DESC:FIELD
The present disclosure relates to screen-printing. Particularly, the present disclosure relates to a screen-printing ink composition.
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 stencilled 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.
Ecosolvent: The term “Ecosolvent” refers to an environment-friendly solvent, with comparatively less amount of volatile organic compounds (VOCs), thereby free from hazardous substances; and has no odour.
Slip additive: The term “Slip additive” refers to the compound to reduce friction, which when added to the inks, coating 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.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Printing inks are essential for printing on a wide range of substrates, including coated papers, uncoated papers, cardboard, and plastic substrates, which are commonly used in daily life. The main ingredients of ink composition are colorants (pigments/dyes) and vehicles (solvents/fluid medium). The printing inks are classified based on the vehicle used, such as water-based ink compositions, oil-based ink compositions, UV curable ink compositions and solvent-based ink compositions. The selection of the appropriate printing ink depends on the nature of the printing process and the type of substrate being used.
Oil-based ink compositions applied on substrates that undergo drying via the oxidation process, which typically requires a longer drying time. Furthermore, high humidity conditions can further slowdown the drying rate of the oil-based ink composition. Additionally, these ink compositions rely on lead-containing pigments to achieve the desired opacity, making them more expensive and posing potential health risks to humans.
Further UV-curable ink compositions contain monomers to improve the adhesion of ink on substrates, however, these monomers are harmful to human health and do not meet the strict standards aimed for product safety and environmental protection. Moreover, the adoption of UV-curable inks requires extra equipment, leading to higher costs thereby rendering the UV curable ink less commercially viable. Additionally, the curing process for the UV curable ink composition consumes more energy compared to traditional curing methods.
Still further solvent based ink compositions have a negative environmental impact due to the presence of volatile organic compounds (VOCs) that contribute to air pollution and health risks. Inhaling VOCs can cause respiratory irritation and other health issues, necessitating additional safety measures. These inks emit strong odors, requiring measures to address the working environment.
Furthermore, the known screen-printing ink compositions, i.e., water-based ink composition, oil-based ink composition, and solvent-based ink compositions, do not adhere effectively to untreated substrates due to their low surface energy. Due to which, the surface treatment becomes necessary to enhance adhesion of these known ink compositions. The surface treatment includes corona treatment, flame activation treatment, plasma treatment, chemical treatment, UV radiation treatment, X-ray treatment, laser radiation treatment, and the treatment by the application of reactive gases such as chlorination, sulfonation, fluorination oxidation and the like. However, these surface treatments can give rise to additional environmental concerns. Moreover, finding environment friendly and cost-effective ink composition remains a challenge in the printing industry.
Therefore, there is felt a need to provide a screen-printing ink 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.
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 screen-printing ink composition.
Yet another object of the present disclosure is to provide a screen-printing ink composition that is used for printing untreated plastic substrates.
Still another object of the present disclosure is to provide a screen-printing ink composition which is free from hazardous solvents.
Yet another object of the present disclosure is to provide a screen-printing ink composition that is economical and environment-friendly.
Another object of the present disclosure is to provide an ecosolvent based screen-printing ink composition that is efficient.
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 screen-printing ink composition.
The screen-printing ink composition comprises at least one resin in an amount in the range of 10 mass% to 70 mass% with respect to the total mass of the composition, at least one adhesion promoter in an amount in the range of 3 mass% to 15 mass% with respect to the total mass of the composition, at least one slip additive in an amount in the range of 0.1 mass% to 3 mass% with respect to the total mass of the composition, at least one surfactant in an amount in the range of 0.2 mass% to 5 mass% with respect to the total mass of the composition, at least one pigment in an amount in the range of 5 mass% to 30 mass% with respect to the total mass of the composition, at least one extender in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the composition and at least one ecosolvent in an amount in the range of 20 mass% to 70 mass% with respect to the total mass of the composition.
The resin is an acrylic resin selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, poly (isobutyl methacrylate), butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate, polyester acrylate, polyurethane acrylate and butyl acrylates.
The adhesion promoter is selected from the group consisting of poly-alpha-olefins, atactic polypropylene, ethylene vinyl-acetate, chlorinated polyolefin, and ethyl tri-ethoxy silane.
