DESC:FIELD
The present disclosure relates to a coating composition and a process for its preparation.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used, indicate otherwise.
Gloss: The term “gloss” is a visual impression that depends on the surface texture. Particularly, gloss is an optical property which indicates how well a surface reflects light in a specular (mirror-like) direction.
Pencil hardness test: The term “pencil hardness test” also known as “Wolff-Wilborn test” refers to an evaluation method that is performed to determine the hardness of a material, typically for coating materials. To perform a pencil hardness test, graphite pencils of varying hardness are moved across a coating surface.
5H Pencil Hardness: The term “pencil hardness test” refers to an ability of a coated surface to resist scratching or indentation when subjected to a pencil with a hardness rating of 5H on the pencil hardness scale. In this scale, pencils are graded from softest (9B) to hardest (9H), with "H" indicating the level of hardness.
Tack-free time: The term “tack free time” refers to the period required for a freshly applied coating to dry enough to the point where it no longer feels sticky or tacky to the touch.
Kinetic control additive: The term “kinetic control additive” refers to the substance that regulates the rate of chemical reactions during curing or drying, helping to control the film formation, curing speed, and overall performance of the coating.
Pot life enhancer: The term “pot life enhancer” refers to the additive used in two component coating system to extend the time of the mixed material which remains workable before it cures, allowing it for more application time.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Conventionally, there are many 2K (2 component) thermoset coating compositions such as polyurethane based coating composition, amino resin based coating composition and the like are available for coating on an interior and exterior part of the infrastructure. However, these conventional coating compositions are associated with certain drawbacks such as handling of hazardous raw materials such as isocyanates and formaldehyde. Moreover, the isocyanates and formaldehyde are not safe and toxic to environment and living organisms.
Furthermore, pencil hardness of the conventional polyurethane based or amino resin based coating composition is comparatively poor. The conventional polyurethane based or amino resin based coating compositions require comparatively more drying time.
Therefore, there is felt a need to provide a coating composition that obviates the drawbacks mentioned hereinabove or at least provide an alternative solution.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
It is an object of the present disclosure is to ameliorate one or more problems of the background or to at least provide a useful alternative.
Another object of the present disclosure is to provide a coating composition.
Still another object of the present disclosure is to provide a two-component coating composition.
Yet another object of the present disclosure is to provide an isocyanate free coating composition.
Still another object of the present disclosure is to provide an amino resin free coating composition.
Yet another object of the present disclosure is to provide a coating composition that has excellent visual gloss.
Still another object of the present disclosure is to provide a coating composition that provides 5H pencil hardness to the coating or film.
Yet another object of the present disclosure is to provide a coating composition that provides longer pot life and fast drying.
Still another object of the present disclosure is to provide an environment friendly coating composition.
Yet another object of the present disclosure is to provide a process for the preparation of a two-component coating composition.
Still another object of the present disclosure is to provide a simple, efficient and environment friendly process for the preparation of a coating composition.
Yet another object of the present disclosure is to provide a process for the preparation of a coating composition that is commercially scalable.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY
The present disclosure relates to a two-component coating composition and a process for its preparation.
In an aspect, the present disclosure provides a two-component coating composition.
The two-component coating composition comprising:
i. a first component comprising
• a reaction product of a malonated polyester and at least one polyacrylate;
• at least one additive selected from the group consisting of a kinetic control additive, a pot life enhancer and a flow and levelling additive; and
• at least one fluid medium; and
ii. a second component comprising a catalyst.
The first component and the second component are mixed before application.
The malonated polyester is a reaction product of at least one polyester, a predetermined amount of at least one active methylene compound and an anti-oxidant.
The polyester is a reaction product of polyols and a polyacid.
The polyols are selected from the group consisting of a difunctional polyol, a trifunctional polyol and a tetrafunctional polyol.
The polyacid is selected from the group consisting of isophthalic acid, adipic acid, terephthalic acid and polyacid derivative; and wherein the polyacid derivative is polyacid anhydride selected from hexahydrophthalic anhydride and phthalic anhydride.
The difunctional polyol is selected from the group consisting of neo-pentyl glycol, ethylene glycol, hexane diol, diethylene glycol, butyl ethyl propanediol, cyclohexane dimethanol and methyl propanediol.
The trifunctional polyol is selected from glycerine and trimethylolpropane.
The tetrafunctional polyol is selected from pentaerythritol and di-trimethylolpropane.
The active methylene compound is selected from the group consisting of diethyl malonate, dimethyl malonate, tert-butyl acetoacetate and ethyl acetoacetate.
The anti-oxidant is selected from the group consisting of triphenyl phosphite, hypophosphorous acid and pentaerythritol tetrakis(3-(3,5-Di-tertiary-butyl-4-hydroxyphenyl) propionate).
The polyacrylate is selected from the group consisting of urethane polyacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate and di-trimethylol propane tetraacrylate.
The ratio of -CH equivalent weight of the malonated polyester to the equivalent weight of the polyacrylate is in the range of 1:0.8 to 1:1.1.
The catalyst is selected from tetrabutylammonium methyl carbonate and tetrabutylammonium ethyl carbonate.
The kinetic control additive is selected from the group consisting of succinimide, ethylacetoacetate, 1H-benzotriazole and 1,2,4-triazole.
The pot life enhancer is selected from the group consisting of isopropanol, propylene glycol, carbitol, 2-ethyl hexanol, isobutanol and butyl cellosolve.
The flow and levelling additive is selected from silicon based flow and levelling additive, acryl-silicone hybrid and polyester; wherein the silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.
The fluid medium is selected from the group consisting of methyl ethyl ketone, butyl acetate, acetone, isopropyl alcohol, xylene and solvent naphtha.
The malonated polyester comprises,
• the predetermined amount of the active methylene compound is in the range of 15 mass% to 45 mass%;
• the predetermined amount of the anti-oxidant is in the range of 0.05 mass% to 0.5 mass%;
• the predetermined amount of the polyols is in the range of 0.3 mass% to 45 mass%; and
• the predetermined amount of the polyacid is in the range of 20 mass% to 50 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the malonated polyester.
The coating composition comprises
• the predetermined amount of the malonated polyester is in the range of 35 mass% to 45 mass%;
• the predetermined amount of the polyacrylate is in the range of 0.5 mass% to 20 mass%;
• the predetermined amount of the kinetic control additive is in the range of 3 mass% to 15 mass%;
• the predetermined amount of the pot life enhancer is in the range of 3 mass% to 15 mass%;
• the predetermined amount of the fluid medium is in the range of 5 mass% to 15 mass%;
• the predetermined amount of the flow and leveling additive is in the range of 0.2 mass% to 1 mass%; and
• the predetermined amount of the catalyst is in the range of 5 mass% to 15 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In another aspect, the present disclosure provides a process for the preparation of a two-component coating composition.
