CN107090232B

CN107090232B - Micromolecular organic acid-resistant anticorrosive paint and preparation method thereof

Info

Publication number: CN107090232B
Application number: CN201710474305.XA
Authority: CN
Inventors: 李至秦; 魏金伯; 杨名亮; 康瑞瑞
Original assignee: XIAMEN SHUANGRUI SHIPBUILDING PAINT CO Ltd
Current assignee: XIAMEN SHUANGRUI SHIPBUILDING PAINT CO Ltd
Priority date: 2017-06-21
Filing date: 2017-06-21
Publication date: 2020-02-04
Anticipated expiration: 2037-06-21
Also published as: CN107090232A

Abstract

The invention provides a micromolecular organic acid-resistant anticorrosive paint and a preparation method thereof, wherein the micromolecular organic acid-resistant anticorrosive paint is mainly prepared from the following raw materials in parts by weight: a component A: 23.4-41.7 parts of phenolic epoxy resin, 6.6-8.3 parts of liquid polysulfide rubber, 3-7 parts of active diluent, 0.1-1 part of dispersant, 0.2-0.8 part of defoamer, 0.1-0.3 part of nano-silica, 0.1-0.3 part of silica surface modifier, 0.05-0.1 part of silica surface modifier, 4.7-5.6 parts of solvent, 22.5-47.5 parts of filler, 1-2 parts of thixotropic agent and 8-12 parts of diluent; b, component B: and (3) an amine curing agent. The micromolecular organic acid-resistant anticorrosive paint provided by the invention has excellent organic acid resistance and oil resistance.

Description

Micromolecular organic acid-resistant anticorrosive paint and preparation method thereof

Technical Field

The invention relates to the technical field of coatings, and particularly relates to a micromolecular organic acid-resistant anticorrosive coating and a preparation method thereof.

Background

The prior art coatings are generally able to withstand attack by bases, salts and some low concentrations of inorganic acids, while the coatings are relatively less resistant to small molecule organic acids. The small molecular organic acid has strong corrosion and destruction effects on metal and coatings, because the small molecular organic acid is used as an organic substance and can be dissolved with the organic coating similarly to cause the swelling effect of the organic coating, thereby destroying the coating structure, and in addition, the small molecular organic acid is used as an acidic substance and is easy to promote the corrosion of a metal substrate. Products of domestic oil refineries, petrochemical plants and fine chemical plants inevitably contain small molecular organic acids such as phenol, acetic acid and the like, which have serious corrosion on storage tanks, pipelines and waste liquid pools, and the service life of the active novolac epoxy heavy anti-corrosion coating is difficult to meet the use requirement in the actual use process.

Wangwei and the like adopt titanium nano polymer coating to modify phenolic epoxy coating, and the time for resisting small molecular organic acid is improved from 1 month to 1.5 months. Mojun and the like modify a phenolic epoxy coating formula by adopting vinyl ester resin and glass flakes, and the resistance to small molecular organic acidity of the phenolic epoxy coating is improved from 1 month to 2 months. The Arfuwei adopts a nano material modified phenolic epoxy coating, and the soaking time of the Arfuwei is 2 months. Although the method improves the resistance of the coating to small molecular organic acid to a certain extent, the method still cannot achieve the ideal effect.

Disclosure of Invention

In order to solve the problems, the invention provides a micromolecular organic acid-resistant anticorrosive paint which is mainly prepared from the following raw materials in parts by weight:

a component A: 23.4-41.7 parts of phenolic epoxy resin, 6.6-8.3 parts of liquid polysulfide rubber, 3-7 parts of active diluent, 0.1-1 part of dispersant, 0.2-0.8 part of defoamer, 0.1-0.3 part of nano-silica, 0.1-0.3 part of silica surface modifier, 0.05-0.1 part of silica surface modifier, 4.7-5.6 parts of solvent, 22.5-47.5 parts of filler, 1-2 parts of thixotropic agent and 8-12 parts of diluent;

b, component B: an amine-based curing agent; the mass ratio of the component A to the component B in the micromolecule organic acid-resistant anticorrosive paint is 4-9: 1.

