One-component coating composition and coated article

Abstract

The invention relates to a one-component coating composition and a coated article. The one-component coating composition comprises at least one acrylic monomer, at least one epoxy resin, at least one silane coupling agent, and at least one nonionic reactive epoxy resin emulsifier. The single-component coating composition disclosed by the invention basically does not contain a phosphorus emulsifier, has good storage stability, is relatively simple to construct, and can obtain an excellent acid and alkali resistant coating. The single-component coating composition disclosed by the invention is very suitable for being applied to various substrates, and is particularly suitable for being directly applied to metal substrates.

Description

Technical Field

[0001] The present invention relates to a one-component coating composition and a coated product, and more particularly to a one-component coating composition which is substantially free of a phosphorus-based emulsifier, has good storage stability and can obtain an excellent acid- and alkali-resistant coating. Background Art

[0002] Various coating compositions have been designed in the coating industry for coating various substrates. In applications requiring acid- and alkali-resistant coatings, and more desirably salt spray-resistant coatings, two-component coating compositions (e.g., polyurethane) containing phosphorus-based emulsifiers are currently mostly used on the market. However, phosphorus is the "culprit" that causes eutrophication and algal blooms in water bodies, causing a significant reduction in dissolved oxygen in water in water environments such as lakes and rivers, causing aquatic animals such as fish and plankton to die due to lack of oxygen, resulting in the destruction of the water environment and ecological imbalance. Therefore, more and more countries and regions have issued "phosphorus ban" or "phosphorus limit" regulations.

[0003] Moreover, two-component coating compositions use resins and curing agents with higher costs, and storage conditions and construction processes all need strict control, otherwise easily cause problems such as coating failure, short pot life, unstable film performance. For example, the construction process of two-component coatings is complicated, requiring that two components be deployed on-site with a stable blending ratio as required. If an incorrect blending ratio is used by chance, the coating may show premature rusting, blistering or other unqualified types of coatings. This unqualified usually results in expensive removal of unqualified coatings and application of new coatings. Therefore, the performance of the final coating obtained by two-component coatings is easily affected by factors such as deployment process, technical personnel proficiency. In addition, curing agents (such as isocyanate curing agents) often have more active chemical properties and structural fragments that are toxic to the human body. Summary of the invention

[0004] In view of the above, the coating industry needs a coating composition that is substantially free of phosphorus-based emulsifiers (e.g., phosphate emulsifiers and emulsifiers derived from phosphate esters), has good storage stability, is relatively simple to construct, and can obtain an excellent acid- and alkali-resistant coating.

[0005] After intensive research, the inventors of the present application discovered that the above objectives can be achieved by using the one-component coating composition provided herein.

[0006] The first aspect of the present application provides a one-component coating composition comprising:

[0007] at least one acrylic monomer,

[0008] at least one epoxy resin,

[0009] at least one silane coupling agent, and

[0010] At least one nonionic reactive epoxy resin emulsifier.

[0011] The inventors have found that by adopting the above-mentioned one-component coating composition of a specific composition, it is possible to exhibit good storage stability and provide an excellent water-resistant and acid-resistant coating without using a phosphorus-based emulsifier and a curing agent. This is very surprising because, unlike mainstream coatings containing phosphorus-based emulsifiers, the one-component coating composition of the present application can provide an excellent salt spray-resistant coating without using a phosphorus-based emulsifier, which complies with the relevant provisions of "phosphorus ban" or "phosphorus restriction". It is particularly surprising that, in addition to storage stability, water resistance, acid and alkali resistance, some preferred embodiments of the present application can obtain particularly excellent salt spray resistance, for example, a coating that does not blister for at least 500 hours in a salt spray test at 35°C can be provided.

[0012] It is also surprising that according to the common knowledge in the art, epoxy resin must be cross-linked with a curing agent to become an excellent coating. However, the coating composition of the present application adopts a single component form, and a curing agent may not be used, while also providing a coating with excellent properties.

[0013] Moreover, the inventors of the present application have conducted a large number of experimental studies and surprisingly found that a storage-stable coating composition can be obtained by combining a nonionic reactive epoxy resin emulsifier, a water-based epoxy resin, an acrylic monomer and a silane coupling agent. The acrylic monomer and the epoxy resin having a reactive group contained in the one-component coating composition of the present application hardly participate in the reaction before curing, so that the one-component coating composition of the present application can be stable at room temperature for at least 180 days. This excellent storage stability is very surprising and exceeds the expectations of those skilled in the art.

[0014] The second aspect of the present application provides a coated product, the product comprising a substrate having at least one main surface; and a coating directly or indirectly coated on at least part of the main surface of the substrate, wherein the coating is formed by the above-mentioned one-component coating composition according to the present invention. Preferably, the substrate is selected from metal, wood, wood composite, paper, plastic, fabric, ceramic, cement material or any combination thereof.

[0015] The inventors of the present invention surprisingly found that, particularly preferably, the coating in the present application can be free of blistering in a salt spray test at 35° C. for at least 500 hours.

[0016] The details of one or more embodiments of the present invention are set forth in the following description. Other features, objectives and advantages of the present invention will become apparent from the contents described in the application documents. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings involved in the embodiments of the present application. Obviously, the drawings described below are only exemplary descriptions of some embodiments of the present application and are therefore non-restrictive. For those of ordinary skill in the art, other drawings can also be obtained based on the drawings without creative work.

[0018] Figure 1 These are the results of water resistance tests of cured coatings obtained according to one embodiment of the present application (Example 1, left figure) and according to Comparative Example 2 (right figure).

