WO2019090456A1

WO2019090456A1 - An anti-graffiti coating composition

Info

Publication number: WO2019090456A1
Application number: PCT/CN2017/109656
Authority: WO
Inventors: Shenggang(Mark) SHA
Original assignee: Wacker Chemie Ag
Priority date: 2017-11-07
Filing date: 2017-11-07
Publication date: 2019-05-16
Also published as: CN111417692A; CN111417692B

Abstract

A coating composition, which is one-component or two-component, comprising an alkoxy- functional silicone resin, a hydroxy silicone oil having a dynamic viscosity of not more than 1,000 mPa·s at 25°C, an aminosilane, and a catalyst, wherein the alkoxy-functional silicone resin and the hydroxyl silicone oil are in different components in a two-component coating composition. The coating composition herein is silicone-based and has excellent anti-graffiti and anti-stick properties. Moreover, the coating composition can be solvent free.

Description

An Anti-graffiti Coating Composition

Field of the Invention

The present invention relates to the field of coatings, and specifically to an anti-graffiti coating composition.

Background of the Invention

In the recent years, graffiti damage has been an increasingly growing concern. All sorts of spray graffiti and unapproved posters are rampant in public places from public transport, such as subways, trains and buses, to public facilities, such as bus shelters, power poles and exterior walls. They are not only a smudge upon the urban landscape, but also cause damage to the building fabric to some extent. Nowadays, it is costly to remove graffiti in public places, but at the same time it is unrealistic to reduce the amount of graffiti in any country. On the other hand, it is natural for children to doodle on the walls at home, and their markers and oily pens are typically more erosive than spray paints, which is always a distress to parents. Therefore, there is a need to develop anti-graffiti coatings which enable the easy removal of graffiti therefrom, for example, by simply wiping with a damp cloth or even a paper towel/dry cloth.

At present, anti-graffiti products commercially available are typically fluororesin coatings, water-based crosslinked coatings containing fluorine compounds, polyurethane coatings, and silicone modified coatings. Silicone modified coatings are a type of anti-graffiti products obtained by modifying common coatings with silicones as an additive/auxiliary. Polysiloxanes, due to their excellent hydrophobicity, oleophobicity and lubricity, can be used in coatings to significantly reduce the surface energy of the coating films. It is found that low-energy surface can prevent graffiti from adhering and contaminating. Therefore some researches on silicone-modified anti-graffiti coatings have been reported.

CN101585995A discloses an acrylic resin-based, silicone-modified two-component anti-graffiti coating comprising Components A and B, wherein Component A comprises a hydroxyacrylic resin, a fluorocarbon resin, a modified polydimethylsiloxane resin, a polyacrylate-modified silicone resin, a free flow agent, a leveling agent, a defoamer, a drier, dibutyltin dilaurate, butyl acetate and xylene; and Component B comprises hexamethyl diisocyanate biuret, butyl acetate and ethylene glycol ether acetate. The silicone-modified coating forms a film that protects against graffiti and posters, on which the graffiti applied with oily pens and spray paints can be wiped off with a lint-free cotton cloth dipped in a citrus-based cleaning agent. However, the coating contains organic solvents and VOCs.

US 9328259B discloses an elastomeric silicone emulsion used as an anti-graffiti modifier for PVC coatings, and Example 2 therein discloses that the modifier comprises a silicon-terminated polyether, an alkoxy-containing polysiloxane, an emulsifier, and water. PVC coatings modified with the elastomeric silicone emulsion exhibit excellent tensile strength and elongation. Although US9328259B also qualitatively describes that the modified PVC coatings can resist graffiti, it comes short of characterizing this performance. In addition, the modified PVC coating film tends to be tacky, which is easy to collect dusts and is less stick-resistant.

EP1083195A discloses an alkoxylated resin-polymer organosiloxane network which can be used as an additive for anti-graffiti coatings, and Example 11 therein discloses a method comprising the following steps of: i) mixing hydroxyl-terminated polydimethylsiloxane having a kinematic viscosity of 75 mm²/s at 25℃, 74 wt%^methyl MQ silicone resin in xylene, and 25 wt%sodium methoxide (NaOMe) in methanol; ii) adding in methyltrimethoxysilane, hexamethyldisiloxane and aminosilane for reaction; and iii) adding a neutralizing agent to the above reaction product. Although EP1083195A discloses that the organosiloxane network has excellent tensile strength and generally describes the possibility of using it as an additive for anti-graffiti coatings, it makes no further discussions about its graffiti resistance.

To achieve the desired anti-graffiti effects of the anti-graffiti coatings mentioned above in which silicones are used as an additive, considerations should be given to the following issues: Are the silicones compatible with the coating system to be modified? Can the silicones be quickly mixed into the coating system to be modified? Do the silicones have any negative impact on other properties of the coatings, and Can the silicones provide the films with good resistance to posters and dusts in the long term. These issues, if not well resolved, will affect the resistance to graffiti and posters of the coatings. In order to avoid the possible negative effects of silicone additives on the coating system to be modified, further investigations have been made on silicone-based anti-graffiti coatings.

US 8772407B discloses a silicone-based one-component coating composition and Comparative Example 6 therein discloses a coating composition comprising a hydroxyl-functional silicone resin (Dow Corning 805) , an alkoxy-functional silicone resin (Dow Corning 3074) , an aminosilane and an organotin catalyst, wherein Dow Corning 805 is a hydroxyl-functional silicone resin diluted with xylene and having a resin content of 50 wt%and a VOC content of 503 g/L. Although the Background Information of the US 8772407B discloses that the polysiloxane coating is graffiti-resistant, it does not characterize the graffiti resistance of the coating composition of Comparative Example 6.

US 8277555B discloses a silicone-based one-component anti-graffiti coating composition, and Examples 1-3 therein disclose that the composition comprises: a) a mixture of methyl silicone resin containing 31 wt%alkoxy and methylphenylsilicone resin containing 18 wt%alkoxy, b) an organotin catalyst, c) an aminosilane, and d) a glycidyl-containing compound. The coating composition has an anti-graffiti effect against markers, oily pens and spray paints, but it does not provide an easy way to remove graffiti for it requires a solvent to do so.

WO2011120735A discloses a silicone-based one-component anti-graffiti coating composition, and Example 3 therein discloses that the composition comprises an aqueous solution of 15 wt%oligomeric aminofluoroalkyl organosiloxane, an ethylene oxide-propylene oxide block copolymers, and water. The composition has improved film-forming property and produces an anti-graffiti film on substrates to resist markers and spray paints. However, the removal of the graffiti is not easy and involves the application of N-methylpyrrolidone (NMP) on the graffiti for 10 minutes before rinsing with water and gently brushing the surface. Moreover, the film is likely to be damaged while the graffiti is being removed.

