Preparation method of water-based acrylic emulsion with flame retardant property

Abstract

A preparation method of a water-based acrylic emulsion with flame retardant property belongs to the technical field of water-based acrylic resin for leather, and comprises the following steps: preparing a shell layer mixed solution: uniformly stirring shell layer acrylic acid and ester monomers thereof, a shell layer initiator, a solvent, a regulator and an emulsifier to obtain a shell layer monomer; preparing a core-layer mixed solution: uniformly stirring core-layer acrylic acid and ester monomers thereof, a core-layer initiator, a solvent, a regulator and an emulsifier to obtain a core-layer monomer; preparing an emulsion: adding the shell layer monomer into the core layer monomer, uniformly stirring, then adding a neutralizer for neutralization reaction, and finally adding a cross-linking agent, stirring and filtering to obtain the acrylate emulsion with a core-shell structure; wherein deionized water is adopted as the solvent; according to the invention, a flame retardant is not required to be added in the synthesis process, so that the coating has flame retardance after being dried, procedures are reduced, and the coating has the same excellent performance characteristic as the original coating.

Description

Technical Field

[0001] The invention belongs to the technical field of production of water-based acrylic resin for leather, and specifically refers to a method for preparing a water-based acrylic emulsion with flame retardant performance. Background Art

[0002] With the continuous development of economy, industrial and civil textiles are growing rapidly, but at the same time, fires caused by textiles and their coatings are also increasing, threatening human life and property safety. At present, industrially developed countries and regions have formulated corresponding textile coating flame retardant standards and test methods, and some countries have also issued relevant laws for mandatory implementation. Therefore, flame retardant treatment of textile coatings to slow down the spread of fire is very meaningful to reduce the loss of life and property.

[0003] The flame-retardant aqueous acrylic emulsion in the prior art needs to be prepared by adding a flame retardant separately, and needs to go through multiple steps of adding materials and emulsifying, heating and stirring, adding an initiator, and adding additives, so the preparation process is relatively complicated. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the embodiments of the present invention provide a water-based acrylic emulsion with flame retardant properties, which at least partially solves the above technical problems.

[0005] The technical solution adopted by the embodiment of the present invention is as follows: A water-based acrylic emulsion with flame retardant properties comprises the following steps: Preparing a shell layer mixed solution: uniformly stirring shell layer acrylic acid and its ester monomers, a shell layer initiator, a solvent, a regulator and an emulsifier to obtain a shell layer monomer; Prepare the core layer mixed solution: stir the core layer acrylic acid and its ester monomers, the core layer initiator, the solvent, the regulator and the emulsifier to obtain the core layer monomer; Prepare the emulsion: add the shell monomer to the core monomer and stir evenly, then add a neutralizer to carry out a neutralization reaction, and finally add a crosslinking agent, stir and filter to obtain an acrylic emulsion with a core-shell structure; Wherein, the solvent is deionized water.

[0006] Preferably, the shell layer acrylic acid and its ester monomers and the core layer acrylic acid and its lipid monomers both include hard monomers, soft monomers, hydroxyl-containing functional monomers and cross-linking monomers.

[0007] Preferably, the hard monomer is a mixture of one or more of methyl acrylate, ethyl acrylate, methyl methacrylate and styrene; The soft monomer is a mixture of one or more of n-butyl acrylate, isobutyl acrylate, isooctyl acrylate and lauryl acrylate; The hydroxyl functional monomer is a mixture of one or more of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride; The cross-linking monomer is a mixture of one or more of N-hydroxymethyl acrylamide, glycidyl methacrylate, diacetone acrylamide, and acetoacetoxyethyl methacrylate.

[0008] Preferably, the shell layer initiator and the core layer initiator both include an oxidation initiator and a reduction initiator.

[0009] Preferably, the oxidation initiator is a mixture of one or more of ammonium persulfate, sodium persulfate and potassium persulfate; The reduction initiator is a mixture of one or more of sodium bisulfite, SW606 reducing agent and SW640 reducing agent.

