WO2020225822A1

WO2020225822A1 - Aqueous polymer composition

Info

Publication number: WO2020225822A1
Application number: PCT/IN2020/050392
Authority: WO
Inventors: Girish MIRCHANDANI; Subhradeep CHAKRABORTY; Aditi BIJANI; Lipi JAIN; Subarna Shyamroy
Original assignee: Asian Paints Limited
Priority date: 2019-05-03
Filing date: 2020-04-30
Publication date: 2020-11-12

Abstract

An aqueous polymer composition comprises reaction products of an alkyl ester of acrylic or methacrylic acid monomer, a hydroxylated alkyl ester of acrylic or methacrylic acid monomer, a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer, and a water miscible co-solvent present in less than 10% by weight of the aqueous polymer composition, an epoxy silane monomer/oligomer and a tertiary amine and a primary/secondary amine. The hydroxylated alkyl ester of acrylic or methacrylic acid monomer and hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer are in a ratio 99.5:0.5 to 92:8 by weight. The tertiary amine and the primary/secondary amine are in a ratio of 20:80 to 100:0 by weight.

Description

AQUEOUS POLYMER COMPOSITION

FIELD

[0001] The invention is generally directed to a composition, more in particular to an aqueous polymer composition used in self and easy cleaning clear coatings.

BACKGROUND

[0002] Polyurethane chemistry is used for a variety of applications such as coatings, sealants, foams and adhesives. Various polyols (acrylic, polyester, polyether, polycarbonate, alkyd etc.) may be dispersed in water and cured using conventional polyisocyanates or hydrophilically modified polyisocyanates to form polyurethanes. There are potentially several coating applications such as self-cleaning and easy cleaning coatings with anti-graffiti performance, good dirt pickup resistance and cleanability. Other applications include high performance industrial coatings, floor coatings and automotive coatings.

[0003] To prepare aqueous acrylic polymers with high hydroxyl value (> 150 mg KOH/g), water reducible acrylic polymers are made with high contents of co-solvents (>10%) to enable a controlled reaction (to avoid an exotherm) and to achieve a shelf stability. To attain a resin with a low VOC, the high content of solvent needs to be stripped out under vacuum thereby increasing the cycle time of the reaction.

[0004] Alternatively, bulky specialty monomers such as isobornyl methacrylate or specialty initiators such as ditertiary amyl peroxide or specialty solvents such as methyl amyl ketone are used to impart low viscosity and prepare high solid polymers. The use of specialty chemicals increases the cost of coatings. Further, to achieve architectural self and easy cleaning clear coatings, silicone, fluoro, fluorosilicone based binders and additives are conventionally used increasing the cost of the coatings.

[0005] Water borne coatings with a high crosslinking density have a tendency to blister when immersed in water for a period of 7 days. Further, water-reducible polymers with low co-solvent contents have a tendency to pick up viscosity when stored for extended periods of time at elevated temperatures of 55 °C.

[0006] Thus, there is a need for a cost effective water based acrylic polyol resin that has a good storage stability with less than 10% viscosity pickup and that can form a self-cleaning coating with resistance to blistering when immersed in water. The process of making such acrylic polyol resin has to use low contents of solvents without a need to strip out the solvents under vacuum.

SUMMARY

[0007] Briefly, according to an example embodiment, an aqueous polymer composition comprises reaction products of an alkyl ester of acrylic or methacrylic acid monomer, a hydroxylated alkyl ester of acrylic or methacrylic acid monomer, a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer, along with a water miscible co-solvent present in less than 10% by weight of the aqueous polymer composition, an epoxy monomer or oligomer and a tertiary amine and a primary/secondary amine. The hydroxylated alkyl ester of acrylic or methacrylic acid monomer and hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer are in a ratio 99.5:0.5 to 92:8 by weight. The tertiary amine and the primary/secondary amine are in a ratio of 20:80 to 100:0 by weight. The aqueous polymer composition has a total hydroxyl value in a range of 150 mg KOH/g to 250 mg KOH/g on solids, an acid value in a range of 5 to 35mg KOH/g on solids, and a solid content of 35 to 60% by weight of the aqueous polymer composition.

