ZA200400439B - Fluoroalkyl-modified organosilanes and their use in coating compositions. - Google Patents

Description

. © WO 03/014131 PCT/EP02/08496

Description

FLUOROALKYL-MODIFIED ORGANOSILANES AND THEIR USE IN

COATING COMPOSITIONS

The present invention relates to fluoroalkyl-modified organosilanes, to processes for preparing them, and to their use, particularly as additives in coating compositions for the purpose of reducing the soiling tendency of said compositions. The resultant coating compositions also have increased water resistance in relation to coatings into which surfactantlike comparison compounds have been incorporated. Furthermore, the impregnating effect is manifested even on repeated soiling with dirt dispersions.

It is known that the addition of low molecular mass compounds containing perfluoroalkyl groups to coating compositions leads to a reduction in the soiling tendency of said compositions.

Thus US-A+4,208,496 discloses dust-repellent paint compositions which include ionic emulsifiers of the formula F(CF2)nCH2CH2SCH2CHoCOOL.

These emulsifiers, however, have no functional groups in the molecule that could lead to anchoring in the paint film formed.

It is also known, however, that emulsifiers not chemically covalently bonded can be readily leached from coatings. Moreover, the water resistance of coatings is adversely affected by emulsifiers which are not chemically covalently bonded.

Also known are low molecular mass, silane-modified perfluoroalkane compounds of the formula CnF2n+1(CH2)2Si(OR)3, such as

CgF13(CH2)2Si(OEt)3. One of the uses of these compounds is to impregnate mineral substrates. The areas subsequently to be treated with these compounds, however, must be cleaned prior to application, and it may be necessary to repeat application of the additive. As a result of the high costs of the additive and for the multiple operations, this high-quality sealing against dirtying is very expensive. The substances are expensive owing to their synthesis by hydrosilylation, since noble metal catalysts have to be used.

i oo 2

JP-A-08/109580 describes the preparation of amino-containing siloxane compounds for fiber impregnation. A diamine-functionalized, oligomeric or polymeric siloxane is subjected to an addition reaction with (meth)acrylic esters. The presence of diamines, however, leads to an increase in the points of attack for oxidative degradation of the active substance molecule and to increased polarity and hydrophilicity of the compounds.

JP-A-09/279049, similarly, discloses silicon compounds composed of polymers containing silicon groups and of adducts of diaminosilanes and ethylenically unsaturated compounds containing perfluorinated or partly fluorinated alkyl radicals. As stated above, however, the skilled worker is aware that, owing to their higher polarity, diamines lead to higher water absorption and higher yellowing as compared with compounds which lack a second amine group but are otherwise constitutionally identical. Said yellowing occurs as a result of oxidative attack on the nitrogen atoms.

Moreover, the complex diamines or oligoamines are more expensive to - prepare than the simple aminosilanes. The presence of at least three free valences on the amino groups for adduct formation, moreover, results in the case of diaminosilanes in production of a complex product mixture, which cannot be worked up. The synthesis of a defined substance, therefore, is not economically possible. The same is true all the more for oligosilanes.

The preparation of hydrophilic organosilicon compounds by addition reaction of amino-containing silanes and/or (poly)siloxanes with (meth)- acrylates modified with (oligo)hydroxy radicals or sugar radicals is described in DE-A-198 54 186. Preferably amino-organopolysiloxanes are subjected to addition reaction with the (meth)acrylic esters. A disadvantage of such additives for reducing the soiling tendency, equipped with hydro- philic radicals, however, is their increased water absorption.

Furthermore, very recent investigations have shown that the addition of siloxanes to exterior coating materials tends to increase rather than lower their soiling tendency in outdoor weathering. This is attributed, inter alia, to the increased affinity of the hydrophobic dirt components (including soot) for the hydrophobic coating (O. Wagner in “Farbe und Lack”, 2001, 107, 105-134).

