Preparation method and application of high-solid-content waterborne epoxy emulsion

Abstract

The invention discloses a high-solid-content waterborne epoxy emulsion which is prepared from the following components in parts by weight: 10 parts of a waterborne epoxy emulsifier, 50-65 parts of bisphenol A epoxy resin, 3-15 parts of hyperbranched polyether epoxy resin and 20-25 parts of deionized water. According to the high-solid-content waterborne epoxy emulsion, the viscosity of an emulsification system can be greatly reduced due to the hyperbranched structure of the high-solid-content waterborne epoxy emulsion, so that the stable emulsion with smaller particle size is prepared, cavities contained in the emulsion can effectively toughen an epoxy coating, the crosslinking density of the coating can be improved due to rich epoxy end groups, the coating can be cured more sufficiently, and the service life of the coating is prolonged. The barrier property of the coating is further improved, and the coating has good use value in the actual use process. The solid content of the hyperbranched polyether waterborne epoxy emulsion prepared by the preparation method disclosed by the invention is up to 75% or above, the hyperbranched polyether waterborne epoxy emulsion has excellent stability, and a cured coating has excellent toughness and medium resistance after actual use.

Description

Technical Field

[0001] The present invention relates to the technical field of water-based coatings, and in particular to a preparation method and application of a high-solid-content water-based epoxy emulsion. Background Art

[0002] Waterborne epoxy coatings use water instead of solvent as a dispersion medium, which is more economical and environmentally friendly. It is one of the hottest trends to replace solvent-based epoxy coatings. However, the defects of waterborne epoxy coatings are also obvious: (1) Unlike solvent-based epoxy coatings, waterborne epoxy coatings are polydisperse systems. During the curing process, the curing agent molecules first contact and react with the surface of the epoxy particles, and then gradually diffuse into the interior of the particles to continue the reaction. During this process, the molecular weight of the epoxy resin increases, and the interfacial viscosity increases, which hinders the diffusion of the curing agent, making it difficult for the interior of the particles to fully participate in the curing, and the fusion between the particles is difficult. The final film is prone to micropores and defects, resulting in a decrease in overall performance; (2) The inherent brittleness of waterborne epoxy resins leads to poor wear resistance of the paint film, which limits its application in floor coatings. At present, waterborne epoxy resins can be toughened by introducing flexible curing agents, reactive diluents, inorganic nanoparticles, waterborne polyurethanes, rubber emulsions, etc.

[0003] In recent years, hyperbranched polymers, as a new type of modifier, have received widespread attention in the field of epoxy resin reinforcement and toughening. Hyperbranched polymers contain a large number of intramolecular cavities, which can increase the free volume of epoxy cured products and improve the toughness of the cured products. The abundant active end groups (hydroxyl, carboxyl, amino, and epoxy groups) of hyperbranched polymers can participate in the crosslinking and curing of the epoxy matrix, increasing the crosslink density of the cured product. Among them, epoxy-terminated hyperbranched polymers have the best compatibility with epoxy resins and can achieve reinforcement and toughening of epoxy cured products without causing phase separation. In addition, hyperbranched polymers also have a spherical branched topology, which can greatly reduce chain entanglement and bring better processing fluidity to the resin system. However, these studies have all been conducted in homogeneous systems, and there is still little research on hyperbranched epoxy resin-modified waterborne epoxy coatings at home and abroad. Zhang Di, Wang Yuan, and others have explored this area. They synthesized several hyperbranched polyether epoxy resins from dihydric phenols and trimethylolpropane triglycidyl ether and added them to a waterborne epoxy system, successfully preparing stable emulsions with relatively low particle sizes. However, the high viscosity of the synthesized hyperbranched epoxy resins increases the viscosity of the emulsified system, making it difficult to prepare high-solids waterborne epoxy emulsions. This has limited the application of hyperbranched epoxy resins in waterborne epoxy floor coatings. Summary of the Invention

[0004] To address the aforementioned issues in the prior art, the present invention provides a method for preparing a high-solids aqueous epoxy emulsion and its application. Based on a proton transfer polymerization mechanism, the present invention synthesizes a hyperbranched polyether epoxy resin via a one-pot process in the absence of solvents and without the need for purification. The resulting resin is then used to modify an aqueous epoxy emulsion, successfully preparing a high-solids aqueous epoxy emulsion. The high-solids aqueous epoxy emulsion is then compounded with a waterborne epoxy curing agent to prepare a waterborne epoxy floor coating exhibiting excellent toughness, hardness, wear resistance, and chemical resistance.

