Water-based coating composition

Abstract

The present invention generally relates to the field of crosslinkable aqueous vinyl polymer dispersions; a coating composition comprising said crosslinkable aqueous vinyl polymer dispersions; a paint formulation comprising said crosslinkable aqueous vinyl polymer dispersions; and an article coated with the coating composition or the paint formulation. In particular, the present invention provides an aqueous vinyl polymer dispersion PD comprising the following polymer: - 1) An aqueous dispersion of vinyl polymer P1 obtainable by free radical emulsion polymerization of a monomer mixture comprising the following: a) 5 to 20 wt% of acid-functional ethylenically unsaturated monomer M1 or its precursor; b) 5 to 25 wt% of an ethylenically unsaturated monomer M2 containing a polyethylene glycol or monoalkoxypolyethylene glycol portion; c) Nonionic ethylenically unsaturated monomer M3 other than M1 or M2, up to 90 wt%; d) 0 to 10 wt% of ethylenically unsaturated monomer M4 having functional groups for crosslinking after film formation; e) 0 to 10 wt% of one or more chain transfer agents CTA; Here, the sum of the wt% of M1+M2+M3+M4+CTA = 100 wt%; - 2) An aqueous dispersion or solution of vinyl polymer P2 obtainable by the following free radical copolymerization: a) 25 to 95 wt% of an ethylenically unsaturated monomer M5 selected from the group of N-vinylamides having the following general structure: (In the formula, R1 and R2 are C1 to C5 alkyls and can be connected to form a ring structure, preferably N-vinylpyrrolidone or N-vinylcaprolactam); b) 5 to 75 wt% of nonionic ethylenically unsaturated monomer M3' other than M5; c) 0 to 5 wt% of an ethylenically unsaturated monomer M4' having functional groups for crosslinking after film formation; d) 0 to 10 wt% of acid-functional ethylenically unsaturated monomer M1' or its precursor; e) 0 to 5 wt% of one or more chain transfer agents CTA'; Here, the sum of the wt% of M5+M3'+M4'+M1'+CTA' = 100 wt%; - 3) Film-forming vinyl polymer P3 in the form of an aqueous dispersion comprising the following: i) 20 to 60 wt% of water-soluble or water-dispersible crosslinkable vinyl oligomer OL obtained by emulsion polymerization of a monomer mixture comprising the following: 1) One or more acid-functional ethylenically unsaturated monomers M1"; 2) One or more ethylenically unsaturated monomers M4" having functional groups for crosslinking during film formation other than M1"; 3) One or more ethylenically unsaturated monomers M3" other than M1" and M2", and 5) Optionally, one or more chain transfer agent CTAs, and ii) 40 to 80 wt% of high molecular weight vinyl polymer P4 prepared by emulsion polymerization of a monomer mixture comprising the following in the presence of a water-soluble or water-dispersible crosslinkable vinyl oligomer OL: 1) Optionally one acid-functional ethylenically unsaturated monomer M1"'; 2) Optionally one or more ethylenically unsaturated monomers M4"' having functional groups for crosslinking during film formation other than M1"'; 3) One or more ethylenically unsaturated monomers M3"' other than M1"' and M2"'; and 4) Optionally one or more polyfunctional ethylenically unsaturated monomers M5"' for pre-crosslinking, preferably in an amount of less than 5 wt%; - Here, total weight of film-forming vinyl polymer P3 = wt% of water-soluble or water-dispersible crosslinkable vinyl oligomer OL + wt% of high molecular weight vinyl polymer P4 = i) + ii) = 100 wt%, and - Here, the total weight of the vinyl polymer in the aqueous vinyl polymer dispersion PD = wt% of vinyl polymer P1 + wt% of vinyl polymer P2 + wt% of film-forming vinyl polymer P3 = 100 wt%.

Description

Technology Field

[0001] The present invention relates to a crosslinkable aqueous vinyl polymer dispersion, a coating composition comprising said crosslinkable aqueous vinyl polymer dispersion; a paint formulation comprising said crosslinkable aqueous vinyl polymer dispersion; and an article coated with the coating composition or the paint formulation. Background Technology

[0002] Laws regarding the emission of volatile compounds are driving the transition from solvent-based to aqueous coating compositions. However, aqueous coating compositions still require improvement to achieve or match the advantageous properties of their solvent-based counterparts. A problem specific to aqueous coating compositions is the short time period during which a newly applied coating layer can be reworked without leaving visible defects in the cured coating, such as brush marks, roller marks, spray dust (commonly known as 'overspray'), or visible lines at the junction between adjacent coating layers.

[0003] A layer of a newly applied coating composition on a substrate is referred to as "open" when it is still in a state where it can be manipulated during drying without leaving substantial visible defects in the dried coating. Open time is the time between the first application of the coating layer and the point in time when no further modifications can be made to the wet paint film without leaving visible defects.

[0004] It has been a long-standing desire to improve the open time of water-based paints based on water-based film-forming coating compositions. The film-forming polymer in the water-based coating composition typically refers to a polymer having a glass transition temperature low enough to form a cohesive film on a substrate at ambient operating temperatures, and preferably having a minimum film-forming temperature in the range of 0 to 60°C.

[0005] It is believed that longer open times can be achieved by using water-soluble additives or co-bonding agents in the formulation of coatings. For example, water-soluble cosolvants such as alkylene glycols (e.g., ethylene glycol, propylene glycol, 2-methyl-2,4-pentanediol) are considered to have a beneficial effect on open time. Alternatively, water-soluble polymers such as polyvinyl alcohol, polyethylene glycol, poly(meth)acrylamide, and poly2-ethyl oxazoline have been suggested to be useful for extending the open time of aqueous coatings. However, the poor water resistance of the resulting coatings is a common problem with known water-soluble polymer open time improvers. This implies that only very low levels can actually be used, thereby reducing the effect of improving open time or wet edge time. Water-soluble additives also pose a problem, for example, when a first paint layer needs to be overcoated by a second layer of the same paint to provide sufficient opacity of the substrate. Generally speaking, the recoating properties of these paints are insufficient.

[0006] EP 136025 B1 discloses paint formulations comprising water-soluble copolymers containing both ionic and non-ionic portions. These blends can improve the open time and brushability of decorative paints, but no relevant data or claims regarding such applications are mentioned.

[0007] EP 0593151 B1 describes a method for improving the open time of an aqueous coating. This method involves combining an acrylic latex containing reactive functional groups with a modified amphiphilic low-molecular-weight compound containing reactive groups complementary to the reactive groups of the polymeric latex. The addition of the modified compound actually improved the open time of a reference paint made solely of acrylic latex. However, the open time reached only a maximum of 15 minutes, and no data was mentioned regarding the open time of the second layer and its recoating properties.

[0008] US 2001 / 0031826 A1 describes the use of emulsion polymers for the formulation of high-gloss paints having improved open times. The emulsion polymers were prepared using a mixture of (meth)acrylic monomers and polyalkylene oxide functional monomers. The open times for paints prepared with these copolymers are actually significantly higher than 20 minutes in some examples. Nevertheless, data on the recoating properties of the paints are not presented.

[0009] WO 2012 / 130817 A1 describes an aqueous composition prepared from a blend of two film-forming polymer dispersions that provides an extended open time for the first layer and excellent chemical resistance and barrier properties compared to conventional commercial trim paints. The first polymer dispersion contains groups for peripheral crosslinking and carboxylic acid / polyethylene oxide functional groups. The second polymer dispersion is derived from the group consisting of polyurethanes, vinyl polymers, or alkyds.

