Process

Abstract

The invention provides a method for producing a multi-layer coating system comprising at least two coating layers, wherein: i) a first coating layer is applied by spray coating to a wet film thickness of 50-300 pm; and ii) applying the second coating by spray coating to a wet film thickness of 50-300 pm; wherein a second coating is applied directly on top of the first coating 5 minutes to 6 hours after the first coating is applied; and wherein the first coating layer and the second coating layer comprise a polysiloxane-based coating composition comprising a) a polysiloxane-based binder system; and b) a curing agent or a crosslinking agent.

Description

Technical Field

[0001] The present invention relates to a method for preparing a multilayer coating system (multilayer coatingsystem). In particular, the present invention provides a method in which at least two coatings comprising a polysiloxane-based coating composition (polysiloxane-based coating composition, polysiloxane-based coating composition) are applied, and in which the second coating is applied at a specific time interval after the first coating. Background Art

[0002] Fouling release coatings are used on marine vessels to prevent marine biofouling. The principle of these works is that fouling release surfaces have a very low coefficient of friction and thus it is very difficult for marine organisms to adhere to the surface, especially when the ship is sailing and thus the action of the sea can wash away marine organisms from the hull.

[0003] Therefore, fouling release coatings are characterized by low surface tension and low elastic modulus, so that biofouling does not adhere to the surface or biofouling is easily washed away by the friction of water with the surface.

[0004] Such coatings typically contain a polysiloxane binder having reactive (curable) groups such as hydroxyl or silyl units. The polysiloxane binder can hydrolyze and condense in the presence of moisture and a catalyst.

[0005] Typically, fouling release coating systems are applied as a system having two primer coats, one tiecoat, and one topcoat. The paint (coating) is sprayed in a small overlapping pattern (usually 10 - 15 cm). US6048580 describes applying a tiecoat and a topcoat to a substrate. EP3974482 describes a fouling release coating based on a combination of a polysiloxane binder with a biocide and a catalyst to promote curing. This coating is applied in one layer.

[0006] However, recently two topcoats have been used to apply biocidal fouling release coatings, for example as described in WO 2011 / 076856. The reason for applying two coatings is to better control the film thickness (i.e., obtain a uniform film thickness) and be able to apply a thicker topcoat to ensure that there is sufficient biocide in the topcoat to last for more than three years. An additional benefit is that the paint does not require the same sag resistance when applied as two coatings compared to when applied as one thick coating conventionally.

[0007] However, applying two topcoats does have its risks and drawbacks. The overcoating window of polysiloxane-based fouling release coatings is narrow, and atmospheric conditions can interfere with the application of the coatings, resulting in the second coat being applied outside the overcoating window, with poor adhesion as a result, or even preventing the second coat from being applied. Applying and curing two coats also takes longer than a single coat of the same total thickness.

[0008] Currently, suppliers of topcoat paints designed to be applied as two coats specify a minimum interval of at least 8 hours between the two applications. Generally, when applying a multi-coat system, it is common practice to allow one coat to dry / cure before applying the next. The challenge with using polysiloxane-based coatings is that if the first coat has fully dried / cured, the adhesion of the next coat will be poor, even if the next coat is also a polysiloxane-based coating. This is at least in part a result of the fact that polysiloxane topcoats are designed to prevent objects (such as marine organisms) from adhering to the surface. Once cured, it has a surface that prevents other materials from adhering.

[0009] In the present invention, the inventors have found that the second coat can be applied shortly after the first coat has been applied. This method will save time in the dock and reduce the risk of weather complications and poor adhesion. The present invention allows two topcoats to be applied in one go, without waiting for the paint to cure before applying the second coat. The second coat can be applied 5 minutes after the first coat has been applied, allowing some of the solvent to evaporate and the curing to begin. Therefore, it should be understood that in the method of the present invention, the first coat is not fully cured before the second coat is applied.

[0010] This application reduces the risk of rain interfering with the application of the two coats. Applying two coats in one go also reduces the time required to apply two fouling release topcoats when no waiting for curing is needed. This will reduce the time required in the dock.

[0011] The method of the present invention also provides potential advantages in that the film thickness is more uniform and the risk of sagging in the overlapping areas where the film thickness is higher than the specified thickness is reduced. In addition, it allows for a higher film thickness with a lower anti-sag paint. SUMMARY OF THE INVENTION

[0012] In one aspect, the present invention provides a method for preparing a multi-coat system comprising at least two coats, wherein

[0013] i) applying a first coat by spray application to a wet film thickness of 50 - 300 μm; and

[0014] ii) applying a second coat by spray application to a wet film thickness of 50 - 300 μm;

[0015] Wherein, 5 minutes to 6 hours after applying the first coating, the second coating is directly applied on top of the first coating; and

[0016] Wherein the first coating and the second coating independently comprise a polysiloxane coating composition, and the polysiloxane coating composition comprises:

[0017] a) A polysiloxane binder system

[0018] b) A curing agent or crosslinking agent.

[0019] Definitions

[0020] As used herein, the term "fouling release composition" or "fouling release coating composition" refers to a composition that provides a fouling release surface on which marine organisms have difficulty permanently adhering when applied to a surface. The term "fouling release coating system" should be understood to refer to a coating system with a similar definition.

[0021] As used herein, the term "top-coat" refers to a polysiloxane coating composition. Preferably, the polysiloxane coating composition is a fouling release coating composition.

[0022] As used herein, the term "binder system" refers to the film-forming component of the composition. The polysiloxane binder of the composition is the main binder in the binder system, i.e., it accounts for at least 50 wt%, such as at least 75 wt% of the binder system. As used herein, the term "binder system" does not cover additive oils. Additive oils are not regarded as film-forming components herein.

[0023] In one embodiment, the binder system consists of one or more polysiloxane binders.

[0024] As used herein, the term "paint" refers to a composition comprising a coating composition as described herein and an optional solvent, and the composition is ready-to-use, for example, for spraying. Thus, the coating composition itself can be a paint, or the coating composition can be a concentrate, to which a solvent is added to prepare a paint.

[0025] As used herein, the term "polysiloxane" refers to a polymer containing siloxane, i.e., -Si-O- repeating units.

[0026] As used herein, the term "polysiloxane adhesive" refers to an adhesive that contains, based on the total weight of the polymer, at least 50 wt%, preferably at least 60 wt% and more preferably at least 70 wt% of repeating units containing the motif -Si-O-. Based on the total weight of the polymer, the polysiloxane adhesive can contain up to 99.99 wt% of repeating units containing the motif -Si-O-. The repeating units -Si-O- can be linked in a single sequence (order) or alternatively can be interrupted by non-siloxane moieties, such as organic-based parts.

[0027] As used herein, the term "non-degradable polysiloxane adhesive" refers to a polysiloxane adhesive that does not undergo hydrolysis degradation or erosion in seawater.

[0028] As used herein, the term "alkyl" refers to a saturated, straight-chain, branched-chain, or cyclic group.

[0029] As used herein, the term "cycloalkyl" refers to a cyclic alkyl group.

[0030] As used herein, the term "alkylene" refers to a divalent alkyl group.

[0031] As used herein, the term "alkenyl" refers to an unsaturated, straight-chain, branched-chain, or cyclic group.

[0032] As used herein, the term "aryl" refers to a group containing at least one aromatic ring. The term aryl includes fused ring systems in which one or more aromatic rings are fused to a cycloalkyl ring. An example of an aryl group is phenyl, i.e., C6H5.

[0033] As used herein, the term "substituted" refers to a group in which one or more, such as up to 6, more specifically 1, 2, 3, 4, 5, or 6 hydrogen atoms in the group are each independently replaced by the corresponding number of said substituents.

[0034] As used herein, the term "arylalkyl" group refers to a group in which the group is bonded to Si through an alkyl moiety.

[0035] As used herein, the term "polyether" refers to a compound containing two or more -O- linkages (bondings) interrupted by alkylene units.

[0036] As used herein, the terms "poly(alkylene oxide)" (poly(alkylene oxide), poly(oxyalkylene), poly(alkylene glycol)) and "poly(oxyalkylene)" (poly(oxyalkylene), poly(alkylene glycol)) refer to compounds containing -alkylene-O- repeating units. Generally, the alkylene group is an ethylene group or a propylene group.

[0037] As used herein, unless otherwise specified, the term wt.% is based on the dry weight of the coating composition.

[0038] As used herein, the term "PDI" or polydispersity index refers to the ratio of Mw / Mn, where Mw refers to the weight-average molecular weight and Mn refers to the number-average molecular weight. PDI may sometimes be alternatively referred to as D (dispersity).

[0039] As used herein, the term "volatile organic compound (VOC)" refers to a compound having a boiling point of 250 °C or lower.

[0040] As used herein, an "antifouling agent" refers to a bioactive compound or a mixture of bioactive compounds that prevents marine organisms from settling on a surface, and / or prevents marine organisms from growing on a surface and / or promotes the removal of marine organisms from a surface. Detailed Description

[0041] The present invention relates to a method for preparing a coating system comprising at least two coatings, wherein a second coating is directly applied on top of a first coating 5 minutes to 6 hours after the application of the first coating, and wherein the first coating and the second coating independently comprise a polysiloxane-based coating composition, the polysiloxane-based coating composition comprising:

[0042] a) a polysiloxane-based binder system

[0043] b) a curing agent or a crosslinking agent.

[0044] Polysiloxane-based Binder System

[0045] The binder system in the coating composition comprises at least one curable polysiloxane-based binder.

[0046] Any polysiloxane-based binder is preferably a non-degradable curable polysiloxane-based binder.

[0047] Relative to the total weight of the binder, any polysiloxane binder present in the coating composition of the present invention comprises at least 50 wt% of a polysiloxane moiety, preferably greater than 60 wt% of a polysiloxane moiety and still more preferably greater than 70 wt% of a polysiloxane moiety, such as 99.99 wt% of a polysiloxane moiety or more. In the polysiloxane binder, typical ranges include 50 - 100 wt% of a polysiloxane moiety, 60 - 99.999 wt% of a polysiloxane moiety, or 70 - 99.99 wt% of a polysiloxane moiety.

[0048] Based on the total weight of the polysiloxane binder, the polysiloxane moiety is defined as repeating units containing the motif -Si-O-. The wt% of the polysiloxane moiety can be determined based on the stoichiometric weight ratio of the starting materials in the polysiloxane synthesis. Alternatively, the polysiloxane content can be determined using analytical techniques such as IR or NMR.

[0049] Typically, the wt.% of the polysiloxane moiety is calculated based on the molar ratio of the reactive starting materials in the polysiloxane synthesis. If there is a molar excess of monomers present in the reaction mixture, such molar excess is not counted. Only those monomers that can react based on the stoichiometry of the reaction are counted.