The process comprising the following steps:
a. mixing predetermined amounts of polyols, a polyacid and an anti-oxidant followed by heating to a first predetermined temperature for a first predetermined time period in an inert atmosphere to obtain a polyester;
b. cooling the polyester to a second predetermined temperature followed by adding a predetermined amount of active methylene compound and heating to a third predetermined temperature for a second predetermined time period to obtain a reaction mixture comprising malonated polyester;
c. cooling the reaction mixture comprising malonated polyester to the second predetermined temperature followed by adding a first fluid medium and further cooling to a temperature in the range of 25 oC to 35 oC to obtain a malonated polyester;
d. mixing predetermined amounts of the malonated polyester, at least one polyacrylate, a first additive and the first fluid medium under stirring at a first predetermined speed for a third predetermined time period followed by adding predetermined amounts of a second fluid medium and a second additive under stirring at a second predetermined speed for a fourth predetermined time period to obtain a homogenized mixture of a first component; and
e. adding a predetermined amount of a second component in the homogenized mixture at a fourth predetermined temperature for a fifth predetermined time period to obtain the coating composition.
The second component is added to the first component prior to use.
The polyols are selected from the group consisting of a difunctional polyol, a trifunctional polyol and a tetrafunctional polyol.
The polyacid is selected from the group consisting of isophthalic acid, adipic acid, terephthalic acid and polyacid derivative; the polyacid derivative is polyacid anhydride selected from hexahydrophthalic anhydride and phthalic anhydride.
The anti-oxidant is selected from the group consisting of triphenyl phosphite, hypophosphorous acid and pentaerythritol tetrakis(3-(3,5-Di-tertiary-butyl-4-hydroxyphenyl) propionate).
The active methylene compound is selected from the group consisting of diethyl malonate, dimethyl malonate, tert-butyl acetoacetate and ethyl acetoacetate.
The polyacrylate is selected from the group consisting of urethane polyacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate and di-trimethylol propane tetraacrylate.
The first additive is selected from kinetic control additive and pot life enhancer.
The second additive is a flow and levelling additive is selected from silicon based flow and levelling additive, acryl-silicone hybrid and polyester; wherein the silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.
The first fluid medium and the second fluid medium are independently selected from the group consisting of methyl ethyl ketone, butyl acetate, acetone, isopropyl alcohol, xylene, and solvent naphtha.
The second component is a catalyst selected from tetrabutylammonium methyl carbonate and tetrabutylammonium ethyl carbonate.
The difunctional polyol is selected from the group consisting of neo-pentyl glycol, ethylene glycol, hexane diol, diethylene glycol, butyl ethyl propanediol, cyclohexane dimethanol, and methyl propanediol.
The trifunctional polyol is selected from glycerine and trimethylolpropane.
The tetrafunctional polyol is selected from pentaerythritol and di-trimethylolpropane.
The kinetic control additive is selected from the group consisting of succinimide, ethylacetoacetate, 1H-benzotriazole and 1,2,4-triazole.
The pot life enhancer is selected from the group consisting of isopropanol, propylene glycol, carbitol, 2-ethyl hexanol, isobutanol and butyl cellosolve.
The silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.
The ratio of -CH equivalent weight of the malonated polyester to the equivalent weight of the polyacrylate is in the range of 1:0.8 to 1:1.1.
The predetermined amounts in the process for the preparation of malonated polyester comprises,
• the predetermined amount of the polyols is in the range of 0.3 mass% to 45 mass%;
• the predetermined amount of the polyacid is in the range of 20 mass% to 50 mass%;
• the predetermined amount of the active methylene compound is in the range of 15 mass% to 45 mass%; and
• the predetermined amount of the anti-oxidant is present in an amount in the range of 0.05 mass% to 0.5 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the malonated polyester.
The predetermined amounts in the process for the preparation of coating composition comprises,
• the predetermined amount of the malonated polyester is in the range of 35 mass% to 45 mass%;
• the predetermined amount of the polyacrylate is in the range of 0.5 mass% to 20 mass%;
• the predetermined amount of the first additive is in the range of 3 mass% to 15 mass%;
• the predetermined amount of the first fluid medium and the second fluid medium are independently in the range of 5 mass% to 15 mass%;
• the predetermined amounts of the second additive is in the range of 0.2 mass% to 1 mass%; and
• the predetermined amount of the second component is present in an amount in the range of 5 mass% to 15 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
The first predetermined temperature is in the range of 200 ºC to 250 ºC.
The second predetermined temperature is in the range of 100 ºC to 140 ºC.
The third predetermined temperature is in the range of 150 ºC to 200 ºC.
The fourth predetermined temperature is in the range of 25 ºC to 30 ºC.
The first predetermined time period is in the range of 10 hours to 14 hours.
The second predetermined time period is in the range of 3 hours to 6 hours.
The third predetermined time period is in the range of 10 minutes to 20 minutes.
The fourth predetermined time period is in the range of 10 minutes to 30 minutes.
The fifth predetermined time period is in the range of 2 minutes to 15 minutes.
The first predetermined stirring speed is in the range of 500 rpm to 700 rpm.
The second predetermined stirring speed is in the range of 500 rpm to 700 rpm.
The inert atmosphere is obtained by using nitrogen gas.
DETAILED DESCRIPTION
The present disclosure relates to a coating composition and a process for its preparation.
Embodiments, of the present disclosure, will now be described herein. Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units, and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer, or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Conventionally, various 2K (two-component) thermoset coating compositions such as those based on polyurethane or amino resins, are used for coating both interior and exterior parts of infrastructure. However, these conventional coating compositions come with certain drawbacks, such as the use of hazardous raw materials like isocyanates and formaldehyde, which are toxic to living organisms. Additionally, the pencil hardness of conventional polyurethane-based or amino resin-based coatings is relatively low. These coating compositions also require longer drying times.
The present disclosure provides a two-component coating composition and a process for its preparation.
In an aspect, the present disclosure provides a two-component coating composition.
The two-component coating composition comprising:
i. a first component comprising
• a reaction product of a malonated polyester and at least one polyacrylate;
• at least one additive selected from the group consisting of a kinetic control additive, a pot life enhancer and a flow and levelling additive; and
• at least one fluid medium; and
ii. a second component comprising a catalyst.
In an embodiment of the present disclosure, the first component and the second component are mixed before application.
In an embodiment of the present disclosure, the malonated polyester is a reaction product of at least one polyester, a predetermined amount of at least one active methylene compound and an anti-oxidant.
In an embodiment of the present disclosure, the polyester is a reaction product polyols and a polyacid.
In an embodiment of the present disclosure, the polyester having acid value in the range of 1 mgKOH/g to 5 mgKOH/g. In an exemplary embodiment of the present disclosure, the polyester having acid value of 3 mgKOH/g.
In accordance with the present disclosure, a lower acid value indicates that the polyacid has been sufficiently converted into the polyester.
In an embodiment of the present disclosure, the polyols are selected from the group consisting of a difunctional polyol, a trifunctional polyol and a tetrafunctional polyol.
