A nonionic double-bond monomer, an aqueous acrylic polymer prepared therefrom, and applications thereof

Abstract

The present invention discloses a non-ionic double-bond monomer, an aqueous acrylic polymer prepared therefrom, and applications thereof, belonging to the technical field of aqueous temporary protection materials. The present invention provides a non-ionic double-bond monomer, which is prepared from a dibasic acid chain extender, methacrylic acid, a catalyst, an inhibitor, and polyethylene glycol. By using the non-ionic double-bond monomer as a raw material to prepare the aqueous acrylic polymer, the adhesion of the aqueous acrylic polymer is reduced, and the peelability is improved; at the same time, the particle size of the aqueous acrylic polymer is greatly increased, and the film-forming density is reduced. The aqueous acrylic polymer prepared by the continuous dropping polymerization process of the present invention has good high-temperature peelability. When the aqueous acrylic polymer is applied to the high-temperature glass baking paint color matching process, it can effectively prevent the penetration of the topcoat into the primer coating and maintain the peelability of the coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of water-based temporary protection materials, and particularly relates to a non-ionic double-bond monomer, a water-based acrylic polymer prepared therefrom, and applications thereof. Background Art

[0002] Peelable protective films are mainly applied to the temporary protection of various materials, instruments, mechanical metal parts, and glass surfaces. Since materials are prone to collision or erosion by solvents and salt spray during transportation, storage, processing, and assembly, it is generally necessary to protect their surfaces. In addition, for the overprinting process of some industrial products, a coating is sprayed on their surfaces to protect the surfaces, and the coating can be peeled off as a whole after drying without affecting the material properties. Spraying a protective coating is currently the most effective and convenient method to solve this problem.

[0003] For the glass baking paint overprinting process, its main process steps are as follows: first, spray a water-soluble acrylic baking paint primer and keep it at 160 °C for 20 minutes, then apply an oil-based peelable acrylic intermediate coat at 90 °C and heat up to 160 °C and keep it at this temperature for 20 minutes, and finally apply 1 - 3 coats of water-soluble acrylic color paint at 90 °C according to customer requirements and keep it at 160 °C for 20 minutes. The entire process flow operates compactly. However, due to the slow drying of the water-based peelable acrylic resin film, the softening of the film at high temperatures, and the easy erosion of the water-based peelable acrylic resin film by the primer or topcoat water-soluble acrylic resin at high temperatures, resulting in non-peelability or color differences in the color paint, currently, oil-based peelable acrylics are generally used as the intermediate coat resin in the high-temperature overprinting process field.

[0004] Therefore, it is of great significance to develop a peelable water-based acrylic polymer that can be applied to the high-temperature overprinting process field, and there are no related products on the market currently. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a non-ionic double-bond monomer, a water-based acrylic polymer prepared therefrom, and applications thereof. The water-based acrylic polymer has good peelability, and at the same time has good water resistance, scrub resistance, and adhesion, and can be applied to the high-temperature glass baking paint overprinting process.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a non-ionic double bond monomer, which is prepared from a dibasic acid chain extender, methacrylic acid, a catalyst, an inhibitor, and polyethylene glycol; the mass ratio of the dibasic acid chain extender, methacrylic acid, the catalyst, the inhibitor, and polyethylene glycol is dibasic acid chain extender: methacrylic acid: catalyst: inhibitor: polyethylene glycol = (0.6 - 1):(8 - 12):(0.2 - 0.6):(0.2 - 0.6):(8 - 15).

[0008] In a second aspect, the present invention provides a method for preparing the above non-ionic double bond monomer, comprising the following steps:

[0009] S1. Mix the dibasic acid chain extender, the catalyst, and polyethylene glycol, and carry out an esterification reaction at 80 - 120 °C;

[0010] S2. After the reaction in step S1 is completed, add methacrylic acid and the inhibitor, and carry out an esterification reaction at 90 - 120 °C. After the reaction is completed, cool down and discharge to obtain the non-ionic double bond monomer.

[0011] The raw materials for preparing the non-ionic double bond monomer of the present invention include a dibasic acid chain extender, methacrylic acid, a catalyst, an inhibitor, and polyethylene glycol. Among them, the dibasic acid chain extender and polyethylene glycol undergo an esterification reaction under the action of a catalyst to form an ester. Since the amount of the dibasic acid chain extender used is small and the amount of polyethylene glycol used is large, the dibasic acid chain extender reacts completely, and finally a polyester diol with hydroxyl groups at both ends is formed, which further reacts with methacrylic acid to generate a non-ionic double bond monomer capped with a double bond structure. The addition of the inhibitor can inhibit the polymerization reaction and control the chain length and structure of the generated non-ionic double bond monomer. It provides a basis for subsequent use in preparing a peelable waterborne acrylic polymer.

[0012] Preferably, the molar ratio of the dibasic acid chain extender, methacrylic acid, the catalyst, the inhibitor, and polyethylene glycol is dibasic acid chain extender: methacrylic acid: catalyst: inhibitor: polyethylene glycol = 0.6:8:0.2:0.6:12. The inventors found through experiments that when the non-ionic double bond monomer obtained by using the above specific component ratio as a raw material is used to prepare a waterborne acrylic polymer, the waterborne acrylic polymer has excellent peelability and the residual rate of film peeling is 0.

