TW202342655A - Two-component coating composition, preparation method thereof and coated product - Google Patents

Abstract

The invention relates to a two-component coating composition, a preparation method thereof and a coated product. The double-component coating composition comprises a component A and a component B, and is characterized in that the component A comprises at least one epoxy resin and at least one conductive filler, the component B comprises at least one alicyclic amine curing agent, based on the total weight of the component A, the total amount of the conductive filler is 0.05-8 wt%, and the total amount of the alicyclic amine curing agent is 0.05-8 wt%. The viscosity of the component A at 25 DEG C is less than 140 KU, and the volume solids content of the two-component coating composition is greater than 60%. The two-component coating composition provided by the invention has high solid content and excellent construction performance, and can produce a static conductive anti-corrosion coating with good hot water resistance.

Description

Two-component coating composition and preparation method and coating product thereof

The present invention relates to two-component coating compositions, methods for their preparation and coated articles. In particular, the present invention relates to technical fields that require good resistance to hot water, high solid content, and low viscosity for electrostatic conductivity and anti-corrosion.

With the rapid development of the economy, coatings applied to metal substrates are facing more and more problems and the requirements are getting higher and higher. For example, metal pipes or containers used in chemical production and transportation (such as oil pipelines, storage tanks, and tankers) are prone to corrosion and static electricity problems. Such pipes or vessels are generally larger and more material-intensive, and for economic reasons are often made of lower-cost materials (such as carbon steel) rather than more expensive corrosion-resistant alloys.

Substances (such as water, sulfur, sulfur dioxide, carbon dioxide) present in petroleum and other chemicals can easily cause corrosion on the inner surface of pipelines or containers. Especially in low latitudes, for transportation pipelines extending close to the surface, long-term exposure to the sun and long-distance contact with the surface further aggravates the corrosion effect. Corroded pipes are difficult and expensive to replace. Moreover, during use, it is easy to accumulate static charges, causing serious safety hazards.

Most of the anti-corrosion conductive coatings currently on the market require the addition of a large amount of conductive fillers, resulting in unsatisfactory construction performance of the coatings, and even the need to add more diluents, resulting in an increase in volatile organic compounds (VOC). , solid content decreases. Moreover, currently commercially available anti-corrosion conductive coatings generally cannot meet long-term corrosion requirements at higher temperatures (for example, above 90°C).

In view of this, there is a need for a conductive coating that combines high solids content with excellent application properties and is capable of producing good resistance to high temperature corrosion.

The above objectives are achieved through the two-component coating compositions described herein.

A first aspect of the present invention provides a two-component coating composition, including component A and component B, characterized in that component A includes at least one epoxy resin and at least one conductive filler, and component B includes at least one grease. Cyclic amine curing agent, wherein the total amount of conductive filler is 0.05-8% by weight based on the total weight of component A, the viscosity of component A at 25°C is less than 140KU, and the volume solid content of the two-component coating composition greater than 60%.

A second aspect of the present invention provides a method for preparing a two-component coating composition, which includes mixing component A and component B, wherein component A includes at least one epoxy resin and at least one conductive filler, and component B The component contains at least one alicyclic amine curing agent, wherein the total amount of conductive filler is 0.05-8% by weight based on the total weight of component A, the viscosity of component A at 25°C is less than 140KU, and the two-component coating combination The volume solid content of the material is greater than 60%.

A third aspect of the present invention provides a coated product, characterized in that the coated product includes: a substrate having at least one major surface; and a substrate coated on the at least one major surface of the metallic substrate. The two-component coating composition or its cured coating.

The inventors surprisingly found that the two-component coating composition described in the present invention is an anti-corrosion coating composition with conductive properties, which can have high solid content and excellent construction performance, and can produce products with good hot water resistance and excellent Conductive coating. In particular, the coating or cured paint film of the present invention has a high volume solid content, can be soaked in hot water at 95°C for a long time (for example, up to or even more than 240 hours) without bubbling the paint film, and has a surface resistance Can reach 10 ⁷ ~10 ¹¹ Ω. The cured paint film of the coating of the present invention does not foam in the 1000h salt spray test, does not foam when immersed in 5% sulfuric acid for 720h, does not foam when immersed in 5% sodium hydroxide for 720h, and does not foam when immersed in 5% sodium chloride for 720h, and No foaming after immersion in crude oil at 60°C for 720 hours.

Moreover, the coating of the present invention has the advantages of low VOC (even solvent-free) and low cost, is a healthy and environmentally friendly product, and is more easily accepted by consumers.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. Illustrative embodiments are illustrated in more detail in the description below.

definition

When used herein, "a," "the," "at least one," and "one or more" are used interchangeably unless otherwise stated. Thus, for example, a coating composition containing "an" additive may be interpreted to mean that "one or more" additives are included in the coating composition. Unless otherwise indicated herein, use of the singular form herein is intended to include the plural form as well.