[0008] According to another example embodiment, a coating comprises an aqueous polymer composition and a hydrophilized poly-isocyanate. The aqueous polymer composition comprises reaction products of an alkyl ester of acrylic or methacrylic acid monomer, a hydroxylated alkyl ester of acrylic or methacrylic acid monomer, a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer, along with a water miscible co-solvent present in less than 10% by weight of the aqueous polymer composition, an epoxy silane monomer or oligomer, and a tertiary amine and a primary/secondary amine. The hydroxylated alkyl ester of acrylic or methacrylic acid monomer and hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer are in a ratio 99.5:0.5 to 92:8 by weight. The tertiary amine and the primary/secondary amine are in a ratio of 20:80 to 100:0 by weight. The aqueous polymer composition has a total hydroxyl value in a range of 150 mg KOH/g to 250 mg KOH/g on solids, an acid value in a range of 5 to 35mg KOH/g on solids, and a solid content of 35 to 60% by weight of the aqueous polymer composition. The aqueous polymer composition and the hydrophilized poly-isocyanate are in a molar ratio of 1 :0.7 to 1:2.

[0009] According to another example embodiment, a process for forming a coating includes charging a solvent into a reactor and heating to a temperature of about 60 to 90°C under stirring, adding a mixture of monomers and a first amount of initiator to the reactor over a period of 3 to 8 hours at a temperature of 60 to 90 °C, adding a second amount of initiator and polymerizing the monomers, neutralizing contents of the reactor using an amine neutralizer and dispersing into water, continuing polymerization for an additional period of 1 to 4 hours to form an acrylic polyol, and curing the acrylic polyol with a cross-linker to form the coating.

BRIEF DESCRIPTION OF THE FIGURES

[0010] These and other features, aspects, and advantages of the example embodiments will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a plot of Total stain rating versus monomer/additive.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0011] This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope.

[0012] Polyurethane chemistry is versatile and has attracted various markets like foams, adhesives, sealants, and coatings because of its easily controllable properties. Various polyols may be dispersed in water and cured with polyisocyanates to make water borne polyurethane coatings.

[0013] Embodiments of the present invention relate to an aqueous polymer composition (acrylic polyols) and a coating including the aqueous polymer composition. Crosslinked coatings, formed by incorporating a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid in an acrylic polyol, have excellent water resistance and eliminate the blistering tendency when dipped in water for a period of 7 days. The coatings have a good accelerated storage stability at 55°C continuously over a period of 60 days with less than 10% viscosity pickup with low contents of co-solvents. Further, there is no requirement of solvent stripping during the synthesis of the aqueous polymer composition. Addition of epoxy silane oligomers or monomers during polymerization result in coatings with improved crosslinking density and easy cleaning property.

[0014] The coating enables removal of mud and dirt stains by rain water cleaning. There is no requirement of manual intervention to clean the stains. Further, there is no requirement of specialty acrylic monomers such as isobornyl methacrylate, specialty amyl initiators such as ditertiary amyl peroxide, or specialty solvents such as methyl amyl ketone to impart low viscosity and high solid polymers. Conventional acrylic monomers, initiators and water miscible solvents may be used to prepare the acrylic polyols.

[0015] In an embodiment, an economical water based easy cleaning coating with low contents of co-solvents (<10%) is disclosed. Incorporation of hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid (0.5 to 5% by weight) in acrylic polyols (acrylic polymers containing hydroxyl functionality, OH value 150 to 250 mg KOH/g) provides a facile route to improve the easy cleaning property of polymers. The hydrophilicity imparted by the hydroxylated polyalkoxyalkyl esters improved the dirt cleanability of the coating. The acrylic polyols containing the hydroxylated polyalkoxyalkyl esters of acrylic or methacrylic acid upon curing with water compatible polyisocyanates impart improved blistering resistance and water resistance to the coatings with good dirt cleaning properties.

