Preparation method and application of high solid content water-based epoxy emulsion

Abstract

The application discloses a high solid content water-based epoxy emulsion which is prepared from the following components in parts by weight: 10 parts of water-based epoxy emulsifier, 50-65 parts of bisphenol A type epoxy resin, 3-15 parts of hyperbranched polyether epoxy resin and 20-25 parts of deionized water. The high solid content water-based epoxy emulsion can greatly reduce the viscosity of the emulsification system due to the hyperbranched structure, thereby preparing a stable emulsion with smaller particle size, the cavities contained in the emulsion can effectively toughen the epoxy coating, the rich epoxy end groups can improve the crosslinking density of the coating, the coating curing is more sufficient, the barrier property of the coating is further improved, and the application value is high in actual use. The solid content of the hyperbranched polyether water-based epoxy emulsion prepared by the application is up to 75% or more, the stability is excellent, and the coating cured after actual use has excellent toughness and medium resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water-based paint technology, in particular to a preparation method of high solid content water-based epoxy emulsion and application thereof. BACKGROUND

[0002] Water-based epoxy paint uses water instead of solvent as a dispersion medium, which is more economical and environmentally friendly, and is one of the popular directions to replace solvent-based epoxy paint. However, the defects of water-based epoxy paint are also obvious: (1) Unlike solvent-based epoxy paint, water-based epoxy paint is a polydispersed system. During the curing process, the curing agent molecules first contact and react with the surface of the epoxy particles, and then gradually diffuse to the inside of the particles for further 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 inside of the particles to fully participate in the curing, and the particles are difficult to fuse together, resulting in micro-pores and defects in the film, and ultimately leading to a decrease in comprehensive performance; (2) The inherent brittleness of water-based epoxy resin leads to poor wear resistance of the paint film, limiting its application in floor coatings. Currently, water-based epoxy resin can be toughened by introducing flexible curing agents, active diluents, inorganic nanoparticles, water-based polyurethane, rubber emulsion, etc.

[0003] In recent years, hyperbranched polymers as a new type of modifier have attracted 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 rich active end groups (hydroxyl, carboxyl, amino, epoxy) of hyperbranched polymers can participate in the crosslinking and curing of the epoxy matrix, increasing the crosslinking density of the cured product. Among them, the epoxy-terminated hyperbranched polymer has the best compatibility with epoxy resin, which can achieve the reinforcement and toughening of the epoxy cured product without causing phase separation. In addition, hyperbranched polymers also have a spherical branched topological structure, which can greatly reduce chain entanglement and bring better processing fluidity to the resin system. However, these studies are all carried out in homogeneous systems, and currently there are still few studies on the modification of water-based epoxy coatings by hyperbranched epoxy resin at home and abroad. Zhang Di, Wang Yuan, etc. have explored this field. They synthesized several hyperbranched polyether epoxy resins by using dihydric phenol and trimethylolpropane triglycidyl ether, and added them to the water-based epoxy system, successfully preparing stable emulsion with low particle size. However, the viscosity of the synthesized hyperbranched epoxy resin is high, which increases the viscosity of the emulsion system, making it difficult to prepare high solid content water-based epoxy emulsion, which limits the application of hyperbranched epoxy resin in the field of water-based epoxy floor coatings. SUMMARY

[0004] To address the aforementioned problems in existing technologies, this invention provides a method for preparing a high-solids-content waterborne epoxy emulsion and its application. Based on the proton transfer polymerization mechanism, this invention synthesizes a hyperbranched polyether epoxy resin in a one-pot process under solvent-free conditions without purification. The obtained resin is then used to modify a waterborne epoxy emulsion, successfully preparing a high-solids-content waterborne epoxy emulsion. This high-solids-content waterborne epoxy emulsion is then compounded with a waterborne epoxy curing agent to prepare a waterborne epoxy floor coating. The coating exhibits excellent toughness, hardness, abrasion resistance, and chemical resistance.

[0005] The technical solution of the present invention is as follows:

[0006] The first objective of this invention is a high-solids-content 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 / 100g, and a branching degree of 0.4-0.52.

