Coating composition and coated article

Abstract

The invention relates to a coating composition and a coated article. The coating composition comprises: at least one polyaspartic acid ester, and a surface-modified filler having an oil absorption of 20 g / 100 g or less, wherein the viscosity of the coating composition at 25 DEG C does not exceed 17000 cps. The coating composition of the present application can obtain a good texture effect even in the absence of a texture additive. In addition, the coating composition has the advantages of being low in VOC emission, quick to dry at normal temperature, suitable for construction and the like. Also disclosed is an article comprising a substrate and a coating composition or a cured coating layer thereof applied to the substrate.

Description

Technical Field

[0001] The present application relates to a coating composition and a coated article, and more particularly to a coating composition containing a polyaspartate ester and a coated article. Background Art

[0002] With the enhancement of people's environmental awareness and the increasingly strict regulations on the emissions of volatile organic compounds (VOCs), solvent-based coating compositions are usually required to have a low VOC content. Waterborne coatings usually have a relatively low VOC content, but they require high-temperature baking for curing and have a slow drying speed.

[0003] Moreover, when a textured effect is desired, waterborne coatings with a low VOC content perform unsatisfactorily. As a result, traditional liquid coatings cannot provide a textured paint that can simultaneously meet the requirements of low VOC and fast drying at room temperature.

[0004] Therefore, there is a need in the coating industry for a textured paint that has both low VOC and fast drying at room temperature. Summary of the Invention

[0005] The inventors have found that by using the coating composition described herein, the above-mentioned objectives can be achieved. The coating composition described herein can provide a textured paint that has both low VOC and fast drying at room temperature.

[0006] A first aspect of the present application provides a coating composition comprising: at least one polyaspartate ester, and a surface-modified filler having an oil absorption of 20 g / 100 g or less, wherein the viscosity of the coating composition does not exceed 17,000 cps at 25°C.

[0007] A second aspect of the present application provides a coated article comprising: a substrate having at least one surface; and a coating composition or its cured coating directly or indirectly coated on at least a part of the at least one surface of the substrate, wherein the coating composition is the coating composition described in the first aspect of the present application.

[0008] The inventors of the present application have surprisingly found that the coating composition described herein can achieve a good textured effect. In particular, in the coating composition described herein, by combining a polyaspartate ester having an extremely high solid content (the solid content is up to about 95% by weight, even close to 100% by weight) and a low viscosity with a surface-modified filler having an oil absorption of 20 g / 100 g or less, and controlling the viscosity of the coating composition, it is possible to make the coating composition have low VOC emissions and fast drying at room temperature, while providing an excellent textured effect. To the inventors' knowledge, so far, there has been no disclosure or teaching in the art of such a combination of a high-solid and low-viscosity polyaspartic resin and a filler with a low oil absorption, let alone the excellent effects produced by this combination.

[0009] Moreover, the inventors have also found that in the art, a texture effect is usually obtained by adding a texture aid (e.g., in an acrylic resin). However, such added texture aids are not widely applicable to all coating compositions, and the obtained texture effect is also unstable. The inventors have surprisingly found that even in the absence of a texture aid, the coating compositions described herein can still obtain a good texture effect. Even more, the inventors have found that in some of the coating compositions described herein, adding a texture aid does not significantly increase the texture effect as in an acrylic resin system.

[0010] In addition, the coating compositions of the present application also have good workability and economy.

[0011] Details of one or more embodiments of the present application are set forth in the following description. Other features, objects, and advantages of the present application will become apparent from the description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention will be briefly introduced below. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0013] Figure 1 Shows the texture effect of the cured coating obtained from the coating composition in Example 1.

[0014] Figure 2 Shows the texture effect of the cured coating obtained from the coating composition in Comparative Example 1.

[0015] Figure 3 Shows the texture effect of the cured coating obtained from the coating composition in Comparative Example 4.

[0016] Figure 4 Shows the texture effect of the cured coating obtained from the coating composition in Comparative Example 7.

[0017] Figure 5 Shows the texture effect of the cured coating obtained from the coating composition in Example 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Definition

[0019] As used herein, the terms "a," "an," "the," "at least one," and "one or more" may be used interchangeably with or without a numerical quantifier. Thus, for example, a component containing "a" additive can be interpreted to mean that the component contains "one or more" additives. Unless otherwise specified herein, the use of the singular form herein is also intended to include the plural form.

[0020] Unless otherwise expressly stated, the use of the terms "comprising," "including," "containing," "having" should generally be interpreted as open-ended and non-limiting. For example, in the case where a composition is described as comprising or including a particular component, it is contemplated that optional components not covered by this application are not excluded from the composition, and it is contemplated that the composition can consist of or be composed of the components involved. Or in the case where a method is described as comprising or including a particular process step, it is contemplated that optional process steps not covered by this application are not excluded from the method, and it is contemplated that the method can consist of or be composed of the process steps involved.

[0021] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, although not explicitly recited, each point or single value between the range endpoints is included within the range. Thus, each point or single value can be used as its own lower or upper limit and combined with any other point or single value or with other lower or upper limits to form a range not explicitly recited.

[0022] Unless otherwise specified, each point or single value between the range endpoints is included within the range. For example, the range from 1 to 5 encompasses the values 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc. Moreover, the disclosed numerical ranges include all sub-ranges within that broader range. For example, the range from 1 to 5 includes the sub-ranges from 1 to 4, from 1.5 to 4.5, from 1 to 2, etc. Thus, each point or single value can be used as a lower or upper limit and combined with any other point or single value or with other lower or upper limits, and the resulting range is part of what is explicitly disclosed in this application.