Summary of the Invention

In view of the problems in the above-mentioned background that the existing silicone modified anti-graffiti coatings and silicone-based anti-graffiti coatings usually contain organic solvents, where the VOC content cannot meet the environmental requirements, and that the graffiti resistance is not satisfactory, especially the fact that the removal of graffiti is not easy as it involves the use of a solvent and is likely to damage the films, the present invention hereby provides a coating composition that has excellent anti-graffiti and anti-stick properties and can be solvent free.

As used herein, the term “one-component coating” , also known as one-package coating or one-pack coating, refers to a coating comprising one component that is stored in one package and cures into a film when the package is opened for use.

As used herein, the term “two-component coating” , also known as two-package coating or two-pack coating, refers to a coating comprising two components that are stored in separate packages and cures into a film until they are mixed in a specific ratio for use.

As used herein, the term “anti-graffiti” has two meanings: 1) repelling water and oils with the low surface energy of the coatings, making it impossible to make graffiti on the coatings with spray paints, markers, oily pens, or the like; 2) easily removing graffiti on the coatings made with spray paints, markers, oily pens, or the like, virtually without remaining any trace.

As used herein, the term “anti-stick” means that adhesive tapes adhered to the coating film are easily peeled off and no flaking, significant loss of gloss and glue residues are visually inspected on the coating film even after more than 50 sticking-peeling cycles within the same area on the film.

As used herein, the term “silicone resin” refers to a thermoset polysiloxane system having a highly crosslinked structure, whose R/Si value (i.e., the average number of organic groups attached to a silicon atom) is less than 2, usually between 1.0 and 1.7, which can generally be obtained by the hydrolysis and condensation of difunctional and trifunctional organosilanes (e.g. MeSiCl₃, Me₂SiCl₂, MePhSiCl₂, PhSiCl₃) .

As used herein, the term “alkoxy-functional silicone resin” refers to a silicone resin containing at least one alkoxy group directly attached to a silicon atom.

As used herein, the term “aminosilane” refers to an organosilicon compound containing at least one aminoalkyl group directly attached to a silicon atom and at least one hydrolyzable group directly attached to the silicon atom.

As used herein, the term “epoxy silane” refers to an organosilicon compound containing at least one epoxy group or episulfide group directly attached to a silicon atom and at least one hydrolyzable group directly attached to the silicon atom.

As used herein, the term “alkoxysilane” refers to an organosilicon compound containing at least one alkoxy group directly attached to a silicon atom and at least one non-hydrolyzable group directly attached to the silicon atom.

As used herein, the term “hydroxy silicone oil” refers to a linear polysiloxane having at least one terminal hydroxyl group, which remains in liquid state at room temperature.

As used herein, the term “catalyst” refers to a compound capable of catalyzing the curing reaction of coating compositions.

As used herein, the term “polyether” refers to a polymer containing a [-C-O-C-] _n ether bond in its molecular chain, whose general formula is typically:

where R₁ and R₄ can be H, alkyl or acyl independently; and R₂ and R₃ can be H or alkyl independently.

As used herein, the term “polyether” , on the one hand, refers to a group of chemically identical macromolecules that have the above general formula but differ in degree of polymerization, molar mass and chain length, and are usually prepared by the ring-opening homopolymerization or copolymerization of ethylene oxide (EO) , propylene oxide (PO) and butylene oxide (BO) as the main ingredients; on the other hand, the term includes the derivatives of such a group of macromolecules from polymerization reactions. The number average molecular weight (Mn) of the polyethers herein ranges suitably from 2,000 to 22, 500 g/mol.

As used herein, the term “silane-terminated polyether” refers to a polyether with most of its active groups at the end of the polyether molecular chains substituted by small silane molecules through etherification, esterification or crosslinking reactions. The word “most” here means that more than 80%of the active terminal groups at the end of the polyether molecular chains are substituted by silane functional groups, and preferably more than 85%, more than 90%, or more preferably more than 95%of the active terminal groups are substituted by silane functional groups. The small silane molecules suitable for termination have the functional groups that react with the active groups at the end of the polyether molecular chains, such as isocyanates. The small silane molecules used for termination are preferably α-silanes, including difunctional α-silanes and trifunctional α-silanes.

As used herein, the term “room temperature” has a technical meaning well known in the art and is generally in the range of 23±2℃.

As used herein, the term “dynamic viscosity” is measured at 25℃ according to DIN 51562, unless otherwise specified.

As used herein, the term “kinematic viscosity” is measured at 25℃ according to DIN 51562, unless otherwise specified.

The first aspect of the present invention provides a coating composition comprising the following ingredients:

an alkoxy-functional silicone resin, a hydroxy silicone oil, an aminosilane and a catalyst.

The coating composition can be a one-component system, i.e., the alkoxy-functional silicone resin, hydroxy silicone oil, aminosilane and catalyst are stored in one package. The one-component system should be water free so as to prevent the alkoxy-functional silicone resin from reacting with the hydroxy silicone oil, which will affect the use of the coating. The word “water free” means that the amount of water included in the system is less than 0.1 wt%, even less than 0.01 wt%, or further even less than 0.001 wt%, based on the total weight of the coating composition. During the curing of the one-component coating composition, the alkoxy groups react with the hydroxyl groups in the system in the presence of the catalyst, and the alkoxy groups also cure upon contact with atmosphere moisture through hydrolysis and condensation reactions in the presence of the catalyst. In order to facilitate the curing of the coating composition, the number of moles of alkoxy groups in the component is significantly greater than that of hydroxyl groups.

The coating composition can also be a two-component system, i.e. the alkoxy-functional silicone resin, hydroxy silicone oil, aminosilane and catalyst are stored in two separate packages; specifically, the alkoxy silicone resin and hydroxy silicone oil are stored in different packages, while the aminosilane and catalyst can optionally be stored in the same package, or in different packages or in both packages. When the two components are mixed, the alkoxy groups in one component react with the hydroxyl groups in the other component in the presence of the catalyst to cure into a film; and the alkoxy groups in one component also cure upon contact with atmosphere moisture through hydrolysis and condensation reactions in the presence of the catalyst. In order to facilitate the curing of the coating composition, the number of moles of alkoxy groups in one component is significantly greater than that of hydroxyl groups in the other component. In the present invention, a two-component system is preferred for the storage of the coating composition. The two-component system herein can contain less or no water, for example, the component comprising the hydroxy silicone oil contains less than 2 wt%of water and the component comprising the alkoxy-functional silicone resin contains less than 0.1 wt%of water based on the total weight of the coating composition.

