repellent surface coatings with a branching degree of VG > 0.4 according to a complex calculation formula incorporating < 29< µS NMR spectroscopy. The highly branched polyalkoxysiloxane is prepared with tetraethoxysilane, acetic anhydride, and tetrakis(trimethylsiloxy)titanium; or with Dynasylan® < 40, acetic anhydride, and titanium 4-isopropoxide; or with Dynasylan® < 40, acetic anhydride, and α-n-butyl-ω-trimethoxysilyl-ethyl-polydimethylsiloxane.

[0022] Not referring to polyalkoxysiloxanes, the teaching of WO 2019 / 200579 aims at a polysiloxane composition for the production of a room temperature crosslinking, non-corrosive elastomer containing a hydroxyl-terminated polyorganosiloxane, a diacetoxysilane, a multi-functional alkoxysilane, as well as a filler and a catalyst.

[0023] WO 2012 / 040305 discloses a curable composition containing organosiloxane block copolymers with a weight-average molecular weight Mw above 20,000 g / mol, which are generated by the reaction of silanol-bearing organosiloxane resins (component b) with linear geminal diacetoxy-substituted organosiloxanes (component a). "Geminal diacetoxy-substituted" here means that the organosiloxane has two adjacent acetoxy groups [-Si-(OAc)2] terminally attached to a silicon atom. These geminal diacetoxy-substituted organosiloxanes are produced by the reaction of silanol-terminated polydiorganosiloxanes with alkyltriacetoxysilanes. This process thus leads to multiple crosslinks around the center of the acetoxysilane used. The acetic acid formed during this process must be removed from the system.Separating the released acetic acid is difficult because it forms hydrogen bonds that hinder its thermal decomposition. Ensuring the absence of acid (and water) in the linear organosiloxane block copolymer is essential; otherwise, its use on acid-sensitive substrates is not possible. Furthermore, a solvent is required for its preparation, as the starting materials, namely the silsesquioxanes, are solid.

[0024] The object of the present invention is therefore to provide compounds suitable for the production of coating systems, wherein these have an improved anti-adhesive effect without significantly impairing the other properties and without exhibiting the disadvantages mentioned in the prior art.

[0025] To solve the problem, condensation compounds of the type mentioned above are proposed, which are achieved through the implementation of end-equilibrated acetoxy group-bearing siloxanes according to formula (I) and / or formula (II): where R = an alkyl group with 1 to 4 carbon atoms and / or a phenyl group, preferably R = a methyl group and 1 ≤ x ≤ 500, preferably 3 ≤ x ≤ 100, particularly preferably 5 ≤ x ≤ 40, or where 0 ≤ a ≤ 100 and 1 ≤ b ≤ 10, preferably with 2 ≤ a ≤ 30 and 1 ≤ b ≤ 6, particularly preferably with 3 ≤ a ≤ 10 and 2 ≤ b ≤ 5, with at least one alkoxy-functional polysiloxane according to formula (III) R 1< c Si(OR 2< ) d O (4-cd) / 2 formula (III) wherein c is greater than or equal to 0 but less than or equal to 2 and d is greater than or equal to 0 but less than or equal to 4 and the sum of c + d is less than 4, R 1< is independent, identical or different linear or branched, saturated as well as mono- or polyunsaturated or aromatic hydrocarbon residues, and R 2< is an alkyl group consisting of 1 to 8 carbon atoms, preferably a methyl or ethyl group, in the presence a catalyst, are available.

[0026] It has been found that the curable condensation compounds according to the invention can be used to produce coating systems with anti-adhesive properties, in particular with anti-graffiti effects. Furthermore, the coatings produced therefrom surprisingly exhibit better lubricity than conventional coatings.

[0027] The tests showed that the coatings produced with the curable condensation compounds according to the invention prevent or reduce dirt adhesion of any kind and do not impair other properties.

[0028] The various fragments of the siloxane chains specified in formulas (I) to (III) can be statistically distributed. Statistical distributions can be block-based with any number of blocks and any sequence, or subject to a randomized distribution; they can also be alternating or form a gradient along the chain; in particular, they can also form any combination thereof.

[0029] The index numbers and value ranges of the specified indices shown here can be understood as mean values ​​of the possible statistical distribution of the actual existing structures and / or their mixtures.

[0030] In the context of this invention, the term "poly" encompasses not only compounds with at least three repeating units of one or more monomers in the molecule, but also, in particular, compositions of compounds that exhibit a molecular weight distribution and have an average molecular weight of at least 200 g / mol. This definition takes into account the fact that, in the relevant field of technology, it is common practice to refer to such compounds as polymers, even if they do not appear to meet a polymer definition analogous to OECD or REACH directives.

[0031] Unless otherwise stated, percentages are given as weight percentages.

[0032] If measured values ​​are given below, these measurements were carried out under standard conditions (25 °C and 1013 mbar), unless otherwise stated.

[0033] Unless otherwise stated, where average values ​​are given below, they are weight averages.

[0034] Particularly suitable end-equilibrated acetoxy group-bearing siloxanes according to formula (I) and / or formula (II) and their preparation are known from the prior art. Accordingly, it is possible, for example, to obtain a terminal acetoxy group-bearing, linear or branched polysiloxane by reacting a terminal alkoxy group-bearing, linear polysilicone equilibrate (=pre-equilibrate) as the sole reactant with a reaction medium consisting of acetic anhydride, trifluoromethanesulfonic acid, and acetic acid.

[0035] Numerous synthesis methods are known to those skilled in the art. A few, which are also intended to be components of this invention, are mentioned here: It is conceivable to use trifluoromethanesulfonic acid, equilibrated acetoxysiloxanes of the linear or branched structural type according to formula (I) or formula (II), the preparation of which can be derived from the teaching of European patent application EP 3611215A1, according to which cyclic siloxanes, in particular comprising D4 and / or D5, and / or mixtures of cyclically branched siloxanes of the D / T type are reacted with acetic anhydride and with the addition of acetic acid, using trifluoromethanesulfonic acid as a catalyst.

[0036] The European patent applications with application numbers EP 18189072.4, EP18189075.7 and EP 18189074.0 relate to processes for the production of acetoxy-modified siloxanes, in which DT siloxane cycles or simple siloxane cycles containing only D units are used as starting materials.