Further, the epoxy value of the novolac epoxy resin is 0.51.

Further, the molecular weight of the liquid polysulfide rubber is 1000-4000, and the molecular structural formula is HS- (C)₂H₄OCH₂OCH₂OC₂H₄-S-S-)_n-C₂H₄OCH₂O-C₂H₄-SH。

Further, the reactive diluent is propylene oxide phenyl ether; the dispersant is BYK 110; the defoaming agent is at least one of an organic silicon defoaming agent, silicone oil and an organic mineral defoaming agent.

Further, the defoaming agent comprises silicone oil, BYKA530, BYK023, BYK052, BYK053, BYK057 and BYK 077.

Furthermore, the nano silicon dioxide is a spherical structure with the particle size of 10 nm-100 nm.

Further, the silicon dioxide surface modifier comprises at least one of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane and gamma-methacryloxypropyltrimethoxysilane; the silica surface modifier comprises any one of BYK110, BYK112, BYK163, BYK180, BYK190 and BYK2010, or any two combinations of the above or at least one of the three combinations of the above.

Further, the solvent is at least one of n-butanol, ethanol, cyclohexanone, propylene glycol monomethyl ether acetate and acetone.

Further, the filler is at least one of talcum powder, barite powder, precipitated barium sulfate, mica powder, sericite powder, titanium dioxide, feldspar powder, glass flakes and wollastonite powder; the thixotropic agent is at least one of polyamide wax, polyethylene wax, organic bentonite and fumed silica; the diluent is a composition of xylene and n-butanol in a weight ratio of 7: 3; the amine curing agent is at least one of phenolic amine, fatty amine, modified fatty amine, alicyclic amine and modified alicyclic amine.

The invention also provides a preparation method of the micromolecule organic acid-resistant anticorrosive paint, which comprises the following steps:

s110: adding a silicon dioxide surface modifier and a silicon dioxide surface modifier into a solvent, mixing and stirring uniformly, adding nano silicon dioxide into the solvent, and performing ultrasonic dispersion uniformly to obtain a nano silicon dioxide pre-dispersion liquid;

s120: uniformly mixing the novolac epoxy resin and the liquid polysulfide rubber, dispersing for 60min at the speed of 3000-4000 rpm, stirring at the speed of 800-1000 rpm, adding the active diluent, the dispersing agent and the defoaming agent, and uniformly mixing and stirring;

s130: slowly adding the mixed liquid obtained in the step S120 into the nano silicon dioxide pre-dispersion liquid and dispersing for 20 min;

s140: adding a filler into the liquid obtained in the step S130, dispersing for 30-60 min at the speed of 3000-4000 rpm, and detecting the fineness to be less than or equal to 80 mu m; adding thixotropic agent and dispersing until it is in uniform state; then adding the diluent, and mixing and stirring uniformly;

s150: filtering to obtain a component A;

b, component B:

the amine curing agent is stirred and mixed evenly, and then the component B is obtained by filtering.

The micromolecule organic acid resistant anticorrosive paint provided by the invention achieves a synergistic effect by good matching of the novolac epoxy resin, the polysulfide rubber and the modified nano-silica, and improves the impermeability of the novolac epoxy paint to micromolecule organic acid corrosive media. The modified resin takes a rigid novolac epoxy resin network with high shielding property and high crosslinking density as a main structure, is supplemented with polysulfide rubber with good toughness and solvent resistance to increase the toughness of the resin, prevents the resin from cracking caused by internal stress, and is fixed into a three-dimensional network structure with a more compact structure through the hydrogen bonding effect of nano-silica. The modified resin is not a simple physical mixing process, but forms a new chemical bond function in the process, so that the structure of the modified resin is more uniform and stable, and the modified resin comprises the interaction of sulfydryl and epoxy groups in polysulfide rubber and novolac epoxy resin and the hydrogen bond function of silanol groups of nano silicon dioxide and resin hydroxyl and sulfydryl. The modification mode can improve the toughness of the novolac epoxy resin and reduce pores generated in the resin film forming process, thereby improving the impermeability of the resin to small molecular organic acid corrosive media.

