An amine emulsion, its preparation method and application

Abstract

This invention relates to the field of coatings and adhesives, specifically to an amine emulsion, its preparation method, and its application. The invention uses an amine prepolymer with a low active hydrogen equivalent as an emulsifier to emulsify another epoxy-modified amine prepolymer. The amine emulsion prepared by this invention exhibits good compatibility with waterborne epoxy resins and good storage stability. The emulsifier has fewer hydrophilic chain ends, resulting in a film with excellent anti-sagging properties and comprehensive application performance when cured. The amine emulsion prepared using this invention effectively solves the problems of poor storage stability and the influence of acid addition on film performance in current amine emulsion preparation methods.

Description

Technical Field

[0001] This invention relates to the field of coatings and adhesives, and in particular to an amine emulsion, its preparation method, and its application. Background Technology

[0002] Epoxy resins possess excellent mechanical properties and corrosion resistance, exhibit good adhesion to metals, and show minimal volume shrinkage during curing. Epoxy coatings made from epoxy resins have a wide range of applications. Traditional solvent-based epoxy coatings contain high levels of solvents, resulting in high VOC emissions and significant impacts on the environment and human health. Therefore, waterborne epoxy coatings using water as the dispersion medium have gained considerable attention. In many applications with less demanding conditions, they have replaced solvent-based epoxy resins, significantly reducing environmental pollution.

[0003] Amine curing agents are an important component of waterborne epoxy coatings. Currently, most amine curing agents used with waterborne epoxy resins are water-soluble, while only three foreign brands offer emulsion-type amine curing agents. Compared to water-soluble amine curing agents, the biggest advantages of emulsion-type amine curing agents are their anti-sagging properties, ease of thickening, and thicker film thickness, making them particularly suitable for curtain coating and other coating and adhesive applications requiring high film thickness. Currently, domestic research in this area is still in its early stages, and no stable products are available for sale. The main research challenge lies in balancing the stability and performance of the emulsion, namely, the selection of the emulsifier and its compatibility with the emulsified material.

[0004] Currently, some researchers have incorporated long hydrophilic links into amine curing agents to prepare self-emulsifying emulsion-type amine curing agents. However, due to their large molecular weight, self-emulsifying emulsions have high viscosity, making it difficult to produce high-solids-content curing agent emulsions. This leads to a high active hydrogen equivalent in the curing agent, reducing the product's cost-effectiveness. Other researchers have used non-reactive emulsifiers without amine groups to emulsify amine curing agents to prepare amine curing agent emulsions. However, these emulsifiers also lead to a decrease in coating film durability. Furthermore, CN201310426510.0 uses octadecylamine to end-cap epoxy-modified PEG2000 to prepare amine-containing reactive emulsifiers. These emulsifiers have an active hydrogen equivalent greater than 2000 g / eq, limited reactivity, and are close to non-reactive emulsifiers, exhibiting the same drawbacks as the aforementioned non-reactive emulsifiers.

[0005] Therefore, how to reduce the active hydrogen equivalent of emulsifiers while retaining their emulsifying ability in order to prepare stable and high-performance amine emulsions is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide an amine emulsion, its preparation method, and its application, addressing the shortcomings of existing technologies, thereby solving the problems of poor storage stability and poor performance in coatings and adhesives.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] The present invention provides an amine emulsion, which is prepared from raw materials comprising the following parts by weight: amine prepolymer A1-9 parts, amine prepolymer B1-9 parts, and water 5-10 parts;

[0009] The active hydrogen equivalent of the amine prepolymer A is in the range of 300 to 600 g / eq, including nonionic amine prepolymer A1 and / or ionic amine prepolymer A2;

[0010] The active hydrogen equivalent of the amine prepolymer B is in the range of 100–500 g / eq.

[0011] Preferably, the preparation method of the nonionic amine prepolymer A1 is as follows:

[0012] (1) An epoxy compound containing a hydrophilic segment is mixed with a first amine compound and subjected to an addition reaction to obtain an intermediate product with an epoxy end.

[0013] A second amine compound solution and an epoxy compound solution are mixed and subjected to an addition reaction to obtain an amine-terminated intermediate; the epoxy compound is an epoxy compound containing a hydrophilic segment or an epoxy compound containing a hydrophobic segment;

[0014] (2) The obtained amine-terminated intermediate and the epoxy-terminated intermediate are subjected to an addition reaction in a solvent to obtain a reaction solution.

[0015] (3) Add the epoxy compound containing hydrophobic segments to the reaction solution to carry out an addition reaction to obtain a nonionic amine prepolymer A1;

[0016] In step (1), the molar ratio of the first amine compound to the epoxy compound containing hydrophilic segments is 1 to 2.5:1; the molar ratio of the second amine compound to the epoxy compound is 1 to 2.5:1.