[0010] Despite advancements in this technology, the focus has primarily been on the open time and drying film performance of the first applied paint layer. However, trim and architectural paints are typically applied as multilayer systems to achieve sufficient opacity of the substrate. Therefore, the open time during the application of the second layer must be at the same level as that of the first paint layer. WO 2015 / 107163 A1 discloses a technology that enables an open time of 22–25 min for the first paint layer. Nevertheless, these characteristics are no longer present when a subsequent paint layer is applied and the open time decreases to approximately 30–50%. Furthermore, the flow and leveling of the second applied layer of paint are insufficient. Therefore, there is a need for water-based coatings with good open time, flow, and leveling in multilayer applied paints. Specific details for implementing the invention

[0011] The present invention relates to an aqueous polymer vinyl dispersion for use in a coating composition according to the present invention. Such an aqueous vinyl polymer dispersion PD comprises the following polymers:

[0012] 1) An aqueous dispersion of vinyl polymer P1 obtainable by free radical emulsion polymerization of a monomer mixture comprising the following:

[0013] a) 5 to 20 wt% of acid-functional ethylenically unsaturated monomer M1 or its precursor;

[0014] b) 5 to 25 wt% of an ethylenically unsaturated monomer M2 containing a polyethylene glycol or monoalkoxypolyethylene glycol portion;

[0015] c) Nonionic ethylenically unsaturated monomer M3 other than M1 or M2, up to 90 wt%;

[0016] d) 0 to 10 wt% of ethylenically unsaturated monomer M4 having functional groups for crosslinking after film formation;

[0017] e) 0 to 10 wt% of one or more chain transfer agents CTA;

[0018] Here, the sum of the wt% of M1+M2+M3+M4+CTA = 100 wt%;

[0019] 2) An aqueous dispersion or solution of vinyl polymer P2 obtainable by the following free radical copolymerization:

[0020] a) 25 to 95 wt% of an ethylenically unsaturated monomer M5 selected from the group of N-vinylamides having the following general structure:

[0021]

[0022] (In the formula, R1 and R2 are C1 to C5 alkyls and can be connected to form a ring structure, preferably N-vinylpyrrolidone or N-vinylcaprolactam);

[0023] b) 5 to 75 wt% of nonionic ethylenically unsaturated monomer M3';

[0024] c) 0 to 5 wt% of an ethylenically unsaturated monomer M4' having functional groups for crosslinking after film formation;

[0025] d) 0 to 10 wt% of acid-functional ethylenically unsaturated monomer M1' or its precursor;

[0026] e) 0 to 5 wt% of one or more chain transfer agents CTA';

[0027] Here, the sum of the wt% of M5+M3'+M4'+M1'+CTA' = 100 wt%;

[0028] 3) Film-forming vinyl polymer P3 in the form of an aqueous dispersion comprising:

[0029] i) 20 to 60 wt% of water-soluble or water-dispersible crosslinkable vinyl oligomer OL obtained by emulsion polymerization of a monomer mixture comprising the following:

[0030] 1) One or more acid-functional ethylenically unsaturated monomers M1";

[0031] 2) One or more ethylenically unsaturated monomers M4" having functional groups for crosslinking during film formation other than M1";

[0032] 3) One or more ethylenically unsaturated monomers M3" other than M1" and M2"; and

[0033] 5) Optionally, one or more chain transfer agent CTAs; and

[0034] ii) 40 to 80 wt% of high molecular weight vinyl polymer P4 prepared by emulsion polymerization of a monomer mixture comprising the following in the presence of a water-soluble or water-dispersible crosslinkable vinyl oligomer OL:

[0035] 1) Optionally one acid-functional ethylenically unsaturated monomer M1"';

[0036] 2) Optionally one or more ethylenically unsaturated monomers M4"' having functional groups for crosslinking during film formation other than M1"';

[0037] 3) One or more ethylenically unsaturated monomers M3"' other than M1"' and M2"'; and

[0038] 4) Optionally one or more polyfunctional ethylenically unsaturated monomers M5"' for pre-crosslinking, preferably in an amount of less than 5 wt%;

[0039] - Here, total weight of film-forming vinyl polymer P3 = wt% of water-soluble or water-dispersible crosslinked vinyl oligomer OL + wt% of high molecular weight vinyl polymer P4 = i) + ii) = 100 wt%; and

[0040] - Here, the total weight of the vinyl polymer in the aqueous vinyl polymer dispersion PD = wt% of vinyl polymer P1 + wt% of vinyl polymer P2 + wt% of film-forming vinyl polymer P3 = 100 wt%.

[0041] Vinyl polymers P1, P2, and P3 can be synthesized separately and can be combined by mixing their respective aqueous dispersions to form a polymer dispersion PD. The ratio of vinyl polymers P1, P2, and P3 is (1:1:98) to (65:15:20), preferably (9:1:90) to (50:10:40), more preferably (25:1.5:73.5) to (35:4.5:60.5), and most preferably (27:2:70) to (32:4:65).

[0042] The aqueous vinyl polymer dispersion PD consists of 30 wt% to 60 wt% of vinyl polymer P1+P2+P3, and the remainder is, in particular, water, a surfactant, a neutralizing base, and a biocide.

[0043] "Ethylene unsaturated monomer" means a monomer having one or more carbon-carbon double bonds capable of undergoing radical polymerization in the present invention.

[0044] When used to name the compounds of the present invention, the prefix "(meth)acrylic" refers to compounds comprising both "acrylic" and "methacrylic," as well as compounds comprising one or more CH2=CHCOO- groups or CH2=C(CH3)COO- groups, as well as mixtures thereof and mixtures of such compounds.

[0045] "Vinyl oligomer" refers to a low molecular weight polymer obtained by radical polymerization of ethylenically unsaturated monomers.

[0046] "Vinyl polymer" refers to a polymer derived from vinyl monomers containing carbon-carbon double bonds.

[0047] "The sum of the wt% of M1+M2+M3+M4+CTA = 100 wt%" means that vinyl polymer P1 is essentially composed of monomers M1, M2, M3, M4 and one or more chain transfer agents CTA as defined above. Therefore, the total weight of vinyl polymer P1 corresponds to the sum of the weight% of monomers M1, M2, M3, M4 and one or more chain transfer agents CTA.

[0048] "The sum of the wt% of M5+M3'+M4'+M1'+CTA' = 100 wt%" means that vinyl polymer P2 is essentially composed of monomers M5, M3', M4', M1' and one or more chain transfer agents CTA'. Therefore, the total weight of vinyl polymer P2 corresponds to the sum of the weight% of monomers M5, M3', M4', M1' and one or more chain transfer agents CTA'.

[0049] "Total weight of film-forming vinyl polymer P3 = wt% of water-soluble or water-dispersible crosslinked vinyl oligomer OL + wt% of high molecular weight vinyl polymer P4 = i) + ii) = 100 wt%" means that film-forming vinyl polymer P3 is essentially composed of water-soluble or water-dispersible crosslinked vinyl oligomer OL and high molecular weight vinyl polymer P4. Therefore, the total weight of film-forming vinyl polymer P3 corresponds to the sum of the weight percentages of water-soluble or water-dispersible crosslinked vinyl oligomer OL and high molecular weight vinyl polymer P4.

[0050] "Total weight of vinyl polymers in aqueous vinyl polymer dispersion PD = wt% of vinyl polymer P1 + wt% of vinyl polymer P2 + wt% of film-forming vinyl polymer P3 = 100 wt%" implies that these vinyl polymers are essentially composed of vinyl polymer P1, vinyl polymer P2, and film-forming vinyl polymer P3. Therefore, the total weight of vinyl polymers in aqueous vinyl polymer dispersion PD corresponds to the sum of the weight percentages of vinyl polymer P1, vinyl polymer P2, and film-forming vinyl polymer P3. Thus, the aqueous vinyl polymer dispersion PD is essentially composed of an aqueous dispersion of vinyl polymer P1, an aqueous dispersion or solution of vinyl polymer P2, and an aqueous dispersion of film-forming vinyl polymer P3.

[0051] The emulsion polymerization process is described in the literature ["Chemistry and Technology of Emulsion Polymerization", Editor A. van Herk, (2005), Blackwell Publishing Ltd.].

[0052] Definition of monomer

[0053] - Monomers M1, M1', M1" and M1"'

[0054] The acid-functional ethylenically unsaturated monomers M1, M1', M1" and M1"' may each be independently selected from the group consisting of carboxylic acid-functional monomers or precursors thereof, such as acrylic acid, methacrylic acid, maleic acid or its semi-ester, fumaric acid or its semi-ester, and itaconic acid or its semi-ester. These monomers may be produced from petrochemical feedstocks. Alternatively, they may be derived from renewable feedstocks. Bio-based acrylic acid may be produced from glycerol or hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof. Itaconic acid is obtained by the fermentation of sugars, and bio-based methacrylic acid may be derived from itaconic acid.

[0055] Other acid-functional non-carboxyl group-containing monomers may be, for example, sulfate or sulfone monomers. Non-limiting examples may include 2-acrylamido-2-methylpropanesulfonic acid or its alkali, ammonia, or amine salts, and the sodium salt of an adduct of allylglycidyl ether to sodium bisulfite, 2-sulfoethyl methacrylate, or 1-(allyloxy)-2-hydroxypropane-1-sulfonic acid. Additionally, phosphate or phosphonate-functional monomers may be used. Non-limiting examples of such monomers include monoacryloxyethyl phosphate, Sipomer ® PAM-100 and Sipomer ® PAM-200 (all Solvay), 10-methacryloyloxydecyl dihydrogen phosphate (Kuraray), dimethyl (2-methacryloyloxyethyl) phosphonate and dimethyl (2-methacryloyloxypropyl) phosphonate or ethyl 2-[4-(dihydroxyphosphoryl)-2-oxabutyl] acrylate.

