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Title:
AQUEOUS COATING COMPOSITION
Document Type and Number:
WIPO Patent Application WO/2019/060614
Kind Code:
A1
Abstract:
An aqueous coating composition is disclosed. The aqueous coating composition comprises a water-based resin binder, at least one surfactant able to disperse the resin binder in an aqueous phase, and a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition. The active content of the emulsion composition is 2 weight % or more of the aqueous coating composition. The aqueous coating composition has reduced surfactant leaching.

Inventors:
LEGER, Pierre (Rue Jules BordetParc Industriel Zone C, 7180 Seneffe, Seneffe, BE)
Application Number:
US2018/052051
Publication Date:
March 28, 2019
Filing Date:
September 20, 2018
Export Citation:
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Assignee:
DOW SILICONES CORPORATION (2200 W. Salzburg Road, P.O. Box 994Midland, MI, 48686-0994, US)
International Classes:
C08F230/08; C08F283/12; C08F290/06; C09D5/02; C09D7/65; C09D133/04; C09D143/04; C09D151/08; C09D183/10
Foreign References:
EP1006165A22000-06-07
JP2001192424A2001-07-17
US20020120039A12002-08-29
EP1095953A22001-05-02
Attorney, Agent or Firm:
ISTVAN-MITCHELL, Wyatt, J. et al. (900 Fifth Third Center, 111 Lyon Street NWGrand Rapids, MI, 49503, US)
Download PDF:
Claims:
CLAIMS

What is claimed is: 1. An aqueous coating composition comprising:

(A) a water-based resin binder;

(B) at least one surfactant; and

(C) a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition;

wherein the active content of the carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition is 2.0 weight % or more of the aqueous coating composition. 2. The aqueous coating composition of claim 1, wherein component (A) includes at least one acrylic resin binder. 3. The aqueous coating composition of claim 2, wherein the acrylic resin binder is characterized by self-cross-linkable acrylic resin having a Tg ranging from 10 to 35 °C. 4. The aqueous coating composition of any one of the preceding claims, wherein component (B) is an anionic or non-ionic surfactant. 5. The aqueous coating composition of any one of the preceding claims, wherein component (C) is obtainable or obtained by the emulsion polymerization of:

(a) a vinyl monomer;

(b) a carbosiloxane dendrimer that contains a radically polymerizable organic group of the formula:

wherein Y is a radically polymerizable organic group, R1 is C1 to C10 alkyl or aryl, and X1 is the silylalkyl group with the following formula when superscript i = 1:

wherein R1 is defined as above; R2 is C2 to C10 alkylene; R3 is C1 to C10 alkyl; Xi+1 is selected from the group consisting of hydrogen, C1 to C10 alkyl, aryl, and the above-defined silylalkyl group; superscript i is an integer of from 1 to 10 that specifies the generation of said silylalkyl group; and ai is an integer from 0 to 3,

and wherein the weight ratio of (a) : (b) is from about 0 : 100 to 99.9 : 0.1;

(c) a surfactant, at from 0.01 to 20 weight parts for each 100 weight parts of the total of components (a) and (b); and

(d) a radical polymerization initiator, at from 0.01 to 20 weight parts for each 100 weight parts of the total of components (a) and (b). 6 The aqueous coating composition of any one of the preceding claims, wherein component (C) is able to form a film or coating. 7. The aqueous coating composition of any one of the preceding claims, wherein the active content of the carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition is 2.5 weight % or more of the aqueous coating composition. 8. A use of a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition comprising a carbosiloxane dendrimer-grafted vinyl copolymer as a water-based paint additive. 9. The use as claimed in claim 8, to decrease the surfactant leaching of an aqueous coating composition. 10. The use as claimed in claim 8, to increase the stain resistance of an aqueous coating composition. 11. A method of decreasing the surfactant leaching of an aqueous coating composition comprising at least the step of:

adding a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition comprising carbosiloxane dendrimer-grafted vinyl copolymer in 2.0 weight % or more of its active content to the aqueous coating composition. 12. A method of increasing the stain resistance of an aqueous coating composition comprising at least the step of:

adding a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition comprising carbosiloxane dendrimer-grafted vinyl copolymer in 2.0 weight % or more of its active content to the aqueous coating composition.

Description:
AQUEOUS COATING COMPOSITION

Cross-Reference to Related Applications

[0001] This application claims priority to and all advantages of GB Patent Appl. No.1715402.2 filed on 22 September 2017, the content of which is hereby incorporated by reference.

Technical Field

[0002] The present invention relates to an aqueous coating composition such as a water- based paint, using a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition. The present invention further relates to the use of a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition as a water-based paint additive, particularly but not exclusively to decrease the surfactant leaching of an aqueous coating composition.

Background Art

[0003] Various silicone-grafted vinyl copolymer emulsion compositions comprising a vinyl monomer and a carbosiloxane dendrimer are known from EP 1 095 953 A2. The emulsion composition is characterized by excellent storage stability and by the ability to form a film or coating that exhibits an excellent water repellency.

