Agglomerated particle and preparation method therefor, and resin composition comprising same

Abstract

Provided in the present application are an agglomerated particle and a preparation method therefor, and a resin composition comprising same. The agglomerated particle comprises a vinyl-based polymer and a coagulant, wherein the coagulant comprises a water-soluble cationic polymer having a nitrogen-containing functional group; and the number-average molecular weight of the water-soluble cationic polymer is less than or equal to 16,000 g / mol. In the present application, the water-soluble cationic polymer having a specific number-average molecular weight and a nitrogen-containing functional group is used as the coagulant, making the obtained coagulated particle have a low metal residue content, a long oxidation induction time, a low yellowness index and antimicrobial and mildew-proof effects; therefore, the resin composition comprising the agglomerated particle also has good thermo-oxidative aging resistance and antimicrobial and mildew-proof properties. Moreover, the agglomerated particle can also be used as an impact modifier to improve the impact resistance of the resin composition.

Description

A cohesive particle and its preparation method, and a resin composition comprising the same. Technical Field

[0001] This application belongs to the field of latex coagulation material technology, specifically relating to a coagulated particle and its preparation method, and a resin composition containing the same. Background Technology

[0002] Aromatic vinyl graft copolymers, such as butadiene-styrene-acrylonitrile copolymer (ABS), butadiene-methyl methacrylate-styrene-acrylonitrile copolymer (MABS), butadiene-methyl methacrylate-styrene copolymer (MBS), and acrylonitrile-styrene-acrylate monomer copolymers (ASA), can be synthesized by various methods, including bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization. Compared to other polymerization methods, monomers can more easily yield latexes with high molecular weights, specific particle sizes, or grafted structures through emulsion polymerization. When a solid product is required, a coagulation process is needed to separate the polymer from the latex. This process involves using chemical or physical methods to disrupt the stability of the latex, causing the latex particles to aggregate, thereby separating the polymer from the latex to form latex aggregates. These latex aggregates, with specific particle sizes and low glass transition temperatures, can serve as good toughening agents, providing materials with excellent impact resistance.

[0003] The most mature industrial technology currently available involves mixing latex with an acid or its metal salt under heating conditions, causing the latex particles to aggregate and coagulate by disrupting the latex's electric double layer. This includes the following steps: 1. Preparing a coagulant solution containing acid and a metal salt; 2. Mixing the coagulant solution with the polymer latex under heating and stirring conditions to form a coagulated slurry; 3. Adding an appropriate amount of sodium hydroxide solution to adjust the pH of the slurry to near neutral; 4. Separating the slurry from its solid state; 5. Washing and drying the latex powder to obtain the coagulated latex particles. The acid can be an organic or inorganic acid, including sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, citric acid, etc.; the metal salt can be one of magnesium sulfate, aluminum sulfate, calcium chloride, aluminum chloride, ferric chloride, etc. Especially for ABS materials, when only acid is used for coagulation, the latex particles cannot completely coagulate. When the coagulated slurry is separated into solid and liquid phases using equipment such as a centrifuge, the liquid phase is a turbid liquid. Therefore, a certain amount of inorganic salt must be added during the coagulation process to promote complete latex coagulation. However, some metal ions from inorganic salts remain in the adhesive powder, reducing the oxidation induction period (OIT) of the aggregated particles and increasing the ash content of the product. Therefore, large amounts of desalinated water washing are generally required. This type of wash water containing a large amount of metal ions poses a challenge to wastewater treatment, hindering both production cost reduction and environmental protection, as illustrated by solutions disclosed in patents such as US33285073A, US24820562A, US61229745A, and US06515663.

[0004] Furthermore, ABS and other resin products play an indispensable role in daily life and industrial and agricultural applications. However, existing resin products have poor impact resistance, and long-term use and accumulation can lead to the growth of large amounts of bacteria, threatening food safety and human health. To address this issue, antibacterial agents are often added to plastics to form antibacterial resins and resin products. Currently, the mainstream antibacterial materials in antibacterial resins on the market are silver ion antibacterial agents and ZnO series antibacterial agents. However, these antibacterial agents may adversely affect the thermo-oxidative aging properties of the resin, and when added to resin products, they need to be pre-formed into antibacterial masterbatches to ensure uniform dispersion of the antibacterial agent in the resin, resulting in complex processes and high costs.

[0005] Therefore, developing a cohesive particle with low metal salt residue, good resistance to heat and oxygen aging, and the ability to improve the impact resistance and antibacterial and antifungal properties of resin materials is an urgent problem to be solved in this field. Summary of the Invention

[0006] This application provides agglomerated particles, a method for preparing the same, and a resin composition containing the same. The agglomerated particles have low residual metal ions, a long oxidation induction period, a low yellowing index, and antibacterial and antifungal effects. When used to prepare a resin composition, they not only improve the resin composition's resistance to heat and oxygen aging but also enhance its impact resistance and antibacterial and antifungal effects.

[0007] To achieve this objective, the following technical solution is adopted in this application:

[0008] In a first aspect, this application provides a coagulating particle, the coagulating particle comprising a vinyl polymer and a coagulant; the coagulant comprising a water-soluble cationic polymer having nitrogen-containing functional groups; the number-average molecular weight of the water-soluble cationic polymer being ≤16000 g / mol.

[0009] In this application, the coagulant is a water-soluble cationic polymer with nitrogen-containing functional groups, and the number-average molecular weight of the water-soluble cationic polymer is ≤16000g / mol. The resulting coagulated particles have low metal residue, long oxidation induction period, and low yellowing index. Furthermore, the water-soluble cationic polymer with nitrogen-containing functional groups has a high surface charge, which enables it to kill bacteria and fungi through electrostatic interaction, resulting in good antibacterial and antifungal effects. As a result, the resin composition including the coagulated particles also has excellent heat and oxygen aging resistance and good antibacterial and antifungal effects. At the same time, the coagulated particles can also improve the impact resistance of the resin composition.