[0056] - Monomers M2, M2', M2" and M2"'

[0057] The polyethylene oxide containing the ethylenically unsaturated monomers M2, M2', M2" and M2"' preferably comprises a monomer of the formula R3-O-(CH2-CH2-O)n-R2 (wherein R3 is acrylic or methacrylic; R2 is H or alkyl, preferably an alkyl containing 1 to 4 carbon atoms; and n is preferably an integer of 1 to 35, more preferably 2 to 20, and most preferably 3 to 15). The polyethylene oxide ethylenically unsaturated monomer preferably comprises 2 to 50, more preferably 2 to 20, and most preferably 2 to 15 ethylene oxide units. The monomer is preferably a polyethylene glycol (meth)acrylate monomer or a monomethoxy (meth)acrylate monomer. Suitable examples of polyethylene oxide ethylenically unsaturated monomer ii) are methoxypolyethylene glycol 550 methacrylate and methoxypolyethylene glycol 350 methacrylate. An example is Visiomer. ® ETMA, Visiomer ® MPEG550MA (available from Evonik), Bisomer ® S20W, Bisomer ® It is PEA6 (available from GEO Specialty Chemicals).

[0058] - Monomers M3, M3', M3" and M3"'

[0059] The nonionic ethylenically unsaturated monomers M3, M3', M3", M3"' and M3"" preferably comprise styrene and styrene derivatives, such as alpha-methyl styrene, t-butyl styrene, vinyl toluene, o-, m- and p-methyl styrene, o-, m- and p-ethyl styrene, alkyl esters of (meth)acrylic acid, vinyl esters, and hydroxyl group-containing vinyl monomers; preferred monomers comprise esters of acrylic acid and methacrylic acid, such as n-butyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and cycloalkyl (meth)acrylates, such as cyclohexyl (meth)acrylate. There are esters of itaconic acid, such as dimethyl and dibutyl itaconate. These monomers can be manufactured from petrochemical feedstocks. Alternatively, they can be derived from renewable feedstocks such as bio-based acrylic acid and methacrylic acid. The alkanols used for (trans)esterification can also be bio-derived. A non-limiting example of such monomers is Visiomer. ® Terra C13-MA, Visiomer ® Terra C17.4-MA, n-octyl acrylate, and isobornyl (meth)acrylate. Additionally, there are dienes, such as 1,3-butadiene or isoprene; or mixtures thereof. Additionally, vinyl esters, such as vinyl acetate, vinyl alkanoates, or derivatives thereof or mixtures thereof may be used in the monomer composition. Nitriles such as (meth)acrylonitrile may also be used.

[0060] - Monomers M4, M4', M4" and M4"'

[0061] Monomers M4, M4', M4", M4"', and M4"" having functional groups other than acidic groups may be used for crosslinking after film formation. M4, M4', M4", M4"', and M4"" may be the same or different. Examples of these monomers include hydroxy-functional monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, as well as monomers having latent hydroxyl groups such as glycidyl methacrylate. The hydroxy-functional groups may be crosslinked with polyisocyanates at ambient to slightly higher temperatures. Further examples include derivatives of (meth)acrylamide such as N-methylol (meth)acrylamide. Other examples of monomers are those containing a carbonyl group, such as acrolein, methacrolein, crotonaldehyde, 4-vinylbenzaldehyde, and vinyl alkyl ketones having 4 to 7 carbon atoms, such as vinyl methyl ketone. Further examples include acrylamido pivalaldehyde, methacrylamido pivalaldehyde, 3-acrylamidomethyl-anisaldehyde, diacetone acrylate and diacetone methacrylate, and keto-containing amides, such as diacetone acrylamide. Additionally, monomers having an acetoacetoxy functional group may be used. Examples of such monomers are acetoacetoxyethyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxypropyl acrylate, allyl acetoacetate, and acetoacetoxybutyl acrylate. The preferred functional groups of monomer M4, M4', M4", M4"' and M4"" respectively, are preferably carbonyl or acetoacetate groups.

[0062] In a particularly preferred embodiment, monomers M4, M4', M4", M4"' and M4"" are each selected from acetoacetoxyethyl methacrylate and diacetone acrylamide, or mixtures thereof. Crosslinking agents for use in combination with the functional groups are known to those skilled in the art and include di- or polyamines and di- or polycarboxylic acid hydrazides. Crosslinking may occur at ambient temperature or slightly higher temperature. The crosslinking agent may be pre-incorporated into a dispersion of polymers P1, P2 or P3, or may be added in a subsequent step.

[0063] - Monomer M5

[0064] Monomer M5 can each be independently selected from the group of N-vinylamides having the following general structures:

[0065]

[0066] (In the formula, R1 and R2 are C1 to C5 alkyls and can be connected to form a ring structure, preferably N-vinylpyrrolidone or N-vinylcaprolactam).

[0067] - Chain transfer agent CTA, CTA' and CTA"

[0068] Chain transfer agents CTA, CTA', and CTA" are used to control the molecular weights of polymers P1, P2, and OL. Exemplary chain transfer agents are butyl mercaptan, mercaptopropionic acid, 2-ethylhexyl mercaptopropionate, n-dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptopropionate, 2-mercaptoethanol, octyl mercaptan, isodecyl mercaptan, octadecyl mercaptan, mercaptoacetic acid, allyl mercaptopropionate, allyl mercaptoacetate, crotyl mercaptopropionate, and crotyl mercaptoacetate. Other non-sulfur-based chain transfer agents include halogenated hydrocarbons or catalytic chain transfer agents. Additionally, alpha-methyl styrene dimers or oligomers of alpha-methyl styrene dimers may be used. Polymers having a sufficiently defined molecular weight Another method of synthesis is the use of diarylethene. Commonly used diarylethene includes diphenylethene.

[0069] Definition of vinyl polymers P1, P2, and P3

[0070] - Vinyl polymer P1

[0071] Vinyl polymer P1 can be obtained by free radical aqueous emulsion polymerization in the presence of one or more free radical initiators containing free radical reactive double bonds and one or more surfactants, optionally copolymer surfactants.

[0072] Vinyl polymer P1 has a number average molecular weight, Mn, of 2,000 to 120,000 g / mole, but preferably 4,000 to 12,000 g / mole, and most preferably 5,000 to 10,000 g / mole. The weight average molecular weight (Mw) is preferably 8,000 to 50,000, and most preferably 10,000 to 25,000. The molecular weight and molecular weight distribution were determined using size exclusion chromatography (SEC) with THF and 2% acetic acid as eluents. Vinyl polymer P1 has a preferred polydispersity of 1.2 to 3.0, preferably 1.5 to 2.5—defined as the ratio of Mn / Mw. Vinyl polymer P1 contains 5 to 25 wt%, preferably 7 to 20 wt%, and most preferably 9 to 15 wt% of polyethylene oxide ethylenically unsaturated monomer M2. Vinyl polymer P1 preferably has an acid value of 30 to 150 mg KOH / g, as measured by ISO 3682. When aqueous emulsion polymerization is used, the vinyl polymer P1 is obtained in the form of a polymer dispersion, wherein the acid functional groups of the polymer are neutralized to an α value of 0.05 to 0.70, preferably 0.10 to 0.25, and the aqueous dispersion of P1 has a pH of 6.0 to 8.0, most preferably 6.5 to 7.5.

[0073] According to one embodiment, the vinyl polymer P1 has a number average molecular weight of 2,000 to 120,000 g / mole determined by size exclusion chromatography using tetrahydrofuran and 2% acetic acid as eluents and a polystyrene standard, an acid value of 30 to 150 mg KOH / g as determined by ISO 3682, and 5 to 25 wt% of an ethylenically unsaturated monomer M2 selected from the group consisting of polyethylene oxide and monoalkoxypolyethylene glycol (meth)acrylate relative to the total weight of the polymer P1.

[0074] - Vinyl polymer P2

[0075] Vinyl polymer P2 is an addition polymer that can be prepared by free radical copolymerization techniques known in the art at atmospheric or high pressure at a temperature in the range of 0 to 200 °C. It is preferable that vinyl polymer P2 be a random copolymer. Block copolymers or gradient copolymers in which pendant groups from monomer A are not uniformly distributed in the second polymer are undesirable because they are suspected of not forming a substantially water-soluble Newtonian solution. Preferably, vinyl polymer P2 is prepared by solution polymerization in an organic solvent that can be easily removed by distillation, such as methyl ethyl ketone, acetone, or iso-propanol, or in a water-miscible solvent such as butyl glycol, diethylene glycol monobutyl ether, or diethylene glycol monoethyl ether.