[0050] Information regarding the wt.% polysiloxane moiety in commercially available polysiloxane binders is readily available from suppliers.

[0051] It should be understood that the polysiloxane binder can consist of a single repeating sequence of siloxane units or be interrupted by non-siloxane moieties such as organic moieties. Preferably, the polysiloxane binder contains only Si-O repeating units.

[0052] The organic moiety can include, for example, alkylene, arylene, poly(alkylene oxide), amide, thioether, or combinations thereof, and preferably the organic moiety can include, for example, alkylene, arylene, poly(alkylene oxide), amide, or combinations thereof.

[0053] Curable means that the polysiloxane binder contains functional groups that enable a crosslinking reaction to occur between polysiloxane binder molecules or via a crosslinking agent.

[0054] Any polysiloxane - based binder is preferably an organopolysiloxane having terminal and / or side - chain curing - reactive functional groups. Preferably, there are at least two curing - reactive functional groups per molecule. Examples of curing - reactive functional groups are silanol, alkoxy, acetoxy, enoxy, ketoxime, amineoxy, amine, epoxy, vinyl, and / or isocyanate. The preferred polysiloxane - based binder contains a curing - reactive functional group selected from silanol, alkoxy, or acetoxy. The curing reaction is usually a condensation curing reaction. The polysiloxane - based binder optionally contains more than one type of curing - reactive group and can be cured, for example, by both condensation curing and amine / epoxy curing.

[0055] The polysiloxane - based binder can consist of only one type of polysiloxane or can be a mixture of different polysiloxanes, as long as the requirements of the present invention are met.

[0056] The polysiloxane - based binder can be a linear or branched polysiloxane - based binder. Branched means that the polysiloxane chain is branched. The branched polysiloxane - based binder can also contain a cage - like polysiloxane structure, also known as a polysiloxane resin.

[0057] In a preferred embodiment, the polysiloxane - based binder is linear.

[0058] The preferred polysiloxane - based binder present in the soil - release coating composition of the present invention is represented by the following formula (D1):

[0059]

[0060] Where

[0061] Each R 1 is independently selected from hydroxyl, C 1-6 - alkoxy, O - Si(R 5 ) 3-z (R 6 ) z , C 1-6 - hydroxyl, a group containing C 1-6 - epoxy (C 1-6 - epoxy containing group), C 1-6 amino, C 1-10 alkyl, C 6-10 aryl, or C 7-10 alkaryl. Preferably, each R 1 is independently selected from hydroxyl, C 1-6 - alkoxy, O - Si(R 5 ) 3-z (R 6 ) z .

[0062] Each R 2 is independently selected from C 1-10 alkyl, C 6-10 aryl, C 7-10 alkylaryl or C 1-6 alkyl substituted by poly(alkylene oxide) (poly(alkylene oxide), poly(alkylene oxide), poly(alkylene oxide)) and / or the groups described for R 1 ;

[0063] Each R 3 and R 4 are independently selected from C 1-10 alkyl, C 6-10 aryl, C 7-10 alkylaryl or C 1-6 alkyl substituted by poly(alkylene oxide);

[0064] Each R 5 is independently a hydrolyzable group such as C 1-6 alkoxy, acetoxy, enoxy group or ketoxy group;

[0065] Each R 6 is independently selected from C 1-6 alkyl;

[0066] z is an integer from 0 or 1 - 2;

[0067] x is an integer of at least 2;

[0068] y is an integer of at least 2.

[0069] Preferably, R 1 is selected from hydroxy and O - Si(R 5 ) 3-z (R 6 ) z , where R 5 is C1 - C6 alkoxy, R 6 is C 1-6 alkyl and z is an integer from 0 or 1 - 2. More preferably, R 1 is selected from hydroxy and O - Si(R 5 ) 3-z (R 6 ) z , where R 5 is C1 - C3 alkoxy, R 6 is C 1-3 alkyl and z is an integer from 0 or 1 - 2. Even more preferably, R 1 is hydroxy.

[0070] Preferably, R 2 is C 1-10 alkyl. More preferably, R 2 is C 1-4 alkyl, even more preferably C 1-2 alkyl, and still more preferably methyl. Preferably, each R 2 is the same.

[0071] Preferably, R 3 is C 1-10 alkyl. More preferably, R 3 is C 1-4 alkyl, even more preferably C 1-2 alkyl, and still more preferably methyl. Preferably, each R 3 is the same.

[0072] Preferably, R 4 is C 1-10 alkyl. More preferably, R 4 is C 1-4 alkyl, even more preferably C 1-2 alkyl, and still more preferably methyl. Preferably, each R 4 is the same.

[0073] Even more preferably, R 1 is hydroxyl and R 2 , R 3 and R 4 are each methyl.

[0074] Another preferred polysiloxane binder present in the soil release coating composition of the present invention is represented by the following formula (D2):

[0075]

[0076] wherein

[0077] each R 1 is independently selected from hydroxyl, C 1-6 -alkoxy or O-Si(R 5 ) 3-z (R 6 ) z ,

[0078] each R 2 to R 4 is methyl;

[0079] each R 5 is independently a hydrolysable group such as C 1-6 alkoxy, acetoxy, enoxy or ketoxy;

[0080] each R 6independently selected from C 1-6 alkyl;

[0081] z is an integer of 0 or 1 - 2;

[0082] x is an integer of at least 2;

[0083] y is an integer of at least 2.

[0084] Another preferred polysiloxane binder present in the soil - release coating composition of the present invention is represented by the following formula (D3):

[0085]

[0086] wherein R 1 、R 2 、R 3 、R 4 and x as well as y are as defined for (D1), R x is C 2-3 alkyl, each L1 is from 0 to 50, each L2 is from 0 to 50, provided that L1 + L2 is from 2 to 50, preferably from 4 to 40, more preferably from 4 - 20, most preferably from 4 - 10 and L3 is from 1 - 200, preferably from 2 - 100, most preferably from 5 - 50. The polysiloxane moiety must account for at least 50 wt% of the molecule.

[0087] Preferably, the polysiloxane binder of the present invention is represented by formula (D1).

[0088] Preferably, any polysiloxane binder of the present invention is polydimethylsiloxane.

[0089] Those skilled in the art will realize that the polysiloxane binder may contain small amounts of impurities as residues from polysiloxane synthesis, such as cyclic siloxanes, such as D4, D5 and D6 cyclic siloxanes, where the names (D4, D5 or D6) refer to the number of repeating Si - O units in the cyclic polysiloxane (i.e., there are 4, 5 or 6 repeating Si - O units respectively in the cyclic polysiloxane). Considering health, safety and environmental aspects, it is preferred to limit the amount of cyclic polysiloxanes present in the coating. In a preferred embodiment, the polysiloxane binder contains less than 5% of cyclic polysiloxanes, preferably less than 2%, more preferably less than 1%. In a particularly preferred embodiment, the polysiloxane binder does not contain cyclic polysiloxanes.

[0090] The weight - average molecular weight of the polysiloxane binder or any combination of polysiloxane binders present in the soil - release coating composition of the present invention is preferably from 400 - 150,000 g / mol, more preferably from 1000 - 120,000 g / mol, and even more preferably from 5000 - 110,000 g / mol.

[0091] Polysiloxane adhesives or combinations of polysiloxane adhesives typically account for at least 35 wt% of the polysiloxane coating composition (dry weight), such as at least 40 wt% of the soil release coating composition (dry weight), especially at least 45 wt%, for example 35 to 75 wt%.

[0092] In one embodiment, the required polysiloxane adhesive system comprises two independent polysiloxane polymers A and B having different molecular weights or viscosities, where polysiloxane polymers A and B can each be as defined herein and as described in WO2022069482 A1 and WO2022069487A1. In one embodiment, the required polysiloxane adhesive system comprises three independent polysiloxane polymers A, B and C, as described in WO2022069487 A1.

[0093] If a combination of polysiloxane adhesive A and polysiloxane adhesive B is present, the preferred molecular weights and viscosities are as follows.

[0094] The weight average molecular weight (Mw) of polysiloxane adhesive A is preferably 50,000 g / mol or lower, such as 3,500 to 50,000, preferably 8,000 to 50,000 g / mol. In a more preferred embodiment, the weight average molecular weight of polysiloxane adhesive A is 10,000 to 48,000, more preferably 15,000 to 45,000, especially 20,000 to 40,000 g / mol.

[0095] In one embodiment, the number average molecular weight (Mn) of polysiloxane adhesive A is less than 25,000 g / mol, such as 1,000 to 24,000 g / mol, preferably 2,000 to 24,000 g / mol. In a more preferred embodiment, the number average molecular weight of polysiloxane adhesive A is 3,000 to 19,500 g / mol, more preferably 4,000 to 19,500 g / mol, especially 5,000 to 19,500 g / mol. The molecular weight (Mn and Mw) values referred to herein correspond to experimentally obtained values, for example measured by GPC relative to polystyrene standards. The method is given in the experimental section below.

[0096] In one embodiment, the weight average Mw of polysiloxane adhesive B is preferably 55,000 or higher, such as 60,000 to 120,000 g / mol, still more preferably 65,000 to 110,000 g / mol.

[0097] The viscosity of polysiloxane adhesive A is preferably 2,800 mPas or lower, such as 400 to 2,800, more preferably 400 to 2,000, especially 500 to 1500 mPas.

[0098] The viscosity of polysiloxane adhesive B is preferably 3,500 mPas or higher, such as 4,000 to 30,000 mPas, still more preferably 5,000 to 25,000 mPas.

[0099] In the case where there are two adhesives, it is preferred that each adhesive accounts for at least 27 wt% of the adhesive system, preferably at least 40 wt% of the adhesive system. It is preferred that the ratio of adhesive A to adhesive B is in the range of 30:70 to 70:30, preferably 40:60 to 60:40, more preferably 45:55 to 55:45.

[0100] Alternatively, each adhesive accounts for at least 20 wt% of the coating composition.

[0101] In the case of using a mixture of adhesives A and B, it is preferred that the PDI of the adhesive mixture is at least 2.5, such as 2.5 to 10, especially 3.0 to 8.0.

[0102] In the case of using a mixture of adhesives A and B in the adhesive system, it is preferred that the viscosity of the adhesive system is 400 to 30,000 mPas, more preferably 1000 to 25,000 mPas, even more preferably 2000 to 15,000 mPas, such as 2500 to 11,000 mPas.

