A method and application for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry reaction.

Abstract

The present invention aims to provide a method and application for preparing interfacially cross-linked core-shell polyvinyl chloride (PVC) copolymer resin aqueous emulsion via click chemistry. First, the PVC aqueous emulsion is heated to 40–95°C and held at that temperature for 30–90 minutes. Then, a multi-thiol monomer is added and reacted for 10–120 minutes, allowing the PVC latex particles to undergo a click chemistry reaction with the multi-thiol monomer. Next, an alkenyl monomer is added dropwise, and the interfacially cross-linked core-shell PVC copolymer resin aqueous emulsion is obtained through emulsion polymerization. This invention introduces dithiol or multithiol monomers into the PVC copolymer resin, achieving core-shell interfacial cross-linking through thiol-alkene click chemistry, fully utilizing the synergistic effect of the core and shell polymers. The resulting aqueous emulsion, after curing, exhibits excellent water and alkali resistance. This method is simple, low-carbon, and environmentally friendly, with broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a method and application for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry reaction. Background Technology

[0002] Polyvinyl chloride (PVC) possesses excellent barrier and anti-corrosion properties, effectively isolating water and oxygen. However, due to the inherent structural characteristics of the PVC molecule, homopolymerized PVC exhibits poor film-forming properties, thermal stability, weather resistance, and weak adhesion, severely limiting its application in water-based coatings. Therefore, in practical applications, alkenyl monomers are typically introduced to improve PVC performance. Generally, the reactivity ratios between vinyl chloride and alkenyl monomer-containing free radical polymers differ significantly, and the production process of PVC copolymers is complex and energy-intensive. While designing the latex structure to construct a core-shell structure using a soft-encapsulated-hard approach can effectively improve PVC film-forming properties, the interfacial forces between the PVC core and shell polymers are weak, making it difficult to fully utilize the complementary effects of PVC and alkenyl polymers. This results in low overall film performance, severely limiting the application of PVC copolymer resin water-based latexes in coatings and other fields.

[0003] Interfacial forces are the result of the combined effects of mechanical forces, van der Waals forces, hydrogen bonds, chemical bonds, electrostatic forces, and adsorption. Studies have shown that interfacial bonding dominated by covalent bonds exhibits superior interfacial interactions. A search reveals that current reports on interfacial reactions mainly focus on the interfacial forces between inorganic fillers and organic matrices (e.g., CN110437370A and CN102676023B), while studies on the interfacial forces between the core and shell of core-shell polymers are scarce.

[0004] Click chemistry has been widely used in the synthesis of functional polymers, preparation of topological polymers, and surface modification due to its many advantages, such as simple operation, mild reaction conditions, wide range of applications, strong selectivity, and insensitivity of products to oxygen and water.

[0005] Chinese patent CN108676164B discloses a method for preparing click chemistry interfacial reaction polymer hybrid hollow microspheres. The method involves forming an oil phase from a blend of mercapto-containing monomers, alkenyl-containing monomers, a non-reactive solvent, a stabilizer, and nanoparticles, and an aqueous phase from an emulsifier and deionized water. A click reaction of the mercapto-alkenyl group is initiated at the oil-water interface of the monomer droplets, followed by polymerization to obtain the polymer hybrid hollow microspheres. This method utilizes click chemistry interfacial reactions to achieve effective coating of nanoparticles, falling within the research scope of inorganic-organic interfacial forces. However, there are currently no research reports or patent documents on applying click chemistry reactions to improve the interfacial interactions of core-shell structured polymers. Summary of the Invention

[0006] The purpose of this invention is to provide a method and application for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer resin aqueous latex via click chemistry. By using click chemistry, the polyvinyl chloride core and shell polymer are covalently bonded, which can fully utilize the complementary properties of polyvinyl chloride and shell polymer, and optimize the overall performance of polyvinyl chloride copolymer resin aqueous latex film.