In an embodiment of the present disclosure, the difunctional polyol is selected from the group consisting of neo-pentyl glycol, ethylene glycol, hexane diol, diethylene glycol, butyl ethyl propanediol, cyclohexane dimethanol and methyl propanediol. In an exemplary embodiment of the present disclosure, the difunctional polyols are selected from neo-pentyl glycol, ethylene glycol, diethylene glycol and methyl propanediol.
In an embodiment of the present disclosure, the trifunctional polyol is selected from glycerine and trimethylolpropane. In an exemplary embodiment of the present disclosure, the trifunctional polyol is trimethylolpropane.
In an embodiment of the present disclosure, the tetrafunctional polyol is selected from pentaerythritol and di-trimethylolpropane. In an exemplary embodiment of the present disclosure, the tetrafunctional polyol is pentaerythritol.
In an embodiment of the present disclosure, the polyacid is selected from the group consisting of isophthalic acid, adipic acid, terephthalic acid and polyacid derivative. In an exemplary embodiment of the present disclosure, the polyacid is isophthalic acid.
In an embodiment of the present disclosure, the polyacid derivative is polyacid anhydride selected from hexahydrophthalic anhydride and phthalic anhydride.
In an embodiment of the present disclosure, the anti-oxidant is selected from the group consisting of triphenyl phosphite, hypophosphorous acid and pentaerythritol tetrakis(3-(3,5-Di-tertiary-butyl-4-hydroxyphenyl) propionate) (Irganox 1010). In an exemplary embodiment of the present disclosure, the anti-oxidant is triphenyl phosphite.
In an embodiment of the present disclosure, the active methylene compound is selected from the group consisting of diethyl malonate, dimethyl malonate, tert-butyl acetoacetate and ethyl acetoacetate. In an exemplary embodiment of the present disclosure, the active methylene compound is diethyl malonate.
In an embodiment of the present disclosure, the polyacrylate is selected from the group consisting of urethane polyacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate and di-trimethylol propane tetraacrylate. In an exemplary embodiment of the present disclosure, the polyacrylates are urethane polyacrylate (Miramer PU 320) and trimethylolpropane triacrylate (Miramer M 300).
In an embodiment of the present disclosure, the polyacrylate is polyacrylate with more than one active C=C unsaturated groups.
The addition of a small amount of urethane polyacrylate to the coating composition of the present disclosure enhances its toughness due to the presence of urethane linkages. These linkages contribute to achieving 5H hardness, resulting in a more durable, scratch-resistant coating surface with improved performance and longevity.
In an embodiment of the present disclosure, the ratio of -CH equivalent weight of the malonated polyester to the equivalent weight of the polyacrylate is in the range of 1:0.8 to 1:1.1.
In accordance with the present disclosure, when the ratio of the -CH equivalent weight of malonated polyester to the equivalent weight of the polyacrylate is less than 0.8, will result in more unreacted malonated polyester leading to incomplete curing, a soft coating, and a lower pencil hardness. On the other hand, a ratio higher than 1.1 will result in excess unreacted polyacrylate in the system, causing over-curing or curing over time of polyacrylate which results in brittleness and cracking. Therefore, maintaining the ratio of the -CH equivalent weight of malonated polyester to the equivalent weight of the polyacrylate between 1:0.8 and 1:1.1 is essential for ensuring an optimal curing process. This balance is critical for achieving the coating's durability, hardness, and long-term performance.
In an embodiment of the present disclosure, the second component is catalyst selected from tetrabutylammonium methyl carbonate and tetrabutylammonium ethyl carbonate. In an exemplary embodiment of the present disclosure, the second component is tetrabutylammonium methyl carbonate. In another exemplary embodiment of the present disclosure, the second component is tetrabutylammonium ethyl carbonate.
In an embodiment of the present disclosure, the kinetic control additive is selected from the group consisting of succinimide, ethylacetoacetate, 1H-benzotriazole and 1,2,4-triazole. In an exemplary embodiment of the present disclosure, the kinetic control additive is succinimide.
The kinetic control additive plays a significant role in coating composition by regulating the curing process by controlling the reaction rate. It helps to prevent premature curing or over-curing, ensuring a more controlled, uniform film formation. By moderating the curing kinetics, kinetic control additive enhances the coating's processing time, improves film consistency, and allows for better control over the final properties, such as finish, hardness, gloss, and durability.
In an embodiment of the present disclosure, the pot life enhancer is selected from the group consisting of isopropanol, propylene glycol, carbitol, 2-ethyl hexanol, isobutanol and butyl cellosolve. In an exemplary embodiment of the present disclosure, the pot life enhancer is 2-ethyl hexanol. In another exemplary embodiment of the present disclosure, the pot life enhancer is isobutanol. Still in another exemplary embodiment of the present disclosure, the pot life enhancer is butyl cellosolve.
A pot life enhancer of the present disclosure improves the overall workability and handling of the two-component coating composition. Pot life enhancer prolong the usability of the coating after both the components have been mixed, preventing premature curing. This additive helps to avoid issues like incomplete application or waste due to premature hardening, ensuring a smoother application process, better surface quality, and optimal curing.
In an embodiment of the present disclosure, the flow and levelling additive is selected from silicon based flow and levelling additive, acryl-silicone hybrid, polyacrylate and polyester.
In an embodiment of the present disclosure, the silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.
In an embodiment of the present disclosure, the polyacrylate is selected from group consisting of fluorinated polyacrylates, long-chain alkyl acrylate copolymers, and poly(ethylene glycol) modified polyacrylates.
In an embodiment of the present disclosure, the polyester is selected from polyester-modified polysiloxanes.
In an embodiment of the present disclosure, the fluid medium is selected from the group consisting of methyl ethyl ketone, butyl acetate, acetone, isopropyl alcohol, xylene and solvent naphtha (Solvent C-IX). In an exemplary embodiment of the present disclosure, the fluid medium is a mixture of o-xylene and butyl acetate.
In an embodiment of the present disclosure, the malonated polyester comprises
• the predetermined amount of the polyols is in the range of 0.3 mass% to 45 mass%;
• the predetermined amount of the polyacid is in the range of 20 mass% to 50 mass%;
• the predetermined amount of the active methylene compound is in the range of 15 mass% to 45 mass%; and
• the predetermined amount of the anti-oxidant is in the range of 0.05 mass% to 0.5 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the malonated polyester.