[0016] Further, in an embodiment, the acrylic polyols are made with a low co-solvent content of 2 to 9% by weight. The acrylic polyol is synthesized using free radical polymerization using a low content of a water miscible co-solvent. The acrylic polyol is neutralized and dispersed into water either partially or fully using amine neutralizers either after the polymerization is 100% complete or any time between 40 to 100% of the completion of the polymerization thereby eliminating need for solvent stripping and enabling low VOC coatings to be made. This process also enables ease of processing without rapid temperature rise during polymerization (exotherm control) while allowing use of low contents of organic solvents.

[0017] Various esters of acrylic and methacrylic acid such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, cyclohexyl, n-octyl, 2- ethylhexyl, lauryl, isobornyl or any combinations thereof may be used to form the acrylic polyol.

[0018] Hydroxyl functional monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, their methacrylates or any combinations thereof may also be used. Hydroxyl or alkoxy functional derivatives of polyethyleneglycolmethacrylate or polypropyleneglycol methacrylate or their acrylates may also be used. Hydroxyl functional derivatives are preferred.

[0019] Vinyl monomers such as styrene, alpha-methyl styrene, para-methyl styrene, or any combination thereof may be used to form the acrylic polyol.

[0020] Carboxyl functional monomers such as acrylic acid, methacrylic acid, fumaric acid, crotonic acid, itaconic acid, maleic acid, cinnamic acid, 2-acrylamide-2-methylpropanesulfonic acid may be used.

[0021] Optionally, fluorinated monomers with fluoroalkyl groups with 1 carbon to 16 carbons such as trifluoroethyl methacrylate and tridecafluorooctylmethacrylate may be used to form the acrylic polyol. Silane or siloxane functional monomers such as vinyl alkyltrialkoxysilane, 3- methacryloxypropyltrimethoxysilane, polydimethylsiloxane functional acrylates or methacrylates may also be used.

[0022] The acrylic polyol has a glass transition temperature (Tg) of -50 to +50 °C and a number average molecular weight of 1000 to 30000. The acrylic polyol has a hydroxyl value of 150 to 250 mg KOH/g on solids, an acid value of 5 to 35 mg KOH/g on solids, and a solid content of 35 to 60% by weight of the aqueous polymer composition. In some embodiments, the acrylic polyol binder has a hydroxyl value of 150 to 200 mg KOH/g on solids, an acid value of 10 to 25 mg KOH/g on solids, and a solid content of 40 to 50% by weight of the aqueous polymer composition. [0023] In an embodiment, the aqueous polymer composition comprises a water miscible co solvent present in less than 10% by weight of the aqueous polymer composition. The tertiary amine and the primary/secondary amine are in a ratio of 20:80 to 100:0 by weight. In another embodiment, the aqueous polymer composition comprises a water miscible co-solvent present in less than 7% by weight of the aqueous polymer composition. The tertiary amine and the primary/secondary amine are in a ratio of 50:50 to 100:0 by weight.

[0024] In an embodiment, the acrylic polyol comprises a hydroxylated alkyl ester of acrylic or methacrylic acid monomer and a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer present in a specific ratio 99.5:0.5 to 92:8 by weight. In some embodiments, the acrylic polyol comprises a hydroxylated alkyl ester of acrylic or methacrylic acid monomer and a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer present in a specific ratio 99: 1 to 95:5 by weight.

[0025] The polymerization may be carried out using free radical polymerization thermal initiators. The initiator may be azobisisobutyronitrile, tertiary-butyl perbenzoate, dimethyl 2,2'- azobis(2-methylpropionate), ditertiary butyl peroxide, dicumyl peroxide, ditertiary amylperoxide, or any combination thereof. Other initiator systems such as redox polymerization initiators may also be used such as benzoyl peroxide/amine systems.

[0026] The acrylic polyol may be neutralized using a neutralizing agent. The neutralizing agent is either a tertiary amine or a combination of a tertiary amine and a primary or a secondary amine in a ratio of 20: 80 to 100: 0 to each other. The tertiary amine is either an amine or an aminoalcohol. Examples of neutralizers include dimethyl ethanolamine, N-methylethanolamine, monoethanolamine, triethylamine and morpholine. Other neutralizers such as liquor ammonia, sodium hydroxide or potassium hydroxide may also be used.

