Sprayable aqueous ink system
By developing a water-based ink system containing thermally activated resin and high-temperature crosslinking resin, the challenges of 3D surface spraying and environmental protection requirements have been solved, achieving efficient spraying on 3D glass substrates and forming a tough coating film.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2026-04-03
AI Technical Summary
Existing inks are difficult to apply effectively to 3D surfaces, and the environmental requirements for solvent-based inks are becoming increasingly stringent. There is a need to develop high-performance water-based inks that meet environmental requirements and are suitable for 3D glass substrates.
A sprayable water-based ink system is provided, comprising a first water-based ink composition and a second water-based ink composition, each comprising a thermally activated resin and a high-temperature crosslinking resin, which are cured by heating to form a coating film, suitable for 3D glass substrates.
It achieves efficient spraying on 3D glass substrates to form a tough coating film with good adhesion and flexibility, meets environmental protection standards, and has low VOC content.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of inks, and more specifically to sprayable water-based ink systems. Background Technology
[0002] Ink is typically applied to the surface of the object / substrate by printing. However, printing has limitations for applying ink to non-planar surfaces, such as 3D surfaces. With the widespread use of 3D glass in the consumer electronics industry, it is necessary to develop an ink that can be sprayed onto 3D glass substrates.
[0003] Furthermore, with increasingly stringent national environmental protection requirements, the use of solvent-based inks is facing growing restrictions, while the market demand for water-based inks continues to expand. Therefore, providing a high-performance water-based ink is currently a hot research topic in the ink industry. Summary of the Invention
[0004] The inventors have conducted extensive research and developed a sprayable water-based ink system that meets environmental protection requirements while possessing excellent overall performance.
[0005] The present invention provides a sprayable water-based ink system comprising a first water-based ink composition and a second water-based ink composition, wherein the first ink composition comprises a binder comprising a thermally activated resin that is activated at a temperature of at least 120°C, and wherein the second ink composition comprises a binder comprising a high-temperature crosslinking resin that is crosslinked at a temperature of at least 120°C.
[0006] The present invention also provides a coated substrate, comprising a substrate and the above-described water-based ink system coated on at least a portion of the substrate.
[0007] The present invention further provides a method for processing a glass substrate, comprising:
[0008] The above-described water-based ink system is applied to at least a portion of a substrate, wherein the first water-based ink composition is applied to the substrate prior to the second water-based ink composition. Attached Figure Description
[0009] Figure 1 The 3D glass substrates sprayed with the water-based ink systems of Examples 1-3 are shown. Detailed Implementation
[0010] In this application, unless otherwise expressly stated, the use of the singular includes the plural and the plural includes the singular. For example, although “a” resin is referred to herein, one or more of the same substance may be used.
[0011] In this application, the terms "comprising," "including," and "containing" are not intended to limit the invention and exclude any variations or additions. Furthermore, although the invention has used terms such as "comprising" to describe ink compositions, preparation methods, etc., the ink compositions, preparation methods, etc., detailed herein may also be described as "consisting substantially of..." or "consisting of...". In this case, "consisting substantially of..." means that any additional components will not substantially affect the properties of the film layer formed by the ink composition.
[0012] In this application, unless otherwise expressly stated, “or” is used to mean “and / or”, even if “and / or” may be explicitly used in certain circumstances. Furthermore, it should be understood that any numerical range listed herein is intended to include all subranges contained therein. For example, the range “1 to 10” is intended to include all subranges between the listed minimum value 1 and the listed maximum value 10 (inclusive), that is, all subranges having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.
[0013] Except as explicitly stated in the embodiments or otherwise, it should be considered that the numerical values of all representative components, etc., used in the specification and claims are all subject to variation in all cases according to the term "about". Therefore, unless stated to the contrary, the numerical parameters listed in the following specification and claims are approximate values and may vary according to the performance desired by the invention. This is not intended to limit the application of the doctrine of equivalence to the scope of the claims. Each numerical parameter should be interpreted in significant figures and subject to ordinary rounding.
[0014] Although the numerical ranges and parameters described in this invention are approximate, the numerical values listed in the specific embodiments are recorded as accurately as possible. However, any numerical value inherently possesses a certain degree of error, which is a necessary consequence of the standard deviation derived from the corresponding measurement method.
[0015] As described above, the present invention relates to a sprayable water-based ink system comprising a first water-based ink composition and a second water-based ink composition, wherein the first ink composition comprises a binder comprising a thermally activated resin that is activated at a temperature of at least 120°C, and wherein the second ink composition comprises a binder comprising a high-temperature crosslinking resin that is crosslinked at a temperature of at least 120°C.
[0016] As used herein, “sprayable” means that the ink composition in the ink system is suitable for application by a spraying apparatus, in which case the ink composition has an initial viscosity of 90 KU or lower (measured using a Brookfield KU-3 viscometer according to ASTM D562-10 2023) and can be diluted to an application viscosity of 15–35 seconds (measured using a Zahn 3# viscosity cup). As used herein, “first water-based ink composition,” “first water-based ink,” or “first ink” refers to a first water-based ink composition before drying or curing, i.e., it is not dried or cured; “second water-based ink composition,” “second water-based ink,” or “second ink” refers to a second water-based ink composition before drying or curing, i.e., it is not dried.
[0017] The first water-based ink composition according to the present invention is a two-package composition. The "two-package composition" refers to a composition in which the components are packaged separately, and the two packages are mixed in precise proportions before use.
[0018] The second water-based ink composition according to the present invention can be a two-packaging composition. Alternatively, the second water-based ink composition according to the present invention can be a single-packaging composition. The term "single-packaging composition" means that all components of the ink are contained in a single package, thus offering the advantage of ease of use.
[0019] The first water-based ink composition according to the present invention can be a thermosetting composition. The second water-based ink composition according to the present invention can be a thermosetting composition. The thermosetting composition, upon curing, irreversibly forms a coating film that does not melt upon reheating and is insoluble in a solvent. Hereinafter, the term "curing" means that at least a portion of the components in the ink composition are polymerized and / or crosslinked, or dried to form a hardened coating film.
