Water-based environment-friendly coating and preparation method thereof

Abstract

The application discloses an aqueous environment-friendly paint and a preparation method thereof. The aqueous environment-friendly paint comprises the following raw materials in parts by weight: 100-120 parts of polyurethane emulsion, 0.05-0.1 parts of defoaming agent, 1.5-3 parts of dispersing agent, 15-20 parts of modified filler, 3-5 parts of 1-hydroxycyclohexyl phenyl ketone, 20-30 parts of methyl methacrylate and 10-20 parts of water. The surface of the modified filler contains long-chain organosilicon segments, so that a hydrophobic film can be formed after the paint film is dried; the presence of a silicon dioxide matrix can prevent water from directly contacting polyurethane molecular segments, thereby increasing the water resistance of the paint film. The modified monomer has a hyperbranched structure and contains organosilicon segments on a molecular chain; meanwhile, long-chain alkenes of side chains can be grafted with methyl methacrylate and double bonds on the modified filler when irradiated by ultraviolet light, thereby forming new crosslinking sites on the surface of the paint film, increasing the compactness of the hydrophobic film and further improving the water resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water-based paint preparation, in particular to a water-based environment-friendly paint and a preparation method thereof. BACKGROUND

[0002] With the continuous enhancement of environmental awareness, the traditional solvent-based paint is facing unprecedented challenges due to its large emission of volatile organic compounds and serious pollution of the environment. In recent years, water-based paint, as an environmentally friendly paint that can replace solvent-based paint, has developed rapidly. Its advantages such as low VOC emission, fast drying speed, and safe operation make it widely used in many fields such as construction, furniture, and automobiles. At present, the widely used water-based paints in the market include water-based inorganic zinc-rich paint, water-based epoxy paint, and water-based acrylic paint. Conventional water-based paint has poor water resistance, and after soaking in water for a period of time, it will appear blistering and peeling, which makes the paint unable to play a role in the use process. SUMMARY

[0003] The present application relates to the technical field of water-based paint preparation, in particular to a water-based environment-friendly paint and a preparation method thereof.

[0004] The object of the present application can be achieved by the following technical solutions:

[0005] A preparation method of a water-based environment-friendly paint, specifically comprising the following steps:

[0006] Step A1: polybutylene adipate glycol is added to a reaction kettle, nitrogen is introduced for protection, stirring is carried out at a rotation speed of 120-150 r / min and a temperature of 70-80℃, isophorone diisocyanate is added, and reaction is carried out for 30-40 min, 2,2-dimethylol propionic acid is added, and reaction is carried out for 1-1.5 h, modified monomer and butanediol are added, and reaction is carried out for 1-1.5 h, triethylamine is added, and reaction is carried out for 1-1.5 h, deionized water is added, stirring is carried out at a rotation speed of 500-600 r / min and a temperature of 25-30℃ for 2-3 h, and polyurethane emulsion is prepared;

[0007] Step A2: the following raw materials are weighed: polyurethane emulsion 100-120 parts, defoaming agent 0.05-0.1 parts, dispersing agent 1.5-3 parts, modified filler 15-20 parts, 1-hydroxycyclohexyl phenyl ketone 3-5 parts, methyl methacrylate 20-30 parts, and water 10-20 parts, the raw materials are mixed uniformly to obtain a water-based environment-friendly paint.

[0008] Further, the polybutylene adipate glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, modified monomer, butanediol, triethylamine and deionized water in step A1 are in a ratio of 12 mmol:23 mmol:1 mmol:1.5 mmol:8 mmol:1 mmol:200 mL, and the polybutylene adipate glycol has a molecular weight of 2000.

[0009] Further, the modified monomer is prepared by the following steps:

[0010] Step B1: uniformly mix octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and dimethyl sulfoxide, protect under nitrogen, react at a rotation speed of 120-150 r / min and a temperature of 90-95℃ for 3-5 h to obtain diamine-terminated polysiloxane, uniformly mix oleyl alcohol, epichlorohydrin, boron trifluoride ether and DMF, react at a rotation speed of 120-150 r / min and a temperature of 65-70℃ for 2-3 h, add sodium hydroxide solution, heat to 75-80℃, and react for 3-5 h to obtain a modifier;

[0011] Step B2: uniformly mix diamine-terminated polysiloxane, modifier and DMF, react at a rotation speed of 150-200 r / min, a temperature of 40-50℃ and a pH value of 11-12 for 3-5 h to obtain modified polysiloxane, uniformly mix the modified polysiloxane, 3,4-dihydroxystyrene, chloroplatinic acid and DMF, react at a rotation speed of 120-150 r / min and a temperature of 70-80℃ for 6-8 h to obtain a modified monomer.