[0027] The acrylic polyol may be synthesized in a water miscible solvent such as glycol ethers of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol or any combinations thereof. Examples include ethylene glycol butyl ether, propylene glycol propyl ether and diethylene glycol monobutyl ether. Other solvents such as esters, ethers and ketones may also be used. The water miscible co-solvents may be present in a range of 2-9% by weight of the acrylic polyol aqueous composition. [0028] The acrylic polyol, according to one or more embodiments of the disclosure, has an accelerated storage stability at 55 °C continuously over a period of 60 days with a less than 10% rise in viscosity. The aqueous resin may be cured with poly-isocyanate or amino resin crosslinkers to form coating compositions.

[0029] The acrylic polyol may be cured with a curing agent selected from the group consisting of poly isocyanate (aliphatic, aromatic, cycloaliphatic) and amino resins such as melamine- formaldehyde and urea formaldehyde.

[0030] The coating composition may contain various additives such as co-solvents, defoamers, thickeners, pH modifiers, dispersing agents, wetting agents, coalescents, fluorosurfactants, opacifying polymers, plasticizers, pigments, extenders, colorants, freeze thaw stabilizers, buffers, fire retardants, ultraviolet radiation absorbers, organic fibre material, inorganic fiber materials, flow and levelling agents, adhesion promoters, oil repellants, water repellents and fillers.

EXAMPLES

[0031] The present invention will be described below in further detail with examples and comparative examples thereof, but it is noted that the present invention is by no means intended to be limited to these examples.

[0032] The examples below, describe the preparation of the water based acrylic polyol for two component polyurethane systems. The waterborne acrylic polyol is synthesized as described below and cured with water dispersible polyisocyanate to form a coating.

Synthesis of acrylic polyol

[0033] Acrylic monomers methyl methacrylate (MMA), 2-ethyl hexyl acrylate (2-EHA), cyclohexyl methacrylate (CHMA), methacrylic acid (MAA), hydroxyl ethyl methacrylate (HEMA) and polyethylene glycol methacrylate (with an average molecular weight of 500) were used. Azobisisobutyronitrile (AIBN) was used as an initiator. Different solvents such as Butyl cellosolve (ethylene glycol butyl ether), and Dowanol PNP (propylene glycol propyl ether), were used for the study. Easaqua XL600 (water dispersible aliphatic polyisocyanate with NCO content of approximately 20%) was procured from Vancorex. Experiment 1

[0034] 8 parts by weight of Butyl Cellosolve (ethylene glycol butyl ether) was used as a solvent in the synthesis of acrylic polyol. The solvent was taken in a reactor and heated to 90° C under stirring at 100 rpm. A mixture of monomers and an initiator as shown in Table 1 was fed to the reactor dropwise for a period of 4 hours. The resin was then neutralized with 30% by weight of N,N-dimethylethanolamine (DMEA) and 30% by weight of water after completion of monomer addition. The chaser catalyst was added after 45 minutes and the digestion continued for another 45 minutes. The resin was then neutralized with the remaining 70% DMEA and 70% water (by weight) over a period of 1 hour.

TABLE 1

Experiment 2

[0035] 7 parts by weight of solvent was used in the synthesis of acrylic polyol. The solvent was taken in the reactor and heated to 90° C under stirring at 100 rpm. A mixture of monomers and an initiator as shown in Table 2 was fed to the reactor dropwise for a period of 4 hours. After completion of 3 hours of monomer addition, 10% water (by weight) and 10% DMAE (by weight) was added while the addition of the mixture of monomer and initiator continued. The chaser catalyst was added 45 minutes after completion of the mixture of the monomers and the initiator. The digestion continued for another 45 minutes. The resin was then neutralized with the remaining 90% DMEA and 90% water (by weight) over a period of 1 hour.

[0036] Experiment 1 and 2 were carried out with 8% and 7% solvent respectively without the need to carry out the reaction with high content of solvent, thus eliminating the need for solvent stripping.

