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CN-122008668-A - Anti-tearing polyester dental coating film containing nano antibacterial layer and preparation method thereof

CN122008668ACN 122008668 ACN122008668 ACN 122008668ACN-122008668-A

Abstract

The invention discloses a tear-resistant polyester dental coating film containing a nano antibacterial layer and a preparation method thereof, wherein the dental coating film adopts a three-layer composite structure comprising an outer layer, an intermediate layer and an inner layer, the outer layer consists of PETG, TPU, nano cellulose crystals and a compatilizer, excellent toughness and tear resistance are given to a film material, the intermediate layer is a high-rigidity supporting layer consisting of PCTG and a toughening agent, the inner layer is an antibacterial layer formed by carrying surface modified nano zinc oxide and nano silicon dioxide on photo-curing waterborne polyurethane, the preparation method comprises the steps of S1 respectively preparing master batches and antibacterial liquid of each layer, S2 and three layers of co-extrusion casting to form a base film, and S3 firmly composites the nano antibacterial layer on the surface of the base film through micro gravure coating and ultraviolet curing technology.

Inventors

  • XUE FENG
  • CHEN PEIYUAN
  • SHEN CHUNYAO

Assignees

  • 无锡上美新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260211

Claims (9)

  1. 1. The tear-resistant polyester dental coating film containing the nano antibacterial layer is characterized by comprising a three-layer composite structure consisting of an outer layer, a middle layer and an inner layer, wherein the outer layer is composed of, by weight, 70-85 parts of PETG copolyester, 15-30 parts of thermoplastic polyurethane TPU, 3-8 parts of nanocellulose crystal and 1-5 parts of compatilizer, the middle layer is composed of 85-100 parts of PCTG copolyester and 5-10 parts of toughener, and the inner layer is composed of 80-90 parts of photo-curing medical waterborne polyurethane WPU, 5-15 parts of nano zinc oxide with the surface modified by a silane coupling agent, 5-10 parts of nano silicon dioxide, 0.5-2 parts of photoinitiator 1173 and 1-3 parts of flatting agent.
  2. 2. The tear-resistant polyester dental floss film containing a nano antibacterial layer according to claim 1, wherein the toughening agent is MBS resin, the particle size of the nano cellulose crystal is 50-200 nanometers, the length-diameter ratio is 20-100, and the compatilizer is maleic anhydride grafted PETG.
  3. 3. The tear resistant polyester dental mouthpiece film containing nano-antimicrobial layers of claim 1, wherein the thickness ratio of the outer layer, the intermediate layer, and the inner layer is 1-1.5:2-3:0.05-0.1.
  4. 4. The method for preparing the tear-resistant polyester dental floss film containing the nano-antibacterial layer according to claim 1, which is characterized by comprising the following steps: S1, preparing master batches of all layers: s1.1, preparing outer master batches: Placing PETG copolyester, thermoplastic polyurethane TPU, nanocellulose crystals and a compatilizer in a high-speed mixer according to the proportion, drying and mixing for 2-4 hours at 60-80 ℃, and then carrying out melt blending, extrusion and granulation by a first double-screw extruder to obtain outer-layer master batch; s1.2, preparing intermediate layer master batches: Drying and mixing PCTG copolyester and a toughening agent for 1-3 hours at 50-70 ℃ according to the proportion, and then carrying out melt blending, extrusion and granulation by a second double-screw extruder to obtain intermediate layer master batch; S1.3, preparing an inner layer antibacterial solution: Dispersing nano zinc oxide in absolute ethyl alcohol, wherein the mass volume ratio of the nano zinc oxide to the absolute ethyl alcohol is 1:5-10, adding a silane coupling agent KH-550 accounting for 3-8% of the weight of the nano zinc oxide, magnetically stirring and refluxing for 2-4 hours at 60-70 ℃, and then centrifuging, washing and drying to obtain the surface modified nano zinc oxide; Adding the surface modified nano zinc oxide and nano silicon dioxide into photo-curing medical grade water-based polyurethane according to the proportion, adding a photoinitiator 1173 and a flatting agent, and performing ultrasonic dispersion for 30-60 minutes under the power of 500-800W by adopting an ultrasonic cell grinder to obtain an inner layer antibacterial solution; S2, three-layer coextrusion casting film forming: Respectively putting the outer layer master batch obtained in the step S1.1 and the middle layer master batch obtained in the step S1.2 into corresponding extruders of a three-layer co-extrusion casting film machine, setting the temperature of each section of the outer layer extruder to be 200-240 ℃, setting the temperature of each section of the middle layer extruder to be 190-230 ℃, and carrying out casting cooling shaping after three-layer composite melt lamination on a casting roller at 120-150 ℃ through a T-shaped die head to obtain a base film; S3, coating and curing the nano antibacterial layer: And (3) uniformly coating the inner antibacterial liquid prepared in the step (S1.3) on the inner surface of the base film in the step (S2) to obtain a wet film material, and then carrying out ultraviolet light curing on the wet film material to obtain the anti-tearing polyester dental coating film containing the nano antibacterial layer.
  5. 5. The method for preparing a tear-resistant polyester dental coating film containing a nano-antibacterial layer according to claim 4, wherein the first twin-screw extruder in S1.1 is divided into five temperature-controlled areas from a feed inlet to a die head, the temperature is set to be 190-200 ℃ in one area, 200-210 ℃ in two areas, 210-220 ℃ in three areas, 220-225 ℃ in four areas and 225-230 ℃ in five areas, and the screw speed of the first twin-screw extruder is 200-400 rpm.
  6. 6. The method for preparing a tear-resistant polyester dental coating film containing a nano-antibacterial layer according to claim 4, wherein the second twin-screw extruder in S1.2 is divided into five temperature-controlled areas from a feed inlet to a die head, the temperature is set to be 220-230 ℃ in the first area, 230-240 ℃ in the second area, 240-250 ℃ in the third area, 250-255 ℃ in the fourth area and 255-260 ℃ in the fifth area, and the screw speed of the second twin-screw extruder is 200-400 rpm.
  7. 7. The method for preparing a tear-resistant polyester dental floss film comprising a nano-antibacterial layer according to claim 4, wherein the wet film thickness of the wet film material of S3 is controlled to be 10-30 μm.
  8. 8. The method for preparing the anti-tearing polyester dental floss film containing the nano-antibacterial layer according to claim 4, wherein the ultraviolet curing method is characterized in that the wet film material passes through an ultraviolet curing device at a speed of 3-10 m/min, and ultraviolet light with a wavelength of 365nm and an intensity of 800-1200mJ/cm 2 is adopted for irradiation curing under a nitrogen protection environment, so that the anti-tearing polyester dental floss film containing the nano-antibacterial layer is obtained.
  9. 9. The method for preparing a tear-resistant polyester dental coating film containing a nano-antibacterial layer according to claim 4, wherein the aspect ratio of the screws of the first twin-screw extruder and the second twin-screw extruder is 40-48:1 respectively.

