A high-temperature resistant plush-touch matte masterbatch, its preparation method, and a high-temperature resistant plush-touch BOPP matte label film.

Abstract

This invention relates to a high-temperature resistant plush-touch matte masterbatch, its preparation method, and a high-temperature resistant plush-touch BOPP matte label film, belonging to the technical field of matte masterbatches. The high-temperature resistant plush-touch matte masterbatch of this invention comprises: 42-48 wt% high-density polyethylene, 24-28 wt% high isotactic polypropylene, and 25-35 wt% ethylene-octene copolymer graft copolymer polypropylene. The film layer formed by the high-temperature resistant plush-touch matte masterbatch has high-temperature resistance, a plush-touch feel, and excellent matte visual effect, making it suitable for high-end label films (such as matte label films). Simultaneously, the matte uniformity of the film layer is good. Furthermore, the high-temperature resistance of the high-temperature resistant plush-touch matte masterbatch makes the film layer (or thin film) less prone to wrinkling during heat sealing, synergistically protecting the matte effect.

Description

Technical Field

[0001] This invention relates to the field of matte masterbatch technology, and in particular to a high-temperature resistant plush-touch matte masterbatch, its preparation method, and a high-temperature resistant plush-touch BOPP matte label film. Background Technology

[0002] Biaxially oriented polypropylene film, or BOPP film for short, is most commonly used in high-end packaging. In the production process of BOPP matte film, 100% matte material is added to the surface of the co-extruded film. After biaxial stretching, the film surface is roughened, resulting in diffuse reflection of light and achieving a matte (glossy) effect. However, commercially available matte films often suffer from uneven or insufficient matte finish on both sides, resulting in a cloudy matte appearance. This affects the overall quality of the matte film, making it unsuitable for high-end packaging.

[0003] As BOPP matte film becomes increasingly widely used in the packaging industry, and with rising living standards, people are placing higher demands on consumer product packaging. This leads to increasingly stringent requirements for BOPP matte film and matte masterbatch. For special-purpose packaging, such as high-end gift boxes, wine boxes, and e-cigarette product labels, a high-grade BOPP film is needed to provide consumers with a luxurious and upscale experience. This requires a high-quality BOPP film that offers high-temperature resistance, a velvety feel, and uniform matte visual effect. Therefore, a matte masterbatch is also needed to provide the film with high-temperature resistance, a velvety feel, and uniform matte finish. Summary of the Invention

[0004] Based on this, the purpose of this invention is to provide a high-temperature resistant plush-touch matte masterbatch, its preparation method, and a high-temperature resistant plush-touch BOPP matte label film. The film layer formed by the high-temperature resistant plush-touch matte masterbatch has high-temperature resistance, a plush-touch feel, and excellent matte visual effect, making it suitable for high-end label films (such as matte label films). At the same time, the matte uniformity of the film layer is good. In addition, the high-temperature resistance of the high-temperature resistant plush-touch matte masterbatch makes the film layer (or thin film) less prone to wrinkling during heat sealing, thus synergistically protecting the matte effect.

[0005] A high-temperature resistant, plush-feel matte masterbatch comprises 42-48 wt% high-density polyethylene, 24-28 wt% high isotactic polypropylene and 25-35 wt% ethylene-octene copolymer graft copolymer polypropylene.

[0006] After years of research, the inventors discovered that existing matte masterbatches can hardly achieve a plush feel in the film. This is because the formation of a plush feel usually requires the addition of fluff powder or fluff material to the matte material to give the film a plush feel. However, fluff powder (such as thermoplastic elastomers) has poor compatibility with polypropylene, which makes the produced film prone to pitting. Furthermore, since the melting point of some fluff powders is much lower than that of polypropylene, they are prone to premature softening or decomposition, which can easily cause them to stick to the rollers during production, affecting extrusion stability and production smoothness.

[0007] The high-temperature resistant plush-feel matte masterbatch of the present invention comprises 42-48 wt% high-density polyethylene, 24-28 wt% high isotactic polypropylene and 25-35 wt% ethylene-octene copolymer graft copolymer polypropylene. On the one hand, high-density polyethylene has high crystallinity and a fast crystallization rate, forming an "island phase" structure, while high isotactic polypropylene has a relatively slow crystallization rate, forming a "marine phase" structure. Furthermore, the copolymer polypropylene segments in the ethylene-octene copolymer graft copolymer polypropylene exhibit good compatibility with high isotactic polypropylene, and the ethylene-octene copolymer segments facilitate the formation of "island phase" micro-regions in the film layer. The synergistic effect of these three factors results in a micron-level uneven structure on the surface of the film layer formed by the high-temperature resistant plush-feel matte masterbatch, causing diffuse reflection of incident light and significantly reducing gloss, thus achieving excellent matting effect. On the other hand, the ethylene-octene copolymer graft copolymer polypropylene improves the compatibility of each component and enhances production smoothness. Due to the low melt viscosity of the ethylene-octene copolymer segments, the melt flowability of the ethylene-octene copolymer graft homopolymer polypropylene is superior to that of high isotactic polypropylene. During the biaxial stretching process of the film layer formed by the high-temperature resistant plush-feel matte masterbatch, this facilitates melt distribution, further resulting in a more uniform phase domain distribution and better matting uniformity. On the other hand, the ethylene-octene copolymer graft copolymer polypropylene forms a micron-scale elastic "island" micro-protrusion structure on the film surface, giving the film surface a soft and resilient feel. These micro-protrusion structures generate slight friction and rebound when touched by fingers, simulating a "fluffy" feel. In addition, the ethylene-octene copolymer graft copolymer polypropylene has a good anchoring effect in this system, which can prevent the ethylene-octene copolymer graft copolymer polypropylene from migrating or falling off, making the fluffy feel stable and lasting. On the other hand, high-density polyethylene and high isotactic polypropylene have high melting points and high heat distortion temperatures; while the ethylene-octene copolymer graft copolymer polypropylene, due to its grafting structure, is not prone to migration, softening, or collapse at high temperatures, thus buffering thermal stress and delaying thermal oxidative degradation. This allows the film layer formed by the high-temperature resistant plush-feel matte masterbatch to maintain surface structural stability under high-temperature conditions, without gloss recovery or surface stickiness, exhibiting high-temperature resistance. The high-temperature resistance of the high-temperature resistant plush-feel matte masterbatch also prevents wrinkling of the film layer (or thin film) during heat sealing, synergistically protecting the matte effect. The high-temperature resistant plush-feel matte masterbatch of this invention achieves excellent high-temperature resistance, matte performance, and plush-feel functionality in one, making it suitable for high-end packaging labels, tactile films, and other applications requiring surface texture, heat resistance, and matte finish.

