Environment-friendly water-based high total sunlight reflectance (TSR) pigment color paste as well as preparation method and application thereof

Abstract

The invention relates to an environment-friendly water-based high total sunlight reflectance (TSR) pigment color paste, which comprises the following components in percentage by mass: 40 to 70 percent of inorganic pigment, 0 to 40 percent of dispersing agent, 0 to 5 percent of wetting agent, 0 to 5 percent of defoaming agent and water, and the addition amount of water ensures that the sum of the mass percentages of the components is 100 percent. According to the pigment color paste, the inorganic pigment, the dispersing agent and other components are reasonably selected and matched, so that the heat management efficiency of a coating can be improved on the basis of not influencing the covering power, gloss, water resistance, adhesive force and other properties of the coating, and the temperature of a coated surface under the sunshine condition is effectively reduced. The pigment color paste is good in environmental protection property, high in total sunlight reflectance (TSR), high in covering power, high in tinting strength and good in compatibility with various water-based industrial coatings. The invention also comprises a preparation method and application of the environment-friendly water-based high total sunlight reflectance (TSR) pigment color paste.

Description

Technical Field

[0001] The present invention relates to the field of aqueous pigment pastes. Specifically, it relates to a high total solar reflectance (TSR), strong hiding power, high coloring power, environmentally friendly and general-purpose aqueous pigment paste, and its preparation method and application. Background Art

[0002] Heat management coatings are a type of coatings with excellent heat insulation performance, which can be used to control the heat transfer on the surface of buildings or other substrates. Such coatings usually have a high total solar reflectance (TSR) and low absorbency, and can reflect the radiation of sunlight and reduce heat absorption. Heat management coatings can be applied to the roofs, walls, facades, etc. of buildings, which can effectively reduce the indoor temperature, and are also expected to be used for the body painting of engineering vehicles, passenger cars, etc. to improve energy use efficiency.

[0003] Waterborne resin-free pastes are water-based pigment dispersions that do not contain organic solvents or volatile organic compounds, and have the advantages of environmental protection, easy processing, good stability, etc., and can be widely used in industries such as coatings, inks, adhesives, and plastics. With the continuous development of paste technology and the continuous improvement of environmental protection requirements, waterborne resin-free pastes are gradually replacing traditional organic solvent-based pastes and becoming the market mainstream.

[0004] Combining heat management technology with waterborne resin-free pastes can develop coating products with excellent thermal insulation performance. These products can not only effectively reflect the heat of sunlight, but also have the environmental protection characteristics of waterborne resin-free pastes. In the prior art, high-TSR pigment pastes are often applied to architectural coatings and less applied in the field of industrial coatings. The main reason is that industrial coatings are usually used in more severe environmental conditions and require higher durability and more lasting color stability. Therefore, higher requirements are placed on the color fastness and stability of the paste. In addition, industrial coatings need to be applied on different types of substrate materials, which also requires the paste used in combination with it to have a wider compatibility, be able to ensure high compatibility of the coating system adapted to various substrates, and provide good adhesion, water resistance, heat and humidity resistance, and corrosion resistance. Moreover, industrial coatings usually require more accurate control of the coating thickness to ensure meeting the process technical requirements of specific use scenarios, which also requires good rheological control performance during the process of paste coating to facilitate precise coating. These reasons make industrial coatings have higher requirements for high-TSR pigment pastes than architectural coatings, and pose corresponding challenges to the selection of pigments, dispersants, etc.

