CN117247719A - Water-based protective coating composition and preparation method and application thereof - Google Patents

Water-based protective coating composition and preparation method and application thereof Download PDF

Info

Publication number
CN117247719A
CN117247719A CN202210644404.9A CN202210644404A CN117247719A CN 117247719 A CN117247719 A CN 117247719A CN 202210644404 A CN202210644404 A CN 202210644404A CN 117247719 A CN117247719 A CN 117247719A
Authority
CN
China
Prior art keywords
parts
protective coating
coating composition
water
aqueous
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210644404.9A
Other languages
Chinese (zh)
Inventor
马永强
王士志
李旺
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tianjin Binhai New Area Libang Paint Co ltd
Guangzhou Nippon Paint Co Ltd
Original Assignee
Tianjin Binhai New Area Libang Paint Co ltd
Guangzhou Nippon Paint Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tianjin Binhai New Area Libang Paint Co ltd, Guangzhou Nippon Paint Co Ltd filed Critical Tianjin Binhai New Area Libang Paint Co ltd
Priority to CN202210644404.9A priority Critical patent/CN117247719A/en
Publication of CN117247719A publication Critical patent/CN117247719A/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/08—Anti-corrosive paints
    • C09D5/082—Anti-corrosive paints characterised by the anti-corrosive pigment
    • C09D5/084—Inorganic compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/42—Gloss-reducing agents
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/61—Additives non-macromolecular inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/65—Additives macromolecular
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/30—Sulfur-, selenium- or tellurium-containing compounds
    • C08K2003/3045—Sulfates
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/32—Phosphorus-containing compounds
    • C08K2003/321—Phosphates
    • C08K2003/328—Phosphates of heavy metals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
    • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Paints Or Removers (AREA)

Abstract

The invention relates to an aqueous protective coating composition suitable for automobile metal parts, which comprises the following components in parts by weight: 56.1 to 61.3 parts of water-based epoxy resin, 1.1 to 1.5 parts of coloring pigment, 6.3 to 7.3 parts of antirust pigment, 8.6 to 9.6 parts of filler, 1.0 to 3.0 parts of extinction powder, 0.5 to 1.0 part of phosphate polymer, 0.6 to 1.0 part of double-component flash rust inhibitor, 2.2 to 3.6 parts of auxiliary agent and 15.0 to 18.0 parts of solvent, wherein the total weight of the components is 100 parts. The water-based protective coating composition can be used for coating metal parts such as automobile brake discs, steering knuckles and transmission shafts, and has good salt spray resistance, volatile oil resistance, water resistance and over-high temperature adhesion. The invention also relates to a preparation method and application of the water-based protective coating composition, and a coating based on the water-based protective coating composition.