: It was therefore an object of the present invention to develop additives for coating compositions and polymer dispersions, for the purpose of reducing their soiling tendency, which are distinguished by moderate synthesis costs and raw materials costs and by low water absorption of the resultant 5S coating compositions. The intention was also that the compounds should combine the advantages both of polymeric and of low molecular mass additives, namely on the one hand a high migration capacity during film consolidation, in order to permit accumulation of the hydrophobic groups at the hydrophobic air/coating interface, and on the other hand that the additives should have an increased resistance toward leaching by rain in the coating, as is achieved by polymeric, fluorinated impregnating additions.

The present invention provides organosilanes of the general formula ()] oO 4

OS 0

Y X |, R where R is a fluorinated or partly fluorinated alkyl radical of the formula

CnZ2n+1(CH2)m-, with n > 1, m > 1, and Z either a hydrogen atom or a fluorine atom, with the proviso that at least one Z is a fluorine atom,

Y is a hydrogen atom or alkyl radical having 1 to 10 carbon atoms,

X is alternatively a hydrogen atom, a linear or branched alkyl! radical having 1 to 10 carbon atoms, a radical of the formula ROC(O)(CHY)(CHy)-, a phenyl radical or a benzyl radical, rR] is a linear or branched alkylene radical having 1 to 20 carbon atoms, and

RZ, rR, and Rr are linear or branched alkyl radicals having 1 to 10 carbon atoms or linear or branched alkoxy radicals having 1 to 10 carbon atoms, which are attached via the oxygen atom to the silicon atom.

Preferred organosilanes are those of the general formula (1) where

Ris a fluorinated alkyl radical of the formula CnF2n+1(CH2)m-.

Additionally preferred organosilanes are those of the general formula (1) wheren=1to30andm=1to4.

Further preferred organosilanes are those of the general formula (I) where

X is a methyl, an ethyl, a propyl, a phenyl or a benzyl radical,

Y is a hydrogen atom or a methyl radical,

R'isa-(CHos a -CH2CH(CH3)CHa- or a -CoHg- radical, and

R% R% and R* are a CH30-, a C2H50- or a CH(CH3),0- radical.

Particularly preferred organosilanes are those of the general formula (1) where

Ris a fluorinated alkyl radical of the formula CnF2n+1(CH2)m-, with n = 6 to 14 and m = 2. Alkyl radicals of this formula, with n = 6 to 14 and m = 2, constitute the best compromise between synthesis costs and raw materials costs, (unwanted) crystallization tendency of the fluoroalkane chain, and impregnating effect. Where (meth)acrylic esters having fluoroalkane residues of the stated fraction containing an ethyl spacer to the oxygen ester bond are used as a coupling component, the resultant fluoroalkyl- silanes are liquid at room temperature and hence easy to incorporate into coating compositions or latex dispersions.

Of particular preference are organosilanes of the general formula (1) where

X'is an ethyl radical,

Y is a hydrogen atom or a methyl radical,

R’ is a -CHaCH(CH3)CHa- radical, and rR? rR? and Rr? are a CH3O- radical; or

X is a methyl radical,

Y is a hydrogen atom or a methyl radical,

R'is a -(CHy)s- radical, and rR? RS and Rr are a CH3O- radical.

The organosilanes of the invention are both hydrophobic and oleophobic and contain no siloxane groups. The sole silicon functionality of the organo- silanes of the invention, the silane group, serves to anchor the hydrophobic and oleophobic fluoroalkyl group on the substrate.

The present invention further provides processes for preparing the organo- silanes of the invention.

The organosilanes of the invention are prepared preferably by an addition reaction, similar to the Michael reaction, of w-aminoalkylsilanes by the amino group onto the double bond of the (meth)acrylic esters with a fluorinated side chain. By (meth)acrylic esters are meant here both the esters of acrylic acid and the esters of methacrylic acid.