[0019] Figure 2 The results of the salt spray resistance test at 35° C. for 500 hours of the cured coatings obtained on tin-plated iron according to one embodiment of the present application (Example 1, left figure) and according to Comparative Example 2 (right figure) are shown.

[0020] Figure 3 The results of a salt spray resistance test at 35° C. for 500 hours on a cured coating obtained on a cold-rolled steel plate according to one embodiment of the present application (Example 1, left figure) and Comparative Example 2 (right figure) respectively. DETAILED DESCRIPTION

[0021] definition

[0022] As used herein, "a, an", "the", "at least one" and "one or more" and the absence of quantifiers are used interchangeably. Thus, for example, a component containing "an" additive can be interpreted as meaning that the component contains "one or more" additives.

[0023] Where a composition is described as comprising or including specific components, it is contemplated that optional components not contemplated by the present invention are not excluded from the composition, and that the composition may consist of or be composed of the contemplated components; or where a method is described as comprising or including specific process steps, it is contemplated that optional process steps not contemplated by the present invention are not excluded from the method, and that the method may consist of or be composed of the contemplated process steps.

[0024] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unambiguous range; and any lower limit can be combined with other lower limits to form an unambiguous range, and any upper limit can be combined with any other upper limit to form an unambiguous range. In addition, although not explicitly stated, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unambiguous range.

[0025] As used herein, the term "substantially free" with respect to a component of a composition means that in the formulation, the component is not actively or intentionally added to the composition, but the component may be present as an impurity in an amount of less than about 2 weight % relative to the total weight of the composition; preferably, the component may be present in an amount of less than about 1 weight %, more preferably less than 0.1 weight %, and even more preferably less than 0.05 weight % relative to the total weight of the composition.

[0026] When used in this article, the term "direct-to-metal" (DTM) means: the coating composition is applied directly to the surface of a metal substrate, wherein the substrate has not been previously coated with a primer, pretreatment or other coating. When used in this article, the term "pretreatment" refers to any organic coating applied to the surface of the substrate before applying a paint or other protective coating, but does not include standard procedures and / or materials for cleaning or preparing the surface, such as sandblasting (blasting) and the like. Therefore, a DTM coating that is not applied with a pretreatment can be applied to a surface cleaned by sandblasting, etc. Standard procedures and / or materials for cleaning or preparing a surface are not necessary, i.e., optional. Unless otherwise stated, a DTM coating does not require a previous pretreatment or primer coating, or a subsequent topcoat coating.

[0027] In this document, "coating" and "paint film" have the same meaning, and both are formed after the coating composition is applied and cured.

[0028] In the context of the present application, the term "two-component coating composition" refers to a coating composition consisting of two or more separately stored components, which components are mixed together when used and can be dried and cured within an acceptable period of time to form a coating having the desired mechanical properties (e.g. hardness).

[0029] In the context of the present application, the term "one-component coating composition" means that, unlike a "two-component coating composition", the coating composition is provided in the form of a one-component system, wherein all components are combined and stored in a single container.

[0030] In the context of this application, the term "shelf stable" and similar terms refer to coating compositions that do not gel or solidify over extended periods of time (eg, greater than 5 months under ambient conditions) but remain liquid and at a viscosity suitable for applying the coating composition.

[0031] In the context of the present application, the term "nonionic reactive epoxy resin emulsifier" refers to an adduct formed by the addition of an epoxy resin (e.g., an epoxy resin having an epoxy equivalent of 400 g / eq to 2500 g / eq) and a nonionic surfactant. In one embodiment of the present invention, the nonionic reactive epoxy resin emulsifier is an adduct formed by the addition of an epoxy resin and cardanol polyoxyethylene ether.

[0032] When used with respect to "epoxy resin" and / or "nonionic reactive epoxy resin emulsifier", the term "epoxy equivalent" refers to the mass of the relevant material containing 1 mol of epoxy groups. Generally, the lower the epoxy equivalent, the more epoxy groups contained in the relevant material and the higher the reactivity. In embodiments of the present invention, the epoxy equivalent of the epoxy resin and the nonionic reactive epoxy resin emulsifier is usually provided by the supplier and can be determined using ASTM D1652.

[0033] The term "(meth)" refers to compounds containing methyl substitutions in the class of compounds modified by the term. For example, the term (meth)acrylic acid refers to acrylic acid and methacrylic acid. Similar usage also applies to other derivatives of acrylic acid and methacrylic acid, such as (meth)acrylamide, (meth)acrolein, and the like.

[0034] As used herein, the term "paint" refers to a coating composition that can be applied to a metal substrate or other coating and dried, crosslinked or otherwise hardened to form a non-tacky, continuous film having sufficient adhesion to the surface of the substrate or other coating.

[0035] When appearing in this description and claims, the terms "comprises" and "includes" and variations thereof do not have a limiting meaning.

[0036] The terms "preferred" and "preferably" refer to embodiments of the present invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. In addition, the recitation of one or more preferred embodiments does not mean that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present invention.

[0037] The first aspect of the present application provides a one-component coating composition comprising:

[0038] at least one acrylic monomer,

[0039] at least one epoxy resin,

[0040] at least one silane coupling agent, and

[0041] At least one nonionic reactive epoxy resin emulsifier.

[0042] The monomer components can be roughly classified as "hard monomers" or "soft monomers" based on the glass transition temperature (Tg) of the homopolymer prepared from the monomers. The glass transition temperature (Tg) of the resulting copolymer, and thus the properties of the paint film, can be adjusted by varying the relative amounts of "hard" monomers (higher Tg) and "soft" monomers (lower Tg). Tg can be determined by differential scanning calorimetry (DSC).