In an exemplary embodiment of the present disclosure, the malonated polyester comprises,
• ethylene glycol as a difunctional polyol is 2 mass%;
• diethylene glycol as a difunctional polyol is 3 mass%;
• methyl propanediol as a difunctional polyol is 5.7 mass%;
• neo-pentyl glycol as a difunctional polyol is 20.6 mass%;
• trimethylolpropane as a trifunctional polyol is 4.9 mass%;
• pentaerythritol as a tetrafunctional polyol is 0.5 mass%;
• isophthalic acid as a polyacid is 31.7 mass%;
• diethyl malonate as an active methylene compound is 31.4 mass%; and
• triphenyl phosphite as an anti-oxidant is 0.2 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the coating composition comprises
• the predetermined amount of the malonated polyester is in the range of 35 mass% to 45 mass%;
• the predetermined amount of the polyacrylate is in the range of 0.5 mass% to 20 mass%;
• the predetermined amount of the kinetic control additive is in the range of 3 mass% to 15 mass%;
• the predetermined amount of the pot life enhancer is in the range of 3 mass% to 15 mass%;
• the predetermined amount of the fluid medium is in the range of 5 mass% to 15 mass%;
• the predetermined amount of the flow and leveling additive is in the range of 0.2 mass% to 1 mass%; and
• the predetermined amount of the catalyst is in the range of 5 mass% to 15 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.

In an exemplary embodiment of the present disclosure, the coating composition comprises
• the malonated polyester is 46.86 mass%;
• trimethylolpropane triacrylate (Miramer M 300) is 18.28 mass%;
• urethane polyacrylate (Miramer PU 320) is 1.14 mass%;
• succinimide is 10.29 mass%;
• silicon based flow and levelling additive is 0.57 mass%;
• o-xylene + butyl acetate (50:50) is 11.43 mass%;
• tetrabutylammonium methylcarbonate is 11.43 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the first component and the second component are mixed before application.
The coating composition of the present disclosure provides an excellent visual gloss, 5H pencil hardness to coating, longer pot life and fast drying.
The coating composition of the present disclosure provides synergistic effect that significantly enhance properties such as gloss, finish, tack-free time, and 5H pencil hardness of the coat applied on a wooden substrate. By optimizing the ratios of malonated polyester, polyacrylate, kinetic control additives or pot life enhancers, catalyst and other additives, the coating achieves superior gloss and smoothness, faster tack-free time, and greater durability. As a result, the coating composition of the present disclosure exhibits improved hardness, achieving a 5H pencil hardness, and provides better overall performance, including enhanced aesthetic quality and long-lasting protection.
In another aspect, the present disclosure provides a process for the preparation of the coating composition.
The process comprising the following steps:
a. mixing predetermined amounts of polyols, at least one polyacid and an anti-oxidant followed by heating to a first predetermined temperature for a first predetermined time period in an inert atmosphere to obtain a polyester;
b. cooling the polyester to a second predetermined temperature followed by adding a predetermined amount of active methylene compound and heating to a third predetermined temperature for a second predetermined time period to obtain a reaction mixture comprising malonated polyester;
c. cooling the reaction mixture comprising malonated polyester to the second predetermined temperature followed by adding a first fluid medium and further cooling to a temperature in the range of 25 oC to 35 oC to obtain a malonated polyester;
d. mixing predetermined amounts of the malonated polyester, at least one polyacrylate, a first additive, and the first fluid medium under stirring at a first predetermined speed for a third predetermined time period followed by adding predetermined amounts of a second fluid medium and a second additive under stirring at a second predetermined speed for a fourth predetermined time period to obtain a homogenized mixture of a first component; and
e. adding a predetermined amount of a second component in the homogenized mixture at a fourth predetermined temperature for a fifth predetermined time period to obtain the coating composition.
The process is described in detail.
In a first step, predetermined amounts of polyols, a polyacid and an anti-oxidant are mixed followed by heating to a first predetermined temperature for a first predetermined time period in an inert atmosphere to obtain a polyester.
In an embodiment of the present disclosure, the polyols are selected from the group consisting of a difunctional polyol, a trifunctional polyol and a tetrafunctional polyol.
In an embodiment of the present disclosure, the polyols are present in an amount in the range of 0.3 mass% to 45 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the polyols are 36.7 mass% with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the difunctional polyol is selected from the group consisting of neo-pentyl glycol, ethylene glycol, hexane diol, diethylene glycol, butyl ethyl propanediol, cyclohexane dimethanol, and methyl propanediol. In an exemplary embodiment of the present disclosure, the difunctional polyols are selected from neo-pentyl glycol, ethylene glycol, diethylene glycol and methyl propanediol.
In an embodiment of the present disclosure, the difunctional polyol is present in an amount in the range of 25 mass% to 35 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the difunctional polyol is 31.3 mass% with respect to the total mass of the malonated polyester.
In an exemplary embodiment of the present disclosure, the difunctional polyol comprises,
• ethylene glycol as a difunctional polyol is 2 mass%;
• diethylene glycol as a difunctional polyol is 3 mass%;
• methyl propanediol as a difunctional polyol is 5.7 mass%; and
• neo-pentyl glycol as a difunctional polyol is 20.6 mass%;
wherein the mass% of each ingredient is with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the trifunctional polyol is selected from glycerine and trimethylolpropane. In an exemplary embodiment of the present disclosure, the trifunctional polyol is trimethylolpropane.
In an embodiment of the present disclosure, the trifunctional polyol is present in an amount in the range of 3 mass% to 10 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the trifunctional polyol is 4.9 mass% with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the tetrafunctional polyol is selected from pentaerythritol and di-trimethylolpropane. In an exemplary embodiment of the present disclosure, the tetrafunctional polyol is pentaerythritol.
In an embodiment of the present disclosure, the tetrafunctional polyol is present in an amount in the range of 0.2 mass% to 2 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the tetrafunctional polyol is 0.5 mass% with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the polyacid is selected from the group consisting of isophthalic acid, adipic acid, terephthalic acid and polyacid derivative. In an exemplary embodiment of the present disclosure, the polyacid is isophthalic acid.
In an embodiment of the present disclosure, the polyacid derivative is polyacid anhydride selected from hexahydrophthalic anhydride and phthalic anhydride.
In an embodiment of the present disclosure, the polyacid is present in an amount in the range of 20 mass% to 50 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the polyacid is 31.7 mass% with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the anti-oxidant is selected from the group consisting of triphenyl phosphite, hypophosphorous acid and pentaerythritol tetrakis(3-(3,5-Di-tertiary-butyl-4-hydroxyphenyl) propionate) (Irganox 1010). In an exemplary embodiment of the present disclosure, the anti-oxidant is triphenyl phosphite.
In an embodiment of the present disclosure, the anti-oxidant is present in an amount in the range of 0.05 mass% to 0.5 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the anti-oxidant is 0.2 mass% with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the first predetermined temperature is in the range of 200 ºC to 250 ºC. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 230 ºC.
In an embodiment of the present disclosure, the first predetermined time period is in the range of 10 hours to 14 hours. In an exemplary embodiment of the present disclosure, the first predetermined time period is 12 hours.
In an embodiment of the present disclosure, the inert atmosphere is obtained by using nitrogen gas.