[0076] The vinyl polymer P2 generally has a weight average molecular weight Mw of 1,000 to 50,000 g / mole, preferably 2,000 to 40,000 g / mole, more preferably 4,000 to 25,000 g / mole, and most preferably 8,000 to 12,500 g / mole (determined by gel permeation chromatography using hexafluoro-iso-propanol as the eluent and poly(methyl methacrylate) standards for the calibration curve).

[0077] The vinyl polymer P2 preferably has a glass transition temperature Tg of -30 to 180 °C. Preferably, Tg is at least 0 °C, preferably at least 20 °C, more preferably at least 35 °C, and most preferably at least 45 °C. Good results were obtained at Tg values ​​greater than 60, 70, and 80 °C, and greater than 90 and 100 °C. Preferably, the second polymer has a Tg of 0 to 180 °C. .

[0078] As described above, vinyl polymer P2 has nonionic but hydrophilic functional groups derived from monomer M5, which provides water solubility.

[0079] Considering the expected coating characteristics, it is desirable that at least 80%, preferably 90%, or even 95% of the monomer M3' in vinyl polymer P2 has a monomer Tg of less than 120°C, preferably less than 100°C, 50°C, or 20°C, and more preferably less than -10°C.

[0080] The vinyl polymer P2 additionally contains 0 to 5 wt% of crosslinking monomer M4', which is different from monomers M1' and M2'. The effective amount of monomer M3' is in the range of 5 to 75 wt%.

[0081] The vinyl polymer P2 additionally contains 0-5 wt% of the chain transfer agent CTA'.

[0082] In the most preferred embodiment, vinyl polymer P2 is a copolymer of N-vinyl pyrrolidone and ethyl acrylate. Additionally, a copolymer of N-vinyl caprolactam and ethyl acrylate is preferred.

[0083] - Film-forming vinyl polymer P3

[0084] Vinyl polymer P3 is a film-forming polymer obtained by polymerizing vinyl polymer P4 in the presence of water-soluble or water-dispersible vinyl oligomer OL.

[0085] - Water-soluble or water-dispersible crosslinked vinyl oligomer OL

[0086] The water-soluble or water-dispersible crosslinkable vinyl oligomer OL is typically an acid-functional oligomer formed from monomers M1", M3" and M4" and a chain transfer agent CTA". The oligomer preferably has a number average molecular weight Mn in the range of 500 g / mole to 50,000 g / mole, more preferably 2,500 g / mole to 25,000 g / mole, and most preferably 5,000 g / mole to 15,000 g / mole. The number average molecular weight and weight average molecular weight (Mn and Mw) of the oligomer can be determined using gel permeation chromatography with a polymer such as polystyrene of known molecular weight as a standard and THF containing 2% acetic acid as the eluent. The crosslinkable vinyl oligomer OL preferably has a glass transition temperature in the range of 10 to 150 °C, more preferably 20 to 125 °C, and most preferably 25 to 115 °C.

[0087] In this document, Tg of the oligomer OL represents the calculated glass transition temperature and is well known as the temperature at which the polymer changes from a glassy brittle state to a rubbery state. The Tg value can be calculated using the well-known Fox equation (TG Fox, Bull. Am. Phys. Soc. 1, 123 (1956)), which is well known in the art, and is expressed by the following formula:

[0088] 1 / Tg = W1 / Tg(1) + W2 / Tg(2) + W3 / Tg(3) + … …

[0089] (In the formula, W1, W2, W3, etc. are weight fractions of comonomers (1), (2) and (3) (etc.), and Tg(1), Tg(2), Tg(3) are the glass transition temperatures of their respective homopolymers). Calculations are performed using the glass transition values ​​for homopolymers described in the literature [Polymer Handbook, 4th edition (editors: J. Brandrup, EH Immergut, EA Grulke, John Wiley & Sons, Inc. 1999)]. Tg calculated in Kelvin can be easily converted to Celsius.

[0090] Vinyl oligomer OL preferably has an acid value of 45 mg KOH / g or more, more preferably 50 mg KOH / g or more, and most preferably 55 mg KOH / g or more.

[0091] Methods for influencing molecular weight in emulsion polymerization to achieve a desired number average molecular weight are sufficiently known to those skilled in the art. Molecular weight control of oligomers can be provided using chain transfer agents such as mercaptans and halogenated hydrocarbons. Suitable mercaptans include n-dodecyl mercaptan, n-octyl mercaptan, t-dodecyl mercaptan, 2-mercaptoethanol, iso-octyl thioglycolurate, C2 to C8 mercaptocarboxylic acids and esters thereof, such as 3-mercaptopropionic acid and 2-mercaptopropionic acid.

[0092] Crosslinkable vinyl oligomers OL can be prepared by any known technology and may include directly synthesizing the oligomer in an aqueous process, i.e., in the presence of water (e.g., by emulsion polymerization, suspension polymerization, micro-suspension polymerization, or mini-emulsion polymerization), or by solution polymerization in which the solvent may be water or any organic solvent that is miscible with water or is removed by distillation after the oligomer is transferred to water. If the oligomer is a macromonomer, it may be prepared by a number of processes including, but not limited to, the use of a reversible addition fragmentation (RAFT) agent, by the use of a catalytic chain transfer agent such as a cobalt-chain transfer agent. Additionally, alpha-methyl styrene dimers or alpha-methyl styrene dimer oligomers may be used as described in US 2007 / 0043156 A1 and US 6,872,789. Another method for synthesizing polymers with a sufficiently defined molecular weight is the use of diarylethenes such as diphenylethene, or a high-temperature process.

[0093] Preferably, vinyl oligomer OL is prepared by solution polymerization, emulsion polymerization, or suspension polymerization. Preferably, the oligomer is prepared by an aqueous process. Preferably, the continuous phase of the aqueous process comprises > 50 wt%, more preferably > 80 wt%, and most preferably > 95 wt% of water.

[0094] Most preferably, vinyl oligomer OL is produced by an aqueous free radical emulsion polymerization process.

[0095] Free radical polymerization can be carried out as a batch or semi-continuous polymerization process.

[0096] Free radical emulsion polymerization typically requires the use of a free radical initiator to initiate polymerization. Suitable free radical initiators include inorganic peroxides such as K, Na, or ammonium persulfates, hydrogen peroxides, or percarbonates; organic peroxides such as acyl peroxides including, for example, benzoyl peroxide; alkyl hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; dialkyl peroxides such as di-t-butyl peroxide; peroxy esters such as t-butyl perbenzoate; and mixtures may also be used. In some cases, peroxy compounds include Na or K pyrosulfites or bisulfites, Bruggolite ® It is advantageously used in combination with suitable reducing agents (redox systems) such as FF6 (trademark, L. Bruggemann GmbH & Co. KG) and iso-ascorbic acid. Additionally, metal compounds such as Fe. EDTA (EDTA is ethylenediamine tetraacetate) can be used as part of the redox initiator system. Furthermore, azo-functional initiators, such as azobis(isobutyronitrile), 2,2'-azobis(2-methylbutanenitrile) (ANBN); and 4,4'-azobis(4-cyanovaleric acid) may be used. Initiator systems that split the aqueous and organic phases, such as t-butyl hydroperoxide, iso-ascorbic acid, or Bruggolite, may be used. ®It is possible to use a combination of FF6 and Fe. EDTA. The amount of initiator or initiator system used is typical, for example, within the range of 0.05 to 6 weight percent relative to the total vinyl monomer used. Preferred initiators for producing crosslinkable oligomers include ammonium persulfate, sodium persulfate, potassium persulfate, azobis(isobutyronitrile) and / or 4,4'-azobis(4-cyanovaleric acid). The most preferred initiators for producing crosslinkable oligomers include the redox system and persulfate as described above. An additional amount of initiator may optionally be added at the end of the polymerization process to assist in the removal of any residual vinyl monomer.

[0097] When crosslinkable vinyl oligomer OL is prepared by emulsion polymerization, a surfactant may be used to assist in the dispersion or emulsification of the vinyl copolymer in water (even if it is self-dispersible). Suitable surfactants are ionic or nonionic surfactants. Examples of anionic emulsifiers are potassium laurate, potassium stearate, potassium oleate, sodium decyl sulfate, sodium dodecyl sulfate, and sodium rosinate. Examples of nonionic emulsifiers are linear and branched alkyl and alkylaryl polyethylene glycol ethers and thioethers, linear and branched alkyl and alkylaryl polypropylene glycol ethers and thioethers, alkylphenoxypoly(ethyleneoxy)ethanol, for example, an adduct of 1 mole of nonylphenol to 5-50 moles of ethylene oxide, or an alkali salt or ammonium salt of the sulfate or phosphate of said adduct.