The slip additive is selected from the group consisting of multi-functional acrylic additive, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additive, and hydroxy-functional polydimethylsiloxane.
The surfactant is selected from the group consisting of benzene sulfonic acid, amine salt of benzene sulfonic acid, polyacrylate-based surfactant, modified polyurethane surfactant, ethoxylate surfactants, and silicone surfactant.
The pigment is selected from the group consisting of titanium white, pyrazolone orange, naphthol red AS, 3-Hydroxy-4-[(2-methyl-5-nitrophenyl)azo]-N-(2-methylphenyl)-2-naphthalenecarboxamide, phthalocyanine pigment blue 15:3, copper phthalocyanine green, 2,9-Dimethylquinacridone, carbazole dioxazine violet, carbon black, vermillion red, and emarald green.
The extender is selected from the group consisting of fumed silica, aluminium silicate, calcium carbonate, polyethylene wax, and polyurethane acrylic based extender.
The ecosolvent is selected from the group consisting of 2-ethylhexyl acetate, isopropyl acetoacetate, diethylene glycol, ethoxy propyl acetate and dibasic esters. The dibasic esters are selected from dimethyl adipate (DMA), dimethyl succinate (DMS) and diethyl adipate (DEA).
The composition is suitable for applying on at least one substrate selected from the group consisting of plastic, polypropylene, polyethylene, high impact polystyrene substrate (HIPS), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), acrylic polymer, cellulose acetate butyrate (CAB), polycarbonate (PC), polyethylene terephthalate (PET), coated polyester, batteries, chemical containers, circuit boards, packaging materials and electronic components.
The ink composition of the present disclosure is characterized by viscosity is in the range of 60 poise to 200 poise measured as per ASTM standard D1200–23;; gloss percentage in the range of 10% to 30% measured as per ISO2813:20145(E); and specific gravity in the range of 1 to 1.2 measured as per ASTM Standard D792.
DETAILED DESCRIPTION
The present disclosure relates to screen-printing. Particularly, the present disclosure relates to a screen-printing ink composition.
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.
Conventional screen-printing ink compositions, i.e., water-based ink composition, oil-based ink composition, and solvent-based ink composition, do not adhere effectively to untreated substrates due to their low surface energy. Due to which, the surface treatment becomes necessary to enhance adhesion of these conventional known ink compositions. The surface treatment includes corona treatment, flame activation treatment, plasma treatment, chemical treatment, UV radiation, X-ray treatment, laser radiation treatment, and the treatment by the application of reactive gases such as chlorination, sulfonation, fluorination oxidation and the like. However, these surface treatments can give rise to additional environmental concerns.
Moreover, finding environment friendly and cost-effective ink composition remains a challenge in the printing industry.
The present disclosure relates to a screen-printing ink composition.
In an aspect of the present disclosure, there is provided the screen-printing ink composition
The screen-printing ink composition comprises at least one resin in an amount in the range of 10 mass% to 70 mass% with respect to the total mass of the composition, at least one adhesion promoter in an amount in the range of 3 mass% to 15 mass% with respect to the total mass of the composition, at least one slip additive in an amount in the range of 0.1 mass% to 3 mass% with respect to the total mass of the composition, at least one surfactant in an amount in the range of 0.2 mass% to 5 mass% with respect to the total mass of the composition, at least one pigment in an amount in the range of 5 mass% to 30 mass% with respect to the total mass of the composition, at least one extender in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the composition and at least one ecosolvent in an amount in the range of 20 mass% to 70 mass% with respect to the total mass of the composition.
In an embodiment of the present disclosure, the resin is an acrylic resin selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, poly (isobutyl methacrylate), butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate, polyester acrylate, polyurethane acrylate and butyl acrylates. In an exemplary embodiment of the present disclosure the resin is poly (isobutyl methacrylate).
In an embodiment of the present disclosure, the adhesion promoter is selected from the group consisting of poly-alpha-olefins, atactic polypropylene, ethylene vinyl-acetate, chlorinated polyolefin, ethyl tri-ethoxy silane. In an exemplary embodiment of the present disclosure, the adhesion promoter is chlorinated polyolefin (CPP).
In an embodiment of the present disclosure, the slip additive is selected from the group consisting of multi-functional acrylic additive, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additive and hydroxy-functional polydimethylsiloxane. In an exemplary embodiment of the present disclosure, the slip additive is silicone oil.