Description

Water-based protective coating composition and preparation method and application thereof
Technical Field
The invention relates to the technical field of coatings, in particular to a water-based protective coating composition, and more particularly relates to a water-based protective coating composition suitable for coating automobile metal parts, and a preparation method and application of the coating composition.
Background
The aqueous protective coating composition takes aqueous single-component self-drying epoxy resin as a main film forming substance. Because the epoxy resin has strong cohesive force, the material structure is compact, and the epoxy resin contains epoxy groups, hydroxyl groups, ether bonds, ester bonds and other polar groups with larger activity, the epoxy resin coating has excellent adhesive force to metal and other polar substrates.
Along with the continuous improvement of environmental protection requirements, various regulations related to environmental protection are more and more strict, especially, the emission of Volatile Organic Compounds (VOCs), the content of harmful solvents and various heavy metals are more and more limited, and the development of environment-friendly water-based protective coatings with low VOC emission has become a trend of development of the coating industry.
In the prior art, most of water-based protective coating compositions have the problem that the water-based protective coating compositions cannot be dried or baked at low temperature and quickly cured to form films, are not favorable for being used in the coating of automobile parts, and the existing water-based protective coatings are generally poor in salt spray resistance, volatile oil resistance, water resistance and over-high temperature adhesion, so that the requirements of industry development are gradually not met.
In view of the above, the present invention aims to provide an aqueous protective coating composition to solve the problems faced in the technical field of the existing coating.
Disclosure of Invention
Based on the facts, the invention aims to provide an aqueous protective coating composition which can be used for coating metal parts such as automobile brake discs, steering knuckles and transmission shafts and has good salt spray resistance, volatile oil resistance, water resistance and over-high temperature adhesion.
The first aspect of the invention provides an aqueous protective coating composition, which comprises the following components in parts by weight:
the total weight of the above components is 100 parts.
Water-based epoxy resin
In the invention, the aqueous epoxy resin comprises two different aqueous epoxy resins A and B, wherein the weight ratio of the aqueous epoxy resin A to the aqueous epoxy resin B is 2:1-2.3:1.
Preferably, the nonvolatile content of the aqueous epoxy resin A and the aqueous epoxy resin B is 35.0-41.0%, the viscosity is 500-10000 Pa.s, and the pH is 8-11.
Specifically, the aqueous epoxy resin A is an aqueous epoxy resin with the model of EPICLON H-502-42W (purchased from Dielsen company), the nonvolatile content of the aqueous epoxy resin A is 37.0-41.0%, the viscosity of the aqueous epoxy resin A is 500-10000 Pa.s, and the pH of the aqueous epoxy resin A is 8-11; the water-based epoxy resin B is water-based epoxy resin with model MODEPHICS 304C (purchased from the Qichuan chemical company), the nonvolatile content of the water-based epoxy resin B is 35.0-38.0%, the viscosity is 1500Pa.s, and the pH is 9-11;
coloring pigment
In some embodiments of the invention, the colored pigment is carbon black.
Specifically, the colored pigment is a carbon black having a type of MITSUBISHI CARBON BLACK MA-100 (available from Mitsubishi chemical).
Rust-proof pigment
In some embodiments of the invention, the rust inhibitive pigment is zinc phosphate. The rust-proof pigment used in the invention can further improve the salt spray resistance of the coating, and is mainly characterized in that the corrosion of X-shaped tangent parts of metal parts in a salt spray resistance test is reduced, the coating structure is filled with fine particles, the compactness of the coating is improved, the shielding effect is achieved, and the permeability of the coating is reduced, so that the rust-proof effect is achieved. Experiments show that zinc phosphate as an anti-rust pigment has better salt spray resistance than aluminum tripolyphosphate as an anti-rust pigment.
Preferably, the zinc content of the zinc phosphate is 45.0-49.0%, the phosphate radical content is 44.0-48.0%, and the oil absorption is 15-25.
Specifically, the rust inhibitive pigment is zinc phosphate of model 409 (available from Jiangsu Shen Longxin Co., ltd.) with zinc content of 45.0-49.0%, phosphate radical content of 44.0-48.0% and oil absorption of 15-25.
Packing material
In some embodiments of the invention, the filler is barium sulfate.
Preferably, the oil absorption of the barium sulfate is 15-25, and the pH is 6.5-9.0.
Specifically, the filler is barium sulfate sold in Hebei octyl chemical industry, the BaSO4 content is more than or equal to 98%, the oil absorption is 15-25, and the pH is 6.5-9.0.
Extinction powder
In some embodiments of the invention, the matting powder is silica. The purpose of using the matting powder in the invention is to increase the thixotropic property of the coating so as to improve the lacquering property of the coating at the chamfering position of the edge of the metal workpiece and increase the film thickness of the paint film at the position, thereby achieving the purpose of improving the corrosion resistance of the position.
Preferably, the specific surface area of the silica is 300m 2 And/g, the average particle diameter is 1.7-2.1 μm.
Specifically, the matting agent is silica of type AZ 201 or AZ 204 (available from eastern co.).
Phosphate polymers
In some embodiments of the invention, the phosphate polymer is an alkylaryl phosphate. The phosphate polymer used in the invention can improve the adhesive force and salt spray resistance of the paint film on the metal substrate.
Specifically, the phosphate polymer is an alkylaryl phosphate ester having a non-volatile content of 59 to 66% and having the type Lubrizol 2062 (available from Lubrizol Corp.).
Double-component flash rust inhibitor
In some embodiments of the invention, the two-component flash rust inhibitor comprises a component a and a component B in a mass ratio of 1:1. The invention uses the double-component flash rust inhibitor to solve the problems of foaming, rust dropping, rust penetration and the like in salt mist overdose resistance, and the mechanism is that the double-component flash rust inhibitor plays a role in slow-release protection on a base material.