[0098] In addition, surfactants containing olefinic unsaturated groups capable of participating in free radical polymerization may be used. A suitable polymerizable surfactant is of the formula M. + . OOC-CH=CHCOOR (wherein R is a C6 to C22 alkyl, and M + is Na +, K + , Li + , NH4 + It includes hemi-esters of maleic anhydrides of (or protonated or quaternary amines). Polyoxyethylene alkylphenyl ethers having ethylenically unsaturated bonds are sold under the trade name Noigen® RN (e.g., Montello, Inc.), such as NOIGEN™ RN-10, NOIGEN™ RN-20, NOIGEN™ RN-30, NOIGEN™ RN-40, and NOIGEN™ RN-5065, or their sulfates are HITENOL ® BC-10, HITENOL ® BC-1025, HITENOL ® BC-20, HITENOL ® BC-2020, HITENOL ® Hitenol, a brand name like BC-30 ® It is sold as a BC (e.g., Montello, Inc.). MAXEMUL ® 6106 (available from Croda) has both a phosphonate ester and a nominal C18 alkyl chain having an ethoxyhydrophilic, acrylate-reactive group. Other representative reactive surfactants having phosphate ester functional groups suitable for these reactions are, without limitation, MAXEMUL ® 6112, MAXEMUL ® 5011, MAXEMUL ® Includes 5010 (all available from Croda Industrial Specialties). Alternative reactive surfactants suitable for use with various embodiments of the present invention include sodium allyloxyhydroxypropyl sulfonate (SIPOMER ® (Obtainable from Solvay as COPS-1), ADEKA REASOAP ® SR / ER series, for example, ADEKA REASOAP ®ER-10, ER-20, ER-30, and ER-40, Akeda Reasoap SR-10, SR-20, SR-30 (all available from Asahi Denka Co., Ltd.) and allylsulfosuccinate derivatives (e.g., TREM ® Includes LT-40 (available from BASF).

[0099] The amount of surfactant used in the synthesis of the oligomer is preferably 0 to 15 weight%, more preferably 0 to 8 weight%, even more preferably 0 to 5 weight%, and particularly 0.1 to 3 weight%.

[0100] - High molecular weight vinyl polymer P4

[0101] Preferably, vinyl polymer P4 is prepared by an aqueous process in the presence of a crosslinkable vinyl oligomer OL. Prior to the polymerization of vinyl polymer P4, the crosslinkable vinyl oligomer may be partially or completely solubilized. Most preferably, vinyl polymer P4 is prepared by an aqueous emulsion polymerization process.

[0102] A method for producing vinyl polymer P4 may be carried out in various ways, including but not limited to polymerizing vinyl oligomer OL and monomer M3"' and optionally M1"' and / or M2"' and / or M4"' all in one batch, pre-charging the solubilized or partially solubilized vinyl oligomer OL into a reactor, then feeding the monomer in one or more steps and / or using a gradient feeding technique (or vice versa), feeding both the oligomer OL and the monomer into the reactor (optional pre-charging some oligomers), feeding the monomer to the oligomers fed simultaneously into the reactor (optional pre-charging some vinyl oligomers), or continuously feeding a mixture of vinyl oligomers and monomers into the reactor to produce the vinyl polymer.

[0103] Preferably, free radical polymerization to obtain vinyl polymer P4 is carried out by heating the reactor contents to a temperature in the range of 30°C to 100°C, and more preferably in the range of 50°C to 90°C.

[0104] The vinyl polymer P4 has a glass transition temperature of -70°C to 50°C, more typically -25°C to 40°C, and must be at least 25°C lower, more preferably at least 40°C lower than the Tg of the vinyl oligomer OL. The weight average molecular weight of the vinyl polymer P4 must be at least 60,000 g / mole, preferably at least 100,000 g / mole.

[0105] The film-forming vinyl polymer P3, comprising oligomer OL and polymer P4, is preferably in the form of an aqueous polymer dispersion.

[0106] The vinyl polymer P3 comprises 20 to 60 wt% of vinyl oligomer OL, preferably 25 to 55 wt% of vinyl oligomer OL, and most preferably 25 to 52.5 wt% of vinyl oligomer OL.

[0107] The solid content of the aqueous dispersion of vinyl polymer P3 is preferably in the range of 20 to 60 wt%, and most preferably in the range of 30 to 50 wt%.

[0108] - Initiator

[0109] Free radical polymerization will require the use of a free radical initiator to initiate polymerization. Suitable free radical initiators include inorganic peroxides such as potassium-, sodium-, or ammonium persulfates, hydrogen peroxides, or percarbonates; organic peroxides such as acyl peroxides including, for example, benzoyl peroxide; alkyl hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; dialkyl peroxides such as di-t-butyl peroxide; peroxy esters such as t-butyl perbenzoate; and mixtures may also be used. In some cases, peroxy compounds are advantageously used in combination with suitable reducing agents (redox systems) such as sodium- or potassium pyrosulfite or bisulfite, sodium formaldehyde sulfoxylate, and iso-ascorbic acid. Additionally, Bruggolite ®Non-formaldehyde emitting reducing agents such as FF6 may be used. Additionally, metal compounds such as Fe.EDTA (EDTA is ethylenediamine tetraacetate) may be used as part of a redox initiator system. Furthermore, azo-functional initiators, such as azobis(isobutyronitrile), 2,2'-azobis(2-methylbutanenitrile) (ANBN); and 4,4'-azobis(4-cyanovaleric acid) may be used. It is possible to use an initiator system that separates the aqueous phase and the organic phase, for example, a combination of t-butyl hydroperoxide, iso-ascorbic acid, and Fe.EDTA. The amount of the initiator or initiator system used is typical and is, for example, within the range of 0.05 to 6 wt% relative to the total vinyl monomer used. Preferred initiators for preparing vinyl polymers P1, P3, and P4 and vinyl oligomer OL include ammonium persulfate, sodium persulfate, potassium persulfate, azobis(isobutyronitrile) and / or 4,4'-azobis(4-cyanovaleric acid). An additional amount of initiator may optionally be added at the end of the polymerization process to assist in the removal of any residual vinyl monomer.

[0110] - surfactants

[0111] When free radical polymerization for the synthesis of P1 and P3 is carried out as emulsion polymerization, a surfactant must be used. Suitable surfactants are ionic or nonionic surfactants. Examples of anionic emulsifiers are potassium laurate, potassium stearate, potassium oleate, sodium decyl sulfate, sodium dodecyl sulfate, and sodium rosinate. Examples of nonionic emulsifiers are linear and branched alkyl and alkylaryl polyethylene glycol ethers and thioethers and linear and branched alkyl and alkylaryl polypropylene glycol ethers and thioethers, alkylphenoxypoly(ethyleneoxy)ethanol, for example, an adduct of 1 mole of nonylphenol to 5-50 moles of ethylene oxide, or an alkali salt or ammonium salt of the sulfate or phosphate of said adduct.

[0112] In addition, surfactants containing olefinic unsaturated groups capable of participating in free radical polymerization may be used. A suitable polymerizable surfactant is of the formula M. + - OOC-CH=CHCOOR (wherein R is a C6 to C22 alkyl, and M + is Na + , K + , Li + , NH4 +It includes a hemi-ester of maleic anhydride of (or a protonated or quaternary amine). Polyoxyethylene alkylphenyl ethers having ethylenically unsaturated bonds are sold under the trade name Noigen® RN (e.g., Montello, Inc.), such as NOIGEN® RN-10, NOIGEN® RN-20, NOIGEN® RN-30, NOIGEN® RN-40, and NOIGEN® RN-5065, or their sulfates are sold under the trade name Hitenol® BC (e.g., Montello, Inc.), such as HITENOL® BC-10, HITENOL® BC-1025, HITENOL® BC-20, HITENOL® BC-2020, and HITENOL® BC-30. MAXEMUL™ 6106 (available from Uniquema) is a nominal C18 alkyl chain having both phosphonate ester and ethoxyhydrophilic properties and an acrylate reactive group. Other representative reactive surfactants having phosphate ester functional groups suitable for this reaction include, but are not limited to, MAXEMUL® 6112, MAXEMUL® 5011, and MAXEMUL® 5010 (all available from Croda Industrial Specialties). Alternative reactive surfactants suitable for use with various embodiments of the present invention include sodium allyloxyhydroxypropyl sulfonate (available from Solvay as SIPOMER® COPS-1), the ADEKA REASOAP® SR / ER series, such as ADEKA REASOAP® ER-10, ER-20, ER-30 and ER-40, Akeda REASOAP® SR-10, SR-20, SR-30 (all available from Asahi Denka Co., Ltd.), and allylsulfosuccinate derivatives (e.g., TREM® LT-40 (available from BASF)).