[0007] To achieve the above-mentioned technical objectives and related technical objectives, this invention provides a method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry reaction, comprising the following steps:

[0008] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex is added to the reactor, stirred and heated to 40-95°C, kept warm for 30-90 minutes, and then a monomer containing polythiol groups is added to the reactor. The reaction is carried out at 40-95°C for 10-120 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0009] (2) Add deionized water, emulsifier, and alkenyl-containing monomer to a stirrer and stir at high speed at 25°C for 10 to 60 minutes to obtain a pre-emulsion of shell polymer;

[0010] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, and an initiator is added dropwise at the same time. The dropwise addition time of the pre-emulsion is 0.5 to 5 hours, the temperature during the polymerization process is 40 to 85°C, and after the dropwise addition is completed, the reaction is continued to be kept at the temperature for 0.5 to 3 hours.

[0011] (4) Cool down to 30-50℃, add the initiator aqueous solution, keep warm for 0.5-3 hours, then cool down to room temperature, adjust the pH value to 6-10 using a pH adjuster, filter with 100-200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0012] In one example of the method for preparing interfacially crosslinked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the mass of the monomer containing polythiol groups is 1-20% of the mass of the polyvinyl chloride aqueous latex, the mass of the monomer containing alkenyl groups is 20-60% of the mass of the polyvinyl chloride aqueous latex, the mass of the deionized water is 30-50% of the mass of the alkenyl groups, the mass of the emulsifier is 2-4% of the mass of the alkenyl groups, the mass of the initiator is 0.5-3% of the mass of the alkenyl groups, the mass of the post-initiator aqueous solution is 0.5-3% of the mass of the alkenyl groups, the mass of the pH adjuster is 0.3-0.5% of the mass of the alkenyl groups, and the polyvinyl chloride content in the polyvinyl chloride aqueous latex is 35-45%.

[0013] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the monomer containing polythiol is one or more of butanediol bis(thioglycolic acid ester), bis(thioglycolic acid) ethylene glycol ester, bis(thioethyl) ether, butanedithiol, pentanedithiol, hexanedithiol, heptamethnitrile, trimethylolpropane tris(3-mercaptopropionic acid), and trimethylolpropane tris(thioglycolic acid).

[0014] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the alkenyl-containing monomer includes one or more of the following: hard alkenyl monomers, soft alkenyl monomers, and alkenyl monomers containing hydroxyl, carboxyl, amide, or epoxy groups.

[0015] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the olefinic hard monomer is one or more of styrene, methyl methacrylate, and acrylonitrile.

[0016] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the olefinic soft monomer is one or more of butyl acrylate, ethyl acrylate, hexyl acrylate, and 2-ethylhexyl acrylate.

[0017] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the olefin monomer containing hydroxyl, carboxyl, amide or epoxy groups is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, methacrylic acid, acrylamide, and glycidyl methacrylate.

[0018] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex by click chemical reaction of the present invention, the emulsifier is one or more of sodium dodecylbenzenesulfonate, polyoxyethylene octylphenol ether-10, fatty alcohol polyoxyethylene ether, and sodium allyloxyhydroxypropanesulfonate.

[0019] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the initiator is one or more of sodium persulfate, sodium persulfate-sodium bisulfite, benzoyl peroxide, azobisisobutyronitrile, tert-butyl hydroperoxide, and hydrogen peroxide.

[0020] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the aqueous initiator solution is an aqueous solution of hydrogen peroxide or an aqueous solution of tert-butyl hydrogen peroxide.

[0021] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex by click chemical reaction according to the present invention, the pH adjuster is triethylamine, triethanolamine or ammonia.

[0022] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the stirring speed of the stirrer is 200-1500 rpm and the stirring time is 10-60 minutes.

[0023] The present invention also provides a method for preparing a core-shell polyvinyl chloride copolymer water latex by preparing an interfacially cross-linked core-shell polyvinyl chloride copolymer water latex through a click chemical reaction, wherein the polyvinyl chloride core and the shell copolymer are cross-linked by covalent bonds generated by a click chemical reaction.

[0024] This invention also protects the application of the core-shell type polyvinyl chloride copolymer resin water emulsion prepared by click chemical reaction in coatings.

[0025] This invention relates to a method and application for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex via click chemistry. The method involves heating the polyvinyl chloride latex to a certain temperature, causing chlorine atoms to detach from the unstable structural units of the polyvinyl chloride, generating free radicals in the polyvinyl chloride macromolecular chain. These free radicals then react with the thiol groups in the added multi-thiol monomers to undergo a thiol-alkene click chemistry reaction, thus grafting thiol functional groups onto the surface of the polyvinyl chloride particles. Subsequently, when alkenyl monomers are added, the thiol groups on the surface of the polyvinyl chloride seed particles react with the double bonds of the polymerizable monomers under the action of an initiator to generate a thiol-alkene click reaction, thereby achieving bonding between the polyvinyl chloride seed and the shell polymer.