The present invention accordingly also provides a process for preparing the organosilanes of the invention which is characterized in that a (meth)acrylic ester of the general formula (11) is reacted with an o-aminoalkylsilane of the general formula (nm, 0)

R4 ai) oF re an) ~

Y X R? where R is a fluorinated or partly fluorinated alkyl radical of the formula

CnZ2n+1(CH2)m-, with n > 1, m > 1, and Z either a hydrogen atom or a fluorine atom, with the proviso that at least one Z is a fluorine atom,

Y is a hydrogen atom or alkyl radical having 1 to 10 carbon atoms,

X is alternatively a hydrogen atom, a linear or branched alkyl radical having 1 to 10 carbon atoms, a radical of the formula ROC(O)(CHY)(CH2)-, a phenyl radical or a benzyl radical, rR] is a linear or branched alkylene radical having 1 to 20 carbon atoms, and rR? RS and rR? are linear or branched alkyl radicals having 1 to 10 carbon atoms or linear or branched alkoxy radicals having 1 to 10 carbon atoms, which are attached via the oxygen atom to the silicon atom.

The reaction takes place either without solvent or with the addition of water, organic solvents or mixtures thereof. The reaction takes place preferably under atmospheric pressure (1 bar) but may also be conducted under increased or reduced pressure. It is additionally possible to use catalysts, accelerating the reaction.

Where a solvent is used for the preparation, either the reaction product is used in the reaction solvent or the solvent used is removed. If desired, the product obtained, following the removal of the solvent, can be dissolved in another solvent, or dispersed in water or a different liquid. Emulsifiers can be used for this purpose.

A further preferred subject matter of the present invention relates to the use of the organosilanes of the invention, particularly in coating compositions, for the treatment of surfaces in order to reduce their soiling tendency.

The organosilanes of the invention additionally find use as antiblocking agents, especially in coating compositions (e.g., varnishes for coating wood) and polymer dispersions.

A further subject matter of the present invention relates, accordingly, to the use of the organosilanes of the invention as antiblocking agents, particularly in coating compositions, for the treatment of surfaces.

It has in fact surprisingly been found that the organosilanes of the invention as additives in polymer dispersions significantly increase the blocking resistance, i.e., the resistance to sticking to similarly treated surfaces or other surfaces, of the coatings which result therefrom. For example, in the case of styrene-acrylate dispersions with a core-shell morphology, which normally exhibit moderate blocking resistance in the varnish film on wood substrates, even very small amounts of the organosilanes of the invention (e.9., 0.5% by weight) lead to excellent blocking resistances (blocking propensity with respect to similarly treated surfaces, determined at 50°C and room temperature).

Likewise provided by the present invention is the use of the organosilanes of the invention for the hydrophobicization and oleophobicization of surfaces.

For all end uses the coating of the surfaces takes place preferably by spraying the organosilanes of the invention as they are, in solution or in dispersion onto the surfaces to be treated, immersing the surface into the solution or dispersion of the additives, or applying said organosilanes with a brush or by roller, or adding them to a coating composition intended for application and comprising at least one polymeric binder, as they are, in solution or in dispersion, and applying the coating composition to the surface.

KY | | | 7

Also possible is the use of the additives of the invention as release agents for surfaces.

The present invention also provides, however, the coating compositions themselves.

Preference is given here to coating compositions comprising a) at least one polymeric binder, b) at least one organosilane of the invention, and also c)if desired, pigments, fillers, dispersants, thickeners, protective colloids, wetting agents, preservatives, algicides, anticorrosion pigments, UV filter substances, UV initiators and/or further auxiliaries.

The coating composition here comprises the polymeric binder (or binders) in solution, dispersion or emulsion in liquids, or as it is (the latter in the case, for example, of powder coating materials as coating composition). As polymeric binders it is possible to use any polymeric binders known to the skilled worker. Preferred polymeric binders are poly(acrylates), poly(styrene acrylates), poly(urethanes), poly(esters), polyesterpolyols, amino resins, epoxy resins, epoxyamine resins, alkyd resins, hybrid dispersions of poly- (styrene acrylates) or poly(acrylates) with poly(urethanes) and/or alkyd resins. Mixtures of these polymers can also be used.