[0008] The high-temperature resistant plush-feel matte masterbatch of this invention, by adding 25-35 wt% of the ethylene-octene copolymer grafted copolymer polypropylene, endows the film layer with properties that combine high temperature resistance, uniform matting, and a plush feel, avoiding performance imbalance. If the content of the ethylene-octene copolymer grafted copolymer polypropylene in the high-temperature resistant plush-feel matte masterbatch is less than 25 wt%, the surface micro-protrusion structure of the film layer formed by the high-temperature resistant plush-feel matte masterbatch is insufficient, the matting performance decreases, and problems such as local reflection or uneven matting may occur. In addition, the reduction of the surface micro-protrusion structure causes the film layer surface to become softer but less plush, the plush feel is significantly weakened, the touch is dry, and the "plush" feel is lost. If the content of the ethylene-octene copolymer graft copolymer polypropylene in the high-temperature resistant plush-feel matte masterbatch is higher than 35 wt%, the surface of the film layer formed by the high-temperature resistant plush-feel matte masterbatch will be excessively softened, the micro-convex structure will collapse, the surface will tend to be flat, the gloss will be restored but the uniformity of matte will be poor, and the touch will be sticky; in addition, the high-temperature resistance will be severely weakened, and it will be easy to deform and become sticky at high temperatures; during production, the tensile stress will be unevenly distributed, affecting the smoothness of production.

[0009] Furthermore, the high-isotactic polypropylene in the high-temperature resistant plush-feel matte masterbatch of this invention imparts higher tensile strength, rigidity, and tear resistance to the film formed by the masterbatch, and also provides good heat resistance. Utilizing the high-temperature resistance of the masterbatch, the film (or thin film) is less prone to wrinkling during heat sealing, thus synergistically protecting the matte effect. This invention, through the combination design of high-isotactic polypropylene, high-density polyethylene, and the ethylene-octene copolymer graft copolymer polypropylene in the high-temperature resistant masterbatch, balances the rigidity and toughness of the film formed by the masterbatch, reducing the risk of film breakage during slitting, minimizing fisheye problems, and improving production smoothness.

[0010] Furthermore, the grafting rate of the ethylene-octene copolymer in the ethylene-octene copolymer graft copolymer polypropylene is 0.8-1.2%. Limiting the grafting rate of the ethylene-octene copolymer in the ethylene-octene copolymer graft copolymer polypropylene to 0.8-1.2% is a key factor in achieving the desired high-temperature resistant, plush-touch matte masterbatch while maintaining high temperature resistance, a plush touch, and uniform matte finish. If the grafting rate of the ethylene-octene copolymer is too low, i.e., below the above range, the compatibility of the ethylene-octene copolymer graft copolymer polypropylene within the system will be insufficient. The film layer formed by the high-temperature resistant, plush-touch matte masterbatch will have a rough surface but uneven matte finish and a rough feel, which is not conducive to the formation of a high-grade, three-dimensional plush touch. Simultaneously, it will lead to poor melt flowability of the ethylene-octene copolymer graft copolymer polypropylene, which is not conducive to producing a good matte effect, and may even cause film breakage during the film formation process. If the grafting rate of the ethylene-octene copolymer is too high, i.e. higher than the above range, it will cause the melting point of the high-temperature resistant plush-feel matte masterbatch to be too low. On the one hand, this will result in poor temperature resistance of the film formed by the high-temperature resistant plush-feel matte masterbatch. On the other hand, it will increase the melt viscosity of the high-temperature resistant plush-feel matte masterbatch, which will easily cause the roller sticking phenomenon during the production and processing of the film formed, which is not conducive to high-speed automated production. Furthermore, the plush feel of the film will be uneven or even sticky.

[0011] Furthermore, the melt index of the ethylene-octene copolymer graft copolymer polypropylene is 8-10 g / 10 min (230℃, 2.16 kg). Limiting the melt index of the ethylene-octene copolymer graft copolymer polypropylene to this range ensures good compatibility with other components in the high-temperature resistant plush-feel matte masterbatch, guaranteeing good dispersion and uniform melt viscosity during melt blending. This helps ensure the melt processing fluidity of the high-temperature resistant plush-feel matte masterbatch, reducing melt fracture and die exudation during production, and ensuring the matte effect, uniformity, plush feel, and high-temperature resistance of the film formed by the high-temperature resistant plush-feel matte masterbatch. If the melt index of the ethylene-octene copolymer graft copolymer polypropylene is too low, the melt viscosity is too high, and the melt fluidity is poor, leading to difficulties in melt mixing and uneven dispersion during melt blending, resulting in uneven matte finish. If the melt index of the ethylene-octene copolymer graft copolymer polypropylene is too high and the melt viscosity is too low, the low viscosity of the ethylene-octene copolymer graft copolymer polypropylene will severely weaken its compatibility in the system during melt blending, leading to phase separation and uneven matting. In the processing of the high-temperature resistant plush-feel matting masterbatch to form a film layer, the excessively low viscosity will also easily lead to melt cracking, poor stability, affect film formation and surface quality, and destroy the uniformity of the plush-feel.