[0004] Also known in the art are various carbosiloxane dendrimer non-emulsion additives for a coating agent which exhibit a compatibility with resins, and which comprise a co-polymer that contains a hydroxyl group and a group having a carbosiloxane dendrimer structure, as set out in WO 2012/091178 A1.

[0005] However, problems still occur in relation to the leaching of surfactants in aqueous coating compositions such as water-based paint. Surfactant leaching is sometimes called a ‘snail trail of resistance’ or just‘snail trail’. Such leaching occurs on both interior and exterior walls, where vertical marks are seen on the paint, and which are usually sufficiently visually unsightly as to require re-painting. Typically the marks occur as paint is drying, and the atmosphere is cold, or is humid, or there is a heavy dew fall, or there is rain. Surfactants in the dried or drying paint migrate (or leach) to the wall’s surface towards the wetness or dampness, and then dry on the surface. The migration of salts causes the vertical marks or streaks, which then typically follow a gravitational direction to form vertical marks.

Summary to the Invention

Technical Problem

[0006] An object of the present invention is to provide an aqueous coating composition with reduced surfactant leaching. A further object of the present invention is to provide a use and a method of decreasing the surfactant leaching of an aqueous coating composition.

[0007] Another object of the present invention is to provide an aqueous coating composition with improved stain resistance. A further object of the present invention is to provide a use and a method of increasing the stain resistance of an aqueous coating composition. Solution to Problem

[0008] The present inventors achieved the present invention as a result of extensive investigations directed to solving the problem described above. The problem is solved by an aqueous coating composition comprising:

(A) a water-based resin binder;

(B) at least one surfactant; and

(C) a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition;

wherein the active content of the carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition is 2.0 weight % or more of the aqueous coating composition.

[0009] The problem is also solved by the use of various carbosiloxane dendrimer-grafted vinyl copolymer emulsion compositions comprising a carbosiloxane dendrimer-grafted vinyl copolymer, as a water-based paint additive.

[0010] The problem is also solved by a method of decreasing the surfactant leaching, or of increasing the stain resistance, of an aqueous coating composition, comprising at least the step of adding a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition comprising 2.0 weight % or more active content of carbosiloxane dendrimer-grafted vinyl copolymer to the aqueous coating composition.

Detailed Description of the Invention

[0011] The aqueous coating composition of the present invention is described in detail below.

[0012] The aqueous coating composition may comprise any paint or other coating agent which is‘water-based’, which includes one or more of the group comprising: organic binder emulsion (typically acrylic or styrene acrylic copolymer), dispersants, fillers and pigments, defoamers, thickeners, coalescent solvent, water, biocides, pH modifiers, etc. Water-based paints are increasingly preferred to organic solvent-based paint to avoid toxicity issues. Water- based paints can also be fast drying, have easier application, and allow easier cleaning of equipment.

[0013] The aqueous coating composition according to the present invention characteristically contains component (A) a water-based resin binder. The water-based resin binder may be one or more of the group comprising: pure acrylic emulsions, styrene acrylic copolymer emulsions. Binders include synthetic or natural resins such as alkyds, acrylics, vinyl-acrylics, vinyl acetate/ethylene (VAE) or siloxanes. The water-based binder can be exemplified by acrylic resin binders, which may comprise less than 0.5wt% alkyl phenol ethoxylates (and in some embodiments substantially free from alkyl phenol ethoxylates). The acrylic resin binders may also be self-cross-linking. The acrylic resin binders may have a solids content of 40- 55wt%, alternatively 40-50wt%, alternatively 43-47wt%. The acrylic resin binders may pH of 7-11, alternatively 8-10. The minimum film formation temperature may be -5-20°C, alternatively 0-19°C. In various embodiments, component (A) is exemplified to be a self-cross- linkable acrylic resin having a glass transition temperature (Tg) ranging from 10 to 35 °C, having a hydrophobic property derived from having a higher content for hydrophobic acrylate monomers. Such a water-based resin binder can be emulsified with any type of surfactants or combinations thereof. With respect to stability and solubility in relationship with component (C) in the composition of the present invention, anionic surfactants are utilized in certain embodiments to emulsify a self-cross-linkable resin into water phase. Suitable acrylic resin binders include SG-380 and Primal SF-016 (both Dow Chemical, Midland, USA). Primal SF- 016 contains a higher amount of surfactant than SG-380.

[0014] The aqueous coating composition according to the present invention characteristically contains component (B) at least one surfactant. The at least one surfactant may be for dispersing pigments in the composition. The component (B) may be derived from dispersant or emulsifier for said component (A) in aqueous raw resin/paint composition, or derived from polymerization reaction material for component (A) or component (C). Needless to say, the component (B) can be independently blended to the inventive composition apart from said component (A) or component (C).

