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EP-4735538-A1 - 1K COATING COMPOSITION AND COATED ARTICLE

EP4735538A1EP 4735538 A1EP4735538 A1EP 4735538A1EP-4735538-A1

Abstract

The present application relates to a 1K coating composition and a coated article. The 1K coating composition includes: at least one acrylic monomer, at least one epoxy resin, at least one silane coupling agent, and at least one non-ionic reactive epoxy resin emulsifier. The 1K coating composition in the present application can be substantially free of phosphorus-based emulsifiers, has good storage stability, is relatively simple to apply, and can provide an excellent acid and alkali resistant coating. The 1K coating composition in the present application is well suited for application to a wide variety of substrates, particularly for direct application to metal/metallic substrates.

Inventors

  • WU, Libin
  • ZHANG, YU

Assignees

  • Sherwin-Williams (Guangdong) New Material Co., Ltd.

Dates

Publication Date
20260506
Application Date
20240725

Claims (19)

  1. A 1K coating composition comprising: at least one acrylic monomer, at least one epoxy resin, at least one silane coupling agent, and at least one non-ionic reactive epoxy resin emulsifier.
  2. The 1K coating composition according to claim 1, wherein the acrylic monomer is one or more 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, and hydroxymethyl (meth) acrylate.
  3. The 1K coating composition according to claim 1 or 2, wherein based on the total weight of the 1K coating composition, the acrylic monomer is present in an amount of from 5 wt. %to 60 wt. %.
  4. The 1K coating composition according to any one of claims 1 to 3, wherein the epoxy resin is a diglycidyl ether of a polyhydric phenol having the following structural formula (I) : wherein D represents-S-, -S-S-, -SO-, -SO 2 -, -CO 2 -, -CO-, -O-or divalent C 1 -C 10 alkylene, each Y independently represents halogen, or optionally substituted monovalent C 1 -C 10 hydrocarbon group, each m independently represents 0, 1, 2, 3 or 4, n is an integer from 0 to 4.
  5. The 1K coating composition according to any one of claims 1 to 4, wherein the epoxy resin alone is present in solid form at normal temperature and pressure.
  6. The 1K coating composition according to any one of claims 1 to 5, wherein the epoxy resin has an epoxy equivalent ranging from 200 g/eq to 2000 g/eq, preferably ranging from 220 g/eq to 1500 g/eq, more preferably ranging from 250 g/eq to 1000 g/eq.
  7. The 1K coating composition according to any one of claims 1 to 6, wherein based on the total weight of the 1K coating composition, the at least one epoxy resin is present in a total amount of from 2 wt. %to 60 wt. %.
  8. The 1K coating composition according to any one of claims 1 to 7, wherein the silane coupling agent has a formula of Y (CH 2 ) n SiX 3 , wherein n = 0, 1, 2 or 3, Y is or comprises one or more of alkenyl, (meth) acryloyloxy, aminoalkyl, isocyanatoalkyl, epoxyalkyl, and ureidoalkyl, 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.
  9. The 1K coating composition according to any one of claims 1 to 8, wherein the silane coupling agent is one or more selected from vinyl trimethoxysilane, vinyl triethoxysilane, vinyl triisopropoxysilane, (meth) acryloxypropyl trimethoxysilane, (meth) acryloxypropyl triethoxysilane, (meth) acryloxypropyl methyldimethoxysilane, (meth) acryloxypropyl methyldiethoxysilane, (meth) acryloxypropyl tris (trimethylsiloxy) silane, γ-aminopropyl trimethoxysilane, tris (3-trimethoxysilylpropyl) isocyanurate, γ-isocyanatopropyl trimethoxysilane, γ-isocyanatopropyl triethoxysilane, 3-glycidyloxypropyl triethoxysilane, and diethoxymethyl [ (3-oxiranylmethoxy) propyl] silane.
  10. The 1K coating composition according to any one of claims 1 to 9, wherein the at least one non-ionic 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 1K coating composition according to claim 10, wherein the cardanol polyoxyethylene ether has a structure represented by the following formula (II) : wherein n is in the range of from 10 to 60.
  12. The 1K coating composition according to any one of claims 1 to 11, wherein a weight ratio of the at least one non-ionic reactive epoxy resin emulsifier to the at least one epoxy resin is in a range of from 1: 20 to 1: 1.2.
  13. The 1K coating composition according to any one of claims 1 to 12, wherein the composition is substantially free of phosphorus-based emulsifiers.
  14. The 1K 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 from 5: 1 to 1: 5.
  15. The 1K coating composition according to any one of claims 1 to 14, wherein the 1K coating composition is stable at room temperature for at least 180 days.
  16. A coated article, comprising: a substrate having at least one major surface; and a coating directly or indirectly applied on at least part of the major surface of the substrate, wherein the coating is formed from the 1K coating composition according to any one of claims 1 to 15.
  17. The coated article according to claim 16, wherein the substrate is selected from metal, wood, wood composite, paper, plastic, fabric, ceramic, cementitious material, or any combination thereof.
  18. The coated article according to claim 16 or 17, wherein the coating has a thickness of at least 30 μm.
  19. The coated article according to any one of claims 16 to 18, wherein the coating does not blister for at least 500 hours in a salt spray test at 35℃.