[0020] The first water-based ink composition according to the present invention can be cured by heat. The second water-based ink composition according to the present invention can be cured by heat. The first and second water-based ink compositions according to the present invention can each be cured at 140-150°C for 20-35 minutes. Suitably, the first / second water-based ink composition according to the present invention can be fully cured at 150°C for 30 minutes. "Fully cured" means that the ink layer has a MEK double rub value of at least 50, such as 70.
[0021] The ink layer formed by the first water-based ink composition according to the present invention can have a dry film thickness of 30 to 40 μm. The ink layer formed by the second water-based ink composition according to the present invention can have a dry film thickness of 15 to 20 μm. The "dry film thickness" refers to the thickness of the ink layer after it has fully cured.
[0022] The first water-based ink composition according to the present invention may have a solid content of 20-35 wt%. The second water-based ink composition according to the present invention may have a solid content of 20-35 wt%. Hereinafter, "solid content" refers to the ratio of the mass of the ink composition remaining after drying to the total mass of the original composition.
[0023] The first water-based ink composition according to the present invention can have shear-thinning properties. The second water-based ink composition according to the present invention can have shear-thinning properties. The shear-thinning property refers to the fact that the viscosity of the ink composition decreases with increasing shear force; that is, the viscosity of the ink composition is high at low shear forces and low at high shear forces.
[0024] The first water-based ink composition according to the present invention can have an initial viscosity of 60-80 KU at room temperature (measured using a Brookfield KU-3 viscometer according to ASTM D562-10 2023). The second water-based ink composition according to the present invention can have an initial viscosity of 60-80 KU at room temperature (measured using a Brookfield KU-3 viscometer according to ASTM D562-10 2023). The initial viscosity is the storage viscosity of the ink composition, i.e., before thinning. The first water-based ink composition according to the present invention can have an application viscosity of 15-35 seconds at room temperature (measured using a Zahn 3# viscosity cup). The second water-based ink composition according to the present invention can have an application viscosity of 15-35 seconds at room temperature (measured using a Zahn 3# viscosity cup). The application viscosity can be measured under the following conditions: after dispersion at 700-1000 rpm for 15-30 minutes in a disperser to achieve sufficient dispersion, followed by thinning at room temperature (composition to water mass ratio of 100:0-20) and measurement. The room temperature refers to 15-30℃, such as 23℃.
[0025] The first and second water-based ink compositions, possessing the aforementioned specific properties, are suitable for spray application and are advantageous for coating non-planar surfaces such as 3D surfaces, thus overcoming printing problems. The first and second water-based ink compositions according to the present invention are sprayable.
[0026] In this document, the term "aqueous" means that the solvent of the ink composition contains at least 50 wt% water based on the total weight of the solvent. The aqueous ink system according to the invention has a low VOC content. As used herein, the term "VOC (volatile organic compound)" refers to any organic compound with a boiling point less than or equal to 250°C (482°F) measured at a standard atmospheric pressure of 101.3 kPa. Organic solvents are generally the primary source of VOCs. Suitably, the VOC content of the aqueous ink system according to the invention is no more than 200 g / L. Suitably, the VOC content of the first aqueous ink composition according to the invention can be 70-80 g / L. Suitably, the VOC content of the second aqueous ink composition according to the invention can be 80-90 g / L. The VOC value is obtained in an anhydrous manner and can be obtained by detecting the content of each organic compound component in the coating using gas chromatography and then adding the contents of each component together.
[0027] In this document, "binder" refers to components in an ink composition that can crosslink / polymerize with each other or dry to form a film, such as resins.
[0028] In this document, "thermally activated resin" refers to a resin that produces a certain viscosity and fluidity when the temperature is above a certain critical value (near the glass transition temperature), which helps to provide adhesion between the substrate and the interlayer.
[0029] In this document, "high-temperature crosslinking resin" refers to a resin that undergoes self-crosslinking or crosslinking with other components under high-temperature conditions (i.e., above 120°C). Suitable high-temperature crosslinking resins for use in second water-based ink compositions may include hydroxyl- and / or carboxyl-containing resins and amino resins.
[0030] The heat-activated resin suitable for use in the first water-based ink may include polyurethane. The polyurethane refers to a polymer whose repeating units comprise urethane groups. The polyurethane may include at least 50 wt% organic units linked by urethane bonds, for example, at least 70 wt% organic units, such as polymers with at least 90 wt% organic units. In this document, the organic units comprise one or more residues selected from simple diols, such as butanediol, polyester diol, polyether diol, polycarbonate diol, etc.
[0031] Suitably, the polyurethane may include an aliphatic polyurethane. The aliphatic polyurethane can be prepared by reacting an alcohol with an aliphatic isocyanate. The aliphatic isocyanate includes one or more selected from the group consisting of hexamethylene diisocyanate (HDI), isoflurane diisocyanate (IPDI), and dicyclohexylmethane-4,4'-diisocyanate (HMDI).
[0032] Suitablely, the polyurethane may have a tensile strength at break of 600-800%, which can be determined according to ASTM D882. For example, the polyurethane may have a tensile strength at break of 650%, 700%, or 750%. For example, the polyurethane may have a tensile strength at break of 600% or higher, 650% or higher, or 700% or higher, and / or 800% or lower, or 750% or lower. For example, the tensile strength at break of the polyurethane may be 650-750%, 700-750%, or any other combination of the above end values. The elongation at break refers to the ratio of the length of the material after being stretched to its length before being stretched when subjected to an external force until it breaks. Suitablely, the polyurethane has a tensile strength of 1-5 N / mm. 2 The 100% modulus can be determined according to ASTM D882. For example, the polyurethane can have a modulus of 2 N / mm. 2 3 N / mm 2 or 4 N / mm 2 100% modulus. For example, the polyurethane may have a modulus of 1 N / mm. 2 Or higher, 2 N / mm 2 Or higher, or 3 N / mm 2 Or higher, and / or 5 N / mm 2 Or lower, or 4 N / mm 2 Or even lower 100% modulus. For example, the 100% modulus of the polyurethane can be 1~4 N / mm. 2 2~4 N / mm 2 Or within any other combination of the above endpoints. The 100% modulus refers to the tensile strength at 100% elongation.