[0017] The molar ratio of the epoxy compound containing hydrophilic segments, the epoxy compound, and the epoxy compound containing hydrophobic segments is 1:0.20-0.30:0.05-0.25;

[0018] The addition reaction time is independently 2 to 5 hours;

[0019] In step (1), the epoxy compound containing hydrophilic segments is first heated to 45-50°C, and then the first amine compound is added; the addition reaction temperature for synthesizing the intermediate product with one end being epoxy is 60-70°C.

[0020] In step (1), the second amine compound solution is first heated to 50-60°C, and then an epoxy compound solution is added; the addition reaction temperature for synthesizing the amine-terminated intermediate is 60-65°C.

[0021] The temperature of the addition reaction in step (2) is 65-70°C;

[0022] The temperature of the addition reaction in step (3) is 70-75℃.

[0023] Preferably, the first amine compound and the second amine compound are independently one or more of polyetheramine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethanolamine, N-methylacetamide, and dipropylamine;

[0024] The epoxy compound containing hydrophilic segments is one or more of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0025] The epoxy compound containing hydrophobic segments is one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C10 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, glycidyl tert-carbonate, bisphenol A epoxy resin, phenolic epoxy resin, bisphenol F epoxy resin, and epoxidized vegetable oil.

[0026] Preferably, the amine prepolymer B is prepared by:

[0027] (1) An amine compound solution and a first epoxy compound solution containing hydrophobic segments are mixed and subjected to an addition reaction to obtain a reaction solution;

[0028] (2) Then add the second type of epoxy compound containing hydrophobic segments to the reaction solution to carry out an addition reaction to obtain amine prepolymer B;

[0029] The molar ratio of the first type of epoxy compound containing hydrophobic segments to the second type of epoxy compound containing hydrophobic segments is 1:1.0 to 1.4.

[0030] The total molar ratio of the amine compound to the first epoxy compound containing a hydrophobic segment and the second epoxy compound containing a hydrophobic segment is 1 to 2.5:1;

[0031] In step (1), the amine compound solution is first heated to 50-55°C, and then the first epoxy compound solution containing hydrophobic segments is added.

[0032] The addition reaction temperature in step (1) is 55–65°C; the addition reaction temperature in step (2) is 65–75°C.

[0033] The addition reaction takes 2 to 5 hours independently.

[0034] Preferably, the amine compound is one or more of diethylenetriamine, triethylenetetramine, N-aminoethylpiperazine, isophorone diamine, m-phenylenediamine and phenolic amines;

[0035] The first type of epoxy compound containing a hydrophobic segment and the second type of epoxy compound containing a hydrophobic segment are independently selected from one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C10 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, glycidyl tert-carbonate, bisphenol A epoxy resin, phenolic epoxy resin, bisphenol F epoxy resin, and epoxidized vegetable oil.

[0036] Preferably, the ionic amine prepolymer A2 is obtained by neutralizing the nonionic amine prepolymer A1 in an acidic solvent; the acidic solvent is a nitroalkane solvent.

[0037] Preferably, the amine emulsion contains 30-60% solids of amine prepolymer A and amine prepolymer B, 0-10% solvent, and 30-70% water.

[0038] The present invention also provides a method for preparing an amine emulsion, comprising the following steps: mixing amine prepolymer A and amine prepolymer B, and adding water to the mixture at a shear rate of 1000-4000 r / min to emulsify, thereby obtaining an amine emulsion.

[0039] During the mixing process, the temperature is first raised to 80-90℃ and stirred for 1.5-2.5 hours, then cooled to 40-45℃; during the emulsification process, the system temperature is 20-70℃ and the emulsification time is 20-40 minutes; the water dripping rate is 1-5 drops / s.

[0040] This invention also provides the application of amine emulsions in epoxy two-component coatings and adhesives.

[0041] The beneficial effects of this invention include:

[0042] (1) In this invention, amine prepolymer A with emulsifying ability and hydrophobic amine prepolymer B are prepared by using amine compounds and epoxy compounds. The two are mixed in a certain proportion, heated and stirred, and then an amine emulsion is prepared by phase inversion. By adjusting the difference in hydrophobicity between A and B, an amine emulsion with a particle size of less than 900 nm, stable storage, and excellent application performance can be obtained in the amine emulsion.

[0043] (2) This invention provides a method for preparing a high-performance amine emulsion with widely available raw materials. This method is simple and easy to implement. A stable amine emulsion is prepared using fewer hydrophilic chain ends.

[0044] (3) Compared with existing amine emulsions, the amine emulsion in this invention uses an amine prepolymer with a low active hydrogen content as an emulsifier. The emulsifier itself can be used alone as an epoxy curing agent. It is not easy to migrate during use and can impart excellent performance to the coating. The prepolymer used as an emulsifier has a similar structure to the prepolymer being emulsified, has high compatibility, and the resulting curing agent has excellent stability. Nonionic and ionic amine emulsions can be selectively prepared as needed. Detailed Implementation

[0045] The present invention provides an amine emulsion, which is prepared from raw materials comprising the following parts by weight: amine prepolymer A1-9 parts, amine prepolymer B1-9 parts, and water 5-10 parts;

[0046] The active hydrogen equivalent of the amine prepolymer A is in the range of 300 to 600 g / eq, including nonionic amine prepolymer A1 and / or ionic amine prepolymer A2;

[0047] The active hydrogen equivalent of the amine prepolymer B is in the range of 100–500 g / eq.

