DESC:FIELD
The present disclosure relates to field of screen-printing technology.
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.
Screen-printing: The term “Screen-printing” refers to a printing technique wherein a stenciled design is transferred onto a substrate by using a polyester mesh as a screen and ink.
Screen-printing ink: The term “screen-printing ink” refers to an ink composition that is specifically developed for printing on a substrate by using the screen-printing technique.
Slip additive: The term “Slip additive” refers to the compound which when added to the inks, coatings or other formulations enhances the smoothness during application on a substrate, improves the ease of processing and improves the final surface finish of the substrate.
Hi-S-Cal: The term “Hi-S-Cal” refers to a type of highly smooth calendered paper, often used as a substrate in labeling, printing, or decal applications.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
There is a growing demand for printing inks in industrial applications such as automotive, packaging, construction, agriculture, electronics, healthcare, and machinery. Plastics are widely used in these sectors for their versatility, durability, and cost-effectiveness. Common plastics include acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), acrylic coated polyester, cellulose acetate butyrate plastic (CAB), Hi-S-Cal, cellulose acetate, polyethylene (PE), and polycarbonate (PC). Plastics used in all these industrial applications are commonly printed with solvent-based inks. UV-curable inks are also there in the market. However, N-vinyl caprolactam and certain monomers used in UV inks to enhance the adhesion on substrates are hazardous to human health and do not comply with European standards.
Existing solvent-based inks are formulated with solvents that dissolve and disperse ink components, ensuring good adhesion to substrates such as ABS, PVC, Acrylic, coated polyester, CAB, Hi-S-Cal, cellulose acetate, polyethylene, polycarbonate, and the like. These inks majorly used polyvinyl based resins which provides excellent printability performance. They dry quickly due to volatile solvents and provide resistance to chemicals, excellent durability, resistance to UV light, and abrasion resistance.
However, existing polyvinyl based inks pose significant environmental concerns, primarily due to their polyvinyl chloride (PVC) content, which is non-biodegradable. Further, the life cycle of PVC involves release of chemicals, resulting in highly toxic and carcinogenic by-products such as dioxins and polychlorinated biphenyls (PCBs). Improper disposal via incineration releases these toxic chemicals into the environment. PVC also contributes to greenhouse gas emissions, which further exacerbates the environmental burden by depleting the ozone layer. As PVC is not easily biodegradable, it poses long-term environmental risks, making its disposal a significant concern.
Further, the solvents required for such vinyl-based inks to achieve the desired printability often contain volatile organic compounds (VOCs), which contribute to air pollution and negatively impact the environment. Further, the solvent-based inks can emit strong odors due to the volatile solvents present. This odor can be unpleasant. VOCs can also contribute to the formation of smog and have potential health risks and may require additional measures to mitigate the impact on the working environment. Proper safety measures, such as adequate ventilation and personal protective equipment, are necessary when working with these inks.
Water-based screen-printing inks are also not suitable for printing on plastic materials for the lack of chemical resistance properties.
Therefore, there is felt a need to provide a PVC-free composition that mitigates the drawbacks mentioned hereinabove and at least provides a useful alternative.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
An object of the present disclosure is to ameliorate one or more problems of the background or to at least provide a useful alternative.
Yet another object of the present disclosure is to provide a PVC-free composition.
Still another object of the present disclosure is to provide a PVC-free ink composition.
Yet another object of the present disclosure is to provide a PVC-free screen printing ink composition having a PVC-free resin system that is compatible with common organic solvents.
Yet another object of the present disclosure is to provide a PVC-free ink composition that is suitable for various plastic substrates such as acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), acrylic, acrylic, coated polyester, CAB, Hi-S-Cal, cellulose acetate, polyethylene (PE), polycarbonate (PC) and the like.
Still another object of the present disclosure is to provide a PVC-free ink composition that is suitable for outdoors.
Yet another object of the present disclosure is to provide a simple and economical process for the preparation of the PVC-free screen printing ink composition
Still another object of the present disclosure is to provide a PVC-free overprint coating composition that is suitable for outdoors.
Yet another object of the present disclosure is to provide a simple and economical process for the preparation of the PVC-free overprint coating composition.
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
In an aspect, the present disclosure relates to a PVC-free composition comprising:
i. at least one resin in an amount in the range of 25 mass% to 50 mass%;
ii. at least one solvent in an amount in the range of 40 mass% to 70 mass%;
iii. at least one additive in an amount in the range of 0.2 mass% to 2 mass%;
iv. a stabilizer in an amount in the range of 1 mass% to 5 mass%;
v. at least one pigment in an amount in the range of 0 mass% to 30 mass%; and
vi. at least one dispersant in an amount in the range of 0 mass% to 2 mass%; and
wherein the mass% of each component is with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the resin is at least one selected from the group consisting of an acrylic based resin, a polyurethane based resin and an ester-based resin; wherein the acrylic based resin is selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate and butyl acrylate; the polyurethane based resin is selected from aliphatic polyurethanes; and the ester-based resin is selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate.
In an embodiment of the present disclosure, the solvent is at least one selected from the group consisting of butyl cellosolve acetate, isophorone, C9 petroleum naphtha, cyclohexanone, diacetone alcohol, butyl glycol ether, isopropyl oxitol, diethylene glycol, 2-ethylhexyl acetate, isopropyl acetoacetate, ethoxypropyl acetate, derivatives of dibasic esters, propylene glycol monomethyl ether acetate, diacetone alcohol, n-methoxy-2-propanol, diethylene glycol monoethyl ether, diethylene glycol monoethyl ester and glycol ether based solvents.
In an embodiment of the present disclosure, the additive is a slip additive and is at least one selected from the group consisting of multifunctional acrylic additives, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additives, hydroxy-functional polydimethylsiloxane and low odor epoxy ester.
In an embodiment of the present disclosure, the stabilizer is at least one selected from the group consisting of 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, hydroxyphenyl-triazine derivatives, 6-di-tert-pentylphenol, and hydroxyphenyl triazine.
In an embodiment of the present disclosure, the pigment is at least one selected from the group consisting of inorganic pigments, metal based pigments and organic pigments; wherein the inorganic pigments are selected from titanium dioxide and carbon black; the metal based pigments are selected from pigment gold bronze and aluminum pigment; and the organic pigments are selected from the group consisting of dye lake pigments, azo-based pigments, benzimidazolone based pigments, phthalocyanine-based pigments, quinacridone-based pigments, anthraquinone-based pigments, triphenyl methane based pigment, dioxazine-based pigments, indigo-based pigments, thioindigo-based pigments, perylene–based pigments, perinone-based pigments, diketopyrrolopyrrole-based pigments, isoindolinone-based pigments, nitro-based pigments, pyranthrone-based pigments and indanethrone-based pigments.
