WO2021213916A1

WO2021213916A1 - Fluorinated silazane polymers for functional coatings

Info

Publication number: WO2021213916A1
Application number: PCT/EP2021/059902
Authority: WO
Inventors: Ralf Grottenmueller; Fanny SCHOOREN; Fabian Koch; Yvonne FALZ; Martin Roeder; Theresa LORENZ
Original assignee: Merck Patent Gmbh
Priority date: 2020-04-20
Filing date: 2021-04-16
Publication date: 2021-10-28

Abstract

The present invention relates to new fluorinated silazane polymers, methods for their preparation, methods for preparing a coated article using said fluorinated silazane polymers and a coated article obtained from said methods. The fluorinated silazane polymers are particularly suitable for the preparation of functional coatings on various base material substrates imparting enhanced physical and chemical surface properties.

Description

Fluorinated Silazane Polymers For Functional Coatings

Technical Field The present invention relates to new fluorinated silazane polymers, methods for their preparation, methods for preparing a coated article using said fluorinated silazane polymers and a coated article obtained from said methods. The fluorinated silazane polymers are particularly suitable for the preparation of functional coatings on various base material substrates being excellent in adhesion and imparting enhanced physical and chemical surface properties such as, for example, improved water and oil repellency (hydro- and oleophobicity), improved easy-to-clean effect, improved anti graffiti effect, improved long-term stability as well as improved corrosion and/or oxidation resistance (e.g. against solvents, acidic and alkaline media and corrosive gases).

Beyond that, further beneficial surface properties may be obtained or improved by functional coatings which are based on the fluorinated silazane polymers according to the present invention such as, e.g. anti-staining effect, anti-fingerprint effect, anti-fouling effect, smoothening effect, and/or optical effects.

Furthermore, the fluorinated silazane polymers show high adhesion to various substrate surfaces and they allow an easy application by user- friendly methods so that functional surface coatings with various film thicknesses may be obtained in an efficient and easy manner under mild conditions.

Background of the Invention

Silazanes are resins used for the preparation of functional coatings for various applications. Silazanes are oligomeric or polymeric materials characterized by a silicon-nitrogen backbone represented by the general formula -[SiR2-NR’]_n-. If all substituents R and R’ are hydrogen, the material is called perhydropolysilazane (PHPS) and, if at least one of R and R’ is an organic moiety, the material is called organopolysilazane (OPSZ). PHPS and OPSZ are used for a variety of functional coatings to impart certain properties to surfaces, such as e.g. anti-graffiti effect, scratch resistance, corrosion resistance or hydro- and oleophobicity. Hence, silazanes are widely used for functional coatings for various applications. While polysilazanes are composed of one or more different silazane repeating units, polysiloxazanes additionally contain one or more different siloxane repeating units. Polysiloxazanes combine features of polysilazane and polysiloxane chemistry and behavior. Polysilazanes and polysiloxazanes are resins that are used for the preparation of functional coatings for different types of application. Typically, both polysilazanes and polysiloxazanes are liquid polymers which become solid at molecular weights of ca. > 10,000 g/mol. In most applications, liquid polymers of moderate molecular weights, typically in the range from 2,000 to 8,000 g/mol, are used. For preparing solid coatings from such liquid polymers, a curing step is required which is carried out after applying the material on a substrate, either as a pure material or as a formulation.

Polysilazanes or polysiloxazanes can be crosslinked by hydrolysis, wherein moisture from the air reacts according to the mechanisms as shown by Equations (I) and (II) below:

Equation (I): Hydrolysis of Si-N bond

RsSi-NH-SiRs + H₂0 R₃Si-0-SiR₃ + NH₃

Equation (II): Hydrolysis of Si-H bond RsSi-H + H-SiRs + H₂0 R₃Si-0-SiR₃ + 2 H₂

During hydrolysis the polymers crosslink and the increasing molecular weight leads to a solidification of the material. Hence, the crosslinking reactions lead to a curing of the polysilazane or polysiloxazane material.

For this reason, in the present application the terms “curing” and “crosslinking” and the corresponding verbs “cure” and “crosslink” are interchangeably used as synonyms when referred to silazane based polymers such as e.g. polysilazanes and polysiloxazanes. Usually, curing is performed by hydrolysis at ambient conditions or at elevated temperatures.

There is a strong need to find novel material systems which allow the preparation of improved functional coatings that meet the increasingly demanding requirements in industry. Anti-graffiti and easy-to-clean effects are achieved by creating surfaces with a low surface energy which cannot be wetted by conventional markers and sprays. Therefore, liquid paint or ink cannot spread on the low energy surface and cannot form a closed film, but it repels in the form of droplets which can be easily removed from the surface.

Anti-graffiti and easy-to-clean coatings are usually made of silicone or siloxane materials and high-performing anti-graffiti and easy-to-clean coatings are made of fluorinated materials, since fluorinated surfaces have very low surface energies of < 20 mJ/m² Silazanes are also known as base resins for anti-graffiti and easy-to-clean coatings (see e.g. WO 2006/089649 A1 ) due to their glass-like hardness after curing in combination with a low surface energy being in the same range as silicones. Very well performing anti-graffiti and easy-to-clean coatings can be obtained by the combination of silazanes and fluorinated resins or additives. Several such combinations have been proposed in literature. For example, fluorine-modified polysilazanes via Si-H bond activation and their application as protective hydrophobic coatings are described in J. Mater. Chem. A, 2017, 5, 25509. Here, fluorine-modified polysilazanes having silicon-(fluorinated)alkoxide side chains Si-0-CH₂-CF3 are described. Disadvantage of this chemistry is the instability of Si-O-R groups towards hydrolysis.

CN 107022269 A describes a self-cleaning, super hard and hydrophobic formulation based on a polyacrylate, S1O₂ nanoparticles and a fluorinated OPSZ which may have Si-CF₃, Si-CH₂-CF₃, Si-CH₂-CH₂-CF₃ or Si-CH₂- CH₂-COO-CH₂-CF3 groups. Disadvantages are the short fluorinated sides chain and the random distribution of the fluorinated groups being “diluted” by non-fluorinated silazane monomer units, which makes it impossible to achieve a fully fluorinated surface.

US 9,994,732 B1 relates to mixtures of OPSZ and fluorinated acrylic polymers. Due to the incompatibility of both polymers, a demixing and formation of turbid films may occur during processing and curing, especially in case fluoroacrylates with high molecular weight are used. If fluoroacrylates with low molecular weight are used, good miscibility is given, but the repellent effects of the obtained coatings are poor. To avoid macroscopic phase separation, the maximum amount of fluoro acrylate is limited to a small percentage only. US 10,584,264 B1 relates to hydrophobic and oleophobic coating compositions including at least a polysilazane polymer, a fluoroacrylate copolymer, and a thermosetting fluorinated polymer. The coating compositions can be applied to a substrate in a single-step process as a thick and durable polymeric layer. Methods for making the coating composition and related articles are also provided. US 2012/0264962 A1 describes silazane compounds having two fluoroalkyl groups which are obtained from specific chlorosilane monomers having double chain fluorinated silicon sidechains. Disadvantages are the multi- step synthesis of the monomer and the fact that the fluorinated groups are randomly distributed within the polymer so that the fluorinated parts are

“diluted” by fluorine-free silazane repeating units, which makes it impossible to achieve a fully fluorinated surface.

WO 2011/002668 A1 relates to methods of treating substrates to impart water, oil, stain, and/or dirt repellency to a surface thereof. In particular, a surface treatment process is described, which comprises (a) providing at least one substrate having at least one major surface; (b) combining (1) at least one curable oligomeric or polymeric polysilazane comprising at least one chemically reactive site, and (2) at least one fluorochemical compound comprising (i) at least one organofluorine or heteroorganofluorine moiety that comprises at least about six perfluorinated atoms, and (ii) at least one functional group that is capable of reacting with the polysilazane through the at least one of the chemically reactive sties; (c) allowing or inducing the polysilazane and the fluorochemical compound to react to form at least one curable organofluorine-modified polysilazane; (d) applying the curable organofluorine-modified polysilazane or its precursors to at least a portion of at least one major surface of the substrate; and (e) curing the curable organofluorine-modified polysilazane to form a surface treatment. CN 108329480 A relates to a modified polysilazane prepolymer, a modified polysilazane coating and a usage method of the modified polysilazane coating. The modified polysilazane prepolymer is prepared by mixing a perfluoropolyether, a polysilazane and a catalyst and it is said to be environmentally friendly, to show good adhesion with surfaces of most base materials, and to form coatings with high hardness as well as good hydrophobic and oleophobic properties, solvent resistance, high- temperature resistance and salt-spray resistance. US 2016/0229875 A1 relates to methods of treating substrates to impart water, oil, stain and/or dirt repellency to a surface thereof, and to compositions for use in the methods and to substrates treated thereby. Here, a fluoroalkylsilane is used represented by the formula: R_f-0-CHFCF₂- 0-(CH₂)_q-Si(X)_xR3-_x, wherein R_f is a perfluoroalkyl group, optionally substituted by one or more of -0-, -S- or NR_f ¹ -heteroatoms, wherein R_f ¹ is a perfluoroalkyl; X is a hydrolysable group; R is an alkyl group or an aryl group; q is at least 3; and x is 1 to 3.

The above-mentioned compounds, materials and methods suffer from the following drawbacks:

• The preparation of mixtures containing silazanes and high molecular weight fluoropolymers is limited due to the components’ incompatibility. Typically, such mixtures will separate and de-mix, at latest during curing. Hence, the materials described in the prior art do not give permanent surface modifying effects. · Compounds with perfluorinated side chains based on telomer chemistry show bio-accumulation and toxicity towards various organisms and are prohibited. This is particularly the case for telomers derived from > CsFi7 chains. On the other hand, telomers derived from C4F9 chains do not show satisfactory surface repellent effects such as anti-graffiti, easy-to-clean and oleophobic effects.