[0037] Aiming for linear SiOC-linked silicon polyether structures rather than branched ones, the European patent applications with application numbers EP 18189072.4 and EP 18189074.0 state that equilibrated α,ω-diacetoxy-polydimethylsiloxanes are produced by reacting siloxane cycles (D4 / D5) with acetic anhydride in the presence of trifluoromethanesulfonic acid, by thoroughly mixing the reactants, applying 0.1 to 0.3 mass percent trifluoromethanesulfonic acid based on the total reaction mass, and then heating to temperatures of 140 to 160°C for a period of 4 to 8 hours. In this process, a clear, equilibrated trifluoromethanesulfonic acid-catalyzed α,ω-diacetoxy-polydimethylsiloxane is obtained from the initially slightly cloudy reaction mixture, which, in addition to the trifluoromethanesulfonic acid used, also contains 0.125 mol of free acetic anhydride based on the acetic anhydride equivalent chemically bound in the α,ω-diacetoxy-polydimethylsiloxane.

[0038] The European patent application with application number EP18210035.4 describes (i) reaction systems for the preparation of acetoxy group-bearing siloxanes, comprising (a) alkoxy group-bearing silanes and / or siloxanes and / or (b) acetoxy group-bearing silanes and / or siloxanes, (c) hydroxy group-bearing silanes and / or siloxanes, (d) optionally simple siloxane cycles and / or DT cycles, (i) a reaction medium comprising acetic anhydride, perfluoroalkanesulfonic acid and preferably acetic acid, (ii) a process for the preparation of linear or branched acetoxy group-bearing siloxanes.

[0039] The branched siloxanes to be used according to the invention, which are provided with terminal acetoxy groups, are accessible, for example, by processes described in the unpublished patent applications with application numbers EP 19176875.3 and EP 19176874.6, respectively. These processes start with cyclic branched siloxanes of the D / T type, which in a first step are reacted under acid catalysis with acetic anhydride, optionally in mixture with simple siloxane cycles and / or hydroxy-bearing siloxanes and / or acetoxy- and / or alkoxy-bearing silanes and / or siloxanes, to form acetoxy-bearing, branched siloxanes. These are then equilibrated in a second step with acids, preferably superacids, particularly with the addition of acetic acid. The cyclic branched siloxanes of the D / T type are mixtures of cyclic branched siloxanes of the D / T type. which, in addition to D and T units, may contain siloxanes.also contain siloxanes with Q units, provided that in these mixtures the proportion of Si atoms originating from Q units is ≤ 10 wt% to ≥ 0 wt%, preferably ≤ 5 wt% to ≥ 0 wt%, based on the total of all Si atoms, wherein application EP 19176875.3 further stipulates that if the cyclic branched siloxanes of the D / T type used are mixtures of cyclic branched siloxanes of the D / T type that do not contain siloxanes with Q units, the acid(s) used in step 1 and / or 2 is not solely trifluoromethanesulfonic acid or solely trifluoromethanesulfonic acid and acetic acid.

[0040] Preferably, the end-equilibrated acetoxy group-bearing siloxanes according to formula (I) have exclusively D units.

[0041] Preferably, end-equilibrated α,ω-acetoxy group-bearing, linear polydimethylsiloxanes are used for the reaction.

[0042] Preferably, end-equilibrated acetoxy group-bearing siloxanes are neutralized according to formula (I) and / or formula (II).

[0043] The neutralization of Brønsted acidic, and in particular trifluoromethanesulfonic acid, acetoxysiloxanes is described in patent application EP 19176868.8. For this purpose, the acetoxysiloxane to be neutralized is treated with an amount of a solid and / or liquid and / or gaseous base sufficient to neutralize the Brønsted acid, in particular trifluoromethanesulfonic acid, contained therein, and the neutralized acetoxysiloxane is separated from the salt formed. To ensure neutralization, the base used for neutralization is preferably employed in a stoichiometric excess relative to the acid equivalent to be neutralized.

[0044] Acetoxysiloxanes and siloxanes containing acetoxy groups are used synonymously here.

[0045] Suitable alkoxy-functional polysiloxanes according to formula (III) are also frequently referred to as silicone resins. This formula represents the smallest unit of the average structural formula of the silicone polymer. The number of repetitions is determined by the number-average Mn value as calculated via GPC.

[0046] The production of such silicone resins has long been known in the literature (see W. Noll - Chemie und Technologie der Silicone, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 1960) and is also described in the German patent DE 34 12 648.

[0047] Preferably, the residues R1< are independently saturated, branched, or unbranched alkyl groups with 1 to 17 carbon atoms and / or mono- or polyunsaturated, branched, or unbranched alkenyl groups with 2 to 17 carbon atoms, or aromatic groups with 6 to 12 carbon atoms. Particularly preferably, the alkyl and alkenyl groups have up to 12, and more preferably, up to 8 carbon atoms. Also particularly preferred are all residues R1< being methyl and / or phenyl.

[0048] Preferably, the R2< groups are independently saturated, branched, or unbranched alkyl groups with 1 to 8 carbon atoms. Preferably, R2< is selected from methyl or ethyl groups. The latter are particularly suitable for HAPS-free (Hazardous Air Pollutant Substance) phenylpolysiloxanes or phenylalkylpolysiloxanes, which contain neither solvents such as toluene, xylene, or benzene and, moreover, release only ethanol, not methanol, during the catalytic hydrolysis-condensation crosslinking that takes place at room temperature.

[0049] Preferred compounds of general formula (III) have as residue R 2< methyl and / or ethyl groups with 3 to 50 wt.% alkoxy functionality, preferably 5 to 40 wt.%, and particularly preferably 7 to 30 wt.%, based on the total mass of the compound.

[0050] The weight-average molecular weight Mw of the compound of general formula (III) is preferably 200 to 20,000 g / mol, particularly preferably 200 to 10,000 g / mol, further preferably 300 to 3,000 g / mol or particularly preferably 400 to 2,000 g / mol.

[0051] The alkoxy functionality of the polysiloxanes of general formula (III) plays a major role in the implementation according to the invention.

[0052] Alkoxy functional in the sense of the present invention means that alkyl groups are bonded to silicon via oxygen in the polysiloxane. Preferably, alkoxy functional means the presence of Si-OR groups. The alkoxy functionality indicates the mass fraction of alkoxy groups relative to the polysiloxane.

[0053] It should be noted that the use of alkoxy-functional polysiloxanes of formula (III) proves advantageous compared to the use of the silanols listed in the prior art. The storage stability of αSiOH-group-bearing siloxanes is very limited, especially under the influence of ubiquitous traces of acids or bases. Furthermore, the silanol-functional polysiloxanes typically used for coating systems are generally solid and always require a solvent for processing, either for further functionalization or application. Once applied to a substrate, silanol-group-bearing polysiloxanes are less reactive compared to alkoxy-group-bearing systems and require high temperatures for cross-linking to occur. Therefore, silanol-functional polysiloxanes cannot be used on temperature-sensitive substrates.Silanol-functional polysiloxanes are therefore unsuitable for outdoor applications on non-heatable substrates, such as for an anti-graffiti coating.