[0010] Preferably, the cross-linking agent is a mixture of diacetone acrylamide and one or more of adipic acid dihydrazide, ethylene glycol acetoacetate and methylol acrylamide.

[0011] Preferably, the regulator is a mixture of one or more of ammonium bicarbonate, sodium bicarbonate or sodium carbonate; The neutralizing agent is a mixture of one or more of triethylamine, ammonia water or ethanolamine.

[0012] Preferably, the preparation of the shell layer mixed solution is specifically: Mix 75-88% of the shell acrylate monomer, 0.2-1% of the shell initiator, 9.5-13% of deionized water, 0.3-1% of the regulator and 0.1-1% of the emulsifier; The preparation of the nuclear layer mixed solution is specifically as follows: 90-99% of core layer acrylic monomer, 0.1-1% of core layer initiator, 0.1-1% of regulator, 1-3% of deionized water and 0.1-1% of emulsifier are mixed evenly.

[0013] Preferably, the preparation of the emulsion is specifically: Deionized water is added to the shell layer mixture and stirred evenly, and then the core layer mixture is added and stirred evenly, and then a neutralizer is added to carry out a neutralization reaction, and finally 2-5% of a cross-linking agent is added and filtered to obtain an acrylic emulsion with a core-shell structure.

[0014] On the other hand, the present invention also provides a method for preparing a water-based acrylic emulsion having flame retardant properties, comprising the following steps: Put core layer acrylic acid and lipid monomers, emulsifier, regulator and deionized water into a pre-emulsification kettle and stir evenly to obtain core layer monomers; Put shell acrylic acid and lipid monomers, emulsifier, deionized water and regulator into a pre-emulsification kettle and stir evenly to obtain shell monomer; The shell monomer is added into a reaction kettle containing deionized water, and then the shell initiator is added and stirred evenly, and then the reaction is kept warm until the shell structure resin is completely obtained for use; The shell layer structure resin is added to the core layer monomer and stirred evenly, and the core layer initiator is added dropwise to keep the temperature to react completely; After adding a neutralizing agent and stirring evenly, adding a cross-linking agent and stirring evenly, filtering, and obtaining an acrylic emulsion with a core-shell structure.

[0015] The beneficial effects achieved by the present invention using the above structure are as follows: The water-based acrylic resin prepared by the method of the present invention selects shell layer and core layer monomers with flame retardant properties, and has good flame retardant properties without adding flame retardants. After testing, its limiting oxygen index value reaches 21.6%, which is 28% higher than the limiting oxygen index value of the water-based acrylic composite resin without adding flame retardants, and has good flame retardant properties.

[0016] The preparation method of the invention adopts a one-step emulsion polymerization method and a swelling polymerization method to prepare the acrylic ester resin with a core-shell structure, thereby reducing the preparation procedures. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] A water-based acrylic emulsion with flame retardant properties comprises the following steps: Preparing a shell layer mixed solution: uniformly stirring shell layer acrylic acid and its ester monomers, a shell layer initiator, a solvent, a regulator and an emulsifier to obtain a shell layer monomer; Prepare the core layer mixed solution: stir the core layer acrylic acid and its ester monomers, the core layer initiator, the solvent, the regulator and the emulsifier to obtain the core layer monomer; Prepare the emulsion: add the shell monomer to the core monomer and stir evenly, then add a neutralizer to carry out a neutralization reaction, and finally add a crosslinking agent, stir and filter to obtain an acrylic emulsion with a core-shell structure; Wherein, the solvent is deionized water.

[0020] Shell layer and core layer monomers with flame retardant properties are selected so that the prepared water-based acrylic emulsion has good flame retardant properties without adding flame retardants.

[0021] In a further implementation of this embodiment, the shell layer acrylic acid and its ester monomers and the core layer acrylic acid and its lipid monomers both include hard monomers, soft monomers, hydroxyl-containing functional monomers and cross-linking monomers.