With particular preference the organosilanes of the invention are used for reducing the early soiling tendency in pigmented exterior coatings with polymeric binders comprising UV initiators (such as benzophenone derivatives, for example). The UV initiator can either be present in the polymeric binder or added to the coating composition during its preparation.

Preferred applications of these coatings include, for example, elastic exterior coatings and traffic marking paints.

Particular preference is therefore given to coating compositions further comprising at least one UV initiator.

The dirt-repellent organosilanes migrate to the surface of the coating composition or polymer film and prevent sticking of the soft, polymeric binder to dirt particles until the UV initiators have brought about superficial hardening of the polymeric binder. Indeed, depending on insolation, a

KY | | 8 considerable time may pass before the UV initiator has hardened the surfaces of the coatings.

Additionally, after they have migrated to the surface of the coating composition or polymer film, the reactive groups of the organosilane react with the reactive groups of the polymer and possibly, where present, with the reactive groups of the pigments and/or fillers. By this means it is possible to prevent the organosilane being leached from the surface of the coating.

It has surprisingly been found, moreover, that the dirt-repellent effect of the organosilanes of the invention is intensified if they are used in coating compositions (including varnishes) which comprise polymer dispersions which include ethylenically unsaturated w-hydroxyalkyl acrylates or w-hydroxyalkyl methacrylates (such as 2-hydroxyethyl methacrylate, for example) in conjunction with epoxyalkylsilanes (e.g., B-(3,4-epoxycyclo- hexyl)ethyitriethoxysilane or 1-glycidyloxypropyltrimethoxysilane).

In another preferred embodiment the at least one polymeric binder of the coating composition of the invention includes at least one w-hydroxyalkyl (meth)acrylate as monomeric building block (comonomer) and at least one epoxyalkylsilane of the formula BSiR3, where the radical B is an organic radical having at least one oxirane functionality and the radicals R are alkyl or alkoxy groups of the formula -CnHan+1 or -OChH2n+1 respectively, in which n=1 to 10.

A particularly preferred w-hydroxyalkyl (meth)acrylate used is 2-hydroxy- ethyl methacrylate and a particularly preferred epoxyalkylsilane used is

B-(3.4-epoxycyclohexyl)ethyltriethoxysilane or y-glycidyloxypropyitrimethoxy- silane.

Where the organosilanes are used in coating compositions, they can either be added directly to the polymeric binder (in solution or dispersion) or else added during the production of the coating and/or the preparation of the paint.

Where the additives are used directly for impregnating surfaces, they are preferably applied in solution or dispersion.

The present invention is described in more detail below, with reference to examples, though without being restricted by said examples.

A) Description of the analysis methods:

The hydrophobicity, oleophobicity, and dirt-repellent effect of the impregnated surfaces were determined as follows:

Determination of water absorption: 9 g of demineralized water are added to 15 g of coating composition and the mixture is poured onto the underside of a plastic beaker with stand rim (approximately 11 cm in diameter). The coating film is dried at room temperature for 7 days, during which it is detached daily and turned once.

Then test specimens measuring 3x 3 cm are cut from the fim and detached from the substrate. The films are weighed (in duplicate) and then stored in water in a Petri dish for 24 hours. The water is then dabbed off with a cellulose cloth and the film is weighed again. The weight increase in percent over the initial weight corresponds to the first water absorption. The test specimens are then dried for 2 days and the film is subsequently weighed, water-exposed for 24 hours, dabbed off with a cellulose cloth, and weighed again. The second water absorption, in percent, is determined in the same way as for the first.

Determination of blushing (water susceptibility):

The dispersion is knife-coated to a glass plate (5 x 8 cm) using a 200 um box-type bar coater and dried at 40°C for one hour and then dried further overnight at room temperature. The sample is then placed in a Petri dish filled with deionized water and after about 1 5 minutes the blushing of the polymer film is evaluated on a relative scale from 1 to 5 (1 = very good, 5 = deficient).