TABLE 2

Study of Easy cleaning coatings

[0037] The acrylic polyol prepared as described in Experiment 2 was used to study the easy cleaning property. Three different monomers, polyethylene glycol methacrylate, PEGMA (with an average molecular weight of 500), Tegomer V-Si-2250® (acrylated polydimethylsiloxane), and Capstone 62MA® (fluorinated acrylic monomer) and additives H-Si-2315®, Tego 5100N® were used for the study. Capstone 62MA® was procured from Dupont. H-Si-2311® and V-si-2250® were procured from Tego. Polyethylene glycol methacrylate was procured from Sigma Aldrich. H- Si-2315® is a linear organo functional polysiloxane. It is blended with the dispersion at the end of the polymerization. It is having methylol group as functional group. Tego 5100N® is hydroxyl functional silicon additive procured from Tego. It has a solid content of 50%. It is blended with the dispersion at the end of the polymerization.

[0038] A series of experiments was carried out by varying the monomers and additives to understand the impact of the various monomers on the coating properties. Five factors viz. Polyethylene glycol methacrylate PEGMA, V-Si-2250®, Capstone 62MA®, H-Si-2315®, Tego 5100N® were varied at two levels of each. The additives, H-Si-2315® and Tego 5100N®, were blended only with the dispersion after neutralization. The formulation variation is given in Table 3.

TABLE 3

[0039] After making the dispersion, glass panels were coated with the acrylic polyol to check the stain removal. The acrylic polyol dispersion was cured with the water dispersible polyisocyanate in a 1 : 1.3 molar ratio. The coatings were applied on 6 inch by 4 inch glass panels using a 150 pm applicator. Water contact angle, diiodomethane contact angle, and surface energy were checked. The surface energy and contact angle were analyzed to know the effect of monomers and additives on hydrophobicity. The results are reported in Table 4.

TABLE 4

[0040] It is evident from Table 4 that the surface energy of the coating was reduced by the presence of fluorinated and siloxane containing monomers and additives, whereas the surface energy increased by the presence of polyethylene glycol methacrylate monomer. [0041] The mud spot, rust spot, carbon black streaks, permanent marker stain were made on the glass plate to simulate the stains occurring in interior/exterior environment. The stains were allowed to dry for 24 hours and then cleaned by water and rating was given, 10 (best) 1 (poor). For the permanent marker stain, ten wipes with a muslin cloth was made to check the stain removal ability. The glass panels were dipped into water for seven days to check the blistering. After 7 days, a rating was given to blistering, 1 corresponding to higher blistering. The rating of the batches is given in Table 5.

TABLE 5

[0042] The higher the rating, the better is the easy cleaning property. The hydrophilic monomer, polyethylene glycol methacrylate, reduced the blistering significantly. The relation between total rating and each monomer/additive variation is given in FIG. 1. FIG. 1 is a plot 100 of total stain rating versus monomer/additive. Plot‘a’ is for Capstone 62MA® (fluorinated acrylic monomer), plot‘b’ is for V-Si-2250® (acrylated polydimethylsiloxane monomer), plot‘c’ is for PEGMA (polyethylene glycolmethacrylate), plot‘d’ is for H-Si-2311® (polydimethylsiloxane polyol 1), and plot‘e’ is for Tego 5100N® (polydimethylsiloxane polyol 2).

Effect of hydroxylated functional alkoxyalkyl ester monomer on dirt cleaning

[0043] Batch no. 17 and 18 were prepared using the ingredients as shown in Table 6 to study the effect of hydroxylated functional alkoxyalkyl ester monomer. PEGMA was used at 0.86 parts by weight in batch 18, whereas no PEGMA was added for batch 17. The same procedure as experiment 2 was followed to prepare the polymers. The coating was formed by curing with a water dispersible polyisocyanate in a molar ratio 1 : 1.3.

TABLE 6

[0044] The acrylic polyol (batch 17 and 18) had a non- volatile matter (NVM) of 35%, and pH of 8. The panels coated with acrylic polyols of batch 17 and 18 were exposed in the exterior environment for a period of 1 month and then washed with water. The dirt cleaning rating is given visually with 1 being the worst and 10 being the best. According to the dirt cleaning study, batch 18 that contained the hydroxylated alkoxylalkyl ester (PEGMA) monomer showed better dirt cleanability compared to batch 17.

[0045] Two more experiments were carried out and the ingredients for Experiment 3 are presented in Table 7 and the ingredients for Experiment 4 are presented in Table 8.