[0012] Furthermore, the ethylene-octene copolymer contains 65-75 wt% ethylene and 25-35 wt% octene. If the ethylene content is too low or the octene content is too high, the ethylene-octene copolymer becomes highly amorphous, very soft, and has an extremely low modulus. This may result in an overly soft surface microstructure, lacking sufficient resilience to maintain a lasting plush feel, and the touch may be more "sticky." Simultaneously, it will also lead to poor compatibility of the ethylene-octene copolymer graft copolymerized with polypropylene within the system. If the ethylene content is too high or the octene content is too low, the crystallinity of the ethylene-octene copolymer segments increases significantly, becoming harder. The resulting surface microstructure may be too "stiff," weakening the plush feel and making it feel harder; the contribution of flexibility and elasticity decreases, which is not conducive to forming a comfortable plush feel. The ethylene-octene copolymer contains 65-75 wt% ethylene and 25-35 wt% octene. Ethylene-octene copolymers within this range exhibit moderate crystallinity and modulus, providing good elasticity, flexibility, and low-temperature flexibility, which contributes to a soft, resilient, and dry plush feel. Furthermore, this ethylene content range demonstrates good compatibility with isotactic polypropylene and high-density polyethylene.

[0013] Further, the preparation method of the ethylene-octene copolymer graft copolymer polypropylene is as follows: 95-100 parts of copolymer polypropylene and 25-30 parts of ethylene-octene copolymer are vacuum dried at 75-85℃ for 4 h, then premixed with 0.05-0.15 parts of bis(tert-butylperoxyisopropyl)benzene, fed into a twin-screw extruder, with the barrel temperature in five zones being 170 / 180 / 190 / 190 / 185℃, the screw speed being 200 rpm, the vacuum being -(0.08-0.1) MPa, the residence time being 45-60 s, water-cooled pelletizing, and then dried at 75-85℃ for 4 h to obtain the ethylene-octene copolymer graft copolymer polypropylene. In the above preparation method, bis(tert-butylperoxyisopropyl)benzene undergoes thermal decomposition to generate tert-butyloxy radicals, which abstract tert-carbon / allyl hydrogen from the ethylene-octene copolymer and the copolymerized polypropylene, forming POE· and PP· macromolecular radicals. These radicals couple and rearrange, covalently attaching the POE segment to the PP backbone to generate the ethylene-octene copolymer-grafted copolymerized polypropylene. The ethylene-octene copolymer-grafted copolymerized polypropylene exhibits a brush-like structure with a PP backbone and suspended POE side chains, providing the elasticity required for a plush feel. By limiting the above parameters, it is beneficial to ensure that the grafting rate and melt index of the ethylene-octene copolymer-grafted copolymerized polypropylene meet the aforementioned parameter limits.

[0014] Furthermore, the melt index of the high-density polyethylene is 0.05-0.1 g / 10 min (190°C, 21.6 kg). Using high-density polyethylene with the aforementioned melt index facilitates the provision of excellent matting effects in the high-temperature resistant, plush-touch matte masterbatch.

[0015] Furthermore, the isotacticity of the high isotactic polypropylene is 95-97%, and the melt index of the high isotactic polypropylene is 7-8 g / 10 min (230℃, 2.16 kg). By using high isotactic polypropylene with the above-mentioned isotacticity and melt index, it is beneficial to provide excellent high-temperature resistance to the high-temperature resistant plush-touch matte masterbatch.

[0016] The present invention also provides a method for preparing the high-temperature resistant plush-feel matte masterbatch described above, comprising the following steps: mixing the raw materials and adding them to a screw extruder for melt extrusion, and then drawing and granulating them underwater to obtain the high-temperature resistant plush-feel matte masterbatch.

[0017] The present invention also provides a high-temperature resistant plush-touch BOPP matte label film, comprising a matte layer, a core layer, and a lower surface layer arranged in sequence; the matte layer comprises any of the above-mentioned high-temperature resistant plush-touch matte masterbatches; the core layer comprises homopolymer polypropylene, 15-20wt% calcium carbonate pearlescent masterbatch, 2-4wt% ethylene-methyl acrylate copolymer, and 1-3wt% maleic anhydride-grafted homopolymer polypropylene.

[0018] Calcium carbonate is often used in the core layer to impart a pearlescent effect to the film. This invention adds 2-4 wt% ethylene-methyl acrylate copolymer to the core layer, utilizing the ethylene segments to improve the compatibility between the core layer and the matte layer, reduce interfacial tension, and enhance interlayer bonding. The methyl acrylate segments can provide polar ester groups, and during the melt processing of the high-density polyethylene in the matte layer, a small number of oxidation points (such as carbonyl groups, hydroxyl groups, etc.) may appear on the surface of the high-density polyethylene. These oxidation points have a certain polarity, allowing the methyl acrylate segments to bridge the matte layer through hydrogen bonds and van der Waals forces, thereby improving the interlayer peel strength between the core layer and the matte layer. Furthermore, the methyl acrylate segments of the ethylene-methyl acrylate copolymer possess a certain polarity and can form weak hydrogen bonds or van der Waals forces with the hydroxyl groups on the surface of calcium carbonate. This interfacial interaction allows the ethylene-methyl acrylate copolymer to form a uniform coating layer on the surface of calcium carbonate. The elastic segments (ethylene segments) of the ethylene-methyl acrylate copolymer preferentially yield and form microcracks during biaxial stretching. These microcracks can serve as nucleation sites for cavitation, improving the cavitation efficiency of the core layer. By adding 1-3 wt% maleic anhydride-grafted homopolymer polypropylene to the core layer, the maleic anhydride-grafted homopolymer polypropylene exhibits excellent compatibility with the homopolymer polypropylene in the core layer. The anhydride groups can physically couple (e.g., dipole-dipole interactions) with the ester groups of the ethylene-methyl acrylate copolymer and the matte layer, forming "chemical rivets" that prevent the ethylene-methyl acrylate copolymer from migrating to the matte layer. Additionally, the anhydride groups can adsorb calcium carbonate, inhibiting calcium carbonate aggregation. This invention improves interlayer bonding and refines cavity size by adding 2-4 wt% ethylene-methyl acrylate copolymer and 1-3 wt% maleic anhydride-grafted homopolymer polypropylene to the core layer.

