阅读说明：本技术 一种耐腐蚀环氧树脂涂料及其制备方法 (Corrosion-resistant epoxy resin coating and preparation method thereof ) 是由 费邦忠 胡先海 查全达 王平 于 2021-09-14 设计创作，主要内容包括：本发明涉及一种耐腐蚀环氧树脂涂料及其制备方法,属于涂料技术领域,该涂料包括如下原料：环氧树脂、改性剂、聚酯、高光钡、流平剂、脱气剂、促进剂、颜料、助剂；制备方法如下：按重量份将各原料混合均匀；然后通过螺杆挤出机熔融挤出,压片,粉碎,过筛；本发明制得的耐腐蚀环氧树脂涂料中添加了一种改性剂,将改性剂嵌入固化交联网络中,提高了涂料的抗冲击性能,改性剂中也含有大量的硅氧烷键和C-F键,同时具备有机硅与有机氟化合物的优点,提高了耐腐蚀环氧树脂涂料的耐水耐油、防腐蚀、耐老化等性能；更加稳定,助剂和改性剂中均含有键能较高C-F键,相比与传统的固化剂,其稳定性更好。(The invention relates to a corrosion-resistant epoxy resin coating and a preparation method thereof, belonging to the technical field of coatings, wherein the coating comprises the following raw materials: epoxy resin, a modifier, polyester, high-gloss barium, a flatting agent, a degassing agent, an accelerator, pigment and an auxiliary agent; the preparation method comprises the following steps: uniformly mixing the raw materials in parts by weight; then melt-extruding through a screw extruder, tabletting, crushing and sieving; the modifier is added into the corrosion-resistant epoxy resin coating prepared by the invention, and is embedded into a curing crosslinking network, so that the impact resistance of the coating is improved, the modifier also contains a large amount of siloxane bonds and C-F bonds, and has the advantages of organic silicon and organic fluorine compounds, and the water resistance, oil resistance, corrosion resistance, aging resistance and the like of the corrosion-resistant epoxy resin coating are improved; the curing agent is more stable, and the auxiliary agent and the modifier both contain C-F bonds with higher bond energy, so that the stability is better compared with the traditional curing agent.)

1. The corrosion-resistant epoxy resin coating comprises the following raw materials in parts by weight: 22-23 parts of epoxy resin, 10-15 parts of modifier, 32-33 parts of polyester, 28-29 parts of high-gloss barium, 0.8-0.9 part of flatting agent, 0.2-0.3 part of degassing agent, 0.05-0.07 part of accelerator, 1-1.2 parts of pigment and 5-8 parts of auxiliary agent; the method is characterized in that the modifier is prepared by the following steps:

stirring and mixing the additive, triethanolamine and epoxy chloropropane, adding a sodium hydroxide solution, carrying out reflux reaction for 4 hours after the addition is finished, cooling to room temperature after the reaction is finished, removing a water layer, washing an organic phase for 3 times by using saturated salt solution and deionized water respectively, and carrying out vacuum drying at 80 ℃ to constant weight after the washing is finished to obtain the modifier.

2. The corrosion-resistant epoxy resin paint as claimed in claim 1, wherein the concentration of the sodium hydroxide solution is 1mol/L, and the ratio of the additive, triethanolamine, epichlorohydrin and the sodium hydroxide solution is 8 g: 5 g: 30mL of: 40 mL.

3. The corrosion-resistant epoxy resin coating of claim 1, wherein the additive is prepared by:

step A11, mixing 3-fluoro-4- (hydroxymethyl) phenol, acrylic acid and p-toluenesulfonic acid, adding benzene and hydroquinone, and heating and refluxing for 8 hours at 80 ℃ to obtain an unsaturated monomer a;

and A12, mixing the unsaturated monomer a and ether, adding isopropanol-platinum, heating to 90 ℃, stirring to react for 8 hours, then slowly dropwise adding tetramethyldisiloxane into the mixture, and reacting at constant temperature for 24 hours after complete dropwise addition to obtain the additive.

4. The corrosion-resistant epoxy resin coating of claim 3, wherein the amount ratio of 3-fluoro-4- (hydroxymethyl) phenol, acrylic acid, p-toluenesulfonic acid, benzene and hydroquinone in step A11 is 7 g: 8mL of: 8 g: 8 g: 0.2 g; in the step A12, the dosage ratio of the unsaturated monomer a to the diethyl ether to the isopropanol-platinum to the tetramethyldisiloxane is 2 g: 20mL of: 0.4 g: 1.5 g.