[0015] The at least one surfactant may be anionic or nonionic. Anionic surfactants include alkyl sulfates (sodium Lauryl sulfate), Fatty Alcohol Ether Sulfates (FAES), and Alkyl Phenol Ether Sulfates (APES). In certain embodiments, the alkyl sulfate may be sodium lauryl sulfate. Nonionic surfactants include polyethoxylates, such as ethoxylated alkyl polyethylene glycol ethers.

[0016] At least one surfactant able to disperse pigment may be neutralized acid copolymers, polycarboxylic acids, polyphosphates, modified fatty acid derivatives, or amine neutralized phosphoric acid ester.

[0017] The surfactant can be exemplified by a polycarboxylate dispersant, such as OROTAN™ 731 A ER (Dow Chemical, Midland, USA)

[0018] The aqueous coating composition according to the present invention characteristically contains component (C) a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition. Various carbosiloxane dendrimer-grafted vinyl copolymer emulsion compositions are known in the art. A range of carbosiloxane dendrimer-grafted vinyl copolymer emulsion compositions are defined in EP 1 095 953 A2, which is incorporated herein by way of reference, and which describes the emulsion polymerization of:

(a) a vinyl monomer;

(b) a carbosiloxane dendrimer as defined herein,

(c) a surfactant; and

(d) a radical polymerization initiator. [0019] Optionally, the vinyl monomer (a) should contain a radically polymerizable vinyl group, but the type and properties of this monomer are not otherwise critical. Vinyl monomer (a) can be exemplified by: lower alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, and isopropyl acrylate; lower alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate; higher acrylates such as n- butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2- ethylhexyl acrylate, octyl acrylate, lauryl acrylate, and stearyl acrylate; higher methacrylates such as n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, and stearyl methacrylate; the vinyl esters of lower aliphatic acids, such as vinyl acetate and vinyl propionate; the vinyl esters of higher aliphatic acids, such as vinyl butyrate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl laurate, and vinyl stearate; aromatic vinyl monomers such as styrene, vinyl toluene, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, and vinyl pyrrolidone; amino-functional vinyl monomers such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate; amide-functional vinyl monomers such as acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, isobutoxymethoxyacrylamide, N,N-dimethylacrylamide, methacrylamide, N- methylolmethacrylamide, N-methoxymethylmethacrylamide, isobutoxymethoxymethacrylamide, and N,N-dimethylmethacrylamide; hydroxyl-functional vinyl monomers such as 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxybutyl methacrylate, and 2-hydroxypropyl methacrylate; fluorinated vinyl monomers such as trifluoropropyl acrylate, perfluorobutylethyl acrylate, perfluorooctylethyl acrylate, trifluoropropyl methacrylate, perfluorobutylethyl methacrylate, and perfluorooctylethyl methacrylate; epoxy-functional vinyl monomers such as glycidyl acrylate, 3,4-epoxycyclohexylmethyl acrylate, glycidyl methacrylate, and 3,4- epoxycyclohexylmethyl methacrylate; ether linkage-containing vinyl monomers such as tetrahydrofurfuryl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, polyethylene glycol acrylate, polypropylene glycol monoacrylate, hydroxybutyl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether, tetrahydrofurfuryl methacrylate, butoxyethyl methacrylate, ethoxydiethylene glycol methacrylate, polyethylene glycol methacrylate, polypropylene glycol monomethacrylate; alkoxysilanes that contain a radically polymerizable unsaturated group, such as

unsaturated group-functionalized silicone compounds such as organopolysiloxane (branched or straight-chain) bearing an acryl or methacryl group at a single terminal and polydimethylsiloxane bearing a styryl group at a single terminal; butadiene; vinyl chloride; vinylidene chloride; acrylonitrile and methacrylonitrile; dibutyl fumarate; maleic anhydride; dodecylsuccinic anhydride; radically polymerizable unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, and maleic acid, as well as their alkali metal salts, ammonium salts, and organic amine salts; radically polymerizable unsaturated monomers that contain a sulfonic acid residue, e.g., styrenesulfonic acid, as well as their alkali metal salts, ammonium salts, and organic amine salts; quaternary ammonium salts that are derived from (meth)acrylic acid, such as 2-hydroxy- 3-methacryloxypropyltrimethylammonium chloride; and the methacrylate esters of alcohols that contain a tertiary amine group, such as the diethylamine ester of methacrylic acid, as well as the quaternary ammonium salts thereof. In certain embodiments, preferred among the preceding are acrylate ester monomers, methacrylate ester monomers, and styrene monomers.

[0020] Also usable are multifunctional vinyl monomers, as can be exemplified by acryloyl-or methacryloyl-functional monomers such as trimethylolpropane triacrylate, pentaerythritol triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane trioxyethylacrylate, tris(2-hydroxyethyl)isocyanurate diacrylate, tris(2- hydroxyethyl)isocyanurate triacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trioxyethylmethacrylate, tris(2-hydroxyethyl)isocyanurate dimethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, the diacrylates and dimethacrylates of diols that are the adducts of ethylene oxide or propylene oxide on bisphenol A, and the diacrylates and dimethacrylates of diols that are the adducts of ethylene oxide or propylene oxide on hydrogenated bisphenol A. Usable multifunctional vinyl monomers can also be exemplified by triethylene glycol divinyl ether, divinylbenzene, and unsaturated group-functional silicone compounds such as polydimethylsiloxane endblocked at both terminals by the styryl group and polydimethylsiloxane endblocked at both terminals by methacryloxypropyl.