[0023] As used herein, the term "or" is inclusive. That is, the phrase "A or B" means "A, B, or both A and B", and may also be abbreviated as "A and / or B". More specifically, the condition "A or B" is satisfied by any of the following: A is true (or present) and B is false (or absent); A is false (or absent) while B is true (or present); or both A and B are true (or present). In contrast, the exclusive "or" is represented herein by terms such as "either A or B" and "one of A or B".

[0024] As used herein, "coating" has the same meaning as "paint film", both of which are formed after a coating composition is applied and cured.

[0025] When used in the context of "a coating applied to a surface or substrate", the term "on" includes a coating that is applied directly or indirectly to the surface or substrate. Thus, for example, a coating on a primer layer applied to a substrate is counted as a coating applied to the substrate.

[0026] The term "substantially free of" a certain compound means that the coating composition contains less than 1000 parts per million (ppm) of the compound; the term "essentially free of" a certain compound means that the coating composition contains less than 100 ppm of the compound; the term "essentially completely free of" a certain compound means that the coating composition contains less than 5 ppm of the compound; the term "completely free of" a certain compound means that the coating composition contains less than 20 parts per billion (ppb) of the compound.

[0027] In the context of the present application, the term "two-component coating composition" means a coating composition composed of two or more separately stored components, which are mixed together during use and can dry and cure within an acceptable period of time to form a coating having the desired mechanical properties (such as hardness).

[0028] When used in reference to "polyaspartate", the term "amine equivalent" refers to the mass of polyaspartate ester containing 1 equivalent of secondary amino groups. Generally, the lower the amine equivalent, the more secondary amino groups contained in the polyaspartate and the stronger the reactivity.

[0029] The terms "preferred" and "preferably" refer to embodiments of the present invention that can provide certain advantages in certain circumstances. However, in the same or other circumstances, other embodiments may also be preferred. In addition, the recitation of one or more preferred embodiments does not mean that other embodiments are unavailable and is not intended to exclude other embodiments within the scope of the present invention.

[0030] Coating composition

[0031] On the one hand, the present application provides a coating composition, which comprises: at least one polyaspartate, and a surface-modified filler having an oil absorption of 20 g / 100 g or less, wherein the viscosity of the coating composition does not exceed 17,000 cps at 25 °C. This coating composition can provide a textured paint that simultaneously has low VOC and fast drying at room temperature. In particular, this coating composition can provide a non-bake textured paint.

[0032] By combining a high-solid and low-viscosity polyaspartate with a filler having a low oil absorption and controlling the viscosity of the coating composition, it is possible to enable the coating composition to provide a paint with low VOC emissions, fast drying at room temperature, and excellent texture effects.

[0033] In some embodiments, the viscosity of the coating composition does not exceed 17,000 cps at 25 °C, preferably 8,000 - 16,000 cps, more preferably 9,000 - 15,000 cps. For example, the viscosity of the coating composition is 8,000 cps, 8,500 cps, 9,000 cps, 9,500 cps, 10,000 cps, 10,500 cps, 11,000 cps, 11,500 cps, 12,000 cps, 12,500 cps, 13,000 cps, 13,500 cps, 14,000 cps, 14,500 cps, 15,000 cps, 16,000 cps or 17,000 cps at 25 °C, or within a range composed of any of the above values.

[0034] Preferably, the coating composition described herein can have a relatively large viscosity when meeting the construction requirements. This relatively large viscosity is beneficial for the formation of three-dimensional texture. Without wishing to be bound by theory, during the construction of the coating composition described herein, the shear force during air spraying (compressed air) or airless spraying will cause the system viscosity to decrease; after the shear force disappears, the system viscosity rapidly increases within a short time, thereby achieving very excellent texture effects.

[0035] The coating composition according to the present application comprises polyaspartate as a resin component or a part thereof or as an additive. Polyaspartate is a component known to those skilled in the art of coatings, and it is a polyamine having at least one secondary amino group (for example, two secondary amino groups). In some embodiments, at least one polyaspartate has at least two secondary amino groups. Polyaspartate is particularly suitable for formulating solvent-based coating compositions with low VOC content because it has an extremely high solid content and a very low viscosity.

[0036] In the coating compositions described herein, the polyaspartate has a relatively low number-average molecular weight and an appropriate NH equivalent, and has excellent reactivity. More importantly, the inventors have found that in a coating composition comprising a high-solids, low-viscosity polyaspartate and a filler with low oil absorption, the texture effect can be further improved by selecting an appropriate viscosity.

[0037] In some embodiments, the number-average molecular weight of the polyaspartate can be between 300 g / mol and 1200 g / mol, preferably between 350 g / mol and 1000 g / mol, and even more preferably in the range between 400 g / mol and 800 g / mol. For example, the number-average molecular weight of the polyaspartate can be 300 g / mol, 350 g / mol, 400 g / mol, 450 g / mol, 500 g / mol, 550 g / mol, 600 g / mol, 650 g / mol, 700 g / mol, 750 g / mol, 800 g / mol, 900 g / mol, 1000 g / mol, 1100 g / mol or 1200 g / mol, or in a range consisting of any of the above values. Methods and equipment known in the art can be used to determine the number-average molecular weight. For example, the molecular weight can be determined by gel permeation chromatography (GPC) according to ISO 13885-1:2008. If the molecular weight of the polyaspartate is too high, the viscosity of the molecule will increase sharply, which is not conducive to formulating a low-VOC coating composition; if the molecular weight is too low, the establishment of the film strength will be too slow, which is not conducive to the coating reaching dry-to-touch quickly.