5. The corrosion-resistant epoxy resin coating according to claim 1, wherein the auxiliary is prepared by the steps of:

step S11, mixing hydroquinone, 2-chloro-5-nitrobenzotrifluoride, potassium carbonate and N, N-dimethylformamide, heating to 80 ℃, and stirring for reacting for 4 hours to obtain an intermediate 1;

step S12, mixing the intermediate 1, stannous chloride and ethanol solution, adding hydrochloric acid solution while stirring, and carrying out reflux reaction for 20 hours to obtain an intermediate 2;

and step S13, mixing chlorinated trimellitic anhydride and pyridine, adding tetrahydrofuran, adding the intermediate 2 at the temperature of 0 ℃, and reacting at the temperature of 40 ℃ for 12 hours to obtain the assistant.

6. The corrosion-resistant epoxy resin coating as claimed in claim 5, wherein the molar ratio of the hydroquinone, the 2-chloro-5-nitrobenzotrifluoride and the potassium carbonate in step S11 is 1: 2: 2; the dosage ratio of hydroquinone to N, N-dimethylformamide is 1 g: 50 mL; in the step S12, the concentration of the hydrochloric acid solution is 1mol/L, the volume fraction of the ethanol solution is 95%, and the dosage ratio of the intermediate 1, stannous chloride, the ethanol solution and the hydrochloric acid solution is 2.4 g: 5.8 g: 50mL of: 4g of the total weight of the mixture; the dosage ratio of the chlorinated trimellitic anhydride, the pyridine and the intermediate 2 in the step S13 is 0.01 mol: 0.01 mol: 2.2 mL; the dosage ratio of the intermediate 2 to the tetrahydrofuran is 1 g: 50 mL.

7. The corrosion-resistant epoxy resin coating according to claim 1, wherein the leveling agent is polydimethylsiloxane; the degassing agent is benzoin; the accelerant is one of dimethyl imidazole and phenylcarbamoyl imidazole; the pigment is one of titanium dioxide, carbon black, peach red, ultramarine or phthalocyanine blue.

8. The method for preparing the corrosion-resistant epoxy resin coating according to claim 1, comprising the steps of:

uniformly mixing the raw materials in parts by weight; then melt-extruding through a screw extruder, and controlling the temperature of a charging section to be 60 ℃, the temperature of a melting section to be 98 ℃ and the temperature of a discharging section to be 110 ℃; tabletting the molten material with a tabletting machine, controlling the thickness to be 2-3mm, crushing, feeding into a flour mill, crushing, and sieving with a 200-mesh sieve.

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to a corrosion-resistant epoxy resin coating and a preparation method thereof.

Background

The metal material is damaged by the action of the surrounding medium, which is called metal corrosion. The corrosion of metal can obviously reduce the mechanical properties of the metal material, such as strength, plasticity, toughness and the like, destroy the geometric shape of a metal member, increase the abrasion among parts, deteriorate the physical properties of electricity, optics and the like, and shorten the service life of equipment. The conventional anticorrosion measure is to coat a layer of anticorrosion paint on the surface of the metal to isolate the metal from air, so as to achieve the anticorrosion effect.

Anticorrosive coatings are generally classified into conventional anticorrosive coatings and heavy anticorrosive coatings. The heavy-duty anticorrosive coating is an anticorrosive coating which can be applied in a relatively severe corrosive environment compared with a conventional anticorrosive coating and has a longer protection period than the conventional anticorrosive coating. In the field of heavy-duty anticorrosive coatings, epoxy resin powder coatings have the problems of poor ultraviolet resistance, easy yellowing, falling off, poor durability of anticorrosive effect and the like.

Disclosure of Invention

The invention aims to provide a corrosion-resistant epoxy resin coating and a preparation method thereof.

The purpose of the invention can be realized by the following technical scheme:

the corrosion-resistant epoxy resin coating comprises the following raw materials in parts by weight: 22-23 parts of epoxy resin, 10-15 parts of modifier, 32-33 parts of polyester, 28-29 parts of high-gloss barium, 0.8-0.9 part of flatting agent, 0.2-0.3 part of degassing agent, 0.05-0.07 part of accelerator, 1-1.2 parts of pigment and 5-8 parts of auxiliary agent;

the modifier is prepared by the following steps:

stirring and mixing the additive, triethanolamine and epoxy chloropropane, adding a sodium hydroxide solution, carrying out reflux reaction for 4 hours after the addition is finished, cooling to room temperature after the reaction is finished, removing a water layer, washing an organic phase for 3 times by using saturated salt solution and deionized water respectively, and carrying out vacuum drying at 80 ℃ to constant weight after the washing is finished to obtain the modifier. The modifier is prepared by taking an additive as a bisphenol monomer and triethanolamine as a branched monomer, adding epoxy chloropropane to perform condensation reaction under an alkaline condition, embedding the modifier into a curing crosslinking network, so that the impact resistance of the coating is improved. The additive also contains C-F bonds which have higher bond energy and are difficult to be damaged by light, heat and chemical factors, the additive has the advantages of organic silicon and organic fluorine compounds, and simultaneously has excellent performances of water resistance, oil resistance, corrosion resistance, aging resistance and the like, and when the polymer is used for modifying epoxy resin, the chemical properties of the epoxy resin polymer can be more stable, and the waterproof effect is improved.