Unless expressly stated otherwise, use of the terms "includes," "includes," "contains," and "has" should generally be construed as open-ended and non-limiting. For example, where a composition is described as including or containing a particular component, it is contemplated that optional components not covered by the invention are not excluded from the composition, and it is contemplated that the composition may consist of or consist of the referenced components. , or where a method is described as including or containing specific process steps, it is contemplated that optional process steps not covered by the present invention are not excluded from the method, and it is contemplated that the method may consist of or consist of the involved process steps.

For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unexpressed range; and any lower limit can be combined with other lower limits to form an unexpressed range, and likewise any upper limit can be combined with any other upper limit to form an unexpressed range. In addition, although not explicitly stated, every point or individual value between the endpoints of a range is included in the range. Thus, each point or single value may serve as a lower or upper limit on its own in combination with any other point or single value or with other lower or upper limits to form a range not expressly recited.

Unless otherwise stated, every point or individual value between the endpoints of a range is included in the range. For example, the range 1 to 5 covers the values 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc. Furthermore, the disclosed numerical range includes all subset ranges within the broader range, for example, the range of 1 to 5 includes the subranges of 1 to 4, 1.5 to 4.5, 1 to 2, etc. Thus, each point or single value can be combined as a lower or upper limit with any other point or single value or with other lower or upper limits, and the resulting range falls within the express disclosure of the invention.

When used herein, the term "or" is inclusive. that is, the phrase "A or (or) B" means "A, B, or both A and B", and can also be abbreviated as "A and/or B". More specifically, condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; Or both A and B are true (or exist). In contrast, the exclusive "or" is represented herein, for example, by terms such as "either A or B" and "either A or B."

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

The term "anticorrosive coating composition" refers to a coating composition that, when applied in one or more layers to a metallic substrate, forms a coating that can last for a substantial period of time. Exposed to corrosive conditions for a period of time (e.g., salt spray exposure for three weeks or more) without objectionable visible deterioration or corrosion.

The term "volume solids content" refers to the nonvolatile volume fraction of the coating. It can be determined according to standard test methods commonly used in the art. For example, the volume solid content can be tested according to GB/T 9272-2007.

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

Two-component coating composition

The two-component coating composition according to the first aspect of the present invention includes component A and component B, wherein component A includes at least one epoxy resin and at least one conductive filler, and component B includes at least one alicyclic amine curing agent , based on the total weight of component A, the total amount of the conductive filler is 0.05-8% by weight, the viscosity of component A at 25°C is less than 140KU, and the volume solid content of the two-component coating composition is greater than 60%.

It can be seen that relatively low amounts of conductive fillers can be used in the coatings of the present invention. It can still achieve better electrostatic conductivity and construction performance. This is completely different from the common knowledge in the art. Before the present invention, in order to obtain conductive coatings, those skilled in the art usually needed to add a larger amount (usually 15% by weight, 25% by weight or more) of conductive filler, such as Conductive mica powder and conductive barium sulfate. However, the inventor found that adding such a large amount of conductive fillers (especially conductive mica powder) will cause the viscosity of the coating to increase, seriously affecting the sprayability, dispersion and wettability of the coating to the substrate, resulting in a significant reduction in construction performance. It even affects the liquid medium resistance and heat resistance of the coating. Moreover, conventional conductive fillers usually provide conductive properties by surface modification to generate a conductive oxide layer on the surface of the body. For example, mica and barium sulfate are insulating by themselves, but after appropriate surface modification produce conductive mica and conductive barium sulfate. However, this surface modification often results in very high oil absorption values, which consumes the film-forming resin and increases production costs.

Desirably, the coatings of the present invention preferably employ relatively few conductive fillers, especially surface-modified conductive fillers (eg, conductive mica powder and conductive barium sulfate). In some embodiments, the total amount of conductive filler in component A is no more than 6 wt%, preferably no more than 5 wt%, more preferably no more than 3 wt%, even more preferably, based on the total weight of component A. Not more than 2% by weight. In some embodiments, the total amount of conductive filler in component A is at least 0.08 wt%, preferably at least 0.1 wt%, based on the total weight of component A. As an example, based on the total weight of component A, the total amount of conductive filler in component A is 0.1-1.5% by weight, such as 0.15% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight %, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.4 wt%, 1.5 wt%, 2.5 wt%.