[0012] Further, the octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in step B1 are in a ratio of 2:0.4:3:2, the oleyl alcohol, epichlorohydrin, boron trifluoride ether and sodium hydroxide solution are in a ratio of 30 mmol:30 mmol:0.9 g:20 mL, and the mass fraction of the sodium hydroxide solution is 25%.

[0013] Further, the molar ratio of the diamine-terminated polysiloxane to the modifier in step B2 is 1:4, the molar ratio of the Si-H bond on the modified polysiloxane to 3,4-dihydroxystyrene is 1:1, and the amount of chloroplatinic acid is 1‰ of the mass of 3,4-dihydroxystyrene.

[0014] Further, the modified filler is prepared by the following steps:

[0015] Step C1: L-arginine and deionized water were mixed uniformly, stirred at a rotation speed of 500-600 r / min and a temperature of 20-25℃, and then tetraethyl orthosilicate was added, and the reaction was carried out at a temperature of 80-85℃ for 20-25h to obtain hydroxyl nano-silica. The hydroxyl nano-silica was dispersed in ethanol, stirred at a rotation speed of 150-200 r / min and a temperature of 70-80℃, and then KH550 was added, and the reaction was carried out for 3-5h to obtain pretreated silica.

[0016] Step C2: n-butyllithium, n-hexane and benzene were mixed uniformly, argon was introduced to remove air, stirred at a rotation speed of 60-80 r / min and a temperature of 20-25℃, and then hexamethylcyclotrisiloxane was added, stirred for 30-40min, tetrahydrofuran was added, and the reaction was carried out for 7-9h, dimethylchlorosilane was added, and the reaction was carried out for 30-40min to obtain monohydrogen polysiloxane.

[0017] Step C3: The monohydrogen polysiloxane, allyl glycidyl ether, chloroplatinic acid and DMF were mixed uniformly, and the reaction was carried out at a rotation speed of 120-150 r / min and a temperature of 70-80℃ for 3-5h to obtain a treating agent. The pretreated silica, the treating agent and DMF were mixed uniformly, and the reaction was carried out at a rotation speed of 200-300 r / min, a temperature of 40-50℃ and a pH value of 11-12 for 4-6h to obtain modified silica. The modified silica, potassium carbonate and DMF were mixed, stirred at a rotation speed of 150-200 r / min and a temperature of 100-110℃, and then chloroethylene was added, and the reaction was carried out for 3-5h to obtain a modified filler.

[0018] Further, the use amount ratio of L-arginine, deionized water and tetraethyl orthosilicate in step C1 is 1mmol:150mL:100mmol, and the use amount of KH550 is 1% of the mass of the hydroxyl nano-silica.

[0019] Further, the use amount ratio of n-butyllithium, n-hexane, benzene, hexamethylcyclotrisiloxane, tetrahydrofuran and dimethylchlorosilane in step C2 is 7.5g:20mL:10mL:500mmol:30mL:25mmol.

[0020] Further, the molar ratio of the monohydrogen polysiloxane and the allyl glycidyl ether in step C3 is 1:1, the use amount of chloroplatinic acid is 1‰ of the mass of the allyl glycidyl ether, and the use amount ratio of the modified silica, potassium carbonate, DMF and chloroethylene is 1g:3g:20mL:1.5g.

[0021] The water-based environment-friendly paint prepared by the present application comprises the following raw materials: polyurethane emulsion, defoaming agent, dispersing agent, modified filler, 1-hydroxycyclohexyl phenyl ketone, methyl methacrylate and water, the polyurethane emulsion is prepared by reacting polyhexanedioic acid-1, 4-butanediol glycol and isophorone diisocyanate, then sequentially reacting with 2, 2-dimethylol propionic acid, modified monomer and butanediol, and finally neutralizing with triethylamine.