Description

1K COATING COMPOSITION AND COATED ARTICLE TECHNICAL FIELD The present application relates to a 1K coating composition and a coated article, and more particularly to a 1K coating composition that is substantially free of phosphorus-based emulsifiers and has good storage stability and is capable of providing an excellent acid and alkali resistant coating. BACKGROUND Various coating compositions have been designed in the coatings industry for coating a variety of substrates. Currently, in applications where acid and alkali resistant coatings are required and salt spray resistant coatings are more desirable, two-component coating compositions containing phosphorus-based emulsifiers are mostly used in the market. However, phosphorus is the “culprit” that leads to eutrophication and bloom of water bodies, which leads to the greatly reduced amount of dissolved oxygen in water of lakes, rivers and other water environments and causes plankton and aquatic animals such as fish to die due to lack of oxygen, resulting in the destruction of water environment and ecological imbalance. As a result, more and more countries and regions have issued regulations of “prohibiting phosphorus” or “limiting phosphorus” . Moreover, the two-component coating composition usually requires high-cost resins and curing agents, and the strictly controlled storage conditions and application processes, otherwise it will easily suffer from the problems such as coating failure, short pot life, and unstable performance of paint film. For example, the process for applying two-component coatings is usually complicated and requires the two components to be blended on site at a stable blending ratio as needed. If the incorrect blending ratio happens to be used, the coating film may exhibit premature rust, blistering, or other types of failed coating films. Such failures typically result in expensive removal of the failed coating films and application of a new coating. Therefore, the properties of the final coating obtained from a two-component coating composition are susceptible to factors such as the formulation process, the skill level of the technicians, and the like. In addition, curing agents (such as isocyanate curing agents) often have relatively active chemical properties and structural fragments that are toxic to the human body. SUMMARY In view of the foregoing, there is a need in the coating industry for a coating composition that is substantially free of phosphorus-based emulsifiers (for example, phosphoric acid ester-based emulsifiers and emulsifiers derived from phosphoric acid esters) , has good storage stability, and is relatively simple to apply, and enables obtaining excellent acid and alkali resistant coatings. After intensive investigation, the inventors of the present application have found that the above object can be achieved by using the 1K (one-component) coating composition provided herein. The first aspect of the present application provides a 1K coating composition comprising: at least one acrylic monomer, at least one epoxy resin, at least one silane coupling agent, and at least one non-ionic reactive epoxy resin emulsifier. The inventors have found that by using the 1K coating composition having the specific components/composition as described above, the resulting coating can exhibit good storage stability and excellent water resistance and excellent acid and alkali resistance, without using a phosphorus-based emulsifier and a curing agent. This is very surprising because, unlike mainstream coatings containing phosphorus-based emulsifiers, the 1K coating composition of the present application can provide excellent salt spray resistant coatings without the use of phosphorus-based emulsifiers, meeting the relevant regulations of “prohibiting phosphorus” or “limiting phosphorus” . It is particularly surprising that, in addition to storage stability, water resistance, acid and alkali resistance, some preferred embodiments of the present application enable particularly excellent salt spray resistance, for example, to provide a coating that does not blister for at least 500 hours in a salt spray test at 35℃. It is also surprising that, according to common knowledge in the art, epoxy resins need to be crosslinked with curing agents (i.e. forming two-component composition) in order to provide excellent coatings. However, the coating composition of the present application is present in one component, in which a curing agent is not necessary while a  coating with excellent properties is still provided. Moreover, the inventors of the present application have conducted numerous experimental studies and surprisingly found that a storage-stable coating composition can be obtained by combining a non-ionic reactive epoxy resin emulsifier, a waterborne epoxy resin, an acrylic monomer, and a silane coupling agent. The acrylic monomer having a reactive group and the epoxy resin contained in the 1K coating composition of the presen