In some embodiments, the total amount of conductive mica powder and conductive barium sulfate is no more than 5% by weight, preferably no more than 4% by weight, more preferably no more than 3% by weight, such as no more than 3% by weight, based on the total weight of component A. More than 2% by weight, not more than 1% by weight, not more than 0.5% by weight. Even more preferably, component A is free of conductive mica powder and conductive barium sulfate.

In the two-component coating compositions described herein, conductive fillers that are highly conductive and do not adversely affect coating properties can be used. In some embodiments, the conductive filler includes at least one selected from the group consisting of conductive carbon black, acetylene black, conductive mica powder, graphite, graphene, Ketjen black, carbon nanofibers, carbon nanotubes, conductive barium sulfate, and conductive titanium dioxide. or a variety of conductive fillers. Excellent Optionally, the conductive filler includes at least one or more conductive fillers selected from the group consisting of graphite, graphene, carbon nanofibers, carbon nanotubes, and conductive titanium dioxide. More preferably, the conductive filler includes at least one or more conductive fillers selected from graphene, carbon nanofibers, and carbon nanotubes. Even more preferably, the conductive filler contains carbon nanotubes or carbon nanofibers.

The carbon nanotubes may be single-walled carbon nanotubes, multi-walled carbon nanotubes or combinations thereof, preferably including single-walled carbon nanotubes. Single-walled carbon nanotubes with higher aspect ratios can be used. In some embodiments, the single-walled carbon nanotubes have an aspect ratio of at least 1500:1, preferably at least 1800:1, such as 2000-10000:1. The d10 of carbon nanotubes can be 1.0-2.0nm, the d50 can be 1.4-2.5nm, and the d90 can be 1.6-2.7nm. For example, carbon nanotubes have d10=1.2-1.45nm, d50=1.6-1.8nm, and d90=1.9-2.2nm. In addition, the inventor also noticed that after being dispersed in component A, the carbon nanotubes mainly exist in the form of bundle-like aggregates. The bundle-like aggregates may have a diameter of 0.1-2 microns and a length of 10-100 microns, for example a diameter of 0.2-0.5 microns and a length of 20-30 microns. As an example, carbon nanotubes may include the TUBALL MATRIX line of products from OCSiAl.

In the two-component coating compositions described herein, component A has a relatively low viscosity. Preferably, the viscosity at 25°C is less than 120 KU, more preferably less than 115 KU, even more preferably less than 110 KU.

The two-component coating compositions described herein have relatively high solids contents. Preferably, the volume solids content of the two-component coating composition is greater than or equal to 65%, more preferably greater than or equal to 70%, further preferably greater than or equal to 75%, even more preferably greater than or equal to 80%.

In the two-component coating compositions described herein, the epoxy resin may comprise novolac epoxy resin, bisphenol A epoxy resin, or a combination of both. In some embodiments, the novolac epoxy resin has an epoxy equivalent weight of less than 300, preferably less than 250, more preferably less than 200 g/eq. For example, the novolac epoxy resin may have an epoxy equivalent weight of about 160, about 165, about 170, about 185, about 190, about 195 g/eq. In some embodiments, the bisphenol A epoxy resin has an epoxy equivalent weight of less than 300, preferably less than 250, more preferably less than 200 g/eq. For example, bisphenol A epoxy resin may have an epoxy equivalent weight of about 180, about 185, about 190, about 195 g/eq.

In the two-component coating compositions described herein, by using a phenolic epoxy resin Combining with bisphenol A epoxy resin and controlling the ratio of the two can further obtain heat resistance, chemical stability and corrosion resistance, while maintaining excellent coating adhesion and strength and lower cost. In some embodiments, the weight ratio of bisphenol A epoxy resin and novolac epoxy resin is 1:1 to 10:1, preferably 1.5:1 to 8:1, preferably 2:1 to 5:1, for example 3:1, 4:1, 6:1, 7:1.

The amount of epoxy resin may be 20-48% by weight, preferably 25-45% by weight, more preferably 30-40% by weight, such as about 35% by weight, about 28% by weight, based on the total weight of component A.

The two-component coating compositions described herein provide coatings with excellent conductivity that meet industry requirements for electrostatic conductivity of coatings on metallic substrates. In some embodiments, the surface resistivity of the cured paint film obtained after component A and component B are mixed and coated is 1×10 ² to 1×10 ¹¹ Ω, preferably 1×10 ⁵ to 1×10 ¹⁰ Ω , more preferably 1×10 ⁷ to 1×10 ⁹ Ω, such as 1×10 ⁸ Ω. The surface resistivity described herein can be determined according to universal standards, for example according to GB/T 1410-2006. Unless otherwise stated, surface resistivity is measured at 23±2°C and 50±5% relative humidity.