[0013] Preferably, the dibasic acid chain extender is at least one of succinic acid, glutaric acid, 1,4-cyclohexanedicarboxylic acid, and adipic acid; the catalyst is any one of p-toluenesulfonic acid and phosphoric acid; the inhibitor is any one of p-methoxyphenol and 2-sec-butyl-4,6-dinitrophenol; the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 550, polyethylene glycol 1000, and polyethylene glycol 2000.

[0014] Using polyethylene glycols with different molecular weights will affect the structure of the prepared nonionic double-bond monomers, and further affect the elasticity and peelability of the waterborne acrylic polymers prepared therefrom. The inventors found through experiments that when the polyethylene glycol described in the present application is selected, it has good compatibility with the reaction system, and the finally obtained waterborne acrylic polymer has good peelability.

[0015] In a third aspect, the present invention provides a waterborne acrylic polymer, comprising the following raw materials in parts by weight: 400 - 600 parts of water, acrylic monomers, vinyl monomers, 10 - 20 parts of emulsifier, 10 - 20 parts of organofluorine monomers, 10 - 30 parts of silane coupling agent, 10 - 20 parts of initiator, 1 - 10 parts of molecular weight regulator, 60 - 100 parts of the above nonionic double-bond monomers, 10 - 20 parts of neutralizer; the total weight parts of the acrylic monomers and the vinyl monomers are 300 - 350 parts.

[0016] For the preparation of ordinary waterborne acrylic polymers, carboxyl-containing acrylic monomers are generally added to meet the performance requirements. However, the addition of carboxyl-containing acrylic monomers makes it difficult to peel the acrylic emulsion film after film formation, and cannot meet the requirements of peelability. In the present invention, by selecting acrylic ester monomers with different properties and ensuring the basic performance of the product, at the same time, the nonionic double-bond monomers prepared above are used to replace part of the carboxyl-containing acrylic monomers, increasing the peelability of the acrylic polymer. On the one hand, the addition of the nonionic double-bond monomers reduces the film adhesion and improves the peelability; on the other hand, the addition of the nonionic double-bond monomers can greatly increase the particle size of the acrylic polymer and reduce the denseness of film formation, which can further improve the peelability of the prepared waterborne acrylic polymer. In addition, the added organofluorine monomers and silane coupling agent can be oriented on the surface of the emulsion film after the acrylic latex particles are extruded into a film, thereby improving the high-temperature anti-stickiness of the emulsion film.

[0017] Preferably, the waterborne acrylic polymer comprises the following raw materials in parts by weight: 450 - 600 parts of water, acrylic monomers, vinyl monomers, 15 - 20 parts of emulsifier, 10 - 15 parts of organofluorine monomers, 20 - 30 parts of silane coupling agent, 10 - 15 parts of initiator, 1 - 5 parts of molecular weight regulator, 60 - 80 parts of the above nonionic double-bond monomers, 15 - 20 parts of neutralizer; the total weight parts of the acrylic monomers and the vinyl monomers are 300 - 320 parts. When the preferred ratio is selected, the prepared waterborne acrylic polymer has good stability and good peelability, and the residual rate of film peeling does not exceed 5%.

[0018] Preferably, the aqueous acrylic polymer comprises the following raw materials in parts by weight: 450 parts of water, acrylic monomers, vinyl monomers, 20 parts of emulsifier, 20 parts of organofluorine monomers, 10 parts of silane coupling agent, 10 parts of initiator, 2 parts of molecular weight regulator, 80 parts of the above-mentioned nonionic double-bond monomers, and 20 parts of neutralizer; the total weight parts of the acrylic monomers and the vinyl monomers are 300 parts. The aqueous acrylic polymer prepared under the above component ratio has good adhesion, water resistance, scrub resistance, and good storage stability. The residual rate of film peeling is 0, and it has excellent peelability.

[0019] Preferably, the acrylic monomers are at least one of butyl acrylate, acrylic acid, isooctyl acrylate, lauryl acrylate, isobornyl methacrylate, vinyl versatate, methyl methacrylate, and neopentyl glycol diacrylate; the vinyl monomer is styrene.

[0020] According to the design requirements, different combinations of acrylic monomers can be selected to prepare acrylic polymers with different glass transition temperatures to meet different design requirements.

[0021] Preferably, the organofluorine monomers are at least one of trifluoroethyl methacrylate, hexafluorobutyl methacrylate, 2-perfluoroalkyl ethyl methacrylate, and 2-perfluorohexyl ethyl acrylate.

[0022] By introducing fluorine-containing functional monomers, the present invention greatly reduces the surface tension of the aqueous acrylic resin and is beneficial to improving the anti-sticking property of the resin.

[0023] Preferably, the silane coupling agent is at least one of phenyltrimethoxysilane, vinyltriethoxysilane, dodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, and vinyltrimethoxysilane.