[0048] In this invention, the content of the amine prepolymer A is 1 to 9 parts, preferably 2 to 8 parts, and more preferably 3 to 7 parts.

[0049] In this invention, the active hydrogen equivalent of the amine prepolymer A is in the range of 300-600 g / eq, preferably 350-550 g / eq, and more preferably 400-500 g / eq.

[0050] In this invention, the content of the amine prepolymer B is 1 to 9 parts, preferably 2 to 8 parts, and more preferably 3 to 7 parts.

[0051] In this invention, the active hydrogen equivalent of the amine prepolymer B is in the range of 100-500 g / eq, preferably 150-450 g / eq, and more preferably 200-400 g / eq.

[0052] In this invention, the amine prepolymer A acts as an emulsifier for the amine prepolymer B; the hydrophobicity of the amine prepolymer B is greater than that of the amine prepolymer A.

[0053] In this invention, the water content is 5 to 10 parts, preferably 6 to 9 parts, and more preferably 7 to 8 parts.

[0054] In this invention, the preparation method of the nonionic amine prepolymer A1 is as follows:

[0055] (1) An epoxy compound containing a hydrophilic segment is mixed with a first amine compound and subjected to an addition reaction to obtain an intermediate product with an epoxy end.

[0056] A second amine compound solution and an epoxy compound solution are mixed and subjected to an addition reaction to obtain an amine-terminated intermediate; the epoxy compound is an epoxy compound containing a hydrophilic segment or an epoxy compound containing a hydrophobic segment;

[0057] (2) The obtained amine-terminated intermediate and the epoxy-terminated intermediate are subjected to an addition reaction in a solvent to obtain a reaction solution.

[0058] (3) Add the epoxy compound containing hydrophobic segments to the reaction solution to carry out an addition reaction to obtain a nonionic amine prepolymer A1;

[0059] In step (1), the molar ratio of the first amine compound to the epoxy compound containing hydrophilic segments is 1 to 2.5:1; the molar ratio of the second amine compound to the epoxy compound is 1 to 2.5:1.

[0060] The molar ratio of the epoxy compound containing hydrophilic segments, the epoxy compound, and the epoxy compound containing hydrophobic segments is 1:0.20-0.30:0.05-0.25;

[0061] The addition reaction time is independently 2 to 5 hours;

[0062] In step (1), the epoxy compound containing hydrophilic segments is first heated to 45-50°C, and then the first amine compound is added; the addition reaction temperature for synthesizing the intermediate product with one end being epoxy is 60-70°C.

[0063] In step (1), the second amine compound solution is first heated to 50-60°C, and then an epoxy compound solution is added; the addition reaction temperature for synthesizing the amine-terminated intermediate is 60-65°C.

[0064] The temperature of the addition reaction in step (2) is 65-70°C;

[0065] The temperature of the addition reaction in step (3) is 70-75℃.

[0066] In this invention, the molar ratio of the first amine compound to the epoxy compound containing hydrophilic segments is preferably 1 to 2.3:1, more preferably 1 to 2.0:1;

[0067] In this invention, the molar ratio of the second amine compound to the epoxide compound is preferably 1 to 2.2:1, and more preferably 1 to 2.0:1.

[0068] In this invention, the molar ratio of the second amine compound to the solvent in the second amine compound solution is 1:0.3 to 0.65, preferably 1:0.35 to 0.6, and more preferably 1:0.4 to 0.55.

[0069] In this invention, the molar ratio of the epoxy compound to the solvent in the epoxy compound solution is 1:0.8 to 1.8, preferably 1:0.9 to 1.7, and more preferably 1:1.1 to 1.5.

[0070] In this invention, in step (2), the mass ratio of the intermediate product with one end being epoxy to the solvent is 1:0.045 to 0.08, preferably 1:0.048 to 0.075, and more preferably 1:0.050 to 0.070.

[0071] In this invention, the molar ratio of the epoxy compound containing hydrophilic segments, the epoxy compound, and the epoxy compound containing hydrophobic segments is preferably 1:0.21-0.30:0.07-0.24, and more preferably 1:0.22-0.29:0.08-0.22.

[0072] In this invention, the addition reaction time in the preparation of the nonionic amine prepolymer A1 is 2 to 5 hours, preferably 2.5 to 4.5 hours, and more preferably 3 hours.

[0073] In this invention, in step (1) of preparing the nonionic amine prepolymer A1, the epoxy compound containing hydrophilic segments is first heated to 45-50°C, and then the first amine compound is added. The temperature after heating is preferably 46.5-48°C, and more preferably 46-48°C.

[0074] In this invention, the addition reaction temperature for synthesizing the intermediate product with one end being epoxy is 60-70°C, preferably 61-68°C, and more preferably 62-67°C.