In an embodiment of the present disclosure, the dispersant is at least one selected from the group consisting of polyether-modified polydimethylsiloxane, alcohol ethoxylates, fluorinated surfactants, benzene sulfonic acid, silicone surfactants, polyacrylate-based surfactants, and modified polyurethane surfactants.
In an embodiment of the present disclosure, the PVC-free composition is a PVC-free screen printing ink composition or a PVC-free overprint coating composition.
In an embodiment of the present disclosure, the PVC-free screen-printing ink composition comprises:
a) at least one resin in an amount in the range of 25 mass% to 40 mass%;
b) at least one solvent in an amount in the range of 40 mass% to 70 mass%;
c) at least one pigment in an amount in the range of 5 mass% to 30 mass%;
d) a stabilizer in an amount in the range of 1 mass% to 5 mass%;
e) a dispersant in an amount in the range of 0.1 mass% to 2 mass%; and
f) at least one additive in an amount in the range of 0.2 mass% to 2 mass%,
wherein the mass% of each component is with respect to the total mass of the PVC-free screen-printing ink composition.
In an embodiment of the present disclosure, the PVC-free screen printing ink composition is characterized by having at least one of the following:
• viscosity in the range of 10 Poise to 40 Poise measured as per ASTM D1200-23;
• gloss percentage in the range of 70% to 92% measured as per ISO2813:20145(E);
• density of print in the range of 1 to 2.2 measured as per ASTM 7305-08a(2020); and
• specific gravity in the range of 1 to 1.5.
In an embodiment of the present disclosure, the PVC-free overprint coating composition comprises:
a) at least one resin in an amount in the range of 30 mass% to 50 mass%;
b) at least one solvent in an amount in the range of 40 mass% to 70 mass%;
c) at least one additive in an amount in the range of 0.2 mass% to 2 mass%; and
d) a stabilizer in an amount in the range of 1 mass% to 5 mass%,
wherein the mass% of each component is with respect to the total mass of the overprint coating composition.
In an embodiment of the present disclosure, the PVC-free overprint coating composition is characterized by having at least one of the following:
• viscosity in the range of 5 Poise to 40 Poise measured as per ASTM D1200-23;
• gloss percentage in the range of 80% to 95% measured as per ISO2813:20145(E); and
• specific gravity in the range of 1 to 1.5.
In another aspect, the present disclosure relates to a process for the preparation of PVC-free composition. The process comprises the following steps:
a) mixing predetermined amounts of at least one resin and at least one solvent under stirring at a first predetermined temperature and at a first predetermined stirring speed for a first predetermined time period to obtain a mixture;
b) optionally adding predetermined amounts of at least one pigment and a dispersant to the mixture under stirring at a second predetermined temperature and at a second predetermined stirring speed for a second predetermined time period followed by milling to obtain a homogeneous mixture; and
c) adding a predetermined amount of at least one additive and a stabilizer in the mixture in step a) OR the homogeneous mixture in step b) under stirring at a third predetermined temperature and at a third predetermined stirring speed for a third predetermined time period to obtain the PVC-free composition.
In an embodiment of the present disclosure, the first predetermined temperature is in the range of 45 °C to 70 °C.
In an embodiment of the present disclosure, the second predetermined temperature and the third predetermined temperature are independently in the range of 20°C to 40°C.
In an embodiment of the present disclosure, the first predetermined stirring speed is in the range of 1200 rpm to 1500 rpm.
In an embodiment of the present disclosure, the second predetermined stirring speed and the third predetermined stirring speed are independently in the range of 500 rpm to 1200 rpm.
In an embodiment of the present disclosure, the first predetermined time period is in the range of 1 hour to 5 hours.
In an embodiment of the present disclosure, the second predetermined time period is in the range of 1 hour to 3 hours.
In an embodiment of the present disclosure, the third predetermined time period is in the range of 15 minutes to 60 minutes.
In an embodiment of the present disclosure, the homogeneous mixture has an average particle size of less than 5 µm.
DETAILED DESCRIPTION
The present disclosure relates to screen-printing technology. Particularly, the present disclosure relates to a PVC-free composition for screen-printing.
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.
Existing solvent-based inks majorly used polyvinyl based resins which provides excellent printability performance. They dry quickly due to volatile solvents and provide resistance to chemicals, excellent durability, resistance to UV light, and abrasion resistance. Existing polyvinyl-based based inks pose significant environmental concerns, primarily due to their polyvinyl chloride (PVC) content, which is non-biodegradable. Further, the life cycle of PVC involves release of toxic chlorine-based chemicals, resulting in highly toxic and carcinogenic by-products such as dioxins and polychlorinated biphenyls (PCBs). As PVC is not easily biodegradable, it poses long-term environmental risks, making its disposal a significant concern.
The present disclosure provides a PVC-free composition and a process for its preparation. The PVC-free composition of the present disclosure are environment friendly and safe. The PVC-free composition of the present disclosure imparts properties such as adhesion, chemical resistance, light fastness and excellent drying time when applied to various plastic substrates such as ABS, PVC, acrylic, coated polyester, CAB, Hi-S-Cal, cellulose acetate, polyethylene, polycarbonate, and the like. The PVC-free composition of the present disclosure has low viscosity which enables smooth flow through print heads or screens (especially in inkjet or screen printing), minimizes clogging, ensuring consistent ink deposition, and enables fine detail printing and better resolution.
In an aspect, the present disclosure relates to a PVC-free composition comprising:
i. at least one resin in an amount in the range of 25 mass% to 50 mass%;
ii. at least one solvent in an amount in the range of 40 mass% to 70 mass%;
iii. at least one additive in an amount in the range of 0.2 mass% to 2 mass%;
iv. a stabilizer in an amount in the range of 1 mass% to 5 mass%;
v. at least one pigment in an amount in the range of 0 mass% to 30 mass%; and
vi. at least one dispersant in an amount in the range of 0 mass% to 2 mass%; and
wherein the mass% of each component is with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the resin is at least one selected from the group consisting of an acrylic based resin, a polyurethane based resin and an ester-based resin; wherein the acrylic based resin is selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate and butyl acrylate; the polyurethane based resin is selected from aliphatic polyurethanes; and the ester-based resin is selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. In an exemplary embodiment, the resin is 2-ethylbutyl acrylate. In another exemplary embodiment, the resin is butyl acrylate.