[0024] The structure of the silane coupling agent contains a large number of silicon-oxygen chains, and the side chain contains other organic groups connected to the silicon atom, which can provide both organic and inorganic structures and is beneficial to improving water resistance and scrub resistance.

[0025] Preferably, the emulsifier is at least one of sodium dodecyl sulfate, sodium vinyl sulfonate, and sodium dodecylbenzenesulfonate. The emulsifier of the present invention has excellent emulsifying ability, can improve the dispersion and emulsification properties of monomers, and improve the polymerization efficiency.

[0026] Preferably, the initiator is at least one of ammonium persulfate and potassium persulfate. Persulfate is easily decomposed into free radicals when heated, and undergoes free radical grafting, copolymerization, crosslinking and other reactions with active double bonds, so that the emulsion forms a network structure after coating, improving the mechanical properties of the coating film.

[0027] Preferably, the molecular weight regulator is at least one of n-dodecyl mercaptan and mercaptoethanol. The molecular weight regulator selected in the present invention can adjust the molecular weight of the waterborne acrylic polymer to achieve appropriate mechanical properties and improve the peelability of the coating film.

[0028] Preferably, the neutralizing agent is at least one of aqueous sodium hydroxide solution, triethylamine, ammonia water, and dimethylethanolamine. The present invention utilizes the acid-base neutralization property to improve the water solubility of the waterborne acrylic polymer and increase the storage stability.

[0029] Fourthly, the present invention provides a preparation method of the above-mentioned waterborne acrylic polymer, which comprises the following steps:

[0030] (1) Mix the emulsifier and 100 - 150 parts by weight of water evenly, and then sequentially add acrylic monomers, vinyl monomers, organofluorine monomers, silane coupling agents, 8 - 16 parts by weight of initiators, molecular weight regulators, and nonionic double bond monomers to obtain a pre-emulsion;

[0031] (2) Heat 300 - 450 parts by weight of water to 80 - 90 °C, add 4% - 10% of the pre-emulsion obtained in step (1) based on the total weight of the pre-emulsion and 1 - 2 parts by weight of the initiator, react and keep warm for 20 - 30 minutes to obtain a seed emulsion;

[0032] (3) Dropwise add the remaining pre-emulsion to the seed emulsion, keep the reaction temperature at 80 - 90 °C, and the dropping time is 210 - 240 minutes to obtain a polymerization emulsion;

[0033] (4) Raise the temperature of the polymerization emulsion obtained in step (3) to 85 - 95 °C, dropwise add the remaining 1 - 2 parts by weight of the initiator, keep warm for 60 - 120 minutes, after the heat preservation ends, cool down to 50 - 60 °C, add the neutralizing agent and stir, then continue to cool down to 45 - 50 °C, and filter to obtain the waterborne acrylic polymer.

[0034] The waterborne acrylic polymer prepared by the present invention through the combination of the prepared nonionic double bond monomer with acrylic monomers and vinyl monomers, and simultaneously cooperating with organofluorine monomers, silane coupling agents, initiators, and molecular weight regulators under the control of process parameters such as the above-mentioned specific reaction temperature, reaction time, and dropping time has good peelability, water resistance, scrub resistance, and adhesion

[0035] The present invention adopts a continuous dropping polymerization process. The size distribution of the latex particles is wide, the composition of the polymer does not change with time during copolymerization, and the heat and mass of the polymerization system are stable. In the preparation method of the present invention, the initiator is added in multiple times. A relatively large amount of initiator is added during the preparation of the pre-emulsion to form a relatively large number of short chains. A small amount of initiator is added again during the formation of the seed emulsion, so that the long chains in the emulsion increase during polymerization, and the particle size of the emulsion rapidly increases. Finally, the remaining initiator is added dropwise, which can make the monomers that are not completely reacted fully react, improve the conversion rate, and obtain the aqueous acrylic polymer.

[0036] Preferably, the solid content of the obtained aqueous acrylic polymer is 40-45%.

[0037] Preferably, the pH of the obtained aqueous acrylic polymer is 7-9.

[0038] Preferably, the particle size of the obtained aqueous acrylic polymer is 500-800 nanometers.

[0039] In the fifth aspect, the present invention provides the application of the above-mentioned aqueous acrylic polymer in the glass baking paint color matching process.

[0040] The above-mentioned aqueous acrylic polymer is used as an intermediate coating in the high-temperature glass baking paint color matching process. There is no oily solvent and no additives are required, and it can be directly sprayed for use. When the aqueous acrylic polymer of the present invention is applied in the high-temperature glass baking paint color matching process, it effectively prevents the penetration of the topcoat into the primer coating, maintains the peelability of the coating, ensures the color development performance of multiple topcoats, and endows the acrylic emulsion polymer with new functions.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] (1) The present invention provides a non-ionic double bond monomer. The aqueous acrylic polymer prepared by using it as a raw material has good high-temperature peelability, and at the same time has good adhesion, water resistance, and scrub resistance. By adding the non-ionic double bond monomer, on the one hand, the adhesion of the acrylic polymer is reduced and the peelability is improved; on the other hand, the particle size of the aqueous acrylic polymer is greatly increased, and the denseness of the film formation is reduced. At the same time, the added organic fluorine monomer and silane coupling agent can be oriented on the surface of the emulsion film after the latex particles are extruded into a film, thereby improving the high-temperature anti-stickiness of the emulsion film.