In a second step, the polyester is cooled to a second predetermined temperature followed by adding a predetermined amount of active methylene compound and heating to a third predetermined temperature for a second predetermined time period to obtain reaction mixture comprising a malonated polyester.
In an embodiment of the present disclosure, the active methylene compound is selected from the group consisting of diethyl malonate, dimethyl malonate, tert-butyl acetoacetate and ethyl acetoacetate. In an exemplary embodiment of the present disclosure, the active methylene compound is diethyl malonate.
In an embodiment of the present disclosure, the active methylene compound is present in an amount in the range of 15 mass% to 45 mass% with respect to the total mass of the malonated polyester. In an exemplary embodiment of the present disclosure, the active methylene compound is 31.4 mass% with respect to the total mass of the malonated polyester.
In an embodiment of the present disclosure, the second predetermined temperature is in the range of 100 ºC to 140 ºC. In an exemplary embodiment of the present disclosure, the second predetermined temperature is 130 ºC.
In an embodiment of the present disclosure, the third predetermined temperature is in the range of 150 ºC to 200 ºC. In an exemplary embodiment of the present disclosure, the third predetermined temperature is 190ºC.
In an embodiment of the present disclosure, the second predetermined time period is in the range of 3 hours to 6 hours. In an exemplary embodiment of the present disclosure, the second predetermined time period is 4 hours.
In a third step, the reaction mixture comprising malonated polyester is cooled to the second predetermined temperature followed by adding a first fluid medium and further cooling to a temperature in the range of 25 oC to 35 oC to obtain a malonated polyester.
In accordance with the present disclosure, the optimum CH equivalent weight of malonated polyester is necessary to obtain the coating composition with better hardness and flexibility. Further, lower the CH equivalent, higher will be the cross linking and vice-versa. However, lower crosslinking leads to softer coating and higher the crosslinking leads to brittle coating. Therefore, optimum CH equivalent weight of malonated polyester is required for optimum crosslinking for hardness and flexibility.
In a fourth step, the predetermined amounts of malonated polyester, at least one polyacrylate, a first additive and the first fluid medium under stirring at a first predetermined speed for a third predetermined time period followed by adding predetermined amounts of a second fluid medium and a second additive under stirring at a second predetermined speed for a fourth predetermined time period to obtain a homogenized mixture of a first component.
In an embodiment of the present disclosure, the malonated polyester is present in an amount in the range of 35 mass% to 45 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the malonated polyester is 46.86 mass% with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the polyacrylate is selected from the group consisting of urethane polyacrylate, trimethylolpropane triacrylate ethoxylated trimethylolpropane triacrylate and di-trimethylol propane tetraacrylate. In an exemplary embodiment of the present disclosure, the polyacrylates are urethane polyacrylate (Miramer PU 320) and trimethylolpropane triacrylate (Miramer M 300).
In an embodiment of the present disclosure, the polyacrylate is polyacrylate with more than one active C=C unsaturated groups.
In an embodiment of the present disclosure, the polyacrylate is present in an amount in the range of 0.5 mass% to 20 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the trimethylolpropane triacrylate (Miramer M 300) is 18.28 mass% and urethane polyacrylate (Miramer PU 320) is 1.14 mass% with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the ratio of -CH equivalent weight of the malonated polyester to the equivalent weight of the polyacrylate is in the range of 1:0.8 to 1:1.1.
In an embodiment of the present disclosure, a first additive is selected from a kinetic control additive and a pot life enhancer.
In one embodiment, a first additive is a kinetic control additive.
In another embodiment, a first additive is a pot life enhancer.
In an embodiment of the present disclosure, the kinetic control additive is selected from the group consisting of succinimide, ethyl acetoacetate, 1H-benzotriazole and 1,2,4-triazole. In an exemplary embodiment of the present disclosure, the kinetic control additive is succinimide.
In an embodiment of the present disclosure, the kinetic control additive is present in an amount in the range of 3 mass% to 15 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the kinetic control additive is present in an amount of 10.29 mass% with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the pot life enhancer is selected from the group consisting of isopropanol, propylene glycol, carbitol, 2-ethyl hexanol, isobutanol and butyl cellosolve. In an exemplary embodiment of the present disclosure, the pot life enhancer is 2-ethyl hexanol. In another exemplary embodiment of the present disclosure, the pot life enhancer is isobutanol. Still in another exemplary embodiment of the present disclosure, the pot life enhancer is butyl cellosolve.
In an embodiment of the present disclosure, the pot life enhancer is present in an amount in the range of 3 mass% to 15 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the pot life enhancer is present in an amount of 11.29 mass% with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the second additive is flow and levelling additive is selected from silicon based flow and levelling additive, acryl-silicone hybrid, polyacrylate and polyester.
In an embodiment of the present disclosure, the silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.
In an embodiment of the present disclosure, the polyacrylate is selected from group consisting of fluorinated polyacrylates, long-chain alkyl acrylate copolymers, and poly(ethylene glycol) modified polyacrylates.
In an embodiment of the present disclosure, the polyester is selected from polyester-modified polysiloxanes.
In an embodiment of the present disclosure, the second additive is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the second additive is present in an amount of 0.57 mass% with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the first fluid medium and the second fluid medium are independently selected from the group consisting of methyl ethyl ketone, butyl acetate, acetone, isopropyl alcohol, xylene, solvent naphtha (Solvent C-IX). In an exemplary embodiment of the present disclosure, the first fluid medium is o-xylene and the second fluid medium is butyl acetate.
In an embodiment of the present disclosure, the first fluid medium and the second fluid medium are present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the first fluid medium and the second fluid medium are present in an amount of 11.43 mass%.
In an embodiment of the present disclosure, the third predetermined time period is in the range of 10 minutes to 20 minutes. In an exemplary embodiment of the present disclosure, the third predetermined time period is 15 minutes.
In an embodiment of the present disclosure, the fourth predetermined time period is in the range of 10 minutes to 30 minutes. In an exemplary embodiment of the present disclosure, the fourth predetermined time period is 20 minutes.
In an embodiment of the present disclosure, the first predetermined stirring speed is in the range of 500 rpm to 700 rpm. In an exemplary embodiment of the present disclosure, the first predetermined stirring speed is 600 rpm.
In an embodiment of the present disclosure, the second predetermined stirring speed is in the range of 500 rpm to 700 rpm. In an exemplary embodiment of the present disclosure, the second predetermined stirring speed is 600 rpm.
In a fifth step, adding a predetermined amount of a second component in the homogenized mixture at a fourth predetermined temperature for a fifth predetermined time period to obtain a coating composition.
In an embodiment of the present disclosure, the second component is catalyst selected from tetrabutylammonium methyl carbonate and tetrabutylammonium ethyl carbonate. In an exemplary embodiment of the present disclosure, the second component is tetrabutylammonium methyl carbonate. In another exemplary embodiment of the present disclosure, the second component is tetrabutylammonium ethyl carbonate.
In an embodiment of the present disclosure, the catalyst is prepared by mixing a base and a carbonate in a third fluid medium.