Specifically, the component A is selected from CHE L6NF or CHE L8NF (purchased from Oroqi chemical engineering Co., ltd.) and is a mixed solution of inorganic acid and amine; the component B is selected from CHE L6AF or CHE L8AF, and is one or two mixed solutions of sodium salt and potassium salt.
Auxiliary agent
In some embodiments of the invention, the auxiliary agent is selected from one or more of a pH adjuster, a leveling agent, an antifoaming agent, a substrate wetting agent, or a wetting dispersant.
In a preferred embodiment of the present invention, the auxiliary agent comprises the following components in parts by weight:
0.10 to 0.30 portion of pH regulator;
the leveling agent is 0.20 to 0.30 part, preferably 0.20 to 0.25 part, more preferably 0.25 to 0.30 part.
0.10 to 0.30 parts, preferably 0.10 to 0.20 parts, more preferably 0.20 to 0.30 parts of defoamer;
0.20 to 0.30 parts, preferably 0.20 to 0.25 parts, more preferably 0.25 to 0.30 parts of a substrate wetting agent;
1.60 to 2.40 parts, preferably 1.60 to 2.00 parts, more preferably 2.00 to 2.40 parts of wetting dispersant;
the total weight of the components is 2.2-3.6 parts.
Specifically, the pH adjuster is dimethylethanolamine (available from basf corporation); the leveling agent is BYK 381 (purchased from BYK company); the defoamer was BYK 011 (available from BYK corporation); the substrate wetting agent is TEGO 4100 (available from TEGO corporation); the wetting dispersant is BYK 190 (available from BYK corporation).
Solvent(s)
In some embodiments of the invention, the solvent is selected from at least one of an ether solvent, an alcohol solvent, deionized water.
Preferably, the solvent is selected from two or more of ether solvents, alcohol solvents, deionized water. The volatilization rate of the ether solvent and the alcohol solvent is lower than that of deionized water, and the ether solvent and the alcohol solvent have good miscibility with the deionized water, so that the volatilization rate of the whole coating system can be regulated, and the abnormal conditions such as foaming/prickly heat and the like in the coating and baking processes are avoided.
More preferably, the solvent comprises 4.0 to 6.0 parts of ether solvent and 11.0 to 12.0 parts of deionized water by weight, wherein the ether solvent is selected from one or a combination of propylene glycol methyl ether and dipropylene glycol butyl ether, and the total weight of the components is 15.0 to 18.0 parts.
In a second aspect, the present invention provides a method of preparing an aqueous protective coating composition according to the first aspect of the invention, comprising the steps of:
(1) Adding wetting dispersant, defoamer and partial solvent into a container A, stirring under the condition of 300-500 r/min, adding coloring pigment, antirust pigment, filler and extinction powder under the stirring state, stirring for about 20-30 min until the dispersion is uniform and no caking is caused, and stopping stirring;
(2) Sanding the mixed material in the container A until the fineness is less than or equal to 10 mu m;
(3) Adding the residual solvent into a container B, stirring under the condition of 200-300 r/min, adding the aqueous epoxy resin A and the aqueous epoxy resin B in a stirring state, stirring for 5-10 min, sequentially adding the mixture, the phosphate polymer, the two-component flash rust inhibitor, the substrate wetting agent, the leveling agent and the like into the sanded container A, and continuing stirring for 10-15 min;
(4) And (3) regulating the pH value of the mixed material obtained in the step (3) to 8.5-9.0 by using a pH regulator, thus obtaining the water-based protective coating composition.
In a third aspect, the present invention provides the use of the aqueous protective coating composition, in particular for the coating of automotive metal parts.
In a fourth aspect, the present invention provides an aqueous protective coating comprising the aqueous protective coating composition of the first aspect of the present invention.
The beneficial effects of the invention are as follows:
the water-based protective coating composition provided by the invention is prepared by compounding two different water-based self-drying epoxy resins in a certain proportion to be used as main resin, and adding coloring pigment, antirust pigment, extinction powder, phosphate polymer, two-component flash rust inhibitor, other auxiliary agents and the like, so that the prepared water-based protective coating composition can realize self-drying or low-temperature baking and fast curing to form a film, has good salt spray resistance, volatile oil resistance, water resistance and over-high-temperature adhesion, is sprayed on metal parts such as an automobile brake disc, a knuckle and a transmission shaft, the hardness of a paint film pencil after curing can reach F, the neutral salt spray can reach 300h, single-side corrosion is less than 3mm, water resistance is realized for 240h at 40 ℃ without foaming and spalling, and the adhesive force is 0 level after the over-high temperature is carried out for 350 ℃ or 2 min.
Detailed Description
In order that the invention may be more clearly understood, a further description of the invention will be provided below with reference to specific examples. It is to be understood that the following detailed description is intended to be illustrative, and not restrictive, and that this invention is not to be limited to the specific embodiments shown.
The water-based protective coating composition provided by the invention takes the water-based self-drying epoxy resin as main resin, and is matched with a proper amount of filler and matting powder, so that the water-based protective coating composition is self-dried or baked at low temperature and rapidly cured into a film.
Specifically, the purpose of using the matting agent in the invention is to increase the thixotropic property of the coating so as to improve the lacquering property of the coating at the chamfering position of the edge of the metal workpiece and increase the film thickness of the paint film at the position, thereby achieving the purpose of improving the corrosion resistance of the position.
Furthermore, the invention also adds proper amount of antirust pigment, phosphate polymer, double-component flash rust inhibitor and auxiliary agent, so that the water-based protective coating composition has good salt fog resistance, volatile oil resistance, water resistance and high-temperature adhesion resistance, and ensures that other performances are unchanged.
On one hand, the antirust pigment used in the invention can further improve the salt spray resistance of the coating film, and is mainly characterized in that the corrosion of X-shaped tangent parts of metal parts in a salt spray resistance test is reduced, the coating film structure is filled by fine particles, the compactness of the coating film is improved, the shielding effect is achieved, and the permeability of the coating film is reduced, so that the antirust effect is achieved. Preferably, zinc phosphate as the rust inhibitive pigment has better salt spray resistance than aluminum tripolyphosphate as the rust inhibitive pigment.