The micromolecular organic acid-resistant anticorrosive paint provided by the invention has excellent organic acid resistance and oil resistance. The coating is used for long-acting heavy corrosion prevention of organic acid-containing storage tanks, pipelines and waste liquid pools in oil refineries, petrochemical plants and fine chemical plants, the strength and the shielding performance of the coating are greatly improved, the service life of steel structures and concrete structures in extreme corrosion environments is prolonged, and the equipment maintenance cost is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of the synthesis of the anti-corrosive paint with resistance to small molecular organic acid provided by the invention;

FIG. 2 is an infrared spectrum of a preferred embodiment of a small molecule organic acid resistant anticorrosive coating;

FIG. 3 is a scanning electron microscope image of a common novolac epoxy coating;

FIG. 4 is a scanning electron microscope image of a coating of the small molecule organic acid resistant anticorrosive paint.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. 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.

The invention is further illustrated by the following examples, tables 1 and 2 being the a component and the b component, respectively, of 3 preferred examples provided by the present invention.

TABLE 1

Serial number	A component	Example 1	Example 2	Example 3
					1	Novolac epoxy resin	23.4	41.7	32
2	Liquid polysulfide rubber	6.6	8.3	8
					3	Reactive diluent	5	7	3
4	Dispersing agent	0.3	0.1	1
					5	Defoaming agent	0.2	0.8	0.3
6	Nano silicon dioxide	0.1	0.3	0.2
					7	Silicon dioxide surface modifier	0.15	0.1	0.2
8	Silicon dioxide surface modifier	0.05	0.1	0.1
					9	Solvent(s)	4.7	5.6	5.2
10	Filler material	47.5	22.5	41
					11	Thixotropic agent	2	1.5	1
12	Diluent	10	12	8
					Serial number	Component B	Example 1	Example 2	Example 3
1	Amine curing agent	100	100	100

Wherein: the reactive diluents of example 1, example 2 and example 3 all used propylene oxide phenyl ether;

the dispersants in example 1, example 2 and example 3 all used BYK 110;

the defoamer in example 1 was silicone oil; the defoamer in example 2 was 0.3 part silicone oil, 0.3 part BYK023, 0.2 part BYKA 530; the defoamer in example 3 was 0.15 parts BYK053 and 0.15 parts BYK 077;

the silica surface modifier in example 1 was 0.05 parts gamma-aminopropyltriethoxysilane, 0.05 parts gamma- (2, 3-glycidoxy) propyltrimethoxysilane and 0.05 parts gamma-methacryloxypropyltrimethoxysilane; the silica surface modifier in example 2 was gamma-aminopropyltriethoxysilane; the silica surface modifier of example 2 is 0.1 parts gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane and 0.1 parts gamma-methacryloxypropyltrimethoxysilane;

the silica surface modifier in example 1 was 0.01 parts BYK110, 0.02 parts BYK112, and 0.02 parts BYK 163; the silica surface modifier in example 2 was 0.03 parts BYK163, 0.03 parts BYK190, and 0.04 parts BYK 2010; (ii) a The silica surface modifier of example 3 was synthesized by preferentially combining 0.03 parts of BYK180, 0.03 parts of a mixture of BYK190 and BYK2010 and 0.04 parts of a mixture of BYK110, BYK112 and BYK163, the mixture of BYK190 and BYK2010 was composed of 50% of BYK190 and 50% of BYK2010, and the silica surface modifier of example 2 was synthesized by preferentially combining 30% of BYK110, 30% of BYK112 and 40% of BYK 163;

the solvent in example 1 was 4.7 parts of n-butanol; the solvent in example 2 was 2.8 parts ethanol and 2.8 parts cyclohexanone; the solvents in example 3 were 1.7 parts of n-butanol, 1.7 parts of propylene glycol methyl ether acetate and 1.8 parts of acetone;