[0043] Examples of hard monomers include styrene, isobornyl acrylate, isobornyl methacrylate, methyl methacrylate, ethyl methacrylate, and cyclohexyl methacrylate. Preferably, the hard monomer is selected from one or more of styrene, methyl methacrylate, ethyl methacrylate, and cyclohexyl methacrylate.

[0044] Examples of soft monomers include butyl acrylate, methyl acrylate, ethyl acrylate, isooctyl acrylate, lauryl acrylate, isobutyl acrylate, butyl methacrylate, isobutyl methacrylate and hexyl methacrylate. Preferably, the soft monomer is selected from one or more of butyl acrylate, methyl acrylate, ethyl acrylate and isooctyl acrylate.

[0045] Preferably, the mass ratio of the hard monomer to the soft monomer is 1:5 to 8:1, preferably 1:3 to 3:1. For example, the mass ratio of the hard monomer to the soft monomer may be about 1:4, 1:3, 1:2, 1:1.5, 1:1.2, 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1, 2.5:1, 3:1, 4:1, 5:1 or 8:1. In some preferred embodiments, the mass ratio of the hard monomer to the soft monomer may be about 1:2 to 2.7:1, more preferably 1:1.5 to 2.5:1, and particularly preferably 1:1 to 2:1. Other ranges formed by the above values, upper and lower limits of the above ranges may also be used.

[0046] In some embodiments, suitable acrylic monomers are selected from (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxymethyl (meth) acrylic acid amide, one or more. Preferably, the acrylic monomers include isooctyl acrylate. More preferably, the amount of isooctyl acrylate is 20% to 60% by weight relative to the total weight of the acrylic monomers, such as at least 25% by weight, at least 28% by weight, 30% by weight, 33% by weight, 34% by weight, 35% by weight, 38% by weight, 40% by weight, no more than 45% by weight, no more than 50% by weight, no more than 55% by weight. More preferably, the amount of isooctyl acrylate is 30% to 40% by weight relative to the total weight of the acrylic monomers, more preferably 33% to 38% by weight. The inventors have found that when isooctyl acrylate is used in the above dosage range, the comprehensive properties of the cured coating (such as water resistance, salt spray resistance, acid and alkali resistance, etc.) are further improved.

[0047] In some embodiments, the amount of acrylic monomer is 5-60 wt %, preferably 10-55 wt %, based on the total weight of the one-component coating composition. For example, the amount of acrylic monomer can be 8 wt %, 10 wt %, 15 wt %, 20 wt %, 25 wt %, 29 wt %, 30 wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt % or 55 wt %, based on the total weight of the one-component coating composition. Other ranges formed by the above values, upper and lower limits of the above ranges can also be used.

[0048] The inventors have found that by adjusting the amount and relative weight ratio of each monomer within the range described above, the comprehensive properties of the cured coating (eg, including water resistance, salt spray resistance, acid and alkali resistance, etc.) can be further improved.

[0049] Preferably, the one-component coating composition of the present application is an aqueous coating composition. This means that the one-component coating composition of the present application has very low VOC and is an environmentally friendly coating. In some embodiments, based on the gross weight of the one-component coating composition, the one-component coating composition of the present application comprises 30 wt % or more of water, more preferably 40 wt % or more of deionized water. In some embodiments, the one-component coating composition of the present application comprises 80 wt % or less of water, more preferably 70 wt % or less of deionized water. For example, based on the gross weight of the one-component coating composition, the amount of deionized water can be 35 wt %, 40 wt %, 45 wt %, 50 wt %, 55 wt %, 60 wt %, 65 wt %, 70 wt %, 75 wt % or 80 wt %. Other ranges formed by the above numerical value, the upper limit and the lower limit of the above range can also be adopted.

[0050] In addition to acrylic monomers, the one-component coating composition of the present application may also include epoxy resins. The combination of this acrylic monomer and epoxy resin can make the paint film have the advantages of both acrylic resins and epoxy resins, maintaining excellent salt spray resistance. The term "epoxy resin" refers to a polymer or oligomer containing two or more epoxy groups in each molecule. Preferably, each molecule in the epoxy resin may contain up to four epoxy groups. Preferably, each molecule in the epoxy resin may contain two or three epoxy groups. This resin component is used as a binder to provide adhesion of the coating to the substrate, and to keep the components in the one-component coating composition together and give the paint film a certain cohesive strength.

[0051] In some embodiments, epoxy resin can have an epoxy equivalent that varies in a wide range, wherein epoxy equivalent refers to the mass of the epoxy resin containing 1mol epoxy group. In this article, epoxy resin includes an epoxy equivalent between 200-2000g / eq, preferably between 220-1500g / eq, more preferably between 250-1000g / eq. For example, the epoxy equivalent of epoxy resin can be about 200g / eq, 220g / eq, 250g / eq, 280g / eq, 300g / eq, 350g / eq, 400g / eq, 500g / eq, 600g / eq, 700g / eq, 800g / eq, 1000g / eq, 1200g / eq, 1500g / eq. Other scopes formed by the upper and lower limits of the above numerical value, the above range can also be adopted.

[0052] Suitable epoxy resins include, for example, diglycidyl ethers of polyhydric phenols, such as diglycidyl ether of resorcinol, diglycidyl ether of catechol, diglycidyl ether of hydroquinone, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, diglycidyl ether of bisphenol S, diglycidyl ether of tetramethyl bisphenol; diglycidyl ethers of polyhydric alcohols, such as diglycidyl ethers of aliphatic diols and diglycidyl ethers of polyether diols, such as C 2-24 diglycidyl ethers of alkylene glycols, diglycidyl ethers of poly(ethylene oxide) glycols, or diglycidyl ethers of poly(propylene oxide) glycols; polyglycidyl ethers of phenolic resins, such as polyglycidyl ethers of phenol-formaldehyde resins, polyglycidyl ethers of alkyl-substituted phenol-formaldehyde resins, polyglycidyl ethers of phenol-hydroxybenzaldehyde resins, or polyglycidyl ethers of cresol-hydroxybenzaldehyde resins; or combinations thereof.