[0005] In view of this, there is a need to provide an environmentally friendly waterborne pigment paste with a high total solar reflectance (TSR) that can be applied to industrial coatings, which has high hiding power, strong coloring power, good compatibility with various waterborne industrial coatings, and can improve the heat management efficiency of the coatings without affecting the properties such as hiding power, gloss, water resistance, and adhesion of the coatings, and effectively reduce the temperature of the coated surface under sunlight, so as to solve the problems faced in the prior art field. Summary of the Invention

[0006] Based on the above facts, the object of the present invention is to provide an environmentally friendly waterborne pigment paste with a high total solar reflectance (TSR), which can achieve the improvement of the heat management efficiency of the coatings without affecting the properties such as hiding power, gloss, water resistance, and adhesion of the coatings, and effectively reduce the temperature of the coated surface under sunlight through the reasonable selection and combination of components such as inorganic pigments and dispersants. This pigment paste has good environmental protection, high total solar reflectance (TSR), high hiding power, strong coloring power, and good compatibility with various waterborne industrial coatings.

[0007] The first aspect of the present invention provides an environmentally friendly waterborne pigment paste with a high total solar reflectance (TSR), which, by mass percentage, includes:

[0008]

[0009] Among them, the addition amount of water makes the sum of the mass percentage of each component 100 wt%.

[0010] Inorganic pigment

[0011] In some embodiments of the present invention, the inorganic pigment is selected from inorganic pigments with relatively high total solar reflectance (TSR) values; preferably, the inorganic pigment is selected from one or more of iron oxide yellow (C.I. Pigment Yellow 42), iron oxide red (C.I. Pigment Red 101), bismuth vanadate (C.I. Pigment Yellow 184, Pigment Orange 82), titanium nickel yellow (C.I. Pigment Yellow 53), titanium chromium brown (C.I. Pigment Brown 24), cobalt titanium green (C.I. Pigment Green 50), chromium oxide green (C.I. Pigment Green 17), cobalt aluminum blue (C.I. Pigment Blue 28), cobalt chromium aluminum blue (C.I. Pigment Blue 36), ultramarine blue (C.I. Pigment Blue 29), iron chromium black (C.I. Pigment Brown 29), titanium manganese brown (C.I. Pigment Yellow 164), wherein the structure of the cobalt titanium green (C.I. Pigment Green 50) pigment is (Co)2TiO4; preferably, the TSR value of the inorganic pigment is preferably 20 - 80%; more preferably, by mass percentage, the amount of the inorganic pigment in the environmentally friendly waterborne pigment paste with a high total solar reflectance (TSR) is 45 - 60 wt%, which can be specifically determined according to the specific variety of the pigment.

[0012] Dispersant

[0013] In some embodiments of the present invention, the dispersant is an aqueous dispersant, selected from one or more of styrene / acrylic acid copolymer, acrylic acid / maleic acid copolymer, acrylic acid / methacrylic acid copolymer, butadiene / acrylic acid copolymer, isobutene / maleic acid copolymer, diisobutene / maleic acid copolymer, styrene / maleic acid copolymer, polyethylene glycol monovinyl ether / maleic acid copolymer; preferably, the dispersant is selected from one or more of the dispersants with model numbers BYK-190, EFKA-4575, Tego-752W, EFKA-4452 to meet the requirements of good color development, high stability, and good compatibility of the coating system when applied in aqueous industrial coatings; more preferably, by mass percentage, the dosage of the dispersant in the environmentally friendly aqueous high total solar reflectance (TSR) pigment paste is 5-30 wt%, which can be specifically determined according to the specific variety of the pigment.

[0014] Wetting agent

[0015] In the present invention, the wetting agent is selected from one or more of modified alkoxylates, polyether-modified siloxanes, ethoxylated acetylenic diols, and silicone double-effect surfactants, preferably the wetting agents provided by companies such as BASF and EVONIK; more preferably, by mass percentage, the dosage of the wetting agent in the environmentally friendly aqueous high total solar reflectance (TSR) pigment paste is 0-2 wt%.

[0016] Defoamer

[0017] In the present invention, the defoaming agent is selected from one or more of modified polysiloxanes and polymer-based defoaming agents, preferably the defoaming agents provided by companies such as BASF and EVONIK; more preferably, by mass percentage, the dosage of the defoaming agent in the environmentally friendly aqueous high total solar reflectance (TSR) pigment paste is 0-1 wt%.