Moreover, for higher flexibility of coating films and easier application of the coating composition on ductile substrates such as metals, the coating composition herein can further comprise a silane-terminated polyether. Because the silane-terminated polyether is quite reactive, the coating composition containing a silane-terminated polyether is preferably a two-component system, wherein the silane-terminated polyether and hydroxy silicone oil are included in different components. In one embodiment herein, the coating composition comprises the following ingredients: an alkoxy-functional silicone resin, a silane-terminated polyether, a hydroxy silicone oil, an aminosilane and a catalyst, wherein the alkoxy-functional silicone resin and silane-terminated polyether are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) . When the content of the silane-terminated polyether is low, for example, less than 6 wt%, such as 5 wt%, 4 wt%, 3 wt%, 2 wt%or 1 wt%, based on the total weight of the coating composition, such coating composition containing the silane-terminated polyether can also be a one-component system.

Moreover, in order to facilitate the curing of the coating composition and improve the adhesion of the coating film to inorganic substrates, the coating composition herein can further comprise an epoxy silane, and such coating composition containing the epoxy silane can be a one-component system or a two-component system. In the two-component system, the epoxy silane and hydroxy silicone oil are preferably included in different components. In one embodiment herein, the coating composition comprises the following ingredients: an alkoxy-functional silicone resin, an epoxy silane, a hydroxy silicone oil, an aminosilane and a catalyst, wherein the alkoxy-functional silicone resin and epoxy silane are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) .

Moreover, in order to facilitate the dispersion of the ingredients for better leveling and application of the coating, the coating composition herein can further comprise an alkoxysilane, and such coating composition containing the alkoxysilane can be a one-component system or a two-component system. In the two-component system, the alkoxysilane and the hydroxy silicone oil are preferably included in different components. In one embodiment herein, the coating composition comprises the following ingredients: an alkoxy-functional silicone resin, an alkoxysilane, a hydroxy silicone oil, an aminosilane and a catalyst, wherein the alkoxy-functional silicone resin and alkoxysilane are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) .

In one preferred embodiment herein, the coating composition comprises the following ingredients: an alkoxy-functional silicone resin, a silane-terminated polyether, an epoxy silane, a hydroxy silicone oil, an aminosilane and a catalyst, wherein the alkoxy-functional silicone resin, silane-terminated polyether and epoxy silane are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) . In another preferred embodiment herein, the coating composition comprises the following ingredients: an alkoxy-functional silicone resin, a silane-terminated polyether, an epoxy silane, an alkoxysilane, a hydroxy silicone oil, an aminosilane and a catalyst, wherein the alkoxy-functional silicone resin, silane-terminated polyether, epoxy silane and alkoxysilane are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) .

Alkoxy-functional silicone resins

In the present invention, the alkoxy-functional silicone resins can be any known organosilicone resins having alkoxy functional groups in the art, including alkoxy-functional silicone resins having a highly branched molecular structure, a network molecular structure or a clathrate molecular structure. Typically, silicone resins have the following general formula:

(M) _a (D) _b (T) _c (Q) _d (I)

where, M represents a monofunctional siloxane unit R₃SiO_1/2; D represents a difunctional siloxane unit R₂SiO_2/2; T represents a trifunctional siloxane unit RSiO_3/2; and Q represents a tetrafunctional siloxane unit SiO_4/2;

where, at least one of a, b, c and d is non-zero; and

where, the R group in M, D, T and Q can be a functional group, a non-functional group or a combination thereof; for example, it can be an alkyl group such as methyl, ethyl, propyl, butyl, pentyl, heptyl, octyl, undecyl or octadecyl; an aryl group such as phenyl, tolyl, xylyl, benzyl or 2-phenylethyl; an alkenyl group such as vinyl, propenyl, butenyl or hexenyl; or an alkynyl group such as ethynyl, propynyl or butynyl.

The alkoxy-functional silicone resins herein can include any one, or a combination, of the structural units M, D, T and Q. For example, the alkoxy-functional silicone resins can include MD resins containing the structural units M and D, MT resins containing the structural units M and T, MQ resins containing the structural units M and Q, DT resins containing the structural units D and T, and MDT resins containing the structural units M, D and T. The alkoxy-functional silicone resins are preferably alkoxy-terminated DT resins and/or T resins. In one embodiment herein, the surface of the alkoxy-terminated DT resin or T resin contains alkyl or aryl substituents having 6 or more carbon atoms, for example, phenyl, hexyl (e.g. n-hexyl) , heptyl (e.g. n-heptyl) , octyl (e.g. n-octyl, and isooctyl such as 2, 4, 4-trimethylpentyl) , to improve the alkali resistance and durability of the coating composition.

The alkoxy-functional silicone resins herein have a number average molecular weight (Mn) of suitably less than 2,000 g/mol, for example, from 400 to 2,000 g/mol (e.g. from 400 to 700 g/mol, from 700 to 1,000 g/mol, from 1,000 to 1, 500 g/mol, or from 1, 500 to 2,000 g/mol) , or have a kinematic viscosity at 25℃ of suitably less than 500 mm²/s, for example, from 100 to 500 mm²/s (e.g. from 100 to 250 mm²/s, from 250 to 350 mm²/s, or from 350 to 500 mm²/s.

The amount of the alkoxy-functional silicone resins herein is suitably from 38 to 95 wt%based on the total weight of the coating composition, for example, 38 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%or 95 wt%, preferably from 50 to 90 wt%, and more preferably from 60 to 80 wt%.