[0019] Furthermore, the ethylene-methyl acrylate copolymer contains 75-80 wt% ethylene and 20-25 wt% methyl acrylate. If the ethylene content is too low or the methyl acrylate content is too high, it cannot effectively improve the interlayer bonding force, and the compatibility between the core layer and the matte layer is poor. If the ethylene content is too high or the methyl acrylate content is too low, it affects the cavitation effect, resulting in deviations in the optical properties of the film.

[0020] Furthermore, the grafting rate of maleic anhydride in the maleic anhydride-grafted homopolymer polypropylene is 0.5-1%. If the grafting rate of maleic anhydride in the maleic anhydride-grafted homopolymer polypropylene is too low, it may cause the ethylene-methyl acrylate copolymer to migrate into the matte layer, affecting the phase structure of the matte layer and the cavitation effect of the core layer.

[0021] Furthermore, the lower surface layer comprises homopolymer polypropylene and an anti-blocking agent. This is a conventional technique for matte label films in the art and will not be elaborated further here.

[0022] This invention also provides a method for preparing any of the above-mentioned high-temperature resistant plush-feel BOPP matte label films, comprising the following steps: weighing the raw materials of each layer according to the proportion and adding them to each extruder; after melting and plasticizing, metering by a metering pump, and extruding them into the dies of different extruders; casting them into thick sheets by a chilled roller; cutting the thick sheets into the required size (preferably 150mm*150mm*270~300μm); stretching them in a static stretching machine (preferably stretching 3*3=9 times, i.e., stretching 3 times in the transverse direction, 3 times in the longitudinal direction, and 9 times in the thickness); and preparing a film (preferably the specifications of the film are 450mm*450mm*30μm) to obtain the finished product. Detailed Implementation

[0023] The present invention will now be described more fully. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Experimental methods in the following examples or comparative examples, where specific conditions are not specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials, reagents, etc., used, unless otherwise specified, are all commercially available from the conventional market.

[0024] In the following embodiments or comparative examples:

[0025] Melt flow index is determined according to GB / T3682.1-2018 "Plastics - Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) of Thermoplastic Plastics":

[0026] The melt flow index of high-density polyethylene is 0.05 g / 10 min (test conditions: 190℃, 2.16 kg).

[0027] The isotacticity of high isotactic polypropylene is 97%, and the melt index is 8 g / 10 min (test conditions: 230℃, 2.16 kg).

[0028] The preparation method of ethylene-octene copolymer graft copolymer polypropylene is as follows: 95-100 parts of copolymer polypropylene and 25-30 parts of ethylene-octene copolymer are vacuum dried at 75-85℃ for 4 h, and then premixed with 0.05-0.15 parts of bis(tert-butylperoxyisopropyl)benzene. The mixture is fed into a twin-screw extruder with the barrel temperature in five zones set at 170 / 180 / 190 / 190 / 185℃, the screw speed at 200 rpm, and the vacuum at (0.08-0.1) MPa for 45-60 s. After water cooling and pelletizing, the mixture is dried at 75-85℃ for 4 h to obtain the ethylene-octene copolymer graft copolymer polypropylene. (Among them, the ethylene-octene copolymer graft copolymer polypropylene used in the examples was prepared according to the above method. As for the preparation method of the ethylene-octene copolymer graft copolymer polypropylene in the comparative example, those skilled in the art can adjust the content or parameters of each substance according to different grafting rates, ethylene-octene copolymers, etc., and will not be described in detail here.)

[0029] The isotacticity of the homopolymer polypropylene in the core layer and the lower surface layer is 95%, and the melt index is 8 g / 10 min (test conditions: 230℃, 2.16 kg).

[0030] The calcium carbonate pearlescent masterbatch in the core layer consists of 60 wt% calcium carbonate and 40 wt% homopolymer polypropylene, wherein the calcium carbonate particle size is 1.5 μm.

[0031] The anti-blocking masterbatch in the lower layer consists of 5 wt% silica and 95 wt% homopolymer polypropylene, wherein the silica particle size is 4.5 μm.

[0032] Example 1

[0033] This embodiment provides a high-temperature resistant, plush-feel matte masterbatch, comprising 48wt% high-density polyethylene, 24wt% high isotactic polypropylene, and 28wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 9 g / 10 min, melt index test conditions: 230℃, 2.16 kg, ethylene-octene copolymer grafting rate of 1.0%, ethylene content of 73wt%, and octene content of 27wt% in the ethylene-octene copolymer).

[0034] The preparation method of the high-temperature resistant plush-feel matte masterbatch of this embodiment includes the following steps: mixing the raw materials and adding them to a screw extruder for melt extrusion, and then drawing and granulating them underwater to obtain the high-temperature resistant plush-feel matte masterbatch.