[0018] Other additives

[0019] If necessary, an appropriate amount of rheology aid, bactericide or a combination thereof can also be added in the present invention. Exemplarily, the dosage of the rheology aid is 0.1-3 wt%, and the dosage of the bactericide is 0.1-1 wt%.

[0020] The second aspect of the present invention provides a method for preparing the environmentally friendly aqueous high total solar reflectance (TSR) pigment paste described in the first aspect of the present invention, comprising the following steps:

[0021] S1: Add a dispersant, a wetting agent, and an antifoaming agent to a portion of water, stir and mix evenly to obtain mixture A, where the amount of water added is such that the components in mixture A are evenly dispersed;

[0022] S2: Add an inorganic pigment to mixture A, obtain a homogeneous mixture through high-speed dispersion, and then perform sand grinding to grind the mixture to a fineness < 10 μm to obtain mixture B;

[0023] S3: Add the remaining water to mixture B, mix evenly, and then obtain the environmentally friendly water-based high total solar reflectance (TSR) pigment paste.

[0024] The machinery and equipment used in the preparation method are general equipment in a paint or pigment paste production factory, without complex processes, can be mass-produced industrially, and have good practicability.

[0025] If necessary, add a rheology aid or a bactericide. The rheology aid is added simultaneously with the dispersant, wetting agent, and antifoaming agent in step S1, and the bactericide is added simultaneously with the remaining water in step S3.

[0026] The third aspect of the present invention provides the application of the environmentally friendly water-based high total solar reflectance (TSR) pigment paste described in the first aspect of the present invention in water-based industrial paints. Specifically, the water-based industrial paints are selected from one or more of water-based two-component polyurethane paints, two-component epoxy paints, one-component acrylic paints, and water-based amino baking paints.

[0027] The beneficial effects of the present invention are as follows:

[0028] The present invention provides an environmentally friendly water-based high total solar reflectance (TSR) pigment paste, its preparation method and application. Through the reasonable selection and combination of components such as inorganic pigments and dispersants, the pigment paste can improve the heat management efficiency of the paint without affecting the properties such as the covering power, gloss, water resistance, and adhesion of the paint, and effectively reduce the temperature of the coated surface under sunlight. The pigment paste has good environmental protection, a high total solar reflectance (TSR) (preferably 20 - 80%), high covering power, strong coloring power, and good compatibility with various water-based industrial paints. Description of the Drawings

[0029] Figure 1 It is the test result of the total solar reflectance (TSR) of the pigment paste in Example 1 and Comparative Example 1 after being made into a water-based two-component epoxy paint sample.

[0030] Figure 2 It is the test result of the artificial simulated irradiation heating-up of the pigment paste in Example 1 and Comparative Example 1 after being made into a water-based two-component epoxy paint sample. Detailed Embodiments

[0031] To more clearly illustrate the present invention, the following further describes the present invention in conjunction with specific embodiments and comparative examples. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention. Without specific description, various raw materials of the present invention can be obtained commercially or prepared according to conventional methods in the art. All professional and scientific terms used in the present invention have the same meaning as those familiar to those skilled in the art. Any method or material similar to the described content can be applied to the method of the present invention.

[0032] The above technical solutions are described below in conjunction with specific embodiments.

[0033] Examples 1 - 4: Environmentally friendly waterborne high total solar reflectance (TSR) pigment pastes 1 - 4

[0034] Prepare the environmentally friendly waterborne high total solar reflectance (TSR) pigment pastes 1 - 4 of the present invention according to the formula in Table 1 below. The steps include:

[0035] S1: Add a dispersant, a wetting agent, an antifoaming agent, and a rheology aid to a part of water, and stir at a speed of 800 rpm - 1000 rpm for 10 - 20 min to obtain a mixture A, where the amount of water added is such that each component in the mixture A is uniformly dispersed;

[0036] S2: Add an inorganic pigment to the mixture A, gradually increase the mixer speed to 1500 - 2000 rpm, stir for 30 min, obtain a uniform mixture through high - speed dispersion, and then perform sanding to grind the mixture to a fineness < 10 μm to obtain a mixture B;

[0037] S3: Add the remaining water to the mixture B, mix evenly, and obtain the environmentally friendly waterborne high total solar reflectance (TSR) pigment pastes 1 - 4.