[0053] According to certain embodiments of the present invention, the epoxy resin is a diglycidyl ether of a polyphenol, and particularly preferably has the following structural formula (I):

[0054]

[0055] wherein D represents -S-, -SS-, -SO-, -SO2-, -CO2-, -CO-, -O- or a divalent alkyl group having 1 to 10, preferably 1 to 5, more preferably 1 to 3 carbon atoms, such as -CH2- or -C(CH3)2-;

[0056] Each Y is independently a halogen, such as F, Cl, Br or I, or an optionally substituted monovalent C1-C 10 a hydrocarbon group such as optionally substituted methyl, ethyl, vinyl, propyl, allyl or butyl;

[0057] each m is independently 0, 1, 2, 3 or 4; and

[0058] n is an integer from 0 to 4, such as 0, 1, 2, 3 or 4.

[0059] More preferably, the epoxy resin is a bisphenol A epoxy resin, a bisphenol S epoxy resin or a bisphenol F epoxy resin having structural formula (I), wherein D represents -C(CH3)2-, -SO2- or -CH2-, respectively, m represents 0, and n is an integer from 0 to 4.

[0060] Most preferably, the epoxy resin is a bisphenol A type epoxy resin having structural formula (I), wherein each D represents -C(CH3)2-, m represents 0, and n is an integer from 0 to 4.

[0061] The epoxy resin disclosed above can be prepared, for example, using epichlorohydrin technology well known to those skilled in the art. Alternatively, as an example of epoxy resin, any suitable commercially available product can be used, such as solid epoxy resin NPES 901 purchased from Nan Ya.

[0062] In some embodiments according to the present invention, the epoxy resin may be present in liquid form. In other embodiments according to the present invention, the epoxy resin may also be present in solid form. The inventors have found that by using an epoxy resin in solid form, the comprehensive properties of the cured coating (for example, including water resistance, salt spray resistance, acid and alkali resistance, gloss, hardness, etc.) can be further improved. Therefore, preferably, the epoxy resin itself is present in solid form at normal temperature and pressure.

[0063] In some embodiments of the present application, the total amount of epoxy resin is 2-60 wt %, preferably in the range of 3 wt % to 55 wt %, preferably in the range of 5 wt % to 50 wt %, more preferably in the range of 8 wt % to 45 wt %, and even more preferably in the range of 10 wt % to 20 wt %, relative to the total weight of the one-component coating composition. For example, the amount of epoxy resin can be about 10 wt %, 12 wt %, 15 wt %, 18 wt %, 20 wt %, 22 wt %, 25 wt %, 28 wt %, 30 wt %, 35 wt %, 40 wt % or 45 wt % relative to the total weight of the one-component coating composition. Other ranges formed by the above values, upper and lower limits of the above ranges can also be used.

[0064] In some embodiments, the amount of epoxy resin can be 2 wt % to 50 wt %, such as 5 wt %, 10 wt %, 15 wt %, 20 wt %, 25 wt %, 30 wt %, 35 wt %, 40 wt %, 45 wt %, relative to the total weight of epoxy resin and acrylic monomer. In some embodiments, the weight ratio of acrylic monomer to epoxy resin can be in the range of 5:1 to 1:5, preferably in the range of 4:1 to 1:3, more preferably in the range of 3:1 to 1:1, such as 2.9:1, 2.5:1, 2:1 or 1.5:1.

[0065] In some embodiments, the silane coupling agent has Y(CH2) n SiX3, wherein n=0, 1, 2 or 3, Y is or contains one or more of alkenyl, (meth)acryloyloxy, aminoalkyl, isocyanatealkyl, epoxyalkyl, ureaalkyl, and each X is independently selected from methyl, ethyl, 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 vinyl trimethoxy silane, vinyl triethoxy silane, vinyl triisopropoxy silane, (meth) acryloxy propyl trimethoxy silane, (meth) acryloxy propyl triethoxy silane, (meth) acryloxy propyl methyl dimethoxy silane, (meth) acryloxy propyl methyl diethoxy silane, (meth) acryloxy propyl tri (trimethylsiloxy) silane, γ-aminopropyl trimethoxy silane, tris (3-trimethoxysilyl propyl) isocyanurate, γ-isocyanate propyl trimethoxy silane, γ-isocyanate propyl triethoxy silane, 3-glycidyl ether oxypropyl triethoxy silane, diethoxy methyl [(3-oxirane methyloxy) propyl] silane in one or more. Preferably, the silane coupling agent is selected from one or more of vinyl triisopropoxysilane, acryloxypropyl triethoxysilane, γ-methacryloxypropyl triethoxysilane, γ-isocyanate propyl triethoxysilane, and tris(3-trimethoxysilylpropyl) isocyanurate.

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

[0068] This combination of double bonds and large steric hindrance can not only make the silane coupling agent react with the film-forming resin and monomer during the film-forming process, but also help to improve the adhesion between the resin and the substrate. Moreover, for DTM applications, the silane coupling agent in this article is conducive to obtaining better adhesion on metal substrates with low surface treatment (such as no polishing) and improving the performance of metal substrates in salt spray resistance tests.