[0035] This embodiment also provides a high-temperature resistant, plush-touch BOPP matte label film, comprising a matte layer, a core layer, and a lower surface layer arranged sequentially. The components and contents of each layer are as follows:

[0036] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch of this embodiment.

[0037] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 4wt% ethylene-methyl acrylate copolymer (ethylene content 75mol%, methyl acrylate content 25mol%) and 1wt% maleic anhydride grafted homopolymer polypropylene (maleic anhydride grafting rate 0.8%).

[0038] Bottom layer: 95 wt% homopolymer polypropylene and 5 wt% anti-blocking masterbatch.

[0039] The preparation method of the high-temperature resistant plush-feel BOPP matte label film in this embodiment includes the following steps: the raw materials of each layer are weighed according to the ratio and added to each extruder. After melting and plasticizing, they are metered by a metering pump and fed into the dies of different extruders for extrusion. The extruded materials are then cast into thick sheets by a chilled roller. The thick sheets are cut into the required size (specifically 150mm*150mm*270μm) and then stretched in a static stretching machine (preferably stretched 3*3=9 times, that is, stretched 3 times in the transverse direction, stretched 3 times in the longitudinal direction, and stretched 9 times in thickness) to prepare a film (the specifications of the film are preferably 450mm*450mm*30μm) to obtain the finished product.

[0040] In this embodiment, the total thickness of the high-temperature resistant plush-touch BOPP matte label film is 30μm, the matte layer thickness is 1.8μm, and the bottom layer thickness is 1.5μm.

[0041] Example 2

[0042] This embodiment provides a high-temperature resistant, plush-feel matte masterbatch, comprising 48wt% high-density polyethylene, 27wt% high isotactic polypropylene, and 25wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 10g / 10min, melt index test conditions: 230℃, 2.16 kg, ethylene-octene copolymer grafting rate of 0.8%, ethylene content of 75wt%, and octene content of 25wt% in the ethylene-octene copolymer).

[0043] The preparation method of the high-temperature resistant plush-feel matte masterbatch in this embodiment is the same as that of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0044] This embodiment also provides a high-temperature resistant, plush-touch BOPP matte label film, comprising a matte layer, a core layer, and a lower surface layer arranged sequentially. The components and contents of each layer are as follows:

[0045] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch of this embodiment.

[0046] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 3wt% ethylene-methyl acrylate copolymer (ethylene content 78mol%, methyl acrylate content 22mol%) and 2wt% maleic anhydride grafted homopolymer polypropylene (maleic anhydride grafting rate 1.0%).

[0047] Bottom layer: 95 wt% homopolymer polypropylene and 5 wt% anti-blocking masterbatch.

[0048] The preparation method of the high-temperature resistant plush-touch BOPP matte label film in this embodiment is the same as the preparation method of the high-temperature resistant plush-touch BOPP matte label film in Example 1.

[0049] The total thickness and the thickness of each layer of the high-temperature resistant plush-touch BOPP matte label film in this embodiment are the same as those of the high-temperature resistant plush-touch BOPP matte label film in Example 1.

[0050] Example 3

[0051] This embodiment provides a high-temperature resistant, plush-feel matte masterbatch, comprising 46wt% high-density polyethylene, 24wt% high isotactic polypropylene, and 35wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 8 g / 10 min, melt index test conditions: 230℃, 2.16 kg, ethylene-octene copolymer grafting rate of 1.2%, ethylene content of 68wt%, and octene content of 32wt% in the ethylene-octene copolymer).

[0052] The preparation method of the high-temperature resistant plush-feel matte masterbatch in this embodiment is the same as that of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0053] This embodiment also provides a high-temperature resistant, plush-touch BOPP matte label film, comprising a matte layer, a core layer, and a lower surface layer arranged sequentially. The components and contents of each layer are as follows:

[0054] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch of this embodiment.

[0055] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 2wt% ethylene-methyl acrylate copolymer (ethylene content 75mol%, methyl acrylate content 25mol%) and 3wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate 0.5%).

[0056] Bottom layer: 95 wt% homopolymer polypropylene and 5 wt% anti-blocking masterbatch.

[0057] The preparation method of the high-temperature resistant plush-touch BOPP matte label film in this embodiment is the same as the preparation method of the high-temperature resistant plush-touch BOPP matte label film in Example 1.

[0058] The total thickness and the thickness of each layer of the high-temperature resistant plush-touch BOPP matte label film in this embodiment are the same as those of the high-temperature resistant plush-touch BOPP matte label film in Example 1.

[0059] Example 4

[0060] This embodiment provides a high-temperature resistant, plush-feel matte masterbatch, comprising 43wt% high-density polyethylene, 25wt% high isotactic polypropylene, and 32wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 9 g / 10 min, melt index test conditions: 230℃, 2.16 kg, ethylene-octene copolymer grafting rate of 1.0%, ethylene content of 73wt%, and octene content of 27wt% in the ethylene-octene copolymer).

[0061] The preparation method of the high-temperature resistant plush-feel matte masterbatch in this embodiment is the same as that of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0062] This embodiment also provides a high-temperature resistant, plush-touch BOPP matte label film, comprising a matte layer, a core layer, and a lower surface layer arranged sequentially. The components and contents of each layer are as follows:

[0063] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch of this embodiment.

[0064] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 4wt% ethylene-methyl acrylate copolymer (ethylene content is 80mol%, methyl acrylate content is 20mol%) and 1wt% maleic anhydride grafted homopolymer polypropylene (maleic anhydride grafting rate is 1.0%).

[0065] Bottom layer: 95 wt% homopolymer polypropylene and 5 wt% anti-blocking masterbatch.

[0066] The preparation method of the high-temperature resistant plush-touch BOPP matte label film in this embodiment is the same as the preparation method of the high-temperature resistant plush-touch BOPP matte label film in Example 1.