[0005] The technical solutions of the present invention are as follows:

[0006] The first object of the present invention is a high-solid aqueous epoxy emulsion, which is made of the following components in parts by weight:

[0007]

[0008] The hyperbranched polyether epoxy resin has a molecular weight of 2000-2800 g / mol, an epoxy value of 0.15-0.26 mol / 100 g, and a branching degree of 0.4-0.52.

[0009] In one embodiment of the present invention, the water-based epoxy emulsifier is one or more of AnquaEM45 emulsifier, Solvay-0092 emulsifier, and Naisol emulsifier.

[0010] In one embodiment of the present invention, the bisphenol A epoxy resin is one or more of E20 epoxy resin, E44 epoxy resin, and E51 epoxy resin.

[0011] In one embodiment of the present invention, the hyperbranched polyether epoxy resin is prepared by the following method:

[0012] The polyol, difunctional epoxy compound, branched monofunctional epoxy compound and catalyst are mixed, maintained in a nitrogen atmosphere, and reacted at 140-180° C. for 6-36 hours to obtain a hyperbranched polyether epoxy resin.

[0013] In one embodiment of the present invention, the polyol is one or more of trimethylolpropane, trimethylolethane, and glycerol.

[0014] In one embodiment of the present invention, the difunctional epoxy compound is one or more of ethylene glycol diglycidyl ether and 1,4-butanediol diglycidyl ether.

[0015] In one embodiment of the present invention, the branched monofunctional epoxy compound is versatile glycidyl carbonate.

[0016] In one embodiment of the present invention, the molar ratio of the polyol to the difunctional epoxy compound is 1:2-3.

[0017] In one embodiment of the present invention, the molar ratio of the polyol to the branched monofunctional epoxy compound is 1:0.1-1.

[0018] In one embodiment of the present invention, the catalyst is one or more of tetrabutylammonium bromide and triphenylphosphine.

[0019] In one embodiment of the present invention, the amount of the catalyst added is 0.5 to 1.5 wt % of the total mass of the reaction monomers.

[0020] The total mass of the reaction monomers is the total mass of the polyol, the difunctional epoxy compound and the branched monofunctional epoxy compound.

[0021] In one embodiment of the present invention, no solvent is required during the reaction process, and the aqueous epoxy emulsion can be directly used for the subsequent preparation of the aqueous epoxy emulsion after the reaction is completed.

[0022] In one embodiment of the present invention, the synthetic route of the hyperbranched polyether epoxy resin is:

[0023]

[0024] A second object of the present invention is to provide a method for preparing the high-solid aqueous epoxy emulsion, comprising the following steps:

[0025] Mix 10 parts of water-based epoxy emulsifier, 50-65 parts of bisphenol A epoxy resin, and 3-15 parts of hyperbranched polyether epoxy resin, raise the temperature to 40°C, and stir at a low speed;

[0026] After mixing evenly, increase the stirring speed and add deionized water dropwise under high shear. After the emulsion undergoes phase reversal from oil-in-water to water-in-oil, stop adding deionized water and maintain the current high speed shear for 2 hours.

[0027] After the shearing is completed, the rotation speed is reduced to 800 rpm, and deionized water is added to continue dispersion for 0.5 h, and the solid content of the emulsion is adjusted to 75 wt %, thereby obtaining the high-solid content aqueous epoxy emulsion;

[0028] The amount of deionized water used in the preparation process is 20 to 25 parts.

[0029] In one embodiment of the present invention, the rotation speed of the low-speed stirring is 800 rpm and the time is 0.5 h.

[0030] In one embodiment of the present invention, the high-speed shearing speed is 2000-2500 rpm, and the time is 2.2-2.5 hours; the time taken to reach the phase inversion point is 10-30 minutes, and the time taken for uniform dispersion after stopping the addition of water is 2 hours.