[0069] In addition to the acrylic monomers, epoxy resins and silane coupling agents mentioned above, the one-component coating composition of the present application also contains a nonionic reactive epoxy resin emulsifier. The nonionic reactive epoxy resin emulsifier is an adduct formed by the addition of an epoxy resin (e.g., an epoxy resin with an epoxy equivalent of 400 g / eq to 2500 g / eq) and a nonionic surfactant, which can be used as an emulsifier for the epoxy resin and has appropriate reactivity and can react with the curing agent, thereby reducing or even avoiding the risk of migration from the coating.

[0070] In some embodiments, the at least one nonionic reactive epoxy resin emulsifier is derived from one or more of butyl glycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, cardanol polyoxyethylene ether, and cardanol glycidyl ether.

[0071] Preferably, the nonionic reactive epoxy resin emulsifier is derived from cardanol polyoxyethylene ether. As an exemplary illustration, the cardanol polyoxyethylene ether has a structure shown in the following formula (I):

[0072]

[0073] Here, n is in the range of 10-60.

[0074] The inventors of the present application have found that the cardanol polyoxyethylene ether used to form the nonionic reactive epoxy resin emulsifier has a hydrophilic segment consisting of 10-60 EO / PO units, and the hydrophobic segment has a large conjugated group, which increases the interaction between molecules. It is precisely for the above reasons that the emulsifier can emulsify epoxy resin well, and even emulsify solid epoxy resin well. Therefore, the water-based resin emulsion formed by its preparation has the characteristics of suitable particle size and uniform particle size distribution.

[0075] In one embodiment according to the present invention, the nonionic reactive epoxy resin emulsifier has an epoxy equivalent weight ranging from 10,000 g / eq to 40,000 g / eq, the epoxy equivalent weight being determined according to ASTM D1652.

[0076] In one embodiment of the present invention, the nonionic reactive epoxy resin emulsifier is in a solid form.

[0077] The nonionic reactive epoxy resin emulsifier can be prepared by those skilled in the art based on experience. Alternatively, the nonionic reactive epoxy resin emulsifier can use any suitable commercially available product as an example, such as the GF-40 brand nonionic reactive epoxy resin emulsifier from Jiangsu Haian Petrochemical.

[0078] In one embodiment according to the present invention, the amount of the at least one nonionic reactive epoxy resin emulsifier is in the range of 0.1 wt % to 10 wt % relative to the total weight of the one-component coating composition. For example, the amount of the at least one nonionic reactive epoxy resin emulsifier can be about 0.5 wt %, 1 wt %, 1.5 wt %, 2 wt %, 2.5 wt %, 3 wt %, 5 wt % or 8 wt relative to the total weight of the one-component coating composition. Preferably, the amount of the at least one nonionic reactive epoxy resin emulsifier can be 1.5 to 3 wt %. Other ranges formed by the above values, the upper and lower limits of the above ranges can also be used.

[0079] In one embodiment, the weight ratio of the at least one nonionic reactive epoxy resin emulsifier to the at least one epoxy resin is in the range of 1:20 to 1:1.2. Preferably, the weight ratio of the at least one nonionic reactive epoxy resin emulsifier to the at least one epoxy resin is in the range of 1:15 to 1:1.5, more preferably in the range of 1:10 to 1:2. For example, the weight ratio of the at least one nonionic reactive epoxy resin emulsifier to the at least one epoxy resin may be 1:12, 1:8, 1:6, 1:5, 1:4, 1:3, 1:2 or 1:1.8. Other ranges formed by the above values, upper and lower limits of the above ranges may also be used.

[0080] As an exemplary illustration, the above-mentioned one-component coating composition can be prepared by any method suitable for preparing an aqueous emulsion known to those skilled in the art using the above-mentioned epoxy resin, non-ionic reactive epoxy resin emulsifier and deionized water. However, in a preferred embodiment according to the present invention, the above-mentioned one-component coating composition is prepared in the following manner. Specifically, at a stirring speed of 1400-1600rpm, the at least one epoxy resin and the at least one non-ionic reactive epoxy resin emulsifier are melted and mixed; deionized water is slowly added until the inversion is reached, and the addition of deionized water is stopped and dispersed at a stirring speed of 1800-2000rpm; then deionized water is further added to form an emulsion of the one-component coating composition. The inventors of the present invention have found that the one-component coating composition prepared by the above-mentioned method has particularly excellent stability, including but not limited to high temperature stability and solvent stability. For example, the one-component coating composition formulated by the above method can be stored at a high temperature of 50°C for a period of 1 month or longer or be stable at room temperature for at least 180 days without demulsification and / or without demulsification in the presence of high concentrations of various organic solvents (including 30% of dipropylene glycol butyl ether (DPnB), dipropylene glycol methyl ether (DPM), propylene glycol propyl ether (PnP), ethylene glycol butyl ether (BCS), Texanol, ethanol), which was difficult to predict before the present application.

[0081] Preferably, the composition is substantially free of phosphorus-based emulsifiers, such as substantially free of phosphate-based emulsifiers.

[0082] In one embodiment of the present invention, the one-component coating composition has a solid content of 38-75 wt %, preferably 40-70 wt %, more preferably 45-65 wt %.

[0083] In one embodiment of the present invention, in the one-component coating composition, the epoxy resin has an epoxy equivalent weight of 900-1100 g / eq.

[0084] In one embodiment according to the present invention, the one-component coating composition comprises particles having a particle size of less than 30 micrometers.

[0085] In some embodiments, the one-component coating composition according to the present invention may further include pigments, fillers, aqueous media and / or additional additives.

[0086] In the embodiments of the present invention, "pigment and filler" is a general term for pigments and fillers.