[0075] In this invention, in step (1) of preparing the nonionic amine prepolymer A1, the second amine compound solution is first heated to 50-60°C, and then an epoxy compound solution is added. The temperature after heating is preferably 52-58°C, and more preferably 53-57°C.

[0076] In this invention, the addition reaction temperature for synthesizing the amine-terminated intermediate is 60–65°C, preferably 61–64°C, and more preferably 62–63°C.

[0077] In this invention, the temperature of the addition reaction in step (2) of preparing the nonionic amine prepolymer A1 is 65-70°C, preferably 66-69°C, and more preferably 67-68°C.

[0078] In this invention, the temperature of the addition reaction in step (3) of preparing the nonionic amine prepolymer A1 is 70-75°C, preferably 71-74°C, and more preferably 72-73°C.

[0079] In this invention, the first amine compound and the second amine compound are independently one or more of polyetheramine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethanolamine, N-methylacetamide, and dipropylamine;

[0080] In this invention, the epoxy compound containing hydrophilic segments used to prepare the nonionic amine prepolymer A1 is one or more of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0081] In this invention, the molecular weights of the polyethylene glycol diglycidyl ether and the polypropylene glycol diglycidyl ether are independently 700-800, preferably 710-790, and more preferably 720-780.

[0082] In this invention, the epoxy compound containing hydrophobic segments used to prepare the nonionic amine prepolymer A1 is one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C10 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, glycidyl tert-carbonate, bisphenol A epoxy resin, phenolic epoxy resin, bisphenol F epoxy resin, and epoxidized vegetable oil.

[0083] In this invention, the bisphenol A epoxy resin used to prepare the nonionic amine prepolymer A1 is preferably E-51 epoxy resin.

[0084] In this invention, the preparation method of the amine prepolymer B is as follows:

[0085] (1) An amine compound solution and a first epoxy compound solution containing hydrophobic segments are mixed and subjected to an addition reaction to obtain a reaction solution;

[0086] (2) Then add the second type of epoxy compound containing hydrophobic segments to the reaction solution to carry out an addition reaction to obtain amine prepolymer B;

[0087] The molar ratio of the first type of epoxy compound containing hydrophobic segments to the second type of epoxy compound containing hydrophobic segments is 1:1.0 to 1.4.

[0088] The total molar ratio of the amine compound to the first epoxy compound containing a hydrophobic segment and the second epoxy compound containing a hydrophobic segment is 1 to 2.5:1;

[0089] In step (1), the amine compound solution is first heated to 50-55°C, and then the first epoxy compound solution containing hydrophobic segments is added.

[0090] The addition reaction temperature in step (1) is 55–65°C; the addition reaction temperature in step (2) is 65–75°C.

[0091] The addition reaction takes 2 to 5 hours independently.

[0092] In this invention, the molar ratio of the first epoxy compound containing hydrophobic segments to the second epoxy compound containing hydrophobic segments is 1:1.0 to 1.4, preferably 1:1.1 to 1.3, and more preferably 1:1.1 to 1.2.

[0093] In this invention, the total molar ratio of the amine compound to the first epoxy compound containing a hydrophobic segment and the second epoxy compound containing a hydrophobic segment is 1 to 2.5:1, preferably 1 to 2.0:1, and more preferably 1 to 1.8:1.

[0094] In the present invention, in step (1) of preparing the amine prepolymer B1, the amine compound solution is first heated to 50-55°C, and then the first epoxy compound solution containing hydrophobic segments is added, preferably at 50.5-54.5°C, and more preferably at 51-54°C.

[0095] In this invention, the temperature of the addition reaction in step (1) of preparing the amine prepolymer B1 is 55-65°C, preferably 56-64°C, and more preferably 57-62°C; the temperature of the addition reaction in step (2) is 65-75°C, preferably 66-74°C, and more preferably 68-73°C.

[0096] In this invention, the addition reaction time for preparing the amine prepolymer B1 is independently 2 to 5 hours, preferably 2.5 to 4.5 hours, and more preferably 3 to 4 hours.

[0097] In this invention, the molar ratio of the amine compound to the solvent in the amine compound solution is 1:0.10 to 0.40, preferably 1:0.15 to 0.38, and more preferably 1:0.16 to 0.30.

[0098] In this invention, the molar ratio of the first epoxy compound containing hydrophobic segments to the solvent in the first epoxy compound solution containing hydrophobic segments is 1:0.40 to 0.80, preferably 1:0.45 to 0.70, and more preferably 1:0.50 to 0.65.

[0099] In this invention, the amine compound is one or more of diethylenetriamine, triethylenetetramine, N-aminoethylpiperazine, isophorone diamine, m-phenylenediamine, and phenolic amines;

[0100] In this invention, the first type of epoxy compound containing hydrophobic segments and the second type of epoxy compound containing hydrophobic segments are independently selected from one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C10 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, glycidyl tert-carbonate, bisphenol A epoxy resin, phenolic epoxy resin, bisphenol F epoxy resin, and epoxidized vegetable oil.