[0022] In a further implementation of this embodiment, the hard monomer is a mixture of one or more of methyl acrylate, ethyl acrylate, methyl methacrylate, and styrene; The soft monomer is a mixture of one or more of n-butyl acrylate, isobutyl acrylate, isooctyl acrylate and lauryl acrylate; The hydroxyl functional monomer is a mixture of one or more of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride; The cross-linking monomer is a mixture of one or more of N-hydroxymethyl acrylamide, glycidyl methacrylate, diacetone acrylamide, and acetoacetoxyethyl methacrylate.

[0023] The combined use of hard monomers, soft monomers, hydroxyl-containing functional monomers and cross-linking monomers can significantly improve the performance of the final product. By adjusting the ratio of hard monomers to soft monomers, the material can be given appropriate flexibility and resilience while ensuring sufficient hardness, and is suitable for a variety of complex processing conditions. The active sites provided by hydroxyl-containing functional monomers help strengthen the chemical bond between the polymer and the substrate, ensuring that the coating is firmly attached to various surfaces and performs well even in harsh environments. The three-dimensional network structure constructed by the cross-linking monomer effectively blocks the influence of external factors (such as ultraviolet rays, moisture, oxygen, etc.) on the internal part of the material, reduces the occurrence of aging, and maintains long-term stable physical and chemical properties.

[0024] In a further embodiment of this example, the shell layer initiator and the core layer initiator both include an oxidation initiator and a reduction initiator.

[0025] In a further embodiment of this example, the oxidation initiator is a mixture of one or more of ammonium persulfate, sodium persulfate and potassium persulfate; The reduction initiator is a mixture of one or more of sodium bisulfite, SW606 reducing agent and SW640 reducing agent.

[0026] In a further implementation of this example, the cross-linking agent is a mixture of diacetone acrylamide and one or more of adipic acid dihydrazide, ethylene glycol acetoacetate and methylol acrylamide.

[0027] In a further embodiment of this example, the regulator is a mixture of one or more of ammonium bicarbonate, sodium bicarbonate or sodium carbonate; The neutralizing agent is a mixture of one or more of triethylamine, ammonia water or ethanolamine.

[0028] In a further implementation of this embodiment, the preparation of the shell layer mixture is specifically: Mix 75-88% of the shell acrylate monomer, 0.2-1% of the shell initiator, 9.5-13% of deionized water, 0.3-1% of the regulator and 0.1-1% of the emulsifier; The preparation of the nuclear layer mixed solution is specifically as follows: 90-99% of core layer acrylic monomer, 0.1-1% of core layer initiator, 0.1-1% of regulator, 1-3% of deionized water and 0.1-1% of emulsifier are mixed evenly.

[0029] In a further embodiment of this example, the preparation of the emulsion is specifically: Deionized water is added to the shell layer mixture and stirred evenly, and then the core layer mixture is added and stirred evenly, and then a neutralizer is added to carry out a neutralization reaction, and finally 2-5% of a cross-linking agent is added and filtered to obtain an acrylic emulsion with a core-shell structure.

[0030] In another embodiment, a method for preparing a water-based acrylic emulsion having flame retardant properties comprises the following steps: Put core layer acrylic acid and lipid monomers, emulsifier, regulator and deionized water into a pre-emulsification kettle and stir evenly to obtain core layer monomers; Put shell acrylic acid and lipid monomers, emulsifier, deionized water and regulator into a pre-emulsification kettle and stir evenly to obtain shell monomers; The shell monomer is added into a reaction kettle containing deionized water, and then the shell initiator is added and stirred evenly, and then the reaction is kept warm until the shell structure resin is completely obtained for use; The shell layer structure resin is added to the core layer monomer and stirred evenly, and the core layer initiator is added dropwise to keep the temperature to react completely; After adding a neutralizing agent and stirring evenly, adding a cross-linking agent and stirring evenly, filtering, and obtaining an acrylic emulsion with a core-shell structure.