In an embodiment of the present disclosure, the surfactant is selected from the group consisting of benzene sulfonic acid, amine salt of benzene sulfonic acid, polyacrylate-based surfactant, modified polyurethane surfactant, ethoxylate surfactants, and silicone surfactant. In an exemplary embodiment of the present disclosure, the surfactant is benzene sulfonic acid.
In an embodiment of the present disclosure, the pigment is selected from the group consisting of titanium white (PW6), pyrazolone orange (PO34), naphthol red AS (PR146), 3-Hydroxy-4-[(2-methyl-5-nitrophenyl)azo]-N-(2-methylphenyl)-2-naphthalenecarboxamide (pigment red 17 - PR17), phthalocyanine pigment blue 15:3 (Blue 15:3), copper phthalocyanine green (Green PG-7), 2,9-Dimethylquinacridone (Red-122), carbazole dioxazine violet (Violet-23), carbon black, vermillion red, and emarald green. In an exemplary embodiment of the present disclosure, the pigment is phthalocyanine pigment blue 15:3 (PB 15:3- Beta Blue pigment).
In an embodiment of the present disclosure, the extender is selected from the group consisting of fumed silica, aluminium silicate, calcium carbonate, polyethylene wax, and polyurethane acrylic based extender. In an exemplary embodiment of the present disclosure, the extender is fumed Silica.
In an embodiment of the present disclosure, the ecosolvent is selected from the group consisting of 2-ethylhexyl acetate, isopropyl acetoacetate, diethylene glycol, ethoxy propyl acetate and dibasic esters. In an embodiment of the present disclosure, the dibasic esters are selected from dimethyl adipate (DMA), dimethyl succinate (DMS) and diethyl adipate (DEA). In an exemplary embodiment of the present disclosure, the ecosolvent is 2-ethylhexyl acetate.
An ecosolvent or environment friendly solvents used in the present disclosure can easily biodegrade. The ecosolvent added in the ink compositions offers significant advantages by minimizing environmental impact and enhancing safety. It reduces volatile organic compound (VOC) emissions, leading to improved air quality and safer working conditions. They also facilitate compliance with stringent environmental regulations and can enhance print quality by offering comparable or superior performance in terms of color vibrancy and drying times. Additionally, ink compositions with ecosolvents have lower odor levels, making the printing process more pleasant and reducing the need for extensive ventilation.
The conventional screen-printing ink compositions such as water-based inks, oil-based inks, solvent-based inks and the like, do not adhere effectively to untreated substrates. Due to the low surface energy, there is necessity of surface treatment for the untreated substrate to enhance adhesion. However, the screen-printing ink composition of the present disclosure is suitable to print on untreated substrates.
In an embodiment of the present disclosure, the ink composition is suitable for applying on at least one substrate selected from the group consisting of plastic, polypropylene, polyethylene, high impact polystyrene substrate (HIPS), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), acrylic polymer, cellulose acetate butyrate (CAB), polycarbonate (PC), polyethylene terephthalate (PET), coated polyester, batteries, chemical containers, circuit boards, packaging materials and electronic components.
The screen printing composition is prepared by the following process.
The process for the preparation of the screen-printing ink composition comprises mixing predetermined amount of at least one resin, at least one adhesion promoter, at least one slip additive, at least one surfactant, at least one pigment, and at least one ecosolvent under stirring at a speed in the range of 500 rpm to 1200 rpm for a predetermined time period to obtain a first mixture.
The first mixture is milled to obtain a homogeneous mixture having a predetermined particle size range from 0.1 micron to 5 micron followed by adding at least one extender and mixing under stirring to obtain the screen-printing ink composition.
The screen-printing ink composition of the present disclosure is further mixed with ecosolvent to achieve a desired viscosity during printing.
In an embodiment of the present disclosure, the resin is an acrylic resin selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, poly (isobutyl methacrylate), butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate, polyester acrylate, polyurethane acrylate and butyl acrylates. In an exemplary embodiment of the present disclosure the resin is poly (isobutyl methacrylate).
In an embodiment of the present disclosure, the predetermined amount of resin is in the range of 10 mass% to 70 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the predetermined amount of resin is 38 mass%.