[0033] Suitably, the polyurethane can be in the form of a dispersion. The solid content of the polyurethane dispersion can be 35-45 wt%, which can be determined according to DIN EN ISO 3251 (2019). The "solid content" refers to the percentage of the mass remaining after evaporation relative to the original dispersion mass. Suitably, the pH value of the polyurethane dispersion can be no more than 8.5, such as 7-8.5, which can be determined with reference to DIN ISO 976. Suitably, the viscosity of the polyurethane dispersion at room temperature is no more than 220 cps, such as 20-200 cps, which can be determined with reference to ISO 1652 using Brookfield RVT Spindle 1 / rpm20 / factor 5. Room temperature refers to 15-30°C, such as 23°C.
[0034] The polyurethane possesses suitable tensile strength at break and 100% modulus, enhancing the ink's flexibility. This polyurethane characteristic allows the ink to maintain relatively high flexibility even at -60°C, increasing its tensile strength. Furthermore, the polyurethane exhibits good film-forming properties and possesses a certain degree of self-crosslinking at high temperatures (i.e., above 120°C), resulting in relatively good mechanical properties (such as good initial adhesion) even without the addition of a crosslinking agent.
[0035] Based on the solid weight of the thermally activated resin, the thermally activated resin may include at least 75 wt%, suitably at least 80 wt%, such as 85 wt% or higher, for example 90 wt% or higher, such as 95 wt% or higher, or even 100 wt% of the aforementioned polyurethane resin.
[0036] Based on the total weight of the first water-based ink composition, the polyurethane content may be about 10 wt% or higher, suitably about 15 wt% or higher, suitably about 20 wt% or higher, and / or about 35 wt% or lower, such as about 30 wt% or lower, suitably about 25 wt% or lower. Based on the total weight of the first water-based ink composition, the polyurethane content may be about 10 to 35 wt%, suitably 15 to 30 wt%, such as 20 to 25 wt%, or within any other combination of these endpoints.
[0037] The thermally activated resin constitutes the binder of the first water-based ink composition. Suitably, the thermally activated resin may constitute at least 80 wt% of the total solids of the binder of the first water-based ink composition. For example, the thermally activated resin solids may constitute 85 wt% or more, 90 wt% or more, 95 wt% or more, or 100 wt% of the total solids of the binder of the first water-based ink composition.
[0038] The first water-based ink composition according to the invention may further include pigments and fillers. The pigments and fillers can provide color, effects, and / or functionality to the ink, and include coloring pigments and fillers (also known as extender pigments). Suitably, the pigments include inorganic pigments. Compared to organic pigments, inorganic pigments improve the UV resistance of water-based inks. Suitably, the inorganic pigments may include inorganic metal oxides, such as titanium dioxide, iron oxide red, etc., or carbon black. Suitably, the fillers include fumed silica.
[0039] In the first water-based ink composition, the solid weight ratio of the binder to the inorganic pigment can be from 5:2 to 5:10. For example, the solid weight ratio of the binder to the inorganic pigment can be 5:3, 5:4, 5:5, 5:6, 5:7, 5:8, or 5:9. For example, the solid weight ratio of the binder to the inorganic pigment can be 5:2 or lower, 5:3 or lower, 5:4 or lower, 5:5 or lower, or 5:6 or lower, and / or 5:9 or higher, 5:8 or higher, or 5:7 or higher. For example, the solid weight ratio of the binder to the inorganic pigment can be 5:2 to 5:8, 5:2 to 5:7, or any other combination of the above-mentioned values.
[0040] Based on the total weight of the first water-based ink composition, the content of pigments and fillers can be 10-50 wt%.
[0041] The first aqueous ink composition according to the invention may further include an adhesion promoter. Suitably, the adhesion promoter includes a silane coupling agent. Suitably, the silane coupling agent includes an epoxy functional group. Based on the total weight of the first aqueous ink composition, the content of the adhesion promoter may be 1 to 6 wt%, for example 2 to 5 wt%.
[0042] The first water-based ink composition according to the invention may further include a defoamer. The defoamer can inhibit the formation of bubbles during the production process and facilitate the escape or collapse of already formed bubbles. Suitably, the defoamer may include a siloxane-based defoamer. Based on the total weight of the first water-based ink composition, the content of the defoamer may be 0 to 2 wt%, for example, 0.1 to 1.5 wt%.
[0043] The first water-based ink composition according to the invention may further include a rheology modifier. The rheology modifier can effectively adjust viscosity, ensuring excellent workability and preventing fat edges. Suitably, the rheology modifier may include a polyurethane thickener. Based on the total weight of the first water-based ink composition, the content of the rheology modifier may be 0 to 2 wt%, for example, 0.1 to 1.5 wt%.
[0044] The first water-based ink composition according to the invention may further include a leveling agent. The leveling agent can improve flowability and processability to provide a coating with smoothness. Suitably, the leveling agent may include a silicone-based leveling agent. Based on the total weight of the first water-based ink composition, the content of the leveling agent may be 0 to 2 wt%, for example, 0.1 to 1.5 wt%.
[0045] The first aqueous ink composition according to the invention may further include a solvent. The solvent primarily comprises water, i.e., water accounts for at least 50 wt% of the solvent mass. The solvent may also include an organic solvent to aid in the compatibility of the components in the ink composition. Suitably, the organic solvent includes ether solvents. Based on the total weight of the first aqueous ink composition, the water content may be 20-40 wt%. Based on the total weight of the first aqueous ink composition, the organic solvent content may be 1-10 wt%.
[0046] Suitablely, the first water-based ink composition according to the invention can be a two-component composition comprising at least one or more ingredients, wherein the first component comprises: a polyurethane resin, pigments and fillers, optional additives and solvents, and the second component comprises an adhesion promoter. In the two-component composition, the adhesion promoter comprising a silane coupling agent and the filler such as silica are packaged separately to avoid the reaction between the two causing an increase in viscosity and / or the failure of the coupling agent.
[0047] The high-temperature crosslinking resin used in the second water-based ink composition may include hydroxyl- and / or carboxyl-containing resins and amino resins. The hydroxyl- and / or carboxyl-containing resins may include hydroxyl-functionalized (meth)acrylate-styrene polymers. Hydroxyl functionalization means that the polymer contains active hydroxyl groups that participate in the crosslinking reaction. The (meth)acrylate-styrene polymer is a polymer obtained by polymerizing a mixture of monomers including methacrylate monomers and / or acrylic monomers, and styrene monomers.
[0048] Suitably, the hydroxyl-functionalized (meth)acrylic acid-styrene polymer may have a hydroxyl value of 60 to 150 mg KOH / g. For example, the hydroxyl-functionalized (meth)acrylic acid-styrene polymer may have a hydroxyl value of 60 mg KOH / g or higher, 80 mg KOH / g or higher, or 110 mg KOH / g or higher, and / or 150 mg KOH / g or lower, 130 mg KOH / g or lower, or 120 mg KOH / g or lower. For example, the hydroxyl value of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer may be 80-130 mg KOH / g, 80-120 mg KOH / g, or any other combination of the above-mentioned end values. The hydroxyl value refers to the number of milligrams of potassium hydroxide (KOH) equivalent to hydroxyl groups in 1 gram of resin. The hydroxyl value may be determined according to DIN EN ISO 469292: 2016.
[0049] Suitably, the hydroxyl-functionalized (meth)acrylic acid-styrene polymer may have an MFFT (minimum film-forming temperature) of 40–80 °C. For example, the hydroxyl-functionalized (meth)acrylic acid-styrene polymer may have an MFFT of 40 °C or higher, or 50 °C or higher, and / or 80 °C or lower, 70 °C or lower, or 60 °C. For example, the MFFT of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer may be 50–70 °C, 50–60 °C, or any other combination of the above end values. The MFFT may be determined using an MFFT-BAR minimum film-forming temperature tester (RHOPOINT MFFT-60 / MFFT-90) according to ASTM D 2354-10 (2018) standard.
[0050] Suitably, the hydroxyl-functionalized (meth)acrylic acid-styrene polymer can be in the form of an emulsion. The solid content of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer emulsion can be 40-45 wt%, which can be determined according to DIN EN ISO 3251 (2019). "Solid content" refers to the percentage of the original emulsion mass remaining after evaporation. Suitably, the pH value of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer emulsion can be greater than 1.0 to 3.0, which can be determined with reference to DIN ISO 976. Suitably, the viscosity of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer emulsion at room temperature is 20-50 cps, which can be determined with reference to ISO 1652 using a Brookfield RVTSpindle 1 / rpm 20 / factor 5. Room temperature refers to 15-30°C, such as 23°C.
[0051] Based on the total weight of the second water-based ink composition, the content of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer can be about 5 wt% or higher, suitably about 8 wt% or higher, suitably about 10 wt% or higher, and / or about 20 wt% or lower, such as about 18 wt% or lower, suitably about 15 wt% or lower. Based on the total weight of the second water-based ink composition, the content of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer can be about 5 to 20 wt%, suitably 8 to 18 wt%, such as 10 to 15 wt%, or within any other combination of these end values.
[0052] The hydroxyl and / or carboxyl-containing resin may also include polyurethane. The polyurethane may include polyether-type polyurethane. The polyether-type polyurethane refers to polyurethane that can be prepared from polyisocyanates and polyether polyols. Suitably, the polyurethane may have an acid value of 10–40 mgKOH / g. For example, the polyurethane may have an acid value of 10 mgKOH / g or higher, or 20 mgKOH / g or higher, and / or 40 mgKOH / g or lower, or 30 mgKOH / g or lower. For example, the acid value of the polyurethane may be 10–30 mgKOH / g, or within any other combination of the above-mentioned values. The “acid value” refers to the number of milligrams of potassium hydroxide required to neutralize the free acid in 1 gram of resin. The acid value may be determined according to DIN EN ISO 2114:2002-06.
[0053] Suitablely, the polyurethane may have a Tg (glass transition temperature) of 90–120 °C. For example, the polyurethane may have a Tg of 90 °C or higher, or a Tg of 100 °C or higher, and / or a Tg of 120 °C or lower, or a Tg of 110 °C or lower. For example, the Tg of the polyurethane may be 90–110 °C, or within any other combination of the above-mentioned extreme values. The glass transition temperature is determined by dynamic thermomechanical analysis (DMA) using a TA Instruments Q800 instrument with the following parameters: frequency 10 Hz, amplitude 5 mm, temperature ramp -100 °C to 250 °C, and Tg is determined as the peak value of the tanδ curve according to ASTM E1356-23.
[0054] Suitably, the polyurethane can be in the form of a dispersion. The solid content of the polyurethane dispersion can be 30-35 wt%, which can be determined according to DIN EN ISO 3251 (2019). The "solid content" refers to the percentage of the mass remaining after evaporation relative to the original dispersion mass. Suitably, the pH value of the polyurethane dispersion can be 7.0-9.0, which can be determined with reference to DIN ISO 976. Suitably, the viscosity of the polyurethane dispersion at room temperature is 50-150 cps, which can be determined with reference to ISO 1652 using Brookfield RVT Spindle 1 / rpm 20 / factor 5. Room temperature refers to 15-30°C, such as 23°C.
[0055] Based on the total weight of the second water-based ink composition, the polyurethane content may be about 5 wt% or higher, suitably about 8 wt% or higher, suitably about 10 wt% or higher, and / or about 20 wt% or lower, such as about 18 wt% or lower, suitably about 15 wt% or lower. Based on the total weight of the second water-based ink composition, the polyurethane content may be about 5 to 20 wt%, suitably 8 to 18 wt%, such as 10 to 15 wt%, or within any other combination of these endpoints.
[0056] In the second water-based ink composition, the solid weight ratio of the above-mentioned hydroxyl-functionalized (meth)acrylic-styrene polymer to the polyurethane can be from 1:1 to 1:2.5, suitably from 1:1 to 1:2. For example, the solid weight ratio of the above-mentioned hydroxyl-functionalized (meth)acrylic-styrene polymer to the polyurethane can be 1:1 or lower, 1:1.1 or lower, 1:1.2 or lower, 1:1.3 or lower, 1:1.4 or lower, or 1:1.5 or lower, and / or 1:2 or higher, 1:1.9 or higher, 1:1.8 or higher, 1:1.7 or higher, or 1:1.6 or higher, such as 1.1 to 1:1.9, or any other combination of the above-mentioned end values. For example, the solid weight ratio of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer to the polyurethane can be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2.
[0057] The hydroxyl-containing and / or resin may also include styrene-propyl methacrylate, which can aid in pigment dispersion. The styrene-propyl methacrylate differs from the aforementioned hydroxyl-functionalized (meth)acrylic-styrene polymers. The styrene-propyl methacrylate refers to a polymer copolymerized from a mixture comprising methacrylic acid monomers and styrene monomers. Suitably, the styrene-propyl methacrylate may have an MFFT (minimum film-forming temperature) of 60–100 °C. For example, the styrene-propyl methacrylate may have an MFFT of 60 °C or higher, 70 °C or higher, or 80 °C or higher, and / or 100 °C or lower, or 90 °C or lower. For example, the MFFT of the styrene-propyl methacrylate may be 70–100 °C, 70–90 °C, or any other combination of the aforementioned values. The MFFT may be determined using an MFFT-BAR minimum film-forming temperature tester (UK RHOPOINT minimum film-forming temperature tester MFFT-60 / MFFT-90) according to the ASTM D2354-10 (2018) standard.
[0058] The styrene methacrylate can be in the form of an emulsion. The solid content of the styrene methacrylate emulsion can be 49-51 wt%, which can be determined according to DIN EN ISO 3251 (2019). "Solid content" refers to the percentage of the original emulsion mass remaining after evaporation. Suitablely, the pH value of the styrene methacrylate emulsion can be 7.0-8.0, which can be determined with reference to DIN ISO 976. Suitablely, the viscosity of the styrene methacrylate emulsion at room temperature is 700-1000 cps, which can be determined with reference to ISO 1652 using a Brookfield RVT Spindle 1 / rpm 20 / factor 5. Room temperature refers to 15-30°C, such as 23°C.
[0059] Based on the total weight of the second water-based ink composition, the content of styrene-propyl methacrylate can be about 1 wt% or higher, suitably about 2 wt% or higher, suitably about 3 wt% or higher, and / or about 10 wt% or lower, such as about 8 wt% or lower, suitably about 6 wt% or lower. Based on the total weight of the second water-based ink composition, the content of styrene-propyl methacrylate can be about 1 to 10 wt%, suitably 2 to 8 wt%, such as 3 to 6 wt%, or within any other combination of these endpoints.
[0060] In the second water-based ink composition, the solid weight ratio of the aforementioned hydroxyl-functionalized (meth)acrylic-styrene polymer to styrene-methyl methacrylate can be 10:1 to 2:1. For example, the solid weight ratio of the aforementioned hydroxyl-functionalized (meth)acrylic-styrene polymer to styrene-methyl methacrylate can be 10:1 or lower, 9:1 or lower, 8:1 or lower, 7:1 or lower, or 6:1 or lower, and / or 2:1 or higher, 3:1 or higher, 4:1 or higher, or 5:1 or higher, such as 8:1 to 2:1, 6:1 to 2:1, or any other combination of the aforementioned end values. For example, the solid weight ratio of the aforementioned hydroxyl-functionalized (meth)acrylic-styrene polymer to styrene-methyl methacrylate can be 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, or 3:1.
[0061] Suitablely, the hydroxyl- and / or carboxyl-containing resin in the second water-based ink composition includes a hydroxyl-functionalized (meth)acrylate-styrene polymer, a polyurethane, and styrene-methyl methacrylate, wherein the solid weight ratio of the hydroxyl-functionalized (meth)acrylate-styrene polymer to the polyurethane to the styrene-methyl methacrylate can be (2~4):(2~4):(1~2).
[0062] In the second water-based ink composition, the amino resin is a resin formed by the condensation polymerization of an amino-containing compound, such as urea, melamine, or benzomelamine, with formaldehyde and alcohols. The amino resin may include urea-formaldehyde resin, melamine-formaldehyde resin, and / or benzomelamine-formaldehyde resin. Suitably, the amino resin includes a methyl etherified amino resin. Suitably, the amino resin has a high imino content. The high imino content means that the imino content is at least 15 mol% based on the total number of reactive groups in the amino resin. The reactive groups are imino, methoxy, hydroxymethyl, and methyl ether. Suitably, the amino resin includes a methyl etherified amino resin with a high imino content, having at least 20 wt% imino groups based on the total number of reactive groups in the amino resin.
[0063] The amino resin may be in the form of a high-solids solvent-based amino resin, with a solids content of 85-95 wt%, which can be determined according to DIN EN ISO 3251 (2019). Suitably, the viscosity of the amino resin may be 5100-16000 cps at room temperature, which can be determined with reference to ISO 1652 using Brookfield RVT Spindle 1 / rpm 20 / factor 5. Room temperature refers to 15-30°C, such as 23°C.
[0064] Based on the total weight of the second water-based ink composition, the content of the amino resin can be about 5 wt% or higher, suitably about 6 wt% or higher, suitably about 7 wt% or higher, and / or about 15 wt% or lower, such as about 13 wt% or lower, suitably about 10 wt% or lower. Based on the total weight of the second water-based ink composition, the content of the amino resin can be about 5 to 15 wt%, suitably 6 to 13 wt%, such as 7 to 10 wt%, or within any other combination of these endpoints.