Further, the concentration of the sodium hydroxide solution is 1mol/L, and the dosage ratio of the additive, the triethanolamine, the epichlorohydrin and the sodium hydroxide solution is 8 g: 5 g: 30mL of: 40 mL.

Further, the additive is prepared by the following steps:

step A11, mixing 3-fluoro-4- (hydroxymethyl) phenol, acrylic acid and p-toluenesulfonic acid, adding benzene and hydroquinone, heating and refluxing for 8 hours at 80 ℃, adding benzene and deionized water for extraction after the reaction is finished, neutralizing and washing an organic layer by using a sodium hydroxide solution with the mass fraction of 15%, decoloring active carbon, adding a polymerization inhibitor p-hydroxyanisole, carrying out reduced pressure distillation, and removing a solvent to obtain an unsaturated monomer a;

and A12, mixing the unsaturated monomer a and ether, adding isopropanol-platinum, heating to 90 ℃, stirring to react for 8 hours, then slowly dropwise adding tetramethyldisiloxane into the mixture, and reacting at constant temperature for 24 hours after complete dropwise addition to obtain the additive. The reaction process is as follows:

further, in step A11, the ratio of the amounts of 3-fluoro-4- (hydroxymethyl) phenol, acrylic acid, p-toluenesulfonic acid, benzene and hydroquinone was 7 g: 8mL of: 8 g: 8 g: 0.2 g; in the step A12, the dosage ratio of the unsaturated monomer a to the diethyl ether to the isopropanol-platinum to the tetramethyldisiloxane is 2 g: 20mL of: 0.4 g: 1.5 g.

Further, the auxiliary agent is prepared by the following steps:

step S11, mixing hydroquinone, 2-chloro-5-nitrobenzotrifluoride, potassium carbonate and N, N-dimethylformamide, heating to 80 ℃, and stirring for reacting for 4 hours to obtain an intermediate 1;

the reaction process is as follows:

step S12, mixing the intermediate 1, stannous chloride and ethanol solution, adding hydrochloric acid solution while stirring, and carrying out reflux reaction for 20 hours to obtain an intermediate 2;

and step S13, mixing chlorinated trimellitic anhydride and pyridine, adding tetrahydrofuran, adding the intermediate 2 at the temperature of 0 ℃, and reacting at the temperature of 40 ℃ for 12 hours to obtain the assistant. The auxiliary agent is an anhydride curing agent, and the auxiliary agent and the additive all contain C-F bonds, so that the stability is stronger, and the application range of the auxiliary agent is improved.

Further, in the step S11, the molar ratio of the hydroquinone to the 2-chloro-5-nitrobenzotrifluoride to the potassium carbonate is 1: 2: 2; the dosage ratio of hydroquinone to N, N-dimethylformamide is 1 g: 50 mL; in the step S12, the concentration of the hydrochloric acid solution is 1mol/L, the volume fraction of the ethanol solution is 95%, and the dosage ratio of the intermediate 1, stannous chloride, the ethanol solution and the hydrochloric acid solution is 2.4 g: 5.8 g: 50mL of: 4g of the total weight of the mixture; the dosage ratio of the chlorinated trimellitic anhydride, the pyridine and the intermediate 2 in the step S13 is 0.01 mol: 0.01 mol: 2.2 mL; the dosage ratio of the intermediate 2 to the tetrahydrofuran is 1 g: 50 mL.

Further, the leveling agent is polydimethylsiloxane;

the degassing agent is benzoin;

the accelerant is one of dimethyl imidazole and phenylcarbamoyl imidazole;

the pigment is one of titanium dioxide, carbon black, peach red, ultramarine or phthalocyanine blue.

A preparation method of the corrosion-resistant epoxy resin coating comprises the following steps:

uniformly mixing the raw materials in parts by weight; then melt-extruding through a screw extruder, and controlling the temperature of a charging section to be 60 ℃, the temperature of a melting section to be 98 ℃ and the temperature of a discharging section to be 110 ℃; tabletting the molten material with a tabletting machine, controlling the thickness to be 2-3mm, crushing, feeding into a flour mill, crushing, and sieving with a 200-mesh sieve.