In an embodiment of the present disclosure, the adhesion promoter is selected from the group consisting of poly-alpha-olefins, atactic polypropylene, ethylene vinyl-acetate, chlorinated polyolefin, ethyl tri-ethoxy silane. In an exemplary embodiment of the present disclosure, the adhesion promoter is chlorinated polyolefin (CPP).
In an embodiment of the present disclosure, the predetermined amount of adhesion promoter is in the range of 3 mass% to 15 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the predetermined amount of adhesion promoter is 4.5 mass%.
In an embodiment of the present disclosure, the slip additive is selected from the group consisting of multi-functional acrylic additive, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additive and hydroxy-functional polydimethylsiloxane. In an exemplary embodiment of the present disclosure, the slip additive is silicone oil.
In an embodiment of the present disclosure, the predetermined amount of slip additive is in the range of 0.1 mass% to 3 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the predetermined amount of slip additive is 0.5 mass%.
In an embodiment of the present disclosure, the surfactant is selected from the group consisting of benzene sulfonic acid, amine salt of benzene sulfonic acid, polyacrylate-based surfactant, modified polyurethane surfactant, ethoxylate surfactants, and silicone surfactant. In an exemplary embodiment of the present disclosure, the surfactant is benzene sulfonic acid.
In an embodiment of the present disclosure, the predetermined amount of surfactant is in the range of 0.2 mass% to 5 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the predetermined amount of surfactant is 0.5 mass%.
In an embodiment of the present disclosure, the ecosolvent is selected from the group consisting of 2-ethylhexyl acetate, isopropyl acetoacetate, diethylene glycol, ethoxy propyl acetate and dibasic esters. In an embodiment of the present disclosure, the dibasic esters are selected from dimethyl adipate (DMA), dimethyl succinate (DMS) and diethyl adipate (DEA). In an exemplary embodiment of the present disclosure, the ecosolvent is 2-ethylhexyl acetate.
In an embodiment of the present disclosure, the predetermined amount of ecosolvent is in the range of 20 mass% to 70 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the ecosolvent is 43 mass%.
In an embodiment of the present disclosure, the predetermined time period is in the range of 1 hour to 4 hours. In an exemplary embodiment of the present disclosure, the predetermined time period is 2.5 hours.
In an embodiment of the present disclosure, the pigment is selected from the group consisting of titanium white (PW6), pyrazolone orange (PO34), naphthol red AS (PR146), 3-Hydroxy-4-[(2-methyl-5-nitrophenyl)azo]-N-(2-methylphenyl)-2-naphthalenecarboxamide (pigment red 17 - PR17), Phthalocyanine Pigment Blue 15:3 (Blue 15:3), copper phthalocyanine green (Green PG-7), 2,9-Dimethylquinacridone (Red-122), carbazole dioxazine violet (Violet-23), carbon black, vermillion red, and emarald green. In an exemplary embodiment of the present disclosure, the pigment is Phthalocyanine Pigment Blue 15:3 (PB 15:3 - Beta Blue).
In an embodiment of the present disclosure, the predetermined amount of the pigment is in the range of 5 mass% to 30 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the predetermined amount of the pigment is 5 mass%.
In an embodiment of the present disclosure, the predetermined particle size of the homogeneous mixture is in the range of 0.1 to 5 micron.
In an embodiment of the present disclosure, the extender is selected from the group consisting of fumed silica, aluminium silicate, calcium carbonate, polyethylene wax, and polyurethane acrylic based extender. In an exemplary embodiment of the present disclosure, the extender is fumed silica.
In an embodiment of the present disclosure, the predetermined amount of the extender is in the range of 5 mass% to 15 mass% with respect to the total mass of the composition. In an exemplary embodiment of the present disclosure, the predetermined amount of the extender is 9 mass%.
In an embodiment of the present disclosure, the ecosolvent is selected from the group consisting of 2-ethylhexyl acetate, isopropyl acetoacetate, diethylene glycol, ethoxy propyl acetate and dibasic esters. In an embodiment of the present disclosure, the dibasic esters are selected from dimethyl adipate (DMA), dimethyl succinate (DMS) and diethyl adipate (DEA). In an exemplary embodiment of the present disclosure, the ecosolvent is 2-ethylhexyl acetate.