Determination of dry soiling tendency:

The coating is applied to a glass plate using a 200 um box-type bar coater and stored in a climate chamber at 23°C and 50% relative humidity for 24 hours. Then, using an Erichsen Colorimeter model 526 (measuring geometry 45°/0°), the lightness L* in the CIELAB color system is measured against an external white standard (L* = 94.33). Using a dry brush, fly ash or a mixture of 99.5 parts by weight fly ash and 0.5 part by weight soot is rubbed into the sample plate, which is then vigorously brushed with the

CL oo 10 brush. The measurement of the lightness L* is repeated with the soiled plate. The difference from the original L* value is referred to subsequently as AL*. 9 Determination of wet soiling tendency:

Sample preparation is as for the dry soiling tendency, but the substrate used is a fiber cement sheet, Eterplan 300 x 150 x 4 mm. The wet thickness of the film is 300 um. After the L* value has been measured (Erichsen Colorimeter 526, see above) the dried sample is fixed with the coating pointing upward on a support above a drip tray, at an inclination of 60° with respect to the horizontal. 500 ml of an aqueous dispersion of standard dirt are then circulated over the sample using a peristaltic pump. This pump delivers approximately 500 ml/min. The dirt dispersion running off is collected in the tray and passed over the sample again. The dispersion is stirred with a magnetic stirrer during this operation. After 30 minutes the cycle is interrupted and the sample is dried at room temperature for 24 hours. The lightness L* is then determined using the Erichsen Colorimeter 526. Subsequently the sample is again subjected to soiling and drying cycles. Each time the L* value is determined after the drying cycle. The AL* value is obtained therefrom in each case by the difference from the original L* value prior to soiling. For each cycle a fresh dirt solution is used. The dirt solution is prepared as follows: 17 g of gas black FW 200, 70 g of Japanese standard dust No. 8,and 13 g of special pitch No. 5 (from Worlee) are weighed out into a 1000 ml powder bottle and 400 cm’ of glass beads are added. The mixture is mixed on a roller bed for 24 hours and the glass beads are removed by sieving. The powder is homogenized using a mortar and pestle. 1g of standard dirt powder is introduced together with 1 g of butyl glycol into a glass vessel and 998 g of water are added. The dispersion is stirred with a magnetic stirrer.

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B) Description of the examples:

Example 1

Preparation of the fluoroalkyl-modified organosilanes

The course of the reaction is monitored analytically by way of the amine number and by way of "H-NMR from the intensities of the protons of the acrylate double bond. a) Product A 50g of Silquest® A-Link 15 (N-ethyl-3-trimethoxysilyl-2-methyl- propanamine, Crompton) and 125 g of Fluowet® AC 812 (CH =

CHCOOCH2CHy(CF2CF2)F, n = 3 to 6, Clariant) are reacted in a 250 ml flask under an No atmosphere at 75°C with stirring for 6 hours. Cooling to room temperature gives 175g of the product in the form of an orange- brown mass, with solid and liquid fractions. b) Product B 50g of Silquest® A-Link 15 and 117 g of Fluowet® AC 800 (CH, =

CHCOOCH2CH(CF2CF2)4F, Clariant) are reacted in a 250 ml flask under an Nz atmosphere at 75°C with stirring for 6 hours. Cooling to room temperature gives 167 g of the product in the form of a partly crystalline, partly still fluid, orange-brown mass. ¢) Product C 50 g of Silquest® A-Link 15 and 125 g of Fluowet® AC 812 are reacted in a 500 ml flask under an No atmosphere in 150 g of anhydrous butyl acetate at 75°C with stirring for 8 hours. Cooling to room temperature gives 325 g of the product in the form of a clear, orange-colored solution. d) Product D 30g of Silquest® A 1100 (3-triethoxysilyl-1-propanamine, Crompton) and 153 g of Fluowet® MA 812 are reacted in a 250 ml flask under an Ny atmosphere at 75°C with stirring for 10 hours. Cooling to room temperature gives 183 g of the product in the form of a partly crystalline, partly still fluid, orange-brown mass.

