High-color-content low-viscosity water-based black paste as well as preparation method and application thereof

Abstract

The invention relates to the technical field of color paste, in particular to high-color-content low-viscosity water-based black paste and a preparation method and application thereof.The high-color-content low-viscosity water-based black paste is prepared from, by weight, 30-40 parts of water-based acrylic resin, 1-5 parts of dispersing agent, 0.1-2 parts of wetting agent, 0.01-0.2 part of defoaming agent, 43-50 parts of pigment carbon black, 0.3-1 part of preservative and 10-30 parts of deionized water; the BET specific surface area of the pigment carbon black is 20-50 m < 2 > / g, the primary particle size is 30-100 nm, and the oil absorption is 30-55 g / 100 g; through screening and proportioning optimization of specific raw materials, excellent dispersion stability and pure blackness and gloss under high pigment content are realized, and the pigment has wide compatibility and application adaptability.

Description

Technical Field

[0001] This invention relates to the field of pigment technology, specifically to a high-color-content, low-viscosity water-based black pigment, its preparation method, and its application. Background Technology

[0002] With increasingly stringent environmental regulations, water-based coatings and inks are widely used due to their low volatile organic compound (VOC) emissions. Pigment paste, as a key component, has crucial performance. Traditional high-pigment-content, low-viscosity water-based black pastes or commercially available products often suffer from the following problems: difficulty in increasing pigment content, leading to high viscosity, poor flowability, and poor storage stability (such as coarsening, sedimentation, and thickening); difficulty in carbon black dispersion, resulting in insufficient blackness, tinting strength, or incorrect hue (yellowish / bluish); poor compatibility with various resin systems; and potential oxidation problems in certain applications (such as hot stamping). Chinese patent (authorization announcement number CN115746627B) discloses an ultra-high solids water-based nano black paste and its preparation method. It mainly achieves high pigment filling through optimized pigment paste formulation, thereby ensuring the blackness of the pigment paste. However, the excellent dispersion stability and subsequent application effects under high pigment content need further improvement.

[0003] Therefore, developing a high-pigment-content, low-viscosity water-based black paste with high pigment content, stable dispersion, pure blackness, good gloss, wide applicability, and stable processing has significant market value. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a high-pigment-content, low-viscosity water-based black paste. Through the screening and optimization of specific raw materials, it achieves excellent dispersion stability, pure blackness, and gloss under high pigment content, and possesses broad compatibility and application adaptability.

[0005] This invention provides a high-color, low-viscosity water-based black paste, comprising, by weight: 30-40 parts water-based acrylic resin, 1-5 parts dispersant, 0.1-2 parts wetting agent, 0.01-0.2 parts defoamer, 43-50 parts pigment carbon black, 0.3-1 part preservative, and 10-30 parts deionized water; wherein the pigment carbon black has a BET specific surface area of ​​20-50 m². 2 / g, with a native particle size of 30-100nm and an oil absorption capacity of 30-55g / 100g.

[0006] This invention utilizes a BET specific surface area of ​​20-50 m² 2 / g, with a native particle size of 30-100nm and an oil absorption of 30-55g / 100g, pigment carbon black (such as Orilon SB250), combined with water-based acrylic resin and other raw materials, has a pigment content as high as 43-50%, far exceeding ordinary color pastes. The color paste has a pure blackness (blue hue base color, not yellowish), strong tinting strength, high gloss, and excellent light-net transfer properties. At the same time, the product maintains good low viscosity and fluidity, making it easy to mix and use later.

[0007] In one embodiment, the high-color-content, low-viscosity waterborne black paste comprises, by weight, the following components: 35-38 parts waterborne acrylic resin, 2-3 parts dispersant, 0.5-0.8 parts wetting agent, 0.1-0.12 parts defoamer, 45-48 parts pigment carbon black, 0.5-0.6 parts preservative, and 11.9-21.9 parts deionized water.