[0043] (2) The present invention adopts a continuous dropping polymerization process to prepare the aqueous acrylic polymer. The prepared latex particles have a wide size distribution, the polymer components do not change with time during copolymerization, and the heat and mass of the polymerization system are stable.

[0044] (3) The waterborne acrylic polymer of the present invention is applied to the high-temperature glass baking paint color overprinting process, which can effectively prevent the penetration of the topcoat into the primer coating, maintain the peelability of the coating, and ensure the color development performance of multiple topcoats. Detailed implementation manners

[0045] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the protection scope and implementation manners of the present invention are not limited thereto.

[0046] Example 1

[0047] An embodiment of the non-ionic double bond monomer of the present invention. In this embodiment, the non-ionic double bond monomer is prepared from a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-hydroxyanisole and polyethylene glycol, and their mass ratios are 0.6:8:0.2:0.6:15 in sequence; wherein the dibasic acid chain extender consists of glutaric acid, and the polyethylene glycol consists of polyethylene glycol 1000.

[0048] The preparation method of the non-ionic double bond monomer in this embodiment includes the following steps:

[0049] At normal temperature and pressure, add the formula amount of dibasic acid chain extender, p-toluenesulfonic acid, and polyethylene glycol, then heat up to 110 °C for reaction. When the acid value of the reactants is measured to be lower than 3 - 5 mg KOH / g, add methacrylic acid and p-hydroxyanisole and control the temperature at 120 °C for reaction. When the acid value is lower than 4 - 7 mg KOH / g, cool down and discharge for standby, and the non-ionic double bond monomer is obtained.

[0050] The waterborne acrylic polymer of this embodiment, by weight, its preparation raw materials include the following components: 600 parts of water, 320 parts in total of acrylic monomers and vinyl monomers, 15 parts of emulsifier, 10 parts of organofluorine monomer, 30 parts of silane coupling agent, 12 parts of initiator, 1 part of molecular weight regulator, 60 parts of the non-ionic double bond monomer prepared in this embodiment, and 15 parts of neutralizer.

[0051] Among them, the acrylic monomers and vinyl monomers consist of 120 parts of styrene, 50 parts of butyl acrylate, 15 parts of isooctyl acrylate and 135 parts of methyl methacrylate. The emulsifier consists of 15 parts of sodium vinyl sulfonate. The organofluorine monomer consists of 2 parts of hexafluorobutyl methacrylate and 8 parts of 2-perfluorohexylethyl acrylate. The silane coupling agent consists of 30 parts of vinyltrimethoxysilane. The initiator consists of 12 parts of potassium persulfate. The molecular weight regulator consists of 1 part of mercaptoethanol.

[0052] The preparation method of the waterborne acrylic polymer of this embodiment specifically includes the following steps:

[0053] (1) Pre-emulsification: at room temperature and pressure, mix the formulated amount of emulsifier and 150 parts of water in a pre-emulsification tank, stir and dissolve them thoroughly, and add the formulated amount of acrylic monomer, vinyl monomer, organic fluorine monomer, silane coupling agent, 8 parts of initiator, molecular weight regulator, and non-ionic double bond monomer in sequence to obtain a pre-emulsified liquid;

[0054] (2) Polymerization: add 400 parts of water to the bottom of the reactor, heat to 80° C., stir for 40 minutes, take 4% of the total weight of the pre-emulsion obtained in step (1) as the seed emulsion, put it into the bottom of the reactor at one time, then take 1-2 parts of the initiator, put it into the bottom of the reactor at one time, react and keep warm for 30 minutes, after the seed emulsion is formed, add the remaining pre-emulsion obtained in step (1) dropwise, the dropping time is 240 minutes, the reaction temperature is 85° C., and a polymer emulsion is obtained;

[0055] (3) Post-elimination: The polymer emulsion obtained in step (2) is heated to 90°C, and the remaining initiator is added dropwise at an accelerated rate. After the addition is completed, the mixture is kept warm for 120 minutes. After the end of the heat preservation, the mixture is cooled to 50°C, a neutralizing agent is added and stirred for 15 minutes, and then the mixture is cooled to 45°C. After filtering, a water-based acrylic polymer is obtained.

[0056] The solid content of the finally prepared aqueous acrylic polymer is 42%; the pH of the prepared aqueous acrylic polymer is 7; and the particle size of the prepared aqueous acrylic polymer is 550 nanometers.

[0057] Example 2

[0058] An embodiment of the nonionic double-bond monomer of the present invention, the nonionic double-bond monomer described in this embodiment is prepared from a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-hydroxyanisole and polyethylene glycol, and the mass ratio thereof is 0.6:8:0.2:0.6:12 respectively; wherein the dibasic acid chain extender is composed of adipic acid, and the polyethylene glycol is composed of polyethylene glycol 550.