[0038] In some embodiments, the viscosity of the polyaspartate can be 300 - 3000 cps, preferably 500 - 2800 cps, more preferably 700 - 2500 cps, and even more preferably 900 - 2000 cps. For example, the viscosity of the polyaspartate can be 300 cps, 400 cps, 500 cps, 600 cps, 700 cps, 800 cps, 900 cps, 1000 cps, 1100 cps, 1200 cps, 1300 cps, 1400 cps, 1500 cps, 1600 cps, 1700 cps, 1800 cps, 1900 cps, 2000 cps, 2100 cps, 2200 cps, 2500 cps, 2800 cps or 3000 cps, or in a range consisting of any of the above values.

[0039] In some embodiments, the amine equivalent weight of the polyaspartate ester can be between about 150 g / eq and 450 g / eq, preferably between 200 g / eq and 400 g / eq, more preferably between 250 g / eq and 350 g / eq. For example, the amine equivalent weight of the polyaspartate ester can be about 150 g / eq, 180 g / eq, 200 g / eq, 220 g / eq, 250 g / eq, 270 g / eq, 300 g / eq, 320 g / eq, 350 g / eq, 380 g / eq, 400 g / eq, 420 g / eq, or 450 g / eq, or within a range composed of any of the above values. The amine equivalent weight is calculated from the amine value according to the following formula: Amine equivalent weight = 56.1×1000 / [Amine value], where the amine value can be determined according to ASTM D2074. The amine equivalent weight of the polyaspartate ester is a parameter that measures the reactivity of the resin molecules. Similar to the epoxy equivalent weight, the amine equivalent weight refers to the mass of the polyaspartate ester containing 1 equivalent of secondary amino groups. Generally, the lower the amine equivalent weight, the more secondary amino groups are contained in the polyaspartate ester, and the stronger the reactivity.

[0040] As an illustrative example, the polyaspartate ester can have a structure represented by the following general formula (I):

[0041]

[0042] wherein X represents an aliphatic group or an alicyclic group that is inert to isocyanate groups at temperatures up to 100°C; R1 and R2 are each independently selected from organic groups that are inert to isocyanate groups at temperatures up to 100°C; R3 and R4 are each independently selected from hydrogen and organic groups that are inert to isocyanate groups at temperatures up to 100°C; and n is an integer from 2 to 6.

[0043] In some embodiments, X is an n-valent organic group optionally containing one or more heteroatoms, which can be obtained by removing primary amino groups from a polyamine having (cyclo)aliphatic or arylaliphatic bonding, and can contain other functional groups that are reactive to isocyanate groups and / or inert at temperatures up to 100°C. Preferably, the polyamine can have the structure of. For example, examples of polyamines include the following compounds: ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 2,5-diamino-2,5-dimethylhexane, 1,5-diamino-2-methylpentane ( DuPont), 1,6 - diaminohexane, 2,2,4 - and / or 2,4,4 - trimethyl - 1,6 - diaminohexane, 1,11 - diamino undecane, 1,12 - diamino dodecane, triaminononane, 1 - amino - 3,3,5 - trimethyl - 5 - aminomethyl - cyclohexane, 4,4'-diamino - dicyclohexylmethane, 3,3 - dimethyl - 4,4'-diamino - dicyclohexylmethane, 4,9 - dioxadodecane - 1,12 - diamine or 4,7,10 - trioxatridecane - 1,13 - diamine. Also useful are aliphatic polycyclic polyamines such as tricyclodecane dimethylamine (TCD diamine) or bis(aminomethyl)norbornane.

[0044] For example, X can be an alicyclic group containing 6 to 20 carbon atoms. Preferably, X represents a divalent hydrocarbon group obtained by removing an amino group from: 1,4 - diamino butane, 1,6 - diaminohexane, 2,2,4 - and 2,4,4 - trimethyl - 1,6 - diaminohexane, 1 - amino - 3,3,5 - trimethyl - 5 - aminomethyl - cyclohexane, 4,4'-diamino - dicyclohexylmethane or 3,3 - dimethyl - 4,4'-diamino - dicyclohexylmethane.

[0045] In some embodiments, n can be 2, 3 or 4.

[0046] For example, n can be 2. The polyaspartic acid ester can have a structure represented by the following general formula (II) or (III):

[0047]

[0048]

[0049] Preferably, R1 and R2 represent C1 - C 18 alkyl, more preferably C1 - C8 alkyl, even more preferably C1 - C6 alkyl. For example, R1 and R2 each independently represent methyl, ethyl, propyl, isopropyl, butyl or isobutyl. Very particularly preferably, R1 and R2 each independently represent methyl or ethyl.

[0050] Preferably, R3 and R4 each independently represent hydrogen.

[0051] As described in U.S. Patent No. 5,126,170, polyaspartic acid ester amines can be prepared by reacting one or more cyclic polyamines containing primary amine groups with unsaturated dialkyl esters.