On the other hand, the double-component flash rust inhibitor can solve the problems of foaming, rust dropping, rust penetration and the like in salt spray overdose resistance, and the mechanism is that the double-component flash rust inhibitor plays a role in slow-release protection on a base material.
In yet another aspect, the phosphate polymer is used in an amount that enhances the adhesion and salt spray resistance of the paint film to the metal substrate.
The water-based protective coating composition is suitable for a simple air spraying mode, is simple in construction, easy to operate, high in surface drying rate and suitable for coating automobile metal parts such as brake discs, transmission shafts and knuckles.
The technical scheme of the invention is described below with reference to some more specific embodiments:
description of related raw materials and manufacturer
The aqueous epoxy resin A is EPICLON H-502-42W, and is purchased from Dielsen company;
the aqueous epoxy resin B is MODEPHICS 304C, which is purchased from the Sichuan chemical company;
the coloring pigment is MITSUBISHI CARBON BLACK MA-100 carbon black, purchased from Mitsubishi chemical;
the rust-inhibiting pigment is 409 zinc phosphate, purchased from Jiangsu Shen Longxin company;
the filler is barium sulfate, and is purchased from Hebei octyl chemical industry;
the matting powder is silicon dioxide AZ 201 or AZ 204, which is purchased from Tosoh corporation;
phosphate polymer Lubrizol 2062, available from Lubrizol corporation;
two-component flash rust inhibitors CHE L6NF and CHE L6AF, or CHE L8NF and CHE L8AF, purchased from aloqi chemical engineering, inc;
the pH adjuster dimethylethanolamine, available from basf company;
wetting dispersant BYK 190, available from BYK corporation;
the defoamer is BYK 011, purchased from BYK company;
the substrate wetting agent was TEGO 4100, available from TEGO corporation;
the leveling agent is BYK 381, which is purchased from BYK company;
example 1: aqueous protective coating composition 1
An aqueous protective coating composition 1 was prepared according to the formulation shown in table 1 below:
table 1 weight parts of raw materials of example 1
The preparation process of the water-based protective coating composition 1 comprises the following steps:
(1) 2.2 parts of wetting dispersant, 0.2 part of defoamer, 8 parts of deionized water and 3.0 parts of propylene glycol methyl ether are put into a container A, stirred under the condition of 400r/min, 1.3 parts of carbon black, 6.8 parts of zinc phosphate, 9.1 parts of barium sulfate and 2.0 parts of extinction powder are put into the container A under the stirring state, and stirring is stopped after the mixture is uniformly dispersed and does not agglomerate for about 20 to 30 minutes;
(2) Sanding the mixed material in the container A until the fineness is less than or equal to 10 mu m;
(3) 2.0 parts of dipropylene glycol butyl ether and the rest 3.7 parts of deionized water are put into a container B, stirred at the condition of 300r/min, 40.5 parts of aqueous epoxy resin EPICLON H-502-42W and 19 parts of aqueous epoxy MODEPHSIS 304C are put into the container B, stirred for 8min, and then the materials of mixed materials, 0.8 part of phosphate polymer, 0.4 parts of each two-component flash rust inhibitor CHE L6NF and CHE L6AF, 0.2 part of base material wetting agent, 0.2 part of leveling agent and the like are sequentially put into the container A after sanding, and stirring is continued for 15min;
(4) And (3) regulating the pH value of the mixed material obtained in the step (3) to 8.5-9.0 by using 0.2 part of dimethylethanolamine serving as a pH regulator, thus obtaining the water-based protective coating composition 1.
Comparative example 1: water-based protective coating composition C1
Example 1 was repeated except that the aqueous epoxy resin A of example 1 was replaced with a solid amount of a commercially available aqueous acrylic-modified epoxy resin LWEA-3250NP, etc., and the other materials were used in unchanged amounts.
The description is as follows: in this comparative example, the aqueous acrylic-modified epoxy resin LWEA-3250NP used required crosslinking and curing of the curing resin, was not self-drying, and was not within the scope of the present invention, so this example was comparative example 1 alone, and the use of such an epoxy resin resulted in a decrease in the adhesion, water resistance, volatile oil resistance, salt spray resistance, etc. of the coating due to poor adhesion of the commercially available resin itself to the metal substrate.
Comparative example 2 aqueous protective coating composition C2
Example 1 was repeated except that the aqueous epoxy resin B of example 1 was replaced with a solid amount of a commercially available aqueous acrylic-modified epoxy resin LWEA-3250NP, etc., and the other materials were used in unchanged amounts.
The description is as follows: in this comparative example, the aqueous acrylic-modified epoxy resin LWEA-3250NP used required crosslinking and curing of the curing resin, was not self-drying, and was not within the scope of the present invention, so this example was comparative example 2 only, and as in comparative example 1, the use of such an epoxy resin resulted in a decrease in the paint adhesion, water resistance, salt spray resistance, and the like, due to poor adhesion of the commercially available resin itself to the metal substrate.
Comparative example 3 aqueous protective coating composition C3
Comparative example 3 is a commercially available conventional aqueous protective coating for metal parts.
The description is as follows: in the composition of the aqueous protective coating material in this comparative example, the contents of the rust inhibitive pigment, the flash rust inhibitive agent and the like are not within the scope of the present invention, so this example is comparative example 3 only.
Comparative example 4 aqueous protective coating composition C4
Example 1 was repeated except that the amounts of the aqueous epoxy resin A and the aqueous epoxy resin B were used, and the parts by weight of the raw materials of comparative example 4 are shown in Table 2.
Table 2 comparative example 4 parts by weight of raw materials
The description is as follows: in this comparative example, the ratio of the aqueous epoxy resins A and B was 4.95:1, exceeding the upper limit of the amount range of 2.3:1, which is not within the scope of the present invention, so this example is comparative example 4 only. Too high a proportion of the aqueous epoxy resin A leads to deterioration of the water resistance of the paint film.