[0054] Preferred are the polysiloxanes of general formula (III) with R 1< equal to methyl, so-called methyl silicone resins, with an alkoxy functionality of 7 to 35 wt.% based on the total mass of the polysiloxanes and a weight-average molar mass of 300 to 2,000 g / mol.

[0055] Also preferred are the polysiloxanes of general formula (III) with R 1 < equal to phenyl, so-called phenyl resins. They preferably have a proportion of alkoxy groups of 1–40 wt.%, based on the polysiloxane, particularly preferably 3–35 wt.%, and most preferably 5–30 wt.%.

[0056] Furthermore, the weight-average molecular weight Mw of the phenyl resins is preferably 200 to 10,000 g / mol, preferably 200 to 3,000 g / mol, particularly preferably 300 to 2,000 g / mol.

[0057] The weight-mean molecular weight Mw of the phenyl resins is particularly preferred to be between 700 and 2,000 g / mol.

[0058] In another embodiment, the polysiloxanes of general formula (III) with R 1< equal phenyl and methyl groups are preferred, so-called methyl-phenyl resins.

[0059] Particularly preferred methyl phenyl resins have methoxy and / or ethoxy groups as alkoxy groups, wherein the proportion of the alkoxy groups, in particular the methoxy or ethoxy groups, is at least 1 wt.% based on the polysiloxane, preferably 2 to 40 wt.%, particularly preferably 3 to 35 wt.%, and most preferably 5 to 30 wt.%.

[0060] The numerical phenyl to methyl ratio based on the number of moles in the resin is preferably in the range of 1 to 0.1 to 0.1 to 1, preferably in the range of 0.5 to 1 to 1 to 0.5.

[0061] If chemical (sum) formulas are used in the present invention, the indicated indices can represent both absolute numbers and average values.

[0062] For polymeric compounds, the indices preferably represent mean values.

[0063] Unless otherwise stated, percentages are given as weight percentages.

[0064] If measured values ​​are given below, these measurements were carried out under standard conditions (25 °C and 1013 mbar), unless otherwise stated.

[0065] Unless otherwise stated, where average values ​​are given below, they are weight averages.

[0066] Preferably, for the production of the condensation compounds according to the invention, a catalyst is selected from tin diacetate, tin dioctoate, dibutyltin diacetylacetonate, dibutyltin dilaurate, tin tetraacetate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dioleate, dioctyltin dilaurate, dioctyltin dineodecanoate, dimethoxydibutyltin, dimethyltin, dibutyltin benzyl maleate, bis-(triethoxysiloxy)dibutyltin, diphenyltin diacetate, tetraethoxytitanium, tetra-n-propoxytitanium, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetra-i-butoxytitanium, tetrakis-(2-ethylhexoxy)titanium, di-i-propoxy-bis(ethylacetoacetate)titanium, dipropoxy-bis-(acetylacetonate)titanium. Di-i-propoxy-bis-(acetylacetonate)-titanium, dibutoxy-bis-(acetylacetonate)-titanium, tri-i-acetate-propoxyallyl-titanium, isopropoxyoctylene glycol or bis(acetylacetonate)-titanium oxide, lead diacetate, lead di-2-ethylhexanoate, lead dineodecanoate, lead tetraacetate, lead tetrapropionate, zinc acetylacetonate, zinc 2-ethylcaproate, zinc diacetate, bis-(2-ethylhexanoic acid)-zincZinc dineodecanoate, zinc diundecenoate, zinc dimethacrylate, tetrakis-(2-ethylhexanoic acid) zirconium dichloride, tetrakis-(methacrylic acid) zirconium dichloride, cobalt diacetate, bismuth carboxylates, and bismuth triflate. Furthermore, iron(II) and iron(III) compounds, e.g., iron(III) acetylacetonate or iron(II) acetate, aluminum compounds, e.g., aluminum acetylacetonate, calcium compounds, e.g., calcium ethylenediaminetetraacetate, and magnesium compounds, e.g., magnesium ethylenediaminetetraacetate, can also be used as catalysts.

[0067] It is also conceivable to use perfluoroalkanesulfonic acid, such as trifluoromethanesulfonic acid or perfluorobutanesulfonic acid, as a catalyst.

[0068] Preferably, a catalyst according to the invention, which will be described and explained in more detail below, can be used.

[0069] Preferably, at least one crosslinker according to formula (IV) R 3< e Si(OR 4< ) f formula (IV) is used in the implementation. where e is greater than or equal to 0 to less than or equal to 2, f is greater than or equal to 2 to less than or equal to 4 and the sum of e + f is equal to 4, R 3< = a saturated or unsaturated alkyl group consisting of 1 to 8 carbon atoms, or an organic group consisting of 1 to 8 carbon atoms and 1 to 2 nitrogen atoms or an aromatic group with 6 to 20 carbon atoms and R 4< = an alkyl or acyl group consisting of 1 to 8 carbon atoms is present.

[0070] Alkyl groups are preferably methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, or t-butyl groups. The aromatic group is preferably a phenyl group. Preferred substituents R<3 are methyl or phenyl groups, or mixtures of methyl and phenyl groups. Preferred alkyl groups of R<4 are methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, or t-butyl groups.

[0071] Preferably, the crosslinker is selected from methyltriacetoxysilane, ethyltriacetoxysilane, dimethyldiacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethoxyphenylmethylsilane and diethoxyphenylmethylsilane.

[0072] Advantageously, the method according to the invention makes it possible to increase the degree of branching of the condensation compounds by a) branched acetoxysiloxane and / or b) a branching crosslinker of the reaction matrix, adds.

[0073] Furthermore, according to the invention, a downstream crosslinking option with a concomitant increase in molar mass is available by reacting the branched condensation compounds with additional acetoxysiloxanes.

[0074] The terms "siloxanes" and "polysiloxanes", whether used as part of a word or on their own, are understood as synonyms in the present invention.

[0075] Preferably, the curable condensation compounds according to the invention contain the crosslinking agent in amounts of 0 to 20 wt.%, preferably 0 to 10 wt.% and particularly preferably 0 to 5 wt.% based on the total mass of the curable condensation compounds.

[0076] Furthermore, it is desirable to provide a method with which curable condensation compounds based on alkoxy-functional polysiloxanes can be produced easily and without the disadvantages known from the prior art.

[0077] Surprisingly, it has now been found that, without the aforementioned use of organochlorosilanes and without difficult-to-control alcoholysis / hydrolysis processes, it is possible to obtain simple and unambiguous hardenable condensation compounds based on alkoxy-functional, =Si-OH-group-free polysiloxanes by reacting end-equilibrated acetoxy-group-bearing siloxanes according to formula (I) and / or formula (II) with at least one alkoxy-functional polysiloxane according to formula (III) in the presence of a catalyst.