[0101] In this invention, the bisphenol A epoxy resin used to prepare the amine prepolymer B1 is preferably E-51 epoxy resin and / or E-44 epoxy resin.

[0102] In this invention, the epoxy equivalent of the epoxy compounds used to prepare the nonionic amine prepolymer A1 and amine prepolymer B is independently 100-2000 g / eq, preferably 200-1500 g / eq, and more preferably 300-1400 g / eq.

[0103] In this invention, the solvents used to prepare the nonionic amine prepolymer A1 and amine prepolymer B are independently one or more of acetone, butanone, methyl isobutyl ketone, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, cyclohexane, and benzyl alcohol.

[0104] In this invention, the ionic amine prepolymer A2 is obtained by neutralizing the nonionic amine prepolymer A1 in an acidic solvent; the acidic solvent is a nitroalkane solvent.

[0105] In this invention, the mass ratio of the nonionic amine prepolymer A1 to the acidic solvent is 100:4 to 10, preferably 100:5 to 8, and more preferably 100:6 to 7.

[0106] In this invention, the amine prepolymer A also includes a commercially available air-curing agent A721 for emulsifiable epoxy resin amines.

[0107] In this invention, the sum of the solid contents of amine prepolymer A and amine prepolymer B in the amine emulsion is 30-60%, preferably 32-58%, and more preferably 35-55%.

[0108] In this invention, the solvent content in the amine emulsion is 0-10%, preferably 0-9%, and more preferably 1-8%.

[0109] In this invention, the water content in the amine emulsion is 30-70%, preferably 35-65%, and more preferably 40-60%.

[0110] The present invention also provides a method for preparing an amine emulsion, comprising the following steps: mixing amine prepolymer A and amine prepolymer B, and adding water to the mixture at a shear rate of 1000-4000 r / min to emulsify, thereby obtaining an amine emulsion;

[0111] During the mixing process, the temperature is first raised to 80–90°C and stirred for 1.5–2.5 hours, then cooled to 40–45°C. During the emulsification process, the system temperature is 20–70°C, and the emulsification time is 20–40 minutes. The water is added at a rate of 1–5 drops / second.

[0112] In this invention, the shearing speed is preferably 1200-3800 r / min, and more preferably 1500-3500 r / min.

[0113] In this invention, the mixing process is first heated to 80-90°C, preferably 82-88°C, and more preferably 83-86°C.

[0114] In this invention, the stirring time during the mixing process is preferably 1.6 to 2.3 hours, and more preferably 1.8 to 2 hours.

[0115] In this invention, the emulsification time is preferably 25-35 min, and more preferably 28-33 min.

[0116] In this invention, the dripping rate of the water is preferably 2-5 drops / s, more preferably 3-4 drops / s. This invention also provides an application of amine emulsions in epoxy two-component coatings and adhesives.

[0117] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0118] Example 1

[0119] Preparation of nonionic amine prepolymer A11:

[0120] (1) 127g of polyethylene glycol diglycidyl ether was added to a three-necked flask equipped with a condenser and a constant pressure funnel. The temperature was raised to 48°C. 20.24g of dipropylamine was placed in the constant pressure funnel and slowly added dropwise to the flask. The addition was completed within half an hour. The temperature was then raised to 61°C and the reaction was allowed to proceed for 4 hours to obtain 57.98g of an intermediate product with an epoxy end.

[0121] (2) Add 8.9g of diethylenetriamine and 3g of butanone to a three-necked flask equipped with a condenser and a constant-pressure funnel. Heat to 52°C. Place 13.88g of E-51 epoxy resin and 3g of butanone into the constant-pressure funnel and slowly add them dropwise into the flask. Complete the addition within 1 hour. Then raise the temperature to 62°C and react for 3.5 hours. Next, place the intermediate product with one end being epoxy from step (1) and 3g of butanone into the constant-pressure funnel and slowly add them dropwise into the flask. Complete the addition within half an hour. Then raise the temperature to 67°C and react for 3 hours. Then, place 11.82g of C12-C14 alkyl glycidyl ether into the constant-pressure funnel and slowly add it dropwise into the flask. Complete the addition within half an hour. Then raise the temperature to 72°C and react for 3 hours to obtain prepolymer A11 with an active hydrogen equivalent of 518.39g / eq.

[0122] Preparation of prepolymer B1:

[0123] 17.86 g of triethylenetetramine, 20.79 g of isophorone diamine, and 3 g of butanone were added to a three-necked flask equipped with a condenser and a constant-pressure funnel. The temperature was raised to 55 °C. 41.07 g of E-51 epoxy resin and 5 g of butanone were placed in the constant-pressure funnel and slowly added dropwise to the flask. The addition was completed within 1 hour. The temperature was then raised to 65 °C, and the reaction was allowed to proceed for 2.5 hours. Next, 17.34 g of butyl glycidyl ether was placed in the constant-pressure funnel and slowly added dropwise to the flask, completed within half an hour. The temperature was then raised to 75 °C, and the reaction was allowed to proceed for 3 hours to obtain prepolymer B1 with an active hydrogen equivalent of 124.55 g / eq.