[0087] According to the present invention, "filler" refers to any volume extender suitable for coating compositions, which may be inorganic, for example, in the form of particles. There are no particular restrictions on the shape of the particles, which may have any suitable shape. The average particle size of the filler may vary over a wide range, for example, in the range of about 10 nanometers to about 50 micrometers. Some fillers, in addition to acting as volume extenders, also impart one or more desired properties to the composition and / or the coating formed by the composition. For example, some fillers may improve chemical and / or physical properties, and may particularly improve the mechanical properties of the coating obtained by the composition. In this case, such fillers are also referred to as "reinforcing fillers". Suitable fillers may include, for example, silicates, sulfates, carbonates, and silicon dioxide. Suitable exemplary fillers include, for example, china clay, wollastonite, barite, calcium carbonate, diatomaceous earth, talcum powder, barium sulfate, magnesium aluminum silicate, silicon dioxide, and any combination thereof.

[0088] According to the present invention, "pigment" is a reagent for providing color and hue to the cured coating. Suitable pigments can include one or more or combinations thereof of iron oxide, carbon black, lead oxide, lead carbonate, zinc oxide, titanium oxide, deep sea blue, chrome green or chromium oxide. As a special pigment, "rust-proof pigment" also has the effect of preventing metal substrates from rusting, including but not limited to zinc phosphate, zinc molybdenum phosphate and aluminum tripolyphosphate. As an example of rust-proof pigment, any suitable commercially available product can be used, such as commercially available from HEUCOPHOS CAPP, HEUCOPHOS SAPP, HEUCOPHOS ZPA, etc. In some preferred embodiments of the present invention, the one-component coating composition comprises titanium oxide, carbon black, rust-proof pigment and combinations thereof.

[0089] According to certain embodiments of the present invention, the total amount of pigments and fillers can vary within a wide range, for example, the total amount thereof is in the range of about 5 wt % to about 65 wt %, preferably in the range of about 10 wt % to about 60 wt %, and more preferably in the range of about 10 wt % to 55 wt %, relative to the total weight of the one-component coating composition.

[0090] In an embodiment of the present invention, the one-component coating composition may contain any appropriate aqueous medium. Suitable aqueous medium includes water-soluble organic solvents, water and mixtures thereof.

[0091] In certain embodiments of the present invention, the one-component coating composition may further include additional additives commonly used in waterborne epoxy resin paints, which additives do not adversely affect the coating composition or the cured coating obtained therefrom. Suitable additives include, for example, those reagents that improve the processing properties or manufacturing properties of the composition, enhance the aesthetics of the composition, or improve the specific functional properties or characteristics (such as adhesion to substrate) of the coating composition or the cured composition obtained therefrom. The additives that may be included are, for example, dispersants, leveling agents, film-forming aids, cosolvents, bactericides, mildewicides, chain extenders, lubricants, biocides, plasticizers, defoamers, color extenders, waxes, antioxidants, adhesion promoters, UV stabilizers, or combinations thereof. The content of each optional component is sufficient to achieve its intended purpose, but preferably, such a content does not adversely affect the coating composition or the cured coating obtained therefrom. In a preferred embodiment of the present invention, suitable additional additives include dispersants, leveling agents, film-forming aids, cosolvents, or any combination thereof.

[0092] The content of each optional ingredient is sufficient to achieve its intended purpose, but preferably, such content does not adversely affect the one-component coating composition or the cured coating obtained therefrom. According to certain embodiments of the present invention, the total amount of additional additives is in the range of about 0 wt % to about 20 wt %, preferably in the range of about 0 wt % to about 10 wt %, relative to the total weight of the one-component coating composition.

[0093] The preparation of the one-component coating composition of the present invention can be achieved by any appropriate mixing method known to those skilled in the art. For example, the film-forming resin composition can be prepared by premixing the pigments and fillers and the aqueous medium and then grinding and dispersing them with a grinder to obtain a uniform system, then adding the system, the aqueous resin emulsion, the remaining pigments and fillers and additional additives (if any) into a container, and then stirring the resulting mixture to be uniform.

[0094] The one-component coating composition can be applied using various methods familiar to those skilled in the art, including spraying (e.g., air-assisted, airless or electrostatic spraying), brushing, roller coating, overflow coating and dipping. In one embodiment of the invention, the one-component coating composition is applied by spraying. The one-component coating composition can be applied to various wet film thicknesses. In some preferred embodiments, the wet film thickness provides a dry film thickness of at least about 30 μm, more preferably a dry film thickness of 35 to about 200 μm, and even more preferably about 45 to about 100 μm. The applied coating can be cured by air drying or by accelerating the curing using various drying devices familiar to those skilled in the art (e.g., ovens). The preferred heating temperature for curing the paint film is from about 60°C to about 100°C, and more preferably from about 60°C to about 80°C, and the preferred heating time is at least three minutes to less than 60 minutes, less than 45 minutes, less than 40 minutes. The heating time will tend to decrease with increasing temperature or increasing airflow.

[0095] In an embodiment according to the present invention, the one-component coating composition and the paint film formed therefrom show the desired coating stability and paint film performance, and preferably show performance equivalent to or higher than that of a conventional two-component polyurethane coating when tested by one or more of the following tests, including but not limited to coating stability, abrasion resistance, solvent impact resistance, fineness, drying speed, construction properties, acid and alkali resistance, salt spray resistance, flexibility and hardness.

[0096] Products

[0097] Another aspect of the present invention provides an article comprising: a substrate having at least one major surface; and a coating directly or indirectly coated on at least a portion of the major surface of the substrate, wherein the coating is formed by the one-component coating composition according to the present invention.