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

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

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

[0012] A mixture of polyol, difunctional epoxy compound, branched monofunctional epoxy compound and catalyst is prepared and reacted at 140–180°C for 6–36 hours under a nitrogen atmosphere to obtain 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 glycidyl tert-carbonate.

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

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

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

[0019] In one embodiment of the present application, the catalyst is added in an amount of 0.5-1.5wt% of the total mass of the reaction monomers.

[0020] The total mass of the reaction monomers is the total mass of the polyol, the double functional epoxy compound and the branched single functional epoxy compound.

[0021] In one embodiment of the present application, no solvent is involved in the reaction process, and the reaction product can be directly used for subsequent preparation of the waterborne epoxy emulsion after the reaction is completed.

[0022] In one embodiment of the present application, the synthesis route of the hyperbranched polyether epoxy resin is as follows:

[0023]

[0024] A second object of the present application is to provide a preparation method of the high solid content waterborne epoxy emulsion as described above, comprising the following steps:

[0025] 10 parts of a waterborne epoxy emulsifier, 50-65 parts of a bisphenol A type epoxy resin and 3-15 parts of a hyperbranched polyether epoxy resin are mixed, and the temperature is raised to 40°C and stirred at a low speed;

[0026] After the mixture is uniformly mixed, the stirring speed is increased, and deionized water is added dropwise under high speed shearing. After the phase inversion of the emulsion from water-in-oil to oil-in-water, the addition of deionized water is stopped, and the current speed is maintained for high speed shearing for 2h;

[0027] After the shearing is completed, the speed is reduced to 800rpm, and the dispersion of deionized water is continued for 0.5h. The solid content of the emulsion is adjusted to 75wt%, and the high solid content waterborne epoxy emulsion is obtained.

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

[0029] In one embodiment of the present application, the stirring speed at a low speed is 800rpm, and the time is 0.5h.

[0030] In one embodiment of the present application, the high-speed shearing rotation speed is 2000-2500 rpm, and the time is 2.2-2.5 h; wherein the time for reaching the phase inversion point is 10-30 min, and the time for uniform dispersion after stopping water addition is 2 h.

[0031] In one embodiment of the present application, the epoxy emulsion is prepared by using the phase inversion method, specifically, the epoxy resin is uniformly mixed with the emulsifier, then deionized water is slowly added to the system under a certain shearing rate, at this time, the water droplets are dispersed in the epoxy resin under the action of shearing force and emulsifier to form a water-in-oil system (W / O), when the water content in the system gradually increases to reach the critical point (phase inversion point), the water will change from the dispersed phase to the continuous phase to form an oil-in-water system (O / W). During the period, the viscosity change of the system is observed, when the viscosity of the system suddenly decreases, a drop of the emulsion is taken to the deionized water, if the emulsion can be quickly dispersed in the water phase, it indicates that the system has changed from W / O state to O / W state, that is, the emulsion has reached the phase inversion point.

[0032] In one embodiment of the present application, the rotation speed of 800 rpm in the premixing stage is to uniformly disperse the epoxy resin and the emulsifier, and the rotation speed is gradually increased to 2000-2500 rpm in the water adding stage to ensure that the water droplets are uniformly dispersed and form an emulsion with small particle size, and finally the rotation 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 application is to provide an application of the above high solid content waterborne epoxy emulsion, the high solid content waterborne epoxy emulsion is compounded with a waterborne epoxy curing agent to prepare a two-component waterborne epoxy floor coating.

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

[0035] In one embodiment of the present application, the component A comprises a waterborne epoxy curing agent, ethylene glycol butyl ether, deionized water, silicon powder, and talc powder.

[0036] In one embodiment of the present application, the component A comprises 10-12 parts of a waterborne epoxy curing agent, 3 parts of ethylene glycol butyl ether, 26 parts of deionized water, 50 parts of silicon powder, and 11 parts of talc powder.