[0052] Cyclic polyamine components containing more than one primary amine group for the manufacture of polyaspartic esters generally contain 6 to 25 carbon atoms and contain at least one alicyclic ring. Examples of suitable alicyclic diamine components include 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,6-diaminocyclohexane, 2,2,4- and 2,4,4-trimethyl-1,6-diaminohexane, 1-amino-3,3,5-trimethyl-5-aminomethylhexane and preferably include bis(aminomethyl)cyclohexanes such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophorone diamine, bis(4-aminocyclohexyl)methane, bis(4-aminocyclohexyl)propane, 4,4-diamino-3,3-dimethylbicyclohexylmethane, 4,4-diamino-3,3-dimethylbicyclohexylpropane, 4,4-diamino-3,3-dimethyl-5,5-dimethylbicyclohexylmethane, 4,4-diamino-3,3-dimethyl-5,5-dimethylbicyclohexylpropane.

[0053] Unsaturated dialkyl esters for the manufacture of polyaspartic esters are preferably diethyl maleate, such as esters of maleic acid or fumaric acid, such as dimethyl, diethyl, dipropyl and di-n-butyl esters of maleic acid and fumaric acid.

[0054] The polyaspartic esters disclosed above can be made, for example, by techniques well known to those of ordinary skill in the art. As examples of polyaspartic esters, any conventional polyaspartic esters can be used, such as the NH series products purchased from Bayer Material Science AG (Leverkusen, Germany), or the Asp series products purchased from Shenzhen Feiyang Junyan New Materials Co., Ltd., such as Aspartic polyurea resin F420, F520, etc.

[0055] In some embodiments, based on the total weight of the coating composition, the amount of the at least one polyaspartic ester can be 15-35% by weight, preferably 20-30% by weight. For example, based on the total weight of the coating composition, the amount of the at least one polyaspartic ester can be 15% by weight, 18% by weight, 20% by weight, 22% by weight, 25% by weight, 28% by weight or 30% by weight, or in a range consisting of any of the above values.

[0056] In some embodiments, the coating composition can contain two or more polyaspartic esters. For example, the coating composition can contain two or three polyaspartic esters. In some exemplary embodiments, the coating composition can contain two polyaspartic esters, and the weight ratio of the two can be from 1:10 to 10:1. Preferably, the weight ratio of the two polyaspartic esters can be from 1:8 to 8:1, more preferably from 1:5 to 5:1.

[0057] In the coating compositions described herein, the surface-modified filler has a very low oil absorption. Preferably, the oil absorption of the surface-modified filler is 18 g / 100 g or lower, more preferably 16 g / 100 g or lower, and even more preferably 14 g / 100 g or lower. For example, the oil absorption of the surface-modified filler can be about 20 g / 100 g, 19 g / 100 g, 18 g / 100 g, 17 g / 100 g, 16 g / 100 g, 15 g / 100 g, 14 g / 100 g, 13 g / 100 g, 12 g / 100 g, 11 g / 100 g, 10 g / 100 g, 9 g / 100 g, 8 g / 100 g, 7 g / 100 g, 6 g / 100 g, or 5 g / 100 g, or within a range composed of any of the above values. In some exemplary embodiments, the oil absorption of the surface-modified filler is about 6 - 12 g / 100 g, 8 - 15 g / 100 g, or 10 - 15 g / 100 g. The oil absorption can be measured using methods and equipment known in the art. For example, it can be measured in accordance with GB / T5211.15 - 2014. The inventors have found that by selecting a surface-modified filler with an appropriate oil absorption, the texture effect of the cured coating can be improved.

[0058] In some embodiments, the surface-modified filler has a surface-modified portion and a core portion. The core portion can be one or more of precipitated barium sulfate, barite powder, heavy calcium carbonate, rutile titanium dioxide, talc powder with a mesh size of 350 or coarser (e.g., 325 mesh), and quartz powder with a mesh size of 350 or coarser (e.g., 325 mesh). Preferably, the core portion can be one or more of precipitated barium sulfate, barite powder, heavy calcium carbonate, and rutile titanium dioxide. Particularly preferably, the core portion can be precipitated barium sulfate, barite powder, or a combination thereof.

[0059] In some embodiments, the D50 of the surface-modified filler is in the range of 0.8 - 2 μm, preferably in the range of 0.9 - 1.8 μm, and more preferably in the range of 1.0 - 1.5 μm. For example, the D50 of the surface-modified filler can be about 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2.0 μm, or within a range composed of any of the above values.

[0060] In some embodiments, the D97 of the surface-modified filler is in the range of 3 - 10 μm, preferably in the range of 3.2 - 8.0 μm, and more preferably in the range of 3.5 - 6.0 μm. For example, the D50 of the surface-modified filler can be about 3.0 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4.0 μm, 4.2 μm, 4.5 μm, 4.8 μm, 5.0 μm, 5.2 μm, 5.5 μm, 5.8 μm, 6.0 μm, 7.0 μm, 8.0 μm, 9.0 μm or 10.0 μm, or in the range composed of any of the above values.

[0061] In some embodiments, the specific gravity of the surface-modified filler is in the range of 2 - 6 g / cm 3 Preferably in the range of 2.2 - 5.5 μm, and more preferably in the range of 2.5 - 5.0 μm. For example, the specific gravity of the surface-modified filler can be about 2.0 μm, 2.2 μm, 2.5 μm, 2.8 μm, 3.0 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4.0 μm, 4.2 μm, 4.3 μm, 4.4 μm, 4.5 μm, 4.8 μm, 5.0 μm, 5.2 μm, 5.5 μm, 5.8 μm or 6.0 μm, or in the range composed of any of the above values.

