Disclosure of Invention
In order to solve the problems, the application provides an epoxy resin-acrylic resin-based waterborne alkyd resin, which utilizes a multi-branched s-triazine derivative to modify a copolymer of acrylic acid and maleic anhydride, then utilizes the prepolymer to modify a double-part A epoxy resin, and utilizes carboxyl on an acrylic prepolymer to perform esterification reaction with hydroxyl in a bisphenol A epoxy resin so as to combine the bisphenol A epoxy resin with the acrylic prepolymer. And (3) participating the combination into the synthesis of the alkyd resin to finally prepare the alkyd resin. The nitrogen-containing compound is grafted in the acrylic resin to improve the high-temperature resistance of the coating; the polybasic compound is grafted in the acrylic acid to improve the molecular weight of the resin in the finish paint, so that the water resistance of the initial paint is good. The alkyd resin provided by the application is simple in preparation process and has a good market popularization prospect.
In order to achieve the purpose, the technical scheme adopted by the application is as follows:
the waterborne alkyd resin based on the epoxy resin-acrylic resin is prepared from the following components in parts by weight:
50-100 parts of polyol, 40-90 parts of polybasic acid, 10-15 parts of water-based monomer, 5-7.5 parts of bisphenol A epoxy resin, 40-60 parts of acrylic prepolymer, 10-20 parts of cosolvent and 3-6 parts of neutralizer;
the acrylic prepolymer is polymerized by dialdehyde compound and trimethyl s-triazine, and then further polymerized by methyl methacrylate and maleic anhydride.
Said trimethyl-s-triazine is synthesized according to the methods described in document H.G.Elias, E.Greth, Die Makromolekulare Chemie,1969,123, 203;
the preparation method of the acrylic prepolymer comprises the following steps:
1) the dialdehyde compound and trimethyl s-triazine are mixed according to a ratio of 3-5: 1 equivalent weight is dissolved in xylene, the reaction is stopped after Lewis base reacts for 8 to 12 hours at the temperature of between 60 and 100 ℃, and the Lewis base is removed by filtration;
2) adding methyl methacrylate and maleic anhydride into the filtrate system obtained in the step 1), introducing nitrogen for 20-30min, adding an initiator, reacting at 170-180 ℃ for 2-5h, and fractionating xylene in the reaction process to obtain an acrylic prepolymer;
the Lewis base is selected from potassium hydroxide and sodium hydroxide; the molar ratio of the Lewis base to the trimethyl s-triazine is 2: 3;
the initiator is BPO, and the dosage of the initiator accounts for 0.1-0.015 percent of the total mass of the system;
the dialdehyde compound has a general formula of OHC-R-CHO, wherein R is C2-C6 straight-chain alkyl;
the molar ratio of the methyl methacrylate to the trimethyl s-triazine is 12-20: 1;
the molar ratio of the methyl methacrylate to the maleic anhydride is 1-1.2: 1;
when a dialdehyde compound reacts with trimethyl s-triazine, the methyl group reacts with the aldehyde group to form C ═ C, and trimethyl s-triazine
The upper 3 methyl groups are uniformly dispersed, and three branched chains are connected with alkyl chains to form a multi-branched structure; and then, when methyl methacrylate and maleic anhydride are dripped into the system, the double bond of acrylic acid or anhydride and the double bond formed by the aldehyde group and the methyl carry out free radical polymerization to obtain the acrylic prepolymer. The acrylic prepolymer is reacted with bisphenol a epoxy resin and the carboxyl groups in the prepolymer are reacted with the epoxy groups in the epoxy resin to combine the epoxy resin and the acrylic prepolymer. Therefore, acrylic prepolymer with larger molecular weight is grafted on the epoxy resin chain, so that the polarity of the epoxy resin is improved. When the modified epoxy resin participates in the alkyd reaction, a branched chain structure with larger molecular weight is introduced on the long chain esterified by the alkyd, so that the polarity of the macromolecule is improved, the cohesive force of the macromolecule is reduced, the wetting property of the macromolecule is improved, the van der Waals force between the resin and the steel surface is improved, and the adhesive force on the steel structure surface is increased.