In an embodiment of the present disclosure, the solvent is at least one selected from the group consisting of butyl cellosolve acetate, isophorone, C9 petroleum naphtha, cyclohexanone, diacetone alcohol, butyl glycol ether, isopropyl oxitol, diethylene glycol, 2-ethylhexyl acetate, isopropyl acetoacetate, ethoxypropyl acetate, derivatives of dibasic esters, propylene glycol monomethyl ether acetate, diacetone alcohol, n-methoxy-2-propanol, diethylene glycol monoethyl ether, diethylene glycol monoethyl ester and glycol ether based solvents.
In an exemplary embodiment, the solvent is a combination of 2-ethylhexyl acetate, isopropyl acetoacetate, butyl cellosolve acetate, n-methoxy-2-propanol and diethylene glycol monoethyl ether.
In an embodiment of the present disclosure, the additive is a slip additive and is at least one selected from the group consisting of multifunctional acrylic additives, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additives, hydroxy-functional polydimethylsiloxane and low odor epoxy ester. In an exemplary embodiment, the slip additive is methylphenyl siloxane.
In an embodiment of the present disclosure, the stabilizer is at least one selected from the group consisting of 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol(UV-328), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (UV-292), hydroxyphenyl-triazine derivatives (UV-400), 6-di-tert-pentylphenol, and hydroxyphenyl triazine. In an exemplary embodiment, the stabilizer is 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328). In another exemplary embodiment, the stabilizer is bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (UV-292). In yet another exemplary embodiment, the stabilizer is hydroxyphenyl-triazine derivatives (UV-400).
In an embodiment of the present disclosure, the pigment is at least one selected from the group consisting of inorganic pigments, metal based pigments and organic pigments; wherein the inorganic pigments are selected from titanium dioxide and carbon black; the metal based pigments are selected from the group consisting of pigment gold bronze and aluminum pigment; and the organic pigments are selected from dye lake pigments, azo-based pigments, benzimidazolone based pigments, phthalocyanine-based pigments, quinacridone-based pigments, anthraquinone-based pigments, triphenyl methane based pigment, dioxazine-based pigments, indigo-based pigments, thioindigo-based pigments, perylene–based pigments, perinone-based pigments, diketopyrrolopyrrole-based pigments, isoindolinone-based pigments, nitro-based pigments, pyranthrone-based pigments and indanethrone-based pigments.
In an exemplary embodiment, the pigment is phthalocyanine pigment Green (phthalocyanine-based pigment). In another exemplary embodiment, the pigment is carbon black (inorganic pigment). In still another exemplary embodiment, the pigment is carbon black-45 (inorganic pigment). In yet another exemplary embodiment, the pigment is titanium dioxide (inorganic pigment). In still another exemplary embodiment, the pigment is yellow-83 (azo-based pigment). In yet another exemplary embodiment, the pigment is pigment orange-34 (azo-based pigment). In still another exemplary embodiment, the pigment is a mixture of pigment pink-17 (triphenyl methane based pigment) and titanium dioxide (inorganic pigment). In yet another exemplary embodiment, the pigment is pigment violet-1 (triphenyl methane based pigment). In still another exemplary embodiment, the pigment is pigment red-57 (azo-based pigment). In yet another exemplary embodiment, the pigment is beta phthalocyanine blue (phthalocyanine-based pigment). In still another exemplary embodiment, the pigment is pigment gold bronze (metal based pigment). In yet another exemplary embodiment, the pigment is aluminium pigment (metal based pigment).
In an embodiment of the present disclosure, the dispersant is at least one selected from the group consisting of polyether-modified polydimethylsiloxane, alcohol ethoxylates, fluorinated surfactants, benzene sulfonic acid, silicone surfactants, polyacrylate-based surfactants, and modified polyurethane surfactants. In an exemplary embodiment, the dispersant is benzene sulfonic acid.
In an embodiment of the present disclosure, the PVC-free composition is a PVC-free screen printing ink composition or a PVC-free overprint coating composition.
In an embodiment of the present disclosure, the PVC-free screen-printing ink composition comprises:
a) at least one resin in an amount in the range of 25 mass% to 40 mass%;
b) at least one solvent in an amount in the range of 40 mass% to 70 mass%;
c) at least one pigment in an amount in the range of 5 mass% to 30 mass%;
d) a stabilizer in an amount in the range of 1 mass% to 5 mass%;
e) a dispersant in an amount in the range of 0.1 mass% to 2 mass%; and
f) at least one additive in an amount in the range of 0.2 mass% to 2 mass%,
wherein the mass% of each component is with respect to the total mass of the PVC-free screen-printing ink composition.
In an embodiment of the present disclosure, the PVC-free screen printing ink composition is characterized by having at least one of the following:
• viscosity in the range of 10 Poise to 40 Poise measured as per ASTM D1200-23;
• gloss percentage in the range of 70% to 92% measured as per ISO2813:20145(E);
• density of print in the range of 1 to 2.2 measured as per ASTM 7305-08a(2020); and
• specific gravity in the range of 1 to 1.5.
In an exemplary embodiment, the PVC-free screen-printing ink composition is characterized by having a viscosity of 18 Poise as per ASTM D1200-23, gloss percentage of 85%, and density of print 1.35, and specific gravity of 1.32.
In an exemplary embodiment, the PVC-free ink screen-printing ink composition comprises:
i. 2-ethylbutyl acrylate in an amount of 33 mass% with respect to the total mass of the PVC-free screen-printing ink composition;
ii. isopropyl acetoacetate in an amount of 20 mass% with respect to the total mass of the PVC-free screen-printing ink composition;
iii. butyl cellosolve acetate in an amount of 18 mass% with respect to the total mass of the PVC-free screen-printing ink composition;
iv. 2-ethylhexyl acetate in an amount of 15 mass% with respect to the total mass of the PVC-free screen-printing ink composition;
v. Carbon black in an amount of 11 mass% with respect to the total mass of the PVC-free screen-printing ink composition;
vi. 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328) in an amount of 1.3 mass% % with respect to the total mass of the PVC-free screen-printing ink composition;
vii. benzene sulfonic acid in an amount of 0.8 mass% with respect to the total mass of the PVC-free screen-printing ink composition; and
viii. methylphenyl siloxane at least one additive in of 0.9 mass% with respect to the total mass of the PVC-free screen-printing ink composition.