In an embodiment of the present disclosure, the base is tetrabutylammonium hydroxide.
In an embodiment of the present disclosure, the carbonate is selected from dimethyl carbonate and diethyl carbonate. In an exemplary embodiment of the present disclosure, the carbonate is dimethyl carbonate.
In an embodiment of the present disclosure, the third fluid medium is selected from isopropanol and o-xylene. In an exemplary embodiment of the present disclosure, the third fluid medium is isopropanol. In another exemplary embodiment of the present disclosure, the third fluid medium is o-xylene.
In an embodiment of the present disclosure, the second component is present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the second component is present in 11.43 mass% with respect to the total mass of the coating composition.
In an embodiment of the present disclosure, the fourth predetermined temperature is in the range of 25 ºC to 30 ºC. In an exemplary embodiment of the present disclosure, the fourth predetermined temperature is 27 ºC (room temperature).
In an embodiment of the present disclosure, the fifth predetermined time period is in the range of 2 minutes to 15 minutes. In an exemplary embodiment of the present disclosure, the fifth predetermined time period is 10 minutes.
In an embodiment of the present disclosure, the second component is added to the first component prior to use.
The coating composition of the present disclosure provides a solution for isocyanate free coatings by using a Michael-type reaction. This process involves the formation of a C-C bond between the active methylene of malonated polyester (donor resin) and polyacrylates (acceptor resins) in the presence of a catalyst. As a result, the coating composition of the present disclosure provides excellent gloss and gloss retention, ceramic like hardness (5H pencil hardness) and abrasion resistance.
The process for the preparation of a coating composition of the present disclosure is simple and environment friendly.
The coating composition of the present disclosure provides an excellent visual gloss, 5H pencil hardness to coating, longer pot life and fast drying.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Experiment 1: Process for the preparation of the coating composition in accordance with the present disclosure
Process for the preparation of a malonated polyester (MPE) in accordance with the present disclosure.
The preparation of a malonated polyester was carried out in a reactor provided with a distilling column filed with Raschig rings and dean-stark. Dean stark was used for effective removal of water and ethanol generated during reaction and rasching rings were used to avoid the polyol losses.
General procedure: The predetermined amounts of ethylene glycol, diethylene glycol, methyl propanediol, neopentyl glycol, trimethylol propane, pentaerythritol, isophthalic acid and triphenyl phosphite were charged into the four neck reactor followed by heating to 230 ºC (first predetermined temperature) for 12 hours (first predetermined time period) in a nitrogen gas atmosphere to obtain a polyester.
The polyester having acid value of in the range of 3 mgKOH/g.
The polyester cooled to 130 ºC (second predetermined temperature) followed by adding a predetermined amount of diethyl malonate and heated to 190 ºC (third predetermined temperature) for 4 hours (second predetermined time period) to obtain a reaction mixture comprising malonated polyester. Finally, ethanol was removed under reduced pressure.
The reaction mixture was further cooled to 120ºC and diluted with O-xylene to 70% solids to yield malonated polyester. The obtained malonated polyester was further cooled to 27°C.
The malonated polyesters P1 to P3 were prepared by following the general procedure as above. The predetermined amounts of the specific ingredients are as given in table 1.
Ingredients and their function P1 P2 P3
Sr. no. Materials Function Weight in grams Weight in grams Weight in grams
1. Ethylene glycol Difunctional polyol 2 2 2
2. Diethylene glycol Difunctional polyol 3 3 3
3. Methyl propanediol Difunctional polyol 5.2 5.7 5.2
4. Neopentyl glycol Difunctional polyol 22.9 20.6 20.7
5. Trimethylol propane Trifunctional polyol 5.1 4.9 6.2
6. Pentaerythritol Tetrafunctional polyol 0.5 0.5 0.7
7. Isophthalic acid polyacid 40.1 31.74 22.7
8. Diethyl Malonate Ethyl ester
(Active methylene compound) 21.0 31.4 39.3
9. Triphenyl phosphite Anti-oxidant 0.2 0.2 0.2
Total 100 100 100
-CH Equivalent Weight @ 70% NVM 413 273 211
From table 1, it is observed that the malonated polyesters P1 to P3 have the CH equivalent weight 413, 273 and 211, respectively.
It is to be noted that lower the CH equivalent, higher will be the cross linking and higher the CH equivalent, lower will be the cross linking. The lower crosslinking leads to softer coating and higher the crosslinking leads to brittle coating. Therefore, the optimum CH equivalent of the malonated polyester is required for optimum crosslinking for achieving desirable hardness and flexibility.
Thus, the malonated polyester, P2 having suitable CH equivalent weight which provides the optimum crosslinking is used in the preparation of coating composition of the present disclosure and studied further for the properties obtained therefrom.
Process for the preparation of a coating composition in accordance with the present disclosure.
General procedure: The predetermined amounts of malonated polyester (P2), Miramer M300, Miramer PU 320, first additive (a kinetic control additive or pot life enhancer) and o-xylene (first fluid medium) in a stain-less steel container under stirring at 600 rpm (first predetermined speed) for 15 minutes (third predetermined time period) followed by adding predetermined amounts of butyl acetate (second fluid medium) and a flow and leveling additive (second additive) under stirring at 600 rpm (second predetermined speed) for 20 minutes (fourth predetermined time period) to obtain a homogenized mixture of a first component.
A predetermined amount of a catalyst (C1 or C2) (second component) was added to the homogenized mixture at a 27 oC (room temperature) (fourth predetermined temperature) for 10 minutes (fifth predetermined time period) to obtain a coating composition.
A ratio of -CH equivalent weight of the malonated functional polymer component and polyacrylate equivalent weight of the Miramer component is 1:1.
The coating composition were prepared in Examples 1 to 10 (E1 to E10) by following the general procedure as above. The predetermined amounts of the specific ingredients of the coating composition are given in Table 2.
Process for the preparation of the catalyst in accordance with the present disclosure
Process for the preparation of a catalyst tetrabutylammonium methylcarbonate (C1)
30 g of a 40 % solution of tetrabutylammonium hydroxide (46.0 mmole base) in isopropanol was mixed with 45 g dimethyl carbonate. After decantation of some precipitate, a clear solution was obtained.
Process for the preparation of a catalyst tetrabutylammonium methylcarbonate (C2)
30 g of a 40 % solution of tetrabutylammonium hydroxide (46.0 mmole base) in ortho-xylene was mixed with 45 g dimethyl carbonate. After decantation of some precipitate, a clear solution was obtained.