[0103] In the case of using a mixture of adhesives A and B in the adhesive system, it is preferred that the weight average molecular weight of the adhesive system is 25,000 - 100,000 g / mol, more preferably 30,000 - 80,000, even more preferably 40,000 - 80,000 g / mol. In the case of using a mixture of adhesives A and B in the adhesive system and the weight average molecular weight of the adhesive system is greater than 50,000, it is also preferred that the PDI of the adhesive system is at least 2.5.

[0104] Additive oil

[0105] The coating composition of the present invention may contain additive oils. These additive oils do not contain any curing-reactive groups, so the additive oils are intended to be non-reactive in the curing reaction. Depending on the curing mechanism of the adhesive system, the functional groups on the additive oils should be selected such that they do not react in the curing reaction of the polysiloxane adhesive. The added oils are intended to be free in the coating film so that they can migrate to the surface of the coating film and improve the antifouling performance of the coating film.

[0106] Examples of suitable additive oils are hydrophilically modified polysiloxane oils and hydrophobically modified polysiloxane oils. Other additive oils can also be used, such as petroleum oils, polyolefin oils, polyaromatic oils (polyaromatic oils), fluororesins such as polytetrafluoroethylene or fluid fluorinated alkyl- or alkoxy-containing polymers, or lanolin and lanolin derivatives and one or more other sterols and / or one or more sterol derivatives (as disclosed in WO2013024106A1), or poly(oxyalkylene)-modified alcohols such as poly(oxyalkylene)-modified sterols or combinations thereof as disclosed in WO2016004961A1.

[0107] A further additive oil optionally present in the coating composition of the present invention is a fluorinated amphiphilic polymer / oligomer as described in WO2014131695.

[0108] Suitable additive oils can also be based on (meth)acrylate copolymers having polysiloxane side chains and polyether or nitrogen-containing hydrophilic groups, such as those described in WO2019101912 A1 and WO2019101920 A1.

[0109] Preferably, the additive oil is a hydrophilically modified polysiloxane oil and / or a hydrophobically modified polysiloxane oil. The hydrophilically modified polysiloxane oil and the hydrophobically modified polysiloxane oil can be used in combination. Suitable hydrophilically modified polysiloxane oils and hydrophobically modified polysiloxane oils are described in more detail below.

[0110] Hydrophilically modified polysiloxane

[0111] The coating composition of the present invention can additionally contain a hydrophilically modified polysiloxane. It should be understood that this component is different from the polysiloxane binders discussed above.

[0112] It should be understood that the hydrophilically modified polysiloxane does not contain silicone reactive groups (silicone reactive groups), such as Si-OH groups, Si-OR (alkoxy) groups, etc., that are capable of reacting with the binder or crosslinker (if present) at the relevant curing temperatures (0 - 40°C). Therefore, the hydrophilically modified polysiloxane is intended to be non-reactive in the curing reaction, particularly with respect to the binder component. Such a component is not considered part of the binder system.

[0113] The functional groups on the hydrophilically modified polysiloxane should be selected such that they do not react in the curing reaction depending on the curing mechanism.

[0114] Since it contains both hydrophilic and lipophilic groups in the same molecule, hydrophilically modified polysiloxanes are widely used as surfactants and emulsifiers. The hydrophilically modified polysiloxane according to the present invention is a polysiloxane modified with a hydrophilic group so as to be more hydrophilic compared to the corresponding unsubstituted polysiloxane having the same number of polysiloxane units. The hydrophilicity can be obtained by modification with hydrophilic groups such as ethers (e.g., polyalkylene oxide groups such as polyethylene glycol and polypropylene glycol), alcohols (e.g., poly(glycerol)), amides (e.g., pyrrolidone, polyvinylpyrrolidone, (meth)acrylamide), acids (e.g., carboxylic acids, poly(meth)acrylic acid), amines (e.g., polyethyleneamine, (meth)acrylic acid polymers containing amino groups). Generally, hydrophilically modified polysiloxanes are oils.

[0115] In a preferred embodiment, the hydrophilic group is non-ionic.

[0116] 'Non-ionic' as used herein means that the hydrophilically modified polysiloxane does not contain any salt moieties; in particular, it generally does not contain any metal cations.

[0117] The hydrophilicity of non-ionic hydrophilically modified polysiloxanes can be determined according to the HLB (hydrophilic-lipophilic balance) parameter. If the hydrophilically modified polysiloxane of the present invention is non-ionic, then the HLB (hydrophilic-lipophilic balance) is in the range of 0.5 - 12, preferably 0.5 - 10, more preferably 0.5 - 8.0, and most preferably 0.5 - 7.0. In a particular embodiment, the non-ionic hydrophilically modified polysiloxane has an HLB in the range of 3.0 - 6.0.

[0118] In the present context, the HLB is generally determined according to the Griffin model using the equation "wt% of hydrophilic groups" / 5 (Reference: Griffin, W.C. Calculation of HLB values of non-ionic surfactants, J.Soc.Cosmet.Chem. 1954, 5, 249 - 256). The HLB parameter is a well-recognized parameter for non-ionic surfactants and can be readily obtained from the suppliers of commercially available hydrophilically modified polysiloxanes. The higher the HLB value of a surfactant, the stronger its hydrophilicity. The wt% of hydrophilic groups refers to the wt% of the hydrophilic groups in the hydrophilically modified polysiloxane.

[0119] One function of the hydrophilically modified polysiloxane is to facilitate the dissolution and delivery of any biocide to the surface of the coating film. In addition, it is well known that the formation of a hydration layer at the coating-water interface is important for antifouling performance.

[0120] If the hydrophilicity of the hydrophilically modified polysiloxane is too high, e.g., due to a large number of hydrophilic groups in the molecule, this can lead to premature depletion of one or more biocides and the hydrophilically modified polysiloxane due to too high a leaching rate. High hydrophilicity can also lead to poor compatibility with the polysiloxane-based adhesive matrix, especially if a high oil content (greater than 10 wt.%) is used, resulting in poor film uniformity and adhesion.

[0121] Ways to control the leaching rate of the biocide and the hydrophilically modified polysiloxane include the molecular weight, hydrophilicity, and miscibility with the adhesive of the hydrophilically modified polysiloxane. A very low molecular weight hydrophilically modified polysiloxane tends to allow a high leaching rate, while too high a molecular weight may not allow the biocide and the hydrophilically modified polysiloxane to leach at the desired rate.

[0122] Thus, in a preferred embodiment, the number average molecular weight (Mn) of the hydrophilically modified polysiloxane is in the range of 500 - 18,000 g / mol, such as in the range of 1000 - 16,000 g / mol, especially in the range of 2000 - 15,050 g / mol or 4000 - 15,050 g / mol. Further suitable ranges of Mn for the hydrophilically modified polysiloxane include 500 - 15,000 g / mol, 1,000 - 13,000 g / mol, or 3,000 - 10,000 g / mol. The number average molecular weight (Mn) values mentioned herein correspond to experimentally obtained values, e.g., measured by GPC relative to a polystyrene standard. The method is given in the experimental section below.

[0123] In a preferred embodiment, the weight average molecular weight (Mw) of the hydrophilically modified polysiloxane is 1,000 - 50,000 g / mol, preferably in the range of 2,000 - 45,000 g / mol, 3,000 - 42,000 g / mol, 4,000 - 40,000 g / mol, or 5,000 - 40,000 g / mol. Further suitable ranges include 5,000 - 30,000 g / mol, e.g., 5,000 - 25,000 g / mol or 10,000 - 20,000 g / mol. The weight average molecular weight (Mw) values mentioned herein correspond to experimentally obtained values, e.g., measured by GPC relative to a polystyrene standard. The method is given in the experimental section below.

[0124] It is also preferred that the viscosity of the hydrophilically modified polysiloxane is in the range of 20 - 4,000 mPa·s, such as in the range of 30 - 3,000 mPa·s, especially in the range of 50 - 2,500 mPa·s.

[0125] The hydrophilically modified polysiloxane may be included in the coating composition in an amount of 1.0 - 30 wt%, preferably 2.0 - 20 wt%, more preferably 4 - 15 wt% dry weight. In the case where there are two or more different types of hydrophilically modified polysiloxanes, these amounts refer to the sum of the hydrophilically modified polysiloxane components.

[0126] Particularly interesting are those hydrophilically modified polysiloxanes in which the relative weight of the hydrophilic moiety is 5% or more (e.g., 5 - 60%) of the total weight of the hydrophilically modified polysiloxane, such as 6% or more (e.g., 6 - 50%) of the total weight of the hydrophilically modified polysiloxane, especially 10% or more (e.g., 10 - 40%).

[0127] The wt.% of the hydrophilic moiety can be calculated based on the stoichiometric ratio of the starting materials in the synthesis of the hydrophilically modified polysiloxane, or it can be determined using analytical techniques such as IR or NMR.

[0128] If there is a molar excess of reactants, this molar excess is not counted when determining the wt.% of the hydrophilic moiety. Only those monomers that can react based on the stoichiometry of the reaction are counted.

[0129] The hydrophilically modified polysiloxane may contain small amounts of impurities as residues from the polysiloxane synthesis, such as cyclic siloxanes, such as D4, D5, and D6 cyclic siloxanes, where the names (D4, D5, and D6) refer to the number of repeating Si - O units in the cyclic polysiloxane (i.e., there are 4, 5, or 6 repeating Si - O units, respectively, in the cyclic polysiloxane). From a health, safety, and environmental perspective, it is preferred to limit the amount of cyclic polysiloxanes present in the coating composition. In a preferred embodiment, the hydrophilically modified polysiloxane contains less than 5% of cyclic polysiloxanes, preferably less than 2%, more preferably less than 1%. In a particularly preferred embodiment, the hydrophilically modified polysiloxane is free of cyclic polysiloxanes.

[0130] In a preferred embodiment, the hydrophilically modified polysiloxane is a polyether - modified polysiloxane.

[0131] Preferably, the polyether group includes at least 3 repeating units, such as at least 5 repeating units. In many interesting embodiments, the oligomer or polymer includes 5 - 100 repeating units, such as 5 - 50, or 8 - 50, or 8 - 20 repeating units.

[0132] In some preferred embodiments, the polyether group (i.e., the oligomeric or polymeric group) has a number average molecular weight (n) in the range of 100 - 2500 g / mol, such as in the range of 200 - 2000 g / mol, particularly in the range of 300 - 2000 g / mol, or in the range of 400 - 1000 g / mol.

[0133] Particularly interesting are those polyether-modified polysiloxanes in which the relative weight of the polyether portion is 5% or more (e.g., 5 - 60%) of the total weight of the polyether-modified polysiloxane, such as 6% or more (e.g., 6 - 50%) of the total weight of the polyether-modified polysiloxane, particularly 10% or more (e.g., 10 - 40%).

