WO2021237404A1

WO2021237404A1 - Aqueous epoxy anticorrosive coating and preparation method therefor

Info

Publication number: WO2021237404A1
Application number: PCT/CN2020/092083
Authority: WO
Inventors: 王胜龙; 温正明; 杨名亮; 吴培发
Original assignee: 厦门双瑞船舶涂料有限公司
Priority date: 2020-05-25
Filing date: 2020-05-25
Publication date: 2021-12-02
Also published as: CN113015771A; ZA202209631B

Abstract

Disclosed is an aqueous epoxy anticorrosive coating, comprising: component A and component B. Component A comprises aqueous epoxy resin A, aqueous epoxy resin B, a dispersant, a defoamer, a wetting agent, a thixotropic agent, an anti-flash agent, a pigment, a filler and deionized water, wherein aqueous epoxy resin A is a self-emulsifying aqueous epoxy resin, and aqueous epoxy resin B is a glycidyl ester epoxy resin. Component B comprises a curing agent and deionized water, wherein the curing agent is an amine curing agent. Further provided is a method for preparing the aqueous epoxy anticorrosive coating, the method comprising a specific mixing order and specific process parameters.

Description

Waterborne epoxy anticorrosive paint and preparation method thereof

Technical field

The invention relates to the technical field of chemical materials, in particular to a waterborne epoxy anticorrosive paint and a preparation method thereof.

Background technique

Water-based anticorrosive coatings with water as dispersion and resin as film-forming base material have the advantages of low VOC emissions, performance equivalent to solvent-based anticorrosive coatings, and low cost. It has become one of the development trends of environmentally friendly coatings in the future.

At present, most of the waterborne epoxy anticorrosive resins on the market are emulsion type, and the preparation process is generally: pre-grind the pigment and filler solution, and then disperse and mix with the emulsion at high speed; at the same time, the emulsion type waterborne epoxy also needs to add the film-forming auxiliary, which has a high boiling point. Solvent, assist the resin to cure into a film.

The above methods have the following shortcomings: (1) Pigments and fillers are pre-grinded, easy to precipitate without stirring, unstable storage, extremely inconvenient to use, increase the production process flow, and increase the cost; (2) Adding film-forming additives, the system VOC content The increase leads to an increase in organic volatiles, which is not environmentally friendly.

Chinese Patent Application CN 110183932 A "A Waterborne Epoxy Anticorrosive Coating Containing Composite Active Salt and Its Preparation Method", the publication date is August 30, 2020. In this technical proposal, the preparation method of component A is disclosed: Stir and mix the additives with deionized water, then add pigments and fillers and the prepared composite active phosphite/metaluminate, grind to the required fineness, prepare a resin-free emulsion slurry, and then mix it with water-based epoxy resin emulsion And thixotropic agent, stir evenly to obtain component A.

Chinese Patent Application CN 110643265 A "A Waterborne Epoxy Coating That Can Be Flowed and Dip Coated and Its Preparation Method", the publication date is January 3, 2020, in this technical solution, the A component includes the following mass percentages Component: 22%-25% bisphenol A type epoxy resin water-based dispersion, 8%-10% o-cresol novolac epoxy resin water-based dispersion, 0.8%-1% solvent, 1.5%-1.8% Dispersant, 0.1%-0.2% anti-settling agent, 0.8%-1% wetting and leveling agent, 0.4%-0.6% thickener, 0.6%-0.7% defoamer, 2%-20 % Titanium dioxide, 20%-40% filler and the balance of deionized water, which contains 0.8%-1% volatile solvent, the pigment in this scheme needs to be pre-grinded with a fineness of less than 20μm.

Summary of the invention

In order to solve the problems in the prior art that the pigments and fillers need to be pre-grinded and the film-forming auxiliary agent needs to be added; including:

Water-based epoxy resin A, water-based epoxy resin B, dispersant, defoamer, wetting agent, thixotropic agent, anti-flash agent, pigment, filler, deionized water;

Wherein, the water-based epoxy resin A is a self-emulsifying water-based epoxy resin;

The water-based epoxy resin B is a glycidyl ester epoxy resin;

The second component includes: curing agent and deionized water;

The curing agent is an amine curing agent.