[0078] Preferably, the ratio of acetoxy group-bearing siloxanes according to formula (I) and / or formula (II) to alkoxy-functional polysiloxanes according to formula (III) is 1 wt.% to 99 wt.%, up to 99 wt.% to 1 wt.%, preferably 3 wt.% to 97 wt.% to 50 wt.% to 50 wt.%, and particularly preferably 5 wt.% to 95 wt.% to 30 wt.% to 70 wt.%, based on the total silicon matrix.

[0079] All common catalysts can be used. Preferred catalysts are described above.

[0080] Furthermore, it was surprisingly found that the process according to the invention is particularly preferably carried out in the presence of a silicon matrix compatible catalyst, which can be obtained, for example, before the start of the condensation reaction to be catalyzed by reacting titanium alcoholates with acetic anhydride or titanium alcoholates with acetoxysiloxanes.

[0081] Reaction matrix and total silicon matrix are used here as synonyms, which essentially consist of compounds of formula (I) or (II) and compounds of formula (III).

[0082] In particular, the catalyst obtained according to the invention from the reaction of titanium alcoholates with acetoxysiloxane can also preferably be produced in situ.

[0083] Thus, the preparation of the novel catalyst constitutes a further object of the invention. The catalyst according to the invention can preferably be prepared from titanium alkoxides with acetic anhydride or from titanium alkoxides with acetoxysiloxanes. Particularly preferably, the catalyst according to the invention can be prepared from titanium alkoxides and acetoxysiloxane in situ, i.e., during the reaction of compounds of formula (I) or (II) with compounds of formula (III).

[0084] The catalyst resulting from the reaction of titanium alkoxides with acetoxysiloxanes has excellent compatibility with the reaction matrix and allows both the timely and rapid reaction of alkoxypolysiloxanes with acetoxysiloxanes and the curing of the resulting curable condensation compounds in ordinary atmosphere.

[0085] According to a preferred embodiment, acetoxysiloxane and alkoxy-functional polysiloxane can first be premixed and then treated with titanium alkoxide and / or, more preferably, with the condensation catalyst resulting from the reaction of acetoxysiloxane with titanium alkoxide.

[0086] Alternatively, preferably according to the invention, a condensation catalyst compatible with the silicone matrix can be produced by mixing and pre-reacting acetoxysiloxane with titanium alkoxide. The addition of the alkoxy-functional polysiloxane then yields the condensation-capable reaction matrix.

[0087] Within the scope of the present invention, the compatibility of the condensation catalyst is determined by the presence or absence of turbidity after its introduction into, or after its in-situ formation in, the reaction matrix. If a volume aliquot taken from the reaction matrix for this purpose is placed in a 10 mm thick glass cuvette, and text immediately behind it (written in black, Arial 12 font size on white paper) can then be read without distortion under daylight and / or artificial light, the reaction matrix is ​​considered free of turbidity and the condensation catalyst is considered compatible with the invention.

[0088] In a further, preferred embodiment according to the invention, acetoxysiloxane, alkoxypolysiloxane and titanium alkoxide are reacted under intensive mixing.

[0089] According to the invention, all the catalysts mentioned can be used in amounts of 0.01 to 10.0 wt.%, preferably 0.05 to 7.5 wt.%, particularly preferably 0.1 to 5.0 wt.% based on the reaction matrix consisting of alkoxypolysiloxane and acetoxysiloxane.

[0090] The alkoxy-functional polysiloxanes according to formula (III) and end-equilibrated acetoxy group-bearing siloxanes according to formula (I) and / or formula (II), including their preferred embodiments, used for the process according to the invention are described in more detail above.

[0091] According to the invention, to complete the condensation reaction, the acetic acid ester formed from the R2< residue and the acetoxy group can preferably be removed during the reaction. The removal of the acetic acid ester released from the reaction matrix can be carried out at normal pressure or, particularly preferably, at reduced pressure, i.e., by applying an auxiliary vacuum. Other possibilities are known to those skilled in the art.

[0092] According to the invention, the condensation reaction of alkoxy-functional polysiloxanes with acetoxysiloxanes can preferably be carried out either in the substance, i.e., without the use of solvents, or in solution. Suitable solvents include, for example, aromatics, alkyl aromatics, and aliphatic hydrocarbons.

[0093] Preferably, solvents are used which have a boiling point that is higher than the boiling point of the acetic acid ester released from the condensation reaction, formed from the residue R 2< and the acetoxy group.

[0094] Condensation reaction and conversion are used synonymously here.

[0095] A crosslinker of formula (IV) is preferably used. Preferred crosslinker compounds are described above.

[0096] It is conceivable that the crosslinking agent is used as a mixture consisting of at least two crosslinking agents. For example, a mixture of phenyltrimethoxysilane and methylphenyldimethoxysilane can be used as a monomer blend in accordance with the present invention.

[0097] 293Si NMR spectroscopy (measured on a Bruker Avance III 400 spectrometer with a Bruker PA BBO 400Si BB-HD-10 z probe, at a frequency of 79.495 MHz, a measurement time of 2.569 seconds per scan, and 512 scans per spectrum), supplemented by GPC, can be used for reaction monitoring. In particular, 293Si NMR spectroscopy enables conversion control by tracking the characteristic signal for the Si-acetoxy group.

[0098] Taking the disappearance of the 29< Si NMR signal typical for acetoxysiloxanes at -9 ppm as a reliable indicator of complete conversion, for example, the reaction approaches according to the invention shown in the examples achieve quantitative conversion after 1 to 3 hours.

[0099] The curable condensation compounds obtained according to the invention have the significant advantage that they contain no proportions of siloxanes bearing =Si-OH groups. The deficiencies arising in particular from the increased presence of =Si-OH groups in alkoxy-functional polysiloxanes have already been sufficiently discussed, for example, in WO 2014 / 187972, specifically for hyperbranched polyalkoxysilane additives with regard to their lack of storage stability (p. 8), as well as in patent specification EP 0771835 B1 with regard to their lack of storage stability (p. 4, lines 29-30), and in EP 0964020 B1 with regard to the insufficient stain resistance when the alkoxy-functional polysiloxane is processed in a coating compound (p. 3,

[0026] ).

[0100] The condensation compounds that can be cured according to the invention are preferably clear to slightly cloudy liquids that have a distinct molar mass increase compared to the starting materials used (formula (I), (II) and formula (III)), which can be easily verified using GPC analysis.

[0101] It was also found that the curable condensation compounds according to the invention possess a certain self-curing character ("1-K character") due to the catalyst component remaining in the system.