Hydroxy silicone oils

The hydroxy silicone oils herein can be any hydroxy silicone oils known in the art, which typically have the following general formula:

where, R and R’can each independently be an alkyl or aryl group;

X can be a hydroxy, hydrogen, halogen, alkyl, aryl or alkenyl group;

n is non-zero while m can be zero; and

the dynamic viscosity of the hydroxy silicone oils (in an undiluted state) at 25℃ is suitably not more than 1,000 mPa·s, preferably not more than 300 mPa·s, and more preferably not more than 150 mPa·s,

wherein R and R’can each independently be an alkyl group such as methyl, ethyl, propyl (e.g. n-propyl, isopropyl) , butyl (e.g. n-butyl, isobutyl, t-butyl) , pentyl (e.g. n-pentyl, isopentyl, neopentyl, t-pentyl) , hexyl (e.g. n-hexyl) , heptyl (e.g. n-heptyl) , octyl (e.g. n-octyl, and isooctyl) , nonyl (e.g. n-nonyl) , decyl (e.g. n-decyl) , and dodecyl (e.g. n-dodecyl) ; or an aryl group such as phenyl and naphthyl; and R and R’are each preferably a C₁-C₆ alkyl group, particularly preferably a methyl or ethyl group, and more preferably a methyl group;

wherein X can be a hydroxy group; hydrogen; a halogen (e.g. chlorine and bromine) ; an alkyl group, especially a C₁-C₆ alkyl group (e.g. methyl, ethyl, propyl, butyl, pentyl and hexyl) , an aryl group (e.g. phenyl and naphthyl) ; or an alkenyl group, especially a C₂-C₄ alkenyl group (e.g. vinyl, propenyl and butenyl) ; and X is preferably a hydroxyl group; and

wherein n+m equals to such an integer that the dynamic viscosity of the hydroxy silicone oil at 25℃ is less than 1,000 mPa·s, and especially n+m is an arbitrary integer between 5 and 99, for example, 5, 10, 15, 20 50, 55, 65, 65, 70, 75, 80, 85, 90, 95 or 99.

In formula II, when each of R and R’is a methyl group and X is a hydroxyl group, said silicone oil is a dihydroxyl-terminated methyl silicone oil. R and R’can also be substituted by other organic groups described above, such as ethyl and phenyl, to improve a certain performance of the silicone oils. The hydroxy silicone oils herein are hydroxy-terminated silicone oils, of which preferably more than 80%of R and R’groups are methyl groups, and more preferably almost 100%of R and R’group are methyl groups.

The hydroxyl content of the hydroxy-terminated silicone oils herein is suitably in the range of from 1 to 5 wt%, for example from 1.5 to 2.5 wt%, based on the total weight of the hydroxy-terminated silicone oils. A lower hydroxyl content of the silicone oil usually will lead to a higher viscosity of the silicone oil and a poor compatibility with the other component, resulting in uneven condensation curing within the coating and inferior hardness of the coating film. In one preferred embodiment herein, the hydroxy silicone oil is a dihydroxy-terminated methyl silicone oil having a dynamic viscosity of from 50 to 110 mPa·s at 25℃ and a hydroxyl content of from 1.6 to 2.2 wt%.

The amount of the hydroxy silicone oils herein is suitably from 5 to 15 wt%based on the total weight of the coating composition, for example, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%or 15 wt%, preferably from 8 to 12 wt%.

Silane-terminated polyethers

The coating compositions herein can also comprise silane-terminated polyethers for higher flexibility of the coating film and easier application of the coating composition on ductile substrates such as metals. The silane-terminated polyethers have the following general formula:

where, R₂ and R₃ can each independently be H or an alkyl group;

R^a and R^b can each independently be a hydrocarbon group having from 1 to 18 carbon atoms or an ω-oxaalkyl-alkyl group having a total of from 2 to 20 carbon atoms;

X can be -CH₂-, -CH₂NHC (=O) -, - (CH₂) ₃-, or - (CH₂) ₃NHC (=O) -, wherein X is bonded via Si-C;

n can be an arbitrary integer between 1 and 300; and

m is 2 or 3,

wherein R₂ and R₃ can each independently be H, or an alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, neopentyl and t-pentyl, especially a C₁-C₄ alkyl group, and preferably a methyl group;

wherein R^a and R^b can each independently be an alkyl group, such as methyl, ethyl, propyl (e.g. n-propyl, isopropyl) , butyl (e.g. n-butyl, isobutyl, t-butyl) , pentyl (e.g. n-pentyl, isopentyl, neopentyl, t-pentyl, hexyl (e.g. n-hexyl) , heptyl (e.g. n-heptyl) , octyl (e.g. n-octyl, and isooctyl) , nonyl (e.g. n-nonyl) , decyl (e.g. n-decyl) , and dodecyl (e.g. n-dodecyl) ; an alkenyl group such as vinyl and allyl; a cycloalkyl group such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl; an aryl group such as phenyl and naphthyl; an alkaryl group such as o-, m-, p-tolyl, xylyl and ethylphenyl; or an aralkyl group such as benzyl, α-and β-phenylethyls; R^a and R^b are each independently a hydrocarbon group preferably having from 1 to 12 carbon atoms, particularly an alkyl group having from 1 to 6 carbon atoms, and especially an alkyl group having from 1 to 4 carbon atoms; and R^b is more preferably a methyl group or an ethyl group, and R^a is more preferably a methyl group;

wherein X is preferably -CH₂NHC (=O) -or - (CH₂) ₃NHC (=O) -, and more preferably -CH₂NHC (=O) -; and

wherein n can be an arbitrary integer between 1 and 300, such as 2, 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275 or 300, suitably an arbitrary integer between 20 and 200.

The silane-terminated polyethers herein have a number average molecular weight (Mn) of suitably from 2, 500 to 23,000 g/mol, preferably from 2, 500 to 15,000 g/mol, or have a dynamic viscosity at 25℃ (in an undiluted state) of suitably not more than 50 Pa·s, and preferably not more than 35 Pa·s.

In one embodiment herein, the silane-terminated polyether has the following general formula:

where, R₂ and R₃ are each independently H or a C₁-C₄ alkyl group;

R^a and R^b are each independently a hydrocarbon group having from 1 to 12 carbon atoms;

X is -CH₂-, -CH₂NHC (=O) -, - (CH₂) ₃-, or - (CH₂) ₃NHC (=O) -, wherein X is bonded via Si-C;

n is an arbitrary integer between 20 and 200; and

m is 2 or 3.

In another embodiment herein, the silane-terminated polyether has the following general formula:

where, R₂ and R₃ are each independently a methyl or ethyl group;

n is an arbitrary integer between 20 and 200; and

m is 2 or 3.

In yet another embodiment herein, the silane-terminated polyether has the following general formula:

where, R₂ and R₃ are each independently H or a C₁-C₄ alkyl group;

R^a and R^b are each independently a hydrocarbon group having from 1 to 6 carbon atoms;

n is an arbitrary integer between 20 and 200; and

m is 2 or 3.

In still another embodiment herein, the silane-terminated polyether has the following general formula:

where, R₂ and R₃ are each independently H or a C₁-C₄alkyl group;

X is -CH₂NHC (=O) -, or - (CH₂) ₃NHC (=O) -, wherein X is bonded via Si-C;

n is an arbitrary integer between 20 and 200; and

m is 2 or 3.