[0038] Comparative Examples 1 - 3: Pigment pastes 1 - 3 as comparative examples

[0039] Prepare the pigment pastes 1 - 3 as comparative examples according to the formula in Table 1 below. The steps are the same as those in Examples 1 - 4.

[0040] It should be noted that the pigment selected in the pigment paste 1 as the comparative example (TSR value is 14.8%) is not a pigment with a relatively high total solar reflectance (TSR) value and is not within the protection scope of the present invention, so it is Comparative Example 1. Selecting a pigment without a relatively high total solar reflectance (TSR) value will result in the pigment paste not having the ability of high total solar reflectance (TSR).

[0041] In the pigment pastes 2 and 3 as the comparative examples, the dispersants selected are different from those in the examples, and the properties such as storage stability, viscosity, coloring power, etc. of the prepared pastes decline.

[0042] Table 1 Raw material components of the pigment pastes in Examples 1-4 and Comparative Examples 1-3

[0043]

[0044]

[0045] The product performance of the obtained pigment pastes in Examples 1-4 and Comparative Examples 1-3 was tested. The specific test items were fineness, viscosity, coloring power and stability tests of the pigment pastes.

[0046] The relevant test methods are as follows:

[0047] The fineness test method refers to the national standard GB 1724-79.

[0048] The viscosity test method refers to the national standard GB / T 9269-2009.

[0049] The base material selected for the coloring power test was an aqueous two-component polyurethane white paint, and the coloring power of the pigment paste before heat storage was used as the benchmark.

[0050] The stability test refers to the national standard GB / T 6753.3-1986. The samples were taken out after being placed in an oven (50±2°C) for 30 days and stored under the condition of (23±2°C) for 6 hours. Whether there were obvious pigment particle sedimentation or flocculation and other conditions seriously affecting stability was observed by visual inspection. "√" indicates no abnormality by visual inspection, and "×" indicates obvious pigment particle precipitation, flocculation, etc. by visual inspection, and the changes in fineness, viscosity and coloring power were compared with the normal temperature samples.

[0051] The test results are shown in Table 2:

[0052] Table 2 Test results of the obtained pigment pastes in Examples 1-4 and Comparative Examples 1-3

[0053]

[0054]

[0055] It can be seen from Table 2 that the pigment pastes obtained in Examples 1-4 can pass the performance tests such as fineness, viscosity, coloring power and stability, and show better storage stability than the pigment pastes obtained in Comparative Examples 1-3. For example, after heat storage, the stability of fineness, viscosity and coloring power is shown.

[0056] Example 5: Application of the pigment pastes prepared in Examples 1-4 and Comparative Example 1 in waterborne industrial coatings

[0057] According to the formulations in Tables 4-6 below, the pigment pastes prepared in Examples 1-4 and Comparative Example 1 were respectively added to waterborne DTM varnish, waterborne two-component polyurethane varnish, and waterborne two-component epoxy varnish, and the addition amount of the pigment paste was 15% of the total mass of the final coating system.

[0058] Among them, the gloss (60°) was measured according to GB / T 9754, and the water resistance was carried out according to the method A specified in GB / T 1733-1993. The test results are shown in Table 3.