The two-component coating composition may also include a silane coupling agent. In some embodiments, the coupling agent includes a silane compound having Formula I:

wherein each _{X1 is} independently selected from the group consisting of -Cl _{, -OCH3} , _{-OCH2CH3, -OC2H4OCH3 , -OSi} ( _CH3 ) _3, and _-OCOCH3 ; and

Y ₁ is an alkyl group blocked by -Cl, -NH ₂ , -SH, -OH, epoxy group, -N ₃ , γ-methacryloxypropyl group or isocyanate group.

In some embodiments, the silane coupling agent has a molecular weight of 100-800 Daltons, preferably 200-400 Daltons, such as about 150 Daltons, about 250 Daltons, 300 Daltons.

Preferably, the silane coupling agent is an epoxy silane coupling agent. For example, in Formula I, _Y1 is an alkyl group terminated by an epoxy group.

The inventor found that on the one hand, the active group of the silane coupling agent reacts with the metal oxide on the metal surface or the water on the surface to form hydrogen bonds, which improves the adhesion of the coating to the metal substrate. Silanes, on the other hand, react with the amine curing agents in the paint to make the coating denser. In particular, the benefits of these two aspects are more prominent when using epoxy silane coupling agents. Even more surprisingly, the inventors found that when an epoxy silane coupling agent was added to the two-component coating composition described herein, the hot water resistance of the cured coating was significantly improved with excellent reproducibility. Suitable for large-scale industrial applications.

More importantly, in some embodiments, by adding smaller amounts of silane coupling agent, the beneficial effects described above can be observed. Based on the total weight of component A, the amount of silane coupling agent may be 0.2-2% by weight, preferably 0.3-1.8% by weight, more preferably 0.5-1.5% by weight. For example, the amount of silane coupling agent may be about 0.4% by weight, about 0.5% by weight, about 0.6% by weight, about 0.8% by weight, about 1.0% by weight, or about 1.2% by weight.

In the two-component coating composition according to the present invention, component A may contain pigments and fillers. Examples of pigments and fillers may include talc powder, quartz powder, barium sulfate, mica powder, wollastonite powder, titanium dioxide, iron red powder, zinc phosphate, zinc oxide, aluminum tripolyphosphate, modified zinc phosphate and kaolin. In some embodiments, component A includes one or more of talc powder, quartz powder, barium sulfate, titanium dioxide and wollastonite powder. As needed, anti-corrosion functional fillers such as aluminum tripolyphosphate and modified zinc phosphate can be added to greatly improve the anti-corrosion performance.

In some embodiments, component A includes one or more of talc powder, quartz powder, barium sulfate, and wollastonite powder with a particle size of 100 mesh to 1500 mesh. In some embodiments, component A includes talc with a particle size ranging from 200 mesh to 1000 mesh, preferably from 300 mesh to 800 mesh, more preferably from 400 mesh to 600 mesh. The inventors surprisingly found that the surface resistivity of the cured coating can be further improved by adjusting the particle size of the pigments and fillers.

Based on the total weight of component A, the amount of pigments and fillers may be 40-70% by weight, preferably 45-65% by weight, more preferably 50-60% by weight. For example, the amount of pigments and fillers may be about 43% by weight, about 48% by weight, about 53% by weight, about 58% by weight, or about 62% by weight.

In the two-component coating composition according to the invention, component A may also contain conventional additives which do not adversely affect the two-component coating composition or the cured coating obtained therefrom. Suitable additives include, for example, those that improve the processing or manufacturing properties of the composition, enhance the combination Those agents that improve the aesthetics of an object, improve specific functional properties or characteristics of a coating composition or a cured composition derived therefrom (such as adhesion to a substrate), or reduce costs. Additives that may be included are, for example, lubricants, film-forming aids, wetting agents, plasticizers, defoaming agents, colorants, antioxidants, flow control agents, thixotropic agents, matte powders, dispersants, adhesion promoters, Thickeners, pH adjusters, curing catalysts or combinations thereof. Each optional ingredient is present in an amount sufficient to achieve its intended purpose, but preferably such an amount does not adversely affect the two-component coating composition or the cured coating resulting therefrom. In some preferred embodiments, component a may include defoaming agents, film-forming aids, wetting agents, leveling agents, thickeners, matte powders or any combination thereof as conventional additives. According to the invention, the total amount of conventional additives is from 0.1% to 25% by weight, for example about 10% by weight, relative to the total weight of component a. In some embodiments, the amount of dispersant may be 0.1-1% by weight, the amount of defoaming agent may be 0.1-0.3% by weight, the amount of wetting agent may be 0.5-2% by weight, and the amount of leveling agent may be 0.5-2% by weight, alternatively, the amount of thixotropic agent may be 0.1-1% by weight.