In one preferred embodiment herein, the silane-terminated polyether has the following general formula:

where, R₂ and R₃ are each independently a methyl or ethyl group;

R^a and R^b are each independently a hydrocarbon group having from 1 to 4 carbon atoms;

X is -CH₂NHC (=O) -or - (CH₂) ₃NHC (=O) -, wherein X is bonded via Si-C;

n is an arbitrary integer between 20 and 200; and

m is 2 or 3.

In one more preferred embodiment herein, the silane-terminated polyether has the following general formula:

where R₂ and R₃ are a methyl group;

R^a is a methyl group;

R^b is a methyl or ethyl group;

X is -CH₂NHC (=O) -, wherein X is bonded via Si-C;

n is an arbitrary integer between 20 and 200; and

m is 2 or 3.

Examples of commercially available products of suitable silane-terminated polyethers herein include, but are not limited to,

STP-E10,

STP-E15,

STP-E30 and

STP-E35.

The amount of silane-terminated polyether herein can be less than 25 wt%based on the total weight of the coating composition, suitably from 2 to 25 wt%, such as 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%or 25 wt%, preferably from 8 to 22 wt%, and more preferably from 14 to 18 wt%.

Aminosilanes

The aminosilanes herein refer to an organosilicon compound containing at least one aminoalkyl group directly attached to a silicon atom and at least one hydrolyzable group directly attached to the silicon atom, wherein the amino group includes primary amino group, secondary amino group and tertiary amino group, preferably primary amino group and secondary amino group, and examples of hydrolyzable groups include halogen (F, Cl, Br, I, particularly Cl and Br) , alkoxy (particularly C1-C4 alkoxy, such as methoxy, ethoxy, n-propoxy, isopropoxy and butoxy) , aryloxy (particularly C6-C10 aryloxy, such as phenoxy) , acyloxy (particularly C1-C4 acyloxy, such as acetoxy and propionyloxy) and alkylcarbonyl (e.g., acetyl) , but are not limited thereto, and particularly preferred are alkoxy groups, especially methoxy and ethoxy groups.

Suitable aminosilanes herein can be exemplified by N- (2-aminoethyl) -3-aminopropyl-trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl-methoxysilane, 3-aminopropyl-trimethoxysilane, 3-aminopropyl-methyldimethoxysilane, 3-amino-2-methylpropyl-trimethoxysilane, 4-amino-3-methylbutyl-trimethoxysilane, 4-amino-3, 3-dimethylbutyl trimethoxysilane, 4-amino-3, 3-dimethylbutyl-methyldimethoxysilane, 2-aminoethyl-trimethoxysilane, 2-aminoethyl-methyldimethoxysilane, aminomethyl-trimethoxysilane, aminomethyl-methyldimethoxysilane, aminomethyl-dimethylmethoxysilane, 7-amino-4-oxaheptyl dimethoxy methylsilane, N-cyclohexylaminomethyltrimethoxysilane, cyclohexylaminomethylmethyldimethoxysilane, and homologues of the above-mentioned aminosilanes with ethoxy or isopropoxy groups instead of methoxy groups, but are not limited thereto. The aminosilanes are preferably N- (2-aminoethyl) -3-aminopropyl-trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl-dimethoxymethylsilane, (2-aminoethyl) -3-aminopropyl-triethoxysilane, 3-aminopropyl-trimethoxysilane, 3-aminopropyl-triethoxysilane, or 4-amino-3, 3-dimethylbutyl-trimethoxysilane.

The total amount of the aminosilanes used herein is suitably from 0.5 to 4 wt%based on the total weight of the coating composition, for example, 0.5 wt%, 0.8 wt%, 1.2 wt%, 1.6 wt%, 2.0 wt%, 2.4 wt%, 2.8 wt%, 3.2 wt%, 3.6 wt%or 4 wt%, preferably from 0.5 to 2.5 wt%.

Epoxy silanes

The coating composition herein can further comprise epoxy silanes to facilitate the curing of the coating composition and improve the adhesion of the coating film to the inorganic substrates. The epoxy silane refers to an organosilicon compound containing at least one epoxy group or episulfide group directly attached to a silicon atom and at least one hydrolyzable group directly attached to the silicon atom, wherein typical examples of the epoxy groups include glycidyl, glycidyloxy and epoxycyclohexyl, but are not limited thereto, and examples of hydrolyzable groups are listed in the aminosilane section.

Suitable epoxy silanes herein can be exemplified by 3- (2, 3-epoxypropoxy) propyltrimethoxysilane, 3- (2, 3-epoxypropoxy) propylmethyldimethoxy silane, 3- (2, 3-epoxypropoxy) propyltriethoxysilane or 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, but are not limited thereto.

The amount of the epoxy silane herein can be less than 4 wt%, suitably from 0.5 to 4 wt%, based on the total weight of the coating composition, for example, 0.5 wt%, 0.8 wt%, 1.2 wt%, 1.6 wt%, 2.0 wt%, 2.4 wt%, 2.8 wt%, 3.2 wt%, 3.6 wt%or 4 wt%, preferably from 0.5 to 2.5 wt%.

Alkoxysilanes

The coating compositions herein can also comprise alkoxysilanes to facilitate dispersion of the ingredients for better leveling and application of the coating. The alkoxysilanes refer to an organosilicon compound containing at least one alkoxy group directly attached to a silicon atom and at least one non-hydrolyzable group directly attached the silicon atom, wherein the alkoxy group is preferably a C₁-C₄ alkoxy group such as methoxy, ethoxy, n-propoxy, isopropoxy and butoxy, and particularly preferably methoxy and ethoxy, and examples of non-hydrolyzable groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, preferably alkyl groups having 6 or more carbon atoms; alkenyl, especially C₂-C₄ alkenyl, such as vinyl, 1-propenyl, 2-propenyl and butenyl; alkynyl, especially C₂-C₄ alkynyl such as ethynyl and propynyl; and aryl, especially C₆-C₁₀ aryl such as phenyl and naphthyl, but are not limited thereto.

Suitable alkoxysilanes herein can be exemplified by methyltrimethoxysilane, dimethyldimethoxysilane, propyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane , n-hexyltrimethoxysilane, n-octyltrimethoxysilane, trimethoxy (2, 4, 4-trimethylpentyl) silane, dodecyltrimethoxysilane, cetyltrimethoxy silane, phenyltrimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, vinyltrimethoxysilane, methylvinyl dimethoxysilane, vinyltris (2-methoxyethoxy) silane, and the homologues of the above-mentioned alkoxysilane with an ethoxy group or an isopropoxy group instead of the methoxy group, but are not limited thereto. The alkoxysilanes herein are preferably those having an alkyl or aryl group with 6 or more carbon atoms to improve the alkali resistance and durability of the coating compositions.