On the basis of the above solution, further, the mass parts of each raw material in the first component are:

On the basis of the above solution, further, the mass parts of the raw materials in the second component are: 60 parts of curing agent and 40 parts of deionized water.

On the basis of the above solution, further, the solid content of the water-based epoxy resin A is 100%, which is selected from Foshan Tongde Chemical 3EE107B self-emulsifying water-based epoxy resin.

On the basis of the above solution, further, the solid content of the water-based epoxy resin B is 100%, and is selected from the group consisting of diglycidyl hexahydrophthalate, diglycidyl isophthalate, and diglycidyl adipic acid. One or two or more of glycidyl esters.

On the basis of the above solution, further, the thixotropic agent is at least one of water-based bentonite, water-based silicate, and organically modified hectorite clay.

On the basis of the above solution, further, the pigments and fillers are at least one of mica dust, composite iron titanium powder, mica powder, iron oxide red, talc powder, zinc phosphate, aluminum tripolyphosphate, feldspar powder, and titanium dioxide Three combinations.

On the basis of the above solution, further, the defoaming agent is selected from at least one of 180W, 182W, 280W, 282W, 285W, 290W, and 291W.

On the basis of the above solution, further, the dispersant is at least one of modified polyurethane, high molecular polymer, unsaturated carboxylic acid, and high molecular block polymer.

On the basis of the above solution, further, the dispersant is selected from at least one of Eucalyptus 520S, 560S, 650U, 685U, 690W, and 765S.

On the basis of the above solution, further, the wetting agent is at least one of organically modified polysiloxane, fluorocarbon modified silicone, functional acrylate, and fluorocarbon polymer.

On the basis of the above solution, further, the wetting agent is selected from at least one of Eucalyptus 430S, 470U, 375S, 360S, 361S, and 385S.

The present invention also provides a preparation method according to any of the above-mentioned water-based epoxy anticorrosive coatings, including:

Preparation method of component A:

S110. Add deionized water to the pull cylinder, add defoamer, dispersant, and wetting agent respectively, and disperse for 5-10 minutes at a speed of 500-1000r/min to obtain a uniform solution L1;

S120. Add the water-based epoxy resin A to the above-mentioned homogeneous solution L1, and disperse for 15-20 minutes at a speed of 500-1000 r/min to obtain a mixture L2;

S130. Add the water-based epoxy resin B to the mixed solution L2, and disperse for 15-20 minutes at a speed of 500-1000 r/min to obtain a mixture L3;

S140. Put pigments and fillers in the mixed solution L3, and disperse it to a fineness of 85um or less, and a rotation speed of 800-1000r/min to obtain a mixture L4;

S150. Put a thixotropic agent into the mixture L4, and disperse for 15-20 minutes at a speed of 500-1000 r/min to obtain a mixture L5;

S160. After cooling, filter and pack to obtain component A;

Preparation method of component B:

S210. Put deionized water into the pull cylinder, slowly add the water-based curing agent while stirring, disperse for 10-15min, and rotate at 500-800r/min;

S220, after dispersing, filtering and packaging are performed to obtain component B.

In the water-based epoxy anticorrosive coating provided by the present invention, the water-based epoxy resin A has a hydrophilic group in the resin molecular chain, which can self-emulsify in contact with water, and the water-based epoxy resin B has one end hydrophilic and one end containing a highly active epoxy It has good compatibility with resin A and has self-emulsification function. Its viscosity is low, and its activity is high. It is easy to react with the curing agent; and after the water-based epoxy resin A and the water-based epoxy resin B are mixed, the water-based epoxy resin B ring The oxygen group preferentially reacts with the curing agent amine group. The progress of this reaction can promote the reaction between the curing agent and A resin, and the final system will form a film on its own without the application of cosolvents, which greatly reduces the VOC emission.