• Beyond that, the known compounds and materials show deficits as regards the combination and balance of adhesion to the substrate on the one hand and easy-to-clean effects such as e.g. dirt repellency on the other hand. Furthermore, there is a need for improvement of the known compounds and materials as regards hardness and durability such as e.g. abrasion resistance of coatings obtained therefrom.

Given the above drawbacks, there is a strong need to find new fluorinated polysilazane materials which overcome the defects known from the prior art.

Object of the Invention It is an object of the present invention to overcome the disadvantages in the prior art and to provide new eco-friendly fluorinated silazane polymers, methods for their preparation, methods for preparing a coated article using said fluorinated silazane polymers and a coated article obtained from said methods.

It is a further object of the present invention to provide new fluorinated silazane polymers and methods for their production, wherein the fluorinated silazane polymers are particularly suitable for the preparation of stable functional coatings on various base material substrates imparting enhanced physical and chemical surface properties such as improved water and oil repellency (hydro- and oleophobicity), improved easy-to-clean effect, improved anti-graffiti effect, improved long-term stability as well as improved corrosion and/or oxidation resistance (e.g. against solvents, acidic and alkaline media and corrosive gases).

Moreover, it is an object of the present invention to prevent phase separation and de-mixing when preparing coating compositions for the preparation of surface coated articles containing fluorinated polysilazane material or when curing such coating compositions.

Beyond that, it is an object of the present invention to obtain or to improve further beneficial surface properties of functional coatings which are based or obtained from the fluorinated silazane polymers such as, e.g. anti staining effect, anti-fingerprint effect, anti-fouling effect, smoothening effect, and/or optical effects. Moreover, it is an object of the present invention to provide new coating compositions which, in addition to the above-mentioned advantages, show high adhesion to various substrate surfaces and allow an easy application by user-friendly methods so that functional surface coatings with high film thicknesses may be obtained in an efficient and easy manner under mild conditions.

It is a further object of the present invention to provide a method for preparing coated articles and coated articles which are obtained by said method and show the above-mentioned advantages.

Summary of the Invention

The present inventors have surprisingly found that the above objects are solved either individually or in any combination by the following embodiments:

Embodiment A

Method for preparing a fluorinated silazane polymer by reacting a mixture comprising a first organosilane, a fluorinated alkyl ether compound, and an amine, wherein the fluorinated alkyl ether compound comprises one or more -CHF-CF2-Y- moiety and a -SiX_aR^A _b group, wherein Y is 0 or S; X is a halogen atom; R^A is hydrogen, an organic group, or a hetero-organic group; a = 1 , 2 or 3; and b = 3 - a.

Fluorinated silazane polymer, obtainable by the aforementioned method for preparing a fluorinated silazane polymer. Embodiment B

Method for preparing a fluorinated silazane polymer by reacting a mixture containing a polymer comprising a silazane repeating unit M¹ with a fluorinated alkyl ether compound, wherein the fluorinated alkyl ether compound comprises one or more -CHF-CF2-Y- moiety and a -CR^B=CFl2 group, wherein Y is 0 or S; and R^B is FI or an alkyl group. Fluorinated silazane polymer, obtainable by the aforementioned method for preparing a fluorinated silazane polymer.

Embodiment C Fluorinated silazane polymer comprising one or more -CFIF-CF2-Y- moiety, wherein Y is = 0 or S.

Embodiment D Method for preparing a coated article comprising the following steps:

(a1 ) applying a coating composition to a surface of an article, wherein the coating composition contains a polymer comprising a silazane repeating unit M³; and a fluorinated alkyl ether compound comprising one or more -CFIF-CF2-Y- moiety and a -Si(OR^D)3 group, wherein Y is 0 or S; and R^D is FI or an alkyl group; and

(b1 ) curing said coating composition applied on the surface of the article to obtain a coated article.

Embodiment E

Method for preparing a coated article comprising the following steps: (a2) applying a coating composition to a surface of an article, wherein the coating composition contains a fluorinated silazane polymer according to one of Embodiments A, B and C; and

(b2) curing said coating composition applied on the surface of the article to obtain a coated article.

Embodiment F

Finally, there is provided a coated article, obtainable by the method for preparing a coated article according to one of Embodiments D and E.

Preferred embodiments of the invention are described in the dependent claims. Detailed Description

Definitions

The term “polymer” includes, but is not limited to, homopolymers, copolymers, for example, block, random, and alternating copolymers, terpolymers, quaterpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” shall include all possible configurational isomers of the material. These configurations include, but are not limited to isotactic, syndiotactic, and atactic symmetries. A polymer is a molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units (i.e. repeating units) derived, actually or conceptually, from molecules of low relative mass (i.e. monomers). Typically, the number of repeating units is higher than 10, preferably higher than 20, in polymers. If the number of repeating units is less than 10, the polymers may also be referred to as oligomers. The term “monomer” as used herein, refers to a molecule which can undergo polymerization thereby contributing constitutional units (repeating units) to the essential structure of a polymer.

The term “homopolymer” as used herein, stands for a polymer derived from one species of (real, implicit or hypothetical) monomer.

The term “copolymer” as used herein, generally means any polymer derived from more than one species of monomer, wherein the polymer contains more than one species of corresponding repeating unit. In one embodiment the copolymer is the reaction product of two or more species of monomer and thus comprises two or more species of corresponding repeating unit. It is preferred that the copolymer comprises two, three, four, five or six species of repeating unit. Copolymers that are obtained by copolymerization of three monomer species can also be referred to as terpolymers. Copolymers that are obtained by copolymerization of four monomer species can also be referred to as quaterpolymers. Copolymers may be present as block, random, and/or alternating copolymers.

The term “block copolymer” as used herein, stands for a copolymer, wherein adjacent blocks are constitutionally different, i.e. adjacent blocks comprise repeating units derived from different species of monomer or from the same species of monomer but with a different composition or sequence distribution of repeating units.

Further, the term “random copolymer” as used herein, refers to a polymer formed of macromolecules in which the probability of finding a given repeating unit at any given site in the chain is independent of the nature of the adjacent repeating units. Usually, in a random copolymer, the sequence distribution of repeating units follows Bernoullian statistics. The term “alternating copolymer” as used herein, stands for a copolymer consisting of macromolecules comprising two species of repeating units in alternating sequence. The term “polysilazane” as used herein, refers to a polymer in which silicon and nitrogen atoms alternate to form the basic backbone. Since each silicon atom is bound to at least one nitrogen atom and each nitrogen atom to at least one silicon atom, both chains and rings of the general formula -[SiR¹R²-NR³-]_m (silazane repeating unit) occur, wherein R¹ to R³ may be hydrogen atoms, organic substituents or hetero-organic substituents; and m is an integer. If all substituents R¹ to R³ are hydrogen atoms, the polymer is designated as perhydropolysilazane, polyperhydrosilazane or inorganic polysilazane (-[SiH2-NH-]_m). If at least one substituent R¹ to R³ is an organic or hetero-organic substituent, the polymer is designated as organopolysilazane.

The term “polysiloxazane” as used herein, refers to a polysilazane which additionally contains sections in which silicon and oxygen atoms alternate. Such sections may be represented, for example, by -[0-SiR⁷R⁸-]_n, wherein R⁷ and R⁸ may be hydrogen atoms, organic substituents, or hetero-organic substituents; and n is an integer. If all substituents of the polymer are hydrogen atoms, the polymer is designated as perhydropolysiloxazane. If at least one substituent of the polymer is an organic or hetero-organic substituent, the polymer is designated as organopolysiloxazane.

The term “functional coating” as used herein refers to coatings which impart one or more specific properties to a surface. Generally, coatings are needed to protect surfaces or impart specific effects to surfaces. There are various effects which may be imparted by functional coatings. For example, mechanical resistance, surface hardness, scratch resistance, abrasion resistance, anti-microbial effect, anti-fouling effect, wetting effect (towards water), hydro-and oleophobicity, smoothening effect, durability effect, antistatic effect, anti-staining effect, anti-fingerprint effect, easy-to-clean effect, anti-graffiti effect, chemical resistance, corrosion resistance, anti oxidation effect, physical barrier effect, sealing effect, heat resistance, fire resistance, low shrinkage, UV-barrier effect, light fastness, and/or optical effects.

The term “cure” means conversion to a crosslinked polymer network (for example, through irradiation or catalysis). The term “fluoro-“ (for example, in reference to a group or moiety, such as in the case of “fluoroalkylene” or “fluoroalkyl”) or “fluorinated” means that one or more fluorine atoms are present.

The term “perfluoro-" (for example, in the reference to a group or moiety, such as in the case of “perfluoroalkylene” or “perfluoroalkyl”) or

“perfluorinated” means complete fluorination so that, except as otherwise indicated, no carbon-bonded hydrogen atom is left which may be replaced by fluorine. The term “aryl” as used herein, means a mono-, bi- or tricyclic aromatic or heteroaromatic group which is optionally substituted. Heteroaromatic groups contain one or more heteroatoms (e.g. N, 0, S and/or P) in the aromatic moiety. Preferred embodiments

Embodiment A

The present invention relates to a method for preparing a fluorinated silazane polymer by reacting a mixture comprising a first organosilane, a fluorinated alkyl ether compound, and an amine, wherein the fluorinated alkyl ether compound comprises one or more -CHF-CF2-Y- moiety and a -SiX_aR^A _b group, wherein Y is 0 or S; X is a halogen atom; R^A is selected from hydrogen, an organic group, or a hetero-organic group; a = 1 , 2 or 3, preferably a = 3; and b = 3 - a, preferably b = 0. In a preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment A, the fluorinated alkyl ether compound used in the above method for preparing a fluorinated silazane polymer is represented by the following Formula (A): (Rf-CHF-CF₂-Y)mL-SiX_aR^Ab Formula (A) wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms, preferably 0 or S; Y is 0 or S; L is a polyvalent organic moiety, X is selected from F, Cl, Br and I; R^A is selected from hydrogen, an organic group, or a hetero-organic group; a = 1 , 2 or 3, preferably a = 3; and b = 3 - a, preferably b = 0; and m is an integer >1.