The amount of the alkoxysilane used herein can be less than 10 wt%based on the total weight of the coating composition, suitably from 2 to 10 wt%, and particularly from 3 to 8 wt%.

Catalysts

The catalyst herein can be a variety of condensation catalysts conventionally used in the art. Examples of suitable condensation catalysts include organotin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, dibutyltin dioctanoate, dibutyltin acetylacetonate, dioctyltin oxide, dibutyltin oxide, dimethyltin oxide, and diacetylacetone dibutyltin; organobismuth compounds or bismuth complexes such as bismuth 2-ethylhexanoate, and bismuth tartrate; alkali metal salts such as ethylhexanoic acid zinc salt and zinc acetylacetonate; and titanate such as tetrabutyl titanate, tetrapropyl titanate, tetraisopropyl titanate, and tetraacetylpyruvate titanate; but are not limited thereto.

The total amount of the catalyst used herein is suitably from 0.1 to 2 wt%based on the total weight of the coating composition, preferably from 0.2 to 1.2 wt%, for example from 0.2 to 0.8 wt%, or from 0.4 to 1 wt%.

When the coating composition herein is a one-component system, in order to facilitate the application and produce homogeneous coating films, the dynamic viscosity of the system at 25℃is preferably not more than 1,000 mPa·s, for example, not more than 900 mPa·s, not more than 800 mPa·s, not more than 700 mPa·s, not more than 600 mPa·s, not more than 500 mPa·s, not more than 400 mPa·s, not more than 300 mPa·s, not more than 200 mPa·s, and even not more than 100 mPa·s.

When the coating composition herein is a two-component system, in order to improve the compatibility of the two components for easier mixing and curing of the two components and to produce homogeneous coating films having a proper hardness, the dynamic viscosity difference between the two components at 25℃ is preferably not more than 500 mPa·s, for example, not more than 400 mPa·s, not more than 300 mPa·s, not more than 200 mPa·s, not more than 100 mPa·s, and even not more than 50 mPa·s.

The coating composition herein preferably does not comprise an organic solvent so as to avoid environmental pollution and health impact on the painters or consumers caused by the evaporation of the organic solvent. The expression “does not comprise an organic solvent” herein means that the coating composition contains substantially no organic solvents, and, except for the extremely small amount of organic solvent residues which are inevitably left in the ingredients, the amount of organic solvents is less than 1 wt%, even less than 0.5 wt%, or further even less than 0.2 wt%based on the total weight of the coating composition.

Other optional ingredients

The components of the one-component coating composition or the two-component coating composition herein can also independently comprise other ingredients, for example, any one, or a combination, of pigments and fillers, plasticizers, rheological additives, inorganic thickeners and stabilizers,

wherein the pigments and fillers can be the same conventionally used in the art, for example, clay, calcined clay, kaolin, diatomaceous earth, chalk, calcium carbonate, mica, silica, talc, barium sulfate powder, precipitated calcium carbonate, fumed silica, titanium dioxide, or a combination thereof, but are not limited thereto, and such pigments and fillers can be used in an amount of less than 30 wt%, for example, less than 20 wt%, or less than 10 wt%, based on the total weight of the coating composition;

wherein the plasticizers can be the same conventionally used in the art, for example, phthalates such as dioctyl phthalate, diisooctyl phthalate and diundecyl phthalate, adipates such as dioctyl adipate, benzoate, glycol ester, phosphate, sulfonate and polyesters, polyethers such as polyethylene glycol and polypropylene glycol, polystyrene, polybutadiene, polyisobutylene or paraffinic hydrocarbons, but are not limited thereto, and such plasticizers can be used in an amount of less than 20 wt%, for example, less than 10 wt%, or less than 5 wt%, based on the total weight of the coating composition;

wherein the rheological additives can be the same conventionally used in the art, for example, hydrophilic fumed silica, hydrophobic fumed silica, precipitated silica, polyamide wax, hydrogenated castor oils, stearate or precipitated calcium carbonate, but are not limited thereto, and such rheological additives can be used in an amount of less than 3 wt%, for example, less than 2 wt%, based on the total weight of the coating composition;

wherein the inorganic thickeners can be the same conventionally used in the art, such as fumed silica, aluminosilicate or clay minerals, but are not limited thereto, and such inorganic thickeners can be used in an amount of less than 5 wt%, for example, less than 3 wt%, based on the total weight of the coating composition; and

wherein the stabilizers can be the same conventionally used in the art, including antioxidants and light stabilizers such as hindered phenols, thioethers or benzotriazole derivatives, and such stabilizers can be used in an amount of less than 3 wt%, for example, less than 2 wt%, based on the total weight of the coating composition.

In one embodiment herein, a one-component coating composition is prepared, which consists of 38-95 wt%alkoxy-functional silicone resin, 0-6 wt%silane-terminated polyether, 5- 10 wt%hydroxy silicone oil, 0.5-4 wt%aminosilane, 0-4 wt%epoxy silane, 0-10 wt%alkoxysilane and 0.1-2 wt%catalyst.

In another embodiment herein, a one-component coating composition is prepared, which consists of 50-90 wt%alkoxy-functional silicone resin, 1-5 wt%silane-terminated polyether, 5-10 wt%hydroxy silicone oil, 0.5-4 wt%aminosilane, 0.5-4 wt%epoxy silane, 2-10 wt%alkoxysilane and 0.1-2 wt%catalyst.

In yet another embodiment, a one-component coating composition is prepared, which consists of 38-95 wt%alkoxy-functional silicone resin, 0-25 wt%silane-terminated polyether, 0-4 wt%epoxy silane, 0-10 wt%alkoxysilane, 5-15 wt%hydroxy silicone oil, 0.5-4 wt%aminosilane and 0.1-2 wt%catalyst, wherein the alkoxy-functional silicone resin, silane-terminated polyether, epoxy silane and alkoxysilane are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) .

In still another embodiment, a one-component coating composition is prepared, which consists of 50-90 wt%alkoxy-functional silicone resin, 2-25 wt%silane-terminated polyether, 0.5-4 wt%epoxy silane, 2-10 wt%alkoxysilane, 5-15 wt%hydroxy silicone oil, 0.5-4 wt%aminosilane and 0.1-2 wt%catalyst, wherein the alkoxy-functional silicone resin, silane-terminated polyether, epoxy silane and alkoxysilane are included in the same component (A) , and the hydroxy silicone oil is included in the other component (B) .