the filler in example 1 was 10 parts of talc powder, 10 parts of barite powder, 13 parts of precipitated barium sulfate and 14.5 parts of mica powder; the filler in example 2 is 11 parts of sericite powder and 11.5 parts of titanium dioxide; the filler in example 3 was 13 parts feldspar powder, 13 parts glass flake and 15 parts wollastonite powder;

the thixotropic agent in example 1 was 1 part of polyamide wax and 1 part of organobentonite; the thixotropic agent in example 2 is 1 part polyethylene wax and 0.5 part fumed silica; the thixotropic agent in example 3 is 1 part of a polyamide wax;

the diluents in the three examples are all the compositions of xylene and n-butanol according to the weight ratio of 7: 3;

the amine curing agent in example 1 was a phenolic amine; the amine curing agent in example 2 is a mixture of 50 parts of fatty amine and 50 parts of modified fatty amine; the amine curing agent in example 3 is a mixture of 50 parts of alicyclic amine and 50 parts of modified alicyclic amine.

The preparation method of the component A comprises the following steps: adding a silicon dioxide surface modifier and a silicon dioxide surface modifier into a solvent, mixing and stirring uniformly, adding nano silicon dioxide into the solvent, and performing ultrasonic dispersion uniformly to obtain a nano silicon dioxide pre-dispersion liquid; uniformly mixing the novolac epoxy resin and the liquid polysulfide rubber, and dispersing for 60min at the speed of 3500 rpm; stirring at the speed of 900rpm, adding the active diluent, the dispersing agent and the defoaming agent, and uniformly mixing and stirring; slowly adding the nano silicon dioxide pre-dispersion liquid and dispersing for 20 min; adding filler and dispersing at 3500rpm for 30-60 min, with the detection fineness less than or equal to 80 μm; adding thixotropic agent to disperse until it is in uniform state; adding the diluent, mixing and stirring uniformly, filtering and packaging to obtain a finished product;

the preparation method of the component B comprises the following steps: the amine curing agent is stirred and mixed evenly, and then the mixture is filtered and packaged to obtain a finished product.

The A/B component of example 1 was prepared as follows: b is 8: 1 (mass ratio), and the ethyl component of example 2 is as follows: and B is 5: 1 (mass ratio) and the A/B component of example 3 were as follows: b is 6: 1 (mass ratio), the test results are shown in table 2.

The comparative example was tested using a conventional novolac epoxy resin, and the test results are shown in table 2.

The performance test experiment base material is Q235 carbon steel, the steel plate with the size of 150mm multiplied by 75mm multiplied by 2mm, the steel plate is subjected to sand blasting treatment to the surface roughness St 2.5, the prepared coating is uniformly sprayed on the steel plate by adopting air spraying, the thickness of a dry film is controlled to be (300 +/-50) mu m, and the soaking experiment in different media is carried out according to the GB/T9274 standard.

TABLE 2

From the test results in table 2, it can be seen that the micromolecule organic acid soaking resistance of the micromolecule organic acid-resistant anticorrosive coating provided by the invention can meet the index requirements, while the micromolecule organic acid soaking resistance of the common novolac epoxy resin is relatively poor and cannot meet the index requirements.

According to the micromolecule organic acid resistant anticorrosive paint and the preparation method thereof, the synergistic effect is achieved through the good matching of the novolac epoxy resin, the polysulfide rubber and the modified nano-silica, the impermeability of the novolac epoxy paint to micromolecule organic acid corrosion media is improved, and the action mechanism is shown in figure 1. The modified resin takes a rigid novolac epoxy resin network with high shielding property and high crosslinking density as a main structure, is supplemented with polysulfide rubber with good toughness and solvent resistance to increase the toughness of the resin, prevents the resin from cracking caused by internal stress, and is fixed into a three-dimensional network structure with a more compact structure through the hydrogen bonding effect of nano-silica. The modified resin is not a simple physical mixing process, but forms a new chemical bond function in the process, so that the structure of the modified resin is more uniform and stable, and the modified resin comprises the interaction of sulfydryl and epoxy groups in polysulfide rubber and novolac epoxy resin and the hydrogen bond function of silanol groups of nano silicon dioxide and resin hydroxyl and sulfydryl. The modification mode can improve the toughness of the novolac epoxy resin and reduce pores generated in the resin film forming process, thereby improving the impermeability of the resin to small molecular organic acid corrosive media.