[0031] In one embodiment of the present invention, an epoxy emulsion is prepared using a phase inversion method. Specifically, after the epoxy resin and emulsifier are uniformly mixed, deionized water is slowly added to the system at a certain shear rate. At this time, the water droplets will disperse in the epoxy resin under the action of shear force and emulsifier, forming an oil-in-water system (W / O). When the water content in the system gradually increases and reaches a critical point (phase inversion point), the water will transform from a dispersed phase to a continuous phase, forming an oil-in-water system (O / W). During this period, the viscosity of the system is observed. When the viscosity of the system drops sharply, a drop of emulsion is drawn and dropped into deionized water. If the emulsion can quickly disperse in the aqueous phase, it indicates that the system has transformed from a W / O state to an O / W state, that is, the emulsion has reached the phase inversion point.

[0032] In one embodiment of the present invention, the rotation speed of 800 rpm in the pre-mixing stage is to uniformly disperse the epoxy resin and the emulsifier. The rotation speed is gradually increased to 2000-2500 rpm in the water addition stage to ensure that the water droplets are evenly dispersed and form an emulsion with smaller particle size. Finally, the speed is reduced to 800 rpm to further control the solid content of the system and form a stable and uniform oil-in-water emulsion.

[0033] The third object of the present invention is to provide an application of the above-mentioned high-solid aqueous epoxy emulsion, wherein the high-solid aqueous epoxy emulsion is compounded with a water-based epoxy curing agent to prepare a two-component water-based epoxy floor coating.

[0034] The fourth object of the present invention is to provide a two-component waterborne epoxy floor coating containing the above-mentioned high-solid aqueous epoxy emulsion, comprising component A and component B, component A contains a waterborne epoxy resin curing agent, and component B is the high-solid aqueous epoxy emulsion.

[0035] In one embodiment of the present invention, component A includes a water-based epoxy curing agent, ethylene glycol butyl ether, deionized water, silica powder, and talc.

[0036] In one embodiment of the present invention, component A includes 10 to 12 parts of a water-based epoxy curing agent, 3 parts of ethylene glycol butyl ether, 26 parts of deionized water, 50 parts of silica powder, and 11 parts of talc.

[0037] In one embodiment of the present invention, component A and component B are mixed at a molar ratio of active hydrogen to epoxy equivalent of 1 to 1.2:1.

[0038] In one embodiment of the present invention, the waterborne epoxy floor coating further includes an additive, such as one or more defoaming agents and dispersants.

[0039] The beneficial technical effects of the present invention are:

[0040] The hyperbranched polyether epoxy resin of the present invention is prepared by the A2+B3 method. The synthesis process is solvent-free, the steps are simple, the raw materials are readily available, and the resin has great commercial potential.

[0041] The flexible skeleton and branched topological structure of the hyperbranched polyether epoxy resin of the present invention give it low viscosity characteristics, which can effectively reduce the viscosity of the emulsification system, thereby realizing the preparation of high-solid aqueous epoxy emulsion; the abundant epoxy end groups give it good compatibility with bisphenol A epoxy resin, and after participating in the curing as a modifier, it can increase the cross-linking density of the cured product, making the coating denser, thereby improving the barrier performance of the coating to corrosive media; the flexible chain segments and intramolecular cavities can absorb impact energy, thereby improving the toughness and wear resistance of the cured product; the fatty chain segments in tertiary carbonate glycidyl ester can increase the hydrophobicity of the coating and improve the chemical resistance of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The infrared spectrum of the hyperbranched polyether epoxy resin prepared in Example 1;

[0043] Figure 2 The NMR spectrum of the hyperbranched polyether epoxy resin obtained in Example 1 is shown;

[0044] Figure 3 GPC elution curves of the hyperbranched polyether epoxy resins obtained in Examples 1 and 6-7. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0046] Unless otherwise specified, the synthetic raw materials involved in the present invention can be obtained from commercial sources. Table 1 shows the raw materials involved in implementing the method.