[0098] As the substrate for manufacturing the article of the present invention, any suitable substrate known in the art can be used. As an exemplary illustration, the substrate is selected from metal, wood, wood composite, paper, plastic, fabric, ceramic, cement material or any combination thereof.

[0099] In one embodiment of the present invention, the substrate is preferably a metal substrate. As an exemplary illustration, the metal substrate is selected from steel, iron, aluminum, zinc and alloys thereof.

[0100] According to the present invention, the article can be prepared, for example, by the following steps: (1) providing an optionally polished metal substrate; (2) sequentially coating and curing one or more one-component coating compositions of the present invention on the metal substrate using a coating and curing process to provide anti-corrosion properties to the metal substrate.

[0101] According to the present invention, the metal products thus obtained may be further treated with additional primers, anti-corrosion topcoats, and used in end-use applications including, but not limited to: refrigerated containers and non-refrigerated transport containers (e.g., dry cargo containers) from suppliers or manufacturers including China International Marine Containers (CIMC), Graaff Transportsysteme Gmbh, Maersk Line, and other suppliers or manufacturers known to those skilled in the art; chassis, trailers (including semi-trailers), rail vehicles, truck bodies, ships, bridges, building frames, and prefabricated or ready-made metal parts requiring temporary indoor or outdoor corrosion protection during fabrication. Additional uses include metal corners, channels, beams (e.g., I-beams), pipes, tubes, plates, or other components that can be welded into these or other metal parts.

[0102] As described above, the inventors of the present invention surprisingly found that in the formulation of a one-component coating composition, by adding an acrylic monomer and a silane coupling agent to a film-forming resin composition comprising at least one epoxy resin and at least one non-ionic reactive epoxy resin emulsifier (especially a non-ionic reactive epoxy resin emulsifier derived from cardanol polyoxyethylene ether), the storage stability of the one-component coating composition obtained thereby can be significantly improved, for example, it can be stable at room temperature for at least 180 days, and excellent salt spray resistance can be obtained.

[0103] Therefore, the present invention also provides a novel application in another aspect, namely, the use of at least one epoxy resin and at least one nonionic reactive epoxy resin emulsifier (especially a nonionic reactive epoxy resin emulsifier derived from cardanol polyoxyethylene ether) for improving the storage stability and salt spray resistance of a one-component coating composition. The preferred manner described above is also applicable here. For example, the one-component coating composition is preferably substantially free of a phosphorus-based emulsifier and a curing agent.

[0104] Example

[0105] The following examples more specifically describe the disclosure of the present invention, which are intended for illustrative purposes only, as various modifications and variations within the scope of the disclosure of the present invention are apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available and can be used directly without further treatment.

[0106] Test Method

[0107] Coating storage stability:Put the paint into a sealed container and store it at room temperature for 180 days, then open the lid and observe its condition. If the paint before storage is used as a reference, and the paint is in normal condition after storage, with no obvious sedimentation, no agglomeration and normal fineness, it means that the stability test has passed.

[0108] Pencil hardness : The hardness was measured using a pencil hardness tester according to ASTM D3363.

[0109] Salt spray resistance : Tested in accordance with ASTM B 117 using a salt spray cabinet at 35°C.

[0110] Water resistance test and acid and alkali resistance test :The coating was tested using the test methods and test standards in HG / T 4566-2013 standard.

[0111] Raw materials:

[0112] Epoxy resin: NPES 901 epoxy resin purchased from Nan Ya, with an epoxy equivalent weight of 450-500.

[0113] Nonionic reactive epoxy resin emulsifier: Nonionic reactive epoxy resin emulsifier GF-40 derived from cardanol polyoxyethylene ether, commercially available from Jiangsu Haian Petrochemical, is a light yellow solid with an epoxy equivalent of 10,000 to 40,000 and a pH of 5-8.

[0114] Styrene and acrylic monomers: isooctyl acrylate, cyclohexyl methacrylate, methyl methacrylate, methacrylic acid, ethyl acetoacetate methacrylate, general industrial products, commercially available.

[0115] Silane coupling agent: commercially available vinyltrimethoxysilane.

[0116] The comparative two-component polyurethane used Bayhydrol A 145 commercially available from Covestro as the main resin and Bayhydur 2655 commercially available from Covestro as the curing agent.

[0117] The control emulsifier is Dowfax 100N50 purchased from DOW Company, which is a nonionic surfactant of the polyoxyethylene / polyoxypropylene copolymer (EO / PO copolymer) type and does not contain an epoxy functional group.

[0118] Preparation of coating compositions

[0119] Using the components and amounts shown in Table 1 below, monomers, epoxy resin, sodium dodecylbenzene sulfonate, and water were mixed and homogenized to obtain a pre-emulsion, and then water and sodium dodecylbenzene sulfonate were added. The temperature was raised to about 84° C. Then sodium persulfate was added and reacted for 1 hour to obtain the coating compositions of Examples 1-5.

[0120] Referring to the preparation method of Example 1, the coating compositions of Comparative Examples 2-3 were prepared according to the components and amounts shown in Table 1. In Comparative Example 1, a comparative two-component polyurethane was used to replace the one-component coating composition in Example 1. In Comparative Example 2, epoxy resin and non-ionic reactive emulsifier were not used. In Comparative Example 3, a comparative emulsifier was used to replace the non-ionic reactive epoxy resin emulsifier in Example 1.

[0121] Then, the storage stability of the mixtures obtained in the above examples (denoted by Ex.) and comparative examples (denoted by CE.) at room temperature was tested respectively. In addition, the hardness, water resistance, acid and alkali resistance and salt spray resistance of the coating compositions according to the above examples and comparative examples were measured. The results are summarized in Table 1 and are also shown in Figure 1-3 middle.