The two-component coating composition of the present invention has relatively few volatile components. In some embodiments, component A contains 0-15 wt%, preferably 0-12 wt% organic solvent based on the total weight of component A. For example, component A includes about 2%, 5%, 7%, 10% by weight of organic solvent based on the total weight of component A. Examples of organic solvents include monohydric or polyhydric alcohols, such as propanol, butanol, hexanol, benzyl alcohol; glycol ethers or esters, such as diethylene glycol dialkyl ether, dipropylene glycol, each having a C1-C6 alkyl group. Dialkyl ethers, ethoxypropanol, butylglycol; glycols, such as ethylene glycol, propylene glycol; and ketones, such as methyl ethyl ketone, acetone, cyclohexanone; N-methylpyrrolidone, N - Ethylpyrrolidone; aromatic or aliphatic hydrocarbons, such as toluene, xylene or straight-chain or branched aliphatic C6-C12 hydrocarbons. In some embodiments, the organic solvent includes xylene, butanol, propylene glycol methyl ether, benzyl alcohol, or any combination thereof.

In some embodiments, based on the total weight of component A, component A includes:

25-45% by weight epoxy resin,

0.1-2% by weight conductive filler,

40-70% by weight of pigments and fillers,

0.2-2% by weight silane coupling agent,

0-15% by weight of organic solvent.

In the two-component coating compositions described herein, component B contains an alicyclic amine curing agent. The inventor found that compared with other curing agents (for example, polyamide curing agents, cardanol curing agents, aliphatic polyamine curing agents, aromatic amine curing agents), the alicyclic amine curing agent has a cyclic structure in its structure. , it has excellent heat resistance, and after reacting with epoxy resin, it forms a dense network structure coating, which blocks the penetration of hot water and corrodes the metal. The hot water resistance of the coating can be further improved by selecting an appropriate alicyclic amine curing agent.

In some embodiments, the alicyclic amine curing agent may have an active hydrogen equivalent of 80-140 g/eq, preferably 90-110 g/eq, such as about 95 g/eq, about 100 g/eq, about 105 g/eq, about 110 g/eq. eq, active hydrogen equivalent of about 115g/eq. Examples of cycloaliphatic amine curing agents include JH 5933 from Jadida New Materials, ARADUR 265-1 from Huntsman, ANCAMINE 2719 from Evonik, ANCAMINE 2280 and ANCAMINE 2143 from Evonik.

The inventor found that by using a combination of alicyclic amine curing agent (especially JH 5933 curing agent) and epoxy silane coupling agent, the cured coating obtained showed particularly excellent hot water resistance when tested in 95°C hot water. At the same time, other properties of the coating are retained or improved.

Component B may contain 0-15% by weight of organic solvent. The above description about the organic solvent contained in component A also applies to the organic solvent contained in component B. No further details will be given here. On the basis of the present invention, those skilled in the art can reasonably determine and select the amount of organic solvent contained in component B according to actual needs.

In the two-component coating composition described herein, the relative amounts of component A and component B can be adjusted as needed. In some embodiments, the volume ratio of component A to component B is 1:1 to 10:1, preferably 1:1 to 10:1, more preferably 2:1 to 8:1, such as 3:1 , 4:1, 5:1, 6:1, 7:1.

According to the present invention, the two-component coating composition can be prepared as follows: before application, component A and component B are simply mixed in a mixing device in a predetermined ratio. The resulting coating composition may be applied using a variety of methods familiar to those skilled in the art, including spraying (eg, air-assisted, airless, or electrostatic spraying), brushing, roller coating, flood coating, and dipping. In one of the invention In embodiments, the mixed coating composition is applied by spraying. The coating composition can be applied to various wet film thicknesses. In embodiments of the present invention, the wet film thickness preferably provides a dry film thickness of about 13 to about 260 μm, and more preferably about 75 to about 150 μm. The applied coating may be cured by allowing it to air dry or by accelerating curing using various drying devices (eg, ovens) familiar to those skilled in the art.

Methods of preparing two-component coating compositions

A second aspect of the present invention provides a method for preparing a two-component coating composition, which includes mixing component A and component B, wherein component A includes at least one epoxy resin and at least one conductive filler, and component B The component contains at least one alicyclic amine curing agent, wherein the total amount of conductive filler is 0.05-8% by weight based on the total weight of component A, the viscosity of component A at 25°C is less than 140KU, and the two-component coating combination The volume solid content of the material is greater than 60%.

What is said in the context of the two-component coating composition also applies to the method for preparing the two-component coating composition.