In an embodiment of the present disclosure, the viscosity of the screen-printing ink composition in the range of 60 poise to 200 poise measured as per ASTM standard D1200–23. The screen-printing ink composition can be mixed with the ecosolvent having a printable viscosity in the range of 15 poise to 40 poise, when used on a substrate, during printing.
In an embodiment of the present disclosure, the screen-printing ink composition having gloss percentage in the range of 10% to 30 % measured as per ISO2813:20145(E).
In an embodiment of the present disclosure, the specific gravity of ink composition in the range of 1 to 1.2 measured as per ASTM Standard D792.
In an embodiment of the present disclosure, the density of print of the screen-printing ink composition in the range of 1 to 2.1 measured as per ASTM standard D7305 - 08a (2020).
The screen-printing ink composition of the present disclosure eliminates the necessity of surface treatment on low-surface energy materials. The ink composition ensures excellent adhesion and improved printability without the use of conventional surface treatment methods. Consequently, the environmental impact, safety concerns, and production costs associated with surface treatment processes are significantly reduced, providing a more sustainable and cost-effective solution.
In accordance with the present disclosure, the screen-printing ink composition provides enhanced adhesion and printability without any surface treatment, acid resistant, chemical resistant, scratch resistant and is suitable for application on a variety of substrates.
In accordance with the present disclosure, the screen-printing ink composition have improved adhesion on the substrate, improved drying time and comparatively less harmful volatile organic compounds (VOCs).
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
Example 1: A process for preparation of the screen-printing ink composition in accordance with the present disclosure.
38 g of poly (isobutyl methacrylate) (resin), 0.5 g of benzene sulfonic acid (surfactant), 4.5 g of Chlorinated polyolefin (CPP) (adhesion promoter), 0.5g of silicone oil (slip additive), 5 g of phthalocyanine pigment blue (PB 15:3- Beta Blue) (pigment) and 43 g of 2-ethylhexyl acetate (eco-solvent) were mixed together in ink mixing tub under stirring at 1000 rpm for 2.5 hours (predetermined time period) to obtain a first mixture.
The first mixture was milled under stirring at 1000 rpm for 40 minutes using triple roll milling to obtain a homogeneous mixture having particle size 0.1 to 5 microns followed by adding 9 g of Fumed Silica (extender) and mixing to obtain the screen-printing ink composition.
The screen-printing ink composition is further added in the ecosolvent to achieve desired viscosity of 15 poise to 40 poise.
Further, the properties of the so obtained screen-printing ink composition were studied.
Experiment 2
Properties of the screen-printing ink composition in accordance with the present disclosure
The screen-printing ink composition obtained in the Experiment 1 of the present disclosure, was tested against the Polydyne YN Series. The following tests were performed by using the standard test methods.
Polydyne YN series is a known screen-printing ink series of various pigments and it is specifically used for the treated substrates having surface energy above 38 dyne. Further, the Polydyne YN series is prepared by using the volatile organic solvents such as aromatic hydrocarbons, particularly C9 solvent (naphtha), which is hazardous to the environment.
Viscosity
The viscosity of the 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 were tabulated in Table 1 of the present disclosure.
From Table 1, it was observed that the viscosity of the screen-printing ink composition was 115 Poise, which is desirable for printing ink.
Adhesion property
The adhesion performance of the 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). The results were tabulated in Table 1 of the present disclosure.
From Table 1, it was observed that the 10 times hard rubbing of tape on printed substrate after 24 hours of printing.
The adhesion performance test was also carried out for other substrates such as polycarbonate and untreated or pretreated polyethylene and polypropylene, wherein the results showed similar properties as shown for polyvinyl chloride
Screen stability test
The screen stability and self-solvency of the screen-printing ink composition obtained in Experiment 1 were checked against Polydyne YN product. The results were tabulated in Table 1 of the present disclosure.
Stability test
The stability of the screen-printing ink composition was tested as per standard method ASTM D1849. Ink stability test was essential parameter for print performance. It reflects the shelf life of the product during transportation and storage. It was observed that, the screen-printing ink composition of the present disclosure was stable for eight week which is better than polydyne YN ink composition series. Further, the results were tabulated in Table 1 of the present disclosure.
From Table 1, it was observed that the present formulation provides the enhanced result in comparison against Polydyne YN product.