[0067] The total thickness and the thickness of each layer of the high-temperature resistant plush-touch BOPP matte label film in this embodiment are the same as those of the high-temperature resistant plush-touch BOPP matte label film in Example 1.

[0068] Comparative Example 1

[0069] This comparative example provides a matte masterbatch comprising 50 wt% high-density polyethylene and 50 wt% copolymer polypropylene.

[0070] The preparation method of the matte masterbatch of this comparative example includes the following steps: mixing the raw materials and adding them to a screw extruder for melt extrusion, and then drawing and granulating them underwater to obtain the matte masterbatch.

[0071] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a lower surface layer arranged sequentially. The components and contents of each layer are as follows:

[0072] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0073] Core layer: 80wt% homopolymer polypropylene, 20wt% calcium carbonate pearlescent masterbatch.

[0074] Bottom layer: 95 wt% homopolymer polypropylene and 5 wt% anti-blocking masterbatch.

[0075] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0076] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0077] Comparative Example 2

[0078] This comparative example provides a matte masterbatch comprising 48 wt% high-density polyethylene, 32 wt% high isotactic polypropylene and 20 wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 9 g / 10 min, melt index test conditions: 230℃, 2.16 kg, grafting rate of ethylene-octene copolymer of 1.0%, ethylene content of 73 wt% and octene content of 27 wt% in ethylene-octene copolymer).

[0079] The preparation method of the matte masterbatch in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0080] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0081] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0082] Core layer: Same as the core layer in Example 1.

[0083] Bottom layer: Same as the bottom layer of Example 1.

[0084] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0085] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0086] Comparative Example 3

[0087] This comparative example provides a matte masterbatch comprising 48 wt% high-density polyethylene, 14 wt% high isotactic polypropylene and 38 wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 9 g / 10 min, melt index test conditions: 230℃, 2.16 kg, grafting rate of ethylene-octene copolymer of 1.0%, ethylene content of 73 wt% and octene content of 27 wt% in ethylene-octene copolymer).

[0088] The preparation method of the matte masterbatch in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0089] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0090] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0091] Core layer: Same as the core layer in Example 1.

[0092] Bottom layer: Same as the bottom layer of Example 1.

[0093] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0094] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0095] Comparative Example 4

[0096] This comparative example provides a matte masterbatch comprising 48 wt% high-density polyethylene, 24 wt% high isotactic polypropylene and 28 wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 10 g / 10 min, melt index test conditions: 230℃, 2.16 kg, grafting rate of ethylene-octene copolymer of 1.0%, ethylene content of 63 wt% and octene content of 37 wt% in ethylene-octene copolymer).

[0097] The preparation method of the matte masterbatch in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0098] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0099] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0100] Core layer: Same as the core layer in Example 1.

[0101] Bottom layer: Same as the bottom layer of Example 1.

[0102] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0103] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0104] Comparative Example 5

[0105] This comparative example provides a matte masterbatch comprising 48 wt% high-density polyethylene, 24 wt% high isotactic polypropylene and 28 wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 7 g / 10 min, melt index test conditions: 230℃, 2.16 kg, grafting rate of ethylene-octene copolymer of 1.0%, ethylene content of 78 wt% and octene content of 22 wt% in ethylene-octene copolymer).

[0106] The preparation method of the matte masterbatch in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0107] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0108] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0109] Core layer: Same as the core layer in Example 1.

[0110] Bottom layer: Same as the bottom layer of Example 1.

[0111] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0112] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0113] Comparative Example 6

[0114] This comparative example provides a matte masterbatch comprising 48 wt% high-density polyethylene, 24 wt% high isotactic polypropylene and 28 wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 11 g / 10 min, melt index test conditions: 230℃, 2.16 kg, grafting rate of ethylene-octene copolymer of 0.5%, ethylene content of 73 wt% and octene content of 27 wt% in ethylene-octene copolymer).

[0115] The preparation method of the matte masterbatch in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0116] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0117] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0118] Core layer: Same as the core layer in Example 1.

[0119] Bottom layer: Same as the bottom layer of Example 1.

[0120] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0121] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0122] Comparative Example 7

[0123] This comparative example provides a matte masterbatch comprising 48 wt% high-density polyethylene, 24 wt% high isotactic polypropylene and 28 wt% ethylene-octene copolymer graft copolymer polypropylene (melt index of 7 g / 10 min, melt index test conditions: 230℃, 2.16 kg, grafting rate of ethylene-octene copolymer of 1.5%, ethylene content of 73 wt% and octene content of 27 wt% in ethylene-octene copolymer).

[0124] The preparation method of the matte masterbatch in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel matte masterbatch in Example 1.

[0125] This comparative example also provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0126] Matting layer: 100wt% of the matting masterbatch of this comparative example.

[0127] Core layer: Same as the core layer in Example 1.

[0128] Bottom layer: Same as the bottom layer of Example 1.

[0129] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0130] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0131] Comparative Example 8

[0132] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0133] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0134] Core layer: 78wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 5wt% ethylene-methyl acrylate copolymer (ethylene content 75mol%, methyl acrylate content 25mol%) and 2wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate 0.8%).

[0135] Bottom layer: Same as the bottom layer of Example 1.

[0136] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0137] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0138] Comparative Example 9

[0139] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0140] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0141] Core layer: 83wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch and 2wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate of 0.8%).

[0142] Bottom layer: Same as the bottom layer of Example 1.

[0143] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0144] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0145] Comparative Example 10

[0146] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0147] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0148] Core layer: 78wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 3wt% ethylene-methyl acrylate copolymer (ethylene content 75mol%, methyl acrylate content 25mol%) and 4wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate 0.8%).