Comparative example 5: aqueous protective coating composition C5
Example 1 was repeated except that the amounts of the aqueous epoxy resin A and the aqueous epoxy resin B were used, and the parts by weight of the raw materials of comparative example 5 are shown in Table 3.
Table 3 comparative example 5 parts by weight of raw materials
The description is as follows: in this comparative example, the ratio of the aqueous epoxy resins A and B was 1.05:1, which is lower than the lower limit of the 2:1 dosage range, which is not within the scope of the present invention, so this example is comparative example 5 only. Too low a proportion of the aqueous epoxy resin A leads to a reduced salt spray resistance of the paint film.
Comparative example 6: aqueous protective coating composition C6
Example 1 was repeated except that the aqueous epoxy resin A and the rust inhibitive pigment were used in amounts, and the parts by weight of the raw materials of comparative example 6 are shown in Table 4.
Table 4 comparative example 6 parts by weight of raw materials
The description is as follows: in this comparative example, the amount of the rust inhibitive pigment was 5.3 parts, which is lower than the lower limit value of the amount range by 6.3 parts, which is not within the scope of the present invention, so this example is comparative example 6 only. Too little amount of rust inhibitive pigment may cause a decrease in salt spray resistance of the paint film.
Comparative example 7: aqueous protective coating composition C7
Example 1 was repeated except that the amounts of the aqueous epoxy resin B and the two-component flash rust inhibitor were used, and the parts by weight of the raw materials of comparative example 7 are shown in Table 5.
Table 5 comparative example 7 parts by weight of raw materials
The description is as follows: in this comparative example, the amount of the two-component flash rust inhibitor was 0.4 part, which is less than the lower limit value of the amount range of 0.6 part, which is not within the scope of the present invention, so this example is comparative example 7 only. Too little amount of the two-component flash rust inhibitor can lead to the reduction of salt spray resistance of a paint film.
Test example 1: performance testing of aqueous protective coating compositions
A substrate: automobile brake disc workpieces (iron castings, silane pretreatment).
The coating process comprises the following steps: spraying by an air gun, wherein the spraying viscosity is 26.0-30.0'/20 ℃ and 4 cups are coated.
Coating composition: automobile brake disc work piece + waterborne protective coating composition.
And (3) baking the brake disc workpiece coating at 80 ℃ for 30min (effective temperature of the workpiece surface), and naturally curing for 7 days at room temperature to obtain the water-based protective coating for the automobile metal parts.
Because the production process conditions of different automobile metal parts are different, some baking conditions for producing the automobile metal parts are 120 ℃ for 15min (effective temperature of the surface of a workpiece), and under the baking conditions, the natural curing of the workpiece at room temperature can be shortened to 4 days.
The detection method of the performance is shown in Table 6:
table 6 Performance test methods
The performance of the aqueous protective coating compositions of example 1 and comparative examples 1 to 7 was measured by the above method, and the results are shown in tables 7 and 8.
TABLE 7 Properties of the stoving varnish varnishes of example 1 and comparative examples 1 to 3
Table 8 Properties of the stoving varnish varnishes of comparative examples 4 to 7
The test results from tables 7 and 8 above show that:
(1) The water-based protective coating composition is sprayed under standard construction conditions, the appearance of a paint film is free from abnormality, and the performance of the paint film meets the technical index requirements.
(2) Comparative example 1 the aqueous epoxy resin a of example 1 was replaced with a solid amount of a commercially available aqueous acrylic modified epoxy resin LWEA-3250NP, etc., resulting in disqualification of adhesion, water resistance, volatile oil resistance and neutral salt spray due to poor adhesion of the commercially available resin itself to the metal substrate.
(3) Comparative example 2 the aqueous epoxy resin B of example 1 was replaced with a solid amount of a commercially available aqueous acrylic modified epoxy resin LWEA-3250NP, etc., resulting in disqualification of adhesion, water resistance and neutral salt spray for the same reasons as comparative example 1.
(4) Comparative example 3 is a commercially available aqueous protective coating, which is unacceptable for pencil hardness, neutral salt spray, and high temperature compactibility/salt spray.
(5) The ratio of the aqueous epoxy resin A to the aqueous epoxy resin B in comparative example 4 exceeds the upper limit value of the dosage range of 2.3:1, resulting in poor water resistance of the paint film and failure.
(6) The ratio of the aqueous epoxy resins A and B in comparative example 5 was lower than the lower limit of the use amount range of 2.0:1, resulting in unacceptable neutral salt spray performance.
(7) The amount of the rust inhibitive pigment in comparative example 6 was lower than the lower limit value of the amount range of 6.3 parts, resulting in X-shaped tangential line embroidery corrosion of > 3mm and unacceptable neutral salt spray performance.
(8) The dosage of the double-component flash rust inhibitor in the comparative example 7 is lower than the lower limit value of the dosage range of 0.8 part, and although the linear embroidery corrosion of the X-shaped tangent is less than 3mm, bubbles and rust appear in the area beyond the X-shaped tangent, and the neutral salt fog performance is still unqualified.
Example 2: aqueous protective coating composition 2
Example 1 was repeated except that the two-component flash rust inhibitors were CHE L8NF and CHE L8AF. The parts by weight of the raw materials of example 2 are shown in Table 9.
Table 9 example 2 parts by weight of raw materials
Example 3: aqueous protective coating composition 3
Example 1 was repeated except that the matting powder was AZ 204. The parts by weight of the raw materials of example 3 are shown in Table 10.
Table 10 example 3 parts by weight of raw materials
Example 4: aqueous protective coating composition 4
Example 1 was repeated except that the matting powder was AZ 204 and the two-component flash rust inhibitors were CHE L8NF and CHE L8AF. The parts by weight of the raw materials of example 4 are shown in Table 11.
Table 11 parts by weight of the raw materials of example 4