[0047] Table 1

[0048] Experimental raw materials Specification Manufacturer Trimethylolpropane 98％ Shanghai MacLean Biochemical Technology Co., Ltd. Glycerol 99％ Shanghai MacLean Biochemical Technology Co., Ltd. Trimethylolethane 97％ Shanghai Aladdin Biochemical Technology Co., Ltd. Ethylene glycol diglycidyl ether analytically pure Shanghai MacLean Biochemical Technology Co., Ltd. 1,4-Butanediol diglycidyl ether 99％ Shanghai MacLean Biochemical Technology Co., Ltd. Glycidyl ester of tert-butyl carbonate 99％ Shanghai MacLean Biochemical Technology Co., Ltd. Tetrabutylammonium bromide 99％ Shanghai Aladdin Biochemical Technology Co., Ltd. Triphenylphosphine 99％ Shanghai Aladdin Biochemical Technology Co., Ltd. AnquaEM45 emulsifier Industrial grade Provided by Yangnong Kumho Chemical Co., Ltd. E51 bisphenol A epoxy resin Industrial grade Yangnong Kumho Chemical Co., Ltd. Ethylene glycol butyl ether analytically pure Shanghai MacLean Biochemical Technology Co., Ltd. Waterborne epoxy curing agent YNCA701 Industrial grade Yangnong Kumho Chemical Co., Ltd. Silica powder Industrial grade Yangnong Kumho Chemical Co., Ltd. talcum powder Industrial grade Yangnong Kumho Chemical Co., Ltd. Defoaming agent (BYK-028) Industrial grade BYK Chemicals of Germany Dispersant (BYK-190) Industrial grade BYK Chemicals of Germany

[0049] Examples 1 to 13 are the preparation of hyperbranched polyether epoxy resins. Examples 14 to 18 are the preparation of waterborne epoxy emulsions. Examples 19 to 23 are the preparation methods of waterborne epoxy floor paints.

[0050] Example 1

[0051] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0052] 5.36g of trimethylolpropane, 17.42g of ethylene glycol diglycidyl ether, 4.57g of versatate glycidyl ether, and 0.27g of tetrabutylammonium bromide were placed in a reactor and reacted at 160°C for 12 hours under a nitrogen atmosphere. After completion, a light yellow, transparent liquid was obtained, which is the hyperbranched polyether epoxy resin. Its physical and chemical properties are shown in Table 2.

[0053] Example 2

[0054] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0055] In this example, based on Example 1, the reaction time was changed from 12 h to 24 h, and the other conditions were the same as those in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0056] Example 3

[0057] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0058] In this example, based on Example 1, the reaction time was changed from 12 h to 36 h, and the other conditions were the same as those in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0059] Example 4

[0060] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0061] In this example, based on Example 1, the reaction temperature was changed from 160° C. to 140° C., the reaction time was extended from 12 h to 24 h, and other conditions were the same as those in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0062] Example 5

[0063] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0064] In this example, based on Example 1, the reaction temperature was changed from 160° C. to 180° C., the reaction time was shortened from 12 h to 6 h, and the other conditions were the same as those in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0065] Example 6

[0066] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0067] In this example, based on Example 1, trimethylolpropane was replaced with glycerol, the added amount was changed to 3.68 g, and the added amount of tetrabutylammonium bromide was reduced to 0.26 g. Other conditions were changed as shown in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0068] Example 7

[0069] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0070] In this example, based on Example 1, trimethylolpropane was replaced with trimethylolethane, and the added amount was changed to 4.81 g. Other conditions were the same as those in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0071] Example 8

[0072] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0073] In this example, based on Example 1, ethylene glycol diglycidyl ether was replaced with 1,4-butanediol diglycidyl ether, the addition amount was changed to 20.22 g, and the addition amount of tetrabutylammonium bromide was increased to 0.30 g. Other conditions were the same as those in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0074] Example 9

[0075] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0076] 5.36 g of trimethylolpropane, 20.88 g of ethylene glycol diglycidyl ether, 3.04 g of versatate glycidyl ester and 0.29 g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0077] Example 10