[0113] The present invention also relates to a coating composition COA comprising an aqueous vinyl polymer dispersion PD.

[0114] The coating composition COA may have a pH of 2.0 to 9.0, preferably 4.5 to 8.5, and most preferably 7.5 to 8.0. The coating composition COA described above may preferably be formulated into a paint by adding conventional paint additives. Such a composition may still be referred to as a coating composition. The coating composition COA may further comprise one or more organic solvents, pigments (organic or inorganic), and / or other additives and fillers known in the art that aid in film formation. When an organic solvent is used, a water-miscible solvent is preferred. The amount of organic solvent should be selected in such a way that it provides a coating composition having a low volatile organic content (VOC), preferably comprising less than 50 g / liter, preferably less than 30 g / liter, of volatile organic compounds in water, as calculated by ISO Method 11890-2 in a form readily available for use.

[0115] According to one embodiment, a coating composition COA comprising an aqueous vinyl polymer dispersion PD may further comprise at least one conventional component selected from pigments, dyes, emulsifiers, surfactants, plasticizers, thickeners, heat stabilizers, leveling agents, anti-cratering agents, fillers, sedimentation inhibitors, UV absorbers, antioxidants, desiccant salts, organic cosolvents, wetting agents, etc., or mixtures thereof.

[0116] According to another embodiment, the coating composition COA may also comprise one or more of the following coating additives, but not limited to: leveling agents, rheology, anti-blocking agents and flow control agents, such as silicone, fluorocarbon, urethane or cellulose; extenders; leveling agents; pigment wetting agents and dispersants and surfactants; ultraviolet (UV) absorbers; UV light stabilizers; coloring pigments; defoaming agents and anti-foaming agents; anti-settling agents, anti-sagging agents and boarding agents; anti-film agents; anti-waterlogging agents and anti-floating agents; fungicides and mold removers; corrosion inhibitors; thickeners; plasticizers; reactive plasticizers; drying agents; catalysts; or adhesives. The present invention also relates to a coating composition and a paint composition comprising 1-70 wt% of a pigment or filler. Preferably, the pigment used is rutile titanium dioxide having an oil absorption of less than 25 g oil / 100 g pigment, as determined by ASTM D281-12 (2016).

[0117] The coating composition COA according to the present invention may further comprise up to 20 wt%, preferably up to 15 wt%, 10 wt%, or 5 wt% of an isocyanate crosslinker; up to 20 wt%, preferably up to 5 wt% of a polyhydrazide crosslinker; up to 10 wt% of a silane crosslinker; and up to 10 wt% of a (meth)acryloyl oligomer.

[0118] As mentioned above, the coating composition according to the present invention is suitable for various coating applications, for example, as a paint, impregnation, sealing, and bonding composition. Preferred applications are as a primer, topcoat, or clear coat. The coating composition can be applied to a substrate in any ordinary and convenient manner, such as by brushing, spraying, or immersion. Suitable substrates include metal, wood, board, plastic, and leather.

[0119] The present invention also relates to a method for preparing a coating composition COA, comprising the step of combining an aqueous vinyl polymer dispersion PD with at least one conventional component selected from pigments, dyes, emulsifiers, surfactants, plasticizers, thickeners, heat stabilizers, leveling agents, anti-cratering agents, fillers, sedimentation inhibitors, UV absorbers, antioxidants, desiccant salts, organic cosolvents, wetting agents, etc., or mixtures thereof.

[0120] Preferably, the coating composition COA is an aqueous coating composition.

[0121] The present invention also relates to a paint formulation comprising a coating composition COA or a paint formulation comprising a vinyl polymer dispersion PD. According to one embodiment, the paint formulation is preferably a colored formulation.

[0122] The present invention also relates to the use of an aqueous vinyl polymer dispersion PD to increase the open time, wet edge time, and / or hardness of a coating composition.

[0123] The present invention also relates to articles coated with a coating composition COA or a paint formulation.

[0124] The present invention will be explained in more detail by the following non-limiting examples.

[0125] All embodiments described above may be combined within a reasonable scope.

[0126] Examples

[0127] Test method

[0128] 1 g of dispersion is weighed into a tin cup, and the cup is placed in an air-circulating oven at 125 °C for 60 minutes to measure the solid content (SC). The difference in weight is related to the volatile content, and the remaining non-volatile portion is the solid content. If the viscosity is high, 1 g of water is added before heating. If the polymer contains a co-solvent, the method described above does not provide an accurate solid content value. Consequently, a theoretical solid content is used.

[0129] Molecular weight and molecular weight distribution were determined using size exclusion chromatography (SEC). The SEC apparatus used was an Alliance system consisting of a pump, auto-sampler, and a He-degassing unit (Degasys DG-1210 from Uniflows), equipped with a PL-gel 5 µm MIXED-C 600 × 7.5 mm column and a PL-gel 5 µm guard column (50 × 7.5 mm - Polymer Laboratories). The column oven (Separations Analytical Instruments) 5 was set to 30 °C. Tetrahydrofuran (THF - Extra Dry, Biosolve 206347) + 2% acetic acid (Baker 6052) was used as the eluent at a flow rate of 0.8 ml / min. Carbon disulfide (Backer) was used as a marker. A Waters 410 refractive index detector was used. The injection volume was 100 μl at a concentration of 1.5 mg / ml. Poly(styrene) standards (Polymer Laboratories, Easical PS-1, 2010-0501 (M range 580 g / mole - 8,500,000 g / mole) and Easical PS-2, 2010-0601 (M range 580 g / mole - 400,000 g / mole)) were used for calibration using a third-order polynomial. The software used for data analysis was Empower (Waters). For the analysis of the molecular weight of polymer P2, the eluent was substituted with hexafluoroisopropanol, and the poly(styrene) standards were substituted with poly(methyl methacrylate) standards.

[0130] Brookfield viscosity is measured using a Brookfield RVT viscometer at a temperature of 23 ± 1 ℃ in accordance with ISO 2555-1974.

[0131] Particle size was measured by dynamic light scattering using a Malvern Zetasizer model Nano-S90. The Z-mean value was reported as the particle size. The z-mean diameter is the average hydrodynamic diameter and is calculated according to the international standard for dynamic light scattering ISO 13321.

[0132] Early Water Resistant (EWR) was measured by applying an 80 µm wet film to a Leneta plain chart. After drying for 24 hours at 23 °C and 45–55% relative humidity, droplets were placed on the surface of the paint and left for 0.5, 1, and 2 hours. After these times, water was removed with a cloth. Damage in the form of bubbles was assessed immediately and after 24 hours of recovery. The reported EWR is one of 1 hour of water contact and 24 hours of recovery. A scale from 1 (complete removal or sufficient bubble formation) to 5 (no damage) was used.

[0133] The paint open time was determined by applying 125 microns of paint onto a Leneta Plane Chart FORM WH using a bar applicator under acclimated conditions of 23 ℃ and 45–55% relative humidity. The evaporation rate of the water-based paint was 22 mg / m² / sec. An X-shaped cross was applied to the paint layer immediately after application using a pencil rubber eraser with a width of at least 2 mm. Fresh paint was loaded into a brush (Elma acryl 93-14 or Pro-Gold Exclusive 7200-12), and excess paint was removed by scraping along the edge of the can. At the location of the X-shaped cross, the newly loaded brush was moved twice perpendicular to the width of the substrate and twice horizontally along the length of the substrate. These movements were repeated 10 times for the same cross ("10 cross-brushes"). This procedure was repeated after a 1 or 2-minute interval for the next cross until a cross was visible even after 10 "cross-brushes" (1 pass = 2 times in the width direction of the substrate and 2 times in the length direction of the substrate). The open time was reported as the time during which X-cross-shaped damage on the newly applied film could be completely removed after 10 "cross-brushes" within the next interval of 1 or 2 minutes. A 2-minute interval could be selected to obtain the first indication of the open time; more accurate open time measurements were performed at 1-minute intervals.

[0134] Konig hardness was measured according to ASTM D 2457; 100 µm wet application on glass, room temperature and drying for 16 h at 50°C.

[0135] Initial anti-blocking performance was measured by applying the coating to a test chart with a wet layer thickness of 150 µm. The coating was dried at room temperature for 24 hours. Blocking was tested for 4 hours at a temperature of 50°C under a pressure of 1 kg / cm² according to ASTM D4946-89.

[0136] Example 1. Preparation of an aqueous dispersion of vinyl polymer P1 by emulsion polymerization.