Coated products

A third aspect of the present invention provides a coated product, characterized in that the coated product includes: a substrate having at least one major surface; and a substrate coated on the at least one major surface of the metallic substrate. The two-component coating composition or its cured coating.

The two-component coating composition of the present invention can be coated directly on the substrate or on a coating on the substrate. In some embodiments, the two-component coating compositions of the present invention can be used with a primer. In this case, the article of the invention includes a substrate, a primer layer and a coating formed from the two-component coating composition of the invention. In other embodiments of the present invention, the two-component coating composition of the present invention can be applied without primer and directly coated on the main surface of the substrate.

As the metallic substrate used to manufacture the articles of the present invention, any suitable metallic substrate known in the art may be used. As an example, the metallic substrate may include iron substrate, aluminum substrate, carbon steel or stainless steel.

According to the present invention, the coated article can be prepared by, for example, the following steps: (1) providing a polished metallic substrate; (2) utilizing a coating process to sequentially coat and form one or more layers of the present invention on the metallic substrate. The coating composition described in is cured to obtain a cured coating.

The metal products of the present invention can be used in the following end applications, including but not limited to: available from suppliers or manufacturers including China International Marine Containers (CIMC), Graaff Transportsysteme Gmbh, Maersk Line and others known to those of ordinary skill in the art. Refrigerated containers and non-refrigerated transport containers (such as dry cargo containers) including suppliers or manufacturers; chassis, trailers (including semi-trailers), rail vehicles, truck bodies, ships, bridges, petrochemical storage tank linings, buildings Skeletons and prefabricated or existing metal parts requiring temporary indoor or outdoor corrosion protection during fabrication. Additional uses include metal angles, channels, beams (such as I-beams), pipes, tubes, plates or other components that can be welded into these or other metal parts.

Example

The present disclosure is more particularly described in the following examples, which are intended to be illustrative only, as it will be apparent to those skilled in the art that various modifications and changes can be made within the scope of the present disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight. Furthermore, all reagents used in the examples are commercially available and can be used directly without further processing.

Test method

Volume solid content: tested according to GB/T 9272-2007.

Viscosity: According to GB/T 9269-2009, at 25°C, use a Stormer viscometer (range 40-141KU) to measure viscosity, the unit is KU. If necessary, you can also use Brookfield rotational viscometer 6# rotor to test Brookfield viscosity at 25℃ and 30rpm. The unit is cp (or mPa.s).

Surface resistivity: According to GB/T 1410-2006, measure the resistivity of the sample surface at 23±2℃ and 50±5% relative humidity.

Hot water resistance: According to GB 9274-1988, place the sample in hot water at 95°C continuously. After continuing to soak for 240 hours, take out the sample and observe whether there are blistering, cracking, falling off and other bad conditions.

Salt spray resistance: According to GB/T 1771-2007, conduct salt spray for 1000 hours and observe whether there are blistering, cracking, falling off and other bad conditions.

Anti-corrosion performance: According to GB 9274-1988, as needed, place the sample in 5% sulfuric acid for 720h, 5% sodium hydroxide for 720h, 5% sodium chloride for 720h, or 60°C crude oil for 720h, and then take out the sample. Observe whether there are blistering, cracking, peeling and other bad conditions.

Example 1

The two-component coating composition of Example 1 was prepared.

(1) Preparation of component A: Add 0.2 parts of conductive filler TUBALL MATRIX from OCSiAl to 34.0 parts of epoxy resin (epoxy resin YD-128 and YDPN-638X80 from Guodu Chemical, weight ratio 10:1) 301, stir to disperse the conductive filler evenly. Then, under stirring, add 10.0 parts of titanium dioxide, 25.0 parts of talc with an average particle size of 1250 mesh, 23.0 parts of barium sulfate, 1.3 parts of additives, 0.5 parts of silane coupling agent A-187 and 6.0 parts of solvent. After uniform dispersion, component A is obtained. The viscosity of component A at 25°C is 105.4KU.

(2) Preparation of component B: Add 2 parts of solvent to 98 parts of alicyclic amine curing agent JH 5933 purchased from Jiadida New Materials, and disperse evenly to form component B.

(3) Mix component A and component B in a volume ratio of 4:1.

The resulting paint is applied to the steel plate and cured. Testing the coating performance, it was found that the volume solid content of the coating was 79%, the surface resistivity reached 10 ⁸ Ω, the paint film could be immersed in hot water at 95°C for 240 hours without blistering, and the paint film had no blistering in the 1000h salt spray test, 5% The paint film will not bubble when soaked in sulfuric acid for 720 hours, the paint film will not bubble when soaked in 5% sodium hydroxide for 720 hours, the paint film will not bubble when soaked in 5% sodium chloride for 720 hours, and the paint film will not bubble when soaked in crude oil at 60°C for 720 hours. Moreover, after being soaked in hot water at 95°C for 240 hours, the adhesion of the paint on the steel plate surface is still as high as 14.86MPa.