Example 5: aqueous protective coating composition 5
Example 1 was repeated except that the weight part ratio of the aqueous epoxy resins A and B was 2.3:1.
Example 6: aqueous protective coating composition 6
Example 1 was repeated except that the weight part ratio of the aqueous epoxy resins A and B was 2.0:1.
Example 7: aqueous protective coating composition 7
Example 1 was repeated with the difference that the amounts of the aqueous epoxy resin a and the rust inhibitive pigment zinc phosphate were used. The parts by weight of the raw materials of example 7 are shown in Table 12.
Table 12 parts by weight of the raw materials of example 1
Example 8: aqueous protective coating composition 8
Example 1 was repeated with the difference that the amounts of the aqueous epoxy resin B and the rust inhibitive pigment zinc phosphate were used. The parts by weight of the raw materials of example 8 are shown in Table 13.
Table 13 parts by weight of the raw materials of example 1
Example 9: aqueous protective coating composition 9
Example 1 was repeated with the difference that the amounts of aqueous epoxy resin a, aqueous epoxy resin B, rust inhibitive pigment zinc phosphate and filler barium sulfate were used. The parts by weight of the raw materials of example 9 are shown in Table 14.
Table 14 parts by weight of the raw materials of example 1
Example 10: aqueous protective coating composition 10
Example 1 was repeated except for the amounts of aqueous epoxy resin A, aqueous epoxy resin B, rust inhibitive pigment zinc phosphate, filler barium sulfate, matting powder, phosphate polymer, two-component flash rust inhibitor and propylene glycol methyl ether. The parts by weight of the raw materials of example 10 are shown in Table 15.
Table 15 parts by weight of the raw materials of example 1
The main coating properties of the aqueous protective coating compositions of examples 2 to 10 were tested in the manner of test example 1 described above, and the test results are shown in Table 16, which shows that the test results are similar to those of example 1, and that the respective components and the compounding amounts of the aqueous protective coating compositions defined in the scheme of the present invention can achieve the object of the present invention.
TABLE 16 principal parameters of aqueous protective coatings of examples 2-10
Examples Adhesion force Hardness of pencil Water resistance Medium-sized salt fog
Example 2 100/100 free from falling off F No abnormality Linear rust 1mm
Example 3 100/100 free from falling off F No abnormality Linear rust 2mm
Example 4 100/100 free from falling off F No abnormality Linear rust 1mm
Example 5 100/100 free from falling off F No abnormality Linear rust 1mm
Example 6 100/100 free from falling off F No abnormality Linear rust 1mm
Example 7 100/100 free from falling off F No abnormality Linear rust 1mm
Example 8 100/100 free from falling off F No abnormality Linear rust 2mm
Example 9 100/100 free from falling off F No abnormality Linear rust 2mm
Example 10 100/100 free from falling off H No abnormality Linear rust less than 1mm
Comparative example 8: aqueous protective coating composition C8
The raw material formulation of comparative example 8 was the same as in example 1 except that during the preparation of the aqueous protective coating composition C8, a part of the aqueous epoxy resin, the matting powder, the pigment and the filler were ground and dispersed together, and the specific procedure was as follows.
(1) 2.2 parts of wetting dispersant, 0.2 part of defoamer, 8 parts of deionized water and 3.0 parts of propylene glycol methyl ether are put into a container A, stirred under the condition of 400r/min, 20 parts of waterborne epoxy resin EPICLON H-502-42W, 1.3 parts of carbon black, 6.8 parts of zinc phosphate, 9.1 parts of barium sulfate and 2.0 parts of extinction powder are put into the container A under the stirring state, and stirring is stopped after the mixture is uniformly dispersed and does not have caking for about 20 to 30 minutes;
(2) Grinding the mixed material in the container A until the fineness is less than or equal to 10 mu m;
(3) 2.0 parts of dipropylene glycol butyl ether and the rest 3.7 parts of deionized water are put into a container B, stirred under the condition of 300r/min, and then sequentially put into the mixture after sanding in the container A, 20.5 parts of waterborne epoxy resin EPICLON H-502-42W, 19.0 parts of waterborne epoxy resin MODEPHS 304C, 0.8 parts of phosphate polymer, 0.4 parts of each two-component flash rust inhibitor CHE L6NF and CHE L6AF, 0.2 part of substrate wetting agent, 0.2 part of leveling agent and other materials, and continuously stirred for 15min;
(4) And (3) regulating the pH value of the mixed material obtained in the step (3) to 8.5-9.0 by using 0.2 part of dimethylethanolamine serving as a pH regulator, thus obtaining the water-based protective coating composition.
As described above, in this comparative example, the process of grinding and dispersing a part of the aqueous epoxy resin, the matting powder, and the pigment and filler together was adopted, which is not within the scope of the present invention, so this example is comparative example 8 only. It should be noted that, in this comparative example, neither of the aqueous epoxy resins a and B can participate in grinding, and no matter how much of the aqueous epoxy resin in the step (1) causes flocculation of the aqueous protective coating, which indicates that the steps of the preparation method of the present invention can effectively prevent agglomeration.
Comparative example 9: aqueous protective coating composition C9
The raw material formulation of comparative example 9 was the same as in example 1 except that the two-component flash rust inhibitor was mixed in advance and then put into vessel B together.
It should be noted that: in this comparative example, the preparation process adopted the operation method of mixing the two-component flash rust inhibitor in advance and then putting it into the container B together, instead of the sequential addition described in the present invention, so that it is not within the scope of the present invention, so this example is comparative example 9 only. The neutral salt fog resistance of the water-based protective coating prepared by the method is poor.
It should be apparent that the foregoing examples of the present invention are merely illustrative of the present invention and not limiting of the embodiments of the present invention, and that various other changes and modifications can be made by one skilled in the art based on the above description, and it is not intended to be exhaustive of all of the embodiments, and all obvious changes and modifications that come within the spirit of the invention are desired to be protected.