Preferably, Rf is a perfluorinated C1-C20 alkyl group which optionally contains 0 or S. More preferably, Rf is a perfluorinated C1-C15 alkyl group which optionally contains O or S. Most preferably, Rf is selected from CF3- (CF2)O-3-, CF₃-(CF₂)0-3-O-, CF3-(CF₂)₀-3-O-(CF₂)I-3-, CF3-(CF₂)₀-3-O-(CF₂)I-3- 0-, CF3-(CF₂)O-3-0-(CF₂)I-3-0-CF₂-, CF3-(CF₂)O-3-0-(CF₂-0)I-8-, and CF3- (CF₂)O-3-0-(CF₂-0)I-8-CF₂-. Preferably, L is a polyvalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. More preferably, L is a divalent, trivalent or tetravalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. L may be linear or branched. L may be saturated or unsaturated. Preferred hydrocarbon moieties are selected from C1-C20 alkylene groups, more preferably from C1-C10 alkylene groups. Preferred heteroatoms are O or S. Preferred functional groups are -OR, -0C(=0)R, -C(=0)R, -C(=0)0R, -CN and -Cl, wherein R = H or C1- C5 alkyl, more preferably H, Chh or C2H5.

Even more preferably, L is a divalent, trivalent or tetravalent C1-C16 alkylene group which optionally contains 0 or S. Particularly preferably, L is a divalent or trivalent C2-C14 alkylene group containing 0 or S.

Most preferably, L is a divalent alkylene group represented by -(CH₂)p-0-(CH₂)q-, -(CH₂)p-S-(CH₂)q- -(CH₂)_p-0-, -(CH₂)_P-S-, -(CH₂)_p-0- (CH₂)_q-0-, -(CH₂)p-S-(CH₂)_q-0-, -(CH₂)p-0-(CH₂)_q-S-, -(CH₂)_p-S-(CH₂)_q-S-, - (CH₂)p-0-(CH₂)q-0-(CH₂)r-0-, -(CH₂)p-S-(CH₂)_q-0-(CH₂)_r-0-, -(CH₂)_p-0-

(CH₂)q-S-(CH₂)rO-, -(CH₂)p-0-(CH₂)q-0-(CH₂)rS-, -(CH₂)p-S-(CH₂)_q-S- (CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-0-(CH₂)q-S-(CH₂)r-S- or - (CH₂)p-S-(CH₂)q-S-(CH₂)_r-S-, or a trivalent alkylene group represented by - (CH₂)p-(CH-)-0-(CH₂)_q-, -(CH₂)p-(CH-)-S-(CH₂)_q-, -(CH₂)_p-(CH-)-0-, (CH₂)_P- (CH-)-S-, -(CH₂)p-(CH-)-0-(CH₂)_q-0-, -(CH₂)_p-(CH-)-S-(CH₂)_q-0-, -(CH₂)_P-

(CH-)-0-(CH₂)q-S-, -(CH₂)p-(CH-)-S-(CH₂)_q-S-, -(CH₂)_p-(CH-)-0-(CH₂)_q-0- (CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)q-0-(CH₂)r-0-, -(CH₂)_p-(CH-)-0-(CH₂)_q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-0-(CH₂)q-0-(CH₂)r-S-, -(CH₂)_p-(CH-)-S-(CH₂)_q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)q-0-(CH₂)r-S-, -(CH₂)_p-(CH-)-0-(CH₂)_q-S- (CH₂)r-S- or -(CH₂)p-(CH-)-S-(CH₂)q-S-(CH₂)r-S-, wherein p is 1 , 2, 3, 4 or 5; q is 1 , 2, 3, 4 or 5; and r is 1 , 2 or 3.

Preferably, m is an integer from 1 to 10. More preferably, m is an integer from 1 to 4. Most preferably, m is 1 or 2.

Suitable organic and hetero-organic groups for R^A include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof.

In a preferred embodiment, R^A is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30

(preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine. In a more preferred embodiment, R^A is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

Most preferably, R^A is selected from the list consisting of -H, -Chh, -CH2CH3, -CH2CH2CH3, -CH(CH₃)2, -CH=CH₂, and -C₆H₅, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

Particularly preferred fluorinated alkyl ether compounds according to Formula (A) are selected from the list consisting of:

In a preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment A, the first organosilane is represented by the following Formula (I):

X'-SiRW-X" Formula (I) wherein X' and X" are independently selected from the group consisting of Cl, Br and I; and R' and R" are independently selected from hydrogen, an organic group, or a hetero-organic group.

Suitable organic and hetero-organic groups for R' and R" include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof. In a preferred embodiment, R' and R" are the same or different from each other and independently selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

In a more preferred embodiment, R' and R" are the same or different from each other and independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

Most preferably, R' and R" are the same or different from each other and independently selected from the list consisting of -H, -Chh, -CH2CH3, -CH2CH2CH3, -CH(CH₃)2, -CH=CH2, and -ObHd, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

In a preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment A, the mixture further comprises a second organosilane which is represented by the following Formula (II): X^m-SiR^INR^lv-X^lv Formula (II) wherein X¹¹¹ and X^IV are independently selected from the group consisting of Cl, Br and I; and R^IN and R^IV are independently selected from hydrogen, an organic group, or a hetero-organic group.

Suitable organic and hetero-organic groups for R^IN and R^IV include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof.

In a preferred embodiment, R^IN and R^IV are the same or different from each other and independently selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

In a more preferred embodiment, R^IN and R^IV are the same or different from each other and independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

Most preferably, R^IN and R^IV are the same or different from each other and independently selected from the list consisting of -H, -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH₃)2, -CH=CH2, and -ObHd, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine.

It is preferred that the first organosilane is different from the second organosilane.

Particularly preferred first and second organosilanes are selected from the list consisting of: CH₃(H)SiCI₂, (CH₃)2SiCI₂, CH₃CH₂(H)SiCl2, (CH₃CH₂)2SiCl2, (H₂C=CH)(H)SiCI₂, (H₂C=CH)(CH₃)SiCl2, C₆H₅(H)SiCl2, (C₆H₅)2SiCl2, CH₃CH₂CH2(CH3)SiCl2 and CFsChhCh^Ch^SiCh.

In a further preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment A, the amine is represented by the following Formula (a):

NH₂R^a Formula (a) wherein R^a is hydrogen, an organic group, or a hetero-organic group. Suitable organic and hetero-organic groups for R^a include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, trialkoxysilyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof.

(preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine or Si(OR’)3, wherein R’ is selected from alkyl having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) carbon atoms.

In a more preferred embodiment, R^a is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F, -Si(OCH₃)3, -Si(OCH₂CH₃)3, -Si(OCH₂CH₂CH₃)3, or -Si(OCH(CH₃)2)3.

Most preferably, R^a is selected from the list consisting of -H, -CH3,

-CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)2, -CH=CH_2I and -C₆H₅, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F or -Si(OCFI₂CFl3)3. Very most preferably, R^a is -FI or -CFI3.

Particularly preferred amines are selected from the list consisting of: NH3, CH₃NH₂, CH₃CH₂NH₂, CH₃CH₂CH₂NH₂, (CH₃CH₂0)₃SiCH₂CH₂CH₂NH₂, (H₂C=CH)NH₂ and (C₆H₅)NH_2. In a preferred embodiment of Embodiment A, the molar ratio of the first organosilane to the fluorinated alkyl ether compound is in the range from 100:1 to 1:100, preferably 10:1 to 1:1. In a preferred embodiment of Embodiment A, the molar ratio of the sum of the molar amounts of the first organosilane and the fluorinated alkyl ether compound to the molar amount of the amine is in the range from 2:1 to 1:2, preferably 1.5:1 to 1:1.5.

Finally, there is provided a fluorinated silazane polymer which is obtained or obtainable by the method for preparing a fluorinated silazane polymer according to Embodiment A.

Embodiment B

The present invention further relates to a method for preparing a fluorinated silazane polymer by reacting a mixture containing a polymer comprising a silazane repeating unit M¹ with a fluorinated alkyl ether compound, wherein the fluorinated alkyl ether compound comprises one or more -CFIF-CF2-Y- moiety and a -CR^B=CFl2 group, wherein Y is 0 or S; and R^B is FI or an alkyl group. In a preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment B, the fluorinated alkyl ether compound is represented by the following Formula (B):

(Rf-CHF-CF₂-Y)mL-CR^B=CH₂ Formula (B) wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms, preferably 0 or S; Y is 0 or S; L is a polyvalent organic moiety, R^B is FI or an alkyl group; and m is an integer >1. Preferably, Rf is a perfluorinated C1-C20 alkyl group which optionally contains 0 or S. More preferably, Rf is a perfluorinated C1-C15 alkyl group which optionally contains 0 or S. Most preferably, Rf is selected from CF3- (CF2)O-3-, CF₃-(CF₂)O-3-0-, CF3-(CF2)O-3-0-(CF2)I-3-, CF3-(CF2)O-3-0-(CF2)I-3- 0-, CF3-(CF₂)O-3-0-(CF₂)I-3-0-CF2-, CF₃-(CF₂)O-3-0-(CF2-0)I-8-, and CF3- (CF₂)o-3-0-(CF2-0)l-8-CF2-.