The principle of the existing cosolvent in the emulsion system is that in the process of water volatilization, the concentration of the solvent inside and outside the emulsion particles changes, and more solvent enters the emulsion particles to have a swelling effect. The resin contacts the curing agent and solidifies to form a film. Finally, the cosolvent Slowly volatilize into the environment. The present invention utilizes single-end hydrophilic low-viscosity and high-activity water-based epoxy resin B, which is easy to contact and react with the curing agent. The molecular weight of the reaction resin increases, and the self-emulsified emulsion particles swell, which drives the contact between the water-based epoxy resin A and the curing agent. The final film is formed and cured without any solvent volatilization.

Self-emulsifying resins have the advantage of high-speed dispersion or grinding with pigments and fillers. Emulsion resins are oil-in-water. If they are ground or high-speed dispersion with pigments and fillers for a long time, they will easily break the emulsion, and the coating system will lose its application value. Or, if the high-speed dispersion time is short, the fineness of the pigments and fillers will not meet the requirements, and the performance of the coating will decrease and the application value will be lost. The self-emulsifying resin has a hydrophilic group in the molecular chain, which is a chemical bonding method, so it will not affect its structure if it is ground with pigments and fillers and high-speed dispersion. In addition, the water-based epoxy resin B is also an epoxy resin. The water-based epoxy resin A has good compatibility and hydrophilic groups, which is more conducive to improving the dispersion effect of the water-based epoxy resin A and pigments and fillers. It solves the process of separate pre-high-speed dispersion or grinding of pigments and fillers, saving production costs.

The water-based epoxy anticorrosive coating provided by the present invention does not require additional pre-grinding of pigments and fillers to prepare the slurry process. Through the above-mentioned inventive concept, the water-based epoxy resin A and the water-based epoxy resin B are combined without adding additional film-forming additives. The VOC content is low; it has the characteristics of high storage stability, strong adhesion, high mechanical strength, excellent anti-corrosion performance, good construction process performance, energy saving, environmental protection, and low cost.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The present invention provides the following examples (parts per unit mass):

Table 1

In the above embodiment 1:

Waterborne epoxy resin B uses diglycidyl isophthalate;

The dispersing agent is 650U; the defoaming agent is 285W; the wetting agent is 470U; the thixotropic agent is water-based bentonite and the anti-flash agent is general F5100;

The water-based curing agent adopts modified polyamide;

In Example 2:

Waterborne epoxy resin B uses diglycidyl hexahydrophthalate;

The dispersant adopts 690W defoamer, 280W wetting agent, 360S thixotropic agent, and water-based silicate;

The anti-flash agent adopts general F5100

The water-based curing agent adopts modified alicyclic amine;

In Example 3:

Waterborne epoxy resin B uses diglycidyl adipate;

The dispersant adopts 520S;

Use 290W as defoamer and 385S as wetting agent;

The thixotropic agent adopts organically modified hectorite clay;

The anti-flash agent is generally F5100;

The water-based curing agent adopts modified polyamidoamine;

In Comparative Example 1 and Comparative Example 2, except for the water-based epoxy resins A and B, the other specific raw materials and ratios used are the same as those in Example 3.

Among them, in Examples 1, 2, and 3, component A and component B were used according to 6.5:1, 7:1 and 7.3:1, and tested according to the indicators shown in the following table:

Table 2

The test results of Examples 1, 2, and 3 are shown in the following table:

table 3

It can be seen from the comparison of the above table that if waterborne epoxy resin A or waterborne epoxy resin B is used alone, compared with Example 3, its adhesion, impact resistance, water resistance, salt spray test, acid resistance and alkali resistance All aspects are reduced. This is because resin A alone has slow reaction with curing agent, incomplete curing of the coating, and poor acid and alkali resistance; in addition, resin B alone reacts quickly with curing agent and wets the substrate. The spreading performance is poor, and the mechanical properties and resistance are reduced, which cannot meet the requirements.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. Scope.