Example 2

The two-component coating composition in Example 2 was prepared.

(1) Preparation of component A: Add 0.15 parts of conductive filler TUBALL MATRIX 301 to 28.0 parts of epoxy resin (YD-128 and Epalloy 8240, weight ratio 2:1), stir, Make the conductive filler disperse evenly. Then, under stirring, add 6.0 parts of titanium dioxide, 11.9 parts of talc powder with an average particle size of 425 mesh, 23.65 parts of quartz powder, 17.0 parts of wollastonite powder, 2.0 parts of BC-C10 conductive mica powder from Junjiang, 1.3 parts of additives, 0.5 parts of silane coupling agent A-187 and 9.5 parts of solvent. After uniform dispersion, component A is obtained. The viscosity of component A at 25°C is 117.0KU.

(2) Preparation of component B: Add 20 parts of ARADUR 265-1 curing agent to 80 parts of alicyclic amine curing agent JH 5933, and disperse evenly to form component B.

(3) Mix component A and component B in a volume ratio of 4:1.

The resulting paint is applied to the steel plate and cured. Testing the coating performance, it was found that the volume solid content of the coating was 80.7%, the surface resistivity reached 10 ⁹ Ω, the paint film could be immersed in hot water at 95°C for 240 hours without blistering, and the paint film had no blistering in the 1000h salt spray test, 5% The paint film will not bubble when soaked in sulfuric acid for 720 hours, the paint film will not bubble when soaked in 5% sodium hydroxide for 720 hours, the paint film will not bubble when soaked in 5% sodium chloride for 720 hours, and the paint film will not bubble when soaked in crude oil at 60°C for 720 hours.

Example 3

Repeat Example 1, but replace the barium sulfate with quartz powder. The measured surface resistivity reached 10 ⁸ Ω.

Example 4

Example 1 was repeated but no silane coupling agent was added. The coating did not blister when soaked in 95°C hot water for 144 hours, but blistered obviously after 240 hours.

Example 5

Repeat Example 1, but add 1 part of silane coupling agent. When the coating is soaked in hot water at 95°C for 1000 hours, the paint film will not blister.

Example 6

In order to test the influence of pigments and fillers of different fineness on the conductive properties, in Example 6-1, Example 1 was repeated, but 0.125 parts of carbon nanotubes and 1250 mesh talc were used. In Example 6-2, Example 1 is repeated, but 0.125 parts of carbon nanotubes and 425 mesh talc are used. The surface resistivity of the cured paint film was measured and found to be 10 ¹² Ω in Example 6-1 and 10 ⁹ Ω in Example 6-2.

Comparative example 1

Commercially available Tankgaurd NCV electrostatically conductive two-component paint was used. The paint is applied to the steel panel and allowed to cure. The coating performance was tested and it was found that the surface resistivity reached 10 ¹¹ Ω. There was no blistering when immersed in hot water at 95°C for 48-96 hours, but the coating blistered obviously after 120 hours of immersion. The paint film did not blister during the 1000h salt spray test and was soaked in 5% sulfuric acid. The paint film does not blister after 720h soaking in 5% sodium hydroxide, the paint film does not blister when soaked in 5% sodium chloride for 720h, and the paint film does not blister when soaked in 60℃ crude oil for 720h.

Comparative example 2

Example 1 is repeated, but 23 parts of conductive mica are used instead of 23 parts of barium sulfate. The viscosity of the obtained component A at 25°C exceeded the maximum measurement value of the Stormer viscometer (greater than 140KU), and the viscosity measured using a Brookfield rotational viscometer was 17070cP. In order to facilitate subsequent construction, a large amount of diluent needs to be added to adjust the appropriate viscosity.

Comparative example 3

Repeat Example 1, but do not add a silane coupling agent, and use a polyamide curing agent to replace the alicyclic amine curing agent. The coating was soaked in hot water at 95°C for 96 hours to bubble.

Comparative example 4

Example 1 was repeated, but no silane coupling agent was added, and cardanol curing agent was used instead of the alicyclic amine curing agent. The coating was soaked in hot water at 95°C for 144 hours and blistered slightly.

Comparative example 5

Example 1 was repeated, but no silane coupling agent was added, and aliphatic amine curing agent was used instead of alicyclic amine curing agent. The coating was soaked in hot water at 95°C for 96 hours to bubble.