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

[0038] In one embodiment of the present application, the waterborne epoxy floor coating further comprises an additive, such as one or more of a defoaming agent and a dispersing agent.

[0039] The beneficial technical effects of the present application are as follows:

[0040] The hyperbranched polyether epoxy resin is prepared by the A2+B3 method, the synthesis process does not involve a solvent, the steps are simple, and raw materials are easy to obtain, and has great commercialization potential.

[0041] The flexible skeleton and branched topological structure of the hyperbranched polyether epoxy resin endow it with the characteristics of low viscosity, which can effectively reduce the viscosity of the emulsion system, thereby realizing the preparation of a high solid content waterborne epoxy emulsion; the rich epoxy end groups endow it with good compatibility with bisphenol A type epoxy resins, and as a modifier, it can participate in curing to improve the crosslinking density of the cured product, making the coating more dense, thereby improving the barrier performance of the coating to corrosive media; the flexible chain segments and intramolecular cavities can absorb impact energy, improving the toughness and wear resistance of the cured product; the fatty chain segments in the tertiary glycidyl carbonate can improve the hydrophobicity of the coating and improve the chemical medium resistance of the coating. BRIEF DESCRIPTION OF DRAWINGS

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

[0043] Figure 2 The nuclear magnetic resonance spectrum of the hyperbranched polyether epoxy resin prepared in Example 1 is shown in the figure;

[0044] Figure 3 The GPC elution curve of the hyperbranched polyether epoxy resin prepared in Examples 1, 6-7 is shown in the figure. DETAILED DESCRIPTION

[0045] The present application will be specifically described below in combination with the drawings and examples.

[0046] The synthetic raw materials involved in the present application can be obtained from commercial channels if not otherwise specified, and Table 1 shows the raw materials involved in the implementation of the method.

[0047] Table 1

[0048] Experimental materials Specifications Manufacturers Trimethylolpropane 98％ Shanghai Maikelin Biochemical Technology Co., Ltd. Glycerol 99％ Shanghai Maikelin Biochemical Technology Co., Ltd. Trihydroxymethylethane 97％ Shanghai Aladdin Biochemical Technology Co., Ltd. Ethylene glycol diglycidyl ether Analytical pure Shanghai Maikelin Biochemical Technology Co., Ltd. 1,4-Butanediol diglycidyl ether 99％ Shanghai Maikelin Biochemical Technology Co., Ltd. Glycidyl tert-carbonate 99％ Shanghai Maikelin Biochemical Technology Co., Ltd. Tetrabutylammonium bromide 99％ Shanghai Aladdin Biochemical Technology Co., Ltd. Triphenylphosphine 99％ Shanghai Aladdin Biochemical Technology Co., Ltd. Anqua EM45 emulsifier Industrial grade Provided by Yangnong Jinhu Chemical Co., Ltd. E51 type bisphenol A type epoxy resin Industrial grade Yangnong Jinhu Chemical Co., Ltd. Ethylene glycol butyl ether Analytical pure Shanghai Maikelin Biochemical Technology Co., Ltd. Water-based epoxy curing agent YNCA701 Industrial grade Yangnong Jinhu Chemical Co., Ltd. Silica powder Industrial grade Yangnong Jinhu Chemical Co., Ltd. Talc powder Industrial grade Yangnong Jinhu Chemical Co., Ltd. Defoamer (BYK-028) Industrial grade Bayer (China) Investment Co., Ltd. Dispersant (BYK-190) Industrial grade Bayer (China) Investment Co., Ltd.

[0049] Examples 1-13 are the preparation of hyperbranched polyether epoxy resins. Examples 14-18 are the preparation of waterborne epoxy emulsions. Examples 19-23 are the preparation method of waterborne epoxy floor paint.