[0062] In some embodiments, the bulk density of the surface-modified filler is in the range of 0.3 - 5 g / cm 3 Preferably in the range of 0.5 - 4.0 g / cm 3 More preferably in the range of 0.8 - 3.0 g / cm 3 For example, the bulk density of the surface-modified filler can be about 0.3 g / cm 3 , 0.5 g / cm 3 , 0.6 g / cm 3 , 0.7 g / cm 3 , 0.8 g / cm 3 , 0.9 g / cm 3 , 1.0 g / cm 3 , 1.2 g / cm 3 , 1.3 g / cm 3 , 1.5 g / cm 3 , 1.8 g / cm 3 , 2.0 g / cm 3 , 3.0 g / cm 3 , 3.5 g / cm 3 , 4.0 g / cm 3 , 4.5 g / cm 3 or 5.0 g / cm 3 , or in the range composed of any of the above values.

[0063] In some embodiments, the compacted density of the surface-modified filler is in the range of 0.5 - 6 g / cm 3 Preferably in the range of 0.8 - 5.0 g / cm 3 More preferably in the range of 1.0 - 4.0 g / cm 3 For example, the compacted density of the surface-modified filler can be about 0.5 g / cm 3 、0.6 g / cm 3 、0.7 g / cm 3 、0.8 g / cm 3 、0.9 g / cm 3 、1.0 g / cm 3 、1.2 g / cm 3 、1.3 g / cm 3 、1.5 g / cm 3 、1.6 g / cm 3 、1.7 g / cm 3 、1.8 g / cm 3 、1.9 g / cm 3 、2.0 g / cm 3 、2.1 g / cm 3 、2.2 g / cm 3 、2.5 g / cm 3 、3.0 g / cm 3 、3.5 g / cm 3 、4.0 g / cm 3 、4.5 g / cm 3 、5.0 g / cm 3 、5.5 g / cm 3 or 6.0 g / cm 3 , or within a range composed of any of the above values.

[0064] In some embodiments, the surface-modified filler is surface-treated by compound coating with one or more of a silane coupling agent, silica-alumina, and a polymer. This surface modification can further facilitate both good mixing of the filler with the resin and obtaining a cured coating with excellent texture effects.

[0065] In some embodiments, the silane coupling agent has Y(CH2) mSiX₃, where m = 0, 1, 2 or 3, Y is or contains one or more groups selected from alkenyl, (meth)acryloyloxy, aminoalkyl, isocyanatoalkyl, epoxyalkyl, ureidoalkyl, and each X is independently selected from methyl, ethyl, halogen, methoxy, ethoxy, propoxy, isopropoxy or trimethylsiloxy, provided that at least one X is methoxy, ethoxy, propoxy, isopropoxy or trimethylsiloxy.

[0066] Preferably, the silane coupling agent has a double bond and a large steric hindrance. In some embodiments, the silane coupling agent is selected from vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, (meth)acryloyloxypropyltrimethoxysilane, (meth)acryloyloxypropyltriethoxysilane, (meth)acryloyloxypropylmethyldimethoxysilane, (meth)acryloyloxypropylmethyldiethoxysilane, (meth)acryloyloxypropyltris(trimethylsiloxy)silane, γ-aminopropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, diethoxymethyl[(3-oxiranylmethoxy)propyl]silane. Preferably, the silane coupling agent is selected from one or more of vinyltriisopropoxysilane, acryloyloxypropyltriethoxysilane, γ-methacryloyloxypropyltriethoxysilane, γ-isocyanatopropyltriethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate.

[0067] In some embodiments, the amount of the silane coupling agent can be 0.02 to 10% by weight based on the total weight of the surface-modified filler. For example, based on the total weight of the one-component coating composition, the amount of the silane coupling agent can be about 0.02% by weight, 0.05% by weight, 0.1% by weight, 0.5% by weight, 1% by weight, 1.2% by weight, 1.5% by weight, 1.8% by weight, 2% by weight, 2.5% by weight, 3% by weight, 3.5% by weight, 4% by weight, 5% by weight or 8% by weight. Preferably, the amount of the silane coupling agent can be 1.5 to 4% by weight. Other ranges formed by the above values, the upper and lower limits of the above ranges can also be used.

[0068] In some embodiments, the molecular weight of the silane coupling agent is 100 - 800 daltons, preferably 200 - 400 daltons, such as about 150 daltons, about 250 daltons, 300 daltons.

[0069] Preferably, the silane coupling agent is an epoxy silane coupling agent. For example, Y is an alkyl group capped with an epoxy group.

[0070] The inventors found that on the one hand, the active groups of the silane coupling agent can react with the surface of the substrate, improving the adhesion of the coating to the substrate; on the other hand, the silane coupling agent can further control the viscosity change of the filler in the coating composition, improving the texture effect of the coating. In particular, when an epoxy silane coupling agent is used, these two benefits are more prominent.

[0071] In some embodiments, based on the total weight of the coating composition, the amount of the surface-modified filler is 20-60% by weight, preferably 25-55% by weight, more preferably 30-50% by weight. For example, based on the total weight of the coating composition, the amount of the surface-modified filler can be 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight or 60% by weight, or within a range composed of any of the above values.

[0072] In some embodiments, the coating composition described herein can be a two-component coating composition. In addition to the resin component containing polyaspartate and filler, the two-component coating composition can also have a curing agent component containing at least one polyisocyanate. Such a two-component coating composition still maintains a relatively fast reaction rate and can achieve baking-free and rapid drying at room temperature.