The coating composition herein can be easily prepared just by mixing each ingredient according to the one-component system or the two-component system, where there are no special requirements on the operation as long as the ingredients can be mixed well.

The second aspect of the present invention provides use of the coating composition according to the first aspect as an anti-graffiti coating.

The silicone-based coating composition herein can be used directly as an anti-graffiti coating without concerns whether the silicones are compatible with the coating system, can be quickly mixed into the coating system, or have any negative impact on other properties of the coatings, as is the case with silicone-modified anti-graffiti coatings.

When used in form of a one-component system, the coating composition herein can be directly applied to a substrate within 2 hours, suitably within 1.5 hours (e.g. within 1 hour) , after opening of the package, and then left to cure. For the two-component system, the two components are separately stored until they are mixed for use, as is the case with conventional two-component coatings. When the two-component coating composition is used, the two components are mixed in a specific ratio, and afterwards the resulting mixture is applied to a substrate within 2 hours, suitably within 1.5 hours (e.g, within 1 hour) , and then left to cure. The composition or mixture can be applied to the substrate for 1 to 4 times, where, after each application, a drying and/or crosslinking process applies. For the first application, the composition or mixture can be applied in a more dilute form than on its second or further application. Means of the application includes, but is not limited to, spraying, brushing, rolling, knife-coating, rubbing and spin-coating, as long as a substantially continuous film can be formed on the substrate, and spraying is preferred. The curing is carried out generally at room temperature or by means of an additional thermal and/or photochemical treatment, preferably at room temperature. The curing time is usually more than 1 hour, for example, 1-2 hours, 2-4 hours, 4-6 hours, 6-8 hours, 8-12 hours or 12-24 hours.

The anti-graffiti coating herein can be applied to a variety of different substrates such as concretes, cement mortars, concrete sheets, gypsum boards, calcium silicate boards, natural stones and metal substrates, but are not limited thereto, as long as the substrate is solid enough to be a film-forming carrier without any visible stains on the surface. The anti-graffiti coating herein can also be applied to coating surfaces, for example the surface of dried aqueous acrylic primers.

Beneficial effects achieved by the invention are as follows.

1. The coating composition herein demonstrates excellent graffiti resistance through the interaction of an alkoxy-functional silicone resin, a hydroxy silicone oil and an aminosilane. Graffiti on the resulting coating film made with markers and oily pens, which is more corrosive than spray paint, can be wiped off with paper towels/dry cloths without using any solvent (including water) . And the surface of the film is free of any visible graffiti trace even repeating graffiti-removal operation for over 50 times.

2. The coating composition herein demonstrates excellent anti-stick property through the interaction of an alkoxy-functional silicone resin, a hydroxy silicone oil and an aminosilane. Adhesive tapes adhered to the resulting coating film are easily peeled off and no flaking, significant loss of gloss and glue residues are visually inspected on the coating film even after more than 50 sticking-peeling cycles within the same area on the film.

3. The coating composition herein can be solvent free and can provide a proper hardness and adhesion for the coating film without addition of other additives such as pigments and fillers, plasticizers, rheological additives, thickeners, stabilizers, etc..

4. The silicone-based coating composition herein can be used directly as an anti-graffiti coating without concerns whether the silicones are compatible with the coating system, can be quickly mixed into the coating system, or have any negative impact on other properties of the coatings, as is the case with silicone-modified anti-graffiti coatings.

Detailed Description of the Preferred Embodiments

The invention is further illustrated by the following examples, but is not limited to the scope thereof. Any experimental methods with no conditions specified in the following examples are selected according to the conventional methods and conditions, or product specifications.

The anti-graffiti coatings herein are evaluated by the following methods.

1. Evaluation of Graffiti Resistance

The graffiti resistance is evaluated by the level of removability of graffiti with reference to the People’s Republic of China Construction Industry Standard JG/T304-2011.

The level of removability of graffiti is evaluated as follows:

2. Evaluation of Anti-stick Property

The anti-stick property (180° peeling strength) and resistance to repeated sticking tests are evaluated with reference to the People’s Republic of China Construction Industry Standard JG/T304-2011.

3. Evaluation of Other Technical Indexes of Coating

Other technical indexes, including coating appearance, tack-free time, pencil hardness and adhesion, are measured in accordance with the methods and procedures in the People′s Republic of China Construction Industry Standard JG/T304-2011.

Information on ingredients referred to in the following Examples and Comparative Examples:

STP-E10, (isocyanatomethyl) dimethoxymethylsilane-terminated polypropylene glycol having a dynamic viscosity of about 10 Pa·s at 25℃, supplied by Wacker Chemicals.

Silicone resin 1: a methoxy-terminated ^methylD^methylphenylT resin having a number average molecular weight (Mn) of about 700-800 g/mol, supplied by Wacker Chemicals.

Silicone resin 2: a methoxy-terminated ^methylphenylT resin having a kinematic viscosity of about 280-320 mm²/s as measured at 25 ℃ according to DIN 51562, supplied by Wacker Chemicals.

Silicone resin 3: a methoxy-terminated ^{methyl-2, 4, 4-trimethylpentyl}T resin having a number average molecular weight (Mn) of about 700-800 g/mol, supplied by Wacker Chemicals.

Silicone resin 4: a ethoxy-terminated ^methylT resin having a number average molecular weight (Mn) of about 600-700g/mol, supplied by Wacker Chemicals.

GF 95, N- (2-Aminoethyl) -3-aminopropylmethyldimethoxysilane, supplied by Wacker Chemicals.

GF 80, 3- (2, 3-Epoxypropoxy) propyltrimethoxysilane, supplied by Wacker Chemicals;

FINISH WS 62 M, a hydroxyl-terminated polydimethylsiloxane having a dynamic viscosity of about 50-110 mPa·s, as measured at 25 ℃ according to DIN 51562, and a hydroxyl content of 1.6-2.2 wt%, supplied by Wacker Chemicals.

604, a hydroxyl-functional silicone resin, having a hydroxyl content of 3.5-7.0 wt%, supplied by Wacker Chemicals.

Note: The above silicone resin is named after the monomer structure (M) _a (D) _b (T) _c (Q) _d, and the superscripts before D and T indicate the groups contained in the monomer structure.

Examples 1-5 and Comparative Examples 1-4

The ingredients of the coating compositions in each of the Examples and Comparative Examples are shown in Table 1 below.

In Table 1, wt%is based on the total weight of the coating composition.