[0050] Example 1

[0051] A preparation method of a hyperbranched polyether epoxy resin, comprising the following steps:

[0052] Take 5.36 g of trimethylolpropane, 17.42 g of ethylene glycol diglycidyl ether, 4.57 g of glycidyl tert-butyl carbonate and 0.27 g of tetrabutylammonium bromide into a reactor, and react under the protection of nitrogen atmosphere at 160℃ for 12 h. After the reaction is completed, a light yellow transparent liquid is obtained, which is a hyperbranched polyether epoxy resin, and the physicochemical properties thereof 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 is changed from 12 h to 24 h, and other conditions are as shown in Example 1. The physicochemical 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 is changed from 12 h to 36 h, and other conditions are as shown in Example 1. The physicochemical 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 is changed from 160℃ to 140℃, and the reaction time is extended from 12 h to 24 h, and other conditions are as shown in Example 1. The physicochemical 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 is changed from 160℃ to 180℃, and the reaction time is shortened from 12 h to 6 h, and other conditions are as shown in Example 1. The physicochemical 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] This example is based on Example 1, replacing trimethylolpropane with glycerol, changing its amount to 3.68 g, and reducing the amount of tetrabutylammonium bromide to 0.26 g, and changing other conditions as shown in Example 1. The physical and chemical properties of the hyperbranched polyether epoxy resin obtained are shown in Table 2.

[0068] Example 7

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

[0070] This example is based on Example 1, replacing trimethylolpropane with trimethyloloethane, changing its amount to 4.81 g, and changing other conditions as shown in Example 1. The physical and chemical properties of the hyperbranched polyether epoxy resin obtained are shown in Table 2.

[0071] Example 8

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

[0073] This example is based on Example 1, replacing ethylene glycol diglycidyl ether with 1,4-butanediol diglycidyl ether, changing its amount to 20.22 g, and increasing the amount of tetrabutylammonium bromide to 0.30 g, and changing other conditions as shown in Example 1. The physical and chemical properties of the hyperbranched polyether epoxy resin obtained are shown in Table 2.

[0074] Example 9

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

[0076] Take 5.36 g of trimethylolpropane, 20.88 g of ethylene glycol diglycidyl ether, 3.04 g of glycidyl ester of versatic acid, and 0.29 g of tetrabutylammonium bromide, and place them in a reactor, and change other conditions as shown in Example 1. The physical and chemical properties of the hyperbranched polyether epoxy resin obtained are shown in Table 2.

[0077] Example 10

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

[0079] Take 5.36 g of trimethylolpropane, 20.88 g of ethylene glycol diglycidyl ether, 0.91 g of glycidyl ester of versatic acid, and 0.27 g of tetrabutylammonium bromide, and place them in a reactor, and change other conditions as shown in Example 1. The physical and chemical properties of the hyperbranched polyether epoxy resin obtained are shown in Table 2.

[0080] Example 11

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

[0082] Take 5.36 g of trimethylolpropane, 13.92 g of ethylene glycol diglycidyl ether, 4.57 g of glycidyl ester of versatic acid and 0.12 g of tetrabutyl ammonium bromide into a reactor, and other conditions are as shown in Example 1, to obtain the hyperbranched polyether epoxy resin, and its physicochemical properties are shown in Table 2.

[0083] Example 12

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

[0085] Take 5.36 g of trimethylolpropane, 17.42 g of ethylene glycol diglycidyl ether, 10.14 g of glycidyl ester of versatic acid and 0.49 g of tetrabutyl ammonium bromide into a reactor, and other conditions are as shown in Example 1, to obtain the hyperbranched polyether epoxy resin, and its physicochemical properties are shown in Table 2.

[0086] Example 13

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

[0088] Take 5.36 g of trimethylolpropane, 17.42 g of ethylene glycol diglycidyl ether, 4.57 g of glycidyl ester of versatic acid and 0.27 g of triphenylphosphine into a reactor, and other conditions are as shown in Example 1, to obtain the hyperbranched polyether epoxy resin, and its physicochemical properties are shown in Table 2.

[0089] Comparative Example 1

[0090] Take 5.36 g of trimethylolpropane, 17.42 g of ethylene glycol diglycidyl ether and 0.23 g of tetrabutyl ammonium bromide into a reactor, and react under the protection of nitrogen atmosphere at 160℃ for 12 h. After the reaction is completed, a light yellow transparent liquid is obtained, which is the hyperbranched polyether epoxy resin, and its physicochemical properties are shown in Table 2.