[0073] Coating compositions containing amino- and / or hydroxyl-functional resins preferably use isocyanates and isocyanurates as curing agents. By way of example, polyisocyanate curing agents can be aliphatic, cycloaliphatic and aromatic polyisocyanates, such as trimethylene diisocyanate, 1,2-propylene diisocyanate, tetramethylene diisocyanate, 2,3-butylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,2-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4-methyl-1,3-cyclohexylene diisocyanate, meta- and para-phenylene diisocyanate, 1,3- and 1,4-bis(isocyanatomethyl)benzene, 1,5-dimethyl-2,4-bis(isocyanatomethyl)benzene, 1,3,5-triisocyanatobenzene, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,4,6-toluene triisocyanate, α,α,α′,α′-tetramethyl-o-, m- and p-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyl diisocyanate, 3,3′-dichloro-4,4′-diphenyl diisocyanate, naphthalene-1,5-diisocyanate, isophorone diisocyanate, trans-vinylene diisocyanate, and mixtures of the above polyisocyanates.

[0074] In some embodiments, at least one polyisocyanate includes hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMDI), dicyclohexylmethane-4,4'-diisocyanate (HMDI), toluene diisocyanate (TDI), xylylene diisocyanate (XDI), tetramethyl-m-xylene diisocyanate (TMXDI), hexahydrotoluene diisocyanate (HTDI), its dimer or trimer, its derivatives or any combination thereof, preferably including hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) or a combination thereof.

[0075] In some exemplary two-component coating compositions, the amount of the curing agent component can be adjusted according to the amount of the resin component, particularly the amount of the resin component containing amino and / or hydroxyl functional resins, based on the experience of those skilled in the art. In some embodiments, the weight ratio of the resin component to the curing agent component can be in the range of 100:5 to 100:35, more preferably in the range of 100:10 to 100:30. For example, the weight ratio of the resin component to the curing agent component can be 100:15, 100:23 or other weight ratios of the resin component to the curing agent component commonly used in the art.

[0076] In some embodiments, the solids content of the coating compositions described herein is 80 to 98% by weight, more preferably 82 - 96% by weight, even more preferably 85 - 95% by weight. For example, the solids content of the coating composition can be 80% by weight, 82% by weight, 84% by weight, 85% by weight, 86% by weight, 87% by weight, 88% by weight, 89% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight or 98% by weight, or in a range composed of any of the above values.

[0077] In some embodiments, the coating composition is substantially free of texture aids. The inventors have found that texture aids (such as in acrylic resins) commonly added in the art to obtain a texture effect are not widely applicable to all coating compositions, and the obtained texture effect is also unstable. Even, the inventors have found that in some coating compositions with a relatively high system viscosity, adding texture aids is difficult to change the surface tension and cannot significantly increase the texture effect as in the acrylic resin system. Moreover, different from the action mode of texture aids, the coating compositions described herein can still obtain a good texture effect in the case of being substantially free of texture aids.

[0078] In an embodiment according to the present application, the carrier is optional in the formulation of the coating composition. In some embodiments, the coating composition is substantially free of the carrier to obtain a coating composition with ultra-low VOC. In some embodiments, the coating composition may contain an organic solvent as the carrier to further adjust the viscosity of the coating composition. The addition of the organic solvent can increase the evaporation rate of the coating composition and accelerate the formation of the paint film. Examples of the organic solvent include, but are not limited to, ketones (such as acetone, methyl isopropyl ketone, methyl isobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), aromatic hydrocarbons (toluene, xylene, etc.), aliphatic hydrocarbons (cyclopentane, cyclohexane, etc.) or any combination thereof.

[0079] In some embodiments, if present, the carrier may, for example, account for about 3-15% by weight, more preferably about 5-10% by weight, of the total weight of the coating composition or the resin component (when in a two-component coating composition). For example, the carrier may, for example, account for about 5% by weight, about 6% by weight, about 7% by weight, about 8% by weight, about 9% by weight, about 10% by weight of the total weight of the coating composition or the resin component (when in a two-component coating composition), or within a range composed of any of the above values. Generally, the desired amount of the carrier is usually selected empirically according to the film-forming performance of the paint film.

[0080] In some embodiments, the coating composition may optionally further contain common additional additives. Suitable additional additives may include fillers different from the surface-modified fillers described above (such as talc, wollastonite), dispersants, defoamers, leveling agents, corrosion inhibitors, adhesion promoters, film-forming aids, anti-sagging agents or any combination thereof.

[0081] The content of each of the above optional components is sufficient to achieve its intended purpose, but preferably, such content does not adversely affect the coating composition or the coating obtained therefrom. In some embodiments, the total amount of the additional additives is in the range of about 0% to about 65% by weight, preferably in the range of about 0.1% to about 60% by weight, relative to the total weight of the coating composition or the resin component (when in a two-component coating composition). The respective amounts of the additional additives may be in the range of 0-10% by weight, or in the range of 0-5% by weight, such as 0% by weight, 0.5% by weight, 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, or within a range composed of any of the above values.

[0082] In a specific embodiment according to the present application, the coating composition contains or the resin component of the two-component coating composition contains, relative to the total weight of the coating composition or the total weight of the resin component,

[0083] 15 - 35% by weight, preferably 20 - 30% by weight of polyaspartate ester;

[0084] 20 - 60% by weight, preferably 30 - 50% by weight of surface - modified filler with an oil absorption of 20 or lower;

[0085] 0 - 15% by weight of carrier, preferably 5 - 12% by weight of carrier;

[0086] 0 - 65% by weight of additional additives, preferably 0.1 - 60% by weight of additional additives.

