High brightness cpp mirror film

Abstract

The utility model provides a kind of high brightness CPP mirror film, from bottom to top include base layer, brightening layer, aluminizing layer and wear-resistant layer in order, base layer is by cast polypropylene resin melt extrusion, cast cooling forming, brightening layer is coated on the upper surface of base layer, aluminizing layer is evaporated on the surface of brightening layer, wear-resistant layer covers in aluminizing layer outer surface.The utility model can enhance the scratch resistance, gloss and mirror reflectivity of film by multilayer composite structure;Using the thermal stability of CPP casting, it can solve the problem of coating cracking and wrinkling caused by substrate shrinkage of traditional aluminized film;Through the periodic gradient density design of aluminizing layer and discoloration dye filling, to improve the limitation of traditional coating single light effect, enhance dynamic optical level.

Description

Technical Field

[0001] This utility model relates to the field of polymer film technology, and in particular to a high-brightness CPP mirror film. Background Technology

[0002] CPP film possesses excellent heat-sealing properties, flexibility, and chemical compatibility, leading to its increasing use in various fields. Patent document CN220466296U discloses a high-brightness polypropylene packaging film, relating to the field of packaging film technology. It includes a heat-sealing layer with a reinforcing layer on top. The reinforcing layer has a coating structure on its surface, and an outer protective film is placed on top of the coating structure. The coating structure includes an electroplated layer and electroplating pits. The electroplated layer is fixedly disposed on top of the reinforcing layer, and multiple electroplating pits are evenly distributed on the top of the electroplated layer. This invention significantly enhances the gloss of the polypropylene film, modifies the halo pattern, and protects the coating, greatly extending its service life and making it more convenient to use.

[0003] In the above solutions, the film improves gloss through electroplating. However, the coating usually has poor abrasion resistance and is easily scratched by mechanical friction, resulting in a decrease in mirror effect. The coating structure easily causes monotonous mirror reflection and lacks dynamic optical layering. At the same time, because the thermal shrinkage rate of BOPP film is higher than that of the coating material, thermal stress mismatch between the substrate and the coating can easily cause problems such as coating cracking and wrinkling in high-temperature processing or use environments. Therefore, it is necessary to provide a high-brightness CPP mirror film to solve the shortcomings of the existing technology. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a high-brightness CPP mirror film.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A high-brightness CPP mirror film comprises, from bottom to top, a base layer, a brightening layer, an aluminum plating layer, and a wear-resistant layer. The base layer is formed by melt extrusion of cast polypropylene resin, casting and cooling. The brightening layer is coated on the upper surface of the base layer. The aluminum plating layer is vapor-deposited on the surface of the brightening layer. The wear-resistant layer covers the outer surface of the aluminum plating layer.

[0007] The present invention is further configured such that the base layer contains nano-talc powder to reduce the surface roughness of the substrate.

[0008] The present invention is further configured such that the brightening layer is composed of a blend of nano-titanium dioxide and polymethyl methacrylate.

[0009] The present invention is further configured such that the brightening layer contains a fluorescent whitening agent OB-1.

[0010] The present invention is further configured such that the aluminum plating layer has periodically arranged pits and protrusions.

[0011] The present invention is further configured such that the density of the pits and protrusions varies in a gradient in the lateral direction, forming a gradual dynamic halo effect.

[0012] The present invention is further configured such that the pit is filled with a transparent color-changing dye, and the color changes with the viewing angle to present an iridescent effect.

[0013] The present invention is further configured such that the wear-resistant layer is composed of UV-cured acrylate resin and nano-alumina particles.

[0014] In summary, this utility model has the following beneficial effects:

[0015] 1. This utility model, through its multi-layer composite structure, can enhance scratch resistance, gloss, and specular reflectivity.

[0016] 2. This utility model utilizes the thermal stability of CPP casting to solve the problems of coating cracking and wrinkling caused by substrate shrinkage in traditional aluminized films.

[0017] 3. This utility model improves the limitation of the single light effect of traditional coatings and enhances the dynamic optical layering by using a periodic gradient density design of the aluminum coating layer and color-changing dye filling. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] In the diagram, 1. base layer, 2. brightening layer, 3. aluminum plating layer, 4. wear-resistant layer. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0021] Example 1:

[0022] In this embodiment, as Figure 1 As shown, the high-brightness CPP mirror film proposed in this utility model includes, from bottom to top, a base layer 1, a brightening layer 2, an aluminum plating layer 3, and a wear-resistant layer 4. The base layer is formed by melt extrusion of cast polypropylene resin, casting and cooling. The brightening layer is coated on the upper surface of the base layer, the aluminum plating layer is vapor-deposited on the surface of the brightening layer, and the wear-resistant layer covers the outer surface of the aluminum plating layer.

[0023] In this embodiment, the base layer is further configured to contain nano-talc powder to reduce the surface roughness of the substrate.