Table 2: Coating compositions prepared in accordance with the present disclosure
Ingredients and their function E1
E2
E3 E4 E5 E6 E7 E8 E9 E10
Sr. no. Materials Function
PART A: First component
1. Malonated Polyester P2 Donor Resin 41 41 41 41 41 41 41 41 41 41
2. Miramer M 300
(trimethylolpropane triacrylate) Acceptor Resin 16 16 16 16 16 16 16 16 16 16
3. Miramer PU 320
( Urethane polyacrylate) Acceptor Resin (hardness) 1 1 1 --- 1 1 1 1 1 1
4. 10% Succinimide solution in acetone Kinetic control additive -- 4.5 9 9 9 9 --- --- ---
---
5. 2-Ethyl Hexanol Pot life enhancer --- --- --- --- --- --- 5 10 --- ---
6. Isobutanol Pot life enhancer --- --- --- --- --- --- --- --- 10 ---
7. Butyl Cellosolve Pot life enhancer --- --- --- --- --- --- --- --- --- 5
8. Silicon based flow and levelling Additive Flow and levelling additive 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

9. O-xylene + butyl acetate (50:50) Fluid medium 10 10 10 10 10 10 10 10 10 10
PART B: Second Component
10. Catalyst (C1) Catalyst 10 10 10 10 5 7 --- --- --- ---
11. Catalyst (C2) Catalyst --- --- --- --- --- --- 10 10 10 10
For the sake of brevity, multiple number of experiments are not included in the specification. However, the other ingredients having similar functionality can be used in the preparation of the coating composition of the present disclosure and the coating composition will give similar results.
The coating compositions E1 to E10 of table 1 were subjected to study the performance properties of the coating compositions as illustrated in Experiment 2.
Experiment 2: Performance studies of the coating composition prepared in accordance with the present disclosure
A substrate such as wooden panel was coated with the coating compositions E1 to E10 as prepared in Experiment 1 followed by curing for 7 days at room temperature. The examples of Table 2, were subjected for performance studies in order to study the various parameters including coat finish, gloss at 20º, gloss at 60º, tack free time and pencil hardness.
The results are tabulated in the following Table 3.
Table 3: Physicochemical properties of the coating composition in accordance with the present disclosure
Performance E1 E2 E3 E4 E5 E6 E7 E8 E9 E10

Finish Wrinkle Sporadic
wrinkles Smooth Smooth Smooth Smooth Wrinkles on edges
and patterning Wrinkles on edges and patterning Wrinkles on edges and patterning Smooth

Gloss at 20º --- --- 89 85 86 87 88 89 85 88
Gloss at 60º --- --- 93 89 90 90 91 92 90 91
Tack Free Time 5 10 30 30 40 35 15 30 15 23

Pencil Hardness --- --- 5H 4H 2H 3H 2H 2H fail 5H 4H
From Table 3, it is observed that the coating composition E3 shows improved performance properties such as smooth finish, better Gloss at 20º and 60º, having sufficient tack free time and provides 5H pencil hardness in coated film on wooden substrate.
The results of the coating compositions E1 to E10, modified by adjusting the amounts of urethane polyacrylate, kinetic control additive, pot life enhancer, and catalyst, clearly demonstrate that precise formulation adjustments significantly vary the performance characteristics of the coatings. By varying the amounts of these additives, it is observed that the coating properties such as finishing, glossiness, tack-free time, and pencil hardness could be varied. The controlled inclusion of specific additives, such as the kinetic control additive and pot life enhancer, led to notable improvements in certain properties.
TECHNICAL ADVANCES AND ECONOMIC SIGNIFICANCE
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of
? a coating composition that:
• has good visual gloss;
• is isocyanate free and amino resin free;
• provides 5H pencil hardness to coating;
• provides longer pot life;
• provides fast drying; and
• is environment friendly.
and
? a process for the preparation of a coating composition that:
• is simple and environment friendly.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values given for various physical parameters, dimensions, and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions, and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. ,CLAIMS:WE CLAIM:
1. A two-component coating composition comprising:
i. a first component comprising
• a reaction product of a malonated polyester and at least one polyacrylate;
• at least one additive selected from the group consisting of a kinetic control additive, a pot life enhancer and a flow and levelling additive; and
• at least one fluid medium; and
ii. a second component comprising a catalyst.
2. The coating composition as claimed in claim 1, wherein said first component and said second component are mixed before application.
3. The coating composition as claimed in claim 1, wherein said malonated polyester is a reaction product of at least one polyester, a predetermined amount of at least one active methylene compound and an anti-oxidant.
4. The coating composition as claimed in claim 3, wherein said polyester is a reaction product of polyols and a polyacid.
5. The coating composition as claimed in claim 4, wherein
• said polyols are selected from the group consisting of a difunctional polyol, a trifunctional polyol and a tetrafunctional polyol; and
• said polyacid is selected from the group consisting of isophthalic acid, adipic acid, terephthalic acid and polyacid derivative; and wherein said polyacid derivative is polyacid anhydride selected from hexahydrophthalic anhydride and phthalic anhydride.
6. The coating composition as claimed in claim 5, wherein
• said difunctional polyol is selected from the group consisting of neo-pentyl glycol, ethylene glycol, hexane diol, diethylene glycol, butyl ethyl propanediol, cyclohexane dimethanol and methyl propanediol;
• said trifunctional polyol is selected from glycerine and trimethylolpropane; and
• said tetrafunctional polyol is selected from pentaerythritol and di-trimethylolpropane.
7. The coating composition as claimed in claim 3, wherein
• said active methylene compound is selected from the group consisting of diethyl malonate, dimethyl malonate, tert-butyl acetoacetate and ethyl acetoacetate; and
• said anti-oxidant is selected from the group consisting of triphenyl phosphite, hypophosphorous acid and pentaerythritol tetrakis(3-(3,5-Di-tertiary-butyl-4-hydroxyphenyl) propionate).
8. The coating composition as claimed in claim 1, wherein said polyacrylate is selected from the group consisting of urethane polyacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate and di-trimethylol propane tetraacrylate.
9. The coating composition as claimed in claim 1, wherein a ratio of -CH equivalent weight of the malonated polyester to the equivalent weight of the polyacrylate is in the range of 1:0.8 to 1:1.1.
10. The coating composition as claimed in claim 1, wherein said catalyst is selected from tetrabutylammonium methyl carbonate and tetrabutylammonium ethyl carbonate.
11. The coating composition as claimed in claim 1, wherein
• said kinetic control additive is selected from the group consisting of succinimide, ethylacetoacetate, 1H-benzotriazole and 1,2,4-triazole;
• said pot life enhancer is selected from the group consisting of isopropanol, propylene glycol, carbitol, 2-ethyl hexanol, isobutanol and butyl cellosolve; and
• said flow and levelling additive is selected from silicon based flow and levelling additive, acryl-silicone hybrid and polyester; wherein said silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.
12. The coating composition as claimed in claim 1, said fluid medium is selected from the group consisting of methyl ethyl ketone, butyl acetate, acetone, isopropyl alcohol, xylene and solvent naphtha.
13. The coating composition as claimed in claim 3, wherein
• said predetermined amount of said active methylene compound is in the range of 15 mass% to 45 mass%; and
• said predetermined amount of said anti-oxidant is in the range of 0.05 mass% to 0.5 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said malonated polyester.