[0059] The preparation method of the nonionic double bond monomer of this embodiment comprises the following steps:

[0060] The dibasic acid chain extender, p-toluenesulfonic acid and polyethylene glycol are added in a formula amount at room temperature and pressure, and then the temperature is raised to 90° C. for reaction. When the acid value of the reactant is measured to be lower than 3-5 mg KOH / g, methacrylic acid and p-hydroxyanisole are added and the temperature is controlled to 110° C. for reaction. When the acid value is lower than 4-7 mg KOH / g, the temperature is lowered and the material is discharged for standby use, thereby obtaining the nonionic double bond monomer.

[0061] The waterborne acrylic polymer of this example, by weight, its preparation raw materials include the following components: 450 parts of water, 300 parts in total of acrylic monomers and vinyl monomers, 20 parts of emulsifier, 20 parts of organofluorine monomers, 10 parts of silane coupling agent, 10 parts of initiator, 2 parts of molecular weight regulator, 80 parts of nonionic double bond monomers prepared in this example, and 20 parts of neutralizer.

[0062] Among them, the acrylic monomers and vinyl monomers consist of 150 parts of styrene, 40 parts of butyl acrylate, 40 parts of isooctyl acrylate, and 70 parts of isobornyl methacrylate. The emulsifier consists of 20 parts of sodium dodecyl sulfate. The organofluorine monomers consist of 20 parts of trifluoroethyl methacrylate. The silane coupling agent consists of 10 parts of vinyltrimethoxysilane. The initiator consists of 10 parts of ammonium persulfate. The molecular weight regulator consists of 2 parts of mercaptoethanol.

[0063] The preparation method of the waterborne acrylic polymer of this example specifically includes the following steps:

[0064] (1) Pre-emulsification: At normal temperature and pressure, mix the formulated amount of emulsifier and 150 parts of water in a pre-emulsification tank, stir and dissolve fully, and then sequentially add the formulated amount of acrylic monomers, vinyl monomers, organofluorine monomers, silane coupling agent, 7 parts of initiator, molecular weight regulator, and nonionic double bond monomers to obtain a pre-emulsion.

[0065] (2) Polymerization: Add 300 parts of water to the bottom of the reaction kettle, heat up to 80 °C, stir for 30 minutes, take 10% of the total weight of the pre-emulsion obtained in step (1) as the seed emulsion, and add it to the bottom of the reaction kettle at one time. Then take 2 parts of initiator and add it to the bottom of the kettle at one time, react and keep warm for 20 minutes. After the seed emulsion is formed, dropwise add the remaining pre-emulsion obtained in step (1). The dropping time is 240 minutes, and the reaction temperature is 82 °C to obtain a polymerization emulsion.

[0066] (3) Post-elimination: Heat up the polymerization emulsion obtained in step (2) to 85 °C, and accelerate the dropping of the remaining initiator. After the dropping is completed, keep warm for 120 minutes. After the heat preservation is over, cool down to 60 °C, add the neutralizer and stir for 15 minutes, then continue to cool down to 45 °C, and filter to obtain the waterborne acrylic polymer.

[0067] The solid content of the finally obtained waterborne acrylic polymer is 45%; the pH of the obtained waterborne acrylic polymer is 9; the particle size of the obtained waterborne acrylic polymer is 600 nanometers.

[0068] Example 3

[0069] An embodiment of the nonionic double-bond monomer of the present invention, the nonionic double-bond monomer described in this embodiment is prepared from a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-hydroxyanisole and polyethylene glycol, and the mass ratio thereof is 0.6:8:0.2:0.6:12; wherein the dibasic acid chain extender is composed of 1,4-cyclohexanedicarboxylic acid, and the polyethylene glycol is composed of polyethylene glycol 550.

[0070] The preparation method of the nonionic double bond monomer of this embodiment comprises the following steps:

[0071] The dibasic acid chain extender, p-toluenesulfonic acid and polyethylene glycol are added in a formula amount at room temperature and pressure, and then the temperature is raised to 110° C. for reaction. When the acid value of the reactant is measured to be lower than 3-5 mg KOH / g, methacrylic acid and p-hydroxyanisole are added and the temperature is controlled to 120° C. for reaction. When the acid value is lower than 4-7 mg KOH / g, the temperature is lowered and the material is discharged for standby use, thereby obtaining the nonionic double bond monomer.

[0072] The water-based acrylic polymer of this embodiment is prepared from the following raw materials by weight: 500 parts of water, 300 parts of acrylic monomers and vinyl monomers in total, 10 parts of emulsifiers, 10 parts of organic fluorine monomers, 20 parts of silane coupling agents, 10 parts of initiators, 1 part of molecular weight regulators, 100 parts of non-ionic double bond monomers prepared in this embodiment, and 10 parts of neutralizers.

[0073] The acrylic monomer and the vinyl monomer are composed of 100 parts of styrene, 50 parts of butyl acrylate, 40 parts of isooctyl acrylate and 110 parts of lauryl acrylate. The emulsifier is composed of 10 parts of sodium dodecyl sulfate. The organic fluorine monomer is composed of 10 parts of trifluoroethyl methacrylate. The silane coupling agent is composed of 10 parts of vinyl triethoxysilane. The initiator is composed of 10 parts of ammonium persulfate. The molecular weight regulator is composed of 1 part of n-dodecyl mercaptan.