Claims (10)

1. An aqueous protective coating composition comprises the following components in parts by weight:
the total weight of the components is 100 parts; the water-based epoxy resin is characterized by comprising two different water-based epoxy resins A and B, wherein the weight ratio of the water-based epoxy resin A to the water-based epoxy resin B is 2:1-2.3:1.
2. The aqueous protective coating composition of claim 1, wherein the aqueous epoxy resin a and the aqueous epoxy resin B each have a nonvolatile content of 35.0 to 41.0%, a viscosity of 500 to 10000pa.s, and a ph of 8 to 11.
3. The aqueous protective coating composition of claim 1, wherein the colored pigment is carbon black, the rust inhibitive pigment is zinc phosphate, the filler is barium sulfate, and the matting agent is silica; preferably, the zinc phosphate has a zinc content of 45.0-49.0%, a phosphate radical content of 44.0-48.0%, an oil absorption of 15-25, a barium sulfate oil absorption of 15-25, a pH of 6.5-9.0, and a specific surface area of 300m 2 And/g, the average particle diameter is 1.7-2.1 μm.
4. The aqueous protective coating composition of claim 1, wherein the phosphate polymer is an alkylaryl phosphate.
5. The aqueous protective coating composition of claim 1, wherein the two-component flash rust inhibitor comprises a component A and a component B, wherein the component A is a mixed solution of inorganic acid and amine, the component B is one or two of sodium salt and potassium salt, and the weight ratio of the component A to the component B is 1:1.
6. The aqueous protective coating composition of claim 1, wherein the auxiliary agent is selected from one or more of a pH adjuster, a leveling agent, an antifoaming agent, a substrate wetting agent, or a wetting dispersant;
preferably, the auxiliary agent comprises the following components in parts by weight:
0.10 to 0.30 portion of pH regulator;
0.20 to 0.30 part, preferably 0.20 to 0.25 part, more preferably 0.25 to 0.30 part of leveling agent;
0.10 to 0.30 parts, preferably 0.10 to 0.20 parts, more preferably 0.20 to 0.30 parts of defoamer;
0.20 to 0.30 parts, preferably 0.20 to 0.25 parts, more preferably 0.25 to 0.30 parts of a substrate wetting agent;
1.60 to 2.40 parts, preferably 1.60 to 2.00 parts, more preferably 2.00 to 2.40 parts of wetting dispersant;
the total weight of the components is 2.2-3.6 parts.
7. The aqueous protective coating composition of claim 1, wherein the solvent is selected from one or more of an ether solvent, an alcohol solvent, or deionized water; preferably, the solvent is selected from two or more of ether solvents, alcohol solvents or deionized water; more preferably, the solvent comprises 4.0 to 6.0 parts of ether solvent and 11.0 to 12.0 parts of deionized water by weight, wherein the ether solvent is selected from one or a combination of propylene glycol methyl ether and dipropylene glycol butyl ether, and the total weight of the components is 15.0 to 18.0 parts.
8. A process for preparing an aqueous protective coating composition according to any one of claims 1 to 7, comprising the steps of:
(1) Adding part of auxiliary agent and part of solvent into a container A, stirring under the condition of 300-500 r/min, adding coloring pigment, antirust pigment, filler and extinction powder under the stirring state, stirring for about 20-30 min until the mixture is uniformly dispersed and does not agglomerate, and stopping stirring;
(2) Sanding the mixed material in the container A until the fineness is less than or equal to 10 mu m;
(3) Adding the residual solvent into a container B, stirring at 200-300 r/min, adding the aqueous epoxy resin, stirring for 5-10 min, sequentially adding the materials such as the mixture, the phosphate polymer, the two-component flash rust inhibitor, the residual auxiliary agent and the like into the sanded container A, and continuously stirring for 10-15 min;
(4) And (3) regulating the pH value of the mixed material obtained in the step (3) to 8.5-9.0, thus obtaining the water-based protective coating composition.
9. Use of the aqueous protective coating composition according to any one of claims 1 to 7, wherein the aqueous protective coating composition is suitable for coating automotive metal parts such as brake discs, drive shafts and knuckles.
10. An aqueous protective coating comprising the aqueous protective coating composition of any one of claims 1 to 7.
CN202210644404.9A 2022-06-09 2022-06-09 Water-based protective coating composition and preparation method and application thereof Pending CN117247719A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210644404.9A CN117247719A (en) 2022-06-09 2022-06-09 Water-based protective coating composition and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210644404.9A CN117247719A (en) 2022-06-09 2022-06-09 Water-based protective coating composition and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN117247719A true CN117247719A (en) 2023-12-19