On the other hand, nitrogen atoms on the triazine ring have lone-pair electrons and can form covalent bonds with metal ions on the surface of steel
The bond increases the adhesive force of the coating to a certain extent.
The preparation method of the epoxy resin-acrylic resin double-modified water-based alkyd resin paint specifically comprises the following steps:
1) preheating acrylic prepolymer to 70-80 ℃, and adding bisphenol A epoxy resin and a catalyst (tetraethylammonium bromide)
0.01-1wt percent of polymerization inhibitor and 0.01-1wt percent of polymerization inhibitor (2, 6-di-tert-butyl-p-cresol), adding into acrylic prepolymer, heating
Keeping the temperature to 80-110 ℃, reacting until the acid value is lower than 6mgKOH/g, and stopping the reaction to obtain acrylic acid modified bisphenol A epoxy resin;
2) taking polybasic acid, polyalcohol and water-based monomer according to a given proportion, adding the mixture into a reaction kettle, and reacting at the temperature of 180-
The reaction is stopped until the acid value is 3-10mg KOH/g;
3) adding the product obtained in the step 1) into the step 2), adding a cosolvent, and reacting for 5-6h at the temperature of 50-80 ℃;
4) cooling to 50 ℃, adding a neutralizing agent, reacting for 30-40min under heat preservation, adding deionized water, adjusting the solid content to 80-
And 95 percent, discharging.
The polyalcohol is selected from a complex of pentaerythritol and sorbitol, and the equivalent ratio of hydroxyl content of the polyalcohol to the sorbitol is 1: 1;
the polybasic acid is selected from soybean oil fatty acid, the acid value is 198-204mgKOH/g, and the iodine value is 120-
125mgKOH/g;
The bisphenol A epoxy resin is E20 bisphenol A epoxy resin;
the water-based monomer is selected from trimellitic anhydride;
the cosolvent is selected from isopropanol;
the neutralizing agent is selected from N, N-dimethylethanolamine;
the technology introduces the acrylic prepolymer, and improves the dispersion performance of the coating through hyperbranched modification; the introduction of trimethyl s-triazine improves the content of nitrogen element, and the corrosion resistance is further improved; in addition, the hyperbranched acrylic prepolymer is introduced, so that the molecular weight distribution of the polymer is improved, and the water resistance of the initial paint is effectively improved; dialdehyde compounds are used in the prepolymer, and alkyl chains are introduced, so that the polymer is stable and is not easy to decompose under the conditions of illumination and the like.
Detailed Description
Example 1
The waterborne alkyd resin based on the epoxy resin-acrylic resin is prepared from the following components in parts by weight:
50-100 parts of polyol, 40-90 parts of polybasic acid, 10-15 parts of water-based monomer, 5-7.5 parts of bisphenol A epoxy resin,
40-60 parts of acrylic prepolymer, 10-20 parts of cosolvent and 3-6 parts of neutralizer;
the acrylic prepolymer is polymerized by dialdehyde compound and trimethyl s-triazine and further polymerized with methyl propyl
Methyl enoate, maleic anhydride polymerized prepolymer.