[0021] Considering the above-listed vinyl monomers, the use in particular of vinyl monomer bearing a crosslinkable functional group makes it possible for the silicone-grafted vinyl copolymer to undergo crosslinking upon removal of the water from the composition after emulsion polymerization. The crosslinkable functional group under consideration can be, for example, an amino group, epoxy group, tetrahydrofurfuryl group, carboxyl group, hydroxyl group, blocked isocyanate group, or any of various silyl groups, e.g., halogenated silyl, alkoxysilyl, and acetoxysilyl. This crosslinking serves to improve the durability and solvent resistance of the silicone-grafted vinyl copolymer. The crosslinking can be of the self- crosslinking type or may be effected using a crosslinker, e.g., melamine, multifunctional epoxy, or multifunctional isocyanate. A crosslinking catalyst can also be used as necessary. Since in some cases the aforementioned crosslinkable functional groups can be hydrolyzed by water, it may be necessary to effect emulsification-using techniques known in the art so as to avoid their hydrolysis. Moreover, an additional stabilization of the composition of the present invention can be achieved by using hydrophilic vinyl monomer for a portion of component (A), said hydrophilic vinyl monomer being exemplified by acrylic acid, methacrylic acid, 2- hydroxyethyl acrylate, dimethylaminoethyl acrylate, 2-hydroxyethyl methacrylate, and dimethylaminoethyl methacrylate.

[0022] Optionally, the carbosiloxane dendrimer component (b) bears a radically polymerizable organic group having the following general formula:

wherein Y in this general formula is a radically polymerizable organic group and can be, for example, C 2 to C 10 alkenyl or an acryl-, methacryl-, or styryl-functional organic group as defined by the following general formulas.

[0023] R 4 and R 6 in these formulas are hydrogen or methyl; R 5 and R 8 are C 1 to C 10 alkylene; R 7 is C 1 to C 10 alkyl; subscript b is an integer from 0 to 4; and subscript c is 0 or 1. These radically polymerizable organic groups can be exemplified by acryloxymethyl, 3- acryloxypropyl, methacryloxymethyl, 3-methacryloxypropyl, 4-vinylphenyl, 3-vinylphenyl, 4-(2- propenyl)phenyl, 3-(2-propenyl)phenyl, 2-(4-vinylphenyl)ethyl, 2-(3-vinylphenyl)ethyl, vinyl, allyl, methallyl, and 5-hexenyl. R 1 in the preceding general formula for the carbosiloxane dendrimer (B) is C 1 to C 10 alkyl or aryl. The alkyl encompassed by R 1 can be exemplified by methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl, cyclopentyl, and cyclohexyl. The aryl encompassed by R 1 can be exemplified by phenyl and naphthyl. In certain embodiments, methyl and phenyl are preferred for R 1 , and methyl is particularly preferred. X 1 is the silylalkyl group with the following formula when subscri t i = 1

[0024] R 1 in the preceding formula is defined as above. R 2 in the preceding formula represents C 2 to C 10 alkylene and can be exemplified by ethylene, propylene, and butylene. R 3 in the preceding formula is C 1 to C 10 alkyl, for example, methyl, ethyl, propyl, or butyl. X i+1 is selected from the group consisting of hydrogen, C 1 to C 10 alkyl, aryl, and the above- defined silylalkyl group. Subscript a i is an integer from 0 to 3. Superscript i is an integer with a value from 1 to 10 that specifies the generation of said silylalkyl group, i.e., that indicates the number of repetitions of this silylalkyl group. Thus, the carbosiloxane dendrimer (b) has the following general formula when the number of generations i is 1:

(in the preceding formula, Y, R 1 , R 2 , and R 3 are defined as above; R 12 is hydrogen or is defined as for R 1 ; subscript a 1 is defined as for a i ; and the average of the sum of the a 1 values in each molecule is from 0 to 7). The carbosiloxane dendrimer (B) has the following general formula when the number of generations i is 2:

(in the preceding formula, Y, R 1 , R 2 , R 3 , and R 12 are defined as above; subscripts a 1 and a 2 are defined as for a i ; and the average of the sum of the a 1 and a 2 values in each molecule is from 0 to 25). The carbosiloxane dendrimer (b) has the following general formula when the number of generations i is 3:

(in the preceding formula, Y, R 1 , R 2 , R 3 , and R 12 are defined as above; subscripts a 1 , a 2 and a 3 are defined as for a i ; and the average of the sum of the a 1 , a 2 , and a 3 values in each molecule is from 0 to 79).