In an embodiment of the present disclosure, the PVC-free composition is a PVC-free overprint coating composition comprising:
a) at least one resin in an amount in the range of 30 mass% to 50 mass%;
b) at least one solvent in an amount in the range of 40 mass% to 70 mass%;
c) at least one additive in an amount in the range of 0.2 mass% to 2 mass%; and
d) a stabilizer in an amount in the range of 1 mass% to 5 mass%,
wherein the mass% of each component is with respect to the total mass of the overprint coating composition.
In an embodiment of the present disclosure, the PVC-free overprint composition is characterized by having at least one of the following:
• viscosity in the range of 5 Poise to 40 Poise measured as per ASTM D1200-23;
• gloss percentage in the range of 80% to 95% measured as per ISO2813:20145(E); and
• specific gravity in the range of 1 to 1.5.
In an exemplary embodiment, the overprint coating composition has a viscosity of 18 Poise, a gloss percentage of 90%, and a specific gravity of 1.3.
In an exemplary embodiment, the overprint coating composition comprises:
a. 2-ethylbutyl acrylate in an amount of 33 mass% with respect to the total mass of the overprint coating composition;
b. isopropyl acetoacetate in an amount of 31.8 mass% with respect to the total mass of the overprint coating composition;
c. butyl cellosolve acetate in an amount of 18 mass% with respect to the total mass of the overprint coating composition;
d. 2-ethylhexyl acetate in an amount of 15 mass% with respect to the total mass of the overprint coating composition;
e. methylphenyl siloxane at least one additive in of 0.9 mass% with respect to the total mass of the overprint coating composition; and
f. stabilizer 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328) in an amount of 1.3 mass% with respect to the total mass of the overprint coating composition.
In another aspect, the present disclosure relates to a process for the preparation of PVC-free composition. The process comprises the following steps:
a) mixing predetermined amounts of at least one resin and at least one solvent under stirring at a first predetermined temperature and at a first predetermined stirring speed for a first predetermined time period to obtain a mixture;
b) optionally adding predetermined amounts of at least one pigment and a dispersant to the mixture under stirring at a second predetermined temperature and at a second predetermined stirring speed for a second predetermined time period followed by milling to obtain a homogeneous mixture; and
c) adding a predetermined amount of at least one additive and a stabilizer in the mixture in step a) OR the homogeneous mixture in step b) under stirring at a third predetermined temperature and at a third predetermined stirring speed for a third predetermined time period to obtain the PVC-free composition.
The process is described in detail.
In a first step, predetermined amounts of at least one resin and at least one solvent are mixed under stirring at a first predetermined temperature and at a first predetermined stirring speed for a first predetermined time period to obtain a mixture.
In an embodiment of the present disclosure, the resin is at least one selected from the group consisting of an acrylic based resin, a polyurethane based resin and an ester-based resin; wherein the acrylic based resin is selected from methyl methacrylate, isobutyl methyl acrylate, butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate and butyl acrylate; the polyurethane based resin is selected from aliphatic polyurethanes; and the ester-based resin is selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. In an exemplary embodiment, the resin is 2-ethylbutyl acrylate. In another exemplary embodiment, the resin is butyl acrylate.
In an embodiment of the present disclosure, the resin is present in an amount in the range of 25 mass% to 50 mass% with respect to the total mass of the PVC-free coating composition. In an exemplary embodiment, the resin is present in an amount of 33 mass% with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the solvent is at least one selected from the group consisting of butyl cellosolve acetate, isophorone, C9 petroleum naphtha, cyclohexanone, diacetone alcohol, butyl glycol ether, isopropyl oxitol, diethylene glycol, 2-ethylhexyl acetate, isopropyl acetoacetate, ethoxypropyl acetate, derivatives of dibasic esters, propylene glycol monomethyl ether acetate, diacetone alcohol, n-methoxy-2-propanol, diethylene glycol monoethyl ether, diethylene glycol monoethyl ester and glycol ether based solvents.
In an exemplary embodiment, the solvent is a mixture of isopropyl acetoacetate, 2-ethylhexyl acetate, butyl cellosolve acetate, n-methoxy-2-propanol, and diethylene glycol monoethyl ether.
In an embodiment of the present disclosure, the solvent is present in an amount in the range of 40 mass% to 70 mass% with respect to the total mass of the PVC-free composition. In an exemplary embodiment, the solvent is present in an amount of 53 mass% with respect to the total mass of the PVC-free composition. In another exemplary embodiment, the solvent is present in an amount of 64.8 mass% with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the first predetermined temperature is in the range of 45 °C to 70 °C. In an exemplary embodiment, the first predetermined temperature is 60 °C.
In an embodiment of the present disclosure, the first predetermined stirring speed is in the range of 1200 rpm to 1500 rpm. In an exemplary embodiment, the first predetermined stirring speed is 1300 rpm.
In an embodiment of the present disclosure, the first predetermined time period is in the range of 1 hour to 5 hours. In an exemplary embodiment, the first predetermined time period is 4 hours.
In a second step, optionally predetermined amounts of at least one pigment and a dispersant are added to the mixture under stirring at a second predetermined temperature and at a second predetermined stirring speed for a second predetermined time period followed by milling to obtain a homogeneous mixture.
In an embodiment of the present disclosure, the pigment is at least one selected from the group consisting of inorganic pigments, metal based pigments and organic pigments; wherein the inorganic pigments are selected from titanium dioxide and carbon black; the metal based pigments are selected from pigment gold bronze and aluminum pigment; and the organic pigments are selected from dye lake pigments, azo-based pigments, benzimidazolone based pigments, phthalocyanine-based pigments, quinacridone-based pigments, anthraquinone-based pigments, triphenyl methane based pigment, dioxazine-based pigments, indigo-based pigments, thioindigo-based pigments, perylene–based pigments, perinone-based pigments, diketopyrrolopyrrole-based pigments, isoindolinone-based pigments, nitro-based pigments, pyranthrone-based pigments and indanethrone-based pigments.