The invention has the beneficial effects that:

the modifier is added into the corrosion-resistant epoxy resin coating prepared by the invention, and is embedded into a curing crosslinking network, so that the impact resistance of the coating is improved, the modifier also contains a large amount of siloxane bonds and C-F bonds, and has the advantages of organic silicon and organic fluorine compounds, and the water resistance, oil resistance, corrosion resistance, aging resistance and the like of the corrosion-resistant epoxy resin coating are improved; the curing agent is more stable, and the auxiliary agent and the modifier both contain C-F bonds with higher bond energy, so that the curing agent has better stability and better synergistic effect compared with the traditional curing agent.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Preparing an additive:

step A11, mixing 3-fluoro-4- (hydroxymethyl) phenol, acrylic acid and p-toluenesulfonic acid, adding benzene and hydroquinone, heating and refluxing for 8 hours at 80 ℃, adding benzene and deionized water for extraction after the reaction is finished, neutralizing and washing an organic layer by using a sodium hydroxide solution with the mass fraction of 15%, decoloring active carbon, adding a polymerization inhibitor p-hydroxyanisole, carrying out reduced pressure distillation, and removing a solvent to obtain an unsaturated monomer a; wherein the dosage ratio of the 3-fluoro-4- (hydroxymethyl) phenol to the acrylic acid to the p-toluenesulfonic acid to the benzene to the hydroquinone is 7 g: 8mL of: 8 g: 8 g: 0.2 g;

step A12, mixing an unsaturated monomer a and diethyl ether, adding isopropanol-platinum, heating to 90 ℃, stirring to react for 8 hours, then slowly dropwise adding tetramethyldisiloxane into the mixture, and reacting at constant temperature for 24 hours after complete dropwise addition to obtain an additive; wherein the dosage ratio of the unsaturated monomer a to the diethyl ether to the isopropanol-platinum to the tetramethyldisiloxane is 2 g: 20mL of: 0.4 g: 1.5 g.

Example 2

Preparing a modifier:

stirring and mixing the additive, triethanolamine and epoxy chloropropane, then adding a sodium hydroxide solution, carrying out reflux reaction for 4 hours after the addition is finished, cooling to room temperature after the reaction is finished, removing a water layer, washing an organic phase for 3 times by using saturated salt solution and deionized water respectively, and carrying out vacuum drying at 80 ℃ to constant weight after the washing is finished to obtain a modifier; wherein the concentration of the sodium hydroxide solution is 1mol/L, and the dosage ratio of the additive, the triethanolamine, the epichlorohydrin and the sodium hydroxide solution is 8 g: 5 g: 30mL of: 40 mL; the additive was prepared as in example 1.

Example 3

Preparing an auxiliary agent:

step S11, mixing hydroquinone, 2-chloro-5-nitrobenzotrifluoride, potassium carbonate and N, N-dimethylformamide, heating to 80 ℃, and stirring for reacting for 4 hours to obtain an intermediate 1; wherein the molar ratio of the hydroquinone to the 2-chloro-5-nitrobenzotrifluoride to the potassium carbonate is 1: 2: 2; the dosage ratio of hydroquinone to N, N-dimethylformamide is 1 g: 50 mL;

step S12, mixing the intermediate 1, stannous chloride and ethanol solution, adding hydrochloric acid solution while stirring, and carrying out reflux reaction for 20 hours to obtain an intermediate 2; wherein the concentration of the hydrochloric acid solution is 1mol/L, the volume fraction of the ethanol solution is 95%, and the dosage ratio of the intermediate 1, stannous chloride, the ethanol solution and the hydrochloric acid solution is 2.4 g: 5.8 g: 50mL of: 4g of the total weight of the mixture;

step S13, mixing chlorinated trimellitic anhydride and pyridine, adding tetrahydrofuran, adding the intermediate 2 at the temperature of 0 ℃, and reacting at the temperature of 40 ℃ for 12 hours to obtain an auxiliary agent; wherein the dosage ratio of the chlorinated trimellitic anhydride to the pyridine to the intermediate 2 is 0.01 mol: 0.01 mol: 2.2 mL; the dosage ratio of the intermediate 2 to the tetrahydrofuran is 1 g: 50 mL.

