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CN-121182250-B - Expandable polystyrene antibacterial coating agent and application method thereof

CN121182250BCN 121182250 BCN121182250 BCN 121182250BCN-121182250-B

Abstract

The application relates to the field of polymer material auxiliaries, and particularly discloses an expandable polystyrene antibacterial coating agent and an application method thereof. The expandable polystyrene antibacterial coating agent comprises a material A and a material B, wherein the material A comprises the following raw materials, by weight, 10-20 parts of mono-diglyceride fatty acid ester, 12-20 parts of glyceryl tristearate, 10-18 parts of stearate, 0.5-1.5 parts of ethylene bis stearamide, 20-35 parts of nano silicon dioxide and 45-65 parts of antibacterial agent, and the material B is a polyethylene wax-carbon nano tube composite emulsion, wherein the polyethylene wax-carbon nano tube composite emulsion comprises polyethylene wax and carbon nano tubes in a mass ratio of 5-10:100. The antibacterial coating agent is used for preventing adhesion and agglomeration of different types of polystyrene particles, increases the lubricity and fluidity of the particles, simultaneously endows the particles with excellent antibacterial property, and expands the application of the foamed particles in the fields of food contact materials, medical appliances and the like.

Inventors

  • Ren Minming
  • FENG YANYAN

Assignees

  • 日照国恩化学有限公司

Dates

Publication Date
20260505
Application Date
20250929

Claims (9)

  1. 1. The expandable polystyrene antibacterial coating agent is characterized by comprising a material A and a material B, wherein the material A comprises the following raw materials, by weight, 10-20 parts of mono-diglyceride, 12-20 parts of glyceryl tristearate, 10-18 parts of stearate, 0.5-1.5 parts of ethylene bis-stearamide, 20-35 parts of nano silicon dioxide and 45-65 parts of antibacterial agent, and the material B is a polyethylene wax-carbon nano tube composite emulsion, wherein the polyethylene wax-carbon nano tube composite emulsion comprises polyethylene wax and carbon nano tubes in a mass ratio of 5-10:100; The preparation method of the polyethylene wax-carbon nano tube composite emulsion comprises the following steps: Completely hot-melting polyethylene wax at 120-130 ℃, adding deionized water, homogenizing and emulsifying to obtain polyethylene wax emulsion; adding the carbon nano tube into deionized water, performing ultrasonic treatment, adding cellulose nano crystals, performing ultrasonic dispersion, and filtering to obtain a pretreated carbon nano tube; Adding the pretreated carbon nano tube into the polyethylene wax emulsion, and uniformly stirring to obtain the composite emulsion.
  2. 2. The expandable polystyrene antibacterial coating agent of claim 1, wherein the concentration of the polyethylene wax emulsion is 10 to 15%.
  3. 3. The expandable polystyrene antibacterial coating agent of claim 1, wherein the mass ratio of the cellulose nanocrystals to the carbon nanotubes is 1-2:1.
  4. 4. The expandable polystyrene antibacterial coating agent of claim 3, wherein the pretreated carbon nanotubes are subjected to the following pretreatment before being added to the polyethylene wax emulsion: adding polyethylenimine, acrylic acid, N-methylene bis-vinylamide, quaternary ammonium salt chitosan and a photoinitiator into deionized water, and uniformly mixing to obtain a treatment solution; adding the pretreated carbon nano tube into the treatment liquid, performing ultrasonic dispersion, filtering, irradiating with ultraviolet light, soaking in sodium carbonate solution, filtering and washing.
  5. 5. The expandable polystyrene antibacterial coating agent of claim 1, wherein the antibacterial agent is a silver-loaded silicate.
  6. 6. The expandable polystyrene antibacterial coating agent of claim 5, wherein the silver-loaded silicate is pretreated by: Adding oleic acid into ethanol to prepare oleic acid-ethanol solution, then dropwise adding silver-carrying silicate, stirring while dropwise adding, and then vacuum drying, wherein the mass ratio of oleic acid to silver-carrying silicate is 0.03-0.05:1.
  7. 7. The expandable polystyrene antibacterial coating agent of claim 1, wherein the stearate is at least one selected from the group consisting of zinc stearate, magnesium stearate, sodium stearate, aluminum stearate, and calcium stearate.
  8. 8. The method for applying the expandable polystyrene antibacterial coating agent according to any one of claims 1 to 7, which is characterized by comprising the following steps: uniformly mixing tristearin, an antibacterial agent, a mono-diglyceride fatty acid ester, nano silicon dioxide, stearate and ethylene bis-stearamide to prepare a material A; mixing expandable polystyrene particles with the material A for 30-50min, spraying polyethylene wax-carbon nano tube composite emulsion, and drying.
  9. 9. The application method of the expandable polystyrene antibacterial coating agent according to claim 8, wherein the amount of the material A is 0.1-0.5% of the mass of the expandable polystyrene particles, and the amount of the material B is 0.05-0.25% of the mass of the expandable polystyrene particles.