In an exemplary embodiment, the pigment is phthalocyanine pigment Green (phthalocyanine-based pigment). In an exemplary embodiment, the pigment is carbon black (inorganic pigment). In another exemplary embodiment, the pigment is carbon black-45 (inorganic pigment). In yet another exemplary embodiment, the pigment is titanium dioxide (inorganic pigment). In still another exemplary embodiment, the pigment is yellow-83 (azo-based pigment). In yet another exemplary embodiment, the pigment is pigment orange-34 (azo-based pigment). In still another exemplary embodiment, the pigment is a mixture of pigment pink-17 (triphenyl methane based pigment) and titanium dioxide (inorganic pigment). In yet another exemplary embodiment, the pigment is pigment violet-1 (triphenyl methane based pigment). In yet another exemplary embodiment, the pigment is pigment red-57 (azo-based pigment). In still another exemplary embodiment, the pigment is beta phthalocyanine blue (phthalocyanine-based pigment). In yet another exemplary embodiment, the pigment is pigment gold bronze (metal based pigment). In still another exemplary embodiment, the pigment is aluminium pigment (metal based pigment).
In an embodiment of the present disclosure, the predetermined amount of the pigment is in the range of 0 mass% to 30 mass% with respect to the total mass of the PVC-free composition. In an exemplary embodiment, the predetermined amount of the pigment is 11 mass% with respect to the total mass of the PVC-free composition. In another exemplary embodiment, the predetermined amount of the pigment is 0 mass% with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the dispersant is at least one selected from the group consisting of polyether-modified polydimethylsiloxane, alcohol ethoxylates, fluorinated surfactants, benzene sulfonic acid, silicone surfactants, polyacrylate-based surfactants, and modified polyurethane surfactants. In an exemplary embodiment, the dispersant is benzene sulfonic acid.
In an embodiment of the present disclosure, the predetermined amount of the dispersant is in the range of 0 mass% to 2 mass% with respect to the total mass of the PVC-free composition. In an exemplary embodiment, the predetermined amount of the dispersant is 0.8 mass% with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the second predetermined temperature is in the range of 20 °C to 40 °C. In an exemplary embodiment, the second predetermined temperature is 25 °C.
In an embodiment of the present disclosure, the second predetermined stirring speed is in the range of 500 rpm to 1200 rpm. In an exemplary embodiment, the second predetermined stirring speed is 800 rpm. In another exemplary embodiment, the second predetermined stirring speed is 1000 rpm.
In an embodiment of the present disclosure, the second predetermined time period is in the range of 1 hour to 3 hours. In an exemplary embodiment, the second predetermined time period is 2 hours.
In an embodiment of the present disclosure, the homogeneous mixture has an average particle size of less than 5 µm. In an exemplary embodiment, the average particle size of the homogeneous mixture is 4 µm.
In a final step, a predetermined amount of at least one additive is added in the mixture in step a) OR the homogeneous mixture in step b) under stirring at a third predetermined temperature and at a third predetermined stirring speed for a third predetermined time period to obtain the PVC-free composition.
In an embodiment of the present disclosure, the additive is a slip additive and at least one selected from the group consisting of multifunctional acrylic additives, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additives, hydroxy-functional polydimethylsiloxane and low odor epoxy ester. In an exemplary embodiment, the slip additive is methylphenyl siloxane.
In an embodiment of the present disclosure, the predetermined amount of the slip additive is in the range of 0.2 mass% to 2 mass% with respect to the total mass of the PVC-free composition. In an exemplary embodiment, the predetermined amount of the slip additive is 0.9 mass% with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the stabilizer is at least one selected from the group consisting of 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol(UV-328), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (UV-292), hydroxyphenyl-triazine derivatives (UV-400), 6-di-tert-pentylphenol, and hydroxyphenyl triazine. In an exemplary embodiment, the stabilizer is 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328). In another exemplary embodiment, the stabilizer is bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (UV-292). In yet another exemplary embodiment, the stabilizer is hydroxyphenyl-triazine derivatives (UV-400).
In an embodiment of the present disclosure, the predetermined amount of the stabilizer is in the range of 1 mass% to 5 mass% with respect to the total mass of the PVC-free composition. In an exemplary embodiment, the predetermined amount of the stabilizer is 1.3 mass% with respect to the total mass of the PVC-free composition.
In an embodiment of the present disclosure, the third predetermined temperature is in the range of 20 °C to 40 °C. In an exemplary embodiment, the third predetermined temperature is 35 °C.
In an embodiment of the present disclosure, third predetermined stirring speed is in the range of 500 rpm to 1200 rpm. In an exemplary embodiment, the third predetermined stirring speed is 800 rpm.
In an embodiment of the present disclosure, the third predetermined time period is in the range of 15 minutes to 60 minutes. In an exemplary embodiment, the third predetermined time period is 30 minutes.
In still another aspect, the present disclosure relates to an automated system for measuring, dispensing and mixing ink comprising a series of containers to hold various basic shades of an PVC-free screen-printing ink in accordance with the present disclosure, and weighing scale with controlled ink management software, wherein the amount of the basic shades are calculated, weighed, dispensed and mixed in a step-by-step controlled process to obtain the desired shade.
To make a specific color, a formula with the right ingredients in exact proportions are essential, these ingredients may include pigment loading for the desired intensity property, binders, and solvents to provide the technical characteristics, and medium or white ink to get the desired lightness information.
The automated system used for color matching of ink of the present disclosure typically consists of a series of tanks or containers that hold the various basic shades of inks which are used to achieve any desired PANTONE shade. These basic shades are carefully measured and mixed together to create the desired ink formulation, which is then dispensed into containers. The ink utilized in the process of the present disclosure is a specially formulated PVC-free screen-printing ink for screen printing applications, suitable to dispense the color through the dispensing head of the dispenser with desired amount and proportion without clogging the equipment to yield an accurate color matching shade.
The automated system of the present disclosure operates on the principle of the inbuilt formulation. The said system combines the weighing scale with controlled ink management software. The system also scales the selected formula to get the desired batch size, calculates the individual weight of each basic shade, carefully measures and then dispenses the material through a step-by-step controlled weighing process, and then mix it together. Thus, ink dispensing technology refers to the processes and systems used for accurately measuring, dispensing ink, and mixing ink for a specified PANTONE color match.
For the conventional screen-printing processes, ink viscosity is high enough above 40 Poise. High-viscosity inks have a thicker consistency, which makes them more difficult to pump and dispense accurately. Ink may clog or damage the equipment that is designed for liquid inks or paints, which typically have a lower viscosity. So, color dispensing for high-viscosity products through the dispensing is not recommended. The present invention describes use of a specially formulated PVC-free screen-printing ink. The physical nature and characteristics such as low and consistent viscosity of the PVC-free screen -printing ink of the present disclosure are suitable for screen printing applications without clogging the equipment.