[0022] The modified monomer is prepared by ring-opening of octamethylcyclotetrasiloxane and tetramethylcyclotetrasiloxane as raw materials, and then polymerizing with 1, 3-bis(3-aminopropyl)-1, 1, 3, 3-tetramethyldisiloxane, the oil alcohol and epichlorohydrin are reacted to make the hydroxyl group on the oil alcohol react with the epoxy group on the epichlorohydrin, and then ring-closing under the action of sodium hydroxide solution to prepare a modifier, the diamine-terminated polysiloxane and the modifier are reacted to make the amino group on the diamine-terminated polysiloxane react with the epoxy group on the modifier to prepare a modified polysiloxane, and the modified polysiloxane and 3, 4-dihydroxystyrene are reacted to make the Si-H bond on the modified polysiloxane react with the double bond on the 3, 4-dihydroxystyrene to prepare the modified monomer.

[0023] The modified filler is prepared by hydrolysis and condensation of tetraethyl orthosilicate as raw material, and promoting hydroxylation under the action of L-arginine to prepare hydroxyl nano silicon dioxide, the hydroxyl nano silicon dioxide is treated with KH550 to graft amino groups on the surface to prepare pretreated silicon dioxide, anionic ring-opening polymerization is carried out with hexamethylcyclotrisiloxane as a reaction monomer, n-butyllithium as an initiator and dimethylchlorosilane as a capping agent to prepare monohydrogen polysiloxane, the monohydrogen polysiloxane and allyl glycidyl ether are reacted to make the Si-H bond on the monohydrogen polysiloxane react with the double bond on the allyl glycidyl ether to prepare a treatment agent, the pretreated silicon dioxide and the treatment agent are reacted to make the epoxy group on the treatment agent react with the amino group on the pretreated silicon dioxide to produce a hydroxyl group to prepare modified silicon dioxide, and the modified silicon dioxide and vinyl chloride are reacted to make the hydroxyl group on the modified silicon dioxide react with the chlorine atom site on the vinyl chloride to prepare the modified filler.

[0024] The surface of the modified filler contains long-chain organosilicon segments, so that a hydrophobic film can be formed after the paint film is dried, and the presence of the silicon dioxide matrix can prevent water from directly contacting the polyurethane molecular chain segments, thereby increasing the water resistance of the paint film, the modified monomer has a hyperbranched structure and contains organosilicon segments on the molecular chain, and at the same time, the long-chain olefins of the side chain can be grafted with methyl methacrylate and the double bonds on the modified filler under ultraviolet light, thereby forming new crosslinking sites on the surface of the paint film, increasing the density of the hydrophobic film and further improving the water resistance, and at the same time, the side chain contains a catechol structure, which can increase the adhesion of the paint. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of them. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0026] Embodiment 1

[0027] A preparation method of the water-based environment-friendly paint, specifically comprising the following steps:

[0028] Step A1: polybutylene adipate glycol is added into a reaction kettle, nitrogen protection is performed, stirring is performed under the conditions of a rotation speed of 120 r / min and a temperature of 70 DEG C, isophorone diisocyanate is added, reaction is performed for 30 min, 2,2-dimethylol propionic acid is added, reaction is performed for 1 h, modified monomer and butanediol are added, reaction is performed for 1 h, triethylamine is added, reaction is performed for 1 h, deionized water is added, stirring is performed under the conditions of a rotation speed of 500 r / min and a temperature of 25 DEG C for 2 h, and a polyurethane emulsion is prepared;

[0029] Step A2: the following raw materials are weighed: 100 parts of the polyurethane emulsion, 0.05 parts of a defoaming agent, 1.5 parts of a dispersing agent, 15 parts of modified filler, 3 parts of 1-hydroxycyclohexyl phenyl ketone, 20 parts of methyl methacrylate and 10 parts of water, the raw materials are uniformly mixed, and the water-based environment-friendly paint is obtained.

[0030] The amount ratio of the polybutylene adipate glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, modified monomer, butanediol, triethylamine and deionized water in step A1 is 12 mmol:23 mmol:1 mmol:1.5 mmol:8 mmol:1 mmol:200 mL, and the molecular weight of the polybutylene adipate glycol is 2000.

[0031] The defoaming agent in step A2 is a defoaming agent GP330, and the dispersing agent is a SN-5040 dispersing agent.