Description

Expandable polystyrene antibacterial coating agent and application method thereof Technical Field The application relates to the technical field of polymer material assistants, in particular to an expandable polystyrene antibacterial coating agent and an application method thereof. Background The foamed polystyrene foam plastic product is a valuable insulating, heat preserving and packaging buffer material, and has the advantages of low water absorption, excellent dielectric property, high mechanical strength and the like, and has very wide application in building walls, roof heat preservation, composite board heat preservation, cold storage, air conditioning, vehicle and ship heat preservation and heat insulation, floor heating, decoration engraving and the like. In the pre-foaming process of the expandable polystyrene, when the temperature reaches more than 90 ℃, the polystyrene reaches an elastic state, static electricity exists on the surfaces of particles, physical contact among the particles, loss of a foaming agent and an auxiliary agent and the like are caused, so that the polystyrene particles are easy to adhere, agglomerate, not easy to demould and the like, the fluidity of the polystyrene can be influenced, uneven foaming can be caused in the foaming process, gaps are formed among foam particles filled in a mold due to uneven foaming, and the use of a final product is influenced. In addition, the prior expandable polystyrene mostly contains a foaming agent pentane, and in the industrial method, the dosage of the foaming agent is 6-7 percent of the weight of the styrene monomer, but pentane foaming agent is easy to cause adverse effect on the environment. In order to avoid mutual adhesion and agglomeration of polystyrene particles during foaming, coating agents are often added to the surfaces of the particles, the traditional coating agents, namely monoglyceride, glyceryl tristearate and zinc stearate, have poor compatibility with a polystyrene matrix, are easy to migrate to the surface of the material and escape, have an insignificant effect of improving the agglomeration and adhesion of the polystyrene particles, cannot reduce the volatilization of pentane, have poor antibacterial capacity, and are limited in the fields with high requirements on hygienic properties, such as food packaging, medical appliances and the like. Disclosure of Invention In order to increase the fluidity of the expandable polystyrene particles, reduce the caking and adhesion of the expandable polystyrene particles, reduce the volatilization of pentane foaming agents and increase the antibacterial property of the expandable polystyrene particles, so that the expandable polystyrene particles are applied to the field with high requirements on sanitary safety. In a first aspect, the application provides an expandable polystyrene antibacterial coating agent, which adopts the following technical scheme: The expandable polystyrene antibacterial coating agent comprises, by weight, 10-20 parts of a mono-diglyceride fatty acid ester, 12-20 parts of glyceryl tristearate, 10-18 parts of stearate, 0.5-1.5 parts of ethylene bis stearamide, 20-35 parts of nano silicon dioxide, 45-65 parts of an antibacterial agent and 3-5 parts of a polyethylene wax-carbon nano tube composite emulsion, wherein the polyethylene wax-carbon nano tube composite emulsion comprises polyethylene wax and carbon nano tubes in a mass ratio of 5-10:100. By adopting the technical scheme, the nano silicon dioxide has huge specific surface area and higher surface energy, zinc stearate molecules can be preferentially adsorbed and fixed on the surface, and the zinc stearate plays a role in lubricating the nano silicon dioxide, so that the zinc stearate can be more easily and uniformly spread on the surface of the expandable polystyrene particles, and the nano silicon dioxide provides a firm and non-migration physical barrier, so that the lubricating property of stearate is utilized, the migration problem of the stearate is solved by means of nano silicon dioxide powder, and the anti-adhesion effect and durability are greatly improved; the polyethylene wax is an excellent anti-sticking agent, which is dispersed in water, water evaporates after spraying, the polyethylene wax is physically adsorbed on the EPS surface in the form of fine solid particles, a micropore and discontinuous surface layer is formed on the surface of the expandable polystyrene particles, and a sealing film is not formed, so that when the expandable polystyrene particles are expanded, the foaming agent can easily escape from gaps among the wax particles, expansion is not hindered, and the adhesive agent has excellent anti-caking property and lubricating property, carbon nano tubes form a layer of rough physical barrier on the surface of the polystyrene particles under the adhesion of the polyethylene wax, the contact area between the polystyrene particles is reduced, the adhesion caused by softenin