Preferably, L is a polyvalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. More preferably, L is a divalent, trivalent or tetravalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. L may be linear or branched. L may be saturated or unsaturated. Preferred hydrocarbon moieties are selected from C1-C20 alkylene groups, more preferably from C1-C10 alkylene groups. Preferred heteroatoms are O or S. Preferred functional groups are -OR, -OC(=0)R, -C(=0)R, -C(=0)OR, -CN and -Cl, wherein R = H or C1- C5 alkyl, more preferably FI, CFI3 or C2FI5.

Even more preferably, L is a divalent, trivalent or tetravalent C1-C16 alkylene group which optionally contains O or S. Particularly preferably, L is a divalent or trivalent C2-C14 alkylene group containing O or S.

Most preferably, L is a divalent alkylene group represented by -(CH₂)p-0-(CH₂)q-, -(CH₂)_P-S-(CH₂)q-, -(CH₂)p-0-, -(CH₂)_P-S-, -(CH₂)_P-0- (CH₂)_q-0-, -(CH₂)p-S-(CH₂)q-0-, -(CH₂)p-0-(CH₂)q-S-, -(CH₂)p-S-(CH₂)q-S-, - (CH₂)p-0-(CH₂)q-0-(CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-0-, -(CH₂)P-0- (CH₂)q-S-(CH₂)r-0-, -(CH₂)p-0-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-S-(CH₂)q-S- (CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-0-(CH₂)q-S-(CH₂)r-S- or - (CH₂)p-S-(CH2)q-S-(CH₂)r-S-, or a trivalent alkylene group represented by - (CH₂)p-(CH-)-0-(CH₂)q-, -(CH₂)p-(CH-)-S-(CH₂)q-, -(CH₂)_P-(CH-)-0-, (CH₂)_P- (CH-)-S-, -(CH₂)p-(CH-)-0-(CH₂)q-0-, -(CH₂)p-(CH-)-S-(CH₂)q-0-, -(CH₂)_P- (CH-)-0-(CH₂)_q-S-, -(CH₂)p-(CH-)-S-(CH₂)q-S-, -(CH₂)p-(CH-)-0-(CH₂)q-0- (CH₂)rO-, -(CH₂)p-(CH-)-S-(CH₂)q-0-(CH₂)r-0-, -(CH₂)p-(CH-)-0-(CH₂)q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-0-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-(CH-)-S-(CH₂)q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-(CH-)-0-(CH₂)q-S- (CH₂)r-S- or -(CH₂)p-(CH-)-S-(CH2)q-S-(CH₂)r-S-, wherein p is 1 , 2, 3, 4 or 5; q is 1 , 2, 3, 4 or 5; and r is 1 , 2 or 3. Preferably, R^B is H or a C1-C5 alkyl group, more preferably H, Chh or CH2CH3.

Particularly preferred fluorinated alkyl ether compounds according to Formula (B) are selected from the list consisting of:

In a preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment B, the silazane repeating unit M¹ is represented by Formula (1 ):

-[SiR¹R²-NR³-] Formula (1 ) wherein R¹ is hydrogen, and R² and R³ are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero-organic group.

Suitable organic and hetero-organic groups for R² and R³ include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, trialkoxysilyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof. In a preferred embodiment, R² is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R³ is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30

In a more preferred embodiment, R² is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R³ is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F, -Si(OCH3)3, -Si(OCH2CH3)3, -Si(OCH₂CH₂CH₃)3, or -Si(OCH(CH₃)2)3.

Most preferably, R² is selected from the list consisting of -H, -CH₃, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)2, -CH=CH₂, and -C₆H₅, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R³ is selected from the list consisting of -H, -CH3, -CH₂CH3, -CH₂CH₂CH3, -CH(CH₃)2, -CH=CH₂, and -ObHd, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F or -Si(OCH₂CH₃)3. In a further preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment B, the polymer comprising a silazane repeating unit M¹ further comprises a repeating unit M² represented by the following Formula (2):

-[SiR⁴R⁵-NR⁶-] Formula (2) wherein R⁴, R⁵ and R⁶ are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero- organic group.

Suitable organic and hetero-organic groups for R⁴, R⁵ and R⁶ include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, trialkoxysilyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof.

In a preferred embodiment, R⁴ and R⁵ are the same or different from each other and independently selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R⁶ is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine or Si(OR”)3, wherein R” is selected from alkyl having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) carbon atoms. In a more preferred embodiment, R⁴ and R⁵ are the same or different from each other and independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R⁶ is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F, -Si(OCH₃)₃, -Si(OCH₂CH₃)₃, -Si(OCH₂CH₂CH₃)₃, or -Si(OCH(CH₃)₂)_3.

Most preferably, R⁴ and R⁵ are the same or different from each other and independently selected from the list consisting of -H, -CH₃, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)₂, -CH=CH₂, and -ObH_d, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R⁶ is selected from the list consisting of -H, -CH₃, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)₂, -CH=CH₂, and -ObH_d, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F or -Si(OCFI₂CFI₃)_3.

It is preferred that the polymer comprising a silazane repeating unit M¹ comprises a further repeating unit M², wherein M¹ and M² are silazane repeating units which are different from each other.

In one embodiment, the polymer comprising a silazane repeating unit M¹ is a polysilazane which may be a perhydropolysilazane or an organopolysilazane. Preferably, the polysilazane contains a repeating unit M¹ and optionally a further repeating unit M², wherein M¹ and M² are silazane repeating units which are different from each other. Preferably, the polymer comprising a silazane repeating unit M¹ is a copolymer such as a random copolymer or a block copolymer or a copolymer containing at least one random sequence section and at least one block sequence section. More preferably, the polymer comprising a silazane repeating unit M¹ is a random copolymer or a block copolymer.

Preferably, the polymers comprising a silazane repeating unit M¹ used in the present invention have a molecular weight M_w, as determined by GPC, of at least 1 ,000 g/mol, more preferably of at least 1 ,200 g/mol, even more preferably of at least 1 ,500 g/mol. Preferably, the molecular weight M_w of the polymers comprising a silazane repeating unit M¹ is less than 100,000 g/mol. More preferably, the molecular weight M_w of the polymers comprising a silazane repeating unit M¹ is in the range from 1,500 to 50,000 g/mol. In a preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment B, the molar ratio between the polymer comprising a silazane repeating unit M¹ and the fluorinated alkyl ether compound is in the range from 1 : 100 to 1 : 1 , preferably 1 : 10 to 1 : 1. Finally, there is provided a fluorinated silazane polymer which is obtained or obtainable by the method for preparing a fluorinated silazane polymer according to Embodiment B.

Embodiment C

The present invention further relates to a fluorinated silazane polymer comprising one or more -CHF-CF2-Y- moiety, wherein Y is = O or S. It is preferred that the fluorinated silazane polymer according to Embodiment C comprises a repeating unit M¹⁰ represented by the following Formula (C-l) or Formula (C-ll):

Formula (C-l)

Formula (C-ll) wherein R^C2 and R^C3 are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero- organic group; R^C1° represents (Rf-CFIF-CF₂-Y)_mL-, wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms, preferably O or S; Y is O or S; L is a polyvalent organic moiety; and m is an integer from 1 to 10.

Suitable organic and hetero-organic groups for R^C2 and R^C3 include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, trialkoxysilyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof. In a preferred embodiment, R^C2 is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R^C3 is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine or Si(OR’)3, wherein R’ is selected from alkyl having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) carbon atoms. In a more preferred embodiment, R^C2 is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R^C3 is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F, -Si(OCH3)3, -Si(OCH2CH3)3, -Si(OCH₂CH₂CH₃)3, or -Si(OCH(CH₃)2)3.

Most preferably, R^C2 is selected from the list consisting of -H, -CH3, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)2, -CH=CH_2I and -C₆H₅, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R^C3 is selected from the list consisting of -H, -CH3, -CH₂CH3, -CH₂CH₂CH3, -CH(CH₃)2, -CH=CH₂, and -ObHd, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F or -Si(OCH₂CH₃)3.

Preferably, Rf is a perfluorinated C1-C20 alkyl group which optionally contains 0 or S. More preferably, Rf is a perfluorinated C1-C15 alkyl group which optionally contains 0 or S. Most preferably, Rf is selected from CF3- (CF2)O-3-, CF₃-(CF₂)0-3-O-, CF3-(CF₂)₀-3-O-(CF₂)I-3-, CF3-(CF₂)₀-3-O-(CF₂)I-3- 0-, CF3-(CF₂)O-3-0-(CF₂)I-3-0-CF₂-, CF3-(CF₂)O-3-0-(CF₂-0)I-8-, and CF3- (CF₂)O-3-0-(CF₂-0)I-8-CF₂-.

Preferably, L is a polyvalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. More preferably, L is a divalent, trivalent or tetravalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. L may be linear or branched. L may be saturated or unsaturated. Preferred hydrocarbon moieties are selected from C1-C20 alkylene groups, more preferably from C1-C10 alkylene groups. Preferred heteroatoms are 0 or S. Preferred functional groups are -OR, -0C(=0)R, -C(=0)R, -C(=0)0R, -CN and -Cl, wherein R = H or C1- C5 alkyl, more preferably FI, CFI3 or C₂Fl5.