[0031] It should be noted that in the core-shell structured acrylic ester dispersion, the glass transition temperature of the core layer is -25 to -60°C, and the glass transition temperature of the shell layer is 20 to 60°C. The effective content of the product is 40±2%, and the pH is 7-8.

[0032] Example 1 Preparation of core layer monomer: 152.45 g of butyl acrylate, 9.05 g of ethyl acrylate, 3.5 g of acrylic acid, and 1.02 g of stearic acid (i.e., emulsifier) ​​were added into a pre-emulsification kettle, stirred evenly for use; the core layer monomer was obtained; Preparation of core layer initiator: ammonium persulfate 1.1 g, concentration 3.6%; sodium bisulfite: 0.8 g, concentration 3%.

[0033] Preparation of shell monomer: 60g of deionized water, 1.36g of sodium dodecyl sulfate (i.e., emulsifier), 10g of polyacrylamide 100 (i.e., functional monomer with flame retardant properties), 88.84g of methyl methacrylate, 47.5g of methyl acrylate, 5.5g of acrylic acid and 5g of diacetone acrylamide were put into a pre-emulsification kettle, stirred evenly for standby use; shell monomer was obtained; Preparation of shell initiator: ammonium persulfate: 0.8 g, concentration 3.6%; sodium bisulfite: 0.6 g, concentration 3%.

[0034] Add 300g of deionized water to the reactor, cool down to 10°C while stirring, then add the shell mixed solution at one time, then add sodium persulfate and sodium bisulfite solution initiators to the reactor at one time, wait for the exothermic temperature to drop, heat up to 60°C, and keep warm for 60 minutes to obtain a shell structure resin; Add the core layer mixed solution to the shell structure resin, swell and stir for 30 minutes, and simultaneously drop ammonium persulfate and sodium bisulfite solution, maintain the temperature at 60°C, continue to keep warm for 60 minutes after the dropwise addition is completed, cool down, add a certain amount of ammonia water, stir evenly, add 3g of adipic acid dihydrazide, filter, and obtain an acrylic ester emulsion with a core-shell structure, which is the aqueous acrylic dispersion, with a solid content of 40±2% and a pH of 7-8.

[0035] The flame retardant waterborne acrylic resin obtained above was tested and its limiting oxygen index value reached 22.7%, which was 33% higher than that of the waterborne acrylic composite resin without adding flame retardant, and had good flame retardant performance.

[0036] Example 2 Preparation of core layer monomer: 125 g of butyl acrylate, 34 g of ethyl acrylate, 3.5 g of acrylic acid, and 1.02 g of stearic acid are put into a pre-emulsification kettle, stirred evenly for standby use; obtain core layer monomer; Preparation of core layer initiator: ammonium persulfate: 0.7 g, concentration 3.6%; sodium bisulfite: 0.6 g, concentration 3%.

[0037] Preparation of shell monomer: 60g of deionized water, 1.36g of sodium dodecyl sulfate, 20g of polyacrylamide 100, 80g of methyl methacrylate, 59.5g of methyl acrylate, 5.5g of acrylic acid and 5g of diacetone acrylamide were put into a pre-emulsification kettle, stirred evenly for standby use; shell monomer was obtained; Preparation of shell initiator: ammonium persulfate: 0.8 g, concentration 3.6%; sodium bisulfite: 0.6 g, concentration 3%.

[0038] Add 300g of deionized water to the reactor, cool down to 15°C while stirring, then add the shell mixed solution at one time, then add sodium persulfate and sodium bisulfite solution initiators to the reactor at one time, wait for the exothermic temperature to drop, heat up to 60°C, and keep warm for 60 minutes to obtain a shell structure resin; Add the core layer mixed solution to the shell structure resin, swell and stir for 30 minutes, and simultaneously drop ammonium persulfate and sodium bisulfite solution, maintain the temperature at 60°C, continue to keep warm for 60 minutes after the dropwise addition is completed, cool down, add a certain amount of ammonia water, stir evenly, add 3g of adipic acid dihydrazide, filter, and obtain an acrylic ester emulsion with a core-shell structure, which is the aqueous acrylic dispersion, with a solid content of 40±2% and a pH of 7-8.