[0026] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0027] (1) This invention applies click chemistry to strengthen the core-shell interface of core-shell structured polymer particles, which increases the bonding probability between polyvinyl chloride seeds and alkenyl polymers, enhances the bonding force between the core and shell, and fully leverages the respective performance advantages of the core and shell polymers.

[0028] (2) The preparation method provided by the present invention is simple, low-carbon, environmentally friendly and easy to produce, and can be used to prepare a variety of core-shell structure copolymers.

[0029] (3) The beneficial effects of the present invention also include promoting the technological progress and product optimization and upgrading of core-shell structured latex, resulting in significant economic benefits. Attached Figure Description

[0030] Figure 1 is a reaction flow diagram of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex by click chemical reaction according to the present invention. Detailed Implementation

[0031] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific implementation schemes and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0032] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of the invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to the methods, devices, and materials in the embodiments of the present invention.

[0033] This invention provides a method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry, comprising the following steps:

[0034] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex is added to the reactor, stirred and heated to 40-95°C, kept warm for 30-90 minutes, and then a monomer containing polythiol groups is added to the reactor. The reaction is carried out at 40-95°C for 10-120 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0035] (2) Add deionized water, emulsifier, and alkenyl-containing monomer to a stirrer and stir at high speed at 25°C for 10 to 60 minutes to obtain a pre-emulsion of shell polymer;

[0036] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, and an initiator is added dropwise at the same time. The dropwise addition time of the pre-emulsion is 0.5 to 5 hours, the temperature during the polymerization process is 40 to 85°C, and after the dropwise addition is completed, the reaction is continued to be kept at the temperature for 0.5 to 3 hours.

[0037] (4) Cool down to 30-50℃, add the initiator aqueous solution, keep warm for 0.5-3 hours, then cool down to room temperature, adjust the pH value to 6-10 using a pH adjuster, filter with 100-200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0038] In one example of the method for preparing interfacially crosslinked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the mass of the monomer containing polythiol groups is 1-20% of the mass of the polyvinyl chloride aqueous latex, the mass of the monomer containing alkenyl groups is 20-60% of the mass of the polyvinyl chloride aqueous latex, the mass of the deionized water is 30-50% of the mass of the alkenyl groups, the mass of the emulsifier is 2-4% of the mass of the alkenyl groups, the mass of the initiator is 0.5-3% of the mass of the alkenyl groups, the mass of the post-initiator aqueous solution is 0.5-3% of the mass of the alkenyl groups, the mass of the pH adjuster is 0.3-0.5% of the mass of the alkenyl groups, and the polyvinyl chloride content in the polyvinyl chloride aqueous latex is 35-45%.

[0039] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the monomer containing polythiol is one or more of butanediol bis(thioglycolic acid ester), bis(thioglycolic acid) ethylene glycol ester, bis(thioethyl) ether, butanedithiol, pentanedithiol, hexanedithiol, heptamethnitrile, trimethylolpropane tris(3-mercaptopropionic acid), and trimethylolpropane tris(thioglycolic acid).

[0040] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the alkenyl-containing monomer includes one or more of the following: hard alkenyl monomers, soft alkenyl monomers, and alkenyl monomers containing hydroxyl, carboxyl, amide, or epoxy groups.

[0041] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the olefinic hard monomer is one or more of styrene, methyl methacrylate, and acrylonitrile.

[0042] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the olefinic soft monomer is one or more of butyl acrylate, ethyl acrylate, hexyl acrylate, and 2-ethylhexyl acrylate.

[0043] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the olefin monomer containing hydroxyl, carboxyl, amide or epoxy groups is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, methacrylic acid, acrylamide, and glycidyl methacrylate.

[0044] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex by click chemical reaction of the present invention, the emulsifier is one or more of sodium dodecylbenzenesulfonate, polyoxyethylene octylphenol ether-10, fatty alcohol polyoxyethylene ether, and sodium allyloxyhydroxypropanesulfonate.