Even more preferably, L is a divalent, trivalent or tetravalent C1-C16 alkylene group which optionally contains 0 or S. Particularly preferably, L is a divalent or trivalent C2-C14 alkylene group containing 0 or S. Most preferably, L is a divalent alkylene group represented by -(CH₂)_p-0-(CH₂)q-, -(CH₂)p-S-(CH₂)_q-, -(CH₂)_p-0-, -(CH₂)_P-S-, -(CH₂)_p-0-

(CH₂)_q-0-, -(CH₂)p-S-(CH₂)_q-0-, -(CH₂)p-0-(CH₂)_q-S-, -(CH₂)_p-S-(CH₂)_q-S-, - (CH₂)p-0-(CH₂)q-0-(CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-0-, -(CH₂)p-0- (CH₂)q-S-(CH₂)r-0-, -(CH₂)p-0-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-S-(CH₂)q-S- (CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-0-(CH₂)q-S-(CH₂)r-S- or - (CFI₂)p-S-(CFI₂)q-S-(CFI₂)r-S-, or a trivalent alkylene group represented by -

(CH₂)p-(CH-)-0-(CH₂)_q-, -(CH₂)p-(CH-)-S-(CH₂)_q-, -(CH₂)_p-(CH-)-0-, (CH₂)_P- (CH-)-S-, -(CH₂)p-(CH-)-0-(CH₂)_q-0-, -(CH₂)_p-(CH-)-S-(CH₂)_q-0-, -(CH₂)_P- (CH-)-0-(CH₂)_q-S-, -(CH₂)p-(CH-)-S-(CH₂)q-S-, -(CH₂)_p-(CH-)-0-(CH₂)_q-0- (CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)q-0-(CH₂)r-0- -(CH₂)_p-(CH-)-0-(CH₂)_q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-0-(CH₂)q-0-(CH₂)r-S-, -(CH₂)_p-(CH-)-S-(CH₂)_q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)q-0-(CH₂)r-S- -(CH₂)_p-(CH-)-0-(CH₂)_q-S- (CH₂)rS- or -(CH₂)p-(CH-)-S-(CH₂)q-S-(CH₂)r-S-, wherein p is 1 , 2, 3, 4 or 5; q is 1 , 2, 3, 4 or 5; and r is 1 , 2 or 3.

In a particularly preferred embodiment of the fluorinated silazane polymer according to Embodiment C, L- is represented by Sp²-Y-Sp¹-, wherein Sp² is a polyvalent C1-C10 alkylene group, Y is 0 or S, and Sp¹ is a divalent C-i- Ce alkylene group.

Embodiment D

The present invention further relates to a method for preparing a coated article comprising the following steps: (a1 ) applying a coating composition to a surface of an article, wherein the coating composition contains a polymer comprising a silazane repeating unit M³; and a fluorinated alkyl ether compound comprising one or more -CHF-CF₂-Y- moiety and a -Si(OR^D)3 group, wherein Y is 0 or S; and R^D is FI or an alkyl group; and (b1 ) curing said coating composition applied on the surface of the article to obtain a coated article.

It is preferred that in the method for preparing a coated article according to Embodiment D the fluorinated alkyl ether compound is represented by the following Formula (D):

(Rf-CHF-CF₂-Y)_mL-Si(OR^D)₃ Formula (D) wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms, preferably 0 or S; Y is 0 or S; L is a polyvalent organic moiety, R^D is H or an alkyl group; and m is an integer >1.

Preferably, Rf is a perfluorinated C1 -C20 alkyl group which optionally contains 0 or S. More preferably, Rf is a perfluorinated C1 -C15 alkyl group which optionally contains 0 or S. Most preferably, Rf is selected from CF3- (CF2)O-3-, CF₃-(CF₂)0-3-O-, CF3-(CF2)o-3-0-(CF2)l-3-, CF3-(CF2)o-3-0-(CF2)l-3- 0-, CF3-(CF₂)O-3-0-(CF₂)I-3-0-CF2-, CF3-(CF₂)O-3-0-(CF₂-0)I-8-, and CF₃-

(CF₂)O-3-0-(CF2-0)I-8-CF₂-.

Preferably, L is a polyvalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. More preferably, L is a divalent, trivalent or tetravalent hydrocarbon moiety which optionally contains heteroatoms and/or functional groups. L may be linear or branched. L may be saturated or unsaturated. Preferred hydrocarbon moieties are selected from C1-C20 alkylene groups, more preferably from C1-C10 alkylene groups. Preferred heteroatoms are 0 or S. Preferred functional groups are -OR, -0C(=0)R, -C(=0)R, -C(=0)0R, -CN and -Cl, wherein R = H or C1- C5 alkyl, more preferably FI, CFI3 or C2FI5.

Most preferably, L is a divalent alkylene group represented by -(CH₂)p-0-(CH₂)q-, -(CH₂)_P-S-(CH₂)q-, -(CH₂)p-0-, -(CH₂)_P-S-, -(CH₂)_P-0- (CH₂)_q-0-, -(CH₂)p-S-(CH₂)q-0-, -(CH₂)p-0-(CH₂)q-S-, -(CH₂)p-S-(CH₂)q-S-, - (CH₂)p-0-(CH₂)q-0-(CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-0-, -(CH₂)P-0- (CH₂)q-S-(CH₂)r-0-, -(CH₂)p-0-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-S-(CH₂)q-S-

(CH₂)r-0-, -(CH₂)p-S-(CH₂)q-0-(CH₂)r-S-, -(CH₂)p-0-(CH₂)q-S-(CH₂)r-S- or - (CH₂)p-S-(CH2)q-S-(CH₂)r-S-, or a trivalent alkylene group represented by - (CH₂)p-(CH-)-0-(CH₂)q-, -(CH₂)p-(CH-)-S-(CH₂)q- -(CH₂)_p-(CH-)-0-, (CH₂)_P- (CH-)-S-, -(CH₂)_p-(CH-)-0-(CH₂)q-0-, -(CH₂)_p-(CH-)-S-(CH₂)_q-0-, -(CH₂)_P- (CH-)-0-(CH₂)_q-S-, -(CH₂)p-(CH-)-S-(CH₂)_q-S-, -(CH₂)_p-(CH-)-0-(CH₂)_q-0- (CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)_q-0-(CH₂)r-0- -(CH₂)_p-(CH-)-0-(CH₂)_q-S- (CH₂)r-0-, -(CH₂)p-(CH-)-0-(CH₂)_q-0-(CH₂)r-S- -(CH₂)_p-(CH-)-S-(CH₂)_q-S-

(CH₂)r-0-, -(CH₂)p-(CH-)-S-(CH₂)_q-0-(CH₂)r-S- -(CH₂)_p-(CH-)-0-(CH₂)_q-S- (CH₂)rS- or -(CH₂)p-(CH-)-S-(CH₂)_q-S-(CH₂)r-S-, wherein p is 1, 2, 3, 4 or 5; q is 1 , 2, 3, 4 or 5; and r is 1 , 2 or 3. Preferably, R^D is H or a C1-C5 alkyl group, more preferably H, CFh or CH₂CH_3.

Particularly preferred fluorinated alkyl ether compounds according to Formula (D) are selected from the list consisting of:

In a preferred embodiment of the method for preparing a coated article according to Embodiment D, the silazane repeating unit M³ is represented by Formula (3):

-[SiR⁷R⁸-NR⁹-] Formula (3) wherein R⁷, R⁸ and R⁹ are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero- organic group.

Suitable organic and hetero-organic groups for R⁷, R⁸, and R⁹ include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, trialkoxysilyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof.

In a preferred embodiment, R⁷ and R⁸ are the same or different from each other and independently selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R⁹ is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine or Si(OR”)3, wherein R” is selected from alkyl having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) carbon atoms.

In a more preferred embodiment, R⁷ and R⁸ are the same or different from each other and independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R⁹ is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F, -Si(OCH₃)₃, -Si(OCH₂CH₃)₃, -Si(OCH₂CH₂CH₃)₃, or -Si(OCH(CH₃)₂)_3.

Most preferably, R⁷ and R⁸ are the same or different from each other and independently selected from the list consisting of -H, -CH₃, -CH₂CH₃, -CH2CH2CH3, -CH(CH₃)2, -CH=CH2, and -ObHd, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R⁹ is selected from the list consisting of -H, -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH₃)2, -CH=CH2, and -ObH_d, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F or -Si(OCH2CH3)3.

In a further preferred embodiment of the method for preparing a fluorinated silazane polymer according to Embodiment D, the polymer comprising a silazane repeating unit M³ further comprises a repeating unit M⁴ represented by the following Formula (4):

-[SiR¹⁰R¹¹-NR¹²-] Formula (4) wherein R¹⁰, R¹¹ and R¹² are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero- organic group.

Suitable organic and hetero-organic groups for R¹⁰, R¹¹, and R¹² include alkyl, alkylcarbonyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkylsilyl, alkylsilyloxy, arylsilyl, arylsilyloxy, alkylamino, arylamino, alkoxy, alkoxycarbonyl, alkylcarbonyloxy, aryloxy, aryloxycarbonyl, arylcarbonyloxy, arylalkyloxy, and the like, and combinations thereof (preferably, alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, alkoxy, aryloxy, arylalkyloxy, and combinations thereof); the groups preferably having from 1 to 30 carbon atoms (more preferably, 1 to 20 carbon atoms; even more preferably, 1 to 10 carbon atoms; most preferably, 1 to 6 carbon atoms (for example, methyl, ethyl or vinyl)). The groups can be further substituted with one or more substituent groups such as halogen (fluorine, chlorine, bromine, and iodine), alkoxy, alkoxycarbonyl, trialkoxysilyl, amino, carboxyl, hydroxyl, nitro, and the like, and combinations thereof. In a preferred embodiment, R¹⁰ and R¹¹ are the same or different from each other and independently selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R¹² is selected from hydrogen, alkyl having 1 to 30 (preferably 1 to 20, more preferably 1 to 10, most preferably 1 to 6) carbon atoms, alkenyl having 2 to 30 (preferably 2 to 20, more preferably 2 to 10, most preferably 2 to 6) carbon atoms, or aryl having 2 to 30 (preferably 3 to 20, more preferably 4 to 10, most preferably 6) carbon atoms, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine or Si(OR”)3, wherein R” is selected from alkyl having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) carbon atoms.