Example 4

A preparation method of the corrosion-resistant epoxy resin coating comprises the following steps:

uniformly mixing the following raw materials in parts by weight: 22 parts of epoxy resin, 10 parts of modifier, 32 parts of polyester, 28 parts of high-gloss barium, 0.8 part of flatting agent, 0.2 part of degassing agent, 0.05 part of accelerator, 1 part of pigment and 5 parts of assistant;

melting and extruding through a screw extruder, and controlling the temperature of a feeding section to be 60 ℃, the temperature of a melting section to be 98 ℃ and the temperature of a discharging section to be 110 ℃; and tabletting the molten material by a tabletting machine, controlling the thickness to be 2mm, crushing the molten material, feeding the crushed molten material into a grinding mill, crushing the crushed molten material, and sieving the crushed molten material by a 200-mesh sieve.

Wherein, the flatting agent is polydimethylsiloxane; the degassing agent is benzoin; the accelerant is dimethyl imidazole; the pigment is titanium dioxide; the modifier was prepared as in example 2; the adjuvant was prepared as in example 3.

Example 5

A preparation method of the corrosion-resistant epoxy resin coating comprises the following steps:

uniformly mixing the following raw materials in parts by weight: 22 parts of epoxy resin, 12 parts of modifier, 32 parts of polyester, 28 parts of high-light barium, 0.8 part of flatting agent, 0.2 part of degassing agent, 0.06 part of accelerator, 1.1 parts of pigment and 6 parts of auxiliary agent;

melting and extruding through a screw extruder, and controlling the temperature of a feeding section to be 60 ℃, the temperature of a melting section to be 98 ℃ and the temperature of a discharging section to be 110 ℃; and tabletting the molten material by a tabletting machine, controlling the thickness to be 2mm, crushing the molten material, feeding the crushed molten material into a grinding mill, crushing the crushed molten material, and sieving the crushed molten material by a 200-mesh sieve.

Wherein, the flatting agent is polydimethylsiloxane; the degassing agent is benzoin; the accelerant is dimethyl imidazole; the pigment is titanium dioxide; the modifier was prepared as in example 2; the adjuvant was prepared as in example 3.

Example 6

A preparation method of the corrosion-resistant epoxy resin coating comprises the following steps:

uniformly mixing the following raw materials in parts by weight: 23 parts of epoxy resin, 15 parts of modifier, 33 parts of polyester, 29 parts of high-gloss barium, 0.9 part of flatting agent, 0.3 part of degassing agent, 0.07 part of accelerator, 1.2 parts of pigment and 8 parts of assistant;

melting and extruding through a screw extruder, and controlling the temperature of a feeding section to be 60 ℃, the temperature of a melting section to be 98 ℃ and the temperature of a discharging section to be 110 ℃; and tabletting the molten material by a tabletting machine, controlling the thickness to be 3mm, crushing, feeding into a grinding machine for crushing, and sieving by a 200-mesh sieve.

Wherein, the flatting agent is polydimethylsiloxane; the degassing agent is benzoin; the accelerant is phenylcarbamyl imidazole; the pigment is titanium dioxide; the modifier was prepared as in example 2; the adjuvant was prepared as in example 3.

Comparative example 1

Compared with the example 5, the modifier is not added, and the rest raw materials and the preparation process are kept unchanged.

Comparative example 2

The auxiliary in example 5 was replaced by dicyandiamide, the remaining raw materials and the preparation process were kept unchanged.

The powder coatings prepared in examples 4-6 and comparative examples 1-2 were electrostatically sprayed on a rust-removing and oil-removing cold-rolled steel plate with a thickness of 1.0mm by a corona spray gun, and then baked at 180 ℃ for 20min, with a coating thickness of 70 μm + -3 μm, and tested for salt spray resistance for 480h and 1000h according to the standard GB/T1771-2007; testing the water resistance for 1000h according to the standard GB/T1733-93; impact resistance according to standard GBT 1732-1993; testing the ultraviolet accelerated aging resistance time according to the standard GB/T23987-2009; the test results are shown in table 1 below:

TABLE 1

	Salt spray resistance of 480h	Salt fog resistance of 1000h	Impact resistance	When aging resistantWorkshop
					Example 4	No cracking and no foaming	No blister and no blushing	73.0cm	>1600h
Example 5	No cracking and no foaming	No blister and no blushing	73.3cm	>1600h
					Example 6	No cracking and no foaming	No blister and no blushing	73.1cm	>1600h
Comparative example 1	Cracking blister	Whitening and peeling	51.1cm	<1000h
					Comparative example 2	Cracking blister	Whitening and peeling	65.6cm	<1000h

As can be seen from the above Table 1, the corrosion-resistant epoxy resin coating prepared by the invention has better water resistance, oil resistance, corrosion resistance, aging resistance and the like, and has more stable performance.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.