[0010] In this application, the number average molecular weight of the water-soluble cationic polymer is ≤16000 g / mol, and for example, it can be 500 g / mol, 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3200 g / mol, 3500 g / mol, 3800 g / mol, 4000 g / mol, 4200 g / mol, 4500 g / mol, 4800 g / mol, 5000 g / mol, or 5200 g / mol. The range of values ​​is 5500 g / mol, 5800 g / mol, 6000 g / mol, 6200 g / mol, 6500 g / mol, 6800 g / mol, 7000 g / mol, 7500 g / mol, 8000 g / mol, 8500 g / mol, 9000 g / mol, 9500 g / mol, 10000 g / mol, 11000 g / mol, 12000 g / mol, 14000 g / mol, 16000 g / mol, and any combination thereof.

[0011] Preferably, the number average molecular weight of the water-soluble cationic polymer is 500–15000 g / mol, more preferably 1500–10000 g / mol, and even more preferably 2500–6600 g / mol.

[0012] In this application, if the number-average molecular weight of the water-soluble cationic polymer is too small, too much of the water-soluble cationic polymer will be lost during solid-liquid separation, resulting in poor antibacterial properties of the aggregated particles; if the number-average molecular weight is too large, the solubility of some water-soluble cationic polymers will be low, resulting in a high content of residual coagulant in the aggregated particles, making it difficult to remove metal ions during the washing process, and the resulting aggregated particles will have high cytotoxicity. The resin composition prepared in this way may cause skin irritation.

[0013] Preferably, at 25°C and a pH of 5-9, the surface potential of the water-soluble cationic polymer is 8-82 mV, for example, it can be 8 mV, 10 mV, 12 mV, 14 mV, 15 mV, 16 mV, 18 mV, 20 mV, 22 mV, 24 mV, 26 mV, 28 mV, 30 mV, 32 mV, 34 mV, 36 mV, 38 mV, 40 mV, 4... The range of values ​​is 2mV, 44mV, 46mV, 48mV, 50mV, 52mV, 54mV, 56mV, 58mV, 60mV, 62mV, 64mV, 66mV, 68mV, 70mV, 72mV, 74mV, 76mV, 78mV, 80mV, 82mV, and any combination thereof; preferably 15 to 75mV, more preferably 28 to 50mV.

[0014] In this application, the surface potential of the water-soluble cationic polymer is too small and the surface charge is insufficient, making it difficult for the latex to completely break down; the surface charge of the water-soluble cationic polymer is too high and the cytotoxicity is too great, which causes the aggregated particles and resin composition prepared from such water-soluble cationic polymer to produce certain skin irritation.

[0015] Preferably, the solubility of the water-soluble cationic polymer at room temperature is ≥10 g / L, for example, it can be 10 g / L, 12 g / L, 14 g / L, 16 g / L, 17 g / L, 18 g / L, 19 g / L, 20 g / L, 22 g / L, 24 g / L, 26 g / L, 28 g / L, 30 g / L, 32 g / L, 34 g / L, 36 g / L, 38 g / L, 40 g / L, 42 g / L, 44 g / L. The values ​​are within the ranges of 46 g / L, 48 g / L, 50 g / L, 55 g / L, 60 g / L, 70 g / L, 100 g / L, 200 g / L, 300 g / L, 400 g / L, 500 g / L, 600 g / L, 800 g / L, 1000 g / L, 1200 g / L, 1400 g / L, 1500 g / L, and any combination thereof; more preferably, the solubility is ≥100 g / L, and more preferably, the solubility is ≥1000 g / L.

[0016] Preferably, the nitrogen-containing functional group includes at least one of an amide group, an amino group, an ammonium group, a guanidine group, or a nitrogen-containing aromatic group, and more preferably at least one of an amino group, an ammonium group, or a guanidine group.

[0017] Preferably, the water-soluble cationic polymer includes at least one of chitosan, polyamino acids and their derivatives, polyhexamethylene biguanide and its salts, acrylate polymers containing quaternary ammonium groups, or polycarbonate polymers containing quaternary ammonium groups.

[0018] Preferably, the polyamino acid and its derivatives include at least one of polyamino acids, quaternized derivatives of polyamino acids, guanidineized derivatives of polyamino acids, or quaternized and guanidineized derivatives of polyamino acids.

[0019] In this application, the "and" in "polyamino acids and their derivatives, polyhexamethylene biguanide and their salts" refers to an and / or relationship, such as polyamino acids and their derivatives including polyamino acids and / or polyamino acid derivatives. If the same expression is used below, it has the same meaning.

[0020] In this application, the polyamino acids and their derivatives include linear polyamino acids and their derivatives and / or branched polyamino acids and their derivatives.

[0021] In this application, the polyamino acids and their derivatives include homopolymer polyamino acids and their derivatives and / or copolymer polyamino acids and their derivatives.

[0022] In this application, the monomers of the aforementioned polyamino acids include, but are not limited to, any one or a combination of at least two of lysine, arginine, alanine, isoleucine, phenylalanine, tryptophan, histidine, or glutamine.

[0023] In this application, the water-soluble cationic polymer can be obtained commercially or prepared using conventional methods.

[0024] For example, the preparation method of linear homopolymer polyamino acids or linear copolymer polyamino acids can be carried out by ring-opening polymerization of N-carboxycyclic intracyclic anhydride (NCA); the method includes: mixing NCA-amino acid monomers with a solvent to obtain an amino acid solution with a concentration of 0.1-0.4 g / mL; mixing an amine compound with a solvent to obtain an amine compound solution with a concentration of 2-20 mg / mL; mixing the amino acid solution and the amine compound solution and stirring at room temperature for 24-96 h; and subjecting the resulting reaction mixture to sedimentation and drying. Product A is obtained; then product A is mixed with trifluoroacetic acid to obtain a trifluoroacetic acid solution of product A with a concentration of 0.1 g / mL. A hydrogen bromide acetic acid solution (hydrogen bromide mass fraction of 20-40 wt%) is added to the solution at 0.2-0.6 times the volume of trifluoroacetic acid. After reacting at room temperature for 1-5 hours, the product is settled, dried, and the dried solid is redissolved in water. The pH is adjusted to 8-10 with an alkaline compound, and the product is settled and dried again to obtain the linear homopolymer polyamino acid or linear copolymer polyamino acid. The amine compound includes, but is not limited to, propylamine; the solvent includes, but is not limited to, N,N-dimethylformamide (DMF); the difference between the preparation methods of the linear homopolymer polyamino acid and the linear copolymer polyamino acid lies only in the monomer raw materials; when preparing the linear homopolymer polyamino acid, the monomer is a single amino acid monomer; when preparing the linear copolymer polyamino acid, the monomers are equimolar amounts of different amino acid monomers.

[0025] For example, the preparation method of branched homopolymeric polyamino acids and branched copolymeric polyamino acids can be as follows:

[0026] An aqueous solution of an amino acid monomer or its hydrochloride salt is mixed with an aqueous solution of an alkaline compound at a mass ratio of (2-5):1. The mixture is reacted at 200-300°C for 20-50 minutes under a protective atmosphere. The resulting product is then precipitated and dried to obtain the branched homopolymer polyamino acid or branched copolymer polyamino acid. The aqueous solution of the alkaline compound includes, but is not limited to, an aqueous solution of potassium hydroxide. The mass fraction of the potassium hydroxide aqueous solution is 10-30 wt%. The difference between the preparation methods of the branched homopolymer polyamino acid and the branched copolymer polyamino acid lies only in the different monomer raw materials. When preparing the branched homopolymer polyamino acid, the monomer is a single amino acid monomer. When preparing the branched copolymer polyamino acid, the monomers are equimolar amounts of different amino acid monomers.

[0027] Exemplarily, the preparation method of the quaternized derivative of the polyamino acid includes: mixing the polyamino acid with a quaternizing agent and a solvent to obtain a reaction solution; wherein the mass ratio of the polyamino acid to the quaternizing agent in the reaction solution is (1-4):1, and the total concentration of the polyamino acid and the quaternizing agent in the reaction solution is 0.02-0.1 g / mL; reacting the reaction solution at 30-60°C for 12-36 h, settling, and drying to obtain the quaternized derivative of the polyamino acid; wherein the polyamino acid includes linear homopolymer polyamino acid, linear copolymer polyamino acid, branched homopolymer polyamino acid, or branched copolymer polyamino acid; the quaternizing agent includes compounds containing an acrylamide group and / or an ammonium group, such as N,N-dimethyl-N-alkylacrylamide compounds, wherein the alkyl group can be a C7-C18 straight-chain or branched alkyl group; or (2-acrylamidoethyl)ammonium salt with different substituents on N, wherein the substituents include C1-C10 straight-chain or branched alkyl groups.

[0028] For example, the method for preparing the guanidinolated derivative of the polyamino acid includes the following steps:

[0029] A guanidinizing agent, potassium carbonate, and an aqueous solution of a polyamino acid (the polyamino acid mass fraction is 1-4 wt%) are mixed to obtain a reaction solution (in which the molar amounts of the guanidinizing agent and potassium carbonate are equal). The degree of guanidinization modification of the polyamino acid can be adjusted by regulating the mass ratio (or molar ratio) of the guanidinizing agent to the polyamino acid. The reaction solution is reacted at 40-80°C for 6-24 hours under a protective atmosphere, followed by precipitation and drying to obtain the guanidinized derivative of the polyamino acid. The polyamino acid includes linear homopolymer polyamino acid, linear copolymer polyamino acid, branched homopolymer polyamino acid, or branched copolymer polyamino acid. The guanidinizing agent includes 1H-pyrazole-1-formamidinium hydrochloride, methoxyisourea (or its sulfate), or sodium 2-ethyl-2-thiourea hydrobromide, etc.

[0030] For example, the preparation method of the acrylate polymer containing quaternary ammonium groups can be carried out using reversible addition-fragmentation chain transfer polymerization (RAFT polymerization); the method includes:

[0031] An acrylate monomer is mixed with an initiator, a chain transfer agent, and a solvent to obtain a reaction solution (the initiator is 0.05–1.5 wt% of the total mass of the acrylate monomers, the chain transfer agent is 5–20 wt% of the total mass of the acrylate monomers, and the total mass concentration of the acrylate monomers, initiator, and chain transfer agent in the reaction solution is 180–240 mg / mL); the reaction solution is reacted at 60–90 °C for 4–12 h under a protective atmosphere, and after sedimentation, centrifugation, and drying, the acrylate polymer is obtained; the acrylate monomer is an acrylate containing amino, ammonium, pyridine, pyrrole, pyrazole, or indole residues, or an acrylate containing the above groups can be obtained by simple treatment after polymerization, including but not limited to any one or at least a combination of two of (meth)acrylate aminoethyl ester and its salts or (meth)acrylate-2-indoleethyl ester. The initiators include, but are not limited to, azo initiators and / or organic peroxide initiators; the azo initiators include, but are not limited to, azobisisobutyronitrile (AIBN); the peroxide initiators include, but are not limited to, benzoyl peroxide (BPO). The chain transfer agents include, but are not limited to, dithioester derivatives, including, but are not limited to, cumyl dithiobenzoate (CDB), 2-cyano-2-propyldodecyl trithiocarbonate, 2-cyano-2-propylbenzodisulfide, 2-phenylpropane thiobenzoate, 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, or 4-cyano-4-[(dodecylthioalkylthiocarbonyl)thioalkyl]valerate, etc. The solvents in the RAFT polymerization include, but are not limited to, dimethyl sulfoxide (DMSO).

[0032] Preferably, the amount of the vinyl polymer added is 100 parts, and the amount of the water-soluble cationic polymer added is 0.2 to 26 parts, for example, 0.2 parts, 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.2 parts, 10.5 parts, 10.8 parts, 11 parts, 11.2 parts, 11.5 parts, 11.8 parts, 12 parts, 12.2 parts, or 12.5 parts. The range of 12.8 parts, 13 parts, 13.2 parts, 13.5 parts, 13.8 parts, 14 parts, 14.2 parts, 14.5 parts, 14.8 parts, 15 parts, 15.2 parts, 15.5 parts, 15.8 parts, 16 parts, 16.2 parts, 16.5 parts, 16.8 parts, 17 parts, 17.5 parts, 18 parts, 18.5 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 26 parts, and any combination thereof; preferably 2 to 18 parts, more preferably 7 to 15 parts.

[0033] In this application, when the amount of water-soluble cationic polymer added is within a specific range, the residual metal ions in the aggregated particles are lower, the oxidation induction period is longer, the yellowing index is lower, and the prepared resin composition has excellent antibacterial and antifungal effects. If the amount of water-soluble cationic polymer added is too small, the oxidation induction period of the aggregated particles becomes shorter and the yellowing index increases. If the amount of water-soluble cationic polymer added is too large, since the water-soluble cationic polymer can adsorb metal ions, if too much is added, it cannot be completely washed away, and the residual amount will lead to an increase in the actual residual metal ion content, and will also induce yellowing, which will also lead to an increase in the yellowing index and a shorter oxidation induction period.

[0034] In this application, the amounts of vinyl polymers and cationic polymers added are both measured by solid mass, i.e., excluding the mass of solvents.

[0035] Preferably, the molecular structure of the vinyl polymer includes any one or a combination of at least two of the following: structural units derived from conjugated dienes, structural units derived from styrene and its derivatives, structural units derived from acrylonitrile and its derivatives, or structural units derived from alkyl (meth)acrylates.

[0036] Preferably, the molecular structure of the vinyl polymer includes structural units derived from conjugated dienes and structural units derived from styrene and its derivatives, and also includes at least one of structural units derived from acrylonitrile and its derivatives and structural units derived from alkyl (meth)acrylates.

[0037] Preferably, the mass percentage of structural units derived from conjugated dienes in the vinyl polymer is 50-80%, for example, it can be a range of 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 72.5%, 73%, 73.5%, 74%, 74.5%, 75%, 75.5%, 76%, 76.5%, 77%, 77.5%, 78%, 78.5%, 79%, 79.5%, 80%, or any combination thereof; preferably 55-78%, more preferably 60-75%; the mass percentage of structural units derived from styrene and its derivatives is 5-36%, for example, it can be 5%, 5.5%, 6%, 6.5%. 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, 23.5%, 24%, 24.5%, 25%, 26%, 28%, 30%, 32%, 34%, 36%, and any combination thereof; the balance being structural units derived from acrylonitrile and its derivatives, and / or structural units derived from alkyl (meth)acrylates.

[0038] In this application, the mass percentage of each structural unit in the vinyl polymer is expressed as the mass percentage of each monomer in the total monomer. For example, the mass percentage of structural units derived from conjugated dienes in the vinyl polymer is 50-80%, which means that the conjugated diene monomer accounts for 50-80% of the total monomer mass.

[0039] In this application, the conjugated diene having ≥4 carbon atoms exemplarily includes, but is not limited to, butadiene, isoprene, hexadiene, heptaadiene, or nonadiene; the styrene and its derivatives include, but are not limited to, any one or a combination of at least two of styrene, α-ethylstyrene, α-methylstyrene, p-methylstyrene, o-tert-butylstyrene, bromostyrene, or chlorostyrene (such as trichlorostyrene); the acrylonitrile and its derivatives include, but are not limited to, acrylonitrile, methacrylonitrile, or fumaric acid. The alkyl (meth)acrylates include, but are not limited to, methyl methacrylate, methyl acrylate, butyl methacrylate, or butyl acrylate.

[0040] In this application, the vinyl polymers include at least one of butadiene-styrene-acrylonitrile copolymer (ABS), butadiene-methyl methacrylate-styrene-acrylonitrile copolymer (MABS), butadiene-methyl methacrylate-styrene copolymer (MBS), or acrylonitrile-styrene-acrylate monomer copolymer (ASA).

[0041] Preferably, the oxidation induction period of the condensed particles in an air atmosphere at an isothermal temperature of 200°C is ≥40 min, more preferably ≥45 min, and even more preferably ≥50 min.

[0042] Preferably, the b-value of the condensed particles, as measured by a Lab colorimeter, is ≤8, more preferably ≤6, and even more preferably ≤4.

[0043] Preferably, the residual metal salt content in the condensed particles is ≤351ppm, more preferably ≤300ppm, and even more preferably ≤250ppm.

[0044] In this application, the condensed particles have a low water content, which is <0.25%.

[0045] Secondly, this application provides a method for preparing condensed particles according to the first aspect, the method comprising the following steps:

[0046] The latex of a vinyl polymer is mixed with a coagulant, and then coagulated and dried to obtain the coagulated particles.

[0047] In this application, the latex of the vinyl polymer can be obtained commercially or prepared using conventional methods. For example, the preparation method includes the following steps:

[0048] (1) The solvent, initiator, chain transfer agent, electrolyte, emulsifier and 20% of the surfactant in the formulation are mixed evenly at room temperature. Under the presence of a protective atmosphere, the conjugated diene monomer is added to it. After reacting at 50-60℃ and 100-110rpm for 6-12h, the temperature is raised to 65-75℃ and the speed is raised to 110-125rpm for 8-16h. The temperature is then raised to 70-80℃ and the speed is raised to 135-135rpm for 8-16h. Then, the remaining surfactant is added to it, and after stirring for 20-40min, the mixture is cooled and discharged to obtain polyconjugated diene latex.

[0049] (2) The polyconjugated diene latex obtained in step (1), initiator, chain transfer agent, emulsifier, catalyst, solvent and graft monomer (graft monomer includes at least two of styrene and its derivatives, acrylonitrile and its derivatives or (meth)acrylate alkyl esters) are mixed and reacted at 50-60°C for 1-6 hours. Then, a surfactant is added and the reaction is continued for 0.5-3 hours to obtain the latex of the vinyl polymer.

[0050] In step (1) of the preparation method, the solvent includes water; the mass of the solvent is 80-120 parts per 100 parts of the conjugated diene monomer; the initiator can be a commonly used initiator, including but not limited to one or more of potassium persulfate, ammonium persulfate, or sodium persulfate; the mass of the initiator is 0.1-1 parts per 100 parts of the conjugated diene monomer; the chain transfer agent can be a commonly used chain transfer agent, including but not limited to n-dodecyl mercaptan and / or tert-dodecyl mercaptan; the mass of the chain transfer agent is 0.2-1.2 parts per 100 parts of the conjugated diene monomer; the electrolyte can be a commonly used electrolyte, including but not limited to one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium carbonate, or potassium hydroxide; the mass of the initiator is 80-120 parts per 100 parts of the conjugated diene monomer ... The electrolyte comprises 0.1 to 1 part per 100 parts; the emulsifier may be a commonly used emulsifier, including anionic emulsifiers; the anionic emulsifier includes, but is not limited to, one or more of disproportionated rosin acid soap, stearic acid soap, oleic acid soap, tallow fatty acid soap, lauric acid soap, alkylbenzene sulfonate or sulfate salt; the emulsifier comprises 0.1 to 1 part per 100 parts of the conjugated diene monomer; the surfactant includes alkynyl alcohol surfactants, which can act as emulsifiers, and may be a commonly used alkynyl alcohol surfactant, including, but not limited to, methylpentynyl alcohol or 2,4,7,9-tetramethyl-5-decyn-4,7-diol, ethyl octynyl alcohol, or one or more of these; the total mass of the surfactants comprises 0.1 to 1 part per 100 parts of the conjugated diene monomer.

[0051] In step (2) of the preparation method, the initiator, chain transfer agent, emulsifier, surfactant, and solvent are selected from the same range as those in step (1); and the types of components in steps (1) and (2) are the same or different; based on 100 parts of the dry mass of polyconjugated diene latex, the mass of each of the initiator, chain transfer agent, emulsifier, and surfactant is independently 0.1 to 1 part; the catalyst can be selected from commonly used catalysts according to existing technology, including but not limited to tetramethylethylenediamine and / or sodium formaldehyde sulfoxylate; based on 100 parts of the dry mass of polyconjugated diene latex, the mass of the catalyst is 0.2 to 2 parts, and the mass of the solvent is 100 to 140 parts.

[0052] Preferably, the condensation occurs under neutral conditions.

[0053] In this application, the neutral conditions are adjusted by adding a pH adjuster, which includes organic acids and / or inorganic acids; the functionality of the organic acids and / or inorganic acids is 1 to 3, preferably sulfuric acid and / or acetic acid.

[0054] In this application, the mixing is carried out in a solvent, which includes water; the specific steps of the mixing include: adjusting the latex of the vinyl polymer to neutral using a pH adjuster; then premixing the water-soluble cationic polymer with the solvent to obtain a coagulated liquid with a solid content of 4-10%; and mixing the coagulated liquid with the latex of the vinyl polymer at 50-95°C according to a formulation in which the ratio of the amount of vinyl polymer (dry basis) to the amount of water-soluble cationic polymer is 100:0.2-26 (both based on solid weight).

[0055] In this application, the solid content of the coagulated liquid is selected so that the cationic polymer can be fully dissolved, resulting in a solution with a low concentration and good fluidity.

[0056] Preferably, the coagulation includes steps of first heat preservation, heating, second heat preservation, and cooling.

[0057] Preferably, the temperature of the first heat preservation is 70-80℃, for example, it can be 70℃, 72℃, 74℃, 75℃, 76℃, 78℃ or 80℃, etc.; the time is 1-10min, for example, it can be 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min or 10min, etc.

[0058] Preferably, the heating rate is 3 to 7 °C / min, for example, it can be 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min or 7 °C / min.

[0059] Preferably, the temperature of the second heat preservation is 90-100℃, for example, it can be 90℃, 91℃, 92℃, 93℃, 94℃, 95℃, 96℃, 97℃, 98℃, 99℃ or 100℃, etc.; the time is 5-15min, for example, it can be 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min or 15min, etc.

[0060] Preferably, the cooling rate is 0.5 to 4 °C / min, for example, it can be 0.5 °C / min, 1 °C / min, 1.5 °C / min, 2 °C / min, 2.5 °C / min, 3 °C / min, 3.5 °C / min or 4 °C / min, etc., until the temperature drops to room temperature.

[0061] In this application, the process before drying further includes solid-liquid separation of the coagulated slurry; this solid-liquid separation can be achieved through methods such as filtration, centrifugal dehydration, or spray drying. To improve the whiteness of the coagulated powder, the dehydrated powder can be washed. The drying step can be hot air drying on a fluidized bed at a temperature of 50–70°C; or it can be dehydration by extrusion on a wet extruder.

[0062] Thirdly, this application provides a resin composition comprising, by weight, 65 to 95 parts of resin (e.g., a range of 65, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, and any combination thereof) and 5 to 35 parts of the aggregated particles described in the first aspect (e.g., a range of 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, and any combination thereof).

[0063] Preferably, the resin comprises at least one selected from styrene-acrylonitrile copolymer, polymethyl methacrylate, methyl methacrylate-styrene-acrylonitrile terpolymer, polystyrene, polyvinyl chloride, polycarbonate, polypropylene, polyphenylene ether, polyester, or polyamide.

[0064] Preferably, the resin composition has an antibacterial rate of ≥90%, more preferably ≥95%, more preferably ≥99%, and particularly preferably ≥99.9%; and an antifungal rating of 0-1.

[0065] In this application, the agglomerated particles can also serve as a good impact modifier, and can be blended and kneaded with other resin materials to form a resin composition. The impact strength of the resin composition can be increased with the increase of the agglomerated particle content.

[0066] The numerical range described in this application includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0067] Compared with the prior art, the beneficial effects of this application are as follows:

[0068] The coagulating particles provided in this application use a water-soluble cationic polymer with nitrogen-containing functional groups as the coagulant, and the number-average molecular weight of the water-soluble cationic polymer is within a specific range. The resulting coagulated particles have low metal ion residue, long oxidation induction period, and low yellowing index. The resin composition including the coagulated particles also has excellent heat and oxygen aging resistance, as well as good antibacterial and antifungal effects and impact resistance. Detailed Implementation

[0069] The technical solution of this application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely to help understand this application and should not be regarded as specific limitations on this application.

[0070] In this application, the solubility test method for the materials used is in accordance with the method specified in GB / T 21845-2008 "Test for water solubility of chemicals".

[0071] In this application, the surface potential of the materials used was tested in accordance with the method specified in GB / Z 42353-2023 "Guide to the Measurement of Zeta Potential".

[0072] In this application, the weight-average molecular weight or number-average molecular weight of the materials used was determined by referring to GB / T31816-2015 "Determination of molecular weight and distribution of polymers in water treatment agents by gel chromatography", and was performed using a Waters ACQUITY ultra-high performance polymer chromatography (APC) gel filtration chromatograph.

[0073] In this application, the moisture content of the latex aggregate particles was determined according to the method specified in GB / T 2914-2008 "Determination of Volatile Matter (Including Water) of Homopolymer Copolymer Resins of Vinyl Chloride". Furthermore, the moisture content of the aggregate particles provided in this application is 0.2%.

[0074] In this application, the pH value was tested according to the JJ-119-84 Laboratory pH (acidity) Meter Verification Procedure.

[0075] All materials used in this application are commercially available or prepared using conventional methods. Unless otherwise specified, the materials used in this application are as follows:

[0076] Preparation Example 1: Preparation of latex of vinyl polymer (A)

[0077] Vinyl polymer A1 latex

[0078] By mass percentage, the molecular structure of the vinyl polymer A1 includes 73% structural units derived from butadiene, 18% structural units derived from styrene, and 9% structural units derived from acrylonitrile.

[0079] The method for preparing the latex of the vinyl polymer A1 includes:

[0080] Step S1: Add 100 parts water, 0.4 parts ammonium persulfate, 0.6 parts n-dodecyl mercaptan, 0.4 parts sodium carbonate, 0.4 parts potassium stearate, and 0.08 parts ethyl octyne alcohol to a reactor and stir at room temperature until completely dissolved and mixed evenly. Purge the reactor with nitrogen to replace the air, so that the oxygen content is below 10 ppm. Then add 100 parts butadiene monomer. Heat the reactor to 55°C and keep it at that temperature for 9 hours for the first stage of polymerization, controlling the stirring speed at 105 rpm. After the first stage of polymerization, heat the system to 70°C and keep it at that temperature for 12 hours for the second stage of polymerization, controlling the stirring speed at 120 rpm. After the second stage of polymerization, heat the system to 75°C and keep it at that temperature for 12 hours for the third stage of polymerization, controlling the stirring speed at 130 rpm. Add 0.32 parts ethyl octyne alcohol at the end of the polymerization reaction, stir for half an hour, cool down, and discharge to obtain polybutadiene latex.

[0081] Step S2: Heat the polybutadiene latex from step S1 to 55°C. Based on 100 parts of dry polybutadiene latex, add 0.4 parts of ammonium persulfate, 0.6 parts of n-dodecyl mercaptan, 0.4 parts of potassium stearate, 1 part of tetramethylethylenediamine, and 120 parts of water. Add the formulated amounts of acrylonitrile monomer and styrene monomer. Add continuously dropwise for 2 hours. After the addition is complete, continue the reaction for 3 hours. Then add 0.4 parts of ethyl octyryne alcohol and continue the reaction at 55°C for 2 hours. After cooling to room temperature, the latex of the vinyl polymer A1 is obtained.

[0082] Vinyl polymers A2 to A7 latex

[0083] The preparation methods of latex for vinyl polymers A2 to A7 are the same as those for vinyl polymer A1. The only difference is that the types and masses of each structural unit of the vinyl polymer are different, that is, the types and proportions of monomers are different (the total amount of monomers is the same). The specific formulations are shown in Table 1, based on the mass percentage (total amount of monomers is 100%). In the table, " / " indicates that the component is not in the formulation.

[0084] Table 1

[0085] Preparation Example 2: Preparation of water-soluble cationic polymer (B)

[0086] Table 2

[0087] The preparation method of B1 includes: adding 91.32g of lysine hydrochloride and 28.05g of KOH solution (20wt%) into a 500mL round-bottom flask, connecting a water separator, purging nitrogen three times for more than 10 minutes each time, and finally maintaining a nitrogen atmosphere, stirring and heating at 250℃ for 30 minutes, then stopping the heating, dissolving the obtained product in methanol and precipitating it into diethyl ether to obtain branched polylysine B1.

[0088] B2: Purchased from McLean, item number P832584.

[0089] The preparation method of B3 includes: dissolving 331 mg of 2-aminoethylmethacrylate (AEMA), 229 mg of 2-(1H-indol-3-yl)ethyl methacrylate (IEMA), 7 mg of azobisisobutyronitrile (AIBN), and 81 mg of chain transfer agent 4-cyano-4-[(dodecylthioalkylthiocarbonyl)thioalkyl]valerate in 3 mL of dimethyl sulfoxide (DMSO), and heating under high vacuum (10 -3 The reaction was carried out under Torr (Temperature) for three cycles of freezing-extraction-thawing, followed by heating to 70°C and reacting for 8 hours. The resulting product was purified by three precipitations with methanol-diethyl ether, centrifuged three times, and dried to obtain a copolymer of aminoethyl methacrylate and 2-indoleethyl methacrylate, which belongs to the acrylate copolymers containing quaternary ammonium groups.

[0090] The preparation method of B41 includes: adding 91.32 g of lysine hydrochloride and 28.05 g of KOH solution (20 wt%) to a 500 mL round-bottom flask, connecting a water separator, purging with nitrogen three times for more than 10 minutes each time, and finally maintaining a nitrogen atmosphere. After stirring and heating at 250 °C for 40 min, the heating is stopped, and the obtained product is dissolved in methanol and precipitated into diethyl ether to obtain branched polylysine; then adding 1.46 g of 1H-pyrazole-1-formamidinium hydrochloride and 1.38 g of potassium carbonate to 80 g of an aqueous solution containing 2.5 wt% branched polylysine; after purging with nitrogen three times, heating the mixed solution at 60 °C for 12 h, then precipitating with diethyl ether, and drying under vacuum to obtain guanidinolated branched polylysine B41, which belongs to the guanidinolated derivative of branched polyamino acids.

[0091] B42: The only difference between it and B41 is that in the preparation method, the reaction is carried out at 250°C with stirring and heating for 60 minutes, while the amount of other raw materials and the step parameters are the same as those of B41.

[0092] B43: The only difference between it and B41 is that in the preparation method, the reaction is carried out at 250°C with stirring and heating for 25 minutes, while the amount of other raw materials and the step parameters are the same as those of B41.

[0093] B44: The only difference between it and B41 is that in the preparation method, the reaction is carried out at 250°C with stirring and heating for 15 minutes, while the amount of other raw materials and the step parameters are the same as those of B41.

[0094] B45: The only difference between it and B41 is that in the preparation method, the reaction is carried out at 250°C with stirring and heating for 90 minutes, while the amount of other raw materials and the step parameters are the same as those of B41.

[0095] B46: The only difference between it and B41 is that in the preparation method, the reaction is carried out at 250°C with stirring and heating for 150 min, while the amount of other raw materials and the step parameters are the same as those of B41.

[0096] Example 1

[0097] This embodiment provides a coagulated particle, which includes a vinyl polymer A1 and a water-soluble cationic polymer B1; based on 100 parts by weight of the vinyl polymer A1, the amount of the water-soluble cationic polymer B1 added is 10.5 parts by weight.

[0098] This embodiment provides a method for preparing condensed particles, including the following steps:

[0099] A water-soluble cationic polymer B1 was mixed with water to obtain a water-soluble cationic polymer aqueous solution with a solid content of 4.3%. The latex of vinyl polymer A1 was adjusted to neutral with concentrated sulfuric acid. Then, at 75°C, the latex of vinyl polymer A1 was added to the cationic polymer aqueous solution in four portions, each time amounting to 25% of the total latex. The resulting mixture was then maintained at 75°C for 5 min, and the temperature was increased to 95°C at a heating rate of 5°C / min and maintained for 10 min. The temperature was then reduced to room temperature at a cooling rate of 2°C / min to obtain a coagulated slurry. The coagulated slurry was dehydrated by a centrifugal dewatering machine and then dried on a fluidized bed at 60°C to obtain the coagulated particles.

[0100] Examples 2-19, Comparative Examples 1-3

[0101] Examples 2-19 and Comparative Examples 1-3 each provide a coagulated particle, differing from Example 1 only in the type of vinyl polymer, the type of coagulant, and their content. Specific formulations are shown in Tables 2, 3, and 4, where " / " indicates the absence of that component in the formulation. The water-soluble cationic polymer B46 used in Comparative Example 1 has poor water solubility; under the same formulation and conditions, a completely dissolved aqueous solution cannot be obtained. B46 is dispersed in the coagulated particles in a solid / semi-solid form. Comparative Example 2 uses glacial acetic acid as the coagulant, which cannot completely demulsify; during solid-liquid separation, the liquid portion still contains a large amount of latex, and the aqueous phase is milky white. Only the portion that has been coagulated and demulsified is used. In contrast, the other examples and comparative examples completely demulsify during the coagulation process, and the aqueous layer during solid-liquid separation is a clear, transparent yellow to light yellow solution.

[0102] Table 3

[0103] Table 4

[0104] Table 5

[0105] Application examples

[0106] This application example provides a resin composition comprising, by weight, 20 parts of coagulated particles and 80 parts of SAN resin (resin brand name KFA-130, Liaoning Jinfeng); the coagulated particles are the coagulated particles provided in Examples 1-19 and Comparative Examples 1-3.

[0107] Performance testing

[0108] (1) Metal residue

[0109] The condensed particles were digested, and the residual metal ion content in the condensed particles was determined by inductively coupled plasma atomic emission spectrometry (ICP) according to HG / T 3944-2007 "Determination of Metal Ion Content in Polyvinyl Chloride Resin".

[0110] (2) Oxidation induction period

[0111] The oxidation induction period of the aggregated particles was tested according to the national standard GB / T 19466.6-2009 "Differential Scanning Calorimetry (DSC) for Plastics - Part 6: Oxidation Induction Time (Isothermal OIT) and Oxidation Induction Temperature (Dynamic OIT)". Specifically, the OIT was tested under isothermal conditions of 200°C in an air atmosphere.

[0112] (3) Heat aging and yellowing resistance

[0113] The dried agglomerated particles were placed in multiple aluminum foil petri dishes and placed in a constant temperature oven at 180℃ for 24 hours. The samples were then removed and the b-value of the agglomerated particles was tested using a Lab colorimeter. The larger the b-value, the worse the heat aging and yellowing resistance.

[0114] (4) Antibacterial and antifungal properties

[0115] The resin composition including the condensed particles was mixed in a twin-screw extruder and pressed into sheets at an upper and lower plate temperature of 200°C on a flat vulcanizer to prepare sheets with a thickness of (50±2)mm×(50±2)mm and not exceeding 10mm. The antibacterial and antifungal properties of the resin composition were then tested.

[0116] The antibacterial performance was tested according to the national standard GB / T 31402-2015 "Test Method for Antibacterial Properties of Plastic Surfaces - Antibacterial Properties of Materials". Specifically, the antibacterial test adopted the film-coating method, and the operation steps were as follows: After the sample was disinfected, a bacterial suspension was inoculated on its surface and covered with a polyethylene film to form a uniform liquid film between the sample and the film. After incubation under certain conditions, the suspension was washed off and diluted to an appropriate concentration gradient. A certain volume was taken and spread on the culture medium for re-incubation and the number of viable bacteria was measured to calculate the antibacterial rate. The antibacterial rate was calculated using the formula: Antibacterial rate % = (Number of bacteria in a pure resin sample after 24 hours - Number of bacteria in the corresponding example or comparative sample after 24 hours) / Number of bacteria in a pure resin sample after 24 hours * 100%. The bacteria used for testing was *Escherichia coli* ATCC 25922.

[0117] The anti-mildew performance was tested in accordance with the national standard GB21551.2-2010 "Special requirements for antibacterial materials with antibacterial, sterilization and purification functions for household and similar electrical appliances"; where 0 indicates the highest level of anti-mildew resistance and 3 indicates the lowest level of anti-mildew resistance.

[0118] (5) Impact resistance: The resin composition including the agglomerated particles is mixed with a twin-screw extruder, and the resin composition is injection molded into a notched standard specimen according to the requirements of GB / T 1843-2008 Determination of cantilever beam impact strength of plastics and its cantilever beam notched impact strength is tested.

[0119] The specific test results are shown in Table 6.

[0120] Table 6

[0121] In addition, taking Example 1 as an example, the cantilever beam notched impact strength of the resin composition including the cohesive particles provided in Example 1 and the SAN resin (resin brand name KFA-130, Liaoning Jinfeng) without cohesive particles (control group) was tested.

[0122] The test results show that the cantilever beam notched impact strength of the resin composition including the coagulated particles provided in Example 1 is 32.2 kJ / m. 2 The notched impact strength of the control group's cantilever beam was 9.1 kJ / m. 2 Therefore, it is evident that the cohesive particles provided in this application can improve the impact strength of the resin, proving that the cohesive particles provided in this application can be used as an impact modifier.

[0123] In summary, the coagulated particles provided in this application use a water-soluble cationic polymer with nitrogen-containing functional groups as a coagulant, and the number-average molecular weight of the water-soluble cationic polymer is within a specific range. The resulting coagulated particles have low metal residue, long oxidation induction period, and low yellowing index. The oxidation induction period of the coagulated particles under air atmosphere and isothermal conditions of 200°C is ≥40 min. After being continuously baked in an oven at 180°C for 24 h, the coagulated particles obtained in this application are whiter than those obtained in the comparative example, with a b-value of less than 7 and a metal residue of less than 351 ppm. The resin composition including the coagulated particles has an antibacterial rate of over 90% and a mildew resistance level of 0 to 1.

[0124] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A coagulating particle comprising a vinyl polymer and a coagulant; The coagulant comprises a water-soluble cationic polymer having nitrogen-containing functional groups; The amount of the vinyl polymer added is 100 parts, and the amount of the water-soluble cationic polymer added is 0.2 to 26 parts; The number-average molecular weight of the water-soluble cationic polymer is ≤16000 g / mol; At 25°C and pH 5–9, the surface potential of the water-soluble cationic polymer is 8–82 mV. The nitrogen-containing functional group includes at least one of an amide group, an amino group, an ammonium group, a guanidine group, or a nitrogen-containing aromatic group; The molecular structure of the vinyl polymer includes any one or a combination of at least two of the following: structural units derived from conjugated dienes, structural units derived from styrene and its derivatives, structural units derived from acrylonitrile and its derivatives, or structural units derived from alkyl (meth)acrylates.

2. The coacervate particle of claim 1, wherein, The number average molecular weight of the water-soluble cationic polymer is 500–15000 g / mol.

3. The coacervate particle of claim 1, wherein, At room temperature, the solubility of the water-soluble cationic polymer is ≥10 g / L.

4. The coagulated particles according to claim 1, wherein, The water-soluble cationic polymer includes at least one of chitosan, polyamino acids and their derivatives, polyhexamethylene biguanide and its salts, acrylate polymers containing quaternary ammonium groups, or polycarbonate polymers containing quaternary ammonium groups. The polyamino acids and their derivatives include at least one of polyamino acids, quaternized derivatives of polyamino acids, guanidineized derivatives of polyamino acids, or quaternized and guanidineized derivatives of polyamino acids.

5. The coagulated particles according to claim 1, wherein, The molecular structure of the vinyl polymer includes structural units derived from conjugated dienes and structural units derived from styrene and its derivatives, and also includes at least one of structural units derived from acrylonitrile and its derivatives or structural units derived from alkyl (meth)acrylates. In the vinyl polymer, the mass percentage of structural units derived from conjugated dienes is 50-80%, the mass percentage of structural units derived from styrene and its derivatives is 5-36%, and the balance is structural units derived from acrylonitrile and its derivatives, and / or structural units derived from alkyl (meth)acrylates.

6. The coagulated particles according to claim 1, wherein, The oxidation induction period of the condensed particles under air atmosphere and isothermal conditions of 200°C is ≥40 min; The condensed particles were measured with a b value ≤ 8 using a Lab colorimeter. The residual metal salt content in the condensed particles is ≤351ppm.

7. A method for preparing condensed particles according to any one of claims 1 to 6, comprising the following steps: The latex of a vinyl polymer is mixed with a coagulant, and then coagulated and dried to obtain the coagulated particles.

8. The production method according to claim 7, wherein The condensation occurs under neutral conditions; The coagulation process includes steps of first heat preservation, heating, second heat preservation, and cooling. The temperature of the first heat preservation is 70-80℃, and the time is 1-10 minutes; The heating rate is 3–7 °C / min; The second heat preservation temperature is 90-100℃, and the time is 5-15 minutes; The cooling rate is 0.5–4 °C / min, until the temperature drops to room temperature.

9. A resin composition comprising, by weight, 65 to 95 parts resin and 5 to 35 parts agglomerated particles as described in any one of claims 1 to 6.

10. The resin composition according to claim 9, wherein, The resin includes at least one of styrene-acrylonitrile copolymer, polymethyl methacrylate, methyl methacrylate-styrene-acrylonitrile terpolymer, polystyrene, polyvinyl chloride, polycarbonate, polypropylene, polyphenylene ether, polyester, or polyamide; The resin composition has an antibacterial rate of ≥90% and a mildew resistance level of 0-1.

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