In a more preferred embodiment, R¹⁰ and R¹¹ are the same or different from each other and independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R¹² is selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, vinyl or phenyl, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F, -Si(OCH₃)₃, -Si(OCH₂CH₃)₃, -Si(OCH₂CH₂CH₃)₃, or -Si(OCH(CH₃)₂)_3.

Most preferably, R¹⁰ and R¹¹ are the same or different from each other and independently selected from the list consisting of -H, -CH₃, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)₂, -CH=CH₂, and -ObH_d, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by fluorine; and R¹² is selected from the list consisting of -H, -CH₃, -CH₂CH₃, -CH₂CH₂CH₃,

-CH(CH₃)₂, -CH=CH₂, and -ObH_d, wherein one or more hydrogen atoms bonded to carbon atoms may be replaced by -F or -Si(OCFI₂CFI₃)₃. It is preferred that the polymer comprising a silazane repeating unit M³ comprises a further repeating unit M⁴, wherein M³ and M⁴ are silazane repeating units which are different from each other.

In one embodiment, the polymer comprising a silazane repeating unit M³ is a polysilazane which may be a perhydropolysilazane or an organopolysilazane. Preferably, the polysilazane contains a repeating unit M³ and optionally a further repeating unit M⁴, wherein M³ and M⁴ are silazane repeating units which are different from each other.

Preferably, the polymer comprising a silazane repeating unit M³ is a copolymer such as a random copolymer or a block copolymer or a copolymer containing at least one random sequence section and at least one block sequence section. More preferably, the polymer comprising a silazane repeating unit M³ is a random copolymer or a block copolymer.

Preferably, the polymers comprising a silazane repeating unit M³ used in the present invention have a molecular weight M_w, as determined by GPC, of at least 1 ,000 g/mol, more preferably of at least 1 ,200 g/mol, even more preferably of at least 1 ,500 g/mol. Preferably, the molecular weight M_w of the polymers comprising a silazane repeating unit M³ is less than 100,000 g/mol. More preferably, the molecular weight M_w of the polymers comprising a silazane repeating unit M³ is in the range from 1,500 to 50,000 g/mol.

In a preferred embodiment of the method for preparing a coated article according to Embodiment D, the molar ratio between the polymer comprising a silazane repeating unit M³ and the fluorinated alkyl ether compound is in the range from 100: 1 to 1 : 1 , preferably 50: 1 to 2: 1. Embodiment E

The present invention further relates to a method for preparing a coated article comprising the following steps: (a2) applying a coating composition to a surface of an article, wherein the coating composition contains a fluorinated silazane polymer according to one of Embodiments A, B and C; and

(b2) curing said coating compositions applied on the surface of the article to obtain a coated article.

It is preferred that the coating composition applied in the method for preparing a coated article according to Embodiment D or E further comprises one or more solvents. Suitable solvents are fluorine-free organic solvents such as, for example, aliphatic or aromatic hydrocarbons, chlorinated hydrocarbons, esters such as ethyl acetate or butyl acetate, ketones such as acetone or methyl ethyl ketone, ethers such as tetrahydrofuran or dibutyl ether, and also mono- or polyalkylene glycol dialkyl ethers (glymes), or mixtures thereof. It is preferred that the coating composition applied in the method for preparing a coated article according to Embodiment D or E further comprises one or more additives. Suitable additives are selected from the list consisting of additives influencing evaporation behavior, additives influencing film formation, adhesion promoters, anti-corrosion additives, cross-linking agents, dispersants, fillers, functional pigments (e.g. for providing functional effects such as electric or thermal conductivity, magnetic properties, etc.), nanoparticles, optical pigments (e.g. for providing optical effects such as color, refractive index, pearlescent effect, etc.), particles reducing thermal expansion, primers, rheological modifiers (e.g. thickeners), surfactants (e.g. wetting and leveling agents or additives for improving hydro- or oleophobicity and anti-graffiti effects), and viscosity modifiers. Nanoparticles may be selected from nitrides, titanates, diamond, oxides, sulfides, sulfites, sulfates, silicates and carbides which may be optionally surface-modified with a capping agent. Preferably, nanoparticles are materials having a particle diameter of < 100 nm, more preferably < 80 nm, even more preferably < 60 nm, even more preferably < 40 nm, and most more preferably < 20 nm. The particle diameter may be determined by any standard method known to the skilled person. In step (a1 ) or (a2) of the method according to Embodiment D or E, it is preferred that the coating composition is applied by an application method suitable for applying liquid compositions to a surface of an article. Such methods include, for example, wiping with a cloth, wiping with a sponge, dip coating, spray coating, flow coating, roller coating, slot coating, spin coating, dispensing, screen printing, stencil printing or ink-jet printing. Dip coating and spray coating are particularly preferred.

In step (a1) or (a2) of the method according to Embodiment D or E, it is preferred that the coating composition is applied to the surface of various articles such as, for example, buildings, dentures, furnishings, furniture, sanitary equipment (toilets, sinks, bathtubs, etc.), signs, signboard, plastic products, glass products, ceramics products, metal products, wood products and vehicles (road vehicles, rail vehicles, watercrafts and aircrafts). It is preferred that the surface of the article is made of any one of the following base materials: metals (such as iron, steel, silver, zinc, aluminum, nickel, titanium, vanadium, chromium, cobalt, copper, zirconium, niobium, molybdenum, ruthenium, rhodium, silicon, boron, tin, lead or manganese or alloys thereof provided, if necessary, with an oxide or plating film); plastics (such as polymethyl methacrylate (PMMA), polyurethane, polyesters (PET), polyallyldiglycol carbonate (PADC), polycarbonate, polyimide, polyamide, epoxy resin, ABS resin, polyvinyl chloride, polyethylene (PE), polypropylene (PP), polythiocyanate, or polytetrafluoroethylene (PTFE)); glass (such as fused quartz, soda-lime- silica glass (window glass), sodium borosilicate glass (Pyrex®), lead oxide glass (crystal glass), aluminosilicate glass, or germanium-oxide glass); and construction materials (such as brick, cement, ceramics, clay, concrete, gypsum, marble, mineral wool, mortar, stone, or wood and mixtures thereof).

The base materials may be treated with a primer to enhance the adhesion of the functional coating. Such primers are, for instance, silanes, siloxanes, or silazanes. If plastic materials are used, it may be advantageous to perform a pretreatment by flaming, corona or plasma treatment which might improve the adhesion of the functional coating. If construction materials are used, it may be advantageous to perform a precoating with lacquers, varnishes or paints such as, for example, polyurethane lacquers, acrylic lacquers and/or dispersion paints.

Typically, the coating composition is applied in step (a1) or (a2) as a layer in a thickness of 0.1 pm to 100 pm, preferably 0.2 pm to 50 pm, most preferably 0.5 pm to 30 pm to the surface of the article.

The curing of the coating composition in step (b1 ) or (b2) of the method according to Embodiment D or E may be carried out under various conditions such as e.g. by ambient curing, thermal curing and/or irradiation curing. The curing is optionally carried out in the presence of moisture, preferably in the form of water vapor.

Ambient curing preferably takes place at temperatures in the range from 10 to 30°C, preferably from 20 to 25°C. Thermal curing preferably takes place at temperatures in the range from 100 to 200°C, preferably from 120 to 180°C. Preferably, the curing in step (b1) or (b2) is carried out in a furnace or climate chamber. Alternatively, if articles of very large size are coated (e.g. buildings, vehicles, etc.), the curing is preferably carried out under ambient conditions.

Preferably, the curing time for step (b1 ) or (b2) is from 0.01 to 24 h, more preferably from 0.10 to 16 h, still more preferably from 0.15 to 8 h, and most preferably from 0.20 to 5 h, depending on the coating composition and coating thickness.

After curing in step (b1) or (b2), the coating composition is chemically linked to form a coating on the surface of the article. The coating obtained by the methods according to Embodiment D or E is a rigid and dense functional coating which is excellent in adhesion to the surface and imparts at least one of the following effects: enhanced physical and chemical surface properties such as, for example, improved water and oil repellency (hydro- and oleophobicity), improved easy-to-clean effect, improved anti-graffiti effect, improved long-term stability as well as improved corrosion and/or oxidation resistance (e.g. against solvents, acidic and alkaline media and corrosive gases).

Embodiment F

Finally, the present invention relates to a coated article, which is obtainable or obtained by the method according to Embodiment D or E.

It is preferred that the coated article according to Embodiment F is coated with a functional coating. Preferably, the functional coating is excellent in adhesion to the surface and imparts at least one of the following effects: enhanced physical and chemical surface properties such as, for example, improved water and oil repellency (hydro- and oleophobicity), improved easy-to-clean effect, improved anti-graffiti effect, improved long-term stability as well as improved corrosion and/or oxidation resistance (e.g. against solvents, acidic and alkaline media and corrosive gases).

It is to be understood that the skilled person can freely combine the above- mentioned preferred, more preferred, particularly preferred and most preferred embodiments relating to the respective Embodiments A to E in any desired way.

The present invention is further illustrated by the examples following hereinafter which shall in no way be construed as limiting. The skilled person will acknowledge that various modifications, additions and alternations may be made to the invention without departing from the spirit and scope of the present invention. Examples

A) Synthesis of fluorinated silazane polymer resins from chlorosilane monomers and ammonia (Embodiment A) A fluorinated compound (I), (IV) or (V) is reacted with methyldichlorosilane (II), dimethyldichlorosilane (III) and ammonia to give a fluorinated silazane polymer. Fluorinated compound (I) was synthesized according to the procedure described in WO 2016/096129 A1. Monomers (IV) and (V) are available from GELEST Inc. Monomers (II) and (III) are available from Sigma Aldrich.