[0008] In one embodiment, the pigment carbon black has a BET specific surface area of ​​35-45 m². 2 / g, with a native particle size of 50-60nm and an oil absorption capacity of 45-50g / 100g.

[0009] In one embodiment, the pigment carbon black has a BET specific surface area of ​​40 m². 2 / g, native particle size is 56nm, oil absorption is 48g / 100g, model is Eulilong SB250.

[0010] In one embodiment, the waterborne acrylic resin has a Brookfield viscosity of 3000-12000 mPa·s at 25°C and an acid value of 200-210 mgKOH / g.

[0011] In one embodiment, the waterborne acrylic resin has a Brookfield viscosity of 6000-9000 mPa·s at 25°C, an acid value of 205 mgKOH / g, and is designated as model 8096, originating from Guangzhou Jiexun Technology Development Co., Ltd.

[0012] In one embodiment, the dispersant comprises an acrylate copolymer dispersant.

[0013] In one embodiment, the acrylate copolymer dispersant is designated BYK-2012.

[0014] In one embodiment, the wetting agent comprises an acetylenic diol surfactant.

[0015] In one embodiment, the acetylenol surfactant is designated Surfynol 465.

[0016] In one embodiment, the defoamer is a polyether siloxane defoamer.

[0017] In one embodiment, the polyether siloxane defoamer is designated Foamex 8420.

[0018] Furthermore, this invention solves the stability problem of low viscosity, high pigment content system by using waterborne acrylic resin with a Brookfield viscosity of 3000-12000 mPa·s at 25°C, combined with the introduction of acrylate copolymer dispersants and acetylenol surfactants. The prepared color paste does not exhibit stratification, precipitation, coarsening, or thickening after long-term storage, while also improving grinding efficiency. The product has bright and full color and good gloss.

[0019] In one embodiment, the preservative comprises nano-silver.

[0020] In one embodiment, the nanosilver has a particle size of 10-30 nm.

[0021] In one embodiment, the nanosilver has a particle size of 20 nm, is an AgP01 nanosilver solution, and is manufactured by Nanjing Dongna Biotechnology Co., Ltd.

[0022] The high-color, low-viscosity water-based black paste provided by this invention has no detected sulfides, and when combined with nano-silver corrosion inhibitor, the coating or ink layer prepared by it performs excellently in hot stamping process without oxidation, thus expanding its application in high-end decoration fields.

[0023] The acrylic color paste of this invention is highly compatible with various water-based resins (such as acrylic acid and polyurethane) and is not prone to flocculation or gelation. It is suitable for various processes such as spraying, roller coating, and brushing, and is widely used in water-based coatings (architectural coatings, industrial coatings, wood coatings, etc.), inks, leather finishing, textile printing, and paper coloring. The high-color-content, low-viscosity water-based black paste produced by this invention not only has high color content and low viscosity, but also significantly reduces the impact on hot stamping oxidation, thereby eliminating more hot stamping risks and ensuring the aesthetic appeal of finished products.

[0024] Another aspect of the present invention provides a method for preparing high-color-content, low-viscosity water-based black paste, comprising the following steps: Add 70-80% of the total weight of water-based acrylic resin, dispersant, wetting agent, defoamer, and deionized water to a container and disperse for 10-15 minutes at 800-1200 r / min. Add pigment carbon black and continue dispersing for 30-40 minutes to obtain the dispersed material; Grind the dispersed material 4-5 times using a sand mill until the fineness is ≤10μm. Add the remaining deionized water and preservative, and disperse for 5-10 minutes.

[0025] Based on the raw materials in the system, by optimizing the preparation process, especially by grinding the dispersed material 4-5 times to a fineness of ≤10μm, the dispersion system can be made completely stable, ensuring the long-term stability of the product. However, if the number of grinding passes is less, although a fineness of ≤10μm can be achieved in the short term, the cumulative energy input is insufficient to make the dispersion system completely stable. After storage, the particles that are not fully coated will re-aggregate, resulting in coarsening and thickening.