[0025] Compounds with the following average compositional formulas are examples of component (b), i.e., carbosiloxane dendrimer functionalized with a radically polymerizable organic group:

[0026] The carbosiloxane dendrimer described above can be synthesized, for example, by the method described in Japanese Patent Application Laid Open (Kokai) Number Hei 11-1530 (1,530/1999). In this method, the carbosiloxane dendrimer is synthesized by running a hydrosilylation reaction between an alkenyl-functional organosilicon compound and an SiH- functional silicon compound with the following general formula:

in which R 1 and Y are defined as above. The silicon compound with this formula can be exemplified by 3-methacryloxypropyltris(dimethylsiloxy)silane, 3- acryloxypropyltris(dimethylsiloxy)silane, and 4-vinylphenyltris(dimethylsiloxy)silane. The alkenyl-functional organosilicon compound referenced above can be exemplified by vinyltris(trimethylsiloxy)silane, vinyltris(dimethylphenylsiloxy)silane, and 5- hexenyltris(trimethylsiloxy)silane. In general, this hydrosilylation reaction is run in the presence of a transition metal catalyst, e.g., chloroplatinic acid or a platinum-vinylsiloxane complex.

[0027] Optionally, the component (a) : component (b) polymerization ratio should be in the range from 0 : 100 to 99.9 : 0.1 as the component (a) : component (b) weight ratio, and alternatively is from 50 : 50 to 95 : 5, and alternatively is from 60 : 40 to 90 : 10. The characteristic properties of the carbosiloxane dendrimer structure do not appear when the component (b) blending ratio is below 0.1.

[0028] Optionally, the surfactant (c) may be one or more surfactants typically used in the emulsion-polymerization of vinyl polymers, and the choice of such is not critical. It may be e.g., an anionic surfactant, nonionic surfactant, cationic surfactant, or amphoteric surfactant. Anionic surfactants are exemplified by sodium oleate, sodium stearate, the sodium salt of dodecylbenzenesulfonic acid, salts of alkylsulfate, and the sodium salt of polyoxyethylenealkylethersulfonic acid. Cationic surfactants are exemplified by quaternary ammonium salts such as dodecyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octyldimethylbenzylammonium hydroxide, decyldimethylbenzylammonium hydroxide, didodecyldimethylbenzylammonium hydroxide, dioctadecyldimethylbenzylammonium hydroxide, tallow trimethylammonium hydroxide, and coconut oil-trimethylammonium hydroxide. Nonionic surfactants are exemplified by polyoxyethylene laurylether, polyoxyethylene stearylether, polyoxyethylene nonylphenolether, polyoxyethylene monostearate, sorbitan monostearate, and polyoxyethylene sorbitan monostearate. Amphoteric surfactants are exemplified by amino acid-type surfactants and betaine-type surfactants. In certain embodiments, anionic surfactants, cationic surfactants or combinations of these surfactants are preferred. In various embodiments, the surfactant (c) is a radically polymerizable surfactant which enhances the water-resistance of films formed from the emulsion composition. In general, the radically polymerizable surfactant (c) should exhibit surfactancy and should be capable of undergoing radical polymerization, but its character is not otherwise critical. This radically polymerizable surfactant (c) may be an anionic, nonionic, or cationic surfactant.

[0029] Optionally, the anionic types of radically polymerizable surfactant (c) may be exemplified by compounds with the following structures.

[0030] Acrylic types of anionic surfactant:

[0031] In the preceding structures, R is hydrogen or methyl,“M” denotes alkali metal,“AO” denotes alkylene oxide, and subscript x is an integer from 1 to 50. [0032] Allylic types of radically polymerizable anionic surfactant:

[0033] In the preceding structures, R is hydrogen or methyl,“M” denotes alkali metal,“AO” denotes alkylene oxide, and subscript x is an integer from 1 to 50.

[0034] Maleic acid types of radically polymerizable anionic surfactant:

[0035] R 1 in the preceding structures is hydrogen or methyl, R 2 denotes alkylene,“M” denotes alkali metal,“AO” denotes alkylene oxide, and subscript x is an integer from 1 to 50.

[0036] Itaconic acid types of radically polymerizable anionic surfactant:

[0037] In the preceding structures, R is hydrogen or methyl,“M” denotes alkali metal, and subscript x is an integer from 1 to 50.

[0038] The nonionic types of the radically polymerizable surfactant (c) can be exemplified by the following compounds.

[0039] Acrylic types of radically polymerizable nonionic surfactant:

[0040] In the preceding structures, R is hydrogen or methyl,“AO” denotes alkylene oxide, “EO” denotes ethylene oxide,“PO” denotes propylene oxide, and subscript x is an integer from 1 to 50.

[0041] Allylic types of radically polymerizable nonionic surfactant:

[0042] In the preceding structures, R is hydrogen or methyl,“AO” denotes alkylene oxide, and subscript x is an integer from 1 to 50.

[0043] Maleic acid types of radically polymerizable nonionic surfactant:

[0044] Itaconic acid types of radically polymerizable nonionic surfactant:

[0045] In the preceding structures, R is hydrogen or methyl,“AO” denotes alkylene oxide, and subscript x is an integer from 1 to 50.