(I) C3F7-0-CFH-CF₂-0-CH2-CH(-0-CF2-CHF-0-C3F7)-CH2-0-(CH₂)3- SiCIs

(II) CH₃(H)SiCI₂ (III) (CH₃)₂SiCI₂

(IV) (3-Fleptafluoroisopropoxy)propyl-trichlorosilane

(V) Perfluorooctyl-1 H, 1 H,2H,2H-trichlorosilane General synthesis procedure of materials:

A 5L four-necked double-wall flask equipped with a mechanical stirrer, a nitrogen inlet, an ammonia inlet pipe reaching below the surface of the liquid of the reaction solution, a reflux condenser and an attached external thermostat was prepared. The flask was filled with 3L of water-free heptane, flushed with nitrogen and cooled down to an inside temperature of -5°C. Then, a mixture of the chlorosilanes (see Table 1) was added. After the temperature of the solution was constant at -5°C, ammonia gas was slowly added via the ammonia inlet pipe reaching below the surface of the reaction solution. Immediately, a white solid of ammonium chloride was precipitating. The speed of the ammonia addition was controlled in such a way, that the temperature does not exceed 0°C. After completion of the addition of ammonia, the reaction was stopped and the solution was warmed up to 25°C. The dispersion was then transferred to a suction filter and solid ammonium chloride was removed by filtration. The obtained clear colorless solution of fluorinated organosilazane polymer in heptane was evaporated to a volume of 300 ml. Then, 1000 ml of water free n-butyl acetate was added and the solution was again evaporated to a final volume of 300 ml. The obtained residue is a solution of fluorinated organosilazane polymer in n-butyl acetate at a polymer content of 40-60%.

Table 1: Preparation of fluorinated si azane polymers.

Preparation of formulations:

To evaluate the performance of the materials, a typical anti-graffiti/easy-to- clean formulation was prepared by mixing 35 g fluorinated silazane polymer material (based on the 100% pure material) (see Table 1 for type of material), 15 g 3-aminopropyl-triethoxy silane, 1.5 g Paraloid B48-S (available from Dow Chemicals), 0.5 g DBU (1.8-Diazabicyclo[5.4.0]undec- 7-ene, available from Sigma Aldrich) and 58.0 g n-butyl acetate (see Table 2). After stirring for 4 h at room temperature a clear solution was obtained.

In Formulation 7 the solvent was reduced to 57.8 g and 0.2 g of Tego Glide 410 (available from Evonik) was added.

Table 2: Preparation of formulations. ¹⁾ available from Merck KGaA.

B) Synthesis of fluorinated silazane polymer resins via Hydrosilylation (Embodiment B)

An alternative way of incorporating fluorinated side chains into a silazane polymer is by hydrosilylation of a C=C double bond in a fluorinated compound by an organosilazane polymer.

The following fluorinated compounds were used for hydrosilylation:

(VI) C3F7-0-CFH-CF₂-0-CH2-CH(-0-CF2-CHF-0-C3F7)-CH2-0-CH₂-

CH=CH₂

(VII) Perfluorooctyl-1 H.1 H.2H.2H-allyl-ether (CeFi3-CH₂-CH₂-0-CH₂- CH=CH₂)

Hydrosilylation was performed according to the following procedure: Durazane 1033 (available from MERCK) was dissolved in Xylene. Then, the fluorinated compound(VI) or (VII) was added. Subsequently, 0.1 g Karsted catalyst was added and the reaction solution was heated to 100°C under nitrogen atmosphere for 6 h. The completeness of the reaction was confirmed by ¹H-NMR: no signals of the allyl-double bond at d 5.0-5.5 [CH₂=CH-] and 5.7-6.0 [CH2=CH-] ppm detectable anymore. Clear solutions with an active content of 50 weight% were obtained (see Table 3).

Table 3: Preparation of fluorinated silazane polymers by hydrosilylation.

Preparation of formulations:

To evaluate the performance of the materials, a typical anti-graffiti/easy-to- clean formulation was prepared by mixing 70 g fluorinated silazane polymer material shown in Table 3 with 15 g 3-aminopropyl-triethoxy silane, 1.5 g Paraloid B48-S (available from Dow Chemicals), 0.5 g DBU (1.8- diazabicyclo[5.4.0]undec-7-ene) (available from Sigma Aldrich) and 15 g n- butyl acetate. After stirring for 4 h at room temperature a clear solution was obtained (see Table 4).

C) Preparation of fluorinated silazane polymer derived coatings by curing of silazane polymer in the presence of an fluorinated compound containing an alkoxy silane functional group (Embodiment D) An alternative way to prepare a coating derived from a fluorinated silazane polymer is the preparation of a coating composition containing a polymer comprising a silazane repeating unit and a fluorinated alkyl ether compound comprising at least one -CHF-CF2-Y- moiety and a -Si(OR^c)3 group, wherein Y is 0 or S; and R^c is FI or an alkyl group. Such coating composition is applied on the surface of an article and cured to obtain a coated article.

The following fluorinated compounds were used: (VIII) C3F7-0-CFH-CF₂-0-CH2-CH(-0-CF2-CHF-0-C3F7)-CH2-0-(CH₂)3-

Si(OCH₃)₃

(IX) [PERFLUORO(POLYPROPYLENEOXY)]METHOXYPROPYLTRIME THOXYSILANE [insoluble] CF₃-CF₂-CF₂-0-[(CF₂)3-0]n-CH₂-0- (CH₂)3-Si(OCH₃)₃ [Gelest Inc. Product Code SIP6720.72] (X) Fluorolink S10, (Et0)₃Si-(CH₂)3-NH-C0-CF₂-0-[CF₂-CF₂-0]m-[CF₂-

0]n-CF₂-C0-NH-(CH₂)₃-Si(0Et)₃ [available from SOLVAY]

(XI) Perfluorooctyl-1 H.1 H.2H.2H-triehoxysilane [CeFis-CFh-CFh- Si(OC₂Fl5)3 [Gelest Inc. Product Code SIT8175.0] The formulations were prepared according to the following general procedure:

100 g of silazane polymer (Durazane 1500 rapid cure), 10 g of the fluorinated compound containing an alkoxy silane functional group, 1.5 g Paraloid B48-S (available from Dow Chemicals) and 100 g n-butyl acetate were mixed for 2h.

Table 5: Composition of formulations.

D) Evaluation of film properties by coating and curing of the formulations on silicon wafers

The formulations were applied by spin-coating 4 inch Si-Wafer at a rotation speed between 500 and 2000 rpm to get a film thickness of 1.2-1.5 pm. Then, the coated wafers were cured at ambient conditions of 25°C and a relative humidity of 50% for 7 days.

Test methods and evaluation

The anti-graffiti and easy-to-clean tests were performed according the ASTM test D6578 as follows:

The substrate was painted with A) a green Edding 8400 cd/dvd/bd marker B) a black Edding 3000 permanent marker C) a blue wax crayon, and D) a red “Rico Design” Acrylic Spray Paint. The wetting of the surface was rated in 4 levels: level 1: complete de-wetting and immediate droplet formation; level 2: strong but not complete de-wetting and predominant droplet formation; level 3: minor de-wetted areas and almost undisturbed line of the marker or spot of the spray; level 4: no de-wetting and undisturbed line of the marker or spot of the spray. After allowing the painted coatings to rest for 24 h at ambient conditions, the cleanability of the surface was rated in 6 levels: level 1 : cleanable with a dry tissue; level 2: cleanable with a mild detergent solution (Hartmann Baktolin® sensitive wash); level 3: cleanable with a limonene-based cleaner (3M Industrial Cleaner - IC Cleaner Spray limonene based); level 4: cleanable with isopropanol; level 5: cleanable with methyl ethyl ketone; level 6: not cleanable with one of the above mentioned ways.

The sliding angle of a water drop was analyzed by the following procedure: A water drop of a volume of 0.2 ml was carefully placed on the wafer. Then, one side of the waver was lifted and the horizontal angle at which the drop stared to move was noted.

The contact angle was measured with a Kriiss Drop-Shape-Analyzer DSA- 100 using water and n-hexadecane (oil) as test liquid.

The smoothness was determined with the following equipment and method: A cotton cloth was fixed on the plain bottom side of a cylindrical weight with a diameter of 65 mm and a weight of 500 g. The weight was placed on top of the test surface in a strictly horizontal position, connected with a string to a “Force Gauge PCE-FM 200” (available from PCE Instruments). The Force Gauge was horizontally moved with a constant speed of 20 mm/s. The force in Newton was noted as an average between sec 3 to sec 6. The hardness was analyzed by a Crockmeter Test according to ASTM D 6279 using a 9 pm grain size abrasive paper and by pencil hardness according to DIN EN ISO 15184 / ASTM D 3363 using Austrian Creator pencils.

The test results are shown in Table 6.

Table 6: Test results of anti-graffiti and easy-to-clean test; 7 days after curing at ambient conditions.

* Non-fluorinated.

** Reference material containing CF₃ groups.

*** Turbid film with demixing of additive: not possible to measure.

¹⁾ Weathering test: according to DIN EN ISO 6270-2 for 1000 h.

²⁾ Contact angle water.

³⁾ Contact angle oil, n-hexadecane. ⁴⁾ Anti-graffiti test result: wettability of: green Edding / black Edding / wax crayon / acrylic spray. Evaluation level (naked eye observation): 1 to 4

⁵⁾ Easy-to-Clean test result: cleanability of: green water based marker / black solvent based marker/ wax crayon / acrylic spray. Evaluation level (naked eye): 1 to 6.

⁶⁾ Sliding angle water of a drop of 0.5 ml volume.

⁷⁾ Smoothness of the surface. A cotton cloth was fixed on the plain bottom side of a cylindrical weight with a diameter of 65 mm and a weight of 500 g. The weight was placed on top of the test surface in a strictly horizontal position, connected with a string to a “Force Gauge PCE-FM 200”

(available from PCE Instruments). The Force Gauge was horizontally moved with a constant speed of 20 mm/s. The force was noted as an average between sec 3 to sec 6.