Table 1 Ingredients of the Examples and Comparative Examples

According to the above Table, the ingredients of component A and component B were mixed respectively to obtain coating compositions. In Examples 1-4 and Comparative Examples 2-4, the dynamic viscosity difference between component A and component B at 25℃ was not more than 500 mPa·s.

The coating compositions of the above Examples and Comparative Examples were only different in the ingredients, and were applied to the substrates to cure into a film by the same method, specifically comprising the steps of:

(1) mixing: component A and component B were mixed well to obtain a mixture;

(2) curing: the resulting mixture was applied to a fiber cement plate within 1 hour and cured at room temperature for 6 hours.

Performance of the coatings prepared in each of the examples and comparative examples are shown in Table 2 below.

Table 2 Performance of Each of the Examples and Comparative Examples

As can be seen from the above Table, the coating compositions of Examples 1-5 had excellent anti-graffiti property and resistance to repeated sticking. The graffiti made with ink, oily pens and spray paints on the coating films could be removed with a paper towel or dry cloth. And no flaking, significant loss of gloss and glue residues are visually inspected on the coating films even after more than 50 sticking-peeling cycles within the same area on the film by a tape. Furthermore the coating films had good hardness and exhibited standard-compliant adhesion to the fiber cement boards.

Because of the absence of hydroxy silicone oils, the coating composition of Comparative Example 1 was less resistant to graffiti as the graffiti made with inks, oily pens and spray paints on the coating film had to be removed using a citrus-based cleaning agent, and its resistance to repeated sticking was not satisfactory. The coating composition of Comparative Example 2 comprised a silane-terminated polyether, an alkoxy-functional silicone resin, a hydroxy silicone oil and an aminosilane, but was not cured in 48 hours due to the lack of a catalyst. The coating composition of Comparative Example 3, based on Comparative Example 2, where the silane-terminated polyether was excluded, was not cured in 48 hours either. The formulation of the coating composition of Comparative Example 4 was substantially the same as that of Example 4 except that the hydroxy silicone oil in Example 4 was replaced by a hydroxy silicone resin, and since the silicone resin was a solid, it was difficult to mix with other ingredients and had to be dissolved in a solvent in advance. Therefore, toluene was added in component B. The coating composition of Comparative Example 4 had poor resistance to graffiti as the graffiti made with ink, oily pens and spray paints on the coating film had to be removed using anhydrous alcohol, and the anti-stick property was not satisfactory.

Since the coating compositions of the Examples and Comparative Examples were applied to the fiber cement board, epoxy silane was added to the formulation to increase the adhesion between the coating film and the fiber cement board. If the coating compositions were applied to an aqueous acrylic primer, addition of epoxy silane to the formulation would be optional. In addition, the coating compositions of Examples 1-3 and 5 comprised silane-modified polyethers, so they had excellent flexibility and were suitable for applications on various substrates including metals. On the contrary, the coating composition of Example 4 did not comprise silane-modified polyethers, so it had poor flexibility and high brittleness, which limited its suitability for substrates. For example, it is not applicable to metal substrates.

Claims

A coating composition, which is one-component or two-component, comprising:

an alkoxy-functional silicone resin,

a hydroxy silicone oil having the following general formula with a dynamic viscosity of not more than 1, 000 mPa·s at 25℃:

where R and R’ are each independently an alkyl or aryl group;

X is a hydroxy, hydrogen, halogen, alkyl, aryl or alkenyl group;

n is a non-zero integer, and

m is an integer including zero;

an aminosilane, and

a catalyst;

wherein the alkoxy-functional silicone resin and the hydroxy silicone oil are in different components in a two-component coating composition.
The coating composition according to claim 1, characterized in that in formula II, X is a hydroxyl group;

and/or, n+m is an integer between 5 and 99, inclusive.
The coating composition according to claim 1 or claim 2, characterized in that the hydroxy silicone oil has a dynamic viscosity of not more than 300 mPa·s at 25℃ and a hydroxyl content of from 1 to 5 wt%based on the total weight of the hydroxy silicone oil.
The coating composition according to any one of claims 1 to 3, characterized in that the amount of the alkoxy-functional silicone resin is from 38 to 95 wt%,

and/or, the amount of the hydroxy silicone oil is from 5 to 15 wt%,

and/or, the amount of the aminosilane is from 0.5 to 4 wt%,

and/or, the amount of the catalyst is from 0.1 to 2 wt%,

based on the total weight of the coating composition.
The coating composition according to any one of claims 1 to 4, further comprising a silane-terminated polyether having the following general formula:

where R₂ and R₃ are each independently Hor an alkyl group;

R^a and R^b are each independently a hydrocarbon group having from 1 to 18 carbon atoms or an ω-oxaalkyl-alkyl group having a total of from 2 to 20 carbon atoms;

X is -CH₂-, -CH₂NHC (=O) -, - (CH₂) ₃-, or - (CH₂) ₃NHC (=O) -, wherein X is bonded via Si-C;

n is an integer between 1 and 300, inclusive; and

m is 2 or 3.
The coating composition according to claim 5, characterized in that the amount of the silane-terminated polyether is from 2 to 25 wt%based on the total weight of the coating composition.
The coating composition according to any one of claims 1 to 6, characterized in that the alkoxy-functional silicone resin is an alkoxy-terminated DT resin and/or T resin.
The coating composition according to any one of claims 1 to 7, characterized in that the surface of the alkoxy-functional silicone resin contains an alkyl or aryl substituent having 6 or more carbon atoms.
The coating composition according to any one of claims 1 to 8, characterized in that in a two-component coating composition, the dynamic viscosity difference between the two components at 25℃ is not more than 500 mPa·s.
The coating composition according to any one of claims 1 to 9, containing less than 1 wt%of organic solvents based on the total weight of the coating composition.
The coating composition according to any one of claims 1 to 10, characterized in that in a one-component coating composition, the component contains less than 0.1 wt%of water based on the total weight of the coating composition, or

in a two-component coating composition, the component comprising the hydroxy silicone oil contains less than 2 wt%of water and the component comprising the alkoxy-functional silicone resin contains less than 0.1 wt%of water based on the total weight of the coating composition.
The coating composition according to any one of claims 1 to 11, further comprising 0.5-4 wt%epoxy silane based on the total weight of the coating composition.
The coating composition according to any one of claims 1 to 12, further comprising 2-10 wt%alkoxysilane based on the total weight of the coating composition.
The coating composition according to claim 13, characterized in that the surface of the alkoxysilane contains an alkyl or aryl substituent having 6 or more carbon atoms.
Use of the coating composition according to any one of claims 1 to 14 as an anti-graffiti coating composition.