PVC-free composition of the present disclosure is used for industrial applications on substrates like ABS, PVC, PE, polycarbonate, cellulose acetate butyrate plastic, Hi-S-Cal, cellulose acetate, and acrylic. The PVC-free composition of the present disclosure is suitable for the outdoor applications.
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: A process for preparation of the PVC-free composition in accordance with the present disclosure.
Example 1: A process for preparation of the PVC-free screen-printing ink composition in accordance with the present disclosure.
33 g of 2-ethylbutyl acrylate (acrylic resin) and 15 g of 2-ethylhexyl acetate (solvent), 20 g of isopropyl acetoacetate (solvent), and 18 g of butyl cellosolve acetate (solvent) were mixed at 60 °C under stirring at 1300 rpm for 4 hours to obtain a mixture.
11 g of carbon black (pigment) and 0.8 g of benzene sulfonic acid (dispersant) were added to the mixture at 25 °C under stirring at 800 rpm for 2 hours followed by milling in a triple roll mill to obtain a homogeneous mixture (average particle size 4 µM).
0.9 g of methylphenyl siloxane (slip additive), 1.3 g of stabilizer UV-328 were added to the homogeneous mixture at 35 °C under stirring at 800 rpm for 30 minutes to obtain the PVC-free screen printing ink composition.
Examples 2 to 18
Examples 2 to 18 were prepared in a similar manner as provided in Example 1, except the following components were used as given in Table 1.
Table 1: Different examples of the PVC free-solvent ink of the present disclosure along with specific pigment used.
Example Pigment Specific gravity Gloss % Density of print
Example 1 Carbon Black 1.32 73% to 83% 1.350-1.335
Example 2 Carbon Black -45 1.32 80% to 92% 1.320-1.310
Example 3 Titanium Dioxide 1.33 63% to 75% 1.300-1.280
Example 4 Titanium Dioxide 1.41 37% to 68% 1.355-1.450
Example 5 Titanium Dioxide 1.435 75% to 85% 1.230-1.240
Example 6 Yellow-83 1.33 78% to 85% 1.230-2.240
Example 7 Yellow-83 1.335 77% to 85% 1.320-1.335
Example 8 Pigment Orange 1.34 76% to 85% 1.310-1.325
Example 9 Pigment Pink-17 + TiO2 1.35 77% to 85% 1.345
Example 10 Pigment Violet-1 1.35 75% to 85% 1.340-1.350
Example 11 Pigment Red-57 1.35 77% to 87% 1.340-1.350
Example 12 Pigment Pink-17 1.34 78% to 88% 1.320-1.330
Example 13 Pigment orange-34 1.35 79% to 86% 1.335-1.340
Example 14 Beta Phthalocyanine Blue 1.36 78% to 88% 1.350-1.360
Example 15 Pigment Green 1.35 77% to 85% 1.350-1.360
Example 16 Gold Bronze 1.46 65% to 76% 1.300-1.320
Example 17 Aluminum Paste 1.45 65% to 75% 1.325-1.335
Example 18 Base
(Control) 1.325 78% to 88% 1.340-1.350
Table 1 shows the specific gravity, gloss and print density of the specially formulated different examples of the PVC-free solvent based inks.
Further, the properties of the so obtained screen-printing ink composition were studied, and the results are provided as given below:
Properties of the PVC-free screen-printing ink composition in accordance with the present disclosure
The PVC-free screen-printing ink composition obtained in the Experiment 1 of the present disclosure, was tested against the PVC solvent based ink. The following tests were performed by using the standard test methods.
PVC based solvent based series refers to conventional PVC based screen printing inks developed by Fujifilm for printing on various plastic substrates. These solvent-based screen printing inks are designed to provide a high-gloss finish, fast drying times, and excellent adhesion to materials such as PVC, ABS, and acrylics.
Viscosity
The viscosity of the PVC-free screen-printing ink composition, obtained in Experiment 1 of the present disclosure was studied by using Sheen rotothinner viscometer as per standard test method ASTM D1200–23. The results are tabulated in Table 2 of the present disclosure.
From Table 2, it is observed that the viscosity of the screen-printing ink composition prepared in accordance with the present disclosure was in the range of 10 Poise to 40 Poise, which is desirable for printing ink.
Adhesion property
The adhesion performance of the PVC-free screen-printing ink composition of the present disclosure was studied. The adhesion performance was studied as per standard test method, i.e., Tape–test - D3359-23.
The results were noted after 24 hours of curing of the ink composition on a substrate. The substrates selected for adhesion test were polyvinyl chloride (PVC), polycarbonates, ABS, vinyl sheeting material (Hi-S-cal), Scotchal (vinyl substrate), and cellulose acetate substrate. The results are tabulated in Table 2 of the present disclosure.
From Table 2, it is observed that excellent scratch resistance is observed when tested after 24 hours of printing.
Screen stability test
The screen stability and self-solvency of the PVC-free screen-printing ink composition obtained in Experiment 1 were checked against PVC based product as per ASTMD1204. The results are tabulated in Table 2 of the present disclosure.
From Table 2 it is observed that the screen printing ink composition of the present disclosure has excellent screen stability.
Stability test/shelf life
The stability of the PVC-free screen-printing ink composition was tested as per standard method ASTM D1849. Ink stability test is an essential parameter for print performance. It reflects the shelf life of the product during transportation and storage. It is observed that, the PVC-free screen-printing ink composition of the present disclosure is stable for at least eight weeks which is better than PVC based ink composition series. Further, the results are tabulated in Table 2 of the present disclosure.
From Table 2, it is observed that the PVC-free ink composition of the present disclosure is more stable as compared to PVC based series product.
Table 2: Performance properties of the PVC-free screen-printing ink composition as performed in Experiment 1 in accordance with the present disclosure and comparison with PVC based ink composition.
Sr. No. Test Standard test method PVC-free screen-printing ink of present disclosure PVC based ink composition
1. Viscosity ASTM D1200 – 23
10 to 40 Poise 55- to 65 Poise
2. Adhesion property Tape–Test - 3359 - 23 Excellent adhesion on untreated substrates improper adhesion on untreated substrates
3 Screen stability for prints ASTMD1204 Excellent Screen stability on untreated substrates Poor screen stability on untreated substrates
4 Stability test ASTM D1849 At least eight Week stability with slight change in viscosity after 8 weeks eight week stability
5 Specific gravity ASTM D792 1 to 1.5 1 to 1.7
Example 19 (Preparation of the PVC-free overprint coating composition in accordance with the present disclosure
33 g of 2-ethybutyl acrylate (resin), 31.8 g of isopropyl acetoacetate (solvent), 18 g of butyl cellosolve acetate and 15 g of 2-ethylhexyl acetate were mixed under stirring at 1300 rpm, and at 60 °C for 3 hours to obtain a first mixture. 0.9 g of methylphenyl siloxane and 1.3 g of UV-328 (stabilizer) were added under stirring at 1000 rpm, and at 25 °C for 30 minutes to obtain the PVC-free overprint coating composition.