[0124] Preparation of emulsion A11B1:

[0125] 10g of amine prepolymer A11 and 40g of amine prepolymer B1 were added to a three-necked flask equipped with a constant pressure funnel. The mixture was first heated to 80℃ and stirred for 2 hours, then cooled to 40℃. 37g of deionized water was added dropwise while stirring at 4000r / min. The amine emulsion A11B1 was obtained by phase inversion, with an active hydrogen equivalent of 255.54g / eq.

[0126] Example 2

[0127] Preparation of nonionic amine prepolymer A12:

[0128] (1) 120g of polypropylene glycol diglycidyl ether was added to a three-necked flask equipped with a condenser and a constant pressure funnel. The temperature was raised to 45°C, and 21g of diethanolamine was placed in the constant pressure funnel and slowly added dropwise to the flask. The addition was completed within half an hour, and the temperature was raised to 70°C. The reaction was allowed to proceed for 4 hours. 55.52g of an intermediate product with an epoxy end was obtained.

[0129] (2) Add 12.62g of triethylenetetramine and 4g of ethylene glycol butyl ether to a three-necked flask equipped with a condenser and a constant-pressure funnel. Heat to 60°C. Place 13.88g of E-51 epoxy resin and 5g of ethylene glycol butyl ether into the constant-pressure funnel and slowly add them dropwise into the flask. Complete the addition within 1 hour. Then heat to 65°C and react for 3 hours. Next, place the intermediate product with one end being epoxy from step (1) and 4g of ethylene glycol butyl ether into the constant-pressure funnel and slowly add them dropwise into the flask. Complete the addition within half an hour. Then heat to 70°C and react for 2 hours. Then, place 7.43g of glycidyl tert-carbonate into the constant-pressure funnel and slowly add it dropwise into the flask. Complete the addition within half an hour. Then heat to 75°C and react for 3 hours to obtain prepolymer A12 with an active hydrogen equivalent of 356.83g / eq.

[0130] Preparation of prepolymer B2:

[0131] 8.32 g of diethylenetriamine, 10.99 g of m-phenylenediamine, 13.73 g of isophorone diamine, and 5 g of ethylene glycol butyl ether were added to a three-necked flask equipped with a condenser and a constant-pressure funnel. The temperature was raised to 52 °C. 20.35 g of E-51 epoxy resin, 24.98 g of E-44 epoxy resin, and 7 g of ethylene glycol butyl ether were placed in the constant-pressure funnel and slowly added dropwise to the flask. The addition was completed within 1 hour. The temperature was then raised to 57 °C, and the reaction was allowed to proceed for 3 hours. Next, 27.67 g of glycidyl tert-carbonate was placed in the constant-pressure funnel and slowly added dropwise to the flask, completed within half an hour. The temperature was then raised to 70 °C, and the reaction was allowed to proceed for 4 hours, yielding amine prepolymer B2 with an active hydrogen equivalent of 163.94 g / eq.

[0132] Preparation of emulsion A12B2:

[0133] 10g of amine prepolymer A12 and 35g of amine prepolymer B2 were added to a three-necked flask equipped with a constant pressure funnel. The mixture was first heated to 80℃ and stirred for 2.5h, then cooled to 45℃. 33g of deionized water was added dropwise while stirring at 2000r / min. The amine emulsion A12B2 was obtained by phase inversion, with an active hydrogen equivalent of 322.96g / eq.

[0134] Example 3

[0135] Preparation of nonionic amine prepolymer A13:

[0136] (1) 127g of polyethylene glycol diglycidyl ether was added to a three-necked flask equipped with a condenser and a constant pressure funnel. The temperature was raised to 50°C. 14.62g of N-methylacetamide was placed in the constant pressure funnel and slowly added dropwise to the flask. The addition was completed within half an hour. The temperature was then raised to 60°C and the reaction was allowed to proceed for 5 hours to obtain 55.76g of an intermediate product with an epoxy end.

[0137] (2) Add 4.45g of diethylenetriamine, 6.31g of triethylenetetramine, and 5g of propylene glycol ethyl ether to a three-necked flask equipped with a condenser and a constant-pressure funnel. Heat the flask to 60°C. Place 11.25g of 1,6-hexanediol diglycidyl ether and 5g of propylene glycol ethyl ether into the constant-pressure funnel and slowly add them dropwise into the flask. Complete the addition within 1 hour, maintaining the temperature at 60°C for 3 hours. Then, place the intermediate product with one end being epoxy from step (1) and 3g of propylene glycol ethyl ether into the constant-pressure funnel and slowly add them dropwise into the flask. Complete the addition within half an hour, then heat the flask to 65°C and react for 3 hours. Finally, place 2.41g of allyl glycidyl ether into the constant-pressure funnel and slowly add it dropwise into the flask. The addition was completed within half an hour, and the temperature was raised to 70°C. The reaction was carried out for 3 hours to obtain prepolymer A13 with an active hydrogen equivalent of 341.93 g / eq.