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

[0092] The physicochemical data of the hyperbranched polyether epoxy resins prepared in Examples 1-13 are shown in Table 2. The number average molecular weight of the hyperbranched polyether epoxy resin is between 2000-2800, and has a moderate molecular weight; the viscosity is basically around 2 Pa·s, and it is found by comparison with Comparative Example 1 that the addition of glycidyl ester of versatic acid can further reduce the viscosity of the resin; the degree of branching of all examples is above 0.4, which meets the structural characteristics of the hyperbranched polyether epoxy resin. The hyperbranched polyether epoxy resin has good compatibility with bisphenol A type epoxy resin, and the addition amount of the hyperbranched epoxy resin can be adjusted according to the application in waterborne epoxy coating. Figure 1 is the infrared spectrum of Example 1, showing that the peak at 3200 cm -1 -3600 cm-1 stretching vibration peak of hydroxyl group, 2960 cm -1 stretching vibration peak of methyl and methylene group, 910 cm -1 stretching vibration peak of hydroxyl group, 2960 cm -1 stretching vibration peak of hydroxyl group, 2960 cm Figure 2 is the nuclear magnetic spectrum of Example 1. There are a large number of fatty chain segments, ether bonds and secondary hydroxyl groups in the structure of Example 1, so there are strong characteristic peaks at 3.20-4.20 ppm, the signal peak at 0.75 ppm corresponds to the methyl group, and the two single peaks at 2.55-2.90 ppm correspond to the two proton peaks of the methylene group in the epoxy group. In addition, the hyperbranched polymer is composed of branched units (D), linear units (L) and terminal units (T). Since the chemical shift of the proton on the methylene group adjacent to the methyl group on trimethylolpropane will change significantly in these three different chemical environments, the branching degree of Example 1 can be calculated using the branching degree formula DB = (D+T) / (D+T+L) to calculate the branching degree of Example 1, which is 0.45. Figure 3 is the GPC flow curve of Example 1, Example 6 and Example 7. It can be seen that the relative molecular mass of the sample is located at 2300-2400 g / mol.

[0093] Table 2

[0094]

[0095] Example 14

[0096] In this example, 3 g of AnquaEM45 emulsifier, 1 g of hyperbranched polyether epoxy resin prepared in Example 1 and 19 g of bisphenol A type epoxy resin were weighed into a dispersion tank and stirred at 40°C. After all the components were uniformly mixed, the stirring speed was increased, and deionized water was slowly added under high shear at 200 rpm. After the emulsion phase inversion from water-in-oil to oil-in-water, the water addition was stopped, and the current speed was maintained for high shear for 2 h. After shearing, the speed was reduced to 800 rpm, and the water dispersion was continued for 0.5 h. The solid content of the emulsion was adjusted to 75 wt%, and a stable waterborne epoxy emulsion was obtained. The related properties of the emulsion are shown in Table 3.

[0097] Example 15

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

[0099] Example 16

[0100] This example takes 3g AnquaEM45 emulsifier, 4g hyperbranched polyether epoxy resin prepared in Example 1, 16g bisphenol A type epoxy resin into a dispersion tank, and the rest of the preparation process is the same as Example 14. The related properties of the obtained emulsion are shown in Table 3.

[0101] Example 17

[0102] This example takes 3g AnquaEM45 emulsifier, 1g hyperbranched polyether epoxy resin prepared in Example 9, 19g bisphenol A type epoxy resin into a dispersion tank, and the rest of the preparation process is the same as Example 14. The related properties of the obtained emulsion are shown in Table 3.

[0103] Example 18

[0104] This example takes 3g AnquaEM45 emulsifier, 1g hyperbranched polyether epoxy resin prepared in Example 10, 19g bisphenol A type epoxy resin into a dispersion tank, and the rest of the preparation process is the same as Example 14. The related properties of the obtained emulsion are shown in Table 3.