14. The coating composition as claimed in claim 4, wherein
• said predetermined amount of said polyols is in the range of 0.3 mass% to 45 mass%; and
• said predetermined amount of said polyacid is in the range of 20 mass% to 50 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said malonated polyester.
15. The coating composition as claimed in claim 1, wherein
• said predetermined amount of said malonated polyester is in the range of 35 mass% to 45 mass%;
• said predetermined amount of said polyacrylate is in the range of 0.5 mass% to 20 mass%;
• said predetermined amount of said kinetic control additive is in the range of 3 mass% to 15 mass%;
• said predetermined amount of said pot life enhancer is in the range of 3 mass% to 15 mass%;
• said predetermined amount of said fluid medium is in the range of 5 mass% to 15 mass%;
• said predetermined amount of said flow and leveling additive is in the range of 0.2 mass% to 1 mass%; and
• said predetermined amount of said catalyst is in the range of 5 mass% to 15 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said coating composition.
16. A process for the preparation of a two-component coating composition, said process comprising the following steps
a. mixing predetermined amounts of polyols, a polyacid and an anti-oxidant followed by heating to a first predetermined temperature for a first predetermined time period in an inert atmosphere to obtain a polyester;
b. cooling said polyester to a second predetermined temperature followed by adding a predetermined amount of active methylene compound and heating to a third predetermined temperature for a second predetermined time period to obtain a reaction mixture comprising malonated polyester;
c. cooling said reaction mixture comprising malonated polyester to said second predetermined temperature followed by adding a first fluid medium and further cooling to a temperature in the range of 25 oC to 35 oC to obtain a malonated polyester;
d. mixing predetermined amounts of said malonated polyester, at least one polyacrylate, a first additive and said first fluid medium under stirring at a first predetermined speed for a third predetermined time period followed by adding predetermined amounts of a second fluid medium and a second additive under stirring at a second predetermined speed for a fourth predetermined time period to obtain a homogenized mixture of a first component; and
e. adding a predetermined amount of a second component in said homogenized mixture at a fourth predetermined temperature for a fifth predetermined time period to obtain said coating composition.
17. The process as claimed in claim 16, wherein said second component is added to said first component prior to use.
18. The process as claimed in claim 16, wherein
• said polyols are selected from the group consisting of a difunctional polyol, a trifunctional polyol and a tetrafunctional polyol;
• said polyacid is selected from the group consisting of isophthalic acid, adipic acid, terephthalic acid and polyacid derivative; wherein said polyacid derivative is polyacid anhydride selected from hexahydrophthalic anhydride and phthalic anhydride;
• said anti-oxidant is selected from the group consisting of triphenyl phosphite, hypophosphorous acid and pentaerythritol tetrakis(3-(3,5-Di-tertiary-butyl-4-hydroxyphenyl)propionate);
• said active methylene compound is selected from the group consisting of diethyl malonate, dimethyl malonate, tert-butyl acetoacetate and ethyl acetoacetate;
• said polyacrylate is selected from the group consisting of urethane polyacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate and di-trimethylol propane tetraacrylate;
• said first additive is selected from kinetic control additive and pot life enhancer;
• said second additive is a flow and levelling additive selected from a silicon based flow and levelling additive, acryl-silicone hybrid and polyester;
• said first fluid medium and said second fluid medium are independently selected from the group consisting of methyl ethyl ketone, butyl acetate, acetone, isopropyl alcohol, xylene and solvent naphtha; and
• said second component is a catalyst selected from tetrabutylammonium methyl carbonate and tetrabutylammonium ethyl carbonate.

19. The process as claimed in claim 18, wherein
• said difunctional polyol is selected from the group consisting of neo-pentyl glycol, ethylene glycol, hexane diol, diethylene glycol, butyl ethyl propanediol, cyclohexane dimethanol, and methyl propanediol;
• said trifunctional polyol is selected from glycerine and trimethylolpropane;
• said tetrafunctional polyol is selected from pentaerythritol and di-trimethylolpropane;
• said kinetic control additive is selected from the group consisting of succinimide, ethylacetoacetate, 1H-benzotriazole and 1,2,4-triazole;
• said pot life enhancer is selected from the group consisting of isopropanol, propylene glycol, carbitol, 2-ethyl hexanol, isobutanol and butyl cellosolve; and
• said silicon based flow and levelling additive is polyether-modified polydimethylsiloxane.

20. The process as claimed in claim 16, wherein a ratio of -CH equivalent weight of the malonated polyester to the equivalent weight of the polyacrylate is in the range of 1:0.8 to 1:1.1.
21. The process as claimed in claim 16, wherein
• said predetermined amount of said polyols is in the range of 0.3 mass% to 45 mass%;
• said predetermined amount of said polyacid is in the range of 20 mass% to 50 mass%;
• said predetermined amount of said active methylene compound is in the range of 15 mass% to 45 mass%; and
• said predetermined amount of said anti-oxidant is in the range of 0.05 mass% to 0.5 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said malonated polyester.

22. The process as claimed in claim 16, wherein
• said predetermined amount of said malonated polyester is in the range of 35 mass% to 45 mass%;
• said predetermined amount of said polyacrylate is in the range of 0.5 mass% to 20 mass%;
• said predetermined amount of said first additive is in the range of 3 mass% to 15 mass%;
• said predetermined amounts of said first fluid medium and said second fluid medium are independently in the range of 5 mass% to 15 mass%;
• said predetermined amount of said second additive is in the range of 0.2 mass% to 1 mass%; and
• said predetermined amount of said second component is in the range of 5 mass% to 15 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said coating composition.
23. The process as claimed in claim 16, wherein
• said first predetermined temperature is in the range of 200 ºC to 250 ºC;
• said second predetermined temperature is in the range of 100 ºC to 140 ºC;
• said third predetermined temperature is in the range of 150 ºC to 200 ºC; and
• said fourth predetermined temperature is in the range of 25 ºC to 30 ºC.
24. The process as claimed in claim 16, wherein
• said first predetermined time period is in the range of 10 hours to 14 hours;
• said second predetermined time period is in the range of 3 hours to 6 hours;
• said third predetermined time period is in the range of 10 minutes to 20 minutes;
• said fourth predetermined time period is in the range of 10 minutes to 30 minutes; and
• said fifth predetermined time period is in the range of 2 minutes to 15 minutes.
25. The process as claimed in claim 16, wherein
• said first predetermined stirring speed is in the range of 500 rpm to 700 rpm; and
• said second predetermined stirring speed is in the range of 500 rpm to 700 rpm.
26. The process as claimed in claim 16, wherein said inert atmosphere is obtained by using nitrogen gas.

Dated this 26th Day of March 2025

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
OF R. K. DEWAN & CO.
AUTHORIZED AGENT OF APPLICANT

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI