Sprayable aqueous ink system

Abstract

Disclosed is a sprayable aqueous ink system comprising a first aqueous ink and a second aqueous ink wherein the vehicle of the first ink comprises a thermally activated resin that can be activated at a temperature of at least 120 DEG C and wherein the vehicle of the second ink comprises a high temperature crosslinked resin that can be activated at a temperature of at least 120 DEG C. The high temperature crosslinked resin may be crosslinked at a temperature of at least 120 DEG C. The invention further discloses a base material coated with the water-based ink system. Also disclosed is a method of treating a glass substrate comprising applying the above aqueous ink system on at least a portion of the substrate wherein the first aqueous ink is applied to the substrate prior to the second aqueous ink.

Description

Technical Field

[0001] The invention relates to the field of inks, and in particular to a sprayable water-based ink system. Background Art

[0002] Ink is usually applied to the surface of the object / substrate by printing. However, printing has limitations for non-planar surfaces, such as 3D surfaces. With the widespread application of 3D glass in the consumer electronics industry, it is necessary to develop an ink that can be sprayed on 3D glass substrates.

[0003] Moreover, as the country's requirements for environmental protection become increasingly stringent, the use of solvent-based inks is increasingly restricted, and the market demand for water-based inks continues to expand. Therefore, how to provide a water-based ink with excellent performance is also a hot topic in the current ink field. Summary of the invention

[0004] The inventors have conducted extensive research and developed a sprayable water-based ink system that has excellent comprehensive performance while meeting environmental protection requirements.

[0005] The present invention provides an aqueous ink system, comprising a first aqueous ink and a second aqueous ink, wherein the binder of the first ink comprises a heat-activated resin, which can be activated at a temperature of at least 120°C, wherein the binder of the second ink comprises a high-temperature cross-linking resin, which can be cross-linked at a temperature of at least 120°C.

[0006] The present invention also provides a coated substrate, comprising a substrate and the above-mentioned aqueous 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 aqueous ink system described above is applied to at least a portion of the substrate, wherein the first aqueous ink is applied to the substrate before the second aqueous ink. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The 3D glass substrate sprayed with the aqueous ink system of Examples 1-3 is shown.

[0010] Figure 2 The method of pull-out strength test is shown. DETAILED DESCRIPTION

[0011] In this application, unless expressly stated otherwise, the use of the singular includes the plural and the plural includes the singular. For example, although "a" resin is mentioned herein, one or more of the material may be used.

[0012] In this application, the terms "comprises", "includes" and "contains" are not intended to limit the invention to exclude any variations or additions. In addition, although the present invention has been described with terms such as "comprising", the coating compositions, preparation methods, etc. described in detail herein may also be described as "essentially consisting of" or "consisting of". In this case, "essentially consisting of" means that any additional ingredients will not have a substantial effect on the properties of the coating formed by the coating composition.

[0013] In this application, unless otherwise expressly stated, the use of "or" means "and / or", even though "and / or" may be expressly used in certain circumstances. In addition, it should be understood that any numerical range listed herein is intended to include all subranges contained therein. For example, a range of "1 to 10" is intended to include all subranges between the listed minimum value of 1 and the listed maximum value of 10 (including the end values), that is, all subranges having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0014] Except in the examples or otherwise explicitly stated, all numerical values ​​used in the specification and claims representing the quantity of ingredients, etc., should be considered to be subject to variation according to the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters listed in the following specification and claims are approximate values ​​and may vary according to the performance desired to be obtained by the present invention. At the very least, it is not intended to limit the application of the doctrine of equivalents to the scope of the claims. Each numerical parameter should at least be interpreted in terms of significant figures and ordinary rounding should be applied.

[0015] Although the numerical ranges and parameters setting forth the broad scope of the invention are approximate, the numerical values ​​set forth in the specific embodiments are recorded as accurately as possible. However, any numerical value inherently has certain errors, which are the inevitable result of the standard deviation obtained in its corresponding measurement method.

[0016] As described above, the present invention relates to an aqueous ink system, comprising a first aqueous ink and a second aqueous ink, wherein the binder of the first ink comprises a heat-activated resin, which can be activated at a temperature of at least 120°C, and wherein the binder of the second ink comprises a high-temperature cross-linking resin, which can be cross-linked at a temperature of at least 120°C.

[0017] As used herein, the "first aqueous ink" or "first ink" refers to a composition of the first aqueous ink that has not been dried and solidified; the "second aqueous ink" or "second ink" refers to a composition of the second aqueous ink that has not been dried.

[0018] The first aqueous ink according to the present invention is a double-package composition. The "double-package composition" means that the components in the ink are packaged separately and the two packages are mixed in an accurate proportion before use.

[0019] The second aqueous ink according to the present invention can be a double-package composition. Alternatively, the second aqueous ink according to the present invention can be a single-package composition. The "single-package composition" means that all the components in the ink are placed in one package, so it has the advantage of being easy to use.

[0020] The first aqueous ink according to the present invention may be a thermosetting composition. The second aqueous ink according to the present invention may be a thermosetting composition. The thermosetting composition irreversibly forms a coating film after curing, which does not melt after reheating and does not dissolve in a solvent. In this article, the term "curing" means that at least a portion of the components in the ink composition are polymerized and / or cross-linked, or dried to form a hardened coating film.

[0021] The first aqueous ink according to the present invention can be cured by heating. The second aqueous ink according to the present invention can be cured by heating. The first aqueous ink and the second aqueous ink according to the present invention can be cured at 140-150°C*20-35min, respectively. Suitably, the first aqueous ink / second aqueous ink according to the present invention can be fully cured within 150°C*30min. The "fully cured" means that the ink layer has a MEK double rub value of at least 50 times, such as a MEK double rub value of 70 times.

[0022] The ink layer formed by the first aqueous ink according to the present invention may have a dry film thickness of 30 to 40 μm. The ink layer formed by the second aqueous ink according to the present invention may have a dry film thickness of 15 to 20 μm. The "dry film thickness" refers to the thickness of the ink layer after it is completely cured.

[0023] The first aqueous ink according to the present invention may have a solid content of 20 to 35 wt %. The second aqueous ink according to the present invention may have a solid content of 20 to 35 wt %. In this context, the "solid content" refers to the ratio of the mass remaining after drying of the ink composition to the total mass of the original composition.

[0024] The first aqueous ink according to the present invention may have a shear thinning property. The second aqueous ink according to the present invention may have a shear thinning property. The shear thinning property means that the viscosity of the ink composition decreases with the increase of shear force, that is, the viscosity of the ink composition is high at low viscosity, and the viscosity of the ink composition is low at high viscosity.

[0025] The first aqueous ink according to the present invention may have a 3-cup viscosity of 15 to 40 seconds. The second aqueous ink according to the present invention may have a 3-cup viscosity of 15 to 40 seconds. The viscosity may be measured under the following conditions: after being dispersed in a disperser at 700-1000 rpm for 15-30 minutes to achieve full dispersion, the viscosity may be measured after dilution at room temperature (the mass ratio of the composition to water is 100:0-5).

[0026] The first aqueous ink and the second aqueous ink having the above-mentioned specific properties can be suitable for spraying and application, which is beneficial for coating non-planar surfaces such as 3D surfaces, thereby overcoming the problem of printing. The first aqueous ink and the second aqueous ink according to the present invention are sprayable. The viscosity of the sprayable first aqueous ink / second aqueous ink composition meets the viscosity of 15 to 40 seconds for coating 3 cups.

[0027] In this article, the term "aqueous" means that the solvent of the ink composition contains at least 50wt% of water. The aqueous ink system according to the present invention has a low VOC content. As used herein, the term "VOC (volatile organic compound)" refers to any organic compound having a boiling point less than or equal to 250°C (482°F) measured at a standard atmospheric pressure of 101.3kPa. Organic solvents are generally the main source of VOC. Suitably, the VOC content of the aqueous ink system according to the present invention is 150 to 170g / L. Suitably, the VOC content of the first aqueous ink according to the present invention is 70 to 80g / L. Suitably, the VOC content of the second aqueous ink according to the present invention is 80 to 90g / L. The VOC value is a VOC value obtained in a water-free manner, which can be obtained by detecting the content of each organic compound component in the coating by gas chromatography and then adding the content of each component.

[0028] Herein, the "binder" refers to components in the ink composition that can cross-link / polymerize with each other or dry to form a film, for example, a resin.

[0029] In this article, the "heat activated resin" refers to a resin that will produce a certain viscosity and fluidity when the temperature is higher than a certain critical value (near the glass transition temperature), which helps to provide substrate and interlayer adhesion.

[0030] In this article, the "high temperature cross-linking resin" refers to a resin that undergoes self-crosslinking or cross-linking with other components under high temperature conditions. High temperature cross-linking resins suitable for the second aqueous ink may include hydroxyl and / or carboxyl resins and amino resins.

[0031] The heat activated resin suitable for the first aqueous ink may include polyurethane. The polyurethane refers to a polymer whose repeating units include a carbamate functional group. The polyurethane may include a polymer of at least 50wt% of organic units, such as at least 70wt% of organic units, such as at least 90wt% of organic units connected by carbamate bonds. In this article, the organic unit includes one or more residues selected from the following: simple diols, such as butanediol, polyester diols, polyether diols, polycarbonate diols, etc.

[0032] Suitably, the polyurethane may include aliphatic polyurethane. The aliphatic polyurethane may be prepared by alcohol and aliphatic isocyanate. The aliphatic isocyanate includes one or more selected from the group consisting of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane-4,4′-diisocyanate (HMDI).

[0033] Suitably, the polyurethane may have a breaking elongation of 600 to 800%. For example, the polyurethane may have a breaking elongation of 650%, 700%, or 750%. The breaking elongation refers to the ratio of the elongated length after stretching to the length before stretching when the polyurethane is broken by an external force. Suitably, the polyurethane has a breaking elongation of 1 to 5 N / mm 2 For example, the polyurethane may have a 100% modulus of 2 N / mm 2 , 3N / mm 2 , or 4N / mm 2 The 100% modulus is the tensile strength when the elongation is 100%.

[0034] Suitably, the polyurethane may be in the form of a dispersion. The solid content of the polyurethane dispersion may be 35 to 45 wt%, which may be determined according to DIN EN ISO 3251. The "solid content" refers to the percentage of the mass remaining after evaporation to the mass of the original dispersion. Suitably, the pH value of the polyurethane dispersion may be no more than 8.5, such as 7 to 8.5, which may be determined with reference to DIN ISO 976. Suitably, the viscosity of the polyurethane dispersion at room temperature may be no more than 220 cps, such as 20 to 200 cps, and may be determined with reference to ISO 1652 and using Brookfield RVT Spindle 1 / rpm20 / factor 5. The room temperature refers to 15 to 30°C.

[0035] The polyurethane has a suitable elongation at break and a 100% modulus, which enhances the flexibility of the ink. The characteristics of the polyurethane ensure that the ink can also maintain relatively flexible performance at a temperature of -60°C, thereby increasing the tensile strength that the ink can withstand. In addition, the polyurethane has good film-forming properties and has a certain degree of self-crosslinking at high temperatures, so that the ink has relatively good mechanical properties (such as good initial adhesion) even without the addition of a crosslinking agent.

[0036] The heat-activatable resin may comprise at least 75 wt%, suitably at least 80 wt%, such as 85 wt%, for example 90 wt%, such as 95 wt%, or even 100 wt% of the above polyurethane resin, based on the solid weight of the heat-activatable resin.

[0037] Based on the total weight of the first aqueous ink, the polyurethane can be greater than about 10wt%, suitably at least about 15wt%, suitably at least about 20wt%, and / or at most about 35wt%, such as at most about 30wt%, suitably at most about 25wt%. Based on the total weight of the first aqueous ink, the polyurethane can be about 10-35wt%, suitably 15-30wt%, such as 20-25wt%, or in any other combination range using these end values.

[0038] The heat activated resin constitutes the vehicle of the first aqueous ink. Suitably, the heat activated resin can constitute at least 80wt% of the total solid weight of the vehicle of the first aqueous ink. For example, the heat activated resin solids can constitute 85wt%, 90wt%, 95wt%, or 100wt% of the total solid weight of the vehicle of the first aqueous ink.

[0039] The first aqueous ink according to the present invention may also include a pigment. The pigment may provide color, effect and / or function to the ink, including a coloring pigment and a filler (also known as a body pigment). Suitably, the pigment includes an inorganic pigment. Compared to organic pigments, inorganic pigments improve the UV resistance of the aqueous ink. Suitably, the inorganic pigment may include an inorganic metal oxide, such as carbon black, titanium dioxide, iron oxide red, etc. Suitably, the filler includes fumed silica.

[0040] In the first aqueous ink, the solid weight ratio of the binder to the inorganic pigment may be 5:2 to 5:10. For example, the solid weight ratio of the binder to the inorganic pigment may be 5:3, 5:4, 5:5, 5:6, 5:7, 5:8 or 5:9.

[0041] Based on the total weight of the first aqueous ink, the pigment and filler may contain 10 to 50 wt %.

[0042] The first aqueous ink according to the present 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, the adhesion promoter may be 1 to 6 wt%, such as 2 to 5 wt%.

[0043] The first aqueous ink according to the present invention may further include a defoamer. The defoamer can inhibit the formation of bubbles during the production process and help the generated bubbles to escape or burst. Suitably, the defoamer includes a silicone defoamer. Based on the total weight of the first aqueous ink, the defoamer can be 0 to 2 wt%, such as 0.1 to 1.5 wt%.

[0044] The first aqueous ink according to the present invention may further include a rheological additive. The rheological additive can effectively adjust the viscosity, ensure excellent workability and avoid fat edges. Suitably, the rheological additive includes a polyurethane thickener. Based on the total weight of the first aqueous ink, the rheological additive can be 0 to 2 wt%, such as 0.1 to 1.5 wt%.

[0045] The first aqueous ink according to the present invention may further include a leveling agent. The leveling agent may improve fluidity and processability to provide a coating with smoothness. Suitably, the leveling agent includes an organosilicon-based leveling agent. Based on the total weight of the first aqueous ink, the leveling agent may be 0 to 2 wt%, such as 0.1 to 1.5 wt%.

[0046] The first aqueous ink according to the present invention may also include a solvent. The solvent mainly includes water, that is, water accounts for at least 50wt% of the solvent mass. The solvent may also include an organic solvent to help the components in the ink composition to be compatible. Suitably, the organic solvent includes an ether solvent. Based on the gross weight of the first aqueous ink, the water may be 20-40wt%. Based on the gross weight of the first aqueous ink, the organic solvent may be 1-10wt%.

[0047] Suitably, the first aqueous ink according to the present invention may be a two-component composition comprising at least one component, wherein the first component comprises: 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 a filler such as silicon dioxide are packaged separately to avoid the reaction between the two to cause an increase in viscosity and / or the failure of the coupling agent.

[0048] The high temperature cross-linking resin for the second aqueous ink includes a hydroxyl and / or carboxyl resin and an amino resin. The hydroxyl and / or carboxyl resin may include a hydroxyl functionalized (meth) acrylic acid-styrene polymer. The hydroxyl functionalization means that the polymer contains active hydroxyl groups, which participate in the cross-linking reaction. The (meth) acrylic acid-styrene polymer refers to a polymer obtained by polymerization of a mixture of the following monomers: methacrylic acid monomers and / or acrylic acid monomers, and styrene monomers.

[0049] Suitably, the hydroxyl-functionalized (meth) acrylic acid-styrene polymer has a hydroxyl value of 60 to 150 mgKOH / g. For example, the hydroxyl-functionalized (meth) acrylic acid-styrene polymer has a hydroxyl value of 80 mgKOH / g, a hydroxyl value of 100 mgKOH / g, a hydroxyl value of 110 mgKOH / g, or a hydroxyl value of 130 mgKOH / g. The hydroxyl value refers to the number of milligrams of potassium hydroxide (KOH) equivalent to the hydroxyl groups in 1 gram of resin.

[0050] Suitably, the hydroxyl-functionalized (meth) acrylic acid-styrene polymer has a MFFT (minimum film forming temperature) of 40 to 80° C. For example, the hydroxyl-functionalized (meth) acrylic acid-styrene polymer has a MFFT of 50° C., a MFFT of 60° C., or a MFFT of 70° C. The MFFT can be measured according to the provisions of ASTM D 2354 standard using a MFFT-BAR minimum film forming temperature instrument (British RHOPOINT minimum film forming temperature tester MFFT-60 / MFFT-90).

[0051] Suitably, the hydroxyl-functionalized (meth)acrylic-styrene polymer may be in the form of an emulsion. The solid content of the hydroxyl-functionalized (meth)acrylic-styrene polymer emulsion may be 40 to 45 wt%, which may be determined according to DIN EN ISO 3251 standard. The "solid content" refers to the percentage of the mass remaining after evaporation to the mass of the original emulsion. Suitably, the pH value of the emulsion of the hydroxyl-functionalized (meth)acrylic-styrene polymer may not exceed 1.0 to 3.0, which may be determined with reference to DIN ISO 976. Suitably, the viscosity of the emulsion of the hydroxyl-functionalized (meth)acrylic-styrene polymer at room temperature is 20 to 50 cps, and may be determined with reference to ISO 1652 and using Brookfield RVT Spindle 1 / rpm 20 / factor 5. The room temperature refers to 15 to 30°C.

[0052] Based on the total weight of the second aqueous ink, the hydroxyl-functionalized (meth) acrylic acid-styrene polymer can be greater than about 5wt%, suitably at least about 8wt%, suitably at least about 10wt%, and / or up to about 20wt%, such as up to about 18wt%, suitably up to about 15wt%. Based on the total weight of the second aqueous ink, the hydroxyl-functionalized (meth) acrylic acid-styrene polymer can be about 5-20wt%, suitably 8-18wt%, such as 10-15wt%, or in any other combination range using these end values.

[0053] The hydroxyl and / or carboxyl-containing resin may also include polyurethane. The polyurethane may include polyether polyurethane. The polyether polyurethane refers to a polyurethane that can be prepared by polyisocyanate and polyether polyol. Suitably, the polyurethane may have an acid value of 10 to 40 mgKOH / g. For example, the polyurethane may have an acid value of 20 mgKOH / g, or an acid value of 25 mgKOH / g. The "acid value" refers to the number of milligrams of potassium hydroxide required to neutralize the free acid in 1 gram of resin.

[0054] Suitably, the polyurethane may have a Tg (glass transition temperature) of 90 to 120° C. For example, the polyurethane may have a Tg of 100° C., or a Tg of 110° C. The glass transition temperature is measured by dynamic thermomechanical analysis (DMA) using a TA Instruments Q800 instrument, with measurement parameters: frequency of 10 Hz, amplitude of 5 mm, temperature ramp of -100° C. to 250° C., and Tg is determined as the peak of the tan delta curve according to ASTM D7028.

[0055] Suitably, the polyurethane may be in the form of a dispersion. The solid content of the polyurethane dispersion may be 30 to 35 wt%, which may be determined according to DIN EN ISO 3251. The "solid content" refers to the percentage of the mass remaining after evaporation to the mass of the original dispersion. Suitably, the pH value of the polyurethane dispersion may be 7.0 to 9.0, which may be determined with reference to DIN ISO 976. Suitably, the viscosity of the polyurethane dispersion at room temperature is 50 to 150 cps, and may be determined with reference to ISO 1652 and using a Brookfield RVT Spindle 1 / rpm 20 / fac-tor 5. The room temperature refers to 15 to 30°C.

[0056] Based on the total weight of the second aqueous ink, the polyurethane can be greater than about 5wt%, suitably at least about 8wt%, suitably at least about 10wt%, and / or up to about 20wt%, such as up to about 18wt%, suitably up to about 15wt%. Based on the total weight of the second aqueous ink, the polyurethane can be about 5-20wt%, suitably 8-18wt%, such as 10-15wt%, or in any other combination range using these end values.

[0057] In the second aqueous ink, the solid weight ratio of the hydroxyl functionalized (meth) acrylic acid-styrene polymer to the polyurethane may be 1:1 to 1:2.5. For example, the solid weight ratio of the hydroxyl functionalized (meth) acrylic acid-styrene polymer to the polyurethane may 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.

[0058] The hydroxyl-containing and / or resin may also include phenylpropyl methacrylate, which can help pigment dispersion. The phenylpropyl methacrylate is different from the above-mentioned hydroxyl-functionalized (meth) acrylic-styrene polymer. The phenylpropyl methacrylate refers to a polymer copolymerized from methacrylic acid monomer and styrene monomer. Suitably, the phenylpropyl methacrylate may have a MFFT (minimum film forming temperature) of 60 to 100°C. For example, the phenylpropyl methacrylate has a MFFT of 70°C, a MFFT of 80°C, or a MFFT of 90°C. The MFFT may be measured using a MFFT-BAR minimum film forming temperature instrument (British RHOPOINT minimum film forming temperature tester MFFT-60 / MFFT-90) according to the provisions of ASTM D 2354 standard.

[0059] The styryl methacrylate can be in the form of an emulsion. The solid content of the styryl methacrylate emulsion can be 49-51wt%, which can be determined according to DINENISO3251 standard. The "solid content" refers to the percentage of the mass remaining after evaporation to the mass of the original emulsion. Suitably, the pH value of the styryl methacrylate emulsion can be 7.0-8.0, which can be determined with reference to DIN ISO 976. Suitably, the viscosity of the styryl methacrylate emulsion at room temperature is 700-1000cps, and can be determined with reference to ISO 1652 and using Brookfield RVT Spindle 1 / rpm 20 / factor 5.

[0060] Based on the total weight of the second aqueous ink, the phenylpropyl methacrylate can be greater than about 1wt%, suitably at least about 2wt%, suitably at least about 3wt%, and / or up to about 10wt%, such as up to about 8wt%, suitably up to about 6wt%. Based on the total weight of the second aqueous ink, the phenylpropyl methacrylate can be about 1-10wt%, suitably 2-8wt%, such as 3-6wt%, or in any other combination range using these end values.

[0061] In the second aqueous ink, the solid weight ratio of the hydroxyl functionalized (meth) acrylic acid-styrene polymer to phenylpropyl methacrylate may be 10: 1 to 2: 1. For example, the solid weight ratio of the hydroxyl functionalized (meth) acrylic acid-styrene polymer to phenylpropyl methacrylate may be 9: 1, 8: 1, 7: 1, 6: 1, 5: 1, 4: 1 or 3: 1.

[0062] Suitably, the hydroxyl and / or carboxyl resin in the second aqueous ink comprises a hydroxyl-functionalized (meth) acrylic acid-styrene polymer, a polyurethane and styrene methacrylate, and the solid weight ratio of the hydroxyl-functionalized (meth) acrylic acid-styrene polymer to the polyurethane and the styrene methacrylate can be 2-4:2-4:1-2.

[0063] In the second aqueous ink, the amino resin is a compound containing an amino group, such as urea, melamine or benzoguanamine, and a resin formed by polycondensation with formaldehyde and alcohols. The amino resin may include urea-formaldehyde resin, melamine-formaldehyde resin and / or benzoguanamine-formaldehyde resin. Suitably, the amino resin includes methyl-etherified amino resin. Suitably, the amino resin has a high imino content. The high imino content refers to an imino content of at least 15mol% based on the sum of reactive groups in the amino resin. The reactive group refers to imino, methoxy, methylol and methyl ether. Suitably, the amino resin includes a methyl-etherified amino resin with a high imino content, which has at least 20wt% of imino based on the sum of reactive groups in the amino resin.

[0064] The amino resin may be in the form of a high solid solvent-based amino resin, and its solid content may be 85-95 wt%, which may be determined according to DIN EN ISO 3251. Suitably, the viscosity of the amino resin may be 5100-16000 cps at room temperature, and may be determined with reference to ISO 1652 and using Brookfield RVT Spindle 1 / rpm 20 / factor 5.

[0065] Based on the total weight of the second aqueous ink, the amino resin can be greater than about 5wt%, suitably at least about 6wt%, suitably at least about 7wt%, and / or up to about 15wt%, such as up to about 13wt%, suitably up to about 10wt%. Based on the total weight of the second aqueous ink, the amino resin can be about 5-15wt%, suitably 6-13wt%, such as 7-10wt%, or in any other combination range using these end values.

[0066] Suitably, in the second aqueous ink, the solid weight ratio of the amino resin to the above resin (hydroxyl functionalized (meth) acrylic acid-styrene polymer, polyurethane and / or phenylpropyl methacrylate) can be 1:2 to 1:10. For example, the solid weight ratio of the amino resin to the above resin can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or 1:9.

[0067] In the second water color ink, above-mentioned hydroxyl-containing and / or carboxyl resin and amino resin constitute a binder. Suitably, described hydroxyl-containing and / or carboxyl resin and amino resin can constitute at least 80wt% of the total solid weight of the binder of the second water color ink. For example, described hydroxyl-containing and / or carboxyl resin and amino resin can constitute 85wt%, 90wt%, 95wt%, or 100wt% of the total solid weight of the binder of the second water color ink.

[0068] The second aqueous ink according to the present invention may further include a pigment filler. The pigment filler may provide color, effect and / or function to the ink, and includes a coloring pigment and a filler (also known as a body pigment). Suitably, the pigment includes an inorganic pigment, such as titanium white pigment, carbon black pigment, iron red, etc. Suitably, the filler includes fumed silica.

[0069] In the second aqueous ink, the solid weight ratio of the binder to the pigment may be 2: 1 to 5: 1. For example, in the second aqueous ink, the solid weight ratio of the binder to the pigment may be 3: 1, 3.5: 1 or 4: 1.

[0070] Based on the total weight of the second aqueous ink, the pigment and filler may contain 10 to 25 wt %.

[0071] The second aqueous ink according to the present invention may further include a defoamer. The defoamer can inhibit the formation of bubbles during the production process and help the generated bubbles to escape or burst. Suitably, the defoamer includes a non-silicon organic defoamer (i.e., an organic defoamer that does not contain silicon). Based on the total weight of the second aqueous ink, the defoamer can be 0 to 2 wt%, such as 0.1 to 1.5 wt%.

[0072] The second aqueous ink according to the present invention may further include a rheological additive. The rheological additive can effectively adjust the viscosity, ensure excellent workability and avoid fat edges. Suitably, the rheological additive includes an inorganic bentonite thickener and / or a non-associative alkali swelling thickener. Based on the total weight of the second aqueous ink, the rheological additive can be 0 to 2 wt%, for example 0.1 to 1.5 wt%.

[0073] The second aqueous ink according to the present invention may further include a leveling agent. The leveling agent may improve fluidity and processability to provide a coating with smoothness. Suitably, the leveling agent includes an organosilicon-based leveling agent. Based on the total weight of the second aqueous ink, the leveling agent may be 0 to 5 wt%, such as 0.1 to 1.5 wt%.

[0074] The second aqueous ink according to the present invention may further include a solvent. The solvent mainly includes water, that is, water accounts for at least 50wt% of the solvent mass. The solvent may also include an organic solvent to help the components in the ink composition to be compatible. Suitably, the organic solvent includes an ether solvent. Based on the total weight of the second aqueous ink, the water may be 15 to 25wt%. Based on the total weight of the second aqueous ink, the organic solvent may be 2 to 10%.

[0075] The ink layer formed by the aqueous ink system according to the present invention has excellent substrate adhesion. Suitably, the ink layer formed by the aqueous ink system according to the present invention has a strength of >10 N / mm 2 The pull-out strength can be determined in the manner described below.

[0076] The ink layer formed by the aqueous ink system according to the present invention may have excellent optical density. Suitably, the ink layer formed by the aqueous 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.

[0077] The ink layer formed by the aqueous ink system according to the present invention also has excellent chemical resistance, moisture and heat resistance, and appearance aging resistance.

[0078] The aqueous ink system according to the present invention can be prepared by the following method:

[0079] A first aqueous ink is prepared, comprising:

[0080] (1) Prepare the first component of the first water-based ink: add the raw materials (except the pigment) in sequence under mechanical stirring (800-900rpm), and continue stirring for at least thirty minutes after the addition is completed until the fineness reaches above 6.5. Use alkali to adjust the pH to 8.0-9.0, and then add the pigment in sequence. After all the raw materials are added, continue mechanical stirring for 15-20 minutes to ensure that the fineness is above 6.5, and filter with a 150-mesh filter to obtain the first component composition;

[0081] (2) The first component composition is mixed with a silane coupling agent to obtain a first aqueous ink composition having a viscosity of 15 to 40 seconds after coating 3 cups.

[0082] A second aqueous ink is prepared, comprising:

[0083] The raw materials were added in sequence under mechanical stirring (800-900 rpm), and stirring was continued for at least thirty minutes after the addition was completed until the fineness reached 6.5 or more. The pH was adjusted to 8.0-8.5 with alkali to ensure that the fineness was above 6.5, and filtered with a 150-mesh filter to obtain a first aqueous ink composition with a viscosity of 15-40 seconds after coating 3 cups.

[0084] The present invention also relates to a coated substrate, comprising a substrate and the above-mentioned aqueous 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 an electronic product surface. The substrate may be a part of an electronic product.

[0085] The aqueous ink system according to the present invention can be applied to the substrate by spraying. The spraying can be achieved by a commercially available spray gun. Alternatively, the aqueous ink system according to the present invention can also be applied to the substrate by printing.

[0086] The present invention further relates to the use of the aqueous ink system for coating a substrate.

[0087] The present invention also relates to a method for treating a glass substrate, comprising:

[0088] The aqueous ink system described above is applied to at least a portion of the substrate, wherein the first aqueous ink is applied to the substrate before the second aqueous ink.

[0089] As described above, the first aqueous ink is a two-pack composition, the first pack comprising a binder, and the second pack comprising a silane coupling agent, wherein the first pack and the second pack are mixed just before being applied to a substrate.

[0090] Example

[0091] The following examples are provided to further illustrate the present invention but should not be construed as limiting the invention to the details described in the examples. Unless otherwise indicated, all parts and percentages in the following examples are by weight.

[0092] Embodiment 1-3:

[0093] The first aqueous ink composition and the second aqueous ink composition of Example 1-3 were prepared according to the components and weight ratios listed in Table 1-2. Specifically, they included:

[0094] (1) adding each component of the first aqueous ink composition (except the pigment and the silane coupling agent) in sequence under mechanical stirring (800-900 rpm), and continuing stirring for at least 30 minutes after the addition is completed until the fineness reaches 6.5 or above; adjusting the pH to 8.0-9.0 with alkali, and then adding the pigment, and continuing mechanical stirring for 15-20 minutes after all the components are added to ensure that the fineness is above 6.5, and filtering with a 150-mesh filter to obtain a first component composition of the first aqueous ink composition; mixing 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 a first aqueous ink composition with a viscosity of 15 to 30 seconds after applying 3 cups.

[0095] (2) Add the components of the second aqueous ink composition in sequence under mechanical stirring (800-900 rpm), and continue stirring for at least 30 minutes after the addition is completed until the fineness reaches 6.5 or above; use alkali to adjust the pH to 8.0-8.5 to ensure that the fineness is above 6.5, and filter with a 150-mesh filter to obtain a second aqueous ink composition with a viscosity of 20-40 seconds after coating 3 cups.

[0096] Table 1. First aqueous ink composition of Examples 1-3

[0097]

[0098]

[0099] 1 Polyurethane dispersion, solid content of 35-45wt%, pH value of 7-8.5, viscosity of 20-200cps at room temperature, polyurethane solid is fat type polyurethane, which has 600-800% elongation at break and 1-5N / mm 2 100% modulus of

[0100] 2 Silicone defoamers;

[0101] 3 Silicone leveling agent;

[0102] 4 Ether solvents;

[0103] 5 Polyurethane thickener;

[0104] 6 The silane coupling agent includes an epoxy functional group.

[0105] Table 2. Second aqueous ink composition of Examples 1-3

[0106]

[0107] 1 A hydroxyl-functionalized (meth)acrylic acid-styrene polymer emulsion having a solid content of 40 to 45 wt %, a pH value of 1.0 to 3.0, a viscosity of 20 to 50 cps at room temperature, and a (meth)acrylic acid-styrene polymer solid having a hydroxyl value of 60 to 150 mgKOH / g and a MFFT of 40 to 80° C.;

[0108] 2 A polyurethane dispersion having a solid content of 30 to 35 wt %, a pH of 7.0 to 9.0, a viscosity of 50 to 150 cps at room temperature, and a polyurethane solid having an acid value of 10 to 40 mgKOH / g and a Tg of 90 to 120° C.;

[0109] 3 A styryl methacrylate emulsion having a solid content of 49-51 wt %, a pH value of 7.0-8.0, a viscosity of 700-1000 cps at room temperature, and a styryl methacrylate solid having a MFFT of 60-100° C.;

[0110] 4 Non-silicone organic defoamer;

[0111] 5 Ether solvents;

[0112] 6 High solid solvent-based amino resin, solid content of 85-95wt%, viscosity of 5100-16000cps at room temperature, amino resin solid is methyl etherified amino resin with high imino content:

[0113] 7 Inorganic bentonite thickeners and / or non-associative alkali swelling thickeners:

[0114] 8 amine:

[0115] 9 Silicone leveling agent;

[0116] 10 Including carbon black, titanium dioxide, etc.

[0117] Comparative Example 1:

[0118] A commercially available ink product from TKK Corporation was used as a comparative example.

[0119] Performance Testing

[0120] The first aqueous ink composition of Examples 1-3 obtained as above was respectively applied to the 3D glass substrate by spraying, and cured at 140-160°C for 8-10 minutes; then, the second aqueous ink composition of Examples 1-3 obtained as above was applied to the first aqueous ink layer by spraying, and cured at 140-160°C for 15-30 minutes. A commercially available spray gun was used for spraying, and the spraying parameters were: pressure of 1-2kg; and spray gun caliber of 1.1mm. The 3D glass substrate is a glass plate with an upwardly tilted edge, as shown in the attached Figure 1 shown.

[0121] The ink composition of the comparative example 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.

[0122] The following performance tests were performed on the cured ink layer.

[0123] 1-Pull-out strength

[0124] Two glass substrates are bonded together with the ink layers facing each other by adhesive, and placed in a mold and squeezed at -90℃ until the two glass substrates are separated under pressure. Figure 2 shown.

[0125] The test result represents the value obtained by dividing the maximum force by the paint film peeling area under the maximum force. The test result needs to be greater than 1.5 to meet the pull-out strength test requirements.

[0126] 2-OD:

[0127] According to ASTM E 1079-05 standard, it is measured using x-rite 341C Transmission Densi-tometer Model S / N. The larger the OD value, the higher the optical density and the worse the transmittance.

[0128] The goal is OD>5.

[0129] 3- Chemical resistance

[0130] Determined according to ISO 2812-4:2017 standard.

[0131] 4-Resistant to moisture and heat

[0132] Determined according to GB / T 1740-2007 standard.

[0133] 5-Resistant to appearance aging

[0134] Determined according to GB / T 1856-2009 / ISO 11341:2004 standard.

[0135] The experimental results are shown in the following table:

[0136]

[0137] Referring to the above experimental results, it can be seen that Examples 1-3 according to the present invention can be suitable for coating 3D substrates by spraying, and the formed ink layer has excellent comprehensive performance, meets application requirements, and can be comparable to the ink layer obtained by printing commercially available inks on 2D substrates.

[0138] While particular aspects of the invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. It is therefore intended that the appended claims cover all such changes and modifications as fall within the scope of the invention.

Claims

1. An aqueous ink system, comprising a first aqueous ink and a second aqueous ink, wherein the binder of the first ink comprises a heat-activated resin, which can be activated at a temperature of at least 120° C., wherein the binder of the second ink comprises a high-temperature cross-linking resin, which can be cross-linked at a temperature of at least 120° C.

2. The aqueous ink system of claim 1, wherein the vehicle of the first ink comprises at least 70 wt% of the heat activated resin based on the total solid weight of the vehicle.

3. A water-based ink system as claimed in claim 1 or 2, wherein the heat-activated resin comprises aliphatic polyurethane.

4. The aqueous ink system of claim 3, wherein the aliphatic polyurethane is in the form of an aqueous dispersion having a pH value of no more than 8.5 and a viscosity of no more than 220 cps.

5. The aqueous ink system according to claim 3 or 4, wherein the fatty polyurethane has a viscosity of 1 to 5 N / mm 2 100% modulus.

6. The aqueous ink system according to any one of claims 3 to 5, wherein the aliphatic polyurethane has a breaking elongation of 600 to 800%.

7. The aqueous ink system as claimed in any one of claims 1 to 6, wherein the first aqueous ink further comprises an inorganic pigment.

8. The aqueous ink system as claimed in claim 7, wherein the solid weight ratio of the binder to the inorganic pigment in the first ink is 5:2 to 5:

10.

9. The aqueous ink system according to any one of claims 1 to 8, wherein the high temperature cross-linking resin comprises a hydroxyl and / or carboxyl resin and an amino resin.

10. The aqueous ink system of claim 9, wherein the hydroxyl- and / or carboxyl-containing resin comprises a hydroxyl-functionalized (meth) acrylic-styrene polymer.

11. The aqueous ink system of claim 10, wherein the hydroxyl-functionalized (meth)acrylic-styrene polymer has a hydroxyl value of 60 to 150 mgKOH / g.

12. The aqueous ink system according to claim 10 or 11, wherein the hydroxyl-functionalized (meth)acrylic-styrene polymer has a MFFT of 40 to 80°C.

13. A water-based ink system as described in any one of claims 9 to 12, wherein the hydroxyl- and / or carboxyl-containing resin further comprises polyurethane, and / or phenylpropyl methacrylate, wherein the phenylpropyl methacrylate is different from a hydroxyl-functionalized (meth) acrylic acid-styrene polymer.

14. The aqueous ink system of claim 13, wherein the polyurethane comprises polyether polyurethane.

15. The aqueous ink system according to claim 13 or 14, wherein the polyurethane has an acid value of 10 to 40 mgKOH / g.

16. The aqueous ink system according to any one of claims 13 to 15, wherein the polyurethane has a Tg of 90 to 120°C.

17. The aqueous ink system according to any one of claims 13 to 16, wherein the solid weight ratio of the hydroxyl functionalized (meth) acrylic-styrene polymer, polyurethane and styrene methacrylate is 2-4:2-4:1-2.

18. The aqueous ink system of any one of claims 9 to 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 % of imino groups based on the total weight of reactive groups in the amino resin.

19. The aqueous ink system according to any one of claims 1 to 18, wherein the first ink further comprises 0.5 to 5 wt% of a silane coupling agent based on the total weight of the first ink.

20. The aqueous ink system according to any one of claims 1 to 19, wherein the first ink and / or the second ink has shear thinning properties.

21. The aqueous ink system according to any one of claims 1 to 20, wherein the first ink / second ink is cured at 150°C within 30 minutes.

22. The aqueous ink system according to any one of claims 1 to 21, wherein the coating formed by the first ink has a film thickness of 30 to 40 μm, and the coating formed by the second ink has a film thickness of 15 to 20 μm.

23. The aqueous ink system of any one of claims 1 to 22, wherein the first aqueous ink and / or the second aqueous ink are sprayable.

24. A coated substrate comprising a substrate and the aqueous ink system according to any one of claims 1 to 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 of claim 24 or 25, wherein the substrate is non-planar.

27. The coated substrate of any one of claims 24-26, wherein the substrate comprises an electronic product surface.

28. A method for treating a glass substrate, comprising: Applying the aqueous ink system of any one of claims 1 to 23 to at least a portion of the substrate, wherein the first aqueous ink is applied to the substrate before the second aqueous ink.

29. The method of claim 28, wherein the first aqueous ink is a two-pack composition, a first pack comprising a binder and a second pack comprising a silane coupling agent, wherein the first pack and the second pack are mixed just before application to a substrate.

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