[0032] The modified monomer is prepared by the following steps:

[0033] Step B1: octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and dimethyl sulfoxide were mixed uniformly, and then were reacted for 3 h under the conditions of nitrogen protection, a rotation speed of 120 r / min and a temperature of 90℃ to prepare a diamine-terminated polysiloxane. Oil alcohol, epichlorohydrin, boron trifluoride ether and DMF were mixed uniformly, and then were reacted for 2 h under the conditions of a rotation speed of 120 r / min and a temperature of 65℃. Then, sodium hydroxide solution was added, and the mixture was reacted for 3 h under the conditions of a temperature of 75℃ to prepare a modifier.

[0034] Step B2: the diamine-terminated polysiloxane, the modifier and DMF were mixed uniformly, and then were reacted for 3 h under the conditions of a rotation speed of 150 r / min, a temperature of 40℃ and a pH value of 11 to prepare a modified polysiloxane. The modified polysiloxane, 3,4-dihydroxystyrene, chloroplatinic acid and DMF were mixed uniformly, and then were reacted for 6 h under the conditions of a rotation speed of 120 r / min and a temperature of 70℃ to prepare a modified monomer.

[0035] The octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in step B1 were used in a ratio of 2:0.4:3:2. The oil alcohol, epichlorohydrin, boron trifluoride ether and sodium hydroxide solution were used in a ratio of 30 mmol:30 mmol:0.9 g:20 mL. The mass fraction of the sodium hydroxide solution was 25%.

[0036] The molar ratio of the diamine-terminated polysiloxane to the modifier in step B2 was 1:4. The molar ratio of the Si-H bond on the modified polysiloxane to 3,4-dihydroxystyrene was 1:1. The amount of chloroplatinic acid was 1‰ of the mass of 3,4-dihydroxystyrene.

[0037] The modified filler was prepared by the following steps:

[0038] Step C1: L-arginine and deionized water were mixed uniformly, and then were stirred under the conditions of a rotation speed of 500 r / min and a temperature of 20℃. Then, tetraethyl orthosilicate was added, and the mixture was reacted for 20 h under the conditions of a temperature of 80℃ to prepare hydroxyl nano-silica. The hydroxyl nano-silica was dispersed in ethanol, and then was stirred under the conditions of a rotation speed of 150 r / min and a temperature of 70℃. Then, KH550 was added, and the mixture was reacted for 3 h to prepare pretreated silica.

[0039] Step C2: uniformly mix n-butyllithium, n-hexane and benzene, remove air by passing argon, stir at a rotation speed of 60 r / min and a temperature of 20℃, add hexamethylcyclotrisiloxane, stir for 30 min, add tetrahydrofuran, react for 7 h, add dimethylchlorosilane, react for 30 min, and obtain monohydrogen polysiloxane;

[0040] Step C3: uniformly mix monohydrogen polysiloxane, allyl alcohol glycidyl ether, chloroplatinic acid and DMF, react for 3 h at a rotation speed of 120 r / min and a temperature of 70℃, obtain a treating agent, uniformly mix the pretreated silica, the treating agent and DMF, react for 4 h at a rotation speed of 200 r / min, a temperature of 40℃ and a pH value of 11, obtain modified silica, mix the modified silica, potassium carbonate and DMF, stir at a rotation speed of 150 r / min and a temperature of 100℃, add chloroethylene, react for 3 h, and obtain a modified filler.

[0041] The use amount ratio of L-arginine, deionized water and tetraethyl orthosilicate in step C1 is 1 mmol: 150 mL: 100 mmol, and the use amount of KH550 is 1% of the mass of the hydroxyl nano-silica.

[0042] The use amount ratio of n-butyllithium, n-hexane, benzene, hexamethylcyclotrisiloxane, tetrahydrofuran and dimethylchlorosilane in step C2 is 7.5 g: 20 mL: 10 mL: 500 mmol: 30 mL: 25 mmol.

[0043] The molar ratio of monohydrogen polysiloxane and allyl alcohol glycidyl ether in step C3 is 1:1, the use amount of chloroplatinic acid is 1‰ of the mass of the allyl alcohol glycidyl ether, and the use amount ratio of modified silica, potassium carbonate, DMF and chloroethylene is 1 g: 3 g: 20 mL: 1.5 g.