[0045] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction of the present invention, the initiator is one or more of sodium persulfate, sodium persulfate-sodium bisulfite, benzoyl peroxide, azobisisobutyronitrile, tert-butyl hydroperoxide, and hydrogen peroxide.

[0046] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the aqueous initiator solution is an aqueous solution of hydrogen peroxide or an aqueous solution of tert-butyl hydrogen peroxide.

[0047] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex by click chemical reaction according to the present invention, the pH adjuster is triethylamine, triethanolamine or ammonia.

[0048] In one example of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer latex by click chemical reaction according to the present invention, the stirring speed of the stirrer is 200-1500 rpm and the stirring time is 10-60 minutes.

[0049] Please refer to Figure 1, which is a reaction flow diagram of the method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex by click chemical reaction according to the present invention.

[0050] When the polyvinyl chloride (PVC) aqueous latex is heated, chlorine atoms on the unstable structural units of PVC are released, generating free radicals on the PVC macromolecular chain. These free radicals then undergo a thiol-alkene click chemical reaction with the thiol groups in the multi-thiol-containing monomer, resulting in the grafting of thiol functional groups onto the surface of the PVC seed particles. Upon addition of the alkenyl-containing monomer, under the action of the initiator, the thiol groups on the surface of the PVC seed particles undergo a thiol-alkene click chemical reaction with the double bonds in the alkenyl-containing monomer, thereby achieving bonding between the PVC seed and the shell polymer. The predominantly covalent interfacial bonding exhibits superior interfacial interaction forces, enhancing the binding force between the PVC seed and the shell polymer, fully leveraging the complementary properties of PVC and the shell polymer, and improving the overall performance of the PVC copolymer resin aqueous latex film.

[0051] The present invention also provides a method for preparing a core-shell polyvinyl chloride copolymer water latex by preparing an interfacially cross-linked core-shell polyvinyl chloride copolymer water latex through a click chemical reaction, wherein the polyvinyl chloride core and the shell copolymer are cross-linked by covalent bonds generated by a click chemical reaction.

[0052] This invention also protects the application of the core-shell type polyvinyl chloride copolymer resin water emulsion prepared by click chemical reaction in coatings.

[0053] The polyvinyl chloride water-based latex used in the following examples is prepared by emulsion polymerization or suspension polymerization.

[0054] Example 1

[0055] Weigh the following components by mass:

[0056] 7kg of polyvinyl chloride water latex

[0057] 0.1 kg of trimethylolpropane tris(3-mercaptopropionic acid) ester

[0058] 1.8kg of deionized water

[0059] Sodium dodecylbenzenesulfonate 0.03 kg

[0060] Fatty alcohol polyoxyethylene ether 0.06kg

[0061] Sodium allyl hydroxypropanesulfonate 0.03 kg

[0062] Sodium persulfate 0.015 kg

[0063] Hydroxyethyl acrylate 0.15kg

[0064] 1.2 kg of styrene

[0065] 2kg of butyl acrylate

[0066] 0.2 kg of methyl methacrylate

[0067] 0.15 kg of methacrylic acid

[0068] Acrylamide 0.1kg

[0069] Sodium bisulfite 0.008 kg

[0070] 0.04 kg of hydrogen peroxide aqueous solution

[0071] 0.015 kg of ammonia water

[0072] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex was added to the reactor, stirred and heated to 85°C, and kept warm for 30 minutes. Then, trimethylolpropane tris(3-mercaptopropionic acid) ester was added to the reactor and reacted at 85°C for 30 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0073] (2) Add deionized water, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, sodium allyl hydroxypropanesulfonate, hydroxyethyl acrylate, styrene, butyl acrylate, methyl methacrylate, methacrylic acid and acrylamide to a stirrer and stir at high speed for 30 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0074] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, while an aqueous solution of sodium persulfate and sodium bisulfite is added dropwise. The dropwise addition time of the pre-emulsion is 2 hours, the temperature during the polymerization process is 65°C, and after the dropwise addition is completed, the reaction is continued at the temperature for 1 hour.

[0075] (4) Cool down to 40°C, add hydrogen peroxide solution, keep warm for 1 hour, then cool down to room temperature, adjust the pH value to 7-8 with ammonia, filter with 200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0076] Example 2

[0077] Weigh the following components by mass:

[0078] 7kg of polyvinyl chloride water latex

[0079] 0.15 kg of trimethylolpropane tris(3-mercaptopropionic acid) ester

[0080] 1.8kg of deionized water

[0081] Sodium dodecylbenzenesulfonate 0.03 kg

[0082] Fatty alcohol polyoxyethylene ether 0.06kg

[0083] Sodium allyl hydroxypropanesulfonate 0.03 kg

[0084] Sodium persulfate 0.015 kg

[0085] Hydroxyethyl acrylate 0.15kg

[0086] 1.2 kg of styrene

[0087] 2kg of butyl acrylate

[0088] 0.2 kg of methyl methacrylate

[0089] 0.15 kg of methacrylic acid

[0090] Acrylamide 0.1kg

[0091] Sodium bisulfite 0.008 kg

[0092] 0.04 kg of hydrogen peroxide aqueous solution

[0093] 0.015 kg of ammonia water

[0094] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex was added to the reactor and stirred and heated to 65°C for 30 minutes. Then, trimethylolpropane tris(3-mercaptopropionic acid) ester was added to the reactor and reacted at 65°C for 30 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0095] (2) Add deionized water, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, sodium allyl hydroxypropanesulfonate, hydroxyethyl acrylate, styrene, butyl acrylate, methyl methacrylate, methacrylic acid and acrylamide to a stirrer and stir at high speed for 30 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0096] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, while an aqueous solution of sodium persulfate and sodium bisulfite is added dropwise. The dropwise addition time of the pre-emulsion is 2 hours, the temperature during the polymerization process is 65°C, and after the dropwise addition is completed, the reaction is continued at the temperature for 1 hour.

[0097] (4) Cool down to 40°C, add hydrogen peroxide solution, keep warm for 1 hour, then cool down to room temperature, adjust the pH value to 7-8 with ammonia, filter with 200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0098] Example 3

[0099] Weigh the following components by mass:

[0100] 7kg of polyvinyl chloride water latex

[0101] 0.15 kg of bis(thioglycolic acid) glycol ester

[0102] 1.8kg of deionized water

[0103] Sodium dodecylbenzenesulfonate 0.03 kg

[0104] Fatty alcohol polyoxyethylene ether 0.06kg

[0105] Sodium allyl hydroxypropanesulfonate 0.03 kg

[0106] Sodium persulfate 0.015 kg

[0107] Hydroxyethyl acrylate 0.15kg

[0108] 1.2 kg of styrene

[0109] 2kg of butyl acrylate

[0110] 0.2 kg of methyl methacrylate

[0111] 0.15 kg of methacrylic acid

[0112] Acrylamide 0.1kg

[0113] Sodium bisulfite 0.008 kg

[0114] 0.04 kg of hydrogen peroxide aqueous solution

[0115] 0.015 kg of ammonia water

[0116] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex was added to the reactor, stirred and heated to 85°C, and kept warm for 30 minutes. Then, bis(thioglycolic acid) glycol ester was added to the reactor and reacted at 85°C for 30 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0117] (2) Add deionized water, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, sodium allyl hydroxypropanesulfonate, hydroxyethyl acrylate, styrene, butyl acrylate, methyl methacrylate, methacrylic acid and acrylamide to a stirrer and stir at high speed for 30 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0118] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, while an aqueous solution of sodium persulfate and sodium bisulfite is added dropwise. The dropwise addition time of the pre-emulsion is 2 hours, the temperature during the polymerization process is 65°C, and after the dropwise addition is completed, the reaction is continued at the temperature for 1 hour.

[0119] (4) Cool down to 40°C, add hydrogen peroxide solution, keep warm for 1 hour, then cool down to room temperature, adjust the pH value to 7-8 with ammonia, filter with 200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0120] Example 4

[0121] Weigh the following components by mass:

[0122] 7kg of polyvinyl chloride water latex

[0123] 0.07 kg of bis(thioglycolic acid) glycol ester

[0124] 0.42 kg of deionized water

[0125] Sodium dodecylbenzenesulfonate 0.028 kg

[0126] Sodium persulfate 0.005 kg

[0127] Sodium bisulfite 0.002 kg

[0128] 0.7 kg of butyl acrylate

[0129] 0.63 kg of methyl methacrylate

[0130] 0.07 kg of acrylic acid

[0131] 0.007 kg of hydrogen peroxide aqueous solution

[0132] 0.0042 kg of ammonia water

[0133] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex was added to the reactor, stirred and heated to 40°C, kept warm for 30 minutes, and then bis(thioglycolic acid) glycol ester was added to the reactor. The reaction was carried out at 40°C for 10 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0134] (2) Add deionized water, sodium dodecylbenzenesulfonate, butyl acrylate, methyl methacrylate and acrylic acid to a stirrer and stir at high speed for 10 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0135] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, while an aqueous solution of sodium persulfate and sodium bisulfite is added dropwise. The dropwise addition time of the pre-emulsion is 0.5 hours, the temperature during the polymerization process is 40°C, and after the dropwise addition is completed, the reaction is continued at the temperature for 0.5 hours.

[0136] (4) Cool down to 30°C, add hydrogen peroxide solution, keep warm for 0.5 hours, then cool down to room temperature, adjust the pH value to 6-7 with ammonia, filter with 100 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0137] Example 5

[0138] Weigh the following components by mass:

[0139] 7kg of polyvinyl chloride water latex

[0140] 0.7 kg of trimethylolpropane tris(3-mercaptopropionic acid) ester

[0141] 1.12 kg of deionized water

[0142] Sodium dodecylbenzenesulfonate 0.03 kg

[0143] Fatty alcohol polyoxyethylene ether 0.054kg

[0144] Sodium persulfate 0.042 kg

[0145] 1.26 kg of styrene

[0146] 1.4 kg of butyl acrylate

[0147] Acrylamide 0.14kg

[0148] 0.042 kg of hydrogen peroxide aqueous solution

[0149] 0.0112 kg of ammonia water

[0150] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex was added to the reactor, stirred and heated to 80°C, and kept warm for 60 minutes. Then, trimethylolpropane tris(3-mercaptopropionic acid) ester was added to the reactor and reacted at 80°C for 60 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0151] (2) Add deionized water, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, styrene, butyl acrylate and acrylamide to a stirrer and stir at high speed for 30 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0152] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, and sodium persulfate aqueous solution is added dropwise at the same time. The dropwise addition time of the pre-emulsion is 3 hours, the temperature during the polymerization process is 80℃, and after the dropwise addition is completed, the reaction is kept at the temperature for 2 hours.

[0153] (4) Cool down to 40°C, add hydrogen peroxide solution, keep warm for 2 hours, then cool down to room temperature, adjust the pH value to 8-9 with ammonia, filter with 200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0154] Example 6

[0155] Weigh the following components by mass:

[0156] 7kg of polyvinyl chloride water latex

[0157] 1.4 kg of trimethylolpropane tris(3-mercaptopropionic acid) ester

[0158] 2.1kg of deionized water

[0159] Sodium dodecylbenzenesulfonate 0.078 kg

[0160] Fatty alcohol polyoxyethylene ether 0.06kg

[0161] Sodium allyl hydroxypropanesulfonate 0.03 kg

[0162] Sodium persulfate 0.084 kg

[0163] Sodium bisulfite 0.042 kg

[0164] Hydroxyethyl acrylate 0.15kg

[0165] 1.6 kg of styrene

[0166] 2kg of butyl acrylate

[0167] 0.2 kg of methyl methacrylate

[0168] 0.15 kg of methacrylic acid

[0169] Acrylamide 0.1kg

[0170] 0.126 kg of hydrogen peroxide aqueous solution

[0171] 0.021 kg of ammonia water

[0172] (1) Under a nitrogen atmosphere, polyvinyl chloride water latex was added to the reactor, stirred and heated to 95°C, and kept at that temperature for 90 minutes. Then, trimethylolpropane tris(3-mercaptopropionic acid) ester was added to the reactor and reacted at 95°C for 120 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups.

[0173] (2) Add deionized water, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, sodium allyl hydroxypropanesulfonate, hydroxyethyl acrylate, styrene, butyl acrylate, methyl methacrylate, methacrylic acid and acrylamide to a stirrer and stir at high speed for 60 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0174] (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, while an aqueous solution of sodium persulfate and sodium bisulfite is added dropwise. The dropwise addition time of the pre-emulsion is 5 hours, the temperature during the polymerization process is 85°C, and after the dropwise addition is completed, the reaction is continued at the temperature for 3 hours.

[0175] (4) Cool down to 50°C, add hydrogen peroxide solution, keep warm for 3 hours, then cool down to room temperature, adjust the pH value to 9-10 with ammonia, filter with 200 mesh filter cloth to obtain interfacial cross-linked core-shell type polyvinyl chloride copolymer resin water latex.

[0176] Comparative Example

[0177] Weigh the following components by mass:

[0178] 7kg of polyvinyl chloride water latex

[0179] 1.8kg of deionized water

[0180] Sodium dodecylbenzenesulfonate 0.03 kg

[0181] Fatty alcohol polyoxyethylene ether 0.06kg

[0182] Sodium allyl hydroxypropanesulfonate 0.03 kg

[0183] Sodium persulfate 0.015 kg

[0184] Hydroxyethyl acrylate 0.15kg

[0185] 1.2 kg of styrene

[0186] 2kg of butyl acrylate

[0187] 0.2 kg of methyl methacrylate

[0188] 0.15 kg of methacrylic acid

[0189] Acrylamide 0.1kg

[0190] Sodium bisulfite 0.008 kg

[0191] 0.04 kg of hydrogen peroxide aqueous solution

[0192] 0.015 kg of ammonia water

[0193] (1) Add deionized water, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether, sodium allyl hydroxypropane sulfonate, hydroxyethyl acrylate, styrene, butyl acrylate, methyl methacrylate, methacrylic acid and acrylamide to a stirrer and stir at high speed for 30 minutes at 25°C to obtain a pre-emulsion of the shell polymer.

[0194] (2) Under a nitrogen atmosphere, polyvinyl chloride water latex is added to the reactor, stirred and heated to 65°C, and kept at the temperature for 30 minutes. The pre-emulsion is added dropwise to the polyvinyl chloride water latex at a uniform rate, while sodium persulfate and sodium bisulfite aqueous solutions are added dropwise. The dropwise addition time of the pre-emulsion is 2 hours, the temperature during the polymerization process is 65°C, and after the dropwise addition is completed, the reaction is kept at the temperature for 1 hour.

[0195] (3) Cool down to 40°C, add hydrogen peroxide solution, keep warm for 1 hour, then cool down to room temperature, adjust the pH value to 7-8 with ammonia, filter with 200 mesh filter cloth to obtain core-shell type polyvinyl chloride copolymer resin water latex.

[0196] The water-based latexes prepared in Examples 1 to 6 and the comparative example were subjected to performance tests according to the national standard GB / T 20623-2006. The test results are shown in the table below:

[0197]

[0198] As can be seen from the performance test results in the table above, the interfacial crosslinked core-shell polyvinyl chloride copolymer resin water emulsions prepared in Examples 1 to 6 meet the basic performance requirements for architectural coating emulsions in the national standard GB / T 20623-2006, compared with the polyvinyl chloride copolymer resin water emulsions prepared by the conventional method in the comparative examples.

[0199] The water-based latexes prepared in Examples 1 to 6 and the comparative example were used to prepare films according to industry standard JC / T 1017-2006, and their performance was tested. The test results are shown in the table below:

[0200]

[0201] The performance test results in the table above show that the films prepared from the interfacially cross-linked core-shell polyvinyl chloride copolymer resin water-based latex in Examples 1 to 6 had water absorption rates of 4.3%, 3.1%, 5.5%, 7.4%, 5.7%, and 6.3% respectively after a 24-hour water absorption test, all lower than the industry standard requirement of 8%. In contrast, the film prepared from the comparative example of polyvinyl chloride copolymer resin water-based latex had a water absorption rate of 11.2% after a 24-hour water absorption test, failing to meet the national standard. After a 168-hour alkali resistance test, none of the films showed blistering or ulceration. Therefore, this indicates that the polyvinyl chloride-acrylate copolymer resin water-based latex, which achieves core-shell interfacial bonding through click chemical reaction, fully utilizes the excellent film-forming properties of polyacrylate and the outstanding water-repellent properties of polyvinyl chloride, achieving optimal overall film performance.

[0202] This invention provides a core-shell type polyvinyl chloride copolymer resin aqueous latex prepared through a mercapto-olefin click chemistry reaction. This latex enables the polyvinyl chloride seed and the shell polymer to be covalently bonded, which enhances the bonding force between the polyvinyl chloride seed and the shell polymer. It fully utilizes the complementary properties of polyvinyl chloride and the shell polymer, resulting in a polyvinyl chloride copolymer resin aqueous latex film with high water-resistant performance and improved overall performance.

[0203] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemical reaction, characterized in that, Includes the following steps: (1) Under a nitrogen atmosphere, polyvinyl chloride water latex is added to the reactor, stirred and heated to 40-95°C, kept warm for 30-90 minutes, and then a monomer containing polythiol groups is added to the reactor. The reaction is carried out at 40-95°C for 10-120 minutes to obtain polyvinyl chloride seed water latex with surface grafted thiol groups. (2) Add deionized water, emulsifier, and alkenyl-containing monomer to a stirrer and stir at high speed at 25°C for 10 to 60 minutes to obtain a pre-emulsion of shell polymer; (3) The pre-emulsion is added dropwise to the polyvinyl chloride seed water latex at a uniform rate, and an initiator is added dropwise at the same time. The dropwise addition time of the pre-emulsion is 0.5 to 5 hours, the temperature during the polymerization process is 40 to 85°C, and after the dropwise addition is completed, the reaction is continued to be kept at the temperature for 0.5 to 3 hours. (4) Cool down to 30-50℃, add the initiator aqueous solution, keep warm for 0.5-3 hours, then cool down to room temperature, adjust the pH value to 6-10 using pH adjuster, filter with 100-200 mesh filter cloth to obtain core-shell type polyvinyl chloride copolymer resin water latex.

2. The method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry reaction as described in claim 1, characterized in that, The mass of the polythiol-containing monomer is 1-20% of the mass of the polyvinyl chloride aqueous latex, the mass of the alkenyl-containing monomer is 20-60% of the mass of the polyvinyl chloride aqueous latex, the mass of the deionized water is 30-50% of the mass of the alkenyl-containing monomer, the mass of the emulsifier is 2-4% of the mass of the alkenyl-containing monomer, the mass of the initiator is 0.5-3% of the mass of the alkenyl-containing monomer, the mass of the post-initiator aqueous solution is 0.5-3% of the mass of the alkenyl-containing monomer, the mass of the pH adjuster is 0.3-0.5% of the mass of the alkenyl-containing monomer, and the polyvinyl chloride content in the polyvinyl chloride aqueous latex is 35-45%.

3. The method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry reaction as described in claim 1, characterized in that, The monomer containing multiple thiol groups is one or more of the following: butanediol bis(thioglycolic acid ester), bis(thioglycolic acid) ethylene glycol ester, bis(thioethyl) ether, butanedithiol, pentanedithiol, hexanedithiol, heptamethnithiol, trimethylolpropane tri(3-mercaptopropionic acid) ester, and trimethylolpropane tri(thioglycolic acid).

4. The method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemical reaction as described in claim 1, characterized in that, The alkenyl-containing monomers include one or more of the following: hard alkenyl monomers, soft alkenyl monomers, and alkenyl monomers containing hydroxyl, carboxyl, amide, or epoxy groups.

5. The method for preparing interfacially cross-linked core-shell polyvinyl chloride copolymer water latex via click chemistry reaction as described in claim 4, characterized in that, The olefinic hard monomer is one or more of styrene, methyl methacrylate, and acrylonitrile; The olefinic soft monomer is one or more selected from butyl acrylate, ethyl acrylate, hexyl acrylate, and 2-ethylhexyl acrylate; The olefin monomer containing hydroxyl, carboxyl, amide, or epoxy groups is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, methacrylic acid, acrylamide, and glycidyl methacrylate.

6. A core-shell polyvinyl chloride copolymer resin aqueous emulsion prepared by the method for preparing interfacially crosslinked core-shell polyvinyl chloride copolymer resin aqueous emulsion via click chemical reaction as described in any one of claims 1 to 5, wherein, The polyvinyl chloride core and shell copolymers are cross-linked by covalent bonds formed through a click chemical reaction.

7. The application of a core-shell polyvinyl chloride copolymer resin aqueous emulsion prepared by the method for preparing interfacially crosslinked core-shell polyvinyl chloride copolymer resin aqueous emulsion by click chemical reaction as described in any one of claims 1 to 5 in coatings.

Images