[0149] Bottom layer: Same as the bottom layer of Example 1.

[0150] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0151] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0152] Comparative Example 11

[0153] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0154] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0155] Core layer: 82wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch and 3wt% ethylene-methyl acrylate copolymer (ethylene content is 75mol% and methyl acrylate content is 25mol%).

[0156] Bottom layer: Same as the bottom layer of Example 1.

[0157] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0158] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0159] Comparative Example 12

[0160] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0161] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0162] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 3wt% ethylene-methyl acrylate copolymer (ethylene content 70mol%, methyl acrylate content 30mol%) and 2wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate 0.8%).

[0163] Bottom layer: Same as the bottom layer of Example 1.

[0164] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0165] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0166] Comparative Example 13

[0167] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0168] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0169] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 3wt% ethylene-methyl acrylate copolymer (ethylene content 85mol%, methyl acrylate content 15mol%) and 2wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate 0.8%).

[0170] Bottom layer: Same as the bottom layer of Example 1.

[0171] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0172] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0173] Comparative Example 14

[0174] This comparative example provides a BOPP matte label film, comprising a matte layer, a core layer, and a bottom layer arranged sequentially. The components and contents of each layer are as follows:

[0175] Matte layer: 100wt% of the high-temperature resistant plush-feel matte masterbatch from Example 1;

[0176] Core layer: 80wt% homopolymer polypropylene, 15wt% calcium carbonate pearlescent masterbatch, 3wt% ethylene-methyl acrylate copolymer (ethylene content 75mol%, methyl acrylate content 25mol%) and 2wt% maleic anhydride-grafted homopolymer polypropylene (maleic anhydride grafting rate 0.3%).

[0177] Bottom layer: Same as the bottom layer of Example 1.

[0178] The preparation method of the BOPP matte label film in this comparative example is the same as the preparation method of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0179] The total thickness and the thickness of each layer of the BOPP matte label film in this comparative example are the same as those of the high-temperature resistant plush-feel BOPP matte label film in Example 1.

[0180] Performance testing

[0181] The films of Examples 1-4 and Comparative Examples 1-14 were subjected to the following performance tests, and the test results are shown in Table 1:

[0182] Gloss: Tested at a 45° angle according to GB / T8807-1988 "Test Method for Specular Gloss of Plastics". Gloss A: Gloss in the width direction of the film, except for the two edges with a width of 50cm, other positions (i.e., the middle position of the film); Gloss B: Gloss in the width direction of the film, at the edge of the film with a width of 50cm.

[0183] Haze and transmittance: Tested according to GB / T2410-2008 "Determination of transmittance and haze of transparent plastics".

[0184] Matte coating feel: Touch the surface of the matte coating with your fingers and evaluate the feel.

[0185] Production smoothness: Observe whether the film production process is smooth.

[0186] Tensile strength: Tested according to GB / T 1040.3-2006 "Test of tensile properties of plastics".

[0187] SIT (Steam Initiation Temperature): Cut film samples (width 150nm~250nm) were heat-sealed at different temperatures using a heat sealer. The temperature range for this test was 120~160℃ (gradient 1℃, heat sealing time 1.0s, at least 3 parallel samples for each temperature point, averaged). The heat-sealed film samples were then cooled and stabilized at room temperature. A peel tester was used to measure the force required to separate the heat-sealed area. A 2N setting was used for the test. If the 2N peel test was passed, the temperature was considered to be the SIT (Steam Initiation Temperature).

[0188] Please refer to Table 1 for the results:

[0189] Table 1. Performance evaluation results of thin films in Examples 1-4 and Comparative Examples 1-14

[0190]

[0191] The high-temperature resistant plush-touch BOPP matte label film of Embodiments 1-4 of the present invention has a plush-touch feel, excellent matte visual effect and good matte uniformity; the matte layer and the core layer have good compatibility and good optical performance; by utilizing the high-temperature resistance of the high-temperature resistant plush-touch matte masterbatch, the film layer (or thin film) is not easy to wrinkle during heat sealing, thus synergistically protecting the matte effect.

[0192] Comparative Example 1, the BOPP matte label film, is a traditional matte label film. It does not have a velvety feel, and the matte effect of the matte layer is uneven, with poor high-temperature resistance.

[0193] In Comparative Example 2, the content of ethylene-octene copolymer graft copolymer polypropylene in the matte masterbatch used in the matte layer was relatively low. The matte layer of Comparative Example 2 had a dry feel with only a slight velvety texture, and the matte uniformity of the matte layer was poor.

[0194] In Comparative Example 3, the BOPP matte label film had a high content of ethylene-octene copolymer graft copolymer polypropylene in the matte masterbatch used for the matte layer, resulting in the formation of too many interfacial phases in the system. As a result, the tensile stress of the BOPP matte label film in Comparative Example 3 was unevenly dispersed during the production process, affecting the smoothness of production. Furthermore, the matte layer of Comparative Example 3 had a sticky feel and poor high-temperature resistance.

[0195] In Comparative Example 4, the BOPP matte label film used in the matte layer had a low ethylene content and a high octene content in the ethylene-octene copolymer graft copolymer polypropylene. As a result, the matte layer of the BOPP matte label film in Comparative Example 4 felt sticky.

[0196] In Comparative Example 5, the BOPP matte label film used in the matte layer had a higher ethylene content and a lower octene content in the ethylene-octene copolymer graft copolymer polypropylene. The matte layer of Comparative Example 5 also had a harder feel.

[0197] In Comparative Example 6, the BOPP matte label film had a low grafting rate of ethylene-octene copolymer in the ethylene-octene copolymer graft copolymer polypropylene used in the matte layer. The BOPP matte label film in Comparative Example 6 had a slight film breakage problem during the production process, and the resulting matte layer had a rough feel and an indistinct velvety feel, with only a slight velvety feel. In addition, the matte layer was uneven.