[0046] The cationic types of the radically polymerizable surfactant (C) can be exemplified by the following compounds. [0047] Acrylic types of radically polymerizable cationic surfactant:

[0048] In the preceding structures, R is hydrogen or methyl, and“X” is a halogen atom.

[0049] Allylic types of radically polymerizable cationic surfactant:

[0050] In the preceding structures, R is hydrogen or methyl, and“X” is a halogen atom.

[0051] In certain embodiments, the following surfactants are preferred from among those listed above:

[0052] Component (c) can take the form of only a single surfactant or can be a combination of two or more surfactants. Component (c) may be used at from 0.01 to 20 weight parts, and alternatively at from 0.1 to 10 weight parts, in each case per 100 weight parts of the total amount of components (a) and (b).

[0053] Optionally, the radical polymerization initiator (d) may be selected from the radical polymerization initiators generally used for the emulsion polymerization of vinyl polymers, but its type and nature are not otherwise critical. Component (d) can be exemplified by inorganic persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; organoperoxides such as tert-butyl peroxymaleic acid, succinic acid peroxide, and tert-butyl hydroperoxide; water-soluble azo-type radical initiators such as 2,2'-azobis(2-(N- benzylamidino)propane)hydrochloride, 2,2'-azobis(2-(N-2- hydroxyethylamidino)propane)hydrochloride, and 2,2'-azobis(2-methyl-N- hydroxyethyl)propionamide; oil-soluble azo-type radical initiators such as 2,2'- azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1-azobis-1- cyclohexanecarbonitrile, dimethyl 2,2'-azobisisobutyrate, and 4,4'-azobis-4-cyanovaleric acid; and oil-soluble peroxides such as lauroyl peroxide, benzoyl peroxide, dicumyl peroxide, cyclohexanone peroxide, di-n-propyl peroxydicarbonate, and tert-butyl peroxypivalate. When a water-soluble radical initiator is used in the execution of the present invention, it may be mixed with the other components after their antecedent emulsification. Component (d) may be used at from 0.01 to 20 weight parts, and alternatively used at from 0.1 to 10 weight parts, in each case per 100 weight parts of the total amount of components (a) and (b).

[0054] The emulsion compositions of component (C) may be obtained by combining from 0.01 to 20 weight parts radically polymerizable surfactant (c) and from 0.01 to 20 weight parts radical polymerization initiator (d) with 100 weight parts of the mixture of vinyl monomer (a) and carbosiloxane dendrimer (b), producing an emulsified dispersion therefrom in an aqueous medium, and effecting emulsion polymerization therein. As stated herein above, in various embodiments the component (a) : component (b) weight ratio is in the range from 60 : 40 to 90 : 10. In certain embodiments, component (a) is preferred to be a mixture of two or more vinyl monomers. By selecting component (a) as a mixture including an alkyl-modified vinyl monomer in higher content, the flexibility and Tg for the so-obtained copolymer can also be controlled. Components (a) to (d) may be emulsified and dispersed in combination with each other, or the radical polymerization initiator (d) may be added after the antecedent emulsification and dispersion process.

[0055] The emulsified dispersion can be prepared using the usual emulsification devices, for example, a colloid mill or a homogenizer. Polymerization may be carried out for about 2 to 8 hours after preheating the reaction system to 50 to 90°C. This polymerization can be run by dropwise addition of the emulsified dispersion or after introducing the entire emulsified dispersion in one lot. In certain embodiments, the former technique is preferred because it facilitates temperature control. A chain transfer agent generally known for use in emulsion polymerizations may also be used in the present invention. The chain transfer agent can be exemplified by mercaptan compounds such as 2-mercaptoethanol, butyl mercaptan, n- dodecyl mercaptan, 3-mercaptopropyltrimethoxysilane, and mercaptopropyl-functional polydimethylsiloxanes; by halogen compounds such as methylene chloride, chloroform, carbon tetrachloride, butyl bromide, and 3-chloropropyltrimethoxysilane; and by alpha- methylstyrene dimer. Surfactant lacking reactive functionality may be used― within a range that does not impair the characteristic features of the inventive composition― in combination with the surfactant (c).

[0056] The post-polymerization particle size of the emulsion is not critical, but viewed from the standpoints of storage stability and preventing the appearance of aggregates in various embodiments is no greater than 1.0 µm, alternatively no greater than 0.5 µm, alternatively no greater than 0.3 µm. A thickener can be added and/or the specific gravity can be adjusted when the particle size is to be made 1.0 µm or above. In various embodiments, the solids content of the inventive composition is in the range from 15 to 60 weight% based on productivity and handling considerations.

[0057] The obtained carbosiloxane dendrimer-grafted vinyl copolymer in this emulsion composition generally has at least some flexibility derived from its Tg (generally measured by DMA method) in the range 40 to 80°C, and an optional molecular weight (as determined by GPC-THF) in the range from 1 million to 5 million. Suitable commercially available emulsion products include Dow Corning® FA 4103 Silicone Acrylate Emulsion and similar products, which can be utilized. In various embodiments, the carbosiloxane dendrimer-grafted vinyl copolymer comprises, is, or may be referred to as a carboxysiloxane dendrimer-grafted vinyl copolymer.