[0059] Table 3 Physical property test results of the pigment pastes obtained in Examples 1-4 and Comparative Example 1 when formulated into waterborne coatings

[0060]

[0061] Table 4 Composition formula of waterborne DTM coating in Example 5

[0062]

[0063] Table 5 Composition formula of waterborne two-component polyurethane coating in Example 5

[0064]

[0065] Table 6 Composition formula of waterborne two-component epoxy coating in Example 5

[0066]

[0067]

[0068] As can be seen from Table 3, when the pigment pastes prepared in Examples 1-4 were added to the above three industrial coating systems, they had good engineering covering ability, good anti-floating color and blooming ability (visually no floating color in the can, finger rubbing color difference △E < 0.5), high gloss, and good water resistance performance, which were overall superior to the performance of the pigment paste prepared in Comparative Example 1 in the three industrial coating systems.

[0069] Example 6: Total solar reflectance (TSR) test and artificial simulation irradiation heating test of the full-coat samples of the pigment pastes obtained in Example 1 and Comparative Example 1

[0070] The pigment pastes obtained in Example 1 and Comparative Example 1 were formulated into waterborne two-component epoxy coatings and adjusted to similar colors. At the same time, the corresponding white-diluted waterborne two-component epoxy coatings of Example 1 and Comparative Example 1 were formulated and adjusted to similar colors (L*, a*, b* data are shown in Table 7). The coatings were sprayed into samples using an electrostatic spraying atomization device, and the total solar reflectance (TSR) test and artificial simulated irradiation heating test were carried out on the samples. The test results of the total solar reflectance (TSR) are as Figure 1 shown. The test results of the artificial simulated irradiation heating test are as Figure 2 shown.

[0071] Among them, the relevant test methods are as follows:

[0072] The total solar reflectance (TSR) was measured and calculated according to ISO9845-1.

[0073] The artificial simulated irradiation heating test was carried out according to the self-built laboratory scheme. Among them, the irradiation lamp was a 500W halogen lamp, 35 cm away from the sample, and the standard test time was 30 min. A contact thermal resistance thermometer was used to measure the temperature at the bottom of the sample to obtain accurate and reliable temperature values.

[0074] Table 7 L*, a*, b* values of the waterborne two-component epoxy coating spray plates in Example 1 and Comparative Example 1

[0075]

[0076]

[0077] As can be seen from Figure 1 , the total solar reflectance (TSR) of Example 1 is higher than the corresponding value of Comparative Example 1, and the total solar reflectance (TSR) of the white-diluted Example 1 is higher than the corresponding value of the white-diluted Comparative Example 1. At the same time, as shown in Figure 2 , for the equilibrium temperature reached by the sample after 30 minutes in the artificial simulated irradiation experiment, it was 85.6 °C for Example 1, lower than 91.0 °C for Comparative Example 1; it was 80.9 °C for the white-diluted Example 1, lower than 88.5 °C for the white-diluted Comparative Example 1. The results show that the color-adjusted coating sample using the pigment paste obtained in Example 1 has a lower surface temperature under the same artificial simulated irradiation conditions.

[0078] In summary, the environmentally friendly waterborne pigment paste with high total solar reflectance (TSR) of the present invention has stable performance and good storage stability. No instability problems such as fineness coarsening, viscosity increase, and coloring power decrease will occur during the heat storage experiment. At the same time, the waterborne resin-free pigment paste prepared by this method can be applied to common waterborne industrial coatings, showing good compatibility, high hiding power, excellent water resistance and damp heat resistance. In addition, the coating using this environmentally friendly waterborne pigment paste with high total solar reflectance (TSR) shows a high total solar reflectance (TSR), accumulates less solar radiation energy, and demonstrates excellent heat management ability.

[0079] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation manners here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. An environmentally friendly water-based pigment paste with a high total solar reflectance (TSR), by mass percentage, it includes: Among them, the addition amount of water makes the sum of the mass percentages of each component 100 wt%.

2. The environmentally friendly aqueous high total solar reflectance (TSR) pigment paste according to claim 1, wherein It also includes one or a combination of a rheology aid and a bactericide.