[0026] The third aspect of this invention provides an application of a high-color, low-viscosity water-based black paste, which is used in the preparation of water-based coatings, water-based inks, or adhesives.

[0027] Beneficial effects 1. This invention provides a high-pigment-content, low-viscosity water-based black paste. Through the screening and optimization of specific raw materials, it achieves excellent dispersion stability, pure blackness and gloss under high pigment content, and has broad compatibility and application adaptability.

[0028] 2. This invention utilizes a BET specific surface area of ​​20-50 m². 2 / g, with a native particle size of 30-100nm and an oil absorption of 30-55g / 100g, pigment carbon black (such as Orilon SB250), combined with water-based acrylic resin and other raw materials, has a pigment content as high as 43-50%, far exceeding ordinary color pastes. The color paste has a pure blackness (blue hue base color, not yellowish), strong tinting strength, high gloss, and excellent light-net transfer properties. At the same time, the product maintains good low viscosity and fluidity, making it easy to mix and use later.

[0029] 3. This invention solves the stability problem of low viscosity, high pigment content system by using water-based acrylic resin with a Brookfield viscosity of 3000-12000 mPa·s at 25℃ and an acid value of 200-210 mgKOH / g, combined with the introduction of acrylate copolymer dispersants and acetylenic diol surfactants. The prepared color paste does not show stratification, precipitation, coarsening, or thickening after long-term storage. At the same time, it improves grinding efficiency, and the product has bright and full color and good gloss.

[0030] 4. The high-color, low-viscosity water-based black paste provided by this invention has no detected sulfides, and when combined with nano-silver corrosion inhibitor, the coating or ink layer prepared by it performs excellently in hot stamping process without oxidation, thus expanding its application in high-end decoration field.

[0031] 5. The acrylic color paste of this invention is well compatible with various water-based resins (such as acrylic acid, polyurethane, etc.) and is not prone to flocculation or gelation. It is suitable for various processes such as spraying, roller coating, and brushing, and is widely used in water-based coatings (architectural coatings, industrial coatings, wood coatings, etc.), inks, leather finishing, textile printing, paper coloring and other fields. Detailed Implementation

[0032] Examples 1-4, Comparative Examples 1-2 Examples 1-4 and Comparative Examples 1-2 of the present invention provide a high-color, low-viscosity water-based black paste, the formulation of which is shown in Table 1 by weight.

[0033] Table 1

[0034] Examples 1-4 and Comparative Examples 1-2 of the present invention provide a method for preparing high-color, low-viscosity water-based black paste, comprising the following steps: Add 74% of the total weight of water-based acrylic resin, dispersant, wetting agent, defoamer, and deionized water to a container and disperse at 1000 r / min for 10 min. Add pigment carbon black and continue dispersing for 30 minutes to obtain a dispersed material; The dispersed material was ground four times using a sand mill until the fineness was ≤10μm. The remaining deionized water and preservative were added and dispersed for 5 minutes.

[0035] Comparative Example 3 Comparative Example 3 of the present invention is a commercially available high-color, low-viscosity water-based black paste, model DIC FlexiverseBlack (pigment content 40wt%, pH value 8.4-9.2).

[0036] Comparative Example 4 Comparative Example 4 of this invention is a commercially available high-pigment, low-viscosity water-based black paste, model number Kedi BK17-SP (pigment content 40wt%, pH 7.5-9.0, belonging to resin-free black paste).

[0037] Comparative Example 5 Comparative Example 5 of the present invention is a commercially available high-pigment, low-viscosity water-based black paste, model number Kedi BK9007 (pigment content of 40wt%, pH value of 7.5-9.0).

[0038] Comparative Example 6 Comparative Example 6 of the present invention provides a high-color-content, low-viscosity water-based black paste and its preparation method. The specific implementation method is the same as that of Example 1, except that the amount of water-based acrylic resin is 0 and the amount of deionized water is replaced with 55.6 parts by weight.