As can be seen from FIG. 2, 2561cm^-1The peak at (A) is an infrared characteristic peak of a mercapto group (-SH) and is found in curve b, while in curve c, the peak disappears, and in addition, 915cm after modification^-1The infrared characteristic peak of the epoxy group at (c) is also obviously weakened (the epoxy characteristic peak is weaker than a), which indicates that the resin modification reaction of the reaction of-SH and the epoxy group is successfully carried out.

As can be seen from the scanning results of fig. 3 and fig. 4, a large number of pore structures exist in the ordinary novolac epoxy coating (fig. 3), and the coating modified by polysulfide rubber and nano-silica (fig. 4) has a dense internal structure and no observable pore structures, which indicates that the crosslinking density of the overall structure of the modified coating is significantly increased, which results in an improved shielding property against corrosive media.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a micromolecular organic acid-resistant anticorrosive paint is characterized by comprising the following steps:

s110: adding a silicon dioxide surface modifier and a silicon dioxide surface modifier into a solvent, mixing and stirring uniformly, adding nano silicon dioxide into the solvent, and performing ultrasonic dispersion for 30-60 min to obtain a nano silicon dioxide pre-dispersion liquid;

s120: uniformly mixing the novolac epoxy resin and the liquid polysulfide rubber, dispersing for 50-70 min at the speed of 3000-4000 rpm, stirring at the speed of 800-1000 rpm, adding the active diluent, the dispersing agent and the defoaming agent, and stirring and dispersing for 10-15 min at the speed of 800-1000 rpm;

s130: slowly adding the mixed liquid obtained in the step S120 into the nano silicon dioxide pre-dispersion liquid to disperse for 15-30 min at the speed of 3000-4000 rpm;

s150: filtering to obtain a component A;

b, component B:

stirring and mixing the amine curing agent uniformly, and then filtering to obtain a component B;

the weight parts of the raw materials are as follows:

b, component B: an amine-based curing agent;

the mass ratio of the component A to the component B in the micromolecule organic acid-resistant anticorrosive paint is 4-9: 1.

2. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the epoxy value of the novolac epoxy resin is 0.51.

3. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the molecular weight of the liquid polysulfide rubber is 1000-4000, and the molecular structural formula is HS- (C)₂H₄OCH₂OCH₂OC₂H₄-S-S-)_n-C₂H₄OCH₂O-C₂H₄-SH。

4. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the active diluent is propylene oxide phenyl ether; the dispersant is BYK 110; the defoaming agent is at least one of an organic silicon defoaming agent, silicone oil and an organic mineral defoaming agent.

5. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the defoaming agent comprises silicone oil, BYKA530, BYK023, BYK052, BYK053, BYK057 and BYK 077.

6. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the nano silicon dioxide is in a spherical structure with the particle size of 10 nm-100 nm.

7. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the silicon dioxide surface modifier comprises at least one of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane and gamma-methacryloxypropyltrimethoxysilane; the silica surface modifier comprises any one of BYK110, BYK112, BYK163, BYK180, BYK190 and BYK2010, or any two combinations of the above or at least one of the three combinations of the above.

8. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the solvent is at least one of n-butyl alcohol, ethanol, cyclohexanone, propylene glycol methyl ether acetate and acetone.

9. The preparation method of the small-molecule organic acid-resistant anticorrosive paint according to claim 1, characterized in that: the filler is at least one of talcum powder, barite powder, precipitated barium sulfate, mica powder, sericite powder, titanium dioxide, feldspar powder, glass flakes and wollastonite powder; the thixotropic agent is at least one of polyamide wax, polyethylene wax, organic bentonite and fumed silica; the diluent is a composition of xylene and n-butanol in a weight ratio of 7: 3; the amine curing agent is at least one of phenolic amine, fatty amine, modified fatty amine, alicyclic amine and modified alicyclic amine.