[0039] The flame retardant water-based acrylic composite resin obtained above was tested and its limiting oxygen index value reached 23.7%, which was 35% higher than that of the water-based acrylic composite resin without adding flame retardant, and had good flame retardant performance.

[0040] Example 3 Preparation of core layer monomer: 80.45 g of butyl acrylate, 80 g of isooctyl acrylate, 3.5 g of acrylic acid, and 1.03 g of stearic acid are put into a pre-emulsification kettle, stirred evenly for standby use; obtain core layer monomer; Preparation of nuclear layer initiator: 1.1 g of ammonium persulfate, concentration 3.6%; 0.8 g of sodium bisulfite, concentration 3%.

[0041] Preparation of shell monomer: 60g of deionized water, 1.36g of sodium dodecyl sulfate, 10g of polyacrylamide 100, 88.84g of methyl methacrylate, 47.5g of methyl acrylate, 5.5g of acrylic acid and 5g of diacetone acrylamide were put into a pre-emulsification kettle, stirred evenly for standby use; shell monomer was obtained; Preparation of shell initiator: ammonium persulfate: 0.8 g, concentration 3.6%; sodium bisulfite: 0.6 g, concentration 3%.

[0042] Add 300g of deionized water to the reactor, cool down to 10°C while stirring, then add the shell mixed solution at one time, then add sodium persulfate and sodium bisulfite solution initiators to the reactor at one time, wait for the exothermic temperature to drop, heat up to 60°C, and keep warm for 60 minutes to obtain a shell structure resin; Add the core layer mixed solution to the shell structure resin, swell and stir for 30 minutes, and simultaneously drop ammonium persulfate and sodium bisulfite solution, maintain the temperature at 60°C, continue to keep warm for 60 minutes after the dropwise addition is completed, cool down, add a certain amount of ammonia water, stir evenly, add 3g of adipic acid dihydrazide, filter, and obtain an acrylic ester emulsion with a core-shell structure, which is the aqueous acrylic dispersion, with a solid content of 40±2% and a pH of 7-8.

[0043] The flame retardant waterborne acrylic resin obtained above was tested and its limiting oxygen index value reached 21.6%, which was 28% higher than that of the waterborne acrylic composite resin without adding flame retardant, and had good flame retardant performance.

[0044] The numerical values ​​of the above embodiments are based on experimental values ​​for the convenience of description. In actual industrial production, the same effect can be obtained by producing according to the proportions of the above embodiments.

[0045] The above contents are only basic descriptions of the concept of the present invention, and any equivalent changes made according to the technical solution of the present invention shall fall within the protection scope of the present invention.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0047] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

[0048] The present invention and its implementation methods are described above, and such description is not restrictive, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the creative purpose of the embodiments of the present invention, they can design a structure and embodiment similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a flame retardant aqueous acrylic emulsion, characterized in that: The following steps are involved: Preparing a shell layer mixed solution: uniformly stirring shell layer acrylic acid and its ester monomers, a shell layer initiator, a solvent, a regulator and an emulsifier to obtain a shell layer monomer; Prepare the core layer mixed solution: stir the core layer acrylic acid and its ester monomers, the core layer initiator, the solvent, the regulator and the emulsifier to obtain the core layer monomer; Prepare the emulsion: add the shell monomer to the core monomer and stir evenly, then add a neutralizer to carry out a neutralization reaction, and finally add a crosslinking agent, stir and filter to obtain an acrylic emulsion with a core-shell structure; Wherein, the solvent is deionized water.

2. The method for preparing the water-based acrylic emulsion with flame retardancy according to claim 1, characterized in that: The shell layer acrylic acid and its ester monomers and the core layer acrylic acid and its lipid monomers all include hard monomers, soft monomers, hydroxyl-containing functional monomers and cross-linking monomers.

3. The method for preparing the flame retardant aqueous acrylic emulsion according to claim 2, characterized in that: The hard monomer is a mixture of one or more of methyl acrylate, ethyl acrylate, methyl methacrylate and styrene; The soft monomer is a mixture of one or more of n-butyl acrylate, isobutyl acrylate, isooctyl acrylate and lauryl acrylate; The hydroxyl functional monomer is a mixture of one or more of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride; The cross-linking monomer is a mixture of one or more of N-hydroxymethyl acrylamide, glycidyl methacrylate, diacetone acrylamide, and acetoacetoxyethyl methacrylate.

4. The method for preparing the flame retardant aqueous acrylic emulsion according to claim 1, characterized in that: The shell layer initiator and the core layer initiator both include an oxidation initiator and a reduction initiator.

5. The method for preparing the flame retardant aqueous acrylic emulsion according to claim 4, characterized in that: The oxidation initiator is a mixture of one or more of ammonium persulfate, sodium persulfate and potassium persulfate; The reduction initiator is a mixture of one or more of sodium bisulfite, SW606 reducing agent and SW640 reducing agent.

6. The method for preparing the flame retardant aqueous acrylic emulsion according to claim 1, characterized in that: The cross-linking agent is a mixture of one or more of diacetone acrylamide, adipic acid dihydrazide, ethylene glycol acetoacetate methacrylate, and hydroxymethyl acrylamide.

7. The method for preparing the flame retardant aqueous acrylic emulsion according to claim 1, characterized in that: The regulator is a mixture of one or more of ammonium bicarbonate, sodium bicarbonate or sodium carbonate; The neutralizing agent is a mixture of one or more of triethylamine, ammonia water or ethanolamine.

8. The method for preparing the flame retardant aqueous acrylic emulsion according to claim 1, characterized in that: The preparation of the shell layer mixed solution is specifically as follows: Mix 75-88% of the shell acrylate monomer, 0.2-1% of the shell initiator, 9.5-13% of deionized water, 0.3-1% of the regulator and 0.1-1% of the emulsifier; The preparation of the nuclear layer mixed solution is specifically as follows: 90-99% of core layer acrylic monomer, 0.1-1% of core layer initiator, 0.1-1% of regulator, 1-3% of deionized water and 0.1-1% of emulsifier are mixed evenly.

9. The flame retardant aqueous acrylic emulsion according to claim 1, characterized in that: The preparation of the emulsion is specifically as follows: Deionized water is added to the shell layer mixture and stirred evenly, and then the core layer mixture is added and stirred evenly, and then a neutralizer is added to carry out a neutralization reaction, and finally 2-5% of a cross-linking agent is added and filtered to obtain an acrylic emulsion with a core-shell structure.

10. A method for preparing a water-based acrylic emulsion having flame retardant properties, characterized in that: The following steps are involved: Put core layer acrylic acid and lipid monomers, emulsifier, regulator and deionized water into a pre-emulsification kettle and stir evenly to obtain core layer monomers; Put shell acrylic acid and lipid monomers, emulsifier, deionized water and regulator into a pre-emulsification kettle and stir evenly to obtain shell monomers; The shell monomer is added into a reaction kettle containing deionized water, and then the shell initiator is added and stirred evenly, and then the reaction is kept warm until the shell structure resin is completely obtained for use; The shell layer structure resin is added to the core layer monomer and stirred evenly, and the core layer initiator is added dropwise to keep the temperature to react completely; After adding a neutralizing agent and stirring evenly, adding a cross-linking agent and stirring evenly, filtering, and obtaining an acrylic emulsion with a core-shell structure.