3. The environmentally friendly aqueous high total solar reflectance (TSR) pigment paste according to claim 1 or 2, characterized in that, The inorganic pigment is an inorganic pigment with a high total solar reflectance (TSR) value; preferably, the inorganic pigment is selected from iron oxide yellow (C.I. Pigment Yellow 42), iron oxide red (C.I. Pigment Red 101), bismuth vanadate (C.I. Pigment Yellow 184, Pigment Orange 82), titanium nickel yellow (C.I. Pigment Yellow 53), titanium chromium brown (C.I. Pigment Brown 24), cobalt titanium green (C.I. Pigment Green 50), chromium oxide green (C.I. Pigment Green 17), cobalt aluminum blue (C.I. Pigment Blue 28), cobalt chromium aluminum blue (C.I. Pigment Blue 36), ultramarine blue (C.I. Pigment Blue 29), iron chromium black (C.I. Pigment Brown 29), titanium manganese brown (C.I. Pigment Yellow 164), and one or several of them, wherein the structure of the cobalt titanium green (C.I. Pigment Green 50) pigment is (Co)2TiO4; more preferably, by mass percentage, the dosage of the inorganic pigment in the environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) is 45-60 wt%.

4. The environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) according to claim 1 or 2, characterized in that, The dispersant is a water-based dispersant, selected from one or several of styrene / acrylic acid copolymer, acrylic acid / maleic acid copolymer, acrylic acid / methacrylic acid copolymer, butadiene / acrylic acid copolymer, isobutene / maleic acid copolymer, diisobutene / maleic acid copolymer, styrene / maleic acid copolymer, polyethylene glycol monovinyl ether / maleic acid copolymer; preferably, the dispersant is selected from one or several of the dispersants with model numbers BYK-190, EFKA-4575, Tego-752W, EFKA-4452; more preferably, by mass percentage, the dosage of the dispersant in the environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) is 5-30 wt%.

5. The environmentally friendly aqueous high total solar reflectance (TSR) pigment paste according to claim 1 or 2, characterized in that, The wetting agent is selected from one or several of modified alkoxylates, polyether-modified siloxanes, ethoxylated alkynediols, and silicone double-effect surfactants; preferably, by mass percentage, the dosage of the wetting agent in the environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) is 0-2 wt%.

6. The environmentally friendly aqueous high total solar reflectance (TSR) pigment paste according to claim 1 or 2, characterized in that, The defoaming agent is selected from one or several of modified polysiloxanes and polymer-based defoaming agents; preferably, by mass percentage, the dosage of the defoaming agent in the environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) is 0-1 wt%.

7. The environmentally friendly aqueous high total solar reflectance (TSR) pigment paste according to claim 1 or 2, characterized in that The TSR value of the inorganic pigment is preferably 20-80%.

8. The environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) according to claim 1 or 2, characterized in that, The TSR value of the environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) is preferably 20-80%.

9. A preparation method of the environmentally friendly water-based pigment paste with a high total solar reflectance (TSR) according to any one of claims 1-8, including the following steps: S1: Add a dispersant, a wetting agent, and an antifoaming agent to a portion of water, stir and mix evenly to obtain mixture A, where, The addition amount of water is based on the ability to make each component in mixture A disperse evenly; S2: Add inorganic pigments to mixture A, and obtain a uniform mixture through high-speed dispersion. Subsequently, perform sanding to grind the mixture to a fineness of <10 μm to obtain mixture B; S3: Add the remaining water to mixture B, and after mixing evenly, the environmentally friendly waterborne high total solar reflectance (TSR) pigment paste is obtained.

10. Application of an environment-friendly water-based pigment paste with a high total solar reflectance (TSR) as described in any one of claims 1-8 in water-based industrial coatings, characterized in that, The waterborne industrial coating is selected from one or more of waterborne two-component polyurethane coatings, two-component epoxy paints, one-component acrylic coatings, and waterborne amino baking paints.

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