Although this invention has been described with reference to a number of embodiments and examples, one of ordinary skill in the art will recognize, in light of this disclosure, that other embodiments may be devised. It will be readily apparent to those skilled in the art that variations may be made in the present invention without departing from the principles disclosed in the foregoing specification. For example, without departing from the principles disclosed in the foregoing specification, the technical solution obtained by combining multiple features or preferred modes described herein should be understood to belong to the content recorded herein. Unless otherwise specified in the claim, such changes are deemed to be included in the scope of the patent application. Accordingly, the embodiments detailed herein are illustrative only and are not intended to limit the scope of the invention, which is the full scope of the appended claims and any and all equivalents thereof.

A,a,B: components

Claims (17)

A two-component coating composition comprising component A and component B, characterized in that the component A contains at least one epoxy resin and at least one conductive filler, and the component B contains at least one alicyclic amine cured agent, Wherein, based on the total weight of the A component, the total amount of the conductive filler is 0.05-8 wt%, the viscosity of the A component at 25°C is less than 140KU, and The volume solid content of the two-component coating composition is greater than 60%. The two-component coating composition according to claim 1, wherein the surface resistivity of the cured paint film obtained after the A component and the B component are mixed and coated is 1×10 ² to 1×10 ¹¹ Ω. The two-component coating composition as claimed in claim 1, wherein the total amount of conductive mica powder and conductive barium sulfate in the A component does not exceed 5% by weight based on the total weight of the A component. The two-component coating composition according to claim 1, wherein the conductive filler at least contains conductive carbon black, acetylene black, conductive mica powder, graphite, graphene, Ketjen black, carbon nanofibers, carbon nanoparticles One or more conductive fillers selected from the group consisting of conductive barium sulfate and conductive titanium dioxide. The two-component coating composition of claim 4, wherein the conductive filler includes single-walled carbon nanotubes with an aspect ratio of at least 1500:1. The two-component coating composition according to any one of claims 1 to 5, wherein the at least one epoxy resin includes novolac epoxy resin, bisphenol A epoxy resin or a combination of the two. The two-component coating composition of claim 6, wherein the at least one epoxy resin includes bisphenol A epoxy resin with an epoxy equivalent of less than 300 g/eq and phenolic resin with an epoxy equivalent of less than 300 g/eq. Epoxy resin. The two-component coating composition as claimed in claim 6 or 7, wherein the weight ratio of bisphenol A epoxy resin and novolac epoxy resin is 1:1 to 10:1. The two-component coating composition according to any one of claims 1 to 5, wherein, The two-component coating composition also includes a silane coupling agent. The two-component coating composition according to claim 9, wherein the silane coupling agent is an epoxy silane coupling agent. The two-component coating composition according to any one of claims 1 to 5, wherein the A component includes one of talc powder, quartz powder, barium sulfate, and wollastonite powder with a particle size of 100 mesh to 1500 mesh. or more. The two-component coating composition according to any one of claims 1 to 5, wherein the volume ratio of the A component to the B component is 1:1 to 10:1. The two-component coating composition according to any one of claims 1 to 5, wherein, based on the total weight of the A component, the A component includes: 25-45% by weight epoxy resin, 0.1-2% by weight conductive filler, 40-70% by weight of pigments and fillers, 0.2-2% by weight silane coupling agent, 0-15% by weight of organic solvent. A method for preparing the two-component coating composition as described in any one of claims 1 to 13, comprising: Mix component A and component B, Wherein, the A component includes at least one epoxy resin and at least one conductive filler, and the B component includes at least one alicyclic amine curing agent, Wherein, based on the total weight of the A component, the total amount of the conductive filler is 0.05-8 wt%, the viscosity of the A component at 25°C is less than 140KU, and The volume solid content of the two-component coating composition is greater than 60%. A coated product, characterized in that the coated product contains: A metallic substrate having at least one major surface; and The two-component coating composition according to any one of claims 1 to 13 or its cured coating coated on the at least one major surface of the metallic substrate. The coated product according to claim 15, wherein the metallic substrate includes an iron substrate, an aluminum substrate, carbon steel or stainless steel. The coated article of claim 15 or 16, wherein the cured coating of the coated article has a surface resistance of 10 ⁷ to 10 ¹¹ Ω, and does not blister when tested in hot water at 95°C for 240 hours, and in salt spray In the test, there is no foaming for 1000 hours, no foaming for 720 hours when soaked in 5% sulfuric acid solution, no foaming for 720 hours when soaked in 5% sodium hydroxide solution, and no foaming for 720 hours when soaked in 5% sodium chloride solution. , no foaming when soaked in 60℃ crude oil for 720 hours.