[0087] The preparation of the coating composition can be achieved by any suitable mixing method well - known to those of ordinary skill in the art. For example, the coating composition can be made as follows: Add polyaspartate ester, surface - modified filler, carrier (if any), and additional additives (if any) into a container, and then stir the resulting mixture evenly to form the coating composition or resin component.

[0088] The two - component coating composition thus formed can be used as a coating in the general industrial field, such as for topcoating machine tools, forklifts, safes, etc. The fast - drying, bake - free characteristics and texture described herein are highly desirable for the above - mentioned application scenarios.

[0089] Moreover, the coating composition described herein has completed line tests on the production line and can be mass - produced, receiving favorable comments from customers with very advantageous cost and performance advantages.

[0090] The coating composition described herein can be applied using various methods familiar to those skilled in the art, including spraying (e.g., air - assisted, airless, or electrostatic spraying), brushing, roll coating, flood coating, and dipping. In some embodiments, the coating composition is applied by spraying. It can be cured by allowing the applied coating to air - dry or by accelerating curing using various drying devices familiar to those skilled in the art (e.g., oven). Preferably, the coating composition described herein can dry quickly without baking, while obtaining good texture effects and low VOC emissions. The coating composition described herein is very suitable for construction.

[0091] In some embodiments, the coating composition described herein has a VOC content not exceeding 200 g / L as determined by GB / T23985, preferably not exceeding 180 g / L. For example, the VOC content of the coating composition described herein as determined by GB / T23985 is 100 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, 160 g / L, 180 g / L, or 200 g / L, or within a range composed of any of the above values.

[0092] As described above, the inventors of the present application have surprisingly found that the coating compositions or two-component coating compositions described herein have the advantages of low VOC emissions, fast drying at room temperature, and suitability for construction, and are particularly suitable for use in the general industrial field.

[0093] Coated article

[0094] A second aspect of the present application provides a coated article, comprising: a substrate having at least one surface; and a coating composition or a cured coating thereof directly or indirectly coated on at least a part of the at least one surface of the substrate, wherein the coating composition is the coating composition described herein.

[0095] As the substrate for manufacturing the article of the present invention, any suitable substrate known in the art can be used. By way of example, the substrate is selected from metals, woods, wood composites, papers, plastics, fabrics, ceramics, cement materials, or any combination thereof.

[0096] In some embodiments, the substrate is preferably a metal substrate. By way of example, the metal substrate is selected from one or more of steel, iron, aluminum, zinc, and their alloys.

[0097] According to the present application, the article can be prepared, for example, by the following steps: (1) providing a sanded substrate; (2) using a coating and curing process to sequentially coat and form one or more two-component coating compositions of the present application on the substrate to provide a protective property for the metal substrate.

[0098] According to the present application, the article thus obtained is optionally used in the following end applications, including, but not limited to: refrigerated containers and non-refrigerated transport containers (such as dry cargo containers) including other suppliers or manufacturers well-known to those of ordinary skill in the art; chassis, trailers (including semi-trailers), rail vehicles, truck bodies, ships, bridges, building skeletons. Additional uses include metal corners, channels, beams (such as I-beams), pipes, tubes, sheets, or other components that can be welded into these or other metal parts. The article is particularly suitable for use in general industrial fields such as machine tools, forklifts, and safes.

[0099] The following examples more specifically describe the content disclosed in the present application. These examples are for illustrative purposes only, as various modifications and variations within the scope of the present application are apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight, and all reagents used in the examples are commercially available and can be used directly without further treatment.

[0100] Example

[0101] Test method

[0102] Oil absorption

[0103] The oil absorption of the filler is measured in accordance with GB / T 5211.15-2014.

[0104] VOC emission

[0105] In accordance with GB / T 23985-2009, the volatile organic compound (VOC) content of the coating composition is measured by the difference method.

[0106] Finger pressure drying

[0107] At 25°C, after mixing the components of the coating composition, it is coated onto the substrate at DFT = 50 - 60 μm under RH 50 - 60%, and the time when the thumb is pressed firmly on the paint surface without leaving a finger pressure mark or damaging the coating surface.

[0108] Texture effect

[0109] After mixing the components of the coating material, it is coated on the test panel and cured. Then, it is compared visually with the reference color plate, and the texture effect morphology focusing on the horizontal direction of the coating and the three-dimensional effect morphology focusing on the vertical direction are evaluated. The result is evaluated on a scale of 1 - 5, where 5 indicates that the coating exhibits an obvious three-dimensional effect morphology, and 1 indicates that no or almost no three-dimensional effect morphology is observed on the coating surface.

[0110] Materials and their properties

[0111] Table 1

[0112]

[0113] Coating composition

[0114] In Examples 1 - 7 (Ex.1 to Ex.7) and Comparative Examples 1 - 8 (CE.1 to CE.8), as shown in Table 2, the components in the resin component (Component A) are mixed, and then it is mixed with the curing agent component (Component B) at a weight ratio of 5.5:1 to form a mixture. A mixture of 90 wt% polyisocyanate curing agent and solvent is used as the curing agent component (Component B). According to the above test section, the properties of the obtained coating composition or cured coating are measured. The obtained results are shown in Table 2 and the attached drawings below.

[0115]

[0116] As can be seen from the results described in Table 2 above, the coating composition of the present application has the advantages of low VOC emissions, quick drying at room temperature, and suitability for construction. Moreover, the coating composition of the present application can obtain a good texture effect, even in the absence of a texture aid.

[0117] Although the present application is described with reference to a large number of embodiments and examples, those of ordinary skill in the art will recognize that other embodiments can be designed based on the disclosure of the present application. It is easy for those skilled in the art to see that changes can be made to the present application without departing from the principles disclosed in the foregoing description. For example, without departing from the principles disclosed in the foregoing description, a technical solution obtained by combining a plurality of features or preferred modes described herein should be understood to be within the scope of the content described herein. Such changes are considered to be included in the claims unless the claims specify otherwise. Accordingly, the embodiments detailed herein are exemplary only and are not intended to limit the scope of the present application, which is the full scope of the appended claims and any and all equivalents thereof.

Claims

1. A coating composition, comprising: at least one polyaspartate ester, and a surface-modified filler having an oil absorption of 20 g / 100 g or less, wherein the viscosity of the coating composition does not exceed 17000 cps at 25 °C.

2. The coating composition according to claim 1, wherein, The at least one polyaspartate ester has at least two secondary amino groups.

3. The coating composition according to claim 1 or 2, wherein the at least one polyaspartate ester has one or more of the following characteristics: a number average molecular weight between 300 g / mol and 1200 g / mol, an amine equivalent between 150 g / eq and 450 g / eq, and a viscosity of 300 - 3000 cps.

4. The coating composition according to any one of claims 1 to 3, wherein, The at least one polyaspartate ester has a structure represented by the following general formula (I): wherein X represents an aliphatic hydrocarbon group inert to isocyanate groups at temperatures up to 100 °C; R1 and R2 each independently represent an organic group inert to isocyanate groups at temperatures up to 100 °C; R3 and R4 each independently represent hydrogen and an organic group inert to isocyanate groups at temperatures up to 100 °C; and n is an integer from 2 to 6.

5. The coating composition according to any one of claims 1 to 4, wherein, Based on the total weight of the coating composition, the amount of the at least one polyaspartate ester is 15 - 35 wt%.

6. The coating composition according to any one of claims 1 to 5, wherein, The surface-modified filler has a surface-modified part and a core part, and the core part is one or more of precipitated barium sulfate, barite powder, heavy calcium carbonate, rutile titanium dioxide, talc powder with a mesh size of 350 or coarser, and quartz powder with a mesh size of 350 or coarser.

7. The coating composition according to any one of claims 1 to 6, wherein The surface-modified filler has one or more of the following characteristics: D50 is in the range of 0.8 - 2 μm, D97 is in the range of 3 - 10 μm, The specific gravity is within 2 - 6 g / cm 3 range. The bulk density is in the range of 0.3 - 5 g / cm 3 and The compaction density is in the range of 0.5 - 6 g / cm 3 within the range.

8. The coating composition according to any one of claims 1 to 7, wherein the surface-modified filler is surface-treated by compound coating with one or more of a silane coupling agent, silica-alumina, and a high molecular polymer.

9. The coating composition according to claim 8, wherein, The silane coupling agent has Y(CH2) m SiX3, where m = 0, 1, 2 or 3, Y is or contains one or more groups of alkenyl, (meth)acryloyloxy, aminoalkyl, isocyanatoalkyl, epoxyalkyl, ureidoalkyl, and Each X is independently selected from methyl, ethyl, halogen, methoxy, ethoxy, propoxy, isopropoxy, or trimethylsiloxy, provided that at least one X is methoxy, ethoxy, propoxy, isopropoxy, or trimethylsiloxy.

10. The coating composition according to any one of claims 8 to 9, wherein, The molecular weight of the silane coupling agent is 100 - 800 daltons.

11. The coating composition according to any one of claims 8 to 10, wherein, The silane coupling agent is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, (meth)acryloyloxypropyltrimethoxysilane, (meth)acryloyloxypropyltriethoxysilane, (meth)acryloyloxypropylmethyldimethoxysilane, (meth)acryloyloxypropylmethyldiethoxysilane, (meth)acryloyloxypropyltris(trimethylsiloxy)silane, γ-aminopropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, and diethoxymethyl[(3-oxiranylmethoxy)propyl]silane.

12. The coating composition according to any one of claims 1 to 11, wherein, Based on the total weight of the coating composition, the amount of the surface-modified filler is 20 - 60 wt%.

13. The coating composition according to any one of claims 1 to 12, wherein, The coating composition is a two-component coating composition, and the two-component coating composition has a curing agent component containing at least one polyisocyanate.

14. The coating composition according to claim 13, wherein, The at least one polyisocyanate includes hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), trimethylhexane diisocyanate (TMDI), dicyclohexylmethane-4,4'-diisocyanate (HMDI), toluene diisocyanate (TDI), xylylene diisocyanate (XDI), tetramethylene-m-xylene diisocyanate (TMXDI), hexahydrotoluene diisocyanate (HTDI), its dimer or trimer, its derivative or any combination thereof, preferably including hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) or a combination thereof.

15. The coating composition according to any one of claims 1 to 14, wherein The solid content of the coating composition is 80 to 98% by weight.

16. The coating composition according to any one of claims 1 to 15, wherein, The coating composition is substantially free of texture aids.

17. A coated article comprising a substrate having at least one surface; and a coating composition or its cured coating directly or indirectly coated on at least part of the at least one surface of the substrate, Among them, wherein the coating composition is the coating composition according to any one of claims 1-16.

18. The coated article according to claim 17, wherein, The substrate is selected from metals, woods, wood composites, papers, plastics, fabrics, ceramics, cement materials or any combination thereof.

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