The observed viscosity of the PVC-free overprint coating composition was 18 Poise, the gloss% was 90% and specific gravity was 1.3.
Experiment 2: Performance properties of the PVC-free screen-printing ink composition and PVC-free overprint coating composition in accordance with the present disclosure
The PVC-free screen-printing ink composition of the present disclosure prepared as per Experiments 1 to 20, by using triple roll milling and by varying the pigments were studied for the performance properties The pigment dispersion of each screen-printing ink composition for respective pigment were measured as per standard test method D-1210-05.
Gloss test
The gloss determination of the PVC-free screen-printing ink composition was studied as per standard test method ISO2813:20145 (E). The results are tabulated in Table 1 of the present disclosure.
From Table 1, it is observed that the gloss% of the screen-printing composition is in the range of 70% to 90 %.
Density of print
The print density of the PVC-free screen-printing ink composition of the present disclosure was studied as per ASTM standard test method 7305 - 08a (2020). The results are tabulated in Table 1 of the present disclosure.
From Table 1, it is observed that the ‘density of print’ of the PVC-free screen-printing composition is in the range of 1 to 2.2, which is as per print performance properties.
Specific gravity
The specific gravity of the PVC-free screen-printing ink composition of the present disclosure was studied as per standard test method i.e., ASTM D792 Standard. The results are tabulated in Table 1 and Table 2 of the present disclosure.
From Table 1, it is observed that the specific gravity of the PVC-free screen-printing composition ranges from 1 to 1.5, which is within the specified range as per the standard ink properties.
Delta E (?E) values
The Delta E calculated from Lab values of all PVC-free inks of the present disclosure are within the tolerable range of 1 to 1.5. Delta E value measured here is the difference between all special colors of the present disclosure when compared with the PVC based ink series.
It was observed that all the pigments are compatible with the screen-printing ink composition of the present disclosure.
Out Door Testing (Weatherometer Test)
The weatherometer test (UVB313EL+) was studied as per ASTM standard test method ASTM-G-154-2016. The results are tabulated in Table 3 of the present disclosure. For outdoor testing, four different substrate were used- regular PVC, Lintec- Opaque Vinyl, 3M Scotchcal Film and Polycarbonate.
The ink compositions of Examples 2 to 15 were prepared by varying the pigment components in the formulation. Example 16 does not contain any pigment. Outdoor testing (Weatherometer UVB313EL+) test is carried out as per ASTM-G-154-2016 by simulating sunlight exposure and moisture aging of materials.
Table 3: Results of outdoor testing (weatherometer test)

Outdoor testing (Weatherometer UVB313EL+) As per ASTM-G-154-2016
Example Color Substrate printed with PVC-free overprint coating composition of Example 19 (Initial Gloss) 200 hours – 2000 hours
1
Black Regular PVC 73% First measurable reduction in gloss % was observed after 600 hours of exposure.
overall appearance still meets the applicable standard at 1500- 2000 hours
Lintec (Opaque Vinyl) 70%
3 M Scotchcal Film 70%
Polycarbonate 75%
2
Tinting Black Regular PVC 82% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 81%
3 M Scotchcal Film 81%
Polycarbonate 80%
3
White Regular PVC 63% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 64%
3 M Scotchcal Film 70%
Polycarbonate 69%
4
Opaque White Regular PVC 80% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 89%
3 M Scotchcal Film 88%
Polycarbonate 95%
5
Tinting White Regular PVC 70% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 82%
3 M Scotchcal Film 89%
Polycarbonate 895
6
Light Yellow Regular PVC 86% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.

Lintec (Opaque Vinyl 84%
3 M Scotchcal Film 87%
Polycarbonate 87%
7
Yellow Regular PVC 77% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 77%
3 M Scotchcal Film 80%
Polycarbonate 835
8
Orange Regular PVC 77% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 80%
3 M Scotchcal Film 79%
Polycarbonate 74%
9
Magenta Regular PVC 83% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 82%
3 M Scotchcal Film 84%
Polycarbonate 83%
10 Violet Regular PVC 84% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 84%
3 M Scotchcal Film 82%
Polycarbonate 84%
11
Red Regular PVC 78% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 78%
3 M Scotchcal Film 78%
Polycarbonate 82%
12
Pink Regular PVC 87% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 87%
3 M Scotchcal Film 87%
Polycarbonate 89%
13
Orange Regular PVC 85% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 86%
3 M Scotchcal Film 86%
Polycarbonate 85%
14
blue Regular PVC 76% First measurable reduction in gloss % was observed after 600 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 75%
3 M Scotchcal Film 75%
Polycarbonate 79%
15
Green Regular PVC 71% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 71%
3 M Scotchcal Film 71%
Polycarbonate 68%
18
Base
(Control) Regular PVC 86% First measurable reduction in gloss % was observed after 800 hours of exposure.
Overall appearance still meets the applicable standard at 1500- 2000 hours.
Lintec (Opaque Vinyl 86%
3 M Scotchcal Film 88%
Polycarbonate 95%
From Table 3 it is clear that outdoor life of all ink compositions are 1500 hours to 2000 hours.
A few ink compositions such as light yellow, orange, violet, red-blue shade, magenta, and green, exhibited the first measurable gloss reduction after 800 hours of exposure, indicating relatively better gloss retention. In contrast, the remaining colors showed gloss reduction after 600 hours.
This suggests that outdoor durability, in terms of gloss retention, varies slightly across different formulations. The performance in the weatherometer is significantly influenced by the ink composition, the interaction between ink ingredients, and the specific pigments used.
TECHNICAL ADVANCES AND ECONOMIC SIGNIFICANCE
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of PVC-free-solvent screen-printing ink composition that:
• is environment friendly;
• is suitable for indoor as well as outdoor applications;
• is compatible with various substrates;
• is ready to use ; and
? a process for the preparation of the PVC-free scree-printing ink composition, that is simple.