[0024] In this example, the base layer is a CPP base layer with a thickness of 20-50 μm. Nano-talc powder with a particle size ≤100 nm is added to the CPP base layer raw material. After the fine particles are uniformly dispersed in the polypropylene matrix, they can fill the voids and defects inside the material, reducing the micro-unevenness of the surface. This makes the film surface smoother, reduces surface roughness, thereby reducing light scattering and improving the gloss and transparency of the film. Lower surface roughness means higher specular reflectivity, which is very important for applications requiring high brightness and a mirror effect. At the same time, the addition of nano-talc powder can also improve processing performance and enhance mechanical properties, such as thermal stability in processing performance and hardness and wear resistance in mechanical properties.

[0025] Example 2:

[0026] In this embodiment, as Figure 1 As shown, the brightening layer is composed of a blend of nano-titanium dioxide and polymethyl methacrylate.

[0027] In this embodiment, the brightening layer is further configured to contain a fluorescent whitening agent OB-1.

[0028] In this example, when nano-titanium dioxide particles are uniformly dispersed in a polymethyl methacrylate matrix, a "high-low refractive index interface" is formed. Light undergoes multiple refractions and reflections on the surface of the titanium dioxide particles, which can significantly improve the total reflectance of the film. The fluorescent whitening agent OB-1 added to the brightening layer is mainly intended to significantly enhance the visual brightness and color performance of the film through optical complementary effects and fluorescence excitation mechanisms. CPP substrates are prone to slight oxidation or thermal degradation during processing or long-term use, resulting in yellowing of the film. The molecular structure of OB-1 can selectively absorb 365nm ultraviolet light and emit 430-480nm blue light, compensating for the blue light loss caused by the yellowing of the substrate, giving the film a cool white tone, selectively supplementing light, and enhancing whiteness for brightening.

[0029] In this example, the thermal stability of CPP casting can be utilized to avoid the coating cracking problem caused by substrate shrinkage in traditional aluminized films.

[0030] Example 3:

[0031] In this embodiment, as Figure 1 As shown, the aluminum plating layer has periodically arranged pits and protrusions.

[0032] In this embodiment, the density of the pits and protrusions is further configured to vary laterally, forming a gradual dynamic halo effect.

[0033] In this example, the CPP substrate surface coated with the brightening layer is first subjected to plasma cleaning to remove surface contaminants and improve coating adhesion. A laser-engraved embossing roller is then used to imprint micron-level pre-marks on the brightening layer surface, forming a "negative template" for aluminum plating. In a vacuum coating machine (currently available technology), aluminum wire is heated to its evaporation temperature, and aluminum vapor is deposited onto the pre-marked surface, precisely filling the pits and covering the protrusions, forming a micro-relief aluminum plating layer that replicates the pre-marks. The pit distribution density of the embossing roller gradually changes laterally along the roller surface (e.g., from 100 pits / mm). 2 Up to 500 pieces / mm 2 This allows the density of the micro-relief structure of the aluminum layer after vapor deposition to change in a gradient, and the reflected light produces a dynamic interference halo, thereby improving the limitation of the single light effect of traditional coatings and enhancing the dynamic optical layering.

[0034] In this embodiment, the pit is further configured to be filled with a transparent color-changing dye, and the color changes with the viewing angle to present an iridescent effect, which can enhance the dynamic optical layering.

[0035] Example 4:

[0036] In this embodiment, as Figure 1 As shown, the wear-resistant layer is composed of UV-cured acrylate resin and nano-alumina particles.

[0037] In this example, the wear-resistant layer is a wear-resistant coating. The wear-resistant coating is applied to the surface of the aluminum plating layer. The UV-cured acrylic resin has rapid curing characteristics and can ensure transparency. It can cure quickly at low temperature to avoid thermal damage to the aluminum plating layer. The nano-coating precisely covers the micro-embossed pits and protrusions to prevent structural collapse and enhance impact and scratch resistance, thereby protecting the aluminum plating layer.

[0038] In the description of this utility model, it should be noted that when terms such as "upper," "lower," "inner," "outer," "left," and "right" appear to indicate orientation or positional relationships, they should be understood as being based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product of this utility model is in use, or the orientation or positional relationships commonly understood by those skilled in the art. These terms are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, when terms such as "first" and "second" appear, they are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, it should also be noted that unless otherwise explicitly specified and limited, terms such as "installation," "setting," and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

Claims

1. A high-brightness CPP mirror film, characterized in that, From bottom to top, it includes a base layer, a brightening layer, an aluminum plating layer, and a wear-resistant layer. The base layer is formed by melt extrusion of cast polypropylene resin, casting and cooling. The brightening layer is coated on the upper surface of the base layer. The aluminum plating layer is vapor-deposited on the surface of the brightening layer. The wear-resistant layer covers the outer surface of the aluminum plating layer.

2. The high-brightness CPP mirror film according to claim 1, characterized in that, The aluminum plating layer has periodic pits and protrusions.

3. The high-brightness CPP mirror film according to claim 2, characterized in that, The density of the pits and bumps varies horizontally, creating a gradual dynamic halo effect.

4. The high-brightness CPP mirror film according to claim 2, characterized in that, The pits are filled with transparent color-changing dye, and the color changes with the viewing angle, exhibiting an iridescent effect.

Images