[0065] Suitably, in the second water-based ink composition, the solid weight ratio of the amino resin to the combination of the above-described resins (hydroxyl-functionalized (meth)acrylate-styrene polymer, polyurethane, and styrene-methyl methacrylate) can be 1:2 to 1:10. For example, the solid weight ratio of the amino resin to the combination of the above-described resins can be 1:2 or lower, 1:3 or lower, 1:4 or lower, or 1:5 or lower, and / or 1:10 or higher, 1:9 or higher, 1:8 or higher, 1:7 or higher, or 1:6 or higher, such as 1:2 to 1:9, 1:2 to 1:7, or any other combination using the above-described endpoints. For example, the solid weight ratio of the amino resin to the combination of the above-described resins can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, or 1:9.
[0066] In the second water-based ink composition, the aforementioned hydroxyl- and / or carboxyl-containing resin and amino resin constitute a binder. Suitably, the hydroxyl- and / or carboxyl-containing resin and amino resin may constitute at least 80 wt% of the total solids of the binder in the second water-based ink composition. For example, the hydroxyl- and / or carboxyl-containing resin and amino resin may constitute 85 wt% or higher, 90 wt% or higher, 95 wt% or higher, or even 100 wt% of the total solids of the binder in the second water-based ink composition.
[0067] The second water-based ink composition according to the invention may further include pigments and fillers. The pigments and fillers can provide color, effects, and / or functionality to the ink, and include coloring pigments and fillers (also known as extender pigments). Suitably, the pigments include inorganic pigments, such as titanium dioxide, carbon black, iron oxide, etc. Suitably, the fillers include fumed silica.
[0068] In the second water-based ink composition, the solid weight ratio of the binder to the pigment can be from 2:1 to 5:1. For example, in the second water-based ink, the solid weight ratio of the binder to the pigment can be 2:1 or higher, 3:1 or higher, or 3.5:1 or higher, and / or 5:1 or lower, or 4:1 or lower, such as 3:1 to 5:1, or any other combination of the above-mentioned end values. For example, in the second water-based ink composition, the solid weight ratio of the binder to the pigment can be 3:1, 3.5:1, or 4:1.
[0069] Based on the total weight of the second water-based ink composition, the content of pigments and fillers can be 10-25 wt%.
[0070] The second water-based ink composition according to the invention may further include a defoamer. The defoamer can inhibit bubble formation during the production process and facilitate the escape or collapse of already formed bubbles. Suitably, the defoamer may include a non-silicone organic defoamer (i.e., an organic defoamer that does not contain silicone). Based on the total weight of the second water-based ink composition, the content of the defoamer may be 0 to 2 wt%, for example, 0.1 to 1.5 wt%.
[0071] The second water-based ink composition according to the invention may further include a rheology modifier. The rheology modifier can effectively adjust viscosity, ensuring excellent workability and preventing edge thickening. Suitably, the rheology modifier may include inorganic bentonite thickeners and / or non-associated alkali-swellable thickeners. Based on the total weight of the second water-based ink composition, the content of the rheology modifier may be 0-2 wt%, for example, 0.1-1.5 wt%.
[0072] The second water-based ink composition according to the invention may further include a leveling agent. The leveling agent can improve flowability and processability to provide a coating with smoothness. Suitably, the leveling agent may include a silicone-based leveling agent. Based on the total weight of the second water-based ink composition, the content of the leveling agent may be 0-5 wt%, for example, 0.1-1.5 wt%.
[0073] The second water-based ink composition according to the present invention may further include a solvent. The solvent primarily comprises water, i.e., water accounts for at least 50 wt% of the solvent mass. The solvent may also include an organic solvent to aid in the compatibility of the components in the ink composition. Suitably, the organic solvent may include ether solvents. Based on the total weight of the second water-based ink composition, the water content may be 15-25 wt%. Based on the total weight of the second water-based ink composition, the organic solvent content may be 2-10 wt%.
[0074] The ink layer formed by the water-based ink system according to the present invention exhibits excellent substrate adhesion. Suitably, the ink layer formed by the water-based ink system according to the present invention exhibits excellent pull-out resistance, which can be determined in the manner described below.
[0075] The ink layer formed by the water-based ink system according to the present invention can have excellent optical density (OD). Suitablely, the ink layer formed by the water-based ink system according to the present invention has an optical density of OD > 5, which can be determined according to ASTM E 1079-05 standard.
[0076] The ink layer formed by the water-based ink system according to the present invention also has excellent chemical resistance, damp heat resistance and appearance aging resistance.
[0077] The water-based ink system according to the present invention can be prepared by the following method:
[0078] The preparation of the first water-based ink includes:
[0079] (1) Preparation of the first component of the first water-based ink composition: Add raw materials (except pigments) sequentially under mechanical stirring (800-900 rpm). After the addition is complete, continue stirring for at least 30 minutes until the fineness reaches 6.5 or higher (fineness is determined according to JJG 905-2010, which corresponds to 20 μm or lower). Adjust the pH to 8.0-9.0 using alkali, and then add the pigments sequentially. After all raw materials have been added, continue mechanical stirring for 15-20 minutes to ensure the fineness is 6.5 or higher (fineness is determined according to JJG 905-2010, which corresponds to 20 μm or lower). Filter using a 150-mesh filter to obtain the first component composition;
[0080] (2) The first component composition is mixed with a silane coupling agent to obtain a first water-based ink composition having an application viscosity of 15 to 35 seconds (measured using a Zahn 3# viscosity cup) at room temperature (15 to 30°C, such as 23°C).
[0081] The preparation of a second water-based ink includes:
[0082] Add the raw materials sequentially under mechanical stirring (800-900 rpm). After the materials are added, continue stirring for at least 30 minutes until the fineness reaches 6.5 or higher (fineness is determined according to JJG 905-2010, which corresponds to 20 μm or lower). Adjust the pH to 8.0-8.5 using alkali to ensure the fineness is 6.5 or higher (fineness is determined according to JJG 905-2010, which corresponds to 20 μm or lower). Filter using a 150-mesh filter to obtain a second water-based ink composition with an application viscosity of 15-35 seconds (measured using a Zahn 3# viscosity cup) at room temperature (15-30°C, such as 23°C).