Description

Anti-tearing polyester dental coating film containing nano antibacterial layer and preparation method thereof Technical Field The invention relates to the technical field of preparation of polyester dental films, in particular to a tearing-resistant polyester dental film containing a nano antibacterial layer and a preparation method thereof. Background The polyester dental floss film is used as a common orthodontic auxiliary device and is mainly used for covering the surface of the dental floss, thereby playing roles of protecting mucous membrane, preventing scratch and improving wearing comfort. With the increasing demands of people on oral health and hygiene, the dental floss film not only needs to have good optical transparency and fit, but also is expected to have durable antibacterial performance and enough mechanical strength to adapt to complex stress conditions in daily wear. The polyester dental coating film in the current market is mostly made of common PET or TPU and other materials through a tape casting or calendaring process. In order to improve the antibacterial performance, a common technical means is to blend and add some organic antibacterial agents such as triclosan or quaternary ammonium salt compounds into a polyester matrix. In the aspect of enhancing mechanical properties, the toughness is improved mainly by adjusting the molecular weight of the material or performing a biaxial stretching process. However, such conventional physical blending and processing methods have inherent limitations in achieving functional integration. The key problems which are difficult to solve in the prior art are that firstly, the physically blended organic antibacterial agent is easy to release rapidly at the initial stage of use, so that the antibacterial effective period is short, the biological safety risk possibly exists, the long-term, stable and safe antibacterial effect is difficult to realize, and secondly, although the toughness can be improved to a certain extent by the conventional reinforcing means, irreversible tearing of the material still easily occurs when the complex stress in the oral cavity is dealt with, and the tear resistance and the light transmittance are often difficult to be compatible, so that the durability and the reliability of the product are limited. Disclosure of Invention The invention provides a tear-resistant polyester dental floss film containing a nano antibacterial layer and a preparation method thereof, aiming at the technical problems that the existing polyester dental floss film is difficult to realize long-acting, safe antibacterial and simultaneously has excellent tear resistance and high optical transparency. The technical scheme is that the anti-tearing polyester dental coating film containing the nano antibacterial layer is of a three-layer composite structure composed of an outer layer, an intermediate layer and an inner layer, wherein the outer layer is composed of, by weight, 70-85 parts of PETG copolyester, 15-30 parts of thermoplastic polyurethane TPU, 3-8 parts of nanocellulose crystal and 1-5 parts of compatilizer, the intermediate layer is composed of 85-100 parts of PCTG copolyester and 5-10 parts of toughener, and the inner layer is composed of 80-90 parts of photo-curing medical grade water-based polyurethane WPU, 5-15 parts of nano zinc oxide with a surface modified by a silane coupling agent, 5-10 parts of nano silicon dioxide, 0.5-2 parts of photoinitiator 1173 and 1-3 parts of flatting agent. The inner layer thoroughly abandons the organic antibacterial agent with biological safety risk, and constructs a brand new inorganic and organic composite antibacterial system of surface modified nano zinc oxide, nano silicon dioxide and photo-curing WPU. The material system design based on synergistic toughening and isolation slow release constructs a long-acting and safe antibacterial layer, and brings the technical effect of synchronously improving various performance indexes. Further, the toughening agent adopts MBS resin, the particle size of the nano cellulose crystal is 50-200 nanometers, the length-diameter ratio is 20-100, and the compatilizer is maleic anhydride grafted PETG. The MBS resin is selected to toughen the PCTG, so that the brittleness is effectively improved while the high transparency is maintained. The particle size and the length-diameter ratio of the nanocellulose are precisely limited, so that the nanocellulose can be used as an efficient nano reinforcing point to remarkably improve the toughness of an outer layer, and the transparency is perfectly maintained because the size is far smaller than the wavelength of light. The maleic anhydride grafted PETG is designated as a compatilizer, the interfacial compatibility of the nanocellulose and a polymer matrix is greatly improved through chemical reaction, agglomeration is avoided, and the reinforcing effect is fully exerted. The three are cooperated to realize the core with high tra