Table 1: Performance properties of the screen-printing ink composition as performed in Experiment 2 in accordance with the present disclosure and comparison with Polydyne YN
Sr. No. Test Standard test method Result of Present disclosure Polydyne YN
1. Viscosity ASTM D1200 – 23
115 Poise 100-120 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 Eight Week stability Six week stability
Experiment 3
Performance properties of the screen-printing ink composition by using various pigments in accordance with the present disclosure
The screen-printing ink composition of the present disclosure was prepared as per Experiment 1 by using triple roll milling except varying the pigments. Various pigments used for this study was provided in Table 2 below.
The pigment dispersion of each screen-printing ink composition for respective pigment were measured as per standard test method D-1210-05.
Table 2: Eight line colors and its corresponding pigments
Sr. No. Line color code of ink composition Description
1. YDE001 Black line color
2. YDE064 Seritone Yellow line color (GS)
3. YDE066 Seritone Yellow (RS)
4. YDE114 Seritone Orange
5. YDE164 Seritone Red (BS)
6. YDE165 Seritone Magenta
7. YDE127 Deep Violet/Seritone Violet
8. YDE230 Seritone Blue
The screen-printing ink composition with varying the pigments of Table 2 were further studied to test the properties such as gloss, density of print, specific gravity of ink and acid test.
Gloss test
The gloss determination of the screen-printing ink composition was studied as per standard test method ISO2813:20145 (E). The results are tabulated in table 3 of the present disclosure.
From Table 3, it was observed that the gloss% of the screen-printing composition was in the range of 10% to 30 % which is within the specified limit.
Density of print
The print density of the screen-printing ink composition were studied as per ASTM standard test method 7305 - 08a (2020). The results are tabulated in Table 3 of the present disclosure.
From Table 3, it was observed that the density of print of the screen-printing composition was in the range of 1 to 2.1, which is as per print performance properties.
Specific gravity of ink composition
The specific gravity of the screen-printing ink composition were studied as per standard test method i.e., ASTM D792 Standard. The results were tabulated in table 3 of the present disclosure.
From table 3, it was observed that the specific gravity of the screen-printing composition ranges from 1 to 1.2, which is within the specified range as per the standard ink properties.
Test for resistance against the acid
The screen-printing ink composition of the present disclosure was printed on polypropylene (PP) substrate. The printed polypropylene substrate was tested by contacting 35% w/w sulphuric acid (mineral acid).
ASTM method D747-13 is acid resistance of printed polypropylene films. This method evaluates the resistance of printed polypropylene films to sulfuric acid, simulating exposure to acidic environments.
As per acid test standard ASTM D747-13 method, the samples of all eight colors are tested, it was observed that delta E value means color change value between before and after test samples of all eight colors are coming below 1 means all eight colors passes the acid test. The results were tabulated in table 3 of the present disclosure.
Table 3: Performance properties of the eight line colors of screen-printing ink composition as performed in Experiment 3 in accordance with the present disclosure
Sr. No. Test Standard test method Result
1 Pigment dispersion D-1210-05 YDE 001 YDE 064 YDE 066 YDE 114 YDE 164 YDE 165 YDE 127 YDE 230
2 Gloss test ISO2813:20145 (E) 11.3% 11.5% 11.0% 12.0% 11.0% 11.7% 12.2% 12.1%
3 Density of print D7305-08a (2020) 2.1 1.998 2 1.114 1.25 1.22 1.31 1.125
4 Specific gravity of ink ASTM D792 1.12 1.115 1.2 1 1.125 1.11 1 1.2
5 Acid test ASTM D747-13 acid resistant acid resistant acid resistant acid resistant acid resistant acid resistant acid resistant acid resistant
6 l,a,b Value (Delta E value) ASTM E1347 with ASTM D2244 0.4 0.4 0.7 0.8 1.0 0.9 1.0 0.9
From Table 3, it was observed that Delta E calculated from Lab values of all inks of present disclosure were within tolerance limit below 1. Delta E value presents the difference in color information of sample and reference. Delta E value measured here were the difference between all special color of the present disclosure when compared with the Polydyne YN series colors.
It was observed that all delta E difference were within range means equal or less than 1.
From Table 3, it was observed that the screen-printing ink composition of the present disclosure was suitable for all the pigments used in the ink composition.