[0102] If even faster drying and curing times are desired, the addition of further curing catalysts is recommended. Common curing catalysts are known to those skilled in the art. For example, some are listed here: 3-Aminopropyltriethoxysilane, 3-Aminopropyltrimethoxysilane, Tetra(i-Propyl)titanate, Tetra(n-Butyl)titanate, 1,1,3,3-Tetramethylguanidine, 1,8-Diazabicyclo[5.4.0]undec-7-ene, 1,5-Diazabicyclo[4.3.0]non-5-ene, and dioctyltin dilaurate.

[0103] A further objective of the present invention was to provide coating materials with anti-graffiti properties that do not adversely alter the properties of the substrate. Thus, the paints or varnishes used to produce graffiti should no longer adhere to the substrate, or only very weakly, after being coated according to the invention with anti-graffiti properties. Furthermore, sprayed substrates should be easy to clean, so that, for example, water, cloths, surfactants, high-pressure cleaners, or mild solvents ("easy-to-clean") are sufficient. A complex cleaning procedure, as known from the prior art, should be avoided as far as possible.

[0104] It was surprisingly found that the coatings according to the invention withstand several cleaning cycles without losing their anti-graffiti effect, for example. Thus, the coatings according to the invention are far superior to those of the prior art in terms of their technical lifespan. For example, the user does not have to apply a new protective layer after every cleaning process, which represents an economic advantage.

[0105] Surprisingly, coated products with a coating containing the curable condensation compounds according to the invention exhibit anti-adhesive properties, anti-graffiti properties, anti-friction properties and / or antifouling properties.

[0106] The use of the curable condensation compounds according to the invention for the production of coatings with anti-adhesive properties, anti-graffiti properties, anti-friction properties and / or antifouling properties is also the subject of this invention.

[0107] Coatings, varnishes, paints, inks, coverings, sealants and adhesives are also available through the use of the curable condensation compounds according to the invention, which is a further subject of the invention.

[0108] It is known to those skilled in the art that coatings may also contain adhesion promoters such as aminosilanes, UV stabilizers, fillers, pigments, thixotropic agents such as pyrogenic silica, reactive diluents or crosslinkers such as silanes, solvents such as xylene, leveling agents, defoamers or accelerators.

[0109] The invention will be explained in more detail below using exemplary embodiments. methods Nuclear magnetic resonance (NMR)

[0110] The NMR spectra were measured using a Bruker Avance III 400 spectrometer. 29<Si NMR spectra were measured with a Bruker PA BBO 400Si BB-HD-10 z probe head at a frequency of 79.495 MHz. The measurement time was 2.569 seconds per scan, with 512 scans per spectrum. Gel permeation chromatography (GPC)

[0111] Molar masses and distributions are determined according to DIN 55672-1. The described method is not an absolute method. Rather, calibration is necessary, which is performed using commercially available, linear polystyrene standards characterized by independent absolute methods. Instrument: Agilent 1100 from Agilent Technology, column combination: SDV 1000 / 10000 Å, length 65.00 cm, temperature 30 °C, tetrahydrofuran as mobile phase, flow rate 1 ml / min, sample concentration 10 g / l. RI detector, evaluation against a polystyrene standard in the molar mass range of 162–2,520,000 g / mol. Anti-graffiti effect

[0112] a) The anti-graffiti effect is determined according to ASTM D7089-06. The condensation compounds according to the invention were applied to aluminum Q-panels using a 100 µm spiral squeegee. The coated sheets were dried for 24 hours.

[0113] The metal sheets were then half-coated with a commercially available, blue-pigmented nitrocellulose lacquer (FLT Handel & Service GmbH) using a spray can and left to dry for 24 hours. Afterward, the coated sheets were subjected to a water jet operating at a pressure of 5 bar until the blue lacquer could be completely removed. This typically takes a maximum of 5 minutes. Small traces of paint on the edges of the sheets are disregarded.

[0114] Here, it is checked whether the coating has an anti-graffiti effect or not.

[0115] b) The sheets that survived this first cycle were dried again and spray-painted and dried once more. The test was repeated with a water jet until the blue paint layer could no longer be removed.

[0116] The number of cycles indicates how many times a coating has survived the cleaning procedure before it no longer has an anti-graffiti effect.

[0117] The more cleaning cycles a coating can withstand, the more economical it is. Sliding resistance value G (cN)

[0118] A test method that measures frictional force has proven effective for measuring sliding properties. This method is performed using a Bluehill device from Instron.

[0119] In this test, a 500 g weight with a defined felt backing is pulled evenly across the painted surface by a pulling machine. The force required is measured with an electronic force transducer. The test is performed at a constant speed of 12 mm / sec and allows for reproducible measurement with high accuracy. For the test, a coating composition according to the invention, containing condensation compounds according to the invention, was applied to aluminum Q-panels using a 100 µm spiral squeegee and dried for 24 hours.

[0120] The smaller the sliding resistance value G (cN), the higher the sliding ability of the coating surface. Compatibility of the catalyst according to the invention

[0121] According to the invention, the compatibility of the condensation catalyst is determined by the occurrence or non-occurrence of turbidity after its introduction or after its in-situ formation in the reaction matrix.

[0122] If an aliquot taken from the reaction matrix for this purpose is placed in a 10 mm thick glass cuvette and a text immediately behind it (font: Arial, typeface: Standard, font color: black on white paper) can then be read without distortion under daylight and / or artificial light, the reaction matrix is ​​considered to be free of turbidity and the catalyst to be compatible with the invention. Further conditions

[0123] Where percentages are given within the scope of the present invention, they are, unless otherwise specified, percentages by weight. In the case of compositions, the percentages refer to the total composition, unless otherwise defined. Where mean values ​​are mentioned in the following examples, they are numerical averages, unless otherwise specified. Where measured values ​​are given below, they were determined, unless otherwise defined, at a pressure of 101325 Pa, a temperature of 23 °C, and an ambient relative humidity of approximately 40%. Materials and equipment

[0124] Decamethylcyclopentasiloxane, Dow acetic anhydride, Merck acetic acid, 100%, JT Baker trifluoromethanesulfonic acid, Alfa Aesar potassium acetate, Sigma-Aldrich polydimethylsiloxanediol, Wacker tetra-n-butyl titanate, ABCR tetraisopropyl titanate, ABCR toluene, Reininghaus Chemie Silikophen AC1000 (poly(methyltrimethoxysilane)), Evonik Industries V5000 (poly(phenyltriethoxysilane)), Evonik Industries Dowsil 3074 Intermediate, (methoxy-functional phenyl(methyl) silicone resin) Dow Dynasylan AMEO (3-aminopropyltriethoxysilane), Evonik Industries rotary evaporator Rotavapor R-300, Büchi oil bath Rotavapor B-300 Base, company. Büchi Standard glass strips, Gläserei Glänzer BK3 drying recorder, The Mickle Laboratory Engineering Q-Panels Aluminium, 6"x3", Q-Lab colored spray paint satin blue, FLT Handel & Service GmbH Examples 1. Production of the curable condensation compounds according to the invention 1.1 Production of end-equilibrated acetoxy group-bearing siloxanes

[0125] First, end-equilibrated α,ω-diacetoxypolydimethylsiloxanes, hereinafter referred to as α,ω-diacetoxysiloxanes for ease of reading, are prepared. These are synthesized by reacting siloxane cycles (D4 and / or D5) with acetic anhydride in the presence of trifluoromethanesulfonic acid and acetic acid, as disclosed in European patent applications EP18172882.5 and EP18172876.7. Following these documents, three α,ω-diacetoxysiloxanes A, B, and C with average siloxane chain lengths of approximately 10, 15, and 35 monomer units, respectively, are prepared. The acids contained in the α,ω-diacetoxysiloxanes are then neutralized with potassium acetate, and the precipitated salts are filtered off. To remove volatile components, the α,ω-diacetoxysiloxane is distilled for one hour at 130 °C under an auxiliary vacuum of 5 mbar. Table 1: α,ω-Diacetoxypolydimethylsiloxanes Average siloxane chain length α,ω-Diacetoxysiloxane A 10 α,ω-Diacetoxysiloxane B 15 α,ω-Diacetoxysiloxane C 35 1.2 Alkoxy-functional polysiloxanes

[0126] The alkoxypolysiloxanes listed in Table 2 are used. Table 2: alkoxypolysiloxane Manufacturer Silikophen AC1000 (Poly(methyltrimethoxysilane)) Evonik Industries V5000 (Poly(phenyltriethoxysilane)) Evonik Industries Dowsil 3074 Intermediate, (methoxy-functional phenyl(methyl) silicone resin) Dow company Example 1 (according to the invention):

[0127] In a 500 ml single-necked round-bottom flask, 100.0 g of Silikophen AC1000, 10.0 g of α,ω-diacetoxysiloxane B, and 0.5 g of tetraisopropyl titanate are placed together in a rotary evaporator with a heating bath (Rotavapor R-300) and then mixed at a heating bath temperature of 130°C for one hour at 100 rpm and ambient pressure. An auxiliary vacuum of 600 mbar is applied for two hours, followed by an auxiliary vacuum of 100 mbar for a further two hours. The methyl acetate formed during the reaction is collected in a receiving flask. A 29<Si NMR spectrum of the final product remaining in the bottom flask confirms, by the disappearance of the signal at -9 ppm, that the terminal acetoxy groups of α,ω-diacetoxysiloxane B have been completely converted.A GPC of the colorless, clear product shows a number-mean molecular weight M n of 894 g / mol and a weight-mean molecular weight M w of 4627 g / mol, thus demonstrating a significant increase in molecular weight compared to the starting material Silikophen AC1000 (M n 586 and M w 859 g / mol). Example 2 (according to the invention)

[0128] In analogy to Example 1, 400.0 g of Silikophen AC1000, 80.0 g of α,ω-diacetoxysiloxane B, and 2.5 g of tetra-n-butyl titanate are weighed into a 2000 ml single-necked round-bottom flask and reacted using a rotary evaporator. A 29<Si NMR spectrum of the final product shows, by the disappearance of the signal at -9 ppm, that the terminal acetoxy groups originating from α,ω-diacetoxysiloxane B have been completely converted. A GPC exhibits a number-mean molecular weight Mn of 884 g / mol and a weight-mean molecular weight Mw of 7767 g / mol, thus demonstrating a significant increase in molecular weight compared to the starting material Silikophen AC1000 (Mn 586 and Mw 859 g / mol). Example 3 (according to the invention)

[0129] In a 500 mL single-necked round-bottom flask, 100.0 g of Dowsil 3074 intermediate, 7.5 g of α,ω-diacetoxysiloxane A, and 0.4 g of tetraisopropyl titanate are weighed out. The reaction of this mixture is carried out analogously to Example 1. An almost colorless, slightly cloudy liquid is obtained. Due to the overlap of signals in the 29<Si NMR-relevant shift range, it is not possible to detect the reaction of the terminal acetoxy groups of α,ω-diacetoxysiloxane A using this method. However, a prepared GPC shows a number-mean molecular weight M n of 1492 g / mol and a weight-mean molecular weight M w of 2681 g / mol, thus demonstrating a significant increase in molecular weight compared to the starting material Dowsil 3074 Intermediate (with M n = 899 g / mol and M w = 1345 g / mol). Example 4 (according to the invention)

[0130] In a 500 ml single-necked round-bottom flask, 100.0 g of Dowsil 3074 intermediate, 10.0 g of α,ω-diacetoxysiloxane B, and 0.4 g of tetraisopropyl titanate are weighed out. The reaction of this mixture is carried out analogously to Example 1. An almost colorless, slightly cloudy liquid is isolated. Due to the overlap of signals in the 29<Si NMR-relevant shift range, it is not possible to detect the reaction of the terminal acetoxy groups of α,ω-diacetoxysiloxane B using this method. However, a prepared GPC shows a number-mean molecular weight M n of 1449 g / mol and a weight-mean molecular weight M w of 2801 g / mol, thus demonstrating a significant molecular weight increase compared to the starting material Dowsil 3074 Intermediate (with M n = 899 g / mol and M w = 1345 g / mol). Example 5 (according to the invention)

[0131] In a 500 ml single-necked round-bottom flask, 100.0 g of V5000, 10.0 g of α,ω-diacetoxysiloxane B, and 0.5 g of tetraisopropyl titanate are weighed out. The reaction of this mixture is carried out analogously to Example 1. A slightly yellowish, minimally cloudy liquid is isolated. A 29<Si NMR spectrum of the final product shows the complete conversion of α,ω-diacetoxysiloxane B by the disappearance of the signal characteristic of terminal acetoxy groups at -9 ppm. Additionally, a GPC of the final product demonstrates a number-mean molecular weight Mn of 1070 g / mol and a weight-mean molecular weight Mw of 1457 g / mol, thus showing a significant increase in molecular weight compared to the starting material V5000 (with Mn = 806 g / mol and Mw = 976 g / mol). 2. Preparation of a catalyst solution according to the invention and its use for the preparation of the curable condensation compounds according to the invention. Example 6 (according to the invention)

[0132] A catalyst solution consisting of 1.00 g tetraisopropyl titanate, 0.37 g acetic anhydride, and 2.00 g toluene was prepared. After the exothermic reaction subsided, the clear catalyst solution obtained in this way could be used directly.

[0133] By analogy to Example 1, 100.0 g of Silikophen AC1000, 10.0 g of α,ω-diacetoxysiloxane C, and 1.0 g of catalyst solution were weighed into a 500 ml single-necked round-bottom flask. An aliquot taken from the homogeneous reaction matrix was placed in a 10 mm thick glass cuvette, and text immediately behind it (font: Arial, font style: Standard, ink color: black on white paper) was legible without distortion under artificial light, so that the reaction matrix was assessed as turbid and the catalyst as compatible with the invention. After reintroducing the sample volume into the reaction mixture, it was heated to 130 °C on a rotary evaporator and the reaction was carried out. A 29< Si NMR spectrum of the final product shows, by the disappearance of the signal at -9 ppm, that the terminal acetoxy groups originating from α,ω-diacetoxysiloxane C were completely converted.A GPC exhibits a number-mean molecular weight M n of 831 g / mol and a weight-mean molecular weight M w of 2.893 g / mol, thus demonstrating a significant molecular weight increase compared to the starting material silikophen AC1000 (M n 586 and M w 859 g / mol). Example 7 (according to the invention)

[0134] In a 250 mL multi-necked flask, 6.0 g (0.0211 mol) of Ti(IV) isopropanolate were stirred in 50 g of toluene at 23°C. A solution consisting of 94.0 g of α,ω-diacetoxysiloxane B and 50 g of toluene was then added via a dropping funnel over 10 minutes. The clear reaction mixture was then heated to 80°C for one hour and subsequently evaporated at 70°C under a vacuum < 5 mbar using a rotary evaporator. The liquid residue is slightly yellowish and clear.

[0135] In a 250 mL four-necked flask, 50 g of Silikophen AC1000 (poly(methyltrimethoxysilane)) were placed under stir at 23°C, followed by 5 g of an end-equilibrated α,ω-diacetoxysiloxane B (neutralized with potassium acetate, filtered, distilled at 130°C under an applied auxiliary vacuum <5 mbar, freed of volatiles, chain length N = 13.6, MW = 1112.9 g / mol determined from 29< 2Si NMR spectrum). With stirring, 4.6 g of the prepared titanium catalyst were added. An aliquot taken from the homogeneous reaction matrix was placed in a 10 mm thick glass cuvette, and text immediately behind it (font: Arial, style: standard, ink color: black on white paper) was legible without distortion under artificial light, indicating that the reaction matrix was a The mixture was found to be turbid and the catalyst was deemed compatible with the invention. After reintroducing the sample volume into the reaction mixture, the mixture is heated to 130°C.After a 1-hour reaction time, an auxiliary vacuum was applied for a further 4 hours in the pressure range between 600 mbar and 100 mbar to remove volatile components.

[0136] The residue isolated after cooling is a clear, slightly yellowish product, whose associated 29< Si NMR spectrum confirms the complete conversion of the acetoxysiloxane used. 2. Application-related testing 2.1 Anti-graffiti effect

[0137] Sheets coated with the curable condensation compounds according to the invention (Examples 1 to 6) and cured were used to determine their anti-graffiti properties. Examples 1, 2, and 6 cured without the addition of curing catalysts. In Examples 3, 4, and 5, 5.0 wt% Dynasylan AMEO, based on the total mass of the resin, was added as a curing catalyst (see Table 3).

[0138] As a comparative example VG1, Silikophen AC1000 was applied to the sheets and cured with 1.5 wt% tetra-n-butyl titanate (TnBT) based on the total amount of resin. As a comparative example VG2, Dowsil 3074 Intermediate was applied to the sheets and cured with 5.0 wt% Dynasylan AMEO based on the total amount of resin.

[0139] The results are listed in Table 3. It shows that the comparison examples VG1 and VG2 did not exhibit any anti-graffiti effect, as the sprayed paint layer could not be removed. The coatings according to the invention with the curable condensation compounds 1–6 did exhibit an anti-graffiti effect. Some coatings according to the invention even withstood up to five cleaning cycles. Table 3: Anti-graffiti effect Example catalyst % by weight Anti-graffiti effect Cycles 1 Yes 2 2 Yes 2 3 AMEO 5,0 Yes 5 4 AMEO 5,0 Yes 3 5 AMEO 5,0 Yes 1 6 - Yes 2 VG1 TnBT 1,5 no 0 VG2 AMEO 5,0 no 0 2.3 Gliding ability

[0140] As a comparative example (VG3), Silikophen AC1000 was applied to the sheet metal and cured using 1.5 wt% tetra(n-butyl)titanate based on the total amount of resin. The results are summarized in Table 4. It is shown that the coatings according to the invention, Examples 1 and 6, have a significantly reduced sliding coefficient compared to the comparative example (VG3). The sliding properties of the coatings according to the invention are therefore better than those of the comparative example. Table 4: Sliding Values Example Glide ratio / cN 1 129 6 66 VG3 229

Claims

1. Curable condensation compounds obtainable by the reaction of - end-equilibrated acetoxy group-bearing siloxanes of formula (I) and / or formula (II): where R = an alkyl radical having 1 to 4 carbon atoms and / or phenyl radical, preferably R = methyl radical, and 1 ≤ x ≤ 500, preferably 3 ≤ x ≤ 100, more preferably 5 ≤ x ≤ 40, or where 0 ≤ a ≤ 100 and 1 ≤ b ≤ 10, preferably with 2 ≤ a ≤ 30 and 1 ≤ b ≤ 6, more preferably with 3 ≤ a ≤ 10 and 2 ≤ b ≤ 5, - with at least one alkoxy-functional polysiloxane of the formula (III)         R1cSi(OR2)dO(4-c-d) / 2     Formula (III) in which c is not less than 0 to not more than 2 and d is not less than 0 to not more than 4, and the sum total of c + d is less than 4, R1 is the same or different and is independently linear or branched, saturated or else mono- or polyunsaturated or aromatic hydrocarbon radicals, and R2 is an alkyl group consisting of 1 to 8 carbon atoms, preferably a methyl or ethyl group, - in the presence of a catalyst.

2. Condensation compounds according to Claim 1, characterized in that the reaction includes at least one crosslinker of formula (IV)         R3eSi(OR4)f     Formula (IV) in which e is not less than 0 to not more than 2, f is not less than 2 to not more than 4, and the sum total of e + f is 4, R3 = a saturated or unsaturated alkyl group consisting of 1 to 8 carbon atoms or an aromatic moiety having 6 to 20 carbon atoms and R4 = an alkyl or acyl group consisting of 1 to 8 carbon atoms.