[0074] The preparation method of the water-based acrylic acid polymer of the present embodiment specifically comprises the following steps:

[0075] (1) Pre-emulsification: at room temperature and pressure, mix the formulated amount of emulsifier and 100 parts of water in a pre-emulsification tank, stir and dissolve them thoroughly, and add the formulated amount of acrylic monomer, vinyl monomer, organic fluorine monomer, silane coupling agent, 7 parts of initiator, molecular weight regulator, and non-ionic double bond monomer in sequence to obtain a pre-emulsified liquid;

[0076] (2) Polymerization: Add 400 parts of water to the bottom of the reaction kettle, heat up to 80 °C, stir for 20 minutes, take 8% of the total weight of the pre-emulsion obtained in step (1) as the seed emulsion, and add it to the bottom of the reaction kettle at one time. Then take 2 parts of the initiator and add it to the bottom of the kettle at one time, react and keep warm for 30 minutes. After the seed emulsion is formed, add the remaining pre-emulsion obtained in step (1) dropwise. The dropping time is 210 minutes, and the reaction temperature is 80 °C to obtain a polymer emulsion;

[0077] (3) Post-elimination: Heat the polymer emulsion obtained in step (2) to 85 °C, and accelerate the dropping of the remaining initiator. After the dropping is completed, keep warm for 120 minutes. After the heat preservation is over, cool down to 60 °C, add a neutralizing agent and stir for 15 minutes, then continue to cool down to 50 °C, and filter to obtain an aqueous acrylic polymer.

[0078] The solid content of the finally obtained aqueous acrylic polymer is 40%; the pH of the obtained aqueous acrylic polymer is 7; the particle size of the obtained aqueous acrylic polymer is 740 nm.

[0079] Example 4

[0080] An example of the non-ionic double bond monomer of the present invention. The non-ionic double bond monomer in this example is prepared from a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-hydroxyanisole, and polyethylene glycol, and their mass ratios are 0.6:8:0.2:0.6:12 in sequence; among them, the dibasic acid chain extender is composed of adipic acid, and the polyethylene glycol is composed of polyethylene glycol 550.

[0081] The preparation method of the non-ionic double bond monomer in this example is the same as that in Example 2.

[0082] The aqueous acrylic polymer of this example, by weight, its preparation raw materials include the following components: 400 parts of water, 350 parts in total of acrylic monomers and vinyl monomers, 15 parts of emulsifier, 15 parts of organofluorine monomer, 20 parts of silane coupling agent, 20 parts of initiator, 5 parts of molecular weight regulator, 80 parts of the non-ionic double bond monomer prepared in this example, and 15 parts of neutralizing agent.

[0083] Among them, the acrylic monomers and vinyl monomers are composed of 150 parts of styrene, 50 parts of butyl acrylate, 50 parts of isooctyl acrylate, and 100 parts of isobornyl methacrylate. The emulsifier is composed of 15 parts of sodium dodecyl sulfate. The organofluorine monomer is composed of 15 parts of trifluoroethyl methacrylate. The silane coupling agent is composed of 20 parts of vinyltrimethoxysilane. The initiator is composed of 20 parts of ammonium persulfate. The molecular weight regulator is composed of 5 parts of mercaptoethanol.

[0084] The preparation method of the aqueous acrylic polymer in this example is the same as that in Example 2.

[0085] Example 5

[0086] An example of the non-ionic double bond monomer of the present invention. The non-ionic double bond monomer in this example is prepared from a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-hydroxyanisole and polyethylene glycol, and their mass ratios are 1:12:0.6:0.2:8 in sequence; wherein the dibasic acid chain extender is composed of adipic acid, and the polyethylene glycol is composed of polyethylene glycol 550.

[0087] The preparation method of the non-ionic double bond monomer in this example is the same as that in Example 2.

[0088] The waterborne acrylic polymer of this example, by weight, its preparation raw materials include the following components: 450 parts of water, 300 parts in total of acrylic monomers and vinyl monomers, 20 parts of emulsifier, 20 parts of organofluorine monomer, 10 parts of silane coupling agent, 10 parts of initiator, 2 parts of molecular weight regulator, 80 parts of the non-ionic double bond monomer prepared in this example, and 20 parts of neutralizer.

[0089] Among them, the acrylic monomers and vinyl monomers are composed of 150 parts of styrene, 40 parts of butyl acrylate, 40 parts of isooctyl acrylate and 70 parts of isobornyl methacrylate. The emulsifier is composed of 20 parts of sodium dodecyl sulfate. The organofluorine monomer is composed of 20 parts of trifluoroethyl methacrylate. The silane coupling agent is composed of 10 parts of vinyltrimethoxysilane. The initiator is composed of 10 parts of ammonium persulfate. The molecular weight regulator is composed of 2 parts of mercaptoethanol.

[0090] The preparation method of the waterborne acrylic polymer of this example is the same as that in Example 2.