. oC | 12 e) Product E 40g of Silquest® A 1100 and 152g of Fluowet® AC600 (CHz =

CHCOOCH2CH2(CF2CF2)3F, Clariant) are reacted in a 500 ml flask under an N2 atmosphere in 150 g of anhydrous butyl acetate at 75°C with stirring for 8 hours. Cooling to room temperature gives 342 g of the product in the form of a clear, yellow-orange-colored solution. f) Product F 50 g of Silquest™ A 1100 and 142 g of Fluowet® AC 600 are reacted in a 500 ml flask under an No atmosphere in 150 g of anhydrous butyl acetate at 75°C with stirring for 8 hours. Cooling to room temperature gives 342 g of the product in the form of a clear, yellow-orange colored solution.

Table 1 [ross [eronca [ Posuec rome 0 redone [rocua?

EET IT EI I NTN I

Bl 0 = acetate acetate acetate * molar ratio of aminosilane to fluoroacrylate

Example 2

Production of elastic masonry coatings

Added to 100 g of water in succession with stirring are 5g of a 10% strength solution of Calgon® N and 1.4 g of Coatex® P 90 and also 2 g of

Foammaster® 111FA. Then 80 g of titanium dioxide (Kronos® L 2310) and 380 g of calcium carbonate (Durcal® 2) are added in succession and the mixture is stirred with a dissolver at 5000 rpm for 15 minutes. Subsequently 382.3 g of a dispersion (solids content approximately 60%) are added at 500 rpm, and also 1 g of 20% strength aqueous ammonia, and the mixture is stirred for 5 minutes. Finally 2 g of Mergal® K9, 2 g of butyl diglycol, 10 g of propylene glycol, 5 g of White Spirit® 17/18 and, to finish, a solution of 75g of Coatex® BR 100 and 23.2 g of water are added. The mixture is then stirred further for about 5 minutes more.

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Before being used, the paint is stored for at least one more day at room temperature. 5S The following additive is added to the dispersion before it is added to the colorant paste:

Table 2

Example | Dispersion Additive/added amount of active substance in % by weight based on dispersion ob] Mowilith® LDM 7977 (Clariant) | Fluowet® OTL / 0.1

Mowilith® LDM 7977 (Clariant) | Zonyl® FSA /0.1 a Mowilith® LDM 7977 (Clariant) | Example 1a/0.1 oe Mowilith® LDM 7977 (Clariant) | Example 1b/0.1

Mowilith® LDM 7977 (Clariant) | Fluowet® OTL / 0.2

IE Mowilith® LDM 7977 (Clariant) | Zonyl® FSA /0.2

Mowilith® LDM 7977 (Clariant) | Example 1a/0.2 i] Mowilith® LDM 7977 (Clariant) | Example 1b/0.2

Example 3

Determination of the dry soiling tendency of the masonry coatings

Soiling was effected using the fly ash/soot mixture described above in the context of the measurement methods.

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Table 3 ‘Coating material

Example 2a

Example 2b

Example 2d

As is apparent from table 3, even very small added amounts show a distinct improvement in the dry soiling tendency.

Example 4

Determination of the water absorption of the masonry coatings

Table4

Coating material 1st water absorption [%] | 2nd water absorption [%]

As table 4 shows, the coatings with the organosilanes of the invention exhibit a reduced water absorption as compared with those where the addition is a non-reactive fluoroemulsifier.

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Example 5

Determination of the wet soiling tendency of the masonry coatings

Table 5

Coating 1st cycle | 2nd cycle | 3rd cycle | 4thcycle | 5th cycle material [AL*] [AL¥] [AL*] [AL*] [AL*]

As table 5 shows, the organosilanes of the invention lead to an improved early wet soiling tendency in the coatings, compared with additives having surfactant character but without reactive functionality.