3. Condensation compounds according to either of the preceding claims, characterized in that end-equilibrated acetoxy group-bearing siloxanes of formula (I) or formula (II) have been neutralized.

4. Condensation compounds according to any of the preceding claims, characterized in that α,ω-acetoxy group-bearing linear polydimethylsiloxanes are used for the reaction.

5. Condensation compounds according to any of the preceding claims, characterized in that the alkoxy-functional polysiloxane has R1 radicals = methyl and phenyl radicals.

6. Condensation compounds according to any of the preceding claims, characterized in that the weight-average molecular weight of the alkoxy-functional polysiloxanes is 200 to 20 000 g / mol, preferably 200 to 10 000 g / mol, more preferably 300 to 3000 g / mol and even further preferably 400 to 2000 g / mol, determined to DIN 55672-1.

7. Condensation compounds according to any of the preceding claims, characterized in that the alkoxy functionality of the alkoxy-functional polysiloxanes is from 50% to 3% by weight, preferably 40% to 5% by weight and more preferably 30% to 7% by weight, based on the total mass of the compound.

8. Condensation compounds according to any of the preceding claims, characterized in that the catalyst is selected from tin diacetate, tin dioctoate, dibutyltin diacetylacetonate, dibutyltin dilaurate, tin tetraacetate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dioleate, dimethoxydibutyltin, dimethyltin, dibutyltinbenzyl maleate, bis(triethoxysiloxy)dibutyltin, diphenyltin diacetate, dioctyltin dilaurate, dioctyltin dineodecanoate, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, tetrakis(2-ethylhexoxy) titanium, diisopropoxybis(ethylacetoacetato)titanium, dipropoxybis(acetylacetonato)titanium, diisopropoxybis(acetylacetonato)titanium, dibutoxybis(acetylacetonato)titanium, triisopropoxyallyltitanium acetate, isopropoxyoctylene glycol-titanium oxide or bis(acetylacetonato)titanium oxide, lead diacetate, lead di-2-ethylhexanoate, lead dineodecanoate, lead tetraacetate, lead tetrapropionate, zinc acetylacetonate, zinc 2-ethylcaproate, zinc diacetate, bis(2-ethylhexanoyl) zinc, zinc dineodecanoate, zinc diundecenoate, zinc dimethacrylate, tetrakis(2-ethylhexanoyl) zirconium dichloride, tetrakis(methacryloyl) zirconium dichloride, cobalt diacetate, bismuth carboxylates, bismuth triflate.

9. Condensation compounds according to any of the preceding claims, characterized in that the crosslinker is selected from methyltriacetoxysilane, ethyltriacetoxysilane, dimethyldiacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethoxyphenylmethylsilane and diethoxyphenylmethylsilane.

10. Process for preparing the condensation compounds according to any of Claims 1-9, characterized in that end-equilibrated acetoxy group-bearing siloxanes of formula (I) and / or formula (II) are reacted with at least one alkoxy-functional polysiloxane of the formula (III) in the presence of a catalyst.

11. Process according to Claim 10, characterized in that the weight ratio of acetoxy group-bearing siloxanes of formula (I) and / or formula (II) to alkoxy-functional polysiloxanes of formula (III) is 1:99 to 99:1, preferably 3:97 to 50:50 and more preferably 5:95 to 30:70, based on the silicone matrix.

12. Process according to any of Claims 9-11, characterized in that the catalyst is formed in situ or prior to the reaction, preferably from a Lewis acid such as a titanium alkoxide and an anhydride such as acetic anhydride.

13. Process according to any of Claims 9-12, characterized in that the end-equilibrated acetoxy group-bearing siloxanes of formula (I) or formula (II) have been neutralized and optionally distilled.

14. Process according to any of Claims 9-13, characterized in that the acetoxy group-bearing siloxanes have D units.

15. Process according to any of Claims 9-14, characterized in that α,ω-acetoxy group-bearing linear polydimethylsiloxanes are used.

16. Process according to any of Claims 9-15, characterized in that alkoxy-functional polysiloxanes having R1 radicals = methyl and phenyl radicals are used.

17. Process according to any of Claims 9-16, characterized in that the alkoxy functionality of the alkoxy-functional polysiloxanes is from 50% to 3% by weight, preferably 40% to 5% by weight and more preferably 30% to 7% by weight, based on the total mass of the compound.

18. Process according to any of Claims 9-17, characterized in that the catalyst is selected from tin diacetate, tin dioctoate, dibutyltin diacetylacetonate, dibutyltin dilaurate, tin tetraacetate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dioleate, dimethoxydibutyltin, dimethyltin, dibutyltinbenzyl maleate, bis(triethoxysiloxy)dibutyltin, diphenyltin diacetate, dioctyltin dilaurate, dioctyltin dineodecanoate, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, tetrakis(2-ethylhexoxy) titanium, diisopropoxybis(ethylacetoacetato)titanium, dipropoxybis(acetylacetonato)titanium, diisopropoxybis(acetylacetonato)titanium, dibutoxybis(acetylacetonato)titanium, triisopropoxyallyltitanium acetate, isopropoxyoctylene glycol-titanium oxide or bis(acetylacetonato)titanium oxide, lead diacetate, lead di-2-ethylhexanoate, lead dineodecanoate, lead tetraacetate, lead tetrapropionate, zinc acetylacetonate, zinc 2-ethylcaproate, zinc diacetate, bis(2-ethylhexanoyl) zinc, zinc dineodecanoate, zinc diundecenoate, zinc dimethacrylate, tetrakis(2-ethylhexanoyl)zirconium dichloride, tetrakis(methacryloyl) zirconium dichloride, cobalt diacetate, bismuth carboxylates, bismuth triflate.

19. Process according to any of Claims 9-18, characterized in that at least one crosslinker of formula (IV) is used.

20. Process according to any of Claims 9-19, characterized in that the crosslinker is selected from methyltriacetoxysilane, ethyltriacetoxysilane, dimethyldiacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane and dimethoxyphenylmethylsilane.

21. Process according to any of Claims 9-20, characterized in that the acetic ester formed from the R2 radical and the acetoxy group is removed during the reaction.

22. Process according to Claim 21, characterized in that the acetic ester formed is removed from the reaction by distillation and / or optionally with application of an auxiliary vacuum.

23. Process according to any of Claims 9-22, characterized in that the condensation reaction is complete with respect to acetoxysiloxane / silane used.

24. Use of the curable condensation compounds according to any of Claims 1-9 for production of coatings having anti-adhesive properties, anti-graffiti properties and / or anti-fouling properties.

25. Coated product having a coating comprising a condensation compound according to any of Claims 1-9.