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 PVC-free composition comprising:
i. at least one resin in an amount in the range of 25 mass% to 50 mass%;
ii. at least one solvent in an amount in the range of 40 mass% to 70 mass%;
iii. at least one additive in an amount in the range of 0.2 mass% to 2 mass%;
iv. a stabilizer in an amount in the range of 1 mass% to 5 mass%;
v. at least one pigment in an amount in the range of 0 mass% to 30 mass%; and
vi. at least one dispersant in an amount in the range of 0 mass% to 2 mass%, and
wherein the mass% of each component is with respect to the total mass of said PVC-free composition.
2. The PVC-free composition as claimed in claim 1, wherein
• said resin is at least one selected from the group consisting of an acrylic based resin, a polyurethane based resin and an ester-based resin; wherein said acrylic based resin is selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate and butyl acrylate; said polyurethane based resin is selected from aliphatic polyurethanes; and said ester-based resin is selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate;
• said solvent is at least one selected from the group consisting of butyl cellosolve acetate, isophorone, C9 petroleum naphtha, cyclohexanone, diacetone alcohol, butyl glycol ether, isopropyl oxitol, diethylene glycol, 2-ethylhexyl acetate, isopropyl acetoacetate, ethoxypropyl acetate, derivatives of dibasic esters, propylene glycol monomethyl ether acetate, diacetone alcohol, n-methoxy-2-propanol, diethylene glycol monoethyl ether, diethylene glycol monoethyl ester and glycol ether based solvents;
• said additive is a slip additive and is at least one selected from the group consisting of multifunctional acrylic additives, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additives, hydroxy-functional polydimethylsiloxane and low odor epoxy ester; and
• said stabilizer is at least one selected from the group consisting of 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, hydroxyphenyl-triazine derivatives, 6-di-tert-pentylphenol, and hydroxyphenyl triazine.
3. The PVC-free composition as claimed in claim 1, wherein
• said pigment is at least one selected from the group consisting of inorganic pigments, metal based pigments and organic pigments; wherein said inorganic pigments are selected from the group consisting of titanium dioxide and carbon black; said metal based pigments are selected from pigment gold bronze and aluminum pigment; and said organic pigments are selected from the group consisting of dye lake pigments, azo-based pigments, benzimidazolone based pigments, phthalocyanine-based pigments, quinacridone-based pigments, anthraquinone-based pigments, triphenyl methane based pigment, dioxazine-based pigments, indigo-based pigments, thioindigo-based pigments, perylene–based pigments, perinone-based pigments, diketopyrrolopyrrole-based pigments, isoindolinone-based pigments, nitro-based pigments, pyranthrone-based pigments and indanethrone-based pigments; and
• said dispersant is at least one selected from the group consisting of polyether-modified polydimethylsiloxane, alcohol ethoxylates, fluorinated surfactants, benzene sulfonic acid, silicone surfactants, polyacrylate-based surfactants, and modified polyurethane surfactants.
4. The PVC-free composition as claimed in claim 1 is a PVC-free screen printing ink composition or a PVC-free overprint coating composition.
5. The PVC-free composition as claimed in claim 4, wherein said PVC-free composition is a PVC-free screen-printing ink composition comprises:
a) at least one resin in an amount in the range of 25 mass% to 40 mass%;
b) at least one solvent in an amount in the range of 40 mass% to 70 mass%;
c) at least one pigment in an amount in the range of 5 mass% to 30 mass%;
d) a stabilizer in an amount in the range of 1 mass% to 5 mass%;
e) a dispersant in an amount in the range of 0.1 mass% to 2 mass%; and
f) at least one additive in an amount in the range of 0.2 mass% to 2 mass%,
wherein the mass% of each component is with respect to the total mass of said PVC-free screen-printing ink composition.
6. The PVC-free composition as claimed in claim 5, wherein said PVC-free screen printing ink composition is characterized by having at least one of the following:
• viscosity in the range of 10 Poise to 40 Poise measured as per ASTM D1200-23;
• gloss percentage in the range of 70% to 92% measured as per ISO2813:20145(E);
• density of print in the range of 1 to 2.2 measured as per ASTM 7305-08a(2020); and
• specific gravity in the range of 1 to 1.5.
7. The PVC-free composition as claimed in claim 4, wherein said PVC-free overprint coating composition comprises:
a) at least one resin in an amount in the range of 30 mass% to 50 mass%;
b) at least one solvent in an amount in the range of 40 mass% to 70 mass%;
c) at least one additive in an amount in the range of 0.2 mass% to 2 mass%; and
d) a stabilizer in an amount in the range of 1 mass% to 5 mass%,
wherein the mass% of each component is with respect to the total mass of said overprint coating composition.
8. The PVC-free composition as claimed in claim 7, wherein said PVC-free overprint coating composition is characterized by having at least one of the following:
• viscosity in the range of 5 Poise to 40 Poise measured as per ASTM D1200-23;
• gloss percentage in the range of 80% to 95% measured as per ISO2813:20145(E); and
• specific gravity in the range of 1 to 1.5.
9. A process for the preparation of PVC-free composition as claimed in claim 1, said process comprising the following steps:
a) mixing predetermined amounts of at least one resin and at least one solvent under stirring at a first predetermined temperature and at a first predetermined stirring speed for a first predetermined time period to obtain a mixture;
b) optionally adding predetermined amounts of at least one pigment and a dispersant to said mixture under stirring at a second predetermined temperature and at a second predetermined stirring speed for a second predetermined time period followed by milling to obtain a homogeneous mixture; and
c) adding a predetermined amount of at least one additive and a stabilizer in said mixture in step a) OR said homogeneous mixture in step b) under stirring at a third predetermined temperature and at a third predetermined stirring speed for a third predetermined time period to obtain said PVC-free composition.
10. The process as claimed in claim 9, wherein
• said first predetermined temperature is in the range of 45 °C to 70 °C; and
• said second predetermined temperature and said third predetermined temperature are independently in the range of 20°C to 40°C.
11. The process as claimed in claim 9, wherein
• said first predetermined stirring speed is in the range of 1200 rpm to 1500 rpm; and
• said second predetermined stirring speed and said third predetermined stirring speed are independently in the range of 500 rpm to 1200 rpm.
12. The process as claimed in claim 9, wherein
• said first predetermined time period is in the range of 1 hour to 5 hours; and
• said second predetermined time period is in the range of 1 hour to 3 hours; and
• said third predetermined time period is in the range of 15 minutes to 60 minutes.
13. The process as claimed in claim 9, wherein said homogeneous mixture has an average particle size of less than 5 µm.

Dated this 10th Day of July 2025

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