[0058] Additives such as colorants, stabilizers, fats, oils, waxes, and fillers can be added to the aqueous coating compositions of the present invention as needed.

[0059] A characteristic feature of the inventive aqueous coating compositions of the present invention are a high loading of active content of the carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition, in particular being above 2.0 weight %, such as being 2.5 weight % or more, 3 weight % or more, 3.5 weight % or more, 4 weight % or more, 4.5 weight % or more, 5 weight % or more, 5.5 weight % or more, 6 weight % or more, 7 weight % or more, 8 weight % or more, 9 weight % or more, or 10 weight % or more. In some embodiments, the active content may be in the range 2.0 to 20 weight % or 2.0 to 15 weight % or 2.0 to 15 weight %. Any of these ranges represent a surprising high loading of the dendrimer-grafted copolymer, whose presence may hinder the migration of water-soluble salts as the aqueous coating composition is drying.

[0060] The term active content as used herein relates to the active part of the emulsion composition, being the monomer content in the emulsion composition, typically accounting for 30% of the final composition. This is the same as the solid content of the emulsion composition. One or more of the surfactants could also be defined as a‘solid component’ of the emulsion and can be separated with co-polymer by removing water, to clarify the effect of this invention, it is needed to distinguish all surfactants (in raw paints and from emulsion) from co-polymer content. The co-polymer content can be calculated by the amount of monomers in emulsion polymerization.

[0061] Thus, the present invention further provides a use of a carbosiloxane dendrimer- grafted vinyl copolymer emulsion composition, in particular to decrease the surfactant leaching of an aqueous coating composition, especially as it dries or is drying.

[0062] Surfactant leaching is considered to be the mechanism through which water soluble components within the coating moves through the surface of a paint. The process usually occurs over a period of time, such as weeks, after initial drying of an aqueous coating composition is applied to a surface, and is possibly washed by rain, although it can be accelerated under certain atmospheric conditions (often in spring and in autumn time). In one example, the formation of condensation on a‘freshly painted’ exterior facade due to temperature falling below dew point will cause surfactants to migrate to surface. When the condensation subsequently dries, the surfactants are deposited on the surface of the paint, causing shiny streaks or discoloration. Surfactant leaching is visually more apparent in dark, ultra-deep colors, although it also happens for lighter colors, even for white paint, when the exudate has a tan color.

[0063] The present invention further provides a use of a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition to increase the water contact angle of an aqueous coating composition.

[0064] The amount of carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition used in an aqueous coating composition may be above 2 weight % active content, such as being 2.5 weight % or more, 3 weight % or more, 3.5 weight % or more, 4 weight % or more, 4.5 weight % or more, 5 weight % or more, 5.5 weight % or more, 6 weight % or more, 7 weight % or more, 8 weight % or more, 9 weight % or more, or 10 weight % or more. In some embodiments, the amount may be in the range 2.0 to 20 weight %.

[0065] The present invention also provides a method of decreasing the surfactant leaching of an aqueous coating composition comprising at least the step of: adding 2 weight % or more active content of a carbosiloxane dendrimer-grafted vinyl copolymer emulsion composition comprising carbosiloxane dendrimer-grafted vinyl copolymer to the aqueous coating composition. The range 2 weight % or more may be 2.5 weight % or more, 3 weight % or more, 3.5 weight % or more, 4 weight % or more, 4.5 weight % or more, 5 weight % or more, 5.5 weight % or more, 6 weight % or more, 7 weight % or more, 8 weight % or more, 9 weight % or more, or 10 weight % or more. In some embodiments, the active content may be in the range 2.0 to 20 weight %.

[0066] It is also known that paint and coating surfaces can change following exposure to water, in particular exposure to rain or dew or steam, and a further characteristic of the present invention is to reduce or minimize any changes at paint surfaces following exposure to water or water vapor, which can be measured by contact angle.

EXAMPLES

[0067] This invention is explained in greater detail below through working examples. Parts in the examples denote weight parts, and any percentages are by weight. The following methods were used to measure and evaluate the properties of the emulsion compositions and coatings.

[0068] Several loadings of a commercial Emulsion P1 carbosiloxane dendrimer-grafted vinyl copolymer emulsion, characterized by a Tg of 60°C and a molecular weight ranging from 1 million to 5 million, a carbosiloxane monomer composition of 50% of other acrylic monomer, were added to a general paint composition having the following composition:

filler (blend calcium carbonate, silica, talc– PVC ca 70%);

hydrophobic dispersant (ca 1.5%, i.e., a surfactant such as OROTAN™ 731);

thickener (cellulosic i.e., CELLOSIZE™ QP4400, acrylic, i.e., ACRYSOL™ RM-935); biocide; and silicone antifoam.

[0069] The loadings were defined as either 10%, 5%, 2.5% and 1.25% active content The active content percentages were based on the polymerized monomer fraction of the carbosiloxane dendrimer-grafted vinyl copolymer emulsion, for example 30% when residual composition being water used as dispersion medium during the emulsion polymerization process. Thus, 1.25%‘active content’ corresponds to 4.17% of the Emulsion P1 as supplied, and once mixed with the paint composition.

[0070] The emulsion compositions were judged against;

(i) a‘Non-silicone comparison’, being the same general paint composition listed above without any copolymer emulsion; and

(ii) a‘Silicone comparison’, being the same general paint composition listed above and a mixture comprising 4% SILRES® BS45 and 1% SILRES® BS1306 (both Walker Chemie AG, Germany)

[0071] Snail trail and hydrophobic properties were evaluated following to experimental methods described below.

Experimental

[0072] The snail trail test was based on painting a surface, allowing it to dry for 24 hours at room temperature and 50% RH, followed by applying 2µl drops of liquid H 2 O to the painted surface, leaving them for 30 minutes, removing the H 2 O by lifting up panels vertically and then evaluating the samples. The water contact angle (WCA) test was based on visual appearance of the drops of H 2 O after 0 seconds and 60 seconds on the coatings. A 2µl drop of high purity water was applied to a test specimen surface using a liquid delivery system (100µl syringe). Images of the drop in contact with the substrate were captured by a video camera at specified time intervals following deposition.

[0073] The contact angle between the drop and the substrate at various time intervals following drop deposition were determined by image analysis techniques on the captured images (according to ASTM D5725). The equipment used was a VCA Optima XE from AST Products, Inc. The results are shown in Table 1 below (N: no trail appeared after water contact; Δ: slight trail was appeared; X: clear trail appeared and remained): Table 1

[0074] The evaluation scale used to assess the water contact angles results obtained is shown in Table 2 below.

Table 2

[0075] House hold stain resistance was evaluated by post-adding the carbosiloxane dendrimer-grafted vinyl copolymer emulsion to a‘Control’ formulation having the composition set out in Table 3 below. The carbosiloxane dendrimer-grafted vinyl copolymer emulsion was added at 2% emulsion solid content, or by using the carbosiloxane dendrimer-grafted vinyl copolymer emulsion as a‘Co-binder’, in a 60/40 dry ratio between the acrylic emulsion and the carbosiloxane dendrimer-grafted vinyl copolymer emulsion (i.e., replacing 40% of dry SG- 380 with Emulsion P1). The Control and Co-binder formulations are set out in Table 3 below (in parts by weight).

Table 3

[0076] Stain methods: Seven different household stains were applied to panels painted with each of the compositions mentioned below and then left for 30 minutes. The panels were then washed for 10 seconds under tap water. Each panel then received 20 strokes from a scrubbing machine with water. The panels were then evaluated visually and dE measurements (spectrophotometric change of color) were made (lower = better). Color change was measured using a BYK spectrophotometer 45/0 geometry Cielab equation D65 illuminant, conforming to ASTM D2244. The results are shown in Table 4 below. Compared with the acrylic emulsion alone, in general, the coating formulation comprising carbosiloxane dendrimer-grafted vinyl copolymer emulsion is lower in color change degree and show better stain proof performance, reflected by the lower color difference measured through dE.

Table 4

[0077] The terms“comprising” or“comprise” are used herein in their broadest sense to mean and encompass the notions of “including,”“include,”“consist(ing) essentially of,” and “consist(ing) of.” The use of“for example,”“e.g.,”“such as,” and“including” to list illustrative examples does not limit to only the listed examples. Thus,“for example” or“such as” means “for example, but not limited to” or“such as, but not limited to” and encompasses other similar or equivalent examples. The term“about” as used herein serves to reasonably encompass or describe minor variations in numerical values measured by instrumental analysis or as a result of sample handling. Such minor variations may be in the order of ±0-25, ±0-10, ±0-5, or ±0- 2.5, % of the numerical values. Further, The term“about” applies to both numerical values when associated with a range of values. Moreover, the term“about” may apply to numerical values even when not explicitly stated.

[0078] Generally, as used herein a hyphen“-” or dash“–” in a range of values is“to” or “through”; a“>” is“above” or“greater-than”; a“≥” is“at least” or“greater-than or equal to”; a “<” is“below” or“less-than”; and a“≤” is“at most” or“less-than or equal to.” On an individual basis, each of the aforementioned applications for patent, patents, and/or patent application publications, is expressly incorporated herein by reference in its entirety in one or more non- limiting embodiments.

[0079] It is to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, it is to be appreciated that different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.

[0080] It is also to be understood that any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range“of from 0.1 to 0.9” may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as“at least,”“greater than,”“less than,”“no more than,” and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of“at least 10” inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range“of from 1 to 9” includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

[0081] The present invention has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. The present invention may be practiced otherwise than as specifically described within the scope of the appended claims. The subject matter of all combinations of independent and dependent claims, both single and multiple dependent, is herein expressly contemplated.