⁸⁾ Flardness of the surface: 1 ) CM: analyzed by Crockmeter Test according to ASTM-D 6279 using a 9 pm grinding paper [rating: ++ = no visible scratches, + = very few scratches, 0 = some scratches, - = scratches clearly visible, -- = heavy scratches] and by 2) PH: pencil hardness according to DIN EN ISO 15184 /ASTM D 3363. In order to check the durability of the effects, Si wafers were subjected to a weathering test which was carried out as follows:

For testing the durability of the formulations, the coated Si-wafer were stored in a condensation water tester (equipment High Humidity Cabinet Type CON 400-FL AIR) according to the norm DIN EN ISO 6270-2 for a duration of 1000 h. After the weathering test was finished, all the mentioned tests were repeated to check the durability of the coating performance (see Table 7).

Table 7: Test results after 1000 h weathering test¹⁾.

¹⁾ Weathering test: according to DIN EN ISO 6270-2 for 1000 h.

^{9) ■}=> No change after weathering test; ¾ slight decrease after weathering test; Ό- severe decrease after weathering test.

The superior efficiency of the inventive material compared to the known CeFi3 based chemistry is shown in Table 8. The inventive formulations 1 and 8 and the C6F13 based formulations 3 and 9 were diluted with the fluorine free organopolysilazane Durazane 1500 rapid cure. The water and oil contact angle were measured at increasing dilution.

* Contact angle water / contact angle mineral oil.

** Contact angle water and contact angle mineral oil for pure Durazane 1500 rapid cure = 94 53°.

The following conclusions can be drawn from the results shown in Tables 6, 7 and 8:

As expected, the fluorinated materials in Formulations 1, 2, 3, 6, 8, 9, 10 and 13 show better anti-graffiti and easy-to-clean performance than non- fluorinated Formulations 4 and 5. Flowever, Formulations 1, 3, 8, 9, 10 and 13 containing long chain fluorinated materials outperform Formulations 2 and 6 containing short chain heptafluoroisopropoxy-group and trifluoropropyl-group, respectively.

The addition of surface active additives for anti-graffiti and easy-to-clean effects as performed in Formulation 7, improves anti-graffiti and easy-to- clean performance. Flowever, after the weathering test, the performance is partly lost. Nevertheless, inventive Formulations 1, 8 and 10 maintain their performance without significant change. The comparison of inventive Formulations 1, 8 and 10 and Formulations 3, 9 and 13 shows the advantage of the formulations according to the invention with regard to the performance in anti-graffiti and easy-to-clean properties as well as durability (resistance against weathering). The inventive Formulations 1, 8 and 10 maintain very high repellent properties even at high dilution when mixed at a weight ratio of 1:10 with a non- fluorinated polysilazane. In contrast, C6F13 containing formulations can only be diluted down to 1 :5. Thus, the formulations according to the invention have an improved efficiency even at very low concentration.

The inventive Formulations 1 , 8 and 10 show the best smoothness or slippery of the surface of all tested formulations, clearly outperforming short linear or branched fluorinated chains and the telomer C6F13 chains.

It has been shown that fluorinated silazane polymers according to the present invention perform excellently to achieve repellent and smooth surfaces with outstanding durability that work even at high dilutions as required for high performance anti-graffiti and easy-to-clean coatings.

Claims

1. Method for preparing a fluorinated silazane polymer by reacting a mixture comprising a first organosilane, a fluorinated alkyl ether compound, and an amine, wherein the fluorinated alkyl ether compound comprises one or more -CFIF-CF2-Y- moiety and a -SiX_aR^A _b group, wherein Y is 0 or S; X is a halogen atom; R^A is selected from hydrogen, an organic group, or a hetero-organic group; a = 1 , 2 or 3; and b = 3 - a.

2. Method for preparing a fluorinated silazane polymer according to claim 1 , wherein the fluorinated alkyl ether compound is represented by the following Formula (A):

(Rf-CHF-CF₂-Y)mL-SiX_aR^Ab Formula (A) wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms; Y is 0 or S; L is a polyvalent organic moiety; X is selected from F, Cl, Br and I; R^A is selected from hydrogen, an organic group, or a hetero-organic group; a = 1 , 2 or 3; b = 3 - a; and m is an integer >1.

3. Method for preparing a fluorinated silazane polymer according to claim 1 or 2, wherein the first organosilane is represented by the following Formula (I):

X'-SiR^'-X¹¹ Formula (I) wherein X' and X" are independently selected from the group consisting of Cl, Br and I; and R' and R" are independently selected from hydrogen, an organic group, or a hetero-organic group.

4. Method for preparing a fluorinated silazane polymer according to one or more of claims 1 to 3, wherein the mixture further comprises a second organosilane which is represented by the following Formula (II):

X^m-SiR^INR^lv-X^lv Formula (II) wherein X^IN and X^IV are independently selected from the group consisting of Cl, Br and I; and R^IN and R^IV are independently selected from hydrogen, an organic group, or a hetero-organic group.

5. Method for preparing a fluorinated silazane polymer according to one or more of claims 1 to 4, wherein the amine is represented by the following Formula (a):

NFhR³ Formula (a) wherein R^a is hydrogen, an organic group, or a hetero-organic group.

6. Method for preparing a fluorinated silazane polymer according to one or more of claims 1 to 5, wherein the molar ratio of the first organosilane to the fluorinated alkyl ether compound is in the range from 100:1 to 1 :100, preferably 10:1 to 1 :1.

7. Method for preparing a fluorinated silazane polymer according to one or more of claims 1 to 6, wherein the molar ratio of the sum of the molar amounts of the first organosilane and the fluorinated alkyl ether compound to the molar amount of the amine is in the range from 2:1 to 1 :2, preferably 1.5:1 to 1 :1.5.

8. Fluorinated silazane polymer, obtainable by the method according to one or more of claims 1 to 7.

9. Method for preparing a fluorinated silazane polymer by reacting a mixture containing a polymer comprising a silazane repeating unit M¹ with a fluorinated alkyl ether compound, wherein the fluorinated alkyl ether compound comprises one or more -CHF-CF2-Y- moiety and a -CR^B=CFl2 group, wherein Y is 0 or S; and R^B is FI or an alkyl group.

10. Method for preparing a fluorinated silazane polymer according to claim 9, wherein the fluorinated alkyl ether compound is represented by the following Formula (B):

(Rf-CHF-CF₂-Y)mL-CR^B=CH₂ Formula (B) wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms; Y is 0 or S; L is a polyvalent organic moiety; R^B is FI or an alkyl group; and m is an integer >1 .

11 . Method for preparing a fluorinated silazane polymer according to claim 9 or 10, wherein the silazane repeating unit M¹ is represented by Formula (1 ):

-[SiR¹R²-NR³-] Formula (1) wherein R¹ is hydrogen, and R² and R³ are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero-organic group.

12. Method for preparing a fluorinated silazane polymer according to one or more of claims 9 to 11 , wherein the molar ratio between the polymer comprising a silazane repeating unit M¹ and the fluorinated alkyl ether compound is in the range from 1 : 100 to 1 : 1 , preferably 1 :10 to 1 :1.

13. Fluorinated silazane polymer, obtainable by the method according to one or more of claims 9 to 12.

14. Fluorinated silazane polymer comprising one or more -CFIF-CF2-Y- moiety, wherein Y is = 0 or S.

15. Fluorinated silazane polymer according to claim 14, wherein the fluorinated silazane polymer comprises a repeating unit M¹⁰ represented by the following Formula (C-l) or Formula (C-ll):

Formula (C-l)

Formula (C-ll) wherein R^C1° represents (Rf-CFIF-CF2-Y)mL-, wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms, Y is 0 or S; L is a polyvalent organic moiety; R^C2 and R^C3 are the same or different from each other and independently selected from hydrogen, an organic group, or a hetero-organic group; and m is an integer from

1 to 10.

16. Fluorinated silazane polymer according to claim 15, wherein L- is represented by Sp²-Y-Sp¹-, wherein Sp² is a polyvalent C1-C10 alkylene group, Y is 0 or S, and Sp¹ is a divalent C1-C6 alkylene group.

17. Method for preparing a coated article comprising the following steps: (a1 ) applying a coating composition to a surface of an article, wherein the coating composition contains a polymer comprising a silazane repeating unit M³; and a fluorinated alkyl ether compound comprising one or more -CHF-CF2-Y- moiety and a -Si(OR^D)3 group, wherein Y is 0 or S; and R^D is FI or an alkyl group; and (b1 ) curing said coating composition applied on the surface of the article to obtain a coated article.

18. Method for preparing a coated article according to claim 17, wherein the fluorinated alkyl ether compound is represented by the following Formula (D): (Rf-CHF-CF₂-Y)mL-Si(OR^D)₃ Formula (D) wherein Rf is a perfluorinated alkyl group which optionally contains heteroatoms; Y is 0 or S; L is a polyvalent organic moiety; R^D is FI or an alkyl group; and m is an integer >1.

19. Method for preparing a coated article according to claim 17 or 18, wherein the silazane repeating unit M³ is represented by Formula (3):

20. Method for preparing a coated article according to one or more of claims 17 to 19, wherein the molar ratio between the polymer comprising a silazane repeating unit M³ and the fluorinated alkyl ether compound is in the range from 100: 1 to 1 : 1 , preferably 50: 1 to 2: 1.

21. Method for preparing a coated article comprising the following steps: (a2) applying a coating composition to a surface of an article, wherein the coating composition contains a fluorinated silazane polymer according to one or more of claims 8 and 13 to 16; and

22. Coated article, obtainable by the method according to one or more of claims 17 to 21.