The preparation method of the acrylic prepolymer comprises the following steps:
1) dialdehyde compound and trimethyl s-triazine are mixed according to a ratio of 3-5: 1 equivalent weight is dissolved in xylene, the reaction is stopped after Lewis base reacts for 8 to 12 hours at the temperature of between 60 and 100 ℃, and the Lewis base is removed by filtration;
2) adding methyl methacrylate and maleic anhydride into the filtrate system in the step 1), introducing nitrogen for 20-30min, adding an initiator, reacting at 170-180 ℃ for 2-5h, and distilling xylene in the reaction process to obtain an acrylic prepolymer;
the Lewis base is selected from potassium hydroxide and sodium hydroxide; the molar ratio of the Lewis base to the trimethyl s-triazine is 2: 3;
the initiator is BPO, and the dosage of the initiator accounts for 0.1-0.015 percent of the total mass of the system;
the general formula of the dialdehyde compound is OHC- (CH 2) 2-CHO, and n is selected from 2, 3, 4, 5 and 6;
the molar ratio of the methyl methacrylate to the trimethyl s-triazine is 12-20: 1;
the molar ratio of the methyl methacrylate to the maleic anhydride is 1-1.2: 1;
the preparation method of the epoxy resin-acrylic resin double-modified waterborne alkyd resin coating specifically comprises the following steps:
1) preheating acrylic prepolymer to 70-80 ℃, and then adding E20 bisphenol A epoxy resin and a catalyst (tetraethyl bromide)
0.01 to 1 weight percent of ammonium, 0.01 to 1 weight percent of polymerization inhibitor (2, 6-ditert-butyl-p-cresol/0.01 to 1 weight percent), adding into acrylic prepolymer and raising the volume
Heating to 80-110 ℃, preserving the temperature, reacting until the acid value is lower than 6mgKOH/g, and stopping the reaction to obtain acrylic acid modified bisphenol A epoxy resin;
2) taking polybasic acid, polyalcohol and trimellitic anhydride according to a given proportion, adding into a reaction kettle at the temperature of 180-
Stopping the reaction until the acid value is 3-10mg KOH/g;
3) adding the product obtained in the step 1) into the step 2), adding a cosolvent, and reacting for 5-6h at the temperature of 50-80 ℃;
4) cooling to 50 ℃, adding a neutralizing agent, reacting for 30-40min under heat preservation, adding deionized water, adjusting the solid content to 80-
And 95 percent, discharging.
The polyalcohol is selected from a complex of pentaerythritol and sorbitol, and the equivalent ratio of hydroxyl content of the polyalcohol to the sorbitol is 1: 1;
the polybasic acid is selected from soybean oil fatty acid, the acid value is 198-204mgKOH/g, and the iodine value is 120-125 mgKOH/g;
example 2
The waterborne alkyd resin based on the epoxy resin-acrylic resin is prepared from the following components in parts by weight:
50 parts of polyol, 40 parts of polybasic acid, 10 parts of water-based monomer, 5 parts of bisphenol A epoxy resin and 40 parts of acrylic prepolymer
10 parts of cosolvent and 3 parts of neutralizer;
the acrylic prepolymer is polymerized by dialdehyde compound and trimethyl s-triazine and further polymerized with methyl propyl
Methyl enoate, maleic anhydride polymerized prepolymer.
The preparation method of the acrylic prepolymer comprises the following steps:
1) dialdehyde compound and trimethyl s-triazine are mixed according to a ratio of 3: 1 equivalent, dissolved in xylene, at 60 ℃ in Lewis acid
Stopping the reaction after the alkali reacts for 8 hours, and filtering to remove the Lewis base;
2) adding methyl methacrylate and maleic anhydride into the filtrate system obtained in the step 1), introducing nitrogen for 20min, adding an initiator, reacting at 170 ℃ for 2-5h, and fractionating xylene in the reaction process to obtain an acrylic prepolymer;
the Lewis base is selected from potassium hydroxide and sodium hydroxide; the molar ratio of the Lewis base to the trimethyl s-triazine is 2: 3;
the initiator is BPO, and the dosage of the initiator accounts for 0.1 to 0.015 percent of the mass of the whole system;
the general formula of the dialdehyde compound is OHC- (CH 2) 2-CHO;
the molar ratio of the methyl methacrylate to the trimethyl s-triazine is 12: 1;
the molar ratio of the methyl methacrylate to the maleic anhydride is 1: 1;
the preparation method of the epoxy resin-acrylic resin double-modified waterborne alkyd resin coating specifically comprises the following steps:
1) preheating acrylic prepolymer to 70 ℃, and adding E20 bisphenol A epoxy resin and a catalyst (tetraethylammonium bromide)
0.01-1wt percent of polymerization inhibitor and 0.01-1wt percent of polymerization inhibitor (2, 6-di-tert-butyl-p-cresol), adding into acrylic prepolymer, heating
Keeping the temperature to 80-110 ℃, reacting until the acid value is lower than 6mgKOH/g, and stopping the reaction to obtain acrylic acid modified bisphenol A epoxy resin;
2) taking polybasic acid, polyalcohol and trimellitic anhydride according to a given proportion, adding into a reaction kettle, and reacting at 200 DEG C
Stopping the reaction until the acid value is 6mg KOH/g;
3) adding the product obtained in the step 1) into the step 2), adding a cosolvent, and reacting for 5-6h at the temperature of 50-80 ℃;
4) cooling to 50 deg.C, adding neutralizer, reacting for 30-40min, adding deionized water, and adjusting solid content
And 80%, discharging.