[0083] The present invention also relates to a coated substrate, comprising a substrate and the aforementioned water-based ink system coated on at least a portion of the substrate. The substrate may include a glass substrate. The substrate may include a non-planar surface, such as a 3D surface. The substrate may include the surface of an electronic product. The substrate may be part of an electronic product.
[0084] The water-based ink system according to the present invention can be applied to a substrate by spraying. The spraying can be achieved using a commercially available spray gun. Alternatively, the water-based ink system according to the present invention can also be applied to the substrate by printing.
[0085] The present invention also relates to the use of the above-mentioned water-based ink system for coating substrates.
[0086] The present invention also relates to a method for processing a glass substrate, comprising:
[0087] The above-described water-based ink system is applied to at least a portion of a substrate, wherein the first water-based ink composition is applied to the substrate prior to the second water-based ink composition.
[0088] As described above, the first water-based ink composition is a two-package composition, the first package comprising a binder and the second package comprising an adhesion promoter comprising a silane coupling agent, wherein the first package and the second package are mixed just before being applied to the substrate.
[0089] Example
[0090] The following embodiments further illustrate the invention, but should not be construed as limiting the invention to the details described in the embodiments. Unless otherwise stated, all parts and percentages in the following embodiments are by weight.
[0091] Examples 1-3:
[0092] The first and second water-based ink compositions of Examples 1-3 were prepared according to the components and weight ratios listed in Tables 1-2. Specifically, they included:
[0093] (1) Under mechanical stirring (800-900 rpm), add each component of the first water-based ink composition sequentially (except for the pigment and silane coupling agent). After the addition is complete, continue stirring for at least 30 minutes until the fineness reaches 6.5 or higher. Adjust the pH to 8.0-9.0 using alkali, and then add the pigment. After all components have been added, continue mechanical stirring for 15-20 minutes to ensure the fineness is above 6.5. Filter using a 150-mesh filter to obtain the first component composition of the first water-based ink composition. Mix the first component composition with the silane coupling agent (the weight ratio of the first component composition to the silane coupling agent is 100:5) to obtain the first water-based ink composition with an application viscosity of 15-35 seconds (measured using a Zahn 3# viscosity cup).
[0094] (2) Add each component of the second water-based ink composition sequentially under mechanical stirring (800-900 rpm). After the addition is complete, continue stirring for at least 30 minutes until the fineness reaches 6.5 or higher. Adjust the pH to 8.0-8.5 using alkali to ensure the fineness is above 6.5. Filter using a 150-mesh filter to obtain the second water-based ink composition with an application viscosity of 15-35 seconds (measured using a Zahn 3# viscosity cup).
[0095] Table 1. First water-based ink compositions of Examples 1-3
[0096]
[0097] 1 The polyurethane dispersion has a solid content of 35–45 wt%, a pH of 7–8.5, and a viscosity of 20–200 cps at room temperature. The solid polyurethane is an aliphatic polyurethane with a tensile strength of 600–800% and a tensile strength of 1–5 N / mm. 2 100% modulus;
[0098] 2 Siloxane defoamers;
[0099] 3 Organosilicon leveling agents;
[0100] 4 Ether solvents;
[0101] 5 Polyurethane thickener;
[0102] 6 Silane coupling agents include epoxy functional groups.
[0103] Table 2. Second water-based ink compositions of Examples 1-3
[0104]
[0105] 1 Hydroxyl-functionalized (meth)acrylic acid-styrene polymer emulsion, with a solid content of 40-45 wt%, a pH of 1.0-3.0, a viscosity of 20-50 cps at room temperature, and the (meth)acrylic acid-styrene polymer solid having a hydroxyl value of 60-150 mgKOH / g and an MFFT of 40-80℃;
[0106] 2 The polyurethane dispersion has a solid content of 30-35 wt%, a pH value of 7.0-9.0, a viscosity of 50-150 cps at room temperature, and the polyurethane solid has an acid value of 10-40 mgKOH / g and a Tg of 90-120℃.
[0107] 3 Styrene-acrylic methacrylate emulsion with a solid content of 49-51 wt%, a pH of 7.0-8.0, a viscosity of 700-1000 cps at room temperature, and a MFFT of 60-100℃ for solid styrene-acrylic methacrylate.
[0108] 4 Non-silicone organic defoamers;
[0109] 5 Ether solvents;
[0110] 6 The high-solids-content solvent-based amino resin has a solids content of 85-95 wt% and a viscosity of 5100-16000 cps at room temperature. The amino resin solids are methyl etherified amino resins with a high imino content having at least 20 mol% imino groups based on the total amount of reactive groups in the amino resin.
[0111] 7 Inorganic bentonite-based thickeners and / or non-associated alkali-swellable thickeners;
[0112] 8 amine;
[0113] 9 Organosilicon leveling agents;
[0114] 10 Including carbon black, titanium dioxide, etc.
[0115] Comparative Example 1:
[0116] Commercially available inks from TKK were used as a comparative example.
[0117] Performance testing
[0118] The first water-based ink compositions of Examples 1-3 obtained above were applied to 3D glass substrates by spraying and cured at 140-160°C for 8-10 minutes. Then, the second water-based ink compositions of Examples 1-3 obtained above were applied to the first water-based ink layer by spraying and cured at 140-160°C for 15-30 minutes. A commercially available spray gun was used for spraying, with the following parameters: pressure of 1-2 kg and nozzle diameter of 1.1 mm. The 3D glass substrate was a glass plate with upward-curving edges, as shown in the attached... Figure 1 As shown.
[0119] The comparative ink composition was applied to a 2D glass substrate by screen printing, with 2-4 ink layers stacked, and then cured at 100-150°C for 10-30 minutes.
[0120] The following performance tests were performed on the cured ink layer.
[0121] Pull-out resistance
[0122] Two glass substrates are bonded together with the ink layers facing each other using an adhesive. At a temperature of -60°C, a compressive force is applied to the substrates from the opposite side of the ink layer until the two bonded glass substrates separate under pressure.