[0198] In Comparative Example 7, the BOPP matte label film has a high grafting rate of ethylene-octene copolymer in the ethylene-octene copolymer graft copolymer polypropylene used in the matte masterbatch. The matte layer has poor temperature resistance and is prone to sticking to the rollers during production, which is not conducive to smooth production. In addition, the high temperature resistance of the matte layer in Comparative Example 7 is poor.

[0199] In Comparative Example 8, the amount of ethylene-methyl acrylate copolymer added to the core layer of the BOPP matte label film was too high, resulting in a decrease in the tensile strength of the BOPP matte label film in Comparative Example 8.

[0200] In Comparative Example 9, the BOPP matte label film did not contain ethylene-methyl acrylate copolymer in the core layer, resulting in a deviation in the optical performance of the BOPP matte label film.

[0201] In Comparative Example 10, the amount of maleic anhydride-grafted homopolymer polypropylene added to the core layer was too high. During the biaxial stretching process of the production process, the BOPP matte label film of Comparative Example 10 was prone to stress concentration, resulting in slight film breakage and affecting the smoothness of production.

[0202] In Comparative Example 11, the BOPP matte label film did not contain maleic anhydride-grafted homopolymer polypropylene in the core layer, which is not conducive to improving the compatibility of ethylene-methyl acrylate copolymer in the core layer. The ethylene-methyl acrylate copolymer is easy to migrate to the matte layer, affecting the matte effect of the matte layer, and the film has poor optical properties.

[0203] In Comparative Example 12, the BOPP matte label film had a low ethylene content and a high methyl acrylate content in the ethylene-methyl acrylate copolymer in the core layer, resulting in poor compatibility between the core layer and the matte layer, which affected the optical properties of the film.

[0204] In Comparative Example 13, the BOPP matte label film had a higher ethylene content and a lower methyl acrylate content in the ethylene-methyl acrylate copolymer in the core layer, resulting in poor optical performance of the BOPP matte label film.

[0205] In Comparative Example 14, the maleic anhydride grafting rate in the maleic anhydride-grafted homopolymer polypropylene in the core layer was low, which caused some of the ethylene-methyl acrylate copolymer to migrate into the matte layer, affecting the phase structure of the matte layer and causing the optical performance of the BOPP matte label film in Comparative Example 14 to deviate.

[0206] The above-described embodiments are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A high temperature resistant, plush touch, matte BOPP label film characterized in that: The extinction layer, the core layer and the lower surface layer are sequentially arranged; the extinction layer comprises a high-temperature-resistant plush touch extinction masterbatch, the high-temperature-resistant plush touch extinction masterbatch comprises 42-48 wt% high-density polyethylene, 24-28 wt% high isotactic polypropylene and 25-35 wt% ethylene-octene copolymer grafted copolymer polypropylene; the isotacticity of the high isotactic polypropylene is 95-97%; the grafting rate of the ethylene-octene copolymer in the ethylene-octene copolymer grafted copolymer polypropylene is 0.8-1.2%; the content of ethylene in the ethylene-octene copolymer is 65-75 wt%, and the content of octene is 25-35 wt%; the core layer comprises homopolymer polypropylene, 15-20 wt% calcium carbonate pearl masterbatch, 2-4 wt% ethylene-methyl acrylate copolymer and 1-3 wt% maleic anhydride grafted homopolymer polypropylene; the content of ethylene in the ethylene-methyl acrylate copolymer is 75-80 wt%, and the content of methyl acrylate is 20-25 wt%; the grafting rate of maleic anhydride in the maleic anhydride grafted homopolymer polypropylene is 0.5-1%.

2. The high temperature resistant, plush touch, BOPP matt label film according to claim 1, characterized in that: The melt index of the ethylene-octene copolymer grafted copolymer polypropylene is 8-10 g / 10 min.

3. The high temperature resistant, plush touch, BOPP matt label film according to claim 1, characterized in that: The preparation method of the ethylene-octene copolymer grafted copolymer polypropylene is as follows: 95-100 parts of copolymer polypropylene and 25-30 parts of ethylene-octene copolymer are vacuum dried at 75-85℃ for 4 h, then pre-mixed with 0.05-0.15 parts of bis(tert-butyl peroxyisopropyl) benzene, fed into a twin-screw extruder, the barrel five-zone temperature is 170 / 180 / 190 / 190 / 185℃, the screw rotation speed is 200 rpm, the vacuum is (0.08-0.1) MPa, the residence time is 45-60 s, after water cooling and granulation, and then dried at 75-85℃ for 4 h, the ethylene-octene copolymer grafted copolymer polypropylene is obtained.

4. The high temperature resistant, plush touch, BOPP matt label film according to claim 1, characterized in that: The melt index of the high-density polyethylene is 0.05-0.1 g / 10 min, and the melt index of the high isotactic polypropylene is 7-8 g / 10 min.

5. The high temperature resistant, plush touch, BOPP matt label film according to claim 1, characterized in that: The preparation method of the high-temperature-resistant plush touch extinction masterbatch comprises the following steps: after mixing the raw materials, melt extruding in a screw machine, and then underwater wire drawing and granulation to obtain the high-temperature-resistant plush touch extinction masterbatch.

6. The high temperature resistant, plush touch, BOPP matt label film according to claim 1, characterized in that: The content of ethylene in the ethylene-methyl acrylate copolymer is 75-80 wt%, and the content of methyl acrylate is 20-25 wt%.

7. The high temperature resistant, plush touch, BOPP matt label film according to claim 1, characterized in that: The lower surface layer comprises homopolymer polypropylene and an anti-blocking agent.

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