Claims

A waterborne epoxy anticorrosive coating, which is characterized in that it includes component A and component B, wherein component A includes:

Water-based epoxy resin A, water-based epoxy resin B, dispersant, defoamer, wetting agent, thixotropic agent, anti-flash agent, pigment, filler, deionized water;

Wherein, the water-based epoxy resin A is a self-emulsifying water-based epoxy resin;

The water-based epoxy resin B is a glycidyl ester epoxy resin;

The second component includes: curing agent and deionized water;

The curing agent is an amine curing agent.
The waterborne epoxy anticorrosive coating according to claim 1, wherein the mass parts of each raw material in the first component are:
The waterborne epoxy anticorrosive coating according to claim 1, wherein the mass parts of the raw materials in the second component are: 60 parts of curing agent and 40 parts of deionized water.
The waterborne epoxy anticorrosive coating according to claim 1, wherein the solid content of the waterborne epoxy resin A is 100%, which is selected from Foshan Tongde Chemical 3EE107B self-emulsifying waterborne epoxy resin.
The water-based epoxy anticorrosive coating according to claim 1, wherein the solid content of the water-based epoxy resin B is 100%, selected from the group consisting of hexahydrophthalic acid diglycidyl ester and isophthalic acid diglycidyl One or two or more of glycerides and diglycidyl adipate.
The water-based epoxy anticorrosive coating of claim 1, wherein the thixotropic agent is at least one of water-based bentonite, water-based silicate, and organically modified hectorite clay.
The waterborne epoxy anticorrosive coating according to claim 1, wherein the pigment and filler are mica dust, composite iron-titanium powder, mica powder, iron oxide red, talc, zinc phosphate, aluminum tripolyphosphate, long At least three combinations of stone powder and titanium dioxide.
The waterborne epoxy anticorrosive coating of claim 1, wherein the defoamer is selected from at least one of 180W, 182W, 280W, 282W, 285W, 290W, and 291W.
The waterborne epoxy anticorrosive coating according to claim 1, wherein the dispersant is at least one of modified polyurethane, high molecular polymer, unsaturated carboxylic acid, and high molecular block polymer.
The waterborne epoxy anticorrosive coating according to claim 9, wherein the dispersant is selected from at least one of Eucalyptus 520S, 560S, 650U, 685U, 690W, 765S.
The waterborne epoxy anticorrosive coating according to claim 1, wherein the wetting agent is at least one of organically modified polysiloxane, fluorocarbon modified silicone, functional acrylate, and fluorocarbon polymer kind.
The waterborne epoxy anticorrosive coating of claim 1, wherein the wetting agent is selected from at least one of Eucalyptus 430S, 470U, 375S, 360S, 361S, and 385S.
A preparation method of the waterborne epoxy anticorrosive coating according to any one of claims 1-10, comprising:

Preparation method of component A:

S110. Add deionized water to the pull cylinder, add defoamer, dispersant, and wetting agent, respectively, and disperse for 5-10 minutes at a speed of 500-1000r/min to obtain a uniform solution L1;

S120. Add the water-based epoxy resin A to the above-mentioned homogeneous solution L1, and disperse for 15-20 minutes at a speed of 500-1000 r/min to obtain a mixture L2;

S130. Add the water-based epoxy resin B to the mixed solution L2, and disperse for 15-20 minutes at a speed of 500-1000 r/min to obtain a mixture L3;

S140. Put pigments and fillers in the mixed solution L3, and disperse it to a fineness of 85um or less, and a rotation speed of 800-1000r/min to obtain a mixture L4;

S150. Put a thixotropic agent into the mixture L4, disperse for 15-20 min, rotate speed 500-1000r/min, and obtain mixture L5;

S160. After cooling, filter and pack to obtain component A;

Preparation method of component B:

S210. Put deionized water into the pull cylinder, slowly add the water-based curing agent while stirring, disperse for 10-15min, and rotate at 500-800r/min;

S220, after dispersing, filtering and packaging are performed to obtain component B.