Experiment 3

[0046] The solvent was added to the reactor and heated under stirring at 100 rpm up to 90°C. Acrylic monomers and an initiator mix was then added to the reactor drop wise for 4 hours. The neutralizer and water (40% by weight each) was added after 3 hours of monomer addition. The acrylic polymer was digested for 1.5 hours. The resin was then neutralized with the remaining 60% water and neutralizer over a period of 1 hour. The aqueous polymer composition has a solid content of 40%, an acid value of 23 mg KOH/g, hydroxyl value of 178 mg KOH/g and a pH of 8.5. Table 7 presents the ingredients used for the experiment 3. The coating formed by curing the acrylic polyol with water dispersible polyisocyanate in a 1 : 1.3 molar ratio shows a dirt cleaning rating of 8/10 compared to a rating of 5/10 for batch 17 and 9/10 for batch 18 (Table 6).

TABLE 7

Experiment 4

[0047] The solvent was added to the reactor and heated under stirring at 100 rpm up to 90°C. Acrylic monomers and initiator mix was then added to the reactor drop wise for 4 hours. The neutralizer and water was added (30% by weight each) after 2.5 hours of monomer addition. The digestion time of the acrylic polymer was 1.5 hours. The resin was then neutralized with the remaining 70% water and neutralizer over a period of 1 hour. The aqueous polymer composition has a solid content of 40%, an acid value of 23 mg KOH/g, hydroxyl value of 168 mg KOH/g and a pH of 8.5. Table 8 presents the ingredients used for the experiment. The coating formed by curing the acrylic polyol with water dispersible polyisocyanate in a 1 : 1.3 molar ratio shows a dirt cleaning rating of 9/10 compared to a rating of 5/10 for batch 17 and 9/10 for batch 18 (Table 6).

TABLE 8

Shelf stability

[0048] An extended shelf stability is desired for aqueous polymers. Testing was carried out by keeping the sample in a 250 mL lacquered metal container at 55° C for a period of 60 days. A viscosity pickup of 10 % is considered as acceptable. Over 10% viscosity pickup is considered as unacceptable. The results are presented in Table 9.

TABLE 9

Passed: less than 10% viscosity pickup over 60 days at 55 °C.

Failed: more than 10% viscosity pickup over 60 days at 55 °C.

[0049] Effect of varying neutralizer, Extent of neutralization (%EN) and Acid Value of the polymer on stability are given in Table 10. As seen from Table 10, even with a lower content of solvent 7% in place of 12%, there was a less than 10% viscosity pickup in the aqueous acrylic polyol composition.

TABLE 10

Experiment 5

Effect of addition of an epoxy silane oligomer were studied in Experiment 5. The ingredients for Experiment 5 are presented in Table 11.

TABLE 11

[0050] The solvent was added to a clean dry round bottom flask equipped with a condenser, stirrer and charging port. The round bottom flask was heated to maintain a temperature at 90 ± 2 °C. Stirring rate was kept at 100 RPM. The initiator and the monomer mixture were added to the round bottom flask over a period of 4 hours. An aqueous solution of neutralizer, DMEA, 30% by weight, was added after completion of monomer addition. After 45 min, the chaser catalyst (AIBN) was added. The temperature of 90 ± 2 °C and the stirring speed of 100 RPM were maintained throughout the reaction. Digestion was continued for another 45 minutes. Then epoxy silane oligomer (Coatosil MP 200 from Momentive Silicones) was added and after around 30-45 min, the mixture was cooled with continuous stirring. The stirring speed was maintained at 50-100 RPM. The remaining 70% by weight of the aqueous solution of DMEA was added when the temperature reached 70°C. During neutralization, the temperature was maintained below 60°C. The stirrer speed was increased from 100 to 150 RPM slowly as the neutralization progressed. After 15 - 20 minutes, dispersion was checked for percentage solids and was discharged. The acrylic polyol dispersion was then cured with the water dispersible polyisocyanate in a 1 : 1.3 molar ratio to form a coating. 0.4% Epoxy silane oligomer were co- blended with the aqueous acrylic ionomer which improves QUV resistance and easy cleaning properties of the film by affecting curing performance of the cured film. The properties of the coating with and without the epoxy silane monomer are given in Table 12.