[0078] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0079] 5.36 g of trimethylolpropane, 20.88 g of ethylene glycol diglycidyl ether, 0.91 g of versatate glycidyl ester, and 0.27 g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0080] Example 11

[0081] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0082] 5.36 g of trimethylolpropane, 13.92 g of ethylene glycol diglycidyl ether, 4.57 g of versatate glycidyl ester and 0.12 g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0083] Example 12

[0084] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0085] 5.36 g of trimethylolpropane, 17.42 g of ethylene glycol diglycidyl ether, 10.14 g of versatate glycidyl ester and 0.49 g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0086] Example 13

[0087] A method for preparing a hyperbranched polyether epoxy resin comprises the following steps:

[0088] 5.36 g of trimethylolpropane, 17.42 g of ethylene glycol diglycidyl ether, 4.57 g of versatate glycidyl ester and 0.27 g of triphenylphosphine were weighed and placed in a reactor. Other conditions were as shown in Example 1. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 2.

[0089] Comparative Example 1

[0090] Weigh 5.36g of trimethylolpropane, 17.42g of ethylene glycol diglycidyl ether, and 0.23g of tetrabutylammonium bromide into a reactor and react at 160°C for 12 hours under a nitrogen atmosphere. Upon completion, a pale yellow, transparent liquid was obtained, which is the hyperbranched polyether epoxy resin. Its physical and chemical properties are shown in Table 2.

[0091] Determination of epoxy value: The epoxy value of the polymer was determined according to method A in GB / T1677-2008.

[0092] Table 2 shows the physical and chemical data of the hyperbranched polyether epoxy resins prepared in Examples 1-13. The number average molecular weight of the hyperbranched polyether epoxy resins ranged from 2000 to 2800, indicating a moderate molecular weight. The viscosity was approximately 2 Pa·s. Compared with Comparative Example 1, the addition of tert-butyl glycidyl carbonate further reduced the viscosity. The degree of branching in all examples was above 0.4, consistent with the structural characteristics of hyperbranched polyether epoxy resins. The hyperbranched polyether epoxy resins exhibited good compatibility with bisphenol A epoxy resins, and the amount of hyperbranched polyether epoxy resin added could be adjusted based on the application in the waterborne epoxy coating. Figure 1 The infrared spectrum of Example 1 shows that at 3200 cm -1 ~3600cm-1 The stretching vibration peak of hydroxyl group appears at 2960cm -1 、2930cm -1 The stretching vibration peaks of methyl and methylene are at 910 cm -1 The peak at is the characteristic peak of the epoxy group retained by the reaction, and the infrared spectrum further proves the molecular structure of the sample. Figure 2 The NMR spectrum of Example 1 shows a large number of fatty chain segments, ether bonds, and secondary hydroxyl groups in the structure of Example 1, resulting in a strong characteristic peak at 3.20-4.20 ppm, a signal peak corresponding to the methyl group at 0.75 ppm, and two singlets at 2.55-2.90 ppm corresponding to the two proton peaks of the methylene group in the epoxy group. In addition, the hyperbranched polymer is composed of branching units (D), linear units (L), and terminal units (T). Since the chemical shift of the protons on the methylene groups adjacent to the methyl groups on trimethylolpropane varies significantly under these three different chemical environments, the degree of branching of Example 1 can be calculated using the formula DB = (D + T) / (D + T + L) to be 0.45. Figure 3 1 is the GPC elution curve of Example 1, Example 6 and Example 7. It can be seen that the relative molecular mass of the samples is between 2300 and 2400 g / mol.

[0093] Table 2

[0094]

[0095] Example 14

[0096] In this embodiment, 3g of AnquaEM45 emulsifier, 1g of the hyperbranched polyether epoxy resin prepared in Example 1, and 19g of bisphenol A epoxy resin were weighed into a dispersion tank and heated to 40°C with stirring. After all components were evenly mixed, the stirring rate was increased and deionized water was slowly added dropwise under high-speed shearing at 200rpm. After the emulsion phase was reversed from oil-in-water to water-in-oil, the addition of water was stopped and the current high-speed shearing was maintained for 2h. After the shearing was completed, the speed was reduced to 800rpm, and water was continued to be added for dispersion for 0.5h. The solid content of the emulsion was adjusted to 75wt%, thus obtaining a stable water-based epoxy emulsion. The relevant properties of the emulsion are shown in Table 3

[0097] Example 15

[0098] In this example, 3 g of AnquaEM45 emulsifier, 2 g of the hyperbranched polyether epoxy resin prepared in Example 1, and 18 g of bisphenol A epoxy resin were weighed into a dispersion tank, heated to 40° C. and stirred. The remaining preparation process was the same as in Example 14. The relevant properties of the obtained emulsion are shown in Table 3.

[0099] Example 16

[0100] In this example, 3 g of AnquaEM45 emulsifier, 4 g of the hyperbranched polyether epoxy resin prepared in Example 1, and 16 g of bisphenol A epoxy resin were weighed into a dispersion tank, heated to 40° C. and stirred. The remaining preparation process was the same as in Example 14. The relevant properties of the obtained emulsion are shown in Table 3.

[0101] Example 17

[0102] In this example, 3 g of AnquaEM45 emulsifier, 1 g of the hyperbranched polyether epoxy resin prepared in Example 9, and 19 g of bisphenol A epoxy resin were weighed into a dispersion tank and heated to 40°C with stirring. Once all components were uniformly mixed, the stirring rate was increased and deionized water was slowly added dropwise under high-speed shear at 2250 rpm. After the emulsion phase inverted from water-in-oil to oil-in-water, water addition was stopped and high-speed shear was maintained at the current speed for 2 hours. After shearing was completed, the speed was reduced to 800 rpm, and water was added to disperse the mixture for another 0.5 hour until the solids content of the emulsion was adjusted to 75 wt%. This resulted in a stable water-based epoxy emulsion. The relevant properties of the emulsion are shown in Table 3.

[0103] Example 18

[0104] In this example, 3 g of AnquaEM45 emulsifier, 1 g of the hyperbranched polyether epoxy resin prepared in Example 10, and 19 g of bisphenol A epoxy resin were weighed into a dispersion tank, heated to 40°C with stirring, and after all components were uniformly mixed, the stirring rate was increased. Deionized water was slowly added dropwise under high-speed shear at 2500 rpm. After the emulsion phase inverted from water-in-oil to oil-in-water, water addition was stopped and high-speed shear was maintained at the current speed for 2 hours. After shearing was completed, the speed was reduced to 800 rpm, and water was added to disperse the mixture for another 0.5 hour until the solids content of the emulsion was adjusted to 75 wt%. This resulted in a stable water-based epoxy emulsion. The relevant properties of the resulting emulsion are shown in Table 3.

[0105] Comparative Example 2

[0106] A method for preparing a high-solid aqueous epoxy emulsion comprises the following steps:

[0107] 3 g of Anqua EM45 emulsifier, 20 g of bisphenol A epoxy resin, and 1 g of ethylene glycol butyl ether were weighed into a dispersion tank, heated to 40° C. and stirred. The remaining preparation process was the same as in Example 14. The relevant properties of the obtained emulsion are shown in Table 3.

[0108] Comparative Example 3

[0109] 3 g of AnquaEM45 emulsifier, 7 g of the hyperbranched polyether epoxy resin prepared in Example 1, and 13 g of bisphenol A epoxy resin were weighed into a dispersion tank, heated to 40° C. and stirred. The remaining preparation process was the same as in Example 14. The relevant properties of the obtained emulsion are shown in Table 3.

[0110] Comparative Example 4

[0111] Example 3 g of AnquaEM45 emulsifier, 9 g of the hyperbranched polyether epoxy resin prepared in Example 1, and 11 g of bisphenol A epoxy resin were weighed into a dispersion tank, heated to 40° C. and stirred. The remaining preparation process was the same as in Example 14. The relevant properties of the obtained emulsion are shown in Table 3.