Example 6

Various additives for reducing the soiling tendency are added to a

Mowilith® LDM 6636 (Clariant) dispersion and the mixture is homogenized with a paddle stirrer for 10 minutes. Thereafter the respective mixture is applied to a glass plate using a 300 um box-type coater bar and dried at room temperature for 24 hours.

oo 16

Table 6

Mixture Amount added Blushing (% by weight of active substance based on dispersion)

LDM 6636 / Fluowet® 0.2 4

OTL

As table 6 shows, the organosilanes of the invention produce an increase and not, like the prior art additives, a reduction in the water resistance.

Example 7

Preparation of an exterior paint

Dissolved in succession in 130 g of water are 2 g of Tylose® MH 4000

KG 4 (Clariant), 3 g of Mowiplus® XW 330 (Clariant), 11 g of Calgon® N (10% strength by weight), and 2 g of 25% aqueous ammonia. Following the addition of 2 g of Mergal® K10N (from Troy), 4 g of Agitan® 232 (Minzing) and then 226 g of titanium dioxide Kronos® 2065 (Kronos Titan), 168 g of

Omyacarb® 5 GU, 38g of Micro Talc AT1 and 20 g of China Clay are added and the mixture is sheared with the dissolver disk at 5000 rpm for 15 minutes. Subsequently 375g of Mowilith® LDM 6636 (Clariant) are introduced at 500 rpm. The dispersion is admixed where appropriate with a dirt-repellent additive, which is incorporated into the dispersion beforehand using a paddle stirrer. Finally 11 g of white spirit and 8 g of butyl diglycol acetate are added and stirring is continued for about 10 minutes more.

Claims (25)

Claims

1. An organosilane of the general formula (h 0 R1 R4 RO NT si (1) ™~ R3 Yoox R? where R is a fluorinated or partly fluorinated alkyl radical of the formula CnZ2n+1(CH2)m-, with n > 1, m > 1, and Z either a hydrogen atom or a fluorine atom, with the proviso that at least one Z is a fluorine atom, Ys a hydrogen atom or alkyl radical having 1 to 10 carbon atoms, X is alternatively a hydrogen atom, a linear or branched alkyi radical having 1 to 10 carbon atoms, a radical of the formula ROC(O)(CHY)(CHa)-, a phenyl radical or a benzyl radical, rR’ is a linear or branched alkylene radical having 1 to 20 carbon atoms, and RZ, rR®, and rR are linear or branched alkyl radicals having 1 to 10 carbon atoms or linear or branched alkoxy radicals having 1 to 10 carbon atoms, which are attached via the oxygen atom to the silicon atom.

2. An organosilane as claimed in claim 1, wherein R is a fluorinated alkyl radical of the formula CnF2n+1(CH2)m-.

3. An organosilane as claimed in claim 1 or 2, wherein n = 1 to 30 and m=1to4.

4. An organosilane as claimed in at least one of the preceding claims, wherein Xis a methyl, an ethyl, a propyl, a phenyl or a benzyl radical, Y is a hydrogen atom or a methyl radical, Ris a-(CHp)z-, a -CH2CH(CH3)CHy- or a -CoHs- radical, and R®, R®,and R” are a CH30-, a CHs0- or a CH(CHa),0- radical.

5. An organosilane as claimed in at least one of the preceding claims, whereinn=61to 14 and m = 2.

6. An organosilane as claimed in claim 4 or 5, wherein Xs an ethyl radical, rR is a -CH2CH(CH3)CH>- radical, and R% R3 and R* are a CH30- radical.

7. An organosilane as claimed in claim 4 or 5, wherein X is a methyl radical, R'is a -(CHa)3- radical, and RZ, R3 and rR are a CH30- radical.

8. A process for preparing an organosilane of the general formula (I) as claimed in at least one of the preceding claims, which comprises reacting a (meth)acrylic ester of the general formula (II) with an w-aminoalkylsilane of the general formula (ill), 0) R4 (H) oF Se we a) ~ Y X R? where R is a fluorinated or partly fluorinated alkyl radical of the formula CnZ2n+1(CH2)m-, with n > 1, m > 1, and Z either a hydrogen atom or a fluorine atom, with the proviso that at least one Z is a fluorine atom, Y is a hydrogen atom or alkyl radical having 1 to 10 carbon atoms, X is alternatively a hydrogen atom, a linear or branched alkyl radical having 1 to 10 carbon atoms, a radical of the formula ROC(O)CHY)CHa)-, a phenyl radical or a benzyl radical, R is a linear or branched alkylene radical having 1 to 20 carbon atoms, and rR? RS and RY are linear or branched alkyl radicals having 1 to 10 carbon atoms or linear or branched alkoxy radicals having 1 to 10 carbon atoms, which are attached via the oxygen atom to the silicon atom.

9. The use of an organosilane as claimed in at least one of claims 1 to 7 for reducing the soiling tendency of surfaces.

10. The use of an organosilane as claimed in at least one of claims 1 to 7 as an antiblocking agent for the treatment of surfaces.

red . «on 22

11. The use of an organosilane as claimed in at least one of claims 1 to 7 for the hydrophobicization and oleophobicization of surfaces.

12. A method of coating surfaces, which comprises spraying an organo- silane as claimed in at least one of claims 1 to 7 as it is, in solution or in dispersion onto the surfaces to be treated, immersing the surface into the solution or dispersion of the additives, or applying it with a brush or by roller, or adding it to a coating composition to be applied, as it is, in solution orin dispersion, and applying the coating composition to the surface.

13. The use of an organosilane as claimed in at least one of claims 1 to 7 in a coating composition for reducing the soiling tendency of surfaces.

14. The use of an organosilane as claimed in at least one of claims 1 to 7 as an antiblocking agent in a coating composition for the treatment of surfaces.

15. The use of an organosilane as claimed in at least one of claims 1 to 7 in a coating composition for the hydrophobicization and oleophobicization of surfaces.

16. A coating composition comprising: a) at least one polymeric binder, Db) atleast one organosilane as claimed in at least one of claims 1 to 7, and c) if desired, pigments, fillers, dispersants, thickeners, protective colloids, wetting agents, preservatives, algicides, anticorrosion pigments, UV filter substances, UV initiators and/or further auxiliaries.

17. A coating composition as claimed in claim 16, comprising at least one UV initiator.

18. A coating composition as claimed in claim 16 or 17, wherein the at least one polymeric binder comprises at least one o-hydroxyalkyl (meth)acrylate as monomeric building block (comonomer) and at least one epoxyalkylsilane of the formula BSiR3, the radical B being an organic radical having at least one oxirane functionality and the radicals R being alkyl or alkoxy groups of the formula -CnH2n+1 or -OCnH2p+1 respectively, in which n = 1 to 10.

I 5 N \ AS ~ } 23

19. A coating composition as claimed in claim 18, wherein as w-hydroxyalkyl (meth)acrylate 2-hydroxyethyl methacrylate is used. 5S 20. A coating composition as claimed in claim 18 or 19, wherein as ~ epoxyalkylsilane B-(3.4-epoxycyclohexyl)ethyitriethoxysilane or y-glycidyl- oxypropyltrimethoxysilane is used.

23/A

21. An organosilane as claimed in claim 1, substantially as herein described and exemplified and/or described with reference to the examples.

22. The process as claimed in claim 8, substantially as herein described and exemplified and/or described with reference to the examples.

23. The use as claimed in claim 9, substantially as herein described and exemplified and/or described with reference to the examples.

24. The method as claimed in claim 12, substantially as herein described and exemplified and/or described with reference to the examples.

25. The coating composition as claimed in claim 16, substantially as herein described and exemplified and/or described with reference to the examples. AMENDED SHEET