[0039] Comparative Example 7 Comparative Example 7 of the present invention provides a high-color, low-viscosity water-based black paste and its preparation method. The specific implementation method is the same as that of Example 1, except that the 4-times grinding with a sand mill is replaced by 3-times grinding with a sand mill.

[0040] Performance testing The following tests were performed on the products provided in each embodiment and comparative example, and the test results are shown in Table 2.

[0041] 1. Fineness: Tested in accordance with GB / T 1724-2019 Determination of grinding fineness of paints, varnishes and printing inks.

[0042] 2. Gloss, tested according to GB / T 13217.2-2009 Test method for gloss of liquid ink.

[0043] 3. Viscosity, tested according to GB / T 13217.4-2020 Ink Viscosity Test Method.

[0044] 4. Tinting strength, tested according to GB / T 13217.1-2020 Test Method for Color and Tinting Strength of Inks.

[0045] 5. pH value, measured using a pH meter.

[0046] 6. Sulfur content test shall be conducted in accordance with GB / T 37907-2019 Determination of Sulfides and Cyanides in Reclaimed Water by Ion Chromatography.

[0047] 7. Oxidation test for hot stamping, in accordance with BB / T 0031-2023 Electroplated Aluminum Hot Stamping Foil.

[0048] Table 2

[0049] Analysis of the data in Table 2 shows that Examples 1-4 have better overall performance than Comparative Examples 1-7.

Claims

1. A high color, low viscosity, aqueous black paste, characterized in that, By weight parts, including the following components: water-based acrylic resin 30-40 parts, dispersant 1-5 parts, wetting agent 0.1-2 parts, defoamer 0.01-0.2 parts, pigment carbon black 43-50 parts, preservative 0.3-1 part, deionized water 10-30 parts; the BET specific surface area of the pigment carbon black is 20-50 m 2 / g, the primary particle size is 30-100 nm, and the oil absorption is 30-55 g / 100 g.

2. The high color low viscosity waterborne black of claim 1, wherein, By weight, the high-color-content, low-viscosity water-based black paste comprises the following components: 35-38 parts water-based acrylic resin, 2-3 parts dispersant, 0.5-0.8 parts wetting agent, 0.1-0.12 parts defoamer, 45-48 parts pigment carbon black, 0.5-0.6 parts preservative, and 11.9-21.9 parts deionized water.

3. The high color low viscosity waterborne black of claim 1, wherein, The waterborne acrylic resin has a Brookfield viscosity of 3000-12000 mPa·s at 25°C and an acid value of 180-220 mgKOH / g.

4. The high color, low viscosity, aqueous black of claim 1, wherein, The dispersant includes acrylate copolymer dispersants.

5. The high color, low viscosity, aqueous black of claim 1, wherein, The wetting agent includes acetylenic diol surfactants.

6. The high color, low viscosity, aqueous black of claim 5, wherein, The defoamer is a polyether siloxane defoamer.

7. The high color, low viscosity, aqueous black of claim 1, wherein, The preservative includes nano-silver.

8. The high color, low viscosity, aqueous black of claim 7, wherein, The nano-silver has a particle size of 10-30 nm.

9. A process for the preparation of a high colour low viscosity aqueous black paste according to any one of claims 1 to 8, characterized in that, Includes the following steps: Add 70-80% of the total weight of water-based acrylic resin, dispersant, wetting agent, defoamer, and deionized water to a container and disperse for 10-15 minutes at 800-1200 r / min. Add pigment carbon black and continue dispersing for 30-40 minutes to obtain the dispersed material; Grind the dispersed material 4-5 times using a sand mill until the fineness is ≤10μm. Add the remaining deionized water and preservative, and disperse for 5-10 minutes.

10. An application of a high-color, low-viscosity water-based black paste according to any one of claims 1-8, characterized in that, It is used in the preparation of water-based coatings, water-based inks, or adhesives.

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