[0044] Example 2

[0045] A preparation method of a water-based environment-friendly coating, specifically comprising the following steps:

[0046] Step A1: add poly-1,4-butanediol adipate diol into a reaction kettle, protect by passing nitrogen, stir at a rotation speed of 120 r / min and a temperature of 75℃, add isophorone diisocyanate, react for 35 min, add 2,2-dimethylol propionic acid, react for 1 h, add modified monomer and butanediol, react for 1.5 h, add triethylamine, react for 1 h, add deionized water, stir at a rotation speed of 600 r / min and a temperature of 25℃ for 3 h, and obtain a polyurethane emulsion;

[0047] Step A2: Take the following weight parts of raw materials: polyurethane emulsion 110 parts, defoaming agent 0.08 parts, dispersing agent 2 parts, modified filler 18 parts, 1-hydroxycyclohexyl phenyl ketone 4 parts, methyl methacrylate 25 parts and water 15 parts, mix the raw materials uniformly to obtain the water-based environmental protection coating.

[0048] The use amount ratio of the polybutylene adipate glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, modified monomer, butanediol, triethylamine and deionized water in step A1 is 12mmol:23mmol:1mmol:1.5mmol:8mmol:1mmol:200mL, and the molecular weight of the polybutylene adipate glycol is 2000.

[0049] The defoaming agent in step A2 is defoaming agent GPE3000, and the dispersing agent is Soka l an CP5 dispersing agent.

[0050] The modified monomer is prepared by the following steps:

[0051] Step B1: Mix octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and dimethyl sulfoxide uniformly, protect under nitrogen, react for 4h under the condition of 120r / min rotation speed and 95℃ temperature, prepare diamine-terminated polysiloxane, mix oleyl alcohol, epichlorohydrin, boron trifluoride ether and DMF uniformly, react for 2h under the condition of 120r / min rotation speed and 70℃ temperature, add sodium hydroxide solution, heat to 80℃, react for 4h, prepare modifier;

[0052] Step B2: Mix diamine-terminated polysiloxane, modifier and DMF uniformly, react for 4h under the condition of 150r / min rotation speed, 45℃ temperature and pH value of 12, prepare modified polysiloxane, mix the modified polysiloxane, 3,4-dihydroxystyrene, chloroplatinic acid and DMF uniformly, react for 7h under the condition of 120r / min rotation speed and 75℃ temperature, prepare modified monomer.

[0053] The use amount ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in step B1 is 2:0.4:3:2, the use amount ratio of oleyl alcohol, epichlorohydrin, boron trifluoride ether and sodium hydroxide solution is 30mmol:30mmol:0.9g:20mL, and the mass fraction of the sodium hydroxide solution is 25%.

[0054] The molar ratio of the diamine end polysiloxane and the modifier described in step B2 is 1:4, the molar ratio of the Si-H bond on the modified polysiloxane and 3,4-dihydroxystyrene is 1:1, and the amount of chloroplatinic acid used is 1 ‰ of the mass of 3,4-dihydroxystyrene.

[0055] The modified filler is prepared by the following steps:

[0056] Step C1: L-arginine and deionized water are uniformly mixed, stirred at a rotation speed of 600 r / min and a temperature of 20 ℃, and tetraethyl orthosilicate is added, and the temperature is raised to 85 ℃, and the reaction is carried out for 20 h to prepare hydroxyl nano silicon dioxide, and the hydroxyl nano silicon dioxide is dispersed in ethanol, stirred at a rotation speed of 200 r / min and a temperature of 75 ℃, and KH550 is added, and the reaction is carried out for 4 h to prepare pretreated silicon dioxide;

[0057] Step C2: n-butyllithium, n-hexane and benzene are uniformly mixed, argon is introduced to remove air, stirred at a rotation speed of 60 r / min and a temperature of 25 ℃, and hexamethylcyclotrisiloxane is added, stirred for 35 min, tetrahydrofuran is added, and the reaction is carried out for 8 h, and dimethylchlorosilane is added, and the reaction is carried out for 35 min to prepare monohydrogen polysiloxane;

[0058] Step C3: The monohydrogen polysiloxane, allyl alcohol glycidyl ether, chloroplatinic acid and DMF are uniformly mixed, and the reaction is carried out at a rotation speed of 120 r / min and a temperature of 75 ℃ for 4 h to prepare a treating agent, and the pretreated silicon dioxide, the treating agent and DMF are uniformly mixed, and the reaction is carried out at a rotation speed of 200 r / min, a temperature of 45 ℃ and a pH value of 12 for 5 h to prepare modified silicon dioxide, and the modified silicon dioxide, potassium carbonate and DMF are mixed, stirred at a rotation speed of 150 r / min and a temperature of 105 ℃, and chloroethylene is added, and the reaction is carried out for 4 h to prepare a modified filler.