[0112] Table 3

[0113]

[0114] Table 3 shows the relevant performance data of the water-based epoxy emulsions prepared in Comparative Examples 2-4 and Examples 14-18. Comparative Example 2 and Examples 14-18 show that using hyperbranched polyether epoxy resin to modify the water-based epoxy emulsion reduces the viscosity of the emulsion system, advances the phase inversion point of the emulsion, reduces the particle size of the emulsion to 200-300 nm, and significantly improves stability. Comparative Examples 3 and 4 show that when the amount of hyperbranched polyether epoxy resin added is too large, the emulsion's centrifugal stability and storage stability decrease, and even demulsification may occur. Therefore, the content of hyperbranched polyether epoxy resin is also crucial when preparing water-based epoxy emulsions.

[0115] Example 19

[0116] A method for preparing a water-based epoxy floor paint comprises the following steps:

[0117] 25g of waterborne epoxy curing agent YNCA701, 65g of deionized water, 8.5g of ethylene glycol butyl ether, 126g of silica powder, 26g of talc, 0.35g of defoamer, and 1g of dispersant were mixed uniformly as component A. 50g of the waterborne epoxy emulsion prepared in Example 14 was weighed as component B. The two were blended to obtain a coatable waterborne epoxy coating. The coating was applied to a non-asbestos fiber cement press board using a scraper and cured at room temperature for 7 days to obtain a test panel. The coating test method was carried out according to the national standard in Table 4.

[0118] Table 4

[0119]

[0120]

[0121] Example 20

[0122] 25g of water-based epoxy curing agent YNCA701, 65g of deionized water, 8.5g of ethylene glycol butyl ether, 126g of silica powder, 26g of talc, 0.35g of defoaming agent, and 1g of dispersant were mixed evenly as component A, and 50g of the water-based epoxy emulsion prepared in Example 15 was weighed as component B. The rest of the preparation process was the same as that in Example 19.

[0123] Example 21

[0124] 25g of water-based epoxy curing agent YNCA701, 65g of deionized water, 8.5g of ethylene glycol butyl ether, 126g of silica powder, 26g of talc, 0.35g of defoaming agent, and 1g of dispersant were mixed evenly as component A, and 50g of the water-based epoxy emulsion prepared in Example 16 was weighed as component B. The rest of the preparation process was the same as in Example 19.

[0125] Example 22

[0126] 27.5 g of water-based epoxy curing agent YNCA701, 65 g of deionized water, 8.5 g of ethylene glycol butyl ether, 126 g of silica powder, 26 g of talc, 0.35 g of defoaming agent, and 1 g of dispersant were mixed evenly as component A, and 50 g of the water-based epoxy emulsion prepared in Example 17 was weighed as component B. The rest of the preparation process was the same as in Example 19.

[0127] Example 23

[0128] 30g of water-based epoxy curing agent YNCA701, 65g of deionized water, 8.5g of ethylene glycol butyl ether, 126g of silica powder, 26g of talc, 0.35g of defoaming agent, and 1g of dispersant were mixed evenly as component A, and 50g of the water-based epoxy emulsion prepared in Example 18 was weighed as component B. The rest of the preparation process was the same as in Example 19.

[0129] Comparative Example 5

[0130] 25g of water-based epoxy curing agent YNCA701, 65g of deionized water, 8.5g of ethylene glycol butyl ether, 126g of silica powder, 26g of talc, 0.35g of defoaming agent, and 1g of dispersant were mixed evenly as component A, and 50g of the water-based epoxy emulsion prepared in Comparative Example 2 was weighed as component B. The rest of the preparation process was the same as that in Example 19.

[0131] Comparative Example 6

[0132] 25g of water-based epoxy curing agent YNCA701, 65g of deionized water, 8.5g of ethylene glycol butyl ether, 126g of silica powder, 26g of talc, 0.35g of defoaming agent, and 1g of dispersant were mixed evenly as component A, and 50g of the water-based epoxy emulsion prepared in Comparative Example 3 was weighed as component B. The rest of the preparation process was the same as that in Example 19.

[0133] The physical and mechanical properties and media resistance of the coatings prepared in Comparative Examples 5 and 6 and Examples 19 to 23 are shown in Tables 5 and 6. It can be seen that the toughness of the coatings in Examples 19 to 23 is significantly improved compared to that in Comparative Example 5, and the Shore hardness decreases slightly, but is still greater than 80D, meeting national standards. In addition, the alkali resistance, acid resistance, oil resistance, water resistance, and salt water resistance of the coatings are also significantly improved compared to Comparative Example 5. However, due to the decrease in emulsion stability, the relevant properties of Comparative Example 6 are affected. Therefore, it can be inferred that the performance of epoxy floor coatings prepared with an appropriate amount of hyperbranched polyether epoxy resin modified emulsion will be significantly improved.

[0134] Table 5

[0135]

[0136] Table 6

[0137]

[0138] Note: The unit of chemical resistance of the coating is hours.

[0139] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A high solid aqueous epoxy emulsion, characterized in that: By weight, it is made of the following components: The molecular weight of the hyperbranched polyether epoxy resin is 2000-2800 g / mol, the epoxy value is 0.15-0.26 mol / 100 g, and the branching degree is 0.4-0.

52.

2. The high solid aqueous epoxy emulsion according to claim 1, characterized in that: The water-based epoxy emulsifier is one or more of AnquaEM45 emulsifier, Solvay-0092 emulsifier, and Naisol emulsifier; the bisphenol A type epoxy resin is one or more of E20 type epoxy resin, E44 type epoxy resin, and E51 type epoxy resin.

3. The high solid aqueous epoxy emulsion according to claim 1, characterized in that: The hyperbranched polyether epoxy resin is prepared by the following method: The polyol, the difunctional epoxy compound, the branched monofunctional epoxy compound and the catalyst are mixed, maintained in a nitrogen atmosphere, and reacted at 140-180° C. for 6-36 hours to obtain a hyperbranched polyether epoxy resin.

4. The high solid aqueous epoxy emulsion according to claim 3, characterized in that: The polyol is one or more of trimethylolpropane, trimethylolethane, and glycerol; the difunctional epoxy compound is one or more of ethylene glycol diglycidyl ether and 1,4-butanediol diglycidyl ether; and the branched monofunctional epoxy compound is tert-butyl carbonate glycidyl ester.

5. The high solid aqueous epoxy emulsion according to claim 3, characterized in that: The molar ratio of the polyol to the difunctional epoxy compound is 1:2-3; the molar ratio of the polyol to the branched monofunctional epoxy compound is 1:0.1-1.

6. The high solid aqueous epoxy emulsion according to claim 3, characterized in that: The catalyst is one or more of tetrabutylammonium bromide and triphenylphosphine; the amount of the catalyst added is 0.5-1.5wt% of the total mass of the reaction monomers.

7. A method for preparing the high solid aqueous epoxy emulsion according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: Mix 10 parts of waterborne epoxy emulsifier, 50-65 parts of bisphenol A epoxy resin, and 3-15 parts of hyperbranched polyether epoxy resin, raise the temperature to 40°C, and stir at a low speed; After mixing evenly, increase the stirring speed, add deionized water under high shearing, and stop adding deionized water after the emulsion undergoes phase reversal from oil-in-water to water-in-oil. Maintain the current speed and high-speed shearing for 2 hours. After the shearing is completed, the rotation speed is reduced to 800 rpm, and deionized water is continuously added for dispersion for 0.5 h, and the solid content of the emulsion is adjusted to 75 wt %, thereby obtaining the high solid content aqueous epoxy emulsion; The amount of deionized water used in the preparation process is 20 to 25 parts.

8. The preparation method according to claim 7, characterized in that: The speed of low-speed stirring is 800 rpm, and the time is 0.5 h; the speed of high-speed shearing is 2000-2500 rpm, and the time is 2.2-2.5 h.

9. Use of the high solid aqueous epoxy emulsion according to any one of claims 1 to 6, characterized in that: High solid content waterborne epoxy emulsion is compounded with waterborne epoxy curing agent to prepare two-component waterborne epoxy floor coating.

10. A two-component waterborne epoxy floor coating containing the high-solid waterborne epoxy emulsion according to any one of claims 1 to 6, characterized in that: The invention comprises component A and component B, wherein component A contains a water-based epoxy resin curing agent, and component B is the high-solid water-based epoxy emulsion.

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