[0122]

[0123]

[0124] From the results in Tables 1-2, it can be seen that the one-component coating composition of the present application can be stable at room temperature for at least 180 days. Moreover, compared with Comparative Example 1 using two-component polyurethane, Comparative Example 2 containing acrylic monomers but not containing epoxy resin and reactive emulsifier, and Comparative Example 3 containing no reactive emulsifier, the one-component coating composition of the present application can provide a coating having good gloss and hardness and excellent acid and alkali resistance after curing.

[0125] The cured coating of Example 1 showed no abnormality and had a smooth surface in the water resistance test, while the cured coating of Comparative Example 2 showed wrinkles, a rough surface and a plurality of fine round holes in the water resistance test under the same conditions, such as Figure 1 Moreover, compared with the cured coating of Comparative Example 2, the cured coating of Example 1 exhibits significantly better salt spray resistance on both tin-plated iron and cold-rolled steel sheets, as shown in FIG. Figure 2-3 shown.

[0126] It can be seen from the results of Examples 1-6 that by adjusting the ratio of each component, the obtained cured coating can have excellent salt spray resistance in addition to excellent water resistance and acid and alkali resistance.

[0127] Although the invention has been described with reference to a number of embodiments and examples, a person skilled in the art, based on the present disclosure, will recognize that other embodiments can be designed without departing from the scope and spirit of the invention.

Claims

1. A one-component coating composition comprising: at least one acrylic monomer, at least one epoxy resin, at least one silane coupling agent, and At least one nonionic reactive epoxy resin emulsifier.

2. The one-component coating composition according to claim 1, wherein the acrylic monomer is selected from one or more of (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxymethyl (meth)acrylic acid amide.

3. The one-component coating composition according to claim 1 or 2, wherein the amount of the acrylic monomer is 5 to 60 wt% based on the total weight of the one-component coating composition.

4. The one-component coating composition according to any one of claims 1 to 3, wherein the epoxy resin is a diglycidyl ether of a polyphenol having the following structural formula (I): in, D represents -S-, -SS-, -SO-, -SO2-, -CO2-, -CO-, -O- or a divalent C1-C 10 Alkylene, Each Y independently represents a halogen, or an optionally substituted monovalent C1-C 10 Hydrocarbon, Each m independently represents 0, 1, 2, 3 or 4, n is an integer of 0-4.

5. The one-component coating composition according to any one of claims 1 to 4, wherein the epoxy resin itself exists in a solid form at normal temperature and pressure.

6. The one-component coating composition according to any one of claims 1 to 5, wherein the epoxy resin has an epoxy equivalent in the range of 200 g / eq to 2000 g / eq, preferably in the range of 220 g / eq to 1500 g / eq, more preferably in the range of 250 g / eq to 1000 g / eq.

7. The one-component coating composition according to any one of claims 1 to 6, wherein the total amount of the at least one epoxy resin is 2 to 60 wt. %, based on the total weight of the one-component coating composition.

8. The one-component coating composition according to any one of claims 1 to 7, wherein the silane coupling agent has Y(CH2) n SiX3, wherein n=0, 1, 2 or 3, Y is or contains one or more of alkenyl, (meth)acryloyloxy, aminoalkyl, isocyanatoalkyl, epoxyalkyl, ureidoalkyl, and Each X is independently selected from methyl, ethyl, methoxy, ethoxy, propoxy, isopropoxy or trimethylsiloxy, with the proviso that at least one X is methoxy, ethoxy, propoxy, isopropoxy or trimethylsiloxy.

9. The one-component coating composition according to any one of claims 1 to 8, wherein the silane coupling agent is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, (meth)acryloxypropyltrimethoxysilane, (meth)acryloxypropyltriethoxysilane, (meth)acryloxypropylmethyldimethoxysilane, (meth)acryloxypropylmethyldiethoxysilane, (meth)acryloxypropyltri(trimethylsiloxy)silane, γ-aminopropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, and diethoxymethyl[(3-oxiranylmethoxy)propyl]silane.

10. The one-component coating composition according to any one of claims 1 to 9, wherein the at least one nonionic reactive epoxy resin emulsifier is derived from one or more of butyl glycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, cardanol polyoxyethylene ether and cardanol glycidyl ether.

11. The one-component coating composition according to claim 10, wherein the cardanol polyoxyethylene ether has a structure shown in the following formula (I): in, n is in the range of 10-60.

12. The one-component coating composition according to any one of claims 1 to 11, wherein the weight ratio of the at least one nonionic reactive epoxy resin emulsifier to the at least one epoxy resin is in the range of 1:20 to 1:1.

2.

13. The one-component coating composition according to any one of claims 1 to 12, wherein the composition is substantially free of phosphorus-based emulsifiers.

14. The one-component coating composition according to any one of claims 1 to 13, wherein: A weight ratio of the acrylic monomer to the epoxy resin is in a range of 5:1 to 1:

5.

15. The one-component coating composition according to any one of claims 1 to 14, wherein The one-component coating composition is stable at room temperature for at least 180 days.

16. A coated product comprising a substrate having at least one major surface; and a coating applied directly or indirectly to at least a portion of the major surface of the substrate, in, The coating is formed from the one-component coating composition according to any one of claims 1 to 15.

17. The coated product according to claim 16, wherein The substrate is selected from metal, wood, wood composite, paper, plastic, fabric, ceramic, cement material or any combination thereof.

18. The coated product according to claim 16 or 17, wherein The coating thickness is at least 30 μm.

19. The coated product according to any one of claims 16 to 18, wherein The coating does not blister in a salt spray test at 35°C for at least 500 hours.

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