[0138] Preparation of prepolymer B3:

[0139] 8.32 g of diethylenetriamine, 13.73 g of isophorone diamine, 10.42 g of N-aminoethylpiperazine, and 5 g of propylene glycol ethyl ether were added to a three-necked flask equipped with a condenser and a constant-pressure funnel. The temperature was raised to 50 °C. 50 g of E-44 epoxy resin and 7 g of propylene glycol ethyl ether were placed in the constant-pressure funnel and slowly added dropwise to the flask. The addition was completed within 1 hour. The temperature was then raised to 55 °C, and the reaction was allowed to proceed for 4 hours. Then, 20.48 g of phenyl glycidyl ether was placed in the constant-pressure funnel and slowly added dropwise to the flask, completed within half an hour. The temperature was then raised to 65 °C, and the reaction was allowed to proceed for 5 hours, yielding prepolymer B3 with an active hydrogen equivalent of 192.58 g / eq.

[0140] Preparation of emulsion A13B3:

[0141] 10g of nonionic amine prepolymer A13 and 30g of amine prepolymer B3 were added to a three-necked flask equipped with a constant pressure funnel. The mixture was first heated to 80℃ and stirred for 1.5h, then cooled to 45℃. 30g of deionized water was added dropwise while stirring at 1500r / min. The amine emulsion A13B3 was obtained by the phase inversion method, with an active hydrogen equivalent of 378.33g / eq.

[0142] Example 4

[0143] Preparation of ionic amine prepolymer A21:

[0144] Add 6g of nitropropane solvent to 100g of A11 and stir thoroughly to obtain amine prepolymer A21, with an active hydrogen equivalent of 549.49g / eq.

[0145] Preparation of emulsion A21B3:

[0146] 8g of amine prepolymer A21 and 40g of amine prepolymer B3 were added to a three-necked flask equipped with a constant pressure funnel. The mixture was first heated to 85℃ and stirred for 2 hours, then cooled to 42℃. 35g of deionized water was added dropwise while stirring at 3000r / min. The ionic emulsion A21B3 was obtained by the phase inversion method, with an active hydrogen equivalent of 374.23g / eq.

[0147] Example 5

[0148] Preparation of emulsion A721B3:

[0149] 10g of amine prepolymer A721 (air chemical curing agent product) and 50g of amine prepolymer B3 were added to a three-necked flask equipped with a constant pressure funnel. The mixture was heated to 90℃ and stirred for 2 hours. Then, the temperature was lowered to 40℃. 55g of deionized water was added dropwise while stirring at 2500r / min. An amine emulsion was obtained by the phase inversion method.

[0150] Performance Testing: Preparation of Emulsion-Curing Waterborne Epoxy Coatings and Preparation of Coating Samples

[0151] Table 1 Formulation composition of two-component waterborne epoxy coatings

[0152]

[0153] Prepare two-component waterborne epoxy coatings according to the proportions shown in the table above. First, prepare resin-free color paste: disperse the wetting and dispersing agent and defoamer in water at a dispersion speed of 500-600 r / min for 5-6 min, increase the speed to 600-1000 r / min, add pigments and fillers such as zinc phosphate, wollastonite, and titanium dioxide, and disperse at high speed of 1000-1500 r / min for 12-15 min. Replace with a grinding and dispersing disc, add zirconium beads, adjust the speed to 2500-3000 r / min, disperse until the color paste fineness is ≤20 μm, and filter. Next, mix the epoxy emulsion with the color paste, and then add the film-forming aid, defoamer, substrate wetting agent, leveling agent, and thickener in sequence. Disperse at 800-1000 r / min for 20-30 min to ensure that each component is evenly dispersed to obtain epoxy component A. Before construction, add the amine curing agent according to the specified ratio, stir evenly, adjust the filter, and spray it onto the polished cold-rolled steel plate. After leveling at room temperature, bake at 80℃ for 2 hours, and then cure at room temperature for 24 hours. Test the performance data according to the corresponding national standards.

[0154] Table 2 Apparent and storage stability properties of emulsions

[0155]

[0156]

[0157] Table 3. Coating properties of emulsion-cured waterborne epoxy resin (AQUAER3012, Jiangsu Fuqisen product)

[0158]

[0159] As can be seen from the above embodiments, the present invention provides an amine emulsion, its preparation method, and its application. Experimental data shows that the amine emulsion prepared by the present invention exhibits a storage stability of more than 28 days at 50°C. When applied to coatings, it produces a smooth, defect-free film with a pencil hardness of 2H, good gloss, and excellent water and salt spray resistance. Therefore, the amine emulsion prepared by the present invention demonstrates excellent thermal storage stability, good application performance, and superior durability.

[0160] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An amine emulsion, characterized in that, It is prepared from raw materials containing the following parts by weight: amine prepolymer A1-9 parts, amine prepolymer B1-9 parts, and water 5-10 parts; The active hydrogen equivalent of the amine prepolymer A is in the range of 300 to 600 g / eq, including nonionic amine prepolymer A1 and / or ionic amine prepolymer A2; The active hydrogen equivalent of the amine prepolymer B is in the range of 100–500 g / eq; The ionic amine prepolymer A2 is obtained by neutralizing the nonionic amine prepolymer A1 in an acidic solvent; the acidic solvent is a nitroalkane solvent. The preparation method of the nonionic amine prepolymer A1 is as follows: (1) An epoxy compound containing a hydrophilic segment is mixed with a first amine compound and subjected to an addition reaction to obtain an intermediate product with an epoxy end. A second amine compound solution and an epoxy compound solution are mixed and subjected to an addition reaction to obtain an amine-terminated intermediate; the epoxy compound is an epoxy compound containing a hydrophilic segment or an epoxy compound containing a hydrophobic segment; (2) The obtained amine-terminated intermediate and the epoxy-terminated intermediate are subjected to an addition reaction in a solvent to obtain a reaction solution. (3) Add the epoxy compound containing hydrophobic segments to the reaction solution to carry out an addition reaction to obtain a nonionic amine prepolymer A1; The preparation method of the amine prepolymer B is as follows: S1) An amine compound solution and a first epoxy compound solution containing hydrophobic segments are mixed and subjected to an addition reaction to obtain a reaction solution; S2) Then, the second type of epoxy compound containing hydrophobic segments is added to the reaction solution to carry out an addition reaction, and amine prepolymer B is obtained.

2. The amine emulsion according to claim 1, characterized in that, In the preparation method of the nonionic amine prepolymer A1, in step (1), the molar ratio of the first amine compound to the epoxy compound containing hydrophilic segments is 1 to 2.5:1; The molar ratio of the second type of amine compound to the epoxide compound is 1–2.5:1; The molar ratio of the epoxy compound containing hydrophilic segments, the epoxy compound, and the epoxy compound containing hydrophobic segments is 1:0.20-0.30:0.05-0.25; The addition reaction time is independently 2 to 5 hours; In step (1), the epoxy compound containing hydrophilic segments is first heated to 45-50°C, and then the first amine compound is added; the addition reaction temperature for synthesizing the intermediate product with one end being epoxy is 60-70°C. In step (1), the second amine compound solution is first heated to 50-60°C, and then an epoxy compound solution is added; the addition reaction temperature for synthesizing the amine-terminated intermediate is 60-65°C. The temperature of the addition reaction in step (2) is 65-70°C; The temperature of the addition reaction in step (3) is 70-75℃.

3. The amine emulsion according to claim 2, characterized in that, The first amine compound and the second amine compound are independently one or more of the following: polyetheramine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethanolamine, N-methylacetamide, and dipropylamine; The epoxy compound containing hydrophilic segments is one or more of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. The epoxy compound containing hydrophobic segments is one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C10 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, glycidyl tert-carbonate, bisphenol A epoxy resin, phenolic epoxy resin, bisphenol F epoxy resin, and epoxidized vegetable oil.

4. The amine emulsion according to claim 1, characterized in that, In the preparation method of amine prepolymer B, the molar ratio of the first epoxy compound containing hydrophobic segments to the second epoxy compound containing hydrophobic segments is 1:1.0 to 1.

4. The total molar ratio of the amine compound to the first epoxy compound containing a hydrophobic segment and the second epoxy compound containing a hydrophobic segment is 1 to 2.5:1; In step S1), the amine compound solution is first heated to 50-55°C, and then the first epoxy compound solution containing hydrophobic segments is added. The temperature of the addition reaction in step S1) is 55–65°C; the temperature of the addition reaction in step S2) is 65–75°C. The addition reaction takes 2 to 5 hours independently.

5. The amine emulsion according to claim 4, characterized in that, The amine compound is one or more of diethylenetriamine, triethylenetetramine, N-aminoethylpiperazine, isophorone diamine, m-phenylenediamine, and phenolic amines; The first type of epoxy compound containing a hydrophobic segment and the second type of epoxy compound containing a hydrophobic segment are independently selected from one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C10 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, glycidyl tert-carbonate, bisphenol A epoxy resin, phenolic epoxy resin, bisphenol F epoxy resin, and epoxidized vegetable oil.

6. The amine emulsion according to any one of claims 1 to 5, characterized in that, The amine emulsion contains 30-60% solids of amine prepolymer A and amine prepolymer B, 0-10% solvent, and 30-70% water.

7. The method for preparing the amine emulsion according to any one of claims 1 to 6, characterized in that, Includes the following steps: Amine prepolymer A and amine prepolymer B are mixed, and water is added to the mixture at a shear rate of 1000-4000 r / min to emulsify it, thus obtaining an amine emulsion. During the mixing process, the temperature is first raised to 80-90℃ and stirred for 1.5-2.5 hours, then cooled to 40-45℃; during the emulsification process, the system temperature is 20-70℃ and the emulsification time is 20-40 minutes; the water dripping rate is 1-5 drops / s.

8. The use of the amine emulsion according to any one of claims 1 to 6 in epoxy two-component coatings and adhesives.

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