[0091] Example 6

[0092] An example of the non-ionic double bond monomer of the present invention. The non-ionic double bond monomer in this example is composed of a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-hydroxyanisole and polyethylene glycol, and their mass ratios are 0.6:8:0.2:0.6:12 in sequence; wherein the dibasic acid chain extender is composed of adipic acid, and the polyethylene glycol is composed of polyethylene glycol 2000.

[0093] The preparation method of the non-ionic double bond monomer in this example is the same as that in Example 2.

[0094] The waterborne acrylic polymer of this example, by weight, its preparation raw materials include the following components: 450 parts of water, 300 parts in total of acrylic monomers and vinyl monomers, 20 parts of emulsifier, 20 parts of organofluorine monomer, 10 parts of silane coupling agent, 10 parts of initiator, 2 parts of molecular weight regulator, 80 parts of the non-ionic double bond monomer prepared in this example, and 20 parts of neutralizer.

[0095] Among them, the acrylic monomer and the vinyl monomer are composed of 150 parts of styrene, 40 parts of butyl acrylate, 40 parts of isooctyl acrylate, and 70 parts of isobornyl methacrylate. The emulsifier is composed of 20 parts of sodium dodecyl sulfate. The organofluorine monomer is composed of 20 parts of trifluoroethyl methacrylate. The silane coupling agent is composed of 10 parts of vinyltrimethoxysilane. The initiator is composed of 10 parts of ammonium persulfate. The molecular weight regulator is composed of 2 parts of mercaptoethanol.

[0096] The preparation method of the aqueous acrylic polymer in this example is the same as that in Example 2.

[0097] Comparative Example 1

[0098] An aqueous acrylic polymer, the raw materials for its preparation are the same as those in Example 1 except that no non-ionic double bond monomer is added, and the preparation method is the same.

[0099] Comparative Example 2

[0100] An aqueous acrylic polymer, the raw materials for its preparation are the same as those in Example 2 except that no non-ionic double bond monomer is added, and the preparation method is the same.

[0101] Comparative Example 3

[0102] An aqueous acrylic polymer, the raw materials for its preparation are the same as those in Example 3 except that no non-ionic double bond monomer is added, and the preparation method is the same.

[0103] Comparative Example 4

[0104] A comparative example of the non-ionic double bond monomer of the present invention. The non-ionic double bond monomer in this comparative example is prepared from a dibasic acid chain extender, methacrylic acid, p-toluenesulfonic acid, p-methoxyphenol, and polyethylene glycol, and their mass ratios are 6:8:0.2:0.6:12 in sequence; among them, the dibasic acid chain extender is composed of adipic acid, and the polyethylene glycol is composed of polyethylene glycol 550.

[0105] The preparation method of the non-ionic double bond monomer in this comparative example is the same as that in Example 2.

[0106] The aqueous acrylic polymer of this comparative example, calculated by weight, its preparation raw materials include the following components: 450 parts of water, 300 parts in total of acrylic monomers and vinyl monomers, 20 parts of emulsifier, 20 parts of organofluorine monomer, 10 parts of silane coupling agent, 10 parts of initiator, 2 parts of molecular weight regulator, 80 parts of the non-ionic double bond monomer prepared in this comparative example, and 20 parts of neutralizer.

[0107] The preparation method of the aqueous acrylic polymer in this comparative example is the same as that in Example 2.

[0108] Performance Test

[0109] The waterborne acrylic polymers obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were tested. Without formulating paint, they were directly spray-tested. The testing process was as follows: First, spray a glass transparent primer at room temperature, and then bake at 160 °C for 20 minutes; Second, spray the obtained waterborne acrylic polymer at 90 °C and heat up to 160 °C for heat preservation for 20 minutes, then cool down to 90 °C and spray the third red topcoat, and heat up to 160 °C for heat preservation for 20 minutes.

[0110] The properties of the waterborne acrylic polymers obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were compared, and the results are shown in Table 1.

[0111] Table 1

[0112]

[0113]

[0114] As can be seen from Table 1, for the waterborne acrylic polymers prepared in Examples 1 to 6, due to the addition of the prepared nonionic double-bond monomers, the adhesion of the acrylic polymers was reduced, the peelability was improved, and the residual rate of film peeling did not exceed 5%; at the same time, the nonionic double-bond monomers greatly increased the particle size of the acrylic polymers and reduced the denseness of film formation. When the component ratio of the nonionic double-bond monomers described in Comparative Example 4 was not within the scope of the present invention, the particle size of the prepared waterborne acrylic polymer was reduced and the peelability of the film was poor. The peelability of the products prepared in the examples was better than that of the products prepared in Comparative Examples 1 to 4, and it was suitable for the field of high-temperature glass baking paint overprinting process.