TECHNICAL ADVANCES AND ECONOMIC SIGNIFICANCE
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a screen-printing ink composition that:
• has enhanced adhesion and printability;
• has excellent acid, and chemical resistance property when applied to non-treated polypropylene, and high impact polystyrene substrate (HIPS);
• provides improved scratch resistance;
• is suitable for printing on a variety of substrates;
• is free from hazardous compounds;
• is economical and environment friendly; and
• avoids the requirement of surface pre-treatment of the substrate.
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 screen-printing ink composition comprising:
a) at least one resin in an amount in the range of 10 mass% to 70 mass% with respect to the total mass of the composition;
b) at least one adhesion promoter in an amount in the range of 3 mass% to 15 mass% with respect to the total mass of the composition;
c) at least one slip additive in an amount in the range of 0.1 mass% to 3 mass% with respect to the total mass of the composition;
d) at least one surfactant in an amount in the range of 0.2 mass% to 5 mass% with respect to the total mass of the composition;
e) at least one pigment in an amount in the range of 5 mass% to 30 mass% with respect to the total mass of the composition;
f) at least one extender in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the composition; and
g) at least one ecosolvent in an amount in the range of 20 mass% to 70 mass% with respect to the total mass of the composition.
2. The ink composition as claimed in claim 1, wherein said resin is an acrylic resin selected from the group consisting of methyl methacrylate, isobutyl methyl acrylate, poly (isobutyl methacrylate), butyl prop-2-enoate, polymethyl methacrylate, 2-ethylbutyl acrylate, polyester acrylate, polyurethane acrylate and butyl acrylates.
3. The ink composition as claimed in claim 1, wherein said adhesion promoter is selected from the group consisting of poly-alpha-olefins, atactic polypropylene, ethylene vinyl-acetate, chlorinated polyolefin, and ethyl tri-ethoxy silane.
4. The ink composition as claimed in claim 1, wherein said slip additive is selected from the group consisting of multi-functional acrylic additive, silicone oil, methylphenyl siloxane, modified polydimethylsiloxane additive and hydroxy-functional polydimethylsiloxane.
5. The ink composition as claimed in claim 1, wherein said surfactant is selected from the group consisting of benzene sulfonic acid, amine salt of benzene sulfonic acid, polyacrylate-based surfactant, modified polyurethane surfactant, ethoxylate surfactants, and silicone surfactant.
6. The ink composition as claimed in claim 1, wherein said pigment is selected from the group consisting of titanium white, pyrazolone orange, naphthol red AS, 3-Hydroxy-4-[(2-methyl-5-nitrophenyl)azo]-N-(2-methylphenyl)-2-naphthalenecarboxamide, phthalocyanine pigment blue 15:3, copper phthalocyanine green, 2,9-Dimethylquinacridone, carbazole dioxazine violet, carbon black, vermillion red, and emarald green .
7. The ink composition as claimed in claim 1, wherein said extender is selected from the group consisting of fumed silica, aluminium silicate, calcium carbonate, polyethylene wax, and polyurethane acrylic based extender.
8. The ink composition as claimed in claim 1, wherein said ecosolvent is selected from the group consisting of 2-ethylhexyl acetate, isopropyl acetoacetate, diethylene glycol, ethoxy propyl acetate and dibasic esters; and wherein said dibasic esters are selected from dimethyl adipate (DMA), dimethyl succinate (DMS) and diethyl adipate (DEA).
9. The ink composition as claimed in claim 1, wherein said composition is suitable for applying on at least one substrate selected from the group consisting of plastic, polypropylene, polyethylene, high impact polystyrene substrate (HIPS), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), acrylic polymer, cellulose acetate butyrate (CAB), polycarbonate (PC), polyethylene terephthalate (PET), coated polyester, batteries, chemical containers, circuit boards, packaging materials and electronic components.
10. The ink composition as claimed in claim 1 is characterized by
• viscosity in the range of 60 poise to 200 poise measured as per ASTM standard D1200–23;
• gloss percentage in the range of 10% to 30% measured as per ISO2813:20145(E); and
• specific gravity in the range of 1 to 1.2 measured as per ASTM Standard D792.

Dated this 5th day of August, 2024

_______________________________
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