[0105] Comparative Example 2

[0106] A method for preparing a high solid content waterborne epoxy emulsion, comprising the following steps:

[0107] This example takes 3g AnquaEM45 emulsifier, 20g bisphenol A type epoxy resin, 1g ethylene glycol butyl ether into a dispersion tank, and the rest of the preparation process is the same as Example 14. The related properties of the obtained emulsion are shown in Table 3.

[0108] Comparative Example 3

[0109] This example takes 3g AnquaEM45 emulsifier, 7g hyperbranched polyether epoxy resin prepared in Example 1, 13g bisphenol A type epoxy resin into a dispersion tank, and the rest of the preparation process is the same as Example 14. The related properties of the obtained emulsion are shown in Table 3.

[0110] Comparative Example 4

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

[0112] Table 3

[0113]

[0114] Table 3 shows the relevant performance data of the waterborne epoxy emulsions prepared in Comparative Examples 2-4 and Examples 14-18. As can be seen from Comparative Examples 2 and Examples 14-18, modifying the waterborne epoxy emulsion with hyperbranched polyether epoxy resin reduces the viscosity of the emulsion system, advances the phase inflection point of the emulsion, reduces the particle size of the emulsion to 200-300 nm, and significantly improves stability. However, as can be seen from Comparative Examples 3 and 4, when the amount of hyperbranched polyether epoxy resin added is too large, the centrifugal stability and storage stability of the emulsion decrease, and even demulsification may occur. Therefore, the content of hyperbranched polyether epoxy resin is also crucial when preparing waterborne epoxy emulsions.

[0115] Example 19

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

[0117] Component A was prepared by uniformly mixing 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 powder, 0.35g of defoamer, and 1g of dispersant. Component B was prepared by weighing 50g of the waterborne epoxy emulsion prepared in Example 14. The two components were then blended to obtain a coatable waterborne epoxy coating. The coating was applied to an asbestos-free fiber cement pressure board using a scraper and cured at room temperature for 7 days to obtain a sample for testing. The coating testing method was conducted according to the national standards in Table 4.

[0118] Table 4

[0119]

[0120]

[0121] Example 20

[0122] Mix 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 evenly to form component A. Then weigh 50g of the waterborne epoxy emulsion prepared in Example 15 to form component B. The rest of the preparation process is the same as in Example 19.

[0123] Example 21

[0124] After mixing 25 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 powder, 0.35 g of defoaming agent, and 1 g of dispersant uniformly, it was used as component A. Then, 50 g of the water-based epoxy emulsion prepared in Example 16 was weighed as component B, and the remaining preparation process was the same as that of Example 19.

[0125] Example 22

[0126] After mixing 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 powder, 0.35 g of defoaming agent, and 1 g of dispersant uniformly, it was used as component A. Then, 50 g of the water-based epoxy emulsion prepared in Example 17 was weighed as component B, and the remaining preparation process was the same as that of Example 19.

[0127] Example 23

[0128] After mixing 30 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 powder, 0.35 g of defoaming agent, and 1 g of dispersant uniformly, it was used as component A. Then, 50 g of the water-based epoxy emulsion prepared in Example 18 was weighed as component B, and the remaining preparation process was the same as that of Example 19.

[0129] Comparative Example 5

[0130] After mixing 25 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 powder, 0.35 g of defoaming agent, and 1 g of dispersant uniformly, it was used as component A. Then, 50 g of the water-based epoxy emulsion prepared in Comparative Example 2 was weighed as component B, and the remaining preparation process was the same as that of Example 19.

[0131] Comparative Example 6

[0132] After mixing 25 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 powder, 0.35 g of defoaming agent, and 1 g of dispersant uniformly, it was used as component A. Then, 50 g of the water-based epoxy emulsion prepared in Comparative Example 3 was weighed as component B, and the remaining preparation process was the same as that of Example 19.