[0115] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An aqueous acrylic polymer, characterized in that, it comprises the following raw materials for preparation in parts by weight: 400 - 600 parts of water, acrylic monomers, vinyl monomers, 10 - 20 parts of emulsifier, 10 - 20 parts of organofluorine monomers, 10 - 30 parts of silane coupling agent, 10 - 20 parts of initiator, 1 - 10 parts of molecular weight regulator, 60 - 100 parts of nonionic double-bond monomers, 10 - 20 parts of neutralizing agent; the total parts by weight of the acrylic monomers and the vinyl monomers is 300 - 350 parts; the nonionic double-bond monomers are prepared from a dibasic acid chain extender, methacrylic acid, a catalyst, a polymerization inhibitor, and polyethylene glycol; the mass ratio of the dibasic acid chain extender, methacrylic acid, catalyst, polymerization inhibitor, and polyethylene glycol is dibasic acid chain extender: methacrylic acid: catalyst: polymerization inhibitor: polyethylene glycol = (0.6 - 1):(8 - 12):(0.2 - 0.6):(0.2 - 0.6):(8 - 15); the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 550, polyethylene glycol 1000, and polyethylene glycol 2000; the dibasic acid chain extender is at least one of succinic acid, glutaric acid, 1,4-cyclohexanedicarboxylic acid, and adipic acid.

2. The aqueous acrylic polymer according to claim 1, characterized in that, the mass ratio of the dibasic acid chain extender, methacrylic acid, catalyst, polymerization inhibitor, and polyethylene glycol is dibasic acid chain extender: methacrylic acid: catalyst: polymerization inhibitor: polyethylene glycol = 0.6:8:0.2:0.6:

12.

3. The aqueous acrylic polymer according to any one of claims 1 - 2, characterized in that, the catalyst is any one of p-toluenesulfonic acid and phosphoric acid; the polymerization inhibitor is any one of p-methoxyphenol and 2-sec-butyl-4,6-dinitrophenol.

4. The aqueous acrylic polymer according to claim 1, characterized in that, the preparation method of the nonionic double-bond monomers comprises the following steps: S1. Mix the dibasic acid chain extender, catalyst, and polyethylene glycol, and carry out an esterification reaction at 80 - 120 °C; S2. After the reaction in step S1 is completed, add methacrylic acid and a polymerization inhibitor, and carry out an esterification reaction at 90 - 120 °C. After the reaction is completed, cool and discharge to obtain the nonionic double-bond monomers.

5. The aqueous acrylic polymer according to claim 1, characterized in that, its raw materials for preparation include the following components in parts by weight: 450 - 600 parts of water, acrylic monomers, vinyl monomers, 15 - 20 parts of emulsifier, 10 - 15 parts of organofluorine monomers, 20 - 30 parts of silane coupling agent, 10 - 15 parts of initiator, 1 - 5 parts of molecular weight regulator, 60 - 80 parts of nonionic double-bond monomers, 15 - 20 parts of neutralizing agent; the total parts by weight of the acrylic monomers and the vinyl monomers is 300 - 320 parts.

6. The aqueous acrylic polymer according to claim 1 or 5, characterized in that, The acrylic monomer is at least one of butyl acrylate, acrylic acid, isooctyl acrylate, lauryl acrylate, isobornyl methacrylate, vinyl versatate, methyl methacrylate, and neopentyl glycol diacrylate; the vinyl monomer is styrene; the organofluorine monomer is at least one of trifluoroethyl methacrylate, hexafluorobutyl methacrylate, 2-perfluoroalkyl ethyl methacrylate, and 2-perfluorohexyl ethyl acrylate; the silane coupling agent is at least one of phenyltrimethoxysilane, vinyltriethoxysilane, dodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, and vinyltrimethoxysilane.

7. The aqueous acrylic polymer according to claim 1 or 5, characterized in that the emulsifier is at least one of sodium dodecyl sulfate, sodium vinyl sulfonate, and sodium dodecylbenzenesulfonate; the initiator is at least one of ammonium persulfate and potassium persulfate; the molecular weight regulator is at least one of n-dodecyl mercaptan and mercaptoethanol; the neutralizer is at least one of an aqueous sodium hydroxide solution, triethylamine, ammonia water, and dimethylethanolamine.

8. The method for preparing the aqueous acrylic polymer according to any one of claims 1-7, characterized in that it comprises the following steps: (1) Mix the emulsifier and 100-150 parts by weight of water evenly, and then successively add the acrylic monomer, vinyl monomer, organofluorine monomer, silane coupling agent, 8-16 parts by weight of the initiator, molecular weight regulator, and nonionic double bond monomer to obtain a pre-emulsion; (2) Heat 300-450 parts by weight of water to 80-90 °C, add 4%-10% of the pre-emulsion obtained in step (1) based on the total weight of the pre-emulsion and 1-2 parts by weight of the initiator, and react and keep warm for 20-30 minutes to obtain a seed emulsion; (3) Dropwise add the remaining pre-emulsion to the seed emulsion, keep the reaction temperature at 80-90 °C, and the dropping time is 210-240 minutes to obtain a polymerization emulsion; (4) Heat the polymerization emulsion obtained in step (3) to 85-95 °C, and dropwise add the remaining 1-2 parts by weight of the initiator, keep warm for 60-120 minutes, after the heat preservation ends, cool down to 50-60 °C, add the neutralizer and stir, and then continue to cool down to 45-50 °C, and filter to obtain the aqueous acrylic polymer.

9. The application of the aqueous acrylic polymer according to any one of claims 1-7 in the glass baking paint color matching process.

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