[0059] The amount ratio of L-arginine, deionized water and tetraethyl orthosilicate described in step C1 is 1 mmol:150 mL:100 mmol, and the amount of KH550 is 1% of the mass of the hydroxyl nano silicon dioxide.

[0060] The amount ratio of n-butyllithium, n-hexane, benzene, hexamethylcyclotrisiloxane, tetrahydrofuran and dimethylchlorosilane described in step C2 is 7.5 g:20 mL:10 mL:500 mmol:30 mL:25 mmol.

[0061] The molar ratio of the monohydrogen polysiloxane and the allyl alcohol glycidyl ether described in step C3 is 1:1, the amount of chloroplatinic acid used is 1 ‰ of the mass of the allyl alcohol glycidyl ether, and the amount ratio of the modified silicon dioxide, potassium carbonate, DMF and chloroethylene is 1 g:3 g:20 mL:1.5 g.

[0062] Embodiment 3

[0063] A preparation method of the water-based environmental protection paint, specifically comprising the following steps:

[0064] Step A1: polybutylene adipate glycol is added into a reaction kettle, nitrogen protection is conducted, stirring is conducted under the condition that the rotating speed is 150 r / min and the temperature is 80℃, isophorone diisocyanate is added, reaction is conducted for 40 min, 2,2-dimethylol propionic acid is added, reaction is conducted for 1.5 h, modified monomer and butanediol are added, reaction is conducted for 1.5 h, triethylamine is added, reaction is conducted for 1.5 h, deionized water is added, stirring is conducted under the condition that the rotating speed is 600 r / min and the temperature is 30℃ for 3 h, and a polyurethane emulsion is prepared;

[0065] Step A2: the following raw materials are weighed: 120 parts of the polyurethane emulsion, 0.1 part of a defoaming agent, 3 parts of a dispersing agent, 20 parts of modified filler, 5 parts of 1-hydroxycyclohexyl phenyl ketone, 30 parts of methyl methacrylate and 20 parts of water, the raw materials are uniformly mixed, and the water-based environmental protection paint is prepared.

[0066] The amount ratio of the polybutylene adipate glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, modified monomer, butanediol, triethylamine and deionized water in step A1 is 12 mmol:23 mmol:1 mmol:1.5 mmol:8 mmol:1 mmol:200 mL, and the molecular weight of the polybutylene adipate glycol is 2000.

[0067] The defoaming agent in step A2 is a defoaming agent DF103, and the dispersing agent is an Ecodis P90 dispersing agent.

[0068] The modified monomer is prepared by the following steps:

[0069] Step B1: octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and dimethyl sulfoxide are uniformly mixed, nitrogen protection is conducted, reaction is conducted under the condition that the rotating speed is 150 r / min and the temperature is 95℃ for h, a diamine-terminated polysiloxane is prepared, oleyl alcohol, epichlorohydrin, boron trifluoride ether and DMF are uniformly mixed, reaction is conducted under the condition that the rotating speed is 150 r / min and the temperature is 70℃ for 3 h, sodium hydroxide solution is added, the temperature is increased to 80℃, and reaction is conducted for 5 h, and a modifier is prepared;

[0070] Step B2: the diamine-terminated polysiloxane, the modifier and DMF were mixed uniformly, and the reaction was carried out at a rotation speed of 200 r / min, a temperature of 50℃ and a pH value of 12 for 5 h to obtain a modified polysiloxane; the modified polysiloxane, 3,4-dihydroxystyrene, chloroplatinic acid and DMF were mixed uniformly, and the reaction was carried out at a rotation speed of 150 r / min and a temperature of 80℃ for 8 h to obtain a modified monomer.

[0071] The use amount ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in step B1 was 2:0.4:3:2, and the use amount ratio of oleyl alcohol, epichlorohydrin, boron trifluoride ether and sodium hydroxide solution was 30 mmol:30 mmol:0.9 g:20 mL, and the mass fraction of the sodium hydroxide solution was 25%.

[0072] The molar ratio of the diamine-terminated polysiloxane and the modifier in step B2 was 1:4, the molar ratio of the Si-H bond on the modified polysiloxane and 3,4-dihydroxystyrene was 1:1, and the use amount of chloroplatinic acid was 1 ‰ of the mass of 3,4-dihydroxystyrene.

[0073] The modified filler was prepared by the following steps:

[0074] Step C1: L-arginine and deionized water were mixed uniformly, and stirring was carried out at a rotation speed of 600 r / min and a temperature of 25℃, and then tetraethyl orthosilicate was added, the temperature was increased to 85℃, and the reaction was carried out for 25 h to obtain hydroxyl nano-silica; the hydroxyl nano-silica was dispersed in ethanol, stirring was carried out at a rotation speed of 200 r / min and a temperature of 80℃, and then KH550 was added, and the reaction was carried out for 5 h to obtain pretreated silica;

[0075] Step C2: n-butyllithium, n-hexane and benzene were mixed uniformly, argon was introduced to remove air, stirring was carried out at a rotation speed of 80 r / min and a temperature of 25℃, and then hexamethylcyclotrisiloxane was added, stirring was carried out for 40 min, tetrahydrofuran was added, and the reaction was carried out for 9 h, and then dimethylchlorosilane was added, and the reaction was carried out for 40 min to obtain a monohydrogen polysiloxane;

[0076] Step C3: The monohydrogen polysiloxane, allyl alcohol glycidyl ether, chloroplatinic acid and DMF were mixed uniformly, and the reaction was carried out at a rotation speed of 150 r / min and a temperature of 80°C for 5 h to obtain a treating agent. The pretreated silica, the treating agent and DMF were mixed uniformly, and the reaction was carried out at a rotation speed of 300 r / min, a temperature of 50°C and a pH value of 12 for 6 h to obtain modified silica. The modified silica, potassium carbonate and DMF were mixed, and the reaction was carried out by stirring and adding chloroethylene at a rotation speed of 200 r / min and a temperature of 110°C for 5 h to obtain a modified filler.

[0077] The use amount ratio of L-arginine, deionized water and tetraethyl orthosilicate in Step C1 is 1 mmol: 150 mL: 100 mmol, and the use amount of KH550 is 1% of the mass of the hydroxyl nano-silica.

[0078] The use amount ratio of n-butyllithium, n-hexane, benzene, hexamethylcyclotrisiloxane, tetrahydrofuran and dimethylchlorosilane in Step C2 is 7.5 g: 20 mL: 10 mL: 500 mmol: 30 mL: 25 mmol.

[0079] The molar ratio of the monohydrogen polysiloxane and the allyl alcohol glycidyl ether in Step C3 is 1:1, the use amount of chloroplatinic acid is 1‰ of the mass of the allyl alcohol glycidyl ether, and the use amount ratio of the modified silica, potassium carbonate, DMF and chloroethylene is 1 g: 3 g: 20 mL: 1.5 g.

[0080] Comparative Example 1

[0081] This comparative example is the same as Example 1 except that styrene is used instead of 3,4-dihydroxystyrene.

[0082] Comparative Example 2

[0083] This comparative example is the same as Example 1 except that propylene oxide is used instead of the modifying agent.

[0084] Comparative Example 3

[0085] This comparative example is the same as Example 1 except that nano-silica is used instead of the modified filler.

[0086] Comparative Example 4

[0087] This comparative example is the same as Example 1 except that propylene oxide is used instead of the treating agent.

[0088] The water-based paint prepared from Examples 1-3 and Comparative Examples 1-4 was coated on tinplate according to the standard of GB / T1733-1993, irradiated with 365 nm ultraviolet light for 60 s, the coating film thickness was 85 μm, the edges were sealed with paraffin, and the film state was observed by immersion in water, the adhesion grade was detected according to the standard of GB / T9286-2021, and the test results are shown in the following table.

[0089]

[0090] From the above table, it can be seen that the application has good water resistance and excellent adhesion.

[0091] The above content is only an example and description of the concept of the present application. Those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the concept of the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A method for preparing an aqueous environmentally friendly coating, characterized by: Specifically comprising the following steps: Step A1: polybutylene adipate glycol is added into a reaction kettle, nitrogen is introduced for protection, stirring and adding isophorone diisocyanate, reaction is carried out, 2,2-dimethylol propionic acid is added, reaction is carried out, modified monomer and butanediol are added, reaction is carried out, triethylamine is added, reaction is carried out, deionized water is added for stirring treatment, and polyurethane emulsion is prepared; Step A2: the following raw materials are weighed: polyurethane emulsion 100-120 parts, defoaming agent 0.05-0.1 parts, dispersing agent 1.5-3 parts, modified filler 15-20 parts, 1-hydroxycyclohexyl phenyl ketone 3-5 parts, methyl methacrylate 20-30 parts and water 10-20 parts, the raw materials are uniformly mixed, and water-based environmental protection coating is prepared; The modified monomer is prepared by the following steps: Step B1: octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and dimethyl sulfoxide are uniformly mixed, nitrogen is introduced for protection, reaction is carried out, diamine-terminated polysiloxane is prepared, oleyl alcohol, epichlorohydrin, boron trifluoride ether and DMF are mixed and reacted, sodium hydroxide solution is added, and the mixture is reacted at elevated temperature to prepare a modifier; Step B2: the diamine-terminated polysiloxane, the modifier and DMF are mixed and reacted to prepare modified polysiloxane, the modified polysiloxane, 3,4-dihydroxystyrene, chloroplatinic acid and DMF are mixed and reacted to prepare a modified monomer; The modified filler is prepared by the following steps: Step C1: L-arginine and deionized water are mixed, stirred and added with tetraethyl orthosilicate, and the mixture is reacted at elevated temperature to prepare hydroxyl nano silicon dioxide, the hydroxyl nano silicon dioxide is dispersed in ethanol, stirred and added with KH550, and the mixture is reacted to prepare pretreated silicon dioxide; Step C2: n-butyllithium, n-hexane and benzene are uniformly mixed, argon is introduced to remove air, stirred and added with hexamethylcyclotrisiloxane, stirred and treated, added with tetrahydrofuran, reacted, added with dimethylchlorosilane, and reacted to prepare monohydrogen polysiloxane; Step C3: the monohydrogen polysiloxane, allyl glycidyl ether, chloroplatinic acid and DMF are mixed and reacted to prepare a treatment agent, the pretreated silicon dioxide, the treatment agent and DMF are mixed and reacted to prepare modified silicon dioxide, the modified silicon dioxide, potassium carbonate and DMF are mixed, stirred and added with vinyl chloride, and the mixture is reacted to prepare a modified filler.

2. The method according to claim 1, characterized in that: The polybutylene adipate glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, modified monomer, butanediol, triethylamine and deionized water in step A1 are used in a ratio of 12 mmol:23 mmol:1 mmol:1.5 mmol:8 mmol:1 mmol:200 mL.

3. The method for preparing a water-based environmentally friendly coating according to claim 1, characterized in that: The octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in step B1 are used in a ratio of 2:0.4:3:2, and the oleyl alcohol, epichlorohydrin, boron trifluoride etherate and sodium hydroxide solution are used in a ratio of 30 mmol:30 mmol:0.9 g:20 mL.

4. The method according to claim 1, characterized in that: The molar ratio of the bis-amine-terminated polysiloxane and the modifying agent in step B2 is 1:4, and the molar ratio of the Si-H bond on the modified polysiloxane and 3,4-dihydroxystyrene is 1:

1.

5. The method according to claim 1, wherein the water-based environmentally friendly paint is prepared by adding 0.1 to 1 wt% of the dispersant to 100 parts by weight of the water-based environmentally friendly paint. The L-arginine, deionized water and tetraethyl orthosilicate in step C1 are used in a ratio of 1 mmol:150 mL:100 mmol, and the amount of KH550 used is 1% of the mass of the hydroxyl nano-silica.

6. The method for preparing a water-based environmentally friendly coating according to claim 1, characterized in that: The n-butyllithium, n-hexane, benzene, hexamethylcyclotrisiloxane, tetrahydrofuran and dimethylchlorosilane in step C2 are used in a ratio of 7.5 g:20 mL:10 mL:500 mmol:30 mL:25 mmol.

7. The method for preparing a water-based environmentally friendly coating according to claim 1, characterized in that: The molar ratio of the monohydrogenpolysiloxane and the allyl alcohol glycidyl ether in step C3 is 1:1, and the modified silica, potassium carbonate, DMF and vinyl chloride are used in a ratio of 1 g:3 g:20 mL:1.5 g.

8. An aqueous, environmentally friendly coating material, characterized by: Prepared according to the preparation method of any one of claims 1-7. Prepared according to the preparation method of any one of claims 1-7.

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