TABLE 12

[0051] As can be seen from Table 12, the stain cleaning rating improved due to the increase in the cross linking density from 8.06xl0 ⁴ to 9.07 x 10 ⁴ as determined by Dynamic Mechanical Analysis (DMA), without and with the epoxy silane monomer. In addition, there was an increase in the initial gloss from 55 to 66 units at 60° and improvement in the QUV A (333 nm) accelerated weathering test where a lower color change (DE) of 6.14 was obtained compared to 7.26 for the blank.

[0052] The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0053] While various compositions, methods, and devices are described in terms of “comprising” various components or steps (interpreted as meaning“including, but not limited to”), the compositions, methods, and devices can also“consist essentially of’ or“consist of’ the various components and steps, and such terminology should be interpreted as defining essentially closed- member groups.

[0054] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0055] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as“including but not limited to,” the term“having” should be interpreted as“having at least,” the term“includes” should be interpreted as“includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases at least one and“one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles“a” or“an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases one or more or at least one and indefinite articles such as“a” or an (e.g., “a” and/or“an” should be interpreted to mean“at least one” or“one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of“two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to“at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g.,“a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to“at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g.,“a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase“A or B” will be understood to include the possibilities of“A” or“B” or“A and B.”

[0056] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0057] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as“up to,”“at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

[0058] Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.

[0059] While only certain features of several embodiments have been illustrated, and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of inventive concepts.

[0060] The afore mentioned description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the example embodiments is described above as having certain features, any one or more of those features described with respect to any example embodiment of the disclosure may be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described example embodiments are not mutually exclusive, and permutations of one or more example embodiments with one another remain within the scope of this disclosure.

Claims

1. An aqueous polymer composition, the composition comprising: reaction products of an alkyl ester of acrylic or methacrylic acid monomer; a hydroxylated alkyl ester of acrylic or methacrylic acid monomer; and a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer;

a water miscible co-solvent present in less than 10% by weight of the aqueous polymer composition;

an epoxy silane monomer/oligomer; and

a tertiary amine and a primary/secondary amine,

wherein the hydroxylated alkyl ester of acrylic or methacrylic acid monomer and hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer are in a ratio 99.5:0.5 to 92:8 by weight, wherein the tertiary amine and the primary/secondary amine are in a ratio of 20:80 to 100:0 by weight, wherein the aqueous polymer composition has a total hydroxyl value in a range of 150 mg KOH/g to 250 mg KOH/g on solids, an acid value in a range of 5 to 35mg KOH/g on solids, and a solid content of 35 to 60% by weight of the aqueous polymer composition.

2. The aqueous polymer composition of claim 1 , wherein the epoxy silane monomer is present in a range of 0.1 to 3% by weight of the aqueous polymer composition.

3. The aqueous polymer composition of claim 1, wherein the aqueous polymer composition has a T_g of -50 to +50° C and a number average molecular weight of 1000 to 30000.

4. The aqueous polymer composition of claim 1 , wherein the alkyl ester of acrylic or

methacrylic acid monomer is selected from the group consisting of methyl, ethyl, n- propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl, lauryl, isobornyl or any combinations thereof.

5. The aqueous polymer composition of claim 1, wherein the hydroxylated alkyl ester of acrylic acid or methacrylic acid monomer is selected from the group consisting of hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate and

hydroxylbutyl acrylate and their corresponding methacrylates.

6. The aqueous polymer composition of claim 1 , wherein the hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer is a derivative of polyethylene glycol methacrylate or polypropylene glycol methacrylate having a hydroxyl functionality.

7. The aqueous polymer composition of claim 1, wherein the hydroxylated polyalkoxyalkyl ester of acrylic acid or methacrylic acid monomer is selected from the group consisting of hydroxyl-ethoxyethyl acrylate, hydroxyl-poly(ethoxy)ethyl acrylate, hydroxyl- propoxyethlyl acrylate and hydroxyl-poly(propoxy)ethyl acrylate and their corresponding methacrylates.

8. The aqueous polymer composition of claim 1, wherein the hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer has a chain length of 2-20 units.

9. The aqueous polymer composition of claim 1, wherein the water miscible co-solvent is a glycol ether, alcohol, ester, ketone, ether or their mixture and is present in a range of 2-9% by weight of the aqueous polymer composition.

10. The aqueous polymer composition of claim 1, wherein the tertiary amine is an amine or an amino alcohol, and wherein the amino alcohol is dimethyl ethanolamine, and the amine is trimethylamine.

11. The aqueous polymer composition of claim 1 , wherein the composition has an

accelerated storage stability at 55°C continuously over a period of 60 days with a less than 10% rise in viscosity.

12. A coating comprising: an aqueous polymer composition; and

a hydrophilized poly-isocyanate, wherein the aqueous polymer composition comprises reaction products of an alkyl ester of acrylic or methacrylic acid monomer;

a hydroxylated alkyl ester of acrylic or methacrylic acid monomer;

a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer,

an epoxy silane monomer/oligomer; and

a tertiary amine and a primary/secondary amine,

13. The coating of claim 12, wherein the epoxy silane monomer is present in a range of 0.1 to 3% by weight of the aqueous polymer composition.

14. The coating of claim 12, wherein the aqueous polymer composition and the hydrophilized poly-isocyanate are in a molar ratio of 1:0.7 to 1:2.

15. The coating of claim 12, wherein the coating is an anti-graffiti coating, a self-cleaning coating, an easy cleaning coating, an industrial high performance coating, a floor coating or an automotive coating.

16. The coating of claim 12, further comprising a curing agent selected from the group

consisting of poly isocyanate, melamine-formaldehyde and urea formaldehyde.

17. The coating of claim 12, further comprising at least one catalyst selected from the group consisting of dibutyltin dilaurate, dibutyltin diacetate, titanium 5 tetrabutoxide, 1,4- diazabicyclo[2,2,2]-octane, metal dionate complex, isooctate salts of Co, Zn, Bi, 2- ethylhexoate salts of Co, Zn, Bi, and Zn and Ti acetoacetate complexes and acid catalysts such as para-toluenesulfonic acid, dodecylbenzenesulfonic acid.

18. The coating of claim 17, wherein the at least one catalyst is in a range of 0.05- to 0.3% by weight.

19. The coating of claim 12, wherein the coating is a film forming coating.

20. The coating of claim 12, further comprising various additives such as co-solvents,

defoamers, thickeners, pH modifiers, dispersing agents, wetting agents, coalescents, fluorosurfactants, opacifying polymers, plasticizers, pigments, extenders, colorants, freeze thaw stabilizers, buffers, fire retardants, ultraviolet radiation absorbers, organic fibre material, inorganic fiber materials, flow and levelling agents, adhesion promoters, oil repellants, water repellents and fillers.

21. The coating of claim 12, wherein the coating is applied by a spray, a brush, or by dip coating at a dry film thickness ranging from I pm to 75 pm on metal, concrete, plastic, plaster, ceramic and glass substrates.

22. A process for forming a coating, the process comprising: charging a solvent into a reactor and heating to a temperature of about 60 to 90°C under stirring;

adding a mixture of monomers and a first amount of initiator to the reactor over a period of 3 to 8 hours at a temperature of 60 to 90°C;

adding a second amount of initiator and polymerizing the monomers;

adding an epoxy silane monomer/oligomer;

neutralizing contents of the reactor using an amine neutralizer and dispersing into water; continuing polymerization for an additional period of 1 to 4 hours to form an acrylic polyol; and

curing the acrylic polyol with a cross-linker to form the coating.

23. The process of claim 22, wherein adding the epoxy silane monomer/oligomer is carried out either after neutralizing the contents of the reactor.

24. The process of claim 22, wherein the monomers comprise an alkyl ester of acrylic or methacrylic acid monomer; a hydroxylated alkyl ester of acrylic or methacrylic acid monomer; and a hydroxylated polyalkoxyalkyl ester of acrylic or methacrylic acid monomer.

25. The process of claim 22, wherein the cross-linkers are polyisocyanates and amino resins.