[0134] In one variant thereof, the polyether-modified polysiloxane is a polysiloxane to which poly(oxyalkylene) chains are grafted. Illustrative examples of the structure of such polyether-modified polysiloxanes are of formula (A):

[0135]

[0136] where each R 7 is independently selected from C 1-5 -alkyl (including straight-chain or branched hydrocarbon groups) and aryl (e.g., phenyl (-C6H5)), particularly methyl;

[0137] each R 8 is independently selected from -H, C 1-4 -alkyl (e.g., -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH2CH2CH3), phenyl (-C6H5) and C 1-4 -alkylcarbonyl (e.g., -C(=O)CH3, -C(=O)CH2CH3 and -C(=O)CH2CH2CH3), particularly -H, methyl and -C(=O)CH3;

[0138] each R 9 is independently selected from C 2-5 -alkylene (e.g., -CH2CH2-, -CH2CH(CH3), -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH(CH2CH3)-), arylene (e.g., 1,4-phenylene) and C 2-5 -alkylene substituted by aryl (e.g., 1-phenylethylene), particularly selected from C 2-5 -alkylene, such as -CH2CH2- and -CH2CH(CH3)-);

[0139] k is 0 - 240, l is 1 - 60 and k + l is 1 - 240; and

[0140] n ranges from 0 to 50, m ranges from 0 to 50 and m + n ranges from 1 to 50.

[0141] In particular, R 7 is methyl;

[0142] Each R 8 is independently selected from -H or C 1-4 -alkyl or -C(=O)CH3;

[0143] Each R 9 is -CH2CH2-, or -CH2CH2CH2-, or -CH2CH(CH3)-);

[0144] k ranges from 0 to 240, l ranges from 1 to 60 and k + l ranges from 1 to 240; and

[0145] n ranges from 0 to 50, m ranges from 0 to 50 and m + n ranges from 1 to 50.

[0146] Preferably, all R 7 groups are the same.

[0147] Examples of commercially available polyether-modified polysiloxanes of this type are KF352A, KF353, KF945, KF6012, KF6017 from ShinEtsu, and XIAMETER OFX-5220, DOWSIL OFX-5247, XIAMETER OFX-5329, XIAMETER OFX-5330 from DOW.

[0148] In another variant thereof, the polyether-modified polysiloxane is a polysiloxane having a poly(oxyalkylene) chain incorporated in its main chain. Illustrative examples of the structure of such a hydrophilic-modified polysiloxane are of formula (B):

[0149]

[0150] wherein each R 7 is independently selected from C 1-5 -alkyl (including straight-chain or branched-chain hydrocarbon groups) and aryl (such as phenyl (-C6H5)), in particular methyl;

[0151] Each R 8 is independently selected from -H, C 1-4 -alkyl (such as -CH3, -CH2CH3, -CH2CH2CH-CH(CH3)2, -CH2CH2CH2CH3), phenyl (-C6H5) and C 1-4 -alkylcarbonyl (such as -C(=O)CH3, C(=O)CH2CH3 and -C(=O)CH2CH2CH3), in particular -H, methyl and -C(=O)CH3;

[0152] Each R 9 is independently selected from C 2-5 -alkylene (e.g., -CH2CH2-, -CH2CH(CH3)-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH(CH2CH3)-), arylene (e.g., 1,4-phenylene) and C 2-5 -alkylene substituted with aryl (e.g., 1-phenylethylene), particularly selected from C 2-5 -alkylene, such as -CH2CH2- and -CH2CH(CH3)-);

[0153] k is 0 - 240;

[0154] and n is 0 - 50, m is 0 - 50 and m + n is 1 - 50.

[0155] In particular, wherein R 7 is methyl;

[0156] Each R 8 is independently selected from -H or C 1-4 -alkyl or -C(=O)CH3;

[0157] Each R 9 is -CH2CH2-, -CH2CH(CH3)- or -CH2CH2CH2-;

[0158] k is 0 - 240;

[0159] and n is 0 - 50, m is 0 - 50 and m + n is 1 - 50.

[0160] Preferably all R 7 groups are the same.

[0161] Commercially available hydrophilic modified polysiloxanes of this type are DOWSIL 2 - 8692 and XIAMETER OF X - 3667 from DOW.

[0162] In yet another variant, the polyether modified polysiloxane is a polysiloxane having polyoxyalkylene chains (polyoxyalkylene chains) incorporated in its main chain and polyoxyalkylene chains grafted thereto. Illustrative examples of the structure of such hydrophilic modified polysiloxanes are of formula (C):

[0163]

[0164] wherein each R 7 is independently selected from C 1-5-alkyl (including linear or branched hydrocarbon groups) and aryl groups (such as phenyl (-C6H5)), especially methyl;

[0165] Each R 8 is independently selected from -H, C 1-4 -alkyl (such as -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH2CH2CH3), phenyl (-C6H5) and C 1-4 -alkylcarbonyl (such as -C(=O)CH3, -C(=O)CH2CH3 and -C(=O)CH2CH2CH3), especially -H, methyl and -C(=O)CH3;

[0166] Each R 9 is independently selected from C 2-5 -alkylene (such as -CH2CH2-, -CH2CH(CH3)-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH(CH2CH3)-), arylene (such as 1,4-phenylene) and C 2-5 -alkylene substituted by aryl (such as 1-phenylethylene), especially selected from C 2-5 -alkylene, such as -CH2CH2- and -CH2CH(CH3)-);

[0167] k is 0 - 240, l is 1 - 60 and k + l is 1 - 240;

[0168] n is 0 - 50, m is 0 - 50 and m + n is 1 - 50.

[0169] In particular, R 7 is methyl;

[0170] Each R 8 is -H, or C 1-4 -alkyl or -C(=O)CH3;

[0171] Each R 9 is -CH2CH2-, -CH2CH2CH2-, - or -CH2CH(CH3)-;

[0172] k is 0 - 240, y is 1 - 60 and x + y is 1 - 240;

[0173] n is 0 - 50, m is 0 - 50 and m + n is 1 - 50.

[0174] In the above structures (A), (B), and (C), groups such as -CH2CH(CH3)-, -CH2CH(CH2CH3)-, etc. can exist in either of two possible orientations. Similarly, it should be understood that segments of k and l times are generally randomly distributed in the polysiloxane structure.

[0175] In these embodiments and variations, the polyether or poly(alkylene oxide) is preferably selected from polyethylene oxide, polypropylene oxide, and poly(ethylene oxide - co - propylene oxide), which are sometimes referred to as polyethylene glycol, polypropylene glycol, and poly(ethylene glycol - co - propylene glycol). Thus, in the above structures (A), (B), and (C), each R connecting two oxygen atoms 9 is preferably selected from -CH2CH2- and -CH2CH(CH3)-, while each R connecting a silicon atom and an oxygen atom 9 is preferably selected from C 2-5 -alkyl.

[0176] In some embodiments of the above structures (A), (B), and (C), R 8 is preferably not hydrogen.

[0177] It should be understood that one or more polyether - modified polysiloxanes can have different types, such as two or more of the above types.

[0178] In another preferred embodiment, the hydrophilic - modified polysiloxane contains polyglycerol groups or pyrrolidone groups.

[0179] Hydrophobic - modified polysiloxane

[0180] The coating composition of the present invention optionally further comprises a hydrophobic - modified polysiloxane oil. It should be understood that the hydrophobic - modified polysiloxane does not contain curing - reactive groups capable of reacting with the binder at the relevant curing temperatures (0 - 40 °C), such as Si - OH groups, Si - OR (alkoxy) groups, etc. Thus, the hydrophobic - modified polysiloxane is intended to be non - reactive in the curing reaction, especially with respect to the binder component. Generally, this component is not considered part of the binder system. The functional groups on the hydrophobic - modified polysiloxane should be selected such that they do not react in the curing reaction depending on the curing mechanism.

[0181] The hydrophobic - modified polysiloxane according to the present invention is a polysiloxane modified with hydrophobic groups to be more hydrophobic compared to the corresponding unsubstituted polysiloxane having the same number of polysiloxane units. Hydrophobicity can be obtained by modification with hydrophobic groups such as alkyl, cycloalkyl, and aryl groups. Generally, the hydrophobic - modified polysiloxane is an oil.

[0182] Preferred hydrophobically modified polysiloxanes are methylphenyl-functional polysiloxanes and methylaryl-functional polysiloxanes.

[0183] If present, the amount of hydrophobically modified polysiloxane present is preferably from 2.5 to 30 wt%, more preferably from 5 to 25 wt%, based on the total dry weight of the composition.

[0184] If present, the amount of hydrophobically modified polysiloxane present is preferably from 1.0 to 30 wt.%, more preferably from 4 to 20 wt.%, based on the total weight of the entire composition.

[0185] Although mixtures of more than one hydrophobically modified polysiloxane are within the scope of the present invention, it is preferred that only a single hydrophobically modified polysiloxane is present. In the case where two or more different types of hydrophobically modified polysiloxanes are present, the above wt% ranges refer to the sum of the hydrophobically modified polysiloxane components. In one embodiment, the coating composition comprises a mixture of a hydrophilically modified polysiloxane and a hydrophobically modified polysiloxane. In this embodiment, the hydrophilically modified polysiloxane and the hydrophobically modified polysiloxane may each be present in an amount of from 2.5 to 20 wt%, such as from 5 to 15 wt%, based on the total dry weight of the composition.

[0186] Crosslinking agent and / or curing agent

[0187] The polysiloxane adhesives of the present invention are curable and contain curing-reactive functional groups such as silanol, alkoxysilane, ketoxime, methanol, amine, epoxy group and / or alkoxy.

[0188] Preferably, the polysiloxane adhesive contains at least two curing-reactive functional groups. Optionally, the polysiloxane adhesive comprises more than one type of curing-reactive functional group. Preferably, the polysiloxane adhesive comprises a single type of curing-reactive functional group.

[0189] In a preferred polysiloxane adhesive, the curing-reactive functional group is silanol and / or alkoxysilane. In a further preferred polysiloxane adhesive, the curing-reactive functional group is silanol.

[0190] It is necessary to add a crosslinking agent or a curing agent to obtain the desired crosslink density. Depending on the curing-reactive functional groups present in the polysiloxane adhesive, a suitable crosslinking agent and / or curing agent is selected. The terms "crosslinking agent", "crosslinker" and "curing agent" are used interchangeably herein.

[0191] If the curing-reactive functional group is a silanol, the preferred crosslinking agent / curing agent is an organosilicon compound represented by the general formula (I) shown below, its partial hydrolysis-condensation product, or a mixture of both:

[0192] R d -Si-K 4-d (I)

[0193] Wherein,

[0194] each R is independently selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, a poly(alkylene oxide)-substituted or a structure (O-(CR D 2) r ’) r1 ’-(O-(CR D 2) s ’) s1 ’-(Si(R PP )2-O) t ’-Si(R PP )3 polysiloxane-substituted C 1-6 alkyl; wherein r’, r1’, s’ and s1’ are integers from 0 to 10, each R D is independently selected from H or C 1-4 alkyl, each R PP is independently selected from C 1-10 alkyl, C 6-10 aryl, C 7-10 alkylaryl and t’ is an integer from 1 to 50;

[0195] each K is independently selected from a hydrolyzable group such as an alkoxy group; and d is 0, 1 or 2, more preferably 0 or 1.

[0196] Preferred crosslinking agents of this type include tetraethoxysilane, vinyltris(methylethyloximo)silane, methyltris(methylethyloximo)silane, vinyltrimethoxysilane, methyltrimethoxysilane and vinyltriisopropenoxysilane and their hydrolysis-condensation products.

[0197] If the curing-reactive functional group is a di- or tri-alkoxy group, a separate crosslinking agent is generally not required.

[0198] In any embodiment of the present invention, the amount of crosslinker present is preferably up to 10 wt%, preferably 2.0 to 8.0 wt%, based on the total dry weight of the coating composition. Suitable crosslinkers are commercially available, such as Silicate TES-40WN from Wacker and Dynasylan A from Evonik.

[0199] If the curing-reactive functional group is methanol, preferred crosslinkers are monomeric isocyanates, polymeric isocyanates, and isocyanate prepolymers. Polyisocyanates are preferred over monomeric isocyanates because of lower toxicity. Polyisocyanates can be based, for example, on diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI) chemistry. These are supplied, for example, by Covestro under the trade name Desmodur and by Vencorex under the trade name Tolonate. Examples of polyisocyanates are Desmodur N3300, Desmodur 3390BA / SN, Desmodur N3400, Desmodur N3600, Desmodur N75, Desmodur XP2580, Desmodur Z4470, Desmodur XP2565, and Desmodur VL supplied by Covestro.

[0200] Polyisocyanates can be made to have different NCO-functionalities. The NCO-functionality is the amount of NCO-groups per polyisocyanate molecule or isocyanate prepolymer molecule. Polyisocyanate curing agents with different NCO-functionalities can be used.

[0201] Relative to the amount of hydroxyl groups, the crosslinker is preferably present in an amount of 0.8 - 2.5 equivalents (equiv) of NCO groups, preferably 0.9 - 2.0 equivalents, more preferably 0.95 - 1.7 equivalents, and even more preferably 1 - 1.5 equivalents.

[0202] If the curing-reactive functional group is amine, epoxy, or isocyanate, the crosslinker is preferably an amine, sulfur, or epoxy-functional group.

[0203] The crosslinker / curing agent can also be a dual crosslinker / curing agent containing, for example, both amine / sulfur / epoxy / isocyanate and an alkoxysilane. Preferred dual curing agents are represented by the following general formula (II):

[0204]

[0205] where

[0206] LL is independently selected from unsubstituted or substituted monovalent hydrocarbon groups having 1 to 6 carbon atoms;

[0207] Each M is independently selected from hydrolyzable groups such as alkoxy groups;

[0208] a is 0, 1 or 2, preferably 0 or 1;

[0209] b is an integer from 1 to 6; and

[0210] Fn is an amine, epoxy group, glycidyl ether, isocyanate or sulfur group.

[0211] Preferred examples of such dual curing agents include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (3-glycidoxypropyl)trimethoxysilane, 3-mercaptopropyltrimethoxysilane. A particularly preferred curing agent is 3-aminopropyltriethoxysilane, such as Dynasylan AMEO from Evonik.

[0212] This type of dual curing agent can be used as a sole curing agent or for end-capping polysiloxane adhesives, such that the end groups of the polysiloxane adhesives are modified prior to the curing reaction.

[0213] The preferred composition comprises a crosslinking agent of formula I or a dual crosslinking agent of formula II or a mixture thereof.

[0214] Preferably, the adhesive is not a one-component room temperature vulcanising (RTV-1) or self-curing adhesive.

[0215] In a particularly preferred embodiment, the crosslinking agent / curing agent in the present application is not water.

[0216] Catalyst component

[0217] To assist the curing process, the coating composition of the present invention may comprise a catalyst component. The catalyst can be an organic or inorganic or organometallic catalyst.

[0218] Metal catalyst

[0219] In one embodiment, the coating composition of the present invention comprises a metal catalyst. Representative examples of catalysts that can be used include catalysts containing Sn, Zn, Li, K, Bi, Fe, Ce or Zr, such as their salts and organometallic complexes. The salts are preferably salts of long-chain carboxylic acids and / or chelates or organometallic salts.

[0220] The metal catalyst is preferably a tin(IV), bismuth(III), iron(II), iron(III), zinc(II), zirconium(IV), cerium(III), potassium or lithium compound. Tin(IV), bismuth(III), zinc(II) and cerium(III) are particularly preferred.

[0221] Examples of anionic organic groups include methoxide, ethoxide, n-propoxide, isopropoxide, n-butoxide, isobutoxide, sec-butoxide, tert-butoxide, triethanolaminate and 2-ethylhexoxide; carboxylate radical groups, such as acetate, formate, n-octanoate, 2-ethylhexanoate, 2,4,4-trimethylpentanoate, 2,2,4-trimethylpentanoate, 6-methylheptanoate, oleate, ricinoleate, palmitate, hexanoate, hexadecanoate, 2-ethylhexanoate, benzoate, 1,4-dibenzoate, stearate, acrylate, laurate, methacrylate, 2-carboxyethyl acrylate, oxalate, 10-undecenoate, dodecanoate, citrate, 3-oxopentanoate, 3-oxobutanoate and neodecanoate radical groups; amide groups, such as dimethylamide, diethylamide, ethylmethylamide and dipropylamide; lactate radical groups; trialkylsilyloxy groups, more particularly trimethylsilyloxy and triethylsilyloxy, and also carbonate groups (O-CO-OR′) and carbamate groups (O-CO-NR′2), where R' may be the same or different and is a monovalent or divalent, optionally substituted hydrocarbon group, and further may be hydrogen, trimethoxysilylpropyl, triethoxysilylpropyl, dimethoxymethylsilylpropyl, diethoxymethylsilylpropyl, N-[3-(trimethoxysilyl)propyl]-2-aminoethyl, N-[3-(triethoxysilyl)propyl]-2-aminoethyl, N-[3-(dimethoxymethylsilyl)propyl]-2-aminoethyl or N-[3-(diethoxymethylsilyl)propyl]-2-aminoethyl.

[0222] Examples of metal salt compounds are dibutyltin diacetate, dioctyltin dilaurate, dibutyltin dilaurate, dibutyltin oxide, bismuth(III) 2-ethylhexanoate, bismuth(III) neodecanoate, bismuth(III) acetate, bismuth(III) octanoate, iron(II) acetate, iron(III) tert-butoxide, iron(III) citrate, iron(II) lactate, iron(II) oxalate, iron(III) oxalate, iron(III) 2-ethylhexanoate, cerium(III) neodecanoate, zinc(II) acetate, zinc(II) formate, zinc(II) benzoate, zinc(II) 2-ethylhexanoate, zinc(II) n-octanoate, zinc(II) stearate, zinc(II) ethanolate, zinc(II) acrylate, zinc(II) methacrylate, zinc(II) naphthenate, zinc(II) oxalate, zinc(II) 10-undecenoate, zinc(II) 3-oxopentanoate, zinc(II) 3-oxobutanoate, zirconium(IV) acetate, zirconium(IV) 2-ethylhexanoate, zirconium(IV) lactate, zirconium(IV) n-butoxide, zirconium(IV) tert-butoxide, zirconium(IV) isopropoxide, zirconium(IV) n-propoxide, zirconium(IV) 2-carboxyethyl acrylate, zirconium(IV) tetra(diethylamide), zirconium(IV) tetra(ethylmethylamide), zirconium(IV) bis(diethylcitrate)-di-n-propoxide (zirconium(IV)bis(diethylcitrate)-di-n-propoxide).

[0223] Examples of metal chelate compounds are bismuth(III) 2,2,6,6-tetramethyl-3,5-heptanedionate, bismuth(III) acetylacetonate, iron(II) acetylacetonate, iron(III) acetylacetonate, iron(III) 2,2,6,6-tetramethyl-3,5-heptanedionate, iron(II) 2,2,6,6-tetramethyl-3,5-heptanedionate, zinc(II) hexafluoroacetylacetonate, zinc(II) 1,3-diphenyl-1,3-propanedionate (zinc(II)1,3-diphenyl-1,3-propanedionate), zinc(II) 1-phenyl-5-methyl-1,3-hexanedionate, zinc(II) 1,3-cyclohexanedionate, zinc(II) 2-acetylcyclohexanecarboxylate, zinc(II) 2-acetyl-1,3-cyclohexanedicarboxylate, zinc(II) ethyl salicylate, zinc(II) diethylmalonate, zinc(II) ethyl acetoacetate, zinc(II) benzyl salicylate, zinc(II) acetylacetonate, and zinc(II) 2,2,6,6-tetramethyl-3,5-heptanedionate, tin(II) acetylacetonate, zirconium(IV) acetylacetonate, zirconium(IV) 2,2,6,6-tetramethyl-3,5-heptanedionate, zirconium(IV) trifluoroacetylacetonate, and zirconium(IV) hexafluoroacetylacetonate.

[0224] Examples of suitable tin catalysts are dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin diacetate, dioctyltin dilaurate. Examples of commercially available tin catalysts include BNT-CAT 400 and BNT-CAT 500 from BNT Chemicals, FASCAT 4202 from PMC Organometallix, and Metatin Katalysator 702 from DOW.

[0225] Examples of suitable lithium catalysts are lithium 2-ethylhexanoate and lithium neodecanoate. Examples of commercially available lithium catalysts include Borchers Deca Lithium 2 manufactured by Borchers.

[0226] Examples of suitable potassium catalysts are potassium 2-ethylhexanoate and potassium neodecanoate. Examples of commercially available potassium catalysts include 15% Potassium manufactured by Borchers EU and TIB KAT K30 from TIB Chemicals.

[0227] Examples of suitable zinc catalysts are zinc 2-ethylhexanoate, zinc naphthenate, and zinc stearate. Examples of commercially available zinc catalysts include K-KAT XK-672 and K-KAT 670 from King Industries, and BorchiKat 22 from Borchers.

[0228] Examples of suitable bismuth catalysts are organobismuth compounds such as bismuth 2-ethylhexanoate, bismuth octanoate, and bismuth neodecanoate. Examples of commercial organobismuth catalysts are Borchi Kat 24 and Borchi Kat 315 from Borchers, K-KAT XK-651 from King Industries, Reaxis C739E50 from Reaxis, and TIB KAT 716 from TIB Chemicals.

[0229] An example of a suitable cerium catalyst is cerium(III) neodecanoate.

[0230] Other suitable catalysts are iron catalysts such as iron stearate and iron 2-ethylhexanoate, and zirconium catalysts such as zirconium naphthenate, tetrabutyl zirconate, tetra(2-ethylhexyl) zirconate, triethanolamine zirconate, tetra(isopropenyloxy)-zirconate, zirconium tetrabutoxide, zirconium tetrapropoxide, and zirconium tetraisopropoxide. Further suitable catalysts are zirconates.

[0231] In a preferred embodiment, the metal additive is a tin, zinc, and / or cerium catalyst.

[0232] In a preferred embodiment, the catalyst does not contain tin.

[0233] Preferably, the metal catalyst is present in the coating composition of the present invention in an amount of 0.05 to 5.0 wt%, more preferably 0.1 to 2.0 wt%, based on the total dry weight of the coating composition.

[0234] This component is not considered part of the binder system.

[0235] Organic catalyst

[0236] The catalyst can also be organic, such as low molecular weight amidines or low molecular weight amine compounds, such as aminosilanes. The term low molecular weight means that its molecular weight is less than 1000 g / mol, such as 50 to 500 g / mol, preferably 100 to 400 g / mol. In a preferred embodiment, the low molecular weight amidine or low molecular weight amine compound is not guanidine or a guanidine derivative. In a more preferred embodiment, the coating composition disclosed herein does not contain any guanidine catalysts.

[0237] Guanidine derivatives are compounds containing the following moiety:

[0238]

[0239] Suitable amidines are compounds containing the following moiety:

[0240]

[0241] Preferably, the amidine is represented by the following general formula:

[0242]

[0243] wherein R1, R2, R4 are each independently selected from hydrogen, monovalent organic groups, monovalent heteroorganic groups, and combinations thereof;

[0244] R3 is a monovalent organic group, a monovalent heteroorganic group, and combinations thereof;

[0245] and / or wherein any two or more of R1, R2, R3, R4 are optionally capable of bonding together to form a ring structure.

[0246] R1, R2 and R4 are preferably hydrogen or C1-6 alkyl or phenyl.

[0247] R3 is C 1-6 alkyl or phenyl.

[0248] Even more preferably, R2 + R4 together form a ring and / or R1 + R3 together form a ring. Such a ring is preferably an aliphatic 5-7 membered ring.

[0249] Preferred choices include cyclic amidines, preferably bicyclic amidines such as 1,8-diazabicyclo-5.4.0-7-undecene (DBU). The chemical structure of DBU is shown below:

[0250]

[0251] The catalyst can also be a low molecular weight organic amine compound such as triethylamine, cyclic amine, tetramethylethylenediamine, 1,4-ethylene piperazine and pentamethyldiethylenetriamine.

[0252] However, the preferred amine is an aminosilane such as an aminoalkyltrialkoxysilane such as 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane, or bis(alkyltrialkoxysilyl)amine, preferably bis(3-propyltrimethoxysilyl)amine or bis(3-propyltriethoxysilyl)amine. Another option is N,N-dibutylaminomethyl-triethoxysilane.

[0253] Suitable aminosilanes have the general formula (I) or (II)

[0254] (I) Y-R (4-z) SiX z

[0255] where z is an integer from 1 to 3,

[0256] (II) Y-R (3-y) R 1 SiX y

[0257] where y is an integer from 1 to 2,

[0258] Each R is a hydrocarbon group having 1 to 12 C atoms optionally containing an ether or amino linker,

[0259] R 1 is a hydrocarbon group having 1 to 12 C atoms;

[0260] Each X independently represents an alkoxy group.

[0261] Y is an amino group bonded to R.

[0262] The Y group can be bonded to any part of the chain R.

[0263] The amino group is preferably N-di-C1-6-alkyl or NH2.

[0264] Particularly preferably, X is a C1-6 alkoxy group, especially methoxy or ethoxy. It is also particularly preferred that there are two or three alkoxy groups. Thus, z is desirably 2 or 3, especially 3.

[0265] The subscript y is preferably 2.

[0266] R 1 is preferably a C1-4 alkyl group, such as methyl.

[0267] R is a hydrocarbon group having up to 12 carbon atoms. A hydrocarbon group means a group containing only C and H atoms. It may contain an alkylene chain or a combination of an alkylene chain and a ring such as a phenyl or cyclohexyl ring. The term "optionally containing an ether or amino linker" means that the carbon chain may be interrupted by -O- or -NH- groups in the chain.

[0268] R is preferably an unsubstituted (except for Y, obviously), straight-chain alkyl chain having 2 to 8 C atoms.

[0269] Therefore, the preferred general formula of the silane has the structure (III)

[0270] (III) Y'-R'( 4-z' )SiX' z

[0271] where z' is an integer from 2 to 3,

[0272] R' is an unsubstituted, straight-chain alkyl chain having 2 to 8 C atoms that optionally contains an ether or amino linker,

[0273] Y' is an amino functional group bonded to the R' group, and

[0274] X' represents an alkoxy group.

[0275] Examples of such silanes are numerous representatives: products produced by Degussa in Rheinfelden and sold under the trade name Dynasylan(R) D, Silquest(R) silanes produced by Momentive, and GENOSIL(R) silanes produced by Wacker.

[0276] Preferred aminosilanes include aminopropyltrimethoxysilane (Dynasylan AMMO; Silquest A-110), aminopropyltriethoxysilane (Dynasylan AMEO), or N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (Dynasylan DAMO, Silquest A-1120), N-(2-aminoethyl)-3-aminopropyltriethoxysilane, triaminofunctional trimethoxysilane (Silquest A-1130), bis(γ-trimethoxysilylpropyl)amine (Silquest A-1170), N-ethyl-γ-aminoisobutyltrimethoxysilane (Silquest A-Link 15), N-phenyl-γ-aminopropyltrimethoxysilane (Silquest Y-9669), 4-amino-3,3-dimethylbutyltrimethoxysilane (Silquest Y-11637), (N-cyclohexylaminomethyl)triethoxysilane (Genosil XL 926), (N-phenylaminomethyl)trimethoxysilane (Genosil XL 973), and mixtures thereof.

[0277] Other particularly interesting silanes include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(aminoethyl)-aminopropyltrimethoxysilane H2NCH2CH2NHCH2CH2CH2Si(OCH3)3, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethylamino)propylmethyldimethoxysilane (H2NCH2CH2NHCH2CH2CH2SiCH3(OCH3)2).

[0278] It should be understood that due to the presence of alkoxysilyl groups, aminosilanes can act as catalysts and crosslinking agents.

[0279] The amount of organic catalyst present in the coating composition can be from 0.05 to 5.0 wt%, preferably 0.1 to 4.0 wt%, such as 0.25 to 4.0 wt%, more preferably 0.5 to 3.0 wt% of the coating composition (dry weight).

[0280] Antifouling agent / Biocide

[0281] The fouling release coating composition of the present invention may comprise an antifouling agent / biocide.

[0282] The terms antifouling agent, bioactive compound, antifoulant, biocide, and poison are used in the industry to describe known compounds that are used to prevent marine fouling on surfaces. These terms may be used interchangeably herein. If present, the antifouling agent can be inorganic, organometallic, or organic. Preferably, if present, the antifouling agent is an organometallic antifouling agent. Suitable antifouling agents are commercially available.

[0283] Examples of inorganic antifouling agents include copper and copper compounds such as copper oxides, e.g., cuprous oxide and copper oxide; copper alloys, e.g., copper-nickel alloy; copper salts, e.g., copper thiocyanate and copper sulfide.

[0284] Examples of organometallic antifouling agents include zinc pyrithione; organocopper compounds such as copper pyrithione, copper acetate, copper di(ethyl 4,4,4-trifluoroacetoacetate), copper naphthenate, quinolinone, copper nonylphenolsulfonate, bis(ethylenediamine)bis(dodecylbenzenesulfonic acid) copper, and copper bis(pentachlorophenol); dithiocarbamate compounds such as zinc bis(dimethyldithiocarbamate) [ziram], zinc ethylenebis(dithiocarbamate) [zineb], manganese ethylenebis(dithiocarbamate) [maneb], and manganese ethylenebis(dithiocarbamate) complexed with zinc salt [mancozeb].

[0285] Examples of organic antifouling agents include heterocyclic compounds such as 2-(tert-butylamino)-4-(cyclopropylamino)-6-(methylthio)-1,3,5-triazine [cybutryne], 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one [DCOIT], encapsulated 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one [DCOIT], 1,2-benzisothiazolin-3-one, 2-(thiocyanatomethylthio)-1,3-benzothiazole (2-(thiocyanatomethylthio)-1,3-benzothiazole, 2-(thiocyanatomethylthio)-1,3-benzothiazole) [benthiazole] and 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine; urea derivatives such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea [diuron]; amides and imides of carboxylic acids, sulfonic acids and sulphenic acids, such as N-(dichlorofluoromethylthio)phthalimide, N-dichlorofluoromethylthio-N',N'-dimethyl-N-phenylsulfamide [dichlofluanid], N-dichlorofluoromethylthio-N',N'-dimethyl-N-p-tolylsulfamide [tolylfluanid] and N-(2,4,6-trichlorophenyl)maleimide; other organic compounds such as pyridine triphenylborane [TPBP], amine triphenylborane, 3-iodo-2-propynyl N-butylcarbamate [iodocarb], 2,4,5,6-tetrachloroisophthalonitrile, p-((diiodomethyl)sulfonyl)toluene and 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile [tralopyril] and quaternary ammonium salts.

[0286] Other examples of antifouling agents include tetraalkylphosphonium halogenides, guanidine derivatives, imidazole-containing compounds such as 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole [mepenzolate] and its derivatives, macrolides including avermectins and their derivatives such as ivermectin, spinosyns and their derivatives such as spinosad, capsaicin and its derivatives such as phenyl capsaicin, and enzymes such as oxidases, proteolytically active enzymes, hemicellulolytically active enzymes, cellulolytically active enzymes, lipolytically active enzymes and amylolytically active enzymes.

[0287] Preferred antifouling agents are zinc pyrithione, copper pyrithione, zinc ethylenebis(dithiocarbamate) [zineb], 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one [DCOIT] and encapsulated 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one [DCOIT]. Particularly preferred antifouling agents are zinc pyrithione and copper pyrithione, especially copper pyrithione.

[0288] If present, the biocide may be present in an amount of 1-20% by dry weight of the total coating composition, preferably 1-15%, 2-15% or 3-12% by dry weight of the total coating composition.

[0289] This component is not considered part of the binder system.

[0290] Pigment

[0291] The coating composition of the present invention preferably comprises one or more pigments. The pigments may be inorganic pigments, organic pigments or mixtures thereof. Inorganic pigments are preferred. The pigments may be surface-treated.

[0292] Representative examples of pigments include iron oxide black, iron oxide red, iron oxide yellow, titanium dioxide, zinc oxide, carbon black, graphite, red molybdate, yellow molybdate, zinc sulfide, antimony oxide, sodium aluminiumsulfosilicates, quinacridones, phthalocyanine blue, phthalocyanine green, indanthrone blue, cobalt aluminate, carbazoledioxazine, isoindoline orange, bis-acetoaceto-tolidiole, benzimidazolone, quinaphthaloneyellow, isoindoline yellow, tetrachloroisoindolinone, and quinophthaloneyellow (quinaphthaloneyellow), metallic flake materials (such as aluminium flakes). Preferred pigments are iron oxide black, iron oxide red, iron oxide yellow, phthalocyanine blue and titanium dioxide. In a preferred embodiment, titanium dioxide is surface-treated with a silicone compound, a zirconium compound, an aluminium compound and / or a zinc compound.

[0293] Based on the total dry weight of the coating composition, the amount of pigment present in the coating composition of the present invention is preferably from 0 to 25 wt%, and more preferably from 0.5 to 15 wt%.

[0294] This component is not considered part of the binder system.

[0295] Solvent

[0296] The coating composition of the present invention preferably contains a solvent. The solvents suitable for use in the compositions of the present invention are commercially available.

[0297] Examples of suitable organic solvents and diluents are aromatic hydrocarbons such as xylene, toluene, mesitylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl isoamyl ketone, cyclopentanone, cyclohexanone; esters such as butyl acetate, tert-butyl acetate, amyl acetate, isoamyl acetate, ethylene glycol methyl ether acetate (ethyleneglycol methyl ether acetate), propylene glycol methyl ether acetate; ethers such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dibutyl ether, dioxane, tetrahydrofuran; alcohols such as n-butanol, isobutanol, benzyl alcohol; ether alcohols such as butoxyethanol, 1-methoxy-2-propanol; aliphatic hydrocarbons such as white spirit; and optionally a mixture of two or more solvents and diluents.

[0298] The amount of solvent present in the soil release coating composition of the present invention is preferably as low as possible, as this minimizes the VOC content. Preferably, based on the total weight of the composition, the amount of solvent present in the composition of the present invention is 0 - 35 wt%, and more preferably 1 - 30 wt%. Those skilled in the art will understand that the solvent content will vary depending on the other components present.

[0299] This component is not considered part of the binder system.

[0300] Filler

[0301] The coating composition of the present invention optionally contains a filler. Examples of fillers that can be used in the coating composition according to the present invention are zinc oxide, barium sulfate, calcium sulfate, calcium carbonate, silica or silicates (such as talc, feldspar, kaolin and nepheline syenite), including fumed silica, bentonite and other clays, and solid silicone resins, which are generally condensed branched polysiloxanes. Some fillers such as fumed silica may have a thickening effect on the coating composition.

[0302] Preferred fillers are fumed silica fillers. The fumed silica fillers can have an untreated surface or a hydrophobically modified surface. Preferably, the fumed silica fillers have a hydrophobically modified surface. Examples of commercially available fumed silica fillers are TS-610, TS-530, EH-5, H-5 and M-5 from Cabot, and R972, R974, R976, R104, R202, R208, R805, R812, 816, R7200, R8200, R9200, R711.

[0303] The amount of filler present in the coating composition of the present invention is preferably 0 to 25 wt%, more preferably 0.1 to 10 wt% and still more preferably 0.15 to 5.0 wt%, based on the total dry weight of the coating composition.

[0304] This component is not considered part of the adhesive system.

[0305] additive

[0306] The coating composition of the present invention optionally comprises one or more additives. Examples of additives that may be present in the coating composition of the present invention include reinforcing agents, thixotropic agents, thickeners, anti-settling agents, dehydrating agents, dispersants, wetting agents, surfactants, binders, plasticizers and dyes.

[0307] Examples of thixotropic agents, thickeners and anti-settling agents are silica such as pyrogenic silica, organic modified clays, amide waxes, polyamide waxes, amide derivatives, polyethylene waxes, oxidized polyethylene waxes, hydrogenated castor oil waxes and mixtures thereof. Preferably, the thixotropic agent, thickener and anti-settling agent are each present in the composition of the present invention in an amount of 0-10 wt %, more preferably 0.1-6 wt %, and still more preferably 0.1-2.0 wt %, based on the total dry weight of the composition.

[0308] Dehydrating agents and driers that can be used in the coating composition include organic and inorganic compounds. Dehydrating agents can be hygroscopic materials that absorb water or bind water as water of crystallization, commonly referred to as desiccants. Examples of desiccants include calcium sulfate hemihydrate, anhydrous calcium sulfate, anhydrous magnesium sulfate, anhydrous sodium sulfate, anhydrous zinc sulfate, molecular sieves, and zeolites. Dehydrating agents can be compounds that react chemically with water. Examples of the dehydrating agent that reacts with water include orthoesters such as trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, triisopropyl orthoformate, tributyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, tributyl orthoacetate, and triethyl orthopropionate; ketals; acetals; enol ethers; orthoborates such as trimethyl borate, triethyl borate, tripropyl borate, triisopropyl borate, tributyl borate, and tri-tert-butyl borate; and organosilanes such as trimethoxymethylsilane, vinyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, and polyethyl silicate.

[0309] Preferably, based on the total dry weight of the composition, the dehydrating agent is present in the composition of the present invention in an amount of 0 - 5 wt%, more preferably 0.5 - 2.5 wt%, and even more preferably 1.0 - 2.0 wt%.

[0310] Compositions and paints

[0311] The coating compositions as described herein can be prepared at a suitable concentration for use, for example, as spray paint. In this case, the composition itself is a paint. Alternatively, the composition can be a concentrate for preparing a paint. In this case, further solvents and optionally other components can be added to the composition described herein to form a paint. Preferred solvents are as described above for the composition.

[0312] After mixing, and optionally after adding the solvent, the soil release coating composition or paint is preferably loaded into a container. Suitable containers include cans, barrels, and tanks.

[0313] The coating composition can be provided as a one - pack, as a two - pack, or as a three - pack. Preferably, the composition is provided as a two - pack or as a three - pack.

[0314] When provided as a two - pack, the first container preferably contains one or more polysiloxane binders and the second container preferably contains any curing agent and catalyst. Instructions for mixing the contents of the containers can be provided optionally. Any hydrophilically modified polysiloxane is preferably part of the first container. Any catalyst is preferably part of the second container.

[0315] The solids content of the coating compositions and paints of the present invention is preferably 50 - 99 wt%, more preferably 60 - 99 wt%, and even more preferably 65 - 99 wt%.

[0316] Preferably, the coating compositions and paints of the present invention have a volatile organic compound (VOC) content of 0 to 400 g / L, preferably 0 to 350 g / L, for example 0 to 300 g / L. The VOC content can be calculated (ASTM D5201 - 05A) or measured (US EPA method 24 or ISO 11890 - 1).

[0317] The coating composition of the present invention can be applied to any pretreatment coating designed for polysiloxane-based soil release coatings. Examples of such coatings are epoxy anticorrosive primer layers and silicone-containing tie-layers, which are designed to ensure adhesion between the substrate and the final polysiloxane-based coating composition layer. An example of such a tie-layer is described in WO2013 / 107827. Optionally, the tie-layer can contain antifouling agents. Such epoxy primers and tie coatings are well known in the art and are commercially available.

[0318] Method

[0319] The method of the present invention comprises applying at least two coatings of the polysiloxane-based coating composition as defined above. Specifically, the method is characterized by the following:

[0320] i) applying a first coating by spraying to a wet film thickness of 50 - 300 μm; and

[0321] ii) applying a second coating by spraying to a wet film thickness of 50 - 300 μm;

[0322] wherein, 5 minutes - 6 hours after applying the first coating, the second coating is applied directly on top of the first coating.

[0323] The polysiloxane-based coating composition of the first coating can be the same as or different from the polysiloxane-based coating composition of the second coating. In certain embodiments, the first coating and the second coating will be the same. In cases where the first coating is not the same as the second coating, preferably they are substantially the same. As used herein, "substantially the same" means that the coatings differ only in the type and amount of pigments and / or additives that may be present. If the coatings are substantially the same, they will have the same type and amount of crosslinking agent, binder, additive oil, and biocide. However, their pigments can be different.

[0324] Preferably, the first coating composition and the second coating composition have the same crosslinking agent, binder, additive oil, and biocide (whichever are present). They can be present in different amounts in the first coating composition and the second coating composition, or they can be present in the same amount in the first coating composition and the second coating composition.

[0325] Preferably, two thin top coatings are applied (i.e., wet film thickness of 50 - 300 μm, preferably 100 - 2750 μm, such as 125 - 275 μm), rather than one thick top coating (i.e., wet film thickness greater than 250 μm, especially greater than 300 μm, such as 300 to 600 μm). Further preferably, the wet film thicknesses of the two coatings are equal or differ by within 50 μm from each other.

[0326] In one embodiment, the first coating and the second coating are top coatings that are present in addition to any tie layer and / or primer layer that may be present.

[0327] It should be understood that once applied, the coating composition will begin to cure.

[0328] The coating composition of the present invention is typically applied (and cured) at a temperature of 5 to 50 °C, preferably 10 to 40 °C, and more preferably 10 to 30 °C.

[0329] The coating composition of the present invention is typically applied (and cured) at a humidity of 20 - 90%, preferably 30 - 85%, and more preferably 40 - 85%.

[0330] The coating composition and paint of the present invention can be applied to all or part of the surface of any article that has been subjected to marine pollution. This surface may be permanently or intermittently underwater (e.g., through tidal movements, different cargo loadings, or swell). The surface of the article is typically the surface of a ship's hull or a fixed marine object such as an oil platform or a buoy.

[0331] The application of the coating composition and paint can be accomplished by any convenient spraying method. For example, the first coating and the second coating can be applied one after another along the ship by two separate cherrypickers. The application can also be performed by an automated process or a paint application robot. Generally, it is necessary to separate the surface from the seawater to allow for coating. The application of the coating can be achieved as is commonly known in the art. After applying the coating, it is preferably dried and / or cured.

[0332] Coating System and Application

[0333] The coating system of the present invention is desirably a fouling release coating system. As defined above, the coating system of the present invention comprises at least the first coating and the second coating as described above. It should be understood that the coating system can comprise additional layers, such as at least one tie coat layer and / or at least one epoxy primer layer. As described above, such layers are known in the art. In such an embodiment, it is generally allowed for the tie coat layer and the epoxy primer layer to cure for at least 24 hours before applying the subsequent layer.

[0334] Generally, the first coating and the second coating form the outermost layer of the coating system. Additionally, it is preferred that the second coating is the outermost layer of the coating system.

[0335] The coating system of the present invention is typically applied to the surface of a marine substrate, preferably to the submerged portion of a marine structure during use. Typical marine substrates include ships (including but not limited to all types of boats, ships, yachts, motorboats, launches, ocean liners, tugboats, tankers, container ships and other cargo ships, submarines and naval vessels), pipelines, all types of onshore and offshore machinery, buildings and objects such as docks, piles, bridge substructures, hydraulic facilities and structures, underwater well structures, nets and other aquaculture facilities, and buoys, etc. The surface of the substrate can be a "natural" surface (e.g., a steel surface).

[0336] Examples

[0337] Determination of the viscosity of the binder

[0338] The viscosity of the binder was determined at 12 rpm using a Brookfield DV-I Prime digital viscometer with an LV-2 or LV-4 rotor according to ASTM D2196 Test Method A. Before measurement, the binder was adjusted (tempered) to 23.0 °C ± 0.5 °C.

[0339] Determination of the average molecular weight distribution of the polymer

[0340] The polymer was characterized by gel permeation chromatography (GPC) measurements. Using a Malvern Omnisec Resolve and Reveal system, with two Agilent PLgel 5 μm Mixed-D columns in series, the molecular weight distribution (MWD) was determined. The columns were calibrated by conventional calibration using narrow polystyrene standards. The analysis conditions are shown below.

[0341]

[0342] Samples were prepared by dissolving a quantity of polymer solution corresponding to 25 mg of dry polymer in 5 ml of THF. The samples were held at room temperature for at least 3 hours before sampling for GPC measurement. Before analysis, the samples were filtered through a 0.45 μm nylon filter. The number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity index were reported.

[0343] Preparation of the soil release coating composition

[0344] A coating composition was prepared by first mixing the components in part (A) shown in Table 1 below using a high-speed dissolver equipped with an impeller disc. First, the polysiloxane binder, copper pyrithione, hydrophobic silica, and iron oxide red (red iron oxide) were stirred at high speed until a grinding fineness of less than 20 μm was achieved. Then the remaining components were added under low-speed stirring. Shortly before applying the coating, the components in part (B) were mixed with the components in part (A).

[0345] Preparation of the coating system

[0346] According to the corresponding product technical data sheet, a dirt-release coating topcoat (formulation shown in Table 1) was applied by airless spraying onto upright PVC panels of a commercial system coated with 1x 200 μm epoxy primer (Jotacoat Universal N10 from Jotun) and 1x 160 μm dirt-release coating tie coat (Safeguard FRC PE from Jotun). Both the epoxy primer and the tie coat were cured for 24 hours before applying the next layer. The topcoat was cured under various conditions using a climatic chamber that controlled temperature and relative humidity. Two layers of the topcoat were applied at set time intervals ranging from 5 to 120 minutes. The sag resistance and adhesion of 23 examples and 2 comparative examples were measured and reported in Table 2.

[0347] Evaluation of sag resistance

[0348] The topcoat was applied using an airless spraying pump at a pressure of 4.5 bar and a nozzle size of 627 μm. The application was carried out on upright panels with a 50% overlap to achieve a uniform film thickness. The film thickness was measured immediately after application using a WFT comb. A horizontal line was scratched in the paint at the bottom of the panel using a spatula to control sag.

[0349] Sag was observed in the created line. When the coating was fully cured, typically on the day after application, the sag of the applied WFT was evaluated and reported.

[0350] Evaluation of adhesion

[0351] The adhesion of two topcoats was evaluated on panels immersed in seawater 24 hours after applying the final coat (wet adhesion) and on panels not immersed in seawater after application (dry adhesion).

[0352] According to the overcoating intervals given in the product technical data sheet and the selected overcoating intervals between the topcoats, panels of the coating system were prepared by airless spraying. The panels were set to cure for 24 hours under the selected curing conditions.

[0353] To evaluate the wet adhesion, the plate was immersed in seawater for 48 hours. To evaluate the dry adhesion, the plate was stored at RT / 50 °C for at least 48 hours.

[0354] The wet and dry adhesions were evaluated by cross-cutting and visually assessing the interlayer adhesion or delamination between the top coatings.

[0355] Table 1 - Topcoat Composition

[0356]

[0357] 1 Mn: 8385 g / mol, Mw: 24238 g / mol, PDI: 2.891, Viscosity (23 °C): 440 mPas; 2 Mn: 46945 g / mol, Mw: 98279 g / mol, PDI: 2.093, Viscosity (23 °C): 22050 mPas; 3 Mn: 2805 g / mol, Mw: 5811 g / mol; 4 Mw 7460 g / mol, HLB 4.7; 5 TES 40WN 6 TIB KAT 233, from TIB chemicals, mixing ratio between parts A and B is 100:8.4.

[0358]

[0359]

Claims

1. A method for preparing a multi-layer coating system comprising at least two coatings, wherein i) a first coating is applied by spraying to a wet film thickness of 50 - 300 μm; and ii) a second coating is applied by spraying to a wet film thickness of 50 - 300 μm; Among them, the second coating is applied directly on top of the first coating 5 minutes to 6 hours after applying the first coating; and wherein the first coating and the second coating independently comprise a polysiloxane-based coating composition, the polysiloxane-based coating composition comprising: a) a polysiloxane-based binder system; and b) a curing agent or crosslinking agent.

2. The method according to claim 1, wherein, The second coating is applied 5 minutes to 4 hours after applying the first coating, preferably 5 minutes to 2 hours after applying the first coating.

3. The method according to claim 1 or 2, wherein, The coating system is a dirt release coating system.

4. The method according to any one of claims 1 to 3, wherein, The first coating and the second coating comprise the same or different polysiloxane-based coating compositions, preferably the same.

5. The method according to any one of claims 1 to 4, wherein The first coating and the second coating are the outermost layers of the coating system.

6. The method according to any one of claims 1 to 5, wherein The second coating is the outermost layer of the coating system.

7. The method according to any one of claims 1 to 6, wherein The first coating and / or the second coating comprise one or more additive oils.

8. The method according to any one of claims 1 to 7, wherein, The first coating and / or the second coating comprise hydrophilically modified polysiloxane and / or hydrophobically modified polysiloxane.

9. The method according to any one of claims 1 to 8, wherein The first coating and / or the second coating comprise a biocide.

10. The method according to any one of claims 1 to 9, wherein, The polysiloxane-based binder system comprises a polysiloxane of formula (D1): wherein Each R 1 is independently selected from a hydroxyl group, a C 1-6 -alkoxy group, or an O-Si(R 5 ) 3-z (R 6 ) z , a C 1-6 -hydroxyl group, a group containing a C 1-6 -epoxy group, a C 1-6 -amino group, a C 1-10 -alkyl group, a C 6-10 -aryl group or a C 7-10 -alkaryl group. Each R 2 is independently selected from C 1-10 alkyl, C 6-10 aryl, C 7-10 alkylaryl or C 1-6 alkyl substituted with poly(alkylene oxide) and / or the group described for R 1 ; Each R 3 and R 4 are independently selected from C 1-10 alkyl, C 6-10 aryl, C 7-10 alkylaryl or C 1-6 alkyl substituted with poly(alkylene oxide); Each R 5 is independently a hydrolysable group such as C 1-6 alkoxy, acetoxy, alkenyloxy or ketonyloxy; Each R 6 is independently selected from C 1-6 alkyl; z is 0 or an integer from 1 - 2; x is an integer of at least 2; and y is an integer of at least 2.

11. The method according to any one of claims 1 to 10, wherein The polysiloxane-based binder accounts for at least 50 wt% of the polysiloxane-based coating composition relative to the total weight of the polysiloxane-based coating composition.

12. The method according to any one of claims 1 to 11, wherein The coating system is applied to a substrate, such as a marine substrate.

13. The method according to any one of claims 1 to 12, wherein, The coating system further comprises at least one adhesion promoting layer and / or at least one epoxy primer layer.

14. The method according to any one of claims 1 to 13, wherein, The crosslinking agent is a silicone compound represented by the general formula (I) shown below, a partial hydrolysis-condensation product thereof, or a mixture of both: R d -Si-K 4-d (I) wherein, Each R is independently selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, a group substituted with poly(alkylene oxide) or a structure (O-(CR D 2) r’ ) r1’ -(O-(CR D 2) s’ ) s1’ -(Si(R PP )2-O) t’ -Si(R PP )3 of a polysiloxane-substituted C 1-6 alkyl; wherein r', r1', s' and s1' are integers from 0 to 10, Each R D is independently selected from H or C 1-4 alkyl Each R PP is independently selected from C 1-10 alkyl, C 6-10 aryl, C 7-10 alkylaryl and t' is an integer from 1 to 50; each K is independently selected from hydrolyzable groups, such as alkoxy groups; and d is 0, 1 or 2, more preferably 0 or 1; or wherein the crosslinking agent is a double crosslinking agent of formula (II): wherein LL is independently selected from unsubstituted or substituted monovalent hydrocarbon groups of 1 to 6 carbon atoms; each M is independently selected from hydrolyzable groups, such as alkoxy groups; a is 0, 1 or 2, preferably 0 or 1; b is an integer from 1 to 6; and Fn is an amine, epoxy group, glycidyl ether, isocyanate or sulfur group.

15. The method according to any one of claims 1 to 14, wherein, The crosslinking agent accounts for 2.0 to 8.0 wt% of the polysiloxane-based coating composition.

16. The method according to any one of claims 1 to 15, wherein The polysiloxane-based coating composition of the first coating contains the same crosslinking agent, binder, additive oil and biocide as the polysiloxane-based coating composition of the second layer.

17. The method according to any one of claims 1 to 15, wherein The polysiloxane-based coating composition of the first coating contains the same crosslinking agent, binder, additive oil and biocide as the polysiloxane-based coating composition of the second layer, and contains the same amounts of crosslinking agent, binder, additive oil and biocide as the polysiloxane-based coating composition of the second layer.

18. The method according to any one of claims 1 to 15, wherein, The polysiloxane-based coating composition of the first coating is the same as the polysiloxane-based coating composition of the second layer.

Images