[0123] The test result should show that the ink film does not peel off under pressure.
[0124] OD:
[0125] The OD value was measured using an x-rite 341C Transmission Density Meter Model S / N according to ASTM E 1079-05 standard. A higher OD value indicates higher optical density and lower transmittance. The target value is OD > 5.
[0126] Chemical resistance
[0127] Determined according to ISO 2812-4:2017 standard.
[0128] Moist heat resistance
[0129] Determined according to GB / T 1740-2007 standard.
[0130] Resistance to surface aging
[0131] Determined according to GB / T 1856-2009 / ISO 11341:2004 standard.
[0132] Adhesion
[0133] Determined according to ASTM D3359-2002 standard.
[0134] The experimental results are shown in the table below:
[0135]
[0136] Based on the above experimental results, it can be seen that Embodiments 1-3 of the present invention are applicable to coating 3D substrates by spraying. The resulting ink layer has excellent comprehensive performance, meets application requirements, and is comparable to the ink layer obtained by printing commercially available inks on 2D substrates.
[0137] Although specific aspects of the invention have been explained and described, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to cover all such changes and modifications that fall within the scope of the invention.
Claims
1. A sprayable water-based ink system comprising a first water-based ink composition and a second water-based ink composition, wherein the first water-based ink composition comprises a binder comprising a thermally activated resin, the thermally activated resin being activated at a temperature of at least 120°C, wherein the second water-based ink composition comprises a binder comprising a high-temperature crosslinking resin, the high-temperature crosslinking resin being crosslinkable at a temperature of at least 120°C.
2. The water-based ink system of claim 1, wherein the binder of the first water-based ink composition comprises at least 70 wt% of a thermally activated resin based on the total solid weight of the binder.
3. The water-based ink system as described in claim 1 or 2, wherein the thermally activated resin comprises aliphatic polyurethane.
4. The water-based ink system of claim 3, wherein the aliphatic polyurethane is in the form of an aqueous dispersion having a pH value not exceeding 8.5 and a viscosity not exceeding 220 cps.
5. The water-based ink system as described in claim 3 or 4, wherein the aliphatic polyurethane has a content of 1~5 N / mm. 2 100% modulus.
6. The water-based ink system according to any one of claims 3-5, wherein the aliphatic polyurethane has a tensile strength at break of 600-800%.
7. The water-based ink system according to any one of claims 1-6, wherein the first water-based ink composition further comprises inorganic pigments.
8. The water-based ink system of claim 7, wherein the solid weight ratio of the binder to the inorganic pigment in the first water-based ink composition is 5:2 to 5:
10.
9. The water-based ink system according to any one of claims 1-8, wherein the high-temperature crosslinking resin comprises hydroxyl and / or carboxyl resins and amino resins.
10. The water-based ink system of claim 9, wherein the hydroxyl- and / or carboxyl-containing resin comprises a hydroxyl-functionalized (meth)acrylic acid-styrene polymer.
11. The water-based ink system of claim 10, wherein the hydroxyl-functionalized (meth)acrylic acid-styrene polymer has a hydroxyl value of 60-150 mgKOH / g.
12. The water-based ink system of claim 10 or 11, wherein the hydroxyl-functionalized (meth)acrylic acid-styrene polymer has an MFFT of 40-80°C.
13. The water-based ink system according to any one of claims 9-12, wherein the hydroxyl- and / or carboxyl-containing resin further comprises polyurethane and / or styrene-propyl methacrylate, wherein the styrene-propyl methacrylate is different from the hydroxyl-functionalized (meth)acrylate-styrene polymer.
14. The water-based ink system of claim 13, wherein the polyurethane comprises a polyether polyurethane.
15. The water-based ink system of claim 13 or 14, wherein the polyurethane has an acid value of 10-40 mgKOH / g.
16. The water-based ink system according to any one of claims 13-15, wherein the polyurethane has a Tg of 90-120°C.
17. The water-based ink system according to any one of claims 13-16, wherein the solid weight ratio of the hydroxyl-functionalized (meth)acrylic acid-styrene polymer, polyurethane and styrene methacrylate is (2~4):(2~4):(1~2).
18. The water-based ink system according to any one of claims 9-17, wherein the amino resin comprises a methyl etherified amino resin having a high imino content, and the methyl etherified amino resin having a high imino content comprises at least 20 mol% imino groups based on the total weight of the reactive groups in the amino resin.
19. The water-based ink system according to any one of claims 1-18, wherein the first water-based ink composition further comprises 0.5-5 wt% silane coupling agent based on the total weight of the first ink composition.
20. The water-based ink system according to any one of claims 1-19, wherein the first water-based ink composition and / or the second water-based ink composition have shear-thinning properties.
21. The water-based ink system according to any one of claims 1-20, wherein the first water-based ink composition / second water-based ink composition is curable at 150°C for 30 minutes.
22. The water-based ink system according to any one of claims 1-21, wherein the coating formed by the first water-based ink composition has a film thickness of 30-40 μm, and the coating formed by the second water-based ink composition has a film thickness of 15-20 μm.
23. The water-based ink system according to any one of claims 1-22, wherein the first water-based ink composition and / or the second water-based ink composition is sprayable.
24. A coated substrate, comprising a substrate and an aqueous ink system as described in any one of claims 1-23 coated on at least a portion of the substrate.
25. The coated substrate of claim 24, wherein the substrate comprises a glass substrate.
26. The coated substrate as claimed in claim 24 or 25, wherein the substrate is non-planar.
27. The coated substrate as claimed in any one of claims 24-26, wherein the substrate comprises an electronic product surface.
28. A method for processing a glass substrate, comprising: The water-based ink system as described in any one of claims 1-23 is applied to at least a portion of a substrate, wherein the first water-based ink composition is applied to the substrate prior to the second water-based ink composition.
29. The method of claim 28, wherein the first water-based ink composition is a two-package composition, the first package comprising a binder and the second package comprising a silane coupling agent, wherein the first package and the second package are mixed just before application to a substrate.