The polyalcohol is selected from a complex of pentaerythritol and sorbitol, and the equivalent ratio of hydroxyl content of the polyalcohol to the hydroxyl content of the sorbitol is 1: 1;
the polybasic acid is selected from soybean oil fatty acid, the acid value is 198-204mgKOH/g, and the iodine value is 120-
125mgKOH/g;
Example 3
The waterborne alkyd resin based on the epoxy resin-acrylic resin is prepared from the following components in parts by weight:
100 parts of polyol, 90 parts of polybasic acid, 15 parts of water-based monomer, 5-7.5 parts of bisphenol A epoxy resin and acrylic acid prepolymerization
60 parts of the compound, 20 parts of cosolvent and 6 parts of neutralizer;
the acrylic prepolymer is polymerized by dialdehyde compound and trimethyl s-triazine and further polymerized with methyl propyl
Methyl enoate, maleic anhydride polymerized prepolymer.
The preparation method of the acrylic prepolymer comprises the following steps:
1) dialdehyde compound and trimethyl s-triazine were mixed according to 5: 1 equivalent weight, dissolved in xylene, reacted for 12h at 100 ℃ with lewis base, and filtered to remove lewis base;
2) adding methyl methacrylate and maleic anhydride into the filtrate system obtained in the step 1), introducing nitrogen for 30min, adding an initiator, reacting at 180 ℃ for 5h, and fractionating xylene in the reaction process to obtain an acrylic prepolymer;
the Lewis base is selected from potassium hydroxide and sodium hydroxide; the molar ratio of the Lewis base to the trimethyl s-triazine is 2: 3;
the initiator is BPO, and the dosage of the initiator accounts for 0.1-0.015 percent of the total mass of the system;
the general formula of the dialdehyde compound is OHC- (CH 2) 6-CHO;
the mol ratio of the methyl methacrylate to the trimethyl s-triazine is 20: 1;
the molar ratio of the methyl methacrylate to the maleic anhydride is 1.2: 1;
the preparation method of the epoxy resin-acrylic resin double-modified waterborne alkyd resin coating specifically comprises the following steps:
1) preheating acrylic prepolymer to 80 ℃, and adding E20 bisphenol A epoxy resin and a catalyst (tetraethylammonium bromide)
0.01-1wt percent of acrylic acid modified bisphenol A epoxy resin, and a polymerization inhibitor (2, 6-di-tert-butyl-p-cresol/0.01-1 wt percent), adding into the acrylic acid prepolymer, heating to 110 ℃, and stopping the reaction when the acid value is lower than 6mgKOH/g through heat preservation reaction; 2) adding polybasic acid, polyalcohol and trimellitic anhydride into a reaction kettle according to a given proportion, and reacting at 230 DEG C
Stopping the reaction until the acid value is 10mg KOH/g;
3) adding the product obtained in the step 1) into the step 2), adding a cosolvent, and reacting for 6 hours at the temperature of 80 ℃;
4) cooling to 50 deg.C, adding neutralizer, reacting for 40min, adding deionized water, adjusting solid content to 95%,
and (7) discharging.