Family

ID=89128126

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210644404.9A Pending CN117247719A (en) 2022-06-09 2022-06-09 Water-based protective coating composition and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN117247719A (en)

Similar Documents

Publication Publication Date Title
KR100474009B1 (en) Water-reducible coating composition to provide corrosion protection
CN103788787A (en) Single-component water-based natural drying finishing coat for construction crane and preparation method thereof
CN109880484B (en) Water-based epoxy thick paste anticorrosive paint and preparation method and application thereof
CN114196290B (en) Industrial water-based paint coating and application method thereof
CN101429402A (en) Watersoluble metal self-drying antirusting paint
CN105524505A (en) Double-ingredient chrome-free water-based metal anticorrosive paint and preparation method thereof
CN106566363B (en) A kind of disc type electrostatic spraying technique suitable for water-based anticorrosive paint used for vehicle transmission shaft
KR100880461B1 (en) Water-soluble bake zinc-paint composition with improved corrosion resistance and a method of preparation thereof
CN109294396A (en) Water-based epoxy zinc-rich primer
CN112724790B (en) Polysulfide compound modified epoxy coating and corrosion prevention process for steel structure of coastal power plant
WO2021261071A1 (en) Water-based anticorrosive coating composition
CN110819195B (en) Water-based high-build paint for railway freight car and preparation method thereof
CN111592812A (en) Water-based antirust primer and preparation method thereof
CN117247719A (en) Water-based protective coating composition and preparation method and application thereof
CN108148484B (en) Water-based epoxy antirust coating for urban rails and motor cars and preparation method thereof
CN113563750B (en) Bi-component water-based anticorrosive paint and preparation method and application thereof
CN115216191A (en) Water-based hub intermediate paint and preparation method thereof
CN113416467A (en) Epoxy ester antirust water paint and preparation method thereof
KR102298842B1 (en) Coating method using water-based coating material with excellent compatability with solvelt-based coating film and eco-friendly heavy duty coating film manufactured therefrom
KR101292354B1 (en) Epoxy semi-matt powder coatings for engine block, manufacturing method thereof and coating method
CN104789104B (en) Hydroxyl group-containing polyurethane acrylate copolymer aqueous industrial paint with high mechanical performances
CN114621648A (en) Water-based single-component anticorrosive primer and preparation method thereof
JP6749737B2 (en) Anticorrosion water-based coating composition
JP4290173B2 (en) Water-based paint composition
CN108948963A (en) A kind of preparation method of water-base epoxy ester primer for rusted steel

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication