Calcium carbonate filler particles as well as preparation method and application thereof

Abstract

The invention relates to the technical field of filler modification, in particular to calcium carbonate filler particles as well as a preparation method and application thereof, and the calcium carbonate filler particles comprise 80-120 parts of calcium carbonate, 0.5-2 parts of a silane coupling agent, 1-3 parts of silver powder, 5-15 parts of chitosan, 3-10 parts of a lubricant and 3-10 parts of a dispersant. The silane coupling agent and the calcium carbonate are compounded, organic functional groups are introduced to the surface of the calcium carbonate through silane modification, and a foundation is laid for subsequent combination with antibacterial components (silver powder and chitosan). Meanwhile, the silver powder is compounded with the chitosan, and the chitosan is combined with the silver powder through electrostatic interaction and is adsorbed on the surface of the silver powder, so that the problem that the silver powder is easy to agglomerate is solved, an antibacterial unit of'wrapping the silver powder with the chitosan 'is formed, and the effect of continuously releasing silver ions is achieved. Then the silver powder adsorbed with the chitosan is combined with the silane modified calcium carbonate, and the long-acting antibacterial effect is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filler modification, in particular to a calcium carbonate filler particle and a preparation method and application thereof. BACKGROUND

[0002] Calcium carbonate is an inorganic compound with the chemical formula CaCO3, which is the main component of limestone, marble, etc., and widely exists in barite, calcite, chalk, limestone, marble, and other rocks. It is an inorganic non-metallic filler with wide sources and low cost. Calcium carbonate has been widely used in plastic, paint, rubber, packaging material, etc. fields due to its excellent mechanical reinforcement, chemical stability and processing adaptability. Especially in the high polymer box material such as environmental protection box and turnover box, it can significantly reduce the production cost of the base material (such as polypropylene and polyethylene), and improve the rigidity, wear resistance and dimensional stability of the box. It is one of the core fillers in the current environmental protection box material field.

[0003] However, since the environmental protection box is often used in food turnover, logistics transportation, medical assistance, etc. scenes, it often needs to contact with moisture-containing objects (such as fresh fruits and vegetables, disinfected instruments) or be in a high humidity environment (such as rain season storage, cold chain transportation compartment), which provides conditions for the reproduction of common pathogenic bacteria such as Escherichia coli and Staphylococcus aureus. The traditional calcium carbonate filler itself has no antibacterial activity and cannot inhibit the growth of microorganisms, which can easily lead to bacterial residues on the surface of the box, which can not only cause food spoilage, cross-contamination and other hygiene risks, but also shorten the service life of the box. In the existing scheme, the method of spraying antibacterial coating in the later stage has the problems of easy wear and tear of the coating, short antibacterial duration, and additional process cost, which is difficult to achieve long-term and stable antibacterial effect. Therefore, if the calcium carbonate filler can be endowed with antibacterial property, the problem of microbial growth in the core scenes such as food turnover, medical assistance and outdoor logistics of the environmental protection box can be solved from the root, the reproduction of pathogenic bacteria such as Escherichia coli and Staphylococcus aureus can be effectively inhibited, the hygiene and safety hazards caused by bacterial residues on the box, such as food spoilage and cross-infection, can be avoided, and the use safety and hygiene level of the environmental protection box can be significantly improved. At the same time, the passive antibacterial method of traditional "antibacterial coating spraying in the later stage" can be replaced, the antibacterial component and the filler body can be stably combined, the defects of short antibacterial duration and high maintenance cost caused by wear and tear of the coating can be avoided, and long-term and durable antibacterial effect can be achieved. SUMMARY

[0004] The purpose of the present application is to provide a calcium carbonate filler particle and a preparation method and application thereof. To solve the defect of the traditional calcium carbonate filler that lacks antibacterial performance (which leads to the growth of bacteria in the environmental protection box and causes hygiene safety hazards).

[0005] To achieve the above purpose, the present application provides a calcium carbonate filler particle, which comprises the following raw materials in mass fraction: calcium carbonate 80-120 parts, silane coupling agent 0.5-2 parts, silver powder 1-3 parts, chitosan 5-15 parts, lubricant 3-10 parts, dispersant 3-10 parts.

[0006] In the present application, the calcium carbonate is calcite type calcium carbonate, the particle size is 10-40 . The calcite type calcium carbonate has an appropriate amount of hydroxyl groups (-OH) on the surface, which can react with the silane coupling agent to form stable chemical bonds, ensuring the silane modification effect.

[0007] In the present application, the silane coupling agent includes gamma-aminopropyl triethoxysilane or gamma-glycidyl ether propyl trimethoxysilane.

[0008] In the present application, the particle size of the silver powder is 10-50 nm.

[0009] In the present application, the lubricant includes stearic acid or ethylene bis-stearamide.

[0010] In the present application, the dispersant includes fatty alcohol polyoxyethylene ether or sodium polycarboxylate.

[0011] The present application also provides a preparation method of the above-mentioned calcium carbonate filler particles, comprising the following preparation steps: S1, mixing chitosan and acetic acid solution to obtain a chitosan solution, adding silver powder and dispersant to the chitosan solution, and ultrasonic to obtain a nano-silver chitosan composite dispersion; S2, mixing silane coupling agent and ethanol solution to obtain a silane coupling agent solution, adding calcium carbonate to the silane coupling agent solution, and silane modification to obtain silane modified calcium carbonate; S3, mixing the silane modified calcium carbonate and the nano-silver chitosan composite dispersion to obtain a mixed solution, adjusting the pH of the mixed solution to 7-8, stirring to obtain a mixture; S4, adding lubricant to the mixture, mixing, suction filtration, and vacuum drying to obtain calcium carbonate filler particles.

[0012] In the present application, the volume concentration of the acetic acid solution in S1 is 3%-5%, and the acetic acid solution is only used as a solvent, and its amount is not limited, which can be known by those skilled in the art.

[0013] In the present application, the mass concentration of the ethanol solution in S2 is 90%-95%, and the ethanol solution is only used as a solvent, and its amount is not limited, which can be known by those skilled in the art.

[0014] In the present application, the temperature of ultrasonic in S1 is 20-30 , the power of the ultrasonic is 300-500W, and the time of the ultrasonic is 20-30min; the temperature of the silane modification in S2 is 50-65 , and the time of the silane modification is 1-3h.

[0015] In the present application, after the silane modification in S2, the silane modified product is vacuum dried to obtain the silane modified calcium carbonate. The temperature of the vacuum drying is 50-60 , the vacuum degree of the vacuum drying is 0.08-0.1MPa, and the time of the vacuum drying is 1-2h.

[0016] In the present application, the way of adjusting the pH of the mixed solution in S3 includes adding a pH adjuster into the mixed solution, and the pH adjuster includes ammonia water or sodium hydroxide solution.

[0017] In the present application, the temperature of the stirring in S3 is 25-40 , the time of the stirring is 1-2h, and the rotating speed of the stirring is 200-400rpm; the temperature of the mixing in S4 is 25-40 , and the time of the mixing is 20-40min.

[0018] In the present application, after the suction filtration in S4, the solid material obtained by the suction filtration is washed with ethanol and then vacuum dried. The temperature of the vacuum drying is 40-60 , the vacuum degree of the vacuum drying is 0.08-0.1MPa, and the time of the vacuum drying is 2-4h.

[0019] The present application also provides the application of the above-mentioned calcium carbonate filler particles in preparing environment-friendly box materials.

[0020] The present application has the following beneficial effects: The present application provides a kind of calcium carbonate filler particles, including the following mass fraction of raw materials: calcium carbonate 80-120 parts, silane coupling agent 0.5-2 parts, silver powder 1-3 parts, chitosan 5-15 parts, lubricant 3-10 parts, dispersing agent 3-10 parts. The present application improves the antibacterial performance of calcium carbonate filler particles by silver powder and chitosan double components. Silver powder mainly acts on destroying bacterial cell membrane and interfering DNA replication, while chitosan inhibits bacterial metabolism through positive charge adsorption, and the combination of the two provides broad-spectrum and efficient antibacterial effect.

[0021] The present application compounds silane coupling agent with calcium carbonate, introduces organic functional groups (such as amino, epoxy) on the surface of calcium carbonate through silane modification, modifies calcium carbonate from "hydrophilic inert surface" to "hydrophobic active surface", and lays a foundation for subsequent combination with antibacterial ingredients (silver powder and chitosan). At the same time, silver powder is compounded with chitosan, and chitosan is compounded with chitosan through electrostatic interaction (chitosan protonated amino-NH3 +The silver powder is combined with the negative group on the surface of the silver powder, is adsorbed on the surface of the silver powder, solves the problem of easy agglomeration of the silver powder, forms the antibacterial unit of the silver powder wrapped by the chitosan, and achieves the effect of continuous release of silver ions. Then, the silver powder adsorbed with the chitosan is combined with the silane-modified calcium carbonate, the amino group of the chitosan molecule is combined with the organic functional group (amino group or epoxy group) on the surface of the silane-modified calcium carbonate through hydrogen bond, and finally, the integrated composite particle structure of "the calcium carbonate as a matrix, the silane-modified layer as a connecting bridge, and the chitosan-silver powder as an antibacterial layer" is formed, so that the long-acting antibacterial effect is achieved.

[0022] The technical solutions of the present application are further described below through examples. DETAILED DESCRIPTION

[0023] The present application is further described below through examples. Unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the general meanings understood by those skilled in the art to which the present application belongs. The features mentioned in the present application or the features mentioned in the specific examples can be combined arbitrarily, and these specific examples are only used to illustrate the present application and are not used to limit the scope of the present application.

[0024] Example 1 A calcium carbonate filler particle includes the following raw materials in mass fraction: 100 parts of calcium carbonate, 1 part of γ-aminopropyl triethoxysilane (silane coupling agent), 2 parts of silver powder, 8 parts of chitosan, 3 parts of stearic acid (lubricant), and 6 parts of sodium polycarboxylate (dispersant).

[0025] The calcium carbonate is calcite-type calcium carbonate with a particle size of 30 The particle size of the silver powder is 20 nm.

[0026] The preparation method of the above-mentioned calcium carbonate filler particle includes the following preparation steps: S1, chitosan is mixed with an acetic acid solution with a volume concentration of 3% to obtain a chitosan solution, silver powder and sodium polycarboxylate are added to the chitosan solution, and ultrasonic treatment is performed at a power of 300 W for 20 min at a temperature of 25 to obtain a nano-silver chitosan composite dispersion solution; S2, γ-aminopropyl triethoxysilane is mixed with an ethanol solution with a mass concentration of 90% to obtain a silane coupling agent solution, calcium carbonate is added to the silane coupling agent solution, and silane modification is performed at a temperature of 50 for 1.5 h to obtain a silane-modified product, and the silane-modified product is vacuum dried (the parameters of vacuum drying are: a temperature of 50 , a vacuum degree of 0.08 MPa, and a time of 2 h) to obtain silane-modified calcium carbonate; S3, the silane-modified calcium carbonate and the nano-silver The chitosan composite dispersion liquid is mixed to obtain a mixed solution, a sodium hydroxide solution is added into the mixed solution, the pH of the mixed solution is adjusted to 8, and then the mixed solution is stirred at a temperature of 40 and a rotating speed of 200 rpm for 2 h to obtain a mixture; S4, stearic acid is added into the mixture, and the mixture is mixed at a temperature of 25 for 30 min, and then the mixture is vacuum dried at a temperature of 50 for 3 h under a vacuum degree of 0.08 MPa to obtain calcium carbonate filler particles.

[0027] Example 2 A kind of calcium carbonate filler particles, including the following mass fractions of raw materials: calcium carbonate 95 parts, γ-aminopropyl triethoxysilane (silane coupling agent) 1.2 parts, silver powder 2 parts, chitosan 6 parts, stearic acid (lubricant) 3 parts, and sodium polycarboxylate (dispersant) 4 parts.

[0028] The calcium carbonate is calcite type calcium carbonate, and the particle size is 30 nm.

[0029] The preparation method of the above calcium carbonate filler particles includes the following preparation steps: S1, chitosan is mixed with acetic acid solution with a volume concentration of 5% to obtain a chitosan solution, silver powder and sodium polycarboxylate are added into the chitosan solution, and the mixture is ultrasonically treated at a temperature of 30 for 30 min with a power of 300 W to obtain nano-silver chitosan composite dispersion liquid; S2, γ-aminopropyl triethoxysilane is mixed with ethanol solution with a mass concentration of 90% to obtain a silane coupling agent solution, calcium carbonate is added into the silane coupling agent solution, and the silane modification is performed at a temperature of 60 for 2 h to obtain a silane modified product, and the silane modified product is vacuum dried (the parameters of vacuum drying are: temperature 50 , vacuum degree 0.08 MPa, and time 1.5 h) to obtain silane modified calcium carbonate; S3, the silane modified calcium carbonate is mixed with the nano-silver chitosan composite dispersion liquid to obtain a mixed solution, a sodium hydroxide solution is added into the mixed solution, the pH of the mixed solution is adjusted to 8, and then the mixed solution is stirred at a temperature of 35 for 1 h with a rotating speed of 400 rpm to obtain a mixture; S4, stearic acid is added into the mixture, and the mixture is mixed at a temperature of 25 for 30 min, and then the mixture is vacuum dried at a temperature of 50 vacuum drying at 60

[0030] Example 3 A calcium carbonate filler particle, comprising the following raw materials in mass fraction: calcium carbonate 80 parts, γ-glycidoxypropyltrimethoxysilane (silane coupling agent) 0.5 parts, silver powder 3 parts, chitosan 13 parts, ethylene bis-stearamide (lubricant) 5 parts, sodium polycarboxylate (dispersant) 3 parts.

[0031] The calcium carbonate is calcite-type calcium carbonate, and the particle size is 30 The particle size of the silver powder is 20 nm.

[0032] The preparation method of the calcium carbonate filler particle comprises the following preparation steps: S1, mixing chitosan with an acetic acid solution with a volume concentration of 3% to obtain a chitosan solution, adding silver powder and sodium polycarboxylate to the chitosan solution, and ultrasonically treating at a power of 300 W for 30 min at a temperature of 20 to obtain a nano-silver chitosan composite dispersion solution; S2, mixing γ-glycidoxypropyltrimethoxysilane with an ethanol solution with a mass concentration of 90% to obtain a silane coupling agent solution, adding calcium carbonate to the silane coupling agent solution, and silane-modifying at a temperature of 65 for 1 h to obtain a silane-modified product, vacuum drying (the vacuum drying parameters are: a temperature of 60 , a vacuum degree of 0.08 MPa, and a time of 1 h) to obtain silane-modified calcium carbonate; S3, mixing the silane-modified calcium carbonate with the nano-silver chitosan composite dispersion solution to obtain a mixed solution, adding ammonia water to the mixed solution to adjust the pH of the mixed solution to 7, and then stirring at a speed of 400 rpm at a temperature of 40 for 1.5 h to obtain a mixture; S4, adding ethylene bis-stearamide to the mixture, mixing at a temperature of 25 for 40 min, suction filtering, washing the solid material obtained by suction filtering with ethanol for 3 times, and vacuum drying at a vacuum degree of 0.08 MPa, a temperature of 60 for 2 h to obtain the calcium carbonate filler particle.

[0033] Example 4 A calcium carbonate filler particle, comprising the following raw materials in mass fraction: Calcium carbonate 115 parts, gamma-aminopropyl triethoxysilane (silane coupling agent) 2 parts, silver powder 3 parts, chitosan 15 parts, stearic acid (lubricant) 10 parts, fatty alcohol polyoxyethylene ether (dispersant) 10 parts.

[0034] The calcium carbonate is calcite calcium carbonate with a particle size of 30 nm, and the silver powder has a particle size of 20 nm.

[0035] The preparation method of the calcium carbonate filler particles comprises the following preparation steps: S1, mixing chitosan with an acetic acid solution with a volume concentration of 3% to obtain a chitosan solution, adding silver powder and fatty alcohol polyoxyethylene ether into the chitosan solution, and performing ultrasonic treatment at a power of 300 W for 20 min at a temperature of 25 to obtain a nano-silver chitosan composite dispersion solution; S2, mixing gamma-aminopropyl triethoxysilane with an ethanol solution with a mass concentration of 90% to obtain a silane coupling agent solution, adding calcium carbonate into the silane coupling agent solution, and performing silane modification for 3 h at a temperature of 55 to obtain a silane modified product, and vacuum drying (the parameters of vacuum drying are: a temperature of 50 , a vacuum degree of 0.08 MPa, and a time of 1.5 h) to obtain silane modified calcium carbonate; S3, mixing the silane modified calcium carbonate and the nano-silver chitosan composite dispersion solution to obtain a mixed solution, adding ammonia water into the mixed solution to adjust the pH of the mixed solution to 7, and then stirring at a speed of 400 rpm for 1.5 h at a temperature of 40 to obtain a mixture; S4, adding stearic acid into the mixture, mixing for 20 min at a temperature of 40 , and performing suction filtration, washing the solid material obtained by suction filtration with ethanol for 3 times, and vacuum drying at a temperature of 50 for 2 h under a vacuum degree of 0.08 MPa to obtain calcium carbonate filler particles.

[0036] Example 5 A calcium carbonate filler particle comprises the following raw materials in mass fractions: Calcium carbonate 120 parts, gamma-aminopropyl triethoxysilane (silane coupling agent) 2 parts, silver powder 1 part, chitosan 5 parts, ethylene bis-stearamide (lubricant) 8 parts, and sodium polycarboxylate (dispersant) 8 parts.

[0037] The calcium carbonate is calcite calcium carbonate with a particle size of 30 nm, and the silver powder has a particle size of 20 nm.

[0038] The preparation method of the calcium carbonate filler particles comprises the following preparation steps: S1, mixing chitosan with acetic acid solution with a volume concentration of 5% to obtain a chitosan solution, adding silver powder and sodium polycarboxylate into the chitosan solution, and performing ultrasonic treatment at a power of 400 W for 30 min at a temperature of 20 to obtain a nano-silver chitosan composite dispersion solution; S2, mixing γ-aminopropyl triethoxysilane with ethanol solution with a mass concentration of 95% to obtain a silane coupling agent solution, adding calcium carbonate into the silane coupling agent solution, and performing silane modification at a temperature of 50 for 3 h to obtain a silane modified product, and vacuum drying the silane modified product (the vacuum drying parameters are: a temperature of 55 , a vacuum degree of 0.08 MPa, and a time of 2 h) to obtain silane modified calcium carbonate; S3, mixing the silane modified calcium carbonate and the nano-silver chitosan composite dispersion solution to obtain a mixed solution, adding sodium hydroxide solution into the mixed solution to adjust the pH of the mixed solution to 8, and then stirring at a rotating speed of 300 rpm for 1 h at a temperature of 25 to obtain a mixture; S4, adding ethylene bis-stearamide into the mixture, mixing at a temperature of 25 for 30 min, and performing suction filtration, washing the solid material obtained by suction filtration with ethanol for 3 times, and vacuum drying at a vacuum degree of 0.08 MPa and a temperature of 40 for 4 h to obtain calcium carbonate filler particles.

[0039] Comparative Example 1 A kind of calcium carbonate filler particles, comprising the following mass fractions of raw materials: calcium carbonate 100 parts, γ-aminopropyl triethoxysilane (silane coupling agent) 1 part, and stearic acid (lubricant) 3 parts.

[0040] The calcium carbonate is calcite type calcium carbonate, and the particle size is 30 .

[0041] The preparation method of the calcium carbonate filler particles comprises the following preparation steps: S1, mixing γ-aminopropyl triethoxysilane with ethanol solution with a mass concentration of 90% to obtain a silane coupling agent solution, adding calcium carbonate into the silane coupling agent solution, and performing silane modification at a temperature of 50 for 1.5 h to obtain a silane modified product, and vacuum drying the silane modified product (the vacuum drying parameters are: a temperature of 50 , a vacuum degree of 0.08 MPa, and a time of 2 h) to obtain silane modified calcium carbonate; S2, the silane-modified calcium carbonate, water and stearic acid were mixed at 25 °C for 30 min, filtered, and then vacuum dried at 50 °C for 3 h under a vacuum of 0.08 MPa to obtain the calcium carbonate filler particles.

[0042] Antibacterial performance test: The calcium carbonate filler particles prepared in Examples 1-5 and Comparative Example 1 were subjected to antibacterial test according to the ISO 22196-2011 standard, and the results are shown in Table 1.

[0043] Table 1. Results of antibacterial performance test

[0044] Note: "-" means no antibacterial performance.

[0045] As can be seen from Table 1, the calcium carbonate filler particles provided by the present application have excellent antibacterial performance, wherein the antibacterial rates against Staphylococcus aureus and Escherichia coli can both reach 99.9%.

[0046] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. Calcium carbonate filler particles, characterized in that, The raw materials include the following mass fractions: calcium carbonate 80-120 parts, silane coupling agent 0.5-2 parts, silver powder 1-3 parts, chitosan 5-15 parts, lubricant 3-10 parts, dispersant 3-10 parts.

2. The calcium carbonate filler particles according to claim 1, characterized in that Calcium carbonate is calcite-type calcium carbonate, particle size is 10-40 .

3. The calcium carbonate filler particles according to claim 1, characterized in that, The silane coupling agent includes γ-aminopropyl triethoxysilane or γ-glycidyl ether oxygen propyl trimethoxysilane.

4. The calcium carbonate filler particles according to claim 1, characterized in that, The particle size of the silver powder is 10-50 nm.

5. The calcium carbonate filler particles according to claim 1, characterized in that, The lubricant includes stearic acid or ethylene bis-stearamide.

6. The calcium carbonate filler particles according to claim 1, characterized in that, The dispersant includes fatty alcohol polyoxyethylene ether or sodium polycarboxylate.

7. A process for the production of calcium carbonate filler particles according to any one of claims 1 to 6, characterized in that, The preparation steps include the following steps: S1, mixing chitosan with acetic acid solution to obtain chitosan solution, adding silver powder and dispersant into the chitosan solution, and ultrasonicating to obtain nano-silver Chitosan composite dispersion S2, mixing the silane coupling agent with an ethanol solution to obtain a silane coupling agent solution, adding calcium carbonate to the silane coupling agent solution, silane modification, and obtaining silane-modified calcium carbonate; S3, silane-modified calcium carbonate and nano-silver The chitosan composite dispersion liquid is mixed to obtain a mixed solution, the pH of the mixed solution is adjusted to 7-8, and the mixed solution is stirred to obtain a mixture. S4, adding a lubricant to the mixture, mixing, suction filtering, and vacuum drying to obtain calcium carbonate filler particles.

8. A process for the preparation of calcium carbonate filler particles according to claim 7, characterized in that, The temperature of the ultrasonic in S1 is 20-30 The power of the ultrasonic is 300-500 W, and the time of the ultrasonic is 20-30 min. The temperature of silane modification in S2 is 50-65 , and the time of silane modification is 1-3h.

9. The method for preparing calcium carbonate filler particles according to claim 7, characterized in that, The temperature of stirring in S3 is 25-40 The time of stirring is 1-2h, and the stirring speed is 200-400rpm. The temperature of mixing in S4 is 25-40 The time of mixing is 20-40 min.

10. Use of the calcium carbonate filler particles according to any one of claims 1-6 in the preparation of environmentally friendly box materials.

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