[0133] The physical and mechanical properties and the medium resistance of the coating prepared in Comparative Examples 5 and 6 and Example 19-23 are shown in Table 5 and Table 6. It can be seen that the toughness of the coating of Example 19-23 is obviously improved compared with Comparative Example 5, the Shore hardness slightly decreases, but is greater than 80D, meeting the national standard, and the alkali resistance, acid resistance, oil resistance, water resistance and salt water resistance of the coating are also obviously improved compared with Comparative Example 5. Due to the decrease in the stability of the emulsion, the related properties of Comparative Example 6 are affected, thus it can be inferred that the performance of the epoxy floor coating prepared by modifying the emulsion with the appropriate hyperbranched polyether epoxy resin is greatly improved.

[0134] Table 5

[0135]

[0136] Table 6

[0137]

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

[0139] The above provided examples are not intended to limit the scope covered by the present application, and the described steps are not intended to limit the execution order. The obvious improvements of the present application made by the person skilled in the art in combination with the existing common knowledge also fall within the protection scope defined by the claims of the present application.

Claims

1. A high-solids-content water-based epoxy emulsion, characterized in that, It is made from the following components in parts by weight: 10 parts of water-based epoxy emulsifier 50-65 parts of bisphenol A type epoxy resin Hyperbranched polyether epoxy resin 3 to 15 parts 20-25 parts deionized water; The hyperbranched polyether epoxy resin has a molecular weight of 2000-2800 g / mol, an epoxy value of 0.15-0.26 mol / 100g, and a branching degree of 0.4-0.

52. The hyperbranched polyether epoxy resin is prepared by the following method: Polyol, difunctional epoxy compound, branched monofunctional epoxy compound and catalyst are mixed and reacted at 140~180 ºC for 6~36 h under nitrogen atmosphere to obtain hyperbranched polyether epoxy resin. 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 glycidyl tert-carbonate.

2. The high-solids-content water-based epoxy emulsion according to claim 1, characterized in that, The waterborne epoxy emulsifier is one or more of AnquaEM45 emulsifier and Solvay-0092 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-solids-content water-based epoxy emulsion according to claim 1, characterized in that, The molar ratio of the polyol to the difunctional epoxy compound is 1:2 to 3; the molar ratio of the polyol to the branched monofunctional epoxy compound is 1:0.1 to 1.

4. The high-solids-content water-based epoxy emulsion according to claim 1, characterized in that, The catalyst is one or more of tetrabutylammonium bromide and triphenylphosphine; the amount of catalyst added is 0.5 to 1.5 wt% of the total mass of the reaction monomers.

5. A method for preparing the high-solids-content water-based epoxy emulsion according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: Mix 10 parts of water-based epoxy emulsifier, 50-65 parts of bisphenol A type epoxy resin, and 3-15 parts of hyperbranched polyether epoxy resin, and heat to 40 ºC while stirring at low speed; the stirring speed is 800 rpm. After mixing evenly, increase the stirring speed and add deionized water dropwise under high-speed shearing. After the emulsion undergoes an inversion, changing from water-in-oil to oil-in-water, stop adding deionized water and maintain the current high-speed shearing speed for 2 hours. The high-speed shearing speed is 2000~2500 rpm. After shearing, reduce the rotation speed to 800 rpm, continue to add deionized water for 0.5 h to disperse, and adjust the emulsion solid content to 75 wt% to obtain the high solid content water-based epoxy emulsion. The amount of deionized water used in the preparation process is 20-25 parts.

6. The preparation method according to claim 5, characterized in that, The low-speed stirring time is 0.5 h; the high-speed shearing time is 2.2 ~ 2.5 h.

7. The application of the high-solids-content water-based epoxy emulsion according to any one of claims 1 to 4, characterized in that, A high-solids water-based epoxy emulsion is compounded with a water-based epoxy curing agent to prepare a two-component water-based epoxy floor coating.

8. A two-component waterborne epoxy floor coating containing the high-solids waterborne epoxy emulsion according to any one of claims 1 to 4, characterized in that, It includes component A and component B, where component A contains an aqueous epoxy resin curing agent and component B is the high-solids-content aqueous epoxy emulsion.

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