The polyalcohol is selected from a complex of pentaerythritol and sorbitol, and the equivalent ratio of hydroxyl content of the polyalcohol to the hydroxyl content of the sorbitol is 1: 1;
the polybasic acid is selected from soybean oil fatty acid, the acid value is 198-204mgKOH/g, and the iodine value is 120-
125mgKOH/g;
Example 4
The waterborne alkyd resin based on the epoxy resin-acrylic resin is prepared from the following components in parts by weight:
80 parts of polyol, 60 parts of polybasic acid, 12 parts of water-based monomer, 6 parts of bisphenol A epoxy resin and 50 parts of acrylic prepolymer
15 parts of cosolvent and 4 parts of neutralizer;
the acrylic prepolymer is polymerized by dialdehyde compound and trimethyl s-triazine and further polymerized by methyl propyl
Methyl enoate, maleic anhydride polymerized prepolymer.
The preparation method of the acrylic prepolymer comprises the following steps:
1) dialdehyde compound and trimethyl s-triazine are mixed according to a ratio of 4: 1 equivalent, dissolved in xylene at 80 ℃ in the Lewis acid
Stopping the reaction after the alkali reacts for 10 hours, and filtering to remove the Lewis base;
2) adding methyl methacrylate and maleic anhydride into the filtrate system obtained in the step 1), introducing nitrogen for 25min,
adding an initiator, reacting for 4 hours at 170 ℃, and distilling off xylene in the reaction process to obtain an acrylic acid prepolymer;
the Lewis base is selected from potassium hydroxide and sodium hydroxide; moles of said Lewis base and trimethyl s-triazine
The molar ratio is 2: 3;
the initiator is BPO, and the dosage of the initiator accounts for 0.1-0.015 percent of the total mass of the system;
the general formula of the dialdehyde compound is OHC- (CH 2) 4-CHO;
the mol ratio of the methyl methacrylate to the trimethyl s-triazine is 16: 1;
the molar ratio of the methyl methacrylate to the maleic anhydride is 1.1: 1;
the preparation method of the epoxy resin-acrylic resin double-modified waterborne alkyd resin coating specifically comprises the following steps:
1) preheating acrylic prepolymer to 76 ℃, and adding E20 bisphenol A epoxy resin and a catalyst (tetraethylammonium bromide)
0.01-1wt percent of polymerization inhibitor and 0.01-1wt percent of polymerization inhibitor (2, 6-di-tert-butyl-p-cresol), adding into acrylic prepolymer, heating
Keeping the temperature to 10 ℃, and stopping the reaction until the acid value is lower than 6mgKOH/g to obtain acrylic acid modified bisphenol A epoxy resin;
2) taking polybasic acid, polyalcohol and trimellitic anhydride according to a given proportion, adding into a reaction kettle, and reacting at 200 DEG C
Stopping the reaction until the acid value is 6mg KOH/g;
3) adding the product obtained in the step 1) into the step 2), adding a cosolvent, and reacting for 5 hours at the temperature of 60 ℃;
4) cooling to 50 deg.C, adding neutralizer, reacting for 30-40min, adding deionized water, and adjusting solid content
85 percent, and discharging.
The polyalcohol is selected from a complex of pentaerythritol and sorbitol, and the equivalent ratio of hydroxyl content of the polyalcohol to the hydroxyl content of the sorbitol is 1: 1;
the polybasic acid is selected from soybean oil fatty acid, the acid value is 198-204mgKOH/g, and the iodine value is 120-
125mgKOH/g;
Performance test
The alkyd resins prepared in examples 2 to 4 were compared with commercially available alkyd resins and formulated as alcohols according to the formulation in Table 1
Testing the adhesive force, surface drying and actual drying of the acid resin water paint; and (5) water resistance of the initial paint. The test results are shown in Table 2.
TABLE 1 waterborne alkyd paint formulation
TABLE 2 waterborne alkyd paint Properties