[0137] In an emulsion polymerization reactor equipped with a cooler, a stirrer, a monomer feed addition tank, and an initiator addition tank, a pre-emulsion was prepared as follows: 454 g of water and 5 g of anionic polymerizable surfactant (Resoap ® SR-1025) was added and heated to 70 ℃. In the feed tank, 117 g of water, 22.8 g of anionic polymerizable surfactant Reasoap ® A mixture of SR-1025 (e.g., Adeka Corporation) and 0.3 g of sodium lauryl sulfate was mixed for 5 minutes. A monomer pre-emulsion was prepared by adding the following raw materials to a feed tank: 109.5 g of methyl methacrylate and 24.2 g of Visiomer. ® ETMA (ethyl triglyceride methacrylate, Rohm GmbH), 24.2 g of methacrylic acid, 145.7 g of n-butyl methacrylate, 3.56 g of octyl mercaptan, and 1.75 g of 2-mercaptoethanol. The contents of the feed tank were stirred until a stable pre-emulsion was obtained.

[0138] A 5 wt.% pre-emulsion was injected into the reactor. The reactor was heated to 80 °C. Upon reaching this temperature, a solution of 0.3 g of ammonium persulfate in 6.3 g of water was added to the reactor. After waiting for 5 minutes, the reactor was heated to 85 °C. The feed of the pre-emulsified monomer into the reactor was started. Simultaneously, the feed of an initiator solution consisting of 0.75 g of ammonium persulfate in 15.2 g of water was started. The monomer feed injection was completed within 60 minutes. The initiator feed injection took 70 minutes. The following finishing steps were performed: the feed tank was rinsed with 21.0 g of water, and the initiator tank was rinsed with 6.7 g of water. After completing the feed, the temperature was maintained for an additional 60 minutes. The batch was cooled to 65 °C, and a slurry of 4.0 g of water mixed with 0.75 g of tertiary butyl hydroperoxide (70 wt.% aqueous solution) was added. A solution of 16.0 g of water and 0.35 g of sodium formaldehyde sulfoxylate was injected into the reactor over a period of 15 minutes. The contents of the reactor were maintained at a temperature of 65 °C for an additional 30 minutes. Subsequently, the reactor was cooled to a temperature of 25 °C. At a temperature of 25 °C, 3.1 g of Proxel in 4.0 g of water ® A solution of AQ (a 10% solution of benzisothiazolone, e.g., Lonza) was added, and the beaker was rinsed with 4.0 g of water. A solution of 1.65 g of 25 wt% ammonia in 4.0 g of water was added to the reactor. The beaker was rinsed with 4.0 g of water. An aqueous polymeric vinyl dispersion polymer having both ethylene oxide and carboxylic acid functional groups was obtained with the following characteristics: SC = 32%; pH = 7.5; residual monomer < 100 ppm; particle size = 122 nm. The molecular weight was measured to be Mn = 5,000 and Mw = 13,200.

[0139] Example 2. Preparation of an aqueous solution of vinyl polymer P2.

[0140] 930.80 g of methyl ethyl ketone was added to a polymerization reactor and heated under reflux (86 °C). Subsequently, 31.90 g of methyl ethyl ketone and 3.20 g of the initiator Perkadox ® A mixture of AMBN (2,2'-azobis(2-methylbutyronitrile), e.g., Nouryon) was added to a reactor over a period of 3 hours along with 1,438.00 g of (N)-vinylpyrrolidone and 359.30 g of ethyl acrylate. The reactor was maintained at reflux temperature for 30 minutes after the reaction. The reactor was cooled to 75 °C, and 1,237 g of deionized water was added. Distillation of methyl ethyl ketone was initiated until the residual methyl ethyl ketone was < 0.1%. Finally, additional water was added to reach a theoretical solid content of 50%. The resulting second polymer was a clear solution with slight haze and had a solid content of 49.7%. It had a weight-average molecular weight of 51,300 g / mol and a number-average molecular weight of 12,600 g / mol.

[0141] Example 3. Preparation of an aqueous dispersion of polymer P3.

[0142] The initial step is the synthesis of vinyl oligomer OL: in a 7-liter reactor, 3,089 g of deionized water and 35.44 g of Reasoap ® SR-1025 was charged. The reactor contents were heated to 80 °C while creating a nitrogen atmosphere in the reactor. The nitrogen atmosphere was maintained throughout the entire polymerization process. 99.21 g of Reasoap ®A preliminary emulsion was prepared by dissolving SR-1020 in 779.8 g of deionized water. To this, 1,297 g of methyl methacrylate, 231 g of diacetone acrylamide, 164.5 g of methacrylic acid, 294.7 g of n-butyl methacrylate, 22.1 g of n-octyl mercaptan, and 11.34 g of 2-mercaptoethanol were added under stirring.

[0143] 5% of this pre-emulsion was added to the reactor. When the temperature reached 80 °C, 1.754 g of ammonium persulfate dissolved in 85.03 g of deionized water was added to the reactor. The temperature was raised to 85 °C, and the remainder of the pre-emulsion was added over a period of 60 minutes. The beaker containing the pre-emulsion was rinsed with 177.2 g of deionized water. The beaker containing the initiator solution was rinsed with 42.51 g of water. After maintaining the batch at 85 °C for 30 minutes, 124.8 g of ammonia (25% concentration) dissolved in 255.3 g of water was added over a period of 30 minutes. The pH of the solution was 8.2. The batch was maintained at 85 °C for an additional 120 minutes. After this holding period, the contents of the reactor were cooled to room temperature. The product was filtered through a filter bag and stored in a polyethylene container. Analysis indicated that the crosslinkable oligomer had a number average molecular weight of 7,000 g / mole and a weight average molecular weight of 16,500 g / mole.

[0144] In the second step, vinyl polymer P4 was prepared in the presence of the vinyl oligomer described above. 4.549 g of the oligomer solution from the initial step was charged into a 7-liter reactor and heated to 45 °C while stirring under a nitrogen atmosphere. A monomer mixture consisting of 391.3 g of methyl methacrylate, 933.3 g of n-butyl acrylate, 20.71 g of divinylbenzene, and 43.58 g of styrene was prepared. 50% of this mixture was added to the reactor. After mixing for 30 minutes, 0.59 g of tertiary butyl hydroperoxide (70% aqueous solution) was added, followed by the addition of 50% of a solution of 0.0382 g of iron(II) sulfate heptahydrate and 0.0478 g of disodium ethylenediamine tetraacetate dehydrate in 58.16 g of deionized water. 2.533 g of Bruggolite in 290.5 g of deionized water. ® A solution of FF6M (e.g., L. Bruggemann GmbH & Co. KG) was prepared, and 43.95 g of this solution was added to the reactor. The batch was exothermic at 54.9 °C and maintained at 55 °C for 45 minutes. After this holding period, the reactor was cooled to 50 °C, and the remainder of the monomer was added. The batch was maintained at 50 °C for 30 minutes. The beaker containing the monomer mixture was rinsed with 316.4 g of deionized water and added to the reactor. 2.46 g of tertiary butyl hydroperoxide (70% aqueous solution) and the remainder of the iron(II) sulfate heptahydrate / disodium ethylenediamine solution were added to the reactor, followed by 43.95 g of Bruggolite ® FF6M solution was added. The batch became exothermic, raising the temperature to 60 ℃. After 15 minutes, Bruggolite ®The remainder of the FF6M solution was poured into the reactor over a period of 30 minutes. 64.63 g of adipic acid dihydrazide was added through the addition funnel. The funnel was rinsed with 316.4 g of deionized water. The batch was cooled to ambient temperature. 21.31 g of Proxel was added to the reactor. ® AQ was added and then rinsed with 21.78 g of deionized water. The batch was filtered through a filter bag and stored in a suitable container. The dispersion had a solid content of 39.8 g, a pH of 8.1, a Brookfield viscosity of 198 cPa·s, and a particle size of 49 nm. The MFFT was 17 °C.

[0145] Examples 4 and 5 (Comparative Examples): Aqueous coating compositions

[0146] A white colored coating formulation was prepared using the ingredients from Table 1.

[0147] A mill base was prepared at room temperature in a cooled container. Deionized water, an antifoaming agent, a dispersant, and a surfactant were filled into a container equipped with a stirring device having a dissolving blade. Subsequently, titanium dioxide was slowly added under high-speed stirring (2,000–3,000 rpm, 50 mm disc size, 80 mm container diameter). After addition, stirring was continued for 30 minutes. The fineness of the grind is less than 10 µm.

[0148] After preparing the mill base, a coating composition containing a binder was added to the binder (along with the composition according to the present invention) in a pre-filled let-down container under stirring (1,000 - 1,500 rpm, 80 mm disc size, container diameter 150 mm). When prepared, deionized water, an antifoaming agent, an anti-slip agent, a co-solvent, an amine, a biocide, a thickener, and a co-solvent were added while stirring.

[0149] After stabilizing overnight, 2.7-3.0 Poise (10,000 sec -1Extra thickener was added up to an ICI viscosity. The next day, paint was applied to all tests.

[0150] Table 1. Colored coatings (amount in grams)

[0151]

[0152] Table 2 shows the performance of the colored coating formulations shown in Table 1.

[0153] Table 2. Performance of paint

[0154]

[0155] From Table 2, it becomes evident that the coating composition according to the present invention has an excellent open time during the application of the second coating layer without impairing other coating properties.

Claims

Claim 1 An aqueous vinyl polymer dispersion PD comprising the following: - 1) an aqueous dispersion of vinyl polymer P1 obtainable by free radical emulsion polymerization of a monomer mixture comprising the following: a) 5 to 20 wt% of an acid-functional ethylenically unsaturated monomer M1 or its precursor; b) 5 to 25 wt% of an ethylenically unsaturated monomer M2 containing a polyethylene glycol or monoalkoxypolyethylene glycol moiety; c) up to 90 wt% of a nonionic ethylenically unsaturated monomer M3 other than M1 or M2; d) 0 to 10 wt% of an ethylenically unsaturated monomer M4 having functional groups for crosslinking after film formation; e) 0 to 10 wt% of one or more chain transfer agents CTA; wherein the sum of the wt%s of M1+M2+M3+M4+CTA = 100 wt%; - 2) by the following free radical copolymerization Aqueous dispersion or solution of obtainable vinyl polymer P2: a) 25 to 95 wt% of ethylenically unsaturated monomer M5 selected from the group of N-vinylamides having the following general structure: (wherein R1 and R2 are C1 to C5 alkyls and may be connected to form a ring structure, or N-vinylpyrrolidone or N-vinyl caprolactam); b) 5 to 75 wt% of a nonionic ethylenically unsaturated monomer M3' other than M5; c) 0 to 5 wt% of an ethylenically unsaturated monomer M4' having functional groups for crosslinking after film formation; d) 0 to 10 wt% of an acid-functional ethylenically unsaturated monomer M1' or its precursor; e) 0 to 5 wt% of one or more chain transfer agents CTA'; where the sum of the wt%s of M5+M3'+M4'+M1'+CTA' = 100 wt%; - 3) Film-forming vinyl polymer P3 in the form of an aqueous dispersion comprising: i) a water-soluble or obtained by emulsion polymerization of a monomer mixture comprising the following Water-dispersible crosslinkable vinyl oligomer OL 20 to 60 wt%: 1) one or more acid-functional ethylenically unsaturated monomers M1"; 2) one or more ethylenically unsaturated monomers M4" having functional groups for crosslinking upon film formation other than M1"; 3) one or more ethylenically unsaturated monomers M3" other than M1" and M2", wherein M2" is an ethylenically unsaturated monomer containing a polyethylene glycol or monoalkoxypolyethylene glycol moiety; and ii) high molecular weight vinyl polymer P4 prepared by emulsion polymerization of a monomer mixture comprising the following in the presence of water-soluble or water-dispersible crosslinkable vinyl oligomer OL: one or more ethylenically unsaturated monomers M3"' other than M1"' and M2"', wherein M1"' is an acid-functional ethylenically unsaturated monomer and M2"' is It is an ethylenically unsaturated monomer containing a polyethylene glycol or monoalkoxypolyethylene glycol portion;- Here, the total weight of film-forming vinyl polymer P3 = wt% of water-soluble or water-dispersible crosslinkable vinyl oligomer OL + wt% of high molecular weight vinyl polymer P4 = i) + ii) = 100 wt%, and - Here, the total weight of vinyl polymers in aqueous vinyl polymer dispersion PD = wt% of vinyl polymer P1 + wt% of vinyl polymer P2 + wt% of film-forming vinyl polymer P3 = 100 wt%.; Claim 2 In claim 1, an aqueous vinyl polymer dispersion PD comprising a water-soluble or water-dispersible crosslinkable vinyl oligomer OL further comprising one or more chain transfer agents CTA. Claim 3 In claim 1, the aqueous vinyl polymer dispersion PD further comprises, in ii) one or more selected from the group consisting of the monomer mixture: - one acid-functional ethylenically unsaturated monomer M1"'; - one or more ethylenically unsaturated monomers M4"' having functional groups for crosslinking during film formation other than M1"'; and - one or more polyfunctional ethylenically unsaturated monomers M5"' for pre-crosslinking, in an amount of less than 5 wt%. Claim 4 In claim 1, an aqueous vinyl polymer dispersion PD in which the weight ratio of vinyl polymers P1, P2, and P3 is contained within the range of (1:1:98) to (65:15:20). Claim 5 An aqueous vinyl polymer dispersion PD according to claim 1, wherein vinyl polymer P1 has a number average molecular weight of 2,000 to 120,000 g / mole determined by size exclusion chromatography using polystyrene standards with tetrahydrofuran and 2% acetic acid as eluents, an acid value of 30 to 150 mg KOH / g as determined by ISO 3682, and 5 to 25 wt% of an ethylenically unsaturated monomer M2 selected from the group consisting of polyethylene oxide or monoalkoxypolyethylene glycol (meth)acrylate relative to the total weight of vinyl polymer P1. Claim 6 In claim 1, an aqueous vinyl polymer dispersion PD having a number average molecular weight Mn of 1,000 to 50,000 g / mole as determined by gel permeation chromatography using hexafluoro-iso-propanol as the eluent and a polymethyl methacrylate standard for the calibration curve. Claim 7 In claim 1, an aqueous vinyl polymer dispersion PD comprising 80% or more of a monomer M3' having a monomer glass transition temperature Tg of less than 120°C, wherein the vinyl polymer P2. Claim 8 In claim 1, an aqueous vinyl polymer dispersion PD in which vinyl polymer P2 is a copolymer of N-vinyl pyrrolidone and ethyl acrylate or a copolymer of N-vinyl caprolactam and ethyl acrylate. Claim 9 In claim 1, the aqueous vinyl polymer dispersion PD having an acid value of 45 mg KOH / g or higher, wherein the water-soluble or water-dispersible crosslinkable vinyl oligomer OL. Claim 10 In claim 1, an aqueous vinyl polymer dispersion PD having a number average molecular weight of 500 to 50,000 g / mole as determined by size exclusion chromatography using tetrahydrofuran and 2% acetic acid as eluents and a polystyrene standard for the calibration curve, wherein the aqueous or water-dispersible crosslinkable vinyl oligomer OL. Claim 11 In claim 1, the aqueous vinyl polymer dispersion PD having a glass transition temperature (Tg) in the range of 10 to 150 °C, wherein the water-soluble or water-dispersible crosslinkable vinyl oligomer OL. Claim 12 In claim 1, the aqueous vinyl polymer dispersion PD, wherein the high molecular weight vinyl polymer P4 has a glass transition temperature of -70 ℃ to 50 ℃ and is at least 25 ℃ lower than the glass transition temperature of a water-soluble or water-dispersible crosslinkable vinyl oligomer OL. Claim 13 In claim 1, an aqueous vinyl polymer dispersion PD having a number average molecular weight of 60,000 g / mole or more of high molecular weight vinyl polymer P4. Claim 14 In claim 1, the film-forming vinyl polymer P3 is in the form of an aqueous polymer dispersion, and the aqueous vinyl polymer dispersion PD comprises 20 to 60 wt% of water-soluble or water-dispersible crosslinkable vinyl oligomer OL. Claim 15 In claim 14, the aqueous dispersion of vinyl polymer P3 is an aqueous vinyl polymer dispersion PD having a solid content in the range of 20 to 60 wt%. Claim 16 An aqueous vinyl polymer dispersion PD used to increase the open time, wet edge time, and / or hardness of a coating composition in any one of claims 1 to 15. Claim 17 A coating composition COA comprising an aqueous vinyl polymer dispersion PD according to any one of claims 1 to 15, and at least one component selected from non-vinyl polymers, pigments, dyes, emulsifiers, surfactants, plasticizers, thickeners, heat stabilizers, leveling agents, anti-cratering agents, fillers, sedimentation inhibitors, UV absorbers, antioxidants, desiccant salts, organic cosolvents, and wetting agents, or mixtures thereof. Claim 18 A method for preparing a coating composition COA according to claim 17, comprising combining an aqueous vinyl polymer dispersion PD with at least one component selected from a non-vinyl polymer, a pigment, a dye, an emulsifier, a surfactant, a plasticizer, a thickener, a heat stabilizer, a leveling agent, an anti-cratering agent, a filler, a sedimentation inhibitor, a UV absorber, an antioxidant, a drying agent, a salt, an organic cosolvent, and a wetting agent, or a mixture thereof.

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